XFA: Upgrade libpng to 1.6.20.
R=tsepez@chromium.org
Review URL: https://codereview.chromium.org/1591483003 .
diff --git a/core/src/fxcodec/codec/DEPS b/core/src/fxcodec/codec/DEPS
new file mode 100644
index 0000000..9caa4d8
--- /dev/null
+++ b/core/src/fxcodec/codec/DEPS
@@ -0,0 +1,3 @@
+include_rules = [
+ '+third_party/libpng/png.h',
+]
diff --git a/core/src/fxcodec/codec/fx_codec_png.cpp b/core/src/fxcodec/codec/fx_codec_png.cpp
index 3acfc19..97c2f77 100644
--- a/core/src/fxcodec/codec/fx_codec_png.cpp
+++ b/core/src/fxcodec/codec/fx_codec_png.cpp
@@ -12,7 +12,7 @@
extern "C" {
#undef FAR
-#include "third_party/lpng_v163/png.h"
+#include "third_party/libpng/png.h"
}
static void _png_error_data(png_structp png_ptr, png_const_charp error_msg) {
diff --git a/samples/DEPS b/samples/DEPS
index 7bd794e..18ab975 100644
--- a/samples/DEPS
+++ b/samples/DEPS
@@ -1,6 +1,6 @@
include_rules = [
- '+fx_lpng',
'+public',
+ '+third_party/libpng',
'+third_party/zlib_v128',
'+v8',
]
diff --git a/samples/image_diff_png.cc b/samples/image_diff_png.cc
index 6ad7f88..01df836 100644
--- a/samples/image_diff_png.cc
+++ b/samples/image_diff_png.cc
@@ -17,7 +17,7 @@
#include <string>
#include "third_party/base/logging.h"
-#include "third_party/lpng_v163/png.h"
+#include "third_party/libpng/png.h"
#include "third_party/zlib_v128/zlib.h"
namespace image_diff_png {
diff --git a/third_party/BUILD.gn b/third_party/BUILD.gn
index 5f35432..d8d1dd2 100644
--- a/third_party/BUILD.gn
+++ b/third_party/BUILD.gn
@@ -278,22 +278,28 @@
"//third_party/pdfium:pdfium_config",
]
sources = [
- "lpng_v163/png.h",
- "lpng_v163/png.c",
- "lpng_v163/pngerror.c",
- "lpng_v163/pngget.c",
- "lpng_v163/pngmem.c",
- "lpng_v163/pngpread.c",
- "lpng_v163/pngread.c",
- "lpng_v163/pngrio.c",
- "lpng_v163/pngrtran.c",
- "lpng_v163/pngrutil.c",
- "lpng_v163/pngset.c",
- "lpng_v163/pngtrans.c",
- "lpng_v163/pngwio.c",
- "lpng_v163/pngwrite.c",
- "lpng_v163/pngwtran.c",
- "lpng_v163/pngwutil.c",
+ "libpng/png.c",
+ "libpng/png.h",
+ "libpng/pngconf.h",
+ "libpng/pngdebug.h",
+ "libpng/pngerror.c",
+ "libpng/pngget.c",
+ "libpng/pnginfo.h",
+ "libpng/pnglibconf.h",
+ "libpng/pngmem.c",
+ "libpng/pngpread.c",
+ "libpng/pngpriv.h",
+ "libpng/pngread.c",
+ "libpng/pngrio.c",
+ "libpng/pngrtran.c",
+ "libpng/pngrutil.c",
+ "libpng/pngset.c",
+ "libpng/pngstruct.h",
+ "libpng/pngtrans.c",
+ "libpng/pngwio.c",
+ "libpng/pngwrite.c",
+ "libpng/pngwtran.c",
+ "libpng/pngwutil.c",
]
}
diff --git a/third_party/libpng/0000-build-config.patch b/third_party/libpng/0000-build-config.patch
new file mode 100644
index 0000000..4f00139
--- /dev/null
+++ b/third_party/libpng/0000-build-config.patch
@@ -0,0 +1,43 @@
+diff a/third_party/libpng/pngmem.c b/third_party/libpng/pngmem.c
+--- a/third_party/libpng/pngmem.c
++++ b/third_party/libpng/pngmem.c
+@@ -19,6 +19,9 @@
+
+ #include "pngpriv.h"
+
++void* FXMEM_DefaultAlloc(int byte_size, int);
++void FXMEM_DefaultFree(void* pointer, int);
++
+ #if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
+ /* Free a png_struct */
+ void /* PRIVATE */
+@@ -92,7 +95,7 @@
+
+ else
+ #endif
+- return malloc((size_t)size); /* checked for truncation above */
++ return FXMEM_DefaultAlloc((int)size, 0);
+ }
+
+ else
+@@ -249,7 +252,7 @@
+ return;
+ #endif /* USER_MEM */
+
+- free(ptr);
++ FXMEM_DefaultFree(ptr, 0);
+ }
+
+ #ifdef PNG_USER_MEM_SUPPORTED
+diff a/third_party/libpng/pngstruct.h b/third_party/libpng/pngstruct.h
+--- a/third_party/libpng/pngstruct.h
++++ b/third_party/libpng/pngstruct.h
+@@ -27,7 +27,7 @@
+ /* We must ensure that zlib uses 'const' in declarations. */
+ # define ZLIB_CONST
+ #endif
+-#include "zlib.h"
++#include "third_party/zlib_v128/zlib.h"
+ #ifdef const
+ /* zlib.h sometimes #defines const to nothing, undo this. */
+ # undef const
diff --git a/third_party/libpng/0001-disable-arm-neon.patch b/third_party/libpng/0001-disable-arm-neon.patch
new file mode 100644
index 0000000..b5105f7
--- /dev/null
+++ b/third_party/libpng/0001-disable-arm-neon.patch
@@ -0,0 +1,12 @@
+diff a/third_party/libpng/pngpriv.h b/third_party/libpng/pngpriv.h
+--- a/third_party/libpng/pngpriv.h
++++ b/third_party/libpng/pngpriv.h
+@@ -127,7 +127,7 @@
+ */
+ # if (defined(__ARM_NEON__) || defined(__ARM_NEON)) && \
+ defined(PNG_ALIGNED_MEMORY_SUPPORTED)
+-# define PNG_ARM_NEON_OPT 2
++# define PNG_ARM_NEON_OPT 0
+ # else
+ # define PNG_ARM_NEON_OPT 0
+ # endif
diff --git a/third_party/libpng/README.pdfium b/third_party/libpng/README.pdfium
new file mode 100644
index 0000000..66d2d06
--- /dev/null
+++ b/third_party/libpng/README.pdfium
@@ -0,0 +1,14 @@
+Name: libpng
+URL: http://www.libpng.org/pub/png/libpng.html
+Version: 1.6.20
+Security Critical: yes
+License: libpng license
+
+Description:
+PNG library.
+
+Local Modifications:
+
+pnglibconf.h: a copy of libpng's scripts/pnglibconf.h.prebuilt.
+0000-build-config.patch: Local build configuration changes.
+0001-disable-arm-neon.diff: Disable ARM NEON optimizations.
diff --git a/third_party/lpng_v163/png.c b/third_party/libpng/png.c
similarity index 85%
rename from third_party/lpng_v163/png.c
rename to third_party/libpng/png.c
index 93c675b..c183e3f 100644
--- a/third_party/lpng_v163/png.c
+++ b/third_party/libpng/png.c
@@ -1,4297 +1,4498 @@
-/* png.c - location for general purpose libpng functions
- *
- * Last changed in libpng 1.6.2 [April 25, 2013]
- * Copyright (c) 1998-2013 Glenn Randers-Pehrson
- * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
- * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
- *
- * This code is released under the libpng license.
- * For conditions of distribution and use, see the disclaimer
- * and license in png.h
- */
-
-#include "pngpriv.h"
-
-/* Generate a compiler error if there is an old png.h in the search path. */
-typedef png_libpng_version_1_6_3 Your_png_h_is_not_version_1_6_3;
-
-/* Tells libpng that we have already handled the first "num_bytes" bytes
- * of the PNG file signature. If the PNG data is embedded into another
- * stream we can set num_bytes = 8 so that libpng will not attempt to read
- * or write any of the magic bytes before it starts on the IHDR.
- */
-
-#ifdef PNG_READ_SUPPORTED
-void PNGAPI
-png_set_sig_bytes(png_structrp png_ptr, int num_bytes)
-{
- png_debug(1, "in png_set_sig_bytes");
-
- if (png_ptr == NULL)
- return;
-
- if (num_bytes > 8)
- png_error(png_ptr, "Too many bytes for PNG signature");
-
- png_ptr->sig_bytes = (png_byte)(num_bytes < 0 ? 0 : num_bytes);
-}
-
-/* Checks whether the supplied bytes match the PNG signature. We allow
- * checking less than the full 8-byte signature so that those apps that
- * already read the first few bytes of a file to determine the file type
- * can simply check the remaining bytes for extra assurance. Returns
- * an integer less than, equal to, or greater than zero if sig is found,
- * respectively, to be less than, to match, or be greater than the correct
- * PNG signature (this is the same behavior as strcmp, memcmp, etc).
- */
-int PNGAPI
-png_sig_cmp(png_const_bytep sig, png_size_t start, png_size_t num_to_check)
-{
- png_byte png_signature[8] = {137, 80, 78, 71, 13, 10, 26, 10};
-
- if (num_to_check > 8)
- num_to_check = 8;
-
- else if (num_to_check < 1)
- return (-1);
-
- if (start > 7)
- return (-1);
-
- if (start + num_to_check > 8)
- num_to_check = 8 - start;
-
- return ((int)(memcmp(&sig[start], &png_signature[start], num_to_check)));
-}
-
-#endif /* PNG_READ_SUPPORTED */
-
-#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
-/* Function to allocate memory for zlib */
-PNG_FUNCTION(voidpf /* PRIVATE */,
-png_zalloc,(voidpf png_ptr, uInt items, uInt size),PNG_ALLOCATED)
-{
- png_alloc_size_t num_bytes = size;
-
- if (png_ptr == NULL)
- return NULL;
-
- if (items >= (~(png_alloc_size_t)0)/size)
- {
- png_warning (png_voidcast(png_structrp, png_ptr),
- "Potential overflow in png_zalloc()");
- return NULL;
- }
-
- num_bytes *= items;
- return png_malloc_warn(png_voidcast(png_structrp, png_ptr), num_bytes);
-}
-
-/* Function to free memory for zlib */
-void /* PRIVATE */
-png_zfree(voidpf png_ptr, voidpf ptr)
-{
- png_free(png_voidcast(png_const_structrp,png_ptr), ptr);
-}
-
-/* Reset the CRC variable to 32 bits of 1's. Care must be taken
- * in case CRC is > 32 bits to leave the top bits 0.
- */
-void /* PRIVATE */
-png_reset_crc(png_structrp png_ptr)
-{
- /* The cast is safe because the crc is a 32 bit value. */
- png_ptr->crc = (png_uint_32)crc32(0, Z_NULL, 0);
-}
-
-/* Calculate the CRC over a section of data. We can only pass as
- * much data to this routine as the largest single buffer size. We
- * also check that this data will actually be used before going to the
- * trouble of calculating it.
- */
-void /* PRIVATE */
-png_calculate_crc(png_structrp png_ptr, png_const_bytep ptr, png_size_t length)
-{
- int need_crc = 1;
-
- if (PNG_CHUNK_ANCILLARY(png_ptr->chunk_name))
- {
- if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_MASK) ==
- (PNG_FLAG_CRC_ANCILLARY_USE | PNG_FLAG_CRC_ANCILLARY_NOWARN))
- need_crc = 0;
- }
-
- else /* critical */
- {
- if (png_ptr->flags & PNG_FLAG_CRC_CRITICAL_IGNORE)
- need_crc = 0;
- }
-
- /* 'uLong' is defined in zlib.h as unsigned long; this means that on some
- * systems it is a 64 bit value. crc32, however, returns 32 bits so the
- * following cast is safe. 'uInt' may be no more than 16 bits, so it is
- * necessary to perform a loop here.
- */
- if (need_crc && length > 0)
- {
- uLong crc = png_ptr->crc; /* Should never issue a warning */
-
- do
- {
- uInt safe_length = (uInt)length;
- if (safe_length == 0)
- safe_length = (uInt)-1; /* evil, but safe */
-
- crc = crc32(crc, ptr, safe_length);
-
- /* The following should never issue compiler warnings; if they do the
- * target system has characteristics that will probably violate other
- * assumptions within the libpng code.
- */
- ptr += safe_length;
- length -= safe_length;
- }
- while (length > 0);
-
- /* And the following is always safe because the crc is only 32 bits. */
- png_ptr->crc = (png_uint_32)crc;
- }
-}
-
-/* Check a user supplied version number, called from both read and write
- * functions that create a png_struct.
- */
-int
-png_user_version_check(png_structrp png_ptr, png_const_charp user_png_ver)
-{
- if (user_png_ver)
- {
- int i = 0;
-
- do
- {
- if (user_png_ver[i] != png_libpng_ver[i])
- png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
- } while (png_libpng_ver[i++]);
- }
-
- else
- png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
-
- if (png_ptr->flags & PNG_FLAG_LIBRARY_MISMATCH)
- {
- /* Libpng 0.90 and later are binary incompatible with libpng 0.89, so
- * we must recompile any applications that use any older library version.
- * For versions after libpng 1.0, we will be compatible, so we need
- * only check the first and third digits (note that when we reach version
- * 1.10 we will need to check the fourth symbol, namely user_png_ver[3]).
- */
- if (user_png_ver == NULL || user_png_ver[0] != png_libpng_ver[0] ||
- (user_png_ver[0] == '1' && (user_png_ver[2] != png_libpng_ver[2] ||
- user_png_ver[3] != png_libpng_ver[3])) ||
- (user_png_ver[0] == '0' && user_png_ver[2] < '9'))
- {
-#ifdef PNG_WARNINGS_SUPPORTED
- size_t pos = 0;
- char m[128];
-
- pos = png_safecat(m, (sizeof m), pos,
- "Application built with libpng-");
- pos = png_safecat(m, (sizeof m), pos, user_png_ver);
- pos = png_safecat(m, (sizeof m), pos, " but running with ");
- pos = png_safecat(m, (sizeof m), pos, png_libpng_ver);
-
- png_warning(png_ptr, m);
-#endif
-
-#ifdef PNG_ERROR_NUMBERS_SUPPORTED
- png_ptr->flags = 0;
-#endif
-
- return 0;
- }
- }
-
- /* Success return. */
- return 1;
-}
-
-/* Generic function to create a png_struct for either read or write - this
- * contains the common initialization.
- */
-PNG_FUNCTION(png_structp /* PRIVATE */,
-png_create_png_struct,(png_const_charp user_png_ver, png_voidp error_ptr,
- png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
- png_malloc_ptr malloc_fn, png_free_ptr free_fn),PNG_ALLOCATED)
-{
- png_struct create_struct;
-# ifdef PNG_SETJMP_SUPPORTED
- jmp_buf create_jmp_buf;
-# endif
-
- /* This temporary stack-allocated structure is used to provide a place to
- * build enough context to allow the user provided memory allocator (if any)
- * to be called.
- */
- memset(&create_struct, 0, (sizeof create_struct));
-
- /* Added at libpng-1.2.6 */
-# ifdef PNG_USER_LIMITS_SUPPORTED
- create_struct.user_width_max = PNG_USER_WIDTH_MAX;
- create_struct.user_height_max = PNG_USER_HEIGHT_MAX;
-
-# ifdef PNG_USER_CHUNK_CACHE_MAX
- /* Added at libpng-1.2.43 and 1.4.0 */
- create_struct.user_chunk_cache_max = PNG_USER_CHUNK_CACHE_MAX;
-# endif
-
-# ifdef PNG_USER_CHUNK_MALLOC_MAX
- /* Added at libpng-1.2.43 and 1.4.1, required only for read but exists
- * in png_struct regardless.
- */
- create_struct.user_chunk_malloc_max = PNG_USER_CHUNK_MALLOC_MAX;
-# endif
-# endif
-
- /* The following two API calls simply set fields in png_struct, so it is safe
- * to do them now even though error handling is not yet set up.
- */
-# ifdef PNG_USER_MEM_SUPPORTED
- png_set_mem_fn(&create_struct, mem_ptr, malloc_fn, free_fn);
-# endif
-
- /* (*error_fn) can return control to the caller after the error_ptr is set,
- * this will result in a memory leak unless the error_fn does something
- * extremely sophisticated. The design lacks merit but is implicit in the
- * API.
- */
- png_set_error_fn(&create_struct, error_ptr, error_fn, warn_fn);
-
-# ifdef PNG_SETJMP_SUPPORTED
- if (!setjmp(create_jmp_buf))
- {
- /* Temporarily fake out the longjmp information until we have
- * successfully completed this function. This only works if we have
- * setjmp() support compiled in, but it is safe - this stuff should
- * never happen.
- */
- create_struct.jmp_buf_ptr = &create_jmp_buf;
- create_struct.jmp_buf_size = 0; /*stack allocation*/
- create_struct.longjmp_fn = longjmp;
-# else
- {
-# endif
- /* Call the general version checker (shared with read and write code):
- */
- if (png_user_version_check(&create_struct, user_png_ver))
- {
- png_structrp png_ptr = png_voidcast(png_structrp,
- png_malloc_warn(&create_struct, (sizeof *png_ptr)));
-
- if (png_ptr != NULL)
- {
- /* png_ptr->zstream holds a back-pointer to the png_struct, so
- * this can only be done now:
- */
- create_struct.zstream.zalloc = png_zalloc;
- create_struct.zstream.zfree = png_zfree;
- create_struct.zstream.opaque = png_ptr;
-
-# ifdef PNG_SETJMP_SUPPORTED
- /* Eliminate the local error handling: */
- create_struct.jmp_buf_ptr = NULL;
- create_struct.jmp_buf_size = 0;
- create_struct.longjmp_fn = 0;
-# endif
-
- *png_ptr = create_struct;
-
- /* This is the successful return point */
- return png_ptr;
- }
- }
- }
-
- /* A longjmp because of a bug in the application storage allocator or a
- * simple failure to allocate the png_struct.
- */
- return NULL;
-}
-
-/* Allocate the memory for an info_struct for the application. */
-PNG_FUNCTION(png_infop,PNGAPI
-png_create_info_struct,(png_const_structrp png_ptr),PNG_ALLOCATED)
-{
- png_inforp info_ptr;
-
- png_debug(1, "in png_create_info_struct");
-
- if (png_ptr == NULL)
- return NULL;
-
- /* Use the internal API that does not (or at least should not) error out, so
- * that this call always returns ok. The application typically sets up the
- * error handling *after* creating the info_struct because this is the way it
- * has always been done in 'example.c'.
- */
- info_ptr = png_voidcast(png_inforp, png_malloc_base(png_ptr,
- (sizeof *info_ptr)));
-
- if (info_ptr != NULL)
- memset(info_ptr, 0, (sizeof *info_ptr));
-
- return info_ptr;
-}
-
-/* This function frees the memory associated with a single info struct.
- * Normally, one would use either png_destroy_read_struct() or
- * png_destroy_write_struct() to free an info struct, but this may be
- * useful for some applications. From libpng 1.6.0 this function is also used
- * internally to implement the png_info release part of the 'struct' destroy
- * APIs. This ensures that all possible approaches free the same data (all of
- * it).
- */
-void PNGAPI
-png_destroy_info_struct(png_const_structrp png_ptr, png_infopp info_ptr_ptr)
-{
- png_inforp info_ptr = NULL;
-
- png_debug(1, "in png_destroy_info_struct");
-
- if (png_ptr == NULL)
- return;
-
- if (info_ptr_ptr != NULL)
- info_ptr = *info_ptr_ptr;
-
- if (info_ptr != NULL)
- {
- /* Do this first in case of an error below; if the app implements its own
- * memory management this can lead to png_free calling png_error, which
- * will abort this routine and return control to the app error handler.
- * An infinite loop may result if it then tries to free the same info
- * ptr.
- */
- *info_ptr_ptr = NULL;
-
- png_free_data(png_ptr, info_ptr, PNG_FREE_ALL, -1);
- memset(info_ptr, 0, (sizeof *info_ptr));
- png_free(png_ptr, info_ptr);
- }
-}
-
-/* Initialize the info structure. This is now an internal function (0.89)
- * and applications using it are urged to use png_create_info_struct()
- * instead. Use deprecated in 1.6.0, internal use removed (used internally it
- * is just a memset).
- *
- * NOTE: it is almost inconceivable that this API is used because it bypasses
- * the user-memory mechanism and the user error handling/warning mechanisms in
- * those cases where it does anything other than a memset.
- */
-PNG_FUNCTION(void,PNGAPI
-png_info_init_3,(png_infopp ptr_ptr, png_size_t png_info_struct_size),
- PNG_DEPRECATED)
-{
- png_inforp info_ptr = *ptr_ptr;
-
- png_debug(1, "in png_info_init_3");
-
- if (info_ptr == NULL)
- return;
-
- if ((sizeof (png_info)) > png_info_struct_size)
- {
- *ptr_ptr = NULL;
- /* The following line is why this API should not be used: */
- free(info_ptr);
- info_ptr = png_voidcast(png_inforp, png_malloc_base(NULL,
- (sizeof *info_ptr)));
- *ptr_ptr = info_ptr;
- }
-
- /* Set everything to 0 */
- memset(info_ptr, 0, (sizeof *info_ptr));
-}
-
-/* The following API is not called internally */
-void PNGAPI
-png_data_freer(png_const_structrp png_ptr, png_inforp info_ptr,
- int freer, png_uint_32 mask)
-{
- png_debug(1, "in png_data_freer");
-
- if (png_ptr == NULL || info_ptr == NULL)
- return;
-
- if (freer == PNG_DESTROY_WILL_FREE_DATA)
- info_ptr->free_me |= mask;
-
- else if (freer == PNG_USER_WILL_FREE_DATA)
- info_ptr->free_me &= ~mask;
-
- else
- png_error(png_ptr, "Unknown freer parameter in png_data_freer");
-}
-
-void PNGAPI
-png_free_data(png_const_structrp png_ptr, png_inforp info_ptr, png_uint_32 mask,
- int num)
-{
- png_debug(1, "in png_free_data");
-
- if (png_ptr == NULL || info_ptr == NULL)
- return;
-
-#ifdef PNG_TEXT_SUPPORTED
- /* Free text item num or (if num == -1) all text items */
- if ((mask & PNG_FREE_TEXT) & info_ptr->free_me)
- {
- if (num != -1)
- {
- if (info_ptr->text && info_ptr->text[num].key)
- {
- png_free(png_ptr, info_ptr->text[num].key);
- info_ptr->text[num].key = NULL;
- }
- }
-
- else
- {
- int i;
- for (i = 0; i < info_ptr->num_text; i++)
- png_free_data(png_ptr, info_ptr, PNG_FREE_TEXT, i);
- png_free(png_ptr, info_ptr->text);
- info_ptr->text = NULL;
- info_ptr->num_text=0;
- }
- }
-#endif
-
-#ifdef PNG_tRNS_SUPPORTED
- /* Free any tRNS entry */
- if ((mask & PNG_FREE_TRNS) & info_ptr->free_me)
- {
- png_free(png_ptr, info_ptr->trans_alpha);
- info_ptr->trans_alpha = NULL;
- info_ptr->valid &= ~PNG_INFO_tRNS;
- }
-#endif
-
-#ifdef PNG_sCAL_SUPPORTED
- /* Free any sCAL entry */
- if ((mask & PNG_FREE_SCAL) & info_ptr->free_me)
- {
- png_free(png_ptr, info_ptr->scal_s_width);
- png_free(png_ptr, info_ptr->scal_s_height);
- info_ptr->scal_s_width = NULL;
- info_ptr->scal_s_height = NULL;
- info_ptr->valid &= ~PNG_INFO_sCAL;
- }
-#endif
-
-#ifdef PNG_pCAL_SUPPORTED
- /* Free any pCAL entry */
- if ((mask & PNG_FREE_PCAL) & info_ptr->free_me)
- {
- png_free(png_ptr, info_ptr->pcal_purpose);
- png_free(png_ptr, info_ptr->pcal_units);
- info_ptr->pcal_purpose = NULL;
- info_ptr->pcal_units = NULL;
- if (info_ptr->pcal_params != NULL)
- {
- unsigned int i;
- for (i = 0; i < info_ptr->pcal_nparams; i++)
- {
- png_free(png_ptr, info_ptr->pcal_params[i]);
- info_ptr->pcal_params[i] = NULL;
- }
- png_free(png_ptr, info_ptr->pcal_params);
- info_ptr->pcal_params = NULL;
- }
- info_ptr->valid &= ~PNG_INFO_pCAL;
- }
-#endif
-
-#ifdef PNG_iCCP_SUPPORTED
- /* Free any profile entry */
- if ((mask & PNG_FREE_ICCP) & info_ptr->free_me)
- {
- png_free(png_ptr, info_ptr->iccp_name);
- png_free(png_ptr, info_ptr->iccp_profile);
- info_ptr->iccp_name = NULL;
- info_ptr->iccp_profile = NULL;
- info_ptr->valid &= ~PNG_INFO_iCCP;
- }
-#endif
-
-#ifdef PNG_sPLT_SUPPORTED
- /* Free a given sPLT entry, or (if num == -1) all sPLT entries */
- if ((mask & PNG_FREE_SPLT) & info_ptr->free_me)
- {
- if (num != -1)
- {
- if (info_ptr->splt_palettes)
- {
- png_free(png_ptr, info_ptr->splt_palettes[num].name);
- png_free(png_ptr, info_ptr->splt_palettes[num].entries);
- info_ptr->splt_palettes[num].name = NULL;
- info_ptr->splt_palettes[num].entries = NULL;
- }
- }
-
- else
- {
- if (info_ptr->splt_palettes_num)
- {
- int i;
- for (i = 0; i < info_ptr->splt_palettes_num; i++)
- png_free_data(png_ptr, info_ptr, PNG_FREE_SPLT, (int)i);
-
- png_free(png_ptr, info_ptr->splt_palettes);
- info_ptr->splt_palettes = NULL;
- info_ptr->splt_palettes_num = 0;
- }
- info_ptr->valid &= ~PNG_INFO_sPLT;
- }
- }
-#endif
-
-#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
- if ((mask & PNG_FREE_UNKN) & info_ptr->free_me)
- {
- if (num != -1)
- {
- if (info_ptr->unknown_chunks)
- {
- png_free(png_ptr, info_ptr->unknown_chunks[num].data);
- info_ptr->unknown_chunks[num].data = NULL;
- }
- }
-
- else
- {
- int i;
-
- if (info_ptr->unknown_chunks_num)
- {
- for (i = 0; i < info_ptr->unknown_chunks_num; i++)
- png_free_data(png_ptr, info_ptr, PNG_FREE_UNKN, (int)i);
-
- png_free(png_ptr, info_ptr->unknown_chunks);
- info_ptr->unknown_chunks = NULL;
- info_ptr->unknown_chunks_num = 0;
- }
- }
- }
-#endif
-
-#ifdef PNG_hIST_SUPPORTED
- /* Free any hIST entry */
- if ((mask & PNG_FREE_HIST) & info_ptr->free_me)
- {
- png_free(png_ptr, info_ptr->hist);
- info_ptr->hist = NULL;
- info_ptr->valid &= ~PNG_INFO_hIST;
- }
-#endif
-
- /* Free any PLTE entry that was internally allocated */
- if ((mask & PNG_FREE_PLTE) & info_ptr->free_me)
- {
- png_free(png_ptr, info_ptr->palette);
- info_ptr->palette = NULL;
- info_ptr->valid &= ~PNG_INFO_PLTE;
- info_ptr->num_palette = 0;
- }
-
-#ifdef PNG_INFO_IMAGE_SUPPORTED
- /* Free any image bits attached to the info structure */
- if ((mask & PNG_FREE_ROWS) & info_ptr->free_me)
- {
- if (info_ptr->row_pointers)
- {
- png_uint_32 row;
- for (row = 0; row < info_ptr->height; row++)
- {
- png_free(png_ptr, info_ptr->row_pointers[row]);
- info_ptr->row_pointers[row] = NULL;
- }
- png_free(png_ptr, info_ptr->row_pointers);
- info_ptr->row_pointers = NULL;
- }
- info_ptr->valid &= ~PNG_INFO_IDAT;
- }
-#endif
-
- if (num != -1)
- mask &= ~PNG_FREE_MUL;
-
- info_ptr->free_me &= ~mask;
-}
-#endif /* defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) */
-
-/* This function returns a pointer to the io_ptr associated with the user
- * functions. The application should free any memory associated with this
- * pointer before png_write_destroy() or png_read_destroy() are called.
- */
-png_voidp PNGAPI
-png_get_io_ptr(png_const_structrp png_ptr)
-{
- if (png_ptr == NULL)
- return (NULL);
-
- return (png_ptr->io_ptr);
-}
-
-#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
-# ifdef PNG_STDIO_SUPPORTED
-/* Initialize the default input/output functions for the PNG file. If you
- * use your own read or write routines, you can call either png_set_read_fn()
- * or png_set_write_fn() instead of png_init_io(). If you have defined
- * PNG_NO_STDIO or otherwise disabled PNG_STDIO_SUPPORTED, you must use a
- * function of your own because "FILE *" isn't necessarily available.
- */
-void PNGAPI
-png_init_io(png_structrp png_ptr, png_FILE_p fp)
-{
- png_debug(1, "in png_init_io");
-
- if (png_ptr == NULL)
- return;
-
- png_ptr->io_ptr = (png_voidp)fp;
-}
-# endif
-
-#ifdef PNG_SAVE_INT_32_SUPPORTED
-/* The png_save_int_32 function assumes integers are stored in two's
- * complement format. If this isn't the case, then this routine needs to
- * be modified to write data in two's complement format. Note that,
- * the following works correctly even if png_int_32 has more than 32 bits
- * (compare the more complex code required on read for sign extension.)
- */
-void PNGAPI
-png_save_int_32(png_bytep buf, png_int_32 i)
-{
- buf[0] = (png_byte)((i >> 24) & 0xff);
- buf[1] = (png_byte)((i >> 16) & 0xff);
- buf[2] = (png_byte)((i >> 8) & 0xff);
- buf[3] = (png_byte)(i & 0xff);
-}
-#endif
-
-# ifdef PNG_TIME_RFC1123_SUPPORTED
-/* Convert the supplied time into an RFC 1123 string suitable for use in
- * a "Creation Time" or other text-based time string.
- */
-int PNGAPI
-png_convert_to_rfc1123_buffer(char out[29], png_const_timep ptime)
-{
- static PNG_CONST char short_months[12][4] =
- {"Jan", "Feb", "Mar", "Apr", "May", "Jun",
- "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"};
-
- if (out == NULL)
- return 0;
-
- if (ptime->year > 9999 /* RFC1123 limitation */ ||
- ptime->month == 0 || ptime->month > 12 ||
- ptime->day == 0 || ptime->day > 31 ||
- ptime->hour > 23 || ptime->minute > 59 ||
- ptime->second > 60)
- return 0;
-
- {
- size_t pos = 0;
- char number_buf[5]; /* enough for a four-digit year */
-
-# define APPEND_STRING(string) pos = png_safecat(out, 29, pos, (string))
-# define APPEND_NUMBER(format, value)\
- APPEND_STRING(PNG_FORMAT_NUMBER(number_buf, format, (value)))
-# define APPEND(ch) if (pos < 28) out[pos++] = (ch)
-
- APPEND_NUMBER(PNG_NUMBER_FORMAT_u, (unsigned)ptime->day);
- APPEND(' ');
- APPEND_STRING(short_months[(ptime->month - 1)]);
- APPEND(' ');
- APPEND_NUMBER(PNG_NUMBER_FORMAT_u, ptime->year);
- APPEND(' ');
- APPEND_NUMBER(PNG_NUMBER_FORMAT_02u, (unsigned)ptime->hour);
- APPEND(':');
- APPEND_NUMBER(PNG_NUMBER_FORMAT_02u, (unsigned)ptime->minute);
- APPEND(':');
- APPEND_NUMBER(PNG_NUMBER_FORMAT_02u, (unsigned)ptime->second);
- APPEND_STRING(" +0000"); /* This reliably terminates the buffer */
-
-# undef APPEND
-# undef APPEND_NUMBER
-# undef APPEND_STRING
- }
-
- return 1;
-}
-
-# if PNG_LIBPNG_VER < 10700
-/* To do: remove the following from libpng-1.7 */
-/* Original API that uses a private buffer in png_struct.
- * Deprecated because it causes png_struct to carry a spurious temporary
- * buffer (png_struct::time_buffer), better to have the caller pass this in.
- */
-png_const_charp PNGAPI
-png_convert_to_rfc1123(png_structrp png_ptr, png_const_timep ptime)
-{
- if (png_ptr != NULL)
- {
- /* The only failure above if png_ptr != NULL is from an invalid ptime */
- if (!png_convert_to_rfc1123_buffer(png_ptr->time_buffer, ptime))
- png_warning(png_ptr, "Ignoring invalid time value");
-
- else
- return png_ptr->time_buffer;
- }
-
- return NULL;
-}
-# endif
-# endif /* PNG_TIME_RFC1123_SUPPORTED */
-
-#endif /* defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) */
-
-png_const_charp PNGAPI
-png_get_copyright(png_const_structrp png_ptr)
-{
- PNG_UNUSED(png_ptr) /* Silence compiler warning about unused png_ptr */
-#ifdef PNG_STRING_COPYRIGHT
- return PNG_STRING_COPYRIGHT
-#else
-# ifdef __STDC__
- return PNG_STRING_NEWLINE \
- "libpng version 1.6.3 - July 18, 2013" PNG_STRING_NEWLINE \
- "Copyright (c) 1998-2013 Glenn Randers-Pehrson" PNG_STRING_NEWLINE \
- "Copyright (c) 1996-1997 Andreas Dilger" PNG_STRING_NEWLINE \
- "Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc." \
- PNG_STRING_NEWLINE;
-# else
- return "libpng version 1.6.3 - July 18, 2013\
- Copyright (c) 1998-2013 Glenn Randers-Pehrson\
- Copyright (c) 1996-1997 Andreas Dilger\
- Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.";
-# endif
-#endif
-}
-
-/* The following return the library version as a short string in the
- * format 1.0.0 through 99.99.99zz. To get the version of *.h files
- * used with your application, print out PNG_LIBPNG_VER_STRING, which
- * is defined in png.h.
- * Note: now there is no difference between png_get_libpng_ver() and
- * png_get_header_ver(). Due to the version_nn_nn_nn typedef guard,
- * it is guaranteed that png.c uses the correct version of png.h.
- */
-png_const_charp PNGAPI
-png_get_libpng_ver(png_const_structrp png_ptr)
-{
- /* Version of *.c files used when building libpng */
- return png_get_header_ver(png_ptr);
-}
-
-png_const_charp PNGAPI
-png_get_header_ver(png_const_structrp png_ptr)
-{
- /* Version of *.h files used when building libpng */
- PNG_UNUSED(png_ptr) /* Silence compiler warning about unused png_ptr */
- return PNG_LIBPNG_VER_STRING;
-}
-
-png_const_charp PNGAPI
-png_get_header_version(png_const_structrp png_ptr)
-{
- /* Returns longer string containing both version and date */
- PNG_UNUSED(png_ptr) /* Silence compiler warning about unused png_ptr */
-#ifdef __STDC__
- return PNG_HEADER_VERSION_STRING
-# ifndef PNG_READ_SUPPORTED
- " (NO READ SUPPORT)"
-# endif
- PNG_STRING_NEWLINE;
-#else
- return PNG_HEADER_VERSION_STRING;
-#endif
-}
-
-#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
-int PNGAPI
-png_handle_as_unknown(png_const_structrp png_ptr, png_const_bytep chunk_name)
-{
- /* Check chunk_name and return "keep" value if it's on the list, else 0 */
- png_const_bytep p, p_end;
-
- if (png_ptr == NULL || chunk_name == NULL || png_ptr->num_chunk_list == 0)
- return PNG_HANDLE_CHUNK_AS_DEFAULT;
-
- p_end = png_ptr->chunk_list;
- p = p_end + png_ptr->num_chunk_list*5; /* beyond end */
-
- /* The code is the fifth byte after each four byte string. Historically this
- * code was always searched from the end of the list, this is no longer
- * necessary because the 'set' routine handles duplicate entries correcty.
- */
- do /* num_chunk_list > 0, so at least one */
- {
- p -= 5;
-
- if (!memcmp(chunk_name, p, 4))
- return p[4];
- }
- while (p > p_end);
-
- /* This means that known chunks should be processed and unknown chunks should
- * be handled according to the value of png_ptr->unknown_default; this can be
- * confusing because, as a result, there are two levels of defaulting for
- * unknown chunks.
- */
- return PNG_HANDLE_CHUNK_AS_DEFAULT;
-}
-
-#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
-int /* PRIVATE */
-png_chunk_unknown_handling(png_const_structrp png_ptr, png_uint_32 chunk_name)
-{
- png_byte chunk_string[5];
-
- PNG_CSTRING_FROM_CHUNK(chunk_string, chunk_name);
- return png_handle_as_unknown(png_ptr, chunk_string);
-}
-#endif /* READ_UNKNOWN_CHUNKS */
-#endif /* SET_UNKNOWN_CHUNKS */
-
-#ifdef PNG_READ_SUPPORTED
-/* This function, added to libpng-1.0.6g, is untested. */
-int PNGAPI
-png_reset_zstream(png_structrp png_ptr)
-{
- if (png_ptr == NULL)
- return Z_STREAM_ERROR;
-
- /* WARNING: this resets the window bits to the maximum! */
- return (inflateReset(&png_ptr->zstream));
-}
-#endif /* PNG_READ_SUPPORTED */
-
-/* This function was added to libpng-1.0.7 */
-png_uint_32 PNGAPI
-png_access_version_number(void)
-{
- /* Version of *.c files used when building libpng */
- return((png_uint_32)PNG_LIBPNG_VER);
-}
-
-
-
-#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
-/* Ensure that png_ptr->zstream.msg holds some appropriate error message string.
- * If it doesn't 'ret' is used to set it to something appropriate, even in cases
- * like Z_OK or Z_STREAM_END where the error code is apparently a success code.
- */
-void /* PRIVATE */
-png_zstream_error(png_structrp png_ptr, int ret)
-{
- /* Translate 'ret' into an appropriate error string, priority is given to the
- * one in zstream if set. This always returns a string, even in cases like
- * Z_OK or Z_STREAM_END where the error code is a success code.
- */
- if (png_ptr->zstream.msg == NULL) switch (ret)
- {
- default:
- case Z_OK:
- png_ptr->zstream.msg = PNGZ_MSG_CAST("unexpected zlib return code");
- break;
-
- case Z_STREAM_END:
- /* Normal exit */
- png_ptr->zstream.msg = PNGZ_MSG_CAST("unexpected end of LZ stream");
- break;
-
- case Z_NEED_DICT:
- /* This means the deflate stream did not have a dictionary; this
- * indicates a bogus PNG.
- */
- png_ptr->zstream.msg = PNGZ_MSG_CAST("missing LZ dictionary");
- break;
-
- case Z_ERRNO:
- /* gz APIs only: should not happen */
- png_ptr->zstream.msg = PNGZ_MSG_CAST("zlib IO error");
- break;
-
- case Z_STREAM_ERROR:
- /* internal libpng error */
- png_ptr->zstream.msg = PNGZ_MSG_CAST("bad parameters to zlib");
- break;
-
- case Z_DATA_ERROR:
- png_ptr->zstream.msg = PNGZ_MSG_CAST("damaged LZ stream");
- break;
-
- case Z_MEM_ERROR:
- png_ptr->zstream.msg = PNGZ_MSG_CAST("insufficient memory");
- break;
-
- case Z_BUF_ERROR:
- /* End of input or output; not a problem if the caller is doing
- * incremental read or write.
- */
- png_ptr->zstream.msg = PNGZ_MSG_CAST("truncated");
- break;
-
- case Z_VERSION_ERROR:
- png_ptr->zstream.msg = PNGZ_MSG_CAST("unsupported zlib version");
- break;
-
- case PNG_UNEXPECTED_ZLIB_RETURN:
- /* Compile errors here mean that zlib now uses the value co-opted in
- * pngpriv.h for PNG_UNEXPECTED_ZLIB_RETURN; update the switch above
- * and change pngpriv.h. Note that this message is "... return",
- * whereas the default/Z_OK one is "... return code".
- */
- png_ptr->zstream.msg = PNGZ_MSG_CAST("unexpected zlib return");
- break;
- }
-}
-
-/* png_convert_size: a PNGAPI but no longer in png.h, so deleted
- * at libpng 1.5.5!
- */
-
-/* Added at libpng version 1.2.34 and 1.4.0 (moved from pngset.c) */
-#ifdef PNG_GAMMA_SUPPORTED /* always set if COLORSPACE */
-static int
-png_colorspace_check_gamma(png_const_structrp png_ptr,
- png_colorspacerp colorspace, png_fixed_point gAMA, int from)
- /* This is called to check a new gamma value against an existing one. The
- * routine returns false if the new gamma value should not be written.
- *
- * 'from' says where the new gamma value comes from:
- *
- * 0: the new gamma value is the libpng estimate for an ICC profile
- * 1: the new gamma value comes from a gAMA chunk
- * 2: the new gamma value comes from an sRGB chunk
- */
-{
- png_fixed_point gtest;
-
- if ((colorspace->flags & PNG_COLORSPACE_HAVE_GAMMA) != 0 &&
- (!png_muldiv(>est, colorspace->gamma, PNG_FP_1, gAMA) ||
- png_gamma_significant(gtest)))
- {
- /* Either this is an sRGB image, in which case the calculated gamma
- * approximation should match, or this is an image with a profile and the
- * value libpng calculates for the gamma of the profile does not match the
- * value recorded in the file. The former, sRGB, case is an error, the
- * latter is just a warning.
- */
- if ((colorspace->flags & PNG_COLORSPACE_FROM_sRGB) != 0 || from == 2)
- {
- png_chunk_report(png_ptr, "gamma value does not match sRGB",
- PNG_CHUNK_ERROR);
- /* Do not overwrite an sRGB value */
- return from == 2;
- }
-
- else /* sRGB tag not involved */
- {
- png_chunk_report(png_ptr, "gamma value does not match libpng estimate",
- PNG_CHUNK_WARNING);
- return from == 1;
- }
- }
-
- return 1;
-}
-
-void /* PRIVATE */
-png_colorspace_set_gamma(png_const_structrp png_ptr,
- png_colorspacerp colorspace, png_fixed_point gAMA)
-{
- /* Changed in libpng-1.5.4 to limit the values to ensure overflow can't
- * occur. Since the fixed point representation is assymetrical it is
- * possible for 1/gamma to overflow the limit of 21474 and this means the
- * gamma value must be at least 5/100000 and hence at most 20000.0. For
- * safety the limits here are a little narrower. The values are 0.00016 to
- * 6250.0, which are truly ridiculous gamma values (and will produce
- * displays that are all black or all white.)
- *
- * In 1.6.0 this test replaces the ones in pngrutil.c, in the gAMA chunk
- * handling code, which only required the value to be >0.
- */
- png_const_charp errmsg;
-
- if (gAMA < 16 || gAMA > 625000000)
- errmsg = "gamma value out of range";
-
-# ifdef PNG_READ_gAMA_SUPPORTED
- /* Allow the application to set the gamma value more than once */
- else if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0 &&
- (colorspace->flags & PNG_COLORSPACE_FROM_gAMA) != 0)
- errmsg = "duplicate";
-# endif
-
- /* Do nothing if the colorspace is already invalid */
- else if (colorspace->flags & PNG_COLORSPACE_INVALID)
- return;
-
- else
- {
- if (png_colorspace_check_gamma(png_ptr, colorspace, gAMA, 1/*from gAMA*/))
- {
- /* Store this gamma value. */
- colorspace->gamma = gAMA;
- colorspace->flags |=
- (PNG_COLORSPACE_HAVE_GAMMA | PNG_COLORSPACE_FROM_gAMA);
- }
-
- /* At present if the check_gamma test fails the gamma of the colorspace is
- * not updated however the colorspace is not invalidated. This
- * corresponds to the case where the existing gamma comes from an sRGB
- * chunk or profile. An error message has already been output.
- */
- return;
- }
-
- /* Error exit - errmsg has been set. */
- colorspace->flags |= PNG_COLORSPACE_INVALID;
- png_chunk_report(png_ptr, errmsg, PNG_CHUNK_WRITE_ERROR);
-}
-
-void /* PRIVATE */
-png_colorspace_sync_info(png_const_structrp png_ptr, png_inforp info_ptr)
-{
- if (info_ptr->colorspace.flags & PNG_COLORSPACE_INVALID)
- {
- /* Everything is invalid */
- info_ptr->valid &= ~(PNG_INFO_gAMA|PNG_INFO_cHRM|PNG_INFO_sRGB|
- PNG_INFO_iCCP);
-
-# ifdef PNG_COLORSPACE_SUPPORTED
- /* Clean up the iCCP profile now if it won't be used. */
- png_free_data(png_ptr, info_ptr, PNG_FREE_ICCP, -1/*not used*/);
-# else
- PNG_UNUSED(png_ptr)
-# endif
- }
-
- else
- {
-# ifdef PNG_COLORSPACE_SUPPORTED
- /* Leave the INFO_iCCP flag set if the pngset.c code has already set
- * it; this allows a PNG to contain a profile which matches sRGB and
- * yet still have that profile retrievable by the application.
- */
- if (info_ptr->colorspace.flags & PNG_COLORSPACE_MATCHES_sRGB)
- info_ptr->valid |= PNG_INFO_sRGB;
-
- else
- info_ptr->valid &= ~PNG_INFO_sRGB;
-
- if (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_ENDPOINTS)
- info_ptr->valid |= PNG_INFO_cHRM;
-
- else
- info_ptr->valid &= ~PNG_INFO_cHRM;
-# endif
-
- if (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_GAMMA)
- info_ptr->valid |= PNG_INFO_gAMA;
-
- else
- info_ptr->valid &= ~PNG_INFO_gAMA;
- }
-}
-
-#ifdef PNG_READ_SUPPORTED
-void /* PRIVATE */
-png_colorspace_sync(png_const_structrp png_ptr, png_inforp info_ptr)
-{
- if (info_ptr == NULL) /* reduce code size; check here not in the caller */
- return;
-
- info_ptr->colorspace = png_ptr->colorspace;
- png_colorspace_sync_info(png_ptr, info_ptr);
-}
-#endif
-#endif
-
-#ifdef PNG_COLORSPACE_SUPPORTED
-/* Added at libpng-1.5.5 to support read and write of true CIEXYZ values for
- * cHRM, as opposed to using chromaticities. These internal APIs return
- * non-zero on a parameter error. The X, Y and Z values are required to be
- * positive and less than 1.0.
- */
-static int
-png_xy_from_XYZ(png_xy *xy, const png_XYZ *XYZ)
-{
- png_int_32 d, dwhite, whiteX, whiteY;
-
- d = XYZ->red_X + XYZ->red_Y + XYZ->red_Z;
- if (!png_muldiv(&xy->redx, XYZ->red_X, PNG_FP_1, d)) return 1;
- if (!png_muldiv(&xy->redy, XYZ->red_Y, PNG_FP_1, d)) return 1;
- dwhite = d;
- whiteX = XYZ->red_X;
- whiteY = XYZ->red_Y;
-
- d = XYZ->green_X + XYZ->green_Y + XYZ->green_Z;
- if (!png_muldiv(&xy->greenx, XYZ->green_X, PNG_FP_1, d)) return 1;
- if (!png_muldiv(&xy->greeny, XYZ->green_Y, PNG_FP_1, d)) return 1;
- dwhite += d;
- whiteX += XYZ->green_X;
- whiteY += XYZ->green_Y;
-
- d = XYZ->blue_X + XYZ->blue_Y + XYZ->blue_Z;
- if (!png_muldiv(&xy->bluex, XYZ->blue_X, PNG_FP_1, d)) return 1;
- if (!png_muldiv(&xy->bluey, XYZ->blue_Y, PNG_FP_1, d)) return 1;
- dwhite += d;
- whiteX += XYZ->blue_X;
- whiteY += XYZ->blue_Y;
-
- /* The reference white is simply the sum of the end-point (X,Y,Z) vectors,
- * thus:
- */
- if (!png_muldiv(&xy->whitex, whiteX, PNG_FP_1, dwhite)) return 1;
- if (!png_muldiv(&xy->whitey, whiteY, PNG_FP_1, dwhite)) return 1;
-
- return 0;
-}
-
-static int
-png_XYZ_from_xy(png_XYZ *XYZ, const png_xy *xy)
-{
- png_fixed_point red_inverse, green_inverse, blue_scale;
- png_fixed_point left, right, denominator;
-
- /* Check xy and, implicitly, z. Note that wide gamut color spaces typically
- * have end points with 0 tristimulus values (these are impossible end
- * points, but they are used to cover the possible colors.)
- */
- if (xy->redx < 0 || xy->redx > PNG_FP_1) return 1;
- if (xy->redy < 0 || xy->redy > PNG_FP_1-xy->redx) return 1;
- if (xy->greenx < 0 || xy->greenx > PNG_FP_1) return 1;
- if (xy->greeny < 0 || xy->greeny > PNG_FP_1-xy->greenx) return 1;
- if (xy->bluex < 0 || xy->bluex > PNG_FP_1) return 1;
- if (xy->bluey < 0 || xy->bluey > PNG_FP_1-xy->bluex) return 1;
- if (xy->whitex < 0 || xy->whitex > PNG_FP_1) return 1;
- if (xy->whitey < 0 || xy->whitey > PNG_FP_1-xy->whitex) return 1;
-
- /* The reverse calculation is more difficult because the original tristimulus
- * value had 9 independent values (red,green,blue)x(X,Y,Z) however only 8
- * derived values were recorded in the cHRM chunk;
- * (red,green,blue,white)x(x,y). This loses one degree of freedom and
- * therefore an arbitrary ninth value has to be introduced to undo the
- * original transformations.
- *
- * Think of the original end-points as points in (X,Y,Z) space. The
- * chromaticity values (c) have the property:
- *
- * C
- * c = ---------
- * X + Y + Z
- *
- * For each c (x,y,z) from the corresponding original C (X,Y,Z). Thus the
- * three chromaticity values (x,y,z) for each end-point obey the
- * relationship:
- *
- * x + y + z = 1
- *
- * This describes the plane in (X,Y,Z) space that intersects each axis at the
- * value 1.0; call this the chromaticity plane. Thus the chromaticity
- * calculation has scaled each end-point so that it is on the x+y+z=1 plane
- * and chromaticity is the intersection of the vector from the origin to the
- * (X,Y,Z) value with the chromaticity plane.
- *
- * To fully invert the chromaticity calculation we would need the three
- * end-point scale factors, (red-scale, green-scale, blue-scale), but these
- * were not recorded. Instead we calculated the reference white (X,Y,Z) and
- * recorded the chromaticity of this. The reference white (X,Y,Z) would have
- * given all three of the scale factors since:
- *
- * color-C = color-c * color-scale
- * white-C = red-C + green-C + blue-C
- * = red-c*red-scale + green-c*green-scale + blue-c*blue-scale
- *
- * But cHRM records only white-x and white-y, so we have lost the white scale
- * factor:
- *
- * white-C = white-c*white-scale
- *
- * To handle this the inverse transformation makes an arbitrary assumption
- * about white-scale:
- *
- * Assume: white-Y = 1.0
- * Hence: white-scale = 1/white-y
- * Or: red-Y + green-Y + blue-Y = 1.0
- *
- * Notice the last statement of the assumption gives an equation in three of
- * the nine values we want to calculate. 8 more equations come from the
- * above routine as summarised at the top above (the chromaticity
- * calculation):
- *
- * Given: color-x = color-X / (color-X + color-Y + color-Z)
- * Hence: (color-x - 1)*color-X + color.x*color-Y + color.x*color-Z = 0
- *
- * This is 9 simultaneous equations in the 9 variables "color-C" and can be
- * solved by Cramer's rule. Cramer's rule requires calculating 10 9x9 matrix
- * determinants, however this is not as bad as it seems because only 28 of
- * the total of 90 terms in the various matrices are non-zero. Nevertheless
- * Cramer's rule is notoriously numerically unstable because the determinant
- * calculation involves the difference of large, but similar, numbers. It is
- * difficult to be sure that the calculation is stable for real world values
- * and it is certain that it becomes unstable where the end points are close
- * together.
- *
- * So this code uses the perhaps slightly less optimal but more
- * understandable and totally obvious approach of calculating color-scale.
- *
- * This algorithm depends on the precision in white-scale and that is
- * (1/white-y), so we can immediately see that as white-y approaches 0 the
- * accuracy inherent in the cHRM chunk drops off substantially.
- *
- * libpng arithmetic: a simple invertion of the above equations
- * ------------------------------------------------------------
- *
- * white_scale = 1/white-y
- * white-X = white-x * white-scale
- * white-Y = 1.0
- * white-Z = (1 - white-x - white-y) * white_scale
- *
- * white-C = red-C + green-C + blue-C
- * = red-c*red-scale + green-c*green-scale + blue-c*blue-scale
- *
- * This gives us three equations in (red-scale,green-scale,blue-scale) where
- * all the coefficients are now known:
- *
- * red-x*red-scale + green-x*green-scale + blue-x*blue-scale
- * = white-x/white-y
- * red-y*red-scale + green-y*green-scale + blue-y*blue-scale = 1
- * red-z*red-scale + green-z*green-scale + blue-z*blue-scale
- * = (1 - white-x - white-y)/white-y
- *
- * In the last equation color-z is (1 - color-x - color-y) so we can add all
- * three equations together to get an alternative third:
- *
- * red-scale + green-scale + blue-scale = 1/white-y = white-scale
- *
- * So now we have a Cramer's rule solution where the determinants are just
- * 3x3 - far more tractible. Unfortunately 3x3 determinants still involve
- * multiplication of three coefficients so we can't guarantee to avoid
- * overflow in the libpng fixed point representation. Using Cramer's rule in
- * floating point is probably a good choice here, but it's not an option for
- * fixed point. Instead proceed to simplify the first two equations by
- * eliminating what is likely to be the largest value, blue-scale:
- *
- * blue-scale = white-scale - red-scale - green-scale
- *
- * Hence:
- *
- * (red-x - blue-x)*red-scale + (green-x - blue-x)*green-scale =
- * (white-x - blue-x)*white-scale
- *
- * (red-y - blue-y)*red-scale + (green-y - blue-y)*green-scale =
- * 1 - blue-y*white-scale
- *
- * And now we can trivially solve for (red-scale,green-scale):
- *
- * green-scale =
- * (white-x - blue-x)*white-scale - (red-x - blue-x)*red-scale
- * -----------------------------------------------------------
- * green-x - blue-x
- *
- * red-scale =
- * 1 - blue-y*white-scale - (green-y - blue-y) * green-scale
- * ---------------------------------------------------------
- * red-y - blue-y
- *
- * Hence:
- *
- * red-scale =
- * ( (green-x - blue-x) * (white-y - blue-y) -
- * (green-y - blue-y) * (white-x - blue-x) ) / white-y
- * -------------------------------------------------------------------------
- * (green-x - blue-x)*(red-y - blue-y)-(green-y - blue-y)*(red-x - blue-x)
- *
- * green-scale =
- * ( (red-y - blue-y) * (white-x - blue-x) -
- * (red-x - blue-x) * (white-y - blue-y) ) / white-y
- * -------------------------------------------------------------------------
- * (green-x - blue-x)*(red-y - blue-y)-(green-y - blue-y)*(red-x - blue-x)
- *
- * Accuracy:
- * The input values have 5 decimal digits of accuracy. The values are all in
- * the range 0 < value < 1, so simple products are in the same range but may
- * need up to 10 decimal digits to preserve the original precision and avoid
- * underflow. Because we are using a 32-bit signed representation we cannot
- * match this; the best is a little over 9 decimal digits, less than 10.
- *
- * The approach used here is to preserve the maximum precision within the
- * signed representation. Because the red-scale calculation above uses the
- * difference between two products of values that must be in the range -1..+1
- * it is sufficient to divide the product by 7; ceil(100,000/32767*2). The
- * factor is irrelevant in the calculation because it is applied to both
- * numerator and denominator.
- *
- * Note that the values of the differences of the products of the
- * chromaticities in the above equations tend to be small, for example for
- * the sRGB chromaticities they are:
- *
- * red numerator: -0.04751
- * green numerator: -0.08788
- * denominator: -0.2241 (without white-y multiplication)
- *
- * The resultant Y coefficients from the chromaticities of some widely used
- * color space definitions are (to 15 decimal places):
- *
- * sRGB
- * 0.212639005871510 0.715168678767756 0.072192315360734
- * Kodak ProPhoto
- * 0.288071128229293 0.711843217810102 0.000085653960605
- * Adobe RGB
- * 0.297344975250536 0.627363566255466 0.075291458493998
- * Adobe Wide Gamut RGB
- * 0.258728243040113 0.724682314948566 0.016589442011321
- */
- /* By the argument, above overflow should be impossible here. The return
- * value of 2 indicates an internal error to the caller.
- */
- if (!png_muldiv(&left, xy->greenx-xy->bluex, xy->redy - xy->bluey, 7))
- return 2;
- if (!png_muldiv(&right, xy->greeny-xy->bluey, xy->redx - xy->bluex, 7))
- return 2;
- denominator = left - right;
-
- /* Now find the red numerator. */
- if (!png_muldiv(&left, xy->greenx-xy->bluex, xy->whitey-xy->bluey, 7))
- return 2;
- if (!png_muldiv(&right, xy->greeny-xy->bluey, xy->whitex-xy->bluex, 7))
- return 2;
-
- /* Overflow is possible here and it indicates an extreme set of PNG cHRM
- * chunk values. This calculation actually returns the reciprocal of the
- * scale value because this allows us to delay the multiplication of white-y
- * into the denominator, which tends to produce a small number.
- */
- if (!png_muldiv(&red_inverse, xy->whitey, denominator, left-right) ||
- red_inverse <= xy->whitey /* r+g+b scales = white scale */)
- return 1;
-
- /* Similarly for green_inverse: */
- if (!png_muldiv(&left, xy->redy-xy->bluey, xy->whitex-xy->bluex, 7))
- return 2;
- if (!png_muldiv(&right, xy->redx-xy->bluex, xy->whitey-xy->bluey, 7))
- return 2;
- if (!png_muldiv(&green_inverse, xy->whitey, denominator, left-right) ||
- green_inverse <= xy->whitey)
- return 1;
-
- /* And the blue scale, the checks above guarantee this can't overflow but it
- * can still produce 0 for extreme cHRM values.
- */
- blue_scale = png_reciprocal(xy->whitey) - png_reciprocal(red_inverse) -
- png_reciprocal(green_inverse);
- if (blue_scale <= 0) return 1;
-
-
- /* And fill in the png_XYZ: */
- if (!png_muldiv(&XYZ->red_X, xy->redx, PNG_FP_1, red_inverse)) return 1;
- if (!png_muldiv(&XYZ->red_Y, xy->redy, PNG_FP_1, red_inverse)) return 1;
- if (!png_muldiv(&XYZ->red_Z, PNG_FP_1 - xy->redx - xy->redy, PNG_FP_1,
- red_inverse))
- return 1;
-
- if (!png_muldiv(&XYZ->green_X, xy->greenx, PNG_FP_1, green_inverse))
- return 1;
- if (!png_muldiv(&XYZ->green_Y, xy->greeny, PNG_FP_1, green_inverse))
- return 1;
- if (!png_muldiv(&XYZ->green_Z, PNG_FP_1 - xy->greenx - xy->greeny, PNG_FP_1,
- green_inverse))
- return 1;
-
- if (!png_muldiv(&XYZ->blue_X, xy->bluex, blue_scale, PNG_FP_1)) return 1;
- if (!png_muldiv(&XYZ->blue_Y, xy->bluey, blue_scale, PNG_FP_1)) return 1;
- if (!png_muldiv(&XYZ->blue_Z, PNG_FP_1 - xy->bluex - xy->bluey, blue_scale,
- PNG_FP_1))
- return 1;
-
- return 0; /*success*/
-}
-
-static int
-png_XYZ_normalize(png_XYZ *XYZ)
-{
- png_int_32 Y;
-
- if (XYZ->red_Y < 0 || XYZ->green_Y < 0 || XYZ->blue_Y < 0 ||
- XYZ->red_X < 0 || XYZ->green_X < 0 || XYZ->blue_X < 0 ||
- XYZ->red_Z < 0 || XYZ->green_Z < 0 || XYZ->blue_Z < 0)
- return 1;
-
- /* Normalize by scaling so the sum of the end-point Y values is PNG_FP_1.
- * IMPLEMENTATION NOTE: ANSI requires signed overflow not to occur, therefore
- * relying on addition of two positive values producing a negative one is not
- * safe.
- */
- Y = XYZ->red_Y;
- if (0x7fffffff - Y < XYZ->green_X) return 1;
- Y += XYZ->green_Y;
- if (0x7fffffff - Y < XYZ->blue_X) return 1;
- Y += XYZ->blue_Y;
-
- if (Y != PNG_FP_1)
- {
- if (!png_muldiv(&XYZ->red_X, XYZ->red_X, PNG_FP_1, Y)) return 1;
- if (!png_muldiv(&XYZ->red_Y, XYZ->red_Y, PNG_FP_1, Y)) return 1;
- if (!png_muldiv(&XYZ->red_Z, XYZ->red_Z, PNG_FP_1, Y)) return 1;
-
- if (!png_muldiv(&XYZ->green_X, XYZ->green_X, PNG_FP_1, Y)) return 1;
- if (!png_muldiv(&XYZ->green_Y, XYZ->green_Y, PNG_FP_1, Y)) return 1;
- if (!png_muldiv(&XYZ->green_Z, XYZ->green_Z, PNG_FP_1, Y)) return 1;
-
- if (!png_muldiv(&XYZ->blue_X, XYZ->blue_X, PNG_FP_1, Y)) return 1;
- if (!png_muldiv(&XYZ->blue_Y, XYZ->blue_Y, PNG_FP_1, Y)) return 1;
- if (!png_muldiv(&XYZ->blue_Z, XYZ->blue_Z, PNG_FP_1, Y)) return 1;
- }
-
- return 0;
-}
-
-static int
-png_colorspace_endpoints_match(const png_xy *xy1, const png_xy *xy2, int delta)
-{
- /* Allow an error of +/-0.01 (absolute value) on each chromaticity */
- return !(PNG_OUT_OF_RANGE(xy1->whitex, xy2->whitex,delta) ||
- PNG_OUT_OF_RANGE(xy1->whitey, xy2->whitey,delta) ||
- PNG_OUT_OF_RANGE(xy1->redx, xy2->redx, delta) ||
- PNG_OUT_OF_RANGE(xy1->redy, xy2->redy, delta) ||
- PNG_OUT_OF_RANGE(xy1->greenx, xy2->greenx,delta) ||
- PNG_OUT_OF_RANGE(xy1->greeny, xy2->greeny,delta) ||
- PNG_OUT_OF_RANGE(xy1->bluex, xy2->bluex, delta) ||
- PNG_OUT_OF_RANGE(xy1->bluey, xy2->bluey, delta));
-}
-
-/* Added in libpng-1.6.0, a different check for the validity of a set of cHRM
- * chunk chromaticities. Earlier checks used to simply look for the overflow
- * condition (where the determinant of the matrix to solve for XYZ ends up zero
- * because the chromaticity values are not all distinct.) Despite this it is
- * theoretically possible to produce chromaticities that are apparently valid
- * but that rapidly degrade to invalid, potentially crashing, sets because of
- * arithmetic inaccuracies when calculations are performed on them. The new
- * check is to round-trip xy -> XYZ -> xy and then check that the result is
- * within a small percentage of the original.
- */
-static int
-png_colorspace_check_xy(png_XYZ *XYZ, const png_xy *xy)
-{
- int result;
- png_xy xy_test;
-
- /* As a side-effect this routine also returns the XYZ endpoints. */
- result = png_XYZ_from_xy(XYZ, xy);
- if (result) return result;
-
- result = png_xy_from_XYZ(&xy_test, XYZ);
- if (result) return result;
-
- if (png_colorspace_endpoints_match(xy, &xy_test,
- 5/*actually, the math is pretty accurate*/))
- return 0;
-
- /* Too much slip */
- return 1;
-}
-
-/* This is the check going the other way. The XYZ is modified to normalize it
- * (another side-effect) and the xy chromaticities are returned.
- */
-static int
-png_colorspace_check_XYZ(png_xy *xy, png_XYZ *XYZ)
-{
- int result;
- png_XYZ XYZtemp;
-
- result = png_XYZ_normalize(XYZ);
- if (result) return result;
-
- result = png_xy_from_XYZ(xy, XYZ);
- if (result) return result;
-
- XYZtemp = *XYZ;
- return png_colorspace_check_xy(&XYZtemp, xy);
-}
-
-/* Used to check for an endpoint match against sRGB */
-static const png_xy sRGB_xy = /* From ITU-R BT.709-3 */
-{
- /* color x y */
- /* red */ 64000, 33000,
- /* green */ 30000, 60000,
- /* blue */ 15000, 6000,
- /* white */ 31270, 32900
-};
-
-static int
-png_colorspace_set_xy_and_XYZ(png_const_structrp png_ptr,
- png_colorspacerp colorspace, const png_xy *xy, const png_XYZ *XYZ,
- int preferred)
-{
- if (colorspace->flags & PNG_COLORSPACE_INVALID)
- return 0;
-
- /* The consistency check is performed on the chromaticities; this factors out
- * variations because of the normalization (or not) of the end point Y
- * values.
- */
- if (preferred < 2 && (colorspace->flags & PNG_COLORSPACE_HAVE_ENDPOINTS))
- {
- /* The end points must be reasonably close to any we already have. The
- * following allows an error of up to +/-.001
- */
- if (!png_colorspace_endpoints_match(xy, &colorspace->end_points_xy, 100))
- {
- colorspace->flags |= PNG_COLORSPACE_INVALID;
- png_benign_error(png_ptr, "inconsistent chromaticities");
- return 0; /* failed */
- }
-
- /* Only overwrite with preferred values */
- if (!preferred)
- return 1; /* ok, but no change */
- }
-
- colorspace->end_points_xy = *xy;
- colorspace->end_points_XYZ = *XYZ;
- colorspace->flags |= PNG_COLORSPACE_HAVE_ENDPOINTS;
-
- /* The end points are normally quoted to two decimal digits, so allow +/-0.01
- * on this test.
- */
- if (png_colorspace_endpoints_match(xy, &sRGB_xy, 1000))
- colorspace->flags |= PNG_COLORSPACE_ENDPOINTS_MATCH_sRGB;
-
- else
- colorspace->flags &= PNG_COLORSPACE_CANCEL(
- PNG_COLORSPACE_ENDPOINTS_MATCH_sRGB);
-
- return 2; /* ok and changed */
-}
-
-int /* PRIVATE */
-png_colorspace_set_chromaticities(png_const_structrp png_ptr,
- png_colorspacerp colorspace, const png_xy *xy, int preferred)
-{
- /* We must check the end points to ensure they are reasonable - in the past
- * color management systems have crashed as a result of getting bogus
- * colorant values, while this isn't the fault of libpng it is the
- * responsibility of libpng because PNG carries the bomb and libpng is in a
- * position to protect against it.
- */
- png_XYZ XYZ;
-
- switch (png_colorspace_check_xy(&XYZ, xy))
- {
- case 0: /* success */
- return png_colorspace_set_xy_and_XYZ(png_ptr, colorspace, xy, &XYZ,
- preferred);
-
- case 1:
- /* We can't invert the chromaticities so we can't produce value XYZ
- * values. Likely as not a color management system will fail too.
- */
- colorspace->flags |= PNG_COLORSPACE_INVALID;
- png_benign_error(png_ptr, "invalid chromaticities");
- break;
-
- default:
- /* libpng is broken; this should be a warning but if it happens we
- * want error reports so for the moment it is an error.
- */
- colorspace->flags |= PNG_COLORSPACE_INVALID;
- png_error(png_ptr, "internal error checking chromaticities");
- break;
- }
-
- return 0; /* failed */
-}
-
-int /* PRIVATE */
-png_colorspace_set_endpoints(png_const_structrp png_ptr,
- png_colorspacerp colorspace, const png_XYZ *XYZ_in, int preferred)
-{
- png_XYZ XYZ = *XYZ_in;
- png_xy xy;
-
- switch (png_colorspace_check_XYZ(&xy, &XYZ))
- {
- case 0:
- return png_colorspace_set_xy_and_XYZ(png_ptr, colorspace, &xy, &XYZ,
- preferred);
-
- case 1:
- /* End points are invalid. */
- colorspace->flags |= PNG_COLORSPACE_INVALID;
- png_benign_error(png_ptr, "invalid end points");
- break;
-
- default:
- colorspace->flags |= PNG_COLORSPACE_INVALID;
- png_error(png_ptr, "internal error checking chromaticities");
- break;
- }
-
- return 0; /* failed */
-}
-
-#if defined(PNG_sRGB_SUPPORTED) || defined(PNG_iCCP_SUPPORTED)
-/* Error message generation */
-static char
-png_icc_tag_char(png_uint_32 byte)
-{
- byte &= 0xff;
- if (byte >= 32 && byte <= 126)
- return (char)byte;
- else
- return '?';
-}
-
-static void
-png_icc_tag_name(char *name, png_uint_32 tag)
-{
- name[0] = '\'';
- name[1] = png_icc_tag_char(tag >> 24);
- name[2] = png_icc_tag_char(tag >> 16);
- name[3] = png_icc_tag_char(tag >> 8);
- name[4] = png_icc_tag_char(tag );
- name[5] = '\'';
-}
-
-static int
-is_ICC_signature_char(png_alloc_size_t it)
-{
- return it == 32 || (it >= 48 && it <= 57) || (it >= 65 && it <= 90) ||
- (it >= 97 && it <= 122);
-}
-
-static int is_ICC_signature(png_alloc_size_t it)
-{
- return is_ICC_signature_char(it >> 24) /* checks all the top bits */ &&
- is_ICC_signature_char((it >> 16) & 0xff) &&
- is_ICC_signature_char((it >> 8) & 0xff) &&
- is_ICC_signature_char(it & 0xff);
-}
-
-static int
-png_icc_profile_error(png_const_structrp png_ptr, png_colorspacerp colorspace,
- png_const_charp name, png_alloc_size_t value, png_const_charp reason)
-{
- size_t pos;
- char message[196]; /* see below for calculation */
-
- if (colorspace != NULL)
- colorspace->flags |= PNG_COLORSPACE_INVALID;
-
- pos = png_safecat(message, (sizeof message), 0, "profile '"); /* 9 chars */
- pos = png_safecat(message, pos+79, pos, name); /* Truncate to 79 chars */
- pos = png_safecat(message, (sizeof message), pos, "': "); /* +2 = 90 */
- if (is_ICC_signature(value))
- {
- /* So 'value' is at most 4 bytes and the following cast is safe */
- png_icc_tag_name(message+pos, (png_uint_32)value);
- pos += 6; /* total +8; less than the else clause */
- message[pos++] = ':';
- message[pos++] = ' ';
- }
-# ifdef PNG_WARNINGS_SUPPORTED
- else
- {
- char number[PNG_NUMBER_BUFFER_SIZE]; /* +24 = 114*/
-
- pos = png_safecat(message, (sizeof message), pos,
- png_format_number(number, number+(sizeof number),
- PNG_NUMBER_FORMAT_x, value));
- pos = png_safecat(message, (sizeof message), pos, "h: "); /*+2 = 116*/
- }
-# endif
- /* The 'reason' is an arbitrary message, allow +79 maximum 195 */
- pos = png_safecat(message, (sizeof message), pos, reason);
-
- /* This is recoverable, but make it unconditionally an app_error on write to
- * avoid writing invalid ICC profiles into PNG files. (I.e. we handle them
- * on read, with a warning, but on write unless the app turns off
- * application errors the PNG won't be written.)
- */
- png_chunk_report(png_ptr, message,
- (colorspace != NULL) ? PNG_CHUNK_ERROR : PNG_CHUNK_WRITE_ERROR);
-
- return 0;
-}
-#endif /* sRGB || iCCP */
-
-#ifdef PNG_sRGB_SUPPORTED
-int /* PRIVATE */
-png_colorspace_set_sRGB(png_const_structrp png_ptr, png_colorspacerp colorspace,
- int intent)
-{
- /* sRGB sets known gamma, end points and (from the chunk) intent. */
- /* IMPORTANT: these are not necessarily the values found in an ICC profile
- * because ICC profiles store values adapted to a D50 environment; it is
- * expected that the ICC profile mediaWhitePointTag will be D50, see the
- * checks and code elsewhere to understand this better.
- *
- * These XYZ values, which are accurate to 5dp, produce rgb to gray
- * coefficients of (6968,23435,2366), which are reduced (because they add up
- * to 32769 not 32768) to (6968,23434,2366). These are the values that
- * libpng has traditionally used (and are the best values given the 15bit
- * algorithm used by the rgb to gray code.)
- */
- static const png_XYZ sRGB_XYZ = /* D65 XYZ (*not* the D50 adapted values!) */
- {
- /* color X Y Z */
- /* red */ 41239, 21264, 1933,
- /* green */ 35758, 71517, 11919,
- /* blue */ 18048, 7219, 95053
- };
-
- /* Do nothing if the colorspace is already invalidated. */
- if (colorspace->flags & PNG_COLORSPACE_INVALID)
- return 0;
-
- /* Check the intent, then check for existing settings. It is valid for the
- * PNG file to have cHRM or gAMA chunks along with sRGB, but the values must
- * be consistent with the correct values. If, however, this function is
- * called below because an iCCP chunk matches sRGB then it is quite
- * conceivable that an older app recorded incorrect gAMA and cHRM because of
- * an incorrect calculation based on the values in the profile - this does
- * *not* invalidate the profile (though it still produces an error, which can
- * be ignored.)
- */
- if (intent < 0 || intent >= PNG_sRGB_INTENT_LAST)
- return png_icc_profile_error(png_ptr, colorspace, "sRGB",
- (unsigned)intent, "invalid sRGB rendering intent");
-
- if ((colorspace->flags & PNG_COLORSPACE_HAVE_INTENT) != 0 &&
- colorspace->rendering_intent != intent)
- return png_icc_profile_error(png_ptr, colorspace, "sRGB",
- (unsigned)intent, "inconsistent rendering intents");
-
- if ((colorspace->flags & PNG_COLORSPACE_FROM_sRGB) != 0)
- {
- png_benign_error(png_ptr, "duplicate sRGB information ignored");
- return 0;
- }
-
- /* If the standard sRGB cHRM chunk does not match the one from the PNG file
- * warn but overwrite the value with the correct one.
- */
- if ((colorspace->flags & PNG_COLORSPACE_HAVE_ENDPOINTS) != 0 &&
- !png_colorspace_endpoints_match(&sRGB_xy, &colorspace->end_points_xy,
- 100))
- png_chunk_report(png_ptr, "cHRM chunk does not match sRGB",
- PNG_CHUNK_ERROR);
-
- /* This check is just done for the error reporting - the routine always
- * returns true when the 'from' argument corresponds to sRGB (2).
- */
- (void)png_colorspace_check_gamma(png_ptr, colorspace, PNG_GAMMA_sRGB_INVERSE,
- 2/*from sRGB*/);
-
- /* intent: bugs in GCC force 'int' to be used as the parameter type. */
- colorspace->rendering_intent = (png_uint_16)intent;
- colorspace->flags |= PNG_COLORSPACE_HAVE_INTENT;
-
- /* endpoints */
- colorspace->end_points_xy = sRGB_xy;
- colorspace->end_points_XYZ = sRGB_XYZ;
- colorspace->flags |=
- (PNG_COLORSPACE_HAVE_ENDPOINTS|PNG_COLORSPACE_ENDPOINTS_MATCH_sRGB);
-
- /* gamma */
- colorspace->gamma = PNG_GAMMA_sRGB_INVERSE;
- colorspace->flags |= PNG_COLORSPACE_HAVE_GAMMA;
-
- /* Finally record that we have an sRGB profile */
- colorspace->flags |=
- (PNG_COLORSPACE_MATCHES_sRGB|PNG_COLORSPACE_FROM_sRGB);
-
- return 1; /* set */
-}
-#endif /* sRGB */
-
-#ifdef PNG_iCCP_SUPPORTED
-/* Encoded value of D50 as an ICC XYZNumber. From the ICC 2010 spec the value
- * is XYZ(0.9642,1.0,0.8249), which scales to:
- *
- * (63189.8112, 65536, 54060.6464)
- */
-static const png_byte D50_nCIEXYZ[12] =
- { 0x00, 0x00, 0xf6, 0xd6, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0xd3, 0x2d };
-
-int /* PRIVATE */
-png_icc_check_length(png_const_structrp png_ptr, png_colorspacerp colorspace,
- png_const_charp name, png_uint_32 profile_length)
-{
- if (profile_length < 132)
- return png_icc_profile_error(png_ptr, colorspace, name, profile_length,
- "too short");
-
- if (profile_length & 3)
- return png_icc_profile_error(png_ptr, colorspace, name, profile_length,
- "invalid length");
-
- return 1;
-}
-
-int /* PRIVATE */
-png_icc_check_header(png_const_structrp png_ptr, png_colorspacerp colorspace,
- png_const_charp name, png_uint_32 profile_length,
- png_const_bytep profile/* first 132 bytes only */, int color_type)
-{
- png_uint_32 temp;
-
- /* Length check; this cannot be ignored in this code because profile_length
- * is used later to check the tag table, so even if the profile seems over
- * long profile_length from the caller must be correct. The caller can fix
- * this up on read or write by just passing in the profile header length.
- */
- temp = png_get_uint_32(profile);
- if (temp != profile_length)
- return png_icc_profile_error(png_ptr, colorspace, name, temp,
- "length does not match profile");
-
- temp = png_get_uint_32(profile+128); /* tag count: 12 bytes/tag */
- if (temp > 357913930 || /* (2^32-4-132)/12: maximum possible tag count */
- profile_length < 132+12*temp) /* truncated tag table */
- return png_icc_profile_error(png_ptr, colorspace, name, temp,
- "tag count too large");
-
- /* The 'intent' must be valid or we can't store it, ICC limits the intent to
- * 16 bits.
- */
- temp = png_get_uint_32(profile+64);
- if (temp >= 0xffff) /* The ICC limit */
- return png_icc_profile_error(png_ptr, colorspace, name, temp,
- "invalid rendering intent");
-
- /* This is just a warning because the profile may be valid in future
- * versions.
- */
- if (temp >= PNG_sRGB_INTENT_LAST)
- (void)png_icc_profile_error(png_ptr, NULL, name, temp,
- "intent outside defined range");
-
- /* At this point the tag table can't be checked because it hasn't necessarily
- * been loaded; however, various header fields can be checked. These checks
- * are for values permitted by the PNG spec in an ICC profile; the PNG spec
- * restricts the profiles that can be passed in an iCCP chunk (they must be
- * appropriate to processing PNG data!)
- */
-
- /* Data checks (could be skipped). These checks must be independent of the
- * version number; however, the version number doesn't accomodate changes in
- * the header fields (just the known tags and the interpretation of the
- * data.)
- */
- temp = png_get_uint_32(profile+36); /* signature 'ascp' */
- if (temp != 0x61637370)
- return png_icc_profile_error(png_ptr, colorspace, name, temp,
- "invalid signature");
-
- /* Currently the PCS illuminant/adopted white point (the computational
- * white point) are required to be D50,
- * however the profile contains a record of the illuminant so perhaps ICC
- * expects to be able to change this in the future (despite the rationale in
- * the introduction for using a fixed PCS adopted white.) Consequently the
- * following is just a warning.
- */
- if (memcmp(profile+68, D50_nCIEXYZ, 12) != 0)
- (void)png_icc_profile_error(png_ptr, NULL, name, 0/*no tag value*/,
- "PCS illuminant is not D50");
-
- /* The PNG spec requires this:
- * "If the iCCP chunk is present, the image samples conform to the colour
- * space represented by the embedded ICC profile as defined by the
- * International Color Consortium [ICC]. The colour space of the ICC profile
- * shall be an RGB colour space for colour images (PNG colour types 2, 3, and
- * 6), or a greyscale colour space for greyscale images (PNG colour types 0
- * and 4)."
- *
- * This checking code ensures the embedded profile (on either read or write)
- * conforms to the specification requirements. Notice that an ICC 'gray'
- * color-space profile contains the information to transform the monochrome
- * data to XYZ or L*a*b (according to which PCS the profile uses) and this
- * should be used in preference to the standard libpng K channel replication
- * into R, G and B channels.
- *
- * Previously it was suggested that an RGB profile on grayscale data could be
- * handled. However it it is clear that using an RGB profile in this context
- * must be an error - there is no specification of what it means. Thus it is
- * almost certainly more correct to ignore the profile.
- */
- temp = png_get_uint_32(profile+16); /* data colour space field */
- switch (temp)
- {
- case 0x52474220: /* 'RGB ' */
- if (!(color_type & PNG_COLOR_MASK_COLOR))
- return png_icc_profile_error(png_ptr, colorspace, name, temp,
- "RGB color space not permitted on grayscale PNG");
- break;
-
- case 0x47524159: /* 'GRAY' */
- if (color_type & PNG_COLOR_MASK_COLOR)
- return png_icc_profile_error(png_ptr, colorspace, name, temp,
- "Gray color space not permitted on RGB PNG");
- break;
-
- default:
- return png_icc_profile_error(png_ptr, colorspace, name, temp,
- "invalid ICC profile color space");
- }
-
- /* It is up to the application to check that the profile class matches the
- * application requirements; the spec provides no guidance, but it's pretty
- * weird if the profile is not scanner ('scnr'), monitor ('mntr'), printer
- * ('prtr') or 'spac' (for generic color spaces). Issue a warning in these
- * cases. Issue an error for device link or abstract profiles - these don't
- * contain the records necessary to transform the color-space to anything
- * other than the target device (and not even that for an abstract profile).
- * Profiles of these classes may not be embedded in images.
- */
- temp = png_get_uint_32(profile+12); /* profile/device class */
- switch (temp)
- {
- case 0x73636E72: /* 'scnr' */
- case 0x6D6E7472: /* 'mntr' */
- case 0x70727472: /* 'prtr' */
- case 0x73706163: /* 'spac' */
- /* All supported */
- break;
-
- case 0x61627374: /* 'abst' */
- /* May not be embedded in an image */
- return png_icc_profile_error(png_ptr, colorspace, name, temp,
- "invalid embedded Abstract ICC profile");
-
- case 0x6C696E6B: /* 'link' */
- /* DeviceLink profiles cannnot be interpreted in a non-device specific
- * fashion, if an app uses the AToB0Tag in the profile the results are
- * undefined unless the result is sent to the intended device,
- * therefore a DeviceLink profile should not be found embedded in a
- * PNG.
- */
- return png_icc_profile_error(png_ptr, colorspace, name, temp,
- "unexpected DeviceLink ICC profile class");
-
- case 0x6E6D636C: /* 'nmcl' */
- /* A NamedColor profile is also device specific, however it doesn't
- * contain an AToB0 tag that is open to misintrepretation. Almost
- * certainly it will fail the tests below.
- */
- (void)png_icc_profile_error(png_ptr, NULL, name, temp,
- "unexpected NamedColor ICC profile class");
- break;
-
- default:
- /* To allow for future enhancements to the profile accept unrecognized
- * profile classes with a warning, these then hit the test below on the
- * tag content to ensure they are backward compatible with one of the
- * understood profiles.
- */
- (void)png_icc_profile_error(png_ptr, NULL, name, temp,
- "unrecognized ICC profile class");
- break;
- }
-
- /* For any profile other than a device link one the PCS must be encoded
- * either in XYZ or Lab.
- */
- temp = png_get_uint_32(profile+20);
- switch (temp)
- {
- case 0x58595A20: /* 'XYZ ' */
- case 0x4C616220: /* 'Lab ' */
- break;
-
- default:
- return png_icc_profile_error(png_ptr, colorspace, name, temp,
- "unexpected ICC PCS encoding");
- }
-
- return 1;
-}
-
-int /* PRIVATE */
-png_icc_check_tag_table(png_const_structrp png_ptr, png_colorspacerp colorspace,
- png_const_charp name, png_uint_32 profile_length,
- png_const_bytep profile /* header plus whole tag table */)
-{
- png_uint_32 tag_count = png_get_uint_32(profile+128);
- png_uint_32 itag;
- png_const_bytep tag = profile+132; /* The first tag */
-
- /* First scan all the tags in the table and add bits to the icc_info value
- * (temporarily in 'tags').
- */
- for (itag=0; itag < tag_count; ++itag, tag += 12)
- {
- png_uint_32 tag_id = png_get_uint_32(tag+0);
- png_uint_32 tag_start = png_get_uint_32(tag+4); /* must be aligned */
- png_uint_32 tag_length = png_get_uint_32(tag+8);/* not padded */
-
- /* The ICC specification does not exclude zero length tags, therefore the
- * start might actually be anywhere if there is no data, but this would be
- * a clear abuse of the intent of the standard so the start is checked for
- * being in range. All defined tag types have an 8 byte header - a 4 byte
- * type signature then 0.
- */
- if ((tag_start & 3) != 0)
- {
- /* CNHP730S.icc shipped with Microsoft Windows 64 violates this, it is
- * only a warning here because libpng does not care about the
- * alignment.
- */
- (void)png_icc_profile_error(png_ptr, NULL, name, tag_id,
- "ICC profile tag start not a multiple of 4");
- }
-
- /* This is a hard error; potentially it can cause read outside the
- * profile.
- */
- if (tag_start > profile_length || tag_length > profile_length - tag_start)
- return png_icc_profile_error(png_ptr, colorspace, name, tag_id,
- "ICC profile tag outside profile");
- }
-
- return 1; /* success, maybe with warnings */
-}
-
-#ifdef PNG_sRGB_SUPPORTED
-/* Information about the known ICC sRGB profiles */
-static const struct
-{
- png_uint_32 adler, crc, length;
- png_uint_32 md5[4];
- png_byte have_md5;
- png_byte is_broken;
- png_uint_16 intent;
-
-# define PNG_MD5(a,b,c,d) { a, b, c, d }, (a!=0)||(b!=0)||(c!=0)||(d!=0)
-# define PNG_ICC_CHECKSUM(adler, crc, md5, intent, broke, date, length, fname)\
- { adler, crc, length, md5, broke, intent },
-
-} png_sRGB_checks[] =
-{
- /* This data comes from contrib/tools/checksum-icc run on downloads of
- * all four ICC sRGB profiles from www.color.org.
- */
- /* adler32, crc32, MD5[4], intent, date, length, file-name */
- PNG_ICC_CHECKSUM(0x0a3fd9f6, 0x3b8772b9,
- PNG_MD5(0x29f83dde, 0xaff255ae, 0x7842fae4, 0xca83390d), 0, 0,
- "2009/03/27 21:36:31", 3048, "sRGB_IEC61966-2-1_black_scaled.icc")
-
- /* ICC sRGB v2 perceptual no black-compensation: */
- PNG_ICC_CHECKSUM(0x4909e5e1, 0x427ebb21,
- PNG_MD5(0xc95bd637, 0xe95d8a3b, 0x0df38f99, 0xc1320389), 1, 0,
- "2009/03/27 21:37:45", 3052, "sRGB_IEC61966-2-1_no_black_scaling.icc")
-
- PNG_ICC_CHECKSUM(0xfd2144a1, 0x306fd8ae,
- PNG_MD5(0xfc663378, 0x37e2886b, 0xfd72e983, 0x8228f1b8), 0, 0,
- "2009/08/10 17:28:01", 60988, "sRGB_v4_ICC_preference_displayclass.icc")
-
- /* ICC sRGB v4 perceptual */
- PNG_ICC_CHECKSUM(0x209c35d2, 0xbbef7812,
- PNG_MD5(0x34562abf, 0x994ccd06, 0x6d2c5721, 0xd0d68c5d), 0, 0,
- "2007/07/25 00:05:37", 60960, "sRGB_v4_ICC_preference.icc")
-
- /* The following profiles have no known MD5 checksum. If there is a match
- * on the (empty) MD5 the other fields are used to attempt a match and
- * a warning is produced. The first two of these profiles have a 'cprt' tag
- * which suggests that they were also made by Hewlett Packard.
- */
- PNG_ICC_CHECKSUM(0xa054d762, 0x5d5129ce,
- PNG_MD5(0x00000000, 0x00000000, 0x00000000, 0x00000000), 1, 0,
- "2004/07/21 18:57:42", 3024, "sRGB_IEC61966-2-1_noBPC.icc")
-
- /* This is a 'mntr' (display) profile with a mediaWhitePointTag that does not
- * match the D50 PCS illuminant in the header (it is in fact the D65 values,
- * so the white point is recorded as the un-adapted value.) The profiles
- * below only differ in one byte - the intent - and are basically the same as
- * the previous profile except for the mediaWhitePointTag error and a missing
- * chromaticAdaptationTag.
- */
- PNG_ICC_CHECKSUM(0xf784f3fb, 0x182ea552,
- PNG_MD5(0x00000000, 0x00000000, 0x00000000, 0x00000000), 0, 1/*broken*/,
- "1998/02/09 06:49:00", 3144, "HP-Microsoft sRGB v2 perceptual")
-
- PNG_ICC_CHECKSUM(0x0398f3fc, 0xf29e526d,
- PNG_MD5(0x00000000, 0x00000000, 0x00000000, 0x00000000), 1, 1/*broken*/,
- "1998/02/09 06:49:00", 3144, "HP-Microsoft sRGB v2 media-relative")
-};
-
-static int
-png_compare_ICC_profile_with_sRGB(png_const_structrp png_ptr,
- png_const_bytep profile, uLong adler)
-{
- /* The quick check is to verify just the MD5 signature and trust the
- * rest of the data. Because the profile has already been verified for
- * correctness this is safe. png_colorspace_set_sRGB will check the 'intent'
- * field too, so if the profile has been edited with an intent not defined
- * by sRGB (but maybe defined by a later ICC specification) the read of
- * the profile will fail at that point.
- */
- png_uint_32 length = 0;
- png_uint_32 intent = 0x10000; /* invalid */
-#if PNG_sRGB_PROFILE_CHECKS > 1
- uLong crc = 0; /* the value for 0 length data */
-#endif
- unsigned int i;
-
- for (i=0; i < (sizeof png_sRGB_checks) / (sizeof png_sRGB_checks[0]); ++i)
- {
- if (png_get_uint_32(profile+84) == png_sRGB_checks[i].md5[0] &&
- png_get_uint_32(profile+88) == png_sRGB_checks[i].md5[1] &&
- png_get_uint_32(profile+92) == png_sRGB_checks[i].md5[2] &&
- png_get_uint_32(profile+96) == png_sRGB_checks[i].md5[3])
- {
- /* This may be one of the old HP profiles without an MD5, in that
- * case we can only use the length and Adler32 (note that these
- * are not used by default if there is an MD5!)
- */
-# if PNG_sRGB_PROFILE_CHECKS == 0
- if (png_sRGB_checks[i].have_md5)
- return 1+png_sRGB_checks[i].is_broken;
-# endif
-
- /* Profile is unsigned or more checks have been configured in. */
- if (length == 0)
- {
- length = png_get_uint_32(profile);
- intent = png_get_uint_32(profile+64);
- }
-
- /* Length *and* intent must match */
- if (length == png_sRGB_checks[i].length &&
- intent == png_sRGB_checks[i].intent)
- {
- /* Now calculate the adler32 if not done already. */
- if (adler == 0)
- {
- adler = adler32(0, NULL, 0);
- adler = adler32(adler, profile, length);
- }
-
- if (adler == png_sRGB_checks[i].adler)
- {
- /* These basic checks suggest that the data has not been
- * modified, but if the check level is more than 1 perform
- * our own crc32 checksum on the data.
- */
-# if PNG_sRGB_PROFILE_CHECKS > 1
- if (crc == 0)
- {
- crc = crc32(0, NULL, 0);
- crc = crc32(crc, profile, length);
- }
-
- /* So this check must pass for the 'return' below to happen.
- */
- if (crc == png_sRGB_checks[i].crc)
-# endif
- {
- if (png_sRGB_checks[i].is_broken)
- {
- /* These profiles are known to have bad data that may cause
- * problems if they are used, therefore attempt to
- * discourage their use, skip the 'have_md5' warning below,
- * which is made irrelevant by this error.
- */
- png_chunk_report(png_ptr, "known incorrect sRGB profile",
- PNG_CHUNK_ERROR);
- }
-
- /* Warn that this being done; this isn't even an error since
- * the profile is perfectly valid, but it would be nice if
- * people used the up-to-date ones.
- */
- else if (!png_sRGB_checks[i].have_md5)
- {
- png_chunk_report(png_ptr,
- "out-of-date sRGB profile with no signature",
- PNG_CHUNK_WARNING);
- }
-
- return 1+png_sRGB_checks[i].is_broken;
- }
- }
- }
-
-# if PNG_sRGB_PROFILE_CHECKS > 0
- /* The signature matched, but the profile had been changed in some
- * way. This is an apparent violation of the ICC terms of use and,
- * anyway, probably indicates a data error or uninformed hacking.
- */
- if (png_sRGB_checks[i].have_md5)
- png_benign_error(png_ptr,
- "copyright violation: edited ICC profile ignored");
-# endif
- }
- }
-
- return 0; /* no match */
-}
-#endif
-
-#ifdef PNG_sRGB_SUPPORTED
-void /* PRIVATE */
-png_icc_set_sRGB(png_const_structrp png_ptr,
- png_colorspacerp colorspace, png_const_bytep profile, uLong adler)
-{
- /* Is this profile one of the known ICC sRGB profiles? If it is, just set
- * the sRGB information.
- */
- if (png_compare_ICC_profile_with_sRGB(png_ptr, profile, adler))
- (void)png_colorspace_set_sRGB(png_ptr, colorspace,
- (int)/*already checked*/png_get_uint_32(profile+64));
-}
-#endif /* PNG_READ_sRGB_SUPPORTED */
-
-int /* PRIVATE */
-png_colorspace_set_ICC(png_const_structrp png_ptr, png_colorspacerp colorspace,
- png_const_charp name, png_uint_32 profile_length, png_const_bytep profile,
- int color_type)
-{
- if (colorspace->flags & PNG_COLORSPACE_INVALID)
- return 0;
-
- if (png_icc_check_length(png_ptr, colorspace, name, profile_length) &&
- png_icc_check_header(png_ptr, colorspace, name, profile_length, profile,
- color_type) &&
- png_icc_check_tag_table(png_ptr, colorspace, name, profile_length,
- profile))
- {
-# ifdef PNG_sRGB_SUPPORTED
- /* If no sRGB support, don't try storing sRGB information */
- png_icc_set_sRGB(png_ptr, colorspace, profile, 0);
-# endif
- return 1;
- }
-
- /* Failure case */
- return 0;
-}
-#endif /* iCCP */
-
-#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
-void /* PRIVATE */
-png_colorspace_set_rgb_coefficients(png_structrp png_ptr)
-{
- /* Set the rgb_to_gray coefficients from the colorspace. */
- if (!png_ptr->rgb_to_gray_coefficients_set &&
- (png_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_ENDPOINTS) != 0)
- {
- /* png_set_background has not been called, get the coefficients from the Y
- * values of the colorspace colorants.
- */
- png_fixed_point r = png_ptr->colorspace.end_points_XYZ.red_Y;
- png_fixed_point g = png_ptr->colorspace.end_points_XYZ.green_Y;
- png_fixed_point b = png_ptr->colorspace.end_points_XYZ.blue_Y;
- png_fixed_point total = r+g+b;
-
- if (total > 0 &&
- r >= 0 && png_muldiv(&r, r, 32768, total) && r >= 0 && r <= 32768 &&
- g >= 0 && png_muldiv(&g, g, 32768, total) && g >= 0 && g <= 32768 &&
- b >= 0 && png_muldiv(&b, b, 32768, total) && b >= 0 && b <= 32768 &&
- r+g+b <= 32769)
- {
- /* We allow 0 coefficients here. r+g+b may be 32769 if two or
- * all of the coefficients were rounded up. Handle this by
- * reducing the *largest* coefficient by 1; this matches the
- * approach used for the default coefficients in pngrtran.c
- */
- int add = 0;
-
- if (r+g+b > 32768)
- add = -1;
- else if (r+g+b < 32768)
- add = 1;
-
- if (add != 0)
- {
- if (g >= r && g >= b)
- g += add;
- else if (r >= g && r >= b)
- r += add;
- else
- b += add;
- }
-
- /* Check for an internal error. */
- if (r+g+b != 32768)
- png_error(png_ptr,
- "internal error handling cHRM coefficients");
-
- else
- {
- png_ptr->rgb_to_gray_red_coeff = (png_uint_16)r;
- png_ptr->rgb_to_gray_green_coeff = (png_uint_16)g;
- }
- }
-
- /* This is a png_error at present even though it could be ignored -
- * it should never happen, but it is important that if it does, the
- * bug is fixed.
- */
- else
- png_error(png_ptr, "internal error handling cHRM->XYZ");
- }
-}
-#endif
-
-#endif /* COLORSPACE */
-
-void /* PRIVATE */
-png_check_IHDR(png_const_structrp png_ptr,
- png_uint_32 width, png_uint_32 height, int bit_depth,
- int color_type, int interlace_type, int compression_type,
- int filter_type)
-{
- int error = 0;
-
- /* Check for width and height valid values */
- if (width == 0)
- {
- png_warning(png_ptr, "Image width is zero in IHDR");
- error = 1;
- }
-
- if (height == 0)
- {
- png_warning(png_ptr, "Image height is zero in IHDR");
- error = 1;
- }
-
-# ifdef PNG_SET_USER_LIMITS_SUPPORTED
- if (width > png_ptr->user_width_max)
-
-# else
- if (width > PNG_USER_WIDTH_MAX)
-# endif
- {
- png_warning(png_ptr, "Image width exceeds user limit in IHDR");
- error = 1;
- }
-
-# ifdef PNG_SET_USER_LIMITS_SUPPORTED
- if (height > png_ptr->user_height_max)
-# else
- if (height > PNG_USER_HEIGHT_MAX)
-# endif
- {
- png_warning(png_ptr, "Image height exceeds user limit in IHDR");
- error = 1;
- }
-
- if (width > PNG_UINT_31_MAX)
- {
- png_warning(png_ptr, "Invalid image width in IHDR");
- error = 1;
- }
-
- if (height > PNG_UINT_31_MAX)
- {
- png_warning(png_ptr, "Invalid image height in IHDR");
- error = 1;
- }
-
- if (width > (PNG_UINT_32_MAX
- >> 3) /* 8-byte RGBA pixels */
- - 48 /* bigrowbuf hack */
- - 1 /* filter byte */
- - 7*8 /* rounding of width to multiple of 8 pixels */
- - 8) /* extra max_pixel_depth pad */
- png_warning(png_ptr, "Width is too large for libpng to process pixels");
-
- /* Check other values */
- if (bit_depth != 1 && bit_depth != 2 && bit_depth != 4 &&
- bit_depth != 8 && bit_depth != 16)
- {
- png_warning(png_ptr, "Invalid bit depth in IHDR");
- error = 1;
- }
-
- if (color_type < 0 || color_type == 1 ||
- color_type == 5 || color_type > 6)
- {
- png_warning(png_ptr, "Invalid color type in IHDR");
- error = 1;
- }
-
- if (((color_type == PNG_COLOR_TYPE_PALETTE) && bit_depth > 8) ||
- ((color_type == PNG_COLOR_TYPE_RGB ||
- color_type == PNG_COLOR_TYPE_GRAY_ALPHA ||
- color_type == PNG_COLOR_TYPE_RGB_ALPHA) && bit_depth < 8))
- {
- png_warning(png_ptr, "Invalid color type/bit depth combination in IHDR");
- error = 1;
- }
-
- if (interlace_type >= PNG_INTERLACE_LAST)
- {
- png_warning(png_ptr, "Unknown interlace method in IHDR");
- error = 1;
- }
-
- if (compression_type != PNG_COMPRESSION_TYPE_BASE)
- {
- png_warning(png_ptr, "Unknown compression method in IHDR");
- error = 1;
- }
-
-# ifdef PNG_MNG_FEATURES_SUPPORTED
- /* Accept filter_method 64 (intrapixel differencing) only if
- * 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and
- * 2. Libpng did not read a PNG signature (this filter_method is only
- * used in PNG datastreams that are embedded in MNG datastreams) and
- * 3. The application called png_permit_mng_features with a mask that
- * included PNG_FLAG_MNG_FILTER_64 and
- * 4. The filter_method is 64 and
- * 5. The color_type is RGB or RGBA
- */
- if ((png_ptr->mode & PNG_HAVE_PNG_SIGNATURE) &&
- png_ptr->mng_features_permitted)
- png_warning(png_ptr, "MNG features are not allowed in a PNG datastream");
-
- if (filter_type != PNG_FILTER_TYPE_BASE)
- {
- if (!((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
- (filter_type == PNG_INTRAPIXEL_DIFFERENCING) &&
- ((png_ptr->mode & PNG_HAVE_PNG_SIGNATURE) == 0) &&
- (color_type == PNG_COLOR_TYPE_RGB ||
- color_type == PNG_COLOR_TYPE_RGB_ALPHA)))
- {
- png_warning(png_ptr, "Unknown filter method in IHDR");
- error = 1;
- }
-
- if (png_ptr->mode & PNG_HAVE_PNG_SIGNATURE)
- {
- png_warning(png_ptr, "Invalid filter method in IHDR");
- error = 1;
- }
- }
-
-# else
- if (filter_type != PNG_FILTER_TYPE_BASE)
- {
- png_warning(png_ptr, "Unknown filter method in IHDR");
- error = 1;
- }
-# endif
-
- if (error == 1)
- png_error(png_ptr, "Invalid IHDR data");
-}
-
-#if defined(PNG_sCAL_SUPPORTED) || defined(PNG_pCAL_SUPPORTED)
-/* ASCII to fp functions */
-/* Check an ASCII formated floating point value, see the more detailed
- * comments in pngpriv.h
- */
-/* The following is used internally to preserve the sticky flags */
-#define png_fp_add(state, flags) ((state) |= (flags))
-#define png_fp_set(state, value) ((state) = (value) | ((state) & PNG_FP_STICKY))
-
-int /* PRIVATE */
-png_check_fp_number(png_const_charp string, png_size_t size, int *statep,
- png_size_tp whereami)
-{
- int state = *statep;
- png_size_t i = *whereami;
-
- while (i < size)
- {
- int type;
- /* First find the type of the next character */
- switch (string[i])
- {
- case 43: type = PNG_FP_SAW_SIGN; break;
- case 45: type = PNG_FP_SAW_SIGN + PNG_FP_NEGATIVE; break;
- case 46: type = PNG_FP_SAW_DOT; break;
- case 48: type = PNG_FP_SAW_DIGIT; break;
- case 49: case 50: case 51: case 52:
- case 53: case 54: case 55: case 56:
- case 57: type = PNG_FP_SAW_DIGIT + PNG_FP_NONZERO; break;
- case 69:
- case 101: type = PNG_FP_SAW_E; break;
- default: goto PNG_FP_End;
- }
-
- /* Now deal with this type according to the current
- * state, the type is arranged to not overlap the
- * bits of the PNG_FP_STATE.
- */
- switch ((state & PNG_FP_STATE) + (type & PNG_FP_SAW_ANY))
- {
- case PNG_FP_INTEGER + PNG_FP_SAW_SIGN:
- if (state & PNG_FP_SAW_ANY)
- goto PNG_FP_End; /* not a part of the number */
-
- png_fp_add(state, type);
- break;
-
- case PNG_FP_INTEGER + PNG_FP_SAW_DOT:
- /* Ok as trailer, ok as lead of fraction. */
- if (state & PNG_FP_SAW_DOT) /* two dots */
- goto PNG_FP_End;
-
- else if (state & PNG_FP_SAW_DIGIT) /* trailing dot? */
- png_fp_add(state, type);
-
- else
- png_fp_set(state, PNG_FP_FRACTION | type);
-
- break;
-
- case PNG_FP_INTEGER + PNG_FP_SAW_DIGIT:
- if (state & PNG_FP_SAW_DOT) /* delayed fraction */
- png_fp_set(state, PNG_FP_FRACTION | PNG_FP_SAW_DOT);
-
- png_fp_add(state, type | PNG_FP_WAS_VALID);
-
- break;
-
- case PNG_FP_INTEGER + PNG_FP_SAW_E:
- if ((state & PNG_FP_SAW_DIGIT) == 0)
- goto PNG_FP_End;
-
- png_fp_set(state, PNG_FP_EXPONENT);
-
- break;
-
- /* case PNG_FP_FRACTION + PNG_FP_SAW_SIGN:
- goto PNG_FP_End; ** no sign in fraction */
-
- /* case PNG_FP_FRACTION + PNG_FP_SAW_DOT:
- goto PNG_FP_End; ** Because SAW_DOT is always set */
-
- case PNG_FP_FRACTION + PNG_FP_SAW_DIGIT:
- png_fp_add(state, type | PNG_FP_WAS_VALID);
- break;
-
- case PNG_FP_FRACTION + PNG_FP_SAW_E:
- /* This is correct because the trailing '.' on an
- * integer is handled above - so we can only get here
- * with the sequence ".E" (with no preceding digits).
- */
- if ((state & PNG_FP_SAW_DIGIT) == 0)
- goto PNG_FP_End;
-
- png_fp_set(state, PNG_FP_EXPONENT);
-
- break;
-
- case PNG_FP_EXPONENT + PNG_FP_SAW_SIGN:
- if (state & PNG_FP_SAW_ANY)
- goto PNG_FP_End; /* not a part of the number */
-
- png_fp_add(state, PNG_FP_SAW_SIGN);
-
- break;
-
- /* case PNG_FP_EXPONENT + PNG_FP_SAW_DOT:
- goto PNG_FP_End; */
-
- case PNG_FP_EXPONENT + PNG_FP_SAW_DIGIT:
- png_fp_add(state, PNG_FP_SAW_DIGIT | PNG_FP_WAS_VALID);
-
- break;
-
- /* case PNG_FP_EXPONEXT + PNG_FP_SAW_E:
- goto PNG_FP_End; */
-
- default: goto PNG_FP_End; /* I.e. break 2 */
- }
-
- /* The character seems ok, continue. */
- ++i;
- }
-
-PNG_FP_End:
- /* Here at the end, update the state and return the correct
- * return code.
- */
- *statep = state;
- *whereami = i;
-
- return (state & PNG_FP_SAW_DIGIT) != 0;
-}
-
-
-/* The same but for a complete string. */
-int
-png_check_fp_string(png_const_charp string, png_size_t size)
-{
- int state=0;
- png_size_t char_index=0;
-
- if (png_check_fp_number(string, size, &state, &char_index) &&
- (char_index == size || string[char_index] == 0))
- return state /* must be non-zero - see above */;
-
- return 0; /* i.e. fail */
-}
-#endif /* pCAL or sCAL */
-
-#ifdef PNG_sCAL_SUPPORTED
-# ifdef PNG_FLOATING_POINT_SUPPORTED
-/* Utility used below - a simple accurate power of ten from an integral
- * exponent.
- */
-static double
-png_pow10(int power)
-{
- int recip = 0;
- double d = 1;
-
- /* Handle negative exponent with a reciprocal at the end because
- * 10 is exact whereas .1 is inexact in base 2
- */
- if (power < 0)
- {
- if (power < DBL_MIN_10_EXP) return 0;
- recip = 1, power = -power;
- }
-
- if (power > 0)
- {
- /* Decompose power bitwise. */
- double mult = 10;
- do
- {
- if (power & 1) d *= mult;
- mult *= mult;
- power >>= 1;
- }
- while (power > 0);
-
- if (recip) d = 1/d;
- }
- /* else power is 0 and d is 1 */
-
- return d;
-}
-
-/* Function to format a floating point value in ASCII with a given
- * precision.
- */
-void /* PRIVATE */
-png_ascii_from_fp(png_const_structrp png_ptr, png_charp ascii, png_size_t size,
- double fp, unsigned int precision)
-{
- /* We use standard functions from math.h, but not printf because
- * that would require stdio. The caller must supply a buffer of
- * sufficient size or we will png_error. The tests on size and
- * the space in ascii[] consumed are indicated below.
- */
- if (precision < 1)
- precision = DBL_DIG;
-
- /* Enforce the limit of the implementation precision too. */
- if (precision > DBL_DIG+1)
- precision = DBL_DIG+1;
-
- /* Basic sanity checks */
- if (size >= precision+5) /* See the requirements below. */
- {
- if (fp < 0)
- {
- fp = -fp;
- *ascii++ = 45; /* '-' PLUS 1 TOTAL 1 */
- --size;
- }
-
- if (fp >= DBL_MIN && fp <= DBL_MAX)
- {
- int exp_b10; /* A base 10 exponent */
- double base; /* 10^exp_b10 */
-
- /* First extract a base 10 exponent of the number,
- * the calculation below rounds down when converting
- * from base 2 to base 10 (multiply by log10(2) -
- * 0.3010, but 77/256 is 0.3008, so exp_b10 needs to
- * be increased. Note that the arithmetic shift
- * performs a floor() unlike C arithmetic - using a
- * C multiply would break the following for negative
- * exponents.
- */
- (void)frexp(fp, &exp_b10); /* exponent to base 2 */
-
- exp_b10 = (exp_b10 * 77) >> 8; /* <= exponent to base 10 */
-
- /* Avoid underflow here. */
- base = png_pow10(exp_b10); /* May underflow */
-
- while (base < DBL_MIN || base < fp)
- {
- /* And this may overflow. */
- double test = png_pow10(exp_b10+1);
-
- if (test <= DBL_MAX)
- ++exp_b10, base = test;
-
- else
- break;
- }
-
- /* Normalize fp and correct exp_b10, after this fp is in the
- * range [.1,1) and exp_b10 is both the exponent and the digit
- * *before* which the decimal point should be inserted
- * (starting with 0 for the first digit). Note that this
- * works even if 10^exp_b10 is out of range because of the
- * test on DBL_MAX above.
- */
- fp /= base;
- while (fp >= 1) fp /= 10, ++exp_b10;
-
- /* Because of the code above fp may, at this point, be
- * less than .1, this is ok because the code below can
- * handle the leading zeros this generates, so no attempt
- * is made to correct that here.
- */
-
- {
- int czero, clead, cdigits;
- char exponent[10];
-
- /* Allow up to two leading zeros - this will not lengthen
- * the number compared to using E-n.
- */
- if (exp_b10 < 0 && exp_b10 > -3) /* PLUS 3 TOTAL 4 */
- {
- czero = -exp_b10; /* PLUS 2 digits: TOTAL 3 */
- exp_b10 = 0; /* Dot added below before first output. */
- }
- else
- czero = 0; /* No zeros to add */
-
- /* Generate the digit list, stripping trailing zeros and
- * inserting a '.' before a digit if the exponent is 0.
- */
- clead = czero; /* Count of leading zeros */
- cdigits = 0; /* Count of digits in list. */
-
- do
- {
- double d;
-
- fp *= 10;
- /* Use modf here, not floor and subtract, so that
- * the separation is done in one step. At the end
- * of the loop don't break the number into parts so
- * that the final digit is rounded.
- */
- if (cdigits+czero-clead+1 < (int)precision)
- fp = modf(fp, &d);
-
- else
- {
- d = floor(fp + .5);
-
- if (d > 9)
- {
- /* Rounding up to 10, handle that here. */
- if (czero > 0)
- {
- --czero, d = 1;
- if (cdigits == 0) --clead;
- }
- else
- {
- while (cdigits > 0 && d > 9)
- {
- int ch = *--ascii;
-
- if (exp_b10 != (-1))
- ++exp_b10;
-
- else if (ch == 46)
- {
- ch = *--ascii, ++size;
- /* Advance exp_b10 to '1', so that the
- * decimal point happens after the
- * previous digit.
- */
- exp_b10 = 1;
- }
-
- --cdigits;
- d = ch - 47; /* I.e. 1+(ch-48) */
- }
-
- /* Did we reach the beginning? If so adjust the
- * exponent but take into account the leading
- * decimal point.
- */
- if (d > 9) /* cdigits == 0 */
- {
- if (exp_b10 == (-1))
- {
- /* Leading decimal point (plus zeros?), if
- * we lose the decimal point here it must
- * be reentered below.
- */
- int ch = *--ascii;
-
- if (ch == 46)
- ++size, exp_b10 = 1;
-
- /* Else lost a leading zero, so 'exp_b10' is
- * still ok at (-1)
- */
- }
- else
- ++exp_b10;
-
- /* In all cases we output a '1' */
- d = 1;
- }
- }
- }
- fp = 0; /* Guarantees termination below. */
- }
-
- if (d == 0)
- {
- ++czero;
- if (cdigits == 0) ++clead;
- }
- else
- {
- /* Included embedded zeros in the digit count. */
- cdigits += czero - clead;
- clead = 0;
-
- while (czero > 0)
- {
- /* exp_b10 == (-1) means we just output the decimal
- * place - after the DP don't adjust 'exp_b10' any
- * more!
- */
- if (exp_b10 != (-1))
- {
- if (exp_b10 == 0) *ascii++ = 46, --size;
- /* PLUS 1: TOTAL 4 */
- --exp_b10;
- }
- *ascii++ = 48, --czero;
- }
-
- if (exp_b10 != (-1))
- {
- if (exp_b10 == 0) *ascii++ = 46, --size; /* counted
- above */
- --exp_b10;
- }
- *ascii++ = (char)(48 + (int)d), ++cdigits;
- }
- }
- while (cdigits+czero-clead < (int)precision && fp > DBL_MIN);
-
- /* The total output count (max) is now 4+precision */
-
- /* Check for an exponent, if we don't need one we are
- * done and just need to terminate the string. At
- * this point exp_b10==(-1) is effectively if flag - it got
- * to '-1' because of the decrement after outputing
- * the decimal point above (the exponent required is
- * *not* -1!)
- */
- if (exp_b10 >= (-1) && exp_b10 <= 2)
- {
- /* The following only happens if we didn't output the
- * leading zeros above for negative exponent, so this
- * doest add to the digit requirement. Note that the
- * two zeros here can only be output if the two leading
- * zeros were *not* output, so this doesn't increase
- * the output count.
- */
- while (--exp_b10 >= 0) *ascii++ = 48;
-
- *ascii = 0;
-
- /* Total buffer requirement (including the '\0') is
- * 5+precision - see check at the start.
- */
- return;
- }
-
- /* Here if an exponent is required, adjust size for
- * the digits we output but did not count. The total
- * digit output here so far is at most 1+precision - no
- * decimal point and no leading or trailing zeros have
- * been output.
- */
- size -= cdigits;
-
- *ascii++ = 69, --size; /* 'E': PLUS 1 TOTAL 2+precision */
-
- /* The following use of an unsigned temporary avoids ambiguities in
- * the signed arithmetic on exp_b10 and permits GCC at least to do
- * better optimization.
- */
- {
- unsigned int uexp_b10;
-
- if (exp_b10 < 0)
- {
- *ascii++ = 45, --size; /* '-': PLUS 1 TOTAL 3+precision */
- uexp_b10 = -exp_b10;
- }
-
- else
- uexp_b10 = exp_b10;
-
- cdigits = 0;
-
- while (uexp_b10 > 0)
- {
- exponent[cdigits++] = (char)(48 + uexp_b10 % 10);
- uexp_b10 /= 10;
- }
- }
-
- /* Need another size check here for the exponent digits, so
- * this need not be considered above.
- */
- if ((int)size > cdigits)
- {
- while (cdigits > 0) *ascii++ = exponent[--cdigits];
-
- *ascii = 0;
-
- return;
- }
- }
- }
- else if (!(fp >= DBL_MIN))
- {
- *ascii++ = 48; /* '0' */
- *ascii = 0;
- return;
- }
- else
- {
- *ascii++ = 105; /* 'i' */
- *ascii++ = 110; /* 'n' */
- *ascii++ = 102; /* 'f' */
- *ascii = 0;
- return;
- }
- }
-
- /* Here on buffer too small. */
- png_error(png_ptr, "ASCII conversion buffer too small");
-}
-
-# endif /* FLOATING_POINT */
-
-# ifdef PNG_FIXED_POINT_SUPPORTED
-/* Function to format a fixed point value in ASCII.
- */
-void /* PRIVATE */
-png_ascii_from_fixed(png_const_structrp png_ptr, png_charp ascii,
- png_size_t size, png_fixed_point fp)
-{
- /* Require space for 10 decimal digits, a decimal point, a minus sign and a
- * trailing \0, 13 characters:
- */
- if (size > 12)
- {
- png_uint_32 num;
-
- /* Avoid overflow here on the minimum integer. */
- if (fp < 0)
- *ascii++ = 45, --size, num = -fp;
- else
- num = fp;
-
- if (num <= 0x80000000) /* else overflowed */
- {
- unsigned int ndigits = 0, first = 16 /* flag value */;
- char digits[10];
-
- while (num)
- {
- /* Split the low digit off num: */
- unsigned int tmp = num/10;
- num -= tmp*10;
- digits[ndigits++] = (char)(48 + num);
- /* Record the first non-zero digit, note that this is a number
- * starting at 1, it's not actually the array index.
- */
- if (first == 16 && num > 0)
- first = ndigits;
- num = tmp;
- }
-
- if (ndigits > 0)
- {
- while (ndigits > 5) *ascii++ = digits[--ndigits];
- /* The remaining digits are fractional digits, ndigits is '5' or
- * smaller at this point. It is certainly not zero. Check for a
- * non-zero fractional digit:
- */
- if (first <= 5)
- {
- unsigned int i;
- *ascii++ = 46; /* decimal point */
- /* ndigits may be <5 for small numbers, output leading zeros
- * then ndigits digits to first:
- */
- i = 5;
- while (ndigits < i) *ascii++ = 48, --i;
- while (ndigits >= first) *ascii++ = digits[--ndigits];
- /* Don't output the trailing zeros! */
- }
- }
- else
- *ascii++ = 48;
-
- /* And null terminate the string: */
- *ascii = 0;
- return;
- }
- }
-
- /* Here on buffer too small. */
- png_error(png_ptr, "ASCII conversion buffer too small");
-}
-# endif /* FIXED_POINT */
-#endif /* READ_SCAL */
-
-#if defined(PNG_FLOATING_POINT_SUPPORTED) && \
- !defined(PNG_FIXED_POINT_MACRO_SUPPORTED) && \
- (defined(PNG_gAMA_SUPPORTED) || defined(PNG_cHRM_SUPPORTED) || \
- defined(PNG_sCAL_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) || \
- defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)) || \
- (defined(PNG_sCAL_SUPPORTED) && \
- defined(PNG_FLOATING_ARITHMETIC_SUPPORTED))
-png_fixed_point
-png_fixed(png_const_structrp png_ptr, double fp, png_const_charp text)
-{
- double r = floor(100000 * fp + .5);
-
- if (r > 2147483647. || r < -2147483648.)
- png_fixed_error(png_ptr, text);
-
- return (png_fixed_point)r;
-}
-#endif
-
-#if defined(PNG_READ_GAMMA_SUPPORTED) || \
- defined(PNG_INCH_CONVERSIONS_SUPPORTED) || defined(PNG_READ_pHYs_SUPPORTED)
-/* muldiv functions */
-/* This API takes signed arguments and rounds the result to the nearest
- * integer (or, for a fixed point number - the standard argument - to
- * the nearest .00001). Overflow and divide by zero are signalled in
- * the result, a boolean - true on success, false on overflow.
- */
-int
-png_muldiv(png_fixed_point_p res, png_fixed_point a, png_int_32 times,
- png_int_32 divisor)
-{
- /* Return a * times / divisor, rounded. */
- if (divisor != 0)
- {
- if (a == 0 || times == 0)
- {
- *res = 0;
- return 1;
- }
- else
- {
-#ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED
- double r = a;
- r *= times;
- r /= divisor;
- r = floor(r+.5);
-
- /* A png_fixed_point is a 32-bit integer. */
- if (r <= 2147483647. && r >= -2147483648.)
- {
- *res = (png_fixed_point)r;
- return 1;
- }
-#else
- int negative = 0;
- png_uint_32 A, T, D;
- png_uint_32 s16, s32, s00;
-
- if (a < 0)
- negative = 1, A = -a;
- else
- A = a;
-
- if (times < 0)
- negative = !negative, T = -times;
- else
- T = times;
-
- if (divisor < 0)
- negative = !negative, D = -divisor;
- else
- D = divisor;
-
- /* Following can't overflow because the arguments only
- * have 31 bits each, however the result may be 32 bits.
- */
- s16 = (A >> 16) * (T & 0xffff) +
- (A & 0xffff) * (T >> 16);
- /* Can't overflow because the a*times bit is only 30
- * bits at most.
- */
- s32 = (A >> 16) * (T >> 16) + (s16 >> 16);
- s00 = (A & 0xffff) * (T & 0xffff);
-
- s16 = (s16 & 0xffff) << 16;
- s00 += s16;
-
- if (s00 < s16)
- ++s32; /* carry */
-
- if (s32 < D) /* else overflow */
- {
- /* s32.s00 is now the 64-bit product, do a standard
- * division, we know that s32 < D, so the maximum
- * required shift is 31.
- */
- int bitshift = 32;
- png_fixed_point result = 0; /* NOTE: signed */
-
- while (--bitshift >= 0)
- {
- png_uint_32 d32, d00;
-
- if (bitshift > 0)
- d32 = D >> (32-bitshift), d00 = D << bitshift;
-
- else
- d32 = 0, d00 = D;
-
- if (s32 > d32)
- {
- if (s00 < d00) --s32; /* carry */
- s32 -= d32, s00 -= d00, result += 1<<bitshift;
- }
-
- else
- if (s32 == d32 && s00 >= d00)
- s32 = 0, s00 -= d00, result += 1<<bitshift;
- }
-
- /* Handle the rounding. */
- if (s00 >= (D >> 1))
- ++result;
-
- if (negative)
- result = -result;
-
- /* Check for overflow. */
- if ((negative && result <= 0) || (!negative && result >= 0))
- {
- *res = result;
- return 1;
- }
- }
-#endif
- }
- }
-
- return 0;
-}
-#endif /* READ_GAMMA || INCH_CONVERSIONS */
-
-#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_INCH_CONVERSIONS_SUPPORTED)
-/* The following is for when the caller doesn't much care about the
- * result.
- */
-png_fixed_point
-png_muldiv_warn(png_const_structrp png_ptr, png_fixed_point a, png_int_32 times,
- png_int_32 divisor)
-{
- png_fixed_point result;
-
- if (png_muldiv(&result, a, times, divisor))
- return result;
-
- png_warning(png_ptr, "fixed point overflow ignored");
- return 0;
-}
-#endif
-
-#ifdef PNG_GAMMA_SUPPORTED /* more fixed point functions for gamma */
-/* Calculate a reciprocal, return 0 on div-by-zero or overflow. */
-png_fixed_point
-png_reciprocal(png_fixed_point a)
-{
-#ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED
- double r = floor(1E10/a+.5);
-
- if (r <= 2147483647. && r >= -2147483648.)
- return (png_fixed_point)r;
-#else
- png_fixed_point res;
-
- if (png_muldiv(&res, 100000, 100000, a))
- return res;
-#endif
-
- return 0; /* error/overflow */
-}
-
-/* This is the shared test on whether a gamma value is 'significant' - whether
- * it is worth doing gamma correction.
- */
-int /* PRIVATE */
-png_gamma_significant(png_fixed_point gamma_val)
-{
- return gamma_val < PNG_FP_1 - PNG_GAMMA_THRESHOLD_FIXED ||
- gamma_val > PNG_FP_1 + PNG_GAMMA_THRESHOLD_FIXED;
-}
-#endif
-
-#ifdef PNG_READ_GAMMA_SUPPORTED
-/* A local convenience routine. */
-static png_fixed_point
-png_product2(png_fixed_point a, png_fixed_point b)
-{
- /* The required result is 1/a * 1/b; the following preserves accuracy. */
-#ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED
- double r = a * 1E-5;
- r *= b;
- r = floor(r+.5);
-
- if (r <= 2147483647. && r >= -2147483648.)
- return (png_fixed_point)r;
-#else
- png_fixed_point res;
-
- if (png_muldiv(&res, a, b, 100000))
- return res;
-#endif
-
- return 0; /* overflow */
-}
-
-/* The inverse of the above. */
-png_fixed_point
-png_reciprocal2(png_fixed_point a, png_fixed_point b)
-{
- /* The required result is 1/a * 1/b; the following preserves accuracy. */
-#ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED
- double r = 1E15/a;
- r /= b;
- r = floor(r+.5);
-
- if (r <= 2147483647. && r >= -2147483648.)
- return (png_fixed_point)r;
-#else
- /* This may overflow because the range of png_fixed_point isn't symmetric,
- * but this API is only used for the product of file and screen gamma so it
- * doesn't matter that the smallest number it can produce is 1/21474, not
- * 1/100000
- */
- png_fixed_point res = png_product2(a, b);
-
- if (res != 0)
- return png_reciprocal(res);
-#endif
-
- return 0; /* overflow */
-}
-#endif /* READ_GAMMA */
-
-#ifdef PNG_READ_GAMMA_SUPPORTED /* gamma table code */
-#ifndef PNG_FLOATING_ARITHMETIC_SUPPORTED
-/* Fixed point gamma.
- *
- * The code to calculate the tables used below can be found in the shell script
- * contrib/tools/intgamma.sh
- *
- * To calculate gamma this code implements fast log() and exp() calls using only
- * fixed point arithmetic. This code has sufficient precision for either 8-bit
- * or 16-bit sample values.
- *
- * The tables used here were calculated using simple 'bc' programs, but C double
- * precision floating point arithmetic would work fine.
- *
- * 8-bit log table
- * This is a table of -log(value/255)/log(2) for 'value' in the range 128 to
- * 255, so it's the base 2 logarithm of a normalized 8-bit floating point
- * mantissa. The numbers are 32-bit fractions.
- */
-static const png_uint_32
-png_8bit_l2[128] =
-{
- 4270715492U, 4222494797U, 4174646467U, 4127164793U, 4080044201U, 4033279239U,
- 3986864580U, 3940795015U, 3895065449U, 3849670902U, 3804606499U, 3759867474U,
- 3715449162U, 3671346997U, 3627556511U, 3584073329U, 3540893168U, 3498011834U,
- 3455425220U, 3413129301U, 3371120137U, 3329393864U, 3287946700U, 3246774933U,
- 3205874930U, 3165243125U, 3124876025U, 3084770202U, 3044922296U, 3005329011U,
- 2965987113U, 2926893432U, 2888044853U, 2849438323U, 2811070844U, 2772939474U,
- 2735041326U, 2697373562U, 2659933400U, 2622718104U, 2585724991U, 2548951424U,
- 2512394810U, 2476052606U, 2439922311U, 2404001468U, 2368287663U, 2332778523U,
- 2297471715U, 2262364947U, 2227455964U, 2192742551U, 2158222529U, 2123893754U,
- 2089754119U, 2055801552U, 2022034013U, 1988449497U, 1955046031U, 1921821672U,
- 1888774511U, 1855902668U, 1823204291U, 1790677560U, 1758320682U, 1726131893U,
- 1694109454U, 1662251657U, 1630556815U, 1599023271U, 1567649391U, 1536433567U,
- 1505374214U, 1474469770U, 1443718700U, 1413119487U, 1382670639U, 1352370686U,
- 1322218179U, 1292211689U, 1262349810U, 1232631153U, 1203054352U, 1173618059U,
- 1144320946U, 1115161701U, 1086139034U, 1057251672U, 1028498358U, 999877854U,
- 971388940U, 943030410U, 914801076U, 886699767U, 858725327U, 830876614U,
- 803152505U, 775551890U, 748073672U, 720716771U, 693480120U, 666362667U,
- 639363374U, 612481215U, 585715177U, 559064263U, 532527486U, 506103872U,
- 479792461U, 453592303U, 427502463U, 401522014U, 375650043U, 349885648U,
- 324227938U, 298676034U, 273229066U, 247886176U, 222646516U, 197509248U,
- 172473545U, 147538590U, 122703574U, 97967701U, 73330182U, 48790236U,
- 24347096U, 0U
-
-#if 0
- /* The following are the values for 16-bit tables - these work fine for the
- * 8-bit conversions but produce very slightly larger errors in the 16-bit
- * log (about 1.2 as opposed to 0.7 absolute error in the final value). To
- * use these all the shifts below must be adjusted appropriately.
- */
- 65166, 64430, 63700, 62976, 62257, 61543, 60835, 60132, 59434, 58741, 58054,
- 57371, 56693, 56020, 55352, 54689, 54030, 53375, 52726, 52080, 51439, 50803,
- 50170, 49542, 48918, 48298, 47682, 47070, 46462, 45858, 45257, 44661, 44068,
- 43479, 42894, 42312, 41733, 41159, 40587, 40020, 39455, 38894, 38336, 37782,
- 37230, 36682, 36137, 35595, 35057, 34521, 33988, 33459, 32932, 32408, 31887,
- 31369, 30854, 30341, 29832, 29325, 28820, 28319, 27820, 27324, 26830, 26339,
- 25850, 25364, 24880, 24399, 23920, 23444, 22970, 22499, 22029, 21562, 21098,
- 20636, 20175, 19718, 19262, 18808, 18357, 17908, 17461, 17016, 16573, 16132,
- 15694, 15257, 14822, 14390, 13959, 13530, 13103, 12678, 12255, 11834, 11415,
- 10997, 10582, 10168, 9756, 9346, 8937, 8531, 8126, 7723, 7321, 6921, 6523,
- 6127, 5732, 5339, 4947, 4557, 4169, 3782, 3397, 3014, 2632, 2251, 1872, 1495,
- 1119, 744, 372
-#endif
-};
-
-static png_int_32
-png_log8bit(unsigned int x)
-{
- unsigned int lg2 = 0;
- /* Each time 'x' is multiplied by 2, 1 must be subtracted off the final log,
- * because the log is actually negate that means adding 1. The final
- * returned value thus has the range 0 (for 255 input) to 7.994 (for 1
- * input), return -1 for the overflow (log 0) case, - so the result is
- * always at most 19 bits.
- */
- if ((x &= 0xff) == 0)
- return -1;
-
- if ((x & 0xf0) == 0)
- lg2 = 4, x <<= 4;
-
- if ((x & 0xc0) == 0)
- lg2 += 2, x <<= 2;
-
- if ((x & 0x80) == 0)
- lg2 += 1, x <<= 1;
-
- /* result is at most 19 bits, so this cast is safe: */
- return (png_int_32)((lg2 << 16) + ((png_8bit_l2[x-128]+32768)>>16));
-}
-
-/* The above gives exact (to 16 binary places) log2 values for 8-bit images,
- * for 16-bit images we use the most significant 8 bits of the 16-bit value to
- * get an approximation then multiply the approximation by a correction factor
- * determined by the remaining up to 8 bits. This requires an additional step
- * in the 16-bit case.
- *
- * We want log2(value/65535), we have log2(v'/255), where:
- *
- * value = v' * 256 + v''
- * = v' * f
- *
- * So f is value/v', which is equal to (256+v''/v') since v' is in the range 128
- * to 255 and v'' is in the range 0 to 255 f will be in the range 256 to less
- * than 258. The final factor also needs to correct for the fact that our 8-bit
- * value is scaled by 255, whereas the 16-bit values must be scaled by 65535.
- *
- * This gives a final formula using a calculated value 'x' which is value/v' and
- * scaling by 65536 to match the above table:
- *
- * log2(x/257) * 65536
- *
- * Since these numbers are so close to '1' we can use simple linear
- * interpolation between the two end values 256/257 (result -368.61) and 258/257
- * (result 367.179). The values used below are scaled by a further 64 to give
- * 16-bit precision in the interpolation:
- *
- * Start (256): -23591
- * Zero (257): 0
- * End (258): 23499
- */
-static png_int_32
-png_log16bit(png_uint_32 x)
-{
- unsigned int lg2 = 0;
-
- /* As above, but now the input has 16 bits. */
- if ((x &= 0xffff) == 0)
- return -1;
-
- if ((x & 0xff00) == 0)
- lg2 = 8, x <<= 8;
-
- if ((x & 0xf000) == 0)
- lg2 += 4, x <<= 4;
-
- if ((x & 0xc000) == 0)
- lg2 += 2, x <<= 2;
-
- if ((x & 0x8000) == 0)
- lg2 += 1, x <<= 1;
-
- /* Calculate the base logarithm from the top 8 bits as a 28-bit fractional
- * value.
- */
- lg2 <<= 28;
- lg2 += (png_8bit_l2[(x>>8)-128]+8) >> 4;
-
- /* Now we need to interpolate the factor, this requires a division by the top
- * 8 bits. Do this with maximum precision.
- */
- x = ((x << 16) + (x >> 9)) / (x >> 8);
-
- /* Since we divided by the top 8 bits of 'x' there will be a '1' at 1<<24,
- * the value at 1<<16 (ignoring this) will be 0 or 1; this gives us exactly
- * 16 bits to interpolate to get the low bits of the result. Round the
- * answer. Note that the end point values are scaled by 64 to retain overall
- * precision and that 'lg2' is current scaled by an extra 12 bits, so adjust
- * the overall scaling by 6-12. Round at every step.
- */
- x -= 1U << 24;
-
- if (x <= 65536U) /* <= '257' */
- lg2 += ((23591U * (65536U-x)) + (1U << (16+6-12-1))) >> (16+6-12);
-
- else
- lg2 -= ((23499U * (x-65536U)) + (1U << (16+6-12-1))) >> (16+6-12);
-
- /* Safe, because the result can't have more than 20 bits: */
- return (png_int_32)((lg2 + 2048) >> 12);
-}
-
-/* The 'exp()' case must invert the above, taking a 20-bit fixed point
- * logarithmic value and returning a 16 or 8-bit number as appropriate. In
- * each case only the low 16 bits are relevant - the fraction - since the
- * integer bits (the top 4) simply determine a shift.
- *
- * The worst case is the 16-bit distinction between 65535 and 65534, this
- * requires perhaps spurious accuracty in the decoding of the logarithm to
- * distinguish log2(65535/65534.5) - 10^-5 or 17 bits. There is little chance
- * of getting this accuracy in practice.
- *
- * To deal with this the following exp() function works out the exponent of the
- * frational part of the logarithm by using an accurate 32-bit value from the
- * top four fractional bits then multiplying in the remaining bits.
- */
-static const png_uint_32
-png_32bit_exp[16] =
-{
- /* NOTE: the first entry is deliberately set to the maximum 32-bit value. */
- 4294967295U, 4112874773U, 3938502376U, 3771522796U, 3611622603U, 3458501653U,
- 3311872529U, 3171459999U, 3037000500U, 2908241642U, 2784941738U, 2666869345U,
- 2553802834U, 2445529972U, 2341847524U, 2242560872U
-};
-
-/* Adjustment table; provided to explain the numbers in the code below. */
-#if 0
-for (i=11;i>=0;--i){ print i, " ", (1 - e(-(2^i)/65536*l(2))) * 2^(32-i), "\n"}
- 11 44937.64284865548751208448
- 10 45180.98734845585101160448
- 9 45303.31936980687359311872
- 8 45364.65110595323018870784
- 7 45395.35850361789624614912
- 6 45410.72259715102037508096
- 5 45418.40724413220722311168
- 4 45422.25021786898173001728
- 3 45424.17186732298419044352
- 2 45425.13273269940811464704
- 1 45425.61317555035558641664
- 0 45425.85339951654943850496
-#endif
-
-static png_uint_32
-png_exp(png_fixed_point x)
-{
- if (x > 0 && x <= 0xfffff) /* Else overflow or zero (underflow) */
- {
- /* Obtain a 4-bit approximation */
- png_uint_32 e = png_32bit_exp[(x >> 12) & 0xf];
-
- /* Incorporate the low 12 bits - these decrease the returned value by
- * multiplying by a number less than 1 if the bit is set. The multiplier
- * is determined by the above table and the shift. Notice that the values
- * converge on 45426 and this is used to allow linear interpolation of the
- * low bits.
- */
- if (x & 0x800)
- e -= (((e >> 16) * 44938U) + 16U) >> 5;
-
- if (x & 0x400)
- e -= (((e >> 16) * 45181U) + 32U) >> 6;
-
- if (x & 0x200)
- e -= (((e >> 16) * 45303U) + 64U) >> 7;
-
- if (x & 0x100)
- e -= (((e >> 16) * 45365U) + 128U) >> 8;
-
- if (x & 0x080)
- e -= (((e >> 16) * 45395U) + 256U) >> 9;
-
- if (x & 0x040)
- e -= (((e >> 16) * 45410U) + 512U) >> 10;
-
- /* And handle the low 6 bits in a single block. */
- e -= (((e >> 16) * 355U * (x & 0x3fU)) + 256U) >> 9;
-
- /* Handle the upper bits of x. */
- e >>= x >> 16;
- return e;
- }
-
- /* Check for overflow */
- if (x <= 0)
- return png_32bit_exp[0];
-
- /* Else underflow */
- return 0;
-}
-
-static png_byte
-png_exp8bit(png_fixed_point lg2)
-{
- /* Get a 32-bit value: */
- png_uint_32 x = png_exp(lg2);
-
- /* Convert the 32-bit value to 0..255 by multiplying by 256-1, note that the
- * second, rounding, step can't overflow because of the first, subtraction,
- * step.
- */
- x -= x >> 8;
- return (png_byte)((x + 0x7fffffU) >> 24);
-}
-
-static png_uint_16
-png_exp16bit(png_fixed_point lg2)
-{
- /* Get a 32-bit value: */
- png_uint_32 x = png_exp(lg2);
-
- /* Convert the 32-bit value to 0..65535 by multiplying by 65536-1: */
- x -= x >> 16;
- return (png_uint_16)((x + 32767U) >> 16);
-}
-#endif /* FLOATING_ARITHMETIC */
-
-png_byte
-png_gamma_8bit_correct(unsigned int value, png_fixed_point gamma_val)
-{
- if (value > 0 && value < 255)
- {
-# ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED
- double r = floor(255*pow(value/255.,gamma_val*.00001)+.5);
- return (png_byte)r;
-# else
- png_int_32 lg2 = png_log8bit(value);
- png_fixed_point res;
-
- if (png_muldiv(&res, gamma_val, lg2, PNG_FP_1))
- return png_exp8bit(res);
-
- /* Overflow. */
- value = 0;
-# endif
- }
-
- return (png_byte)value;
-}
-
-png_uint_16
-png_gamma_16bit_correct(unsigned int value, png_fixed_point gamma_val)
-{
- if (value > 0 && value < 65535)
- {
-# ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED
- double r = floor(65535*pow(value/65535.,gamma_val*.00001)+.5);
- return (png_uint_16)r;
-# else
- png_int_32 lg2 = png_log16bit(value);
- png_fixed_point res;
-
- if (png_muldiv(&res, gamma_val, lg2, PNG_FP_1))
- return png_exp16bit(res);
-
- /* Overflow. */
- value = 0;
-# endif
- }
-
- return (png_uint_16)value;
-}
-
-/* This does the right thing based on the bit_depth field of the
- * png_struct, interpreting values as 8-bit or 16-bit. While the result
- * is nominally a 16-bit value if bit depth is 8 then the result is
- * 8-bit (as are the arguments.)
- */
-png_uint_16 /* PRIVATE */
-png_gamma_correct(png_structrp png_ptr, unsigned int value,
- png_fixed_point gamma_val)
-{
- if (png_ptr->bit_depth == 8)
- return png_gamma_8bit_correct(value, gamma_val);
-
- else
- return png_gamma_16bit_correct(value, gamma_val);
-}
-
-/* Internal function to build a single 16-bit table - the table consists of
- * 'num' 256 entry subtables, where 'num' is determined by 'shift' - the amount
- * to shift the input values right (or 16-number_of_signifiant_bits).
- *
- * The caller is responsible for ensuring that the table gets cleaned up on
- * png_error (i.e. if one of the mallocs below fails) - i.e. the *table argument
- * should be somewhere that will be cleaned.
- */
-static void
-png_build_16bit_table(png_structrp png_ptr, png_uint_16pp *ptable,
- PNG_CONST unsigned int shift, PNG_CONST png_fixed_point gamma_val)
-{
- /* Various values derived from 'shift': */
- PNG_CONST unsigned int num = 1U << (8U - shift);
- PNG_CONST unsigned int max = (1U << (16U - shift))-1U;
- PNG_CONST unsigned int max_by_2 = 1U << (15U-shift);
- unsigned int i;
-
- png_uint_16pp table = *ptable =
- (png_uint_16pp)png_calloc(png_ptr, num * (sizeof (png_uint_16p)));
-
- for (i = 0; i < num; i++)
- {
- png_uint_16p sub_table = table[i] =
- (png_uint_16p)png_malloc(png_ptr, 256 * (sizeof (png_uint_16)));
-
- /* The 'threshold' test is repeated here because it can arise for one of
- * the 16-bit tables even if the others don't hit it.
- */
- if (png_gamma_significant(gamma_val))
- {
- /* The old code would overflow at the end and this would cause the
- * 'pow' function to return a result >1, resulting in an
- * arithmetic error. This code follows the spec exactly; ig is
- * the recovered input sample, it always has 8-16 bits.
- *
- * We want input * 65535/max, rounded, the arithmetic fits in 32
- * bits (unsigned) so long as max <= 32767.
- */
- unsigned int j;
- for (j = 0; j < 256; j++)
- {
- png_uint_32 ig = (j << (8-shift)) + i;
-# ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED
- /* Inline the 'max' scaling operation: */
- double d = floor(65535*pow(ig/(double)max, gamma_val*.00001)+.5);
- sub_table[j] = (png_uint_16)d;
-# else
- if (shift)
- ig = (ig * 65535U + max_by_2)/max;
-
- sub_table[j] = png_gamma_16bit_correct(ig, gamma_val);
-# endif
- }
- }
- else
- {
- /* We must still build a table, but do it the fast way. */
- unsigned int j;
-
- for (j = 0; j < 256; j++)
- {
- png_uint_32 ig = (j << (8-shift)) + i;
-
- if (shift)
- ig = (ig * 65535U + max_by_2)/max;
-
- sub_table[j] = (png_uint_16)ig;
- }
- }
- }
-}
-
-/* NOTE: this function expects the *inverse* of the overall gamma transformation
- * required.
- */
-static void
-png_build_16to8_table(png_structrp png_ptr, png_uint_16pp *ptable,
- PNG_CONST unsigned int shift, PNG_CONST png_fixed_point gamma_val)
-{
- PNG_CONST unsigned int num = 1U << (8U - shift);
- PNG_CONST unsigned int max = (1U << (16U - shift))-1U;
- unsigned int i;
- png_uint_32 last;
-
- png_uint_16pp table = *ptable =
- (png_uint_16pp)png_calloc(png_ptr, num * (sizeof (png_uint_16p)));
-
- /* 'num' is the number of tables and also the number of low bits of low
- * bits of the input 16-bit value used to select a table. Each table is
- * itself index by the high 8 bits of the value.
- */
- for (i = 0; i < num; i++)
- table[i] = (png_uint_16p)png_malloc(png_ptr,
- 256 * (sizeof (png_uint_16)));
-
- /* 'gamma_val' is set to the reciprocal of the value calculated above, so
- * pow(out,g) is an *input* value. 'last' is the last input value set.
- *
- * In the loop 'i' is used to find output values. Since the output is
- * 8-bit there are only 256 possible values. The tables are set up to
- * select the closest possible output value for each input by finding
- * the input value at the boundary between each pair of output values
- * and filling the table up to that boundary with the lower output
- * value.
- *
- * The boundary values are 0.5,1.5..253.5,254.5. Since these are 9-bit
- * values the code below uses a 16-bit value in i; the values start at
- * 128.5 (for 0.5) and step by 257, for a total of 254 values (the last
- * entries are filled with 255). Start i at 128 and fill all 'last'
- * table entries <= 'max'
- */
- last = 0;
- for (i = 0; i < 255; ++i) /* 8-bit output value */
- {
- /* Find the corresponding maximum input value */
- png_uint_16 out = (png_uint_16)(i * 257U); /* 16-bit output value */
-
- /* Find the boundary value in 16 bits: */
- png_uint_32 bound = png_gamma_16bit_correct(out+128U, gamma_val);
-
- /* Adjust (round) to (16-shift) bits: */
- bound = (bound * max + 32768U)/65535U + 1U;
-
- while (last < bound)
- {
- table[last & (0xffU >> shift)][last >> (8U - shift)] = out;
- last++;
- }
- }
-
- /* And fill in the final entries. */
- while (last < (num << 8))
- {
- table[last & (0xff >> shift)][last >> (8U - shift)] = 65535U;
- last++;
- }
-}
-
-/* Build a single 8-bit table: same as the 16-bit case but much simpler (and
- * typically much faster). Note that libpng currently does no sBIT processing
- * (apparently contrary to the spec) so a 256 entry table is always generated.
- */
-static void
-png_build_8bit_table(png_structrp png_ptr, png_bytepp ptable,
- PNG_CONST png_fixed_point gamma_val)
-{
- unsigned int i;
- png_bytep table = *ptable = (png_bytep)png_malloc(png_ptr, 256);
-
- if (png_gamma_significant(gamma_val)) for (i=0; i<256; i++)
- table[i] = png_gamma_8bit_correct(i, gamma_val);
-
- else for (i=0; i<256; ++i)
- table[i] = (png_byte)i;
-}
-
-/* Used from png_read_destroy and below to release the memory used by the gamma
- * tables.
- */
-void /* PRIVATE */
-png_destroy_gamma_table(png_structrp png_ptr)
-{
- png_free(png_ptr, png_ptr->gamma_table);
- png_ptr->gamma_table = NULL;
-
- if (png_ptr->gamma_16_table != NULL)
- {
- int i;
- int istop = (1 << (8 - png_ptr->gamma_shift));
- for (i = 0; i < istop; i++)
- {
- png_free(png_ptr, png_ptr->gamma_16_table[i]);
- }
- png_free(png_ptr, png_ptr->gamma_16_table);
- png_ptr->gamma_16_table = NULL;
- }
-
-#if defined(PNG_READ_BACKGROUND_SUPPORTED) || \
- defined(PNG_READ_ALPHA_MODE_SUPPORTED) || \
- defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
- png_free(png_ptr, png_ptr->gamma_from_1);
- png_ptr->gamma_from_1 = NULL;
- png_free(png_ptr, png_ptr->gamma_to_1);
- png_ptr->gamma_to_1 = NULL;
-
- if (png_ptr->gamma_16_from_1 != NULL)
- {
- int i;
- int istop = (1 << (8 - png_ptr->gamma_shift));
- for (i = 0; i < istop; i++)
- {
- png_free(png_ptr, png_ptr->gamma_16_from_1[i]);
- }
- png_free(png_ptr, png_ptr->gamma_16_from_1);
- png_ptr->gamma_16_from_1 = NULL;
- }
- if (png_ptr->gamma_16_to_1 != NULL)
- {
- int i;
- int istop = (1 << (8 - png_ptr->gamma_shift));
- for (i = 0; i < istop; i++)
- {
- png_free(png_ptr, png_ptr->gamma_16_to_1[i]);
- }
- png_free(png_ptr, png_ptr->gamma_16_to_1);
- png_ptr->gamma_16_to_1 = NULL;
- }
-#endif /* READ_BACKGROUND || READ_ALPHA_MODE || RGB_TO_GRAY */
-}
-
-/* We build the 8- or 16-bit gamma tables here. Note that for 16-bit
- * tables, we don't make a full table if we are reducing to 8-bit in
- * the future. Note also how the gamma_16 tables are segmented so that
- * we don't need to allocate > 64K chunks for a full 16-bit table.
- */
-void /* PRIVATE */
-png_build_gamma_table(png_structrp png_ptr, int bit_depth)
-{
- png_debug(1, "in png_build_gamma_table");
-
- /* Remove any existing table; this copes with multiple calls to
- * png_read_update_info. The warning is because building the gamma tables
- * multiple times is a performance hit - it's harmless but the ability to call
- * png_read_update_info() multiple times is new in 1.5.6 so it seems sensible
- * to warn if the app introduces such a hit.
- */
- if (png_ptr->gamma_table != NULL || png_ptr->gamma_16_table != NULL)
- {
- png_warning(png_ptr, "gamma table being rebuilt");
- png_destroy_gamma_table(png_ptr);
- }
-
- if (bit_depth <= 8)
- {
- png_build_8bit_table(png_ptr, &png_ptr->gamma_table,
- png_ptr->screen_gamma > 0 ? png_reciprocal2(png_ptr->colorspace.gamma,
- png_ptr->screen_gamma) : PNG_FP_1);
-
-#if defined(PNG_READ_BACKGROUND_SUPPORTED) || \
- defined(PNG_READ_ALPHA_MODE_SUPPORTED) || \
- defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
- if (png_ptr->transformations & (PNG_COMPOSE | PNG_RGB_TO_GRAY))
- {
- png_build_8bit_table(png_ptr, &png_ptr->gamma_to_1,
- png_reciprocal(png_ptr->colorspace.gamma));
-
- png_build_8bit_table(png_ptr, &png_ptr->gamma_from_1,
- png_ptr->screen_gamma > 0 ? png_reciprocal(png_ptr->screen_gamma) :
- png_ptr->colorspace.gamma/* Probably doing rgb_to_gray */);
- }
-#endif /* READ_BACKGROUND || READ_ALPHA_MODE || RGB_TO_GRAY */
- }
- else
- {
- png_byte shift, sig_bit;
-
- if (png_ptr->color_type & PNG_COLOR_MASK_COLOR)
- {
- sig_bit = png_ptr->sig_bit.red;
-
- if (png_ptr->sig_bit.green > sig_bit)
- sig_bit = png_ptr->sig_bit.green;
-
- if (png_ptr->sig_bit.blue > sig_bit)
- sig_bit = png_ptr->sig_bit.blue;
- }
- else
- sig_bit = png_ptr->sig_bit.gray;
-
- /* 16-bit gamma code uses this equation:
- *
- * ov = table[(iv & 0xff) >> gamma_shift][iv >> 8]
- *
- * Where 'iv' is the input color value and 'ov' is the output value -
- * pow(iv, gamma).
- *
- * Thus the gamma table consists of up to 256 256 entry tables. The table
- * is selected by the (8-gamma_shift) most significant of the low 8 bits of
- * the color value then indexed by the upper 8 bits:
- *
- * table[low bits][high 8 bits]
- *
- * So the table 'n' corresponds to all those 'iv' of:
- *
- * <all high 8-bit values><n << gamma_shift>..<(n+1 << gamma_shift)-1>
- *
- */
- if (sig_bit > 0 && sig_bit < 16U)
- shift = (png_byte)(16U - sig_bit); /* shift == insignificant bits */
-
- else
- shift = 0; /* keep all 16 bits */
-
- if (png_ptr->transformations & (PNG_16_TO_8 | PNG_SCALE_16_TO_8))
- {
- /* PNG_MAX_GAMMA_8 is the number of bits to keep - effectively
- * the significant bits in the *input* when the output will
- * eventually be 8 bits. By default it is 11.
- */
- if (shift < (16U - PNG_MAX_GAMMA_8))
- shift = (16U - PNG_MAX_GAMMA_8);
- }
-
- if (shift > 8U)
- shift = 8U; /* Guarantees at least one table! */
-
- png_ptr->gamma_shift = shift;
-
-#ifdef PNG_16BIT_SUPPORTED
- /* NOTE: prior to 1.5.4 this test used to include PNG_BACKGROUND (now
- * PNG_COMPOSE). This effectively smashed the background calculation for
- * 16-bit output because the 8-bit table assumes the result will be reduced
- * to 8 bits.
- */
- if (png_ptr->transformations & (PNG_16_TO_8 | PNG_SCALE_16_TO_8))
-#endif
- png_build_16to8_table(png_ptr, &png_ptr->gamma_16_table, shift,
- png_ptr->screen_gamma > 0 ? png_product2(png_ptr->colorspace.gamma,
- png_ptr->screen_gamma) : PNG_FP_1);
-
-#ifdef PNG_16BIT_SUPPORTED
- else
- png_build_16bit_table(png_ptr, &png_ptr->gamma_16_table, shift,
- png_ptr->screen_gamma > 0 ? png_reciprocal2(png_ptr->colorspace.gamma,
- png_ptr->screen_gamma) : PNG_FP_1);
-#endif
-
-#if defined(PNG_READ_BACKGROUND_SUPPORTED) || \
- defined(PNG_READ_ALPHA_MODE_SUPPORTED) || \
- defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
- if (png_ptr->transformations & (PNG_COMPOSE | PNG_RGB_TO_GRAY))
- {
- png_build_16bit_table(png_ptr, &png_ptr->gamma_16_to_1, shift,
- png_reciprocal(png_ptr->colorspace.gamma));
-
- /* Notice that the '16 from 1' table should be full precision, however
- * the lookup on this table still uses gamma_shift, so it can't be.
- * TODO: fix this.
- */
- png_build_16bit_table(png_ptr, &png_ptr->gamma_16_from_1, shift,
- png_ptr->screen_gamma > 0 ? png_reciprocal(png_ptr->screen_gamma) :
- png_ptr->colorspace.gamma/* Probably doing rgb_to_gray */);
- }
-#endif /* READ_BACKGROUND || READ_ALPHA_MODE || RGB_TO_GRAY */
- }
-}
-#endif /* READ_GAMMA */
-
-/* HARDWARE OPTION SUPPORT */
-#ifdef PNG_SET_OPTION_SUPPORTED
-int PNGAPI
-png_set_option(png_structrp png_ptr, int option, int onoff)
-{
- if (png_ptr != NULL && option >= 0 && option < PNG_OPTION_NEXT &&
- (option & 1) == 0)
- {
- int mask = 3 << option;
- int setting = (2 + (onoff != 0)) << option;
- int current = png_ptr->options;
-
- png_ptr->options = (png_byte)((current & ~mask) | setting);
-
- return (current & mask) >> option;
- }
-
- return PNG_OPTION_INVALID;
-}
-#endif
-
-/* sRGB support */
-#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) ||\
- defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
-/* sRGB conversion tables; these are machine generated with the code in
- * contrib/tools/makesRGB.c. The actual sRGB transfer curve defined in the
- * specification (see the article at http://en.wikipedia.org/wiki/SRGB)
- * is used, not the gamma=1/2.2 approximation use elsewhere in libpng.
- * The sRGB to linear table is exact (to the nearest 16 bit linear fraction).
- * The inverse (linear to sRGB) table has accuracies as follows:
- *
- * For all possible (255*65535+1) input values:
- *
- * error: -0.515566 - 0.625971, 79441 (0.475369%) of readings inexact
- *
- * For the input values corresponding to the 65536 16-bit values:
- *
- * error: -0.513727 - 0.607759, 308 (0.469978%) of readings inexact
- *
- * In all cases the inexact readings are off by one.
- */
-
-#ifdef PNG_SIMPLIFIED_READ_SUPPORTED
-/* The convert-to-sRGB table is only currently required for read. */
-const png_uint_16 png_sRGB_table[256] =
-{
- 0,20,40,60,80,99,119,139,
- 159,179,199,219,241,264,288,313,
- 340,367,396,427,458,491,526,562,
- 599,637,677,718,761,805,851,898,
- 947,997,1048,1101,1156,1212,1270,1330,
- 1391,1453,1517,1583,1651,1720,1790,1863,
- 1937,2013,2090,2170,2250,2333,2418,2504,
- 2592,2681,2773,2866,2961,3058,3157,3258,
- 3360,3464,3570,3678,3788,3900,4014,4129,
- 4247,4366,4488,4611,4736,4864,4993,5124,
- 5257,5392,5530,5669,5810,5953,6099,6246,
- 6395,6547,6700,6856,7014,7174,7335,7500,
- 7666,7834,8004,8177,8352,8528,8708,8889,
- 9072,9258,9445,9635,9828,10022,10219,10417,
- 10619,10822,11028,11235,11446,11658,11873,12090,
- 12309,12530,12754,12980,13209,13440,13673,13909,
- 14146,14387,14629,14874,15122,15371,15623,15878,
- 16135,16394,16656,16920,17187,17456,17727,18001,
- 18277,18556,18837,19121,19407,19696,19987,20281,
- 20577,20876,21177,21481,21787,22096,22407,22721,
- 23038,23357,23678,24002,24329,24658,24990,25325,
- 25662,26001,26344,26688,27036,27386,27739,28094,
- 28452,28813,29176,29542,29911,30282,30656,31033,
- 31412,31794,32179,32567,32957,33350,33745,34143,
- 34544,34948,35355,35764,36176,36591,37008,37429,
- 37852,38278,38706,39138,39572,40009,40449,40891,
- 41337,41785,42236,42690,43147,43606,44069,44534,
- 45002,45473,45947,46423,46903,47385,47871,48359,
- 48850,49344,49841,50341,50844,51349,51858,52369,
- 52884,53401,53921,54445,54971,55500,56032,56567,
- 57105,57646,58190,58737,59287,59840,60396,60955,
- 61517,62082,62650,63221,63795,64372,64952,65535
-};
-
-#endif /* simplified read only */
-
-/* The base/delta tables are required for both read and write (but currently
- * only the simplified versions.)
- */
-const png_uint_16 png_sRGB_base[512] =
-{
- 128,1782,3383,4644,5675,6564,7357,8074,
- 8732,9346,9921,10463,10977,11466,11935,12384,
- 12816,13233,13634,14024,14402,14769,15125,15473,
- 15812,16142,16466,16781,17090,17393,17690,17981,
- 18266,18546,18822,19093,19359,19621,19879,20133,
- 20383,20630,20873,21113,21349,21583,21813,22041,
- 22265,22487,22707,22923,23138,23350,23559,23767,
- 23972,24175,24376,24575,24772,24967,25160,25352,
- 25542,25730,25916,26101,26284,26465,26645,26823,
- 27000,27176,27350,27523,27695,27865,28034,28201,
- 28368,28533,28697,28860,29021,29182,29341,29500,
- 29657,29813,29969,30123,30276,30429,30580,30730,
- 30880,31028,31176,31323,31469,31614,31758,31902,
- 32045,32186,32327,32468,32607,32746,32884,33021,
- 33158,33294,33429,33564,33697,33831,33963,34095,
- 34226,34357,34486,34616,34744,34873,35000,35127,
- 35253,35379,35504,35629,35753,35876,35999,36122,
- 36244,36365,36486,36606,36726,36845,36964,37083,
- 37201,37318,37435,37551,37668,37783,37898,38013,
- 38127,38241,38354,38467,38580,38692,38803,38915,
- 39026,39136,39246,39356,39465,39574,39682,39790,
- 39898,40005,40112,40219,40325,40431,40537,40642,
- 40747,40851,40955,41059,41163,41266,41369,41471,
- 41573,41675,41777,41878,41979,42079,42179,42279,
- 42379,42478,42577,42676,42775,42873,42971,43068,
- 43165,43262,43359,43456,43552,43648,43743,43839,
- 43934,44028,44123,44217,44311,44405,44499,44592,
- 44685,44778,44870,44962,45054,45146,45238,45329,
- 45420,45511,45601,45692,45782,45872,45961,46051,
- 46140,46229,46318,46406,46494,46583,46670,46758,
- 46846,46933,47020,47107,47193,47280,47366,47452,
- 47538,47623,47709,47794,47879,47964,48048,48133,
- 48217,48301,48385,48468,48552,48635,48718,48801,
- 48884,48966,49048,49131,49213,49294,49376,49458,
- 49539,49620,49701,49782,49862,49943,50023,50103,
- 50183,50263,50342,50422,50501,50580,50659,50738,
- 50816,50895,50973,51051,51129,51207,51285,51362,
- 51439,51517,51594,51671,51747,51824,51900,51977,
- 52053,52129,52205,52280,52356,52432,52507,52582,
- 52657,52732,52807,52881,52956,53030,53104,53178,
- 53252,53326,53400,53473,53546,53620,53693,53766,
- 53839,53911,53984,54056,54129,54201,54273,54345,
- 54417,54489,54560,54632,54703,54774,54845,54916,
- 54987,55058,55129,55199,55269,55340,55410,55480,
- 55550,55620,55689,55759,55828,55898,55967,56036,
- 56105,56174,56243,56311,56380,56448,56517,56585,
- 56653,56721,56789,56857,56924,56992,57059,57127,
- 57194,57261,57328,57395,57462,57529,57595,57662,
- 57728,57795,57861,57927,57993,58059,58125,58191,
- 58256,58322,58387,58453,58518,58583,58648,58713,
- 58778,58843,58908,58972,59037,59101,59165,59230,
- 59294,59358,59422,59486,59549,59613,59677,59740,
- 59804,59867,59930,59993,60056,60119,60182,60245,
- 60308,60370,60433,60495,60558,60620,60682,60744,
- 60806,60868,60930,60992,61054,61115,61177,61238,
- 61300,61361,61422,61483,61544,61605,61666,61727,
- 61788,61848,61909,61969,62030,62090,62150,62211,
- 62271,62331,62391,62450,62510,62570,62630,62689,
- 62749,62808,62867,62927,62986,63045,63104,63163,
- 63222,63281,63340,63398,63457,63515,63574,63632,
- 63691,63749,63807,63865,63923,63981,64039,64097,
- 64155,64212,64270,64328,64385,64443,64500,64557,
- 64614,64672,64729,64786,64843,64900,64956,65013,
- 65070,65126,65183,65239,65296,65352,65409,65465
-};
-
-const png_byte png_sRGB_delta[512] =
-{
- 207,201,158,129,113,100,90,82,77,72,68,64,61,59,56,54,
- 52,50,49,47,46,45,43,42,41,40,39,39,38,37,36,36,
- 35,34,34,33,33,32,32,31,31,30,30,30,29,29,28,28,
- 28,27,27,27,27,26,26,26,25,25,25,25,24,24,24,24,
- 23,23,23,23,23,22,22,22,22,22,22,21,21,21,21,21,
- 21,20,20,20,20,20,20,20,20,19,19,19,19,19,19,19,
- 19,18,18,18,18,18,18,18,18,18,18,17,17,17,17,17,
- 17,17,17,17,17,17,16,16,16,16,16,16,16,16,16,16,
- 16,16,16,16,15,15,15,15,15,15,15,15,15,15,15,15,
- 15,15,15,15,14,14,14,14,14,14,14,14,14,14,14,14,
- 14,14,14,14,14,14,14,13,13,13,13,13,13,13,13,13,
- 13,13,13,13,13,13,13,13,13,13,13,13,13,13,12,12,
- 12,12,12,12,12,12,12,12,12,12,12,12,12,12,12,12,
- 12,12,12,12,12,12,12,12,12,12,12,12,11,11,11,11,
- 11,11,11,11,11,11,11,11,11,11,11,11,11,11,11,11,
- 11,11,11,11,11,11,11,11,11,11,11,11,11,11,11,11,
- 11,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,
- 10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,
- 10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,
- 10,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,
- 9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,
- 9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,
- 9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,
- 9,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
- 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
- 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
- 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
- 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
- 8,8,8,8,8,8,8,8,8,7,7,7,7,7,7,7,
- 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
- 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
- 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7
-};
-#endif /* SIMPLIFIED READ/WRITE sRGB support */
-
-/* SIMPLIFIED READ/WRITE SUPPORT */
-#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) ||\
- defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
-static int
-png_image_free_function(png_voidp argument)
-{
- png_imagep image = png_voidcast(png_imagep, argument);
- png_controlp cp = image->opaque;
- png_control c;
-
- /* Double check that we have a png_ptr - it should be impossible to get here
- * without one.
- */
- if (cp->png_ptr == NULL)
- return 0;
-
- /* First free any data held in the control structure. */
-# ifdef PNG_STDIO_SUPPORTED
- if (cp->owned_file)
- {
- FILE *fp = png_voidcast(FILE*, cp->png_ptr->io_ptr);
- cp->owned_file = 0;
-
- /* Ignore errors here. */
- if (fp != NULL)
- {
- cp->png_ptr->io_ptr = NULL;
- (void)fclose(fp);
- }
- }
-# endif
-
- /* Copy the control structure so that the original, allocated, version can be
- * safely freed. Notice that a png_error here stops the remainder of the
- * cleanup, but this is probably fine because that would indicate bad memory
- * problems anyway.
- */
- c = *cp;
- image->opaque = &c;
- png_free(c.png_ptr, cp);
-
- /* Then the structures, calling the correct API. */
- if (c.for_write)
- {
-# ifdef PNG_SIMPLIFIED_WRITE_SUPPORTED
- png_destroy_write_struct(&c.png_ptr, &c.info_ptr);
-# else
- png_error(c.png_ptr, "simplified write not supported");
-# endif
- }
- else
- {
-# ifdef PNG_SIMPLIFIED_READ_SUPPORTED
- png_destroy_read_struct(&c.png_ptr, &c.info_ptr, NULL);
-# else
- png_error(c.png_ptr, "simplified read not supported");
-# endif
- }
-
- /* Success. */
- return 1;
-}
-
-void PNGAPI
-png_image_free(png_imagep image)
-{
- /* Safely call the real function, but only if doing so is safe at this point
- * (if not inside an error handling context). Otherwise assume
- * png_safe_execute will call this API after the return.
- */
- if (image != NULL && image->opaque != NULL &&
- image->opaque->error_buf == NULL)
- {
- /* Ignore errors here: */
- (void)png_safe_execute(image, png_image_free_function, image);
- image->opaque = NULL;
- }
-}
-
-int /* PRIVATE */
-png_image_error(png_imagep image, png_const_charp error_message)
-{
- /* Utility to log an error. */
- png_safecat(image->message, (sizeof image->message), 0, error_message);
- image->warning_or_error |= PNG_IMAGE_ERROR;
- png_image_free(image);
- return 0;
-}
-
-#endif /* SIMPLIFIED READ/WRITE */
-#endif /* defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) */
+
+/* png.c - location for general purpose libpng functions
+ *
+ * Last changed in libpng 1.6.19 [November 12, 2015]
+ * Copyright (c) 1998-2015 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+
+#include "pngpriv.h"
+
+/* Generate a compiler error if there is an old png.h in the search path. */
+typedef png_libpng_version_1_6_20 Your_png_h_is_not_version_1_6_20;
+
+/* Tells libpng that we have already handled the first "num_bytes" bytes
+ * of the PNG file signature. If the PNG data is embedded into another
+ * stream we can set num_bytes = 8 so that libpng will not attempt to read
+ * or write any of the magic bytes before it starts on the IHDR.
+ */
+
+#ifdef PNG_READ_SUPPORTED
+void PNGAPI
+png_set_sig_bytes(png_structrp png_ptr, int num_bytes)
+{
+ unsigned int nb = (unsigned int)num_bytes;
+
+ png_debug(1, "in png_set_sig_bytes");
+
+ if (png_ptr == NULL)
+ return;
+
+ if (num_bytes < 0)
+ nb = 0;
+
+ if (nb > 8)
+ png_error(png_ptr, "Too many bytes for PNG signature");
+
+ png_ptr->sig_bytes = (png_byte)nb;
+}
+
+/* Checks whether the supplied bytes match the PNG signature. We allow
+ * checking less than the full 8-byte signature so that those apps that
+ * already read the first few bytes of a file to determine the file type
+ * can simply check the remaining bytes for extra assurance. Returns
+ * an integer less than, equal to, or greater than zero if sig is found,
+ * respectively, to be less than, to match, or be greater than the correct
+ * PNG signature (this is the same behavior as strcmp, memcmp, etc).
+ */
+int PNGAPI
+png_sig_cmp(png_const_bytep sig, png_size_t start, png_size_t num_to_check)
+{
+ png_byte png_signature[8] = {137, 80, 78, 71, 13, 10, 26, 10};
+
+ if (num_to_check > 8)
+ num_to_check = 8;
+
+ else if (num_to_check < 1)
+ return (-1);
+
+ if (start > 7)
+ return (-1);
+
+ if (start + num_to_check > 8)
+ num_to_check = 8 - start;
+
+ return ((int)(memcmp(&sig[start], &png_signature[start], num_to_check)));
+}
+
+#endif /* READ */
+
+#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
+/* Function to allocate memory for zlib */
+PNG_FUNCTION(voidpf /* PRIVATE */,
+png_zalloc,(voidpf png_ptr, uInt items, uInt size),PNG_ALLOCATED)
+{
+ png_alloc_size_t num_bytes = size;
+
+ if (png_ptr == NULL)
+ return NULL;
+
+ if (items >= (~(png_alloc_size_t)0)/size)
+ {
+ png_warning (png_voidcast(png_structrp, png_ptr),
+ "Potential overflow in png_zalloc()");
+ return NULL;
+ }
+
+ num_bytes *= items;
+ return png_malloc_warn(png_voidcast(png_structrp, png_ptr), num_bytes);
+}
+
+/* Function to free memory for zlib */
+void /* PRIVATE */
+png_zfree(voidpf png_ptr, voidpf ptr)
+{
+ png_free(png_voidcast(png_const_structrp,png_ptr), ptr);
+}
+
+/* Reset the CRC variable to 32 bits of 1's. Care must be taken
+ * in case CRC is > 32 bits to leave the top bits 0.
+ */
+void /* PRIVATE */
+png_reset_crc(png_structrp png_ptr)
+{
+ /* The cast is safe because the crc is a 32-bit value. */
+ png_ptr->crc = (png_uint_32)crc32(0, Z_NULL, 0);
+}
+
+/* Calculate the CRC over a section of data. We can only pass as
+ * much data to this routine as the largest single buffer size. We
+ * also check that this data will actually be used before going to the
+ * trouble of calculating it.
+ */
+void /* PRIVATE */
+png_calculate_crc(png_structrp png_ptr, png_const_bytep ptr, png_size_t length)
+{
+ int need_crc = 1;
+
+ if (PNG_CHUNK_ANCILLARY(png_ptr->chunk_name) != 0)
+ {
+ if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_MASK) ==
+ (PNG_FLAG_CRC_ANCILLARY_USE | PNG_FLAG_CRC_ANCILLARY_NOWARN))
+ need_crc = 0;
+ }
+
+ else /* critical */
+ {
+ if ((png_ptr->flags & PNG_FLAG_CRC_CRITICAL_IGNORE) != 0)
+ need_crc = 0;
+ }
+
+ /* 'uLong' is defined in zlib.h as unsigned long; this means that on some
+ * systems it is a 64-bit value. crc32, however, returns 32 bits so the
+ * following cast is safe. 'uInt' may be no more than 16 bits, so it is
+ * necessary to perform a loop here.
+ */
+ if (need_crc != 0 && length > 0)
+ {
+ uLong crc = png_ptr->crc; /* Should never issue a warning */
+
+ do
+ {
+ uInt safe_length = (uInt)length;
+#ifndef __COVERITY__
+ if (safe_length == 0)
+ safe_length = (uInt)-1; /* evil, but safe */
+#endif
+
+ crc = crc32(crc, ptr, safe_length);
+
+ /* The following should never issue compiler warnings; if they do the
+ * target system has characteristics that will probably violate other
+ * assumptions within the libpng code.
+ */
+ ptr += safe_length;
+ length -= safe_length;
+ }
+ while (length > 0);
+
+ /* And the following is always safe because the crc is only 32 bits. */
+ png_ptr->crc = (png_uint_32)crc;
+ }
+}
+
+/* Check a user supplied version number, called from both read and write
+ * functions that create a png_struct.
+ */
+int
+png_user_version_check(png_structrp png_ptr, png_const_charp user_png_ver)
+{
+ /* Libpng versions 1.0.0 and later are binary compatible if the version
+ * string matches through the second '.'; we must recompile any
+ * applications that use any older library version.
+ */
+
+ if (user_png_ver != NULL)
+ {
+ int i = -1;
+ int found_dots = 0;
+
+ do
+ {
+ i++;
+ if (user_png_ver[i] != PNG_LIBPNG_VER_STRING[i])
+ png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
+ if (user_png_ver[i] == '.')
+ found_dots++;
+ } while (found_dots < 2 && user_png_ver[i] != 0 &&
+ PNG_LIBPNG_VER_STRING[i] != 0);
+ }
+
+ else
+ png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
+
+ if ((png_ptr->flags & PNG_FLAG_LIBRARY_MISMATCH) != 0)
+ {
+#ifdef PNG_WARNINGS_SUPPORTED
+ size_t pos = 0;
+ char m[128];
+
+ pos = png_safecat(m, (sizeof m), pos,
+ "Application built with libpng-");
+ pos = png_safecat(m, (sizeof m), pos, user_png_ver);
+ pos = png_safecat(m, (sizeof m), pos, " but running with ");
+ pos = png_safecat(m, (sizeof m), pos, PNG_LIBPNG_VER_STRING);
+ PNG_UNUSED(pos)
+
+ png_warning(png_ptr, m);
+#endif
+
+#ifdef PNG_ERROR_NUMBERS_SUPPORTED
+ png_ptr->flags = 0;
+#endif
+
+ return 0;
+ }
+
+ /* Success return. */
+ return 1;
+}
+
+/* Generic function to create a png_struct for either read or write - this
+ * contains the common initialization.
+ */
+PNG_FUNCTION(png_structp /* PRIVATE */,
+png_create_png_struct,(png_const_charp user_png_ver, png_voidp error_ptr,
+ png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
+ png_malloc_ptr malloc_fn, png_free_ptr free_fn),PNG_ALLOCATED)
+{
+ png_struct create_struct;
+# ifdef PNG_SETJMP_SUPPORTED
+ jmp_buf create_jmp_buf;
+# endif
+
+ /* This temporary stack-allocated structure is used to provide a place to
+ * build enough context to allow the user provided memory allocator (if any)
+ * to be called.
+ */
+ memset(&create_struct, 0, (sizeof create_struct));
+
+ /* Added at libpng-1.2.6 */
+# ifdef PNG_USER_LIMITS_SUPPORTED
+ create_struct.user_width_max = PNG_USER_WIDTH_MAX;
+ create_struct.user_height_max = PNG_USER_HEIGHT_MAX;
+
+# ifdef PNG_USER_CHUNK_CACHE_MAX
+ /* Added at libpng-1.2.43 and 1.4.0 */
+ create_struct.user_chunk_cache_max = PNG_USER_CHUNK_CACHE_MAX;
+# endif
+
+# ifdef PNG_USER_CHUNK_MALLOC_MAX
+ /* Added at libpng-1.2.43 and 1.4.1, required only for read but exists
+ * in png_struct regardless.
+ */
+ create_struct.user_chunk_malloc_max = PNG_USER_CHUNK_MALLOC_MAX;
+# endif
+# endif
+
+ /* The following two API calls simply set fields in png_struct, so it is safe
+ * to do them now even though error handling is not yet set up.
+ */
+# ifdef PNG_USER_MEM_SUPPORTED
+ png_set_mem_fn(&create_struct, mem_ptr, malloc_fn, free_fn);
+# else
+ PNG_UNUSED(mem_ptr)
+ PNG_UNUSED(malloc_fn)
+ PNG_UNUSED(free_fn)
+# endif
+
+ /* (*error_fn) can return control to the caller after the error_ptr is set,
+ * this will result in a memory leak unless the error_fn does something
+ * extremely sophisticated. The design lacks merit but is implicit in the
+ * API.
+ */
+ png_set_error_fn(&create_struct, error_ptr, error_fn, warn_fn);
+
+# ifdef PNG_SETJMP_SUPPORTED
+ if (!setjmp(create_jmp_buf))
+# endif
+ {
+# ifdef PNG_SETJMP_SUPPORTED
+ /* Temporarily fake out the longjmp information until we have
+ * successfully completed this function. This only works if we have
+ * setjmp() support compiled in, but it is safe - this stuff should
+ * never happen.
+ */
+ create_struct.jmp_buf_ptr = &create_jmp_buf;
+ create_struct.jmp_buf_size = 0; /*stack allocation*/
+ create_struct.longjmp_fn = longjmp;
+# endif
+ /* Call the general version checker (shared with read and write code):
+ */
+ if (png_user_version_check(&create_struct, user_png_ver) != 0)
+ {
+ png_structrp png_ptr = png_voidcast(png_structrp,
+ png_malloc_warn(&create_struct, (sizeof *png_ptr)));
+
+ if (png_ptr != NULL)
+ {
+ /* png_ptr->zstream holds a back-pointer to the png_struct, so
+ * this can only be done now:
+ */
+ create_struct.zstream.zalloc = png_zalloc;
+ create_struct.zstream.zfree = png_zfree;
+ create_struct.zstream.opaque = png_ptr;
+
+# ifdef PNG_SETJMP_SUPPORTED
+ /* Eliminate the local error handling: */
+ create_struct.jmp_buf_ptr = NULL;
+ create_struct.jmp_buf_size = 0;
+ create_struct.longjmp_fn = 0;
+# endif
+
+ *png_ptr = create_struct;
+
+ /* This is the successful return point */
+ return png_ptr;
+ }
+ }
+ }
+
+ /* A longjmp because of a bug in the application storage allocator or a
+ * simple failure to allocate the png_struct.
+ */
+ return NULL;
+}
+
+/* Allocate the memory for an info_struct for the application. */
+PNG_FUNCTION(png_infop,PNGAPI
+png_create_info_struct,(png_const_structrp png_ptr),PNG_ALLOCATED)
+{
+ png_inforp info_ptr;
+
+ png_debug(1, "in png_create_info_struct");
+
+ if (png_ptr == NULL)
+ return NULL;
+
+ /* Use the internal API that does not (or at least should not) error out, so
+ * that this call always returns ok. The application typically sets up the
+ * error handling *after* creating the info_struct because this is the way it
+ * has always been done in 'example.c'.
+ */
+ info_ptr = png_voidcast(png_inforp, png_malloc_base(png_ptr,
+ (sizeof *info_ptr)));
+
+ if (info_ptr != NULL)
+ memset(info_ptr, 0, (sizeof *info_ptr));
+
+ return info_ptr;
+}
+
+/* This function frees the memory associated with a single info struct.
+ * Normally, one would use either png_destroy_read_struct() or
+ * png_destroy_write_struct() to free an info struct, but this may be
+ * useful for some applications. From libpng 1.6.0 this function is also used
+ * internally to implement the png_info release part of the 'struct' destroy
+ * APIs. This ensures that all possible approaches free the same data (all of
+ * it).
+ */
+void PNGAPI
+png_destroy_info_struct(png_const_structrp png_ptr, png_infopp info_ptr_ptr)
+{
+ png_inforp info_ptr = NULL;
+
+ png_debug(1, "in png_destroy_info_struct");
+
+ if (png_ptr == NULL)
+ return;
+
+ if (info_ptr_ptr != NULL)
+ info_ptr = *info_ptr_ptr;
+
+ if (info_ptr != NULL)
+ {
+ /* Do this first in case of an error below; if the app implements its own
+ * memory management this can lead to png_free calling png_error, which
+ * will abort this routine and return control to the app error handler.
+ * An infinite loop may result if it then tries to free the same info
+ * ptr.
+ */
+ *info_ptr_ptr = NULL;
+
+ png_free_data(png_ptr, info_ptr, PNG_FREE_ALL, -1);
+ memset(info_ptr, 0, (sizeof *info_ptr));
+ png_free(png_ptr, info_ptr);
+ }
+}
+
+/* Initialize the info structure. This is now an internal function (0.89)
+ * and applications using it are urged to use png_create_info_struct()
+ * instead. Use deprecated in 1.6.0, internal use removed (used internally it
+ * is just a memset).
+ *
+ * NOTE: it is almost inconceivable that this API is used because it bypasses
+ * the user-memory mechanism and the user error handling/warning mechanisms in
+ * those cases where it does anything other than a memset.
+ */
+PNG_FUNCTION(void,PNGAPI
+png_info_init_3,(png_infopp ptr_ptr, png_size_t png_info_struct_size),
+ PNG_DEPRECATED)
+{
+ png_inforp info_ptr = *ptr_ptr;
+
+ png_debug(1, "in png_info_init_3");
+
+ if (info_ptr == NULL)
+ return;
+
+ if ((sizeof (png_info)) > png_info_struct_size)
+ {
+ *ptr_ptr = NULL;
+ /* The following line is why this API should not be used: */
+ free(info_ptr);
+ info_ptr = png_voidcast(png_inforp, png_malloc_base(NULL,
+ (sizeof *info_ptr)));
+ if (info_ptr == NULL)
+ return;
+ *ptr_ptr = info_ptr;
+ }
+
+ /* Set everything to 0 */
+ memset(info_ptr, 0, (sizeof *info_ptr));
+}
+
+/* The following API is not called internally */
+void PNGAPI
+png_data_freer(png_const_structrp png_ptr, png_inforp info_ptr,
+ int freer, png_uint_32 mask)
+{
+ png_debug(1, "in png_data_freer");
+
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+ if (freer == PNG_DESTROY_WILL_FREE_DATA)
+ info_ptr->free_me |= mask;
+
+ else if (freer == PNG_USER_WILL_FREE_DATA)
+ info_ptr->free_me &= ~mask;
+
+ else
+ png_error(png_ptr, "Unknown freer parameter in png_data_freer");
+}
+
+void PNGAPI
+png_free_data(png_const_structrp png_ptr, png_inforp info_ptr, png_uint_32 mask,
+ int num)
+{
+ png_debug(1, "in png_free_data");
+
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+#ifdef PNG_TEXT_SUPPORTED
+ /* Free text item num or (if num == -1) all text items */
+ if (info_ptr->text != 0 &&
+ ((mask & PNG_FREE_TEXT) & info_ptr->free_me) != 0)
+ {
+ if (num != -1)
+ {
+ png_free(png_ptr, info_ptr->text[num].key);
+ info_ptr->text[num].key = NULL;
+ }
+
+ else
+ {
+ int i;
+
+ for (i = 0; i < info_ptr->num_text; i++)
+ png_free(png_ptr, info_ptr->text[i].key);
+
+ png_free(png_ptr, info_ptr->text);
+ info_ptr->text = NULL;
+ info_ptr->num_text = 0;
+ }
+ }
+#endif
+
+#ifdef PNG_tRNS_SUPPORTED
+ /* Free any tRNS entry */
+ if (((mask & PNG_FREE_TRNS) & info_ptr->free_me) != 0)
+ {
+ info_ptr->valid &= ~PNG_INFO_tRNS;
+ png_free(png_ptr, info_ptr->trans_alpha);
+ info_ptr->trans_alpha = NULL;
+ info_ptr->num_trans = 0;
+ }
+#endif
+
+#ifdef PNG_sCAL_SUPPORTED
+ /* Free any sCAL entry */
+ if (((mask & PNG_FREE_SCAL) & info_ptr->free_me) != 0)
+ {
+ png_free(png_ptr, info_ptr->scal_s_width);
+ png_free(png_ptr, info_ptr->scal_s_height);
+ info_ptr->scal_s_width = NULL;
+ info_ptr->scal_s_height = NULL;
+ info_ptr->valid &= ~PNG_INFO_sCAL;
+ }
+#endif
+
+#ifdef PNG_pCAL_SUPPORTED
+ /* Free any pCAL entry */
+ if (((mask & PNG_FREE_PCAL) & info_ptr->free_me) != 0)
+ {
+ png_free(png_ptr, info_ptr->pcal_purpose);
+ png_free(png_ptr, info_ptr->pcal_units);
+ info_ptr->pcal_purpose = NULL;
+ info_ptr->pcal_units = NULL;
+
+ if (info_ptr->pcal_params != NULL)
+ {
+ int i;
+
+ for (i = 0; i < info_ptr->pcal_nparams; i++)
+ png_free(png_ptr, info_ptr->pcal_params[i]);
+
+ png_free(png_ptr, info_ptr->pcal_params);
+ info_ptr->pcal_params = NULL;
+ }
+ info_ptr->valid &= ~PNG_INFO_pCAL;
+ }
+#endif
+
+#ifdef PNG_iCCP_SUPPORTED
+ /* Free any profile entry */
+ if (((mask & PNG_FREE_ICCP) & info_ptr->free_me) != 0)
+ {
+ png_free(png_ptr, info_ptr->iccp_name);
+ png_free(png_ptr, info_ptr->iccp_profile);
+ info_ptr->iccp_name = NULL;
+ info_ptr->iccp_profile = NULL;
+ info_ptr->valid &= ~PNG_INFO_iCCP;
+ }
+#endif
+
+#ifdef PNG_sPLT_SUPPORTED
+ /* Free a given sPLT entry, or (if num == -1) all sPLT entries */
+ if (info_ptr->splt_palettes != 0 &&
+ ((mask & PNG_FREE_SPLT) & info_ptr->free_me) != 0)
+ {
+ if (num != -1)
+ {
+ png_free(png_ptr, info_ptr->splt_palettes[num].name);
+ png_free(png_ptr, info_ptr->splt_palettes[num].entries);
+ info_ptr->splt_palettes[num].name = NULL;
+ info_ptr->splt_palettes[num].entries = NULL;
+ }
+
+ else
+ {
+ int i;
+
+ for (i = 0; i < info_ptr->splt_palettes_num; i++)
+ {
+ png_free(png_ptr, info_ptr->splt_palettes[i].name);
+ png_free(png_ptr, info_ptr->splt_palettes[i].entries);
+ }
+
+ png_free(png_ptr, info_ptr->splt_palettes);
+ info_ptr->splt_palettes = NULL;
+ info_ptr->splt_palettes_num = 0;
+ info_ptr->valid &= ~PNG_INFO_sPLT;
+ }
+ }
+#endif
+
+#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
+ if (info_ptr->unknown_chunks != 0 &&
+ ((mask & PNG_FREE_UNKN) & info_ptr->free_me) != 0)
+ {
+ if (num != -1)
+ {
+ png_free(png_ptr, info_ptr->unknown_chunks[num].data);
+ info_ptr->unknown_chunks[num].data = NULL;
+ }
+
+ else
+ {
+ int i;
+
+ for (i = 0; i < info_ptr->unknown_chunks_num; i++)
+ png_free(png_ptr, info_ptr->unknown_chunks[i].data);
+
+ png_free(png_ptr, info_ptr->unknown_chunks);
+ info_ptr->unknown_chunks = NULL;
+ info_ptr->unknown_chunks_num = 0;
+ }
+ }
+#endif
+
+#ifdef PNG_hIST_SUPPORTED
+ /* Free any hIST entry */
+ if (((mask & PNG_FREE_HIST) & info_ptr->free_me) != 0)
+ {
+ png_free(png_ptr, info_ptr->hist);
+ info_ptr->hist = NULL;
+ info_ptr->valid &= ~PNG_INFO_hIST;
+ }
+#endif
+
+ /* Free any PLTE entry that was internally allocated */
+ if (((mask & PNG_FREE_PLTE) & info_ptr->free_me) != 0)
+ {
+ png_free(png_ptr, info_ptr->palette);
+ info_ptr->palette = NULL;
+ info_ptr->valid &= ~PNG_INFO_PLTE;
+ info_ptr->num_palette = 0;
+ }
+
+#ifdef PNG_INFO_IMAGE_SUPPORTED
+ /* Free any image bits attached to the info structure */
+ if (((mask & PNG_FREE_ROWS) & info_ptr->free_me) != 0)
+ {
+ if (info_ptr->row_pointers != 0)
+ {
+ png_uint_32 row;
+ for (row = 0; row < info_ptr->height; row++)
+ png_free(png_ptr, info_ptr->row_pointers[row]);
+
+ png_free(png_ptr, info_ptr->row_pointers);
+ info_ptr->row_pointers = NULL;
+ }
+ info_ptr->valid &= ~PNG_INFO_IDAT;
+ }
+#endif
+
+ if (num != -1)
+ mask &= ~PNG_FREE_MUL;
+
+ info_ptr->free_me &= ~mask;
+}
+#endif /* READ || WRITE */
+
+/* This function returns a pointer to the io_ptr associated with the user
+ * functions. The application should free any memory associated with this
+ * pointer before png_write_destroy() or png_read_destroy() are called.
+ */
+png_voidp PNGAPI
+png_get_io_ptr(png_const_structrp png_ptr)
+{
+ if (png_ptr == NULL)
+ return (NULL);
+
+ return (png_ptr->io_ptr);
+}
+
+#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
+# ifdef PNG_STDIO_SUPPORTED
+/* Initialize the default input/output functions for the PNG file. If you
+ * use your own read or write routines, you can call either png_set_read_fn()
+ * or png_set_write_fn() instead of png_init_io(). If you have defined
+ * PNG_NO_STDIO or otherwise disabled PNG_STDIO_SUPPORTED, you must use a
+ * function of your own because "FILE *" isn't necessarily available.
+ */
+void PNGAPI
+png_init_io(png_structrp png_ptr, png_FILE_p fp)
+{
+ png_debug(1, "in png_init_io");
+
+ if (png_ptr == NULL)
+ return;
+
+ png_ptr->io_ptr = (png_voidp)fp;
+}
+# endif
+
+# ifdef PNG_SAVE_INT_32_SUPPORTED
+/* PNG signed integers are saved in 32-bit 2's complement format. ANSI C-90
+ * defines a cast of a signed integer to an unsigned integer either to preserve
+ * the value, if it is positive, or to calculate:
+ *
+ * (UNSIGNED_MAX+1) + integer
+ *
+ * Where UNSIGNED_MAX is the appropriate maximum unsigned value, so when the
+ * negative integral value is added the result will be an unsigned value
+ * correspnding to the 2's complement representation.
+ */
+void PNGAPI
+png_save_int_32(png_bytep buf, png_int_32 i)
+{
+ png_save_uint_32(buf, i);
+}
+# endif
+
+# ifdef PNG_TIME_RFC1123_SUPPORTED
+/* Convert the supplied time into an RFC 1123 string suitable for use in
+ * a "Creation Time" or other text-based time string.
+ */
+int PNGAPI
+png_convert_to_rfc1123_buffer(char out[29], png_const_timep ptime)
+{
+ static PNG_CONST char short_months[12][4] =
+ {"Jan", "Feb", "Mar", "Apr", "May", "Jun",
+ "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"};
+
+ if (out == NULL)
+ return 0;
+
+ if (ptime->year > 9999 /* RFC1123 limitation */ ||
+ ptime->month == 0 || ptime->month > 12 ||
+ ptime->day == 0 || ptime->day > 31 ||
+ ptime->hour > 23 || ptime->minute > 59 ||
+ ptime->second > 60)
+ return 0;
+
+ {
+ size_t pos = 0;
+ char number_buf[5]; /* enough for a four-digit year */
+
+# define APPEND_STRING(string) pos = png_safecat(out, 29, pos, (string))
+# define APPEND_NUMBER(format, value)\
+ APPEND_STRING(PNG_FORMAT_NUMBER(number_buf, format, (value)))
+# define APPEND(ch) if (pos < 28) out[pos++] = (ch)
+
+ APPEND_NUMBER(PNG_NUMBER_FORMAT_u, (unsigned)ptime->day);
+ APPEND(' ');
+ APPEND_STRING(short_months[(ptime->month - 1)]);
+ APPEND(' ');
+ APPEND_NUMBER(PNG_NUMBER_FORMAT_u, ptime->year);
+ APPEND(' ');
+ APPEND_NUMBER(PNG_NUMBER_FORMAT_02u, (unsigned)ptime->hour);
+ APPEND(':');
+ APPEND_NUMBER(PNG_NUMBER_FORMAT_02u, (unsigned)ptime->minute);
+ APPEND(':');
+ APPEND_NUMBER(PNG_NUMBER_FORMAT_02u, (unsigned)ptime->second);
+ APPEND_STRING(" +0000"); /* This reliably terminates the buffer */
+ PNG_UNUSED (pos)
+
+# undef APPEND
+# undef APPEND_NUMBER
+# undef APPEND_STRING
+ }
+
+ return 1;
+}
+
+# if PNG_LIBPNG_VER < 10700
+/* To do: remove the following from libpng-1.7 */
+/* Original API that uses a private buffer in png_struct.
+ * Deprecated because it causes png_struct to carry a spurious temporary
+ * buffer (png_struct::time_buffer), better to have the caller pass this in.
+ */
+png_const_charp PNGAPI
+png_convert_to_rfc1123(png_structrp png_ptr, png_const_timep ptime)
+{
+ if (png_ptr != NULL)
+ {
+ /* The only failure above if png_ptr != NULL is from an invalid ptime */
+ if (png_convert_to_rfc1123_buffer(png_ptr->time_buffer, ptime) == 0)
+ png_warning(png_ptr, "Ignoring invalid time value");
+
+ else
+ return png_ptr->time_buffer;
+ }
+
+ return NULL;
+}
+# endif /* LIBPNG_VER < 10700 */
+# endif /* TIME_RFC1123 */
+
+#endif /* READ || WRITE */
+
+png_const_charp PNGAPI
+png_get_copyright(png_const_structrp png_ptr)
+{
+ PNG_UNUSED(png_ptr) /* Silence compiler warning about unused png_ptr */
+#ifdef PNG_STRING_COPYRIGHT
+ return PNG_STRING_COPYRIGHT
+#else
+# ifdef __STDC__
+ return PNG_STRING_NEWLINE \
+ "libpng version 1.6.20 - December 3, 2015" PNG_STRING_NEWLINE \
+ "Copyright (c) 1998-2015 Glenn Randers-Pehrson" PNG_STRING_NEWLINE \
+ "Copyright (c) 1996-1997 Andreas Dilger" PNG_STRING_NEWLINE \
+ "Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc." \
+ PNG_STRING_NEWLINE;
+# else
+ return "libpng version 1.6.20 - December 3, 2015\
+ Copyright (c) 1998-2015 Glenn Randers-Pehrson\
+ Copyright (c) 1996-1997 Andreas Dilger\
+ Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.";
+# endif
+#endif
+}
+
+/* The following return the library version as a short string in the
+ * format 1.0.0 through 99.99.99zz. To get the version of *.h files
+ * used with your application, print out PNG_LIBPNG_VER_STRING, which
+ * is defined in png.h.
+ * Note: now there is no difference between png_get_libpng_ver() and
+ * png_get_header_ver(). Due to the version_nn_nn_nn typedef guard,
+ * it is guaranteed that png.c uses the correct version of png.h.
+ */
+png_const_charp PNGAPI
+png_get_libpng_ver(png_const_structrp png_ptr)
+{
+ /* Version of *.c files used when building libpng */
+ return png_get_header_ver(png_ptr);
+}
+
+png_const_charp PNGAPI
+png_get_header_ver(png_const_structrp png_ptr)
+{
+ /* Version of *.h files used when building libpng */
+ PNG_UNUSED(png_ptr) /* Silence compiler warning about unused png_ptr */
+ return PNG_LIBPNG_VER_STRING;
+}
+
+png_const_charp PNGAPI
+png_get_header_version(png_const_structrp png_ptr)
+{
+ /* Returns longer string containing both version and date */
+ PNG_UNUSED(png_ptr) /* Silence compiler warning about unused png_ptr */
+#ifdef __STDC__
+ return PNG_HEADER_VERSION_STRING
+# ifndef PNG_READ_SUPPORTED
+ " (NO READ SUPPORT)"
+# endif
+ PNG_STRING_NEWLINE;
+#else
+ return PNG_HEADER_VERSION_STRING;
+#endif
+}
+
+#ifdef PNG_BUILD_GRAYSCALE_PALETTE_SUPPORTED
+/* NOTE: this routine is not used internally! */
+/* Build a grayscale palette. Palette is assumed to be 1 << bit_depth
+ * large of png_color. This lets grayscale images be treated as
+ * paletted. Most useful for gamma correction and simplification
+ * of code. This API is not used internally.
+ */
+void PNGAPI
+png_build_grayscale_palette(int bit_depth, png_colorp palette)
+{
+ int num_palette;
+ int color_inc;
+ int i;
+ int v;
+
+ png_debug(1, "in png_do_build_grayscale_palette");
+
+ if (palette == NULL)
+ return;
+
+ switch (bit_depth)
+ {
+ case 1:
+ num_palette = 2;
+ color_inc = 0xff;
+ break;
+
+ case 2:
+ num_palette = 4;
+ color_inc = 0x55;
+ break;
+
+ case 4:
+ num_palette = 16;
+ color_inc = 0x11;
+ break;
+
+ case 8:
+ num_palette = 256;
+ color_inc = 1;
+ break;
+
+ default:
+ num_palette = 0;
+ color_inc = 0;
+ break;
+ }
+
+ for (i = 0, v = 0; i < num_palette; i++, v += color_inc)
+ {
+ palette[i].red = (png_byte)(v & 0xff);
+ palette[i].green = (png_byte)(v & 0xff);
+ palette[i].blue = (png_byte)(v & 0xff);
+ }
+}
+#endif
+
+#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
+int PNGAPI
+png_handle_as_unknown(png_const_structrp png_ptr, png_const_bytep chunk_name)
+{
+ /* Check chunk_name and return "keep" value if it's on the list, else 0 */
+ png_const_bytep p, p_end;
+
+ if (png_ptr == NULL || chunk_name == NULL || png_ptr->num_chunk_list == 0)
+ return PNG_HANDLE_CHUNK_AS_DEFAULT;
+
+ p_end = png_ptr->chunk_list;
+ p = p_end + png_ptr->num_chunk_list*5; /* beyond end */
+
+ /* The code is the fifth byte after each four byte string. Historically this
+ * code was always searched from the end of the list, this is no longer
+ * necessary because the 'set' routine handles duplicate entries correcty.
+ */
+ do /* num_chunk_list > 0, so at least one */
+ {
+ p -= 5;
+
+ if (memcmp(chunk_name, p, 4) == 0)
+ return p[4];
+ }
+ while (p > p_end);
+
+ /* This means that known chunks should be processed and unknown chunks should
+ * be handled according to the value of png_ptr->unknown_default; this can be
+ * confusing because, as a result, there are two levels of defaulting for
+ * unknown chunks.
+ */
+ return PNG_HANDLE_CHUNK_AS_DEFAULT;
+}
+
+#if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED) ||\
+ defined(PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
+int /* PRIVATE */
+png_chunk_unknown_handling(png_const_structrp png_ptr, png_uint_32 chunk_name)
+{
+ png_byte chunk_string[5];
+
+ PNG_CSTRING_FROM_CHUNK(chunk_string, chunk_name);
+ return png_handle_as_unknown(png_ptr, chunk_string);
+}
+#endif /* READ_UNKNOWN_CHUNKS || HANDLE_AS_UNKNOWN */
+#endif /* SET_UNKNOWN_CHUNKS */
+
+#ifdef PNG_READ_SUPPORTED
+/* This function, added to libpng-1.0.6g, is untested. */
+int PNGAPI
+png_reset_zstream(png_structrp png_ptr)
+{
+ if (png_ptr == NULL)
+ return Z_STREAM_ERROR;
+
+ /* WARNING: this resets the window bits to the maximum! */
+ return (inflateReset(&png_ptr->zstream));
+}
+#endif /* READ */
+
+/* This function was added to libpng-1.0.7 */
+png_uint_32 PNGAPI
+png_access_version_number(void)
+{
+ /* Version of *.c files used when building libpng */
+ return((png_uint_32)PNG_LIBPNG_VER);
+}
+
+#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
+/* Ensure that png_ptr->zstream.msg holds some appropriate error message string.
+ * If it doesn't 'ret' is used to set it to something appropriate, even in cases
+ * like Z_OK or Z_STREAM_END where the error code is apparently a success code.
+ */
+void /* PRIVATE */
+png_zstream_error(png_structrp png_ptr, int ret)
+{
+ /* Translate 'ret' into an appropriate error string, priority is given to the
+ * one in zstream if set. This always returns a string, even in cases like
+ * Z_OK or Z_STREAM_END where the error code is a success code.
+ */
+ if (png_ptr->zstream.msg == NULL) switch (ret)
+ {
+ default:
+ case Z_OK:
+ png_ptr->zstream.msg = PNGZ_MSG_CAST("unexpected zlib return code");
+ break;
+
+ case Z_STREAM_END:
+ /* Normal exit */
+ png_ptr->zstream.msg = PNGZ_MSG_CAST("unexpected end of LZ stream");
+ break;
+
+ case Z_NEED_DICT:
+ /* This means the deflate stream did not have a dictionary; this
+ * indicates a bogus PNG.
+ */
+ png_ptr->zstream.msg = PNGZ_MSG_CAST("missing LZ dictionary");
+ break;
+
+ case Z_ERRNO:
+ /* gz APIs only: should not happen */
+ png_ptr->zstream.msg = PNGZ_MSG_CAST("zlib IO error");
+ break;
+
+ case Z_STREAM_ERROR:
+ /* internal libpng error */
+ png_ptr->zstream.msg = PNGZ_MSG_CAST("bad parameters to zlib");
+ break;
+
+ case Z_DATA_ERROR:
+ png_ptr->zstream.msg = PNGZ_MSG_CAST("damaged LZ stream");
+ break;
+
+ case Z_MEM_ERROR:
+ png_ptr->zstream.msg = PNGZ_MSG_CAST("insufficient memory");
+ break;
+
+ case Z_BUF_ERROR:
+ /* End of input or output; not a problem if the caller is doing
+ * incremental read or write.
+ */
+ png_ptr->zstream.msg = PNGZ_MSG_CAST("truncated");
+ break;
+
+ case Z_VERSION_ERROR:
+ png_ptr->zstream.msg = PNGZ_MSG_CAST("unsupported zlib version");
+ break;
+
+ case PNG_UNEXPECTED_ZLIB_RETURN:
+ /* Compile errors here mean that zlib now uses the value co-opted in
+ * pngpriv.h for PNG_UNEXPECTED_ZLIB_RETURN; update the switch above
+ * and change pngpriv.h. Note that this message is "... return",
+ * whereas the default/Z_OK one is "... return code".
+ */
+ png_ptr->zstream.msg = PNGZ_MSG_CAST("unexpected zlib return");
+ break;
+ }
+}
+
+/* png_convert_size: a PNGAPI but no longer in png.h, so deleted
+ * at libpng 1.5.5!
+ */
+
+/* Added at libpng version 1.2.34 and 1.4.0 (moved from pngset.c) */
+#ifdef PNG_GAMMA_SUPPORTED /* always set if COLORSPACE */
+static int
+png_colorspace_check_gamma(png_const_structrp png_ptr,
+ png_colorspacerp colorspace, png_fixed_point gAMA, int from)
+ /* This is called to check a new gamma value against an existing one. The
+ * routine returns false if the new gamma value should not be written.
+ *
+ * 'from' says where the new gamma value comes from:
+ *
+ * 0: the new gamma value is the libpng estimate for an ICC profile
+ * 1: the new gamma value comes from a gAMA chunk
+ * 2: the new gamma value comes from an sRGB chunk
+ */
+{
+ png_fixed_point gtest;
+
+ if ((colorspace->flags & PNG_COLORSPACE_HAVE_GAMMA) != 0 &&
+ (png_muldiv(>est, colorspace->gamma, PNG_FP_1, gAMA) == 0 ||
+ png_gamma_significant(gtest) != 0))
+ {
+ /* Either this is an sRGB image, in which case the calculated gamma
+ * approximation should match, or this is an image with a profile and the
+ * value libpng calculates for the gamma of the profile does not match the
+ * value recorded in the file. The former, sRGB, case is an error, the
+ * latter is just a warning.
+ */
+ if ((colorspace->flags & PNG_COLORSPACE_FROM_sRGB) != 0 || from == 2)
+ {
+ png_chunk_report(png_ptr, "gamma value does not match sRGB",
+ PNG_CHUNK_ERROR);
+ /* Do not overwrite an sRGB value */
+ return from == 2;
+ }
+
+ else /* sRGB tag not involved */
+ {
+ png_chunk_report(png_ptr, "gamma value does not match libpng estimate",
+ PNG_CHUNK_WARNING);
+ return from == 1;
+ }
+ }
+
+ return 1;
+}
+
+void /* PRIVATE */
+png_colorspace_set_gamma(png_const_structrp png_ptr,
+ png_colorspacerp colorspace, png_fixed_point gAMA)
+{
+ /* Changed in libpng-1.5.4 to limit the values to ensure overflow can't
+ * occur. Since the fixed point representation is asymetrical it is
+ * possible for 1/gamma to overflow the limit of 21474 and this means the
+ * gamma value must be at least 5/100000 and hence at most 20000.0. For
+ * safety the limits here are a little narrower. The values are 0.00016 to
+ * 6250.0, which are truly ridiculous gamma values (and will produce
+ * displays that are all black or all white.)
+ *
+ * In 1.6.0 this test replaces the ones in pngrutil.c, in the gAMA chunk
+ * handling code, which only required the value to be >0.
+ */
+ png_const_charp errmsg;
+
+ if (gAMA < 16 || gAMA > 625000000)
+ errmsg = "gamma value out of range";
+
+# ifdef PNG_READ_gAMA_SUPPORTED
+ /* Allow the application to set the gamma value more than once */
+ else if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0 &&
+ (colorspace->flags & PNG_COLORSPACE_FROM_gAMA) != 0)
+ errmsg = "duplicate";
+# endif
+
+ /* Do nothing if the colorspace is already invalid */
+ else if ((colorspace->flags & PNG_COLORSPACE_INVALID) != 0)
+ return;
+
+ else
+ {
+ if (png_colorspace_check_gamma(png_ptr, colorspace, gAMA,
+ 1/*from gAMA*/) != 0)
+ {
+ /* Store this gamma value. */
+ colorspace->gamma = gAMA;
+ colorspace->flags |=
+ (PNG_COLORSPACE_HAVE_GAMMA | PNG_COLORSPACE_FROM_gAMA);
+ }
+
+ /* At present if the check_gamma test fails the gamma of the colorspace is
+ * not updated however the colorspace is not invalidated. This
+ * corresponds to the case where the existing gamma comes from an sRGB
+ * chunk or profile. An error message has already been output.
+ */
+ return;
+ }
+
+ /* Error exit - errmsg has been set. */
+ colorspace->flags |= PNG_COLORSPACE_INVALID;
+ png_chunk_report(png_ptr, errmsg, PNG_CHUNK_WRITE_ERROR);
+}
+
+void /* PRIVATE */
+png_colorspace_sync_info(png_const_structrp png_ptr, png_inforp info_ptr)
+{
+ if ((info_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) != 0)
+ {
+ /* Everything is invalid */
+ info_ptr->valid &= ~(PNG_INFO_gAMA|PNG_INFO_cHRM|PNG_INFO_sRGB|
+ PNG_INFO_iCCP);
+
+# ifdef PNG_COLORSPACE_SUPPORTED
+ /* Clean up the iCCP profile now if it won't be used. */
+ png_free_data(png_ptr, info_ptr, PNG_FREE_ICCP, -1/*not used*/);
+# else
+ PNG_UNUSED(png_ptr)
+# endif
+ }
+
+ else
+ {
+# ifdef PNG_COLORSPACE_SUPPORTED
+ /* Leave the INFO_iCCP flag set if the pngset.c code has already set
+ * it; this allows a PNG to contain a profile which matches sRGB and
+ * yet still have that profile retrievable by the application.
+ */
+ if ((info_ptr->colorspace.flags & PNG_COLORSPACE_MATCHES_sRGB) != 0)
+ info_ptr->valid |= PNG_INFO_sRGB;
+
+ else
+ info_ptr->valid &= ~PNG_INFO_sRGB;
+
+ if ((info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_ENDPOINTS) != 0)
+ info_ptr->valid |= PNG_INFO_cHRM;
+
+ else
+ info_ptr->valid &= ~PNG_INFO_cHRM;
+# endif
+
+ if ((info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_GAMMA) != 0)
+ info_ptr->valid |= PNG_INFO_gAMA;
+
+ else
+ info_ptr->valid &= ~PNG_INFO_gAMA;
+ }
+}
+
+#ifdef PNG_READ_SUPPORTED
+void /* PRIVATE */
+png_colorspace_sync(png_const_structrp png_ptr, png_inforp info_ptr)
+{
+ if (info_ptr == NULL) /* reduce code size; check here not in the caller */
+ return;
+
+ info_ptr->colorspace = png_ptr->colorspace;
+ png_colorspace_sync_info(png_ptr, info_ptr);
+}
+#endif
+#endif /* GAMMA */
+
+#ifdef PNG_COLORSPACE_SUPPORTED
+/* Added at libpng-1.5.5 to support read and write of true CIEXYZ values for
+ * cHRM, as opposed to using chromaticities. These internal APIs return
+ * non-zero on a parameter error. The X, Y and Z values are required to be
+ * positive and less than 1.0.
+ */
+static int
+png_xy_from_XYZ(png_xy *xy, const png_XYZ *XYZ)
+{
+ png_int_32 d, dwhite, whiteX, whiteY;
+
+ d = XYZ->red_X + XYZ->red_Y + XYZ->red_Z;
+ if (png_muldiv(&xy->redx, XYZ->red_X, PNG_FP_1, d) == 0)
+ return 1;
+ if (png_muldiv(&xy->redy, XYZ->red_Y, PNG_FP_1, d) == 0)
+ return 1;
+ dwhite = d;
+ whiteX = XYZ->red_X;
+ whiteY = XYZ->red_Y;
+
+ d = XYZ->green_X + XYZ->green_Y + XYZ->green_Z;
+ if (png_muldiv(&xy->greenx, XYZ->green_X, PNG_FP_1, d) == 0)
+ return 1;
+ if (png_muldiv(&xy->greeny, XYZ->green_Y, PNG_FP_1, d) == 0)
+ return 1;
+ dwhite += d;
+ whiteX += XYZ->green_X;
+ whiteY += XYZ->green_Y;
+
+ d = XYZ->blue_X + XYZ->blue_Y + XYZ->blue_Z;
+ if (png_muldiv(&xy->bluex, XYZ->blue_X, PNG_FP_1, d) == 0)
+ return 1;
+ if (png_muldiv(&xy->bluey, XYZ->blue_Y, PNG_FP_1, d) == 0)
+ return 1;
+ dwhite += d;
+ whiteX += XYZ->blue_X;
+ whiteY += XYZ->blue_Y;
+
+ /* The reference white is simply the sum of the end-point (X,Y,Z) vectors,
+ * thus:
+ */
+ if (png_muldiv(&xy->whitex, whiteX, PNG_FP_1, dwhite) == 0)
+ return 1;
+ if (png_muldiv(&xy->whitey, whiteY, PNG_FP_1, dwhite) == 0)
+ return 1;
+
+ return 0;
+}
+
+static int
+png_XYZ_from_xy(png_XYZ *XYZ, const png_xy *xy)
+{
+ png_fixed_point red_inverse, green_inverse, blue_scale;
+ png_fixed_point left, right, denominator;
+
+ /* Check xy and, implicitly, z. Note that wide gamut color spaces typically
+ * have end points with 0 tristimulus values (these are impossible end
+ * points, but they are used to cover the possible colors). We check
+ * xy->whitey against 5, not 0, to avoid a possible integer overflow.
+ */
+ if (xy->redx < 0 || xy->redx > PNG_FP_1) return 1;
+ if (xy->redy < 0 || xy->redy > PNG_FP_1-xy->redx) return 1;
+ if (xy->greenx < 0 || xy->greenx > PNG_FP_1) return 1;
+ if (xy->greeny < 0 || xy->greeny > PNG_FP_1-xy->greenx) return 1;
+ if (xy->bluex < 0 || xy->bluex > PNG_FP_1) return 1;
+ if (xy->bluey < 0 || xy->bluey > PNG_FP_1-xy->bluex) return 1;
+ if (xy->whitex < 0 || xy->whitex > PNG_FP_1) return 1;
+ if (xy->whitey < 5 || xy->whitey > PNG_FP_1-xy->whitex) return 1;
+
+ /* The reverse calculation is more difficult because the original tristimulus
+ * value had 9 independent values (red,green,blue)x(X,Y,Z) however only 8
+ * derived values were recorded in the cHRM chunk;
+ * (red,green,blue,white)x(x,y). This loses one degree of freedom and
+ * therefore an arbitrary ninth value has to be introduced to undo the
+ * original transformations.
+ *
+ * Think of the original end-points as points in (X,Y,Z) space. The
+ * chromaticity values (c) have the property:
+ *
+ * C
+ * c = ---------
+ * X + Y + Z
+ *
+ * For each c (x,y,z) from the corresponding original C (X,Y,Z). Thus the
+ * three chromaticity values (x,y,z) for each end-point obey the
+ * relationship:
+ *
+ * x + y + z = 1
+ *
+ * This describes the plane in (X,Y,Z) space that intersects each axis at the
+ * value 1.0; call this the chromaticity plane. Thus the chromaticity
+ * calculation has scaled each end-point so that it is on the x+y+z=1 plane
+ * and chromaticity is the intersection of the vector from the origin to the
+ * (X,Y,Z) value with the chromaticity plane.
+ *
+ * To fully invert the chromaticity calculation we would need the three
+ * end-point scale factors, (red-scale, green-scale, blue-scale), but these
+ * were not recorded. Instead we calculated the reference white (X,Y,Z) and
+ * recorded the chromaticity of this. The reference white (X,Y,Z) would have
+ * given all three of the scale factors since:
+ *
+ * color-C = color-c * color-scale
+ * white-C = red-C + green-C + blue-C
+ * = red-c*red-scale + green-c*green-scale + blue-c*blue-scale
+ *
+ * But cHRM records only white-x and white-y, so we have lost the white scale
+ * factor:
+ *
+ * white-C = white-c*white-scale
+ *
+ * To handle this the inverse transformation makes an arbitrary assumption
+ * about white-scale:
+ *
+ * Assume: white-Y = 1.0
+ * Hence: white-scale = 1/white-y
+ * Or: red-Y + green-Y + blue-Y = 1.0
+ *
+ * Notice the last statement of the assumption gives an equation in three of
+ * the nine values we want to calculate. 8 more equations come from the
+ * above routine as summarised at the top above (the chromaticity
+ * calculation):
+ *
+ * Given: color-x = color-X / (color-X + color-Y + color-Z)
+ * Hence: (color-x - 1)*color-X + color.x*color-Y + color.x*color-Z = 0
+ *
+ * This is 9 simultaneous equations in the 9 variables "color-C" and can be
+ * solved by Cramer's rule. Cramer's rule requires calculating 10 9x9 matrix
+ * determinants, however this is not as bad as it seems because only 28 of
+ * the total of 90 terms in the various matrices are non-zero. Nevertheless
+ * Cramer's rule is notoriously numerically unstable because the determinant
+ * calculation involves the difference of large, but similar, numbers. It is
+ * difficult to be sure that the calculation is stable for real world values
+ * and it is certain that it becomes unstable where the end points are close
+ * together.
+ *
+ * So this code uses the perhaps slightly less optimal but more
+ * understandable and totally obvious approach of calculating color-scale.
+ *
+ * This algorithm depends on the precision in white-scale and that is
+ * (1/white-y), so we can immediately see that as white-y approaches 0 the
+ * accuracy inherent in the cHRM chunk drops off substantially.
+ *
+ * libpng arithmetic: a simple inversion of the above equations
+ * ------------------------------------------------------------
+ *
+ * white_scale = 1/white-y
+ * white-X = white-x * white-scale
+ * white-Y = 1.0
+ * white-Z = (1 - white-x - white-y) * white_scale
+ *
+ * white-C = red-C + green-C + blue-C
+ * = red-c*red-scale + green-c*green-scale + blue-c*blue-scale
+ *
+ * This gives us three equations in (red-scale,green-scale,blue-scale) where
+ * all the coefficients are now known:
+ *
+ * red-x*red-scale + green-x*green-scale + blue-x*blue-scale
+ * = white-x/white-y
+ * red-y*red-scale + green-y*green-scale + blue-y*blue-scale = 1
+ * red-z*red-scale + green-z*green-scale + blue-z*blue-scale
+ * = (1 - white-x - white-y)/white-y
+ *
+ * In the last equation color-z is (1 - color-x - color-y) so we can add all
+ * three equations together to get an alternative third:
+ *
+ * red-scale + green-scale + blue-scale = 1/white-y = white-scale
+ *
+ * So now we have a Cramer's rule solution where the determinants are just
+ * 3x3 - far more tractible. Unfortunately 3x3 determinants still involve
+ * multiplication of three coefficients so we can't guarantee to avoid
+ * overflow in the libpng fixed point representation. Using Cramer's rule in
+ * floating point is probably a good choice here, but it's not an option for
+ * fixed point. Instead proceed to simplify the first two equations by
+ * eliminating what is likely to be the largest value, blue-scale:
+ *
+ * blue-scale = white-scale - red-scale - green-scale
+ *
+ * Hence:
+ *
+ * (red-x - blue-x)*red-scale + (green-x - blue-x)*green-scale =
+ * (white-x - blue-x)*white-scale
+ *
+ * (red-y - blue-y)*red-scale + (green-y - blue-y)*green-scale =
+ * 1 - blue-y*white-scale
+ *
+ * And now we can trivially solve for (red-scale,green-scale):
+ *
+ * green-scale =
+ * (white-x - blue-x)*white-scale - (red-x - blue-x)*red-scale
+ * -----------------------------------------------------------
+ * green-x - blue-x
+ *
+ * red-scale =
+ * 1 - blue-y*white-scale - (green-y - blue-y) * green-scale
+ * ---------------------------------------------------------
+ * red-y - blue-y
+ *
+ * Hence:
+ *
+ * red-scale =
+ * ( (green-x - blue-x) * (white-y - blue-y) -
+ * (green-y - blue-y) * (white-x - blue-x) ) / white-y
+ * -------------------------------------------------------------------------
+ * (green-x - blue-x)*(red-y - blue-y)-(green-y - blue-y)*(red-x - blue-x)
+ *
+ * green-scale =
+ * ( (red-y - blue-y) * (white-x - blue-x) -
+ * (red-x - blue-x) * (white-y - blue-y) ) / white-y
+ * -------------------------------------------------------------------------
+ * (green-x - blue-x)*(red-y - blue-y)-(green-y - blue-y)*(red-x - blue-x)
+ *
+ * Accuracy:
+ * The input values have 5 decimal digits of accuracy. The values are all in
+ * the range 0 < value < 1, so simple products are in the same range but may
+ * need up to 10 decimal digits to preserve the original precision and avoid
+ * underflow. Because we are using a 32-bit signed representation we cannot
+ * match this; the best is a little over 9 decimal digits, less than 10.
+ *
+ * The approach used here is to preserve the maximum precision within the
+ * signed representation. Because the red-scale calculation above uses the
+ * difference between two products of values that must be in the range -1..+1
+ * it is sufficient to divide the product by 7; ceil(100,000/32767*2). The
+ * factor is irrelevant in the calculation because it is applied to both
+ * numerator and denominator.
+ *
+ * Note that the values of the differences of the products of the
+ * chromaticities in the above equations tend to be small, for example for
+ * the sRGB chromaticities they are:
+ *
+ * red numerator: -0.04751
+ * green numerator: -0.08788
+ * denominator: -0.2241 (without white-y multiplication)
+ *
+ * The resultant Y coefficients from the chromaticities of some widely used
+ * color space definitions are (to 15 decimal places):
+ *
+ * sRGB
+ * 0.212639005871510 0.715168678767756 0.072192315360734
+ * Kodak ProPhoto
+ * 0.288071128229293 0.711843217810102 0.000085653960605
+ * Adobe RGB
+ * 0.297344975250536 0.627363566255466 0.075291458493998
+ * Adobe Wide Gamut RGB
+ * 0.258728243040113 0.724682314948566 0.016589442011321
+ */
+ /* By the argument, above overflow should be impossible here. The return
+ * value of 2 indicates an internal error to the caller.
+ */
+ if (png_muldiv(&left, xy->greenx-xy->bluex, xy->redy - xy->bluey, 7) == 0)
+ return 2;
+ if (png_muldiv(&right, xy->greeny-xy->bluey, xy->redx - xy->bluex, 7) == 0)
+ return 2;
+ denominator = left - right;
+
+ /* Now find the red numerator. */
+ if (png_muldiv(&left, xy->greenx-xy->bluex, xy->whitey-xy->bluey, 7) == 0)
+ return 2;
+ if (png_muldiv(&right, xy->greeny-xy->bluey, xy->whitex-xy->bluex, 7) == 0)
+ return 2;
+
+ /* Overflow is possible here and it indicates an extreme set of PNG cHRM
+ * chunk values. This calculation actually returns the reciprocal of the
+ * scale value because this allows us to delay the multiplication of white-y
+ * into the denominator, which tends to produce a small number.
+ */
+ if (png_muldiv(&red_inverse, xy->whitey, denominator, left-right) == 0 ||
+ red_inverse <= xy->whitey /* r+g+b scales = white scale */)
+ return 1;
+
+ /* Similarly for green_inverse: */
+ if (png_muldiv(&left, xy->redy-xy->bluey, xy->whitex-xy->bluex, 7) == 0)
+ return 2;
+ if (png_muldiv(&right, xy->redx-xy->bluex, xy->whitey-xy->bluey, 7) == 0)
+ return 2;
+ if (png_muldiv(&green_inverse, xy->whitey, denominator, left-right) == 0 ||
+ green_inverse <= xy->whitey)
+ return 1;
+
+ /* And the blue scale, the checks above guarantee this can't overflow but it
+ * can still produce 0 for extreme cHRM values.
+ */
+ blue_scale = png_reciprocal(xy->whitey) - png_reciprocal(red_inverse) -
+ png_reciprocal(green_inverse);
+ if (blue_scale <= 0)
+ return 1;
+
+
+ /* And fill in the png_XYZ: */
+ if (png_muldiv(&XYZ->red_X, xy->redx, PNG_FP_1, red_inverse) == 0)
+ return 1;
+ if (png_muldiv(&XYZ->red_Y, xy->redy, PNG_FP_1, red_inverse) == 0)
+ return 1;
+ if (png_muldiv(&XYZ->red_Z, PNG_FP_1 - xy->redx - xy->redy, PNG_FP_1,
+ red_inverse) == 0)
+ return 1;
+
+ if (png_muldiv(&XYZ->green_X, xy->greenx, PNG_FP_1, green_inverse) == 0)
+ return 1;
+ if (png_muldiv(&XYZ->green_Y, xy->greeny, PNG_FP_1, green_inverse) == 0)
+ return 1;
+ if (png_muldiv(&XYZ->green_Z, PNG_FP_1 - xy->greenx - xy->greeny, PNG_FP_1,
+ green_inverse) == 0)
+ return 1;
+
+ if (png_muldiv(&XYZ->blue_X, xy->bluex, blue_scale, PNG_FP_1) == 0)
+ return 1;
+ if (png_muldiv(&XYZ->blue_Y, xy->bluey, blue_scale, PNG_FP_1) == 0)
+ return 1;
+ if (png_muldiv(&XYZ->blue_Z, PNG_FP_1 - xy->bluex - xy->bluey, blue_scale,
+ PNG_FP_1) == 0)
+ return 1;
+
+ return 0; /*success*/
+}
+
+static int
+png_XYZ_normalize(png_XYZ *XYZ)
+{
+ png_int_32 Y;
+
+ if (XYZ->red_Y < 0 || XYZ->green_Y < 0 || XYZ->blue_Y < 0 ||
+ XYZ->red_X < 0 || XYZ->green_X < 0 || XYZ->blue_X < 0 ||
+ XYZ->red_Z < 0 || XYZ->green_Z < 0 || XYZ->blue_Z < 0)
+ return 1;
+
+ /* Normalize by scaling so the sum of the end-point Y values is PNG_FP_1.
+ * IMPLEMENTATION NOTE: ANSI requires signed overflow not to occur, therefore
+ * relying on addition of two positive values producing a negative one is not
+ * safe.
+ */
+ Y = XYZ->red_Y;
+ if (0x7fffffff - Y < XYZ->green_X)
+ return 1;
+ Y += XYZ->green_Y;
+ if (0x7fffffff - Y < XYZ->blue_X)
+ return 1;
+ Y += XYZ->blue_Y;
+
+ if (Y != PNG_FP_1)
+ {
+ if (png_muldiv(&XYZ->red_X, XYZ->red_X, PNG_FP_1, Y) == 0)
+ return 1;
+ if (png_muldiv(&XYZ->red_Y, XYZ->red_Y, PNG_FP_1, Y) == 0)
+ return 1;
+ if (png_muldiv(&XYZ->red_Z, XYZ->red_Z, PNG_FP_1, Y) == 0)
+ return 1;
+
+ if (png_muldiv(&XYZ->green_X, XYZ->green_X, PNG_FP_1, Y) == 0)
+ return 1;
+ if (png_muldiv(&XYZ->green_Y, XYZ->green_Y, PNG_FP_1, Y) == 0)
+ return 1;
+ if (png_muldiv(&XYZ->green_Z, XYZ->green_Z, PNG_FP_1, Y) == 0)
+ return 1;
+
+ if (png_muldiv(&XYZ->blue_X, XYZ->blue_X, PNG_FP_1, Y) == 0)
+ return 1;
+ if (png_muldiv(&XYZ->blue_Y, XYZ->blue_Y, PNG_FP_1, Y) == 0)
+ return 1;
+ if (png_muldiv(&XYZ->blue_Z, XYZ->blue_Z, PNG_FP_1, Y) == 0)
+ return 1;
+ }
+
+ return 0;
+}
+
+static int
+png_colorspace_endpoints_match(const png_xy *xy1, const png_xy *xy2, int delta)
+{
+ /* Allow an error of +/-0.01 (absolute value) on each chromaticity */
+ if (PNG_OUT_OF_RANGE(xy1->whitex, xy2->whitex,delta) ||
+ PNG_OUT_OF_RANGE(xy1->whitey, xy2->whitey,delta) ||
+ PNG_OUT_OF_RANGE(xy1->redx, xy2->redx, delta) ||
+ PNG_OUT_OF_RANGE(xy1->redy, xy2->redy, delta) ||
+ PNG_OUT_OF_RANGE(xy1->greenx, xy2->greenx,delta) ||
+ PNG_OUT_OF_RANGE(xy1->greeny, xy2->greeny,delta) ||
+ PNG_OUT_OF_RANGE(xy1->bluex, xy2->bluex, delta) ||
+ PNG_OUT_OF_RANGE(xy1->bluey, xy2->bluey, delta))
+ return 0;
+ return 1;
+}
+
+/* Added in libpng-1.6.0, a different check for the validity of a set of cHRM
+ * chunk chromaticities. Earlier checks used to simply look for the overflow
+ * condition (where the determinant of the matrix to solve for XYZ ends up zero
+ * because the chromaticity values are not all distinct.) Despite this it is
+ * theoretically possible to produce chromaticities that are apparently valid
+ * but that rapidly degrade to invalid, potentially crashing, sets because of
+ * arithmetic inaccuracies when calculations are performed on them. The new
+ * check is to round-trip xy -> XYZ -> xy and then check that the result is
+ * within a small percentage of the original.
+ */
+static int
+png_colorspace_check_xy(png_XYZ *XYZ, const png_xy *xy)
+{
+ int result;
+ png_xy xy_test;
+
+ /* As a side-effect this routine also returns the XYZ endpoints. */
+ result = png_XYZ_from_xy(XYZ, xy);
+ if (result != 0)
+ return result;
+
+ result = png_xy_from_XYZ(&xy_test, XYZ);
+ if (result != 0)
+ return result;
+
+ if (png_colorspace_endpoints_match(xy, &xy_test,
+ 5/*actually, the math is pretty accurate*/) != 0)
+ return 0;
+
+ /* Too much slip */
+ return 1;
+}
+
+/* This is the check going the other way. The XYZ is modified to normalize it
+ * (another side-effect) and the xy chromaticities are returned.
+ */
+static int
+png_colorspace_check_XYZ(png_xy *xy, png_XYZ *XYZ)
+{
+ int result;
+ png_XYZ XYZtemp;
+
+ result = png_XYZ_normalize(XYZ);
+ if (result != 0)
+ return result;
+
+ result = png_xy_from_XYZ(xy, XYZ);
+ if (result != 0)
+ return result;
+
+ XYZtemp = *XYZ;
+ return png_colorspace_check_xy(&XYZtemp, xy);
+}
+
+/* Used to check for an endpoint match against sRGB */
+static const png_xy sRGB_xy = /* From ITU-R BT.709-3 */
+{
+ /* color x y */
+ /* red */ 64000, 33000,
+ /* green */ 30000, 60000,
+ /* blue */ 15000, 6000,
+ /* white */ 31270, 32900
+};
+
+static int
+png_colorspace_set_xy_and_XYZ(png_const_structrp png_ptr,
+ png_colorspacerp colorspace, const png_xy *xy, const png_XYZ *XYZ,
+ int preferred)
+{
+ if ((colorspace->flags & PNG_COLORSPACE_INVALID) != 0)
+ return 0;
+
+ /* The consistency check is performed on the chromaticities; this factors out
+ * variations because of the normalization (or not) of the end point Y
+ * values.
+ */
+ if (preferred < 2 &&
+ (colorspace->flags & PNG_COLORSPACE_HAVE_ENDPOINTS) != 0)
+ {
+ /* The end points must be reasonably close to any we already have. The
+ * following allows an error of up to +/-.001
+ */
+ if (png_colorspace_endpoints_match(xy, &colorspace->end_points_xy,
+ 100) == 0)
+ {
+ colorspace->flags |= PNG_COLORSPACE_INVALID;
+ png_benign_error(png_ptr, "inconsistent chromaticities");
+ return 0; /* failed */
+ }
+
+ /* Only overwrite with preferred values */
+ if (preferred == 0)
+ return 1; /* ok, but no change */
+ }
+
+ colorspace->end_points_xy = *xy;
+ colorspace->end_points_XYZ = *XYZ;
+ colorspace->flags |= PNG_COLORSPACE_HAVE_ENDPOINTS;
+
+ /* The end points are normally quoted to two decimal digits, so allow +/-0.01
+ * on this test.
+ */
+ if (png_colorspace_endpoints_match(xy, &sRGB_xy, 1000) != 0)
+ colorspace->flags |= PNG_COLORSPACE_ENDPOINTS_MATCH_sRGB;
+
+ else
+ colorspace->flags &= PNG_COLORSPACE_CANCEL(
+ PNG_COLORSPACE_ENDPOINTS_MATCH_sRGB);
+
+ return 2; /* ok and changed */
+}
+
+int /* PRIVATE */
+png_colorspace_set_chromaticities(png_const_structrp png_ptr,
+ png_colorspacerp colorspace, const png_xy *xy, int preferred)
+{
+ /* We must check the end points to ensure they are reasonable - in the past
+ * color management systems have crashed as a result of getting bogus
+ * colorant values, while this isn't the fault of libpng it is the
+ * responsibility of libpng because PNG carries the bomb and libpng is in a
+ * position to protect against it.
+ */
+ png_XYZ XYZ;
+
+ switch (png_colorspace_check_xy(&XYZ, xy))
+ {
+ case 0: /* success */
+ return png_colorspace_set_xy_and_XYZ(png_ptr, colorspace, xy, &XYZ,
+ preferred);
+
+ case 1:
+ /* We can't invert the chromaticities so we can't produce value XYZ
+ * values. Likely as not a color management system will fail too.
+ */
+ colorspace->flags |= PNG_COLORSPACE_INVALID;
+ png_benign_error(png_ptr, "invalid chromaticities");
+ break;
+
+ default:
+ /* libpng is broken; this should be a warning but if it happens we
+ * want error reports so for the moment it is an error.
+ */
+ colorspace->flags |= PNG_COLORSPACE_INVALID;
+ png_error(png_ptr, "internal error checking chromaticities");
+ }
+
+ return 0; /* failed */
+}
+
+int /* PRIVATE */
+png_colorspace_set_endpoints(png_const_structrp png_ptr,
+ png_colorspacerp colorspace, const png_XYZ *XYZ_in, int preferred)
+{
+ png_XYZ XYZ = *XYZ_in;
+ png_xy xy;
+
+ switch (png_colorspace_check_XYZ(&xy, &XYZ))
+ {
+ case 0:
+ return png_colorspace_set_xy_and_XYZ(png_ptr, colorspace, &xy, &XYZ,
+ preferred);
+
+ case 1:
+ /* End points are invalid. */
+ colorspace->flags |= PNG_COLORSPACE_INVALID;
+ png_benign_error(png_ptr, "invalid end points");
+ break;
+
+ default:
+ colorspace->flags |= PNG_COLORSPACE_INVALID;
+ png_error(png_ptr, "internal error checking chromaticities");
+ }
+
+ return 0; /* failed */
+}
+
+#if defined(PNG_sRGB_SUPPORTED) || defined(PNG_iCCP_SUPPORTED)
+/* Error message generation */
+static char
+png_icc_tag_char(png_uint_32 byte)
+{
+ byte &= 0xff;
+ if (byte >= 32 && byte <= 126)
+ return (char)byte;
+ else
+ return '?';
+}
+
+static void
+png_icc_tag_name(char *name, png_uint_32 tag)
+{
+ name[0] = '\'';
+ name[1] = png_icc_tag_char(tag >> 24);
+ name[2] = png_icc_tag_char(tag >> 16);
+ name[3] = png_icc_tag_char(tag >> 8);
+ name[4] = png_icc_tag_char(tag );
+ name[5] = '\'';
+}
+
+static int
+is_ICC_signature_char(png_alloc_size_t it)
+{
+ return it == 32 || (it >= 48 && it <= 57) || (it >= 65 && it <= 90) ||
+ (it >= 97 && it <= 122);
+}
+
+static int
+is_ICC_signature(png_alloc_size_t it)
+{
+ return is_ICC_signature_char(it >> 24) /* checks all the top bits */ &&
+ is_ICC_signature_char((it >> 16) & 0xff) &&
+ is_ICC_signature_char((it >> 8) & 0xff) &&
+ is_ICC_signature_char(it & 0xff);
+}
+
+static int
+png_icc_profile_error(png_const_structrp png_ptr, png_colorspacerp colorspace,
+ png_const_charp name, png_alloc_size_t value, png_const_charp reason)
+{
+ size_t pos;
+ char message[196]; /* see below for calculation */
+
+ if (colorspace != NULL)
+ colorspace->flags |= PNG_COLORSPACE_INVALID;
+
+ pos = png_safecat(message, (sizeof message), 0, "profile '"); /* 9 chars */
+ pos = png_safecat(message, pos+79, pos, name); /* Truncate to 79 chars */
+ pos = png_safecat(message, (sizeof message), pos, "': "); /* +2 = 90 */
+ if (is_ICC_signature(value) != 0)
+ {
+ /* So 'value' is at most 4 bytes and the following cast is safe */
+ png_icc_tag_name(message+pos, (png_uint_32)value);
+ pos += 6; /* total +8; less than the else clause */
+ message[pos++] = ':';
+ message[pos++] = ' ';
+ }
+# ifdef PNG_WARNINGS_SUPPORTED
+ else
+ {
+ char number[PNG_NUMBER_BUFFER_SIZE]; /* +24 = 114*/
+
+ pos = png_safecat(message, (sizeof message), pos,
+ png_format_number(number, number+(sizeof number),
+ PNG_NUMBER_FORMAT_x, value));
+ pos = png_safecat(message, (sizeof message), pos, "h: "); /*+2 = 116*/
+ }
+# endif
+ /* The 'reason' is an arbitrary message, allow +79 maximum 195 */
+ pos = png_safecat(message, (sizeof message), pos, reason);
+ PNG_UNUSED(pos)
+
+ /* This is recoverable, but make it unconditionally an app_error on write to
+ * avoid writing invalid ICC profiles into PNG files (i.e., we handle them
+ * on read, with a warning, but on write unless the app turns off
+ * application errors the PNG won't be written.)
+ */
+ png_chunk_report(png_ptr, message,
+ (colorspace != NULL) ? PNG_CHUNK_ERROR : PNG_CHUNK_WRITE_ERROR);
+
+ return 0;
+}
+#endif /* sRGB || iCCP */
+
+#ifdef PNG_sRGB_SUPPORTED
+int /* PRIVATE */
+png_colorspace_set_sRGB(png_const_structrp png_ptr, png_colorspacerp colorspace,
+ int intent)
+{
+ /* sRGB sets known gamma, end points and (from the chunk) intent. */
+ /* IMPORTANT: these are not necessarily the values found in an ICC profile
+ * because ICC profiles store values adapted to a D50 environment; it is
+ * expected that the ICC profile mediaWhitePointTag will be D50; see the
+ * checks and code elsewhere to understand this better.
+ *
+ * These XYZ values, which are accurate to 5dp, produce rgb to gray
+ * coefficients of (6968,23435,2366), which are reduced (because they add up
+ * to 32769 not 32768) to (6968,23434,2366). These are the values that
+ * libpng has traditionally used (and are the best values given the 15bit
+ * algorithm used by the rgb to gray code.)
+ */
+ static const png_XYZ sRGB_XYZ = /* D65 XYZ (*not* the D50 adapted values!) */
+ {
+ /* color X Y Z */
+ /* red */ 41239, 21264, 1933,
+ /* green */ 35758, 71517, 11919,
+ /* blue */ 18048, 7219, 95053
+ };
+
+ /* Do nothing if the colorspace is already invalidated. */
+ if ((colorspace->flags & PNG_COLORSPACE_INVALID) != 0)
+ return 0;
+
+ /* Check the intent, then check for existing settings. It is valid for the
+ * PNG file to have cHRM or gAMA chunks along with sRGB, but the values must
+ * be consistent with the correct values. If, however, this function is
+ * called below because an iCCP chunk matches sRGB then it is quite
+ * conceivable that an older app recorded incorrect gAMA and cHRM because of
+ * an incorrect calculation based on the values in the profile - this does
+ * *not* invalidate the profile (though it still produces an error, which can
+ * be ignored.)
+ */
+ if (intent < 0 || intent >= PNG_sRGB_INTENT_LAST)
+ return png_icc_profile_error(png_ptr, colorspace, "sRGB",
+ (unsigned)intent, "invalid sRGB rendering intent");
+
+ if ((colorspace->flags & PNG_COLORSPACE_HAVE_INTENT) != 0 &&
+ colorspace->rendering_intent != intent)
+ return png_icc_profile_error(png_ptr, colorspace, "sRGB",
+ (unsigned)intent, "inconsistent rendering intents");
+
+ if ((colorspace->flags & PNG_COLORSPACE_FROM_sRGB) != 0)
+ {
+ png_benign_error(png_ptr, "duplicate sRGB information ignored");
+ return 0;
+ }
+
+ /* If the standard sRGB cHRM chunk does not match the one from the PNG file
+ * warn but overwrite the value with the correct one.
+ */
+ if ((colorspace->flags & PNG_COLORSPACE_HAVE_ENDPOINTS) != 0 &&
+ !png_colorspace_endpoints_match(&sRGB_xy, &colorspace->end_points_xy,
+ 100))
+ png_chunk_report(png_ptr, "cHRM chunk does not match sRGB",
+ PNG_CHUNK_ERROR);
+
+ /* This check is just done for the error reporting - the routine always
+ * returns true when the 'from' argument corresponds to sRGB (2).
+ */
+ (void)png_colorspace_check_gamma(png_ptr, colorspace, PNG_GAMMA_sRGB_INVERSE,
+ 2/*from sRGB*/);
+
+ /* intent: bugs in GCC force 'int' to be used as the parameter type. */
+ colorspace->rendering_intent = (png_uint_16)intent;
+ colorspace->flags |= PNG_COLORSPACE_HAVE_INTENT;
+
+ /* endpoints */
+ colorspace->end_points_xy = sRGB_xy;
+ colorspace->end_points_XYZ = sRGB_XYZ;
+ colorspace->flags |=
+ (PNG_COLORSPACE_HAVE_ENDPOINTS|PNG_COLORSPACE_ENDPOINTS_MATCH_sRGB);
+
+ /* gamma */
+ colorspace->gamma = PNG_GAMMA_sRGB_INVERSE;
+ colorspace->flags |= PNG_COLORSPACE_HAVE_GAMMA;
+
+ /* Finally record that we have an sRGB profile */
+ colorspace->flags |=
+ (PNG_COLORSPACE_MATCHES_sRGB|PNG_COLORSPACE_FROM_sRGB);
+
+ return 1; /* set */
+}
+#endif /* sRGB */
+
+#ifdef PNG_iCCP_SUPPORTED
+/* Encoded value of D50 as an ICC XYZNumber. From the ICC 2010 spec the value
+ * is XYZ(0.9642,1.0,0.8249), which scales to:
+ *
+ * (63189.8112, 65536, 54060.6464)
+ */
+static const png_byte D50_nCIEXYZ[12] =
+ { 0x00, 0x00, 0xf6, 0xd6, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0xd3, 0x2d };
+
+int /* PRIVATE */
+png_icc_check_length(png_const_structrp png_ptr, png_colorspacerp colorspace,
+ png_const_charp name, png_uint_32 profile_length)
+{
+ if (profile_length < 132)
+ return png_icc_profile_error(png_ptr, colorspace, name, profile_length,
+ "too short");
+
+ return 1;
+}
+
+int /* PRIVATE */
+png_icc_check_header(png_const_structrp png_ptr, png_colorspacerp colorspace,
+ png_const_charp name, png_uint_32 profile_length,
+ png_const_bytep profile/* first 132 bytes only */, int color_type)
+{
+ png_uint_32 temp;
+
+ /* Length check; this cannot be ignored in this code because profile_length
+ * is used later to check the tag table, so even if the profile seems over
+ * long profile_length from the caller must be correct. The caller can fix
+ * this up on read or write by just passing in the profile header length.
+ */
+ temp = png_get_uint_32(profile);
+ if (temp != profile_length)
+ return png_icc_profile_error(png_ptr, colorspace, name, temp,
+ "length does not match profile");
+
+ temp = (png_uint_32) (*(profile+8));
+ if (temp > 3 && (profile_length & 3))
+ return png_icc_profile_error(png_ptr, colorspace, name, profile_length,
+ "invalid length");
+
+ temp = png_get_uint_32(profile+128); /* tag count: 12 bytes/tag */
+ if (temp > 357913930 || /* (2^32-4-132)/12: maximum possible tag count */
+ profile_length < 132+12*temp) /* truncated tag table */
+ return png_icc_profile_error(png_ptr, colorspace, name, temp,
+ "tag count too large");
+
+ /* The 'intent' must be valid or we can't store it, ICC limits the intent to
+ * 16 bits.
+ */
+ temp = png_get_uint_32(profile+64);
+ if (temp >= 0xffff) /* The ICC limit */
+ return png_icc_profile_error(png_ptr, colorspace, name, temp,
+ "invalid rendering intent");
+
+ /* This is just a warning because the profile may be valid in future
+ * versions.
+ */
+ if (temp >= PNG_sRGB_INTENT_LAST)
+ (void)png_icc_profile_error(png_ptr, NULL, name, temp,
+ "intent outside defined range");
+
+ /* At this point the tag table can't be checked because it hasn't necessarily
+ * been loaded; however, various header fields can be checked. These checks
+ * are for values permitted by the PNG spec in an ICC profile; the PNG spec
+ * restricts the profiles that can be passed in an iCCP chunk (they must be
+ * appropriate to processing PNG data!)
+ */
+
+ /* Data checks (could be skipped). These checks must be independent of the
+ * version number; however, the version number doesn't accomodate changes in
+ * the header fields (just the known tags and the interpretation of the
+ * data.)
+ */
+ temp = png_get_uint_32(profile+36); /* signature 'ascp' */
+ if (temp != 0x61637370)
+ return png_icc_profile_error(png_ptr, colorspace, name, temp,
+ "invalid signature");
+
+ /* Currently the PCS illuminant/adopted white point (the computational
+ * white point) are required to be D50,
+ * however the profile contains a record of the illuminant so perhaps ICC
+ * expects to be able to change this in the future (despite the rationale in
+ * the introduction for using a fixed PCS adopted white.) Consequently the
+ * following is just a warning.
+ */
+ if (memcmp(profile+68, D50_nCIEXYZ, 12) != 0)
+ (void)png_icc_profile_error(png_ptr, NULL, name, 0/*no tag value*/,
+ "PCS illuminant is not D50");
+
+ /* The PNG spec requires this:
+ * "If the iCCP chunk is present, the image samples conform to the colour
+ * space represented by the embedded ICC profile as defined by the
+ * International Color Consortium [ICC]. The colour space of the ICC profile
+ * shall be an RGB colour space for colour images (PNG colour types 2, 3, and
+ * 6), or a greyscale colour space for greyscale images (PNG colour types 0
+ * and 4)."
+ *
+ * This checking code ensures the embedded profile (on either read or write)
+ * conforms to the specification requirements. Notice that an ICC 'gray'
+ * color-space profile contains the information to transform the monochrome
+ * data to XYZ or L*a*b (according to which PCS the profile uses) and this
+ * should be used in preference to the standard libpng K channel replication
+ * into R, G and B channels.
+ *
+ * Previously it was suggested that an RGB profile on grayscale data could be
+ * handled. However it it is clear that using an RGB profile in this context
+ * must be an error - there is no specification of what it means. Thus it is
+ * almost certainly more correct to ignore the profile.
+ */
+ temp = png_get_uint_32(profile+16); /* data colour space field */
+ switch (temp)
+ {
+ case 0x52474220: /* 'RGB ' */
+ if ((color_type & PNG_COLOR_MASK_COLOR) == 0)
+ return png_icc_profile_error(png_ptr, colorspace, name, temp,
+ "RGB color space not permitted on grayscale PNG");
+ break;
+
+ case 0x47524159: /* 'GRAY' */
+ if ((color_type & PNG_COLOR_MASK_COLOR) != 0)
+ return png_icc_profile_error(png_ptr, colorspace, name, temp,
+ "Gray color space not permitted on RGB PNG");
+ break;
+
+ default:
+ return png_icc_profile_error(png_ptr, colorspace, name, temp,
+ "invalid ICC profile color space");
+ }
+
+ /* It is up to the application to check that the profile class matches the
+ * application requirements; the spec provides no guidance, but it's pretty
+ * weird if the profile is not scanner ('scnr'), monitor ('mntr'), printer
+ * ('prtr') or 'spac' (for generic color spaces). Issue a warning in these
+ * cases. Issue an error for device link or abstract profiles - these don't
+ * contain the records necessary to transform the color-space to anything
+ * other than the target device (and not even that for an abstract profile).
+ * Profiles of these classes may not be embedded in images.
+ */
+ temp = png_get_uint_32(profile+12); /* profile/device class */
+ switch (temp)
+ {
+ case 0x73636e72: /* 'scnr' */
+ case 0x6d6e7472: /* 'mntr' */
+ case 0x70727472: /* 'prtr' */
+ case 0x73706163: /* 'spac' */
+ /* All supported */
+ break;
+
+ case 0x61627374: /* 'abst' */
+ /* May not be embedded in an image */
+ return png_icc_profile_error(png_ptr, colorspace, name, temp,
+ "invalid embedded Abstract ICC profile");
+
+ case 0x6c696e6b: /* 'link' */
+ /* DeviceLink profiles cannot be interpreted in a non-device specific
+ * fashion, if an app uses the AToB0Tag in the profile the results are
+ * undefined unless the result is sent to the intended device,
+ * therefore a DeviceLink profile should not be found embedded in a
+ * PNG.
+ */
+ return png_icc_profile_error(png_ptr, colorspace, name, temp,
+ "unexpected DeviceLink ICC profile class");
+
+ case 0x6e6d636c: /* 'nmcl' */
+ /* A NamedColor profile is also device specific, however it doesn't
+ * contain an AToB0 tag that is open to misinterpretation. Almost
+ * certainly it will fail the tests below.
+ */
+ (void)png_icc_profile_error(png_ptr, NULL, name, temp,
+ "unexpected NamedColor ICC profile class");
+ break;
+
+ default:
+ /* To allow for future enhancements to the profile accept unrecognized
+ * profile classes with a warning, these then hit the test below on the
+ * tag content to ensure they are backward compatible with one of the
+ * understood profiles.
+ */
+ (void)png_icc_profile_error(png_ptr, NULL, name, temp,
+ "unrecognized ICC profile class");
+ break;
+ }
+
+ /* For any profile other than a device link one the PCS must be encoded
+ * either in XYZ or Lab.
+ */
+ temp = png_get_uint_32(profile+20);
+ switch (temp)
+ {
+ case 0x58595a20: /* 'XYZ ' */
+ case 0x4c616220: /* 'Lab ' */
+ break;
+
+ default:
+ return png_icc_profile_error(png_ptr, colorspace, name, temp,
+ "unexpected ICC PCS encoding");
+ }
+
+ return 1;
+}
+
+int /* PRIVATE */
+png_icc_check_tag_table(png_const_structrp png_ptr, png_colorspacerp colorspace,
+ png_const_charp name, png_uint_32 profile_length,
+ png_const_bytep profile /* header plus whole tag table */)
+{
+ png_uint_32 tag_count = png_get_uint_32(profile+128);
+ png_uint_32 itag;
+ png_const_bytep tag = profile+132; /* The first tag */
+
+ /* First scan all the tags in the table and add bits to the icc_info value
+ * (temporarily in 'tags').
+ */
+ for (itag=0; itag < tag_count; ++itag, tag += 12)
+ {
+ png_uint_32 tag_id = png_get_uint_32(tag+0);
+ png_uint_32 tag_start = png_get_uint_32(tag+4); /* must be aligned */
+ png_uint_32 tag_length = png_get_uint_32(tag+8);/* not padded */
+
+ /* The ICC specification does not exclude zero length tags, therefore the
+ * start might actually be anywhere if there is no data, but this would be
+ * a clear abuse of the intent of the standard so the start is checked for
+ * being in range. All defined tag types have an 8 byte header - a 4 byte
+ * type signature then 0.
+ */
+ if ((tag_start & 3) != 0)
+ {
+ /* CNHP730S.icc shipped with Microsoft Windows 64 violates this, it is
+ * only a warning here because libpng does not care about the
+ * alignment.
+ */
+ (void)png_icc_profile_error(png_ptr, NULL, name, tag_id,
+ "ICC profile tag start not a multiple of 4");
+ }
+
+ /* This is a hard error; potentially it can cause read outside the
+ * profile.
+ */
+ if (tag_start > profile_length || tag_length > profile_length - tag_start)
+ return png_icc_profile_error(png_ptr, colorspace, name, tag_id,
+ "ICC profile tag outside profile");
+ }
+
+ return 1; /* success, maybe with warnings */
+}
+
+#ifdef PNG_sRGB_SUPPORTED
+#if PNG_sRGB_PROFILE_CHECKS >= 0
+/* Information about the known ICC sRGB profiles */
+static const struct
+{
+ png_uint_32 adler, crc, length;
+ png_uint_32 md5[4];
+ png_byte have_md5;
+ png_byte is_broken;
+ png_uint_16 intent;
+
+# define PNG_MD5(a,b,c,d) { a, b, c, d }, (a!=0)||(b!=0)||(c!=0)||(d!=0)
+# define PNG_ICC_CHECKSUM(adler, crc, md5, intent, broke, date, length, fname)\
+ { adler, crc, length, md5, broke, intent },
+
+} png_sRGB_checks[] =
+{
+ /* This data comes from contrib/tools/checksum-icc run on downloads of
+ * all four ICC sRGB profiles from www.color.org.
+ */
+ /* adler32, crc32, MD5[4], intent, date, length, file-name */
+ PNG_ICC_CHECKSUM(0x0a3fd9f6, 0x3b8772b9,
+ PNG_MD5(0x29f83dde, 0xaff255ae, 0x7842fae4, 0xca83390d), 0, 0,
+ "2009/03/27 21:36:31", 3048, "sRGB_IEC61966-2-1_black_scaled.icc")
+
+ /* ICC sRGB v2 perceptual no black-compensation: */
+ PNG_ICC_CHECKSUM(0x4909e5e1, 0x427ebb21,
+ PNG_MD5(0xc95bd637, 0xe95d8a3b, 0x0df38f99, 0xc1320389), 1, 0,
+ "2009/03/27 21:37:45", 3052, "sRGB_IEC61966-2-1_no_black_scaling.icc")
+
+ PNG_ICC_CHECKSUM(0xfd2144a1, 0x306fd8ae,
+ PNG_MD5(0xfc663378, 0x37e2886b, 0xfd72e983, 0x8228f1b8), 0, 0,
+ "2009/08/10 17:28:01", 60988, "sRGB_v4_ICC_preference_displayclass.icc")
+
+ /* ICC sRGB v4 perceptual */
+ PNG_ICC_CHECKSUM(0x209c35d2, 0xbbef7812,
+ PNG_MD5(0x34562abf, 0x994ccd06, 0x6d2c5721, 0xd0d68c5d), 0, 0,
+ "2007/07/25 00:05:37", 60960, "sRGB_v4_ICC_preference.icc")
+
+ /* The following profiles have no known MD5 checksum. If there is a match
+ * on the (empty) MD5 the other fields are used to attempt a match and
+ * a warning is produced. The first two of these profiles have a 'cprt' tag
+ * which suggests that they were also made by Hewlett Packard.
+ */
+ PNG_ICC_CHECKSUM(0xa054d762, 0x5d5129ce,
+ PNG_MD5(0x00000000, 0x00000000, 0x00000000, 0x00000000), 1, 0,
+ "2004/07/21 18:57:42", 3024, "sRGB_IEC61966-2-1_noBPC.icc")
+
+ /* This is a 'mntr' (display) profile with a mediaWhitePointTag that does not
+ * match the D50 PCS illuminant in the header (it is in fact the D65 values,
+ * so the white point is recorded as the un-adapted value.) The profiles
+ * below only differ in one byte - the intent - and are basically the same as
+ * the previous profile except for the mediaWhitePointTag error and a missing
+ * chromaticAdaptationTag.
+ */
+ PNG_ICC_CHECKSUM(0xf784f3fb, 0x182ea552,
+ PNG_MD5(0x00000000, 0x00000000, 0x00000000, 0x00000000), 0, 1/*broken*/,
+ "1998/02/09 06:49:00", 3144, "HP-Microsoft sRGB v2 perceptual")
+
+ PNG_ICC_CHECKSUM(0x0398f3fc, 0xf29e526d,
+ PNG_MD5(0x00000000, 0x00000000, 0x00000000, 0x00000000), 1, 1/*broken*/,
+ "1998/02/09 06:49:00", 3144, "HP-Microsoft sRGB v2 media-relative")
+};
+
+static int
+png_compare_ICC_profile_with_sRGB(png_const_structrp png_ptr,
+ png_const_bytep profile, uLong adler)
+{
+ /* The quick check is to verify just the MD5 signature and trust the
+ * rest of the data. Because the profile has already been verified for
+ * correctness this is safe. png_colorspace_set_sRGB will check the 'intent'
+ * field too, so if the profile has been edited with an intent not defined
+ * by sRGB (but maybe defined by a later ICC specification) the read of
+ * the profile will fail at that point.
+ */
+
+ png_uint_32 length = 0;
+ png_uint_32 intent = 0x10000; /* invalid */
+#if PNG_sRGB_PROFILE_CHECKS > 1
+ uLong crc = 0; /* the value for 0 length data */
+#endif
+ unsigned int i;
+
+#ifdef PNG_SET_OPTION_SUPPORTED
+ /* First see if PNG_SKIP_sRGB_CHECK_PROFILE has been set to "on" */
+ if (((png_ptr->options >> PNG_SKIP_sRGB_CHECK_PROFILE) & 3) ==
+ PNG_OPTION_ON)
+ return 0;
+#endif
+
+ for (i=0; i < (sizeof png_sRGB_checks) / (sizeof png_sRGB_checks[0]); ++i)
+ {
+ if (png_get_uint_32(profile+84) == png_sRGB_checks[i].md5[0] &&
+ png_get_uint_32(profile+88) == png_sRGB_checks[i].md5[1] &&
+ png_get_uint_32(profile+92) == png_sRGB_checks[i].md5[2] &&
+ png_get_uint_32(profile+96) == png_sRGB_checks[i].md5[3])
+ {
+ /* This may be one of the old HP profiles without an MD5, in that
+ * case we can only use the length and Adler32 (note that these
+ * are not used by default if there is an MD5!)
+ */
+# if PNG_sRGB_PROFILE_CHECKS == 0
+ if (png_sRGB_checks[i].have_md5 != 0)
+ return 1+png_sRGB_checks[i].is_broken;
+# endif
+
+ /* Profile is unsigned or more checks have been configured in. */
+ if (length == 0)
+ {
+ length = png_get_uint_32(profile);
+ intent = png_get_uint_32(profile+64);
+ }
+
+ /* Length *and* intent must match */
+ if (length == (png_uint_32) png_sRGB_checks[i].length &&
+ intent == (png_uint_32) png_sRGB_checks[i].intent)
+ {
+ /* Now calculate the adler32 if not done already. */
+ if (adler == 0)
+ {
+ adler = adler32(0, NULL, 0);
+ adler = adler32(adler, profile, length);
+ }
+
+ if (adler == png_sRGB_checks[i].adler)
+ {
+ /* These basic checks suggest that the data has not been
+ * modified, but if the check level is more than 1 perform
+ * our own crc32 checksum on the data.
+ */
+# if PNG_sRGB_PROFILE_CHECKS > 1
+ if (crc == 0)
+ {
+ crc = crc32(0, NULL, 0);
+ crc = crc32(crc, profile, length);
+ }
+
+ /* So this check must pass for the 'return' below to happen.
+ */
+ if (crc == png_sRGB_checks[i].crc)
+# endif
+ {
+ if (png_sRGB_checks[i].is_broken != 0)
+ {
+ /* These profiles are known to have bad data that may cause
+ * problems if they are used, therefore attempt to
+ * discourage their use, skip the 'have_md5' warning below,
+ * which is made irrelevant by this error.
+ */
+ png_chunk_report(png_ptr, "known incorrect sRGB profile",
+ PNG_CHUNK_ERROR);
+ }
+
+ /* Warn that this being done; this isn't even an error since
+ * the profile is perfectly valid, but it would be nice if
+ * people used the up-to-date ones.
+ */
+ else if (png_sRGB_checks[i].have_md5 == 0)
+ {
+ png_chunk_report(png_ptr,
+ "out-of-date sRGB profile with no signature",
+ PNG_CHUNK_WARNING);
+ }
+
+ return 1+png_sRGB_checks[i].is_broken;
+ }
+ }
+
+# if PNG_sRGB_PROFILE_CHECKS > 0
+ /* The signature matched, but the profile had been changed in some
+ * way. This probably indicates a data error or uninformed hacking.
+ * Fall through to "no match".
+ */
+ png_chunk_report(png_ptr,
+ "Not recognizing known sRGB profile that has been edited",
+ PNG_CHUNK_WARNING);
+ break;
+# endif
+ }
+ }
+ }
+
+ return 0; /* no match */
+}
+#endif /* PNG_sRGB_PROFILE_CHECKS >= 0 */
+
+void /* PRIVATE */
+png_icc_set_sRGB(png_const_structrp png_ptr,
+ png_colorspacerp colorspace, png_const_bytep profile, uLong adler)
+{
+ /* Is this profile one of the known ICC sRGB profiles? If it is, just set
+ * the sRGB information.
+ */
+#if PNG_sRGB_PROFILE_CHECKS >= 0
+ if (png_compare_ICC_profile_with_sRGB(png_ptr, profile, adler) != 0)
+#endif
+ (void)png_colorspace_set_sRGB(png_ptr, colorspace,
+ (int)/*already checked*/png_get_uint_32(profile+64));
+}
+#endif /* sRGB */
+
+int /* PRIVATE */
+png_colorspace_set_ICC(png_const_structrp png_ptr, png_colorspacerp colorspace,
+ png_const_charp name, png_uint_32 profile_length, png_const_bytep profile,
+ int color_type)
+{
+ if ((colorspace->flags & PNG_COLORSPACE_INVALID) != 0)
+ return 0;
+
+ if (png_icc_check_length(png_ptr, colorspace, name, profile_length) != 0 &&
+ png_icc_check_header(png_ptr, colorspace, name, profile_length, profile,
+ color_type) != 0 &&
+ png_icc_check_tag_table(png_ptr, colorspace, name, profile_length,
+ profile) != 0)
+ {
+# ifdef PNG_sRGB_SUPPORTED
+ /* If no sRGB support, don't try storing sRGB information */
+ png_icc_set_sRGB(png_ptr, colorspace, profile, 0);
+# endif
+ return 1;
+ }
+
+ /* Failure case */
+ return 0;
+}
+#endif /* iCCP */
+
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+void /* PRIVATE */
+png_colorspace_set_rgb_coefficients(png_structrp png_ptr)
+{
+ /* Set the rgb_to_gray coefficients from the colorspace. */
+ if (png_ptr->rgb_to_gray_coefficients_set == 0 &&
+ (png_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_ENDPOINTS) != 0)
+ {
+ /* png_set_background has not been called, get the coefficients from the Y
+ * values of the colorspace colorants.
+ */
+ png_fixed_point r = png_ptr->colorspace.end_points_XYZ.red_Y;
+ png_fixed_point g = png_ptr->colorspace.end_points_XYZ.green_Y;
+ png_fixed_point b = png_ptr->colorspace.end_points_XYZ.blue_Y;
+ png_fixed_point total = r+g+b;
+
+ if (total > 0 &&
+ r >= 0 && png_muldiv(&r, r, 32768, total) && r >= 0 && r <= 32768 &&
+ g >= 0 && png_muldiv(&g, g, 32768, total) && g >= 0 && g <= 32768 &&
+ b >= 0 && png_muldiv(&b, b, 32768, total) && b >= 0 && b <= 32768 &&
+ r+g+b <= 32769)
+ {
+ /* We allow 0 coefficients here. r+g+b may be 32769 if two or
+ * all of the coefficients were rounded up. Handle this by
+ * reducing the *largest* coefficient by 1; this matches the
+ * approach used for the default coefficients in pngrtran.c
+ */
+ int add = 0;
+
+ if (r+g+b > 32768)
+ add = -1;
+ else if (r+g+b < 32768)
+ add = 1;
+
+ if (add != 0)
+ {
+ if (g >= r && g >= b)
+ g += add;
+ else if (r >= g && r >= b)
+ r += add;
+ else
+ b += add;
+ }
+
+ /* Check for an internal error. */
+ if (r+g+b != 32768)
+ png_error(png_ptr,
+ "internal error handling cHRM coefficients");
+
+ else
+ {
+ png_ptr->rgb_to_gray_red_coeff = (png_uint_16)r;
+ png_ptr->rgb_to_gray_green_coeff = (png_uint_16)g;
+ }
+ }
+
+ /* This is a png_error at present even though it could be ignored -
+ * it should never happen, but it is important that if it does, the
+ * bug is fixed.
+ */
+ else
+ png_error(png_ptr, "internal error handling cHRM->XYZ");
+ }
+}
+#endif /* READ_RGB_TO_GRAY */
+
+#endif /* COLORSPACE */
+
+#ifdef __GNUC__
+/* This exists solely to work round a warning from GNU C. */
+static int /* PRIVATE */
+png_gt(size_t a, size_t b)
+{
+ return a > b;
+}
+#else
+# define png_gt(a,b) ((a) > (b))
+#endif
+
+void /* PRIVATE */
+png_check_IHDR(png_const_structrp png_ptr,
+ png_uint_32 width, png_uint_32 height, int bit_depth,
+ int color_type, int interlace_type, int compression_type,
+ int filter_type)
+{
+ int error = 0;
+
+ /* Check for width and height valid values */
+ if (width == 0)
+ {
+ png_warning(png_ptr, "Image width is zero in IHDR");
+ error = 1;
+ }
+
+ if (width > PNG_UINT_31_MAX)
+ {
+ png_warning(png_ptr, "Invalid image width in IHDR");
+ error = 1;
+ }
+
+ if (png_gt(((width + 7) & (~7)),
+ ((PNG_SIZE_MAX
+ - 48 /* big_row_buf hack */
+ - 1) /* filter byte */
+ / 8) /* 8-byte RGBA pixels */
+ - 1)) /* extra max_pixel_depth pad */
+ {
+ /* The size of the row must be within the limits of this architecture.
+ * Because the read code can perform arbitrary transformations the
+ * maximum size is checked here. Because the code in png_read_start_row
+ * adds extra space "for safety's sake" in several places a conservative
+ * limit is used here.
+ *
+ * NOTE: it would be far better to check the size that is actually used,
+ * but the effect in the real world is minor and the changes are more
+ * extensive, therefore much more dangerous and much more difficult to
+ * write in a way that avoids compiler warnings.
+ */
+ png_warning(png_ptr, "Image width is too large for this architecture");
+ error = 1;
+ }
+
+#ifdef PNG_SET_USER_LIMITS_SUPPORTED
+ if (width > png_ptr->user_width_max)
+#else
+ if (width > PNG_USER_WIDTH_MAX)
+#endif
+ {
+ png_warning(png_ptr, "Image width exceeds user limit in IHDR");
+ error = 1;
+ }
+
+ if (height == 0)
+ {
+ png_warning(png_ptr, "Image height is zero in IHDR");
+ error = 1;
+ }
+
+ if (height > PNG_UINT_31_MAX)
+ {
+ png_warning(png_ptr, "Invalid image height in IHDR");
+ error = 1;
+ }
+
+#ifdef PNG_SET_USER_LIMITS_SUPPORTED
+ if (height > png_ptr->user_height_max)
+#else
+ if (height > PNG_USER_HEIGHT_MAX)
+#endif
+ {
+ png_warning(png_ptr, "Image height exceeds user limit in IHDR");
+ error = 1;
+ }
+
+ /* Check other values */
+ if (bit_depth != 1 && bit_depth != 2 && bit_depth != 4 &&
+ bit_depth != 8 && bit_depth != 16)
+ {
+ png_warning(png_ptr, "Invalid bit depth in IHDR");
+ error = 1;
+ }
+
+ if (color_type < 0 || color_type == 1 ||
+ color_type == 5 || color_type > 6)
+ {
+ png_warning(png_ptr, "Invalid color type in IHDR");
+ error = 1;
+ }
+
+ if (((color_type == PNG_COLOR_TYPE_PALETTE) && bit_depth > 8) ||
+ ((color_type == PNG_COLOR_TYPE_RGB ||
+ color_type == PNG_COLOR_TYPE_GRAY_ALPHA ||
+ color_type == PNG_COLOR_TYPE_RGB_ALPHA) && bit_depth < 8))
+ {
+ png_warning(png_ptr, "Invalid color type/bit depth combination in IHDR");
+ error = 1;
+ }
+
+ if (interlace_type >= PNG_INTERLACE_LAST)
+ {
+ png_warning(png_ptr, "Unknown interlace method in IHDR");
+ error = 1;
+ }
+
+ if (compression_type != PNG_COMPRESSION_TYPE_BASE)
+ {
+ png_warning(png_ptr, "Unknown compression method in IHDR");
+ error = 1;
+ }
+
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+ /* Accept filter_method 64 (intrapixel differencing) only if
+ * 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and
+ * 2. Libpng did not read a PNG signature (this filter_method is only
+ * used in PNG datastreams that are embedded in MNG datastreams) and
+ * 3. The application called png_permit_mng_features with a mask that
+ * included PNG_FLAG_MNG_FILTER_64 and
+ * 4. The filter_method is 64 and
+ * 5. The color_type is RGB or RGBA
+ */
+ if ((png_ptr->mode & PNG_HAVE_PNG_SIGNATURE) != 0 &&
+ png_ptr->mng_features_permitted != 0)
+ png_warning(png_ptr, "MNG features are not allowed in a PNG datastream");
+
+ if (filter_type != PNG_FILTER_TYPE_BASE)
+ {
+ if (!((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) != 0 &&
+ (filter_type == PNG_INTRAPIXEL_DIFFERENCING) &&
+ ((png_ptr->mode & PNG_HAVE_PNG_SIGNATURE) == 0) &&
+ (color_type == PNG_COLOR_TYPE_RGB ||
+ color_type == PNG_COLOR_TYPE_RGB_ALPHA)))
+ {
+ png_warning(png_ptr, "Unknown filter method in IHDR");
+ error = 1;
+ }
+
+ if ((png_ptr->mode & PNG_HAVE_PNG_SIGNATURE) != 0)
+ {
+ png_warning(png_ptr, "Invalid filter method in IHDR");
+ error = 1;
+ }
+ }
+
+#else
+ if (filter_type != PNG_FILTER_TYPE_BASE)
+ {
+ png_warning(png_ptr, "Unknown filter method in IHDR");
+ error = 1;
+ }
+#endif
+
+ if (error == 1)
+ png_error(png_ptr, "Invalid IHDR data");
+}
+
+#if defined(PNG_sCAL_SUPPORTED) || defined(PNG_pCAL_SUPPORTED)
+/* ASCII to fp functions */
+/* Check an ASCII formated floating point value, see the more detailed
+ * comments in pngpriv.h
+ */
+/* The following is used internally to preserve the sticky flags */
+#define png_fp_add(state, flags) ((state) |= (flags))
+#define png_fp_set(state, value) ((state) = (value) | ((state) & PNG_FP_STICKY))
+
+int /* PRIVATE */
+png_check_fp_number(png_const_charp string, png_size_t size, int *statep,
+ png_size_tp whereami)
+{
+ int state = *statep;
+ png_size_t i = *whereami;
+
+ while (i < size)
+ {
+ int type;
+ /* First find the type of the next character */
+ switch (string[i])
+ {
+ case 43: type = PNG_FP_SAW_SIGN; break;
+ case 45: type = PNG_FP_SAW_SIGN + PNG_FP_NEGATIVE; break;
+ case 46: type = PNG_FP_SAW_DOT; break;
+ case 48: type = PNG_FP_SAW_DIGIT; break;
+ case 49: case 50: case 51: case 52:
+ case 53: case 54: case 55: case 56:
+ case 57: type = PNG_FP_SAW_DIGIT + PNG_FP_NONZERO; break;
+ case 69:
+ case 101: type = PNG_FP_SAW_E; break;
+ default: goto PNG_FP_End;
+ }
+
+ /* Now deal with this type according to the current
+ * state, the type is arranged to not overlap the
+ * bits of the PNG_FP_STATE.
+ */
+ switch ((state & PNG_FP_STATE) + (type & PNG_FP_SAW_ANY))
+ {
+ case PNG_FP_INTEGER + PNG_FP_SAW_SIGN:
+ if ((state & PNG_FP_SAW_ANY) != 0)
+ goto PNG_FP_End; /* not a part of the number */
+
+ png_fp_add(state, type);
+ break;
+
+ case PNG_FP_INTEGER + PNG_FP_SAW_DOT:
+ /* Ok as trailer, ok as lead of fraction. */
+ if ((state & PNG_FP_SAW_DOT) != 0) /* two dots */
+ goto PNG_FP_End;
+
+ else if ((state & PNG_FP_SAW_DIGIT) != 0) /* trailing dot? */
+ png_fp_add(state, type);
+
+ else
+ png_fp_set(state, PNG_FP_FRACTION | type);
+
+ break;
+
+ case PNG_FP_INTEGER + PNG_FP_SAW_DIGIT:
+ if ((state & PNG_FP_SAW_DOT) != 0) /* delayed fraction */
+ png_fp_set(state, PNG_FP_FRACTION | PNG_FP_SAW_DOT);
+
+ png_fp_add(state, type | PNG_FP_WAS_VALID);
+
+ break;
+
+ case PNG_FP_INTEGER + PNG_FP_SAW_E:
+ if ((state & PNG_FP_SAW_DIGIT) == 0)
+ goto PNG_FP_End;
+
+ png_fp_set(state, PNG_FP_EXPONENT);
+
+ break;
+
+ /* case PNG_FP_FRACTION + PNG_FP_SAW_SIGN:
+ goto PNG_FP_End; ** no sign in fraction */
+
+ /* case PNG_FP_FRACTION + PNG_FP_SAW_DOT:
+ goto PNG_FP_End; ** Because SAW_DOT is always set */
+
+ case PNG_FP_FRACTION + PNG_FP_SAW_DIGIT:
+ png_fp_add(state, type | PNG_FP_WAS_VALID);
+ break;
+
+ case PNG_FP_FRACTION + PNG_FP_SAW_E:
+ /* This is correct because the trailing '.' on an
+ * integer is handled above - so we can only get here
+ * with the sequence ".E" (with no preceding digits).
+ */
+ if ((state & PNG_FP_SAW_DIGIT) == 0)
+ goto PNG_FP_End;
+
+ png_fp_set(state, PNG_FP_EXPONENT);
+
+ break;
+
+ case PNG_FP_EXPONENT + PNG_FP_SAW_SIGN:
+ if ((state & PNG_FP_SAW_ANY) != 0)
+ goto PNG_FP_End; /* not a part of the number */
+
+ png_fp_add(state, PNG_FP_SAW_SIGN);
+
+ break;
+
+ /* case PNG_FP_EXPONENT + PNG_FP_SAW_DOT:
+ goto PNG_FP_End; */
+
+ case PNG_FP_EXPONENT + PNG_FP_SAW_DIGIT:
+ png_fp_add(state, PNG_FP_SAW_DIGIT | PNG_FP_WAS_VALID);
+
+ break;
+
+ /* case PNG_FP_EXPONEXT + PNG_FP_SAW_E:
+ goto PNG_FP_End; */
+
+ default: goto PNG_FP_End; /* I.e. break 2 */
+ }
+
+ /* The character seems ok, continue. */
+ ++i;
+ }
+
+PNG_FP_End:
+ /* Here at the end, update the state and return the correct
+ * return code.
+ */
+ *statep = state;
+ *whereami = i;
+
+ return (state & PNG_FP_SAW_DIGIT) != 0;
+}
+
+
+/* The same but for a complete string. */
+int
+png_check_fp_string(png_const_charp string, png_size_t size)
+{
+ int state=0;
+ png_size_t char_index=0;
+
+ if (png_check_fp_number(string, size, &state, &char_index) != 0 &&
+ (char_index == size || string[char_index] == 0))
+ return state /* must be non-zero - see above */;
+
+ return 0; /* i.e. fail */
+}
+#endif /* pCAL || sCAL */
+
+#ifdef PNG_sCAL_SUPPORTED
+# ifdef PNG_FLOATING_POINT_SUPPORTED
+/* Utility used below - a simple accurate power of ten from an integral
+ * exponent.
+ */
+static double
+png_pow10(int power)
+{
+ int recip = 0;
+ double d = 1;
+
+ /* Handle negative exponent with a reciprocal at the end because
+ * 10 is exact whereas .1 is inexact in base 2
+ */
+ if (power < 0)
+ {
+ if (power < DBL_MIN_10_EXP) return 0;
+ recip = 1, power = -power;
+ }
+
+ if (power > 0)
+ {
+ /* Decompose power bitwise. */
+ double mult = 10;
+ do
+ {
+ if (power & 1) d *= mult;
+ mult *= mult;
+ power >>= 1;
+ }
+ while (power > 0);
+
+ if (recip != 0) d = 1/d;
+ }
+ /* else power is 0 and d is 1 */
+
+ return d;
+}
+
+/* Function to format a floating point value in ASCII with a given
+ * precision.
+ */
+void /* PRIVATE */
+png_ascii_from_fp(png_const_structrp png_ptr, png_charp ascii, png_size_t size,
+ double fp, unsigned int precision)
+{
+ /* We use standard functions from math.h, but not printf because
+ * that would require stdio. The caller must supply a buffer of
+ * sufficient size or we will png_error. The tests on size and
+ * the space in ascii[] consumed are indicated below.
+ */
+ if (precision < 1)
+ precision = DBL_DIG;
+
+ /* Enforce the limit of the implementation precision too. */
+ if (precision > DBL_DIG+1)
+ precision = DBL_DIG+1;
+
+ /* Basic sanity checks */
+ if (size >= precision+5) /* See the requirements below. */
+ {
+ if (fp < 0)
+ {
+ fp = -fp;
+ *ascii++ = 45; /* '-' PLUS 1 TOTAL 1 */
+ --size;
+ }
+
+ if (fp >= DBL_MIN && fp <= DBL_MAX)
+ {
+ int exp_b10; /* A base 10 exponent */
+ double base; /* 10^exp_b10 */
+
+ /* First extract a base 10 exponent of the number,
+ * the calculation below rounds down when converting
+ * from base 2 to base 10 (multiply by log10(2) -
+ * 0.3010, but 77/256 is 0.3008, so exp_b10 needs to
+ * be increased. Note that the arithmetic shift
+ * performs a floor() unlike C arithmetic - using a
+ * C multiply would break the following for negative
+ * exponents.
+ */
+ (void)frexp(fp, &exp_b10); /* exponent to base 2 */
+
+ exp_b10 = (exp_b10 * 77) >> 8; /* <= exponent to base 10 */
+
+ /* Avoid underflow here. */
+ base = png_pow10(exp_b10); /* May underflow */
+
+ while (base < DBL_MIN || base < fp)
+ {
+ /* And this may overflow. */
+ double test = png_pow10(exp_b10+1);
+
+ if (test <= DBL_MAX)
+ ++exp_b10, base = test;
+
+ else
+ break;
+ }
+
+ /* Normalize fp and correct exp_b10, after this fp is in the
+ * range [.1,1) and exp_b10 is both the exponent and the digit
+ * *before* which the decimal point should be inserted
+ * (starting with 0 for the first digit). Note that this
+ * works even if 10^exp_b10 is out of range because of the
+ * test on DBL_MAX above.
+ */
+ fp /= base;
+ while (fp >= 1) fp /= 10, ++exp_b10;
+
+ /* Because of the code above fp may, at this point, be
+ * less than .1, this is ok because the code below can
+ * handle the leading zeros this generates, so no attempt
+ * is made to correct that here.
+ */
+
+ {
+ unsigned int czero, clead, cdigits;
+ char exponent[10];
+
+ /* Allow up to two leading zeros - this will not lengthen
+ * the number compared to using E-n.
+ */
+ if (exp_b10 < 0 && exp_b10 > -3) /* PLUS 3 TOTAL 4 */
+ {
+ czero = -exp_b10; /* PLUS 2 digits: TOTAL 3 */
+ exp_b10 = 0; /* Dot added below before first output. */
+ }
+ else
+ czero = 0; /* No zeros to add */
+
+ /* Generate the digit list, stripping trailing zeros and
+ * inserting a '.' before a digit if the exponent is 0.
+ */
+ clead = czero; /* Count of leading zeros */
+ cdigits = 0; /* Count of digits in list. */
+
+ do
+ {
+ double d;
+
+ fp *= 10;
+ /* Use modf here, not floor and subtract, so that
+ * the separation is done in one step. At the end
+ * of the loop don't break the number into parts so
+ * that the final digit is rounded.
+ */
+ if (cdigits+czero+1 < precision+clead)
+ fp = modf(fp, &d);
+
+ else
+ {
+ d = floor(fp + .5);
+
+ if (d > 9)
+ {
+ /* Rounding up to 10, handle that here. */
+ if (czero > 0)
+ {
+ --czero, d = 1;
+ if (cdigits == 0) --clead;
+ }
+ else
+ {
+ while (cdigits > 0 && d > 9)
+ {
+ int ch = *--ascii;
+
+ if (exp_b10 != (-1))
+ ++exp_b10;
+
+ else if (ch == 46)
+ {
+ ch = *--ascii, ++size;
+ /* Advance exp_b10 to '1', so that the
+ * decimal point happens after the
+ * previous digit.
+ */
+ exp_b10 = 1;
+ }
+
+ --cdigits;
+ d = ch - 47; /* I.e. 1+(ch-48) */
+ }
+
+ /* Did we reach the beginning? If so adjust the
+ * exponent but take into account the leading
+ * decimal point.
+ */
+ if (d > 9) /* cdigits == 0 */
+ {
+ if (exp_b10 == (-1))
+ {
+ /* Leading decimal point (plus zeros?), if
+ * we lose the decimal point here it must
+ * be reentered below.
+ */
+ int ch = *--ascii;
+
+ if (ch == 46)
+ ++size, exp_b10 = 1;
+
+ /* Else lost a leading zero, so 'exp_b10' is
+ * still ok at (-1)
+ */
+ }
+ else
+ ++exp_b10;
+
+ /* In all cases we output a '1' */
+ d = 1;
+ }
+ }
+ }
+ fp = 0; /* Guarantees termination below. */
+ }
+
+ if (d == 0)
+ {
+ ++czero;
+ if (cdigits == 0) ++clead;
+ }
+ else
+ {
+ /* Included embedded zeros in the digit count. */
+ cdigits += czero - clead;
+ clead = 0;
+
+ while (czero > 0)
+ {
+ /* exp_b10 == (-1) means we just output the decimal
+ * place - after the DP don't adjust 'exp_b10' any
+ * more!
+ */
+ if (exp_b10 != (-1))
+ {
+ if (exp_b10 == 0) *ascii++ = 46, --size;
+ /* PLUS 1: TOTAL 4 */
+ --exp_b10;
+ }
+ *ascii++ = 48, --czero;
+ }
+
+ if (exp_b10 != (-1))
+ {
+ if (exp_b10 == 0)
+ *ascii++ = 46, --size; /* counted above */
+
+ --exp_b10;
+ }
+ *ascii++ = (char)(48 + (int)d), ++cdigits;
+ }
+ }
+ while (cdigits+czero < precision+clead && fp > DBL_MIN);
+
+ /* The total output count (max) is now 4+precision */
+
+ /* Check for an exponent, if we don't need one we are
+ * done and just need to terminate the string. At
+ * this point exp_b10==(-1) is effectively if flag - it got
+ * to '-1' because of the decrement after outputting
+ * the decimal point above (the exponent required is
+ * *not* -1!)
+ */
+ if (exp_b10 >= (-1) && exp_b10 <= 2)
+ {
+ /* The following only happens if we didn't output the
+ * leading zeros above for negative exponent, so this
+ * doesn't add to the digit requirement. Note that the
+ * two zeros here can only be output if the two leading
+ * zeros were *not* output, so this doesn't increase
+ * the output count.
+ */
+ while (--exp_b10 >= 0) *ascii++ = 48;
+
+ *ascii = 0;
+
+ /* Total buffer requirement (including the '\0') is
+ * 5+precision - see check at the start.
+ */
+ return;
+ }
+
+ /* Here if an exponent is required, adjust size for
+ * the digits we output but did not count. The total
+ * digit output here so far is at most 1+precision - no
+ * decimal point and no leading or trailing zeros have
+ * been output.
+ */
+ size -= cdigits;
+
+ *ascii++ = 69, --size; /* 'E': PLUS 1 TOTAL 2+precision */
+
+ /* The following use of an unsigned temporary avoids ambiguities in
+ * the signed arithmetic on exp_b10 and permits GCC at least to do
+ * better optimization.
+ */
+ {
+ unsigned int uexp_b10;
+
+ if (exp_b10 < 0)
+ {
+ *ascii++ = 45, --size; /* '-': PLUS 1 TOTAL 3+precision */
+ uexp_b10 = -exp_b10;
+ }
+
+ else
+ uexp_b10 = exp_b10;
+
+ cdigits = 0;
+
+ while (uexp_b10 > 0)
+ {
+ exponent[cdigits++] = (char)(48 + uexp_b10 % 10);
+ uexp_b10 /= 10;
+ }
+ }
+
+ /* Need another size check here for the exponent digits, so
+ * this need not be considered above.
+ */
+ if (size > cdigits)
+ {
+ while (cdigits > 0) *ascii++ = exponent[--cdigits];
+
+ *ascii = 0;
+
+ return;
+ }
+ }
+ }
+ else if (!(fp >= DBL_MIN))
+ {
+ *ascii++ = 48; /* '0' */
+ *ascii = 0;
+ return;
+ }
+ else
+ {
+ *ascii++ = 105; /* 'i' */
+ *ascii++ = 110; /* 'n' */
+ *ascii++ = 102; /* 'f' */
+ *ascii = 0;
+ return;
+ }
+ }
+
+ /* Here on buffer too small. */
+ png_error(png_ptr, "ASCII conversion buffer too small");
+}
+
+# endif /* FLOATING_POINT */
+
+# ifdef PNG_FIXED_POINT_SUPPORTED
+/* Function to format a fixed point value in ASCII.
+ */
+void /* PRIVATE */
+png_ascii_from_fixed(png_const_structrp png_ptr, png_charp ascii,
+ png_size_t size, png_fixed_point fp)
+{
+ /* Require space for 10 decimal digits, a decimal point, a minus sign and a
+ * trailing \0, 13 characters:
+ */
+ if (size > 12)
+ {
+ png_uint_32 num;
+
+ /* Avoid overflow here on the minimum integer. */
+ if (fp < 0)
+ *ascii++ = 45, num = -fp;
+ else
+ num = fp;
+
+ if (num <= 0x80000000) /* else overflowed */
+ {
+ unsigned int ndigits = 0, first = 16 /* flag value */;
+ char digits[10];
+
+ while (num)
+ {
+ /* Split the low digit off num: */
+ unsigned int tmp = num/10;
+ num -= tmp*10;
+ digits[ndigits++] = (char)(48 + num);
+ /* Record the first non-zero digit, note that this is a number
+ * starting at 1, it's not actually the array index.
+ */
+ if (first == 16 && num > 0)
+ first = ndigits;
+ num = tmp;
+ }
+
+ if (ndigits > 0)
+ {
+ while (ndigits > 5) *ascii++ = digits[--ndigits];
+ /* The remaining digits are fractional digits, ndigits is '5' or
+ * smaller at this point. It is certainly not zero. Check for a
+ * non-zero fractional digit:
+ */
+ if (first <= 5)
+ {
+ unsigned int i;
+ *ascii++ = 46; /* decimal point */
+ /* ndigits may be <5 for small numbers, output leading zeros
+ * then ndigits digits to first:
+ */
+ i = 5;
+ while (ndigits < i) *ascii++ = 48, --i;
+ while (ndigits >= first) *ascii++ = digits[--ndigits];
+ /* Don't output the trailing zeros! */
+ }
+ }
+ else
+ *ascii++ = 48;
+
+ /* And null terminate the string: */
+ *ascii = 0;
+ return;
+ }
+ }
+
+ /* Here on buffer too small. */
+ png_error(png_ptr, "ASCII conversion buffer too small");
+}
+# endif /* FIXED_POINT */
+#endif /* SCAL */
+
+#if defined(PNG_FLOATING_POINT_SUPPORTED) && \
+ !defined(PNG_FIXED_POINT_MACRO_SUPPORTED) && \
+ (defined(PNG_gAMA_SUPPORTED) || defined(PNG_cHRM_SUPPORTED) || \
+ defined(PNG_sCAL_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) || \
+ defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)) || \
+ (defined(PNG_sCAL_SUPPORTED) && \
+ defined(PNG_FLOATING_ARITHMETIC_SUPPORTED))
+png_fixed_point
+png_fixed(png_const_structrp png_ptr, double fp, png_const_charp text)
+{
+ double r = floor(100000 * fp + .5);
+
+ if (r > 2147483647. || r < -2147483648.)
+ png_fixed_error(png_ptr, text);
+
+# ifndef PNG_ERROR_TEXT_SUPPORTED
+ PNG_UNUSED(text)
+# endif
+
+ return (png_fixed_point)r;
+}
+#endif
+
+#if defined(PNG_GAMMA_SUPPORTED) || defined(PNG_COLORSPACE_SUPPORTED) ||\
+ defined(PNG_INCH_CONVERSIONS_SUPPORTED) || defined(PNG_READ_pHYs_SUPPORTED)
+/* muldiv functions */
+/* This API takes signed arguments and rounds the result to the nearest
+ * integer (or, for a fixed point number - the standard argument - to
+ * the nearest .00001). Overflow and divide by zero are signalled in
+ * the result, a boolean - true on success, false on overflow.
+ */
+int
+png_muldiv(png_fixed_point_p res, png_fixed_point a, png_int_32 times,
+ png_int_32 divisor)
+{
+ /* Return a * times / divisor, rounded. */
+ if (divisor != 0)
+ {
+ if (a == 0 || times == 0)
+ {
+ *res = 0;
+ return 1;
+ }
+ else
+ {
+#ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED
+ double r = a;
+ r *= times;
+ r /= divisor;
+ r = floor(r+.5);
+
+ /* A png_fixed_point is a 32-bit integer. */
+ if (r <= 2147483647. && r >= -2147483648.)
+ {
+ *res = (png_fixed_point)r;
+ return 1;
+ }
+#else
+ int negative = 0;
+ png_uint_32 A, T, D;
+ png_uint_32 s16, s32, s00;
+
+ if (a < 0)
+ negative = 1, A = -a;
+ else
+ A = a;
+
+ if (times < 0)
+ negative = !negative, T = -times;
+ else
+ T = times;
+
+ if (divisor < 0)
+ negative = !negative, D = -divisor;
+ else
+ D = divisor;
+
+ /* Following can't overflow because the arguments only
+ * have 31 bits each, however the result may be 32 bits.
+ */
+ s16 = (A >> 16) * (T & 0xffff) +
+ (A & 0xffff) * (T >> 16);
+ /* Can't overflow because the a*times bit is only 30
+ * bits at most.
+ */
+ s32 = (A >> 16) * (T >> 16) + (s16 >> 16);
+ s00 = (A & 0xffff) * (T & 0xffff);
+
+ s16 = (s16 & 0xffff) << 16;
+ s00 += s16;
+
+ if (s00 < s16)
+ ++s32; /* carry */
+
+ if (s32 < D) /* else overflow */
+ {
+ /* s32.s00 is now the 64-bit product, do a standard
+ * division, we know that s32 < D, so the maximum
+ * required shift is 31.
+ */
+ int bitshift = 32;
+ png_fixed_point result = 0; /* NOTE: signed */
+
+ while (--bitshift >= 0)
+ {
+ png_uint_32 d32, d00;
+
+ if (bitshift > 0)
+ d32 = D >> (32-bitshift), d00 = D << bitshift;
+
+ else
+ d32 = 0, d00 = D;
+
+ if (s32 > d32)
+ {
+ if (s00 < d00) --s32; /* carry */
+ s32 -= d32, s00 -= d00, result += 1<<bitshift;
+ }
+
+ else
+ if (s32 == d32 && s00 >= d00)
+ s32 = 0, s00 -= d00, result += 1<<bitshift;
+ }
+
+ /* Handle the rounding. */
+ if (s00 >= (D >> 1))
+ ++result;
+
+ if (negative != 0)
+ result = -result;
+
+ /* Check for overflow. */
+ if ((negative != 0 && result <= 0) ||
+ (negative == 0 && result >= 0))
+ {
+ *res = result;
+ return 1;
+ }
+ }
+#endif
+ }
+ }
+
+ return 0;
+}
+#endif /* READ_GAMMA || INCH_CONVERSIONS */
+
+#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_INCH_CONVERSIONS_SUPPORTED)
+/* The following is for when the caller doesn't much care about the
+ * result.
+ */
+png_fixed_point
+png_muldiv_warn(png_const_structrp png_ptr, png_fixed_point a, png_int_32 times,
+ png_int_32 divisor)
+{
+ png_fixed_point result;
+
+ if (png_muldiv(&result, a, times, divisor) != 0)
+ return result;
+
+ png_warning(png_ptr, "fixed point overflow ignored");
+ return 0;
+}
+#endif
+
+#ifdef PNG_GAMMA_SUPPORTED /* more fixed point functions for gamma */
+/* Calculate a reciprocal, return 0 on div-by-zero or overflow. */
+png_fixed_point
+png_reciprocal(png_fixed_point a)
+{
+#ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED
+ double r = floor(1E10/a+.5);
+
+ if (r <= 2147483647. && r >= -2147483648.)
+ return (png_fixed_point)r;
+#else
+ png_fixed_point res;
+
+ if (png_muldiv(&res, 100000, 100000, a) != 0)
+ return res;
+#endif
+
+ return 0; /* error/overflow */
+}
+
+/* This is the shared test on whether a gamma value is 'significant' - whether
+ * it is worth doing gamma correction.
+ */
+int /* PRIVATE */
+png_gamma_significant(png_fixed_point gamma_val)
+{
+ return gamma_val < PNG_FP_1 - PNG_GAMMA_THRESHOLD_FIXED ||
+ gamma_val > PNG_FP_1 + PNG_GAMMA_THRESHOLD_FIXED;
+}
+#endif
+
+#ifdef PNG_READ_GAMMA_SUPPORTED
+#ifdef PNG_16BIT_SUPPORTED
+/* A local convenience routine. */
+static png_fixed_point
+png_product2(png_fixed_point a, png_fixed_point b)
+{
+ /* The required result is 1/a * 1/b; the following preserves accuracy. */
+#ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED
+ double r = a * 1E-5;
+ r *= b;
+ r = floor(r+.5);
+
+ if (r <= 2147483647. && r >= -2147483648.)
+ return (png_fixed_point)r;
+#else
+ png_fixed_point res;
+
+ if (png_muldiv(&res, a, b, 100000) != 0)
+ return res;
+#endif
+
+ return 0; /* overflow */
+}
+#endif /* 16BIT */
+
+/* The inverse of the above. */
+png_fixed_point
+png_reciprocal2(png_fixed_point a, png_fixed_point b)
+{
+ /* The required result is 1/a * 1/b; the following preserves accuracy. */
+#ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED
+ if (a != 0 && b != 0)
+ {
+ double r = 1E15/a;
+ r /= b;
+ r = floor(r+.5);
+
+ if (r <= 2147483647. && r >= -2147483648.)
+ return (png_fixed_point)r;
+ }
+#else
+ /* This may overflow because the range of png_fixed_point isn't symmetric,
+ * but this API is only used for the product of file and screen gamma so it
+ * doesn't matter that the smallest number it can produce is 1/21474, not
+ * 1/100000
+ */
+ png_fixed_point res = png_product2(a, b);
+
+ if (res != 0)
+ return png_reciprocal(res);
+#endif
+
+ return 0; /* overflow */
+}
+#endif /* READ_GAMMA */
+
+#ifdef PNG_READ_GAMMA_SUPPORTED /* gamma table code */
+#ifndef PNG_FLOATING_ARITHMETIC_SUPPORTED
+/* Fixed point gamma.
+ *
+ * The code to calculate the tables used below can be found in the shell script
+ * contrib/tools/intgamma.sh
+ *
+ * To calculate gamma this code implements fast log() and exp() calls using only
+ * fixed point arithmetic. This code has sufficient precision for either 8-bit
+ * or 16-bit sample values.
+ *
+ * The tables used here were calculated using simple 'bc' programs, but C double
+ * precision floating point arithmetic would work fine.
+ *
+ * 8-bit log table
+ * This is a table of -log(value/255)/log(2) for 'value' in the range 128 to
+ * 255, so it's the base 2 logarithm of a normalized 8-bit floating point
+ * mantissa. The numbers are 32-bit fractions.
+ */
+static const png_uint_32
+png_8bit_l2[128] =
+{
+ 4270715492U, 4222494797U, 4174646467U, 4127164793U, 4080044201U, 4033279239U,
+ 3986864580U, 3940795015U, 3895065449U, 3849670902U, 3804606499U, 3759867474U,
+ 3715449162U, 3671346997U, 3627556511U, 3584073329U, 3540893168U, 3498011834U,
+ 3455425220U, 3413129301U, 3371120137U, 3329393864U, 3287946700U, 3246774933U,
+ 3205874930U, 3165243125U, 3124876025U, 3084770202U, 3044922296U, 3005329011U,
+ 2965987113U, 2926893432U, 2888044853U, 2849438323U, 2811070844U, 2772939474U,
+ 2735041326U, 2697373562U, 2659933400U, 2622718104U, 2585724991U, 2548951424U,
+ 2512394810U, 2476052606U, 2439922311U, 2404001468U, 2368287663U, 2332778523U,
+ 2297471715U, 2262364947U, 2227455964U, 2192742551U, 2158222529U, 2123893754U,
+ 2089754119U, 2055801552U, 2022034013U, 1988449497U, 1955046031U, 1921821672U,
+ 1888774511U, 1855902668U, 1823204291U, 1790677560U, 1758320682U, 1726131893U,
+ 1694109454U, 1662251657U, 1630556815U, 1599023271U, 1567649391U, 1536433567U,
+ 1505374214U, 1474469770U, 1443718700U, 1413119487U, 1382670639U, 1352370686U,
+ 1322218179U, 1292211689U, 1262349810U, 1232631153U, 1203054352U, 1173618059U,
+ 1144320946U, 1115161701U, 1086139034U, 1057251672U, 1028498358U, 999877854U,
+ 971388940U, 943030410U, 914801076U, 886699767U, 858725327U, 830876614U,
+ 803152505U, 775551890U, 748073672U, 720716771U, 693480120U, 666362667U,
+ 639363374U, 612481215U, 585715177U, 559064263U, 532527486U, 506103872U,
+ 479792461U, 453592303U, 427502463U, 401522014U, 375650043U, 349885648U,
+ 324227938U, 298676034U, 273229066U, 247886176U, 222646516U, 197509248U,
+ 172473545U, 147538590U, 122703574U, 97967701U, 73330182U, 48790236U,
+ 24347096U, 0U
+
+#if 0
+ /* The following are the values for 16-bit tables - these work fine for the
+ * 8-bit conversions but produce very slightly larger errors in the 16-bit
+ * log (about 1.2 as opposed to 0.7 absolute error in the final value). To
+ * use these all the shifts below must be adjusted appropriately.
+ */
+ 65166, 64430, 63700, 62976, 62257, 61543, 60835, 60132, 59434, 58741, 58054,
+ 57371, 56693, 56020, 55352, 54689, 54030, 53375, 52726, 52080, 51439, 50803,
+ 50170, 49542, 48918, 48298, 47682, 47070, 46462, 45858, 45257, 44661, 44068,
+ 43479, 42894, 42312, 41733, 41159, 40587, 40020, 39455, 38894, 38336, 37782,
+ 37230, 36682, 36137, 35595, 35057, 34521, 33988, 33459, 32932, 32408, 31887,
+ 31369, 30854, 30341, 29832, 29325, 28820, 28319, 27820, 27324, 26830, 26339,
+ 25850, 25364, 24880, 24399, 23920, 23444, 22970, 22499, 22029, 21562, 21098,
+ 20636, 20175, 19718, 19262, 18808, 18357, 17908, 17461, 17016, 16573, 16132,
+ 15694, 15257, 14822, 14390, 13959, 13530, 13103, 12678, 12255, 11834, 11415,
+ 10997, 10582, 10168, 9756, 9346, 8937, 8531, 8126, 7723, 7321, 6921, 6523,
+ 6127, 5732, 5339, 4947, 4557, 4169, 3782, 3397, 3014, 2632, 2251, 1872, 1495,
+ 1119, 744, 372
+#endif
+};
+
+static png_int_32
+png_log8bit(unsigned int x)
+{
+ unsigned int lg2 = 0;
+ /* Each time 'x' is multiplied by 2, 1 must be subtracted off the final log,
+ * because the log is actually negate that means adding 1. The final
+ * returned value thus has the range 0 (for 255 input) to 7.994 (for 1
+ * input), return -1 for the overflow (log 0) case, - so the result is
+ * always at most 19 bits.
+ */
+ if ((x &= 0xff) == 0)
+ return -1;
+
+ if ((x & 0xf0) == 0)
+ lg2 = 4, x <<= 4;
+
+ if ((x & 0xc0) == 0)
+ lg2 += 2, x <<= 2;
+
+ if ((x & 0x80) == 0)
+ lg2 += 1, x <<= 1;
+
+ /* result is at most 19 bits, so this cast is safe: */
+ return (png_int_32)((lg2 << 16) + ((png_8bit_l2[x-128]+32768)>>16));
+}
+
+/* The above gives exact (to 16 binary places) log2 values for 8-bit images,
+ * for 16-bit images we use the most significant 8 bits of the 16-bit value to
+ * get an approximation then multiply the approximation by a correction factor
+ * determined by the remaining up to 8 bits. This requires an additional step
+ * in the 16-bit case.
+ *
+ * We want log2(value/65535), we have log2(v'/255), where:
+ *
+ * value = v' * 256 + v''
+ * = v' * f
+ *
+ * So f is value/v', which is equal to (256+v''/v') since v' is in the range 128
+ * to 255 and v'' is in the range 0 to 255 f will be in the range 256 to less
+ * than 258. The final factor also needs to correct for the fact that our 8-bit
+ * value is scaled by 255, whereas the 16-bit values must be scaled by 65535.
+ *
+ * This gives a final formula using a calculated value 'x' which is value/v' and
+ * scaling by 65536 to match the above table:
+ *
+ * log2(x/257) * 65536
+ *
+ * Since these numbers are so close to '1' we can use simple linear
+ * interpolation between the two end values 256/257 (result -368.61) and 258/257
+ * (result 367.179). The values used below are scaled by a further 64 to give
+ * 16-bit precision in the interpolation:
+ *
+ * Start (256): -23591
+ * Zero (257): 0
+ * End (258): 23499
+ */
+#ifdef PNG_16BIT_SUPPORTED
+static png_int_32
+png_log16bit(png_uint_32 x)
+{
+ unsigned int lg2 = 0;
+
+ /* As above, but now the input has 16 bits. */
+ if ((x &= 0xffff) == 0)
+ return -1;
+
+ if ((x & 0xff00) == 0)
+ lg2 = 8, x <<= 8;
+
+ if ((x & 0xf000) == 0)
+ lg2 += 4, x <<= 4;
+
+ if ((x & 0xc000) == 0)
+ lg2 += 2, x <<= 2;
+
+ if ((x & 0x8000) == 0)
+ lg2 += 1, x <<= 1;
+
+ /* Calculate the base logarithm from the top 8 bits as a 28-bit fractional
+ * value.
+ */
+ lg2 <<= 28;
+ lg2 += (png_8bit_l2[(x>>8)-128]+8) >> 4;
+
+ /* Now we need to interpolate the factor, this requires a division by the top
+ * 8 bits. Do this with maximum precision.
+ */
+ x = ((x << 16) + (x >> 9)) / (x >> 8);
+
+ /* Since we divided by the top 8 bits of 'x' there will be a '1' at 1<<24,
+ * the value at 1<<16 (ignoring this) will be 0 or 1; this gives us exactly
+ * 16 bits to interpolate to get the low bits of the result. Round the
+ * answer. Note that the end point values are scaled by 64 to retain overall
+ * precision and that 'lg2' is current scaled by an extra 12 bits, so adjust
+ * the overall scaling by 6-12. Round at every step.
+ */
+ x -= 1U << 24;
+
+ if (x <= 65536U) /* <= '257' */
+ lg2 += ((23591U * (65536U-x)) + (1U << (16+6-12-1))) >> (16+6-12);
+
+ else
+ lg2 -= ((23499U * (x-65536U)) + (1U << (16+6-12-1))) >> (16+6-12);
+
+ /* Safe, because the result can't have more than 20 bits: */
+ return (png_int_32)((lg2 + 2048) >> 12);
+}
+#endif /* 16BIT */
+
+/* The 'exp()' case must invert the above, taking a 20-bit fixed point
+ * logarithmic value and returning a 16 or 8-bit number as appropriate. In
+ * each case only the low 16 bits are relevant - the fraction - since the
+ * integer bits (the top 4) simply determine a shift.
+ *
+ * The worst case is the 16-bit distinction between 65535 and 65534. This
+ * requires perhaps spurious accuracy in the decoding of the logarithm to
+ * distinguish log2(65535/65534.5) - 10^-5 or 17 bits. There is little chance
+ * of getting this accuracy in practice.
+ *
+ * To deal with this the following exp() function works out the exponent of the
+ * frational part of the logarithm by using an accurate 32-bit value from the
+ * top four fractional bits then multiplying in the remaining bits.
+ */
+static const png_uint_32
+png_32bit_exp[16] =
+{
+ /* NOTE: the first entry is deliberately set to the maximum 32-bit value. */
+ 4294967295U, 4112874773U, 3938502376U, 3771522796U, 3611622603U, 3458501653U,
+ 3311872529U, 3171459999U, 3037000500U, 2908241642U, 2784941738U, 2666869345U,
+ 2553802834U, 2445529972U, 2341847524U, 2242560872U
+};
+
+/* Adjustment table; provided to explain the numbers in the code below. */
+#if 0
+for (i=11;i>=0;--i){ print i, " ", (1 - e(-(2^i)/65536*l(2))) * 2^(32-i), "\n"}
+ 11 44937.64284865548751208448
+ 10 45180.98734845585101160448
+ 9 45303.31936980687359311872
+ 8 45364.65110595323018870784
+ 7 45395.35850361789624614912
+ 6 45410.72259715102037508096
+ 5 45418.40724413220722311168
+ 4 45422.25021786898173001728
+ 3 45424.17186732298419044352
+ 2 45425.13273269940811464704
+ 1 45425.61317555035558641664
+ 0 45425.85339951654943850496
+#endif
+
+static png_uint_32
+png_exp(png_fixed_point x)
+{
+ if (x > 0 && x <= 0xfffff) /* Else overflow or zero (underflow) */
+ {
+ /* Obtain a 4-bit approximation */
+ png_uint_32 e = png_32bit_exp[(x >> 12) & 0x0f];
+
+ /* Incorporate the low 12 bits - these decrease the returned value by
+ * multiplying by a number less than 1 if the bit is set. The multiplier
+ * is determined by the above table and the shift. Notice that the values
+ * converge on 45426 and this is used to allow linear interpolation of the
+ * low bits.
+ */
+ if (x & 0x800)
+ e -= (((e >> 16) * 44938U) + 16U) >> 5;
+
+ if (x & 0x400)
+ e -= (((e >> 16) * 45181U) + 32U) >> 6;
+
+ if (x & 0x200)
+ e -= (((e >> 16) * 45303U) + 64U) >> 7;
+
+ if (x & 0x100)
+ e -= (((e >> 16) * 45365U) + 128U) >> 8;
+
+ if (x & 0x080)
+ e -= (((e >> 16) * 45395U) + 256U) >> 9;
+
+ if (x & 0x040)
+ e -= (((e >> 16) * 45410U) + 512U) >> 10;
+
+ /* And handle the low 6 bits in a single block. */
+ e -= (((e >> 16) * 355U * (x & 0x3fU)) + 256U) >> 9;
+
+ /* Handle the upper bits of x. */
+ e >>= x >> 16;
+ return e;
+ }
+
+ /* Check for overflow */
+ if (x <= 0)
+ return png_32bit_exp[0];
+
+ /* Else underflow */
+ return 0;
+}
+
+static png_byte
+png_exp8bit(png_fixed_point lg2)
+{
+ /* Get a 32-bit value: */
+ png_uint_32 x = png_exp(lg2);
+
+ /* Convert the 32-bit value to 0..255 by multiplying by 256-1. Note that the
+ * second, rounding, step can't overflow because of the first, subtraction,
+ * step.
+ */
+ x -= x >> 8;
+ return (png_byte)(((x + 0x7fffffU) >> 24) & 0xff);
+}
+
+#ifdef PNG_16BIT_SUPPORTED
+static png_uint_16
+png_exp16bit(png_fixed_point lg2)
+{
+ /* Get a 32-bit value: */
+ png_uint_32 x = png_exp(lg2);
+
+ /* Convert the 32-bit value to 0..65535 by multiplying by 65536-1: */
+ x -= x >> 16;
+ return (png_uint_16)((x + 32767U) >> 16);
+}
+#endif /* 16BIT */
+#endif /* FLOATING_ARITHMETIC */
+
+png_byte
+png_gamma_8bit_correct(unsigned int value, png_fixed_point gamma_val)
+{
+ if (value > 0 && value < 255)
+ {
+# ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED
+ /* 'value' is unsigned, ANSI-C90 requires the compiler to correctly
+ * convert this to a floating point value. This includes values that
+ * would overflow if 'value' were to be converted to 'int'.
+ *
+ * Apparently GCC, however, does an intermediate conversion to (int)
+ * on some (ARM) but not all (x86) platforms, possibly because of
+ * hardware FP limitations. (E.g. if the hardware conversion always
+ * assumes the integer register contains a signed value.) This results
+ * in ANSI-C undefined behavior for large values.
+ *
+ * Other implementations on the same machine might actually be ANSI-C90
+ * conformant and therefore compile spurious extra code for the large
+ * values.
+ *
+ * We can be reasonably sure that an unsigned to float conversion
+ * won't be faster than an int to float one. Therefore this code
+ * assumes responsibility for the undefined behavior, which it knows
+ * can't happen because of the check above.
+ *
+ * Note the argument to this routine is an (unsigned int) because, on
+ * 16-bit platforms, it is assigned a value which might be out of
+ * range for an (int); that would result in undefined behavior in the
+ * caller if the *argument* ('value') were to be declared (int).
+ */
+ double r = floor(255*pow((int)/*SAFE*/value/255.,gamma_val*.00001)+.5);
+ return (png_byte)r;
+# else
+ png_int_32 lg2 = png_log8bit(value);
+ png_fixed_point res;
+
+ if (png_muldiv(&res, gamma_val, lg2, PNG_FP_1) != 0)
+ return png_exp8bit(res);
+
+ /* Overflow. */
+ value = 0;
+# endif
+ }
+
+ return (png_byte)(value & 0xff);
+}
+
+#ifdef PNG_16BIT_SUPPORTED
+png_uint_16
+png_gamma_16bit_correct(unsigned int value, png_fixed_point gamma_val)
+{
+ if (value > 0 && value < 65535)
+ {
+# ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED
+ /* The same (unsigned int)->(double) constraints apply here as above,
+ * however in this case the (unsigned int) to (int) conversion can
+ * overflow on an ANSI-C90 compliant system so the cast needs to ensure
+ * that this is not possible.
+ */
+ double r = floor(65535*pow((png_int_32)value/65535.,
+ gamma_val*.00001)+.5);
+ return (png_uint_16)r;
+# else
+ png_int_32 lg2 = png_log16bit(value);
+ png_fixed_point res;
+
+ if (png_muldiv(&res, gamma_val, lg2, PNG_FP_1) != 0)
+ return png_exp16bit(res);
+
+ /* Overflow. */
+ value = 0;
+# endif
+ }
+
+ return (png_uint_16)value;
+}
+#endif /* 16BIT */
+
+/* This does the right thing based on the bit_depth field of the
+ * png_struct, interpreting values as 8-bit or 16-bit. While the result
+ * is nominally a 16-bit value if bit depth is 8 then the result is
+ * 8-bit (as are the arguments.)
+ */
+png_uint_16 /* PRIVATE */
+png_gamma_correct(png_structrp png_ptr, unsigned int value,
+ png_fixed_point gamma_val)
+{
+ if (png_ptr->bit_depth == 8)
+ return png_gamma_8bit_correct(value, gamma_val);
+
+#ifdef PNG_16BIT_SUPPORTED
+ else
+ return png_gamma_16bit_correct(value, gamma_val);
+#else
+ /* should not reach this */
+ return 0;
+#endif /* 16BIT */
+}
+
+#ifdef PNG_16BIT_SUPPORTED
+/* Internal function to build a single 16-bit table - the table consists of
+ * 'num' 256 entry subtables, where 'num' is determined by 'shift' - the amount
+ * to shift the input values right (or 16-number_of_signifiant_bits).
+ *
+ * The caller is responsible for ensuring that the table gets cleaned up on
+ * png_error (i.e. if one of the mallocs below fails) - i.e. the *table argument
+ * should be somewhere that will be cleaned.
+ */
+static void
+png_build_16bit_table(png_structrp png_ptr, png_uint_16pp *ptable,
+ PNG_CONST unsigned int shift, PNG_CONST png_fixed_point gamma_val)
+{
+ /* Various values derived from 'shift': */
+ PNG_CONST unsigned int num = 1U << (8U - shift);
+#ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED
+ /* CSE the division and work round wacky GCC warnings (see the comments
+ * in png_gamma_8bit_correct for where these come from.)
+ */
+ PNG_CONST double fmax = 1./(((png_int_32)1 << (16U - shift))-1);
+#endif
+ PNG_CONST unsigned int max = (1U << (16U - shift))-1U;
+ PNG_CONST unsigned int max_by_2 = 1U << (15U-shift);
+ unsigned int i;
+
+ png_uint_16pp table = *ptable =
+ (png_uint_16pp)png_calloc(png_ptr, num * (sizeof (png_uint_16p)));
+
+ for (i = 0; i < num; i++)
+ {
+ png_uint_16p sub_table = table[i] =
+ (png_uint_16p)png_malloc(png_ptr, 256 * (sizeof (png_uint_16)));
+
+ /* The 'threshold' test is repeated here because it can arise for one of
+ * the 16-bit tables even if the others don't hit it.
+ */
+ if (png_gamma_significant(gamma_val) != 0)
+ {
+ /* The old code would overflow at the end and this would cause the
+ * 'pow' function to return a result >1, resulting in an
+ * arithmetic error. This code follows the spec exactly; ig is
+ * the recovered input sample, it always has 8-16 bits.
+ *
+ * We want input * 65535/max, rounded, the arithmetic fits in 32
+ * bits (unsigned) so long as max <= 32767.
+ */
+ unsigned int j;
+ for (j = 0; j < 256; j++)
+ {
+ png_uint_32 ig = (j << (8-shift)) + i;
+# ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED
+ /* Inline the 'max' scaling operation: */
+ /* See png_gamma_8bit_correct for why the cast to (int) is
+ * required here.
+ */
+ double d = floor(65535.*pow(ig*fmax, gamma_val*.00001)+.5);
+ sub_table[j] = (png_uint_16)d;
+# else
+ if (shift != 0)
+ ig = (ig * 65535U + max_by_2)/max;
+
+ sub_table[j] = png_gamma_16bit_correct(ig, gamma_val);
+# endif
+ }
+ }
+ else
+ {
+ /* We must still build a table, but do it the fast way. */
+ unsigned int j;
+
+ for (j = 0; j < 256; j++)
+ {
+ png_uint_32 ig = (j << (8-shift)) + i;
+
+ if (shift != 0)
+ ig = (ig * 65535U + max_by_2)/max;
+
+ sub_table[j] = (png_uint_16)ig;
+ }
+ }
+ }
+}
+
+/* NOTE: this function expects the *inverse* of the overall gamma transformation
+ * required.
+ */
+static void
+png_build_16to8_table(png_structrp png_ptr, png_uint_16pp *ptable,
+ PNG_CONST unsigned int shift, PNG_CONST png_fixed_point gamma_val)
+{
+ PNG_CONST unsigned int num = 1U << (8U - shift);
+ PNG_CONST unsigned int max = (1U << (16U - shift))-1U;
+ unsigned int i;
+ png_uint_32 last;
+
+ png_uint_16pp table = *ptable =
+ (png_uint_16pp)png_calloc(png_ptr, num * (sizeof (png_uint_16p)));
+
+ /* 'num' is the number of tables and also the number of low bits of low
+ * bits of the input 16-bit value used to select a table. Each table is
+ * itself indexed by the high 8 bits of the value.
+ */
+ for (i = 0; i < num; i++)
+ table[i] = (png_uint_16p)png_malloc(png_ptr,
+ 256 * (sizeof (png_uint_16)));
+
+ /* 'gamma_val' is set to the reciprocal of the value calculated above, so
+ * pow(out,g) is an *input* value. 'last' is the last input value set.
+ *
+ * In the loop 'i' is used to find output values. Since the output is
+ * 8-bit there are only 256 possible values. The tables are set up to
+ * select the closest possible output value for each input by finding
+ * the input value at the boundary between each pair of output values
+ * and filling the table up to that boundary with the lower output
+ * value.
+ *
+ * The boundary values are 0.5,1.5..253.5,254.5. Since these are 9-bit
+ * values the code below uses a 16-bit value in i; the values start at
+ * 128.5 (for 0.5) and step by 257, for a total of 254 values (the last
+ * entries are filled with 255). Start i at 128 and fill all 'last'
+ * table entries <= 'max'
+ */
+ last = 0;
+ for (i = 0; i < 255; ++i) /* 8-bit output value */
+ {
+ /* Find the corresponding maximum input value */
+ png_uint_16 out = (png_uint_16)(i * 257U); /* 16-bit output value */
+
+ /* Find the boundary value in 16 bits: */
+ png_uint_32 bound = png_gamma_16bit_correct(out+128U, gamma_val);
+
+ /* Adjust (round) to (16-shift) bits: */
+ bound = (bound * max + 32768U)/65535U + 1U;
+
+ while (last < bound)
+ {
+ table[last & (0xffU >> shift)][last >> (8U - shift)] = out;
+ last++;
+ }
+ }
+
+ /* And fill in the final entries. */
+ while (last < (num << 8))
+ {
+ table[last & (0xff >> shift)][last >> (8U - shift)] = 65535U;
+ last++;
+ }
+}
+#endif /* 16BIT */
+
+/* Build a single 8-bit table: same as the 16-bit case but much simpler (and
+ * typically much faster). Note that libpng currently does no sBIT processing
+ * (apparently contrary to the spec) so a 256-entry table is always generated.
+ */
+static void
+png_build_8bit_table(png_structrp png_ptr, png_bytepp ptable,
+ PNG_CONST png_fixed_point gamma_val)
+{
+ unsigned int i;
+ png_bytep table = *ptable = (png_bytep)png_malloc(png_ptr, 256);
+
+ if (png_gamma_significant(gamma_val) != 0)
+ for (i=0; i<256; i++)
+ table[i] = png_gamma_8bit_correct(i, gamma_val);
+
+ else
+ for (i=0; i<256; ++i)
+ table[i] = (png_byte)(i & 0xff);
+}
+
+/* Used from png_read_destroy and below to release the memory used by the gamma
+ * tables.
+ */
+void /* PRIVATE */
+png_destroy_gamma_table(png_structrp png_ptr)
+{
+ png_free(png_ptr, png_ptr->gamma_table);
+ png_ptr->gamma_table = NULL;
+
+#ifdef PNG_16BIT_SUPPORTED
+ if (png_ptr->gamma_16_table != NULL)
+ {
+ int i;
+ int istop = (1 << (8 - png_ptr->gamma_shift));
+ for (i = 0; i < istop; i++)
+ {
+ png_free(png_ptr, png_ptr->gamma_16_table[i]);
+ }
+ png_free(png_ptr, png_ptr->gamma_16_table);
+ png_ptr->gamma_16_table = NULL;
+ }
+#endif /* 16BIT */
+
+#if defined(PNG_READ_BACKGROUND_SUPPORTED) || \
+ defined(PNG_READ_ALPHA_MODE_SUPPORTED) || \
+ defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
+ png_free(png_ptr, png_ptr->gamma_from_1);
+ png_ptr->gamma_from_1 = NULL;
+ png_free(png_ptr, png_ptr->gamma_to_1);
+ png_ptr->gamma_to_1 = NULL;
+
+#ifdef PNG_16BIT_SUPPORTED
+ if (png_ptr->gamma_16_from_1 != NULL)
+ {
+ int i;
+ int istop = (1 << (8 - png_ptr->gamma_shift));
+ for (i = 0; i < istop; i++)
+ {
+ png_free(png_ptr, png_ptr->gamma_16_from_1[i]);
+ }
+ png_free(png_ptr, png_ptr->gamma_16_from_1);
+ png_ptr->gamma_16_from_1 = NULL;
+ }
+ if (png_ptr->gamma_16_to_1 != NULL)
+ {
+ int i;
+ int istop = (1 << (8 - png_ptr->gamma_shift));
+ for (i = 0; i < istop; i++)
+ {
+ png_free(png_ptr, png_ptr->gamma_16_to_1[i]);
+ }
+ png_free(png_ptr, png_ptr->gamma_16_to_1);
+ png_ptr->gamma_16_to_1 = NULL;
+ }
+#endif /* 16BIT */
+#endif /* READ_BACKGROUND || READ_ALPHA_MODE || RGB_TO_GRAY */
+}
+
+/* We build the 8- or 16-bit gamma tables here. Note that for 16-bit
+ * tables, we don't make a full table if we are reducing to 8-bit in
+ * the future. Note also how the gamma_16 tables are segmented so that
+ * we don't need to allocate > 64K chunks for a full 16-bit table.
+ */
+void /* PRIVATE */
+png_build_gamma_table(png_structrp png_ptr, int bit_depth)
+{
+ png_debug(1, "in png_build_gamma_table");
+
+ /* Remove any existing table; this copes with multiple calls to
+ * png_read_update_info. The warning is because building the gamma tables
+ * multiple times is a performance hit - it's harmless but the ability to call
+ * png_read_update_info() multiple times is new in 1.5.6 so it seems sensible
+ * to warn if the app introduces such a hit.
+ */
+ if (png_ptr->gamma_table != NULL || png_ptr->gamma_16_table != NULL)
+ {
+ png_warning(png_ptr, "gamma table being rebuilt");
+ png_destroy_gamma_table(png_ptr);
+ }
+
+ if (bit_depth <= 8)
+ {
+ png_build_8bit_table(png_ptr, &png_ptr->gamma_table,
+ png_ptr->screen_gamma > 0 ? png_reciprocal2(png_ptr->colorspace.gamma,
+ png_ptr->screen_gamma) : PNG_FP_1);
+
+#if defined(PNG_READ_BACKGROUND_SUPPORTED) || \
+ defined(PNG_READ_ALPHA_MODE_SUPPORTED) || \
+ defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
+ if ((png_ptr->transformations & (PNG_COMPOSE | PNG_RGB_TO_GRAY)) != 0)
+ {
+ png_build_8bit_table(png_ptr, &png_ptr->gamma_to_1,
+ png_reciprocal(png_ptr->colorspace.gamma));
+
+ png_build_8bit_table(png_ptr, &png_ptr->gamma_from_1,
+ png_ptr->screen_gamma > 0 ? png_reciprocal(png_ptr->screen_gamma) :
+ png_ptr->colorspace.gamma/* Probably doing rgb_to_gray */);
+ }
+#endif /* READ_BACKGROUND || READ_ALPHA_MODE || RGB_TO_GRAY */
+ }
+#ifdef PNG_16BIT_SUPPORTED
+ else
+ {
+ png_byte shift, sig_bit;
+
+ if ((png_ptr->color_type & PNG_COLOR_MASK_COLOR) != 0)
+ {
+ sig_bit = png_ptr->sig_bit.red;
+
+ if (png_ptr->sig_bit.green > sig_bit)
+ sig_bit = png_ptr->sig_bit.green;
+
+ if (png_ptr->sig_bit.blue > sig_bit)
+ sig_bit = png_ptr->sig_bit.blue;
+ }
+ else
+ sig_bit = png_ptr->sig_bit.gray;
+
+ /* 16-bit gamma code uses this equation:
+ *
+ * ov = table[(iv & 0xff) >> gamma_shift][iv >> 8]
+ *
+ * Where 'iv' is the input color value and 'ov' is the output value -
+ * pow(iv, gamma).
+ *
+ * Thus the gamma table consists of up to 256 256-entry tables. The table
+ * is selected by the (8-gamma_shift) most significant of the low 8 bits of
+ * the color value then indexed by the upper 8 bits:
+ *
+ * table[low bits][high 8 bits]
+ *
+ * So the table 'n' corresponds to all those 'iv' of:
+ *
+ * <all high 8-bit values><n << gamma_shift>..<(n+1 << gamma_shift)-1>
+ *
+ */
+ if (sig_bit > 0 && sig_bit < 16U)
+ /* shift == insignificant bits */
+ shift = (png_byte)((16U - sig_bit) & 0xff);
+
+ else
+ shift = 0; /* keep all 16 bits */
+
+ if ((png_ptr->transformations & (PNG_16_TO_8 | PNG_SCALE_16_TO_8)) != 0)
+ {
+ /* PNG_MAX_GAMMA_8 is the number of bits to keep - effectively
+ * the significant bits in the *input* when the output will
+ * eventually be 8 bits. By default it is 11.
+ */
+ if (shift < (16U - PNG_MAX_GAMMA_8))
+ shift = (16U - PNG_MAX_GAMMA_8);
+ }
+
+ if (shift > 8U)
+ shift = 8U; /* Guarantees at least one table! */
+
+ png_ptr->gamma_shift = shift;
+
+ /* NOTE: prior to 1.5.4 this test used to include PNG_BACKGROUND (now
+ * PNG_COMPOSE). This effectively smashed the background calculation for
+ * 16-bit output because the 8-bit table assumes the result will be reduced
+ * to 8 bits.
+ */
+ if ((png_ptr->transformations & (PNG_16_TO_8 | PNG_SCALE_16_TO_8)) != 0)
+ png_build_16to8_table(png_ptr, &png_ptr->gamma_16_table, shift,
+ png_ptr->screen_gamma > 0 ? png_product2(png_ptr->colorspace.gamma,
+ png_ptr->screen_gamma) : PNG_FP_1);
+
+ else
+ png_build_16bit_table(png_ptr, &png_ptr->gamma_16_table, shift,
+ png_ptr->screen_gamma > 0 ? png_reciprocal2(png_ptr->colorspace.gamma,
+ png_ptr->screen_gamma) : PNG_FP_1);
+
+#if defined(PNG_READ_BACKGROUND_SUPPORTED) || \
+ defined(PNG_READ_ALPHA_MODE_SUPPORTED) || \
+ defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
+ if ((png_ptr->transformations & (PNG_COMPOSE | PNG_RGB_TO_GRAY)) != 0)
+ {
+ png_build_16bit_table(png_ptr, &png_ptr->gamma_16_to_1, shift,
+ png_reciprocal(png_ptr->colorspace.gamma));
+
+ /* Notice that the '16 from 1' table should be full precision, however
+ * the lookup on this table still uses gamma_shift, so it can't be.
+ * TODO: fix this.
+ */
+ png_build_16bit_table(png_ptr, &png_ptr->gamma_16_from_1, shift,
+ png_ptr->screen_gamma > 0 ? png_reciprocal(png_ptr->screen_gamma) :
+ png_ptr->colorspace.gamma/* Probably doing rgb_to_gray */);
+ }
+#endif /* READ_BACKGROUND || READ_ALPHA_MODE || RGB_TO_GRAY */
+ }
+#endif /* 16BIT */
+}
+#endif /* READ_GAMMA */
+
+/* HARDWARE OR SOFTWARE OPTION SUPPORT */
+#ifdef PNG_SET_OPTION_SUPPORTED
+int PNGAPI
+png_set_option(png_structrp png_ptr, int option, int onoff)
+{
+ if (png_ptr != NULL && option >= 0 && option < PNG_OPTION_NEXT &&
+ (option & 1) == 0)
+ {
+ int mask = 3 << option;
+ int setting = (2 + (onoff != 0)) << option;
+ int current = png_ptr->options;
+
+ png_ptr->options = (png_byte)(((current & ~mask) | setting) & 0xff);
+
+ return (current & mask) >> option;
+ }
+
+ return PNG_OPTION_INVALID;
+}
+#endif
+
+/* sRGB support */
+#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) ||\
+ defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
+/* sRGB conversion tables; these are machine generated with the code in
+ * contrib/tools/makesRGB.c. The actual sRGB transfer curve defined in the
+ * specification (see the article at http://en.wikipedia.org/wiki/SRGB)
+ * is used, not the gamma=1/2.2 approximation use elsewhere in libpng.
+ * The sRGB to linear table is exact (to the nearest 16-bit linear fraction).
+ * The inverse (linear to sRGB) table has accuracies as follows:
+ *
+ * For all possible (255*65535+1) input values:
+ *
+ * error: -0.515566 - 0.625971, 79441 (0.475369%) of readings inexact
+ *
+ * For the input values corresponding to the 65536 16-bit values:
+ *
+ * error: -0.513727 - 0.607759, 308 (0.469978%) of readings inexact
+ *
+ * In all cases the inexact readings are only off by one.
+ */
+
+#ifdef PNG_SIMPLIFIED_READ_SUPPORTED
+/* The convert-to-sRGB table is only currently required for read. */
+const png_uint_16 png_sRGB_table[256] =
+{
+ 0,20,40,60,80,99,119,139,
+ 159,179,199,219,241,264,288,313,
+ 340,367,396,427,458,491,526,562,
+ 599,637,677,718,761,805,851,898,
+ 947,997,1048,1101,1156,1212,1270,1330,
+ 1391,1453,1517,1583,1651,1720,1790,1863,
+ 1937,2013,2090,2170,2250,2333,2418,2504,
+ 2592,2681,2773,2866,2961,3058,3157,3258,
+ 3360,3464,3570,3678,3788,3900,4014,4129,
+ 4247,4366,4488,4611,4736,4864,4993,5124,
+ 5257,5392,5530,5669,5810,5953,6099,6246,
+ 6395,6547,6700,6856,7014,7174,7335,7500,
+ 7666,7834,8004,8177,8352,8528,8708,8889,
+ 9072,9258,9445,9635,9828,10022,10219,10417,
+ 10619,10822,11028,11235,11446,11658,11873,12090,
+ 12309,12530,12754,12980,13209,13440,13673,13909,
+ 14146,14387,14629,14874,15122,15371,15623,15878,
+ 16135,16394,16656,16920,17187,17456,17727,18001,
+ 18277,18556,18837,19121,19407,19696,19987,20281,
+ 20577,20876,21177,21481,21787,22096,22407,22721,
+ 23038,23357,23678,24002,24329,24658,24990,25325,
+ 25662,26001,26344,26688,27036,27386,27739,28094,
+ 28452,28813,29176,29542,29911,30282,30656,31033,
+ 31412,31794,32179,32567,32957,33350,33745,34143,
+ 34544,34948,35355,35764,36176,36591,37008,37429,
+ 37852,38278,38706,39138,39572,40009,40449,40891,
+ 41337,41785,42236,42690,43147,43606,44069,44534,
+ 45002,45473,45947,46423,46903,47385,47871,48359,
+ 48850,49344,49841,50341,50844,51349,51858,52369,
+ 52884,53401,53921,54445,54971,55500,56032,56567,
+ 57105,57646,58190,58737,59287,59840,60396,60955,
+ 61517,62082,62650,63221,63795,64372,64952,65535
+};
+#endif /* SIMPLIFIED_READ */
+
+/* The base/delta tables are required for both read and write (but currently
+ * only the simplified versions.)
+ */
+const png_uint_16 png_sRGB_base[512] =
+{
+ 128,1782,3383,4644,5675,6564,7357,8074,
+ 8732,9346,9921,10463,10977,11466,11935,12384,
+ 12816,13233,13634,14024,14402,14769,15125,15473,
+ 15812,16142,16466,16781,17090,17393,17690,17981,
+ 18266,18546,18822,19093,19359,19621,19879,20133,
+ 20383,20630,20873,21113,21349,21583,21813,22041,
+ 22265,22487,22707,22923,23138,23350,23559,23767,
+ 23972,24175,24376,24575,24772,24967,25160,25352,
+ 25542,25730,25916,26101,26284,26465,26645,26823,
+ 27000,27176,27350,27523,27695,27865,28034,28201,
+ 28368,28533,28697,28860,29021,29182,29341,29500,
+ 29657,29813,29969,30123,30276,30429,30580,30730,
+ 30880,31028,31176,31323,31469,31614,31758,31902,
+ 32045,32186,32327,32468,32607,32746,32884,33021,
+ 33158,33294,33429,33564,33697,33831,33963,34095,
+ 34226,34357,34486,34616,34744,34873,35000,35127,
+ 35253,35379,35504,35629,35753,35876,35999,36122,
+ 36244,36365,36486,36606,36726,36845,36964,37083,
+ 37201,37318,37435,37551,37668,37783,37898,38013,
+ 38127,38241,38354,38467,38580,38692,38803,38915,
+ 39026,39136,39246,39356,39465,39574,39682,39790,
+ 39898,40005,40112,40219,40325,40431,40537,40642,
+ 40747,40851,40955,41059,41163,41266,41369,41471,
+ 41573,41675,41777,41878,41979,42079,42179,42279,
+ 42379,42478,42577,42676,42775,42873,42971,43068,
+ 43165,43262,43359,43456,43552,43648,43743,43839,
+ 43934,44028,44123,44217,44311,44405,44499,44592,
+ 44685,44778,44870,44962,45054,45146,45238,45329,
+ 45420,45511,45601,45692,45782,45872,45961,46051,
+ 46140,46229,46318,46406,46494,46583,46670,46758,
+ 46846,46933,47020,47107,47193,47280,47366,47452,
+ 47538,47623,47709,47794,47879,47964,48048,48133,
+ 48217,48301,48385,48468,48552,48635,48718,48801,
+ 48884,48966,49048,49131,49213,49294,49376,49458,
+ 49539,49620,49701,49782,49862,49943,50023,50103,
+ 50183,50263,50342,50422,50501,50580,50659,50738,
+ 50816,50895,50973,51051,51129,51207,51285,51362,
+ 51439,51517,51594,51671,51747,51824,51900,51977,
+ 52053,52129,52205,52280,52356,52432,52507,52582,
+ 52657,52732,52807,52881,52956,53030,53104,53178,
+ 53252,53326,53400,53473,53546,53620,53693,53766,
+ 53839,53911,53984,54056,54129,54201,54273,54345,
+ 54417,54489,54560,54632,54703,54774,54845,54916,
+ 54987,55058,55129,55199,55269,55340,55410,55480,
+ 55550,55620,55689,55759,55828,55898,55967,56036,
+ 56105,56174,56243,56311,56380,56448,56517,56585,
+ 56653,56721,56789,56857,56924,56992,57059,57127,
+ 57194,57261,57328,57395,57462,57529,57595,57662,
+ 57728,57795,57861,57927,57993,58059,58125,58191,
+ 58256,58322,58387,58453,58518,58583,58648,58713,
+ 58778,58843,58908,58972,59037,59101,59165,59230,
+ 59294,59358,59422,59486,59549,59613,59677,59740,
+ 59804,59867,59930,59993,60056,60119,60182,60245,
+ 60308,60370,60433,60495,60558,60620,60682,60744,
+ 60806,60868,60930,60992,61054,61115,61177,61238,
+ 61300,61361,61422,61483,61544,61605,61666,61727,
+ 61788,61848,61909,61969,62030,62090,62150,62211,
+ 62271,62331,62391,62450,62510,62570,62630,62689,
+ 62749,62808,62867,62927,62986,63045,63104,63163,
+ 63222,63281,63340,63398,63457,63515,63574,63632,
+ 63691,63749,63807,63865,63923,63981,64039,64097,
+ 64155,64212,64270,64328,64385,64443,64500,64557,
+ 64614,64672,64729,64786,64843,64900,64956,65013,
+ 65070,65126,65183,65239,65296,65352,65409,65465
+};
+
+const png_byte png_sRGB_delta[512] =
+{
+ 207,201,158,129,113,100,90,82,77,72,68,64,61,59,56,54,
+ 52,50,49,47,46,45,43,42,41,40,39,39,38,37,36,36,
+ 35,34,34,33,33,32,32,31,31,30,30,30,29,29,28,28,
+ 28,27,27,27,27,26,26,26,25,25,25,25,24,24,24,24,
+ 23,23,23,23,23,22,22,22,22,22,22,21,21,21,21,21,
+ 21,20,20,20,20,20,20,20,20,19,19,19,19,19,19,19,
+ 19,18,18,18,18,18,18,18,18,18,18,17,17,17,17,17,
+ 17,17,17,17,17,17,16,16,16,16,16,16,16,16,16,16,
+ 16,16,16,16,15,15,15,15,15,15,15,15,15,15,15,15,
+ 15,15,15,15,14,14,14,14,14,14,14,14,14,14,14,14,
+ 14,14,14,14,14,14,14,13,13,13,13,13,13,13,13,13,
+ 13,13,13,13,13,13,13,13,13,13,13,13,13,13,12,12,
+ 12,12,12,12,12,12,12,12,12,12,12,12,12,12,12,12,
+ 12,12,12,12,12,12,12,12,12,12,12,12,11,11,11,11,
+ 11,11,11,11,11,11,11,11,11,11,11,11,11,11,11,11,
+ 11,11,11,11,11,11,11,11,11,11,11,11,11,11,11,11,
+ 11,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,
+ 10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,
+ 10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,
+ 10,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,
+ 9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,
+ 9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,
+ 9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,
+ 9,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
+ 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
+ 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
+ 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
+ 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
+ 8,8,8,8,8,8,8,8,8,7,7,7,7,7,7,7,
+ 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
+ 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
+ 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7
+};
+#endif /* SIMPLIFIED READ/WRITE sRGB support */
+
+/* SIMPLIFIED READ/WRITE SUPPORT */
+#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) ||\
+ defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
+static int
+png_image_free_function(png_voidp argument)
+{
+ png_imagep image = png_voidcast(png_imagep, argument);
+ png_controlp cp = image->opaque;
+ png_control c;
+
+ /* Double check that we have a png_ptr - it should be impossible to get here
+ * without one.
+ */
+ if (cp->png_ptr == NULL)
+ return 0;
+
+ /* First free any data held in the control structure. */
+# ifdef PNG_STDIO_SUPPORTED
+ if (cp->owned_file != 0)
+ {
+ FILE *fp = png_voidcast(FILE*, cp->png_ptr->io_ptr);
+ cp->owned_file = 0;
+
+ /* Ignore errors here. */
+ if (fp != NULL)
+ {
+ cp->png_ptr->io_ptr = NULL;
+ (void)fclose(fp);
+ }
+ }
+# endif
+
+ /* Copy the control structure so that the original, allocated, version can be
+ * safely freed. Notice that a png_error here stops the remainder of the
+ * cleanup, but this is probably fine because that would indicate bad memory
+ * problems anyway.
+ */
+ c = *cp;
+ image->opaque = &c;
+ png_free(c.png_ptr, cp);
+
+ /* Then the structures, calling the correct API. */
+ if (c.for_write != 0)
+ {
+# ifdef PNG_SIMPLIFIED_WRITE_SUPPORTED
+ png_destroy_write_struct(&c.png_ptr, &c.info_ptr);
+# else
+ png_error(c.png_ptr, "simplified write not supported");
+# endif
+ }
+ else
+ {
+# ifdef PNG_SIMPLIFIED_READ_SUPPORTED
+ png_destroy_read_struct(&c.png_ptr, &c.info_ptr, NULL);
+# else
+ png_error(c.png_ptr, "simplified read not supported");
+# endif
+ }
+
+ /* Success. */
+ return 1;
+}
+
+void PNGAPI
+png_image_free(png_imagep image)
+{
+ /* Safely call the real function, but only if doing so is safe at this point
+ * (if not inside an error handling context). Otherwise assume
+ * png_safe_execute will call this API after the return.
+ */
+ if (image != NULL && image->opaque != NULL &&
+ image->opaque->error_buf == NULL)
+ {
+ /* Ignore errors here: */
+ (void)png_safe_execute(image, png_image_free_function, image);
+ image->opaque = NULL;
+ }
+}
+
+int /* PRIVATE */
+png_image_error(png_imagep image, png_const_charp error_message)
+{
+ /* Utility to log an error. */
+ png_safecat(image->message, (sizeof image->message), 0, error_message);
+ image->warning_or_error |= PNG_IMAGE_ERROR;
+ png_image_free(image);
+ return 0;
+}
+
+#endif /* SIMPLIFIED READ/WRITE */
+#endif /* READ || WRITE */
diff --git a/third_party/lpng_v163/png.h b/third_party/libpng/png.h
similarity index 78%
rename from third_party/lpng_v163/png.h
rename to third_party/libpng/png.h
index 538b561..4d03dfc 100644
--- a/third_party/lpng_v163/png.h
+++ b/third_party/libpng/png.h
@@ -1,8 +1,9 @@
/* png.h - header file for PNG reference library
*
- * libpng version 1.6.3 - July 18, 2013
- * Copyright (c) 1998-2013 Glenn Randers-Pehrson
+ * libpng version 1.6.20, December 3, 2015
+ *
+ * Copyright (c) 1998-2015 Glenn Randers-Pehrson
* (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
* (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
*
@@ -10,17 +11,137 @@
*
* Authors and maintainers:
* libpng versions 0.71, May 1995, through 0.88, January 1996: Guy Schalnat
- * libpng versions 0.89c, June 1996, through 0.96, May 1997: Andreas Dilger
- * libpng versions 0.97, January 1998, through 1.6.3 - July 18, 2013: Glenn
+ * libpng versions 0.89, June 1996, through 0.96, May 1997: Andreas Dilger
+ * libpng versions 0.97, January 1998, through 1.6.20, December 3, 2015:
+ * Glenn Randers-Pehrson.
* See also "Contributing Authors", below.
+ */
+
+/*
+ * COPYRIGHT NOTICE, DISCLAIMER, and LICENSE:
*
- * Note about libpng version numbers:
+ * If you modify libpng you may insert additional notices immediately following
+ * this sentence.
*
- * Due to various miscommunications, unforeseen code incompatibilities
- * and occasional factors outside the authors' control, version numbering
- * on the library has not always been consistent and straightforward.
- * The following table summarizes matters since version 0.89c, which was
- * the first widely used release:
+ * This code is released under the libpng license.
+ *
+ * libpng versions 1.0.7, July 1, 2000, through 1.6.20, December 3, 2015, are
+ * Copyright (c) 2000-2002, 2004, 2006-2015 Glenn Randers-Pehrson, are
+ * derived from libpng-1.0.6, and are distributed according to the same
+ * disclaimer and license as libpng-1.0.6 with the following individuals
+ * added to the list of Contributing Authors:
+ *
+ * Simon-Pierre Cadieux
+ * Eric S. Raymond
+ * Mans Rullgard
+ * Cosmin Truta
+ * Gilles Vollant
+ * James Yu
+ *
+ * and with the following additions to the disclaimer:
+ *
+ * There is no warranty against interference with your enjoyment of the
+ * library or against infringement. There is no warranty that our
+ * efforts or the library will fulfill any of your particular purposes
+ * or needs. This library is provided with all faults, and the entire
+ * risk of satisfactory quality, performance, accuracy, and effort is with
+ * the user.
+ *
+ * libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are
+ * Copyright (c) 1998-2000 Glenn Randers-Pehrson, are derived from
+ * libpng-0.96, and are distributed according to the same disclaimer and
+ * license as libpng-0.96, with the following individuals added to the list
+ * of Contributing Authors:
+ *
+ * Tom Lane
+ * Glenn Randers-Pehrson
+ * Willem van Schaik
+ *
+ * libpng versions 0.89, June 1996, through 0.96, May 1997, are
+ * Copyright (c) 1996-1997 Andreas Dilger, are derived from libpng-0.88,
+ * and are distributed according to the same disclaimer and license as
+ * libpng-0.88, with the following individuals added to the list of
+ * Contributing Authors:
+ *
+ * John Bowler
+ * Kevin Bracey
+ * Sam Bushell
+ * Magnus Holmgren
+ * Greg Roelofs
+ * Tom Tanner
+ *
+ * libpng versions 0.5, May 1995, through 0.88, January 1996, are
+ * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
+ *
+ * For the purposes of this copyright and license, "Contributing Authors"
+ * is defined as the following set of individuals:
+ *
+ * Andreas Dilger
+ * Dave Martindale
+ * Guy Eric Schalnat
+ * Paul Schmidt
+ * Tim Wegner
+ *
+ * The PNG Reference Library is supplied "AS IS". The Contributing Authors
+ * and Group 42, Inc. disclaim all warranties, expressed or implied,
+ * including, without limitation, the warranties of merchantability and of
+ * fitness for any purpose. The Contributing Authors and Group 42, Inc.
+ * assume no liability for direct, indirect, incidental, special, exemplary,
+ * or consequential damages, which may result from the use of the PNG
+ * Reference Library, even if advised of the possibility of such damage.
+ *
+ * Permission is hereby granted to use, copy, modify, and distribute this
+ * source code, or portions hereof, for any purpose, without fee, subject
+ * to the following restrictions:
+ *
+ * 1. The origin of this source code must not be misrepresented.
+ *
+ * 2. Altered versions must be plainly marked as such and must not
+ * be misrepresented as being the original source.
+ *
+ * 3. This Copyright notice may not be removed or altered from any
+ * source or altered source distribution.
+ *
+ * The Contributing Authors and Group 42, Inc. specifically permit, without
+ * fee, and encourage the use of this source code as a component to
+ * supporting the PNG file format in commercial products. If you use this
+ * source code in a product, acknowledgment is not required but would be
+ * appreciated.
+ *
+ * END OF COPYRIGHT NOTICE, DISCLAIMER, and LICENSE.
+ */
+
+/*
+ * A "png_get_copyright" function is available, for convenient use in "about"
+ * boxes and the like:
+ *
+ * printf("%s", png_get_copyright(NULL));
+ *
+ * Also, the PNG logo (in PNG format, of course) is supplied in the
+ * files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31).
+ */
+
+/*
+ * Libpng is OSI Certified Open Source Software. OSI Certified Open Source is
+ * a certification mark of the Open Source Initiative. OSI has not addressed
+ * the additional disclaimers inserted at version 1.0.7.
+ */
+
+/*
+ * The contributing authors would like to thank all those who helped
+ * with testing, bug fixes, and patience. This wouldn't have been
+ * possible without all of you.
+ *
+ * Thanks to Frank J. T. Wojcik for helping with the documentation.
+ */
+
+/* Note about libpng version numbers:
+ *
+ * Due to various miscommunications, unforeseen code incompatibilities
+ * and occasional factors outside the authors' control, version numbering
+ * on the library has not always been consistent and straightforward.
+ * The following table summarizes matters since version 0.89c, which was
+ * the first widely used release:
*
* source png.h png.h shared-lib
* version string int version
@@ -58,276 +179,48 @@
* 1.0.7beta15-18 1 10007 2.1.0.7beta15-18 (binary compatible)
* 1.0.7rc1-2 1 10007 2.1.0.7rc1-2 (binary compatible)
* 1.0.7 1 10007 (still compatible)
- * 1.0.8beta1-4 1 10008 2.1.0.8beta1-4
- * 1.0.8rc1 1 10008 2.1.0.8rc1
- * 1.0.8 1 10008 2.1.0.8
- * 1.0.9beta1-6 1 10009 2.1.0.9beta1-6
- * 1.0.9rc1 1 10009 2.1.0.9rc1
- * 1.0.9beta7-10 1 10009 2.1.0.9beta7-10
- * 1.0.9rc2 1 10009 2.1.0.9rc2
- * 1.0.9 1 10009 2.1.0.9
- * 1.0.10beta1 1 10010 2.1.0.10beta1
- * 1.0.10rc1 1 10010 2.1.0.10rc1
- * 1.0.10 1 10010 2.1.0.10
- * 1.0.11beta1-3 1 10011 2.1.0.11beta1-3
- * 1.0.11rc1 1 10011 2.1.0.11rc1
- * 1.0.11 1 10011 2.1.0.11
- * 1.0.12beta1-2 2 10012 2.1.0.12beta1-2
- * 1.0.12rc1 2 10012 2.1.0.12rc1
- * 1.0.12 2 10012 2.1.0.12
- * 1.1.0a-f - 10100 2.1.1.0a-f (branch abandoned)
- * 1.2.0beta1-2 2 10200 2.1.2.0beta1-2
- * 1.2.0beta3-5 3 10200 3.1.2.0beta3-5
- * 1.2.0rc1 3 10200 3.1.2.0rc1
- * 1.2.0 3 10200 3.1.2.0
- * 1.2.1beta1-4 3 10201 3.1.2.1beta1-4
- * 1.2.1rc1-2 3 10201 3.1.2.1rc1-2
- * 1.2.1 3 10201 3.1.2.1
- * 1.2.2beta1-6 12 10202 12.so.0.1.2.2beta1-6
- * 1.0.13beta1 10 10013 10.so.0.1.0.13beta1
- * 1.0.13rc1 10 10013 10.so.0.1.0.13rc1
- * 1.2.2rc1 12 10202 12.so.0.1.2.2rc1
- * 1.0.13 10 10013 10.so.0.1.0.13
- * 1.2.2 12 10202 12.so.0.1.2.2
- * 1.2.3rc1-6 12 10203 12.so.0.1.2.3rc1-6
- * 1.2.3 12 10203 12.so.0.1.2.3
- * 1.2.4beta1-3 13 10204 12.so.0.1.2.4beta1-3
- * 1.0.14rc1 13 10014 10.so.0.1.0.14rc1
- * 1.2.4rc1 13 10204 12.so.0.1.2.4rc1
- * 1.0.14 10 10014 10.so.0.1.0.14
- * 1.2.4 13 10204 12.so.0.1.2.4
- * 1.2.5beta1-2 13 10205 12.so.0.1.2.5beta1-2
- * 1.0.15rc1-3 10 10015 10.so.0.1.0.15rc1-3
- * 1.2.5rc1-3 13 10205 12.so.0.1.2.5rc1-3
- * 1.0.15 10 10015 10.so.0.1.0.15
- * 1.2.5 13 10205 12.so.0.1.2.5
- * 1.2.6beta1-4 13 10206 12.so.0.1.2.6beta1-4
- * 1.0.16 10 10016 10.so.0.1.0.16
- * 1.2.6 13 10206 12.so.0.1.2.6
- * 1.2.7beta1-2 13 10207 12.so.0.1.2.7beta1-2
- * 1.0.17rc1 10 10017 12.so.0.1.0.17rc1
- * 1.2.7rc1 13 10207 12.so.0.1.2.7rc1
- * 1.0.17 10 10017 12.so.0.1.0.17
- * 1.2.7 13 10207 12.so.0.1.2.7
- * 1.2.8beta1-5 13 10208 12.so.0.1.2.8beta1-5
- * 1.0.18rc1-5 10 10018 12.so.0.1.0.18rc1-5
- * 1.2.8rc1-5 13 10208 12.so.0.1.2.8rc1-5
- * 1.0.18 10 10018 12.so.0.1.0.18
- * 1.2.8 13 10208 12.so.0.1.2.8
- * 1.2.9beta1-3 13 10209 12.so.0.1.2.9beta1-3
- * 1.2.9beta4-11 13 10209 12.so.0.9[.0]
- * 1.2.9rc1 13 10209 12.so.0.9[.0]
- * 1.2.9 13 10209 12.so.0.9[.0]
- * 1.2.10beta1-7 13 10210 12.so.0.10[.0]
- * 1.2.10rc1-2 13 10210 12.so.0.10[.0]
- * 1.2.10 13 10210 12.so.0.10[.0]
- * 1.4.0beta1-5 14 10400 14.so.0.0[.0]
- * 1.2.11beta1-4 13 10211 12.so.0.11[.0]
- * 1.4.0beta7-8 14 10400 14.so.0.0[.0]
- * 1.2.11 13 10211 12.so.0.11[.0]
- * 1.2.12 13 10212 12.so.0.12[.0]
- * 1.4.0beta9-14 14 10400 14.so.0.0[.0]
- * 1.2.13 13 10213 12.so.0.13[.0]
- * 1.4.0beta15-36 14 10400 14.so.0.0[.0]
- * 1.4.0beta37-87 14 10400 14.so.14.0[.0]
- * 1.4.0rc01 14 10400 14.so.14.0[.0]
- * 1.4.0beta88-109 14 10400 14.so.14.0[.0]
- * 1.4.0rc02-08 14 10400 14.so.14.0[.0]
- * 1.4.0 14 10400 14.so.14.0[.0]
- * 1.4.1beta01-03 14 10401 14.so.14.1[.0]
- * 1.4.1rc01 14 10401 14.so.14.1[.0]
- * 1.4.1beta04-12 14 10401 14.so.14.1[.0]
- * 1.4.1 14 10401 14.so.14.1[.0]
- * 1.4.2 14 10402 14.so.14.2[.0]
- * 1.4.3 14 10403 14.so.14.3[.0]
- * 1.4.4 14 10404 14.so.14.4[.0]
- * 1.5.0beta01-58 15 10500 15.so.15.0[.0]
- * 1.5.0rc01-07 15 10500 15.so.15.0[.0]
- * 1.5.0 15 10500 15.so.15.0[.0]
- * 1.5.1beta01-11 15 10501 15.so.15.1[.0]
- * 1.5.1rc01-02 15 10501 15.so.15.1[.0]
- * 1.5.1 15 10501 15.so.15.1[.0]
- * 1.5.2beta01-03 15 10502 15.so.15.2[.0]
- * 1.5.2rc01-03 15 10502 15.so.15.2[.0]
- * 1.5.2 15 10502 15.so.15.2[.0]
- * 1.5.3beta01-10 15 10503 15.so.15.3[.0]
- * 1.5.3rc01-02 15 10503 15.so.15.3[.0]
- * 1.5.3beta11 15 10503 15.so.15.3[.0]
- * 1.5.3 [omitted]
- * 1.5.4beta01-08 15 10504 15.so.15.4[.0]
- * 1.5.4rc01 15 10504 15.so.15.4[.0]
- * 1.5.4 15 10504 15.so.15.4[.0]
- * 1.5.5beta01-08 15 10505 15.so.15.5[.0]
- * 1.5.5rc01 15 10505 15.so.15.5[.0]
- * 1.5.5 15 10505 15.so.15.5[.0]
- * 1.5.6beta01-07 15 10506 15.so.15.6[.0]
- * 1.5.6rc01-03 15 10506 15.so.15.6[.0]
- * 1.5.6 15 10506 15.so.15.6[.0]
- * 1.5.7beta01-05 15 10507 15.so.15.7[.0]
- * 1.5.7rc01-03 15 10507 15.so.15.7[.0]
- * 1.5.7 15 10507 15.so.15.7[.0]
- * 1.6.0beta01-40 16 10600 16.so.16.0[.0]
- * 1.6.0rc01-08 16 10600 16.so.16.0[.0]
- * 1.6.0 16 10600 16.so.16.0[.0]
- * 1.6.1beta01-09 16 10601 16.so.16.1[.0]
- * 1.6.1rc01 16 10601 16.so.16.1[.0]
- * 1.6.1 16 10601 16.so.16.1[.0]
- * 1.6.2beta01 16 10602 16.so.16.2[.0]
- * 1.6.2rc01-06 16 10602 16.so.16.2[.0]
- * 1.6.2 16 10602 16.so.16.2[.0]
- * 1.6.3beta01-11 16 10603 16.so.16.3[.0]
- * 1.6.3rc01 16 10603 16.so.16.3[.0]
- * 1.6.3 16 10603 16.so.16.3[.0]
+ * ...
+ * 1.0.19 10 10019 10.so.0.19[.0]
+ * ...
+ * 1.2.53 13 10253 12.so.0.53[.0]
+ * ...
+ * 1.5.23 15 10523 15.so.15.23[.0]
+ * ...
+ * 1.6.20 16 10620 16.so.16.20[.0]
*
- * Henceforth the source version will match the shared-library major
- * and minor numbers; the shared-library major version number will be
- * used for changes in backward compatibility, as it is intended. The
- * PNG_LIBPNG_VER macro, which is not used within libpng but is available
- * for applications, is an unsigned integer of the form xyyzz corresponding
- * to the source version x.y.z (leading zeros in y and z). Beta versions
- * were given the previous public release number plus a letter, until
- * version 1.0.6j; from then on they were given the upcoming public
- * release number plus "betaNN" or "rcNN".
+ * Henceforth the source version will match the shared-library major
+ * and minor numbers; the shared-library major version number will be
+ * used for changes in backward compatibility, as it is intended. The
+ * PNG_LIBPNG_VER macro, which is not used within libpng but is available
+ * for applications, is an unsigned integer of the form xyyzz corresponding
+ * to the source version x.y.z (leading zeros in y and z). Beta versions
+ * were given the previous public release number plus a letter, until
+ * version 1.0.6j; from then on they were given the upcoming public
+ * release number plus "betaNN" or "rcNN".
*
- * Binary incompatibility exists only when applications make direct access
- * to the info_ptr or png_ptr members through png.h, and the compiled
- * application is loaded with a different version of the library.
+ * Binary incompatibility exists only when applications make direct access
+ * to the info_ptr or png_ptr members through png.h, and the compiled
+ * application is loaded with a different version of the library.
*
- * DLLNUM will change each time there are forward or backward changes
- * in binary compatibility (e.g., when a new feature is added).
+ * DLLNUM will change each time there are forward or backward changes
+ * in binary compatibility (e.g., when a new feature is added).
*
- * See libpng-manual.txt or libpng.3 for more information. The PNG
- * specification is available as a W3C Recommendation and as an ISO
- * Specification, <http://www.w3.org/TR/2003/REC-PNG-20031110/
- */
-
-/*
- * COPYRIGHT NOTICE, DISCLAIMER, and LICENSE:
- *
- * If you modify libpng you may insert additional notices immediately following
- * this sentence.
- *
- * This code is released under the libpng license.
- *
- * libpng versions 1.2.6, August 15, 2004, through 1.6.3, July 18, 2013, are
- * Copyright (c) 2004, 2006-2013 Glenn Randers-Pehrson, and are
- * distributed according to the same disclaimer and license as libpng-1.2.5
- * with the following individual added to the list of Contributing Authors:
- *
- * Cosmin Truta
- *
- * libpng versions 1.0.7, July 1, 2000, through 1.2.5, October 3, 2002, are
- * Copyright (c) 2000-2002 Glenn Randers-Pehrson, and are
- * distributed according to the same disclaimer and license as libpng-1.0.6
- * with the following individuals added to the list of Contributing Authors:
- *
- * Simon-Pierre Cadieux
- * Eric S. Raymond
- * Gilles Vollant
- *
- * and with the following additions to the disclaimer:
- *
- * There is no warranty against interference with your enjoyment of the
- * library or against infringement. There is no warranty that our
- * efforts or the library will fulfill any of your particular purposes
- * or needs. This library is provided with all faults, and the entire
- * risk of satisfactory quality, performance, accuracy, and effort is with
- * the user.
- *
- * libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are
- * Copyright (c) 1998, 1999, 2000 Glenn Randers-Pehrson, and are
- * distributed according to the same disclaimer and license as libpng-0.96,
- * with the following individuals added to the list of Contributing Authors:
- *
- * Tom Lane
- * Glenn Randers-Pehrson
- * Willem van Schaik
- *
- * libpng versions 0.89, June 1996, through 0.96, May 1997, are
- * Copyright (c) 1996, 1997 Andreas Dilger
- * Distributed according to the same disclaimer and license as libpng-0.88,
- * with the following individuals added to the list of Contributing Authors:
- *
- * John Bowler
- * Kevin Bracey
- * Sam Bushell
- * Magnus Holmgren
- * Greg Roelofs
- * Tom Tanner
- *
- * libpng versions 0.5, May 1995, through 0.88, January 1996, are
- * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
- *
- * For the purposes of this copyright and license, "Contributing Authors"
- * is defined as the following set of individuals:
- *
- * Andreas Dilger
- * Dave Martindale
- * Guy Eric Schalnat
- * Paul Schmidt
- * Tim Wegner
- *
- * The PNG Reference Library is supplied "AS IS". The Contributing Authors
- * and Group 42, Inc. disclaim all warranties, expressed or implied,
- * including, without limitation, the warranties of merchantability and of
- * fitness for any purpose. The Contributing Authors and Group 42, Inc.
- * assume no liability for direct, indirect, incidental, special, exemplary,
- * or consequential damages, which may result from the use of the PNG
- * Reference Library, even if advised of the possibility of such damage.
- *
- * Permission is hereby granted to use, copy, modify, and distribute this
- * source code, or portions hereof, for any purpose, without fee, subject
- * to the following restrictions:
- *
- * 1. The origin of this source code must not be misrepresented.
- *
- * 2. Altered versions must be plainly marked as such and must not
- * be misrepresented as being the original source.
- *
- * 3. This Copyright notice may not be removed or altered from
- * any source or altered source distribution.
- *
- * The Contributing Authors and Group 42, Inc. specifically permit, without
- * fee, and encourage the use of this source code as a component to
- * supporting the PNG file format in commercial products. If you use this
- * source code in a product, acknowledgment is not required but would be
- * appreciated.
- */
-
-/*
- * A "png_get_copyright" function is available, for convenient use in "about"
- * boxes and the like:
- *
- * printf("%s", png_get_copyright(NULL));
- *
- * Also, the PNG logo (in PNG format, of course) is supplied in the
- * files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31).
- */
-
-/*
- * Libpng is OSI Certified Open Source Software. OSI Certified is a
- * certification mark of the Open Source Initiative.
- */
-
-/*
- * The contributing authors would like to thank all those who helped
- * with testing, bug fixes, and patience. This wouldn't have been
- * possible without all of you.
- *
- * Thanks to Frank J. T. Wojcik for helping with the documentation.
+ * See libpng.txt or libpng.3 for more information. The PNG specification
+ * is available as a W3C Recommendation and as an ISO Specification,
+ * <http://www.w3.org/TR/2003/REC-PNG-20031110/
*/
/*
* Y2K compliance in libpng:
* =========================
*
- * July 18, 2013
+ * December 3, 2015
*
* Since the PNG Development group is an ad-hoc body, we can't make
* an official declaration.
*
* This is your unofficial assurance that libpng from version 0.71 and
- * upward through 1.6.3 are Y2K compliant. It is my belief that
+ * upward through 1.6.20 are Y2K compliant. It is my belief that
* earlier versions were also Y2K compliant.
*
* Libpng only has two year fields. One is a 2-byte unsigned integer
@@ -380,272 +273,18 @@
/* This is not the place to learn how to use libpng. The file libpng-manual.txt
* describes how to use libpng, and the file example.c summarizes it
* with some code on which to build. This file is useful for looking
- * at the actual function definitions and structure components.
+ * at the actual function definitions and structure components. If that
+ * file has been stripped from your copy of libpng, you can find it at
+ * <http://www.libpng.org/pub/png/libpng-manual.txt>
*
* If you just need to read a PNG file and don't want to read the documentation
* skip to the end of this file and read the section entitled 'simplified API'.
*/
-/* Sunliang.liu add 20100319 for avoid name conflict. */
-#define png_set_sig_bytes FOXIT_png_set_sig_bytes
-#define png_sig_cmp FOXIT_png_sig_cmp
-#define png_create_info_struct FOXIT_png_create_info_struct
-#define png_destroy_info_struct FOXIT_png_destroy_info_struct
-#define png_info_init_3 FOXIT_png_info_init_3
-#define png_data_freer FOXIT_png_data_freer
-#define png_free_data FOXIT_png_free_data
-#define png_info_destroy FOXIT_png_info_destroy
-#define png_get_io_ptr FOXIT_png_get_io_ptr
-#define png_init_io FOXIT_png_init_io
-#define png_convert_to_rfc1123 FOXIT_png_convert_to_rfc1123
-#define png_get_copyright FOXIT_png_get_copyright
-#define png_get_libpng_ver FOXIT_png_get_libpng_ver
-#define png_get_header_ver FOXIT_png_get_header_ver
-#define png_get_header_version FOXIT_png_get_header_version
-#define png_handle_as_unknown FOXIT_png_handle_as_unknown
-#define png_reset_zstream FOXIT_png_reset_zstream
-#define png_access_version_number FOXIT_png_access_version_number
-#define png_mmx_support FOXIT_png_mmx_support
-#define png_create_read_struct FOXIT_png_create_read_struct
-#define png_create_read_struct_2 FOXIT_png_create_read_struct_2
-#define png_create_write_struct FOXIT_png_create_write_struct
-#define png_create_write_struct_2 FOXIT_png_create_write_struct_2
-#define png_get_compression_buffer_size FOXIT_png_get_compression_buffer_size
-#define png_set_compression_buffer_size FOXIT_png_set_compression_buffer_size
-#define png_set_longjmp_fn FOXIT_png_set_longjmp_fn
-#define png_longjmp FOXIT_png_longjmp
-#define png_write_sig FOXIT_png_write_sig
-#define png_write_chunk FOXIT_png_write_chunk
-#define png_write_chunk_start FOXIT_png_write_chunk_start
-#define png_write_chunk_data FOXIT_png_write_chunk_data
-#define png_write_chunk_end FOXIT_png_write_chunk_end
-#define png_write_info_before_PLTE FOXIT_png_write_info_before_PLTE
-#define png_write_info FOXIT_png_write_info
-#define png_read_info FOXIT_png_read_info
-#define png_convert_to_rfc1123_buffer FOXIT_png_convert_to_rfc1123_buffer
-#define png_convert_from_struct_tm FOXIT_png_convert_from_struct_tm
-#define png_convert_from_time_t FOXIT_png_convert_from_time_t
-#define png_set_expand FOXIT_png_set_expand
-#define png_set_expand_gray_1_2_4_to_8 FOXIT_png_set_expand_gray_1_2_4_to_8
-#define png_set_palette_to_rgb FOXIT_png_set_palette_to_rgb
-#define png_set_tRNS_to_alpha FOXIT_png_set_tRNS_to_alpha
-#define png_set_expand_16 FOXIT_png_set_expand_16
-#define png_set_bgr FOXIT_png_set_bgr
-#define png_set_gray_to_rgb FOXIT_png_set_gray_to_rgb
-#define png_set_rgb_to_gray FOXIT_png_set_rgb_to_gray
-#define png_set_rgb_to_gray_fixed FOXIT_png_set_rgb_to_gray_fixed
-#define png_get_rgb_to_gray_status FOXIT_png_get_rgb_to_gray_status
-#define png_build_grayscale_palette FOXIT_png_build_grayscale_palette
-#define png_set_alpha_mode FOXIT_png_set_alpha_mode
-#define png_set_alpha_mode_fixed FOXIT_png_set_alpha_mode_fixed
-#define png_set_strip_alpha FOXIT_png_set_strip_alpha
-#define png_set_swap_alpha FOXIT_png_set_swap_alpha
-#define png_set_invert_alpha FOXIT_png_set_invert_alpha
-#define png_set_filler FOXIT_png_set_filler
-#define png_set_add_alpha FOXIT_png_set_add_alpha
-#define png_set_swap FOXIT_png_set_swap
-#define png_set_packing FOXIT_png_set_packing
-#define png_set_packswap FOXIT_png_set_packswap
-#define png_set_shift FOXIT_png_set_shift
-#define png_set_interlace_handling FOXIT_png_set_interlace_handling
-#define png_set_invert_mono FOXIT_png_set_invert_mono
-#define png_set_background FOXIT_png_set_background
-#define png_set_background_fixed FOXIT_png_set_background_fixed
-#define png_set_scale_16 FOXIT_png_set_scale_16
-#define png_set_quantize FOXIT_png_set_quantize
-#define png_set_gamma FOXIT_png_set_gamma
-#define png_set_gamma_fixed FOXIT_png_set_gamma_fixed
-#define png_set_flush FOXIT_png_set_flush
-#define png_write_flush FOXIT_png_write_flush
-#define png_start_read_image FOXIT_png_start_read_image
-#define png_read_update_info FOXIT_png_read_update_info
-#define png_read_rows FOXIT_png_read_rows
-#define png_read_row FOXIT_png_read_row
-#define png_read_image FOXIT_png_read_image
-#define png_write_row FOXIT_png_write_row
-#define png_write_rows FOXIT_png_write_rows
-#define png_write_image FOXIT_png_write_image
-#define png_write_end FOXIT_png_write_end
-#define png_read_end FOXIT_png_read_end
-#define png_destroy_read_struct FOXIT_png_destroy_read_struct
-#define png_destroy_write_struct FOXIT_png_destroy_write_struct
-#define png_set_crc_action FOXIT_png_set_crc_action
-#define png_set_filter FOXIT_png_set_filter
-#define png_set_filter_heuristics FOXIT_png_set_filter_heuristics
-#define png_set_filter_heuristics_fixed FOXIT_png_set_filter_heuristics_fixed
-#define png_set_compression_level FOXIT_png_set_compression_level
-#define png_set_compression_mem_level FOXIT_png_set_compression_mem_level
-#define png_set_compression_strategy FOXIT_png_set_compression_strategy
-#define png_set_compression_window_bits FOXIT_png_set_compression_window_bits
-#define png_set_compression_method FOXIT_png_set_compression_method
-#define png_set_text_compression_level FOXIT_png_set_text_compression_level
-#define png_set_text_compression_mem_level FOXIT_png_set_text_compression_mem_level
-#define png_set_text_compression_strategy FOXIT_png_set_text_compression_strategy
-#define png_set_text_compression_window_bits FOXIT_png_set_text_compression_window_bits
-#define png_set_text_compression_method FOXIT_png_set_text_compression_method
-#define png_set_error_fn FOXIT_png_set_error_fn
-#define png_get_error_ptr FOXIT_png_get_error_ptr
-#define png_set_write_fn FOXIT_png_set_write_fn
-#define png_set_read_fn FOXIT_png_set_read_fn
-#define png_set_read_status_fn FOXIT_png_set_read_status_fn
-#define png_set_write_status_fn FOXIT_png_set_write_status_fn
-#define png_set_read_user_transform_fn FOXIT_png_set_read_user_transform_fn
-#define png_set_write_user_transform_fn FOXIT_png_set_write_user_transform_fn
-#define png_set_user_transform_info FOXIT_png_set_user_transform_info
-#define png_get_user_transform_ptr FOXIT_png_get_user_transform_ptr
-#define png_get_current_row_number FOXIT_png_get_current_row_number
-#define png_get_current_pass_number FOXIT_png_get_current_pass_number
-#define png_set_read_user_chunk_fn FOXIT_png_set_read_user_chunk_fn
-#define png_get_user_chunk_ptr FOXIT_png_get_user_chunk_ptr
-#define png_set_progressive_read_fn FOXIT_png_set_progressive_read_fn
-#define png_get_progressive_ptr FOXIT_png_get_progressive_ptr
-#define png_process_data FOXIT_png_process_data
-#define png_process_data_pause FOXIT_png_process_data_pause
-#define png_process_data_skip FOXIT_png_process_data_skip
-#define png_progressive_combine_row FOXIT_png_progressive_combine_row
-#define png_calloc FOXIT_png_calloc
-#define png_error FOXIT_png_error
-#define png_chunk_error FOXIT_png_chunk_error
-#define png_err FOXIT_png_err
-#define png_warning FOXIT_png_warning
-#define png_chunk_warning FOXIT_png_chunk_warning
-#define png_benign_error FOXIT_png_benign_error
-#define png_chunk_benign_error FOXIT_png_chunk_benign_error
-#define png_set_benign_errors FOXIT_png_set_benign_errors
-#define png_get_valid FOXIT_png_get_valid
-#define png_get_rowbytes FOXIT_png_get_rowbytes
-#define png_get_rows FOXIT_png_get_rows
-#define png_set_rows FOXIT_png_set_rows
-#define png_get_channels FOXIT_png_get_channels
-#define png_get_image_width FOXIT_png_get_image_width
-#define png_get_image_height FOXIT_png_get_image_height
-#define png_get_bit_depth FOXIT_png_get_bit_depth
-#define png_get_color_type FOXIT_png_get_color_type
-#define png_get_filter_type FOXIT_png_get_filter_type
-#define png_get_interlace_type FOXIT_png_get_interlace_type
-#define png_get_compression_type FOXIT_png_get_compression_type
-#define png_get_pixels_per_meter FOXIT_png_get_pixels_per_meter
-#define png_get_x_pixels_per_meter FOXIT_png_get_x_pixels_per_meter
-#define png_get_y_pixels_per_meter FOXIT_png_get_y_pixels_per_meter
-#define png_get_pixel_aspect_ratio FOXIT_png_get_pixel_aspect_ratio
-#define png_get_pixel_aspect_ratio_fixed FOXIT_png_get_pixel_aspect_ratio_fixed
-#define png_get_x_offset_pixels FOXIT_png_get_x_offset_pixels
-#define png_get_y_offset_pixels FOXIT_png_get_y_offset_pixels
-#define png_get_x_offset_microns FOXIT_png_get_x_offset_microns
-#define png_get_y_offset_microns FOXIT_png_get_y_offset_microns
-#define png_get_signature FOXIT_png_get_signature
-#define png_get_bKGD FOXIT_png_get_bKGD
-#define png_set_bKGD FOXIT_png_set_bKGD
-#define png_get_cHRM FOXIT_png_get_cHRM
-#define png_get_cHRM_XYZ FOXIT_png_get_cHRM_XYZ
-#define png_get_cHRM_fixed FOXIT_png_get_cHRM_fixed
-#define png_get_cHRM_XYZ_fixed FOXIT_png_get_cHRM_XYZ_fixed
-#define png_set_cHRM FOXIT_png_set_cHRM
-#define png_set_cHRM_XYZ FOXIT_png_set_cHRM_XYZ
-#define png_set_cHRM_fixed FOXIT_png_set_cHRM_fixed
-#define png_set_cHRM_XYZ_fixed FOXIT_png_set_cHRM_XYZ_fixed
-#define png_get_gAMA FOXIT_png_get_gAMA
-#define png_set_gAMA FOXIT_png_set_gAMA
-#define png_set_gAMA_fixed FOXIT_png_set_gAMA_fixed
-#define png_get_hIST FOXIT_png_get_hIST
-#define png_set_hIST FOXIT_png_set_hIST
-#define png_get_IHDR FOXIT_png_get_IHDR
-#define png_set_IHDR FOXIT_png_set_IHDR
-#define png_get_oFFs FOXIT_png_get_oFFs
-#define png_set_oFFs FOXIT_png_set_oFFs
-#define png_get_pCAL FOXIT_png_get_pCAL
-#define png_set_pCAL FOXIT_png_set_pCAL
-#define png_set_pHYs FOXIT_png_set_pHYs
-#define png_get_PLTE FOXIT_png_get_PLTE
-#define png_set_PLTE FOXIT_png_set_PLTE
-#define png_get_sBIT FOXIT_png_get_sBIT
-#define png_set_sBIT FOXIT_png_set_sBIT
-#define png_get_sRGB FOXIT_png_get_sRGB
-#define png_set_sRGB FOXIT_png_set_sRGB
-#define png_set_sRGB_gAMA_and_cHRM FOXIT_png_set_sRGB_gAMA_and_cHRM
-#define png_get_iCCP FOXIT_png_get_iCCP
-#define png_set_iCCP FOXIT_png_set_iCCP
-#define png_get_sPLT FOXIT_png_get_sPLT
-#define png_set_sPLT FOXIT_png_set_sPLT
-#define png_get_text FOXIT_png_get_text
-#define png_set_text FOXIT_png_set_text
-#define png_get_tIME FOXIT_png_get_tIME
-#define png_set_tIME FOXIT_png_set_tIME
-#define png_get_tRNS FOXIT_png_get_tRNS
-#define png_set_tRNS FOXIT_png_set_tRNS
-#define png_get_sCAL FOXIT_png_get_sCAL
-#define png_get_sCAL_fixed FOXIT_png_get_sCAL_fixed
-#define png_get_sCAL_s FOXIT_png_get_sCAL_s
-#define png_set_sCAL FOXIT_png_set_sCAL
-#define png_set_sCAL_s FOXIT_png_set_sCAL_s
-#define png_set_keep_unknown_chunks FOXIT_png_set_keep_unknown_chunks
-#define png_set_unknown_chunks FOXIT_png_set_unknown_chunks
-#define png_set_unknown_chunk_location FOXIT_png_set_unknown_chunk_location
-#define png_get_unknown_chunks FOXIT_png_get_unknown_chunks
-#define png_set_invalid FOXIT_png_set_invalid
-#define png_read_png FOXIT_png_read_png
-#define png_write_png FOXIT_png_write_png
-#define png_permit_mng_features FOXIT_png_permit_mng_features
-#define png_set_strip_error_numbers FOXIT_png_set_strip_error_numbers
-#define png_set_user_limits FOXIT_png_set_user_limits
-#define png_get_user_width_max FOXIT_png_get_user_width_max
-#define png_get_user_height_max FOXIT_png_get_user_height_max
-#define png_set_chunk_cache_max FOXIT_png_set_chunk_cache_max
-#define png_get_chunk_cache_max FOXIT_png_get_chunk_cache_max
-#define png_set_chunk_malloc_max FOXIT_png_set_chunk_malloc_max
-#define png_get_chunk_malloc_max FOXIT_png_get_chunk_malloc_max
-#define png_get_pixels_per_inch FOXIT_png_get_pixels_per_inch
-#define png_get_x_pixels_per_inch FOXIT_png_get_x_pixels_per_inch
-#define png_get_y_pixels_per_inch FOXIT_png_get_y_pixels_per_inch
-#define png_get_x_offset_inches FOXIT_png_get_x_offset_inches
-#define png_get_x_offset_inches_fixed FOXIT_png_get_x_offset_inches_fixed
-#define png_get_y_offset_inches FOXIT_png_get_y_offset_inches
-#define png_get_y_offset_inches_fixed FOXIT_png_get_y_offset_inches_fixed
-#define png_get_pHYs_dpi FOXIT_png_get_pHYs_dpi
-#define png_get_io_state FOXIT_png_get_io_state
-#define png_get_io_chunk_name FOXIT_png_get_io_chunk_name
-#define png_get_io_chunk_type FOXIT_png_get_io_chunk_type
-#define png_get_uint_31 FOXIT_png_get_uint_31
-#define png_get_uint_32 FOXIT_png_get_uint_32
-#define png_get_uint_16 FOXIT_png_get_uint_16
-#define png_get_int_32 FOXIT_png_get_int_32
-#define png_save_uint_32 FOXIT_png_save_uint_32
-#define png_save_int_32 FOXIT_png_save_int_32
-#define png_save_uint_16 FOXIT_png_save_uint_16
-#define png_image_begin_read_from_file FOXIT_png_image_begin_read_from_file
-#define png_image_begin_read_from_stdio FOXIT_png_image_begin_read_from_stdio
-#define png_image_begin_read_from_memory FOXIT_png_image_begin_read_from_memory
-#define png_image_finish_read FOXIT_png_image_finish_read
-#define png_image_free FOXIT_png_image_free
-#define png_image_write_to_file FOXIT_png_image_write_to_file
-#define png_image_write_to_stdio FOXIT_png_image_write_to_stdio
-#define png_set_check_for_invalid_index FOXIT_png_set_check_for_invalid_index
-#define png_get_palette_max FOXIT_png_get_palette_max
-#define png_set_option FOXIT_png_set_option
-
-#define png_set_strip_16 FOXIT_png_set_strip_16
-#define png_64bit_product FOXIT_png_64bit_product
-#define png_check_cHRM_fixed FOXIT_png_check_cHRM_fixed
-#define png_free FOXIT_png_free
-#define png_free_default FOXIT_png_free_default
-#define png_get_mem_ptr FOXIT_png_get_mem_ptr
-#define png_malloc FOXIT_png_malloc
-#define png_malloc_default FOXIT_png_malloc_default
-#define png_malloc_warn FOXIT_png_malloc_warn
-#define png_memcpy_check FOXIT_png_memcpy_check
-#define png_memset_check FOXIT_png_memset_check
-#define png_pass_dsp_mask FOXIT_png_pass_dsp_mask
-#define png_pass_inc FOXIT_png_pass_inc
-#define png_pass_mask FOXIT_png_pass_mask
-#define png_pass_start FOXIT_png_pass_start
-#define png_pass_yinc FOXIT_png_pass_yinc
-#define png_pass_ystart FOXIT_png_pass_ystart
-#define png_set_mem_fn FOXIT_png_set_mem_fn
-
/* Version information for png.h - this should match the version in png.c */
-#define PNG_LIBPNG_VER_STRING "1.6.3"
+#define PNG_LIBPNG_VER_STRING "1.6.20"
#define PNG_HEADER_VERSION_STRING \
- " libpng version 1.6.3 - July 18, 2013\n"
+ " libpng version 1.6.20 - December 3, 2015\n"
#define PNG_LIBPNG_VER_SONUM 16
#define PNG_LIBPNG_VER_DLLNUM 16
@@ -653,7 +292,7 @@
/* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */
#define PNG_LIBPNG_VER_MAJOR 1
#define PNG_LIBPNG_VER_MINOR 6
-#define PNG_LIBPNG_VER_RELEASE 3
+#define PNG_LIBPNG_VER_RELEASE 20
/* This should match the numeric part of the final component of
* PNG_LIBPNG_VER_STRING, omitting any leading zero:
@@ -684,7 +323,7 @@
* version 1.0.0 was mis-numbered 100 instead of 10000). From
* version 1.0.1 it's xxyyzz, where x=major, y=minor, z=release
*/
-#define PNG_LIBPNG_VER 10603 /* 1.6.3 */
+#define PNG_LIBPNG_VER 10620 /* 1.6.20 */
/* Library configuration: these options cannot be changed after
* the library has been built.
@@ -741,17 +380,22 @@
/* This file is arranged in several sections:
*
- * 1. Any configuration options that can be specified by for the application
+ * 1. [omitted]
+ * 2. Any configuration options that can be specified by for the application
* code when it is built. (Build time configuration is in pnglibconf.h)
- * 2. Type definitions (base types are defined in pngconf.h), structure
+ * 3. Type definitions (base types are defined in pngconf.h), structure
* definitions.
- * 3. Exported library functions.
- * 4. Simplified API.
+ * 4. Exported library functions.
+ * 5. Simplified API.
+ * 6. Implementation options.
*
* The library source code has additional files (principally pngpriv.h) that
* allow configuration of the library.
*/
-/* Section 1: run time configuration
+
+/* Section 1: [omitted] */
+
+/* Section 2: run time configuration
* See pnglibconf.h for build time configuration
*
* Run time configuration allows the application to choose between
@@ -781,7 +425,7 @@
* Otherwise the calls are mapped to png_error.
*/
-/* Section 2: type definitions, including structures and compile time
+/* Section 3: type definitions, including structures and compile time
* constants.
* See pngconf.h for base types that vary by machine/system
*/
@@ -789,7 +433,7 @@
/* This triggers a compiler error in png.c, if png.c and png.h
* do not agree upon the version number.
*/
-typedef char* png_libpng_version_1_6_3;
+typedef char* png_libpng_version_1_6_20;
/* Basic control structions. Read libpng-manual.txt or libpng.3 for more info.
*
@@ -971,7 +615,8 @@
typedef const png_time * png_const_timep;
typedef png_time * * png_timepp;
-#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
+#if defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED) ||\
+ defined(PNG_USER_CHUNKS_SUPPORTED)
/* png_unknown_chunk is a structure to hold queued chunks for which there is
* no specific support. The idea is that we can use this to queue
* up private chunks for output even though the library doesn't actually
@@ -1104,7 +749,9 @@
#define PNG_INFO_iCCP 0x1000 /* ESR, 1.0.6 */
#define PNG_INFO_sPLT 0x2000 /* ESR, 1.0.6 */
#define PNG_INFO_sCAL 0x4000 /* ESR, 1.0.6 */
+#if INT_MAX >= 0x8000 /* else this might break */
#define PNG_INFO_IDAT 0x8000 /* ESR, 1.0.6 */
+#endif
/* This is used for the transformation routines, as some of them
* change these values for the row. It also should enable using
@@ -1208,7 +855,9 @@
#define PNG_TRANSFORM_GRAY_TO_RGB 0x2000 /* read only */
/* Added to libpng-1.5.4 */
#define PNG_TRANSFORM_EXPAND_16 0x4000 /* read only */
+#if INT_MAX >= 0x8000 /* else this might break */
#define PNG_TRANSFORM_SCALE_16 0x8000 /* read only */
+#endif
/* Flags for MNG supported features */
#define PNG_FLAG_MNG_EMPTY_PLTE 0x01
@@ -1225,7 +874,7 @@
png_alloc_size_t));
typedef PNG_CALLBACK(void, *png_free_ptr, (png_structp, png_voidp));
-/* Section 3: exported functions
+/* Section 4: exported functions
* Here are the function definitions most commonly used. This is not
* the place to find out how to use libpng. See libpng-manual.txt for the
* full explanation, see example.c for the summary. This just provides
@@ -1401,7 +1050,7 @@
/* Convert from time_t to png_time. Uses gmtime() */
PNG_EXPORT(25, void, png_convert_from_time_t, (png_timep ptime, time_t ttime));
-#endif /* PNG_CONVERT_tIME_SUPPORTED */
+#endif /* CONVERT_tIME */
#ifdef PNG_READ_EXPAND_SUPPORTED
/* Expand data to 24-bit RGB, or 8-bit grayscale, with alpha if available. */
@@ -1450,9 +1099,9 @@
#endif
#ifdef PNG_READ_ALPHA_MODE_SUPPORTED
-/* How the alpha channel is interpreted - this affects how the color channels of
- * a PNG file are returned when an alpha channel, or tRNS chunk in a palette
- * file, is present.
+/* How the alpha channel is interpreted - this affects how the color channels
+ * of a PNG file are returned to the calling application when an alpha channel,
+ * or a tRNS chunk in a palette file, is present.
*
* This has no effect on the way pixels are written into a PNG output
* datastream. The color samples in a PNG datastream are never premultiplied
@@ -1460,33 +1109,19 @@
*
* The default is to return data according to the PNG specification: the alpha
* channel is a linear measure of the contribution of the pixel to the
- * corresponding composited pixel. The gamma encoded color channels must be
- * scaled according to the contribution and to do this it is necessary to undo
+ * corresponding composited pixel, and the color channels are unassociated
+ * (not premultiplied). The gamma encoded color channels must be scaled
+ * according to the contribution and to do this it is necessary to undo
* the encoding, scale the color values, perform the composition and reencode
* the values. This is the 'PNG' mode.
*
* The alternative is to 'associate' the alpha with the color information by
- * storing color channel values that have been scaled by the alpha. The
- * advantage is that the color channels can be resampled (the image can be
- * scaled) in this form. The disadvantage is that normal practice is to store
- * linear, not (gamma) encoded, values and this requires 16-bit channels for
- * still images rather than the 8-bit channels that are just about sufficient if
- * gamma encoding is used. In addition all non-transparent pixel values,
- * including completely opaque ones, must be gamma encoded to produce the final
- * image. This is the 'STANDARD', 'ASSOCIATED' or 'PREMULTIPLIED' mode (the
- * latter being the two common names for associated alpha color channels.)
+ * storing color channel values that have been scaled by the alpha.
+ * image. These are the 'STANDARD', 'ASSOCIATED' or 'PREMULTIPLIED' modes
+ * (the latter being the two common names for associated alpha color channels).
*
- * Since it is not necessary to perform arithmetic on opaque color values so
- * long as they are not to be resampled and are in the final color space it is
- * possible to optimize the handling of alpha by storing the opaque pixels in
- * the PNG format (adjusted for the output color space) while storing partially
- * opaque pixels in the standard, linear, format. The accuracy required for
- * standard alpha composition is relatively low, because the pixels are
- * isolated, therefore typically the accuracy loss in storing 8-bit linear
- * values is acceptable. (This is not true if the alpha channel is used to
- * simulate transparency over large areas - use 16 bits or the PNG mode in
- * this case!) This is the 'OPTIMIZED' mode. For this mode a pixel is
- * treated as opaque only if the alpha value is equal to the maximum value.
+ * For the 'OPTIMIZED' mode, a pixel is treated as opaque only if the alpha
+ * value is equal to the maximum value.
*
* The final choice is to gamma encode the alpha channel as well. This is
* broken because, in practice, no implementation that uses this choice
@@ -1513,68 +1148,7 @@
#if defined(PNG_GAMMA_SUPPORTED) || defined(PNG_READ_ALPHA_MODE_SUPPORTED)
/* The output_gamma value is a screen gamma in libpng terminology: it expresses
- * how to decode the output values, not how they are encoded. The values used
- * correspond to the normal numbers used to describe the overall gamma of a
- * computer display system; for example 2.2 for an sRGB conformant system. The
- * values are scaled by 100000 in the _fixed version of the API (so 220000 for
- * sRGB.)
- *
- * The inverse of the value is always used to provide a default for the PNG file
- * encoding if it has no gAMA chunk and if png_set_gamma() has not been called
- * to override the PNG gamma information.
- *
- * When the ALPHA_OPTIMIZED mode is selected the output gamma is used to encode
- * opaque pixels however pixels with lower alpha values are not encoded,
- * regardless of the output gamma setting.
- *
- * When the standard Porter Duff handling is requested with mode 1 the output
- * encoding is set to be linear and the output_gamma value is only relevant
- * as a default for input data that has no gamma information. The linear output
- * encoding will be overridden if png_set_gamma() is called - the results may be
- * highly unexpected!
- *
- * The following numbers are derived from the sRGB standard and the research
- * behind it. sRGB is defined to be approximated by a PNG gAMA chunk value of
- * 0.45455 (1/2.2) for PNG. The value implicitly includes any viewing
- * correction required to take account of any differences in the color
- * environment of the original scene and the intended display environment; the
- * value expresses how to *decode* the image for display, not how the original
- * data was *encoded*.
- *
- * sRGB provides a peg for the PNG standard by defining a viewing environment.
- * sRGB itself, and earlier TV standards, actually use a more complex transform
- * (a linear portion then a gamma 2.4 power law) than PNG can express. (PNG is
- * limited to simple power laws.) By saying that an image for direct display on
- * an sRGB conformant system should be stored with a gAMA chunk value of 45455
- * (11.3.3.2 and 11.3.3.5 of the ISO PNG specification) the PNG specification
- * makes it possible to derive values for other display systems and
- * environments.
- *
- * The Mac value is deduced from the sRGB based on an assumption that the actual
- * extra viewing correction used in early Mac display systems was implemented as
- * a power 1.45 lookup table.
- *
- * Any system where a programmable lookup table is used or where the behavior of
- * the final display device characteristics can be changed requires system
- * specific code to obtain the current characteristic. However this can be
- * difficult and most PNG gamma correction only requires an approximate value.
- *
- * By default, if png_set_alpha_mode() is not called, libpng assumes that all
- * values are unencoded, linear, values and that the output device also has a
- * linear characteristic. This is only very rarely correct - it is invariably
- * better to call png_set_alpha_mode() with PNG_DEFAULT_sRGB than rely on the
- * default if you don't know what the right answer is!
- *
- * The special value PNG_GAMMA_MAC_18 indicates an older Mac system (pre Mac OS
- * 10.6) which used a correction table to implement a somewhat lower gamma on an
- * otherwise sRGB system.
- *
- * Both these values are reserved (not simple gamma values) in order to allow
- * more precise correction internally in the future.
- *
- * NOTE: the following values can be passed to either the fixed or floating
- * point APIs, but the floating point API will also accept floating point
- * values.
+ * how to decode the output values, not how they are encoded.
*/
#define PNG_DEFAULT_sRGB -1 /* sRGB gamma and color space */
#define PNG_GAMMA_MAC_18 -2 /* Old Mac '1.8' gamma and color space */
@@ -1673,16 +1247,16 @@
#endif
#if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
-/* Add a filler byte to 8-bit Gray or 24-bit RGB images. */
+/* Add a filler byte to 8-bit or 16-bit Gray or 24-bit or 48-bit RGB images. */
PNG_EXPORT(39, void, png_set_filler, (png_structrp png_ptr, png_uint_32 filler,
int flags));
/* The values of the PNG_FILLER_ defines should NOT be changed */
# define PNG_FILLER_BEFORE 0
# define PNG_FILLER_AFTER 1
-/* Add an alpha byte to 8-bit Gray or 24-bit RGB images. */
+/* Add an alpha byte to 8-bit or 16-bit Gray or 24-bit or 48-bit RGB images. */
PNG_EXPORT(40, void, png_set_add_alpha, (png_structrp png_ptr,
png_uint_32 filler, int flags));
-#endif /* PNG_READ_FILLER_SUPPORTED || PNG_WRITE_FILLER_SUPPORTED */
+#endif /* READ_FILLER || WRITE_FILLER */
#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
/* Swap bytes in 16-bit depth files. */
@@ -1872,6 +1446,7 @@
#define PNG_CRC_QUIET_USE 4 /* quiet/use data quiet/use data */
#define PNG_CRC_NO_CHANGE 5 /* use current value use current value */
+#ifdef PNG_WRITE_SUPPORTED
/* These functions give the user control over the scan-line filtering in
* libpng and the compression methods used by zlib. These functions are
* mainly useful for testing, as the defaults should work with most users.
@@ -1885,6 +1460,7 @@
*/
PNG_EXPORT(67, void, png_set_filter, (png_structrp png_ptr, int method,
int filters));
+#endif /* WRITE */
/* Flags for png_set_filter() to say which filters to use. The flags
* are chosen so that they don't conflict with real filter types
@@ -1910,35 +1486,8 @@
#define PNG_FILTER_VALUE_PAETH 4
#define PNG_FILTER_VALUE_LAST 5
-#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* EXPERIMENTAL */
-/* The "heuristic_method" is given by one of the PNG_FILTER_HEURISTIC_
- * defines, either the default (minimum-sum-of-absolute-differences), or
- * the experimental method (weighted-minimum-sum-of-absolute-differences).
- *
- * Weights are factors >= 1.0, indicating how important it is to keep the
- * filter type consistent between rows. Larger numbers mean the current
- * filter is that many times as likely to be the same as the "num_weights"
- * previous filters. This is cumulative for each previous row with a weight.
- * There needs to be "num_weights" values in "filter_weights", or it can be
- * NULL if the weights aren't being specified. Weights have no influence on
- * the selection of the first row filter. Well chosen weights can (in theory)
- * improve the compression for a given image.
- *
- * Costs are factors >= 1.0 indicating the relative decoding costs of a
- * filter type. Higher costs indicate more decoding expense, and are
- * therefore less likely to be selected over a filter with lower computational
- * costs. There needs to be a value in "filter_costs" for each valid filter
- * type (given by PNG_FILTER_VALUE_LAST), or it can be NULL if you aren't
- * setting the costs. Costs try to improve the speed of decompression without
- * unduly increasing the compressed image size.
- *
- * A negative weight or cost indicates the default value is to be used, and
- * values in the range [0.0, 1.0) indicate the value is to remain unchanged.
- * The default values for both weights and costs are currently 1.0, but may
- * change if good general weighting/cost heuristics can be found. If both
- * the weights and costs are set to 1.0, this degenerates the WEIGHTED method
- * to the UNWEIGHTED method, but with added encoding time/computation.
- */
+#ifdef PNG_WRITE_SUPPORTED
+#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* DEPRECATED */
PNG_FP_EXPORT(68, void, png_set_filter_heuristics, (png_structrp png_ptr,
int heuristic_method, int num_weights, png_const_doublep filter_weights,
png_const_doublep filter_costs))
@@ -1946,17 +1495,14 @@
(png_structrp png_ptr, int heuristic_method, int num_weights,
png_const_fixed_point_p filter_weights,
png_const_fixed_point_p filter_costs))
-#endif /* PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */
+#endif /* WRITE_WEIGHTED_FILTER */
-/* Heuristic used for row filter selection. These defines should NOT be
- * changed.
- */
+/* The following are no longer used and will be removed from libpng-1.7: */
#define PNG_FILTER_HEURISTIC_DEFAULT 0 /* Currently "UNWEIGHTED" */
#define PNG_FILTER_HEURISTIC_UNWEIGHTED 1 /* Used by libpng < 0.95 */
#define PNG_FILTER_HEURISTIC_WEIGHTED 2 /* Experimental feature */
#define PNG_FILTER_HEURISTIC_LAST 3 /* Not a valid value */
-#ifdef PNG_WRITE_SUPPORTED
/* Set the library compression level. Currently, valid values range from
* 0 - 9, corresponding directly to the zlib compression levels 0 - 9
* (0 - no compression, 9 - "maximal" compression). Note that tests have
@@ -1964,6 +1510,7 @@
* for PNG images, and do considerably fewer caclulations. In the future,
* these values may not correspond directly to the zlib compression levels.
*/
+#ifdef PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED
PNG_EXPORT(69, void, png_set_compression_level, (png_structrp png_ptr,
int level));
@@ -1981,7 +1528,7 @@
PNG_EXPORT(73, void, png_set_compression_method, (png_structrp png_ptr,
int method));
-#endif
+#endif /* WRITE_CUSTOMIZE_COMPRESSION */
#ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
/* Also set zlib parameters for compressing non-IDAT chunks */
@@ -2002,7 +1549,8 @@
PNG_EXPORT(226, void, png_set_text_compression_method, (png_structrp png_ptr,
int method));
-#endif /* PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED */
+#endif /* WRITE_CUSTOMIZE_ZTXT_COMPRESSION */
+#endif /* WRITE */
/* These next functions are called for input/output, memory, and error
* handling. They are in the file pngrio.c, pngwio.c, and pngerror.c,
@@ -2113,7 +1661,7 @@
*
* The integer return from the callback function is interpreted thus:
*
- * negative: An error occured, png_chunk_error will be called.
+ * negative: An error occurred; png_chunk_error will be called.
* zero: The chunk was not handled, the chunk will be saved. A critical
* chunk will cause an error at this point unless it is to be saved.
* positive: The chunk was handled, libpng will ignore/discard it.
@@ -2162,7 +1710,6 @@
*/
PNG_EXPORT(220, png_uint_32, png_process_data_skip, (png_structrp));
-#ifdef PNG_READ_INTERLACING_SUPPORTED
/* Function that combines rows. 'new_row' is a flag that should come from
* the callback and be non-NULL if anything needs to be done; the library
* stores its own version of the new data internally and ignores the passed
@@ -2170,8 +1717,7 @@
*/
PNG_EXPORT(93, void, png_progressive_combine_row, (png_const_structrp png_ptr,
png_bytep old_row, png_const_bytep new_row));
-#endif /* PNG_READ_INTERLACING_SUPPORTED */
-#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
+#endif /* PROGRESSIVE_READ */
PNG_EXPORTA(94, png_voidp, png_malloc, (png_const_structrp png_ptr,
png_alloc_size_t size), PNG_ALLOCATED);
@@ -2197,8 +1743,8 @@
* It is unlikely that this function works correctly as of 1.6.0 and using it
* may result either in memory leaks or double free of allocated data.
*/
-PNG_EXPORTA(99, void, png_data_freer, (png_const_structrp png_ptr,
- png_inforp info_ptr, int freer, png_uint_32 mask), PNG_DEPRECATED);
+PNG_EXPORT(99, void, png_data_freer, (png_const_structrp png_ptr,
+ png_inforp info_ptr, int freer, png_uint_32 mask));
/* Assignments for png_data_freer */
#define PNG_DESTROY_WILL_FREE_DATA 1
@@ -2240,6 +1786,8 @@
#else
/* Fatal error in PNG image of libpng - can't continue */
PNG_EXPORTA(104, void, png_err, (png_const_structrp png_ptr), PNG_NORETURN);
+# define png_error(s1,s2) png_err(s1)
+# define png_chunk_error(s1,s2) png_err(s1)
#endif
#ifdef PNG_WARNINGS_SUPPORTED
@@ -2250,6 +1798,9 @@
/* Non-fatal error in libpng, chunk name is prepended to message. */
PNG_EXPORT(106, void, png_chunk_warning, (png_const_structrp png_ptr,
png_const_charp warning_message));
+#else
+# define png_warning(s1,s2) ((void)(s1))
+# define png_chunk_warning(s1,s2) ((void)(s1))
#endif
#ifdef PNG_BENIGN_ERRORS_SUPPORTED
@@ -2367,7 +1918,7 @@
PNG_EXPORT(129, png_int_32, png_get_y_offset_microns,
(png_const_structrp png_ptr, png_const_inforp info_ptr));
-#endif /* PNG_EASY_ACCESS_SUPPORTED */
+#endif /* EASY_ACCESS */
#ifdef PNG_READ_SUPPORTED
/* Returns pointer to signature string read from PNG header */
@@ -2619,7 +2170,7 @@
PNG_EXPORT(171, void, png_set_sCAL_s, (png_const_structrp png_ptr,
png_inforp info_ptr, int unit,
png_const_charp swidth, png_const_charp sheight));
-#endif /* PNG_sCAL_SUPPORTED */
+#endif /* sCAL */
#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
/* Provide the default handling for all unknown chunks or, optionally, for
@@ -2760,11 +2311,15 @@
#ifdef PNG_INFO_IMAGE_SUPPORTED
/* The "params" pointer is currently not used and is for future expansion. */
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
PNG_EXPORT(178, void, png_read_png, (png_structrp png_ptr, png_inforp info_ptr,
int transforms, png_voidp params));
+#endif
+#ifdef PNG_WRITE_SUPPORTED
PNG_EXPORT(179, void, png_write_png, (png_structrp png_ptr, png_inforp info_ptr,
int transforms, png_voidp params));
#endif
+#endif
PNG_EXPORT(180, png_const_charp, png_get_copyright,
(png_const_structrp png_ptr));
@@ -2843,8 +2398,8 @@
PNG_EXPORT(198, png_uint_32, png_get_pHYs_dpi, (png_const_structrp png_ptr,
png_const_inforp info_ptr, png_uint_32 *res_x, png_uint_32 *res_y,
int *unit_type));
-# endif /* PNG_pHYs_SUPPORTED */
-#endif /* PNG_INCH_CONVERSIONS_SUPPORTED */
+# endif /* pHYs */
+#endif /* INCH_CONVERSIONS */
/* Added in libpng-1.4.0 */
#ifdef PNG_IO_STATE_SUPPORTED
@@ -2867,7 +2422,7 @@
# define PNG_IO_CHUNK_CRC 0x0080 /* currently at the chunk crc */
# define PNG_IO_MASK_OP 0x000f /* current operation: reading/writing */
# define PNG_IO_MASK_LOC 0x00f0 /* current location: sig/hdr/data/crc */
-#endif /* ?PNG_IO_STATE_SUPPORTED */
+#endif /* IO_STATE */
/* Interlace support. The following macros are always defined so that if
* libpng interlace handling is turned off the macros may be used to handle
@@ -2951,27 +2506,29 @@
* (png_uint_16)(alpha) \
+ (png_uint_16)(bg)*(png_uint_16)(255 \
- (png_uint_16)(alpha)) + 128); \
- (composite) = (png_byte)((temp + (temp >> 8)) >> 8); }
+ (composite) = (png_byte)(((temp + (temp >> 8)) >> 8) & 0xff); }
# define png_composite_16(composite, fg, alpha, bg) \
{ png_uint_32 temp = (png_uint_32)((png_uint_32)(fg) \
* (png_uint_32)(alpha) \
+ (png_uint_32)(bg)*(65535 \
- (png_uint_32)(alpha)) + 32768); \
- (composite) = (png_uint_16)((temp + (temp >> 16)) >> 16); }
+ (composite) = (png_uint_16)(0xffff & ((temp + (temp >> 16)) >> 16)); }
#else /* Standard method using integer division */
-# define png_composite(composite, fg, alpha, bg) \
- (composite) = (png_byte)(((png_uint_16)(fg) * (png_uint_16)(alpha) + \
- (png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) + \
- 127) / 255)
+# define png_composite(composite, fg, alpha, bg) \
+ (composite) = \
+ (png_byte)(0xff & (((png_uint_16)(fg) * (png_uint_16)(alpha) + \
+ (png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) + \
+ 127) / 255))
# define png_composite_16(composite, fg, alpha, bg) \
- (composite) = (png_uint_16)(((png_uint_32)(fg) * (png_uint_32)(alpha) + \
- (png_uint_32)(bg)*(png_uint_32)(65535 - (png_uint_32)(alpha)) + \
- 32767) / 65535)
-#endif /* PNG_READ_COMPOSITE_NODIV_SUPPORTED */
+ (composite) = \
+ (png_uint_16)(0xffff & (((png_uint_32)(fg) * (png_uint_32)(alpha) + \
+ (png_uint_32)(bg)*(png_uint_32)(65535 - (png_uint_32)(alpha)) + \
+ 32767) / 65535))
+#endif /* READ_COMPOSITE_NODIV */
#ifdef PNG_READ_INT_FUNCTIONS_SUPPORTED
PNG_EXPORT(201, png_uint_32, png_get_uint_32, (png_const_bytep buf));
@@ -3021,7 +2578,7 @@
# define PNG_get_int_32(buf) \
((png_int_32)((*(buf) & 0x80) \
- ? -((png_int_32)((png_get_uint_32(buf) ^ 0xffffffffL) + 1)) \
+ ? -((png_int_32)(((png_get_uint_32(buf)^0xffffffffU)+1U)&0x7fffffffU)) \
: (png_int_32)png_get_uint_32(buf)))
/* If PNG_PREFIX is defined the same thing as below happens in pnglibconf.h,
@@ -3041,8 +2598,17 @@
# endif
#endif
+#ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED
+PNG_EXPORT(242, void, png_set_check_for_invalid_index,
+ (png_structrp png_ptr, int allowed));
+# ifdef PNG_GET_PALETTE_MAX_SUPPORTED
+PNG_EXPORT(243, int, png_get_palette_max, (png_const_structp png_ptr,
+ png_const_infop info_ptr));
+# endif
+#endif /* CHECK_FOR_INVALID_INDEX */
+
/*******************************************************************************
- * SIMPLIFIED API
+ * Section 5: SIMPLIFIED API
*******************************************************************************
*
* Please read the documentation in libpng-manual.txt (TODO: write said
@@ -3058,8 +2624,9 @@
*
* To read a PNG file using the simplified API:
*
- * 1) Declare a 'png_image' structure (see below) on the stack and set the
- * version field to PNG_IMAGE_VERSION.
+ * 1) Declare a 'png_image' structure (see below) on the stack, set the
+ * version field to PNG_IMAGE_VERSION and the 'opaque' pointer to NULL
+ * (this is REQUIRED, your program may crash if you don't do it.)
* 2) Call the appropriate png_image_begin_read... function.
* 3) Set the png_image 'format' member to the required sample format.
* 4) Allocate a buffer for the image and, if required, the color-map.
@@ -3086,6 +2653,9 @@
* when it is being read or defines the in-memory format of an image that you
* need to write:
*/
+#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) || \
+ defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
+
#define PNG_IMAGE_VERSION 1
typedef struct png_control *png_controlp;
@@ -3112,7 +2682,7 @@
# define PNG_IMAGE_WARNING 1
# define PNG_IMAGE_ERROR 2
/*
- * The result is a two bit code such that a value more than 1 indicates
+ * The result is a two-bit code such that a value more than 1 indicates
* a failure in the API just called:
*
* 0 - no warning or error
@@ -3185,7 +2755,7 @@
* called to read or write the color-map and set the format correctly for the
* image data. Do not set the PNG_FORMAT_FLAG_COLORMAP bit directly!
*
- * NOTE: libpng can be built with particular features disabled, if you see
+ * NOTE: libpng can be built with particular features disabled. If you see
* compiler errors because the definition of one of the following flags has been
* compiled out it is because libpng does not have the required support. It is
* possible, however, for the libpng configuration to enable the format on just
@@ -3197,7 +2767,7 @@
*/
#define PNG_FORMAT_FLAG_ALPHA 0x01U /* format with an alpha channel */
#define PNG_FORMAT_FLAG_COLOR 0x02U /* color format: otherwise grayscale */
-#define PNG_FORMAT_FLAG_LINEAR 0x04U /* 2 byte channels else 1 byte */
+#define PNG_FORMAT_FLAG_LINEAR 0x04U /* 2-byte channels else 1-byte */
#define PNG_FORMAT_FLAG_COLORMAP 0x08U /* image data is color-mapped */
#ifdef PNG_FORMAT_BGR_SUPPORTED
@@ -3397,7 +2967,7 @@
PNG_EXPORT(235, int, png_image_begin_read_from_stdio, (png_imagep image,
FILE* file));
/* The PNG header is read from the stdio FILE object. */
-#endif /* PNG_STDIO_SUPPORTED */
+#endif /* STDIO */
PNG_EXPORT(236, int, png_image_begin_read_from_memory, (png_imagep image,
png_const_voidp memory, png_size_t size));
@@ -3442,7 +3012,7 @@
/* Free any data allocated by libpng in image->opaque, setting the pointer to
* NULL. May be called at any time after the structure is initialized.
*/
-#endif /* PNG_SIMPLIFIED_READ_SUPPORTED */
+#endif /* SIMPLIFIED_READ */
#ifdef PNG_SIMPLIFIED_WRITE_SUPPORTED
#ifdef PNG_STDIO_SUPPORTED
@@ -3484,27 +3054,21 @@
*
* With all APIs row_stride is handled as in the read APIs - it is the spacing
* from one row to the next in component sized units (1 or 2 bytes) and if
- * negative indicates a bottom-up row layout in the buffer.
+ * negative indicates a bottom-up row layout in the buffer. If row_stride is zero,
+ * libpng will calculate it for you from the image width and number of channels.
*
- * Note that the write API does not support interlacing or sub-8-bit pixels.
+ * Note that the write API does not support interlacing, sub-8-bit pixels, indexed
+ * PNG (color_type 3) or most ancillary chunks.
*/
-#endif /* PNG_STDIO_SUPPORTED */
-#endif /* PNG_SIMPLIFIED_WRITE_SUPPORTED */
+#endif /* STDIO */
+#endif /* SIMPLIFIED_WRITE */
/*******************************************************************************
* END OF SIMPLIFIED API
******************************************************************************/
-
-#ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED
-PNG_EXPORT(242, void, png_set_check_for_invalid_index,
- (png_structrp png_ptr, int allowed));
-# ifdef PNG_GET_PALETTE_MAX_SUPPORTED
-PNG_EXPORT(243, int, png_get_palette_max, (png_const_structp png_ptr,
- png_const_infop info_ptr));
-# endif
-#endif /* CHECK_FOR_INVALID_INDEX */
+#endif /* SIMPLIFIED_{READ|WRITE} */
/*******************************************************************************
- * IMPLEMENTATION OPTIONS
+ * Section 6: IMPLEMENTATION OPTIONS
*******************************************************************************
*
* Support for arbitrary implementation-specific optimizations. The API allows
@@ -3529,7 +3093,8 @@
# define PNG_ARM_NEON 0 /* HARDWARE: ARM Neon SIMD instructions supported */
#endif
#define PNG_MAXIMUM_INFLATE_WINDOW 2 /* SOFTWARE: force maximum window */
-#define PNG_OPTION_NEXT 4 /* Next option - numbers must be even */
+#define PNG_SKIP_sRGB_CHECK_PROFILE 4 /* SOFTWARE: Check ICC profile for sRGB */
+#define PNG_OPTION_NEXT 6 /* Next option - numbers must be even */
/* Return values: NOTE: there are four values and 'off' is *not* zero */
#define PNG_OPTION_UNSET 0 /* Unset - defaults to off */
@@ -3539,19 +3104,18 @@
PNG_EXPORT(244, int, png_set_option, (png_structrp png_ptr, int option,
int onoff));
-#endif
+#endif /* SET_OPTION */
/*******************************************************************************
- * END OF HARDWARE OPTIONS
+ * END OF HARDWARE AND SOFTWARE OPTIONS
******************************************************************************/
-/* Maintainer: Put new public prototypes here ^, in libpng.3, and project
- * defs, scripts/pnglibconf.h, and scripts/pnglibconf.h.prebuilt
+/* Maintainer: Put new public prototypes here ^, in libpng.3, in project
+ * defs, and in scripts/symbols.def.
*/
/* The last ordinal number (this is the *last* one already used; the next
- * one to use is one more than this.) Maintainer, remember to add an entry to
- * scripts/symbols.def as well.
+ * one to use is one more than this.)
*/
#ifdef PNG_EXPORT_LAST_ORDINAL
PNG_EXPORT_LAST_ORDINAL(244);
diff --git a/third_party/lpng_v163/pngconf.h b/third_party/libpng/pngconf.h
similarity index 91%
rename from third_party/lpng_v163/pngconf.h
rename to third_party/libpng/pngconf.h
index 02f74e2..92f2500 100644
--- a/third_party/lpng_v163/pngconf.h
+++ b/third_party/libpng/pngconf.h
@@ -1,617 +1,622 @@
-
-/* pngconf.h - machine configurable file for libpng
- *
- * libpng version 1.6.3 - July 18, 2013
- *
- * Copyright (c) 1998-2013 Glenn Randers-Pehrson
- * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
- * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
- *
- * This code is released under the libpng license.
- * For conditions of distribution and use, see the disclaimer
- * and license in png.h
- *
- */
-
-/* Any machine specific code is near the front of this file, so if you
- * are configuring libpng for a machine, you may want to read the section
- * starting here down to where it starts to typedef png_color, png_text,
- * and png_info.
- */
-
-#ifndef PNGCONF_H
-#define PNGCONF_H
-
-/* To do: Do all of this in scripts/pnglibconf.dfa */
-#ifdef PNG_SAFE_LIMITS_SUPPORTED
-# ifdef PNG_USER_WIDTH_MAX
-# undef PNG_USER_WIDTH_MAX
-# define PNG_USER_WIDTH_MAX 1000000L
-# endif
-# ifdef PNG_USER_HEIGHT_MAX
-# undef PNG_USER_HEIGHT_MAX
-# define PNG_USER_HEIGHT_MAX 1000000L
-# endif
-# ifdef PNG_USER_CHUNK_MALLOC_MAX
-# undef PNG_USER_CHUNK_MALLOC_MAX
-# define PNG_USER_CHUNK_MALLOC_MAX 4000000L
-# endif
-# ifdef PNG_USER_CHUNK_CACHE_MAX
-# undef PNG_USER_CHUNK_CACHE_MAX
-# define PNG_USER_CHUNK_CACHE_MAX 128
-# endif
-#endif
-
-#ifndef PNG_BUILDING_SYMBOL_TABLE /* else includes may cause problems */
-
-/* From libpng 1.6.0 libpng requires an ANSI X3.159-1989 ("ISOC90") compliant C
- * compiler for correct compilation. The following header files are required by
- * the standard. If your compiler doesn't provide these header files, or they
- * do not match the standard, you will need to provide/improve them.
- */
-#include <limits.h>
-#include <stddef.h>
-
-/* Library header files. These header files are all defined by ISOC90; libpng
- * expects conformant implementations, however, an ISOC90 conformant system need
- * not provide these header files if the functionality cannot be implemented.
- * In this case it will be necessary to disable the relevant parts of libpng in
- * the build of pnglibconf.h.
- *
- * Prior to 1.6.0 string.h was included here; the API changes in 1.6.0 to not
- * include this unnecessary header file.
- */
-
-#ifdef PNG_STDIO_SUPPORTED
- /* Required for the definition of FILE: */
-# include <stdio.h>
-#endif
-
-#ifdef PNG_SETJMP_SUPPORTED
- /* Required for the definition of jmp_buf and the declaration of longjmp: */
-# include <setjmp.h>
-#endif
-
-#ifdef PNG_CONVERT_tIME_SUPPORTED
- /* Required for struct tm: */
-# include <time.h>
-#endif
-
-#endif /* PNG_BUILDING_SYMBOL_TABLE */
-
-/* Prior to 1.6.0 it was possible to turn off 'const' in declarations using
- * PNG_NO_CONST; this is no longer supported except for data declarations which
- * apparently still cause problems in 2011 on some compilers.
- */
-#define PNG_CONST const /* backward compatibility only */
-
-/* This controls optimization of the reading of 16 and 32 bit values
- * from PNG files. It can be set on a per-app-file basis - it
- * just changes whether a macro is used when the function is called.
- * The library builder sets the default; if read functions are not
- * built into the library the macro implementation is forced on.
- */
-#ifndef PNG_READ_INT_FUNCTIONS_SUPPORTED
-# define PNG_USE_READ_MACROS
-#endif
-#if !defined(PNG_NO_USE_READ_MACROS) && !defined(PNG_USE_READ_MACROS)
-# if PNG_DEFAULT_READ_MACROS
-# define PNG_USE_READ_MACROS
-# endif
-#endif
-
-/* COMPILER SPECIFIC OPTIONS.
- *
- * These options are provided so that a variety of difficult compilers
- * can be used. Some are fixed at build time (e.g. PNG_API_RULE
- * below) but still have compiler specific implementations, others
- * may be changed on a per-file basis when compiling against libpng.
- */
-
-/* The PNGARG macro was used in versions of libpng prior to 1.6.0 to protect
- * against legacy (pre ISOC90) compilers that did not understand function
- * prototypes. It is not required for modern C compilers.
- */
-#ifndef PNGARG
-# define PNGARG(arglist) arglist
-#endif
-
-/* Function calling conventions.
- * =============================
- * Normally it is not necessary to specify to the compiler how to call
- * a function - it just does it - however on x86 systems derived from
- * Microsoft and Borland C compilers ('IBM PC', 'DOS', 'Windows' systems
- * and some others) there are multiple ways to call a function and the
- * default can be changed on the compiler command line. For this reason
- * libpng specifies the calling convention of every exported function and
- * every function called via a user supplied function pointer. This is
- * done in this file by defining the following macros:
- *
- * PNGAPI Calling convention for exported functions.
- * PNGCBAPI Calling convention for user provided (callback) functions.
- * PNGCAPI Calling convention used by the ANSI-C library (required
- * for longjmp callbacks and sometimes used internally to
- * specify the calling convention for zlib).
- *
- * These macros should never be overridden. If it is necessary to
- * change calling convention in a private build this can be done
- * by setting PNG_API_RULE (which defaults to 0) to one of the values
- * below to select the correct 'API' variants.
- *
- * PNG_API_RULE=0 Use PNGCAPI - the 'C' calling convention - throughout.
- * This is correct in every known environment.
- * PNG_API_RULE=1 Use the operating system convention for PNGAPI and
- * the 'C' calling convention (from PNGCAPI) for
- * callbacks (PNGCBAPI). This is no longer required
- * in any known environment - if it has to be used
- * please post an explanation of the problem to the
- * libpng mailing list.
- *
- * These cases only differ if the operating system does not use the C
- * calling convention, at present this just means the above cases
- * (x86 DOS/Windows sytems) and, even then, this does not apply to
- * Cygwin running on those systems.
- *
- * Note that the value must be defined in pnglibconf.h so that what
- * the application uses to call the library matches the conventions
- * set when building the library.
- */
-
-/* Symbol export
- * =============
- * When building a shared library it is almost always necessary to tell
- * the compiler which symbols to export. The png.h macro 'PNG_EXPORT'
- * is used to mark the symbols. On some systems these symbols can be
- * extracted at link time and need no special processing by the compiler,
- * on other systems the symbols are flagged by the compiler and just
- * the declaration requires a special tag applied (unfortunately) in a
- * compiler dependent way. Some systems can do either.
- *
- * A small number of older systems also require a symbol from a DLL to
- * be flagged to the program that calls it. This is a problem because
- * we do not know in the header file included by application code that
- * the symbol will come from a shared library, as opposed to a statically
- * linked one. For this reason the application must tell us by setting
- * the magic flag PNG_USE_DLL to turn on the special processing before
- * it includes png.h.
- *
- * Four additional macros are used to make this happen:
- *
- * PNG_IMPEXP The magic (if any) to cause a symbol to be exported from
- * the build or imported if PNG_USE_DLL is set - compiler
- * and system specific.
- *
- * PNG_EXPORT_TYPE(type) A macro that pre or appends PNG_IMPEXP to
- * 'type', compiler specific.
- *
- * PNG_DLL_EXPORT Set to the magic to use during a libpng build to
- * make a symbol exported from the DLL. Not used in the
- * public header files; see pngpriv.h for how it is used
- * in the libpng build.
- *
- * PNG_DLL_IMPORT Set to the magic to force the libpng symbols to come
- * from a DLL - used to define PNG_IMPEXP when
- * PNG_USE_DLL is set.
- */
-
-/* System specific discovery.
- * ==========================
- * This code is used at build time to find PNG_IMPEXP, the API settings
- * and PNG_EXPORT_TYPE(), it may also set a macro to indicate the DLL
- * import processing is possible. On Windows systems it also sets
- * compiler-specific macros to the values required to change the calling
- * conventions of the various functions.
- */
-#if defined(_Windows) || defined(_WINDOWS) || defined(WIN32) ||\
- defined(_WIN32) || defined(__WIN32__) || defined(__CYGWIN__)
- /* Windows system (DOS doesn't support DLLs). Includes builds under Cygwin or
- * MinGW on any architecture currently supported by Windows. Also includes
- * Watcom builds but these need special treatment because they are not
- * compatible with GCC or Visual C because of different calling conventions.
- */
-# if PNG_API_RULE == 2
- /* If this line results in an error, either because __watcall is not
- * understood or because of a redefine just below you cannot use *this*
- * build of the library with the compiler you are using. *This* build was
- * build using Watcom and applications must also be built using Watcom!
- */
-# define PNGCAPI __watcall
-# endif
-
-# if defined(__GNUC__) || (defined(_MSC_VER) && (_MSC_VER >= 800))
-# define PNGCAPI __cdecl
-# if PNG_API_RULE == 1
- /* If this line results in an error __stdcall is not understood and
- * PNG_API_RULE should not have been set to '1'.
- */
-# define PNGAPI __stdcall
-# endif
-# else
- /* An older compiler, or one not detected (erroneously) above,
- * if necessary override on the command line to get the correct
- * variants for the compiler.
- */
-# ifndef PNGCAPI
-# define PNGCAPI _cdecl
-# endif
-# if PNG_API_RULE == 1 && !defined(PNGAPI)
-# define PNGAPI _stdcall
-# endif
-# endif /* compiler/api */
-
- /* NOTE: PNGCBAPI always defaults to PNGCAPI. */
-
-# if defined(PNGAPI) && !defined(PNG_USER_PRIVATEBUILD)
-# error "PNG_USER_PRIVATEBUILD must be defined if PNGAPI is changed"
-# endif
-
-# if (defined(_MSC_VER) && _MSC_VER < 800) ||\
- (defined(__BORLANDC__) && __BORLANDC__ < 0x500)
- /* older Borland and MSC
- * compilers used '__export' and required this to be after
- * the type.
- */
-# ifndef PNG_EXPORT_TYPE
-# define PNG_EXPORT_TYPE(type) type PNG_IMPEXP
-# endif
-# define PNG_DLL_EXPORT __export
-# else /* newer compiler */
-# define PNG_DLL_EXPORT __declspec(dllexport)
-# ifndef PNG_DLL_IMPORT
-# define PNG_DLL_IMPORT __declspec(dllimport)
-# endif
-# endif /* compiler */
-
-#else /* !Windows */
-# if (defined(__IBMC__) || defined(__IBMCPP__)) && defined(__OS2__)
-# define PNGAPI _System
-# else /* !Windows/x86 && !OS/2 */
- /* Use the defaults, or define PNG*API on the command line (but
- * this will have to be done for every compile!)
- */
-# endif /* other system, !OS/2 */
-#endif /* !Windows/x86 */
-
-/* Now do all the defaulting . */
-#ifndef PNGCAPI
-# define PNGCAPI
-#endif
-#ifndef PNGCBAPI
-# define PNGCBAPI PNGCAPI
-#endif
-#ifndef PNGAPI
-# define PNGAPI PNGCAPI
-#endif
-
-/* PNG_IMPEXP may be set on the compilation system command line or (if not set)
- * then in an internal header file when building the library, otherwise (when
- * using the library) it is set here.
- */
-#ifndef PNG_IMPEXP
-# if defined(PNG_USE_DLL) && defined(PNG_DLL_IMPORT)
- /* This forces use of a DLL, disallowing static linking */
-# define PNG_IMPEXP PNG_DLL_IMPORT
-# endif
-
-# ifndef PNG_IMPEXP
-# define PNG_IMPEXP
-# endif
-#endif
-
-/* In 1.5.2 the definition of PNG_FUNCTION has been changed to always treat
- * 'attributes' as a storage class - the attributes go at the start of the
- * function definition, and attributes are always appended regardless of the
- * compiler. This considerably simplifies these macros but may cause problems
- * if any compilers both need function attributes and fail to handle them as
- * a storage class (this is unlikely.)
- */
-#ifndef PNG_FUNCTION
-# define PNG_FUNCTION(type, name, args, attributes) attributes type name args
-#endif
-
-#ifndef PNG_EXPORT_TYPE
-# define PNG_EXPORT_TYPE(type) PNG_IMPEXP type
-#endif
-
- /* The ordinal value is only relevant when preprocessing png.h for symbol
- * table entries, so we discard it here. See the .dfn files in the
- * scripts directory.
- */
-#ifndef PNG_EXPORTA
-
-# define PNG_EXPORTA(ordinal, type, name, args, attributes)\
- PNG_FUNCTION(PNG_EXPORT_TYPE(type),(PNGAPI name),PNGARG(args), \
- extern attributes)
-#endif
-
-/* ANSI-C (C90) does not permit a macro to be invoked with an empty argument,
- * so make something non-empty to satisfy the requirement:
- */
-#define PNG_EMPTY /*empty list*/
-
-#define PNG_EXPORT(ordinal, type, name, args)\
- PNG_EXPORTA(ordinal, type, name, args, PNG_EMPTY)
-
-/* Use PNG_REMOVED to comment out a removed interface. */
-#ifndef PNG_REMOVED
-# define PNG_REMOVED(ordinal, type, name, args, attributes)
-#endif
-
-#ifndef PNG_CALLBACK
-# define PNG_CALLBACK(type, name, args) type (PNGCBAPI name) PNGARG(args)
-#endif
-
-/* Support for compiler specific function attributes. These are used
- * so that where compiler support is available incorrect use of API
- * functions in png.h will generate compiler warnings.
- *
- * Added at libpng-1.2.41.
- */
-
-#ifndef PNG_NO_PEDANTIC_WARNINGS
-# ifndef PNG_PEDANTIC_WARNINGS_SUPPORTED
-# define PNG_PEDANTIC_WARNINGS_SUPPORTED
-# endif
-#endif
-
-#ifdef PNG_PEDANTIC_WARNINGS_SUPPORTED
- /* Support for compiler specific function attributes. These are used
- * so that where compiler support is available, incorrect use of API
- * functions in png.h will generate compiler warnings. Added at libpng
- * version 1.2.41. Disabling these removes the warnings but may also produce
- * less efficient code.
- */
-# if defined(__GNUC__)
-# ifndef PNG_USE_RESULT
-# define PNG_USE_RESULT __attribute__((__warn_unused_result__))
-# endif
-# ifndef PNG_NORETURN
-# define PNG_NORETURN __attribute__((__noreturn__))
-# endif
-# if __GNUC__ >= 3
-# ifndef PNG_ALLOCATED
-# define PNG_ALLOCATED __attribute__((__malloc__))
-# endif
-# ifndef PNG_DEPRECATED
-# define PNG_DEPRECATED __attribute__((__deprecated__))
-# endif
-# ifndef PNG_PRIVATE
-# if 0 /* Doesn't work so we use deprecated instead*/
-# define PNG_PRIVATE \
- __attribute__((warning("This function is not exported by libpng.")))
-# else
-# define PNG_PRIVATE \
- __attribute__((__deprecated__))
-# endif
-# endif
-# if ((__GNUC__ != 3) || !defined(__GNUC_MINOR__) || (__GNUC_MINOR__ >= 1))
-# ifndef PNG_RESTRICT
-# define PNG_RESTRICT __restrict
-# endif
-# endif /* __GNUC__ == 3.0 */
-# endif /* __GNUC__ >= 3 */
-
-# elif defined(_MSC_VER) && (_MSC_VER >= 1300)
-# ifndef PNG_USE_RESULT
-# define PNG_USE_RESULT /* not supported */
-# endif
-# ifndef PNG_NORETURN
-# define PNG_NORETURN __declspec(noreturn)
-# endif
-# ifndef PNG_ALLOCATED
-# if (_MSC_VER >= 1400)
-# define PNG_ALLOCATED __declspec(restrict)
-# endif
-# endif
-# ifndef PNG_DEPRECATED
-# define PNG_DEPRECATED __declspec(deprecated)
-# endif
-# ifndef PNG_PRIVATE
-# define PNG_PRIVATE __declspec(deprecated)
-# endif
-# ifndef PNG_RESTRICT
-# if (_MSC_VER >= 1400)
-# define PNG_RESTRICT __restrict
-# endif
-# endif
-
-# elif defined(__WATCOMC__)
-# ifndef PNG_RESTRICT
-# define PNG_RESTRICT __restrict
-# endif
-# endif /* _MSC_VER */
-#endif /* PNG_PEDANTIC_WARNINGS */
-
-#ifndef PNG_DEPRECATED
-# define PNG_DEPRECATED /* Use of this function is deprecated */
-#endif
-#ifndef PNG_USE_RESULT
-# define PNG_USE_RESULT /* The result of this function must be checked */
-#endif
-#ifndef PNG_NORETURN
-# define PNG_NORETURN /* This function does not return */
-#endif
-#ifndef PNG_ALLOCATED
-# define PNG_ALLOCATED /* The result of the function is new memory */
-#endif
-#ifndef PNG_PRIVATE
-# define PNG_PRIVATE /* This is a private libpng function */
-#endif
-#ifndef PNG_RESTRICT
-# define PNG_RESTRICT /* The C99 "restrict" feature */
-#endif
-#ifndef PNG_FP_EXPORT /* A floating point API. */
-# ifdef PNG_FLOATING_POINT_SUPPORTED
-# define PNG_FP_EXPORT(ordinal, type, name, args)\
- PNG_EXPORT(ordinal, type, name, args);
-# else /* No floating point APIs */
-# define PNG_FP_EXPORT(ordinal, type, name, args)
-# endif
-#endif
-#ifndef PNG_FIXED_EXPORT /* A fixed point API. */
-# ifdef PNG_FIXED_POINT_SUPPORTED
-# define PNG_FIXED_EXPORT(ordinal, type, name, args)\
- PNG_EXPORT(ordinal, type, name, args);
-# else /* No fixed point APIs */
-# define PNG_FIXED_EXPORT(ordinal, type, name, args)
-# endif
-#endif
-
-#ifndef PNG_BUILDING_SYMBOL_TABLE
-/* Some typedefs to get us started. These should be safe on most of the common
- * platforms.
- *
- * png_uint_32 and png_int_32 may, currently, be larger than required to hold a
- * 32-bit value however this is not normally advisable.
- *
- * png_uint_16 and png_int_16 should always be two bytes in size - this is
- * verified at library build time.
- *
- * png_byte must always be one byte in size.
- *
- * The checks below use constants from limits.h, as defined by the ISOC90
- * standard.
- */
-#if CHAR_BIT == 8 && UCHAR_MAX == 255
- typedef unsigned char png_byte;
-#else
-# error "libpng requires 8 bit bytes"
-#endif
-
-#if INT_MIN == -32768 && INT_MAX == 32767
- typedef int png_int_16;
-#elif SHRT_MIN == -32768 && SHRT_MAX == 32767
- typedef short png_int_16;
-#else
-# error "libpng requires a signed 16 bit type"
-#endif
-
-#if UINT_MAX == 65535
- typedef unsigned int png_uint_16;
-#elif USHRT_MAX == 65535
- typedef unsigned short png_uint_16;
-#else
-# error "libpng requires an unsigned 16 bit type"
-#endif
-
-#if INT_MIN < -2147483646 && INT_MAX > 2147483646
- typedef int png_int_32;
-#elif LONG_MIN < -2147483646 && LONG_MAX > 2147483646
- typedef long int png_int_32;
-#else
-# error "libpng requires a signed 32 bit (or more) type"
-#endif
-
-#if UINT_MAX > 4294967294
- typedef unsigned int png_uint_32;
-#elif ULONG_MAX > 4294967294
- typedef unsigned long int png_uint_32;
-#else
-# error "libpng requires an unsigned 32 bit (or more) type"
-#endif
-
-/* Prior to 1.6.0 it was possible to disable the use of size_t, 1.6.0, however,
- * requires an ISOC90 compiler and relies on consistent behavior of sizeof.
- */
-typedef size_t png_size_t;
-typedef ptrdiff_t png_ptrdiff_t;
-
-/* libpng needs to know the maximum value of 'size_t' and this controls the
- * definition of png_alloc_size_t, below. This maximum value of size_t limits
- * but does not control the maximum allocations the library makes - there is
- * direct application control of this through png_set_user_limits().
- */
-#ifndef PNG_SMALL_SIZE_T
- /* Compiler specific tests for systems where size_t is known to be less than
- * 32 bits (some of these systems may no longer work because of the lack of
- * 'far' support; see above.)
- */
-# if (defined(__TURBOC__) && !defined(__FLAT__)) ||\
- (defined(_MSC_VER) && defined(MAXSEG_64K))
-# define PNG_SMALL_SIZE_T
-# endif
-#endif
-
-/* png_alloc_size_t is guaranteed to be no smaller than png_size_t, and no
- * smaller than png_uint_32. Casts from png_size_t or png_uint_32 to
- * png_alloc_size_t are not necessary; in fact, it is recommended not to use
- * them at all so that the compiler can complain when something turns out to be
- * problematic.
- *
- * Casts in the other direction (from png_alloc_size_t to png_size_t or
- * png_uint_32) should be explicitly applied; however, we do not expect to
- * encounter practical situations that require such conversions.
- *
- * PNG_SMALL_SIZE_T must be defined if the maximum value of size_t is less than
- * 4294967295 - i.e. less than the maximum value of png_uint_32.
- */
-#ifdef PNG_SMALL_SIZE_T
- typedef png_uint_32 png_alloc_size_t;
-#else
- typedef png_size_t png_alloc_size_t;
-#endif
-
-/* Prior to 1.6.0 libpng offered limited support for Microsoft C compiler
- * implementations of Intel CPU specific support of user-mode segmented address
- * spaces, where 16-bit pointers address more than 65536 bytes of memory using
- * separate 'segment' registers. The implementation requires two different
- * types of pointer (only one of which includes the segment value.)
- *
- * If required this support is available in version 1.2 of libpng and may be
- * available in versions through 1.5, although the correctness of the code has
- * not been verified recently.
- */
-
-/* Typedef for floating-point numbers that are converted to fixed-point with a
- * multiple of 100,000, e.g., gamma
- */
-typedef png_int_32 png_fixed_point;
-
-/* Add typedefs for pointers */
-typedef void * png_voidp;
-typedef const void * png_const_voidp;
-typedef png_byte * png_bytep;
-typedef const png_byte * png_const_bytep;
-typedef png_uint_32 * png_uint_32p;
-typedef const png_uint_32 * png_const_uint_32p;
-typedef png_int_32 * png_int_32p;
-typedef const png_int_32 * png_const_int_32p;
-typedef png_uint_16 * png_uint_16p;
-typedef const png_uint_16 * png_const_uint_16p;
-typedef png_int_16 * png_int_16p;
-typedef const png_int_16 * png_const_int_16p;
-typedef char * png_charp;
-typedef const char * png_const_charp;
-typedef png_fixed_point * png_fixed_point_p;
-typedef const png_fixed_point * png_const_fixed_point_p;
-typedef png_size_t * png_size_tp;
-typedef const png_size_t * png_const_size_tp;
-
-#ifdef PNG_STDIO_SUPPORTED
-typedef FILE * png_FILE_p;
-#endif
-
-#ifdef PNG_FLOATING_POINT_SUPPORTED
-typedef double * png_doublep;
-typedef const double * png_const_doublep;
-#endif
-
-/* Pointers to pointers; i.e. arrays */
-typedef png_byte * * png_bytepp;
-typedef png_uint_32 * * png_uint_32pp;
-typedef png_int_32 * * png_int_32pp;
-typedef png_uint_16 * * png_uint_16pp;
-typedef png_int_16 * * png_int_16pp;
-typedef const char * * png_const_charpp;
-typedef char * * png_charpp;
-typedef png_fixed_point * * png_fixed_point_pp;
-#ifdef PNG_FLOATING_POINT_SUPPORTED
-typedef double * * png_doublepp;
-#endif
-
-/* Pointers to pointers to pointers; i.e., pointer to array */
-typedef char * * * png_charppp;
-
-#endif /* PNG_BUILDING_SYMBOL_TABLE */
-
-#endif /* PNGCONF_H */
+
+/* pngconf.h - machine configurable file for libpng
+ *
+ * libpng version 1.6.20, December 3, 2015
+ *
+ * Copyright (c) 1998-2015 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ * Any machine specific code is near the front of this file, so if you
+ * are configuring libpng for a machine, you may want to read the section
+ * starting here down to where it starts to typedef png_color, png_text,
+ * and png_info.
+ */
+
+#ifndef PNGCONF_H
+#define PNGCONF_H
+
+#ifndef PNG_BUILDING_SYMBOL_TABLE /* else includes may cause problems */
+
+/* From libpng 1.6.0 libpng requires an ANSI X3.159-1989 ("ISOC90") compliant C
+ * compiler for correct compilation. The following header files are required by
+ * the standard. If your compiler doesn't provide these header files, or they
+ * do not match the standard, you will need to provide/improve them.
+ */
+#include <limits.h>
+#include <stddef.h>
+
+/* Library header files. These header files are all defined by ISOC90; libpng
+ * expects conformant implementations, however, an ISOC90 conformant system need
+ * not provide these header files if the functionality cannot be implemented.
+ * In this case it will be necessary to disable the relevant parts of libpng in
+ * the build of pnglibconf.h.
+ *
+ * Prior to 1.6.0 string.h was included here; the API changes in 1.6.0 to not
+ * include this unnecessary header file.
+ */
+
+#ifdef PNG_STDIO_SUPPORTED
+ /* Required for the definition of FILE: */
+# include <stdio.h>
+#endif
+
+#ifdef PNG_SETJMP_SUPPORTED
+ /* Required for the definition of jmp_buf and the declaration of longjmp: */
+# include <setjmp.h>
+#endif
+
+#ifdef PNG_CONVERT_tIME_SUPPORTED
+ /* Required for struct tm: */
+# include <time.h>
+#endif
+
+#endif /* PNG_BUILDING_SYMBOL_TABLE */
+
+/* Prior to 1.6.0 it was possible to turn off 'const' in declarations using
+ * PNG_NO_CONST; this is no longer supported except for data declarations which
+ * apparently still cause problems in 2011 on some compilers.
+ */
+#define PNG_CONST const /* backward compatibility only */
+
+/* This controls optimization of the reading of 16-bit and 32-bit values
+ * from PNG files. It can be set on a per-app-file basis - it
+ * just changes whether a macro is used when the function is called.
+ * The library builder sets the default; if read functions are not
+ * built into the library the macro implementation is forced on.
+ */
+#ifndef PNG_READ_INT_FUNCTIONS_SUPPORTED
+# define PNG_USE_READ_MACROS
+#endif
+#if !defined(PNG_NO_USE_READ_MACROS) && !defined(PNG_USE_READ_MACROS)
+# if PNG_DEFAULT_READ_MACROS
+# define PNG_USE_READ_MACROS
+# endif
+#endif
+
+/* COMPILER SPECIFIC OPTIONS.
+ *
+ * These options are provided so that a variety of difficult compilers
+ * can be used. Some are fixed at build time (e.g. PNG_API_RULE
+ * below) but still have compiler specific implementations, others
+ * may be changed on a per-file basis when compiling against libpng.
+ */
+
+/* The PNGARG macro was used in versions of libpng prior to 1.6.0 to protect
+ * against legacy (pre ISOC90) compilers that did not understand function
+ * prototypes. It is not required for modern C compilers.
+ */
+#ifndef PNGARG
+# define PNGARG(arglist) arglist
+#endif
+
+/* Function calling conventions.
+ * =============================
+ * Normally it is not necessary to specify to the compiler how to call
+ * a function - it just does it - however on x86 systems derived from
+ * Microsoft and Borland C compilers ('IBM PC', 'DOS', 'Windows' systems
+ * and some others) there are multiple ways to call a function and the
+ * default can be changed on the compiler command line. For this reason
+ * libpng specifies the calling convention of every exported function and
+ * every function called via a user supplied function pointer. This is
+ * done in this file by defining the following macros:
+ *
+ * PNGAPI Calling convention for exported functions.
+ * PNGCBAPI Calling convention for user provided (callback) functions.
+ * PNGCAPI Calling convention used by the ANSI-C library (required
+ * for longjmp callbacks and sometimes used internally to
+ * specify the calling convention for zlib).
+ *
+ * These macros should never be overridden. If it is necessary to
+ * change calling convention in a private build this can be done
+ * by setting PNG_API_RULE (which defaults to 0) to one of the values
+ * below to select the correct 'API' variants.
+ *
+ * PNG_API_RULE=0 Use PNGCAPI - the 'C' calling convention - throughout.
+ * This is correct in every known environment.
+ * PNG_API_RULE=1 Use the operating system convention for PNGAPI and
+ * the 'C' calling convention (from PNGCAPI) for
+ * callbacks (PNGCBAPI). This is no longer required
+ * in any known environment - if it has to be used
+ * please post an explanation of the problem to the
+ * libpng mailing list.
+ *
+ * These cases only differ if the operating system does not use the C
+ * calling convention, at present this just means the above cases
+ * (x86 DOS/Windows sytems) and, even then, this does not apply to
+ * Cygwin running on those systems.
+ *
+ * Note that the value must be defined in pnglibconf.h so that what
+ * the application uses to call the library matches the conventions
+ * set when building the library.
+ */
+
+/* Symbol export
+ * =============
+ * When building a shared library it is almost always necessary to tell
+ * the compiler which symbols to export. The png.h macro 'PNG_EXPORT'
+ * is used to mark the symbols. On some systems these symbols can be
+ * extracted at link time and need no special processing by the compiler,
+ * on other systems the symbols are flagged by the compiler and just
+ * the declaration requires a special tag applied (unfortunately) in a
+ * compiler dependent way. Some systems can do either.
+ *
+ * A small number of older systems also require a symbol from a DLL to
+ * be flagged to the program that calls it. This is a problem because
+ * we do not know in the header file included by application code that
+ * the symbol will come from a shared library, as opposed to a statically
+ * linked one. For this reason the application must tell us by setting
+ * the magic flag PNG_USE_DLL to turn on the special processing before
+ * it includes png.h.
+ *
+ * Four additional macros are used to make this happen:
+ *
+ * PNG_IMPEXP The magic (if any) to cause a symbol to be exported from
+ * the build or imported if PNG_USE_DLL is set - compiler
+ * and system specific.
+ *
+ * PNG_EXPORT_TYPE(type) A macro that pre or appends PNG_IMPEXP to
+ * 'type', compiler specific.
+ *
+ * PNG_DLL_EXPORT Set to the magic to use during a libpng build to
+ * make a symbol exported from the DLL. Not used in the
+ * public header files; see pngpriv.h for how it is used
+ * in the libpng build.
+ *
+ * PNG_DLL_IMPORT Set to the magic to force the libpng symbols to come
+ * from a DLL - used to define PNG_IMPEXP when
+ * PNG_USE_DLL is set.
+ */
+
+/* System specific discovery.
+ * ==========================
+ * This code is used at build time to find PNG_IMPEXP, the API settings
+ * and PNG_EXPORT_TYPE(), it may also set a macro to indicate the DLL
+ * import processing is possible. On Windows systems it also sets
+ * compiler-specific macros to the values required to change the calling
+ * conventions of the various functions.
+ */
+#if defined(_Windows) || defined(_WINDOWS) || defined(WIN32) ||\
+ defined(_WIN32) || defined(__WIN32__) || defined(__CYGWIN__)
+ /* Windows system (DOS doesn't support DLLs). Includes builds under Cygwin or
+ * MinGW on any architecture currently supported by Windows. Also includes
+ * Watcom builds but these need special treatment because they are not
+ * compatible with GCC or Visual C because of different calling conventions.
+ */
+# if PNG_API_RULE == 2
+ /* If this line results in an error, either because __watcall is not
+ * understood or because of a redefine just below you cannot use *this*
+ * build of the library with the compiler you are using. *This* build was
+ * build using Watcom and applications must also be built using Watcom!
+ */
+# define PNGCAPI __watcall
+# endif
+
+# if defined(__GNUC__) || (defined(_MSC_VER) && (_MSC_VER >= 800))
+# define PNGCAPI __cdecl
+# if PNG_API_RULE == 1
+ /* If this line results in an error __stdcall is not understood and
+ * PNG_API_RULE should not have been set to '1'.
+ */
+# define PNGAPI __stdcall
+# endif
+# else
+ /* An older compiler, or one not detected (erroneously) above,
+ * if necessary override on the command line to get the correct
+ * variants for the compiler.
+ */
+# ifndef PNGCAPI
+# define PNGCAPI _cdecl
+# endif
+# if PNG_API_RULE == 1 && !defined(PNGAPI)
+# define PNGAPI _stdcall
+# endif
+# endif /* compiler/api */
+
+ /* NOTE: PNGCBAPI always defaults to PNGCAPI. */
+
+# if defined(PNGAPI) && !defined(PNG_USER_PRIVATEBUILD)
+# error "PNG_USER_PRIVATEBUILD must be defined if PNGAPI is changed"
+# endif
+
+# if (defined(_MSC_VER) && _MSC_VER < 800) ||\
+ (defined(__BORLANDC__) && __BORLANDC__ < 0x500)
+ /* older Borland and MSC
+ * compilers used '__export' and required this to be after
+ * the type.
+ */
+# ifndef PNG_EXPORT_TYPE
+# define PNG_EXPORT_TYPE(type) type PNG_IMPEXP
+# endif
+# define PNG_DLL_EXPORT __export
+# else /* newer compiler */
+# define PNG_DLL_EXPORT __declspec(dllexport)
+# ifndef PNG_DLL_IMPORT
+# define PNG_DLL_IMPORT __declspec(dllimport)
+# endif
+# endif /* compiler */
+
+#else /* !Windows */
+# if (defined(__IBMC__) || defined(__IBMCPP__)) && defined(__OS2__)
+# define PNGAPI _System
+# else /* !Windows/x86 && !OS/2 */
+ /* Use the defaults, or define PNG*API on the command line (but
+ * this will have to be done for every compile!)
+ */
+# endif /* other system, !OS/2 */
+#endif /* !Windows/x86 */
+
+/* Now do all the defaulting . */
+#ifndef PNGCAPI
+# define PNGCAPI
+#endif
+#ifndef PNGCBAPI
+# define PNGCBAPI PNGCAPI
+#endif
+#ifndef PNGAPI
+# define PNGAPI PNGCAPI
+#endif
+
+/* PNG_IMPEXP may be set on the compilation system command line or (if not set)
+ * then in an internal header file when building the library, otherwise (when
+ * using the library) it is set here.
+ */
+#ifndef PNG_IMPEXP
+# if defined(PNG_USE_DLL) && defined(PNG_DLL_IMPORT)
+ /* This forces use of a DLL, disallowing static linking */
+# define PNG_IMPEXP PNG_DLL_IMPORT
+# endif
+
+# ifndef PNG_IMPEXP
+# define PNG_IMPEXP
+# endif
+#endif
+
+/* In 1.5.2 the definition of PNG_FUNCTION has been changed to always treat
+ * 'attributes' as a storage class - the attributes go at the start of the
+ * function definition, and attributes are always appended regardless of the
+ * compiler. This considerably simplifies these macros but may cause problems
+ * if any compilers both need function attributes and fail to handle them as
+ * a storage class (this is unlikely.)
+ */
+#ifndef PNG_FUNCTION
+# define PNG_FUNCTION(type, name, args, attributes) attributes type name args
+#endif
+
+#ifndef PNG_EXPORT_TYPE
+# define PNG_EXPORT_TYPE(type) PNG_IMPEXP type
+#endif
+
+ /* The ordinal value is only relevant when preprocessing png.h for symbol
+ * table entries, so we discard it here. See the .dfn files in the
+ * scripts directory.
+ */
+
+#ifndef PNG_EXPORTA
+# define PNG_EXPORTA(ordinal, type, name, args, attributes) \
+ PNG_FUNCTION(PNG_EXPORT_TYPE(type), (PNGAPI name), PNGARG(args), \
+ PNG_LINKAGE_API attributes)
+#endif
+
+/* ANSI-C (C90) does not permit a macro to be invoked with an empty argument,
+ * so make something non-empty to satisfy the requirement:
+ */
+#define PNG_EMPTY /*empty list*/
+
+#define PNG_EXPORT(ordinal, type, name, args) \
+ PNG_EXPORTA(ordinal, type, name, args, PNG_EMPTY)
+
+/* Use PNG_REMOVED to comment out a removed interface. */
+#ifndef PNG_REMOVED
+# define PNG_REMOVED(ordinal, type, name, args, attributes)
+#endif
+
+#ifndef PNG_CALLBACK
+# define PNG_CALLBACK(type, name, args) type (PNGCBAPI name) PNGARG(args)
+#endif
+
+/* Support for compiler specific function attributes. These are used
+ * so that where compiler support is available incorrect use of API
+ * functions in png.h will generate compiler warnings.
+ *
+ * Added at libpng-1.2.41.
+ */
+
+#ifndef PNG_NO_PEDANTIC_WARNINGS
+# ifndef PNG_PEDANTIC_WARNINGS_SUPPORTED
+# define PNG_PEDANTIC_WARNINGS_SUPPORTED
+# endif
+#endif
+
+#ifdef PNG_PEDANTIC_WARNINGS_SUPPORTED
+ /* Support for compiler specific function attributes. These are used
+ * so that where compiler support is available, incorrect use of API
+ * functions in png.h will generate compiler warnings. Added at libpng
+ * version 1.2.41. Disabling these removes the warnings but may also produce
+ * less efficient code.
+ */
+# if defined(__clang__) && defined(__has_attribute)
+ /* Clang defines both __clang__ and __GNUC__. Check __clang__ first. */
+# if !defined(PNG_USE_RESULT) && __has_attribute(__warn_unused_result__)
+# define PNG_USE_RESULT __attribute__((__warn_unused_result__))
+# endif
+# if !defined(PNG_NORETURN) && __has_attribute(__noreturn__)
+# define PNG_NORETURN __attribute__((__noreturn__))
+# endif
+# if !defined(PNG_ALLOCATED) && __has_attribute(__malloc__)
+# define PNG_ALLOCATED __attribute__((__malloc__))
+# endif
+# if !defined(PNG_DEPRECATED) && __has_attribute(__deprecated__)
+# define PNG_DEPRECATED __attribute__((__deprecated__))
+# endif
+# if !defined(PNG_PRIVATE)
+# ifdef __has_extension
+# if __has_extension(attribute_unavailable_with_message)
+# define PNG_PRIVATE __attribute__((__unavailable__(\
+ "This function is not exported by libpng.")))
+# endif
+# endif
+# endif
+# ifndef PNG_RESTRICT
+# define PNG_RESTRICT __restrict
+# endif
+
+# elif defined(__GNUC__)
+# ifndef PNG_USE_RESULT
+# define PNG_USE_RESULT __attribute__((__warn_unused_result__))
+# endif
+# ifndef PNG_NORETURN
+# define PNG_NORETURN __attribute__((__noreturn__))
+# endif
+# if __GNUC__ >= 3
+# ifndef PNG_ALLOCATED
+# define PNG_ALLOCATED __attribute__((__malloc__))
+# endif
+# ifndef PNG_DEPRECATED
+# define PNG_DEPRECATED __attribute__((__deprecated__))
+# endif
+# ifndef PNG_PRIVATE
+# if 0 /* Doesn't work so we use deprecated instead*/
+# define PNG_PRIVATE \
+ __attribute__((warning("This function is not exported by libpng.")))
+# else
+# define PNG_PRIVATE \
+ __attribute__((__deprecated__))
+# endif
+# endif
+# if ((__GNUC__ > 3) || !defined(__GNUC_MINOR__) || (__GNUC_MINOR__ >= 1))
+# ifndef PNG_RESTRICT
+# define PNG_RESTRICT __restrict
+# endif
+# endif /* __GNUC__.__GNUC_MINOR__ > 3.0 */
+# endif /* __GNUC__ >= 3 */
+
+# elif defined(_MSC_VER) && (_MSC_VER >= 1300)
+# ifndef PNG_USE_RESULT
+# define PNG_USE_RESULT /* not supported */
+# endif
+# ifndef PNG_NORETURN
+# define PNG_NORETURN __declspec(noreturn)
+# endif
+# ifndef PNG_ALLOCATED
+# if (_MSC_VER >= 1400)
+# define PNG_ALLOCATED __declspec(restrict)
+# endif
+# endif
+# ifndef PNG_DEPRECATED
+# define PNG_DEPRECATED __declspec(deprecated)
+# endif
+# ifndef PNG_PRIVATE
+# define PNG_PRIVATE __declspec(deprecated)
+# endif
+# ifndef PNG_RESTRICT
+# if (_MSC_VER >= 1400)
+# define PNG_RESTRICT __restrict
+# endif
+# endif
+
+# elif defined(__WATCOMC__)
+# ifndef PNG_RESTRICT
+# define PNG_RESTRICT __restrict
+# endif
+# endif
+#endif /* PNG_PEDANTIC_WARNINGS */
+
+#ifndef PNG_DEPRECATED
+# define PNG_DEPRECATED /* Use of this function is deprecated */
+#endif
+#ifndef PNG_USE_RESULT
+# define PNG_USE_RESULT /* The result of this function must be checked */
+#endif
+#ifndef PNG_NORETURN
+# define PNG_NORETURN /* This function does not return */
+#endif
+#ifndef PNG_ALLOCATED
+# define PNG_ALLOCATED /* The result of the function is new memory */
+#endif
+#ifndef PNG_PRIVATE
+# define PNG_PRIVATE /* This is a private libpng function */
+#endif
+#ifndef PNG_RESTRICT
+# define PNG_RESTRICT /* The C99 "restrict" feature */
+#endif
+
+#ifndef PNG_FP_EXPORT /* A floating point API. */
+# ifdef PNG_FLOATING_POINT_SUPPORTED
+# define PNG_FP_EXPORT(ordinal, type, name, args)\
+ PNG_EXPORT(ordinal, type, name, args);
+# else /* No floating point APIs */
+# define PNG_FP_EXPORT(ordinal, type, name, args)
+# endif
+#endif
+#ifndef PNG_FIXED_EXPORT /* A fixed point API. */
+# ifdef PNG_FIXED_POINT_SUPPORTED
+# define PNG_FIXED_EXPORT(ordinal, type, name, args)\
+ PNG_EXPORT(ordinal, type, name, args);
+# else /* No fixed point APIs */
+# define PNG_FIXED_EXPORT(ordinal, type, name, args)
+# endif
+#endif
+
+#ifndef PNG_BUILDING_SYMBOL_TABLE
+/* Some typedefs to get us started. These should be safe on most of the common
+ * platforms.
+ *
+ * png_uint_32 and png_int_32 may, currently, be larger than required to hold a
+ * 32-bit value however this is not normally advisable.
+ *
+ * png_uint_16 and png_int_16 should always be two bytes in size - this is
+ * verified at library build time.
+ *
+ * png_byte must always be one byte in size.
+ *
+ * The checks below use constants from limits.h, as defined by the ISOC90
+ * standard.
+ */
+#if CHAR_BIT == 8 && UCHAR_MAX == 255
+ typedef unsigned char png_byte;
+#else
+# error "libpng requires 8-bit bytes"
+#endif
+
+#if INT_MIN == -32768 && INT_MAX == 32767
+ typedef int png_int_16;
+#elif SHRT_MIN == -32768 && SHRT_MAX == 32767
+ typedef short png_int_16;
+#else
+# error "libpng requires a signed 16-bit type"
+#endif
+
+#if UINT_MAX == 65535
+ typedef unsigned int png_uint_16;
+#elif USHRT_MAX == 65535
+ typedef unsigned short png_uint_16;
+#else
+# error "libpng requires an unsigned 16-bit type"
+#endif
+
+#if INT_MIN < -2147483646 && INT_MAX > 2147483646
+ typedef int png_int_32;
+#elif LONG_MIN < -2147483646 && LONG_MAX > 2147483646
+ typedef long int png_int_32;
+#else
+# error "libpng requires a signed 32-bit (or more) type"
+#endif
+
+#if UINT_MAX > 4294967294
+ typedef unsigned int png_uint_32;
+#elif ULONG_MAX > 4294967294
+ typedef unsigned long int png_uint_32;
+#else
+# error "libpng requires an unsigned 32-bit (or more) type"
+#endif
+
+/* Prior to 1.6.0 it was possible to disable the use of size_t, 1.6.0, however,
+ * requires an ISOC90 compiler and relies on consistent behavior of sizeof.
+ */
+typedef size_t png_size_t;
+typedef ptrdiff_t png_ptrdiff_t;
+
+/* libpng needs to know the maximum value of 'size_t' and this controls the
+ * definition of png_alloc_size_t, below. This maximum value of size_t limits
+ * but does not control the maximum allocations the library makes - there is
+ * direct application control of this through png_set_user_limits().
+ */
+#ifndef PNG_SMALL_SIZE_T
+ /* Compiler specific tests for systems where size_t is known to be less than
+ * 32 bits (some of these systems may no longer work because of the lack of
+ * 'far' support; see above.)
+ */
+# if (defined(__TURBOC__) && !defined(__FLAT__)) ||\
+ (defined(_MSC_VER) && defined(MAXSEG_64K))
+# define PNG_SMALL_SIZE_T
+# endif
+#endif
+
+/* png_alloc_size_t is guaranteed to be no smaller than png_size_t, and no
+ * smaller than png_uint_32. Casts from png_size_t or png_uint_32 to
+ * png_alloc_size_t are not necessary; in fact, it is recommended not to use
+ * them at all so that the compiler can complain when something turns out to be
+ * problematic.
+ *
+ * Casts in the other direction (from png_alloc_size_t to png_size_t or
+ * png_uint_32) should be explicitly applied; however, we do not expect to
+ * encounter practical situations that require such conversions.
+ *
+ * PNG_SMALL_SIZE_T must be defined if the maximum value of size_t is less than
+ * 4294967295 - i.e. less than the maximum value of png_uint_32.
+ */
+#ifdef PNG_SMALL_SIZE_T
+ typedef png_uint_32 png_alloc_size_t;
+#else
+ typedef png_size_t png_alloc_size_t;
+#endif
+
+/* Prior to 1.6.0 libpng offered limited support for Microsoft C compiler
+ * implementations of Intel CPU specific support of user-mode segmented address
+ * spaces, where 16-bit pointers address more than 65536 bytes of memory using
+ * separate 'segment' registers. The implementation requires two different
+ * types of pointer (only one of which includes the segment value.)
+ *
+ * If required this support is available in version 1.2 of libpng and may be
+ * available in versions through 1.5, although the correctness of the code has
+ * not been verified recently.
+ */
+
+/* Typedef for floating-point numbers that are converted to fixed-point with a
+ * multiple of 100,000, e.g., gamma
+ */
+typedef png_int_32 png_fixed_point;
+
+/* Add typedefs for pointers */
+typedef void * png_voidp;
+typedef const void * png_const_voidp;
+typedef png_byte * png_bytep;
+typedef const png_byte * png_const_bytep;
+typedef png_uint_32 * png_uint_32p;
+typedef const png_uint_32 * png_const_uint_32p;
+typedef png_int_32 * png_int_32p;
+typedef const png_int_32 * png_const_int_32p;
+typedef png_uint_16 * png_uint_16p;
+typedef const png_uint_16 * png_const_uint_16p;
+typedef png_int_16 * png_int_16p;
+typedef const png_int_16 * png_const_int_16p;
+typedef char * png_charp;
+typedef const char * png_const_charp;
+typedef png_fixed_point * png_fixed_point_p;
+typedef const png_fixed_point * png_const_fixed_point_p;
+typedef png_size_t * png_size_tp;
+typedef const png_size_t * png_const_size_tp;
+
+#ifdef PNG_STDIO_SUPPORTED
+typedef FILE * png_FILE_p;
+#endif
+
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+typedef double * png_doublep;
+typedef const double * png_const_doublep;
+#endif
+
+/* Pointers to pointers; i.e. arrays */
+typedef png_byte * * png_bytepp;
+typedef png_uint_32 * * png_uint_32pp;
+typedef png_int_32 * * png_int_32pp;
+typedef png_uint_16 * * png_uint_16pp;
+typedef png_int_16 * * png_int_16pp;
+typedef const char * * png_const_charpp;
+typedef char * * png_charpp;
+typedef png_fixed_point * * png_fixed_point_pp;
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+typedef double * * png_doublepp;
+#endif
+
+/* Pointers to pointers to pointers; i.e., pointer to array */
+typedef char * * * png_charppp;
+
+#endif /* PNG_BUILDING_SYMBOL_TABLE */
+
+#endif /* PNGCONF_H */
diff --git a/third_party/lpng_v163/pngdebug.h b/third_party/libpng/pngdebug.h
similarity index 86%
rename from third_party/lpng_v163/pngdebug.h
rename to third_party/libpng/pngdebug.h
index 96c1ea4..6a01b10 100644
--- a/third_party/lpng_v163/pngdebug.h
+++ b/third_party/libpng/pngdebug.h
@@ -1,157 +1,153 @@
-
-/* pngdebug.h - Debugging macros for libpng, also used in pngtest.c
- *
- * Copyright (c) 1998-2011 Glenn Randers-Pehrson
- * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
- * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
- *
- * Last changed in libpng 1.5.0 [January 6, 2011]
- *
- * This code is released under the libpng license.
- * For conditions of distribution and use, see the disclaimer
- * and license in png.h
- */
-
-/* Define PNG_DEBUG at compile time for debugging information. Higher
- * numbers for PNG_DEBUG mean more debugging information. This has
- * only been added since version 0.95 so it is not implemented throughout
- * libpng yet, but more support will be added as needed.
- *
- * png_debug[1-2]?(level, message ,arg{0-2})
- * Expands to a statement (either a simple expression or a compound
- * do..while(0) statement) that outputs a message with parameter
- * substitution if PNG_DEBUG is defined to 2 or more. If PNG_DEBUG
- * is undefined, 0 or 1 every png_debug expands to a simple expression
- * (actually ((void)0)).
- *
- * level: level of detail of message, starting at 0. A level 'n'
- * message is preceded by 'n' tab characters (not implemented
- * on Microsoft compilers unless PNG_DEBUG_FILE is also
- * defined, to allow debug DLL compilation with no standard IO).
- * message: a printf(3) style text string. A trailing '\n' is added
- * to the message.
- * arg: 0 to 2 arguments for printf(3) style substitution in message.
- */
-#ifndef PNGDEBUG_H
-#define PNGDEBUG_H
-/* These settings control the formatting of messages in png.c and pngerror.c */
-/* Moved to pngdebug.h at 1.5.0 */
-# ifndef PNG_LITERAL_SHARP
-# define PNG_LITERAL_SHARP 0x23
-# endif
-# ifndef PNG_LITERAL_LEFT_SQUARE_BRACKET
-# define PNG_LITERAL_LEFT_SQUARE_BRACKET 0x5b
-# endif
-# ifndef PNG_LITERAL_RIGHT_SQUARE_BRACKET
-# define PNG_LITERAL_RIGHT_SQUARE_BRACKET 0x5d
-# endif
-# ifndef PNG_STRING_NEWLINE
-# define PNG_STRING_NEWLINE "\n"
-# endif
-
-#ifdef PNG_DEBUG
-# if (PNG_DEBUG > 0)
-# if !defined(PNG_DEBUG_FILE) && defined(_MSC_VER)
-# include <crtdbg.h>
-# if (PNG_DEBUG > 1)
-# ifndef _DEBUG
-# define _DEBUG
-# endif
-# ifndef png_debug
-# define png_debug(l,m) _RPT0(_CRT_WARN,m PNG_STRING_NEWLINE)
-# endif
-# ifndef png_debug1
-# define png_debug1(l,m,p1) _RPT1(_CRT_WARN,m PNG_STRING_NEWLINE,p1)
-# endif
-# ifndef png_debug2
-# define png_debug2(l,m,p1,p2) \
- _RPT2(_CRT_WARN,m PNG_STRING_NEWLINE,p1,p2)
-# endif
-# endif
-# else /* PNG_DEBUG_FILE || !_MSC_VER */
-# ifndef PNG_STDIO_SUPPORTED
-# include <stdio.h> /* not included yet */
-# endif
-# ifndef PNG_DEBUG_FILE
-# define PNG_DEBUG_FILE stderr
-# endif /* PNG_DEBUG_FILE */
-
-# if (PNG_DEBUG > 1)
-/* Note: ["%s"m PNG_STRING_NEWLINE] probably does not work on
- * non-ISO compilers
- */
-# ifdef __STDC__
-# ifndef png_debug
-# define png_debug(l,m) \
- do { \
- int num_tabs=l; \
- fprintf(PNG_DEBUG_FILE,"%s"m PNG_STRING_NEWLINE,(num_tabs==1 ? "\t" : \
- (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":"")))); \
- } while (0)
-# endif
-# ifndef png_debug1
-# define png_debug1(l,m,p1) \
- do { \
- int num_tabs=l; \
- fprintf(PNG_DEBUG_FILE,"%s"m PNG_STRING_NEWLINE,(num_tabs==1 ? "\t" : \
- (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))),p1); \
- } while (0)
-# endif
-# ifndef png_debug2
-# define png_debug2(l,m,p1,p2) \
- do { \
- int num_tabs=l; \
- fprintf(PNG_DEBUG_FILE,"%s"m PNG_STRING_NEWLINE,(num_tabs==1 ? "\t" : \
- (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))),p1,p2); \
- } while (0)
-# endif
-# else /* __STDC __ */
-# ifndef png_debug
-# define png_debug(l,m) \
- do { \
- int num_tabs=l; \
- char format[256]; \
- snprintf(format,256,"%s%s%s",(num_tabs==1 ? "\t" : \
- (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))), \
- m,PNG_STRING_NEWLINE); \
- fprintf(PNG_DEBUG_FILE,format); \
- } while (0)
-# endif
-# ifndef png_debug1
-# define png_debug1(l,m,p1) \
- do { \
- int num_tabs=l; \
- char format[256]; \
- snprintf(format,256,"%s%s%s",(num_tabs==1 ? "\t" : \
- (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))), \
- m,PNG_STRING_NEWLINE); \
- fprintf(PNG_DEBUG_FILE,format,p1); \
- } while (0)
-# endif
-# ifndef png_debug2
-# define png_debug2(l,m,p1,p2) \
- do { \
- int num_tabs=l; \
- char format[256]; \
- snprintf(format,256,"%s%s%s",(num_tabs==1 ? "\t" : \
- (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))), \
- m,PNG_STRING_NEWLINE); \
- fprintf(PNG_DEBUG_FILE,format,p1,p2); \
- } while (0)
-# endif
-# endif /* __STDC __ */
-# endif /* (PNG_DEBUG > 1) */
-
-# endif /* _MSC_VER */
-# endif /* (PNG_DEBUG > 0) */
-#endif /* PNG_DEBUG */
-#ifndef png_debug
-# define png_debug(l, m) ((void)0)
-#endif
-#ifndef png_debug1
-# define png_debug1(l, m, p1) ((void)0)
-#endif
-#ifndef png_debug2
-# define png_debug2(l, m, p1, p2) ((void)0)
-#endif
-#endif /* PNGDEBUG_H */
+
+/* pngdebug.h - Debugging macros for libpng, also used in pngtest.c
+ *
+ * Last changed in libpng 1.6.8 [December 19, 2013]
+ * Copyright (c) 1998-2013 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+
+/* Define PNG_DEBUG at compile time for debugging information. Higher
+ * numbers for PNG_DEBUG mean more debugging information. This has
+ * only been added since version 0.95 so it is not implemented throughout
+ * libpng yet, but more support will be added as needed.
+ *
+ * png_debug[1-2]?(level, message ,arg{0-2})
+ * Expands to a statement (either a simple expression or a compound
+ * do..while(0) statement) that outputs a message with parameter
+ * substitution if PNG_DEBUG is defined to 2 or more. If PNG_DEBUG
+ * is undefined, 0 or 1 every png_debug expands to a simple expression
+ * (actually ((void)0)).
+ *
+ * level: level of detail of message, starting at 0. A level 'n'
+ * message is preceded by 'n' 3-space indentations (not implemented
+ * on Microsoft compilers unless PNG_DEBUG_FILE is also
+ * defined, to allow debug DLL compilation with no standard IO).
+ * message: a printf(3) style text string. A trailing '\n' is added
+ * to the message.
+ * arg: 0 to 2 arguments for printf(3) style substitution in message.
+ */
+#ifndef PNGDEBUG_H
+#define PNGDEBUG_H
+/* These settings control the formatting of messages in png.c and pngerror.c */
+/* Moved to pngdebug.h at 1.5.0 */
+# ifndef PNG_LITERAL_SHARP
+# define PNG_LITERAL_SHARP 0x23
+# endif
+# ifndef PNG_LITERAL_LEFT_SQUARE_BRACKET
+# define PNG_LITERAL_LEFT_SQUARE_BRACKET 0x5b
+# endif
+# ifndef PNG_LITERAL_RIGHT_SQUARE_BRACKET
+# define PNG_LITERAL_RIGHT_SQUARE_BRACKET 0x5d
+# endif
+# ifndef PNG_STRING_NEWLINE
+# define PNG_STRING_NEWLINE "\n"
+# endif
+
+#ifdef PNG_DEBUG
+# if (PNG_DEBUG > 0)
+# if !defined(PNG_DEBUG_FILE) && defined(_MSC_VER)
+# include <crtdbg.h>
+# if (PNG_DEBUG > 1)
+# ifndef _DEBUG
+# define _DEBUG
+# endif
+# ifndef png_debug
+# define png_debug(l,m) _RPT0(_CRT_WARN,m PNG_STRING_NEWLINE)
+# endif
+# ifndef png_debug1
+# define png_debug1(l,m,p1) _RPT1(_CRT_WARN,m PNG_STRING_NEWLINE,p1)
+# endif
+# ifndef png_debug2
+# define png_debug2(l,m,p1,p2) \
+ _RPT2(_CRT_WARN,m PNG_STRING_NEWLINE,p1,p2)
+# endif
+# endif
+# else /* PNG_DEBUG_FILE || !_MSC_VER */
+# ifndef PNG_STDIO_SUPPORTED
+# include <stdio.h> /* not included yet */
+# endif
+# ifndef PNG_DEBUG_FILE
+# define PNG_DEBUG_FILE stderr
+# endif /* PNG_DEBUG_FILE */
+
+# if (PNG_DEBUG > 1)
+# ifdef __STDC__
+# ifndef png_debug
+# define png_debug(l,m) \
+ do { \
+ int num_tabs=l; \
+ fprintf(PNG_DEBUG_FILE,"%s" m PNG_STRING_NEWLINE,(num_tabs==1 ? " " : \
+ (num_tabs==2 ? " " : (num_tabs>2 ? " " : "")))); \
+ } while (0)
+# endif
+# ifndef png_debug1
+# define png_debug1(l,m,p1) \
+ do { \
+ int num_tabs=l; \
+ fprintf(PNG_DEBUG_FILE,"%s" m PNG_STRING_NEWLINE,(num_tabs==1 ? " " : \
+ (num_tabs==2 ? " " : (num_tabs>2 ? " " : ""))),p1); \
+ } while (0)
+# endif
+# ifndef png_debug2
+# define png_debug2(l,m,p1,p2) \
+ do { \
+ int num_tabs=l; \
+ fprintf(PNG_DEBUG_FILE,"%s" m PNG_STRING_NEWLINE,(num_tabs==1 ? " " : \
+ (num_tabs==2 ? " " : (num_tabs>2 ? " " : ""))),p1,p2);\
+ } while (0)
+# endif
+# else /* __STDC __ */
+# ifndef png_debug
+# define png_debug(l,m) \
+ do { \
+ int num_tabs=l; \
+ char format[256]; \
+ snprintf(format,256,"%s%s%s",(num_tabs==1 ? "\t" : \
+ (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))), \
+ m,PNG_STRING_NEWLINE); \
+ fprintf(PNG_DEBUG_FILE,format); \
+ } while (0)
+# endif
+# ifndef png_debug1
+# define png_debug1(l,m,p1) \
+ do { \
+ int num_tabs=l; \
+ char format[256]; \
+ snprintf(format,256,"%s%s%s",(num_tabs==1 ? "\t" : \
+ (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))), \
+ m,PNG_STRING_NEWLINE); \
+ fprintf(PNG_DEBUG_FILE,format,p1); \
+ } while (0)
+# endif
+# ifndef png_debug2
+# define png_debug2(l,m,p1,p2) \
+ do { \
+ int num_tabs=l; \
+ char format[256]; \
+ snprintf(format,256,"%s%s%s",(num_tabs==1 ? "\t" : \
+ (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))), \
+ m,PNG_STRING_NEWLINE); \
+ fprintf(PNG_DEBUG_FILE,format,p1,p2); \
+ } while (0)
+# endif
+# endif /* __STDC __ */
+# endif /* (PNG_DEBUG > 1) */
+
+# endif /* _MSC_VER */
+# endif /* (PNG_DEBUG > 0) */
+#endif /* PNG_DEBUG */
+#ifndef png_debug
+# define png_debug(l, m) ((void)0)
+#endif
+#ifndef png_debug1
+# define png_debug1(l, m, p1) ((void)0)
+#endif
+#ifndef png_debug2
+# define png_debug2(l, m, p1, p2) ((void)0)
+#endif
+#endif /* PNGDEBUG_H */
diff --git a/third_party/lpng_v163/pngerror.c b/third_party/libpng/pngerror.c
similarity index 90%
rename from third_party/lpng_v163/pngerror.c
rename to third_party/libpng/pngerror.c
index 2125e4c..bdb959e 100644
--- a/third_party/lpng_v163/pngerror.c
+++ b/third_party/libpng/pngerror.c
@@ -1,931 +1,963 @@
-/* pngerror.c - stub functions for i/o and memory allocation
- *
- * Last changed in libpng 1.6.1 [March 28, 2013]
- * Copyright (c) 1998-2013 Glenn Randers-Pehrson
- * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
- * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
- *
- * This code is released under the libpng license.
- * For conditions of distribution and use, see the disclaimer
- * and license in png.h
- *
- * This file provides a location for all error handling. Users who
- * need special error handling are expected to write replacement functions
- * and use png_set_error_fn() to use those functions. See the instructions
- * at each function.
- */
-
-#include "pngpriv.h"
-
-#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
-
-static PNG_FUNCTION(void, png_default_error,PNGARG((png_const_structrp png_ptr,
- png_const_charp error_message)),PNG_NORETURN);
-
-#ifdef PNG_WARNINGS_SUPPORTED
-static void /* PRIVATE */
-png_default_warning PNGARG((png_const_structrp png_ptr,
- png_const_charp warning_message));
-#endif /* PNG_WARNINGS_SUPPORTED */
-
-/* This function is called whenever there is a fatal error. This function
- * should not be changed. If there is a need to handle errors differently,
- * you should supply a replacement error function and use png_set_error_fn()
- * to replace the error function at run-time.
- */
-#ifdef PNG_ERROR_TEXT_SUPPORTED
-PNG_FUNCTION(void,PNGAPI
-png_error,(png_const_structrp png_ptr, png_const_charp error_message),
- PNG_NORETURN)
-{
-#ifdef PNG_ERROR_NUMBERS_SUPPORTED
- char msg[16];
- if (png_ptr != NULL)
- {
- if (png_ptr->flags&
- (PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT))
- {
- if (*error_message == PNG_LITERAL_SHARP)
- {
- /* Strip "#nnnn " from beginning of error message. */
- int offset;
- for (offset = 1; offset<15; offset++)
- if (error_message[offset] == ' ')
- break;
-
- if (png_ptr->flags&PNG_FLAG_STRIP_ERROR_TEXT)
- {
- int i;
- for (i = 0; i < offset - 1; i++)
- msg[i] = error_message[i + 1];
- msg[i - 1] = '\0';
- error_message = msg;
- }
-
- else
- error_message += offset;
- }
-
- else
- {
- if (png_ptr->flags&PNG_FLAG_STRIP_ERROR_TEXT)
- {
- msg[0] = '0';
- msg[1] = '\0';
- error_message = msg;
- }
- }
- }
- }
-#endif
- if (png_ptr != NULL && png_ptr->error_fn != NULL)
- (*(png_ptr->error_fn))(png_constcast(png_structrp,png_ptr),
- error_message);
-
- /* If the custom handler doesn't exist, or if it returns,
- use the default handler, which will not return. */
- png_default_error(png_ptr, error_message);
-}
-#else
-PNG_FUNCTION(void,PNGAPI
-png_err,(png_const_structrp png_ptr),PNG_NORETURN)
-{
- /* Prior to 1.5.2 the error_fn received a NULL pointer, expressed
- * erroneously as '\0', instead of the empty string "". This was
- * apparently an error, introduced in libpng-1.2.20, and png_default_error
- * will crash in this case.
- */
- if (png_ptr != NULL && png_ptr->error_fn != NULL)
- (*(png_ptr->error_fn))(png_constcast(png_structrp,png_ptr), "");
-
- /* If the custom handler doesn't exist, or if it returns,
- use the default handler, which will not return. */
- png_default_error(png_ptr, "");
-}
-#endif /* PNG_ERROR_TEXT_SUPPORTED */
-
-/* Utility to safely appends strings to a buffer. This never errors out so
- * error checking is not required in the caller.
- */
-size_t
-png_safecat(png_charp buffer, size_t bufsize, size_t pos,
- png_const_charp string)
-{
- if (buffer != NULL && pos < bufsize)
- {
- if (string != NULL)
- while (*string != '\0' && pos < bufsize-1)
- buffer[pos++] = *string++;
-
- buffer[pos] = '\0';
- }
-
- return pos;
-}
-
-#if defined(PNG_WARNINGS_SUPPORTED) || defined(PNG_TIME_RFC1123_SUPPORTED)
-/* Utility to dump an unsigned value into a buffer, given a start pointer and
- * and end pointer (which should point just *beyond* the end of the buffer!)
- * Returns the pointer to the start of the formatted string.
- */
-png_charp
-png_format_number(png_const_charp start, png_charp end, int format,
- png_alloc_size_t number)
-{
- int count = 0; /* number of digits output */
- int mincount = 1; /* minimum number required */
- int output = 0; /* digit output (for the fixed point format) */
-
- *--end = '\0';
-
- /* This is written so that the loop always runs at least once, even with
- * number zero.
- */
- while (end > start && (number != 0 || count < mincount))
- {
-
- static const char digits[] = "0123456789ABCDEF";
-
- switch (format)
- {
- case PNG_NUMBER_FORMAT_fixed:
- /* Needs five digits (the fraction) */
- mincount = 5;
- if (output || number % 10 != 0)
- {
- *--end = digits[number % 10];
- output = 1;
- }
- number /= 10;
- break;
-
- case PNG_NUMBER_FORMAT_02u:
- /* Expects at least 2 digits. */
- mincount = 2;
- /* FALL THROUGH */
-
- case PNG_NUMBER_FORMAT_u:
- *--end = digits[number % 10];
- number /= 10;
- break;
-
- case PNG_NUMBER_FORMAT_02x:
- /* This format expects at least two digits */
- mincount = 2;
- /* FALL THROUGH */
-
- case PNG_NUMBER_FORMAT_x:
- *--end = digits[number & 0xf];
- number >>= 4;
- break;
-
- default: /* an error */
- number = 0;
- break;
- }
-
- /* Keep track of the number of digits added */
- ++count;
-
- /* Float a fixed number here: */
- if (format == PNG_NUMBER_FORMAT_fixed) if (count == 5) if (end > start)
- {
- /* End of the fraction, but maybe nothing was output? In that case
- * drop the decimal point. If the number is a true zero handle that
- * here.
- */
- if (output)
- *--end = '.';
- else if (number == 0) /* and !output */
- *--end = '0';
- }
- }
-
- return end;
-}
-#endif
-
-#ifdef PNG_WARNINGS_SUPPORTED
-/* This function is called whenever there is a non-fatal error. This function
- * should not be changed. If there is a need to handle warnings differently,
- * you should supply a replacement warning function and use
- * png_set_error_fn() to replace the warning function at run-time.
- */
-void PNGAPI
-png_warning(png_const_structrp png_ptr, png_const_charp warning_message)
-{
- int offset = 0;
- if (png_ptr != NULL)
- {
-#ifdef PNG_ERROR_NUMBERS_SUPPORTED
- if (png_ptr->flags&
- (PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT))
-#endif
- {
- if (*warning_message == PNG_LITERAL_SHARP)
- {
- for (offset = 1; offset < 15; offset++)
- if (warning_message[offset] == ' ')
- break;
- }
- }
- }
- if (png_ptr != NULL && png_ptr->warning_fn != NULL)
- (*(png_ptr->warning_fn))(png_constcast(png_structrp,png_ptr),
- warning_message + offset);
- else
- png_default_warning(png_ptr, warning_message + offset);
-}
-
-/* These functions support 'formatted' warning messages with up to
- * PNG_WARNING_PARAMETER_COUNT parameters. In the format string the parameter
- * is introduced by @<number>, where 'number' starts at 1. This follows the
- * standard established by X/Open for internationalizable error messages.
- */
-void
-png_warning_parameter(png_warning_parameters p, int number,
- png_const_charp string)
-{
- if (number > 0 && number <= PNG_WARNING_PARAMETER_COUNT)
- (void)png_safecat(p[number-1], (sizeof p[number-1]), 0, string);
-}
-
-void
-png_warning_parameter_unsigned(png_warning_parameters p, int number, int format,
- png_alloc_size_t value)
-{
- char buffer[PNG_NUMBER_BUFFER_SIZE];
- png_warning_parameter(p, number, PNG_FORMAT_NUMBER(buffer, format, value));
-}
-
-void
-png_warning_parameter_signed(png_warning_parameters p, int number, int format,
- png_int_32 value)
-{
- png_alloc_size_t u;
- png_charp str;
- char buffer[PNG_NUMBER_BUFFER_SIZE];
-
- /* Avoid overflow by doing the negate in a png_alloc_size_t: */
- u = (png_alloc_size_t)value;
- if (value < 0)
- u = ~u + 1;
-
- str = PNG_FORMAT_NUMBER(buffer, format, u);
-
- if (value < 0 && str > buffer)
- *--str = '-';
-
- png_warning_parameter(p, number, str);
-}
-
-void
-png_formatted_warning(png_const_structrp png_ptr, png_warning_parameters p,
- png_const_charp message)
-{
- /* The internal buffer is just 192 bytes - enough for all our messages,
- * overflow doesn't happen because this code checks! If someone figures
- * out how to send us a message longer than 192 bytes, all that will
- * happen is that the message will be truncated appropriately.
- */
- size_t i = 0; /* Index in the msg[] buffer: */
- char msg[192];
-
- /* Each iteration through the following loop writes at most one character
- * to msg[i++] then returns here to validate that there is still space for
- * the trailing '\0'. It may (in the case of a parameter) read more than
- * one character from message[]; it must check for '\0' and continue to the
- * test if it finds the end of string.
- */
- while (i<(sizeof msg)-1 && *message != '\0')
- {
- /* '@' at end of string is now just printed (previously it was skipped);
- * it is an error in the calling code to terminate the string with @.
- */
- if (p != NULL && *message == '@' && message[1] != '\0')
- {
- int parameter_char = *++message; /* Consume the '@' */
- static const char valid_parameters[] = "123456789";
- int parameter = 0;
-
- /* Search for the parameter digit, the index in the string is the
- * parameter to use.
- */
- while (valid_parameters[parameter] != parameter_char &&
- valid_parameters[parameter] != '\0')
- ++parameter;
-
- /* If the parameter digit is out of range it will just get printed. */
- if (parameter < PNG_WARNING_PARAMETER_COUNT)
- {
- /* Append this parameter */
- png_const_charp parm = p[parameter];
- png_const_charp pend = p[parameter] + (sizeof p[parameter]);
-
- /* No need to copy the trailing '\0' here, but there is no guarantee
- * that parm[] has been initialized, so there is no guarantee of a
- * trailing '\0':
- */
- while (i<(sizeof msg)-1 && *parm != '\0' && parm < pend)
- msg[i++] = *parm++;
-
- /* Consume the parameter digit too: */
- ++message;
- continue;
- }
-
- /* else not a parameter and there is a character after the @ sign; just
- * copy that. This is known not to be '\0' because of the test above.
- */
- }
-
- /* At this point *message can't be '\0', even in the bad parameter case
- * above where there is a lone '@' at the end of the message string.
- */
- msg[i++] = *message++;
- }
-
- /* i is always less than (sizeof msg), so: */
- msg[i] = '\0';
-
- /* And this is the formatted message. It may be larger than
- * PNG_MAX_ERROR_TEXT, but that is only used for 'chunk' errors and these
- * are not (currently) formatted.
- */
- png_warning(png_ptr, msg);
-}
-#endif /* PNG_WARNINGS_SUPPORTED */
-
-#ifdef PNG_BENIGN_ERRORS_SUPPORTED
-void PNGAPI
-png_benign_error(png_const_structrp png_ptr, png_const_charp error_message)
-{
- if (png_ptr->flags & PNG_FLAG_BENIGN_ERRORS_WARN)
- {
-# ifdef PNG_READ_SUPPORTED
- if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0 &&
- png_ptr->chunk_name != 0)
- png_chunk_warning(png_ptr, error_message);
- else
-# endif
- png_warning(png_ptr, error_message);
- }
-
- else
- {
-# ifdef PNG_READ_SUPPORTED
- if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0 &&
- png_ptr->chunk_name != 0)
- png_chunk_error(png_ptr, error_message);
- else
-# endif
- png_error(png_ptr, error_message);
- }
-}
-
-void /* PRIVATE */
-png_app_warning(png_const_structrp png_ptr, png_const_charp error_message)
-{
- if (png_ptr->flags & PNG_FLAG_APP_WARNINGS_WARN)
- png_warning(png_ptr, error_message);
- else
- png_error(png_ptr, error_message);
-}
-
-void /* PRIVATE */
-png_app_error(png_const_structrp png_ptr, png_const_charp error_message)
-{
- if (png_ptr->flags & PNG_FLAG_APP_ERRORS_WARN)
- png_warning(png_ptr, error_message);
- else
- png_error(png_ptr, error_message);
-}
-#endif /* BENIGN_ERRORS */
-
-/* These utilities are used internally to build an error message that relates
- * to the current chunk. The chunk name comes from png_ptr->chunk_name,
- * this is used to prefix the message. The message is limited in length
- * to 63 bytes, the name characters are output as hex digits wrapped in []
- * if the character is invalid.
- */
-#define isnonalpha(c) ((c) < 65 || (c) > 122 || ((c) > 90 && (c) < 97))
-static PNG_CONST char png_digit[16] = {
- '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
- 'A', 'B', 'C', 'D', 'E', 'F'
-};
-
-#define PNG_MAX_ERROR_TEXT 196 /* Currently limited be profile_error in png.c */
-#if defined(PNG_WARNINGS_SUPPORTED) || defined(PNG_ERROR_TEXT_SUPPORTED)
-static void /* PRIVATE */
-png_format_buffer(png_const_structrp png_ptr, png_charp buffer, png_const_charp
- error_message)
-{
- png_uint_32 chunk_name = png_ptr->chunk_name;
- int iout = 0, ishift = 24;
-
- while (ishift >= 0)
- {
- int c = (int)(chunk_name >> ishift) & 0xff;
-
- ishift -= 8;
- if (isnonalpha(c))
- {
- buffer[iout++] = PNG_LITERAL_LEFT_SQUARE_BRACKET;
- buffer[iout++] = png_digit[(c & 0xf0) >> 4];
- buffer[iout++] = png_digit[c & 0x0f];
- buffer[iout++] = PNG_LITERAL_RIGHT_SQUARE_BRACKET;
- }
-
- else
- {
- buffer[iout++] = (char)c;
- }
- }
-
- if (error_message == NULL)
- buffer[iout] = '\0';
-
- else
- {
- int iin = 0;
-
- buffer[iout++] = ':';
- buffer[iout++] = ' ';
-
- while (iin < PNG_MAX_ERROR_TEXT-1 && error_message[iin] != '\0')
- buffer[iout++] = error_message[iin++];
-
- /* iin < PNG_MAX_ERROR_TEXT, so the following is safe: */
- buffer[iout] = '\0';
- }
-}
-#endif /* PNG_WARNINGS_SUPPORTED || PNG_ERROR_TEXT_SUPPORTED */
-
-#if defined(PNG_READ_SUPPORTED) && defined(PNG_ERROR_TEXT_SUPPORTED)
-PNG_FUNCTION(void,PNGAPI
-png_chunk_error,(png_const_structrp png_ptr, png_const_charp error_message),
- PNG_NORETURN)
-{
- char msg[18+PNG_MAX_ERROR_TEXT];
- if (png_ptr == NULL)
- png_error(png_ptr, error_message);
-
- else
- {
- png_format_buffer(png_ptr, msg, error_message);
- png_error(png_ptr, msg);
- }
-}
-#endif /* PNG_READ_SUPPORTED && PNG_ERROR_TEXT_SUPPORTED */
-
-#ifdef PNG_WARNINGS_SUPPORTED
-void PNGAPI
-png_chunk_warning(png_const_structrp png_ptr, png_const_charp warning_message)
-{
- char msg[18+PNG_MAX_ERROR_TEXT];
- if (png_ptr == NULL)
- png_warning(png_ptr, warning_message);
-
- else
- {
- png_format_buffer(png_ptr, msg, warning_message);
- png_warning(png_ptr, msg);
- }
-}
-#endif /* PNG_WARNINGS_SUPPORTED */
-
-#ifdef PNG_READ_SUPPORTED
-#ifdef PNG_BENIGN_ERRORS_SUPPORTED
-void PNGAPI
-png_chunk_benign_error(png_const_structrp png_ptr, png_const_charp
- error_message)
-{
- if (png_ptr->flags & PNG_FLAG_BENIGN_ERRORS_WARN)
- png_chunk_warning(png_ptr, error_message);
-
- else
- png_chunk_error(png_ptr, error_message);
-}
-#endif
-#endif /* PNG_READ_SUPPORTED */
-
-void /* PRIVATE */
-png_chunk_report(png_const_structrp png_ptr, png_const_charp message, int error)
-{
- /* This is always supported, but for just read or just write it
- * unconditionally does the right thing.
- */
-# if defined(PNG_READ_SUPPORTED) && defined(PNG_WRITE_SUPPORTED)
- if (png_ptr->mode & PNG_IS_READ_STRUCT)
-# endif
-
-# ifdef PNG_READ_SUPPORTED
- {
- if (error < PNG_CHUNK_ERROR)
- png_chunk_warning(png_ptr, message);
-
- else
- png_chunk_benign_error(png_ptr, message);
- }
-# endif
-
-# if defined(PNG_READ_SUPPORTED) && defined(PNG_WRITE_SUPPORTED)
- else if (!(png_ptr->mode & PNG_IS_READ_STRUCT))
-# endif
-
-# ifdef PNG_WRITE_SUPPORTED
- {
- if (error < PNG_CHUNK_WRITE_ERROR)
- png_app_warning(png_ptr, message);
-
- else
- png_app_error(png_ptr, message);
- }
-# endif
-}
-
-#ifdef PNG_ERROR_TEXT_SUPPORTED
-#ifdef PNG_FLOATING_POINT_SUPPORTED
-PNG_FUNCTION(void,
-png_fixed_error,(png_const_structrp png_ptr, png_const_charp name),PNG_NORETURN)
-{
-# define fixed_message "fixed point overflow in "
-# define fixed_message_ln ((sizeof fixed_message)-1)
- int iin;
- char msg[fixed_message_ln+PNG_MAX_ERROR_TEXT];
- memcpy(msg, fixed_message, fixed_message_ln);
- iin = 0;
- if (name != NULL) while (iin < (PNG_MAX_ERROR_TEXT-1) && name[iin] != 0)
- {
- msg[fixed_message_ln + iin] = name[iin];
- ++iin;
- }
- msg[fixed_message_ln + iin] = 0;
- png_error(png_ptr, msg);
-}
-#endif
-#endif
-
-#ifdef PNG_SETJMP_SUPPORTED
-/* This API only exists if ANSI-C style error handling is used,
- * otherwise it is necessary for png_default_error to be overridden.
- */
-jmp_buf* PNGAPI
-png_set_longjmp_fn(png_structrp png_ptr, png_longjmp_ptr longjmp_fn,
- size_t jmp_buf_size)
-{
- /* From libpng 1.6.0 the app gets one chance to set a 'jmpbuf_size' value
- * and it must not change after that. Libpng doesn't care how big the
- * buffer is, just that it doesn't change.
- *
- * If the buffer size is no *larger* than the size of jmp_buf when libpng is
- * compiled a built in jmp_buf is returned; this preserves the pre-1.6.0
- * semantics that this call will not fail. If the size is larger, however,
- * the buffer is allocated and this may fail, causing the function to return
- * NULL.
- */
- if (png_ptr == NULL)
- return NULL;
-
- if (png_ptr->jmp_buf_ptr == NULL)
- {
- png_ptr->jmp_buf_size = 0; /* not allocated */
-
- if (jmp_buf_size <= (sizeof png_ptr->jmp_buf_local))
- png_ptr->jmp_buf_ptr = &png_ptr->jmp_buf_local;
-
- else
- {
- png_ptr->jmp_buf_ptr = png_voidcast(jmp_buf *,
- png_malloc_warn(png_ptr, jmp_buf_size));
-
- if (png_ptr->jmp_buf_ptr == NULL)
- return NULL; /* new NULL return on OOM */
-
- png_ptr->jmp_buf_size = jmp_buf_size;
- }
- }
-
- else /* Already allocated: check the size */
- {
- size_t size = png_ptr->jmp_buf_size;
-
- if (size == 0)
- {
- size = (sizeof png_ptr->jmp_buf_local);
- if (png_ptr->jmp_buf_ptr != &png_ptr->jmp_buf_local)
- {
- /* This is an internal error in libpng: somehow we have been left
- * with a stack allocated jmp_buf when the application regained
- * control. It's always possible to fix this up, but for the moment
- * this is a png_error because that makes it easy to detect.
- */
- png_error(png_ptr, "Libpng jmp_buf still allocated");
- /* png_ptr->jmp_buf_ptr = &png_ptr->jmp_buf_local; */
- }
- }
-
- if (size != jmp_buf_size)
- {
- png_warning(png_ptr, "Application jmp_buf size changed");
- return NULL; /* caller will probably crash: no choice here */
- }
- }
-
- /* Finally fill in the function, now we have a satisfactory buffer. It is
- * valid to change the function on every call.
- */
- png_ptr->longjmp_fn = longjmp_fn;
- return png_ptr->jmp_buf_ptr;
-}
-
-void /* PRIVATE */
-png_free_jmpbuf(png_structrp png_ptr)
-{
- if (png_ptr != NULL)
- {
- jmp_buf *jb = png_ptr->jmp_buf_ptr;
-
- /* A size of 0 is used to indicate a local, stack, allocation of the
- * pointer; used here and in png.c
- */
- if (jb != NULL && png_ptr->jmp_buf_size > 0)
- {
-
- /* This stuff is so that a failure to free the error control structure
- * does not leave libpng in a state with no valid error handling: the
- * free always succeeds, if there is an error it gets ignored.
- */
- if (jb != &png_ptr->jmp_buf_local)
- {
- /* Make an internal, libpng, jmp_buf to return here */
- jmp_buf free_jmp_buf;
-
- if (!setjmp(free_jmp_buf))
- {
- png_ptr->jmp_buf_ptr = &free_jmp_buf; /* come back here */
- png_ptr->jmp_buf_size = 0; /* stack allocation */
- png_ptr->longjmp_fn = longjmp;
- png_free(png_ptr, jb); /* Return to setjmp on error */
- }
- }
- }
-
- /* *Always* cancel everything out: */
- png_ptr->jmp_buf_size = 0;
- png_ptr->jmp_buf_ptr = NULL;
- png_ptr->longjmp_fn = 0;
- }
-}
-#endif
-
-/* This is the default error handling function. Note that replacements for
- * this function MUST NOT RETURN, or the program will likely crash. This
- * function is used by default, or if the program supplies NULL for the
- * error function pointer in png_set_error_fn().
- */
-static PNG_FUNCTION(void /* PRIVATE */,
-png_default_error,(png_const_structrp png_ptr, png_const_charp error_message),
- PNG_NORETURN)
-{
-#ifdef PNG_CONSOLE_IO_SUPPORTED
-#ifdef PNG_ERROR_NUMBERS_SUPPORTED
- /* Check on NULL only added in 1.5.4 */
- if (error_message != NULL && *error_message == PNG_LITERAL_SHARP)
- {
- /* Strip "#nnnn " from beginning of error message. */
- int offset;
- char error_number[16];
- for (offset = 0; offset<15; offset++)
- {
- error_number[offset] = error_message[offset + 1];
- if (error_message[offset] == ' ')
- break;
- }
-
- if ((offset > 1) && (offset < 15))
- {
- error_number[offset - 1] = '\0';
- fprintf(stderr, "libpng error no. %s: %s",
- error_number, error_message + offset + 1);
- fprintf(stderr, PNG_STRING_NEWLINE);
- }
-
- else
- {
- fprintf(stderr, "libpng error: %s, offset=%d",
- error_message, offset);
- fprintf(stderr, PNG_STRING_NEWLINE);
- }
- }
- else
-#endif
- {
- fprintf(stderr, "libpng error: %s", error_message ? error_message :
- "undefined");
- fprintf(stderr, PNG_STRING_NEWLINE);
- }
-#else
- PNG_UNUSED(error_message) /* Make compiler happy */
-#endif
- png_longjmp(png_ptr, 1);
-}
-
-PNG_FUNCTION(void,PNGAPI
-png_longjmp,(png_const_structrp png_ptr, int val),PNG_NORETURN)
-{
-#ifdef PNG_SETJMP_SUPPORTED
- if (png_ptr && png_ptr->longjmp_fn && png_ptr->jmp_buf_ptr)
- png_ptr->longjmp_fn(*png_ptr->jmp_buf_ptr, val);
-#endif
-
- /* Here if not setjmp support or if png_ptr is null. */
- PNG_ABORT();
-}
-
-#ifdef PNG_WARNINGS_SUPPORTED
-/* This function is called when there is a warning, but the library thinks
- * it can continue anyway. Replacement functions don't have to do anything
- * here if you don't want them to. In the default configuration, png_ptr is
- * not used, but it is passed in case it may be useful.
- */
-static void /* PRIVATE */
-png_default_warning(png_const_structrp png_ptr, png_const_charp warning_message)
-{
-#ifdef PNG_CONSOLE_IO_SUPPORTED
-# ifdef PNG_ERROR_NUMBERS_SUPPORTED
- if (*warning_message == PNG_LITERAL_SHARP)
- {
- int offset;
- char warning_number[16];
- for (offset = 0; offset < 15; offset++)
- {
- warning_number[offset] = warning_message[offset + 1];
- if (warning_message[offset] == ' ')
- break;
- }
-
- if ((offset > 1) && (offset < 15))
- {
- warning_number[offset + 1] = '\0';
- fprintf(stderr, "libpng warning no. %s: %s",
- warning_number, warning_message + offset);
- fprintf(stderr, PNG_STRING_NEWLINE);
- }
-
- else
- {
- fprintf(stderr, "libpng warning: %s",
- warning_message);
- fprintf(stderr, PNG_STRING_NEWLINE);
- }
- }
- else
-# endif
-
- {
- fprintf(stderr, "libpng warning: %s", warning_message);
- fprintf(stderr, PNG_STRING_NEWLINE);
- }
-#else
- PNG_UNUSED(warning_message) /* Make compiler happy */
-#endif
- PNG_UNUSED(png_ptr) /* Make compiler happy */
-}
-#endif /* PNG_WARNINGS_SUPPORTED */
-
-/* This function is called when the application wants to use another method
- * of handling errors and warnings. Note that the error function MUST NOT
- * return to the calling routine or serious problems will occur. The return
- * method used in the default routine calls longjmp(png_ptr->jmp_buf_ptr, 1)
- */
-void PNGAPI
-png_set_error_fn(png_structrp png_ptr, png_voidp error_ptr,
- png_error_ptr error_fn, png_error_ptr warning_fn)
-{
- if (png_ptr == NULL)
- return;
-
- png_ptr->error_ptr = error_ptr;
- png_ptr->error_fn = error_fn;
-#ifdef PNG_WARNINGS_SUPPORTED
- png_ptr->warning_fn = warning_fn;
-#else
- PNG_UNUSED(warning_fn)
-#endif
-}
-
-
-/* This function returns a pointer to the error_ptr associated with the user
- * functions. The application should free any memory associated with this
- * pointer before png_write_destroy and png_read_destroy are called.
- */
-png_voidp PNGAPI
-png_get_error_ptr(png_const_structrp png_ptr)
-{
- if (png_ptr == NULL)
- return NULL;
-
- return ((png_voidp)png_ptr->error_ptr);
-}
-
-
-#ifdef PNG_ERROR_NUMBERS_SUPPORTED
-void PNGAPI
-png_set_strip_error_numbers(png_structrp png_ptr, png_uint_32 strip_mode)
-{
- if (png_ptr != NULL)
- {
- png_ptr->flags &=
- ((~(PNG_FLAG_STRIP_ERROR_NUMBERS |
- PNG_FLAG_STRIP_ERROR_TEXT))&strip_mode);
- }
-}
-#endif
-
-#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) ||\
- defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
- /* Currently the above both depend on SETJMP_SUPPORTED, however it would be
- * possible to implement without setjmp support just so long as there is some
- * way to handle the error return here:
- */
-PNG_FUNCTION(void /* PRIVATE */,
-png_safe_error,(png_structp png_nonconst_ptr, png_const_charp error_message),
- PNG_NORETURN)
-{
- const png_const_structrp png_ptr = png_nonconst_ptr;
- png_imagep image = png_voidcast(png_imagep, png_ptr->error_ptr);
-
- /* An error is always logged here, overwriting anything (typically a warning)
- * that is already there:
- */
- if (image != NULL)
- {
- png_safecat(image->message, (sizeof image->message), 0, error_message);
- image->warning_or_error |= PNG_IMAGE_ERROR;
-
- /* Retrieve the jmp_buf from within the png_control, making this work for
- * C++ compilation too is pretty tricky: C++ wants a pointer to the first
- * element of a jmp_buf, but C doesn't tell us the type of that.
- */
- if (image->opaque != NULL && image->opaque->error_buf != NULL)
- longjmp(png_control_jmp_buf(image->opaque), 1);
-
- /* Missing longjmp buffer, the following is to help debugging: */
- {
- size_t pos = png_safecat(image->message, (sizeof image->message), 0,
- "bad longjmp: ");
- png_safecat(image->message, (sizeof image->message), pos,
- error_message);
- }
- }
-
- /* Here on an internal programming error. */
- abort();
-}
-
-#ifdef PNG_WARNINGS_SUPPORTED
-void /* PRIVATE */
-png_safe_warning(png_structp png_nonconst_ptr, png_const_charp warning_message)
-{
- const png_const_structrp png_ptr = png_nonconst_ptr;
- png_imagep image = png_voidcast(png_imagep, png_ptr->error_ptr);
-
- /* A warning is only logged if there is no prior warning or error. */
- if (image->warning_or_error == 0)
- {
- png_safecat(image->message, (sizeof image->message), 0, warning_message);
- image->warning_or_error |= PNG_IMAGE_WARNING;
- }
-}
-#endif
-
-int /* PRIVATE */
-png_safe_execute(png_imagep image_in, int (*function)(png_voidp), png_voidp arg)
-{
- volatile png_imagep image = image_in;
- volatile int result;
- volatile png_voidp saved_error_buf;
- jmp_buf safe_jmpbuf;
-
- /* Safely execute function(arg) with png_error returning to this function. */
- saved_error_buf = image->opaque->error_buf;
- result = setjmp(safe_jmpbuf) == 0;
-
- if (result)
- {
-
- image->opaque->error_buf = safe_jmpbuf;
- result = function(arg);
- }
-
- image->opaque->error_buf = saved_error_buf;
-
- /* And do the cleanup prior to any failure return. */
- if (!result)
- png_image_free(image);
-
- return result;
-}
-#endif /* SIMPLIFIED READ/WRITE */
-#endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */
+
+/* pngerror.c - stub functions for i/o and memory allocation
+ *
+ * Last changed in libpng 1.6.15 [November 20, 2014]
+ * Copyright (c) 1998-2014 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ * This file provides a location for all error handling. Users who
+ * need special error handling are expected to write replacement functions
+ * and use png_set_error_fn() to use those functions. See the instructions
+ * at each function.
+ */
+
+#include "pngpriv.h"
+
+#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
+
+static PNG_FUNCTION(void, png_default_error,PNGARG((png_const_structrp png_ptr,
+ png_const_charp error_message)),PNG_NORETURN);
+
+#ifdef PNG_WARNINGS_SUPPORTED
+static void /* PRIVATE */
+png_default_warning PNGARG((png_const_structrp png_ptr,
+ png_const_charp warning_message));
+#endif /* WARNINGS */
+
+/* This function is called whenever there is a fatal error. This function
+ * should not be changed. If there is a need to handle errors differently,
+ * you should supply a replacement error function and use png_set_error_fn()
+ * to replace the error function at run-time.
+ */
+#ifdef PNG_ERROR_TEXT_SUPPORTED
+PNG_FUNCTION(void,PNGAPI
+png_error,(png_const_structrp png_ptr, png_const_charp error_message),
+ PNG_NORETURN)
+{
+#ifdef PNG_ERROR_NUMBERS_SUPPORTED
+ char msg[16];
+ if (png_ptr != NULL)
+ {
+ if ((png_ptr->flags &
+ (PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT)) != 0
+ {
+ if (*error_message == PNG_LITERAL_SHARP)
+ {
+ /* Strip "#nnnn " from beginning of error message. */
+ int offset;
+ for (offset = 1; offset<15; offset++)
+ if (error_message[offset] == ' ')
+ break;
+
+ if ((png_ptr->flags & PNG_FLAG_STRIP_ERROR_TEXT) != 0)
+ {
+ int i;
+ for (i = 0; i < offset - 1; i++)
+ msg[i] = error_message[i + 1];
+ msg[i - 1] = '\0';
+ error_message = msg;
+ }
+
+ else
+ error_message += offset;
+ }
+
+ else
+ {
+ if ((png_ptr->flags & PNG_FLAG_STRIP_ERROR_TEXT) != 0)
+ {
+ msg[0] = '0';
+ msg[1] = '\0';
+ error_message = msg;
+ }
+ }
+ }
+ }
+#endif
+ if (png_ptr != NULL && png_ptr->error_fn != NULL)
+ (*(png_ptr->error_fn))(png_constcast(png_structrp,png_ptr),
+ error_message);
+
+ /* If the custom handler doesn't exist, or if it returns,
+ use the default handler, which will not return. */
+ png_default_error(png_ptr, error_message);
+}
+#else
+PNG_FUNCTION(void,PNGAPI
+png_err,(png_const_structrp png_ptr),PNG_NORETURN)
+{
+ /* Prior to 1.5.2 the error_fn received a NULL pointer, expressed
+ * erroneously as '\0', instead of the empty string "". This was
+ * apparently an error, introduced in libpng-1.2.20, and png_default_error
+ * will crash in this case.
+ */
+ if (png_ptr != NULL && png_ptr->error_fn != NULL)
+ (*(png_ptr->error_fn))(png_constcast(png_structrp,png_ptr), "");
+
+ /* If the custom handler doesn't exist, or if it returns,
+ use the default handler, which will not return. */
+ png_default_error(png_ptr, "");
+}
+#endif /* ERROR_TEXT */
+
+/* Utility to safely appends strings to a buffer. This never errors out so
+ * error checking is not required in the caller.
+ */
+size_t
+png_safecat(png_charp buffer, size_t bufsize, size_t pos,
+ png_const_charp string)
+{
+ if (buffer != NULL && pos < bufsize)
+ {
+ if (string != NULL)
+ while (*string != '\0' && pos < bufsize-1)
+ buffer[pos++] = *string++;
+
+ buffer[pos] = '\0';
+ }
+
+ return pos;
+}
+
+#if defined(PNG_WARNINGS_SUPPORTED) || defined(PNG_TIME_RFC1123_SUPPORTED)
+/* Utility to dump an unsigned value into a buffer, given a start pointer and
+ * and end pointer (which should point just *beyond* the end of the buffer!)
+ * Returns the pointer to the start of the formatted string.
+ */
+png_charp
+png_format_number(png_const_charp start, png_charp end, int format,
+ png_alloc_size_t number)
+{
+ int count = 0; /* number of digits output */
+ int mincount = 1; /* minimum number required */
+ int output = 0; /* digit output (for the fixed point format) */
+
+ *--end = '\0';
+
+ /* This is written so that the loop always runs at least once, even with
+ * number zero.
+ */
+ while (end > start && (number != 0 || count < mincount))
+ {
+
+ static const char digits[] = "0123456789ABCDEF";
+
+ switch (format)
+ {
+ case PNG_NUMBER_FORMAT_fixed:
+ /* Needs five digits (the fraction) */
+ mincount = 5;
+ if (output != 0 || number % 10 != 0)
+ {
+ *--end = digits[number % 10];
+ output = 1;
+ }
+ number /= 10;
+ break;
+
+ case PNG_NUMBER_FORMAT_02u:
+ /* Expects at least 2 digits. */
+ mincount = 2;
+ /* FALL THROUGH */
+
+ case PNG_NUMBER_FORMAT_u:
+ *--end = digits[number % 10];
+ number /= 10;
+ break;
+
+ case PNG_NUMBER_FORMAT_02x:
+ /* This format expects at least two digits */
+ mincount = 2;
+ /* FALL THROUGH */
+
+ case PNG_NUMBER_FORMAT_x:
+ *--end = digits[number & 0xf];
+ number >>= 4;
+ break;
+
+ default: /* an error */
+ number = 0;
+ break;
+ }
+
+ /* Keep track of the number of digits added */
+ ++count;
+
+ /* Float a fixed number here: */
+ if ((format == PNG_NUMBER_FORMAT_fixed) && (count == 5) && (end > start))
+ {
+ /* End of the fraction, but maybe nothing was output? In that case
+ * drop the decimal point. If the number is a true zero handle that
+ * here.
+ */
+ if (output != 0)
+ *--end = '.';
+ else if (number == 0) /* and !output */
+ *--end = '0';
+ }
+ }
+
+ return end;
+}
+#endif
+
+#ifdef PNG_WARNINGS_SUPPORTED
+/* This function is called whenever there is a non-fatal error. This function
+ * should not be changed. If there is a need to handle warnings differently,
+ * you should supply a replacement warning function and use
+ * png_set_error_fn() to replace the warning function at run-time.
+ */
+void PNGAPI
+png_warning(png_const_structrp png_ptr, png_const_charp warning_message)
+{
+ int offset = 0;
+ if (png_ptr != NULL)
+ {
+#ifdef PNG_ERROR_NUMBERS_SUPPORTED
+ if ((png_ptr->flags &
+ (PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT)) != 0)
+#endif
+ {
+ if (*warning_message == PNG_LITERAL_SHARP)
+ {
+ for (offset = 1; offset < 15; offset++)
+ if (warning_message[offset] == ' ')
+ break;
+ }
+ }
+ }
+ if (png_ptr != NULL && png_ptr->warning_fn != NULL)
+ (*(png_ptr->warning_fn))(png_constcast(png_structrp,png_ptr),
+ warning_message + offset);
+ else
+ png_default_warning(png_ptr, warning_message + offset);
+}
+
+/* These functions support 'formatted' warning messages with up to
+ * PNG_WARNING_PARAMETER_COUNT parameters. In the format string the parameter
+ * is introduced by @<number>, where 'number' starts at 1. This follows the
+ * standard established by X/Open for internationalizable error messages.
+ */
+void
+png_warning_parameter(png_warning_parameters p, int number,
+ png_const_charp string)
+{
+ if (number > 0 && number <= PNG_WARNING_PARAMETER_COUNT)
+ (void)png_safecat(p[number-1], (sizeof p[number-1]), 0, string);
+}
+
+void
+png_warning_parameter_unsigned(png_warning_parameters p, int number, int format,
+ png_alloc_size_t value)
+{
+ char buffer[PNG_NUMBER_BUFFER_SIZE];
+ png_warning_parameter(p, number, PNG_FORMAT_NUMBER(buffer, format, value));
+}
+
+void
+png_warning_parameter_signed(png_warning_parameters p, int number, int format,
+ png_int_32 value)
+{
+ png_alloc_size_t u;
+ png_charp str;
+ char buffer[PNG_NUMBER_BUFFER_SIZE];
+
+ /* Avoid overflow by doing the negate in a png_alloc_size_t: */
+ u = (png_alloc_size_t)value;
+ if (value < 0)
+ u = ~u + 1;
+
+ str = PNG_FORMAT_NUMBER(buffer, format, u);
+
+ if (value < 0 && str > buffer)
+ *--str = '-';
+
+ png_warning_parameter(p, number, str);
+}
+
+void
+png_formatted_warning(png_const_structrp png_ptr, png_warning_parameters p,
+ png_const_charp message)
+{
+ /* The internal buffer is just 192 bytes - enough for all our messages,
+ * overflow doesn't happen because this code checks! If someone figures
+ * out how to send us a message longer than 192 bytes, all that will
+ * happen is that the message will be truncated appropriately.
+ */
+ size_t i = 0; /* Index in the msg[] buffer: */
+ char msg[192];
+
+ /* Each iteration through the following loop writes at most one character
+ * to msg[i++] then returns here to validate that there is still space for
+ * the trailing '\0'. It may (in the case of a parameter) read more than
+ * one character from message[]; it must check for '\0' and continue to the
+ * test if it finds the end of string.
+ */
+ while (i<(sizeof msg)-1 && *message != '\0')
+ {
+ /* '@' at end of string is now just printed (previously it was skipped);
+ * it is an error in the calling code to terminate the string with @.
+ */
+ if (p != NULL && *message == '@' && message[1] != '\0')
+ {
+ int parameter_char = *++message; /* Consume the '@' */
+ static const char valid_parameters[] = "123456789";
+ int parameter = 0;
+
+ /* Search for the parameter digit, the index in the string is the
+ * parameter to use.
+ */
+ while (valid_parameters[parameter] != parameter_char &&
+ valid_parameters[parameter] != '\0')
+ ++parameter;
+
+ /* If the parameter digit is out of range it will just get printed. */
+ if (parameter < PNG_WARNING_PARAMETER_COUNT)
+ {
+ /* Append this parameter */
+ png_const_charp parm = p[parameter];
+ png_const_charp pend = p[parameter] + (sizeof p[parameter]);
+
+ /* No need to copy the trailing '\0' here, but there is no guarantee
+ * that parm[] has been initialized, so there is no guarantee of a
+ * trailing '\0':
+ */
+ while (i<(sizeof msg)-1 && *parm != '\0' && parm < pend)
+ msg[i++] = *parm++;
+
+ /* Consume the parameter digit too: */
+ ++message;
+ continue;
+ }
+
+ /* else not a parameter and there is a character after the @ sign; just
+ * copy that. This is known not to be '\0' because of the test above.
+ */
+ }
+
+ /* At this point *message can't be '\0', even in the bad parameter case
+ * above where there is a lone '@' at the end of the message string.
+ */
+ msg[i++] = *message++;
+ }
+
+ /* i is always less than (sizeof msg), so: */
+ msg[i] = '\0';
+
+ /* And this is the formatted message. It may be larger than
+ * PNG_MAX_ERROR_TEXT, but that is only used for 'chunk' errors and these
+ * are not (currently) formatted.
+ */
+ png_warning(png_ptr, msg);
+}
+#endif /* WARNINGS */
+
+#ifdef PNG_BENIGN_ERRORS_SUPPORTED
+void PNGAPI
+png_benign_error(png_const_structrp png_ptr, png_const_charp error_message)
+{
+ if ((png_ptr->flags & PNG_FLAG_BENIGN_ERRORS_WARN) != 0)
+ {
+# ifdef PNG_READ_SUPPORTED
+ if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0 &&
+ png_ptr->chunk_name != 0)
+ png_chunk_warning(png_ptr, error_message);
+ else
+# endif
+ png_warning(png_ptr, error_message);
+ }
+
+ else
+ {
+# ifdef PNG_READ_SUPPORTED
+ if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0 &&
+ png_ptr->chunk_name != 0)
+ png_chunk_error(png_ptr, error_message);
+ else
+# endif
+ png_error(png_ptr, error_message);
+ }
+
+# ifndef PNG_ERROR_TEXT_SUPPORTED
+ PNG_UNUSED(error_message)
+# endif
+}
+
+void /* PRIVATE */
+png_app_warning(png_const_structrp png_ptr, png_const_charp error_message)
+{
+ if ((png_ptr->flags & PNG_FLAG_APP_WARNINGS_WARN) != 0)
+ png_warning(png_ptr, error_message);
+ else
+ png_error(png_ptr, error_message);
+
+# ifndef PNG_ERROR_TEXT_SUPPORTED
+ PNG_UNUSED(error_message)
+# endif
+}
+
+void /* PRIVATE */
+png_app_error(png_const_structrp png_ptr, png_const_charp error_message)
+{
+ if ((png_ptr->flags & PNG_FLAG_APP_ERRORS_WARN) != 0)
+ png_warning(png_ptr, error_message);
+ else
+ png_error(png_ptr, error_message);
+
+# ifndef PNG_ERROR_TEXT_SUPPORTED
+ PNG_UNUSED(error_message)
+# endif
+}
+#endif /* BENIGN_ERRORS */
+
+#define PNG_MAX_ERROR_TEXT 196 /* Currently limited by profile_error in png.c */
+#if defined(PNG_WARNINGS_SUPPORTED) || \
+ (defined(PNG_READ_SUPPORTED) && defined(PNG_ERROR_TEXT_SUPPORTED))
+/* These utilities are used internally to build an error message that relates
+ * to the current chunk. The chunk name comes from png_ptr->chunk_name,
+ * which is used to prefix the message. The message is limited in length
+ * to 63 bytes. The name characters are output as hex digits wrapped in []
+ * if the character is invalid.
+ */
+#define isnonalpha(c) ((c) < 65 || (c) > 122 || ((c) > 90 && (c) < 97))
+static PNG_CONST char png_digit[16] = {
+ '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
+ 'A', 'B', 'C', 'D', 'E', 'F'
+};
+
+static void /* PRIVATE */
+png_format_buffer(png_const_structrp png_ptr, png_charp buffer, png_const_charp
+ error_message)
+{
+ png_uint_32 chunk_name = png_ptr->chunk_name;
+ int iout = 0, ishift = 24;
+
+ while (ishift >= 0)
+ {
+ int c = (int)(chunk_name >> ishift) & 0xff;
+
+ ishift -= 8;
+ if (isnonalpha(c) != 0)
+ {
+ buffer[iout++] = PNG_LITERAL_LEFT_SQUARE_BRACKET;
+ buffer[iout++] = png_digit[(c & 0xf0) >> 4];
+ buffer[iout++] = png_digit[c & 0x0f];
+ buffer[iout++] = PNG_LITERAL_RIGHT_SQUARE_BRACKET;
+ }
+
+ else
+ {
+ buffer[iout++] = (char)c;
+ }
+ }
+
+ if (error_message == NULL)
+ buffer[iout] = '\0';
+
+ else
+ {
+ int iin = 0;
+
+ buffer[iout++] = ':';
+ buffer[iout++] = ' ';
+
+ while (iin < PNG_MAX_ERROR_TEXT-1 && error_message[iin] != '\0')
+ buffer[iout++] = error_message[iin++];
+
+ /* iin < PNG_MAX_ERROR_TEXT, so the following is safe: */
+ buffer[iout] = '\0';
+ }
+}
+#endif /* WARNINGS || ERROR_TEXT */
+
+#if defined(PNG_READ_SUPPORTED) && defined(PNG_ERROR_TEXT_SUPPORTED)
+PNG_FUNCTION(void,PNGAPI
+png_chunk_error,(png_const_structrp png_ptr, png_const_charp error_message),
+ PNG_NORETURN)
+{
+ char msg[18+PNG_MAX_ERROR_TEXT];
+ if (png_ptr == NULL)
+ png_error(png_ptr, error_message);
+
+ else
+ {
+ png_format_buffer(png_ptr, msg, error_message);
+ png_error(png_ptr, msg);
+ }
+}
+#endif /* READ && ERROR_TEXT */
+
+#ifdef PNG_WARNINGS_SUPPORTED
+void PNGAPI
+png_chunk_warning(png_const_structrp png_ptr, png_const_charp warning_message)
+{
+ char msg[18+PNG_MAX_ERROR_TEXT];
+ if (png_ptr == NULL)
+ png_warning(png_ptr, warning_message);
+
+ else
+ {
+ png_format_buffer(png_ptr, msg, warning_message);
+ png_warning(png_ptr, msg);
+ }
+}
+#endif /* WARNINGS */
+
+#ifdef PNG_READ_SUPPORTED
+#ifdef PNG_BENIGN_ERRORS_SUPPORTED
+void PNGAPI
+png_chunk_benign_error(png_const_structrp png_ptr, png_const_charp
+ error_message)
+{
+ if ((png_ptr->flags & PNG_FLAG_BENIGN_ERRORS_WARN) != 0)
+ png_chunk_warning(png_ptr, error_message);
+
+ else
+ png_chunk_error(png_ptr, error_message);
+
+# ifndef PNG_ERROR_TEXT_SUPPORTED
+ PNG_UNUSED(error_message)
+# endif
+}
+#endif
+#endif /* READ */
+
+void /* PRIVATE */
+png_chunk_report(png_const_structrp png_ptr, png_const_charp message, int error)
+{
+# ifndef PNG_WARNINGS_SUPPORTED
+ PNG_UNUSED(message)
+# endif
+
+ /* This is always supported, but for just read or just write it
+ * unconditionally does the right thing.
+ */
+# if defined(PNG_READ_SUPPORTED) && defined(PNG_WRITE_SUPPORTED)
+ if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0)
+# endif
+
+# ifdef PNG_READ_SUPPORTED
+ {
+ if (error < PNG_CHUNK_ERROR)
+ png_chunk_warning(png_ptr, message);
+
+ else
+ png_chunk_benign_error(png_ptr, message);
+ }
+# endif
+
+# if defined(PNG_READ_SUPPORTED) && defined(PNG_WRITE_SUPPORTED)
+ else if ((png_ptr->mode & PNG_IS_READ_STRUCT) == 0)
+# endif
+
+# ifdef PNG_WRITE_SUPPORTED
+ {
+ if (error < PNG_CHUNK_WRITE_ERROR)
+ png_app_warning(png_ptr, message);
+
+ else
+ png_app_error(png_ptr, message);
+ }
+# endif
+}
+
+#ifdef PNG_ERROR_TEXT_SUPPORTED
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+PNG_FUNCTION(void,
+png_fixed_error,(png_const_structrp png_ptr, png_const_charp name),PNG_NORETURN)
+{
+# define fixed_message "fixed point overflow in "
+# define fixed_message_ln ((sizeof fixed_message)-1)
+ int iin;
+ char msg[fixed_message_ln+PNG_MAX_ERROR_TEXT];
+ memcpy(msg, fixed_message, fixed_message_ln);
+ iin = 0;
+ if (name != NULL)
+ while (iin < (PNG_MAX_ERROR_TEXT-1) && name[iin] != 0)
+ {
+ msg[fixed_message_ln + iin] = name[iin];
+ ++iin;
+ }
+ msg[fixed_message_ln + iin] = 0;
+ png_error(png_ptr, msg);
+}
+#endif
+#endif
+
+#ifdef PNG_SETJMP_SUPPORTED
+/* This API only exists if ANSI-C style error handling is used,
+ * otherwise it is necessary for png_default_error to be overridden.
+ */
+jmp_buf* PNGAPI
+png_set_longjmp_fn(png_structrp png_ptr, png_longjmp_ptr longjmp_fn,
+ size_t jmp_buf_size)
+{
+ /* From libpng 1.6.0 the app gets one chance to set a 'jmpbuf_size' value
+ * and it must not change after that. Libpng doesn't care how big the
+ * buffer is, just that it doesn't change.
+ *
+ * If the buffer size is no *larger* than the size of jmp_buf when libpng is
+ * compiled a built in jmp_buf is returned; this preserves the pre-1.6.0
+ * semantics that this call will not fail. If the size is larger, however,
+ * the buffer is allocated and this may fail, causing the function to return
+ * NULL.
+ */
+ if (png_ptr == NULL)
+ return NULL;
+
+ if (png_ptr->jmp_buf_ptr == NULL)
+ {
+ png_ptr->jmp_buf_size = 0; /* not allocated */
+
+ if (jmp_buf_size <= (sizeof png_ptr->jmp_buf_local))
+ png_ptr->jmp_buf_ptr = &png_ptr->jmp_buf_local;
+
+ else
+ {
+ png_ptr->jmp_buf_ptr = png_voidcast(jmp_buf *,
+ png_malloc_warn(png_ptr, jmp_buf_size));
+
+ if (png_ptr->jmp_buf_ptr == NULL)
+ return NULL; /* new NULL return on OOM */
+
+ png_ptr->jmp_buf_size = jmp_buf_size;
+ }
+ }
+
+ else /* Already allocated: check the size */
+ {
+ size_t size = png_ptr->jmp_buf_size;
+
+ if (size == 0)
+ {
+ size = (sizeof png_ptr->jmp_buf_local);
+ if (png_ptr->jmp_buf_ptr != &png_ptr->jmp_buf_local)
+ {
+ /* This is an internal error in libpng: somehow we have been left
+ * with a stack allocated jmp_buf when the application regained
+ * control. It's always possible to fix this up, but for the moment
+ * this is a png_error because that makes it easy to detect.
+ */
+ png_error(png_ptr, "Libpng jmp_buf still allocated");
+ /* png_ptr->jmp_buf_ptr = &png_ptr->jmp_buf_local; */
+ }
+ }
+
+ if (size != jmp_buf_size)
+ {
+ png_warning(png_ptr, "Application jmp_buf size changed");
+ return NULL; /* caller will probably crash: no choice here */
+ }
+ }
+
+ /* Finally fill in the function, now we have a satisfactory buffer. It is
+ * valid to change the function on every call.
+ */
+ png_ptr->longjmp_fn = longjmp_fn;
+ return png_ptr->jmp_buf_ptr;
+}
+
+void /* PRIVATE */
+png_free_jmpbuf(png_structrp png_ptr)
+{
+ if (png_ptr != NULL)
+ {
+ jmp_buf *jb = png_ptr->jmp_buf_ptr;
+
+ /* A size of 0 is used to indicate a local, stack, allocation of the
+ * pointer; used here and in png.c
+ */
+ if (jb != NULL && png_ptr->jmp_buf_size > 0)
+ {
+
+ /* This stuff is so that a failure to free the error control structure
+ * does not leave libpng in a state with no valid error handling: the
+ * free always succeeds, if there is an error it gets ignored.
+ */
+ if (jb != &png_ptr->jmp_buf_local)
+ {
+ /* Make an internal, libpng, jmp_buf to return here */
+ jmp_buf free_jmp_buf;
+
+ if (!setjmp(free_jmp_buf))
+ {
+ png_ptr->jmp_buf_ptr = &free_jmp_buf; /* come back here */
+ png_ptr->jmp_buf_size = 0; /* stack allocation */
+ png_ptr->longjmp_fn = longjmp;
+ png_free(png_ptr, jb); /* Return to setjmp on error */
+ }
+ }
+ }
+
+ /* *Always* cancel everything out: */
+ png_ptr->jmp_buf_size = 0;
+ png_ptr->jmp_buf_ptr = NULL;
+ png_ptr->longjmp_fn = 0;
+ }
+}
+#endif
+
+/* This is the default error handling function. Note that replacements for
+ * this function MUST NOT RETURN, or the program will likely crash. This
+ * function is used by default, or if the program supplies NULL for the
+ * error function pointer in png_set_error_fn().
+ */
+static PNG_FUNCTION(void /* PRIVATE */,
+png_default_error,(png_const_structrp png_ptr, png_const_charp error_message),
+ PNG_NORETURN)
+{
+#ifdef PNG_CONSOLE_IO_SUPPORTED
+#ifdef PNG_ERROR_NUMBERS_SUPPORTED
+ /* Check on NULL only added in 1.5.4 */
+ if (error_message != NULL && *error_message == PNG_LITERAL_SHARP)
+ {
+ /* Strip "#nnnn " from beginning of error message. */
+ int offset;
+ char error_number[16];
+ for (offset = 0; offset<15; offset++)
+ {
+ error_number[offset] = error_message[offset + 1];
+ if (error_message[offset] == ' ')
+ break;
+ }
+
+ if ((offset > 1) && (offset < 15))
+ {
+ error_number[offset - 1] = '\0';
+ fprintf(stderr, "libpng error no. %s: %s",
+ error_number, error_message + offset + 1);
+ fprintf(stderr, PNG_STRING_NEWLINE);
+ }
+
+ else
+ {
+ fprintf(stderr, "libpng error: %s, offset=%d",
+ error_message, offset);
+ fprintf(stderr, PNG_STRING_NEWLINE);
+ }
+ }
+ else
+#endif
+ {
+ fprintf(stderr, "libpng error: %s", error_message ? error_message :
+ "undefined");
+ fprintf(stderr, PNG_STRING_NEWLINE);
+ }
+#else
+ PNG_UNUSED(error_message) /* Make compiler happy */
+#endif
+ png_longjmp(png_ptr, 1);
+}
+
+PNG_FUNCTION(void,PNGAPI
+png_longjmp,(png_const_structrp png_ptr, int val),PNG_NORETURN)
+{
+#ifdef PNG_SETJMP_SUPPORTED
+ if (png_ptr != NULL && png_ptr->longjmp_fn != NULL &&
+ png_ptr->jmp_buf_ptr != NULL)
+ png_ptr->longjmp_fn(*png_ptr->jmp_buf_ptr, val);
+#else
+ PNG_UNUSED(png_ptr)
+ PNG_UNUSED(val)
+#endif
+
+ /* If control reaches this point, png_longjmp() must not return. The only
+ * choice is to terminate the whole process (or maybe the thread); to do
+ * this the ANSI-C abort() function is used unless a different method is
+ * implemented by overriding the default configuration setting for
+ * PNG_ABORT().
+ */
+ PNG_ABORT();
+}
+
+#ifdef PNG_WARNINGS_SUPPORTED
+/* This function is called when there is a warning, but the library thinks
+ * it can continue anyway. Replacement functions don't have to do anything
+ * here if you don't want them to. In the default configuration, png_ptr is
+ * not used, but it is passed in case it may be useful.
+ */
+static void /* PRIVATE */
+png_default_warning(png_const_structrp png_ptr, png_const_charp warning_message)
+{
+#ifdef PNG_CONSOLE_IO_SUPPORTED
+# ifdef PNG_ERROR_NUMBERS_SUPPORTED
+ if (*warning_message == PNG_LITERAL_SHARP)
+ {
+ int offset;
+ char warning_number[16];
+ for (offset = 0; offset < 15; offset++)
+ {
+ warning_number[offset] = warning_message[offset + 1];
+ if (warning_message[offset] == ' ')
+ break;
+ }
+
+ if ((offset > 1) && (offset < 15))
+ {
+ warning_number[offset + 1] = '\0';
+ fprintf(stderr, "libpng warning no. %s: %s",
+ warning_number, warning_message + offset);
+ fprintf(stderr, PNG_STRING_NEWLINE);
+ }
+
+ else
+ {
+ fprintf(stderr, "libpng warning: %s",
+ warning_message);
+ fprintf(stderr, PNG_STRING_NEWLINE);
+ }
+ }
+ else
+# endif
+
+ {
+ fprintf(stderr, "libpng warning: %s", warning_message);
+ fprintf(stderr, PNG_STRING_NEWLINE);
+ }
+#else
+ PNG_UNUSED(warning_message) /* Make compiler happy */
+#endif
+ PNG_UNUSED(png_ptr) /* Make compiler happy */
+}
+#endif /* WARNINGS */
+
+/* This function is called when the application wants to use another method
+ * of handling errors and warnings. Note that the error function MUST NOT
+ * return to the calling routine or serious problems will occur. The return
+ * method used in the default routine calls longjmp(png_ptr->jmp_buf_ptr, 1)
+ */
+void PNGAPI
+png_set_error_fn(png_structrp png_ptr, png_voidp error_ptr,
+ png_error_ptr error_fn, png_error_ptr warning_fn)
+{
+ if (png_ptr == NULL)
+ return;
+
+ png_ptr->error_ptr = error_ptr;
+ png_ptr->error_fn = error_fn;
+#ifdef PNG_WARNINGS_SUPPORTED
+ png_ptr->warning_fn = warning_fn;
+#else
+ PNG_UNUSED(warning_fn)
+#endif
+}
+
+
+/* This function returns a pointer to the error_ptr associated with the user
+ * functions. The application should free any memory associated with this
+ * pointer before png_write_destroy and png_read_destroy are called.
+ */
+png_voidp PNGAPI
+png_get_error_ptr(png_const_structrp png_ptr)
+{
+ if (png_ptr == NULL)
+ return NULL;
+
+ return ((png_voidp)png_ptr->error_ptr);
+}
+
+
+#ifdef PNG_ERROR_NUMBERS_SUPPORTED
+void PNGAPI
+png_set_strip_error_numbers(png_structrp png_ptr, png_uint_32 strip_mode)
+{
+ if (png_ptr != NULL)
+ {
+ png_ptr->flags &=
+ ((~(PNG_FLAG_STRIP_ERROR_NUMBERS |
+ PNG_FLAG_STRIP_ERROR_TEXT))&strip_mode);
+ }
+}
+#endif
+
+#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) ||\
+ defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
+ /* Currently the above both depend on SETJMP_SUPPORTED, however it would be
+ * possible to implement without setjmp support just so long as there is some
+ * way to handle the error return here:
+ */
+PNG_FUNCTION(void /* PRIVATE */, (PNGCBAPI
+png_safe_error),(png_structp png_nonconst_ptr, png_const_charp error_message),
+ PNG_NORETURN)
+{
+ const png_const_structrp png_ptr = png_nonconst_ptr;
+ png_imagep image = png_voidcast(png_imagep, png_ptr->error_ptr);
+
+ /* An error is always logged here, overwriting anything (typically a warning)
+ * that is already there:
+ */
+ if (image != NULL)
+ {
+ png_safecat(image->message, (sizeof image->message), 0, error_message);
+ image->warning_or_error |= PNG_IMAGE_ERROR;
+
+ /* Retrieve the jmp_buf from within the png_control, making this work for
+ * C++ compilation too is pretty tricky: C++ wants a pointer to the first
+ * element of a jmp_buf, but C doesn't tell us the type of that.
+ */
+ if (image->opaque != NULL && image->opaque->error_buf != NULL)
+ longjmp(png_control_jmp_buf(image->opaque), 1);
+
+ /* Missing longjmp buffer, the following is to help debugging: */
+ {
+ size_t pos = png_safecat(image->message, (sizeof image->message), 0,
+ "bad longjmp: ");
+ png_safecat(image->message, (sizeof image->message), pos,
+ error_message);
+ }
+ }
+
+ /* Here on an internal programming error. */
+ abort();
+}
+
+#ifdef PNG_WARNINGS_SUPPORTED
+void /* PRIVATE */ PNGCBAPI
+png_safe_warning(png_structp png_nonconst_ptr, png_const_charp warning_message)
+{
+ const png_const_structrp png_ptr = png_nonconst_ptr;
+ png_imagep image = png_voidcast(png_imagep, png_ptr->error_ptr);
+
+ /* A warning is only logged if there is no prior warning or error. */
+ if (image->warning_or_error == 0)
+ {
+ png_safecat(image->message, (sizeof image->message), 0, warning_message);
+ image->warning_or_error |= PNG_IMAGE_WARNING;
+ }
+}
+#endif
+
+int /* PRIVATE */
+png_safe_execute(png_imagep image_in, int (*function)(png_voidp), png_voidp arg)
+{
+ volatile png_imagep image = image_in;
+ volatile int result;
+ volatile png_voidp saved_error_buf;
+ jmp_buf safe_jmpbuf;
+
+ /* Safely execute function(arg) with png_error returning to this function. */
+ saved_error_buf = image->opaque->error_buf;
+ result = setjmp(safe_jmpbuf) == 0;
+
+ if (result != 0)
+ {
+
+ image->opaque->error_buf = safe_jmpbuf;
+ result = function(arg);
+ }
+
+ image->opaque->error_buf = saved_error_buf;
+
+ /* And do the cleanup prior to any failure return. */
+ if (result == 0)
+ png_image_free(image);
+
+ return result;
+}
+#endif /* SIMPLIFIED READ || SIMPLIFIED_WRITE */
+#endif /* READ || WRITE */
diff --git a/third_party/lpng_v163/pngget.c b/third_party/libpng/pngget.c
similarity index 87%
rename from third_party/lpng_v163/pngget.c
rename to third_party/libpng/pngget.c
index 6839f6b..743a6a9 100644
--- a/third_party/lpng_v163/pngget.c
+++ b/third_party/libpng/pngget.c
@@ -1,1176 +1,1219 @@
-/* pngget.c - retrieval of values from info struct
- *
- * Last changed in libpng 1.6.1 [March 28, 2013]
- * Copyright (c) 1998-2013 Glenn Randers-Pehrson
- * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
- * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
- *
- * This code is released under the libpng license.
- * For conditions of distribution and use, see the disclaimer
- * and license in png.h
- *
- */
-
-#include "pngpriv.h"
-
-#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
-
-png_uint_32 PNGAPI
-png_get_valid(png_const_structrp png_ptr, png_const_inforp info_ptr,
- png_uint_32 flag)
-{
- if (png_ptr != NULL && info_ptr != NULL)
- return(info_ptr->valid & flag);
-
- return(0);
-}
-
-png_size_t PNGAPI
-png_get_rowbytes(png_const_structrp png_ptr, png_const_inforp info_ptr)
-{
- if (png_ptr != NULL && info_ptr != NULL)
- return(info_ptr->rowbytes);
-
- return(0);
-}
-
-#ifdef PNG_INFO_IMAGE_SUPPORTED
-png_bytepp PNGAPI
-png_get_rows(png_const_structrp png_ptr, png_const_inforp info_ptr)
-{
- if (png_ptr != NULL && info_ptr != NULL)
- return(info_ptr->row_pointers);
-
- return(0);
-}
-#endif
-
-#ifdef PNG_EASY_ACCESS_SUPPORTED
-/* Easy access to info, added in libpng-0.99 */
-png_uint_32 PNGAPI
-png_get_image_width(png_const_structrp png_ptr, png_const_inforp info_ptr)
-{
- if (png_ptr != NULL && info_ptr != NULL)
- return info_ptr->width;
-
- return (0);
-}
-
-png_uint_32 PNGAPI
-png_get_image_height(png_const_structrp png_ptr, png_const_inforp info_ptr)
-{
- if (png_ptr != NULL && info_ptr != NULL)
- return info_ptr->height;
-
- return (0);
-}
-
-png_byte PNGAPI
-png_get_bit_depth(png_const_structrp png_ptr, png_const_inforp info_ptr)
-{
- if (png_ptr != NULL && info_ptr != NULL)
- return info_ptr->bit_depth;
-
- return (0);
-}
-
-png_byte PNGAPI
-png_get_color_type(png_const_structrp png_ptr, png_const_inforp info_ptr)
-{
- if (png_ptr != NULL && info_ptr != NULL)
- return info_ptr->color_type;
-
- return (0);
-}
-
-png_byte PNGAPI
-png_get_filter_type(png_const_structrp png_ptr, png_const_inforp info_ptr)
-{
- if (png_ptr != NULL && info_ptr != NULL)
- return info_ptr->filter_type;
-
- return (0);
-}
-
-png_byte PNGAPI
-png_get_interlace_type(png_const_structrp png_ptr, png_const_inforp info_ptr)
-{
- if (png_ptr != NULL && info_ptr != NULL)
- return info_ptr->interlace_type;
-
- return (0);
-}
-
-png_byte PNGAPI
-png_get_compression_type(png_const_structrp png_ptr, png_const_inforp info_ptr)
-{
- if (png_ptr != NULL && info_ptr != NULL)
- return info_ptr->compression_type;
-
- return (0);
-}
-
-png_uint_32 PNGAPI
-png_get_x_pixels_per_meter(png_const_structrp png_ptr, png_const_inforp
- info_ptr)
-{
-#ifdef PNG_pHYs_SUPPORTED
- if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs))
- {
- png_debug1(1, "in %s retrieval function",
- "png_get_x_pixels_per_meter");
-
- if (info_ptr->phys_unit_type == PNG_RESOLUTION_METER)
- return (info_ptr->x_pixels_per_unit);
- }
-#endif
-
- return (0);
-}
-
-png_uint_32 PNGAPI
-png_get_y_pixels_per_meter(png_const_structrp png_ptr, png_const_inforp
- info_ptr)
-{
-#ifdef PNG_pHYs_SUPPORTED
- if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs))
- {
- png_debug1(1, "in %s retrieval function",
- "png_get_y_pixels_per_meter");
-
- if (info_ptr->phys_unit_type == PNG_RESOLUTION_METER)
- return (info_ptr->y_pixels_per_unit);
- }
-#endif
-
- return (0);
-}
-
-png_uint_32 PNGAPI
-png_get_pixels_per_meter(png_const_structrp png_ptr, png_const_inforp info_ptr)
-{
-#ifdef PNG_pHYs_SUPPORTED
- if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs))
- {
- png_debug1(1, "in %s retrieval function", "png_get_pixels_per_meter");
-
- if (info_ptr->phys_unit_type == PNG_RESOLUTION_METER &&
- info_ptr->x_pixels_per_unit == info_ptr->y_pixels_per_unit)
- return (info_ptr->x_pixels_per_unit);
- }
-#endif
-
- return (0);
-}
-
-#ifdef PNG_FLOATING_POINT_SUPPORTED
-float PNGAPI
-png_get_pixel_aspect_ratio(png_const_structrp png_ptr, png_const_inforp
- info_ptr)
-{
-#ifdef PNG_READ_pHYs_SUPPORTED
- if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs))
- {
- png_debug1(1, "in %s retrieval function", "png_get_aspect_ratio");
-
- if (info_ptr->x_pixels_per_unit != 0)
- return ((float)((float)info_ptr->y_pixels_per_unit
- /(float)info_ptr->x_pixels_per_unit));
- }
-#else
- PNG_UNUSED(png_ptr)
- PNG_UNUSED(info_ptr)
-#endif
-
- return ((float)0.0);
-}
-#endif
-
-#ifdef PNG_FIXED_POINT_SUPPORTED
-png_fixed_point PNGAPI
-png_get_pixel_aspect_ratio_fixed(png_const_structrp png_ptr,
- png_const_inforp info_ptr)
-{
-#ifdef PNG_READ_pHYs_SUPPORTED
- if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs)
- && info_ptr->x_pixels_per_unit > 0 && info_ptr->y_pixels_per_unit > 0
- && info_ptr->x_pixels_per_unit <= PNG_UINT_31_MAX
- && info_ptr->y_pixels_per_unit <= PNG_UINT_31_MAX)
- {
- png_fixed_point res;
-
- png_debug1(1, "in %s retrieval function", "png_get_aspect_ratio_fixed");
-
- /* The following casts work because a PNG 4 byte integer only has a valid
- * range of 0..2^31-1; otherwise the cast might overflow.
- */
- if (png_muldiv(&res, (png_int_32)info_ptr->y_pixels_per_unit, PNG_FP_1,
- (png_int_32)info_ptr->x_pixels_per_unit))
- return res;
- }
-#else
- PNG_UNUSED(png_ptr)
- PNG_UNUSED(info_ptr)
-#endif
-
- return 0;
-}
-#endif
-
-png_int_32 PNGAPI
-png_get_x_offset_microns(png_const_structrp png_ptr, png_const_inforp info_ptr)
-{
-#ifdef PNG_oFFs_SUPPORTED
- if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs))
- {
- png_debug1(1, "in %s retrieval function", "png_get_x_offset_microns");
-
- if (info_ptr->offset_unit_type == PNG_OFFSET_MICROMETER)
- return (info_ptr->x_offset);
- }
-#endif
-
- return (0);
-}
-
-png_int_32 PNGAPI
-png_get_y_offset_microns(png_const_structrp png_ptr, png_const_inforp info_ptr)
-{
-#ifdef PNG_oFFs_SUPPORTED
- if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs))
- {
- png_debug1(1, "in %s retrieval function", "png_get_y_offset_microns");
-
- if (info_ptr->offset_unit_type == PNG_OFFSET_MICROMETER)
- return (info_ptr->y_offset);
- }
-#endif
-
- return (0);
-}
-
-png_int_32 PNGAPI
-png_get_x_offset_pixels(png_const_structrp png_ptr, png_const_inforp info_ptr)
-{
-#ifdef PNG_oFFs_SUPPORTED
- if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs))
- {
- png_debug1(1, "in %s retrieval function", "png_get_x_offset_pixels");
-
- if (info_ptr->offset_unit_type == PNG_OFFSET_PIXEL)
- return (info_ptr->x_offset);
- }
-#endif
-
- return (0);
-}
-
-png_int_32 PNGAPI
-png_get_y_offset_pixels(png_const_structrp png_ptr, png_const_inforp info_ptr)
-{
-#ifdef PNG_oFFs_SUPPORTED
- if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs))
- {
- png_debug1(1, "in %s retrieval function", "png_get_y_offset_pixels");
-
- if (info_ptr->offset_unit_type == PNG_OFFSET_PIXEL)
- return (info_ptr->y_offset);
- }
-#endif
-
- return (0);
-}
-
-#ifdef PNG_INCH_CONVERSIONS_SUPPORTED
-static png_uint_32
-ppi_from_ppm(png_uint_32 ppm)
-{
-#if 0
- /* The conversion is *(2.54/100), in binary (32 digits):
- * .00000110100000001001110101001001
- */
- png_uint_32 t1001, t1101;
- ppm >>= 1; /* .1 */
- t1001 = ppm + (ppm >> 3); /* .1001 */
- t1101 = t1001 + (ppm >> 1); /* .1101 */
- ppm >>= 20; /* .000000000000000000001 */
- t1101 += t1101 >> 15; /* .1101000000000001101 */
- t1001 >>= 11; /* .000000000001001 */
- t1001 += t1001 >> 12; /* .000000000001001000000001001 */
- ppm += t1001; /* .000000000001001000001001001 */
- ppm += t1101; /* .110100000001001110101001001 */
- return (ppm + 16) >> 5;/* .00000110100000001001110101001001 */
-#else
- /* The argument is a PNG unsigned integer, so it is not permitted
- * to be bigger than 2^31.
- */
- png_fixed_point result;
- if (ppm <= PNG_UINT_31_MAX && png_muldiv(&result, (png_int_32)ppm, 127,
- 5000))
- return result;
-
- /* Overflow. */
- return 0;
-#endif
-}
-
-png_uint_32 PNGAPI
-png_get_pixels_per_inch(png_const_structrp png_ptr, png_const_inforp info_ptr)
-{
- return ppi_from_ppm(png_get_pixels_per_meter(png_ptr, info_ptr));
-}
-
-png_uint_32 PNGAPI
-png_get_x_pixels_per_inch(png_const_structrp png_ptr, png_const_inforp info_ptr)
-{
- return ppi_from_ppm(png_get_x_pixels_per_meter(png_ptr, info_ptr));
-}
-
-png_uint_32 PNGAPI
-png_get_y_pixels_per_inch(png_const_structrp png_ptr, png_const_inforp info_ptr)
-{
- return ppi_from_ppm(png_get_y_pixels_per_meter(png_ptr, info_ptr));
-}
-
-#ifdef PNG_FIXED_POINT_SUPPORTED
-static png_fixed_point
-png_fixed_inches_from_microns(png_const_structrp png_ptr, png_int_32 microns)
-{
- /* Convert from metres * 1,000,000 to inches * 100,000, meters to
- * inches is simply *(100/2.54), so we want *(10/2.54) == 500/127.
- * Notice that this can overflow - a warning is output and 0 is
- * returned.
- */
- return png_muldiv_warn(png_ptr, microns, 500, 127);
-}
-
-png_fixed_point PNGAPI
-png_get_x_offset_inches_fixed(png_const_structrp png_ptr,
- png_const_inforp info_ptr)
-{
- return png_fixed_inches_from_microns(png_ptr,
- png_get_x_offset_microns(png_ptr, info_ptr));
-}
-#endif
-
-#ifdef PNG_FIXED_POINT_SUPPORTED
-png_fixed_point PNGAPI
-png_get_y_offset_inches_fixed(png_const_structrp png_ptr,
- png_const_inforp info_ptr)
-{
- return png_fixed_inches_from_microns(png_ptr,
- png_get_y_offset_microns(png_ptr, info_ptr));
-}
-#endif
-
-#ifdef PNG_FLOATING_POINT_SUPPORTED
-float PNGAPI
-png_get_x_offset_inches(png_const_structrp png_ptr, png_const_inforp info_ptr)
-{
- /* To avoid the overflow do the conversion directly in floating
- * point.
- */
- return (float)(png_get_x_offset_microns(png_ptr, info_ptr) * .00003937);
-}
-#endif
-
-#ifdef PNG_FLOATING_POINT_SUPPORTED
-float PNGAPI
-png_get_y_offset_inches(png_const_structrp png_ptr, png_const_inforp info_ptr)
-{
- /* To avoid the overflow do the conversion directly in floating
- * point.
- */
- return (float)(png_get_y_offset_microns(png_ptr, info_ptr) * .00003937);
-}
-#endif
-
-#ifdef PNG_pHYs_SUPPORTED
-png_uint_32 PNGAPI
-png_get_pHYs_dpi(png_const_structrp png_ptr, png_const_inforp info_ptr,
- png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type)
-{
- png_uint_32 retval = 0;
-
- if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs))
- {
- png_debug1(1, "in %s retrieval function", "pHYs");
-
- if (res_x != NULL)
- {
- *res_x = info_ptr->x_pixels_per_unit;
- retval |= PNG_INFO_pHYs;
- }
-
- if (res_y != NULL)
- {
- *res_y = info_ptr->y_pixels_per_unit;
- retval |= PNG_INFO_pHYs;
- }
-
- if (unit_type != NULL)
- {
- *unit_type = (int)info_ptr->phys_unit_type;
- retval |= PNG_INFO_pHYs;
-
- if (*unit_type == 1)
- {
- if (res_x != NULL) *res_x = (png_uint_32)(*res_x * .0254 + .50);
- if (res_y != NULL) *res_y = (png_uint_32)(*res_y * .0254 + .50);
- }
- }
- }
-
- return (retval);
-}
-#endif /* PNG_pHYs_SUPPORTED */
-#endif /* PNG_INCH_CONVERSIONS_SUPPORTED */
-
-/* png_get_channels really belongs in here, too, but it's been around longer */
-
-#endif /* PNG_EASY_ACCESS_SUPPORTED */
-
-
-png_byte PNGAPI
-png_get_channels(png_const_structrp png_ptr, png_const_inforp info_ptr)
-{
- if (png_ptr != NULL && info_ptr != NULL)
- return(info_ptr->channels);
-
- return (0);
-}
-
-#ifdef PNG_READ_SUPPORTED
-png_const_bytep PNGAPI
-png_get_signature(png_const_structrp png_ptr, png_const_inforp info_ptr)
-{
- if (png_ptr != NULL && info_ptr != NULL)
- return(info_ptr->signature);
-
- return (NULL);
-}
-#endif
-
-#ifdef PNG_bKGD_SUPPORTED
-png_uint_32 PNGAPI
-png_get_bKGD(png_const_structrp png_ptr, png_inforp info_ptr,
- png_color_16p *background)
-{
- if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_bKGD)
- && background != NULL)
- {
- png_debug1(1, "in %s retrieval function", "bKGD");
-
- *background = &(info_ptr->background);
- return (PNG_INFO_bKGD);
- }
-
- return (0);
-}
-#endif
-
-#ifdef PNG_cHRM_SUPPORTED
-/* The XYZ APIs were added in 1.5.5 to take advantage of the code added at the
- * same time to correct the rgb grayscale coefficient defaults obtained from the
- * cHRM chunk in 1.5.4
- */
-# ifdef PNG_FLOATING_POINT_SUPPORTED
-png_uint_32 PNGAPI
-png_get_cHRM(png_const_structrp png_ptr, png_const_inforp info_ptr,
- double *white_x, double *white_y, double *red_x, double *red_y,
- double *green_x, double *green_y, double *blue_x, double *blue_y)
-{
- /* Quiet API change: this code used to only return the end points if a cHRM
- * chunk was present, but the end points can also come from iCCP or sRGB
- * chunks, so in 1.6.0 the png_get_ APIs return the end points regardless and
- * the png_set_ APIs merely check that set end points are mutually
- * consistent.
- */
- if (png_ptr != NULL && info_ptr != NULL &&
- (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_ENDPOINTS))
- {
- png_debug1(1, "in %s retrieval function", "cHRM");
-
- if (white_x != NULL)
- *white_x = png_float(png_ptr,
- info_ptr->colorspace.end_points_xy.whitex, "cHRM white X");
- if (white_y != NULL)
- *white_y = png_float(png_ptr,
- info_ptr->colorspace.end_points_xy.whitey, "cHRM white Y");
- if (red_x != NULL)
- *red_x = png_float(png_ptr, info_ptr->colorspace.end_points_xy.redx,
- "cHRM red X");
- if (red_y != NULL)
- *red_y = png_float(png_ptr, info_ptr->colorspace.end_points_xy.redy,
- "cHRM red Y");
- if (green_x != NULL)
- *green_x = png_float(png_ptr,
- info_ptr->colorspace.end_points_xy.greenx, "cHRM green X");
- if (green_y != NULL)
- *green_y = png_float(png_ptr,
- info_ptr->colorspace.end_points_xy.greeny, "cHRM green Y");
- if (blue_x != NULL)
- *blue_x = png_float(png_ptr, info_ptr->colorspace.end_points_xy.bluex,
- "cHRM blue X");
- if (blue_y != NULL)
- *blue_y = png_float(png_ptr, info_ptr->colorspace.end_points_xy.bluey,
- "cHRM blue Y");
- return (PNG_INFO_cHRM);
- }
-
- return (0);
-}
-
-png_uint_32 PNGAPI
-png_get_cHRM_XYZ(png_const_structrp png_ptr, png_const_inforp info_ptr,
- double *red_X, double *red_Y, double *red_Z, double *green_X,
- double *green_Y, double *green_Z, double *blue_X, double *blue_Y,
- double *blue_Z)
-{
- if (png_ptr != NULL && info_ptr != NULL &&
- (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_ENDPOINTS))
- {
- png_debug1(1, "in %s retrieval function", "cHRM_XYZ(float)");
-
- if (red_X != NULL)
- *red_X = png_float(png_ptr, info_ptr->colorspace.end_points_XYZ.red_X,
- "cHRM red X");
- if (red_Y != NULL)
- *red_Y = png_float(png_ptr, info_ptr->colorspace.end_points_XYZ.red_Y,
- "cHRM red Y");
- if (red_Z != NULL)
- *red_Z = png_float(png_ptr, info_ptr->colorspace.end_points_XYZ.red_Z,
- "cHRM red Z");
- if (green_X != NULL)
- *green_X = png_float(png_ptr,
- info_ptr->colorspace.end_points_XYZ.green_X, "cHRM green X");
- if (green_Y != NULL)
- *green_Y = png_float(png_ptr,
- info_ptr->colorspace.end_points_XYZ.green_Y, "cHRM green Y");
- if (green_Z != NULL)
- *green_Z = png_float(png_ptr,
- info_ptr->colorspace.end_points_XYZ.green_Z, "cHRM green Z");
- if (blue_X != NULL)
- *blue_X = png_float(png_ptr,
- info_ptr->colorspace.end_points_XYZ.blue_X, "cHRM blue X");
- if (blue_Y != NULL)
- *blue_Y = png_float(png_ptr,
- info_ptr->colorspace.end_points_XYZ.blue_Y, "cHRM blue Y");
- if (blue_Z != NULL)
- *blue_Z = png_float(png_ptr,
- info_ptr->colorspace.end_points_XYZ.blue_Z, "cHRM blue Z");
- return (PNG_INFO_cHRM);
- }
-
- return (0);
-}
-# endif
-
-# ifdef PNG_FIXED_POINT_SUPPORTED
-png_uint_32 PNGAPI
-png_get_cHRM_XYZ_fixed(png_const_structrp png_ptr, png_const_inforp info_ptr,
- png_fixed_point *int_red_X, png_fixed_point *int_red_Y,
- png_fixed_point *int_red_Z, png_fixed_point *int_green_X,
- png_fixed_point *int_green_Y, png_fixed_point *int_green_Z,
- png_fixed_point *int_blue_X, png_fixed_point *int_blue_Y,
- png_fixed_point *int_blue_Z)
-{
- if (png_ptr != NULL && info_ptr != NULL &&
- (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_ENDPOINTS))
- {
- png_debug1(1, "in %s retrieval function", "cHRM_XYZ");
-
- if (int_red_X != NULL)
- *int_red_X = info_ptr->colorspace.end_points_XYZ.red_X;
- if (int_red_Y != NULL)
- *int_red_Y = info_ptr->colorspace.end_points_XYZ.red_Y;
- if (int_red_Z != NULL)
- *int_red_Z = info_ptr->colorspace.end_points_XYZ.red_Z;
- if (int_green_X != NULL)
- *int_green_X = info_ptr->colorspace.end_points_XYZ.green_X;
- if (int_green_Y != NULL)
- *int_green_Y = info_ptr->colorspace.end_points_XYZ.green_Y;
- if (int_green_Z != NULL)
- *int_green_Z = info_ptr->colorspace.end_points_XYZ.green_Z;
- if (int_blue_X != NULL)
- *int_blue_X = info_ptr->colorspace.end_points_XYZ.blue_X;
- if (int_blue_Y != NULL)
- *int_blue_Y = info_ptr->colorspace.end_points_XYZ.blue_Y;
- if (int_blue_Z != NULL)
- *int_blue_Z = info_ptr->colorspace.end_points_XYZ.blue_Z;
- return (PNG_INFO_cHRM);
- }
-
- return (0);
-}
-
-png_uint_32 PNGAPI
-png_get_cHRM_fixed(png_const_structrp png_ptr, png_const_inforp info_ptr,
- png_fixed_point *white_x, png_fixed_point *white_y, png_fixed_point *red_x,
- png_fixed_point *red_y, png_fixed_point *green_x, png_fixed_point *green_y,
- png_fixed_point *blue_x, png_fixed_point *blue_y)
-{
- png_debug1(1, "in %s retrieval function", "cHRM");
-
- if (png_ptr != NULL && info_ptr != NULL &&
- (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_ENDPOINTS))
- {
- if (white_x != NULL)
- *white_x = info_ptr->colorspace.end_points_xy.whitex;
- if (white_y != NULL)
- *white_y = info_ptr->colorspace.end_points_xy.whitey;
- if (red_x != NULL)
- *red_x = info_ptr->colorspace.end_points_xy.redx;
- if (red_y != NULL)
- *red_y = info_ptr->colorspace.end_points_xy.redy;
- if (green_x != NULL)
- *green_x = info_ptr->colorspace.end_points_xy.greenx;
- if (green_y != NULL)
- *green_y = info_ptr->colorspace.end_points_xy.greeny;
- if (blue_x != NULL)
- *blue_x = info_ptr->colorspace.end_points_xy.bluex;
- if (blue_y != NULL)
- *blue_y = info_ptr->colorspace.end_points_xy.bluey;
- return (PNG_INFO_cHRM);
- }
-
- return (0);
-}
-# endif
-#endif
-
-#ifdef PNG_gAMA_SUPPORTED
-# ifdef PNG_FIXED_POINT_SUPPORTED
-png_uint_32 PNGAPI
-png_get_gAMA_fixed(png_const_structrp png_ptr, png_const_inforp info_ptr,
- png_fixed_point *file_gamma)
-{
- png_debug1(1, "in %s retrieval function", "gAMA");
-
- if (png_ptr != NULL && info_ptr != NULL &&
- (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_GAMMA) &&
- file_gamma != NULL)
- {
- *file_gamma = info_ptr->colorspace.gamma;
- return (PNG_INFO_gAMA);
- }
-
- return (0);
-}
-# endif
-
-# ifdef PNG_FLOATING_POINT_SUPPORTED
-png_uint_32 PNGAPI
-png_get_gAMA(png_const_structrp png_ptr, png_const_inforp info_ptr,
- double *file_gamma)
-{
- png_debug1(1, "in %s retrieval function", "gAMA(float)");
-
- if (png_ptr != NULL && info_ptr != NULL &&
- (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_GAMMA) &&
- file_gamma != NULL)
- {
- *file_gamma = png_float(png_ptr, info_ptr->colorspace.gamma,
- "png_get_gAMA");
- return (PNG_INFO_gAMA);
- }
-
- return (0);
-}
-# endif
-#endif
-
-#ifdef PNG_sRGB_SUPPORTED
-png_uint_32 PNGAPI
-png_get_sRGB(png_const_structrp png_ptr, png_const_inforp info_ptr,
- int *file_srgb_intent)
-{
- png_debug1(1, "in %s retrieval function", "sRGB");
-
- if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_sRGB)
- && file_srgb_intent != NULL)
- {
- *file_srgb_intent = info_ptr->colorspace.rendering_intent;
- return (PNG_INFO_sRGB);
- }
-
- return (0);
-}
-#endif
-
-#ifdef PNG_iCCP_SUPPORTED
-png_uint_32 PNGAPI
-png_get_iCCP(png_const_structrp png_ptr, png_inforp info_ptr,
- png_charpp name, int *compression_type,
- png_bytepp profile, png_uint_32 *proflen)
-{
- png_debug1(1, "in %s retrieval function", "iCCP");
-
- if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_iCCP)
- && name != NULL && compression_type != NULL && profile != NULL &&
- proflen != NULL)
- {
- *name = info_ptr->iccp_name;
- *profile = info_ptr->iccp_profile;
- *proflen = png_get_uint_32(info_ptr->iccp_profile);
- /* This is somewhat irrelevant since the profile data returned has
- * actually been uncompressed.
- */
- *compression_type = PNG_COMPRESSION_TYPE_BASE;
- return (PNG_INFO_iCCP);
- }
-
- return (0);
-}
-#endif
-
-#ifdef PNG_sPLT_SUPPORTED
-int PNGAPI
-png_get_sPLT(png_const_structrp png_ptr, png_inforp info_ptr,
- png_sPLT_tpp spalettes)
-{
- if (png_ptr != NULL && info_ptr != NULL && spalettes != NULL)
- {
- *spalettes = info_ptr->splt_palettes;
- return info_ptr->splt_palettes_num;
- }
-
- return (0);
-}
-#endif
-
-#ifdef PNG_hIST_SUPPORTED
-png_uint_32 PNGAPI
-png_get_hIST(png_const_structrp png_ptr, png_inforp info_ptr,
- png_uint_16p *hist)
-{
- png_debug1(1, "in %s retrieval function", "hIST");
-
- if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_hIST)
- && hist != NULL)
- {
- *hist = info_ptr->hist;
- return (PNG_INFO_hIST);
- }
-
- return (0);
-}
-#endif
-
-png_uint_32 PNGAPI
-png_get_IHDR(png_const_structrp png_ptr, png_const_inforp info_ptr,
- png_uint_32 *width, png_uint_32 *height, int *bit_depth,
- int *color_type, int *interlace_type, int *compression_type,
- int *filter_type)
-{
- png_debug1(1, "in %s retrieval function", "IHDR");
-
- if (png_ptr == NULL || info_ptr == NULL || width == NULL ||
- height == NULL || bit_depth == NULL || color_type == NULL)
- return (0);
-
- *width = info_ptr->width;
- *height = info_ptr->height;
- *bit_depth = info_ptr->bit_depth;
- *color_type = info_ptr->color_type;
-
- if (compression_type != NULL)
- *compression_type = info_ptr->compression_type;
-
- if (filter_type != NULL)
- *filter_type = info_ptr->filter_type;
-
- if (interlace_type != NULL)
- *interlace_type = info_ptr->interlace_type;
-
- /* This is redundant if we can be sure that the info_ptr values were all
- * assigned in png_set_IHDR(). We do the check anyhow in case an
- * application has ignored our advice not to mess with the members
- * of info_ptr directly.
- */
- png_check_IHDR(png_ptr, info_ptr->width, info_ptr->height,
- info_ptr->bit_depth, info_ptr->color_type, info_ptr->interlace_type,
- info_ptr->compression_type, info_ptr->filter_type);
-
- return (1);
-}
-
-#ifdef PNG_oFFs_SUPPORTED
-png_uint_32 PNGAPI
-png_get_oFFs(png_const_structrp png_ptr, png_const_inforp info_ptr,
- png_int_32 *offset_x, png_int_32 *offset_y, int *unit_type)
-{
- png_debug1(1, "in %s retrieval function", "oFFs");
-
- if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs)
- && offset_x != NULL && offset_y != NULL && unit_type != NULL)
- {
- *offset_x = info_ptr->x_offset;
- *offset_y = info_ptr->y_offset;
- *unit_type = (int)info_ptr->offset_unit_type;
- return (PNG_INFO_oFFs);
- }
-
- return (0);
-}
-#endif
-
-#ifdef PNG_pCAL_SUPPORTED
-png_uint_32 PNGAPI
-png_get_pCAL(png_const_structrp png_ptr, png_inforp info_ptr,
- png_charp *purpose, png_int_32 *X0, png_int_32 *X1, int *type, int *nparams,
- png_charp *units, png_charpp *params)
-{
- png_debug1(1, "in %s retrieval function", "pCAL");
-
- if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pCAL)
- && purpose != NULL && X0 != NULL && X1 != NULL && type != NULL &&
- nparams != NULL && units != NULL && params != NULL)
- {
- *purpose = info_ptr->pcal_purpose;
- *X0 = info_ptr->pcal_X0;
- *X1 = info_ptr->pcal_X1;
- *type = (int)info_ptr->pcal_type;
- *nparams = (int)info_ptr->pcal_nparams;
- *units = info_ptr->pcal_units;
- *params = info_ptr->pcal_params;
- return (PNG_INFO_pCAL);
- }
-
- return (0);
-}
-#endif
-
-#ifdef PNG_sCAL_SUPPORTED
-# ifdef PNG_FIXED_POINT_SUPPORTED
-# if defined(PNG_FLOATING_ARITHMETIC_SUPPORTED) || \
- defined(PNG_FLOATING_POINT_SUPPORTED)
-png_uint_32 PNGAPI
-png_get_sCAL_fixed(png_const_structrp png_ptr, png_const_inforp info_ptr,
- int *unit, png_fixed_point *width, png_fixed_point *height)
-{
- if (png_ptr != NULL && info_ptr != NULL &&
- (info_ptr->valid & PNG_INFO_sCAL))
- {
- *unit = info_ptr->scal_unit;
- /*TODO: make this work without FP support; the API is currently eliminated
- * if neither floating point APIs nor internal floating point arithmetic
- * are enabled.
- */
- *width = png_fixed(png_ptr, atof(info_ptr->scal_s_width), "sCAL width");
- *height = png_fixed(png_ptr, atof(info_ptr->scal_s_height),
- "sCAL height");
- return (PNG_INFO_sCAL);
- }
-
- return(0);
-}
-# endif /* FLOATING_ARITHMETIC */
-# endif /* FIXED_POINT */
-# ifdef PNG_FLOATING_POINT_SUPPORTED
-png_uint_32 PNGAPI
-png_get_sCAL(png_const_structrp png_ptr, png_const_inforp info_ptr,
- int *unit, double *width, double *height)
-{
- if (png_ptr != NULL && info_ptr != NULL &&
- (info_ptr->valid & PNG_INFO_sCAL))
- {
- *unit = info_ptr->scal_unit;
- *width = atof(info_ptr->scal_s_width);
- *height = atof(info_ptr->scal_s_height);
- return (PNG_INFO_sCAL);
- }
-
- return(0);
-}
-# endif /* FLOATING POINT */
-png_uint_32 PNGAPI
-png_get_sCAL_s(png_const_structrp png_ptr, png_const_inforp info_ptr,
- int *unit, png_charpp width, png_charpp height)
-{
- if (png_ptr != NULL && info_ptr != NULL &&
- (info_ptr->valid & PNG_INFO_sCAL))
- {
- *unit = info_ptr->scal_unit;
- *width = info_ptr->scal_s_width;
- *height = info_ptr->scal_s_height;
- return (PNG_INFO_sCAL);
- }
-
- return(0);
-}
-#endif /* sCAL */
-
-#ifdef PNG_pHYs_SUPPORTED
-png_uint_32 PNGAPI
-png_get_pHYs(png_const_structrp png_ptr, png_const_inforp info_ptr,
- png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type)
-{
- png_uint_32 retval = 0;
-
- png_debug1(1, "in %s retrieval function", "pHYs");
-
- if (png_ptr != NULL && info_ptr != NULL &&
- (info_ptr->valid & PNG_INFO_pHYs))
- {
- if (res_x != NULL)
- {
- *res_x = info_ptr->x_pixels_per_unit;
- retval |= PNG_INFO_pHYs;
- }
-
- if (res_y != NULL)
- {
- *res_y = info_ptr->y_pixels_per_unit;
- retval |= PNG_INFO_pHYs;
- }
-
- if (unit_type != NULL)
- {
- *unit_type = (int)info_ptr->phys_unit_type;
- retval |= PNG_INFO_pHYs;
- }
- }
-
- return (retval);
-}
-#endif /* pHYs */
-
-png_uint_32 PNGAPI
-png_get_PLTE(png_const_structrp png_ptr, png_inforp info_ptr,
- png_colorp *palette, int *num_palette)
-{
- png_debug1(1, "in %s retrieval function", "PLTE");
-
- if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_PLTE)
- && palette != NULL)
- {
- *palette = info_ptr->palette;
- *num_palette = info_ptr->num_palette;
- png_debug1(3, "num_palette = %d", *num_palette);
- return (PNG_INFO_PLTE);
- }
-
- return (0);
-}
-
-#ifdef PNG_sBIT_SUPPORTED
-png_uint_32 PNGAPI
-png_get_sBIT(png_const_structrp png_ptr, png_inforp info_ptr,
- png_color_8p *sig_bit)
-{
- png_debug1(1, "in %s retrieval function", "sBIT");
-
- if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_sBIT)
- && sig_bit != NULL)
- {
- *sig_bit = &(info_ptr->sig_bit);
- return (PNG_INFO_sBIT);
- }
-
- return (0);
-}
-#endif
-
-#ifdef PNG_TEXT_SUPPORTED
-int PNGAPI
-png_get_text(png_const_structrp png_ptr, png_inforp info_ptr,
- png_textp *text_ptr, int *num_text)
-{
- if (png_ptr != NULL && info_ptr != NULL && info_ptr->num_text > 0)
- {
- png_debug1(1, "in 0x%lx retrieval function",
- (unsigned long)png_ptr->chunk_name);
-
- if (text_ptr != NULL)
- *text_ptr = info_ptr->text;
-
- if (num_text != NULL)
- *num_text = info_ptr->num_text;
-
- return info_ptr->num_text;
- }
-
- if (num_text != NULL)
- *num_text = 0;
-
- return(0);
-}
-#endif
-
-#ifdef PNG_tIME_SUPPORTED
-png_uint_32 PNGAPI
-png_get_tIME(png_const_structrp png_ptr, png_inforp info_ptr,
- png_timep *mod_time)
-{
- png_debug1(1, "in %s retrieval function", "tIME");
-
- if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_tIME)
- && mod_time != NULL)
- {
- *mod_time = &(info_ptr->mod_time);
- return (PNG_INFO_tIME);
- }
-
- return (0);
-}
-#endif
-
-#ifdef PNG_tRNS_SUPPORTED
-png_uint_32 PNGAPI
-png_get_tRNS(png_const_structrp png_ptr, png_inforp info_ptr,
- png_bytep *trans_alpha, int *num_trans, png_color_16p *trans_color)
-{
- png_uint_32 retval = 0;
- if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_tRNS))
- {
- png_debug1(1, "in %s retrieval function", "tRNS");
-
- if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
- {
- if (trans_alpha != NULL)
- {
- *trans_alpha = info_ptr->trans_alpha;
- retval |= PNG_INFO_tRNS;
- }
-
- if (trans_color != NULL)
- *trans_color = &(info_ptr->trans_color);
- }
-
- else /* if (info_ptr->color_type != PNG_COLOR_TYPE_PALETTE) */
- {
- if (trans_color != NULL)
- {
- *trans_color = &(info_ptr->trans_color);
- retval |= PNG_INFO_tRNS;
- }
-
- if (trans_alpha != NULL)
- *trans_alpha = NULL;
- }
-
- if (num_trans != NULL)
- {
- *num_trans = info_ptr->num_trans;
- retval |= PNG_INFO_tRNS;
- }
- }
-
- return (retval);
-}
-#endif
-
-#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
-int PNGAPI
-png_get_unknown_chunks(png_const_structrp png_ptr, png_inforp info_ptr,
- png_unknown_chunkpp unknowns)
-{
- if (png_ptr != NULL && info_ptr != NULL && unknowns != NULL)
- {
- *unknowns = info_ptr->unknown_chunks;
- return info_ptr->unknown_chunks_num;
- }
-
- return (0);
-}
-#endif
-
-#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
-png_byte PNGAPI
-png_get_rgb_to_gray_status (png_const_structrp png_ptr)
-{
- return (png_byte)(png_ptr ? png_ptr->rgb_to_gray_status : 0);
-}
-#endif
-
-#ifdef PNG_USER_CHUNKS_SUPPORTED
-png_voidp PNGAPI
-png_get_user_chunk_ptr(png_const_structrp png_ptr)
-{
- return (png_ptr ? png_ptr->user_chunk_ptr : NULL);
-}
-#endif
-
-png_size_t PNGAPI
-png_get_compression_buffer_size(png_const_structrp png_ptr)
-{
- if (png_ptr == NULL)
- return 0;
-
-# ifdef PNG_WRITE_SUPPORTED
- if (png_ptr->mode & PNG_IS_READ_STRUCT)
-# endif
- {
-# ifdef PNG_SEQUENTIAL_READ_SUPPORTED
- return png_ptr->IDAT_read_size;
-# else
- return PNG_IDAT_READ_SIZE;
-# endif
- }
-
-# ifdef PNG_WRITE_SUPPORTED
- else
- return png_ptr->zbuffer_size;
-# endif
-}
-
-#ifdef PNG_SET_USER_LIMITS_SUPPORTED
-/* These functions were added to libpng 1.2.6 and were enabled
- * by default in libpng-1.4.0 */
-png_uint_32 PNGAPI
-png_get_user_width_max (png_const_structrp png_ptr)
-{
- return (png_ptr ? png_ptr->user_width_max : 0);
-}
-
-png_uint_32 PNGAPI
-png_get_user_height_max (png_const_structrp png_ptr)
-{
- return (png_ptr ? png_ptr->user_height_max : 0);
-}
-
-/* This function was added to libpng 1.4.0 */
-png_uint_32 PNGAPI
-png_get_chunk_cache_max (png_const_structrp png_ptr)
-{
- return (png_ptr ? png_ptr->user_chunk_cache_max : 0);
-}
-
-/* This function was added to libpng 1.4.1 */
-png_alloc_size_t PNGAPI
-png_get_chunk_malloc_max (png_const_structrp png_ptr)
-{
- return (png_ptr ? png_ptr->user_chunk_malloc_max : 0);
-}
-#endif /* ?PNG_SET_USER_LIMITS_SUPPORTED */
-
-/* These functions were added to libpng 1.4.0 */
-#ifdef PNG_IO_STATE_SUPPORTED
-png_uint_32 PNGAPI
-png_get_io_state (png_const_structrp png_ptr)
-{
- return png_ptr->io_state;
-}
-
-png_uint_32 PNGAPI
-png_get_io_chunk_type (png_const_structrp png_ptr)
-{
- return png_ptr->chunk_name;
-}
-#endif /* ?PNG_IO_STATE_SUPPORTED */
-
-#ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED
-# ifdef PNG_GET_PALETTE_MAX_SUPPORTED
-int PNGAPI
-png_get_palette_max(png_const_structp png_ptr, png_const_infop info_ptr)
-{
- if (png_ptr != NULL && info_ptr != NULL)
- return png_ptr->num_palette_max;
-
- return (-1);
-}
-# endif
-#endif
-
-#endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */
+
+/* pngget.c - retrieval of values from info struct
+ *
+ * Last changed in libpng 1.6.17 [March 26, 2015]
+ * Copyright (c) 1998-2015 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ */
+
+#include "pngpriv.h"
+
+#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
+
+png_uint_32 PNGAPI
+png_get_valid(png_const_structrp png_ptr, png_const_inforp info_ptr,
+ png_uint_32 flag)
+{
+ if (png_ptr != NULL && info_ptr != NULL)
+ return(info_ptr->valid & flag);
+
+ return(0);
+}
+
+png_size_t PNGAPI
+png_get_rowbytes(png_const_structrp png_ptr, png_const_inforp info_ptr)
+{
+ if (png_ptr != NULL && info_ptr != NULL)
+ return(info_ptr->rowbytes);
+
+ return(0);
+}
+
+#ifdef PNG_INFO_IMAGE_SUPPORTED
+png_bytepp PNGAPI
+png_get_rows(png_const_structrp png_ptr, png_const_inforp info_ptr)
+{
+ if (png_ptr != NULL && info_ptr != NULL)
+ return(info_ptr->row_pointers);
+
+ return(0);
+}
+#endif
+
+#ifdef PNG_EASY_ACCESS_SUPPORTED
+/* Easy access to info, added in libpng-0.99 */
+png_uint_32 PNGAPI
+png_get_image_width(png_const_structrp png_ptr, png_const_inforp info_ptr)
+{
+ if (png_ptr != NULL && info_ptr != NULL)
+ return info_ptr->width;
+
+ return (0);
+}
+
+png_uint_32 PNGAPI
+png_get_image_height(png_const_structrp png_ptr, png_const_inforp info_ptr)
+{
+ if (png_ptr != NULL && info_ptr != NULL)
+ return info_ptr->height;
+
+ return (0);
+}
+
+png_byte PNGAPI
+png_get_bit_depth(png_const_structrp png_ptr, png_const_inforp info_ptr)
+{
+ if (png_ptr != NULL && info_ptr != NULL)
+ return info_ptr->bit_depth;
+
+ return (0);
+}
+
+png_byte PNGAPI
+png_get_color_type(png_const_structrp png_ptr, png_const_inforp info_ptr)
+{
+ if (png_ptr != NULL && info_ptr != NULL)
+ return info_ptr->color_type;
+
+ return (0);
+}
+
+png_byte PNGAPI
+png_get_filter_type(png_const_structrp png_ptr, png_const_inforp info_ptr)
+{
+ if (png_ptr != NULL && info_ptr != NULL)
+ return info_ptr->filter_type;
+
+ return (0);
+}
+
+png_byte PNGAPI
+png_get_interlace_type(png_const_structrp png_ptr, png_const_inforp info_ptr)
+{
+ if (png_ptr != NULL && info_ptr != NULL)
+ return info_ptr->interlace_type;
+
+ return (0);
+}
+
+png_byte PNGAPI
+png_get_compression_type(png_const_structrp png_ptr, png_const_inforp info_ptr)
+{
+ if (png_ptr != NULL && info_ptr != NULL)
+ return info_ptr->compression_type;
+
+ return (0);
+}
+
+png_uint_32 PNGAPI
+png_get_x_pixels_per_meter(png_const_structrp png_ptr, png_const_inforp
+ info_ptr)
+{
+#ifdef PNG_pHYs_SUPPORTED
+ if (png_ptr != NULL && info_ptr != NULL &&
+ (info_ptr->valid & PNG_INFO_pHYs) != 0)
+ {
+ png_debug1(1, "in %s retrieval function",
+ "png_get_x_pixels_per_meter");
+
+ if (info_ptr->phys_unit_type == PNG_RESOLUTION_METER)
+ return (info_ptr->x_pixels_per_unit);
+ }
+#else
+ PNG_UNUSED(png_ptr)
+ PNG_UNUSED(info_ptr)
+#endif
+
+ return (0);
+}
+
+png_uint_32 PNGAPI
+png_get_y_pixels_per_meter(png_const_structrp png_ptr, png_const_inforp
+ info_ptr)
+{
+#ifdef PNG_pHYs_SUPPORTED
+ if (png_ptr != NULL && info_ptr != NULL &&
+ (info_ptr->valid & PNG_INFO_pHYs) != 0)
+ {
+ png_debug1(1, "in %s retrieval function",
+ "png_get_y_pixels_per_meter");
+
+ if (info_ptr->phys_unit_type == PNG_RESOLUTION_METER)
+ return (info_ptr->y_pixels_per_unit);
+ }
+#else
+ PNG_UNUSED(png_ptr)
+ PNG_UNUSED(info_ptr)
+#endif
+
+ return (0);
+}
+
+png_uint_32 PNGAPI
+png_get_pixels_per_meter(png_const_structrp png_ptr, png_const_inforp info_ptr)
+{
+#ifdef PNG_pHYs_SUPPORTED
+ if (png_ptr != NULL && info_ptr != NULL &&
+ (info_ptr->valid & PNG_INFO_pHYs) != 0)
+ {
+ png_debug1(1, "in %s retrieval function", "png_get_pixels_per_meter");
+
+ if (info_ptr->phys_unit_type == PNG_RESOLUTION_METER &&
+ info_ptr->x_pixels_per_unit == info_ptr->y_pixels_per_unit)
+ return (info_ptr->x_pixels_per_unit);
+ }
+#else
+ PNG_UNUSED(png_ptr)
+ PNG_UNUSED(info_ptr)
+#endif
+
+ return (0);
+}
+
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+float PNGAPI
+png_get_pixel_aspect_ratio(png_const_structrp png_ptr, png_const_inforp
+ info_ptr)
+{
+#ifdef PNG_READ_pHYs_SUPPORTED
+ if (png_ptr != NULL && info_ptr != NULL &&
+ (info_ptr->valid & PNG_INFO_pHYs) != 0)
+ {
+ png_debug1(1, "in %s retrieval function", "png_get_aspect_ratio");
+
+ if (info_ptr->x_pixels_per_unit != 0)
+ return ((float)((float)info_ptr->y_pixels_per_unit
+ /(float)info_ptr->x_pixels_per_unit));
+ }
+#else
+ PNG_UNUSED(png_ptr)
+ PNG_UNUSED(info_ptr)
+#endif
+
+ return ((float)0.0);
+}
+#endif
+
+#ifdef PNG_FIXED_POINT_SUPPORTED
+png_fixed_point PNGAPI
+png_get_pixel_aspect_ratio_fixed(png_const_structrp png_ptr,
+ png_const_inforp info_ptr)
+{
+#ifdef PNG_READ_pHYs_SUPPORTED
+ if (png_ptr != NULL && info_ptr != NULL &&
+ (info_ptr->valid & PNG_INFO_pHYs) != 0 &&
+ info_ptr->x_pixels_per_unit > 0 && info_ptr->y_pixels_per_unit > 0 &&
+ info_ptr->x_pixels_per_unit <= PNG_UINT_31_MAX &&
+ info_ptr->y_pixels_per_unit <= PNG_UINT_31_MAX)
+ {
+ png_fixed_point res;
+
+ png_debug1(1, "in %s retrieval function", "png_get_aspect_ratio_fixed");
+
+ /* The following casts work because a PNG 4 byte integer only has a valid
+ * range of 0..2^31-1; otherwise the cast might overflow.
+ */
+ if (png_muldiv(&res, (png_int_32)info_ptr->y_pixels_per_unit, PNG_FP_1,
+ (png_int_32)info_ptr->x_pixels_per_unit) != 0)
+ return res;
+ }
+#else
+ PNG_UNUSED(png_ptr)
+ PNG_UNUSED(info_ptr)
+#endif
+
+ return 0;
+}
+#endif
+
+png_int_32 PNGAPI
+png_get_x_offset_microns(png_const_structrp png_ptr, png_const_inforp info_ptr)
+{
+#ifdef PNG_oFFs_SUPPORTED
+ if (png_ptr != NULL && info_ptr != NULL &&
+ (info_ptr->valid & PNG_INFO_oFFs) != 0)
+ {
+ png_debug1(1, "in %s retrieval function", "png_get_x_offset_microns");
+
+ if (info_ptr->offset_unit_type == PNG_OFFSET_MICROMETER)
+ return (info_ptr->x_offset);
+ }
+#else
+ PNG_UNUSED(png_ptr)
+ PNG_UNUSED(info_ptr)
+#endif
+
+ return (0);
+}
+
+png_int_32 PNGAPI
+png_get_y_offset_microns(png_const_structrp png_ptr, png_const_inforp info_ptr)
+{
+#ifdef PNG_oFFs_SUPPORTED
+ if (png_ptr != NULL && info_ptr != NULL &&
+ (info_ptr->valid & PNG_INFO_oFFs) != 0)
+ {
+ png_debug1(1, "in %s retrieval function", "png_get_y_offset_microns");
+
+ if (info_ptr->offset_unit_type == PNG_OFFSET_MICROMETER)
+ return (info_ptr->y_offset);
+ }
+#else
+ PNG_UNUSED(png_ptr)
+ PNG_UNUSED(info_ptr)
+#endif
+
+ return (0);
+}
+
+png_int_32 PNGAPI
+png_get_x_offset_pixels(png_const_structrp png_ptr, png_const_inforp info_ptr)
+{
+#ifdef PNG_oFFs_SUPPORTED
+ if (png_ptr != NULL && info_ptr != NULL &&
+ (info_ptr->valid & PNG_INFO_oFFs) != 0)
+ {
+ png_debug1(1, "in %s retrieval function", "png_get_x_offset_pixels");
+
+ if (info_ptr->offset_unit_type == PNG_OFFSET_PIXEL)
+ return (info_ptr->x_offset);
+ }
+#else
+ PNG_UNUSED(png_ptr)
+ PNG_UNUSED(info_ptr)
+#endif
+
+ return (0);
+}
+
+png_int_32 PNGAPI
+png_get_y_offset_pixels(png_const_structrp png_ptr, png_const_inforp info_ptr)
+{
+#ifdef PNG_oFFs_SUPPORTED
+ if (png_ptr != NULL && info_ptr != NULL &&
+ (info_ptr->valid & PNG_INFO_oFFs) != 0)
+ {
+ png_debug1(1, "in %s retrieval function", "png_get_y_offset_pixels");
+
+ if (info_ptr->offset_unit_type == PNG_OFFSET_PIXEL)
+ return (info_ptr->y_offset);
+ }
+#else
+ PNG_UNUSED(png_ptr)
+ PNG_UNUSED(info_ptr)
+#endif
+
+ return (0);
+}
+
+#ifdef PNG_INCH_CONVERSIONS_SUPPORTED
+static png_uint_32
+ppi_from_ppm(png_uint_32 ppm)
+{
+#if 0
+ /* The conversion is *(2.54/100), in binary (32 digits):
+ * .00000110100000001001110101001001
+ */
+ png_uint_32 t1001, t1101;
+ ppm >>= 1; /* .1 */
+ t1001 = ppm + (ppm >> 3); /* .1001 */
+ t1101 = t1001 + (ppm >> 1); /* .1101 */
+ ppm >>= 20; /* .000000000000000000001 */
+ t1101 += t1101 >> 15; /* .1101000000000001101 */
+ t1001 >>= 11; /* .000000000001001 */
+ t1001 += t1001 >> 12; /* .000000000001001000000001001 */
+ ppm += t1001; /* .000000000001001000001001001 */
+ ppm += t1101; /* .110100000001001110101001001 */
+ return (ppm + 16) >> 5;/* .00000110100000001001110101001001 */
+#else
+ /* The argument is a PNG unsigned integer, so it is not permitted
+ * to be bigger than 2^31.
+ */
+ png_fixed_point result;
+ if (ppm <= PNG_UINT_31_MAX && png_muldiv(&result, (png_int_32)ppm, 127,
+ 5000) != 0)
+ return result;
+
+ /* Overflow. */
+ return 0;
+#endif
+}
+
+png_uint_32 PNGAPI
+png_get_pixels_per_inch(png_const_structrp png_ptr, png_const_inforp info_ptr)
+{
+ return ppi_from_ppm(png_get_pixels_per_meter(png_ptr, info_ptr));
+}
+
+png_uint_32 PNGAPI
+png_get_x_pixels_per_inch(png_const_structrp png_ptr, png_const_inforp info_ptr)
+{
+ return ppi_from_ppm(png_get_x_pixels_per_meter(png_ptr, info_ptr));
+}
+
+png_uint_32 PNGAPI
+png_get_y_pixels_per_inch(png_const_structrp png_ptr, png_const_inforp info_ptr)
+{
+ return ppi_from_ppm(png_get_y_pixels_per_meter(png_ptr, info_ptr));
+}
+
+#ifdef PNG_FIXED_POINT_SUPPORTED
+static png_fixed_point
+png_fixed_inches_from_microns(png_const_structrp png_ptr, png_int_32 microns)
+{
+ /* Convert from metres * 1,000,000 to inches * 100,000, meters to
+ * inches is simply *(100/2.54), so we want *(10/2.54) == 500/127.
+ * Notice that this can overflow - a warning is output and 0 is
+ * returned.
+ */
+ return png_muldiv_warn(png_ptr, microns, 500, 127);
+}
+
+png_fixed_point PNGAPI
+png_get_x_offset_inches_fixed(png_const_structrp png_ptr,
+ png_const_inforp info_ptr)
+{
+ return png_fixed_inches_from_microns(png_ptr,
+ png_get_x_offset_microns(png_ptr, info_ptr));
+}
+#endif
+
+#ifdef PNG_FIXED_POINT_SUPPORTED
+png_fixed_point PNGAPI
+png_get_y_offset_inches_fixed(png_const_structrp png_ptr,
+ png_const_inforp info_ptr)
+{
+ return png_fixed_inches_from_microns(png_ptr,
+ png_get_y_offset_microns(png_ptr, info_ptr));
+}
+#endif
+
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+float PNGAPI
+png_get_x_offset_inches(png_const_structrp png_ptr, png_const_inforp info_ptr)
+{
+ /* To avoid the overflow do the conversion directly in floating
+ * point.
+ */
+ return (float)(png_get_x_offset_microns(png_ptr, info_ptr) * .00003937);
+}
+#endif
+
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+float PNGAPI
+png_get_y_offset_inches(png_const_structrp png_ptr, png_const_inforp info_ptr)
+{
+ /* To avoid the overflow do the conversion directly in floating
+ * point.
+ */
+ return (float)(png_get_y_offset_microns(png_ptr, info_ptr) * .00003937);
+}
+#endif
+
+#ifdef PNG_pHYs_SUPPORTED
+png_uint_32 PNGAPI
+png_get_pHYs_dpi(png_const_structrp png_ptr, png_const_inforp info_ptr,
+ png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type)
+{
+ png_uint_32 retval = 0;
+
+ if (png_ptr != NULL && info_ptr != NULL &&
+ (info_ptr->valid & PNG_INFO_pHYs) != 0)
+ {
+ png_debug1(1, "in %s retrieval function", "pHYs");
+
+ if (res_x != NULL)
+ {
+ *res_x = info_ptr->x_pixels_per_unit;
+ retval |= PNG_INFO_pHYs;
+ }
+
+ if (res_y != NULL)
+ {
+ *res_y = info_ptr->y_pixels_per_unit;
+ retval |= PNG_INFO_pHYs;
+ }
+
+ if (unit_type != NULL)
+ {
+ *unit_type = (int)info_ptr->phys_unit_type;
+ retval |= PNG_INFO_pHYs;
+
+ if (*unit_type == 1)
+ {
+ if (res_x != NULL) *res_x = (png_uint_32)(*res_x * .0254 + .50);
+ if (res_y != NULL) *res_y = (png_uint_32)(*res_y * .0254 + .50);
+ }
+ }
+ }
+
+ return (retval);
+}
+#endif /* pHYs */
+#endif /* INCH_CONVERSIONS */
+
+/* png_get_channels really belongs in here, too, but it's been around longer */
+
+#endif /* EASY_ACCESS */
+
+
+png_byte PNGAPI
+png_get_channels(png_const_structrp png_ptr, png_const_inforp info_ptr)
+{
+ if (png_ptr != NULL && info_ptr != NULL)
+ return(info_ptr->channels);
+
+ return (0);
+}
+
+#ifdef PNG_READ_SUPPORTED
+png_const_bytep PNGAPI
+png_get_signature(png_const_structrp png_ptr, png_const_inforp info_ptr)
+{
+ if (png_ptr != NULL && info_ptr != NULL)
+ return(info_ptr->signature);
+
+ return (NULL);
+}
+#endif
+
+#ifdef PNG_bKGD_SUPPORTED
+png_uint_32 PNGAPI
+png_get_bKGD(png_const_structrp png_ptr, png_inforp info_ptr,
+ png_color_16p *background)
+{
+ if (png_ptr != NULL && info_ptr != NULL &&
+ (info_ptr->valid & PNG_INFO_bKGD) != 0 &&
+ background != NULL)
+ {
+ png_debug1(1, "in %s retrieval function", "bKGD");
+
+ *background = &(info_ptr->background);
+ return (PNG_INFO_bKGD);
+ }
+
+ return (0);
+}
+#endif
+
+#ifdef PNG_cHRM_SUPPORTED
+/* The XYZ APIs were added in 1.5.5 to take advantage of the code added at the
+ * same time to correct the rgb grayscale coefficient defaults obtained from the
+ * cHRM chunk in 1.5.4
+ */
+# ifdef PNG_FLOATING_POINT_SUPPORTED
+png_uint_32 PNGAPI
+png_get_cHRM(png_const_structrp png_ptr, png_const_inforp info_ptr,
+ double *white_x, double *white_y, double *red_x, double *red_y,
+ double *green_x, double *green_y, double *blue_x, double *blue_y)
+{
+ /* Quiet API change: this code used to only return the end points if a cHRM
+ * chunk was present, but the end points can also come from iCCP or sRGB
+ * chunks, so in 1.6.0 the png_get_ APIs return the end points regardless and
+ * the png_set_ APIs merely check that set end points are mutually
+ * consistent.
+ */
+ if (png_ptr != NULL && info_ptr != NULL &&
+ (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_ENDPOINTS) != 0)
+ {
+ png_debug1(1, "in %s retrieval function", "cHRM");
+
+ if (white_x != NULL)
+ *white_x = png_float(png_ptr,
+ info_ptr->colorspace.end_points_xy.whitex, "cHRM white X");
+ if (white_y != NULL)
+ *white_y = png_float(png_ptr,
+ info_ptr->colorspace.end_points_xy.whitey, "cHRM white Y");
+ if (red_x != NULL)
+ *red_x = png_float(png_ptr, info_ptr->colorspace.end_points_xy.redx,
+ "cHRM red X");
+ if (red_y != NULL)
+ *red_y = png_float(png_ptr, info_ptr->colorspace.end_points_xy.redy,
+ "cHRM red Y");
+ if (green_x != NULL)
+ *green_x = png_float(png_ptr,
+ info_ptr->colorspace.end_points_xy.greenx, "cHRM green X");
+ if (green_y != NULL)
+ *green_y = png_float(png_ptr,
+ info_ptr->colorspace.end_points_xy.greeny, "cHRM green Y");
+ if (blue_x != NULL)
+ *blue_x = png_float(png_ptr, info_ptr->colorspace.end_points_xy.bluex,
+ "cHRM blue X");
+ if (blue_y != NULL)
+ *blue_y = png_float(png_ptr, info_ptr->colorspace.end_points_xy.bluey,
+ "cHRM blue Y");
+ return (PNG_INFO_cHRM);
+ }
+
+ return (0);
+}
+
+png_uint_32 PNGAPI
+png_get_cHRM_XYZ(png_const_structrp png_ptr, png_const_inforp info_ptr,
+ double *red_X, double *red_Y, double *red_Z, double *green_X,
+ double *green_Y, double *green_Z, double *blue_X, double *blue_Y,
+ double *blue_Z)
+{
+ if (png_ptr != NULL && info_ptr != NULL &&
+ (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_ENDPOINTS) != 0)
+ {
+ png_debug1(1, "in %s retrieval function", "cHRM_XYZ(float)");
+
+ if (red_X != NULL)
+ *red_X = png_float(png_ptr, info_ptr->colorspace.end_points_XYZ.red_X,
+ "cHRM red X");
+ if (red_Y != NULL)
+ *red_Y = png_float(png_ptr, info_ptr->colorspace.end_points_XYZ.red_Y,
+ "cHRM red Y");
+ if (red_Z != NULL)
+ *red_Z = png_float(png_ptr, info_ptr->colorspace.end_points_XYZ.red_Z,
+ "cHRM red Z");
+ if (green_X != NULL)
+ *green_X = png_float(png_ptr,
+ info_ptr->colorspace.end_points_XYZ.green_X, "cHRM green X");
+ if (green_Y != NULL)
+ *green_Y = png_float(png_ptr,
+ info_ptr->colorspace.end_points_XYZ.green_Y, "cHRM green Y");
+ if (green_Z != NULL)
+ *green_Z = png_float(png_ptr,
+ info_ptr->colorspace.end_points_XYZ.green_Z, "cHRM green Z");
+ if (blue_X != NULL)
+ *blue_X = png_float(png_ptr,
+ info_ptr->colorspace.end_points_XYZ.blue_X, "cHRM blue X");
+ if (blue_Y != NULL)
+ *blue_Y = png_float(png_ptr,
+ info_ptr->colorspace.end_points_XYZ.blue_Y, "cHRM blue Y");
+ if (blue_Z != NULL)
+ *blue_Z = png_float(png_ptr,
+ info_ptr->colorspace.end_points_XYZ.blue_Z, "cHRM blue Z");
+ return (PNG_INFO_cHRM);
+ }
+
+ return (0);
+}
+# endif
+
+# ifdef PNG_FIXED_POINT_SUPPORTED
+png_uint_32 PNGAPI
+png_get_cHRM_XYZ_fixed(png_const_structrp png_ptr, png_const_inforp info_ptr,
+ png_fixed_point *int_red_X, png_fixed_point *int_red_Y,
+ png_fixed_point *int_red_Z, png_fixed_point *int_green_X,
+ png_fixed_point *int_green_Y, png_fixed_point *int_green_Z,
+ png_fixed_point *int_blue_X, png_fixed_point *int_blue_Y,
+ png_fixed_point *int_blue_Z)
+{
+ if (png_ptr != NULL && info_ptr != NULL &&
+ (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_ENDPOINTS) != 0)
+ {
+ png_debug1(1, "in %s retrieval function", "cHRM_XYZ");
+
+ if (int_red_X != NULL)
+ *int_red_X = info_ptr->colorspace.end_points_XYZ.red_X;
+ if (int_red_Y != NULL)
+ *int_red_Y = info_ptr->colorspace.end_points_XYZ.red_Y;
+ if (int_red_Z != NULL)
+ *int_red_Z = info_ptr->colorspace.end_points_XYZ.red_Z;
+ if (int_green_X != NULL)
+ *int_green_X = info_ptr->colorspace.end_points_XYZ.green_X;
+ if (int_green_Y != NULL)
+ *int_green_Y = info_ptr->colorspace.end_points_XYZ.green_Y;
+ if (int_green_Z != NULL)
+ *int_green_Z = info_ptr->colorspace.end_points_XYZ.green_Z;
+ if (int_blue_X != NULL)
+ *int_blue_X = info_ptr->colorspace.end_points_XYZ.blue_X;
+ if (int_blue_Y != NULL)
+ *int_blue_Y = info_ptr->colorspace.end_points_XYZ.blue_Y;
+ if (int_blue_Z != NULL)
+ *int_blue_Z = info_ptr->colorspace.end_points_XYZ.blue_Z;
+ return (PNG_INFO_cHRM);
+ }
+
+ return (0);
+}
+
+png_uint_32 PNGAPI
+png_get_cHRM_fixed(png_const_structrp png_ptr, png_const_inforp info_ptr,
+ png_fixed_point *white_x, png_fixed_point *white_y, png_fixed_point *red_x,
+ png_fixed_point *red_y, png_fixed_point *green_x, png_fixed_point *green_y,
+ png_fixed_point *blue_x, png_fixed_point *blue_y)
+{
+ png_debug1(1, "in %s retrieval function", "cHRM");
+
+ if (png_ptr != NULL && info_ptr != NULL &&
+ (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_ENDPOINTS) != 0)
+ {
+ if (white_x != NULL)
+ *white_x = info_ptr->colorspace.end_points_xy.whitex;
+ if (white_y != NULL)
+ *white_y = info_ptr->colorspace.end_points_xy.whitey;
+ if (red_x != NULL)
+ *red_x = info_ptr->colorspace.end_points_xy.redx;
+ if (red_y != NULL)
+ *red_y = info_ptr->colorspace.end_points_xy.redy;
+ if (green_x != NULL)
+ *green_x = info_ptr->colorspace.end_points_xy.greenx;
+ if (green_y != NULL)
+ *green_y = info_ptr->colorspace.end_points_xy.greeny;
+ if (blue_x != NULL)
+ *blue_x = info_ptr->colorspace.end_points_xy.bluex;
+ if (blue_y != NULL)
+ *blue_y = info_ptr->colorspace.end_points_xy.bluey;
+ return (PNG_INFO_cHRM);
+ }
+
+ return (0);
+}
+# endif
+#endif
+
+#ifdef PNG_gAMA_SUPPORTED
+# ifdef PNG_FIXED_POINT_SUPPORTED
+png_uint_32 PNGAPI
+png_get_gAMA_fixed(png_const_structrp png_ptr, png_const_inforp info_ptr,
+ png_fixed_point *file_gamma)
+{
+ png_debug1(1, "in %s retrieval function", "gAMA");
+
+ if (png_ptr != NULL && info_ptr != NULL &&
+ (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_GAMMA) != 0 &&
+ file_gamma != NULL)
+ {
+ *file_gamma = info_ptr->colorspace.gamma;
+ return (PNG_INFO_gAMA);
+ }
+
+ return (0);
+}
+# endif
+
+# ifdef PNG_FLOATING_POINT_SUPPORTED
+png_uint_32 PNGAPI
+png_get_gAMA(png_const_structrp png_ptr, png_const_inforp info_ptr,
+ double *file_gamma)
+{
+ png_debug1(1, "in %s retrieval function", "gAMA(float)");
+
+ if (png_ptr != NULL && info_ptr != NULL &&
+ (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_GAMMA) != 0 &&
+ file_gamma != NULL)
+ {
+ *file_gamma = png_float(png_ptr, info_ptr->colorspace.gamma,
+ "png_get_gAMA");
+ return (PNG_INFO_gAMA);
+ }
+
+ return (0);
+}
+# endif
+#endif
+
+#ifdef PNG_sRGB_SUPPORTED
+png_uint_32 PNGAPI
+png_get_sRGB(png_const_structrp png_ptr, png_const_inforp info_ptr,
+ int *file_srgb_intent)
+{
+ png_debug1(1, "in %s retrieval function", "sRGB");
+
+ if (png_ptr != NULL && info_ptr != NULL &&
+ (info_ptr->valid & PNG_INFO_sRGB) != 0 && file_srgb_intent != NULL)
+ {
+ *file_srgb_intent = info_ptr->colorspace.rendering_intent;
+ return (PNG_INFO_sRGB);
+ }
+
+ return (0);
+}
+#endif
+
+#ifdef PNG_iCCP_SUPPORTED
+png_uint_32 PNGAPI
+png_get_iCCP(png_const_structrp png_ptr, png_inforp info_ptr,
+ png_charpp name, int *compression_type,
+ png_bytepp profile, png_uint_32 *proflen)
+{
+ png_debug1(1, "in %s retrieval function", "iCCP");
+
+ if (png_ptr != NULL && info_ptr != NULL &&
+ (info_ptr->valid & PNG_INFO_iCCP) != 0 &&
+ name != NULL && compression_type != NULL && profile != NULL &&
+ proflen != NULL)
+ {
+ *name = info_ptr->iccp_name;
+ *profile = info_ptr->iccp_profile;
+ *proflen = png_get_uint_32(info_ptr->iccp_profile);
+ /* This is somewhat irrelevant since the profile data returned has
+ * actually been uncompressed.
+ */
+ *compression_type = PNG_COMPRESSION_TYPE_BASE;
+ return (PNG_INFO_iCCP);
+ }
+
+ return (0);
+}
+#endif
+
+#ifdef PNG_sPLT_SUPPORTED
+int PNGAPI
+png_get_sPLT(png_const_structrp png_ptr, png_inforp info_ptr,
+ png_sPLT_tpp spalettes)
+{
+ if (png_ptr != NULL && info_ptr != NULL && spalettes != NULL)
+ {
+ *spalettes = info_ptr->splt_palettes;
+ return info_ptr->splt_palettes_num;
+ }
+
+ return (0);
+}
+#endif
+
+#ifdef PNG_hIST_SUPPORTED
+png_uint_32 PNGAPI
+png_get_hIST(png_const_structrp png_ptr, png_inforp info_ptr,
+ png_uint_16p *hist)
+{
+ png_debug1(1, "in %s retrieval function", "hIST");
+
+ if (png_ptr != NULL && info_ptr != NULL &&
+ (info_ptr->valid & PNG_INFO_hIST) != 0 && hist != NULL)
+ {
+ *hist = info_ptr->hist;
+ return (PNG_INFO_hIST);
+ }
+
+ return (0);
+}
+#endif
+
+png_uint_32 PNGAPI
+png_get_IHDR(png_const_structrp png_ptr, png_const_inforp info_ptr,
+ png_uint_32 *width, png_uint_32 *height, int *bit_depth,
+ int *color_type, int *interlace_type, int *compression_type,
+ int *filter_type)
+{
+ png_debug1(1, "in %s retrieval function", "IHDR");
+
+ if (png_ptr == NULL || info_ptr == NULL)
+ return (0);
+
+ if (width != NULL)
+ *width = info_ptr->width;
+
+ if (height != NULL)
+ *height = info_ptr->height;
+
+ if (bit_depth != NULL)
+ *bit_depth = info_ptr->bit_depth;
+
+ if (color_type != NULL)
+ *color_type = info_ptr->color_type;
+
+ if (compression_type != NULL)
+ *compression_type = info_ptr->compression_type;
+
+ if (filter_type != NULL)
+ *filter_type = info_ptr->filter_type;
+
+ if (interlace_type != NULL)
+ *interlace_type = info_ptr->interlace_type;
+
+ /* This is redundant if we can be sure that the info_ptr values were all
+ * assigned in png_set_IHDR(). We do the check anyhow in case an
+ * application has ignored our advice not to mess with the members
+ * of info_ptr directly.
+ */
+ png_check_IHDR(png_ptr, info_ptr->width, info_ptr->height,
+ info_ptr->bit_depth, info_ptr->color_type, info_ptr->interlace_type,
+ info_ptr->compression_type, info_ptr->filter_type);
+
+ return (1);
+}
+
+#ifdef PNG_oFFs_SUPPORTED
+png_uint_32 PNGAPI
+png_get_oFFs(png_const_structrp png_ptr, png_const_inforp info_ptr,
+ png_int_32 *offset_x, png_int_32 *offset_y, int *unit_type)
+{
+ png_debug1(1, "in %s retrieval function", "oFFs");
+
+ if (png_ptr != NULL && info_ptr != NULL &&
+ (info_ptr->valid & PNG_INFO_oFFs) != 0 &&
+ offset_x != NULL && offset_y != NULL && unit_type != NULL)
+ {
+ *offset_x = info_ptr->x_offset;
+ *offset_y = info_ptr->y_offset;
+ *unit_type = (int)info_ptr->offset_unit_type;
+ return (PNG_INFO_oFFs);
+ }
+
+ return (0);
+}
+#endif
+
+#ifdef PNG_pCAL_SUPPORTED
+png_uint_32 PNGAPI
+png_get_pCAL(png_const_structrp png_ptr, png_inforp info_ptr,
+ png_charp *purpose, png_int_32 *X0, png_int_32 *X1, int *type, int *nparams,
+ png_charp *units, png_charpp *params)
+{
+ png_debug1(1, "in %s retrieval function", "pCAL");
+
+ if (png_ptr != NULL && info_ptr != NULL &&
+ (info_ptr->valid & PNG_INFO_pCAL) != 0 &&
+ purpose != NULL && X0 != NULL && X1 != NULL && type != NULL &&
+ nparams != NULL && units != NULL && params != NULL)
+ {
+ *purpose = info_ptr->pcal_purpose;
+ *X0 = info_ptr->pcal_X0;
+ *X1 = info_ptr->pcal_X1;
+ *type = (int)info_ptr->pcal_type;
+ *nparams = (int)info_ptr->pcal_nparams;
+ *units = info_ptr->pcal_units;
+ *params = info_ptr->pcal_params;
+ return (PNG_INFO_pCAL);
+ }
+
+ return (0);
+}
+#endif
+
+#ifdef PNG_sCAL_SUPPORTED
+# ifdef PNG_FIXED_POINT_SUPPORTED
+# if defined(PNG_FLOATING_ARITHMETIC_SUPPORTED) || \
+ defined(PNG_FLOATING_POINT_SUPPORTED)
+png_uint_32 PNGAPI
+png_get_sCAL_fixed(png_const_structrp png_ptr, png_const_inforp info_ptr,
+ int *unit, png_fixed_point *width, png_fixed_point *height)
+{
+ if (png_ptr != NULL && info_ptr != NULL &&
+ (info_ptr->valid & PNG_INFO_sCAL) != 0)
+ {
+ *unit = info_ptr->scal_unit;
+ /*TODO: make this work without FP support; the API is currently eliminated
+ * if neither floating point APIs nor internal floating point arithmetic
+ * are enabled.
+ */
+ *width = png_fixed(png_ptr, atof(info_ptr->scal_s_width), "sCAL width");
+ *height = png_fixed(png_ptr, atof(info_ptr->scal_s_height),
+ "sCAL height");
+ return (PNG_INFO_sCAL);
+ }
+
+ return(0);
+}
+# endif /* FLOATING_ARITHMETIC */
+# endif /* FIXED_POINT */
+# ifdef PNG_FLOATING_POINT_SUPPORTED
+png_uint_32 PNGAPI
+png_get_sCAL(png_const_structrp png_ptr, png_const_inforp info_ptr,
+ int *unit, double *width, double *height)
+{
+ if (png_ptr != NULL && info_ptr != NULL &&
+ (info_ptr->valid & PNG_INFO_sCAL) != 0)
+ {
+ *unit = info_ptr->scal_unit;
+ *width = atof(info_ptr->scal_s_width);
+ *height = atof(info_ptr->scal_s_height);
+ return (PNG_INFO_sCAL);
+ }
+
+ return(0);
+}
+# endif /* FLOATING POINT */
+png_uint_32 PNGAPI
+png_get_sCAL_s(png_const_structrp png_ptr, png_const_inforp info_ptr,
+ int *unit, png_charpp width, png_charpp height)
+{
+ if (png_ptr != NULL && info_ptr != NULL &&
+ (info_ptr->valid & PNG_INFO_sCAL) != 0)
+ {
+ *unit = info_ptr->scal_unit;
+ *width = info_ptr->scal_s_width;
+ *height = info_ptr->scal_s_height;
+ return (PNG_INFO_sCAL);
+ }
+
+ return(0);
+}
+#endif /* sCAL */
+
+#ifdef PNG_pHYs_SUPPORTED
+png_uint_32 PNGAPI
+png_get_pHYs(png_const_structrp png_ptr, png_const_inforp info_ptr,
+ png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type)
+{
+ png_uint_32 retval = 0;
+
+ png_debug1(1, "in %s retrieval function", "pHYs");
+
+ if (png_ptr != NULL && info_ptr != NULL &&
+ (info_ptr->valid & PNG_INFO_pHYs) != 0)
+ {
+ if (res_x != NULL)
+ {
+ *res_x = info_ptr->x_pixels_per_unit;
+ retval |= PNG_INFO_pHYs;
+ }
+
+ if (res_y != NULL)
+ {
+ *res_y = info_ptr->y_pixels_per_unit;
+ retval |= PNG_INFO_pHYs;
+ }
+
+ if (unit_type != NULL)
+ {
+ *unit_type = (int)info_ptr->phys_unit_type;
+ retval |= PNG_INFO_pHYs;
+ }
+ }
+
+ return (retval);
+}
+#endif /* pHYs */
+
+png_uint_32 PNGAPI
+png_get_PLTE(png_const_structrp png_ptr, png_inforp info_ptr,
+ png_colorp *palette, int *num_palette)
+{
+ png_debug1(1, "in %s retrieval function", "PLTE");
+
+ if (png_ptr != NULL && info_ptr != NULL &&
+ (info_ptr->valid & PNG_INFO_PLTE) != 0 && palette != NULL)
+ {
+ *palette = info_ptr->palette;
+ *num_palette = info_ptr->num_palette;
+ png_debug1(3, "num_palette = %d", *num_palette);
+ return (PNG_INFO_PLTE);
+ }
+
+ return (0);
+}
+
+#ifdef PNG_sBIT_SUPPORTED
+png_uint_32 PNGAPI
+png_get_sBIT(png_const_structrp png_ptr, png_inforp info_ptr,
+ png_color_8p *sig_bit)
+{
+ png_debug1(1, "in %s retrieval function", "sBIT");
+
+ if (png_ptr != NULL && info_ptr != NULL &&
+ (info_ptr->valid & PNG_INFO_sBIT) != 0 && sig_bit != NULL)
+ {
+ *sig_bit = &(info_ptr->sig_bit);
+ return (PNG_INFO_sBIT);
+ }
+
+ return (0);
+}
+#endif
+
+#ifdef PNG_TEXT_SUPPORTED
+int PNGAPI
+png_get_text(png_const_structrp png_ptr, png_inforp info_ptr,
+ png_textp *text_ptr, int *num_text)
+{
+ if (png_ptr != NULL && info_ptr != NULL && info_ptr->num_text > 0)
+ {
+ png_debug1(1, "in 0x%lx retrieval function",
+ (unsigned long)png_ptr->chunk_name);
+
+ if (text_ptr != NULL)
+ *text_ptr = info_ptr->text;
+
+ if (num_text != NULL)
+ *num_text = info_ptr->num_text;
+
+ return info_ptr->num_text;
+ }
+
+ if (num_text != NULL)
+ *num_text = 0;
+
+ return(0);
+}
+#endif
+
+#ifdef PNG_tIME_SUPPORTED
+png_uint_32 PNGAPI
+png_get_tIME(png_const_structrp png_ptr, png_inforp info_ptr,
+ png_timep *mod_time)
+{
+ png_debug1(1, "in %s retrieval function", "tIME");
+
+ if (png_ptr != NULL && info_ptr != NULL &&
+ (info_ptr->valid & PNG_INFO_tIME) != 0 && mod_time != NULL)
+ {
+ *mod_time = &(info_ptr->mod_time);
+ return (PNG_INFO_tIME);
+ }
+
+ return (0);
+}
+#endif
+
+#ifdef PNG_tRNS_SUPPORTED
+png_uint_32 PNGAPI
+png_get_tRNS(png_const_structrp png_ptr, png_inforp info_ptr,
+ png_bytep *trans_alpha, int *num_trans, png_color_16p *trans_color)
+{
+ png_uint_32 retval = 0;
+ if (png_ptr != NULL && info_ptr != NULL &&
+ (info_ptr->valid & PNG_INFO_tRNS) != 0)
+ {
+ png_debug1(1, "in %s retrieval function", "tRNS");
+
+ if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+ {
+ if (trans_alpha != NULL)
+ {
+ *trans_alpha = info_ptr->trans_alpha;
+ retval |= PNG_INFO_tRNS;
+ }
+
+ if (trans_color != NULL)
+ *trans_color = &(info_ptr->trans_color);
+ }
+
+ else /* if (info_ptr->color_type != PNG_COLOR_TYPE_PALETTE) */
+ {
+ if (trans_color != NULL)
+ {
+ *trans_color = &(info_ptr->trans_color);
+ retval |= PNG_INFO_tRNS;
+ }
+
+ if (trans_alpha != NULL)
+ *trans_alpha = NULL;
+ }
+
+ if (num_trans != NULL)
+ {
+ *num_trans = info_ptr->num_trans;
+ retval |= PNG_INFO_tRNS;
+ }
+ }
+
+ return (retval);
+}
+#endif
+
+#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
+int PNGAPI
+png_get_unknown_chunks(png_const_structrp png_ptr, png_inforp info_ptr,
+ png_unknown_chunkpp unknowns)
+{
+ if (png_ptr != NULL && info_ptr != NULL && unknowns != NULL)
+ {
+ *unknowns = info_ptr->unknown_chunks;
+ return info_ptr->unknown_chunks_num;
+ }
+
+ return (0);
+}
+#endif
+
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+png_byte PNGAPI
+png_get_rgb_to_gray_status (png_const_structrp png_ptr)
+{
+ return (png_byte)(png_ptr ? png_ptr->rgb_to_gray_status : 0);
+}
+#endif
+
+#ifdef PNG_USER_CHUNKS_SUPPORTED
+png_voidp PNGAPI
+png_get_user_chunk_ptr(png_const_structrp png_ptr)
+{
+ return (png_ptr ? png_ptr->user_chunk_ptr : NULL);
+}
+#endif
+
+png_size_t PNGAPI
+png_get_compression_buffer_size(png_const_structrp png_ptr)
+{
+ if (png_ptr == NULL)
+ return 0;
+
+#ifdef PNG_WRITE_SUPPORTED
+ if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0)
+#endif
+ {
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+ return png_ptr->IDAT_read_size;
+#else
+ return PNG_IDAT_READ_SIZE;
+#endif
+ }
+
+#ifdef PNG_WRITE_SUPPORTED
+ else
+ return png_ptr->zbuffer_size;
+#endif
+}
+
+#ifdef PNG_SET_USER_LIMITS_SUPPORTED
+/* These functions were added to libpng 1.2.6 and were enabled
+ * by default in libpng-1.4.0 */
+png_uint_32 PNGAPI
+png_get_user_width_max (png_const_structrp png_ptr)
+{
+ return (png_ptr ? png_ptr->user_width_max : 0);
+}
+
+png_uint_32 PNGAPI
+png_get_user_height_max (png_const_structrp png_ptr)
+{
+ return (png_ptr ? png_ptr->user_height_max : 0);
+}
+
+/* This function was added to libpng 1.4.0 */
+png_uint_32 PNGAPI
+png_get_chunk_cache_max (png_const_structrp png_ptr)
+{
+ return (png_ptr ? png_ptr->user_chunk_cache_max : 0);
+}
+
+/* This function was added to libpng 1.4.1 */
+png_alloc_size_t PNGAPI
+png_get_chunk_malloc_max (png_const_structrp png_ptr)
+{
+ return (png_ptr ? png_ptr->user_chunk_malloc_max : 0);
+}
+#endif /* SET_USER_LIMITS */
+
+/* These functions were added to libpng 1.4.0 */
+#ifdef PNG_IO_STATE_SUPPORTED
+png_uint_32 PNGAPI
+png_get_io_state (png_const_structrp png_ptr)
+{
+ return png_ptr->io_state;
+}
+
+png_uint_32 PNGAPI
+png_get_io_chunk_type (png_const_structrp png_ptr)
+{
+ return png_ptr->chunk_name;
+}
+#endif /* IO_STATE */
+
+#ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED
+# ifdef PNG_GET_PALETTE_MAX_SUPPORTED
+int PNGAPI
+png_get_palette_max(png_const_structp png_ptr, png_const_infop info_ptr)
+{
+ if (png_ptr != NULL && info_ptr != NULL)
+ return png_ptr->num_palette_max;
+
+ return (-1);
+}
+# endif
+#endif
+
+#endif /* READ || WRITE */
diff --git a/third_party/lpng_v163/pnginfo.h b/third_party/libpng/pnginfo.h
similarity index 98%
rename from third_party/lpng_v163/pnginfo.h
rename to third_party/libpng/pnginfo.h
index 683b7ea..4bd264b 100644
--- a/third_party/lpng_v163/pnginfo.h
+++ b/third_party/libpng/pnginfo.h
@@ -1,260 +1,259 @@
-
-/* pnginfo.h - header file for PNG reference library
- *
- * Copyright (c) 1998-2013 Glenn Randers-Pehrson
- * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
- * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
- *
- * Last changed in libpng 1.6.1 [March 28, 2013]
- *
- * This code is released under the libpng license.
- * For conditions of distribution and use, see the disclaimer
- * and license in png.h
- */
-
- /* png_info is a structure that holds the information in a PNG file so
- * that the application can find out the characteristics of the image.
- * If you are reading the file, this structure will tell you what is
- * in the PNG file. If you are writing the file, fill in the information
- * you want to put into the PNG file, using png_set_*() functions, then
- * call png_write_info().
- *
- * The names chosen should be very close to the PNG specification, so
- * consult that document for information about the meaning of each field.
- *
- * With libpng < 0.95, it was only possible to directly set and read the
- * the values in the png_info_struct, which meant that the contents and
- * order of the values had to remain fixed. With libpng 0.95 and later,
- * however, there are now functions that abstract the contents of
- * png_info_struct from the application, so this makes it easier to use
- * libpng with dynamic libraries, and even makes it possible to use
- * libraries that don't have all of the libpng ancillary chunk-handing
- * functionality. In libpng-1.5.0 this was moved into a separate private
- * file that is not visible to applications.
- *
- * The following members may have allocated storage attached that should be
- * cleaned up before the structure is discarded: palette, trans, text,
- * pcal_purpose, pcal_units, pcal_params, hist, iccp_name, iccp_profile,
- * splt_palettes, scal_unit, row_pointers, and unknowns. By default, these
- * are automatically freed when the info structure is deallocated, if they were
- * allocated internally by libpng. This behavior can be changed by means
- * of the png_data_freer() function.
- *
- * More allocation details: all the chunk-reading functions that
- * change these members go through the corresponding png_set_*
- * functions. A function to clear these members is available: see
- * png_free_data(). The png_set_* functions do not depend on being
- * able to point info structure members to any of the storage they are
- * passed (they make their own copies), EXCEPT that the png_set_text
- * functions use the same storage passed to them in the text_ptr or
- * itxt_ptr structure argument, and the png_set_rows and png_set_unknowns
- * functions do not make their own copies.
- */
-#ifndef PNGINFO_H
-#define PNGINFO_H
-
-struct png_info_def
-{
- /* The following are necessary for every PNG file */
- png_uint_32 width; /* width of image in pixels (from IHDR) */
- png_uint_32 height; /* height of image in pixels (from IHDR) */
- png_uint_32 valid; /* valid chunk data (see PNG_INFO_ below) */
- png_size_t rowbytes; /* bytes needed to hold an untransformed row */
- png_colorp palette; /* array of color values (valid & PNG_INFO_PLTE) */
- png_uint_16 num_palette; /* number of color entries in "palette" (PLTE) */
- png_uint_16 num_trans; /* number of transparent palette color (tRNS) */
- png_byte bit_depth; /* 1, 2, 4, 8, or 16 bits/channel (from IHDR) */
- png_byte color_type; /* see PNG_COLOR_TYPE_ below (from IHDR) */
- /* The following three should have been named *_method not *_type */
- png_byte compression_type; /* must be PNG_COMPRESSION_TYPE_BASE (IHDR) */
- png_byte filter_type; /* must be PNG_FILTER_TYPE_BASE (from IHDR) */
- png_byte interlace_type; /* One of PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */
-
- /* The following are set by png_set_IHDR, called from the application on
- * write, but the are never actually used by the write code.
- */
- png_byte channels; /* number of data channels per pixel (1, 2, 3, 4) */
- png_byte pixel_depth; /* number of bits per pixel */
- png_byte spare_byte; /* to align the data, and for future use */
-
-#ifdef PNG_READ_SUPPORTED
- /* This is never set during write */
- png_byte signature[8]; /* magic bytes read by libpng from start of file */
-#endif
-
- /* The rest of the data is optional. If you are reading, check the
- * valid field to see if the information in these are valid. If you
- * are writing, set the valid field to those chunks you want written,
- * and initialize the appropriate fields below.
- */
-
-#if defined(PNG_COLORSPACE_SUPPORTED) || defined(PNG_GAMMA_SUPPORTED)
- /* png_colorspace only contains 'flags' if neither GAMMA or COLORSPACE are
- * defined. When COLORSPACE is switched on all the colorspace-defining
- * chunks should be enabled, when GAMMA is switched on all the gamma-defining
- * chunks should be enabled. If this is not done it becomes possible to read
- * inconsistent PNG files and assign a probably incorrect interpretation to
- * the information. (In other words, by carefully choosing which chunks to
- * recognize the system configuration can select an interpretation for PNG
- * files containing ambiguous data and this will result in inconsistent
- * behavior between different libpng builds!)
- */
- png_colorspace colorspace;
-#endif
-
-#ifdef PNG_iCCP_SUPPORTED
- /* iCCP chunk data. */
- png_charp iccp_name; /* profile name */
- png_bytep iccp_profile; /* International Color Consortium profile data */
- png_uint_32 iccp_proflen; /* ICC profile data length */
-#endif
-
-#ifdef PNG_TEXT_SUPPORTED
- /* The tEXt, and zTXt chunks contain human-readable textual data in
- * uncompressed, compressed, and optionally compressed forms, respectively.
- * The data in "text" is an array of pointers to uncompressed,
- * null-terminated C strings. Each chunk has a keyword that describes the
- * textual data contained in that chunk. Keywords are not required to be
- * unique, and the text string may be empty. Any number of text chunks may
- * be in an image.
- */
- int num_text; /* number of comments read or comments to write */
- int max_text; /* current size of text array */
- png_textp text; /* array of comments read or comments to write */
-#endif /* PNG_TEXT_SUPPORTED */
-
-#ifdef PNG_tIME_SUPPORTED
- /* The tIME chunk holds the last time the displayed image data was
- * modified. See the png_time struct for the contents of this struct.
- */
- png_time mod_time;
-#endif
-
-#ifdef PNG_sBIT_SUPPORTED
- /* The sBIT chunk specifies the number of significant high-order bits
- * in the pixel data. Values are in the range [1, bit_depth], and are
- * only specified for the channels in the pixel data. The contents of
- * the low-order bits is not specified. Data is valid if
- * (valid & PNG_INFO_sBIT) is non-zero.
- */
- png_color_8 sig_bit; /* significant bits in color channels */
-#endif
-
-#if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_EXPAND_SUPPORTED) || \
-defined(PNG_READ_BACKGROUND_SUPPORTED)
- /* The tRNS chunk supplies transparency data for paletted images and
- * other image types that don't need a full alpha channel. There are
- * "num_trans" transparency values for a paletted image, stored in the
- * same order as the palette colors, starting from index 0. Values
- * for the data are in the range [0, 255], ranging from fully transparent
- * to fully opaque, respectively. For non-paletted images, there is a
- * single color specified that should be treated as fully transparent.
- * Data is valid if (valid & PNG_INFO_tRNS) is non-zero.
- */
- png_bytep trans_alpha; /* alpha values for paletted image */
- png_color_16 trans_color; /* transparent color for non-palette image */
-#endif
-
-#if defined(PNG_bKGD_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
- /* The bKGD chunk gives the suggested image background color if the
- * display program does not have its own background color and the image
- * is needs to composited onto a background before display. The colors
- * in "background" are normally in the same color space/depth as the
- * pixel data. Data is valid if (valid & PNG_INFO_bKGD) is non-zero.
- */
- png_color_16 background;
-#endif
-
-#ifdef PNG_oFFs_SUPPORTED
- /* The oFFs chunk gives the offset in "offset_unit_type" units rightwards
- * and downwards from the top-left corner of the display, page, or other
- * application-specific co-ordinate space. See the PNG_OFFSET_ defines
- * below for the unit types. Valid if (valid & PNG_INFO_oFFs) non-zero.
- */
- png_int_32 x_offset; /* x offset on page */
- png_int_32 y_offset; /* y offset on page */
- png_byte offset_unit_type; /* offset units type */
-#endif
-
-#ifdef PNG_pHYs_SUPPORTED
- /* The pHYs chunk gives the physical pixel density of the image for
- * display or printing in "phys_unit_type" units (see PNG_RESOLUTION_
- * defines below). Data is valid if (valid & PNG_INFO_pHYs) is non-zero.
- */
- png_uint_32 x_pixels_per_unit; /* horizontal pixel density */
- png_uint_32 y_pixels_per_unit; /* vertical pixel density */
- png_byte phys_unit_type; /* resolution type (see PNG_RESOLUTION_ below) */
-#endif
-
-#ifdef PNG_hIST_SUPPORTED
- /* The hIST chunk contains the relative frequency or importance of the
- * various palette entries, so that a viewer can intelligently select a
- * reduced-color palette, if required. Data is an array of "num_palette"
- * values in the range [0,65535]. Data valid if (valid & PNG_INFO_hIST)
- * is non-zero.
- */
- png_uint_16p hist;
-#endif
-
-#ifdef PNG_pCAL_SUPPORTED
- /* The pCAL chunk describes a transformation between the stored pixel
- * values and original physical data values used to create the image.
- * The integer range [0, 2^bit_depth - 1] maps to the floating-point
- * range given by [pcal_X0, pcal_X1], and are further transformed by a
- * (possibly non-linear) transformation function given by "pcal_type"
- * and "pcal_params" into "pcal_units". Please see the PNG_EQUATION_
- * defines below, and the PNG-Group's PNG extensions document for a
- * complete description of the transformations and how they should be
- * implemented, and for a description of the ASCII parameter strings.
- * Data values are valid if (valid & PNG_INFO_pCAL) non-zero.
- */
- png_charp pcal_purpose; /* pCAL chunk description string */
- png_int_32 pcal_X0; /* minimum value */
- png_int_32 pcal_X1; /* maximum value */
- png_charp pcal_units; /* Latin-1 string giving physical units */
- png_charpp pcal_params; /* ASCII strings containing parameter values */
- png_byte pcal_type; /* equation type (see PNG_EQUATION_ below) */
- png_byte pcal_nparams; /* number of parameters given in pcal_params */
-#endif
-
-/* New members added in libpng-1.0.6 */
- png_uint_32 free_me; /* flags items libpng is responsible for freeing */
-
-#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
- /* Storage for unknown chunks that the library doesn't recognize. */
- png_unknown_chunkp unknown_chunks;
-
- /* The type of this field is limited by the type of
- * png_struct::user_chunk_cache_max, else overflow can occur.
- */
- int unknown_chunks_num;
-#endif
-
-#ifdef PNG_sPLT_SUPPORTED
- /* Data on sPLT chunks (there may be more than one). */
- png_sPLT_tp splt_palettes;
- int splt_palettes_num; /* Match type returned by png_get API */
-#endif
-
-#ifdef PNG_sCAL_SUPPORTED
- /* The sCAL chunk describes the actual physical dimensions of the
- * subject matter of the graphic. The chunk contains a unit specification
- * a byte value, and two ASCII strings representing floating-point
- * values. The values are width and height corresponsing to one pixel
- * in the image. Data values are valid if (valid & PNG_INFO_sCAL) is
- * non-zero.
- */
- png_byte scal_unit; /* unit of physical scale */
- png_charp scal_s_width; /* string containing height */
- png_charp scal_s_height; /* string containing width */
-#endif
-
-#ifdef PNG_INFO_IMAGE_SUPPORTED
- /* Memory has been allocated if (valid & PNG_ALLOCATED_INFO_ROWS)
- non-zero */
- /* Data valid if (valid & PNG_INFO_IDAT) non-zero */
- png_bytepp row_pointers; /* the image bits */
-#endif
-
-};
-#endif /* PNGINFO_H */
+
+/* pnginfo.h - header file for PNG reference library
+ *
+ * Last changed in libpng 1.6.1 [March 28, 2013]
+ * Copyright (c) 1998-2013 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+
+ /* png_info is a structure that holds the information in a PNG file so
+ * that the application can find out the characteristics of the image.
+ * If you are reading the file, this structure will tell you what is
+ * in the PNG file. If you are writing the file, fill in the information
+ * you want to put into the PNG file, using png_set_*() functions, then
+ * call png_write_info().
+ *
+ * The names chosen should be very close to the PNG specification, so
+ * consult that document for information about the meaning of each field.
+ *
+ * With libpng < 0.95, it was only possible to directly set and read the
+ * the values in the png_info_struct, which meant that the contents and
+ * order of the values had to remain fixed. With libpng 0.95 and later,
+ * however, there are now functions that abstract the contents of
+ * png_info_struct from the application, so this makes it easier to use
+ * libpng with dynamic libraries, and even makes it possible to use
+ * libraries that don't have all of the libpng ancillary chunk-handing
+ * functionality. In libpng-1.5.0 this was moved into a separate private
+ * file that is not visible to applications.
+ *
+ * The following members may have allocated storage attached that should be
+ * cleaned up before the structure is discarded: palette, trans, text,
+ * pcal_purpose, pcal_units, pcal_params, hist, iccp_name, iccp_profile,
+ * splt_palettes, scal_unit, row_pointers, and unknowns. By default, these
+ * are automatically freed when the info structure is deallocated, if they were
+ * allocated internally by libpng. This behavior can be changed by means
+ * of the png_data_freer() function.
+ *
+ * More allocation details: all the chunk-reading functions that
+ * change these members go through the corresponding png_set_*
+ * functions. A function to clear these members is available: see
+ * png_free_data(). The png_set_* functions do not depend on being
+ * able to point info structure members to any of the storage they are
+ * passed (they make their own copies), EXCEPT that the png_set_text
+ * functions use the same storage passed to them in the text_ptr or
+ * itxt_ptr structure argument, and the png_set_rows and png_set_unknowns
+ * functions do not make their own copies.
+ */
+#ifndef PNGINFO_H
+#define PNGINFO_H
+
+struct png_info_def
+{
+ /* The following are necessary for every PNG file */
+ png_uint_32 width; /* width of image in pixels (from IHDR) */
+ png_uint_32 height; /* height of image in pixels (from IHDR) */
+ png_uint_32 valid; /* valid chunk data (see PNG_INFO_ below) */
+ png_size_t rowbytes; /* bytes needed to hold an untransformed row */
+ png_colorp palette; /* array of color values (valid & PNG_INFO_PLTE) */
+ png_uint_16 num_palette; /* number of color entries in "palette" (PLTE) */
+ png_uint_16 num_trans; /* number of transparent palette color (tRNS) */
+ png_byte bit_depth; /* 1, 2, 4, 8, or 16 bits/channel (from IHDR) */
+ png_byte color_type; /* see PNG_COLOR_TYPE_ below (from IHDR) */
+ /* The following three should have been named *_method not *_type */
+ png_byte compression_type; /* must be PNG_COMPRESSION_TYPE_BASE (IHDR) */
+ png_byte filter_type; /* must be PNG_FILTER_TYPE_BASE (from IHDR) */
+ png_byte interlace_type; /* One of PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */
+
+ /* The following are set by png_set_IHDR, called from the application on
+ * write, but the are never actually used by the write code.
+ */
+ png_byte channels; /* number of data channels per pixel (1, 2, 3, 4) */
+ png_byte pixel_depth; /* number of bits per pixel */
+ png_byte spare_byte; /* to align the data, and for future use */
+
+#ifdef PNG_READ_SUPPORTED
+ /* This is never set during write */
+ png_byte signature[8]; /* magic bytes read by libpng from start of file */
+#endif
+
+ /* The rest of the data is optional. If you are reading, check the
+ * valid field to see if the information in these are valid. If you
+ * are writing, set the valid field to those chunks you want written,
+ * and initialize the appropriate fields below.
+ */
+
+#if defined(PNG_COLORSPACE_SUPPORTED) || defined(PNG_GAMMA_SUPPORTED)
+ /* png_colorspace only contains 'flags' if neither GAMMA or COLORSPACE are
+ * defined. When COLORSPACE is switched on all the colorspace-defining
+ * chunks should be enabled, when GAMMA is switched on all the gamma-defining
+ * chunks should be enabled. If this is not done it becomes possible to read
+ * inconsistent PNG files and assign a probably incorrect interpretation to
+ * the information. (In other words, by carefully choosing which chunks to
+ * recognize the system configuration can select an interpretation for PNG
+ * files containing ambiguous data and this will result in inconsistent
+ * behavior between different libpng builds!)
+ */
+ png_colorspace colorspace;
+#endif
+
+#ifdef PNG_iCCP_SUPPORTED
+ /* iCCP chunk data. */
+ png_charp iccp_name; /* profile name */
+ png_bytep iccp_profile; /* International Color Consortium profile data */
+ png_uint_32 iccp_proflen; /* ICC profile data length */
+#endif
+
+#ifdef PNG_TEXT_SUPPORTED
+ /* The tEXt, and zTXt chunks contain human-readable textual data in
+ * uncompressed, compressed, and optionally compressed forms, respectively.
+ * The data in "text" is an array of pointers to uncompressed,
+ * null-terminated C strings. Each chunk has a keyword that describes the
+ * textual data contained in that chunk. Keywords are not required to be
+ * unique, and the text string may be empty. Any number of text chunks may
+ * be in an image.
+ */
+ int num_text; /* number of comments read or comments to write */
+ int max_text; /* current size of text array */
+ png_textp text; /* array of comments read or comments to write */
+#endif /* TEXT */
+
+#ifdef PNG_tIME_SUPPORTED
+ /* The tIME chunk holds the last time the displayed image data was
+ * modified. See the png_time struct for the contents of this struct.
+ */
+ png_time mod_time;
+#endif
+
+#ifdef PNG_sBIT_SUPPORTED
+ /* The sBIT chunk specifies the number of significant high-order bits
+ * in the pixel data. Values are in the range [1, bit_depth], and are
+ * only specified for the channels in the pixel data. The contents of
+ * the low-order bits is not specified. Data is valid if
+ * (valid & PNG_INFO_sBIT) is non-zero.
+ */
+ png_color_8 sig_bit; /* significant bits in color channels */
+#endif
+
+#if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_EXPAND_SUPPORTED) || \
+defined(PNG_READ_BACKGROUND_SUPPORTED)
+ /* The tRNS chunk supplies transparency data for paletted images and
+ * other image types that don't need a full alpha channel. There are
+ * "num_trans" transparency values for a paletted image, stored in the
+ * same order as the palette colors, starting from index 0. Values
+ * for the data are in the range [0, 255], ranging from fully transparent
+ * to fully opaque, respectively. For non-paletted images, there is a
+ * single color specified that should be treated as fully transparent.
+ * Data is valid if (valid & PNG_INFO_tRNS) is non-zero.
+ */
+ png_bytep trans_alpha; /* alpha values for paletted image */
+ png_color_16 trans_color; /* transparent color for non-palette image */
+#endif
+
+#if defined(PNG_bKGD_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
+ /* The bKGD chunk gives the suggested image background color if the
+ * display program does not have its own background color and the image
+ * is needs to composited onto a background before display. The colors
+ * in "background" are normally in the same color space/depth as the
+ * pixel data. Data is valid if (valid & PNG_INFO_bKGD) is non-zero.
+ */
+ png_color_16 background;
+#endif
+
+#ifdef PNG_oFFs_SUPPORTED
+ /* The oFFs chunk gives the offset in "offset_unit_type" units rightwards
+ * and downwards from the top-left corner of the display, page, or other
+ * application-specific co-ordinate space. See the PNG_OFFSET_ defines
+ * below for the unit types. Valid if (valid & PNG_INFO_oFFs) non-zero.
+ */
+ png_int_32 x_offset; /* x offset on page */
+ png_int_32 y_offset; /* y offset on page */
+ png_byte offset_unit_type; /* offset units type */
+#endif
+
+#ifdef PNG_pHYs_SUPPORTED
+ /* The pHYs chunk gives the physical pixel density of the image for
+ * display or printing in "phys_unit_type" units (see PNG_RESOLUTION_
+ * defines below). Data is valid if (valid & PNG_INFO_pHYs) is non-zero.
+ */
+ png_uint_32 x_pixels_per_unit; /* horizontal pixel density */
+ png_uint_32 y_pixels_per_unit; /* vertical pixel density */
+ png_byte phys_unit_type; /* resolution type (see PNG_RESOLUTION_ below) */
+#endif
+
+#ifdef PNG_hIST_SUPPORTED
+ /* The hIST chunk contains the relative frequency or importance of the
+ * various palette entries, so that a viewer can intelligently select a
+ * reduced-color palette, if required. Data is an array of "num_palette"
+ * values in the range [0,65535]. Data valid if (valid & PNG_INFO_hIST)
+ * is non-zero.
+ */
+ png_uint_16p hist;
+#endif
+
+#ifdef PNG_pCAL_SUPPORTED
+ /* The pCAL chunk describes a transformation between the stored pixel
+ * values and original physical data values used to create the image.
+ * The integer range [0, 2^bit_depth - 1] maps to the floating-point
+ * range given by [pcal_X0, pcal_X1], and are further transformed by a
+ * (possibly non-linear) transformation function given by "pcal_type"
+ * and "pcal_params" into "pcal_units". Please see the PNG_EQUATION_
+ * defines below, and the PNG-Group's PNG extensions document for a
+ * complete description of the transformations and how they should be
+ * implemented, and for a description of the ASCII parameter strings.
+ * Data values are valid if (valid & PNG_INFO_pCAL) non-zero.
+ */
+ png_charp pcal_purpose; /* pCAL chunk description string */
+ png_int_32 pcal_X0; /* minimum value */
+ png_int_32 pcal_X1; /* maximum value */
+ png_charp pcal_units; /* Latin-1 string giving physical units */
+ png_charpp pcal_params; /* ASCII strings containing parameter values */
+ png_byte pcal_type; /* equation type (see PNG_EQUATION_ below) */
+ png_byte pcal_nparams; /* number of parameters given in pcal_params */
+#endif
+
+/* New members added in libpng-1.0.6 */
+ png_uint_32 free_me; /* flags items libpng is responsible for freeing */
+
+#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
+ /* Storage for unknown chunks that the library doesn't recognize. */
+ png_unknown_chunkp unknown_chunks;
+
+ /* The type of this field is limited by the type of
+ * png_struct::user_chunk_cache_max, else overflow can occur.
+ */
+ int unknown_chunks_num;
+#endif
+
+#ifdef PNG_sPLT_SUPPORTED
+ /* Data on sPLT chunks (there may be more than one). */
+ png_sPLT_tp splt_palettes;
+ int splt_palettes_num; /* Match type returned by png_get API */
+#endif
+
+#ifdef PNG_sCAL_SUPPORTED
+ /* The sCAL chunk describes the actual physical dimensions of the
+ * subject matter of the graphic. The chunk contains a unit specification
+ * a byte value, and two ASCII strings representing floating-point
+ * values. The values are width and height corresponsing to one pixel
+ * in the image. Data values are valid if (valid & PNG_INFO_sCAL) is
+ * non-zero.
+ */
+ png_byte scal_unit; /* unit of physical scale */
+ png_charp scal_s_width; /* string containing height */
+ png_charp scal_s_height; /* string containing width */
+#endif
+
+#ifdef PNG_INFO_IMAGE_SUPPORTED
+ /* Memory has been allocated if (valid & PNG_ALLOCATED_INFO_ROWS)
+ non-zero */
+ /* Data valid if (valid & PNG_INFO_IDAT) non-zero */
+ png_bytepp row_pointers; /* the image bits */
+#endif
+
+};
+#endif /* PNGINFO_H */
diff --git a/third_party/lpng_v163/pnglibconf.h b/third_party/libpng/pnglibconf.h
similarity index 93%
rename from third_party/lpng_v163/pnglibconf.h
rename to third_party/libpng/pnglibconf.h
index ececc38..adf4238 100644
--- a/third_party/lpng_v163/pnglibconf.h
+++ b/third_party/libpng/pnglibconf.h
@@ -1,211 +1,214 @@
-/* libpng 1.6.3 STANDARD API DEFINITION */
-
-/* pnglibconf.h - library build configuration */
-
-/* Libpng version 1.6.3 - July 18, 2013 */
-
-/* Copyright (c) 1998-2013 Glenn Randers-Pehrson */
-
-/* This code is released under the libpng license. */
-/* For conditions of distribution and use, see the disclaimer */
-/* and license in png.h */
-
-/* pnglibconf.h */
-/* Machine generated file: DO NOT EDIT */
-/* Derived from: scripts/pnglibconf.dfa */
-#ifndef PNGLCONF_H
-#define PNGLCONF_H
-/* options */
-#define PNG_16BIT_SUPPORTED
-#define PNG_ALIGNED_MEMORY_SUPPORTED
-/*#undef PNG_ARM_NEON_API_SUPPORTED*/
-/*#undef PNG_ARM_NEON_CHECK_SUPPORTED*/
-#define PNG_BENIGN_ERRORS_SUPPORTED
-#define PNG_BENIGN_READ_ERRORS_SUPPORTED
-/*#undef PNG_BENIGN_WRITE_ERRORS_SUPPORTED*/
-#define PNG_BUILD_GRAYSCALE_PALETTE_SUPPORTED
-#define PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED
-#define PNG_COLORSPACE_SUPPORTED
-#define PNG_CONSOLE_IO_SUPPORTED
-#define PNG_CONVERT_tIME_SUPPORTED
-#define PNG_EASY_ACCESS_SUPPORTED
-/*#undef PNG_ERROR_NUMBERS_SUPPORTED*/
-#define PNG_ERROR_TEXT_SUPPORTED
-#define PNG_FIXED_POINT_SUPPORTED
-#define PNG_FLOATING_ARITHMETIC_SUPPORTED
-#define PNG_FLOATING_POINT_SUPPORTED
-#define PNG_FORMAT_AFIRST_SUPPORTED
-#define PNG_FORMAT_BGR_SUPPORTED
-#define PNG_GAMMA_SUPPORTED
-#define PNG_GET_PALETTE_MAX_SUPPORTED
-#define PNG_HANDLE_AS_UNKNOWN_SUPPORTED
-#define PNG_INCH_CONVERSIONS_SUPPORTED
-#define PNG_INFO_IMAGE_SUPPORTED
-#define PNG_IO_STATE_SUPPORTED
-#define PNG_MNG_FEATURES_SUPPORTED
-#define PNG_POINTER_INDEXING_SUPPORTED
-#define PNG_PROGRESSIVE_READ_SUPPORTED
-#define PNG_READ_16BIT_SUPPORTED
-#define PNG_READ_ALPHA_MODE_SUPPORTED
-#define PNG_READ_ANCILLARY_CHUNKS_SUPPORTED
-#define PNG_READ_BACKGROUND_SUPPORTED
-#define PNG_READ_BGR_SUPPORTED
-#define PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED
-#define PNG_READ_COMPOSITE_NODIV_SUPPORTED
-#define PNG_READ_COMPRESSED_TEXT_SUPPORTED
-#define PNG_READ_EXPAND_16_SUPPORTED
-#define PNG_READ_EXPAND_SUPPORTED
-#define PNG_READ_FILLER_SUPPORTED
-#define PNG_READ_GAMMA_SUPPORTED
-#define PNG_READ_GET_PALETTE_MAX_SUPPORTED
-#define PNG_READ_GRAY_TO_RGB_SUPPORTED
-#define PNG_READ_INTERLACING_SUPPORTED
-#define PNG_READ_INT_FUNCTIONS_SUPPORTED
-#define PNG_READ_INVERT_ALPHA_SUPPORTED
-#define PNG_READ_INVERT_SUPPORTED
-#define PNG_READ_OPT_PLTE_SUPPORTED
-#define PNG_READ_PACKSWAP_SUPPORTED
-#define PNG_READ_PACK_SUPPORTED
-#define PNG_READ_QUANTIZE_SUPPORTED
-#define PNG_READ_RGB_TO_GRAY_SUPPORTED
-#define PNG_READ_SCALE_16_TO_8_SUPPORTED
-#define PNG_READ_SHIFT_SUPPORTED
-#define PNG_READ_STRIP_16_TO_8_SUPPORTED
-#define PNG_READ_STRIP_ALPHA_SUPPORTED
-#define PNG_READ_SUPPORTED
-#define PNG_READ_SWAP_ALPHA_SUPPORTED
-#define PNG_READ_SWAP_SUPPORTED
-#define PNG_READ_TEXT_SUPPORTED
-#define PNG_READ_TRANSFORMS_SUPPORTED
-#define PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
-#define PNG_READ_USER_CHUNKS_SUPPORTED
-#define PNG_READ_USER_TRANSFORM_SUPPORTED
-#define PNG_READ_bKGD_SUPPORTED
-#define PNG_READ_cHRM_SUPPORTED
-#define PNG_READ_gAMA_SUPPORTED
-#define PNG_READ_hIST_SUPPORTED
-#define PNG_READ_iCCP_SUPPORTED
-#define PNG_READ_iTXt_SUPPORTED
-#define PNG_READ_oFFs_SUPPORTED
-#define PNG_READ_pCAL_SUPPORTED
-#define PNG_READ_pHYs_SUPPORTED
-#define PNG_READ_sBIT_SUPPORTED
-#define PNG_READ_sCAL_SUPPORTED
-#define PNG_READ_sPLT_SUPPORTED
-#define PNG_READ_sRGB_SUPPORTED
-#define PNG_READ_tEXt_SUPPORTED
-#define PNG_READ_tIME_SUPPORTED
-#define PNG_READ_tRNS_SUPPORTED
-#define PNG_READ_zTXt_SUPPORTED
-/*#undef PNG_SAFE_LIMITS_SUPPORTED*/
-#define PNG_SAVE_INT_32_SUPPORTED
-#define PNG_SAVE_UNKNOWN_CHUNKS_SUPPORTED
-#define PNG_SEQUENTIAL_READ_SUPPORTED
-#define PNG_SETJMP_SUPPORTED
-#define PNG_SET_CHUNK_CACHE_LIMIT_SUPPORTED
-#define PNG_SET_CHUNK_MALLOC_LIMIT_SUPPORTED
-#define PNG_SET_OPTION_SUPPORTED
-#define PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
-#define PNG_SET_USER_LIMITS_SUPPORTED
-#define PNG_SIMPLIFIED_READ_AFIRST_SUPPORTED
-#define PNG_SIMPLIFIED_READ_BGR_SUPPORTED
-#define PNG_SIMPLIFIED_READ_SUPPORTED
-#define PNG_SIMPLIFIED_WRITE_AFIRST_SUPPORTED
-#define PNG_SIMPLIFIED_WRITE_BGR_SUPPORTED
-#define PNG_SIMPLIFIED_WRITE_SUPPORTED
-#define PNG_STDIO_SUPPORTED
-#define PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
-#define PNG_TEXT_SUPPORTED
-#define PNG_TIME_RFC1123_SUPPORTED
-#define PNG_UNKNOWN_CHUNKS_SUPPORTED
-#define PNG_USER_CHUNKS_SUPPORTED
-#define PNG_USER_LIMITS_SUPPORTED
-#define PNG_USER_MEM_SUPPORTED
-#define PNG_USER_TRANSFORM_INFO_SUPPORTED
-#define PNG_USER_TRANSFORM_PTR_SUPPORTED
-#define PNG_WARNINGS_SUPPORTED
-#define PNG_WRITE_16BIT_SUPPORTED
-#define PNG_WRITE_ANCILLARY_CHUNKS_SUPPORTED
-#define PNG_WRITE_BGR_SUPPORTED
-#define PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED
-#define PNG_WRITE_COMPRESSED_TEXT_SUPPORTED
-#define PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
-#define PNG_WRITE_FILLER_SUPPORTED
-#define PNG_WRITE_FILTER_SUPPORTED
-#define PNG_WRITE_FLUSH_SUPPORTED
-#define PNG_WRITE_GET_PALETTE_MAX_SUPPORTED
-#define PNG_WRITE_INTERLACING_SUPPORTED
-#define PNG_WRITE_INT_FUNCTIONS_SUPPORTED
-#define PNG_WRITE_INVERT_ALPHA_SUPPORTED
-#define PNG_WRITE_INVERT_SUPPORTED
-#define PNG_WRITE_OPTIMIZE_CMF_SUPPORTED
-#define PNG_WRITE_PACKSWAP_SUPPORTED
-#define PNG_WRITE_PACK_SUPPORTED
-#define PNG_WRITE_SHIFT_SUPPORTED
-#define PNG_WRITE_SUPPORTED
-#define PNG_WRITE_SWAP_ALPHA_SUPPORTED
-#define PNG_WRITE_SWAP_SUPPORTED
-#define PNG_WRITE_TEXT_SUPPORTED
-#define PNG_WRITE_TRANSFORMS_SUPPORTED
-#define PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
-#define PNG_WRITE_USER_TRANSFORM_SUPPORTED
-#define PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
-#define PNG_WRITE_bKGD_SUPPORTED
-#define PNG_WRITE_cHRM_SUPPORTED
-#define PNG_WRITE_gAMA_SUPPORTED
-#define PNG_WRITE_hIST_SUPPORTED
-#define PNG_WRITE_iCCP_SUPPORTED
-#define PNG_WRITE_iTXt_SUPPORTED
-#define PNG_WRITE_oFFs_SUPPORTED
-#define PNG_WRITE_pCAL_SUPPORTED
-#define PNG_WRITE_pHYs_SUPPORTED
-#define PNG_WRITE_sBIT_SUPPORTED
-#define PNG_WRITE_sCAL_SUPPORTED
-#define PNG_WRITE_sPLT_SUPPORTED
-#define PNG_WRITE_sRGB_SUPPORTED
-#define PNG_WRITE_tEXt_SUPPORTED
-#define PNG_WRITE_tIME_SUPPORTED
-#define PNG_WRITE_tRNS_SUPPORTED
-#define PNG_WRITE_zTXt_SUPPORTED
-#define PNG_bKGD_SUPPORTED
-#define PNG_cHRM_SUPPORTED
-#define PNG_gAMA_SUPPORTED
-#define PNG_hIST_SUPPORTED
-#define PNG_iCCP_SUPPORTED
-#define PNG_iTXt_SUPPORTED
-#define PNG_oFFs_SUPPORTED
-#define PNG_pCAL_SUPPORTED
-#define PNG_pHYs_SUPPORTED
-#define PNG_sBIT_SUPPORTED
-#define PNG_sCAL_SUPPORTED
-#define PNG_sPLT_SUPPORTED
-#define PNG_sRGB_SUPPORTED
-#define PNG_tEXt_SUPPORTED
-#define PNG_tIME_SUPPORTED
-#define PNG_tRNS_SUPPORTED
-#define PNG_zTXt_SUPPORTED
-/* end of options */
-/* settings */
-#define PNG_API_RULE 0
-#define PNG_CALLOC_SUPPORTED
-#define PNG_COST_SHIFT 3
-#define PNG_DEFAULT_READ_MACROS 1
-#define PNG_GAMMA_THRESHOLD_FIXED 5000
-#define PNG_IDAT_READ_SIZE PNG_ZBUF_SIZE
-#define PNG_INFLATE_BUF_SIZE 1024
-#define PNG_MAX_GAMMA_8 11
-#define PNG_QUANTIZE_BLUE_BITS 5
-#define PNG_QUANTIZE_GREEN_BITS 5
-#define PNG_QUANTIZE_RED_BITS 5
-#define PNG_TEXT_Z_DEFAULT_COMPRESSION (-1)
-#define PNG_TEXT_Z_DEFAULT_STRATEGY 0
-#define PNG_WEIGHT_SHIFT 8
-#define PNG_ZBUF_SIZE 8192
-#define PNG_ZLIB_VERNUM 0 /* unknown */
-#define PNG_Z_DEFAULT_COMPRESSION (-1)
-#define PNG_Z_DEFAULT_NOFILTER_STRATEGY 0
-#define PNG_Z_DEFAULT_STRATEGY 1
-#define PNG_sCAL_PRECISION 5
-#define PNG_sRGB_PROFILE_CHECKS 2
-/* end of settings */
-#endif /* PNGLCONF_H */
+/* libpng 1.6.20 STANDARD API DEFINITION */
+
+/* pnglibconf.h - library build configuration */
+
+/* Libpng version 1.6.20 - December 3, 2015 */
+
+/* Copyright (c) 1998-2015 Glenn Randers-Pehrson */
+
+/* This code is released under the libpng license. */
+/* For conditions of distribution and use, see the disclaimer */
+/* and license in png.h */
+
+/* pnglibconf.h */
+/* Machine generated file: DO NOT EDIT */
+/* Derived from: scripts/pnglibconf.dfa */
+#ifndef PNGLCONF_H
+#define PNGLCONF_H
+/* options */
+#define PNG_16BIT_SUPPORTED
+#define PNG_ALIGNED_MEMORY_SUPPORTED
+/*#undef PNG_ARM_NEON_API_SUPPORTED*/
+/*#undef PNG_ARM_NEON_CHECK_SUPPORTED*/
+#define PNG_BENIGN_ERRORS_SUPPORTED
+#define PNG_BENIGN_READ_ERRORS_SUPPORTED
+/*#undef PNG_BENIGN_WRITE_ERRORS_SUPPORTED*/
+#define PNG_BUILD_GRAYSCALE_PALETTE_SUPPORTED
+#define PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED
+#define PNG_COLORSPACE_SUPPORTED
+#define PNG_CONSOLE_IO_SUPPORTED
+#define PNG_CONVERT_tIME_SUPPORTED
+#define PNG_EASY_ACCESS_SUPPORTED
+/*#undef PNG_ERROR_NUMBERS_SUPPORTED*/
+#define PNG_ERROR_TEXT_SUPPORTED
+#define PNG_FIXED_POINT_SUPPORTED
+#define PNG_FLOATING_ARITHMETIC_SUPPORTED
+#define PNG_FLOATING_POINT_SUPPORTED
+#define PNG_FORMAT_AFIRST_SUPPORTED
+#define PNG_FORMAT_BGR_SUPPORTED
+#define PNG_GAMMA_SUPPORTED
+#define PNG_GET_PALETTE_MAX_SUPPORTED
+#define PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+#define PNG_INCH_CONVERSIONS_SUPPORTED
+#define PNG_INFO_IMAGE_SUPPORTED
+#define PNG_IO_STATE_SUPPORTED
+#define PNG_MNG_FEATURES_SUPPORTED
+#define PNG_POINTER_INDEXING_SUPPORTED
+#define PNG_PROGRESSIVE_READ_SUPPORTED
+#define PNG_READ_16BIT_SUPPORTED
+#define PNG_READ_ALPHA_MODE_SUPPORTED
+#define PNG_READ_ANCILLARY_CHUNKS_SUPPORTED
+#define PNG_READ_BACKGROUND_SUPPORTED
+#define PNG_READ_BGR_SUPPORTED
+#define PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED
+#define PNG_READ_COMPOSITE_NODIV_SUPPORTED
+#define PNG_READ_COMPRESSED_TEXT_SUPPORTED
+#define PNG_READ_EXPAND_16_SUPPORTED
+#define PNG_READ_EXPAND_SUPPORTED
+#define PNG_READ_FILLER_SUPPORTED
+#define PNG_READ_GAMMA_SUPPORTED
+#define PNG_READ_GET_PALETTE_MAX_SUPPORTED
+#define PNG_READ_GRAY_TO_RGB_SUPPORTED
+#define PNG_READ_INTERLACING_SUPPORTED
+#define PNG_READ_INT_FUNCTIONS_SUPPORTED
+#define PNG_READ_INVERT_ALPHA_SUPPORTED
+#define PNG_READ_INVERT_SUPPORTED
+#define PNG_READ_OPT_PLTE_SUPPORTED
+#define PNG_READ_PACKSWAP_SUPPORTED
+#define PNG_READ_PACK_SUPPORTED
+#define PNG_READ_QUANTIZE_SUPPORTED
+#define PNG_READ_RGB_TO_GRAY_SUPPORTED
+#define PNG_READ_SCALE_16_TO_8_SUPPORTED
+#define PNG_READ_SHIFT_SUPPORTED
+#define PNG_READ_STRIP_16_TO_8_SUPPORTED
+#define PNG_READ_STRIP_ALPHA_SUPPORTED
+#define PNG_READ_SUPPORTED
+#define PNG_READ_SWAP_ALPHA_SUPPORTED
+#define PNG_READ_SWAP_SUPPORTED
+#define PNG_READ_TEXT_SUPPORTED
+#define PNG_READ_TRANSFORMS_SUPPORTED
+#define PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
+#define PNG_READ_USER_CHUNKS_SUPPORTED
+#define PNG_READ_USER_TRANSFORM_SUPPORTED
+#define PNG_READ_bKGD_SUPPORTED
+#define PNG_READ_cHRM_SUPPORTED
+#define PNG_READ_gAMA_SUPPORTED
+#define PNG_READ_hIST_SUPPORTED
+#define PNG_READ_iCCP_SUPPORTED
+#define PNG_READ_iTXt_SUPPORTED
+#define PNG_READ_oFFs_SUPPORTED
+#define PNG_READ_pCAL_SUPPORTED
+#define PNG_READ_pHYs_SUPPORTED
+#define PNG_READ_sBIT_SUPPORTED
+#define PNG_READ_sCAL_SUPPORTED
+#define PNG_READ_sPLT_SUPPORTED
+#define PNG_READ_sRGB_SUPPORTED
+#define PNG_READ_tEXt_SUPPORTED
+#define PNG_READ_tIME_SUPPORTED
+#define PNG_READ_tRNS_SUPPORTED
+#define PNG_READ_zTXt_SUPPORTED
+#define PNG_SAVE_INT_32_SUPPORTED
+#define PNG_SAVE_UNKNOWN_CHUNKS_SUPPORTED
+#define PNG_SEQUENTIAL_READ_SUPPORTED
+#define PNG_SETJMP_SUPPORTED
+#define PNG_SET_OPTION_SUPPORTED
+#define PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
+#define PNG_SET_USER_LIMITS_SUPPORTED
+#define PNG_SIMPLIFIED_READ_AFIRST_SUPPORTED
+#define PNG_SIMPLIFIED_READ_BGR_SUPPORTED
+#define PNG_SIMPLIFIED_READ_SUPPORTED
+#define PNG_SIMPLIFIED_WRITE_AFIRST_SUPPORTED
+#define PNG_SIMPLIFIED_WRITE_BGR_SUPPORTED
+#define PNG_SIMPLIFIED_WRITE_SUPPORTED
+#define PNG_STDIO_SUPPORTED
+#define PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
+#define PNG_TEXT_SUPPORTED
+#define PNG_TIME_RFC1123_SUPPORTED
+#define PNG_UNKNOWN_CHUNKS_SUPPORTED
+#define PNG_USER_CHUNKS_SUPPORTED
+#define PNG_USER_LIMITS_SUPPORTED
+#define PNG_USER_MEM_SUPPORTED
+#define PNG_USER_TRANSFORM_INFO_SUPPORTED
+#define PNG_USER_TRANSFORM_PTR_SUPPORTED
+#define PNG_WARNINGS_SUPPORTED
+#define PNG_WRITE_16BIT_SUPPORTED
+#define PNG_WRITE_ANCILLARY_CHUNKS_SUPPORTED
+#define PNG_WRITE_BGR_SUPPORTED
+#define PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED
+#define PNG_WRITE_COMPRESSED_TEXT_SUPPORTED
+#define PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED
+#define PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
+#define PNG_WRITE_FILLER_SUPPORTED
+#define PNG_WRITE_FILTER_SUPPORTED
+#define PNG_WRITE_FLUSH_SUPPORTED
+#define PNG_WRITE_GET_PALETTE_MAX_SUPPORTED
+#define PNG_WRITE_INTERLACING_SUPPORTED
+#define PNG_WRITE_INT_FUNCTIONS_SUPPORTED
+#define PNG_WRITE_INVERT_ALPHA_SUPPORTED
+#define PNG_WRITE_INVERT_SUPPORTED
+#define PNG_WRITE_OPTIMIZE_CMF_SUPPORTED
+#define PNG_WRITE_PACKSWAP_SUPPORTED
+#define PNG_WRITE_PACK_SUPPORTED
+#define PNG_WRITE_SHIFT_SUPPORTED
+#define PNG_WRITE_SUPPORTED
+#define PNG_WRITE_SWAP_ALPHA_SUPPORTED
+#define PNG_WRITE_SWAP_SUPPORTED
+#define PNG_WRITE_TEXT_SUPPORTED
+#define PNG_WRITE_TRANSFORMS_SUPPORTED
+#define PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
+#define PNG_WRITE_USER_TRANSFORM_SUPPORTED
+#define PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
+#define PNG_WRITE_bKGD_SUPPORTED
+#define PNG_WRITE_cHRM_SUPPORTED
+#define PNG_WRITE_gAMA_SUPPORTED
+#define PNG_WRITE_hIST_SUPPORTED
+#define PNG_WRITE_iCCP_SUPPORTED
+#define PNG_WRITE_iTXt_SUPPORTED
+#define PNG_WRITE_oFFs_SUPPORTED
+#define PNG_WRITE_pCAL_SUPPORTED
+#define PNG_WRITE_pHYs_SUPPORTED
+#define PNG_WRITE_sBIT_SUPPORTED
+#define PNG_WRITE_sCAL_SUPPORTED
+#define PNG_WRITE_sPLT_SUPPORTED
+#define PNG_WRITE_sRGB_SUPPORTED
+#define PNG_WRITE_tEXt_SUPPORTED
+#define PNG_WRITE_tIME_SUPPORTED
+#define PNG_WRITE_tRNS_SUPPORTED
+#define PNG_WRITE_zTXt_SUPPORTED
+#define PNG_bKGD_SUPPORTED
+#define PNG_cHRM_SUPPORTED
+#define PNG_gAMA_SUPPORTED
+#define PNG_hIST_SUPPORTED
+#define PNG_iCCP_SUPPORTED
+#define PNG_iTXt_SUPPORTED
+#define PNG_oFFs_SUPPORTED
+#define PNG_pCAL_SUPPORTED
+#define PNG_pHYs_SUPPORTED
+#define PNG_sBIT_SUPPORTED
+#define PNG_sCAL_SUPPORTED
+#define PNG_sPLT_SUPPORTED
+#define PNG_sRGB_SUPPORTED
+#define PNG_tEXt_SUPPORTED
+#define PNG_tIME_SUPPORTED
+#define PNG_tRNS_SUPPORTED
+#define PNG_zTXt_SUPPORTED
+/* end of options */
+/* settings */
+#define PNG_API_RULE 0
+#define PNG_DEFAULT_READ_MACROS 1
+#define PNG_GAMMA_THRESHOLD_FIXED 5000
+#define PNG_IDAT_READ_SIZE PNG_ZBUF_SIZE
+#define PNG_INFLATE_BUF_SIZE 1024
+#define PNG_LINKAGE_API extern
+#define PNG_LINKAGE_CALLBACK extern
+#define PNG_LINKAGE_DATA extern
+#define PNG_LINKAGE_FUNCTION extern
+#define PNG_MAX_GAMMA_8 11
+#define PNG_QUANTIZE_BLUE_BITS 5
+#define PNG_QUANTIZE_GREEN_BITS 5
+#define PNG_QUANTIZE_RED_BITS 5
+#define PNG_TEXT_Z_DEFAULT_COMPRESSION (-1)
+#define PNG_TEXT_Z_DEFAULT_STRATEGY 0
+#define PNG_USER_CHUNK_CACHE_MAX 1000
+#define PNG_USER_CHUNK_MALLOC_MAX 8000000
+#define PNG_USER_HEIGHT_MAX 1000000
+#define PNG_USER_WIDTH_MAX 1000000
+#define PNG_ZBUF_SIZE 8192
+#define PNG_ZLIB_VERNUM 0 /* unknown */
+#define PNG_Z_DEFAULT_COMPRESSION (-1)
+#define PNG_Z_DEFAULT_NOFILTER_STRATEGY 0
+#define PNG_Z_DEFAULT_STRATEGY 1
+#define PNG_sCAL_PRECISION 5
+#define PNG_sRGB_PROFILE_CHECKS 2
+/* end of settings */
+#endif /* PNGLCONF_H */
diff --git a/third_party/lpng_v163/pngmem.c b/third_party/libpng/pngmem.c
similarity index 92%
rename from third_party/lpng_v163/pngmem.c
rename to third_party/libpng/pngmem.c
index cbbd4db..db71219 100644
--- a/third_party/lpng_v163/pngmem.c
+++ b/third_party/libpng/pngmem.c
@@ -1,281 +1,287 @@
-/* pngmem.c - stub functions for memory allocation
- *
- * Last changed in libpng 1.6.0 [February 14, 2013]
- * Copyright (c) 1998-2013 Glenn Randers-Pehrson
- * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
- * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
- *
- * This code is released under the libpng license.
- * For conditions of distribution and use, see the disclaimer
- * and license in png.h
- *
- * This file provides a location for all memory allocation. Users who
- * need special memory handling are expected to supply replacement
- * functions for png_malloc() and png_free(), and to use
- * png_create_read_struct_2() and png_create_write_struct_2() to
- * identify the replacement functions.
- */
-
-#include "pngpriv.h"
-
-void* FXMEM_DefaultAlloc(int byte_size, int);
-void FXMEM_DefaultFree(void* pointer, int);
-
-#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
-/* Free a png_struct */
-void /* PRIVATE */
-png_destroy_png_struct(png_structrp png_ptr)
-{
- if (png_ptr != NULL)
- {
- /* png_free might call png_error and may certainly call
- * png_get_mem_ptr, so fake a temporary png_struct to support this.
- */
- png_struct dummy_struct = *png_ptr;
- memset(png_ptr, 0, (sizeof *png_ptr));
- png_free(&dummy_struct, png_ptr);
-
-# ifdef PNG_SETJMP_SUPPORTED
- /* We may have a jmp_buf left to deallocate. */
- png_free_jmpbuf(&dummy_struct);
-# endif
- }
-}
-
-/* Allocate memory. For reasonable files, size should never exceed
- * 64K. However, zlib may allocate more then 64K if you don't tell
- * it not to. See zconf.h and png.h for more information. zlib does
- * need to allocate exactly 64K, so whatever you call here must
- * have the ability to do that.
- */
-PNG_FUNCTION(png_voidp,PNGAPI
-png_calloc,(png_const_structrp png_ptr, png_alloc_size_t size),PNG_ALLOCATED)
-{
- png_voidp ret;
-
- ret = png_malloc(png_ptr, size);
-
- if (ret != NULL)
- memset(ret, 0, size);
-
- return ret;
-}
-
-/* png_malloc_base, an internal function added at libpng 1.6.0, does the work of
- * allocating memory, taking into account limits and PNG_USER_MEM_SUPPORTED.
- * Checking and error handling must happen outside this routine; it returns NULL
- * if the allocation cannot be done (for any reason.)
- */
-PNG_FUNCTION(png_voidp /* PRIVATE */,
-png_malloc_base,(png_const_structrp png_ptr, png_alloc_size_t size),
- PNG_ALLOCATED)
-{
- /* Moved to png_malloc_base from png_malloc_default in 1.6.0; the DOS
- * allocators have also been removed in 1.6.0, so any 16-bit system now has
- * to implement a user memory handler. This checks to be sure it isn't
- * called with big numbers.
- */
-#ifdef PNG_USER_MEM_SUPPORTED
- PNG_UNUSED(png_ptr)
-#endif
- if (size > 0 && size <= PNG_SIZE_MAX
-# ifdef PNG_MAX_MALLOC_64K
- && size <= 65536U
-# endif
- )
- {
-#ifdef PNG_USER_MEM_SUPPORTED
- if (png_ptr != NULL && png_ptr->malloc_fn != NULL)
- return png_ptr->malloc_fn(png_constcast(png_structrp,png_ptr), size);
-
- else
-#endif
- return FXMEM_DefaultAlloc((int)size, 0);
- //return malloc((size_t)size); /* checked for truncation above */
- }
-
- else
- return NULL;
-}
-
-/* This is really here only to work round a spurious warning in GCC 4.6 and 4.7
- * that arises because of the checks in png_realloc_array that are repeated in
- * png_malloc_array.
- */
-static png_voidp
-png_malloc_array_checked(png_const_structrp png_ptr, int nelements,
- size_t element_size)
-{
- png_alloc_size_t req = nelements; /* known to be > 0 */
-
- if (req <= PNG_SIZE_MAX/element_size)
- return png_malloc_base(png_ptr, req * element_size);
-
- /* The failure case when the request is too large */
- return NULL;
-}
-
-PNG_FUNCTION(png_voidp /* PRIVATE */,
-png_malloc_array,(png_const_structrp png_ptr, int nelements,
- size_t element_size),PNG_ALLOCATED)
-{
- if (nelements <= 0 || element_size == 0)
- png_error(png_ptr, "internal error: array alloc");
-
- return png_malloc_array_checked(png_ptr, nelements, element_size);
-}
-
-PNG_FUNCTION(png_voidp /* PRIVATE */,
-png_realloc_array,(png_const_structrp png_ptr, png_const_voidp old_array,
- int old_elements, int add_elements, size_t element_size),PNG_ALLOCATED)
-{
- /* These are internal errors: */
- if (add_elements <= 0 || element_size == 0 || old_elements < 0 ||
- (old_array == NULL && old_elements > 0))
- png_error(png_ptr, "internal error: array realloc");
-
- /* Check for overflow on the elements count (so the caller does not have to
- * check.)
- */
- if (add_elements <= INT_MAX - old_elements)
- {
- png_voidp new_array = png_malloc_array_checked(png_ptr,
- old_elements+add_elements, element_size);
-
- if (new_array != NULL)
- {
- /* Because png_malloc_array worked the size calculations below cannot
- * overflow.
- */
- if (old_elements > 0)
- memcpy(new_array, old_array, element_size*(unsigned)old_elements);
-
- memset((char*)new_array + element_size*(unsigned)old_elements, 0,
- element_size*(unsigned)add_elements);
-
- return new_array;
- }
- }
-
- return NULL; /* error */
-}
-
-/* Various functions that have different error handling are derived from this.
- * png_malloc always exists, but if PNG_USER_MEM_SUPPORTED is defined a separate
- * function png_malloc_default is also provided.
- */
-PNG_FUNCTION(png_voidp,PNGAPI
-png_malloc,(png_const_structrp png_ptr, png_alloc_size_t size),PNG_ALLOCATED)
-{
- png_voidp ret;
-
- if (png_ptr == NULL)
- return NULL;
-
- ret = png_malloc_base(png_ptr, size);
-
- if (ret == NULL)
- png_error(png_ptr, "Out of memory"); /* 'm' means png_malloc */
-
- return ret;
-}
-
-#ifdef PNG_USER_MEM_SUPPORTED
-PNG_FUNCTION(png_voidp,PNGAPI
-png_malloc_default,(png_const_structrp png_ptr, png_alloc_size_t size),
- PNG_ALLOCATED PNG_DEPRECATED)
-{
- png_voidp ret;
-
- if (png_ptr == NULL)
- return NULL;
-
- /* Passing 'NULL' here bypasses the application provided memory handler. */
- ret = png_malloc_base(NULL/*use malloc*/, size);
-
- if (ret == NULL)
- png_error(png_ptr, "Out of Memory"); /* 'M' means png_malloc_default */
-
- return ret;
-}
-#endif /* PNG_USER_MEM_SUPPORTED */
-
-/* This function was added at libpng version 1.2.3. The png_malloc_warn()
- * function will issue a png_warning and return NULL instead of issuing a
- * png_error, if it fails to allocate the requested memory.
- */
-PNG_FUNCTION(png_voidp,PNGAPI
-png_malloc_warn,(png_const_structrp png_ptr, png_alloc_size_t size),
- PNG_ALLOCATED)
-{
- if (png_ptr != NULL)
- {
- png_voidp ret = png_malloc_base(png_ptr, size);
-
- if (ret != NULL)
- return ret;
-
- png_warning(png_ptr, "Out of memory");
- }
-
- return NULL;
-}
-
-/* Free a pointer allocated by png_malloc(). If ptr is NULL, return
- * without taking any action.
- */
-void PNGAPI
-png_free(png_const_structrp png_ptr, png_voidp ptr)
-{
- if (png_ptr == NULL || ptr == NULL)
- return;
-
-#ifdef PNG_USER_MEM_SUPPORTED
- if (png_ptr->free_fn != NULL)
- png_ptr->free_fn(png_constcast(png_structrp,png_ptr), ptr);
-
- else
- png_free_default(png_ptr, ptr);
-}
-
-PNG_FUNCTION(void,PNGAPI
-png_free_default,(png_const_structrp png_ptr, png_voidp ptr),PNG_DEPRECATED)
-{
- if (png_ptr == NULL || ptr == NULL)
- return;
-#endif /* PNG_USER_MEM_SUPPORTED */
-
- FXMEM_DefaultFree(ptr, 0);
- //free(ptr);
-}
-
-#ifdef PNG_USER_MEM_SUPPORTED
-/* This function is called when the application wants to use another method
- * of allocating and freeing memory.
- */
-void PNGAPI
-png_set_mem_fn(png_structrp png_ptr, png_voidp mem_ptr, png_malloc_ptr
- malloc_fn, png_free_ptr free_fn)
-{
- if (png_ptr != NULL)
- {
- png_ptr->mem_ptr = mem_ptr;
- png_ptr->malloc_fn = malloc_fn;
- png_ptr->free_fn = free_fn;
- }
-}
-
-/* This function returns a pointer to the mem_ptr associated with the user
- * functions. The application should free any memory associated with this
- * pointer before png_write_destroy and png_read_destroy are called.
- */
-png_voidp PNGAPI
-png_get_mem_ptr(png_const_structrp png_ptr)
-{
- if (png_ptr == NULL)
- return NULL;
-
- return png_ptr->mem_ptr;
-}
-#endif /* PNG_USER_MEM_SUPPORTED */
-#endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */
+
+/* pngmem.c - stub functions for memory allocation
+ *
+ * Last changed in libpng 1.6.15 [November 20, 2014]
+ * Copyright (c) 1998-2014 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ * This file provides a location for all memory allocation. Users who
+ * need special memory handling are expected to supply replacement
+ * functions for png_malloc() and png_free(), and to use
+ * png_create_read_struct_2() and png_create_write_struct_2() to
+ * identify the replacement functions.
+ */
+
+#include "pngpriv.h"
+
+void* FXMEM_DefaultAlloc(int byte_size, int);
+void FXMEM_DefaultFree(void* pointer, int);
+
+#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
+/* Free a png_struct */
+void /* PRIVATE */
+png_destroy_png_struct(png_structrp png_ptr)
+{
+ if (png_ptr != NULL)
+ {
+ /* png_free might call png_error and may certainly call
+ * png_get_mem_ptr, so fake a temporary png_struct to support this.
+ */
+ png_struct dummy_struct = *png_ptr;
+ memset(png_ptr, 0, (sizeof *png_ptr));
+ png_free(&dummy_struct, png_ptr);
+
+# ifdef PNG_SETJMP_SUPPORTED
+ /* We may have a jmp_buf left to deallocate. */
+ png_free_jmpbuf(&dummy_struct);
+# endif
+ }
+}
+
+/* Allocate memory. For reasonable files, size should never exceed
+ * 64K. However, zlib may allocate more than 64K if you don't tell
+ * it not to. See zconf.h and png.h for more information. zlib does
+ * need to allocate exactly 64K, so whatever you call here must
+ * have the ability to do that.
+ */
+PNG_FUNCTION(png_voidp,PNGAPI
+png_calloc,(png_const_structrp png_ptr, png_alloc_size_t size),PNG_ALLOCATED)
+{
+ png_voidp ret;
+
+ ret = png_malloc(png_ptr, size);
+
+ if (ret != NULL)
+ memset(ret, 0, size);
+
+ return ret;
+}
+
+/* png_malloc_base, an internal function added at libpng 1.6.0, does the work of
+ * allocating memory, taking into account limits and PNG_USER_MEM_SUPPORTED.
+ * Checking and error handling must happen outside this routine; it returns NULL
+ * if the allocation cannot be done (for any reason.)
+ */
+PNG_FUNCTION(png_voidp /* PRIVATE */,
+png_malloc_base,(png_const_structrp png_ptr, png_alloc_size_t size),
+ PNG_ALLOCATED)
+{
+ /* Moved to png_malloc_base from png_malloc_default in 1.6.0; the DOS
+ * allocators have also been removed in 1.6.0, so any 16-bit system now has
+ * to implement a user memory handler. This checks to be sure it isn't
+ * called with big numbers.
+ */
+#ifndef PNG_USER_MEM_SUPPORTED
+ PNG_UNUSED(png_ptr)
+#endif
+
+ /* Some compilers complain that this is always true. However, it
+ * can be false when integer overflow happens.
+ */
+ if (size > 0 && size <= PNG_SIZE_MAX
+# ifdef PNG_MAX_MALLOC_64K
+ && size <= 65536U
+# endif
+ )
+ {
+#ifdef PNG_USER_MEM_SUPPORTED
+ if (png_ptr != NULL && png_ptr->malloc_fn != NULL)
+ return png_ptr->malloc_fn(png_constcast(png_structrp,png_ptr), size);
+
+ else
+#endif
+ return FXMEM_DefaultAlloc((int)size, 0);
+ }
+
+ else
+ return NULL;
+}
+
+#if defined(PNG_TEXT_SUPPORTED) || defined(PNG_sPLT_SUPPORTED) ||\
+ defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED)
+/* This is really here only to work round a spurious warning in GCC 4.6 and 4.7
+ * that arises because of the checks in png_realloc_array that are repeated in
+ * png_malloc_array.
+ */
+static png_voidp
+png_malloc_array_checked(png_const_structrp png_ptr, int nelements,
+ size_t element_size)
+{
+ png_alloc_size_t req = nelements; /* known to be > 0 */
+
+ if (req <= PNG_SIZE_MAX/element_size)
+ return png_malloc_base(png_ptr, req * element_size);
+
+ /* The failure case when the request is too large */
+ return NULL;
+}
+
+PNG_FUNCTION(png_voidp /* PRIVATE */,
+png_malloc_array,(png_const_structrp png_ptr, int nelements,
+ size_t element_size),PNG_ALLOCATED)
+{
+ if (nelements <= 0 || element_size == 0)
+ png_error(png_ptr, "internal error: array alloc");
+
+ return png_malloc_array_checked(png_ptr, nelements, element_size);
+}
+
+PNG_FUNCTION(png_voidp /* PRIVATE */,
+png_realloc_array,(png_const_structrp png_ptr, png_const_voidp old_array,
+ int old_elements, int add_elements, size_t element_size),PNG_ALLOCATED)
+{
+ /* These are internal errors: */
+ if (add_elements <= 0 || element_size == 0 || old_elements < 0 ||
+ (old_array == NULL && old_elements > 0))
+ png_error(png_ptr, "internal error: array realloc");
+
+ /* Check for overflow on the elements count (so the caller does not have to
+ * check.)
+ */
+ if (add_elements <= INT_MAX - old_elements)
+ {
+ png_voidp new_array = png_malloc_array_checked(png_ptr,
+ old_elements+add_elements, element_size);
+
+ if (new_array != NULL)
+ {
+ /* Because png_malloc_array worked the size calculations below cannot
+ * overflow.
+ */
+ if (old_elements > 0)
+ memcpy(new_array, old_array, element_size*(unsigned)old_elements);
+
+ memset((char*)new_array + element_size*(unsigned)old_elements, 0,
+ element_size*(unsigned)add_elements);
+
+ return new_array;
+ }
+ }
+
+ return NULL; /* error */
+}
+#endif /* TEXT || sPLT || STORE_UNKNOWN_CHUNKS */
+
+/* Various functions that have different error handling are derived from this.
+ * png_malloc always exists, but if PNG_USER_MEM_SUPPORTED is defined a separate
+ * function png_malloc_default is also provided.
+ */
+PNG_FUNCTION(png_voidp,PNGAPI
+png_malloc,(png_const_structrp png_ptr, png_alloc_size_t size),PNG_ALLOCATED)
+{
+ png_voidp ret;
+
+ if (png_ptr == NULL)
+ return NULL;
+
+ ret = png_malloc_base(png_ptr, size);
+
+ if (ret == NULL)
+ png_error(png_ptr, "Out of memory"); /* 'm' means png_malloc */
+
+ return ret;
+}
+
+#ifdef PNG_USER_MEM_SUPPORTED
+PNG_FUNCTION(png_voidp,PNGAPI
+png_malloc_default,(png_const_structrp png_ptr, png_alloc_size_t size),
+ PNG_ALLOCATED PNG_DEPRECATED)
+{
+ png_voidp ret;
+
+ if (png_ptr == NULL)
+ return NULL;
+
+ /* Passing 'NULL' here bypasses the application provided memory handler. */
+ ret = png_malloc_base(NULL/*use malloc*/, size);
+
+ if (ret == NULL)
+ png_error(png_ptr, "Out of Memory"); /* 'M' means png_malloc_default */
+
+ return ret;
+}
+#endif /* USER_MEM */
+
+/* This function was added at libpng version 1.2.3. The png_malloc_warn()
+ * function will issue a png_warning and return NULL instead of issuing a
+ * png_error, if it fails to allocate the requested memory.
+ */
+PNG_FUNCTION(png_voidp,PNGAPI
+png_malloc_warn,(png_const_structrp png_ptr, png_alloc_size_t size),
+ PNG_ALLOCATED)
+{
+ if (png_ptr != NULL)
+ {
+ png_voidp ret = png_malloc_base(png_ptr, size);
+
+ if (ret != NULL)
+ return ret;
+
+ png_warning(png_ptr, "Out of memory");
+ }
+
+ return NULL;
+}
+
+/* Free a pointer allocated by png_malloc(). If ptr is NULL, return
+ * without taking any action.
+ */
+void PNGAPI
+png_free(png_const_structrp png_ptr, png_voidp ptr)
+{
+ if (png_ptr == NULL || ptr == NULL)
+ return;
+
+#ifdef PNG_USER_MEM_SUPPORTED
+ if (png_ptr->free_fn != NULL)
+ png_ptr->free_fn(png_constcast(png_structrp,png_ptr), ptr);
+
+ else
+ png_free_default(png_ptr, ptr);
+}
+
+PNG_FUNCTION(void,PNGAPI
+png_free_default,(png_const_structrp png_ptr, png_voidp ptr),PNG_DEPRECATED)
+{
+ if (png_ptr == NULL || ptr == NULL)
+ return;
+#endif /* USER_MEM */
+
+ FXMEM_DefaultFree(ptr, 0);
+}
+
+#ifdef PNG_USER_MEM_SUPPORTED
+/* This function is called when the application wants to use another method
+ * of allocating and freeing memory.
+ */
+void PNGAPI
+png_set_mem_fn(png_structrp png_ptr, png_voidp mem_ptr, png_malloc_ptr
+ malloc_fn, png_free_ptr free_fn)
+{
+ if (png_ptr != NULL)
+ {
+ png_ptr->mem_ptr = mem_ptr;
+ png_ptr->malloc_fn = malloc_fn;
+ png_ptr->free_fn = free_fn;
+ }
+}
+
+/* This function returns a pointer to the mem_ptr associated with the user
+ * functions. The application should free any memory associated with this
+ * pointer before png_write_destroy and png_read_destroy are called.
+ */
+png_voidp PNGAPI
+png_get_mem_ptr(png_const_structrp png_ptr)
+{
+ if (png_ptr == NULL)
+ return NULL;
+
+ return png_ptr->mem_ptr;
+}
+#endif /* USER_MEM */
+#endif /* READ || WRITE */
diff --git a/third_party/lpng_v163/pngpread.c b/third_party/libpng/pngpread.c
similarity index 77%
rename from third_party/lpng_v163/pngpread.c
rename to third_party/libpng/pngpread.c
index afb2abf..89ffc40 100644
--- a/third_party/lpng_v163/pngpread.c
+++ b/third_party/libpng/pngpread.c
@@ -1,1290 +1,1085 @@
-/* pngpread.c - read a png file in push mode
- *
- * Last changed in libpng 1.6.0 [February 14, 2013]
- * Copyright (c) 1998-2013 Glenn Randers-Pehrson
- * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
- * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
- *
- * This code is released under the libpng license.
- * For conditions of distribution and use, see the disclaimer
- * and license in png.h
- */
-
-#include "pngpriv.h"
-
-#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
-
-/* Push model modes */
-#define PNG_READ_SIG_MODE 0
-#define PNG_READ_CHUNK_MODE 1
-#define PNG_READ_IDAT_MODE 2
-#define PNG_SKIP_MODE 3
-#define PNG_READ_tEXt_MODE 4
-#define PNG_READ_zTXt_MODE 5
-#define PNG_READ_DONE_MODE 6
-#define PNG_READ_iTXt_MODE 7
-#define PNG_ERROR_MODE 8
-
-void PNGAPI
-png_process_data(png_structrp png_ptr, png_inforp info_ptr,
- png_bytep buffer, png_size_t buffer_size)
-{
- if (png_ptr == NULL || info_ptr == NULL)
- return;
-
- png_push_restore_buffer(png_ptr, buffer, buffer_size);
-
- while (png_ptr->buffer_size)
- {
- png_process_some_data(png_ptr, info_ptr);
- }
-}
-
-png_size_t PNGAPI
-png_process_data_pause(png_structrp png_ptr, int save)
-{
- if (png_ptr != NULL)
- {
- /* It's easiest for the caller if we do the save, then the caller doesn't
- * have to supply the same data again:
- */
- if (save)
- png_push_save_buffer(png_ptr);
- else
- {
- /* This includes any pending saved bytes: */
- png_size_t remaining = png_ptr->buffer_size;
- png_ptr->buffer_size = 0;
-
- /* So subtract the saved buffer size, unless all the data
- * is actually 'saved', in which case we just return 0
- */
- if (png_ptr->save_buffer_size < remaining)
- return remaining - png_ptr->save_buffer_size;
- }
- }
-
- return 0;
-}
-
-png_uint_32 PNGAPI
-png_process_data_skip(png_structrp png_ptr)
-{
- png_uint_32 remaining = 0;
-
- if (png_ptr != NULL && png_ptr->process_mode == PNG_SKIP_MODE &&
- png_ptr->skip_length > 0)
- {
- /* At the end of png_process_data the buffer size must be 0 (see the loop
- * above) so we can detect a broken call here:
- */
- if (png_ptr->buffer_size != 0)
- png_error(png_ptr,
- "png_process_data_skip called inside png_process_data");
-
- /* If is impossible for there to be a saved buffer at this point -
- * otherwise we could not be in SKIP mode. This will also happen if
- * png_process_skip is called inside png_process_data (but only very
- * rarely.)
- */
- if (png_ptr->save_buffer_size != 0)
- png_error(png_ptr, "png_process_data_skip called with saved data");
-
- remaining = png_ptr->skip_length;
- png_ptr->skip_length = 0;
- png_ptr->process_mode = PNG_READ_CHUNK_MODE;
- }
-
- return remaining;
-}
-
-/* What we do with the incoming data depends on what we were previously
- * doing before we ran out of data...
- */
-void /* PRIVATE */
-png_process_some_data(png_structrp png_ptr, png_inforp info_ptr)
-{
- if (png_ptr == NULL)
- return;
-
- switch (png_ptr->process_mode)
- {
- case PNG_READ_SIG_MODE:
- {
- png_push_read_sig(png_ptr, info_ptr);
- break;
- }
-
- case PNG_READ_CHUNK_MODE:
- {
- png_push_read_chunk(png_ptr, info_ptr);
- break;
- }
-
- case PNG_READ_IDAT_MODE:
- {
- png_push_read_IDAT(png_ptr);
- break;
- }
-
- case PNG_SKIP_MODE:
- {
- png_push_crc_finish(png_ptr);
- break;
- }
-
- default:
- {
- png_ptr->buffer_size = 0;
- break;
- }
- }
-}
-
-/* Read any remaining signature bytes from the stream and compare them with
- * the correct PNG signature. It is possible that this routine is called
- * with bytes already read from the signature, either because they have been
- * checked by the calling application, or because of multiple calls to this
- * routine.
- */
-void /* PRIVATE */
-png_push_read_sig(png_structrp png_ptr, png_inforp info_ptr)
-{
- png_size_t num_checked = png_ptr->sig_bytes, /* SAFE, does not exceed 8 */
- num_to_check = 8 - num_checked;
-
- if (png_ptr->buffer_size < num_to_check)
- {
- num_to_check = png_ptr->buffer_size;
- }
-
- png_push_fill_buffer(png_ptr, &(info_ptr->signature[num_checked]),
- num_to_check);
- png_ptr->sig_bytes = (png_byte)(png_ptr->sig_bytes + num_to_check);
-
- if (png_sig_cmp(info_ptr->signature, num_checked, num_to_check))
- {
- if (num_checked < 4 &&
- png_sig_cmp(info_ptr->signature, num_checked, num_to_check - 4))
- png_error(png_ptr, "Not a PNG file");
-
- else
- png_error(png_ptr, "PNG file corrupted by ASCII conversion");
- }
- else
- {
- if (png_ptr->sig_bytes >= 8)
- {
- png_ptr->process_mode = PNG_READ_CHUNK_MODE;
- }
- }
-}
-
-void /* PRIVATE */
-png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
-{
- png_uint_32 chunk_name;
-#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
- int keep; /* unknown handling method */
-#endif
-
- /* First we make sure we have enough data for the 4 byte chunk name
- * and the 4 byte chunk length before proceeding with decoding the
- * chunk data. To fully decode each of these chunks, we also make
- * sure we have enough data in the buffer for the 4 byte CRC at the
- * end of every chunk (except IDAT, which is handled separately).
- */
- if (!(png_ptr->mode & PNG_HAVE_CHUNK_HEADER))
- {
- png_byte chunk_length[4];
- png_byte chunk_tag[4];
-
- if (png_ptr->buffer_size < 8)
- {
- png_push_save_buffer(png_ptr);
- return;
- }
-
- png_push_fill_buffer(png_ptr, chunk_length, 4);
- png_ptr->push_length = png_get_uint_31(png_ptr, chunk_length);
- png_reset_crc(png_ptr);
- png_crc_read(png_ptr, chunk_tag, 4);
- png_ptr->chunk_name = PNG_CHUNK_FROM_STRING(chunk_tag);
- png_check_chunk_name(png_ptr, png_ptr->chunk_name);
- png_ptr->mode |= PNG_HAVE_CHUNK_HEADER;
- }
-
- chunk_name = png_ptr->chunk_name;
-
- if (chunk_name == png_IDAT)
- {
- if (png_ptr->mode & PNG_AFTER_IDAT)
- png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT;
-
- /* If we reach an IDAT chunk, this means we have read all of the
- * header chunks, and we can start reading the image (or if this
- * is called after the image has been read - we have an error).
- */
- if (!(png_ptr->mode & PNG_HAVE_IHDR))
- png_error(png_ptr, "Missing IHDR before IDAT");
-
- else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
- !(png_ptr->mode & PNG_HAVE_PLTE))
- png_error(png_ptr, "Missing PLTE before IDAT");
-
- png_ptr->mode |= PNG_HAVE_IDAT;
-
- if (!(png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT))
- if (png_ptr->push_length == 0)
- return;
-
- if (png_ptr->mode & PNG_AFTER_IDAT)
- png_benign_error(png_ptr, "Too many IDATs found");
- }
-
- if (chunk_name == png_IHDR)
- {
- if (png_ptr->push_length != 13)
- png_error(png_ptr, "Invalid IHDR length");
-
- if (png_ptr->push_length + 4 > png_ptr->buffer_size)
- {
- png_push_save_buffer(png_ptr);
- return;
- }
-
- png_handle_IHDR(png_ptr, info_ptr, png_ptr->push_length);
- }
-
- else if (chunk_name == png_IEND)
- {
- if (png_ptr->push_length + 4 > png_ptr->buffer_size)
- {
- png_push_save_buffer(png_ptr);
- return;
- }
-
- png_handle_IEND(png_ptr, info_ptr, png_ptr->push_length);
-
- png_ptr->process_mode = PNG_READ_DONE_MODE;
- png_push_have_end(png_ptr, info_ptr);
- }
-
-#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
- else if ((keep = png_chunk_unknown_handling(png_ptr, chunk_name)) != 0)
- {
- if (png_ptr->push_length + 4 > png_ptr->buffer_size)
- {
- png_push_save_buffer(png_ptr);
- return;
- }
-
- png_handle_unknown(png_ptr, info_ptr, png_ptr->push_length, keep);
-
- if (chunk_name == png_PLTE)
- png_ptr->mode |= PNG_HAVE_PLTE;
- }
-
-#endif
- else if (chunk_name == png_PLTE)
- {
- if (png_ptr->push_length + 4 > png_ptr->buffer_size)
- {
- png_push_save_buffer(png_ptr);
- return;
- }
- png_handle_PLTE(png_ptr, info_ptr, png_ptr->push_length);
- }
-
- else if (chunk_name == png_IDAT)
- {
- png_ptr->idat_size = png_ptr->push_length;
- png_ptr->process_mode = PNG_READ_IDAT_MODE;
- png_push_have_info(png_ptr, info_ptr);
- png_ptr->zstream.avail_out =
- (uInt) PNG_ROWBYTES(png_ptr->pixel_depth,
- png_ptr->iwidth) + 1;
- png_ptr->zstream.next_out = png_ptr->row_buf;
- return;
- }
-
-#ifdef PNG_READ_gAMA_SUPPORTED
- else if (png_ptr->chunk_name == png_gAMA)
- {
- if (png_ptr->push_length + 4 > png_ptr->buffer_size)
- {
- png_push_save_buffer(png_ptr);
- return;
- }
-
- png_handle_gAMA(png_ptr, info_ptr, png_ptr->push_length);
- }
-
-#endif
-#ifdef PNG_READ_sBIT_SUPPORTED
- else if (png_ptr->chunk_name == png_sBIT)
- {
- if (png_ptr->push_length + 4 > png_ptr->buffer_size)
- {
- png_push_save_buffer(png_ptr);
- return;
- }
-
- png_handle_sBIT(png_ptr, info_ptr, png_ptr->push_length);
- }
-
-#endif
-#ifdef PNG_READ_cHRM_SUPPORTED
- else if (png_ptr->chunk_name == png_cHRM)
- {
- if (png_ptr->push_length + 4 > png_ptr->buffer_size)
- {
- png_push_save_buffer(png_ptr);
- return;
- }
-
- png_handle_cHRM(png_ptr, info_ptr, png_ptr->push_length);
- }
-
-#endif
-#ifdef PNG_READ_sRGB_SUPPORTED
- else if (chunk_name == png_sRGB)
- {
- if (png_ptr->push_length + 4 > png_ptr->buffer_size)
- {
- png_push_save_buffer(png_ptr);
- return;
- }
-
- png_handle_sRGB(png_ptr, info_ptr, png_ptr->push_length);
- }
-
-#endif
-#ifdef PNG_READ_iCCP_SUPPORTED
- else if (png_ptr->chunk_name == png_iCCP)
- {
- if (png_ptr->push_length + 4 > png_ptr->buffer_size)
- {
- png_push_save_buffer(png_ptr);
- return;
- }
-
- png_handle_iCCP(png_ptr, info_ptr, png_ptr->push_length);
- }
-
-#endif
-#ifdef PNG_READ_sPLT_SUPPORTED
- else if (chunk_name == png_sPLT)
- {
- if (png_ptr->push_length + 4 > png_ptr->buffer_size)
- {
- png_push_save_buffer(png_ptr);
- return;
- }
-
- png_handle_sPLT(png_ptr, info_ptr, png_ptr->push_length);
- }
-
-#endif
-#ifdef PNG_READ_tRNS_SUPPORTED
- else if (chunk_name == png_tRNS)
- {
- if (png_ptr->push_length + 4 > png_ptr->buffer_size)
- {
- png_push_save_buffer(png_ptr);
- return;
- }
-
- png_handle_tRNS(png_ptr, info_ptr, png_ptr->push_length);
- }
-
-#endif
-#ifdef PNG_READ_bKGD_SUPPORTED
- else if (chunk_name == png_bKGD)
- {
- if (png_ptr->push_length + 4 > png_ptr->buffer_size)
- {
- png_push_save_buffer(png_ptr);
- return;
- }
-
- png_handle_bKGD(png_ptr, info_ptr, png_ptr->push_length);
- }
-
-#endif
-#ifdef PNG_READ_hIST_SUPPORTED
- else if (chunk_name == png_hIST)
- {
- if (png_ptr->push_length + 4 > png_ptr->buffer_size)
- {
- png_push_save_buffer(png_ptr);
- return;
- }
-
- png_handle_hIST(png_ptr, info_ptr, png_ptr->push_length);
- }
-
-#endif
-#ifdef PNG_READ_pHYs_SUPPORTED
- else if (chunk_name == png_pHYs)
- {
- if (png_ptr->push_length + 4 > png_ptr->buffer_size)
- {
- png_push_save_buffer(png_ptr);
- return;
- }
-
- png_handle_pHYs(png_ptr, info_ptr, png_ptr->push_length);
- }
-
-#endif
-#ifdef PNG_READ_oFFs_SUPPORTED
- else if (chunk_name == png_oFFs)
- {
- if (png_ptr->push_length + 4 > png_ptr->buffer_size)
- {
- png_push_save_buffer(png_ptr);
- return;
- }
-
- png_handle_oFFs(png_ptr, info_ptr, png_ptr->push_length);
- }
-#endif
-
-#ifdef PNG_READ_pCAL_SUPPORTED
- else if (chunk_name == png_pCAL)
- {
- if (png_ptr->push_length + 4 > png_ptr->buffer_size)
- {
- png_push_save_buffer(png_ptr);
- return;
- }
-
- png_handle_pCAL(png_ptr, info_ptr, png_ptr->push_length);
- }
-
-#endif
-#ifdef PNG_READ_sCAL_SUPPORTED
- else if (chunk_name == png_sCAL)
- {
- if (png_ptr->push_length + 4 > png_ptr->buffer_size)
- {
- png_push_save_buffer(png_ptr);
- return;
- }
-
- png_handle_sCAL(png_ptr, info_ptr, png_ptr->push_length);
- }
-
-#endif
-#ifdef PNG_READ_tIME_SUPPORTED
- else if (chunk_name == png_tIME)
- {
- if (png_ptr->push_length + 4 > png_ptr->buffer_size)
- {
- png_push_save_buffer(png_ptr);
- return;
- }
-
- png_handle_tIME(png_ptr, info_ptr, png_ptr->push_length);
- }
-
-#endif
-#ifdef PNG_READ_tEXt_SUPPORTED
- else if (chunk_name == png_tEXt)
- {
- if (png_ptr->push_length + 4 > png_ptr->buffer_size)
- {
- png_push_save_buffer(png_ptr);
- return;
- }
-
- png_handle_tEXt(png_ptr, info_ptr, png_ptr->push_length);
- }
-
-#endif
-#ifdef PNG_READ_zTXt_SUPPORTED
- else if (chunk_name == png_zTXt)
- {
- if (png_ptr->push_length + 4 > png_ptr->buffer_size)
- {
- png_push_save_buffer(png_ptr);
- return;
- }
-
- png_handle_zTXt(png_ptr, info_ptr, png_ptr->push_length);
- }
-
-#endif
-#ifdef PNG_READ_iTXt_SUPPORTED
- else if (chunk_name == png_iTXt)
- {
- if (png_ptr->push_length + 4 > png_ptr->buffer_size)
- {
- png_push_save_buffer(png_ptr);
- return;
- }
-
- png_handle_iTXt(png_ptr, info_ptr, png_ptr->push_length);
- }
-
-#endif
- else
- {
- if (png_ptr->push_length + 4 > png_ptr->buffer_size)
- {
- png_push_save_buffer(png_ptr);
- return;
- }
- png_handle_unknown(png_ptr, info_ptr, png_ptr->push_length,
- PNG_HANDLE_CHUNK_AS_DEFAULT);
- }
-
- png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
-}
-
-void /* PRIVATE */
-png_push_crc_skip(png_structrp png_ptr, png_uint_32 skip)
-{
- png_ptr->process_mode = PNG_SKIP_MODE;
- png_ptr->skip_length = skip;
-}
-
-void /* PRIVATE */
-png_push_crc_finish(png_structrp png_ptr)
-{
- if (png_ptr->skip_length && png_ptr->save_buffer_size)
- {
- png_size_t save_size = png_ptr->save_buffer_size;
- png_uint_32 skip_length = png_ptr->skip_length;
-
- /* We want the smaller of 'skip_length' and 'save_buffer_size', but
- * they are of different types and we don't know which variable has the
- * fewest bits. Carefully select the smaller and cast it to the type of
- * the larger - this cannot overflow. Do not cast in the following test
- * - it will break on either 16 or 64 bit platforms.
- */
- if (skip_length < save_size)
- save_size = (png_size_t)skip_length;
-
- else
- skip_length = (png_uint_32)save_size;
-
- png_calculate_crc(png_ptr, png_ptr->save_buffer_ptr, save_size);
-
- png_ptr->skip_length -= skip_length;
- png_ptr->buffer_size -= save_size;
- png_ptr->save_buffer_size -= save_size;
- png_ptr->save_buffer_ptr += save_size;
- }
- if (png_ptr->skip_length && png_ptr->current_buffer_size)
- {
- png_size_t save_size = png_ptr->current_buffer_size;
- png_uint_32 skip_length = png_ptr->skip_length;
-
- /* We want the smaller of 'skip_length' and 'current_buffer_size', here,
- * the same problem exists as above and the same solution.
- */
- if (skip_length < save_size)
- save_size = (png_size_t)skip_length;
-
- else
- skip_length = (png_uint_32)save_size;
-
- png_calculate_crc(png_ptr, png_ptr->current_buffer_ptr, save_size);
-
- png_ptr->skip_length -= skip_length;
- png_ptr->buffer_size -= save_size;
- png_ptr->current_buffer_size -= save_size;
- png_ptr->current_buffer_ptr += save_size;
- }
- if (!png_ptr->skip_length)
- {
- if (png_ptr->buffer_size < 4)
- {
- png_push_save_buffer(png_ptr);
- return;
- }
-
- png_crc_finish(png_ptr, 0);
- png_ptr->process_mode = PNG_READ_CHUNK_MODE;
- }
-}
-
-void PNGCBAPI
-png_push_fill_buffer(png_structp png_ptr, png_bytep buffer, png_size_t length)
-{
- png_bytep ptr;
-
- if (png_ptr == NULL)
- return;
-
- ptr = buffer;
- if (png_ptr->save_buffer_size)
- {
- png_size_t save_size;
-
- if (length < png_ptr->save_buffer_size)
- save_size = length;
-
- else
- save_size = png_ptr->save_buffer_size;
-
- memcpy(ptr, png_ptr->save_buffer_ptr, save_size);
- length -= save_size;
- ptr += save_size;
- png_ptr->buffer_size -= save_size;
- png_ptr->save_buffer_size -= save_size;
- png_ptr->save_buffer_ptr += save_size;
- }
- if (length && png_ptr->current_buffer_size)
- {
- png_size_t save_size;
-
- if (length < png_ptr->current_buffer_size)
- save_size = length;
-
- else
- save_size = png_ptr->current_buffer_size;
-
- memcpy(ptr, png_ptr->current_buffer_ptr, save_size);
- png_ptr->buffer_size -= save_size;
- png_ptr->current_buffer_size -= save_size;
- png_ptr->current_buffer_ptr += save_size;
- }
-}
-
-void /* PRIVATE */
-png_push_save_buffer(png_structrp png_ptr)
-{
- if (png_ptr->save_buffer_size)
- {
- if (png_ptr->save_buffer_ptr != png_ptr->save_buffer)
- {
- png_size_t i, istop;
- png_bytep sp;
- png_bytep dp;
-
- istop = png_ptr->save_buffer_size;
- for (i = 0, sp = png_ptr->save_buffer_ptr, dp = png_ptr->save_buffer;
- i < istop; i++, sp++, dp++)
- {
- *dp = *sp;
- }
- }
- }
- if (png_ptr->save_buffer_size + png_ptr->current_buffer_size >
- png_ptr->save_buffer_max)
- {
- png_size_t new_max;
- png_bytep old_buffer;
-
- if (png_ptr->save_buffer_size > PNG_SIZE_MAX -
- (png_ptr->current_buffer_size + 256))
- {
- png_error(png_ptr, "Potential overflow of save_buffer");
- }
-
- new_max = png_ptr->save_buffer_size + png_ptr->current_buffer_size + 256;
- old_buffer = png_ptr->save_buffer;
- png_ptr->save_buffer = (png_bytep)png_malloc_warn(png_ptr,
- (png_size_t)new_max);
-
- if (png_ptr->save_buffer == NULL)
- {
- png_free(png_ptr, old_buffer);
- png_error(png_ptr, "Insufficient memory for save_buffer");
- }
-
- memcpy(png_ptr->save_buffer, old_buffer, png_ptr->save_buffer_size);
- png_free(png_ptr, old_buffer);
- png_ptr->save_buffer_max = new_max;
- }
- if (png_ptr->current_buffer_size)
- {
- memcpy(png_ptr->save_buffer + png_ptr->save_buffer_size,
- png_ptr->current_buffer_ptr, png_ptr->current_buffer_size);
- png_ptr->save_buffer_size += png_ptr->current_buffer_size;
- png_ptr->current_buffer_size = 0;
- }
- png_ptr->save_buffer_ptr = png_ptr->save_buffer;
- png_ptr->buffer_size = 0;
-}
-
-void /* PRIVATE */
-png_push_restore_buffer(png_structrp png_ptr, png_bytep buffer,
- png_size_t buffer_length)
-{
- png_ptr->current_buffer = buffer;
- png_ptr->current_buffer_size = buffer_length;
- png_ptr->buffer_size = buffer_length + png_ptr->save_buffer_size;
- png_ptr->current_buffer_ptr = png_ptr->current_buffer;
-}
-
-void /* PRIVATE */
-png_push_read_IDAT(png_structrp png_ptr)
-{
- if (!(png_ptr->mode & PNG_HAVE_CHUNK_HEADER))
- {
- png_byte chunk_length[4];
- png_byte chunk_tag[4];
-
- /* TODO: this code can be commoned up with the same code in push_read */
- if (png_ptr->buffer_size < 8)
- {
- png_push_save_buffer(png_ptr);
- return;
- }
-
- png_push_fill_buffer(png_ptr, chunk_length, 4);
- png_ptr->push_length = png_get_uint_31(png_ptr, chunk_length);
- png_reset_crc(png_ptr);
- png_crc_read(png_ptr, chunk_tag, 4);
- png_ptr->chunk_name = PNG_CHUNK_FROM_STRING(chunk_tag);
- png_ptr->mode |= PNG_HAVE_CHUNK_HEADER;
-
- if (png_ptr->chunk_name != png_IDAT)
- {
- png_ptr->process_mode = PNG_READ_CHUNK_MODE;
-
- if (!(png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED))
- png_error(png_ptr, "Not enough compressed data");
-
- return;
- }
-
- png_ptr->idat_size = png_ptr->push_length;
- }
-
- if (png_ptr->idat_size && png_ptr->save_buffer_size)
- {
- png_size_t save_size = png_ptr->save_buffer_size;
- png_uint_32 idat_size = png_ptr->idat_size;
-
- /* We want the smaller of 'idat_size' and 'current_buffer_size', but they
- * are of different types and we don't know which variable has the fewest
- * bits. Carefully select the smaller and cast it to the type of the
- * larger - this cannot overflow. Do not cast in the following test - it
- * will break on either 16 or 64 bit platforms.
- */
- if (idat_size < save_size)
- save_size = (png_size_t)idat_size;
-
- else
- idat_size = (png_uint_32)save_size;
-
- png_calculate_crc(png_ptr, png_ptr->save_buffer_ptr, save_size);
-
- png_process_IDAT_data(png_ptr, png_ptr->save_buffer_ptr, save_size);
-
- png_ptr->idat_size -= idat_size;
- png_ptr->buffer_size -= save_size;
- png_ptr->save_buffer_size -= save_size;
- png_ptr->save_buffer_ptr += save_size;
- }
-
- if (png_ptr->idat_size && png_ptr->current_buffer_size)
- {
- png_size_t save_size = png_ptr->current_buffer_size;
- png_uint_32 idat_size = png_ptr->idat_size;
-
- /* We want the smaller of 'idat_size' and 'current_buffer_size', but they
- * are of different types and we don't know which variable has the fewest
- * bits. Carefully select the smaller and cast it to the type of the
- * larger - this cannot overflow.
- */
- if (idat_size < save_size)
- save_size = (png_size_t)idat_size;
-
- else
- idat_size = (png_uint_32)save_size;
-
- png_calculate_crc(png_ptr, png_ptr->current_buffer_ptr, save_size);
-
- png_process_IDAT_data(png_ptr, png_ptr->current_buffer_ptr, save_size);
-
- png_ptr->idat_size -= idat_size;
- png_ptr->buffer_size -= save_size;
- png_ptr->current_buffer_size -= save_size;
- png_ptr->current_buffer_ptr += save_size;
- }
- if (!png_ptr->idat_size)
- {
- if (png_ptr->buffer_size < 4)
- {
- png_push_save_buffer(png_ptr);
- return;
- }
-
- png_crc_finish(png_ptr, 0);
- png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
- png_ptr->mode |= PNG_AFTER_IDAT;
- png_ptr->zowner = 0;
- }
-}
-
-void /* PRIVATE */
-png_process_IDAT_data(png_structrp png_ptr, png_bytep buffer,
- png_size_t buffer_length)
-{
- /* The caller checks for a non-zero buffer length. */
- if (!(buffer_length > 0) || buffer == NULL)
- png_error(png_ptr, "No IDAT data (internal error)");
-
- /* This routine must process all the data it has been given
- * before returning, calling the row callback as required to
- * handle the uncompressed results.
- */
- png_ptr->zstream.next_in = buffer;
- /* TODO: WARNING: TRUNCATION ERROR: DANGER WILL ROBINSON: */
- png_ptr->zstream.avail_in = (uInt)buffer_length;
-
- /* Keep going until the decompressed data is all processed
- * or the stream marked as finished.
- */
- while (png_ptr->zstream.avail_in > 0 &&
- !(png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED))
- {
- int ret;
-
- /* We have data for zlib, but we must check that zlib
- * has someplace to put the results. It doesn't matter
- * if we don't expect any results -- it may be the input
- * data is just the LZ end code.
- */
- if (!(png_ptr->zstream.avail_out > 0))
- {
- /* TODO: WARNING: TRUNCATION ERROR: DANGER WILL ROBINSON: */
- png_ptr->zstream.avail_out = (uInt)(PNG_ROWBYTES(png_ptr->pixel_depth,
- png_ptr->iwidth) + 1);
-
- png_ptr->zstream.next_out = png_ptr->row_buf;
- }
-
- /* Using Z_SYNC_FLUSH here means that an unterminated
- * LZ stream (a stream with a missing end code) can still
- * be handled, otherwise (Z_NO_FLUSH) a future zlib
- * implementation might defer output and therefore
- * change the current behavior (see comments in inflate.c
- * for why this doesn't happen at present with zlib 1.2.5).
- */
- ret = inflate(&png_ptr->zstream, Z_SYNC_FLUSH);
-
- /* Check for any failure before proceeding. */
- if (ret != Z_OK && ret != Z_STREAM_END)
- {
- /* Terminate the decompression. */
- png_ptr->flags |= PNG_FLAG_ZSTREAM_ENDED;
- png_ptr->zowner = 0;
-
- /* This may be a truncated stream (missing or
- * damaged end code). Treat that as a warning.
- */
- if (png_ptr->row_number >= png_ptr->num_rows ||
- png_ptr->pass > 6)
- png_warning(png_ptr, "Truncated compressed data in IDAT");
-
- else
- png_error(png_ptr, "Decompression error in IDAT");
-
- /* Skip the check on unprocessed input */
- return;
- }
-
- /* Did inflate output any data? */
- if (png_ptr->zstream.next_out != png_ptr->row_buf)
- {
- /* Is this unexpected data after the last row?
- * If it is, artificially terminate the LZ output
- * here.
- */
- if (png_ptr->row_number >= png_ptr->num_rows ||
- png_ptr->pass > 6)
- {
- /* Extra data. */
- png_warning(png_ptr, "Extra compressed data in IDAT");
- png_ptr->flags |= PNG_FLAG_ZSTREAM_ENDED;
- png_ptr->zowner = 0;
-
- /* Do no more processing; skip the unprocessed
- * input check below.
- */
- return;
- }
-
- /* Do we have a complete row? */
- if (png_ptr->zstream.avail_out == 0)
- png_push_process_row(png_ptr);
- }
-
- /* And check for the end of the stream. */
- if (ret == Z_STREAM_END)
- png_ptr->flags |= PNG_FLAG_ZSTREAM_ENDED;
- }
-
- /* All the data should have been processed, if anything
- * is left at this point we have bytes of IDAT data
- * after the zlib end code.
- */
- if (png_ptr->zstream.avail_in > 0)
- png_warning(png_ptr, "Extra compression data in IDAT");
-}
-
-void /* PRIVATE */
-png_push_process_row(png_structrp png_ptr)
-{
- /* 1.5.6: row_info moved out of png_struct to a local here. */
- png_row_info row_info;
-
- row_info.width = png_ptr->iwidth; /* NOTE: width of current interlaced row */
- row_info.color_type = png_ptr->color_type;
- row_info.bit_depth = png_ptr->bit_depth;
- row_info.channels = png_ptr->channels;
- row_info.pixel_depth = png_ptr->pixel_depth;
- row_info.rowbytes = PNG_ROWBYTES(row_info.pixel_depth, row_info.width);
-
- if (png_ptr->row_buf[0] > PNG_FILTER_VALUE_NONE)
- {
- if (png_ptr->row_buf[0] < PNG_FILTER_VALUE_LAST)
- png_read_filter_row(png_ptr, &row_info, png_ptr->row_buf + 1,
- png_ptr->prev_row + 1, png_ptr->row_buf[0]);
- else
- png_error(png_ptr, "bad adaptive filter value");
- }
-
- /* libpng 1.5.6: the following line was copying png_ptr->rowbytes before
- * 1.5.6, while the buffer really is this big in current versions of libpng
- * it may not be in the future, so this was changed just to copy the
- * interlaced row count:
- */
- memcpy(png_ptr->prev_row, png_ptr->row_buf, row_info.rowbytes + 1);
-
-#ifdef PNG_READ_TRANSFORMS_SUPPORTED
- if (png_ptr->transformations)
- png_do_read_transformations(png_ptr, &row_info);
-#endif
-
- /* The transformed pixel depth should match the depth now in row_info. */
- if (png_ptr->transformed_pixel_depth == 0)
- {
- png_ptr->transformed_pixel_depth = row_info.pixel_depth;
- if (row_info.pixel_depth > png_ptr->maximum_pixel_depth)
- png_error(png_ptr, "progressive row overflow");
- }
-
- else if (png_ptr->transformed_pixel_depth != row_info.pixel_depth)
- png_error(png_ptr, "internal progressive row size calculation error");
-
-
-#ifdef PNG_READ_INTERLACING_SUPPORTED
- /* Blow up interlaced rows to full size */
- if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE))
- {
- if (png_ptr->pass < 6)
- png_do_read_interlace(&row_info, png_ptr->row_buf + 1, png_ptr->pass,
- png_ptr->transformations);
-
- switch (png_ptr->pass)
- {
- case 0:
- {
- int i;
- for (i = 0; i < 8 && png_ptr->pass == 0; i++)
- {
- png_push_have_row(png_ptr, png_ptr->row_buf + 1);
- png_read_push_finish_row(png_ptr); /* Updates png_ptr->pass */
- }
-
- if (png_ptr->pass == 2) /* Pass 1 might be empty */
- {
- for (i = 0; i < 4 && png_ptr->pass == 2; i++)
- {
- png_push_have_row(png_ptr, NULL);
- png_read_push_finish_row(png_ptr);
- }
- }
-
- if (png_ptr->pass == 4 && png_ptr->height <= 4)
- {
- for (i = 0; i < 2 && png_ptr->pass == 4; i++)
- {
- png_push_have_row(png_ptr, NULL);
- png_read_push_finish_row(png_ptr);
- }
- }
-
- if (png_ptr->pass == 6 && png_ptr->height <= 4)
- {
- png_push_have_row(png_ptr, NULL);
- png_read_push_finish_row(png_ptr);
- }
-
- break;
- }
-
- case 1:
- {
- int i;
- for (i = 0; i < 8 && png_ptr->pass == 1; i++)
- {
- png_push_have_row(png_ptr, png_ptr->row_buf + 1);
- png_read_push_finish_row(png_ptr);
- }
-
- if (png_ptr->pass == 2) /* Skip top 4 generated rows */
- {
- for (i = 0; i < 4 && png_ptr->pass == 2; i++)
- {
- png_push_have_row(png_ptr, NULL);
- png_read_push_finish_row(png_ptr);
- }
- }
-
- break;
- }
-
- case 2:
- {
- int i;
-
- for (i = 0; i < 4 && png_ptr->pass == 2; i++)
- {
- png_push_have_row(png_ptr, png_ptr->row_buf + 1);
- png_read_push_finish_row(png_ptr);
- }
-
- for (i = 0; i < 4 && png_ptr->pass == 2; i++)
- {
- png_push_have_row(png_ptr, NULL);
- png_read_push_finish_row(png_ptr);
- }
-
- if (png_ptr->pass == 4) /* Pass 3 might be empty */
- {
- for (i = 0; i < 2 && png_ptr->pass == 4; i++)
- {
- png_push_have_row(png_ptr, NULL);
- png_read_push_finish_row(png_ptr);
- }
- }
-
- break;
- }
-
- case 3:
- {
- int i;
-
- for (i = 0; i < 4 && png_ptr->pass == 3; i++)
- {
- png_push_have_row(png_ptr, png_ptr->row_buf + 1);
- png_read_push_finish_row(png_ptr);
- }
-
- if (png_ptr->pass == 4) /* Skip top two generated rows */
- {
- for (i = 0; i < 2 && png_ptr->pass == 4; i++)
- {
- png_push_have_row(png_ptr, NULL);
- png_read_push_finish_row(png_ptr);
- }
- }
-
- break;
- }
-
- case 4:
- {
- int i;
-
- for (i = 0; i < 2 && png_ptr->pass == 4; i++)
- {
- png_push_have_row(png_ptr, png_ptr->row_buf + 1);
- png_read_push_finish_row(png_ptr);
- }
-
- for (i = 0; i < 2 && png_ptr->pass == 4; i++)
- {
- png_push_have_row(png_ptr, NULL);
- png_read_push_finish_row(png_ptr);
- }
-
- if (png_ptr->pass == 6) /* Pass 5 might be empty */
- {
- png_push_have_row(png_ptr, NULL);
- png_read_push_finish_row(png_ptr);
- }
-
- break;
- }
-
- case 5:
- {
- int i;
-
- for (i = 0; i < 2 && png_ptr->pass == 5; i++)
- {
- png_push_have_row(png_ptr, png_ptr->row_buf + 1);
- png_read_push_finish_row(png_ptr);
- }
-
- if (png_ptr->pass == 6) /* Skip top generated row */
- {
- png_push_have_row(png_ptr, NULL);
- png_read_push_finish_row(png_ptr);
- }
-
- break;
- }
-
- default:
- case 6:
- {
- png_push_have_row(png_ptr, png_ptr->row_buf + 1);
- png_read_push_finish_row(png_ptr);
-
- if (png_ptr->pass != 6)
- break;
-
- png_push_have_row(png_ptr, NULL);
- png_read_push_finish_row(png_ptr);
- }
- }
- }
- else
-#endif
- {
- png_push_have_row(png_ptr, png_ptr->row_buf + 1);
- png_read_push_finish_row(png_ptr);
- }
-}
-
-void /* PRIVATE */
-png_read_push_finish_row(png_structrp png_ptr)
-{
-#ifdef PNG_READ_INTERLACING_SUPPORTED
- /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
-
- /* Start of interlace block */
- static PNG_CONST png_byte png_pass_start[] = {0, 4, 0, 2, 0, 1, 0};
-
- /* Offset to next interlace block */
- static PNG_CONST png_byte png_pass_inc[] = {8, 8, 4, 4, 2, 2, 1};
-
- /* Start of interlace block in the y direction */
- static PNG_CONST png_byte png_pass_ystart[] = {0, 0, 4, 0, 2, 0, 1};
-
- /* Offset to next interlace block in the y direction */
- static PNG_CONST png_byte png_pass_yinc[] = {8, 8, 8, 4, 4, 2, 2};
-
- /* Height of interlace block. This is not currently used - if you need
- * it, uncomment it here and in png.h
- static PNG_CONST png_byte png_pass_height[] = {8, 8, 4, 4, 2, 2, 1};
- */
-#endif
-
- png_ptr->row_number++;
- if (png_ptr->row_number < png_ptr->num_rows)
- return;
-
-#ifdef PNG_READ_INTERLACING_SUPPORTED
- if (png_ptr->interlaced)
- {
- png_ptr->row_number = 0;
- memset(png_ptr->prev_row, 0, png_ptr->rowbytes + 1);
-
- do
- {
- png_ptr->pass++;
- if ((png_ptr->pass == 1 && png_ptr->width < 5) ||
- (png_ptr->pass == 3 && png_ptr->width < 3) ||
- (png_ptr->pass == 5 && png_ptr->width < 2))
- png_ptr->pass++;
-
- if (png_ptr->pass > 7)
- png_ptr->pass--;
-
- if (png_ptr->pass >= 7)
- break;
-
- png_ptr->iwidth = (png_ptr->width +
- png_pass_inc[png_ptr->pass] - 1 -
- png_pass_start[png_ptr->pass]) /
- png_pass_inc[png_ptr->pass];
-
- if (png_ptr->transformations & PNG_INTERLACE)
- break;
-
- png_ptr->num_rows = (png_ptr->height +
- png_pass_yinc[png_ptr->pass] - 1 -
- png_pass_ystart[png_ptr->pass]) /
- png_pass_yinc[png_ptr->pass];
-
- } while (png_ptr->iwidth == 0 || png_ptr->num_rows == 0);
- }
-#endif /* PNG_READ_INTERLACING_SUPPORTED */
-}
-
-void /* PRIVATE */
-png_push_have_info(png_structrp png_ptr, png_inforp info_ptr)
-{
- if (png_ptr->info_fn != NULL)
- (*(png_ptr->info_fn))(png_ptr, info_ptr);
-}
-
-void /* PRIVATE */
-png_push_have_end(png_structrp png_ptr, png_inforp info_ptr)
-{
- if (png_ptr->end_fn != NULL)
- (*(png_ptr->end_fn))(png_ptr, info_ptr);
-}
-
-void /* PRIVATE */
-png_push_have_row(png_structrp png_ptr, png_bytep row)
-{
- if (png_ptr->row_fn != NULL)
- (*(png_ptr->row_fn))(png_ptr, row, png_ptr->row_number,
- (int)png_ptr->pass);
-}
-
-#ifdef PNG_READ_INTERLACING_SUPPORTED
-void PNGAPI
-png_progressive_combine_row(png_const_structrp png_ptr, png_bytep old_row,
- png_const_bytep new_row)
-{
- if (png_ptr == NULL)
- return;
-
- /* new_row is a flag here - if it is NULL then the app callback was called
- * from an empty row (see the calls to png_struct::row_fn below), otherwise
- * it must be png_ptr->row_buf+1
- */
- if (new_row != NULL)
- png_combine_row(png_ptr, old_row, 1/*display*/);
-}
-#endif /* PNG_READ_INTERLACING_SUPPORTED */
-
-void PNGAPI
-png_set_progressive_read_fn(png_structrp png_ptr, png_voidp progressive_ptr,
- png_progressive_info_ptr info_fn, png_progressive_row_ptr row_fn,
- png_progressive_end_ptr end_fn)
-{
- if (png_ptr == NULL)
- return;
-
- png_ptr->info_fn = info_fn;
- png_ptr->row_fn = row_fn;
- png_ptr->end_fn = end_fn;
-
- png_set_read_fn(png_ptr, progressive_ptr, png_push_fill_buffer);
-}
-
-png_voidp PNGAPI
-png_get_progressive_ptr(png_const_structrp png_ptr)
-{
- if (png_ptr == NULL)
- return (NULL);
-
- return png_ptr->io_ptr;
-}
-#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
+
+/* pngpread.c - read a png file in push mode
+ *
+ * Last changed in libpng 1.6.18 [July 23, 2015]
+ * Copyright (c) 1998-2015 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+
+#include "pngpriv.h"
+
+#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
+
+/* Push model modes */
+#define PNG_READ_SIG_MODE 0
+#define PNG_READ_CHUNK_MODE 1
+#define PNG_READ_IDAT_MODE 2
+#define PNG_READ_tEXt_MODE 4
+#define PNG_READ_zTXt_MODE 5
+#define PNG_READ_DONE_MODE 6
+#define PNG_READ_iTXt_MODE 7
+#define PNG_ERROR_MODE 8
+
+#define PNG_PUSH_SAVE_BUFFER_IF_FULL \
+if (png_ptr->push_length + 4 > png_ptr->buffer_size) \
+ { png_push_save_buffer(png_ptr); return; }
+#define PNG_PUSH_SAVE_BUFFER_IF_LT(N) \
+if (png_ptr->buffer_size < N) \
+ { png_push_save_buffer(png_ptr); return; }
+
+void PNGAPI
+png_process_data(png_structrp png_ptr, png_inforp info_ptr,
+ png_bytep buffer, png_size_t buffer_size)
+{
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+ png_push_restore_buffer(png_ptr, buffer, buffer_size);
+
+ while (png_ptr->buffer_size)
+ {
+ png_process_some_data(png_ptr, info_ptr);
+ }
+}
+
+png_size_t PNGAPI
+png_process_data_pause(png_structrp png_ptr, int save)
+{
+ if (png_ptr != NULL)
+ {
+ /* It's easiest for the caller if we do the save; then the caller doesn't
+ * have to supply the same data again:
+ */
+ if (save != 0)
+ png_push_save_buffer(png_ptr);
+ else
+ {
+ /* This includes any pending saved bytes: */
+ png_size_t remaining = png_ptr->buffer_size;
+ png_ptr->buffer_size = 0;
+
+ /* So subtract the saved buffer size, unless all the data
+ * is actually 'saved', in which case we just return 0
+ */
+ if (png_ptr->save_buffer_size < remaining)
+ return remaining - png_ptr->save_buffer_size;
+ }
+ }
+
+ return 0;
+}
+
+png_uint_32 PNGAPI
+png_process_data_skip(png_structrp png_ptr)
+{
+ /* TODO: Deprecate and remove this API.
+ * Somewhere the implementation of this seems to have been lost,
+ * or abandoned. It was only to support some internal back-door access
+ * to png_struct) in libpng-1.4.x.
+ */
+ png_app_warning(png_ptr,
+"png_process_data_skip is not implemented in any current version of libpng");
+ return 0;
+}
+
+/* What we do with the incoming data depends on what we were previously
+ * doing before we ran out of data...
+ */
+void /* PRIVATE */
+png_process_some_data(png_structrp png_ptr, png_inforp info_ptr)
+{
+ if (png_ptr == NULL)
+ return;
+
+ switch (png_ptr->process_mode)
+ {
+ case PNG_READ_SIG_MODE:
+ {
+ png_push_read_sig(png_ptr, info_ptr);
+ break;
+ }
+
+ case PNG_READ_CHUNK_MODE:
+ {
+ png_push_read_chunk(png_ptr, info_ptr);
+ break;
+ }
+
+ case PNG_READ_IDAT_MODE:
+ {
+ png_push_read_IDAT(png_ptr);
+ break;
+ }
+
+ default:
+ {
+ png_ptr->buffer_size = 0;
+ break;
+ }
+ }
+}
+
+/* Read any remaining signature bytes from the stream and compare them with
+ * the correct PNG signature. It is possible that this routine is called
+ * with bytes already read from the signature, either because they have been
+ * checked by the calling application, or because of multiple calls to this
+ * routine.
+ */
+void /* PRIVATE */
+png_push_read_sig(png_structrp png_ptr, png_inforp info_ptr)
+{
+ png_size_t num_checked = png_ptr->sig_bytes, /* SAFE, does not exceed 8 */
+ num_to_check = 8 - num_checked;
+
+ if (png_ptr->buffer_size < num_to_check)
+ {
+ num_to_check = png_ptr->buffer_size;
+ }
+
+ png_push_fill_buffer(png_ptr, &(info_ptr->signature[num_checked]),
+ num_to_check);
+ png_ptr->sig_bytes = (png_byte)(png_ptr->sig_bytes + num_to_check);
+
+ if (png_sig_cmp(info_ptr->signature, num_checked, num_to_check))
+ {
+ if (num_checked < 4 &&
+ png_sig_cmp(info_ptr->signature, num_checked, num_to_check - 4))
+ png_error(png_ptr, "Not a PNG file");
+
+ else
+ png_error(png_ptr, "PNG file corrupted by ASCII conversion");
+ }
+ else
+ {
+ if (png_ptr->sig_bytes >= 8)
+ {
+ png_ptr->process_mode = PNG_READ_CHUNK_MODE;
+ }
+ }
+}
+
+void /* PRIVATE */
+png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
+{
+ png_uint_32 chunk_name;
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+ int keep; /* unknown handling method */
+#endif
+
+ /* First we make sure we have enough data for the 4-byte chunk name
+ * and the 4-byte chunk length before proceeding with decoding the
+ * chunk data. To fully decode each of these chunks, we also make
+ * sure we have enough data in the buffer for the 4-byte CRC at the
+ * end of every chunk (except IDAT, which is handled separately).
+ */
+ if ((png_ptr->mode & PNG_HAVE_CHUNK_HEADER) == 0)
+ {
+ png_byte chunk_length[4];
+ png_byte chunk_tag[4];
+
+ PNG_PUSH_SAVE_BUFFER_IF_LT(8)
+ png_push_fill_buffer(png_ptr, chunk_length, 4);
+ png_ptr->push_length = png_get_uint_31(png_ptr, chunk_length);
+ png_reset_crc(png_ptr);
+ png_crc_read(png_ptr, chunk_tag, 4);
+ png_ptr->chunk_name = PNG_CHUNK_FROM_STRING(chunk_tag);
+ png_check_chunk_name(png_ptr, png_ptr->chunk_name);
+ png_ptr->mode |= PNG_HAVE_CHUNK_HEADER;
+ }
+
+ chunk_name = png_ptr->chunk_name;
+
+ if (chunk_name == png_IDAT)
+ {
+ if ((png_ptr->mode & PNG_AFTER_IDAT) != 0)
+ png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT;
+
+ /* If we reach an IDAT chunk, this means we have read all of the
+ * header chunks, and we can start reading the image (or if this
+ * is called after the image has been read - we have an error).
+ */
+ if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
+ png_error(png_ptr, "Missing IHDR before IDAT");
+
+ else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
+ (png_ptr->mode & PNG_HAVE_PLTE) == 0)
+ png_error(png_ptr, "Missing PLTE before IDAT");
+
+ png_ptr->mode |= PNG_HAVE_IDAT;
+ png_ptr->process_mode = PNG_READ_IDAT_MODE;
+
+ if ((png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT) == 0)
+ if (png_ptr->push_length == 0)
+ return;
+
+ if ((png_ptr->mode & PNG_AFTER_IDAT) != 0)
+ png_benign_error(png_ptr, "Too many IDATs found");
+ }
+
+ if (chunk_name == png_IHDR)
+ {
+ if (png_ptr->push_length != 13)
+ png_error(png_ptr, "Invalid IHDR length");
+
+ PNG_PUSH_SAVE_BUFFER_IF_FULL
+ png_handle_IHDR(png_ptr, info_ptr, png_ptr->push_length);
+ }
+
+ else if (chunk_name == png_IEND)
+ {
+ PNG_PUSH_SAVE_BUFFER_IF_FULL
+ png_handle_IEND(png_ptr, info_ptr, png_ptr->push_length);
+
+ png_ptr->process_mode = PNG_READ_DONE_MODE;
+ png_push_have_end(png_ptr, info_ptr);
+ }
+
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+ else if ((keep = png_chunk_unknown_handling(png_ptr, chunk_name)) != 0)
+ {
+ PNG_PUSH_SAVE_BUFFER_IF_FULL
+ png_handle_unknown(png_ptr, info_ptr, png_ptr->push_length, keep);
+
+ if (chunk_name == png_PLTE)
+ png_ptr->mode |= PNG_HAVE_PLTE;
+ }
+#endif
+
+ else if (chunk_name == png_PLTE)
+ {
+ PNG_PUSH_SAVE_BUFFER_IF_FULL
+ png_handle_PLTE(png_ptr, info_ptr, png_ptr->push_length);
+ }
+
+ else if (chunk_name == png_IDAT)
+ {
+ png_ptr->idat_size = png_ptr->push_length;
+ png_ptr->process_mode = PNG_READ_IDAT_MODE;
+ png_push_have_info(png_ptr, info_ptr);
+ png_ptr->zstream.avail_out =
+ (uInt) PNG_ROWBYTES(png_ptr->pixel_depth,
+ png_ptr->iwidth) + 1;
+ png_ptr->zstream.next_out = png_ptr->row_buf;
+ return;
+ }
+
+#ifdef PNG_READ_gAMA_SUPPORTED
+ else if (png_ptr->chunk_name == png_gAMA)
+ {
+ PNG_PUSH_SAVE_BUFFER_IF_FULL
+ png_handle_gAMA(png_ptr, info_ptr, png_ptr->push_length);
+ }
+
+#endif
+#ifdef PNG_READ_sBIT_SUPPORTED
+ else if (png_ptr->chunk_name == png_sBIT)
+ {
+ PNG_PUSH_SAVE_BUFFER_IF_FULL
+ png_handle_sBIT(png_ptr, info_ptr, png_ptr->push_length);
+ }
+
+#endif
+#ifdef PNG_READ_cHRM_SUPPORTED
+ else if (png_ptr->chunk_name == png_cHRM)
+ {
+ PNG_PUSH_SAVE_BUFFER_IF_FULL
+ png_handle_cHRM(png_ptr, info_ptr, png_ptr->push_length);
+ }
+
+#endif
+#ifdef PNG_READ_sRGB_SUPPORTED
+ else if (chunk_name == png_sRGB)
+ {
+ PNG_PUSH_SAVE_BUFFER_IF_FULL
+ png_handle_sRGB(png_ptr, info_ptr, png_ptr->push_length);
+ }
+
+#endif
+#ifdef PNG_READ_iCCP_SUPPORTED
+ else if (png_ptr->chunk_name == png_iCCP)
+ {
+ PNG_PUSH_SAVE_BUFFER_IF_FULL
+ png_handle_iCCP(png_ptr, info_ptr, png_ptr->push_length);
+ }
+
+#endif
+#ifdef PNG_READ_sPLT_SUPPORTED
+ else if (chunk_name == png_sPLT)
+ {
+ PNG_PUSH_SAVE_BUFFER_IF_FULL
+ png_handle_sPLT(png_ptr, info_ptr, png_ptr->push_length);
+ }
+
+#endif
+#ifdef PNG_READ_tRNS_SUPPORTED
+ else if (chunk_name == png_tRNS)
+ {
+ PNG_PUSH_SAVE_BUFFER_IF_FULL
+ png_handle_tRNS(png_ptr, info_ptr, png_ptr->push_length);
+ }
+
+#endif
+#ifdef PNG_READ_bKGD_SUPPORTED
+ else if (chunk_name == png_bKGD)
+ {
+ PNG_PUSH_SAVE_BUFFER_IF_FULL
+ png_handle_bKGD(png_ptr, info_ptr, png_ptr->push_length);
+ }
+
+#endif
+#ifdef PNG_READ_hIST_SUPPORTED
+ else if (chunk_name == png_hIST)
+ {
+ PNG_PUSH_SAVE_BUFFER_IF_FULL
+ png_handle_hIST(png_ptr, info_ptr, png_ptr->push_length);
+ }
+
+#endif
+#ifdef PNG_READ_pHYs_SUPPORTED
+ else if (chunk_name == png_pHYs)
+ {
+ PNG_PUSH_SAVE_BUFFER_IF_FULL
+ png_handle_pHYs(png_ptr, info_ptr, png_ptr->push_length);
+ }
+
+#endif
+#ifdef PNG_READ_oFFs_SUPPORTED
+ else if (chunk_name == png_oFFs)
+ {
+ PNG_PUSH_SAVE_BUFFER_IF_FULL
+ png_handle_oFFs(png_ptr, info_ptr, png_ptr->push_length);
+ }
+#endif
+
+#ifdef PNG_READ_pCAL_SUPPORTED
+ else if (chunk_name == png_pCAL)
+ {
+ PNG_PUSH_SAVE_BUFFER_IF_FULL
+ png_handle_pCAL(png_ptr, info_ptr, png_ptr->push_length);
+ }
+
+#endif
+#ifdef PNG_READ_sCAL_SUPPORTED
+ else if (chunk_name == png_sCAL)
+ {
+ PNG_PUSH_SAVE_BUFFER_IF_FULL
+ png_handle_sCAL(png_ptr, info_ptr, png_ptr->push_length);
+ }
+
+#endif
+#ifdef PNG_READ_tIME_SUPPORTED
+ else if (chunk_name == png_tIME)
+ {
+ PNG_PUSH_SAVE_BUFFER_IF_FULL
+ png_handle_tIME(png_ptr, info_ptr, png_ptr->push_length);
+ }
+
+#endif
+#ifdef PNG_READ_tEXt_SUPPORTED
+ else if (chunk_name == png_tEXt)
+ {
+ PNG_PUSH_SAVE_BUFFER_IF_FULL
+ png_handle_tEXt(png_ptr, info_ptr, png_ptr->push_length);
+ }
+
+#endif
+#ifdef PNG_READ_zTXt_SUPPORTED
+ else if (chunk_name == png_zTXt)
+ {
+ PNG_PUSH_SAVE_BUFFER_IF_FULL
+ png_handle_zTXt(png_ptr, info_ptr, png_ptr->push_length);
+ }
+
+#endif
+#ifdef PNG_READ_iTXt_SUPPORTED
+ else if (chunk_name == png_iTXt)
+ {
+ PNG_PUSH_SAVE_BUFFER_IF_FULL
+ png_handle_iTXt(png_ptr, info_ptr, png_ptr->push_length);
+ }
+#endif
+
+ else
+ {
+ PNG_PUSH_SAVE_BUFFER_IF_FULL
+ png_handle_unknown(png_ptr, info_ptr, png_ptr->push_length,
+ PNG_HANDLE_CHUNK_AS_DEFAULT);
+ }
+
+ png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
+}
+
+void PNGCBAPI
+png_push_fill_buffer(png_structp png_ptr, png_bytep buffer, png_size_t length)
+{
+ png_bytep ptr;
+
+ if (png_ptr == NULL)
+ return;
+
+ ptr = buffer;
+ if (png_ptr->save_buffer_size != 0)
+ {
+ png_size_t save_size;
+
+ if (length < png_ptr->save_buffer_size)
+ save_size = length;
+
+ else
+ save_size = png_ptr->save_buffer_size;
+
+ memcpy(ptr, png_ptr->save_buffer_ptr, save_size);
+ length -= save_size;
+ ptr += save_size;
+ png_ptr->buffer_size -= save_size;
+ png_ptr->save_buffer_size -= save_size;
+ png_ptr->save_buffer_ptr += save_size;
+ }
+ if (length != 0 && png_ptr->current_buffer_size != 0)
+ {
+ png_size_t save_size;
+
+ if (length < png_ptr->current_buffer_size)
+ save_size = length;
+
+ else
+ save_size = png_ptr->current_buffer_size;
+
+ memcpy(ptr, png_ptr->current_buffer_ptr, save_size);
+ png_ptr->buffer_size -= save_size;
+ png_ptr->current_buffer_size -= save_size;
+ png_ptr->current_buffer_ptr += save_size;
+ }
+}
+
+void /* PRIVATE */
+png_push_save_buffer(png_structrp png_ptr)
+{
+ if (png_ptr->save_buffer_size != 0)
+ {
+ if (png_ptr->save_buffer_ptr != png_ptr->save_buffer)
+ {
+ png_size_t i, istop;
+ png_bytep sp;
+ png_bytep dp;
+
+ istop = png_ptr->save_buffer_size;
+ for (i = 0, sp = png_ptr->save_buffer_ptr, dp = png_ptr->save_buffer;
+ i < istop; i++, sp++, dp++)
+ {
+ *dp = *sp;
+ }
+ }
+ }
+ if (png_ptr->save_buffer_size + png_ptr->current_buffer_size >
+ png_ptr->save_buffer_max)
+ {
+ png_size_t new_max;
+ png_bytep old_buffer;
+
+ if (png_ptr->save_buffer_size > PNG_SIZE_MAX -
+ (png_ptr->current_buffer_size + 256))
+ {
+ png_error(png_ptr, "Potential overflow of save_buffer");
+ }
+
+ new_max = png_ptr->save_buffer_size + png_ptr->current_buffer_size + 256;
+ old_buffer = png_ptr->save_buffer;
+ png_ptr->save_buffer = (png_bytep)png_malloc_warn(png_ptr,
+ (png_size_t)new_max);
+
+ if (png_ptr->save_buffer == NULL)
+ {
+ png_free(png_ptr, old_buffer);
+ png_error(png_ptr, "Insufficient memory for save_buffer");
+ }
+
+ memcpy(png_ptr->save_buffer, old_buffer, png_ptr->save_buffer_size);
+ png_free(png_ptr, old_buffer);
+ png_ptr->save_buffer_max = new_max;
+ }
+ if (png_ptr->current_buffer_size)
+ {
+ memcpy(png_ptr->save_buffer + png_ptr->save_buffer_size,
+ png_ptr->current_buffer_ptr, png_ptr->current_buffer_size);
+ png_ptr->save_buffer_size += png_ptr->current_buffer_size;
+ png_ptr->current_buffer_size = 0;
+ }
+ png_ptr->save_buffer_ptr = png_ptr->save_buffer;
+ png_ptr->buffer_size = 0;
+}
+
+void /* PRIVATE */
+png_push_restore_buffer(png_structrp png_ptr, png_bytep buffer,
+ png_size_t buffer_length)
+{
+ png_ptr->current_buffer = buffer;
+ png_ptr->current_buffer_size = buffer_length;
+ png_ptr->buffer_size = buffer_length + png_ptr->save_buffer_size;
+ png_ptr->current_buffer_ptr = png_ptr->current_buffer;
+}
+
+void /* PRIVATE */
+png_push_read_IDAT(png_structrp png_ptr)
+{
+ if ((png_ptr->mode & PNG_HAVE_CHUNK_HEADER) == 0)
+ {
+ png_byte chunk_length[4];
+ png_byte chunk_tag[4];
+
+ /* TODO: this code can be commoned up with the same code in push_read */
+ PNG_PUSH_SAVE_BUFFER_IF_LT(8)
+ png_push_fill_buffer(png_ptr, chunk_length, 4);
+ png_ptr->push_length = png_get_uint_31(png_ptr, chunk_length);
+ png_reset_crc(png_ptr);
+ png_crc_read(png_ptr, chunk_tag, 4);
+ png_ptr->chunk_name = PNG_CHUNK_FROM_STRING(chunk_tag);
+ png_ptr->mode |= PNG_HAVE_CHUNK_HEADER;
+
+ if (png_ptr->chunk_name != png_IDAT)
+ {
+ png_ptr->process_mode = PNG_READ_CHUNK_MODE;
+
+ if ((png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED) == 0)
+ png_error(png_ptr, "Not enough compressed data");
+
+ return;
+ }
+
+ png_ptr->idat_size = png_ptr->push_length;
+ }
+
+ if (png_ptr->idat_size != 0 && png_ptr->save_buffer_size != 0)
+ {
+ png_size_t save_size = png_ptr->save_buffer_size;
+ png_uint_32 idat_size = png_ptr->idat_size;
+
+ /* We want the smaller of 'idat_size' and 'current_buffer_size', but they
+ * are of different types and we don't know which variable has the fewest
+ * bits. Carefully select the smaller and cast it to the type of the
+ * larger - this cannot overflow. Do not cast in the following test - it
+ * will break on either 16-bit or 64-bit platforms.
+ */
+ if (idat_size < save_size)
+ save_size = (png_size_t)idat_size;
+
+ else
+ idat_size = (png_uint_32)save_size;
+
+ png_calculate_crc(png_ptr, png_ptr->save_buffer_ptr, save_size);
+
+ png_process_IDAT_data(png_ptr, png_ptr->save_buffer_ptr, save_size);
+
+ png_ptr->idat_size -= idat_size;
+ png_ptr->buffer_size -= save_size;
+ png_ptr->save_buffer_size -= save_size;
+ png_ptr->save_buffer_ptr += save_size;
+ }
+
+ if (png_ptr->idat_size != 0 && png_ptr->current_buffer_size != 0)
+ {
+ png_size_t save_size = png_ptr->current_buffer_size;
+ png_uint_32 idat_size = png_ptr->idat_size;
+
+ /* We want the smaller of 'idat_size' and 'current_buffer_size', but they
+ * are of different types and we don't know which variable has the fewest
+ * bits. Carefully select the smaller and cast it to the type of the
+ * larger - this cannot overflow.
+ */
+ if (idat_size < save_size)
+ save_size = (png_size_t)idat_size;
+
+ else
+ idat_size = (png_uint_32)save_size;
+
+ png_calculate_crc(png_ptr, png_ptr->current_buffer_ptr, save_size);
+
+ png_process_IDAT_data(png_ptr, png_ptr->current_buffer_ptr, save_size);
+
+ png_ptr->idat_size -= idat_size;
+ png_ptr->buffer_size -= save_size;
+ png_ptr->current_buffer_size -= save_size;
+ png_ptr->current_buffer_ptr += save_size;
+ }
+
+ if (png_ptr->idat_size == 0)
+ {
+ PNG_PUSH_SAVE_BUFFER_IF_LT(4)
+ png_crc_finish(png_ptr, 0);
+ png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
+ png_ptr->mode |= PNG_AFTER_IDAT;
+ png_ptr->zowner = 0;
+ }
+}
+
+void /* PRIVATE */
+png_process_IDAT_data(png_structrp png_ptr, png_bytep buffer,
+ png_size_t buffer_length)
+{
+ /* The caller checks for a non-zero buffer length. */
+ if (!(buffer_length > 0) || buffer == NULL)
+ png_error(png_ptr, "No IDAT data (internal error)");
+
+ /* This routine must process all the data it has been given
+ * before returning, calling the row callback as required to
+ * handle the uncompressed results.
+ */
+ png_ptr->zstream.next_in = buffer;
+ /* TODO: WARNING: TRUNCATION ERROR: DANGER WILL ROBINSON: */
+ png_ptr->zstream.avail_in = (uInt)buffer_length;
+
+ /* Keep going until the decompressed data is all processed
+ * or the stream marked as finished.
+ */
+ while (png_ptr->zstream.avail_in > 0 &&
+ (png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED) == 0)
+ {
+ int ret;
+
+ /* We have data for zlib, but we must check that zlib
+ * has someplace to put the results. It doesn't matter
+ * if we don't expect any results -- it may be the input
+ * data is just the LZ end code.
+ */
+ if (!(png_ptr->zstream.avail_out > 0))
+ {
+ /* TODO: WARNING: TRUNCATION ERROR: DANGER WILL ROBINSON: */
+ png_ptr->zstream.avail_out = (uInt)(PNG_ROWBYTES(png_ptr->pixel_depth,
+ png_ptr->iwidth) + 1);
+
+ png_ptr->zstream.next_out = png_ptr->row_buf;
+ }
+
+ /* Using Z_SYNC_FLUSH here means that an unterminated
+ * LZ stream (a stream with a missing end code) can still
+ * be handled, otherwise (Z_NO_FLUSH) a future zlib
+ * implementation might defer output and therefore
+ * change the current behavior (see comments in inflate.c
+ * for why this doesn't happen at present with zlib 1.2.5).
+ */
+ ret = PNG_INFLATE(png_ptr, Z_SYNC_FLUSH);
+
+ /* Check for any failure before proceeding. */
+ if (ret != Z_OK && ret != Z_STREAM_END)
+ {
+ /* Terminate the decompression. */
+ png_ptr->flags |= PNG_FLAG_ZSTREAM_ENDED;
+ png_ptr->zowner = 0;
+
+ /* This may be a truncated stream (missing or
+ * damaged end code). Treat that as a warning.
+ */
+ if (png_ptr->row_number >= png_ptr->num_rows ||
+ png_ptr->pass > 6)
+ png_warning(png_ptr, "Truncated compressed data in IDAT");
+
+ else
+ png_error(png_ptr, "Decompression error in IDAT");
+
+ /* Skip the check on unprocessed input */
+ return;
+ }
+
+ /* Did inflate output any data? */
+ if (png_ptr->zstream.next_out != png_ptr->row_buf)
+ {
+ /* Is this unexpected data after the last row?
+ * If it is, artificially terminate the LZ output
+ * here.
+ */
+ if (png_ptr->row_number >= png_ptr->num_rows ||
+ png_ptr->pass > 6)
+ {
+ /* Extra data. */
+ png_warning(png_ptr, "Extra compressed data in IDAT");
+ png_ptr->flags |= PNG_FLAG_ZSTREAM_ENDED;
+ png_ptr->zowner = 0;
+
+ /* Do no more processing; skip the unprocessed
+ * input check below.
+ */
+ return;
+ }
+
+ /* Do we have a complete row? */
+ if (png_ptr->zstream.avail_out == 0)
+ png_push_process_row(png_ptr);
+ }
+
+ /* And check for the end of the stream. */
+ if (ret == Z_STREAM_END)
+ png_ptr->flags |= PNG_FLAG_ZSTREAM_ENDED;
+ }
+
+ /* All the data should have been processed, if anything
+ * is left at this point we have bytes of IDAT data
+ * after the zlib end code.
+ */
+ if (png_ptr->zstream.avail_in > 0)
+ png_warning(png_ptr, "Extra compression data in IDAT");
+}
+
+void /* PRIVATE */
+png_push_process_row(png_structrp png_ptr)
+{
+ /* 1.5.6: row_info moved out of png_struct to a local here. */
+ png_row_info row_info;
+
+ row_info.width = png_ptr->iwidth; /* NOTE: width of current interlaced row */
+ row_info.color_type = png_ptr->color_type;
+ row_info.bit_depth = png_ptr->bit_depth;
+ row_info.channels = png_ptr->channels;
+ row_info.pixel_depth = png_ptr->pixel_depth;
+ row_info.rowbytes = PNG_ROWBYTES(row_info.pixel_depth, row_info.width);
+
+ if (png_ptr->row_buf[0] > PNG_FILTER_VALUE_NONE)
+ {
+ if (png_ptr->row_buf[0] < PNG_FILTER_VALUE_LAST)
+ png_read_filter_row(png_ptr, &row_info, png_ptr->row_buf + 1,
+ png_ptr->prev_row + 1, png_ptr->row_buf[0]);
+ else
+ png_error(png_ptr, "bad adaptive filter value");
+ }
+
+ /* libpng 1.5.6: the following line was copying png_ptr->rowbytes before
+ * 1.5.6, while the buffer really is this big in current versions of libpng
+ * it may not be in the future, so this was changed just to copy the
+ * interlaced row count:
+ */
+ memcpy(png_ptr->prev_row, png_ptr->row_buf, row_info.rowbytes + 1);
+
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
+ if (png_ptr->transformations != 0)
+ png_do_read_transformations(png_ptr, &row_info);
+#endif
+
+ /* The transformed pixel depth should match the depth now in row_info. */
+ if (png_ptr->transformed_pixel_depth == 0)
+ {
+ png_ptr->transformed_pixel_depth = row_info.pixel_depth;
+ if (row_info.pixel_depth > png_ptr->maximum_pixel_depth)
+ png_error(png_ptr, "progressive row overflow");
+ }
+
+ else if (png_ptr->transformed_pixel_depth != row_info.pixel_depth)
+ png_error(png_ptr, "internal progressive row size calculation error");
+
+
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+ /* Expand interlaced rows to full size */
+ if (png_ptr->interlaced != 0 &&
+ (png_ptr->transformations & PNG_INTERLACE) != 0)
+ {
+ if (png_ptr->pass < 6)
+ png_do_read_interlace(&row_info, png_ptr->row_buf + 1, png_ptr->pass,
+ png_ptr->transformations);
+
+ switch (png_ptr->pass)
+ {
+ case 0:
+ {
+ int i;
+ for (i = 0; i < 8 && png_ptr->pass == 0; i++)
+ {
+ png_push_have_row(png_ptr, png_ptr->row_buf + 1);
+ png_read_push_finish_row(png_ptr); /* Updates png_ptr->pass */
+ }
+
+ if (png_ptr->pass == 2) /* Pass 1 might be empty */
+ {
+ for (i = 0; i < 4 && png_ptr->pass == 2; i++)
+ {
+ png_push_have_row(png_ptr, NULL);
+ png_read_push_finish_row(png_ptr);
+ }
+ }
+
+ if (png_ptr->pass == 4 && png_ptr->height <= 4)
+ {
+ for (i = 0; i < 2 && png_ptr->pass == 4; i++)
+ {
+ png_push_have_row(png_ptr, NULL);
+ png_read_push_finish_row(png_ptr);
+ }
+ }
+
+ if (png_ptr->pass == 6 && png_ptr->height <= 4)
+ {
+ png_push_have_row(png_ptr, NULL);
+ png_read_push_finish_row(png_ptr);
+ }
+
+ break;
+ }
+
+ case 1:
+ {
+ int i;
+ for (i = 0; i < 8 && png_ptr->pass == 1; i++)
+ {
+ png_push_have_row(png_ptr, png_ptr->row_buf + 1);
+ png_read_push_finish_row(png_ptr);
+ }
+
+ if (png_ptr->pass == 2) /* Skip top 4 generated rows */
+ {
+ for (i = 0; i < 4 && png_ptr->pass == 2; i++)
+ {
+ png_push_have_row(png_ptr, NULL);
+ png_read_push_finish_row(png_ptr);
+ }
+ }
+
+ break;
+ }
+
+ case 2:
+ {
+ int i;
+
+ for (i = 0; i < 4 && png_ptr->pass == 2; i++)
+ {
+ png_push_have_row(png_ptr, png_ptr->row_buf + 1);
+ png_read_push_finish_row(png_ptr);
+ }
+
+ for (i = 0; i < 4 && png_ptr->pass == 2; i++)
+ {
+ png_push_have_row(png_ptr, NULL);
+ png_read_push_finish_row(png_ptr);
+ }
+
+ if (png_ptr->pass == 4) /* Pass 3 might be empty */
+ {
+ for (i = 0; i < 2 && png_ptr->pass == 4; i++)
+ {
+ png_push_have_row(png_ptr, NULL);
+ png_read_push_finish_row(png_ptr);
+ }
+ }
+
+ break;
+ }
+
+ case 3:
+ {
+ int i;
+
+ for (i = 0; i < 4 && png_ptr->pass == 3; i++)
+ {
+ png_push_have_row(png_ptr, png_ptr->row_buf + 1);
+ png_read_push_finish_row(png_ptr);
+ }
+
+ if (png_ptr->pass == 4) /* Skip top two generated rows */
+ {
+ for (i = 0; i < 2 && png_ptr->pass == 4; i++)
+ {
+ png_push_have_row(png_ptr, NULL);
+ png_read_push_finish_row(png_ptr);
+ }
+ }
+
+ break;
+ }
+
+ case 4:
+ {
+ int i;
+
+ for (i = 0; i < 2 && png_ptr->pass == 4; i++)
+ {
+ png_push_have_row(png_ptr, png_ptr->row_buf + 1);
+ png_read_push_finish_row(png_ptr);
+ }
+
+ for (i = 0; i < 2 && png_ptr->pass == 4; i++)
+ {
+ png_push_have_row(png_ptr, NULL);
+ png_read_push_finish_row(png_ptr);
+ }
+
+ if (png_ptr->pass == 6) /* Pass 5 might be empty */
+ {
+ png_push_have_row(png_ptr, NULL);
+ png_read_push_finish_row(png_ptr);
+ }
+
+ break;
+ }
+
+ case 5:
+ {
+ int i;
+
+ for (i = 0; i < 2 && png_ptr->pass == 5; i++)
+ {
+ png_push_have_row(png_ptr, png_ptr->row_buf + 1);
+ png_read_push_finish_row(png_ptr);
+ }
+
+ if (png_ptr->pass == 6) /* Skip top generated row */
+ {
+ png_push_have_row(png_ptr, NULL);
+ png_read_push_finish_row(png_ptr);
+ }
+
+ break;
+ }
+
+ default:
+ case 6:
+ {
+ png_push_have_row(png_ptr, png_ptr->row_buf + 1);
+ png_read_push_finish_row(png_ptr);
+
+ if (png_ptr->pass != 6)
+ break;
+
+ png_push_have_row(png_ptr, NULL);
+ png_read_push_finish_row(png_ptr);
+ }
+ }
+ }
+ else
+#endif
+ {
+ png_push_have_row(png_ptr, png_ptr->row_buf + 1);
+ png_read_push_finish_row(png_ptr);
+ }
+}
+
+void /* PRIVATE */
+png_read_push_finish_row(png_structrp png_ptr)
+{
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+ /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
+
+ /* Start of interlace block */
+ static PNG_CONST png_byte png_pass_start[] = {0, 4, 0, 2, 0, 1, 0};
+
+ /* Offset to next interlace block */
+ static PNG_CONST png_byte png_pass_inc[] = {8, 8, 4, 4, 2, 2, 1};
+
+ /* Start of interlace block in the y direction */
+ static PNG_CONST png_byte png_pass_ystart[] = {0, 0, 4, 0, 2, 0, 1};
+
+ /* Offset to next interlace block in the y direction */
+ static PNG_CONST png_byte png_pass_yinc[] = {8, 8, 8, 4, 4, 2, 2};
+
+ /* Height of interlace block. This is not currently used - if you need
+ * it, uncomment it here and in png.h
+ static PNG_CONST png_byte png_pass_height[] = {8, 8, 4, 4, 2, 2, 1};
+ */
+#endif
+
+ png_ptr->row_number++;
+ if (png_ptr->row_number < png_ptr->num_rows)
+ return;
+
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+ if (png_ptr->interlaced != 0)
+ {
+ png_ptr->row_number = 0;
+ memset(png_ptr->prev_row, 0, png_ptr->rowbytes + 1);
+
+ do
+ {
+ png_ptr->pass++;
+ if ((png_ptr->pass == 1 && png_ptr->width < 5) ||
+ (png_ptr->pass == 3 && png_ptr->width < 3) ||
+ (png_ptr->pass == 5 && png_ptr->width < 2))
+ png_ptr->pass++;
+
+ if (png_ptr->pass > 7)
+ png_ptr->pass--;
+
+ if (png_ptr->pass >= 7)
+ break;
+
+ png_ptr->iwidth = (png_ptr->width +
+ png_pass_inc[png_ptr->pass] - 1 -
+ png_pass_start[png_ptr->pass]) /
+ png_pass_inc[png_ptr->pass];
+
+ if ((png_ptr->transformations & PNG_INTERLACE) != 0)
+ break;
+
+ png_ptr->num_rows = (png_ptr->height +
+ png_pass_yinc[png_ptr->pass] - 1 -
+ png_pass_ystart[png_ptr->pass]) /
+ png_pass_yinc[png_ptr->pass];
+
+ } while (png_ptr->iwidth == 0 || png_ptr->num_rows == 0);
+ }
+#endif /* READ_INTERLACING */
+}
+
+void /* PRIVATE */
+png_push_have_info(png_structrp png_ptr, png_inforp info_ptr)
+{
+ if (png_ptr->info_fn != NULL)
+ (*(png_ptr->info_fn))(png_ptr, info_ptr);
+}
+
+void /* PRIVATE */
+png_push_have_end(png_structrp png_ptr, png_inforp info_ptr)
+{
+ if (png_ptr->end_fn != NULL)
+ (*(png_ptr->end_fn))(png_ptr, info_ptr);
+}
+
+void /* PRIVATE */
+png_push_have_row(png_structrp png_ptr, png_bytep row)
+{
+ if (png_ptr->row_fn != NULL)
+ (*(png_ptr->row_fn))(png_ptr, row, png_ptr->row_number,
+ (int)png_ptr->pass);
+}
+
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+void PNGAPI
+png_progressive_combine_row(png_const_structrp png_ptr, png_bytep old_row,
+ png_const_bytep new_row)
+{
+ if (png_ptr == NULL)
+ return;
+
+ /* new_row is a flag here - if it is NULL then the app callback was called
+ * from an empty row (see the calls to png_struct::row_fn below), otherwise
+ * it must be png_ptr->row_buf+1
+ */
+ if (new_row != NULL)
+ png_combine_row(png_ptr, old_row, 1/*blocky display*/);
+}
+#endif /* READ_INTERLACING */
+
+void PNGAPI
+png_set_progressive_read_fn(png_structrp png_ptr, png_voidp progressive_ptr,
+ png_progressive_info_ptr info_fn, png_progressive_row_ptr row_fn,
+ png_progressive_end_ptr end_fn)
+{
+ if (png_ptr == NULL)
+ return;
+
+ png_ptr->info_fn = info_fn;
+ png_ptr->row_fn = row_fn;
+ png_ptr->end_fn = end_fn;
+
+ png_set_read_fn(png_ptr, progressive_ptr, png_push_fill_buffer);
+}
+
+png_voidp PNGAPI
+png_get_progressive_ptr(png_const_structrp png_ptr)
+{
+ if (png_ptr == NULL)
+ return (NULL);
+
+ return png_ptr->io_ptr;
+}
+#endif /* PROGRESSIVE_READ */
diff --git a/third_party/lpng_v163/pngpriv.h b/third_party/libpng/pngpriv.h
similarity index 90%
rename from third_party/lpng_v163/pngpriv.h
rename to third_party/libpng/pngpriv.h
index 4ef3b18..58d3aa8 100644
--- a/third_party/lpng_v163/pngpriv.h
+++ b/third_party/libpng/pngpriv.h
@@ -1,2010 +1,1929 @@
-
-/* pngpriv.h - private declarations for use inside libpng
- *
- * For conditions of distribution and use, see copyright notice in png.h
- * Copyright (c) 1998-2013 Glenn Randers-Pehrson
- * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
- * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
- *
- * Last changed in libpng 1.6.3 [July 18, 2013]
- *
- * This code is released under the libpng license.
- * For conditions of distribution and use, see the disclaimer
- * and license in png.h
- */
-
-/* The symbols declared in this file (including the functions declared
- * as extern) are PRIVATE. They are not part of the libpng public
- * interface, and are not recommended for use by regular applications.
- * Some of them may become public in the future; others may stay private,
- * change in an incompatible way, or even disappear.
- * Although the libpng users are not forbidden to include this header,
- * they should be well aware of the issues that may arise from doing so.
- */
-
-#ifndef PNGPRIV_H
-#define PNGPRIV_H
-
-/* Feature Test Macros. The following are defined here to ensure that correctly
- * implemented libraries reveal the APIs libpng needs to build and hide those
- * that are not needed and potentially damaging to the compilation.
- *
- * Feature Test Macros must be defined before any system header is included (see
- * POSIX 1003.1 2.8.2 "POSIX Symbols."
- *
- * These macros only have an effect if the operating system supports either
- * POSIX 1003.1 or C99, or both. On other operating systems (particularly
- * Windows/Visual Studio) there is no effect; the OS specific tests below are
- * still required (as of 2011-05-02.)
- */
-#define _POSIX_SOURCE 1 /* Just the POSIX 1003.1 and C89 APIs */
-
-#ifndef PNG_VERSION_INFO_ONLY
-/* Standard library headers not required by png.h: */
-# include <stdlib.h>
-# include <string.h>
-#endif
-
-#define PNGLIB_BUILD /*libpng is being built, not used*/
-
-/* If HAVE_CONFIG_H is defined during the build then the build system must
- * provide an appropriate "config.h" file on the include path. The header file
- * must provide definitions as required below (search for "HAVE_CONFIG_H");
- * see configure.ac for more details of the requirements. The macro
- * "PNG_NO_CONFIG_H" is provided for maintainers to test for dependencies on
- * 'configure'; define this macro to prevent the configure build including the
- * configure generated config.h. Libpng is expected to compile without *any*
- * special build system support on a reasonably ANSI-C compliant system.
- */
-#if defined(HAVE_CONFIG_H) && !defined(PNG_NO_CONFIG_H)
-# include <config.h>
-
- /* Pick up the definition of 'restrict' from config.h if it was read: */
-# define PNG_RESTRICT restrict
-#endif
-
-/* To support symbol prefixing it is necessary to know *before* including png.h
- * whether the fixed point (and maybe other) APIs are exported, because if they
- * are not internal definitions may be required. This is handled below just
- * before png.h is included, but load the configuration now if it is available.
- */
-#ifndef PNGLCONF_H
-# include "pnglibconf.h"
-#endif
-
-/* Local renames may change non-exported API functions from png.h */
-#if defined(PNG_PREFIX) && !defined(PNGPREFIX_H)
-# include "pngprefix.h"
-#endif
-
-#ifdef PNG_USER_CONFIG
-# include "pngusr.h"
- /* These should have been defined in pngusr.h */
-# ifndef PNG_USER_PRIVATEBUILD
-# define PNG_USER_PRIVATEBUILD "Custom libpng build"
-# endif
-# ifndef PNG_USER_DLLFNAME_POSTFIX
-# define PNG_USER_DLLFNAME_POSTFIX "Cb"
-# endif
-#endif
-
-/* Compile time options.
- * =====================
- * In a multi-arch build the compiler may compile the code several times for the
- * same object module, producing different binaries for different architectures.
- * When this happens configure-time setting of the target host options cannot be
- * done and this interferes with the handling of the ARM NEON optimizations, and
- * possibly other similar optimizations. Put additional tests here; in general
- * this is needed when the same option can be changed at both compile time and
- * run time depending on the target OS (i.e. iOS vs Android.)
- *
- * NOTE: symbol prefixing does not pass $(CFLAGS) to the preprocessor, because
- * this is not possible with certain compilers (Oracle SUN OS CC), as a result
- * it is necessary to ensure that all extern functions that *might* be used
- * regardless of $(CFLAGS) get declared in this file. The test on __ARM_NEON__
- * below is one example of this behavior because it is controlled by the
- * presence or not of -mfpu=neon on the GCC command line, it is possible to do
- * this in $(CC), e.g. "CC=gcc -mfpu=neon", but people who build libpng rarely
- * do this.
- */
-#ifndef PNG_ARM_NEON_OPT
- /* ARM NEON optimizations are being controlled by the compiler settings,
- * typically the target FPU. If the FPU has been set to NEON (-mfpu=neon
- * with GCC) then the compiler will define __ARM_NEON__ and we can rely
- * unconditionally on NEON instructions not crashing, otherwise we must
- * disable use of NEON instructions:
- */
-# ifdef __ARM_NEON__
-# define PNG_ARM_NEON_OPT 2
-# else
-# define PNG_ARM_NEON_OPT 0
-# endif
-#endif
-
-#if PNG_ARM_NEON_OPT > 0
- /* NEON optimizations are to be at least considered by libpng, so enable the
- * callbacks to do this.
- */
-/*
- * Disabled by sbc since this copy of libpng doesn't contains the arm
- * specific code (e.g. arm/arm_init.c)
- */
-/*# define PNG_FILTER_OPTIMIZATIONS png_init_filter_functions_neon*/
-#endif
-
-/* Is this a build of a DLL where compilation of the object modules requires
- * different preprocessor settings to those required for a simple library? If
- * so PNG_BUILD_DLL must be set.
- *
- * If libpng is used inside a DLL but that DLL does not export the libpng APIs
- * PNG_BUILD_DLL must not be set. To avoid the code below kicking in build a
- * static library of libpng then link the DLL against that.
- */
-#ifndef PNG_BUILD_DLL
-# ifdef DLL_EXPORT
- /* This is set by libtool when files are compiled for a DLL; libtool
- * always compiles twice, even on systems where it isn't necessary. Set
- * PNG_BUILD_DLL in case it is necessary:
- */
-# define PNG_BUILD_DLL
-# else
-# ifdef _WINDLL
- /* This is set by the Microsoft Visual Studio IDE in projects that
- * build a DLL. It can't easily be removed from those projects (it
- * isn't visible in the Visual Studio UI) so it is a fairly reliable
- * indication that PNG_IMPEXP needs to be set to the DLL export
- * attributes.
- */
-# define PNG_BUILD_DLL
-# else
-# ifdef __DLL__
- /* This is set by the Borland C system when compiling for a DLL
- * (as above.)
- */
-# define PNG_BUILD_DLL
-# else
- /* Add additional compiler cases here. */
-# endif
-# endif
-# endif
-#endif /* Setting PNG_BUILD_DLL if required */
-
-/* See pngconf.h for more details: the builder of the library may set this on
- * the command line to the right thing for the specific compilation system or it
- * may be automagically set above (at present we know of no system where it does
- * need to be set on the command line.)
- *
- * PNG_IMPEXP must be set here when building the library to prevent pngconf.h
- * setting it to the "import" setting for a DLL build.
- */
-#ifndef PNG_IMPEXP
-# ifdef PNG_BUILD_DLL
-# define PNG_IMPEXP PNG_DLL_EXPORT
-# else
- /* Not building a DLL, or the DLL doesn't require specific export
- * definitions.
- */
-# define PNG_IMPEXP
-# endif
-#endif
-
-/* No warnings for private or deprecated functions in the build: */
-#ifndef PNG_DEPRECATED
-# define PNG_DEPRECATED
-#endif
-#ifndef PNG_PRIVATE
-# define PNG_PRIVATE
-#endif
-
-/* Symbol preprocessing support.
- *
- * To enable listing global, but internal, symbols the following macros should
- * always be used to declare an extern data or function object in this file.
- */
-#ifndef PNG_INTERNAL_DATA
-# define PNG_INTERNAL_DATA(type, name, array) extern type name array
-#endif
-
-#ifndef PNG_INTERNAL_FUNCTION
-# define PNG_INTERNAL_FUNCTION(type, name, args, attributes)\
- extern PNG_FUNCTION(type, name, args, PNG_EMPTY attributes)
-#endif
-
-/* If floating or fixed point APIs are disabled they may still be compiled
- * internally. To handle this make sure they are declared as the appropriate
- * internal extern function (otherwise the symbol prefixing stuff won't work and
- * the functions will be used without definitions.)
- *
- * NOTE: although all the API functions are declared here they are not all
- * actually built! Because the declarations are still made it is necessary to
- * fake out types that they depend on.
- */
-#ifndef PNG_FP_EXPORT
-# ifndef PNG_FLOATING_POINT_SUPPORTED
-# define PNG_FP_EXPORT(ordinal, type, name, args)\
- PNG_INTERNAL_FUNCTION(type, name, args, PNG_EMPTY);
-# ifndef PNG_VERSION_INFO_ONLY
- typedef struct png_incomplete png_double;
- typedef png_double* png_doublep;
- typedef const png_double* png_const_doublep;
- typedef png_double** png_doublepp;
-# endif
-# endif
-#endif
-#ifndef PNG_FIXED_EXPORT
-# ifndef PNG_FIXED_POINT_SUPPORTED
-# define PNG_FIXED_EXPORT(ordinal, type, name, args)\
- PNG_INTERNAL_FUNCTION(type, name, args, PNG_EMPTY);
-# endif
-#endif
-
-#include "png.h"
-
-/* pngconf.h does not set PNG_DLL_EXPORT unless it is required, so: */
-#ifndef PNG_DLL_EXPORT
-# define PNG_DLL_EXPORT
-#endif
-
-/* SECURITY and SAFETY:
- *
- * By default libpng is built without any internal limits on image size,
- * individual heap (png_malloc) allocations or the total amount of memory used.
- * If PNG_SAFE_LIMITS_SUPPORTED is defined, however, the limits below are used
- * (unless individually overridden). These limits are believed to be fairly
- * safe, but builders of secure systems should verify the values against the
- * real system capabilities.
- */
-#ifdef PNG_SAFE_LIMITS_SUPPORTED
- /* 'safe' limits */
-# ifndef PNG_USER_WIDTH_MAX
-# define PNG_USER_WIDTH_MAX 1000000
-# endif
-# ifndef PNG_USER_HEIGHT_MAX
-# define PNG_USER_HEIGHT_MAX 1000000
-# endif
-# ifndef PNG_USER_CHUNK_CACHE_MAX
-# define PNG_USER_CHUNK_CACHE_MAX 128
-# endif
-# ifndef PNG_USER_CHUNK_MALLOC_MAX
-# define PNG_USER_CHUNK_MALLOC_MAX 8000000
-# endif
-#else
- /* values for no limits */
-# ifndef PNG_USER_WIDTH_MAX
-# define PNG_USER_WIDTH_MAX 0x7fffffff
-# endif
-# ifndef PNG_USER_HEIGHT_MAX
-# define PNG_USER_HEIGHT_MAX 0x7fffffff
-# endif
-# ifndef PNG_USER_CHUNK_CACHE_MAX
-# define PNG_USER_CHUNK_CACHE_MAX 0
-# endif
-# ifndef PNG_USER_CHUNK_MALLOC_MAX
-# define PNG_USER_CHUNK_MALLOC_MAX 0
-# endif
-#endif
-
-/* Moved to pngpriv.h at libpng-1.5.0 */
-/* NOTE: some of these may have been used in external applications as
- * these definitions were exposed in pngconf.h prior to 1.5.
- */
-
-/* If you are running on a machine where you cannot allocate more
- * than 64K of memory at once, uncomment this. While libpng will not
- * normally need that much memory in a chunk (unless you load up a very
- * large file), zlib needs to know how big of a chunk it can use, and
- * libpng thus makes sure to check any memory allocation to verify it
- * will fit into memory.
- *
- * zlib provides 'MAXSEG_64K' which, if defined, indicates the
- * same limit and pngconf.h (already included) sets the limit
- * if certain operating systems are detected.
- */
-#if defined(MAXSEG_64K) && !defined(PNG_MAX_MALLOC_64K)
-# define PNG_MAX_MALLOC_64K
-#endif
-
-#ifndef PNG_UNUSED
-/* Unused formal parameter warnings are silenced using the following macro
- * which is expected to have no bad effects on performance (optimizing
- * compilers will probably remove it entirely). Note that if you replace
- * it with something other than whitespace, you must include the terminating
- * semicolon.
- */
-# define PNG_UNUSED(param) (void)param;
-#endif
-
-/* Just a little check that someone hasn't tried to define something
- * contradictory.
- */
-#if (PNG_ZBUF_SIZE > 65536L) && defined(PNG_MAX_MALLOC_64K)
-# undef PNG_ZBUF_SIZE
-# define PNG_ZBUF_SIZE 65536L
-#endif
-
-/* If warnings or errors are turned off the code is disabled or redirected here.
- * From 1.5.4 functions have been added to allow very limited formatting of
- * error and warning messages - this code will also be disabled here.
- */
-#ifdef PNG_WARNINGS_SUPPORTED
-# define PNG_WARNING_PARAMETERS(p) png_warning_parameters p;
-#else
-# define png_warning(s1,s2) ((void)(s1))
-# define png_chunk_warning(s1,s2) ((void)(s1))
-# define png_warning_parameter(p,number,string) ((void)0)
-# define png_warning_parameter_unsigned(p,number,format,value) ((void)0)
-# define png_warning_parameter_signed(p,number,format,value) ((void)0)
-# define png_formatted_warning(pp,p,message) ((void)(pp))
-# define PNG_WARNING_PARAMETERS(p)
-#endif
-#ifndef PNG_ERROR_TEXT_SUPPORTED
-# define png_error(s1,s2) png_err(s1)
-# define png_chunk_error(s1,s2) png_err(s1)
-# define png_fixed_error(s1,s2) png_err(s1)
-#endif
-
-/* C allows up-casts from (void*) to any pointer and (const void*) to any
- * pointer to a const object. C++ regards this as a type error and requires an
- * explicit, static, cast and provides the static_cast<> rune to ensure that
- * const is not cast away.
- */
-#ifdef __cplusplus
-# define png_voidcast(type, value) static_cast<type>(value)
-# define png_constcast(type, value) const_cast<type>(value)
-# define png_aligncast(type, value) \
- static_cast<type>(static_cast<void*>(value))
-# define png_aligncastconst(type, value) \
- static_cast<type>(static_cast<const void*>(value))
-#else
-# define png_voidcast(type, value) (value)
-# define png_constcast(type, value) ((type)(value))
-# define png_aligncast(type, value) ((void*)(value))
-# define png_aligncastconst(type, value) ((const void*)(value))
-#endif /* __cplusplus */
-
-/* Some fixed point APIs are still required even if not exported because
- * they get used by the corresponding floating point APIs. This magic
- * deals with this:
- */
-#ifdef PNG_FIXED_POINT_SUPPORTED
-# define PNGFAPI PNGAPI
-#else
-# define PNGFAPI /* PRIVATE */
-#endif
-
-#ifndef PNG_VERSION_INFO_ONLY
-/* Other defines specific to compilers can go here. Try to keep
- * them inside an appropriate ifdef/endif pair for portability.
- */
-#if defined(PNG_FLOATING_POINT_SUPPORTED) ||\
- defined(PNG_FLOATING_ARITHMETIC_SUPPORTED)
- /* png.c requires the following ANSI-C constants if the conversion of
- * floating point to ASCII is implemented therein:
- *
- * DBL_DIG Maximum number of decimal digits (can be set to any constant)
- * DBL_MIN Smallest normalized fp number (can be set to an arbitrary value)
- * DBL_MAX Maximum floating point number (can be set to an arbitrary value)
- */
-# include <float.h>
-
-# if (defined(__MWERKS__) && defined(macintosh)) || defined(applec) || \
- defined(THINK_C) || defined(__SC__) || defined(TARGET_OS_MAC)
- /* We need to check that <math.h> hasn't already been included earlier
- * as it seems it doesn't agree with <fp.h>, yet we should really use
- * <fp.h> if possible.
- */
-# if !defined(__MATH_H__) && !defined(__MATH_H) && !defined(__cmath__)
-# include <fp.h>
-# endif
-# else
-# include <math.h>
-# endif
-# if defined(_AMIGA) && defined(__SASC) && defined(_M68881)
- /* Amiga SAS/C: We must include builtin FPU functions when compiling using
- * MATH=68881
- */
-# include <m68881.h>
-# endif
-#endif
-
-/* This provides the non-ANSI (far) memory allocation routines. */
-#if defined(__TURBOC__) && defined(__MSDOS__)
-# include <mem.h>
-# include <alloc.h>
-#endif
-
-#if defined(WIN32) || defined(_Windows) || defined(_WINDOWS) || \
- defined(_WIN32) || defined(__WIN32__)
-# include <windows.h> /* defines _WINDOWS_ macro */
-#endif
-#endif /* PNG_VERSION_INFO_ONLY */
-
-/* Moved here around 1.5.0beta36 from pngconf.h */
-/* Users may want to use these so they are not private. Any library
- * functions that are passed far data must be model-independent.
- */
-
-/* Memory model/platform independent fns */
-#ifndef PNG_ABORT
-# ifdef _WINDOWS_
-# define PNG_ABORT() ExitProcess(0)
-# else
-# define PNG_ABORT() abort()
-# endif
-#endif
-
-/* These macros may need to be architecture dependent. */
-#define PNG_ALIGN_NONE 0 /* do not use data alignment */
-#define PNG_ALIGN_ALWAYS 1 /* assume unaligned accesses are OK */
-#ifdef offsetof
-# define PNG_ALIGN_OFFSET 2 /* use offsetof to determine alignment */
-#else
-# define PNG_ALIGN_OFFSET -1 /* prevent the use of this */
-#endif
-#define PNG_ALIGN_SIZE 3 /* use sizeof to determine alignment */
-
-#ifndef PNG_ALIGN_TYPE
- /* Default to using aligned access optimizations and requiring alignment to a
- * multiple of the data type size. Override in a compiler specific fashion
- * if necessary by inserting tests here:
- */
-# define PNG_ALIGN_TYPE PNG_ALIGN_SIZE
-#endif
-
-#if PNG_ALIGN_TYPE == PNG_ALIGN_SIZE
- /* This is used because in some compiler implementations non-aligned
- * structure members are supported, so the offsetof approach below fails.
- * Set PNG_ALIGN_SIZE=0 for compiler combinations where unaligned access
- * is good for performance. Do not do this unless you have tested the result
- * and understand it.
- */
-# define png_alignof(type) (sizeof (type))
-#else
-# if PNG_ALIGN_TYPE == PNG_ALIGN_OFFSET
-# define png_alignof(type) offsetof(struct{char c; type t;}, t)
-# else
-# if PNG_ALIGN_TYPE == PNG_ALIGN_ALWAYS
-# define png_alignof(type) (1)
-# endif
- /* Else leave png_alignof undefined to prevent use thereof */
-# endif
-#endif
-
-/* This implicitly assumes alignment is always to a power of 2. */
-#ifdef png_alignof
-# define png_isaligned(ptr, type)\
- ((((const char*)ptr-(const char*)0) & (png_alignof(type)-1)) == 0)
-#else
-# define png_isaligned(ptr, type) 0
-#endif
-
-/* End of memory model/platform independent support */
-/* End of 1.5.0beta36 move from pngconf.h */
-
-/* CONSTANTS and UTILITY MACROS
- * These are used internally by libpng and not exposed in the API
- */
-
-/* Various modes of operation. Note that after an init, mode is set to
- * zero automatically when the structure is created. Three of these
- * are defined in png.h because they need to be visible to applications
- * that call png_set_unknown_chunk().
- */
-/* #define PNG_HAVE_IHDR 0x01 (defined in png.h) */
-/* #define PNG_HAVE_PLTE 0x02 (defined in png.h) */
-#define PNG_HAVE_IDAT 0x04
-/* #define PNG_AFTER_IDAT 0x08 (defined in png.h) */
-#define PNG_HAVE_IEND 0x10
- /* 0x20 (unused) */
- /* 0x40 (unused) */
- /* 0x80 (unused) */
-#define PNG_HAVE_CHUNK_HEADER 0x100
-#define PNG_WROTE_tIME 0x200
-#define PNG_WROTE_INFO_BEFORE_PLTE 0x400
-#define PNG_BACKGROUND_IS_GRAY 0x800
-#define PNG_HAVE_PNG_SIGNATURE 0x1000
-#define PNG_HAVE_CHUNK_AFTER_IDAT 0x2000 /* Have another chunk after IDAT */
- /* 0x4000 (unused) */
-#define PNG_IS_READ_STRUCT 0x8000 /* Else is a write struct */
-
-/* Flags for the transformations the PNG library does on the image data */
-#define PNG_BGR 0x0001
-#define PNG_INTERLACE 0x0002
-#define PNG_PACK 0x0004
-#define PNG_SHIFT 0x0008
-#define PNG_SWAP_BYTES 0x0010
-#define PNG_INVERT_MONO 0x0020
-#define PNG_QUANTIZE 0x0040
-#define PNG_COMPOSE 0x0080 /* Was PNG_BACKGROUND */
-#define PNG_BACKGROUND_EXPAND 0x0100
-#define PNG_EXPAND_16 0x0200 /* Added to libpng 1.5.2 */
-#define PNG_16_TO_8 0x0400 /* Becomes 'chop' in 1.5.4 */
-#define PNG_RGBA 0x0800
-#define PNG_EXPAND 0x1000
-#define PNG_GAMMA 0x2000
-#define PNG_GRAY_TO_RGB 0x4000
-#define PNG_FILLER 0x8000
-#define PNG_PACKSWAP 0x10000
-#define PNG_SWAP_ALPHA 0x20000
-#define PNG_STRIP_ALPHA 0x40000
-#define PNG_INVERT_ALPHA 0x80000
-#define PNG_USER_TRANSFORM 0x100000
-#define PNG_RGB_TO_GRAY_ERR 0x200000
-#define PNG_RGB_TO_GRAY_WARN 0x400000
-#define PNG_RGB_TO_GRAY 0x600000 /* two bits, RGB_TO_GRAY_ERR|WARN */
-#define PNG_ENCODE_ALPHA 0x800000 /* Added to libpng-1.5.4 */
-#define PNG_ADD_ALPHA 0x1000000 /* Added to libpng-1.2.7 */
-#define PNG_EXPAND_tRNS 0x2000000 /* Added to libpng-1.2.9 */
-#define PNG_SCALE_16_TO_8 0x4000000 /* Added to libpng-1.5.4 */
- /* 0x8000000 unused */
- /* 0x10000000 unused */
- /* 0x20000000 unused */
- /* 0x40000000 unused */
-/* Flags for png_create_struct */
-#define PNG_STRUCT_PNG 0x0001
-#define PNG_STRUCT_INFO 0x0002
-
-/* Scaling factor for filter heuristic weighting calculations */
-#define PNG_WEIGHT_FACTOR (1<<(PNG_WEIGHT_SHIFT))
-#define PNG_COST_FACTOR (1<<(PNG_COST_SHIFT))
-
-/* Flags for the png_ptr->flags rather than declaring a byte for each one */
-#define PNG_FLAG_ZLIB_CUSTOM_STRATEGY 0x0001
-#define PNG_FLAG_ZSTREAM_INITIALIZED 0x0002 /* Added to libpng-1.6.0 */
- /* 0x0004 unused */
-#define PNG_FLAG_ZSTREAM_ENDED 0x0008 /* Added to libpng-1.6.0 */
- /* 0x0010 unused */
- /* 0x0020 unused */
-#define PNG_FLAG_ROW_INIT 0x0040
-#define PNG_FLAG_FILLER_AFTER 0x0080
-#define PNG_FLAG_CRC_ANCILLARY_USE 0x0100
-#define PNG_FLAG_CRC_ANCILLARY_NOWARN 0x0200
-#define PNG_FLAG_CRC_CRITICAL_USE 0x0400
-#define PNG_FLAG_CRC_CRITICAL_IGNORE 0x0800
-#define PNG_FLAG_ASSUME_sRGB 0x1000 /* Added to libpng-1.5.4 */
-#define PNG_FLAG_OPTIMIZE_ALPHA 0x2000 /* Added to libpng-1.5.4 */
-#define PNG_FLAG_DETECT_UNINITIALIZED 0x4000 /* Added to libpng-1.5.4 */
-/* #define PNG_FLAG_KEEP_UNKNOWN_CHUNKS 0x8000 */
-/* #define PNG_FLAG_KEEP_UNSAFE_CHUNKS 0x10000 */
-#define PNG_FLAG_LIBRARY_MISMATCH 0x20000
-#define PNG_FLAG_STRIP_ERROR_NUMBERS 0x40000
-#define PNG_FLAG_STRIP_ERROR_TEXT 0x80000
-#define PNG_FLAG_BENIGN_ERRORS_WARN 0x100000 /* Added to libpng-1.4.0 */
-#define PNG_FLAG_APP_WARNINGS_WARN 0x200000 /* Added to libpng-1.6.0 */
-#define PNG_FLAG_APP_ERRORS_WARN 0x400000 /* Added to libpng-1.6.0 */
- /* 0x800000 unused */
- /* 0x1000000 unused */
- /* 0x2000000 unused */
- /* 0x4000000 unused */
- /* 0x8000000 unused */
- /* 0x10000000 unused */
- /* 0x20000000 unused */
- /* 0x40000000 unused */
-
-#define PNG_FLAG_CRC_ANCILLARY_MASK (PNG_FLAG_CRC_ANCILLARY_USE | \
- PNG_FLAG_CRC_ANCILLARY_NOWARN)
-
-#define PNG_FLAG_CRC_CRITICAL_MASK (PNG_FLAG_CRC_CRITICAL_USE | \
- PNG_FLAG_CRC_CRITICAL_IGNORE)
-
-#define PNG_FLAG_CRC_MASK (PNG_FLAG_CRC_ANCILLARY_MASK | \
- PNG_FLAG_CRC_CRITICAL_MASK)
-
-/* Save typing and make code easier to understand */
-
-#define PNG_COLOR_DIST(c1, c2) (abs((int)((c1).red) - (int)((c2).red)) + \
- abs((int)((c1).green) - (int)((c2).green)) + \
- abs((int)((c1).blue) - (int)((c2).blue)))
-
-/* Added to libpng-1.6.0: scale a 16-bit value in the range 0..65535 to 0..255
- * by dividing by 257 *with rounding*. This macro is exact for the given range.
- * See the discourse in pngrtran.c png_do_scale_16_to_8. The values in the
- * macro were established by experiment (modifying the added value). The macro
- * has a second variant that takes a value already scaled by 255 and divides by
- * 65535 - this has a maximum error of .502. Over the range 0..65535*65535 it
- * only gives off-by-one errors and only for 0.5% (1 in 200) of the values.
- */
-#define PNG_DIV65535(v24) (((v24) + 32895) >> 16)
-#define PNG_DIV257(v16) PNG_DIV65535((png_uint_32)(v16) * 255)
-
-/* Added to libpng-1.2.6 JB */
-#define PNG_ROWBYTES(pixel_bits, width) \
- ((pixel_bits) >= 8 ? \
- ((png_size_t)(width) * (((png_size_t)(pixel_bits)) >> 3)) : \
- (( ((png_size_t)(width) * ((png_size_t)(pixel_bits))) + 7) >> 3) )
-
-/* PNG_OUT_OF_RANGE returns true if value is outside the range
- * ideal-delta..ideal+delta. Each argument is evaluated twice.
- * "ideal" and "delta" should be constants, normally simple
- * integers, "value" a variable. Added to libpng-1.2.6 JB
- */
-#define PNG_OUT_OF_RANGE(value, ideal, delta) \
- ( (value) < (ideal)-(delta) || (value) > (ideal)+(delta) )
-
-/* Conversions between fixed and floating point, only defined if
- * required (to make sure the code doesn't accidentally use float
- * when it is supposedly disabled.)
- */
-#ifdef PNG_FLOATING_POINT_SUPPORTED
-/* The floating point conversion can't overflow, though it can and
- * does lose accuracy relative to the original fixed point value.
- * In practice this doesn't matter because png_fixed_point only
- * stores numbers with very low precision. The png_ptr and s
- * arguments are unused by default but are there in case error
- * checking becomes a requirement.
- */
-#define png_float(png_ptr, fixed, s) (.00001 * (fixed))
-
-/* The fixed point conversion performs range checking and evaluates
- * its argument multiple times, so must be used with care. The
- * range checking uses the PNG specification values for a signed
- * 32 bit fixed point value except that the values are deliberately
- * rounded-to-zero to an integral value - 21474 (21474.83 is roughly
- * (2^31-1) * 100000). 's' is a string that describes the value being
- * converted.
- *
- * NOTE: this macro will raise a png_error if the range check fails,
- * therefore it is normally only appropriate to use this on values
- * that come from API calls or other sources where an out of range
- * error indicates a programming error, not a data error!
- *
- * NOTE: by default this is off - the macro is not used - because the
- * function call saves a lot of code.
- */
-#ifdef PNG_FIXED_POINT_MACRO_SUPPORTED
-#define png_fixed(png_ptr, fp, s) ((fp) <= 21474 && (fp) >= -21474 ?\
- ((png_fixed_point)(100000 * (fp))) : (png_fixed_error(png_ptr, s),0))
-#endif
-/* else the corresponding function is defined below, inside the scope of the
- * cplusplus test.
- */
-#endif
-
-/* Constants for known chunk types. If you need to add a chunk, define the name
- * here. For historical reasons these constants have the form png_<name>; i.e.
- * the prefix is lower case. Please use decimal values as the parameters to
- * match the ISO PNG specification and to avoid relying on the C locale
- * interpretation of character values.
- *
- * Prior to 1.5.6 these constants were strings, as of 1.5.6 png_uint_32 values
- * are computed and a new macro (PNG_STRING_FROM_CHUNK) added to allow a string
- * to be generated if required.
- *
- * PNG_32b correctly produces a value shifted by up to 24 bits, even on
- * architectures where (int) is only 16 bits.
- */
-#define PNG_32b(b,s) ((png_uint_32)(b) << (s))
-#define PNG_U32(b1,b2,b3,b4) \
- (PNG_32b(b1,24) | PNG_32b(b2,16) | PNG_32b(b3,8) | PNG_32b(b4,0))
-
-/* Constants for known chunk types.
- *
- * MAINTAINERS: If you need to add a chunk, define the name here.
- * For historical reasons these constants have the form png_<name>; i.e.
- * the prefix is lower case. Please use decimal values as the parameters to
- * match the ISO PNG specification and to avoid relying on the C locale
- * interpretation of character values. Please keep the list sorted.
- *
- * Notice that PNG_U32 is used to define a 32-bit value for the 4 byte chunk
- * type. In fact the specification does not express chunk types this way,
- * however using a 32-bit value means that the chunk type can be read from the
- * stream using exactly the same code as used for a 32-bit unsigned value and
- * can be examined far more efficiently (using one arithmetic compare).
- *
- * Prior to 1.5.6 the chunk type constants were expressed as C strings. The
- * libpng API still uses strings for 'unknown' chunks and a macro,
- * PNG_STRING_FROM_CHUNK, allows a string to be generated if required. Notice
- * that for portable code numeric values must still be used; the string "IHDR"
- * is not portable and neither is PNG_U32('I', 'H', 'D', 'R').
- *
- * In 1.7.0 the definitions will be made public in png.h to avoid having to
- * duplicate the same definitions in application code.
- */
-#define png_IDAT PNG_U32( 73, 68, 65, 84)
-#define png_IEND PNG_U32( 73, 69, 78, 68)
-#define png_IHDR PNG_U32( 73, 72, 68, 82)
-#define png_PLTE PNG_U32( 80, 76, 84, 69)
-#define png_bKGD PNG_U32( 98, 75, 71, 68)
-#define png_cHRM PNG_U32( 99, 72, 82, 77)
-#define png_fRAc PNG_U32(102, 82, 65, 99) /* registered, not defined */
-#define png_gAMA PNG_U32(103, 65, 77, 65)
-#define png_gIFg PNG_U32(103, 73, 70, 103)
-#define png_gIFt PNG_U32(103, 73, 70, 116) /* deprecated */
-#define png_gIFx PNG_U32(103, 73, 70, 120)
-#define png_hIST PNG_U32(104, 73, 83, 84)
-#define png_iCCP PNG_U32(105, 67, 67, 80)
-#define png_iTXt PNG_U32(105, 84, 88, 116)
-#define png_oFFs PNG_U32(111, 70, 70, 115)
-#define png_pCAL PNG_U32(112, 67, 65, 76)
-#define png_pHYs PNG_U32(112, 72, 89, 115)
-#define png_sBIT PNG_U32(115, 66, 73, 84)
-#define png_sCAL PNG_U32(115, 67, 65, 76)
-#define png_sPLT PNG_U32(115, 80, 76, 84)
-#define png_sRGB PNG_U32(115, 82, 71, 66)
-#define png_sTER PNG_U32(115, 84, 69, 82)
-#define png_tEXt PNG_U32(116, 69, 88, 116)
-#define png_tIME PNG_U32(116, 73, 77, 69)
-#define png_tRNS PNG_U32(116, 82, 78, 83)
-#define png_zTXt PNG_U32(122, 84, 88, 116)
-
-/* The following will work on (signed char*) strings, whereas the get_uint_32
- * macro will fail on top-bit-set values because of the sign extension.
- */
-#define PNG_CHUNK_FROM_STRING(s)\
- PNG_U32(0xff&(s)[0], 0xff&(s)[1], 0xff&(s)[2], 0xff&(s)[3])
-
-/* This uses (char), not (png_byte) to avoid warnings on systems where (char) is
- * signed and the argument is a (char[]) This macro will fail miserably on
- * systems where (char) is more than 8 bits.
- */
-#define PNG_STRING_FROM_CHUNK(s,c)\
- (void)(((char*)(s))[0]=(char)((c)>>24), ((char*)(s))[1]=(char)((c)>>16),\
- ((char*)(s))[2]=(char)((c)>>8), ((char*)(s))[3]=(char)((c)))
-
-/* Do the same but terminate with a null character. */
-#define PNG_CSTRING_FROM_CHUNK(s,c)\
- (void)(PNG_STRING_FROM_CHUNK(s,c), ((char*)(s))[4] = 0)
-
-/* Test on flag values as defined in the spec (section 5.4): */
-#define PNG_CHUNK_ANCILLARY(c) (1 & ((c) >> 29))
-#define PNG_CHUNK_CRITICAL(c) (!PNG_CHUNK_ANCILLARY(c))
-#define PNG_CHUNK_PRIVATE(c) (1 & ((c) >> 21))
-#define PNG_CHUNK_RESERVED(c) (1 & ((c) >> 13))
-#define PNG_CHUNK_SAFE_TO_COPY(c) (1 & ((c) >> 5))
-
-/* Gamma values (new at libpng-1.5.4): */
-#define PNG_GAMMA_MAC_OLD 151724 /* Assume '1.8' is really 2.2/1.45! */
-#define PNG_GAMMA_MAC_INVERSE 65909
-#define PNG_GAMMA_sRGB_INVERSE 45455
-
-/* Almost everything below is C specific; the #defines above can be used in
- * non-C code (so long as it is C-preprocessed) the rest of this stuff cannot.
- */
-#ifndef PNG_VERSION_INFO_ONLY
-
-#include "pngstruct.h"
-#include "pnginfo.h"
-
-/* Validate the include paths - the include path used to generate pnglibconf.h
- * must match that used in the build, or we must be using pnglibconf.h.prebuilt:
- */
-#if PNG_ZLIB_VERNUM != 0 && PNG_ZLIB_VERNUM != ZLIB_VERNUM
-# error ZLIB_VERNUM != PNG_ZLIB_VERNUM \
- "-I (include path) error: see the notes in pngpriv.h"
- /* This means that when pnglibconf.h was built the copy of zlib.h that it
- * used is not the same as the one being used here. Because the build of
- * libpng makes decisions to use inflateInit2 and inflateReset2 based on the
- * zlib version number and because this affects handling of certain broken
- * PNG files the -I directives must match.
- *
- * The most likely explanation is that you passed a -I in CFLAGS, this will
- * not work; all the preprocessor directories and in particular all the -I
- * directives must be in CPPFLAGS.
- */
-#endif
-
-/* This is used for 16 bit gamma tables -- only the top level pointers are
- * const; this could be changed:
- */
-typedef const png_uint_16p * png_const_uint_16pp;
-
-/* Added to libpng-1.5.7: sRGB conversion tables */
-#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) ||\
- defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
-#ifdef PNG_SIMPLIFIED_READ_SUPPORTED
-PNG_INTERNAL_DATA(const png_uint_16, png_sRGB_table, [256]);
- /* Convert from an sRGB encoded value 0..255 to a 16-bit linear value,
- * 0..65535. This table gives the closest 16-bit answers (no errors).
- */
-#endif
-
-PNG_INTERNAL_DATA(const png_uint_16, png_sRGB_base, [512]);
-PNG_INTERNAL_DATA(const png_byte, png_sRGB_delta, [512]);
-
-#define PNG_sRGB_FROM_LINEAR(linear) ((png_byte)((png_sRGB_base[(linear)>>15] +\
- ((((linear)&0x7fff)*png_sRGB_delta[(linear)>>15])>>12)) >> 8))
- /* Given a value 'linear' in the range 0..255*65535 calculate the 8-bit sRGB
- * encoded value with maximum error 0.646365. Note that the input is not a
- * 16-bit value; it has been multiplied by 255! */
-#endif /* PNG_SIMPLIFIED_READ/WRITE */
-
-
-/* Inhibit C++ name-mangling for libpng functions but not for system calls. */
-#ifdef __cplusplus
-extern "C" {
-#endif /* __cplusplus */
-
-/* Internal functions; these are not exported from a DLL however because they
- * are used within several of the C source files they have to be C extern.
- *
- * All of these functions must be declared with PNG_INTERNAL_FUNCTION.
- */
-
-/* Zlib support */
-#define PNG_UNEXPECTED_ZLIB_RETURN (-7)
-PNG_INTERNAL_FUNCTION(void, png_zstream_error,(png_structrp png_ptr, int ret),
- PNG_EMPTY);
- /* Used by the zlib handling functions to ensure that z_stream::msg is always
- * set before they return.
- */
-
-#ifdef PNG_WRITE_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_free_buffer_list,(png_structrp png_ptr,
- png_compression_bufferp *list),PNG_EMPTY);
- /* Free the buffer list used by the compressed write code. */
-#endif
-
-#if defined(PNG_FLOATING_POINT_SUPPORTED) && \
- !defined(PNG_FIXED_POINT_MACRO_SUPPORTED) && \
- (defined(PNG_gAMA_SUPPORTED) || defined(PNG_cHRM_SUPPORTED) || \
- defined(PNG_sCAL_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) || \
- defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)) || \
- (defined(PNG_sCAL_SUPPORTED) && \
- defined(PNG_FLOATING_ARITHMETIC_SUPPORTED))
-PNG_INTERNAL_FUNCTION(png_fixed_point,png_fixed,(png_const_structrp png_ptr,
- double fp, png_const_charp text),PNG_EMPTY);
-#endif
-
-/* Check the user version string for compatibility, returns false if the version
- * numbers aren't compatible.
- */
-PNG_INTERNAL_FUNCTION(int,png_user_version_check,(png_structrp png_ptr,
- png_const_charp user_png_ver),PNG_EMPTY);
-
-/* Internal base allocator - no messages, NULL on failure to allocate. This
- * does, however, call the application provided allocator and that could call
- * png_error (although that would be a bug in the application implementation.)
- */
-PNG_INTERNAL_FUNCTION(png_voidp,png_malloc_base,(png_const_structrp png_ptr,
- png_alloc_size_t size),PNG_ALLOCATED);
-
-#if defined(PNG_TEXT_SUPPORTED) || defined(PNG_sPLT_SUPPORTED) ||\
- defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED)
-/* Internal array allocator, outputs no error or warning messages on failure,
- * just returns NULL.
- */
-PNG_INTERNAL_FUNCTION(png_voidp,png_malloc_array,(png_const_structrp png_ptr,
- int nelements, size_t element_size),PNG_ALLOCATED);
-
-/* The same but an existing array is extended by add_elements. This function
- * also memsets the new elements to 0 and copies the old elements. The old
- * array is not freed or altered.
- */
-PNG_INTERNAL_FUNCTION(png_voidp,png_realloc_array,(png_const_structrp png_ptr,
- png_const_voidp array, int old_elements, int add_elements,
- size_t element_size),PNG_ALLOCATED);
-#endif /* text, sPLT or unknown chunks */
-
-/* Magic to create a struct when there is no struct to call the user supplied
- * memory allocators. Because error handling has not been set up the memory
- * handlers can't safely call png_error, but this is an obscure and undocumented
- * restriction so libpng has to assume that the 'free' handler, at least, might
- * call png_error.
- */
-PNG_INTERNAL_FUNCTION(png_structp,png_create_png_struct,
- (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
- png_error_ptr warn_fn, png_voidp mem_ptr, png_malloc_ptr malloc_fn,
- png_free_ptr free_fn),PNG_ALLOCATED);
-
-/* Free memory from internal libpng struct */
-PNG_INTERNAL_FUNCTION(void,png_destroy_png_struct,(png_structrp png_ptr),
- PNG_EMPTY);
-
-/* Free an allocated jmp_buf (always succeeds) */
-PNG_INTERNAL_FUNCTION(void,png_free_jmpbuf,(png_structrp png_ptr),PNG_EMPTY);
-
-/* Function to allocate memory for zlib. PNGAPI is disallowed. */
-PNG_INTERNAL_FUNCTION(voidpf,png_zalloc,(voidpf png_ptr, uInt items, uInt size),
- PNG_ALLOCATED);
-
-/* Function to free memory for zlib. PNGAPI is disallowed. */
-PNG_INTERNAL_FUNCTION(void,png_zfree,(voidpf png_ptr, voidpf ptr),PNG_EMPTY);
-
-/* Next four functions are used internally as callbacks. PNGCBAPI is required
- * but not PNG_EXPORT. PNGAPI added at libpng version 1.2.3, changed to
- * PNGCBAPI at 1.5.0
- */
-
-PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_default_read_data,(png_structp png_ptr,
- png_bytep data, png_size_t length),PNG_EMPTY);
-
-#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
-PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_push_fill_buffer,(png_structp png_ptr,
- png_bytep buffer, png_size_t length),PNG_EMPTY);
-#endif
-
-PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_default_write_data,(png_structp png_ptr,
- png_bytep data, png_size_t length),PNG_EMPTY);
-
-#ifdef PNG_WRITE_FLUSH_SUPPORTED
-# ifdef PNG_STDIO_SUPPORTED
-PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_default_flush,(png_structp png_ptr),
- PNG_EMPTY);
-# endif
-#endif
-
-/* Reset the CRC variable */
-PNG_INTERNAL_FUNCTION(void,png_reset_crc,(png_structrp png_ptr),PNG_EMPTY);
-
-/* Write the "data" buffer to whatever output you are using */
-PNG_INTERNAL_FUNCTION(void,png_write_data,(png_structrp png_ptr,
- png_const_bytep data, png_size_t length),PNG_EMPTY);
-
-/* Read and check the PNG file signature */
-PNG_INTERNAL_FUNCTION(void,png_read_sig,(png_structrp png_ptr,
- png_inforp info_ptr),PNG_EMPTY);
-
-/* Read the chunk header (length + type name) */
-PNG_INTERNAL_FUNCTION(png_uint_32,png_read_chunk_header,(png_structrp png_ptr),
- PNG_EMPTY);
-
-/* Read data from whatever input you are using into the "data" buffer */
-PNG_INTERNAL_FUNCTION(void,png_read_data,(png_structrp png_ptr, png_bytep data,
- png_size_t length),PNG_EMPTY);
-
-/* Read bytes into buf, and update png_ptr->crc */
-PNG_INTERNAL_FUNCTION(void,png_crc_read,(png_structrp png_ptr, png_bytep buf,
- png_uint_32 length),PNG_EMPTY);
-
-/* Read "skip" bytes, read the file crc, and (optionally) verify png_ptr->crc */
-PNG_INTERNAL_FUNCTION(int,png_crc_finish,(png_structrp png_ptr,
- png_uint_32 skip),PNG_EMPTY);
-
-/* Read the CRC from the file and compare it to the libpng calculated CRC */
-PNG_INTERNAL_FUNCTION(int,png_crc_error,(png_structrp png_ptr),PNG_EMPTY);
-
-/* Calculate the CRC over a section of data. Note that we are only
- * passing a maximum of 64K on systems that have this as a memory limit,
- * since this is the maximum buffer size we can specify.
- */
-PNG_INTERNAL_FUNCTION(void,png_calculate_crc,(png_structrp png_ptr,
- png_const_bytep ptr, png_size_t length),PNG_EMPTY);
-
-#ifdef PNG_WRITE_FLUSH_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_flush,(png_structrp png_ptr),PNG_EMPTY);
-#endif
-
-/* Write various chunks */
-
-/* Write the IHDR chunk, and update the png_struct with the necessary
- * information.
- */
-PNG_INTERNAL_FUNCTION(void,png_write_IHDR,(png_structrp png_ptr,
- png_uint_32 width, png_uint_32 height, int bit_depth, int color_type,
- int compression_method, int filter_method, int interlace_method),PNG_EMPTY);
-
-PNG_INTERNAL_FUNCTION(void,png_write_PLTE,(png_structrp png_ptr,
- png_const_colorp palette, png_uint_32 num_pal),PNG_EMPTY);
-
-PNG_INTERNAL_FUNCTION(void,png_compress_IDAT,(png_structrp png_ptr,
- png_const_bytep row_data, png_alloc_size_t row_data_length, int flush),
- PNG_EMPTY);
-
-PNG_INTERNAL_FUNCTION(void,png_write_IEND,(png_structrp png_ptr),PNG_EMPTY);
-
-#ifdef PNG_WRITE_gAMA_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_write_gAMA_fixed,(png_structrp png_ptr,
- png_fixed_point file_gamma),PNG_EMPTY);
-#endif
-
-#ifdef PNG_WRITE_sBIT_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_write_sBIT,(png_structrp png_ptr,
- png_const_color_8p sbit, int color_type),PNG_EMPTY);
-#endif
-
-#ifdef PNG_WRITE_cHRM_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_write_cHRM_fixed,(png_structrp png_ptr,
- const png_xy *xy), PNG_EMPTY);
- /* The xy value must have been previously validated */
-#endif
-
-#ifdef PNG_WRITE_sRGB_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_write_sRGB,(png_structrp png_ptr,
- int intent),PNG_EMPTY);
-#endif
-
-#ifdef PNG_WRITE_iCCP_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_write_iCCP,(png_structrp png_ptr,
- png_const_charp name, png_const_bytep profile), PNG_EMPTY);
- /* The profile must have been previously validated for correctness, the
- * length comes from the first four bytes. Only the base, deflate,
- * compression is supported.
- */
-#endif
-
-#ifdef PNG_WRITE_sPLT_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_write_sPLT,(png_structrp png_ptr,
- png_const_sPLT_tp palette),PNG_EMPTY);
-#endif
-
-#ifdef PNG_WRITE_tRNS_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_write_tRNS,(png_structrp png_ptr,
- png_const_bytep trans, png_const_color_16p values, int number,
- int color_type),PNG_EMPTY);
-#endif
-
-#ifdef PNG_WRITE_bKGD_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_write_bKGD,(png_structrp png_ptr,
- png_const_color_16p values, int color_type),PNG_EMPTY);
-#endif
-
-#ifdef PNG_WRITE_hIST_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_write_hIST,(png_structrp png_ptr,
- png_const_uint_16p hist, int num_hist),PNG_EMPTY);
-#endif
-
-/* Chunks that have keywords */
-#ifdef PNG_WRITE_tEXt_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_write_tEXt,(png_structrp png_ptr,
- png_const_charp key, png_const_charp text, png_size_t text_len),PNG_EMPTY);
-#endif
-
-#ifdef PNG_WRITE_zTXt_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_write_zTXt,(png_structrp png_ptr, png_const_charp
- key, png_const_charp text, png_size_t text_len, int compression),PNG_EMPTY);
-#endif
-
-#ifdef PNG_WRITE_iTXt_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_write_iTXt,(png_structrp png_ptr,
- int compression, png_const_charp key, png_const_charp lang,
- png_const_charp lang_key, png_const_charp text),PNG_EMPTY);
-#endif
-
-#ifdef PNG_TEXT_SUPPORTED /* Added at version 1.0.14 and 1.2.4 */
-PNG_INTERNAL_FUNCTION(int,png_set_text_2,(png_const_structrp png_ptr,
- png_inforp info_ptr, png_const_textp text_ptr, int num_text),PNG_EMPTY);
-#endif
-
-#ifdef PNG_WRITE_oFFs_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_write_oFFs,(png_structrp png_ptr,
- png_int_32 x_offset, png_int_32 y_offset, int unit_type),PNG_EMPTY);
-#endif
-
-#ifdef PNG_WRITE_pCAL_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_write_pCAL,(png_structrp png_ptr,
- png_charp purpose, png_int_32 X0, png_int_32 X1, int type, int nparams,
- png_const_charp units, png_charpp params),PNG_EMPTY);
-#endif
-
-#ifdef PNG_WRITE_pHYs_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_write_pHYs,(png_structrp png_ptr,
- png_uint_32 x_pixels_per_unit, png_uint_32 y_pixels_per_unit,
- int unit_type),PNG_EMPTY);
-#endif
-
-#ifdef PNG_WRITE_tIME_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_write_tIME,(png_structrp png_ptr,
- png_const_timep mod_time),PNG_EMPTY);
-#endif
-
-#ifdef PNG_WRITE_sCAL_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_write_sCAL_s,(png_structrp png_ptr,
- int unit, png_const_charp width, png_const_charp height),PNG_EMPTY);
-#endif
-
-/* Called when finished processing a row of data */
-PNG_INTERNAL_FUNCTION(void,png_write_finish_row,(png_structrp png_ptr),
- PNG_EMPTY);
-
-/* Internal use only. Called before first row of data */
-PNG_INTERNAL_FUNCTION(void,png_write_start_row,(png_structrp png_ptr),
- PNG_EMPTY);
-
-/* Combine a row of data, dealing with alpha, etc. if requested. 'row' is an
- * array of png_ptr->width pixels. If the image is not interlaced or this
- * is the final pass this just does a memcpy, otherwise the "display" flag
- * is used to determine whether to copy pixels that are not in the current pass.
- *
- * Because 'png_do_read_interlace' (below) replicates pixels this allows this
- * function to achieve the documented 'blocky' appearance during interlaced read
- * if display is 1 and the 'sparkle' appearance, where existing pixels in 'row'
- * are not changed if they are not in the current pass, when display is 0.
- *
- * 'display' must be 0 or 1, otherwise the memcpy will be done regardless.
- *
- * The API always reads from the png_struct row buffer and always assumes that
- * it is full width (png_do_read_interlace has already been called.)
- *
- * This function is only ever used to write to row buffers provided by the
- * caller of the relevant libpng API and the row must have already been
- * transformed by the read transformations.
- *
- * The PNG_USE_COMPILE_TIME_MASKS option causes generation of pre-computed
- * bitmasks for use within the code, otherwise runtime generated masks are used.
- * The default is compile time masks.
- */
-#ifndef PNG_USE_COMPILE_TIME_MASKS
-# define PNG_USE_COMPILE_TIME_MASKS 1
-#endif
-PNG_INTERNAL_FUNCTION(void,png_combine_row,(png_const_structrp png_ptr,
- png_bytep row, int display),PNG_EMPTY);
-
-#ifdef PNG_READ_INTERLACING_SUPPORTED
-/* Expand an interlaced row: the 'row_info' describes the pass data that has
- * been read in and must correspond to the pixels in 'row', the pixels are
- * expanded (moved apart) in 'row' to match the final layout, when doing this
- * the pixels are *replicated* to the intervening space. This is essential for
- * the correct operation of png_combine_row, above.
- */
-PNG_INTERNAL_FUNCTION(void,png_do_read_interlace,(png_row_infop row_info,
- png_bytep row, int pass, png_uint_32 transformations),PNG_EMPTY);
-#endif
-
-/* GRR TO DO (2.0 or whenever): simplify other internal calling interfaces */
-
-#ifdef PNG_WRITE_INTERLACING_SUPPORTED
-/* Grab pixels out of a row for an interlaced pass */
-PNG_INTERNAL_FUNCTION(void,png_do_write_interlace,(png_row_infop row_info,
- png_bytep row, int pass),PNG_EMPTY);
-#endif
-
-/* Unfilter a row: check the filter value before calling this, there is no point
- * calling it for PNG_FILTER_VALUE_NONE.
- */
-PNG_INTERNAL_FUNCTION(void,png_read_filter_row,(png_structrp pp, png_row_infop
- row_info, png_bytep row, png_const_bytep prev_row, int filter),PNG_EMPTY);
-
-PNG_INTERNAL_FUNCTION(void,png_read_filter_row_up_neon,(png_row_infop row_info,
- png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
-PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub3_neon,(png_row_infop
- row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
-PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub4_neon,(png_row_infop
- row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
-PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg3_neon,(png_row_infop
- row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
-PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg4_neon,(png_row_infop
- row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
-PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth3_neon,(png_row_infop
- row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
-PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_neon,(png_row_infop
- row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
-
-/* Choose the best filter to use and filter the row data */
-PNG_INTERNAL_FUNCTION(void,png_write_find_filter,(png_structrp png_ptr,
- png_row_infop row_info),PNG_EMPTY);
-
-#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_read_IDAT_data,(png_structrp png_ptr,
- png_bytep output, png_alloc_size_t avail_out),PNG_EMPTY);
- /* Read 'avail_out' bytes of data from the IDAT stream. If the output buffer
- * is NULL the function checks, instead, for the end of the stream. In this
- * case a benign error will be issued if the stream end is not found or if
- * extra data has to be consumed.
- */
-PNG_INTERNAL_FUNCTION(void,png_read_finish_IDAT,(png_structrp png_ptr),
- PNG_EMPTY);
- /* This cleans up when the IDAT LZ stream does not end when the last image
- * byte is read; there is still some pending input.
- */
-
-PNG_INTERNAL_FUNCTION(void,png_read_finish_row,(png_structrp png_ptr),
- PNG_EMPTY);
- /* Finish a row while reading, dealing with interlacing passes, etc. */
-#endif
-
-/* Initialize the row buffers, etc. */
-PNG_INTERNAL_FUNCTION(void,png_read_start_row,(png_structrp png_ptr),PNG_EMPTY);
-
-#ifdef PNG_READ_TRANSFORMS_SUPPORTED
-/* Optional call to update the users info structure */
-PNG_INTERNAL_FUNCTION(void,png_read_transform_info,(png_structrp png_ptr,
- png_inforp info_ptr),PNG_EMPTY);
-#endif
-
-/* These are the functions that do the transformations */
-#ifdef PNG_READ_FILLER_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_do_read_filler,(png_row_infop row_info,
- png_bytep row, png_uint_32 filler, png_uint_32 flags),PNG_EMPTY);
-#endif
-
-#ifdef PNG_READ_SWAP_ALPHA_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_do_read_swap_alpha,(png_row_infop row_info,
- png_bytep row),PNG_EMPTY);
-#endif
-
-#ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_do_write_swap_alpha,(png_row_infop row_info,
- png_bytep row),PNG_EMPTY);
-#endif
-
-#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_do_read_invert_alpha,(png_row_infop row_info,
- png_bytep row),PNG_EMPTY);
-#endif
-
-#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_do_write_invert_alpha,(png_row_infop row_info,
- png_bytep row),PNG_EMPTY);
-#endif
-
-#if defined(PNG_WRITE_FILLER_SUPPORTED) || \
- defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
-PNG_INTERNAL_FUNCTION(void,png_do_strip_channel,(png_row_infop row_info,
- png_bytep row, int at_start),PNG_EMPTY);
-#endif
-
-#ifdef PNG_16BIT_SUPPORTED
-#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
-PNG_INTERNAL_FUNCTION(void,png_do_swap,(png_row_infop row_info,
- png_bytep row),PNG_EMPTY);
-#endif
-#endif
-
-#if defined(PNG_READ_PACKSWAP_SUPPORTED) || \
- defined(PNG_WRITE_PACKSWAP_SUPPORTED)
-PNG_INTERNAL_FUNCTION(void,png_do_packswap,(png_row_infop row_info,
- png_bytep row),PNG_EMPTY);
-#endif
-
-#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
-PNG_INTERNAL_FUNCTION(int,png_do_rgb_to_gray,(png_structrp png_ptr,
- png_row_infop row_info, png_bytep row),PNG_EMPTY);
-#endif
-
-#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_do_gray_to_rgb,(png_row_infop row_info,
- png_bytep row),PNG_EMPTY);
-#endif
-
-#ifdef PNG_READ_PACK_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_do_unpack,(png_row_infop row_info,
- png_bytep row),PNG_EMPTY);
-#endif
-
-#ifdef PNG_READ_SHIFT_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_do_unshift,(png_row_infop row_info,
- png_bytep row, png_const_color_8p sig_bits),PNG_EMPTY);
-#endif
-
-#if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
-PNG_INTERNAL_FUNCTION(void,png_do_invert,(png_row_infop row_info,
- png_bytep row),PNG_EMPTY);
-#endif
-
-#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_do_scale_16_to_8,(png_row_infop row_info,
- png_bytep row),PNG_EMPTY);
-#endif
-
-#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_do_chop,(png_row_infop row_info,
- png_bytep row),PNG_EMPTY);
-#endif
-
-#ifdef PNG_READ_QUANTIZE_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_do_quantize,(png_row_infop row_info,
- png_bytep row, png_const_bytep palette_lookup,
- png_const_bytep quantize_lookup),PNG_EMPTY);
-
-# ifdef PNG_CORRECT_PALETTE_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_correct_palette,(png_structrp png_ptr,
- png_colorp palette, int num_palette),PNG_EMPTY);
-# endif
-#endif
-
-#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
-PNG_INTERNAL_FUNCTION(void,png_do_bgr,(png_row_infop row_info,
- png_bytep row),PNG_EMPTY);
-#endif
-
-#ifdef PNG_WRITE_PACK_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_do_pack,(png_row_infop row_info,
- png_bytep row, png_uint_32 bit_depth),PNG_EMPTY);
-#endif
-
-#ifdef PNG_WRITE_SHIFT_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_do_shift,(png_row_infop row_info,
- png_bytep row, png_const_color_8p bit_depth),PNG_EMPTY);
-#endif
-
-#if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\
- defined(PNG_READ_ALPHA_MODE_SUPPORTED)
-PNG_INTERNAL_FUNCTION(void,png_do_compose,(png_row_infop row_info,
- png_bytep row, png_structrp png_ptr),PNG_EMPTY);
-#endif
-
-#ifdef PNG_READ_GAMMA_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_do_gamma,(png_row_infop row_info,
- png_bytep row, png_structrp png_ptr),PNG_EMPTY);
-#endif
-
-#ifdef PNG_READ_ALPHA_MODE_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_do_encode_alpha,(png_row_infop row_info,
- png_bytep row, png_structrp png_ptr),PNG_EMPTY);
-#endif
-
-#ifdef PNG_READ_EXPAND_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_do_expand_palette,(png_row_infop row_info,
- png_bytep row, png_const_colorp palette, png_const_bytep trans,
- int num_trans),PNG_EMPTY);
-PNG_INTERNAL_FUNCTION(void,png_do_expand,(png_row_infop row_info,
- png_bytep row, png_const_color_16p trans_color),PNG_EMPTY);
-#endif
-
-#ifdef PNG_READ_EXPAND_16_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_do_expand_16,(png_row_infop row_info,
- png_bytep row),PNG_EMPTY);
-#endif
-
-/* The following decodes the appropriate chunks, and does error correction,
- * then calls the appropriate callback for the chunk if it is valid.
- */
-
-/* Decode the IHDR chunk */
-PNG_INTERNAL_FUNCTION(void,png_handle_IHDR,(png_structrp png_ptr,
- png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
-PNG_INTERNAL_FUNCTION(void,png_handle_PLTE,(png_structrp png_ptr,
- png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
-PNG_INTERNAL_FUNCTION(void,png_handle_IEND,(png_structrp png_ptr,
- png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
-
-#ifdef PNG_READ_bKGD_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_handle_bKGD,(png_structrp png_ptr,
- png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
-#endif
-
-#ifdef PNG_READ_cHRM_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_handle_cHRM,(png_structrp png_ptr,
- png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
-#endif
-
-#ifdef PNG_READ_gAMA_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_handle_gAMA,(png_structrp png_ptr,
- png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
-#endif
-
-#ifdef PNG_READ_hIST_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_handle_hIST,(png_structrp png_ptr,
- png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
-#endif
-
-#ifdef PNG_READ_iCCP_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_handle_iCCP,(png_structrp png_ptr,
- png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
-#endif /* PNG_READ_iCCP_SUPPORTED */
-
-#ifdef PNG_READ_iTXt_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_handle_iTXt,(png_structrp png_ptr,
- png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
-#endif
-
-#ifdef PNG_READ_oFFs_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_handle_oFFs,(png_structrp png_ptr,
- png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
-#endif
-
-#ifdef PNG_READ_pCAL_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_handle_pCAL,(png_structrp png_ptr,
- png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
-#endif
-
-#ifdef PNG_READ_pHYs_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_handle_pHYs,(png_structrp png_ptr,
- png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
-#endif
-
-#ifdef PNG_READ_sBIT_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_handle_sBIT,(png_structrp png_ptr,
- png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
-#endif
-
-#ifdef PNG_READ_sCAL_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_handle_sCAL,(png_structrp png_ptr,
- png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
-#endif
-
-#ifdef PNG_READ_sPLT_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_handle_sPLT,(png_structrp png_ptr,
- png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
-#endif /* PNG_READ_sPLT_SUPPORTED */
-
-#ifdef PNG_READ_sRGB_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_handle_sRGB,(png_structrp png_ptr,
- png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
-#endif
-
-#ifdef PNG_READ_tEXt_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_handle_tEXt,(png_structrp png_ptr,
- png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
-#endif
-
-#ifdef PNG_READ_tIME_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_handle_tIME,(png_structrp png_ptr,
- png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
-#endif
-
-#ifdef PNG_READ_tRNS_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_handle_tRNS,(png_structrp png_ptr,
- png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
-#endif
-
-#ifdef PNG_READ_zTXt_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_handle_zTXt,(png_structrp png_ptr,
- png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
-#endif
-
-PNG_INTERNAL_FUNCTION(void,png_check_chunk_name,(png_structrp png_ptr,
- png_uint_32 chunk_name),PNG_EMPTY);
-
-#ifdef PNG_READ_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_handle_unknown,(png_structrp png_ptr,
- png_inforp info_ptr, png_uint_32 length, int keep),PNG_EMPTY);
- /* This is the function that gets called for unknown chunks. The 'keep'
- * argument is either non-zero for a known chunk that has been set to be
- * handled as unknown or zero for an unknown chunk. By default the function
- * just skips the chunk or errors out if it is critical.
- */
-
-#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
-#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
-PNG_INTERNAL_FUNCTION(int,png_chunk_unknown_handling,
- (png_const_structrp png_ptr, png_uint_32 chunk_name),PNG_EMPTY);
- /* Exactly as the API png_handle_as_unknown() except that the argument is a
- * 32-bit chunk name, not a string.
- */
-#endif
-#endif /* PNG_READ_UNKNOWN_CHUNKS_SUPPORTED */
-#endif /* PNG_READ_SUPPORTED */
-
-/* Handle the transformations for reading and writing */
-#ifdef PNG_READ_TRANSFORMS_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_do_read_transformations,(png_structrp png_ptr,
- png_row_infop row_info),PNG_EMPTY);
-#endif
-#ifdef PNG_WRITE_TRANSFORMS_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_do_write_transformations,(png_structrp png_ptr,
- png_row_infop row_info),PNG_EMPTY);
-#endif
-
-#ifdef PNG_READ_TRANSFORMS_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_init_read_transformations,(png_structrp png_ptr),
- PNG_EMPTY);
-#endif
-
-#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_push_read_chunk,(png_structrp png_ptr,
- png_inforp info_ptr),PNG_EMPTY);
-PNG_INTERNAL_FUNCTION(void,png_push_read_sig,(png_structrp png_ptr,
- png_inforp info_ptr),PNG_EMPTY);
-PNG_INTERNAL_FUNCTION(void,png_push_check_crc,(png_structrp png_ptr),PNG_EMPTY);
-PNG_INTERNAL_FUNCTION(void,png_push_crc_skip,(png_structrp png_ptr,
- png_uint_32 length),PNG_EMPTY);
-PNG_INTERNAL_FUNCTION(void,png_push_crc_finish,(png_structrp png_ptr),
- PNG_EMPTY);
-PNG_INTERNAL_FUNCTION(void,png_push_save_buffer,(png_structrp png_ptr),
- PNG_EMPTY);
-PNG_INTERNAL_FUNCTION(void,png_push_restore_buffer,(png_structrp png_ptr,
- png_bytep buffer, png_size_t buffer_length),PNG_EMPTY);
-PNG_INTERNAL_FUNCTION(void,png_push_read_IDAT,(png_structrp png_ptr),PNG_EMPTY);
-PNG_INTERNAL_FUNCTION(void,png_process_IDAT_data,(png_structrp png_ptr,
- png_bytep buffer, png_size_t buffer_length),PNG_EMPTY);
-PNG_INTERNAL_FUNCTION(void,png_push_process_row,(png_structrp png_ptr),
- PNG_EMPTY);
-PNG_INTERNAL_FUNCTION(void,png_push_handle_unknown,(png_structrp png_ptr,
- png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
-PNG_INTERNAL_FUNCTION(void,png_push_have_info,(png_structrp png_ptr,
- png_inforp info_ptr),PNG_EMPTY);
-PNG_INTERNAL_FUNCTION(void,png_push_have_end,(png_structrp png_ptr,
- png_inforp info_ptr),PNG_EMPTY);
-PNG_INTERNAL_FUNCTION(void,png_push_have_row,(png_structrp png_ptr,
- png_bytep row),PNG_EMPTY);
-PNG_INTERNAL_FUNCTION(void,png_push_read_end,(png_structrp png_ptr,
- png_inforp info_ptr),PNG_EMPTY);
-PNG_INTERNAL_FUNCTION(void,png_process_some_data,(png_structrp png_ptr,
- png_inforp info_ptr),PNG_EMPTY);
-PNG_INTERNAL_FUNCTION(void,png_read_push_finish_row,(png_structrp png_ptr),
- PNG_EMPTY);
-# ifdef PNG_READ_tEXt_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_push_handle_tEXt,(png_structrp png_ptr,
- png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
-PNG_INTERNAL_FUNCTION(void,png_push_read_tEXt,(png_structrp png_ptr,
- png_inforp info_ptr),PNG_EMPTY);
-# endif
-# ifdef PNG_READ_zTXt_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_push_handle_zTXt,(png_structrp png_ptr,
- png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
-PNG_INTERNAL_FUNCTION(void,png_push_read_zTXt,(png_structrp png_ptr,
- png_inforp info_ptr),PNG_EMPTY);
-# endif
-# ifdef PNG_READ_iTXt_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_push_handle_iTXt,(png_structrp png_ptr,
- png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
-PNG_INTERNAL_FUNCTION(void,png_push_read_iTXt,(png_structrp png_ptr,
- png_inforp info_ptr),PNG_EMPTY);
-# endif
-
-#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
-
-#ifdef PNG_MNG_FEATURES_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_do_read_intrapixel,(png_row_infop row_info,
- png_bytep row),PNG_EMPTY);
-PNG_INTERNAL_FUNCTION(void,png_do_write_intrapixel,(png_row_infop row_info,
- png_bytep row),PNG_EMPTY);
-#endif
-
-/* Added at libpng version 1.6.0 */
-#ifdef PNG_GAMMA_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_colorspace_set_gamma,(png_const_structrp png_ptr,
- png_colorspacerp colorspace, png_fixed_point gAMA), PNG_EMPTY);
- /* Set the colorspace gamma with a value provided by the application or by
- * the gAMA chunk on read. The value will override anything set by an ICC
- * profile.
- */
-
-PNG_INTERNAL_FUNCTION(void,png_colorspace_sync_info,(png_const_structrp png_ptr,
- png_inforp info_ptr), PNG_EMPTY);
- /* Synchronize the info 'valid' flags with the colorspace */
-
-PNG_INTERNAL_FUNCTION(void,png_colorspace_sync,(png_const_structrp png_ptr,
- png_inforp info_ptr), PNG_EMPTY);
- /* Copy the png_struct colorspace to the info_struct and call the above to
- * synchronize the flags. Checks for NULL info_ptr and does nothing.
- */
-#endif
-
-/* Added at libpng version 1.4.0 */
-#ifdef PNG_COLORSPACE_SUPPORTED
-/* These internal functions are for maintaining the colorspace structure within
- * a png_info or png_struct (or, indeed, both).
- */
-PNG_INTERNAL_FUNCTION(int,png_colorspace_set_chromaticities,
- (png_const_structrp png_ptr, png_colorspacerp colorspace, const png_xy *xy,
- int preferred), PNG_EMPTY);
-
-PNG_INTERNAL_FUNCTION(int,png_colorspace_set_endpoints,
- (png_const_structrp png_ptr, png_colorspacerp colorspace, const png_XYZ *XYZ,
- int preferred), PNG_EMPTY);
-
-#ifdef PNG_sRGB_SUPPORTED
-PNG_INTERNAL_FUNCTION(int,png_colorspace_set_sRGB,(png_const_structrp png_ptr,
- png_colorspacerp colorspace, int intent), PNG_EMPTY);
- /* This does set the colorspace gAMA and cHRM values too, but doesn't set the
- * flags to write them, if it returns false there was a problem and an error
- * message has already been output (but the colorspace may still need to be
- * synced to record the invalid flag).
- */
-#endif /* sRGB */
-
-#ifdef PNG_iCCP_SUPPORTED
-PNG_INTERNAL_FUNCTION(int,png_colorspace_set_ICC,(png_const_structrp png_ptr,
- png_colorspacerp colorspace, png_const_charp name,
- png_uint_32 profile_length, png_const_bytep profile, int color_type),
- PNG_EMPTY);
- /* The 'name' is used for information only */
-
-/* Routines for checking parts of an ICC profile. */
-PNG_INTERNAL_FUNCTION(int,png_icc_check_length,(png_const_structrp png_ptr,
- png_colorspacerp colorspace, png_const_charp name,
- png_uint_32 profile_length), PNG_EMPTY);
-PNG_INTERNAL_FUNCTION(int,png_icc_check_header,(png_const_structrp png_ptr,
- png_colorspacerp colorspace, png_const_charp name,
- png_uint_32 profile_length,
- png_const_bytep profile /* first 132 bytes only */, int color_type),
- PNG_EMPTY);
-PNG_INTERNAL_FUNCTION(int,png_icc_check_tag_table,(png_const_structrp png_ptr,
- png_colorspacerp colorspace, png_const_charp name,
- png_uint_32 profile_length,
- png_const_bytep profile /* header plus whole tag table */), PNG_EMPTY);
-#ifdef PNG_sRGB_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_icc_set_sRGB,(
- png_const_structrp png_ptr, png_colorspacerp colorspace,
- png_const_bytep profile, uLong adler), PNG_EMPTY);
- /* 'adler' is the Adler32 checksum of the uncompressed profile data. It may
- * be zero to indicate that it is not available. It is used, if provided,
- * as a fast check on the profile when checking to see if it is sRGB.
- */
-#endif
-#endif /* iCCP */
-
-#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_colorspace_set_rgb_coefficients,
- (png_structrp png_ptr), PNG_EMPTY);
- /* Set the rgb_to_gray coefficients from the colorspace Y values */
-#endif /* READ_RGB_TO_GRAY */
-#endif /* COLORSPACE */
-
-/* Added at libpng version 1.4.0 */
-PNG_INTERNAL_FUNCTION(void,png_check_IHDR,(png_const_structrp png_ptr,
- png_uint_32 width, png_uint_32 height, int bit_depth,
- int color_type, int interlace_type, int compression_type,
- int filter_type),PNG_EMPTY);
-
-/* Added at libpng version 1.5.10 */
-#if defined(PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED) || \
- defined(PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED)
-PNG_INTERNAL_FUNCTION(void,png_do_check_palette_indexes,
- (png_structrp png_ptr, png_row_infop row_info),PNG_EMPTY);
-#endif
-
-#if defined(PNG_FLOATING_POINT_SUPPORTED) && defined(PNG_ERROR_TEXT_SUPPORTED)
-PNG_INTERNAL_FUNCTION(void,png_fixed_error,(png_const_structrp png_ptr,
- png_const_charp name),PNG_NORETURN);
-#endif
-
-/* Puts 'string' into 'buffer' at buffer[pos], taking care never to overwrite
- * the end. Always leaves the buffer nul terminated. Never errors out (and
- * there is no error code.)
- */
-PNG_INTERNAL_FUNCTION(size_t,png_safecat,(png_charp buffer, size_t bufsize,
- size_t pos, png_const_charp string),PNG_EMPTY);
-
-/* Various internal functions to handle formatted warning messages, currently
- * only implemented for warnings.
- */
-#if defined(PNG_WARNINGS_SUPPORTED) || defined(PNG_TIME_RFC1123_SUPPORTED)
-/* Utility to dump an unsigned value into a buffer, given a start pointer and
- * and end pointer (which should point just *beyond* the end of the buffer!)
- * Returns the pointer to the start of the formatted string. This utility only
- * does unsigned values.
- */
-PNG_INTERNAL_FUNCTION(png_charp,png_format_number,(png_const_charp start,
- png_charp end, int format, png_alloc_size_t number),PNG_EMPTY);
-
-/* Convenience macro that takes an array: */
-#define PNG_FORMAT_NUMBER(buffer,format,number) \
- png_format_number(buffer, buffer + (sizeof buffer), format, number)
-
-/* Suggested size for a number buffer (enough for 64 bits and a sign!) */
-#define PNG_NUMBER_BUFFER_SIZE 24
-
-/* These are the integer formats currently supported, the name is formed from
- * the standard printf(3) format string.
- */
-#define PNG_NUMBER_FORMAT_u 1 /* chose unsigned API! */
-#define PNG_NUMBER_FORMAT_02u 2
-#define PNG_NUMBER_FORMAT_d 1 /* chose signed API! */
-#define PNG_NUMBER_FORMAT_02d 2
-#define PNG_NUMBER_FORMAT_x 3
-#define PNG_NUMBER_FORMAT_02x 4
-#define PNG_NUMBER_FORMAT_fixed 5 /* choose the signed API */
-#endif
-
-#ifdef PNG_WARNINGS_SUPPORTED
-/* New defines and members adding in libpng-1.5.4 */
-# define PNG_WARNING_PARAMETER_SIZE 32
-# define PNG_WARNING_PARAMETER_COUNT 8 /* Maximum 9; see pngerror.c */
-
-/* An l-value of this type has to be passed to the APIs below to cache the
- * values of the parameters to a formatted warning message.
- */
-typedef char png_warning_parameters[PNG_WARNING_PARAMETER_COUNT][
- PNG_WARNING_PARAMETER_SIZE];
-
-PNG_INTERNAL_FUNCTION(void,png_warning_parameter,(png_warning_parameters p,
- int number, png_const_charp string),PNG_EMPTY);
- /* Parameters are limited in size to PNG_WARNING_PARAMETER_SIZE characters,
- * including the trailing '\0'.
- */
-PNG_INTERNAL_FUNCTION(void,png_warning_parameter_unsigned,
- (png_warning_parameters p, int number, int format, png_alloc_size_t value),
- PNG_EMPTY);
- /* Use png_alloc_size_t because it is an unsigned type as big as any we
- * need to output. Use the following for a signed value.
- */
-PNG_INTERNAL_FUNCTION(void,png_warning_parameter_signed,
- (png_warning_parameters p, int number, int format, png_int_32 value),
- PNG_EMPTY);
-
-PNG_INTERNAL_FUNCTION(void,png_formatted_warning,(png_const_structrp png_ptr,
- png_warning_parameters p, png_const_charp message),PNG_EMPTY);
- /* 'message' follows the X/Open approach of using @1, @2 to insert
- * parameters previously supplied using the above functions. Errors in
- * specifying the parameters will simply result in garbage substitutions.
- */
-#endif
-
-#ifdef PNG_BENIGN_ERRORS_SUPPORTED
-/* Application errors (new in 1.6); use these functions (declared below) for
- * errors in the parameters or order of API function calls on read. The
- * 'warning' should be used for an error that can be handled completely; the
- * 'error' for one which can be handled safely but which may lose application
- * information or settings.
- *
- * By default these both result in a png_error call prior to release, while in a
- * released version the 'warning' is just a warning. However if the application
- * explicitly disables benign errors (explicitly permitting the code to lose
- * information) they both turn into warnings.
- *
- * If benign errors aren't supported they end up as the corresponding base call
- * (png_warning or png_error.)
- */
-PNG_INTERNAL_FUNCTION(void,png_app_warning,(png_const_structrp png_ptr,
- png_const_charp message),PNG_EMPTY);
- /* The application provided invalid parameters to an API function or called
- * an API function at the wrong time, libpng can completely recover.
- */
-
-PNG_INTERNAL_FUNCTION(void,png_app_error,(png_const_structrp png_ptr,
- png_const_charp message),PNG_EMPTY);
- /* As above but libpng will ignore the call, or attempt some other partial
- * recovery from the error.
- */
-#else
-# define png_app_warning(pp,s) png_warning(pp,s)
-# define png_app_error(pp,s) png_error(pp,s)
-#endif
-
-PNG_INTERNAL_FUNCTION(void,png_chunk_report,(png_const_structrp png_ptr,
- png_const_charp message, int error),PNG_EMPTY);
- /* Report a recoverable issue in chunk data. On read this is used to report
- * a problem found while reading a particular chunk and the
- * png_chunk_benign_error or png_chunk_warning function is used as
- * appropriate. On write this is used to report an error that comes from
- * data set via an application call to a png_set_ API and png_app_error or
- * png_app_warning is used as appropriate.
- *
- * The 'error' parameter must have one of the following values:
- */
-#define PNG_CHUNK_WARNING 0 /* never an error */
-#define PNG_CHUNK_WRITE_ERROR 1 /* an error only on write */
-#define PNG_CHUNK_ERROR 2 /* always an error */
-
-/* ASCII to FP interfaces, currently only implemented if sCAL
- * support is required.
- */
-#if defined(PNG_sCAL_SUPPORTED)
-/* MAX_DIGITS is actually the maximum number of characters in an sCAL
- * width or height, derived from the precision (number of significant
- * digits - a build time settable option) and assumptions about the
- * maximum ridiculous exponent.
- */
-#define PNG_sCAL_MAX_DIGITS (PNG_sCAL_PRECISION+1/*.*/+1/*E*/+10/*exponent*/)
-
-#ifdef PNG_FLOATING_POINT_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_ascii_from_fp,(png_const_structrp png_ptr,
- png_charp ascii, png_size_t size, double fp, unsigned int precision),
- PNG_EMPTY);
-#endif /* FLOATING_POINT */
-
-#ifdef PNG_FIXED_POINT_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_ascii_from_fixed,(png_const_structrp png_ptr,
- png_charp ascii, png_size_t size, png_fixed_point fp),PNG_EMPTY);
-#endif /* FIXED_POINT */
-#endif /* sCAL */
-
-#if defined(PNG_sCAL_SUPPORTED) || defined(PNG_pCAL_SUPPORTED)
-/* An internal API to validate the format of a floating point number.
- * The result is the index of the next character. If the number is
- * not valid it will be the index of a character in the supposed number.
- *
- * The format of a number is defined in the PNG extensions specification
- * and this API is strictly conformant to that spec, not anyone elses!
- *
- * The format as a regular expression is:
- *
- * [+-]?[0-9]+.?([Ee][+-]?[0-9]+)?
- *
- * or:
- *
- * [+-]?.[0-9]+(.[0-9]+)?([Ee][+-]?[0-9]+)?
- *
- * The complexity is that either integer or fraction must be present and the
- * fraction is permitted to have no digits only if the integer is present.
- *
- * NOTE: The dangling E problem.
- * There is a PNG valid floating point number in the following:
- *
- * PNG floating point numbers are not greedy.
- *
- * Working this out requires *TWO* character lookahead (because of the
- * sign), the parser does not do this - it will fail at the 'r' - this
- * doesn't matter for PNG sCAL chunk values, but it requires more care
- * if the value were ever to be embedded in something more complex. Use
- * ANSI-C strtod if you need the lookahead.
- */
-/* State table for the parser. */
-#define PNG_FP_INTEGER 0 /* before or in integer */
-#define PNG_FP_FRACTION 1 /* before or in fraction */
-#define PNG_FP_EXPONENT 2 /* before or in exponent */
-#define PNG_FP_STATE 3 /* mask for the above */
-#define PNG_FP_SAW_SIGN 4 /* Saw +/- in current state */
-#define PNG_FP_SAW_DIGIT 8 /* Saw a digit in current state */
-#define PNG_FP_SAW_DOT 16 /* Saw a dot in current state */
-#define PNG_FP_SAW_E 32 /* Saw an E (or e) in current state */
-#define PNG_FP_SAW_ANY 60 /* Saw any of the above 4 */
-
-/* These three values don't affect the parser. They are set but not used.
- */
-#define PNG_FP_WAS_VALID 64 /* Preceding substring is a valid fp number */
-#define PNG_FP_NEGATIVE 128 /* A negative number, including "-0" */
-#define PNG_FP_NONZERO 256 /* A non-zero value */
-#define PNG_FP_STICKY 448 /* The above three flags */
-
-/* This is available for the caller to store in 'state' if required. Do not
- * call the parser after setting it (the parser sometimes clears it.)
- */
-#define PNG_FP_INVALID 512 /* Available for callers as a distinct value */
-
-/* Result codes for the parser (boolean - true meants ok, false means
- * not ok yet.)
- */
-#define PNG_FP_MAYBE 0 /* The number may be valid in the future */
-#define PNG_FP_OK 1 /* The number is valid */
-
-/* Tests on the sticky non-zero and negative flags. To pass these checks
- * the state must also indicate that the whole number is valid - this is
- * achieved by testing PNG_FP_SAW_DIGIT (see the implementation for why this
- * is equivalent to PNG_FP_OK above.)
- */
-#define PNG_FP_NZ_MASK (PNG_FP_SAW_DIGIT | PNG_FP_NEGATIVE | PNG_FP_NONZERO)
- /* NZ_MASK: the string is valid and a non-zero negative value */
-#define PNG_FP_Z_MASK (PNG_FP_SAW_DIGIT | PNG_FP_NONZERO)
- /* Z MASK: the string is valid and a non-zero value. */
- /* PNG_FP_SAW_DIGIT: the string is valid. */
-#define PNG_FP_IS_ZERO(state) (((state) & PNG_FP_Z_MASK) == PNG_FP_SAW_DIGIT)
-#define PNG_FP_IS_POSITIVE(state) (((state) & PNG_FP_NZ_MASK) == PNG_FP_Z_MASK)
-#define PNG_FP_IS_NEGATIVE(state) (((state) & PNG_FP_NZ_MASK) == PNG_FP_NZ_MASK)
-
-/* The actual parser. This can be called repeatedly. It updates
- * the index into the string and the state variable (which must
- * be initialized to 0). It returns a result code, as above. There
- * is no point calling the parser any more if it fails to advance to
- * the end of the string - it is stuck on an invalid character (or
- * terminated by '\0').
- *
- * Note that the pointer will consume an E or even an E+ and then leave
- * a 'maybe' state even though a preceding integer.fraction is valid.
- * The PNG_FP_WAS_VALID flag indicates that a preceding substring was
- * a valid number. It's possible to recover from this by calling
- * the parser again (from the start, with state 0) but with a string
- * that omits the last character (i.e. set the size to the index of
- * the problem character.) This has not been tested within libpng.
- */
-PNG_INTERNAL_FUNCTION(int,png_check_fp_number,(png_const_charp string,
- png_size_t size, int *statep, png_size_tp whereami),PNG_EMPTY);
-
-/* This is the same but it checks a complete string and returns true
- * only if it just contains a floating point number. As of 1.5.4 this
- * function also returns the state at the end of parsing the number if
- * it was valid (otherwise it returns 0.) This can be used for testing
- * for negative or zero values using the sticky flag.
- */
-PNG_INTERNAL_FUNCTION(int,png_check_fp_string,(png_const_charp string,
- png_size_t size),PNG_EMPTY);
-#endif /* pCAL || sCAL */
-
-#if defined(PNG_READ_GAMMA_SUPPORTED) ||\
- defined(PNG_INCH_CONVERSIONS_SUPPORTED) || defined(PNG_READ_pHYs_SUPPORTED)
-/* Added at libpng version 1.5.0 */
-/* This is a utility to provide a*times/div (rounded) and indicate
- * if there is an overflow. The result is a boolean - false (0)
- * for overflow, true (1) if no overflow, in which case *res
- * holds the result.
- */
-PNG_INTERNAL_FUNCTION(int,png_muldiv,(png_fixed_point_p res, png_fixed_point a,
- png_int_32 multiplied_by, png_int_32 divided_by),PNG_EMPTY);
-#endif
-
-#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_INCH_CONVERSIONS_SUPPORTED)
-/* Same deal, but issue a warning on overflow and return 0. */
-PNG_INTERNAL_FUNCTION(png_fixed_point,png_muldiv_warn,
- (png_const_structrp png_ptr, png_fixed_point a, png_int_32 multiplied_by,
- png_int_32 divided_by),PNG_EMPTY);
-#endif
-
-#ifdef PNG_GAMMA_SUPPORTED
-/* Calculate a reciprocal - used for gamma values. This returns
- * 0 if the argument is 0 in order to maintain an undefined value;
- * there are no warnings.
- */
-PNG_INTERNAL_FUNCTION(png_fixed_point,png_reciprocal,(png_fixed_point a),
- PNG_EMPTY);
-
-#ifdef PNG_READ_GAMMA_SUPPORTED
-/* The same but gives a reciprocal of the product of two fixed point
- * values. Accuracy is suitable for gamma calculations but this is
- * not exact - use png_muldiv for that. Only required at present on read.
- */
-PNG_INTERNAL_FUNCTION(png_fixed_point,png_reciprocal2,(png_fixed_point a,
- png_fixed_point b),PNG_EMPTY);
-#endif
-
-/* Return true if the gamma value is significantly different from 1.0 */
-PNG_INTERNAL_FUNCTION(int,png_gamma_significant,(png_fixed_point gamma_value),
- PNG_EMPTY);
-#endif
-
-#ifdef PNG_READ_GAMMA_SUPPORTED
-/* Internal fixed point gamma correction. These APIs are called as
- * required to convert single values - they don't need to be fast,
- * they are not used when processing image pixel values.
- *
- * While the input is an 'unsigned' value it must actually be the
- * correct bit value - 0..255 or 0..65535 as required.
- */
-PNG_INTERNAL_FUNCTION(png_uint_16,png_gamma_correct,(png_structrp png_ptr,
- unsigned int value, png_fixed_point gamma_value),PNG_EMPTY);
-PNG_INTERNAL_FUNCTION(png_uint_16,png_gamma_16bit_correct,(unsigned int value,
- png_fixed_point gamma_value),PNG_EMPTY);
-PNG_INTERNAL_FUNCTION(png_byte,png_gamma_8bit_correct,(unsigned int value,
- png_fixed_point gamma_value),PNG_EMPTY);
-PNG_INTERNAL_FUNCTION(void,png_destroy_gamma_table,(png_structrp png_ptr),
- PNG_EMPTY);
-PNG_INTERNAL_FUNCTION(void,png_build_gamma_table,(png_structrp png_ptr,
- int bit_depth),PNG_EMPTY);
-#endif
-
-/* SIMPLIFIED READ/WRITE SUPPORT */
-#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) ||\
- defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
-/* The internal structure that png_image::opaque points to. */
-typedef struct png_control
-{
- png_structp png_ptr;
- png_infop info_ptr;
- png_voidp error_buf; /* Always a jmp_buf at present. */
-
- png_const_bytep memory; /* Memory buffer. */
- png_size_t size; /* Size of the memory buffer. */
-
- unsigned int for_write :1; /* Otherwise it is a read structure */
- unsigned int owned_file :1; /* We own the file in io_ptr */
-} png_control;
-
-/* Return the pointer to the jmp_buf from a png_control: necessary because C
- * does not reveal the type of the elements of jmp_buf.
- */
-#ifdef __cplusplus
-# define png_control_jmp_buf(pc) (((jmp_buf*)((pc)->error_buf))[0])
-#else
-# define png_control_jmp_buf(pc) ((pc)->error_buf)
-#endif
-
-/* Utility to safely execute a piece of libpng code catching and logging any
- * errors that might occur. Returns true on success, false on failure (either
- * of the function or as a result of a png_error.)
- */
-PNG_INTERNAL_FUNCTION(void,png_safe_error,(png_structp png_ptr,
- png_const_charp error_message),PNG_NORETURN);
-
-#ifdef PNG_WARNINGS_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_safe_warning,(png_structp png_ptr,
- png_const_charp warning_message),PNG_EMPTY);
-#else
-# define png_safe_warning 0/*dummy argument*/
-#endif
-
-PNG_INTERNAL_FUNCTION(int,png_safe_execute,(png_imagep image,
- int (*function)(png_voidp), png_voidp arg),PNG_EMPTY);
-
-/* Utility to log an error; this also cleans up the png_image; the function
- * always returns 0 (false).
- */
-PNG_INTERNAL_FUNCTION(int,png_image_error,(png_imagep image,
- png_const_charp error_message),PNG_EMPTY);
-
-#ifndef PNG_SIMPLIFIED_READ_SUPPORTED
-/* png_image_free is used by the write code but not exported */
-PNG_INTERNAL_FUNCTION(void, png_image_free, (png_imagep image), PNG_EMPTY);
-#endif /* !SIMPLIFIED_READ */
-
-#endif /* SIMPLIFIED READ/WRITE */
-
-/* These are initialization functions for hardware specific PNG filter
- * optimizations; list these here then select the appropriate one at compile
- * time using the macro PNG_FILTER_OPTIMIZATIONS. If the macro is not defined
- * the generic code is used.
- */
-#ifdef PNG_FILTER_OPTIMIZATIONS
-PNG_INTERNAL_FUNCTION(void, PNG_FILTER_OPTIMIZATIONS, (png_structp png_ptr,
- unsigned int bpp), PNG_EMPTY);
- /* Just declare the optimization that will be used */
-#else
- /* List *all* the possible optimizations here - this branch is required if
- * the builder of libpng passes the definition of PNG_FILTER_OPTIMIZATIONS in
- * CFLAGS in place of CPPFLAGS *and* uses symbol prefixing.
- */
-PNG_INTERNAL_FUNCTION(void, png_init_filter_functions_neon,
- (png_structp png_ptr, unsigned int bpp), PNG_EMPTY);
-#endif
-
-/* Maintainer: Put new private prototypes here ^ */
-
-#include "pngdebug.h"
-
-#ifdef __cplusplus
-}
-#endif
-
-#endif /* PNG_VERSION_INFO_ONLY */
-#endif /* PNGPRIV_H */
+
+/* pngpriv.h - private declarations for use inside libpng
+ *
+ * Last changed in libpng 1.6.18 [July 23, 2015]
+ * Copyright (c) 1998-2015 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+
+/* The symbols declared in this file (including the functions declared
+ * as extern) are PRIVATE. They are not part of the libpng public
+ * interface, and are not recommended for use by regular applications.
+ * Some of them may become public in the future; others may stay private,
+ * change in an incompatible way, or even disappear.
+ * Although the libpng users are not forbidden to include this header,
+ * they should be well aware of the issues that may arise from doing so.
+ */
+
+#ifndef PNGPRIV_H
+#define PNGPRIV_H
+
+/* Feature Test Macros. The following are defined here to ensure that correctly
+ * implemented libraries reveal the APIs libpng needs to build and hide those
+ * that are not needed and potentially damaging to the compilation.
+ *
+ * Feature Test Macros must be defined before any system header is included (see
+ * POSIX 1003.1 2.8.2 "POSIX Symbols."
+ *
+ * These macros only have an effect if the operating system supports either
+ * POSIX 1003.1 or C99, or both. On other operating systems (particularly
+ * Windows/Visual Studio) there is no effect; the OS specific tests below are
+ * still required (as of 2011-05-02.)
+ */
+#define _POSIX_SOURCE 1 /* Just the POSIX 1003.1 and C89 APIs */
+
+#ifndef PNG_VERSION_INFO_ONLY
+/* Standard library headers not required by png.h: */
+# include <stdlib.h>
+# include <string.h>
+#endif
+
+#define PNGLIB_BUILD /*libpng is being built, not used*/
+
+/* If HAVE_CONFIG_H is defined during the build then the build system must
+ * provide an appropriate "config.h" file on the include path. The header file
+ * must provide definitions as required below (search for "HAVE_CONFIG_H");
+ * see configure.ac for more details of the requirements. The macro
+ * "PNG_NO_CONFIG_H" is provided for maintainers to test for dependencies on
+ * 'configure'; define this macro to prevent the configure build including the
+ * configure generated config.h. Libpng is expected to compile without *any*
+ * special build system support on a reasonably ANSI-C compliant system.
+ */
+#if defined(HAVE_CONFIG_H) && !defined(PNG_NO_CONFIG_H)
+# include <config.h>
+
+ /* Pick up the definition of 'restrict' from config.h if it was read: */
+# define PNG_RESTRICT restrict
+#endif
+
+/* To support symbol prefixing it is necessary to know *before* including png.h
+ * whether the fixed point (and maybe other) APIs are exported, because if they
+ * are not internal definitions may be required. This is handled below just
+ * before png.h is included, but load the configuration now if it is available.
+ */
+#ifndef PNGLCONF_H
+# include "pnglibconf.h"
+#endif
+
+/* Local renames may change non-exported API functions from png.h */
+#if defined(PNG_PREFIX) && !defined(PNGPREFIX_H)
+# include "pngprefix.h"
+#endif
+
+#ifdef PNG_USER_CONFIG
+# include "pngusr.h"
+ /* These should have been defined in pngusr.h */
+# ifndef PNG_USER_PRIVATEBUILD
+# define PNG_USER_PRIVATEBUILD "Custom libpng build"
+# endif
+# ifndef PNG_USER_DLLFNAME_POSTFIX
+# define PNG_USER_DLLFNAME_POSTFIX "Cb"
+# endif
+#endif
+
+/* Compile time options.
+ * =====================
+ * In a multi-arch build the compiler may compile the code several times for the
+ * same object module, producing different binaries for different architectures.
+ * When this happens configure-time setting of the target host options cannot be
+ * done and this interferes with the handling of the ARM NEON optimizations, and
+ * possibly other similar optimizations. Put additional tests here; in general
+ * this is needed when the same option can be changed at both compile time and
+ * run time depending on the target OS (i.e. iOS vs Android.)
+ *
+ * NOTE: symbol prefixing does not pass $(CFLAGS) to the preprocessor, because
+ * this is not possible with certain compilers (Oracle SUN OS CC), as a result
+ * it is necessary to ensure that all extern functions that *might* be used
+ * regardless of $(CFLAGS) get declared in this file. The test on __ARM_NEON__
+ * below is one example of this behavior because it is controlled by the
+ * presence or not of -mfpu=neon on the GCC command line, it is possible to do
+ * this in $(CC), e.g. "CC=gcc -mfpu=neon", but people who build libpng rarely
+ * do this.
+ */
+#ifndef PNG_ARM_NEON_OPT
+ /* ARM NEON optimizations are being controlled by the compiler settings,
+ * typically the target FPU. If the FPU has been set to NEON (-mfpu=neon
+ * with GCC) then the compiler will define __ARM_NEON__ and we can rely
+ * unconditionally on NEON instructions not crashing, otherwise we must
+ * disable use of NEON instructions.
+ *
+ * NOTE: at present these optimizations depend on 'ALIGNED_MEMORY', so they
+ * can only be turned on automatically if that is supported too. If
+ * PNG_ARM_NEON_OPT is set in CPPFLAGS (to >0) then arm/arm_init.c will fail
+ * to compile with an appropriate #error if ALIGNED_MEMORY has been turned
+ * off.
+ *
+ * Note that gcc-4.9 defines __ARM_NEON instead of the deprecated
+ * __ARM_NEON__, so we check both variants.
+ *
+ * To disable ARM_NEON optimizations entirely, and skip compiling the
+ * associated assembler code, pass --enable-arm-neon=no to configure
+ * or put -DPNG_ARM_NEON_OPT=0 in CPPFLAGS.
+ */
+# if (defined(__ARM_NEON__) || defined(__ARM_NEON)) && \
+ defined(PNG_ALIGNED_MEMORY_SUPPORTED)
+# define PNG_ARM_NEON_OPT 0
+# else
+# define PNG_ARM_NEON_OPT 0
+# endif
+#endif
+
+#if PNG_ARM_NEON_OPT > 0
+ /* NEON optimizations are to be at least considered by libpng, so enable the
+ * callbacks to do this.
+ */
+# define PNG_FILTER_OPTIMIZATIONS png_init_filter_functions_neon
+
+ /* By default the 'intrinsics' code in arm/filter_neon_intrinsics.c is used
+ * if possible - if __ARM_NEON__ is set and the compiler version is not known
+ * to be broken. This is controlled by PNG_ARM_NEON_IMPLEMENTATION which can
+ * be:
+ *
+ * 1 The intrinsics code (the default with __ARM_NEON__)
+ * 2 The hand coded assembler (the default without __ARM_NEON__)
+ *
+ * It is possible to set PNG_ARM_NEON_IMPLEMENTATION in CPPFLAGS, however
+ * this is *NOT* supported and may cease to work even after a minor revision
+ * to libpng. It *is* valid to do this for testing purposes, e.g. speed
+ * testing or a new compiler, but the results should be communicated to the
+ * libpng implementation list for incorporation in the next minor release.
+ */
+# ifndef PNG_ARM_NEON_IMPLEMENTATION
+# if defined(__ARM_NEON__) || defined(__ARM_NEON)
+# if defined(__clang__)
+ /* At present it is unknown by the libpng developers which versions
+ * of clang support the intrinsics, however some or perhaps all
+ * versions do not work with the assembler so this may be
+ * irrelevant, so just use the default (do nothing here.)
+ */
+# elif defined(__GNUC__)
+ /* GCC 4.5.4 NEON support is known to be broken. 4.6.3 is known to
+ * work, so if this *is* GCC, or G++, look for a version >4.5
+ */
+# if __GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 6)
+# define PNG_ARM_NEON_IMPLEMENTATION 2
+# endif /* no GNUC support */
+# endif /* __GNUC__ */
+# else /* !defined __ARM_NEON__ */
+ /* The 'intrinsics' code simply won't compile without this -mfpu=neon:
+ */
+# define PNG_ARM_NEON_IMPLEMENTATION 2
+# endif /* __ARM_NEON__ */
+# endif /* !PNG_ARM_NEON_IMPLEMENTATION */
+
+# ifndef PNG_ARM_NEON_IMPLEMENTATION
+ /* Use the intrinsics code by default. */
+# define PNG_ARM_NEON_IMPLEMENTATION 1
+# endif
+#endif /* PNG_ARM_NEON_OPT > 0 */
+
+/* Is this a build of a DLL where compilation of the object modules requires
+ * different preprocessor settings to those required for a simple library? If
+ * so PNG_BUILD_DLL must be set.
+ *
+ * If libpng is used inside a DLL but that DLL does not export the libpng APIs
+ * PNG_BUILD_DLL must not be set. To avoid the code below kicking in build a
+ * static library of libpng then link the DLL against that.
+ */
+#ifndef PNG_BUILD_DLL
+# ifdef DLL_EXPORT
+ /* This is set by libtool when files are compiled for a DLL; libtool
+ * always compiles twice, even on systems where it isn't necessary. Set
+ * PNG_BUILD_DLL in case it is necessary:
+ */
+# define PNG_BUILD_DLL
+# else
+# ifdef _WINDLL
+ /* This is set by the Microsoft Visual Studio IDE in projects that
+ * build a DLL. It can't easily be removed from those projects (it
+ * isn't visible in the Visual Studio UI) so it is a fairly reliable
+ * indication that PNG_IMPEXP needs to be set to the DLL export
+ * attributes.
+ */
+# define PNG_BUILD_DLL
+# else
+# ifdef __DLL__
+ /* This is set by the Borland C system when compiling for a DLL
+ * (as above.)
+ */
+# define PNG_BUILD_DLL
+# else
+ /* Add additional compiler cases here. */
+# endif
+# endif
+# endif
+#endif /* Setting PNG_BUILD_DLL if required */
+
+/* See pngconf.h for more details: the builder of the library may set this on
+ * the command line to the right thing for the specific compilation system or it
+ * may be automagically set above (at present we know of no system where it does
+ * need to be set on the command line.)
+ *
+ * PNG_IMPEXP must be set here when building the library to prevent pngconf.h
+ * setting it to the "import" setting for a DLL build.
+ */
+#ifndef PNG_IMPEXP
+# ifdef PNG_BUILD_DLL
+# define PNG_IMPEXP PNG_DLL_EXPORT
+# else
+ /* Not building a DLL, or the DLL doesn't require specific export
+ * definitions.
+ */
+# define PNG_IMPEXP
+# endif
+#endif
+
+/* No warnings for private or deprecated functions in the build: */
+#ifndef PNG_DEPRECATED
+# define PNG_DEPRECATED
+#endif
+#ifndef PNG_PRIVATE
+# define PNG_PRIVATE
+#endif
+
+/* Symbol preprocessing support.
+ *
+ * To enable listing global, but internal, symbols the following macros should
+ * always be used to declare an extern data or function object in this file.
+ */
+#ifndef PNG_INTERNAL_DATA
+# define PNG_INTERNAL_DATA(type, name, array) PNG_LINKAGE_DATA type name array
+#endif
+
+#ifndef PNG_INTERNAL_FUNCTION
+# define PNG_INTERNAL_FUNCTION(type, name, args, attributes)\
+ PNG_LINKAGE_FUNCTION PNG_FUNCTION(type, name, args, PNG_EMPTY attributes)
+#endif
+
+#ifndef PNG_INTERNAL_CALLBACK
+# define PNG_INTERNAL_CALLBACK(type, name, args, attributes)\
+ PNG_LINKAGE_CALLBACK PNG_FUNCTION(type, (PNGCBAPI name), args,\
+ PNG_EMPTY attributes)
+#endif
+
+/* If floating or fixed point APIs are disabled they may still be compiled
+ * internally. To handle this make sure they are declared as the appropriate
+ * internal extern function (otherwise the symbol prefixing stuff won't work and
+ * the functions will be used without definitions.)
+ *
+ * NOTE: although all the API functions are declared here they are not all
+ * actually built! Because the declarations are still made it is necessary to
+ * fake out types that they depend on.
+ */
+#ifndef PNG_FP_EXPORT
+# ifndef PNG_FLOATING_POINT_SUPPORTED
+# define PNG_FP_EXPORT(ordinal, type, name, args)\
+ PNG_INTERNAL_FUNCTION(type, name, args, PNG_EMPTY);
+# ifndef PNG_VERSION_INFO_ONLY
+ typedef struct png_incomplete png_double;
+ typedef png_double* png_doublep;
+ typedef const png_double* png_const_doublep;
+ typedef png_double** png_doublepp;
+# endif
+# endif
+#endif
+#ifndef PNG_FIXED_EXPORT
+# ifndef PNG_FIXED_POINT_SUPPORTED
+# define PNG_FIXED_EXPORT(ordinal, type, name, args)\
+ PNG_INTERNAL_FUNCTION(type, name, args, PNG_EMPTY);
+# endif
+#endif
+
+#include "png.h"
+
+/* pngconf.h does not set PNG_DLL_EXPORT unless it is required, so: */
+#ifndef PNG_DLL_EXPORT
+# define PNG_DLL_EXPORT
+#endif
+
+/* This is a global switch to set the compilation for an installed system
+ * (a release build). It can be set for testing debug builds to ensure that
+ * they will compile when the build type is switched to RC or STABLE, the
+ * default is just to use PNG_LIBPNG_BUILD_BASE_TYPE. Set this in CPPFLAGS
+ * with either:
+ *
+ * -DPNG_RELEASE_BUILD Turns on the release compile path
+ * -DPNG_RELEASE_BUILD=0 Turns it off
+ * or in your pngusr.h with
+ * #define PNG_RELEASE_BUILD=1 Turns on the release compile path
+ * #define PNG_RELEASE_BUILD=0 Turns it off
+ */
+#ifndef PNG_RELEASE_BUILD
+# define PNG_RELEASE_BUILD (PNG_LIBPNG_BUILD_BASE_TYPE >= PNG_LIBPNG_BUILD_RC)
+#endif
+
+/* SECURITY and SAFETY:
+ *
+ * libpng is built with support for internal limits on image dimensions and
+ * memory usage. These are documented in scripts/pnglibconf.dfa of the
+ * source and recorded in the machine generated header file pnglibconf.h.
+ */
+
+/* If you are running on a machine where you cannot allocate more
+ * than 64K of memory at once, uncomment this. While libpng will not
+ * normally need that much memory in a chunk (unless you load up a very
+ * large file), zlib needs to know how big of a chunk it can use, and
+ * libpng thus makes sure to check any memory allocation to verify it
+ * will fit into memory.
+ *
+ * zlib provides 'MAXSEG_64K' which, if defined, indicates the
+ * same limit and pngconf.h (already included) sets the limit
+ * if certain operating systems are detected.
+ */
+#if defined(MAXSEG_64K) && !defined(PNG_MAX_MALLOC_64K)
+# define PNG_MAX_MALLOC_64K
+#endif
+
+#ifndef PNG_UNUSED
+/* Unused formal parameter warnings are silenced using the following macro
+ * which is expected to have no bad effects on performance (optimizing
+ * compilers will probably remove it entirely). Note that if you replace
+ * it with something other than whitespace, you must include the terminating
+ * semicolon.
+ */
+# define PNG_UNUSED(param) (void)param;
+#endif
+
+/* Just a little check that someone hasn't tried to define something
+ * contradictory.
+ */
+#if (PNG_ZBUF_SIZE > 65536L) && defined(PNG_MAX_MALLOC_64K)
+# undef PNG_ZBUF_SIZE
+# define PNG_ZBUF_SIZE 65536L
+#endif
+
+/* If warnings or errors are turned off the code is disabled or redirected here.
+ * From 1.5.4 functions have been added to allow very limited formatting of
+ * error and warning messages - this code will also be disabled here.
+ */
+#ifdef PNG_WARNINGS_SUPPORTED
+# define PNG_WARNING_PARAMETERS(p) png_warning_parameters p;
+#else
+# define png_warning_parameter(p,number,string) ((void)0)
+# define png_warning_parameter_unsigned(p,number,format,value) ((void)0)
+# define png_warning_parameter_signed(p,number,format,value) ((void)0)
+# define png_formatted_warning(pp,p,message) ((void)(pp))
+# define PNG_WARNING_PARAMETERS(p)
+#endif
+#ifndef PNG_ERROR_TEXT_SUPPORTED
+# define png_fixed_error(s1,s2) png_err(s1)
+#endif
+
+/* C allows up-casts from (void*) to any pointer and (const void*) to any
+ * pointer to a const object. C++ regards this as a type error and requires an
+ * explicit, static, cast and provides the static_cast<> rune to ensure that
+ * const is not cast away.
+ */
+#ifdef __cplusplus
+# define png_voidcast(type, value) static_cast<type>(value)
+# define png_constcast(type, value) const_cast<type>(value)
+# define png_aligncast(type, value) \
+ static_cast<type>(static_cast<void*>(value))
+# define png_aligncastconst(type, value) \
+ static_cast<type>(static_cast<const void*>(value))
+#else
+# define png_voidcast(type, value) (value)
+# define png_constcast(type, value) ((type)(value))
+# define png_aligncast(type, value) ((void*)(value))
+# define png_aligncastconst(type, value) ((const void*)(value))
+#endif /* __cplusplus */
+
+/* Some fixed point APIs are still required even if not exported because
+ * they get used by the corresponding floating point APIs. This magic
+ * deals with this:
+ */
+#ifdef PNG_FIXED_POINT_SUPPORTED
+# define PNGFAPI PNGAPI
+#else
+# define PNGFAPI /* PRIVATE */
+#endif
+
+#ifndef PNG_VERSION_INFO_ONLY
+/* Other defines specific to compilers can go here. Try to keep
+ * them inside an appropriate ifdef/endif pair for portability.
+ */
+#if defined(PNG_FLOATING_POINT_SUPPORTED) ||\
+ defined(PNG_FLOATING_ARITHMETIC_SUPPORTED)
+ /* png.c requires the following ANSI-C constants if the conversion of
+ * floating point to ASCII is implemented therein:
+ *
+ * DBL_DIG Maximum number of decimal digits (can be set to any constant)
+ * DBL_MIN Smallest normalized fp number (can be set to an arbitrary value)
+ * DBL_MAX Maximum floating point number (can be set to an arbitrary value)
+ */
+# include <float.h>
+
+# if (defined(__MWERKS__) && defined(macintosh)) || defined(applec) || \
+ defined(THINK_C) || defined(__SC__) || defined(TARGET_OS_MAC)
+ /* We need to check that <math.h> hasn't already been included earlier
+ * as it seems it doesn't agree with <fp.h>, yet we should really use
+ * <fp.h> if possible.
+ */
+# if !defined(__MATH_H__) && !defined(__MATH_H) && !defined(__cmath__)
+# include <fp.h>
+# endif
+# else
+# include <math.h>
+# endif
+# if defined(_AMIGA) && defined(__SASC) && defined(_M68881)
+ /* Amiga SAS/C: We must include builtin FPU functions when compiling using
+ * MATH=68881
+ */
+# include <m68881.h>
+# endif
+#endif
+
+/* This provides the non-ANSI (far) memory allocation routines. */
+#if defined(__TURBOC__) && defined(__MSDOS__)
+# include <mem.h>
+# include <alloc.h>
+#endif
+
+#if defined(WIN32) || defined(_Windows) || defined(_WINDOWS) || \
+ defined(_WIN32) || defined(__WIN32__)
+# include <windows.h> /* defines _WINDOWS_ macro */
+#endif
+#endif /* PNG_VERSION_INFO_ONLY */
+
+/* Moved here around 1.5.0beta36 from pngconf.h */
+/* Users may want to use these so they are not private. Any library
+ * functions that are passed far data must be model-independent.
+ */
+
+/* Memory model/platform independent fns */
+#ifndef PNG_ABORT
+# ifdef _WINDOWS_
+# define PNG_ABORT() ExitProcess(0)
+# else
+# define PNG_ABORT() abort()
+# endif
+#endif
+
+/* These macros may need to be architecture dependent. */
+#define PNG_ALIGN_NONE 0 /* do not use data alignment */
+#define PNG_ALIGN_ALWAYS 1 /* assume unaligned accesses are OK */
+#ifdef offsetof
+# define PNG_ALIGN_OFFSET 2 /* use offsetof to determine alignment */
+#else
+# define PNG_ALIGN_OFFSET -1 /* prevent the use of this */
+#endif
+#define PNG_ALIGN_SIZE 3 /* use sizeof to determine alignment */
+
+#ifndef PNG_ALIGN_TYPE
+ /* Default to using aligned access optimizations and requiring alignment to a
+ * multiple of the data type size. Override in a compiler specific fashion
+ * if necessary by inserting tests here:
+ */
+# define PNG_ALIGN_TYPE PNG_ALIGN_SIZE
+#endif
+
+#if PNG_ALIGN_TYPE == PNG_ALIGN_SIZE
+ /* This is used because in some compiler implementations non-aligned
+ * structure members are supported, so the offsetof approach below fails.
+ * Set PNG_ALIGN_SIZE=0 for compiler combinations where unaligned access
+ * is good for performance. Do not do this unless you have tested the result
+ * and understand it.
+ */
+# define png_alignof(type) (sizeof (type))
+#else
+# if PNG_ALIGN_TYPE == PNG_ALIGN_OFFSET
+# define png_alignof(type) offsetof(struct{char c; type t;}, t)
+# else
+# if PNG_ALIGN_TYPE == PNG_ALIGN_ALWAYS
+# define png_alignof(type) (1)
+# endif
+ /* Else leave png_alignof undefined to prevent use thereof */
+# endif
+#endif
+
+/* This implicitly assumes alignment is always to a power of 2. */
+#ifdef png_alignof
+# define png_isaligned(ptr, type)\
+ ((((const char*)ptr-(const char*)0) & (png_alignof(type)-1)) == 0)
+#else
+# define png_isaligned(ptr, type) 0
+#endif
+
+/* End of memory model/platform independent support */
+/* End of 1.5.0beta36 move from pngconf.h */
+
+/* CONSTANTS and UTILITY MACROS
+ * These are used internally by libpng and not exposed in the API
+ */
+
+/* Various modes of operation. Note that after an init, mode is set to
+ * zero automatically when the structure is created. Three of these
+ * are defined in png.h because they need to be visible to applications
+ * that call png_set_unknown_chunk().
+ */
+/* #define PNG_HAVE_IHDR 0x01 (defined in png.h) */
+/* #define PNG_HAVE_PLTE 0x02 (defined in png.h) */
+#define PNG_HAVE_IDAT 0x04
+/* #define PNG_AFTER_IDAT 0x08 (defined in png.h) */
+#define PNG_HAVE_IEND 0x10
+ /* 0x20 (unused) */
+ /* 0x40 (unused) */
+ /* 0x80 (unused) */
+#define PNG_HAVE_CHUNK_HEADER 0x100
+#define PNG_WROTE_tIME 0x200
+#define PNG_WROTE_INFO_BEFORE_PLTE 0x400
+#define PNG_BACKGROUND_IS_GRAY 0x800
+#define PNG_HAVE_PNG_SIGNATURE 0x1000
+#define PNG_HAVE_CHUNK_AFTER_IDAT 0x2000 /* Have another chunk after IDAT */
+ /* 0x4000 (unused) */
+#define PNG_IS_READ_STRUCT 0x8000 /* Else is a write struct */
+
+/* Flags for the transformations the PNG library does on the image data */
+#define PNG_BGR 0x0001
+#define PNG_INTERLACE 0x0002
+#define PNG_PACK 0x0004
+#define PNG_SHIFT 0x0008
+#define PNG_SWAP_BYTES 0x0010
+#define PNG_INVERT_MONO 0x0020
+#define PNG_QUANTIZE 0x0040
+#define PNG_COMPOSE 0x0080 /* Was PNG_BACKGROUND */
+#define PNG_BACKGROUND_EXPAND 0x0100
+#define PNG_EXPAND_16 0x0200 /* Added to libpng 1.5.2 */
+#define PNG_16_TO_8 0x0400 /* Becomes 'chop' in 1.5.4 */
+#define PNG_RGBA 0x0800
+#define PNG_EXPAND 0x1000
+#define PNG_GAMMA 0x2000
+#define PNG_GRAY_TO_RGB 0x4000
+#define PNG_FILLER 0x8000
+#define PNG_PACKSWAP 0x10000
+#define PNG_SWAP_ALPHA 0x20000
+#define PNG_STRIP_ALPHA 0x40000
+#define PNG_INVERT_ALPHA 0x80000
+#define PNG_USER_TRANSFORM 0x100000
+#define PNG_RGB_TO_GRAY_ERR 0x200000
+#define PNG_RGB_TO_GRAY_WARN 0x400000
+#define PNG_RGB_TO_GRAY 0x600000 /* two bits, RGB_TO_GRAY_ERR|WARN */
+#define PNG_ENCODE_ALPHA 0x800000 /* Added to libpng-1.5.4 */
+#define PNG_ADD_ALPHA 0x1000000 /* Added to libpng-1.2.7 */
+#define PNG_EXPAND_tRNS 0x2000000 /* Added to libpng-1.2.9 */
+#define PNG_SCALE_16_TO_8 0x4000000 /* Added to libpng-1.5.4 */
+ /* 0x8000000 unused */
+ /* 0x10000000 unused */
+ /* 0x20000000 unused */
+ /* 0x40000000 unused */
+/* Flags for png_create_struct */
+#define PNG_STRUCT_PNG 0x0001
+#define PNG_STRUCT_INFO 0x0002
+
+/* Flags for the png_ptr->flags rather than declaring a byte for each one */
+#define PNG_FLAG_ZLIB_CUSTOM_STRATEGY 0x0001
+#define PNG_FLAG_ZSTREAM_INITIALIZED 0x0002 /* Added to libpng-1.6.0 */
+ /* 0x0004 unused */
+#define PNG_FLAG_ZSTREAM_ENDED 0x0008 /* Added to libpng-1.6.0 */
+ /* 0x0010 unused */
+ /* 0x0020 unused */
+#define PNG_FLAG_ROW_INIT 0x0040
+#define PNG_FLAG_FILLER_AFTER 0x0080
+#define PNG_FLAG_CRC_ANCILLARY_USE 0x0100
+#define PNG_FLAG_CRC_ANCILLARY_NOWARN 0x0200
+#define PNG_FLAG_CRC_CRITICAL_USE 0x0400
+#define PNG_FLAG_CRC_CRITICAL_IGNORE 0x0800
+#define PNG_FLAG_ASSUME_sRGB 0x1000 /* Added to libpng-1.5.4 */
+#define PNG_FLAG_OPTIMIZE_ALPHA 0x2000 /* Added to libpng-1.5.4 */
+#define PNG_FLAG_DETECT_UNINITIALIZED 0x4000 /* Added to libpng-1.5.4 */
+/* #define PNG_FLAG_KEEP_UNKNOWN_CHUNKS 0x8000 */
+/* #define PNG_FLAG_KEEP_UNSAFE_CHUNKS 0x10000 */
+#define PNG_FLAG_LIBRARY_MISMATCH 0x20000
+#define PNG_FLAG_STRIP_ERROR_NUMBERS 0x40000
+#define PNG_FLAG_STRIP_ERROR_TEXT 0x80000
+#define PNG_FLAG_BENIGN_ERRORS_WARN 0x100000 /* Added to libpng-1.4.0 */
+#define PNG_FLAG_APP_WARNINGS_WARN 0x200000 /* Added to libpng-1.6.0 */
+#define PNG_FLAG_APP_ERRORS_WARN 0x400000 /* Added to libpng-1.6.0 */
+ /* 0x800000 unused */
+ /* 0x1000000 unused */
+ /* 0x2000000 unused */
+ /* 0x4000000 unused */
+ /* 0x8000000 unused */
+ /* 0x10000000 unused */
+ /* 0x20000000 unused */
+ /* 0x40000000 unused */
+
+#define PNG_FLAG_CRC_ANCILLARY_MASK (PNG_FLAG_CRC_ANCILLARY_USE | \
+ PNG_FLAG_CRC_ANCILLARY_NOWARN)
+
+#define PNG_FLAG_CRC_CRITICAL_MASK (PNG_FLAG_CRC_CRITICAL_USE | \
+ PNG_FLAG_CRC_CRITICAL_IGNORE)
+
+#define PNG_FLAG_CRC_MASK (PNG_FLAG_CRC_ANCILLARY_MASK | \
+ PNG_FLAG_CRC_CRITICAL_MASK)
+
+/* Save typing and make code easier to understand */
+
+#define PNG_COLOR_DIST(c1, c2) (abs((int)((c1).red) - (int)((c2).red)) + \
+ abs((int)((c1).green) - (int)((c2).green)) + \
+ abs((int)((c1).blue) - (int)((c2).blue)))
+
+/* Added to libpng-1.6.0: scale a 16-bit value in the range 0..65535 to 0..255
+ * by dividing by 257 *with rounding*. This macro is exact for the given range.
+ * See the discourse in pngrtran.c png_do_scale_16_to_8. The values in the
+ * macro were established by experiment (modifying the added value). The macro
+ * has a second variant that takes a value already scaled by 255 and divides by
+ * 65535 - this has a maximum error of .502. Over the range 0..65535*65535 it
+ * only gives off-by-one errors and only for 0.5% (1 in 200) of the values.
+ */
+#define PNG_DIV65535(v24) (((v24) + 32895) >> 16)
+#define PNG_DIV257(v16) PNG_DIV65535((png_uint_32)(v16) * 255)
+
+/* Added to libpng-1.2.6 JB */
+#define PNG_ROWBYTES(pixel_bits, width) \
+ ((pixel_bits) >= 8 ? \
+ ((png_size_t)(width) * (((png_size_t)(pixel_bits)) >> 3)) : \
+ (( ((png_size_t)(width) * ((png_size_t)(pixel_bits))) + 7) >> 3) )
+
+/* PNG_OUT_OF_RANGE returns true if value is outside the range
+ * ideal-delta..ideal+delta. Each argument is evaluated twice.
+ * "ideal" and "delta" should be constants, normally simple
+ * integers, "value" a variable. Added to libpng-1.2.6 JB
+ */
+#define PNG_OUT_OF_RANGE(value, ideal, delta) \
+ ( (value) < (ideal)-(delta) || (value) > (ideal)+(delta) )
+
+/* Conversions between fixed and floating point, only defined if
+ * required (to make sure the code doesn't accidentally use float
+ * when it is supposedly disabled.)
+ */
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+/* The floating point conversion can't overflow, though it can and
+ * does lose accuracy relative to the original fixed point value.
+ * In practice this doesn't matter because png_fixed_point only
+ * stores numbers with very low precision. The png_ptr and s
+ * arguments are unused by default but are there in case error
+ * checking becomes a requirement.
+ */
+#define png_float(png_ptr, fixed, s) (.00001 * (fixed))
+
+/* The fixed point conversion performs range checking and evaluates
+ * its argument multiple times, so must be used with care. The
+ * range checking uses the PNG specification values for a signed
+ * 32-bit fixed point value except that the values are deliberately
+ * rounded-to-zero to an integral value - 21474 (21474.83 is roughly
+ * (2^31-1) * 100000). 's' is a string that describes the value being
+ * converted.
+ *
+ * NOTE: this macro will raise a png_error if the range check fails,
+ * therefore it is normally only appropriate to use this on values
+ * that come from API calls or other sources where an out of range
+ * error indicates a programming error, not a data error!
+ *
+ * NOTE: by default this is off - the macro is not used - because the
+ * function call saves a lot of code.
+ */
+#ifdef PNG_FIXED_POINT_MACRO_SUPPORTED
+#define png_fixed(png_ptr, fp, s) ((fp) <= 21474 && (fp) >= -21474 ?\
+ ((png_fixed_point)(100000 * (fp))) : (png_fixed_error(png_ptr, s),0))
+#endif
+/* else the corresponding function is defined below, inside the scope of the
+ * cplusplus test.
+ */
+#endif
+
+/* Constants for known chunk types. If you need to add a chunk, define the name
+ * here. For historical reasons these constants have the form png_<name>; i.e.
+ * the prefix is lower case. Please use decimal values as the parameters to
+ * match the ISO PNG specification and to avoid relying on the C locale
+ * interpretation of character values.
+ *
+ * Prior to 1.5.6 these constants were strings, as of 1.5.6 png_uint_32 values
+ * are computed and a new macro (PNG_STRING_FROM_CHUNK) added to allow a string
+ * to be generated if required.
+ *
+ * PNG_32b correctly produces a value shifted by up to 24 bits, even on
+ * architectures where (int) is only 16 bits.
+ */
+#define PNG_32b(b,s) ((png_uint_32)(b) << (s))
+#define PNG_U32(b1,b2,b3,b4) \
+ (PNG_32b(b1,24) | PNG_32b(b2,16) | PNG_32b(b3,8) | PNG_32b(b4,0))
+
+/* Constants for known chunk types.
+ *
+ * MAINTAINERS: If you need to add a chunk, define the name here.
+ * For historical reasons these constants have the form png_<name>; i.e.
+ * the prefix is lower case. Please use decimal values as the parameters to
+ * match the ISO PNG specification and to avoid relying on the C locale
+ * interpretation of character values. Please keep the list sorted.
+ *
+ * Notice that PNG_U32 is used to define a 32-bit value for the 4 byte chunk
+ * type. In fact the specification does not express chunk types this way,
+ * however using a 32-bit value means that the chunk type can be read from the
+ * stream using exactly the same code as used for a 32-bit unsigned value and
+ * can be examined far more efficiently (using one arithmetic compare).
+ *
+ * Prior to 1.5.6 the chunk type constants were expressed as C strings. The
+ * libpng API still uses strings for 'unknown' chunks and a macro,
+ * PNG_STRING_FROM_CHUNK, allows a string to be generated if required. Notice
+ * that for portable code numeric values must still be used; the string "IHDR"
+ * is not portable and neither is PNG_U32('I', 'H', 'D', 'R').
+ *
+ * In 1.7.0 the definitions will be made public in png.h to avoid having to
+ * duplicate the same definitions in application code.
+ */
+#define png_IDAT PNG_U32( 73, 68, 65, 84)
+#define png_IEND PNG_U32( 73, 69, 78, 68)
+#define png_IHDR PNG_U32( 73, 72, 68, 82)
+#define png_PLTE PNG_U32( 80, 76, 84, 69)
+#define png_bKGD PNG_U32( 98, 75, 71, 68)
+#define png_cHRM PNG_U32( 99, 72, 82, 77)
+#define png_fRAc PNG_U32(102, 82, 65, 99) /* registered, not defined */
+#define png_gAMA PNG_U32(103, 65, 77, 65)
+#define png_gIFg PNG_U32(103, 73, 70, 103)
+#define png_gIFt PNG_U32(103, 73, 70, 116) /* deprecated */
+#define png_gIFx PNG_U32(103, 73, 70, 120)
+#define png_hIST PNG_U32(104, 73, 83, 84)
+#define png_iCCP PNG_U32(105, 67, 67, 80)
+#define png_iTXt PNG_U32(105, 84, 88, 116)
+#define png_oFFs PNG_U32(111, 70, 70, 115)
+#define png_pCAL PNG_U32(112, 67, 65, 76)
+#define png_pHYs PNG_U32(112, 72, 89, 115)
+#define png_sBIT PNG_U32(115, 66, 73, 84)
+#define png_sCAL PNG_U32(115, 67, 65, 76)
+#define png_sPLT PNG_U32(115, 80, 76, 84)
+#define png_sRGB PNG_U32(115, 82, 71, 66)
+#define png_sTER PNG_U32(115, 84, 69, 82)
+#define png_tEXt PNG_U32(116, 69, 88, 116)
+#define png_tIME PNG_U32(116, 73, 77, 69)
+#define png_tRNS PNG_U32(116, 82, 78, 83)
+#define png_zTXt PNG_U32(122, 84, 88, 116)
+
+/* The following will work on (signed char*) strings, whereas the get_uint_32
+ * macro will fail on top-bit-set values because of the sign extension.
+ */
+#define PNG_CHUNK_FROM_STRING(s)\
+ PNG_U32(0xff & (s)[0], 0xff & (s)[1], 0xff & (s)[2], 0xff & (s)[3])
+
+/* This uses (char), not (png_byte) to avoid warnings on systems where (char) is
+ * signed and the argument is a (char[]) This macro will fail miserably on
+ * systems where (char) is more than 8 bits.
+ */
+#define PNG_STRING_FROM_CHUNK(s,c)\
+ (void)(((char*)(s))[0]=(char)(((c)>>24) & 0xff), \
+ ((char*)(s))[1]=(char)(((c)>>16) & 0xff),\
+ ((char*)(s))[2]=(char)(((c)>>8) & 0xff), \
+ ((char*)(s))[3]=(char)((c & 0xff)))
+
+/* Do the same but terminate with a null character. */
+#define PNG_CSTRING_FROM_CHUNK(s,c)\
+ (void)(PNG_STRING_FROM_CHUNK(s,c), ((char*)(s))[4] = 0)
+
+/* Test on flag values as defined in the spec (section 5.4): */
+#define PNG_CHUNK_ANCILLARY(c) (1 & ((c) >> 29))
+#define PNG_CHUNK_CRITICAL(c) (!PNG_CHUNK_ANCILLARY(c))
+#define PNG_CHUNK_PRIVATE(c) (1 & ((c) >> 21))
+#define PNG_CHUNK_RESERVED(c) (1 & ((c) >> 13))
+#define PNG_CHUNK_SAFE_TO_COPY(c) (1 & ((c) >> 5))
+
+/* Gamma values (new at libpng-1.5.4): */
+#define PNG_GAMMA_MAC_OLD 151724 /* Assume '1.8' is really 2.2/1.45! */
+#define PNG_GAMMA_MAC_INVERSE 65909
+#define PNG_GAMMA_sRGB_INVERSE 45455
+
+/* Almost everything below is C specific; the #defines above can be used in
+ * non-C code (so long as it is C-preprocessed) the rest of this stuff cannot.
+ */
+#ifndef PNG_VERSION_INFO_ONLY
+
+#include "pngstruct.h"
+#include "pnginfo.h"
+
+/* Validate the include paths - the include path used to generate pnglibconf.h
+ * must match that used in the build, or we must be using pnglibconf.h.prebuilt:
+ */
+#if PNG_ZLIB_VERNUM != 0 && PNG_ZLIB_VERNUM != ZLIB_VERNUM
+# error ZLIB_VERNUM != PNG_ZLIB_VERNUM \
+ "-I (include path) error: see the notes in pngpriv.h"
+ /* This means that when pnglibconf.h was built the copy of zlib.h that it
+ * used is not the same as the one being used here. Because the build of
+ * libpng makes decisions to use inflateInit2 and inflateReset2 based on the
+ * zlib version number and because this affects handling of certain broken
+ * PNG files the -I directives must match.
+ *
+ * The most likely explanation is that you passed a -I in CFLAGS. This will
+ * not work; all the preprocessor directories and in particular all the -I
+ * directives must be in CPPFLAGS.
+ */
+#endif
+
+/* This is used for 16-bit gamma tables -- only the top level pointers are
+ * const; this could be changed:
+ */
+typedef const png_uint_16p * png_const_uint_16pp;
+
+/* Added to libpng-1.5.7: sRGB conversion tables */
+#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) ||\
+ defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
+#ifdef PNG_SIMPLIFIED_READ_SUPPORTED
+PNG_INTERNAL_DATA(const png_uint_16, png_sRGB_table, [256]);
+ /* Convert from an sRGB encoded value 0..255 to a 16-bit linear value,
+ * 0..65535. This table gives the closest 16-bit answers (no errors).
+ */
+#endif
+
+PNG_INTERNAL_DATA(const png_uint_16, png_sRGB_base, [512]);
+PNG_INTERNAL_DATA(const png_byte, png_sRGB_delta, [512]);
+
+#define PNG_sRGB_FROM_LINEAR(linear) \
+ ((png_byte)(0xff & ((png_sRGB_base[(linear)>>15] \
+ + ((((linear) & 0x7fff)*png_sRGB_delta[(linear)>>15])>>12)) >> 8)))
+ /* Given a value 'linear' in the range 0..255*65535 calculate the 8-bit sRGB
+ * encoded value with maximum error 0.646365. Note that the input is not a
+ * 16-bit value; it has been multiplied by 255! */
+#endif /* SIMPLIFIED_READ/WRITE */
+
+
+/* Inhibit C++ name-mangling for libpng functions but not for system calls. */
+#ifdef __cplusplus
+extern "C" {
+#endif /* __cplusplus */
+
+/* Internal functions; these are not exported from a DLL however because they
+ * are used within several of the C source files they have to be C extern.
+ *
+ * All of these functions must be declared with PNG_INTERNAL_FUNCTION.
+ */
+
+/* Zlib support */
+#define PNG_UNEXPECTED_ZLIB_RETURN (-7)
+PNG_INTERNAL_FUNCTION(void, png_zstream_error,(png_structrp png_ptr, int ret),
+ PNG_EMPTY);
+ /* Used by the zlib handling functions to ensure that z_stream::msg is always
+ * set before they return.
+ */
+
+#ifdef PNG_WRITE_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_free_buffer_list,(png_structrp png_ptr,
+ png_compression_bufferp *list),PNG_EMPTY);
+ /* Free the buffer list used by the compressed write code. */
+#endif
+
+#if defined(PNG_FLOATING_POINT_SUPPORTED) && \
+ !defined(PNG_FIXED_POINT_MACRO_SUPPORTED) && \
+ (defined(PNG_gAMA_SUPPORTED) || defined(PNG_cHRM_SUPPORTED) || \
+ defined(PNG_sCAL_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) || \
+ defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)) || \
+ (defined(PNG_sCAL_SUPPORTED) && \
+ defined(PNG_FLOATING_ARITHMETIC_SUPPORTED))
+PNG_INTERNAL_FUNCTION(png_fixed_point,png_fixed,(png_const_structrp png_ptr,
+ double fp, png_const_charp text),PNG_EMPTY);
+#endif
+
+/* Check the user version string for compatibility, returns false if the version
+ * numbers aren't compatible.
+ */
+PNG_INTERNAL_FUNCTION(int,png_user_version_check,(png_structrp png_ptr,
+ png_const_charp user_png_ver),PNG_EMPTY);
+
+/* Internal base allocator - no messages, NULL on failure to allocate. This
+ * does, however, call the application provided allocator and that could call
+ * png_error (although that would be a bug in the application implementation.)
+ */
+PNG_INTERNAL_FUNCTION(png_voidp,png_malloc_base,(png_const_structrp png_ptr,
+ png_alloc_size_t size),PNG_ALLOCATED);
+
+#if defined(PNG_TEXT_SUPPORTED) || defined(PNG_sPLT_SUPPORTED) ||\
+ defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED)
+/* Internal array allocator, outputs no error or warning messages on failure,
+ * just returns NULL.
+ */
+PNG_INTERNAL_FUNCTION(png_voidp,png_malloc_array,(png_const_structrp png_ptr,
+ int nelements, size_t element_size),PNG_ALLOCATED);
+
+/* The same but an existing array is extended by add_elements. This function
+ * also memsets the new elements to 0 and copies the old elements. The old
+ * array is not freed or altered.
+ */
+PNG_INTERNAL_FUNCTION(png_voidp,png_realloc_array,(png_const_structrp png_ptr,
+ png_const_voidp array, int old_elements, int add_elements,
+ size_t element_size),PNG_ALLOCATED);
+#endif /* text, sPLT or unknown chunks */
+
+/* Magic to create a struct when there is no struct to call the user supplied
+ * memory allocators. Because error handling has not been set up the memory
+ * handlers can't safely call png_error, but this is an obscure and undocumented
+ * restriction so libpng has to assume that the 'free' handler, at least, might
+ * call png_error.
+ */
+PNG_INTERNAL_FUNCTION(png_structp,png_create_png_struct,
+ (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
+ png_error_ptr warn_fn, png_voidp mem_ptr, png_malloc_ptr malloc_fn,
+ png_free_ptr free_fn),PNG_ALLOCATED);
+
+/* Free memory from internal libpng struct */
+PNG_INTERNAL_FUNCTION(void,png_destroy_png_struct,(png_structrp png_ptr),
+ PNG_EMPTY);
+
+/* Free an allocated jmp_buf (always succeeds) */
+PNG_INTERNAL_FUNCTION(void,png_free_jmpbuf,(png_structrp png_ptr),PNG_EMPTY);
+
+/* Function to allocate memory for zlib. PNGAPI is disallowed. */
+PNG_INTERNAL_FUNCTION(voidpf,png_zalloc,(voidpf png_ptr, uInt items, uInt size),
+ PNG_ALLOCATED);
+
+/* Function to free memory for zlib. PNGAPI is disallowed. */
+PNG_INTERNAL_FUNCTION(void,png_zfree,(voidpf png_ptr, voidpf ptr),PNG_EMPTY);
+
+/* Next four functions are used internally as callbacks. PNGCBAPI is required
+ * but not PNG_EXPORT. PNGAPI added at libpng version 1.2.3, changed to
+ * PNGCBAPI at 1.5.0
+ */
+
+PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_default_read_data,(png_structp png_ptr,
+ png_bytep data, png_size_t length),PNG_EMPTY);
+
+#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
+PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_push_fill_buffer,(png_structp png_ptr,
+ png_bytep buffer, png_size_t length),PNG_EMPTY);
+#endif
+
+PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_default_write_data,(png_structp png_ptr,
+ png_bytep data, png_size_t length),PNG_EMPTY);
+
+#ifdef PNG_WRITE_FLUSH_SUPPORTED
+# ifdef PNG_STDIO_SUPPORTED
+PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_default_flush,(png_structp png_ptr),
+ PNG_EMPTY);
+# endif
+#endif
+
+/* Reset the CRC variable */
+PNG_INTERNAL_FUNCTION(void,png_reset_crc,(png_structrp png_ptr),PNG_EMPTY);
+
+/* Write the "data" buffer to whatever output you are using */
+PNG_INTERNAL_FUNCTION(void,png_write_data,(png_structrp png_ptr,
+ png_const_bytep data, png_size_t length),PNG_EMPTY);
+
+/* Read and check the PNG file signature */
+PNG_INTERNAL_FUNCTION(void,png_read_sig,(png_structrp png_ptr,
+ png_inforp info_ptr),PNG_EMPTY);
+
+/* Read the chunk header (length + type name) */
+PNG_INTERNAL_FUNCTION(png_uint_32,png_read_chunk_header,(png_structrp png_ptr),
+ PNG_EMPTY);
+
+/* Read data from whatever input you are using into the "data" buffer */
+PNG_INTERNAL_FUNCTION(void,png_read_data,(png_structrp png_ptr, png_bytep data,
+ png_size_t length),PNG_EMPTY);
+
+/* Read bytes into buf, and update png_ptr->crc */
+PNG_INTERNAL_FUNCTION(void,png_crc_read,(png_structrp png_ptr, png_bytep buf,
+ png_uint_32 length),PNG_EMPTY);
+
+/* Read "skip" bytes, read the file crc, and (optionally) verify png_ptr->crc */
+PNG_INTERNAL_FUNCTION(int,png_crc_finish,(png_structrp png_ptr,
+ png_uint_32 skip),PNG_EMPTY);
+
+/* Read the CRC from the file and compare it to the libpng calculated CRC */
+PNG_INTERNAL_FUNCTION(int,png_crc_error,(png_structrp png_ptr),PNG_EMPTY);
+
+/* Calculate the CRC over a section of data. Note that we are only
+ * passing a maximum of 64K on systems that have this as a memory limit,
+ * since this is the maximum buffer size we can specify.
+ */
+PNG_INTERNAL_FUNCTION(void,png_calculate_crc,(png_structrp png_ptr,
+ png_const_bytep ptr, png_size_t length),PNG_EMPTY);
+
+#ifdef PNG_WRITE_FLUSH_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_flush,(png_structrp png_ptr),PNG_EMPTY);
+#endif
+
+/* Write various chunks */
+
+/* Write the IHDR chunk, and update the png_struct with the necessary
+ * information.
+ */
+PNG_INTERNAL_FUNCTION(void,png_write_IHDR,(png_structrp png_ptr,
+ png_uint_32 width, png_uint_32 height, int bit_depth, int color_type,
+ int compression_method, int filter_method, int interlace_method),PNG_EMPTY);
+
+PNG_INTERNAL_FUNCTION(void,png_write_PLTE,(png_structrp png_ptr,
+ png_const_colorp palette, png_uint_32 num_pal),PNG_EMPTY);
+
+PNG_INTERNAL_FUNCTION(void,png_compress_IDAT,(png_structrp png_ptr,
+ png_const_bytep row_data, png_alloc_size_t row_data_length, int flush),
+ PNG_EMPTY);
+
+PNG_INTERNAL_FUNCTION(void,png_write_IEND,(png_structrp png_ptr),PNG_EMPTY);
+
+#ifdef PNG_WRITE_gAMA_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_write_gAMA_fixed,(png_structrp png_ptr,
+ png_fixed_point file_gamma),PNG_EMPTY);
+#endif
+
+#ifdef PNG_WRITE_sBIT_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_write_sBIT,(png_structrp png_ptr,
+ png_const_color_8p sbit, int color_type),PNG_EMPTY);
+#endif
+
+#ifdef PNG_WRITE_cHRM_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_write_cHRM_fixed,(png_structrp png_ptr,
+ const png_xy *xy), PNG_EMPTY);
+ /* The xy value must have been previously validated */
+#endif
+
+#ifdef PNG_WRITE_sRGB_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_write_sRGB,(png_structrp png_ptr,
+ int intent),PNG_EMPTY);
+#endif
+
+#ifdef PNG_WRITE_iCCP_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_write_iCCP,(png_structrp png_ptr,
+ png_const_charp name, png_const_bytep profile), PNG_EMPTY);
+ /* The profile must have been previously validated for correctness, the
+ * length comes from the first four bytes. Only the base, deflate,
+ * compression is supported.
+ */
+#endif
+
+#ifdef PNG_WRITE_sPLT_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_write_sPLT,(png_structrp png_ptr,
+ png_const_sPLT_tp palette),PNG_EMPTY);
+#endif
+
+#ifdef PNG_WRITE_tRNS_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_write_tRNS,(png_structrp png_ptr,
+ png_const_bytep trans, png_const_color_16p values, int number,
+ int color_type),PNG_EMPTY);
+#endif
+
+#ifdef PNG_WRITE_bKGD_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_write_bKGD,(png_structrp png_ptr,
+ png_const_color_16p values, int color_type),PNG_EMPTY);
+#endif
+
+#ifdef PNG_WRITE_hIST_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_write_hIST,(png_structrp png_ptr,
+ png_const_uint_16p hist, int num_hist),PNG_EMPTY);
+#endif
+
+/* Chunks that have keywords */
+#ifdef PNG_WRITE_tEXt_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_write_tEXt,(png_structrp png_ptr,
+ png_const_charp key, png_const_charp text, png_size_t text_len),PNG_EMPTY);
+#endif
+
+#ifdef PNG_WRITE_zTXt_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_write_zTXt,(png_structrp png_ptr, png_const_charp
+ key, png_const_charp text, int compression),PNG_EMPTY);
+#endif
+
+#ifdef PNG_WRITE_iTXt_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_write_iTXt,(png_structrp png_ptr,
+ int compression, png_const_charp key, png_const_charp lang,
+ png_const_charp lang_key, png_const_charp text),PNG_EMPTY);
+#endif
+
+#ifdef PNG_TEXT_SUPPORTED /* Added at version 1.0.14 and 1.2.4 */
+PNG_INTERNAL_FUNCTION(int,png_set_text_2,(png_const_structrp png_ptr,
+ png_inforp info_ptr, png_const_textp text_ptr, int num_text),PNG_EMPTY);
+#endif
+
+#ifdef PNG_WRITE_oFFs_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_write_oFFs,(png_structrp png_ptr,
+ png_int_32 x_offset, png_int_32 y_offset, int unit_type),PNG_EMPTY);
+#endif
+
+#ifdef PNG_WRITE_pCAL_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_write_pCAL,(png_structrp png_ptr,
+ png_charp purpose, png_int_32 X0, png_int_32 X1, int type, int nparams,
+ png_const_charp units, png_charpp params),PNG_EMPTY);
+#endif
+
+#ifdef PNG_WRITE_pHYs_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_write_pHYs,(png_structrp png_ptr,
+ png_uint_32 x_pixels_per_unit, png_uint_32 y_pixels_per_unit,
+ int unit_type),PNG_EMPTY);
+#endif
+
+#ifdef PNG_WRITE_tIME_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_write_tIME,(png_structrp png_ptr,
+ png_const_timep mod_time),PNG_EMPTY);
+#endif
+
+#ifdef PNG_WRITE_sCAL_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_write_sCAL_s,(png_structrp png_ptr,
+ int unit, png_const_charp width, png_const_charp height),PNG_EMPTY);
+#endif
+
+/* Called when finished processing a row of data */
+PNG_INTERNAL_FUNCTION(void,png_write_finish_row,(png_structrp png_ptr),
+ PNG_EMPTY);
+
+/* Internal use only. Called before first row of data */
+PNG_INTERNAL_FUNCTION(void,png_write_start_row,(png_structrp png_ptr),
+ PNG_EMPTY);
+
+/* Combine a row of data, dealing with alpha, etc. if requested. 'row' is an
+ * array of png_ptr->width pixels. If the image is not interlaced or this
+ * is the final pass this just does a memcpy, otherwise the "display" flag
+ * is used to determine whether to copy pixels that are not in the current pass.
+ *
+ * Because 'png_do_read_interlace' (below) replicates pixels this allows this
+ * function to achieve the documented 'blocky' appearance during interlaced read
+ * if display is 1 and the 'sparkle' appearance, where existing pixels in 'row'
+ * are not changed if they are not in the current pass, when display is 0.
+ *
+ * 'display' must be 0 or 1, otherwise the memcpy will be done regardless.
+ *
+ * The API always reads from the png_struct row buffer and always assumes that
+ * it is full width (png_do_read_interlace has already been called.)
+ *
+ * This function is only ever used to write to row buffers provided by the
+ * caller of the relevant libpng API and the row must have already been
+ * transformed by the read transformations.
+ *
+ * The PNG_USE_COMPILE_TIME_MASKS option causes generation of pre-computed
+ * bitmasks for use within the code, otherwise runtime generated masks are used.
+ * The default is compile time masks.
+ */
+#ifndef PNG_USE_COMPILE_TIME_MASKS
+# define PNG_USE_COMPILE_TIME_MASKS 1
+#endif
+PNG_INTERNAL_FUNCTION(void,png_combine_row,(png_const_structrp png_ptr,
+ png_bytep row, int display),PNG_EMPTY);
+
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+/* Expand an interlaced row: the 'row_info' describes the pass data that has
+ * been read in and must correspond to the pixels in 'row', the pixels are
+ * expanded (moved apart) in 'row' to match the final layout, when doing this
+ * the pixels are *replicated* to the intervening space. This is essential for
+ * the correct operation of png_combine_row, above.
+ */
+PNG_INTERNAL_FUNCTION(void,png_do_read_interlace,(png_row_infop row_info,
+ png_bytep row, int pass, png_uint_32 transformations),PNG_EMPTY);
+#endif
+
+/* GRR TO DO (2.0 or whenever): simplify other internal calling interfaces */
+
+#ifdef PNG_WRITE_INTERLACING_SUPPORTED
+/* Grab pixels out of a row for an interlaced pass */
+PNG_INTERNAL_FUNCTION(void,png_do_write_interlace,(png_row_infop row_info,
+ png_bytep row, int pass),PNG_EMPTY);
+#endif
+
+/* Unfilter a row: check the filter value before calling this, there is no point
+ * calling it for PNG_FILTER_VALUE_NONE.
+ */
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row,(png_structrp pp, png_row_infop
+ row_info, png_bytep row, png_const_bytep prev_row, int filter),PNG_EMPTY);
+
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_up_neon,(png_row_infop row_info,
+ png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub3_neon,(png_row_infop
+ row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub4_neon,(png_row_infop
+ row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg3_neon,(png_row_infop
+ row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg4_neon,(png_row_infop
+ row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth3_neon,(png_row_infop
+ row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_neon,(png_row_infop
+ row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+
+/* Choose the best filter to use and filter the row data */
+PNG_INTERNAL_FUNCTION(void,png_write_find_filter,(png_structrp png_ptr,
+ png_row_infop row_info),PNG_EMPTY);
+
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_read_IDAT_data,(png_structrp png_ptr,
+ png_bytep output, png_alloc_size_t avail_out),PNG_EMPTY);
+ /* Read 'avail_out' bytes of data from the IDAT stream. If the output buffer
+ * is NULL the function checks, instead, for the end of the stream. In this
+ * case a benign error will be issued if the stream end is not found or if
+ * extra data has to be consumed.
+ */
+PNG_INTERNAL_FUNCTION(void,png_read_finish_IDAT,(png_structrp png_ptr),
+ PNG_EMPTY);
+ /* This cleans up when the IDAT LZ stream does not end when the last image
+ * byte is read; there is still some pending input.
+ */
+
+PNG_INTERNAL_FUNCTION(void,png_read_finish_row,(png_structrp png_ptr),
+ PNG_EMPTY);
+ /* Finish a row while reading, dealing with interlacing passes, etc. */
+#endif /* SEQUENTIAL_READ */
+
+/* Initialize the row buffers, etc. */
+PNG_INTERNAL_FUNCTION(void,png_read_start_row,(png_structrp png_ptr),PNG_EMPTY);
+
+#if PNG_ZLIB_VERNUM >= 0x1240
+PNG_INTERNAL_FUNCTION(int,png_zlib_inflate,(png_structrp png_ptr, int flush),
+ PNG_EMPTY);
+# define PNG_INFLATE(pp, flush) png_zlib_inflate(pp, flush)
+#else /* Zlib < 1.2.4 */
+# define PNG_INFLATE(pp, flush) inflate(&(pp)->zstream, flush)
+#endif /* Zlib < 1.2.4 */
+
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
+/* Optional call to update the users info structure */
+PNG_INTERNAL_FUNCTION(void,png_read_transform_info,(png_structrp png_ptr,
+ png_inforp info_ptr),PNG_EMPTY);
+#endif
+
+/* Shared transform functions, defined in pngtran.c */
+#if defined(PNG_WRITE_FILLER_SUPPORTED) || \
+ defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
+PNG_INTERNAL_FUNCTION(void,png_do_strip_channel,(png_row_infop row_info,
+ png_bytep row, int at_start),PNG_EMPTY);
+#endif
+
+#ifdef PNG_16BIT_SUPPORTED
+#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
+PNG_INTERNAL_FUNCTION(void,png_do_swap,(png_row_infop row_info,
+ png_bytep row),PNG_EMPTY);
+#endif
+#endif
+
+#if defined(PNG_READ_PACKSWAP_SUPPORTED) || \
+ defined(PNG_WRITE_PACKSWAP_SUPPORTED)
+PNG_INTERNAL_FUNCTION(void,png_do_packswap,(png_row_infop row_info,
+ png_bytep row),PNG_EMPTY);
+#endif
+
+#if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
+PNG_INTERNAL_FUNCTION(void,png_do_invert,(png_row_infop row_info,
+ png_bytep row),PNG_EMPTY);
+#endif
+
+#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
+PNG_INTERNAL_FUNCTION(void,png_do_bgr,(png_row_infop row_info,
+ png_bytep row),PNG_EMPTY);
+#endif
+
+/* The following decodes the appropriate chunks, and does error correction,
+ * then calls the appropriate callback for the chunk if it is valid.
+ */
+
+/* Decode the IHDR chunk */
+PNG_INTERNAL_FUNCTION(void,png_handle_IHDR,(png_structrp png_ptr,
+ png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_handle_PLTE,(png_structrp png_ptr,
+ png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_handle_IEND,(png_structrp png_ptr,
+ png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
+
+#ifdef PNG_READ_bKGD_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_handle_bKGD,(png_structrp png_ptr,
+ png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
+#endif
+
+#ifdef PNG_READ_cHRM_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_handle_cHRM,(png_structrp png_ptr,
+ png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
+#endif
+
+#ifdef PNG_READ_gAMA_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_handle_gAMA,(png_structrp png_ptr,
+ png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
+#endif
+
+#ifdef PNG_READ_hIST_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_handle_hIST,(png_structrp png_ptr,
+ png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
+#endif
+
+#ifdef PNG_READ_iCCP_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_handle_iCCP,(png_structrp png_ptr,
+ png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
+#endif /* READ_iCCP */
+
+#ifdef PNG_READ_iTXt_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_handle_iTXt,(png_structrp png_ptr,
+ png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
+#endif
+
+#ifdef PNG_READ_oFFs_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_handle_oFFs,(png_structrp png_ptr,
+ png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
+#endif
+
+#ifdef PNG_READ_pCAL_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_handle_pCAL,(png_structrp png_ptr,
+ png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
+#endif
+
+#ifdef PNG_READ_pHYs_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_handle_pHYs,(png_structrp png_ptr,
+ png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
+#endif
+
+#ifdef PNG_READ_sBIT_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_handle_sBIT,(png_structrp png_ptr,
+ png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
+#endif
+
+#ifdef PNG_READ_sCAL_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_handle_sCAL,(png_structrp png_ptr,
+ png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
+#endif
+
+#ifdef PNG_READ_sPLT_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_handle_sPLT,(png_structrp png_ptr,
+ png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
+#endif /* READ_sPLT */
+
+#ifdef PNG_READ_sRGB_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_handle_sRGB,(png_structrp png_ptr,
+ png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
+#endif
+
+#ifdef PNG_READ_tEXt_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_handle_tEXt,(png_structrp png_ptr,
+ png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
+#endif
+
+#ifdef PNG_READ_tIME_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_handle_tIME,(png_structrp png_ptr,
+ png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
+#endif
+
+#ifdef PNG_READ_tRNS_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_handle_tRNS,(png_structrp png_ptr,
+ png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
+#endif
+
+#ifdef PNG_READ_zTXt_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_handle_zTXt,(png_structrp png_ptr,
+ png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
+#endif
+
+PNG_INTERNAL_FUNCTION(void,png_check_chunk_name,(png_structrp png_ptr,
+ png_uint_32 chunk_name),PNG_EMPTY);
+
+PNG_INTERNAL_FUNCTION(void,png_handle_unknown,(png_structrp png_ptr,
+ png_inforp info_ptr, png_uint_32 length, int keep),PNG_EMPTY);
+ /* This is the function that gets called for unknown chunks. The 'keep'
+ * argument is either non-zero for a known chunk that has been set to be
+ * handled as unknown or zero for an unknown chunk. By default the function
+ * just skips the chunk or errors out if it is critical.
+ */
+
+#if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED) ||\
+ defined(PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
+PNG_INTERNAL_FUNCTION(int,png_chunk_unknown_handling,
+ (png_const_structrp png_ptr, png_uint_32 chunk_name),PNG_EMPTY);
+ /* Exactly as the API png_handle_as_unknown() except that the argument is a
+ * 32-bit chunk name, not a string.
+ */
+#endif /* READ_UNKNOWN_CHUNKS || HANDLE_AS_UNKNOWN */
+
+/* Handle the transformations for reading and writing */
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_do_read_transformations,(png_structrp png_ptr,
+ png_row_infop row_info),PNG_EMPTY);
+#endif
+#ifdef PNG_WRITE_TRANSFORMS_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_do_write_transformations,(png_structrp png_ptr,
+ png_row_infop row_info),PNG_EMPTY);
+#endif
+
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_init_read_transformations,(png_structrp png_ptr),
+ PNG_EMPTY);
+#endif
+
+#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_push_read_chunk,(png_structrp png_ptr,
+ png_inforp info_ptr),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_push_read_sig,(png_structrp png_ptr,
+ png_inforp info_ptr),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_push_check_crc,(png_structrp png_ptr),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_push_save_buffer,(png_structrp png_ptr),
+ PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_push_restore_buffer,(png_structrp png_ptr,
+ png_bytep buffer, png_size_t buffer_length),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_push_read_IDAT,(png_structrp png_ptr),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_process_IDAT_data,(png_structrp png_ptr,
+ png_bytep buffer, png_size_t buffer_length),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_push_process_row,(png_structrp png_ptr),
+ PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_push_handle_unknown,(png_structrp png_ptr,
+ png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_push_have_info,(png_structrp png_ptr,
+ png_inforp info_ptr),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_push_have_end,(png_structrp png_ptr,
+ png_inforp info_ptr),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_push_have_row,(png_structrp png_ptr,
+ png_bytep row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_push_read_end,(png_structrp png_ptr,
+ png_inforp info_ptr),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_process_some_data,(png_structrp png_ptr,
+ png_inforp info_ptr),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_push_finish_row,(png_structrp png_ptr),
+ PNG_EMPTY);
+# ifdef PNG_READ_tEXt_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_push_handle_tEXt,(png_structrp png_ptr,
+ png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_push_read_tEXt,(png_structrp png_ptr,
+ png_inforp info_ptr),PNG_EMPTY);
+# endif
+# ifdef PNG_READ_zTXt_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_push_handle_zTXt,(png_structrp png_ptr,
+ png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_push_read_zTXt,(png_structrp png_ptr,
+ png_inforp info_ptr),PNG_EMPTY);
+# endif
+# ifdef PNG_READ_iTXt_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_push_handle_iTXt,(png_structrp png_ptr,
+ png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_push_read_iTXt,(png_structrp png_ptr,
+ png_inforp info_ptr),PNG_EMPTY);
+# endif
+
+#endif /* PROGRESSIVE_READ */
+
+/* Added at libpng version 1.6.0 */
+#ifdef PNG_GAMMA_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_colorspace_set_gamma,(png_const_structrp png_ptr,
+ png_colorspacerp colorspace, png_fixed_point gAMA), PNG_EMPTY);
+ /* Set the colorspace gamma with a value provided by the application or by
+ * the gAMA chunk on read. The value will override anything set by an ICC
+ * profile.
+ */
+
+PNG_INTERNAL_FUNCTION(void,png_colorspace_sync_info,(png_const_structrp png_ptr,
+ png_inforp info_ptr), PNG_EMPTY);
+ /* Synchronize the info 'valid' flags with the colorspace */
+
+PNG_INTERNAL_FUNCTION(void,png_colorspace_sync,(png_const_structrp png_ptr,
+ png_inforp info_ptr), PNG_EMPTY);
+ /* Copy the png_struct colorspace to the info_struct and call the above to
+ * synchronize the flags. Checks for NULL info_ptr and does nothing.
+ */
+#endif
+
+/* Added at libpng version 1.4.0 */
+#ifdef PNG_COLORSPACE_SUPPORTED
+/* These internal functions are for maintaining the colorspace structure within
+ * a png_info or png_struct (or, indeed, both).
+ */
+PNG_INTERNAL_FUNCTION(int,png_colorspace_set_chromaticities,
+ (png_const_structrp png_ptr, png_colorspacerp colorspace, const png_xy *xy,
+ int preferred), PNG_EMPTY);
+
+PNG_INTERNAL_FUNCTION(int,png_colorspace_set_endpoints,
+ (png_const_structrp png_ptr, png_colorspacerp colorspace, const png_XYZ *XYZ,
+ int preferred), PNG_EMPTY);
+
+#ifdef PNG_sRGB_SUPPORTED
+PNG_INTERNAL_FUNCTION(int,png_colorspace_set_sRGB,(png_const_structrp png_ptr,
+ png_colorspacerp colorspace, int intent), PNG_EMPTY);
+ /* This does set the colorspace gAMA and cHRM values too, but doesn't set the
+ * flags to write them, if it returns false there was a problem and an error
+ * message has already been output (but the colorspace may still need to be
+ * synced to record the invalid flag).
+ */
+#endif /* sRGB */
+
+#ifdef PNG_iCCP_SUPPORTED
+PNG_INTERNAL_FUNCTION(int,png_colorspace_set_ICC,(png_const_structrp png_ptr,
+ png_colorspacerp colorspace, png_const_charp name,
+ png_uint_32 profile_length, png_const_bytep profile, int color_type),
+ PNG_EMPTY);
+ /* The 'name' is used for information only */
+
+/* Routines for checking parts of an ICC profile. */
+PNG_INTERNAL_FUNCTION(int,png_icc_check_length,(png_const_structrp png_ptr,
+ png_colorspacerp colorspace, png_const_charp name,
+ png_uint_32 profile_length), PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(int,png_icc_check_header,(png_const_structrp png_ptr,
+ png_colorspacerp colorspace, png_const_charp name,
+ png_uint_32 profile_length,
+ png_const_bytep profile /* first 132 bytes only */, int color_type),
+ PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(int,png_icc_check_tag_table,(png_const_structrp png_ptr,
+ png_colorspacerp colorspace, png_const_charp name,
+ png_uint_32 profile_length,
+ png_const_bytep profile /* header plus whole tag table */), PNG_EMPTY);
+#ifdef PNG_sRGB_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_icc_set_sRGB,(
+ png_const_structrp png_ptr, png_colorspacerp colorspace,
+ png_const_bytep profile, uLong adler), PNG_EMPTY);
+ /* 'adler' is the Adler32 checksum of the uncompressed profile data. It may
+ * be zero to indicate that it is not available. It is used, if provided,
+ * as a fast check on the profile when checking to see if it is sRGB.
+ */
+#endif
+#endif /* iCCP */
+
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_colorspace_set_rgb_coefficients,
+ (png_structrp png_ptr), PNG_EMPTY);
+ /* Set the rgb_to_gray coefficients from the colorspace Y values */
+#endif /* READ_RGB_TO_GRAY */
+#endif /* COLORSPACE */
+
+/* Added at libpng version 1.4.0 */
+PNG_INTERNAL_FUNCTION(void,png_check_IHDR,(png_const_structrp png_ptr,
+ png_uint_32 width, png_uint_32 height, int bit_depth,
+ int color_type, int interlace_type, int compression_type,
+ int filter_type),PNG_EMPTY);
+
+/* Added at libpng version 1.5.10 */
+#if defined(PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED) || \
+ defined(PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED)
+PNG_INTERNAL_FUNCTION(void,png_do_check_palette_indexes,
+ (png_structrp png_ptr, png_row_infop row_info),PNG_EMPTY);
+#endif
+
+#if defined(PNG_FLOATING_POINT_SUPPORTED) && defined(PNG_ERROR_TEXT_SUPPORTED)
+PNG_INTERNAL_FUNCTION(void,png_fixed_error,(png_const_structrp png_ptr,
+ png_const_charp name),PNG_NORETURN);
+#endif
+
+/* Puts 'string' into 'buffer' at buffer[pos], taking care never to overwrite
+ * the end. Always leaves the buffer nul terminated. Never errors out (and
+ * there is no error code.)
+ */
+PNG_INTERNAL_FUNCTION(size_t,png_safecat,(png_charp buffer, size_t bufsize,
+ size_t pos, png_const_charp string),PNG_EMPTY);
+
+/* Various internal functions to handle formatted warning messages, currently
+ * only implemented for warnings.
+ */
+#if defined(PNG_WARNINGS_SUPPORTED) || defined(PNG_TIME_RFC1123_SUPPORTED)
+/* Utility to dump an unsigned value into a buffer, given a start pointer and
+ * and end pointer (which should point just *beyond* the end of the buffer!)
+ * Returns the pointer to the start of the formatted string. This utility only
+ * does unsigned values.
+ */
+PNG_INTERNAL_FUNCTION(png_charp,png_format_number,(png_const_charp start,
+ png_charp end, int format, png_alloc_size_t number),PNG_EMPTY);
+
+/* Convenience macro that takes an array: */
+#define PNG_FORMAT_NUMBER(buffer,format,number) \
+ png_format_number(buffer, buffer + (sizeof buffer), format, number)
+
+/* Suggested size for a number buffer (enough for 64 bits and a sign!) */
+#define PNG_NUMBER_BUFFER_SIZE 24
+
+/* These are the integer formats currently supported, the name is formed from
+ * the standard printf(3) format string.
+ */
+#define PNG_NUMBER_FORMAT_u 1 /* chose unsigned API! */
+#define PNG_NUMBER_FORMAT_02u 2
+#define PNG_NUMBER_FORMAT_d 1 /* chose signed API! */
+#define PNG_NUMBER_FORMAT_02d 2
+#define PNG_NUMBER_FORMAT_x 3
+#define PNG_NUMBER_FORMAT_02x 4
+#define PNG_NUMBER_FORMAT_fixed 5 /* choose the signed API */
+#endif
+
+#ifdef PNG_WARNINGS_SUPPORTED
+/* New defines and members adding in libpng-1.5.4 */
+# define PNG_WARNING_PARAMETER_SIZE 32
+# define PNG_WARNING_PARAMETER_COUNT 8 /* Maximum 9; see pngerror.c */
+
+/* An l-value of this type has to be passed to the APIs below to cache the
+ * values of the parameters to a formatted warning message.
+ */
+typedef char png_warning_parameters[PNG_WARNING_PARAMETER_COUNT][
+ PNG_WARNING_PARAMETER_SIZE];
+
+PNG_INTERNAL_FUNCTION(void,png_warning_parameter,(png_warning_parameters p,
+ int number, png_const_charp string),PNG_EMPTY);
+ /* Parameters are limited in size to PNG_WARNING_PARAMETER_SIZE characters,
+ * including the trailing '\0'.
+ */
+PNG_INTERNAL_FUNCTION(void,png_warning_parameter_unsigned,
+ (png_warning_parameters p, int number, int format, png_alloc_size_t value),
+ PNG_EMPTY);
+ /* Use png_alloc_size_t because it is an unsigned type as big as any we
+ * need to output. Use the following for a signed value.
+ */
+PNG_INTERNAL_FUNCTION(void,png_warning_parameter_signed,
+ (png_warning_parameters p, int number, int format, png_int_32 value),
+ PNG_EMPTY);
+
+PNG_INTERNAL_FUNCTION(void,png_formatted_warning,(png_const_structrp png_ptr,
+ png_warning_parameters p, png_const_charp message),PNG_EMPTY);
+ /* 'message' follows the X/Open approach of using @1, @2 to insert
+ * parameters previously supplied using the above functions. Errors in
+ * specifying the parameters will simply result in garbage substitutions.
+ */
+#endif
+
+#ifdef PNG_BENIGN_ERRORS_SUPPORTED
+/* Application errors (new in 1.6); use these functions (declared below) for
+ * errors in the parameters or order of API function calls on read. The
+ * 'warning' should be used for an error that can be handled completely; the
+ * 'error' for one which can be handled safely but which may lose application
+ * information or settings.
+ *
+ * By default these both result in a png_error call prior to release, while in a
+ * released version the 'warning' is just a warning. However if the application
+ * explicitly disables benign errors (explicitly permitting the code to lose
+ * information) they both turn into warnings.
+ *
+ * If benign errors aren't supported they end up as the corresponding base call
+ * (png_warning or png_error.)
+ */
+PNG_INTERNAL_FUNCTION(void,png_app_warning,(png_const_structrp png_ptr,
+ png_const_charp message),PNG_EMPTY);
+ /* The application provided invalid parameters to an API function or called
+ * an API function at the wrong time, libpng can completely recover.
+ */
+
+PNG_INTERNAL_FUNCTION(void,png_app_error,(png_const_structrp png_ptr,
+ png_const_charp message),PNG_EMPTY);
+ /* As above but libpng will ignore the call, or attempt some other partial
+ * recovery from the error.
+ */
+#else
+# define png_app_warning(pp,s) png_warning(pp,s)
+# define png_app_error(pp,s) png_error(pp,s)
+#endif
+
+PNG_INTERNAL_FUNCTION(void,png_chunk_report,(png_const_structrp png_ptr,
+ png_const_charp message, int error),PNG_EMPTY);
+ /* Report a recoverable issue in chunk data. On read this is used to report
+ * a problem found while reading a particular chunk and the
+ * png_chunk_benign_error or png_chunk_warning function is used as
+ * appropriate. On write this is used to report an error that comes from
+ * data set via an application call to a png_set_ API and png_app_error or
+ * png_app_warning is used as appropriate.
+ *
+ * The 'error' parameter must have one of the following values:
+ */
+#define PNG_CHUNK_WARNING 0 /* never an error */
+#define PNG_CHUNK_WRITE_ERROR 1 /* an error only on write */
+#define PNG_CHUNK_ERROR 2 /* always an error */
+
+/* ASCII to FP interfaces, currently only implemented if sCAL
+ * support is required.
+ */
+#if defined(PNG_sCAL_SUPPORTED)
+/* MAX_DIGITS is actually the maximum number of characters in an sCAL
+ * width or height, derived from the precision (number of significant
+ * digits - a build time settable option) and assumptions about the
+ * maximum ridiculous exponent.
+ */
+#define PNG_sCAL_MAX_DIGITS (PNG_sCAL_PRECISION+1/*.*/+1/*E*/+10/*exponent*/)
+
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_ascii_from_fp,(png_const_structrp png_ptr,
+ png_charp ascii, png_size_t size, double fp, unsigned int precision),
+ PNG_EMPTY);
+#endif /* FLOATING_POINT */
+
+#ifdef PNG_FIXED_POINT_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_ascii_from_fixed,(png_const_structrp png_ptr,
+ png_charp ascii, png_size_t size, png_fixed_point fp),PNG_EMPTY);
+#endif /* FIXED_POINT */
+#endif /* sCAL */
+
+#if defined(PNG_sCAL_SUPPORTED) || defined(PNG_pCAL_SUPPORTED)
+/* An internal API to validate the format of a floating point number.
+ * The result is the index of the next character. If the number is
+ * not valid it will be the index of a character in the supposed number.
+ *
+ * The format of a number is defined in the PNG extensions specification
+ * and this API is strictly conformant to that spec, not anyone elses!
+ *
+ * The format as a regular expression is:
+ *
+ * [+-]?[0-9]+.?([Ee][+-]?[0-9]+)?
+ *
+ * or:
+ *
+ * [+-]?.[0-9]+(.[0-9]+)?([Ee][+-]?[0-9]+)?
+ *
+ * The complexity is that either integer or fraction must be present and the
+ * fraction is permitted to have no digits only if the integer is present.
+ *
+ * NOTE: The dangling E problem.
+ * There is a PNG valid floating point number in the following:
+ *
+ * PNG floating point numbers are not greedy.
+ *
+ * Working this out requires *TWO* character lookahead (because of the
+ * sign), the parser does not do this - it will fail at the 'r' - this
+ * doesn't matter for PNG sCAL chunk values, but it requires more care
+ * if the value were ever to be embedded in something more complex. Use
+ * ANSI-C strtod if you need the lookahead.
+ */
+/* State table for the parser. */
+#define PNG_FP_INTEGER 0 /* before or in integer */
+#define PNG_FP_FRACTION 1 /* before or in fraction */
+#define PNG_FP_EXPONENT 2 /* before or in exponent */
+#define PNG_FP_STATE 3 /* mask for the above */
+#define PNG_FP_SAW_SIGN 4 /* Saw +/- in current state */
+#define PNG_FP_SAW_DIGIT 8 /* Saw a digit in current state */
+#define PNG_FP_SAW_DOT 16 /* Saw a dot in current state */
+#define PNG_FP_SAW_E 32 /* Saw an E (or e) in current state */
+#define PNG_FP_SAW_ANY 60 /* Saw any of the above 4 */
+
+/* These three values don't affect the parser. They are set but not used.
+ */
+#define PNG_FP_WAS_VALID 64 /* Preceding substring is a valid fp number */
+#define PNG_FP_NEGATIVE 128 /* A negative number, including "-0" */
+#define PNG_FP_NONZERO 256 /* A non-zero value */
+#define PNG_FP_STICKY 448 /* The above three flags */
+
+/* This is available for the caller to store in 'state' if required. Do not
+ * call the parser after setting it (the parser sometimes clears it.)
+ */
+#define PNG_FP_INVALID 512 /* Available for callers as a distinct value */
+
+/* Result codes for the parser (boolean - true meants ok, false means
+ * not ok yet.)
+ */
+#define PNG_FP_MAYBE 0 /* The number may be valid in the future */
+#define PNG_FP_OK 1 /* The number is valid */
+
+/* Tests on the sticky non-zero and negative flags. To pass these checks
+ * the state must also indicate that the whole number is valid - this is
+ * achieved by testing PNG_FP_SAW_DIGIT (see the implementation for why this
+ * is equivalent to PNG_FP_OK above.)
+ */
+#define PNG_FP_NZ_MASK (PNG_FP_SAW_DIGIT | PNG_FP_NEGATIVE | PNG_FP_NONZERO)
+ /* NZ_MASK: the string is valid and a non-zero negative value */
+#define PNG_FP_Z_MASK (PNG_FP_SAW_DIGIT | PNG_FP_NONZERO)
+ /* Z MASK: the string is valid and a non-zero value. */
+ /* PNG_FP_SAW_DIGIT: the string is valid. */
+#define PNG_FP_IS_ZERO(state) (((state) & PNG_FP_Z_MASK) == PNG_FP_SAW_DIGIT)
+#define PNG_FP_IS_POSITIVE(state) (((state) & PNG_FP_NZ_MASK) == PNG_FP_Z_MASK)
+#define PNG_FP_IS_NEGATIVE(state) (((state) & PNG_FP_NZ_MASK) == PNG_FP_NZ_MASK)
+
+/* The actual parser. This can be called repeatedly. It updates
+ * the index into the string and the state variable (which must
+ * be initialized to 0). It returns a result code, as above. There
+ * is no point calling the parser any more if it fails to advance to
+ * the end of the string - it is stuck on an invalid character (or
+ * terminated by '\0').
+ *
+ * Note that the pointer will consume an E or even an E+ and then leave
+ * a 'maybe' state even though a preceding integer.fraction is valid.
+ * The PNG_FP_WAS_VALID flag indicates that a preceding substring was
+ * a valid number. It's possible to recover from this by calling
+ * the parser again (from the start, with state 0) but with a string
+ * that omits the last character (i.e. set the size to the index of
+ * the problem character.) This has not been tested within libpng.
+ */
+PNG_INTERNAL_FUNCTION(int,png_check_fp_number,(png_const_charp string,
+ png_size_t size, int *statep, png_size_tp whereami),PNG_EMPTY);
+
+/* This is the same but it checks a complete string and returns true
+ * only if it just contains a floating point number. As of 1.5.4 this
+ * function also returns the state at the end of parsing the number if
+ * it was valid (otherwise it returns 0.) This can be used for testing
+ * for negative or zero values using the sticky flag.
+ */
+PNG_INTERNAL_FUNCTION(int,png_check_fp_string,(png_const_charp string,
+ png_size_t size),PNG_EMPTY);
+#endif /* pCAL || sCAL */
+
+#if defined(PNG_GAMMA_SUPPORTED) ||\
+ defined(PNG_INCH_CONVERSIONS_SUPPORTED) || defined(PNG_READ_pHYs_SUPPORTED)
+/* Added at libpng version 1.5.0 */
+/* This is a utility to provide a*times/div (rounded) and indicate
+ * if there is an overflow. The result is a boolean - false (0)
+ * for overflow, true (1) if no overflow, in which case *res
+ * holds the result.
+ */
+PNG_INTERNAL_FUNCTION(int,png_muldiv,(png_fixed_point_p res, png_fixed_point a,
+ png_int_32 multiplied_by, png_int_32 divided_by),PNG_EMPTY);
+#endif
+
+#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_INCH_CONVERSIONS_SUPPORTED)
+/* Same deal, but issue a warning on overflow and return 0. */
+PNG_INTERNAL_FUNCTION(png_fixed_point,png_muldiv_warn,
+ (png_const_structrp png_ptr, png_fixed_point a, png_int_32 multiplied_by,
+ png_int_32 divided_by),PNG_EMPTY);
+#endif
+
+#ifdef PNG_GAMMA_SUPPORTED
+/* Calculate a reciprocal - used for gamma values. This returns
+ * 0 if the argument is 0 in order to maintain an undefined value;
+ * there are no warnings.
+ */
+PNG_INTERNAL_FUNCTION(png_fixed_point,png_reciprocal,(png_fixed_point a),
+ PNG_EMPTY);
+
+#ifdef PNG_READ_GAMMA_SUPPORTED
+/* The same but gives a reciprocal of the product of two fixed point
+ * values. Accuracy is suitable for gamma calculations but this is
+ * not exact - use png_muldiv for that. Only required at present on read.
+ */
+PNG_INTERNAL_FUNCTION(png_fixed_point,png_reciprocal2,(png_fixed_point a,
+ png_fixed_point b),PNG_EMPTY);
+#endif
+
+/* Return true if the gamma value is significantly different from 1.0 */
+PNG_INTERNAL_FUNCTION(int,png_gamma_significant,(png_fixed_point gamma_value),
+ PNG_EMPTY);
+#endif
+
+#ifdef PNG_READ_GAMMA_SUPPORTED
+/* Internal fixed point gamma correction. These APIs are called as
+ * required to convert single values - they don't need to be fast,
+ * they are not used when processing image pixel values.
+ *
+ * While the input is an 'unsigned' value it must actually be the
+ * correct bit value - 0..255 or 0..65535 as required.
+ */
+PNG_INTERNAL_FUNCTION(png_uint_16,png_gamma_correct,(png_structrp png_ptr,
+ unsigned int value, png_fixed_point gamma_value),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(png_uint_16,png_gamma_16bit_correct,(unsigned int value,
+ png_fixed_point gamma_value),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(png_byte,png_gamma_8bit_correct,(unsigned int value,
+ png_fixed_point gamma_value),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_destroy_gamma_table,(png_structrp png_ptr),
+ PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_build_gamma_table,(png_structrp png_ptr,
+ int bit_depth),PNG_EMPTY);
+#endif
+
+/* SIMPLIFIED READ/WRITE SUPPORT */
+#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) ||\
+ defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
+/* The internal structure that png_image::opaque points to. */
+typedef struct png_control
+{
+ png_structp png_ptr;
+ png_infop info_ptr;
+ png_voidp error_buf; /* Always a jmp_buf at present. */
+
+ png_const_bytep memory; /* Memory buffer. */
+ png_size_t size; /* Size of the memory buffer. */
+
+ unsigned int for_write :1; /* Otherwise it is a read structure */
+ unsigned int owned_file :1; /* We own the file in io_ptr */
+} png_control;
+
+/* Return the pointer to the jmp_buf from a png_control: necessary because C
+ * does not reveal the type of the elements of jmp_buf.
+ */
+#ifdef __cplusplus
+# define png_control_jmp_buf(pc) (((jmp_buf*)((pc)->error_buf))[0])
+#else
+# define png_control_jmp_buf(pc) ((pc)->error_buf)
+#endif
+
+/* Utility to safely execute a piece of libpng code catching and logging any
+ * errors that might occur. Returns true on success, false on failure (either
+ * of the function or as a result of a png_error.)
+ */
+PNG_INTERNAL_CALLBACK(void,png_safe_error,(png_structp png_ptr,
+ png_const_charp error_message),PNG_NORETURN);
+
+#ifdef PNG_WARNINGS_SUPPORTED
+PNG_INTERNAL_CALLBACK(void,png_safe_warning,(png_structp png_ptr,
+ png_const_charp warning_message),PNG_EMPTY);
+#else
+# define png_safe_warning 0/*dummy argument*/
+#endif
+
+PNG_INTERNAL_FUNCTION(int,png_safe_execute,(png_imagep image,
+ int (*function)(png_voidp), png_voidp arg),PNG_EMPTY);
+
+/* Utility to log an error; this also cleans up the png_image; the function
+ * always returns 0 (false).
+ */
+PNG_INTERNAL_FUNCTION(int,png_image_error,(png_imagep image,
+ png_const_charp error_message),PNG_EMPTY);
+
+#ifndef PNG_SIMPLIFIED_READ_SUPPORTED
+/* png_image_free is used by the write code but not exported */
+PNG_INTERNAL_FUNCTION(void, png_image_free, (png_imagep image), PNG_EMPTY);
+#endif /* !SIMPLIFIED_READ */
+
+#endif /* SIMPLIFIED READ/WRITE */
+
+/* These are initialization functions for hardware specific PNG filter
+ * optimizations; list these here then select the appropriate one at compile
+ * time using the macro PNG_FILTER_OPTIMIZATIONS. If the macro is not defined
+ * the generic code is used.
+ */
+#ifdef PNG_FILTER_OPTIMIZATIONS
+PNG_INTERNAL_FUNCTION(void, PNG_FILTER_OPTIMIZATIONS, (png_structp png_ptr,
+ unsigned int bpp), PNG_EMPTY);
+ /* Just declare the optimization that will be used */
+#else
+ /* List *all* the possible optimizations here - this branch is required if
+ * the builder of libpng passes the definition of PNG_FILTER_OPTIMIZATIONS in
+ * CFLAGS in place of CPPFLAGS *and* uses symbol prefixing.
+ */
+PNG_INTERNAL_FUNCTION(void, png_init_filter_functions_neon,
+ (png_structp png_ptr, unsigned int bpp), PNG_EMPTY);
+#endif
+
+/* Maintainer: Put new private prototypes here ^ */
+
+#include "pngdebug.h"
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* PNG_VERSION_INFO_ONLY */
+#endif /* PNGPRIV_H */
diff --git a/third_party/lpng_v163/pngread.c b/third_party/libpng/pngread.c
similarity index 88%
rename from third_party/lpng_v163/pngread.c
rename to third_party/libpng/pngread.c
index b30c5a1..9cb4d2e 100644
--- a/third_party/lpng_v163/pngread.c
+++ b/third_party/libpng/pngread.c
@@ -1,3999 +1,4136 @@
-/* pngread.c - read a PNG file
- *
- * Last changed in libpng 1.6.1 [March 28, 2013]
- * Copyright (c) 1998-2013 Glenn Randers-Pehrson
- * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
- * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
- *
- * This code is released under the libpng license.
- * For conditions of distribution and use, see the disclaimer
- * and license in png.h
- *
- * This file contains routines that an application calls directly to
- * read a PNG file or stream.
- */
-
-#include "pngpriv.h"
-#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) && defined(PNG_STDIO_SUPPORTED)
-# include <errno.h>
-#endif
-
-#ifdef PNG_READ_SUPPORTED
-
-/* Create a PNG structure for reading, and allocate any memory needed. */
-PNG_FUNCTION(png_structp,PNGAPI
-png_create_read_struct,(png_const_charp user_png_ver, png_voidp error_ptr,
- png_error_ptr error_fn, png_error_ptr warn_fn),PNG_ALLOCATED)
-{
-#ifndef PNG_USER_MEM_SUPPORTED
- png_structp png_ptr = png_create_png_struct(user_png_ver, error_ptr,
- error_fn, warn_fn, NULL, NULL, NULL);
-#else
- return png_create_read_struct_2(user_png_ver, error_ptr, error_fn,
- warn_fn, NULL, NULL, NULL);
-}
-
-/* Alternate create PNG structure for reading, and allocate any memory
- * needed.
- */
-PNG_FUNCTION(png_structp,PNGAPI
-png_create_read_struct_2,(png_const_charp user_png_ver, png_voidp error_ptr,
- png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
- png_malloc_ptr malloc_fn, png_free_ptr free_fn),PNG_ALLOCATED)
-{
- png_structp png_ptr = png_create_png_struct(user_png_ver, error_ptr,
- error_fn, warn_fn, mem_ptr, malloc_fn, free_fn);
-#endif /* PNG_USER_MEM_SUPPORTED */
-
- if (png_ptr != NULL)
- {
- png_ptr->mode = PNG_IS_READ_STRUCT;
-
- /* Added in libpng-1.6.0; this can be used to detect a read structure if
- * required (it will be zero in a write structure.)
- */
-# ifdef PNG_SEQUENTIAL_READ_SUPPORTED
- png_ptr->IDAT_read_size = PNG_IDAT_READ_SIZE;
-# endif
-
-# ifdef PNG_BENIGN_READ_ERRORS_SUPPORTED
- png_ptr->flags |= PNG_FLAG_BENIGN_ERRORS_WARN;
-
- /* In stable builds only warn if an application error can be completely
- * handled.
- */
-# if PNG_LIBPNG_BUILD_BASE_TYPE >= PNG_LIBPNG_BUILD_RC
- png_ptr->flags |= PNG_FLAG_APP_WARNINGS_WARN;
-# endif
-# endif
-
- /* TODO: delay this, it can be done in png_init_io (if the app doesn't
- * do it itself) avoiding setting the default function if it is not
- * required.
- */
- png_set_read_fn(png_ptr, NULL, NULL);
- }
-
- return png_ptr;
-}
-
-
-#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
-/* Read the information before the actual image data. This has been
- * changed in v0.90 to allow reading a file that already has the magic
- * bytes read from the stream. You can tell libpng how many bytes have
- * been read from the beginning of the stream (up to the maximum of 8)
- * via png_set_sig_bytes(), and we will only check the remaining bytes
- * here. The application can then have access to the signature bytes we
- * read if it is determined that this isn't a valid PNG file.
- */
-void PNGAPI
-png_read_info(png_structrp png_ptr, png_inforp info_ptr)
-{
-#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
- int keep;
-#endif
-
- png_debug(1, "in png_read_info");
-
- if (png_ptr == NULL || info_ptr == NULL)
- return;
-
- /* Read and check the PNG file signature. */
- png_read_sig(png_ptr, info_ptr);
-
- for (;;)
- {
- png_uint_32 length = png_read_chunk_header(png_ptr);
- png_uint_32 chunk_name = png_ptr->chunk_name;
-
- /* IDAT logic needs to happen here to simplify getting the two flags
- * right.
- */
- if (chunk_name == png_IDAT)
- {
- if (!(png_ptr->mode & PNG_HAVE_IHDR))
- png_chunk_error(png_ptr, "Missing IHDR before IDAT");
-
- else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
- !(png_ptr->mode & PNG_HAVE_PLTE))
- png_chunk_error(png_ptr, "Missing PLTE before IDAT");
-
- else if (png_ptr->mode & PNG_AFTER_IDAT)
- png_chunk_benign_error(png_ptr, "Too many IDATs found");
-
- png_ptr->mode |= PNG_HAVE_IDAT;
- }
-
- else if (png_ptr->mode & PNG_HAVE_IDAT)
- png_ptr->mode |= PNG_AFTER_IDAT;
-
- /* This should be a binary subdivision search or a hash for
- * matching the chunk name rather than a linear search.
- */
- if (chunk_name == png_IHDR)
- png_handle_IHDR(png_ptr, info_ptr, length);
-
- else if (chunk_name == png_IEND)
- png_handle_IEND(png_ptr, info_ptr, length);
-
-#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
- else if ((keep = png_chunk_unknown_handling(png_ptr, chunk_name)) != 0)
- {
- png_handle_unknown(png_ptr, info_ptr, length, keep);
-
- if (chunk_name == png_PLTE)
- png_ptr->mode |= PNG_HAVE_PLTE;
-
- else if (chunk_name == png_IDAT)
- {
- png_ptr->idat_size = 0; /* It has been consumed */
- break;
- }
- }
-#endif
- else if (chunk_name == png_PLTE)
- png_handle_PLTE(png_ptr, info_ptr, length);
-
- else if (chunk_name == png_IDAT)
- {
- png_ptr->idat_size = length;
- break;
- }
-
-#ifdef PNG_READ_bKGD_SUPPORTED
- else if (chunk_name == png_bKGD)
- png_handle_bKGD(png_ptr, info_ptr, length);
-#endif
-
-#ifdef PNG_READ_cHRM_SUPPORTED
- else if (chunk_name == png_cHRM)
- png_handle_cHRM(png_ptr, info_ptr, length);
-#endif
-
-#ifdef PNG_READ_gAMA_SUPPORTED
- else if (chunk_name == png_gAMA)
- png_handle_gAMA(png_ptr, info_ptr, length);
-#endif
-
-#ifdef PNG_READ_hIST_SUPPORTED
- else if (chunk_name == png_hIST)
- png_handle_hIST(png_ptr, info_ptr, length);
-#endif
-
-#ifdef PNG_READ_oFFs_SUPPORTED
- else if (chunk_name == png_oFFs)
- png_handle_oFFs(png_ptr, info_ptr, length);
-#endif
-
-#ifdef PNG_READ_pCAL_SUPPORTED
- else if (chunk_name == png_pCAL)
- png_handle_pCAL(png_ptr, info_ptr, length);
-#endif
-
-#ifdef PNG_READ_sCAL_SUPPORTED
- else if (chunk_name == png_sCAL)
- png_handle_sCAL(png_ptr, info_ptr, length);
-#endif
-
-#ifdef PNG_READ_pHYs_SUPPORTED
- else if (chunk_name == png_pHYs)
- png_handle_pHYs(png_ptr, info_ptr, length);
-#endif
-
-#ifdef PNG_READ_sBIT_SUPPORTED
- else if (chunk_name == png_sBIT)
- png_handle_sBIT(png_ptr, info_ptr, length);
-#endif
-
-#ifdef PNG_READ_sRGB_SUPPORTED
- else if (chunk_name == png_sRGB)
- png_handle_sRGB(png_ptr, info_ptr, length);
-#endif
-
-#ifdef PNG_READ_iCCP_SUPPORTED
- else if (chunk_name == png_iCCP)
- png_handle_iCCP(png_ptr, info_ptr, length);
-#endif
-
-#ifdef PNG_READ_sPLT_SUPPORTED
- else if (chunk_name == png_sPLT)
- png_handle_sPLT(png_ptr, info_ptr, length);
-#endif
-
-#ifdef PNG_READ_tEXt_SUPPORTED
- else if (chunk_name == png_tEXt)
- png_handle_tEXt(png_ptr, info_ptr, length);
-#endif
-
-#ifdef PNG_READ_tIME_SUPPORTED
- else if (chunk_name == png_tIME)
- png_handle_tIME(png_ptr, info_ptr, length);
-#endif
-
-#ifdef PNG_READ_tRNS_SUPPORTED
- else if (chunk_name == png_tRNS)
- png_handle_tRNS(png_ptr, info_ptr, length);
-#endif
-
-#ifdef PNG_READ_zTXt_SUPPORTED
- else if (chunk_name == png_zTXt)
- png_handle_zTXt(png_ptr, info_ptr, length);
-#endif
-
-#ifdef PNG_READ_iTXt_SUPPORTED
- else if (chunk_name == png_iTXt)
- png_handle_iTXt(png_ptr, info_ptr, length);
-#endif
-
- else
- png_handle_unknown(png_ptr, info_ptr, length,
- PNG_HANDLE_CHUNK_AS_DEFAULT);
- }
-}
-#endif /* PNG_SEQUENTIAL_READ_SUPPORTED */
-
-/* Optional call to update the users info_ptr structure */
-void PNGAPI
-png_read_update_info(png_structrp png_ptr, png_inforp info_ptr)
-{
- png_debug(1, "in png_read_update_info");
-
- if (png_ptr != NULL)
- {
- if ((png_ptr->flags & PNG_FLAG_ROW_INIT) == 0)
- {
- png_read_start_row(png_ptr);
-
-# ifdef PNG_READ_TRANSFORMS_SUPPORTED
- png_read_transform_info(png_ptr, info_ptr);
-# else
- PNG_UNUSED(info_ptr)
-# endif
- }
-
- /* New in 1.6.0 this avoids the bug of doing the initializations twice */
- else
- png_app_error(png_ptr,
- "png_read_update_info/png_start_read_image: duplicate call");
- }
-}
-
-#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
-/* Initialize palette, background, etc, after transformations
- * are set, but before any reading takes place. This allows
- * the user to obtain a gamma-corrected palette, for example.
- * If the user doesn't call this, we will do it ourselves.
- */
-void PNGAPI
-png_start_read_image(png_structrp png_ptr)
-{
- png_debug(1, "in png_start_read_image");
-
- if (png_ptr != NULL)
- {
- if ((png_ptr->flags & PNG_FLAG_ROW_INIT) == 0)
- png_read_start_row(png_ptr);
-
- /* New in 1.6.0 this avoids the bug of doing the initializations twice */
- else
- png_app_error(png_ptr,
- "png_start_read_image/png_read_update_info: duplicate call");
- }
-}
-#endif /* PNG_SEQUENTIAL_READ_SUPPORTED */
-
-#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
-void PNGAPI
-png_read_row(png_structrp png_ptr, png_bytep row, png_bytep dsp_row)
-{
- png_row_info row_info;
-
- if (png_ptr == NULL)
- return;
-
- png_debug2(1, "in png_read_row (row %lu, pass %d)",
- (unsigned long)png_ptr->row_number, png_ptr->pass);
-
- /* png_read_start_row sets the information (in particular iwidth) for this
- * interlace pass.
- */
- if (!(png_ptr->flags & PNG_FLAG_ROW_INIT))
- png_read_start_row(png_ptr);
-
- /* 1.5.6: row_info moved out of png_struct to a local here. */
- row_info.width = png_ptr->iwidth; /* NOTE: width of current interlaced row */
- row_info.color_type = png_ptr->color_type;
- row_info.bit_depth = png_ptr->bit_depth;
- row_info.channels = png_ptr->channels;
- row_info.pixel_depth = png_ptr->pixel_depth;
- row_info.rowbytes = PNG_ROWBYTES(row_info.pixel_depth, row_info.width);
-
- if (png_ptr->row_number == 0 && png_ptr->pass == 0)
- {
- /* Check for transforms that have been set but were defined out */
-#if defined(PNG_WRITE_INVERT_SUPPORTED) && !defined(PNG_READ_INVERT_SUPPORTED)
- if (png_ptr->transformations & PNG_INVERT_MONO)
- png_warning(png_ptr, "PNG_READ_INVERT_SUPPORTED is not defined");
-#endif
-
-#if defined(PNG_WRITE_FILLER_SUPPORTED) && !defined(PNG_READ_FILLER_SUPPORTED)
- if (png_ptr->transformations & PNG_FILLER)
- png_warning(png_ptr, "PNG_READ_FILLER_SUPPORTED is not defined");
-#endif
-
-#if defined(PNG_WRITE_PACKSWAP_SUPPORTED) && \
- !defined(PNG_READ_PACKSWAP_SUPPORTED)
- if (png_ptr->transformations & PNG_PACKSWAP)
- png_warning(png_ptr, "PNG_READ_PACKSWAP_SUPPORTED is not defined");
-#endif
-
-#if defined(PNG_WRITE_PACK_SUPPORTED) && !defined(PNG_READ_PACK_SUPPORTED)
- if (png_ptr->transformations & PNG_PACK)
- png_warning(png_ptr, "PNG_READ_PACK_SUPPORTED is not defined");
-#endif
-
-#if defined(PNG_WRITE_SHIFT_SUPPORTED) && !defined(PNG_READ_SHIFT_SUPPORTED)
- if (png_ptr->transformations & PNG_SHIFT)
- png_warning(png_ptr, "PNG_READ_SHIFT_SUPPORTED is not defined");
-#endif
-
-#if defined(PNG_WRITE_BGR_SUPPORTED) && !defined(PNG_READ_BGR_SUPPORTED)
- if (png_ptr->transformations & PNG_BGR)
- png_warning(png_ptr, "PNG_READ_BGR_SUPPORTED is not defined");
-#endif
-
-#if defined(PNG_WRITE_SWAP_SUPPORTED) && !defined(PNG_READ_SWAP_SUPPORTED)
- if (png_ptr->transformations & PNG_SWAP_BYTES)
- png_warning(png_ptr, "PNG_READ_SWAP_SUPPORTED is not defined");
-#endif
- }
-
-#ifdef PNG_READ_INTERLACING_SUPPORTED
- /* If interlaced and we do not need a new row, combine row and return.
- * Notice that the pixels we have from previous rows have been transformed
- * already; we can only combine like with like (transformed or
- * untransformed) and, because of the libpng API for interlaced images, this
- * means we must transform before de-interlacing.
- */
- if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE))
- {
- switch (png_ptr->pass)
- {
- case 0:
- if (png_ptr->row_number & 0x07)
- {
- if (dsp_row != NULL)
- png_combine_row(png_ptr, dsp_row, 1/*display*/);
- png_read_finish_row(png_ptr);
- return;
- }
- break;
-
- case 1:
- if ((png_ptr->row_number & 0x07) || png_ptr->width < 5)
- {
- if (dsp_row != NULL)
- png_combine_row(png_ptr, dsp_row, 1/*display*/);
-
- png_read_finish_row(png_ptr);
- return;
- }
- break;
-
- case 2:
- if ((png_ptr->row_number & 0x07) != 4)
- {
- if (dsp_row != NULL && (png_ptr->row_number & 4))
- png_combine_row(png_ptr, dsp_row, 1/*display*/);
-
- png_read_finish_row(png_ptr);
- return;
- }
- break;
-
- case 3:
- if ((png_ptr->row_number & 3) || png_ptr->width < 3)
- {
- if (dsp_row != NULL)
- png_combine_row(png_ptr, dsp_row, 1/*display*/);
-
- png_read_finish_row(png_ptr);
- return;
- }
- break;
-
- case 4:
- if ((png_ptr->row_number & 3) != 2)
- {
- if (dsp_row != NULL && (png_ptr->row_number & 2))
- png_combine_row(png_ptr, dsp_row, 1/*display*/);
-
- png_read_finish_row(png_ptr);
- return;
- }
- break;
-
- case 5:
- if ((png_ptr->row_number & 1) || png_ptr->width < 2)
- {
- if (dsp_row != NULL)
- png_combine_row(png_ptr, dsp_row, 1/*display*/);
-
- png_read_finish_row(png_ptr);
- return;
- }
- break;
-
- default:
- case 6:
- if (!(png_ptr->row_number & 1))
- {
- png_read_finish_row(png_ptr);
- return;
- }
- break;
- }
- }
-#endif
-
- if (!(png_ptr->mode & PNG_HAVE_IDAT))
- png_error(png_ptr, "Invalid attempt to read row data");
-
- /* Fill the row with IDAT data: */
- png_read_IDAT_data(png_ptr, png_ptr->row_buf, row_info.rowbytes + 1);
-
- if (png_ptr->row_buf[0] > PNG_FILTER_VALUE_NONE)
- {
- if (png_ptr->row_buf[0] < PNG_FILTER_VALUE_LAST)
- png_read_filter_row(png_ptr, &row_info, png_ptr->row_buf + 1,
- png_ptr->prev_row + 1, png_ptr->row_buf[0]);
- else
- png_error(png_ptr, "bad adaptive filter value");
- }
-
- /* libpng 1.5.6: the following line was copying png_ptr->rowbytes before
- * 1.5.6, while the buffer really is this big in current versions of libpng
- * it may not be in the future, so this was changed just to copy the
- * interlaced count:
- */
- memcpy(png_ptr->prev_row, png_ptr->row_buf, row_info.rowbytes + 1);
-
-#ifdef PNG_MNG_FEATURES_SUPPORTED
- if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
- (png_ptr->filter_type == PNG_INTRAPIXEL_DIFFERENCING))
- {
- /* Intrapixel differencing */
- png_do_read_intrapixel(&row_info, png_ptr->row_buf + 1);
- }
-#endif
-
-
-#ifdef PNG_READ_TRANSFORMS_SUPPORTED
- if (png_ptr->transformations)
- png_do_read_transformations(png_ptr, &row_info);
-#endif
-
- /* The transformed pixel depth should match the depth now in row_info. */
- if (png_ptr->transformed_pixel_depth == 0)
- {
- png_ptr->transformed_pixel_depth = row_info.pixel_depth;
- if (row_info.pixel_depth > png_ptr->maximum_pixel_depth)
- png_error(png_ptr, "sequential row overflow");
- }
-
- else if (png_ptr->transformed_pixel_depth != row_info.pixel_depth)
- png_error(png_ptr, "internal sequential row size calculation error");
-
-#ifdef PNG_READ_INTERLACING_SUPPORTED
- /* Blow up interlaced rows to full size */
- if (png_ptr->interlaced &&
- (png_ptr->transformations & PNG_INTERLACE))
- {
- if (png_ptr->pass < 6)
- png_do_read_interlace(&row_info, png_ptr->row_buf + 1, png_ptr->pass,
- png_ptr->transformations);
-
- if (dsp_row != NULL)
- png_combine_row(png_ptr, dsp_row, 1/*display*/);
-
- if (row != NULL)
- png_combine_row(png_ptr, row, 0/*row*/);
- }
-
- else
-#endif
- {
- if (row != NULL)
- png_combine_row(png_ptr, row, -1/*ignored*/);
-
- if (dsp_row != NULL)
- png_combine_row(png_ptr, dsp_row, -1/*ignored*/);
- }
- png_read_finish_row(png_ptr);
-
- if (png_ptr->read_row_fn != NULL)
- (*(png_ptr->read_row_fn))(png_ptr, png_ptr->row_number, png_ptr->pass);
-
-}
-#endif /* PNG_SEQUENTIAL_READ_SUPPORTED */
-
-#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
-/* Read one or more rows of image data. If the image is interlaced,
- * and png_set_interlace_handling() has been called, the rows need to
- * contain the contents of the rows from the previous pass. If the
- * image has alpha or transparency, and png_handle_alpha()[*] has been
- * called, the rows contents must be initialized to the contents of the
- * screen.
- *
- * "row" holds the actual image, and pixels are placed in it
- * as they arrive. If the image is displayed after each pass, it will
- * appear to "sparkle" in. "display_row" can be used to display a
- * "chunky" progressive image, with finer detail added as it becomes
- * available. If you do not want this "chunky" display, you may pass
- * NULL for display_row. If you do not want the sparkle display, and
- * you have not called png_handle_alpha(), you may pass NULL for rows.
- * If you have called png_handle_alpha(), and the image has either an
- * alpha channel or a transparency chunk, you must provide a buffer for
- * rows. In this case, you do not have to provide a display_row buffer
- * also, but you may. If the image is not interlaced, or if you have
- * not called png_set_interlace_handling(), the display_row buffer will
- * be ignored, so pass NULL to it.
- *
- * [*] png_handle_alpha() does not exist yet, as of this version of libpng
- */
-
-void PNGAPI
-png_read_rows(png_structrp png_ptr, png_bytepp row,
- png_bytepp display_row, png_uint_32 num_rows)
-{
- png_uint_32 i;
- png_bytepp rp;
- png_bytepp dp;
-
- png_debug(1, "in png_read_rows");
-
- if (png_ptr == NULL)
- return;
-
- rp = row;
- dp = display_row;
- if (rp != NULL && dp != NULL)
- for (i = 0; i < num_rows; i++)
- {
- png_bytep rptr = *rp++;
- png_bytep dptr = *dp++;
-
- png_read_row(png_ptr, rptr, dptr);
- }
-
- else if (rp != NULL)
- for (i = 0; i < num_rows; i++)
- {
- png_bytep rptr = *rp;
- png_read_row(png_ptr, rptr, NULL);
- rp++;
- }
-
- else if (dp != NULL)
- for (i = 0; i < num_rows; i++)
- {
- png_bytep dptr = *dp;
- png_read_row(png_ptr, NULL, dptr);
- dp++;
- }
-}
-#endif /* PNG_SEQUENTIAL_READ_SUPPORTED */
-
-#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
-/* Read the entire image. If the image has an alpha channel or a tRNS
- * chunk, and you have called png_handle_alpha()[*], you will need to
- * initialize the image to the current image that PNG will be overlaying.
- * We set the num_rows again here, in case it was incorrectly set in
- * png_read_start_row() by a call to png_read_update_info() or
- * png_start_read_image() if png_set_interlace_handling() wasn't called
- * prior to either of these functions like it should have been. You can
- * only call this function once. If you desire to have an image for
- * each pass of a interlaced image, use png_read_rows() instead.
- *
- * [*] png_handle_alpha() does not exist yet, as of this version of libpng
- */
-void PNGAPI
-png_read_image(png_structrp png_ptr, png_bytepp image)
-{
- png_uint_32 i, image_height;
- int pass, j;
- png_bytepp rp;
-
- png_debug(1, "in png_read_image");
-
- if (png_ptr == NULL)
- return;
-
-#ifdef PNG_READ_INTERLACING_SUPPORTED
- if (!(png_ptr->flags & PNG_FLAG_ROW_INIT))
- {
- pass = png_set_interlace_handling(png_ptr);
- /* And make sure transforms are initialized. */
- png_start_read_image(png_ptr);
- }
- else
- {
- if (png_ptr->interlaced && !(png_ptr->transformations & PNG_INTERLACE))
- {
- /* Caller called png_start_read_image or png_read_update_info without
- * first turning on the PNG_INTERLACE transform. We can fix this here,
- * but the caller should do it!
- */
- png_warning(png_ptr, "Interlace handling should be turned on when "
- "using png_read_image");
- /* Make sure this is set correctly */
- png_ptr->num_rows = png_ptr->height;
- }
-
- /* Obtain the pass number, which also turns on the PNG_INTERLACE flag in
- * the above error case.
- */
- pass = png_set_interlace_handling(png_ptr);
- }
-#else
- if (png_ptr->interlaced)
- png_error(png_ptr,
- "Cannot read interlaced image -- interlace handler disabled");
-
- pass = 1;
-#endif
-
- image_height=png_ptr->height;
-
- for (j = 0; j < pass; j++)
- {
- rp = image;
- for (i = 0; i < image_height; i++)
- {
- png_read_row(png_ptr, *rp, NULL);
- rp++;
- }
- }
-}
-#endif /* PNG_SEQUENTIAL_READ_SUPPORTED */
-
-#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
-/* Read the end of the PNG file. Will not read past the end of the
- * file, will verify the end is accurate, and will read any comments
- * or time information at the end of the file, if info is not NULL.
- */
-void PNGAPI
-png_read_end(png_structrp png_ptr, png_inforp info_ptr)
-{
-#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
- int keep;
-#endif
-
- png_debug(1, "in png_read_end");
-
- if (png_ptr == NULL)
- return;
-
- /* If png_read_end is called in the middle of reading the rows there may
- * still be pending IDAT data and an owned zstream. Deal with this here.
- */
-#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
- if (!png_chunk_unknown_handling(png_ptr, png_IDAT))
-#endif
- png_read_finish_IDAT(png_ptr);
-
-#ifdef PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED
- /* Report invalid palette index; added at libng-1.5.10 */
- if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
- png_ptr->num_palette_max > png_ptr->num_palette)
- png_benign_error(png_ptr, "Read palette index exceeding num_palette");
-#endif
-
- do
- {
- png_uint_32 length = png_read_chunk_header(png_ptr);
- png_uint_32 chunk_name = png_ptr->chunk_name;
-
- if (chunk_name == png_IHDR)
- png_handle_IHDR(png_ptr, info_ptr, length);
-
- else if (chunk_name == png_IEND)
- png_handle_IEND(png_ptr, info_ptr, length);
-
-#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
- else if ((keep = png_chunk_unknown_handling(png_ptr, chunk_name)) != 0)
- {
- if (chunk_name == png_IDAT)
- {
- if ((length > 0) || (png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT))
- png_benign_error(png_ptr, "Too many IDATs found");
- }
- png_handle_unknown(png_ptr, info_ptr, length, keep);
- if (chunk_name == png_PLTE)
- png_ptr->mode |= PNG_HAVE_PLTE;
- }
-#endif
-
- else if (chunk_name == png_IDAT)
- {
- /* Zero length IDATs are legal after the last IDAT has been
- * read, but not after other chunks have been read.
- */
- if ((length > 0) || (png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT))
- png_benign_error(png_ptr, "Too many IDATs found");
-
- png_crc_finish(png_ptr, length);
- }
- else if (chunk_name == png_PLTE)
- png_handle_PLTE(png_ptr, info_ptr, length);
-
-#ifdef PNG_READ_bKGD_SUPPORTED
- else if (chunk_name == png_bKGD)
- png_handle_bKGD(png_ptr, info_ptr, length);
-#endif
-
-#ifdef PNG_READ_cHRM_SUPPORTED
- else if (chunk_name == png_cHRM)
- png_handle_cHRM(png_ptr, info_ptr, length);
-#endif
-
-#ifdef PNG_READ_gAMA_SUPPORTED
- else if (chunk_name == png_gAMA)
- png_handle_gAMA(png_ptr, info_ptr, length);
-#endif
-
-#ifdef PNG_READ_hIST_SUPPORTED
- else if (chunk_name == png_hIST)
- png_handle_hIST(png_ptr, info_ptr, length);
-#endif
-
-#ifdef PNG_READ_oFFs_SUPPORTED
- else if (chunk_name == png_oFFs)
- png_handle_oFFs(png_ptr, info_ptr, length);
-#endif
-
-#ifdef PNG_READ_pCAL_SUPPORTED
- else if (chunk_name == png_pCAL)
- png_handle_pCAL(png_ptr, info_ptr, length);
-#endif
-
-#ifdef PNG_READ_sCAL_SUPPORTED
- else if (chunk_name == png_sCAL)
- png_handle_sCAL(png_ptr, info_ptr, length);
-#endif
-
-#ifdef PNG_READ_pHYs_SUPPORTED
- else if (chunk_name == png_pHYs)
- png_handle_pHYs(png_ptr, info_ptr, length);
-#endif
-
-#ifdef PNG_READ_sBIT_SUPPORTED
- else if (chunk_name == png_sBIT)
- png_handle_sBIT(png_ptr, info_ptr, length);
-#endif
-
-#ifdef PNG_READ_sRGB_SUPPORTED
- else if (chunk_name == png_sRGB)
- png_handle_sRGB(png_ptr, info_ptr, length);
-#endif
-
-#ifdef PNG_READ_iCCP_SUPPORTED
- else if (chunk_name == png_iCCP)
- png_handle_iCCP(png_ptr, info_ptr, length);
-#endif
-
-#ifdef PNG_READ_sPLT_SUPPORTED
- else if (chunk_name == png_sPLT)
- png_handle_sPLT(png_ptr, info_ptr, length);
-#endif
-
-#ifdef PNG_READ_tEXt_SUPPORTED
- else if (chunk_name == png_tEXt)
- png_handle_tEXt(png_ptr, info_ptr, length);
-#endif
-
-#ifdef PNG_READ_tIME_SUPPORTED
- else if (chunk_name == png_tIME)
- png_handle_tIME(png_ptr, info_ptr, length);
-#endif
-
-#ifdef PNG_READ_tRNS_SUPPORTED
- else if (chunk_name == png_tRNS)
- png_handle_tRNS(png_ptr, info_ptr, length);
-#endif
-
-#ifdef PNG_READ_zTXt_SUPPORTED
- else if (chunk_name == png_zTXt)
- png_handle_zTXt(png_ptr, info_ptr, length);
-#endif
-
-#ifdef PNG_READ_iTXt_SUPPORTED
- else if (chunk_name == png_iTXt)
- png_handle_iTXt(png_ptr, info_ptr, length);
-#endif
-
- else
- png_handle_unknown(png_ptr, info_ptr, length,
- PNG_HANDLE_CHUNK_AS_DEFAULT);
- } while (!(png_ptr->mode & PNG_HAVE_IEND));
-}
-#endif /* PNG_SEQUENTIAL_READ_SUPPORTED */
-
-/* Free all memory used in the read struct */
-static void
-png_read_destroy(png_structrp png_ptr)
-{
- png_debug(1, "in png_read_destroy");
-
-#ifdef PNG_READ_GAMMA_SUPPORTED
- png_destroy_gamma_table(png_ptr);
-#endif
-
- png_free(png_ptr, png_ptr->big_row_buf);
- png_free(png_ptr, png_ptr->big_prev_row);
- png_free(png_ptr, png_ptr->read_buffer);
-
-#ifdef PNG_READ_QUANTIZE_SUPPORTED
- png_free(png_ptr, png_ptr->palette_lookup);
- png_free(png_ptr, png_ptr->quantize_index);
-#endif
-
- if (png_ptr->free_me & PNG_FREE_PLTE)
- png_zfree(png_ptr, png_ptr->palette);
- png_ptr->free_me &= ~PNG_FREE_PLTE;
-
-#if defined(PNG_tRNS_SUPPORTED) || \
- defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
- if (png_ptr->free_me & PNG_FREE_TRNS)
- png_free(png_ptr, png_ptr->trans_alpha);
- png_ptr->free_me &= ~PNG_FREE_TRNS;
-#endif
-
- inflateEnd(&png_ptr->zstream);
-
-#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
- png_free(png_ptr, png_ptr->save_buffer);
-#endif
-
-#if defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED) &&\
- defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED)
- png_free(png_ptr, png_ptr->unknown_chunk.data);
-#endif
-
-#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
- png_free(png_ptr, png_ptr->chunk_list);
-#endif
-
- /* NOTE: the 'setjmp' buffer may still be allocated and the memory and error
- * callbacks are still set at this point. They are required to complete the
- * destruction of the png_struct itself.
- */
-}
-
-/* Free all memory used by the read */
-void PNGAPI
-png_destroy_read_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr,
- png_infopp end_info_ptr_ptr)
-{
- png_structrp png_ptr = NULL;
-
- png_debug(1, "in png_destroy_read_struct");
-
- if (png_ptr_ptr != NULL)
- png_ptr = *png_ptr_ptr;
-
- if (png_ptr == NULL)
- return;
-
- /* libpng 1.6.0: use the API to destroy info structs to ensure consistent
- * behavior. Prior to 1.6.0 libpng did extra 'info' destruction in this API.
- * The extra was, apparently, unnecessary yet this hides memory leak bugs.
- */
- png_destroy_info_struct(png_ptr, end_info_ptr_ptr);
- png_destroy_info_struct(png_ptr, info_ptr_ptr);
-
- *png_ptr_ptr = NULL;
- png_read_destroy(png_ptr);
- png_destroy_png_struct(png_ptr);
-}
-
-void PNGAPI
-png_set_read_status_fn(png_structrp png_ptr, png_read_status_ptr read_row_fn)
-{
- if (png_ptr == NULL)
- return;
-
- png_ptr->read_row_fn = read_row_fn;
-}
-
-
-#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
-#ifdef PNG_INFO_IMAGE_SUPPORTED
-void PNGAPI
-png_read_png(png_structrp png_ptr, png_inforp info_ptr,
- int transforms,
- voidp params)
-{
- int row;
-
- if (png_ptr == NULL || info_ptr == NULL)
- return;
-
- /* png_read_info() gives us all of the information from the
- * PNG file before the first IDAT (image data chunk).
- */
- png_read_info(png_ptr, info_ptr);
- if (info_ptr->height > PNG_UINT_32_MAX/(sizeof (png_bytep)))
- png_error(png_ptr, "Image is too high to process with png_read_png()");
-
- /* -------------- image transformations start here ------------------- */
-
-#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
- /* Tell libpng to strip 16-bit/color files down to 8 bits per color.
- */
- if (transforms & PNG_TRANSFORM_SCALE_16)
- {
- /* Added at libpng-1.5.4. "strip_16" produces the same result that it
- * did in earlier versions, while "scale_16" is now more accurate.
- */
- png_set_scale_16(png_ptr);
- }
-#endif
-
-#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
- /* If both SCALE and STRIP are required pngrtran will effectively cancel the
- * latter by doing SCALE first. This is ok and allows apps not to check for
- * which is supported to get the right answer.
- */
- if (transforms & PNG_TRANSFORM_STRIP_16)
- png_set_strip_16(png_ptr);
-#endif
-
-#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
- /* Strip alpha bytes from the input data without combining with
- * the background (not recommended).
- */
- if (transforms & PNG_TRANSFORM_STRIP_ALPHA)
- png_set_strip_alpha(png_ptr);
-#endif
-
-#if defined(PNG_READ_PACK_SUPPORTED) && !defined(PNG_READ_EXPAND_SUPPORTED)
- /* Extract multiple pixels with bit depths of 1, 2, or 4 from a single
- * byte into separate bytes (useful for paletted and grayscale images).
- */
- if (transforms & PNG_TRANSFORM_PACKING)
- png_set_packing(png_ptr);
-#endif
-
-#ifdef PNG_READ_PACKSWAP_SUPPORTED
- /* Change the order of packed pixels to least significant bit first
- * (not useful if you are using png_set_packing).
- */
- if (transforms & PNG_TRANSFORM_PACKSWAP)
- png_set_packswap(png_ptr);
-#endif
-
-#ifdef PNG_READ_EXPAND_SUPPORTED
- /* Expand paletted colors into true RGB triplets
- * Expand grayscale images to full 8 bits from 1, 2, or 4 bits/pixel
- * Expand paletted or RGB images with transparency to full alpha
- * channels so the data will be available as RGBA quartets.
- */
- if (transforms & PNG_TRANSFORM_EXPAND)
- if ((png_ptr->bit_depth < 8) ||
- (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) ||
- (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS)))
- png_set_expand(png_ptr);
-#endif
-
- /* We don't handle background color or gamma transformation or quantizing.
- */
-
-#ifdef PNG_READ_INVERT_SUPPORTED
- /* Invert monochrome files to have 0 as white and 1 as black
- */
- if (transforms & PNG_TRANSFORM_INVERT_MONO)
- png_set_invert_mono(png_ptr);
-#endif
-
-#ifdef PNG_READ_SHIFT_SUPPORTED
- /* If you want to shift the pixel values from the range [0,255] or
- * [0,65535] to the original [0,7] or [0,31], or whatever range the
- * colors were originally in:
- */
- if ((transforms & PNG_TRANSFORM_SHIFT)
- && png_get_valid(png_ptr, info_ptr, PNG_INFO_sBIT))
- {
- png_color_8p sig_bit;
-
- png_get_sBIT(png_ptr, info_ptr, &sig_bit);
- png_set_shift(png_ptr, sig_bit);
- }
-#endif
-
-#ifdef PNG_READ_BGR_SUPPORTED
- /* Flip the RGB pixels to BGR (or RGBA to BGRA) */
- if (transforms & PNG_TRANSFORM_BGR)
- png_set_bgr(png_ptr);
-#endif
-
-#ifdef PNG_READ_SWAP_ALPHA_SUPPORTED
- /* Swap the RGBA or GA data to ARGB or AG (or BGRA to ABGR) */
- if (transforms & PNG_TRANSFORM_SWAP_ALPHA)
- png_set_swap_alpha(png_ptr);
-#endif
-
-#ifdef PNG_READ_SWAP_SUPPORTED
- /* Swap bytes of 16-bit files to least significant byte first */
- if (transforms & PNG_TRANSFORM_SWAP_ENDIAN)
- png_set_swap(png_ptr);
-#endif
-
-/* Added at libpng-1.2.41 */
-#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED
- /* Invert the alpha channel from opacity to transparency */
- if (transforms & PNG_TRANSFORM_INVERT_ALPHA)
- png_set_invert_alpha(png_ptr);
-#endif
-
-/* Added at libpng-1.2.41 */
-#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
- /* Expand grayscale image to RGB */
- if (transforms & PNG_TRANSFORM_GRAY_TO_RGB)
- png_set_gray_to_rgb(png_ptr);
-#endif
-
-/* Added at libpng-1.5.4 */
-#ifdef PNG_READ_EXPAND_16_SUPPORTED
- if (transforms & PNG_TRANSFORM_EXPAND_16)
- png_set_expand_16(png_ptr);
-#endif
-
- /* We don't handle adding filler bytes */
-
- /* We use png_read_image and rely on that for interlace handling, but we also
- * call png_read_update_info therefore must turn on interlace handling now:
- */
- (void)png_set_interlace_handling(png_ptr);
-
- /* Optional call to gamma correct and add the background to the palette
- * and update info structure. REQUIRED if you are expecting libpng to
- * update the palette for you (i.e., you selected such a transform above).
- */
- png_read_update_info(png_ptr, info_ptr);
-
- /* -------------- image transformations end here ------------------- */
-
- png_free_data(png_ptr, info_ptr, PNG_FREE_ROWS, 0);
- if (info_ptr->row_pointers == NULL)
- {
- png_uint_32 iptr;
-
- info_ptr->row_pointers = (png_bytepp)png_malloc(png_ptr,
- info_ptr->height * (sizeof (png_bytep)));
- for (iptr=0; iptr<info_ptr->height; iptr++)
- info_ptr->row_pointers[iptr] = NULL;
-
- info_ptr->free_me |= PNG_FREE_ROWS;
-
- for (row = 0; row < (int)info_ptr->height; row++)
- info_ptr->row_pointers[row] = (png_bytep)png_malloc(png_ptr,
- png_get_rowbytes(png_ptr, info_ptr));
- }
-
- png_read_image(png_ptr, info_ptr->row_pointers);
- info_ptr->valid |= PNG_INFO_IDAT;
-
- /* Read rest of file, and get additional chunks in info_ptr - REQUIRED */
- png_read_end(png_ptr, info_ptr);
-
- PNG_UNUSED(transforms) /* Quiet compiler warnings */
- PNG_UNUSED(params)
-
-}
-#endif /* PNG_INFO_IMAGE_SUPPORTED */
-#endif /* PNG_SEQUENTIAL_READ_SUPPORTED */
-
-#ifdef PNG_SIMPLIFIED_READ_SUPPORTED
-/* SIMPLIFIED READ
- *
- * This code currently relies on the sequential reader, though it could easily
- * be made to work with the progressive one.
- */
-/* Arguments to png_image_finish_read: */
-
-/* Encoding of PNG data (used by the color-map code) */
-/* TODO: change these, dang, ANSI-C reserves the 'E' namespace. */
-# define E_NOTSET 0 /* File encoding not yet known */
-# define E_sRGB 1 /* 8-bit encoded to sRGB gamma */
-# define E_LINEAR 2 /* 16-bit linear: not encoded, NOT pre-multiplied! */
-# define E_FILE 3 /* 8-bit encoded to file gamma, not sRGB or linear */
-# define E_LINEAR8 4 /* 8-bit linear: only from a file value */
-
-/* Color-map processing: after libpng has run on the PNG image further
- * processing may be needed to conver the data to color-map indicies.
- */
-#define PNG_CMAP_NONE 0
-#define PNG_CMAP_GA 1 /* Process GA data to a color-map with alpha */
-#define PNG_CMAP_TRANS 2 /* Process GA data to a background index */
-#define PNG_CMAP_RGB 3 /* Process RGB data */
-#define PNG_CMAP_RGB_ALPHA 4 /* Process RGBA data */
-
-/* The following document where the background is for each processing case. */
-#define PNG_CMAP_NONE_BACKGROUND 256
-#define PNG_CMAP_GA_BACKGROUND 231
-#define PNG_CMAP_TRANS_BACKGROUND 254
-#define PNG_CMAP_RGB_BACKGROUND 256
-#define PNG_CMAP_RGB_ALPHA_BACKGROUND 216
-
-typedef struct
-{
- /* Arguments: */
- png_imagep image;
- png_voidp buffer;
- png_int_32 row_stride;
- png_voidp colormap;
- png_const_colorp background;
- /* Local variables: */
- png_voidp local_row;
- png_voidp first_row;
- ptrdiff_t row_bytes; /* step between rows */
- int file_encoding; /* E_ values above */
- png_fixed_point gamma_to_linear; /* For E_FILE, reciprocal of gamma */
- int colormap_processing; /* PNG_CMAP_ values above */
-} png_image_read_control;
-
-/* Do all the *safe* initialization - 'safe' means that png_error won't be
- * called, so setting up the jmp_buf is not required. This means that anything
- * called from here must *not* call png_malloc - it has to call png_malloc_warn
- * instead so that control is returned safely back to this routine.
- */
-static int
-png_image_read_init(png_imagep image)
-{
- if (image->opaque == NULL)
- {
- png_structp png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, image,
- png_safe_error, png_safe_warning);
-
- /* And set the rest of the structure to NULL to ensure that the various
- * fields are consistent.
- */
- memset(image, 0, (sizeof *image));
- image->version = PNG_IMAGE_VERSION;
-
- if (png_ptr != NULL)
- {
- png_infop info_ptr = png_create_info_struct(png_ptr);
-
- if (info_ptr != NULL)
- {
- png_controlp control = png_voidcast(png_controlp,
- png_malloc_warn(png_ptr, (sizeof *control)));
-
- if (control != NULL)
- {
- memset(control, 0, (sizeof *control));
-
- control->png_ptr = png_ptr;
- control->info_ptr = info_ptr;
- control->for_write = 0;
-
- image->opaque = control;
- return 1;
- }
-
- /* Error clean up */
- png_destroy_info_struct(png_ptr, &info_ptr);
- }
-
- png_destroy_read_struct(&png_ptr, NULL, NULL);
- }
-
- return png_image_error(image, "png_image_read: out of memory");
- }
-
- return png_image_error(image, "png_image_read: opaque pointer not NULL");
-}
-
-/* Utility to find the base format of a PNG file from a png_struct. */
-static png_uint_32
-png_image_format(png_structrp png_ptr)
-{
- png_uint_32 format = 0;
-
- if (png_ptr->color_type & PNG_COLOR_MASK_COLOR)
- format |= PNG_FORMAT_FLAG_COLOR;
-
- if (png_ptr->color_type & PNG_COLOR_MASK_ALPHA)
- format |= PNG_FORMAT_FLAG_ALPHA;
-
- /* Use png_ptr here, not info_ptr, because by examination png_handle_tRNS
- * sets the png_struct fields; that's all we are interested in here. The
- * precise interaction with an app call to png_set_tRNS and PNG file reading
- * is unclear.
- */
- else if (png_ptr->num_trans > 0)
- format |= PNG_FORMAT_FLAG_ALPHA;
-
- if (png_ptr->bit_depth == 16)
- format |= PNG_FORMAT_FLAG_LINEAR;
-
- if (png_ptr->color_type & PNG_COLOR_MASK_PALETTE)
- format |= PNG_FORMAT_FLAG_COLORMAP;
-
- return format;
-}
-
-/* Is the given gamma significantly different from sRGB? The test is the same
- * one used in pngrtran.c when deciding whether to do gamma correction. The
- * arithmetic optimizes the division by using the fact that the inverse of the
- * file sRGB gamma is 2.2
- */
-static int
-png_gamma_not_sRGB(png_fixed_point g)
-{
- if (g < PNG_FP_1)
- {
- /* An uninitialized gamma is assumed to be sRGB for the simplified API. */
- if (g == 0)
- return 0;
-
- return png_gamma_significant((g * 11 + 2)/5 /* i.e. *2.2, rounded */);
- }
-
- return 1;
-}
-
-/* Do the main body of a 'png_image_begin_read' function; read the PNG file
- * header and fill in all the information. This is executed in a safe context,
- * unlike the init routine above.
- */
-static int
-png_image_read_header(png_voidp argument)
-{
- png_imagep image = png_voidcast(png_imagep, argument);
- png_structrp png_ptr = image->opaque->png_ptr;
- png_inforp info_ptr = image->opaque->info_ptr;
-
- png_set_benign_errors(png_ptr, 1/*warn*/);
- png_read_info(png_ptr, info_ptr);
-
- /* Do this the fast way; just read directly out of png_struct. */
- image->width = png_ptr->width;
- image->height = png_ptr->height;
-
- {
- png_uint_32 format = png_image_format(png_ptr);
-
- image->format = format;
-
-#ifdef PNG_COLORSPACE_SUPPORTED
- /* Does the colorspace match sRGB? If there is no color endpoint
- * (colorant) information assume yes, otherwise require the
- * 'ENDPOINTS_MATCHE_sRGB' colorspace flag to have been set. If the
- * colorspace has been determined to be invalid ignore it.
- */
- if ((format & PNG_FORMAT_FLAG_COLOR) != 0 && ((png_ptr->colorspace.flags
- & (PNG_COLORSPACE_HAVE_ENDPOINTS|PNG_COLORSPACE_ENDPOINTS_MATCH_sRGB|
- PNG_COLORSPACE_INVALID)) == PNG_COLORSPACE_HAVE_ENDPOINTS))
- image->flags |= PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB;
-#endif
- }
-
- /* We need the maximum number of entries regardless of the format the
- * application sets here.
- */
- {
- png_uint_32 cmap_entries;
-
- switch (png_ptr->color_type)
- {
- case PNG_COLOR_TYPE_GRAY:
- cmap_entries = 1U << png_ptr->bit_depth;
- break;
-
- case PNG_COLOR_TYPE_PALETTE:
- cmap_entries = png_ptr->num_palette;
- break;
-
- default:
- cmap_entries = 256;
- break;
- }
-
- if (cmap_entries > 256)
- cmap_entries = 256;
-
- image->colormap_entries = cmap_entries;
- }
-
- return 1;
-}
-
-#ifdef PNG_STDIO_SUPPORTED
-int PNGAPI
-png_image_begin_read_from_stdio(png_imagep image, FILE* file)
-{
- if (image != NULL && image->version == PNG_IMAGE_VERSION)
- {
- if (file != NULL)
- {
- if (png_image_read_init(image))
- {
- /* This is slightly evil, but png_init_io doesn't do anything other
- * than this and we haven't changed the standard IO functions so
- * this saves a 'safe' function.
- */
- image->opaque->png_ptr->io_ptr = file;
- return png_safe_execute(image, png_image_read_header, image);
- }
- }
-
- else
- return png_image_error(image,
- "png_image_begin_read_from_stdio: invalid argument");
- }
-
- else if (image != NULL)
- return png_image_error(image,
- "png_image_begin_read_from_stdio: incorrect PNG_IMAGE_VERSION");
-
- return 0;
-}
-
-int PNGAPI
-png_image_begin_read_from_file(png_imagep image, const char *file_name)
-{
- if (image != NULL && image->version == PNG_IMAGE_VERSION)
- {
- if (file_name != NULL)
- {
- FILE *fp = fopen(file_name, "rb");
-
- if (fp != NULL)
- {
- if (png_image_read_init(image))
- {
- image->opaque->png_ptr->io_ptr = fp;
- image->opaque->owned_file = 1;
- return png_safe_execute(image, png_image_read_header, image);
- }
-
- /* Clean up: just the opened file. */
- (void)fclose(fp);
- }
-
- else
- return png_image_error(image, strerror(errno));
- }
-
- else
- return png_image_error(image,
- "png_image_begin_read_from_file: invalid argument");
- }
-
- else if (image != NULL)
- return png_image_error(image,
- "png_image_begin_read_from_file: incorrect PNG_IMAGE_VERSION");
-
- return 0;
-}
-#endif /* PNG_STDIO_SUPPORTED */
-
-static void PNGCBAPI
-png_image_memory_read(png_structp png_ptr, png_bytep out, png_size_t need)
-{
- if (png_ptr != NULL)
- {
- png_imagep image = png_voidcast(png_imagep, png_ptr->io_ptr);
- if (image != NULL)
- {
- png_controlp cp = image->opaque;
- if (cp != NULL)
- {
- png_const_bytep memory = cp->memory;
- png_size_t size = cp->size;
-
- if (memory != NULL && size >= need)
- {
- memcpy(out, memory, need);
- cp->memory = memory + need;
- cp->size = size - need;
- return;
- }
-
- png_error(png_ptr, "read beyond end of data");
- }
- }
-
- png_error(png_ptr, "invalid memory read");
- }
-}
-
-int PNGAPI png_image_begin_read_from_memory(png_imagep image,
- png_const_voidp memory, png_size_t size)
-{
- if (image != NULL && image->version == PNG_IMAGE_VERSION)
- {
- if (memory != NULL && size > 0)
- {
- if (png_image_read_init(image))
- {
- /* Now set the IO functions to read from the memory buffer and
- * store it into io_ptr. Again do this in-place to avoid calling a
- * libpng function that requires error handling.
- */
- image->opaque->memory = png_voidcast(png_const_bytep, memory);
- image->opaque->size = size;
- image->opaque->png_ptr->io_ptr = image;
- image->opaque->png_ptr->read_data_fn = png_image_memory_read;
-
- return png_safe_execute(image, png_image_read_header, image);
- }
- }
-
- else
- return png_image_error(image,
- "png_image_begin_read_from_memory: invalid argument");
- }
-
- else if (image != NULL)
- return png_image_error(image,
- "png_image_begin_read_from_memory: incorrect PNG_IMAGE_VERSION");
-
- return 0;
-}
-
-/* Utility function to skip chunks that are not used by the simplified image
- * read functions and an appropriate macro to call it.
- */
-#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
-static void
-png_image_skip_unused_chunks(png_structrp png_ptr)
-{
- /* Prepare the reader to ignore all recognized chunks whose data will not
- * be used, i.e., all chunks recognized by libpng except for those
- * involved in basic image reading:
- *
- * IHDR, PLTE, IDAT, IEND
- *
- * Or image data handling:
- *
- * tRNS, bKGD, gAMA, cHRM, sRGB, iCCP and sBIT.
- *
- * This provides a small performance improvement and eliminates any
- * potential vulnerability to security problems in the unused chunks.
- */
- {
- static PNG_CONST png_byte chunks_to_process[] = {
- 98, 75, 71, 68, '\0', /* bKGD */
- 99, 72, 82, 77, '\0', /* cHRM */
- 103, 65, 77, 65, '\0', /* gAMA */
- 105, 67, 67, 80, '\0', /* iCCP */
- 115, 66, 73, 84, '\0', /* sBIT */
- 115, 82, 71, 66, '\0', /* sRGB */
- };
-
- /* Ignore unknown chunks and all other chunks except for the
- * IHDR, PLTE, tRNS, IDAT, and IEND chunks.
- */
- png_set_keep_unknown_chunks(png_ptr, PNG_HANDLE_CHUNK_NEVER,
- NULL, -1);
-
- /* But do not ignore image data handling chunks */
- png_set_keep_unknown_chunks(png_ptr, PNG_HANDLE_CHUNK_AS_DEFAULT,
- chunks_to_process, (sizeof chunks_to_process)/5);
- }
-}
-
-# define PNG_SKIP_CHUNKS(p) png_image_skip_unused_chunks(p)
-#else
-# define PNG_SKIP_CHUNKS(p) ((void)0)
-#endif /* PNG_HANDLE_AS_UNKNOWN_SUPPORTED */
-
-/* The following macro gives the exact rounded answer for all values in the
- * range 0..255 (it actually divides by 51.2, but the rounding still generates
- * the correct numbers 0..5
- */
-#define PNG_DIV51(v8) (((v8) * 5 + 130) >> 8)
-
-/* Utility functions to make particular color-maps */
-static void
-set_file_encoding(png_image_read_control *display)
-{
- png_fixed_point g = display->image->opaque->png_ptr->colorspace.gamma;
- if (png_gamma_significant(g))
- {
- if (png_gamma_not_sRGB(g))
- {
- display->file_encoding = E_FILE;
- display->gamma_to_linear = png_reciprocal(g);
- }
-
- else
- display->file_encoding = E_sRGB;
- }
-
- else
- display->file_encoding = E_LINEAR8;
-}
-
-static unsigned int
-decode_gamma(png_image_read_control *display, png_uint_32 value, int encoding)
-{
- if (encoding == E_FILE) /* double check */
- encoding = display->file_encoding;
-
- if (encoding == E_NOTSET) /* must be the file encoding */
- {
- set_file_encoding(display);
- encoding = display->file_encoding;
- }
-
- switch (encoding)
- {
- case E_FILE:
- value = png_gamma_16bit_correct(value*257, display->gamma_to_linear);
- break;
-
- case E_sRGB:
- value = png_sRGB_table[value];
- break;
-
- case E_LINEAR:
- break;
-
- case E_LINEAR8:
- value *= 257;
- break;
-
- default:
- png_error(display->image->opaque->png_ptr,
- "unexpected encoding (internal error)");
- break;
- }
-
- return value;
-}
-
-static png_uint_32
-png_colormap_compose(png_image_read_control *display,
- png_uint_32 foreground, int foreground_encoding, png_uint_32 alpha,
- png_uint_32 background, int encoding)
-{
- /* The file value is composed on the background, the background has the given
- * encoding and so does the result, the file is encoded with E_FILE and the
- * file and alpha are 8-bit values. The (output) encoding will always be
- * E_LINEAR or E_sRGB.
- */
- png_uint_32 f = decode_gamma(display, foreground, foreground_encoding);
- png_uint_32 b = decode_gamma(display, background, encoding);
-
- /* The alpha is always an 8-bit value (it comes from the palette), the value
- * scaled by 255 is what PNG_sRGB_FROM_LINEAR requires.
- */
- f = f * alpha + b * (255-alpha);
-
- if (encoding == E_LINEAR)
- {
- /* Scale to 65535; divide by 255, approximately (in fact this is extremely
- * accurate, it divides by 255.00000005937181414556, with no overflow.)
- */
- f *= 257; /* Now scaled by 65535 */
- f += f >> 16;
- f = (f+32768) >> 16;
- }
-
- else /* E_sRGB */
- f = PNG_sRGB_FROM_LINEAR(f);
-
- return f;
-}
-
-/* NOTE: E_LINEAR values to this routine must be 16-bit, but E_FILE values must
- * be 8-bit.
- */
-static void
-png_create_colormap_entry(png_image_read_control *display,
- png_uint_32 ip, png_uint_32 red, png_uint_32 green, png_uint_32 blue,
- png_uint_32 alpha, int encoding)
-{
- png_imagep image = display->image;
- const int output_encoding = (image->format & PNG_FORMAT_FLAG_LINEAR) ?
- E_LINEAR : E_sRGB;
- const int convert_to_Y = (image->format & PNG_FORMAT_FLAG_COLOR) == 0 &&
- (red != green || green != blue);
-
- if (ip > 255)
- png_error(image->opaque->png_ptr, "color-map index out of range");
-
- /* Update the cache with whether the file gamma is significantly different
- * from sRGB.
- */
- if (encoding == E_FILE)
- {
- if (display->file_encoding == E_NOTSET)
- set_file_encoding(display);
-
- /* Note that the cached value may be E_FILE too, but if it is then the
- * gamma_to_linear member has been set.
- */
- encoding = display->file_encoding;
- }
-
- if (encoding == E_FILE)
- {
- png_fixed_point g = display->gamma_to_linear;
-
- red = png_gamma_16bit_correct(red*257, g);
- green = png_gamma_16bit_correct(green*257, g);
- blue = png_gamma_16bit_correct(blue*257, g);
-
- if (convert_to_Y || output_encoding == E_LINEAR)
- {
- alpha *= 257;
- encoding = E_LINEAR;
- }
-
- else
- {
- red = PNG_sRGB_FROM_LINEAR(red * 255);
- green = PNG_sRGB_FROM_LINEAR(green * 255);
- blue = PNG_sRGB_FROM_LINEAR(blue * 255);
- encoding = E_sRGB;
- }
- }
-
- else if (encoding == E_LINEAR8)
- {
- /* This encoding occurs quite frequently in test cases because PngSuite
- * includes a gAMA 1.0 chunk with most images.
- */
- red *= 257;
- green *= 257;
- blue *= 257;
- alpha *= 257;
- encoding = E_LINEAR;
- }
-
- else if (encoding == E_sRGB && (convert_to_Y || output_encoding == E_LINEAR))
- {
- /* The values are 8-bit sRGB values, but must be converted to 16-bit
- * linear.
- */
- red = png_sRGB_table[red];
- green = png_sRGB_table[green];
- blue = png_sRGB_table[blue];
- alpha *= 257;
- encoding = E_LINEAR;
- }
-
- /* This is set if the color isn't gray but the output is. */
- if (encoding == E_LINEAR)
- {
- if (convert_to_Y)
- {
- /* NOTE: these values are copied from png_do_rgb_to_gray */
- png_uint_32 y = (png_uint_32)6968 * red + (png_uint_32)23434 * green +
- (png_uint_32)2366 * blue;
-
- if (output_encoding == E_LINEAR)
- y = (y + 16384) >> 15;
-
- else
- {
- /* y is scaled by 32768, we need it scaled by 255: */
- y = (y + 128) >> 8;
- y *= 255;
- y = PNG_sRGB_FROM_LINEAR((y + 64) >> 7);
- encoding = E_sRGB;
- }
-
- blue = red = green = y;
- }
-
- else if (output_encoding == E_sRGB)
- {
- red = PNG_sRGB_FROM_LINEAR(red * 255);
- green = PNG_sRGB_FROM_LINEAR(green * 255);
- blue = PNG_sRGB_FROM_LINEAR(blue * 255);
- alpha = PNG_DIV257(alpha);
- encoding = E_sRGB;
- }
- }
-
- if (encoding != output_encoding)
- png_error(image->opaque->png_ptr, "bad encoding (internal error)");
-
- /* Store the value. */
- {
-# ifdef PNG_FORMAT_BGR_SUPPORTED
- const int afirst = (image->format & PNG_FORMAT_FLAG_AFIRST) != 0 &&
- (image->format & PNG_FORMAT_FLAG_ALPHA) != 0;
-# else
-# define afirst 0
-# endif
-# ifdef PNG_FORMAT_BGR_SUPPORTED
- const int bgr = (image->format & PNG_FORMAT_FLAG_BGR) ? 2 : 0;
-# else
-# define bgr 0
-# endif
-
- if (output_encoding == E_LINEAR)
- {
- png_uint_16p entry = png_voidcast(png_uint_16p, display->colormap);
-
- entry += ip * PNG_IMAGE_SAMPLE_CHANNELS(image->format);
-
- /* The linear 16-bit values must be pre-multiplied by the alpha channel
- * value, if less than 65535 (this is, effectively, composite on black
- * if the alpha channel is removed.)
- */
- switch (PNG_IMAGE_SAMPLE_CHANNELS(image->format))
- {
- case 4:
- entry[afirst ? 0 : 3] = (png_uint_16)alpha;
- /* FALL THROUGH */
-
- case 3:
- if (alpha < 65535)
- {
- if (alpha > 0)
- {
- blue = (blue * alpha + 32767U)/65535U;
- green = (green * alpha + 32767U)/65535U;
- red = (red * alpha + 32767U)/65535U;
- }
-
- else
- red = green = blue = 0;
- }
- entry[afirst + (2 ^ bgr)] = (png_uint_16)blue;
- entry[afirst + 1] = (png_uint_16)green;
- entry[afirst + bgr] = (png_uint_16)red;
- break;
-
- case 2:
- entry[1 ^ afirst] = (png_uint_16)alpha;
- /* FALL THROUGH */
-
- case 1:
- if (alpha < 65535)
- {
- if (alpha > 0)
- green = (green * alpha + 32767U)/65535U;
-
- else
- green = 0;
- }
- entry[afirst] = (png_uint_16)green;
- break;
-
- default:
- break;
- }
- }
-
- else /* output encoding is E_sRGB */
- {
- png_bytep entry = png_voidcast(png_bytep, display->colormap);
-
- entry += ip * PNG_IMAGE_SAMPLE_CHANNELS(image->format);
-
- switch (PNG_IMAGE_SAMPLE_CHANNELS(image->format))
- {
- case 4:
- entry[afirst ? 0 : 3] = (png_byte)alpha;
- case 3:
- entry[afirst + (2 ^ bgr)] = (png_byte)blue;
- entry[afirst + 1] = (png_byte)green;
- entry[afirst + bgr] = (png_byte)red;
- break;
-
- case 2:
- entry[1 ^ afirst] = (png_byte)alpha;
- case 1:
- entry[afirst] = (png_byte)green;
- break;
-
- default:
- break;
- }
- }
-
-# ifdef afirst
-# undef afirst
-# endif
-# ifdef bgr
-# undef bgr
-# endif
- }
-}
-
-static int
-make_gray_file_colormap(png_image_read_control *display)
-{
- unsigned int i;
-
- for (i=0; i<256; ++i)
- png_create_colormap_entry(display, i, i, i, i, 255, E_FILE);
-
- return i;
-}
-
-static int
-make_gray_colormap(png_image_read_control *display)
-{
- unsigned int i;
-
- for (i=0; i<256; ++i)
- png_create_colormap_entry(display, i, i, i, i, 255, E_sRGB);
-
- return i;
-}
-#define PNG_GRAY_COLORMAP_ENTRIES 256
-
-static int
-make_ga_colormap(png_image_read_control *display)
-{
- unsigned int i, a;
-
- /* Alpha is retained, the output will be a color-map with entries
- * selected by six levels of alpha. One transparent entry, 6 gray
- * levels for all the intermediate alpha values, leaving 230 entries
- * for the opaque grays. The color-map entries are the six values
- * [0..5]*51, the GA processing uses PNG_DIV51(value) to find the
- * relevant entry.
- *
- * if (alpha > 229) // opaque
- * {
- * // The 231 entries are selected to make the math below work:
- * base = 0;
- * entry = (231 * gray + 128) >> 8;
- * }
- * else if (alpha < 26) // transparent
- * {
- * base = 231;
- * entry = 0;
- * }
- * else // partially opaque
- * {
- * base = 226 + 6 * PNG_DIV51(alpha);
- * entry = PNG_DIV51(gray);
- * }
- */
- i = 0;
- while (i < 231)
- {
- unsigned int gray = (i * 256 + 115) / 231;
- png_create_colormap_entry(display, i++, gray, gray, gray, 255, E_sRGB);
- }
-
- /* 255 is used here for the component values for consistency with the code
- * that undoes premultiplication in pngwrite.c.
- */
- png_create_colormap_entry(display, i++, 255, 255, 255, 0, E_sRGB);
-
- for (a=1; a<5; ++a)
- {
- unsigned int g;
-
- for (g=0; g<6; ++g)
- png_create_colormap_entry(display, i++, g*51, g*51, g*51, a*51,
- E_sRGB);
- }
-
- return i;
-}
-
-#define PNG_GA_COLORMAP_ENTRIES 256
-
-static int
-make_rgb_colormap(png_image_read_control *display)
-{
- unsigned int i, r;
-
- /* Build a 6x6x6 opaque RGB cube */
- for (i=r=0; r<6; ++r)
- {
- unsigned int g;
-
- for (g=0; g<6; ++g)
- {
- unsigned int b;
-
- for (b=0; b<6; ++b)
- png_create_colormap_entry(display, i++, r*51, g*51, b*51, 255,
- E_sRGB);
- }
- }
-
- return i;
-}
-
-#define PNG_RGB_COLORMAP_ENTRIES 216
-
-/* Return a palette index to the above palette given three 8-bit sRGB values. */
-#define PNG_RGB_INDEX(r,g,b) \
- ((png_byte)(6 * (6 * PNG_DIV51(r) + PNG_DIV51(g)) + PNG_DIV51(b)))
-
-static int
-png_image_read_colormap(png_voidp argument)
-{
- png_image_read_control *display =
- png_voidcast(png_image_read_control*, argument);
- const png_imagep image = display->image;
-
- const png_structrp png_ptr = image->opaque->png_ptr;
- const png_uint_32 output_format = image->format;
- const int output_encoding = (output_format & PNG_FORMAT_FLAG_LINEAR) ?
- E_LINEAR : E_sRGB;
-
- unsigned int cmap_entries;
- unsigned int output_processing; /* Output processing option */
- unsigned int data_encoding = E_NOTSET; /* Encoding libpng must produce */
-
- /* Background information; the background color and the index of this color
- * in the color-map if it exists (else 256).
- */
- unsigned int background_index = 256;
- png_uint_32 back_r, back_g, back_b;
-
- /* Flags to accumulate things that need to be done to the input. */
- int expand_tRNS = 0;
-
- /* Exclude the NYI feature of compositing onto a color-mapped buffer; it is
- * very difficult to do, the results look awful, and it is difficult to see
- * what possible use it is because the application can't control the
- * color-map.
- */
- if (((png_ptr->color_type & PNG_COLOR_MASK_ALPHA) != 0 ||
- png_ptr->num_trans > 0) /* alpha in input */ &&
- ((output_format & PNG_FORMAT_FLAG_ALPHA) == 0) /* no alpha in output */)
- {
- if (output_encoding == E_LINEAR) /* compose on black */
- back_b = back_g = back_r = 0;
-
- else if (display->background == NULL /* no way to remove it */)
- png_error(png_ptr,
- "a background color must be supplied to remove alpha/transparency");
-
- /* Get a copy of the background color (this avoids repeating the checks
- * below.) The encoding is 8-bit sRGB or 16-bit linear, depending on the
- * output format.
- */
- else
- {
- back_g = display->background->green;
- if (output_format & PNG_FORMAT_FLAG_COLOR)
- {
- back_r = display->background->red;
- back_b = display->background->blue;
- }
- else
- back_b = back_r = back_g;
- }
- }
-
- else if (output_encoding == E_LINEAR)
- back_b = back_r = back_g = 65535;
-
- else
- back_b = back_r = back_g = 255;
-
- /* Default the input file gamma if required - this is necessary because
- * libpng assumes that if no gamma information is present the data is in the
- * output format, but the simplified API deduces the gamma from the input
- * format.
- */
- if ((png_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_GAMMA) == 0)
- {
- /* Do this directly, not using the png_colorspace functions, to ensure
- * that it happens even if the colorspace is invalid (though probably if
- * it is the setting will be ignored) Note that the same thing can be
- * achieved at the application interface with png_set_gAMA.
- */
- if (png_ptr->bit_depth == 16 &&
- (image->flags & PNG_IMAGE_FLAG_16BIT_sRGB) == 0)
- png_ptr->colorspace.gamma = PNG_GAMMA_LINEAR;
-
- else
- png_ptr->colorspace.gamma = PNG_GAMMA_sRGB_INVERSE;
-
- png_ptr->colorspace.flags |= PNG_COLORSPACE_HAVE_GAMMA;
- }
-
- /* Decide what to do based on the PNG color type of the input data. The
- * utility function png_create_colormap_entry deals with most aspects of the
- * output transformations; this code works out how to produce bytes of
- * color-map entries from the original format.
- */
- switch (png_ptr->color_type)
- {
- case PNG_COLOR_TYPE_GRAY:
- if (png_ptr->bit_depth <= 8)
- {
- /* There at most 256 colors in the output, regardless of
- * transparency.
- */
- unsigned int step, i, val, trans = 256/*ignore*/, back_alpha = 0;
-
- cmap_entries = 1U << png_ptr->bit_depth;
- if (cmap_entries > image->colormap_entries)
- png_error(png_ptr, "gray[8] color-map: too few entries");
-
- step = 255 / (cmap_entries - 1);
- output_processing = PNG_CMAP_NONE;
-
- /* If there is a tRNS chunk then this either selects a transparent
- * value or, if the output has no alpha, the background color.
- */
- if (png_ptr->num_trans > 0)
- {
- trans = png_ptr->trans_color.gray;
-
- if ((output_format & PNG_FORMAT_FLAG_ALPHA) == 0)
- back_alpha = output_encoding == E_LINEAR ? 65535 : 255;
- }
-
- /* png_create_colormap_entry just takes an RGBA and writes the
- * corresponding color-map entry using the format from 'image',
- * including the required conversion to sRGB or linear as
- * appropriate. The input values are always either sRGB (if the
- * gamma correction flag is 0) or 0..255 scaled file encoded values
- * (if the function must gamma correct them).
- */
- for (i=val=0; i<cmap_entries; ++i, val += step)
- {
- /* 'i' is a file value. While this will result in duplicated
- * entries for 8-bit non-sRGB encoded files it is necessary to
- * have non-gamma corrected values to do tRNS handling.
- */
- if (i != trans)
- png_create_colormap_entry(display, i, val, val, val, 255,
- E_FILE/*8-bit with file gamma*/);
-
- /* Else this entry is transparent. The colors don't matter if
- * there is an alpha channel (back_alpha == 0), but it does no
- * harm to pass them in; the values are not set above so this
- * passes in white.
- *
- * NOTE: this preserves the full precision of the application
- * supplied background color when it is used.
- */
- else
- png_create_colormap_entry(display, i, back_r, back_g, back_b,
- back_alpha, output_encoding);
- }
-
- /* We need libpng to preserve the original encoding. */
- data_encoding = E_FILE;
-
- /* The rows from libpng, while technically gray values, are now also
- * color-map indicies; however, they may need to be expanded to 1
- * byte per pixel. This is what png_set_packing does (i.e., it
- * unpacks the bit values into bytes.)
- */
- if (png_ptr->bit_depth < 8)
- png_set_packing(png_ptr);
- }
-
- else /* bit depth is 16 */
- {
- /* The 16-bit input values can be converted directly to 8-bit gamma
- * encoded values; however, if a tRNS chunk is present 257 color-map
- * entries are required. This means that the extra entry requires
- * special processing; add an alpha channel, sacrifice gray level
- * 254 and convert transparent (alpha==0) entries to that.
- *
- * Use libpng to chop the data to 8 bits. Convert it to sRGB at the
- * same time to minimize quality loss. If a tRNS chunk is present
- * this means libpng must handle it too; otherwise it is impossible
- * to do the exact match on the 16-bit value.
- *
- * If the output has no alpha channel *and* the background color is
- * gray then it is possible to let libpng handle the substitution by
- * ensuring that the corresponding gray level matches the background
- * color exactly.
- */
- data_encoding = E_sRGB;
-
- if (PNG_GRAY_COLORMAP_ENTRIES > image->colormap_entries)
- png_error(png_ptr, "gray[16] color-map: too few entries");
-
- cmap_entries = make_gray_colormap(display);
-
- if (png_ptr->num_trans > 0)
- {
- unsigned int back_alpha;
-
- if (output_format & PNG_FORMAT_FLAG_ALPHA)
- back_alpha = 0;
-
- else
- {
- if (back_r == back_g && back_g == back_b)
- {
- /* Background is gray; no special processing will be
- * required.
- */
- png_color_16 c;
- png_uint_32 gray = back_g;
-
- if (output_encoding == E_LINEAR)
- {
- gray = PNG_sRGB_FROM_LINEAR(gray * 255);
-
- /* And make sure the corresponding palette entry
- * matches.
- */
- png_create_colormap_entry(display, gray, back_g, back_g,
- back_g, 65535, E_LINEAR);
- }
-
- /* The background passed to libpng, however, must be the
- * sRGB value.
- */
- c.index = 0; /*unused*/
- c.gray = c.red = c.green = c.blue = (png_uint_16)gray;
-
- /* NOTE: does this work without expanding tRNS to alpha?
- * It should be the color->gray case below apparently
- * doesn't.
- */
- png_set_background_fixed(png_ptr, &c,
- PNG_BACKGROUND_GAMMA_SCREEN, 0/*need_expand*/,
- 0/*gamma: not used*/);
-
- output_processing = PNG_CMAP_NONE;
- break;
- }
-
- back_alpha = output_encoding == E_LINEAR ? 65535 : 255;
- }
-
- /* output_processing means that the libpng-processed row will be
- * 8-bit GA and it has to be processing to single byte color-map
- * values. Entry 254 is replaced by either a completely
- * transparent entry or by the background color at full
- * precision (and the background color is not a simple gray leve
- * in this case.)
- */
- expand_tRNS = 1;
- output_processing = PNG_CMAP_TRANS;
- background_index = 254;
-
- /* And set (overwrite) color-map entry 254 to the actual
- * background color at full precision.
- */
- png_create_colormap_entry(display, 254, back_r, back_g, back_b,
- back_alpha, output_encoding);
- }
-
- else
- output_processing = PNG_CMAP_NONE;
- }
- break;
-
- case PNG_COLOR_TYPE_GRAY_ALPHA:
- /* 8-bit or 16-bit PNG with two channels - gray and alpha. A minimum
- * of 65536 combinations. If, however, the alpha channel is to be
- * removed there are only 256 possibilities if the background is gray.
- * (Otherwise there is a subset of the 65536 possibilities defined by
- * the triangle between black, white and the background color.)
- *
- * Reduce 16-bit files to 8-bit and sRGB encode the result. No need to
- * worry about tRNS matching - tRNS is ignored if there is an alpha
- * channel.
- */
- data_encoding = E_sRGB;
-
- if (output_format & PNG_FORMAT_FLAG_ALPHA)
- {
- if (PNG_GA_COLORMAP_ENTRIES > image->colormap_entries)
- png_error(png_ptr, "gray+alpha color-map: too few entries");
-
- cmap_entries = make_ga_colormap(display);
-
- background_index = PNG_CMAP_GA_BACKGROUND;
- output_processing = PNG_CMAP_GA;
- }
-
- else /* alpha is removed */
- {
- /* Alpha must be removed as the PNG data is processed when the
- * background is a color because the G and A channels are
- * independent and the vector addition (non-parallel vectors) is a
- * 2-D problem.
- *
- * This can be reduced to the same algorithm as above by making a
- * colormap containing gray levels (for the opaque grays), a
- * background entry (for a transparent pixel) and a set of four six
- * level color values, one set for each intermediate alpha value.
- * See the comments in make_ga_colormap for how this works in the
- * per-pixel processing.
- *
- * If the background is gray, however, we only need a 256 entry gray
- * level color map. It is sufficient to make the entry generated
- * for the background color be exactly the color specified.
- */
- if ((output_format & PNG_FORMAT_FLAG_COLOR) == 0 ||
- (back_r == back_g && back_g == back_b))
- {
- /* Background is gray; no special processing will be required. */
- png_color_16 c;
- png_uint_32 gray = back_g;
-
- if (PNG_GRAY_COLORMAP_ENTRIES > image->colormap_entries)
- png_error(png_ptr, "gray-alpha color-map: too few entries");
-
- cmap_entries = make_gray_colormap(display);
-
- if (output_encoding == E_LINEAR)
- {
- gray = PNG_sRGB_FROM_LINEAR(gray * 255);
-
- /* And make sure the corresponding palette entry matches. */
- png_create_colormap_entry(display, gray, back_g, back_g,
- back_g, 65535, E_LINEAR);
- }
-
- /* The background passed to libpng, however, must be the sRGB
- * value.
- */
- c.index = 0; /*unused*/
- c.gray = c.red = c.green = c.blue = (png_uint_16)gray;
-
- png_set_background_fixed(png_ptr, &c,
- PNG_BACKGROUND_GAMMA_SCREEN, 0/*need_expand*/,
- 0/*gamma: not used*/);
-
- output_processing = PNG_CMAP_NONE;
- }
-
- else
- {
- png_uint_32 i, a;
-
- /* This is the same as png_make_ga_colormap, above, except that
- * the entries are all opaque.
- */
- if (PNG_GA_COLORMAP_ENTRIES > image->colormap_entries)
- png_error(png_ptr, "ga-alpha color-map: too few entries");
-
- i = 0;
- while (i < 231)
- {
- png_uint_32 gray = (i * 256 + 115) / 231;
- png_create_colormap_entry(display, i++, gray, gray, gray,
- 255, E_sRGB);
- }
-
- /* NOTE: this preserves the full precision of the application
- * background color.
- */
- background_index = i;
- png_create_colormap_entry(display, i++, back_r, back_g, back_b,
- output_encoding == E_LINEAR ? 65535U : 255U, output_encoding);
-
- /* For non-opaque input composite on the sRGB background - this
- * requires inverting the encoding for each component. The input
- * is still converted to the sRGB encoding because this is a
- * reasonable approximate to the logarithmic curve of human
- * visual sensitivity, at least over the narrow range which PNG
- * represents. Consequently 'G' is always sRGB encoded, while
- * 'A' is linear. We need the linear background colors.
- */
- if (output_encoding == E_sRGB) /* else already linear */
- {
- /* This may produce a value not exactly matching the
- * background, but that's ok because these numbers are only
- * used when alpha != 0
- */
- back_r = png_sRGB_table[back_r];
- back_g = png_sRGB_table[back_g];
- back_b = png_sRGB_table[back_b];
- }
-
- for (a=1; a<5; ++a)
- {
- unsigned int g;
-
- /* PNG_sRGB_FROM_LINEAR expects a 16-bit linear value scaled
- * by an 8-bit alpha value (0..255).
- */
- png_uint_32 alpha = 51 * a;
- png_uint_32 back_rx = (255-alpha) * back_r;
- png_uint_32 back_gx = (255-alpha) * back_g;
- png_uint_32 back_bx = (255-alpha) * back_b;
-
- for (g=0; g<6; ++g)
- {
- png_uint_32 gray = png_sRGB_table[g*51] * alpha;
-
- png_create_colormap_entry(display, i++,
- PNG_sRGB_FROM_LINEAR(gray + back_rx),
- PNG_sRGB_FROM_LINEAR(gray + back_gx),
- PNG_sRGB_FROM_LINEAR(gray + back_bx), 255, E_sRGB);
- }
- }
-
- cmap_entries = i;
- output_processing = PNG_CMAP_GA;
- }
- }
- break;
-
- case PNG_COLOR_TYPE_RGB:
- case PNG_COLOR_TYPE_RGB_ALPHA:
- /* Exclude the case where the output is gray; we can always handle this
- * with the cases above.
- */
- if ((output_format & PNG_FORMAT_FLAG_COLOR) == 0)
- {
- /* The color-map will be grayscale, so we may as well convert the
- * input RGB values to a simple grayscale and use the grayscale
- * code above.
- *
- * NOTE: calling this apparently damages the recognition of the
- * transparent color in background color handling; call
- * png_set_tRNS_to_alpha before png_set_background_fixed.
- */
- png_set_rgb_to_gray_fixed(png_ptr, PNG_ERROR_ACTION_NONE, -1,
- -1);
- data_encoding = E_sRGB;
-
- /* The output will now be one or two 8-bit gray or gray+alpha
- * channels. The more complex case arises when the input has alpha.
- */
- if ((png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA ||
- png_ptr->num_trans > 0) &&
- (output_format & PNG_FORMAT_FLAG_ALPHA) != 0)
- {
- /* Both input and output have an alpha channel, so no background
- * processing is required; just map the GA bytes to the right
- * color-map entry.
- */
- expand_tRNS = 1;
-
- if (PNG_GA_COLORMAP_ENTRIES > image->colormap_entries)
- png_error(png_ptr, "rgb[ga] color-map: too few entries");
-
- cmap_entries = make_ga_colormap(display);
- background_index = PNG_CMAP_GA_BACKGROUND;
- output_processing = PNG_CMAP_GA;
- }
-
- else
- {
- /* Either the input or the output has no alpha channel, so there
- * will be no non-opaque pixels in the color-map; it will just be
- * grayscale.
- */
- if (PNG_GRAY_COLORMAP_ENTRIES > image->colormap_entries)
- png_error(png_ptr, "rgb[gray] color-map: too few entries");
-
- /* Ideally this code would use libpng to do the gamma correction,
- * but if an input alpha channel is to be removed we will hit the
- * libpng bug in gamma+compose+rgb-to-gray (the double gamma
- * correction bug). Fix this by dropping the gamma correction in
- * this case and doing it in the palette; this will result in
- * duplicate palette entries, but that's better than the
- * alternative of double gamma correction.
- */
- if ((png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA ||
- png_ptr->num_trans > 0) &&
- png_gamma_not_sRGB(png_ptr->colorspace.gamma))
- {
- cmap_entries = make_gray_file_colormap(display);
- data_encoding = E_FILE;
- }
-
- else
- cmap_entries = make_gray_colormap(display);
-
- /* But if the input has alpha or transparency it must be removed
- */
- if (png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA ||
- png_ptr->num_trans > 0)
- {
- png_color_16 c;
- png_uint_32 gray = back_g;
-
- /* We need to ensure that the application background exists in
- * the colormap and that completely transparent pixels map to
- * it. Achieve this simply by ensuring that the entry
- * selected for the background really is the background color.
- */
- if (data_encoding == E_FILE) /* from the fixup above */
- {
- /* The app supplied a gray which is in output_encoding, we
- * need to convert it to a value of the input (E_FILE)
- * encoding then set this palette entry to the required
- * output encoding.
- */
- if (output_encoding == E_sRGB)
- gray = png_sRGB_table[gray]; /* now E_LINEAR */
-
- gray = PNG_DIV257(png_gamma_16bit_correct(gray,
- png_ptr->colorspace.gamma)); /* now E_FILE */
-
- /* And make sure the corresponding palette entry contains
- * exactly the required sRGB value.
- */
- png_create_colormap_entry(display, gray, back_g, back_g,
- back_g, 0/*unused*/, output_encoding);
- }
-
- else if (output_encoding == E_LINEAR)
- {
- gray = PNG_sRGB_FROM_LINEAR(gray * 255);
-
- /* And make sure the corresponding palette entry matches.
- */
- png_create_colormap_entry(display, gray, back_g, back_g,
- back_g, 0/*unused*/, E_LINEAR);
- }
-
- /* The background passed to libpng, however, must be the
- * output (normally sRGB) value.
- */
- c.index = 0; /*unused*/
- c.gray = c.red = c.green = c.blue = (png_uint_16)gray;
-
- /* NOTE: the following is apparently a bug in libpng. Without
- * it the transparent color recognition in
- * png_set_background_fixed seems to go wrong.
- */
- expand_tRNS = 1;
- png_set_background_fixed(png_ptr, &c,
- PNG_BACKGROUND_GAMMA_SCREEN, 0/*need_expand*/,
- 0/*gamma: not used*/);
- }
-
- output_processing = PNG_CMAP_NONE;
- }
- }
-
- else /* output is color */
- {
- /* We could use png_quantize here so long as there is no transparent
- * color or alpha; png_quantize ignores alpha. Easier overall just
- * to do it once and using PNG_DIV51 on the 6x6x6 reduced RGB cube.
- * Consequently we always want libpng to produce sRGB data.
- */
- data_encoding = E_sRGB;
-
- /* Is there any transparency or alpha? */
- if (png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA ||
- png_ptr->num_trans > 0)
- {
- /* Is there alpha in the output too? If so all four channels are
- * processed into a special RGB cube with alpha support.
- */
- if (output_format & PNG_FORMAT_FLAG_ALPHA)
- {
- png_uint_32 r;
-
- if (PNG_RGB_COLORMAP_ENTRIES+1+27 > image->colormap_entries)
- png_error(png_ptr, "rgb+alpha color-map: too few entries");
-
- cmap_entries = make_rgb_colormap(display);
-
- /* Add a transparent entry. */
- png_create_colormap_entry(display, cmap_entries, 255, 255,
- 255, 0, E_sRGB);
-
- /* This is stored as the background index for the processing
- * algorithm.
- */
- background_index = cmap_entries++;
-
- /* Add 27 r,g,b entries each with alpha 0.5. */
- for (r=0; r<256; r = (r << 1) | 0x7f)
- {
- png_uint_32 g;
-
- for (g=0; g<256; g = (g << 1) | 0x7f)
- {
- png_uint_32 b;
-
- /* This generates components with the values 0, 127 and
- * 255
- */
- for (b=0; b<256; b = (b << 1) | 0x7f)
- png_create_colormap_entry(display, cmap_entries++,
- r, g, b, 128, E_sRGB);
- }
- }
-
- expand_tRNS = 1;
- output_processing = PNG_CMAP_RGB_ALPHA;
- }
-
- else
- {
- /* Alpha/transparency must be removed. The background must
- * exist in the color map (achieved by setting adding it after
- * the 666 color-map). If the standard processing code will
- * pick up this entry automatically that's all that is
- * required; libpng can be called to do the background
- * processing.
- */
- unsigned int sample_size =
- PNG_IMAGE_SAMPLE_SIZE(output_format);
- png_uint_32 r, g, b; /* sRGB background */
-
- if (PNG_RGB_COLORMAP_ENTRIES+1+27 > image->colormap_entries)
- png_error(png_ptr, "rgb-alpha color-map: too few entries");
-
- cmap_entries = make_rgb_colormap(display);
-
- png_create_colormap_entry(display, cmap_entries, back_r,
- back_g, back_b, 0/*unused*/, output_encoding);
-
- if (output_encoding == E_LINEAR)
- {
- r = PNG_sRGB_FROM_LINEAR(back_r * 255);
- g = PNG_sRGB_FROM_LINEAR(back_g * 255);
- b = PNG_sRGB_FROM_LINEAR(back_b * 255);
- }
-
- else
- {
- r = back_r;
- g = back_g;
- b = back_g;
- }
-
- /* Compare the newly-created color-map entry with the one the
- * PNG_CMAP_RGB algorithm will use. If the two entries don't
- * match, add the new one and set this as the background
- * index.
- */
- if (memcmp((png_const_bytep)display->colormap +
- sample_size * cmap_entries,
- (png_const_bytep)display->colormap +
- sample_size * PNG_RGB_INDEX(r,g,b),
- sample_size) != 0)
- {
- /* The background color must be added. */
- background_index = cmap_entries++;
-
- /* Add 27 r,g,b entries each with created by composing with
- * the background at alpha 0.5.
- */
- for (r=0; r<256; r = (r << 1) | 0x7f)
- {
- for (g=0; g<256; g = (g << 1) | 0x7f)
- {
- /* This generates components with the values 0, 127
- * and 255
- */
- for (b=0; b<256; b = (b << 1) | 0x7f)
- png_create_colormap_entry(display, cmap_entries++,
- png_colormap_compose(display, r, E_sRGB, 128,
- back_r, output_encoding),
- png_colormap_compose(display, g, E_sRGB, 128,
- back_g, output_encoding),
- png_colormap_compose(display, b, E_sRGB, 128,
- back_b, output_encoding),
- 0/*unused*/, output_encoding);
- }
- }
-
- expand_tRNS = 1;
- output_processing = PNG_CMAP_RGB_ALPHA;
- }
-
- else /* background color is in the standard color-map */
- {
- png_color_16 c;
-
- c.index = 0; /*unused*/
- c.red = (png_uint_16)back_r;
- c.gray = c.green = (png_uint_16)back_g;
- c.blue = (png_uint_16)back_b;
-
- png_set_background_fixed(png_ptr, &c,
- PNG_BACKGROUND_GAMMA_SCREEN, 0/*need_expand*/,
- 0/*gamma: not used*/);
-
- output_processing = PNG_CMAP_RGB;
- }
- }
- }
-
- else /* no alpha or transparency in the input */
- {
- /* Alpha in the output is irrelevant, simply map the opaque input
- * pixels to the 6x6x6 color-map.
- */
- if (PNG_RGB_COLORMAP_ENTRIES > image->colormap_entries)
- png_error(png_ptr, "rgb color-map: too few entries");
-
- cmap_entries = make_rgb_colormap(display);
- output_processing = PNG_CMAP_RGB;
- }
- }
- break;
-
- case PNG_COLOR_TYPE_PALETTE:
- /* It's already got a color-map. It may be necessary to eliminate the
- * tRNS entries though.
- */
- {
- unsigned int num_trans = png_ptr->num_trans;
- png_const_bytep trans = num_trans > 0 ? png_ptr->trans_alpha : NULL;
- png_const_colorp colormap = png_ptr->palette;
- const int do_background = trans != NULL &&
- (output_format & PNG_FORMAT_FLAG_ALPHA) == 0;
- unsigned int i;
-
- /* Just in case: */
- if (trans == NULL)
- num_trans = 0;
-
- output_processing = PNG_CMAP_NONE;
- data_encoding = E_FILE; /* Don't change from color-map indicies */
- cmap_entries = png_ptr->num_palette;
- if (cmap_entries > 256)
- cmap_entries = 256;
-
- if (cmap_entries > image->colormap_entries)
- png_error(png_ptr, "palette color-map: too few entries");
-
- for (i=0; i < cmap_entries; ++i)
- {
- if (do_background && i < num_trans && trans[i] < 255)
- {
- if (trans[i] == 0)
- png_create_colormap_entry(display, i, back_r, back_g,
- back_b, 0, output_encoding);
-
- else
- {
- /* Must compose the PNG file color in the color-map entry
- * on the sRGB color in 'back'.
- */
- png_create_colormap_entry(display, i,
- png_colormap_compose(display, colormap[i].red, E_FILE,
- trans[i], back_r, output_encoding),
- png_colormap_compose(display, colormap[i].green, E_FILE,
- trans[i], back_g, output_encoding),
- png_colormap_compose(display, colormap[i].blue, E_FILE,
- trans[i], back_b, output_encoding),
- output_encoding == E_LINEAR ? trans[i] * 257U :
- trans[i],
- output_encoding);
- }
- }
-
- else
- png_create_colormap_entry(display, i, colormap[i].red,
- colormap[i].green, colormap[i].blue,
- i < num_trans ? trans[i] : 255U, E_FILE/*8-bit*/);
- }
-
- /* The PNG data may have indicies packed in fewer than 8 bits, it
- * must be expanded if so.
- */
- if (png_ptr->bit_depth < 8)
- png_set_packing(png_ptr);
- }
- break;
-
- default:
- png_error(png_ptr, "invalid PNG color type");
- /*NOT REACHED*/
- break;
- }
-
- /* Now deal with the output processing */
- if (expand_tRNS && png_ptr->num_trans > 0 &&
- (png_ptr->color_type & PNG_COLOR_MASK_ALPHA) == 0)
- png_set_tRNS_to_alpha(png_ptr);
-
- switch (data_encoding)
- {
- default:
- png_error(png_ptr, "bad data option (internal error)");
- break;
-
- case E_sRGB:
- /* Change to 8-bit sRGB */
- png_set_alpha_mode_fixed(png_ptr, PNG_ALPHA_PNG, PNG_GAMMA_sRGB);
- /* FALL THROUGH */
-
- case E_FILE:
- if (png_ptr->bit_depth > 8)
- png_set_scale_16(png_ptr);
- break;
- }
-
- if (cmap_entries > 256 || cmap_entries > image->colormap_entries)
- png_error(png_ptr, "color map overflow (BAD internal error)");
-
- image->colormap_entries = cmap_entries;
-
- /* Double check using the recorded background index */
- switch (output_processing)
- {
- case PNG_CMAP_NONE:
- if (background_index != PNG_CMAP_NONE_BACKGROUND)
- goto bad_background;
- break;
-
- case PNG_CMAP_GA:
- if (background_index != PNG_CMAP_GA_BACKGROUND)
- goto bad_background;
- break;
-
- case PNG_CMAP_TRANS:
- if (background_index >= cmap_entries ||
- background_index != PNG_CMAP_TRANS_BACKGROUND)
- goto bad_background;
- break;
-
- case PNG_CMAP_RGB:
- if (background_index != PNG_CMAP_RGB_BACKGROUND)
- goto bad_background;
- break;
-
- case PNG_CMAP_RGB_ALPHA:
- if (background_index != PNG_CMAP_RGB_ALPHA_BACKGROUND)
- goto bad_background;
- break;
-
- default:
- png_error(png_ptr, "bad processing option (internal error)");
-
- bad_background:
- png_error(png_ptr, "bad background index (internal error)");
- }
-
- display->colormap_processing = output_processing;
-
- return 1/*ok*/;
-}
-
-/* The final part of the color-map read called from png_image_finish_read. */
-static int
-png_image_read_and_map(png_voidp argument)
-{
- png_image_read_control *display = png_voidcast(png_image_read_control*,
- argument);
- png_imagep image = display->image;
- png_structrp png_ptr = image->opaque->png_ptr;
- int passes;
-
- /* Called when the libpng data must be transformed into the color-mapped
- * form. There is a local row buffer in display->local and this routine must
- * do the interlace handling.
- */
- switch (png_ptr->interlaced)
- {
- case PNG_INTERLACE_NONE:
- passes = 1;
- break;
-
- case PNG_INTERLACE_ADAM7:
- passes = PNG_INTERLACE_ADAM7_PASSES;
- break;
-
- default:
- passes = 0;
- png_error(png_ptr, "unknown interlace type");
- }
-
- {
- png_uint_32 height = image->height;
- png_uint_32 width = image->width;
- int proc = display->colormap_processing;
- png_bytep first_row = png_voidcast(png_bytep, display->first_row);
- ptrdiff_t step_row = display->row_bytes;
- int pass;
-
- for (pass = 0; pass < passes; ++pass)
- {
- unsigned int startx, stepx, stepy;
- png_uint_32 y;
-
- if (png_ptr->interlaced == PNG_INTERLACE_ADAM7)
- {
- /* The row may be empty for a short image: */
- if (PNG_PASS_COLS(width, pass) == 0)
- continue;
-
- startx = PNG_PASS_START_COL(pass);
- stepx = PNG_PASS_COL_OFFSET(pass);
- y = PNG_PASS_START_ROW(pass);
- stepy = PNG_PASS_ROW_OFFSET(pass);
- }
-
- else
- {
- y = 0;
- startx = 0;
- stepx = stepy = 1;
- }
-
- for (; y<height; y += stepy)
- {
- png_bytep inrow = png_voidcast(png_bytep, display->local_row);
- png_bytep outrow = first_row + y * step_row;
- png_const_bytep end_row = outrow + width;
-
- /* Read read the libpng data into the temporary buffer. */
- png_read_row(png_ptr, inrow, NULL);
-
- /* Now process the row according to the processing option, note
- * that the caller verifies that the format of the libpng output
- * data is as required.
- */
- outrow += startx;
- switch (proc)
- {
- case PNG_CMAP_GA:
- for (; outrow < end_row; outrow += stepx)
- {
- /* The data is always in the PNG order */
- unsigned int gray = *inrow++;
- unsigned int alpha = *inrow++;
- unsigned int entry;
-
- /* NOTE: this code is copied as a comment in
- * make_ga_colormap above. Please update the
- * comment if you change this code!
- */
- if (alpha > 229) /* opaque */
- {
- entry = (231 * gray + 128) >> 8;
- }
- else if (alpha < 26) /* transparent */
- {
- entry = 231;
- }
- else /* partially opaque */
- {
- entry = 226 + 6 * PNG_DIV51(alpha) + PNG_DIV51(gray);
- }
-
- *outrow = (png_byte)entry;
- }
- break;
-
- case PNG_CMAP_TRANS:
- for (; outrow < end_row; outrow += stepx)
- {
- png_byte gray = *inrow++;
- png_byte alpha = *inrow++;
-
- if (alpha == 0)
- *outrow = PNG_CMAP_TRANS_BACKGROUND;
-
- else if (gray != PNG_CMAP_TRANS_BACKGROUND)
- *outrow = gray;
-
- else
- *outrow = (png_byte)(PNG_CMAP_TRANS_BACKGROUND+1);
- }
- break;
-
- case PNG_CMAP_RGB:
- for (; outrow < end_row; outrow += stepx)
- {
- *outrow = PNG_RGB_INDEX(inrow[0], inrow[1], inrow[2]);
- inrow += 3;
- }
- break;
-
- case PNG_CMAP_RGB_ALPHA:
- for (; outrow < end_row; outrow += stepx)
- {
- unsigned int alpha = inrow[3];
-
- /* Because the alpha entries only hold alpha==0.5 values
- * split the processing at alpha==0.25 (64) and 0.75
- * (196).
- */
-
- if (alpha >= 196)
- *outrow = PNG_RGB_INDEX(inrow[0], inrow[1],
- inrow[2]);
-
- else if (alpha < 64)
- *outrow = PNG_CMAP_RGB_ALPHA_BACKGROUND;
-
- else
- {
- /* Likewise there are three entries for each of r, g
- * and b. We could select the entry by popcount on
- * the top two bits on those architectures that
- * support it, this is what the code below does,
- * crudely.
- */
- unsigned int back_i = PNG_CMAP_RGB_ALPHA_BACKGROUND+1;
-
- /* Here are how the values map:
- *
- * 0x00 .. 0x3f -> 0
- * 0x40 .. 0xbf -> 1
- * 0xc0 .. 0xff -> 2
- *
- * So, as above with the explicit alpha checks, the
- * breakpoints are at 64 and 196.
- */
- if (inrow[0] & 0x80) back_i += 9; /* red */
- if (inrow[0] & 0x40) back_i += 9;
- if (inrow[0] & 0x80) back_i += 3; /* green */
- if (inrow[0] & 0x40) back_i += 3;
- if (inrow[0] & 0x80) back_i += 1; /* blue */
- if (inrow[0] & 0x40) back_i += 1;
-
- *outrow = (png_byte)back_i;
- }
-
- inrow += 4;
- }
- break;
-
- default:
- break;
- }
- }
- }
- }
-
- return 1;
-}
-
-static int
-png_image_read_colormapped(png_voidp argument)
-{
- png_image_read_control *display = png_voidcast(png_image_read_control*,
- argument);
- png_imagep image = display->image;
- png_controlp control = image->opaque;
- png_structrp png_ptr = control->png_ptr;
- png_inforp info_ptr = control->info_ptr;
-
- int passes = 0; /* As a flag */
-
- PNG_SKIP_CHUNKS(png_ptr);
-
- /* Update the 'info' structure and make sure the result is as required; first
- * make sure to turn on the interlace handling if it will be required
- * (because it can't be turned on *after* the call to png_read_update_info!)
- */
- if (display->colormap_processing == PNG_CMAP_NONE)
- passes = png_set_interlace_handling(png_ptr);
-
- png_read_update_info(png_ptr, info_ptr);
-
- /* The expected output can be deduced from the colormap_processing option. */
- switch (display->colormap_processing)
- {
- case PNG_CMAP_NONE:
- /* Output must be one channel and one byte per pixel, the output
- * encoding can be anything.
- */
- if ((info_ptr->color_type == PNG_COLOR_TYPE_PALETTE ||
- info_ptr->color_type == PNG_COLOR_TYPE_GRAY) &&
- info_ptr->bit_depth == 8)
- break;
-
- goto bad_output;
-
- case PNG_CMAP_TRANS:
- case PNG_CMAP_GA:
- /* Output must be two channels and the 'G' one must be sRGB, the latter
- * can be checked with an exact number because it should have been set
- * to this number above!
- */
- if (info_ptr->color_type == PNG_COLOR_TYPE_GRAY_ALPHA &&
- info_ptr->bit_depth == 8 &&
- png_ptr->screen_gamma == PNG_GAMMA_sRGB &&
- image->colormap_entries == 256)
- break;
-
- goto bad_output;
-
- case PNG_CMAP_RGB:
- /* Output must be 8-bit sRGB encoded RGB */
- if (info_ptr->color_type == PNG_COLOR_TYPE_RGB &&
- info_ptr->bit_depth == 8 &&
- png_ptr->screen_gamma == PNG_GAMMA_sRGB &&
- image->colormap_entries == 216)
- break;
-
- goto bad_output;
-
- case PNG_CMAP_RGB_ALPHA:
- /* Output must be 8-bit sRGB encoded RGBA */
- if (info_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA &&
- info_ptr->bit_depth == 8 &&
- png_ptr->screen_gamma == PNG_GAMMA_sRGB &&
- image->colormap_entries == 244 /* 216 + 1 + 27 */)
- break;
-
- /* goto bad_output; */
- /* FALL THROUGH */
-
- default:
- bad_output:
- png_error(png_ptr, "bad color-map processing (internal error)");
- }
-
- /* Now read the rows. Do this here if it is possible to read directly into
- * the output buffer, otherwise allocate a local row buffer of the maximum
- * size libpng requires and call the relevant processing routine safely.
- */
- {
- png_voidp first_row = display->buffer;
- ptrdiff_t row_bytes = display->row_stride;
-
- /* The following expression is designed to work correctly whether it gives
- * a signed or an unsigned result.
- */
- if (row_bytes < 0)
- {
- char *ptr = png_voidcast(char*, first_row);
- ptr += (image->height-1) * (-row_bytes);
- first_row = png_voidcast(png_voidp, ptr);
- }
-
- display->first_row = first_row;
- display->row_bytes = row_bytes;
- }
-
- if (passes == 0)
- {
- int result;
- png_voidp row = png_malloc(png_ptr, png_get_rowbytes(png_ptr, info_ptr));
-
- display->local_row = row;
- result = png_safe_execute(image, png_image_read_and_map, display);
- display->local_row = NULL;
- png_free(png_ptr, row);
-
- return result;
- }
-
- else
- {
- png_alloc_size_t row_bytes = display->row_bytes;
-
- while (--passes >= 0)
- {
- png_uint_32 y = image->height;
- png_bytep row = png_voidcast(png_bytep, display->first_row);
-
- while (y-- > 0)
- {
- png_read_row(png_ptr, row, NULL);
- row += row_bytes;
- }
- }
-
- return 1;
- }
-}
-
-/* Just the row reading part of png_image_read. */
-static int
-png_image_read_composite(png_voidp argument)
-{
- png_image_read_control *display = png_voidcast(png_image_read_control*,
- argument);
- png_imagep image = display->image;
- png_structrp png_ptr = image->opaque->png_ptr;
- int passes;
-
- switch (png_ptr->interlaced)
- {
- case PNG_INTERLACE_NONE:
- passes = 1;
- break;
-
- case PNG_INTERLACE_ADAM7:
- passes = PNG_INTERLACE_ADAM7_PASSES;
- break;
-
- default:
- passes = 0;
- png_error(png_ptr, "unknown interlace type");
- }
-
- {
- png_uint_32 height = image->height;
- png_uint_32 width = image->width;
- ptrdiff_t step_row = display->row_bytes;
- unsigned int channels = (image->format & PNG_FORMAT_FLAG_COLOR) ? 3 : 1;
- int pass;
-
- for (pass = 0; pass < passes; ++pass)
- {
- unsigned int startx, stepx, stepy;
- png_uint_32 y;
-
- if (png_ptr->interlaced == PNG_INTERLACE_ADAM7)
- {
- /* The row may be empty for a short image: */
- if (PNG_PASS_COLS(width, pass) == 0)
- continue;
-
- startx = PNG_PASS_START_COL(pass) * channels;
- stepx = PNG_PASS_COL_OFFSET(pass) * channels;
- y = PNG_PASS_START_ROW(pass);
- stepy = PNG_PASS_ROW_OFFSET(pass);
- }
-
- else
- {
- y = 0;
- startx = 0;
- stepx = channels;
- stepy = 1;
- }
-
- for (; y<height; y += stepy)
- {
- png_bytep inrow = png_voidcast(png_bytep, display->local_row);
- png_bytep outrow;
- png_const_bytep end_row;
-
- /* Read the row, which is packed: */
- png_read_row(png_ptr, inrow, NULL);
-
- outrow = png_voidcast(png_bytep, display->first_row);
- outrow += y * step_row;
- end_row = outrow + width * channels;
-
- /* Now do the composition on each pixel in this row. */
- outrow += startx;
- for (; outrow < end_row; outrow += stepx)
- {
- png_byte alpha = inrow[channels];
-
- if (alpha > 0) /* else no change to the output */
- {
- unsigned int c;
-
- for (c=0; c<channels; ++c)
- {
- png_uint_32 component = inrow[c];
-
- if (alpha < 255) /* else just use component */
- {
- /* This is PNG_OPTIMIZED_ALPHA, the component value
- * is a linear 8-bit value. Combine this with the
- * current outrow[c] value which is sRGB encoded.
- * Arithmetic here is 16-bits to preserve the output
- * values correctly.
- */
- component *= 257*255; /* =65535 */
- component += (255-alpha)*png_sRGB_table[outrow[c]];
-
- /* So 'component' is scaled by 255*65535 and is
- * therefore appropriate for the sRGB to linear
- * conversion table.
- */
- component = PNG_sRGB_FROM_LINEAR(component);
- }
-
- outrow[c] = (png_byte)component;
- }
- }
-
- inrow += channels+1; /* components and alpha channel */
- }
- }
- }
- }
-
- return 1;
-}
-
-/* The do_local_background case; called when all the following transforms are to
- * be done:
- *
- * PNG_RGB_TO_GRAY
- * PNG_COMPOSITE
- * PNG_GAMMA
- *
- * This is a work-round for the fact that both the PNG_RGB_TO_GRAY and
- * PNG_COMPOSITE code performs gamma correction, so we get double gamma
- * correction. The fix-up is to prevent the PNG_COMPOSITE operation happening
- * inside libpng, so this routine sees an 8 or 16-bit gray+alpha row and handles
- * the removal or pre-multiplication of the alpha channel.
- */
-static int
-png_image_read_background(png_voidp argument)
-{
- png_image_read_control *display = png_voidcast(png_image_read_control*,
- argument);
- png_imagep image = display->image;
- png_structrp png_ptr = image->opaque->png_ptr;
- png_inforp info_ptr = image->opaque->info_ptr;
- png_uint_32 height = image->height;
- png_uint_32 width = image->width;
- int pass, passes;
-
- /* Double check the convoluted logic below. We expect to get here with
- * libpng doing rgb to gray and gamma correction but background processing
- * left to the png_image_read_background function. The rows libpng produce
- * might be 8 or 16-bit but should always have two channels; gray plus alpha.
- */
- if ((png_ptr->transformations & PNG_RGB_TO_GRAY) == 0)
- png_error(png_ptr, "lost rgb to gray");
-
- if ((png_ptr->transformations & PNG_COMPOSE) != 0)
- png_error(png_ptr, "unexpected compose");
-
- if (png_get_channels(png_ptr, info_ptr) != 2)
- png_error(png_ptr, "lost/gained channels");
-
- /* Expect the 8-bit case to always remove the alpha channel */
- if ((image->format & PNG_FORMAT_FLAG_LINEAR) == 0 &&
- (image->format & PNG_FORMAT_FLAG_ALPHA) != 0)
- png_error(png_ptr, "unexpected 8-bit transformation");
-
- switch (png_ptr->interlaced)
- {
- case PNG_INTERLACE_NONE:
- passes = 1;
- break;
-
- case PNG_INTERLACE_ADAM7:
- passes = PNG_INTERLACE_ADAM7_PASSES;
- break;
-
- default:
- passes = 0;
- png_error(png_ptr, "unknown interlace type");
- }
-
- switch (png_get_bit_depth(png_ptr, info_ptr))
- {
- default:
- png_error(png_ptr, "unexpected bit depth");
- break;
-
- case 8:
- /* 8-bit sRGB gray values with an alpha channel; the alpha channel is
- * to be removed by composing on a backgroundi: either the row if
- * display->background is NULL or display->background->green if not.
- * Unlike the code above ALPHA_OPTIMIZED has *not* been done.
- */
- {
- png_bytep first_row = png_voidcast(png_bytep, display->first_row);
- ptrdiff_t step_row = display->row_bytes;
-
- for (pass = 0; pass < passes; ++pass)
- {
- png_bytep row = png_voidcast(png_bytep,
- display->first_row);
- unsigned int startx, stepx, stepy;
- png_uint_32 y;
-
- if (png_ptr->interlaced == PNG_INTERLACE_ADAM7)
- {
- /* The row may be empty for a short image: */
- if (PNG_PASS_COLS(width, pass) == 0)
- continue;
-
- startx = PNG_PASS_START_COL(pass);
- stepx = PNG_PASS_COL_OFFSET(pass);
- y = PNG_PASS_START_ROW(pass);
- stepy = PNG_PASS_ROW_OFFSET(pass);
- }
-
- else
- {
- y = 0;
- startx = 0;
- stepx = stepy = 1;
- }
-
- if (display->background == NULL)
- {
- for (; y<height; y += stepy)
- {
- png_bytep inrow = png_voidcast(png_bytep,
- display->local_row);
- png_bytep outrow = first_row + y * step_row;
- png_const_bytep end_row = outrow + width;
-
- /* Read the row, which is packed: */
- png_read_row(png_ptr, inrow, NULL);
-
- /* Now do the composition on each pixel in this row. */
- outrow += startx;
- for (; outrow < end_row; outrow += stepx)
- {
- png_byte alpha = inrow[1];
-
- if (alpha > 0) /* else no change to the output */
- {
- png_uint_32 component = inrow[0];
-
- if (alpha < 255) /* else just use component */
- {
- /* Since PNG_OPTIMIZED_ALPHA was not set it is
- * necessary to invert the sRGB transfer
- * function and multiply the alpha out.
- */
- component = png_sRGB_table[component] * alpha;
- component += png_sRGB_table[outrow[0]] *
- (255-alpha);
- component = PNG_sRGB_FROM_LINEAR(component);
- }
-
- outrow[0] = (png_byte)component;
- }
-
- inrow += 2; /* gray and alpha channel */
- }
- }
- }
-
- else /* constant background value */
- {
- png_byte background8 = display->background->green;
- png_uint_16 background = png_sRGB_table[background8];
-
- for (; y<height; y += stepy)
- {
- png_bytep inrow = png_voidcast(png_bytep,
- display->local_row);
- png_bytep outrow = first_row + y * step_row;
- png_const_bytep end_row = outrow + width;
-
- /* Read the row, which is packed: */
- png_read_row(png_ptr, inrow, NULL);
-
- /* Now do the composition on each pixel in this row. */
- outrow += startx;
- for (; outrow < end_row; outrow += stepx)
- {
- png_byte alpha = inrow[1];
-
- if (alpha > 0) /* else use background */
- {
- png_uint_32 component = inrow[0];
-
- if (alpha < 255) /* else just use component */
- {
- component = png_sRGB_table[component] * alpha;
- component += background * (255-alpha);
- component = PNG_sRGB_FROM_LINEAR(component);
- }
-
- outrow[0] = (png_byte)component;
- }
-
- else
- outrow[0] = background8;
-
- inrow += 2; /* gray and alpha channel */
- }
-
- row += display->row_bytes;
- }
- }
- }
- }
- break;
-
- case 16:
- /* 16-bit linear with pre-multiplied alpha; the pre-multiplication must
- * still be done and, maybe, the alpha channel removed. This code also
- * handles the alpha-first option.
- */
- {
- png_uint_16p first_row = png_voidcast(png_uint_16p,
- display->first_row);
- /* The division by two is safe because the caller passed in a
- * stride which was multiplied by 2 (below) to get row_bytes.
- */
- ptrdiff_t step_row = display->row_bytes / 2;
- int preserve_alpha = (image->format & PNG_FORMAT_FLAG_ALPHA) != 0;
- unsigned int outchannels = 1+preserve_alpha;
- int swap_alpha = 0;
-
- if (preserve_alpha && (image->format & PNG_FORMAT_FLAG_AFIRST))
- swap_alpha = 1;
-
- for (pass = 0; pass < passes; ++pass)
- {
- unsigned int startx, stepx, stepy;
- png_uint_32 y;
-
- /* The 'x' start and step are adjusted to output components here.
- */
- if (png_ptr->interlaced == PNG_INTERLACE_ADAM7)
- {
- /* The row may be empty for a short image: */
- if (PNG_PASS_COLS(width, pass) == 0)
- continue;
-
- startx = PNG_PASS_START_COL(pass) * outchannels;
- stepx = PNG_PASS_COL_OFFSET(pass) * outchannels;
- y = PNG_PASS_START_ROW(pass);
- stepy = PNG_PASS_ROW_OFFSET(pass);
- }
-
- else
- {
- y = 0;
- startx = 0;
- stepx = outchannels;
- stepy = 1;
- }
-
- for (; y<height; y += stepy)
- {
- png_const_uint_16p inrow;
- png_uint_16p outrow = first_row + y*step_row;
- png_uint_16p end_row = outrow + width * outchannels;
-
- /* Read the row, which is packed: */
- png_read_row(png_ptr, png_voidcast(png_bytep,
- display->local_row), NULL);
- inrow = png_voidcast(png_const_uint_16p, display->local_row);
-
- /* Now do the pre-multiplication on each pixel in this row.
- */
- outrow += startx;
- for (; outrow < end_row; outrow += stepx)
- {
- png_uint_32 component = inrow[0];
- png_uint_16 alpha = inrow[1];
-
- if (alpha > 0) /* else 0 */
- {
- if (alpha < 65535) /* else just use component */
- {
- component *= alpha;
- component += 32767;
- component /= 65535;
- }
- }
-
- else
- component = 0;
-
- outrow[swap_alpha] = (png_uint_16)component;
- if (preserve_alpha)
- outrow[1 ^ swap_alpha] = alpha;
-
- inrow += 2; /* components and alpha channel */
- }
- }
- }
- }
- break;
- }
-
- return 1;
-}
-
-/* The guts of png_image_finish_read as a png_safe_execute callback. */
-static int
-png_image_read_direct(png_voidp argument)
-{
- png_image_read_control *display = png_voidcast(png_image_read_control*,
- argument);
- png_imagep image = display->image;
- png_structrp png_ptr = image->opaque->png_ptr;
- png_inforp info_ptr = image->opaque->info_ptr;
-
- png_uint_32 format = image->format;
- int linear = (format & PNG_FORMAT_FLAG_LINEAR) != 0;
- int do_local_compose = 0;
- int do_local_background = 0; /* to avoid double gamma correction bug */
- int passes = 0;
-
- /* Add transforms to ensure the correct output format is produced then check
- * that the required implementation support is there. Always expand; always
- * need 8 bits minimum, no palette and expanded tRNS.
- */
- png_set_expand(png_ptr);
-
- /* Now check the format to see if it was modified. */
- {
- png_uint_32 base_format = png_image_format(png_ptr) &
- ~PNG_FORMAT_FLAG_COLORMAP /* removed by png_set_expand */;
- png_uint_32 change = format ^ base_format;
- png_fixed_point output_gamma;
- int mode; /* alpha mode */
-
- /* Do this first so that we have a record if rgb to gray is happening. */
- if (change & PNG_FORMAT_FLAG_COLOR)
- {
- /* gray<->color transformation required. */
- if (format & PNG_FORMAT_FLAG_COLOR)
- png_set_gray_to_rgb(png_ptr);
-
- else
- {
- /* libpng can't do both rgb to gray and
- * background/pre-multiplication if there is also significant gamma
- * correction, because both operations require linear colors and
- * the code only supports one transform doing the gamma correction.
- * Handle this by doing the pre-multiplication or background
- * operation in this code, if necessary.
- *
- * TODO: fix this by rewriting pngrtran.c (!)
- *
- * For the moment (given that fixing this in pngrtran.c is an
- * enormous change) 'do_local_background' is used to indicate that
- * the problem exists.
- */
- if (base_format & PNG_FORMAT_FLAG_ALPHA)
- do_local_background = 1/*maybe*/;
-
- png_set_rgb_to_gray_fixed(png_ptr, PNG_ERROR_ACTION_NONE,
- PNG_RGB_TO_GRAY_DEFAULT, PNG_RGB_TO_GRAY_DEFAULT);
- }
-
- change &= ~PNG_FORMAT_FLAG_COLOR;
- }
-
- /* Set the gamma appropriately, linear for 16-bit input, sRGB otherwise.
- */
- {
- png_fixed_point input_gamma_default;
-
- if ((base_format & PNG_FORMAT_FLAG_LINEAR) &&
- (image->flags & PNG_IMAGE_FLAG_16BIT_sRGB) == 0)
- input_gamma_default = PNG_GAMMA_LINEAR;
- else
- input_gamma_default = PNG_DEFAULT_sRGB;
-
- /* Call png_set_alpha_mode to set the default for the input gamma; the
- * output gamma is set by a second call below.
- */
- png_set_alpha_mode_fixed(png_ptr, PNG_ALPHA_PNG, input_gamma_default);
- }
-
- if (linear)
- {
- /* If there *is* an alpha channel in the input it must be multiplied
- * out; use PNG_ALPHA_STANDARD, otherwise just use PNG_ALPHA_PNG.
- */
- if (base_format & PNG_FORMAT_FLAG_ALPHA)
- mode = PNG_ALPHA_STANDARD; /* associated alpha */
-
- else
- mode = PNG_ALPHA_PNG;
-
- output_gamma = PNG_GAMMA_LINEAR;
- }
-
- else
- {
- mode = PNG_ALPHA_PNG;
- output_gamma = PNG_DEFAULT_sRGB;
- }
-
- /* If 'do_local_background' is set check for the presence of gamma
- * correction; this is part of the work-round for the libpng bug
- * described above.
- *
- * TODO: fix libpng and remove this.
- */
- if (do_local_background)
- {
- png_fixed_point gtest;
-
- /* This is 'png_gamma_threshold' from pngrtran.c; the test used for
- * gamma correction, the screen gamma hasn't been set on png_struct
- * yet; it's set below. png_struct::gamma, however, is set to the
- * final value.
- */
- if (png_muldiv(>est, output_gamma, png_ptr->colorspace.gamma,
- PNG_FP_1) && !png_gamma_significant(gtest))
- do_local_background = 0;
-
- else if (mode == PNG_ALPHA_STANDARD)
- {
- do_local_background = 2/*required*/;
- mode = PNG_ALPHA_PNG; /* prevent libpng doing it */
- }
-
- /* else leave as 1 for the checks below */
- }
-
- /* If the bit-depth changes then handle that here. */
- if (change & PNG_FORMAT_FLAG_LINEAR)
- {
- if (linear /*16-bit output*/)
- png_set_expand_16(png_ptr);
-
- else /* 8-bit output */
- png_set_scale_16(png_ptr);
-
- change &= ~PNG_FORMAT_FLAG_LINEAR;
- }
-
- /* Now the background/alpha channel changes. */
- if (change & PNG_FORMAT_FLAG_ALPHA)
- {
- /* Removing an alpha channel requires composition for the 8-bit
- * formats; for the 16-bit it is already done, above, by the
- * pre-multiplication and the channel just needs to be stripped.
- */
- if (base_format & PNG_FORMAT_FLAG_ALPHA)
- {
- /* If RGB->gray is happening the alpha channel must be left and the
- * operation completed locally.
- *
- * TODO: fix libpng and remove this.
- */
- if (do_local_background)
- do_local_background = 2/*required*/;
-
- /* 16-bit output: just remove the channel */
- else if (linear) /* compose on black (well, pre-multiply) */
- png_set_strip_alpha(png_ptr);
-
- /* 8-bit output: do an appropriate compose */
- else if (display->background != NULL)
- {
- png_color_16 c;
-
- c.index = 0; /*unused*/
- c.red = display->background->red;
- c.green = display->background->green;
- c.blue = display->background->blue;
- c.gray = display->background->green;
-
- /* This is always an 8-bit sRGB value, using the 'green' channel
- * for gray is much better than calculating the luminance here;
- * we can get off-by-one errors in that calculation relative to
- * the app expectations and that will show up in transparent
- * pixels.
- */
- png_set_background_fixed(png_ptr, &c,
- PNG_BACKGROUND_GAMMA_SCREEN, 0/*need_expand*/,
- 0/*gamma: not used*/);
- }
-
- else /* compose on row: implemented below. */
- {
- do_local_compose = 1;
- /* This leaves the alpha channel in the output, so it has to be
- * removed by the code below. Set the encoding to the 'OPTIMIZE'
- * one so the code only has to hack on the pixels that require
- * composition.
- */
- mode = PNG_ALPHA_OPTIMIZED;
- }
- }
-
- else /* output needs an alpha channel */
- {
- /* This is tricky because it happens before the swap operation has
- * been accomplished; however, the swap does *not* swap the added
- * alpha channel (weird API), so it must be added in the correct
- * place.
- */
- png_uint_32 filler; /* opaque filler */
- int where;
-
- if (linear)
- filler = 65535;
-
- else
- filler = 255;
-
-# ifdef PNG_FORMAT_AFIRST_SUPPORTED
- if (format & PNG_FORMAT_FLAG_AFIRST)
- {
- where = PNG_FILLER_BEFORE;
- change &= ~PNG_FORMAT_FLAG_AFIRST;
- }
-
- else
-# endif
- where = PNG_FILLER_AFTER;
-
- png_set_add_alpha(png_ptr, filler, where);
- }
-
- /* This stops the (irrelevant) call to swap_alpha below. */
- change &= ~PNG_FORMAT_FLAG_ALPHA;
- }
-
- /* Now set the alpha mode correctly; this is always done, even if there is
- * no alpha channel in either the input or the output because it correctly
- * sets the output gamma.
- */
- png_set_alpha_mode_fixed(png_ptr, mode, output_gamma);
-
-# ifdef PNG_FORMAT_BGR_SUPPORTED
- if (change & PNG_FORMAT_FLAG_BGR)
- {
- /* Check only the output format; PNG is never BGR; don't do this if
- * the output is gray, but fix up the 'format' value in that case.
- */
- if (format & PNG_FORMAT_FLAG_COLOR)
- png_set_bgr(png_ptr);
-
- else
- format &= ~PNG_FORMAT_FLAG_BGR;
-
- change &= ~PNG_FORMAT_FLAG_BGR;
- }
-# endif
-
-# ifdef PNG_FORMAT_AFIRST_SUPPORTED
- if (change & PNG_FORMAT_FLAG_AFIRST)
- {
- /* Only relevant if there is an alpha channel - it's particularly
- * important to handle this correctly because do_local_compose may
- * be set above and then libpng will keep the alpha channel for this
- * code to remove.
- */
- if (format & PNG_FORMAT_FLAG_ALPHA)
- {
- /* Disable this if doing a local background,
- * TODO: remove this when local background is no longer required.
- */
- if (do_local_background != 2)
- png_set_swap_alpha(png_ptr);
- }
-
- else
- format &= ~PNG_FORMAT_FLAG_AFIRST;
-
- change &= ~PNG_FORMAT_FLAG_AFIRST;
- }
-# endif
-
- /* If the *output* is 16-bit then we need to check for a byte-swap on this
- * architecture.
- */
- if (linear)
- {
- PNG_CONST png_uint_16 le = 0x0001;
-
- if (*(png_const_bytep)&le)
- png_set_swap(png_ptr);
- }
-
- /* If change is not now 0 some transformation is missing - error out. */
- if (change)
- png_error(png_ptr, "png_read_image: unsupported transformation");
- }
-
- PNG_SKIP_CHUNKS(png_ptr);
-
- /* Update the 'info' structure and make sure the result is as required; first
- * make sure to turn on the interlace handling if it will be required
- * (because it can't be turned on *after* the call to png_read_update_info!)
- *
- * TODO: remove the do_local_background fixup below.
- */
- if (!do_local_compose && do_local_background != 2)
- passes = png_set_interlace_handling(png_ptr);
-
- png_read_update_info(png_ptr, info_ptr);
-
- {
- png_uint_32 info_format = 0;
-
- if (info_ptr->color_type & PNG_COLOR_MASK_COLOR)
- info_format |= PNG_FORMAT_FLAG_COLOR;
-
- if (info_ptr->color_type & PNG_COLOR_MASK_ALPHA)
- {
- /* do_local_compose removes this channel below. */
- if (!do_local_compose)
- {
- /* do_local_background does the same if required. */
- if (do_local_background != 2 ||
- (format & PNG_FORMAT_FLAG_ALPHA) != 0)
- info_format |= PNG_FORMAT_FLAG_ALPHA;
- }
- }
-
- else if (do_local_compose) /* internal error */
- png_error(png_ptr, "png_image_read: alpha channel lost");
-
- if (info_ptr->bit_depth == 16)
- info_format |= PNG_FORMAT_FLAG_LINEAR;
-
-# ifdef PNG_FORMAT_BGR_SUPPORTED
- if (png_ptr->transformations & PNG_BGR)
- info_format |= PNG_FORMAT_FLAG_BGR;
-# endif
-
-# ifdef PNG_FORMAT_AFIRST_SUPPORTED
- if (do_local_background == 2)
- {
- if (format & PNG_FORMAT_FLAG_AFIRST)
- info_format |= PNG_FORMAT_FLAG_AFIRST;
- }
-
- if ((png_ptr->transformations & PNG_SWAP_ALPHA) != 0 ||
- ((png_ptr->transformations & PNG_ADD_ALPHA) != 0 &&
- (png_ptr->flags & PNG_FLAG_FILLER_AFTER) == 0))
- {
- if (do_local_background == 2)
- png_error(png_ptr, "unexpected alpha swap transformation");
-
- info_format |= PNG_FORMAT_FLAG_AFIRST;
- }
-# endif
-
- /* This is actually an internal error. */
- if (info_format != format)
- png_error(png_ptr, "png_read_image: invalid transformations");
- }
-
- /* Now read the rows. If do_local_compose is set then it is necessary to use
- * a local row buffer. The output will be GA, RGBA or BGRA and must be
- * converted to G, RGB or BGR as appropriate. The 'local_row' member of the
- * display acts as a flag.
- */
- {
- png_voidp first_row = display->buffer;
- ptrdiff_t row_bytes = display->row_stride;
-
- if (linear)
- row_bytes *= 2;
-
- /* The following expression is designed to work correctly whether it gives
- * a signed or an unsigned result.
- */
- if (row_bytes < 0)
- {
- char *ptr = png_voidcast(char*, first_row);
- ptr += (image->height-1) * (-row_bytes);
- first_row = png_voidcast(png_voidp, ptr);
- }
-
- display->first_row = first_row;
- display->row_bytes = row_bytes;
- }
-
- if (do_local_compose)
- {
- int result;
- png_voidp row = png_malloc(png_ptr, png_get_rowbytes(png_ptr, info_ptr));
-
- display->local_row = row;
- result = png_safe_execute(image, png_image_read_composite, display);
- display->local_row = NULL;
- png_free(png_ptr, row);
-
- return result;
- }
-
- else if (do_local_background == 2)
- {
- int result;
- png_voidp row = png_malloc(png_ptr, png_get_rowbytes(png_ptr, info_ptr));
-
- display->local_row = row;
- result = png_safe_execute(image, png_image_read_background, display);
- display->local_row = NULL;
- png_free(png_ptr, row);
-
- return result;
- }
-
- else
- {
- png_alloc_size_t row_bytes = display->row_bytes;
-
- while (--passes >= 0)
- {
- png_uint_32 y = image->height;
- png_bytep row = png_voidcast(png_bytep, display->first_row);
-
- while (y-- > 0)
- {
- png_read_row(png_ptr, row, NULL);
- row += row_bytes;
- }
- }
-
- return 1;
- }
-}
-
-int PNGAPI
-png_image_finish_read(png_imagep image, png_const_colorp background,
- void *buffer, png_int_32 row_stride, void *colormap)
-{
- if (image != NULL && image->version == PNG_IMAGE_VERSION)
- {
- png_uint_32 check;
-
- if (row_stride == 0)
- row_stride = PNG_IMAGE_ROW_STRIDE(*image);
-
- if (row_stride < 0)
- check = -row_stride;
-
- else
- check = row_stride;
-
- if (image->opaque != NULL && buffer != NULL &&
- check >= PNG_IMAGE_ROW_STRIDE(*image))
- {
- if ((image->format & PNG_FORMAT_FLAG_COLORMAP) == 0 ||
- (image->colormap_entries > 0 && colormap != NULL))
- {
- int result;
- png_image_read_control display;
-
- memset(&display, 0, (sizeof display));
- display.image = image;
- display.buffer = buffer;
- display.row_stride = row_stride;
- display.colormap = colormap;
- display.background = background;
- display.local_row = NULL;
-
- /* Choose the correct 'end' routine; for the color-map case all the
- * setup has already been done.
- */
- if (image->format & PNG_FORMAT_FLAG_COLORMAP)
- result =
- png_safe_execute(image, png_image_read_colormap, &display) &&
- png_safe_execute(image, png_image_read_colormapped, &display);
-
- else
- result =
- png_safe_execute(image, png_image_read_direct, &display);
-
- png_image_free(image);
- return result;
- }
-
- else
- return png_image_error(image,
- "png_image_finish_read[color-map]: no color-map");
- }
-
- else
- return png_image_error(image,
- "png_image_finish_read: invalid argument");
- }
-
- else if (image != NULL)
- return png_image_error(image,
- "png_image_finish_read: damaged PNG_IMAGE_VERSION");
-
- return 0;
-}
-
-#endif /* PNG_SIMPLIFIED_READ_SUPPORTED */
-#endif /* PNG_READ_SUPPORTED */
+
+/* pngread.c - read a PNG file
+ *
+ * Last changed in libpng 1.6.17 [March 26, 2015]
+ * Copyright (c) 1998-2015 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ * This file contains routines that an application calls directly to
+ * read a PNG file or stream.
+ */
+
+#include "pngpriv.h"
+#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) && defined(PNG_STDIO_SUPPORTED)
+# include <errno.h>
+#endif
+
+#ifdef PNG_READ_SUPPORTED
+
+/* Create a PNG structure for reading, and allocate any memory needed. */
+PNG_FUNCTION(png_structp,PNGAPI
+png_create_read_struct,(png_const_charp user_png_ver, png_voidp error_ptr,
+ png_error_ptr error_fn, png_error_ptr warn_fn),PNG_ALLOCATED)
+{
+#ifndef PNG_USER_MEM_SUPPORTED
+ png_structp png_ptr = png_create_png_struct(user_png_ver, error_ptr,
+ error_fn, warn_fn, NULL, NULL, NULL);
+#else
+ return png_create_read_struct_2(user_png_ver, error_ptr, error_fn,
+ warn_fn, NULL, NULL, NULL);
+}
+
+/* Alternate create PNG structure for reading, and allocate any memory
+ * needed.
+ */
+PNG_FUNCTION(png_structp,PNGAPI
+png_create_read_struct_2,(png_const_charp user_png_ver, png_voidp error_ptr,
+ png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
+ png_malloc_ptr malloc_fn, png_free_ptr free_fn),PNG_ALLOCATED)
+{
+ png_structp png_ptr = png_create_png_struct(user_png_ver, error_ptr,
+ error_fn, warn_fn, mem_ptr, malloc_fn, free_fn);
+#endif /* USER_MEM */
+
+ if (png_ptr != NULL)
+ {
+ png_ptr->mode = PNG_IS_READ_STRUCT;
+
+ /* Added in libpng-1.6.0; this can be used to detect a read structure if
+ * required (it will be zero in a write structure.)
+ */
+# ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+ png_ptr->IDAT_read_size = PNG_IDAT_READ_SIZE;
+# endif
+
+# ifdef PNG_BENIGN_READ_ERRORS_SUPPORTED
+ png_ptr->flags |= PNG_FLAG_BENIGN_ERRORS_WARN;
+
+ /* In stable builds only warn if an application error can be completely
+ * handled.
+ */
+# if PNG_RELEASE_BUILD
+ png_ptr->flags |= PNG_FLAG_APP_WARNINGS_WARN;
+# endif
+# endif
+
+ /* TODO: delay this, it can be done in png_init_io (if the app doesn't
+ * do it itself) avoiding setting the default function if it is not
+ * required.
+ */
+ png_set_read_fn(png_ptr, NULL, NULL);
+ }
+
+ return png_ptr;
+}
+
+
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+/* Read the information before the actual image data. This has been
+ * changed in v0.90 to allow reading a file that already has the magic
+ * bytes read from the stream. You can tell libpng how many bytes have
+ * been read from the beginning of the stream (up to the maximum of 8)
+ * via png_set_sig_bytes(), and we will only check the remaining bytes
+ * here. The application can then have access to the signature bytes we
+ * read if it is determined that this isn't a valid PNG file.
+ */
+void PNGAPI
+png_read_info(png_structrp png_ptr, png_inforp info_ptr)
+{
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+ int keep;
+#endif
+
+ png_debug(1, "in png_read_info");
+
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+ /* Read and check the PNG file signature. */
+ png_read_sig(png_ptr, info_ptr);
+
+ for (;;)
+ {
+ png_uint_32 length = png_read_chunk_header(png_ptr);
+ png_uint_32 chunk_name = png_ptr->chunk_name;
+
+ /* IDAT logic needs to happen here to simplify getting the two flags
+ * right.
+ */
+ if (chunk_name == png_IDAT)
+ {
+ if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
+ png_chunk_error(png_ptr, "Missing IHDR before IDAT");
+
+ else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
+ (png_ptr->mode & PNG_HAVE_PLTE) == 0)
+ png_chunk_error(png_ptr, "Missing PLTE before IDAT");
+
+ else if ((png_ptr->mode & PNG_AFTER_IDAT) != 0)
+ png_chunk_benign_error(png_ptr, "Too many IDATs found");
+
+ png_ptr->mode |= PNG_HAVE_IDAT;
+ }
+
+ else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0)
+ png_ptr->mode |= PNG_AFTER_IDAT;
+
+ /* This should be a binary subdivision search or a hash for
+ * matching the chunk name rather than a linear search.
+ */
+ if (chunk_name == png_IHDR)
+ png_handle_IHDR(png_ptr, info_ptr, length);
+
+ else if (chunk_name == png_IEND)
+ png_handle_IEND(png_ptr, info_ptr, length);
+
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+ else if ((keep = png_chunk_unknown_handling(png_ptr, chunk_name)) != 0)
+ {
+ png_handle_unknown(png_ptr, info_ptr, length, keep);
+
+ if (chunk_name == png_PLTE)
+ png_ptr->mode |= PNG_HAVE_PLTE;
+
+ else if (chunk_name == png_IDAT)
+ {
+ png_ptr->idat_size = 0; /* It has been consumed */
+ break;
+ }
+ }
+#endif
+ else if (chunk_name == png_PLTE)
+ png_handle_PLTE(png_ptr, info_ptr, length);
+
+ else if (chunk_name == png_IDAT)
+ {
+ png_ptr->idat_size = length;
+ break;
+ }
+
+#ifdef PNG_READ_bKGD_SUPPORTED
+ else if (chunk_name == png_bKGD)
+ png_handle_bKGD(png_ptr, info_ptr, length);
+#endif
+
+#ifdef PNG_READ_cHRM_SUPPORTED
+ else if (chunk_name == png_cHRM)
+ png_handle_cHRM(png_ptr, info_ptr, length);
+#endif
+
+#ifdef PNG_READ_gAMA_SUPPORTED
+ else if (chunk_name == png_gAMA)
+ png_handle_gAMA(png_ptr, info_ptr, length);
+#endif
+
+#ifdef PNG_READ_hIST_SUPPORTED
+ else if (chunk_name == png_hIST)
+ png_handle_hIST(png_ptr, info_ptr, length);
+#endif
+
+#ifdef PNG_READ_oFFs_SUPPORTED
+ else if (chunk_name == png_oFFs)
+ png_handle_oFFs(png_ptr, info_ptr, length);
+#endif
+
+#ifdef PNG_READ_pCAL_SUPPORTED
+ else if (chunk_name == png_pCAL)
+ png_handle_pCAL(png_ptr, info_ptr, length);
+#endif
+
+#ifdef PNG_READ_sCAL_SUPPORTED
+ else if (chunk_name == png_sCAL)
+ png_handle_sCAL(png_ptr, info_ptr, length);
+#endif
+
+#ifdef PNG_READ_pHYs_SUPPORTED
+ else if (chunk_name == png_pHYs)
+ png_handle_pHYs(png_ptr, info_ptr, length);
+#endif
+
+#ifdef PNG_READ_sBIT_SUPPORTED
+ else if (chunk_name == png_sBIT)
+ png_handle_sBIT(png_ptr, info_ptr, length);
+#endif
+
+#ifdef PNG_READ_sRGB_SUPPORTED
+ else if (chunk_name == png_sRGB)
+ png_handle_sRGB(png_ptr, info_ptr, length);
+#endif
+
+#ifdef PNG_READ_iCCP_SUPPORTED
+ else if (chunk_name == png_iCCP)
+ png_handle_iCCP(png_ptr, info_ptr, length);
+#endif
+
+#ifdef PNG_READ_sPLT_SUPPORTED
+ else if (chunk_name == png_sPLT)
+ png_handle_sPLT(png_ptr, info_ptr, length);
+#endif
+
+#ifdef PNG_READ_tEXt_SUPPORTED
+ else if (chunk_name == png_tEXt)
+ png_handle_tEXt(png_ptr, info_ptr, length);
+#endif
+
+#ifdef PNG_READ_tIME_SUPPORTED
+ else if (chunk_name == png_tIME)
+ png_handle_tIME(png_ptr, info_ptr, length);
+#endif
+
+#ifdef PNG_READ_tRNS_SUPPORTED
+ else if (chunk_name == png_tRNS)
+ png_handle_tRNS(png_ptr, info_ptr, length);
+#endif
+
+#ifdef PNG_READ_zTXt_SUPPORTED
+ else if (chunk_name == png_zTXt)
+ png_handle_zTXt(png_ptr, info_ptr, length);
+#endif
+
+#ifdef PNG_READ_iTXt_SUPPORTED
+ else if (chunk_name == png_iTXt)
+ png_handle_iTXt(png_ptr, info_ptr, length);
+#endif
+
+ else
+ png_handle_unknown(png_ptr, info_ptr, length,
+ PNG_HANDLE_CHUNK_AS_DEFAULT);
+ }
+}
+#endif /* SEQUENTIAL_READ */
+
+/* Optional call to update the users info_ptr structure */
+void PNGAPI
+png_read_update_info(png_structrp png_ptr, png_inforp info_ptr)
+{
+ png_debug(1, "in png_read_update_info");
+
+ if (png_ptr != NULL)
+ {
+ if ((png_ptr->flags & PNG_FLAG_ROW_INIT) == 0)
+ {
+ png_read_start_row(png_ptr);
+
+# ifdef PNG_READ_TRANSFORMS_SUPPORTED
+ png_read_transform_info(png_ptr, info_ptr);
+# else
+ PNG_UNUSED(info_ptr)
+# endif
+ }
+
+ /* New in 1.6.0 this avoids the bug of doing the initializations twice */
+ else
+ png_app_error(png_ptr,
+ "png_read_update_info/png_start_read_image: duplicate call");
+ }
+}
+
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+/* Initialize palette, background, etc, after transformations
+ * are set, but before any reading takes place. This allows
+ * the user to obtain a gamma-corrected palette, for example.
+ * If the user doesn't call this, we will do it ourselves.
+ */
+void PNGAPI
+png_start_read_image(png_structrp png_ptr)
+{
+ png_debug(1, "in png_start_read_image");
+
+ if (png_ptr != NULL)
+ {
+ if ((png_ptr->flags & PNG_FLAG_ROW_INIT) == 0)
+ png_read_start_row(png_ptr);
+
+ /* New in 1.6.0 this avoids the bug of doing the initializations twice */
+ else
+ png_app_error(png_ptr,
+ "png_start_read_image/png_read_update_info: duplicate call");
+ }
+}
+#endif /* SEQUENTIAL_READ */
+
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+/* Undoes intrapixel differencing,
+ * NOTE: this is apparently only supported in the 'sequential' reader.
+ */
+static void
+png_do_read_intrapixel(png_row_infop row_info, png_bytep row)
+{
+ png_debug(1, "in png_do_read_intrapixel");
+
+ if (
+ (row_info->color_type & PNG_COLOR_MASK_COLOR) != 0)
+ {
+ int bytes_per_pixel;
+ png_uint_32 row_width = row_info->width;
+
+ if (row_info->bit_depth == 8)
+ {
+ png_bytep rp;
+ png_uint_32 i;
+
+ if (row_info->color_type == PNG_COLOR_TYPE_RGB)
+ bytes_per_pixel = 3;
+
+ else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+ bytes_per_pixel = 4;
+
+ else
+ return;
+
+ for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel)
+ {
+ *(rp) = (png_byte)((256 + *rp + *(rp + 1)) & 0xff);
+ *(rp+2) = (png_byte)((256 + *(rp + 2) + *(rp + 1)) & 0xff);
+ }
+ }
+ else if (row_info->bit_depth == 16)
+ {
+ png_bytep rp;
+ png_uint_32 i;
+
+ if (row_info->color_type == PNG_COLOR_TYPE_RGB)
+ bytes_per_pixel = 6;
+
+ else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+ bytes_per_pixel = 8;
+
+ else
+ return;
+
+ for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel)
+ {
+ png_uint_32 s0 = (*(rp ) << 8) | *(rp + 1);
+ png_uint_32 s1 = (*(rp + 2) << 8) | *(rp + 3);
+ png_uint_32 s2 = (*(rp + 4) << 8) | *(rp + 5);
+ png_uint_32 red = (s0 + s1 + 65536) & 0xffff;
+ png_uint_32 blue = (s2 + s1 + 65536) & 0xffff;
+ *(rp ) = (png_byte)((red >> 8) & 0xff);
+ *(rp + 1) = (png_byte)(red & 0xff);
+ *(rp + 4) = (png_byte)((blue >> 8) & 0xff);
+ *(rp + 5) = (png_byte)(blue & 0xff);
+ }
+ }
+ }
+}
+#endif /* MNG_FEATURES */
+
+void PNGAPI
+png_read_row(png_structrp png_ptr, png_bytep row, png_bytep dsp_row)
+{
+ png_row_info row_info;
+
+ if (png_ptr == NULL)
+ return;
+
+ png_debug2(1, "in png_read_row (row %lu, pass %d)",
+ (unsigned long)png_ptr->row_number, png_ptr->pass);
+
+ /* png_read_start_row sets the information (in particular iwidth) for this
+ * interlace pass.
+ */
+ if ((png_ptr->flags & PNG_FLAG_ROW_INIT) == 0)
+ png_read_start_row(png_ptr);
+
+ /* 1.5.6: row_info moved out of png_struct to a local here. */
+ row_info.width = png_ptr->iwidth; /* NOTE: width of current interlaced row */
+ row_info.color_type = png_ptr->color_type;
+ row_info.bit_depth = png_ptr->bit_depth;
+ row_info.channels = png_ptr->channels;
+ row_info.pixel_depth = png_ptr->pixel_depth;
+ row_info.rowbytes = PNG_ROWBYTES(row_info.pixel_depth, row_info.width);
+
+#ifdef PNG_WARNINGS_SUPPORTED
+ if (png_ptr->row_number == 0 && png_ptr->pass == 0)
+ {
+ /* Check for transforms that have been set but were defined out */
+#if defined(PNG_WRITE_INVERT_SUPPORTED) && !defined(PNG_READ_INVERT_SUPPORTED)
+ if ((png_ptr->transformations & PNG_INVERT_MONO) != 0)
+ png_warning(png_ptr, "PNG_READ_INVERT_SUPPORTED is not defined");
+#endif
+
+#if defined(PNG_WRITE_FILLER_SUPPORTED) && !defined(PNG_READ_FILLER_SUPPORTED)
+ if ((png_ptr->transformations & PNG_FILLER) != 0)
+ png_warning(png_ptr, "PNG_READ_FILLER_SUPPORTED is not defined");
+#endif
+
+#if defined(PNG_WRITE_PACKSWAP_SUPPORTED) && \
+ !defined(PNG_READ_PACKSWAP_SUPPORTED)
+ if ((png_ptr->transformations & PNG_PACKSWAP) != 0)
+ png_warning(png_ptr, "PNG_READ_PACKSWAP_SUPPORTED is not defined");
+#endif
+
+#if defined(PNG_WRITE_PACK_SUPPORTED) && !defined(PNG_READ_PACK_SUPPORTED)
+ if ((png_ptr->transformations & PNG_PACK) != 0)
+ png_warning(png_ptr, "PNG_READ_PACK_SUPPORTED is not defined");
+#endif
+
+#if defined(PNG_WRITE_SHIFT_SUPPORTED) && !defined(PNG_READ_SHIFT_SUPPORTED)
+ if ((png_ptr->transformations & PNG_SHIFT) != 0)
+ png_warning(png_ptr, "PNG_READ_SHIFT_SUPPORTED is not defined");
+#endif
+
+#if defined(PNG_WRITE_BGR_SUPPORTED) && !defined(PNG_READ_BGR_SUPPORTED)
+ if ((png_ptr->transformations & PNG_BGR) != 0)
+ png_warning(png_ptr, "PNG_READ_BGR_SUPPORTED is not defined");
+#endif
+
+#if defined(PNG_WRITE_SWAP_SUPPORTED) && !defined(PNG_READ_SWAP_SUPPORTED)
+ if ((png_ptr->transformations & PNG_SWAP_BYTES) != 0)
+ png_warning(png_ptr, "PNG_READ_SWAP_SUPPORTED is not defined");
+#endif
+ }
+#endif /* WARNINGS */
+
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+ /* If interlaced and we do not need a new row, combine row and return.
+ * Notice that the pixels we have from previous rows have been transformed
+ * already; we can only combine like with like (transformed or
+ * untransformed) and, because of the libpng API for interlaced images, this
+ * means we must transform before de-interlacing.
+ */
+ if (png_ptr->interlaced != 0 &&
+ (png_ptr->transformations & PNG_INTERLACE) != 0)
+ {
+ switch (png_ptr->pass)
+ {
+ case 0:
+ if (png_ptr->row_number & 0x07)
+ {
+ if (dsp_row != NULL)
+ png_combine_row(png_ptr, dsp_row, 1/*display*/);
+ png_read_finish_row(png_ptr);
+ return;
+ }
+ break;
+
+ case 1:
+ if ((png_ptr->row_number & 0x07) || png_ptr->width < 5)
+ {
+ if (dsp_row != NULL)
+ png_combine_row(png_ptr, dsp_row, 1/*display*/);
+
+ png_read_finish_row(png_ptr);
+ return;
+ }
+ break;
+
+ case 2:
+ if ((png_ptr->row_number & 0x07) != 4)
+ {
+ if (dsp_row != NULL && (png_ptr->row_number & 4))
+ png_combine_row(png_ptr, dsp_row, 1/*display*/);
+
+ png_read_finish_row(png_ptr);
+ return;
+ }
+ break;
+
+ case 3:
+ if ((png_ptr->row_number & 3) || png_ptr->width < 3)
+ {
+ if (dsp_row != NULL)
+ png_combine_row(png_ptr, dsp_row, 1/*display*/);
+
+ png_read_finish_row(png_ptr);
+ return;
+ }
+ break;
+
+ case 4:
+ if ((png_ptr->row_number & 3) != 2)
+ {
+ if (dsp_row != NULL && (png_ptr->row_number & 2))
+ png_combine_row(png_ptr, dsp_row, 1/*display*/);
+
+ png_read_finish_row(png_ptr);
+ return;
+ }
+ break;
+
+ case 5:
+ if ((png_ptr->row_number & 1) || png_ptr->width < 2)
+ {
+ if (dsp_row != NULL)
+ png_combine_row(png_ptr, dsp_row, 1/*display*/);
+
+ png_read_finish_row(png_ptr);
+ return;
+ }
+ break;
+
+ default:
+ case 6:
+ if ((png_ptr->row_number & 1) == 0)
+ {
+ png_read_finish_row(png_ptr);
+ return;
+ }
+ break;
+ }
+ }
+#endif
+
+ if ((png_ptr->mode & PNG_HAVE_IDAT) == 0)
+ png_error(png_ptr, "Invalid attempt to read row data");
+
+ /* Fill the row with IDAT data: */
+ png_read_IDAT_data(png_ptr, png_ptr->row_buf, row_info.rowbytes + 1);
+
+ if (png_ptr->row_buf[0] > PNG_FILTER_VALUE_NONE)
+ {
+ if (png_ptr->row_buf[0] < PNG_FILTER_VALUE_LAST)
+ png_read_filter_row(png_ptr, &row_info, png_ptr->row_buf + 1,
+ png_ptr->prev_row + 1, png_ptr->row_buf[0]);
+ else
+ png_error(png_ptr, "bad adaptive filter value");
+ }
+
+ /* libpng 1.5.6: the following line was copying png_ptr->rowbytes before
+ * 1.5.6, while the buffer really is this big in current versions of libpng
+ * it may not be in the future, so this was changed just to copy the
+ * interlaced count:
+ */
+ memcpy(png_ptr->prev_row, png_ptr->row_buf, row_info.rowbytes + 1);
+
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+ if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) != 0 &&
+ (png_ptr->filter_type == PNG_INTRAPIXEL_DIFFERENCING))
+ {
+ /* Intrapixel differencing */
+ png_do_read_intrapixel(&row_info, png_ptr->row_buf + 1);
+ }
+#endif
+
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
+ if (png_ptr->transformations)
+ png_do_read_transformations(png_ptr, &row_info);
+#endif
+
+ /* The transformed pixel depth should match the depth now in row_info. */
+ if (png_ptr->transformed_pixel_depth == 0)
+ {
+ png_ptr->transformed_pixel_depth = row_info.pixel_depth;
+ if (row_info.pixel_depth > png_ptr->maximum_pixel_depth)
+ png_error(png_ptr, "sequential row overflow");
+ }
+
+ else if (png_ptr->transformed_pixel_depth != row_info.pixel_depth)
+ png_error(png_ptr, "internal sequential row size calculation error");
+
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+ /* Expand interlaced rows to full size */
+ if (png_ptr->interlaced != 0 &&
+ (png_ptr->transformations & PNG_INTERLACE) != 0)
+ {
+ if (png_ptr->pass < 6)
+ png_do_read_interlace(&row_info, png_ptr->row_buf + 1, png_ptr->pass,
+ png_ptr->transformations);
+
+ if (dsp_row != NULL)
+ png_combine_row(png_ptr, dsp_row, 1/*display*/);
+
+ if (row != NULL)
+ png_combine_row(png_ptr, row, 0/*row*/);
+ }
+
+ else
+#endif
+ {
+ if (row != NULL)
+ png_combine_row(png_ptr, row, -1/*ignored*/);
+
+ if (dsp_row != NULL)
+ png_combine_row(png_ptr, dsp_row, -1/*ignored*/);
+ }
+ png_read_finish_row(png_ptr);
+
+ if (png_ptr->read_row_fn != NULL)
+ (*(png_ptr->read_row_fn))(png_ptr, png_ptr->row_number, png_ptr->pass);
+
+}
+#endif /* SEQUENTIAL_READ */
+
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+/* Read one or more rows of image data. If the image is interlaced,
+ * and png_set_interlace_handling() has been called, the rows need to
+ * contain the contents of the rows from the previous pass. If the
+ * image has alpha or transparency, and png_handle_alpha()[*] has been
+ * called, the rows contents must be initialized to the contents of the
+ * screen.
+ *
+ * "row" holds the actual image, and pixels are placed in it
+ * as they arrive. If the image is displayed after each pass, it will
+ * appear to "sparkle" in. "display_row" can be used to display a
+ * "chunky" progressive image, with finer detail added as it becomes
+ * available. If you do not want this "chunky" display, you may pass
+ * NULL for display_row. If you do not want the sparkle display, and
+ * you have not called png_handle_alpha(), you may pass NULL for rows.
+ * If you have called png_handle_alpha(), and the image has either an
+ * alpha channel or a transparency chunk, you must provide a buffer for
+ * rows. In this case, you do not have to provide a display_row buffer
+ * also, but you may. If the image is not interlaced, or if you have
+ * not called png_set_interlace_handling(), the display_row buffer will
+ * be ignored, so pass NULL to it.
+ *
+ * [*] png_handle_alpha() does not exist yet, as of this version of libpng
+ */
+
+void PNGAPI
+png_read_rows(png_structrp png_ptr, png_bytepp row,
+ png_bytepp display_row, png_uint_32 num_rows)
+{
+ png_uint_32 i;
+ png_bytepp rp;
+ png_bytepp dp;
+
+ png_debug(1, "in png_read_rows");
+
+ if (png_ptr == NULL)
+ return;
+
+ rp = row;
+ dp = display_row;
+ if (rp != NULL && dp != NULL)
+ for (i = 0; i < num_rows; i++)
+ {
+ png_bytep rptr = *rp++;
+ png_bytep dptr = *dp++;
+
+ png_read_row(png_ptr, rptr, dptr);
+ }
+
+ else if (rp != NULL)
+ for (i = 0; i < num_rows; i++)
+ {
+ png_bytep rptr = *rp;
+ png_read_row(png_ptr, rptr, NULL);
+ rp++;
+ }
+
+ else if (dp != NULL)
+ for (i = 0; i < num_rows; i++)
+ {
+ png_bytep dptr = *dp;
+ png_read_row(png_ptr, NULL, dptr);
+ dp++;
+ }
+}
+#endif /* SEQUENTIAL_READ */
+
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+/* Read the entire image. If the image has an alpha channel or a tRNS
+ * chunk, and you have called png_handle_alpha()[*], you will need to
+ * initialize the image to the current image that PNG will be overlaying.
+ * We set the num_rows again here, in case it was incorrectly set in
+ * png_read_start_row() by a call to png_read_update_info() or
+ * png_start_read_image() if png_set_interlace_handling() wasn't called
+ * prior to either of these functions like it should have been. You can
+ * only call this function once. If you desire to have an image for
+ * each pass of a interlaced image, use png_read_rows() instead.
+ *
+ * [*] png_handle_alpha() does not exist yet, as of this version of libpng
+ */
+void PNGAPI
+png_read_image(png_structrp png_ptr, png_bytepp image)
+{
+ png_uint_32 i, image_height;
+ int pass, j;
+ png_bytepp rp;
+
+ png_debug(1, "in png_read_image");
+
+ if (png_ptr == NULL)
+ return;
+
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+ if ((png_ptr->flags & PNG_FLAG_ROW_INIT) == 0)
+ {
+ pass = png_set_interlace_handling(png_ptr);
+ /* And make sure transforms are initialized. */
+ png_start_read_image(png_ptr);
+ }
+ else
+ {
+ if (png_ptr->interlaced != 0 &&
+ (png_ptr->transformations & PNG_INTERLACE) == 0)
+ {
+ /* Caller called png_start_read_image or png_read_update_info without
+ * first turning on the PNG_INTERLACE transform. We can fix this here,
+ * but the caller should do it!
+ */
+ png_warning(png_ptr, "Interlace handling should be turned on when "
+ "using png_read_image");
+ /* Make sure this is set correctly */
+ png_ptr->num_rows = png_ptr->height;
+ }
+
+ /* Obtain the pass number, which also turns on the PNG_INTERLACE flag in
+ * the above error case.
+ */
+ pass = png_set_interlace_handling(png_ptr);
+ }
+#else
+ if (png_ptr->interlaced)
+ png_error(png_ptr,
+ "Cannot read interlaced image -- interlace handler disabled");
+
+ pass = 1;
+#endif
+
+ image_height=png_ptr->height;
+
+ for (j = 0; j < pass; j++)
+ {
+ rp = image;
+ for (i = 0; i < image_height; i++)
+ {
+ png_read_row(png_ptr, *rp, NULL);
+ rp++;
+ }
+ }
+}
+#endif /* SEQUENTIAL_READ */
+
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+/* Read the end of the PNG file. Will not read past the end of the
+ * file, will verify the end is accurate, and will read any comments
+ * or time information at the end of the file, if info is not NULL.
+ */
+void PNGAPI
+png_read_end(png_structrp png_ptr, png_inforp info_ptr)
+{
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+ int keep;
+#endif
+
+ png_debug(1, "in png_read_end");
+
+ if (png_ptr == NULL)
+ return;
+
+ /* If png_read_end is called in the middle of reading the rows there may
+ * still be pending IDAT data and an owned zstream. Deal with this here.
+ */
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+ if (png_chunk_unknown_handling(png_ptr, png_IDAT) == 0)
+#endif
+ png_read_finish_IDAT(png_ptr);
+
+#ifdef PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED
+ /* Report invalid palette index; added at libng-1.5.10 */
+ if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
+ png_ptr->num_palette_max > png_ptr->num_palette)
+ png_benign_error(png_ptr, "Read palette index exceeding num_palette");
+#endif
+
+ do
+ {
+ png_uint_32 length = png_read_chunk_header(png_ptr);
+ png_uint_32 chunk_name = png_ptr->chunk_name;
+
+ if (chunk_name == png_IEND)
+ png_handle_IEND(png_ptr, info_ptr, length);
+
+ else if (chunk_name == png_IHDR)
+ png_handle_IHDR(png_ptr, info_ptr, length);
+
+ else if (info_ptr == NULL)
+ png_crc_finish(png_ptr, length);
+
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+ else if ((keep = png_chunk_unknown_handling(png_ptr, chunk_name)) != 0)
+ {
+ if (chunk_name == png_IDAT)
+ {
+ if ((length > 0) ||
+ (png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT) != 0)
+ png_benign_error(png_ptr, "Too many IDATs found");
+ }
+ png_handle_unknown(png_ptr, info_ptr, length, keep);
+ if (chunk_name == png_PLTE)
+ png_ptr->mode |= PNG_HAVE_PLTE;
+ }
+#endif
+
+ else if (chunk_name == png_IDAT)
+ {
+ /* Zero length IDATs are legal after the last IDAT has been
+ * read, but not after other chunks have been read.
+ */
+ if ((length > 0) || (png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT) != 0)
+ png_benign_error(png_ptr, "Too many IDATs found");
+
+ png_crc_finish(png_ptr, length);
+ }
+ else if (chunk_name == png_PLTE)
+ png_handle_PLTE(png_ptr, info_ptr, length);
+
+#ifdef PNG_READ_bKGD_SUPPORTED
+ else if (chunk_name == png_bKGD)
+ png_handle_bKGD(png_ptr, info_ptr, length);
+#endif
+
+#ifdef PNG_READ_cHRM_SUPPORTED
+ else if (chunk_name == png_cHRM)
+ png_handle_cHRM(png_ptr, info_ptr, length);
+#endif
+
+#ifdef PNG_READ_gAMA_SUPPORTED
+ else if (chunk_name == png_gAMA)
+ png_handle_gAMA(png_ptr, info_ptr, length);
+#endif
+
+#ifdef PNG_READ_hIST_SUPPORTED
+ else if (chunk_name == png_hIST)
+ png_handle_hIST(png_ptr, info_ptr, length);
+#endif
+
+#ifdef PNG_READ_oFFs_SUPPORTED
+ else if (chunk_name == png_oFFs)
+ png_handle_oFFs(png_ptr, info_ptr, length);
+#endif
+
+#ifdef PNG_READ_pCAL_SUPPORTED
+ else if (chunk_name == png_pCAL)
+ png_handle_pCAL(png_ptr, info_ptr, length);
+#endif
+
+#ifdef PNG_READ_sCAL_SUPPORTED
+ else if (chunk_name == png_sCAL)
+ png_handle_sCAL(png_ptr, info_ptr, length);
+#endif
+
+#ifdef PNG_READ_pHYs_SUPPORTED
+ else if (chunk_name == png_pHYs)
+ png_handle_pHYs(png_ptr, info_ptr, length);
+#endif
+
+#ifdef PNG_READ_sBIT_SUPPORTED
+ else if (chunk_name == png_sBIT)
+ png_handle_sBIT(png_ptr, info_ptr, length);
+#endif
+
+#ifdef PNG_READ_sRGB_SUPPORTED
+ else if (chunk_name == png_sRGB)
+ png_handle_sRGB(png_ptr, info_ptr, length);
+#endif
+
+#ifdef PNG_READ_iCCP_SUPPORTED
+ else if (chunk_name == png_iCCP)
+ png_handle_iCCP(png_ptr, info_ptr, length);
+#endif
+
+#ifdef PNG_READ_sPLT_SUPPORTED
+ else if (chunk_name == png_sPLT)
+ png_handle_sPLT(png_ptr, info_ptr, length);
+#endif
+
+#ifdef PNG_READ_tEXt_SUPPORTED
+ else if (chunk_name == png_tEXt)
+ png_handle_tEXt(png_ptr, info_ptr, length);
+#endif
+
+#ifdef PNG_READ_tIME_SUPPORTED
+ else if (chunk_name == png_tIME)
+ png_handle_tIME(png_ptr, info_ptr, length);
+#endif
+
+#ifdef PNG_READ_tRNS_SUPPORTED
+ else if (chunk_name == png_tRNS)
+ png_handle_tRNS(png_ptr, info_ptr, length);
+#endif
+
+#ifdef PNG_READ_zTXt_SUPPORTED
+ else if (chunk_name == png_zTXt)
+ png_handle_zTXt(png_ptr, info_ptr, length);
+#endif
+
+#ifdef PNG_READ_iTXt_SUPPORTED
+ else if (chunk_name == png_iTXt)
+ png_handle_iTXt(png_ptr, info_ptr, length);
+#endif
+
+ else
+ png_handle_unknown(png_ptr, info_ptr, length,
+ PNG_HANDLE_CHUNK_AS_DEFAULT);
+ } while ((png_ptr->mode & PNG_HAVE_IEND) == 0);
+}
+#endif /* SEQUENTIAL_READ */
+
+/* Free all memory used in the read struct */
+static void
+png_read_destroy(png_structrp png_ptr)
+{
+ png_debug(1, "in png_read_destroy");
+
+#ifdef PNG_READ_GAMMA_SUPPORTED
+ png_destroy_gamma_table(png_ptr);
+#endif
+
+ png_free(png_ptr, png_ptr->big_row_buf);
+ png_ptr->big_row_buf = NULL;
+ png_free(png_ptr, png_ptr->big_prev_row);
+ png_ptr->big_prev_row = NULL;
+ png_free(png_ptr, png_ptr->read_buffer);
+ png_ptr->read_buffer = NULL;
+
+#ifdef PNG_READ_QUANTIZE_SUPPORTED
+ png_free(png_ptr, png_ptr->palette_lookup);
+ png_ptr->palette_lookup = NULL;
+ png_free(png_ptr, png_ptr->quantize_index);
+ png_ptr->quantize_index = NULL;
+#endif
+
+ if ((png_ptr->free_me & PNG_FREE_PLTE) != 0)
+ {
+ png_zfree(png_ptr, png_ptr->palette);
+ png_ptr->palette = NULL;
+ }
+ png_ptr->free_me &= ~PNG_FREE_PLTE;
+
+#if defined(PNG_tRNS_SUPPORTED) || \
+ defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
+ if ((png_ptr->free_me & PNG_FREE_TRNS) != 0)
+ {
+ png_free(png_ptr, png_ptr->trans_alpha);
+ png_ptr->trans_alpha = NULL;
+ }
+ png_ptr->free_me &= ~PNG_FREE_TRNS;
+#endif
+
+ inflateEnd(&png_ptr->zstream);
+
+#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
+ png_free(png_ptr, png_ptr->save_buffer);
+ png_ptr->save_buffer = NULL;
+#endif
+
+#if defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED) && \
+ defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED)
+ png_free(png_ptr, png_ptr->unknown_chunk.data);
+ png_ptr->unknown_chunk.data = NULL;
+#endif
+
+#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
+ png_free(png_ptr, png_ptr->chunk_list);
+ png_ptr->chunk_list = NULL;
+#endif
+
+ /* NOTE: the 'setjmp' buffer may still be allocated and the memory and error
+ * callbacks are still set at this point. They are required to complete the
+ * destruction of the png_struct itself.
+ */
+}
+
+/* Free all memory used by the read */
+void PNGAPI
+png_destroy_read_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr,
+ png_infopp end_info_ptr_ptr)
+{
+ png_structrp png_ptr = NULL;
+
+ png_debug(1, "in png_destroy_read_struct");
+
+ if (png_ptr_ptr != NULL)
+ png_ptr = *png_ptr_ptr;
+
+ if (png_ptr == NULL)
+ return;
+
+ /* libpng 1.6.0: use the API to destroy info structs to ensure consistent
+ * behavior. Prior to 1.6.0 libpng did extra 'info' destruction in this API.
+ * The extra was, apparently, unnecessary yet this hides memory leak bugs.
+ */
+ png_destroy_info_struct(png_ptr, end_info_ptr_ptr);
+ png_destroy_info_struct(png_ptr, info_ptr_ptr);
+
+ *png_ptr_ptr = NULL;
+ png_read_destroy(png_ptr);
+ png_destroy_png_struct(png_ptr);
+}
+
+void PNGAPI
+png_set_read_status_fn(png_structrp png_ptr, png_read_status_ptr read_row_fn)
+{
+ if (png_ptr == NULL)
+ return;
+
+ png_ptr->read_row_fn = read_row_fn;
+}
+
+
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+#ifdef PNG_INFO_IMAGE_SUPPORTED
+void PNGAPI
+png_read_png(png_structrp png_ptr, png_inforp info_ptr,
+ int transforms,
+ voidp params)
+{
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+ /* png_read_info() gives us all of the information from the
+ * PNG file before the first IDAT (image data chunk).
+ */
+ png_read_info(png_ptr, info_ptr);
+ if (info_ptr->height > PNG_UINT_32_MAX/(sizeof (png_bytep)))
+ png_error(png_ptr, "Image is too high to process with png_read_png()");
+
+ /* -------------- image transformations start here ------------------- */
+ /* libpng 1.6.10: add code to cause a png_app_error if a selected TRANSFORM
+ * is not implemented. This will only happen in de-configured (non-default)
+ * libpng builds. The results can be unexpected - png_read_png may return
+ * short or mal-formed rows because the transform is skipped.
+ */
+
+ /* Tell libpng to strip 16-bit/color files down to 8 bits per color.
+ */
+ if ((transforms & PNG_TRANSFORM_SCALE_16) != 0)
+ /* Added at libpng-1.5.4. "strip_16" produces the same result that it
+ * did in earlier versions, while "scale_16" is now more accurate.
+ */
+#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
+ png_set_scale_16(png_ptr);
+#else
+ png_app_error(png_ptr, "PNG_TRANSFORM_SCALE_16 not supported");
+#endif
+
+ /* If both SCALE and STRIP are required pngrtran will effectively cancel the
+ * latter by doing SCALE first. This is ok and allows apps not to check for
+ * which is supported to get the right answer.
+ */
+ if ((transforms & PNG_TRANSFORM_STRIP_16) != 0)
+#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
+ png_set_strip_16(png_ptr);
+#else
+ png_app_error(png_ptr, "PNG_TRANSFORM_STRIP_16 not supported");
+#endif
+
+ /* Strip alpha bytes from the input data without combining with
+ * the background (not recommended).
+ */
+ if ((transforms & PNG_TRANSFORM_STRIP_ALPHA) != 0)
+#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
+ png_set_strip_alpha(png_ptr);
+#else
+ png_app_error(png_ptr, "PNG_TRANSFORM_STRIP_ALPHA not supported");
+#endif
+
+ /* Extract multiple pixels with bit depths of 1, 2, or 4 from a single
+ * byte into separate bytes (useful for paletted and grayscale images).
+ */
+ if ((transforms & PNG_TRANSFORM_PACKING) != 0)
+#ifdef PNG_READ_PACK_SUPPORTED
+ png_set_packing(png_ptr);
+#else
+ png_app_error(png_ptr, "PNG_TRANSFORM_PACKING not supported");
+#endif
+
+ /* Change the order of packed pixels to least significant bit first
+ * (not useful if you are using png_set_packing).
+ */
+ if ((transforms & PNG_TRANSFORM_PACKSWAP) != 0)
+#ifdef PNG_READ_PACKSWAP_SUPPORTED
+ png_set_packswap(png_ptr);
+#else
+ png_app_error(png_ptr, "PNG_TRANSFORM_PACKSWAP not supported");
+#endif
+
+ /* Expand paletted colors into true RGB triplets
+ * Expand grayscale images to full 8 bits from 1, 2, or 4 bits/pixel
+ * Expand paletted or RGB images with transparency to full alpha
+ * channels so the data will be available as RGBA quartets.
+ */
+ if ((transforms & PNG_TRANSFORM_EXPAND) != 0)
+#ifdef PNG_READ_EXPAND_SUPPORTED
+ png_set_expand(png_ptr);
+#else
+ png_app_error(png_ptr, "PNG_TRANSFORM_EXPAND not supported");
+#endif
+
+ /* We don't handle background color or gamma transformation or quantizing.
+ */
+
+ /* Invert monochrome files to have 0 as white and 1 as black
+ */
+ if ((transforms & PNG_TRANSFORM_INVERT_MONO) != 0)
+#ifdef PNG_READ_INVERT_SUPPORTED
+ png_set_invert_mono(png_ptr);
+#else
+ png_app_error(png_ptr, "PNG_TRANSFORM_INVERT_MONO not supported");
+#endif
+
+ /* If you want to shift the pixel values from the range [0,255] or
+ * [0,65535] to the original [0,7] or [0,31], or whatever range the
+ * colors were originally in:
+ */
+ if ((transforms & PNG_TRANSFORM_SHIFT) != 0)
+#ifdef PNG_READ_SHIFT_SUPPORTED
+ if ((info_ptr->valid & PNG_INFO_sBIT) != 0)
+ png_set_shift(png_ptr, &info_ptr->sig_bit);
+#else
+ png_app_error(png_ptr, "PNG_TRANSFORM_SHIFT not supported");
+#endif
+
+ /* Flip the RGB pixels to BGR (or RGBA to BGRA) */
+ if ((transforms & PNG_TRANSFORM_BGR) != 0)
+#ifdef PNG_READ_BGR_SUPPORTED
+ png_set_bgr(png_ptr);
+#else
+ png_app_error(png_ptr, "PNG_TRANSFORM_BGR not supported");
+#endif
+
+ /* Swap the RGBA or GA data to ARGB or AG (or BGRA to ABGR) */
+ if ((transforms & PNG_TRANSFORM_SWAP_ALPHA) != 0)
+#ifdef PNG_READ_SWAP_ALPHA_SUPPORTED
+ png_set_swap_alpha(png_ptr);
+#else
+ png_app_error(png_ptr, "PNG_TRANSFORM_SWAP_ALPHA not supported");
+#endif
+
+ /* Swap bytes of 16-bit files to least significant byte first */
+ if ((transforms & PNG_TRANSFORM_SWAP_ENDIAN) != 0)
+#ifdef PNG_READ_SWAP_SUPPORTED
+ png_set_swap(png_ptr);
+#else
+ png_app_error(png_ptr, "PNG_TRANSFORM_SWAP_ENDIAN not supported");
+#endif
+
+/* Added at libpng-1.2.41 */
+ /* Invert the alpha channel from opacity to transparency */
+ if ((transforms & PNG_TRANSFORM_INVERT_ALPHA) != 0)
+#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED
+ png_set_invert_alpha(png_ptr);
+#else
+ png_app_error(png_ptr, "PNG_TRANSFORM_INVERT_ALPHA not supported");
+#endif
+
+/* Added at libpng-1.2.41 */
+ /* Expand grayscale image to RGB */
+ if ((transforms & PNG_TRANSFORM_GRAY_TO_RGB) != 0)
+#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
+ png_set_gray_to_rgb(png_ptr);
+#else
+ png_app_error(png_ptr, "PNG_TRANSFORM_GRAY_TO_RGB not supported");
+#endif
+
+/* Added at libpng-1.5.4 */
+ if ((transforms & PNG_TRANSFORM_EXPAND_16) != 0)
+#ifdef PNG_READ_EXPAND_16_SUPPORTED
+ png_set_expand_16(png_ptr);
+#else
+ png_app_error(png_ptr, "PNG_TRANSFORM_EXPAND_16 not supported");
+#endif
+
+ /* We don't handle adding filler bytes */
+
+ /* We use png_read_image and rely on that for interlace handling, but we also
+ * call png_read_update_info therefore must turn on interlace handling now:
+ */
+ (void)png_set_interlace_handling(png_ptr);
+
+ /* Optional call to gamma correct and add the background to the palette
+ * and update info structure. REQUIRED if you are expecting libpng to
+ * update the palette for you (i.e., you selected such a transform above).
+ */
+ png_read_update_info(png_ptr, info_ptr);
+
+ /* -------------- image transformations end here ------------------- */
+
+ png_free_data(png_ptr, info_ptr, PNG_FREE_ROWS, 0);
+ if (info_ptr->row_pointers == NULL)
+ {
+ png_uint_32 iptr;
+
+ info_ptr->row_pointers = png_voidcast(png_bytepp, png_malloc(png_ptr,
+ info_ptr->height * (sizeof (png_bytep))));
+
+ for (iptr=0; iptr<info_ptr->height; iptr++)
+ info_ptr->row_pointers[iptr] = NULL;
+
+ info_ptr->free_me |= PNG_FREE_ROWS;
+
+ for (iptr = 0; iptr < info_ptr->height; iptr++)
+ info_ptr->row_pointers[iptr] = png_voidcast(png_bytep,
+ png_malloc(png_ptr, info_ptr->rowbytes));
+ }
+
+ png_read_image(png_ptr, info_ptr->row_pointers);
+ info_ptr->valid |= PNG_INFO_IDAT;
+
+ /* Read rest of file, and get additional chunks in info_ptr - REQUIRED */
+ png_read_end(png_ptr, info_ptr);
+
+ PNG_UNUSED(params)
+}
+#endif /* INFO_IMAGE */
+#endif /* SEQUENTIAL_READ */
+
+#ifdef PNG_SIMPLIFIED_READ_SUPPORTED
+/* SIMPLIFIED READ
+ *
+ * This code currently relies on the sequential reader, though it could easily
+ * be made to work with the progressive one.
+ */
+/* Arguments to png_image_finish_read: */
+
+/* Encoding of PNG data (used by the color-map code) */
+# define P_NOTSET 0 /* File encoding not yet known */
+# define P_sRGB 1 /* 8-bit encoded to sRGB gamma */
+# define P_LINEAR 2 /* 16-bit linear: not encoded, NOT pre-multiplied! */
+# define P_FILE 3 /* 8-bit encoded to file gamma, not sRGB or linear */
+# define P_LINEAR8 4 /* 8-bit linear: only from a file value */
+
+/* Color-map processing: after libpng has run on the PNG image further
+ * processing may be needed to convert the data to color-map indices.
+ */
+#define PNG_CMAP_NONE 0
+#define PNG_CMAP_GA 1 /* Process GA data to a color-map with alpha */
+#define PNG_CMAP_TRANS 2 /* Process GA data to a background index */
+#define PNG_CMAP_RGB 3 /* Process RGB data */
+#define PNG_CMAP_RGB_ALPHA 4 /* Process RGBA data */
+
+/* The following document where the background is for each processing case. */
+#define PNG_CMAP_NONE_BACKGROUND 256
+#define PNG_CMAP_GA_BACKGROUND 231
+#define PNG_CMAP_TRANS_BACKGROUND 254
+#define PNG_CMAP_RGB_BACKGROUND 256
+#define PNG_CMAP_RGB_ALPHA_BACKGROUND 216
+
+typedef struct
+{
+ /* Arguments: */
+ png_imagep image;
+ png_voidp buffer;
+ png_int_32 row_stride;
+ png_voidp colormap;
+ png_const_colorp background;
+ /* Local variables: */
+ png_voidp local_row;
+ png_voidp first_row;
+ ptrdiff_t row_bytes; /* step between rows */
+ int file_encoding; /* E_ values above */
+ png_fixed_point gamma_to_linear; /* For P_FILE, reciprocal of gamma */
+ int colormap_processing; /* PNG_CMAP_ values above */
+} png_image_read_control;
+
+/* Do all the *safe* initialization - 'safe' means that png_error won't be
+ * called, so setting up the jmp_buf is not required. This means that anything
+ * called from here must *not* call png_malloc - it has to call png_malloc_warn
+ * instead so that control is returned safely back to this routine.
+ */
+static int
+png_image_read_init(png_imagep image)
+{
+ if (image->opaque == NULL)
+ {
+ png_structp png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, image,
+ png_safe_error, png_safe_warning);
+
+ /* And set the rest of the structure to NULL to ensure that the various
+ * fields are consistent.
+ */
+ memset(image, 0, (sizeof *image));
+ image->version = PNG_IMAGE_VERSION;
+
+ if (png_ptr != NULL)
+ {
+ png_infop info_ptr = png_create_info_struct(png_ptr);
+
+ if (info_ptr != NULL)
+ {
+ png_controlp control = png_voidcast(png_controlp,
+ png_malloc_warn(png_ptr, (sizeof *control)));
+
+ if (control != NULL)
+ {
+ memset(control, 0, (sizeof *control));
+
+ control->png_ptr = png_ptr;
+ control->info_ptr = info_ptr;
+ control->for_write = 0;
+
+ image->opaque = control;
+ return 1;
+ }
+
+ /* Error clean up */
+ png_destroy_info_struct(png_ptr, &info_ptr);
+ }
+
+ png_destroy_read_struct(&png_ptr, NULL, NULL);
+ }
+
+ return png_image_error(image, "png_image_read: out of memory");
+ }
+
+ return png_image_error(image, "png_image_read: opaque pointer not NULL");
+}
+
+/* Utility to find the base format of a PNG file from a png_struct. */
+static png_uint_32
+png_image_format(png_structrp png_ptr)
+{
+ png_uint_32 format = 0;
+
+ if ((png_ptr->color_type & PNG_COLOR_MASK_COLOR) != 0)
+ format |= PNG_FORMAT_FLAG_COLOR;
+
+ if ((png_ptr->color_type & PNG_COLOR_MASK_ALPHA) != 0)
+ format |= PNG_FORMAT_FLAG_ALPHA;
+
+ /* Use png_ptr here, not info_ptr, because by examination png_handle_tRNS
+ * sets the png_struct fields; that's all we are interested in here. The
+ * precise interaction with an app call to png_set_tRNS and PNG file reading
+ * is unclear.
+ */
+ else if (png_ptr->num_trans > 0)
+ format |= PNG_FORMAT_FLAG_ALPHA;
+
+ if (png_ptr->bit_depth == 16)
+ format |= PNG_FORMAT_FLAG_LINEAR;
+
+ if ((png_ptr->color_type & PNG_COLOR_MASK_PALETTE) != 0)
+ format |= PNG_FORMAT_FLAG_COLORMAP;
+
+ return format;
+}
+
+/* Is the given gamma significantly different from sRGB? The test is the same
+ * one used in pngrtran.c when deciding whether to do gamma correction. The
+ * arithmetic optimizes the division by using the fact that the inverse of the
+ * file sRGB gamma is 2.2
+ */
+static int
+png_gamma_not_sRGB(png_fixed_point g)
+{
+ if (g < PNG_FP_1)
+ {
+ /* An uninitialized gamma is assumed to be sRGB for the simplified API. */
+ if (g == 0)
+ return 0;
+
+ return png_gamma_significant((g * 11 + 2)/5 /* i.e. *2.2, rounded */);
+ }
+
+ return 1;
+}
+
+/* Do the main body of a 'png_image_begin_read' function; read the PNG file
+ * header and fill in all the information. This is executed in a safe context,
+ * unlike the init routine above.
+ */
+static int
+png_image_read_header(png_voidp argument)
+{
+ png_imagep image = png_voidcast(png_imagep, argument);
+ png_structrp png_ptr = image->opaque->png_ptr;
+ png_inforp info_ptr = image->opaque->info_ptr;
+
+ png_set_benign_errors(png_ptr, 1/*warn*/);
+ png_read_info(png_ptr, info_ptr);
+
+ /* Do this the fast way; just read directly out of png_struct. */
+ image->width = png_ptr->width;
+ image->height = png_ptr->height;
+
+ {
+ png_uint_32 format = png_image_format(png_ptr);
+
+ image->format = format;
+
+#ifdef PNG_COLORSPACE_SUPPORTED
+ /* Does the colorspace match sRGB? If there is no color endpoint
+ * (colorant) information assume yes, otherwise require the
+ * 'ENDPOINTS_MATCHP_sRGB' colorspace flag to have been set. If the
+ * colorspace has been determined to be invalid ignore it.
+ */
+ if ((format & PNG_FORMAT_FLAG_COLOR) != 0 && ((png_ptr->colorspace.flags
+ & (PNG_COLORSPACE_HAVE_ENDPOINTS|PNG_COLORSPACE_ENDPOINTS_MATCH_sRGB|
+ PNG_COLORSPACE_INVALID)) == PNG_COLORSPACE_HAVE_ENDPOINTS))
+ image->flags |= PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB;
+#endif
+ }
+
+ /* We need the maximum number of entries regardless of the format the
+ * application sets here.
+ */
+ {
+ png_uint_32 cmap_entries;
+
+ switch (png_ptr->color_type)
+ {
+ case PNG_COLOR_TYPE_GRAY:
+ cmap_entries = 1U << png_ptr->bit_depth;
+ break;
+
+ case PNG_COLOR_TYPE_PALETTE:
+ cmap_entries = png_ptr->num_palette;
+ break;
+
+ default:
+ cmap_entries = 256;
+ break;
+ }
+
+ if (cmap_entries > 256)
+ cmap_entries = 256;
+
+ image->colormap_entries = cmap_entries;
+ }
+
+ return 1;
+}
+
+#ifdef PNG_STDIO_SUPPORTED
+int PNGAPI
+png_image_begin_read_from_stdio(png_imagep image, FILE* file)
+{
+ if (image != NULL && image->version == PNG_IMAGE_VERSION)
+ {
+ if (file != NULL)
+ {
+ if (png_image_read_init(image) != 0)
+ {
+ /* This is slightly evil, but png_init_io doesn't do anything other
+ * than this and we haven't changed the standard IO functions so
+ * this saves a 'safe' function.
+ */
+ image->opaque->png_ptr->io_ptr = file;
+ return png_safe_execute(image, png_image_read_header, image);
+ }
+ }
+
+ else
+ return png_image_error(image,
+ "png_image_begin_read_from_stdio: invalid argument");
+ }
+
+ else if (image != NULL)
+ return png_image_error(image,
+ "png_image_begin_read_from_stdio: incorrect PNG_IMAGE_VERSION");
+
+ return 0;
+}
+
+int PNGAPI
+png_image_begin_read_from_file(png_imagep image, const char *file_name)
+{
+ if (image != NULL && image->version == PNG_IMAGE_VERSION)
+ {
+ if (file_name != NULL)
+ {
+ FILE *fp = fopen(file_name, "rb");
+
+ if (fp != NULL)
+ {
+ if (png_image_read_init(image) != 0)
+ {
+ image->opaque->png_ptr->io_ptr = fp;
+ image->opaque->owned_file = 1;
+ return png_safe_execute(image, png_image_read_header, image);
+ }
+
+ /* Clean up: just the opened file. */
+ (void)fclose(fp);
+ }
+
+ else
+ return png_image_error(image, strerror(errno));
+ }
+
+ else
+ return png_image_error(image,
+ "png_image_begin_read_from_file: invalid argument");
+ }
+
+ else if (image != NULL)
+ return png_image_error(image,
+ "png_image_begin_read_from_file: incorrect PNG_IMAGE_VERSION");
+
+ return 0;
+}
+#endif /* STDIO */
+
+static void PNGCBAPI
+png_image_memory_read(png_structp png_ptr, png_bytep out, png_size_t need)
+{
+ if (png_ptr != NULL)
+ {
+ png_imagep image = png_voidcast(png_imagep, png_ptr->io_ptr);
+ if (image != NULL)
+ {
+ png_controlp cp = image->opaque;
+ if (cp != NULL)
+ {
+ png_const_bytep memory = cp->memory;
+ png_size_t size = cp->size;
+
+ if (memory != NULL && size >= need)
+ {
+ memcpy(out, memory, need);
+ cp->memory = memory + need;
+ cp->size = size - need;
+ return;
+ }
+
+ png_error(png_ptr, "read beyond end of data");
+ }
+ }
+
+ png_error(png_ptr, "invalid memory read");
+ }
+}
+
+int PNGAPI png_image_begin_read_from_memory(png_imagep image,
+ png_const_voidp memory, png_size_t size)
+{
+ if (image != NULL && image->version == PNG_IMAGE_VERSION)
+ {
+ if (memory != NULL && size > 0)
+ {
+ if (png_image_read_init(image) != 0)
+ {
+ /* Now set the IO functions to read from the memory buffer and
+ * store it into io_ptr. Again do this in-place to avoid calling a
+ * libpng function that requires error handling.
+ */
+ image->opaque->memory = png_voidcast(png_const_bytep, memory);
+ image->opaque->size = size;
+ image->opaque->png_ptr->io_ptr = image;
+ image->opaque->png_ptr->read_data_fn = png_image_memory_read;
+
+ return png_safe_execute(image, png_image_read_header, image);
+ }
+ }
+
+ else
+ return png_image_error(image,
+ "png_image_begin_read_from_memory: invalid argument");
+ }
+
+ else if (image != NULL)
+ return png_image_error(image,
+ "png_image_begin_read_from_memory: incorrect PNG_IMAGE_VERSION");
+
+ return 0;
+}
+
+/* Utility function to skip chunks that are not used by the simplified image
+ * read functions and an appropriate macro to call it.
+ */
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+static void
+png_image_skip_unused_chunks(png_structrp png_ptr)
+{
+ /* Prepare the reader to ignore all recognized chunks whose data will not
+ * be used, i.e., all chunks recognized by libpng except for those
+ * involved in basic image reading:
+ *
+ * IHDR, PLTE, IDAT, IEND
+ *
+ * Or image data handling:
+ *
+ * tRNS, bKGD, gAMA, cHRM, sRGB, [iCCP] and sBIT.
+ *
+ * This provides a small performance improvement and eliminates any
+ * potential vulnerability to security problems in the unused chunks.
+ *
+ * At present the iCCP chunk data isn't used, so iCCP chunk can be ignored
+ * too. This allows the simplified API to be compiled without iCCP support,
+ * however if the support is there the chunk is still checked to detect
+ * errors (which are unfortunately quite common.)
+ */
+ {
+ static PNG_CONST png_byte chunks_to_process[] = {
+ 98, 75, 71, 68, '\0', /* bKGD */
+ 99, 72, 82, 77, '\0', /* cHRM */
+ 103, 65, 77, 65, '\0', /* gAMA */
+# ifdef PNG_READ_iCCP_SUPPORTED
+ 105, 67, 67, 80, '\0', /* iCCP */
+# endif
+ 115, 66, 73, 84, '\0', /* sBIT */
+ 115, 82, 71, 66, '\0', /* sRGB */
+ };
+
+ /* Ignore unknown chunks and all other chunks except for the
+ * IHDR, PLTE, tRNS, IDAT, and IEND chunks.
+ */
+ png_set_keep_unknown_chunks(png_ptr, PNG_HANDLE_CHUNK_NEVER,
+ NULL, -1);
+
+ /* But do not ignore image data handling chunks */
+ png_set_keep_unknown_chunks(png_ptr, PNG_HANDLE_CHUNK_AS_DEFAULT,
+ chunks_to_process, (int)/*SAFE*/(sizeof chunks_to_process)/5);
+ }
+}
+
+# define PNG_SKIP_CHUNKS(p) png_image_skip_unused_chunks(p)
+#else
+# define PNG_SKIP_CHUNKS(p) ((void)0)
+#endif /* HANDLE_AS_UNKNOWN */
+
+/* The following macro gives the exact rounded answer for all values in the
+ * range 0..255 (it actually divides by 51.2, but the rounding still generates
+ * the correct numbers 0..5
+ */
+#define PNG_DIV51(v8) (((v8) * 5 + 130) >> 8)
+
+/* Utility functions to make particular color-maps */
+static void
+set_file_encoding(png_image_read_control *display)
+{
+ png_fixed_point g = display->image->opaque->png_ptr->colorspace.gamma;
+ if (png_gamma_significant(g) != 0)
+ {
+ if (png_gamma_not_sRGB(g) != 0)
+ {
+ display->file_encoding = P_FILE;
+ display->gamma_to_linear = png_reciprocal(g);
+ }
+
+ else
+ display->file_encoding = P_sRGB;
+ }
+
+ else
+ display->file_encoding = P_LINEAR8;
+}
+
+static unsigned int
+decode_gamma(png_image_read_control *display, png_uint_32 value, int encoding)
+{
+ if (encoding == P_FILE) /* double check */
+ encoding = display->file_encoding;
+
+ if (encoding == P_NOTSET) /* must be the file encoding */
+ {
+ set_file_encoding(display);
+ encoding = display->file_encoding;
+ }
+
+ switch (encoding)
+ {
+ case P_FILE:
+ value = png_gamma_16bit_correct(value*257, display->gamma_to_linear);
+ break;
+
+ case P_sRGB:
+ value = png_sRGB_table[value];
+ break;
+
+ case P_LINEAR:
+ break;
+
+ case P_LINEAR8:
+ value *= 257;
+ break;
+
+#ifdef __GNUC__
+ default:
+ png_error(display->image->opaque->png_ptr,
+ "unexpected encoding (internal error)");
+#endif
+ }
+
+ return value;
+}
+
+static png_uint_32
+png_colormap_compose(png_image_read_control *display,
+ png_uint_32 foreground, int foreground_encoding, png_uint_32 alpha,
+ png_uint_32 background, int encoding)
+{
+ /* The file value is composed on the background, the background has the given
+ * encoding and so does the result, the file is encoded with P_FILE and the
+ * file and alpha are 8-bit values. The (output) encoding will always be
+ * P_LINEAR or P_sRGB.
+ */
+ png_uint_32 f = decode_gamma(display, foreground, foreground_encoding);
+ png_uint_32 b = decode_gamma(display, background, encoding);
+
+ /* The alpha is always an 8-bit value (it comes from the palette), the value
+ * scaled by 255 is what PNG_sRGB_FROM_LINEAR requires.
+ */
+ f = f * alpha + b * (255-alpha);
+
+ if (encoding == P_LINEAR)
+ {
+ /* Scale to 65535; divide by 255, approximately (in fact this is extremely
+ * accurate, it divides by 255.00000005937181414556, with no overflow.)
+ */
+ f *= 257; /* Now scaled by 65535 */
+ f += f >> 16;
+ f = (f+32768) >> 16;
+ }
+
+ else /* P_sRGB */
+ f = PNG_sRGB_FROM_LINEAR(f);
+
+ return f;
+}
+
+/* NOTE: P_LINEAR values to this routine must be 16-bit, but P_FILE values must
+ * be 8-bit.
+ */
+static void
+png_create_colormap_entry(png_image_read_control *display,
+ png_uint_32 ip, png_uint_32 red, png_uint_32 green, png_uint_32 blue,
+ png_uint_32 alpha, int encoding)
+{
+ png_imagep image = display->image;
+ const int output_encoding = (image->format & PNG_FORMAT_FLAG_LINEAR) != 0 ?
+ P_LINEAR : P_sRGB;
+ const int convert_to_Y = (image->format & PNG_FORMAT_FLAG_COLOR) == 0 &&
+ (red != green || green != blue);
+
+ if (ip > 255)
+ png_error(image->opaque->png_ptr, "color-map index out of range");
+
+ /* Update the cache with whether the file gamma is significantly different
+ * from sRGB.
+ */
+ if (encoding == P_FILE)
+ {
+ if (display->file_encoding == P_NOTSET)
+ set_file_encoding(display);
+
+ /* Note that the cached value may be P_FILE too, but if it is then the
+ * gamma_to_linear member has been set.
+ */
+ encoding = display->file_encoding;
+ }
+
+ if (encoding == P_FILE)
+ {
+ png_fixed_point g = display->gamma_to_linear;
+
+ red = png_gamma_16bit_correct(red*257, g);
+ green = png_gamma_16bit_correct(green*257, g);
+ blue = png_gamma_16bit_correct(blue*257, g);
+
+ if (convert_to_Y != 0 || output_encoding == P_LINEAR)
+ {
+ alpha *= 257;
+ encoding = P_LINEAR;
+ }
+
+ else
+ {
+ red = PNG_sRGB_FROM_LINEAR(red * 255);
+ green = PNG_sRGB_FROM_LINEAR(green * 255);
+ blue = PNG_sRGB_FROM_LINEAR(blue * 255);
+ encoding = P_sRGB;
+ }
+ }
+
+ else if (encoding == P_LINEAR8)
+ {
+ /* This encoding occurs quite frequently in test cases because PngSuite
+ * includes a gAMA 1.0 chunk with most images.
+ */
+ red *= 257;
+ green *= 257;
+ blue *= 257;
+ alpha *= 257;
+ encoding = P_LINEAR;
+ }
+
+ else if (encoding == P_sRGB &&
+ (convert_to_Y != 0 || output_encoding == P_LINEAR))
+ {
+ /* The values are 8-bit sRGB values, but must be converted to 16-bit
+ * linear.
+ */
+ red = png_sRGB_table[red];
+ green = png_sRGB_table[green];
+ blue = png_sRGB_table[blue];
+ alpha *= 257;
+ encoding = P_LINEAR;
+ }
+
+ /* This is set if the color isn't gray but the output is. */
+ if (encoding == P_LINEAR)
+ {
+ if (convert_to_Y != 0)
+ {
+ /* NOTE: these values are copied from png_do_rgb_to_gray */
+ png_uint_32 y = (png_uint_32)6968 * red + (png_uint_32)23434 * green +
+ (png_uint_32)2366 * blue;
+
+ if (output_encoding == P_LINEAR)
+ y = (y + 16384) >> 15;
+
+ else
+ {
+ /* y is scaled by 32768, we need it scaled by 255: */
+ y = (y + 128) >> 8;
+ y *= 255;
+ y = PNG_sRGB_FROM_LINEAR((y + 64) >> 7);
+ alpha = PNG_DIV257(alpha);
+ encoding = P_sRGB;
+ }
+
+ blue = red = green = y;
+ }
+
+ else if (output_encoding == P_sRGB)
+ {
+ red = PNG_sRGB_FROM_LINEAR(red * 255);
+ green = PNG_sRGB_FROM_LINEAR(green * 255);
+ blue = PNG_sRGB_FROM_LINEAR(blue * 255);
+ alpha = PNG_DIV257(alpha);
+ encoding = P_sRGB;
+ }
+ }
+
+ if (encoding != output_encoding)
+ png_error(image->opaque->png_ptr, "bad encoding (internal error)");
+
+ /* Store the value. */
+ {
+# ifdef PNG_FORMAT_AFIRST_SUPPORTED
+ const int afirst = (image->format & PNG_FORMAT_FLAG_AFIRST) != 0 &&
+ (image->format & PNG_FORMAT_FLAG_ALPHA) != 0;
+# else
+# define afirst 0
+# endif
+# ifdef PNG_FORMAT_BGR_SUPPORTED
+ const int bgr = (image->format & PNG_FORMAT_FLAG_BGR) != 0 ? 2 : 0;
+# else
+# define bgr 0
+# endif
+
+ if (output_encoding == P_LINEAR)
+ {
+ png_uint_16p entry = png_voidcast(png_uint_16p, display->colormap);
+
+ entry += ip * PNG_IMAGE_SAMPLE_CHANNELS(image->format);
+
+ /* The linear 16-bit values must be pre-multiplied by the alpha channel
+ * value, if less than 65535 (this is, effectively, composite on black
+ * if the alpha channel is removed.)
+ */
+ switch (PNG_IMAGE_SAMPLE_CHANNELS(image->format))
+ {
+ case 4:
+ entry[afirst ? 0 : 3] = (png_uint_16)alpha;
+ /* FALL THROUGH */
+
+ case 3:
+ if (alpha < 65535)
+ {
+ if (alpha > 0)
+ {
+ blue = (blue * alpha + 32767U)/65535U;
+ green = (green * alpha + 32767U)/65535U;
+ red = (red * alpha + 32767U)/65535U;
+ }
+
+ else
+ red = green = blue = 0;
+ }
+ entry[afirst + (2 ^ bgr)] = (png_uint_16)blue;
+ entry[afirst + 1] = (png_uint_16)green;
+ entry[afirst + bgr] = (png_uint_16)red;
+ break;
+
+ case 2:
+ entry[1 ^ afirst] = (png_uint_16)alpha;
+ /* FALL THROUGH */
+
+ case 1:
+ if (alpha < 65535)
+ {
+ if (alpha > 0)
+ green = (green * alpha + 32767U)/65535U;
+
+ else
+ green = 0;
+ }
+ entry[afirst] = (png_uint_16)green;
+ break;
+
+ default:
+ break;
+ }
+ }
+
+ else /* output encoding is P_sRGB */
+ {
+ png_bytep entry = png_voidcast(png_bytep, display->colormap);
+
+ entry += ip * PNG_IMAGE_SAMPLE_CHANNELS(image->format);
+
+ switch (PNG_IMAGE_SAMPLE_CHANNELS(image->format))
+ {
+ case 4:
+ entry[afirst ? 0 : 3] = (png_byte)alpha;
+ case 3:
+ entry[afirst + (2 ^ bgr)] = (png_byte)blue;
+ entry[afirst + 1] = (png_byte)green;
+ entry[afirst + bgr] = (png_byte)red;
+ break;
+
+ case 2:
+ entry[1 ^ afirst] = (png_byte)alpha;
+ case 1:
+ entry[afirst] = (png_byte)green;
+ break;
+
+ default:
+ break;
+ }
+ }
+
+# ifdef afirst
+# undef afirst
+# endif
+# ifdef bgr
+# undef bgr
+# endif
+ }
+}
+
+static int
+make_gray_file_colormap(png_image_read_control *display)
+{
+ unsigned int i;
+
+ for (i=0; i<256; ++i)
+ png_create_colormap_entry(display, i, i, i, i, 255, P_FILE);
+
+ return i;
+}
+
+static int
+make_gray_colormap(png_image_read_control *display)
+{
+ unsigned int i;
+
+ for (i=0; i<256; ++i)
+ png_create_colormap_entry(display, i, i, i, i, 255, P_sRGB);
+
+ return i;
+}
+#define PNG_GRAY_COLORMAP_ENTRIES 256
+
+static int
+make_ga_colormap(png_image_read_control *display)
+{
+ unsigned int i, a;
+
+ /* Alpha is retained, the output will be a color-map with entries
+ * selected by six levels of alpha. One transparent entry, 6 gray
+ * levels for all the intermediate alpha values, leaving 230 entries
+ * for the opaque grays. The color-map entries are the six values
+ * [0..5]*51, the GA processing uses PNG_DIV51(value) to find the
+ * relevant entry.
+ *
+ * if (alpha > 229) // opaque
+ * {
+ * // The 231 entries are selected to make the math below work:
+ * base = 0;
+ * entry = (231 * gray + 128) >> 8;
+ * }
+ * else if (alpha < 26) // transparent
+ * {
+ * base = 231;
+ * entry = 0;
+ * }
+ * else // partially opaque
+ * {
+ * base = 226 + 6 * PNG_DIV51(alpha);
+ * entry = PNG_DIV51(gray);
+ * }
+ */
+ i = 0;
+ while (i < 231)
+ {
+ unsigned int gray = (i * 256 + 115) / 231;
+ png_create_colormap_entry(display, i++, gray, gray, gray, 255, P_sRGB);
+ }
+
+ /* 255 is used here for the component values for consistency with the code
+ * that undoes premultiplication in pngwrite.c.
+ */
+ png_create_colormap_entry(display, i++, 255, 255, 255, 0, P_sRGB);
+
+ for (a=1; a<5; ++a)
+ {
+ unsigned int g;
+
+ for (g=0; g<6; ++g)
+ png_create_colormap_entry(display, i++, g*51, g*51, g*51, a*51,
+ P_sRGB);
+ }
+
+ return i;
+}
+
+#define PNG_GA_COLORMAP_ENTRIES 256
+
+static int
+make_rgb_colormap(png_image_read_control *display)
+{
+ unsigned int i, r;
+
+ /* Build a 6x6x6 opaque RGB cube */
+ for (i=r=0; r<6; ++r)
+ {
+ unsigned int g;
+
+ for (g=0; g<6; ++g)
+ {
+ unsigned int b;
+
+ for (b=0; b<6; ++b)
+ png_create_colormap_entry(display, i++, r*51, g*51, b*51, 255,
+ P_sRGB);
+ }
+ }
+
+ return i;
+}
+
+#define PNG_RGB_COLORMAP_ENTRIES 216
+
+/* Return a palette index to the above palette given three 8-bit sRGB values. */
+#define PNG_RGB_INDEX(r,g,b) \
+ ((png_byte)(6 * (6 * PNG_DIV51(r) + PNG_DIV51(g)) + PNG_DIV51(b)))
+
+static int
+png_image_read_colormap(png_voidp argument)
+{
+ png_image_read_control *display =
+ png_voidcast(png_image_read_control*, argument);
+ const png_imagep image = display->image;
+
+ const png_structrp png_ptr = image->opaque->png_ptr;
+ const png_uint_32 output_format = image->format;
+ const int output_encoding = (output_format & PNG_FORMAT_FLAG_LINEAR) != 0 ?
+ P_LINEAR : P_sRGB;
+
+ unsigned int cmap_entries;
+ unsigned int output_processing; /* Output processing option */
+ unsigned int data_encoding = P_NOTSET; /* Encoding libpng must produce */
+
+ /* Background information; the background color and the index of this color
+ * in the color-map if it exists (else 256).
+ */
+ unsigned int background_index = 256;
+ png_uint_32 back_r, back_g, back_b;
+
+ /* Flags to accumulate things that need to be done to the input. */
+ int expand_tRNS = 0;
+
+ /* Exclude the NYI feature of compositing onto a color-mapped buffer; it is
+ * very difficult to do, the results look awful, and it is difficult to see
+ * what possible use it is because the application can't control the
+ * color-map.
+ */
+ if (((png_ptr->color_type & PNG_COLOR_MASK_ALPHA) != 0 ||
+ png_ptr->num_trans > 0) /* alpha in input */ &&
+ ((output_format & PNG_FORMAT_FLAG_ALPHA) == 0) /* no alpha in output */)
+ {
+ if (output_encoding == P_LINEAR) /* compose on black */
+ back_b = back_g = back_r = 0;
+
+ else if (display->background == NULL /* no way to remove it */)
+ png_error(png_ptr,
+ "a background color must be supplied to remove alpha/transparency");
+
+ /* Get a copy of the background color (this avoids repeating the checks
+ * below.) The encoding is 8-bit sRGB or 16-bit linear, depending on the
+ * output format.
+ */
+ else
+ {
+ back_g = display->background->green;
+ if ((output_format & PNG_FORMAT_FLAG_COLOR) != 0)
+ {
+ back_r = display->background->red;
+ back_b = display->background->blue;
+ }
+ else
+ back_b = back_r = back_g;
+ }
+ }
+
+ else if (output_encoding == P_LINEAR)
+ back_b = back_r = back_g = 65535;
+
+ else
+ back_b = back_r = back_g = 255;
+
+ /* Default the input file gamma if required - this is necessary because
+ * libpng assumes that if no gamma information is present the data is in the
+ * output format, but the simplified API deduces the gamma from the input
+ * format.
+ */
+ if ((png_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_GAMMA) == 0)
+ {
+ /* Do this directly, not using the png_colorspace functions, to ensure
+ * that it happens even if the colorspace is invalid (though probably if
+ * it is the setting will be ignored) Note that the same thing can be
+ * achieved at the application interface with png_set_gAMA.
+ */
+ if (png_ptr->bit_depth == 16 &&
+ (image->flags & PNG_IMAGE_FLAG_16BIT_sRGB) == 0)
+ png_ptr->colorspace.gamma = PNG_GAMMA_LINEAR;
+
+ else
+ png_ptr->colorspace.gamma = PNG_GAMMA_sRGB_INVERSE;
+
+ png_ptr->colorspace.flags |= PNG_COLORSPACE_HAVE_GAMMA;
+ }
+
+ /* Decide what to do based on the PNG color type of the input data. The
+ * utility function png_create_colormap_entry deals with most aspects of the
+ * output transformations; this code works out how to produce bytes of
+ * color-map entries from the original format.
+ */
+ switch (png_ptr->color_type)
+ {
+ case PNG_COLOR_TYPE_GRAY:
+ if (png_ptr->bit_depth <= 8)
+ {
+ /* There at most 256 colors in the output, regardless of
+ * transparency.
+ */
+ unsigned int step, i, val, trans = 256/*ignore*/, back_alpha = 0;
+
+ cmap_entries = 1U << png_ptr->bit_depth;
+ if (cmap_entries > image->colormap_entries)
+ png_error(png_ptr, "gray[8] color-map: too few entries");
+
+ step = 255 / (cmap_entries - 1);
+ output_processing = PNG_CMAP_NONE;
+
+ /* If there is a tRNS chunk then this either selects a transparent
+ * value or, if the output has no alpha, the background color.
+ */
+ if (png_ptr->num_trans > 0)
+ {
+ trans = png_ptr->trans_color.gray;
+
+ if ((output_format & PNG_FORMAT_FLAG_ALPHA) == 0)
+ back_alpha = output_encoding == P_LINEAR ? 65535 : 255;
+ }
+
+ /* png_create_colormap_entry just takes an RGBA and writes the
+ * corresponding color-map entry using the format from 'image',
+ * including the required conversion to sRGB or linear as
+ * appropriate. The input values are always either sRGB (if the
+ * gamma correction flag is 0) or 0..255 scaled file encoded values
+ * (if the function must gamma correct them).
+ */
+ for (i=val=0; i<cmap_entries; ++i, val += step)
+ {
+ /* 'i' is a file value. While this will result in duplicated
+ * entries for 8-bit non-sRGB encoded files it is necessary to
+ * have non-gamma corrected values to do tRNS handling.
+ */
+ if (i != trans)
+ png_create_colormap_entry(display, i, val, val, val, 255,
+ P_FILE/*8-bit with file gamma*/);
+
+ /* Else this entry is transparent. The colors don't matter if
+ * there is an alpha channel (back_alpha == 0), but it does no
+ * harm to pass them in; the values are not set above so this
+ * passes in white.
+ *
+ * NOTE: this preserves the full precision of the application
+ * supplied background color when it is used.
+ */
+ else
+ png_create_colormap_entry(display, i, back_r, back_g, back_b,
+ back_alpha, output_encoding);
+ }
+
+ /* We need libpng to preserve the original encoding. */
+ data_encoding = P_FILE;
+
+ /* The rows from libpng, while technically gray values, are now also
+ * color-map indices; however, they may need to be expanded to 1
+ * byte per pixel. This is what png_set_packing does (i.e., it
+ * unpacks the bit values into bytes.)
+ */
+ if (png_ptr->bit_depth < 8)
+ png_set_packing(png_ptr);
+ }
+
+ else /* bit depth is 16 */
+ {
+ /* The 16-bit input values can be converted directly to 8-bit gamma
+ * encoded values; however, if a tRNS chunk is present 257 color-map
+ * entries are required. This means that the extra entry requires
+ * special processing; add an alpha channel, sacrifice gray level
+ * 254 and convert transparent (alpha==0) entries to that.
+ *
+ * Use libpng to chop the data to 8 bits. Convert it to sRGB at the
+ * same time to minimize quality loss. If a tRNS chunk is present
+ * this means libpng must handle it too; otherwise it is impossible
+ * to do the exact match on the 16-bit value.
+ *
+ * If the output has no alpha channel *and* the background color is
+ * gray then it is possible to let libpng handle the substitution by
+ * ensuring that the corresponding gray level matches the background
+ * color exactly.
+ */
+ data_encoding = P_sRGB;
+
+ if (PNG_GRAY_COLORMAP_ENTRIES > image->colormap_entries)
+ png_error(png_ptr, "gray[16] color-map: too few entries");
+
+ cmap_entries = make_gray_colormap(display);
+
+ if (png_ptr->num_trans > 0)
+ {
+ unsigned int back_alpha;
+
+ if ((output_format & PNG_FORMAT_FLAG_ALPHA) != 0)
+ back_alpha = 0;
+
+ else
+ {
+ if (back_r == back_g && back_g == back_b)
+ {
+ /* Background is gray; no special processing will be
+ * required.
+ */
+ png_color_16 c;
+ png_uint_32 gray = back_g;
+
+ if (output_encoding == P_LINEAR)
+ {
+ gray = PNG_sRGB_FROM_LINEAR(gray * 255);
+
+ /* And make sure the corresponding palette entry
+ * matches.
+ */
+ png_create_colormap_entry(display, gray, back_g, back_g,
+ back_g, 65535, P_LINEAR);
+ }
+
+ /* The background passed to libpng, however, must be the
+ * sRGB value.
+ */
+ c.index = 0; /*unused*/
+ c.gray = c.red = c.green = c.blue = (png_uint_16)gray;
+
+ /* NOTE: does this work without expanding tRNS to alpha?
+ * It should be the color->gray case below apparently
+ * doesn't.
+ */
+ png_set_background_fixed(png_ptr, &c,
+ PNG_BACKGROUND_GAMMA_SCREEN, 0/*need_expand*/,
+ 0/*gamma: not used*/);
+
+ output_processing = PNG_CMAP_NONE;
+ break;
+ }
+#ifdef __COVERITY__
+ /* Coverity claims that output_encoding cannot be 2 (P_LINEAR)
+ * here.
+ */
+ back_alpha = 255;
+#else
+ back_alpha = output_encoding == P_LINEAR ? 65535 : 255;
+#endif
+ }
+
+ /* output_processing means that the libpng-processed row will be
+ * 8-bit GA and it has to be processing to single byte color-map
+ * values. Entry 254 is replaced by either a completely
+ * transparent entry or by the background color at full
+ * precision (and the background color is not a simple gray
+ * level in this case.)
+ */
+ expand_tRNS = 1;
+ output_processing = PNG_CMAP_TRANS;
+ background_index = 254;
+
+ /* And set (overwrite) color-map entry 254 to the actual
+ * background color at full precision.
+ */
+ png_create_colormap_entry(display, 254, back_r, back_g, back_b,
+ back_alpha, output_encoding);
+ }
+
+ else
+ output_processing = PNG_CMAP_NONE;
+ }
+ break;
+
+ case PNG_COLOR_TYPE_GRAY_ALPHA:
+ /* 8-bit or 16-bit PNG with two channels - gray and alpha. A minimum
+ * of 65536 combinations. If, however, the alpha channel is to be
+ * removed there are only 256 possibilities if the background is gray.
+ * (Otherwise there is a subset of the 65536 possibilities defined by
+ * the triangle between black, white and the background color.)
+ *
+ * Reduce 16-bit files to 8-bit and sRGB encode the result. No need to
+ * worry about tRNS matching - tRNS is ignored if there is an alpha
+ * channel.
+ */
+ data_encoding = P_sRGB;
+
+ if ((output_format & PNG_FORMAT_FLAG_ALPHA) != 0)
+ {
+ if (PNG_GA_COLORMAP_ENTRIES > image->colormap_entries)
+ png_error(png_ptr, "gray+alpha color-map: too few entries");
+
+ cmap_entries = make_ga_colormap(display);
+
+ background_index = PNG_CMAP_GA_BACKGROUND;
+ output_processing = PNG_CMAP_GA;
+ }
+
+ else /* alpha is removed */
+ {
+ /* Alpha must be removed as the PNG data is processed when the
+ * background is a color because the G and A channels are
+ * independent and the vector addition (non-parallel vectors) is a
+ * 2-D problem.
+ *
+ * This can be reduced to the same algorithm as above by making a
+ * colormap containing gray levels (for the opaque grays), a
+ * background entry (for a transparent pixel) and a set of four six
+ * level color values, one set for each intermediate alpha value.
+ * See the comments in make_ga_colormap for how this works in the
+ * per-pixel processing.
+ *
+ * If the background is gray, however, we only need a 256 entry gray
+ * level color map. It is sufficient to make the entry generated
+ * for the background color be exactly the color specified.
+ */
+ if ((output_format & PNG_FORMAT_FLAG_COLOR) == 0 ||
+ (back_r == back_g && back_g == back_b))
+ {
+ /* Background is gray; no special processing will be required. */
+ png_color_16 c;
+ png_uint_32 gray = back_g;
+
+ if (PNG_GRAY_COLORMAP_ENTRIES > image->colormap_entries)
+ png_error(png_ptr, "gray-alpha color-map: too few entries");
+
+ cmap_entries = make_gray_colormap(display);
+
+ if (output_encoding == P_LINEAR)
+ {
+ gray = PNG_sRGB_FROM_LINEAR(gray * 255);
+
+ /* And make sure the corresponding palette entry matches. */
+ png_create_colormap_entry(display, gray, back_g, back_g,
+ back_g, 65535, P_LINEAR);
+ }
+
+ /* The background passed to libpng, however, must be the sRGB
+ * value.
+ */
+ c.index = 0; /*unused*/
+ c.gray = c.red = c.green = c.blue = (png_uint_16)gray;
+
+ png_set_background_fixed(png_ptr, &c,
+ PNG_BACKGROUND_GAMMA_SCREEN, 0/*need_expand*/,
+ 0/*gamma: not used*/);
+
+ output_processing = PNG_CMAP_NONE;
+ }
+
+ else
+ {
+ png_uint_32 i, a;
+
+ /* This is the same as png_make_ga_colormap, above, except that
+ * the entries are all opaque.
+ */
+ if (PNG_GA_COLORMAP_ENTRIES > image->colormap_entries)
+ png_error(png_ptr, "ga-alpha color-map: too few entries");
+
+ i = 0;
+ while (i < 231)
+ {
+ png_uint_32 gray = (i * 256 + 115) / 231;
+ png_create_colormap_entry(display, i++, gray, gray, gray,
+ 255, P_sRGB);
+ }
+
+ /* NOTE: this preserves the full precision of the application
+ * background color.
+ */
+ background_index = i;
+ png_create_colormap_entry(display, i++, back_r, back_g, back_b,
+#ifdef __COVERITY__
+ /* Coverity claims that output_encoding cannot be 2 (P_LINEAR)
+ * here.
+ */ 255U,
+#else
+ output_encoding == P_LINEAR ? 65535U : 255U,
+#endif
+ output_encoding);
+
+ /* For non-opaque input composite on the sRGB background - this
+ * requires inverting the encoding for each component. The input
+ * is still converted to the sRGB encoding because this is a
+ * reasonable approximate to the logarithmic curve of human
+ * visual sensitivity, at least over the narrow range which PNG
+ * represents. Consequently 'G' is always sRGB encoded, while
+ * 'A' is linear. We need the linear background colors.
+ */
+ if (output_encoding == P_sRGB) /* else already linear */
+ {
+ /* This may produce a value not exactly matching the
+ * background, but that's ok because these numbers are only
+ * used when alpha != 0
+ */
+ back_r = png_sRGB_table[back_r];
+ back_g = png_sRGB_table[back_g];
+ back_b = png_sRGB_table[back_b];
+ }
+
+ for (a=1; a<5; ++a)
+ {
+ unsigned int g;
+
+ /* PNG_sRGB_FROM_LINEAR expects a 16-bit linear value scaled
+ * by an 8-bit alpha value (0..255).
+ */
+ png_uint_32 alpha = 51 * a;
+ png_uint_32 back_rx = (255-alpha) * back_r;
+ png_uint_32 back_gx = (255-alpha) * back_g;
+ png_uint_32 back_bx = (255-alpha) * back_b;
+
+ for (g=0; g<6; ++g)
+ {
+ png_uint_32 gray = png_sRGB_table[g*51] * alpha;
+
+ png_create_colormap_entry(display, i++,
+ PNG_sRGB_FROM_LINEAR(gray + back_rx),
+ PNG_sRGB_FROM_LINEAR(gray + back_gx),
+ PNG_sRGB_FROM_LINEAR(gray + back_bx), 255, P_sRGB);
+ }
+ }
+
+ cmap_entries = i;
+ output_processing = PNG_CMAP_GA;
+ }
+ }
+ break;
+
+ case PNG_COLOR_TYPE_RGB:
+ case PNG_COLOR_TYPE_RGB_ALPHA:
+ /* Exclude the case where the output is gray; we can always handle this
+ * with the cases above.
+ */
+ if ((output_format & PNG_FORMAT_FLAG_COLOR) == 0)
+ {
+ /* The color-map will be grayscale, so we may as well convert the
+ * input RGB values to a simple grayscale and use the grayscale
+ * code above.
+ *
+ * NOTE: calling this apparently damages the recognition of the
+ * transparent color in background color handling; call
+ * png_set_tRNS_to_alpha before png_set_background_fixed.
+ */
+ png_set_rgb_to_gray_fixed(png_ptr, PNG_ERROR_ACTION_NONE, -1,
+ -1);
+ data_encoding = P_sRGB;
+
+ /* The output will now be one or two 8-bit gray or gray+alpha
+ * channels. The more complex case arises when the input has alpha.
+ */
+ if ((png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA ||
+ png_ptr->num_trans > 0) &&
+ (output_format & PNG_FORMAT_FLAG_ALPHA) != 0)
+ {
+ /* Both input and output have an alpha channel, so no background
+ * processing is required; just map the GA bytes to the right
+ * color-map entry.
+ */
+ expand_tRNS = 1;
+
+ if (PNG_GA_COLORMAP_ENTRIES > image->colormap_entries)
+ png_error(png_ptr, "rgb[ga] color-map: too few entries");
+
+ cmap_entries = make_ga_colormap(display);
+ background_index = PNG_CMAP_GA_BACKGROUND;
+ output_processing = PNG_CMAP_GA;
+ }
+
+ else
+ {
+ /* Either the input or the output has no alpha channel, so there
+ * will be no non-opaque pixels in the color-map; it will just be
+ * grayscale.
+ */
+ if (PNG_GRAY_COLORMAP_ENTRIES > image->colormap_entries)
+ png_error(png_ptr, "rgb[gray] color-map: too few entries");
+
+ /* Ideally this code would use libpng to do the gamma correction,
+ * but if an input alpha channel is to be removed we will hit the
+ * libpng bug in gamma+compose+rgb-to-gray (the double gamma
+ * correction bug). Fix this by dropping the gamma correction in
+ * this case and doing it in the palette; this will result in
+ * duplicate palette entries, but that's better than the
+ * alternative of double gamma correction.
+ */
+ if ((png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA ||
+ png_ptr->num_trans > 0) &&
+ png_gamma_not_sRGB(png_ptr->colorspace.gamma) != 0)
+ {
+ cmap_entries = make_gray_file_colormap(display);
+ data_encoding = P_FILE;
+ }
+
+ else
+ cmap_entries = make_gray_colormap(display);
+
+ /* But if the input has alpha or transparency it must be removed
+ */
+ if (png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA ||
+ png_ptr->num_trans > 0)
+ {
+ png_color_16 c;
+ png_uint_32 gray = back_g;
+
+ /* We need to ensure that the application background exists in
+ * the colormap and that completely transparent pixels map to
+ * it. Achieve this simply by ensuring that the entry
+ * selected for the background really is the background color.
+ */
+ if (data_encoding == P_FILE) /* from the fixup above */
+ {
+ /* The app supplied a gray which is in output_encoding, we
+ * need to convert it to a value of the input (P_FILE)
+ * encoding then set this palette entry to the required
+ * output encoding.
+ */
+ if (output_encoding == P_sRGB)
+ gray = png_sRGB_table[gray]; /* now P_LINEAR */
+
+ gray = PNG_DIV257(png_gamma_16bit_correct(gray,
+ png_ptr->colorspace.gamma)); /* now P_FILE */
+
+ /* And make sure the corresponding palette entry contains
+ * exactly the required sRGB value.
+ */
+ png_create_colormap_entry(display, gray, back_g, back_g,
+ back_g, 0/*unused*/, output_encoding);
+ }
+
+ else if (output_encoding == P_LINEAR)
+ {
+ gray = PNG_sRGB_FROM_LINEAR(gray * 255);
+
+ /* And make sure the corresponding palette entry matches.
+ */
+ png_create_colormap_entry(display, gray, back_g, back_g,
+ back_g, 0/*unused*/, P_LINEAR);
+ }
+
+ /* The background passed to libpng, however, must be the
+ * output (normally sRGB) value.
+ */
+ c.index = 0; /*unused*/
+ c.gray = c.red = c.green = c.blue = (png_uint_16)gray;
+
+ /* NOTE: the following is apparently a bug in libpng. Without
+ * it the transparent color recognition in
+ * png_set_background_fixed seems to go wrong.
+ */
+ expand_tRNS = 1;
+ png_set_background_fixed(png_ptr, &c,
+ PNG_BACKGROUND_GAMMA_SCREEN, 0/*need_expand*/,
+ 0/*gamma: not used*/);
+ }
+
+ output_processing = PNG_CMAP_NONE;
+ }
+ }
+
+ else /* output is color */
+ {
+ /* We could use png_quantize here so long as there is no transparent
+ * color or alpha; png_quantize ignores alpha. Easier overall just
+ * to do it once and using PNG_DIV51 on the 6x6x6 reduced RGB cube.
+ * Consequently we always want libpng to produce sRGB data.
+ */
+ data_encoding = P_sRGB;
+
+ /* Is there any transparency or alpha? */
+ if (png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA ||
+ png_ptr->num_trans > 0)
+ {
+ /* Is there alpha in the output too? If so all four channels are
+ * processed into a special RGB cube with alpha support.
+ */
+ if ((output_format & PNG_FORMAT_FLAG_ALPHA) != 0)
+ {
+ png_uint_32 r;
+
+ if (PNG_RGB_COLORMAP_ENTRIES+1+27 > image->colormap_entries)
+ png_error(png_ptr, "rgb+alpha color-map: too few entries");
+
+ cmap_entries = make_rgb_colormap(display);
+
+ /* Add a transparent entry. */
+ png_create_colormap_entry(display, cmap_entries, 255, 255,
+ 255, 0, P_sRGB);
+
+ /* This is stored as the background index for the processing
+ * algorithm.
+ */
+ background_index = cmap_entries++;
+
+ /* Add 27 r,g,b entries each with alpha 0.5. */
+ for (r=0; r<256; r = (r << 1) | 0x7f)
+ {
+ png_uint_32 g;
+
+ for (g=0; g<256; g = (g << 1) | 0x7f)
+ {
+ png_uint_32 b;
+
+ /* This generates components with the values 0, 127 and
+ * 255
+ */
+ for (b=0; b<256; b = (b << 1) | 0x7f)
+ png_create_colormap_entry(display, cmap_entries++,
+ r, g, b, 128, P_sRGB);
+ }
+ }
+
+ expand_tRNS = 1;
+ output_processing = PNG_CMAP_RGB_ALPHA;
+ }
+
+ else
+ {
+ /* Alpha/transparency must be removed. The background must
+ * exist in the color map (achieved by setting adding it after
+ * the 666 color-map). If the standard processing code will
+ * pick up this entry automatically that's all that is
+ * required; libpng can be called to do the background
+ * processing.
+ */
+ unsigned int sample_size =
+ PNG_IMAGE_SAMPLE_SIZE(output_format);
+ png_uint_32 r, g, b; /* sRGB background */
+
+ if (PNG_RGB_COLORMAP_ENTRIES+1+27 > image->colormap_entries)
+ png_error(png_ptr, "rgb-alpha color-map: too few entries");
+
+ cmap_entries = make_rgb_colormap(display);
+
+ png_create_colormap_entry(display, cmap_entries, back_r,
+ back_g, back_b, 0/*unused*/, output_encoding);
+
+ if (output_encoding == P_LINEAR)
+ {
+ r = PNG_sRGB_FROM_LINEAR(back_r * 255);
+ g = PNG_sRGB_FROM_LINEAR(back_g * 255);
+ b = PNG_sRGB_FROM_LINEAR(back_b * 255);
+ }
+
+ else
+ {
+ r = back_r;
+ g = back_g;
+ b = back_g;
+ }
+
+ /* Compare the newly-created color-map entry with the one the
+ * PNG_CMAP_RGB algorithm will use. If the two entries don't
+ * match, add the new one and set this as the background
+ * index.
+ */
+ if (memcmp((png_const_bytep)display->colormap +
+ sample_size * cmap_entries,
+ (png_const_bytep)display->colormap +
+ sample_size * PNG_RGB_INDEX(r,g,b),
+ sample_size) != 0)
+ {
+ /* The background color must be added. */
+ background_index = cmap_entries++;
+
+ /* Add 27 r,g,b entries each with created by composing with
+ * the background at alpha 0.5.
+ */
+ for (r=0; r<256; r = (r << 1) | 0x7f)
+ {
+ for (g=0; g<256; g = (g << 1) | 0x7f)
+ {
+ /* This generates components with the values 0, 127
+ * and 255
+ */
+ for (b=0; b<256; b = (b << 1) | 0x7f)
+ png_create_colormap_entry(display, cmap_entries++,
+ png_colormap_compose(display, r, P_sRGB, 128,
+ back_r, output_encoding),
+ png_colormap_compose(display, g, P_sRGB, 128,
+ back_g, output_encoding),
+ png_colormap_compose(display, b, P_sRGB, 128,
+ back_b, output_encoding),
+ 0/*unused*/, output_encoding);
+ }
+ }
+
+ expand_tRNS = 1;
+ output_processing = PNG_CMAP_RGB_ALPHA;
+ }
+
+ else /* background color is in the standard color-map */
+ {
+ png_color_16 c;
+
+ c.index = 0; /*unused*/
+ c.red = (png_uint_16)back_r;
+ c.gray = c.green = (png_uint_16)back_g;
+ c.blue = (png_uint_16)back_b;
+
+ png_set_background_fixed(png_ptr, &c,
+ PNG_BACKGROUND_GAMMA_SCREEN, 0/*need_expand*/,
+ 0/*gamma: not used*/);
+
+ output_processing = PNG_CMAP_RGB;
+ }
+ }
+ }
+
+ else /* no alpha or transparency in the input */
+ {
+ /* Alpha in the output is irrelevant, simply map the opaque input
+ * pixels to the 6x6x6 color-map.
+ */
+ if (PNG_RGB_COLORMAP_ENTRIES > image->colormap_entries)
+ png_error(png_ptr, "rgb color-map: too few entries");
+
+ cmap_entries = make_rgb_colormap(display);
+ output_processing = PNG_CMAP_RGB;
+ }
+ }
+ break;
+
+ case PNG_COLOR_TYPE_PALETTE:
+ /* It's already got a color-map. It may be necessary to eliminate the
+ * tRNS entries though.
+ */
+ {
+ unsigned int num_trans = png_ptr->num_trans;
+ png_const_bytep trans = num_trans > 0 ? png_ptr->trans_alpha : NULL;
+ png_const_colorp colormap = png_ptr->palette;
+ const int do_background = trans != NULL &&
+ (output_format & PNG_FORMAT_FLAG_ALPHA) == 0;
+ unsigned int i;
+
+ /* Just in case: */
+ if (trans == NULL)
+ num_trans = 0;
+
+ output_processing = PNG_CMAP_NONE;
+ data_encoding = P_FILE; /* Don't change from color-map indices */
+ cmap_entries = png_ptr->num_palette;
+ if (cmap_entries > 256)
+ cmap_entries = 256;
+
+ if (cmap_entries > image->colormap_entries)
+ png_error(png_ptr, "palette color-map: too few entries");
+
+ for (i=0; i < cmap_entries; ++i)
+ {
+ if (do_background != 0 && i < num_trans && trans[i] < 255)
+ {
+ if (trans[i] == 0)
+ png_create_colormap_entry(display, i, back_r, back_g,
+ back_b, 0, output_encoding);
+
+ else
+ {
+ /* Must compose the PNG file color in the color-map entry
+ * on the sRGB color in 'back'.
+ */
+ png_create_colormap_entry(display, i,
+ png_colormap_compose(display, colormap[i].red, P_FILE,
+ trans[i], back_r, output_encoding),
+ png_colormap_compose(display, colormap[i].green, P_FILE,
+ trans[i], back_g, output_encoding),
+ png_colormap_compose(display, colormap[i].blue, P_FILE,
+ trans[i], back_b, output_encoding),
+ output_encoding == P_LINEAR ? trans[i] * 257U :
+ trans[i],
+ output_encoding);
+ }
+ }
+
+ else
+ png_create_colormap_entry(display, i, colormap[i].red,
+ colormap[i].green, colormap[i].blue,
+ i < num_trans ? trans[i] : 255U, P_FILE/*8-bit*/);
+ }
+
+ /* The PNG data may have indices packed in fewer than 8 bits, it
+ * must be expanded if so.
+ */
+ if (png_ptr->bit_depth < 8)
+ png_set_packing(png_ptr);
+ }
+ break;
+
+ default:
+ png_error(png_ptr, "invalid PNG color type");
+ /*NOT REACHED*/
+ }
+
+ /* Now deal with the output processing */
+ if (expand_tRNS != 0 && png_ptr->num_trans > 0 &&
+ (png_ptr->color_type & PNG_COLOR_MASK_ALPHA) == 0)
+ png_set_tRNS_to_alpha(png_ptr);
+
+ switch (data_encoding)
+ {
+ case P_sRGB:
+ /* Change to 8-bit sRGB */
+ png_set_alpha_mode_fixed(png_ptr, PNG_ALPHA_PNG, PNG_GAMMA_sRGB);
+ /* FALL THROUGH */
+
+ case P_FILE:
+ if (png_ptr->bit_depth > 8)
+ png_set_scale_16(png_ptr);
+ break;
+
+#ifdef __GNUC__
+ default:
+ png_error(png_ptr, "bad data option (internal error)");
+#endif
+ }
+
+ if (cmap_entries > 256 || cmap_entries > image->colormap_entries)
+ png_error(png_ptr, "color map overflow (BAD internal error)");
+
+ image->colormap_entries = cmap_entries;
+
+ /* Double check using the recorded background index */
+ switch (output_processing)
+ {
+ case PNG_CMAP_NONE:
+ if (background_index != PNG_CMAP_NONE_BACKGROUND)
+ goto bad_background;
+ break;
+
+ case PNG_CMAP_GA:
+ if (background_index != PNG_CMAP_GA_BACKGROUND)
+ goto bad_background;
+ break;
+
+ case PNG_CMAP_TRANS:
+ if (background_index >= cmap_entries ||
+ background_index != PNG_CMAP_TRANS_BACKGROUND)
+ goto bad_background;
+ break;
+
+ case PNG_CMAP_RGB:
+ if (background_index != PNG_CMAP_RGB_BACKGROUND)
+ goto bad_background;
+ break;
+
+ case PNG_CMAP_RGB_ALPHA:
+ if (background_index != PNG_CMAP_RGB_ALPHA_BACKGROUND)
+ goto bad_background;
+ break;
+
+ default:
+ png_error(png_ptr, "bad processing option (internal error)");
+
+ bad_background:
+ png_error(png_ptr, "bad background index (internal error)");
+ }
+
+ display->colormap_processing = output_processing;
+
+ return 1/*ok*/;
+}
+
+/* The final part of the color-map read called from png_image_finish_read. */
+static int
+png_image_read_and_map(png_voidp argument)
+{
+ png_image_read_control *display = png_voidcast(png_image_read_control*,
+ argument);
+ png_imagep image = display->image;
+ png_structrp png_ptr = image->opaque->png_ptr;
+ int passes;
+
+ /* Called when the libpng data must be transformed into the color-mapped
+ * form. There is a local row buffer in display->local and this routine must
+ * do the interlace handling.
+ */
+ switch (png_ptr->interlaced)
+ {
+ case PNG_INTERLACE_NONE:
+ passes = 1;
+ break;
+
+ case PNG_INTERLACE_ADAM7:
+ passes = PNG_INTERLACE_ADAM7_PASSES;
+ break;
+
+ default:
+ png_error(png_ptr, "unknown interlace type");
+ }
+
+ {
+ png_uint_32 height = image->height;
+ png_uint_32 width = image->width;
+ int proc = display->colormap_processing;
+ png_bytep first_row = png_voidcast(png_bytep, display->first_row);
+ ptrdiff_t step_row = display->row_bytes;
+ int pass;
+
+ for (pass = 0; pass < passes; ++pass)
+ {
+ unsigned int startx, stepx, stepy;
+ png_uint_32 y;
+
+ if (png_ptr->interlaced == PNG_INTERLACE_ADAM7)
+ {
+ /* The row may be empty for a short image: */
+ if (PNG_PASS_COLS(width, pass) == 0)
+ continue;
+
+ startx = PNG_PASS_START_COL(pass);
+ stepx = PNG_PASS_COL_OFFSET(pass);
+ y = PNG_PASS_START_ROW(pass);
+ stepy = PNG_PASS_ROW_OFFSET(pass);
+ }
+
+ else
+ {
+ y = 0;
+ startx = 0;
+ stepx = stepy = 1;
+ }
+
+ for (; y<height; y += stepy)
+ {
+ png_bytep inrow = png_voidcast(png_bytep, display->local_row);
+ png_bytep outrow = first_row + y * step_row;
+ png_const_bytep end_row = outrow + width;
+
+ /* Read read the libpng data into the temporary buffer. */
+ png_read_row(png_ptr, inrow, NULL);
+
+ /* Now process the row according to the processing option, note
+ * that the caller verifies that the format of the libpng output
+ * data is as required.
+ */
+ outrow += startx;
+ switch (proc)
+ {
+ case PNG_CMAP_GA:
+ for (; outrow < end_row; outrow += stepx)
+ {
+ /* The data is always in the PNG order */
+ unsigned int gray = *inrow++;
+ unsigned int alpha = *inrow++;
+ unsigned int entry;
+
+ /* NOTE: this code is copied as a comment in
+ * make_ga_colormap above. Please update the
+ * comment if you change this code!
+ */
+ if (alpha > 229) /* opaque */
+ {
+ entry = (231 * gray + 128) >> 8;
+ }
+ else if (alpha < 26) /* transparent */
+ {
+ entry = 231;
+ }
+ else /* partially opaque */
+ {
+ entry = 226 + 6 * PNG_DIV51(alpha) + PNG_DIV51(gray);
+ }
+
+ *outrow = (png_byte)entry;
+ }
+ break;
+
+ case PNG_CMAP_TRANS:
+ for (; outrow < end_row; outrow += stepx)
+ {
+ png_byte gray = *inrow++;
+ png_byte alpha = *inrow++;
+
+ if (alpha == 0)
+ *outrow = PNG_CMAP_TRANS_BACKGROUND;
+
+ else if (gray != PNG_CMAP_TRANS_BACKGROUND)
+ *outrow = gray;
+
+ else
+ *outrow = (png_byte)(PNG_CMAP_TRANS_BACKGROUND+1);
+ }
+ break;
+
+ case PNG_CMAP_RGB:
+ for (; outrow < end_row; outrow += stepx)
+ {
+ *outrow = PNG_RGB_INDEX(inrow[0], inrow[1], inrow[2]);
+ inrow += 3;
+ }
+ break;
+
+ case PNG_CMAP_RGB_ALPHA:
+ for (; outrow < end_row; outrow += stepx)
+ {
+ unsigned int alpha = inrow[3];
+
+ /* Because the alpha entries only hold alpha==0.5 values
+ * split the processing at alpha==0.25 (64) and 0.75
+ * (196).
+ */
+
+ if (alpha >= 196)
+ *outrow = PNG_RGB_INDEX(inrow[0], inrow[1],
+ inrow[2]);
+
+ else if (alpha < 64)
+ *outrow = PNG_CMAP_RGB_ALPHA_BACKGROUND;
+
+ else
+ {
+ /* Likewise there are three entries for each of r, g
+ * and b. We could select the entry by popcount on
+ * the top two bits on those architectures that
+ * support it, this is what the code below does,
+ * crudely.
+ */
+ unsigned int back_i = PNG_CMAP_RGB_ALPHA_BACKGROUND+1;
+
+ /* Here are how the values map:
+ *
+ * 0x00 .. 0x3f -> 0
+ * 0x40 .. 0xbf -> 1
+ * 0xc0 .. 0xff -> 2
+ *
+ * So, as above with the explicit alpha checks, the
+ * breakpoints are at 64 and 196.
+ */
+ if (inrow[0] & 0x80) back_i += 9; /* red */
+ if (inrow[0] & 0x40) back_i += 9;
+ if (inrow[0] & 0x80) back_i += 3; /* green */
+ if (inrow[0] & 0x40) back_i += 3;
+ if (inrow[0] & 0x80) back_i += 1; /* blue */
+ if (inrow[0] & 0x40) back_i += 1;
+
+ *outrow = (png_byte)back_i;
+ }
+
+ inrow += 4;
+ }
+ break;
+
+ default:
+ break;
+ }
+ }
+ }
+ }
+
+ return 1;
+}
+
+static int
+png_image_read_colormapped(png_voidp argument)
+{
+ png_image_read_control *display = png_voidcast(png_image_read_control*,
+ argument);
+ png_imagep image = display->image;
+ png_controlp control = image->opaque;
+ png_structrp png_ptr = control->png_ptr;
+ png_inforp info_ptr = control->info_ptr;
+
+ int passes = 0; /* As a flag */
+
+ PNG_SKIP_CHUNKS(png_ptr);
+
+ /* Update the 'info' structure and make sure the result is as required; first
+ * make sure to turn on the interlace handling if it will be required
+ * (because it can't be turned on *after* the call to png_read_update_info!)
+ */
+ if (display->colormap_processing == PNG_CMAP_NONE)
+ passes = png_set_interlace_handling(png_ptr);
+
+ png_read_update_info(png_ptr, info_ptr);
+
+ /* The expected output can be deduced from the colormap_processing option. */
+ switch (display->colormap_processing)
+ {
+ case PNG_CMAP_NONE:
+ /* Output must be one channel and one byte per pixel, the output
+ * encoding can be anything.
+ */
+ if ((info_ptr->color_type == PNG_COLOR_TYPE_PALETTE ||
+ info_ptr->color_type == PNG_COLOR_TYPE_GRAY) &&
+ info_ptr->bit_depth == 8)
+ break;
+
+ goto bad_output;
+
+ case PNG_CMAP_TRANS:
+ case PNG_CMAP_GA:
+ /* Output must be two channels and the 'G' one must be sRGB, the latter
+ * can be checked with an exact number because it should have been set
+ * to this number above!
+ */
+ if (info_ptr->color_type == PNG_COLOR_TYPE_GRAY_ALPHA &&
+ info_ptr->bit_depth == 8 &&
+ png_ptr->screen_gamma == PNG_GAMMA_sRGB &&
+ image->colormap_entries == 256)
+ break;
+
+ goto bad_output;
+
+ case PNG_CMAP_RGB:
+ /* Output must be 8-bit sRGB encoded RGB */
+ if (info_ptr->color_type == PNG_COLOR_TYPE_RGB &&
+ info_ptr->bit_depth == 8 &&
+ png_ptr->screen_gamma == PNG_GAMMA_sRGB &&
+ image->colormap_entries == 216)
+ break;
+
+ goto bad_output;
+
+ case PNG_CMAP_RGB_ALPHA:
+ /* Output must be 8-bit sRGB encoded RGBA */
+ if (info_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA &&
+ info_ptr->bit_depth == 8 &&
+ png_ptr->screen_gamma == PNG_GAMMA_sRGB &&
+ image->colormap_entries == 244 /* 216 + 1 + 27 */)
+ break;
+
+ /* goto bad_output; */
+ /* FALL THROUGH */
+
+ default:
+ bad_output:
+ png_error(png_ptr, "bad color-map processing (internal error)");
+ }
+
+ /* Now read the rows. Do this here if it is possible to read directly into
+ * the output buffer, otherwise allocate a local row buffer of the maximum
+ * size libpng requires and call the relevant processing routine safely.
+ */
+ {
+ png_voidp first_row = display->buffer;
+ ptrdiff_t row_bytes = display->row_stride;
+
+ /* The following expression is designed to work correctly whether it gives
+ * a signed or an unsigned result.
+ */
+ if (row_bytes < 0)
+ {
+ char *ptr = png_voidcast(char*, first_row);
+ ptr += (image->height-1) * (-row_bytes);
+ first_row = png_voidcast(png_voidp, ptr);
+ }
+
+ display->first_row = first_row;
+ display->row_bytes = row_bytes;
+ }
+
+ if (passes == 0)
+ {
+ int result;
+ png_voidp row = png_malloc(png_ptr, png_get_rowbytes(png_ptr, info_ptr));
+
+ display->local_row = row;
+ result = png_safe_execute(image, png_image_read_and_map, display);
+ display->local_row = NULL;
+ png_free(png_ptr, row);
+
+ return result;
+ }
+
+ else
+ {
+ png_alloc_size_t row_bytes = display->row_bytes;
+
+ while (--passes >= 0)
+ {
+ png_uint_32 y = image->height;
+ png_bytep row = png_voidcast(png_bytep, display->first_row);
+
+ while (y-- > 0)
+ {
+ png_read_row(png_ptr, row, NULL);
+ row += row_bytes;
+ }
+ }
+
+ return 1;
+ }
+}
+
+/* Just the row reading part of png_image_read. */
+static int
+png_image_read_composite(png_voidp argument)
+{
+ png_image_read_control *display = png_voidcast(png_image_read_control*,
+ argument);
+ png_imagep image = display->image;
+ png_structrp png_ptr = image->opaque->png_ptr;
+ int passes;
+
+ switch (png_ptr->interlaced)
+ {
+ case PNG_INTERLACE_NONE:
+ passes = 1;
+ break;
+
+ case PNG_INTERLACE_ADAM7:
+ passes = PNG_INTERLACE_ADAM7_PASSES;
+ break;
+
+ default:
+ png_error(png_ptr, "unknown interlace type");
+ }
+
+ {
+ png_uint_32 height = image->height;
+ png_uint_32 width = image->width;
+ ptrdiff_t step_row = display->row_bytes;
+ unsigned int channels =
+ (image->format & PNG_FORMAT_FLAG_COLOR) != 0 ? 3 : 1;
+ int pass;
+
+ for (pass = 0; pass < passes; ++pass)
+ {
+ unsigned int startx, stepx, stepy;
+ png_uint_32 y;
+
+ if (png_ptr->interlaced == PNG_INTERLACE_ADAM7)
+ {
+ /* The row may be empty for a short image: */
+ if (PNG_PASS_COLS(width, pass) == 0)
+ continue;
+
+ startx = PNG_PASS_START_COL(pass) * channels;
+ stepx = PNG_PASS_COL_OFFSET(pass) * channels;
+ y = PNG_PASS_START_ROW(pass);
+ stepy = PNG_PASS_ROW_OFFSET(pass);
+ }
+
+ else
+ {
+ y = 0;
+ startx = 0;
+ stepx = channels;
+ stepy = 1;
+ }
+
+ for (; y<height; y += stepy)
+ {
+ png_bytep inrow = png_voidcast(png_bytep, display->local_row);
+ png_bytep outrow;
+ png_const_bytep end_row;
+
+ /* Read the row, which is packed: */
+ png_read_row(png_ptr, inrow, NULL);
+
+ outrow = png_voidcast(png_bytep, display->first_row);
+ outrow += y * step_row;
+ end_row = outrow + width * channels;
+
+ /* Now do the composition on each pixel in this row. */
+ outrow += startx;
+ for (; outrow < end_row; outrow += stepx)
+ {
+ png_byte alpha = inrow[channels];
+
+ if (alpha > 0) /* else no change to the output */
+ {
+ unsigned int c;
+
+ for (c=0; c<channels; ++c)
+ {
+ png_uint_32 component = inrow[c];
+
+ if (alpha < 255) /* else just use component */
+ {
+ /* This is PNG_OPTIMIZED_ALPHA, the component value
+ * is a linear 8-bit value. Combine this with the
+ * current outrow[c] value which is sRGB encoded.
+ * Arithmetic here is 16-bits to preserve the output
+ * values correctly.
+ */
+ component *= 257*255; /* =65535 */
+ component += (255-alpha)*png_sRGB_table[outrow[c]];
+
+ /* So 'component' is scaled by 255*65535 and is
+ * therefore appropriate for the sRGB to linear
+ * conversion table.
+ */
+ component = PNG_sRGB_FROM_LINEAR(component);
+ }
+
+ outrow[c] = (png_byte)component;
+ }
+ }
+
+ inrow += channels+1; /* components and alpha channel */
+ }
+ }
+ }
+ }
+
+ return 1;
+}
+
+/* The do_local_background case; called when all the following transforms are to
+ * be done:
+ *
+ * PNG_RGB_TO_GRAY
+ * PNG_COMPOSITE
+ * PNG_GAMMA
+ *
+ * This is a work-around for the fact that both the PNG_RGB_TO_GRAY and
+ * PNG_COMPOSITE code performs gamma correction, so we get double gamma
+ * correction. The fix-up is to prevent the PNG_COMPOSITE operation from
+ * happening inside libpng, so this routine sees an 8 or 16-bit gray+alpha
+ * row and handles the removal or pre-multiplication of the alpha channel.
+ */
+static int
+png_image_read_background(png_voidp argument)
+{
+ png_image_read_control *display = png_voidcast(png_image_read_control*,
+ argument);
+ png_imagep image = display->image;
+ png_structrp png_ptr = image->opaque->png_ptr;
+ png_inforp info_ptr = image->opaque->info_ptr;
+ png_uint_32 height = image->height;
+ png_uint_32 width = image->width;
+ int pass, passes;
+
+ /* Double check the convoluted logic below. We expect to get here with
+ * libpng doing rgb to gray and gamma correction but background processing
+ * left to the png_image_read_background function. The rows libpng produce
+ * might be 8 or 16-bit but should always have two channels; gray plus alpha.
+ */
+ if ((png_ptr->transformations & PNG_RGB_TO_GRAY) == 0)
+ png_error(png_ptr, "lost rgb to gray");
+
+ if ((png_ptr->transformations & PNG_COMPOSE) != 0)
+ png_error(png_ptr, "unexpected compose");
+
+ if (png_get_channels(png_ptr, info_ptr) != 2)
+ png_error(png_ptr, "lost/gained channels");
+
+ /* Expect the 8-bit case to always remove the alpha channel */
+ if ((image->format & PNG_FORMAT_FLAG_LINEAR) == 0 &&
+ (image->format & PNG_FORMAT_FLAG_ALPHA) != 0)
+ png_error(png_ptr, "unexpected 8-bit transformation");
+
+ switch (png_ptr->interlaced)
+ {
+ case PNG_INTERLACE_NONE:
+ passes = 1;
+ break;
+
+ case PNG_INTERLACE_ADAM7:
+ passes = PNG_INTERLACE_ADAM7_PASSES;
+ break;
+
+ default:
+ png_error(png_ptr, "unknown interlace type");
+ }
+
+ /* Use direct access to info_ptr here because otherwise the simplified API
+ * would require PNG_EASY_ACCESS_SUPPORTED (just for this.) Note this is
+ * checking the value after libpng expansions, not the original value in the
+ * PNG.
+ */
+ switch (info_ptr->bit_depth)
+ {
+ case 8:
+ /* 8-bit sRGB gray values with an alpha channel; the alpha channel is
+ * to be removed by composing on a background: either the row if
+ * display->background is NULL or display->background->green if not.
+ * Unlike the code above ALPHA_OPTIMIZED has *not* been done.
+ */
+ {
+ png_bytep first_row = png_voidcast(png_bytep, display->first_row);
+ ptrdiff_t step_row = display->row_bytes;
+
+ for (pass = 0; pass < passes; ++pass)
+ {
+ png_bytep row = png_voidcast(png_bytep,
+ display->first_row);
+ unsigned int startx, stepx, stepy;
+ png_uint_32 y;
+
+ if (png_ptr->interlaced == PNG_INTERLACE_ADAM7)
+ {
+ /* The row may be empty for a short image: */
+ if (PNG_PASS_COLS(width, pass) == 0)
+ continue;
+
+ startx = PNG_PASS_START_COL(pass);
+ stepx = PNG_PASS_COL_OFFSET(pass);
+ y = PNG_PASS_START_ROW(pass);
+ stepy = PNG_PASS_ROW_OFFSET(pass);
+ }
+
+ else
+ {
+ y = 0;
+ startx = 0;
+ stepx = stepy = 1;
+ }
+
+ if (display->background == NULL)
+ {
+ for (; y<height; y += stepy)
+ {
+ png_bytep inrow = png_voidcast(png_bytep,
+ display->local_row);
+ png_bytep outrow = first_row + y * step_row;
+ png_const_bytep end_row = outrow + width;
+
+ /* Read the row, which is packed: */
+ png_read_row(png_ptr, inrow, NULL);
+
+ /* Now do the composition on each pixel in this row. */
+ outrow += startx;
+ for (; outrow < end_row; outrow += stepx)
+ {
+ png_byte alpha = inrow[1];
+
+ if (alpha > 0) /* else no change to the output */
+ {
+ png_uint_32 component = inrow[0];
+
+ if (alpha < 255) /* else just use component */
+ {
+ /* Since PNG_OPTIMIZED_ALPHA was not set it is
+ * necessary to invert the sRGB transfer
+ * function and multiply the alpha out.
+ */
+ component = png_sRGB_table[component] * alpha;
+ component += png_sRGB_table[outrow[0]] *
+ (255-alpha);
+ component = PNG_sRGB_FROM_LINEAR(component);
+ }
+
+ outrow[0] = (png_byte)component;
+ }
+
+ inrow += 2; /* gray and alpha channel */
+ }
+ }
+ }
+
+ else /* constant background value */
+ {
+ png_byte background8 = display->background->green;
+ png_uint_16 background = png_sRGB_table[background8];
+
+ for (; y<height; y += stepy)
+ {
+ png_bytep inrow = png_voidcast(png_bytep,
+ display->local_row);
+ png_bytep outrow = first_row + y * step_row;
+ png_const_bytep end_row = outrow + width;
+
+ /* Read the row, which is packed: */
+ png_read_row(png_ptr, inrow, NULL);
+
+ /* Now do the composition on each pixel in this row. */
+ outrow += startx;
+ for (; outrow < end_row; outrow += stepx)
+ {
+ png_byte alpha = inrow[1];
+
+ if (alpha > 0) /* else use background */
+ {
+ png_uint_32 component = inrow[0];
+
+ if (alpha < 255) /* else just use component */
+ {
+ component = png_sRGB_table[component] * alpha;
+ component += background * (255-alpha);
+ component = PNG_sRGB_FROM_LINEAR(component);
+ }
+
+ outrow[0] = (png_byte)component;
+ }
+
+ else
+ outrow[0] = background8;
+
+ inrow += 2; /* gray and alpha channel */
+ }
+
+ row += display->row_bytes;
+ }
+ }
+ }
+ }
+ break;
+
+ case 16:
+ /* 16-bit linear with pre-multiplied alpha; the pre-multiplication must
+ * still be done and, maybe, the alpha channel removed. This code also
+ * handles the alpha-first option.
+ */
+ {
+ png_uint_16p first_row = png_voidcast(png_uint_16p,
+ display->first_row);
+ /* The division by two is safe because the caller passed in a
+ * stride which was multiplied by 2 (below) to get row_bytes.
+ */
+ ptrdiff_t step_row = display->row_bytes / 2;
+ int preserve_alpha = (image->format & PNG_FORMAT_FLAG_ALPHA) != 0;
+ unsigned int outchannels = 1+preserve_alpha;
+ int swap_alpha = 0;
+
+# ifdef PNG_SIMPLIFIED_READ_AFIRST_SUPPORTED
+ if (preserve_alpha != 0 &&
+ (image->format & PNG_FORMAT_FLAG_AFIRST) != 0)
+ swap_alpha = 1;
+# endif
+
+ for (pass = 0; pass < passes; ++pass)
+ {
+ unsigned int startx, stepx, stepy;
+ png_uint_32 y;
+
+ /* The 'x' start and step are adjusted to output components here.
+ */
+ if (png_ptr->interlaced == PNG_INTERLACE_ADAM7)
+ {
+ /* The row may be empty for a short image: */
+ if (PNG_PASS_COLS(width, pass) == 0)
+ continue;
+
+ startx = PNG_PASS_START_COL(pass) * outchannels;
+ stepx = PNG_PASS_COL_OFFSET(pass) * outchannels;
+ y = PNG_PASS_START_ROW(pass);
+ stepy = PNG_PASS_ROW_OFFSET(pass);
+ }
+
+ else
+ {
+ y = 0;
+ startx = 0;
+ stepx = outchannels;
+ stepy = 1;
+ }
+
+ for (; y<height; y += stepy)
+ {
+ png_const_uint_16p inrow;
+ png_uint_16p outrow = first_row + y*step_row;
+ png_uint_16p end_row = outrow + width * outchannels;
+
+ /* Read the row, which is packed: */
+ png_read_row(png_ptr, png_voidcast(png_bytep,
+ display->local_row), NULL);
+ inrow = png_voidcast(png_const_uint_16p, display->local_row);
+
+ /* Now do the pre-multiplication on each pixel in this row.
+ */
+ outrow += startx;
+ for (; outrow < end_row; outrow += stepx)
+ {
+ png_uint_32 component = inrow[0];
+ png_uint_16 alpha = inrow[1];
+
+ if (alpha > 0) /* else 0 */
+ {
+ if (alpha < 65535) /* else just use component */
+ {
+ component *= alpha;
+ component += 32767;
+ component /= 65535;
+ }
+ }
+
+ else
+ component = 0;
+
+ outrow[swap_alpha] = (png_uint_16)component;
+ if (preserve_alpha != 0)
+ outrow[1 ^ swap_alpha] = alpha;
+
+ inrow += 2; /* components and alpha channel */
+ }
+ }
+ }
+ }
+ break;
+
+#ifdef __GNUC__
+ default:
+ png_error(png_ptr, "unexpected bit depth");
+#endif
+ }
+
+ return 1;
+}
+
+/* The guts of png_image_finish_read as a png_safe_execute callback. */
+static int
+png_image_read_direct(png_voidp argument)
+{
+ png_image_read_control *display = png_voidcast(png_image_read_control*,
+ argument);
+ png_imagep image = display->image;
+ png_structrp png_ptr = image->opaque->png_ptr;
+ png_inforp info_ptr = image->opaque->info_ptr;
+
+ png_uint_32 format = image->format;
+ int linear = (format & PNG_FORMAT_FLAG_LINEAR) != 0;
+ int do_local_compose = 0;
+ int do_local_background = 0; /* to avoid double gamma correction bug */
+ int passes = 0;
+
+ /* Add transforms to ensure the correct output format is produced then check
+ * that the required implementation support is there. Always expand; always
+ * need 8 bits minimum, no palette and expanded tRNS.
+ */
+ png_set_expand(png_ptr);
+
+ /* Now check the format to see if it was modified. */
+ {
+ png_uint_32 base_format = png_image_format(png_ptr) &
+ ~PNG_FORMAT_FLAG_COLORMAP /* removed by png_set_expand */;
+ png_uint_32 change = format ^ base_format;
+ png_fixed_point output_gamma;
+ int mode; /* alpha mode */
+
+ /* Do this first so that we have a record if rgb to gray is happening. */
+ if ((change & PNG_FORMAT_FLAG_COLOR) != 0)
+ {
+ /* gray<->color transformation required. */
+ if ((format & PNG_FORMAT_FLAG_COLOR) != 0)
+ png_set_gray_to_rgb(png_ptr);
+
+ else
+ {
+ /* libpng can't do both rgb to gray and
+ * background/pre-multiplication if there is also significant gamma
+ * correction, because both operations require linear colors and
+ * the code only supports one transform doing the gamma correction.
+ * Handle this by doing the pre-multiplication or background
+ * operation in this code, if necessary.
+ *
+ * TODO: fix this by rewriting pngrtran.c (!)
+ *
+ * For the moment (given that fixing this in pngrtran.c is an
+ * enormous change) 'do_local_background' is used to indicate that
+ * the problem exists.
+ */
+ if ((base_format & PNG_FORMAT_FLAG_ALPHA) != 0)
+ do_local_background = 1/*maybe*/;
+
+ png_set_rgb_to_gray_fixed(png_ptr, PNG_ERROR_ACTION_NONE,
+ PNG_RGB_TO_GRAY_DEFAULT, PNG_RGB_TO_GRAY_DEFAULT);
+ }
+
+ change &= ~PNG_FORMAT_FLAG_COLOR;
+ }
+
+ /* Set the gamma appropriately, linear for 16-bit input, sRGB otherwise.
+ */
+ {
+ png_fixed_point input_gamma_default;
+
+ if ((base_format & PNG_FORMAT_FLAG_LINEAR) != 0 &&
+ (image->flags & PNG_IMAGE_FLAG_16BIT_sRGB) == 0)
+ input_gamma_default = PNG_GAMMA_LINEAR;
+ else
+ input_gamma_default = PNG_DEFAULT_sRGB;
+
+ /* Call png_set_alpha_mode to set the default for the input gamma; the
+ * output gamma is set by a second call below.
+ */
+ png_set_alpha_mode_fixed(png_ptr, PNG_ALPHA_PNG, input_gamma_default);
+ }
+
+ if (linear != 0)
+ {
+ /* If there *is* an alpha channel in the input it must be multiplied
+ * out; use PNG_ALPHA_STANDARD, otherwise just use PNG_ALPHA_PNG.
+ */
+ if ((base_format & PNG_FORMAT_FLAG_ALPHA) != 0)
+ mode = PNG_ALPHA_STANDARD; /* associated alpha */
+
+ else
+ mode = PNG_ALPHA_PNG;
+
+ output_gamma = PNG_GAMMA_LINEAR;
+ }
+
+ else
+ {
+ mode = PNG_ALPHA_PNG;
+ output_gamma = PNG_DEFAULT_sRGB;
+ }
+
+ /* If 'do_local_background' is set check for the presence of gamma
+ * correction; this is part of the work-round for the libpng bug
+ * described above.
+ *
+ * TODO: fix libpng and remove this.
+ */
+ if (do_local_background != 0)
+ {
+ png_fixed_point gtest;
+
+ /* This is 'png_gamma_threshold' from pngrtran.c; the test used for
+ * gamma correction, the screen gamma hasn't been set on png_struct
+ * yet; it's set below. png_struct::gamma, however, is set to the
+ * final value.
+ */
+ if (png_muldiv(>est, output_gamma, png_ptr->colorspace.gamma,
+ PNG_FP_1) != 0 && png_gamma_significant(gtest) == 0)
+ do_local_background = 0;
+
+ else if (mode == PNG_ALPHA_STANDARD)
+ {
+ do_local_background = 2/*required*/;
+ mode = PNG_ALPHA_PNG; /* prevent libpng doing it */
+ }
+
+ /* else leave as 1 for the checks below */
+ }
+
+ /* If the bit-depth changes then handle that here. */
+ if ((change & PNG_FORMAT_FLAG_LINEAR) != 0)
+ {
+ if (linear != 0 /*16-bit output*/)
+ png_set_expand_16(png_ptr);
+
+ else /* 8-bit output */
+ png_set_scale_16(png_ptr);
+
+ change &= ~PNG_FORMAT_FLAG_LINEAR;
+ }
+
+ /* Now the background/alpha channel changes. */
+ if ((change & PNG_FORMAT_FLAG_ALPHA) != 0)
+ {
+ /* Removing an alpha channel requires composition for the 8-bit
+ * formats; for the 16-bit it is already done, above, by the
+ * pre-multiplication and the channel just needs to be stripped.
+ */
+ if ((base_format & PNG_FORMAT_FLAG_ALPHA) != 0)
+ {
+ /* If RGB->gray is happening the alpha channel must be left and the
+ * operation completed locally.
+ *
+ * TODO: fix libpng and remove this.
+ */
+ if (do_local_background != 0)
+ do_local_background = 2/*required*/;
+
+ /* 16-bit output: just remove the channel */
+ else if (linear != 0) /* compose on black (well, pre-multiply) */
+ png_set_strip_alpha(png_ptr);
+
+ /* 8-bit output: do an appropriate compose */
+ else if (display->background != NULL)
+ {
+ png_color_16 c;
+
+ c.index = 0; /*unused*/
+ c.red = display->background->red;
+ c.green = display->background->green;
+ c.blue = display->background->blue;
+ c.gray = display->background->green;
+
+ /* This is always an 8-bit sRGB value, using the 'green' channel
+ * for gray is much better than calculating the luminance here;
+ * we can get off-by-one errors in that calculation relative to
+ * the app expectations and that will show up in transparent
+ * pixels.
+ */
+ png_set_background_fixed(png_ptr, &c,
+ PNG_BACKGROUND_GAMMA_SCREEN, 0/*need_expand*/,
+ 0/*gamma: not used*/);
+ }
+
+ else /* compose on row: implemented below. */
+ {
+ do_local_compose = 1;
+ /* This leaves the alpha channel in the output, so it has to be
+ * removed by the code below. Set the encoding to the 'OPTIMIZE'
+ * one so the code only has to hack on the pixels that require
+ * composition.
+ */
+ mode = PNG_ALPHA_OPTIMIZED;
+ }
+ }
+
+ else /* output needs an alpha channel */
+ {
+ /* This is tricky because it happens before the swap operation has
+ * been accomplished; however, the swap does *not* swap the added
+ * alpha channel (weird API), so it must be added in the correct
+ * place.
+ */
+ png_uint_32 filler; /* opaque filler */
+ int where;
+
+ if (linear != 0)
+ filler = 65535;
+
+ else
+ filler = 255;
+
+# ifdef PNG_FORMAT_AFIRST_SUPPORTED
+ if ((format & PNG_FORMAT_FLAG_AFIRST) != 0)
+ {
+ where = PNG_FILLER_BEFORE;
+ change &= ~PNG_FORMAT_FLAG_AFIRST;
+ }
+
+ else
+# endif
+ where = PNG_FILLER_AFTER;
+
+ png_set_add_alpha(png_ptr, filler, where);
+ }
+
+ /* This stops the (irrelevant) call to swap_alpha below. */
+ change &= ~PNG_FORMAT_FLAG_ALPHA;
+ }
+
+ /* Now set the alpha mode correctly; this is always done, even if there is
+ * no alpha channel in either the input or the output because it correctly
+ * sets the output gamma.
+ */
+ png_set_alpha_mode_fixed(png_ptr, mode, output_gamma);
+
+# ifdef PNG_FORMAT_BGR_SUPPORTED
+ if ((change & PNG_FORMAT_FLAG_BGR) != 0)
+ {
+ /* Check only the output format; PNG is never BGR; don't do this if
+ * the output is gray, but fix up the 'format' value in that case.
+ */
+ if ((format & PNG_FORMAT_FLAG_COLOR) != 0)
+ png_set_bgr(png_ptr);
+
+ else
+ format &= ~PNG_FORMAT_FLAG_BGR;
+
+ change &= ~PNG_FORMAT_FLAG_BGR;
+ }
+# endif
+
+# ifdef PNG_FORMAT_AFIRST_SUPPORTED
+ if ((change & PNG_FORMAT_FLAG_AFIRST) != 0)
+ {
+ /* Only relevant if there is an alpha channel - it's particularly
+ * important to handle this correctly because do_local_compose may
+ * be set above and then libpng will keep the alpha channel for this
+ * code to remove.
+ */
+ if ((format & PNG_FORMAT_FLAG_ALPHA) != 0)
+ {
+ /* Disable this if doing a local background,
+ * TODO: remove this when local background is no longer required.
+ */
+ if (do_local_background != 2)
+ png_set_swap_alpha(png_ptr);
+ }
+
+ else
+ format &= ~PNG_FORMAT_FLAG_AFIRST;
+
+ change &= ~PNG_FORMAT_FLAG_AFIRST;
+ }
+# endif
+
+ /* If the *output* is 16-bit then we need to check for a byte-swap on this
+ * architecture.
+ */
+ if (linear != 0)
+ {
+ PNG_CONST png_uint_16 le = 0x0001;
+
+ if ((*(png_const_bytep) & le) != 0)
+ png_set_swap(png_ptr);
+ }
+
+ /* If change is not now 0 some transformation is missing - error out. */
+ if (change != 0)
+ png_error(png_ptr, "png_read_image: unsupported transformation");
+ }
+
+ PNG_SKIP_CHUNKS(png_ptr);
+
+ /* Update the 'info' structure and make sure the result is as required; first
+ * make sure to turn on the interlace handling if it will be required
+ * (because it can't be turned on *after* the call to png_read_update_info!)
+ *
+ * TODO: remove the do_local_background fixup below.
+ */
+ if (do_local_compose == 0 && do_local_background != 2)
+ passes = png_set_interlace_handling(png_ptr);
+
+ png_read_update_info(png_ptr, info_ptr);
+
+ {
+ png_uint_32 info_format = 0;
+
+ if ((info_ptr->color_type & PNG_COLOR_MASK_COLOR) != 0)
+ info_format |= PNG_FORMAT_FLAG_COLOR;
+
+ if ((info_ptr->color_type & PNG_COLOR_MASK_ALPHA) != 0)
+ {
+ /* do_local_compose removes this channel below. */
+ if (do_local_compose == 0)
+ {
+ /* do_local_background does the same if required. */
+ if (do_local_background != 2 ||
+ (format & PNG_FORMAT_FLAG_ALPHA) != 0)
+ info_format |= PNG_FORMAT_FLAG_ALPHA;
+ }
+ }
+
+ else if (do_local_compose != 0) /* internal error */
+ png_error(png_ptr, "png_image_read: alpha channel lost");
+
+ if (info_ptr->bit_depth == 16)
+ info_format |= PNG_FORMAT_FLAG_LINEAR;
+
+# ifdef PNG_FORMAT_BGR_SUPPORTED
+ if ((png_ptr->transformations & PNG_BGR) != 0)
+ info_format |= PNG_FORMAT_FLAG_BGR;
+# endif
+
+# ifdef PNG_FORMAT_AFIRST_SUPPORTED
+ if (do_local_background == 2)
+ {
+ if ((format & PNG_FORMAT_FLAG_AFIRST) != 0)
+ info_format |= PNG_FORMAT_FLAG_AFIRST;
+ }
+
+ if ((png_ptr->transformations & PNG_SWAP_ALPHA) != 0 ||
+ ((png_ptr->transformations & PNG_ADD_ALPHA) != 0 &&
+ (png_ptr->flags & PNG_FLAG_FILLER_AFTER) == 0))
+ {
+ if (do_local_background == 2)
+ png_error(png_ptr, "unexpected alpha swap transformation");
+
+ info_format |= PNG_FORMAT_FLAG_AFIRST;
+ }
+# endif
+
+ /* This is actually an internal error. */
+ if (info_format != format)
+ png_error(png_ptr, "png_read_image: invalid transformations");
+ }
+
+ /* Now read the rows. If do_local_compose is set then it is necessary to use
+ * a local row buffer. The output will be GA, RGBA or BGRA and must be
+ * converted to G, RGB or BGR as appropriate. The 'local_row' member of the
+ * display acts as a flag.
+ */
+ {
+ png_voidp first_row = display->buffer;
+ ptrdiff_t row_bytes = display->row_stride;
+
+ if (linear != 0)
+ row_bytes *= 2;
+
+ /* The following expression is designed to work correctly whether it gives
+ * a signed or an unsigned result.
+ */
+ if (row_bytes < 0)
+ {
+ char *ptr = png_voidcast(char*, first_row);
+ ptr += (image->height-1) * (-row_bytes);
+ first_row = png_voidcast(png_voidp, ptr);
+ }
+
+ display->first_row = first_row;
+ display->row_bytes = row_bytes;
+ }
+
+ if (do_local_compose != 0)
+ {
+ int result;
+ png_voidp row = png_malloc(png_ptr, png_get_rowbytes(png_ptr, info_ptr));
+
+ display->local_row = row;
+ result = png_safe_execute(image, png_image_read_composite, display);
+ display->local_row = NULL;
+ png_free(png_ptr, row);
+
+ return result;
+ }
+
+ else if (do_local_background == 2)
+ {
+ int result;
+ png_voidp row = png_malloc(png_ptr, png_get_rowbytes(png_ptr, info_ptr));
+
+ display->local_row = row;
+ result = png_safe_execute(image, png_image_read_background, display);
+ display->local_row = NULL;
+ png_free(png_ptr, row);
+
+ return result;
+ }
+
+ else
+ {
+ png_alloc_size_t row_bytes = display->row_bytes;
+
+ while (--passes >= 0)
+ {
+ png_uint_32 y = image->height;
+ png_bytep row = png_voidcast(png_bytep, display->first_row);
+
+ while (y-- > 0)
+ {
+ png_read_row(png_ptr, row, NULL);
+ row += row_bytes;
+ }
+ }
+
+ return 1;
+ }
+}
+
+int PNGAPI
+png_image_finish_read(png_imagep image, png_const_colorp background,
+ void *buffer, png_int_32 row_stride, void *colormap)
+{
+ if (image != NULL && image->version == PNG_IMAGE_VERSION)
+ {
+ png_uint_32 check;
+
+ if (row_stride == 0)
+ row_stride = PNG_IMAGE_ROW_STRIDE(*image);
+
+ if (row_stride < 0)
+ check = -row_stride;
+
+ else
+ check = row_stride;
+
+ if (image->opaque != NULL && buffer != NULL &&
+ check >= PNG_IMAGE_ROW_STRIDE(*image))
+ {
+ if ((image->format & PNG_FORMAT_FLAG_COLORMAP) == 0 ||
+ (image->colormap_entries > 0 && colormap != NULL))
+ {
+ int result;
+ png_image_read_control display;
+
+ memset(&display, 0, (sizeof display));
+ display.image = image;
+ display.buffer = buffer;
+ display.row_stride = row_stride;
+ display.colormap = colormap;
+ display.background = background;
+ display.local_row = NULL;
+
+ /* Choose the correct 'end' routine; for the color-map case all the
+ * setup has already been done.
+ */
+ if ((image->format & PNG_FORMAT_FLAG_COLORMAP) != 0)
+ result =
+ png_safe_execute(image, png_image_read_colormap, &display) &&
+ png_safe_execute(image, png_image_read_colormapped, &display);
+
+ else
+ result =
+ png_safe_execute(image, png_image_read_direct, &display);
+
+ png_image_free(image);
+ return result;
+ }
+
+ else
+ return png_image_error(image,
+ "png_image_finish_read[color-map]: no color-map");
+ }
+
+ else
+ return png_image_error(image,
+ "png_image_finish_read: invalid argument");
+ }
+
+ else if (image != NULL)
+ return png_image_error(image,
+ "png_image_finish_read: damaged PNG_IMAGE_VERSION");
+
+ return 0;
+}
+
+#endif /* SIMPLIFIED_READ */
+#endif /* READ */
diff --git a/third_party/lpng_v163/pngrio.c b/third_party/libpng/pngrio.c
similarity index 94%
rename from third_party/lpng_v163/pngrio.c
rename to third_party/libpng/pngrio.c
index d27a26d..38f7fd4 100644
--- a/third_party/lpng_v163/pngrio.c
+++ b/third_party/libpng/pngrio.c
@@ -1,117 +1,120 @@
-/* pngrio.c - functions for data input
- *
- * Last changed in libpng 1.6.0 [February 14, 2013]
- * Copyright (c) 1998-2013 Glenn Randers-Pehrson
- * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
- * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
- *
- * This code is released under the libpng license.
- * For conditions of distribution and use, see the disclaimer
- * and license in png.h
- *
- * This file provides a location for all input. Users who need
- * special handling are expected to write a function that has the same
- * arguments as this and performs a similar function, but that possibly
- * has a different input method. Note that you shouldn't change this
- * function, but rather write a replacement function and then make
- * libpng use it at run time with png_set_read_fn(...).
- */
-
-#include "pngpriv.h"
-
-#ifdef PNG_READ_SUPPORTED
-
-/* Read the data from whatever input you are using. The default routine
- * reads from a file pointer. Note that this routine sometimes gets called
- * with very small lengths, so you should implement some kind of simple
- * buffering if you are using unbuffered reads. This should never be asked
- * to read more then 64K on a 16 bit machine.
- */
-void /* PRIVATE */
-png_read_data(png_structrp png_ptr, png_bytep data, png_size_t length)
-{
- png_debug1(4, "reading %d bytes", (int)length);
-
- if (png_ptr->read_data_fn != NULL)
- (*(png_ptr->read_data_fn))(png_ptr, data, length);
-
- else
- png_error(png_ptr, "Call to NULL read function");
-}
-
-#ifdef PNG_STDIO_SUPPORTED
-/* This is the function that does the actual reading of data. If you are
- * not reading from a standard C stream, you should create a replacement
- * read_data function and use it at run time with png_set_read_fn(), rather
- * than changing the library.
- */
-void PNGCBAPI
-png_default_read_data(png_structp png_ptr, png_bytep data, png_size_t length)
-{
- png_size_t check;
-
- if (png_ptr == NULL)
- return;
-
- /* fread() returns 0 on error, so it is OK to store this in a png_size_t
- * instead of an int, which is what fread() actually returns.
- */
- check = fread(data, 1, length, png_voidcast(png_FILE_p, png_ptr->io_ptr));
-
- if (check != length)
- png_error(png_ptr, "Read Error");
-}
-#endif
-
-/* This function allows the application to supply a new input function
- * for libpng if standard C streams aren't being used.
- *
- * This function takes as its arguments:
- *
- * png_ptr - pointer to a png input data structure
- *
- * io_ptr - pointer to user supplied structure containing info about
- * the input functions. May be NULL.
- *
- * read_data_fn - pointer to a new input function that takes as its
- * arguments a pointer to a png_struct, a pointer to
- * a location where input data can be stored, and a 32-bit
- * unsigned int that is the number of bytes to be read.
- * To exit and output any fatal error messages the new write
- * function should call png_error(png_ptr, "Error msg").
- * May be NULL, in which case libpng's default function will
- * be used.
- */
-void PNGAPI
-png_set_read_fn(png_structrp png_ptr, png_voidp io_ptr,
- png_rw_ptr read_data_fn)
-{
- if (png_ptr == NULL)
- return;
-
- png_ptr->io_ptr = io_ptr;
-
-#ifdef PNG_STDIO_SUPPORTED
- if (read_data_fn != NULL)
- png_ptr->read_data_fn = read_data_fn;
-
- else
- png_ptr->read_data_fn = png_default_read_data;
-#else
- png_ptr->read_data_fn = read_data_fn;
-#endif
-
- /* It is an error to write to a read device */
- if (png_ptr->write_data_fn != NULL)
- {
- png_ptr->write_data_fn = NULL;
- png_warning(png_ptr,
- "Can't set both read_data_fn and write_data_fn in the"
- " same structure");
- }
-
-#ifdef PNG_WRITE_FLUSH_SUPPORTED
- png_ptr->output_flush_fn = NULL;
-#endif
-}
-#endif /* PNG_READ_SUPPORTED */
+
+/* pngrio.c - functions for data input
+ *
+ * Last changed in libpng 1.6.17 [March 26, 2015]
+ * Copyright (c) 1998-2015 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ * This file provides a location for all input. Users who need
+ * special handling are expected to write a function that has the same
+ * arguments as this and performs a similar function, but that possibly
+ * has a different input method. Note that you shouldn't change this
+ * function, but rather write a replacement function and then make
+ * libpng use it at run time with png_set_read_fn(...).
+ */
+
+#include "pngpriv.h"
+
+#ifdef PNG_READ_SUPPORTED
+
+/* Read the data from whatever input you are using. The default routine
+ * reads from a file pointer. Note that this routine sometimes gets called
+ * with very small lengths, so you should implement some kind of simple
+ * buffering if you are using unbuffered reads. This should never be asked
+ * to read more than 64K on a 16-bit machine.
+ */
+void /* PRIVATE */
+png_read_data(png_structrp png_ptr, png_bytep data, png_size_t length)
+{
+ png_debug1(4, "reading %d bytes", (int)length);
+
+ if (png_ptr->read_data_fn != NULL)
+ (*(png_ptr->read_data_fn))(png_ptr, data, length);
+
+ else
+ png_error(png_ptr, "Call to NULL read function");
+}
+
+#ifdef PNG_STDIO_SUPPORTED
+/* This is the function that does the actual reading of data. If you are
+ * not reading from a standard C stream, you should create a replacement
+ * read_data function and use it at run time with png_set_read_fn(), rather
+ * than changing the library.
+ */
+void PNGCBAPI
+png_default_read_data(png_structp png_ptr, png_bytep data, png_size_t length)
+{
+ png_size_t check;
+
+ if (png_ptr == NULL)
+ return;
+
+ /* fread() returns 0 on error, so it is OK to store this in a png_size_t
+ * instead of an int, which is what fread() actually returns.
+ */
+ check = fread(data, 1, length, png_voidcast(png_FILE_p, png_ptr->io_ptr));
+
+ if (check != length)
+ png_error(png_ptr, "Read Error");
+}
+#endif
+
+/* This function allows the application to supply a new input function
+ * for libpng if standard C streams aren't being used.
+ *
+ * This function takes as its arguments:
+ *
+ * png_ptr - pointer to a png input data structure
+ *
+ * io_ptr - pointer to user supplied structure containing info about
+ * the input functions. May be NULL.
+ *
+ * read_data_fn - pointer to a new input function that takes as its
+ * arguments a pointer to a png_struct, a pointer to
+ * a location where input data can be stored, and a 32-bit
+ * unsigned int that is the number of bytes to be read.
+ * To exit and output any fatal error messages the new write
+ * function should call png_error(png_ptr, "Error msg").
+ * May be NULL, in which case libpng's default function will
+ * be used.
+ */
+void PNGAPI
+png_set_read_fn(png_structrp png_ptr, png_voidp io_ptr,
+ png_rw_ptr read_data_fn)
+{
+ if (png_ptr == NULL)
+ return;
+
+ png_ptr->io_ptr = io_ptr;
+
+#ifdef PNG_STDIO_SUPPORTED
+ if (read_data_fn != NULL)
+ png_ptr->read_data_fn = read_data_fn;
+
+ else
+ png_ptr->read_data_fn = png_default_read_data;
+#else
+ png_ptr->read_data_fn = read_data_fn;
+#endif
+
+#ifdef PNG_WRITE_SUPPORTED
+ /* It is an error to write to a read device */
+ if (png_ptr->write_data_fn != NULL)
+ {
+ png_ptr->write_data_fn = NULL;
+ png_warning(png_ptr,
+ "Can't set both read_data_fn and write_data_fn in the"
+ " same structure");
+ }
+#endif
+
+#ifdef PNG_WRITE_FLUSH_SUPPORTED
+ png_ptr->output_flush_fn = NULL;
+#endif
+}
+#endif /* READ */
diff --git a/third_party/lpng_v163/pngrtran.c b/third_party/libpng/pngrtran.c
similarity index 90%
rename from third_party/lpng_v163/pngrtran.c
rename to third_party/libpng/pngrtran.c
index a81034c..f129ef1 100644
--- a/third_party/lpng_v163/pngrtran.c
+++ b/third_party/libpng/pngrtran.c
@@ -1,5102 +1,4997 @@
-/* pngrtran.c - transforms the data in a row for PNG readers
- *
- * Last changed in libpng 1.6.2 [April 25, 2013]
- * Copyright (c) 1998-2013 Glenn Randers-Pehrson
- * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
- * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
- *
- * This code is released under the libpng license.
- * For conditions of distribution and use, see the disclaimer
- * and license in png.h
- *
- * This file contains functions optionally called by an application
- * in order to tell libpng how to handle data when reading a PNG.
- * Transformations that are used in both reading and writing are
- * in pngtrans.c.
- */
-
-#include "pngpriv.h"
-
-#ifdef PNG_READ_SUPPORTED
-
-/* Set the action on getting a CRC error for an ancillary or critical chunk. */
-void PNGAPI
-png_set_crc_action(png_structrp png_ptr, int crit_action, int ancil_action)
-{
- png_debug(1, "in png_set_crc_action");
-
- if (png_ptr == NULL)
- return;
-
- /* Tell libpng how we react to CRC errors in critical chunks */
- switch (crit_action)
- {
- case PNG_CRC_NO_CHANGE: /* Leave setting as is */
- break;
-
- case PNG_CRC_WARN_USE: /* Warn/use data */
- png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK;
- png_ptr->flags |= PNG_FLAG_CRC_CRITICAL_USE;
- break;
-
- case PNG_CRC_QUIET_USE: /* Quiet/use data */
- png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK;
- png_ptr->flags |= PNG_FLAG_CRC_CRITICAL_USE |
- PNG_FLAG_CRC_CRITICAL_IGNORE;
- break;
-
- case PNG_CRC_WARN_DISCARD: /* Not a valid action for critical data */
- png_warning(png_ptr,
- "Can't discard critical data on CRC error");
- case PNG_CRC_ERROR_QUIT: /* Error/quit */
-
- case PNG_CRC_DEFAULT:
- default:
- png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK;
- break;
- }
-
- /* Tell libpng how we react to CRC errors in ancillary chunks */
- switch (ancil_action)
- {
- case PNG_CRC_NO_CHANGE: /* Leave setting as is */
- break;
-
- case PNG_CRC_WARN_USE: /* Warn/use data */
- png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK;
- png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_USE;
- break;
-
- case PNG_CRC_QUIET_USE: /* Quiet/use data */
- png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK;
- png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_USE |
- PNG_FLAG_CRC_ANCILLARY_NOWARN;
- break;
-
- case PNG_CRC_ERROR_QUIT: /* Error/quit */
- png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK;
- png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_NOWARN;
- break;
-
- case PNG_CRC_WARN_DISCARD: /* Warn/discard data */
-
- case PNG_CRC_DEFAULT:
- default:
- png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK;
- break;
- }
-}
-
-#ifdef PNG_READ_TRANSFORMS_SUPPORTED
-/* Is it OK to set a transformation now? Only if png_start_read_image or
- * png_read_update_info have not been called. It is not necessary for the IHDR
- * to have been read in all cases, the parameter allows for this check too.
- */
-static int
-png_rtran_ok(png_structrp png_ptr, int need_IHDR)
-{
- if (png_ptr != NULL)
- {
- if (png_ptr->flags & PNG_FLAG_ROW_INIT)
- png_app_error(png_ptr,
- "invalid after png_start_read_image or png_read_update_info");
-
- else if (need_IHDR && (png_ptr->mode & PNG_HAVE_IHDR) == 0)
- png_app_error(png_ptr, "invalid before the PNG header has been read");
-
- else
- {
- /* Turn on failure to initialize correctly for all transforms. */
- png_ptr->flags |= PNG_FLAG_DETECT_UNINITIALIZED;
-
- return 1; /* Ok */
- }
- }
-
- return 0; /* no png_error possible! */
-}
-#endif
-
-#ifdef PNG_READ_BACKGROUND_SUPPORTED
-/* Handle alpha and tRNS via a background color */
-void PNGFAPI
-png_set_background_fixed(png_structrp png_ptr,
- png_const_color_16p background_color, int background_gamma_code,
- int need_expand, png_fixed_point background_gamma)
-{
- png_debug(1, "in png_set_background_fixed");
-
- if (!png_rtran_ok(png_ptr, 0) || background_color == NULL)
- return;
-
- if (background_gamma_code == PNG_BACKGROUND_GAMMA_UNKNOWN)
- {
- png_warning(png_ptr, "Application must supply a known background gamma");
- return;
- }
-
- png_ptr->transformations |= PNG_COMPOSE | PNG_STRIP_ALPHA;
- png_ptr->transformations &= ~PNG_ENCODE_ALPHA;
- png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA;
-
- png_ptr->background = *background_color;
- png_ptr->background_gamma = background_gamma;
- png_ptr->background_gamma_type = (png_byte)(background_gamma_code);
- if (need_expand)
- png_ptr->transformations |= PNG_BACKGROUND_EXPAND;
- else
- png_ptr->transformations &= ~PNG_BACKGROUND_EXPAND;
-}
-
-# ifdef PNG_FLOATING_POINT_SUPPORTED
-void PNGAPI
-png_set_background(png_structrp png_ptr,
- png_const_color_16p background_color, int background_gamma_code,
- int need_expand, double background_gamma)
-{
- png_set_background_fixed(png_ptr, background_color, background_gamma_code,
- need_expand, png_fixed(png_ptr, background_gamma, "png_set_background"));
-}
-# endif /* FLOATING_POINT */
-#endif /* READ_BACKGROUND */
-
-/* Scale 16-bit depth files to 8-bit depth. If both of these are set then the
- * one that pngrtran does first (scale) happens. This is necessary to allow the
- * TRANSFORM and API behavior to be somewhat consistent, and it's simpler.
- */
-#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
-void PNGAPI
-png_set_scale_16(png_structrp png_ptr)
-{
- png_debug(1, "in png_set_scale_16");
-
- if (!png_rtran_ok(png_ptr, 0))
- return;
-
- png_ptr->transformations |= PNG_SCALE_16_TO_8;
-}
-#endif
-
-#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
-/* Chop 16-bit depth files to 8-bit depth */
-void PNGAPI
-png_set_strip_16(png_structrp png_ptr)
-{
- png_debug(1, "in png_set_strip_16");
-
- if (!png_rtran_ok(png_ptr, 0))
- return;
-
- png_ptr->transformations |= PNG_16_TO_8;
-}
-#endif
-
-#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
-void PNGAPI
-png_set_strip_alpha(png_structrp png_ptr)
-{
- png_debug(1, "in png_set_strip_alpha");
-
- if (!png_rtran_ok(png_ptr, 0))
- return;
-
- png_ptr->transformations |= PNG_STRIP_ALPHA;
-}
-#endif
-
-#if defined(PNG_READ_ALPHA_MODE_SUPPORTED) || defined(PNG_READ_GAMMA_SUPPORTED)
-static png_fixed_point
-translate_gamma_flags(png_structrp png_ptr, png_fixed_point output_gamma,
- int is_screen)
-{
- /* Check for flag values. The main reason for having the old Mac value as a
- * flag is that it is pretty near impossible to work out what the correct
- * value is from Apple documentation - a working Mac system is needed to
- * discover the value!
- */
- if (output_gamma == PNG_DEFAULT_sRGB ||
- output_gamma == PNG_FP_1 / PNG_DEFAULT_sRGB)
- {
- /* If there is no sRGB support this just sets the gamma to the standard
- * sRGB value. (This is a side effect of using this function!)
- */
-# ifdef PNG_READ_sRGB_SUPPORTED
- png_ptr->flags |= PNG_FLAG_ASSUME_sRGB;
-# else
- PNG_UNUSED(png_ptr)
-# endif
- if (is_screen)
- output_gamma = PNG_GAMMA_sRGB;
- else
- output_gamma = PNG_GAMMA_sRGB_INVERSE;
- }
-
- else if (output_gamma == PNG_GAMMA_MAC_18 ||
- output_gamma == PNG_FP_1 / PNG_GAMMA_MAC_18)
- {
- if (is_screen)
- output_gamma = PNG_GAMMA_MAC_OLD;
- else
- output_gamma = PNG_GAMMA_MAC_INVERSE;
- }
-
- return output_gamma;
-}
-
-# ifdef PNG_FLOATING_POINT_SUPPORTED
-static png_fixed_point
-convert_gamma_value(png_structrp png_ptr, double output_gamma)
-{
- /* The following silently ignores cases where fixed point (times 100,000)
- * gamma values are passed to the floating point API. This is safe and it
- * means the fixed point constants work just fine with the floating point
- * API. The alternative would just lead to undetected errors and spurious
- * bug reports. Negative values fail inside the _fixed API unless they
- * correspond to the flag values.
- */
- if (output_gamma > 0 && output_gamma < 128)
- output_gamma *= PNG_FP_1;
-
- /* This preserves -1 and -2 exactly: */
- output_gamma = floor(output_gamma + .5);
-
- if (output_gamma > PNG_FP_MAX || output_gamma < PNG_FP_MIN)
- png_fixed_error(png_ptr, "gamma value");
-
- return (png_fixed_point)output_gamma;
-}
-# endif
-#endif /* READ_ALPHA_MODE || READ_GAMMA */
-
-#ifdef PNG_READ_ALPHA_MODE_SUPPORTED
-void PNGFAPI
-png_set_alpha_mode_fixed(png_structrp png_ptr, int mode,
- png_fixed_point output_gamma)
-{
- int compose = 0;
- png_fixed_point file_gamma;
-
- png_debug(1, "in png_set_alpha_mode");
-
- if (!png_rtran_ok(png_ptr, 0))
- return;
-
- output_gamma = translate_gamma_flags(png_ptr, output_gamma, 1/*screen*/);
-
- /* Validate the value to ensure it is in a reasonable range. The value
- * is expected to be 1 or greater, but this range test allows for some
- * viewing correction values. The intent is to weed out users of this API
- * who use the inverse of the gamma value accidentally! Since some of these
- * values are reasonable this may have to be changed.
- */
- if (output_gamma < 70000 || output_gamma > 300000)
- png_error(png_ptr, "output gamma out of expected range");
-
- /* The default file gamma is the inverse of the output gamma; the output
- * gamma may be changed below so get the file value first:
- */
- file_gamma = png_reciprocal(output_gamma);
-
- /* There are really 8 possibilities here, composed of any combination
- * of:
- *
- * premultiply the color channels
- * do not encode non-opaque pixels
- * encode the alpha as well as the color channels
- *
- * The differences disappear if the input/output ('screen') gamma is 1.0,
- * because then the encoding is a no-op and there is only the choice of
- * premultiplying the color channels or not.
- *
- * png_set_alpha_mode and png_set_background interact because both use
- * png_compose to do the work. Calling both is only useful when
- * png_set_alpha_mode is used to set the default mode - PNG_ALPHA_PNG - along
- * with a default gamma value. Otherwise PNG_COMPOSE must not be set.
- */
- switch (mode)
- {
- case PNG_ALPHA_PNG: /* default: png standard */
- /* No compose, but it may be set by png_set_background! */
- png_ptr->transformations &= ~PNG_ENCODE_ALPHA;
- png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA;
- break;
-
- case PNG_ALPHA_ASSOCIATED: /* color channels premultiplied */
- compose = 1;
- png_ptr->transformations &= ~PNG_ENCODE_ALPHA;
- png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA;
- /* The output is linear: */
- output_gamma = PNG_FP_1;
- break;
-
- case PNG_ALPHA_OPTIMIZED: /* associated, non-opaque pixels linear */
- compose = 1;
- png_ptr->transformations &= ~PNG_ENCODE_ALPHA;
- png_ptr->flags |= PNG_FLAG_OPTIMIZE_ALPHA;
- /* output_gamma records the encoding of opaque pixels! */
- break;
-
- case PNG_ALPHA_BROKEN: /* associated, non-linear, alpha encoded */
- compose = 1;
- png_ptr->transformations |= PNG_ENCODE_ALPHA;
- png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA;
- break;
-
- default:
- png_error(png_ptr, "invalid alpha mode");
- }
-
- /* Only set the default gamma if the file gamma has not been set (this has
- * the side effect that the gamma in a second call to png_set_alpha_mode will
- * be ignored.)
- */
- if (png_ptr->colorspace.gamma == 0)
- {
- png_ptr->colorspace.gamma = file_gamma;
- png_ptr->colorspace.flags |= PNG_COLORSPACE_HAVE_GAMMA;
- }
-
- /* But always set the output gamma: */
- png_ptr->screen_gamma = output_gamma;
-
- /* Finally, if pre-multiplying, set the background fields to achieve the
- * desired result.
- */
- if (compose)
- {
- /* And obtain alpha pre-multiplication by composing on black: */
- memset(&png_ptr->background, 0, (sizeof png_ptr->background));
- png_ptr->background_gamma = png_ptr->colorspace.gamma; /* just in case */
- png_ptr->background_gamma_type = PNG_BACKGROUND_GAMMA_FILE;
- png_ptr->transformations &= ~PNG_BACKGROUND_EXPAND;
-
- if (png_ptr->transformations & PNG_COMPOSE)
- png_error(png_ptr,
- "conflicting calls to set alpha mode and background");
-
- png_ptr->transformations |= PNG_COMPOSE;
- }
-}
-
-# ifdef PNG_FLOATING_POINT_SUPPORTED
-void PNGAPI
-png_set_alpha_mode(png_structrp png_ptr, int mode, double output_gamma)
-{
- png_set_alpha_mode_fixed(png_ptr, mode, convert_gamma_value(png_ptr,
- output_gamma));
-}
-# endif
-#endif
-
-#ifdef PNG_READ_QUANTIZE_SUPPORTED
-/* Dither file to 8-bit. Supply a palette, the current number
- * of elements in the palette, the maximum number of elements
- * allowed, and a histogram if possible. If the current number
- * of colors is greater then the maximum number, the palette will be
- * modified to fit in the maximum number. "full_quantize" indicates
- * whether we need a quantizing cube set up for RGB images, or if we
- * simply are reducing the number of colors in a paletted image.
- */
-
-typedef struct png_dsort_struct
-{
- struct png_dsort_struct * next;
- png_byte left;
- png_byte right;
-} png_dsort;
-typedef png_dsort * png_dsortp;
-typedef png_dsort * * png_dsortpp;
-
-void PNGAPI
-png_set_quantize(png_structrp png_ptr, png_colorp palette,
- int num_palette, int maximum_colors, png_const_uint_16p histogram,
- int full_quantize)
-{
- png_debug(1, "in png_set_quantize");
-
- if (!png_rtran_ok(png_ptr, 0))
- return;
-
- png_ptr->transformations |= PNG_QUANTIZE;
-
- if (!full_quantize)
- {
- int i;
-
- png_ptr->quantize_index = (png_bytep)png_malloc(png_ptr,
- (png_uint_32)(num_palette * (sizeof (png_byte))));
- for (i = 0; i < num_palette; i++)
- png_ptr->quantize_index[i] = (png_byte)i;
- }
-
- if (num_palette > maximum_colors)
- {
- if (histogram != NULL)
- {
- /* This is easy enough, just throw out the least used colors.
- * Perhaps not the best solution, but good enough.
- */
-
- int i;
-
- /* Initialize an array to sort colors */
- png_ptr->quantize_sort = (png_bytep)png_malloc(png_ptr,
- (png_uint_32)(num_palette * (sizeof (png_byte))));
-
- /* Initialize the quantize_sort array */
- for (i = 0; i < num_palette; i++)
- png_ptr->quantize_sort[i] = (png_byte)i;
-
- /* Find the least used palette entries by starting a
- * bubble sort, and running it until we have sorted
- * out enough colors. Note that we don't care about
- * sorting all the colors, just finding which are
- * least used.
- */
-
- for (i = num_palette - 1; i >= maximum_colors; i--)
- {
- int done; /* To stop early if the list is pre-sorted */
- int j;
-
- done = 1;
- for (j = 0; j < i; j++)
- {
- if (histogram[png_ptr->quantize_sort[j]]
- < histogram[png_ptr->quantize_sort[j + 1]])
- {
- png_byte t;
-
- t = png_ptr->quantize_sort[j];
- png_ptr->quantize_sort[j] = png_ptr->quantize_sort[j + 1];
- png_ptr->quantize_sort[j + 1] = t;
- done = 0;
- }
- }
-
- if (done)
- break;
- }
-
- /* Swap the palette around, and set up a table, if necessary */
- if (full_quantize)
- {
- int j = num_palette;
-
- /* Put all the useful colors within the max, but don't
- * move the others.
- */
- for (i = 0; i < maximum_colors; i++)
- {
- if ((int)png_ptr->quantize_sort[i] >= maximum_colors)
- {
- do
- j--;
- while ((int)png_ptr->quantize_sort[j] >= maximum_colors);
-
- palette[i] = palette[j];
- }
- }
- }
- else
- {
- int j = num_palette;
-
- /* Move all the used colors inside the max limit, and
- * develop a translation table.
- */
- for (i = 0; i < maximum_colors; i++)
- {
- /* Only move the colors we need to */
- if ((int)png_ptr->quantize_sort[i] >= maximum_colors)
- {
- png_color tmp_color;
-
- do
- j--;
- while ((int)png_ptr->quantize_sort[j] >= maximum_colors);
-
- tmp_color = palette[j];
- palette[j] = palette[i];
- palette[i] = tmp_color;
- /* Indicate where the color went */
- png_ptr->quantize_index[j] = (png_byte)i;
- png_ptr->quantize_index[i] = (png_byte)j;
- }
- }
-
- /* Find closest color for those colors we are not using */
- for (i = 0; i < num_palette; i++)
- {
- if ((int)png_ptr->quantize_index[i] >= maximum_colors)
- {
- int min_d, k, min_k, d_index;
-
- /* Find the closest color to one we threw out */
- d_index = png_ptr->quantize_index[i];
- min_d = PNG_COLOR_DIST(palette[d_index], palette[0]);
- for (k = 1, min_k = 0; k < maximum_colors; k++)
- {
- int d;
-
- d = PNG_COLOR_DIST(palette[d_index], palette[k]);
-
- if (d < min_d)
- {
- min_d = d;
- min_k = k;
- }
- }
- /* Point to closest color */
- png_ptr->quantize_index[i] = (png_byte)min_k;
- }
- }
- }
- png_free(png_ptr, png_ptr->quantize_sort);
- png_ptr->quantize_sort = NULL;
- }
- else
- {
- /* This is much harder to do simply (and quickly). Perhaps
- * we need to go through a median cut routine, but those
- * don't always behave themselves with only a few colors
- * as input. So we will just find the closest two colors,
- * and throw out one of them (chosen somewhat randomly).
- * [We don't understand this at all, so if someone wants to
- * work on improving it, be our guest - AED, GRP]
- */
- int i;
- int max_d;
- int num_new_palette;
- png_dsortp t;
- png_dsortpp hash;
-
- t = NULL;
-
- /* Initialize palette index arrays */
- png_ptr->index_to_palette = (png_bytep)png_malloc(png_ptr,
- (png_uint_32)(num_palette * (sizeof (png_byte))));
- png_ptr->palette_to_index = (png_bytep)png_malloc(png_ptr,
- (png_uint_32)(num_palette * (sizeof (png_byte))));
-
- /* Initialize the sort array */
- for (i = 0; i < num_palette; i++)
- {
- png_ptr->index_to_palette[i] = (png_byte)i;
- png_ptr->palette_to_index[i] = (png_byte)i;
- }
-
- hash = (png_dsortpp)png_calloc(png_ptr, (png_uint_32)(769 *
- (sizeof (png_dsortp))));
-
- num_new_palette = num_palette;
-
- /* Initial wild guess at how far apart the farthest pixel
- * pair we will be eliminating will be. Larger
- * numbers mean more areas will be allocated, Smaller
- * numbers run the risk of not saving enough data, and
- * having to do this all over again.
- *
- * I have not done extensive checking on this number.
- */
- max_d = 96;
-
- while (num_new_palette > maximum_colors)
- {
- for (i = 0; i < num_new_palette - 1; i++)
- {
- int j;
-
- for (j = i + 1; j < num_new_palette; j++)
- {
- int d;
-
- d = PNG_COLOR_DIST(palette[i], palette[j]);
-
- if (d <= max_d)
- {
-
- t = (png_dsortp)png_malloc_warn(png_ptr,
- (png_uint_32)(sizeof (png_dsort)));
-
- if (t == NULL)
- break;
-
- t->next = hash[d];
- t->left = (png_byte)i;
- t->right = (png_byte)j;
- hash[d] = t;
- }
- }
- if (t == NULL)
- break;
- }
-
- if (t != NULL)
- for (i = 0; i <= max_d; i++)
- {
- if (hash[i] != NULL)
- {
- png_dsortp p;
-
- for (p = hash[i]; p; p = p->next)
- {
- if ((int)png_ptr->index_to_palette[p->left]
- < num_new_palette &&
- (int)png_ptr->index_to_palette[p->right]
- < num_new_palette)
- {
- int j, next_j;
-
- if (num_new_palette & 0x01)
- {
- j = p->left;
- next_j = p->right;
- }
- else
- {
- j = p->right;
- next_j = p->left;
- }
-
- num_new_palette--;
- palette[png_ptr->index_to_palette[j]]
- = palette[num_new_palette];
- if (!full_quantize)
- {
- int k;
-
- for (k = 0; k < num_palette; k++)
- {
- if (png_ptr->quantize_index[k] ==
- png_ptr->index_to_palette[j])
- png_ptr->quantize_index[k] =
- png_ptr->index_to_palette[next_j];
-
- if ((int)png_ptr->quantize_index[k] ==
- num_new_palette)
- png_ptr->quantize_index[k] =
- png_ptr->index_to_palette[j];
- }
- }
-
- png_ptr->index_to_palette[png_ptr->palette_to_index
- [num_new_palette]] = png_ptr->index_to_palette[j];
-
- png_ptr->palette_to_index[png_ptr->index_to_palette[j]]
- = png_ptr->palette_to_index[num_new_palette];
-
- png_ptr->index_to_palette[j] =
- (png_byte)num_new_palette;
-
- png_ptr->palette_to_index[num_new_palette] =
- (png_byte)j;
- }
- if (num_new_palette <= maximum_colors)
- break;
- }
- if (num_new_palette <= maximum_colors)
- break;
- }
- }
-
- for (i = 0; i < 769; i++)
- {
- if (hash[i] != NULL)
- {
- png_dsortp p = hash[i];
- while (p)
- {
- t = p->next;
- png_free(png_ptr, p);
- p = t;
- }
- }
- hash[i] = 0;
- }
- max_d += 96;
- }
- png_free(png_ptr, hash);
- png_free(png_ptr, png_ptr->palette_to_index);
- png_free(png_ptr, png_ptr->index_to_palette);
- png_ptr->palette_to_index = NULL;
- png_ptr->index_to_palette = NULL;
- }
- num_palette = maximum_colors;
- }
- if (png_ptr->palette == NULL)
- {
- png_ptr->palette = palette;
- }
- png_ptr->num_palette = (png_uint_16)num_palette;
-
- if (full_quantize)
- {
- int i;
- png_bytep distance;
- int total_bits = PNG_QUANTIZE_RED_BITS + PNG_QUANTIZE_GREEN_BITS +
- PNG_QUANTIZE_BLUE_BITS;
- int num_red = (1 << PNG_QUANTIZE_RED_BITS);
- int num_green = (1 << PNG_QUANTIZE_GREEN_BITS);
- int num_blue = (1 << PNG_QUANTIZE_BLUE_BITS);
- png_size_t num_entries = ((png_size_t)1 << total_bits);
-
- png_ptr->palette_lookup = (png_bytep)png_calloc(png_ptr,
- (png_uint_32)(num_entries * (sizeof (png_byte))));
-
- distance = (png_bytep)png_malloc(png_ptr, (png_uint_32)(num_entries *
- (sizeof (png_byte))));
-
- memset(distance, 0xff, num_entries * (sizeof (png_byte)));
-
- for (i = 0; i < num_palette; i++)
- {
- int ir, ig, ib;
- int r = (palette[i].red >> (8 - PNG_QUANTIZE_RED_BITS));
- int g = (palette[i].green >> (8 - PNG_QUANTIZE_GREEN_BITS));
- int b = (palette[i].blue >> (8 - PNG_QUANTIZE_BLUE_BITS));
-
- for (ir = 0; ir < num_red; ir++)
- {
- /* int dr = abs(ir - r); */
- int dr = ((ir > r) ? ir - r : r - ir);
- int index_r = (ir << (PNG_QUANTIZE_BLUE_BITS +
- PNG_QUANTIZE_GREEN_BITS));
-
- for (ig = 0; ig < num_green; ig++)
- {
- /* int dg = abs(ig - g); */
- int dg = ((ig > g) ? ig - g : g - ig);
- int dt = dr + dg;
- int dm = ((dr > dg) ? dr : dg);
- int index_g = index_r | (ig << PNG_QUANTIZE_BLUE_BITS);
-
- for (ib = 0; ib < num_blue; ib++)
- {
- int d_index = index_g | ib;
- /* int db = abs(ib - b); */
- int db = ((ib > b) ? ib - b : b - ib);
- int dmax = ((dm > db) ? dm : db);
- int d = dmax + dt + db;
-
- if (d < (int)distance[d_index])
- {
- distance[d_index] = (png_byte)d;
- png_ptr->palette_lookup[d_index] = (png_byte)i;
- }
- }
- }
- }
- }
-
- png_free(png_ptr, distance);
- }
-}
-#endif /* PNG_READ_QUANTIZE_SUPPORTED */
-
-#ifdef PNG_READ_GAMMA_SUPPORTED
-void PNGFAPI
-png_set_gamma_fixed(png_structrp png_ptr, png_fixed_point scrn_gamma,
- png_fixed_point file_gamma)
-{
- png_debug(1, "in png_set_gamma_fixed");
-
- if (!png_rtran_ok(png_ptr, 0))
- return;
-
- /* New in libpng-1.5.4 - reserve particular negative values as flags. */
- scrn_gamma = translate_gamma_flags(png_ptr, scrn_gamma, 1/*screen*/);
- file_gamma = translate_gamma_flags(png_ptr, file_gamma, 0/*file*/);
-
- /* Checking the gamma values for being >0 was added in 1.5.4 along with the
- * premultiplied alpha support; this actually hides an undocumented feature
- * of the previous implementation which allowed gamma processing to be
- * disabled in background handling. There is no evidence (so far) that this
- * was being used; however, png_set_background itself accepted and must still
- * accept '0' for the gamma value it takes, because it isn't always used.
- *
- * Since this is an API change (albeit a very minor one that removes an
- * undocumented API feature) the following checks were only enabled in
- * libpng-1.6.0.
- */
- if (file_gamma <= 0)
- png_error(png_ptr, "invalid file gamma in png_set_gamma");
-
- if (scrn_gamma <= 0)
- png_error(png_ptr, "invalid screen gamma in png_set_gamma");
-
- /* Set the gamma values unconditionally - this overrides the value in the PNG
- * file if a gAMA chunk was present. png_set_alpha_mode provides a
- * different, easier, way to default the file gamma.
- */
- png_ptr->colorspace.gamma = file_gamma;
- png_ptr->colorspace.flags |= PNG_COLORSPACE_HAVE_GAMMA;
- png_ptr->screen_gamma = scrn_gamma;
-}
-
-# ifdef PNG_FLOATING_POINT_SUPPORTED
-void PNGAPI
-png_set_gamma(png_structrp png_ptr, double scrn_gamma, double file_gamma)
-{
- png_set_gamma_fixed(png_ptr, convert_gamma_value(png_ptr, scrn_gamma),
- convert_gamma_value(png_ptr, file_gamma));
-}
-# endif /* FLOATING_POINT_SUPPORTED */
-#endif /* READ_GAMMA */
-
-#ifdef PNG_READ_EXPAND_SUPPORTED
-/* Expand paletted images to RGB, expand grayscale images of
- * less than 8-bit depth to 8-bit depth, and expand tRNS chunks
- * to alpha channels.
- */
-void PNGAPI
-png_set_expand(png_structrp png_ptr)
-{
- png_debug(1, "in png_set_expand");
-
- if (!png_rtran_ok(png_ptr, 0))
- return;
-
- png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS);
-}
-
-/* GRR 19990627: the following three functions currently are identical
- * to png_set_expand(). However, it is entirely reasonable that someone
- * might wish to expand an indexed image to RGB but *not* expand a single,
- * fully transparent palette entry to a full alpha channel--perhaps instead
- * convert tRNS to the grayscale/RGB format (16-bit RGB value), or replace
- * the transparent color with a particular RGB value, or drop tRNS entirely.
- * IOW, a future version of the library may make the transformations flag
- * a bit more fine-grained, with separate bits for each of these three
- * functions.
- *
- * More to the point, these functions make it obvious what libpng will be
- * doing, whereas "expand" can (and does) mean any number of things.
- *
- * GRP 20060307: In libpng-1.2.9, png_set_gray_1_2_4_to_8() was modified
- * to expand only the sample depth but not to expand the tRNS to alpha
- * and its name was changed to png_set_expand_gray_1_2_4_to_8().
- */
-
-/* Expand paletted images to RGB. */
-void PNGAPI
-png_set_palette_to_rgb(png_structrp png_ptr)
-{
- png_debug(1, "in png_set_palette_to_rgb");
-
- if (!png_rtran_ok(png_ptr, 0))
- return;
-
- png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS);
-}
-
-/* Expand grayscale images of less than 8-bit depth to 8 bits. */
-void PNGAPI
-png_set_expand_gray_1_2_4_to_8(png_structrp png_ptr)
-{
- png_debug(1, "in png_set_expand_gray_1_2_4_to_8");
-
- if (!png_rtran_ok(png_ptr, 0))
- return;
-
- png_ptr->transformations |= PNG_EXPAND;
-}
-
-/* Expand tRNS chunks to alpha channels. */
-void PNGAPI
-png_set_tRNS_to_alpha(png_structrp png_ptr)
-{
- png_debug(1, "in png_set_tRNS_to_alpha");
-
- if (!png_rtran_ok(png_ptr, 0))
- return;
-
- png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS);
-}
-#endif /* defined(PNG_READ_EXPAND_SUPPORTED) */
-
-#ifdef PNG_READ_EXPAND_16_SUPPORTED
-/* Expand to 16-bit channels, expand the tRNS chunk too (because otherwise
- * it may not work correctly.)
- */
-void PNGAPI
-png_set_expand_16(png_structrp png_ptr)
-{
- png_debug(1, "in png_set_expand_16");
-
- if (!png_rtran_ok(png_ptr, 0))
- return;
-
- png_ptr->transformations |= (PNG_EXPAND_16 | PNG_EXPAND | PNG_EXPAND_tRNS);
-}
-#endif
-
-#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
-void PNGAPI
-png_set_gray_to_rgb(png_structrp png_ptr)
-{
- png_debug(1, "in png_set_gray_to_rgb");
-
- if (!png_rtran_ok(png_ptr, 0))
- return;
-
- /* Because rgb must be 8 bits or more: */
- png_set_expand_gray_1_2_4_to_8(png_ptr);
- png_ptr->transformations |= PNG_GRAY_TO_RGB;
-}
-#endif
-
-#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
-void PNGFAPI
-png_set_rgb_to_gray_fixed(png_structrp png_ptr, int error_action,
- png_fixed_point red, png_fixed_point green)
-{
- png_debug(1, "in png_set_rgb_to_gray");
-
- /* Need the IHDR here because of the check on color_type below. */
- /* TODO: fix this */
- if (!png_rtran_ok(png_ptr, 1))
- return;
-
- switch(error_action)
- {
- case PNG_ERROR_ACTION_NONE:
- png_ptr->transformations |= PNG_RGB_TO_GRAY;
- break;
-
- case PNG_ERROR_ACTION_WARN:
- png_ptr->transformations |= PNG_RGB_TO_GRAY_WARN;
- break;
-
- case PNG_ERROR_ACTION_ERROR:
- png_ptr->transformations |= PNG_RGB_TO_GRAY_ERR;
- break;
-
- default:
- png_error(png_ptr, "invalid error action to rgb_to_gray");
- break;
- }
-
- if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
-#ifdef PNG_READ_EXPAND_SUPPORTED
- png_ptr->transformations |= PNG_EXPAND;
-#else
- {
- /* Make this an error in 1.6 because otherwise the application may assume
- * that it just worked and get a memory overwrite.
- */
- png_error(png_ptr,
- "Cannot do RGB_TO_GRAY without EXPAND_SUPPORTED");
-
- /* png_ptr->transformations &= ~PNG_RGB_TO_GRAY; */
- }
-#endif
- {
- if (red >= 0 && green >= 0 && red + green <= PNG_FP_1)
- {
- png_uint_16 red_int, green_int;
-
- /* NOTE: this calculation does not round, but this behavior is retained
- * for consistency, the inaccuracy is very small. The code here always
- * overwrites the coefficients, regardless of whether they have been
- * defaulted or set already.
- */
- red_int = (png_uint_16)(((png_uint_32)red*32768)/100000);
- green_int = (png_uint_16)(((png_uint_32)green*32768)/100000);
-
- png_ptr->rgb_to_gray_red_coeff = red_int;
- png_ptr->rgb_to_gray_green_coeff = green_int;
- png_ptr->rgb_to_gray_coefficients_set = 1;
- }
-
- else
- {
- if (red >= 0 && green >= 0)
- png_app_warning(png_ptr,
- "ignoring out of range rgb_to_gray coefficients");
-
- /* Use the defaults, from the cHRM chunk if set, else the historical
- * values which are close to the sRGB/HDTV/ITU-Rec 709 values. See
- * png_do_rgb_to_gray for more discussion of the values. In this case
- * the coefficients are not marked as 'set' and are not overwritten if
- * something has already provided a default.
- */
- if (png_ptr->rgb_to_gray_red_coeff == 0 &&
- png_ptr->rgb_to_gray_green_coeff == 0)
- {
- png_ptr->rgb_to_gray_red_coeff = 6968;
- png_ptr->rgb_to_gray_green_coeff = 23434;
- /* png_ptr->rgb_to_gray_blue_coeff = 2366; */
- }
- }
- }
-}
-
-#ifdef PNG_FLOATING_POINT_SUPPORTED
-/* Convert a RGB image to a grayscale of the same width. This allows us,
- * for example, to convert a 24 bpp RGB image into an 8 bpp grayscale image.
- */
-
-void PNGAPI
-png_set_rgb_to_gray(png_structrp png_ptr, int error_action, double red,
- double green)
-{
- png_set_rgb_to_gray_fixed(png_ptr, error_action,
- png_fixed(png_ptr, red, "rgb to gray red coefficient"),
- png_fixed(png_ptr, green, "rgb to gray green coefficient"));
-}
-#endif /* FLOATING POINT */
-
-#endif /* RGB_TO_GRAY */
-
-#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
- defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
-void PNGAPI
-png_set_read_user_transform_fn(png_structrp png_ptr, png_user_transform_ptr
- read_user_transform_fn)
-{
- png_debug(1, "in png_set_read_user_transform_fn");
-
-#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
- png_ptr->transformations |= PNG_USER_TRANSFORM;
- png_ptr->read_user_transform_fn = read_user_transform_fn;
-#endif
-}
-#endif
-
-#ifdef PNG_READ_TRANSFORMS_SUPPORTED
-#ifdef PNG_READ_GAMMA_SUPPORTED
-/* In the case of gamma transformations only do transformations on images where
- * the [file] gamma and screen_gamma are not close reciprocals, otherwise it
- * slows things down slightly, and also needlessly introduces small errors.
- */
-static int /* PRIVATE */
-png_gamma_threshold(png_fixed_point screen_gamma, png_fixed_point file_gamma)
-{
- /* PNG_GAMMA_THRESHOLD is the threshold for performing gamma
- * correction as a difference of the overall transform from 1.0
- *
- * We want to compare the threshold with s*f - 1, if we get
- * overflow here it is because of wacky gamma values so we
- * turn on processing anyway.
- */
- png_fixed_point gtest;
- return !png_muldiv(>est, screen_gamma, file_gamma, PNG_FP_1) ||
- png_gamma_significant(gtest);
-}
-#endif
-
-/* Initialize everything needed for the read. This includes modifying
- * the palette.
- */
-
-/*For the moment 'png_init_palette_transformations' and
- * 'png_init_rgb_transformations' only do some flag canceling optimizations.
- * The intent is that these two routines should have palette or rgb operations
- * extracted from 'png_init_read_transformations'.
- */
-static void /* PRIVATE */
-png_init_palette_transformations(png_structrp png_ptr)
-{
- /* Called to handle the (input) palette case. In png_do_read_transformations
- * the first step is to expand the palette if requested, so this code must
- * take care to only make changes that are invariant with respect to the
- * palette expansion, or only do them if there is no expansion.
- *
- * STRIP_ALPHA has already been handled in the caller (by setting num_trans
- * to 0.)
- */
- int input_has_alpha = 0;
- int input_has_transparency = 0;
-
- if (png_ptr->num_trans > 0)
- {
- int i;
-
- /* Ignore if all the entries are opaque (unlikely!) */
- for (i=0; i<png_ptr->num_trans; ++i)
- if (png_ptr->trans_alpha[i] == 255)
- continue;
- else if (png_ptr->trans_alpha[i] == 0)
- input_has_transparency = 1;
- else
- input_has_alpha = 1;
- }
-
- /* If no alpha we can optimize. */
- if (!input_has_alpha)
- {
- /* Any alpha means background and associative alpha processing is
- * required, however if the alpha is 0 or 1 throughout OPTIIMIZE_ALPHA
- * and ENCODE_ALPHA are irrelevant.
- */
- png_ptr->transformations &= ~PNG_ENCODE_ALPHA;
- png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA;
-
- if (!input_has_transparency)
- png_ptr->transformations &= ~(PNG_COMPOSE | PNG_BACKGROUND_EXPAND);
- }
-
-#if defined(PNG_READ_EXPAND_SUPPORTED) && defined(PNG_READ_BACKGROUND_SUPPORTED)
- /* png_set_background handling - deals with the complexity of whether the
- * background color is in the file format or the screen format in the case
- * where an 'expand' will happen.
- */
-
- /* The following code cannot be entered in the alpha pre-multiplication case
- * because PNG_BACKGROUND_EXPAND is cancelled below.
- */
- if ((png_ptr->transformations & PNG_BACKGROUND_EXPAND) &&
- (png_ptr->transformations & PNG_EXPAND))
- {
- {
- png_ptr->background.red =
- png_ptr->palette[png_ptr->background.index].red;
- png_ptr->background.green =
- png_ptr->palette[png_ptr->background.index].green;
- png_ptr->background.blue =
- png_ptr->palette[png_ptr->background.index].blue;
-
-#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED
- if (png_ptr->transformations & PNG_INVERT_ALPHA)
- {
- if (!(png_ptr->transformations & PNG_EXPAND_tRNS))
- {
- /* Invert the alpha channel (in tRNS) unless the pixels are
- * going to be expanded, in which case leave it for later
- */
- int i, istop = png_ptr->num_trans;
-
- for (i=0; i<istop; i++)
- png_ptr->trans_alpha[i] = (png_byte)(255 -
- png_ptr->trans_alpha[i]);
- }
- }
-#endif /* PNG_READ_INVERT_ALPHA_SUPPORTED */
- }
- } /* background expand and (therefore) no alpha association. */
-#endif /* PNG_READ_EXPAND_SUPPORTED && PNG_READ_BACKGROUND_SUPPORTED */
-}
-
-static void /* PRIVATE */
-png_init_rgb_transformations(png_structrp png_ptr)
-{
- /* Added to libpng-1.5.4: check the color type to determine whether there
- * is any alpha or transparency in the image and simply cancel the
- * background and alpha mode stuff if there isn't.
- */
- int input_has_alpha = (png_ptr->color_type & PNG_COLOR_MASK_ALPHA) != 0;
- int input_has_transparency = png_ptr->num_trans > 0;
-
- /* If no alpha we can optimize. */
- if (!input_has_alpha)
- {
- /* Any alpha means background and associative alpha processing is
- * required, however if the alpha is 0 or 1 throughout OPTIIMIZE_ALPHA
- * and ENCODE_ALPHA are irrelevant.
- */
-# ifdef PNG_READ_ALPHA_MODE_SUPPORTED
- png_ptr->transformations &= ~PNG_ENCODE_ALPHA;
- png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA;
-# endif
-
- if (!input_has_transparency)
- png_ptr->transformations &= ~(PNG_COMPOSE | PNG_BACKGROUND_EXPAND);
- }
-
-#if defined(PNG_READ_EXPAND_SUPPORTED) && defined(PNG_READ_BACKGROUND_SUPPORTED)
- /* png_set_background handling - deals with the complexity of whether the
- * background color is in the file format or the screen format in the case
- * where an 'expand' will happen.
- */
-
- /* The following code cannot be entered in the alpha pre-multiplication case
- * because PNG_BACKGROUND_EXPAND is cancelled below.
- */
- if ((png_ptr->transformations & PNG_BACKGROUND_EXPAND) &&
- (png_ptr->transformations & PNG_EXPAND) &&
- !(png_ptr->color_type & PNG_COLOR_MASK_COLOR))
- /* i.e., GRAY or GRAY_ALPHA */
- {
- {
- /* Expand background and tRNS chunks */
- int gray = png_ptr->background.gray;
- int trans_gray = png_ptr->trans_color.gray;
-
- switch (png_ptr->bit_depth)
- {
- case 1:
- gray *= 0xff;
- trans_gray *= 0xff;
- break;
-
- case 2:
- gray *= 0x55;
- trans_gray *= 0x55;
- break;
-
- case 4:
- gray *= 0x11;
- trans_gray *= 0x11;
- break;
-
- default:
-
- case 8:
- /* FALL THROUGH (Already 8 bits) */
-
- case 16:
- /* Already a full 16 bits */
- break;
- }
-
- png_ptr->background.red = png_ptr->background.green =
- png_ptr->background.blue = (png_uint_16)gray;
-
- if (!(png_ptr->transformations & PNG_EXPAND_tRNS))
- {
- png_ptr->trans_color.red = png_ptr->trans_color.green =
- png_ptr->trans_color.blue = (png_uint_16)trans_gray;
- }
- }
- } /* background expand and (therefore) no alpha association. */
-#endif /* PNG_READ_EXPAND_SUPPORTED && PNG_READ_BACKGROUND_SUPPORTED */
-}
-
-void /* PRIVATE */
-png_init_read_transformations(png_structrp png_ptr)
-{
- png_debug(1, "in png_init_read_transformations");
-
- /* This internal function is called from png_read_start_row in pngrutil.c
- * and it is called before the 'rowbytes' calculation is done, so the code
- * in here can change or update the transformations flags.
- *
- * First do updates that do not depend on the details of the PNG image data
- * being processed.
- */
-
-#ifdef PNG_READ_GAMMA_SUPPORTED
- /* Prior to 1.5.4 these tests were performed from png_set_gamma, 1.5.4 adds
- * png_set_alpha_mode and this is another source for a default file gamma so
- * the test needs to be performed later - here. In addition prior to 1.5.4
- * the tests were repeated for the PALETTE color type here - this is no
- * longer necessary (and doesn't seem to have been necessary before.)
- */
- {
- /* The following temporary indicates if overall gamma correction is
- * required.
- */
- int gamma_correction = 0;
-
- if (png_ptr->colorspace.gamma != 0) /* has been set */
- {
- if (png_ptr->screen_gamma != 0) /* screen set too */
- gamma_correction = png_gamma_threshold(png_ptr->colorspace.gamma,
- png_ptr->screen_gamma);
-
- else
- /* Assume the output matches the input; a long time default behavior
- * of libpng, although the standard has nothing to say about this.
- */
- png_ptr->screen_gamma = png_reciprocal(png_ptr->colorspace.gamma);
- }
-
- else if (png_ptr->screen_gamma != 0)
- /* The converse - assume the file matches the screen, note that this
- * perhaps undesireable default can (from 1.5.4) be changed by calling
- * png_set_alpha_mode (even if the alpha handling mode isn't required
- * or isn't changed from the default.)
- */
- png_ptr->colorspace.gamma = png_reciprocal(png_ptr->screen_gamma);
-
- else /* neither are set */
- /* Just in case the following prevents any processing - file and screen
- * are both assumed to be linear and there is no way to introduce a
- * third gamma value other than png_set_background with 'UNIQUE', and,
- * prior to 1.5.4
- */
- png_ptr->screen_gamma = png_ptr->colorspace.gamma = PNG_FP_1;
-
- /* We have a gamma value now. */
- png_ptr->colorspace.flags |= PNG_COLORSPACE_HAVE_GAMMA;
-
- /* Now turn the gamma transformation on or off as appropriate. Notice
- * that PNG_GAMMA just refers to the file->screen correction. Alpha
- * composition may independently cause gamma correction because it needs
- * linear data (e.g. if the file has a gAMA chunk but the screen gamma
- * hasn't been specified.) In any case this flag may get turned off in
- * the code immediately below if the transform can be handled outside the
- * row loop.
- */
- if (gamma_correction)
- png_ptr->transformations |= PNG_GAMMA;
-
- else
- png_ptr->transformations &= ~PNG_GAMMA;
- }
-#endif
-
- /* Certain transformations have the effect of preventing other
- * transformations that happen afterward in png_do_read_transformations,
- * resolve the interdependencies here. From the code of
- * png_do_read_transformations the order is:
- *
- * 1) PNG_EXPAND (including PNG_EXPAND_tRNS)
- * 2) PNG_STRIP_ALPHA (if no compose)
- * 3) PNG_RGB_TO_GRAY
- * 4) PNG_GRAY_TO_RGB iff !PNG_BACKGROUND_IS_GRAY
- * 5) PNG_COMPOSE
- * 6) PNG_GAMMA
- * 7) PNG_STRIP_ALPHA (if compose)
- * 8) PNG_ENCODE_ALPHA
- * 9) PNG_SCALE_16_TO_8
- * 10) PNG_16_TO_8
- * 11) PNG_QUANTIZE (converts to palette)
- * 12) PNG_EXPAND_16
- * 13) PNG_GRAY_TO_RGB iff PNG_BACKGROUND_IS_GRAY
- * 14) PNG_INVERT_MONO
- * 15) PNG_SHIFT
- * 16) PNG_PACK
- * 17) PNG_BGR
- * 18) PNG_PACKSWAP
- * 19) PNG_FILLER (includes PNG_ADD_ALPHA)
- * 20) PNG_INVERT_ALPHA
- * 21) PNG_SWAP_ALPHA
- * 22) PNG_SWAP_BYTES
- * 23) PNG_USER_TRANSFORM [must be last]
- */
-#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
- if ((png_ptr->transformations & PNG_STRIP_ALPHA) &&
- !(png_ptr->transformations & PNG_COMPOSE))
- {
- /* Stripping the alpha channel happens immediately after the 'expand'
- * transformations, before all other transformation, so it cancels out
- * the alpha handling. It has the side effect negating the effect of
- * PNG_EXPAND_tRNS too:
- */
- png_ptr->transformations &= ~(PNG_BACKGROUND_EXPAND | PNG_ENCODE_ALPHA |
- PNG_EXPAND_tRNS);
- png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA;
-
- /* Kill the tRNS chunk itself too. Prior to 1.5.4 this did not happen
- * so transparency information would remain just so long as it wasn't
- * expanded. This produces unexpected API changes if the set of things
- * that do PNG_EXPAND_tRNS changes (perfectly possible given the
- * documentation - which says ask for what you want, accept what you
- * get.) This makes the behavior consistent from 1.5.4:
- */
- png_ptr->num_trans = 0;
- }
-#endif /* STRIP_ALPHA supported, no COMPOSE */
-
-#ifdef PNG_READ_ALPHA_MODE_SUPPORTED
- /* If the screen gamma is about 1.0 then the OPTIMIZE_ALPHA and ENCODE_ALPHA
- * settings will have no effect.
- */
- if (!png_gamma_significant(png_ptr->screen_gamma))
- {
- png_ptr->transformations &= ~PNG_ENCODE_ALPHA;
- png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA;
- }
-#endif
-
-#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
- /* Make sure the coefficients for the rgb to gray conversion are set
- * appropriately.
- */
- if (png_ptr->transformations & PNG_RGB_TO_GRAY)
- png_colorspace_set_rgb_coefficients(png_ptr);
-#endif
-
-#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
-#if defined(PNG_READ_EXPAND_SUPPORTED) && defined(PNG_READ_BACKGROUND_SUPPORTED)
- /* Detect gray background and attempt to enable optimization for
- * gray --> RGB case.
- *
- * Note: if PNG_BACKGROUND_EXPAND is set and color_type is either RGB or
- * RGB_ALPHA (in which case need_expand is superfluous anyway), the
- * background color might actually be gray yet not be flagged as such.
- * This is not a problem for the current code, which uses
- * PNG_BACKGROUND_IS_GRAY only to decide when to do the
- * png_do_gray_to_rgb() transformation.
- *
- * TODO: this code needs to be revised to avoid the complexity and
- * interdependencies. The color type of the background should be recorded in
- * png_set_background, along with the bit depth, then the code has a record
- * of exactly what color space the background is currently in.
- */
- if (png_ptr->transformations & PNG_BACKGROUND_EXPAND)
- {
- /* PNG_BACKGROUND_EXPAND: the background is in the file color space, so if
- * the file was grayscale the background value is gray.
- */
- if (!(png_ptr->color_type & PNG_COLOR_MASK_COLOR))
- png_ptr->mode |= PNG_BACKGROUND_IS_GRAY;
- }
-
- else if (png_ptr->transformations & PNG_COMPOSE)
- {
- /* PNG_COMPOSE: png_set_background was called with need_expand false,
- * so the color is in the color space of the output or png_set_alpha_mode
- * was called and the color is black. Ignore RGB_TO_GRAY because that
- * happens before GRAY_TO_RGB.
- */
- if (png_ptr->transformations & PNG_GRAY_TO_RGB)
- {
- if (png_ptr->background.red == png_ptr->background.green &&
- png_ptr->background.red == png_ptr->background.blue)
- {
- png_ptr->mode |= PNG_BACKGROUND_IS_GRAY;
- png_ptr->background.gray = png_ptr->background.red;
- }
- }
- }
-#endif /* PNG_READ_EXPAND_SUPPORTED && PNG_READ_BACKGROUND_SUPPORTED */
-#endif /* PNG_READ_GRAY_TO_RGB_SUPPORTED */
-
- /* For indexed PNG data (PNG_COLOR_TYPE_PALETTE) many of the transformations
- * can be performed directly on the palette, and some (such as rgb to gray)
- * can be optimized inside the palette. This is particularly true of the
- * composite (background and alpha) stuff, which can be pretty much all done
- * in the palette even if the result is expanded to RGB or gray afterward.
- *
- * NOTE: this is Not Yet Implemented, the code behaves as in 1.5.1 and
- * earlier and the palette stuff is actually handled on the first row. This
- * leads to the reported bug that the palette returned by png_get_PLTE is not
- * updated.
- */
- if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
- png_init_palette_transformations(png_ptr);
-
- else
- png_init_rgb_transformations(png_ptr);
-
-#if defined(PNG_READ_BACKGROUND_SUPPORTED) && \
- defined(PNG_READ_EXPAND_16_SUPPORTED)
- if ((png_ptr->transformations & PNG_EXPAND_16) &&
- (png_ptr->transformations & PNG_COMPOSE) &&
- !(png_ptr->transformations & PNG_BACKGROUND_EXPAND) &&
- png_ptr->bit_depth != 16)
- {
- /* TODO: fix this. Because the expand_16 operation is after the compose
- * handling the background color must be 8, not 16, bits deep, but the
- * application will supply a 16-bit value so reduce it here.
- *
- * The PNG_BACKGROUND_EXPAND code above does not expand to 16 bits at
- * present, so that case is ok (until do_expand_16 is moved.)
- *
- * NOTE: this discards the low 16 bits of the user supplied background
- * color, but until expand_16 works properly there is no choice!
- */
-# define CHOP(x) (x)=((png_uint_16)PNG_DIV257(x))
- CHOP(png_ptr->background.red);
- CHOP(png_ptr->background.green);
- CHOP(png_ptr->background.blue);
- CHOP(png_ptr->background.gray);
-# undef CHOP
- }
-#endif /* PNG_READ_BACKGROUND_SUPPORTED && PNG_READ_EXPAND_16_SUPPORTED */
-
-#if defined(PNG_READ_BACKGROUND_SUPPORTED) && \
- (defined(PNG_READ_SCALE_16_TO_8_SUPPORTED) || \
- defined(PNG_READ_STRIP_16_TO_8_SUPPORTED))
- if ((png_ptr->transformations & (PNG_16_TO_8|PNG_SCALE_16_TO_8)) &&
- (png_ptr->transformations & PNG_COMPOSE) &&
- !(png_ptr->transformations & PNG_BACKGROUND_EXPAND) &&
- png_ptr->bit_depth == 16)
- {
- /* On the other hand, if a 16-bit file is to be reduced to 8-bits per
- * component this will also happen after PNG_COMPOSE and so the background
- * color must be pre-expanded here.
- *
- * TODO: fix this too.
- */
- png_ptr->background.red = (png_uint_16)(png_ptr->background.red * 257);
- png_ptr->background.green =
- (png_uint_16)(png_ptr->background.green * 257);
- png_ptr->background.blue = (png_uint_16)(png_ptr->background.blue * 257);
- png_ptr->background.gray = (png_uint_16)(png_ptr->background.gray * 257);
- }
-#endif
-
- /* NOTE: below 'PNG_READ_ALPHA_MODE_SUPPORTED' is presumed to also enable the
- * background support (see the comments in scripts/pnglibconf.dfa), this
- * allows pre-multiplication of the alpha channel to be implemented as
- * compositing on black. This is probably sub-optimal and has been done in
- * 1.5.4 betas simply to enable external critique and testing (i.e. to
- * implement the new API quickly, without lots of internal changes.)
- */
-
-#ifdef PNG_READ_GAMMA_SUPPORTED
-# ifdef PNG_READ_BACKGROUND_SUPPORTED
- /* Includes ALPHA_MODE */
- png_ptr->background_1 = png_ptr->background;
-# endif
-
- /* This needs to change - in the palette image case a whole set of tables are
- * built when it would be quicker to just calculate the correct value for
- * each palette entry directly. Also, the test is too tricky - why check
- * PNG_RGB_TO_GRAY if PNG_GAMMA is not set? The answer seems to be that
- * PNG_GAMMA is cancelled even if the gamma is known? The test excludes the
- * PNG_COMPOSE case, so apparently if there is no *overall* gamma correction
- * the gamma tables will not be built even if composition is required on a
- * gamma encoded value.
- *
- * In 1.5.4 this is addressed below by an additional check on the individual
- * file gamma - if it is not 1.0 both RGB_TO_GRAY and COMPOSE need the
- * tables.
- */
- if ((png_ptr->transformations & PNG_GAMMA)
- || ((png_ptr->transformations & PNG_RGB_TO_GRAY)
- && (png_gamma_significant(png_ptr->colorspace.gamma) ||
- png_gamma_significant(png_ptr->screen_gamma)))
- || ((png_ptr->transformations & PNG_COMPOSE)
- && (png_gamma_significant(png_ptr->colorspace.gamma)
- || png_gamma_significant(png_ptr->screen_gamma)
-# ifdef PNG_READ_BACKGROUND_SUPPORTED
- || (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_UNIQUE
- && png_gamma_significant(png_ptr->background_gamma))
-# endif
- )) || ((png_ptr->transformations & PNG_ENCODE_ALPHA)
- && png_gamma_significant(png_ptr->screen_gamma))
- )
- {
- png_build_gamma_table(png_ptr, png_ptr->bit_depth);
-
-#ifdef PNG_READ_BACKGROUND_SUPPORTED
- if (png_ptr->transformations & PNG_COMPOSE)
- {
- /* Issue a warning about this combination: because RGB_TO_GRAY is
- * optimized to do the gamma transform if present yet do_background has
- * to do the same thing if both options are set a
- * double-gamma-correction happens. This is true in all versions of
- * libpng to date.
- */
- if (png_ptr->transformations & PNG_RGB_TO_GRAY)
- png_warning(png_ptr,
- "libpng does not support gamma+background+rgb_to_gray");
-
- if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
- {
- /* We don't get to here unless there is a tRNS chunk with non-opaque
- * entries - see the checking code at the start of this function.
- */
- png_color back, back_1;
- png_colorp palette = png_ptr->palette;
- int num_palette = png_ptr->num_palette;
- int i;
- if (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_FILE)
- {
-
- back.red = png_ptr->gamma_table[png_ptr->background.red];
- back.green = png_ptr->gamma_table[png_ptr->background.green];
- back.blue = png_ptr->gamma_table[png_ptr->background.blue];
-
- back_1.red = png_ptr->gamma_to_1[png_ptr->background.red];
- back_1.green = png_ptr->gamma_to_1[png_ptr->background.green];
- back_1.blue = png_ptr->gamma_to_1[png_ptr->background.blue];
- }
- else
- {
- png_fixed_point g, gs;
-
- switch (png_ptr->background_gamma_type)
- {
- case PNG_BACKGROUND_GAMMA_SCREEN:
- g = (png_ptr->screen_gamma);
- gs = PNG_FP_1;
- break;
-
- case PNG_BACKGROUND_GAMMA_FILE:
- g = png_reciprocal(png_ptr->colorspace.gamma);
- gs = png_reciprocal2(png_ptr->colorspace.gamma,
- png_ptr->screen_gamma);
- break;
-
- case PNG_BACKGROUND_GAMMA_UNIQUE:
- g = png_reciprocal(png_ptr->background_gamma);
- gs = png_reciprocal2(png_ptr->background_gamma,
- png_ptr->screen_gamma);
- break;
- default:
- g = PNG_FP_1; /* back_1 */
- gs = PNG_FP_1; /* back */
- break;
- }
-
- if (png_gamma_significant(gs))
- {
- back.red = png_gamma_8bit_correct(png_ptr->background.red,
- gs);
- back.green = png_gamma_8bit_correct(png_ptr->background.green,
- gs);
- back.blue = png_gamma_8bit_correct(png_ptr->background.blue,
- gs);
- }
-
- else
- {
- back.red = (png_byte)png_ptr->background.red;
- back.green = (png_byte)png_ptr->background.green;
- back.blue = (png_byte)png_ptr->background.blue;
- }
-
- if (png_gamma_significant(g))
- {
- back_1.red = png_gamma_8bit_correct(png_ptr->background.red,
- g);
- back_1.green = png_gamma_8bit_correct(
- png_ptr->background.green, g);
- back_1.blue = png_gamma_8bit_correct(png_ptr->background.blue,
- g);
- }
-
- else
- {
- back_1.red = (png_byte)png_ptr->background.red;
- back_1.green = (png_byte)png_ptr->background.green;
- back_1.blue = (png_byte)png_ptr->background.blue;
- }
- }
-
- for (i = 0; i < num_palette; i++)
- {
- if (i < (int)png_ptr->num_trans &&
- png_ptr->trans_alpha[i] != 0xff)
- {
- if (png_ptr->trans_alpha[i] == 0)
- {
- palette[i] = back;
- }
- else /* if (png_ptr->trans_alpha[i] != 0xff) */
- {
- png_byte v, w;
-
- v = png_ptr->gamma_to_1[palette[i].red];
- png_composite(w, v, png_ptr->trans_alpha[i], back_1.red);
- palette[i].red = png_ptr->gamma_from_1[w];
-
- v = png_ptr->gamma_to_1[palette[i].green];
- png_composite(w, v, png_ptr->trans_alpha[i], back_1.green);
- palette[i].green = png_ptr->gamma_from_1[w];
-
- v = png_ptr->gamma_to_1[palette[i].blue];
- png_composite(w, v, png_ptr->trans_alpha[i], back_1.blue);
- palette[i].blue = png_ptr->gamma_from_1[w];
- }
- }
- else
- {
- palette[i].red = png_ptr->gamma_table[palette[i].red];
- palette[i].green = png_ptr->gamma_table[palette[i].green];
- palette[i].blue = png_ptr->gamma_table[palette[i].blue];
- }
- }
-
- /* Prevent the transformations being done again.
- *
- * NOTE: this is highly dubious; it removes the transformations in
- * place. This seems inconsistent with the general treatment of the
- * transformations elsewhere.
- */
- png_ptr->transformations &= ~(PNG_COMPOSE | PNG_GAMMA);
- } /* color_type == PNG_COLOR_TYPE_PALETTE */
-
- /* if (png_ptr->background_gamma_type!=PNG_BACKGROUND_GAMMA_UNKNOWN) */
- else /* color_type != PNG_COLOR_TYPE_PALETTE */
- {
- int gs_sig, g_sig;
- png_fixed_point g = PNG_FP_1; /* Correction to linear */
- png_fixed_point gs = PNG_FP_1; /* Correction to screen */
-
- switch (png_ptr->background_gamma_type)
- {
- case PNG_BACKGROUND_GAMMA_SCREEN:
- g = png_ptr->screen_gamma;
- /* gs = PNG_FP_1; */
- break;
-
- case PNG_BACKGROUND_GAMMA_FILE:
- g = png_reciprocal(png_ptr->colorspace.gamma);
- gs = png_reciprocal2(png_ptr->colorspace.gamma,
- png_ptr->screen_gamma);
- break;
-
- case PNG_BACKGROUND_GAMMA_UNIQUE:
- g = png_reciprocal(png_ptr->background_gamma);
- gs = png_reciprocal2(png_ptr->background_gamma,
- png_ptr->screen_gamma);
- break;
-
- default:
- png_error(png_ptr, "invalid background gamma type");
- }
-
- g_sig = png_gamma_significant(g);
- gs_sig = png_gamma_significant(gs);
-
- if (g_sig)
- png_ptr->background_1.gray = png_gamma_correct(png_ptr,
- png_ptr->background.gray, g);
-
- if (gs_sig)
- png_ptr->background.gray = png_gamma_correct(png_ptr,
- png_ptr->background.gray, gs);
-
- if ((png_ptr->background.red != png_ptr->background.green) ||
- (png_ptr->background.red != png_ptr->background.blue) ||
- (png_ptr->background.red != png_ptr->background.gray))
- {
- /* RGB or RGBA with color background */
- if (g_sig)
- {
- png_ptr->background_1.red = png_gamma_correct(png_ptr,
- png_ptr->background.red, g);
-
- png_ptr->background_1.green = png_gamma_correct(png_ptr,
- png_ptr->background.green, g);
-
- png_ptr->background_1.blue = png_gamma_correct(png_ptr,
- png_ptr->background.blue, g);
- }
-
- if (gs_sig)
- {
- png_ptr->background.red = png_gamma_correct(png_ptr,
- png_ptr->background.red, gs);
-
- png_ptr->background.green = png_gamma_correct(png_ptr,
- png_ptr->background.green, gs);
-
- png_ptr->background.blue = png_gamma_correct(png_ptr,
- png_ptr->background.blue, gs);
- }
- }
-
- else
- {
- /* GRAY, GRAY ALPHA, RGB, or RGBA with gray background */
- png_ptr->background_1.red = png_ptr->background_1.green
- = png_ptr->background_1.blue = png_ptr->background_1.gray;
-
- png_ptr->background.red = png_ptr->background.green
- = png_ptr->background.blue = png_ptr->background.gray;
- }
-
- /* The background is now in screen gamma: */
- png_ptr->background_gamma_type = PNG_BACKGROUND_GAMMA_SCREEN;
- } /* color_type != PNG_COLOR_TYPE_PALETTE */
- }/* png_ptr->transformations & PNG_BACKGROUND */
-
- else
- /* Transformation does not include PNG_BACKGROUND */
-#endif /* PNG_READ_BACKGROUND_SUPPORTED */
- if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE
-#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
- /* RGB_TO_GRAY needs to have non-gamma-corrected values! */
- && ((png_ptr->transformations & PNG_EXPAND) == 0 ||
- (png_ptr->transformations & PNG_RGB_TO_GRAY) == 0)
-#endif
- )
- {
- png_colorp palette = png_ptr->palette;
- int num_palette = png_ptr->num_palette;
- int i;
-
- /* NOTE: there are other transformations that should probably be in
- * here too.
- */
- for (i = 0; i < num_palette; i++)
- {
- palette[i].red = png_ptr->gamma_table[palette[i].red];
- palette[i].green = png_ptr->gamma_table[palette[i].green];
- palette[i].blue = png_ptr->gamma_table[palette[i].blue];
- }
-
- /* Done the gamma correction. */
- png_ptr->transformations &= ~PNG_GAMMA;
- } /* color_type == PALETTE && !PNG_BACKGROUND transformation */
- }
-#ifdef PNG_READ_BACKGROUND_SUPPORTED
- else
-#endif
-#endif /* PNG_READ_GAMMA_SUPPORTED */
-
-#ifdef PNG_READ_BACKGROUND_SUPPORTED
- /* No GAMMA transformation (see the hanging else 4 lines above) */
- if ((png_ptr->transformations & PNG_COMPOSE) &&
- (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE))
- {
- int i;
- int istop = (int)png_ptr->num_trans;
- png_color back;
- png_colorp palette = png_ptr->palette;
-
- back.red = (png_byte)png_ptr->background.red;
- back.green = (png_byte)png_ptr->background.green;
- back.blue = (png_byte)png_ptr->background.blue;
-
- for (i = 0; i < istop; i++)
- {
- if (png_ptr->trans_alpha[i] == 0)
- {
- palette[i] = back;
- }
-
- else if (png_ptr->trans_alpha[i] != 0xff)
- {
- /* The png_composite() macro is defined in png.h */
- png_composite(palette[i].red, palette[i].red,
- png_ptr->trans_alpha[i], back.red);
-
- png_composite(palette[i].green, palette[i].green,
- png_ptr->trans_alpha[i], back.green);
-
- png_composite(palette[i].blue, palette[i].blue,
- png_ptr->trans_alpha[i], back.blue);
- }
- }
-
- png_ptr->transformations &= ~PNG_COMPOSE;
-
- //png_ptr->flags |= PNG_FLAG_STRIP_ALPHA; /* Add by Sunliang.Liu */
- }
-#endif /* PNG_READ_BACKGROUND_SUPPORTED */
-
-#ifdef PNG_READ_SHIFT_SUPPORTED
- if ((png_ptr->transformations & PNG_SHIFT) &&
- !(png_ptr->transformations & PNG_EXPAND) &&
- (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE))
- {
- int i;
- int istop = png_ptr->num_palette;
- int shift = 8 - png_ptr->sig_bit.red;
-
- png_ptr->transformations &= ~PNG_SHIFT;
-
- /* significant bits can be in the range 1 to 7 for a meaninful result, if
- * the number of significant bits is 0 then no shift is done (this is an
- * error condition which is silently ignored.)
- */
- if (shift > 0 && shift < 8) for (i=0; i<istop; ++i)
- {
- int component = png_ptr->palette[i].red;
-
- component >>= shift;
- png_ptr->palette[i].red = (png_byte)component;
- }
-
- shift = 8 - png_ptr->sig_bit.green;
- if (shift > 0 && shift < 8) for (i=0; i<istop; ++i)
- {
- int component = png_ptr->palette[i].green;
-
- component >>= shift;
- png_ptr->palette[i].green = (png_byte)component;
- }
-
- shift = 8 - png_ptr->sig_bit.blue;
- if (shift > 0 && shift < 8) for (i=0; i<istop; ++i)
- {
- int component = png_ptr->palette[i].blue;
-
- component >>= shift;
- png_ptr->palette[i].blue = (png_byte)component;
- }
- }
-#endif /* PNG_READ_SHIFT_SUPPORTED */
-}
-
-/* Modify the info structure to reflect the transformations. The
- * info should be updated so a PNG file could be written with it,
- * assuming the transformations result in valid PNG data.
- */
-void /* PRIVATE */
-png_read_transform_info(png_structrp png_ptr, png_inforp info_ptr)
-{
- png_debug(1, "in png_read_transform_info");
-
-#ifdef PNG_READ_EXPAND_SUPPORTED
- if (png_ptr->transformations & PNG_EXPAND)
- {
- if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
- {
- /* This check must match what actually happens in
- * png_do_expand_palette; if it ever checks the tRNS chunk to see if
- * it is all opaque we must do the same (at present it does not.)
- */
- if (png_ptr->num_trans > 0)
- info_ptr->color_type = PNG_COLOR_TYPE_RGB_ALPHA;
-
- else
- info_ptr->color_type = PNG_COLOR_TYPE_RGB;
-
- info_ptr->bit_depth = 8;
- info_ptr->num_trans = 0;
- }
- else
- {
- if (png_ptr->num_trans)
- {
- if (png_ptr->transformations & PNG_EXPAND_tRNS)
- info_ptr->color_type |= PNG_COLOR_MASK_ALPHA;
- }
- if (info_ptr->bit_depth < 8)
- info_ptr->bit_depth = 8;
-
- info_ptr->num_trans = 0;
- }
- }
-#endif
-
-#if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\
- defined(PNG_READ_ALPHA_MODE_SUPPORTED)
- /* The following is almost certainly wrong unless the background value is in
- * the screen space!
- */
- if (png_ptr->transformations & PNG_COMPOSE)
- info_ptr->background = png_ptr->background;
-#endif
-
-#ifdef PNG_READ_GAMMA_SUPPORTED
- /* The following used to be conditional on PNG_GAMMA (prior to 1.5.4),
- * however it seems that the code in png_init_read_transformations, which has
- * been called before this from png_read_update_info->png_read_start_row
- * sometimes does the gamma transform and cancels the flag.
- *
- * TODO: this looks wrong; the info_ptr should end up with a gamma equal to
- * the screen_gamma value. The following probably results in weirdness if
- * the info_ptr is used by the app after the rows have been read.
- */
- info_ptr->colorspace.gamma = png_ptr->colorspace.gamma;
-#endif
-
- if (info_ptr->bit_depth == 16)
- {
-# ifdef PNG_READ_16BIT_SUPPORTED
-# ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
- if (png_ptr->transformations & PNG_SCALE_16_TO_8)
- info_ptr->bit_depth = 8;
-# endif
-
-# ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
- if (png_ptr->transformations & PNG_16_TO_8)
- info_ptr->bit_depth = 8;
-# endif
-
-# else
- /* No 16 bit support: force chopping 16-bit input down to 8, in this case
- * the app program can chose if both APIs are available by setting the
- * correct scaling to use.
- */
-# ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
- /* For compatibility with previous versions use the strip method by
- * default. This code works because if PNG_SCALE_16_TO_8 is already
- * set the code below will do that in preference to the chop.
- */
- png_ptr->transformations |= PNG_16_TO_8;
- info_ptr->bit_depth = 8;
-# else
-
-# ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
- png_ptr->transformations |= PNG_SCALE_16_TO_8;
- info_ptr->bit_depth = 8;
-# else
-
- CONFIGURATION ERROR: you must enable at least one 16 to 8 method
-# endif
-# endif
-#endif /* !READ_16BIT_SUPPORTED */
- }
-
-#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
- if (png_ptr->transformations & PNG_GRAY_TO_RGB)
- info_ptr->color_type = (png_byte)(info_ptr->color_type |
- PNG_COLOR_MASK_COLOR);
-#endif
-
-#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
- if (png_ptr->transformations & PNG_RGB_TO_GRAY)
- info_ptr->color_type = (png_byte)(info_ptr->color_type &
- ~PNG_COLOR_MASK_COLOR);
-#endif
-
-#ifdef PNG_READ_QUANTIZE_SUPPORTED
- if (png_ptr->transformations & PNG_QUANTIZE)
- {
- if (((info_ptr->color_type == PNG_COLOR_TYPE_RGB) ||
- (info_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA)) &&
- png_ptr->palette_lookup && info_ptr->bit_depth == 8)
- {
- info_ptr->color_type = PNG_COLOR_TYPE_PALETTE;
- }
- }
-#endif
-
-#ifdef PNG_READ_EXPAND_16_SUPPORTED
- if (png_ptr->transformations & PNG_EXPAND_16 && info_ptr->bit_depth == 8 &&
- info_ptr->color_type != PNG_COLOR_TYPE_PALETTE)
- {
- info_ptr->bit_depth = 16;
- }
-#endif
-
-#ifdef PNG_READ_PACK_SUPPORTED
- if ((png_ptr->transformations & PNG_PACK) && (info_ptr->bit_depth < 8))
- info_ptr->bit_depth = 8;
-#endif
-
- if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
- info_ptr->channels = 1;
-
- else if (info_ptr->color_type & PNG_COLOR_MASK_COLOR)
- info_ptr->channels = 3;
-
- else
- info_ptr->channels = 1;
-
-#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
- if (png_ptr->transformations & PNG_STRIP_ALPHA)
- {
- info_ptr->color_type = (png_byte)(info_ptr->color_type &
- ~PNG_COLOR_MASK_ALPHA);
- info_ptr->num_trans = 0;
- }
-#endif
-
- if (info_ptr->color_type & PNG_COLOR_MASK_ALPHA)
- info_ptr->channels++;
-
-#ifdef PNG_READ_FILLER_SUPPORTED
- /* STRIP_ALPHA and FILLER allowed: MASK_ALPHA bit stripped above */
- if ((png_ptr->transformations & PNG_FILLER) &&
- ((info_ptr->color_type == PNG_COLOR_TYPE_RGB) ||
- (info_ptr->color_type == PNG_COLOR_TYPE_GRAY)))
- {
- info_ptr->channels++;
- /* If adding a true alpha channel not just filler */
- if (png_ptr->transformations & PNG_ADD_ALPHA)
- info_ptr->color_type |= PNG_COLOR_MASK_ALPHA;
- }
-#endif
-
-#if defined(PNG_USER_TRANSFORM_PTR_SUPPORTED) && \
-defined(PNG_READ_USER_TRANSFORM_SUPPORTED)
- if (png_ptr->transformations & PNG_USER_TRANSFORM)
- {
- if (info_ptr->bit_depth < png_ptr->user_transform_depth)
- info_ptr->bit_depth = png_ptr->user_transform_depth;
-
- if (info_ptr->channels < png_ptr->user_transform_channels)
- info_ptr->channels = png_ptr->user_transform_channels;
- }
-#endif
-
- info_ptr->pixel_depth = (png_byte)(info_ptr->channels *
- info_ptr->bit_depth);
-
- info_ptr->rowbytes = PNG_ROWBYTES(info_ptr->pixel_depth, info_ptr->width);
-
- /* Adding in 1.5.4: cache the above value in png_struct so that we can later
- * check in png_rowbytes that the user buffer won't get overwritten. Note
- * that the field is not always set - if png_read_update_info isn't called
- * the application has to either not do any transforms or get the calculation
- * right itself.
- */
- png_ptr->info_rowbytes = info_ptr->rowbytes;
-
-#ifndef PNG_READ_EXPAND_SUPPORTED
- if (png_ptr)
- return;
-#endif
-}
-
-/* Transform the row. The order of transformations is significant,
- * and is very touchy. If you add a transformation, take care to
- * decide how it fits in with the other transformations here.
- */
-void /* PRIVATE */
-png_do_read_transformations(png_structrp png_ptr, png_row_infop row_info)
-{
- png_debug(1, "in png_do_read_transformations");
-
- if (png_ptr->row_buf == NULL)
- {
- /* Prior to 1.5.4 this output row/pass where the NULL pointer is, but this
- * error is incredibly rare and incredibly easy to debug without this
- * information.
- */
- png_error(png_ptr, "NULL row buffer");
- }
-
- /* The following is debugging; prior to 1.5.4 the code was never compiled in;
- * in 1.5.4 PNG_FLAG_DETECT_UNINITIALIZED was added and the macro
- * PNG_WARN_UNINITIALIZED_ROW removed. In 1.6 the new flag is set only for
- * all transformations, however in practice the ROW_INIT always gets done on
- * demand, if necessary.
- */
- if ((png_ptr->flags & PNG_FLAG_DETECT_UNINITIALIZED) != 0 &&
- !(png_ptr->flags & PNG_FLAG_ROW_INIT))
- {
- /* Application has failed to call either png_read_start_image() or
- * png_read_update_info() after setting transforms that expand pixels.
- * This check added to libpng-1.2.19 (but not enabled until 1.5.4).
- */
- png_error(png_ptr, "Uninitialized row");
- }
-
-#ifdef PNG_READ_EXPAND_SUPPORTED
- if (png_ptr->transformations & PNG_EXPAND)
- {
- if (row_info->color_type == PNG_COLOR_TYPE_PALETTE)
- {
- png_do_expand_palette(row_info, png_ptr->row_buf + 1,
- png_ptr->palette, png_ptr->trans_alpha, png_ptr->num_trans);
- }
-
- else
- {
- if (png_ptr->num_trans &&
- (png_ptr->transformations & PNG_EXPAND_tRNS))
- png_do_expand(row_info, png_ptr->row_buf + 1,
- &(png_ptr->trans_color));
-
- else
- png_do_expand(row_info, png_ptr->row_buf + 1,
- NULL);
- }
- }
-#endif
-
-#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
- if ((png_ptr->transformations & PNG_STRIP_ALPHA) &&
- !(png_ptr->transformations & PNG_COMPOSE) &&
- (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA ||
- row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA))
- png_do_strip_channel(row_info, png_ptr->row_buf + 1,
- 0 /* at_start == false, because SWAP_ALPHA happens later */);
-#endif
-
-#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
- if (png_ptr->transformations & PNG_RGB_TO_GRAY)
- {
- int rgb_error =
- png_do_rgb_to_gray(png_ptr, row_info,
- png_ptr->row_buf + 1);
-
- if (rgb_error)
- {
- png_ptr->rgb_to_gray_status=1;
- if ((png_ptr->transformations & PNG_RGB_TO_GRAY) ==
- PNG_RGB_TO_GRAY_WARN)
- png_warning(png_ptr, "png_do_rgb_to_gray found nongray pixel");
-
- if ((png_ptr->transformations & PNG_RGB_TO_GRAY) ==
- PNG_RGB_TO_GRAY_ERR)
- png_error(png_ptr, "png_do_rgb_to_gray found nongray pixel");
- }
- }
-#endif
-
-/* From Andreas Dilger e-mail to png-implement, 26 March 1998:
- *
- * In most cases, the "simple transparency" should be done prior to doing
- * gray-to-RGB, or you will have to test 3x as many bytes to check if a
- * pixel is transparent. You would also need to make sure that the
- * transparency information is upgraded to RGB.
- *
- * To summarize, the current flow is:
- * - Gray + simple transparency -> compare 1 or 2 gray bytes and composite
- * with background "in place" if transparent,
- * convert to RGB if necessary
- * - Gray + alpha -> composite with gray background and remove alpha bytes,
- * convert to RGB if necessary
- *
- * To support RGB backgrounds for gray images we need:
- * - Gray + simple transparency -> convert to RGB + simple transparency,
- * compare 3 or 6 bytes and composite with
- * background "in place" if transparent
- * (3x compare/pixel compared to doing
- * composite with gray bkgrnd)
- * - Gray + alpha -> convert to RGB + alpha, composite with background and
- * remove alpha bytes (3x float
- * operations/pixel compared with composite
- * on gray background)
- *
- * Greg's change will do this. The reason it wasn't done before is for
- * performance, as this increases the per-pixel operations. If we would check
- * in advance if the background was gray or RGB, and position the gray-to-RGB
- * transform appropriately, then it would save a lot of work/time.
- */
-
-#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
- /* If gray -> RGB, do so now only if background is non-gray; else do later
- * for performance reasons
- */
- if ((png_ptr->transformations & PNG_GRAY_TO_RGB) &&
- !(png_ptr->mode & PNG_BACKGROUND_IS_GRAY))
- png_do_gray_to_rgb(row_info, png_ptr->row_buf + 1);
-#endif
-
-#if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\
- defined(PNG_READ_ALPHA_MODE_SUPPORTED)
- if (png_ptr->transformations & PNG_COMPOSE)
- png_do_compose(row_info, png_ptr->row_buf + 1, png_ptr);
-#endif
-
-#ifdef PNG_READ_GAMMA_SUPPORTED
- if ((png_ptr->transformations & PNG_GAMMA) &&
-#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
- /* Because RGB_TO_GRAY does the gamma transform. */
- !(png_ptr->transformations & PNG_RGB_TO_GRAY) &&
-#endif
-#if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\
- defined(PNG_READ_ALPHA_MODE_SUPPORTED)
- /* Because PNG_COMPOSE does the gamma transform if there is something to
- * do (if there is an alpha channel or transparency.)
- */
- !((png_ptr->transformations & PNG_COMPOSE) &&
- ((png_ptr->num_trans != 0) ||
- (png_ptr->color_type & PNG_COLOR_MASK_ALPHA))) &&
-#endif
- /* Because png_init_read_transformations transforms the palette, unless
- * RGB_TO_GRAY will do the transform.
- */
- (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE))
- png_do_gamma(row_info, png_ptr->row_buf + 1, png_ptr);
-#endif
-
-#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
- if ((png_ptr->transformations & PNG_STRIP_ALPHA) &&
- (png_ptr->transformations & PNG_COMPOSE) &&
- (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA ||
- row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA))
- png_do_strip_channel(row_info, png_ptr->row_buf + 1,
- 0 /* at_start == false, because SWAP_ALPHA happens later */);
-#endif
-
-#ifdef PNG_READ_ALPHA_MODE_SUPPORTED
- if ((png_ptr->transformations & PNG_ENCODE_ALPHA) &&
- (row_info->color_type & PNG_COLOR_MASK_ALPHA))
- png_do_encode_alpha(row_info, png_ptr->row_buf + 1, png_ptr);
-#endif
-
-#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
- if (png_ptr->transformations & PNG_SCALE_16_TO_8)
- png_do_scale_16_to_8(row_info, png_ptr->row_buf + 1);
-#endif
-
-#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
- /* There is no harm in doing both of these because only one has any effect,
- * by putting the 'scale' option first if the app asks for scale (either by
- * calling the API or in a TRANSFORM flag) this is what happens.
- */
- if (png_ptr->transformations & PNG_16_TO_8)
- png_do_chop(row_info, png_ptr->row_buf + 1);
-#endif
-
-#ifdef PNG_READ_QUANTIZE_SUPPORTED
- if (png_ptr->transformations & PNG_QUANTIZE)
- {
- png_do_quantize(row_info, png_ptr->row_buf + 1,
- png_ptr->palette_lookup, png_ptr->quantize_index);
-
- if (row_info->rowbytes == 0)
- png_error(png_ptr, "png_do_quantize returned rowbytes=0");
- }
-#endif /* PNG_READ_QUANTIZE_SUPPORTED */
-
-#ifdef PNG_READ_EXPAND_16_SUPPORTED
- /* Do the expansion now, after all the arithmetic has been done. Notice
- * that previous transformations can handle the PNG_EXPAND_16 flag if this
- * is efficient (particularly true in the case of gamma correction, where
- * better accuracy results faster!)
- */
- if (png_ptr->transformations & PNG_EXPAND_16)
- png_do_expand_16(row_info, png_ptr->row_buf + 1);
-#endif
-
-#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
- /* NOTE: moved here in 1.5.4 (from much later in this list.) */
- if ((png_ptr->transformations & PNG_GRAY_TO_RGB) &&
- (png_ptr->mode & PNG_BACKGROUND_IS_GRAY))
- png_do_gray_to_rgb(row_info, png_ptr->row_buf + 1);
-#endif
-
-#ifdef PNG_READ_INVERT_SUPPORTED
- if (png_ptr->transformations & PNG_INVERT_MONO)
- png_do_invert(row_info, png_ptr->row_buf + 1);
-#endif
-
-#ifdef PNG_READ_SHIFT_SUPPORTED
- if (png_ptr->transformations & PNG_SHIFT)
- png_do_unshift(row_info, png_ptr->row_buf + 1,
- &(png_ptr->shift));
-#endif
-
-#ifdef PNG_READ_PACK_SUPPORTED
- if (png_ptr->transformations & PNG_PACK)
- png_do_unpack(row_info, png_ptr->row_buf + 1);
-#endif
-
-#ifdef PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED
- /* Added at libpng-1.5.10 */
- if (row_info->color_type == PNG_COLOR_TYPE_PALETTE &&
- png_ptr->num_palette_max >= 0)
- png_do_check_palette_indexes(png_ptr, row_info);
-#endif
-
-#ifdef PNG_READ_BGR_SUPPORTED
- if (png_ptr->transformations & PNG_BGR)
- png_do_bgr(row_info, png_ptr->row_buf + 1);
-#endif
-
-#ifdef PNG_READ_PACKSWAP_SUPPORTED
- if (png_ptr->transformations & PNG_PACKSWAP)
- png_do_packswap(row_info, png_ptr->row_buf + 1);
-#endif
-
-#ifdef PNG_READ_FILLER_SUPPORTED
- if (png_ptr->transformations & PNG_FILLER)
- png_do_read_filler(row_info, png_ptr->row_buf + 1,
- (png_uint_32)png_ptr->filler, png_ptr->flags);
-#endif
-
-#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED
- if (png_ptr->transformations & PNG_INVERT_ALPHA)
- png_do_read_invert_alpha(row_info, png_ptr->row_buf + 1);
-#endif
-
-#ifdef PNG_READ_SWAP_ALPHA_SUPPORTED
- if (png_ptr->transformations & PNG_SWAP_ALPHA)
- png_do_read_swap_alpha(row_info, png_ptr->row_buf + 1);
-#endif
-
-#ifdef PNG_READ_16BIT_SUPPORTED
-#ifdef PNG_READ_SWAP_SUPPORTED
- if (png_ptr->transformations & PNG_SWAP_BYTES)
- png_do_swap(row_info, png_ptr->row_buf + 1);
-#endif
-#endif
-
-#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
- if (png_ptr->transformations & PNG_USER_TRANSFORM)
- {
- if (png_ptr->read_user_transform_fn != NULL)
- (*(png_ptr->read_user_transform_fn)) /* User read transform function */
- (png_ptr, /* png_ptr */
- row_info, /* row_info: */
- /* png_uint_32 width; width of row */
- /* png_size_t rowbytes; number of bytes in row */
- /* png_byte color_type; color type of pixels */
- /* png_byte bit_depth; bit depth of samples */
- /* png_byte channels; number of channels (1-4) */
- /* png_byte pixel_depth; bits per pixel (depth*channels) */
- png_ptr->row_buf + 1); /* start of pixel data for row */
-#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
- if (png_ptr->user_transform_depth)
- row_info->bit_depth = png_ptr->user_transform_depth;
-
- if (png_ptr->user_transform_channels)
- row_info->channels = png_ptr->user_transform_channels;
-#endif
- row_info->pixel_depth = (png_byte)(row_info->bit_depth *
- row_info->channels);
-
- row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_info->width);
- }
-#endif
-}
-
-#ifdef PNG_READ_PACK_SUPPORTED
-/* Unpack pixels of 1, 2, or 4 bits per pixel into 1 byte per pixel,
- * without changing the actual values. Thus, if you had a row with
- * a bit depth of 1, you would end up with bytes that only contained
- * the numbers 0 or 1. If you would rather they contain 0 and 255, use
- * png_do_shift() after this.
- */
-void /* PRIVATE */
-png_do_unpack(png_row_infop row_info, png_bytep row)
-{
- png_debug(1, "in png_do_unpack");
-
- if (row_info->bit_depth < 8)
- {
- png_uint_32 i;
- png_uint_32 row_width=row_info->width;
-
- switch (row_info->bit_depth)
- {
- case 1:
- {
- png_bytep sp = row + (png_size_t)((row_width - 1) >> 3);
- png_bytep dp = row + (png_size_t)row_width - 1;
- png_uint_32 shift = 7 - (int)((row_width + 7) & 0x07);
- for (i = 0; i < row_width; i++)
- {
- *dp = (png_byte)((*sp >> shift) & 0x01);
-
- if (shift == 7)
- {
- shift = 0;
- sp--;
- }
-
- else
- shift++;
-
- dp--;
- }
- break;
- }
-
- case 2:
- {
-
- png_bytep sp = row + (png_size_t)((row_width - 1) >> 2);
- png_bytep dp = row + (png_size_t)row_width - 1;
- png_uint_32 shift = (int)((3 - ((row_width + 3) & 0x03)) << 1);
- for (i = 0; i < row_width; i++)
- {
- *dp = (png_byte)((*sp >> shift) & 0x03);
-
- if (shift == 6)
- {
- shift = 0;
- sp--;
- }
-
- else
- shift += 2;
-
- dp--;
- }
- break;
- }
-
- case 4:
- {
- png_bytep sp = row + (png_size_t)((row_width - 1) >> 1);
- png_bytep dp = row + (png_size_t)row_width - 1;
- png_uint_32 shift = (int)((1 - ((row_width + 1) & 0x01)) << 2);
- for (i = 0; i < row_width; i++)
- {
- *dp = (png_byte)((*sp >> shift) & 0x0f);
-
- if (shift == 4)
- {
- shift = 0;
- sp--;
- }
-
- else
- shift = 4;
-
- dp--;
- }
- break;
- }
-
- default:
- break;
- }
- row_info->bit_depth = 8;
- row_info->pixel_depth = (png_byte)(8 * row_info->channels);
- row_info->rowbytes = row_width * row_info->channels;
- }
-}
-#endif
-
-#ifdef PNG_READ_SHIFT_SUPPORTED
-/* Reverse the effects of png_do_shift. This routine merely shifts the
- * pixels back to their significant bits values. Thus, if you have
- * a row of bit depth 8, but only 5 are significant, this will shift
- * the values back to 0 through 31.
- */
-void /* PRIVATE */
-png_do_unshift(png_row_infop row_info, png_bytep row,
- png_const_color_8p sig_bits)
-{
- int color_type;
-
- png_debug(1, "in png_do_unshift");
-
- /* The palette case has already been handled in the _init routine. */
- color_type = row_info->color_type;
-
- if (color_type != PNG_COLOR_TYPE_PALETTE)
- {
- int shift[4];
- int channels = 0;
- int bit_depth = row_info->bit_depth;
-
- if (color_type & PNG_COLOR_MASK_COLOR)
- {
- shift[channels++] = bit_depth - sig_bits->red;
- shift[channels++] = bit_depth - sig_bits->green;
- shift[channels++] = bit_depth - sig_bits->blue;
- }
-
- else
- {
- shift[channels++] = bit_depth - sig_bits->gray;
- }
-
- if (color_type & PNG_COLOR_MASK_ALPHA)
- {
- shift[channels++] = bit_depth - sig_bits->alpha;
- }
-
- {
- int c, have_shift;
-
- for (c = have_shift = 0; c < channels; ++c)
- {
- /* A shift of more than the bit depth is an error condition but it
- * gets ignored here.
- */
- if (shift[c] <= 0 || shift[c] >= bit_depth)
- shift[c] = 0;
-
- else
- have_shift = 1;
- }
-
- if (!have_shift)
- return;
- }
-
- switch (bit_depth)
- {
- default:
- /* Must be 1bpp gray: should not be here! */
- /* NOTREACHED */
- break;
-
- case 2:
- /* Must be 2bpp gray */
- /* assert(channels == 1 && shift[0] == 1) */
- {
- png_bytep bp = row;
- png_bytep bp_end = bp + row_info->rowbytes;
-
- while (bp < bp_end)
- {
- int b = (*bp >> 1) & 0x55;
- *bp++ = (png_byte)b;
- }
- break;
- }
-
- case 4:
- /* Must be 4bpp gray */
- /* assert(channels == 1) */
- {
- png_bytep bp = row;
- png_bytep bp_end = bp + row_info->rowbytes;
- int gray_shift = shift[0];
- int mask = 0xf >> gray_shift;
-
- mask |= mask << 4;
-
- while (bp < bp_end)
- {
- int b = (*bp >> gray_shift) & mask;
- *bp++ = (png_byte)b;
- }
- break;
- }
-
- case 8:
- /* Single byte components, G, GA, RGB, RGBA */
- {
- png_bytep bp = row;
- png_bytep bp_end = bp + row_info->rowbytes;
- int channel = 0;
-
- while (bp < bp_end)
- {
- int b = *bp >> shift[channel];
- if (++channel >= channels)
- channel = 0;
- *bp++ = (png_byte)b;
- }
- break;
- }
-
-#ifdef PNG_READ_16BIT_SUPPORTED
- case 16:
- /* Double byte components, G, GA, RGB, RGBA */
- {
- png_bytep bp = row;
- png_bytep bp_end = bp + row_info->rowbytes;
- int channel = 0;
-
- while (bp < bp_end)
- {
- int value = (bp[0] << 8) + bp[1];
-
- value >>= shift[channel];
- if (++channel >= channels)
- channel = 0;
- *bp++ = (png_byte)(value >> 8);
- *bp++ = (png_byte)(value & 0xff);
- }
- break;
- }
-#endif
- }
- }
-}
-#endif
-
-#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
-/* Scale rows of bit depth 16 down to 8 accurately */
-void /* PRIVATE */
-png_do_scale_16_to_8(png_row_infop row_info, png_bytep row)
-{
- png_debug(1, "in png_do_scale_16_to_8");
-
- if (row_info->bit_depth == 16)
- {
- png_bytep sp = row; /* source */
- png_bytep dp = row; /* destination */
- png_bytep ep = sp + row_info->rowbytes; /* end+1 */
-
- while (sp < ep)
- {
- /* The input is an array of 16 bit components, these must be scaled to
- * 8 bits each. For a 16 bit value V the required value (from the PNG
- * specification) is:
- *
- * (V * 255) / 65535
- *
- * This reduces to round(V / 257), or floor((V + 128.5)/257)
- *
- * Represent V as the two byte value vhi.vlo. Make a guess that the
- * result is the top byte of V, vhi, then the correction to this value
- * is:
- *
- * error = floor(((V-vhi.vhi) + 128.5) / 257)
- * = floor(((vlo-vhi) + 128.5) / 257)
- *
- * This can be approximated using integer arithmetic (and a signed
- * shift):
- *
- * error = (vlo-vhi+128) >> 8;
- *
- * The approximate differs from the exact answer only when (vlo-vhi) is
- * 128; it then gives a correction of +1 when the exact correction is
- * 0. This gives 128 errors. The exact answer (correct for all 16 bit
- * input values) is:
- *
- * error = (vlo-vhi+128)*65535 >> 24;
- *
- * An alternative arithmetic calculation which also gives no errors is:
- *
- * (V * 255 + 32895) >> 16
- */
-
- png_int_32 tmp = *sp++; /* must be signed! */
- tmp += (((int)*sp++ - tmp + 128) * 65535) >> 24;
- *dp++ = (png_byte)tmp;
- }
-
- row_info->bit_depth = 8;
- row_info->pixel_depth = (png_byte)(8 * row_info->channels);
- row_info->rowbytes = row_info->width * row_info->channels;
- }
-}
-#endif
-
-#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
-void /* PRIVATE */
-/* Simply discard the low byte. This was the default behavior prior
- * to libpng-1.5.4.
- */
-png_do_chop(png_row_infop row_info, png_bytep row)
-{
- png_debug(1, "in png_do_chop");
-
- if (row_info->bit_depth == 16)
- {
- png_bytep sp = row; /* source */
- png_bytep dp = row; /* destination */
- png_bytep ep = sp + row_info->rowbytes; /* end+1 */
-
- while (sp < ep)
- {
- *dp++ = *sp;
- sp += 2; /* skip low byte */
- }
-
- row_info->bit_depth = 8;
- row_info->pixel_depth = (png_byte)(8 * row_info->channels);
- row_info->rowbytes = row_info->width * row_info->channels;
- }
-}
-#endif
-
-#ifdef PNG_READ_SWAP_ALPHA_SUPPORTED
-void /* PRIVATE */
-png_do_read_swap_alpha(png_row_infop row_info, png_bytep row)
-{
- png_debug(1, "in png_do_read_swap_alpha");
-
- {
- png_uint_32 row_width = row_info->width;
- if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
- {
- /* This converts from RGBA to ARGB */
- if (row_info->bit_depth == 8)
- {
- png_bytep sp = row + row_info->rowbytes;
- png_bytep dp = sp;
- png_byte save;
- png_uint_32 i;
-
- for (i = 0; i < row_width; i++)
- {
- save = *(--sp);
- *(--dp) = *(--sp);
- *(--dp) = *(--sp);
- *(--dp) = *(--sp);
- *(--dp) = save;
- }
- }
-
-#ifdef PNG_READ_16BIT_SUPPORTED
- /* This converts from RRGGBBAA to AARRGGBB */
- else
- {
- png_bytep sp = row + row_info->rowbytes;
- png_bytep dp = sp;
- png_byte save[2];
- png_uint_32 i;
-
- for (i = 0; i < row_width; i++)
- {
- save[0] = *(--sp);
- save[1] = *(--sp);
- *(--dp) = *(--sp);
- *(--dp) = *(--sp);
- *(--dp) = *(--sp);
- *(--dp) = *(--sp);
- *(--dp) = *(--sp);
- *(--dp) = *(--sp);
- *(--dp) = save[0];
- *(--dp) = save[1];
- }
- }
-#endif
- }
-
- else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
- {
- /* This converts from GA to AG */
- if (row_info->bit_depth == 8)
- {
- png_bytep sp = row + row_info->rowbytes;
- png_bytep dp = sp;
- png_byte save;
- png_uint_32 i;
-
- for (i = 0; i < row_width; i++)
- {
- save = *(--sp);
- *(--dp) = *(--sp);
- *(--dp) = save;
- }
- }
-
-#ifdef PNG_READ_16BIT_SUPPORTED
- /* This converts from GGAA to AAGG */
- else
- {
- png_bytep sp = row + row_info->rowbytes;
- png_bytep dp = sp;
- png_byte save[2];
- png_uint_32 i;
-
- for (i = 0; i < row_width; i++)
- {
- save[0] = *(--sp);
- save[1] = *(--sp);
- *(--dp) = *(--sp);
- *(--dp) = *(--sp);
- *(--dp) = save[0];
- *(--dp) = save[1];
- }
- }
-#endif
- }
- }
-}
-#endif
-
-#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED
-void /* PRIVATE */
-png_do_read_invert_alpha(png_row_infop row_info, png_bytep row)
-{
- png_uint_32 row_width;
- png_debug(1, "in png_do_read_invert_alpha");
-
- row_width = row_info->width;
- if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
- {
- if (row_info->bit_depth == 8)
- {
- /* This inverts the alpha channel in RGBA */
- png_bytep sp = row + row_info->rowbytes;
- png_bytep dp = sp;
- png_uint_32 i;
-
- for (i = 0; i < row_width; i++)
- {
- *(--dp) = (png_byte)(255 - *(--sp));
-
-/* This does nothing:
- *(--dp) = *(--sp);
- *(--dp) = *(--sp);
- *(--dp) = *(--sp);
- We can replace it with:
-*/
- sp-=3;
- dp=sp;
- }
- }
-
-#ifdef PNG_READ_16BIT_SUPPORTED
- /* This inverts the alpha channel in RRGGBBAA */
- else
- {
- png_bytep sp = row + row_info->rowbytes;
- png_bytep dp = sp;
- png_uint_32 i;
-
- for (i = 0; i < row_width; i++)
- {
- *(--dp) = (png_byte)(255 - *(--sp));
- *(--dp) = (png_byte)(255 - *(--sp));
-
-/* This does nothing:
- *(--dp) = *(--sp);
- *(--dp) = *(--sp);
- *(--dp) = *(--sp);
- *(--dp) = *(--sp);
- *(--dp) = *(--sp);
- *(--dp) = *(--sp);
- We can replace it with:
-*/
- sp-=6;
- dp=sp;
- }
- }
-#endif
- }
- else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
- {
- if (row_info->bit_depth == 8)
- {
- /* This inverts the alpha channel in GA */
- png_bytep sp = row + row_info->rowbytes;
- png_bytep dp = sp;
- png_uint_32 i;
-
- for (i = 0; i < row_width; i++)
- {
- *(--dp) = (png_byte)(255 - *(--sp));
- *(--dp) = *(--sp);
- }
- }
-
-#ifdef PNG_READ_16BIT_SUPPORTED
- else
- {
- /* This inverts the alpha channel in GGAA */
- png_bytep sp = row + row_info->rowbytes;
- png_bytep dp = sp;
- png_uint_32 i;
-
- for (i = 0; i < row_width; i++)
- {
- *(--dp) = (png_byte)(255 - *(--sp));
- *(--dp) = (png_byte)(255 - *(--sp));
-/*
- *(--dp) = *(--sp);
- *(--dp) = *(--sp);
-*/
- sp-=2;
- dp=sp;
- }
- }
-#endif
- }
-}
-#endif
-
-#ifdef PNG_READ_FILLER_SUPPORTED
-/* Add filler channel if we have RGB color */
-void /* PRIVATE */
-png_do_read_filler(png_row_infop row_info, png_bytep row,
- png_uint_32 filler, png_uint_32 flags)
-{
- png_uint_32 i;
- png_uint_32 row_width = row_info->width;
-
-#ifdef PNG_READ_16BIT_SUPPORTED
- png_byte hi_filler = (png_byte)((filler>>8) & 0xff);
-#endif
- png_byte lo_filler = (png_byte)(filler & 0xff);
-
- png_debug(1, "in png_do_read_filler");
-
- if (
- row_info->color_type == PNG_COLOR_TYPE_GRAY)
- {
- if (row_info->bit_depth == 8)
- {
- if (flags & PNG_FLAG_FILLER_AFTER)
- {
- /* This changes the data from G to GX */
- png_bytep sp = row + (png_size_t)row_width;
- png_bytep dp = sp + (png_size_t)row_width;
- for (i = 1; i < row_width; i++)
- {
- *(--dp) = lo_filler;
- *(--dp) = *(--sp);
- }
- *(--dp) = lo_filler;
- row_info->channels = 2;
- row_info->pixel_depth = 16;
- row_info->rowbytes = row_width * 2;
- }
-
- else
- {
- /* This changes the data from G to XG */
- png_bytep sp = row + (png_size_t)row_width;
- png_bytep dp = sp + (png_size_t)row_width;
- for (i = 0; i < row_width; i++)
- {
- *(--dp) = *(--sp);
- *(--dp) = lo_filler;
- }
- row_info->channels = 2;
- row_info->pixel_depth = 16;
- row_info->rowbytes = row_width * 2;
- }
- }
-
-#ifdef PNG_READ_16BIT_SUPPORTED
- else if (row_info->bit_depth == 16)
- {
- if (flags & PNG_FLAG_FILLER_AFTER)
- {
- /* This changes the data from GG to GGXX */
- png_bytep sp = row + (png_size_t)row_width * 2;
- png_bytep dp = sp + (png_size_t)row_width * 2;
- for (i = 1; i < row_width; i++)
- {
- *(--dp) = hi_filler;
- *(--dp) = lo_filler;
- *(--dp) = *(--sp);
- *(--dp) = *(--sp);
- }
- *(--dp) = hi_filler;
- *(--dp) = lo_filler;
- row_info->channels = 2;
- row_info->pixel_depth = 32;
- row_info->rowbytes = row_width * 4;
- }
-
- else
- {
- /* This changes the data from GG to XXGG */
- png_bytep sp = row + (png_size_t)row_width * 2;
- png_bytep dp = sp + (png_size_t)row_width * 2;
- for (i = 0; i < row_width; i++)
- {
- *(--dp) = *(--sp);
- *(--dp) = *(--sp);
- *(--dp) = hi_filler;
- *(--dp) = lo_filler;
- }
- row_info->channels = 2;
- row_info->pixel_depth = 32;
- row_info->rowbytes = row_width * 4;
- }
- }
-#endif
- } /* COLOR_TYPE == GRAY */
- else if (row_info->color_type == PNG_COLOR_TYPE_RGB)
- {
- if (row_info->bit_depth == 8)
- {
- if (flags & PNG_FLAG_FILLER_AFTER)
- {
- /* This changes the data from RGB to RGBX */
- png_bytep sp = row + (png_size_t)row_width * 3;
- png_bytep dp = sp + (png_size_t)row_width;
- for (i = 1; i < row_width; i++)
- {
- *(--dp) = lo_filler;
- *(--dp) = *(--sp);
- *(--dp) = *(--sp);
- *(--dp) = *(--sp);
- }
- *(--dp) = lo_filler;
- row_info->channels = 4;
- row_info->pixel_depth = 32;
- row_info->rowbytes = row_width * 4;
- }
-
- else
- {
- /* This changes the data from RGB to XRGB */
- png_bytep sp = row + (png_size_t)row_width * 3;
- png_bytep dp = sp + (png_size_t)row_width;
- for (i = 0; i < row_width; i++)
- {
- *(--dp) = *(--sp);
- *(--dp) = *(--sp);
- *(--dp) = *(--sp);
- *(--dp) = lo_filler;
- }
- row_info->channels = 4;
- row_info->pixel_depth = 32;
- row_info->rowbytes = row_width * 4;
- }
- }
-
-#ifdef PNG_READ_16BIT_SUPPORTED
- else if (row_info->bit_depth == 16)
- {
- if (flags & PNG_FLAG_FILLER_AFTER)
- {
- /* This changes the data from RRGGBB to RRGGBBXX */
- png_bytep sp = row + (png_size_t)row_width * 6;
- png_bytep dp = sp + (png_size_t)row_width * 2;
- for (i = 1; i < row_width; i++)
- {
- *(--dp) = hi_filler;
- *(--dp) = lo_filler;
- *(--dp) = *(--sp);
- *(--dp) = *(--sp);
- *(--dp) = *(--sp);
- *(--dp) = *(--sp);
- *(--dp) = *(--sp);
- *(--dp) = *(--sp);
- }
- *(--dp) = hi_filler;
- *(--dp) = lo_filler;
- row_info->channels = 4;
- row_info->pixel_depth = 64;
- row_info->rowbytes = row_width * 8;
- }
-
- else
- {
- /* This changes the data from RRGGBB to XXRRGGBB */
- png_bytep sp = row + (png_size_t)row_width * 6;
- png_bytep dp = sp + (png_size_t)row_width * 2;
- for (i = 0; i < row_width; i++)
- {
- *(--dp) = *(--sp);
- *(--dp) = *(--sp);
- *(--dp) = *(--sp);
- *(--dp) = *(--sp);
- *(--dp) = *(--sp);
- *(--dp) = *(--sp);
- *(--dp) = hi_filler;
- *(--dp) = lo_filler;
- }
-
- row_info->channels = 4;
- row_info->pixel_depth = 64;
- row_info->rowbytes = row_width * 8;
- }
- }
-#endif
- } /* COLOR_TYPE == RGB */
-}
-#endif
-
-#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
-/* Expand grayscale files to RGB, with or without alpha */
-void /* PRIVATE */
-png_do_gray_to_rgb(png_row_infop row_info, png_bytep row)
-{
- png_uint_32 i;
- png_uint_32 row_width = row_info->width;
-
- png_debug(1, "in png_do_gray_to_rgb");
-
- if (row_info->bit_depth >= 8 &&
- !(row_info->color_type & PNG_COLOR_MASK_COLOR))
- {
- if (row_info->color_type == PNG_COLOR_TYPE_GRAY)
- {
- if (row_info->bit_depth == 8)
- {
- /* This changes G to RGB */
- png_bytep sp = row + (png_size_t)row_width - 1;
- png_bytep dp = sp + (png_size_t)row_width * 2;
- for (i = 0; i < row_width; i++)
- {
- *(dp--) = *sp;
- *(dp--) = *sp;
- *(dp--) = *(sp--);
- }
- }
-
- else
- {
- /* This changes GG to RRGGBB */
- png_bytep sp = row + (png_size_t)row_width * 2 - 1;
- png_bytep dp = sp + (png_size_t)row_width * 4;
- for (i = 0; i < row_width; i++)
- {
- *(dp--) = *sp;
- *(dp--) = *(sp - 1);
- *(dp--) = *sp;
- *(dp--) = *(sp - 1);
- *(dp--) = *(sp--);
- *(dp--) = *(sp--);
- }
- }
- }
-
- else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
- {
- if (row_info->bit_depth == 8)
- {
- /* This changes GA to RGBA */
- png_bytep sp = row + (png_size_t)row_width * 2 - 1;
- png_bytep dp = sp + (png_size_t)row_width * 2;
- for (i = 0; i < row_width; i++)
- {
- *(dp--) = *(sp--);
- *(dp--) = *sp;
- *(dp--) = *sp;
- *(dp--) = *(sp--);
- }
- }
-
- else
- {
- /* This changes GGAA to RRGGBBAA */
- png_bytep sp = row + (png_size_t)row_width * 4 - 1;
- png_bytep dp = sp + (png_size_t)row_width * 4;
- for (i = 0; i < row_width; i++)
- {
- *(dp--) = *(sp--);
- *(dp--) = *(sp--);
- *(dp--) = *sp;
- *(dp--) = *(sp - 1);
- *(dp--) = *sp;
- *(dp--) = *(sp - 1);
- *(dp--) = *(sp--);
- *(dp--) = *(sp--);
- }
- }
- }
- row_info->channels = (png_byte)(row_info->channels + 2);
- row_info->color_type |= PNG_COLOR_MASK_COLOR;
- row_info->pixel_depth = (png_byte)(row_info->channels *
- row_info->bit_depth);
- row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);
- }
-}
-#endif
-
-#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
-/* Reduce RGB files to grayscale, with or without alpha
- * using the equation given in Poynton's ColorFAQ of 1998-01-04 at
- * <http://www.inforamp.net/~poynton/> (THIS LINK IS DEAD June 2008 but
- * versions dated 1998 through November 2002 have been archived at
- * http://web.archive.org/web/20000816232553/http://www.inforamp.net/
- * ~poynton/notes/colour_and_gamma/ColorFAQ.txt )
- * Charles Poynton poynton at poynton.com
- *
- * Y = 0.212671 * R + 0.715160 * G + 0.072169 * B
- *
- * which can be expressed with integers as
- *
- * Y = (6969 * R + 23434 * G + 2365 * B)/32768
- *
- * Poynton's current link (as of January 2003 through July 2011):
- * <http://www.poynton.com/notes/colour_and_gamma/>
- * has changed the numbers slightly:
- *
- * Y = 0.2126*R + 0.7152*G + 0.0722*B
- *
- * which can be expressed with integers as
- *
- * Y = (6966 * R + 23436 * G + 2366 * B)/32768
- *
- * Historically, however, libpng uses numbers derived from the ITU-R Rec 709
- * end point chromaticities and the D65 white point. Depending on the
- * precision used for the D65 white point this produces a variety of different
- * numbers, however if the four decimal place value used in ITU-R Rec 709 is
- * used (0.3127,0.3290) the Y calculation would be:
- *
- * Y = (6968 * R + 23435 * G + 2366 * B)/32768
- *
- * While this is correct the rounding results in an overflow for white, because
- * the sum of the rounded coefficients is 32769, not 32768. Consequently
- * libpng uses, instead, the closest non-overflowing approximation:
- *
- * Y = (6968 * R + 23434 * G + 2366 * B)/32768
- *
- * Starting with libpng-1.5.5, if the image being converted has a cHRM chunk
- * (including an sRGB chunk) then the chromaticities are used to calculate the
- * coefficients. See the chunk handling in pngrutil.c for more information.
- *
- * In all cases the calculation is to be done in a linear colorspace. If no
- * gamma information is available to correct the encoding of the original RGB
- * values this results in an implicit assumption that the original PNG RGB
- * values were linear.
- *
- * Other integer coefficents can be used via png_set_rgb_to_gray(). Because
- * the API takes just red and green coefficients the blue coefficient is
- * calculated to make the sum 32768. This will result in different rounding
- * to that used above.
- */
-int /* PRIVATE */
-png_do_rgb_to_gray(png_structrp png_ptr, png_row_infop row_info, png_bytep row)
-
-{
- int rgb_error = 0;
-
- png_debug(1, "in png_do_rgb_to_gray");
-
- if (!(row_info->color_type & PNG_COLOR_MASK_PALETTE) &&
- (row_info->color_type & PNG_COLOR_MASK_COLOR))
- {
- PNG_CONST png_uint_32 rc = png_ptr->rgb_to_gray_red_coeff;
- PNG_CONST png_uint_32 gc = png_ptr->rgb_to_gray_green_coeff;
- PNG_CONST png_uint_32 bc = 32768 - rc - gc;
- PNG_CONST png_uint_32 row_width = row_info->width;
- PNG_CONST int have_alpha =
- (row_info->color_type & PNG_COLOR_MASK_ALPHA) != 0;
-
- if (row_info->bit_depth == 8)
- {
-#ifdef PNG_READ_GAMMA_SUPPORTED
- /* Notice that gamma to/from 1 are not necessarily inverses (if
- * there is an overall gamma correction). Prior to 1.5.5 this code
- * checked the linearized values for equality; this doesn't match
- * the documentation, the original values must be checked.
- */
- if (png_ptr->gamma_from_1 != NULL && png_ptr->gamma_to_1 != NULL)
- {
- png_bytep sp = row;
- png_bytep dp = row;
- png_uint_32 i;
-
- for (i = 0; i < row_width; i++)
- {
- png_byte red = *(sp++);
- png_byte green = *(sp++);
- png_byte blue = *(sp++);
-
- if (red != green || red != blue)
- {
- red = png_ptr->gamma_to_1[red];
- green = png_ptr->gamma_to_1[green];
- blue = png_ptr->gamma_to_1[blue];
-
- rgb_error |= 1;
- *(dp++) = png_ptr->gamma_from_1[
- (rc*red + gc*green + bc*blue + 16384)>>15];
- }
-
- else
- {
- /* If there is no overall correction the table will not be
- * set.
- */
- if (png_ptr->gamma_table != NULL)
- red = png_ptr->gamma_table[red];
-
- *(dp++) = red;
- }
-
- if (have_alpha)
- *(dp++) = *(sp++);
- }
- }
- else
-#endif
- {
- png_bytep sp = row;
- png_bytep dp = row;
- png_uint_32 i;
-
- for (i = 0; i < row_width; i++)
- {
- png_byte red = *(sp++);
- png_byte green = *(sp++);
- png_byte blue = *(sp++);
-
- if (red != green || red != blue)
- {
- rgb_error |= 1;
- /* NOTE: this is the historical approach which simply
- * truncates the results.
- */
- *(dp++) = (png_byte)((rc*red + gc*green + bc*blue)>>15);
- }
-
- else
- *(dp++) = red;
-
- if (have_alpha)
- *(dp++) = *(sp++);
- }
- }
- }
-
- else /* RGB bit_depth == 16 */
- {
-#ifdef PNG_READ_GAMMA_SUPPORTED
- if (png_ptr->gamma_16_to_1 != NULL && png_ptr->gamma_16_from_1 != NULL)
- {
- png_bytep sp = row;
- png_bytep dp = row;
- png_uint_32 i;
-
- for (i = 0; i < row_width; i++)
- {
- png_uint_16 red, green, blue, w;
-
- red = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2;
- green = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2;
- blue = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2;
-
- if (red == green && red == blue)
- {
- if (png_ptr->gamma_16_table != NULL)
- w = png_ptr->gamma_16_table[(red&0xff)
- >> png_ptr->gamma_shift][red>>8];
-
- else
- w = red;
- }
-
- else
- {
- png_uint_16 red_1 = png_ptr->gamma_16_to_1[(red&0xff)
- >> png_ptr->gamma_shift][red>>8];
- png_uint_16 green_1 =
- png_ptr->gamma_16_to_1[(green&0xff) >>
- png_ptr->gamma_shift][green>>8];
- png_uint_16 blue_1 = png_ptr->gamma_16_to_1[(blue&0xff)
- >> png_ptr->gamma_shift][blue>>8];
- png_uint_16 gray16 = (png_uint_16)((rc*red_1 + gc*green_1
- + bc*blue_1 + 16384)>>15);
- w = png_ptr->gamma_16_from_1[(gray16&0xff) >>
- png_ptr->gamma_shift][gray16 >> 8];
- rgb_error |= 1;
- }
-
- *(dp++) = (png_byte)((w>>8) & 0xff);
- *(dp++) = (png_byte)(w & 0xff);
-
- if (have_alpha)
- {
- *(dp++) = *(sp++);
- *(dp++) = *(sp++);
- }
- }
- }
- else
-#endif
- {
- png_bytep sp = row;
- png_bytep dp = row;
- png_uint_32 i;
-
- for (i = 0; i < row_width; i++)
- {
- png_uint_16 red, green, blue, gray16;
-
- red = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2;
- green = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2;
- blue = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2;
-
- if (red != green || red != blue)
- rgb_error |= 1;
-
- /* From 1.5.5 in the 16 bit case do the accurate conversion even
- * in the 'fast' case - this is because this is where the code
- * ends up when handling linear 16 bit data.
- */
- gray16 = (png_uint_16)((rc*red + gc*green + bc*blue + 16384) >>
- 15);
- *(dp++) = (png_byte)((gray16>>8) & 0xff);
- *(dp++) = (png_byte)(gray16 & 0xff);
-
- if (have_alpha)
- {
- *(dp++) = *(sp++);
- *(dp++) = *(sp++);
- }
- }
- }
- }
-
- row_info->channels = (png_byte)(row_info->channels - 2);
- row_info->color_type = (png_byte)(row_info->color_type &
- ~PNG_COLOR_MASK_COLOR);
- row_info->pixel_depth = (png_byte)(row_info->channels *
- row_info->bit_depth);
- row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);
- }
- return rgb_error;
-}
-#endif
-#endif /* PNG_READ_TRANSFORMS_SUPPORTED */
-
-#ifdef PNG_BUILD_GRAYSCALE_PALETTE_SUPPORTED
-/* Build a grayscale palette. Palette is assumed to be 1 << bit_depth
- * large of png_color. This lets grayscale images be treated as
- * paletted. Most useful for gamma correction and simplification
- * of code. This API is not used internally.
- */
-void PNGAPI
-png_build_grayscale_palette(int bit_depth, png_colorp palette)
-{
- int num_palette;
- int color_inc;
- int i;
- int v;
-
- png_debug(1, "in png_do_build_grayscale_palette");
-
- if (palette == NULL)
- return;
-
- switch (bit_depth)
- {
- case 1:
- num_palette = 2;
- color_inc = 0xff;
- break;
-
- case 2:
- num_palette = 4;
- color_inc = 0x55;
- break;
-
- case 4:
- num_palette = 16;
- color_inc = 0x11;
- break;
-
- case 8:
- num_palette = 256;
- color_inc = 1;
- break;
-
- default:
- num_palette = 0;
- color_inc = 0;
- break;
- }
-
- for (i = 0, v = 0; i < num_palette; i++, v += color_inc)
- {
- palette[i].red = (png_byte)v;
- palette[i].green = (png_byte)v;
- palette[i].blue = (png_byte)v;
- }
-}
-#endif
-
-
-#ifdef PNG_READ_TRANSFORMS_SUPPORTED
-#if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\
- defined(PNG_READ_ALPHA_MODE_SUPPORTED)
-/* Replace any alpha or transparency with the supplied background color.
- * "background" is already in the screen gamma, while "background_1" is
- * at a gamma of 1.0. Paletted files have already been taken care of.
- */
-void /* PRIVATE */
-png_do_compose(png_row_infop row_info, png_bytep row, png_structrp png_ptr)
-{
-#ifdef PNG_READ_GAMMA_SUPPORTED
- png_const_bytep gamma_table = png_ptr->gamma_table;
- png_const_bytep gamma_from_1 = png_ptr->gamma_from_1;
- png_const_bytep gamma_to_1 = png_ptr->gamma_to_1;
- png_const_uint_16pp gamma_16 = png_ptr->gamma_16_table;
- png_const_uint_16pp gamma_16_from_1 = png_ptr->gamma_16_from_1;
- png_const_uint_16pp gamma_16_to_1 = png_ptr->gamma_16_to_1;
- int gamma_shift = png_ptr->gamma_shift;
- int optimize = (png_ptr->flags & PNG_FLAG_OPTIMIZE_ALPHA) != 0;
-#endif
-
- png_bytep sp;
- png_uint_32 i;
- png_uint_32 row_width = row_info->width;
- int shift;
-
- png_debug(1, "in png_do_compose");
-
- {
- switch (row_info->color_type)
- {
- case PNG_COLOR_TYPE_GRAY:
- {
- switch (row_info->bit_depth)
- {
- case 1:
- {
- sp = row;
- shift = 7;
- for (i = 0; i < row_width; i++)
- {
- if ((png_uint_16)((*sp >> shift) & 0x01)
- == png_ptr->trans_color.gray)
- {
- unsigned int tmp = *sp & (0x7f7f >> (7 - shift));
- tmp |= png_ptr->background.gray << shift;
- *sp = (png_byte)(tmp & 0xff);
- }
-
- if (!shift)
- {
- shift = 7;
- sp++;
- }
-
- else
- shift--;
- }
- break;
- }
-
- case 2:
- {
-#ifdef PNG_READ_GAMMA_SUPPORTED
- if (gamma_table != NULL)
- {
- sp = row;
- shift = 6;
- for (i = 0; i < row_width; i++)
- {
- if ((png_uint_16)((*sp >> shift) & 0x03)
- == png_ptr->trans_color.gray)
- {
- unsigned int tmp = *sp & (0x3f3f >> (6 - shift));
- tmp |= png_ptr->background.gray << shift;
- *sp = (png_byte)(tmp & 0xff);
- }
-
- else
- {
- unsigned int p = (*sp >> shift) & 0x03;
- unsigned int g = (gamma_table [p | (p << 2) |
- (p << 4) | (p << 6)] >> 6) & 0x03;
- unsigned int tmp = *sp & (0x3f3f >> (6 - shift));
- tmp |= g << shift;
- *sp = (png_byte)(tmp & 0xff);
- }
-
- if (!shift)
- {
- shift = 6;
- sp++;
- }
-
- else
- shift -= 2;
- }
- }
-
- else
-#endif
- {
- sp = row;
- shift = 6;
- for (i = 0; i < row_width; i++)
- {
- if ((png_uint_16)((*sp >> shift) & 0x03)
- == png_ptr->trans_color.gray)
- {
- unsigned int tmp = *sp & (0x3f3f >> (6 - shift));
- tmp |= png_ptr->background.gray << shift;
- *sp = (png_byte)(tmp & 0xff);
- }
-
- if (!shift)
- {
- shift = 6;
- sp++;
- }
-
- else
- shift -= 2;
- }
- }
- break;
- }
-
- case 4:
- {
-#ifdef PNG_READ_GAMMA_SUPPORTED
- if (gamma_table != NULL)
- {
- sp = row;
- shift = 4;
- for (i = 0; i < row_width; i++)
- {
- if ((png_uint_16)((*sp >> shift) & 0x0f)
- == png_ptr->trans_color.gray)
- {
- unsigned int tmp = *sp & (0xf0f >> (4 - shift));
- tmp |= png_ptr->background.gray << shift;
- *sp = (png_byte)(tmp & 0xff);
- }
-
- else
- {
- unsigned int p = (*sp >> shift) & 0x0f;
- unsigned int g = (gamma_table[p | (p << 4)] >> 4) &
- 0x0f;
- unsigned int tmp = *sp & (0xf0f >> (4 - shift));
- tmp |= g << shift;
- *sp = (png_byte)(tmp & 0xff);
- }
-
- if (!shift)
- {
- shift = 4;
- sp++;
- }
-
- else
- shift -= 4;
- }
- }
-
- else
-#endif
- {
- sp = row;
- shift = 4;
- for (i = 0; i < row_width; i++)
- {
- if ((png_uint_16)((*sp >> shift) & 0x0f)
- == png_ptr->trans_color.gray)
- {
- unsigned int tmp = *sp & (0xf0f >> (4 - shift));
- tmp |= png_ptr->background.gray << shift;
- *sp = (png_byte)(tmp & 0xff);
- }
-
- if (!shift)
- {
- shift = 4;
- sp++;
- }
-
- else
- shift -= 4;
- }
- }
- break;
- }
-
- case 8:
- {
-#ifdef PNG_READ_GAMMA_SUPPORTED
- if (gamma_table != NULL)
- {
- sp = row;
- for (i = 0; i < row_width; i++, sp++)
- {
- if (*sp == png_ptr->trans_color.gray)
- *sp = (png_byte)png_ptr->background.gray;
-
- else
- *sp = gamma_table[*sp];
- }
- }
- else
-#endif
- {
- sp = row;
- for (i = 0; i < row_width; i++, sp++)
- {
- if (*sp == png_ptr->trans_color.gray)
- *sp = (png_byte)png_ptr->background.gray;
- }
- }
- break;
- }
-
- case 16:
- {
-#ifdef PNG_READ_GAMMA_SUPPORTED
- if (gamma_16 != NULL)
- {
- sp = row;
- for (i = 0; i < row_width; i++, sp += 2)
- {
- png_uint_16 v;
-
- v = (png_uint_16)(((*sp) << 8) + *(sp + 1));
-
- if (v == png_ptr->trans_color.gray)
- {
- /* Background is already in screen gamma */
- *sp = (png_byte)((png_ptr->background.gray >> 8)
- & 0xff);
- *(sp + 1) = (png_byte)(png_ptr->background.gray
- & 0xff);
- }
-
- else
- {
- v = gamma_16[*(sp + 1) >> gamma_shift][*sp];
- *sp = (png_byte)((v >> 8) & 0xff);
- *(sp + 1) = (png_byte)(v & 0xff);
- }
- }
- }
- else
-#endif
- {
- sp = row;
- for (i = 0; i < row_width; i++, sp += 2)
- {
- png_uint_16 v;
-
- v = (png_uint_16)(((*sp) << 8) + *(sp + 1));
-
- if (v == png_ptr->trans_color.gray)
- {
- *sp = (png_byte)((png_ptr->background.gray >> 8)
- & 0xff);
- *(sp + 1) = (png_byte)(png_ptr->background.gray
- & 0xff);
- }
- }
- }
- break;
- }
-
- default:
- break;
- }
- break;
- }
-
- case PNG_COLOR_TYPE_RGB:
- {
- if (row_info->bit_depth == 8)
- {
-#ifdef PNG_READ_GAMMA_SUPPORTED
- if (gamma_table != NULL)
- {
- sp = row;
- for (i = 0; i < row_width; i++, sp += 3)
- {
- if (*sp == png_ptr->trans_color.red &&
- *(sp + 1) == png_ptr->trans_color.green &&
- *(sp + 2) == png_ptr->trans_color.blue)
- {
- *sp = (png_byte)png_ptr->background.red;
- *(sp + 1) = (png_byte)png_ptr->background.green;
- *(sp + 2) = (png_byte)png_ptr->background.blue;
- }
-
- else
- {
- *sp = gamma_table[*sp];
- *(sp + 1) = gamma_table[*(sp + 1)];
- *(sp + 2) = gamma_table[*(sp + 2)];
- }
- }
- }
- else
-#endif
- {
- sp = row;
- for (i = 0; i < row_width; i++, sp += 3)
- {
- if (*sp == png_ptr->trans_color.red &&
- *(sp + 1) == png_ptr->trans_color.green &&
- *(sp + 2) == png_ptr->trans_color.blue)
- {
- *sp = (png_byte)png_ptr->background.red;
- *(sp + 1) = (png_byte)png_ptr->background.green;
- *(sp + 2) = (png_byte)png_ptr->background.blue;
- }
- }
- }
- }
- else /* if (row_info->bit_depth == 16) */
- {
-#ifdef PNG_READ_GAMMA_SUPPORTED
- if (gamma_16 != NULL)
- {
- sp = row;
- for (i = 0; i < row_width; i++, sp += 6)
- {
- png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp + 1));
-
- png_uint_16 g = (png_uint_16)(((*(sp + 2)) << 8)
- + *(sp + 3));
-
- png_uint_16 b = (png_uint_16)(((*(sp + 4)) << 8)
- + *(sp + 5));
-
- if (r == png_ptr->trans_color.red &&
- g == png_ptr->trans_color.green &&
- b == png_ptr->trans_color.blue)
- {
- /* Background is already in screen gamma */
- *sp = (png_byte)((png_ptr->background.red >> 8) & 0xff);
- *(sp + 1) = (png_byte)(png_ptr->background.red & 0xff);
- *(sp + 2) = (png_byte)((png_ptr->background.green >> 8)
- & 0xff);
- *(sp + 3) = (png_byte)(png_ptr->background.green
- & 0xff);
- *(sp + 4) = (png_byte)((png_ptr->background.blue >> 8)
- & 0xff);
- *(sp + 5) = (png_byte)(png_ptr->background.blue & 0xff);
- }
-
- else
- {
- png_uint_16 v = gamma_16[*(sp + 1) >> gamma_shift][*sp];
- *sp = (png_byte)((v >> 8) & 0xff);
- *(sp + 1) = (png_byte)(v & 0xff);
-
- v = gamma_16[*(sp + 3) >> gamma_shift][*(sp + 2)];
- *(sp + 2) = (png_byte)((v >> 8) & 0xff);
- *(sp + 3) = (png_byte)(v & 0xff);
-
- v = gamma_16[*(sp + 5) >> gamma_shift][*(sp + 4)];
- *(sp + 4) = (png_byte)((v >> 8) & 0xff);
- *(sp + 5) = (png_byte)(v & 0xff);
- }
- }
- }
-
- else
-#endif
- {
- sp = row;
- for (i = 0; i < row_width; i++, sp += 6)
- {
- png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp + 1));
-
- png_uint_16 g = (png_uint_16)(((*(sp + 2)) << 8)
- + *(sp + 3));
-
- png_uint_16 b = (png_uint_16)(((*(sp + 4)) << 8)
- + *(sp + 5));
-
- if (r == png_ptr->trans_color.red &&
- g == png_ptr->trans_color.green &&
- b == png_ptr->trans_color.blue)
- {
- *sp = (png_byte)((png_ptr->background.red >> 8) & 0xff);
- *(sp + 1) = (png_byte)(png_ptr->background.red & 0xff);
- *(sp + 2) = (png_byte)((png_ptr->background.green >> 8)
- & 0xff);
- *(sp + 3) = (png_byte)(png_ptr->background.green
- & 0xff);
- *(sp + 4) = (png_byte)((png_ptr->background.blue >> 8)
- & 0xff);
- *(sp + 5) = (png_byte)(png_ptr->background.blue & 0xff);
- }
- }
- }
- }
- break;
- }
-
- case PNG_COLOR_TYPE_GRAY_ALPHA:
- {
- if (row_info->bit_depth == 8)
- {
-#ifdef PNG_READ_GAMMA_SUPPORTED
- if (gamma_to_1 != NULL && gamma_from_1 != NULL &&
- gamma_table != NULL)
- {
- sp = row;
- for (i = 0; i < row_width; i++, sp += 2)
- {
- png_uint_16 a = *(sp + 1);
-
- if (a == 0xff)
- *sp = gamma_table[*sp];
-
- else if (a == 0)
- {
- /* Background is already in screen gamma */
- *sp = (png_byte)png_ptr->background.gray;
- }
-
- else
- {
- png_byte v, w;
-
- v = gamma_to_1[*sp];
- png_composite(w, v, a, png_ptr->background_1.gray);
- if (!optimize)
- w = gamma_from_1[w];
- *sp = w;
- }
- }
- }
- else
-#endif
- {
- sp = row;
- for (i = 0; i < row_width; i++, sp += 2)
- {
- png_byte a = *(sp + 1);
-
- if (a == 0)
- *sp = (png_byte)png_ptr->background.gray;
-
- else if (a < 0xff)
- png_composite(*sp, *sp, a, png_ptr->background.gray);
- }
- }
- }
- else /* if (png_ptr->bit_depth == 16) */
- {
-#ifdef PNG_READ_GAMMA_SUPPORTED
- if (gamma_16 != NULL && gamma_16_from_1 != NULL &&
- gamma_16_to_1 != NULL)
- {
- sp = row;
- for (i = 0; i < row_width; i++, sp += 4)
- {
- png_uint_16 a = (png_uint_16)(((*(sp + 2)) << 8)
- + *(sp + 3));
-
- if (a == (png_uint_16)0xffff)
- {
- png_uint_16 v;
-
- v = gamma_16[*(sp + 1) >> gamma_shift][*sp];
- *sp = (png_byte)((v >> 8) & 0xff);
- *(sp + 1) = (png_byte)(v & 0xff);
- }
-
- else if (a == 0)
- {
- /* Background is already in screen gamma */
- *sp = (png_byte)((png_ptr->background.gray >> 8)
- & 0xff);
- *(sp + 1) = (png_byte)(png_ptr->background.gray & 0xff);
- }
-
- else
- {
- png_uint_16 g, v, w;
-
- g = gamma_16_to_1[*(sp + 1) >> gamma_shift][*sp];
- png_composite_16(v, g, a, png_ptr->background_1.gray);
- if (optimize)
- w = v;
- else
- w = gamma_16_from_1[(v&0xff) >> gamma_shift][v >> 8];
- *sp = (png_byte)((w >> 8) & 0xff);
- *(sp + 1) = (png_byte)(w & 0xff);
- }
- }
- }
- else
-#endif
- {
- sp = row;
- for (i = 0; i < row_width; i++, sp += 4)
- {
- png_uint_16 a = (png_uint_16)(((*(sp + 2)) << 8)
- + *(sp + 3));
-
- if (a == 0)
- {
- *sp = (png_byte)((png_ptr->background.gray >> 8)
- & 0xff);
- *(sp + 1) = (png_byte)(png_ptr->background.gray & 0xff);
- }
-
- else if (a < 0xffff)
- {
- png_uint_16 g, v;
-
- g = (png_uint_16)(((*sp) << 8) + *(sp + 1));
- png_composite_16(v, g, a, png_ptr->background.gray);
- *sp = (png_byte)((v >> 8) & 0xff);
- *(sp + 1) = (png_byte)(v & 0xff);
- }
- }
- }
- }
- break;
- }
-
- case PNG_COLOR_TYPE_RGB_ALPHA:
- {
- if (row_info->bit_depth == 8)
- {
-#ifdef PNG_READ_GAMMA_SUPPORTED
- if (gamma_to_1 != NULL && gamma_from_1 != NULL &&
- gamma_table != NULL)
- {
- sp = row;
- for (i = 0; i < row_width; i++, sp += 4)
- {
- png_byte a = *(sp + 3);
-
- if (a == 0xff)
- {
- *sp = gamma_table[*sp];
- *(sp + 1) = gamma_table[*(sp + 1)];
- *(sp + 2) = gamma_table[*(sp + 2)];
- }
-
- else if (a == 0)
- {
- /* Background is already in screen gamma */
- *sp = (png_byte)png_ptr->background.red;
- *(sp + 1) = (png_byte)png_ptr->background.green;
- *(sp + 2) = (png_byte)png_ptr->background.blue;
- }
-
- else
- {
- png_byte v, w;
-
- v = gamma_to_1[*sp];
- png_composite(w, v, a, png_ptr->background_1.red);
- if (!optimize) w = gamma_from_1[w];
- *sp = w;
-
- v = gamma_to_1[*(sp + 1)];
- png_composite(w, v, a, png_ptr->background_1.green);
- if (!optimize) w = gamma_from_1[w];
- *(sp + 1) = w;
-
- v = gamma_to_1[*(sp + 2)];
- png_composite(w, v, a, png_ptr->background_1.blue);
- if (!optimize) w = gamma_from_1[w];
- *(sp + 2) = w;
- }
- }
- }
- else
-#endif
- {
- sp = row;
- for (i = 0; i < row_width; i++, sp += 4)
- {
- png_byte a = *(sp + 3);
-
- if (a == 0)
- {
- *sp = (png_byte)png_ptr->background.red;
- *(sp + 1) = (png_byte)png_ptr->background.green;
- *(sp + 2) = (png_byte)png_ptr->background.blue;
- }
-
- else if (a < 0xff)
- {
- png_composite(*sp, *sp, a, png_ptr->background.red);
-
- png_composite(*(sp + 1), *(sp + 1), a,
- png_ptr->background.green);
-
- png_composite(*(sp + 2), *(sp + 2), a,
- png_ptr->background.blue);
- }
- }
- }
- }
- else /* if (row_info->bit_depth == 16) */
- {
-#ifdef PNG_READ_GAMMA_SUPPORTED
- if (gamma_16 != NULL && gamma_16_from_1 != NULL &&
- gamma_16_to_1 != NULL)
- {
- sp = row;
- for (i = 0; i < row_width; i++, sp += 8)
- {
- png_uint_16 a = (png_uint_16)(((png_uint_16)(*(sp + 6))
- << 8) + (png_uint_16)(*(sp + 7)));
-
- if (a == (png_uint_16)0xffff)
- {
- png_uint_16 v;
-
- v = gamma_16[*(sp + 1) >> gamma_shift][*sp];
- *sp = (png_byte)((v >> 8) & 0xff);
- *(sp + 1) = (png_byte)(v & 0xff);
-
- v = gamma_16[*(sp + 3) >> gamma_shift][*(sp + 2)];
- *(sp + 2) = (png_byte)((v >> 8) & 0xff);
- *(sp + 3) = (png_byte)(v & 0xff);
-
- v = gamma_16[*(sp + 5) >> gamma_shift][*(sp + 4)];
- *(sp + 4) = (png_byte)((v >> 8) & 0xff);
- *(sp + 5) = (png_byte)(v & 0xff);
- }
-
- else if (a == 0)
- {
- /* Background is already in screen gamma */
- *sp = (png_byte)((png_ptr->background.red >> 8) & 0xff);
- *(sp + 1) = (png_byte)(png_ptr->background.red & 0xff);
- *(sp + 2) = (png_byte)((png_ptr->background.green >> 8)
- & 0xff);
- *(sp + 3) = (png_byte)(png_ptr->background.green
- & 0xff);
- *(sp + 4) = (png_byte)((png_ptr->background.blue >> 8)
- & 0xff);
- *(sp + 5) = (png_byte)(png_ptr->background.blue & 0xff);
- }
-
- else
- {
- png_uint_16 v, w;
-
- v = gamma_16_to_1[*(sp + 1) >> gamma_shift][*sp];
- png_composite_16(w, v, a, png_ptr->background_1.red);
- if (!optimize)
- w = gamma_16_from_1[((w&0xff) >> gamma_shift)][w >>
- 8];
- *sp = (png_byte)((w >> 8) & 0xff);
- *(sp + 1) = (png_byte)(w & 0xff);
-
- v = gamma_16_to_1[*(sp + 3) >> gamma_shift][*(sp + 2)];
- png_composite_16(w, v, a, png_ptr->background_1.green);
- if (!optimize)
- w = gamma_16_from_1[((w&0xff) >> gamma_shift)][w >>
- 8];
-
- *(sp + 2) = (png_byte)((w >> 8) & 0xff);
- *(sp + 3) = (png_byte)(w & 0xff);
-
- v = gamma_16_to_1[*(sp + 5) >> gamma_shift][*(sp + 4)];
- png_composite_16(w, v, a, png_ptr->background_1.blue);
- if (!optimize)
- w = gamma_16_from_1[((w&0xff) >> gamma_shift)][w >>
- 8];
-
- *(sp + 4) = (png_byte)((w >> 8) & 0xff);
- *(sp + 5) = (png_byte)(w & 0xff);
- }
- }
- }
-
- else
-#endif
- {
- sp = row;
- for (i = 0; i < row_width; i++, sp += 8)
- {
- png_uint_16 a = (png_uint_16)(((png_uint_16)(*(sp + 6))
- << 8) + (png_uint_16)(*(sp + 7)));
-
- if (a == 0)
- {
- *sp = (png_byte)((png_ptr->background.red >> 8) & 0xff);
- *(sp + 1) = (png_byte)(png_ptr->background.red & 0xff);
- *(sp + 2) = (png_byte)((png_ptr->background.green >> 8)
- & 0xff);
- *(sp + 3) = (png_byte)(png_ptr->background.green
- & 0xff);
- *(sp + 4) = (png_byte)((png_ptr->background.blue >> 8)
- & 0xff);
- *(sp + 5) = (png_byte)(png_ptr->background.blue & 0xff);
- }
-
- else if (a < 0xffff)
- {
- png_uint_16 v;
-
- png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp + 1));
- png_uint_16 g = (png_uint_16)(((*(sp + 2)) << 8)
- + *(sp + 3));
- png_uint_16 b = (png_uint_16)(((*(sp + 4)) << 8)
- + *(sp + 5));
-
- png_composite_16(v, r, a, png_ptr->background.red);
- *sp = (png_byte)((v >> 8) & 0xff);
- *(sp + 1) = (png_byte)(v & 0xff);
-
- png_composite_16(v, g, a, png_ptr->background.green);
- *(sp + 2) = (png_byte)((v >> 8) & 0xff);
- *(sp + 3) = (png_byte)(v & 0xff);
-
- png_composite_16(v, b, a, png_ptr->background.blue);
- *(sp + 4) = (png_byte)((v >> 8) & 0xff);
- *(sp + 5) = (png_byte)(v & 0xff);
- }
- }
- }
- }
- break;
- }
-
- default:
- break;
- }
- }
-}
-#endif /* PNG_READ_BACKGROUND_SUPPORTED || PNG_READ_ALPHA_MODE_SUPPORTED */
-
-#ifdef PNG_READ_GAMMA_SUPPORTED
-/* Gamma correct the image, avoiding the alpha channel. Make sure
- * you do this after you deal with the transparency issue on grayscale
- * or RGB images. If your bit depth is 8, use gamma_table, if it
- * is 16, use gamma_16_table and gamma_shift. Build these with
- * build_gamma_table().
- */
-void /* PRIVATE */
-png_do_gamma(png_row_infop row_info, png_bytep row, png_structrp png_ptr)
-{
- png_const_bytep gamma_table = png_ptr->gamma_table;
- png_const_uint_16pp gamma_16_table = png_ptr->gamma_16_table;
- int gamma_shift = png_ptr->gamma_shift;
-
- png_bytep sp;
- png_uint_32 i;
- png_uint_32 row_width=row_info->width;
-
- png_debug(1, "in png_do_gamma");
-
- if (((row_info->bit_depth <= 8 && gamma_table != NULL) ||
- (row_info->bit_depth == 16 && gamma_16_table != NULL)))
- {
- switch (row_info->color_type)
- {
- case PNG_COLOR_TYPE_RGB:
- {
- if (row_info->bit_depth == 8)
- {
- sp = row;
- for (i = 0; i < row_width; i++)
- {
- *sp = gamma_table[*sp];
- sp++;
- *sp = gamma_table[*sp];
- sp++;
- *sp = gamma_table[*sp];
- sp++;
- }
- }
-
- else /* if (row_info->bit_depth == 16) */
- {
- sp = row;
- for (i = 0; i < row_width; i++)
- {
- png_uint_16 v;
-
- v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
- *sp = (png_byte)((v >> 8) & 0xff);
- *(sp + 1) = (png_byte)(v & 0xff);
- sp += 2;
-
- v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
- *sp = (png_byte)((v >> 8) & 0xff);
- *(sp + 1) = (png_byte)(v & 0xff);
- sp += 2;
-
- v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
- *sp = (png_byte)((v >> 8) & 0xff);
- *(sp + 1) = (png_byte)(v & 0xff);
- sp += 2;
- }
- }
- break;
- }
-
- case PNG_COLOR_TYPE_RGB_ALPHA:
- {
- if (row_info->bit_depth == 8)
- {
- sp = row;
- for (i = 0; i < row_width; i++)
- {
- *sp = gamma_table[*sp];
- sp++;
-
- *sp = gamma_table[*sp];
- sp++;
-
- *sp = gamma_table[*sp];
- sp++;
-
- sp++;
- }
- }
-
- else /* if (row_info->bit_depth == 16) */
- {
- sp = row;
- for (i = 0; i < row_width; i++)
- {
- png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
- *sp = (png_byte)((v >> 8) & 0xff);
- *(sp + 1) = (png_byte)(v & 0xff);
- sp += 2;
-
- v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
- *sp = (png_byte)((v >> 8) & 0xff);
- *(sp + 1) = (png_byte)(v & 0xff);
- sp += 2;
-
- v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
- *sp = (png_byte)((v >> 8) & 0xff);
- *(sp + 1) = (png_byte)(v & 0xff);
- sp += 4;
- }
- }
- break;
- }
-
- case PNG_COLOR_TYPE_GRAY_ALPHA:
- {
- if (row_info->bit_depth == 8)
- {
- sp = row;
- for (i = 0; i < row_width; i++)
- {
- *sp = gamma_table[*sp];
- sp += 2;
- }
- }
-
- else /* if (row_info->bit_depth == 16) */
- {
- sp = row;
- for (i = 0; i < row_width; i++)
- {
- png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
- *sp = (png_byte)((v >> 8) & 0xff);
- *(sp + 1) = (png_byte)(v & 0xff);
- sp += 4;
- }
- }
- break;
- }
-
- case PNG_COLOR_TYPE_GRAY:
- {
- if (row_info->bit_depth == 2)
- {
- sp = row;
- for (i = 0; i < row_width; i += 4)
- {
- int a = *sp & 0xc0;
- int b = *sp & 0x30;
- int c = *sp & 0x0c;
- int d = *sp & 0x03;
-
- *sp = (png_byte)(
- ((((int)gamma_table[a|(a>>2)|(a>>4)|(a>>6)]) ) & 0xc0)|
- ((((int)gamma_table[(b<<2)|b|(b>>2)|(b>>4)])>>2) & 0x30)|
- ((((int)gamma_table[(c<<4)|(c<<2)|c|(c>>2)])>>4) & 0x0c)|
- ((((int)gamma_table[(d<<6)|(d<<4)|(d<<2)|d])>>6) ));
- sp++;
- }
- }
-
- if (row_info->bit_depth == 4)
- {
- sp = row;
- for (i = 0; i < row_width; i += 2)
- {
- int msb = *sp & 0xf0;
- int lsb = *sp & 0x0f;
-
- *sp = (png_byte)((((int)gamma_table[msb | (msb >> 4)]) & 0xf0)
- | (((int)gamma_table[(lsb << 4) | lsb]) >> 4));
- sp++;
- }
- }
-
- else if (row_info->bit_depth == 8)
- {
- sp = row;
- for (i = 0; i < row_width; i++)
- {
- *sp = gamma_table[*sp];
- sp++;
- }
- }
-
- else if (row_info->bit_depth == 16)
- {
- sp = row;
- for (i = 0; i < row_width; i++)
- {
- png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
- *sp = (png_byte)((v >> 8) & 0xff);
- *(sp + 1) = (png_byte)(v & 0xff);
- sp += 2;
- }
- }
- break;
- }
-
- default:
- break;
- }
- }
-}
-#endif
-
-#ifdef PNG_READ_ALPHA_MODE_SUPPORTED
-/* Encode the alpha channel to the output gamma (the input channel is always
- * linear.) Called only with color types that have an alpha channel. Needs the
- * from_1 tables.
- */
-void /* PRIVATE */
-png_do_encode_alpha(png_row_infop row_info, png_bytep row, png_structrp png_ptr)
-{
- png_uint_32 row_width = row_info->width;
-
- png_debug(1, "in png_do_encode_alpha");
-
- if (row_info->color_type & PNG_COLOR_MASK_ALPHA)
- {
- if (row_info->bit_depth == 8)
- {
- PNG_CONST png_bytep table = png_ptr->gamma_from_1;
-
- if (table != NULL)
- {
- PNG_CONST int step =
- (row_info->color_type & PNG_COLOR_MASK_COLOR) ? 4 : 2;
-
- /* The alpha channel is the last component: */
- row += step - 1;
-
- for (; row_width > 0; --row_width, row += step)
- *row = table[*row];
-
- return;
- }
- }
-
- else if (row_info->bit_depth == 16)
- {
- PNG_CONST png_uint_16pp table = png_ptr->gamma_16_from_1;
- PNG_CONST int gamma_shift = png_ptr->gamma_shift;
-
- if (table != NULL)
- {
- PNG_CONST int step =
- (row_info->color_type & PNG_COLOR_MASK_COLOR) ? 8 : 4;
-
- /* The alpha channel is the last component: */
- row += step - 2;
-
- for (; row_width > 0; --row_width, row += step)
- {
- png_uint_16 v;
-
- v = table[*(row + 1) >> gamma_shift][*row];
- *row = (png_byte)((v >> 8) & 0xff);
- *(row + 1) = (png_byte)(v & 0xff);
- }
-
- return;
- }
- }
- }
-
- /* Only get to here if called with a weird row_info; no harm has been done,
- * so just issue a warning.
- */
- png_warning(png_ptr, "png_do_encode_alpha: unexpected call");
-}
-#endif
-
-#ifdef PNG_READ_EXPAND_SUPPORTED
-/* Expands a palette row to an RGB or RGBA row depending
- * upon whether you supply trans and num_trans.
- */
-void /* PRIVATE */
-png_do_expand_palette(png_row_infop row_info, png_bytep row,
- png_const_colorp palette, png_const_bytep trans_alpha, int num_trans)
-{
- int shift, value;
- png_bytep sp, dp;
- png_uint_32 i;
- png_uint_32 row_width=row_info->width;
-
- png_debug(1, "in png_do_expand_palette");
-
- if (row_info->color_type == PNG_COLOR_TYPE_PALETTE)
- {
- if (row_info->bit_depth < 8)
- {
- switch (row_info->bit_depth)
- {
- case 1:
- {
- sp = row + (png_size_t)((row_width - 1) >> 3);
- dp = row + (png_size_t)row_width - 1;
- shift = 7 - (int)((row_width + 7) & 0x07);
- for (i = 0; i < row_width; i++)
- {
- if ((*sp >> shift) & 0x01)
- *dp = 1;
-
- else
- *dp = 0;
-
- if (shift == 7)
- {
- shift = 0;
- sp--;
- }
-
- else
- shift++;
-
- dp--;
- }
- break;
- }
-
- case 2:
- {
- sp = row + (png_size_t)((row_width - 1) >> 2);
- dp = row + (png_size_t)row_width - 1;
- shift = (int)((3 - ((row_width + 3) & 0x03)) << 1);
- for (i = 0; i < row_width; i++)
- {
- value = (*sp >> shift) & 0x03;
- *dp = (png_byte)value;
- if (shift == 6)
- {
- shift = 0;
- sp--;
- }
-
- else
- shift += 2;
-
- dp--;
- }
- break;
- }
-
- case 4:
- {
- sp = row + (png_size_t)((row_width - 1) >> 1);
- dp = row + (png_size_t)row_width - 1;
- shift = (int)((row_width & 0x01) << 2);
- for (i = 0; i < row_width; i++)
- {
- value = (*sp >> shift) & 0x0f;
- *dp = (png_byte)value;
- if (shift == 4)
- {
- shift = 0;
- sp--;
- }
-
- else
- shift += 4;
-
- dp--;
- }
- break;
- }
-
- default:
- break;
- }
- row_info->bit_depth = 8;
- row_info->pixel_depth = 8;
- row_info->rowbytes = row_width;
- }
-
- if (row_info->bit_depth == 8)
- {
- {
- if (num_trans > 0)
- {
- sp = row + (png_size_t)row_width - 1;
- dp = row + (png_size_t)(row_width << 2) - 1;
-
- for (i = 0; i < row_width; i++)
- {
- if ((int)(*sp) >= num_trans)
- *dp-- = 0xff;
-
- else
- *dp-- = trans_alpha[*sp];
-
- *dp-- = palette[*sp].blue;
- *dp-- = palette[*sp].green;
- *dp-- = palette[*sp].red;
- sp--;
- }
- row_info->bit_depth = 8;
- row_info->pixel_depth = 32;
- row_info->rowbytes = row_width * 4;
- row_info->color_type = 6;
- row_info->channels = 4;
- }
-
- else
- {
- sp = row + (png_size_t)row_width - 1;
- dp = row + (png_size_t)(row_width * 3) - 1;
-
- for (i = 0; i < row_width; i++)
- {
- *dp-- = palette[*sp].blue;
- *dp-- = palette[*sp].green;
- *dp-- = palette[*sp].red;
- sp--;
- }
-
- row_info->bit_depth = 8;
- row_info->pixel_depth = 24;
- row_info->rowbytes = row_width * 3;
- row_info->color_type = 2;
- row_info->channels = 3;
- }
- }
- }
- }
-}
-
-/* If the bit depth < 8, it is expanded to 8. Also, if the already
- * expanded transparency value is supplied, an alpha channel is built.
- */
-void /* PRIVATE */
-png_do_expand(png_row_infop row_info, png_bytep row,
- png_const_color_16p trans_color)
-{
- int shift, value;
- png_bytep sp, dp;
- png_uint_32 i;
- png_uint_32 row_width=row_info->width;
-
- png_debug(1, "in png_do_expand");
-
- {
- if (row_info->color_type == PNG_COLOR_TYPE_GRAY)
- {
- unsigned int gray = trans_color ? trans_color->gray : 0;
-
- if (row_info->bit_depth < 8)
- {
- switch (row_info->bit_depth)
- {
- case 1:
- {
- gray = (gray & 0x01) * 0xff;
- sp = row + (png_size_t)((row_width - 1) >> 3);
- dp = row + (png_size_t)row_width - 1;
- shift = 7 - (int)((row_width + 7) & 0x07);
- for (i = 0; i < row_width; i++)
- {
- if ((*sp >> shift) & 0x01)
- *dp = 0xff;
-
- else
- *dp = 0;
-
- if (shift == 7)
- {
- shift = 0;
- sp--;
- }
-
- else
- shift++;
-
- dp--;
- }
- break;
- }
-
- case 2:
- {
- gray = (gray & 0x03) * 0x55;
- sp = row + (png_size_t)((row_width - 1) >> 2);
- dp = row + (png_size_t)row_width - 1;
- shift = (int)((3 - ((row_width + 3) & 0x03)) << 1);
- for (i = 0; i < row_width; i++)
- {
- value = (*sp >> shift) & 0x03;
- *dp = (png_byte)(value | (value << 2) | (value << 4) |
- (value << 6));
- if (shift == 6)
- {
- shift = 0;
- sp--;
- }
-
- else
- shift += 2;
-
- dp--;
- }
- break;
- }
-
- case 4:
- {
- gray = (gray & 0x0f) * 0x11;
- sp = row + (png_size_t)((row_width - 1) >> 1);
- dp = row + (png_size_t)row_width - 1;
- shift = (int)((1 - ((row_width + 1) & 0x01)) << 2);
- for (i = 0; i < row_width; i++)
- {
- value = (*sp >> shift) & 0x0f;
- *dp = (png_byte)(value | (value << 4));
- if (shift == 4)
- {
- shift = 0;
- sp--;
- }
-
- else
- shift = 4;
-
- dp--;
- }
- break;
- }
-
- default:
- break;
- }
-
- row_info->bit_depth = 8;
- row_info->pixel_depth = 8;
- row_info->rowbytes = row_width;
- }
-
- if (trans_color != NULL)
- {
- if (row_info->bit_depth == 8)
- {
- gray = gray & 0xff;
- sp = row + (png_size_t)row_width - 1;
- dp = row + (png_size_t)(row_width << 1) - 1;
-
- for (i = 0; i < row_width; i++)
- {
- if (*sp == gray)
- *dp-- = 0;
-
- else
- *dp-- = 0xff;
-
- *dp-- = *sp--;
- }
- }
-
- else if (row_info->bit_depth == 16)
- {
- unsigned int gray_high = (gray >> 8) & 0xff;
- unsigned int gray_low = gray & 0xff;
- sp = row + row_info->rowbytes - 1;
- dp = row + (row_info->rowbytes << 1) - 1;
- for (i = 0; i < row_width; i++)
- {
- if (*(sp - 1) == gray_high && *(sp) == gray_low)
- {
- *dp-- = 0;
- *dp-- = 0;
- }
-
- else
- {
- *dp-- = 0xff;
- *dp-- = 0xff;
- }
-
- *dp-- = *sp--;
- *dp-- = *sp--;
- }
- }
-
- row_info->color_type = PNG_COLOR_TYPE_GRAY_ALPHA;
- row_info->channels = 2;
- row_info->pixel_depth = (png_byte)(row_info->bit_depth << 1);
- row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth,
- row_width);
- }
- }
- else if (row_info->color_type == PNG_COLOR_TYPE_RGB && trans_color)
- {
- if (row_info->bit_depth == 8)
- {
- png_byte red = (png_byte)(trans_color->red & 0xff);
- png_byte green = (png_byte)(trans_color->green & 0xff);
- png_byte blue = (png_byte)(trans_color->blue & 0xff);
- sp = row + (png_size_t)row_info->rowbytes - 1;
- dp = row + (png_size_t)(row_width << 2) - 1;
- for (i = 0; i < row_width; i++)
- {
- if (*(sp - 2) == red && *(sp - 1) == green && *(sp) == blue)
- *dp-- = 0;
-
- else
- *dp-- = 0xff;
-
- *dp-- = *sp--;
- *dp-- = *sp--;
- *dp-- = *sp--;
- }
- }
- else if (row_info->bit_depth == 16)
- {
- png_byte red_high = (png_byte)((trans_color->red >> 8) & 0xff);
- png_byte green_high = (png_byte)((trans_color->green >> 8) & 0xff);
- png_byte blue_high = (png_byte)((trans_color->blue >> 8) & 0xff);
- png_byte red_low = (png_byte)(trans_color->red & 0xff);
- png_byte green_low = (png_byte)(trans_color->green & 0xff);
- png_byte blue_low = (png_byte)(trans_color->blue & 0xff);
- sp = row + row_info->rowbytes - 1;
- dp = row + (png_size_t)(row_width << 3) - 1;
- for (i = 0; i < row_width; i++)
- {
- if (*(sp - 5) == red_high &&
- *(sp - 4) == red_low &&
- *(sp - 3) == green_high &&
- *(sp - 2) == green_low &&
- *(sp - 1) == blue_high &&
- *(sp ) == blue_low)
- {
- *dp-- = 0;
- *dp-- = 0;
- }
-
- else
- {
- *dp-- = 0xff;
- *dp-- = 0xff;
- }
-
- *dp-- = *sp--;
- *dp-- = *sp--;
- *dp-- = *sp--;
- *dp-- = *sp--;
- *dp-- = *sp--;
- *dp-- = *sp--;
- }
- }
- row_info->color_type = PNG_COLOR_TYPE_RGB_ALPHA;
- row_info->channels = 4;
- row_info->pixel_depth = (png_byte)(row_info->bit_depth << 2);
- row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);
- }
- }
-}
-#endif
-
-#ifdef PNG_READ_EXPAND_16_SUPPORTED
-/* If the bit depth is 8 and the color type is not a palette type expand the
- * whole row to 16 bits. Has no effect otherwise.
- */
-void /* PRIVATE */
-png_do_expand_16(png_row_infop row_info, png_bytep row)
-{
- if (row_info->bit_depth == 8 &&
- row_info->color_type != PNG_COLOR_TYPE_PALETTE)
- {
- /* The row have a sequence of bytes containing [0..255] and we need
- * to turn it into another row containing [0..65535], to do this we
- * calculate:
- *
- * (input / 255) * 65535
- *
- * Which happens to be exactly input * 257 and this can be achieved
- * simply by byte replication in place (copying backwards).
- */
- png_byte *sp = row + row_info->rowbytes; /* source, last byte + 1 */
- png_byte *dp = sp + row_info->rowbytes; /* destination, end + 1 */
- while (dp > sp)
- dp[-2] = dp[-1] = *--sp, dp -= 2;
-
- row_info->rowbytes *= 2;
- row_info->bit_depth = 16;
- row_info->pixel_depth = (png_byte)(row_info->channels * 16);
- }
-}
-#endif
-
-#ifdef PNG_READ_QUANTIZE_SUPPORTED
-void /* PRIVATE */
-png_do_quantize(png_row_infop row_info, png_bytep row,
- png_const_bytep palette_lookup, png_const_bytep quantize_lookup)
-{
- png_bytep sp, dp;
- png_uint_32 i;
- png_uint_32 row_width=row_info->width;
-
- png_debug(1, "in png_do_quantize");
-
- if (row_info->bit_depth == 8)
- {
- if (row_info->color_type == PNG_COLOR_TYPE_RGB && palette_lookup)
- {
- int r, g, b, p;
- sp = row;
- dp = row;
- for (i = 0; i < row_width; i++)
- {
- r = *sp++;
- g = *sp++;
- b = *sp++;
-
- /* This looks real messy, but the compiler will reduce
- * it down to a reasonable formula. For example, with
- * 5 bits per color, we get:
- * p = (((r >> 3) & 0x1f) << 10) |
- * (((g >> 3) & 0x1f) << 5) |
- * ((b >> 3) & 0x1f);
- */
- p = (((r >> (8 - PNG_QUANTIZE_RED_BITS)) &
- ((1 << PNG_QUANTIZE_RED_BITS) - 1)) <<
- (PNG_QUANTIZE_GREEN_BITS + PNG_QUANTIZE_BLUE_BITS)) |
- (((g >> (8 - PNG_QUANTIZE_GREEN_BITS)) &
- ((1 << PNG_QUANTIZE_GREEN_BITS) - 1)) <<
- (PNG_QUANTIZE_BLUE_BITS)) |
- ((b >> (8 - PNG_QUANTIZE_BLUE_BITS)) &
- ((1 << PNG_QUANTIZE_BLUE_BITS) - 1));
-
- *dp++ = palette_lookup[p];
- }
-
- row_info->color_type = PNG_COLOR_TYPE_PALETTE;
- row_info->channels = 1;
- row_info->pixel_depth = row_info->bit_depth;
- row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);
- }
-
- else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA &&
- palette_lookup != NULL)
- {
- int r, g, b, p;
- sp = row;
- dp = row;
- for (i = 0; i < row_width; i++)
- {
- r = *sp++;
- g = *sp++;
- b = *sp++;
- sp++;
-
- p = (((r >> (8 - PNG_QUANTIZE_RED_BITS)) &
- ((1 << PNG_QUANTIZE_RED_BITS) - 1)) <<
- (PNG_QUANTIZE_GREEN_BITS + PNG_QUANTIZE_BLUE_BITS)) |
- (((g >> (8 - PNG_QUANTIZE_GREEN_BITS)) &
- ((1 << PNG_QUANTIZE_GREEN_BITS) - 1)) <<
- (PNG_QUANTIZE_BLUE_BITS)) |
- ((b >> (8 - PNG_QUANTIZE_BLUE_BITS)) &
- ((1 << PNG_QUANTIZE_BLUE_BITS) - 1));
-
- *dp++ = palette_lookup[p];
- }
-
- row_info->color_type = PNG_COLOR_TYPE_PALETTE;
- row_info->channels = 1;
- row_info->pixel_depth = row_info->bit_depth;
- row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);
- }
-
- else if (row_info->color_type == PNG_COLOR_TYPE_PALETTE &&
- quantize_lookup)
- {
- sp = row;
-
- for (i = 0; i < row_width; i++, sp++)
- {
- *sp = quantize_lookup[*sp];
- }
- }
- }
-}
-#endif /* PNG_READ_QUANTIZE_SUPPORTED */
-#endif /* PNG_READ_TRANSFORMS_SUPPORTED */
-
-#ifdef PNG_MNG_FEATURES_SUPPORTED
-/* Undoes intrapixel differencing */
-void /* PRIVATE */
-png_do_read_intrapixel(png_row_infop row_info, png_bytep row)
-{
- png_debug(1, "in png_do_read_intrapixel");
-
- if (
- (row_info->color_type & PNG_COLOR_MASK_COLOR))
- {
- int bytes_per_pixel;
- png_uint_32 row_width = row_info->width;
-
- if (row_info->bit_depth == 8)
- {
- png_bytep rp;
- png_uint_32 i;
-
- if (row_info->color_type == PNG_COLOR_TYPE_RGB)
- bytes_per_pixel = 3;
-
- else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
- bytes_per_pixel = 4;
-
- else
- return;
-
- for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel)
- {
- *(rp) = (png_byte)((256 + *rp + *(rp + 1)) & 0xff);
- *(rp+2) = (png_byte)((256 + *(rp + 2) + *(rp + 1)) & 0xff);
- }
- }
- else if (row_info->bit_depth == 16)
- {
- png_bytep rp;
- png_uint_32 i;
-
- if (row_info->color_type == PNG_COLOR_TYPE_RGB)
- bytes_per_pixel = 6;
-
- else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
- bytes_per_pixel = 8;
-
- else
- return;
-
- for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel)
- {
- png_uint_32 s0 = (*(rp ) << 8) | *(rp + 1);
- png_uint_32 s1 = (*(rp + 2) << 8) | *(rp + 3);
- png_uint_32 s2 = (*(rp + 4) << 8) | *(rp + 5);
- png_uint_32 red = (s0 + s1 + 65536) & 0xffff;
- png_uint_32 blue = (s2 + s1 + 65536) & 0xffff;
- *(rp ) = (png_byte)((red >> 8) & 0xff);
- *(rp + 1) = (png_byte)(red & 0xff);
- *(rp + 4) = (png_byte)((blue >> 8) & 0xff);
- *(rp + 5) = (png_byte)(blue & 0xff);
- }
- }
- }
-}
-#endif /* PNG_MNG_FEATURES_SUPPORTED */
-#endif /* PNG_READ_SUPPORTED */
+
+/* pngrtran.c - transforms the data in a row for PNG readers
+ *
+ * Last changed in libpng 1.6.19 [November 12, 2015]
+ * Copyright (c) 1998-2015 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ * This file contains functions optionally called by an application
+ * in order to tell libpng how to handle data when reading a PNG.
+ * Transformations that are used in both reading and writing are
+ * in pngtrans.c.
+ */
+
+#include "pngpriv.h"
+
+#ifdef PNG_READ_SUPPORTED
+
+/* Set the action on getting a CRC error for an ancillary or critical chunk. */
+void PNGAPI
+png_set_crc_action(png_structrp png_ptr, int crit_action, int ancil_action)
+{
+ png_debug(1, "in png_set_crc_action");
+
+ if (png_ptr == NULL)
+ return;
+
+ /* Tell libpng how we react to CRC errors in critical chunks */
+ switch (crit_action)
+ {
+ case PNG_CRC_NO_CHANGE: /* Leave setting as is */
+ break;
+
+ case PNG_CRC_WARN_USE: /* Warn/use data */
+ png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK;
+ png_ptr->flags |= PNG_FLAG_CRC_CRITICAL_USE;
+ break;
+
+ case PNG_CRC_QUIET_USE: /* Quiet/use data */
+ png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK;
+ png_ptr->flags |= PNG_FLAG_CRC_CRITICAL_USE |
+ PNG_FLAG_CRC_CRITICAL_IGNORE;
+ break;
+
+ case PNG_CRC_WARN_DISCARD: /* Not a valid action for critical data */
+ png_warning(png_ptr,
+ "Can't discard critical data on CRC error");
+ case PNG_CRC_ERROR_QUIT: /* Error/quit */
+
+ case PNG_CRC_DEFAULT:
+ default:
+ png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK;
+ break;
+ }
+
+ /* Tell libpng how we react to CRC errors in ancillary chunks */
+ switch (ancil_action)
+ {
+ case PNG_CRC_NO_CHANGE: /* Leave setting as is */
+ break;
+
+ case PNG_CRC_WARN_USE: /* Warn/use data */
+ png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK;
+ png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_USE;
+ break;
+
+ case PNG_CRC_QUIET_USE: /* Quiet/use data */
+ png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK;
+ png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_USE |
+ PNG_FLAG_CRC_ANCILLARY_NOWARN;
+ break;
+
+ case PNG_CRC_ERROR_QUIT: /* Error/quit */
+ png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK;
+ png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_NOWARN;
+ break;
+
+ case PNG_CRC_WARN_DISCARD: /* Warn/discard data */
+
+ case PNG_CRC_DEFAULT:
+ default:
+ png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK;
+ break;
+ }
+}
+
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
+/* Is it OK to set a transformation now? Only if png_start_read_image or
+ * png_read_update_info have not been called. It is not necessary for the IHDR
+ * to have been read in all cases; the need_IHDR parameter allows for this
+ * check too.
+ */
+static int
+png_rtran_ok(png_structrp png_ptr, int need_IHDR)
+{
+ if (png_ptr != NULL)
+ {
+ if ((png_ptr->flags & PNG_FLAG_ROW_INIT) != 0)
+ png_app_error(png_ptr,
+ "invalid after png_start_read_image or png_read_update_info");
+
+ else if (need_IHDR && (png_ptr->mode & PNG_HAVE_IHDR) == 0)
+ png_app_error(png_ptr, "invalid before the PNG header has been read");
+
+ else
+ {
+ /* Turn on failure to initialize correctly for all transforms. */
+ png_ptr->flags |= PNG_FLAG_DETECT_UNINITIALIZED;
+
+ return 1; /* Ok */
+ }
+ }
+
+ return 0; /* no png_error possible! */
+}
+#endif
+
+#ifdef PNG_READ_BACKGROUND_SUPPORTED
+/* Handle alpha and tRNS via a background color */
+void PNGFAPI
+png_set_background_fixed(png_structrp png_ptr,
+ png_const_color_16p background_color, int background_gamma_code,
+ int need_expand, png_fixed_point background_gamma)
+{
+ png_debug(1, "in png_set_background_fixed");
+
+ if (png_rtran_ok(png_ptr, 0) == 0 || background_color == NULL)
+ return;
+
+ if (background_gamma_code == PNG_BACKGROUND_GAMMA_UNKNOWN)
+ {
+ png_warning(png_ptr, "Application must supply a known background gamma");
+ return;
+ }
+
+ png_ptr->transformations |= PNG_COMPOSE | PNG_STRIP_ALPHA;
+ png_ptr->transformations &= ~PNG_ENCODE_ALPHA;
+ png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA;
+
+ png_ptr->background = *background_color;
+ png_ptr->background_gamma = background_gamma;
+ png_ptr->background_gamma_type = (png_byte)(background_gamma_code);
+ if (need_expand != 0)
+ png_ptr->transformations |= PNG_BACKGROUND_EXPAND;
+ else
+ png_ptr->transformations &= ~PNG_BACKGROUND_EXPAND;
+}
+
+# ifdef PNG_FLOATING_POINT_SUPPORTED
+void PNGAPI
+png_set_background(png_structrp png_ptr,
+ png_const_color_16p background_color, int background_gamma_code,
+ int need_expand, double background_gamma)
+{
+ png_set_background_fixed(png_ptr, background_color, background_gamma_code,
+ need_expand, png_fixed(png_ptr, background_gamma, "png_set_background"));
+}
+# endif /* FLOATING_POINT */
+#endif /* READ_BACKGROUND */
+
+/* Scale 16-bit depth files to 8-bit depth. If both of these are set then the
+ * one that pngrtran does first (scale) happens. This is necessary to allow the
+ * TRANSFORM and API behavior to be somewhat consistent, and it's simpler.
+ */
+#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
+void PNGAPI
+png_set_scale_16(png_structrp png_ptr)
+{
+ png_debug(1, "in png_set_scale_16");
+
+ if (png_rtran_ok(png_ptr, 0) == 0)
+ return;
+
+ png_ptr->transformations |= PNG_SCALE_16_TO_8;
+}
+#endif
+
+#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
+/* Chop 16-bit depth files to 8-bit depth */
+void PNGAPI
+png_set_strip_16(png_structrp png_ptr)
+{
+ png_debug(1, "in png_set_strip_16");
+
+ if (png_rtran_ok(png_ptr, 0) == 0)
+ return;
+
+ png_ptr->transformations |= PNG_16_TO_8;
+}
+#endif
+
+#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
+void PNGAPI
+png_set_strip_alpha(png_structrp png_ptr)
+{
+ png_debug(1, "in png_set_strip_alpha");
+
+ if (png_rtran_ok(png_ptr, 0) == 0)
+ return;
+
+ png_ptr->transformations |= PNG_STRIP_ALPHA;
+}
+#endif
+
+#if defined(PNG_READ_ALPHA_MODE_SUPPORTED) || defined(PNG_READ_GAMMA_SUPPORTED)
+static png_fixed_point
+translate_gamma_flags(png_structrp png_ptr, png_fixed_point output_gamma,
+ int is_screen)
+{
+ /* Check for flag values. The main reason for having the old Mac value as a
+ * flag is that it is pretty near impossible to work out what the correct
+ * value is from Apple documentation - a working Mac system is needed to
+ * discover the value!
+ */
+ if (output_gamma == PNG_DEFAULT_sRGB ||
+ output_gamma == PNG_FP_1 / PNG_DEFAULT_sRGB)
+ {
+ /* If there is no sRGB support this just sets the gamma to the standard
+ * sRGB value. (This is a side effect of using this function!)
+ */
+# ifdef PNG_READ_sRGB_SUPPORTED
+ png_ptr->flags |= PNG_FLAG_ASSUME_sRGB;
+# else
+ PNG_UNUSED(png_ptr)
+# endif
+ if (is_screen != 0)
+ output_gamma = PNG_GAMMA_sRGB;
+ else
+ output_gamma = PNG_GAMMA_sRGB_INVERSE;
+ }
+
+ else if (output_gamma == PNG_GAMMA_MAC_18 ||
+ output_gamma == PNG_FP_1 / PNG_GAMMA_MAC_18)
+ {
+ if (is_screen != 0)
+ output_gamma = PNG_GAMMA_MAC_OLD;
+ else
+ output_gamma = PNG_GAMMA_MAC_INVERSE;
+ }
+
+ return output_gamma;
+}
+
+# ifdef PNG_FLOATING_POINT_SUPPORTED
+static png_fixed_point
+convert_gamma_value(png_structrp png_ptr, double output_gamma)
+{
+ /* The following silently ignores cases where fixed point (times 100,000)
+ * gamma values are passed to the floating point API. This is safe and it
+ * means the fixed point constants work just fine with the floating point
+ * API. The alternative would just lead to undetected errors and spurious
+ * bug reports. Negative values fail inside the _fixed API unless they
+ * correspond to the flag values.
+ */
+ if (output_gamma > 0 && output_gamma < 128)
+ output_gamma *= PNG_FP_1;
+
+ /* This preserves -1 and -2 exactly: */
+ output_gamma = floor(output_gamma + .5);
+
+ if (output_gamma > PNG_FP_MAX || output_gamma < PNG_FP_MIN)
+ png_fixed_error(png_ptr, "gamma value");
+
+ return (png_fixed_point)output_gamma;
+}
+# endif
+#endif /* READ_ALPHA_MODE || READ_GAMMA */
+
+#ifdef PNG_READ_ALPHA_MODE_SUPPORTED
+void PNGFAPI
+png_set_alpha_mode_fixed(png_structrp png_ptr, int mode,
+ png_fixed_point output_gamma)
+{
+ int compose = 0;
+ png_fixed_point file_gamma;
+
+ png_debug(1, "in png_set_alpha_mode");
+
+ if (png_rtran_ok(png_ptr, 0) == 0)
+ return;
+
+ output_gamma = translate_gamma_flags(png_ptr, output_gamma, 1/*screen*/);
+
+ /* Validate the value to ensure it is in a reasonable range. The value
+ * is expected to be 1 or greater, but this range test allows for some
+ * viewing correction values. The intent is to weed out users of this API
+ * who use the inverse of the gamma value accidentally! Since some of these
+ * values are reasonable this may have to be changed.
+ */
+ if (output_gamma < 70000 || output_gamma > 300000)
+ png_error(png_ptr, "output gamma out of expected range");
+
+ /* The default file gamma is the inverse of the output gamma; the output
+ * gamma may be changed below so get the file value first:
+ */
+ file_gamma = png_reciprocal(output_gamma);
+
+ /* There are really 8 possibilities here, composed of any combination
+ * of:
+ *
+ * premultiply the color channels
+ * do not encode non-opaque pixels
+ * encode the alpha as well as the color channels
+ *
+ * The differences disappear if the input/output ('screen') gamma is 1.0,
+ * because then the encoding is a no-op and there is only the choice of
+ * premultiplying the color channels or not.
+ *
+ * png_set_alpha_mode and png_set_background interact because both use
+ * png_compose to do the work. Calling both is only useful when
+ * png_set_alpha_mode is used to set the default mode - PNG_ALPHA_PNG - along
+ * with a default gamma value. Otherwise PNG_COMPOSE must not be set.
+ */
+ switch (mode)
+ {
+ case PNG_ALPHA_PNG: /* default: png standard */
+ /* No compose, but it may be set by png_set_background! */
+ png_ptr->transformations &= ~PNG_ENCODE_ALPHA;
+ png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA;
+ break;
+
+ case PNG_ALPHA_ASSOCIATED: /* color channels premultiplied */
+ compose = 1;
+ png_ptr->transformations &= ~PNG_ENCODE_ALPHA;
+ png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA;
+ /* The output is linear: */
+ output_gamma = PNG_FP_1;
+ break;
+
+ case PNG_ALPHA_OPTIMIZED: /* associated, non-opaque pixels linear */
+ compose = 1;
+ png_ptr->transformations &= ~PNG_ENCODE_ALPHA;
+ png_ptr->flags |= PNG_FLAG_OPTIMIZE_ALPHA;
+ /* output_gamma records the encoding of opaque pixels! */
+ break;
+
+ case PNG_ALPHA_BROKEN: /* associated, non-linear, alpha encoded */
+ compose = 1;
+ png_ptr->transformations |= PNG_ENCODE_ALPHA;
+ png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA;
+ break;
+
+ default:
+ png_error(png_ptr, "invalid alpha mode");
+ }
+
+ /* Only set the default gamma if the file gamma has not been set (this has
+ * the side effect that the gamma in a second call to png_set_alpha_mode will
+ * be ignored.)
+ */
+ if (png_ptr->colorspace.gamma == 0)
+ {
+ png_ptr->colorspace.gamma = file_gamma;
+ png_ptr->colorspace.flags |= PNG_COLORSPACE_HAVE_GAMMA;
+ }
+
+ /* But always set the output gamma: */
+ png_ptr->screen_gamma = output_gamma;
+
+ /* Finally, if pre-multiplying, set the background fields to achieve the
+ * desired result.
+ */
+ if (compose != 0)
+ {
+ /* And obtain alpha pre-multiplication by composing on black: */
+ memset(&png_ptr->background, 0, (sizeof png_ptr->background));
+ png_ptr->background_gamma = png_ptr->colorspace.gamma; /* just in case */
+ png_ptr->background_gamma_type = PNG_BACKGROUND_GAMMA_FILE;
+ png_ptr->transformations &= ~PNG_BACKGROUND_EXPAND;
+
+ if ((png_ptr->transformations & PNG_COMPOSE) != 0)
+ png_error(png_ptr,
+ "conflicting calls to set alpha mode and background");
+
+ png_ptr->transformations |= PNG_COMPOSE;
+ }
+}
+
+# ifdef PNG_FLOATING_POINT_SUPPORTED
+void PNGAPI
+png_set_alpha_mode(png_structrp png_ptr, int mode, double output_gamma)
+{
+ png_set_alpha_mode_fixed(png_ptr, mode, convert_gamma_value(png_ptr,
+ output_gamma));
+}
+# endif
+#endif
+
+#ifdef PNG_READ_QUANTIZE_SUPPORTED
+/* Dither file to 8-bit. Supply a palette, the current number
+ * of elements in the palette, the maximum number of elements
+ * allowed, and a histogram if possible. If the current number
+ * of colors is greater than the maximum number, the palette will be
+ * modified to fit in the maximum number. "full_quantize" indicates
+ * whether we need a quantizing cube set up for RGB images, or if we
+ * simply are reducing the number of colors in a paletted image.
+ */
+
+typedef struct png_dsort_struct
+{
+ struct png_dsort_struct * next;
+ png_byte left;
+ png_byte right;
+} png_dsort;
+typedef png_dsort * png_dsortp;
+typedef png_dsort * * png_dsortpp;
+
+void PNGAPI
+png_set_quantize(png_structrp png_ptr, png_colorp palette,
+ int num_palette, int maximum_colors, png_const_uint_16p histogram,
+ int full_quantize)
+{
+ png_debug(1, "in png_set_quantize");
+
+ if (png_rtran_ok(png_ptr, 0) == 0)
+ return;
+
+ png_ptr->transformations |= PNG_QUANTIZE;
+
+ if (full_quantize == 0)
+ {
+ int i;
+
+ png_ptr->quantize_index = (png_bytep)png_malloc(png_ptr,
+ (png_uint_32)(num_palette * (sizeof (png_byte))));
+ for (i = 0; i < num_palette; i++)
+ png_ptr->quantize_index[i] = (png_byte)i;
+ }
+
+ if (num_palette > maximum_colors)
+ {
+ if (histogram != NULL)
+ {
+ /* This is easy enough, just throw out the least used colors.
+ * Perhaps not the best solution, but good enough.
+ */
+
+ int i;
+
+ /* Initialize an array to sort colors */
+ png_ptr->quantize_sort = (png_bytep)png_malloc(png_ptr,
+ (png_uint_32)(num_palette * (sizeof (png_byte))));
+
+ /* Initialize the quantize_sort array */
+ for (i = 0; i < num_palette; i++)
+ png_ptr->quantize_sort[i] = (png_byte)i;
+
+ /* Find the least used palette entries by starting a
+ * bubble sort, and running it until we have sorted
+ * out enough colors. Note that we don't care about
+ * sorting all the colors, just finding which are
+ * least used.
+ */
+
+ for (i = num_palette - 1; i >= maximum_colors; i--)
+ {
+ int done; /* To stop early if the list is pre-sorted */
+ int j;
+
+ done = 1;
+ for (j = 0; j < i; j++)
+ {
+ if (histogram[png_ptr->quantize_sort[j]]
+ < histogram[png_ptr->quantize_sort[j + 1]])
+ {
+ png_byte t;
+
+ t = png_ptr->quantize_sort[j];
+ png_ptr->quantize_sort[j] = png_ptr->quantize_sort[j + 1];
+ png_ptr->quantize_sort[j + 1] = t;
+ done = 0;
+ }
+ }
+
+ if (done != 0)
+ break;
+ }
+
+ /* Swap the palette around, and set up a table, if necessary */
+ if (full_quantize != 0)
+ {
+ int j = num_palette;
+
+ /* Put all the useful colors within the max, but don't
+ * move the others.
+ */
+ for (i = 0; i < maximum_colors; i++)
+ {
+ if ((int)png_ptr->quantize_sort[i] >= maximum_colors)
+ {
+ do
+ j--;
+ while ((int)png_ptr->quantize_sort[j] >= maximum_colors);
+
+ palette[i] = palette[j];
+ }
+ }
+ }
+ else
+ {
+ int j = num_palette;
+
+ /* Move all the used colors inside the max limit, and
+ * develop a translation table.
+ */
+ for (i = 0; i < maximum_colors; i++)
+ {
+ /* Only move the colors we need to */
+ if ((int)png_ptr->quantize_sort[i] >= maximum_colors)
+ {
+ png_color tmp_color;
+
+ do
+ j--;
+ while ((int)png_ptr->quantize_sort[j] >= maximum_colors);
+
+ tmp_color = palette[j];
+ palette[j] = palette[i];
+ palette[i] = tmp_color;
+ /* Indicate where the color went */
+ png_ptr->quantize_index[j] = (png_byte)i;
+ png_ptr->quantize_index[i] = (png_byte)j;
+ }
+ }
+
+ /* Find closest color for those colors we are not using */
+ for (i = 0; i < num_palette; i++)
+ {
+ if ((int)png_ptr->quantize_index[i] >= maximum_colors)
+ {
+ int min_d, k, min_k, d_index;
+
+ /* Find the closest color to one we threw out */
+ d_index = png_ptr->quantize_index[i];
+ min_d = PNG_COLOR_DIST(palette[d_index], palette[0]);
+ for (k = 1, min_k = 0; k < maximum_colors; k++)
+ {
+ int d;
+
+ d = PNG_COLOR_DIST(palette[d_index], palette[k]);
+
+ if (d < min_d)
+ {
+ min_d = d;
+ min_k = k;
+ }
+ }
+ /* Point to closest color */
+ png_ptr->quantize_index[i] = (png_byte)min_k;
+ }
+ }
+ }
+ png_free(png_ptr, png_ptr->quantize_sort);
+ png_ptr->quantize_sort = NULL;
+ }
+ else
+ {
+ /* This is much harder to do simply (and quickly). Perhaps
+ * we need to go through a median cut routine, but those
+ * don't always behave themselves with only a few colors
+ * as input. So we will just find the closest two colors,
+ * and throw out one of them (chosen somewhat randomly).
+ * [We don't understand this at all, so if someone wants to
+ * work on improving it, be our guest - AED, GRP]
+ */
+ int i;
+ int max_d;
+ int num_new_palette;
+ png_dsortp t;
+ png_dsortpp hash;
+
+ t = NULL;
+
+ /* Initialize palette index arrays */
+ png_ptr->index_to_palette = (png_bytep)png_malloc(png_ptr,
+ (png_uint_32)(num_palette * (sizeof (png_byte))));
+ png_ptr->palette_to_index = (png_bytep)png_malloc(png_ptr,
+ (png_uint_32)(num_palette * (sizeof (png_byte))));
+
+ /* Initialize the sort array */
+ for (i = 0; i < num_palette; i++)
+ {
+ png_ptr->index_to_palette[i] = (png_byte)i;
+ png_ptr->palette_to_index[i] = (png_byte)i;
+ }
+
+ hash = (png_dsortpp)png_calloc(png_ptr, (png_uint_32)(769 *
+ (sizeof (png_dsortp))));
+
+ num_new_palette = num_palette;
+
+ /* Initial wild guess at how far apart the farthest pixel
+ * pair we will be eliminating will be. Larger
+ * numbers mean more areas will be allocated, Smaller
+ * numbers run the risk of not saving enough data, and
+ * having to do this all over again.
+ *
+ * I have not done extensive checking on this number.
+ */
+ max_d = 96;
+
+ while (num_new_palette > maximum_colors)
+ {
+ for (i = 0; i < num_new_palette - 1; i++)
+ {
+ int j;
+
+ for (j = i + 1; j < num_new_palette; j++)
+ {
+ int d;
+
+ d = PNG_COLOR_DIST(palette[i], palette[j]);
+
+ if (d <= max_d)
+ {
+
+ t = (png_dsortp)png_malloc_warn(png_ptr,
+ (png_uint_32)(sizeof (png_dsort)));
+
+ if (t == NULL)
+ break;
+
+ t->next = hash[d];
+ t->left = (png_byte)i;
+ t->right = (png_byte)j;
+ hash[d] = t;
+ }
+ }
+ if (t == NULL)
+ break;
+ }
+
+ if (t != NULL)
+ for (i = 0; i <= max_d; i++)
+ {
+ if (hash[i] != NULL)
+ {
+ png_dsortp p;
+
+ for (p = hash[i]; p; p = p->next)
+ {
+ if ((int)png_ptr->index_to_palette[p->left]
+ < num_new_palette &&
+ (int)png_ptr->index_to_palette[p->right]
+ < num_new_palette)
+ {
+ int j, next_j;
+
+ if (num_new_palette & 0x01)
+ {
+ j = p->left;
+ next_j = p->right;
+ }
+ else
+ {
+ j = p->right;
+ next_j = p->left;
+ }
+
+ num_new_palette--;
+ palette[png_ptr->index_to_palette[j]]
+ = palette[num_new_palette];
+ if (full_quantize == 0)
+ {
+ int k;
+
+ for (k = 0; k < num_palette; k++)
+ {
+ if (png_ptr->quantize_index[k] ==
+ png_ptr->index_to_palette[j])
+ png_ptr->quantize_index[k] =
+ png_ptr->index_to_palette[next_j];
+
+ if ((int)png_ptr->quantize_index[k] ==
+ num_new_palette)
+ png_ptr->quantize_index[k] =
+ png_ptr->index_to_palette[j];
+ }
+ }
+
+ png_ptr->index_to_palette[png_ptr->palette_to_index
+ [num_new_palette]] = png_ptr->index_to_palette[j];
+
+ png_ptr->palette_to_index[png_ptr->index_to_palette[j]]
+ = png_ptr->palette_to_index[num_new_palette];
+
+ png_ptr->index_to_palette[j] =
+ (png_byte)num_new_palette;
+
+ png_ptr->palette_to_index[num_new_palette] =
+ (png_byte)j;
+ }
+ if (num_new_palette <= maximum_colors)
+ break;
+ }
+ if (num_new_palette <= maximum_colors)
+ break;
+ }
+ }
+
+ for (i = 0; i < 769; i++)
+ {
+ if (hash[i] != NULL)
+ {
+ png_dsortp p = hash[i];
+ while (p)
+ {
+ t = p->next;
+ png_free(png_ptr, p);
+ p = t;
+ }
+ }
+ hash[i] = 0;
+ }
+ max_d += 96;
+ }
+ png_free(png_ptr, hash);
+ png_free(png_ptr, png_ptr->palette_to_index);
+ png_free(png_ptr, png_ptr->index_to_palette);
+ png_ptr->palette_to_index = NULL;
+ png_ptr->index_to_palette = NULL;
+ }
+ num_palette = maximum_colors;
+ }
+ if (png_ptr->palette == NULL)
+ {
+ png_ptr->palette = palette;
+ }
+ png_ptr->num_palette = (png_uint_16)num_palette;
+
+ if (full_quantize != 0)
+ {
+ int i;
+ png_bytep distance;
+ int total_bits = PNG_QUANTIZE_RED_BITS + PNG_QUANTIZE_GREEN_BITS +
+ PNG_QUANTIZE_BLUE_BITS;
+ int num_red = (1 << PNG_QUANTIZE_RED_BITS);
+ int num_green = (1 << PNG_QUANTIZE_GREEN_BITS);
+ int num_blue = (1 << PNG_QUANTIZE_BLUE_BITS);
+ png_size_t num_entries = ((png_size_t)1 << total_bits);
+
+ png_ptr->palette_lookup = (png_bytep)png_calloc(png_ptr,
+ (png_uint_32)(num_entries * (sizeof (png_byte))));
+
+ distance = (png_bytep)png_malloc(png_ptr, (png_uint_32)(num_entries *
+ (sizeof (png_byte))));
+
+ memset(distance, 0xff, num_entries * (sizeof (png_byte)));
+
+ for (i = 0; i < num_palette; i++)
+ {
+ int ir, ig, ib;
+ int r = (palette[i].red >> (8 - PNG_QUANTIZE_RED_BITS));
+ int g = (palette[i].green >> (8 - PNG_QUANTIZE_GREEN_BITS));
+ int b = (palette[i].blue >> (8 - PNG_QUANTIZE_BLUE_BITS));
+
+ for (ir = 0; ir < num_red; ir++)
+ {
+ /* int dr = abs(ir - r); */
+ int dr = ((ir > r) ? ir - r : r - ir);
+ int index_r = (ir << (PNG_QUANTIZE_BLUE_BITS +
+ PNG_QUANTIZE_GREEN_BITS));
+
+ for (ig = 0; ig < num_green; ig++)
+ {
+ /* int dg = abs(ig - g); */
+ int dg = ((ig > g) ? ig - g : g - ig);
+ int dt = dr + dg;
+ int dm = ((dr > dg) ? dr : dg);
+ int index_g = index_r | (ig << PNG_QUANTIZE_BLUE_BITS);
+
+ for (ib = 0; ib < num_blue; ib++)
+ {
+ int d_index = index_g | ib;
+ /* int db = abs(ib - b); */
+ int db = ((ib > b) ? ib - b : b - ib);
+ int dmax = ((dm > db) ? dm : db);
+ int d = dmax + dt + db;
+
+ if (d < (int)distance[d_index])
+ {
+ distance[d_index] = (png_byte)d;
+ png_ptr->palette_lookup[d_index] = (png_byte)i;
+ }
+ }
+ }
+ }
+ }
+
+ png_free(png_ptr, distance);
+ }
+}
+#endif /* READ_QUANTIZE */
+
+#ifdef PNG_READ_GAMMA_SUPPORTED
+void PNGFAPI
+png_set_gamma_fixed(png_structrp png_ptr, png_fixed_point scrn_gamma,
+ png_fixed_point file_gamma)
+{
+ png_debug(1, "in png_set_gamma_fixed");
+
+ if (png_rtran_ok(png_ptr, 0) == 0)
+ return;
+
+ /* New in libpng-1.5.4 - reserve particular negative values as flags. */
+ scrn_gamma = translate_gamma_flags(png_ptr, scrn_gamma, 1/*screen*/);
+ file_gamma = translate_gamma_flags(png_ptr, file_gamma, 0/*file*/);
+
+ /* Checking the gamma values for being >0 was added in 1.5.4 along with the
+ * premultiplied alpha support; this actually hides an undocumented feature
+ * of the previous implementation which allowed gamma processing to be
+ * disabled in background handling. There is no evidence (so far) that this
+ * was being used; however, png_set_background itself accepted and must still
+ * accept '0' for the gamma value it takes, because it isn't always used.
+ *
+ * Since this is an API change (albeit a very minor one that removes an
+ * undocumented API feature) the following checks were only enabled in
+ * libpng-1.6.0.
+ */
+ if (file_gamma <= 0)
+ png_error(png_ptr, "invalid file gamma in png_set_gamma");
+
+ if (scrn_gamma <= 0)
+ png_error(png_ptr, "invalid screen gamma in png_set_gamma");
+
+ /* Set the gamma values unconditionally - this overrides the value in the PNG
+ * file if a gAMA chunk was present. png_set_alpha_mode provides a
+ * different, easier, way to default the file gamma.
+ */
+ png_ptr->colorspace.gamma = file_gamma;
+ png_ptr->colorspace.flags |= PNG_COLORSPACE_HAVE_GAMMA;
+ png_ptr->screen_gamma = scrn_gamma;
+}
+
+# ifdef PNG_FLOATING_POINT_SUPPORTED
+void PNGAPI
+png_set_gamma(png_structrp png_ptr, double scrn_gamma, double file_gamma)
+{
+ png_set_gamma_fixed(png_ptr, convert_gamma_value(png_ptr, scrn_gamma),
+ convert_gamma_value(png_ptr, file_gamma));
+}
+# endif /* FLOATING_POINT */
+#endif /* READ_GAMMA */
+
+#ifdef PNG_READ_EXPAND_SUPPORTED
+/* Expand paletted images to RGB, expand grayscale images of
+ * less than 8-bit depth to 8-bit depth, and expand tRNS chunks
+ * to alpha channels.
+ */
+void PNGAPI
+png_set_expand(png_structrp png_ptr)
+{
+ png_debug(1, "in png_set_expand");
+
+ if (png_rtran_ok(png_ptr, 0) == 0)
+ return;
+
+ png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS);
+}
+
+/* GRR 19990627: the following three functions currently are identical
+ * to png_set_expand(). However, it is entirely reasonable that someone
+ * might wish to expand an indexed image to RGB but *not* expand a single,
+ * fully transparent palette entry to a full alpha channel--perhaps instead
+ * convert tRNS to the grayscale/RGB format (16-bit RGB value), or replace
+ * the transparent color with a particular RGB value, or drop tRNS entirely.
+ * IOW, a future version of the library may make the transformations flag
+ * a bit more fine-grained, with separate bits for each of these three
+ * functions.
+ *
+ * More to the point, these functions make it obvious what libpng will be
+ * doing, whereas "expand" can (and does) mean any number of things.
+ *
+ * GRP 20060307: In libpng-1.2.9, png_set_gray_1_2_4_to_8() was modified
+ * to expand only the sample depth but not to expand the tRNS to alpha
+ * and its name was changed to png_set_expand_gray_1_2_4_to_8().
+ */
+
+/* Expand paletted images to RGB. */
+void PNGAPI
+png_set_palette_to_rgb(png_structrp png_ptr)
+{
+ png_debug(1, "in png_set_palette_to_rgb");
+
+ if (png_rtran_ok(png_ptr, 0) == 0)
+ return;
+
+ png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS);
+}
+
+/* Expand grayscale images of less than 8-bit depth to 8 bits. */
+void PNGAPI
+png_set_expand_gray_1_2_4_to_8(png_structrp png_ptr)
+{
+ png_debug(1, "in png_set_expand_gray_1_2_4_to_8");
+
+ if (png_rtran_ok(png_ptr, 0) == 0)
+ return;
+
+ png_ptr->transformations |= PNG_EXPAND;
+}
+
+/* Expand tRNS chunks to alpha channels. */
+void PNGAPI
+png_set_tRNS_to_alpha(png_structrp png_ptr)
+{
+ png_debug(1, "in png_set_tRNS_to_alpha");
+
+ if (png_rtran_ok(png_ptr, 0) == 0)
+ return;
+
+ png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS);
+}
+#endif /* READ_EXPAND */
+
+#ifdef PNG_READ_EXPAND_16_SUPPORTED
+/* Expand to 16-bit channels, expand the tRNS chunk too (because otherwise
+ * it may not work correctly.)
+ */
+void PNGAPI
+png_set_expand_16(png_structrp png_ptr)
+{
+ png_debug(1, "in png_set_expand_16");
+
+ if (png_rtran_ok(png_ptr, 0) == 0)
+ return;
+
+ png_ptr->transformations |= (PNG_EXPAND_16 | PNG_EXPAND | PNG_EXPAND_tRNS);
+}
+#endif
+
+#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
+void PNGAPI
+png_set_gray_to_rgb(png_structrp png_ptr)
+{
+ png_debug(1, "in png_set_gray_to_rgb");
+
+ if (png_rtran_ok(png_ptr, 0) == 0)
+ return;
+
+ /* Because rgb must be 8 bits or more: */
+ png_set_expand_gray_1_2_4_to_8(png_ptr);
+ png_ptr->transformations |= PNG_GRAY_TO_RGB;
+}
+#endif
+
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+void PNGFAPI
+png_set_rgb_to_gray_fixed(png_structrp png_ptr, int error_action,
+ png_fixed_point red, png_fixed_point green)
+{
+ png_debug(1, "in png_set_rgb_to_gray");
+
+ /* Need the IHDR here because of the check on color_type below. */
+ /* TODO: fix this */
+ if (png_rtran_ok(png_ptr, 1) == 0)
+ return;
+
+ switch (error_action)
+ {
+ case PNG_ERROR_ACTION_NONE:
+ png_ptr->transformations |= PNG_RGB_TO_GRAY;
+ break;
+
+ case PNG_ERROR_ACTION_WARN:
+ png_ptr->transformations |= PNG_RGB_TO_GRAY_WARN;
+ break;
+
+ case PNG_ERROR_ACTION_ERROR:
+ png_ptr->transformations |= PNG_RGB_TO_GRAY_ERR;
+ break;
+
+ default:
+ png_error(png_ptr, "invalid error action to rgb_to_gray");
+ }
+
+ if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+#ifdef PNG_READ_EXPAND_SUPPORTED
+ png_ptr->transformations |= PNG_EXPAND;
+#else
+ {
+ /* Make this an error in 1.6 because otherwise the application may assume
+ * that it just worked and get a memory overwrite.
+ */
+ png_error(png_ptr,
+ "Cannot do RGB_TO_GRAY without EXPAND_SUPPORTED");
+
+ /* png_ptr->transformations &= ~PNG_RGB_TO_GRAY; */
+ }
+#endif
+ {
+ if (red >= 0 && green >= 0 && red + green <= PNG_FP_1)
+ {
+ png_uint_16 red_int, green_int;
+
+ /* NOTE: this calculation does not round, but this behavior is retained
+ * for consistency; the inaccuracy is very small. The code here always
+ * overwrites the coefficients, regardless of whether they have been
+ * defaulted or set already.
+ */
+ red_int = (png_uint_16)(((png_uint_32)red*32768)/100000);
+ green_int = (png_uint_16)(((png_uint_32)green*32768)/100000);
+
+ png_ptr->rgb_to_gray_red_coeff = red_int;
+ png_ptr->rgb_to_gray_green_coeff = green_int;
+ png_ptr->rgb_to_gray_coefficients_set = 1;
+ }
+
+ else
+ {
+ if (red >= 0 && green >= 0)
+ png_app_warning(png_ptr,
+ "ignoring out of range rgb_to_gray coefficients");
+
+ /* Use the defaults, from the cHRM chunk if set, else the historical
+ * values which are close to the sRGB/HDTV/ITU-Rec 709 values. See
+ * png_do_rgb_to_gray for more discussion of the values. In this case
+ * the coefficients are not marked as 'set' and are not overwritten if
+ * something has already provided a default.
+ */
+ if (png_ptr->rgb_to_gray_red_coeff == 0 &&
+ png_ptr->rgb_to_gray_green_coeff == 0)
+ {
+ png_ptr->rgb_to_gray_red_coeff = 6968;
+ png_ptr->rgb_to_gray_green_coeff = 23434;
+ /* png_ptr->rgb_to_gray_blue_coeff = 2366; */
+ }
+ }
+ }
+}
+
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+/* Convert a RGB image to a grayscale of the same width. This allows us,
+ * for example, to convert a 24 bpp RGB image into an 8 bpp grayscale image.
+ */
+
+void PNGAPI
+png_set_rgb_to_gray(png_structrp png_ptr, int error_action, double red,
+ double green)
+{
+ png_set_rgb_to_gray_fixed(png_ptr, error_action,
+ png_fixed(png_ptr, red, "rgb to gray red coefficient"),
+ png_fixed(png_ptr, green, "rgb to gray green coefficient"));
+}
+#endif /* FLOATING POINT */
+
+#endif /* RGB_TO_GRAY */
+
+#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
+ defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
+void PNGAPI
+png_set_read_user_transform_fn(png_structrp png_ptr, png_user_transform_ptr
+ read_user_transform_fn)
+{
+ png_debug(1, "in png_set_read_user_transform_fn");
+
+#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
+ png_ptr->transformations |= PNG_USER_TRANSFORM;
+ png_ptr->read_user_transform_fn = read_user_transform_fn;
+#endif
+}
+#endif
+
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
+#ifdef PNG_READ_GAMMA_SUPPORTED
+/* In the case of gamma transformations only do transformations on images where
+ * the [file] gamma and screen_gamma are not close reciprocals, otherwise it
+ * slows things down slightly, and also needlessly introduces small errors.
+ */
+static int /* PRIVATE */
+png_gamma_threshold(png_fixed_point screen_gamma, png_fixed_point file_gamma)
+{
+ /* PNG_GAMMA_THRESHOLD is the threshold for performing gamma
+ * correction as a difference of the overall transform from 1.0
+ *
+ * We want to compare the threshold with s*f - 1, if we get
+ * overflow here it is because of wacky gamma values so we
+ * turn on processing anyway.
+ */
+ png_fixed_point gtest;
+ return !png_muldiv(>est, screen_gamma, file_gamma, PNG_FP_1) ||
+ png_gamma_significant(gtest);
+}
+#endif
+
+/* Initialize everything needed for the read. This includes modifying
+ * the palette.
+ */
+
+/* For the moment 'png_init_palette_transformations' and
+ * 'png_init_rgb_transformations' only do some flag canceling optimizations.
+ * The intent is that these two routines should have palette or rgb operations
+ * extracted from 'png_init_read_transformations'.
+ */
+static void /* PRIVATE */
+png_init_palette_transformations(png_structrp png_ptr)
+{
+ /* Called to handle the (input) palette case. In png_do_read_transformations
+ * the first step is to expand the palette if requested, so this code must
+ * take care to only make changes that are invariant with respect to the
+ * palette expansion, or only do them if there is no expansion.
+ *
+ * STRIP_ALPHA has already been handled in the caller (by setting num_trans
+ * to 0.)
+ */
+ int input_has_alpha = 0;
+ int input_has_transparency = 0;
+
+ if (png_ptr->num_trans > 0)
+ {
+ int i;
+
+ /* Ignore if all the entries are opaque (unlikely!) */
+ for (i=0; i<png_ptr->num_trans; ++i)
+ {
+ if (png_ptr->trans_alpha[i] == 255)
+ continue;
+ else if (png_ptr->trans_alpha[i] == 0)
+ input_has_transparency = 1;
+ else
+ {
+ input_has_transparency = 1;
+ input_has_alpha = 1;
+ break;
+ }
+ }
+ }
+
+ /* If no alpha we can optimize. */
+ if (input_has_alpha == 0)
+ {
+ /* Any alpha means background and associative alpha processing is
+ * required, however if the alpha is 0 or 1 throughout OPTIMIZE_ALPHA
+ * and ENCODE_ALPHA are irrelevant.
+ */
+ png_ptr->transformations &= ~PNG_ENCODE_ALPHA;
+ png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA;
+
+ if (input_has_transparency == 0)
+ png_ptr->transformations &= ~(PNG_COMPOSE | PNG_BACKGROUND_EXPAND);
+ }
+
+#if defined(PNG_READ_EXPAND_SUPPORTED) && defined(PNG_READ_BACKGROUND_SUPPORTED)
+ /* png_set_background handling - deals with the complexity of whether the
+ * background color is in the file format or the screen format in the case
+ * where an 'expand' will happen.
+ */
+
+ /* The following code cannot be entered in the alpha pre-multiplication case
+ * because PNG_BACKGROUND_EXPAND is cancelled below.
+ */
+ if ((png_ptr->transformations & PNG_BACKGROUND_EXPAND) != 0 &&
+ (png_ptr->transformations & PNG_EXPAND) != 0)
+ {
+ {
+ png_ptr->background.red =
+ png_ptr->palette[png_ptr->background.index].red;
+ png_ptr->background.green =
+ png_ptr->palette[png_ptr->background.index].green;
+ png_ptr->background.blue =
+ png_ptr->palette[png_ptr->background.index].blue;
+
+#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED
+ if ((png_ptr->transformations & PNG_INVERT_ALPHA) != 0)
+ {
+ if ((png_ptr->transformations & PNG_EXPAND_tRNS) == 0)
+ {
+ /* Invert the alpha channel (in tRNS) unless the pixels are
+ * going to be expanded, in which case leave it for later
+ */
+ int i, istop = png_ptr->num_trans;
+
+ for (i=0; i<istop; i++)
+ png_ptr->trans_alpha[i] = (png_byte)(255 -
+ png_ptr->trans_alpha[i]);
+ }
+ }
+#endif /* READ_INVERT_ALPHA */
+ }
+ } /* background expand and (therefore) no alpha association. */
+#endif /* READ_EXPAND && READ_BACKGROUND */
+}
+
+static void /* PRIVATE */
+png_init_rgb_transformations(png_structrp png_ptr)
+{
+ /* Added to libpng-1.5.4: check the color type to determine whether there
+ * is any alpha or transparency in the image and simply cancel the
+ * background and alpha mode stuff if there isn't.
+ */
+ int input_has_alpha = (png_ptr->color_type & PNG_COLOR_MASK_ALPHA) != 0;
+ int input_has_transparency = png_ptr->num_trans > 0;
+
+ /* If no alpha we can optimize. */
+ if (input_has_alpha == 0)
+ {
+ /* Any alpha means background and associative alpha processing is
+ * required, however if the alpha is 0 or 1 throughout OPTIMIZE_ALPHA
+ * and ENCODE_ALPHA are irrelevant.
+ */
+# ifdef PNG_READ_ALPHA_MODE_SUPPORTED
+ png_ptr->transformations &= ~PNG_ENCODE_ALPHA;
+ png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA;
+# endif
+
+ if (input_has_transparency == 0)
+ png_ptr->transformations &= ~(PNG_COMPOSE | PNG_BACKGROUND_EXPAND);
+ }
+
+#if defined(PNG_READ_EXPAND_SUPPORTED) && defined(PNG_READ_BACKGROUND_SUPPORTED)
+ /* png_set_background handling - deals with the complexity of whether the
+ * background color is in the file format or the screen format in the case
+ * where an 'expand' will happen.
+ */
+
+ /* The following code cannot be entered in the alpha pre-multiplication case
+ * because PNG_BACKGROUND_EXPAND is cancelled below.
+ */
+ if ((png_ptr->transformations & PNG_BACKGROUND_EXPAND) != 0 &&
+ (png_ptr->transformations & PNG_EXPAND) != 0 &&
+ (png_ptr->color_type & PNG_COLOR_MASK_COLOR) == 0)
+ /* i.e., GRAY or GRAY_ALPHA */
+ {
+ {
+ /* Expand background and tRNS chunks */
+ int gray = png_ptr->background.gray;
+ int trans_gray = png_ptr->trans_color.gray;
+
+ switch (png_ptr->bit_depth)
+ {
+ case 1:
+ gray *= 0xff;
+ trans_gray *= 0xff;
+ break;
+
+ case 2:
+ gray *= 0x55;
+ trans_gray *= 0x55;
+ break;
+
+ case 4:
+ gray *= 0x11;
+ trans_gray *= 0x11;
+ break;
+
+ default:
+
+ case 8:
+ /* FALL THROUGH (Already 8 bits) */
+
+ case 16:
+ /* Already a full 16 bits */
+ break;
+ }
+
+ png_ptr->background.red = png_ptr->background.green =
+ png_ptr->background.blue = (png_uint_16)gray;
+
+ if ((png_ptr->transformations & PNG_EXPAND_tRNS) == 0)
+ {
+ png_ptr->trans_color.red = png_ptr->trans_color.green =
+ png_ptr->trans_color.blue = (png_uint_16)trans_gray;
+ }
+ }
+ } /* background expand and (therefore) no alpha association. */
+#endif /* READ_EXPAND && READ_BACKGROUND */
+}
+
+void /* PRIVATE */
+png_init_read_transformations(png_structrp png_ptr)
+{
+ png_debug(1, "in png_init_read_transformations");
+
+ /* This internal function is called from png_read_start_row in pngrutil.c
+ * and it is called before the 'rowbytes' calculation is done, so the code
+ * in here can change or update the transformations flags.
+ *
+ * First do updates that do not depend on the details of the PNG image data
+ * being processed.
+ */
+
+#ifdef PNG_READ_GAMMA_SUPPORTED
+ /* Prior to 1.5.4 these tests were performed from png_set_gamma, 1.5.4 adds
+ * png_set_alpha_mode and this is another source for a default file gamma so
+ * the test needs to be performed later - here. In addition prior to 1.5.4
+ * the tests were repeated for the PALETTE color type here - this is no
+ * longer necessary (and doesn't seem to have been necessary before.)
+ */
+ {
+ /* The following temporary indicates if overall gamma correction is
+ * required.
+ */
+ int gamma_correction = 0;
+
+ if (png_ptr->colorspace.gamma != 0) /* has been set */
+ {
+ if (png_ptr->screen_gamma != 0) /* screen set too */
+ gamma_correction = png_gamma_threshold(png_ptr->colorspace.gamma,
+ png_ptr->screen_gamma);
+
+ else
+ /* Assume the output matches the input; a long time default behavior
+ * of libpng, although the standard has nothing to say about this.
+ */
+ png_ptr->screen_gamma = png_reciprocal(png_ptr->colorspace.gamma);
+ }
+
+ else if (png_ptr->screen_gamma != 0)
+ /* The converse - assume the file matches the screen, note that this
+ * perhaps undesireable default can (from 1.5.4) be changed by calling
+ * png_set_alpha_mode (even if the alpha handling mode isn't required
+ * or isn't changed from the default.)
+ */
+ png_ptr->colorspace.gamma = png_reciprocal(png_ptr->screen_gamma);
+
+ else /* neither are set */
+ /* Just in case the following prevents any processing - file and screen
+ * are both assumed to be linear and there is no way to introduce a
+ * third gamma value other than png_set_background with 'UNIQUE', and,
+ * prior to 1.5.4
+ */
+ png_ptr->screen_gamma = png_ptr->colorspace.gamma = PNG_FP_1;
+
+ /* We have a gamma value now. */
+ png_ptr->colorspace.flags |= PNG_COLORSPACE_HAVE_GAMMA;
+
+ /* Now turn the gamma transformation on or off as appropriate. Notice
+ * that PNG_GAMMA just refers to the file->screen correction. Alpha
+ * composition may independently cause gamma correction because it needs
+ * linear data (e.g. if the file has a gAMA chunk but the screen gamma
+ * hasn't been specified.) In any case this flag may get turned off in
+ * the code immediately below if the transform can be handled outside the
+ * row loop.
+ */
+ if (gamma_correction != 0)
+ png_ptr->transformations |= PNG_GAMMA;
+
+ else
+ png_ptr->transformations &= ~PNG_GAMMA;
+ }
+#endif
+
+ /* Certain transformations have the effect of preventing other
+ * transformations that happen afterward in png_do_read_transformations;
+ * resolve the interdependencies here. From the code of
+ * png_do_read_transformations the order is:
+ *
+ * 1) PNG_EXPAND (including PNG_EXPAND_tRNS)
+ * 2) PNG_STRIP_ALPHA (if no compose)
+ * 3) PNG_RGB_TO_GRAY
+ * 4) PNG_GRAY_TO_RGB iff !PNG_BACKGROUND_IS_GRAY
+ * 5) PNG_COMPOSE
+ * 6) PNG_GAMMA
+ * 7) PNG_STRIP_ALPHA (if compose)
+ * 8) PNG_ENCODE_ALPHA
+ * 9) PNG_SCALE_16_TO_8
+ * 10) PNG_16_TO_8
+ * 11) PNG_QUANTIZE (converts to palette)
+ * 12) PNG_EXPAND_16
+ * 13) PNG_GRAY_TO_RGB iff PNG_BACKGROUND_IS_GRAY
+ * 14) PNG_INVERT_MONO
+ * 15) PNG_INVERT_ALPHA
+ * 16) PNG_SHIFT
+ * 17) PNG_PACK
+ * 18) PNG_BGR
+ * 19) PNG_PACKSWAP
+ * 20) PNG_FILLER (includes PNG_ADD_ALPHA)
+ * 21) PNG_SWAP_ALPHA
+ * 22) PNG_SWAP_BYTES
+ * 23) PNG_USER_TRANSFORM [must be last]
+ */
+#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
+ if ((png_ptr->transformations & PNG_STRIP_ALPHA) != 0 &&
+ (png_ptr->transformations & PNG_COMPOSE) == 0)
+ {
+ /* Stripping the alpha channel happens immediately after the 'expand'
+ * transformations, before all other transformation, so it cancels out
+ * the alpha handling. It has the side effect negating the effect of
+ * PNG_EXPAND_tRNS too:
+ */
+ png_ptr->transformations &= ~(PNG_BACKGROUND_EXPAND | PNG_ENCODE_ALPHA |
+ PNG_EXPAND_tRNS);
+ png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA;
+
+ /* Kill the tRNS chunk itself too. Prior to 1.5.4 this did not happen
+ * so transparency information would remain just so long as it wasn't
+ * expanded. This produces unexpected API changes if the set of things
+ * that do PNG_EXPAND_tRNS changes (perfectly possible given the
+ * documentation - which says ask for what you want, accept what you
+ * get.) This makes the behavior consistent from 1.5.4:
+ */
+ png_ptr->num_trans = 0;
+ }
+#endif /* STRIP_ALPHA supported, no COMPOSE */
+
+#ifdef PNG_READ_ALPHA_MODE_SUPPORTED
+ /* If the screen gamma is about 1.0 then the OPTIMIZE_ALPHA and ENCODE_ALPHA
+ * settings will have no effect.
+ */
+ if (png_gamma_significant(png_ptr->screen_gamma) == 0)
+ {
+ png_ptr->transformations &= ~PNG_ENCODE_ALPHA;
+ png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA;
+ }
+#endif
+
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+ /* Make sure the coefficients for the rgb to gray conversion are set
+ * appropriately.
+ */
+ if ((png_ptr->transformations & PNG_RGB_TO_GRAY) != 0)
+ png_colorspace_set_rgb_coefficients(png_ptr);
+#endif
+
+#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
+#if defined(PNG_READ_EXPAND_SUPPORTED) && defined(PNG_READ_BACKGROUND_SUPPORTED)
+ /* Detect gray background and attempt to enable optimization for
+ * gray --> RGB case.
+ *
+ * Note: if PNG_BACKGROUND_EXPAND is set and color_type is either RGB or
+ * RGB_ALPHA (in which case need_expand is superfluous anyway), the
+ * background color might actually be gray yet not be flagged as such.
+ * This is not a problem for the current code, which uses
+ * PNG_BACKGROUND_IS_GRAY only to decide when to do the
+ * png_do_gray_to_rgb() transformation.
+ *
+ * TODO: this code needs to be revised to avoid the complexity and
+ * interdependencies. The color type of the background should be recorded in
+ * png_set_background, along with the bit depth, then the code has a record
+ * of exactly what color space the background is currently in.
+ */
+ if ((png_ptr->transformations & PNG_BACKGROUND_EXPAND) != 0)
+ {
+ /* PNG_BACKGROUND_EXPAND: the background is in the file color space, so if
+ * the file was grayscale the background value is gray.
+ */
+ if ((png_ptr->color_type & PNG_COLOR_MASK_COLOR) == 0)
+ png_ptr->mode |= PNG_BACKGROUND_IS_GRAY;
+ }
+
+ else if ((png_ptr->transformations & PNG_COMPOSE) != 0)
+ {
+ /* PNG_COMPOSE: png_set_background was called with need_expand false,
+ * so the color is in the color space of the output or png_set_alpha_mode
+ * was called and the color is black. Ignore RGB_TO_GRAY because that
+ * happens before GRAY_TO_RGB.
+ */
+ if ((png_ptr->transformations & PNG_GRAY_TO_RGB) != 0)
+ {
+ if (png_ptr->background.red == png_ptr->background.green &&
+ png_ptr->background.red == png_ptr->background.blue)
+ {
+ png_ptr->mode |= PNG_BACKGROUND_IS_GRAY;
+ png_ptr->background.gray = png_ptr->background.red;
+ }
+ }
+ }
+#endif /* READ_EXPAND && READ_BACKGROUND */
+#endif /* READ_GRAY_TO_RGB */
+
+ /* For indexed PNG data (PNG_COLOR_TYPE_PALETTE) many of the transformations
+ * can be performed directly on the palette, and some (such as rgb to gray)
+ * can be optimized inside the palette. This is particularly true of the
+ * composite (background and alpha) stuff, which can be pretty much all done
+ * in the palette even if the result is expanded to RGB or gray afterward.
+ *
+ * NOTE: this is Not Yet Implemented, the code behaves as in 1.5.1 and
+ * earlier and the palette stuff is actually handled on the first row. This
+ * leads to the reported bug that the palette returned by png_get_PLTE is not
+ * updated.
+ */
+ if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+ png_init_palette_transformations(png_ptr);
+
+ else
+ png_init_rgb_transformations(png_ptr);
+
+#if defined(PNG_READ_BACKGROUND_SUPPORTED) && \
+ defined(PNG_READ_EXPAND_16_SUPPORTED)
+ if ((png_ptr->transformations & PNG_EXPAND_16) != 0 &&
+ (png_ptr->transformations & PNG_COMPOSE) != 0 &&
+ (png_ptr->transformations & PNG_BACKGROUND_EXPAND) == 0 &&
+ png_ptr->bit_depth != 16)
+ {
+ /* TODO: fix this. Because the expand_16 operation is after the compose
+ * handling the background color must be 8, not 16, bits deep, but the
+ * application will supply a 16-bit value so reduce it here.
+ *
+ * The PNG_BACKGROUND_EXPAND code above does not expand to 16 bits at
+ * present, so that case is ok (until do_expand_16 is moved.)
+ *
+ * NOTE: this discards the low 16 bits of the user supplied background
+ * color, but until expand_16 works properly there is no choice!
+ */
+# define CHOP(x) (x)=((png_uint_16)PNG_DIV257(x))
+ CHOP(png_ptr->background.red);
+ CHOP(png_ptr->background.green);
+ CHOP(png_ptr->background.blue);
+ CHOP(png_ptr->background.gray);
+# undef CHOP
+ }
+#endif /* READ_BACKGROUND && READ_EXPAND_16 */
+
+#if defined(PNG_READ_BACKGROUND_SUPPORTED) && \
+ (defined(PNG_READ_SCALE_16_TO_8_SUPPORTED) || \
+ defined(PNG_READ_STRIP_16_TO_8_SUPPORTED))
+ if ((png_ptr->transformations & (PNG_16_TO_8|PNG_SCALE_16_TO_8)) != 0 &&
+ (png_ptr->transformations & PNG_COMPOSE) != 0 &&
+ (png_ptr->transformations & PNG_BACKGROUND_EXPAND) == 0 &&
+ png_ptr->bit_depth == 16)
+ {
+ /* On the other hand, if a 16-bit file is to be reduced to 8-bits per
+ * component this will also happen after PNG_COMPOSE and so the background
+ * color must be pre-expanded here.
+ *
+ * TODO: fix this too.
+ */
+ png_ptr->background.red = (png_uint_16)(png_ptr->background.red * 257);
+ png_ptr->background.green =
+ (png_uint_16)(png_ptr->background.green * 257);
+ png_ptr->background.blue = (png_uint_16)(png_ptr->background.blue * 257);
+ png_ptr->background.gray = (png_uint_16)(png_ptr->background.gray * 257);
+ }
+#endif
+
+ /* NOTE: below 'PNG_READ_ALPHA_MODE_SUPPORTED' is presumed to also enable the
+ * background support (see the comments in scripts/pnglibconf.dfa), this
+ * allows pre-multiplication of the alpha channel to be implemented as
+ * compositing on black. This is probably sub-optimal and has been done in
+ * 1.5.4 betas simply to enable external critique and testing (i.e. to
+ * implement the new API quickly, without lots of internal changes.)
+ */
+
+#ifdef PNG_READ_GAMMA_SUPPORTED
+# ifdef PNG_READ_BACKGROUND_SUPPORTED
+ /* Includes ALPHA_MODE */
+ png_ptr->background_1 = png_ptr->background;
+# endif
+
+ /* This needs to change - in the palette image case a whole set of tables are
+ * built when it would be quicker to just calculate the correct value for
+ * each palette entry directly. Also, the test is too tricky - why check
+ * PNG_RGB_TO_GRAY if PNG_GAMMA is not set? The answer seems to be that
+ * PNG_GAMMA is cancelled even if the gamma is known? The test excludes the
+ * PNG_COMPOSE case, so apparently if there is no *overall* gamma correction
+ * the gamma tables will not be built even if composition is required on a
+ * gamma encoded value.
+ *
+ * In 1.5.4 this is addressed below by an additional check on the individual
+ * file gamma - if it is not 1.0 both RGB_TO_GRAY and COMPOSE need the
+ * tables.
+ */
+ if ((png_ptr->transformations & PNG_GAMMA) != 0 ||
+ ((png_ptr->transformations & PNG_RGB_TO_GRAY) != 0 &&
+ (png_gamma_significant(png_ptr->colorspace.gamma) != 0 ||
+ png_gamma_significant(png_ptr->screen_gamma) != 0)) ||
+ ((png_ptr->transformations & PNG_COMPOSE) != 0 &&
+ (png_gamma_significant(png_ptr->colorspace.gamma) != 0 ||
+ png_gamma_significant(png_ptr->screen_gamma) != 0
+# ifdef PNG_READ_BACKGROUND_SUPPORTED
+ || (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_UNIQUE &&
+ png_gamma_significant(png_ptr->background_gamma) != 0)
+# endif
+ )) || ((png_ptr->transformations & PNG_ENCODE_ALPHA) != 0 &&
+ png_gamma_significant(png_ptr->screen_gamma) != 0))
+ {
+ png_build_gamma_table(png_ptr, png_ptr->bit_depth);
+
+#ifdef PNG_READ_BACKGROUND_SUPPORTED
+ if ((png_ptr->transformations & PNG_COMPOSE) != 0)
+ {
+ /* Issue a warning about this combination: because RGB_TO_GRAY is
+ * optimized to do the gamma transform if present yet do_background has
+ * to do the same thing if both options are set a
+ * double-gamma-correction happens. This is true in all versions of
+ * libpng to date.
+ */
+ if ((png_ptr->transformations & PNG_RGB_TO_GRAY) != 0)
+ png_warning(png_ptr,
+ "libpng does not support gamma+background+rgb_to_gray");
+
+ if ((png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) != 0)
+ {
+ /* We don't get to here unless there is a tRNS chunk with non-opaque
+ * entries - see the checking code at the start of this function.
+ */
+ png_color back, back_1;
+ png_colorp palette = png_ptr->palette;
+ int num_palette = png_ptr->num_palette;
+ int i;
+ if (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_FILE)
+ {
+
+ back.red = png_ptr->gamma_table[png_ptr->background.red];
+ back.green = png_ptr->gamma_table[png_ptr->background.green];
+ back.blue = png_ptr->gamma_table[png_ptr->background.blue];
+
+ back_1.red = png_ptr->gamma_to_1[png_ptr->background.red];
+ back_1.green = png_ptr->gamma_to_1[png_ptr->background.green];
+ back_1.blue = png_ptr->gamma_to_1[png_ptr->background.blue];
+ }
+ else
+ {
+ png_fixed_point g, gs;
+
+ switch (png_ptr->background_gamma_type)
+ {
+ case PNG_BACKGROUND_GAMMA_SCREEN:
+ g = (png_ptr->screen_gamma);
+ gs = PNG_FP_1;
+ break;
+
+ case PNG_BACKGROUND_GAMMA_FILE:
+ g = png_reciprocal(png_ptr->colorspace.gamma);
+ gs = png_reciprocal2(png_ptr->colorspace.gamma,
+ png_ptr->screen_gamma);
+ break;
+
+ case PNG_BACKGROUND_GAMMA_UNIQUE:
+ g = png_reciprocal(png_ptr->background_gamma);
+ gs = png_reciprocal2(png_ptr->background_gamma,
+ png_ptr->screen_gamma);
+ break;
+ default:
+ g = PNG_FP_1; /* back_1 */
+ gs = PNG_FP_1; /* back */
+ break;
+ }
+
+ if (png_gamma_significant(gs) != 0)
+ {
+ back.red = png_gamma_8bit_correct(png_ptr->background.red,
+ gs);
+ back.green = png_gamma_8bit_correct(png_ptr->background.green,
+ gs);
+ back.blue = png_gamma_8bit_correct(png_ptr->background.blue,
+ gs);
+ }
+
+ else
+ {
+ back.red = (png_byte)png_ptr->background.red;
+ back.green = (png_byte)png_ptr->background.green;
+ back.blue = (png_byte)png_ptr->background.blue;
+ }
+
+ if (png_gamma_significant(g) != 0)
+ {
+ back_1.red = png_gamma_8bit_correct(png_ptr->background.red,
+ g);
+ back_1.green = png_gamma_8bit_correct(
+ png_ptr->background.green, g);
+ back_1.blue = png_gamma_8bit_correct(png_ptr->background.blue,
+ g);
+ }
+
+ else
+ {
+ back_1.red = (png_byte)png_ptr->background.red;
+ back_1.green = (png_byte)png_ptr->background.green;
+ back_1.blue = (png_byte)png_ptr->background.blue;
+ }
+ }
+
+ for (i = 0; i < num_palette; i++)
+ {
+ if (i < (int)png_ptr->num_trans &&
+ png_ptr->trans_alpha[i] != 0xff)
+ {
+ if (png_ptr->trans_alpha[i] == 0)
+ {
+ palette[i] = back;
+ }
+ else /* if (png_ptr->trans_alpha[i] != 0xff) */
+ {
+ png_byte v, w;
+
+ v = png_ptr->gamma_to_1[palette[i].red];
+ png_composite(w, v, png_ptr->trans_alpha[i], back_1.red);
+ palette[i].red = png_ptr->gamma_from_1[w];
+
+ v = png_ptr->gamma_to_1[palette[i].green];
+ png_composite(w, v, png_ptr->trans_alpha[i], back_1.green);
+ palette[i].green = png_ptr->gamma_from_1[w];
+
+ v = png_ptr->gamma_to_1[palette[i].blue];
+ png_composite(w, v, png_ptr->trans_alpha[i], back_1.blue);
+ palette[i].blue = png_ptr->gamma_from_1[w];
+ }
+ }
+ else
+ {
+ palette[i].red = png_ptr->gamma_table[palette[i].red];
+ palette[i].green = png_ptr->gamma_table[palette[i].green];
+ palette[i].blue = png_ptr->gamma_table[palette[i].blue];
+ }
+ }
+
+ /* Prevent the transformations being done again.
+ *
+ * NOTE: this is highly dubious; it removes the transformations in
+ * place. This seems inconsistent with the general treatment of the
+ * transformations elsewhere.
+ */
+ png_ptr->transformations &= ~(PNG_COMPOSE | PNG_GAMMA);
+ } /* color_type == PNG_COLOR_TYPE_PALETTE */
+
+ /* if (png_ptr->background_gamma_type!=PNG_BACKGROUND_GAMMA_UNKNOWN) */
+ else /* color_type != PNG_COLOR_TYPE_PALETTE */
+ {
+ int gs_sig, g_sig;
+ png_fixed_point g = PNG_FP_1; /* Correction to linear */
+ png_fixed_point gs = PNG_FP_1; /* Correction to screen */
+
+ switch (png_ptr->background_gamma_type)
+ {
+ case PNG_BACKGROUND_GAMMA_SCREEN:
+ g = png_ptr->screen_gamma;
+ /* gs = PNG_FP_1; */
+ break;
+
+ case PNG_BACKGROUND_GAMMA_FILE:
+ g = png_reciprocal(png_ptr->colorspace.gamma);
+ gs = png_reciprocal2(png_ptr->colorspace.gamma,
+ png_ptr->screen_gamma);
+ break;
+
+ case PNG_BACKGROUND_GAMMA_UNIQUE:
+ g = png_reciprocal(png_ptr->background_gamma);
+ gs = png_reciprocal2(png_ptr->background_gamma,
+ png_ptr->screen_gamma);
+ break;
+
+ default:
+ png_error(png_ptr, "invalid background gamma type");
+ }
+
+ g_sig = png_gamma_significant(g);
+ gs_sig = png_gamma_significant(gs);
+
+ if (g_sig != 0)
+ png_ptr->background_1.gray = png_gamma_correct(png_ptr,
+ png_ptr->background.gray, g);
+
+ if (gs_sig != 0)
+ png_ptr->background.gray = png_gamma_correct(png_ptr,
+ png_ptr->background.gray, gs);
+
+ if ((png_ptr->background.red != png_ptr->background.green) ||
+ (png_ptr->background.red != png_ptr->background.blue) ||
+ (png_ptr->background.red != png_ptr->background.gray))
+ {
+ /* RGB or RGBA with color background */
+ if (g_sig != 0)
+ {
+ png_ptr->background_1.red = png_gamma_correct(png_ptr,
+ png_ptr->background.red, g);
+
+ png_ptr->background_1.green = png_gamma_correct(png_ptr,
+ png_ptr->background.green, g);
+
+ png_ptr->background_1.blue = png_gamma_correct(png_ptr,
+ png_ptr->background.blue, g);
+ }
+
+ if (gs_sig != 0)
+ {
+ png_ptr->background.red = png_gamma_correct(png_ptr,
+ png_ptr->background.red, gs);
+
+ png_ptr->background.green = png_gamma_correct(png_ptr,
+ png_ptr->background.green, gs);
+
+ png_ptr->background.blue = png_gamma_correct(png_ptr,
+ png_ptr->background.blue, gs);
+ }
+ }
+
+ else
+ {
+ /* GRAY, GRAY ALPHA, RGB, or RGBA with gray background */
+ png_ptr->background_1.red = png_ptr->background_1.green
+ = png_ptr->background_1.blue = png_ptr->background_1.gray;
+
+ png_ptr->background.red = png_ptr->background.green
+ = png_ptr->background.blue = png_ptr->background.gray;
+ }
+
+ /* The background is now in screen gamma: */
+ png_ptr->background_gamma_type = PNG_BACKGROUND_GAMMA_SCREEN;
+ } /* color_type != PNG_COLOR_TYPE_PALETTE */
+ }/* png_ptr->transformations & PNG_BACKGROUND */
+
+ else
+ /* Transformation does not include PNG_BACKGROUND */
+#endif /* READ_BACKGROUND */
+ if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+ /* RGB_TO_GRAY needs to have non-gamma-corrected values! */
+ && ((png_ptr->transformations & PNG_EXPAND) == 0 ||
+ (png_ptr->transformations & PNG_RGB_TO_GRAY) == 0)
+#endif
+ )
+ {
+ png_colorp palette = png_ptr->palette;
+ int num_palette = png_ptr->num_palette;
+ int i;
+
+ /* NOTE: there are other transformations that should probably be in
+ * here too.
+ */
+ for (i = 0; i < num_palette; i++)
+ {
+ palette[i].red = png_ptr->gamma_table[palette[i].red];
+ palette[i].green = png_ptr->gamma_table[palette[i].green];
+ palette[i].blue = png_ptr->gamma_table[palette[i].blue];
+ }
+
+ /* Done the gamma correction. */
+ png_ptr->transformations &= ~PNG_GAMMA;
+ } /* color_type == PALETTE && !PNG_BACKGROUND transformation */
+ }
+#ifdef PNG_READ_BACKGROUND_SUPPORTED
+ else
+#endif
+#endif /* READ_GAMMA */
+
+#ifdef PNG_READ_BACKGROUND_SUPPORTED
+ /* No GAMMA transformation (see the hanging else 4 lines above) */
+ if ((png_ptr->transformations & PNG_COMPOSE) != 0 &&
+ (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE))
+ {
+ int i;
+ int istop = (int)png_ptr->num_trans;
+ png_color back;
+ png_colorp palette = png_ptr->palette;
+
+ back.red = (png_byte)png_ptr->background.red;
+ back.green = (png_byte)png_ptr->background.green;
+ back.blue = (png_byte)png_ptr->background.blue;
+
+ for (i = 0; i < istop; i++)
+ {
+ if (png_ptr->trans_alpha[i] == 0)
+ {
+ palette[i] = back;
+ }
+
+ else if (png_ptr->trans_alpha[i] != 0xff)
+ {
+ /* The png_composite() macro is defined in png.h */
+ png_composite(palette[i].red, palette[i].red,
+ png_ptr->trans_alpha[i], back.red);
+
+ png_composite(palette[i].green, palette[i].green,
+ png_ptr->trans_alpha[i], back.green);
+
+ png_composite(palette[i].blue, palette[i].blue,
+ png_ptr->trans_alpha[i], back.blue);
+ }
+ }
+
+ png_ptr->transformations &= ~PNG_COMPOSE;
+ }
+#endif /* READ_BACKGROUND */
+
+#ifdef PNG_READ_SHIFT_SUPPORTED
+ if ((png_ptr->transformations & PNG_SHIFT) != 0 &&
+ (png_ptr->transformations & PNG_EXPAND) == 0 &&
+ (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE))
+ {
+ int i;
+ int istop = png_ptr->num_palette;
+ int shift = 8 - png_ptr->sig_bit.red;
+
+ png_ptr->transformations &= ~PNG_SHIFT;
+
+ /* significant bits can be in the range 1 to 7 for a meaninful result, if
+ * the number of significant bits is 0 then no shift is done (this is an
+ * error condition which is silently ignored.)
+ */
+ if (shift > 0 && shift < 8)
+ for (i=0; i<istop; ++i)
+ {
+ int component = png_ptr->palette[i].red;
+
+ component >>= shift;
+ png_ptr->palette[i].red = (png_byte)component;
+ }
+
+ shift = 8 - png_ptr->sig_bit.green;
+ if (shift > 0 && shift < 8)
+ for (i=0; i<istop; ++i)
+ {
+ int component = png_ptr->palette[i].green;
+
+ component >>= shift;
+ png_ptr->palette[i].green = (png_byte)component;
+ }
+
+ shift = 8 - png_ptr->sig_bit.blue;
+ if (shift > 0 && shift < 8)
+ for (i=0; i<istop; ++i)
+ {
+ int component = png_ptr->palette[i].blue;
+
+ component >>= shift;
+ png_ptr->palette[i].blue = (png_byte)component;
+ }
+ }
+#endif /* READ_SHIFT */
+}
+
+/* Modify the info structure to reflect the transformations. The
+ * info should be updated so a PNG file could be written with it,
+ * assuming the transformations result in valid PNG data.
+ */
+void /* PRIVATE */
+png_read_transform_info(png_structrp png_ptr, png_inforp info_ptr)
+{
+ png_debug(1, "in png_read_transform_info");
+
+#ifdef PNG_READ_EXPAND_SUPPORTED
+ if ((png_ptr->transformations & PNG_EXPAND) != 0)
+ {
+ if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+ {
+ /* This check must match what actually happens in
+ * png_do_expand_palette; if it ever checks the tRNS chunk to see if
+ * it is all opaque we must do the same (at present it does not.)
+ */
+ if (png_ptr->num_trans > 0)
+ info_ptr->color_type = PNG_COLOR_TYPE_RGB_ALPHA;
+
+ else
+ info_ptr->color_type = PNG_COLOR_TYPE_RGB;
+
+ info_ptr->bit_depth = 8;
+ info_ptr->num_trans = 0;
+
+ if (png_ptr->palette == NULL)
+ png_error (png_ptr, "Palette is NULL in indexed image");
+ }
+ else
+ {
+ if (png_ptr->num_trans != 0)
+ {
+ if ((png_ptr->transformations & PNG_EXPAND_tRNS) != 0)
+ info_ptr->color_type |= PNG_COLOR_MASK_ALPHA;
+ }
+ if (info_ptr->bit_depth < 8)
+ info_ptr->bit_depth = 8;
+
+ info_ptr->num_trans = 0;
+ }
+ }
+#endif
+
+#if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\
+ defined(PNG_READ_ALPHA_MODE_SUPPORTED)
+ /* The following is almost certainly wrong unless the background value is in
+ * the screen space!
+ */
+ if ((png_ptr->transformations & PNG_COMPOSE) != 0)
+ info_ptr->background = png_ptr->background;
+#endif
+
+#ifdef PNG_READ_GAMMA_SUPPORTED
+ /* The following used to be conditional on PNG_GAMMA (prior to 1.5.4),
+ * however it seems that the code in png_init_read_transformations, which has
+ * been called before this from png_read_update_info->png_read_start_row
+ * sometimes does the gamma transform and cancels the flag.
+ *
+ * TODO: this looks wrong; the info_ptr should end up with a gamma equal to
+ * the screen_gamma value. The following probably results in weirdness if
+ * the info_ptr is used by the app after the rows have been read.
+ */
+ info_ptr->colorspace.gamma = png_ptr->colorspace.gamma;
+#endif
+
+ if (info_ptr->bit_depth == 16)
+ {
+# ifdef PNG_READ_16BIT_SUPPORTED
+# ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
+ if ((png_ptr->transformations & PNG_SCALE_16_TO_8) != 0)
+ info_ptr->bit_depth = 8;
+# endif
+
+# ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
+ if ((png_ptr->transformations & PNG_16_TO_8) != 0)
+ info_ptr->bit_depth = 8;
+# endif
+
+# else
+ /* No 16-bit support: force chopping 16-bit input down to 8, in this case
+ * the app program can chose if both APIs are available by setting the
+ * correct scaling to use.
+ */
+# ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
+ /* For compatibility with previous versions use the strip method by
+ * default. This code works because if PNG_SCALE_16_TO_8 is already
+ * set the code below will do that in preference to the chop.
+ */
+ png_ptr->transformations |= PNG_16_TO_8;
+ info_ptr->bit_depth = 8;
+# else
+
+# ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
+ png_ptr->transformations |= PNG_SCALE_16_TO_8;
+ info_ptr->bit_depth = 8;
+# else
+
+ CONFIGURATION ERROR: you must enable at least one 16 to 8 method
+# endif
+# endif
+#endif /* !READ_16BIT */
+ }
+
+#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
+ if ((png_ptr->transformations & PNG_GRAY_TO_RGB) != 0)
+ info_ptr->color_type = (png_byte)(info_ptr->color_type |
+ PNG_COLOR_MASK_COLOR);
+#endif
+
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+ if ((png_ptr->transformations & PNG_RGB_TO_GRAY) != 0)
+ info_ptr->color_type = (png_byte)(info_ptr->color_type &
+ ~PNG_COLOR_MASK_COLOR);
+#endif
+
+#ifdef PNG_READ_QUANTIZE_SUPPORTED
+ if ((png_ptr->transformations & PNG_QUANTIZE) != 0)
+ {
+ if (((info_ptr->color_type == PNG_COLOR_TYPE_RGB) ||
+ (info_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA)) &&
+ png_ptr->palette_lookup != 0 && info_ptr->bit_depth == 8)
+ {
+ info_ptr->color_type = PNG_COLOR_TYPE_PALETTE;
+ }
+ }
+#endif
+
+#ifdef PNG_READ_EXPAND_16_SUPPORTED
+ if ((png_ptr->transformations & PNG_EXPAND_16) != 0 &&
+ info_ptr->bit_depth == 8 &&
+ info_ptr->color_type != PNG_COLOR_TYPE_PALETTE)
+ {
+ info_ptr->bit_depth = 16;
+ }
+#endif
+
+#ifdef PNG_READ_PACK_SUPPORTED
+ if ((png_ptr->transformations & PNG_PACK) != 0 &&
+ (info_ptr->bit_depth < 8))
+ info_ptr->bit_depth = 8;
+#endif
+
+ if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+ info_ptr->channels = 1;
+
+ else if ((info_ptr->color_type & PNG_COLOR_MASK_COLOR) != 0)
+ info_ptr->channels = 3;
+
+ else
+ info_ptr->channels = 1;
+
+#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
+ if ((png_ptr->transformations & PNG_STRIP_ALPHA) != 0)
+ {
+ info_ptr->color_type = (png_byte)(info_ptr->color_type &
+ ~PNG_COLOR_MASK_ALPHA);
+ info_ptr->num_trans = 0;
+ }
+#endif
+
+ if ((info_ptr->color_type & PNG_COLOR_MASK_ALPHA) != 0)
+ info_ptr->channels++;
+
+#ifdef PNG_READ_FILLER_SUPPORTED
+ /* STRIP_ALPHA and FILLER allowed: MASK_ALPHA bit stripped above */
+ if ((png_ptr->transformations & PNG_FILLER) != 0 &&
+ (info_ptr->color_type == PNG_COLOR_TYPE_RGB ||
+ info_ptr->color_type == PNG_COLOR_TYPE_GRAY))
+ {
+ info_ptr->channels++;
+ /* If adding a true alpha channel not just filler */
+ if ((png_ptr->transformations & PNG_ADD_ALPHA) != 0)
+ info_ptr->color_type |= PNG_COLOR_MASK_ALPHA;
+ }
+#endif
+
+#if defined(PNG_USER_TRANSFORM_PTR_SUPPORTED) && \
+defined(PNG_READ_USER_TRANSFORM_SUPPORTED)
+ if ((png_ptr->transformations & PNG_USER_TRANSFORM) != 0)
+ {
+ if (png_ptr->user_transform_depth != 0)
+ info_ptr->bit_depth = png_ptr->user_transform_depth;
+
+ if (png_ptr->user_transform_channels != 0)
+ info_ptr->channels = png_ptr->user_transform_channels;
+ }
+#endif
+
+ info_ptr->pixel_depth = (png_byte)(info_ptr->channels *
+ info_ptr->bit_depth);
+
+ info_ptr->rowbytes = PNG_ROWBYTES(info_ptr->pixel_depth, info_ptr->width);
+
+ /* Adding in 1.5.4: cache the above value in png_struct so that we can later
+ * check in png_rowbytes that the user buffer won't get overwritten. Note
+ * that the field is not always set - if png_read_update_info isn't called
+ * the application has to either not do any transforms or get the calculation
+ * right itself.
+ */
+ png_ptr->info_rowbytes = info_ptr->rowbytes;
+
+#ifndef PNG_READ_EXPAND_SUPPORTED
+ if (png_ptr != NULL)
+ return;
+#endif
+}
+
+#ifdef PNG_READ_PACK_SUPPORTED
+/* Unpack pixels of 1, 2, or 4 bits per pixel into 1 byte per pixel,
+ * without changing the actual values. Thus, if you had a row with
+ * a bit depth of 1, you would end up with bytes that only contained
+ * the numbers 0 or 1. If you would rather they contain 0 and 255, use
+ * png_do_shift() after this.
+ */
+static void
+png_do_unpack(png_row_infop row_info, png_bytep row)
+{
+ png_debug(1, "in png_do_unpack");
+
+ if (row_info->bit_depth < 8)
+ {
+ png_uint_32 i;
+ png_uint_32 row_width=row_info->width;
+
+ switch (row_info->bit_depth)
+ {
+ case 1:
+ {
+ png_bytep sp = row + (png_size_t)((row_width - 1) >> 3);
+ png_bytep dp = row + (png_size_t)row_width - 1;
+ png_uint_32 shift = 7 - (int)((row_width + 7) & 0x07);
+ for (i = 0; i < row_width; i++)
+ {
+ *dp = (png_byte)((*sp >> shift) & 0x01);
+
+ if (shift == 7)
+ {
+ shift = 0;
+ sp--;
+ }
+
+ else
+ shift++;
+
+ dp--;
+ }
+ break;
+ }
+
+ case 2:
+ {
+
+ png_bytep sp = row + (png_size_t)((row_width - 1) >> 2);
+ png_bytep dp = row + (png_size_t)row_width - 1;
+ png_uint_32 shift = (int)((3 - ((row_width + 3) & 0x03)) << 1);
+ for (i = 0; i < row_width; i++)
+ {
+ *dp = (png_byte)((*sp >> shift) & 0x03);
+
+ if (shift == 6)
+ {
+ shift = 0;
+ sp--;
+ }
+
+ else
+ shift += 2;
+
+ dp--;
+ }
+ break;
+ }
+
+ case 4:
+ {
+ png_bytep sp = row + (png_size_t)((row_width - 1) >> 1);
+ png_bytep dp = row + (png_size_t)row_width - 1;
+ png_uint_32 shift = (int)((1 - ((row_width + 1) & 0x01)) << 2);
+ for (i = 0; i < row_width; i++)
+ {
+ *dp = (png_byte)((*sp >> shift) & 0x0f);
+
+ if (shift == 4)
+ {
+ shift = 0;
+ sp--;
+ }
+
+ else
+ shift = 4;
+
+ dp--;
+ }
+ break;
+ }
+
+ default:
+ break;
+ }
+ row_info->bit_depth = 8;
+ row_info->pixel_depth = (png_byte)(8 * row_info->channels);
+ row_info->rowbytes = row_width * row_info->channels;
+ }
+}
+#endif
+
+#ifdef PNG_READ_SHIFT_SUPPORTED
+/* Reverse the effects of png_do_shift. This routine merely shifts the
+ * pixels back to their significant bits values. Thus, if you have
+ * a row of bit depth 8, but only 5 are significant, this will shift
+ * the values back to 0 through 31.
+ */
+static void
+png_do_unshift(png_row_infop row_info, png_bytep row,
+ png_const_color_8p sig_bits)
+{
+ int color_type;
+
+ png_debug(1, "in png_do_unshift");
+
+ /* The palette case has already been handled in the _init routine. */
+ color_type = row_info->color_type;
+
+ if (color_type != PNG_COLOR_TYPE_PALETTE)
+ {
+ int shift[4];
+ int channels = 0;
+ int bit_depth = row_info->bit_depth;
+
+ if ((color_type & PNG_COLOR_MASK_COLOR) != 0)
+ {
+ shift[channels++] = bit_depth - sig_bits->red;
+ shift[channels++] = bit_depth - sig_bits->green;
+ shift[channels++] = bit_depth - sig_bits->blue;
+ }
+
+ else
+ {
+ shift[channels++] = bit_depth - sig_bits->gray;
+ }
+
+ if ((color_type & PNG_COLOR_MASK_ALPHA) != 0)
+ {
+ shift[channels++] = bit_depth - sig_bits->alpha;
+ }
+
+ {
+ int c, have_shift;
+
+ for (c = have_shift = 0; c < channels; ++c)
+ {
+ /* A shift of more than the bit depth is an error condition but it
+ * gets ignored here.
+ */
+ if (shift[c] <= 0 || shift[c] >= bit_depth)
+ shift[c] = 0;
+
+ else
+ have_shift = 1;
+ }
+
+ if (have_shift == 0)
+ return;
+ }
+
+ switch (bit_depth)
+ {
+ default:
+ /* Must be 1bpp gray: should not be here! */
+ /* NOTREACHED */
+ break;
+
+ case 2:
+ /* Must be 2bpp gray */
+ /* assert(channels == 1 && shift[0] == 1) */
+ {
+ png_bytep bp = row;
+ png_bytep bp_end = bp + row_info->rowbytes;
+
+ while (bp < bp_end)
+ {
+ int b = (*bp >> 1) & 0x55;
+ *bp++ = (png_byte)b;
+ }
+ break;
+ }
+
+ case 4:
+ /* Must be 4bpp gray */
+ /* assert(channels == 1) */
+ {
+ png_bytep bp = row;
+ png_bytep bp_end = bp + row_info->rowbytes;
+ int gray_shift = shift[0];
+ int mask = 0xf >> gray_shift;
+
+ mask |= mask << 4;
+
+ while (bp < bp_end)
+ {
+ int b = (*bp >> gray_shift) & mask;
+ *bp++ = (png_byte)b;
+ }
+ break;
+ }
+
+ case 8:
+ /* Single byte components, G, GA, RGB, RGBA */
+ {
+ png_bytep bp = row;
+ png_bytep bp_end = bp + row_info->rowbytes;
+ int channel = 0;
+
+ while (bp < bp_end)
+ {
+ int b = *bp >> shift[channel];
+ if (++channel >= channels)
+ channel = 0;
+ *bp++ = (png_byte)b;
+ }
+ break;
+ }
+
+#ifdef PNG_READ_16BIT_SUPPORTED
+ case 16:
+ /* Double byte components, G, GA, RGB, RGBA */
+ {
+ png_bytep bp = row;
+ png_bytep bp_end = bp + row_info->rowbytes;
+ int channel = 0;
+
+ while (bp < bp_end)
+ {
+ int value = (bp[0] << 8) + bp[1];
+
+ value >>= shift[channel];
+ if (++channel >= channels)
+ channel = 0;
+ *bp++ = (png_byte)(value >> 8);
+ *bp++ = (png_byte)value;
+ }
+ break;
+ }
+#endif
+ }
+ }
+}
+#endif
+
+#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
+/* Scale rows of bit depth 16 down to 8 accurately */
+static void
+png_do_scale_16_to_8(png_row_infop row_info, png_bytep row)
+{
+ png_debug(1, "in png_do_scale_16_to_8");
+
+ if (row_info->bit_depth == 16)
+ {
+ png_bytep sp = row; /* source */
+ png_bytep dp = row; /* destination */
+ png_bytep ep = sp + row_info->rowbytes; /* end+1 */
+
+ while (sp < ep)
+ {
+ /* The input is an array of 16-bit components, these must be scaled to
+ * 8 bits each. For a 16-bit value V the required value (from the PNG
+ * specification) is:
+ *
+ * (V * 255) / 65535
+ *
+ * This reduces to round(V / 257), or floor((V + 128.5)/257)
+ *
+ * Represent V as the two byte value vhi.vlo. Make a guess that the
+ * result is the top byte of V, vhi, then the correction to this value
+ * is:
+ *
+ * error = floor(((V-vhi.vhi) + 128.5) / 257)
+ * = floor(((vlo-vhi) + 128.5) / 257)
+ *
+ * This can be approximated using integer arithmetic (and a signed
+ * shift):
+ *
+ * error = (vlo-vhi+128) >> 8;
+ *
+ * The approximate differs from the exact answer only when (vlo-vhi) is
+ * 128; it then gives a correction of +1 when the exact correction is
+ * 0. This gives 128 errors. The exact answer (correct for all 16-bit
+ * input values) is:
+ *
+ * error = (vlo-vhi+128)*65535 >> 24;
+ *
+ * An alternative arithmetic calculation which also gives no errors is:
+ *
+ * (V * 255 + 32895) >> 16
+ */
+
+ png_int_32 tmp = *sp++; /* must be signed! */
+ tmp += (((int)*sp++ - tmp + 128) * 65535) >> 24;
+ *dp++ = (png_byte)tmp;
+ }
+
+ row_info->bit_depth = 8;
+ row_info->pixel_depth = (png_byte)(8 * row_info->channels);
+ row_info->rowbytes = row_info->width * row_info->channels;
+ }
+}
+#endif
+
+#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
+static void
+/* Simply discard the low byte. This was the default behavior prior
+ * to libpng-1.5.4.
+ */
+png_do_chop(png_row_infop row_info, png_bytep row)
+{
+ png_debug(1, "in png_do_chop");
+
+ if (row_info->bit_depth == 16)
+ {
+ png_bytep sp = row; /* source */
+ png_bytep dp = row; /* destination */
+ png_bytep ep = sp + row_info->rowbytes; /* end+1 */
+
+ while (sp < ep)
+ {
+ *dp++ = *sp;
+ sp += 2; /* skip low byte */
+ }
+
+ row_info->bit_depth = 8;
+ row_info->pixel_depth = (png_byte)(8 * row_info->channels);
+ row_info->rowbytes = row_info->width * row_info->channels;
+ }
+}
+#endif
+
+#ifdef PNG_READ_SWAP_ALPHA_SUPPORTED
+static void
+png_do_read_swap_alpha(png_row_infop row_info, png_bytep row)
+{
+ png_debug(1, "in png_do_read_swap_alpha");
+
+ {
+ png_uint_32 row_width = row_info->width;
+ if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+ {
+ /* This converts from RGBA to ARGB */
+ if (row_info->bit_depth == 8)
+ {
+ png_bytep sp = row + row_info->rowbytes;
+ png_bytep dp = sp;
+ png_byte save;
+ png_uint_32 i;
+
+ for (i = 0; i < row_width; i++)
+ {
+ save = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = save;
+ }
+ }
+
+#ifdef PNG_READ_16BIT_SUPPORTED
+ /* This converts from RRGGBBAA to AARRGGBB */
+ else
+ {
+ png_bytep sp = row + row_info->rowbytes;
+ png_bytep dp = sp;
+ png_byte save[2];
+ png_uint_32 i;
+
+ for (i = 0; i < row_width; i++)
+ {
+ save[0] = *(--sp);
+ save[1] = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = save[0];
+ *(--dp) = save[1];
+ }
+ }
+#endif
+ }
+
+ else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+ {
+ /* This converts from GA to AG */
+ if (row_info->bit_depth == 8)
+ {
+ png_bytep sp = row + row_info->rowbytes;
+ png_bytep dp = sp;
+ png_byte save;
+ png_uint_32 i;
+
+ for (i = 0; i < row_width; i++)
+ {
+ save = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = save;
+ }
+ }
+
+#ifdef PNG_READ_16BIT_SUPPORTED
+ /* This converts from GGAA to AAGG */
+ else
+ {
+ png_bytep sp = row + row_info->rowbytes;
+ png_bytep dp = sp;
+ png_byte save[2];
+ png_uint_32 i;
+
+ for (i = 0; i < row_width; i++)
+ {
+ save[0] = *(--sp);
+ save[1] = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = save[0];
+ *(--dp) = save[1];
+ }
+ }
+#endif
+ }
+ }
+}
+#endif
+
+#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED
+static void
+png_do_read_invert_alpha(png_row_infop row_info, png_bytep row)
+{
+ png_uint_32 row_width;
+ png_debug(1, "in png_do_read_invert_alpha");
+
+ row_width = row_info->width;
+ if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+ {
+ if (row_info->bit_depth == 8)
+ {
+ /* This inverts the alpha channel in RGBA */
+ png_bytep sp = row + row_info->rowbytes;
+ png_bytep dp = sp;
+ png_uint_32 i;
+
+ for (i = 0; i < row_width; i++)
+ {
+ *(--dp) = (png_byte)(255 - *(--sp));
+
+/* This does nothing:
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ We can replace it with:
+*/
+ sp-=3;
+ dp=sp;
+ }
+ }
+
+#ifdef PNG_READ_16BIT_SUPPORTED
+ /* This inverts the alpha channel in RRGGBBAA */
+ else
+ {
+ png_bytep sp = row + row_info->rowbytes;
+ png_bytep dp = sp;
+ png_uint_32 i;
+
+ for (i = 0; i < row_width; i++)
+ {
+ *(--dp) = (png_byte)(255 - *(--sp));
+ *(--dp) = (png_byte)(255 - *(--sp));
+
+/* This does nothing:
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ We can replace it with:
+*/
+ sp-=6;
+ dp=sp;
+ }
+ }
+#endif
+ }
+ else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+ {
+ if (row_info->bit_depth == 8)
+ {
+ /* This inverts the alpha channel in GA */
+ png_bytep sp = row + row_info->rowbytes;
+ png_bytep dp = sp;
+ png_uint_32 i;
+
+ for (i = 0; i < row_width; i++)
+ {
+ *(--dp) = (png_byte)(255 - *(--sp));
+ *(--dp) = *(--sp);
+ }
+ }
+
+#ifdef PNG_READ_16BIT_SUPPORTED
+ else
+ {
+ /* This inverts the alpha channel in GGAA */
+ png_bytep sp = row + row_info->rowbytes;
+ png_bytep dp = sp;
+ png_uint_32 i;
+
+ for (i = 0; i < row_width; i++)
+ {
+ *(--dp) = (png_byte)(255 - *(--sp));
+ *(--dp) = (png_byte)(255 - *(--sp));
+/*
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+*/
+ sp-=2;
+ dp=sp;
+ }
+ }
+#endif
+ }
+}
+#endif
+
+#ifdef PNG_READ_FILLER_SUPPORTED
+/* Add filler channel if we have RGB color */
+static void
+png_do_read_filler(png_row_infop row_info, png_bytep row,
+ png_uint_32 filler, png_uint_32 flags)
+{
+ png_uint_32 i;
+ png_uint_32 row_width = row_info->width;
+
+#ifdef PNG_READ_16BIT_SUPPORTED
+ png_byte hi_filler = (png_byte)(filler>>8);
+#endif
+ png_byte lo_filler = (png_byte)filler;
+
+ png_debug(1, "in png_do_read_filler");
+
+ if (
+ row_info->color_type == PNG_COLOR_TYPE_GRAY)
+ {
+ if (row_info->bit_depth == 8)
+ {
+ if ((flags & PNG_FLAG_FILLER_AFTER) != 0)
+ {
+ /* This changes the data from G to GX */
+ png_bytep sp = row + (png_size_t)row_width;
+ png_bytep dp = sp + (png_size_t)row_width;
+ for (i = 1; i < row_width; i++)
+ {
+ *(--dp) = lo_filler;
+ *(--dp) = *(--sp);
+ }
+ *(--dp) = lo_filler;
+ row_info->channels = 2;
+ row_info->pixel_depth = 16;
+ row_info->rowbytes = row_width * 2;
+ }
+
+ else
+ {
+ /* This changes the data from G to XG */
+ png_bytep sp = row + (png_size_t)row_width;
+ png_bytep dp = sp + (png_size_t)row_width;
+ for (i = 0; i < row_width; i++)
+ {
+ *(--dp) = *(--sp);
+ *(--dp) = lo_filler;
+ }
+ row_info->channels = 2;
+ row_info->pixel_depth = 16;
+ row_info->rowbytes = row_width * 2;
+ }
+ }
+
+#ifdef PNG_READ_16BIT_SUPPORTED
+ else if (row_info->bit_depth == 16)
+ {
+ if ((flags & PNG_FLAG_FILLER_AFTER) != 0)
+ {
+ /* This changes the data from GG to GGXX */
+ png_bytep sp = row + (png_size_t)row_width * 2;
+ png_bytep dp = sp + (png_size_t)row_width * 2;
+ for (i = 1; i < row_width; i++)
+ {
+ *(--dp) = lo_filler;
+ *(--dp) = hi_filler;
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ }
+ *(--dp) = lo_filler;
+ *(--dp) = hi_filler;
+ row_info->channels = 2;
+ row_info->pixel_depth = 32;
+ row_info->rowbytes = row_width * 4;
+ }
+
+ else
+ {
+ /* This changes the data from GG to XXGG */
+ png_bytep sp = row + (png_size_t)row_width * 2;
+ png_bytep dp = sp + (png_size_t)row_width * 2;
+ for (i = 0; i < row_width; i++)
+ {
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = lo_filler;
+ *(--dp) = hi_filler;
+ }
+ row_info->channels = 2;
+ row_info->pixel_depth = 32;
+ row_info->rowbytes = row_width * 4;
+ }
+ }
+#endif
+ } /* COLOR_TYPE == GRAY */
+ else if (row_info->color_type == PNG_COLOR_TYPE_RGB)
+ {
+ if (row_info->bit_depth == 8)
+ {
+ if ((flags & PNG_FLAG_FILLER_AFTER) != 0)
+ {
+ /* This changes the data from RGB to RGBX */
+ png_bytep sp = row + (png_size_t)row_width * 3;
+ png_bytep dp = sp + (png_size_t)row_width;
+ for (i = 1; i < row_width; i++)
+ {
+ *(--dp) = lo_filler;
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ }
+ *(--dp) = lo_filler;
+ row_info->channels = 4;
+ row_info->pixel_depth = 32;
+ row_info->rowbytes = row_width * 4;
+ }
+
+ else
+ {
+ /* This changes the data from RGB to XRGB */
+ png_bytep sp = row + (png_size_t)row_width * 3;
+ png_bytep dp = sp + (png_size_t)row_width;
+ for (i = 0; i < row_width; i++)
+ {
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = lo_filler;
+ }
+ row_info->channels = 4;
+ row_info->pixel_depth = 32;
+ row_info->rowbytes = row_width * 4;
+ }
+ }
+
+#ifdef PNG_READ_16BIT_SUPPORTED
+ else if (row_info->bit_depth == 16)
+ {
+ if ((flags & PNG_FLAG_FILLER_AFTER) != 0)
+ {
+ /* This changes the data from RRGGBB to RRGGBBXX */
+ png_bytep sp = row + (png_size_t)row_width * 6;
+ png_bytep dp = sp + (png_size_t)row_width * 2;
+ for (i = 1; i < row_width; i++)
+ {
+ *(--dp) = lo_filler;
+ *(--dp) = hi_filler;
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ }
+ *(--dp) = lo_filler;
+ *(--dp) = hi_filler;
+ row_info->channels = 4;
+ row_info->pixel_depth = 64;
+ row_info->rowbytes = row_width * 8;
+ }
+
+ else
+ {
+ /* This changes the data from RRGGBB to XXRRGGBB */
+ png_bytep sp = row + (png_size_t)row_width * 6;
+ png_bytep dp = sp + (png_size_t)row_width * 2;
+ for (i = 0; i < row_width; i++)
+ {
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = lo_filler;
+ *(--dp) = hi_filler;
+ }
+
+ row_info->channels = 4;
+ row_info->pixel_depth = 64;
+ row_info->rowbytes = row_width * 8;
+ }
+ }
+#endif
+ } /* COLOR_TYPE == RGB */
+}
+#endif
+
+#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
+/* Expand grayscale files to RGB, with or without alpha */
+static void
+png_do_gray_to_rgb(png_row_infop row_info, png_bytep row)
+{
+ png_uint_32 i;
+ png_uint_32 row_width = row_info->width;
+
+ png_debug(1, "in png_do_gray_to_rgb");
+
+ if (row_info->bit_depth >= 8 &&
+ (row_info->color_type & PNG_COLOR_MASK_COLOR) == 0)
+ {
+ if (row_info->color_type == PNG_COLOR_TYPE_GRAY)
+ {
+ if (row_info->bit_depth == 8)
+ {
+ /* This changes G to RGB */
+ png_bytep sp = row + (png_size_t)row_width - 1;
+ png_bytep dp = sp + (png_size_t)row_width * 2;
+ for (i = 0; i < row_width; i++)
+ {
+ *(dp--) = *sp;
+ *(dp--) = *sp;
+ *(dp--) = *(sp--);
+ }
+ }
+
+ else
+ {
+ /* This changes GG to RRGGBB */
+ png_bytep sp = row + (png_size_t)row_width * 2 - 1;
+ png_bytep dp = sp + (png_size_t)row_width * 4;
+ for (i = 0; i < row_width; i++)
+ {
+ *(dp--) = *sp;
+ *(dp--) = *(sp - 1);
+ *(dp--) = *sp;
+ *(dp--) = *(sp - 1);
+ *(dp--) = *(sp--);
+ *(dp--) = *(sp--);
+ }
+ }
+ }
+
+ else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+ {
+ if (row_info->bit_depth == 8)
+ {
+ /* This changes GA to RGBA */
+ png_bytep sp = row + (png_size_t)row_width * 2 - 1;
+ png_bytep dp = sp + (png_size_t)row_width * 2;
+ for (i = 0; i < row_width; i++)
+ {
+ *(dp--) = *(sp--);
+ *(dp--) = *sp;
+ *(dp--) = *sp;
+ *(dp--) = *(sp--);
+ }
+ }
+
+ else
+ {
+ /* This changes GGAA to RRGGBBAA */
+ png_bytep sp = row + (png_size_t)row_width * 4 - 1;
+ png_bytep dp = sp + (png_size_t)row_width * 4;
+ for (i = 0; i < row_width; i++)
+ {
+ *(dp--) = *(sp--);
+ *(dp--) = *(sp--);
+ *(dp--) = *sp;
+ *(dp--) = *(sp - 1);
+ *(dp--) = *sp;
+ *(dp--) = *(sp - 1);
+ *(dp--) = *(sp--);
+ *(dp--) = *(sp--);
+ }
+ }
+ }
+ row_info->channels = (png_byte)(row_info->channels + 2);
+ row_info->color_type |= PNG_COLOR_MASK_COLOR;
+ row_info->pixel_depth = (png_byte)(row_info->channels *
+ row_info->bit_depth);
+ row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);
+ }
+}
+#endif
+
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+/* Reduce RGB files to grayscale, with or without alpha
+ * using the equation given in Poynton's ColorFAQ of 1998-01-04 at
+ * <http://www.inforamp.net/~poynton/> (THIS LINK IS DEAD June 2008 but
+ * versions dated 1998 through November 2002 have been archived at
+ * http://web.archive.org/web/20000816232553/http://www.inforamp.net/
+ * ~poynton/notes/colour_and_gamma/ColorFAQ.txt )
+ * Charles Poynton poynton at poynton.com
+ *
+ * Y = 0.212671 * R + 0.715160 * G + 0.072169 * B
+ *
+ * which can be expressed with integers as
+ *
+ * Y = (6969 * R + 23434 * G + 2365 * B)/32768
+ *
+ * Poynton's current link (as of January 2003 through July 2011):
+ * <http://www.poynton.com/notes/colour_and_gamma/>
+ * has changed the numbers slightly:
+ *
+ * Y = 0.2126*R + 0.7152*G + 0.0722*B
+ *
+ * which can be expressed with integers as
+ *
+ * Y = (6966 * R + 23436 * G + 2366 * B)/32768
+ *
+ * Historically, however, libpng uses numbers derived from the ITU-R Rec 709
+ * end point chromaticities and the D65 white point. Depending on the
+ * precision used for the D65 white point this produces a variety of different
+ * numbers, however if the four decimal place value used in ITU-R Rec 709 is
+ * used (0.3127,0.3290) the Y calculation would be:
+ *
+ * Y = (6968 * R + 23435 * G + 2366 * B)/32768
+ *
+ * While this is correct the rounding results in an overflow for white, because
+ * the sum of the rounded coefficients is 32769, not 32768. Consequently
+ * libpng uses, instead, the closest non-overflowing approximation:
+ *
+ * Y = (6968 * R + 23434 * G + 2366 * B)/32768
+ *
+ * Starting with libpng-1.5.5, if the image being converted has a cHRM chunk
+ * (including an sRGB chunk) then the chromaticities are used to calculate the
+ * coefficients. See the chunk handling in pngrutil.c for more information.
+ *
+ * In all cases the calculation is to be done in a linear colorspace. If no
+ * gamma information is available to correct the encoding of the original RGB
+ * values this results in an implicit assumption that the original PNG RGB
+ * values were linear.
+ *
+ * Other integer coefficents can be used via png_set_rgb_to_gray(). Because
+ * the API takes just red and green coefficients the blue coefficient is
+ * calculated to make the sum 32768. This will result in different rounding
+ * to that used above.
+ */
+static int
+png_do_rgb_to_gray(png_structrp png_ptr, png_row_infop row_info, png_bytep row)
+
+{
+ int rgb_error = 0;
+
+ png_debug(1, "in png_do_rgb_to_gray");
+
+ if ((row_info->color_type & PNG_COLOR_MASK_PALETTE) == 0 &&
+ (row_info->color_type & PNG_COLOR_MASK_COLOR) != 0)
+ {
+ PNG_CONST png_uint_32 rc = png_ptr->rgb_to_gray_red_coeff;
+ PNG_CONST png_uint_32 gc = png_ptr->rgb_to_gray_green_coeff;
+ PNG_CONST png_uint_32 bc = 32768 - rc - gc;
+ PNG_CONST png_uint_32 row_width = row_info->width;
+ PNG_CONST int have_alpha =
+ (row_info->color_type & PNG_COLOR_MASK_ALPHA) != 0;
+
+ if (row_info->bit_depth == 8)
+ {
+#ifdef PNG_READ_GAMMA_SUPPORTED
+ /* Notice that gamma to/from 1 are not necessarily inverses (if
+ * there is an overall gamma correction). Prior to 1.5.5 this code
+ * checked the linearized values for equality; this doesn't match
+ * the documentation, the original values must be checked.
+ */
+ if (png_ptr->gamma_from_1 != NULL && png_ptr->gamma_to_1 != NULL)
+ {
+ png_bytep sp = row;
+ png_bytep dp = row;
+ png_uint_32 i;
+
+ for (i = 0; i < row_width; i++)
+ {
+ png_byte red = *(sp++);
+ png_byte green = *(sp++);
+ png_byte blue = *(sp++);
+
+ if (red != green || red != blue)
+ {
+ red = png_ptr->gamma_to_1[red];
+ green = png_ptr->gamma_to_1[green];
+ blue = png_ptr->gamma_to_1[blue];
+
+ rgb_error |= 1;
+ *(dp++) = png_ptr->gamma_from_1[
+ (rc*red + gc*green + bc*blue + 16384)>>15];
+ }
+
+ else
+ {
+ /* If there is no overall correction the table will not be
+ * set.
+ */
+ if (png_ptr->gamma_table != NULL)
+ red = png_ptr->gamma_table[red];
+
+ *(dp++) = red;
+ }
+
+ if (have_alpha != 0)
+ *(dp++) = *(sp++);
+ }
+ }
+ else
+#endif
+ {
+ png_bytep sp = row;
+ png_bytep dp = row;
+ png_uint_32 i;
+
+ for (i = 0; i < row_width; i++)
+ {
+ png_byte red = *(sp++);
+ png_byte green = *(sp++);
+ png_byte blue = *(sp++);
+
+ if (red != green || red != blue)
+ {
+ rgb_error |= 1;
+ /* NOTE: this is the historical approach which simply
+ * truncates the results.
+ */
+ *(dp++) = (png_byte)((rc*red + gc*green + bc*blue)>>15);
+ }
+
+ else
+ *(dp++) = red;
+
+ if (have_alpha != 0)
+ *(dp++) = *(sp++);
+ }
+ }
+ }
+
+ else /* RGB bit_depth == 16 */
+ {
+#ifdef PNG_READ_GAMMA_SUPPORTED
+ if (png_ptr->gamma_16_to_1 != NULL && png_ptr->gamma_16_from_1 != NULL)
+ {
+ png_bytep sp = row;
+ png_bytep dp = row;
+ png_uint_32 i;
+
+ for (i = 0; i < row_width; i++)
+ {
+ png_uint_16 red, green, blue, w;
+ png_byte hi,lo;
+
+ hi=*(sp)++; lo=*(sp)++; red = (png_uint_16)((hi << 8) | (lo));
+ hi=*(sp)++; lo=*(sp)++; green = (png_uint_16)((hi << 8) | (lo));
+ hi=*(sp)++; lo=*(sp)++; blue = (png_uint_16)((hi << 8) | (lo));
+
+ if (red == green && red == blue)
+ {
+ if (png_ptr->gamma_16_table != NULL)
+ w = png_ptr->gamma_16_table[(red & 0xff)
+ >> png_ptr->gamma_shift][red >> 8];
+
+ else
+ w = red;
+ }
+
+ else
+ {
+ png_uint_16 red_1 = png_ptr->gamma_16_to_1[(red & 0xff)
+ >> png_ptr->gamma_shift][red>>8];
+ png_uint_16 green_1 =
+ png_ptr->gamma_16_to_1[(green & 0xff) >>
+ png_ptr->gamma_shift][green>>8];
+ png_uint_16 blue_1 = png_ptr->gamma_16_to_1[(blue & 0xff)
+ >> png_ptr->gamma_shift][blue>>8];
+ png_uint_16 gray16 = (png_uint_16)((rc*red_1 + gc*green_1
+ + bc*blue_1 + 16384)>>15);
+ w = png_ptr->gamma_16_from_1[(gray16 & 0xff) >>
+ png_ptr->gamma_shift][gray16 >> 8];
+ rgb_error |= 1;
+ }
+
+ *(dp++) = (png_byte)((w>>8) & 0xff);
+ *(dp++) = (png_byte)(w & 0xff);
+
+ if (have_alpha != 0)
+ {
+ *(dp++) = *(sp++);
+ *(dp++) = *(sp++);
+ }
+ }
+ }
+ else
+#endif
+ {
+ png_bytep sp = row;
+ png_bytep dp = row;
+ png_uint_32 i;
+
+ for (i = 0; i < row_width; i++)
+ {
+ png_uint_16 red, green, blue, gray16;
+ png_byte hi,lo;
+
+ hi=*(sp)++; lo=*(sp)++; red = (png_uint_16)((hi << 8) | (lo));
+ hi=*(sp)++; lo=*(sp)++; green = (png_uint_16)((hi << 8) | (lo));
+ hi=*(sp)++; lo=*(sp)++; blue = (png_uint_16)((hi << 8) | (lo));
+
+ if (red != green || red != blue)
+ rgb_error |= 1;
+
+ /* From 1.5.5 in the 16-bit case do the accurate conversion even
+ * in the 'fast' case - this is because this is where the code
+ * ends up when handling linear 16-bit data.
+ */
+ gray16 = (png_uint_16)((rc*red + gc*green + bc*blue + 16384) >>
+ 15);
+ *(dp++) = (png_byte)((gray16 >> 8) & 0xff);
+ *(dp++) = (png_byte)(gray16 & 0xff);
+
+ if (have_alpha != 0)
+ {
+ *(dp++) = *(sp++);
+ *(dp++) = *(sp++);
+ }
+ }
+ }
+ }
+
+ row_info->channels = (png_byte)(row_info->channels - 2);
+ row_info->color_type = (png_byte)(row_info->color_type &
+ ~PNG_COLOR_MASK_COLOR);
+ row_info->pixel_depth = (png_byte)(row_info->channels *
+ row_info->bit_depth);
+ row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);
+ }
+ return rgb_error;
+}
+#endif
+
+#if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\
+ defined(PNG_READ_ALPHA_MODE_SUPPORTED)
+/* Replace any alpha or transparency with the supplied background color.
+ * "background" is already in the screen gamma, while "background_1" is
+ * at a gamma of 1.0. Paletted files have already been taken care of.
+ */
+static void
+png_do_compose(png_row_infop row_info, png_bytep row, png_structrp png_ptr)
+{
+#ifdef PNG_READ_GAMMA_SUPPORTED
+ png_const_bytep gamma_table = png_ptr->gamma_table;
+ png_const_bytep gamma_from_1 = png_ptr->gamma_from_1;
+ png_const_bytep gamma_to_1 = png_ptr->gamma_to_1;
+ png_const_uint_16pp gamma_16 = png_ptr->gamma_16_table;
+ png_const_uint_16pp gamma_16_from_1 = png_ptr->gamma_16_from_1;
+ png_const_uint_16pp gamma_16_to_1 = png_ptr->gamma_16_to_1;
+ int gamma_shift = png_ptr->gamma_shift;
+ int optimize = (png_ptr->flags & PNG_FLAG_OPTIMIZE_ALPHA) != 0;
+#endif
+
+ png_bytep sp;
+ png_uint_32 i;
+ png_uint_32 row_width = row_info->width;
+ int shift;
+
+ png_debug(1, "in png_do_compose");
+
+ {
+ switch (row_info->color_type)
+ {
+ case PNG_COLOR_TYPE_GRAY:
+ {
+ switch (row_info->bit_depth)
+ {
+ case 1:
+ {
+ sp = row;
+ shift = 7;
+ for (i = 0; i < row_width; i++)
+ {
+ if ((png_uint_16)((*sp >> shift) & 0x01)
+ == png_ptr->trans_color.gray)
+ {
+ unsigned int tmp = *sp & (0x7f7f >> (7 - shift));
+ tmp |= png_ptr->background.gray << shift;
+ *sp = (png_byte)(tmp & 0xff);
+ }
+
+ if (shift == 0)
+ {
+ shift = 7;
+ sp++;
+ }
+
+ else
+ shift--;
+ }
+ break;
+ }
+
+ case 2:
+ {
+#ifdef PNG_READ_GAMMA_SUPPORTED
+ if (gamma_table != NULL)
+ {
+ sp = row;
+ shift = 6;
+ for (i = 0; i < row_width; i++)
+ {
+ if ((png_uint_16)((*sp >> shift) & 0x03)
+ == png_ptr->trans_color.gray)
+ {
+ unsigned int tmp = *sp & (0x3f3f >> (6 - shift));
+ tmp |= png_ptr->background.gray << shift;
+ *sp = (png_byte)(tmp & 0xff);
+ }
+
+ else
+ {
+ unsigned int p = (*sp >> shift) & 0x03;
+ unsigned int g = (gamma_table [p | (p << 2) |
+ (p << 4) | (p << 6)] >> 6) & 0x03;
+ unsigned int tmp = *sp & (0x3f3f >> (6 - shift));
+ tmp |= g << shift;
+ *sp = (png_byte)(tmp & 0xff);
+ }
+
+ if (shift == 0)
+ {
+ shift = 6;
+ sp++;
+ }
+
+ else
+ shift -= 2;
+ }
+ }
+
+ else
+#endif
+ {
+ sp = row;
+ shift = 6;
+ for (i = 0; i < row_width; i++)
+ {
+ if ((png_uint_16)((*sp >> shift) & 0x03)
+ == png_ptr->trans_color.gray)
+ {
+ unsigned int tmp = *sp & (0x3f3f >> (6 - shift));
+ tmp |= png_ptr->background.gray << shift;
+ *sp = (png_byte)(tmp & 0xff);
+ }
+
+ if (shift == 0)
+ {
+ shift = 6;
+ sp++;
+ }
+
+ else
+ shift -= 2;
+ }
+ }
+ break;
+ }
+
+ case 4:
+ {
+#ifdef PNG_READ_GAMMA_SUPPORTED
+ if (gamma_table != NULL)
+ {
+ sp = row;
+ shift = 4;
+ for (i = 0; i < row_width; i++)
+ {
+ if ((png_uint_16)((*sp >> shift) & 0x0f)
+ == png_ptr->trans_color.gray)
+ {
+ unsigned int tmp = *sp & (0x0f0f >> (4 - shift));
+ tmp |= png_ptr->background.gray << shift;
+ *sp = (png_byte)(tmp & 0xff);
+ }
+
+ else
+ {
+ unsigned int p = (*sp >> shift) & 0x0f;
+ unsigned int g = (gamma_table[p | (p << 4)] >> 4) &
+ 0x0f;
+ unsigned int tmp = *sp & (0x0f0f >> (4 - shift));
+ tmp |= g << shift;
+ *sp = (png_byte)(tmp & 0xff);
+ }
+
+ if (shift == 0)
+ {
+ shift = 4;
+ sp++;
+ }
+
+ else
+ shift -= 4;
+ }
+ }
+
+ else
+#endif
+ {
+ sp = row;
+ shift = 4;
+ for (i = 0; i < row_width; i++)
+ {
+ if ((png_uint_16)((*sp >> shift) & 0x0f)
+ == png_ptr->trans_color.gray)
+ {
+ unsigned int tmp = *sp & (0x0f0f >> (4 - shift));
+ tmp |= png_ptr->background.gray << shift;
+ *sp = (png_byte)(tmp & 0xff);
+ }
+
+ if (shift == 0)
+ {
+ shift = 4;
+ sp++;
+ }
+
+ else
+ shift -= 4;
+ }
+ }
+ break;
+ }
+
+ case 8:
+ {
+#ifdef PNG_READ_GAMMA_SUPPORTED
+ if (gamma_table != NULL)
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++, sp++)
+ {
+ if (*sp == png_ptr->trans_color.gray)
+ *sp = (png_byte)png_ptr->background.gray;
+
+ else
+ *sp = gamma_table[*sp];
+ }
+ }
+ else
+#endif
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++, sp++)
+ {
+ if (*sp == png_ptr->trans_color.gray)
+ *sp = (png_byte)png_ptr->background.gray;
+ }
+ }
+ break;
+ }
+
+ case 16:
+ {
+#ifdef PNG_READ_GAMMA_SUPPORTED
+ if (gamma_16 != NULL)
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++, sp += 2)
+ {
+ png_uint_16 v;
+
+ v = (png_uint_16)(((*sp) << 8) + *(sp + 1));
+
+ if (v == png_ptr->trans_color.gray)
+ {
+ /* Background is already in screen gamma */
+ *sp = (png_byte)((png_ptr->background.gray >> 8)
+ & 0xff);
+ *(sp + 1) = (png_byte)(png_ptr->background.gray
+ & 0xff);
+ }
+
+ else
+ {
+ v = gamma_16[*(sp + 1) >> gamma_shift][*sp];
+ *sp = (png_byte)((v >> 8) & 0xff);
+ *(sp + 1) = (png_byte)(v & 0xff);
+ }
+ }
+ }
+ else
+#endif
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++, sp += 2)
+ {
+ png_uint_16 v;
+
+ v = (png_uint_16)(((*sp) << 8) + *(sp + 1));
+
+ if (v == png_ptr->trans_color.gray)
+ {
+ *sp = (png_byte)((png_ptr->background.gray >> 8)
+ & 0xff);
+ *(sp + 1) = (png_byte)(png_ptr->background.gray
+ & 0xff);
+ }
+ }
+ }
+ break;
+ }
+
+ default:
+ break;
+ }
+ break;
+ }
+
+ case PNG_COLOR_TYPE_RGB:
+ {
+ if (row_info->bit_depth == 8)
+ {
+#ifdef PNG_READ_GAMMA_SUPPORTED
+ if (gamma_table != NULL)
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++, sp += 3)
+ {
+ if (*sp == png_ptr->trans_color.red &&
+ *(sp + 1) == png_ptr->trans_color.green &&
+ *(sp + 2) == png_ptr->trans_color.blue)
+ {
+ *sp = (png_byte)png_ptr->background.red;
+ *(sp + 1) = (png_byte)png_ptr->background.green;
+ *(sp + 2) = (png_byte)png_ptr->background.blue;
+ }
+
+ else
+ {
+ *sp = gamma_table[*sp];
+ *(sp + 1) = gamma_table[*(sp + 1)];
+ *(sp + 2) = gamma_table[*(sp + 2)];
+ }
+ }
+ }
+ else
+#endif
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++, sp += 3)
+ {
+ if (*sp == png_ptr->trans_color.red &&
+ *(sp + 1) == png_ptr->trans_color.green &&
+ *(sp + 2) == png_ptr->trans_color.blue)
+ {
+ *sp = (png_byte)png_ptr->background.red;
+ *(sp + 1) = (png_byte)png_ptr->background.green;
+ *(sp + 2) = (png_byte)png_ptr->background.blue;
+ }
+ }
+ }
+ }
+ else /* if (row_info->bit_depth == 16) */
+ {
+#ifdef PNG_READ_GAMMA_SUPPORTED
+ if (gamma_16 != NULL)
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++, sp += 6)
+ {
+ png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp + 1));
+
+ png_uint_16 g = (png_uint_16)(((*(sp + 2)) << 8)
+ + *(sp + 3));
+
+ png_uint_16 b = (png_uint_16)(((*(sp + 4)) << 8)
+ + *(sp + 5));
+
+ if (r == png_ptr->trans_color.red &&
+ g == png_ptr->trans_color.green &&
+ b == png_ptr->trans_color.blue)
+ {
+ /* Background is already in screen gamma */
+ *sp = (png_byte)((png_ptr->background.red >> 8) & 0xff);
+ *(sp + 1) = (png_byte)(png_ptr->background.red & 0xff);
+ *(sp + 2) = (png_byte)((png_ptr->background.green >> 8)
+ & 0xff);
+ *(sp + 3) = (png_byte)(png_ptr->background.green
+ & 0xff);
+ *(sp + 4) = (png_byte)((png_ptr->background.blue >> 8)
+ & 0xff);
+ *(sp + 5) = (png_byte)(png_ptr->background.blue & 0xff);
+ }
+
+ else
+ {
+ png_uint_16 v = gamma_16[*(sp + 1) >> gamma_shift][*sp];
+ *sp = (png_byte)((v >> 8) & 0xff);
+ *(sp + 1) = (png_byte)(v & 0xff);
+
+ v = gamma_16[*(sp + 3) >> gamma_shift][*(sp + 2)];
+ *(sp + 2) = (png_byte)((v >> 8) & 0xff);
+ *(sp + 3) = (png_byte)(v & 0xff);
+
+ v = gamma_16[*(sp + 5) >> gamma_shift][*(sp + 4)];
+ *(sp + 4) = (png_byte)((v >> 8) & 0xff);
+ *(sp + 5) = (png_byte)(v & 0xff);
+ }
+ }
+ }
+
+ else
+#endif
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++, sp += 6)
+ {
+ png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp + 1));
+
+ png_uint_16 g = (png_uint_16)(((*(sp + 2)) << 8)
+ + *(sp + 3));
+
+ png_uint_16 b = (png_uint_16)(((*(sp + 4)) << 8)
+ + *(sp + 5));
+
+ if (r == png_ptr->trans_color.red &&
+ g == png_ptr->trans_color.green &&
+ b == png_ptr->trans_color.blue)
+ {
+ *sp = (png_byte)((png_ptr->background.red >> 8) & 0xff);
+ *(sp + 1) = (png_byte)(png_ptr->background.red & 0xff);
+ *(sp + 2) = (png_byte)((png_ptr->background.green >> 8)
+ & 0xff);
+ *(sp + 3) = (png_byte)(png_ptr->background.green
+ & 0xff);
+ *(sp + 4) = (png_byte)((png_ptr->background.blue >> 8)
+ & 0xff);
+ *(sp + 5) = (png_byte)(png_ptr->background.blue & 0xff);
+ }
+ }
+ }
+ }
+ break;
+ }
+
+ case PNG_COLOR_TYPE_GRAY_ALPHA:
+ {
+ if (row_info->bit_depth == 8)
+ {
+#ifdef PNG_READ_GAMMA_SUPPORTED
+ if (gamma_to_1 != NULL && gamma_from_1 != NULL &&
+ gamma_table != NULL)
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++, sp += 2)
+ {
+ png_uint_16 a = *(sp + 1);
+
+ if (a == 0xff)
+ *sp = gamma_table[*sp];
+
+ else if (a == 0)
+ {
+ /* Background is already in screen gamma */
+ *sp = (png_byte)png_ptr->background.gray;
+ }
+
+ else
+ {
+ png_byte v, w;
+
+ v = gamma_to_1[*sp];
+ png_composite(w, v, a, png_ptr->background_1.gray);
+ if (optimize == 0)
+ w = gamma_from_1[w];
+ *sp = w;
+ }
+ }
+ }
+ else
+#endif
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++, sp += 2)
+ {
+ png_byte a = *(sp + 1);
+
+ if (a == 0)
+ *sp = (png_byte)png_ptr->background.gray;
+
+ else if (a < 0xff)
+ png_composite(*sp, *sp, a, png_ptr->background.gray);
+ }
+ }
+ }
+ else /* if (png_ptr->bit_depth == 16) */
+ {
+#ifdef PNG_READ_GAMMA_SUPPORTED
+ if (gamma_16 != NULL && gamma_16_from_1 != NULL &&
+ gamma_16_to_1 != NULL)
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++, sp += 4)
+ {
+ png_uint_16 a = (png_uint_16)(((*(sp + 2)) << 8)
+ + *(sp + 3));
+
+ if (a == (png_uint_16)0xffff)
+ {
+ png_uint_16 v;
+
+ v = gamma_16[*(sp + 1) >> gamma_shift][*sp];
+ *sp = (png_byte)((v >> 8) & 0xff);
+ *(sp + 1) = (png_byte)(v & 0xff);
+ }
+
+ else if (a == 0)
+ {
+ /* Background is already in screen gamma */
+ *sp = (png_byte)((png_ptr->background.gray >> 8)
+ & 0xff);
+ *(sp + 1) = (png_byte)(png_ptr->background.gray & 0xff);
+ }
+
+ else
+ {
+ png_uint_16 g, v, w;
+
+ g = gamma_16_to_1[*(sp + 1) >> gamma_shift][*sp];
+ png_composite_16(v, g, a, png_ptr->background_1.gray);
+ if (optimize != 0)
+ w = v;
+ else
+ w = gamma_16_from_1[(v & 0xff) >>
+ gamma_shift][v >> 8];
+ *sp = (png_byte)((w >> 8) & 0xff);
+ *(sp + 1) = (png_byte)(w & 0xff);
+ }
+ }
+ }
+ else
+#endif
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++, sp += 4)
+ {
+ png_uint_16 a = (png_uint_16)(((*(sp + 2)) << 8)
+ + *(sp + 3));
+
+ if (a == 0)
+ {
+ *sp = (png_byte)((png_ptr->background.gray >> 8)
+ & 0xff);
+ *(sp + 1) = (png_byte)(png_ptr->background.gray & 0xff);
+ }
+
+ else if (a < 0xffff)
+ {
+ png_uint_16 g, v;
+
+ g = (png_uint_16)(((*sp) << 8) + *(sp + 1));
+ png_composite_16(v, g, a, png_ptr->background.gray);
+ *sp = (png_byte)((v >> 8) & 0xff);
+ *(sp + 1) = (png_byte)(v & 0xff);
+ }
+ }
+ }
+ }
+ break;
+ }
+
+ case PNG_COLOR_TYPE_RGB_ALPHA:
+ {
+ if (row_info->bit_depth == 8)
+ {
+#ifdef PNG_READ_GAMMA_SUPPORTED
+ if (gamma_to_1 != NULL && gamma_from_1 != NULL &&
+ gamma_table != NULL)
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++, sp += 4)
+ {
+ png_byte a = *(sp + 3);
+
+ if (a == 0xff)
+ {
+ *sp = gamma_table[*sp];
+ *(sp + 1) = gamma_table[*(sp + 1)];
+ *(sp + 2) = gamma_table[*(sp + 2)];
+ }
+
+ else if (a == 0)
+ {
+ /* Background is already in screen gamma */
+ *sp = (png_byte)png_ptr->background.red;
+ *(sp + 1) = (png_byte)png_ptr->background.green;
+ *(sp + 2) = (png_byte)png_ptr->background.blue;
+ }
+
+ else
+ {
+ png_byte v, w;
+
+ v = gamma_to_1[*sp];
+ png_composite(w, v, a, png_ptr->background_1.red);
+ if (optimize == 0) w = gamma_from_1[w];
+ *sp = w;
+
+ v = gamma_to_1[*(sp + 1)];
+ png_composite(w, v, a, png_ptr->background_1.green);
+ if (optimize == 0) w = gamma_from_1[w];
+ *(sp + 1) = w;
+
+ v = gamma_to_1[*(sp + 2)];
+ png_composite(w, v, a, png_ptr->background_1.blue);
+ if (optimize == 0) w = gamma_from_1[w];
+ *(sp + 2) = w;
+ }
+ }
+ }
+ else
+#endif
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++, sp += 4)
+ {
+ png_byte a = *(sp + 3);
+
+ if (a == 0)
+ {
+ *sp = (png_byte)png_ptr->background.red;
+ *(sp + 1) = (png_byte)png_ptr->background.green;
+ *(sp + 2) = (png_byte)png_ptr->background.blue;
+ }
+
+ else if (a < 0xff)
+ {
+ png_composite(*sp, *sp, a, png_ptr->background.red);
+
+ png_composite(*(sp + 1), *(sp + 1), a,
+ png_ptr->background.green);
+
+ png_composite(*(sp + 2), *(sp + 2), a,
+ png_ptr->background.blue);
+ }
+ }
+ }
+ }
+ else /* if (row_info->bit_depth == 16) */
+ {
+#ifdef PNG_READ_GAMMA_SUPPORTED
+ if (gamma_16 != NULL && gamma_16_from_1 != NULL &&
+ gamma_16_to_1 != NULL)
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++, sp += 8)
+ {
+ png_uint_16 a = (png_uint_16)(((png_uint_16)(*(sp + 6))
+ << 8) + (png_uint_16)(*(sp + 7)));
+
+ if (a == (png_uint_16)0xffff)
+ {
+ png_uint_16 v;
+
+ v = gamma_16[*(sp + 1) >> gamma_shift][*sp];
+ *sp = (png_byte)((v >> 8) & 0xff);
+ *(sp + 1) = (png_byte)(v & 0xff);
+
+ v = gamma_16[*(sp + 3) >> gamma_shift][*(sp + 2)];
+ *(sp + 2) = (png_byte)((v >> 8) & 0xff);
+ *(sp + 3) = (png_byte)(v & 0xff);
+
+ v = gamma_16[*(sp + 5) >> gamma_shift][*(sp + 4)];
+ *(sp + 4) = (png_byte)((v >> 8) & 0xff);
+ *(sp + 5) = (png_byte)(v & 0xff);
+ }
+
+ else if (a == 0)
+ {
+ /* Background is already in screen gamma */
+ *sp = (png_byte)((png_ptr->background.red >> 8) & 0xff);
+ *(sp + 1) = (png_byte)(png_ptr->background.red & 0xff);
+ *(sp + 2) = (png_byte)((png_ptr->background.green >> 8)
+ & 0xff);
+ *(sp + 3) = (png_byte)(png_ptr->background.green
+ & 0xff);
+ *(sp + 4) = (png_byte)((png_ptr->background.blue >> 8)
+ & 0xff);
+ *(sp + 5) = (png_byte)(png_ptr->background.blue & 0xff);
+ }
+
+ else
+ {
+ png_uint_16 v, w;
+
+ v = gamma_16_to_1[*(sp + 1) >> gamma_shift][*sp];
+ png_composite_16(w, v, a, png_ptr->background_1.red);
+ if (optimize == 0)
+ w = gamma_16_from_1[((w & 0xff) >> gamma_shift)][w >>
+ 8];
+ *sp = (png_byte)((w >> 8) & 0xff);
+ *(sp + 1) = (png_byte)(w & 0xff);
+
+ v = gamma_16_to_1[*(sp + 3) >> gamma_shift][*(sp + 2)];
+ png_composite_16(w, v, a, png_ptr->background_1.green);
+ if (optimize == 0)
+ w = gamma_16_from_1[((w & 0xff) >> gamma_shift)][w >>
+ 8];
+
+ *(sp + 2) = (png_byte)((w >> 8) & 0xff);
+ *(sp + 3) = (png_byte)(w & 0xff);
+
+ v = gamma_16_to_1[*(sp + 5) >> gamma_shift][*(sp + 4)];
+ png_composite_16(w, v, a, png_ptr->background_1.blue);
+ if (optimize == 0)
+ w = gamma_16_from_1[((w & 0xff) >> gamma_shift)][w >>
+ 8];
+
+ *(sp + 4) = (png_byte)((w >> 8) & 0xff);
+ *(sp + 5) = (png_byte)(w & 0xff);
+ }
+ }
+ }
+
+ else
+#endif
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++, sp += 8)
+ {
+ png_uint_16 a = (png_uint_16)(((png_uint_16)(*(sp + 6))
+ << 8) + (png_uint_16)(*(sp + 7)));
+
+ if (a == 0)
+ {
+ *sp = (png_byte)((png_ptr->background.red >> 8) & 0xff);
+ *(sp + 1) = (png_byte)(png_ptr->background.red & 0xff);
+ *(sp + 2) = (png_byte)((png_ptr->background.green >> 8)
+ & 0xff);
+ *(sp + 3) = (png_byte)(png_ptr->background.green
+ & 0xff);
+ *(sp + 4) = (png_byte)((png_ptr->background.blue >> 8)
+ & 0xff);
+ *(sp + 5) = (png_byte)(png_ptr->background.blue & 0xff);
+ }
+
+ else if (a < 0xffff)
+ {
+ png_uint_16 v;
+
+ png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp + 1));
+ png_uint_16 g = (png_uint_16)(((*(sp + 2)) << 8)
+ + *(sp + 3));
+ png_uint_16 b = (png_uint_16)(((*(sp + 4)) << 8)
+ + *(sp + 5));
+
+ png_composite_16(v, r, a, png_ptr->background.red);
+ *sp = (png_byte)((v >> 8) & 0xff);
+ *(sp + 1) = (png_byte)(v & 0xff);
+
+ png_composite_16(v, g, a, png_ptr->background.green);
+ *(sp + 2) = (png_byte)((v >> 8) & 0xff);
+ *(sp + 3) = (png_byte)(v & 0xff);
+
+ png_composite_16(v, b, a, png_ptr->background.blue);
+ *(sp + 4) = (png_byte)((v >> 8) & 0xff);
+ *(sp + 5) = (png_byte)(v & 0xff);
+ }
+ }
+ }
+ }
+ break;
+ }
+
+ default:
+ break;
+ }
+ }
+}
+#endif /* READ_BACKGROUND || READ_ALPHA_MODE */
+
+#ifdef PNG_READ_GAMMA_SUPPORTED
+/* Gamma correct the image, avoiding the alpha channel. Make sure
+ * you do this after you deal with the transparency issue on grayscale
+ * or RGB images. If your bit depth is 8, use gamma_table, if it
+ * is 16, use gamma_16_table and gamma_shift. Build these with
+ * build_gamma_table().
+ */
+static void
+png_do_gamma(png_row_infop row_info, png_bytep row, png_structrp png_ptr)
+{
+ png_const_bytep gamma_table = png_ptr->gamma_table;
+ png_const_uint_16pp gamma_16_table = png_ptr->gamma_16_table;
+ int gamma_shift = png_ptr->gamma_shift;
+
+ png_bytep sp;
+ png_uint_32 i;
+ png_uint_32 row_width=row_info->width;
+
+ png_debug(1, "in png_do_gamma");
+
+ if (((row_info->bit_depth <= 8 && gamma_table != NULL) ||
+ (row_info->bit_depth == 16 && gamma_16_table != NULL)))
+ {
+ switch (row_info->color_type)
+ {
+ case PNG_COLOR_TYPE_RGB:
+ {
+ if (row_info->bit_depth == 8)
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++)
+ {
+ *sp = gamma_table[*sp];
+ sp++;
+ *sp = gamma_table[*sp];
+ sp++;
+ *sp = gamma_table[*sp];
+ sp++;
+ }
+ }
+
+ else /* if (row_info->bit_depth == 16) */
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++)
+ {
+ png_uint_16 v;
+
+ v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
+ *sp = (png_byte)((v >> 8) & 0xff);
+ *(sp + 1) = (png_byte)(v & 0xff);
+ sp += 2;
+
+ v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
+ *sp = (png_byte)((v >> 8) & 0xff);
+ *(sp + 1) = (png_byte)(v & 0xff);
+ sp += 2;
+
+ v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
+ *sp = (png_byte)((v >> 8) & 0xff);
+ *(sp + 1) = (png_byte)(v & 0xff);
+ sp += 2;
+ }
+ }
+ break;
+ }
+
+ case PNG_COLOR_TYPE_RGB_ALPHA:
+ {
+ if (row_info->bit_depth == 8)
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++)
+ {
+ *sp = gamma_table[*sp];
+ sp++;
+
+ *sp = gamma_table[*sp];
+ sp++;
+
+ *sp = gamma_table[*sp];
+ sp++;
+
+ sp++;
+ }
+ }
+
+ else /* if (row_info->bit_depth == 16) */
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++)
+ {
+ png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
+ *sp = (png_byte)((v >> 8) & 0xff);
+ *(sp + 1) = (png_byte)(v & 0xff);
+ sp += 2;
+
+ v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
+ *sp = (png_byte)((v >> 8) & 0xff);
+ *(sp + 1) = (png_byte)(v & 0xff);
+ sp += 2;
+
+ v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
+ *sp = (png_byte)((v >> 8) & 0xff);
+ *(sp + 1) = (png_byte)(v & 0xff);
+ sp += 4;
+ }
+ }
+ break;
+ }
+
+ case PNG_COLOR_TYPE_GRAY_ALPHA:
+ {
+ if (row_info->bit_depth == 8)
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++)
+ {
+ *sp = gamma_table[*sp];
+ sp += 2;
+ }
+ }
+
+ else /* if (row_info->bit_depth == 16) */
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++)
+ {
+ png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
+ *sp = (png_byte)((v >> 8) & 0xff);
+ *(sp + 1) = (png_byte)(v & 0xff);
+ sp += 4;
+ }
+ }
+ break;
+ }
+
+ case PNG_COLOR_TYPE_GRAY:
+ {
+ if (row_info->bit_depth == 2)
+ {
+ sp = row;
+ for (i = 0; i < row_width; i += 4)
+ {
+ int a = *sp & 0xc0;
+ int b = *sp & 0x30;
+ int c = *sp & 0x0c;
+ int d = *sp & 0x03;
+
+ *sp = (png_byte)(
+ ((((int)gamma_table[a|(a>>2)|(a>>4)|(a>>6)]) ) & 0xc0)|
+ ((((int)gamma_table[(b<<2)|b|(b>>2)|(b>>4)])>>2) & 0x30)|
+ ((((int)gamma_table[(c<<4)|(c<<2)|c|(c>>2)])>>4) & 0x0c)|
+ ((((int)gamma_table[(d<<6)|(d<<4)|(d<<2)|d])>>6) ));
+ sp++;
+ }
+ }
+
+ if (row_info->bit_depth == 4)
+ {
+ sp = row;
+ for (i = 0; i < row_width; i += 2)
+ {
+ int msb = *sp & 0xf0;
+ int lsb = *sp & 0x0f;
+
+ *sp = (png_byte)((((int)gamma_table[msb | (msb >> 4)]) & 0xf0)
+ | (((int)gamma_table[(lsb << 4) | lsb]) >> 4));
+ sp++;
+ }
+ }
+
+ else if (row_info->bit_depth == 8)
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++)
+ {
+ *sp = gamma_table[*sp];
+ sp++;
+ }
+ }
+
+ else if (row_info->bit_depth == 16)
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++)
+ {
+ png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
+ *sp = (png_byte)((v >> 8) & 0xff);
+ *(sp + 1) = (png_byte)(v & 0xff);
+ sp += 2;
+ }
+ }
+ break;
+ }
+
+ default:
+ break;
+ }
+ }
+}
+#endif
+
+#ifdef PNG_READ_ALPHA_MODE_SUPPORTED
+/* Encode the alpha channel to the output gamma (the input channel is always
+ * linear.) Called only with color types that have an alpha channel. Needs the
+ * from_1 tables.
+ */
+static void
+png_do_encode_alpha(png_row_infop row_info, png_bytep row, png_structrp png_ptr)
+{
+ png_uint_32 row_width = row_info->width;
+
+ png_debug(1, "in png_do_encode_alpha");
+
+ if ((row_info->color_type & PNG_COLOR_MASK_ALPHA) != 0)
+ {
+ if (row_info->bit_depth == 8)
+ {
+ PNG_CONST png_bytep table = png_ptr->gamma_from_1;
+
+ if (table != NULL)
+ {
+ PNG_CONST int step =
+ (row_info->color_type & PNG_COLOR_MASK_COLOR) ? 4 : 2;
+
+ /* The alpha channel is the last component: */
+ row += step - 1;
+
+ for (; row_width > 0; --row_width, row += step)
+ *row = table[*row];
+
+ return;
+ }
+ }
+
+ else if (row_info->bit_depth == 16)
+ {
+ PNG_CONST png_uint_16pp table = png_ptr->gamma_16_from_1;
+ PNG_CONST int gamma_shift = png_ptr->gamma_shift;
+
+ if (table != NULL)
+ {
+ PNG_CONST int step =
+ (row_info->color_type & PNG_COLOR_MASK_COLOR) ? 8 : 4;
+
+ /* The alpha channel is the last component: */
+ row += step - 2;
+
+ for (; row_width > 0; --row_width, row += step)
+ {
+ png_uint_16 v;
+
+ v = table[*(row + 1) >> gamma_shift][*row];
+ *row = (png_byte)((v >> 8) & 0xff);
+ *(row + 1) = (png_byte)(v & 0xff);
+ }
+
+ return;
+ }
+ }
+ }
+
+ /* Only get to here if called with a weird row_info; no harm has been done,
+ * so just issue a warning.
+ */
+ png_warning(png_ptr, "png_do_encode_alpha: unexpected call");
+}
+#endif
+
+#ifdef PNG_READ_EXPAND_SUPPORTED
+/* Expands a palette row to an RGB or RGBA row depending
+ * upon whether you supply trans and num_trans.
+ */
+static void
+png_do_expand_palette(png_row_infop row_info, png_bytep row,
+ png_const_colorp palette, png_const_bytep trans_alpha, int num_trans)
+{
+ int shift, value;
+ png_bytep sp, dp;
+ png_uint_32 i;
+ png_uint_32 row_width=row_info->width;
+
+ png_debug(1, "in png_do_expand_palette");
+
+ if (row_info->color_type == PNG_COLOR_TYPE_PALETTE)
+ {
+ if (row_info->bit_depth < 8)
+ {
+ switch (row_info->bit_depth)
+ {
+ case 1:
+ {
+ sp = row + (png_size_t)((row_width - 1) >> 3);
+ dp = row + (png_size_t)row_width - 1;
+ shift = 7 - (int)((row_width + 7) & 0x07);
+ for (i = 0; i < row_width; i++)
+ {
+ if ((*sp >> shift) & 0x01)
+ *dp = 1;
+
+ else
+ *dp = 0;
+
+ if (shift == 7)
+ {
+ shift = 0;
+ sp--;
+ }
+
+ else
+ shift++;
+
+ dp--;
+ }
+ break;
+ }
+
+ case 2:
+ {
+ sp = row + (png_size_t)((row_width - 1) >> 2);
+ dp = row + (png_size_t)row_width - 1;
+ shift = (int)((3 - ((row_width + 3) & 0x03)) << 1);
+ for (i = 0; i < row_width; i++)
+ {
+ value = (*sp >> shift) & 0x03;
+ *dp = (png_byte)value;
+ if (shift == 6)
+ {
+ shift = 0;
+ sp--;
+ }
+
+ else
+ shift += 2;
+
+ dp--;
+ }
+ break;
+ }
+
+ case 4:
+ {
+ sp = row + (png_size_t)((row_width - 1) >> 1);
+ dp = row + (png_size_t)row_width - 1;
+ shift = (int)((row_width & 0x01) << 2);
+ for (i = 0; i < row_width; i++)
+ {
+ value = (*sp >> shift) & 0x0f;
+ *dp = (png_byte)value;
+ if (shift == 4)
+ {
+ shift = 0;
+ sp--;
+ }
+
+ else
+ shift += 4;
+
+ dp--;
+ }
+ break;
+ }
+
+ default:
+ break;
+ }
+ row_info->bit_depth = 8;
+ row_info->pixel_depth = 8;
+ row_info->rowbytes = row_width;
+ }
+
+ if (row_info->bit_depth == 8)
+ {
+ {
+ if (num_trans > 0)
+ {
+ sp = row + (png_size_t)row_width - 1;
+ dp = row + (png_size_t)(row_width << 2) - 1;
+
+ for (i = 0; i < row_width; i++)
+ {
+ if ((int)(*sp) >= num_trans)
+ *dp-- = 0xff;
+
+ else
+ *dp-- = trans_alpha[*sp];
+
+ *dp-- = palette[*sp].blue;
+ *dp-- = palette[*sp].green;
+ *dp-- = palette[*sp].red;
+ sp--;
+ }
+ row_info->bit_depth = 8;
+ row_info->pixel_depth = 32;
+ row_info->rowbytes = row_width * 4;
+ row_info->color_type = 6;
+ row_info->channels = 4;
+ }
+
+ else
+ {
+ sp = row + (png_size_t)row_width - 1;
+ dp = row + (png_size_t)(row_width * 3) - 1;
+
+ for (i = 0; i < row_width; i++)
+ {
+ *dp-- = palette[*sp].blue;
+ *dp-- = palette[*sp].green;
+ *dp-- = palette[*sp].red;
+ sp--;
+ }
+
+ row_info->bit_depth = 8;
+ row_info->pixel_depth = 24;
+ row_info->rowbytes = row_width * 3;
+ row_info->color_type = 2;
+ row_info->channels = 3;
+ }
+ }
+ }
+ }
+}
+
+/* If the bit depth < 8, it is expanded to 8. Also, if the already
+ * expanded transparency value is supplied, an alpha channel is built.
+ */
+static void
+png_do_expand(png_row_infop row_info, png_bytep row,
+ png_const_color_16p trans_color)
+{
+ int shift, value;
+ png_bytep sp, dp;
+ png_uint_32 i;
+ png_uint_32 row_width=row_info->width;
+
+ png_debug(1, "in png_do_expand");
+
+ {
+ if (row_info->color_type == PNG_COLOR_TYPE_GRAY)
+ {
+ unsigned int gray = trans_color != NULL ? trans_color->gray : 0;
+
+ if (row_info->bit_depth < 8)
+ {
+ switch (row_info->bit_depth)
+ {
+ case 1:
+ {
+ gray = (gray & 0x01) * 0xff;
+ sp = row + (png_size_t)((row_width - 1) >> 3);
+ dp = row + (png_size_t)row_width - 1;
+ shift = 7 - (int)((row_width + 7) & 0x07);
+ for (i = 0; i < row_width; i++)
+ {
+ if ((*sp >> shift) & 0x01)
+ *dp = 0xff;
+
+ else
+ *dp = 0;
+
+ if (shift == 7)
+ {
+ shift = 0;
+ sp--;
+ }
+
+ else
+ shift++;
+
+ dp--;
+ }
+ break;
+ }
+
+ case 2:
+ {
+ gray = (gray & 0x03) * 0x55;
+ sp = row + (png_size_t)((row_width - 1) >> 2);
+ dp = row + (png_size_t)row_width - 1;
+ shift = (int)((3 - ((row_width + 3) & 0x03)) << 1);
+ for (i = 0; i < row_width; i++)
+ {
+ value = (*sp >> shift) & 0x03;
+ *dp = (png_byte)(value | (value << 2) | (value << 4) |
+ (value << 6));
+ if (shift == 6)
+ {
+ shift = 0;
+ sp--;
+ }
+
+ else
+ shift += 2;
+
+ dp--;
+ }
+ break;
+ }
+
+ case 4:
+ {
+ gray = (gray & 0x0f) * 0x11;
+ sp = row + (png_size_t)((row_width - 1) >> 1);
+ dp = row + (png_size_t)row_width - 1;
+ shift = (int)((1 - ((row_width + 1) & 0x01)) << 2);
+ for (i = 0; i < row_width; i++)
+ {
+ value = (*sp >> shift) & 0x0f;
+ *dp = (png_byte)(value | (value << 4));
+ if (shift == 4)
+ {
+ shift = 0;
+ sp--;
+ }
+
+ else
+ shift = 4;
+
+ dp--;
+ }
+ break;
+ }
+
+ default:
+ break;
+ }
+
+ row_info->bit_depth = 8;
+ row_info->pixel_depth = 8;
+ row_info->rowbytes = row_width;
+ }
+
+ if (trans_color != NULL)
+ {
+ if (row_info->bit_depth == 8)
+ {
+ gray = gray & 0xff;
+ sp = row + (png_size_t)row_width - 1;
+ dp = row + (png_size_t)(row_width << 1) - 1;
+
+ for (i = 0; i < row_width; i++)
+ {
+ if ((*sp & 0xffU) == gray)
+ *dp-- = 0;
+
+ else
+ *dp-- = 0xff;
+
+ *dp-- = *sp--;
+ }
+ }
+
+ else if (row_info->bit_depth == 16)
+ {
+ unsigned int gray_high = (gray >> 8) & 0xff;
+ unsigned int gray_low = gray & 0xff;
+ sp = row + row_info->rowbytes - 1;
+ dp = row + (row_info->rowbytes << 1) - 1;
+ for (i = 0; i < row_width; i++)
+ {
+ if ((*(sp - 1) & 0xffU) == gray_high &&
+ (*(sp) & 0xffU) == gray_low)
+ {
+ *dp-- = 0;
+ *dp-- = 0;
+ }
+
+ else
+ {
+ *dp-- = 0xff;
+ *dp-- = 0xff;
+ }
+
+ *dp-- = *sp--;
+ *dp-- = *sp--;
+ }
+ }
+
+ row_info->color_type = PNG_COLOR_TYPE_GRAY_ALPHA;
+ row_info->channels = 2;
+ row_info->pixel_depth = (png_byte)(row_info->bit_depth << 1);
+ row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth,
+ row_width);
+ }
+ }
+ else if (row_info->color_type == PNG_COLOR_TYPE_RGB &&
+ trans_color != NULL)
+ {
+ if (row_info->bit_depth == 8)
+ {
+ png_byte red = (png_byte)(trans_color->red & 0xff);
+ png_byte green = (png_byte)(trans_color->green & 0xff);
+ png_byte blue = (png_byte)(trans_color->blue & 0xff);
+ sp = row + (png_size_t)row_info->rowbytes - 1;
+ dp = row + (png_size_t)(row_width << 2) - 1;
+ for (i = 0; i < row_width; i++)
+ {
+ if (*(sp - 2) == red && *(sp - 1) == green && *(sp) == blue)
+ *dp-- = 0;
+
+ else
+ *dp-- = 0xff;
+
+ *dp-- = *sp--;
+ *dp-- = *sp--;
+ *dp-- = *sp--;
+ }
+ }
+ else if (row_info->bit_depth == 16)
+ {
+ png_byte red_high = (png_byte)((trans_color->red >> 8) & 0xff);
+ png_byte green_high = (png_byte)((trans_color->green >> 8) & 0xff);
+ png_byte blue_high = (png_byte)((trans_color->blue >> 8) & 0xff);
+ png_byte red_low = (png_byte)(trans_color->red & 0xff);
+ png_byte green_low = (png_byte)(trans_color->green & 0xff);
+ png_byte blue_low = (png_byte)(trans_color->blue & 0xff);
+ sp = row + row_info->rowbytes - 1;
+ dp = row + (png_size_t)(row_width << 3) - 1;
+ for (i = 0; i < row_width; i++)
+ {
+ if (*(sp - 5) == red_high &&
+ *(sp - 4) == red_low &&
+ *(sp - 3) == green_high &&
+ *(sp - 2) == green_low &&
+ *(sp - 1) == blue_high &&
+ *(sp ) == blue_low)
+ {
+ *dp-- = 0;
+ *dp-- = 0;
+ }
+
+ else
+ {
+ *dp-- = 0xff;
+ *dp-- = 0xff;
+ }
+
+ *dp-- = *sp--;
+ *dp-- = *sp--;
+ *dp-- = *sp--;
+ *dp-- = *sp--;
+ *dp-- = *sp--;
+ *dp-- = *sp--;
+ }
+ }
+ row_info->color_type = PNG_COLOR_TYPE_RGB_ALPHA;
+ row_info->channels = 4;
+ row_info->pixel_depth = (png_byte)(row_info->bit_depth << 2);
+ row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);
+ }
+ }
+}
+#endif
+
+#ifdef PNG_READ_EXPAND_16_SUPPORTED
+/* If the bit depth is 8 and the color type is not a palette type expand the
+ * whole row to 16 bits. Has no effect otherwise.
+ */
+static void
+png_do_expand_16(png_row_infop row_info, png_bytep row)
+{
+ if (row_info->bit_depth == 8 &&
+ row_info->color_type != PNG_COLOR_TYPE_PALETTE)
+ {
+ /* The row have a sequence of bytes containing [0..255] and we need
+ * to turn it into another row containing [0..65535], to do this we
+ * calculate:
+ *
+ * (input / 255) * 65535
+ *
+ * Which happens to be exactly input * 257 and this can be achieved
+ * simply by byte replication in place (copying backwards).
+ */
+ png_byte *sp = row + row_info->rowbytes; /* source, last byte + 1 */
+ png_byte *dp = sp + row_info->rowbytes; /* destination, end + 1 */
+ while (dp > sp)
+ dp[-2] = dp[-1] = *--sp, dp -= 2;
+
+ row_info->rowbytes *= 2;
+ row_info->bit_depth = 16;
+ row_info->pixel_depth = (png_byte)(row_info->channels * 16);
+ }
+}
+#endif
+
+#ifdef PNG_READ_QUANTIZE_SUPPORTED
+static void
+png_do_quantize(png_row_infop row_info, png_bytep row,
+ png_const_bytep palette_lookup, png_const_bytep quantize_lookup)
+{
+ png_bytep sp, dp;
+ png_uint_32 i;
+ png_uint_32 row_width=row_info->width;
+
+ png_debug(1, "in png_do_quantize");
+
+ if (row_info->bit_depth == 8)
+ {
+ if (row_info->color_type == PNG_COLOR_TYPE_RGB && palette_lookup)
+ {
+ int r, g, b, p;
+ sp = row;
+ dp = row;
+ for (i = 0; i < row_width; i++)
+ {
+ r = *sp++;
+ g = *sp++;
+ b = *sp++;
+
+ /* This looks real messy, but the compiler will reduce
+ * it down to a reasonable formula. For example, with
+ * 5 bits per color, we get:
+ * p = (((r >> 3) & 0x1f) << 10) |
+ * (((g >> 3) & 0x1f) << 5) |
+ * ((b >> 3) & 0x1f);
+ */
+ p = (((r >> (8 - PNG_QUANTIZE_RED_BITS)) &
+ ((1 << PNG_QUANTIZE_RED_BITS) - 1)) <<
+ (PNG_QUANTIZE_GREEN_BITS + PNG_QUANTIZE_BLUE_BITS)) |
+ (((g >> (8 - PNG_QUANTIZE_GREEN_BITS)) &
+ ((1 << PNG_QUANTIZE_GREEN_BITS) - 1)) <<
+ (PNG_QUANTIZE_BLUE_BITS)) |
+ ((b >> (8 - PNG_QUANTIZE_BLUE_BITS)) &
+ ((1 << PNG_QUANTIZE_BLUE_BITS) - 1));
+
+ *dp++ = palette_lookup[p];
+ }
+
+ row_info->color_type = PNG_COLOR_TYPE_PALETTE;
+ row_info->channels = 1;
+ row_info->pixel_depth = row_info->bit_depth;
+ row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);
+ }
+
+ else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA &&
+ palette_lookup != NULL)
+ {
+ int r, g, b, p;
+ sp = row;
+ dp = row;
+ for (i = 0; i < row_width; i++)
+ {
+ r = *sp++;
+ g = *sp++;
+ b = *sp++;
+ sp++;
+
+ p = (((r >> (8 - PNG_QUANTIZE_RED_BITS)) &
+ ((1 << PNG_QUANTIZE_RED_BITS) - 1)) <<
+ (PNG_QUANTIZE_GREEN_BITS + PNG_QUANTIZE_BLUE_BITS)) |
+ (((g >> (8 - PNG_QUANTIZE_GREEN_BITS)) &
+ ((1 << PNG_QUANTIZE_GREEN_BITS) - 1)) <<
+ (PNG_QUANTIZE_BLUE_BITS)) |
+ ((b >> (8 - PNG_QUANTIZE_BLUE_BITS)) &
+ ((1 << PNG_QUANTIZE_BLUE_BITS) - 1));
+
+ *dp++ = palette_lookup[p];
+ }
+
+ row_info->color_type = PNG_COLOR_TYPE_PALETTE;
+ row_info->channels = 1;
+ row_info->pixel_depth = row_info->bit_depth;
+ row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);
+ }
+
+ else if (row_info->color_type == PNG_COLOR_TYPE_PALETTE &&
+ quantize_lookup)
+ {
+ sp = row;
+
+ for (i = 0; i < row_width; i++, sp++)
+ {
+ *sp = quantize_lookup[*sp];
+ }
+ }
+ }
+}
+#endif /* READ_QUANTIZE */
+
+/* Transform the row. The order of transformations is significant,
+ * and is very touchy. If you add a transformation, take care to
+ * decide how it fits in with the other transformations here.
+ */
+void /* PRIVATE */
+png_do_read_transformations(png_structrp png_ptr, png_row_infop row_info)
+{
+ png_debug(1, "in png_do_read_transformations");
+
+ if (png_ptr->row_buf == NULL)
+ {
+ /* Prior to 1.5.4 this output row/pass where the NULL pointer is, but this
+ * error is incredibly rare and incredibly easy to debug without this
+ * information.
+ */
+ png_error(png_ptr, "NULL row buffer");
+ }
+
+ /* The following is debugging; prior to 1.5.4 the code was never compiled in;
+ * in 1.5.4 PNG_FLAG_DETECT_UNINITIALIZED was added and the macro
+ * PNG_WARN_UNINITIALIZED_ROW removed. In 1.6 the new flag is set only for
+ * all transformations, however in practice the ROW_INIT always gets done on
+ * demand, if necessary.
+ */
+ if ((png_ptr->flags & PNG_FLAG_DETECT_UNINITIALIZED) != 0 &&
+ (png_ptr->flags & PNG_FLAG_ROW_INIT) == 0)
+ {
+ /* Application has failed to call either png_read_start_image() or
+ * png_read_update_info() after setting transforms that expand pixels.
+ * This check added to libpng-1.2.19 (but not enabled until 1.5.4).
+ */
+ png_error(png_ptr, "Uninitialized row");
+ }
+
+#ifdef PNG_READ_EXPAND_SUPPORTED
+ if ((png_ptr->transformations & PNG_EXPAND) != 0)
+ {
+ if (row_info->color_type == PNG_COLOR_TYPE_PALETTE)
+ {
+ png_do_expand_palette(row_info, png_ptr->row_buf + 1,
+ png_ptr->palette, png_ptr->trans_alpha, png_ptr->num_trans);
+ }
+
+ else
+ {
+ if (png_ptr->num_trans != 0 &&
+ (png_ptr->transformations & PNG_EXPAND_tRNS) != 0)
+ png_do_expand(row_info, png_ptr->row_buf + 1,
+ &(png_ptr->trans_color));
+
+ else
+ png_do_expand(row_info, png_ptr->row_buf + 1,
+ NULL);
+ }
+ }
+#endif
+
+#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
+ if ((png_ptr->transformations & PNG_STRIP_ALPHA) != 0 &&
+ (png_ptr->transformations & PNG_COMPOSE) == 0 &&
+ (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA ||
+ row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA))
+ png_do_strip_channel(row_info, png_ptr->row_buf + 1,
+ 0 /* at_start == false, because SWAP_ALPHA happens later */);
+#endif
+
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+ if ((png_ptr->transformations & PNG_RGB_TO_GRAY) != 0)
+ {
+ int rgb_error =
+ png_do_rgb_to_gray(png_ptr, row_info,
+ png_ptr->row_buf + 1);
+
+ if (rgb_error != 0)
+ {
+ png_ptr->rgb_to_gray_status=1;
+ if ((png_ptr->transformations & PNG_RGB_TO_GRAY) ==
+ PNG_RGB_TO_GRAY_WARN)
+ png_warning(png_ptr, "png_do_rgb_to_gray found nongray pixel");
+
+ if ((png_ptr->transformations & PNG_RGB_TO_GRAY) ==
+ PNG_RGB_TO_GRAY_ERR)
+ png_error(png_ptr, "png_do_rgb_to_gray found nongray pixel");
+ }
+ }
+#endif
+
+/* From Andreas Dilger e-mail to png-implement, 26 March 1998:
+ *
+ * In most cases, the "simple transparency" should be done prior to doing
+ * gray-to-RGB, or you will have to test 3x as many bytes to check if a
+ * pixel is transparent. You would also need to make sure that the
+ * transparency information is upgraded to RGB.
+ *
+ * To summarize, the current flow is:
+ * - Gray + simple transparency -> compare 1 or 2 gray bytes and composite
+ * with background "in place" if transparent,
+ * convert to RGB if necessary
+ * - Gray + alpha -> composite with gray background and remove alpha bytes,
+ * convert to RGB if necessary
+ *
+ * To support RGB backgrounds for gray images we need:
+ * - Gray + simple transparency -> convert to RGB + simple transparency,
+ * compare 3 or 6 bytes and composite with
+ * background "in place" if transparent
+ * (3x compare/pixel compared to doing
+ * composite with gray bkgrnd)
+ * - Gray + alpha -> convert to RGB + alpha, composite with background and
+ * remove alpha bytes (3x float
+ * operations/pixel compared with composite
+ * on gray background)
+ *
+ * Greg's change will do this. The reason it wasn't done before is for
+ * performance, as this increases the per-pixel operations. If we would check
+ * in advance if the background was gray or RGB, and position the gray-to-RGB
+ * transform appropriately, then it would save a lot of work/time.
+ */
+
+#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
+ /* If gray -> RGB, do so now only if background is non-gray; else do later
+ * for performance reasons
+ */
+ if ((png_ptr->transformations & PNG_GRAY_TO_RGB) != 0 &&
+ (png_ptr->mode & PNG_BACKGROUND_IS_GRAY) == 0)
+ png_do_gray_to_rgb(row_info, png_ptr->row_buf + 1);
+#endif
+
+#if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\
+ defined(PNG_READ_ALPHA_MODE_SUPPORTED)
+ if ((png_ptr->transformations & PNG_COMPOSE) != 0)
+ png_do_compose(row_info, png_ptr->row_buf + 1, png_ptr);
+#endif
+
+#ifdef PNG_READ_GAMMA_SUPPORTED
+ if ((png_ptr->transformations & PNG_GAMMA) != 0 &&
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+ /* Because RGB_TO_GRAY does the gamma transform. */
+ (png_ptr->transformations & PNG_RGB_TO_GRAY) == 0 &&
+#endif
+#if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\
+ defined(PNG_READ_ALPHA_MODE_SUPPORTED)
+ /* Because PNG_COMPOSE does the gamma transform if there is something to
+ * do (if there is an alpha channel or transparency.)
+ */
+ !((png_ptr->transformations & PNG_COMPOSE) != 0 &&
+ ((png_ptr->num_trans != 0) ||
+ (png_ptr->color_type & PNG_COLOR_MASK_ALPHA) != 0)) &&
+#endif
+ /* Because png_init_read_transformations transforms the palette, unless
+ * RGB_TO_GRAY will do the transform.
+ */
+ (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE))
+ png_do_gamma(row_info, png_ptr->row_buf + 1, png_ptr);
+#endif
+
+#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
+ if ((png_ptr->transformations & PNG_STRIP_ALPHA) != 0 &&
+ (png_ptr->transformations & PNG_COMPOSE) != 0 &&
+ (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA ||
+ row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA))
+ png_do_strip_channel(row_info, png_ptr->row_buf + 1,
+ 0 /* at_start == false, because SWAP_ALPHA happens later */);
+#endif
+
+#ifdef PNG_READ_ALPHA_MODE_SUPPORTED
+ if ((png_ptr->transformations & PNG_ENCODE_ALPHA) != 0 &&
+ (row_info->color_type & PNG_COLOR_MASK_ALPHA) != 0)
+ png_do_encode_alpha(row_info, png_ptr->row_buf + 1, png_ptr);
+#endif
+
+#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
+ if ((png_ptr->transformations & PNG_SCALE_16_TO_8) != 0)
+ png_do_scale_16_to_8(row_info, png_ptr->row_buf + 1);
+#endif
+
+#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
+ /* There is no harm in doing both of these because only one has any effect,
+ * by putting the 'scale' option first if the app asks for scale (either by
+ * calling the API or in a TRANSFORM flag) this is what happens.
+ */
+ if ((png_ptr->transformations & PNG_16_TO_8) != 0)
+ png_do_chop(row_info, png_ptr->row_buf + 1);
+#endif
+
+#ifdef PNG_READ_QUANTIZE_SUPPORTED
+ if ((png_ptr->transformations & PNG_QUANTIZE) != 0)
+ {
+ png_do_quantize(row_info, png_ptr->row_buf + 1,
+ png_ptr->palette_lookup, png_ptr->quantize_index);
+
+ if (row_info->rowbytes == 0)
+ png_error(png_ptr, "png_do_quantize returned rowbytes=0");
+ }
+#endif /* READ_QUANTIZE */
+
+#ifdef PNG_READ_EXPAND_16_SUPPORTED
+ /* Do the expansion now, after all the arithmetic has been done. Notice
+ * that previous transformations can handle the PNG_EXPAND_16 flag if this
+ * is efficient (particularly true in the case of gamma correction, where
+ * better accuracy results faster!)
+ */
+ if ((png_ptr->transformations & PNG_EXPAND_16) != 0)
+ png_do_expand_16(row_info, png_ptr->row_buf + 1);
+#endif
+
+#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
+ /* NOTE: moved here in 1.5.4 (from much later in this list.) */
+ if ((png_ptr->transformations & PNG_GRAY_TO_RGB) != 0 &&
+ (png_ptr->mode & PNG_BACKGROUND_IS_GRAY) != 0)
+ png_do_gray_to_rgb(row_info, png_ptr->row_buf + 1);
+#endif
+
+#ifdef PNG_READ_INVERT_SUPPORTED
+ if ((png_ptr->transformations & PNG_INVERT_MONO) != 0)
+ png_do_invert(row_info, png_ptr->row_buf + 1);
+#endif
+
+#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED
+ if ((png_ptr->transformations & PNG_INVERT_ALPHA) != 0)
+ png_do_read_invert_alpha(row_info, png_ptr->row_buf + 1);
+#endif
+
+#ifdef PNG_READ_SHIFT_SUPPORTED
+ if ((png_ptr->transformations & PNG_SHIFT) != 0)
+ png_do_unshift(row_info, png_ptr->row_buf + 1,
+ &(png_ptr->shift));
+#endif
+
+#ifdef PNG_READ_PACK_SUPPORTED
+ if ((png_ptr->transformations & PNG_PACK) != 0)
+ png_do_unpack(row_info, png_ptr->row_buf + 1);
+#endif
+
+#ifdef PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED
+ /* Added at libpng-1.5.10 */
+ if (row_info->color_type == PNG_COLOR_TYPE_PALETTE &&
+ png_ptr->num_palette_max >= 0)
+ png_do_check_palette_indexes(png_ptr, row_info);
+#endif
+
+#ifdef PNG_READ_BGR_SUPPORTED
+ if ((png_ptr->transformations & PNG_BGR) != 0)
+ png_do_bgr(row_info, png_ptr->row_buf + 1);
+#endif
+
+#ifdef PNG_READ_PACKSWAP_SUPPORTED
+ if ((png_ptr->transformations & PNG_PACKSWAP) != 0)
+ png_do_packswap(row_info, png_ptr->row_buf + 1);
+#endif
+
+#ifdef PNG_READ_FILLER_SUPPORTED
+ if ((png_ptr->transformations & PNG_FILLER) != 0)
+ png_do_read_filler(row_info, png_ptr->row_buf + 1,
+ (png_uint_32)png_ptr->filler, png_ptr->flags);
+#endif
+
+#ifdef PNG_READ_SWAP_ALPHA_SUPPORTED
+ if ((png_ptr->transformations & PNG_SWAP_ALPHA) != 0)
+ png_do_read_swap_alpha(row_info, png_ptr->row_buf + 1);
+#endif
+
+#ifdef PNG_READ_16BIT_SUPPORTED
+#ifdef PNG_READ_SWAP_SUPPORTED
+ if ((png_ptr->transformations & PNG_SWAP_BYTES) != 0)
+ png_do_swap(row_info, png_ptr->row_buf + 1);
+#endif
+#endif
+
+#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
+ if ((png_ptr->transformations & PNG_USER_TRANSFORM) != 0)
+ {
+ if (png_ptr->read_user_transform_fn != NULL)
+ (*(png_ptr->read_user_transform_fn)) /* User read transform function */
+ (png_ptr, /* png_ptr */
+ row_info, /* row_info: */
+ /* png_uint_32 width; width of row */
+ /* png_size_t rowbytes; number of bytes in row */
+ /* png_byte color_type; color type of pixels */
+ /* png_byte bit_depth; bit depth of samples */
+ /* png_byte channels; number of channels (1-4) */
+ /* png_byte pixel_depth; bits per pixel (depth*channels) */
+ png_ptr->row_buf + 1); /* start of pixel data for row */
+#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
+ if (png_ptr->user_transform_depth != 0)
+ row_info->bit_depth = png_ptr->user_transform_depth;
+
+ if (png_ptr->user_transform_channels != 0)
+ row_info->channels = png_ptr->user_transform_channels;
+#endif
+ row_info->pixel_depth = (png_byte)(row_info->bit_depth *
+ row_info->channels);
+
+ row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_info->width);
+ }
+#endif
+}
+
+#endif /* READ_TRANSFORMS */
+#endif /* READ */
diff --git a/third_party/lpng_v163/pngrutil.c b/third_party/libpng/pngrutil.c
similarity index 85%
rename from third_party/lpng_v163/pngrutil.c
rename to third_party/libpng/pngrutil.c
index 970ec4d..6189251 100644
--- a/third_party/lpng_v163/pngrutil.c
+++ b/third_party/libpng/pngrutil.c
@@ -1,4471 +1,4529 @@
-/* pngrutil.c - utilities to read a PNG file
- *
- * Last changed in libpng 1.6.3 [July 18, 2013]
- * Copyright (c) 1998-2013 Glenn Randers-Pehrson
- * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
- * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
- *
- * This code is released under the libpng license.
- * For conditions of distribution and use, see the disclaimer
- * and license in png.h
- *
- * This file contains routines that are only called from within
- * libpng itself during the course of reading an image.
- */
-
-#include "pngpriv.h"
-
-#ifdef PNG_READ_SUPPORTED
-
-png_uint_32 PNGAPI
-png_get_uint_31(png_const_structrp png_ptr, png_const_bytep buf)
-{
- png_uint_32 uval = png_get_uint_32(buf);
-
- if (uval > PNG_UINT_31_MAX)
- png_error(png_ptr, "PNG unsigned integer out of range");
-
- return (uval);
-}
-
-#if defined(PNG_READ_gAMA_SUPPORTED) || defined(PNG_READ_cHRM_SUPPORTED)
-/* The following is a variation on the above for use with the fixed
- * point values used for gAMA and cHRM. Instead of png_error it
- * issues a warning and returns (-1) - an invalid value because both
- * gAMA and cHRM use *unsigned* integers for fixed point values.
- */
-#define PNG_FIXED_ERROR (-1)
-
-static png_fixed_point /* PRIVATE */
-png_get_fixed_point(png_structrp png_ptr, png_const_bytep buf)
-{
- png_uint_32 uval = png_get_uint_32(buf);
-
- if (uval <= PNG_UINT_31_MAX)
- return (png_fixed_point)uval; /* known to be in range */
-
- /* The caller can turn off the warning by passing NULL. */
- if (png_ptr != NULL)
- png_warning(png_ptr, "PNG fixed point integer out of range");
-
- return PNG_FIXED_ERROR;
-}
-#endif
-
-#ifdef PNG_READ_INT_FUNCTIONS_SUPPORTED
-/* NOTE: the read macros will obscure these definitions, so that if
- * PNG_USE_READ_MACROS is set the library will not use them internally,
- * but the APIs will still be available externally.
- *
- * The parentheses around "PNGAPI function_name" in the following three
- * functions are necessary because they allow the macros to co-exist with
- * these (unused but exported) functions.
- */
-
-/* Grab an unsigned 32-bit integer from a buffer in big-endian format. */
-png_uint_32 (PNGAPI
-png_get_uint_32)(png_const_bytep buf)
-{
- png_uint_32 uval =
- ((png_uint_32)(*(buf )) << 24) +
- ((png_uint_32)(*(buf + 1)) << 16) +
- ((png_uint_32)(*(buf + 2)) << 8) +
- ((png_uint_32)(*(buf + 3)) ) ;
-
- return uval;
-}
-
-/* Grab a signed 32-bit integer from a buffer in big-endian format. The
- * data is stored in the PNG file in two's complement format and there
- * is no guarantee that a 'png_int_32' is exactly 32 bits, therefore
- * the following code does a two's complement to native conversion.
- */
-png_int_32 (PNGAPI
-png_get_int_32)(png_const_bytep buf)
-{
- png_uint_32 uval = png_get_uint_32(buf);
- if ((uval & 0x80000000) == 0) /* non-negative */
- return uval;
-
- uval = (uval ^ 0xffffffff) + 1; /* 2's complement: -x = ~x+1 */
- return -(png_int_32)uval;
-}
-
-/* Grab an unsigned 16-bit integer from a buffer in big-endian format. */
-png_uint_16 (PNGAPI
-png_get_uint_16)(png_const_bytep buf)
-{
- /* ANSI-C requires an int value to accomodate at least 16 bits so this
- * works and allows the compiler not to worry about possible narrowing
- * on 32 bit systems. (Pre-ANSI systems did not make integers smaller
- * than 16 bits either.)
- */
- unsigned int val =
- ((unsigned int)(*buf) << 8) +
- ((unsigned int)(*(buf + 1)));
-
- return (png_uint_16)val;
-}
-
-#endif /* PNG_READ_INT_FUNCTIONS_SUPPORTED */
-
-/* Read and check the PNG file signature */
-void /* PRIVATE */
-png_read_sig(png_structrp png_ptr, png_inforp info_ptr)
-{
- png_size_t num_checked, num_to_check;
-
- /* Exit if the user application does not expect a signature. */
- if (png_ptr->sig_bytes >= 8)
- return;
-
- num_checked = png_ptr->sig_bytes;
- num_to_check = 8 - num_checked;
-
-#ifdef PNG_IO_STATE_SUPPORTED
- png_ptr->io_state = PNG_IO_READING | PNG_IO_SIGNATURE;
-#endif
-
- /* The signature must be serialized in a single I/O call. */
- png_read_data(png_ptr, &(info_ptr->signature[num_checked]), num_to_check);
- png_ptr->sig_bytes = 8;
-
- if (png_sig_cmp(info_ptr->signature, num_checked, num_to_check))
- {
- if (num_checked < 4 &&
- png_sig_cmp(info_ptr->signature, num_checked, num_to_check - 4))
- png_error(png_ptr, "Not a PNG file");
- else
- png_error(png_ptr, "PNG file corrupted by ASCII conversion");
- }
- if (num_checked < 3)
- png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE;
-}
-
-/* Read the chunk header (length + type name).
- * Put the type name into png_ptr->chunk_name, and return the length.
- */
-png_uint_32 /* PRIVATE */
-png_read_chunk_header(png_structrp png_ptr)
-{
- png_byte buf[8];
- png_uint_32 length;
-
-#ifdef PNG_IO_STATE_SUPPORTED
- png_ptr->io_state = PNG_IO_READING | PNG_IO_CHUNK_HDR;
-#endif
-
- /* Read the length and the chunk name.
- * This must be performed in a single I/O call.
- */
- png_read_data(png_ptr, buf, 8);
- length = png_get_uint_31(png_ptr, buf);
-
- /* Put the chunk name into png_ptr->chunk_name. */
- png_ptr->chunk_name = PNG_CHUNK_FROM_STRING(buf+4);
-
- png_debug2(0, "Reading %lx chunk, length = %lu",
- (unsigned long)png_ptr->chunk_name, (unsigned long)length);
-
- /* Reset the crc and run it over the chunk name. */
- png_reset_crc(png_ptr);
- png_calculate_crc(png_ptr, buf + 4, 4);
-
- /* Check to see if chunk name is valid. */
- png_check_chunk_name(png_ptr, png_ptr->chunk_name);
-
-#ifdef PNG_IO_STATE_SUPPORTED
- png_ptr->io_state = PNG_IO_READING | PNG_IO_CHUNK_DATA;
-#endif
-
- return length;
-}
-
-/* Read data, and (optionally) run it through the CRC. */
-void /* PRIVATE */
-png_crc_read(png_structrp png_ptr, png_bytep buf, png_uint_32 length)
-{
- if (png_ptr == NULL)
- return;
-
- png_read_data(png_ptr, buf, length);
- png_calculate_crc(png_ptr, buf, length);
-}
-
-/* Optionally skip data and then check the CRC. Depending on whether we
- * are reading an ancillary or critical chunk, and how the program has set
- * things up, we may calculate the CRC on the data and print a message.
- * Returns '1' if there was a CRC error, '0' otherwise.
- */
-int /* PRIVATE */
-png_crc_finish(png_structrp png_ptr, png_uint_32 skip)
-{
- /* The size of the local buffer for inflate is a good guess as to a
- * reasonable size to use for buffering reads from the application.
- */
- while (skip > 0)
- {
- png_uint_32 len;
- png_byte tmpbuf[PNG_INFLATE_BUF_SIZE];
-
- len = (sizeof tmpbuf);
- if (len > skip)
- len = skip;
- skip -= len;
-
- png_crc_read(png_ptr, tmpbuf, len);
- }
-
- if (png_crc_error(png_ptr))
- {
- if (PNG_CHUNK_ANCILLARY(png_ptr->chunk_name) ?
- !(png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN) :
- (png_ptr->flags & PNG_FLAG_CRC_CRITICAL_USE))
- {
- png_chunk_warning(png_ptr, "CRC error");
- }
-
- else
- {
- png_chunk_benign_error(png_ptr, "CRC error");
- return (0);
- }
-
- return (1);
- }
-
- return (0);
-}
-
-/* Compare the CRC stored in the PNG file with that calculated by libpng from
- * the data it has read thus far.
- */
-int /* PRIVATE */
-png_crc_error(png_structrp png_ptr)
-{
- png_byte crc_bytes[4];
- png_uint_32 crc;
- int need_crc = 1;
-
- if (PNG_CHUNK_ANCILLARY(png_ptr->chunk_name))
- {
- if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_MASK) ==
- (PNG_FLAG_CRC_ANCILLARY_USE | PNG_FLAG_CRC_ANCILLARY_NOWARN))
- need_crc = 0;
- }
-
- else /* critical */
- {
- if (png_ptr->flags & PNG_FLAG_CRC_CRITICAL_IGNORE)
- need_crc = 0;
- }
-
-#ifdef PNG_IO_STATE_SUPPORTED
- png_ptr->io_state = PNG_IO_READING | PNG_IO_CHUNK_CRC;
-#endif
-
- /* The chunk CRC must be serialized in a single I/O call. */
- png_read_data(png_ptr, crc_bytes, 4);
-
- if (need_crc)
- {
- crc = png_get_uint_32(crc_bytes);
- return ((int)(crc != png_ptr->crc));
- }
-
- else
- return (0);
-}
-
-/* Manage the read buffer; this simply reallocates the buffer if it is not small
- * enough (or if it is not allocated). The routine returns a pointer to the
- * buffer; if an error occurs and 'warn' is set the routine returns NULL, else
- * it will call png_error (via png_malloc) on failure. (warn == 2 means
- * 'silent').
- */
-static png_bytep
-png_read_buffer(png_structrp png_ptr, png_alloc_size_t new_size, int warn)
-{
- png_bytep buffer = png_ptr->read_buffer;
-
- if (buffer != NULL && new_size > png_ptr->read_buffer_size)
- {
- png_ptr->read_buffer = NULL;
- png_ptr->read_buffer = NULL;
- png_ptr->read_buffer_size = 0;
- png_free(png_ptr, buffer);
- buffer = NULL;
- }
-
- if (buffer == NULL)
- {
- buffer = png_voidcast(png_bytep, png_malloc_base(png_ptr, new_size));
-
- if (buffer != NULL)
- {
- png_ptr->read_buffer = buffer;
- png_ptr->read_buffer_size = new_size;
- }
-
- else if (warn < 2) /* else silent */
- {
-#ifdef PNG_WARNINGS_SUPPORTED
- if (warn)
- png_chunk_warning(png_ptr, "insufficient memory to read chunk");
- else
-#endif
- {
-#ifdef PNG_ERROR_TEXT_SUPPORTED
- png_chunk_error(png_ptr, "insufficient memory to read chunk");
-#endif
- }
- }
- }
-
- return buffer;
-}
-
-/* png_inflate_claim: claim the zstream for some nefarious purpose that involves
- * decompression. Returns Z_OK on success, else a zlib error code. It checks
- * the owner but, in final release builds, just issues a warning if some other
- * chunk apparently owns the stream. Prior to release it does a png_error.
- */
-static int
-png_inflate_claim(png_structrp png_ptr, png_uint_32 owner)
-{
- if (png_ptr->zowner != 0)
- {
- char msg[64];
-
- PNG_STRING_FROM_CHUNK(msg, png_ptr->zowner);
- /* So the message that results is "<chunk> using zstream"; this is an
- * internal error, but is very useful for debugging. i18n requirements
- * are minimal.
- */
- (void)png_safecat(msg, (sizeof msg), 4, " using zstream");
-# if PNG_LIBPNG_BUILD_BASE_TYPE >= PNG_LIBPNG_BUILD_RC
- png_chunk_warning(png_ptr, msg);
- png_ptr->zowner = 0;
-# else
- png_chunk_error(png_ptr, msg);
-# endif
- }
-
- /* Implementation note: unlike 'png_deflate_claim' this internal function
- * does not take the size of the data as an argument. Some efficiency could
- * be gained by using this when it is known *if* the zlib stream itself does
- * not record the number; however, this is an illusion: the original writer
- * of the PNG may have selected a lower window size, and we really must
- * follow that because, for systems with with limited capabilities, we
- * would otherwise reject the application's attempts to use a smaller window
- * size (zlib doesn't have an interface to say "this or lower"!).
- *
- * inflateReset2 was added to zlib 1.2.4; before this the window could not be
- * reset, therefore it is necessary to always allocate the maximum window
- * size with earlier zlibs just in case later compressed chunks need it.
- */
- {
- int ret; /* zlib return code */
-# if PNG_ZLIB_VERNUM >= 0x1240
-
-# if defined(PNG_SET_OPTION_SUPPORTED) && \
- defined(PNG_MAXIMUM_INFLATE_WINDOW)
- int window_bits;
-
- if (((png_ptr->options >> PNG_MAXIMUM_INFLATE_WINDOW) & 3) ==
- PNG_OPTION_ON)
- window_bits = 15;
-
- else
- window_bits = 0;
-# else
-# define window_bits 0
-# endif
-# endif
-
- /* Set this for safety, just in case the previous owner left pointers to
- * memory allocations.
- */
- png_ptr->zstream.next_in = NULL;
- png_ptr->zstream.avail_in = 0;
- png_ptr->zstream.next_out = NULL;
- png_ptr->zstream.avail_out = 0;
-
- if (png_ptr->flags & PNG_FLAG_ZSTREAM_INITIALIZED)
- {
-# if PNG_ZLIB_VERNUM < 0x1240
- ret = inflateReset(&png_ptr->zstream);
-# else
- ret = inflateReset2(&png_ptr->zstream, window_bits);
-# endif
- }
-
- else
- {
-# if PNG_ZLIB_VERNUM < 0x1240
- ret = inflateInit(&png_ptr->zstream);
-# else
- ret = inflateInit2(&png_ptr->zstream, window_bits);
-# endif
-
- if (ret == Z_OK)
- png_ptr->flags |= PNG_FLAG_ZSTREAM_INITIALIZED;
- }
-
- if (ret == Z_OK)
- png_ptr->zowner = owner;
-
- else
- png_zstream_error(png_ptr, ret);
-
- return ret;
- }
-
-# ifdef window_bits
-# undef window_bits
-# endif
-}
-
-#ifdef PNG_READ_COMPRESSED_TEXT_SUPPORTED
-/* png_inflate now returns zlib error codes including Z_OK and Z_STREAM_END to
- * allow the caller to do multiple calls if required. If the 'finish' flag is
- * set Z_FINISH will be passed to the final inflate() call and Z_STREAM_END must
- * be returned or there has been a problem, otherwise Z_SYNC_FLUSH is used and
- * Z_OK or Z_STREAM_END will be returned on success.
- *
- * The input and output sizes are updated to the actual amounts of data consumed
- * or written, not the amount available (as in a z_stream). The data pointers
- * are not changed, so the next input is (data+input_size) and the next
- * available output is (output+output_size).
- */
-static int
-png_inflate(png_structrp png_ptr, png_uint_32 owner, int finish,
- /* INPUT: */ png_const_bytep input, png_uint_32p input_size_ptr,
- /* OUTPUT: */ png_bytep output, png_alloc_size_t *output_size_ptr)
-{
- if (png_ptr->zowner == owner) /* Else not claimed */
- {
- int ret;
- png_alloc_size_t avail_out = *output_size_ptr;
- png_uint_32 avail_in = *input_size_ptr;
-
- /* zlib can't necessarily handle more than 65535 bytes at once (i.e. it
- * can't even necessarily handle 65536 bytes) because the type uInt is
- * "16 bits or more". Consequently it is necessary to chunk the input to
- * zlib. This code uses ZLIB_IO_MAX, from pngpriv.h, as the maximum (the
- * maximum value that can be stored in a uInt.) It is possible to set
- * ZLIB_IO_MAX to a lower value in pngpriv.h and this may sometimes have
- * a performance advantage, because it reduces the amount of data accessed
- * at each step and that may give the OS more time to page it in.
- */
- png_ptr->zstream.next_in = PNGZ_INPUT_CAST(input);
- /* avail_in and avail_out are set below from 'size' */
- png_ptr->zstream.avail_in = 0;
- png_ptr->zstream.avail_out = 0;
-
- /* Read directly into the output if it is available (this is set to
- * a local buffer below if output is NULL).
- */
- if (output != NULL)
- png_ptr->zstream.next_out = output;
-
- do
- {
- uInt avail;
- Byte local_buffer[PNG_INFLATE_BUF_SIZE];
-
- /* zlib INPUT BUFFER */
- /* The setting of 'avail_in' used to be outside the loop; by setting it
- * inside it is possible to chunk the input to zlib and simply rely on
- * zlib to advance the 'next_in' pointer. This allows arbitrary
- * amounts of data to be passed through zlib at the unavoidable cost of
- * requiring a window save (memcpy of up to 32768 output bytes)
- * every ZLIB_IO_MAX input bytes.
- */
- avail_in += png_ptr->zstream.avail_in; /* not consumed last time */
-
- avail = ZLIB_IO_MAX;
-
- if (avail_in < avail)
- avail = (uInt)avail_in; /* safe: < than ZLIB_IO_MAX */
-
- avail_in -= avail;
- png_ptr->zstream.avail_in = avail;
-
- /* zlib OUTPUT BUFFER */
- avail_out += png_ptr->zstream.avail_out; /* not written last time */
-
- avail = ZLIB_IO_MAX; /* maximum zlib can process */
-
- if (output == NULL)
- {
- /* Reset the output buffer each time round if output is NULL and
- * make available the full buffer, up to 'remaining_space'
- */
- png_ptr->zstream.next_out = local_buffer;
- if ((sizeof local_buffer) < avail)
- avail = (sizeof local_buffer);
- }
-
- if (avail_out < avail)
- avail = (uInt)avail_out; /* safe: < ZLIB_IO_MAX */
-
- png_ptr->zstream.avail_out = avail;
- avail_out -= avail;
-
- /* zlib inflate call */
- /* In fact 'avail_out' may be 0 at this point, that happens at the end
- * of the read when the final LZ end code was not passed at the end of
- * the previous chunk of input data. Tell zlib if we have reached the
- * end of the output buffer.
- */
- ret = inflate(&png_ptr->zstream, avail_out > 0 ? Z_NO_FLUSH :
- (finish ? Z_FINISH : Z_SYNC_FLUSH));
- } while (ret == Z_OK);
-
- /* For safety kill the local buffer pointer now */
- if (output == NULL)
- png_ptr->zstream.next_out = NULL;
-
- /* Claw back the 'size' and 'remaining_space' byte counts. */
- avail_in += png_ptr->zstream.avail_in;
- avail_out += png_ptr->zstream.avail_out;
-
- /* Update the input and output sizes; the updated values are the amount
- * consumed or written, effectively the inverse of what zlib uses.
- */
- if (avail_out > 0)
- *output_size_ptr -= avail_out;
-
- if (avail_in > 0)
- *input_size_ptr -= avail_in;
-
- /* Ensure png_ptr->zstream.msg is set (even in the success case!) */
- png_zstream_error(png_ptr, ret);
- return ret;
- }
-
- else
- {
- /* This is a bad internal error. The recovery assigns to the zstream msg
- * pointer, which is not owned by the caller, but this is safe; it's only
- * used on errors!
- */
- png_ptr->zstream.msg = PNGZ_MSG_CAST("zstream unclaimed");
- return Z_STREAM_ERROR;
- }
-}
-
-/*
- * Decompress trailing data in a chunk. The assumption is that read_buffer
- * points at an allocated area holding the contents of a chunk with a
- * trailing compressed part. What we get back is an allocated area
- * holding the original prefix part and an uncompressed version of the
- * trailing part (the malloc area passed in is freed).
- */
-static int
-png_decompress_chunk(png_structrp png_ptr,
- png_uint_32 chunklength, png_uint_32 prefix_size,
- png_alloc_size_t *newlength /* must be initialized to the maximum! */,
- int terminate /*add a '\0' to the end of the uncompressed data*/)
-{
- /* TODO: implement different limits for different types of chunk.
- *
- * The caller supplies *newlength set to the maximum length of the
- * uncompressed data, but this routine allocates space for the prefix and
- * maybe a '\0' terminator too. We have to assume that 'prefix_size' is
- * limited only by the maximum chunk size.
- */
- png_alloc_size_t limit = PNG_SIZE_MAX;
-
-# ifdef PNG_SET_CHUNK_MALLOC_LIMIT_SUPPORTED
- if (png_ptr->user_chunk_malloc_max > 0 &&
- png_ptr->user_chunk_malloc_max < limit)
- limit = png_ptr->user_chunk_malloc_max;
-# elif PNG_USER_CHUNK_MALLOC_MAX > 0
- if (PNG_USER_CHUNK_MALLOC_MAX < limit)
- limit = PNG_USER_CHUNK_MALLOC_MAX;
-# endif
-
- if (limit >= prefix_size + (terminate != 0))
- {
- int ret;
-
- limit -= prefix_size + (terminate != 0);
-
- if (limit < *newlength)
- *newlength = limit;
-
- /* Now try to claim the stream. */
- ret = png_inflate_claim(png_ptr, png_ptr->chunk_name);
-
- if (ret == Z_OK)
- {
- png_uint_32 lzsize = chunklength - prefix_size;
-
- ret = png_inflate(png_ptr, png_ptr->chunk_name, 1/*finish*/,
- /* input: */ png_ptr->read_buffer + prefix_size, &lzsize,
- /* output: */ NULL, newlength);
-
- if (ret == Z_STREAM_END)
- {
- /* Use 'inflateReset' here, not 'inflateReset2' because this
- * preserves the previously decided window size (otherwise it would
- * be necessary to store the previous window size.) In practice
- * this doesn't matter anyway, because png_inflate will call inflate
- * with Z_FINISH in almost all cases, so the window will not be
- * maintained.
- */
- if (inflateReset(&png_ptr->zstream) == Z_OK)
- {
- /* Because of the limit checks above we know that the new,
- * expanded, size will fit in a size_t (let alone an
- * png_alloc_size_t). Use png_malloc_base here to avoid an
- * extra OOM message.
- */
- png_alloc_size_t new_size = *newlength;
- png_alloc_size_t buffer_size = prefix_size + new_size +
- (terminate != 0);
- png_bytep text = png_voidcast(png_bytep, png_malloc_base(png_ptr,
- buffer_size));
-
- if (text != NULL)
- {
- ret = png_inflate(png_ptr, png_ptr->chunk_name, 1/*finish*/,
- png_ptr->read_buffer + prefix_size, &lzsize,
- text + prefix_size, newlength);
-
- if (ret == Z_STREAM_END)
- {
- if (new_size == *newlength)
- {
- if (terminate)
- text[prefix_size + *newlength] = 0;
-
- if (prefix_size > 0)
- memcpy(text, png_ptr->read_buffer, prefix_size);
-
- {
- png_bytep old_ptr = png_ptr->read_buffer;
-
- png_ptr->read_buffer = text;
- png_ptr->read_buffer_size = buffer_size;
- text = old_ptr; /* freed below */
- }
- }
-
- else
- {
- /* The size changed on the second read, there can be no
- * guarantee that anything is correct at this point.
- * The 'msg' pointer has been set to "unexpected end of
- * LZ stream", which is fine, but return an error code
- * that the caller won't accept.
- */
- ret = PNG_UNEXPECTED_ZLIB_RETURN;
- }
- }
-
- else if (ret == Z_OK)
- ret = PNG_UNEXPECTED_ZLIB_RETURN; /* for safety */
-
- /* Free the text pointer (this is the old read_buffer on
- * success)
- */
- png_free(png_ptr, text);
-
- /* This really is very benign, but it's still an error because
- * the extra space may otherwise be used as a Trojan Horse.
- */
- if (ret == Z_STREAM_END &&
- chunklength - prefix_size != lzsize)
- png_chunk_benign_error(png_ptr, "extra compressed data");
- }
-
- else
- {
- /* Out of memory allocating the buffer */
- ret = Z_MEM_ERROR;
- png_zstream_error(png_ptr, Z_MEM_ERROR);
- }
- }
-
- else
- {
- /* inflateReset failed, store the error message */
- png_zstream_error(png_ptr, ret);
-
- if (ret == Z_STREAM_END)
- ret = PNG_UNEXPECTED_ZLIB_RETURN;
- }
- }
-
- else if (ret == Z_OK)
- ret = PNG_UNEXPECTED_ZLIB_RETURN;
-
- /* Release the claimed stream */
- png_ptr->zowner = 0;
- }
-
- else /* the claim failed */ if (ret == Z_STREAM_END) /* impossible! */
- ret = PNG_UNEXPECTED_ZLIB_RETURN;
-
- return ret;
- }
-
- else
- {
- /* Application/configuration limits exceeded */
- png_zstream_error(png_ptr, Z_MEM_ERROR);
- return Z_MEM_ERROR;
- }
-}
-#endif /* PNG_READ_COMPRESSED_TEXT_SUPPORTED */
-
-#ifdef PNG_READ_iCCP_SUPPORTED
-/* Perform a partial read and decompress, producing 'avail_out' bytes and
- * reading from the current chunk as required.
- */
-static int
-png_inflate_read(png_structrp png_ptr, png_bytep read_buffer, uInt read_size,
- png_uint_32p chunk_bytes, png_bytep next_out, png_alloc_size_t *out_size,
- int finish)
-{
- if (png_ptr->zowner == png_ptr->chunk_name)
- {
- int ret;
-
- /* next_in and avail_in must have been initialized by the caller. */
- png_ptr->zstream.next_out = next_out;
- png_ptr->zstream.avail_out = 0; /* set in the loop */
-
- do
- {
- if (png_ptr->zstream.avail_in == 0)
- {
- if (read_size > *chunk_bytes)
- read_size = (uInt)*chunk_bytes;
- *chunk_bytes -= read_size;
-
- if (read_size > 0)
- png_crc_read(png_ptr, read_buffer, read_size);
-
- png_ptr->zstream.next_in = read_buffer;
- png_ptr->zstream.avail_in = read_size;
- }
-
- if (png_ptr->zstream.avail_out == 0)
- {
- uInt avail = ZLIB_IO_MAX;
- if (avail > *out_size)
- avail = (uInt)*out_size;
- *out_size -= avail;
-
- png_ptr->zstream.avail_out = avail;
- }
-
- /* Use Z_SYNC_FLUSH when there is no more chunk data to ensure that all
- * the available output is produced; this allows reading of truncated
- * streams.
- */
- ret = inflate(&png_ptr->zstream,
- *chunk_bytes > 0 ? Z_NO_FLUSH : (finish ? Z_FINISH : Z_SYNC_FLUSH));
- }
- while (ret == Z_OK && (*out_size > 0 || png_ptr->zstream.avail_out > 0));
-
- *out_size += png_ptr->zstream.avail_out;
- png_ptr->zstream.avail_out = 0; /* Should not be required, but is safe */
-
- /* Ensure the error message pointer is always set: */
- png_zstream_error(png_ptr, ret);
- return ret;
- }
-
- else
- {
- png_ptr->zstream.msg = PNGZ_MSG_CAST("zstream unclaimed");
- return Z_STREAM_ERROR;
- }
-}
-#endif
-
-/* Read and check the IDHR chunk */
-void /* PRIVATE */
-png_handle_IHDR(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
-{
- png_byte buf[13];
- png_uint_32 width, height;
- int bit_depth, color_type, compression_type, filter_type;
- int interlace_type;
-
- png_debug(1, "in png_handle_IHDR");
-
- if (png_ptr->mode & PNG_HAVE_IHDR)
- png_chunk_error(png_ptr, "out of place");
-
- /* Check the length */
- if (length != 13)
- png_chunk_error(png_ptr, "invalid");
-
- png_ptr->mode |= PNG_HAVE_IHDR;
-
- png_crc_read(png_ptr, buf, 13);
- png_crc_finish(png_ptr, 0);
-
- width = png_get_uint_31(png_ptr, buf);
- height = png_get_uint_31(png_ptr, buf + 4);
- bit_depth = buf[8];
- color_type = buf[9];
- compression_type = buf[10];
- filter_type = buf[11];
- interlace_type = buf[12];
-
- /* Set internal variables */
- png_ptr->width = width;
- png_ptr->height = height;
- png_ptr->bit_depth = (png_byte)bit_depth;
- png_ptr->interlaced = (png_byte)interlace_type;
- png_ptr->color_type = (png_byte)color_type;
-#ifdef PNG_MNG_FEATURES_SUPPORTED
- png_ptr->filter_type = (png_byte)filter_type;
-#endif
- png_ptr->compression_type = (png_byte)compression_type;
-
- /* Find number of channels */
- switch (png_ptr->color_type)
- {
- default: /* invalid, png_set_IHDR calls png_error */
- case PNG_COLOR_TYPE_GRAY:
- case PNG_COLOR_TYPE_PALETTE:
- png_ptr->channels = 1;
- break;
-
- case PNG_COLOR_TYPE_RGB:
- png_ptr->channels = 3;
- break;
-
- case PNG_COLOR_TYPE_GRAY_ALPHA:
- png_ptr->channels = 2;
- break;
-
- case PNG_COLOR_TYPE_RGB_ALPHA:
- png_ptr->channels = 4;
- break;
- }
-
- /* Set up other useful info */
- png_ptr->pixel_depth = (png_byte)(png_ptr->bit_depth *
- png_ptr->channels);
- png_ptr->rowbytes = PNG_ROWBYTES(png_ptr->pixel_depth, png_ptr->width);
- png_debug1(3, "bit_depth = %d", png_ptr->bit_depth);
- png_debug1(3, "channels = %d", png_ptr->channels);
- png_debug1(3, "rowbytes = %lu", (unsigned long)png_ptr->rowbytes);
- png_set_IHDR(png_ptr, info_ptr, width, height, bit_depth,
- color_type, interlace_type, compression_type, filter_type);
-}
-
-/* Read and check the palette */
-void /* PRIVATE */
-png_handle_PLTE(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
-{
- png_color palette[PNG_MAX_PALETTE_LENGTH];
- int num, i;
-#ifdef PNG_POINTER_INDEXING_SUPPORTED
- png_colorp pal_ptr;
-#endif
-
- png_debug(1, "in png_handle_PLTE");
-
- if (!(png_ptr->mode & PNG_HAVE_IHDR))
- png_chunk_error(png_ptr, "missing IHDR");
-
- /* Moved to before the 'after IDAT' check below because otherwise duplicate
- * PLTE chunks are potentially ignored (the spec says there shall not be more
- * than one PLTE, the error is not treated as benign, so this check trumps
- * the requirement that PLTE appears before IDAT.)
- */
- else if (png_ptr->mode & PNG_HAVE_PLTE)
- png_chunk_error(png_ptr, "duplicate");
-
- else if (png_ptr->mode & PNG_HAVE_IDAT)
- {
- /* This is benign because the non-benign error happened before, when an
- * IDAT was encountered in a color-mapped image with no PLTE.
- */
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "out of place");
- return;
- }
-
- png_ptr->mode |= PNG_HAVE_PLTE;
-
- if (!(png_ptr->color_type & PNG_COLOR_MASK_COLOR))
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "ignored in grayscale PNG");
- return;
- }
-
-#ifndef PNG_READ_OPT_PLTE_SUPPORTED
- if (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE)
- {
- png_crc_finish(png_ptr, length);
- return;
- }
-#endif
-
- if (length > 3*PNG_MAX_PALETTE_LENGTH || length % 3)
- {
- png_crc_finish(png_ptr, length);
-
- if (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE)
- png_chunk_benign_error(png_ptr, "invalid");
-
- else
- png_chunk_error(png_ptr, "invalid");
-
- return;
- }
-
- /* The cast is safe because 'length' is less than 3*PNG_MAX_PALETTE_LENGTH */
- num = (int)length / 3;
-
-#ifdef PNG_POINTER_INDEXING_SUPPORTED
- for (i = 0, pal_ptr = palette; i < num; i++, pal_ptr++)
- {
- png_byte buf[3];
-
- png_crc_read(png_ptr, buf, 3);
- pal_ptr->red = buf[0];
- pal_ptr->green = buf[1];
- pal_ptr->blue = buf[2];
- }
-#else
- for (i = 0; i < num; i++)
- {
- png_byte buf[3];
-
- png_crc_read(png_ptr, buf, 3);
- /* Don't depend upon png_color being any order */
- palette[i].red = buf[0];
- palette[i].green = buf[1];
- palette[i].blue = buf[2];
- }
-#endif
-
- /* If we actually need the PLTE chunk (ie for a paletted image), we do
- * whatever the normal CRC configuration tells us. However, if we
- * have an RGB image, the PLTE can be considered ancillary, so
- * we will act as though it is.
- */
-#ifndef PNG_READ_OPT_PLTE_SUPPORTED
- if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
-#endif
- {
- png_crc_finish(png_ptr, 0);
- }
-
-#ifndef PNG_READ_OPT_PLTE_SUPPORTED
- else if (png_crc_error(png_ptr)) /* Only if we have a CRC error */
- {
- /* If we don't want to use the data from an ancillary chunk,
- * we have two options: an error abort, or a warning and we
- * ignore the data in this chunk (which should be OK, since
- * it's considered ancillary for a RGB or RGBA image).
- *
- * IMPLEMENTATION NOTE: this is only here because png_crc_finish uses the
- * chunk type to determine whether to check the ancillary or the critical
- * flags.
- */
- if (!(png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_USE))
- {
- if (png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN)
- {
- png_chunk_benign_error(png_ptr, "CRC error");
- }
-
- else
- {
- png_chunk_warning(png_ptr, "CRC error");
- return;
- }
- }
-
- /* Otherwise, we (optionally) emit a warning and use the chunk. */
- else if (!(png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN))
- {
- png_chunk_warning(png_ptr, "CRC error");
- }
- }
-#endif
-
- /* TODO: png_set_PLTE has the side effect of setting png_ptr->palette to its
- * own copy of the palette. This has the side effect that when png_start_row
- * is called (this happens after any call to png_read_update_info) the
- * info_ptr palette gets changed. This is extremely unexpected and
- * confusing.
- *
- * Fix this by not sharing the palette in this way.
- */
- png_set_PLTE(png_ptr, info_ptr, palette, num);
-
- /* The three chunks, bKGD, hIST and tRNS *must* appear after PLTE and before
- * IDAT. Prior to 1.6.0 this was not checked; instead the code merely
- * checked the apparent validity of a tRNS chunk inserted before PLTE on a
- * palette PNG. 1.6.0 attempts to rigorously follow the standard and
- * therefore does a benign error if the erroneous condition is detected *and*
- * cancels the tRNS if the benign error returns. The alternative is to
- * amend the standard since it would be rather hypocritical of the standards
- * maintainers to ignore it.
- */
-#ifdef PNG_READ_tRNS_SUPPORTED
- if (png_ptr->num_trans > 0 ||
- (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tRNS) != 0))
- {
- /* Cancel this because otherwise it would be used if the transforms
- * require it. Don't cancel the 'valid' flag because this would prevent
- * detection of duplicate chunks.
- */
- png_ptr->num_trans = 0;
-
- if (info_ptr != NULL)
- info_ptr->num_trans = 0;
-
- png_chunk_benign_error(png_ptr, "tRNS must be after");
- }
-#endif
-
-#ifdef PNG_READ_hIST_SUPPORTED
- if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_hIST) != 0)
- png_chunk_benign_error(png_ptr, "hIST must be after");
-#endif
-
-#ifdef PNG_READ_bKGD_SUPPORTED
- if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_bKGD) != 0)
- png_chunk_benign_error(png_ptr, "bKGD must be after");
-#endif
-}
-
-void /* PRIVATE */
-png_handle_IEND(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
-{
- png_debug(1, "in png_handle_IEND");
-
- if (!(png_ptr->mode & PNG_HAVE_IHDR) || !(png_ptr->mode & PNG_HAVE_IDAT))
- png_chunk_error(png_ptr, "out of place");
-
- png_ptr->mode |= (PNG_AFTER_IDAT | PNG_HAVE_IEND);
-
- png_crc_finish(png_ptr, length);
-
- if (length != 0)
- png_chunk_benign_error(png_ptr, "invalid");
-
- PNG_UNUSED(info_ptr)
-}
-
-#ifdef PNG_READ_gAMA_SUPPORTED
-void /* PRIVATE */
-png_handle_gAMA(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
-{
- png_fixed_point igamma;
- png_byte buf[4];
-
- png_debug(1, "in png_handle_gAMA");
-
- if (!(png_ptr->mode & PNG_HAVE_IHDR))
- png_chunk_error(png_ptr, "missing IHDR");
-
- else if (png_ptr->mode & (PNG_HAVE_IDAT|PNG_HAVE_PLTE))
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "out of place");
- return;
- }
-
- if (length != 4)
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "invalid");
- return;
- }
-
- png_crc_read(png_ptr, buf, 4);
-
- if (png_crc_finish(png_ptr, 0))
- return;
-
- igamma = png_get_fixed_point(NULL, buf);
-
- png_colorspace_set_gamma(png_ptr, &png_ptr->colorspace, igamma);
- png_colorspace_sync(png_ptr, info_ptr);
-}
-#endif
-
-#ifdef PNG_READ_sBIT_SUPPORTED
-void /* PRIVATE */
-png_handle_sBIT(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
-{
- unsigned int truelen;
- png_byte buf[4];
-
- png_debug(1, "in png_handle_sBIT");
-
- buf[0] = buf[1] = buf[2] = buf[3] = 0;
-
- if (!(png_ptr->mode & PNG_HAVE_IHDR))
- png_chunk_error(png_ptr, "missing IHDR");
-
- else if (png_ptr->mode & (PNG_HAVE_IDAT|PNG_HAVE_PLTE))
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "out of place");
- return;
- }
-
- if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sBIT))
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "duplicate");
- return;
- }
-
- if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
- truelen = 3;
-
- else
- truelen = png_ptr->channels;
-
- if (length != truelen || length > 4)
- {
- png_chunk_benign_error(png_ptr, "invalid");
- png_crc_finish(png_ptr, length);
- return;
- }
-
- png_crc_read(png_ptr, buf, truelen);
-
- if (png_crc_finish(png_ptr, 0))
- return;
-
- if (png_ptr->color_type & PNG_COLOR_MASK_COLOR)
- {
- png_ptr->sig_bit.red = buf[0];
- png_ptr->sig_bit.green = buf[1];
- png_ptr->sig_bit.blue = buf[2];
- png_ptr->sig_bit.alpha = buf[3];
- }
-
- else
- {
- png_ptr->sig_bit.gray = buf[0];
- png_ptr->sig_bit.red = buf[0];
- png_ptr->sig_bit.green = buf[0];
- png_ptr->sig_bit.blue = buf[0];
- png_ptr->sig_bit.alpha = buf[1];
- }
-
- png_set_sBIT(png_ptr, info_ptr, &(png_ptr->sig_bit));
-}
-#endif
-
-#ifdef PNG_READ_cHRM_SUPPORTED
-void /* PRIVATE */
-png_handle_cHRM(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
-{
- png_byte buf[32];
- png_xy xy;
-
- png_debug(1, "in png_handle_cHRM");
-
- if (!(png_ptr->mode & PNG_HAVE_IHDR))
- png_chunk_error(png_ptr, "missing IHDR");
-
- else if (png_ptr->mode & (PNG_HAVE_IDAT|PNG_HAVE_PLTE))
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "out of place");
- return;
- }
-
- if (length != 32)
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "invalid");
- return;
- }
-
- png_crc_read(png_ptr, buf, 32);
-
- if (png_crc_finish(png_ptr, 0))
- return;
-
- xy.whitex = png_get_fixed_point(NULL, buf);
- xy.whitey = png_get_fixed_point(NULL, buf + 4);
- xy.redx = png_get_fixed_point(NULL, buf + 8);
- xy.redy = png_get_fixed_point(NULL, buf + 12);
- xy.greenx = png_get_fixed_point(NULL, buf + 16);
- xy.greeny = png_get_fixed_point(NULL, buf + 20);
- xy.bluex = png_get_fixed_point(NULL, buf + 24);
- xy.bluey = png_get_fixed_point(NULL, buf + 28);
-
- if (xy.whitex == PNG_FIXED_ERROR ||
- xy.whitey == PNG_FIXED_ERROR ||
- xy.redx == PNG_FIXED_ERROR ||
- xy.redy == PNG_FIXED_ERROR ||
- xy.greenx == PNG_FIXED_ERROR ||
- xy.greeny == PNG_FIXED_ERROR ||
- xy.bluex == PNG_FIXED_ERROR ||
- xy.bluey == PNG_FIXED_ERROR)
- {
- png_chunk_benign_error(png_ptr, "invalid values");
- return;
- }
-
- /* If a colorspace error has already been output skip this chunk */
- if (png_ptr->colorspace.flags & PNG_COLORSPACE_INVALID)
- return;
-
- if (png_ptr->colorspace.flags & PNG_COLORSPACE_FROM_cHRM)
- {
- png_ptr->colorspace.flags |= PNG_COLORSPACE_INVALID;
- png_colorspace_sync(png_ptr, info_ptr);
- png_chunk_benign_error(png_ptr, "duplicate");
- return;
- }
-
- png_ptr->colorspace.flags |= PNG_COLORSPACE_FROM_cHRM;
- (void)png_colorspace_set_chromaticities(png_ptr, &png_ptr->colorspace, &xy,
- 1/*prefer cHRM values*/);
- png_colorspace_sync(png_ptr, info_ptr);
-}
-#endif
-
-#ifdef PNG_READ_sRGB_SUPPORTED
-void /* PRIVATE */
-png_handle_sRGB(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
-{
- png_byte intent;
-
- png_debug(1, "in png_handle_sRGB");
-
- if (!(png_ptr->mode & PNG_HAVE_IHDR))
- png_chunk_error(png_ptr, "missing IHDR");
-
- else if (png_ptr->mode & (PNG_HAVE_IDAT|PNG_HAVE_PLTE))
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "out of place");
- return;
- }
-
- if (length != 1)
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "invalid");
- return;
- }
-
- png_crc_read(png_ptr, &intent, 1);
-
- if (png_crc_finish(png_ptr, 0))
- return;
-
- /* If a colorspace error has already been output skip this chunk */
- if (png_ptr->colorspace.flags & PNG_COLORSPACE_INVALID)
- return;
-
- /* Only one sRGB or iCCP chunk is allowed, use the HAVE_INTENT flag to detect
- * this.
- */
- if (png_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_INTENT)
- {
- png_ptr->colorspace.flags |= PNG_COLORSPACE_INVALID;
- png_colorspace_sync(png_ptr, info_ptr);
- png_chunk_benign_error(png_ptr, "too many profiles");
- return;
- }
-
- (void)png_colorspace_set_sRGB(png_ptr, &png_ptr->colorspace, intent);
- png_colorspace_sync(png_ptr, info_ptr);
-}
-#endif /* PNG_READ_sRGB_SUPPORTED */
-
-#ifdef PNG_READ_iCCP_SUPPORTED
-void /* PRIVATE */
-png_handle_iCCP(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
-/* Note: this does not properly handle profiles that are > 64K under DOS */
-{
- png_const_charp errmsg = NULL; /* error message output, or no error */
- int finished = 0; /* crc checked */
-
- png_debug(1, "in png_handle_iCCP");
-
- if (!(png_ptr->mode & PNG_HAVE_IHDR))
- png_chunk_error(png_ptr, "missing IHDR");
-
- else if (png_ptr->mode & (PNG_HAVE_IDAT|PNG_HAVE_PLTE))
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "out of place");
- return;
- }
-
- /* Consistent with all the above colorspace handling an obviously *invalid*
- * chunk is just ignored, so does not invalidate the color space. An
- * alternative is to set the 'invalid' flags at the start of this routine
- * and only clear them in they were not set before and all the tests pass.
- * The minimum 'deflate' stream is assumed to be just the 2 byte header and 4
- * byte checksum. The keyword must be one character and there is a
- * terminator (0) byte and the compression method.
- */
- if (length < 9)
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "too short");
- return;
- }
-
- /* If a colorspace error has already been output skip this chunk */
- if (png_ptr->colorspace.flags & PNG_COLORSPACE_INVALID)
- {
- png_crc_finish(png_ptr, length);
- return;
- }
-
- /* Only one sRGB or iCCP chunk is allowed, use the HAVE_INTENT flag to detect
- * this.
- */
- if ((png_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_INTENT) == 0)
- {
- uInt read_length, keyword_length;
- char keyword[81];
-
- /* Find the keyword; the keyword plus separator and compression method
- * bytes can be at most 81 characters long.
- */
- read_length = 81; /* maximum */
- if (read_length > length)
- read_length = (uInt)length;
-
- png_crc_read(png_ptr, (png_bytep)keyword, read_length);
- length -= read_length;
-
- keyword_length = 0;
- while (keyword_length < 80 && keyword_length < read_length &&
- keyword[keyword_length] != 0)
- ++keyword_length;
-
- /* TODO: make the keyword checking common */
- if (keyword_length >= 1 && keyword_length <= 79)
- {
- /* We only understand '0' compression - deflate - so if we get a
- * different value we can't safely decode the chunk.
- */
- if (keyword_length+1 < read_length &&
- keyword[keyword_length+1] == PNG_COMPRESSION_TYPE_BASE)
- {
- read_length -= keyword_length+2;
-
- if (png_inflate_claim(png_ptr, png_iCCP) == Z_OK)
- {
- Byte profile_header[132];
- Byte local_buffer[PNG_INFLATE_BUF_SIZE];
- png_alloc_size_t size = (sizeof profile_header);
-
- png_ptr->zstream.next_in = (Bytef*)keyword + (keyword_length+2);
- png_ptr->zstream.avail_in = read_length;
- (void)png_inflate_read(png_ptr, local_buffer,
- (sizeof local_buffer), &length, profile_header, &size,
- 0/*finish: don't, because the output is too small*/);
-
- if (size == 0)
- {
- /* We have the ICC profile header; do the basic header checks.
- */
- const png_uint_32 profile_length =
- png_get_uint_32(profile_header);
-
- if (png_icc_check_length(png_ptr, &png_ptr->colorspace,
- keyword, profile_length))
- {
- /* The length is apparently ok, so we can check the 132
- * byte header.
- */
- if (png_icc_check_header(png_ptr, &png_ptr->colorspace,
- keyword, profile_length, profile_header,
- png_ptr->color_type))
- {
- /* Now read the tag table; a variable size buffer is
- * needed at this point, allocate one for the whole
- * profile. The header check has already validated
- * that none of these stuff will overflow.
- */
- const png_uint_32 tag_count = png_get_uint_32(
- profile_header+128);
- png_bytep profile = png_read_buffer(png_ptr,
- profile_length, 2/*silent*/);
-
- if (profile != NULL)
- {
- memcpy(profile, profile_header,
- (sizeof profile_header));
-
- size = 12 * tag_count;
-
- (void)png_inflate_read(png_ptr, local_buffer,
- (sizeof local_buffer), &length,
- profile + (sizeof profile_header), &size, 0);
-
- /* Still expect a a buffer error because we expect
- * there to be some tag data!
- */
- if (size == 0)
- {
- if (png_icc_check_tag_table(png_ptr,
- &png_ptr->colorspace, keyword, profile_length,
- profile))
- {
- /* The profile has been validated for basic
- * security issues, so read the whole thing in.
- */
- size = profile_length - (sizeof profile_header)
- - 12 * tag_count;
-
- (void)png_inflate_read(png_ptr, local_buffer,
- (sizeof local_buffer), &length,
- profile + (sizeof profile_header) +
- 12 * tag_count, &size, 1/*finish*/);
-
- if (length > 0 && !(png_ptr->flags &
- PNG_FLAG_BENIGN_ERRORS_WARN))
- errmsg = "extra compressed data";
-
- /* But otherwise allow extra data: */
- else if (size == 0)
- {
- if (length > 0)
- {
- /* This can be handled completely, so
- * keep going.
- */
- png_chunk_warning(png_ptr,
- "extra compressed data");
- }
-
- png_crc_finish(png_ptr, length);
- finished = 1;
-
-# ifdef PNG_sRGB_SUPPORTED
- /* Check for a match against sRGB */
- png_icc_set_sRGB(png_ptr,
- &png_ptr->colorspace, profile,
- png_ptr->zstream.adler);
-# endif
-
- /* Steal the profile for info_ptr. */
- if (info_ptr != NULL)
- {
- png_free_data(png_ptr, info_ptr,
- PNG_FREE_ICCP, 0);
-
- info_ptr->iccp_name = png_voidcast(char*,
- png_malloc_base(png_ptr,
- keyword_length+1));
- if (info_ptr->iccp_name != NULL)
- {
- memcpy(info_ptr->iccp_name, keyword,
- keyword_length+1);
- info_ptr->iccp_proflen =
- profile_length;
- info_ptr->iccp_profile = profile;
- png_ptr->read_buffer = NULL; /*steal*/
- info_ptr->free_me |= PNG_FREE_ICCP;
- info_ptr->valid |= PNG_INFO_iCCP;
- }
-
- else
- {
- png_ptr->colorspace.flags |=
- PNG_COLORSPACE_INVALID;
- errmsg = "out of memory";
- }
- }
-
- /* else the profile remains in the read
- * buffer which gets reused for subsequent
- * chunks.
- */
-
- if (info_ptr != NULL)
- png_colorspace_sync(png_ptr, info_ptr);
-
- if (errmsg == NULL)
- {
- png_ptr->zowner = 0;
- return;
- }
- }
-
- else if (size > 0)
- errmsg = "truncated";
-
- else
- errmsg = png_ptr->zstream.msg;
- }
-
- /* else png_icc_check_tag_table output an error */
- }
-
- else /* profile truncated */
- errmsg = png_ptr->zstream.msg;
- }
-
- else
- errmsg = "out of memory";
- }
-
- /* else png_icc_check_header output an error */
- }
-
- /* else png_icc_check_length output an error */
- }
-
- else /* profile truncated */
- errmsg = png_ptr->zstream.msg;
-
- /* Release the stream */
- png_ptr->zowner = 0;
- }
-
- else /* png_inflate_claim failed */
- errmsg = png_ptr->zstream.msg;
- }
-
- else
- errmsg = "bad compression method"; /* or missing */
- }
-
- else
- errmsg = "bad keyword";
- }
-
- else
- errmsg = "too many profiles";
-
- /* Failure: the reason is in 'errmsg' */
- if (!finished)
- png_crc_finish(png_ptr, length);
-
- png_ptr->colorspace.flags |= PNG_COLORSPACE_INVALID;
- png_colorspace_sync(png_ptr, info_ptr);
- if (errmsg != NULL) /* else already output */
- png_chunk_benign_error(png_ptr, errmsg);
-}
-#endif /* PNG_READ_iCCP_SUPPORTED */
-
-#ifdef PNG_READ_sPLT_SUPPORTED
-void /* PRIVATE */
-png_handle_sPLT(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
-/* Note: this does not properly handle chunks that are > 64K under DOS */
-{
- png_bytep entry_start, buffer;
- png_sPLT_t new_palette;
- png_sPLT_entryp pp;
- png_uint_32 data_length;
- int entry_size, i;
- png_uint_32 skip = 0;
- png_uint_32 dl;
- png_size_t max_dl;
-
- png_debug(1, "in png_handle_sPLT");
-
-#ifdef PNG_USER_LIMITS_SUPPORTED
- if (png_ptr->user_chunk_cache_max != 0)
- {
- if (png_ptr->user_chunk_cache_max == 1)
- {
- png_crc_finish(png_ptr, length);
- return;
- }
-
- if (--png_ptr->user_chunk_cache_max == 1)
- {
- png_warning(png_ptr, "No space in chunk cache for sPLT");
- png_crc_finish(png_ptr, length);
- return;
- }
- }
-#endif
-
- if (!(png_ptr->mode & PNG_HAVE_IHDR))
- png_chunk_error(png_ptr, "missing IHDR");
-
- else if (png_ptr->mode & PNG_HAVE_IDAT)
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "out of place");
- return;
- }
-
-#ifdef PNG_MAX_MALLOC_64K
- if (length > 65535U)
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "too large to fit in memory");
- return;
- }
-#endif
-
- buffer = png_read_buffer(png_ptr, length+1, 2/*silent*/);
- if (buffer == NULL)
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "out of memory");
- return;
- }
-
-
- /* WARNING: this may break if size_t is less than 32 bits; it is assumed
- * that the PNG_MAX_MALLOC_64K test is enabled in this case, but this is a
- * potential breakage point if the types in pngconf.h aren't exactly right.
- */
- png_crc_read(png_ptr, buffer, length);
-
- if (png_crc_finish(png_ptr, skip))
- return;
-
- buffer[length] = 0;
-
- for (entry_start = buffer; *entry_start; entry_start++)
- /* Empty loop to find end of name */ ;
-
- ++entry_start;
-
- /* A sample depth should follow the separator, and we should be on it */
- if (entry_start > buffer + length - 2)
- {
- png_warning(png_ptr, "malformed sPLT chunk");
- return;
- }
-
- new_palette.depth = *entry_start++;
- entry_size = (new_palette.depth == 8 ? 6 : 10);
- /* This must fit in a png_uint_32 because it is derived from the original
- * chunk data length.
- */
- data_length = length - (png_uint_32)(entry_start - buffer);
-
- /* Integrity-check the data length */
- if (data_length % entry_size)
- {
- png_warning(png_ptr, "sPLT chunk has bad length");
- return;
- }
-
- dl = (png_int_32)(data_length / entry_size);
- max_dl = PNG_SIZE_MAX / (sizeof (png_sPLT_entry));
-
- if (dl > max_dl)
- {
- png_warning(png_ptr, "sPLT chunk too long");
- return;
- }
-
- new_palette.nentries = (png_int_32)(data_length / entry_size);
-
- new_palette.entries = (png_sPLT_entryp)png_malloc_warn(
- png_ptr, new_palette.nentries * (sizeof (png_sPLT_entry)));
-
- if (new_palette.entries == NULL)
- {
- png_warning(png_ptr, "sPLT chunk requires too much memory");
- return;
- }
-
-#ifdef PNG_POINTER_INDEXING_SUPPORTED
- for (i = 0; i < new_palette.nentries; i++)
- {
- pp = new_palette.entries + i;
-
- if (new_palette.depth == 8)
- {
- pp->red = *entry_start++;
- pp->green = *entry_start++;
- pp->blue = *entry_start++;
- pp->alpha = *entry_start++;
- }
-
- else
- {
- pp->red = png_get_uint_16(entry_start); entry_start += 2;
- pp->green = png_get_uint_16(entry_start); entry_start += 2;
- pp->blue = png_get_uint_16(entry_start); entry_start += 2;
- pp->alpha = png_get_uint_16(entry_start); entry_start += 2;
- }
-
- pp->frequency = png_get_uint_16(entry_start); entry_start += 2;
- }
-#else
- pp = new_palette.entries;
-
- for (i = 0; i < new_palette.nentries; i++)
- {
-
- if (new_palette.depth == 8)
- {
- pp[i].red = *entry_start++;
- pp[i].green = *entry_start++;
- pp[i].blue = *entry_start++;
- pp[i].alpha = *entry_start++;
- }
-
- else
- {
- pp[i].red = png_get_uint_16(entry_start); entry_start += 2;
- pp[i].green = png_get_uint_16(entry_start); entry_start += 2;
- pp[i].blue = png_get_uint_16(entry_start); entry_start += 2;
- pp[i].alpha = png_get_uint_16(entry_start); entry_start += 2;
- }
-
- pp[i].frequency = png_get_uint_16(entry_start); entry_start += 2;
- }
-#endif
-
- /* Discard all chunk data except the name and stash that */
- new_palette.name = (png_charp)buffer;
-
- png_set_sPLT(png_ptr, info_ptr, &new_palette, 1);
-
- png_free(png_ptr, new_palette.entries);
-}
-#endif /* PNG_READ_sPLT_SUPPORTED */
-
-#ifdef PNG_READ_tRNS_SUPPORTED
-void /* PRIVATE */
-png_handle_tRNS(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
-{
- png_byte readbuf[PNG_MAX_PALETTE_LENGTH];
-
- png_debug(1, "in png_handle_tRNS");
-
- if (!(png_ptr->mode & PNG_HAVE_IHDR))
- png_chunk_error(png_ptr, "missing IHDR");
-
- else if (png_ptr->mode & PNG_HAVE_IDAT)
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "out of place");
- return;
- }
-
- else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tRNS))
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "duplicate");
- return;
- }
-
- if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY)
- {
- png_byte buf[2];
-
- if (length != 2)
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "invalid");
- return;
- }
-
- png_crc_read(png_ptr, buf, 2);
- png_ptr->num_trans = 1;
- png_ptr->trans_color.gray = png_get_uint_16(buf);
- }
-
- else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB)
- {
- png_byte buf[6];
-
- if (length != 6)
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "invalid");
- return;
- }
-
- png_crc_read(png_ptr, buf, length);
- png_ptr->num_trans = 1;
- png_ptr->trans_color.red = png_get_uint_16(buf);
- png_ptr->trans_color.green = png_get_uint_16(buf + 2);
- png_ptr->trans_color.blue = png_get_uint_16(buf + 4);
- }
-
- else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
- {
- if (!(png_ptr->mode & PNG_HAVE_PLTE))
- {
- /* TODO: is this actually an error in the ISO spec? */
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "out of place");
- return;
- }
-
- if (length > png_ptr->num_palette || length > PNG_MAX_PALETTE_LENGTH ||
- length == 0)
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "invalid");
- return;
- }
-
- png_crc_read(png_ptr, readbuf, length);
- png_ptr->num_trans = (png_uint_16)length;
- }
-
- else
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "invalid with alpha channel");
- return;
- }
-
- if (png_crc_finish(png_ptr, 0))
- {
- png_ptr->num_trans = 0;
- return;
- }
-
- /* TODO: this is a horrible side effect in the palette case because the
- * png_struct ends up with a pointer to the tRNS buffer owned by the
- * png_info. Fix this.
- */
- png_set_tRNS(png_ptr, info_ptr, readbuf, png_ptr->num_trans,
- &(png_ptr->trans_color));
-}
-#endif
-
-#ifdef PNG_READ_bKGD_SUPPORTED
-void /* PRIVATE */
-png_handle_bKGD(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
-{
- unsigned int truelen;
- png_byte buf[6];
- png_color_16 background;
-
- png_debug(1, "in png_handle_bKGD");
-
- if (!(png_ptr->mode & PNG_HAVE_IHDR))
- png_chunk_error(png_ptr, "missing IHDR");
-
- else if ((png_ptr->mode & PNG_HAVE_IDAT) ||
- (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
- !(png_ptr->mode & PNG_HAVE_PLTE)))
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "out of place");
- return;
- }
-
- else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_bKGD))
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "duplicate");
- return;
- }
-
- if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
- truelen = 1;
-
- else if (png_ptr->color_type & PNG_COLOR_MASK_COLOR)
- truelen = 6;
-
- else
- truelen = 2;
-
- if (length != truelen)
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "invalid");
- return;
- }
-
- png_crc_read(png_ptr, buf, truelen);
-
- if (png_crc_finish(png_ptr, 0))
- return;
-
- /* We convert the index value into RGB components so that we can allow
- * arbitrary RGB values for background when we have transparency, and
- * so it is easy to determine the RGB values of the background color
- * from the info_ptr struct.
- */
- if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
- {
- background.index = buf[0];
-
- if (info_ptr && info_ptr->num_palette)
- {
- if (buf[0] >= info_ptr->num_palette)
- {
- png_chunk_benign_error(png_ptr, "invalid index");
- return;
- }
-
- background.red = (png_uint_16)png_ptr->palette[buf[0]].red;
- background.green = (png_uint_16)png_ptr->palette[buf[0]].green;
- background.blue = (png_uint_16)png_ptr->palette[buf[0]].blue;
- }
-
- else
- background.red = background.green = background.blue = 0;
-
- background.gray = 0;
- }
-
- else if (!(png_ptr->color_type & PNG_COLOR_MASK_COLOR)) /* GRAY */
- {
- background.index = 0;
- background.red =
- background.green =
- background.blue =
- background.gray = png_get_uint_16(buf);
- }
-
- else
- {
- background.index = 0;
- background.red = png_get_uint_16(buf);
- background.green = png_get_uint_16(buf + 2);
- background.blue = png_get_uint_16(buf + 4);
- background.gray = 0;
- }
-
- png_set_bKGD(png_ptr, info_ptr, &background);
-}
-#endif
-
-#ifdef PNG_READ_hIST_SUPPORTED
-void /* PRIVATE */
-png_handle_hIST(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
-{
- unsigned int num, i;
- png_uint_16 readbuf[PNG_MAX_PALETTE_LENGTH];
-
- png_debug(1, "in png_handle_hIST");
-
- if (!(png_ptr->mode & PNG_HAVE_IHDR))
- png_chunk_error(png_ptr, "missing IHDR");
-
- else if ((png_ptr->mode & PNG_HAVE_IDAT) || !(png_ptr->mode & PNG_HAVE_PLTE))
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "out of place");
- return;
- }
-
- else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_hIST))
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "duplicate");
- return;
- }
-
- num = length / 2 ;
-
- if (num != png_ptr->num_palette || num > PNG_MAX_PALETTE_LENGTH)
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "invalid");
- return;
- }
-
- for (i = 0; i < num; i++)
- {
- png_byte buf[2];
-
- png_crc_read(png_ptr, buf, 2);
- readbuf[i] = png_get_uint_16(buf);
- }
-
- if (png_crc_finish(png_ptr, 0))
- return;
-
- png_set_hIST(png_ptr, info_ptr, readbuf);
-}
-#endif
-
-#ifdef PNG_READ_pHYs_SUPPORTED
-void /* PRIVATE */
-png_handle_pHYs(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
-{
- png_byte buf[9];
- png_uint_32 res_x, res_y;
- int unit_type;
-
- png_debug(1, "in png_handle_pHYs");
-
- if (!(png_ptr->mode & PNG_HAVE_IHDR))
- png_chunk_error(png_ptr, "missing IHDR");
-
- else if (png_ptr->mode & PNG_HAVE_IDAT)
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "out of place");
- return;
- }
-
- else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs))
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "duplicate");
- return;
- }
-
- if (length != 9)
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "invalid");
- return;
- }
-
- png_crc_read(png_ptr, buf, 9);
-
- if (png_crc_finish(png_ptr, 0))
- return;
-
- res_x = png_get_uint_32(buf);
- res_y = png_get_uint_32(buf + 4);
- unit_type = buf[8];
- png_set_pHYs(png_ptr, info_ptr, res_x, res_y, unit_type);
-}
-#endif
-
-#ifdef PNG_READ_oFFs_SUPPORTED
-void /* PRIVATE */
-png_handle_oFFs(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
-{
- png_byte buf[9];
- png_int_32 offset_x, offset_y;
- int unit_type;
-
- png_debug(1, "in png_handle_oFFs");
-
- if (!(png_ptr->mode & PNG_HAVE_IHDR))
- png_chunk_error(png_ptr, "missing IHDR");
-
- else if (png_ptr->mode & PNG_HAVE_IDAT)
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "out of place");
- return;
- }
-
- else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs))
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "duplicate");
- return;
- }
-
- if (length != 9)
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "invalid");
- return;
- }
-
- png_crc_read(png_ptr, buf, 9);
-
- if (png_crc_finish(png_ptr, 0))
- return;
-
- offset_x = png_get_int_32(buf);
- offset_y = png_get_int_32(buf + 4);
- unit_type = buf[8];
- png_set_oFFs(png_ptr, info_ptr, offset_x, offset_y, unit_type);
-}
-#endif
-
-#ifdef PNG_READ_pCAL_SUPPORTED
-/* Read the pCAL chunk (described in the PNG Extensions document) */
-void /* PRIVATE */
-png_handle_pCAL(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
-{
- png_int_32 X0, X1;
- png_byte type, nparams;
- png_bytep buffer, buf, units, endptr;
- png_charpp params;
- int i;
-
- png_debug(1, "in png_handle_pCAL");
-
- if (!(png_ptr->mode & PNG_HAVE_IHDR))
- png_chunk_error(png_ptr, "missing IHDR");
-
- else if (png_ptr->mode & PNG_HAVE_IDAT)
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "out of place");
- return;
- }
-
- else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_pCAL))
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "duplicate");
- return;
- }
-
- png_debug1(2, "Allocating and reading pCAL chunk data (%u bytes)",
- length + 1);
-
- buffer = png_read_buffer(png_ptr, length+1, 2/*silent*/);
-
- if (buffer == NULL)
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "out of memory");
- return;
- }
-
- png_crc_read(png_ptr, buffer, length);
-
- if (png_crc_finish(png_ptr, 0))
- return;
-
- buffer[length] = 0; /* Null terminate the last string */
-
- png_debug(3, "Finding end of pCAL purpose string");
- for (buf = buffer; *buf; buf++)
- /* Empty loop */ ;
-
- endptr = buffer + length;
-
- /* We need to have at least 12 bytes after the purpose string
- * in order to get the parameter information.
- */
- if (endptr <= buf + 12)
- {
- png_chunk_benign_error(png_ptr, "invalid");
- return;
- }
-
- png_debug(3, "Reading pCAL X0, X1, type, nparams, and units");
- X0 = png_get_int_32((png_bytep)buf+1);
- X1 = png_get_int_32((png_bytep)buf+5);
- type = buf[9];
- nparams = buf[10];
- units = buf + 11;
-
- png_debug(3, "Checking pCAL equation type and number of parameters");
- /* Check that we have the right number of parameters for known
- * equation types.
- */
- if ((type == PNG_EQUATION_LINEAR && nparams != 2) ||
- (type == PNG_EQUATION_BASE_E && nparams != 3) ||
- (type == PNG_EQUATION_ARBITRARY && nparams != 3) ||
- (type == PNG_EQUATION_HYPERBOLIC && nparams != 4))
- {
- png_chunk_benign_error(png_ptr, "invalid parameter count");
- return;
- }
-
- else if (type >= PNG_EQUATION_LAST)
- {
- png_chunk_benign_error(png_ptr, "unrecognized equation type");
- }
-
- for (buf = units; *buf; buf++)
- /* Empty loop to move past the units string. */ ;
-
- png_debug(3, "Allocating pCAL parameters array");
-
- params = png_voidcast(png_charpp, png_malloc_warn(png_ptr,
- nparams * (sizeof (png_charp))));
-
- if (params == NULL)
- {
- png_chunk_benign_error(png_ptr, "out of memory");
- return;
- }
-
- /* Get pointers to the start of each parameter string. */
- for (i = 0; i < nparams; i++)
- {
- buf++; /* Skip the null string terminator from previous parameter. */
-
- png_debug1(3, "Reading pCAL parameter %d", i);
-
- for (params[i] = (png_charp)buf; buf <= endptr && *buf != 0; buf++)
- /* Empty loop to move past each parameter string */ ;
-
- /* Make sure we haven't run out of data yet */
- if (buf > endptr)
- {
- png_free(png_ptr, params);
- png_chunk_benign_error(png_ptr, "invalid data");
- return;
- }
- }
-
- png_set_pCAL(png_ptr, info_ptr, (png_charp)buffer, X0, X1, type, nparams,
- (png_charp)units, params);
-
- png_free(png_ptr, params);
-}
-#endif
-
-#ifdef PNG_READ_sCAL_SUPPORTED
-/* Read the sCAL chunk */
-void /* PRIVATE */
-png_handle_sCAL(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
-{
- png_bytep buffer;
- png_size_t i;
- int state;
-
- png_debug(1, "in png_handle_sCAL");
-
- if (!(png_ptr->mode & PNG_HAVE_IHDR))
- png_chunk_error(png_ptr, "missing IHDR");
-
- else if (png_ptr->mode & PNG_HAVE_IDAT)
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "out of place");
- return;
- }
-
- else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sCAL))
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "duplicate");
- return;
- }
-
- /* Need unit type, width, \0, height: minimum 4 bytes */
- else if (length < 4)
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "invalid");
- return;
- }
-
- png_debug1(2, "Allocating and reading sCAL chunk data (%u bytes)",
- length + 1);
-
- buffer = png_read_buffer(png_ptr, length+1, 2/*silent*/);
-
- if (buffer == NULL)
- {
- png_chunk_benign_error(png_ptr, "out of memory");
- png_crc_finish(png_ptr, length);
- return;
- }
-
- png_crc_read(png_ptr, buffer, length);
- buffer[length] = 0; /* Null terminate the last string */
-
- if (png_crc_finish(png_ptr, 0))
- return;
-
- /* Validate the unit. */
- if (buffer[0] != 1 && buffer[0] != 2)
- {
- png_chunk_benign_error(png_ptr, "invalid unit");
- return;
- }
-
- /* Validate the ASCII numbers, need two ASCII numbers separated by
- * a '\0' and they need to fit exactly in the chunk data.
- */
- i = 1;
- state = 0;
-
- if (!png_check_fp_number((png_const_charp)buffer, length, &state, &i) ||
- i >= length || buffer[i++] != 0)
- png_chunk_benign_error(png_ptr, "bad width format");
-
- else if (!PNG_FP_IS_POSITIVE(state))
- png_chunk_benign_error(png_ptr, "non-positive width");
-
- else
- {
- png_size_t heighti = i;
-
- state = 0;
- if (!png_check_fp_number((png_const_charp)buffer, length, &state, &i) ||
- i != length)
- png_chunk_benign_error(png_ptr, "bad height format");
-
- else if (!PNG_FP_IS_POSITIVE(state))
- png_chunk_benign_error(png_ptr, "non-positive height");
-
- else
- /* This is the (only) success case. */
- png_set_sCAL_s(png_ptr, info_ptr, buffer[0],
- (png_charp)buffer+1, (png_charp)buffer+heighti);
- }
-}
-#endif
-
-#ifdef PNG_READ_tIME_SUPPORTED
-void /* PRIVATE */
-png_handle_tIME(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
-{
- png_byte buf[7];
- png_time mod_time;
-
- png_debug(1, "in png_handle_tIME");
-
- if (!(png_ptr->mode & PNG_HAVE_IHDR))
- png_chunk_error(png_ptr, "missing IHDR");
-
- else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tIME))
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "duplicate");
- return;
- }
-
- if (png_ptr->mode & PNG_HAVE_IDAT)
- png_ptr->mode |= PNG_AFTER_IDAT;
-
- if (length != 7)
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "invalid");
- return;
- }
-
- png_crc_read(png_ptr, buf, 7);
-
- if (png_crc_finish(png_ptr, 0))
- return;
-
- mod_time.second = buf[6];
- mod_time.minute = buf[5];
- mod_time.hour = buf[4];
- mod_time.day = buf[3];
- mod_time.month = buf[2];
- mod_time.year = png_get_uint_16(buf);
-
- png_set_tIME(png_ptr, info_ptr, &mod_time);
-}
-#endif
-
-#ifdef PNG_READ_tEXt_SUPPORTED
-/* Note: this does not properly handle chunks that are > 64K under DOS */
-void /* PRIVATE */
-png_handle_tEXt(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
-{
- png_text text_info;
- png_bytep buffer;
- png_charp key;
- png_charp text;
- png_uint_32 skip = 0;
-
- png_debug(1, "in png_handle_tEXt");
-
-#ifdef PNG_USER_LIMITS_SUPPORTED
- if (png_ptr->user_chunk_cache_max != 0)
- {
- if (png_ptr->user_chunk_cache_max == 1)
- {
- png_crc_finish(png_ptr, length);
- return;
- }
-
- if (--png_ptr->user_chunk_cache_max == 1)
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "no space in chunk cache");
- return;
- }
- }
-#endif
-
- if (!(png_ptr->mode & PNG_HAVE_IHDR))
- png_chunk_error(png_ptr, "missing IHDR");
-
- if (png_ptr->mode & PNG_HAVE_IDAT)
- png_ptr->mode |= PNG_AFTER_IDAT;
-
-#ifdef PNG_MAX_MALLOC_64K
- if (length > 65535U)
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "too large to fit in memory");
- return;
- }
-#endif
-
- buffer = png_read_buffer(png_ptr, length+1, 1/*warn*/);
-
- if (buffer == NULL)
- {
- png_chunk_benign_error(png_ptr, "out of memory");
- return;
- }
-
- png_crc_read(png_ptr, buffer, length);
-
- if (png_crc_finish(png_ptr, skip))
- return;
-
- key = (png_charp)buffer;
- key[length] = 0;
-
- for (text = key; *text; text++)
- /* Empty loop to find end of key */ ;
-
- if (text != key + length)
- text++;
-
- text_info.compression = PNG_TEXT_COMPRESSION_NONE;
- text_info.key = key;
- text_info.lang = NULL;
- text_info.lang_key = NULL;
- text_info.itxt_length = 0;
- text_info.text = text;
- text_info.text_length = strlen(text);
-
- if (png_set_text_2(png_ptr, info_ptr, &text_info, 1))
- png_warning(png_ptr, "Insufficient memory to process text chunk");
-}
-#endif
-
-#ifdef PNG_READ_zTXt_SUPPORTED
-/* Note: this does not correctly handle chunks that are > 64K under DOS */
-void /* PRIVATE */
-png_handle_zTXt(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
-{
- png_const_charp errmsg = NULL;
- png_bytep buffer;
- png_uint_32 keyword_length;
-
- png_debug(1, "in png_handle_zTXt");
-
-#ifdef PNG_USER_LIMITS_SUPPORTED
- if (png_ptr->user_chunk_cache_max != 0)
- {
- if (png_ptr->user_chunk_cache_max == 1)
- {
- png_crc_finish(png_ptr, length);
- return;
- }
-
- if (--png_ptr->user_chunk_cache_max == 1)
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "no space in chunk cache");
- return;
- }
- }
-#endif
-
- if (!(png_ptr->mode & PNG_HAVE_IHDR))
- png_chunk_error(png_ptr, "missing IHDR");
-
- if (png_ptr->mode & PNG_HAVE_IDAT)
- png_ptr->mode |= PNG_AFTER_IDAT;
-
- buffer = png_read_buffer(png_ptr, length, 2/*silent*/);
-
- if (buffer == NULL)
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "out of memory");
- return;
- }
-
- png_crc_read(png_ptr, buffer, length);
-
- if (png_crc_finish(png_ptr, 0))
- return;
-
- /* TODO: also check that the keyword contents match the spec! */
- for (keyword_length = 0;
- keyword_length < length && buffer[keyword_length] != 0;
- ++keyword_length)
- /* Empty loop to find end of name */ ;
-
- if (keyword_length > 79 || keyword_length < 1)
- errmsg = "bad keyword";
-
- /* zTXt must have some LZ data after the keyword, although it may expand to
- * zero bytes; we need a '\0' at the end of the keyword, the compression type
- * then the LZ data:
- */
- else if (keyword_length + 3 > length)
- errmsg = "truncated";
-
- else if (buffer[keyword_length+1] != PNG_COMPRESSION_TYPE_BASE)
- errmsg = "unknown compression type";
-
- else
- {
- png_alloc_size_t uncompressed_length = PNG_SIZE_MAX;
-
- /* TODO: at present png_decompress_chunk imposes a single application
- * level memory limit, this should be split to different values for iCCP
- * and text chunks.
- */
- if (png_decompress_chunk(png_ptr, length, keyword_length+2,
- &uncompressed_length, 1/*terminate*/) == Z_STREAM_END)
- {
- png_text text;
-
- /* It worked; png_ptr->read_buffer now looks like a tEXt chunk except
- * for the extra compression type byte and the fact that it isn't
- * necessarily '\0' terminated.
- */
- buffer = png_ptr->read_buffer;
- buffer[uncompressed_length+(keyword_length+2)] = 0;
-
- text.compression = PNG_TEXT_COMPRESSION_zTXt;
- text.key = (png_charp)buffer;
- text.text = (png_charp)(buffer + keyword_length+2);
- text.text_length = uncompressed_length;
- text.itxt_length = 0;
- text.lang = NULL;
- text.lang_key = NULL;
-
- if (png_set_text_2(png_ptr, info_ptr, &text, 1))
- errmsg = "insufficient memory";
- }
-
- else
- errmsg = png_ptr->zstream.msg;
- }
-
- if (errmsg != NULL)
- png_chunk_benign_error(png_ptr, errmsg);
-}
-#endif
-
-#ifdef PNG_READ_iTXt_SUPPORTED
-/* Note: this does not correctly handle chunks that are > 64K under DOS */
-void /* PRIVATE */
-png_handle_iTXt(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
-{
- png_const_charp errmsg = NULL;
- png_bytep buffer;
- png_uint_32 prefix_length;
-
- png_debug(1, "in png_handle_iTXt");
-
-#ifdef PNG_USER_LIMITS_SUPPORTED
- if (png_ptr->user_chunk_cache_max != 0)
- {
- if (png_ptr->user_chunk_cache_max == 1)
- {
- png_crc_finish(png_ptr, length);
- return;
- }
-
- if (--png_ptr->user_chunk_cache_max == 1)
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "no space in chunk cache");
- return;
- }
- }
-#endif
-
- if (!(png_ptr->mode & PNG_HAVE_IHDR))
- png_chunk_error(png_ptr, "missing IHDR");
-
- if (png_ptr->mode & PNG_HAVE_IDAT)
- png_ptr->mode |= PNG_AFTER_IDAT;
-
- buffer = png_read_buffer(png_ptr, length+1, 1/*warn*/);
-
- if (buffer == NULL)
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "out of memory");
- return;
- }
-
- png_crc_read(png_ptr, buffer, length);
-
- if (png_crc_finish(png_ptr, 0))
- return;
-
- /* First the keyword. */
- for (prefix_length=0;
- prefix_length < length && buffer[prefix_length] != 0;
- ++prefix_length)
- /* Empty loop */ ;
-
- /* Perform a basic check on the keyword length here. */
- if (prefix_length > 79 || prefix_length < 1)
- errmsg = "bad keyword";
-
- /* Expect keyword, compression flag, compression type, language, translated
- * keyword (both may be empty but are 0 terminated) then the text, which may
- * be empty.
- */
- else if (prefix_length + 5 > length)
- errmsg = "truncated";
-
- else if (buffer[prefix_length+1] == 0 ||
- (buffer[prefix_length+1] == 1 &&
- buffer[prefix_length+2] == PNG_COMPRESSION_TYPE_BASE))
- {
- int compressed = buffer[prefix_length+1] != 0;
- png_uint_32 language_offset, translated_keyword_offset;
- png_alloc_size_t uncompressed_length = 0;
-
- /* Now the language tag */
- prefix_length += 3;
- language_offset = prefix_length;
-
- for (; prefix_length < length && buffer[prefix_length] != 0;
- ++prefix_length)
- /* Empty loop */ ;
-
- /* WARNING: the length may be invalid here, this is checked below. */
- translated_keyword_offset = ++prefix_length;
-
- for (; prefix_length < length && buffer[prefix_length] != 0;
- ++prefix_length)
- /* Empty loop */ ;
-
- /* prefix_length should now be at the trailing '\0' of the translated
- * keyword, but it may already be over the end. None of this arithmetic
- * can overflow because chunks are at most 2^31 bytes long, but on 16-bit
- * systems the available allocaton may overflow.
- */
- ++prefix_length;
-
- if (!compressed && prefix_length <= length)
- uncompressed_length = length - prefix_length;
-
- else if (compressed && prefix_length < length)
- {
- uncompressed_length = PNG_SIZE_MAX;
-
- /* TODO: at present png_decompress_chunk imposes a single application
- * level memory limit, this should be split to different values for
- * iCCP and text chunks.
- */
- if (png_decompress_chunk(png_ptr, length, prefix_length,
- &uncompressed_length, 1/*terminate*/) == Z_STREAM_END)
- buffer = png_ptr->read_buffer;
-
- else
- errmsg = png_ptr->zstream.msg;
- }
-
- else
- errmsg = "truncated";
-
- if (errmsg == NULL)
- {
- png_text text;
-
- buffer[uncompressed_length+prefix_length] = 0;
-
- if (compressed)
- text.compression = PNG_ITXT_COMPRESSION_NONE;
-
- else
- text.compression = PNG_ITXT_COMPRESSION_zTXt;
-
- text.key = (png_charp)buffer;
- text.lang = (png_charp)buffer + language_offset;
- text.lang_key = (png_charp)buffer + translated_keyword_offset;
- text.text = (png_charp)buffer + prefix_length;
- text.text_length = 0;
- text.itxt_length = uncompressed_length;
-
- if (png_set_text_2(png_ptr, info_ptr, &text, 1))
- errmsg = "insufficient memory";
- }
- }
-
- else
- errmsg = "bad compression info";
-
- if (errmsg != NULL)
- png_chunk_benign_error(png_ptr, errmsg);
-}
-#endif
-
-#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
-/* Utility function for png_handle_unknown; set up png_ptr::unknown_chunk */
-static int
-png_cache_unknown_chunk(png_structrp png_ptr, png_uint_32 length)
-{
- png_alloc_size_t limit = PNG_SIZE_MAX;
-
- if (png_ptr->unknown_chunk.data != NULL)
- {
- png_free(png_ptr, png_ptr->unknown_chunk.data);
- png_ptr->unknown_chunk.data = NULL;
- }
-
-# ifdef PNG_SET_CHUNK_MALLOC_LIMIT_SUPPORTED
- if (png_ptr->user_chunk_malloc_max > 0 &&
- png_ptr->user_chunk_malloc_max < limit)
- limit = png_ptr->user_chunk_malloc_max;
-
-# elif PNG_USER_CHUNK_MALLOC_MAX > 0
- if (PNG_USER_CHUNK_MALLOC_MAX < limit)
- limit = PNG_USER_CHUNK_MALLOC_MAX;
-# endif
-
- if (length <= limit)
- {
- PNG_CSTRING_FROM_CHUNK(png_ptr->unknown_chunk.name, png_ptr->chunk_name);
- /* The following is safe because of the PNG_SIZE_MAX init above */
- png_ptr->unknown_chunk.size = (png_size_t)length/*SAFE*/;
- /* 'mode' is a flag array, only the bottom four bits matter here */
- png_ptr->unknown_chunk.location = (png_byte)png_ptr->mode/*SAFE*/;
-
- if (length == 0)
- png_ptr->unknown_chunk.data = NULL;
-
- else
- {
- /* Do a 'warn' here - it is handled below. */
- png_ptr->unknown_chunk.data = png_voidcast(png_bytep,
- png_malloc_warn(png_ptr, length));
- }
- }
-
- if (png_ptr->unknown_chunk.data == NULL && length > 0)
- {
- /* This is benign because we clean up correctly */
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "unknown chunk exceeds memory limits");
- return 0;
- }
-
- else
- {
- if (length > 0)
- png_crc_read(png_ptr, png_ptr->unknown_chunk.data, length);
- png_crc_finish(png_ptr, 0);
- return 1;
- }
-}
-#endif /* PNG_READ_UNKNOWN_CHUNKS_SUPPORTED */
-
-/* Handle an unknown, or known but disabled, chunk */
-void /* PRIVATE */
-png_handle_unknown(png_structrp png_ptr, png_inforp info_ptr,
- png_uint_32 length, int keep)
-{
- int handled = 0; /* the chunk was handled */
-
- png_debug(1, "in png_handle_unknown");
-
-#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
- /* NOTE: this code is based on the code in libpng-1.4.12 except for fixing
- * the bug which meant that setting a non-default behavior for a specific
- * chunk would be ignored (the default was always used unless a user
- * callback was installed).
- *
- * 'keep' is the value from the png_chunk_unknown_handling, the setting for
- * this specific chunk_name, if PNG_HANDLE_AS_UNKNOWN_SUPPORTED, if not it
- * will always be PNG_HANDLE_CHUNK_AS_DEFAULT and it needs to be set here.
- * This is just an optimization to avoid multiple calls to the lookup
- * function.
- */
-# ifndef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
-# ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
- keep = png_chunk_unknown_handling(png_ptr, png_ptr->chunk_name);
-# endif
-# endif
-
- /* One of the following methods will read the chunk or skip it (at least one
- * of these is always defined because this is the only way to switch on
- * PNG_READ_UNKNOWN_CHUNKS_SUPPORTED)
- */
-# ifdef PNG_READ_USER_CHUNKS_SUPPORTED
- /* The user callback takes precedence over the chunk keep value, but the
- * keep value is still required to validate a save of a critical chunk.
- */
- if (png_ptr->read_user_chunk_fn != NULL)
- {
- if (png_cache_unknown_chunk(png_ptr, length))
- {
- /* Callback to user unknown chunk handler */
- int ret = (*(png_ptr->read_user_chunk_fn))(png_ptr,
- &png_ptr->unknown_chunk);
-
- /* ret is:
- * negative: An error occured, png_chunk_error will be called.
- * zero: The chunk was not handled, the chunk will be discarded
- * unless png_set_keep_unknown_chunks has been used to set
- * a 'keep' behavior for this particular chunk, in which
- * case that will be used. A critical chunk will cause an
- * error at this point unless it is to be saved.
- * positive: The chunk was handled, libpng will ignore/discard it.
- */
- if (ret < 0)
- png_chunk_error(png_ptr, "error in user chunk");
-
- else if (ret == 0)
- {
- /* If the keep value is 'default' or 'never' override it, but
- * still error out on critical chunks unless the keep value is
- * 'always' While this is weird it is the behavior in 1.4.12.
- * A possible improvement would be to obey the value set for the
- * chunk, but this would be an API change that would probably
- * damage some applications.
- *
- * The png_app_warning below catches the case that matters, where
- * the application has not set specific save or ignore for this
- * chunk or global save or ignore.
- */
- if (keep < PNG_HANDLE_CHUNK_IF_SAFE)
- {
-# ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
- if (png_ptr->unknown_default < PNG_HANDLE_CHUNK_IF_SAFE)
- {
- png_chunk_warning(png_ptr, "Saving unknown chunk:");
- png_app_warning(png_ptr,
- "forcing save of an unhandled chunk;"
- " please call png_set_keep_unknown_chunks");
- /* with keep = PNG_HANDLE_CHUNK_IF_SAFE */
- }
-# endif
- keep = PNG_HANDLE_CHUNK_IF_SAFE;
- }
- }
-
- else /* chunk was handled */
- {
- handled = 1;
- /* Critical chunks can be safely discarded at this point. */
- keep = PNG_HANDLE_CHUNK_NEVER;
- }
- }
-
- else
- keep = PNG_HANDLE_CHUNK_NEVER; /* insufficient memory */
- }
-
- else
- /* Use the SAVE_UNKNOWN_CHUNKS code or skip the chunk */
-# endif /* PNG_READ_USER_CHUNKS_SUPPORTED */
-
-# ifdef PNG_SAVE_UNKNOWN_CHUNKS_SUPPORTED
- {
- /* keep is currently just the per-chunk setting, if there was no
- * setting change it to the global default now (not that this may
- * still be AS_DEFAULT) then obtain the cache of the chunk if required,
- * if not simply skip the chunk.
- */
- if (keep == PNG_HANDLE_CHUNK_AS_DEFAULT)
- keep = png_ptr->unknown_default;
-
- if (keep == PNG_HANDLE_CHUNK_ALWAYS ||
- (keep == PNG_HANDLE_CHUNK_IF_SAFE &&
- PNG_CHUNK_ANCILLARY(png_ptr->chunk_name)))
- {
- if (!png_cache_unknown_chunk(png_ptr, length))
- keep = PNG_HANDLE_CHUNK_NEVER;
- }
-
- else
- png_crc_finish(png_ptr, length);
- }
-# else
-# ifndef PNG_READ_USER_CHUNKS_SUPPORTED
-# error no method to support READ_UNKNOWN_CHUNKS
-# endif
-
- {
- /* If here there is no read callback pointer set and no support is
- * compiled in to just save the unknown chunks, so simply skip this
- * chunk. If 'keep' is something other than AS_DEFAULT or NEVER then
- * the app has erroneously asked for unknown chunk saving when there
- * is no support.
- */
- if (keep > PNG_HANDLE_CHUNK_NEVER)
- png_app_error(png_ptr, "no unknown chunk support available");
-
- png_crc_finish(png_ptr, length);
- }
-# endif
-
-# ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
- /* Now store the chunk in the chunk list if appropriate, and if the limits
- * permit it.
- */
- if (keep == PNG_HANDLE_CHUNK_ALWAYS ||
- (keep == PNG_HANDLE_CHUNK_IF_SAFE &&
- PNG_CHUNK_ANCILLARY(png_ptr->chunk_name)))
- {
-# ifdef PNG_USER_LIMITS_SUPPORTED
- switch (png_ptr->user_chunk_cache_max)
- {
- case 2:
- png_ptr->user_chunk_cache_max = 1;
- png_chunk_benign_error(png_ptr, "no space in chunk cache");
- /* FALL THROUGH */
- case 1:
- /* NOTE: prior to 1.6.0 this case resulted in an unknown critical
- * chunk being skipped, now there will be a hard error below.
- */
- break;
-
- default: /* not at limit */
- --(png_ptr->user_chunk_cache_max);
- /* FALL THROUGH */
- case 0: /* no limit */
-# endif /* PNG_USER_LIMITS_SUPPORTED */
- /* Here when the limit isn't reached or when limits are compiled
- * out; store the chunk.
- */
- png_set_unknown_chunks(png_ptr, info_ptr,
- &png_ptr->unknown_chunk, 1);
- handled = 1;
-# ifdef PNG_USER_LIMITS_SUPPORTED
- break;
- }
-# endif
- }
-# else /* no store support! */
- PNG_UNUSED(info_ptr)
-# error untested code (reading unknown chunks with no store support)
-# endif
-
- /* Regardless of the error handling below the cached data (if any) can be
- * freed now. Notice that the data is not freed if there is a png_error, but
- * it will be freed by destroy_read_struct.
- */
- if (png_ptr->unknown_chunk.data != NULL)
- png_free(png_ptr, png_ptr->unknown_chunk.data);
- png_ptr->unknown_chunk.data = NULL;
-
-#else /* !PNG_READ_UNKNOWN_CHUNKS_SUPPORTED */
- /* There is no support to read an unknown chunk, so just skip it. */
- png_crc_finish(png_ptr, length);
- PNG_UNUSED(info_ptr)
- PNG_UNUSED(keep)
-#endif /* !PNG_READ_UNKNOWN_CHUNKS_SUPPORTED */
-
- /* Check for unhandled critical chunks */
- if (!handled && PNG_CHUNK_CRITICAL(png_ptr->chunk_name))
- png_chunk_error(png_ptr, "unhandled critical chunk");
-}
-
-/* This function is called to verify that a chunk name is valid.
- * This function can't have the "critical chunk check" incorporated
- * into it, since in the future we will need to be able to call user
- * functions to handle unknown critical chunks after we check that
- * the chunk name itself is valid.
- */
-
-/* Bit hacking: the test for an invalid byte in the 4 byte chunk name is:
- *
- * ((c) < 65 || (c) > 122 || ((c) > 90 && (c) < 97))
- */
-
-void /* PRIVATE */
-png_check_chunk_name(png_structrp png_ptr, png_uint_32 chunk_name)
-{
- int i;
-
- png_debug(1, "in png_check_chunk_name");
-
- for (i=1; i<=4; ++i)
- {
- int c = chunk_name & 0xff;
-
- if (c < 65 || c > 122 || (c > 90 && c < 97))
- png_chunk_error(png_ptr, "invalid chunk type");
-
- chunk_name >>= 8;
- }
-}
-
-/* Combines the row recently read in with the existing pixels in the row. This
- * routine takes care of alpha and transparency if requested. This routine also
- * handles the two methods of progressive display of interlaced images,
- * depending on the 'display' value; if 'display' is true then the whole row
- * (dp) is filled from the start by replicating the available pixels. If
- * 'display' is false only those pixels present in the pass are filled in.
- */
-void /* PRIVATE */
-png_combine_row(png_const_structrp png_ptr, png_bytep dp, int display)
-{
- unsigned int pixel_depth = png_ptr->transformed_pixel_depth;
- png_const_bytep sp = png_ptr->row_buf + 1;
- png_uint_32 row_width = png_ptr->width;
- unsigned int pass = png_ptr->pass;
- png_bytep end_ptr = 0;
- png_byte end_byte = 0;
- unsigned int end_mask;
-
- png_debug(1, "in png_combine_row");
-
- /* Added in 1.5.6: it should not be possible to enter this routine until at
- * least one row has been read from the PNG data and transformed.
- */
- if (pixel_depth == 0)
- png_error(png_ptr, "internal row logic error");
-
- /* Added in 1.5.4: the pixel depth should match the information returned by
- * any call to png_read_update_info at this point. Do not continue if we got
- * this wrong.
- */
- if (png_ptr->info_rowbytes != 0 && png_ptr->info_rowbytes !=
- PNG_ROWBYTES(pixel_depth, row_width))
- png_error(png_ptr, "internal row size calculation error");
-
- /* Don't expect this to ever happen: */
- if (row_width == 0)
- png_error(png_ptr, "internal row width error");
-
- /* Preserve the last byte in cases where only part of it will be overwritten,
- * the multiply below may overflow, we don't care because ANSI-C guarantees
- * we get the low bits.
- */
- end_mask = (pixel_depth * row_width) & 7;
- if (end_mask != 0)
- {
- /* end_ptr == NULL is a flag to say do nothing */
- end_ptr = dp + PNG_ROWBYTES(pixel_depth, row_width) - 1;
- end_byte = *end_ptr;
-# ifdef PNG_READ_PACKSWAP_SUPPORTED
- if (png_ptr->transformations & PNG_PACKSWAP) /* little-endian byte */
- end_mask = 0xff << end_mask;
-
- else /* big-endian byte */
-# endif
- end_mask = 0xff >> end_mask;
- /* end_mask is now the bits to *keep* from the destination row */
- }
-
- /* For non-interlaced images this reduces to a memcpy(). A memcpy()
- * will also happen if interlacing isn't supported or if the application
- * does not call png_set_interlace_handling(). In the latter cases the
- * caller just gets a sequence of the unexpanded rows from each interlace
- * pass.
- */
-#ifdef PNG_READ_INTERLACING_SUPPORTED
- if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE) &&
- pass < 6 && (display == 0 ||
- /* The following copies everything for 'display' on passes 0, 2 and 4. */
- (display == 1 && (pass & 1) != 0)))
- {
- /* Narrow images may have no bits in a pass; the caller should handle
- * this, but this test is cheap:
- */
- if (row_width <= PNG_PASS_START_COL(pass))
- return;
-
- if (pixel_depth < 8)
- {
- /* For pixel depths up to 4 bpp the 8-pixel mask can be expanded to fit
- * into 32 bits, then a single loop over the bytes using the four byte
- * values in the 32-bit mask can be used. For the 'display' option the
- * expanded mask may also not require any masking within a byte. To
- * make this work the PACKSWAP option must be taken into account - it
- * simply requires the pixels to be reversed in each byte.
- *
- * The 'regular' case requires a mask for each of the first 6 passes,
- * the 'display' case does a copy for the even passes in the range
- * 0..6. This has already been handled in the test above.
- *
- * The masks are arranged as four bytes with the first byte to use in
- * the lowest bits (little-endian) regardless of the order (PACKSWAP or
- * not) of the pixels in each byte.
- *
- * NOTE: the whole of this logic depends on the caller of this function
- * only calling it on rows appropriate to the pass. This function only
- * understands the 'x' logic; the 'y' logic is handled by the caller.
- *
- * The following defines allow generation of compile time constant bit
- * masks for each pixel depth and each possibility of swapped or not
- * swapped bytes. Pass 'p' is in the range 0..6; 'x', a pixel index,
- * is in the range 0..7; and the result is 1 if the pixel is to be
- * copied in the pass, 0 if not. 'S' is for the sparkle method, 'B'
- * for the block method.
- *
- * With some compilers a compile time expression of the general form:
- *
- * (shift >= 32) ? (a >> (shift-32)) : (b >> shift)
- *
- * Produces warnings with values of 'shift' in the range 33 to 63
- * because the right hand side of the ?: expression is evaluated by
- * the compiler even though it isn't used. Microsoft Visual C (various
- * versions) and the Intel C compiler are known to do this. To avoid
- * this the following macros are used in 1.5.6. This is a temporary
- * solution to avoid destabilizing the code during the release process.
- */
-# if PNG_USE_COMPILE_TIME_MASKS
-# define PNG_LSR(x,s) ((x)>>((s) & 0x1f))
-# define PNG_LSL(x,s) ((x)<<((s) & 0x1f))
-# else
-# define PNG_LSR(x,s) ((x)>>(s))
-# define PNG_LSL(x,s) ((x)<<(s))
-# endif
-# define S_COPY(p,x) (((p)<4 ? PNG_LSR(0x80088822,(3-(p))*8+(7-(x))) :\
- PNG_LSR(0xaa55ff00,(7-(p))*8+(7-(x)))) & 1)
-# define B_COPY(p,x) (((p)<4 ? PNG_LSR(0xff0fff33,(3-(p))*8+(7-(x))) :\
- PNG_LSR(0xff55ff00,(7-(p))*8+(7-(x)))) & 1)
-
- /* Return a mask for pass 'p' pixel 'x' at depth 'd'. The mask is
- * little endian - the first pixel is at bit 0 - however the extra
- * parameter 's' can be set to cause the mask position to be swapped
- * within each byte, to match the PNG format. This is done by XOR of
- * the shift with 7, 6 or 4 for bit depths 1, 2 and 4.
- */
-# define PIXEL_MASK(p,x,d,s) \
- (PNG_LSL(((PNG_LSL(1U,(d)))-1),(((x)*(d))^((s)?8-(d):0))))
-
- /* Hence generate the appropriate 'block' or 'sparkle' pixel copy mask.
- */
-# define S_MASKx(p,x,d,s) (S_COPY(p,x)?PIXEL_MASK(p,x,d,s):0)
-# define B_MASKx(p,x,d,s) (B_COPY(p,x)?PIXEL_MASK(p,x,d,s):0)
-
- /* Combine 8 of these to get the full mask. For the 1-bpp and 2-bpp
- * cases the result needs replicating, for the 4-bpp case the above
- * generates a full 32 bits.
- */
-# define MASK_EXPAND(m,d) ((m)*((d)==1?0x01010101:((d)==2?0x00010001:1)))
-
-# define S_MASK(p,d,s) MASK_EXPAND(S_MASKx(p,0,d,s) + S_MASKx(p,1,d,s) +\
- S_MASKx(p,2,d,s) + S_MASKx(p,3,d,s) + S_MASKx(p,4,d,s) +\
- S_MASKx(p,5,d,s) + S_MASKx(p,6,d,s) + S_MASKx(p,7,d,s), d)
-
-# define B_MASK(p,d,s) MASK_EXPAND(B_MASKx(p,0,d,s) + B_MASKx(p,1,d,s) +\
- B_MASKx(p,2,d,s) + B_MASKx(p,3,d,s) + B_MASKx(p,4,d,s) +\
- B_MASKx(p,5,d,s) + B_MASKx(p,6,d,s) + B_MASKx(p,7,d,s), d)
-
-#if PNG_USE_COMPILE_TIME_MASKS
- /* Utility macros to construct all the masks for a depth/swap
- * combination. The 's' parameter says whether the format is PNG
- * (big endian bytes) or not. Only the three odd-numbered passes are
- * required for the display/block algorithm.
- */
-# define S_MASKS(d,s) { S_MASK(0,d,s), S_MASK(1,d,s), S_MASK(2,d,s),\
- S_MASK(3,d,s), S_MASK(4,d,s), S_MASK(5,d,s) }
-
-# define B_MASKS(d,s) { B_MASK(1,d,s), S_MASK(3,d,s), S_MASK(5,d,s) }
-
-# define DEPTH_INDEX(d) ((d)==1?0:((d)==2?1:2))
-
- /* Hence the pre-compiled masks indexed by PACKSWAP (or not), depth and
- * then pass:
- */
- static PNG_CONST png_uint_32 row_mask[2/*PACKSWAP*/][3/*depth*/][6] =
- {
- /* Little-endian byte masks for PACKSWAP */
- { S_MASKS(1,0), S_MASKS(2,0), S_MASKS(4,0) },
- /* Normal (big-endian byte) masks - PNG format */
- { S_MASKS(1,1), S_MASKS(2,1), S_MASKS(4,1) }
- };
-
- /* display_mask has only three entries for the odd passes, so index by
- * pass>>1.
- */
- static PNG_CONST png_uint_32 display_mask[2][3][3] =
- {
- /* Little-endian byte masks for PACKSWAP */
- { B_MASKS(1,0), B_MASKS(2,0), B_MASKS(4,0) },
- /* Normal (big-endian byte) masks - PNG format */
- { B_MASKS(1,1), B_MASKS(2,1), B_MASKS(4,1) }
- };
-
-# define MASK(pass,depth,display,png)\
- ((display)?display_mask[png][DEPTH_INDEX(depth)][pass>>1]:\
- row_mask[png][DEPTH_INDEX(depth)][pass])
-
-#else /* !PNG_USE_COMPILE_TIME_MASKS */
- /* This is the runtime alternative: it seems unlikely that this will
- * ever be either smaller or faster than the compile time approach.
- */
-# define MASK(pass,depth,display,png)\
- ((display)?B_MASK(pass,depth,png):S_MASK(pass,depth,png))
-#endif /* !PNG_USE_COMPILE_TIME_MASKS */
-
- /* Use the appropriate mask to copy the required bits. In some cases
- * the byte mask will be 0 or 0xff, optimize these cases. row_width is
- * the number of pixels, but the code copies bytes, so it is necessary
- * to special case the end.
- */
- png_uint_32 pixels_per_byte = 8 / pixel_depth;
- png_uint_32 mask;
-
-# ifdef PNG_READ_PACKSWAP_SUPPORTED
- if (png_ptr->transformations & PNG_PACKSWAP)
- mask = MASK(pass, pixel_depth, display, 0);
-
- else
-# endif
- mask = MASK(pass, pixel_depth, display, 1);
-
- for (;;)
- {
- png_uint_32 m;
-
- /* It doesn't matter in the following if png_uint_32 has more than
- * 32 bits because the high bits always match those in m<<24; it is,
- * however, essential to use OR here, not +, because of this.
- */
- m = mask;
- mask = (m >> 8) | (m << 24); /* rotate right to good compilers */
- m &= 0xff;
-
- if (m != 0) /* something to copy */
- {
- if (m != 0xff)
- *dp = (png_byte)((*dp & ~m) | (*sp & m));
- else
- *dp = *sp;
- }
-
- /* NOTE: this may overwrite the last byte with garbage if the image
- * is not an exact number of bytes wide; libpng has always done
- * this.
- */
- if (row_width <= pixels_per_byte)
- break; /* May need to restore part of the last byte */
-
- row_width -= pixels_per_byte;
- ++dp;
- ++sp;
- }
- }
-
- else /* pixel_depth >= 8 */
- {
- unsigned int bytes_to_copy, bytes_to_jump;
-
- /* Validate the depth - it must be a multiple of 8 */
- if (pixel_depth & 7)
- png_error(png_ptr, "invalid user transform pixel depth");
-
- pixel_depth >>= 3; /* now in bytes */
- row_width *= pixel_depth;
-
- /* Regardless of pass number the Adam 7 interlace always results in a
- * fixed number of pixels to copy then to skip. There may be a
- * different number of pixels to skip at the start though.
- */
- {
- unsigned int offset = PNG_PASS_START_COL(pass) * pixel_depth;
-
- row_width -= offset;
- dp += offset;
- sp += offset;
- }
-
- /* Work out the bytes to copy. */
- if (display)
- {
- /* When doing the 'block' algorithm the pixel in the pass gets
- * replicated to adjacent pixels. This is why the even (0,2,4,6)
- * passes are skipped above - the entire expanded row is copied.
- */
- bytes_to_copy = (1<<((6-pass)>>1)) * pixel_depth;
-
- /* But don't allow this number to exceed the actual row width. */
- if (bytes_to_copy > row_width)
- bytes_to_copy = row_width;
- }
-
- else /* normal row; Adam7 only ever gives us one pixel to copy. */
- bytes_to_copy = pixel_depth;
-
- /* In Adam7 there is a constant offset between where the pixels go. */
- bytes_to_jump = PNG_PASS_COL_OFFSET(pass) * pixel_depth;
-
- /* And simply copy these bytes. Some optimization is possible here,
- * depending on the value of 'bytes_to_copy'. Special case the low
- * byte counts, which we know to be frequent.
- *
- * Notice that these cases all 'return' rather than 'break' - this
- * avoids an unnecessary test on whether to restore the last byte
- * below.
- */
- switch (bytes_to_copy)
- {
- case 1:
- for (;;)
- {
- *dp = *sp;
-
- if (row_width <= bytes_to_jump)
- return;
-
- dp += bytes_to_jump;
- sp += bytes_to_jump;
- row_width -= bytes_to_jump;
- }
-
- case 2:
- /* There is a possibility of a partial copy at the end here; this
- * slows the code down somewhat.
- */
- do
- {
- dp[0] = sp[0], dp[1] = sp[1];
-
- if (row_width <= bytes_to_jump)
- return;
-
- sp += bytes_to_jump;
- dp += bytes_to_jump;
- row_width -= bytes_to_jump;
- }
- while (row_width > 1);
-
- /* And there can only be one byte left at this point: */
- *dp = *sp;
- return;
-
- case 3:
- /* This can only be the RGB case, so each copy is exactly one
- * pixel and it is not necessary to check for a partial copy.
- */
- for(;;)
- {
- dp[0] = sp[0], dp[1] = sp[1], dp[2] = sp[2];
-
- if (row_width <= bytes_to_jump)
- return;
-
- sp += bytes_to_jump;
- dp += bytes_to_jump;
- row_width -= bytes_to_jump;
- }
-
- default:
-#if PNG_ALIGN_TYPE != PNG_ALIGN_NONE
- /* Check for double byte alignment and, if possible, use a
- * 16-bit copy. Don't attempt this for narrow images - ones that
- * are less than an interlace panel wide. Don't attempt it for
- * wide bytes_to_copy either - use the memcpy there.
- */
- if (bytes_to_copy < 16 /*else use memcpy*/ &&
- png_isaligned(dp, png_uint_16) &&
- png_isaligned(sp, png_uint_16) &&
- bytes_to_copy % (sizeof (png_uint_16)) == 0 &&
- bytes_to_jump % (sizeof (png_uint_16)) == 0)
- {
- /* Everything is aligned for png_uint_16 copies, but try for
- * png_uint_32 first.
- */
- if (png_isaligned(dp, png_uint_32) &&
- png_isaligned(sp, png_uint_32) &&
- bytes_to_copy % (sizeof (png_uint_32)) == 0 &&
- bytes_to_jump % (sizeof (png_uint_32)) == 0)
- {
- png_uint_32p dp32 = png_aligncast(png_uint_32p,dp);
- png_const_uint_32p sp32 = png_aligncastconst(
- png_const_uint_32p, sp);
- size_t skip = (bytes_to_jump-bytes_to_copy) /
- (sizeof (png_uint_32));
-
- do
- {
- size_t c = bytes_to_copy;
- do
- {
- *dp32++ = *sp32++;
- c -= (sizeof (png_uint_32));
- }
- while (c > 0);
-
- if (row_width <= bytes_to_jump)
- return;
-
- dp32 += skip;
- sp32 += skip;
- row_width -= bytes_to_jump;
- }
- while (bytes_to_copy <= row_width);
-
- /* Get to here when the row_width truncates the final copy.
- * There will be 1-3 bytes left to copy, so don't try the
- * 16-bit loop below.
- */
- dp = (png_bytep)dp32;
- sp = (png_const_bytep)sp32;
- do
- *dp++ = *sp++;
- while (--row_width > 0);
- return;
- }
-
- /* Else do it in 16-bit quantities, but only if the size is
- * not too large.
- */
- else
- {
- png_uint_16p dp16 = png_aligncast(png_uint_16p, dp);
- png_const_uint_16p sp16 = png_aligncastconst(
- png_const_uint_16p, sp);
- size_t skip = (bytes_to_jump-bytes_to_copy) /
- (sizeof (png_uint_16));
-
- do
- {
- size_t c = bytes_to_copy;
- do
- {
- *dp16++ = *sp16++;
- c -= (sizeof (png_uint_16));
- }
- while (c > 0);
-
- if (row_width <= bytes_to_jump)
- return;
-
- dp16 += skip;
- sp16 += skip;
- row_width -= bytes_to_jump;
- }
- while (bytes_to_copy <= row_width);
-
- /* End of row - 1 byte left, bytes_to_copy > row_width: */
- dp = (png_bytep)dp16;
- sp = (png_const_bytep)sp16;
- do
- *dp++ = *sp++;
- while (--row_width > 0);
- return;
- }
- }
-#endif /* PNG_ALIGN_ code */
-
- /* The true default - use a memcpy: */
- for (;;)
- {
- memcpy(dp, sp, bytes_to_copy);
-
- if (row_width <= bytes_to_jump)
- return;
-
- sp += bytes_to_jump;
- dp += bytes_to_jump;
- row_width -= bytes_to_jump;
- if (bytes_to_copy > row_width)
- bytes_to_copy = row_width;
- }
- }
-
- /* NOT REACHED*/
- } /* pixel_depth >= 8 */
-
- /* Here if pixel_depth < 8 to check 'end_ptr' below. */
- }
- else
-#endif
-
- /* If here then the switch above wasn't used so just memcpy the whole row
- * from the temporary row buffer (notice that this overwrites the end of the
- * destination row if it is a partial byte.)
- */
- memcpy(dp, sp, PNG_ROWBYTES(pixel_depth, row_width));
-
- /* Restore the overwritten bits from the last byte if necessary. */
- if (end_ptr != NULL)
- *end_ptr = (png_byte)((end_byte & end_mask) | (*end_ptr & ~end_mask));
-}
-
-#ifdef PNG_READ_INTERLACING_SUPPORTED
-void /* PRIVATE */
-png_do_read_interlace(png_row_infop row_info, png_bytep row, int pass,
- png_uint_32 transformations /* Because these may affect the byte layout */)
-{
- /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
- /* Offset to next interlace block */
- static PNG_CONST int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
-
- png_debug(1, "in png_do_read_interlace");
- if (row != NULL && row_info != NULL)
- {
- png_uint_32 final_width;
-
- final_width = row_info->width * png_pass_inc[pass];
-
- switch (row_info->pixel_depth)
- {
- case 1:
- {
- png_bytep sp = row + (png_size_t)((row_info->width - 1) >> 3);
- png_bytep dp = row + (png_size_t)((final_width - 1) >> 3);
- int sshift, dshift;
- int s_start, s_end, s_inc;
- int jstop = png_pass_inc[pass];
- png_byte v;
- png_uint_32 i;
- int j;
-
-#ifdef PNG_READ_PACKSWAP_SUPPORTED
- if (transformations & PNG_PACKSWAP)
- {
- sshift = (int)((row_info->width + 7) & 0x07);
- dshift = (int)((final_width + 7) & 0x07);
- s_start = 7;
- s_end = 0;
- s_inc = -1;
- }
-
- else
-#endif
- {
- sshift = 7 - (int)((row_info->width + 7) & 0x07);
- dshift = 7 - (int)((final_width + 7) & 0x07);
- s_start = 0;
- s_end = 7;
- s_inc = 1;
- }
-
- for (i = 0; i < row_info->width; i++)
- {
- v = (png_byte)((*sp >> sshift) & 0x01);
- for (j = 0; j < jstop; j++)
- {
- unsigned int tmp = *dp & (0x7f7f >> (7 - dshift));
- tmp |= v << dshift;
- *dp = (png_byte)(tmp & 0xff);
-
- if (dshift == s_end)
- {
- dshift = s_start;
- dp--;
- }
-
- else
- dshift += s_inc;
- }
-
- if (sshift == s_end)
- {
- sshift = s_start;
- sp--;
- }
-
- else
- sshift += s_inc;
- }
- break;
- }
-
- case 2:
- {
- png_bytep sp = row + (png_uint_32)((row_info->width - 1) >> 2);
- png_bytep dp = row + (png_uint_32)((final_width - 1) >> 2);
- int sshift, dshift;
- int s_start, s_end, s_inc;
- int jstop = png_pass_inc[pass];
- png_uint_32 i;
-
-#ifdef PNG_READ_PACKSWAP_SUPPORTED
- if (transformations & PNG_PACKSWAP)
- {
- sshift = (int)(((row_info->width + 3) & 0x03) << 1);
- dshift = (int)(((final_width + 3) & 0x03) << 1);
- s_start = 6;
- s_end = 0;
- s_inc = -2;
- }
-
- else
-#endif
- {
- sshift = (int)((3 - ((row_info->width + 3) & 0x03)) << 1);
- dshift = (int)((3 - ((final_width + 3) & 0x03)) << 1);
- s_start = 0;
- s_end = 6;
- s_inc = 2;
- }
-
- for (i = 0; i < row_info->width; i++)
- {
- png_byte v;
- int j;
-
- v = (png_byte)((*sp >> sshift) & 0x03);
- for (j = 0; j < jstop; j++)
- {
- unsigned int tmp = *dp & (0x3f3f >> (6 - dshift));
- tmp |= v << dshift;
- *dp = (png_byte)(tmp & 0xff);
-
- if (dshift == s_end)
- {
- dshift = s_start;
- dp--;
- }
-
- else
- dshift += s_inc;
- }
-
- if (sshift == s_end)
- {
- sshift = s_start;
- sp--;
- }
-
- else
- sshift += s_inc;
- }
- break;
- }
-
- case 4:
- {
- png_bytep sp = row + (png_size_t)((row_info->width - 1) >> 1);
- png_bytep dp = row + (png_size_t)((final_width - 1) >> 1);
- int sshift, dshift;
- int s_start, s_end, s_inc;
- png_uint_32 i;
- int jstop = png_pass_inc[pass];
-
-#ifdef PNG_READ_PACKSWAP_SUPPORTED
- if (transformations & PNG_PACKSWAP)
- {
- sshift = (int)(((row_info->width + 1) & 0x01) << 2);
- dshift = (int)(((final_width + 1) & 0x01) << 2);
- s_start = 4;
- s_end = 0;
- s_inc = -4;
- }
-
- else
-#endif
- {
- sshift = (int)((1 - ((row_info->width + 1) & 0x01)) << 2);
- dshift = (int)((1 - ((final_width + 1) & 0x01)) << 2);
- s_start = 0;
- s_end = 4;
- s_inc = 4;
- }
-
- for (i = 0; i < row_info->width; i++)
- {
- png_byte v = (png_byte)((*sp >> sshift) & 0x0f);
- int j;
-
- for (j = 0; j < jstop; j++)
- {
- unsigned int tmp = *dp & (0xf0f >> (4 - dshift));
- tmp |= v << dshift;
- *dp = (png_byte)(tmp & 0xff);
-
- if (dshift == s_end)
- {
- dshift = s_start;
- dp--;
- }
-
- else
- dshift += s_inc;
- }
-
- if (sshift == s_end)
- {
- sshift = s_start;
- sp--;
- }
-
- else
- sshift += s_inc;
- }
- break;
- }
-
- default:
- {
- png_size_t pixel_bytes = (row_info->pixel_depth >> 3);
-
- png_bytep sp = row + (png_size_t)(row_info->width - 1)
- * pixel_bytes;
-
- png_bytep dp = row + (png_size_t)(final_width - 1) * pixel_bytes;
-
- int jstop = png_pass_inc[pass];
- png_uint_32 i;
-
- for (i = 0; i < row_info->width; i++)
- {
- png_byte v[8]; /* SAFE; pixel_depth does not exceed 64 */
- int j;
-
- memcpy(v, sp, pixel_bytes);
-
- for (j = 0; j < jstop; j++)
- {
- memcpy(dp, v, pixel_bytes);
- dp -= pixel_bytes;
- }
-
- sp -= pixel_bytes;
- }
- break;
- }
- }
-
- row_info->width = final_width;
- row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, final_width);
- }
-#ifndef PNG_READ_PACKSWAP_SUPPORTED
- PNG_UNUSED(transformations) /* Silence compiler warning */
-#endif
-}
-#endif /* PNG_READ_INTERLACING_SUPPORTED */
-
-static void
-png_read_filter_row_sub(png_row_infop row_info, png_bytep row,
- png_const_bytep prev_row)
-{
- png_size_t i;
- png_size_t istop = row_info->rowbytes;
- unsigned int bpp = (row_info->pixel_depth + 7) >> 3;
- png_bytep rp = row + bpp;
-
- PNG_UNUSED(prev_row)
-
- for (i = bpp; i < istop; i++)
- {
- *rp = (png_byte)(((int)(*rp) + (int)(*(rp-bpp))) & 0xff);
- rp++;
- }
-}
-
-static void
-png_read_filter_row_up(png_row_infop row_info, png_bytep row,
- png_const_bytep prev_row)
-{
- png_size_t i;
- png_size_t istop = row_info->rowbytes;
- png_bytep rp = row;
- png_const_bytep pp = prev_row;
-
- for (i = 0; i < istop; i++)
- {
- *rp = (png_byte)(((int)(*rp) + (int)(*pp++)) & 0xff);
- rp++;
- }
-}
-
-static void
-png_read_filter_row_avg(png_row_infop row_info, png_bytep row,
- png_const_bytep prev_row)
-{
- png_size_t i;
- png_bytep rp = row;
- png_const_bytep pp = prev_row;
- unsigned int bpp = (row_info->pixel_depth + 7) >> 3;
- png_size_t istop = row_info->rowbytes - bpp;
-
- for (i = 0; i < bpp; i++)
- {
- *rp = (png_byte)(((int)(*rp) +
- ((int)(*pp++) / 2 )) & 0xff);
-
- rp++;
- }
-
- for (i = 0; i < istop; i++)
- {
- *rp = (png_byte)(((int)(*rp) +
- (int)(*pp++ + *(rp-bpp)) / 2 ) & 0xff);
-
- rp++;
- }
-}
-
-static void
-png_read_filter_row_paeth_1byte_pixel(png_row_infop row_info, png_bytep row,
- png_const_bytep prev_row)
-{
- png_bytep rp_end = row + row_info->rowbytes;
- int a, c;
-
- /* First pixel/byte */
- c = *prev_row++;
- a = *row + c;
- *row++ = (png_byte)a;
-
- /* Remainder */
- while (row < rp_end)
- {
- int b, pa, pb, pc, p;
-
- a &= 0xff; /* From previous iteration or start */
- b = *prev_row++;
-
- p = b - c;
- pc = a - c;
-
-# ifdef PNG_USE_ABS
- pa = abs(p);
- pb = abs(pc);
- pc = abs(p + pc);
-# else
- pa = p < 0 ? -p : p;
- pb = pc < 0 ? -pc : pc;
- pc = (p + pc) < 0 ? -(p + pc) : p + pc;
-# endif
-
- /* Find the best predictor, the least of pa, pb, pc favoring the earlier
- * ones in the case of a tie.
- */
- if (pb < pa) pa = pb, a = b;
- if (pc < pa) a = c;
-
- /* Calculate the current pixel in a, and move the previous row pixel to c
- * for the next time round the loop
- */
- c = b;
- a += *row;
- *row++ = (png_byte)a;
- }
-}
-
-static void
-png_read_filter_row_paeth_multibyte_pixel(png_row_infop row_info, png_bytep row,
- png_const_bytep prev_row)
-{
- int bpp = (row_info->pixel_depth + 7) >> 3;
- png_bytep rp_end = row + bpp;
-
- /* Process the first pixel in the row completely (this is the same as 'up'
- * because there is only one candidate predictor for the first row).
- */
- while (row < rp_end)
- {
- int a = *row + *prev_row++;
- *row++ = (png_byte)a;
- }
-
- /* Remainder */
- rp_end += row_info->rowbytes - bpp;
-
- while (row < rp_end)
- {
- int a, b, c, pa, pb, pc, p;
-
- c = *(prev_row - bpp);
- a = *(row - bpp);
- b = *prev_row++;
-
- p = b - c;
- pc = a - c;
-
-# ifdef PNG_USE_ABS
- pa = abs(p);
- pb = abs(pc);
- pc = abs(p + pc);
-# else
- pa = p < 0 ? -p : p;
- pb = pc < 0 ? -pc : pc;
- pc = (p + pc) < 0 ? -(p + pc) : p + pc;
-# endif
-
- if (pb < pa) pa = pb, a = b;
- if (pc < pa) a = c;
-
- c = b;
- a += *row;
- *row++ = (png_byte)a;
- }
-}
-
-static void
-png_init_filter_functions(png_structrp pp)
- /* This function is called once for every PNG image to set the
- * implementations required to reverse the filtering of PNG rows. Reversing
- * the filter is the first transformation performed on the row data. It is
- * performed in place, therefore an implementation can be selected based on
- * the image pixel format. If the implementation depends on image width then
- * take care to ensure that it works correctly if the image is interlaced -
- * interlacing causes the actual row width to vary.
- */
-{
- unsigned int bpp = (pp->pixel_depth + 7) >> 3;
-
- pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub;
- pp->read_filter[PNG_FILTER_VALUE_UP-1] = png_read_filter_row_up;
- pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg;
- if (bpp == 1)
- pp->read_filter[PNG_FILTER_VALUE_PAETH-1] =
- png_read_filter_row_paeth_1byte_pixel;
- else
- pp->read_filter[PNG_FILTER_VALUE_PAETH-1] =
- png_read_filter_row_paeth_multibyte_pixel;
-
-#ifdef PNG_FILTER_OPTIMIZATIONS
- /* To use this define PNG_FILTER_OPTIMIZATIONS as the name of a function to
- * call to install hardware optimizations for the above functions; simply
- * replace whatever elements of the pp->read_filter[] array with a hardware
- * specific (or, for that matter, generic) optimization.
- *
- * To see an example of this examine what configure.ac does when
- * --enable-arm-neon is specified on the command line.
- */
- PNG_FILTER_OPTIMIZATIONS(pp, bpp);
-#endif
-}
-
-void /* PRIVATE */
-png_read_filter_row(png_structrp pp, png_row_infop row_info, png_bytep row,
- png_const_bytep prev_row, int filter)
-{
- /* OPTIMIZATION: DO NOT MODIFY THIS FUNCTION, instead #define
- * PNG_FILTER_OPTIMIZATIONS to a function that overrides the generic
- * implementations. See png_init_filter_functions above.
- */
- if (pp->read_filter[0] == NULL)
- png_init_filter_functions(pp);
- if (filter > PNG_FILTER_VALUE_NONE && filter < PNG_FILTER_VALUE_LAST)
- pp->read_filter[filter-1](row_info, row, prev_row);
-}
-
-#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
-void /* PRIVATE */
-png_read_IDAT_data(png_structrp png_ptr, png_bytep output,
- png_alloc_size_t avail_out)
-{
- /* Loop reading IDATs and decompressing the result into output[avail_out] */
- png_ptr->zstream.next_out = output;
- png_ptr->zstream.avail_out = 0; /* safety: set below */
-
- if (output == NULL)
- avail_out = 0;
-
- do
- {
- int ret;
- png_byte tmpbuf[PNG_INFLATE_BUF_SIZE];
-
- if (png_ptr->zstream.avail_in == 0)
- {
- uInt avail_in;
- png_bytep buffer;
-
- while (png_ptr->idat_size == 0)
- {
- png_crc_finish(png_ptr, 0);
-
- png_ptr->idat_size = png_read_chunk_header(png_ptr);
- /* This is an error even in the 'check' case because the code just
- * consumed a non-IDAT header.
- */
- if (png_ptr->chunk_name != png_IDAT)
- png_error(png_ptr, "Not enough image data");
- }
-
- avail_in = png_ptr->IDAT_read_size;
-
- if (avail_in > png_ptr->idat_size)
- avail_in = (uInt)png_ptr->idat_size;
-
- /* A PNG with a gradually increasing IDAT size will defeat this attempt
- * to minimize memory usage by causing lots of re-allocs, but
- * realistically doing IDAT_read_size re-allocs is not likely to be a
- * big problem.
- */
- buffer = png_read_buffer(png_ptr, avail_in, 0/*error*/);
-
- png_crc_read(png_ptr, buffer, avail_in);
- png_ptr->idat_size -= avail_in;
-
- png_ptr->zstream.next_in = buffer;
- png_ptr->zstream.avail_in = avail_in;
- }
-
- /* And set up the output side. */
- if (output != NULL) /* standard read */
- {
- uInt out = ZLIB_IO_MAX;
-
- if (out > avail_out)
- out = (uInt)avail_out;
-
- avail_out -= out;
- png_ptr->zstream.avail_out = out;
- }
-
- else /* after last row, checking for end */
- {
- png_ptr->zstream.next_out = tmpbuf;
- png_ptr->zstream.avail_out = (sizeof tmpbuf);
- }
-
- /* Use NO_FLUSH; this gives zlib the maximum opportunity to optimize the
- * process. If the LZ stream is truncated the sequential reader will
- * terminally damage the stream, above, by reading the chunk header of the
- * following chunk (it then exits with png_error).
- *
- * TODO: deal more elegantly with truncated IDAT lists.
- */
- ret = inflate(&png_ptr->zstream, Z_NO_FLUSH);
-
- /* Take the unconsumed output back. */
- if (output != NULL)
- avail_out += png_ptr->zstream.avail_out;
-
- else /* avail_out counts the extra bytes */
- avail_out += (sizeof tmpbuf) - png_ptr->zstream.avail_out;
-
- png_ptr->zstream.avail_out = 0;
-
- if (ret == Z_STREAM_END)
- {
- /* Do this for safety; we won't read any more into this row. */
- png_ptr->zstream.next_out = NULL;
-
- png_ptr->mode |= PNG_AFTER_IDAT;
- png_ptr->flags |= PNG_FLAG_ZSTREAM_ENDED;
-
- if (png_ptr->zstream.avail_in > 0 || png_ptr->idat_size > 0)
- png_chunk_benign_error(png_ptr, "Extra compressed data");
- break;
- }
-
- if (ret != Z_OK)
- {
- png_zstream_error(png_ptr, ret);
-
- if (output != NULL)
- png_chunk_error(png_ptr, png_ptr->zstream.msg);
-
- else /* checking */
- {
- png_chunk_benign_error(png_ptr, png_ptr->zstream.msg);
- return;
- }
- }
- } while (avail_out > 0);
-
- if (avail_out > 0)
- {
- /* The stream ended before the image; this is the same as too few IDATs so
- * should be handled the same way.
- */
- if (output != NULL)
- png_error(png_ptr, "Not enough image data");
-
- else /* the deflate stream contained extra data */
- png_chunk_benign_error(png_ptr, "Too much image data");
- }
-}
-
-void /* PRIVATE */
-png_read_finish_IDAT(png_structrp png_ptr)
-{
- /* We don't need any more data and the stream should have ended, however the
- * LZ end code may actually not have been processed. In this case we must
- * read it otherwise stray unread IDAT data or, more likely, an IDAT chunk
- * may still remain to be consumed.
- */
- if (!(png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED))
- {
- /* The NULL causes png_read_IDAT_data to swallow any remaining bytes in
- * the compressed stream, but the stream may be damaged too, so even after
- * this call we may need to terminate the zstream ownership.
- */
- png_read_IDAT_data(png_ptr, NULL, 0);
- png_ptr->zstream.next_out = NULL; /* safety */
-
- /* Now clear everything out for safety; the following may not have been
- * done.
- */
- if (!(png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED))
- {
- png_ptr->mode |= PNG_AFTER_IDAT;
- png_ptr->flags |= PNG_FLAG_ZSTREAM_ENDED;
- }
- }
-
- /* If the zstream has not been released do it now *and* terminate the reading
- * of the final IDAT chunk.
- */
- if (png_ptr->zowner == png_IDAT)
- {
- /* Always do this; the pointers otherwise point into the read buffer. */
- png_ptr->zstream.next_in = NULL;
- png_ptr->zstream.avail_in = 0;
-
- /* Now we no longer own the zstream. */
- png_ptr->zowner = 0;
-
- /* The slightly weird semantics of the sequential IDAT reading is that we
- * are always in or at the end of an IDAT chunk, so we always need to do a
- * crc_finish here. If idat_size is non-zero we also need to read the
- * spurious bytes at the end of the chunk now.
- */
- (void)png_crc_finish(png_ptr, png_ptr->idat_size);
- }
-}
-
-void /* PRIVATE */
-png_read_finish_row(png_structrp png_ptr)
-{
-#ifdef PNG_READ_INTERLACING_SUPPORTED
- /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
-
- /* Start of interlace block */
- static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
-
- /* Offset to next interlace block */
- static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
-
- /* Start of interlace block in the y direction */
- static PNG_CONST png_byte png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
-
- /* Offset to next interlace block in the y direction */
- static PNG_CONST png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
-#endif /* PNG_READ_INTERLACING_SUPPORTED */
-
- png_debug(1, "in png_read_finish_row");
- png_ptr->row_number++;
- if (png_ptr->row_number < png_ptr->num_rows)
- return;
-
-#ifdef PNG_READ_INTERLACING_SUPPORTED
- if (png_ptr->interlaced)
- {
- png_ptr->row_number = 0;
-
- /* TO DO: don't do this if prev_row isn't needed (requires
- * read-ahead of the next row's filter byte.
- */
- memset(png_ptr->prev_row, 0, png_ptr->rowbytes + 1);
-
- do
- {
- png_ptr->pass++;
-
- if (png_ptr->pass >= 7)
- break;
-
- png_ptr->iwidth = (png_ptr->width +
- png_pass_inc[png_ptr->pass] - 1 -
- png_pass_start[png_ptr->pass]) /
- png_pass_inc[png_ptr->pass];
-
- if (!(png_ptr->transformations & PNG_INTERLACE))
- {
- png_ptr->num_rows = (png_ptr->height +
- png_pass_yinc[png_ptr->pass] - 1 -
- png_pass_ystart[png_ptr->pass]) /
- png_pass_yinc[png_ptr->pass];
- }
-
- else /* if (png_ptr->transformations & PNG_INTERLACE) */
- break; /* libpng deinterlacing sees every row */
-
- } while (png_ptr->num_rows == 0 || png_ptr->iwidth == 0);
-
- if (png_ptr->pass < 7)
- return;
- }
-#endif /* PNG_READ_INTERLACING_SUPPORTED */
-
- /* Here after at the end of the last row of the last pass. */
- png_read_finish_IDAT(png_ptr);
-}
-#endif /* PNG_SEQUENTIAL_READ_SUPPORTED */
-
-void /* PRIVATE */
-png_read_start_row(png_structrp png_ptr)
-{
-#ifdef PNG_READ_INTERLACING_SUPPORTED
- /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
-
- /* Start of interlace block */
- static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
-
- /* Offset to next interlace block */
- static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
-
- /* Start of interlace block in the y direction */
- static PNG_CONST png_byte png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
-
- /* Offset to next interlace block in the y direction */
- static PNG_CONST png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
-#endif
-
- int max_pixel_depth;
- png_size_t row_bytes;
-
- png_debug(1, "in png_read_start_row");
-
-#ifdef PNG_READ_TRANSFORMS_SUPPORTED
- png_init_read_transformations(png_ptr);
-#endif
-#ifdef PNG_READ_INTERLACING_SUPPORTED
- if (png_ptr->interlaced)
- {
- if (!(png_ptr->transformations & PNG_INTERLACE))
- png_ptr->num_rows = (png_ptr->height + png_pass_yinc[0] - 1 -
- png_pass_ystart[0]) / png_pass_yinc[0];
-
- else
- png_ptr->num_rows = png_ptr->height;
-
- png_ptr->iwidth = (png_ptr->width +
- png_pass_inc[png_ptr->pass] - 1 -
- png_pass_start[png_ptr->pass]) /
- png_pass_inc[png_ptr->pass];
- }
-
- else
-#endif /* PNG_READ_INTERLACING_SUPPORTED */
- {
- png_ptr->num_rows = png_ptr->height;
- png_ptr->iwidth = png_ptr->width;
- }
-
- max_pixel_depth = png_ptr->pixel_depth;
-
- /* WARNING: * png_read_transform_info (pngrtran.c) performs a simpliar set of
- * calculations to calculate the final pixel depth, then
- * png_do_read_transforms actually does the transforms. This means that the
- * code which effectively calculates this value is actually repeated in three
- * separate places. They must all match. Innocent changes to the order of
- * transformations can and will break libpng in a way that causes memory
- * overwrites.
- *
- * TODO: fix this.
- */
-#ifdef PNG_READ_PACK_SUPPORTED
- if ((png_ptr->transformations & PNG_PACK) && png_ptr->bit_depth < 8)
- max_pixel_depth = 8;
-#endif
-
-#ifdef PNG_READ_EXPAND_SUPPORTED
- if (png_ptr->transformations & PNG_EXPAND)
- {
- if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
- {
- if (png_ptr->num_trans)
- max_pixel_depth = 32;
-
- else
- max_pixel_depth = 24;
- }
-
- else if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY)
- {
- if (max_pixel_depth < 8)
- max_pixel_depth = 8;
-
- if (png_ptr->num_trans)
- max_pixel_depth *= 2;
- }
-
- else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB)
- {
- if (png_ptr->num_trans)
- {
- max_pixel_depth *= 4;
- max_pixel_depth /= 3;
- }
- }
- }
-#endif
-
-#ifdef PNG_READ_EXPAND_16_SUPPORTED
- if (png_ptr->transformations & PNG_EXPAND_16)
- {
-# ifdef PNG_READ_EXPAND_SUPPORTED
- /* In fact it is an error if it isn't supported, but checking is
- * the safe way.
- */
- if (png_ptr->transformations & PNG_EXPAND)
- {
- if (png_ptr->bit_depth < 16)
- max_pixel_depth *= 2;
- }
- else
-# endif
- png_ptr->transformations &= ~PNG_EXPAND_16;
- }
-#endif
-
-#ifdef PNG_READ_FILLER_SUPPORTED
- if (png_ptr->transformations & (PNG_FILLER))
- {
- if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY)
- {
- if (max_pixel_depth <= 8)
- max_pixel_depth = 16;
-
- else
- max_pixel_depth = 32;
- }
-
- else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB ||
- png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
- {
- if (max_pixel_depth <= 32)
- max_pixel_depth = 32;
-
- else
- max_pixel_depth = 64;
- }
- }
-#endif
-
-#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
- if (png_ptr->transformations & PNG_GRAY_TO_RGB)
- {
- if (
-#ifdef PNG_READ_EXPAND_SUPPORTED
- (png_ptr->num_trans && (png_ptr->transformations & PNG_EXPAND)) ||
-#endif
-#ifdef PNG_READ_FILLER_SUPPORTED
- (png_ptr->transformations & (PNG_FILLER)) ||
-#endif
- png_ptr->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
- {
- if (max_pixel_depth <= 16)
- max_pixel_depth = 32;
-
- else
- max_pixel_depth = 64;
- }
-
- else
- {
- if (max_pixel_depth <= 8)
- {
- if (png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
- max_pixel_depth = 32;
-
- else
- max_pixel_depth = 24;
- }
-
- else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
- max_pixel_depth = 64;
-
- else
- max_pixel_depth = 48;
- }
- }
-#endif
-
-#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) && \
-defined(PNG_USER_TRANSFORM_PTR_SUPPORTED)
- if (png_ptr->transformations & PNG_USER_TRANSFORM)
- {
- int user_pixel_depth = png_ptr->user_transform_depth *
- png_ptr->user_transform_channels;
-
- if (user_pixel_depth > max_pixel_depth)
- max_pixel_depth = user_pixel_depth;
- }
-#endif
-
- /* This value is stored in png_struct and double checked in the row read
- * code.
- */
- png_ptr->maximum_pixel_depth = (png_byte)max_pixel_depth;
- png_ptr->transformed_pixel_depth = 0; /* calculated on demand */
-
- /* Align the width on the next larger 8 pixels. Mainly used
- * for interlacing
- */
- row_bytes = ((png_ptr->width + 7) & ~((png_uint_32)7));
- /* Calculate the maximum bytes needed, adding a byte and a pixel
- * for safety's sake
- */
- row_bytes = PNG_ROWBYTES(max_pixel_depth, row_bytes) +
- 1 + ((max_pixel_depth + 7) >> 3);
-
-#ifdef PNG_MAX_MALLOC_64K
- if (row_bytes > (png_uint_32)65536L)
- png_error(png_ptr, "This image requires a row greater than 64KB");
-#endif
-
- if (row_bytes + 48 > png_ptr->old_big_row_buf_size)
- {
- png_free(png_ptr, png_ptr->big_row_buf);
- png_free(png_ptr, png_ptr->big_prev_row);
-
- if (png_ptr->interlaced)
- png_ptr->big_row_buf = (png_bytep)png_calloc(png_ptr,
- row_bytes + 48);
-
- else
- png_ptr->big_row_buf = (png_bytep)png_malloc(png_ptr, row_bytes + 48);
-
- png_ptr->big_prev_row = (png_bytep)png_malloc(png_ptr, row_bytes + 48);
-
-#ifdef PNG_ALIGNED_MEMORY_SUPPORTED
- /* Use 16-byte aligned memory for row_buf with at least 16 bytes
- * of padding before and after row_buf; treat prev_row similarly.
- * NOTE: the alignment is to the start of the pixels, one beyond the start
- * of the buffer, because of the filter byte. Prior to libpng 1.5.6 this
- * was incorrect; the filter byte was aligned, which had the exact
- * opposite effect of that intended.
- */
- {
- png_bytep temp = png_ptr->big_row_buf + 32;
- int extra = (int)((temp - (png_bytep)0) & 0x0f);
- png_ptr->row_buf = temp - extra - 1/*filter byte*/;
-
- temp = png_ptr->big_prev_row + 32;
- extra = (int)((temp - (png_bytep)0) & 0x0f);
- png_ptr->prev_row = temp - extra - 1/*filter byte*/;
- }
-
-#else
- /* Use 31 bytes of padding before and 17 bytes after row_buf. */
- png_ptr->row_buf = png_ptr->big_row_buf + 31;
- png_ptr->prev_row = png_ptr->big_prev_row + 31;
-#endif
- png_ptr->old_big_row_buf_size = row_bytes + 48;
- }
-
-#ifdef PNG_MAX_MALLOC_64K
- if (png_ptr->rowbytes > 65535)
- png_error(png_ptr, "This image requires a row greater than 64KB");
-
-#endif
- if (png_ptr->rowbytes > (PNG_SIZE_MAX - 1))
- png_error(png_ptr, "Row has too many bytes to allocate in memory");
-
- memset(png_ptr->prev_row, 0, png_ptr->rowbytes + 1);
-
- png_debug1(3, "width = %u,", png_ptr->width);
- png_debug1(3, "height = %u,", png_ptr->height);
- png_debug1(3, "iwidth = %u,", png_ptr->iwidth);
- png_debug1(3, "num_rows = %u,", png_ptr->num_rows);
- png_debug1(3, "rowbytes = %lu,", (unsigned long)png_ptr->rowbytes);
- png_debug1(3, "irowbytes = %lu",
- (unsigned long)PNG_ROWBYTES(png_ptr->pixel_depth, png_ptr->iwidth) + 1);
-
- /* The sequential reader needs a buffer for IDAT, but the progressive reader
- * does not, so free the read buffer now regardless; the sequential reader
- * reallocates it on demand.
- */
- if (png_ptr->read_buffer)
- {
- png_bytep buffer = png_ptr->read_buffer;
-
- png_ptr->read_buffer_size = 0;
- png_ptr->read_buffer = NULL;
- png_free(png_ptr, buffer);
- }
-
- /* Finally claim the zstream for the inflate of the IDAT data, use the bits
- * value from the stream (note that this will result in a fatal error if the
- * IDAT stream has a bogus deflate header window_bits value, but this should
- * not be happening any longer!)
- */
- if (png_inflate_claim(png_ptr, png_IDAT) != Z_OK)
- png_error(png_ptr, png_ptr->zstream.msg);
-
- png_ptr->flags |= PNG_FLAG_ROW_INIT;
-}
-#endif /* PNG_READ_SUPPORTED */
+
+/* pngrutil.c - utilities to read a PNG file
+ *
+ * Last changed in libpng 1.6.20 [December 3, 2015]
+ * Copyright (c) 1998-2015 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ * This file contains routines that are only called from within
+ * libpng itself during the course of reading an image.
+ */
+
+#include "pngpriv.h"
+
+#ifdef PNG_READ_SUPPORTED
+
+png_uint_32 PNGAPI
+png_get_uint_31(png_const_structrp png_ptr, png_const_bytep buf)
+{
+ png_uint_32 uval = png_get_uint_32(buf);
+
+ if (uval > PNG_UINT_31_MAX)
+ png_error(png_ptr, "PNG unsigned integer out of range");
+
+ return (uval);
+}
+
+#if defined(PNG_READ_gAMA_SUPPORTED) || defined(PNG_READ_cHRM_SUPPORTED)
+/* The following is a variation on the above for use with the fixed
+ * point values used for gAMA and cHRM. Instead of png_error it
+ * issues a warning and returns (-1) - an invalid value because both
+ * gAMA and cHRM use *unsigned* integers for fixed point values.
+ */
+#define PNG_FIXED_ERROR (-1)
+
+static png_fixed_point /* PRIVATE */
+png_get_fixed_point(png_structrp png_ptr, png_const_bytep buf)
+{
+ png_uint_32 uval = png_get_uint_32(buf);
+
+ if (uval <= PNG_UINT_31_MAX)
+ return (png_fixed_point)uval; /* known to be in range */
+
+ /* The caller can turn off the warning by passing NULL. */
+ if (png_ptr != NULL)
+ png_warning(png_ptr, "PNG fixed point integer out of range");
+
+ return PNG_FIXED_ERROR;
+}
+#endif
+
+#ifdef PNG_READ_INT_FUNCTIONS_SUPPORTED
+/* NOTE: the read macros will obscure these definitions, so that if
+ * PNG_USE_READ_MACROS is set the library will not use them internally,
+ * but the APIs will still be available externally.
+ *
+ * The parentheses around "PNGAPI function_name" in the following three
+ * functions are necessary because they allow the macros to co-exist with
+ * these (unused but exported) functions.
+ */
+
+/* Grab an unsigned 32-bit integer from a buffer in big-endian format. */
+png_uint_32 (PNGAPI
+png_get_uint_32)(png_const_bytep buf)
+{
+ png_uint_32 uval =
+ ((png_uint_32)(*(buf )) << 24) +
+ ((png_uint_32)(*(buf + 1)) << 16) +
+ ((png_uint_32)(*(buf + 2)) << 8) +
+ ((png_uint_32)(*(buf + 3)) ) ;
+
+ return uval;
+}
+
+/* Grab a signed 32-bit integer from a buffer in big-endian format. The
+ * data is stored in the PNG file in two's complement format and there
+ * is no guarantee that a 'png_int_32' is exactly 32 bits, therefore
+ * the following code does a two's complement to native conversion.
+ */
+png_int_32 (PNGAPI
+png_get_int_32)(png_const_bytep buf)
+{
+ png_uint_32 uval = png_get_uint_32(buf);
+ if ((uval & 0x80000000) == 0) /* non-negative */
+ return uval;
+
+ uval = (uval ^ 0xffffffff) + 1; /* 2's complement: -x = ~x+1 */
+ if ((uval & 0x80000000) == 0) /* no overflow */
+ return -(png_int_32)uval;
+ /* The following has to be safe; this function only gets called on PNG data
+ * and if we get here that data is invalid. 0 is the most safe value and
+ * if not then an attacker would surely just generate a PNG with 0 instead.
+ */
+ return 0;
+}
+
+/* Grab an unsigned 16-bit integer from a buffer in big-endian format. */
+png_uint_16 (PNGAPI
+png_get_uint_16)(png_const_bytep buf)
+{
+ /* ANSI-C requires an int value to accomodate at least 16 bits so this
+ * works and allows the compiler not to worry about possible narrowing
+ * on 32-bit systems. (Pre-ANSI systems did not make integers smaller
+ * than 16 bits either.)
+ */
+ unsigned int val =
+ ((unsigned int)(*buf) << 8) +
+ ((unsigned int)(*(buf + 1)));
+
+ return (png_uint_16)val;
+}
+
+#endif /* READ_INT_FUNCTIONS */
+
+/* Read and check the PNG file signature */
+void /* PRIVATE */
+png_read_sig(png_structrp png_ptr, png_inforp info_ptr)
+{
+ png_size_t num_checked, num_to_check;
+
+ /* Exit if the user application does not expect a signature. */
+ if (png_ptr->sig_bytes >= 8)
+ return;
+
+ num_checked = png_ptr->sig_bytes;
+ num_to_check = 8 - num_checked;
+
+#ifdef PNG_IO_STATE_SUPPORTED
+ png_ptr->io_state = PNG_IO_READING | PNG_IO_SIGNATURE;
+#endif
+
+ /* The signature must be serialized in a single I/O call. */
+ png_read_data(png_ptr, &(info_ptr->signature[num_checked]), num_to_check);
+ png_ptr->sig_bytes = 8;
+
+ if (png_sig_cmp(info_ptr->signature, num_checked, num_to_check) != 0)
+ {
+ if (num_checked < 4 &&
+ png_sig_cmp(info_ptr->signature, num_checked, num_to_check - 4))
+ png_error(png_ptr, "Not a PNG file");
+ else
+ png_error(png_ptr, "PNG file corrupted by ASCII conversion");
+ }
+ if (num_checked < 3)
+ png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE;
+}
+
+/* Read the chunk header (length + type name).
+ * Put the type name into png_ptr->chunk_name, and return the length.
+ */
+png_uint_32 /* PRIVATE */
+png_read_chunk_header(png_structrp png_ptr)
+{
+ png_byte buf[8];
+ png_uint_32 length;
+
+#ifdef PNG_IO_STATE_SUPPORTED
+ png_ptr->io_state = PNG_IO_READING | PNG_IO_CHUNK_HDR;
+#endif
+
+ /* Read the length and the chunk name.
+ * This must be performed in a single I/O call.
+ */
+ png_read_data(png_ptr, buf, 8);
+ length = png_get_uint_31(png_ptr, buf);
+
+ /* Put the chunk name into png_ptr->chunk_name. */
+ png_ptr->chunk_name = PNG_CHUNK_FROM_STRING(buf+4);
+
+ png_debug2(0, "Reading %lx chunk, length = %lu",
+ (unsigned long)png_ptr->chunk_name, (unsigned long)length);
+
+ /* Reset the crc and run it over the chunk name. */
+ png_reset_crc(png_ptr);
+ png_calculate_crc(png_ptr, buf + 4, 4);
+
+ /* Check to see if chunk name is valid. */
+ png_check_chunk_name(png_ptr, png_ptr->chunk_name);
+
+#ifdef PNG_IO_STATE_SUPPORTED
+ png_ptr->io_state = PNG_IO_READING | PNG_IO_CHUNK_DATA;
+#endif
+
+ return length;
+}
+
+/* Read data, and (optionally) run it through the CRC. */
+void /* PRIVATE */
+png_crc_read(png_structrp png_ptr, png_bytep buf, png_uint_32 length)
+{
+ if (png_ptr == NULL)
+ return;
+
+ png_read_data(png_ptr, buf, length);
+ png_calculate_crc(png_ptr, buf, length);
+}
+
+/* Optionally skip data and then check the CRC. Depending on whether we
+ * are reading an ancillary or critical chunk, and how the program has set
+ * things up, we may calculate the CRC on the data and print a message.
+ * Returns '1' if there was a CRC error, '0' otherwise.
+ */
+int /* PRIVATE */
+png_crc_finish(png_structrp png_ptr, png_uint_32 skip)
+{
+ /* The size of the local buffer for inflate is a good guess as to a
+ * reasonable size to use for buffering reads from the application.
+ */
+ while (skip > 0)
+ {
+ png_uint_32 len;
+ png_byte tmpbuf[PNG_INFLATE_BUF_SIZE];
+
+ len = (sizeof tmpbuf);
+ if (len > skip)
+ len = skip;
+ skip -= len;
+
+ png_crc_read(png_ptr, tmpbuf, len);
+ }
+
+ if (png_crc_error(png_ptr) != 0)
+ {
+ if (PNG_CHUNK_ANCILLARY(png_ptr->chunk_name) != 0 ?
+ (png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN) == 0 :
+ (png_ptr->flags & PNG_FLAG_CRC_CRITICAL_USE) != 0)
+ {
+ png_chunk_warning(png_ptr, "CRC error");
+ }
+
+ else
+ png_chunk_error(png_ptr, "CRC error");
+
+ return (1);
+ }
+
+ return (0);
+}
+
+/* Compare the CRC stored in the PNG file with that calculated by libpng from
+ * the data it has read thus far.
+ */
+int /* PRIVATE */
+png_crc_error(png_structrp png_ptr)
+{
+ png_byte crc_bytes[4];
+ png_uint_32 crc;
+ int need_crc = 1;
+
+ if (PNG_CHUNK_ANCILLARY(png_ptr->chunk_name) != 0)
+ {
+ if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_MASK) ==
+ (PNG_FLAG_CRC_ANCILLARY_USE | PNG_FLAG_CRC_ANCILLARY_NOWARN))
+ need_crc = 0;
+ }
+
+ else /* critical */
+ {
+ if ((png_ptr->flags & PNG_FLAG_CRC_CRITICAL_IGNORE) != 0)
+ need_crc = 0;
+ }
+
+#ifdef PNG_IO_STATE_SUPPORTED
+ png_ptr->io_state = PNG_IO_READING | PNG_IO_CHUNK_CRC;
+#endif
+
+ /* The chunk CRC must be serialized in a single I/O call. */
+ png_read_data(png_ptr, crc_bytes, 4);
+
+ if (need_crc != 0)
+ {
+ crc = png_get_uint_32(crc_bytes);
+ return ((int)(crc != png_ptr->crc));
+ }
+
+ else
+ return (0);
+}
+
+#if defined(PNG_READ_iCCP_SUPPORTED) || defined(PNG_READ_iTXt_SUPPORTED) ||\
+ defined(PNG_READ_pCAL_SUPPORTED) || defined(PNG_READ_sCAL_SUPPORTED) ||\
+ defined(PNG_READ_sPLT_SUPPORTED) || defined(PNG_READ_tEXt_SUPPORTED) ||\
+ defined(PNG_READ_zTXt_SUPPORTED) || defined(PNG_SEQUENTIAL_READ_SUPPORTED)
+/* Manage the read buffer; this simply reallocates the buffer if it is not small
+ * enough (or if it is not allocated). The routine returns a pointer to the
+ * buffer; if an error occurs and 'warn' is set the routine returns NULL, else
+ * it will call png_error (via png_malloc) on failure. (warn == 2 means
+ * 'silent').
+ */
+static png_bytep
+png_read_buffer(png_structrp png_ptr, png_alloc_size_t new_size, int warn)
+{
+ png_bytep buffer = png_ptr->read_buffer;
+
+ if (buffer != NULL && new_size > png_ptr->read_buffer_size)
+ {
+ png_ptr->read_buffer = NULL;
+ png_ptr->read_buffer = NULL;
+ png_ptr->read_buffer_size = 0;
+ png_free(png_ptr, buffer);
+ buffer = NULL;
+ }
+
+ if (buffer == NULL)
+ {
+ buffer = png_voidcast(png_bytep, png_malloc_base(png_ptr, new_size));
+
+ if (buffer != NULL)
+ {
+ png_ptr->read_buffer = buffer;
+ png_ptr->read_buffer_size = new_size;
+ }
+
+ else if (warn < 2) /* else silent */
+ {
+ if (warn != 0)
+ png_chunk_warning(png_ptr, "insufficient memory to read chunk");
+
+ else
+ png_chunk_error(png_ptr, "insufficient memory to read chunk");
+ }
+ }
+
+ return buffer;
+}
+#endif /* READ_iCCP|iTXt|pCAL|sCAL|sPLT|tEXt|zTXt|SEQUENTIAL_READ */
+
+/* png_inflate_claim: claim the zstream for some nefarious purpose that involves
+ * decompression. Returns Z_OK on success, else a zlib error code. It checks
+ * the owner but, in final release builds, just issues a warning if some other
+ * chunk apparently owns the stream. Prior to release it does a png_error.
+ */
+static int
+png_inflate_claim(png_structrp png_ptr, png_uint_32 owner)
+{
+ if (png_ptr->zowner != 0)
+ {
+ char msg[64];
+
+ PNG_STRING_FROM_CHUNK(msg, png_ptr->zowner);
+ /* So the message that results is "<chunk> using zstream"; this is an
+ * internal error, but is very useful for debugging. i18n requirements
+ * are minimal.
+ */
+ (void)png_safecat(msg, (sizeof msg), 4, " using zstream");
+#if PNG_RELEASE_BUILD
+ png_chunk_warning(png_ptr, msg);
+ png_ptr->zowner = 0;
+#else
+ png_chunk_error(png_ptr, msg);
+#endif
+ }
+
+ /* Implementation note: unlike 'png_deflate_claim' this internal function
+ * does not take the size of the data as an argument. Some efficiency could
+ * be gained by using this when it is known *if* the zlib stream itself does
+ * not record the number; however, this is an illusion: the original writer
+ * of the PNG may have selected a lower window size, and we really must
+ * follow that because, for systems with with limited capabilities, we
+ * would otherwise reject the application's attempts to use a smaller window
+ * size (zlib doesn't have an interface to say "this or lower"!).
+ *
+ * inflateReset2 was added to zlib 1.2.4; before this the window could not be
+ * reset, therefore it is necessary to always allocate the maximum window
+ * size with earlier zlibs just in case later compressed chunks need it.
+ */
+ {
+ int ret; /* zlib return code */
+#if PNG_ZLIB_VERNUM >= 0x1240
+
+# if defined(PNG_SET_OPTION_SUPPORTED) && defined(PNG_MAXIMUM_INFLATE_WINDOW)
+ int window_bits;
+
+ if (((png_ptr->options >> PNG_MAXIMUM_INFLATE_WINDOW) & 3) ==
+ PNG_OPTION_ON)
+ {
+ window_bits = 15;
+ png_ptr->zstream_start = 0; /* fixed window size */
+ }
+
+ else
+ {
+ window_bits = 0;
+ png_ptr->zstream_start = 1;
+ }
+# else
+# define window_bits 0
+# endif
+#endif
+
+ /* Set this for safety, just in case the previous owner left pointers to
+ * memory allocations.
+ */
+ png_ptr->zstream.next_in = NULL;
+ png_ptr->zstream.avail_in = 0;
+ png_ptr->zstream.next_out = NULL;
+ png_ptr->zstream.avail_out = 0;
+
+ if ((png_ptr->flags & PNG_FLAG_ZSTREAM_INITIALIZED) != 0)
+ {
+#if PNG_ZLIB_VERNUM < 0x1240
+ ret = inflateReset(&png_ptr->zstream);
+#else
+ ret = inflateReset2(&png_ptr->zstream, window_bits);
+#endif
+ }
+
+ else
+ {
+#if PNG_ZLIB_VERNUM < 0x1240
+ ret = inflateInit(&png_ptr->zstream);
+#else
+ ret = inflateInit2(&png_ptr->zstream, window_bits);
+#endif
+
+ if (ret == Z_OK)
+ png_ptr->flags |= PNG_FLAG_ZSTREAM_INITIALIZED;
+ }
+
+ if (ret == Z_OK)
+ png_ptr->zowner = owner;
+
+ else
+ png_zstream_error(png_ptr, ret);
+
+ return ret;
+ }
+
+#ifdef window_bits
+# undef window_bits
+#endif
+}
+
+#if PNG_ZLIB_VERNUM >= 0x1240
+/* Handle the start of the inflate stream if we called inflateInit2(strm,0);
+ * in this case some zlib versions skip validation of the CINFO field and, in
+ * certain circumstances, libpng may end up displaying an invalid image, in
+ * contrast to implementations that call zlib in the normal way (e.g. libpng
+ * 1.5).
+ */
+int /* PRIVATE */
+png_zlib_inflate(png_structrp png_ptr, int flush)
+{
+ if (png_ptr->zstream_start && png_ptr->zstream.avail_in > 0)
+ {
+ if ((*png_ptr->zstream.next_in >> 4) > 7)
+ {
+ png_ptr->zstream.msg = "invalid window size (libpng)";
+ return Z_DATA_ERROR;
+ }
+
+ png_ptr->zstream_start = 0;
+ }
+
+ return inflate(&png_ptr->zstream, flush);
+}
+#endif /* Zlib >= 1.2.4 */
+
+#ifdef PNG_READ_COMPRESSED_TEXT_SUPPORTED
+/* png_inflate now returns zlib error codes including Z_OK and Z_STREAM_END to
+ * allow the caller to do multiple calls if required. If the 'finish' flag is
+ * set Z_FINISH will be passed to the final inflate() call and Z_STREAM_END must
+ * be returned or there has been a problem, otherwise Z_SYNC_FLUSH is used and
+ * Z_OK or Z_STREAM_END will be returned on success.
+ *
+ * The input and output sizes are updated to the actual amounts of data consumed
+ * or written, not the amount available (as in a z_stream). The data pointers
+ * are not changed, so the next input is (data+input_size) and the next
+ * available output is (output+output_size).
+ */
+static int
+png_inflate(png_structrp png_ptr, png_uint_32 owner, int finish,
+ /* INPUT: */ png_const_bytep input, png_uint_32p input_size_ptr,
+ /* OUTPUT: */ png_bytep output, png_alloc_size_t *output_size_ptr)
+{
+ if (png_ptr->zowner == owner) /* Else not claimed */
+ {
+ int ret;
+ png_alloc_size_t avail_out = *output_size_ptr;
+ png_uint_32 avail_in = *input_size_ptr;
+
+ /* zlib can't necessarily handle more than 65535 bytes at once (i.e. it
+ * can't even necessarily handle 65536 bytes) because the type uInt is
+ * "16 bits or more". Consequently it is necessary to chunk the input to
+ * zlib. This code uses ZLIB_IO_MAX, from pngpriv.h, as the maximum (the
+ * maximum value that can be stored in a uInt.) It is possible to set
+ * ZLIB_IO_MAX to a lower value in pngpriv.h and this may sometimes have
+ * a performance advantage, because it reduces the amount of data accessed
+ * at each step and that may give the OS more time to page it in.
+ */
+ png_ptr->zstream.next_in = PNGZ_INPUT_CAST(input);
+ /* avail_in and avail_out are set below from 'size' */
+ png_ptr->zstream.avail_in = 0;
+ png_ptr->zstream.avail_out = 0;
+
+ /* Read directly into the output if it is available (this is set to
+ * a local buffer below if output is NULL).
+ */
+ if (output != NULL)
+ png_ptr->zstream.next_out = output;
+
+ do
+ {
+ uInt avail;
+ Byte local_buffer[PNG_INFLATE_BUF_SIZE];
+
+ /* zlib INPUT BUFFER */
+ /* The setting of 'avail_in' used to be outside the loop; by setting it
+ * inside it is possible to chunk the input to zlib and simply rely on
+ * zlib to advance the 'next_in' pointer. This allows arbitrary
+ * amounts of data to be passed through zlib at the unavoidable cost of
+ * requiring a window save (memcpy of up to 32768 output bytes)
+ * every ZLIB_IO_MAX input bytes.
+ */
+ avail_in += png_ptr->zstream.avail_in; /* not consumed last time */
+
+ avail = ZLIB_IO_MAX;
+
+ if (avail_in < avail)
+ avail = (uInt)avail_in; /* safe: < than ZLIB_IO_MAX */
+
+ avail_in -= avail;
+ png_ptr->zstream.avail_in = avail;
+
+ /* zlib OUTPUT BUFFER */
+ avail_out += png_ptr->zstream.avail_out; /* not written last time */
+
+ avail = ZLIB_IO_MAX; /* maximum zlib can process */
+
+ if (output == NULL)
+ {
+ /* Reset the output buffer each time round if output is NULL and
+ * make available the full buffer, up to 'remaining_space'
+ */
+ png_ptr->zstream.next_out = local_buffer;
+ if ((sizeof local_buffer) < avail)
+ avail = (sizeof local_buffer);
+ }
+
+ if (avail_out < avail)
+ avail = (uInt)avail_out; /* safe: < ZLIB_IO_MAX */
+
+ png_ptr->zstream.avail_out = avail;
+ avail_out -= avail;
+
+ /* zlib inflate call */
+ /* In fact 'avail_out' may be 0 at this point, that happens at the end
+ * of the read when the final LZ end code was not passed at the end of
+ * the previous chunk of input data. Tell zlib if we have reached the
+ * end of the output buffer.
+ */
+ ret = PNG_INFLATE(png_ptr, avail_out > 0 ? Z_NO_FLUSH :
+ (finish ? Z_FINISH : Z_SYNC_FLUSH));
+ } while (ret == Z_OK);
+
+ /* For safety kill the local buffer pointer now */
+ if (output == NULL)
+ png_ptr->zstream.next_out = NULL;
+
+ /* Claw back the 'size' and 'remaining_space' byte counts. */
+ avail_in += png_ptr->zstream.avail_in;
+ avail_out += png_ptr->zstream.avail_out;
+
+ /* Update the input and output sizes; the updated values are the amount
+ * consumed or written, effectively the inverse of what zlib uses.
+ */
+ if (avail_out > 0)
+ *output_size_ptr -= avail_out;
+
+ if (avail_in > 0)
+ *input_size_ptr -= avail_in;
+
+ /* Ensure png_ptr->zstream.msg is set (even in the success case!) */
+ png_zstream_error(png_ptr, ret);
+ return ret;
+ }
+
+ else
+ {
+ /* This is a bad internal error. The recovery assigns to the zstream msg
+ * pointer, which is not owned by the caller, but this is safe; it's only
+ * used on errors!
+ */
+ png_ptr->zstream.msg = PNGZ_MSG_CAST("zstream unclaimed");
+ return Z_STREAM_ERROR;
+ }
+}
+
+/*
+ * Decompress trailing data in a chunk. The assumption is that read_buffer
+ * points at an allocated area holding the contents of a chunk with a
+ * trailing compressed part. What we get back is an allocated area
+ * holding the original prefix part and an uncompressed version of the
+ * trailing part (the malloc area passed in is freed).
+ */
+static int
+png_decompress_chunk(png_structrp png_ptr,
+ png_uint_32 chunklength, png_uint_32 prefix_size,
+ png_alloc_size_t *newlength /* must be initialized to the maximum! */,
+ int terminate /*add a '\0' to the end of the uncompressed data*/)
+{
+ /* TODO: implement different limits for different types of chunk.
+ *
+ * The caller supplies *newlength set to the maximum length of the
+ * uncompressed data, but this routine allocates space for the prefix and
+ * maybe a '\0' terminator too. We have to assume that 'prefix_size' is
+ * limited only by the maximum chunk size.
+ */
+ png_alloc_size_t limit = PNG_SIZE_MAX;
+
+# ifdef PNG_SET_USER_LIMITS_SUPPORTED
+ if (png_ptr->user_chunk_malloc_max > 0 &&
+ png_ptr->user_chunk_malloc_max < limit)
+ limit = png_ptr->user_chunk_malloc_max;
+# elif PNG_USER_CHUNK_MALLOC_MAX > 0
+ if (PNG_USER_CHUNK_MALLOC_MAX < limit)
+ limit = PNG_USER_CHUNK_MALLOC_MAX;
+# endif
+
+ if (limit >= prefix_size + (terminate != 0))
+ {
+ int ret;
+
+ limit -= prefix_size + (terminate != 0);
+
+ if (limit < *newlength)
+ *newlength = limit;
+
+ /* Now try to claim the stream. */
+ ret = png_inflate_claim(png_ptr, png_ptr->chunk_name);
+
+ if (ret == Z_OK)
+ {
+ png_uint_32 lzsize = chunklength - prefix_size;
+
+ ret = png_inflate(png_ptr, png_ptr->chunk_name, 1/*finish*/,
+ /* input: */ png_ptr->read_buffer + prefix_size, &lzsize,
+ /* output: */ NULL, newlength);
+
+ if (ret == Z_STREAM_END)
+ {
+ /* Use 'inflateReset' here, not 'inflateReset2' because this
+ * preserves the previously decided window size (otherwise it would
+ * be necessary to store the previous window size.) In practice
+ * this doesn't matter anyway, because png_inflate will call inflate
+ * with Z_FINISH in almost all cases, so the window will not be
+ * maintained.
+ */
+ if (inflateReset(&png_ptr->zstream) == Z_OK)
+ {
+ /* Because of the limit checks above we know that the new,
+ * expanded, size will fit in a size_t (let alone an
+ * png_alloc_size_t). Use png_malloc_base here to avoid an
+ * extra OOM message.
+ */
+ png_alloc_size_t new_size = *newlength;
+ png_alloc_size_t buffer_size = prefix_size + new_size +
+ (terminate != 0);
+ png_bytep text = png_voidcast(png_bytep, png_malloc_base(png_ptr,
+ buffer_size));
+
+ if (text != NULL)
+ {
+ ret = png_inflate(png_ptr, png_ptr->chunk_name, 1/*finish*/,
+ png_ptr->read_buffer + prefix_size, &lzsize,
+ text + prefix_size, newlength);
+
+ if (ret == Z_STREAM_END)
+ {
+ if (new_size == *newlength)
+ {
+ if (terminate != 0)
+ text[prefix_size + *newlength] = 0;
+
+ if (prefix_size > 0)
+ memcpy(text, png_ptr->read_buffer, prefix_size);
+
+ {
+ png_bytep old_ptr = png_ptr->read_buffer;
+
+ png_ptr->read_buffer = text;
+ png_ptr->read_buffer_size = buffer_size;
+ text = old_ptr; /* freed below */
+ }
+ }
+
+ else
+ {
+ /* The size changed on the second read, there can be no
+ * guarantee that anything is correct at this point.
+ * The 'msg' pointer has been set to "unexpected end of
+ * LZ stream", which is fine, but return an error code
+ * that the caller won't accept.
+ */
+ ret = PNG_UNEXPECTED_ZLIB_RETURN;
+ }
+ }
+
+ else if (ret == Z_OK)
+ ret = PNG_UNEXPECTED_ZLIB_RETURN; /* for safety */
+
+ /* Free the text pointer (this is the old read_buffer on
+ * success)
+ */
+ png_free(png_ptr, text);
+
+ /* This really is very benign, but it's still an error because
+ * the extra space may otherwise be used as a Trojan Horse.
+ */
+ if (ret == Z_STREAM_END &&
+ chunklength - prefix_size != lzsize)
+ png_chunk_benign_error(png_ptr, "extra compressed data");
+ }
+
+ else
+ {
+ /* Out of memory allocating the buffer */
+ ret = Z_MEM_ERROR;
+ png_zstream_error(png_ptr, Z_MEM_ERROR);
+ }
+ }
+
+ else
+ {
+ /* inflateReset failed, store the error message */
+ png_zstream_error(png_ptr, ret);
+
+ if (ret == Z_STREAM_END)
+ ret = PNG_UNEXPECTED_ZLIB_RETURN;
+ }
+ }
+
+ else if (ret == Z_OK)
+ ret = PNG_UNEXPECTED_ZLIB_RETURN;
+
+ /* Release the claimed stream */
+ png_ptr->zowner = 0;
+ }
+
+ else /* the claim failed */ if (ret == Z_STREAM_END) /* impossible! */
+ ret = PNG_UNEXPECTED_ZLIB_RETURN;
+
+ return ret;
+ }
+
+ else
+ {
+ /* Application/configuration limits exceeded */
+ png_zstream_error(png_ptr, Z_MEM_ERROR);
+ return Z_MEM_ERROR;
+ }
+}
+#endif /* READ_COMPRESSED_TEXT */
+
+#ifdef PNG_READ_iCCP_SUPPORTED
+/* Perform a partial read and decompress, producing 'avail_out' bytes and
+ * reading from the current chunk as required.
+ */
+static int
+png_inflate_read(png_structrp png_ptr, png_bytep read_buffer, uInt read_size,
+ png_uint_32p chunk_bytes, png_bytep next_out, png_alloc_size_t *out_size,
+ int finish)
+{
+ if (png_ptr->zowner == png_ptr->chunk_name)
+ {
+ int ret;
+
+ /* next_in and avail_in must have been initialized by the caller. */
+ png_ptr->zstream.next_out = next_out;
+ png_ptr->zstream.avail_out = 0; /* set in the loop */
+
+ do
+ {
+ if (png_ptr->zstream.avail_in == 0)
+ {
+ if (read_size > *chunk_bytes)
+ read_size = (uInt)*chunk_bytes;
+ *chunk_bytes -= read_size;
+
+ if (read_size > 0)
+ png_crc_read(png_ptr, read_buffer, read_size);
+
+ png_ptr->zstream.next_in = read_buffer;
+ png_ptr->zstream.avail_in = read_size;
+ }
+
+ if (png_ptr->zstream.avail_out == 0)
+ {
+ uInt avail = ZLIB_IO_MAX;
+ if (avail > *out_size)
+ avail = (uInt)*out_size;
+ *out_size -= avail;
+
+ png_ptr->zstream.avail_out = avail;
+ }
+
+ /* Use Z_SYNC_FLUSH when there is no more chunk data to ensure that all
+ * the available output is produced; this allows reading of truncated
+ * streams.
+ */
+ ret = PNG_INFLATE(png_ptr,
+ *chunk_bytes > 0 ? Z_NO_FLUSH : (finish ? Z_FINISH : Z_SYNC_FLUSH));
+ }
+ while (ret == Z_OK && (*out_size > 0 || png_ptr->zstream.avail_out > 0));
+
+ *out_size += png_ptr->zstream.avail_out;
+ png_ptr->zstream.avail_out = 0; /* Should not be required, but is safe */
+
+ /* Ensure the error message pointer is always set: */
+ png_zstream_error(png_ptr, ret);
+ return ret;
+ }
+
+ else
+ {
+ png_ptr->zstream.msg = PNGZ_MSG_CAST("zstream unclaimed");
+ return Z_STREAM_ERROR;
+ }
+}
+#endif
+
+/* Read and check the IDHR chunk */
+
+void /* PRIVATE */
+png_handle_IHDR(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
+{
+ png_byte buf[13];
+ png_uint_32 width, height;
+ int bit_depth, color_type, compression_type, filter_type;
+ int interlace_type;
+
+ png_debug(1, "in png_handle_IHDR");
+
+ if ((png_ptr->mode & PNG_HAVE_IHDR) != 0)
+ png_chunk_error(png_ptr, "out of place");
+
+ /* Check the length */
+ if (length != 13)
+ png_chunk_error(png_ptr, "invalid");
+
+ png_ptr->mode |= PNG_HAVE_IHDR;
+
+ png_crc_read(png_ptr, buf, 13);
+ png_crc_finish(png_ptr, 0);
+
+ width = png_get_uint_31(png_ptr, buf);
+ height = png_get_uint_31(png_ptr, buf + 4);
+ bit_depth = buf[8];
+ color_type = buf[9];
+ compression_type = buf[10];
+ filter_type = buf[11];
+ interlace_type = buf[12];
+
+ /* Set internal variables */
+ png_ptr->width = width;
+ png_ptr->height = height;
+ png_ptr->bit_depth = (png_byte)bit_depth;
+ png_ptr->interlaced = (png_byte)interlace_type;
+ png_ptr->color_type = (png_byte)color_type;
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+ png_ptr->filter_type = (png_byte)filter_type;
+#endif
+ png_ptr->compression_type = (png_byte)compression_type;
+
+ /* Find number of channels */
+ switch (png_ptr->color_type)
+ {
+ default: /* invalid, png_set_IHDR calls png_error */
+ case PNG_COLOR_TYPE_GRAY:
+ case PNG_COLOR_TYPE_PALETTE:
+ png_ptr->channels = 1;
+ break;
+
+ case PNG_COLOR_TYPE_RGB:
+ png_ptr->channels = 3;
+ break;
+
+ case PNG_COLOR_TYPE_GRAY_ALPHA:
+ png_ptr->channels = 2;
+ break;
+
+ case PNG_COLOR_TYPE_RGB_ALPHA:
+ png_ptr->channels = 4;
+ break;
+ }
+
+ /* Set up other useful info */
+ png_ptr->pixel_depth = (png_byte)(png_ptr->bit_depth * png_ptr->channels);
+ png_ptr->rowbytes = PNG_ROWBYTES(png_ptr->pixel_depth, png_ptr->width);
+ png_debug1(3, "bit_depth = %d", png_ptr->bit_depth);
+ png_debug1(3, "channels = %d", png_ptr->channels);
+ png_debug1(3, "rowbytes = %lu", (unsigned long)png_ptr->rowbytes);
+ png_set_IHDR(png_ptr, info_ptr, width, height, bit_depth,
+ color_type, interlace_type, compression_type, filter_type);
+}
+
+/* Read and check the palette */
+void /* PRIVATE */
+png_handle_PLTE(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
+{
+ png_color palette[PNG_MAX_PALETTE_LENGTH];
+ int max_palette_length, num, i;
+#ifdef PNG_POINTER_INDEXING_SUPPORTED
+ png_colorp pal_ptr;
+#endif
+
+ png_debug(1, "in png_handle_PLTE");
+
+ if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
+ png_chunk_error(png_ptr, "missing IHDR");
+
+ /* Moved to before the 'after IDAT' check below because otherwise duplicate
+ * PLTE chunks are potentially ignored (the spec says there shall not be more
+ * than one PLTE, the error is not treated as benign, so this check trumps
+ * the requirement that PLTE appears before IDAT.)
+ */
+ else if ((png_ptr->mode & PNG_HAVE_PLTE) != 0)
+ png_chunk_error(png_ptr, "duplicate");
+
+ else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0)
+ {
+ /* This is benign because the non-benign error happened before, when an
+ * IDAT was encountered in a color-mapped image with no PLTE.
+ */
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "out of place");
+ return;
+ }
+
+ png_ptr->mode |= PNG_HAVE_PLTE;
+
+ if ((png_ptr->color_type & PNG_COLOR_MASK_COLOR) == 0)
+ {
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "ignored in grayscale PNG");
+ return;
+ }
+
+#ifndef PNG_READ_OPT_PLTE_SUPPORTED
+ if (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE)
+ {
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+#endif
+
+ if (length > 3*PNG_MAX_PALETTE_LENGTH || length % 3)
+ {
+ png_crc_finish(png_ptr, length);
+
+ if (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE)
+ png_chunk_benign_error(png_ptr, "invalid");
+
+ else
+ png_chunk_error(png_ptr, "invalid");
+
+ return;
+ }
+
+ /* The cast is safe because 'length' is less than 3*PNG_MAX_PALETTE_LENGTH */
+ num = (int)length / 3;
+
+ /* If the palette has 256 or fewer entries but is too large for the bit
+ * depth, we don't issue an error, to preserve the behavior of previous
+ * libpng versions. We silently truncate the unused extra palette entries
+ * here.
+ */
+ if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+ max_palette_length = (1 << png_ptr->bit_depth);
+ else
+ max_palette_length = PNG_MAX_PALETTE_LENGTH;
+
+ if (num > max_palette_length)
+ num = max_palette_length;
+
+#ifdef PNG_POINTER_INDEXING_SUPPORTED
+ for (i = 0, pal_ptr = palette; i < num; i++, pal_ptr++)
+ {
+ png_byte buf[3];
+
+ png_crc_read(png_ptr, buf, 3);
+ pal_ptr->red = buf[0];
+ pal_ptr->green = buf[1];
+ pal_ptr->blue = buf[2];
+ }
+#else
+ for (i = 0; i < num; i++)
+ {
+ png_byte buf[3];
+
+ png_crc_read(png_ptr, buf, 3);
+ /* Don't depend upon png_color being any order */
+ palette[i].red = buf[0];
+ palette[i].green = buf[1];
+ palette[i].blue = buf[2];
+ }
+#endif
+
+ /* If we actually need the PLTE chunk (ie for a paletted image), we do
+ * whatever the normal CRC configuration tells us. However, if we
+ * have an RGB image, the PLTE can be considered ancillary, so
+ * we will act as though it is.
+ */
+#ifndef PNG_READ_OPT_PLTE_SUPPORTED
+ if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+#endif
+ {
+ png_crc_finish(png_ptr, (int) length - num * 3);
+ }
+
+#ifndef PNG_READ_OPT_PLTE_SUPPORTED
+ else if (png_crc_error(png_ptr) != 0) /* Only if we have a CRC error */
+ {
+ /* If we don't want to use the data from an ancillary chunk,
+ * we have two options: an error abort, or a warning and we
+ * ignore the data in this chunk (which should be OK, since
+ * it's considered ancillary for a RGB or RGBA image).
+ *
+ * IMPLEMENTATION NOTE: this is only here because png_crc_finish uses the
+ * chunk type to determine whether to check the ancillary or the critical
+ * flags.
+ */
+ if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_USE) == 0)
+ {
+ if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN) != 0)
+ return;
+
+ else
+ png_chunk_error(png_ptr, "CRC error");
+ }
+
+ /* Otherwise, we (optionally) emit a warning and use the chunk. */
+ else if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN) == 0)
+ png_chunk_warning(png_ptr, "CRC error");
+ }
+#endif
+
+ /* TODO: png_set_PLTE has the side effect of setting png_ptr->palette to its
+ * own copy of the palette. This has the side effect that when png_start_row
+ * is called (this happens after any call to png_read_update_info) the
+ * info_ptr palette gets changed. This is extremely unexpected and
+ * confusing.
+ *
+ * Fix this by not sharing the palette in this way.
+ */
+ png_set_PLTE(png_ptr, info_ptr, palette, num);
+
+ /* The three chunks, bKGD, hIST and tRNS *must* appear after PLTE and before
+ * IDAT. Prior to 1.6.0 this was not checked; instead the code merely
+ * checked the apparent validity of a tRNS chunk inserted before PLTE on a
+ * palette PNG. 1.6.0 attempts to rigorously follow the standard and
+ * therefore does a benign error if the erroneous condition is detected *and*
+ * cancels the tRNS if the benign error returns. The alternative is to
+ * amend the standard since it would be rather hypocritical of the standards
+ * maintainers to ignore it.
+ */
+#ifdef PNG_READ_tRNS_SUPPORTED
+ if (png_ptr->num_trans > 0 ||
+ (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tRNS) != 0))
+ {
+ /* Cancel this because otherwise it would be used if the transforms
+ * require it. Don't cancel the 'valid' flag because this would prevent
+ * detection of duplicate chunks.
+ */
+ png_ptr->num_trans = 0;
+
+ if (info_ptr != NULL)
+ info_ptr->num_trans = 0;
+
+ png_chunk_benign_error(png_ptr, "tRNS must be after");
+ }
+#endif
+
+#ifdef PNG_READ_hIST_SUPPORTED
+ if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_hIST) != 0)
+ png_chunk_benign_error(png_ptr, "hIST must be after");
+#endif
+
+#ifdef PNG_READ_bKGD_SUPPORTED
+ if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_bKGD) != 0)
+ png_chunk_benign_error(png_ptr, "bKGD must be after");
+#endif
+}
+
+void /* PRIVATE */
+png_handle_IEND(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
+{
+ png_debug(1, "in png_handle_IEND");
+
+ if ((png_ptr->mode & PNG_HAVE_IHDR) == 0 ||
+ (png_ptr->mode & PNG_HAVE_IDAT) == 0)
+ png_chunk_error(png_ptr, "out of place");
+
+ png_ptr->mode |= (PNG_AFTER_IDAT | PNG_HAVE_IEND);
+
+ png_crc_finish(png_ptr, length);
+
+ if (length != 0)
+ png_chunk_benign_error(png_ptr, "invalid");
+
+ PNG_UNUSED(info_ptr)
+}
+
+#ifdef PNG_READ_gAMA_SUPPORTED
+void /* PRIVATE */
+png_handle_gAMA(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
+{
+ png_fixed_point igamma;
+ png_byte buf[4];
+
+ png_debug(1, "in png_handle_gAMA");
+
+ if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
+ png_chunk_error(png_ptr, "missing IHDR");
+
+ else if ((png_ptr->mode & (PNG_HAVE_IDAT|PNG_HAVE_PLTE)) != 0)
+ {
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "out of place");
+ return;
+ }
+
+ if (length != 4)
+ {
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "invalid");
+ return;
+ }
+
+ png_crc_read(png_ptr, buf, 4);
+
+ if (png_crc_finish(png_ptr, 0) != 0)
+ return;
+
+ igamma = png_get_fixed_point(NULL, buf);
+
+ png_colorspace_set_gamma(png_ptr, &png_ptr->colorspace, igamma);
+ png_colorspace_sync(png_ptr, info_ptr);
+}
+#endif
+
+#ifdef PNG_READ_sBIT_SUPPORTED
+void /* PRIVATE */
+png_handle_sBIT(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
+{
+ unsigned int truelen, i;
+ png_byte sample_depth;
+ png_byte buf[4];
+
+ png_debug(1, "in png_handle_sBIT");
+
+ if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
+ png_chunk_error(png_ptr, "missing IHDR");
+
+ else if ((png_ptr->mode & (PNG_HAVE_IDAT|PNG_HAVE_PLTE)) != 0)
+ {
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "out of place");
+ return;
+ }
+
+ if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sBIT) != 0)
+ {
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "duplicate");
+ return;
+ }
+
+ if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+ {
+ truelen = 3;
+ sample_depth = 8;
+ }
+
+ else
+ {
+ truelen = png_ptr->channels;
+ sample_depth = png_ptr->bit_depth;
+ }
+
+ if (length != truelen || length > 4)
+ {
+ png_chunk_benign_error(png_ptr, "invalid");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ buf[0] = buf[1] = buf[2] = buf[3] = sample_depth;
+ png_crc_read(png_ptr, buf, truelen);
+
+ if (png_crc_finish(png_ptr, 0) != 0)
+ return;
+
+ for (i=0; i<truelen; ++i)
+ {
+ if (buf[i] == 0 || buf[i] > sample_depth)
+ {
+ png_chunk_benign_error(png_ptr, "invalid");
+ return;
+ }
+ }
+
+ if ((png_ptr->color_type & PNG_COLOR_MASK_COLOR) != 0)
+ {
+ png_ptr->sig_bit.red = buf[0];
+ png_ptr->sig_bit.green = buf[1];
+ png_ptr->sig_bit.blue = buf[2];
+ png_ptr->sig_bit.alpha = buf[3];
+ }
+
+ else
+ {
+ png_ptr->sig_bit.gray = buf[0];
+ png_ptr->sig_bit.red = buf[0];
+ png_ptr->sig_bit.green = buf[0];
+ png_ptr->sig_bit.blue = buf[0];
+ png_ptr->sig_bit.alpha = buf[1];
+ }
+
+ png_set_sBIT(png_ptr, info_ptr, &(png_ptr->sig_bit));
+}
+#endif
+
+#ifdef PNG_READ_cHRM_SUPPORTED
+void /* PRIVATE */
+png_handle_cHRM(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
+{
+ png_byte buf[32];
+ png_xy xy;
+
+ png_debug(1, "in png_handle_cHRM");
+
+ if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
+ png_chunk_error(png_ptr, "missing IHDR");
+
+ else if ((png_ptr->mode & (PNG_HAVE_IDAT|PNG_HAVE_PLTE)) != 0)
+ {
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "out of place");
+ return;
+ }
+
+ if (length != 32)
+ {
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "invalid");
+ return;
+ }
+
+ png_crc_read(png_ptr, buf, 32);
+
+ if (png_crc_finish(png_ptr, 0) != 0)
+ return;
+
+ xy.whitex = png_get_fixed_point(NULL, buf);
+ xy.whitey = png_get_fixed_point(NULL, buf + 4);
+ xy.redx = png_get_fixed_point(NULL, buf + 8);
+ xy.redy = png_get_fixed_point(NULL, buf + 12);
+ xy.greenx = png_get_fixed_point(NULL, buf + 16);
+ xy.greeny = png_get_fixed_point(NULL, buf + 20);
+ xy.bluex = png_get_fixed_point(NULL, buf + 24);
+ xy.bluey = png_get_fixed_point(NULL, buf + 28);
+
+ if (xy.whitex == PNG_FIXED_ERROR ||
+ xy.whitey == PNG_FIXED_ERROR ||
+ xy.redx == PNG_FIXED_ERROR ||
+ xy.redy == PNG_FIXED_ERROR ||
+ xy.greenx == PNG_FIXED_ERROR ||
+ xy.greeny == PNG_FIXED_ERROR ||
+ xy.bluex == PNG_FIXED_ERROR ||
+ xy.bluey == PNG_FIXED_ERROR)
+ {
+ png_chunk_benign_error(png_ptr, "invalid values");
+ return;
+ }
+
+ /* If a colorspace error has already been output skip this chunk */
+ if ((png_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) != 0)
+ return;
+
+ if ((png_ptr->colorspace.flags & PNG_COLORSPACE_FROM_cHRM) != 0)
+ {
+ png_ptr->colorspace.flags |= PNG_COLORSPACE_INVALID;
+ png_colorspace_sync(png_ptr, info_ptr);
+ png_chunk_benign_error(png_ptr, "duplicate");
+ return;
+ }
+
+ png_ptr->colorspace.flags |= PNG_COLORSPACE_FROM_cHRM;
+ (void)png_colorspace_set_chromaticities(png_ptr, &png_ptr->colorspace, &xy,
+ 1/*prefer cHRM values*/);
+ png_colorspace_sync(png_ptr, info_ptr);
+}
+#endif
+
+#ifdef PNG_READ_sRGB_SUPPORTED
+void /* PRIVATE */
+png_handle_sRGB(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
+{
+ png_byte intent;
+
+ png_debug(1, "in png_handle_sRGB");
+
+ if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
+ png_chunk_error(png_ptr, "missing IHDR");
+
+ else if ((png_ptr->mode & (PNG_HAVE_IDAT|PNG_HAVE_PLTE)) != 0)
+ {
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "out of place");
+ return;
+ }
+
+ if (length != 1)
+ {
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "invalid");
+ return;
+ }
+
+ png_crc_read(png_ptr, &intent, 1);
+
+ if (png_crc_finish(png_ptr, 0) != 0)
+ return;
+
+ /* If a colorspace error has already been output skip this chunk */
+ if ((png_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) != 0)
+ return;
+
+ /* Only one sRGB or iCCP chunk is allowed, use the HAVE_INTENT flag to detect
+ * this.
+ */
+ if ((png_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_INTENT) != 0)
+ {
+ png_ptr->colorspace.flags |= PNG_COLORSPACE_INVALID;
+ png_colorspace_sync(png_ptr, info_ptr);
+ png_chunk_benign_error(png_ptr, "too many profiles");
+ return;
+ }
+
+ (void)png_colorspace_set_sRGB(png_ptr, &png_ptr->colorspace, intent);
+ png_colorspace_sync(png_ptr, info_ptr);
+}
+#endif /* READ_sRGB */
+
+#ifdef PNG_READ_iCCP_SUPPORTED
+void /* PRIVATE */
+png_handle_iCCP(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
+/* Note: this does not properly handle profiles that are > 64K under DOS */
+{
+ png_const_charp errmsg = NULL; /* error message output, or no error */
+ int finished = 0; /* crc checked */
+
+ png_debug(1, "in png_handle_iCCP");
+
+ if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
+ png_chunk_error(png_ptr, "missing IHDR");
+
+ else if ((png_ptr->mode & (PNG_HAVE_IDAT|PNG_HAVE_PLTE)) != 0)
+ {
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "out of place");
+ return;
+ }
+
+ /* Consistent with all the above colorspace handling an obviously *invalid*
+ * chunk is just ignored, so does not invalidate the color space. An
+ * alternative is to set the 'invalid' flags at the start of this routine
+ * and only clear them in they were not set before and all the tests pass.
+ * The minimum 'deflate' stream is assumed to be just the 2 byte header and
+ * 4 byte checksum. The keyword must be at least one character and there is
+ * a terminator (0) byte and the compression method.
+ */
+ if (length < 9)
+ {
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "too short");
+ return;
+ }
+
+ /* If a colorspace error has already been output skip this chunk */
+ if ((png_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) != 0)
+ {
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ /* Only one sRGB or iCCP chunk is allowed, use the HAVE_INTENT flag to detect
+ * this.
+ */
+ if ((png_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_INTENT) == 0)
+ {
+ uInt read_length, keyword_length;
+ char keyword[81];
+
+ /* Find the keyword; the keyword plus separator and compression method
+ * bytes can be at most 81 characters long.
+ */
+ read_length = 81; /* maximum */
+ if (read_length > length)
+ read_length = (uInt)length;
+
+ png_crc_read(png_ptr, (png_bytep)keyword, read_length);
+ length -= read_length;
+
+ keyword_length = 0;
+ while (keyword_length < 80 && keyword_length < read_length &&
+ keyword[keyword_length] != 0)
+ ++keyword_length;
+
+ /* TODO: make the keyword checking common */
+ if (keyword_length >= 1 && keyword_length <= 79)
+ {
+ /* We only understand '0' compression - deflate - so if we get a
+ * different value we can't safely decode the chunk.
+ */
+ if (keyword_length+1 < read_length &&
+ keyword[keyword_length+1] == PNG_COMPRESSION_TYPE_BASE)
+ {
+ read_length -= keyword_length+2;
+
+ if (png_inflate_claim(png_ptr, png_iCCP) == Z_OK)
+ {
+ Byte profile_header[132];
+ Byte local_buffer[PNG_INFLATE_BUF_SIZE];
+ png_alloc_size_t size = (sizeof profile_header);
+
+ png_ptr->zstream.next_in = (Bytef*)keyword + (keyword_length+2);
+ png_ptr->zstream.avail_in = read_length;
+ (void)png_inflate_read(png_ptr, local_buffer,
+ (sizeof local_buffer), &length, profile_header, &size,
+ 0/*finish: don't, because the output is too small*/);
+
+ if (size == 0)
+ {
+ /* We have the ICC profile header; do the basic header checks.
+ */
+ const png_uint_32 profile_length =
+ png_get_uint_32(profile_header);
+
+ if (png_icc_check_length(png_ptr, &png_ptr->colorspace,
+ keyword, profile_length) != 0)
+ {
+ /* The length is apparently ok, so we can check the 132
+ * byte header.
+ */
+ if (png_icc_check_header(png_ptr, &png_ptr->colorspace,
+ keyword, profile_length, profile_header,
+ png_ptr->color_type) != 0)
+ {
+ /* Now read the tag table; a variable size buffer is
+ * needed at this point, allocate one for the whole
+ * profile. The header check has already validated
+ * that none of these stuff will overflow.
+ */
+ const png_uint_32 tag_count = png_get_uint_32(
+ profile_header+128);
+ png_bytep profile = png_read_buffer(png_ptr,
+ profile_length, 2/*silent*/);
+
+ if (profile != NULL)
+ {
+ memcpy(profile, profile_header,
+ (sizeof profile_header));
+
+ size = 12 * tag_count;
+
+ (void)png_inflate_read(png_ptr, local_buffer,
+ (sizeof local_buffer), &length,
+ profile + (sizeof profile_header), &size, 0);
+
+ /* Still expect a buffer error because we expect
+ * there to be some tag data!
+ */
+ if (size == 0)
+ {
+ if (png_icc_check_tag_table(png_ptr,
+ &png_ptr->colorspace, keyword, profile_length,
+ profile) != 0)
+ {
+ /* The profile has been validated for basic
+ * security issues, so read the whole thing in.
+ */
+ size = profile_length - (sizeof profile_header)
+ - 12 * tag_count;
+
+ (void)png_inflate_read(png_ptr, local_buffer,
+ (sizeof local_buffer), &length,
+ profile + (sizeof profile_header) +
+ 12 * tag_count, &size, 1/*finish*/);
+
+ if (length > 0 && !(png_ptr->flags &
+ PNG_FLAG_BENIGN_ERRORS_WARN))
+ errmsg = "extra compressed data";
+
+ /* But otherwise allow extra data: */
+ else if (size == 0)
+ {
+ if (length > 0)
+ {
+ /* This can be handled completely, so
+ * keep going.
+ */
+ png_chunk_warning(png_ptr,
+ "extra compressed data");
+ }
+
+ png_crc_finish(png_ptr, length);
+ finished = 1;
+
+# ifdef PNG_sRGB_SUPPORTED
+ /* Check for a match against sRGB */
+ png_icc_set_sRGB(png_ptr,
+ &png_ptr->colorspace, profile,
+ png_ptr->zstream.adler);
+# endif
+
+ /* Steal the profile for info_ptr. */
+ if (info_ptr != NULL)
+ {
+ png_free_data(png_ptr, info_ptr,
+ PNG_FREE_ICCP, 0);
+
+ info_ptr->iccp_name = png_voidcast(char*,
+ png_malloc_base(png_ptr,
+ keyword_length+1));
+ if (info_ptr->iccp_name != NULL)
+ {
+ memcpy(info_ptr->iccp_name, keyword,
+ keyword_length+1);
+ info_ptr->iccp_proflen =
+ profile_length;
+ info_ptr->iccp_profile = profile;
+ png_ptr->read_buffer = NULL; /*steal*/
+ info_ptr->free_me |= PNG_FREE_ICCP;
+ info_ptr->valid |= PNG_INFO_iCCP;
+ }
+
+ else
+ {
+ png_ptr->colorspace.flags |=
+ PNG_COLORSPACE_INVALID;
+ errmsg = "out of memory";
+ }
+ }
+
+ /* else the profile remains in the read
+ * buffer which gets reused for subsequent
+ * chunks.
+ */
+
+ if (info_ptr != NULL)
+ png_colorspace_sync(png_ptr, info_ptr);
+
+ if (errmsg == NULL)
+ {
+ png_ptr->zowner = 0;
+ return;
+ }
+ }
+
+ else if (size > 0)
+ errmsg = "truncated";
+
+#ifndef __COVERITY__
+ else
+ errmsg = png_ptr->zstream.msg;
+#endif
+ }
+
+ /* else png_icc_check_tag_table output an error */
+ }
+
+ else /* profile truncated */
+ errmsg = png_ptr->zstream.msg;
+ }
+
+ else
+ errmsg = "out of memory";
+ }
+
+ /* else png_icc_check_header output an error */
+ }
+
+ /* else png_icc_check_length output an error */
+ }
+
+ else /* profile truncated */
+ errmsg = png_ptr->zstream.msg;
+
+ /* Release the stream */
+ png_ptr->zowner = 0;
+ }
+
+ else /* png_inflate_claim failed */
+ errmsg = png_ptr->zstream.msg;
+ }
+
+ else
+ errmsg = "bad compression method"; /* or missing */
+ }
+
+ else
+ errmsg = "bad keyword";
+ }
+
+ else
+ errmsg = "too many profiles";
+
+ /* Failure: the reason is in 'errmsg' */
+ if (finished == 0)
+ png_crc_finish(png_ptr, length);
+
+ png_ptr->colorspace.flags |= PNG_COLORSPACE_INVALID;
+ png_colorspace_sync(png_ptr, info_ptr);
+ if (errmsg != NULL) /* else already output */
+ png_chunk_benign_error(png_ptr, errmsg);
+}
+#endif /* READ_iCCP */
+
+#ifdef PNG_READ_sPLT_SUPPORTED
+void /* PRIVATE */
+png_handle_sPLT(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
+/* Note: this does not properly handle chunks that are > 64K under DOS */
+{
+ png_bytep entry_start, buffer;
+ png_sPLT_t new_palette;
+ png_sPLT_entryp pp;
+ png_uint_32 data_length;
+ int entry_size, i;
+ png_uint_32 skip = 0;
+ png_uint_32 dl;
+ png_size_t max_dl;
+
+ png_debug(1, "in png_handle_sPLT");
+
+#ifdef PNG_USER_LIMITS_SUPPORTED
+ if (png_ptr->user_chunk_cache_max != 0)
+ {
+ if (png_ptr->user_chunk_cache_max == 1)
+ {
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ if (--png_ptr->user_chunk_cache_max == 1)
+ {
+ png_warning(png_ptr, "No space in chunk cache for sPLT");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+ }
+#endif
+
+ if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
+ png_chunk_error(png_ptr, "missing IHDR");
+
+ else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0)
+ {
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "out of place");
+ return;
+ }
+
+#ifdef PNG_MAX_MALLOC_64K
+ if (length > 65535U)
+ {
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "too large to fit in memory");
+ return;
+ }
+#endif
+
+ buffer = png_read_buffer(png_ptr, length+1, 2/*silent*/);
+ if (buffer == NULL)
+ {
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "out of memory");
+ return;
+ }
+
+
+ /* WARNING: this may break if size_t is less than 32 bits; it is assumed
+ * that the PNG_MAX_MALLOC_64K test is enabled in this case, but this is a
+ * potential breakage point if the types in pngconf.h aren't exactly right.
+ */
+ png_crc_read(png_ptr, buffer, length);
+
+ if (png_crc_finish(png_ptr, skip) != 0)
+ return;
+
+ buffer[length] = 0;
+
+ for (entry_start = buffer; *entry_start; entry_start++)
+ /* Empty loop to find end of name */ ;
+
+ ++entry_start;
+
+ /* A sample depth should follow the separator, and we should be on it */
+ if (length < 2U || entry_start > buffer + (length - 2U))
+ {
+ png_warning(png_ptr, "malformed sPLT chunk");
+ return;
+ }
+
+ new_palette.depth = *entry_start++;
+ entry_size = (new_palette.depth == 8 ? 6 : 10);
+ /* This must fit in a png_uint_32 because it is derived from the original
+ * chunk data length.
+ */
+ data_length = length - (png_uint_32)(entry_start - buffer);
+
+ /* Integrity-check the data length */
+ if ((data_length % entry_size) != 0)
+ {
+ png_warning(png_ptr, "sPLT chunk has bad length");
+ return;
+ }
+
+ dl = (png_int_32)(data_length / entry_size);
+ max_dl = PNG_SIZE_MAX / (sizeof (png_sPLT_entry));
+
+ if (dl > max_dl)
+ {
+ png_warning(png_ptr, "sPLT chunk too long");
+ return;
+ }
+
+ new_palette.nentries = (png_int_32)(data_length / entry_size);
+
+ new_palette.entries = (png_sPLT_entryp)png_malloc_warn(
+ png_ptr, new_palette.nentries * (sizeof (png_sPLT_entry)));
+
+ if (new_palette.entries == NULL)
+ {
+ png_warning(png_ptr, "sPLT chunk requires too much memory");
+ return;
+ }
+
+#ifdef PNG_POINTER_INDEXING_SUPPORTED
+ for (i = 0; i < new_palette.nentries; i++)
+ {
+ pp = new_palette.entries + i;
+
+ if (new_palette.depth == 8)
+ {
+ pp->red = *entry_start++;
+ pp->green = *entry_start++;
+ pp->blue = *entry_start++;
+ pp->alpha = *entry_start++;
+ }
+
+ else
+ {
+ pp->red = png_get_uint_16(entry_start); entry_start += 2;
+ pp->green = png_get_uint_16(entry_start); entry_start += 2;
+ pp->blue = png_get_uint_16(entry_start); entry_start += 2;
+ pp->alpha = png_get_uint_16(entry_start); entry_start += 2;
+ }
+
+ pp->frequency = png_get_uint_16(entry_start); entry_start += 2;
+ }
+#else
+ pp = new_palette.entries;
+
+ for (i = 0; i < new_palette.nentries; i++)
+ {
+
+ if (new_palette.depth == 8)
+ {
+ pp[i].red = *entry_start++;
+ pp[i].green = *entry_start++;
+ pp[i].blue = *entry_start++;
+ pp[i].alpha = *entry_start++;
+ }
+
+ else
+ {
+ pp[i].red = png_get_uint_16(entry_start); entry_start += 2;
+ pp[i].green = png_get_uint_16(entry_start); entry_start += 2;
+ pp[i].blue = png_get_uint_16(entry_start); entry_start += 2;
+ pp[i].alpha = png_get_uint_16(entry_start); entry_start += 2;
+ }
+
+ pp[i].frequency = png_get_uint_16(entry_start); entry_start += 2;
+ }
+#endif
+
+ /* Discard all chunk data except the name and stash that */
+ new_palette.name = (png_charp)buffer;
+
+ png_set_sPLT(png_ptr, info_ptr, &new_palette, 1);
+
+ png_free(png_ptr, new_palette.entries);
+}
+#endif /* READ_sPLT */
+
+#ifdef PNG_READ_tRNS_SUPPORTED
+void /* PRIVATE */
+png_handle_tRNS(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
+{
+ png_byte readbuf[PNG_MAX_PALETTE_LENGTH];
+
+ png_debug(1, "in png_handle_tRNS");
+
+ if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
+ png_chunk_error(png_ptr, "missing IHDR");
+
+ else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0)
+ {
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "out of place");
+ return;
+ }
+
+ else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tRNS) != 0)
+ {
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "duplicate");
+ return;
+ }
+
+ if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY)
+ {
+ png_byte buf[2];
+
+ if (length != 2)
+ {
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "invalid");
+ return;
+ }
+
+ png_crc_read(png_ptr, buf, 2);
+ png_ptr->num_trans = 1;
+ png_ptr->trans_color.gray = png_get_uint_16(buf);
+ }
+
+ else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB)
+ {
+ png_byte buf[6];
+
+ if (length != 6)
+ {
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "invalid");
+ return;
+ }
+
+ png_crc_read(png_ptr, buf, length);
+ png_ptr->num_trans = 1;
+ png_ptr->trans_color.red = png_get_uint_16(buf);
+ png_ptr->trans_color.green = png_get_uint_16(buf + 2);
+ png_ptr->trans_color.blue = png_get_uint_16(buf + 4);
+ }
+
+ else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+ {
+ if ((png_ptr->mode & PNG_HAVE_PLTE) == 0)
+ {
+ /* TODO: is this actually an error in the ISO spec? */
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "out of place");
+ return;
+ }
+
+ if (length > (unsigned int) png_ptr->num_palette ||
+ length > (unsigned int) PNG_MAX_PALETTE_LENGTH ||
+ length == 0)
+ {
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "invalid");
+ return;
+ }
+
+ png_crc_read(png_ptr, readbuf, length);
+ png_ptr->num_trans = (png_uint_16)length;
+ }
+
+ else
+ {
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "invalid with alpha channel");
+ return;
+ }
+
+ if (png_crc_finish(png_ptr, 0) != 0)
+ {
+ png_ptr->num_trans = 0;
+ return;
+ }
+
+ /* TODO: this is a horrible side effect in the palette case because the
+ * png_struct ends up with a pointer to the tRNS buffer owned by the
+ * png_info. Fix this.
+ */
+ png_set_tRNS(png_ptr, info_ptr, readbuf, png_ptr->num_trans,
+ &(png_ptr->trans_color));
+}
+#endif
+
+#ifdef PNG_READ_bKGD_SUPPORTED
+void /* PRIVATE */
+png_handle_bKGD(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
+{
+ unsigned int truelen;
+ png_byte buf[6];
+ png_color_16 background;
+
+ png_debug(1, "in png_handle_bKGD");
+
+ if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
+ png_chunk_error(png_ptr, "missing IHDR");
+
+ else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0 ||
+ (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
+ (png_ptr->mode & PNG_HAVE_PLTE) == 0))
+ {
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "out of place");
+ return;
+ }
+
+ else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_bKGD) != 0)
+ {
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "duplicate");
+ return;
+ }
+
+ if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+ truelen = 1;
+
+ else if ((png_ptr->color_type & PNG_COLOR_MASK_COLOR) != 0)
+ truelen = 6;
+
+ else
+ truelen = 2;
+
+ if (length != truelen)
+ {
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "invalid");
+ return;
+ }
+
+ png_crc_read(png_ptr, buf, truelen);
+
+ if (png_crc_finish(png_ptr, 0) != 0)
+ return;
+
+ /* We convert the index value into RGB components so that we can allow
+ * arbitrary RGB values for background when we have transparency, and
+ * so it is easy to determine the RGB values of the background color
+ * from the info_ptr struct.
+ */
+ if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+ {
+ background.index = buf[0];
+
+ if (info_ptr != NULL && info_ptr->num_palette != 0)
+ {
+ if (buf[0] >= info_ptr->num_palette)
+ {
+ png_chunk_benign_error(png_ptr, "invalid index");
+ return;
+ }
+
+ background.red = (png_uint_16)png_ptr->palette[buf[0]].red;
+ background.green = (png_uint_16)png_ptr->palette[buf[0]].green;
+ background.blue = (png_uint_16)png_ptr->palette[buf[0]].blue;
+ }
+
+ else
+ background.red = background.green = background.blue = 0;
+
+ background.gray = 0;
+ }
+
+ else if ((png_ptr->color_type & PNG_COLOR_MASK_COLOR) == 0) /* GRAY */
+ {
+ background.index = 0;
+ background.red =
+ background.green =
+ background.blue =
+ background.gray = png_get_uint_16(buf);
+ }
+
+ else
+ {
+ background.index = 0;
+ background.red = png_get_uint_16(buf);
+ background.green = png_get_uint_16(buf + 2);
+ background.blue = png_get_uint_16(buf + 4);
+ background.gray = 0;
+ }
+
+ png_set_bKGD(png_ptr, info_ptr, &background);
+}
+#endif
+
+#ifdef PNG_READ_hIST_SUPPORTED
+void /* PRIVATE */
+png_handle_hIST(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
+{
+ unsigned int num, i;
+ png_uint_16 readbuf[PNG_MAX_PALETTE_LENGTH];
+
+ png_debug(1, "in png_handle_hIST");
+
+ if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
+ png_chunk_error(png_ptr, "missing IHDR");
+
+ else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0 ||
+ (png_ptr->mode & PNG_HAVE_PLTE) == 0)
+ {
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "out of place");
+ return;
+ }
+
+ else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_hIST) != 0)
+ {
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "duplicate");
+ return;
+ }
+
+ num = length / 2 ;
+
+ if (num != (unsigned int) png_ptr->num_palette ||
+ num > (unsigned int) PNG_MAX_PALETTE_LENGTH)
+ {
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "invalid");
+ return;
+ }
+
+ for (i = 0; i < num; i++)
+ {
+ png_byte buf[2];
+
+ png_crc_read(png_ptr, buf, 2);
+ readbuf[i] = png_get_uint_16(buf);
+ }
+
+ if (png_crc_finish(png_ptr, 0) != 0)
+ return;
+
+ png_set_hIST(png_ptr, info_ptr, readbuf);
+}
+#endif
+
+#ifdef PNG_READ_pHYs_SUPPORTED
+void /* PRIVATE */
+png_handle_pHYs(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
+{
+ png_byte buf[9];
+ png_uint_32 res_x, res_y;
+ int unit_type;
+
+ png_debug(1, "in png_handle_pHYs");
+
+ if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
+ png_chunk_error(png_ptr, "missing IHDR");
+
+ else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0)
+ {
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "out of place");
+ return;
+ }
+
+ else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs) != 0)
+ {
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "duplicate");
+ return;
+ }
+
+ if (length != 9)
+ {
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "invalid");
+ return;
+ }
+
+ png_crc_read(png_ptr, buf, 9);
+
+ if (png_crc_finish(png_ptr, 0) != 0)
+ return;
+
+ res_x = png_get_uint_32(buf);
+ res_y = png_get_uint_32(buf + 4);
+ unit_type = buf[8];
+ png_set_pHYs(png_ptr, info_ptr, res_x, res_y, unit_type);
+}
+#endif
+
+#ifdef PNG_READ_oFFs_SUPPORTED
+void /* PRIVATE */
+png_handle_oFFs(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
+{
+ png_byte buf[9];
+ png_int_32 offset_x, offset_y;
+ int unit_type;
+
+ png_debug(1, "in png_handle_oFFs");
+
+ if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
+ png_chunk_error(png_ptr, "missing IHDR");
+
+ else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0)
+ {
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "out of place");
+ return;
+ }
+
+ else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs) != 0)
+ {
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "duplicate");
+ return;
+ }
+
+ if (length != 9)
+ {
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "invalid");
+ return;
+ }
+
+ png_crc_read(png_ptr, buf, 9);
+
+ if (png_crc_finish(png_ptr, 0) != 0)
+ return;
+
+ offset_x = png_get_int_32(buf);
+ offset_y = png_get_int_32(buf + 4);
+ unit_type = buf[8];
+ png_set_oFFs(png_ptr, info_ptr, offset_x, offset_y, unit_type);
+}
+#endif
+
+#ifdef PNG_READ_pCAL_SUPPORTED
+/* Read the pCAL chunk (described in the PNG Extensions document) */
+void /* PRIVATE */
+png_handle_pCAL(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
+{
+ png_int_32 X0, X1;
+ png_byte type, nparams;
+ png_bytep buffer, buf, units, endptr;
+ png_charpp params;
+ int i;
+
+ png_debug(1, "in png_handle_pCAL");
+
+ if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
+ png_chunk_error(png_ptr, "missing IHDR");
+
+ else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0)
+ {
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "out of place");
+ return;
+ }
+
+ else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_pCAL) != 0)
+ {
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "duplicate");
+ return;
+ }
+
+ png_debug1(2, "Allocating and reading pCAL chunk data (%u bytes)",
+ length + 1);
+
+ buffer = png_read_buffer(png_ptr, length+1, 2/*silent*/);
+
+ if (buffer == NULL)
+ {
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "out of memory");
+ return;
+ }
+
+ png_crc_read(png_ptr, buffer, length);
+
+ if (png_crc_finish(png_ptr, 0) != 0)
+ return;
+
+ buffer[length] = 0; /* Null terminate the last string */
+
+ png_debug(3, "Finding end of pCAL purpose string");
+ for (buf = buffer; *buf; buf++)
+ /* Empty loop */ ;
+
+ endptr = buffer + length;
+
+ /* We need to have at least 12 bytes after the purpose string
+ * in order to get the parameter information.
+ */
+ if (endptr - buf <= 12)
+ {
+ png_chunk_benign_error(png_ptr, "invalid");
+ return;
+ }
+
+ png_debug(3, "Reading pCAL X0, X1, type, nparams, and units");
+ X0 = png_get_int_32((png_bytep)buf+1);
+ X1 = png_get_int_32((png_bytep)buf+5);
+ type = buf[9];
+ nparams = buf[10];
+ units = buf + 11;
+
+ png_debug(3, "Checking pCAL equation type and number of parameters");
+ /* Check that we have the right number of parameters for known
+ * equation types.
+ */
+ if ((type == PNG_EQUATION_LINEAR && nparams != 2) ||
+ (type == PNG_EQUATION_BASE_E && nparams != 3) ||
+ (type == PNG_EQUATION_ARBITRARY && nparams != 3) ||
+ (type == PNG_EQUATION_HYPERBOLIC && nparams != 4))
+ {
+ png_chunk_benign_error(png_ptr, "invalid parameter count");
+ return;
+ }
+
+ else if (type >= PNG_EQUATION_LAST)
+ {
+ png_chunk_benign_error(png_ptr, "unrecognized equation type");
+ }
+
+ for (buf = units; *buf; buf++)
+ /* Empty loop to move past the units string. */ ;
+
+ png_debug(3, "Allocating pCAL parameters array");
+
+ params = png_voidcast(png_charpp, png_malloc_warn(png_ptr,
+ nparams * (sizeof (png_charp))));
+
+ if (params == NULL)
+ {
+ png_chunk_benign_error(png_ptr, "out of memory");
+ return;
+ }
+
+ /* Get pointers to the start of each parameter string. */
+ for (i = 0; i < nparams; i++)
+ {
+ buf++; /* Skip the null string terminator from previous parameter. */
+
+ png_debug1(3, "Reading pCAL parameter %d", i);
+
+ for (params[i] = (png_charp)buf; buf <= endptr && *buf != 0; buf++)
+ /* Empty loop to move past each parameter string */ ;
+
+ /* Make sure we haven't run out of data yet */
+ if (buf > endptr)
+ {
+ png_free(png_ptr, params);
+ png_chunk_benign_error(png_ptr, "invalid data");
+ return;
+ }
+ }
+
+ png_set_pCAL(png_ptr, info_ptr, (png_charp)buffer, X0, X1, type, nparams,
+ (png_charp)units, params);
+
+ png_free(png_ptr, params);
+}
+#endif
+
+#ifdef PNG_READ_sCAL_SUPPORTED
+/* Read the sCAL chunk */
+void /* PRIVATE */
+png_handle_sCAL(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
+{
+ png_bytep buffer;
+ png_size_t i;
+ int state;
+
+ png_debug(1, "in png_handle_sCAL");
+
+ if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
+ png_chunk_error(png_ptr, "missing IHDR");
+
+ else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0)
+ {
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "out of place");
+ return;
+ }
+
+ else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sCAL) != 0)
+ {
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "duplicate");
+ return;
+ }
+
+ /* Need unit type, width, \0, height: minimum 4 bytes */
+ else if (length < 4)
+ {
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "invalid");
+ return;
+ }
+
+ png_debug1(2, "Allocating and reading sCAL chunk data (%u bytes)",
+ length + 1);
+
+ buffer = png_read_buffer(png_ptr, length+1, 2/*silent*/);
+
+ if (buffer == NULL)
+ {
+ png_chunk_benign_error(png_ptr, "out of memory");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ png_crc_read(png_ptr, buffer, length);
+ buffer[length] = 0; /* Null terminate the last string */
+
+ if (png_crc_finish(png_ptr, 0) != 0)
+ return;
+
+ /* Validate the unit. */
+ if (buffer[0] != 1 && buffer[0] != 2)
+ {
+ png_chunk_benign_error(png_ptr, "invalid unit");
+ return;
+ }
+
+ /* Validate the ASCII numbers, need two ASCII numbers separated by
+ * a '\0' and they need to fit exactly in the chunk data.
+ */
+ i = 1;
+ state = 0;
+
+ if (png_check_fp_number((png_const_charp)buffer, length, &state, &i) == 0 ||
+ i >= length || buffer[i++] != 0)
+ png_chunk_benign_error(png_ptr, "bad width format");
+
+ else if (PNG_FP_IS_POSITIVE(state) == 0)
+ png_chunk_benign_error(png_ptr, "non-positive width");
+
+ else
+ {
+ png_size_t heighti = i;
+
+ state = 0;
+ if (png_check_fp_number((png_const_charp)buffer, length,
+ &state, &i) == 0 || i != length)
+ png_chunk_benign_error(png_ptr, "bad height format");
+
+ else if (PNG_FP_IS_POSITIVE(state) == 0)
+ png_chunk_benign_error(png_ptr, "non-positive height");
+
+ else
+ /* This is the (only) success case. */
+ png_set_sCAL_s(png_ptr, info_ptr, buffer[0],
+ (png_charp)buffer+1, (png_charp)buffer+heighti);
+ }
+}
+#endif
+
+#ifdef PNG_READ_tIME_SUPPORTED
+void /* PRIVATE */
+png_handle_tIME(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
+{
+ png_byte buf[7];
+ png_time mod_time;
+
+ png_debug(1, "in png_handle_tIME");
+
+ if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
+ png_chunk_error(png_ptr, "missing IHDR");
+
+ else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tIME) != 0)
+ {
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "duplicate");
+ return;
+ }
+
+ if ((png_ptr->mode & PNG_HAVE_IDAT) != 0)
+ png_ptr->mode |= PNG_AFTER_IDAT;
+
+ if (length != 7)
+ {
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "invalid");
+ return;
+ }
+
+ png_crc_read(png_ptr, buf, 7);
+
+ if (png_crc_finish(png_ptr, 0) != 0)
+ return;
+
+ mod_time.second = buf[6];
+ mod_time.minute = buf[5];
+ mod_time.hour = buf[4];
+ mod_time.day = buf[3];
+ mod_time.month = buf[2];
+ mod_time.year = png_get_uint_16(buf);
+
+ png_set_tIME(png_ptr, info_ptr, &mod_time);
+}
+#endif
+
+#ifdef PNG_READ_tEXt_SUPPORTED
+/* Note: this does not properly handle chunks that are > 64K under DOS */
+void /* PRIVATE */
+png_handle_tEXt(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
+{
+ png_text text_info;
+ png_bytep buffer;
+ png_charp key;
+ png_charp text;
+ png_uint_32 skip = 0;
+
+ png_debug(1, "in png_handle_tEXt");
+
+#ifdef PNG_USER_LIMITS_SUPPORTED
+ if (png_ptr->user_chunk_cache_max != 0)
+ {
+ if (png_ptr->user_chunk_cache_max == 1)
+ {
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ if (--png_ptr->user_chunk_cache_max == 1)
+ {
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "no space in chunk cache");
+ return;
+ }
+ }
+#endif
+
+ if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
+ png_chunk_error(png_ptr, "missing IHDR");
+
+ if ((png_ptr->mode & PNG_HAVE_IDAT) != 0)
+ png_ptr->mode |= PNG_AFTER_IDAT;
+
+#ifdef PNG_MAX_MALLOC_64K
+ if (length > 65535U)
+ {
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "too large to fit in memory");
+ return;
+ }
+#endif
+
+ buffer = png_read_buffer(png_ptr, length+1, 1/*warn*/);
+
+ if (buffer == NULL)
+ {
+ png_chunk_benign_error(png_ptr, "out of memory");
+ return;
+ }
+
+ png_crc_read(png_ptr, buffer, length);
+
+ if (png_crc_finish(png_ptr, skip) != 0)
+ return;
+
+ key = (png_charp)buffer;
+ key[length] = 0;
+
+ for (text = key; *text; text++)
+ /* Empty loop to find end of key */ ;
+
+ if (text != key + length)
+ text++;
+
+ text_info.compression = PNG_TEXT_COMPRESSION_NONE;
+ text_info.key = key;
+ text_info.lang = NULL;
+ text_info.lang_key = NULL;
+ text_info.itxt_length = 0;
+ text_info.text = text;
+ text_info.text_length = strlen(text);
+
+ if (png_set_text_2(png_ptr, info_ptr, &text_info, 1) != 0)
+ png_warning(png_ptr, "Insufficient memory to process text chunk");
+}
+#endif
+
+#ifdef PNG_READ_zTXt_SUPPORTED
+/* Note: this does not correctly handle chunks that are > 64K under DOS */
+void /* PRIVATE */
+png_handle_zTXt(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
+{
+ png_const_charp errmsg = NULL;
+ png_bytep buffer;
+ png_uint_32 keyword_length;
+
+ png_debug(1, "in png_handle_zTXt");
+
+#ifdef PNG_USER_LIMITS_SUPPORTED
+ if (png_ptr->user_chunk_cache_max != 0)
+ {
+ if (png_ptr->user_chunk_cache_max == 1)
+ {
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ if (--png_ptr->user_chunk_cache_max == 1)
+ {
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "no space in chunk cache");
+ return;
+ }
+ }
+#endif
+
+ if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
+ png_chunk_error(png_ptr, "missing IHDR");
+
+ if ((png_ptr->mode & PNG_HAVE_IDAT) != 0)
+ png_ptr->mode |= PNG_AFTER_IDAT;
+
+ buffer = png_read_buffer(png_ptr, length, 2/*silent*/);
+
+ if (buffer == NULL)
+ {
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "out of memory");
+ return;
+ }
+
+ png_crc_read(png_ptr, buffer, length);
+
+ if (png_crc_finish(png_ptr, 0) != 0)
+ return;
+
+ /* TODO: also check that the keyword contents match the spec! */
+ for (keyword_length = 0;
+ keyword_length < length && buffer[keyword_length] != 0;
+ ++keyword_length)
+ /* Empty loop to find end of name */ ;
+
+ if (keyword_length > 79 || keyword_length < 1)
+ errmsg = "bad keyword";
+
+ /* zTXt must have some LZ data after the keyword, although it may expand to
+ * zero bytes; we need a '\0' at the end of the keyword, the compression type
+ * then the LZ data:
+ */
+ else if (keyword_length + 3 > length)
+ errmsg = "truncated";
+
+ else if (buffer[keyword_length+1] != PNG_COMPRESSION_TYPE_BASE)
+ errmsg = "unknown compression type";
+
+ else
+ {
+ png_alloc_size_t uncompressed_length = PNG_SIZE_MAX;
+
+ /* TODO: at present png_decompress_chunk imposes a single application
+ * level memory limit, this should be split to different values for iCCP
+ * and text chunks.
+ */
+ if (png_decompress_chunk(png_ptr, length, keyword_length+2,
+ &uncompressed_length, 1/*terminate*/) == Z_STREAM_END)
+ {
+ png_text text;
+
+ /* It worked; png_ptr->read_buffer now looks like a tEXt chunk except
+ * for the extra compression type byte and the fact that it isn't
+ * necessarily '\0' terminated.
+ */
+ buffer = png_ptr->read_buffer;
+ buffer[uncompressed_length+(keyword_length+2)] = 0;
+
+ text.compression = PNG_TEXT_COMPRESSION_zTXt;
+ text.key = (png_charp)buffer;
+ text.text = (png_charp)(buffer + keyword_length+2);
+ text.text_length = uncompressed_length;
+ text.itxt_length = 0;
+ text.lang = NULL;
+ text.lang_key = NULL;
+
+ if (png_set_text_2(png_ptr, info_ptr, &text, 1) != 0)
+ errmsg = "insufficient memory";
+ }
+
+ else
+ errmsg = png_ptr->zstream.msg;
+ }
+
+ if (errmsg != NULL)
+ png_chunk_benign_error(png_ptr, errmsg);
+}
+#endif
+
+#ifdef PNG_READ_iTXt_SUPPORTED
+/* Note: this does not correctly handle chunks that are > 64K under DOS */
+void /* PRIVATE */
+png_handle_iTXt(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
+{
+ png_const_charp errmsg = NULL;
+ png_bytep buffer;
+ png_uint_32 prefix_length;
+
+ png_debug(1, "in png_handle_iTXt");
+
+#ifdef PNG_USER_LIMITS_SUPPORTED
+ if (png_ptr->user_chunk_cache_max != 0)
+ {
+ if (png_ptr->user_chunk_cache_max == 1)
+ {
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ if (--png_ptr->user_chunk_cache_max == 1)
+ {
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "no space in chunk cache");
+ return;
+ }
+ }
+#endif
+
+ if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
+ png_chunk_error(png_ptr, "missing IHDR");
+
+ if ((png_ptr->mode & PNG_HAVE_IDAT) != 0)
+ png_ptr->mode |= PNG_AFTER_IDAT;
+
+ buffer = png_read_buffer(png_ptr, length+1, 1/*warn*/);
+
+ if (buffer == NULL)
+ {
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "out of memory");
+ return;
+ }
+
+ png_crc_read(png_ptr, buffer, length);
+
+ if (png_crc_finish(png_ptr, 0) != 0)
+ return;
+
+ /* First the keyword. */
+ for (prefix_length=0;
+ prefix_length < length && buffer[prefix_length] != 0;
+ ++prefix_length)
+ /* Empty loop */ ;
+
+ /* Perform a basic check on the keyword length here. */
+ if (prefix_length > 79 || prefix_length < 1)
+ errmsg = "bad keyword";
+
+ /* Expect keyword, compression flag, compression type, language, translated
+ * keyword (both may be empty but are 0 terminated) then the text, which may
+ * be empty.
+ */
+ else if (prefix_length + 5 > length)
+ errmsg = "truncated";
+
+ else if (buffer[prefix_length+1] == 0 ||
+ (buffer[prefix_length+1] == 1 &&
+ buffer[prefix_length+2] == PNG_COMPRESSION_TYPE_BASE))
+ {
+ int compressed = buffer[prefix_length+1] != 0;
+ png_uint_32 language_offset, translated_keyword_offset;
+ png_alloc_size_t uncompressed_length = 0;
+
+ /* Now the language tag */
+ prefix_length += 3;
+ language_offset = prefix_length;
+
+ for (; prefix_length < length && buffer[prefix_length] != 0;
+ ++prefix_length)
+ /* Empty loop */ ;
+
+ /* WARNING: the length may be invalid here, this is checked below. */
+ translated_keyword_offset = ++prefix_length;
+
+ for (; prefix_length < length && buffer[prefix_length] != 0;
+ ++prefix_length)
+ /* Empty loop */ ;
+
+ /* prefix_length should now be at the trailing '\0' of the translated
+ * keyword, but it may already be over the end. None of this arithmetic
+ * can overflow because chunks are at most 2^31 bytes long, but on 16-bit
+ * systems the available allocation may overflow.
+ */
+ ++prefix_length;
+
+ if (compressed == 0 && prefix_length <= length)
+ uncompressed_length = length - prefix_length;
+
+ else if (compressed != 0 && prefix_length < length)
+ {
+ uncompressed_length = PNG_SIZE_MAX;
+
+ /* TODO: at present png_decompress_chunk imposes a single application
+ * level memory limit, this should be split to different values for
+ * iCCP and text chunks.
+ */
+ if (png_decompress_chunk(png_ptr, length, prefix_length,
+ &uncompressed_length, 1/*terminate*/) == Z_STREAM_END)
+ buffer = png_ptr->read_buffer;
+
+ else
+ errmsg = png_ptr->zstream.msg;
+ }
+
+ else
+ errmsg = "truncated";
+
+ if (errmsg == NULL)
+ {
+ png_text text;
+
+ buffer[uncompressed_length+prefix_length] = 0;
+
+ if (compressed == 0)
+ text.compression = PNG_ITXT_COMPRESSION_NONE;
+
+ else
+ text.compression = PNG_ITXT_COMPRESSION_zTXt;
+
+ text.key = (png_charp)buffer;
+ text.lang = (png_charp)buffer + language_offset;
+ text.lang_key = (png_charp)buffer + translated_keyword_offset;
+ text.text = (png_charp)buffer + prefix_length;
+ text.text_length = 0;
+ text.itxt_length = uncompressed_length;
+
+ if (png_set_text_2(png_ptr, info_ptr, &text, 1) != 0)
+ errmsg = "insufficient memory";
+ }
+ }
+
+ else
+ errmsg = "bad compression info";
+
+ if (errmsg != NULL)
+ png_chunk_benign_error(png_ptr, errmsg);
+}
+#endif
+
+#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
+/* Utility function for png_handle_unknown; set up png_ptr::unknown_chunk */
+static int
+png_cache_unknown_chunk(png_structrp png_ptr, png_uint_32 length)
+{
+ png_alloc_size_t limit = PNG_SIZE_MAX;
+
+ if (png_ptr->unknown_chunk.data != NULL)
+ {
+ png_free(png_ptr, png_ptr->unknown_chunk.data);
+ png_ptr->unknown_chunk.data = NULL;
+ }
+
+# ifdef PNG_SET_USER_LIMITS_SUPPORTED
+ if (png_ptr->user_chunk_malloc_max > 0 &&
+ png_ptr->user_chunk_malloc_max < limit)
+ limit = png_ptr->user_chunk_malloc_max;
+
+# elif PNG_USER_CHUNK_MALLOC_MAX > 0
+ if (PNG_USER_CHUNK_MALLOC_MAX < limit)
+ limit = PNG_USER_CHUNK_MALLOC_MAX;
+# endif
+
+ if (length <= limit)
+ {
+ PNG_CSTRING_FROM_CHUNK(png_ptr->unknown_chunk.name, png_ptr->chunk_name);
+ /* The following is safe because of the PNG_SIZE_MAX init above */
+ png_ptr->unknown_chunk.size = (png_size_t)length/*SAFE*/;
+ /* 'mode' is a flag array, only the bottom four bits matter here */
+ png_ptr->unknown_chunk.location = (png_byte)png_ptr->mode/*SAFE*/;
+
+ if (length == 0)
+ png_ptr->unknown_chunk.data = NULL;
+
+ else
+ {
+ /* Do a 'warn' here - it is handled below. */
+ png_ptr->unknown_chunk.data = png_voidcast(png_bytep,
+ png_malloc_warn(png_ptr, length));
+ }
+ }
+
+ if (png_ptr->unknown_chunk.data == NULL && length > 0)
+ {
+ /* This is benign because we clean up correctly */
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "unknown chunk exceeds memory limits");
+ return 0;
+ }
+
+ else
+ {
+ if (length > 0)
+ png_crc_read(png_ptr, png_ptr->unknown_chunk.data, length);
+ png_crc_finish(png_ptr, 0);
+ return 1;
+ }
+}
+#endif /* READ_UNKNOWN_CHUNKS */
+
+/* Handle an unknown, or known but disabled, chunk */
+void /* PRIVATE */
+png_handle_unknown(png_structrp png_ptr, png_inforp info_ptr,
+ png_uint_32 length, int keep)
+{
+ int handled = 0; /* the chunk was handled */
+
+ png_debug(1, "in png_handle_unknown");
+
+#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
+ /* NOTE: this code is based on the code in libpng-1.4.12 except for fixing
+ * the bug which meant that setting a non-default behavior for a specific
+ * chunk would be ignored (the default was always used unless a user
+ * callback was installed).
+ *
+ * 'keep' is the value from the png_chunk_unknown_handling, the setting for
+ * this specific chunk_name, if PNG_HANDLE_AS_UNKNOWN_SUPPORTED, if not it
+ * will always be PNG_HANDLE_CHUNK_AS_DEFAULT and it needs to be set here.
+ * This is just an optimization to avoid multiple calls to the lookup
+ * function.
+ */
+# ifndef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+# ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
+ keep = png_chunk_unknown_handling(png_ptr, png_ptr->chunk_name);
+# endif
+# endif
+
+ /* One of the following methods will read the chunk or skip it (at least one
+ * of these is always defined because this is the only way to switch on
+ * PNG_READ_UNKNOWN_CHUNKS_SUPPORTED)
+ */
+# ifdef PNG_READ_USER_CHUNKS_SUPPORTED
+ /* The user callback takes precedence over the chunk keep value, but the
+ * keep value is still required to validate a save of a critical chunk.
+ */
+ if (png_ptr->read_user_chunk_fn != NULL)
+ {
+ if (png_cache_unknown_chunk(png_ptr, length) != 0)
+ {
+ /* Callback to user unknown chunk handler */
+ int ret = (*(png_ptr->read_user_chunk_fn))(png_ptr,
+ &png_ptr->unknown_chunk);
+
+ /* ret is:
+ * negative: An error occurred; png_chunk_error will be called.
+ * zero: The chunk was not handled, the chunk will be discarded
+ * unless png_set_keep_unknown_chunks has been used to set
+ * a 'keep' behavior for this particular chunk, in which
+ * case that will be used. A critical chunk will cause an
+ * error at this point unless it is to be saved.
+ * positive: The chunk was handled, libpng will ignore/discard it.
+ */
+ if (ret < 0)
+ png_chunk_error(png_ptr, "error in user chunk");
+
+ else if (ret == 0)
+ {
+ /* If the keep value is 'default' or 'never' override it, but
+ * still error out on critical chunks unless the keep value is
+ * 'always' While this is weird it is the behavior in 1.4.12.
+ * A possible improvement would be to obey the value set for the
+ * chunk, but this would be an API change that would probably
+ * damage some applications.
+ *
+ * The png_app_warning below catches the case that matters, where
+ * the application has not set specific save or ignore for this
+ * chunk or global save or ignore.
+ */
+ if (keep < PNG_HANDLE_CHUNK_IF_SAFE)
+ {
+# ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
+ if (png_ptr->unknown_default < PNG_HANDLE_CHUNK_IF_SAFE)
+ {
+ png_chunk_warning(png_ptr, "Saving unknown chunk:");
+ png_app_warning(png_ptr,
+ "forcing save of an unhandled chunk;"
+ " please call png_set_keep_unknown_chunks");
+ /* with keep = PNG_HANDLE_CHUNK_IF_SAFE */
+ }
+# endif
+ keep = PNG_HANDLE_CHUNK_IF_SAFE;
+ }
+ }
+
+ else /* chunk was handled */
+ {
+ handled = 1;
+ /* Critical chunks can be safely discarded at this point. */
+ keep = PNG_HANDLE_CHUNK_NEVER;
+ }
+ }
+
+ else
+ keep = PNG_HANDLE_CHUNK_NEVER; /* insufficient memory */
+ }
+
+ else
+ /* Use the SAVE_UNKNOWN_CHUNKS code or skip the chunk */
+# endif /* READ_USER_CHUNKS */
+
+# ifdef PNG_SAVE_UNKNOWN_CHUNKS_SUPPORTED
+ {
+ /* keep is currently just the per-chunk setting, if there was no
+ * setting change it to the global default now (not that this may
+ * still be AS_DEFAULT) then obtain the cache of the chunk if required,
+ * if not simply skip the chunk.
+ */
+ if (keep == PNG_HANDLE_CHUNK_AS_DEFAULT)
+ keep = png_ptr->unknown_default;
+
+ if (keep == PNG_HANDLE_CHUNK_ALWAYS ||
+ (keep == PNG_HANDLE_CHUNK_IF_SAFE &&
+ PNG_CHUNK_ANCILLARY(png_ptr->chunk_name)))
+ {
+ if (png_cache_unknown_chunk(png_ptr, length) == 0)
+ keep = PNG_HANDLE_CHUNK_NEVER;
+ }
+
+ else
+ png_crc_finish(png_ptr, length);
+ }
+# else
+# ifndef PNG_READ_USER_CHUNKS_SUPPORTED
+# error no method to support READ_UNKNOWN_CHUNKS
+# endif
+
+ {
+ /* If here there is no read callback pointer set and no support is
+ * compiled in to just save the unknown chunks, so simply skip this
+ * chunk. If 'keep' is something other than AS_DEFAULT or NEVER then
+ * the app has erroneously asked for unknown chunk saving when there
+ * is no support.
+ */
+ if (keep > PNG_HANDLE_CHUNK_NEVER)
+ png_app_error(png_ptr, "no unknown chunk support available");
+
+ png_crc_finish(png_ptr, length);
+ }
+# endif
+
+# ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
+ /* Now store the chunk in the chunk list if appropriate, and if the limits
+ * permit it.
+ */
+ if (keep == PNG_HANDLE_CHUNK_ALWAYS ||
+ (keep == PNG_HANDLE_CHUNK_IF_SAFE &&
+ PNG_CHUNK_ANCILLARY(png_ptr->chunk_name)))
+ {
+# ifdef PNG_USER_LIMITS_SUPPORTED
+ switch (png_ptr->user_chunk_cache_max)
+ {
+ case 2:
+ png_ptr->user_chunk_cache_max = 1;
+ png_chunk_benign_error(png_ptr, "no space in chunk cache");
+ /* FALL THROUGH */
+ case 1:
+ /* NOTE: prior to 1.6.0 this case resulted in an unknown critical
+ * chunk being skipped, now there will be a hard error below.
+ */
+ break;
+
+ default: /* not at limit */
+ --(png_ptr->user_chunk_cache_max);
+ /* FALL THROUGH */
+ case 0: /* no limit */
+# endif /* USER_LIMITS */
+ /* Here when the limit isn't reached or when limits are compiled
+ * out; store the chunk.
+ */
+ png_set_unknown_chunks(png_ptr, info_ptr,
+ &png_ptr->unknown_chunk, 1);
+ handled = 1;
+# ifdef PNG_USER_LIMITS_SUPPORTED
+ break;
+ }
+# endif
+ }
+# else /* no store support: the chunk must be handled by the user callback */
+ PNG_UNUSED(info_ptr)
+# endif
+
+ /* Regardless of the error handling below the cached data (if any) can be
+ * freed now. Notice that the data is not freed if there is a png_error, but
+ * it will be freed by destroy_read_struct.
+ */
+ if (png_ptr->unknown_chunk.data != NULL)
+ png_free(png_ptr, png_ptr->unknown_chunk.data);
+ png_ptr->unknown_chunk.data = NULL;
+
+#else /* !PNG_READ_UNKNOWN_CHUNKS_SUPPORTED */
+ /* There is no support to read an unknown chunk, so just skip it. */
+ png_crc_finish(png_ptr, length);
+ PNG_UNUSED(info_ptr)
+ PNG_UNUSED(keep)
+#endif /* !READ_UNKNOWN_CHUNKS */
+
+ /* Check for unhandled critical chunks */
+ if (handled == 0 && PNG_CHUNK_CRITICAL(png_ptr->chunk_name))
+ png_chunk_error(png_ptr, "unhandled critical chunk");
+}
+
+/* This function is called to verify that a chunk name is valid.
+ * This function can't have the "critical chunk check" incorporated
+ * into it, since in the future we will need to be able to call user
+ * functions to handle unknown critical chunks after we check that
+ * the chunk name itself is valid.
+ */
+
+/* Bit hacking: the test for an invalid byte in the 4 byte chunk name is:
+ *
+ * ((c) < 65 || (c) > 122 || ((c) > 90 && (c) < 97))
+ */
+
+void /* PRIVATE */
+png_check_chunk_name(png_structrp png_ptr, png_uint_32 chunk_name)
+{
+ int i;
+
+ png_debug(1, "in png_check_chunk_name");
+
+ for (i=1; i<=4; ++i)
+ {
+ int c = chunk_name & 0xff;
+
+ if (c < 65 || c > 122 || (c > 90 && c < 97))
+ png_chunk_error(png_ptr, "invalid chunk type");
+
+ chunk_name >>= 8;
+ }
+}
+
+/* Combines the row recently read in with the existing pixels in the row. This
+ * routine takes care of alpha and transparency if requested. This routine also
+ * handles the two methods of progressive display of interlaced images,
+ * depending on the 'display' value; if 'display' is true then the whole row
+ * (dp) is filled from the start by replicating the available pixels. If
+ * 'display' is false only those pixels present in the pass are filled in.
+ */
+void /* PRIVATE */
+png_combine_row(png_const_structrp png_ptr, png_bytep dp, int display)
+{
+ unsigned int pixel_depth = png_ptr->transformed_pixel_depth;
+ png_const_bytep sp = png_ptr->row_buf + 1;
+ png_alloc_size_t row_width = png_ptr->width;
+ unsigned int pass = png_ptr->pass;
+ png_bytep end_ptr = 0;
+ png_byte end_byte = 0;
+ unsigned int end_mask;
+
+ png_debug(1, "in png_combine_row");
+
+ /* Added in 1.5.6: it should not be possible to enter this routine until at
+ * least one row has been read from the PNG data and transformed.
+ */
+ if (pixel_depth == 0)
+ png_error(png_ptr, "internal row logic error");
+
+ /* Added in 1.5.4: the pixel depth should match the information returned by
+ * any call to png_read_update_info at this point. Do not continue if we got
+ * this wrong.
+ */
+ if (png_ptr->info_rowbytes != 0 && png_ptr->info_rowbytes !=
+ PNG_ROWBYTES(pixel_depth, row_width))
+ png_error(png_ptr, "internal row size calculation error");
+
+ /* Don't expect this to ever happen: */
+ if (row_width == 0)
+ png_error(png_ptr, "internal row width error");
+
+ /* Preserve the last byte in cases where only part of it will be overwritten,
+ * the multiply below may overflow, we don't care because ANSI-C guarantees
+ * we get the low bits.
+ */
+ end_mask = (pixel_depth * row_width) & 7;
+ if (end_mask != 0)
+ {
+ /* end_ptr == NULL is a flag to say do nothing */
+ end_ptr = dp + PNG_ROWBYTES(pixel_depth, row_width) - 1;
+ end_byte = *end_ptr;
+# ifdef PNG_READ_PACKSWAP_SUPPORTED
+ if ((png_ptr->transformations & PNG_PACKSWAP) != 0)
+ /* little-endian byte */
+ end_mask = 0xff << end_mask;
+
+ else /* big-endian byte */
+# endif
+ end_mask = 0xff >> end_mask;
+ /* end_mask is now the bits to *keep* from the destination row */
+ }
+
+ /* For non-interlaced images this reduces to a memcpy(). A memcpy()
+ * will also happen if interlacing isn't supported or if the application
+ * does not call png_set_interlace_handling(). In the latter cases the
+ * caller just gets a sequence of the unexpanded rows from each interlace
+ * pass.
+ */
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+ if (png_ptr->interlaced != 0 &&
+ (png_ptr->transformations & PNG_INTERLACE) != 0 &&
+ pass < 6 && (display == 0 ||
+ /* The following copies everything for 'display' on passes 0, 2 and 4. */
+ (display == 1 && (pass & 1) != 0)))
+ {
+ /* Narrow images may have no bits in a pass; the caller should handle
+ * this, but this test is cheap:
+ */
+ if (row_width <= PNG_PASS_START_COL(pass))
+ return;
+
+ if (pixel_depth < 8)
+ {
+ /* For pixel depths up to 4 bpp the 8-pixel mask can be expanded to fit
+ * into 32 bits, then a single loop over the bytes using the four byte
+ * values in the 32-bit mask can be used. For the 'display' option the
+ * expanded mask may also not require any masking within a byte. To
+ * make this work the PACKSWAP option must be taken into account - it
+ * simply requires the pixels to be reversed in each byte.
+ *
+ * The 'regular' case requires a mask for each of the first 6 passes,
+ * the 'display' case does a copy for the even passes in the range
+ * 0..6. This has already been handled in the test above.
+ *
+ * The masks are arranged as four bytes with the first byte to use in
+ * the lowest bits (little-endian) regardless of the order (PACKSWAP or
+ * not) of the pixels in each byte.
+ *
+ * NOTE: the whole of this logic depends on the caller of this function
+ * only calling it on rows appropriate to the pass. This function only
+ * understands the 'x' logic; the 'y' logic is handled by the caller.
+ *
+ * The following defines allow generation of compile time constant bit
+ * masks for each pixel depth and each possibility of swapped or not
+ * swapped bytes. Pass 'p' is in the range 0..6; 'x', a pixel index,
+ * is in the range 0..7; and the result is 1 if the pixel is to be
+ * copied in the pass, 0 if not. 'S' is for the sparkle method, 'B'
+ * for the block method.
+ *
+ * With some compilers a compile time expression of the general form:
+ *
+ * (shift >= 32) ? (a >> (shift-32)) : (b >> shift)
+ *
+ * Produces warnings with values of 'shift' in the range 33 to 63
+ * because the right hand side of the ?: expression is evaluated by
+ * the compiler even though it isn't used. Microsoft Visual C (various
+ * versions) and the Intel C compiler are known to do this. To avoid
+ * this the following macros are used in 1.5.6. This is a temporary
+ * solution to avoid destabilizing the code during the release process.
+ */
+# if PNG_USE_COMPILE_TIME_MASKS
+# define PNG_LSR(x,s) ((x)>>((s) & 0x1f))
+# define PNG_LSL(x,s) ((x)<<((s) & 0x1f))
+# else
+# define PNG_LSR(x,s) ((x)>>(s))
+# define PNG_LSL(x,s) ((x)<<(s))
+# endif
+# define S_COPY(p,x) (((p)<4 ? PNG_LSR(0x80088822,(3-(p))*8+(7-(x))) :\
+ PNG_LSR(0xaa55ff00,(7-(p))*8+(7-(x)))) & 1)
+# define B_COPY(p,x) (((p)<4 ? PNG_LSR(0xff0fff33,(3-(p))*8+(7-(x))) :\
+ PNG_LSR(0xff55ff00,(7-(p))*8+(7-(x)))) & 1)
+
+ /* Return a mask for pass 'p' pixel 'x' at depth 'd'. The mask is
+ * little endian - the first pixel is at bit 0 - however the extra
+ * parameter 's' can be set to cause the mask position to be swapped
+ * within each byte, to match the PNG format. This is done by XOR of
+ * the shift with 7, 6 or 4 for bit depths 1, 2 and 4.
+ */
+# define PIXEL_MASK(p,x,d,s) \
+ (PNG_LSL(((PNG_LSL(1U,(d)))-1),(((x)*(d))^((s)?8-(d):0))))
+
+ /* Hence generate the appropriate 'block' or 'sparkle' pixel copy mask.
+ */
+# define S_MASKx(p,x,d,s) (S_COPY(p,x)?PIXEL_MASK(p,x,d,s):0)
+# define B_MASKx(p,x,d,s) (B_COPY(p,x)?PIXEL_MASK(p,x,d,s):0)
+
+ /* Combine 8 of these to get the full mask. For the 1-bpp and 2-bpp
+ * cases the result needs replicating, for the 4-bpp case the above
+ * generates a full 32 bits.
+ */
+# define MASK_EXPAND(m,d) ((m)*((d)==1?0x01010101:((d)==2?0x00010001:1)))
+
+# define S_MASK(p,d,s) MASK_EXPAND(S_MASKx(p,0,d,s) + S_MASKx(p,1,d,s) +\
+ S_MASKx(p,2,d,s) + S_MASKx(p,3,d,s) + S_MASKx(p,4,d,s) +\
+ S_MASKx(p,5,d,s) + S_MASKx(p,6,d,s) + S_MASKx(p,7,d,s), d)
+
+# define B_MASK(p,d,s) MASK_EXPAND(B_MASKx(p,0,d,s) + B_MASKx(p,1,d,s) +\
+ B_MASKx(p,2,d,s) + B_MASKx(p,3,d,s) + B_MASKx(p,4,d,s) +\
+ B_MASKx(p,5,d,s) + B_MASKx(p,6,d,s) + B_MASKx(p,7,d,s), d)
+
+#if PNG_USE_COMPILE_TIME_MASKS
+ /* Utility macros to construct all the masks for a depth/swap
+ * combination. The 's' parameter says whether the format is PNG
+ * (big endian bytes) or not. Only the three odd-numbered passes are
+ * required for the display/block algorithm.
+ */
+# define S_MASKS(d,s) { S_MASK(0,d,s), S_MASK(1,d,s), S_MASK(2,d,s),\
+ S_MASK(3,d,s), S_MASK(4,d,s), S_MASK(5,d,s) }
+
+# define B_MASKS(d,s) { B_MASK(1,d,s), B_MASK(3,d,s), B_MASK(5,d,s) }
+
+# define DEPTH_INDEX(d) ((d)==1?0:((d)==2?1:2))
+
+ /* Hence the pre-compiled masks indexed by PACKSWAP (or not), depth and
+ * then pass:
+ */
+ static PNG_CONST png_uint_32 row_mask[2/*PACKSWAP*/][3/*depth*/][6] =
+ {
+ /* Little-endian byte masks for PACKSWAP */
+ { S_MASKS(1,0), S_MASKS(2,0), S_MASKS(4,0) },
+ /* Normal (big-endian byte) masks - PNG format */
+ { S_MASKS(1,1), S_MASKS(2,1), S_MASKS(4,1) }
+ };
+
+ /* display_mask has only three entries for the odd passes, so index by
+ * pass>>1.
+ */
+ static PNG_CONST png_uint_32 display_mask[2][3][3] =
+ {
+ /* Little-endian byte masks for PACKSWAP */
+ { B_MASKS(1,0), B_MASKS(2,0), B_MASKS(4,0) },
+ /* Normal (big-endian byte) masks - PNG format */
+ { B_MASKS(1,1), B_MASKS(2,1), B_MASKS(4,1) }
+ };
+
+# define MASK(pass,depth,display,png)\
+ ((display)?display_mask[png][DEPTH_INDEX(depth)][pass>>1]:\
+ row_mask[png][DEPTH_INDEX(depth)][pass])
+
+#else /* !PNG_USE_COMPILE_TIME_MASKS */
+ /* This is the runtime alternative: it seems unlikely that this will
+ * ever be either smaller or faster than the compile time approach.
+ */
+# define MASK(pass,depth,display,png)\
+ ((display)?B_MASK(pass,depth,png):S_MASK(pass,depth,png))
+#endif /* !USE_COMPILE_TIME_MASKS */
+
+ /* Use the appropriate mask to copy the required bits. In some cases
+ * the byte mask will be 0 or 0xff; optimize these cases. row_width is
+ * the number of pixels, but the code copies bytes, so it is necessary
+ * to special case the end.
+ */
+ png_uint_32 pixels_per_byte = 8 / pixel_depth;
+ png_uint_32 mask;
+
+# ifdef PNG_READ_PACKSWAP_SUPPORTED
+ if ((png_ptr->transformations & PNG_PACKSWAP) != 0)
+ mask = MASK(pass, pixel_depth, display, 0);
+
+ else
+# endif
+ mask = MASK(pass, pixel_depth, display, 1);
+
+ for (;;)
+ {
+ png_uint_32 m;
+
+ /* It doesn't matter in the following if png_uint_32 has more than
+ * 32 bits because the high bits always match those in m<<24; it is,
+ * however, essential to use OR here, not +, because of this.
+ */
+ m = mask;
+ mask = (m >> 8) | (m << 24); /* rotate right to good compilers */
+ m &= 0xff;
+
+ if (m != 0) /* something to copy */
+ {
+ if (m != 0xff)
+ *dp = (png_byte)((*dp & ~m) | (*sp & m));
+ else
+ *dp = *sp;
+ }
+
+ /* NOTE: this may overwrite the last byte with garbage if the image
+ * is not an exact number of bytes wide; libpng has always done
+ * this.
+ */
+ if (row_width <= pixels_per_byte)
+ break; /* May need to restore part of the last byte */
+
+ row_width -= pixels_per_byte;
+ ++dp;
+ ++sp;
+ }
+ }
+
+ else /* pixel_depth >= 8 */
+ {
+ unsigned int bytes_to_copy, bytes_to_jump;
+
+ /* Validate the depth - it must be a multiple of 8 */
+ if (pixel_depth & 7)
+ png_error(png_ptr, "invalid user transform pixel depth");
+
+ pixel_depth >>= 3; /* now in bytes */
+ row_width *= pixel_depth;
+
+ /* Regardless of pass number the Adam 7 interlace always results in a
+ * fixed number of pixels to copy then to skip. There may be a
+ * different number of pixels to skip at the start though.
+ */
+ {
+ unsigned int offset = PNG_PASS_START_COL(pass) * pixel_depth;
+
+ row_width -= offset;
+ dp += offset;
+ sp += offset;
+ }
+
+ /* Work out the bytes to copy. */
+ if (display != 0)
+ {
+ /* When doing the 'block' algorithm the pixel in the pass gets
+ * replicated to adjacent pixels. This is why the even (0,2,4,6)
+ * passes are skipped above - the entire expanded row is copied.
+ */
+ bytes_to_copy = (1<<((6-pass)>>1)) * pixel_depth;
+
+ /* But don't allow this number to exceed the actual row width. */
+ if (bytes_to_copy > row_width)
+ bytes_to_copy = (unsigned int)/*SAFE*/row_width;
+ }
+
+ else /* normal row; Adam7 only ever gives us one pixel to copy. */
+ bytes_to_copy = pixel_depth;
+
+ /* In Adam7 there is a constant offset between where the pixels go. */
+ bytes_to_jump = PNG_PASS_COL_OFFSET(pass) * pixel_depth;
+
+ /* And simply copy these bytes. Some optimization is possible here,
+ * depending on the value of 'bytes_to_copy'. Special case the low
+ * byte counts, which we know to be frequent.
+ *
+ * Notice that these cases all 'return' rather than 'break' - this
+ * avoids an unnecessary test on whether to restore the last byte
+ * below.
+ */
+ switch (bytes_to_copy)
+ {
+ case 1:
+ for (;;)
+ {
+ *dp = *sp;
+
+ if (row_width <= bytes_to_jump)
+ return;
+
+ dp += bytes_to_jump;
+ sp += bytes_to_jump;
+ row_width -= bytes_to_jump;
+ }
+
+ case 2:
+ /* There is a possibility of a partial copy at the end here; this
+ * slows the code down somewhat.
+ */
+ do
+ {
+ dp[0] = sp[0], dp[1] = sp[1];
+
+ if (row_width <= bytes_to_jump)
+ return;
+
+ sp += bytes_to_jump;
+ dp += bytes_to_jump;
+ row_width -= bytes_to_jump;
+ }
+ while (row_width > 1);
+
+ /* And there can only be one byte left at this point: */
+ *dp = *sp;
+ return;
+
+ case 3:
+ /* This can only be the RGB case, so each copy is exactly one
+ * pixel and it is not necessary to check for a partial copy.
+ */
+ for (;;)
+ {
+ dp[0] = sp[0], dp[1] = sp[1], dp[2] = sp[2];
+
+ if (row_width <= bytes_to_jump)
+ return;
+
+ sp += bytes_to_jump;
+ dp += bytes_to_jump;
+ row_width -= bytes_to_jump;
+ }
+
+ default:
+#if PNG_ALIGN_TYPE != PNG_ALIGN_NONE
+ /* Check for double byte alignment and, if possible, use a
+ * 16-bit copy. Don't attempt this for narrow images - ones that
+ * are less than an interlace panel wide. Don't attempt it for
+ * wide bytes_to_copy either - use the memcpy there.
+ */
+ if (bytes_to_copy < 16 /*else use memcpy*/ &&
+ png_isaligned(dp, png_uint_16) &&
+ png_isaligned(sp, png_uint_16) &&
+ bytes_to_copy % (sizeof (png_uint_16)) == 0 &&
+ bytes_to_jump % (sizeof (png_uint_16)) == 0)
+ {
+ /* Everything is aligned for png_uint_16 copies, but try for
+ * png_uint_32 first.
+ */
+ if (png_isaligned(dp, png_uint_32) != 0 &&
+ png_isaligned(sp, png_uint_32) != 0 &&
+ bytes_to_copy % (sizeof (png_uint_32)) == 0 &&
+ bytes_to_jump % (sizeof (png_uint_32)) == 0)
+ {
+ png_uint_32p dp32 = png_aligncast(png_uint_32p,dp);
+ png_const_uint_32p sp32 = png_aligncastconst(
+ png_const_uint_32p, sp);
+ size_t skip = (bytes_to_jump-bytes_to_copy) /
+ (sizeof (png_uint_32));
+
+ do
+ {
+ size_t c = bytes_to_copy;
+ do
+ {
+ *dp32++ = *sp32++;
+ c -= (sizeof (png_uint_32));
+ }
+ while (c > 0);
+
+ if (row_width <= bytes_to_jump)
+ return;
+
+ dp32 += skip;
+ sp32 += skip;
+ row_width -= bytes_to_jump;
+ }
+ while (bytes_to_copy <= row_width);
+
+ /* Get to here when the row_width truncates the final copy.
+ * There will be 1-3 bytes left to copy, so don't try the
+ * 16-bit loop below.
+ */
+ dp = (png_bytep)dp32;
+ sp = (png_const_bytep)sp32;
+ do
+ *dp++ = *sp++;
+ while (--row_width > 0);
+ return;
+ }
+
+ /* Else do it in 16-bit quantities, but only if the size is
+ * not too large.
+ */
+ else
+ {
+ png_uint_16p dp16 = png_aligncast(png_uint_16p, dp);
+ png_const_uint_16p sp16 = png_aligncastconst(
+ png_const_uint_16p, sp);
+ size_t skip = (bytes_to_jump-bytes_to_copy) /
+ (sizeof (png_uint_16));
+
+ do
+ {
+ size_t c = bytes_to_copy;
+ do
+ {
+ *dp16++ = *sp16++;
+ c -= (sizeof (png_uint_16));
+ }
+ while (c > 0);
+
+ if (row_width <= bytes_to_jump)
+ return;
+
+ dp16 += skip;
+ sp16 += skip;
+ row_width -= bytes_to_jump;
+ }
+ while (bytes_to_copy <= row_width);
+
+ /* End of row - 1 byte left, bytes_to_copy > row_width: */
+ dp = (png_bytep)dp16;
+ sp = (png_const_bytep)sp16;
+ do
+ *dp++ = *sp++;
+ while (--row_width > 0);
+ return;
+ }
+ }
+#endif /* ALIGN_TYPE code */
+
+ /* The true default - use a memcpy: */
+ for (;;)
+ {
+ memcpy(dp, sp, bytes_to_copy);
+
+ if (row_width <= bytes_to_jump)
+ return;
+
+ sp += bytes_to_jump;
+ dp += bytes_to_jump;
+ row_width -= bytes_to_jump;
+ if (bytes_to_copy > row_width)
+ bytes_to_copy = (unsigned int)/*SAFE*/row_width;
+ }
+ }
+
+ /* NOT REACHED*/
+ } /* pixel_depth >= 8 */
+
+ /* Here if pixel_depth < 8 to check 'end_ptr' below. */
+ }
+ else
+#endif /* READ_INTERLACING */
+
+ /* If here then the switch above wasn't used so just memcpy the whole row
+ * from the temporary row buffer (notice that this overwrites the end of the
+ * destination row if it is a partial byte.)
+ */
+ memcpy(dp, sp, PNG_ROWBYTES(pixel_depth, row_width));
+
+ /* Restore the overwritten bits from the last byte if necessary. */
+ if (end_ptr != NULL)
+ *end_ptr = (png_byte)((end_byte & end_mask) | (*end_ptr & ~end_mask));
+}
+
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+void /* PRIVATE */
+png_do_read_interlace(png_row_infop row_info, png_bytep row, int pass,
+ png_uint_32 transformations /* Because these may affect the byte layout */)
+{
+ /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
+ /* Offset to next interlace block */
+ static PNG_CONST int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
+
+ png_debug(1, "in png_do_read_interlace");
+ if (row != NULL && row_info != NULL)
+ {
+ png_uint_32 final_width;
+
+ final_width = row_info->width * png_pass_inc[pass];
+
+ switch (row_info->pixel_depth)
+ {
+ case 1:
+ {
+ png_bytep sp = row + (png_size_t)((row_info->width - 1) >> 3);
+ png_bytep dp = row + (png_size_t)((final_width - 1) >> 3);
+ int sshift, dshift;
+ int s_start, s_end, s_inc;
+ int jstop = png_pass_inc[pass];
+ png_byte v;
+ png_uint_32 i;
+ int j;
+
+#ifdef PNG_READ_PACKSWAP_SUPPORTED
+ if ((transformations & PNG_PACKSWAP) != 0)
+ {
+ sshift = (int)((row_info->width + 7) & 0x07);
+ dshift = (int)((final_width + 7) & 0x07);
+ s_start = 7;
+ s_end = 0;
+ s_inc = -1;
+ }
+
+ else
+#endif
+ {
+ sshift = 7 - (int)((row_info->width + 7) & 0x07);
+ dshift = 7 - (int)((final_width + 7) & 0x07);
+ s_start = 0;
+ s_end = 7;
+ s_inc = 1;
+ }
+
+ for (i = 0; i < row_info->width; i++)
+ {
+ v = (png_byte)((*sp >> sshift) & 0x01);
+ for (j = 0; j < jstop; j++)
+ {
+ unsigned int tmp = *dp & (0x7f7f >> (7 - dshift));
+ tmp |= v << dshift;
+ *dp = (png_byte)(tmp & 0xff);
+
+ if (dshift == s_end)
+ {
+ dshift = s_start;
+ dp--;
+ }
+
+ else
+ dshift += s_inc;
+ }
+
+ if (sshift == s_end)
+ {
+ sshift = s_start;
+ sp--;
+ }
+
+ else
+ sshift += s_inc;
+ }
+ break;
+ }
+
+ case 2:
+ {
+ png_bytep sp = row + (png_uint_32)((row_info->width - 1) >> 2);
+ png_bytep dp = row + (png_uint_32)((final_width - 1) >> 2);
+ int sshift, dshift;
+ int s_start, s_end, s_inc;
+ int jstop = png_pass_inc[pass];
+ png_uint_32 i;
+
+#ifdef PNG_READ_PACKSWAP_SUPPORTED
+ if ((transformations & PNG_PACKSWAP) != 0)
+ {
+ sshift = (int)(((row_info->width + 3) & 0x03) << 1);
+ dshift = (int)(((final_width + 3) & 0x03) << 1);
+ s_start = 6;
+ s_end = 0;
+ s_inc = -2;
+ }
+
+ else
+#endif
+ {
+ sshift = (int)((3 - ((row_info->width + 3) & 0x03)) << 1);
+ dshift = (int)((3 - ((final_width + 3) & 0x03)) << 1);
+ s_start = 0;
+ s_end = 6;
+ s_inc = 2;
+ }
+
+ for (i = 0; i < row_info->width; i++)
+ {
+ png_byte v;
+ int j;
+
+ v = (png_byte)((*sp >> sshift) & 0x03);
+ for (j = 0; j < jstop; j++)
+ {
+ unsigned int tmp = *dp & (0x3f3f >> (6 - dshift));
+ tmp |= v << dshift;
+ *dp = (png_byte)(tmp & 0xff);
+
+ if (dshift == s_end)
+ {
+ dshift = s_start;
+ dp--;
+ }
+
+ else
+ dshift += s_inc;
+ }
+
+ if (sshift == s_end)
+ {
+ sshift = s_start;
+ sp--;
+ }
+
+ else
+ sshift += s_inc;
+ }
+ break;
+ }
+
+ case 4:
+ {
+ png_bytep sp = row + (png_size_t)((row_info->width - 1) >> 1);
+ png_bytep dp = row + (png_size_t)((final_width - 1) >> 1);
+ int sshift, dshift;
+ int s_start, s_end, s_inc;
+ png_uint_32 i;
+ int jstop = png_pass_inc[pass];
+
+#ifdef PNG_READ_PACKSWAP_SUPPORTED
+ if ((transformations & PNG_PACKSWAP) != 0)
+ {
+ sshift = (int)(((row_info->width + 1) & 0x01) << 2);
+ dshift = (int)(((final_width + 1) & 0x01) << 2);
+ s_start = 4;
+ s_end = 0;
+ s_inc = -4;
+ }
+
+ else
+#endif
+ {
+ sshift = (int)((1 - ((row_info->width + 1) & 0x01)) << 2);
+ dshift = (int)((1 - ((final_width + 1) & 0x01)) << 2);
+ s_start = 0;
+ s_end = 4;
+ s_inc = 4;
+ }
+
+ for (i = 0; i < row_info->width; i++)
+ {
+ png_byte v = (png_byte)((*sp >> sshift) & 0x0f);
+ int j;
+
+ for (j = 0; j < jstop; j++)
+ {
+ unsigned int tmp = *dp & (0xf0f >> (4 - dshift));
+ tmp |= v << dshift;
+ *dp = (png_byte)(tmp & 0xff);
+
+ if (dshift == s_end)
+ {
+ dshift = s_start;
+ dp--;
+ }
+
+ else
+ dshift += s_inc;
+ }
+
+ if (sshift == s_end)
+ {
+ sshift = s_start;
+ sp--;
+ }
+
+ else
+ sshift += s_inc;
+ }
+ break;
+ }
+
+ default:
+ {
+ png_size_t pixel_bytes = (row_info->pixel_depth >> 3);
+
+ png_bytep sp = row + (png_size_t)(row_info->width - 1)
+ * pixel_bytes;
+
+ png_bytep dp = row + (png_size_t)(final_width - 1) * pixel_bytes;
+
+ int jstop = png_pass_inc[pass];
+ png_uint_32 i;
+
+ for (i = 0; i < row_info->width; i++)
+ {
+ png_byte v[8]; /* SAFE; pixel_depth does not exceed 64 */
+ int j;
+
+ memcpy(v, sp, pixel_bytes);
+
+ for (j = 0; j < jstop; j++)
+ {
+ memcpy(dp, v, pixel_bytes);
+ dp -= pixel_bytes;
+ }
+
+ sp -= pixel_bytes;
+ }
+ break;
+ }
+ }
+
+ row_info->width = final_width;
+ row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, final_width);
+ }
+#ifndef PNG_READ_PACKSWAP_SUPPORTED
+ PNG_UNUSED(transformations) /* Silence compiler warning */
+#endif
+}
+#endif /* READ_INTERLACING */
+
+static void
+png_read_filter_row_sub(png_row_infop row_info, png_bytep row,
+ png_const_bytep prev_row)
+{
+ png_size_t i;
+ png_size_t istop = row_info->rowbytes;
+ unsigned int bpp = (row_info->pixel_depth + 7) >> 3;
+ png_bytep rp = row + bpp;
+
+ PNG_UNUSED(prev_row)
+
+ for (i = bpp; i < istop; i++)
+ {
+ *rp = (png_byte)(((int)(*rp) + (int)(*(rp-bpp))) & 0xff);
+ rp++;
+ }
+}
+
+static void
+png_read_filter_row_up(png_row_infop row_info, png_bytep row,
+ png_const_bytep prev_row)
+{
+ png_size_t i;
+ png_size_t istop = row_info->rowbytes;
+ png_bytep rp = row;
+ png_const_bytep pp = prev_row;
+
+ for (i = 0; i < istop; i++)
+ {
+ *rp = (png_byte)(((int)(*rp) + (int)(*pp++)) & 0xff);
+ rp++;
+ }
+}
+
+static void
+png_read_filter_row_avg(png_row_infop row_info, png_bytep row,
+ png_const_bytep prev_row)
+{
+ png_size_t i;
+ png_bytep rp = row;
+ png_const_bytep pp = prev_row;
+ unsigned int bpp = (row_info->pixel_depth + 7) >> 3;
+ png_size_t istop = row_info->rowbytes - bpp;
+
+ for (i = 0; i < bpp; i++)
+ {
+ *rp = (png_byte)(((int)(*rp) +
+ ((int)(*pp++) / 2 )) & 0xff);
+
+ rp++;
+ }
+
+ for (i = 0; i < istop; i++)
+ {
+ *rp = (png_byte)(((int)(*rp) +
+ (int)(*pp++ + *(rp-bpp)) / 2 ) & 0xff);
+
+ rp++;
+ }
+}
+
+static void
+png_read_filter_row_paeth_1byte_pixel(png_row_infop row_info, png_bytep row,
+ png_const_bytep prev_row)
+{
+ png_bytep rp_end = row + row_info->rowbytes;
+ int a, c;
+
+ /* First pixel/byte */
+ c = *prev_row++;
+ a = *row + c;
+ *row++ = (png_byte)a;
+
+ /* Remainder */
+ while (row < rp_end)
+ {
+ int b, pa, pb, pc, p;
+
+ a &= 0xff; /* From previous iteration or start */
+ b = *prev_row++;
+
+ p = b - c;
+ pc = a - c;
+
+#ifdef PNG_USE_ABS
+ pa = abs(p);
+ pb = abs(pc);
+ pc = abs(p + pc);
+#else
+ pa = p < 0 ? -p : p;
+ pb = pc < 0 ? -pc : pc;
+ pc = (p + pc) < 0 ? -(p + pc) : p + pc;
+#endif
+
+ /* Find the best predictor, the least of pa, pb, pc favoring the earlier
+ * ones in the case of a tie.
+ */
+ if (pb < pa) pa = pb, a = b;
+ if (pc < pa) a = c;
+
+ /* Calculate the current pixel in a, and move the previous row pixel to c
+ * for the next time round the loop
+ */
+ c = b;
+ a += *row;
+ *row++ = (png_byte)a;
+ }
+}
+
+static void
+png_read_filter_row_paeth_multibyte_pixel(png_row_infop row_info, png_bytep row,
+ png_const_bytep prev_row)
+{
+ int bpp = (row_info->pixel_depth + 7) >> 3;
+ png_bytep rp_end = row + bpp;
+
+ /* Process the first pixel in the row completely (this is the same as 'up'
+ * because there is only one candidate predictor for the first row).
+ */
+ while (row < rp_end)
+ {
+ int a = *row + *prev_row++;
+ *row++ = (png_byte)a;
+ }
+
+ /* Remainder */
+ rp_end += row_info->rowbytes - bpp;
+
+ while (row < rp_end)
+ {
+ int a, b, c, pa, pb, pc, p;
+
+ c = *(prev_row - bpp);
+ a = *(row - bpp);
+ b = *prev_row++;
+
+ p = b - c;
+ pc = a - c;
+
+#ifdef PNG_USE_ABS
+ pa = abs(p);
+ pb = abs(pc);
+ pc = abs(p + pc);
+#else
+ pa = p < 0 ? -p : p;
+ pb = pc < 0 ? -pc : pc;
+ pc = (p + pc) < 0 ? -(p + pc) : p + pc;
+#endif
+
+ if (pb < pa) pa = pb, a = b;
+ if (pc < pa) a = c;
+
+ a += *row;
+ *row++ = (png_byte)a;
+ }
+}
+
+static void
+png_init_filter_functions(png_structrp pp)
+ /* This function is called once for every PNG image (except for PNG images
+ * that only use PNG_FILTER_VALUE_NONE for all rows) to set the
+ * implementations required to reverse the filtering of PNG rows. Reversing
+ * the filter is the first transformation performed on the row data. It is
+ * performed in place, therefore an implementation can be selected based on
+ * the image pixel format. If the implementation depends on image width then
+ * take care to ensure that it works correctly if the image is interlaced -
+ * interlacing causes the actual row width to vary.
+ */
+{
+ unsigned int bpp = (pp->pixel_depth + 7) >> 3;
+
+ pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub;
+ pp->read_filter[PNG_FILTER_VALUE_UP-1] = png_read_filter_row_up;
+ pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg;
+ if (bpp == 1)
+ pp->read_filter[PNG_FILTER_VALUE_PAETH-1] =
+ png_read_filter_row_paeth_1byte_pixel;
+ else
+ pp->read_filter[PNG_FILTER_VALUE_PAETH-1] =
+ png_read_filter_row_paeth_multibyte_pixel;
+
+#ifdef PNG_FILTER_OPTIMIZATIONS
+ /* To use this define PNG_FILTER_OPTIMIZATIONS as the name of a function to
+ * call to install hardware optimizations for the above functions; simply
+ * replace whatever elements of the pp->read_filter[] array with a hardware
+ * specific (or, for that matter, generic) optimization.
+ *
+ * To see an example of this examine what configure.ac does when
+ * --enable-arm-neon is specified on the command line.
+ */
+ PNG_FILTER_OPTIMIZATIONS(pp, bpp);
+#endif
+}
+
+void /* PRIVATE */
+png_read_filter_row(png_structrp pp, png_row_infop row_info, png_bytep row,
+ png_const_bytep prev_row, int filter)
+{
+ /* OPTIMIZATION: DO NOT MODIFY THIS FUNCTION, instead #define
+ * PNG_FILTER_OPTIMIZATIONS to a function that overrides the generic
+ * implementations. See png_init_filter_functions above.
+ */
+ if (filter > PNG_FILTER_VALUE_NONE && filter < PNG_FILTER_VALUE_LAST)
+ {
+ if (pp->read_filter[0] == NULL)
+ png_init_filter_functions(pp);
+
+ pp->read_filter[filter-1](row_info, row, prev_row);
+ }
+}
+
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+void /* PRIVATE */
+png_read_IDAT_data(png_structrp png_ptr, png_bytep output,
+ png_alloc_size_t avail_out)
+{
+ /* Loop reading IDATs and decompressing the result into output[avail_out] */
+ png_ptr->zstream.next_out = output;
+ png_ptr->zstream.avail_out = 0; /* safety: set below */
+
+ if (output == NULL)
+ avail_out = 0;
+
+ do
+ {
+ int ret;
+ png_byte tmpbuf[PNG_INFLATE_BUF_SIZE];
+
+ if (png_ptr->zstream.avail_in == 0)
+ {
+ uInt avail_in;
+ png_bytep buffer;
+
+ while (png_ptr->idat_size == 0)
+ {
+ png_crc_finish(png_ptr, 0);
+
+ png_ptr->idat_size = png_read_chunk_header(png_ptr);
+ /* This is an error even in the 'check' case because the code just
+ * consumed a non-IDAT header.
+ */
+ if (png_ptr->chunk_name != png_IDAT)
+ png_error(png_ptr, "Not enough image data");
+ }
+
+ avail_in = png_ptr->IDAT_read_size;
+
+ if (avail_in > png_ptr->idat_size)
+ avail_in = (uInt)png_ptr->idat_size;
+
+ /* A PNG with a gradually increasing IDAT size will defeat this attempt
+ * to minimize memory usage by causing lots of re-allocs, but
+ * realistically doing IDAT_read_size re-allocs is not likely to be a
+ * big problem.
+ */
+ buffer = png_read_buffer(png_ptr, avail_in, 0/*error*/);
+
+ png_crc_read(png_ptr, buffer, avail_in);
+ png_ptr->idat_size -= avail_in;
+
+ png_ptr->zstream.next_in = buffer;
+ png_ptr->zstream.avail_in = avail_in;
+ }
+
+ /* And set up the output side. */
+ if (output != NULL) /* standard read */
+ {
+ uInt out = ZLIB_IO_MAX;
+
+ if (out > avail_out)
+ out = (uInt)avail_out;
+
+ avail_out -= out;
+ png_ptr->zstream.avail_out = out;
+ }
+
+ else /* after last row, checking for end */
+ {
+ png_ptr->zstream.next_out = tmpbuf;
+ png_ptr->zstream.avail_out = (sizeof tmpbuf);
+ }
+
+ /* Use NO_FLUSH; this gives zlib the maximum opportunity to optimize the
+ * process. If the LZ stream is truncated the sequential reader will
+ * terminally damage the stream, above, by reading the chunk header of the
+ * following chunk (it then exits with png_error).
+ *
+ * TODO: deal more elegantly with truncated IDAT lists.
+ */
+ ret = PNG_INFLATE(png_ptr, Z_NO_FLUSH);
+
+ /* Take the unconsumed output back. */
+ if (output != NULL)
+ avail_out += png_ptr->zstream.avail_out;
+
+ else /* avail_out counts the extra bytes */
+ avail_out += (sizeof tmpbuf) - png_ptr->zstream.avail_out;
+
+ png_ptr->zstream.avail_out = 0;
+
+ if (ret == Z_STREAM_END)
+ {
+ /* Do this for safety; we won't read any more into this row. */
+ png_ptr->zstream.next_out = NULL;
+
+ png_ptr->mode |= PNG_AFTER_IDAT;
+ png_ptr->flags |= PNG_FLAG_ZSTREAM_ENDED;
+
+ if (png_ptr->zstream.avail_in > 0 || png_ptr->idat_size > 0)
+ png_chunk_benign_error(png_ptr, "Extra compressed data");
+ break;
+ }
+
+ if (ret != Z_OK)
+ {
+ png_zstream_error(png_ptr, ret);
+
+ if (output != NULL)
+ png_chunk_error(png_ptr, png_ptr->zstream.msg);
+
+ else /* checking */
+ {
+ png_chunk_benign_error(png_ptr, png_ptr->zstream.msg);
+ return;
+ }
+ }
+ } while (avail_out > 0);
+
+ if (avail_out > 0)
+ {
+ /* The stream ended before the image; this is the same as too few IDATs so
+ * should be handled the same way.
+ */
+ if (output != NULL)
+ png_error(png_ptr, "Not enough image data");
+
+ else /* the deflate stream contained extra data */
+ png_chunk_benign_error(png_ptr, "Too much image data");
+ }
+}
+
+void /* PRIVATE */
+png_read_finish_IDAT(png_structrp png_ptr)
+{
+ /* We don't need any more data and the stream should have ended, however the
+ * LZ end code may actually not have been processed. In this case we must
+ * read it otherwise stray unread IDAT data or, more likely, an IDAT chunk
+ * may still remain to be consumed.
+ */
+ if ((png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED) == 0)
+ {
+ /* The NULL causes png_read_IDAT_data to swallow any remaining bytes in
+ * the compressed stream, but the stream may be damaged too, so even after
+ * this call we may need to terminate the zstream ownership.
+ */
+ png_read_IDAT_data(png_ptr, NULL, 0);
+ png_ptr->zstream.next_out = NULL; /* safety */
+
+ /* Now clear everything out for safety; the following may not have been
+ * done.
+ */
+ if ((png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED) == 0)
+ {
+ png_ptr->mode |= PNG_AFTER_IDAT;
+ png_ptr->flags |= PNG_FLAG_ZSTREAM_ENDED;
+ }
+ }
+
+ /* If the zstream has not been released do it now *and* terminate the reading
+ * of the final IDAT chunk.
+ */
+ if (png_ptr->zowner == png_IDAT)
+ {
+ /* Always do this; the pointers otherwise point into the read buffer. */
+ png_ptr->zstream.next_in = NULL;
+ png_ptr->zstream.avail_in = 0;
+
+ /* Now we no longer own the zstream. */
+ png_ptr->zowner = 0;
+
+ /* The slightly weird semantics of the sequential IDAT reading is that we
+ * are always in or at the end of an IDAT chunk, so we always need to do a
+ * crc_finish here. If idat_size is non-zero we also need to read the
+ * spurious bytes at the end of the chunk now.
+ */
+ (void)png_crc_finish(png_ptr, png_ptr->idat_size);
+ }
+}
+
+void /* PRIVATE */
+png_read_finish_row(png_structrp png_ptr)
+{
+ /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
+
+ /* Start of interlace block */
+ static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
+
+ /* Offset to next interlace block */
+ static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
+
+ /* Start of interlace block in the y direction */
+ static PNG_CONST png_byte png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
+
+ /* Offset to next interlace block in the y direction */
+ static PNG_CONST png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
+
+ png_debug(1, "in png_read_finish_row");
+ png_ptr->row_number++;
+ if (png_ptr->row_number < png_ptr->num_rows)
+ return;
+
+ if (png_ptr->interlaced != 0)
+ {
+ png_ptr->row_number = 0;
+
+ /* TO DO: don't do this if prev_row isn't needed (requires
+ * read-ahead of the next row's filter byte.
+ */
+ memset(png_ptr->prev_row, 0, png_ptr->rowbytes + 1);
+
+ do
+ {
+ png_ptr->pass++;
+
+ if (png_ptr->pass >= 7)
+ break;
+
+ png_ptr->iwidth = (png_ptr->width +
+ png_pass_inc[png_ptr->pass] - 1 -
+ png_pass_start[png_ptr->pass]) /
+ png_pass_inc[png_ptr->pass];
+
+ if ((png_ptr->transformations & PNG_INTERLACE) == 0)
+ {
+ png_ptr->num_rows = (png_ptr->height +
+ png_pass_yinc[png_ptr->pass] - 1 -
+ png_pass_ystart[png_ptr->pass]) /
+ png_pass_yinc[png_ptr->pass];
+ }
+
+ else /* if (png_ptr->transformations & PNG_INTERLACE) */
+ break; /* libpng deinterlacing sees every row */
+
+ } while (png_ptr->num_rows == 0 || png_ptr->iwidth == 0);
+
+ if (png_ptr->pass < 7)
+ return;
+ }
+
+ /* Here after at the end of the last row of the last pass. */
+ png_read_finish_IDAT(png_ptr);
+}
+#endif /* SEQUENTIAL_READ */
+
+void /* PRIVATE */
+png_read_start_row(png_structrp png_ptr)
+{
+ /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
+
+ /* Start of interlace block */
+ static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
+
+ /* Offset to next interlace block */
+ static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
+
+ /* Start of interlace block in the y direction */
+ static PNG_CONST png_byte png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
+
+ /* Offset to next interlace block in the y direction */
+ static PNG_CONST png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
+
+ int max_pixel_depth;
+ png_size_t row_bytes;
+
+ png_debug(1, "in png_read_start_row");
+
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
+ png_init_read_transformations(png_ptr);
+#endif
+ if (png_ptr->interlaced != 0)
+ {
+ if ((png_ptr->transformations & PNG_INTERLACE) == 0)
+ png_ptr->num_rows = (png_ptr->height + png_pass_yinc[0] - 1 -
+ png_pass_ystart[0]) / png_pass_yinc[0];
+
+ else
+ png_ptr->num_rows = png_ptr->height;
+
+ png_ptr->iwidth = (png_ptr->width +
+ png_pass_inc[png_ptr->pass] - 1 -
+ png_pass_start[png_ptr->pass]) /
+ png_pass_inc[png_ptr->pass];
+ }
+
+ else
+ {
+ png_ptr->num_rows = png_ptr->height;
+ png_ptr->iwidth = png_ptr->width;
+ }
+
+ max_pixel_depth = png_ptr->pixel_depth;
+
+ /* WARNING: * png_read_transform_info (pngrtran.c) performs a simpler set of
+ * calculations to calculate the final pixel depth, then
+ * png_do_read_transforms actually does the transforms. This means that the
+ * code which effectively calculates this value is actually repeated in three
+ * separate places. They must all match. Innocent changes to the order of
+ * transformations can and will break libpng in a way that causes memory
+ * overwrites.
+ *
+ * TODO: fix this.
+ */
+#ifdef PNG_READ_PACK_SUPPORTED
+ if ((png_ptr->transformations & PNG_PACK) != 0 && png_ptr->bit_depth < 8)
+ max_pixel_depth = 8;
+#endif
+
+#ifdef PNG_READ_EXPAND_SUPPORTED
+ if ((png_ptr->transformations & PNG_EXPAND) != 0)
+ {
+ if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+ {
+ if (png_ptr->num_trans != 0)
+ max_pixel_depth = 32;
+
+ else
+ max_pixel_depth = 24;
+ }
+
+ else if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY)
+ {
+ if (max_pixel_depth < 8)
+ max_pixel_depth = 8;
+
+ if (png_ptr->num_trans != 0)
+ max_pixel_depth *= 2;
+ }
+
+ else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB)
+ {
+ if (png_ptr->num_trans != 0)
+ {
+ max_pixel_depth *= 4;
+ max_pixel_depth /= 3;
+ }
+ }
+ }
+#endif
+
+#ifdef PNG_READ_EXPAND_16_SUPPORTED
+ if ((png_ptr->transformations & PNG_EXPAND_16) != 0)
+ {
+# ifdef PNG_READ_EXPAND_SUPPORTED
+ /* In fact it is an error if it isn't supported, but checking is
+ * the safe way.
+ */
+ if ((png_ptr->transformations & PNG_EXPAND) != 0)
+ {
+ if (png_ptr->bit_depth < 16)
+ max_pixel_depth *= 2;
+ }
+ else
+# endif
+ png_ptr->transformations &= ~PNG_EXPAND_16;
+ }
+#endif
+
+#ifdef PNG_READ_FILLER_SUPPORTED
+ if ((png_ptr->transformations & (PNG_FILLER)) != 0)
+ {
+ if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY)
+ {
+ if (max_pixel_depth <= 8)
+ max_pixel_depth = 16;
+
+ else
+ max_pixel_depth = 32;
+ }
+
+ else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB ||
+ png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+ {
+ if (max_pixel_depth <= 32)
+ max_pixel_depth = 32;
+
+ else
+ max_pixel_depth = 64;
+ }
+ }
+#endif
+
+#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
+ if ((png_ptr->transformations & PNG_GRAY_TO_RGB) != 0)
+ {
+ if (
+#ifdef PNG_READ_EXPAND_SUPPORTED
+ (png_ptr->num_trans != 0 &&
+ (png_ptr->transformations & PNG_EXPAND) != 0) ||
+#endif
+#ifdef PNG_READ_FILLER_SUPPORTED
+ (png_ptr->transformations & (PNG_FILLER)) != 0 ||
+#endif
+ png_ptr->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+ {
+ if (max_pixel_depth <= 16)
+ max_pixel_depth = 32;
+
+ else
+ max_pixel_depth = 64;
+ }
+
+ else
+ {
+ if (max_pixel_depth <= 8)
+ {
+ if (png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+ max_pixel_depth = 32;
+
+ else
+ max_pixel_depth = 24;
+ }
+
+ else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+ max_pixel_depth = 64;
+
+ else
+ max_pixel_depth = 48;
+ }
+ }
+#endif
+
+#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) && \
+defined(PNG_USER_TRANSFORM_PTR_SUPPORTED)
+ if ((png_ptr->transformations & PNG_USER_TRANSFORM) != 0)
+ {
+ int user_pixel_depth = png_ptr->user_transform_depth *
+ png_ptr->user_transform_channels;
+
+ if (user_pixel_depth > max_pixel_depth)
+ max_pixel_depth = user_pixel_depth;
+ }
+#endif
+
+ /* This value is stored in png_struct and double checked in the row read
+ * code.
+ */
+ png_ptr->maximum_pixel_depth = (png_byte)max_pixel_depth;
+ png_ptr->transformed_pixel_depth = 0; /* calculated on demand */
+
+ /* Align the width on the next larger 8 pixels. Mainly used
+ * for interlacing
+ */
+ row_bytes = ((png_ptr->width + 7) & ~((png_uint_32)7));
+ /* Calculate the maximum bytes needed, adding a byte and a pixel
+ * for safety's sake
+ */
+ row_bytes = PNG_ROWBYTES(max_pixel_depth, row_bytes) +
+ 1 + ((max_pixel_depth + 7) >> 3);
+
+#ifdef PNG_MAX_MALLOC_64K
+ if (row_bytes > (png_uint_32)65536L)
+ png_error(png_ptr, "This image requires a row greater than 64KB");
+#endif
+
+ if (row_bytes + 48 > png_ptr->old_big_row_buf_size)
+ {
+ png_free(png_ptr, png_ptr->big_row_buf);
+ png_free(png_ptr, png_ptr->big_prev_row);
+
+ if (png_ptr->interlaced != 0)
+ png_ptr->big_row_buf = (png_bytep)png_calloc(png_ptr,
+ row_bytes + 48);
+
+ else
+ png_ptr->big_row_buf = (png_bytep)png_malloc(png_ptr, row_bytes + 48);
+
+ png_ptr->big_prev_row = (png_bytep)png_malloc(png_ptr, row_bytes + 48);
+
+#ifdef PNG_ALIGNED_MEMORY_SUPPORTED
+ /* Use 16-byte aligned memory for row_buf with at least 16 bytes
+ * of padding before and after row_buf; treat prev_row similarly.
+ * NOTE: the alignment is to the start of the pixels, one beyond the start
+ * of the buffer, because of the filter byte. Prior to libpng 1.5.6 this
+ * was incorrect; the filter byte was aligned, which had the exact
+ * opposite effect of that intended.
+ */
+ {
+ png_bytep temp = png_ptr->big_row_buf + 32;
+ int extra = (int)((temp - (png_bytep)0) & 0x0f);
+ png_ptr->row_buf = temp - extra - 1/*filter byte*/;
+
+ temp = png_ptr->big_prev_row + 32;
+ extra = (int)((temp - (png_bytep)0) & 0x0f);
+ png_ptr->prev_row = temp - extra - 1/*filter byte*/;
+ }
+
+#else
+ /* Use 31 bytes of padding before and 17 bytes after row_buf. */
+ png_ptr->row_buf = png_ptr->big_row_buf + 31;
+ png_ptr->prev_row = png_ptr->big_prev_row + 31;
+#endif
+ png_ptr->old_big_row_buf_size = row_bytes + 48;
+ }
+
+#ifdef PNG_MAX_MALLOC_64K
+ if (png_ptr->rowbytes > 65535)
+ png_error(png_ptr, "This image requires a row greater than 64KB");
+
+#endif
+ if (png_ptr->rowbytes > (PNG_SIZE_MAX - 1))
+ png_error(png_ptr, "Row has too many bytes to allocate in memory");
+
+ memset(png_ptr->prev_row, 0, png_ptr->rowbytes + 1);
+
+ png_debug1(3, "width = %u,", png_ptr->width);
+ png_debug1(3, "height = %u,", png_ptr->height);
+ png_debug1(3, "iwidth = %u,", png_ptr->iwidth);
+ png_debug1(3, "num_rows = %u,", png_ptr->num_rows);
+ png_debug1(3, "rowbytes = %lu,", (unsigned long)png_ptr->rowbytes);
+ png_debug1(3, "irowbytes = %lu",
+ (unsigned long)PNG_ROWBYTES(png_ptr->pixel_depth, png_ptr->iwidth) + 1);
+
+ /* The sequential reader needs a buffer for IDAT, but the progressive reader
+ * does not, so free the read buffer now regardless; the sequential reader
+ * reallocates it on demand.
+ */
+ if (png_ptr->read_buffer != 0)
+ {
+ png_bytep buffer = png_ptr->read_buffer;
+
+ png_ptr->read_buffer_size = 0;
+ png_ptr->read_buffer = NULL;
+ png_free(png_ptr, buffer);
+ }
+
+ /* Finally claim the zstream for the inflate of the IDAT data, use the bits
+ * value from the stream (note that this will result in a fatal error if the
+ * IDAT stream has a bogus deflate header window_bits value, but this should
+ * not be happening any longer!)
+ */
+ if (png_inflate_claim(png_ptr, png_IDAT) != Z_OK)
+ png_error(png_ptr, png_ptr->zstream.msg);
+
+ png_ptr->flags |= PNG_FLAG_ROW_INIT;
+}
+#endif /* READ */
diff --git a/third_party/lpng_v163/pngset.c b/third_party/libpng/pngset.c
similarity index 91%
rename from third_party/lpng_v163/pngset.c
rename to third_party/libpng/pngset.c
index b479052..8fd7965 100644
--- a/third_party/lpng_v163/pngset.c
+++ b/third_party/libpng/pngset.c
@@ -1,1596 +1,1647 @@
-/* pngset.c - storage of image information into info struct
- *
- * Last changed in libpng 1.6.3 [July 18, 2013]
- * Copyright (c) 1998-2013 Glenn Randers-Pehrson
- * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
- * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
- *
- * This code is released under the libpng license.
- * For conditions of distribution and use, see the disclaimer
- * and license in png.h
- *
- * The functions here are used during reads to store data from the file
- * into the info struct, and during writes to store application data
- * into the info struct for writing into the file. This abstracts the
- * info struct and allows us to change the structure in the future.
- */
-
-#include "pngpriv.h"
-
-#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
-
-#ifdef PNG_bKGD_SUPPORTED
-void PNGAPI
-png_set_bKGD(png_const_structrp png_ptr, png_inforp info_ptr,
- png_const_color_16p background)
-{
- png_debug1(1, "in %s storage function", "bKGD");
-
- if (png_ptr == NULL || info_ptr == NULL || background == NULL)
- return;
-
- info_ptr->background = *background;
- info_ptr->valid |= PNG_INFO_bKGD;
-}
-#endif
-
-#ifdef PNG_cHRM_SUPPORTED
-void PNGFAPI
-png_set_cHRM_fixed(png_const_structrp png_ptr, png_inforp info_ptr,
- png_fixed_point white_x, png_fixed_point white_y, png_fixed_point red_x,
- png_fixed_point red_y, png_fixed_point green_x, png_fixed_point green_y,
- png_fixed_point blue_x, png_fixed_point blue_y)
-{
- png_xy xy;
-
- png_debug1(1, "in %s storage function", "cHRM fixed");
-
- if (png_ptr == NULL || info_ptr == NULL)
- return;
-
- xy.redx = red_x;
- xy.redy = red_y;
- xy.greenx = green_x;
- xy.greeny = green_y;
- xy.bluex = blue_x;
- xy.bluey = blue_y;
- xy.whitex = white_x;
- xy.whitey = white_y;
-
- if (png_colorspace_set_chromaticities(png_ptr, &info_ptr->colorspace, &xy,
- 2/* override with app values*/))
- info_ptr->colorspace.flags |= PNG_COLORSPACE_FROM_cHRM;
-
- png_colorspace_sync_info(png_ptr, info_ptr);
-}
-
-void PNGFAPI
-png_set_cHRM_XYZ_fixed(png_const_structrp png_ptr, png_inforp info_ptr,
- png_fixed_point int_red_X, png_fixed_point int_red_Y,
- png_fixed_point int_red_Z, png_fixed_point int_green_X,
- png_fixed_point int_green_Y, png_fixed_point int_green_Z,
- png_fixed_point int_blue_X, png_fixed_point int_blue_Y,
- png_fixed_point int_blue_Z)
-{
- png_XYZ XYZ;
-
- png_debug1(1, "in %s storage function", "cHRM XYZ fixed");
-
- if (png_ptr == NULL || info_ptr == NULL)
- return;
-
- XYZ.red_X = int_red_X;
- XYZ.red_Y = int_red_Y;
- XYZ.red_Z = int_red_Z;
- XYZ.green_X = int_green_X;
- XYZ.green_Y = int_green_Y;
- XYZ.green_Z = int_green_Z;
- XYZ.blue_X = int_blue_X;
- XYZ.blue_Y = int_blue_Y;
- XYZ.blue_Z = int_blue_Z;
-
- if (png_colorspace_set_endpoints(png_ptr, &info_ptr->colorspace, &XYZ, 2))
- info_ptr->colorspace.flags |= PNG_COLORSPACE_FROM_cHRM;
-
- png_colorspace_sync_info(png_ptr, info_ptr);
-}
-
-# ifdef PNG_FLOATING_POINT_SUPPORTED
-void PNGAPI
-png_set_cHRM(png_const_structrp png_ptr, png_inforp info_ptr,
- double white_x, double white_y, double red_x, double red_y,
- double green_x, double green_y, double blue_x, double blue_y)
-{
- png_set_cHRM_fixed(png_ptr, info_ptr,
- png_fixed(png_ptr, white_x, "cHRM White X"),
- png_fixed(png_ptr, white_y, "cHRM White Y"),
- png_fixed(png_ptr, red_x, "cHRM Red X"),
- png_fixed(png_ptr, red_y, "cHRM Red Y"),
- png_fixed(png_ptr, green_x, "cHRM Green X"),
- png_fixed(png_ptr, green_y, "cHRM Green Y"),
- png_fixed(png_ptr, blue_x, "cHRM Blue X"),
- png_fixed(png_ptr, blue_y, "cHRM Blue Y"));
-}
-
-void PNGAPI
-png_set_cHRM_XYZ(png_const_structrp png_ptr, png_inforp info_ptr, double red_X,
- double red_Y, double red_Z, double green_X, double green_Y, double green_Z,
- double blue_X, double blue_Y, double blue_Z)
-{
- png_set_cHRM_XYZ_fixed(png_ptr, info_ptr,
- png_fixed(png_ptr, red_X, "cHRM Red X"),
- png_fixed(png_ptr, red_Y, "cHRM Red Y"),
- png_fixed(png_ptr, red_Z, "cHRM Red Z"),
- png_fixed(png_ptr, green_X, "cHRM Red X"),
- png_fixed(png_ptr, green_Y, "cHRM Red Y"),
- png_fixed(png_ptr, green_Z, "cHRM Red Z"),
- png_fixed(png_ptr, blue_X, "cHRM Red X"),
- png_fixed(png_ptr, blue_Y, "cHRM Red Y"),
- png_fixed(png_ptr, blue_Z, "cHRM Red Z"));
-}
-# endif /* PNG_FLOATING_POINT_SUPPORTED */
-
-#endif /* PNG_cHRM_SUPPORTED */
-
-#ifdef PNG_gAMA_SUPPORTED
-void PNGFAPI
-png_set_gAMA_fixed(png_const_structrp png_ptr, png_inforp info_ptr,
- png_fixed_point file_gamma)
-{
- png_debug1(1, "in %s storage function", "gAMA");
-
- if (png_ptr == NULL || info_ptr == NULL)
- return;
-
- png_colorspace_set_gamma(png_ptr, &info_ptr->colorspace, file_gamma);
- png_colorspace_sync_info(png_ptr, info_ptr);
-}
-
-# ifdef PNG_FLOATING_POINT_SUPPORTED
-void PNGAPI
-png_set_gAMA(png_const_structrp png_ptr, png_inforp info_ptr, double file_gamma)
-{
- png_set_gAMA_fixed(png_ptr, info_ptr, png_fixed(png_ptr, file_gamma,
- "png_set_gAMA"));
-}
-# endif
-#endif
-
-#ifdef PNG_hIST_SUPPORTED
-void PNGAPI
-png_set_hIST(png_const_structrp png_ptr, png_inforp info_ptr,
- png_const_uint_16p hist)
-{
- int i;
-
- png_debug1(1, "in %s storage function", "hIST");
-
- if (png_ptr == NULL || info_ptr == NULL)
- return;
-
- if (info_ptr->num_palette == 0 || info_ptr->num_palette
- > PNG_MAX_PALETTE_LENGTH)
- {
- png_warning(png_ptr,
- "Invalid palette size, hIST allocation skipped");
-
- return;
- }
-
- png_free_data(png_ptr, info_ptr, PNG_FREE_HIST, 0);
-
- /* Changed from info->num_palette to PNG_MAX_PALETTE_LENGTH in
- * version 1.2.1
- */
- info_ptr->hist = png_voidcast(png_uint_16p, png_malloc_warn(png_ptr,
- PNG_MAX_PALETTE_LENGTH * (sizeof (png_uint_16))));
-
- if (info_ptr->hist == NULL)
- {
- png_warning(png_ptr, "Insufficient memory for hIST chunk data");
- return;
- }
-
- info_ptr->free_me |= PNG_FREE_HIST;
-
- for (i = 0; i < info_ptr->num_palette; i++)
- info_ptr->hist[i] = hist[i];
-
- info_ptr->valid |= PNG_INFO_hIST;
-}
-#endif
-
-void PNGAPI
-png_set_IHDR(png_const_structrp png_ptr, png_inforp info_ptr,
- png_uint_32 width, png_uint_32 height, int bit_depth,
- int color_type, int interlace_type, int compression_type,
- int filter_type)
-{
- png_debug1(1, "in %s storage function", "IHDR");
-
- if (png_ptr == NULL || info_ptr == NULL)
- return;
-
- info_ptr->width = width;
- info_ptr->height = height;
- info_ptr->bit_depth = (png_byte)bit_depth;
- info_ptr->color_type = (png_byte)color_type;
- info_ptr->compression_type = (png_byte)compression_type;
- info_ptr->filter_type = (png_byte)filter_type;
- info_ptr->interlace_type = (png_byte)interlace_type;
-
- png_check_IHDR (png_ptr, info_ptr->width, info_ptr->height,
- info_ptr->bit_depth, info_ptr->color_type, info_ptr->interlace_type,
- info_ptr->compression_type, info_ptr->filter_type);
-
- if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
- info_ptr->channels = 1;
-
- else if (info_ptr->color_type & PNG_COLOR_MASK_COLOR)
- info_ptr->channels = 3;
-
- else
- info_ptr->channels = 1;
-
- if (info_ptr->color_type & PNG_COLOR_MASK_ALPHA)
- info_ptr->channels++;
-
- info_ptr->pixel_depth = (png_byte)(info_ptr->channels * info_ptr->bit_depth);
-
- info_ptr->rowbytes = PNG_ROWBYTES(info_ptr->pixel_depth, width);
-}
-
-#ifdef PNG_oFFs_SUPPORTED
-void PNGAPI
-png_set_oFFs(png_const_structrp png_ptr, png_inforp info_ptr,
- png_int_32 offset_x, png_int_32 offset_y, int unit_type)
-{
- png_debug1(1, "in %s storage function", "oFFs");
-
- if (png_ptr == NULL || info_ptr == NULL)
- return;
-
- info_ptr->x_offset = offset_x;
- info_ptr->y_offset = offset_y;
- info_ptr->offset_unit_type = (png_byte)unit_type;
- info_ptr->valid |= PNG_INFO_oFFs;
-}
-#endif
-
-#ifdef PNG_pCAL_SUPPORTED
-void PNGAPI
-png_set_pCAL(png_const_structrp png_ptr, png_inforp info_ptr,
- png_const_charp purpose, png_int_32 X0, png_int_32 X1, int type,
- int nparams, png_const_charp units, png_charpp params)
-{
- png_size_t length;
- int i;
-
- png_debug1(1, "in %s storage function", "pCAL");
-
- if (png_ptr == NULL || info_ptr == NULL || purpose == NULL || units == NULL
- || (nparams > 0 && params == NULL))
- return;
-
- length = strlen(purpose) + 1;
- png_debug1(3, "allocating purpose for info (%lu bytes)",
- (unsigned long)length);
-
- /* TODO: validate format of calibration name and unit name */
-
- /* Check that the type matches the specification. */
- if (type < 0 || type > 3)
- png_error(png_ptr, "Invalid pCAL equation type");
-
- if (nparams < 0 || nparams > 255)
- png_error(png_ptr, "Invalid pCAL parameter count");
-
- /* Validate params[nparams] */
- for (i=0; i<nparams; ++i)
- if (params[i] == NULL ||
- !png_check_fp_string(params[i], strlen(params[i])))
- png_error(png_ptr, "Invalid format for pCAL parameter");
-
- info_ptr->pcal_purpose = png_voidcast(png_charp,
- png_malloc_warn(png_ptr, length));
-
- if (info_ptr->pcal_purpose == NULL)
- {
- png_warning(png_ptr, "Insufficient memory for pCAL purpose");
- return;
- }
-
- memcpy(info_ptr->pcal_purpose, purpose, length);
-
- png_debug(3, "storing X0, X1, type, and nparams in info");
- info_ptr->pcal_X0 = X0;
- info_ptr->pcal_X1 = X1;
- info_ptr->pcal_type = (png_byte)type;
- info_ptr->pcal_nparams = (png_byte)nparams;
-
- length = strlen(units) + 1;
- png_debug1(3, "allocating units for info (%lu bytes)",
- (unsigned long)length);
-
- info_ptr->pcal_units = png_voidcast(png_charp,
- png_malloc_warn(png_ptr, length));
-
- if (info_ptr->pcal_units == NULL)
- {
- png_warning(png_ptr, "Insufficient memory for pCAL units");
- return;
- }
-
- memcpy(info_ptr->pcal_units, units, length);
-
- info_ptr->pcal_params = png_voidcast(png_charpp, png_malloc_warn(png_ptr,
- (png_size_t)((nparams + 1) * (sizeof (png_charp)))));
-
- if (info_ptr->pcal_params == NULL)
- {
- png_warning(png_ptr, "Insufficient memory for pCAL params");
- return;
- }
-
- memset(info_ptr->pcal_params, 0, (nparams + 1) * (sizeof (png_charp)));
-
- for (i = 0; i < nparams; i++)
- {
- length = strlen(params[i]) + 1;
- png_debug2(3, "allocating parameter %d for info (%lu bytes)", i,
- (unsigned long)length);
-
- info_ptr->pcal_params[i] = (png_charp)png_malloc_warn(png_ptr, length);
-
- if (info_ptr->pcal_params[i] == NULL)
- {
- png_warning(png_ptr, "Insufficient memory for pCAL parameter");
- return;
- }
-
- memcpy(info_ptr->pcal_params[i], params[i], length);
- }
-
- info_ptr->valid |= PNG_INFO_pCAL;
- info_ptr->free_me |= PNG_FREE_PCAL;
-}
-#endif
-
-#ifdef PNG_sCAL_SUPPORTED
-void PNGAPI
-png_set_sCAL_s(png_const_structrp png_ptr, png_inforp info_ptr,
- int unit, png_const_charp swidth, png_const_charp sheight)
-{
- png_size_t lengthw = 0, lengthh = 0;
-
- png_debug1(1, "in %s storage function", "sCAL");
-
- if (png_ptr == NULL || info_ptr == NULL)
- return;
-
- /* Double check the unit (should never get here with an invalid
- * unit unless this is an API call.)
- */
- if (unit != 1 && unit != 2)
- png_error(png_ptr, "Invalid sCAL unit");
-
- if (swidth == NULL || (lengthw = strlen(swidth)) == 0 ||
- swidth[0] == 45 /* '-' */ || !png_check_fp_string(swidth, lengthw))
- png_error(png_ptr, "Invalid sCAL width");
-
- if (sheight == NULL || (lengthh = strlen(sheight)) == 0 ||
- sheight[0] == 45 /* '-' */ || !png_check_fp_string(sheight, lengthh))
- png_error(png_ptr, "Invalid sCAL height");
-
- info_ptr->scal_unit = (png_byte)unit;
-
- ++lengthw;
-
- png_debug1(3, "allocating unit for info (%u bytes)", (unsigned int)lengthw);
-
- info_ptr->scal_s_width = png_voidcast(png_charp,
- png_malloc_warn(png_ptr, lengthw));
-
- if (info_ptr->scal_s_width == NULL)
- {
- png_warning(png_ptr, "Memory allocation failed while processing sCAL");
- return;
- }
-
- memcpy(info_ptr->scal_s_width, swidth, lengthw);
-
- ++lengthh;
-
- png_debug1(3, "allocating unit for info (%u bytes)", (unsigned int)lengthh);
-
- info_ptr->scal_s_height = png_voidcast(png_charp,
- png_malloc_warn(png_ptr, lengthh));
-
- if (info_ptr->scal_s_height == NULL)
- {
- png_free (png_ptr, info_ptr->scal_s_width);
- info_ptr->scal_s_width = NULL;
-
- png_warning(png_ptr, "Memory allocation failed while processing sCAL");
- return;
- }
-
- memcpy(info_ptr->scal_s_height, sheight, lengthh);
-
- info_ptr->valid |= PNG_INFO_sCAL;
- info_ptr->free_me |= PNG_FREE_SCAL;
-}
-
-# ifdef PNG_FLOATING_POINT_SUPPORTED
-void PNGAPI
-png_set_sCAL(png_const_structrp png_ptr, png_inforp info_ptr, int unit,
- double width, double height)
-{
- png_debug1(1, "in %s storage function", "sCAL");
-
- /* Check the arguments. */
- if (width <= 0)
- png_warning(png_ptr, "Invalid sCAL width ignored");
-
- else if (height <= 0)
- png_warning(png_ptr, "Invalid sCAL height ignored");
-
- else
- {
- /* Convert 'width' and 'height' to ASCII. */
- char swidth[PNG_sCAL_MAX_DIGITS+1];
- char sheight[PNG_sCAL_MAX_DIGITS+1];
-
- png_ascii_from_fp(png_ptr, swidth, (sizeof swidth), width,
- PNG_sCAL_PRECISION);
- png_ascii_from_fp(png_ptr, sheight, (sizeof sheight), height,
- PNG_sCAL_PRECISION);
-
- png_set_sCAL_s(png_ptr, info_ptr, unit, swidth, sheight);
- }
-}
-# endif
-
-# ifdef PNG_FIXED_POINT_SUPPORTED
-void PNGAPI
-png_set_sCAL_fixed(png_const_structrp png_ptr, png_inforp info_ptr, int unit,
- png_fixed_point width, png_fixed_point height)
-{
- png_debug1(1, "in %s storage function", "sCAL");
-
- /* Check the arguments. */
- if (width <= 0)
- png_warning(png_ptr, "Invalid sCAL width ignored");
-
- else if (height <= 0)
- png_warning(png_ptr, "Invalid sCAL height ignored");
-
- else
- {
- /* Convert 'width' and 'height' to ASCII. */
- char swidth[PNG_sCAL_MAX_DIGITS+1];
- char sheight[PNG_sCAL_MAX_DIGITS+1];
-
- png_ascii_from_fixed(png_ptr, swidth, (sizeof swidth), width);
- png_ascii_from_fixed(png_ptr, sheight, (sizeof sheight), height);
-
- png_set_sCAL_s(png_ptr, info_ptr, unit, swidth, sheight);
- }
-}
-# endif
-#endif
-
-#ifdef PNG_pHYs_SUPPORTED
-void PNGAPI
-png_set_pHYs(png_const_structrp png_ptr, png_inforp info_ptr,
- png_uint_32 res_x, png_uint_32 res_y, int unit_type)
-{
- png_debug1(1, "in %s storage function", "pHYs");
-
- if (png_ptr == NULL || info_ptr == NULL)
- return;
-
- info_ptr->x_pixels_per_unit = res_x;
- info_ptr->y_pixels_per_unit = res_y;
- info_ptr->phys_unit_type = (png_byte)unit_type;
- info_ptr->valid |= PNG_INFO_pHYs;
-}
-#endif
-
-void PNGAPI
-png_set_PLTE(png_structrp png_ptr, png_inforp info_ptr,
- png_const_colorp palette, int num_palette)
-{
-
- png_debug1(1, "in %s storage function", "PLTE");
-
- if (png_ptr == NULL || info_ptr == NULL)
- return;
-
- if (num_palette < 0 || num_palette > PNG_MAX_PALETTE_LENGTH)
- {
- if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
- png_error(png_ptr, "Invalid palette length");
-
- else
- {
- png_warning(png_ptr, "Invalid palette length");
- return;
- }
- }
-
- if ((num_palette > 0 && palette == NULL) ||
- (num_palette == 0
-# ifdef PNG_MNG_FEATURES_SUPPORTED
- && (png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE) == 0
-# endif
- ))
- {
- png_chunk_report(png_ptr, "Invalid palette", PNG_CHUNK_ERROR);
- return;
- }
-
- /* It may not actually be necessary to set png_ptr->palette here;
- * we do it for backward compatibility with the way the png_handle_tRNS
- * function used to do the allocation.
- *
- * 1.6.0: the above statement appears to be incorrect; something has to set
- * the palette inside png_struct on read.
- */
- png_free_data(png_ptr, info_ptr, PNG_FREE_PLTE, 0);
-
- /* Changed in libpng-1.2.1 to allocate PNG_MAX_PALETTE_LENGTH instead
- * of num_palette entries, in case of an invalid PNG file that has
- * too-large sample values.
- */
- png_ptr->palette = png_voidcast(png_colorp, png_calloc(png_ptr,
- PNG_MAX_PALETTE_LENGTH * (sizeof (png_color))));
-
- if (num_palette > 0)
- memcpy(png_ptr->palette, palette, num_palette * (sizeof (png_color)));
- info_ptr->palette = png_ptr->palette;
- info_ptr->num_palette = png_ptr->num_palette = (png_uint_16)num_palette;
-
- info_ptr->free_me |= PNG_FREE_PLTE;
-
- info_ptr->valid |= PNG_INFO_PLTE;
-}
-
-#ifdef PNG_sBIT_SUPPORTED
-void PNGAPI
-png_set_sBIT(png_const_structrp png_ptr, png_inforp info_ptr,
- png_const_color_8p sig_bit)
-{
- png_debug1(1, "in %s storage function", "sBIT");
-
- if (png_ptr == NULL || info_ptr == NULL || sig_bit == NULL)
- return;
-
- info_ptr->sig_bit = *sig_bit;
- info_ptr->valid |= PNG_INFO_sBIT;
-}
-#endif
-
-#ifdef PNG_sRGB_SUPPORTED
-void PNGAPI
-png_set_sRGB(png_const_structrp png_ptr, png_inforp info_ptr, int srgb_intent)
-{
- png_debug1(1, "in %s storage function", "sRGB");
-
- if (png_ptr == NULL || info_ptr == NULL)
- return;
-
- (void)png_colorspace_set_sRGB(png_ptr, &info_ptr->colorspace, srgb_intent);
- png_colorspace_sync_info(png_ptr, info_ptr);
-}
-
-void PNGAPI
-png_set_sRGB_gAMA_and_cHRM(png_const_structrp png_ptr, png_inforp info_ptr,
- int srgb_intent)
-{
- png_debug1(1, "in %s storage function", "sRGB_gAMA_and_cHRM");
-
- if (png_ptr == NULL || info_ptr == NULL)
- return;
-
- if (png_colorspace_set_sRGB(png_ptr, &info_ptr->colorspace, srgb_intent))
- {
- /* This causes the gAMA and cHRM to be written too */
- info_ptr->colorspace.flags |=
- PNG_COLORSPACE_FROM_gAMA|PNG_COLORSPACE_FROM_cHRM;
- }
-
- png_colorspace_sync_info(png_ptr, info_ptr);
-}
-#endif /* sRGB */
-
-
-#ifdef PNG_iCCP_SUPPORTED
-void PNGAPI
-png_set_iCCP(png_const_structrp png_ptr, png_inforp info_ptr,
- png_const_charp name, int compression_type,
- png_const_bytep profile, png_uint_32 proflen)
-{
- png_charp new_iccp_name;
- png_bytep new_iccp_profile;
- png_size_t length;
-
- png_debug1(1, "in %s storage function", "iCCP");
-
- if (png_ptr == NULL || info_ptr == NULL || name == NULL || profile == NULL)
- return;
-
- if (compression_type != PNG_COMPRESSION_TYPE_BASE)
- png_app_error(png_ptr, "Invalid iCCP compression method");
-
- /* Set the colorspace first because this validates the profile; do not
- * override previously set app cHRM or gAMA here (because likely as not the
- * application knows better than libpng what the correct values are.) Pass
- * the info_ptr color_type field to png_colorspace_set_ICC because in the
- * write case it has not yet been stored in png_ptr.
- */
- {
- int result = png_colorspace_set_ICC(png_ptr, &info_ptr->colorspace, name,
- proflen, profile, info_ptr->color_type);
-
- png_colorspace_sync_info(png_ptr, info_ptr);
-
- /* Don't do any of the copying if the profile was bad, or inconsistent. */
- if (!result)
- return;
-
- /* But do write the gAMA and cHRM chunks from the profile. */
- info_ptr->colorspace.flags |=
- PNG_COLORSPACE_FROM_gAMA|PNG_COLORSPACE_FROM_cHRM;
- }
-
- length = strlen(name)+1;
- new_iccp_name = png_voidcast(png_charp, png_malloc_warn(png_ptr, length));
-
- if (new_iccp_name == NULL)
- {
- png_benign_error(png_ptr, "Insufficient memory to process iCCP chunk");
- return;
- }
-
- memcpy(new_iccp_name, name, length);
- new_iccp_profile = png_voidcast(png_bytep,
- png_malloc_warn(png_ptr, proflen));
-
- if (new_iccp_profile == NULL)
- {
- png_free(png_ptr, new_iccp_name);
- png_benign_error(png_ptr,
- "Insufficient memory to process iCCP profile");
- return;
- }
-
- memcpy(new_iccp_profile, profile, proflen);
-
- png_free_data(png_ptr, info_ptr, PNG_FREE_ICCP, 0);
-
- info_ptr->iccp_proflen = proflen;
- info_ptr->iccp_name = new_iccp_name;
- info_ptr->iccp_profile = new_iccp_profile;
- info_ptr->free_me |= PNG_FREE_ICCP;
- info_ptr->valid |= PNG_INFO_iCCP;
-}
-#endif
-
-#ifdef PNG_TEXT_SUPPORTED
-void PNGAPI
-png_set_text(png_const_structrp png_ptr, png_inforp info_ptr,
- png_const_textp text_ptr, int num_text)
-{
- int ret;
- ret = png_set_text_2(png_ptr, info_ptr, text_ptr, num_text);
-
- if (ret)
- png_error(png_ptr, "Insufficient memory to store text");
-}
-
-int /* PRIVATE */
-png_set_text_2(png_const_structrp png_ptr, png_inforp info_ptr,
- png_const_textp text_ptr, int num_text)
-{
- int i;
-
- png_debug1(1, "in %lx storage function", png_ptr == NULL ? "unexpected" :
- (unsigned long)png_ptr->chunk_name);
-
- if (png_ptr == NULL || info_ptr == NULL || num_text <= 0 || text_ptr == NULL)
- return(0);
-
- /* Make sure we have enough space in the "text" array in info_struct
- * to hold all of the incoming text_ptr objects. This compare can't overflow
- * because max_text >= num_text (anyway, subtract of two positive integers
- * can't overflow in any case.)
- */
- if (num_text > info_ptr->max_text - info_ptr->num_text)
- {
- int old_num_text = info_ptr->num_text;
- int max_text;
- png_textp new_text = NULL;
-
- /* Calculate an appropriate max_text, checking for overflow. */
- max_text = old_num_text;
- if (num_text <= INT_MAX - max_text)
- {
- max_text += num_text;
-
- /* Round up to a multiple of 8 */
- if (max_text < INT_MAX-8)
- max_text = (max_text + 8) & ~0x7;
-
- else
- max_text = INT_MAX;
-
- /* Now allocate a new array and copy the old members in, this does all
- * the overflow checks.
- */
- new_text = png_voidcast(png_textp,png_realloc_array(png_ptr,
- info_ptr->text, old_num_text, max_text-old_num_text,
- sizeof *new_text));
- }
-
- if (new_text == NULL)
- {
- png_chunk_report(png_ptr, "too many text chunks",
- PNG_CHUNK_WRITE_ERROR);
- return 1;
- }
-
- png_free(png_ptr, info_ptr->text);
-
- info_ptr->text = new_text;
- info_ptr->free_me |= PNG_FREE_TEXT;
- info_ptr->max_text = max_text;
- /* num_text is adjusted below as the entries are copied in */
-
- png_debug1(3, "allocated %d entries for info_ptr->text", max_text);
- }
-
- for (i = 0; i < num_text; i++)
- {
- size_t text_length, key_len;
- size_t lang_len, lang_key_len;
- png_textp textp = &(info_ptr->text[info_ptr->num_text]);
-
- if (text_ptr[i].key == NULL)
- continue;
-
- if (text_ptr[i].compression < PNG_TEXT_COMPRESSION_NONE ||
- text_ptr[i].compression >= PNG_TEXT_COMPRESSION_LAST)
- {
- png_chunk_report(png_ptr, "text compression mode is out of range",
- PNG_CHUNK_WRITE_ERROR);
- continue;
- }
-
- key_len = strlen(text_ptr[i].key);
-
- if (text_ptr[i].compression <= 0)
- {
- lang_len = 0;
- lang_key_len = 0;
- }
-
- else
-# ifdef PNG_iTXt_SUPPORTED
- {
- /* Set iTXt data */
-
- if (text_ptr[i].lang != NULL)
- lang_len = strlen(text_ptr[i].lang);
-
- else
- lang_len = 0;
-
- if (text_ptr[i].lang_key != NULL)
- lang_key_len = strlen(text_ptr[i].lang_key);
-
- else
- lang_key_len = 0;
- }
-# else /* PNG_iTXt_SUPPORTED */
- {
- png_chunk_report(png_ptr, "iTXt chunk not supported",
- PNG_CHUNK_WRITE_ERROR);
- continue;
- }
-# endif
-
- if (text_ptr[i].text == NULL || text_ptr[i].text[0] == '\0')
- {
- text_length = 0;
-# ifdef PNG_iTXt_SUPPORTED
- if (text_ptr[i].compression > 0)
- textp->compression = PNG_ITXT_COMPRESSION_NONE;
-
- else
-# endif
- textp->compression = PNG_TEXT_COMPRESSION_NONE;
- }
-
- else
- {
- text_length = strlen(text_ptr[i].text);
- textp->compression = text_ptr[i].compression;
- }
-
- textp->key = png_voidcast(png_charp,png_malloc_base(png_ptr,
- key_len + text_length + lang_len + lang_key_len + 4));
-
- if (textp->key == NULL)
- {
- png_chunk_report(png_ptr, "text chunk: out of memory",
- PNG_CHUNK_WRITE_ERROR);
- return 1;
- }
-
- png_debug2(2, "Allocated %lu bytes at %p in png_set_text",
- (unsigned long)(png_uint_32)
- (key_len + lang_len + lang_key_len + text_length + 4),
- textp->key);
-
- memcpy(textp->key, text_ptr[i].key, key_len);
- *(textp->key + key_len) = '\0';
-
- if (text_ptr[i].compression > 0)
- {
- textp->lang = textp->key + key_len + 1;
- memcpy(textp->lang, text_ptr[i].lang, lang_len);
- *(textp->lang + lang_len) = '\0';
- textp->lang_key = textp->lang + lang_len + 1;
- memcpy(textp->lang_key, text_ptr[i].lang_key, lang_key_len);
- *(textp->lang_key + lang_key_len) = '\0';
- textp->text = textp->lang_key + lang_key_len + 1;
- }
-
- else
- {
- textp->lang=NULL;
- textp->lang_key=NULL;
- textp->text = textp->key + key_len + 1;
- }
-
- if (text_length)
- memcpy(textp->text, text_ptr[i].text, text_length);
-
- *(textp->text + text_length) = '\0';
-
-# ifdef PNG_iTXt_SUPPORTED
- if (textp->compression > 0)
- {
- textp->text_length = 0;
- textp->itxt_length = text_length;
- }
-
- else
-# endif
- {
- textp->text_length = text_length;
- textp->itxt_length = 0;
- }
-
- info_ptr->num_text++;
- png_debug1(3, "transferred text chunk %d", info_ptr->num_text);
- }
-
- return(0);
-}
-#endif
-
-#ifdef PNG_tIME_SUPPORTED
-void PNGAPI
-png_set_tIME(png_const_structrp png_ptr, png_inforp info_ptr,
- png_const_timep mod_time)
-{
- png_debug1(1, "in %s storage function", "tIME");
-
- if (png_ptr == NULL || info_ptr == NULL || mod_time == NULL ||
- (png_ptr->mode & PNG_WROTE_tIME))
- return;
-
- if (mod_time->month == 0 || mod_time->month > 12 ||
- mod_time->day == 0 || mod_time->day > 31 ||
- mod_time->hour > 23 || mod_time->minute > 59 ||
- mod_time->second > 60)
- {
- png_warning(png_ptr, "Ignoring invalid time value");
- return;
- }
-
- info_ptr->mod_time = *mod_time;
- info_ptr->valid |= PNG_INFO_tIME;
-}
-#endif
-
-#ifdef PNG_tRNS_SUPPORTED
-void PNGAPI
-png_set_tRNS(png_structrp png_ptr, png_inforp info_ptr,
- png_const_bytep trans_alpha, int num_trans, png_const_color_16p trans_color)
-{
- png_debug1(1, "in %s storage function", "tRNS");
-
- if (png_ptr == NULL || info_ptr == NULL)
- return;
-
- if (trans_alpha != NULL)
- {
- /* It may not actually be necessary to set png_ptr->trans_alpha here;
- * we do it for backward compatibility with the way the png_handle_tRNS
- * function used to do the allocation.
- *
- * 1.6.0: The above statement is incorrect; png_handle_tRNS effectively
- * relies on png_set_tRNS storing the information in png_struct
- * (otherwise it won't be there for the code in pngrtran.c).
- */
-
- png_free_data(png_ptr, info_ptr, PNG_FREE_TRNS, 0);
-
- /* Changed from num_trans to PNG_MAX_PALETTE_LENGTH in version 1.2.1 */
- png_ptr->trans_alpha = info_ptr->trans_alpha = png_voidcast(png_bytep,
- png_malloc(png_ptr, PNG_MAX_PALETTE_LENGTH));
-
- if (num_trans > 0 && num_trans <= PNG_MAX_PALETTE_LENGTH)
- memcpy(info_ptr->trans_alpha, trans_alpha, (png_size_t)num_trans);
- }
-
- if (trans_color != NULL)
- {
- int sample_max = (1 << info_ptr->bit_depth);
-
- if ((info_ptr->color_type == PNG_COLOR_TYPE_GRAY &&
- trans_color->gray > sample_max) ||
- (info_ptr->color_type == PNG_COLOR_TYPE_RGB &&
- (trans_color->red > sample_max ||
- trans_color->green > sample_max ||
- trans_color->blue > sample_max)))
- png_warning(png_ptr,
- "tRNS chunk has out-of-range samples for bit_depth");
-
- info_ptr->trans_color = *trans_color;
-
- if (num_trans == 0)
- num_trans = 1;
- }
-
- info_ptr->num_trans = (png_uint_16)num_trans;
-
- if (num_trans != 0)
- {
- info_ptr->valid |= PNG_INFO_tRNS;
- info_ptr->free_me |= PNG_FREE_TRNS;
- }
-}
-#endif
-
-#ifdef PNG_sPLT_SUPPORTED
-void PNGAPI
-png_set_sPLT(png_const_structrp png_ptr,
- png_inforp info_ptr, png_const_sPLT_tp entries, int nentries)
-/*
- * entries - array of png_sPLT_t structures
- * to be added to the list of palettes
- * in the info structure.
- *
- * nentries - number of palette structures to be
- * added.
- */
-{
- png_sPLT_tp np;
-
- if (png_ptr == NULL || info_ptr == NULL || nentries <= 0 || entries == NULL)
- return;
-
- /* Use the internal realloc function, which checks for all the possible
- * overflows. Notice that the parameters are (int) and (size_t)
- */
- np = png_voidcast(png_sPLT_tp,png_realloc_array(png_ptr,
- info_ptr->splt_palettes, info_ptr->splt_palettes_num, nentries,
- sizeof *np));
-
- if (np == NULL)
- {
- /* Out of memory or too many chunks */
- png_chunk_report(png_ptr, "too many sPLT chunks", PNG_CHUNK_WRITE_ERROR);
- return;
- }
-
- png_free(png_ptr, info_ptr->splt_palettes);
- info_ptr->splt_palettes = np;
- info_ptr->free_me |= PNG_FREE_SPLT;
-
- np += info_ptr->splt_palettes_num;
-
- do
- {
- png_size_t length;
-
- /* Skip invalid input entries */
- if (entries->name == NULL || entries->entries == NULL)
- {
- /* png_handle_sPLT doesn't do this, so this is an app error */
- png_app_error(png_ptr, "png_set_sPLT: invalid sPLT");
- /* Just skip the invalid entry */
- continue;
- }
-
- np->depth = entries->depth;
-
- /* In the even of out-of-memory just return - there's no point keeping on
- * trying to add sPLT chunks.
- */
- length = strlen(entries->name) + 1;
- np->name = png_voidcast(png_charp, png_malloc_base(png_ptr, length));
-
- if (np->name == NULL)
- break;
-
- memcpy(np->name, entries->name, length);
-
- /* IMPORTANT: we have memory now that won't get freed if something else
- * goes wrong, this code must free it. png_malloc_array produces no
- * warnings, use a png_chunk_report (below) if there is an error.
- */
- np->entries = png_voidcast(png_sPLT_entryp, png_malloc_array(png_ptr,
- entries->nentries, sizeof (png_sPLT_entry)));
-
- if (np->entries == NULL)
- {
- png_free(png_ptr, np->name);
- break;
- }
-
- np->nentries = entries->nentries;
- /* This multiply can't overflow because png_malloc_array has already
- * checked it when doing the allocation.
- */
- memcpy(np->entries, entries->entries,
- entries->nentries * sizeof (png_sPLT_entry));
-
- /* Note that 'continue' skips the advance of the out pointer and out
- * count, so an invalid entry is not added.
- */
- info_ptr->valid |= PNG_INFO_sPLT;
- ++(info_ptr->splt_palettes_num);
- ++np;
- }
- while (++entries, --nentries);
-
- if (nentries > 0)
- png_chunk_report(png_ptr, "sPLT out of memory", PNG_CHUNK_WRITE_ERROR);
-}
-#endif /* PNG_sPLT_SUPPORTED */
-
-#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
-static png_byte
-check_location(png_const_structrp png_ptr, int location)
-{
- location &= (PNG_HAVE_IHDR|PNG_HAVE_PLTE|PNG_AFTER_IDAT);
-
- /* New in 1.6.0; copy the location and check it. This is an API
- * change, previously the app had to use the
- * png_set_unknown_chunk_location API below for each chunk.
- */
- if (location == 0 && !(png_ptr->mode & PNG_IS_READ_STRUCT))
- {
- /* Write struct, so unknown chunks come from the app */
- png_app_warning(png_ptr,
- "png_set_unknown_chunks now expects a valid location");
- /* Use the old behavior */
- location = (png_byte)(png_ptr->mode &
- (PNG_HAVE_IHDR|PNG_HAVE_PLTE|PNG_AFTER_IDAT));
- }
-
- /* This need not be an internal error - if the app calls
- * png_set_unknown_chunks on a read pointer it must get the location right.
- */
- if (location == 0)
- png_error(png_ptr, "invalid location in png_set_unknown_chunks");
-
- /* Now reduce the location to the top-most set bit by removing each least
- * significant bit in turn.
- */
- while (location != (location & -location))
- location &= ~(location & -location);
-
- /* The cast is safe because 'location' is a bit mask and only the low four
- * bits are significant.
- */
- return (png_byte)location;
-}
-
-void PNGAPI
-png_set_unknown_chunks(png_const_structrp png_ptr,
- png_inforp info_ptr, png_const_unknown_chunkp unknowns, int num_unknowns)
-{
- png_unknown_chunkp np;
-
- if (png_ptr == NULL || info_ptr == NULL || num_unknowns <= 0 ||
- unknowns == NULL)
- return;
-
- /* Check for the failure cases where support has been disabled at compile
- * time. This code is hardly ever compiled - it's here because
- * STORE_UNKNOWN_CHUNKS is set by both read and write code (compiling in this
- * code) but may be meaningless if the read or write handling of unknown
- * chunks is not compiled in.
- */
-# if !defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED) && \
- defined(PNG_READ_SUPPORTED)
- if (png_ptr->mode & PNG_IS_READ_STRUCT)
- {
- png_app_error(png_ptr, "no unknown chunk support on read");
- return;
- }
-# endif
-# if !defined(PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED) && \
- defined(PNG_WRITE_SUPPORTED)
- if (!(png_ptr->mode & PNG_IS_READ_STRUCT))
- {
- png_app_error(png_ptr, "no unknown chunk support on write");
- return;
- }
-# endif
-
- /* Prior to 1.6.0 this code used png_malloc_warn; however, this meant that
- * unknown critical chunks could be lost with just a warning resulting in
- * undefined behavior. Now png_chunk_report is used to provide behavior
- * appropriate to read or write.
- */
- np = png_voidcast(png_unknown_chunkp, png_realloc_array(png_ptr,
- info_ptr->unknown_chunks, info_ptr->unknown_chunks_num, num_unknowns,
- sizeof *np));
-
- if (np == NULL)
- {
- png_chunk_report(png_ptr, "too many unknown chunks",
- PNG_CHUNK_WRITE_ERROR);
- return;
- }
-
- png_free(png_ptr, info_ptr->unknown_chunks);
- info_ptr->unknown_chunks = np; /* safe because it is initialized */
- info_ptr->free_me |= PNG_FREE_UNKN;
-
- np += info_ptr->unknown_chunks_num;
-
- /* Increment unknown_chunks_num each time round the loop to protect the
- * just-allocated chunk data.
- */
- for (; num_unknowns > 0; --num_unknowns, ++unknowns)
- {
- memcpy(np->name, unknowns->name, (sizeof np->name));
- np->name[(sizeof np->name)-1] = '\0';
- np->location = check_location(png_ptr, unknowns->location);
-
- if (unknowns->size == 0)
- {
- np->data = NULL;
- np->size = 0;
- }
-
- else
- {
- np->data = png_voidcast(png_bytep,
- png_malloc_base(png_ptr, unknowns->size));
-
- if (np->data == NULL)
- {
- png_chunk_report(png_ptr, "unknown chunk: out of memory",
- PNG_CHUNK_WRITE_ERROR);
- /* But just skip storing the unknown chunk */
- continue;
- }
-
- memcpy(np->data, unknowns->data, unknowns->size);
- np->size = unknowns->size;
- }
-
- /* These increments are skipped on out-of-memory for the data - the
- * unknown chunk entry gets overwritten if the png_chunk_report returns.
- * This is correct in the read case (the chunk is just dropped.)
- */
- ++np;
- ++(info_ptr->unknown_chunks_num);
- }
-}
-
-void PNGAPI
-png_set_unknown_chunk_location(png_const_structrp png_ptr, png_inforp info_ptr,
- int chunk, int location)
-{
- /* This API is pretty pointless in 1.6.0 because the location can be set
- * before the call to png_set_unknown_chunks.
- *
- * TODO: add a png_app_warning in 1.7
- */
- if (png_ptr != NULL && info_ptr != NULL && chunk >= 0 &&
- chunk < info_ptr->unknown_chunks_num)
- {
- if ((location & (PNG_HAVE_IHDR|PNG_HAVE_PLTE|PNG_AFTER_IDAT)) == 0)
- {
- png_app_error(png_ptr, "invalid unknown chunk location");
- /* Fake out the pre 1.6.0 behavior: */
- if ((location & PNG_HAVE_IDAT)) /* undocumented! */
- location = PNG_AFTER_IDAT;
-
- else
- location = PNG_HAVE_IHDR; /* also undocumented */
- }
-
- info_ptr->unknown_chunks[chunk].location =
- check_location(png_ptr, location);
- }
-}
-#endif
-
-
-#ifdef PNG_MNG_FEATURES_SUPPORTED
-png_uint_32 PNGAPI
-png_permit_mng_features (png_structrp png_ptr, png_uint_32 mng_features)
-{
- png_debug(1, "in png_permit_mng_features");
-
- if (png_ptr == NULL)
- return 0;
-
- png_ptr->mng_features_permitted = mng_features & PNG_ALL_MNG_FEATURES;
-
- return png_ptr->mng_features_permitted;
-}
-#endif
-
-#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
-static unsigned int
-add_one_chunk(png_bytep list, unsigned int count, png_const_bytep add, int keep)
-{
- unsigned int i;
-
- /* Utility function: update the 'keep' state of a chunk if it is already in
- * the list, otherwise add it to the list.
- */
- for (i=0; i<count; ++i, list += 5) if (memcmp(list, add, 4) == 0)
- {
- list[4] = (png_byte)keep;
- return count;
- }
-
- if (keep != PNG_HANDLE_CHUNK_AS_DEFAULT)
- {
- ++count;
- memcpy(list, add, 4);
- list[4] = (png_byte)keep;
- }
-
- return count;
-}
-
-void PNGAPI
-png_set_keep_unknown_chunks(png_structrp png_ptr, int keep,
- png_const_bytep chunk_list, int num_chunks_in)
-{
- png_bytep new_list;
- unsigned int num_chunks, old_num_chunks;
-
- if (png_ptr == NULL)
- return;
-
- if (keep < 0 || keep >= PNG_HANDLE_CHUNK_LAST)
- {
- png_app_error(png_ptr, "png_set_keep_unknown_chunks: invalid keep");
- return;
- }
-
- if (num_chunks_in <= 0)
- {
- png_ptr->unknown_default = keep;
-
- /* '0' means just set the flags, so stop here */
- if (num_chunks_in == 0)
- return;
- }
-
- if (num_chunks_in < 0)
- {
- /* Ignore all unknown chunks and all chunks recognized by
- * libpng except for IHDR, PLTE, tRNS, IDAT, and IEND
- */
- static PNG_CONST png_byte chunks_to_ignore[] = {
- 98, 75, 71, 68, '\0', /* bKGD */
- 99, 72, 82, 77, '\0', /* cHRM */
- 103, 65, 77, 65, '\0', /* gAMA */
- 104, 73, 83, 84, '\0', /* hIST */
- 105, 67, 67, 80, '\0', /* iCCP */
- 105, 84, 88, 116, '\0', /* iTXt */
- 111, 70, 70, 115, '\0', /* oFFs */
- 112, 67, 65, 76, '\0', /* pCAL */
- 112, 72, 89, 115, '\0', /* pHYs */
- 115, 66, 73, 84, '\0', /* sBIT */
- 115, 67, 65, 76, '\0', /* sCAL */
- 115, 80, 76, 84, '\0', /* sPLT */
- 115, 84, 69, 82, '\0', /* sTER */
- 115, 82, 71, 66, '\0', /* sRGB */
- 116, 69, 88, 116, '\0', /* tEXt */
- 116, 73, 77, 69, '\0', /* tIME */
- 122, 84, 88, 116, '\0' /* zTXt */
- };
-
- chunk_list = chunks_to_ignore;
- num_chunks = (sizeof chunks_to_ignore)/5;
- }
-
- else /* num_chunks_in > 0 */
- {
- if (chunk_list == NULL)
- {
- /* Prior to 1.6.0 this was silently ignored, now it is an app_error
- * which can be switched off.
- */
- png_app_error(png_ptr, "png_set_keep_unknown_chunks: no chunk list");
- return;
- }
-
- num_chunks = num_chunks_in;
- }
-
- old_num_chunks = png_ptr->num_chunk_list;
- if (png_ptr->chunk_list == NULL)
- old_num_chunks = 0;
-
- /* Since num_chunks is always restricted to UINT_MAX/5 this can't overflow.
- */
- if (num_chunks + old_num_chunks > UINT_MAX/5)
- {
- png_app_error(png_ptr, "png_set_keep_unknown_chunks: too many chunks");
- return;
- }
-
- /* If these chunks are being reset to the default then no more memory is
- * required because add_one_chunk above doesn't extend the list if the 'keep'
- * parameter is the default.
- */
- if (keep)
- {
- new_list = png_voidcast(png_bytep, png_malloc(png_ptr,
- 5 * (num_chunks + old_num_chunks)));
-
- if (old_num_chunks > 0)
- memcpy(new_list, png_ptr->chunk_list, 5*old_num_chunks);
- }
-
- else if (old_num_chunks > 0)
- new_list = png_ptr->chunk_list;
-
- else
- new_list = NULL;
-
- /* Add the new chunks together with each one's handling code. If the chunk
- * already exists the code is updated, otherwise the chunk is added to the
- * end. (In libpng 1.6.0 order no longer matters because this code enforces
- * the earlier convention that the last setting is the one that is used.)
- */
- if (new_list != NULL)
- {
- png_const_bytep inlist;
- png_bytep outlist;
- unsigned int i;
-
- for (i=0; i<num_chunks; ++i)
- old_num_chunks = add_one_chunk(new_list, old_num_chunks,
- chunk_list+5*i, keep);
-
- /* Now remove any spurious 'default' entries. */
- num_chunks = 0;
- for (i=0, inlist=outlist=new_list; i<old_num_chunks; ++i, inlist += 5)
- if (inlist[4])
- {
- if (outlist != inlist)
- memcpy(outlist, inlist, 5);
- outlist += 5;
- ++num_chunks;
- }
-
- /* This means the application has removed all the specialized handling. */
- if (num_chunks == 0)
- {
- if (png_ptr->chunk_list != new_list)
- png_free(png_ptr, new_list);
-
- new_list = NULL;
- }
- }
-
- else
- num_chunks = 0;
-
- png_ptr->num_chunk_list = num_chunks;
-
- if (png_ptr->chunk_list != new_list)
- {
- if (png_ptr->chunk_list != NULL)
- png_free(png_ptr, png_ptr->chunk_list);
-
- png_ptr->chunk_list = new_list;
- }
-}
-#endif
-
-#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
-void PNGAPI
-png_set_read_user_chunk_fn(png_structrp png_ptr, png_voidp user_chunk_ptr,
- png_user_chunk_ptr read_user_chunk_fn)
-{
- png_debug(1, "in png_set_read_user_chunk_fn");
-
- if (png_ptr == NULL)
- return;
-
- png_ptr->read_user_chunk_fn = read_user_chunk_fn;
- png_ptr->user_chunk_ptr = user_chunk_ptr;
-}
-#endif
-
-#ifdef PNG_INFO_IMAGE_SUPPORTED
-void PNGAPI
-png_set_rows(png_const_structrp png_ptr, png_inforp info_ptr,
- png_bytepp row_pointers)
-{
- png_debug1(1, "in %s storage function", "rows");
-
- if (png_ptr == NULL || info_ptr == NULL)
- return;
-
- if (info_ptr->row_pointers && (info_ptr->row_pointers != row_pointers))
- png_free_data(png_ptr, info_ptr, PNG_FREE_ROWS, 0);
-
- info_ptr->row_pointers = row_pointers;
-
- if (row_pointers)
- info_ptr->valid |= PNG_INFO_IDAT;
-}
-#endif
-
-void PNGAPI
-png_set_compression_buffer_size(png_structrp png_ptr, png_size_t size)
-{
- if (png_ptr == NULL)
- return;
-
- if (size == 0 || size > PNG_UINT_31_MAX)
- png_error(png_ptr, "invalid compression buffer size");
-
-# ifdef PNG_SEQUENTIAL_READ_SUPPORTED
- if (png_ptr->mode & PNG_IS_READ_STRUCT)
- {
- png_ptr->IDAT_read_size = (png_uint_32)size; /* checked above */
- return;
- }
-# endif
-
-# ifdef PNG_WRITE_SUPPORTED
- if (!(png_ptr->mode & PNG_IS_READ_STRUCT))
- {
- if (png_ptr->zowner != 0)
- {
- png_warning(png_ptr,
- "Compression buffer size cannot be changed because it is in use");
- return;
- }
-
- if (size > ZLIB_IO_MAX)
- {
- png_warning(png_ptr,
- "Compression buffer size limited to system maximum");
- size = ZLIB_IO_MAX; /* must fit */
- }
-
- else if (size < 6)
- {
- /* Deflate will potentially go into an infinite loop on a SYNC_FLUSH
- * if this is permitted.
- */
- png_warning(png_ptr,
- "Compression buffer size cannot be reduced below 6");
- return;
- }
-
- if (png_ptr->zbuffer_size != size)
- {
- png_free_buffer_list(png_ptr, &png_ptr->zbuffer_list);
- png_ptr->zbuffer_size = (uInt)size;
- }
- }
-# endif
-}
-
-void PNGAPI
-png_set_invalid(png_const_structrp png_ptr, png_inforp info_ptr, int mask)
-{
- if (png_ptr && info_ptr)
- info_ptr->valid &= ~mask;
-}
-
-
-#ifdef PNG_SET_USER_LIMITS_SUPPORTED
-/* This function was added to libpng 1.2.6 */
-void PNGAPI
-png_set_user_limits (png_structrp png_ptr, png_uint_32 user_width_max,
- png_uint_32 user_height_max)
-{
- /* Images with dimensions larger than these limits will be
- * rejected by png_set_IHDR(). To accept any PNG datastream
- * regardless of dimensions, set both limits to 0x7ffffffL.
- */
- if (png_ptr == NULL)
- return;
-
- png_ptr->user_width_max = user_width_max;
- png_ptr->user_height_max = user_height_max;
-}
-
-/* This function was added to libpng 1.4.0 */
-void PNGAPI
-png_set_chunk_cache_max (png_structrp png_ptr, png_uint_32 user_chunk_cache_max)
-{
- if (png_ptr)
- png_ptr->user_chunk_cache_max = user_chunk_cache_max;
-}
-
-/* This function was added to libpng 1.4.1 */
-void PNGAPI
-png_set_chunk_malloc_max (png_structrp png_ptr,
- png_alloc_size_t user_chunk_malloc_max)
-{
- if (png_ptr)
- png_ptr->user_chunk_malloc_max = user_chunk_malloc_max;
-}
-#endif /* ?PNG_SET_USER_LIMITS_SUPPORTED */
-
-
-#ifdef PNG_BENIGN_ERRORS_SUPPORTED
-void PNGAPI
-png_set_benign_errors(png_structrp png_ptr, int allowed)
-{
- png_debug(1, "in png_set_benign_errors");
-
- /* If allowed is 1, png_benign_error() is treated as a warning.
- *
- * If allowed is 0, png_benign_error() is treated as an error (which
- * is the default behavior if png_set_benign_errors() is not called).
- */
-
- if (allowed)
- png_ptr->flags |= PNG_FLAG_BENIGN_ERRORS_WARN |
- PNG_FLAG_APP_WARNINGS_WARN | PNG_FLAG_APP_ERRORS_WARN;
-
- else
- png_ptr->flags &= ~(PNG_FLAG_BENIGN_ERRORS_WARN |
- PNG_FLAG_APP_WARNINGS_WARN | PNG_FLAG_APP_ERRORS_WARN);
-}
-#endif /* PNG_BENIGN_ERRORS_SUPPORTED */
-
-#ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED
- /* Whether to report invalid palette index; added at libng-1.5.10.
- * It is possible for an indexed (color-type==3) PNG file to contain
- * pixels with invalid (out-of-range) indexes if the PLTE chunk has
- * fewer entries than the image's bit-depth would allow. We recover
- * from this gracefully by filling any incomplete palette with zeroes
- * (opaque black). By default, when this occurs libpng will issue
- * a benign error. This API can be used to override that behavior.
- */
-void PNGAPI
-png_set_check_for_invalid_index(png_structrp png_ptr, int allowed)
-{
- png_debug(1, "in png_set_check_for_invalid_index");
-
- if (allowed > 0)
- png_ptr->num_palette_max = 0;
-
- else
- png_ptr->num_palette_max = -1;
-}
-#endif
-#endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */
+
+/* pngset.c - storage of image information into info struct
+ *
+ * Last changed in libpng 1.6.19 [November 12, 2015]
+ * Copyright (c) 1998-2015 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ * The functions here are used during reads to store data from the file
+ * into the info struct, and during writes to store application data
+ * into the info struct for writing into the file. This abstracts the
+ * info struct and allows us to change the structure in the future.
+ */
+
+#include "pngpriv.h"
+
+#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
+
+#ifdef PNG_bKGD_SUPPORTED
+void PNGAPI
+png_set_bKGD(png_const_structrp png_ptr, png_inforp info_ptr,
+ png_const_color_16p background)
+{
+ png_debug1(1, "in %s storage function", "bKGD");
+
+ if (png_ptr == NULL || info_ptr == NULL || background == NULL)
+ return;
+
+ info_ptr->background = *background;
+ info_ptr->valid |= PNG_INFO_bKGD;
+}
+#endif
+
+#ifdef PNG_cHRM_SUPPORTED
+void PNGFAPI
+png_set_cHRM_fixed(png_const_structrp png_ptr, png_inforp info_ptr,
+ png_fixed_point white_x, png_fixed_point white_y, png_fixed_point red_x,
+ png_fixed_point red_y, png_fixed_point green_x, png_fixed_point green_y,
+ png_fixed_point blue_x, png_fixed_point blue_y)
+{
+ png_xy xy;
+
+ png_debug1(1, "in %s storage function", "cHRM fixed");
+
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+ xy.redx = red_x;
+ xy.redy = red_y;
+ xy.greenx = green_x;
+ xy.greeny = green_y;
+ xy.bluex = blue_x;
+ xy.bluey = blue_y;
+ xy.whitex = white_x;
+ xy.whitey = white_y;
+
+ if (png_colorspace_set_chromaticities(png_ptr, &info_ptr->colorspace, &xy,
+ 2/* override with app values*/) != 0)
+ info_ptr->colorspace.flags |= PNG_COLORSPACE_FROM_cHRM;
+
+ png_colorspace_sync_info(png_ptr, info_ptr);
+}
+
+void PNGFAPI
+png_set_cHRM_XYZ_fixed(png_const_structrp png_ptr, png_inforp info_ptr,
+ png_fixed_point int_red_X, png_fixed_point int_red_Y,
+ png_fixed_point int_red_Z, png_fixed_point int_green_X,
+ png_fixed_point int_green_Y, png_fixed_point int_green_Z,
+ png_fixed_point int_blue_X, png_fixed_point int_blue_Y,
+ png_fixed_point int_blue_Z)
+{
+ png_XYZ XYZ;
+
+ png_debug1(1, "in %s storage function", "cHRM XYZ fixed");
+
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+ XYZ.red_X = int_red_X;
+ XYZ.red_Y = int_red_Y;
+ XYZ.red_Z = int_red_Z;
+ XYZ.green_X = int_green_X;
+ XYZ.green_Y = int_green_Y;
+ XYZ.green_Z = int_green_Z;
+ XYZ.blue_X = int_blue_X;
+ XYZ.blue_Y = int_blue_Y;
+ XYZ.blue_Z = int_blue_Z;
+
+ if (png_colorspace_set_endpoints(png_ptr, &info_ptr->colorspace,
+ &XYZ, 2) != 0)
+ info_ptr->colorspace.flags |= PNG_COLORSPACE_FROM_cHRM;
+
+ png_colorspace_sync_info(png_ptr, info_ptr);
+}
+
+# ifdef PNG_FLOATING_POINT_SUPPORTED
+void PNGAPI
+png_set_cHRM(png_const_structrp png_ptr, png_inforp info_ptr,
+ double white_x, double white_y, double red_x, double red_y,
+ double green_x, double green_y, double blue_x, double blue_y)
+{
+ png_set_cHRM_fixed(png_ptr, info_ptr,
+ png_fixed(png_ptr, white_x, "cHRM White X"),
+ png_fixed(png_ptr, white_y, "cHRM White Y"),
+ png_fixed(png_ptr, red_x, "cHRM Red X"),
+ png_fixed(png_ptr, red_y, "cHRM Red Y"),
+ png_fixed(png_ptr, green_x, "cHRM Green X"),
+ png_fixed(png_ptr, green_y, "cHRM Green Y"),
+ png_fixed(png_ptr, blue_x, "cHRM Blue X"),
+ png_fixed(png_ptr, blue_y, "cHRM Blue Y"));
+}
+
+void PNGAPI
+png_set_cHRM_XYZ(png_const_structrp png_ptr, png_inforp info_ptr, double red_X,
+ double red_Y, double red_Z, double green_X, double green_Y, double green_Z,
+ double blue_X, double blue_Y, double blue_Z)
+{
+ png_set_cHRM_XYZ_fixed(png_ptr, info_ptr,
+ png_fixed(png_ptr, red_X, "cHRM Red X"),
+ png_fixed(png_ptr, red_Y, "cHRM Red Y"),
+ png_fixed(png_ptr, red_Z, "cHRM Red Z"),
+ png_fixed(png_ptr, green_X, "cHRM Green X"),
+ png_fixed(png_ptr, green_Y, "cHRM Green Y"),
+ png_fixed(png_ptr, green_Z, "cHRM Green Z"),
+ png_fixed(png_ptr, blue_X, "cHRM Blue X"),
+ png_fixed(png_ptr, blue_Y, "cHRM Blue Y"),
+ png_fixed(png_ptr, blue_Z, "cHRM Blue Z"));
+}
+# endif /* FLOATING_POINT */
+
+#endif /* cHRM */
+
+#ifdef PNG_gAMA_SUPPORTED
+void PNGFAPI
+png_set_gAMA_fixed(png_const_structrp png_ptr, png_inforp info_ptr,
+ png_fixed_point file_gamma)
+{
+ png_debug1(1, "in %s storage function", "gAMA");
+
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+ png_colorspace_set_gamma(png_ptr, &info_ptr->colorspace, file_gamma);
+ png_colorspace_sync_info(png_ptr, info_ptr);
+}
+
+# ifdef PNG_FLOATING_POINT_SUPPORTED
+void PNGAPI
+png_set_gAMA(png_const_structrp png_ptr, png_inforp info_ptr, double file_gamma)
+{
+ png_set_gAMA_fixed(png_ptr, info_ptr, png_fixed(png_ptr, file_gamma,
+ "png_set_gAMA"));
+}
+# endif
+#endif
+
+#ifdef PNG_hIST_SUPPORTED
+void PNGAPI
+png_set_hIST(png_const_structrp png_ptr, png_inforp info_ptr,
+ png_const_uint_16p hist)
+{
+ int i;
+
+ png_debug1(1, "in %s storage function", "hIST");
+
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+ if (info_ptr->num_palette == 0 || info_ptr->num_palette
+ > PNG_MAX_PALETTE_LENGTH)
+ {
+ png_warning(png_ptr,
+ "Invalid palette size, hIST allocation skipped");
+
+ return;
+ }
+
+ png_free_data(png_ptr, info_ptr, PNG_FREE_HIST, 0);
+
+ /* Changed from info->num_palette to PNG_MAX_PALETTE_LENGTH in
+ * version 1.2.1
+ */
+ info_ptr->hist = png_voidcast(png_uint_16p, png_malloc_warn(png_ptr,
+ PNG_MAX_PALETTE_LENGTH * (sizeof (png_uint_16))));
+
+ if (info_ptr->hist == NULL)
+ {
+ png_warning(png_ptr, "Insufficient memory for hIST chunk data");
+
+ return;
+ }
+
+ info_ptr->free_me |= PNG_FREE_HIST;
+
+ for (i = 0; i < info_ptr->num_palette; i++)
+ info_ptr->hist[i] = hist[i];
+
+ info_ptr->valid |= PNG_INFO_hIST;
+}
+#endif
+
+void PNGAPI
+png_set_IHDR(png_const_structrp png_ptr, png_inforp info_ptr,
+ png_uint_32 width, png_uint_32 height, int bit_depth,
+ int color_type, int interlace_type, int compression_type,
+ int filter_type)
+{
+ png_debug1(1, "in %s storage function", "IHDR");
+
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+ info_ptr->width = width;
+ info_ptr->height = height;
+ info_ptr->bit_depth = (png_byte)bit_depth;
+ info_ptr->color_type = (png_byte)color_type;
+ info_ptr->compression_type = (png_byte)compression_type;
+ info_ptr->filter_type = (png_byte)filter_type;
+ info_ptr->interlace_type = (png_byte)interlace_type;
+
+ png_check_IHDR (png_ptr, info_ptr->width, info_ptr->height,
+ info_ptr->bit_depth, info_ptr->color_type, info_ptr->interlace_type,
+ info_ptr->compression_type, info_ptr->filter_type);
+
+ if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+ info_ptr->channels = 1;
+
+ else if ((info_ptr->color_type & PNG_COLOR_MASK_COLOR) != 0)
+ info_ptr->channels = 3;
+
+ else
+ info_ptr->channels = 1;
+
+ if ((info_ptr->color_type & PNG_COLOR_MASK_ALPHA) != 0)
+ info_ptr->channels++;
+
+ info_ptr->pixel_depth = (png_byte)(info_ptr->channels * info_ptr->bit_depth);
+
+ info_ptr->rowbytes = PNG_ROWBYTES(info_ptr->pixel_depth, width);
+}
+
+#ifdef PNG_oFFs_SUPPORTED
+void PNGAPI
+png_set_oFFs(png_const_structrp png_ptr, png_inforp info_ptr,
+ png_int_32 offset_x, png_int_32 offset_y, int unit_type)
+{
+ png_debug1(1, "in %s storage function", "oFFs");
+
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+ info_ptr->x_offset = offset_x;
+ info_ptr->y_offset = offset_y;
+ info_ptr->offset_unit_type = (png_byte)unit_type;
+ info_ptr->valid |= PNG_INFO_oFFs;
+}
+#endif
+
+#ifdef PNG_pCAL_SUPPORTED
+void PNGAPI
+png_set_pCAL(png_const_structrp png_ptr, png_inforp info_ptr,
+ png_const_charp purpose, png_int_32 X0, png_int_32 X1, int type,
+ int nparams, png_const_charp units, png_charpp params)
+{
+ png_size_t length;
+ int i;
+
+ png_debug1(1, "in %s storage function", "pCAL");
+
+ if (png_ptr == NULL || info_ptr == NULL || purpose == NULL || units == NULL
+ || (nparams > 0 && params == NULL))
+ return;
+
+ length = strlen(purpose) + 1;
+ png_debug1(3, "allocating purpose for info (%lu bytes)",
+ (unsigned long)length);
+
+ /* TODO: validate format of calibration name and unit name */
+
+ /* Check that the type matches the specification. */
+ if (type < 0 || type > 3)
+ png_error(png_ptr, "Invalid pCAL equation type");
+
+ if (nparams < 0 || nparams > 255)
+ png_error(png_ptr, "Invalid pCAL parameter count");
+
+ /* Validate params[nparams] */
+ for (i=0; i<nparams; ++i)
+ {
+ if (params[i] == NULL ||
+ !png_check_fp_string(params[i], strlen(params[i])))
+ png_error(png_ptr, "Invalid format for pCAL parameter");
+ }
+
+ info_ptr->pcal_purpose = png_voidcast(png_charp,
+ png_malloc_warn(png_ptr, length));
+
+ if (info_ptr->pcal_purpose == NULL)
+ {
+ png_warning(png_ptr, "Insufficient memory for pCAL purpose");
+
+ return;
+ }
+
+ memcpy(info_ptr->pcal_purpose, purpose, length);
+
+ png_debug(3, "storing X0, X1, type, and nparams in info");
+ info_ptr->pcal_X0 = X0;
+ info_ptr->pcal_X1 = X1;
+ info_ptr->pcal_type = (png_byte)type;
+ info_ptr->pcal_nparams = (png_byte)nparams;
+
+ length = strlen(units) + 1;
+ png_debug1(3, "allocating units for info (%lu bytes)",
+ (unsigned long)length);
+
+ info_ptr->pcal_units = png_voidcast(png_charp,
+ png_malloc_warn(png_ptr, length));
+
+ if (info_ptr->pcal_units == NULL)
+ {
+ png_warning(png_ptr, "Insufficient memory for pCAL units");
+
+ return;
+ }
+
+ memcpy(info_ptr->pcal_units, units, length);
+
+ info_ptr->pcal_params = png_voidcast(png_charpp, png_malloc_warn(png_ptr,
+ (png_size_t)((nparams + 1) * (sizeof (png_charp)))));
+
+ if (info_ptr->pcal_params == NULL)
+ {
+ png_warning(png_ptr, "Insufficient memory for pCAL params");
+
+ return;
+ }
+
+ memset(info_ptr->pcal_params, 0, (nparams + 1) * (sizeof (png_charp)));
+
+ for (i = 0; i < nparams; i++)
+ {
+ length = strlen(params[i]) + 1;
+ png_debug2(3, "allocating parameter %d for info (%lu bytes)", i,
+ (unsigned long)length);
+
+ info_ptr->pcal_params[i] = (png_charp)png_malloc_warn(png_ptr, length);
+
+ if (info_ptr->pcal_params[i] == NULL)
+ {
+ png_warning(png_ptr, "Insufficient memory for pCAL parameter");
+
+ return;
+ }
+
+ memcpy(info_ptr->pcal_params[i], params[i], length);
+ }
+
+ info_ptr->valid |= PNG_INFO_pCAL;
+ info_ptr->free_me |= PNG_FREE_PCAL;
+}
+#endif
+
+#ifdef PNG_sCAL_SUPPORTED
+void PNGAPI
+png_set_sCAL_s(png_const_structrp png_ptr, png_inforp info_ptr,
+ int unit, png_const_charp swidth, png_const_charp sheight)
+{
+ png_size_t lengthw = 0, lengthh = 0;
+
+ png_debug1(1, "in %s storage function", "sCAL");
+
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+ /* Double check the unit (should never get here with an invalid
+ * unit unless this is an API call.)
+ */
+ if (unit != 1 && unit != 2)
+ png_error(png_ptr, "Invalid sCAL unit");
+
+ if (swidth == NULL || (lengthw = strlen(swidth)) == 0 ||
+ swidth[0] == 45 /* '-' */ || !png_check_fp_string(swidth, lengthw))
+ png_error(png_ptr, "Invalid sCAL width");
+
+ if (sheight == NULL || (lengthh = strlen(sheight)) == 0 ||
+ sheight[0] == 45 /* '-' */ || !png_check_fp_string(sheight, lengthh))
+ png_error(png_ptr, "Invalid sCAL height");
+
+ info_ptr->scal_unit = (png_byte)unit;
+
+ ++lengthw;
+
+ png_debug1(3, "allocating unit for info (%u bytes)", (unsigned int)lengthw);
+
+ info_ptr->scal_s_width = png_voidcast(png_charp,
+ png_malloc_warn(png_ptr, lengthw));
+
+ if (info_ptr->scal_s_width == NULL)
+ {
+ png_warning(png_ptr, "Memory allocation failed while processing sCAL");
+
+ return;
+ }
+
+ memcpy(info_ptr->scal_s_width, swidth, lengthw);
+
+ ++lengthh;
+
+ png_debug1(3, "allocating unit for info (%u bytes)", (unsigned int)lengthh);
+
+ info_ptr->scal_s_height = png_voidcast(png_charp,
+ png_malloc_warn(png_ptr, lengthh));
+
+ if (info_ptr->scal_s_height == NULL)
+ {
+ png_free (png_ptr, info_ptr->scal_s_width);
+ info_ptr->scal_s_width = NULL;
+
+ png_warning(png_ptr, "Memory allocation failed while processing sCAL");
+
+ return;
+ }
+
+ memcpy(info_ptr->scal_s_height, sheight, lengthh);
+
+ info_ptr->valid |= PNG_INFO_sCAL;
+ info_ptr->free_me |= PNG_FREE_SCAL;
+}
+
+# ifdef PNG_FLOATING_POINT_SUPPORTED
+void PNGAPI
+png_set_sCAL(png_const_structrp png_ptr, png_inforp info_ptr, int unit,
+ double width, double height)
+{
+ png_debug1(1, "in %s storage function", "sCAL");
+
+ /* Check the arguments. */
+ if (width <= 0)
+ png_warning(png_ptr, "Invalid sCAL width ignored");
+
+ else if (height <= 0)
+ png_warning(png_ptr, "Invalid sCAL height ignored");
+
+ else
+ {
+ /* Convert 'width' and 'height' to ASCII. */
+ char swidth[PNG_sCAL_MAX_DIGITS+1];
+ char sheight[PNG_sCAL_MAX_DIGITS+1];
+
+ png_ascii_from_fp(png_ptr, swidth, (sizeof swidth), width,
+ PNG_sCAL_PRECISION);
+ png_ascii_from_fp(png_ptr, sheight, (sizeof sheight), height,
+ PNG_sCAL_PRECISION);
+
+ png_set_sCAL_s(png_ptr, info_ptr, unit, swidth, sheight);
+ }
+}
+# endif
+
+# ifdef PNG_FIXED_POINT_SUPPORTED
+void PNGAPI
+png_set_sCAL_fixed(png_const_structrp png_ptr, png_inforp info_ptr, int unit,
+ png_fixed_point width, png_fixed_point height)
+{
+ png_debug1(1, "in %s storage function", "sCAL");
+
+ /* Check the arguments. */
+ if (width <= 0)
+ png_warning(png_ptr, "Invalid sCAL width ignored");
+
+ else if (height <= 0)
+ png_warning(png_ptr, "Invalid sCAL height ignored");
+
+ else
+ {
+ /* Convert 'width' and 'height' to ASCII. */
+ char swidth[PNG_sCAL_MAX_DIGITS+1];
+ char sheight[PNG_sCAL_MAX_DIGITS+1];
+
+ png_ascii_from_fixed(png_ptr, swidth, (sizeof swidth), width);
+ png_ascii_from_fixed(png_ptr, sheight, (sizeof sheight), height);
+
+ png_set_sCAL_s(png_ptr, info_ptr, unit, swidth, sheight);
+ }
+}
+# endif
+#endif
+
+#ifdef PNG_pHYs_SUPPORTED
+void PNGAPI
+png_set_pHYs(png_const_structrp png_ptr, png_inforp info_ptr,
+ png_uint_32 res_x, png_uint_32 res_y, int unit_type)
+{
+ png_debug1(1, "in %s storage function", "pHYs");
+
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+ info_ptr->x_pixels_per_unit = res_x;
+ info_ptr->y_pixels_per_unit = res_y;
+ info_ptr->phys_unit_type = (png_byte)unit_type;
+ info_ptr->valid |= PNG_INFO_pHYs;
+}
+#endif
+
+void PNGAPI
+png_set_PLTE(png_structrp png_ptr, png_inforp info_ptr,
+ png_const_colorp palette, int num_palette)
+{
+
+ png_uint_32 max_palette_length;
+
+ png_debug1(1, "in %s storage function", "PLTE");
+
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+ max_palette_length = (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) ?
+ (1 << info_ptr->bit_depth) : PNG_MAX_PALETTE_LENGTH;
+
+ if (num_palette < 0 || num_palette > (int) max_palette_length)
+ {
+ if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+ png_error(png_ptr, "Invalid palette length");
+
+ else
+ {
+ png_warning(png_ptr, "Invalid palette length");
+
+ return;
+ }
+ }
+
+ if ((num_palette > 0 && palette == NULL) ||
+ (num_palette == 0
+# ifdef PNG_MNG_FEATURES_SUPPORTED
+ && (png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE) == 0
+# endif
+ ))
+ {
+ png_error(png_ptr, "Invalid palette");
+ }
+
+ /* It may not actually be necessary to set png_ptr->palette here;
+ * we do it for backward compatibility with the way the png_handle_tRNS
+ * function used to do the allocation.
+ *
+ * 1.6.0: the above statement appears to be incorrect; something has to set
+ * the palette inside png_struct on read.
+ */
+ png_free_data(png_ptr, info_ptr, PNG_FREE_PLTE, 0);
+
+ /* Changed in libpng-1.2.1 to allocate PNG_MAX_PALETTE_LENGTH instead
+ * of num_palette entries, in case of an invalid PNG file or incorrect
+ * call to png_set_PLTE() with too-large sample values.
+ */
+ png_ptr->palette = png_voidcast(png_colorp, png_calloc(png_ptr,
+ PNG_MAX_PALETTE_LENGTH * (sizeof (png_color))));
+
+ if (num_palette > 0)
+ memcpy(png_ptr->palette, palette, num_palette * (sizeof (png_color)));
+ info_ptr->palette = png_ptr->palette;
+ info_ptr->num_palette = png_ptr->num_palette = (png_uint_16)num_palette;
+
+ info_ptr->free_me |= PNG_FREE_PLTE;
+
+ info_ptr->valid |= PNG_INFO_PLTE;
+}
+
+#ifdef PNG_sBIT_SUPPORTED
+void PNGAPI
+png_set_sBIT(png_const_structrp png_ptr, png_inforp info_ptr,
+ png_const_color_8p sig_bit)
+{
+ png_debug1(1, "in %s storage function", "sBIT");
+
+ if (png_ptr == NULL || info_ptr == NULL || sig_bit == NULL)
+ return;
+
+ info_ptr->sig_bit = *sig_bit;
+ info_ptr->valid |= PNG_INFO_sBIT;
+}
+#endif
+
+#ifdef PNG_sRGB_SUPPORTED
+void PNGAPI
+png_set_sRGB(png_const_structrp png_ptr, png_inforp info_ptr, int srgb_intent)
+{
+ png_debug1(1, "in %s storage function", "sRGB");
+
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+ (void)png_colorspace_set_sRGB(png_ptr, &info_ptr->colorspace, srgb_intent);
+ png_colorspace_sync_info(png_ptr, info_ptr);
+}
+
+void PNGAPI
+png_set_sRGB_gAMA_and_cHRM(png_const_structrp png_ptr, png_inforp info_ptr,
+ int srgb_intent)
+{
+ png_debug1(1, "in %s storage function", "sRGB_gAMA_and_cHRM");
+
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+ if (png_colorspace_set_sRGB(png_ptr, &info_ptr->colorspace,
+ srgb_intent) != 0)
+ {
+ /* This causes the gAMA and cHRM to be written too */
+ info_ptr->colorspace.flags |=
+ PNG_COLORSPACE_FROM_gAMA|PNG_COLORSPACE_FROM_cHRM;
+ }
+
+ png_colorspace_sync_info(png_ptr, info_ptr);
+}
+#endif /* sRGB */
+
+
+#ifdef PNG_iCCP_SUPPORTED
+void PNGAPI
+png_set_iCCP(png_const_structrp png_ptr, png_inforp info_ptr,
+ png_const_charp name, int compression_type,
+ png_const_bytep profile, png_uint_32 proflen)
+{
+ png_charp new_iccp_name;
+ png_bytep new_iccp_profile;
+ png_size_t length;
+
+ png_debug1(1, "in %s storage function", "iCCP");
+
+ if (png_ptr == NULL || info_ptr == NULL || name == NULL || profile == NULL)
+ return;
+
+ if (compression_type != PNG_COMPRESSION_TYPE_BASE)
+ png_app_error(png_ptr, "Invalid iCCP compression method");
+
+ /* Set the colorspace first because this validates the profile; do not
+ * override previously set app cHRM or gAMA here (because likely as not the
+ * application knows better than libpng what the correct values are.) Pass
+ * the info_ptr color_type field to png_colorspace_set_ICC because in the
+ * write case it has not yet been stored in png_ptr.
+ */
+ {
+ int result = png_colorspace_set_ICC(png_ptr, &info_ptr->colorspace, name,
+ proflen, profile, info_ptr->color_type);
+
+ png_colorspace_sync_info(png_ptr, info_ptr);
+
+ /* Don't do any of the copying if the profile was bad, or inconsistent. */
+ if (result == 0)
+ return;
+
+ /* But do write the gAMA and cHRM chunks from the profile. */
+ info_ptr->colorspace.flags |=
+ PNG_COLORSPACE_FROM_gAMA|PNG_COLORSPACE_FROM_cHRM;
+ }
+
+ length = strlen(name)+1;
+ new_iccp_name = png_voidcast(png_charp, png_malloc_warn(png_ptr, length));
+
+ if (new_iccp_name == NULL)
+ {
+ png_benign_error(png_ptr, "Insufficient memory to process iCCP chunk");
+
+ return;
+ }
+
+ memcpy(new_iccp_name, name, length);
+ new_iccp_profile = png_voidcast(png_bytep,
+ png_malloc_warn(png_ptr, proflen));
+
+ if (new_iccp_profile == NULL)
+ {
+ png_free(png_ptr, new_iccp_name);
+ png_benign_error(png_ptr,
+ "Insufficient memory to process iCCP profile");
+
+ return;
+ }
+
+ memcpy(new_iccp_profile, profile, proflen);
+
+ png_free_data(png_ptr, info_ptr, PNG_FREE_ICCP, 0);
+
+ info_ptr->iccp_proflen = proflen;
+ info_ptr->iccp_name = new_iccp_name;
+ info_ptr->iccp_profile = new_iccp_profile;
+ info_ptr->free_me |= PNG_FREE_ICCP;
+ info_ptr->valid |= PNG_INFO_iCCP;
+}
+#endif
+
+#ifdef PNG_TEXT_SUPPORTED
+void PNGAPI
+png_set_text(png_const_structrp png_ptr, png_inforp info_ptr,
+ png_const_textp text_ptr, int num_text)
+{
+ int ret;
+ ret = png_set_text_2(png_ptr, info_ptr, text_ptr, num_text);
+
+ if (ret != 0)
+ png_error(png_ptr, "Insufficient memory to store text");
+}
+
+int /* PRIVATE */
+png_set_text_2(png_const_structrp png_ptr, png_inforp info_ptr,
+ png_const_textp text_ptr, int num_text)
+{
+ int i;
+
+ png_debug1(1, "in %lx storage function", png_ptr == NULL ? 0xabadca11U :
+ (unsigned long)png_ptr->chunk_name);
+
+ if (png_ptr == NULL || info_ptr == NULL || num_text <= 0 || text_ptr == NULL)
+ return(0);
+
+ /* Make sure we have enough space in the "text" array in info_struct
+ * to hold all of the incoming text_ptr objects. This compare can't overflow
+ * because max_text >= num_text (anyway, subtract of two positive integers
+ * can't overflow in any case.)
+ */
+ if (num_text > info_ptr->max_text - info_ptr->num_text)
+ {
+ int old_num_text = info_ptr->num_text;
+ int max_text;
+ png_textp new_text = NULL;
+
+ /* Calculate an appropriate max_text, checking for overflow. */
+ max_text = old_num_text;
+ if (num_text <= INT_MAX - max_text)
+ {
+ max_text += num_text;
+
+ /* Round up to a multiple of 8 */
+ if (max_text < INT_MAX-8)
+ max_text = (max_text + 8) & ~0x7;
+
+ else
+ max_text = INT_MAX;
+
+ /* Now allocate a new array and copy the old members in; this does all
+ * the overflow checks.
+ */
+ new_text = png_voidcast(png_textp,png_realloc_array(png_ptr,
+ info_ptr->text, old_num_text, max_text-old_num_text,
+ sizeof *new_text));
+ }
+
+ if (new_text == NULL)
+ {
+ png_chunk_report(png_ptr, "too many text chunks",
+ PNG_CHUNK_WRITE_ERROR);
+
+ return 1;
+ }
+
+ png_free(png_ptr, info_ptr->text);
+
+ info_ptr->text = new_text;
+ info_ptr->free_me |= PNG_FREE_TEXT;
+ info_ptr->max_text = max_text;
+ /* num_text is adjusted below as the entries are copied in */
+
+ png_debug1(3, "allocated %d entries for info_ptr->text", max_text);
+ }
+
+ for (i = 0; i < num_text; i++)
+ {
+ size_t text_length, key_len;
+ size_t lang_len, lang_key_len;
+ png_textp textp = &(info_ptr->text[info_ptr->num_text]);
+
+ if (text_ptr[i].key == NULL)
+ continue;
+
+ if (text_ptr[i].compression < PNG_TEXT_COMPRESSION_NONE ||
+ text_ptr[i].compression >= PNG_TEXT_COMPRESSION_LAST)
+ {
+ png_chunk_report(png_ptr, "text compression mode is out of range",
+ PNG_CHUNK_WRITE_ERROR);
+ continue;
+ }
+
+ key_len = strlen(text_ptr[i].key);
+
+ if (text_ptr[i].compression <= 0)
+ {
+ lang_len = 0;
+ lang_key_len = 0;
+ }
+
+ else
+# ifdef PNG_iTXt_SUPPORTED
+ {
+ /* Set iTXt data */
+
+ if (text_ptr[i].lang != NULL)
+ lang_len = strlen(text_ptr[i].lang);
+
+ else
+ lang_len = 0;
+
+ if (text_ptr[i].lang_key != NULL)
+ lang_key_len = strlen(text_ptr[i].lang_key);
+
+ else
+ lang_key_len = 0;
+ }
+# else /* iTXt */
+ {
+ png_chunk_report(png_ptr, "iTXt chunk not supported",
+ PNG_CHUNK_WRITE_ERROR);
+ continue;
+ }
+# endif
+
+ if (text_ptr[i].text == NULL || text_ptr[i].text[0] == '\0')
+ {
+ text_length = 0;
+# ifdef PNG_iTXt_SUPPORTED
+ if (text_ptr[i].compression > 0)
+ textp->compression = PNG_ITXT_COMPRESSION_NONE;
+
+ else
+# endif
+ textp->compression = PNG_TEXT_COMPRESSION_NONE;
+ }
+
+ else
+ {
+ text_length = strlen(text_ptr[i].text);
+ textp->compression = text_ptr[i].compression;
+ }
+
+ textp->key = png_voidcast(png_charp,png_malloc_base(png_ptr,
+ key_len + text_length + lang_len + lang_key_len + 4));
+
+ if (textp->key == NULL)
+ {
+ png_chunk_report(png_ptr, "text chunk: out of memory",
+ PNG_CHUNK_WRITE_ERROR);
+
+ return 1;
+ }
+
+ png_debug2(2, "Allocated %lu bytes at %p in png_set_text",
+ (unsigned long)(png_uint_32)
+ (key_len + lang_len + lang_key_len + text_length + 4),
+ textp->key);
+
+ memcpy(textp->key, text_ptr[i].key, key_len);
+ *(textp->key + key_len) = '\0';
+
+ if (text_ptr[i].compression > 0)
+ {
+ textp->lang = textp->key + key_len + 1;
+ memcpy(textp->lang, text_ptr[i].lang, lang_len);
+ *(textp->lang + lang_len) = '\0';
+ textp->lang_key = textp->lang + lang_len + 1;
+ memcpy(textp->lang_key, text_ptr[i].lang_key, lang_key_len);
+ *(textp->lang_key + lang_key_len) = '\0';
+ textp->text = textp->lang_key + lang_key_len + 1;
+ }
+
+ else
+ {
+ textp->lang=NULL;
+ textp->lang_key=NULL;
+ textp->text = textp->key + key_len + 1;
+ }
+
+ if (text_length != 0)
+ memcpy(textp->text, text_ptr[i].text, text_length);
+
+ *(textp->text + text_length) = '\0';
+
+# ifdef PNG_iTXt_SUPPORTED
+ if (textp->compression > 0)
+ {
+ textp->text_length = 0;
+ textp->itxt_length = text_length;
+ }
+
+ else
+# endif
+ {
+ textp->text_length = text_length;
+ textp->itxt_length = 0;
+ }
+
+ info_ptr->num_text++;
+ png_debug1(3, "transferred text chunk %d", info_ptr->num_text);
+ }
+
+ return(0);
+}
+#endif
+
+#ifdef PNG_tIME_SUPPORTED
+void PNGAPI
+png_set_tIME(png_const_structrp png_ptr, png_inforp info_ptr,
+ png_const_timep mod_time)
+{
+ png_debug1(1, "in %s storage function", "tIME");
+
+ if (png_ptr == NULL || info_ptr == NULL || mod_time == NULL ||
+ (png_ptr->mode & PNG_WROTE_tIME) != 0)
+ return;
+
+ if (mod_time->month == 0 || mod_time->month > 12 ||
+ mod_time->day == 0 || mod_time->day > 31 ||
+ mod_time->hour > 23 || mod_time->minute > 59 ||
+ mod_time->second > 60)
+ {
+ png_warning(png_ptr, "Ignoring invalid time value");
+
+ return;
+ }
+
+ info_ptr->mod_time = *mod_time;
+ info_ptr->valid |= PNG_INFO_tIME;
+}
+#endif
+
+#ifdef PNG_tRNS_SUPPORTED
+void PNGAPI
+png_set_tRNS(png_structrp png_ptr, png_inforp info_ptr,
+ png_const_bytep trans_alpha, int num_trans, png_const_color_16p trans_color)
+{
+ png_debug1(1, "in %s storage function", "tRNS");
+
+ if (png_ptr == NULL || info_ptr == NULL)
+
+ return;
+
+ if (trans_alpha != NULL)
+ {
+ /* It may not actually be necessary to set png_ptr->trans_alpha here;
+ * we do it for backward compatibility with the way the png_handle_tRNS
+ * function used to do the allocation.
+ *
+ * 1.6.0: The above statement is incorrect; png_handle_tRNS effectively
+ * relies on png_set_tRNS storing the information in png_struct
+ * (otherwise it won't be there for the code in pngrtran.c).
+ */
+
+ png_free_data(png_ptr, info_ptr, PNG_FREE_TRNS, 0);
+
+ /* Changed from num_trans to PNG_MAX_PALETTE_LENGTH in version 1.2.1 */
+ png_ptr->trans_alpha = info_ptr->trans_alpha = png_voidcast(png_bytep,
+ png_malloc(png_ptr, PNG_MAX_PALETTE_LENGTH));
+
+ if (num_trans > 0 && num_trans <= PNG_MAX_PALETTE_LENGTH)
+ memcpy(info_ptr->trans_alpha, trans_alpha, (png_size_t)num_trans);
+ }
+
+ if (trans_color != NULL)
+ {
+#ifdef PNG_WARNINGS_SUPPORTED
+ if (info_ptr->bit_depth < 16)
+ {
+ int sample_max = (1 << info_ptr->bit_depth) - 1;
+
+ if ((info_ptr->color_type == PNG_COLOR_TYPE_GRAY &&
+ trans_color->gray > sample_max) ||
+ (info_ptr->color_type == PNG_COLOR_TYPE_RGB &&
+ (trans_color->red > sample_max ||
+ trans_color->green > sample_max ||
+ trans_color->blue > sample_max)))
+ png_warning(png_ptr,
+ "tRNS chunk has out-of-range samples for bit_depth");
+ }
+#endif
+
+ info_ptr->trans_color = *trans_color;
+
+ if (num_trans == 0)
+ num_trans = 1;
+ }
+
+ info_ptr->num_trans = (png_uint_16)num_trans;
+
+ if (num_trans != 0)
+ {
+ info_ptr->valid |= PNG_INFO_tRNS;
+ info_ptr->free_me |= PNG_FREE_TRNS;
+ }
+}
+#endif
+
+#ifdef PNG_sPLT_SUPPORTED
+void PNGAPI
+png_set_sPLT(png_const_structrp png_ptr,
+ png_inforp info_ptr, png_const_sPLT_tp entries, int nentries)
+/*
+ * entries - array of png_sPLT_t structures
+ * to be added to the list of palettes
+ * in the info structure.
+ *
+ * nentries - number of palette structures to be
+ * added.
+ */
+{
+ png_sPLT_tp np;
+
+ if (png_ptr == NULL || info_ptr == NULL || nentries <= 0 || entries == NULL)
+ return;
+
+ /* Use the internal realloc function, which checks for all the possible
+ * overflows. Notice that the parameters are (int) and (size_t)
+ */
+ np = png_voidcast(png_sPLT_tp,png_realloc_array(png_ptr,
+ info_ptr->splt_palettes, info_ptr->splt_palettes_num, nentries,
+ sizeof *np));
+
+ if (np == NULL)
+ {
+ /* Out of memory or too many chunks */
+ png_chunk_report(png_ptr, "too many sPLT chunks", PNG_CHUNK_WRITE_ERROR);
+
+ return;
+ }
+
+ png_free(png_ptr, info_ptr->splt_palettes);
+ info_ptr->splt_palettes = np;
+ info_ptr->free_me |= PNG_FREE_SPLT;
+
+ np += info_ptr->splt_palettes_num;
+
+ do
+ {
+ png_size_t length;
+
+ /* Skip invalid input entries */
+ if (entries->name == NULL || entries->entries == NULL)
+ {
+ /* png_handle_sPLT doesn't do this, so this is an app error */
+ png_app_error(png_ptr, "png_set_sPLT: invalid sPLT");
+ /* Just skip the invalid entry */
+ continue;
+ }
+
+ np->depth = entries->depth;
+
+ /* In the event of out-of-memory just return - there's no point keeping
+ * on trying to add sPLT chunks.
+ */
+ length = strlen(entries->name) + 1;
+ np->name = png_voidcast(png_charp, png_malloc_base(png_ptr, length));
+
+ if (np->name == NULL)
+ break;
+
+ memcpy(np->name, entries->name, length);
+
+ /* IMPORTANT: we have memory now that won't get freed if something else
+ * goes wrong; this code must free it. png_malloc_array produces no
+ * warnings; use a png_chunk_report (below) if there is an error.
+ */
+ np->entries = png_voidcast(png_sPLT_entryp, png_malloc_array(png_ptr,
+ entries->nentries, sizeof (png_sPLT_entry)));
+
+ if (np->entries == NULL)
+ {
+ png_free(png_ptr, np->name);
+ np->name = NULL;
+ break;
+ }
+
+ np->nentries = entries->nentries;
+ /* This multiply can't overflow because png_malloc_array has already
+ * checked it when doing the allocation.
+ */
+ memcpy(np->entries, entries->entries,
+ entries->nentries * sizeof (png_sPLT_entry));
+
+ /* Note that 'continue' skips the advance of the out pointer and out
+ * count, so an invalid entry is not added.
+ */
+ info_ptr->valid |= PNG_INFO_sPLT;
+ ++(info_ptr->splt_palettes_num);
+ ++np;
+ }
+ while (++entries, --nentries);
+
+ if (nentries > 0)
+ png_chunk_report(png_ptr, "sPLT out of memory", PNG_CHUNK_WRITE_ERROR);
+}
+#endif /* sPLT */
+
+#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
+static png_byte
+check_location(png_const_structrp png_ptr, int location)
+{
+ location &= (PNG_HAVE_IHDR|PNG_HAVE_PLTE|PNG_AFTER_IDAT);
+
+ /* New in 1.6.0; copy the location and check it. This is an API
+ * change; previously the app had to use the
+ * png_set_unknown_chunk_location API below for each chunk.
+ */
+ if (location == 0 && (png_ptr->mode & PNG_IS_READ_STRUCT) == 0)
+ {
+ /* Write struct, so unknown chunks come from the app */
+ png_app_warning(png_ptr,
+ "png_set_unknown_chunks now expects a valid location");
+ /* Use the old behavior */
+ location = (png_byte)(png_ptr->mode &
+ (PNG_HAVE_IHDR|PNG_HAVE_PLTE|PNG_AFTER_IDAT));
+ }
+
+ /* This need not be an internal error - if the app calls
+ * png_set_unknown_chunks on a read pointer it must get the location right.
+ */
+ if (location == 0)
+ png_error(png_ptr, "invalid location in png_set_unknown_chunks");
+
+ /* Now reduce the location to the top-most set bit by removing each least
+ * significant bit in turn.
+ */
+ while (location != (location & -location))
+ location &= ~(location & -location);
+
+ /* The cast is safe because 'location' is a bit mask and only the low four
+ * bits are significant.
+ */
+ return (png_byte)location;
+}
+
+void PNGAPI
+png_set_unknown_chunks(png_const_structrp png_ptr,
+ png_inforp info_ptr, png_const_unknown_chunkp unknowns, int num_unknowns)
+{
+ png_unknown_chunkp np;
+
+ if (png_ptr == NULL || info_ptr == NULL || num_unknowns <= 0 ||
+ unknowns == NULL)
+ return;
+
+ /* Check for the failure cases where support has been disabled at compile
+ * time. This code is hardly ever compiled - it's here because
+ * STORE_UNKNOWN_CHUNKS is set by both read and write code (compiling in this
+ * code) but may be meaningless if the read or write handling of unknown
+ * chunks is not compiled in.
+ */
+# if !defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED) && \
+ defined(PNG_READ_SUPPORTED)
+ if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0)
+ {
+ png_app_error(png_ptr, "no unknown chunk support on read");
+
+ return;
+ }
+# endif
+# if !defined(PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED) && \
+ defined(PNG_WRITE_SUPPORTED)
+ if ((png_ptr->mode & PNG_IS_READ_STRUCT) == 0)
+ {
+ png_app_error(png_ptr, "no unknown chunk support on write");
+
+ return;
+ }
+# endif
+
+ /* Prior to 1.6.0 this code used png_malloc_warn; however, this meant that
+ * unknown critical chunks could be lost with just a warning resulting in
+ * undefined behavior. Now png_chunk_report is used to provide behavior
+ * appropriate to read or write.
+ */
+ np = png_voidcast(png_unknown_chunkp, png_realloc_array(png_ptr,
+ info_ptr->unknown_chunks, info_ptr->unknown_chunks_num, num_unknowns,
+ sizeof *np));
+
+ if (np == NULL)
+ {
+ png_chunk_report(png_ptr, "too many unknown chunks",
+ PNG_CHUNK_WRITE_ERROR);
+
+ return;
+ }
+
+ png_free(png_ptr, info_ptr->unknown_chunks);
+ info_ptr->unknown_chunks = np; /* safe because it is initialized */
+ info_ptr->free_me |= PNG_FREE_UNKN;
+
+ np += info_ptr->unknown_chunks_num;
+
+ /* Increment unknown_chunks_num each time round the loop to protect the
+ * just-allocated chunk data.
+ */
+ for (; num_unknowns > 0; --num_unknowns, ++unknowns)
+ {
+ memcpy(np->name, unknowns->name, (sizeof np->name));
+ np->name[(sizeof np->name)-1] = '\0';
+ np->location = check_location(png_ptr, unknowns->location);
+
+ if (unknowns->size == 0)
+ {
+ np->data = NULL;
+ np->size = 0;
+ }
+
+ else
+ {
+ np->data = png_voidcast(png_bytep,
+ png_malloc_base(png_ptr, unknowns->size));
+
+ if (np->data == NULL)
+ {
+ png_chunk_report(png_ptr, "unknown chunk: out of memory",
+ PNG_CHUNK_WRITE_ERROR);
+ /* But just skip storing the unknown chunk */
+ continue;
+ }
+
+ memcpy(np->data, unknowns->data, unknowns->size);
+ np->size = unknowns->size;
+ }
+
+ /* These increments are skipped on out-of-memory for the data - the
+ * unknown chunk entry gets overwritten if the png_chunk_report returns.
+ * This is correct in the read case (the chunk is just dropped.)
+ */
+ ++np;
+ ++(info_ptr->unknown_chunks_num);
+ }
+}
+
+void PNGAPI
+png_set_unknown_chunk_location(png_const_structrp png_ptr, png_inforp info_ptr,
+ int chunk, int location)
+{
+ /* This API is pretty pointless in 1.6.0 because the location can be set
+ * before the call to png_set_unknown_chunks.
+ *
+ * TODO: add a png_app_warning in 1.7
+ */
+ if (png_ptr != NULL && info_ptr != NULL && chunk >= 0 &&
+ chunk < info_ptr->unknown_chunks_num)
+ {
+ if ((location & (PNG_HAVE_IHDR|PNG_HAVE_PLTE|PNG_AFTER_IDAT)) == 0)
+ {
+ png_app_error(png_ptr, "invalid unknown chunk location");
+ /* Fake out the pre 1.6.0 behavior: */
+ if ((location & PNG_HAVE_IDAT) != 0) /* undocumented! */
+ location = PNG_AFTER_IDAT;
+
+ else
+ location = PNG_HAVE_IHDR; /* also undocumented */
+ }
+
+ info_ptr->unknown_chunks[chunk].location =
+ check_location(png_ptr, location);
+ }
+}
+#endif /* STORE_UNKNOWN_CHUNKS */
+
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+png_uint_32 PNGAPI
+png_permit_mng_features (png_structrp png_ptr, png_uint_32 mng_features)
+{
+ png_debug(1, "in png_permit_mng_features");
+
+ if (png_ptr == NULL)
+ return 0;
+
+ png_ptr->mng_features_permitted = mng_features & PNG_ALL_MNG_FEATURES;
+
+ return png_ptr->mng_features_permitted;
+}
+#endif
+
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+static unsigned int
+add_one_chunk(png_bytep list, unsigned int count, png_const_bytep add, int keep)
+{
+ unsigned int i;
+
+ /* Utility function: update the 'keep' state of a chunk if it is already in
+ * the list, otherwise add it to the list.
+ */
+ for (i=0; i<count; ++i, list += 5)
+ {
+ if (memcmp(list, add, 4) == 0)
+ {
+ list[4] = (png_byte)keep;
+
+ return count;
+ }
+ }
+
+ if (keep != PNG_HANDLE_CHUNK_AS_DEFAULT)
+ {
+ ++count;
+ memcpy(list, add, 4);
+ list[4] = (png_byte)keep;
+ }
+
+ return count;
+}
+
+void PNGAPI
+png_set_keep_unknown_chunks(png_structrp png_ptr, int keep,
+ png_const_bytep chunk_list, int num_chunks_in)
+{
+ png_bytep new_list;
+ unsigned int num_chunks, old_num_chunks;
+
+ if (png_ptr == NULL)
+ return;
+
+ if (keep < 0 || keep >= PNG_HANDLE_CHUNK_LAST)
+ {
+ png_app_error(png_ptr, "png_set_keep_unknown_chunks: invalid keep");
+
+ return;
+ }
+
+ if (num_chunks_in <= 0)
+ {
+ png_ptr->unknown_default = keep;
+
+ /* '0' means just set the flags, so stop here */
+ if (num_chunks_in == 0)
+ return;
+ }
+
+ if (num_chunks_in < 0)
+ {
+ /* Ignore all unknown chunks and all chunks recognized by
+ * libpng except for IHDR, PLTE, tRNS, IDAT, and IEND
+ */
+ static PNG_CONST png_byte chunks_to_ignore[] = {
+ 98, 75, 71, 68, '\0', /* bKGD */
+ 99, 72, 82, 77, '\0', /* cHRM */
+ 103, 65, 77, 65, '\0', /* gAMA */
+ 104, 73, 83, 84, '\0', /* hIST */
+ 105, 67, 67, 80, '\0', /* iCCP */
+ 105, 84, 88, 116, '\0', /* iTXt */
+ 111, 70, 70, 115, '\0', /* oFFs */
+ 112, 67, 65, 76, '\0', /* pCAL */
+ 112, 72, 89, 115, '\0', /* pHYs */
+ 115, 66, 73, 84, '\0', /* sBIT */
+ 115, 67, 65, 76, '\0', /* sCAL */
+ 115, 80, 76, 84, '\0', /* sPLT */
+ 115, 84, 69, 82, '\0', /* sTER */
+ 115, 82, 71, 66, '\0', /* sRGB */
+ 116, 69, 88, 116, '\0', /* tEXt */
+ 116, 73, 77, 69, '\0', /* tIME */
+ 122, 84, 88, 116, '\0' /* zTXt */
+ };
+
+ chunk_list = chunks_to_ignore;
+ num_chunks = (unsigned int)/*SAFE*/(sizeof chunks_to_ignore)/5U;
+ }
+
+ else /* num_chunks_in > 0 */
+ {
+ if (chunk_list == NULL)
+ {
+ /* Prior to 1.6.0 this was silently ignored, now it is an app_error
+ * which can be switched off.
+ */
+ png_app_error(png_ptr, "png_set_keep_unknown_chunks: no chunk list");
+
+ return;
+ }
+
+ num_chunks = num_chunks_in;
+ }
+
+ old_num_chunks = png_ptr->num_chunk_list;
+ if (png_ptr->chunk_list == NULL)
+ old_num_chunks = 0;
+
+ /* Since num_chunks is always restricted to UINT_MAX/5 this can't overflow.
+ */
+ if (num_chunks + old_num_chunks > UINT_MAX/5)
+ {
+ png_app_error(png_ptr, "png_set_keep_unknown_chunks: too many chunks");
+
+ return;
+ }
+
+ /* If these chunks are being reset to the default then no more memory is
+ * required because add_one_chunk above doesn't extend the list if the 'keep'
+ * parameter is the default.
+ */
+ if (keep != 0)
+ {
+ new_list = png_voidcast(png_bytep, png_malloc(png_ptr,
+ 5 * (num_chunks + old_num_chunks)));
+
+ if (old_num_chunks > 0)
+ memcpy(new_list, png_ptr->chunk_list, 5*old_num_chunks);
+ }
+
+ else if (old_num_chunks > 0)
+ new_list = png_ptr->chunk_list;
+
+ else
+ new_list = NULL;
+
+ /* Add the new chunks together with each one's handling code. If the chunk
+ * already exists the code is updated, otherwise the chunk is added to the
+ * end. (In libpng 1.6.0 order no longer matters because this code enforces
+ * the earlier convention that the last setting is the one that is used.)
+ */
+ if (new_list != NULL)
+ {
+ png_const_bytep inlist;
+ png_bytep outlist;
+ unsigned int i;
+
+ for (i=0; i<num_chunks; ++i)
+ {
+ old_num_chunks = add_one_chunk(new_list, old_num_chunks,
+ chunk_list+5*i, keep);
+ }
+
+ /* Now remove any spurious 'default' entries. */
+ num_chunks = 0;
+ for (i=0, inlist=outlist=new_list; i<old_num_chunks; ++i, inlist += 5)
+ {
+ if (inlist[4])
+ {
+ if (outlist != inlist)
+ memcpy(outlist, inlist, 5);
+ outlist += 5;
+ ++num_chunks;
+ }
+ }
+
+ /* This means the application has removed all the specialized handling. */
+ if (num_chunks == 0)
+ {
+ if (png_ptr->chunk_list != new_list)
+ png_free(png_ptr, new_list);
+
+ new_list = NULL;
+ }
+ }
+
+ else
+ num_chunks = 0;
+
+ png_ptr->num_chunk_list = num_chunks;
+
+ if (png_ptr->chunk_list != new_list)
+ {
+ if (png_ptr->chunk_list != NULL)
+ png_free(png_ptr, png_ptr->chunk_list);
+
+ png_ptr->chunk_list = new_list;
+ }
+}
+#endif
+
+#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
+void PNGAPI
+png_set_read_user_chunk_fn(png_structrp png_ptr, png_voidp user_chunk_ptr,
+ png_user_chunk_ptr read_user_chunk_fn)
+{
+ png_debug(1, "in png_set_read_user_chunk_fn");
+
+ if (png_ptr == NULL)
+ return;
+
+ png_ptr->read_user_chunk_fn = read_user_chunk_fn;
+ png_ptr->user_chunk_ptr = user_chunk_ptr;
+}
+#endif
+
+#ifdef PNG_INFO_IMAGE_SUPPORTED
+void PNGAPI
+png_set_rows(png_const_structrp png_ptr, png_inforp info_ptr,
+ png_bytepp row_pointers)
+{
+ png_debug1(1, "in %s storage function", "rows");
+
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+ if (info_ptr->row_pointers != NULL &&
+ (info_ptr->row_pointers != row_pointers))
+ png_free_data(png_ptr, info_ptr, PNG_FREE_ROWS, 0);
+
+ info_ptr->row_pointers = row_pointers;
+
+ if (row_pointers != NULL)
+ info_ptr->valid |= PNG_INFO_IDAT;
+}
+#endif
+
+void PNGAPI
+png_set_compression_buffer_size(png_structrp png_ptr, png_size_t size)
+{
+ if (png_ptr == NULL)
+ return;
+
+ if (size == 0 || size > PNG_UINT_31_MAX)
+ png_error(png_ptr, "invalid compression buffer size");
+
+# ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+ if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0)
+ {
+ png_ptr->IDAT_read_size = (png_uint_32)size; /* checked above */
+ return;
+ }
+# endif
+
+# ifdef PNG_WRITE_SUPPORTED
+ if ((png_ptr->mode & PNG_IS_READ_STRUCT) == 0)
+ {
+ if (png_ptr->zowner != 0)
+ {
+ png_warning(png_ptr,
+ "Compression buffer size cannot be changed because it is in use");
+
+ return;
+ }
+
+#ifndef __COVERITY__
+ /* Some compilers complain that this is always false. However, it
+ * can be true when integer overflow happens.
+ */
+ if (size > ZLIB_IO_MAX)
+ {
+ png_warning(png_ptr,
+ "Compression buffer size limited to system maximum");
+ size = ZLIB_IO_MAX; /* must fit */
+ }
+#endif
+
+ if (size < 6)
+ {
+ /* Deflate will potentially go into an infinite loop on a SYNC_FLUSH
+ * if this is permitted.
+ */
+ png_warning(png_ptr,
+ "Compression buffer size cannot be reduced below 6");
+
+ return;
+ }
+
+ if (png_ptr->zbuffer_size != size)
+ {
+ png_free_buffer_list(png_ptr, &png_ptr->zbuffer_list);
+ png_ptr->zbuffer_size = (uInt)size;
+ }
+ }
+# endif
+}
+
+void PNGAPI
+png_set_invalid(png_const_structrp png_ptr, png_inforp info_ptr, int mask)
+{
+ if (png_ptr != NULL && info_ptr != NULL)
+ info_ptr->valid &= ~mask;
+}
+
+
+#ifdef PNG_SET_USER_LIMITS_SUPPORTED
+/* This function was added to libpng 1.2.6 */
+void PNGAPI
+png_set_user_limits (png_structrp png_ptr, png_uint_32 user_width_max,
+ png_uint_32 user_height_max)
+{
+ /* Images with dimensions larger than these limits will be
+ * rejected by png_set_IHDR(). To accept any PNG datastream
+ * regardless of dimensions, set both limits to 0x7fffffff.
+ */
+ if (png_ptr == NULL)
+ return;
+
+ png_ptr->user_width_max = user_width_max;
+ png_ptr->user_height_max = user_height_max;
+}
+
+/* This function was added to libpng 1.4.0 */
+void PNGAPI
+png_set_chunk_cache_max (png_structrp png_ptr, png_uint_32 user_chunk_cache_max)
+{
+ if (png_ptr != NULL)
+ png_ptr->user_chunk_cache_max = user_chunk_cache_max;
+}
+
+/* This function was added to libpng 1.4.1 */
+void PNGAPI
+png_set_chunk_malloc_max (png_structrp png_ptr,
+ png_alloc_size_t user_chunk_malloc_max)
+{
+ if (png_ptr != NULL)
+ png_ptr->user_chunk_malloc_max = user_chunk_malloc_max;
+}
+#endif /* ?SET_USER_LIMITS */
+
+
+#ifdef PNG_BENIGN_ERRORS_SUPPORTED
+void PNGAPI
+png_set_benign_errors(png_structrp png_ptr, int allowed)
+{
+ png_debug(1, "in png_set_benign_errors");
+
+ /* If allowed is 1, png_benign_error() is treated as a warning.
+ *
+ * If allowed is 0, png_benign_error() is treated as an error (which
+ * is the default behavior if png_set_benign_errors() is not called).
+ */
+
+ if (allowed != 0)
+ png_ptr->flags |= PNG_FLAG_BENIGN_ERRORS_WARN |
+ PNG_FLAG_APP_WARNINGS_WARN | PNG_FLAG_APP_ERRORS_WARN;
+
+ else
+ png_ptr->flags &= ~(PNG_FLAG_BENIGN_ERRORS_WARN |
+ PNG_FLAG_APP_WARNINGS_WARN | PNG_FLAG_APP_ERRORS_WARN);
+}
+#endif /* BENIGN_ERRORS */
+
+#ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED
+ /* Whether to report invalid palette index; added at libng-1.5.10.
+ * It is possible for an indexed (color-type==3) PNG file to contain
+ * pixels with invalid (out-of-range) indexes if the PLTE chunk has
+ * fewer entries than the image's bit-depth would allow. We recover
+ * from this gracefully by filling any incomplete palette with zeros
+ * (opaque black). By default, when this occurs libpng will issue
+ * a benign error. This API can be used to override that behavior.
+ */
+void PNGAPI
+png_set_check_for_invalid_index(png_structrp png_ptr, int allowed)
+{
+ png_debug(1, "in png_set_check_for_invalid_index");
+
+ if (allowed > 0)
+ png_ptr->num_palette_max = 0;
+
+ else
+ png_ptr->num_palette_max = -1;
+}
+#endif
+#endif /* READ || WRITE */
diff --git a/third_party/lpng_v163/pngstruct.h b/third_party/libpng/pngstruct.h
similarity index 93%
rename from third_party/lpng_v163/pngstruct.h
rename to third_party/libpng/pngstruct.h
index 87adaa1..ad1e7a5 100644
--- a/third_party/lpng_v163/pngstruct.h
+++ b/third_party/libpng/pngstruct.h
@@ -1,489 +1,483 @@
-
-/* pngstruct.h - header file for PNG reference library
- *
- * Copyright (c) 1998-2013 Glenn Randers-Pehrson
- * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
- * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
- *
- * Last changed in libpng 1.6.1 [March 28, 2013]
- *
- * This code is released under the libpng license.
- * For conditions of distribution and use, see the disclaimer
- * and license in png.h
- */
-
-/* The structure that holds the information to read and write PNG files.
- * The only people who need to care about what is inside of this are the
- * people who will be modifying the library for their own special needs.
- * It should NOT be accessed directly by an application.
- */
-
-#ifndef PNGSTRUCT_H
-#define PNGSTRUCT_H
-/* zlib.h defines the structure z_stream, an instance of which is included
- * in this structure and is required for decompressing the LZ compressed
- * data in PNG files.
- */
-#ifndef ZLIB_CONST
- /* We must ensure that zlib uses 'const' in declarations. */
-# define ZLIB_CONST
-#endif
-#include "third_party/zlib_v128/zlib.h"
-#ifdef const
- /* zlib.h sometimes #defines const to nothing, undo this. */
-# undef const
-#endif
-
-/* zlib.h has mediocre z_const use before 1.2.6, this stuff is for compatibility
- * with older builds.
- */
-#if ZLIB_VERNUM < 0x1260
-# define PNGZ_MSG_CAST(s) png_constcast(char*,s)
-# define PNGZ_INPUT_CAST(b) png_constcast(png_bytep,b)
-#else
-# define PNGZ_MSG_CAST(s) (s)
-# define PNGZ_INPUT_CAST(b) (b)
-#endif
-
-/* zlib.h declares a magic type 'uInt' that limits the amount of data that zlib
- * can handle at once. This type need be no larger than 16 bits (so maximum of
- * 65535), this define allows us to discover how big it is, but limited by the
- * maximuum for png_size_t. The value can be overriden in a library build
- * (pngusr.h, or set it in CPPFLAGS) and it works to set it to a considerably
- * lower value (e.g. 255 works). A lower value may help memory usage (slightly)
- * and may even improve performance on some systems (and degrade it on others.)
- */
-#ifndef ZLIB_IO_MAX
-# define ZLIB_IO_MAX ((uInt)-1)
-#endif
-
-#ifdef PNG_WRITE_SUPPORTED
-/* The type of a compression buffer list used by the write code. */
-typedef struct png_compression_buffer
-{
- struct png_compression_buffer *next;
- png_byte output[1]; /* actually zbuf_size */
-} png_compression_buffer, *png_compression_bufferp;
-
-#define PNG_COMPRESSION_BUFFER_SIZE(pp)\
- (offsetof(png_compression_buffer, output) + (pp)->zbuffer_size)
-#endif
-
-/* Colorspace support; structures used in png_struct, png_info and in internal
- * functions to hold and communicate information about the color space.
- *
- * PNG_COLORSPACE_SUPPORTED is only required if the application will perform
- * colorspace corrections, otherwise all the colorspace information can be
- * skipped and the size of libpng can be reduced (significantly) by compiling
- * out the colorspace support.
- */
-#ifdef PNG_COLORSPACE_SUPPORTED
-/* The chromaticities of the red, green and blue colorants and the chromaticity
- * of the corresponding white point (i.e. of rgb(1.0,1.0,1.0)).
- */
-typedef struct png_xy
-{
- png_fixed_point redx, redy;
- png_fixed_point greenx, greeny;
- png_fixed_point bluex, bluey;
- png_fixed_point whitex, whitey;
-} png_xy;
-
-/* The same data as above but encoded as CIE XYZ values. When this data comes
- * from chromaticities the sum of the Y values is assumed to be 1.0
- */
-typedef struct png_XYZ
-{
- png_fixed_point red_X, red_Y, red_Z;
- png_fixed_point green_X, green_Y, green_Z;
- png_fixed_point blue_X, blue_Y, blue_Z;
-} png_XYZ;
-#endif /* COLORSPACE */
-
-#if defined(PNG_COLORSPACE_SUPPORTED) || defined(PNG_GAMMA_SUPPORTED)
-/* A colorspace is all the above plus, potentially, profile information,
- * however at present libpng does not use the profile internally so it is only
- * stored in the png_info struct (if iCCP is supported.) The rendering intent
- * is retained here and is checked.
- *
- * The file gamma encoding information is also stored here and gamma correction
- * is done by libpng, whereas color correction must currently be done by the
- * application.
- */
-typedef struct png_colorspace
-{
-#ifdef PNG_GAMMA_SUPPORTED
- png_fixed_point gamma; /* File gamma */
-#endif
-
-#ifdef PNG_COLORSPACE_SUPPORTED
- png_xy end_points_xy; /* End points as chromaticities */
- png_XYZ end_points_XYZ; /* End points as CIE XYZ colorant values */
- png_uint_16 rendering_intent; /* Rendering intent of a profile */
-#endif
-
- /* Flags are always defined to simplify the code. */
- png_uint_16 flags; /* As defined below */
-} png_colorspace, * PNG_RESTRICT png_colorspacerp;
-
-typedef const png_colorspace * PNG_RESTRICT png_const_colorspacerp;
-
-/* General flags for the 'flags' field */
-#define PNG_COLORSPACE_HAVE_GAMMA 0x0001
-#define PNG_COLORSPACE_HAVE_ENDPOINTS 0x0002
-#define PNG_COLORSPACE_HAVE_INTENT 0x0004
-#define PNG_COLORSPACE_FROM_gAMA 0x0008
-#define PNG_COLORSPACE_FROM_cHRM 0x0010
-#define PNG_COLORSPACE_FROM_sRGB 0x0020
-#define PNG_COLORSPACE_ENDPOINTS_MATCH_sRGB 0x0040
-#define PNG_COLORSPACE_MATCHES_sRGB 0x0080 /* exact match on profile */
-#define PNG_COLORSPACE_INVALID 0x8000
-#define PNG_COLORSPACE_CANCEL(flags) (0xffff ^ (flags))
-#endif /* COLORSPACE || GAMMA */
-
-struct png_struct_def
-{
-#ifdef PNG_SETJMP_SUPPORTED
- jmp_buf jmp_buf_local; /* New name in 1.6.0 for jmp_buf in png_struct */
- png_longjmp_ptr longjmp_fn;/* setjmp non-local goto function. */
- jmp_buf *jmp_buf_ptr; /* passed to longjmp_fn */
- size_t jmp_buf_size; /* size of the above, if allocated */
-#endif
- png_error_ptr error_fn; /* function for printing errors and aborting */
-#ifdef PNG_WARNINGS_SUPPORTED
- png_error_ptr warning_fn; /* function for printing warnings */
-#endif
- png_voidp error_ptr; /* user supplied struct for error functions */
- png_rw_ptr write_data_fn; /* function for writing output data */
- png_rw_ptr read_data_fn; /* function for reading input data */
- png_voidp io_ptr; /* ptr to application struct for I/O functions */
-
-#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
- png_user_transform_ptr read_user_transform_fn; /* user read transform */
-#endif
-
-#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
- png_user_transform_ptr write_user_transform_fn; /* user write transform */
-#endif
-
-/* These were added in libpng-1.0.2 */
-#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
-#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
- defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
- png_voidp user_transform_ptr; /* user supplied struct for user transform */
- png_byte user_transform_depth; /* bit depth of user transformed pixels */
- png_byte user_transform_channels; /* channels in user transformed pixels */
-#endif
-#endif
-
- png_uint_32 mode; /* tells us where we are in the PNG file */
- png_uint_32 flags; /* flags indicating various things to libpng */
- png_uint_32 transformations; /* which transformations to perform */
-
- png_uint_32 zowner; /* ID (chunk type) of zstream owner, 0 if none */
- z_stream zstream; /* decompression structure */
-
-#ifdef PNG_WRITE_SUPPORTED
- png_compression_bufferp zbuffer_list; /* Created on demand during write */
- uInt zbuffer_size; /* size of the actual buffer */
-
- int zlib_level; /* holds zlib compression level */
- int zlib_method; /* holds zlib compression method */
- int zlib_window_bits; /* holds zlib compression window bits */
- int zlib_mem_level; /* holds zlib compression memory level */
- int zlib_strategy; /* holds zlib compression strategy */
-#endif
-/* Added at libpng 1.5.4 */
-#ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
- int zlib_text_level; /* holds zlib compression level */
- int zlib_text_method; /* holds zlib compression method */
- int zlib_text_window_bits; /* holds zlib compression window bits */
- int zlib_text_mem_level; /* holds zlib compression memory level */
- int zlib_text_strategy; /* holds zlib compression strategy */
-#endif
-/* End of material added at libpng 1.5.4 */
-/* Added at libpng 1.6.0 */
-#ifdef PNG_WRITE_SUPPORTED
- int zlib_set_level; /* Actual values set into the zstream on write */
- int zlib_set_method;
- int zlib_set_window_bits;
- int zlib_set_mem_level;
- int zlib_set_strategy;
-#endif
-
- png_uint_32 width; /* width of image in pixels */
- png_uint_32 height; /* height of image in pixels */
- png_uint_32 num_rows; /* number of rows in current pass */
- png_uint_32 usr_width; /* width of row at start of write */
- png_size_t rowbytes; /* size of row in bytes */
- png_uint_32 iwidth; /* width of current interlaced row in pixels */
- png_uint_32 row_number; /* current row in interlace pass */
- png_uint_32 chunk_name; /* PNG_CHUNK() id of current chunk */
- png_bytep prev_row; /* buffer to save previous (unfiltered) row.
- * This is a pointer into big_prev_row
- */
- png_bytep row_buf; /* buffer to save current (unfiltered) row.
- * This is a pointer into big_row_buf
- */
-#ifdef PNG_WRITE_SUPPORTED
- png_bytep sub_row; /* buffer to save "sub" row when filtering */
- png_bytep up_row; /* buffer to save "up" row when filtering */
- png_bytep avg_row; /* buffer to save "avg" row when filtering */
- png_bytep paeth_row; /* buffer to save "Paeth" row when filtering */
-#endif
- png_size_t info_rowbytes; /* Added in 1.5.4: cache of updated row bytes */
-
- png_uint_32 idat_size; /* current IDAT size for read */
- png_uint_32 crc; /* current chunk CRC value */
- png_colorp palette; /* palette from the input file */
- png_uint_16 num_palette; /* number of color entries in palette */
-
-/* Added at libpng-1.5.10 */
-#ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED
- int num_palette_max; /* maximum palette index found in IDAT */
-#endif
-
- png_uint_16 num_trans; /* number of transparency values */
- png_byte compression; /* file compression type (always 0) */
- png_byte filter; /* file filter type (always 0) */
- png_byte interlaced; /* PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */
- png_byte pass; /* current interlace pass (0 - 6) */
- png_byte do_filter; /* row filter flags (see PNG_FILTER_ below ) */
- png_byte color_type; /* color type of file */
- png_byte bit_depth; /* bit depth of file */
- png_byte usr_bit_depth; /* bit depth of users row: write only */
- png_byte pixel_depth; /* number of bits per pixel */
- png_byte channels; /* number of channels in file */
-#ifdef PNG_WRITE_SUPPORTED
- png_byte usr_channels; /* channels at start of write: write only */
-#endif
- png_byte sig_bytes; /* magic bytes read/written from start of file */
- png_byte maximum_pixel_depth;
- /* pixel depth used for the row buffers */
- png_byte transformed_pixel_depth;
- /* pixel depth after read/write transforms */
-#if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
- png_uint_16 filler; /* filler bytes for pixel expansion */
-#endif
-
-#if defined(PNG_bKGD_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) ||\
- defined(PNG_READ_ALPHA_MODE_SUPPORTED)
- png_byte background_gamma_type;
- png_fixed_point background_gamma;
- png_color_16 background; /* background color in screen gamma space */
-#ifdef PNG_READ_GAMMA_SUPPORTED
- png_color_16 background_1; /* background normalized to gamma 1.0 */
-#endif
-#endif /* PNG_bKGD_SUPPORTED */
-
-#ifdef PNG_WRITE_FLUSH_SUPPORTED
- png_flush_ptr output_flush_fn; /* Function for flushing output */
- png_uint_32 flush_dist; /* how many rows apart to flush, 0 - no flush */
- png_uint_32 flush_rows; /* number of rows written since last flush */
-#endif
-
-#ifdef PNG_READ_GAMMA_SUPPORTED
- int gamma_shift; /* number of "insignificant" bits in 16-bit gamma */
- png_fixed_point screen_gamma; /* screen gamma value (display_exponent) */
-
- png_bytep gamma_table; /* gamma table for 8-bit depth files */
- png_uint_16pp gamma_16_table; /* gamma table for 16-bit depth files */
-#if defined(PNG_READ_BACKGROUND_SUPPORTED) || \
- defined(PNG_READ_ALPHA_MODE_SUPPORTED) || \
- defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
- png_bytep gamma_from_1; /* converts from 1.0 to screen */
- png_bytep gamma_to_1; /* converts from file to 1.0 */
- png_uint_16pp gamma_16_from_1; /* converts from 1.0 to screen */
- png_uint_16pp gamma_16_to_1; /* converts from file to 1.0 */
-#endif /* READ_BACKGROUND || READ_ALPHA_MODE || RGB_TO_GRAY */
-#endif
-
-#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_sBIT_SUPPORTED)
- png_color_8 sig_bit; /* significant bits in each available channel */
-#endif
-
-#if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
- png_color_8 shift; /* shift for significant bit tranformation */
-#endif
-
-#if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) \
- || defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
- png_bytep trans_alpha; /* alpha values for paletted files */
- png_color_16 trans_color; /* transparent color for non-paletted files */
-#endif
-
- png_read_status_ptr read_row_fn; /* called after each row is decoded */
- png_write_status_ptr write_row_fn; /* called after each row is encoded */
-#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
- png_progressive_info_ptr info_fn; /* called after header data fully read */
- png_progressive_row_ptr row_fn; /* called after a prog. row is decoded */
- png_progressive_end_ptr end_fn; /* called after image is complete */
- png_bytep save_buffer_ptr; /* current location in save_buffer */
- png_bytep save_buffer; /* buffer for previously read data */
- png_bytep current_buffer_ptr; /* current location in current_buffer */
- png_bytep current_buffer; /* buffer for recently used data */
- png_uint_32 push_length; /* size of current input chunk */
- png_uint_32 skip_length; /* bytes to skip in input data */
- png_size_t save_buffer_size; /* amount of data now in save_buffer */
- png_size_t save_buffer_max; /* total size of save_buffer */
- png_size_t buffer_size; /* total amount of available input data */
- png_size_t current_buffer_size; /* amount of data now in current_buffer */
- int process_mode; /* what push library is currently doing */
- int cur_palette; /* current push library palette index */
-
-#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
-
-#if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__)
-/* For the Borland special 64K segment handler */
- png_bytepp offset_table_ptr;
- png_bytep offset_table;
- png_uint_16 offset_table_number;
- png_uint_16 offset_table_count;
- png_uint_16 offset_table_count_free;
-#endif
-
-#ifdef PNG_READ_QUANTIZE_SUPPORTED
- png_bytep palette_lookup; /* lookup table for quantizing */
- png_bytep quantize_index; /* index translation for palette files */
-#endif
-
-#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
- png_byte heuristic_method; /* heuristic for row filter selection */
- png_byte num_prev_filters; /* number of weights for previous rows */
- png_bytep prev_filters; /* filter type(s) of previous row(s) */
- png_uint_16p filter_weights; /* weight(s) for previous line(s) */
- png_uint_16p inv_filter_weights; /* 1/weight(s) for previous line(s) */
- png_uint_16p filter_costs; /* relative filter calculation cost */
- png_uint_16p inv_filter_costs; /* 1/relative filter calculation cost */
-#endif
-
- /* Options */
-#ifdef PNG_SET_OPTION_SUPPORTED
- png_byte options; /* On/off state (up to 4 options) */
-#endif
-
-#if PNG_LIBPNG_VER < 10700
-/* To do: remove this from libpng-1.7 */
-#ifdef PNG_TIME_RFC1123_SUPPORTED
- char time_buffer[29]; /* String to hold RFC 1123 time text */
-#endif
-#endif
-
-/* New members added in libpng-1.0.6 */
-
- png_uint_32 free_me; /* flags items libpng is responsible for freeing */
-
-#ifdef PNG_USER_CHUNKS_SUPPORTED
- png_voidp user_chunk_ptr;
-#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
- png_user_chunk_ptr read_user_chunk_fn; /* user read chunk handler */
-#endif
-#endif
-
-#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
- int unknown_default; /* As PNG_HANDLE_* */
- unsigned int num_chunk_list; /* Number of entries in the list */
- png_bytep chunk_list; /* List of png_byte[5]; the textual chunk name
- * followed by a PNG_HANDLE_* byte */
-#endif
-
-/* New members added in libpng-1.0.3 */
-#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
- png_byte rgb_to_gray_status;
- /* Added in libpng 1.5.5 to record setting of coefficients: */
- png_byte rgb_to_gray_coefficients_set;
- /* These were changed from png_byte in libpng-1.0.6 */
- png_uint_16 rgb_to_gray_red_coeff;
- png_uint_16 rgb_to_gray_green_coeff;
- /* deleted in 1.5.5: rgb_to_gray_blue_coeff; */
-#endif
-
-/* New member added in libpng-1.0.4 (renamed in 1.0.9) */
-#if defined(PNG_MNG_FEATURES_SUPPORTED)
-/* Changed from png_byte to png_uint_32 at version 1.2.0 */
- png_uint_32 mng_features_permitted;
-#endif
-
-/* New member added in libpng-1.0.9, ifdef'ed out in 1.0.12, enabled in 1.2.0 */
-#ifdef PNG_MNG_FEATURES_SUPPORTED
- png_byte filter_type;
-#endif
-
-/* New members added in libpng-1.2.0 */
-
-/* New members added in libpng-1.0.2 but first enabled by default in 1.2.0 */
-#ifdef PNG_USER_MEM_SUPPORTED
- png_voidp mem_ptr; /* user supplied struct for mem functions */
- png_malloc_ptr malloc_fn; /* function for allocating memory */
- png_free_ptr free_fn; /* function for freeing memory */
-#endif
-
-/* New member added in libpng-1.0.13 and 1.2.0 */
- png_bytep big_row_buf; /* buffer to save current (unfiltered) row */
-
-#ifdef PNG_READ_QUANTIZE_SUPPORTED
-/* The following three members were added at version 1.0.14 and 1.2.4 */
- png_bytep quantize_sort; /* working sort array */
- png_bytep index_to_palette; /* where the original index currently is
- in the palette */
- png_bytep palette_to_index; /* which original index points to this
- palette color */
-#endif
-
-/* New members added in libpng-1.0.16 and 1.2.6 */
- png_byte compression_type;
-
-#ifdef PNG_USER_LIMITS_SUPPORTED
- png_uint_32 user_width_max;
- png_uint_32 user_height_max;
-
- /* Added in libpng-1.4.0: Total number of sPLT, text, and unknown
- * chunks that can be stored (0 means unlimited).
- */
- png_uint_32 user_chunk_cache_max;
-
- /* Total memory that a zTXt, sPLT, iTXt, iCCP, or unknown chunk
- * can occupy when decompressed. 0 means unlimited.
- */
- png_alloc_size_t user_chunk_malloc_max;
-#endif
-
-/* New member added in libpng-1.0.25 and 1.2.17 */
-#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
- /* Temporary storage for unknown chunk that the library doesn't recognize,
- * used while reading the chunk.
- */
- png_unknown_chunk unknown_chunk;
-#endif
-
-/* New member added in libpng-1.2.26 */
- png_size_t old_big_row_buf_size;
-
-#ifdef PNG_READ_SUPPORTED
-/* New member added in libpng-1.2.30 */
- png_bytep read_buffer; /* buffer for reading chunk data */
- png_alloc_size_t read_buffer_size; /* current size of the buffer */
-#endif
-#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
- uInt IDAT_read_size; /* limit on read buffer size for IDAT */
-#endif
-
-#ifdef PNG_IO_STATE_SUPPORTED
-/* New member added in libpng-1.4.0 */
- png_uint_32 io_state;
-#endif
-
-/* New member added in libpng-1.5.6 */
- png_bytep big_prev_row;
-
-/* New member added in libpng-1.5.7 */
- void (*read_filter[PNG_FILTER_VALUE_LAST-1])(png_row_infop row_info,
- png_bytep row, png_const_bytep prev_row);
-
-#ifdef PNG_READ_SUPPORTED
-#if defined(PNG_COLORSPACE_SUPPORTED) || defined(PNG_GAMMA_SUPPORTED)
- png_colorspace colorspace;
-#endif
-#endif
-};
-#endif /* PNGSTRUCT_H */
+
+/* pngstruct.h - header file for PNG reference library
+ *
+ * Last changed in libpng 1.6.18 [July 23, 2015]
+ * Copyright (c) 1998-2015 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+
+/* The structure that holds the information to read and write PNG files.
+ * The only people who need to care about what is inside of this are the
+ * people who will be modifying the library for their own special needs.
+ * It should NOT be accessed directly by an application.
+ */
+
+#ifndef PNGSTRUCT_H
+#define PNGSTRUCT_H
+/* zlib.h defines the structure z_stream, an instance of which is included
+ * in this structure and is required for decompressing the LZ compressed
+ * data in PNG files.
+ */
+#ifndef ZLIB_CONST
+ /* We must ensure that zlib uses 'const' in declarations. */
+# define ZLIB_CONST
+#endif
+#include "third_party/zlib_v128/zlib.h"
+#ifdef const
+ /* zlib.h sometimes #defines const to nothing, undo this. */
+# undef const
+#endif
+
+/* zlib.h has mediocre z_const use before 1.2.6, this stuff is for compatibility
+ * with older builds.
+ */
+#if ZLIB_VERNUM < 0x1260
+# define PNGZ_MSG_CAST(s) png_constcast(char*,s)
+# define PNGZ_INPUT_CAST(b) png_constcast(png_bytep,b)
+#else
+# define PNGZ_MSG_CAST(s) (s)
+# define PNGZ_INPUT_CAST(b) (b)
+#endif
+
+/* zlib.h declares a magic type 'uInt' that limits the amount of data that zlib
+ * can handle at once. This type need be no larger than 16 bits (so maximum of
+ * 65535), this define allows us to discover how big it is, but limited by the
+ * maximuum for png_size_t. The value can be overriden in a library build
+ * (pngusr.h, or set it in CPPFLAGS) and it works to set it to a considerably
+ * lower value (e.g. 255 works). A lower value may help memory usage (slightly)
+ * and may even improve performance on some systems (and degrade it on others.)
+ */
+#ifndef ZLIB_IO_MAX
+# define ZLIB_IO_MAX ((uInt)-1)
+#endif
+
+#ifdef PNG_WRITE_SUPPORTED
+/* The type of a compression buffer list used by the write code. */
+typedef struct png_compression_buffer
+{
+ struct png_compression_buffer *next;
+ png_byte output[1]; /* actually zbuf_size */
+} png_compression_buffer, *png_compression_bufferp;
+
+#define PNG_COMPRESSION_BUFFER_SIZE(pp)\
+ (offsetof(png_compression_buffer, output) + (pp)->zbuffer_size)
+#endif
+
+/* Colorspace support; structures used in png_struct, png_info and in internal
+ * functions to hold and communicate information about the color space.
+ *
+ * PNG_COLORSPACE_SUPPORTED is only required if the application will perform
+ * colorspace corrections, otherwise all the colorspace information can be
+ * skipped and the size of libpng can be reduced (significantly) by compiling
+ * out the colorspace support.
+ */
+#ifdef PNG_COLORSPACE_SUPPORTED
+/* The chromaticities of the red, green and blue colorants and the chromaticity
+ * of the corresponding white point (i.e. of rgb(1.0,1.0,1.0)).
+ */
+typedef struct png_xy
+{
+ png_fixed_point redx, redy;
+ png_fixed_point greenx, greeny;
+ png_fixed_point bluex, bluey;
+ png_fixed_point whitex, whitey;
+} png_xy;
+
+/* The same data as above but encoded as CIE XYZ values. When this data comes
+ * from chromaticities the sum of the Y values is assumed to be 1.0
+ */
+typedef struct png_XYZ
+{
+ png_fixed_point red_X, red_Y, red_Z;
+ png_fixed_point green_X, green_Y, green_Z;
+ png_fixed_point blue_X, blue_Y, blue_Z;
+} png_XYZ;
+#endif /* COLORSPACE */
+
+#if defined(PNG_COLORSPACE_SUPPORTED) || defined(PNG_GAMMA_SUPPORTED)
+/* A colorspace is all the above plus, potentially, profile information;
+ * however at present libpng does not use the profile internally so it is only
+ * stored in the png_info struct (if iCCP is supported.) The rendering intent
+ * is retained here and is checked.
+ *
+ * The file gamma encoding information is also stored here and gamma correction
+ * is done by libpng, whereas color correction must currently be done by the
+ * application.
+ */
+typedef struct png_colorspace
+{
+#ifdef PNG_GAMMA_SUPPORTED
+ png_fixed_point gamma; /* File gamma */
+#endif
+
+#ifdef PNG_COLORSPACE_SUPPORTED
+ png_xy end_points_xy; /* End points as chromaticities */
+ png_XYZ end_points_XYZ; /* End points as CIE XYZ colorant values */
+ png_uint_16 rendering_intent; /* Rendering intent of a profile */
+#endif
+
+ /* Flags are always defined to simplify the code. */
+ png_uint_16 flags; /* As defined below */
+} png_colorspace, * PNG_RESTRICT png_colorspacerp;
+
+typedef const png_colorspace * PNG_RESTRICT png_const_colorspacerp;
+
+/* General flags for the 'flags' field */
+#define PNG_COLORSPACE_HAVE_GAMMA 0x0001
+#define PNG_COLORSPACE_HAVE_ENDPOINTS 0x0002
+#define PNG_COLORSPACE_HAVE_INTENT 0x0004
+#define PNG_COLORSPACE_FROM_gAMA 0x0008
+#define PNG_COLORSPACE_FROM_cHRM 0x0010
+#define PNG_COLORSPACE_FROM_sRGB 0x0020
+#define PNG_COLORSPACE_ENDPOINTS_MATCH_sRGB 0x0040
+#define PNG_COLORSPACE_MATCHES_sRGB 0x0080 /* exact match on profile */
+#define PNG_COLORSPACE_INVALID 0x8000
+#define PNG_COLORSPACE_CANCEL(flags) (0xffff ^ (flags))
+#endif /* COLORSPACE || GAMMA */
+
+struct png_struct_def
+{
+#ifdef PNG_SETJMP_SUPPORTED
+ jmp_buf jmp_buf_local; /* New name in 1.6.0 for jmp_buf in png_struct */
+ png_longjmp_ptr longjmp_fn;/* setjmp non-local goto function. */
+ jmp_buf *jmp_buf_ptr; /* passed to longjmp_fn */
+ size_t jmp_buf_size; /* size of the above, if allocated */
+#endif
+ png_error_ptr error_fn; /* function for printing errors and aborting */
+#ifdef PNG_WARNINGS_SUPPORTED
+ png_error_ptr warning_fn; /* function for printing warnings */
+#endif
+ png_voidp error_ptr; /* user supplied struct for error functions */
+ png_rw_ptr write_data_fn; /* function for writing output data */
+ png_rw_ptr read_data_fn; /* function for reading input data */
+ png_voidp io_ptr; /* ptr to application struct for I/O functions */
+
+#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
+ png_user_transform_ptr read_user_transform_fn; /* user read transform */
+#endif
+
+#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
+ png_user_transform_ptr write_user_transform_fn; /* user write transform */
+#endif
+
+/* These were added in libpng-1.0.2 */
+#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
+#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
+ defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
+ png_voidp user_transform_ptr; /* user supplied struct for user transform */
+ png_byte user_transform_depth; /* bit depth of user transformed pixels */
+ png_byte user_transform_channels; /* channels in user transformed pixels */
+#endif
+#endif
+
+ png_uint_32 mode; /* tells us where we are in the PNG file */
+ png_uint_32 flags; /* flags indicating various things to libpng */
+ png_uint_32 transformations; /* which transformations to perform */
+
+ png_uint_32 zowner; /* ID (chunk type) of zstream owner, 0 if none */
+ z_stream zstream; /* decompression structure */
+
+#ifdef PNG_WRITE_SUPPORTED
+ png_compression_bufferp zbuffer_list; /* Created on demand during write */
+ uInt zbuffer_size; /* size of the actual buffer */
+
+ int zlib_level; /* holds zlib compression level */
+ int zlib_method; /* holds zlib compression method */
+ int zlib_window_bits; /* holds zlib compression window bits */
+ int zlib_mem_level; /* holds zlib compression memory level */
+ int zlib_strategy; /* holds zlib compression strategy */
+#endif
+/* Added at libpng 1.5.4 */
+#ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
+ int zlib_text_level; /* holds zlib compression level */
+ int zlib_text_method; /* holds zlib compression method */
+ int zlib_text_window_bits; /* holds zlib compression window bits */
+ int zlib_text_mem_level; /* holds zlib compression memory level */
+ int zlib_text_strategy; /* holds zlib compression strategy */
+#endif
+/* End of material added at libpng 1.5.4 */
+/* Added at libpng 1.6.0 */
+#ifdef PNG_WRITE_SUPPORTED
+ int zlib_set_level; /* Actual values set into the zstream on write */
+ int zlib_set_method;
+ int zlib_set_window_bits;
+ int zlib_set_mem_level;
+ int zlib_set_strategy;
+#endif
+
+ png_uint_32 width; /* width of image in pixels */
+ png_uint_32 height; /* height of image in pixels */
+ png_uint_32 num_rows; /* number of rows in current pass */
+ png_uint_32 usr_width; /* width of row at start of write */
+ png_size_t rowbytes; /* size of row in bytes */
+ png_uint_32 iwidth; /* width of current interlaced row in pixels */
+ png_uint_32 row_number; /* current row in interlace pass */
+ png_uint_32 chunk_name; /* PNG_CHUNK() id of current chunk */
+ png_bytep prev_row; /* buffer to save previous (unfiltered) row.
+ * While reading this is a pointer into
+ * big_prev_row; while writing it is separately
+ * allocated if needed.
+ */
+ png_bytep row_buf; /* buffer to save current (unfiltered) row.
+ * While reading, this is a pointer into
+ * big_row_buf; while writing it is separately
+ * allocated.
+ */
+#ifdef PNG_WRITE_FILTER_SUPPORTED
+ png_bytep try_row; /* buffer to save trial row when filtering */
+ png_bytep tst_row; /* buffer to save best trial row when filtering */
+#endif
+ png_size_t info_rowbytes; /* Added in 1.5.4: cache of updated row bytes */
+
+ png_uint_32 idat_size; /* current IDAT size for read */
+ png_uint_32 crc; /* current chunk CRC value */
+ png_colorp palette; /* palette from the input file */
+ png_uint_16 num_palette; /* number of color entries in palette */
+
+/* Added at libpng-1.5.10 */
+#ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED
+ int num_palette_max; /* maximum palette index found in IDAT */
+#endif
+
+ png_uint_16 num_trans; /* number of transparency values */
+ png_byte compression; /* file compression type (always 0) */
+ png_byte filter; /* file filter type (always 0) */
+ png_byte interlaced; /* PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */
+ png_byte pass; /* current interlace pass (0 - 6) */
+ png_byte do_filter; /* row filter flags (see PNG_FILTER_ below ) */
+ png_byte color_type; /* color type of file */
+ png_byte bit_depth; /* bit depth of file */
+ png_byte usr_bit_depth; /* bit depth of users row: write only */
+ png_byte pixel_depth; /* number of bits per pixel */
+ png_byte channels; /* number of channels in file */
+#ifdef PNG_WRITE_SUPPORTED
+ png_byte usr_channels; /* channels at start of write: write only */
+#endif
+ png_byte sig_bytes; /* magic bytes read/written from start of file */
+ png_byte maximum_pixel_depth;
+ /* pixel depth used for the row buffers */
+ png_byte transformed_pixel_depth;
+ /* pixel depth after read/write transforms */
+#if PNG_ZLIB_VERNUM >= 0x1240
+ png_byte zstream_start; /* at start of an input zlib stream */
+#endif /* Zlib >= 1.2.4 */
+#if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
+ png_uint_16 filler; /* filler bytes for pixel expansion */
+#endif
+
+#if defined(PNG_bKGD_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) ||\
+ defined(PNG_READ_ALPHA_MODE_SUPPORTED)
+ png_byte background_gamma_type;
+ png_fixed_point background_gamma;
+ png_color_16 background; /* background color in screen gamma space */
+#ifdef PNG_READ_GAMMA_SUPPORTED
+ png_color_16 background_1; /* background normalized to gamma 1.0 */
+#endif
+#endif /* bKGD */
+
+#ifdef PNG_WRITE_FLUSH_SUPPORTED
+ png_flush_ptr output_flush_fn; /* Function for flushing output */
+ png_uint_32 flush_dist; /* how many rows apart to flush, 0 - no flush */
+ png_uint_32 flush_rows; /* number of rows written since last flush */
+#endif
+
+#ifdef PNG_READ_GAMMA_SUPPORTED
+ int gamma_shift; /* number of "insignificant" bits in 16-bit gamma */
+ png_fixed_point screen_gamma; /* screen gamma value (display_exponent) */
+
+ png_bytep gamma_table; /* gamma table for 8-bit depth files */
+ png_uint_16pp gamma_16_table; /* gamma table for 16-bit depth files */
+#if defined(PNG_READ_BACKGROUND_SUPPORTED) || \
+ defined(PNG_READ_ALPHA_MODE_SUPPORTED) || \
+ defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
+ png_bytep gamma_from_1; /* converts from 1.0 to screen */
+ png_bytep gamma_to_1; /* converts from file to 1.0 */
+ png_uint_16pp gamma_16_from_1; /* converts from 1.0 to screen */
+ png_uint_16pp gamma_16_to_1; /* converts from file to 1.0 */
+#endif /* READ_BACKGROUND || READ_ALPHA_MODE || RGB_TO_GRAY */
+#endif
+
+#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_sBIT_SUPPORTED)
+ png_color_8 sig_bit; /* significant bits in each available channel */
+#endif
+
+#if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
+ png_color_8 shift; /* shift for significant bit tranformation */
+#endif
+
+#if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) \
+ || defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
+ png_bytep trans_alpha; /* alpha values for paletted files */
+ png_color_16 trans_color; /* transparent color for non-paletted files */
+#endif
+
+ png_read_status_ptr read_row_fn; /* called after each row is decoded */
+ png_write_status_ptr write_row_fn; /* called after each row is encoded */
+#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
+ png_progressive_info_ptr info_fn; /* called after header data fully read */
+ png_progressive_row_ptr row_fn; /* called after a prog. row is decoded */
+ png_progressive_end_ptr end_fn; /* called after image is complete */
+ png_bytep save_buffer_ptr; /* current location in save_buffer */
+ png_bytep save_buffer; /* buffer for previously read data */
+ png_bytep current_buffer_ptr; /* current location in current_buffer */
+ png_bytep current_buffer; /* buffer for recently used data */
+ png_uint_32 push_length; /* size of current input chunk */
+ png_uint_32 skip_length; /* bytes to skip in input data */
+ png_size_t save_buffer_size; /* amount of data now in save_buffer */
+ png_size_t save_buffer_max; /* total size of save_buffer */
+ png_size_t buffer_size; /* total amount of available input data */
+ png_size_t current_buffer_size; /* amount of data now in current_buffer */
+ int process_mode; /* what push library is currently doing */
+ int cur_palette; /* current push library palette index */
+
+#endif /* PROGRESSIVE_READ */
+
+#if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__)
+/* For the Borland special 64K segment handler */
+ png_bytepp offset_table_ptr;
+ png_bytep offset_table;
+ png_uint_16 offset_table_number;
+ png_uint_16 offset_table_count;
+ png_uint_16 offset_table_count_free;
+#endif
+
+#ifdef PNG_READ_QUANTIZE_SUPPORTED
+ png_bytep palette_lookup; /* lookup table for quantizing */
+ png_bytep quantize_index; /* index translation for palette files */
+#endif
+
+/* Options */
+#ifdef PNG_SET_OPTION_SUPPORTED
+ png_byte options; /* On/off state (up to 4 options) */
+#endif
+
+#if PNG_LIBPNG_VER < 10700
+/* To do: remove this from libpng-1.7 */
+#ifdef PNG_TIME_RFC1123_SUPPORTED
+ char time_buffer[29]; /* String to hold RFC 1123 time text */
+#endif
+#endif
+
+/* New members added in libpng-1.0.6 */
+
+ png_uint_32 free_me; /* flags items libpng is responsible for freeing */
+
+#ifdef PNG_USER_CHUNKS_SUPPORTED
+ png_voidp user_chunk_ptr;
+#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
+ png_user_chunk_ptr read_user_chunk_fn; /* user read chunk handler */
+#endif
+#endif
+
+#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
+ int unknown_default; /* As PNG_HANDLE_* */
+ unsigned int num_chunk_list; /* Number of entries in the list */
+ png_bytep chunk_list; /* List of png_byte[5]; the textual chunk name
+ * followed by a PNG_HANDLE_* byte */
+#endif
+
+/* New members added in libpng-1.0.3 */
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+ png_byte rgb_to_gray_status;
+ /* Added in libpng 1.5.5 to record setting of coefficients: */
+ png_byte rgb_to_gray_coefficients_set;
+ /* These were changed from png_byte in libpng-1.0.6 */
+ png_uint_16 rgb_to_gray_red_coeff;
+ png_uint_16 rgb_to_gray_green_coeff;
+ /* deleted in 1.5.5: rgb_to_gray_blue_coeff; */
+#endif
+
+/* New member added in libpng-1.0.4 (renamed in 1.0.9) */
+#if defined(PNG_MNG_FEATURES_SUPPORTED)
+/* Changed from png_byte to png_uint_32 at version 1.2.0 */
+ png_uint_32 mng_features_permitted;
+#endif
+
+/* New member added in libpng-1.0.9, ifdef'ed out in 1.0.12, enabled in 1.2.0 */
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+ png_byte filter_type;
+#endif
+
+/* New members added in libpng-1.2.0 */
+
+/* New members added in libpng-1.0.2 but first enabled by default in 1.2.0 */
+#ifdef PNG_USER_MEM_SUPPORTED
+ png_voidp mem_ptr; /* user supplied struct for mem functions */
+ png_malloc_ptr malloc_fn; /* function for allocating memory */
+ png_free_ptr free_fn; /* function for freeing memory */
+#endif
+
+/* New member added in libpng-1.0.13 and 1.2.0 */
+ png_bytep big_row_buf; /* buffer to save current (unfiltered) row */
+
+#ifdef PNG_READ_QUANTIZE_SUPPORTED
+/* The following three members were added at version 1.0.14 and 1.2.4 */
+ png_bytep quantize_sort; /* working sort array */
+ png_bytep index_to_palette; /* where the original index currently is
+ in the palette */
+ png_bytep palette_to_index; /* which original index points to this
+ palette color */
+#endif
+
+/* New members added in libpng-1.0.16 and 1.2.6 */
+ png_byte compression_type;
+
+#ifdef PNG_USER_LIMITS_SUPPORTED
+ png_uint_32 user_width_max;
+ png_uint_32 user_height_max;
+
+ /* Added in libpng-1.4.0: Total number of sPLT, text, and unknown
+ * chunks that can be stored (0 means unlimited).
+ */
+ png_uint_32 user_chunk_cache_max;
+
+ /* Total memory that a zTXt, sPLT, iTXt, iCCP, or unknown chunk
+ * can occupy when decompressed. 0 means unlimited.
+ */
+ png_alloc_size_t user_chunk_malloc_max;
+#endif
+
+/* New member added in libpng-1.0.25 and 1.2.17 */
+#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
+ /* Temporary storage for unknown chunk that the library doesn't recognize,
+ * used while reading the chunk.
+ */
+ png_unknown_chunk unknown_chunk;
+#endif
+
+/* New member added in libpng-1.2.26 */
+ png_size_t old_big_row_buf_size;
+
+#ifdef PNG_READ_SUPPORTED
+/* New member added in libpng-1.2.30 */
+ png_bytep read_buffer; /* buffer for reading chunk data */
+ png_alloc_size_t read_buffer_size; /* current size of the buffer */
+#endif
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+ uInt IDAT_read_size; /* limit on read buffer size for IDAT */
+#endif
+
+#ifdef PNG_IO_STATE_SUPPORTED
+/* New member added in libpng-1.4.0 */
+ png_uint_32 io_state;
+#endif
+
+/* New member added in libpng-1.5.6 */
+ png_bytep big_prev_row;
+
+/* New member added in libpng-1.5.7 */
+ void (*read_filter[PNG_FILTER_VALUE_LAST-1])(png_row_infop row_info,
+ png_bytep row, png_const_bytep prev_row);
+
+#ifdef PNG_READ_SUPPORTED
+#if defined(PNG_COLORSPACE_SUPPORTED) || defined(PNG_GAMMA_SUPPORTED)
+ png_colorspace colorspace;
+#endif
+#endif
+};
+#endif /* PNGSTRUCT_H */
diff --git a/third_party/lpng_v163/pngtrans.c b/third_party/libpng/pngtrans.c
similarity index 94%
rename from third_party/lpng_v163/pngtrans.c
rename to third_party/libpng/pngtrans.c
index 0de6a46..0c0d92d 100644
--- a/third_party/lpng_v163/pngtrans.c
+++ b/third_party/libpng/pngtrans.c
@@ -1,840 +1,849 @@
-/* pngtrans.c - transforms the data in a row (used by both readers and writers)
- *
- * Last changed in libpng 1.6.2 [April 25, 2013]
- * Copyright (c) 1998-2013 Glenn Randers-Pehrson
- * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
- * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
- *
- * This code is released under the libpng license.
- * For conditions of distribution and use, see the disclaimer
- * and license in png.h
- */
-
-#include "pngpriv.h"
-
-#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
-
-#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
-/* Turn on BGR-to-RGB mapping */
-void PNGAPI
-png_set_bgr(png_structrp png_ptr)
-{
- png_debug(1, "in png_set_bgr");
-
- if (png_ptr == NULL)
- return;
-
- png_ptr->transformations |= PNG_BGR;
-}
-#endif
-
-#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
-/* Turn on 16 bit byte swapping */
-void PNGAPI
-png_set_swap(png_structrp png_ptr)
-{
- png_debug(1, "in png_set_swap");
-
- if (png_ptr == NULL)
- return;
-
- if (png_ptr->bit_depth == 16)
- png_ptr->transformations |= PNG_SWAP_BYTES;
-}
-#endif
-
-#if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
-/* Turn on pixel packing */
-void PNGAPI
-png_set_packing(png_structrp png_ptr)
-{
- png_debug(1, "in png_set_packing");
-
- if (png_ptr == NULL)
- return;
-
- if (png_ptr->bit_depth < 8)
- {
- png_ptr->transformations |= PNG_PACK;
- png_ptr->usr_bit_depth = 8;
- }
-}
-#endif
-
-#if defined(PNG_READ_PACKSWAP_SUPPORTED)||defined(PNG_WRITE_PACKSWAP_SUPPORTED)
-/* Turn on packed pixel swapping */
-void PNGAPI
-png_set_packswap(png_structrp png_ptr)
-{
- png_debug(1, "in png_set_packswap");
-
- if (png_ptr == NULL)
- return;
-
- if (png_ptr->bit_depth < 8)
- png_ptr->transformations |= PNG_PACKSWAP;
-}
-#endif
-
-#if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
-void PNGAPI
-png_set_shift(png_structrp png_ptr, png_const_color_8p true_bits)
-{
- png_debug(1, "in png_set_shift");
-
- if (png_ptr == NULL)
- return;
-
- png_ptr->transformations |= PNG_SHIFT;
- png_ptr->shift = *true_bits;
-}
-#endif
-
-#if defined(PNG_READ_INTERLACING_SUPPORTED) || \
- defined(PNG_WRITE_INTERLACING_SUPPORTED)
-int PNGAPI
-png_set_interlace_handling(png_structrp png_ptr)
-{
- png_debug(1, "in png_set_interlace handling");
-
- if (png_ptr && png_ptr->interlaced)
- {
- png_ptr->transformations |= PNG_INTERLACE;
- return (7);
- }
-
- return (1);
-}
-#endif
-
-#if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
-/* Add a filler byte on read, or remove a filler or alpha byte on write.
- * The filler type has changed in v0.95 to allow future 2-byte fillers
- * for 48-bit input data, as well as to avoid problems with some compilers
- * that don't like bytes as parameters.
- */
-void PNGAPI
-png_set_filler(png_structrp png_ptr, png_uint_32 filler, int filler_loc)
-{
- png_debug(1, "in png_set_filler");
-
- if (png_ptr == NULL)
- return;
-
- /* In libpng 1.6 it is possible to determine whether this is a read or write
- * operation and therefore to do more checking here for a valid call.
- */
- if (png_ptr->mode & PNG_IS_READ_STRUCT)
- {
-# ifdef PNG_READ_FILLER_SUPPORTED
- /* On read png_set_filler is always valid, regardless of the base PNG
- * format, because other transformations can give a format where the
- * filler code can execute (basically an 8 or 16-bit component RGB or G
- * format.)
- *
- * NOTE: usr_channels is not used by the read code! (This has led to
- * confusion in the past.) The filler is only used in the read code.
- */
- png_ptr->filler = (png_uint_16)filler;
-# else
- png_app_error(png_ptr, "png_set_filler not supported on read");
- PNG_UNUSED(filler) /* not used in the write case */
- return;
-# endif
- }
-
- else /* write */
- {
-# ifdef PNG_WRITE_FILLER_SUPPORTED
- /* On write the usr_channels parameter must be set correctly at the
- * start to record the number of channels in the app-supplied data.
- */
- switch (png_ptr->color_type)
- {
- case PNG_COLOR_TYPE_RGB:
- png_ptr->usr_channels = 4;
- break;
-
- case PNG_COLOR_TYPE_GRAY:
- if (png_ptr->bit_depth >= 8)
- {
- png_ptr->usr_channels = 2;
- break;
- }
-
- else
- {
- /* There simply isn't any code in libpng to strip out bits
- * from bytes when the components are less than a byte in
- * size!
- */
- png_app_error(png_ptr,
- "png_set_filler is invalid for low bit depth gray output");
- return;
- }
-
- default:
- png_app_error(png_ptr,
- "png_set_filler: inappropriate color type");
- return;
- }
-# else
- png_app_error(png_ptr, "png_set_filler not supported on write");
- return;
-# endif
- }
-
- /* Here on success - libpng supports the operation, set the transformation
- * and the flag to say where the filler channel is.
- */
- png_ptr->transformations |= PNG_FILLER;
-
- if (filler_loc == PNG_FILLER_AFTER)
- png_ptr->flags |= PNG_FLAG_FILLER_AFTER;
-
- else
- png_ptr->flags &= ~PNG_FLAG_FILLER_AFTER;
-}
-
-/* Added to libpng-1.2.7 */
-void PNGAPI
-png_set_add_alpha(png_structrp png_ptr, png_uint_32 filler, int filler_loc)
-{
- png_debug(1, "in png_set_add_alpha");
-
- if (png_ptr == NULL)
- return;
-
- png_set_filler(png_ptr, filler, filler_loc);
- /* The above may fail to do anything. */
- if (png_ptr->transformations & PNG_FILLER)
- png_ptr->transformations |= PNG_ADD_ALPHA;
-}
-
-#endif
-
-#if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \
- defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
-void PNGAPI
-png_set_swap_alpha(png_structrp png_ptr)
-{
- png_debug(1, "in png_set_swap_alpha");
-
- if (png_ptr == NULL)
- return;
-
- png_ptr->transformations |= PNG_SWAP_ALPHA;
-}
-#endif
-
-#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \
- defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
-void PNGAPI
-png_set_invert_alpha(png_structrp png_ptr)
-{
- png_debug(1, "in png_set_invert_alpha");
-
- if (png_ptr == NULL)
- return;
-
- png_ptr->transformations |= PNG_INVERT_ALPHA;
-}
-#endif
-
-#if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
-void PNGAPI
-png_set_invert_mono(png_structrp png_ptr)
-{
- png_debug(1, "in png_set_invert_mono");
-
- if (png_ptr == NULL)
- return;
-
- png_ptr->transformations |= PNG_INVERT_MONO;
-}
-
-/* Invert monochrome grayscale data */
-void /* PRIVATE */
-png_do_invert(png_row_infop row_info, png_bytep row)
-{
- png_debug(1, "in png_do_invert");
-
- /* This test removed from libpng version 1.0.13 and 1.2.0:
- * if (row_info->bit_depth == 1 &&
- */
- if (row_info->color_type == PNG_COLOR_TYPE_GRAY)
- {
- png_bytep rp = row;
- png_size_t i;
- png_size_t istop = row_info->rowbytes;
-
- for (i = 0; i < istop; i++)
- {
- *rp = (png_byte)(~(*rp));
- rp++;
- }
- }
-
- else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA &&
- row_info->bit_depth == 8)
- {
- png_bytep rp = row;
- png_size_t i;
- png_size_t istop = row_info->rowbytes;
-
- for (i = 0; i < istop; i += 2)
- {
- *rp = (png_byte)(~(*rp));
- rp += 2;
- }
- }
-
-#ifdef PNG_16BIT_SUPPORTED
- else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA &&
- row_info->bit_depth == 16)
- {
- png_bytep rp = row;
- png_size_t i;
- png_size_t istop = row_info->rowbytes;
-
- for (i = 0; i < istop; i += 4)
- {
- *rp = (png_byte)(~(*rp));
- *(rp + 1) = (png_byte)(~(*(rp + 1)));
- rp += 4;
- }
- }
-#endif
-}
-#endif
-
-#ifdef PNG_16BIT_SUPPORTED
-#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
-/* Swaps byte order on 16 bit depth images */
-void /* PRIVATE */
-png_do_swap(png_row_infop row_info, png_bytep row)
-{
- png_debug(1, "in png_do_swap");
-
- if (row_info->bit_depth == 16)
- {
- png_bytep rp = row;
- png_uint_32 i;
- png_uint_32 istop= row_info->width * row_info->channels;
-
- for (i = 0; i < istop; i++, rp += 2)
- {
- png_byte t = *rp;
- *rp = *(rp + 1);
- *(rp + 1) = t;
- }
- }
-}
-#endif
-#endif
-
-#if defined(PNG_READ_PACKSWAP_SUPPORTED)||defined(PNG_WRITE_PACKSWAP_SUPPORTED)
-static PNG_CONST png_byte onebppswaptable[256] = {
- 0x00, 0x80, 0x40, 0xC0, 0x20, 0xA0, 0x60, 0xE0,
- 0x10, 0x90, 0x50, 0xD0, 0x30, 0xB0, 0x70, 0xF0,
- 0x08, 0x88, 0x48, 0xC8, 0x28, 0xA8, 0x68, 0xE8,
- 0x18, 0x98, 0x58, 0xD8, 0x38, 0xB8, 0x78, 0xF8,
- 0x04, 0x84, 0x44, 0xC4, 0x24, 0xA4, 0x64, 0xE4,
- 0x14, 0x94, 0x54, 0xD4, 0x34, 0xB4, 0x74, 0xF4,
- 0x0C, 0x8C, 0x4C, 0xCC, 0x2C, 0xAC, 0x6C, 0xEC,
- 0x1C, 0x9C, 0x5C, 0xDC, 0x3C, 0xBC, 0x7C, 0xFC,
- 0x02, 0x82, 0x42, 0xC2, 0x22, 0xA2, 0x62, 0xE2,
- 0x12, 0x92, 0x52, 0xD2, 0x32, 0xB2, 0x72, 0xF2,
- 0x0A, 0x8A, 0x4A, 0xCA, 0x2A, 0xAA, 0x6A, 0xEA,
- 0x1A, 0x9A, 0x5A, 0xDA, 0x3A, 0xBA, 0x7A, 0xFA,
- 0x06, 0x86, 0x46, 0xC6, 0x26, 0xA6, 0x66, 0xE6,
- 0x16, 0x96, 0x56, 0xD6, 0x36, 0xB6, 0x76, 0xF6,
- 0x0E, 0x8E, 0x4E, 0xCE, 0x2E, 0xAE, 0x6E, 0xEE,
- 0x1E, 0x9E, 0x5E, 0xDE, 0x3E, 0xBE, 0x7E, 0xFE,
- 0x01, 0x81, 0x41, 0xC1, 0x21, 0xA1, 0x61, 0xE1,
- 0x11, 0x91, 0x51, 0xD1, 0x31, 0xB1, 0x71, 0xF1,
- 0x09, 0x89, 0x49, 0xC9, 0x29, 0xA9, 0x69, 0xE9,
- 0x19, 0x99, 0x59, 0xD9, 0x39, 0xB9, 0x79, 0xF9,
- 0x05, 0x85, 0x45, 0xC5, 0x25, 0xA5, 0x65, 0xE5,
- 0x15, 0x95, 0x55, 0xD5, 0x35, 0xB5, 0x75, 0xF5,
- 0x0D, 0x8D, 0x4D, 0xCD, 0x2D, 0xAD, 0x6D, 0xED,
- 0x1D, 0x9D, 0x5D, 0xDD, 0x3D, 0xBD, 0x7D, 0xFD,
- 0x03, 0x83, 0x43, 0xC3, 0x23, 0xA3, 0x63, 0xE3,
- 0x13, 0x93, 0x53, 0xD3, 0x33, 0xB3, 0x73, 0xF3,
- 0x0B, 0x8B, 0x4B, 0xCB, 0x2B, 0xAB, 0x6B, 0xEB,
- 0x1B, 0x9B, 0x5B, 0xDB, 0x3B, 0xBB, 0x7B, 0xFB,
- 0x07, 0x87, 0x47, 0xC7, 0x27, 0xA7, 0x67, 0xE7,
- 0x17, 0x97, 0x57, 0xD7, 0x37, 0xB7, 0x77, 0xF7,
- 0x0F, 0x8F, 0x4F, 0xCF, 0x2F, 0xAF, 0x6F, 0xEF,
- 0x1F, 0x9F, 0x5F, 0xDF, 0x3F, 0xBF, 0x7F, 0xFF
-};
-
-static PNG_CONST png_byte twobppswaptable[256] = {
- 0x00, 0x40, 0x80, 0xC0, 0x10, 0x50, 0x90, 0xD0,
- 0x20, 0x60, 0xA0, 0xE0, 0x30, 0x70, 0xB0, 0xF0,
- 0x04, 0x44, 0x84, 0xC4, 0x14, 0x54, 0x94, 0xD4,
- 0x24, 0x64, 0xA4, 0xE4, 0x34, 0x74, 0xB4, 0xF4,
- 0x08, 0x48, 0x88, 0xC8, 0x18, 0x58, 0x98, 0xD8,
- 0x28, 0x68, 0xA8, 0xE8, 0x38, 0x78, 0xB8, 0xF8,
- 0x0C, 0x4C, 0x8C, 0xCC, 0x1C, 0x5C, 0x9C, 0xDC,
- 0x2C, 0x6C, 0xAC, 0xEC, 0x3C, 0x7C, 0xBC, 0xFC,
- 0x01, 0x41, 0x81, 0xC1, 0x11, 0x51, 0x91, 0xD1,
- 0x21, 0x61, 0xA1, 0xE1, 0x31, 0x71, 0xB1, 0xF1,
- 0x05, 0x45, 0x85, 0xC5, 0x15, 0x55, 0x95, 0xD5,
- 0x25, 0x65, 0xA5, 0xE5, 0x35, 0x75, 0xB5, 0xF5,
- 0x09, 0x49, 0x89, 0xC9, 0x19, 0x59, 0x99, 0xD9,
- 0x29, 0x69, 0xA9, 0xE9, 0x39, 0x79, 0xB9, 0xF9,
- 0x0D, 0x4D, 0x8D, 0xCD, 0x1D, 0x5D, 0x9D, 0xDD,
- 0x2D, 0x6D, 0xAD, 0xED, 0x3D, 0x7D, 0xBD, 0xFD,
- 0x02, 0x42, 0x82, 0xC2, 0x12, 0x52, 0x92, 0xD2,
- 0x22, 0x62, 0xA2, 0xE2, 0x32, 0x72, 0xB2, 0xF2,
- 0x06, 0x46, 0x86, 0xC6, 0x16, 0x56, 0x96, 0xD6,
- 0x26, 0x66, 0xA6, 0xE6, 0x36, 0x76, 0xB6, 0xF6,
- 0x0A, 0x4A, 0x8A, 0xCA, 0x1A, 0x5A, 0x9A, 0xDA,
- 0x2A, 0x6A, 0xAA, 0xEA, 0x3A, 0x7A, 0xBA, 0xFA,
- 0x0E, 0x4E, 0x8E, 0xCE, 0x1E, 0x5E, 0x9E, 0xDE,
- 0x2E, 0x6E, 0xAE, 0xEE, 0x3E, 0x7E, 0xBE, 0xFE,
- 0x03, 0x43, 0x83, 0xC3, 0x13, 0x53, 0x93, 0xD3,
- 0x23, 0x63, 0xA3, 0xE3, 0x33, 0x73, 0xB3, 0xF3,
- 0x07, 0x47, 0x87, 0xC7, 0x17, 0x57, 0x97, 0xD7,
- 0x27, 0x67, 0xA7, 0xE7, 0x37, 0x77, 0xB7, 0xF7,
- 0x0B, 0x4B, 0x8B, 0xCB, 0x1B, 0x5B, 0x9B, 0xDB,
- 0x2B, 0x6B, 0xAB, 0xEB, 0x3B, 0x7B, 0xBB, 0xFB,
- 0x0F, 0x4F, 0x8F, 0xCF, 0x1F, 0x5F, 0x9F, 0xDF,
- 0x2F, 0x6F, 0xAF, 0xEF, 0x3F, 0x7F, 0xBF, 0xFF
-};
-
-static PNG_CONST png_byte fourbppswaptable[256] = {
- 0x00, 0x10, 0x20, 0x30, 0x40, 0x50, 0x60, 0x70,
- 0x80, 0x90, 0xA0, 0xB0, 0xC0, 0xD0, 0xE0, 0xF0,
- 0x01, 0x11, 0x21, 0x31, 0x41, 0x51, 0x61, 0x71,
- 0x81, 0x91, 0xA1, 0xB1, 0xC1, 0xD1, 0xE1, 0xF1,
- 0x02, 0x12, 0x22, 0x32, 0x42, 0x52, 0x62, 0x72,
- 0x82, 0x92, 0xA2, 0xB2, 0xC2, 0xD2, 0xE2, 0xF2,
- 0x03, 0x13, 0x23, 0x33, 0x43, 0x53, 0x63, 0x73,
- 0x83, 0x93, 0xA3, 0xB3, 0xC3, 0xD3, 0xE3, 0xF3,
- 0x04, 0x14, 0x24, 0x34, 0x44, 0x54, 0x64, 0x74,
- 0x84, 0x94, 0xA4, 0xB4, 0xC4, 0xD4, 0xE4, 0xF4,
- 0x05, 0x15, 0x25, 0x35, 0x45, 0x55, 0x65, 0x75,
- 0x85, 0x95, 0xA5, 0xB5, 0xC5, 0xD5, 0xE5, 0xF5,
- 0x06, 0x16, 0x26, 0x36, 0x46, 0x56, 0x66, 0x76,
- 0x86, 0x96, 0xA6, 0xB6, 0xC6, 0xD6, 0xE6, 0xF6,
- 0x07, 0x17, 0x27, 0x37, 0x47, 0x57, 0x67, 0x77,
- 0x87, 0x97, 0xA7, 0xB7, 0xC7, 0xD7, 0xE7, 0xF7,
- 0x08, 0x18, 0x28, 0x38, 0x48, 0x58, 0x68, 0x78,
- 0x88, 0x98, 0xA8, 0xB8, 0xC8, 0xD8, 0xE8, 0xF8,
- 0x09, 0x19, 0x29, 0x39, 0x49, 0x59, 0x69, 0x79,
- 0x89, 0x99, 0xA9, 0xB9, 0xC9, 0xD9, 0xE9, 0xF9,
- 0x0A, 0x1A, 0x2A, 0x3A, 0x4A, 0x5A, 0x6A, 0x7A,
- 0x8A, 0x9A, 0xAA, 0xBA, 0xCA, 0xDA, 0xEA, 0xFA,
- 0x0B, 0x1B, 0x2B, 0x3B, 0x4B, 0x5B, 0x6B, 0x7B,
- 0x8B, 0x9B, 0xAB, 0xBB, 0xCB, 0xDB, 0xEB, 0xFB,
- 0x0C, 0x1C, 0x2C, 0x3C, 0x4C, 0x5C, 0x6C, 0x7C,
- 0x8C, 0x9C, 0xAC, 0xBC, 0xCC, 0xDC, 0xEC, 0xFC,
- 0x0D, 0x1D, 0x2D, 0x3D, 0x4D, 0x5D, 0x6D, 0x7D,
- 0x8D, 0x9D, 0xAD, 0xBD, 0xCD, 0xDD, 0xED, 0xFD,
- 0x0E, 0x1E, 0x2E, 0x3E, 0x4E, 0x5E, 0x6E, 0x7E,
- 0x8E, 0x9E, 0xAE, 0xBE, 0xCE, 0xDE, 0xEE, 0xFE,
- 0x0F, 0x1F, 0x2F, 0x3F, 0x4F, 0x5F, 0x6F, 0x7F,
- 0x8F, 0x9F, 0xAF, 0xBF, 0xCF, 0xDF, 0xEF, 0xFF
-};
-
-/* Swaps pixel packing order within bytes */
-void /* PRIVATE */
-png_do_packswap(png_row_infop row_info, png_bytep row)
-{
- png_debug(1, "in png_do_packswap");
-
- if (row_info->bit_depth < 8)
- {
- png_bytep rp;
- png_const_bytep end, table;
-
- end = row + row_info->rowbytes;
-
- if (row_info->bit_depth == 1)
- table = onebppswaptable;
-
- else if (row_info->bit_depth == 2)
- table = twobppswaptable;
-
- else if (row_info->bit_depth == 4)
- table = fourbppswaptable;
-
- else
- return;
-
- for (rp = row; rp < end; rp++)
- *rp = table[*rp];
- }
-}
-#endif /* PNG_READ_PACKSWAP_SUPPORTED or PNG_WRITE_PACKSWAP_SUPPORTED */
-
-#if defined(PNG_WRITE_FILLER_SUPPORTED) || \
- defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
-/* Remove a channel - this used to be 'png_do_strip_filler' but it used a
- * somewhat weird combination of flags to determine what to do. All the calls
- * to png_do_strip_filler are changed in 1.5.2 to call this instead with the
- * correct arguments.
- *
- * The routine isn't general - the channel must be the channel at the start or
- * end (not in the middle) of each pixel.
- */
-void /* PRIVATE */
-png_do_strip_channel(png_row_infop row_info, png_bytep row, int at_start)
-{
- png_bytep sp = row; /* source pointer */
- png_bytep dp = row; /* destination pointer */
- png_bytep ep = row + row_info->rowbytes; /* One beyond end of row */
-
- /* At the start sp will point to the first byte to copy and dp to where
- * it is copied to. ep always points just beyond the end of the row, so
- * the loop simply copies (channels-1) channels until sp reaches ep.
- *
- * at_start: 0 -- convert AG, XG, ARGB, XRGB, AAGG, XXGG, etc.
- * nonzero -- convert GA, GX, RGBA, RGBX, GGAA, RRGGBBXX, etc.
- */
-
- /* GA, GX, XG cases */
- if (row_info->channels == 2)
- {
- if (row_info->bit_depth == 8)
- {
- if (at_start) /* Skip initial filler */
- ++sp;
- else /* Skip initial channel and, for sp, the filler */
- sp += 2, ++dp;
-
- /* For a 1 pixel wide image there is nothing to do */
- while (sp < ep)
- *dp++ = *sp, sp += 2;
-
- row_info->pixel_depth = 8;
- }
-
- else if (row_info->bit_depth == 16)
- {
- if (at_start) /* Skip initial filler */
- sp += 2;
- else /* Skip initial channel and, for sp, the filler */
- sp += 4, dp += 2;
-
- while (sp < ep)
- *dp++ = *sp++, *dp++ = *sp, sp += 3;
-
- row_info->pixel_depth = 16;
- }
-
- else
- return; /* bad bit depth */
-
- row_info->channels = 1;
-
- /* Finally fix the color type if it records an alpha channel */
- if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
- row_info->color_type = PNG_COLOR_TYPE_GRAY;
- }
-
- /* RGBA, RGBX, XRGB cases */
- else if (row_info->channels == 4)
- {
- if (row_info->bit_depth == 8)
- {
- if (at_start) /* Skip initial filler */
- ++sp;
- else /* Skip initial channels and, for sp, the filler */
- sp += 4, dp += 3;
-
- /* Note that the loop adds 3 to dp and 4 to sp each time. */
- while (sp < ep)
- *dp++ = *sp++, *dp++ = *sp++, *dp++ = *sp, sp += 2;
-
- row_info->pixel_depth = 24;
- }
-
- else if (row_info->bit_depth == 16)
- {
- if (at_start) /* Skip initial filler */
- sp += 2;
- else /* Skip initial channels and, for sp, the filler */
- sp += 8, dp += 6;
-
- while (sp < ep)
- {
- /* Copy 6 bytes, skip 2 */
- *dp++ = *sp++, *dp++ = *sp++;
- *dp++ = *sp++, *dp++ = *sp++;
- *dp++ = *sp++, *dp++ = *sp, sp += 3;
- }
-
- row_info->pixel_depth = 48;
- }
-
- else
- return; /* bad bit depth */
-
- row_info->channels = 3;
-
- /* Finally fix the color type if it records an alpha channel */
- if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
- row_info->color_type = PNG_COLOR_TYPE_RGB;
- }
-
- else
- return; /* The filler channel has gone already */
-
- /* Fix the rowbytes value. */
- row_info->rowbytes = dp-row;
-}
-#endif
-
-#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
-/* Swaps red and blue bytes within a pixel */
-void /* PRIVATE */
-png_do_bgr(png_row_infop row_info, png_bytep row)
-{
- png_debug(1, "in png_do_bgr");
-
- if ((row_info->color_type & PNG_COLOR_MASK_COLOR))
- {
- png_uint_32 row_width = row_info->width;
- if (row_info->bit_depth == 8)
- {
- if (row_info->color_type == PNG_COLOR_TYPE_RGB)
- {
- png_bytep rp;
- png_uint_32 i;
-
- for (i = 0, rp = row; i < row_width; i++, rp += 3)
- {
- png_byte save = *rp;
- *rp = *(rp + 2);
- *(rp + 2) = save;
- }
- }
-
- else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
- {
- png_bytep rp;
- png_uint_32 i;
-
- for (i = 0, rp = row; i < row_width; i++, rp += 4)
- {
- png_byte save = *rp;
- *rp = *(rp + 2);
- *(rp + 2) = save;
- }
- }
- }
-
-#ifdef PNG_16BIT_SUPPORTED
- else if (row_info->bit_depth == 16)
- {
- if (row_info->color_type == PNG_COLOR_TYPE_RGB)
- {
- png_bytep rp;
- png_uint_32 i;
-
- for (i = 0, rp = row; i < row_width; i++, rp += 6)
- {
- png_byte save = *rp;
- *rp = *(rp + 4);
- *(rp + 4) = save;
- save = *(rp + 1);
- *(rp + 1) = *(rp + 5);
- *(rp + 5) = save;
- }
- }
-
- else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
- {
- png_bytep rp;
- png_uint_32 i;
-
- for (i = 0, rp = row; i < row_width; i++, rp += 8)
- {
- png_byte save = *rp;
- *rp = *(rp + 4);
- *(rp + 4) = save;
- save = *(rp + 1);
- *(rp + 1) = *(rp + 5);
- *(rp + 5) = save;
- }
- }
- }
-#endif
- }
-}
-#endif /* PNG_READ_BGR_SUPPORTED or PNG_WRITE_BGR_SUPPORTED */
-
-#if defined(PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED) || \
- defined(PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED)
-/* Added at libpng-1.5.10 */
-void /* PRIVATE */
-png_do_check_palette_indexes(png_structrp png_ptr, png_row_infop row_info)
-{
- if (png_ptr->num_palette < (1 << row_info->bit_depth) &&
- png_ptr->num_palette > 0) /* num_palette can be 0 in MNG files */
- {
- /* Calculations moved outside switch in an attempt to stop different
- * compiler warnings. 'padding' is in *bits* within the last byte, it is
- * an 'int' because pixel_depth becomes an 'int' in the expression below,
- * and this calculation is used because it avoids warnings that other
- * forms produced on either GCC or MSVC.
- */
- int padding = (-row_info->pixel_depth * row_info->width) & 7;
- png_bytep rp = png_ptr->row_buf + row_info->rowbytes;
-
- switch (row_info->bit_depth)
- {
- case 1:
- {
- /* in this case, all bytes must be 0 so we don't need
- * to unpack the pixels except for the rightmost one.
- */
- for (; rp > png_ptr->row_buf; rp--)
- {
- if (*rp >> padding != 0)
- png_ptr->num_palette_max = 1;
- padding = 0;
- }
-
- break;
- }
-
- case 2:
- {
- for (; rp > png_ptr->row_buf; rp--)
- {
- int i = ((*rp >> padding) & 0x03);
-
- if (i > png_ptr->num_palette_max)
- png_ptr->num_palette_max = i;
-
- i = (((*rp >> padding) >> 2) & 0x03);
-
- if (i > png_ptr->num_palette_max)
- png_ptr->num_palette_max = i;
-
- i = (((*rp >> padding) >> 4) & 0x03);
-
- if (i > png_ptr->num_palette_max)
- png_ptr->num_palette_max = i;
-
- i = (((*rp >> padding) >> 6) & 0x03);
-
- if (i > png_ptr->num_palette_max)
- png_ptr->num_palette_max = i;
-
- padding = 0;
- }
-
- break;
- }
-
- case 4:
- {
- for (; rp > png_ptr->row_buf; rp--)
- {
- int i = ((*rp >> padding) & 0x0f);
-
- if (i > png_ptr->num_palette_max)
- png_ptr->num_palette_max = i;
-
- i = (((*rp >> padding) >> 4) & 0x0f);
-
- if (i > png_ptr->num_palette_max)
- png_ptr->num_palette_max = i;
-
- padding = 0;
- }
-
- break;
- }
-
- case 8:
- {
- for (; rp > png_ptr->row_buf; rp--)
- {
- if (*rp > png_ptr->num_palette_max)
- png_ptr->num_palette_max = (int) *rp;
- }
-
- break;
- }
-
- default:
- break;
- }
- }
-}
-#endif /* PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED */
-
-#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
- defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
-#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
-void PNGAPI
-png_set_user_transform_info(png_structrp png_ptr, png_voidp
- user_transform_ptr, int user_transform_depth, int user_transform_channels)
-{
- png_debug(1, "in png_set_user_transform_info");
-
- if (png_ptr == NULL)
- return;
-
-#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
- if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0 &&
- (png_ptr->flags & PNG_FLAG_ROW_INIT) != 0)
- {
- png_app_error(png_ptr,
- "info change after png_start_read_image or png_read_update_info");
- return;
- }
-#endif
-
- png_ptr->user_transform_ptr = user_transform_ptr;
- png_ptr->user_transform_depth = (png_byte)user_transform_depth;
- png_ptr->user_transform_channels = (png_byte)user_transform_channels;
-}
-#endif
-
-/* This function returns a pointer to the user_transform_ptr associated with
- * the user transform functions. The application should free any memory
- * associated with this pointer before png_write_destroy and png_read_destroy
- * are called.
- */
-#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
-png_voidp PNGAPI
-png_get_user_transform_ptr(png_const_structrp png_ptr)
-{
- if (png_ptr == NULL)
- return (NULL);
-
- return png_ptr->user_transform_ptr;
-}
-#endif
-
-#ifdef PNG_USER_TRANSFORM_INFO_SUPPORTED
-png_uint_32 PNGAPI
-png_get_current_row_number(png_const_structrp png_ptr)
-{
- /* See the comments in png.h - this is the sub-image row when reading and
- * interlaced image.
- */
- if (png_ptr != NULL)
- return png_ptr->row_number;
-
- return PNG_UINT_32_MAX; /* help the app not to fail silently */
-}
-
-png_byte PNGAPI
-png_get_current_pass_number(png_const_structrp png_ptr)
-{
- if (png_ptr != NULL)
- return png_ptr->pass;
- return 8; /* invalid */
-}
-#endif /* PNG_USER_TRANSFORM_INFO_SUPPORTED */
-#endif /* PNG_READ_USER_TRANSFORM_SUPPORTED ||
- PNG_WRITE_USER_TRANSFORM_SUPPORTED */
-#endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */
+
+/* pngtrans.c - transforms the data in a row (used by both readers and writers)
+ *
+ * Last changed in libpng 1.6.18 [July 23, 2015]
+ * Copyright (c) 1998-2015 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+
+#include "pngpriv.h"
+
+#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
+
+#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
+/* Turn on BGR-to-RGB mapping */
+void PNGAPI
+png_set_bgr(png_structrp png_ptr)
+{
+ png_debug(1, "in png_set_bgr");
+
+ if (png_ptr == NULL)
+ return;
+
+ png_ptr->transformations |= PNG_BGR;
+}
+#endif
+
+#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
+/* Turn on 16-bit byte swapping */
+void PNGAPI
+png_set_swap(png_structrp png_ptr)
+{
+ png_debug(1, "in png_set_swap");
+
+ if (png_ptr == NULL)
+ return;
+
+ if (png_ptr->bit_depth == 16)
+ png_ptr->transformations |= PNG_SWAP_BYTES;
+}
+#endif
+
+#if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
+/* Turn on pixel packing */
+void PNGAPI
+png_set_packing(png_structrp png_ptr)
+{
+ png_debug(1, "in png_set_packing");
+
+ if (png_ptr == NULL)
+ return;
+
+ if (png_ptr->bit_depth < 8)
+ {
+ png_ptr->transformations |= PNG_PACK;
+# ifdef PNG_WRITE_SUPPORTED
+ png_ptr->usr_bit_depth = 8;
+# endif
+ }
+}
+#endif
+
+#if defined(PNG_READ_PACKSWAP_SUPPORTED)||defined(PNG_WRITE_PACKSWAP_SUPPORTED)
+/* Turn on packed pixel swapping */
+void PNGAPI
+png_set_packswap(png_structrp png_ptr)
+{
+ png_debug(1, "in png_set_packswap");
+
+ if (png_ptr == NULL)
+ return;
+
+ if (png_ptr->bit_depth < 8)
+ png_ptr->transformations |= PNG_PACKSWAP;
+}
+#endif
+
+#if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
+void PNGAPI
+png_set_shift(png_structrp png_ptr, png_const_color_8p true_bits)
+{
+ png_debug(1, "in png_set_shift");
+
+ if (png_ptr == NULL)
+ return;
+
+ png_ptr->transformations |= PNG_SHIFT;
+ png_ptr->shift = *true_bits;
+}
+#endif
+
+#if defined(PNG_READ_INTERLACING_SUPPORTED) || \
+ defined(PNG_WRITE_INTERLACING_SUPPORTED)
+int PNGAPI
+png_set_interlace_handling(png_structrp png_ptr)
+{
+ png_debug(1, "in png_set_interlace handling");
+
+ if (png_ptr != 0 && png_ptr->interlaced != 0)
+ {
+ png_ptr->transformations |= PNG_INTERLACE;
+ return (7);
+ }
+
+ return (1);
+}
+#endif
+
+#if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
+/* Add a filler byte on read, or remove a filler or alpha byte on write.
+ * The filler type has changed in v0.95 to allow future 2-byte fillers
+ * for 48-bit input data, as well as to avoid problems with some compilers
+ * that don't like bytes as parameters.
+ */
+void PNGAPI
+png_set_filler(png_structrp png_ptr, png_uint_32 filler, int filler_loc)
+{
+ png_debug(1, "in png_set_filler");
+
+ if (png_ptr == NULL)
+ return;
+
+ /* In libpng 1.6 it is possible to determine whether this is a read or write
+ * operation and therefore to do more checking here for a valid call.
+ */
+ if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0)
+ {
+# ifdef PNG_READ_FILLER_SUPPORTED
+ /* On read png_set_filler is always valid, regardless of the base PNG
+ * format, because other transformations can give a format where the
+ * filler code can execute (basically an 8 or 16-bit component RGB or G
+ * format.)
+ *
+ * NOTE: usr_channels is not used by the read code! (This has led to
+ * confusion in the past.) The filler is only used in the read code.
+ */
+ png_ptr->filler = (png_uint_16)filler;
+# else
+ png_app_error(png_ptr, "png_set_filler not supported on read");
+ PNG_UNUSED(filler) /* not used in the write case */
+ return;
+# endif
+ }
+
+ else /* write */
+ {
+# ifdef PNG_WRITE_FILLER_SUPPORTED
+ /* On write the usr_channels parameter must be set correctly at the
+ * start to record the number of channels in the app-supplied data.
+ */
+ switch (png_ptr->color_type)
+ {
+ case PNG_COLOR_TYPE_RGB:
+ png_ptr->usr_channels = 4;
+ break;
+
+ case PNG_COLOR_TYPE_GRAY:
+ if (png_ptr->bit_depth >= 8)
+ {
+ png_ptr->usr_channels = 2;
+ break;
+ }
+
+ else
+ {
+ /* There simply isn't any code in libpng to strip out bits
+ * from bytes when the components are less than a byte in
+ * size!
+ */
+ png_app_error(png_ptr,
+ "png_set_filler is invalid for low bit depth gray output");
+ return;
+ }
+
+ default:
+ png_app_error(png_ptr,
+ "png_set_filler: inappropriate color type");
+ return;
+ }
+# else
+ png_app_error(png_ptr, "png_set_filler not supported on write");
+ return;
+# endif
+ }
+
+ /* Here on success - libpng supports the operation, set the transformation
+ * and the flag to say where the filler channel is.
+ */
+ png_ptr->transformations |= PNG_FILLER;
+
+ if (filler_loc == PNG_FILLER_AFTER)
+ png_ptr->flags |= PNG_FLAG_FILLER_AFTER;
+
+ else
+ png_ptr->flags &= ~PNG_FLAG_FILLER_AFTER;
+}
+
+/* Added to libpng-1.2.7 */
+void PNGAPI
+png_set_add_alpha(png_structrp png_ptr, png_uint_32 filler, int filler_loc)
+{
+ png_debug(1, "in png_set_add_alpha");
+
+ if (png_ptr == NULL)
+ return;
+
+ png_set_filler(png_ptr, filler, filler_loc);
+ /* The above may fail to do anything. */
+ if ((png_ptr->transformations & PNG_FILLER) != 0)
+ png_ptr->transformations |= PNG_ADD_ALPHA;
+}
+
+#endif
+
+#if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \
+ defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
+void PNGAPI
+png_set_swap_alpha(png_structrp png_ptr)
+{
+ png_debug(1, "in png_set_swap_alpha");
+
+ if (png_ptr == NULL)
+ return;
+
+ png_ptr->transformations |= PNG_SWAP_ALPHA;
+}
+#endif
+
+#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \
+ defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
+void PNGAPI
+png_set_invert_alpha(png_structrp png_ptr)
+{
+ png_debug(1, "in png_set_invert_alpha");
+
+ if (png_ptr == NULL)
+ return;
+
+ png_ptr->transformations |= PNG_INVERT_ALPHA;
+}
+#endif
+
+#if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
+void PNGAPI
+png_set_invert_mono(png_structrp png_ptr)
+{
+ png_debug(1, "in png_set_invert_mono");
+
+ if (png_ptr == NULL)
+ return;
+
+ png_ptr->transformations |= PNG_INVERT_MONO;
+}
+
+/* Invert monochrome grayscale data */
+void /* PRIVATE */
+png_do_invert(png_row_infop row_info, png_bytep row)
+{
+ png_debug(1, "in png_do_invert");
+
+ /* This test removed from libpng version 1.0.13 and 1.2.0:
+ * if (row_info->bit_depth == 1 &&
+ */
+ if (row_info->color_type == PNG_COLOR_TYPE_GRAY)
+ {
+ png_bytep rp = row;
+ png_size_t i;
+ png_size_t istop = row_info->rowbytes;
+
+ for (i = 0; i < istop; i++)
+ {
+ *rp = (png_byte)(~(*rp));
+ rp++;
+ }
+ }
+
+ else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA &&
+ row_info->bit_depth == 8)
+ {
+ png_bytep rp = row;
+ png_size_t i;
+ png_size_t istop = row_info->rowbytes;
+
+ for (i = 0; i < istop; i += 2)
+ {
+ *rp = (png_byte)(~(*rp));
+ rp += 2;
+ }
+ }
+
+#ifdef PNG_16BIT_SUPPORTED
+ else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA &&
+ row_info->bit_depth == 16)
+ {
+ png_bytep rp = row;
+ png_size_t i;
+ png_size_t istop = row_info->rowbytes;
+
+ for (i = 0; i < istop; i += 4)
+ {
+ *rp = (png_byte)(~(*rp));
+ *(rp + 1) = (png_byte)(~(*(rp + 1)));
+ rp += 4;
+ }
+ }
+#endif
+}
+#endif
+
+#ifdef PNG_16BIT_SUPPORTED
+#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
+/* Swaps byte order on 16-bit depth images */
+void /* PRIVATE */
+png_do_swap(png_row_infop row_info, png_bytep row)
+{
+ png_debug(1, "in png_do_swap");
+
+ if (row_info->bit_depth == 16)
+ {
+ png_bytep rp = row;
+ png_uint_32 i;
+ png_uint_32 istop= row_info->width * row_info->channels;
+
+ for (i = 0; i < istop; i++, rp += 2)
+ {
+#ifdef PNG_BUILTIN_BSWAP16_SUPPORTED
+ /* Feature added to libpng-1.6.11 for testing purposes, not
+ * enabled by default.
+ */
+ *(png_uint_16*)rp = __builtin_bswap16(*(png_uint_16*)rp);
+#else
+ png_byte t = *rp;
+ *rp = *(rp + 1);
+ *(rp + 1) = t;
+#endif
+ }
+ }
+}
+#endif
+#endif
+
+#if defined(PNG_READ_PACKSWAP_SUPPORTED)||defined(PNG_WRITE_PACKSWAP_SUPPORTED)
+static PNG_CONST png_byte onebppswaptable[256] = {
+ 0x00, 0x80, 0x40, 0xC0, 0x20, 0xA0, 0x60, 0xE0,
+ 0x10, 0x90, 0x50, 0xD0, 0x30, 0xB0, 0x70, 0xF0,
+ 0x08, 0x88, 0x48, 0xC8, 0x28, 0xA8, 0x68, 0xE8,
+ 0x18, 0x98, 0x58, 0xD8, 0x38, 0xB8, 0x78, 0xF8,
+ 0x04, 0x84, 0x44, 0xC4, 0x24, 0xA4, 0x64, 0xE4,
+ 0x14, 0x94, 0x54, 0xD4, 0x34, 0xB4, 0x74, 0xF4,
+ 0x0C, 0x8C, 0x4C, 0xCC, 0x2C, 0xAC, 0x6C, 0xEC,
+ 0x1C, 0x9C, 0x5C, 0xDC, 0x3C, 0xBC, 0x7C, 0xFC,
+ 0x02, 0x82, 0x42, 0xC2, 0x22, 0xA2, 0x62, 0xE2,
+ 0x12, 0x92, 0x52, 0xD2, 0x32, 0xB2, 0x72, 0xF2,
+ 0x0A, 0x8A, 0x4A, 0xCA, 0x2A, 0xAA, 0x6A, 0xEA,
+ 0x1A, 0x9A, 0x5A, 0xDA, 0x3A, 0xBA, 0x7A, 0xFA,
+ 0x06, 0x86, 0x46, 0xC6, 0x26, 0xA6, 0x66, 0xE6,
+ 0x16, 0x96, 0x56, 0xD6, 0x36, 0xB6, 0x76, 0xF6,
+ 0x0E, 0x8E, 0x4E, 0xCE, 0x2E, 0xAE, 0x6E, 0xEE,
+ 0x1E, 0x9E, 0x5E, 0xDE, 0x3E, 0xBE, 0x7E, 0xFE,
+ 0x01, 0x81, 0x41, 0xC1, 0x21, 0xA1, 0x61, 0xE1,
+ 0x11, 0x91, 0x51, 0xD1, 0x31, 0xB1, 0x71, 0xF1,
+ 0x09, 0x89, 0x49, 0xC9, 0x29, 0xA9, 0x69, 0xE9,
+ 0x19, 0x99, 0x59, 0xD9, 0x39, 0xB9, 0x79, 0xF9,
+ 0x05, 0x85, 0x45, 0xC5, 0x25, 0xA5, 0x65, 0xE5,
+ 0x15, 0x95, 0x55, 0xD5, 0x35, 0xB5, 0x75, 0xF5,
+ 0x0D, 0x8D, 0x4D, 0xCD, 0x2D, 0xAD, 0x6D, 0xED,
+ 0x1D, 0x9D, 0x5D, 0xDD, 0x3D, 0xBD, 0x7D, 0xFD,
+ 0x03, 0x83, 0x43, 0xC3, 0x23, 0xA3, 0x63, 0xE3,
+ 0x13, 0x93, 0x53, 0xD3, 0x33, 0xB3, 0x73, 0xF3,
+ 0x0B, 0x8B, 0x4B, 0xCB, 0x2B, 0xAB, 0x6B, 0xEB,
+ 0x1B, 0x9B, 0x5B, 0xDB, 0x3B, 0xBB, 0x7B, 0xFB,
+ 0x07, 0x87, 0x47, 0xC7, 0x27, 0xA7, 0x67, 0xE7,
+ 0x17, 0x97, 0x57, 0xD7, 0x37, 0xB7, 0x77, 0xF7,
+ 0x0F, 0x8F, 0x4F, 0xCF, 0x2F, 0xAF, 0x6F, 0xEF,
+ 0x1F, 0x9F, 0x5F, 0xDF, 0x3F, 0xBF, 0x7F, 0xFF
+};
+
+static PNG_CONST png_byte twobppswaptable[256] = {
+ 0x00, 0x40, 0x80, 0xC0, 0x10, 0x50, 0x90, 0xD0,
+ 0x20, 0x60, 0xA0, 0xE0, 0x30, 0x70, 0xB0, 0xF0,
+ 0x04, 0x44, 0x84, 0xC4, 0x14, 0x54, 0x94, 0xD4,
+ 0x24, 0x64, 0xA4, 0xE4, 0x34, 0x74, 0xB4, 0xF4,
+ 0x08, 0x48, 0x88, 0xC8, 0x18, 0x58, 0x98, 0xD8,
+ 0x28, 0x68, 0xA8, 0xE8, 0x38, 0x78, 0xB8, 0xF8,
+ 0x0C, 0x4C, 0x8C, 0xCC, 0x1C, 0x5C, 0x9C, 0xDC,
+ 0x2C, 0x6C, 0xAC, 0xEC, 0x3C, 0x7C, 0xBC, 0xFC,
+ 0x01, 0x41, 0x81, 0xC1, 0x11, 0x51, 0x91, 0xD1,
+ 0x21, 0x61, 0xA1, 0xE1, 0x31, 0x71, 0xB1, 0xF1,
+ 0x05, 0x45, 0x85, 0xC5, 0x15, 0x55, 0x95, 0xD5,
+ 0x25, 0x65, 0xA5, 0xE5, 0x35, 0x75, 0xB5, 0xF5,
+ 0x09, 0x49, 0x89, 0xC9, 0x19, 0x59, 0x99, 0xD9,
+ 0x29, 0x69, 0xA9, 0xE9, 0x39, 0x79, 0xB9, 0xF9,
+ 0x0D, 0x4D, 0x8D, 0xCD, 0x1D, 0x5D, 0x9D, 0xDD,
+ 0x2D, 0x6D, 0xAD, 0xED, 0x3D, 0x7D, 0xBD, 0xFD,
+ 0x02, 0x42, 0x82, 0xC2, 0x12, 0x52, 0x92, 0xD2,
+ 0x22, 0x62, 0xA2, 0xE2, 0x32, 0x72, 0xB2, 0xF2,
+ 0x06, 0x46, 0x86, 0xC6, 0x16, 0x56, 0x96, 0xD6,
+ 0x26, 0x66, 0xA6, 0xE6, 0x36, 0x76, 0xB6, 0xF6,
+ 0x0A, 0x4A, 0x8A, 0xCA, 0x1A, 0x5A, 0x9A, 0xDA,
+ 0x2A, 0x6A, 0xAA, 0xEA, 0x3A, 0x7A, 0xBA, 0xFA,
+ 0x0E, 0x4E, 0x8E, 0xCE, 0x1E, 0x5E, 0x9E, 0xDE,
+ 0x2E, 0x6E, 0xAE, 0xEE, 0x3E, 0x7E, 0xBE, 0xFE,
+ 0x03, 0x43, 0x83, 0xC3, 0x13, 0x53, 0x93, 0xD3,
+ 0x23, 0x63, 0xA3, 0xE3, 0x33, 0x73, 0xB3, 0xF3,
+ 0x07, 0x47, 0x87, 0xC7, 0x17, 0x57, 0x97, 0xD7,
+ 0x27, 0x67, 0xA7, 0xE7, 0x37, 0x77, 0xB7, 0xF7,
+ 0x0B, 0x4B, 0x8B, 0xCB, 0x1B, 0x5B, 0x9B, 0xDB,
+ 0x2B, 0x6B, 0xAB, 0xEB, 0x3B, 0x7B, 0xBB, 0xFB,
+ 0x0F, 0x4F, 0x8F, 0xCF, 0x1F, 0x5F, 0x9F, 0xDF,
+ 0x2F, 0x6F, 0xAF, 0xEF, 0x3F, 0x7F, 0xBF, 0xFF
+};
+
+static PNG_CONST png_byte fourbppswaptable[256] = {
+ 0x00, 0x10, 0x20, 0x30, 0x40, 0x50, 0x60, 0x70,
+ 0x80, 0x90, 0xA0, 0xB0, 0xC0, 0xD0, 0xE0, 0xF0,
+ 0x01, 0x11, 0x21, 0x31, 0x41, 0x51, 0x61, 0x71,
+ 0x81, 0x91, 0xA1, 0xB1, 0xC1, 0xD1, 0xE1, 0xF1,
+ 0x02, 0x12, 0x22, 0x32, 0x42, 0x52, 0x62, 0x72,
+ 0x82, 0x92, 0xA2, 0xB2, 0xC2, 0xD2, 0xE2, 0xF2,
+ 0x03, 0x13, 0x23, 0x33, 0x43, 0x53, 0x63, 0x73,
+ 0x83, 0x93, 0xA3, 0xB3, 0xC3, 0xD3, 0xE3, 0xF3,
+ 0x04, 0x14, 0x24, 0x34, 0x44, 0x54, 0x64, 0x74,
+ 0x84, 0x94, 0xA4, 0xB4, 0xC4, 0xD4, 0xE4, 0xF4,
+ 0x05, 0x15, 0x25, 0x35, 0x45, 0x55, 0x65, 0x75,
+ 0x85, 0x95, 0xA5, 0xB5, 0xC5, 0xD5, 0xE5, 0xF5,
+ 0x06, 0x16, 0x26, 0x36, 0x46, 0x56, 0x66, 0x76,
+ 0x86, 0x96, 0xA6, 0xB6, 0xC6, 0xD6, 0xE6, 0xF6,
+ 0x07, 0x17, 0x27, 0x37, 0x47, 0x57, 0x67, 0x77,
+ 0x87, 0x97, 0xA7, 0xB7, 0xC7, 0xD7, 0xE7, 0xF7,
+ 0x08, 0x18, 0x28, 0x38, 0x48, 0x58, 0x68, 0x78,
+ 0x88, 0x98, 0xA8, 0xB8, 0xC8, 0xD8, 0xE8, 0xF8,
+ 0x09, 0x19, 0x29, 0x39, 0x49, 0x59, 0x69, 0x79,
+ 0x89, 0x99, 0xA9, 0xB9, 0xC9, 0xD9, 0xE9, 0xF9,
+ 0x0A, 0x1A, 0x2A, 0x3A, 0x4A, 0x5A, 0x6A, 0x7A,
+ 0x8A, 0x9A, 0xAA, 0xBA, 0xCA, 0xDA, 0xEA, 0xFA,
+ 0x0B, 0x1B, 0x2B, 0x3B, 0x4B, 0x5B, 0x6B, 0x7B,
+ 0x8B, 0x9B, 0xAB, 0xBB, 0xCB, 0xDB, 0xEB, 0xFB,
+ 0x0C, 0x1C, 0x2C, 0x3C, 0x4C, 0x5C, 0x6C, 0x7C,
+ 0x8C, 0x9C, 0xAC, 0xBC, 0xCC, 0xDC, 0xEC, 0xFC,
+ 0x0D, 0x1D, 0x2D, 0x3D, 0x4D, 0x5D, 0x6D, 0x7D,
+ 0x8D, 0x9D, 0xAD, 0xBD, 0xCD, 0xDD, 0xED, 0xFD,
+ 0x0E, 0x1E, 0x2E, 0x3E, 0x4E, 0x5E, 0x6E, 0x7E,
+ 0x8E, 0x9E, 0xAE, 0xBE, 0xCE, 0xDE, 0xEE, 0xFE,
+ 0x0F, 0x1F, 0x2F, 0x3F, 0x4F, 0x5F, 0x6F, 0x7F,
+ 0x8F, 0x9F, 0xAF, 0xBF, 0xCF, 0xDF, 0xEF, 0xFF
+};
+
+/* Swaps pixel packing order within bytes */
+void /* PRIVATE */
+png_do_packswap(png_row_infop row_info, png_bytep row)
+{
+ png_debug(1, "in png_do_packswap");
+
+ if (row_info->bit_depth < 8)
+ {
+ png_bytep rp;
+ png_const_bytep end, table;
+
+ end = row + row_info->rowbytes;
+
+ if (row_info->bit_depth == 1)
+ table = onebppswaptable;
+
+ else if (row_info->bit_depth == 2)
+ table = twobppswaptable;
+
+ else if (row_info->bit_depth == 4)
+ table = fourbppswaptable;
+
+ else
+ return;
+
+ for (rp = row; rp < end; rp++)
+ *rp = table[*rp];
+ }
+}
+#endif /* PACKSWAP || WRITE_PACKSWAP */
+
+#if defined(PNG_WRITE_FILLER_SUPPORTED) || \
+ defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
+/* Remove a channel - this used to be 'png_do_strip_filler' but it used a
+ * somewhat weird combination of flags to determine what to do. All the calls
+ * to png_do_strip_filler are changed in 1.5.2 to call this instead with the
+ * correct arguments.
+ *
+ * The routine isn't general - the channel must be the channel at the start or
+ * end (not in the middle) of each pixel.
+ */
+void /* PRIVATE */
+png_do_strip_channel(png_row_infop row_info, png_bytep row, int at_start)
+{
+ png_bytep sp = row; /* source pointer */
+ png_bytep dp = row; /* destination pointer */
+ png_bytep ep = row + row_info->rowbytes; /* One beyond end of row */
+
+ /* At the start sp will point to the first byte to copy and dp to where
+ * it is copied to. ep always points just beyond the end of the row, so
+ * the loop simply copies (channels-1) channels until sp reaches ep.
+ *
+ * at_start: 0 -- convert AG, XG, ARGB, XRGB, AAGG, XXGG, etc.
+ * nonzero -- convert GA, GX, RGBA, RGBX, GGAA, RRGGBBXX, etc.
+ */
+
+ /* GA, GX, XG cases */
+ if (row_info->channels == 2)
+ {
+ if (row_info->bit_depth == 8)
+ {
+ if (at_start != 0) /* Skip initial filler */
+ ++sp;
+ else /* Skip initial channel and, for sp, the filler */
+ sp += 2, ++dp;
+
+ /* For a 1 pixel wide image there is nothing to do */
+ while (sp < ep)
+ *dp++ = *sp, sp += 2;
+
+ row_info->pixel_depth = 8;
+ }
+
+ else if (row_info->bit_depth == 16)
+ {
+ if (at_start != 0) /* Skip initial filler */
+ sp += 2;
+ else /* Skip initial channel and, for sp, the filler */
+ sp += 4, dp += 2;
+
+ while (sp < ep)
+ *dp++ = *sp++, *dp++ = *sp, sp += 3;
+
+ row_info->pixel_depth = 16;
+ }
+
+ else
+ return; /* bad bit depth */
+
+ row_info->channels = 1;
+
+ /* Finally fix the color type if it records an alpha channel */
+ if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+ row_info->color_type = PNG_COLOR_TYPE_GRAY;
+ }
+
+ /* RGBA, RGBX, XRGB cases */
+ else if (row_info->channels == 4)
+ {
+ if (row_info->bit_depth == 8)
+ {
+ if (at_start != 0) /* Skip initial filler */
+ ++sp;
+ else /* Skip initial channels and, for sp, the filler */
+ sp += 4, dp += 3;
+
+ /* Note that the loop adds 3 to dp and 4 to sp each time. */
+ while (sp < ep)
+ *dp++ = *sp++, *dp++ = *sp++, *dp++ = *sp, sp += 2;
+
+ row_info->pixel_depth = 24;
+ }
+
+ else if (row_info->bit_depth == 16)
+ {
+ if (at_start != 0) /* Skip initial filler */
+ sp += 2;
+ else /* Skip initial channels and, for sp, the filler */
+ sp += 8, dp += 6;
+
+ while (sp < ep)
+ {
+ /* Copy 6 bytes, skip 2 */
+ *dp++ = *sp++, *dp++ = *sp++;
+ *dp++ = *sp++, *dp++ = *sp++;
+ *dp++ = *sp++, *dp++ = *sp, sp += 3;
+ }
+
+ row_info->pixel_depth = 48;
+ }
+
+ else
+ return; /* bad bit depth */
+
+ row_info->channels = 3;
+
+ /* Finally fix the color type if it records an alpha channel */
+ if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+ row_info->color_type = PNG_COLOR_TYPE_RGB;
+ }
+
+ else
+ return; /* The filler channel has gone already */
+
+ /* Fix the rowbytes value. */
+ row_info->rowbytes = dp-row;
+}
+#endif
+
+#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
+/* Swaps red and blue bytes within a pixel */
+void /* PRIVATE */
+png_do_bgr(png_row_infop row_info, png_bytep row)
+{
+ png_debug(1, "in png_do_bgr");
+
+ if ((row_info->color_type & PNG_COLOR_MASK_COLOR) != 0)
+ {
+ png_uint_32 row_width = row_info->width;
+ if (row_info->bit_depth == 8)
+ {
+ if (row_info->color_type == PNG_COLOR_TYPE_RGB)
+ {
+ png_bytep rp;
+ png_uint_32 i;
+
+ for (i = 0, rp = row; i < row_width; i++, rp += 3)
+ {
+ png_byte save = *rp;
+ *rp = *(rp + 2);
+ *(rp + 2) = save;
+ }
+ }
+
+ else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+ {
+ png_bytep rp;
+ png_uint_32 i;
+
+ for (i = 0, rp = row; i < row_width; i++, rp += 4)
+ {
+ png_byte save = *rp;
+ *rp = *(rp + 2);
+ *(rp + 2) = save;
+ }
+ }
+ }
+
+#ifdef PNG_16BIT_SUPPORTED
+ else if (row_info->bit_depth == 16)
+ {
+ if (row_info->color_type == PNG_COLOR_TYPE_RGB)
+ {
+ png_bytep rp;
+ png_uint_32 i;
+
+ for (i = 0, rp = row; i < row_width; i++, rp += 6)
+ {
+ png_byte save = *rp;
+ *rp = *(rp + 4);
+ *(rp + 4) = save;
+ save = *(rp + 1);
+ *(rp + 1) = *(rp + 5);
+ *(rp + 5) = save;
+ }
+ }
+
+ else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+ {
+ png_bytep rp;
+ png_uint_32 i;
+
+ for (i = 0, rp = row; i < row_width; i++, rp += 8)
+ {
+ png_byte save = *rp;
+ *rp = *(rp + 4);
+ *(rp + 4) = save;
+ save = *(rp + 1);
+ *(rp + 1) = *(rp + 5);
+ *(rp + 5) = save;
+ }
+ }
+ }
+#endif
+ }
+}
+#endif /* READ_BGR || WRITE_BGR */
+
+#if defined(PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED) || \
+ defined(PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED)
+/* Added at libpng-1.5.10 */
+void /* PRIVATE */
+png_do_check_palette_indexes(png_structrp png_ptr, png_row_infop row_info)
+{
+ if (png_ptr->num_palette < (1 << row_info->bit_depth) &&
+ png_ptr->num_palette > 0) /* num_palette can be 0 in MNG files */
+ {
+ /* Calculations moved outside switch in an attempt to stop different
+ * compiler warnings. 'padding' is in *bits* within the last byte, it is
+ * an 'int' because pixel_depth becomes an 'int' in the expression below,
+ * and this calculation is used because it avoids warnings that other
+ * forms produced on either GCC or MSVC.
+ */
+ int padding = (-row_info->pixel_depth * row_info->width) & 7;
+ png_bytep rp = png_ptr->row_buf + row_info->rowbytes;
+
+ switch (row_info->bit_depth)
+ {
+ case 1:
+ {
+ /* in this case, all bytes must be 0 so we don't need
+ * to unpack the pixels except for the rightmost one.
+ */
+ for (; rp > png_ptr->row_buf; rp--)
+ {
+ if ((*rp >> padding) != 0)
+ png_ptr->num_palette_max = 1;
+ padding = 0;
+ }
+
+ break;
+ }
+
+ case 2:
+ {
+ for (; rp > png_ptr->row_buf; rp--)
+ {
+ int i = ((*rp >> padding) & 0x03);
+
+ if (i > png_ptr->num_palette_max)
+ png_ptr->num_palette_max = i;
+
+ i = (((*rp >> padding) >> 2) & 0x03);
+
+ if (i > png_ptr->num_palette_max)
+ png_ptr->num_palette_max = i;
+
+ i = (((*rp >> padding) >> 4) & 0x03);
+
+ if (i > png_ptr->num_palette_max)
+ png_ptr->num_palette_max = i;
+
+ i = (((*rp >> padding) >> 6) & 0x03);
+
+ if (i > png_ptr->num_palette_max)
+ png_ptr->num_palette_max = i;
+
+ padding = 0;
+ }
+
+ break;
+ }
+
+ case 4:
+ {
+ for (; rp > png_ptr->row_buf; rp--)
+ {
+ int i = ((*rp >> padding) & 0x0f);
+
+ if (i > png_ptr->num_palette_max)
+ png_ptr->num_palette_max = i;
+
+ i = (((*rp >> padding) >> 4) & 0x0f);
+
+ if (i > png_ptr->num_palette_max)
+ png_ptr->num_palette_max = i;
+
+ padding = 0;
+ }
+
+ break;
+ }
+
+ case 8:
+ {
+ for (; rp > png_ptr->row_buf; rp--)
+ {
+ if (*rp > png_ptr->num_palette_max)
+ png_ptr->num_palette_max = (int) *rp;
+ }
+
+ break;
+ }
+
+ default:
+ break;
+ }
+ }
+}
+#endif /* CHECK_FOR_INVALID_INDEX */
+
+#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
+ defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
+#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
+void PNGAPI
+png_set_user_transform_info(png_structrp png_ptr, png_voidp
+ user_transform_ptr, int user_transform_depth, int user_transform_channels)
+{
+ png_debug(1, "in png_set_user_transform_info");
+
+ if (png_ptr == NULL)
+ return;
+
+#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
+ if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0 &&
+ (png_ptr->flags & PNG_FLAG_ROW_INIT) != 0)
+ {
+ png_app_error(png_ptr,
+ "info change after png_start_read_image or png_read_update_info");
+ return;
+ }
+#endif
+
+ png_ptr->user_transform_ptr = user_transform_ptr;
+ png_ptr->user_transform_depth = (png_byte)user_transform_depth;
+ png_ptr->user_transform_channels = (png_byte)user_transform_channels;
+}
+#endif
+
+/* This function returns a pointer to the user_transform_ptr associated with
+ * the user transform functions. The application should free any memory
+ * associated with this pointer before png_write_destroy and png_read_destroy
+ * are called.
+ */
+#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
+png_voidp PNGAPI
+png_get_user_transform_ptr(png_const_structrp png_ptr)
+{
+ if (png_ptr == NULL)
+ return (NULL);
+
+ return png_ptr->user_transform_ptr;
+}
+#endif
+
+#ifdef PNG_USER_TRANSFORM_INFO_SUPPORTED
+png_uint_32 PNGAPI
+png_get_current_row_number(png_const_structrp png_ptr)
+{
+ /* See the comments in png.h - this is the sub-image row when reading an
+ * interlaced image.
+ */
+ if (png_ptr != NULL)
+ return png_ptr->row_number;
+
+ return PNG_UINT_32_MAX; /* help the app not to fail silently */
+}
+
+png_byte PNGAPI
+png_get_current_pass_number(png_const_structrp png_ptr)
+{
+ if (png_ptr != NULL)
+ return png_ptr->pass;
+ return 8; /* invalid */
+}
+#endif /* USER_TRANSFORM_INFO */
+#endif /* READ_USER_TRANSFORM || WRITE_USER_TRANSFORM */
+#endif /* READ || WRITE */
diff --git a/third_party/lpng_v163/pngwio.c b/third_party/libpng/pngwio.c
similarity index 95%
rename from third_party/lpng_v163/pngwio.c
rename to third_party/libpng/pngwio.c
index 9268c16..db76e6b 100644
--- a/third_party/lpng_v163/pngwio.c
+++ b/third_party/libpng/pngwio.c
@@ -1,163 +1,168 @@
-
-/* pngwio.c - functions for data output
- *
- * Last changed in libpng 1.6.0 [February 14, 2013]
- * Copyright (c) 1998-2013 Glenn Randers-Pehrson
- * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
- * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
- *
- * This code is released under the libpng license.
- * For conditions of distribution and use, see the disclaimer
- * and license in png.h
- *
- * This file provides a location for all output. Users who need
- * special handling are expected to write functions that have the same
- * arguments as these and perform similar functions, but that possibly
- * use different output methods. Note that you shouldn't change these
- * functions, but rather write replacement functions and then change
- * them at run time with png_set_write_fn(...).
- */
-#include "pngpriv.h"
-
-#ifdef PNG_WRITE_SUPPORTED
-
-/* Write the data to whatever output you are using. The default routine
- * writes to a file pointer. Note that this routine sometimes gets called
- * with very small lengths, so you should implement some kind of simple
- * buffering if you are using unbuffered writes. This should never be asked
- * to write more than 64K on a 16 bit machine.
- */
-
-void /* PRIVATE */
-png_write_data(png_structrp png_ptr, png_const_bytep data, png_size_t length)
-{
- /* NOTE: write_data_fn must not change the buffer! */
- if (png_ptr->write_data_fn != NULL )
- (*(png_ptr->write_data_fn))(png_ptr, png_constcast(png_bytep,data),
- length);
-
- else
- png_error(png_ptr, "Call to NULL write function");
-}
-
-#ifdef PNG_STDIO_SUPPORTED
-/* This is the function that does the actual writing of data. If you are
- * not writing to a standard C stream, you should create a replacement
- * write_data function and use it at run time with png_set_write_fn(), rather
- * than changing the library.
- */
-void PNGCBAPI
-png_default_write_data(png_structp png_ptr, png_bytep data, png_size_t length)
-{
- png_size_t check;
-
- if (png_ptr == NULL)
- return;
-
- check = fwrite(data, 1, length, (png_FILE_p)(png_ptr->io_ptr));
-
- if (check != length)
- png_error(png_ptr, "Write Error");
-}
-#endif
-
-/* This function is called to output any data pending writing (normally
- * to disk). After png_flush is called, there should be no data pending
- * writing in any buffers.
- */
-#ifdef PNG_WRITE_FLUSH_SUPPORTED
-void /* PRIVATE */
-png_flush(png_structrp png_ptr)
-{
- if (png_ptr->output_flush_fn != NULL)
- (*(png_ptr->output_flush_fn))(png_ptr);
-}
-
-# ifdef PNG_STDIO_SUPPORTED
-void PNGCBAPI
-png_default_flush(png_structp png_ptr)
-{
- png_FILE_p io_ptr;
-
- if (png_ptr == NULL)
- return;
-
- io_ptr = png_voidcast(png_FILE_p, (png_ptr->io_ptr));
- fflush(io_ptr);
-}
-# endif
-#endif
-
-/* This function allows the application to supply new output functions for
- * libpng if standard C streams aren't being used.
- *
- * This function takes as its arguments:
- * png_ptr - pointer to a png output data structure
- * io_ptr - pointer to user supplied structure containing info about
- * the output functions. May be NULL.
- * write_data_fn - pointer to a new output function that takes as its
- * arguments a pointer to a png_struct, a pointer to
- * data to be written, and a 32-bit unsigned int that is
- * the number of bytes to be written. The new write
- * function should call png_error(png_ptr, "Error msg")
- * to exit and output any fatal error messages. May be
- * NULL, in which case libpng's default function will
- * be used.
- * flush_data_fn - pointer to a new flush function that takes as its
- * arguments a pointer to a png_struct. After a call to
- * the flush function, there should be no data in any buffers
- * or pending transmission. If the output method doesn't do
- * any buffering of output, a function prototype must still be
- * supplied although it doesn't have to do anything. If
- * PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile
- * time, output_flush_fn will be ignored, although it must be
- * supplied for compatibility. May be NULL, in which case
- * libpng's default function will be used, if
- * PNG_WRITE_FLUSH_SUPPORTED is defined. This is not
- * a good idea if io_ptr does not point to a standard
- * *FILE structure.
- */
-void PNGAPI
-png_set_write_fn(png_structrp png_ptr, png_voidp io_ptr,
- png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn)
-{
- if (png_ptr == NULL)
- return;
-
- png_ptr->io_ptr = io_ptr;
-
-#ifdef PNG_STDIO_SUPPORTED
- if (write_data_fn != NULL)
- png_ptr->write_data_fn = write_data_fn;
-
- else
- png_ptr->write_data_fn = png_default_write_data;
-#else
- png_ptr->write_data_fn = write_data_fn;
-#endif
-
-#ifdef PNG_WRITE_FLUSH_SUPPORTED
-# ifdef PNG_STDIO_SUPPORTED
-
- if (output_flush_fn != NULL)
- png_ptr->output_flush_fn = output_flush_fn;
-
- else
- png_ptr->output_flush_fn = png_default_flush;
-
-# else
- png_ptr->output_flush_fn = output_flush_fn;
-# endif
-#endif /* PNG_WRITE_FLUSH_SUPPORTED */
-
- /* It is an error to read while writing a png file */
- if (png_ptr->read_data_fn != NULL)
- {
- png_ptr->read_data_fn = NULL;
-
- png_warning(png_ptr,
- "Can't set both read_data_fn and write_data_fn in the"
- " same structure");
- }
-}
-#endif /* PNG_WRITE_SUPPORTED */
+
+/* pngwio.c - functions for data output
+ *
+ * Last changed in libpng 1.6.15 [November 20, 2014]
+ * Copyright (c) 1998-2014 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ * This file provides a location for all output. Users who need
+ * special handling are expected to write functions that have the same
+ * arguments as these and perform similar functions, but that possibly
+ * use different output methods. Note that you shouldn't change these
+ * functions, but rather write replacement functions and then change
+ * them at run time with png_set_write_fn(...).
+ */
+
+#include "pngpriv.h"
+
+#ifdef PNG_WRITE_SUPPORTED
+
+/* Write the data to whatever output you are using. The default routine
+ * writes to a file pointer. Note that this routine sometimes gets called
+ * with very small lengths, so you should implement some kind of simple
+ * buffering if you are using unbuffered writes. This should never be asked
+ * to write more than 64K on a 16-bit machine.
+ */
+
+void /* PRIVATE */
+png_write_data(png_structrp png_ptr, png_const_bytep data, png_size_t length)
+{
+ /* NOTE: write_data_fn must not change the buffer! */
+ if (png_ptr->write_data_fn != NULL )
+ (*(png_ptr->write_data_fn))(png_ptr, png_constcast(png_bytep,data),
+ length);
+
+ else
+ png_error(png_ptr, "Call to NULL write function");
+}
+
+#ifdef PNG_STDIO_SUPPORTED
+/* This is the function that does the actual writing of data. If you are
+ * not writing to a standard C stream, you should create a replacement
+ * write_data function and use it at run time with png_set_write_fn(), rather
+ * than changing the library.
+ */
+void PNGCBAPI
+png_default_write_data(png_structp png_ptr, png_bytep data, png_size_t length)
+{
+ png_size_t check;
+
+ if (png_ptr == NULL)
+ return;
+
+ check = fwrite(data, 1, length, (png_FILE_p)(png_ptr->io_ptr));
+
+ if (check != length)
+ png_error(png_ptr, "Write Error");
+}
+#endif
+
+/* This function is called to output any data pending writing (normally
+ * to disk). After png_flush is called, there should be no data pending
+ * writing in any buffers.
+ */
+#ifdef PNG_WRITE_FLUSH_SUPPORTED
+void /* PRIVATE */
+png_flush(png_structrp png_ptr)
+{
+ if (png_ptr->output_flush_fn != NULL)
+ (*(png_ptr->output_flush_fn))(png_ptr);
+}
+
+# ifdef PNG_STDIO_SUPPORTED
+void PNGCBAPI
+png_default_flush(png_structp png_ptr)
+{
+ png_FILE_p io_ptr;
+
+ if (png_ptr == NULL)
+ return;
+
+ io_ptr = png_voidcast(png_FILE_p, (png_ptr->io_ptr));
+ fflush(io_ptr);
+}
+# endif
+#endif
+
+/* This function allows the application to supply new output functions for
+ * libpng if standard C streams aren't being used.
+ *
+ * This function takes as its arguments:
+ * png_ptr - pointer to a png output data structure
+ * io_ptr - pointer to user supplied structure containing info about
+ * the output functions. May be NULL.
+ * write_data_fn - pointer to a new output function that takes as its
+ * arguments a pointer to a png_struct, a pointer to
+ * data to be written, and a 32-bit unsigned int that is
+ * the number of bytes to be written. The new write
+ * function should call png_error(png_ptr, "Error msg")
+ * to exit and output any fatal error messages. May be
+ * NULL, in which case libpng's default function will
+ * be used.
+ * flush_data_fn - pointer to a new flush function that takes as its
+ * arguments a pointer to a png_struct. After a call to
+ * the flush function, there should be no data in any buffers
+ * or pending transmission. If the output method doesn't do
+ * any buffering of output, a function prototype must still be
+ * supplied although it doesn't have to do anything. If
+ * PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile
+ * time, output_flush_fn will be ignored, although it must be
+ * supplied for compatibility. May be NULL, in which case
+ * libpng's default function will be used, if
+ * PNG_WRITE_FLUSH_SUPPORTED is defined. This is not
+ * a good idea if io_ptr does not point to a standard
+ * *FILE structure.
+ */
+void PNGAPI
+png_set_write_fn(png_structrp png_ptr, png_voidp io_ptr,
+ png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn)
+{
+ if (png_ptr == NULL)
+ return;
+
+ png_ptr->io_ptr = io_ptr;
+
+#ifdef PNG_STDIO_SUPPORTED
+ if (write_data_fn != NULL)
+ png_ptr->write_data_fn = write_data_fn;
+
+ else
+ png_ptr->write_data_fn = png_default_write_data;
+#else
+ png_ptr->write_data_fn = write_data_fn;
+#endif
+
+#ifdef PNG_WRITE_FLUSH_SUPPORTED
+# ifdef PNG_STDIO_SUPPORTED
+
+ if (output_flush_fn != NULL)
+ png_ptr->output_flush_fn = output_flush_fn;
+
+ else
+ png_ptr->output_flush_fn = png_default_flush;
+
+# else
+ png_ptr->output_flush_fn = output_flush_fn;
+# endif
+#else
+ PNG_UNUSED(output_flush_fn)
+#endif /* WRITE_FLUSH */
+
+#ifdef PNG_READ_SUPPORTED
+ /* It is an error to read while writing a png file */
+ if (png_ptr->read_data_fn != NULL)
+ {
+ png_ptr->read_data_fn = NULL;
+
+ png_warning(png_ptr,
+ "Can't set both read_data_fn and write_data_fn in the"
+ " same structure");
+ }
+#endif
+}
+#endif /* WRITE */
diff --git a/third_party/lpng_v163/pngwrite.c b/third_party/libpng/pngwrite.c
similarity index 74%
rename from third_party/lpng_v163/pngwrite.c
rename to third_party/libpng/pngwrite.c
index f48ed97..0d4ee9f 100644
--- a/third_party/lpng_v163/pngwrite.c
+++ b/third_party/libpng/pngwrite.c
@@ -1,2329 +1,2230 @@
-
-/* pngwrite.c - general routines to write a PNG file
- *
- * Last changed in libpng 1.6.2 [April 25, 2013]
- * Copyright (c) 1998-2013 Glenn Randers-Pehrson
- * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
- * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
- *
- * This code is released under the libpng license.
- * For conditions of distribution and use, see the disclaimer
- * and license in png.h
- */
-#include "pngpriv.h"
-#if defined(PNG_SIMPLIFIED_WRITE_SUPPORTED) && defined(PNG_STDIO_SUPPORTED)
-# include <errno.h>
-#endif
-
-#ifdef PNG_WRITE_SUPPORTED
-
-#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
-/* Write out all the unknown chunks for the current given location */
-static void
-write_unknown_chunks(png_structrp png_ptr, png_const_inforp info_ptr,
- unsigned int where)
-{
- if (info_ptr->unknown_chunks_num)
- {
- png_const_unknown_chunkp up;
-
- png_debug(5, "writing extra chunks");
-
- for (up = info_ptr->unknown_chunks;
- up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
- ++up)
- if (up->location & where)
- {
- /* If per-chunk unknown chunk handling is enabled use it, otherwise
- * just write the chunks the application has set.
- */
-#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
- int keep = png_handle_as_unknown(png_ptr, up->name);
-
- /* NOTE: this code is radically different from the read side in the
- * matter of handling an ancillary unknown chunk. In the read side
- * the default behavior is to discard it, in the code below the default
- * behavior is to write it. Critical chunks are, however, only
- * written if explicitly listed or if the default is set to write all
- * unknown chunks.
- *
- * The default handling is also slightly weird - it is not possible to
- * stop the writing of all unsafe-to-copy chunks!
- *
- * TODO: REVIEW: this would seem to be a bug.
- */
- if (keep != PNG_HANDLE_CHUNK_NEVER &&
- ((up->name[3] & 0x20) /* safe-to-copy overrides everything */ ||
- keep == PNG_HANDLE_CHUNK_ALWAYS ||
- (keep == PNG_HANDLE_CHUNK_AS_DEFAULT &&
- png_ptr->unknown_default == PNG_HANDLE_CHUNK_ALWAYS)))
-#endif
- {
- /* TODO: review, what is wrong with a zero length unknown chunk? */
- if (up->size == 0)
- png_warning(png_ptr, "Writing zero-length unknown chunk");
-
- png_write_chunk(png_ptr, up->name, up->data, up->size);
- }
- }
- }
-}
-#endif /* PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED */
-
-/* Writes all the PNG information. This is the suggested way to use the
- * library. If you have a new chunk to add, make a function to write it,
- * and put it in the correct location here. If you want the chunk written
- * after the image data, put it in png_write_end(). I strongly encourage
- * you to supply a PNG_INFO_ flag, and check info_ptr->valid before writing
- * the chunk, as that will keep the code from breaking if you want to just
- * write a plain PNG file. If you have long comments, I suggest writing
- * them in png_write_end(), and compressing them.
- */
-void PNGAPI
-png_write_info_before_PLTE(png_structrp png_ptr, png_const_inforp info_ptr)
-{
- png_debug(1, "in png_write_info_before_PLTE");
-
- if (png_ptr == NULL || info_ptr == NULL)
- return;
-
- if (!(png_ptr->mode & PNG_WROTE_INFO_BEFORE_PLTE))
- {
- /* Write PNG signature */
- png_write_sig(png_ptr);
-
-#ifdef PNG_MNG_FEATURES_SUPPORTED
- if ((png_ptr->mode&PNG_HAVE_PNG_SIGNATURE) && \
- (png_ptr->mng_features_permitted))
- {
- png_warning(png_ptr, "MNG features are not allowed in a PNG datastream");
- png_ptr->mng_features_permitted = 0;
- }
-#endif
-
- /* Write IHDR information. */
- png_write_IHDR(png_ptr, info_ptr->width, info_ptr->height,
- info_ptr->bit_depth, info_ptr->color_type, info_ptr->compression_type,
- info_ptr->filter_type,
-#ifdef PNG_WRITE_INTERLACING_SUPPORTED
- info_ptr->interlace_type
-#else
- 0
-#endif
- );
-
- /* The rest of these check to see if the valid field has the appropriate
- * flag set, and if it does, writes the chunk.
- *
- * 1.6.0: COLORSPACE support controls the writing of these chunks too, and
- * the chunks will be written if the WRITE routine is there and information
- * is available in the COLORSPACE. (See png_colorspace_sync_info in png.c
- * for where the valid flags get set.)
- *
- * Under certain circumstances the colorspace can be invalidated without
- * syncing the info_struct 'valid' flags; this happens if libpng detects and
- * error and calls png_error while the color space is being set, yet the
- * application continues writing the PNG. So check the 'invalid' flag here
- * too.
- */
-#ifdef PNG_GAMMA_SUPPORTED
-# ifdef PNG_WRITE_gAMA_SUPPORTED
- if (!(info_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) &&
- (info_ptr->colorspace.flags & PNG_COLORSPACE_FROM_gAMA) &&
- (info_ptr->valid & PNG_INFO_gAMA))
- png_write_gAMA_fixed(png_ptr, info_ptr->colorspace.gamma);
-# endif
-#endif
-
-#ifdef PNG_COLORSPACE_SUPPORTED
- /* Write only one of sRGB or an ICC profile. If a profile was supplied
- * and it matches one of the known sRGB ones issue a warning.
- */
-# ifdef PNG_WRITE_iCCP_SUPPORTED
- if (!(info_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) &&
- (info_ptr->valid & PNG_INFO_iCCP))
- {
-# ifdef PNG_WRITE_sRGB_SUPPORTED
- if (info_ptr->valid & PNG_INFO_sRGB)
- png_app_warning(png_ptr,
- "profile matches sRGB but writing iCCP instead");
-# endif
-
- png_write_iCCP(png_ptr, info_ptr->iccp_name,
- info_ptr->iccp_profile);
- }
-# ifdef PNG_WRITE_sRGB_SUPPORTED
- else
-# endif
-# endif
-
-# ifdef PNG_WRITE_sRGB_SUPPORTED
- if (!(info_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) &&
- (info_ptr->valid & PNG_INFO_sRGB))
- png_write_sRGB(png_ptr, info_ptr->colorspace.rendering_intent);
-# endif /* WRITE_sRGB */
-#endif /* COLORSPACE */
-
-#ifdef PNG_WRITE_sBIT_SUPPORTED
- if (info_ptr->valid & PNG_INFO_sBIT)
- png_write_sBIT(png_ptr, &(info_ptr->sig_bit), info_ptr->color_type);
-#endif
-
-#ifdef PNG_COLORSPACE_SUPPORTED
-# ifdef PNG_WRITE_cHRM_SUPPORTED
- if (!(info_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) &&
- (info_ptr->colorspace.flags & PNG_COLORSPACE_FROM_cHRM) &&
- (info_ptr->valid & PNG_INFO_cHRM))
- png_write_cHRM_fixed(png_ptr, &info_ptr->colorspace.end_points_xy);
-# endif
-#endif
-
-#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
- write_unknown_chunks(png_ptr, info_ptr, PNG_HAVE_IHDR);
-#endif
-
- png_ptr->mode |= PNG_WROTE_INFO_BEFORE_PLTE;
- }
-}
-
-void PNGAPI
-png_write_info(png_structrp png_ptr, png_const_inforp info_ptr)
-{
-#if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED)
- int i;
-#endif
-
- png_debug(1, "in png_write_info");
-
- if (png_ptr == NULL || info_ptr == NULL)
- return;
-
- png_write_info_before_PLTE(png_ptr, info_ptr);
-
- if (info_ptr->valid & PNG_INFO_PLTE)
- png_write_PLTE(png_ptr, info_ptr->palette,
- (png_uint_32)info_ptr->num_palette);
-
- else if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
- png_error(png_ptr, "Valid palette required for paletted images");
-
-#ifdef PNG_WRITE_tRNS_SUPPORTED
- if (info_ptr->valid & PNG_INFO_tRNS)
- {
-#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
- /* Invert the alpha channel (in tRNS) */
- if ((png_ptr->transformations & PNG_INVERT_ALPHA) &&
- info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
- {
- int j;
- for (j = 0; j<(int)info_ptr->num_trans; j++)
- info_ptr->trans_alpha[j] =
- (png_byte)(255 - info_ptr->trans_alpha[j]);
- }
-#endif
- png_write_tRNS(png_ptr, info_ptr->trans_alpha, &(info_ptr->trans_color),
- info_ptr->num_trans, info_ptr->color_type);
- }
-#endif
-#ifdef PNG_WRITE_bKGD_SUPPORTED
- if (info_ptr->valid & PNG_INFO_bKGD)
- png_write_bKGD(png_ptr, &(info_ptr->background), info_ptr->color_type);
-#endif
-
-#ifdef PNG_WRITE_hIST_SUPPORTED
- if (info_ptr->valid & PNG_INFO_hIST)
- png_write_hIST(png_ptr, info_ptr->hist, info_ptr->num_palette);
-#endif
-
-#ifdef PNG_WRITE_oFFs_SUPPORTED
- if (info_ptr->valid & PNG_INFO_oFFs)
- png_write_oFFs(png_ptr, info_ptr->x_offset, info_ptr->y_offset,
- info_ptr->offset_unit_type);
-#endif
-
-#ifdef PNG_WRITE_pCAL_SUPPORTED
- if (info_ptr->valid & PNG_INFO_pCAL)
- png_write_pCAL(png_ptr, info_ptr->pcal_purpose, info_ptr->pcal_X0,
- info_ptr->pcal_X1, info_ptr->pcal_type, info_ptr->pcal_nparams,
- info_ptr->pcal_units, info_ptr->pcal_params);
-#endif
-
-#ifdef PNG_WRITE_sCAL_SUPPORTED
- if (info_ptr->valid & PNG_INFO_sCAL)
- png_write_sCAL_s(png_ptr, (int)info_ptr->scal_unit,
- info_ptr->scal_s_width, info_ptr->scal_s_height);
-#endif /* sCAL */
-
-#ifdef PNG_WRITE_pHYs_SUPPORTED
- if (info_ptr->valid & PNG_INFO_pHYs)
- png_write_pHYs(png_ptr, info_ptr->x_pixels_per_unit,
- info_ptr->y_pixels_per_unit, info_ptr->phys_unit_type);
-#endif /* pHYs */
-
-#ifdef PNG_WRITE_tIME_SUPPORTED
- if (info_ptr->valid & PNG_INFO_tIME)
- {
- png_write_tIME(png_ptr, &(info_ptr->mod_time));
- png_ptr->mode |= PNG_WROTE_tIME;
- }
-#endif /* tIME */
-
-#ifdef PNG_WRITE_sPLT_SUPPORTED
- if (info_ptr->valid & PNG_INFO_sPLT)
- for (i = 0; i < (int)info_ptr->splt_palettes_num; i++)
- png_write_sPLT(png_ptr, info_ptr->splt_palettes + i);
-#endif /* sPLT */
-
-#ifdef PNG_WRITE_TEXT_SUPPORTED
- /* Check to see if we need to write text chunks */
- for (i = 0; i < info_ptr->num_text; i++)
- {
- png_debug2(2, "Writing header text chunk %d, type %d", i,
- info_ptr->text[i].compression);
- /* An internationalized chunk? */
- if (info_ptr->text[i].compression > 0)
- {
-#ifdef PNG_WRITE_iTXt_SUPPORTED
- /* Write international chunk */
- png_write_iTXt(png_ptr,
- info_ptr->text[i].compression,
- info_ptr->text[i].key,
- info_ptr->text[i].lang,
- info_ptr->text[i].lang_key,
- info_ptr->text[i].text);
-#else
- png_warning(png_ptr, "Unable to write international text");
-#endif
- /* Mark this chunk as written */
- info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
- }
-
- /* If we want a compressed text chunk */
- else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_zTXt)
- {
-#ifdef PNG_WRITE_zTXt_SUPPORTED
- /* Write compressed chunk */
- png_write_zTXt(png_ptr, info_ptr->text[i].key,
- info_ptr->text[i].text, 0,
- info_ptr->text[i].compression);
-#else
- png_warning(png_ptr, "Unable to write compressed text");
-#endif
- /* Mark this chunk as written */
- info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR;
- }
-
- else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE)
- {
-#ifdef PNG_WRITE_tEXt_SUPPORTED
- /* Write uncompressed chunk */
- png_write_tEXt(png_ptr, info_ptr->text[i].key,
- info_ptr->text[i].text,
- 0);
- /* Mark this chunk as written */
- info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
-#else
- /* Can't get here */
- png_warning(png_ptr, "Unable to write uncompressed text");
-#endif
- }
- }
-#endif /* tEXt */
-
-#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
- write_unknown_chunks(png_ptr, info_ptr, PNG_HAVE_PLTE);
-#endif
-}
-
-/* Writes the end of the PNG file. If you don't want to write comments or
- * time information, you can pass NULL for info. If you already wrote these
- * in png_write_info(), do not write them again here. If you have long
- * comments, I suggest writing them here, and compressing them.
- */
-void PNGAPI
-png_write_end(png_structrp png_ptr, png_inforp info_ptr)
-{
- png_debug(1, "in png_write_end");
-
- if (png_ptr == NULL)
- return;
-
- if (!(png_ptr->mode & PNG_HAVE_IDAT))
- png_error(png_ptr, "No IDATs written into file");
-
-#ifdef PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED
- if (png_ptr->num_palette_max > png_ptr->num_palette)
- png_benign_error(png_ptr, "Wrote palette index exceeding num_palette");
-#endif
-
- /* See if user wants us to write information chunks */
- if (info_ptr != NULL)
- {
-#ifdef PNG_WRITE_TEXT_SUPPORTED
- int i; /* local index variable */
-#endif
-#ifdef PNG_WRITE_tIME_SUPPORTED
- /* Check to see if user has supplied a time chunk */
- if ((info_ptr->valid & PNG_INFO_tIME) &&
- !(png_ptr->mode & PNG_WROTE_tIME))
- png_write_tIME(png_ptr, &(info_ptr->mod_time));
-
-#endif
-#ifdef PNG_WRITE_TEXT_SUPPORTED
- /* Loop through comment chunks */
- for (i = 0; i < info_ptr->num_text; i++)
- {
- png_debug2(2, "Writing trailer text chunk %d, type %d", i,
- info_ptr->text[i].compression);
- /* An internationalized chunk? */
- if (info_ptr->text[i].compression > 0)
- {
-#ifdef PNG_WRITE_iTXt_SUPPORTED
- /* Write international chunk */
- png_write_iTXt(png_ptr,
- info_ptr->text[i].compression,
- info_ptr->text[i].key,
- info_ptr->text[i].lang,
- info_ptr->text[i].lang_key,
- info_ptr->text[i].text);
-#else
- png_warning(png_ptr, "Unable to write international text");
-#endif
- /* Mark this chunk as written */
- info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
- }
-
- else if (info_ptr->text[i].compression >= PNG_TEXT_COMPRESSION_zTXt)
- {
-#ifdef PNG_WRITE_zTXt_SUPPORTED
- /* Write compressed chunk */
- png_write_zTXt(png_ptr, info_ptr->text[i].key,
- info_ptr->text[i].text, 0,
- info_ptr->text[i].compression);
-#else
- png_warning(png_ptr, "Unable to write compressed text");
-#endif
- /* Mark this chunk as written */
- info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR;
- }
-
- else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE)
- {
-#ifdef PNG_WRITE_tEXt_SUPPORTED
- /* Write uncompressed chunk */
- png_write_tEXt(png_ptr, info_ptr->text[i].key,
- info_ptr->text[i].text, 0);
-#else
- png_warning(png_ptr, "Unable to write uncompressed text");
-#endif
-
- /* Mark this chunk as written */
- info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
- }
- }
-#endif
-#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
- write_unknown_chunks(png_ptr, info_ptr, PNG_AFTER_IDAT);
-#endif
- }
-
- png_ptr->mode |= PNG_AFTER_IDAT;
-
- /* Write end of PNG file */
- png_write_IEND(png_ptr);
- /* This flush, added in libpng-1.0.8, removed from libpng-1.0.9beta03,
- * and restored again in libpng-1.2.30, may cause some applications that
- * do not set png_ptr->output_flush_fn to crash. If your application
- * experiences a problem, please try building libpng with
- * PNG_WRITE_FLUSH_AFTER_IEND_SUPPORTED defined, and report the event to
- * png-mng-implement at lists.sf.net .
- */
-#ifdef PNG_WRITE_FLUSH_SUPPORTED
-# ifdef PNG_WRITE_FLUSH_AFTER_IEND_SUPPORTED
- png_flush(png_ptr);
-# endif
-#endif
-}
-
-#ifdef PNG_CONVERT_tIME_SUPPORTED
-void PNGAPI
-png_convert_from_struct_tm(png_timep ptime, PNG_CONST struct tm * ttime)
-{
- png_debug(1, "in png_convert_from_struct_tm");
-
- ptime->year = (png_uint_16)(1900 + ttime->tm_year);
- ptime->month = (png_byte)(ttime->tm_mon + 1);
- ptime->day = (png_byte)ttime->tm_mday;
- ptime->hour = (png_byte)ttime->tm_hour;
- ptime->minute = (png_byte)ttime->tm_min;
- ptime->second = (png_byte)ttime->tm_sec;
-}
-
-void PNGAPI
-png_convert_from_time_t(png_timep ptime, time_t ttime)
-{
- struct tm *tbuf;
-
- png_debug(1, "in png_convert_from_time_t");
-
- tbuf = gmtime(&ttime);
- png_convert_from_struct_tm(ptime, tbuf);
-}
-#endif
-
-/* Initialize png_ptr structure, and allocate any memory needed */
-PNG_FUNCTION(png_structp,PNGAPI
-png_create_write_struct,(png_const_charp user_png_ver, png_voidp error_ptr,
- png_error_ptr error_fn, png_error_ptr warn_fn),PNG_ALLOCATED)
-{
-#ifndef PNG_USER_MEM_SUPPORTED
- png_structrp png_ptr = png_create_png_struct(user_png_ver, error_ptr,
- error_fn, warn_fn, NULL, NULL, NULL);
-#else
- return png_create_write_struct_2(user_png_ver, error_ptr, error_fn,
- warn_fn, NULL, NULL, NULL);
-}
-
-/* Alternate initialize png_ptr structure, and allocate any memory needed */
-PNG_FUNCTION(png_structp,PNGAPI
-png_create_write_struct_2,(png_const_charp user_png_ver, png_voidp error_ptr,
- png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
- png_malloc_ptr malloc_fn, png_free_ptr free_fn),PNG_ALLOCATED)
-{
- png_structrp png_ptr = png_create_png_struct(user_png_ver, error_ptr,
- error_fn, warn_fn, mem_ptr, malloc_fn, free_fn);
-#endif /* PNG_USER_MEM_SUPPORTED */
- if (png_ptr != NULL)
- {
- /* Set the zlib control values to defaults; they can be overridden by the
- * application after the struct has been created.
- */
- png_ptr->zbuffer_size = PNG_ZBUF_SIZE;
-
- /* The 'zlib_strategy' setting is irrelevant because png_default_claim in
- * pngwutil.c defaults it according to whether or not filters will be
- * used, and ignores this setting.
- */
- png_ptr->zlib_strategy = PNG_Z_DEFAULT_STRATEGY;
- png_ptr->zlib_level = PNG_Z_DEFAULT_COMPRESSION;
- png_ptr->zlib_mem_level = 8;
- png_ptr->zlib_window_bits = 15;
- png_ptr->zlib_method = 8;
-
-#ifdef PNG_WRITE_COMPRESSED_TEXT_SUPPORTED
- png_ptr->zlib_text_strategy = PNG_TEXT_Z_DEFAULT_STRATEGY;
- png_ptr->zlib_text_level = PNG_TEXT_Z_DEFAULT_COMPRESSION;
- png_ptr->zlib_text_mem_level = 8;
- png_ptr->zlib_text_window_bits = 15;
- png_ptr->zlib_text_method = 8;
-#endif /* PNG_WRITE_COMPRESSED_TEXT_SUPPORTED */
-
- /* This is a highly dubious configuration option; by default it is off,
- * but it may be appropriate for private builds that are testing
- * extensions not conformant to the current specification, or of
- * applications that must not fail to write at all costs!
- */
-#ifdef PNG_BENIGN_WRITE_ERRORS_SUPPORTED
- png_ptr->flags |= PNG_FLAG_BENIGN_ERRORS_WARN;
- /* In stable builds only warn if an application error can be completely
- * handled.
- */
-#endif
-
- /* App warnings are warnings in release (or release candidate) builds but
- * are errors during development.
- */
-#if PNG_LIBPNG_BUILD_BASE_TYPE >= PNG_LIBPNG_BUILD_RC
- png_ptr->flags |= PNG_FLAG_APP_WARNINGS_WARN;
-#endif
-
- /* TODO: delay this, it can be done in png_init_io() (if the app doesn't
- * do it itself) avoiding setting the default function if it is not
- * required.
- */
- png_set_write_fn(png_ptr, NULL, NULL, NULL);
- }
-
- return png_ptr;
-}
-
-
-/* Write a few rows of image data. If the image is interlaced,
- * either you will have to write the 7 sub images, or, if you
- * have called png_set_interlace_handling(), you will have to
- * "write" the image seven times.
- */
-void PNGAPI
-png_write_rows(png_structrp png_ptr, png_bytepp row,
- png_uint_32 num_rows)
-{
- png_uint_32 i; /* row counter */
- png_bytepp rp; /* row pointer */
-
- png_debug(1, "in png_write_rows");
-
- if (png_ptr == NULL)
- return;
-
- /* Loop through the rows */
- for (i = 0, rp = row; i < num_rows; i++, rp++)
- {
- png_write_row(png_ptr, *rp);
- }
-}
-
-/* Write the image. You only need to call this function once, even
- * if you are writing an interlaced image.
- */
-void PNGAPI
-png_write_image(png_structrp png_ptr, png_bytepp image)
-{
- png_uint_32 i; /* row index */
- int pass, num_pass; /* pass variables */
- png_bytepp rp; /* points to current row */
-
- if (png_ptr == NULL)
- return;
-
- png_debug(1, "in png_write_image");
-
-#ifdef PNG_WRITE_INTERLACING_SUPPORTED
- /* Initialize interlace handling. If image is not interlaced,
- * this will set pass to 1
- */
- num_pass = png_set_interlace_handling(png_ptr);
-#else
- num_pass = 1;
-#endif
- /* Loop through passes */
- for (pass = 0; pass < num_pass; pass++)
- {
- /* Loop through image */
- for (i = 0, rp = image; i < png_ptr->height; i++, rp++)
- {
- png_write_row(png_ptr, *rp);
- }
- }
-}
-
-/* Called by user to write a row of image data */
-void PNGAPI
-png_write_row(png_structrp png_ptr, png_const_bytep row)
-{
- /* 1.5.6: moved from png_struct to be a local structure: */
- png_row_info row_info;
-
- if (png_ptr == NULL)
- return;
-
- png_debug2(1, "in png_write_row (row %u, pass %d)",
- png_ptr->row_number, png_ptr->pass);
-
- /* Initialize transformations and other stuff if first time */
- if (png_ptr->row_number == 0 && png_ptr->pass == 0)
- {
- /* Make sure we wrote the header info */
- if (!(png_ptr->mode & PNG_WROTE_INFO_BEFORE_PLTE))
- png_error(png_ptr,
- "png_write_info was never called before png_write_row");
-
- /* Check for transforms that have been set but were defined out */
-#if !defined(PNG_WRITE_INVERT_SUPPORTED) && defined(PNG_READ_INVERT_SUPPORTED)
- if (png_ptr->transformations & PNG_INVERT_MONO)
- png_warning(png_ptr, "PNG_WRITE_INVERT_SUPPORTED is not defined");
-#endif
-
-#if !defined(PNG_WRITE_FILLER_SUPPORTED) && defined(PNG_READ_FILLER_SUPPORTED)
- if (png_ptr->transformations & PNG_FILLER)
- png_warning(png_ptr, "PNG_WRITE_FILLER_SUPPORTED is not defined");
-#endif
-#if !defined(PNG_WRITE_PACKSWAP_SUPPORTED) && \
- defined(PNG_READ_PACKSWAP_SUPPORTED)
- if (png_ptr->transformations & PNG_PACKSWAP)
- png_warning(png_ptr,
- "PNG_WRITE_PACKSWAP_SUPPORTED is not defined");
-#endif
-
-#if !defined(PNG_WRITE_PACK_SUPPORTED) && defined(PNG_READ_PACK_SUPPORTED)
- if (png_ptr->transformations & PNG_PACK)
- png_warning(png_ptr, "PNG_WRITE_PACK_SUPPORTED is not defined");
-#endif
-
-#if !defined(PNG_WRITE_SHIFT_SUPPORTED) && defined(PNG_READ_SHIFT_SUPPORTED)
- if (png_ptr->transformations & PNG_SHIFT)
- png_warning(png_ptr, "PNG_WRITE_SHIFT_SUPPORTED is not defined");
-#endif
-
-#if !defined(PNG_WRITE_BGR_SUPPORTED) && defined(PNG_READ_BGR_SUPPORTED)
- if (png_ptr->transformations & PNG_BGR)
- png_warning(png_ptr, "PNG_WRITE_BGR_SUPPORTED is not defined");
-#endif
-
-#if !defined(PNG_WRITE_SWAP_SUPPORTED) && defined(PNG_READ_SWAP_SUPPORTED)
- if (png_ptr->transformations & PNG_SWAP_BYTES)
- png_warning(png_ptr, "PNG_WRITE_SWAP_SUPPORTED is not defined");
-#endif
-
- png_write_start_row(png_ptr);
- }
-
-#ifdef PNG_WRITE_INTERLACING_SUPPORTED
- /* If interlaced and not interested in row, return */
- if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE))
- {
- switch (png_ptr->pass)
- {
- case 0:
- if (png_ptr->row_number & 0x07)
- {
- png_write_finish_row(png_ptr);
- return;
- }
- break;
-
- case 1:
- if ((png_ptr->row_number & 0x07) || png_ptr->width < 5)
- {
- png_write_finish_row(png_ptr);
- return;
- }
- break;
-
- case 2:
- if ((png_ptr->row_number & 0x07) != 4)
- {
- png_write_finish_row(png_ptr);
- return;
- }
- break;
-
- case 3:
- if ((png_ptr->row_number & 0x03) || png_ptr->width < 3)
- {
- png_write_finish_row(png_ptr);
- return;
- }
- break;
-
- case 4:
- if ((png_ptr->row_number & 0x03) != 2)
- {
- png_write_finish_row(png_ptr);
- return;
- }
- break;
-
- case 5:
- if ((png_ptr->row_number & 0x01) || png_ptr->width < 2)
- {
- png_write_finish_row(png_ptr);
- return;
- }
- break;
-
- case 6:
- if (!(png_ptr->row_number & 0x01))
- {
- png_write_finish_row(png_ptr);
- return;
- }
- break;
-
- default: /* error: ignore it */
- break;
- }
- }
-#endif
-
- /* Set up row info for transformations */
- row_info.color_type = png_ptr->color_type;
- row_info.width = png_ptr->usr_width;
- row_info.channels = png_ptr->usr_channels;
- row_info.bit_depth = png_ptr->usr_bit_depth;
- row_info.pixel_depth = (png_byte)(row_info.bit_depth * row_info.channels);
- row_info.rowbytes = PNG_ROWBYTES(row_info.pixel_depth, row_info.width);
-
- png_debug1(3, "row_info->color_type = %d", row_info.color_type);
- png_debug1(3, "row_info->width = %u", row_info.width);
- png_debug1(3, "row_info->channels = %d", row_info.channels);
- png_debug1(3, "row_info->bit_depth = %d", row_info.bit_depth);
- png_debug1(3, "row_info->pixel_depth = %d", row_info.pixel_depth);
- png_debug1(3, "row_info->rowbytes = %lu", (unsigned long)row_info.rowbytes);
-
- /* Copy user's row into buffer, leaving room for filter byte. */
- memcpy(png_ptr->row_buf + 1, row, row_info.rowbytes);
-
-#ifdef PNG_WRITE_INTERLACING_SUPPORTED
- /* Handle interlacing */
- if (png_ptr->interlaced && png_ptr->pass < 6 &&
- (png_ptr->transformations & PNG_INTERLACE))
- {
- png_do_write_interlace(&row_info, png_ptr->row_buf + 1, png_ptr->pass);
- /* This should always get caught above, but still ... */
- if (!(row_info.width))
- {
- png_write_finish_row(png_ptr);
- return;
- }
- }
-#endif
-
-#ifdef PNG_WRITE_TRANSFORMS_SUPPORTED
- /* Handle other transformations */
- if (png_ptr->transformations)
- png_do_write_transformations(png_ptr, &row_info);
-#endif
-
- /* At this point the row_info pixel depth must match the 'transformed' depth,
- * which is also the output depth.
- */
- if (row_info.pixel_depth != png_ptr->pixel_depth ||
- row_info.pixel_depth != png_ptr->transformed_pixel_depth)
- png_error(png_ptr, "internal write transform logic error");
-
-#ifdef PNG_MNG_FEATURES_SUPPORTED
- /* Write filter_method 64 (intrapixel differencing) only if
- * 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and
- * 2. Libpng did not write a PNG signature (this filter_method is only
- * used in PNG datastreams that are embedded in MNG datastreams) and
- * 3. The application called png_permit_mng_features with a mask that
- * included PNG_FLAG_MNG_FILTER_64 and
- * 4. The filter_method is 64 and
- * 5. The color_type is RGB or RGBA
- */
- if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
- (png_ptr->filter_type == PNG_INTRAPIXEL_DIFFERENCING))
- {
- /* Intrapixel differencing */
- png_do_write_intrapixel(&row_info, png_ptr->row_buf + 1);
- }
-#endif
-
-/* Added at libpng-1.5.10 */
-#ifdef PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED
- /* Check for out-of-range palette index */
- if (row_info.color_type == PNG_COLOR_TYPE_PALETTE &&
- png_ptr->num_palette_max >= 0)
- png_do_check_palette_indexes(png_ptr, &row_info);
-#endif
-
- /* Find a filter if necessary, filter the row and write it out. */
- png_write_find_filter(png_ptr, &row_info);
-
- if (png_ptr->write_row_fn != NULL)
- (*(png_ptr->write_row_fn))(png_ptr, png_ptr->row_number, png_ptr->pass);
-}
-
-#ifdef PNG_WRITE_FLUSH_SUPPORTED
-/* Set the automatic flush interval or 0 to turn flushing off */
-void PNGAPI
-png_set_flush(png_structrp png_ptr, int nrows)
-{
- png_debug(1, "in png_set_flush");
-
- if (png_ptr == NULL)
- return;
-
- png_ptr->flush_dist = (nrows < 0 ? 0 : nrows);
-}
-
-/* Flush the current output buffers now */
-void PNGAPI
-png_write_flush(png_structrp png_ptr)
-{
- png_debug(1, "in png_write_flush");
-
- if (png_ptr == NULL)
- return;
-
- /* We have already written out all of the data */
- if (png_ptr->row_number >= png_ptr->num_rows)
- return;
-
- png_compress_IDAT(png_ptr, NULL, 0, Z_SYNC_FLUSH);
- png_ptr->flush_rows = 0;
- png_flush(png_ptr);
-}
-#endif /* PNG_WRITE_FLUSH_SUPPORTED */
-
-#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
-static void png_reset_filter_heuristics(png_structrp png_ptr);/* forward decl */
-#endif
-
-/* Free any memory used in png_ptr struct without freeing the struct itself. */
-static void
-png_write_destroy(png_structrp png_ptr)
-{
- png_debug(1, "in png_write_destroy");
-
- /* Free any memory zlib uses */
- if (png_ptr->flags & PNG_FLAG_ZSTREAM_INITIALIZED)
- deflateEnd(&png_ptr->zstream);
-
- /* Free our memory. png_free checks NULL for us. */
- png_free_buffer_list(png_ptr, &png_ptr->zbuffer_list);
- png_free(png_ptr, png_ptr->row_buf);
-#ifdef PNG_WRITE_FILTER_SUPPORTED
- png_free(png_ptr, png_ptr->prev_row);
- png_free(png_ptr, png_ptr->sub_row);
- png_free(png_ptr, png_ptr->up_row);
- png_free(png_ptr, png_ptr->avg_row);
- png_free(png_ptr, png_ptr->paeth_row);
-#endif
-
-#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
- /* Use this to save a little code space, it doesn't free the filter_costs */
- png_reset_filter_heuristics(png_ptr);
- png_free(png_ptr, png_ptr->filter_costs);
- png_free(png_ptr, png_ptr->inv_filter_costs);
-#endif
-
-#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
- png_free(png_ptr, png_ptr->chunk_list);
-#endif
-
- /* The error handling and memory handling information is left intact at this
- * point: the jmp_buf may still have to be freed. See png_destroy_png_struct
- * for how this happens.
- */
-}
-
-/* Free all memory used by the write.
- * In libpng 1.6.0 this API changed quietly to no longer accept a NULL value for
- * *png_ptr_ptr. Prior to 1.6.0 it would accept such a value and it would free
- * the passed in info_structs but it would quietly fail to free any of the data
- * inside them. In 1.6.0 it quietly does nothing (it has to be quiet because it
- * has no png_ptr.)
- */
-void PNGAPI
-png_destroy_write_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr)
-{
- png_debug(1, "in png_destroy_write_struct");
-
- if (png_ptr_ptr != NULL)
- {
- png_structrp png_ptr = *png_ptr_ptr;
-
- if (png_ptr != NULL) /* added in libpng 1.6.0 */
- {
- png_destroy_info_struct(png_ptr, info_ptr_ptr);
-
- *png_ptr_ptr = NULL;
- png_write_destroy(png_ptr);
- png_destroy_png_struct(png_ptr);
- }
- }
-}
-
-/* Allow the application to select one or more row filters to use. */
-void PNGAPI
-png_set_filter(png_structrp png_ptr, int method, int filters)
-{
- png_debug(1, "in png_set_filter");
-
- if (png_ptr == NULL)
- return;
-
-#ifdef PNG_MNG_FEATURES_SUPPORTED
- if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
- (method == PNG_INTRAPIXEL_DIFFERENCING))
- method = PNG_FILTER_TYPE_BASE;
-
-#endif
- if (method == PNG_FILTER_TYPE_BASE)
- {
- switch (filters & (PNG_ALL_FILTERS | 0x07))
- {
-#ifdef PNG_WRITE_FILTER_SUPPORTED
- case 5:
- case 6:
- case 7: png_app_error(png_ptr, "Unknown row filter for method 0");
- /* FALL THROUGH */
-#endif /* PNG_WRITE_FILTER_SUPPORTED */
- case PNG_FILTER_VALUE_NONE:
- png_ptr->do_filter = PNG_FILTER_NONE; break;
-
-#ifdef PNG_WRITE_FILTER_SUPPORTED
- case PNG_FILTER_VALUE_SUB:
- png_ptr->do_filter = PNG_FILTER_SUB; break;
-
- case PNG_FILTER_VALUE_UP:
- png_ptr->do_filter = PNG_FILTER_UP; break;
-
- case PNG_FILTER_VALUE_AVG:
- png_ptr->do_filter = PNG_FILTER_AVG; break;
-
- case PNG_FILTER_VALUE_PAETH:
- png_ptr->do_filter = PNG_FILTER_PAETH; break;
-
- default:
- png_ptr->do_filter = (png_byte)filters; break;
-#else
- default:
- png_app_error(png_ptr, "Unknown row filter for method 0");
-#endif /* PNG_WRITE_FILTER_SUPPORTED */
- }
-
- /* If we have allocated the row_buf, this means we have already started
- * with the image and we should have allocated all of the filter buffers
- * that have been selected. If prev_row isn't already allocated, then
- * it is too late to start using the filters that need it, since we
- * will be missing the data in the previous row. If an application
- * wants to start and stop using particular filters during compression,
- * it should start out with all of the filters, and then add and
- * remove them after the start of compression.
- */
- if (png_ptr->row_buf != NULL)
- {
-#ifdef PNG_WRITE_FILTER_SUPPORTED
- if ((png_ptr->do_filter & PNG_FILTER_SUB) && png_ptr->sub_row == NULL)
- {
- png_ptr->sub_row = (png_bytep)png_malloc(png_ptr,
- (png_ptr->rowbytes + 1));
- png_ptr->sub_row[0] = PNG_FILTER_VALUE_SUB;
- }
-
- if ((png_ptr->do_filter & PNG_FILTER_UP) && png_ptr->up_row == NULL)
- {
- if (png_ptr->prev_row == NULL)
- {
- png_warning(png_ptr, "Can't add Up filter after starting");
- png_ptr->do_filter = (png_byte)(png_ptr->do_filter &
- ~PNG_FILTER_UP);
- }
-
- else
- {
- png_ptr->up_row = (png_bytep)png_malloc(png_ptr,
- (png_ptr->rowbytes + 1));
- png_ptr->up_row[0] = PNG_FILTER_VALUE_UP;
- }
- }
-
- if ((png_ptr->do_filter & PNG_FILTER_AVG) && png_ptr->avg_row == NULL)
- {
- if (png_ptr->prev_row == NULL)
- {
- png_warning(png_ptr, "Can't add Average filter after starting");
- png_ptr->do_filter = (png_byte)(png_ptr->do_filter &
- ~PNG_FILTER_AVG);
- }
-
- else
- {
- png_ptr->avg_row = (png_bytep)png_malloc(png_ptr,
- (png_ptr->rowbytes + 1));
- png_ptr->avg_row[0] = PNG_FILTER_VALUE_AVG;
- }
- }
-
- if ((png_ptr->do_filter & PNG_FILTER_PAETH) &&
- png_ptr->paeth_row == NULL)
- {
- if (png_ptr->prev_row == NULL)
- {
- png_warning(png_ptr, "Can't add Paeth filter after starting");
- png_ptr->do_filter &= (png_byte)(~PNG_FILTER_PAETH);
- }
-
- else
- {
- png_ptr->paeth_row = (png_bytep)png_malloc(png_ptr,
- (png_ptr->rowbytes + 1));
- png_ptr->paeth_row[0] = PNG_FILTER_VALUE_PAETH;
- }
- }
-
- if (png_ptr->do_filter == PNG_NO_FILTERS)
-#endif /* PNG_WRITE_FILTER_SUPPORTED */
- png_ptr->do_filter = PNG_FILTER_NONE;
- }
- }
- else
- png_error(png_ptr, "Unknown custom filter method");
-}
-
-/* This allows us to influence the way in which libpng chooses the "best"
- * filter for the current scanline. While the "minimum-sum-of-absolute-
- * differences metric is relatively fast and effective, there is some
- * question as to whether it can be improved upon by trying to keep the
- * filtered data going to zlib more consistent, hopefully resulting in
- * better compression.
- */
-#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* GRR 970116 */
-/* Convenience reset API. */
-static void
-png_reset_filter_heuristics(png_structrp png_ptr)
-{
- /* Clear out any old values in the 'weights' - this must be done because if
- * the app calls set_filter_heuristics multiple times with different
- * 'num_weights' values we would otherwise potentially have wrong sized
- * arrays.
- */
- png_ptr->num_prev_filters = 0;
- png_ptr->heuristic_method = PNG_FILTER_HEURISTIC_UNWEIGHTED;
- if (png_ptr->prev_filters != NULL)
- {
- png_bytep old = png_ptr->prev_filters;
- png_ptr->prev_filters = NULL;
- png_free(png_ptr, old);
- }
- if (png_ptr->filter_weights != NULL)
- {
- png_uint_16p old = png_ptr->filter_weights;
- png_ptr->filter_weights = NULL;
- png_free(png_ptr, old);
- }
-
- if (png_ptr->inv_filter_weights != NULL)
- {
- png_uint_16p old = png_ptr->inv_filter_weights;
- png_ptr->inv_filter_weights = NULL;
- png_free(png_ptr, old);
- }
-
- /* Leave the filter_costs - this array is fixed size. */
-}
-
-static int
-png_init_filter_heuristics(png_structrp png_ptr, int heuristic_method,
- int num_weights)
-{
- if (png_ptr == NULL)
- return 0;
-
- /* Clear out the arrays */
- png_reset_filter_heuristics(png_ptr);
-
- /* Check arguments; the 'reset' function makes the correct settings for the
- * unweighted case, but we must handle the weight case by initializing the
- * arrays for the caller.
- */
- if (heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
- {
- int i;
-
- if (num_weights > 0)
- {
- png_ptr->prev_filters = (png_bytep)png_malloc(png_ptr,
- (png_uint_32)((sizeof (png_byte)) * num_weights));
-
- /* To make sure that the weighting starts out fairly */
- for (i = 0; i < num_weights; i++)
- {
- png_ptr->prev_filters[i] = 255;
- }
-
- png_ptr->filter_weights = (png_uint_16p)png_malloc(png_ptr,
- (png_uint_32)((sizeof (png_uint_16)) * num_weights));
-
- png_ptr->inv_filter_weights = (png_uint_16p)png_malloc(png_ptr,
- (png_uint_32)((sizeof (png_uint_16)) * num_weights));
-
- for (i = 0; i < num_weights; i++)
- {
- png_ptr->inv_filter_weights[i] =
- png_ptr->filter_weights[i] = PNG_WEIGHT_FACTOR;
- }
-
- /* Safe to set this now */
- png_ptr->num_prev_filters = (png_byte)num_weights;
- }
-
- /* If, in the future, there are other filter methods, this would
- * need to be based on png_ptr->filter.
- */
- if (png_ptr->filter_costs == NULL)
- {
- png_ptr->filter_costs = (png_uint_16p)png_malloc(png_ptr,
- (png_uint_32)((sizeof (png_uint_16)) * PNG_FILTER_VALUE_LAST));
-
- png_ptr->inv_filter_costs = (png_uint_16p)png_malloc(png_ptr,
- (png_uint_32)((sizeof (png_uint_16)) * PNG_FILTER_VALUE_LAST));
- }
-
- for (i = 0; i < PNG_FILTER_VALUE_LAST; i++)
- {
- png_ptr->inv_filter_costs[i] =
- png_ptr->filter_costs[i] = PNG_COST_FACTOR;
- }
-
- /* All the arrays are inited, safe to set this: */
- png_ptr->heuristic_method = PNG_FILTER_HEURISTIC_WEIGHTED;
-
- /* Return the 'ok' code. */
- return 1;
- }
- else if (heuristic_method == PNG_FILTER_HEURISTIC_DEFAULT ||
- heuristic_method == PNG_FILTER_HEURISTIC_UNWEIGHTED)
- {
- return 1;
- }
- else
- {
- png_warning(png_ptr, "Unknown filter heuristic method");
- return 0;
- }
-}
-
-/* Provide floating and fixed point APIs */
-#ifdef PNG_FLOATING_POINT_SUPPORTED
-void PNGAPI
-png_set_filter_heuristics(png_structrp png_ptr, int heuristic_method,
- int num_weights, png_const_doublep filter_weights,
- png_const_doublep filter_costs)
-{
- png_debug(1, "in png_set_filter_heuristics");
-
- /* The internal API allocates all the arrays and ensures that the elements of
- * those arrays are set to the default value.
- */
- if (!png_init_filter_heuristics(png_ptr, heuristic_method, num_weights))
- return;
-
- /* If using the weighted method copy in the weights. */
- if (heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
- {
- int i;
- for (i = 0; i < num_weights; i++)
- {
- if (filter_weights[i] <= 0.0)
- {
- png_ptr->inv_filter_weights[i] =
- png_ptr->filter_weights[i] = PNG_WEIGHT_FACTOR;
- }
-
- else
- {
- png_ptr->inv_filter_weights[i] =
- (png_uint_16)(PNG_WEIGHT_FACTOR*filter_weights[i]+.5);
-
- png_ptr->filter_weights[i] =
- (png_uint_16)(PNG_WEIGHT_FACTOR/filter_weights[i]+.5);
- }
- }
-
- /* Here is where we set the relative costs of the different filters. We
- * should take the desired compression level into account when setting
- * the costs, so that Paeth, for instance, has a high relative cost at low
- * compression levels, while it has a lower relative cost at higher
- * compression settings. The filter types are in order of increasing
- * relative cost, so it would be possible to do this with an algorithm.
- */
- for (i = 0; i < PNG_FILTER_VALUE_LAST; i++) if (filter_costs[i] >= 1.0)
- {
- png_ptr->inv_filter_costs[i] =
- (png_uint_16)(PNG_COST_FACTOR / filter_costs[i] + .5);
-
- png_ptr->filter_costs[i] =
- (png_uint_16)(PNG_COST_FACTOR * filter_costs[i] + .5);
- }
- }
-}
-#endif /* FLOATING_POINT */
-
-#ifdef PNG_FIXED_POINT_SUPPORTED
-void PNGAPI
-png_set_filter_heuristics_fixed(png_structrp png_ptr, int heuristic_method,
- int num_weights, png_const_fixed_point_p filter_weights,
- png_const_fixed_point_p filter_costs)
-{
- png_debug(1, "in png_set_filter_heuristics_fixed");
-
- /* The internal API allocates all the arrays and ensures that the elements of
- * those arrays are set to the default value.
- */
- if (!png_init_filter_heuristics(png_ptr, heuristic_method, num_weights))
- return;
-
- /* If using the weighted method copy in the weights. */
- if (heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
- {
- int i;
- for (i = 0; i < num_weights; i++)
- {
- if (filter_weights[i] <= 0)
- {
- png_ptr->inv_filter_weights[i] =
- png_ptr->filter_weights[i] = PNG_WEIGHT_FACTOR;
- }
-
- else
- {
- png_ptr->inv_filter_weights[i] = (png_uint_16)
- ((PNG_WEIGHT_FACTOR*filter_weights[i]+PNG_FP_HALF)/PNG_FP_1);
-
- png_ptr->filter_weights[i] = (png_uint_16)((PNG_WEIGHT_FACTOR*
- PNG_FP_1+(filter_weights[i]/2))/filter_weights[i]);
- }
- }
-
- /* Here is where we set the relative costs of the different filters. We
- * should take the desired compression level into account when setting
- * the costs, so that Paeth, for instance, has a high relative cost at low
- * compression levels, while it has a lower relative cost at higher
- * compression settings. The filter types are in order of increasing
- * relative cost, so it would be possible to do this with an algorithm.
- */
- for (i = 0; i < PNG_FILTER_VALUE_LAST; i++)
- if (filter_costs[i] >= PNG_FP_1)
- {
- png_uint_32 tmp;
-
- /* Use a 32 bit unsigned temporary here because otherwise the
- * intermediate value will be a 32 bit *signed* integer (ANSI rules)
- * and this will get the wrong answer on division.
- */
- tmp = PNG_COST_FACTOR*PNG_FP_1 + (filter_costs[i]/2);
- tmp /= filter_costs[i];
-
- png_ptr->inv_filter_costs[i] = (png_uint_16)tmp;
-
- tmp = PNG_COST_FACTOR * filter_costs[i] + PNG_FP_HALF;
- tmp /= PNG_FP_1;
-
- png_ptr->filter_costs[i] = (png_uint_16)tmp;
- }
- }
-}
-#endif /* FIXED_POINT */
-#endif /* PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */
-
-void PNGAPI
-png_set_compression_level(png_structrp png_ptr, int level)
-{
- png_debug(1, "in png_set_compression_level");
-
- if (png_ptr == NULL)
- return;
-
- png_ptr->zlib_level = level;
-}
-
-void PNGAPI
-png_set_compression_mem_level(png_structrp png_ptr, int mem_level)
-{
- png_debug(1, "in png_set_compression_mem_level");
-
- if (png_ptr == NULL)
- return;
-
- png_ptr->zlib_mem_level = mem_level;
-}
-
-void PNGAPI
-png_set_compression_strategy(png_structrp png_ptr, int strategy)
-{
- png_debug(1, "in png_set_compression_strategy");
-
- if (png_ptr == NULL)
- return;
-
- /* The flag setting here prevents the libpng dynamic selection of strategy.
- */
- png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_STRATEGY;
- png_ptr->zlib_strategy = strategy;
-}
-
-/* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a
- * smaller value of window_bits if it can do so safely.
- */
-void PNGAPI
-png_set_compression_window_bits(png_structrp png_ptr, int window_bits)
-{
- if (png_ptr == NULL)
- return;
-
- /* Prior to 1.6.0 this would warn but then set the window_bits value, this
- * meant that negative window bits values could be selected which would cause
- * libpng to write a non-standard PNG file with raw deflate or gzip
- * compressed IDAT or ancillary chunks. Such files can be read and there is
- * no warning on read, so this seems like a very bad idea.
- */
- if (window_bits > 15)
- {
- png_warning(png_ptr, "Only compression windows <= 32k supported by PNG");
- window_bits = 15;
- }
-
- else if (window_bits < 8)
- {
- png_warning(png_ptr, "Only compression windows >= 256 supported by PNG");
- window_bits = 8;
- }
-
- png_ptr->zlib_window_bits = window_bits;
-}
-
-void PNGAPI
-png_set_compression_method(png_structrp png_ptr, int method)
-{
- png_debug(1, "in png_set_compression_method");
-
- if (png_ptr == NULL)
- return;
-
- /* This would produce an invalid PNG file if it worked, but it doesn't and
- * deflate will fault it, so it is harmless to just warn here.
- */
- if (method != 8)
- png_warning(png_ptr, "Only compression method 8 is supported by PNG");
-
- png_ptr->zlib_method = method;
-}
-
-/* The following were added to libpng-1.5.4 */
-#ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
-void PNGAPI
-png_set_text_compression_level(png_structrp png_ptr, int level)
-{
- png_debug(1, "in png_set_text_compression_level");
-
- if (png_ptr == NULL)
- return;
-
- png_ptr->zlib_text_level = level;
-}
-
-void PNGAPI
-png_set_text_compression_mem_level(png_structrp png_ptr, int mem_level)
-{
- png_debug(1, "in png_set_text_compression_mem_level");
-
- if (png_ptr == NULL)
- return;
-
- png_ptr->zlib_text_mem_level = mem_level;
-}
-
-void PNGAPI
-png_set_text_compression_strategy(png_structrp png_ptr, int strategy)
-{
- png_debug(1, "in png_set_text_compression_strategy");
-
- if (png_ptr == NULL)
- return;
-
- png_ptr->zlib_text_strategy = strategy;
-}
-
-/* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a
- * smaller value of window_bits if it can do so safely.
- */
-void PNGAPI
-png_set_text_compression_window_bits(png_structrp png_ptr, int window_bits)
-{
- if (png_ptr == NULL)
- return;
-
- if (window_bits > 15)
- {
- png_warning(png_ptr, "Only compression windows <= 32k supported by PNG");
- window_bits = 15;
- }
-
- else if (window_bits < 8)
- {
- png_warning(png_ptr, "Only compression windows >= 256 supported by PNG");
- window_bits = 8;
- }
-
- png_ptr->zlib_text_window_bits = window_bits;
-}
-
-void PNGAPI
-png_set_text_compression_method(png_structrp png_ptr, int method)
-{
- png_debug(1, "in png_set_text_compression_method");
-
- if (png_ptr == NULL)
- return;
-
- if (method != 8)
- png_warning(png_ptr, "Only compression method 8 is supported by PNG");
-
- png_ptr->zlib_text_method = method;
-}
-#endif /* PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED */
-/* end of API added to libpng-1.5.4 */
-
-void PNGAPI
-png_set_write_status_fn(png_structrp png_ptr, png_write_status_ptr write_row_fn)
-{
- if (png_ptr == NULL)
- return;
-
- png_ptr->write_row_fn = write_row_fn;
-}
-
-#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
-void PNGAPI
-png_set_write_user_transform_fn(png_structrp png_ptr, png_user_transform_ptr
- write_user_transform_fn)
-{
- png_debug(1, "in png_set_write_user_transform_fn");
-
- if (png_ptr == NULL)
- return;
-
- png_ptr->transformations |= PNG_USER_TRANSFORM;
- png_ptr->write_user_transform_fn = write_user_transform_fn;
-}
-#endif
-
-
-#ifdef PNG_INFO_IMAGE_SUPPORTED
-void PNGAPI
-png_write_png(png_structrp png_ptr, png_inforp info_ptr,
- int transforms, voidp params)
-{
- if (png_ptr == NULL || info_ptr == NULL)
- return;
-
- /* Write the file header information. */
- png_write_info(png_ptr, info_ptr);
-
- /* ------ these transformations don't touch the info structure ------- */
-
-#ifdef PNG_WRITE_INVERT_SUPPORTED
- /* Invert monochrome pixels */
- if (transforms & PNG_TRANSFORM_INVERT_MONO)
- png_set_invert_mono(png_ptr);
-#endif
-
-#ifdef PNG_WRITE_SHIFT_SUPPORTED
- /* Shift the pixels up to a legal bit depth and fill in
- * as appropriate to correctly scale the image.
- */
- if ((transforms & PNG_TRANSFORM_SHIFT)
- && (info_ptr->valid & PNG_INFO_sBIT))
- png_set_shift(png_ptr, &info_ptr->sig_bit);
-#endif
-
-#ifdef PNG_WRITE_PACK_SUPPORTED
- /* Pack pixels into bytes */
- if (transforms & PNG_TRANSFORM_PACKING)
- png_set_packing(png_ptr);
-#endif
-
-#ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED
- /* Swap location of alpha bytes from ARGB to RGBA */
- if (transforms & PNG_TRANSFORM_SWAP_ALPHA)
- png_set_swap_alpha(png_ptr);
-#endif
-
-#ifdef PNG_WRITE_FILLER_SUPPORTED
- /* Pack XRGB/RGBX/ARGB/RGBA into RGB (4 channels -> 3 channels) */
- if (transforms & PNG_TRANSFORM_STRIP_FILLER_AFTER)
- png_set_filler(png_ptr, 0, PNG_FILLER_AFTER);
-
- else if (transforms & PNG_TRANSFORM_STRIP_FILLER_BEFORE)
- png_set_filler(png_ptr, 0, PNG_FILLER_BEFORE);
-#endif
-
-#ifdef PNG_WRITE_BGR_SUPPORTED
- /* Flip BGR pixels to RGB */
- if (transforms & PNG_TRANSFORM_BGR)
- png_set_bgr(png_ptr);
-#endif
-
-#ifdef PNG_WRITE_SWAP_SUPPORTED
- /* Swap bytes of 16-bit files to most significant byte first */
- if (transforms & PNG_TRANSFORM_SWAP_ENDIAN)
- png_set_swap(png_ptr);
-#endif
-
-#ifdef PNG_WRITE_PACKSWAP_SUPPORTED
- /* Swap bits of 1, 2, 4 bit packed pixel formats */
- if (transforms & PNG_TRANSFORM_PACKSWAP)
- png_set_packswap(png_ptr);
-#endif
-
-#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
- /* Invert the alpha channel from opacity to transparency */
- if (transforms & PNG_TRANSFORM_INVERT_ALPHA)
- png_set_invert_alpha(png_ptr);
-#endif
-
- /* ----------------------- end of transformations ------------------- */
-
- /* Write the bits */
- if (info_ptr->valid & PNG_INFO_IDAT)
- png_write_image(png_ptr, info_ptr->row_pointers);
-
- /* It is REQUIRED to call this to finish writing the rest of the file */
- png_write_end(png_ptr, info_ptr);
-
- PNG_UNUSED(transforms) /* Quiet compiler warnings */
- PNG_UNUSED(params)
-}
-#endif
-
-
-#ifdef PNG_SIMPLIFIED_WRITE_SUPPORTED
-#ifdef PNG_STDIO_SUPPORTED /* currently required for png_image_write_* */
-/* Initialize the write structure - general purpose utility. */
-static int
-png_image_write_init(png_imagep image)
-{
- png_structp png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, image,
- png_safe_error, png_safe_warning);
-
- if (png_ptr != NULL)
- {
- png_infop info_ptr = png_create_info_struct(png_ptr);
-
- if (info_ptr != NULL)
- {
- png_controlp control = png_voidcast(png_controlp,
- png_malloc_warn(png_ptr, (sizeof *control)));
-
- if (control != NULL)
- {
- memset(control, 0, (sizeof *control));
-
- control->png_ptr = png_ptr;
- control->info_ptr = info_ptr;
- control->for_write = 1;
-
- image->opaque = control;
- return 1;
- }
-
- /* Error clean up */
- png_destroy_info_struct(png_ptr, &info_ptr);
- }
-
- png_destroy_write_struct(&png_ptr, NULL);
- }
-
- return png_image_error(image, "png_image_write_: out of memory");
-}
-
-/* Arguments to png_image_write_main: */
-typedef struct
-{
- /* Arguments: */
- png_imagep image;
- png_const_voidp buffer;
- png_int_32 row_stride;
- png_const_voidp colormap;
- int convert_to_8bit;
- /* Local variables: */
- png_const_voidp first_row;
- ptrdiff_t row_bytes;
- png_voidp local_row;
-} png_image_write_control;
-
-/* Write png_uint_16 input to a 16-bit PNG; the png_ptr has already been set to
- * do any necessary byte swapping. The component order is defined by the
- * png_image format value.
- */
-static int
-png_write_image_16bit(png_voidp argument)
-{
- png_image_write_control *display = png_voidcast(png_image_write_control*,
- argument);
- png_imagep image = display->image;
- png_structrp png_ptr = image->opaque->png_ptr;
-
- png_const_uint_16p input_row = png_voidcast(png_const_uint_16p,
- display->first_row);
- png_uint_16p output_row = png_voidcast(png_uint_16p, display->local_row);
- png_uint_16p row_end;
- const int channels = (image->format & PNG_FORMAT_FLAG_COLOR) ? 3 : 1;
- int aindex = 0;
- png_uint_32 y = image->height;
-
- if (image->format & PNG_FORMAT_FLAG_ALPHA)
- {
- if (image->format & PNG_FORMAT_FLAG_AFIRST)
- {
- aindex = -1;
- ++input_row; /* To point to the first component */
- ++output_row;
- }
-
- else
- aindex = channels;
- }
-
- else
- png_error(png_ptr, "png_write_image: internal call error");
-
- /* Work out the output row end and count over this, note that the increment
- * above to 'row' means that row_end can actually be beyond the end of the
- * row; this is correct.
- */
- row_end = output_row + image->width * (channels+1);
-
- while (y-- > 0)
- {
- png_const_uint_16p in_ptr = input_row;
- png_uint_16p out_ptr = output_row;
-
- while (out_ptr < row_end)
- {
- const png_uint_16 alpha = in_ptr[aindex];
- png_uint_32 reciprocal = 0;
- int c;
-
- out_ptr[aindex] = alpha;
-
- /* Calculate a reciprocal. The correct calculation is simply
- * component/alpha*65535 << 15. (I.e. 15 bits of precision); this
- * allows correct rounding by adding .5 before the shift. 'reciprocal'
- * is only initialized when required.
- */
- if (alpha > 0 && alpha < 65535)
- reciprocal = ((0xffff<<15)+(alpha>>1))/alpha;
-
- c = channels;
- do /* always at least one channel */
- {
- png_uint_16 component = *in_ptr++;
-
- /* The following gives 65535 for an alpha of 0, which is fine,
- * otherwise if 0/0 is represented as some other value there is more
- * likely to be a discontinuity which will probably damage
- * compression when moving from a fully transparent area to a
- * nearly transparent one. (The assumption here is that opaque
- * areas tend not to be 0 intensity.)
- */
- if (component >= alpha)
- component = 65535;
-
- /* component<alpha, so component/alpha is less than one and
- * component*reciprocal is less than 2^31.
- */
- else if (component > 0 && alpha < 65535)
- {
- png_uint_32 calc = component * reciprocal;
- calc += 16384; /* round to nearest */
- component = (png_uint_16)(calc >> 15);
- }
-
- *out_ptr++ = component;
- }
- while (--c > 0);
-
- /* Skip to next component (skip the intervening alpha channel) */
- ++in_ptr;
- ++out_ptr;
- }
-
- png_write_row(png_ptr, png_voidcast(png_const_bytep, display->local_row));
- input_row += display->row_bytes/(sizeof (png_uint_16));
- }
-
- return 1;
-}
-
-/* Given 16-bit input (1 to 4 channels) write 8-bit output. If an alpha channel
- * is present it must be removed from the components, the components are then
- * written in sRGB encoding. No components are added or removed.
- *
- * Calculate an alpha reciprocal to reverse pre-multiplication. As above the
- * calculation can be done to 15 bits of accuracy; however, the output needs to
- * be scaled in the range 0..255*65535, so include that scaling here.
- */
-#define UNP_RECIPROCAL(alpha) ((((0xffff*0xff)<<7)+(alpha>>1))/alpha)
-
-static png_byte
-png_unpremultiply(png_uint_32 component, png_uint_32 alpha,
- png_uint_32 reciprocal/*from the above macro*/)
-{
- /* The following gives 1.0 for an alpha of 0, which is fine, otherwise if 0/0
- * is represented as some other value there is more likely to be a
- * discontinuity which will probably damage compression when moving from a
- * fully transparent area to a nearly transparent one. (The assumption here
- * is that opaque areas tend not to be 0 intensity.)
- *
- * There is a rounding problem here; if alpha is less than 128 it will end up
- * as 0 when scaled to 8 bits. To avoid introducing spurious colors into the
- * output change for this too.
- */
- if (component >= alpha || alpha < 128)
- return 255;
-
- /* component<alpha, so component/alpha is less than one and
- * component*reciprocal is less than 2^31.
- */
- else if (component > 0)
- {
- /* The test is that alpha/257 (rounded) is less than 255, the first value
- * that becomes 255 is 65407.
- * NOTE: this must agree with the PNG_DIV257 macro (which must, therefore,
- * be exact!) [Could also test reciprocal != 0]
- */
- if (alpha < 65407)
- {
- component *= reciprocal;
- component += 64; /* round to nearest */
- component >>= 7;
- }
-
- else
- component *= 255;
-
- /* Convert the component to sRGB. */
- return (png_byte)PNG_sRGB_FROM_LINEAR(component);
- }
-
- else
- return 0;
-}
-
-static int
-png_write_image_8bit(png_voidp argument)
-{
- png_image_write_control *display = png_voidcast(png_image_write_control*,
- argument);
- png_imagep image = display->image;
- png_structrp png_ptr = image->opaque->png_ptr;
-
- png_const_uint_16p input_row = png_voidcast(png_const_uint_16p,
- display->first_row);
- png_bytep output_row = png_voidcast(png_bytep, display->local_row);
- png_uint_32 y = image->height;
- const int channels = (image->format & PNG_FORMAT_FLAG_COLOR) ? 3 : 1;
-
- if (image->format & PNG_FORMAT_FLAG_ALPHA)
- {
- png_bytep row_end;
- int aindex;
-
- if (image->format & PNG_FORMAT_FLAG_AFIRST)
- {
- aindex = -1;
- ++input_row; /* To point to the first component */
- ++output_row;
- }
-
- else
- aindex = channels;
-
- /* Use row_end in place of a loop counter: */
- row_end = output_row + image->width * (channels+1);
-
- while (y-- > 0)
- {
- png_const_uint_16p in_ptr = input_row;
- png_bytep out_ptr = output_row;
-
- while (out_ptr < row_end)
- {
- png_uint_16 alpha = in_ptr[aindex];
- png_byte alphabyte = (png_byte)PNG_DIV257(alpha);
- png_uint_32 reciprocal = 0;
- int c;
-
- /* Scale and write the alpha channel. */
- out_ptr[aindex] = alphabyte;
-
- if (alphabyte > 0 && alphabyte < 255)
- reciprocal = UNP_RECIPROCAL(alpha);
-
- c = channels;
- do /* always at least one channel */
- *out_ptr++ = png_unpremultiply(*in_ptr++, alpha, reciprocal);
- while (--c > 0);
-
- /* Skip to next component (skip the intervening alpha channel) */
- ++in_ptr;
- ++out_ptr;
- } /* while out_ptr < row_end */
-
- png_write_row(png_ptr, png_voidcast(png_const_bytep,
- display->local_row));
- input_row += display->row_bytes/(sizeof (png_uint_16));
- } /* while y */
- }
-
- else
- {
- /* No alpha channel, so the row_end really is the end of the row and it
- * is sufficient to loop over the components one by one.
- */
- png_bytep row_end = output_row + image->width * channels;
-
- while (y-- > 0)
- {
- png_const_uint_16p in_ptr = input_row;
- png_bytep out_ptr = output_row;
-
- while (out_ptr < row_end)
- {
- png_uint_32 component = *in_ptr++;
-
- component *= 255;
- *out_ptr++ = (png_byte)PNG_sRGB_FROM_LINEAR(component);
- }
-
- png_write_row(png_ptr, output_row);
- input_row += display->row_bytes/(sizeof (png_uint_16));
- }
- }
-
- return 1;
-}
-
-static void
-png_image_set_PLTE(png_image_write_control *display)
-{
- const png_imagep image = display->image;
- const void *cmap = display->colormap;
- const int entries = image->colormap_entries > 256 ? 256 :
- (int)image->colormap_entries;
-
- /* NOTE: the caller must check for cmap != NULL and entries != 0 */
- const png_uint_32 format = image->format;
- const int channels = PNG_IMAGE_SAMPLE_CHANNELS(format);
-
-# ifdef PNG_FORMAT_BGR_SUPPORTED
- const int afirst = (format & PNG_FORMAT_FLAG_AFIRST) != 0 &&
- (format & PNG_FORMAT_FLAG_ALPHA) != 0;
-# else
-# define afirst 0
-# endif
-
-# ifdef PNG_FORMAT_BGR_SUPPORTED
- const int bgr = (format & PNG_FORMAT_FLAG_BGR) ? 2 : 0;
-# else
-# define bgr 0
-# endif
-
- int i, num_trans;
- png_color palette[256];
- png_byte tRNS[256];
-
- memset(tRNS, 255, (sizeof tRNS));
- memset(palette, 0, (sizeof palette));
-
- for (i=num_trans=0; i<entries; ++i)
- {
- /* This gets automatically converted to sRGB with reversal of the
- * pre-multiplication if the color-map has an alpha channel.
- */
- if (format & PNG_FORMAT_FLAG_LINEAR)
- {
- png_const_uint_16p entry = png_voidcast(png_const_uint_16p, cmap);
-
- entry += i * channels;
-
- if (channels & 1) /* no alpha */
- {
- if (channels >= 3) /* RGB */
- {
- palette[i].blue = (png_byte)PNG_sRGB_FROM_LINEAR(255 *
- entry[(2 ^ bgr)]);
- palette[i].green = (png_byte)PNG_sRGB_FROM_LINEAR(255 *
- entry[1]);
- palette[i].red = (png_byte)PNG_sRGB_FROM_LINEAR(255 *
- entry[bgr]);
- }
-
- else /* Gray */
- palette[i].blue = palette[i].red = palette[i].green =
- (png_byte)PNG_sRGB_FROM_LINEAR(255 * *entry);
- }
-
- else /* alpha */
- {
- png_uint_16 alpha = entry[afirst ? 0 : channels-1];
- png_byte alphabyte = (png_byte)PNG_DIV257(alpha);
- png_uint_32 reciprocal = 0;
-
- /* Calculate a reciprocal, as in the png_write_image_8bit code above
- * this is designed to produce a value scaled to 255*65535 when
- * divided by 128 (i.e. asr 7).
- */
- if (alphabyte > 0 && alphabyte < 255)
- reciprocal = (((0xffff*0xff)<<7)+(alpha>>1))/alpha;
-
- tRNS[i] = alphabyte;
- if (alphabyte < 255)
- num_trans = i+1;
-
- if (channels >= 3) /* RGB */
- {
- palette[i].blue = png_unpremultiply(entry[afirst + (2 ^ bgr)],
- alpha, reciprocal);
- palette[i].green = png_unpremultiply(entry[afirst + 1], alpha,
- reciprocal);
- palette[i].red = png_unpremultiply(entry[afirst + bgr], alpha,
- reciprocal);
- }
-
- else /* gray */
- palette[i].blue = palette[i].red = palette[i].green =
- png_unpremultiply(entry[afirst], alpha, reciprocal);
- }
- }
-
- else /* Color-map has sRGB values */
- {
- png_const_bytep entry = png_voidcast(png_const_bytep, cmap);
-
- entry += i * channels;
-
- switch (channels)
- {
- case 4:
- tRNS[i] = entry[afirst ? 0 : 3];
- if (tRNS[i] < 255)
- num_trans = i+1;
- /* FALL THROUGH */
- case 3:
- palette[i].blue = entry[afirst + (2 ^ bgr)];
- palette[i].green = entry[afirst + 1];
- palette[i].red = entry[afirst + bgr];
- break;
-
- case 2:
- tRNS[i] = entry[1 ^ afirst];
- if (tRNS[i] < 255)
- num_trans = i+1;
- /* FALL THROUGH */
- case 1:
- palette[i].blue = palette[i].red = palette[i].green =
- entry[afirst];
- break;
-
- default:
- break;
- }
- }
- }
-
-# ifdef afirst
-# undef afirst
-# endif
-# ifdef bgr
-# undef bgr
-# endif
-
- png_set_PLTE(image->opaque->png_ptr, image->opaque->info_ptr, palette,
- entries);
-
- if (num_trans > 0)
- png_set_tRNS(image->opaque->png_ptr, image->opaque->info_ptr, tRNS,
- num_trans, NULL);
-
- image->colormap_entries = entries;
-}
-
-static int
-png_image_write_main(png_voidp argument)
-{
- png_image_write_control *display = png_voidcast(png_image_write_control*,
- argument);
- png_imagep image = display->image;
- png_structrp png_ptr = image->opaque->png_ptr;
- png_inforp info_ptr = image->opaque->info_ptr;
- png_uint_32 format = image->format;
-
- int colormap = (format & PNG_FORMAT_FLAG_COLORMAP) != 0;
- int linear = !colormap && (format & PNG_FORMAT_FLAG_LINEAR) != 0; /* input */
- int alpha = !colormap && (format & PNG_FORMAT_FLAG_ALPHA) != 0;
- int write_16bit = linear && !colormap && !display->convert_to_8bit;
-
-# ifdef PNG_BENIGN_ERRORS_SUPPORTED
- /* Make sure we error out on any bad situation */
- png_set_benign_errors(png_ptr, 0/*error*/);
-# endif
-
- /* Default the 'row_stride' parameter if required. */
- if (display->row_stride == 0)
- display->row_stride = PNG_IMAGE_ROW_STRIDE(*image);
-
- /* Set the required transforms then write the rows in the correct order. */
- if (format & PNG_FORMAT_FLAG_COLORMAP)
- {
- if (display->colormap != NULL && image->colormap_entries > 0)
- {
- png_uint_32 entries = image->colormap_entries;
-
- png_set_IHDR(png_ptr, info_ptr, image->width, image->height,
- entries > 16 ? 8 : (entries > 4 ? 4 : (entries > 2 ? 2 : 1)),
- PNG_COLOR_TYPE_PALETTE, PNG_INTERLACE_NONE,
- PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
-
- png_image_set_PLTE(display);
- }
-
- else
- png_error(image->opaque->png_ptr,
- "no color-map for color-mapped image");
- }
-
- else
- png_set_IHDR(png_ptr, info_ptr, image->width, image->height,
- write_16bit ? 16 : 8,
- ((format & PNG_FORMAT_FLAG_COLOR) ? PNG_COLOR_MASK_COLOR : 0) +
- ((format & PNG_FORMAT_FLAG_ALPHA) ? PNG_COLOR_MASK_ALPHA : 0),
- PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
-
- /* Counter-intuitively the data transformations must be called *after*
- * png_write_info, not before as in the read code, but the 'set' functions
- * must still be called before. Just set the color space information, never
- * write an interlaced image.
- */
-
- if (write_16bit)
- {
- /* The gamma here is 1.0 (linear) and the cHRM chunk matches sRGB. */
- png_set_gAMA_fixed(png_ptr, info_ptr, PNG_GAMMA_LINEAR);
-
- if (!(image->flags & PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB))
- png_set_cHRM_fixed(png_ptr, info_ptr,
- /* color x y */
- /* white */ 31270, 32900,
- /* red */ 64000, 33000,
- /* green */ 30000, 60000,
- /* blue */ 15000, 6000
- );
- }
-
- else if (!(image->flags & PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB))
- png_set_sRGB(png_ptr, info_ptr, PNG_sRGB_INTENT_PERCEPTUAL);
-
- /* Else writing an 8-bit file and the *colors* aren't sRGB, but the 8-bit
- * space must still be gamma encoded.
- */
- else
- png_set_gAMA_fixed(png_ptr, info_ptr, PNG_GAMMA_sRGB_INVERSE);
-
- /* Write the file header. */
- png_write_info(png_ptr, info_ptr);
-
- /* Now set up the data transformations (*after* the header is written),
- * remove the handled transformations from the 'format' flags for checking.
- *
- * First check for a little endian system if writing 16 bit files.
- */
- if (write_16bit)
- {
- PNG_CONST png_uint_16 le = 0x0001;
-
- if (*(png_const_bytep)&le)
- png_set_swap(png_ptr);
- }
-
-# ifdef PNG_SIMPLIFIED_WRITE_BGR_SUPPORTED
- if (format & PNG_FORMAT_FLAG_BGR)
- {
- if (!colormap && (format & PNG_FORMAT_FLAG_COLOR) != 0)
- png_set_bgr(png_ptr);
- format &= ~PNG_FORMAT_FLAG_BGR;
- }
-# endif
-
-# ifdef PNG_SIMPLIFIED_WRITE_AFIRST_SUPPORTED
- if (format & PNG_FORMAT_FLAG_AFIRST)
- {
- if (!colormap && (format & PNG_FORMAT_FLAG_ALPHA) != 0)
- png_set_swap_alpha(png_ptr);
- format &= ~PNG_FORMAT_FLAG_AFIRST;
- }
-# endif
-
- /* If there are 16 or fewer color-map entries we wrote a lower bit depth
- * above, but the application data is still byte packed.
- */
- if (colormap && image->colormap_entries <= 16)
- png_set_packing(png_ptr);
-
- /* That should have handled all (both) the transforms. */
- if ((format & ~(png_uint_32)(PNG_FORMAT_FLAG_COLOR | PNG_FORMAT_FLAG_LINEAR |
- PNG_FORMAT_FLAG_ALPHA | PNG_FORMAT_FLAG_COLORMAP)) != 0)
- png_error(png_ptr, "png_write_image: unsupported transformation");
-
- {
- png_const_bytep row = png_voidcast(png_const_bytep, display->buffer);
- ptrdiff_t row_bytes = display->row_stride;
-
- if (linear)
- row_bytes *= (sizeof (png_uint_16));
-
- if (row_bytes < 0)
- row += (image->height-1) * (-row_bytes);
-
- display->first_row = row;
- display->row_bytes = row_bytes;
- }
-
- /* Apply 'fast' options if the flag is set. */
- if ((image->flags & PNG_IMAGE_FLAG_FAST) != 0)
- {
- png_set_filter(png_ptr, PNG_FILTER_TYPE_BASE, PNG_NO_FILTERS);
- /* NOTE: determined by experiment using pngstest, this reflects some
- * balance between the time to write the image once and the time to read
- * it about 50 times. The speed-up in pngstest was about 10-20% of the
- * total (user) time on a heavily loaded system.
- */
- png_set_compression_level(png_ptr, 3);
- }
-
- /* Check for the cases that currently require a pre-transform on the row
- * before it is written. This only applies when the input is 16-bit and
- * either there is an alpha channel or it is converted to 8-bit.
- */
- if ((linear && alpha) || (!colormap && display->convert_to_8bit))
- {
- png_bytep row = png_voidcast(png_bytep, png_malloc(png_ptr,
- png_get_rowbytes(png_ptr, info_ptr)));
- int result;
-
- display->local_row = row;
- if (write_16bit)
- result = png_safe_execute(image, png_write_image_16bit, display);
- else
- result = png_safe_execute(image, png_write_image_8bit, display);
- display->local_row = NULL;
-
- png_free(png_ptr, row);
-
- /* Skip the 'write_end' on error: */
- if (!result)
- return 0;
- }
-
- /* Otherwise this is the case where the input is in a format currently
- * supported by the rest of the libpng write code; call it directly.
- */
- else
- {
- png_const_bytep row = png_voidcast(png_const_bytep, display->first_row);
- ptrdiff_t row_bytes = display->row_bytes;
- png_uint_32 y = image->height;
-
- while (y-- > 0)
- {
- png_write_row(png_ptr, row);
- row += row_bytes;
- }
- }
-
- png_write_end(png_ptr, info_ptr);
- return 1;
-}
-
-int PNGAPI
-png_image_write_to_stdio(png_imagep image, FILE *file, int convert_to_8bit,
- const void *buffer, png_int_32 row_stride, const void *colormap)
-{
- /* Write the image to the given (FILE*). */
- if (image != NULL && image->version == PNG_IMAGE_VERSION)
- {
- if (file != NULL)
- {
- if (png_image_write_init(image))
- {
- png_image_write_control display;
- int result;
-
- /* This is slightly evil, but png_init_io doesn't do anything other
- * than this and we haven't changed the standard IO functions so
- * this saves a 'safe' function.
- */
- image->opaque->png_ptr->io_ptr = file;
-
- memset(&display, 0, (sizeof display));
- display.image = image;
- display.buffer = buffer;
- display.row_stride = row_stride;
- display.colormap = colormap;
- display.convert_to_8bit = convert_to_8bit;
-
- result = png_safe_execute(image, png_image_write_main, &display);
- png_image_free(image);
- return result;
- }
-
- else
- return 0;
- }
-
- else
- return png_image_error(image,
- "png_image_write_to_stdio: invalid argument");
- }
-
- else if (image != NULL)
- return png_image_error(image,
- "png_image_write_to_stdio: incorrect PNG_IMAGE_VERSION");
-
- else
- return 0;
-}
-
-int PNGAPI
-png_image_write_to_file(png_imagep image, const char *file_name,
- int convert_to_8bit, const void *buffer, png_int_32 row_stride,
- const void *colormap)
-{
- /* Write the image to the named file. */
- if (image != NULL && image->version == PNG_IMAGE_VERSION)
- {
- if (file_name != NULL)
- {
- FILE *fp = fopen(file_name, "wb");
-
- if (fp != NULL)
- {
- if (png_image_write_to_stdio(image, fp, convert_to_8bit, buffer,
- row_stride, colormap))
- {
- int error; /* from fflush/fclose */
-
- /* Make sure the file is flushed correctly. */
- if (fflush(fp) == 0 && ferror(fp) == 0)
- {
- if (fclose(fp) == 0)
- return 1;
-
- error = errno; /* from fclose */
- }
-
- else
- {
- error = errno; /* from fflush or ferror */
- (void)fclose(fp);
- }
-
- (void)remove(file_name);
- /* The image has already been cleaned up; this is just used to
- * set the error (because the original write succeeded).
- */
- return png_image_error(image, strerror(error));
- }
-
- else
- {
- /* Clean up: just the opened file. */
- (void)fclose(fp);
- (void)remove(file_name);
- return 0;
- }
- }
-
- else
- return png_image_error(image, strerror(errno));
- }
-
- else
- return png_image_error(image,
- "png_image_write_to_file: invalid argument");
- }
-
- else if (image != NULL)
- return png_image_error(image,
- "png_image_write_to_file: incorrect PNG_IMAGE_VERSION");
-
- else
- return 0;
-}
-#endif /* PNG_STDIO_SUPPORTED */
-#endif /* SIMPLIFIED_WRITE */
-#endif /* PNG_WRITE_SUPPORTED */
+
+/* pngwrite.c - general routines to write a PNG file
+ *
+ * Last changed in libpng 1.6.19 [November 12, 2015]
+ * Copyright (c) 1998-2015 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+
+#include "pngpriv.h"
+#if defined(PNG_SIMPLIFIED_WRITE_SUPPORTED) && defined(PNG_STDIO_SUPPORTED)
+# include <errno.h>
+#endif
+
+#ifdef PNG_WRITE_SUPPORTED
+
+#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
+/* Write out all the unknown chunks for the current given location */
+static void
+write_unknown_chunks(png_structrp png_ptr, png_const_inforp info_ptr,
+ unsigned int where)
+{
+ if (info_ptr->unknown_chunks_num != 0)
+ {
+ png_const_unknown_chunkp up;
+
+ png_debug(5, "writing extra chunks");
+
+ for (up = info_ptr->unknown_chunks;
+ up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
+ ++up)
+ if ((up->location & where) != 0)
+ {
+ /* If per-chunk unknown chunk handling is enabled use it, otherwise
+ * just write the chunks the application has set.
+ */
+#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
+ int keep = png_handle_as_unknown(png_ptr, up->name);
+
+ /* NOTE: this code is radically different from the read side in the
+ * matter of handling an ancillary unknown chunk. In the read side
+ * the default behavior is to discard it, in the code below the default
+ * behavior is to write it. Critical chunks are, however, only
+ * written if explicitly listed or if the default is set to write all
+ * unknown chunks.
+ *
+ * The default handling is also slightly weird - it is not possible to
+ * stop the writing of all unsafe-to-copy chunks!
+ *
+ * TODO: REVIEW: this would seem to be a bug.
+ */
+ if (keep != PNG_HANDLE_CHUNK_NEVER &&
+ ((up->name[3] & 0x20) /* safe-to-copy overrides everything */ ||
+ keep == PNG_HANDLE_CHUNK_ALWAYS ||
+ (keep == PNG_HANDLE_CHUNK_AS_DEFAULT &&
+ png_ptr->unknown_default == PNG_HANDLE_CHUNK_ALWAYS)))
+#endif
+ {
+ /* TODO: review, what is wrong with a zero length unknown chunk? */
+ if (up->size == 0)
+ png_warning(png_ptr, "Writing zero-length unknown chunk");
+
+ png_write_chunk(png_ptr, up->name, up->data, up->size);
+ }
+ }
+ }
+}
+#endif /* WRITE_UNKNOWN_CHUNKS */
+
+/* Writes all the PNG information. This is the suggested way to use the
+ * library. If you have a new chunk to add, make a function to write it,
+ * and put it in the correct location here. If you want the chunk written
+ * after the image data, put it in png_write_end(). I strongly encourage
+ * you to supply a PNG_INFO_ flag, and check info_ptr->valid before writing
+ * the chunk, as that will keep the code from breaking if you want to just
+ * write a plain PNG file. If you have long comments, I suggest writing
+ * them in png_write_end(), and compressing them.
+ */
+void PNGAPI
+png_write_info_before_PLTE(png_structrp png_ptr, png_const_inforp info_ptr)
+{
+ png_debug(1, "in png_write_info_before_PLTE");
+
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+ if ((png_ptr->mode & PNG_WROTE_INFO_BEFORE_PLTE) == 0)
+ {
+ /* Write PNG signature */
+ png_write_sig(png_ptr);
+
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+ if ((png_ptr->mode & PNG_HAVE_PNG_SIGNATURE) != 0 && \
+ png_ptr->mng_features_permitted != 0)
+ {
+ png_warning(png_ptr,
+ "MNG features are not allowed in a PNG datastream");
+ png_ptr->mng_features_permitted = 0;
+ }
+#endif
+
+ /* Write IHDR information. */
+ png_write_IHDR(png_ptr, info_ptr->width, info_ptr->height,
+ info_ptr->bit_depth, info_ptr->color_type, info_ptr->compression_type,
+ info_ptr->filter_type,
+#ifdef PNG_WRITE_INTERLACING_SUPPORTED
+ info_ptr->interlace_type
+#else
+ 0
+#endif
+ );
+
+ /* The rest of these check to see if the valid field has the appropriate
+ * flag set, and if it does, writes the chunk.
+ *
+ * 1.6.0: COLORSPACE support controls the writing of these chunks too, and
+ * the chunks will be written if the WRITE routine is there and
+ * information * is available in the COLORSPACE. (See
+ * png_colorspace_sync_info in png.c for where the valid flags get set.)
+ *
+ * Under certain circumstances the colorspace can be invalidated without
+ * syncing the info_struct 'valid' flags; this happens if libpng detects
+ * an error and calls png_error while the color space is being set, yet
+ * the application continues writing the PNG. So check the 'invalid'
+ * flag here too.
+ */
+#ifdef PNG_GAMMA_SUPPORTED
+# ifdef PNG_WRITE_gAMA_SUPPORTED
+ if ((info_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) == 0 &&
+ (info_ptr->colorspace.flags & PNG_COLORSPACE_FROM_gAMA) != 0 &&
+ (info_ptr->valid & PNG_INFO_gAMA) != 0)
+ png_write_gAMA_fixed(png_ptr, info_ptr->colorspace.gamma);
+# endif
+#endif
+
+#ifdef PNG_COLORSPACE_SUPPORTED
+ /* Write only one of sRGB or an ICC profile. If a profile was supplied
+ * and it matches one of the known sRGB ones issue a warning.
+ */
+# ifdef PNG_WRITE_iCCP_SUPPORTED
+ if ((info_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) == 0 &&
+ (info_ptr->valid & PNG_INFO_iCCP) != 0)
+ {
+# ifdef PNG_WRITE_sRGB_SUPPORTED
+ if ((info_ptr->valid & PNG_INFO_sRGB) != 0)
+ png_app_warning(png_ptr,
+ "profile matches sRGB but writing iCCP instead");
+# endif
+
+ png_write_iCCP(png_ptr, info_ptr->iccp_name,
+ info_ptr->iccp_profile);
+ }
+# ifdef PNG_WRITE_sRGB_SUPPORTED
+ else
+# endif
+# endif
+
+# ifdef PNG_WRITE_sRGB_SUPPORTED
+ if ((info_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) == 0 &&
+ (info_ptr->valid & PNG_INFO_sRGB) != 0)
+ png_write_sRGB(png_ptr, info_ptr->colorspace.rendering_intent);
+# endif /* WRITE_sRGB */
+#endif /* COLORSPACE */
+
+#ifdef PNG_WRITE_sBIT_SUPPORTED
+ if ((info_ptr->valid & PNG_INFO_sBIT) != 0)
+ png_write_sBIT(png_ptr, &(info_ptr->sig_bit), info_ptr->color_type);
+#endif
+
+#ifdef PNG_COLORSPACE_SUPPORTED
+# ifdef PNG_WRITE_cHRM_SUPPORTED
+ if ((info_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) == 0 &&
+ (info_ptr->colorspace.flags & PNG_COLORSPACE_FROM_cHRM) != 0 &&
+ (info_ptr->valid & PNG_INFO_cHRM) != 0)
+ png_write_cHRM_fixed(png_ptr, &info_ptr->colorspace.end_points_xy);
+# endif
+#endif
+
+#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
+ write_unknown_chunks(png_ptr, info_ptr, PNG_HAVE_IHDR);
+#endif
+
+ png_ptr->mode |= PNG_WROTE_INFO_BEFORE_PLTE;
+ }
+}
+
+void PNGAPI
+png_write_info(png_structrp png_ptr, png_const_inforp info_ptr)
+{
+#if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED)
+ int i;
+#endif
+
+ png_debug(1, "in png_write_info");
+
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+ png_write_info_before_PLTE(png_ptr, info_ptr);
+
+ if ((info_ptr->valid & PNG_INFO_PLTE) != 0)
+ png_write_PLTE(png_ptr, info_ptr->palette,
+ (png_uint_32)info_ptr->num_palette);
+
+ else if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+ png_error(png_ptr, "Valid palette required for paletted images");
+
+#ifdef PNG_WRITE_tRNS_SUPPORTED
+ if ((info_ptr->valid & PNG_INFO_tRNS) !=0)
+ {
+#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
+ /* Invert the alpha channel (in tRNS) */
+ if ((png_ptr->transformations & PNG_INVERT_ALPHA) != 0 &&
+ info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+ {
+ int j, jend;
+
+ jend = info_ptr->num_trans;
+ if (jend > PNG_MAX_PALETTE_LENGTH)
+ jend = PNG_MAX_PALETTE_LENGTH;
+
+ for (j = 0; j<jend; ++j)
+ info_ptr->trans_alpha[j] =
+ (png_byte)(255 - info_ptr->trans_alpha[j]);
+ }
+#endif
+ png_write_tRNS(png_ptr, info_ptr->trans_alpha, &(info_ptr->trans_color),
+ info_ptr->num_trans, info_ptr->color_type);
+ }
+#endif
+#ifdef PNG_WRITE_bKGD_SUPPORTED
+ if ((info_ptr->valid & PNG_INFO_bKGD) != 0)
+ png_write_bKGD(png_ptr, &(info_ptr->background), info_ptr->color_type);
+#endif
+
+#ifdef PNG_WRITE_hIST_SUPPORTED
+ if ((info_ptr->valid & PNG_INFO_hIST) != 0)
+ png_write_hIST(png_ptr, info_ptr->hist, info_ptr->num_palette);
+#endif
+
+#ifdef PNG_WRITE_oFFs_SUPPORTED
+ if ((info_ptr->valid & PNG_INFO_oFFs) != 0)
+ png_write_oFFs(png_ptr, info_ptr->x_offset, info_ptr->y_offset,
+ info_ptr->offset_unit_type);
+#endif
+
+#ifdef PNG_WRITE_pCAL_SUPPORTED
+ if ((info_ptr->valid & PNG_INFO_pCAL) != 0)
+ png_write_pCAL(png_ptr, info_ptr->pcal_purpose, info_ptr->pcal_X0,
+ info_ptr->pcal_X1, info_ptr->pcal_type, info_ptr->pcal_nparams,
+ info_ptr->pcal_units, info_ptr->pcal_params);
+#endif
+
+#ifdef PNG_WRITE_sCAL_SUPPORTED
+ if ((info_ptr->valid & PNG_INFO_sCAL) != 0)
+ png_write_sCAL_s(png_ptr, (int)info_ptr->scal_unit,
+ info_ptr->scal_s_width, info_ptr->scal_s_height);
+#endif /* sCAL */
+
+#ifdef PNG_WRITE_pHYs_SUPPORTED
+ if ((info_ptr->valid & PNG_INFO_pHYs) != 0)
+ png_write_pHYs(png_ptr, info_ptr->x_pixels_per_unit,
+ info_ptr->y_pixels_per_unit, info_ptr->phys_unit_type);
+#endif /* pHYs */
+
+#ifdef PNG_WRITE_tIME_SUPPORTED
+ if ((info_ptr->valid & PNG_INFO_tIME) != 0)
+ {
+ png_write_tIME(png_ptr, &(info_ptr->mod_time));
+ png_ptr->mode |= PNG_WROTE_tIME;
+ }
+#endif /* tIME */
+
+#ifdef PNG_WRITE_sPLT_SUPPORTED
+ if ((info_ptr->valid & PNG_INFO_sPLT) != 0)
+ for (i = 0; i < (int)info_ptr->splt_palettes_num; i++)
+ png_write_sPLT(png_ptr, info_ptr->splt_palettes + i);
+#endif /* sPLT */
+
+#ifdef PNG_WRITE_TEXT_SUPPORTED
+ /* Check to see if we need to write text chunks */
+ for (i = 0; i < info_ptr->num_text; i++)
+ {
+ png_debug2(2, "Writing header text chunk %d, type %d", i,
+ info_ptr->text[i].compression);
+ /* An internationalized chunk? */
+ if (info_ptr->text[i].compression > 0)
+ {
+#ifdef PNG_WRITE_iTXt_SUPPORTED
+ /* Write international chunk */
+ png_write_iTXt(png_ptr,
+ info_ptr->text[i].compression,
+ info_ptr->text[i].key,
+ info_ptr->text[i].lang,
+ info_ptr->text[i].lang_key,
+ info_ptr->text[i].text);
+ /* Mark this chunk as written */
+ if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE)
+ info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
+ else
+ info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR;
+#else
+ png_warning(png_ptr, "Unable to write international text");
+#endif
+ }
+
+ /* If we want a compressed text chunk */
+ else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_zTXt)
+ {
+#ifdef PNG_WRITE_zTXt_SUPPORTED
+ /* Write compressed chunk */
+ png_write_zTXt(png_ptr, info_ptr->text[i].key,
+ info_ptr->text[i].text, info_ptr->text[i].compression);
+ /* Mark this chunk as written */
+ info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR;
+#else
+ png_warning(png_ptr, "Unable to write compressed text");
+#endif
+ }
+
+ else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE)
+ {
+#ifdef PNG_WRITE_tEXt_SUPPORTED
+ /* Write uncompressed chunk */
+ png_write_tEXt(png_ptr, info_ptr->text[i].key,
+ info_ptr->text[i].text,
+ 0);
+ /* Mark this chunk as written */
+ info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
+#else
+ /* Can't get here */
+ png_warning(png_ptr, "Unable to write uncompressed text");
+#endif
+ }
+ }
+#endif /* tEXt */
+
+#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
+ write_unknown_chunks(png_ptr, info_ptr, PNG_HAVE_PLTE);
+#endif
+}
+
+/* Writes the end of the PNG file. If you don't want to write comments or
+ * time information, you can pass NULL for info. If you already wrote these
+ * in png_write_info(), do not write them again here. If you have long
+ * comments, I suggest writing them here, and compressing them.
+ */
+void PNGAPI
+png_write_end(png_structrp png_ptr, png_inforp info_ptr)
+{
+ png_debug(1, "in png_write_end");
+
+ if (png_ptr == NULL)
+ return;
+
+ if ((png_ptr->mode & PNG_HAVE_IDAT) == 0)
+ png_error(png_ptr, "No IDATs written into file");
+
+#ifdef PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED
+ if (png_ptr->num_palette_max > png_ptr->num_palette)
+ png_benign_error(png_ptr, "Wrote palette index exceeding num_palette");
+#endif
+
+ /* See if user wants us to write information chunks */
+ if (info_ptr != NULL)
+ {
+#ifdef PNG_WRITE_TEXT_SUPPORTED
+ int i; /* local index variable */
+#endif
+#ifdef PNG_WRITE_tIME_SUPPORTED
+ /* Check to see if user has supplied a time chunk */
+ if ((info_ptr->valid & PNG_INFO_tIME) != 0 &&
+ (png_ptr->mode & PNG_WROTE_tIME) == 0)
+ png_write_tIME(png_ptr, &(info_ptr->mod_time));
+
+#endif
+#ifdef PNG_WRITE_TEXT_SUPPORTED
+ /* Loop through comment chunks */
+ for (i = 0; i < info_ptr->num_text; i++)
+ {
+ png_debug2(2, "Writing trailer text chunk %d, type %d", i,
+ info_ptr->text[i].compression);
+ /* An internationalized chunk? */
+ if (info_ptr->text[i].compression > 0)
+ {
+#ifdef PNG_WRITE_iTXt_SUPPORTED
+ /* Write international chunk */
+ png_write_iTXt(png_ptr,
+ info_ptr->text[i].compression,
+ info_ptr->text[i].key,
+ info_ptr->text[i].lang,
+ info_ptr->text[i].lang_key,
+ info_ptr->text[i].text);
+ /* Mark this chunk as written */
+ if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE)
+ info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
+ else
+ info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR;
+#else
+ png_warning(png_ptr, "Unable to write international text");
+#endif
+ }
+
+ else if (info_ptr->text[i].compression >= PNG_TEXT_COMPRESSION_zTXt)
+ {
+#ifdef PNG_WRITE_zTXt_SUPPORTED
+ /* Write compressed chunk */
+ png_write_zTXt(png_ptr, info_ptr->text[i].key,
+ info_ptr->text[i].text, info_ptr->text[i].compression);
+ /* Mark this chunk as written */
+ info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR;
+#else
+ png_warning(png_ptr, "Unable to write compressed text");
+#endif
+ }
+
+ else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE)
+ {
+#ifdef PNG_WRITE_tEXt_SUPPORTED
+ /* Write uncompressed chunk */
+ png_write_tEXt(png_ptr, info_ptr->text[i].key,
+ info_ptr->text[i].text, 0);
+ /* Mark this chunk as written */
+ info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
+#else
+ png_warning(png_ptr, "Unable to write uncompressed text");
+#endif
+ }
+ }
+#endif
+#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
+ write_unknown_chunks(png_ptr, info_ptr, PNG_AFTER_IDAT);
+#endif
+ }
+
+ png_ptr->mode |= PNG_AFTER_IDAT;
+
+ /* Write end of PNG file */
+ png_write_IEND(png_ptr);
+
+ /* This flush, added in libpng-1.0.8, removed from libpng-1.0.9beta03,
+ * and restored again in libpng-1.2.30, may cause some applications that
+ * do not set png_ptr->output_flush_fn to crash. If your application
+ * experiences a problem, please try building libpng with
+ * PNG_WRITE_FLUSH_AFTER_IEND_SUPPORTED defined, and report the event to
+ * png-mng-implement at lists.sf.net .
+ */
+#ifdef PNG_WRITE_FLUSH_SUPPORTED
+# ifdef PNG_WRITE_FLUSH_AFTER_IEND_SUPPORTED
+ png_flush(png_ptr);
+# endif
+#endif
+}
+
+#ifdef PNG_CONVERT_tIME_SUPPORTED
+void PNGAPI
+png_convert_from_struct_tm(png_timep ptime, PNG_CONST struct tm * ttime)
+{
+ png_debug(1, "in png_convert_from_struct_tm");
+
+ ptime->year = (png_uint_16)(1900 + ttime->tm_year);
+ ptime->month = (png_byte)(ttime->tm_mon + 1);
+ ptime->day = (png_byte)ttime->tm_mday;
+ ptime->hour = (png_byte)ttime->tm_hour;
+ ptime->minute = (png_byte)ttime->tm_min;
+ ptime->second = (png_byte)ttime->tm_sec;
+}
+
+void PNGAPI
+png_convert_from_time_t(png_timep ptime, time_t ttime)
+{
+ struct tm *tbuf;
+
+ png_debug(1, "in png_convert_from_time_t");
+
+ tbuf = gmtime(&ttime);
+ png_convert_from_struct_tm(ptime, tbuf);
+}
+#endif
+
+/* Initialize png_ptr structure, and allocate any memory needed */
+PNG_FUNCTION(png_structp,PNGAPI
+png_create_write_struct,(png_const_charp user_png_ver, png_voidp error_ptr,
+ png_error_ptr error_fn, png_error_ptr warn_fn),PNG_ALLOCATED)
+{
+#ifndef PNG_USER_MEM_SUPPORTED
+ png_structrp png_ptr = png_create_png_struct(user_png_ver, error_ptr,
+ error_fn, warn_fn, NULL, NULL, NULL);
+#else
+ return png_create_write_struct_2(user_png_ver, error_ptr, error_fn,
+ warn_fn, NULL, NULL, NULL);
+}
+
+/* Alternate initialize png_ptr structure, and allocate any memory needed */
+PNG_FUNCTION(png_structp,PNGAPI
+png_create_write_struct_2,(png_const_charp user_png_ver, png_voidp error_ptr,
+ png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
+ png_malloc_ptr malloc_fn, png_free_ptr free_fn),PNG_ALLOCATED)
+{
+ png_structrp png_ptr = png_create_png_struct(user_png_ver, error_ptr,
+ error_fn, warn_fn, mem_ptr, malloc_fn, free_fn);
+#endif /* USER_MEM */
+ if (png_ptr != NULL)
+ {
+ /* Set the zlib control values to defaults; they can be overridden by the
+ * application after the struct has been created.
+ */
+ png_ptr->zbuffer_size = PNG_ZBUF_SIZE;
+
+ /* The 'zlib_strategy' setting is irrelevant because png_default_claim in
+ * pngwutil.c defaults it according to whether or not filters will be
+ * used, and ignores this setting.
+ */
+ png_ptr->zlib_strategy = PNG_Z_DEFAULT_STRATEGY;
+ png_ptr->zlib_level = PNG_Z_DEFAULT_COMPRESSION;
+ png_ptr->zlib_mem_level = 8;
+ png_ptr->zlib_window_bits = 15;
+ png_ptr->zlib_method = 8;
+
+#ifdef PNG_WRITE_COMPRESSED_TEXT_SUPPORTED
+ png_ptr->zlib_text_strategy = PNG_TEXT_Z_DEFAULT_STRATEGY;
+ png_ptr->zlib_text_level = PNG_TEXT_Z_DEFAULT_COMPRESSION;
+ png_ptr->zlib_text_mem_level = 8;
+ png_ptr->zlib_text_window_bits = 15;
+ png_ptr->zlib_text_method = 8;
+#endif /* WRITE_COMPRESSED_TEXT */
+
+ /* This is a highly dubious configuration option; by default it is off,
+ * but it may be appropriate for private builds that are testing
+ * extensions not conformant to the current specification, or of
+ * applications that must not fail to write at all costs!
+ */
+#ifdef PNG_BENIGN_WRITE_ERRORS_SUPPORTED
+ /* In stable builds only warn if an application error can be completely
+ * handled.
+ */
+ png_ptr->flags |= PNG_FLAG_BENIGN_ERRORS_WARN;
+#endif
+
+ /* App warnings are warnings in release (or release candidate) builds but
+ * are errors during development.
+ */
+#if PNG_RELEASE_BUILD
+ png_ptr->flags |= PNG_FLAG_APP_WARNINGS_WARN;
+#endif
+
+ /* TODO: delay this, it can be done in png_init_io() (if the app doesn't
+ * do it itself) avoiding setting the default function if it is not
+ * required.
+ */
+ png_set_write_fn(png_ptr, NULL, NULL, NULL);
+ }
+
+ return png_ptr;
+}
+
+
+/* Write a few rows of image data. If the image is interlaced,
+ * either you will have to write the 7 sub images, or, if you
+ * have called png_set_interlace_handling(), you will have to
+ * "write" the image seven times.
+ */
+void PNGAPI
+png_write_rows(png_structrp png_ptr, png_bytepp row,
+ png_uint_32 num_rows)
+{
+ png_uint_32 i; /* row counter */
+ png_bytepp rp; /* row pointer */
+
+ png_debug(1, "in png_write_rows");
+
+ if (png_ptr == NULL)
+ return;
+
+ /* Loop through the rows */
+ for (i = 0, rp = row; i < num_rows; i++, rp++)
+ {
+ png_write_row(png_ptr, *rp);
+ }
+}
+
+/* Write the image. You only need to call this function once, even
+ * if you are writing an interlaced image.
+ */
+void PNGAPI
+png_write_image(png_structrp png_ptr, png_bytepp image)
+{
+ png_uint_32 i; /* row index */
+ int pass, num_pass; /* pass variables */
+ png_bytepp rp; /* points to current row */
+
+ if (png_ptr == NULL)
+ return;
+
+ png_debug(1, "in png_write_image");
+
+#ifdef PNG_WRITE_INTERLACING_SUPPORTED
+ /* Initialize interlace handling. If image is not interlaced,
+ * this will set pass to 1
+ */
+ num_pass = png_set_interlace_handling(png_ptr);
+#else
+ num_pass = 1;
+#endif
+ /* Loop through passes */
+ for (pass = 0; pass < num_pass; pass++)
+ {
+ /* Loop through image */
+ for (i = 0, rp = image; i < png_ptr->height; i++, rp++)
+ {
+ png_write_row(png_ptr, *rp);
+ }
+ }
+}
+
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+/* Performs intrapixel differencing */
+static void
+png_do_write_intrapixel(png_row_infop row_info, png_bytep row)
+{
+ png_debug(1, "in png_do_write_intrapixel");
+
+ if ((row_info->color_type & PNG_COLOR_MASK_COLOR) != 0)
+ {
+ int bytes_per_pixel;
+ png_uint_32 row_width = row_info->width;
+ if (row_info->bit_depth == 8)
+ {
+ png_bytep rp;
+ png_uint_32 i;
+
+ if (row_info->color_type == PNG_COLOR_TYPE_RGB)
+ bytes_per_pixel = 3;
+
+ else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+ bytes_per_pixel = 4;
+
+ else
+ return;
+
+ for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel)
+ {
+ *(rp) = (png_byte)(*rp - *(rp + 1));
+ *(rp + 2) = (png_byte)(*(rp + 2) - *(rp + 1));
+ }
+ }
+
+#ifdef PNG_WRITE_16BIT_SUPPORTED
+ else if (row_info->bit_depth == 16)
+ {
+ png_bytep rp;
+ png_uint_32 i;
+
+ if (row_info->color_type == PNG_COLOR_TYPE_RGB)
+ bytes_per_pixel = 6;
+
+ else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+ bytes_per_pixel = 8;
+
+ else
+ return;
+
+ for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel)
+ {
+ png_uint_32 s0 = (*(rp ) << 8) | *(rp + 1);
+ png_uint_32 s1 = (*(rp + 2) << 8) | *(rp + 3);
+ png_uint_32 s2 = (*(rp + 4) << 8) | *(rp + 5);
+ png_uint_32 red = (png_uint_32)((s0 - s1) & 0xffffL);
+ png_uint_32 blue = (png_uint_32)((s2 - s1) & 0xffffL);
+ *(rp ) = (png_byte)(red >> 8);
+ *(rp + 1) = (png_byte)red;
+ *(rp + 4) = (png_byte)(blue >> 8);
+ *(rp + 5) = (png_byte)blue;
+ }
+ }
+#endif /* WRITE_16BIT */
+ }
+}
+#endif /* MNG_FEATURES */
+
+/* Called by user to write a row of image data */
+void PNGAPI
+png_write_row(png_structrp png_ptr, png_const_bytep row)
+{
+ /* 1.5.6: moved from png_struct to be a local structure: */
+ png_row_info row_info;
+
+ if (png_ptr == NULL)
+ return;
+
+ png_debug2(1, "in png_write_row (row %u, pass %d)",
+ png_ptr->row_number, png_ptr->pass);
+
+ /* Initialize transformations and other stuff if first time */
+ if (png_ptr->row_number == 0 && png_ptr->pass == 0)
+ {
+ /* Make sure we wrote the header info */
+ if ((png_ptr->mode & PNG_WROTE_INFO_BEFORE_PLTE) == 0)
+ png_error(png_ptr,
+ "png_write_info was never called before png_write_row");
+
+ /* Check for transforms that have been set but were defined out */
+#if !defined(PNG_WRITE_INVERT_SUPPORTED) && defined(PNG_READ_INVERT_SUPPORTED)
+ if ((png_ptr->transformations & PNG_INVERT_MONO) != 0)
+ png_warning(png_ptr, "PNG_WRITE_INVERT_SUPPORTED is not defined");
+#endif
+
+#if !defined(PNG_WRITE_FILLER_SUPPORTED) && defined(PNG_READ_FILLER_SUPPORTED)
+ if ((png_ptr->transformations & PNG_FILLER) != 0)
+ png_warning(png_ptr, "PNG_WRITE_FILLER_SUPPORTED is not defined");
+#endif
+#if !defined(PNG_WRITE_PACKSWAP_SUPPORTED) && \
+ defined(PNG_READ_PACKSWAP_SUPPORTED)
+ if ((png_ptr->transformations & PNG_PACKSWAP) != 0)
+ png_warning(png_ptr,
+ "PNG_WRITE_PACKSWAP_SUPPORTED is not defined");
+#endif
+
+#if !defined(PNG_WRITE_PACK_SUPPORTED) && defined(PNG_READ_PACK_SUPPORTED)
+ if ((png_ptr->transformations & PNG_PACK) != 0)
+ png_warning(png_ptr, "PNG_WRITE_PACK_SUPPORTED is not defined");
+#endif
+
+#if !defined(PNG_WRITE_SHIFT_SUPPORTED) && defined(PNG_READ_SHIFT_SUPPORTED)
+ if ((png_ptr->transformations & PNG_SHIFT) != 0)
+ png_warning(png_ptr, "PNG_WRITE_SHIFT_SUPPORTED is not defined");
+#endif
+
+#if !defined(PNG_WRITE_BGR_SUPPORTED) && defined(PNG_READ_BGR_SUPPORTED)
+ if ((png_ptr->transformations & PNG_BGR) != 0)
+ png_warning(png_ptr, "PNG_WRITE_BGR_SUPPORTED is not defined");
+#endif
+
+#if !defined(PNG_WRITE_SWAP_SUPPORTED) && defined(PNG_READ_SWAP_SUPPORTED)
+ if ((png_ptr->transformations & PNG_SWAP_BYTES) != 0)
+ png_warning(png_ptr, "PNG_WRITE_SWAP_SUPPORTED is not defined");
+#endif
+
+ png_write_start_row(png_ptr);
+ }
+
+#ifdef PNG_WRITE_INTERLACING_SUPPORTED
+ /* If interlaced and not interested in row, return */
+ if (png_ptr->interlaced != 0 &&
+ (png_ptr->transformations & PNG_INTERLACE) != 0)
+ {
+ switch (png_ptr->pass)
+ {
+ case 0:
+ if ((png_ptr->row_number & 0x07) != 0)
+ {
+ png_write_finish_row(png_ptr);
+ return;
+ }
+ break;
+
+ case 1:
+ if ((png_ptr->row_number & 0x07) != 0 || png_ptr->width < 5)
+ {
+ png_write_finish_row(png_ptr);
+ return;
+ }
+ break;
+
+ case 2:
+ if ((png_ptr->row_number & 0x07) != 4)
+ {
+ png_write_finish_row(png_ptr);
+ return;
+ }
+ break;
+
+ case 3:
+ if ((png_ptr->row_number & 0x03) != 0 || png_ptr->width < 3)
+ {
+ png_write_finish_row(png_ptr);
+ return;
+ }
+ break;
+
+ case 4:
+ if ((png_ptr->row_number & 0x03) != 2)
+ {
+ png_write_finish_row(png_ptr);
+ return;
+ }
+ break;
+
+ case 5:
+ if ((png_ptr->row_number & 0x01) != 0 || png_ptr->width < 2)
+ {
+ png_write_finish_row(png_ptr);
+ return;
+ }
+ break;
+
+ case 6:
+ if ((png_ptr->row_number & 0x01) == 0)
+ {
+ png_write_finish_row(png_ptr);
+ return;
+ }
+ break;
+
+ default: /* error: ignore it */
+ break;
+ }
+ }
+#endif
+
+ /* Set up row info for transformations */
+ row_info.color_type = png_ptr->color_type;
+ row_info.width = png_ptr->usr_width;
+ row_info.channels = png_ptr->usr_channels;
+ row_info.bit_depth = png_ptr->usr_bit_depth;
+ row_info.pixel_depth = (png_byte)(row_info.bit_depth * row_info.channels);
+ row_info.rowbytes = PNG_ROWBYTES(row_info.pixel_depth, row_info.width);
+
+ png_debug1(3, "row_info->color_type = %d", row_info.color_type);
+ png_debug1(3, "row_info->width = %u", row_info.width);
+ png_debug1(3, "row_info->channels = %d", row_info.channels);
+ png_debug1(3, "row_info->bit_depth = %d", row_info.bit_depth);
+ png_debug1(3, "row_info->pixel_depth = %d", row_info.pixel_depth);
+ png_debug1(3, "row_info->rowbytes = %lu", (unsigned long)row_info.rowbytes);
+
+ /* Copy user's row into buffer, leaving room for filter byte. */
+ memcpy(png_ptr->row_buf + 1, row, row_info.rowbytes);
+
+#ifdef PNG_WRITE_INTERLACING_SUPPORTED
+ /* Handle interlacing */
+ if (png_ptr->interlaced && png_ptr->pass < 6 &&
+ (png_ptr->transformations & PNG_INTERLACE) != 0)
+ {
+ png_do_write_interlace(&row_info, png_ptr->row_buf + 1, png_ptr->pass);
+ /* This should always get caught above, but still ... */
+ if (row_info.width == 0)
+ {
+ png_write_finish_row(png_ptr);
+ return;
+ }
+ }
+#endif
+
+#ifdef PNG_WRITE_TRANSFORMS_SUPPORTED
+ /* Handle other transformations */
+ if (png_ptr->transformations != 0)
+ png_do_write_transformations(png_ptr, &row_info);
+#endif
+
+ /* At this point the row_info pixel depth must match the 'transformed' depth,
+ * which is also the output depth.
+ */
+ if (row_info.pixel_depth != png_ptr->pixel_depth ||
+ row_info.pixel_depth != png_ptr->transformed_pixel_depth)
+ png_error(png_ptr, "internal write transform logic error");
+
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+ /* Write filter_method 64 (intrapixel differencing) only if
+ * 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and
+ * 2. Libpng did not write a PNG signature (this filter_method is only
+ * used in PNG datastreams that are embedded in MNG datastreams) and
+ * 3. The application called png_permit_mng_features with a mask that
+ * included PNG_FLAG_MNG_FILTER_64 and
+ * 4. The filter_method is 64 and
+ * 5. The color_type is RGB or RGBA
+ */
+ if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) != 0 &&
+ (png_ptr->filter_type == PNG_INTRAPIXEL_DIFFERENCING))
+ {
+ /* Intrapixel differencing */
+ png_do_write_intrapixel(&row_info, png_ptr->row_buf + 1);
+ }
+#endif
+
+/* Added at libpng-1.5.10 */
+#ifdef PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED
+ /* Check for out-of-range palette index */
+ if (row_info.color_type == PNG_COLOR_TYPE_PALETTE &&
+ png_ptr->num_palette_max >= 0)
+ png_do_check_palette_indexes(png_ptr, &row_info);
+#endif
+
+ /* Find a filter if necessary, filter the row and write it out. */
+ png_write_find_filter(png_ptr, &row_info);
+
+ if (png_ptr->write_row_fn != NULL)
+ (*(png_ptr->write_row_fn))(png_ptr, png_ptr->row_number, png_ptr->pass);
+}
+
+#ifdef PNG_WRITE_FLUSH_SUPPORTED
+/* Set the automatic flush interval or 0 to turn flushing off */
+void PNGAPI
+png_set_flush(png_structrp png_ptr, int nrows)
+{
+ png_debug(1, "in png_set_flush");
+
+ if (png_ptr == NULL)
+ return;
+
+ png_ptr->flush_dist = (nrows < 0 ? 0 : nrows);
+}
+
+/* Flush the current output buffers now */
+void PNGAPI
+png_write_flush(png_structrp png_ptr)
+{
+ png_debug(1, "in png_write_flush");
+
+ if (png_ptr == NULL)
+ return;
+
+ /* We have already written out all of the data */
+ if (png_ptr->row_number >= png_ptr->num_rows)
+ return;
+
+ png_compress_IDAT(png_ptr, NULL, 0, Z_SYNC_FLUSH);
+ png_ptr->flush_rows = 0;
+ png_flush(png_ptr);
+}
+#endif /* WRITE_FLUSH */
+
+/* Free any memory used in png_ptr struct without freeing the struct itself. */
+static void
+png_write_destroy(png_structrp png_ptr)
+{
+ png_debug(1, "in png_write_destroy");
+
+ /* Free any memory zlib uses */
+ if ((png_ptr->flags & PNG_FLAG_ZSTREAM_INITIALIZED) != 0)
+ deflateEnd(&png_ptr->zstream);
+
+ /* Free our memory. png_free checks NULL for us. */
+ png_free_buffer_list(png_ptr, &png_ptr->zbuffer_list);
+ png_free(png_ptr, png_ptr->row_buf);
+ png_ptr->row_buf = NULL;
+#ifdef PNG_WRITE_FILTER_SUPPORTED
+ png_free(png_ptr, png_ptr->prev_row);
+ png_free(png_ptr, png_ptr->try_row);
+ png_free(png_ptr, png_ptr->tst_row);
+ png_ptr->prev_row = NULL;
+ png_ptr->try_row = NULL;
+ png_ptr->tst_row = NULL;
+#endif
+
+#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
+ png_free(png_ptr, png_ptr->chunk_list);
+ png_ptr->chunk_list = NULL;
+#endif
+
+ /* The error handling and memory handling information is left intact at this
+ * point: the jmp_buf may still have to be freed. See png_destroy_png_struct
+ * for how this happens.
+ */
+}
+
+/* Free all memory used by the write.
+ * In libpng 1.6.0 this API changed quietly to no longer accept a NULL value for
+ * *png_ptr_ptr. Prior to 1.6.0 it would accept such a value and it would free
+ * the passed in info_structs but it would quietly fail to free any of the data
+ * inside them. In 1.6.0 it quietly does nothing (it has to be quiet because it
+ * has no png_ptr.)
+ */
+void PNGAPI
+png_destroy_write_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr)
+{
+ png_debug(1, "in png_destroy_write_struct");
+
+ if (png_ptr_ptr != NULL)
+ {
+ png_structrp png_ptr = *png_ptr_ptr;
+
+ if (png_ptr != NULL) /* added in libpng 1.6.0 */
+ {
+ png_destroy_info_struct(png_ptr, info_ptr_ptr);
+
+ *png_ptr_ptr = NULL;
+ png_write_destroy(png_ptr);
+ png_destroy_png_struct(png_ptr);
+ }
+ }
+}
+
+/* Allow the application to select one or more row filters to use. */
+void PNGAPI
+png_set_filter(png_structrp png_ptr, int method, int filters)
+{
+ png_debug(1, "in png_set_filter");
+
+ if (png_ptr == NULL)
+ return;
+
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+ if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) != 0 &&
+ (method == PNG_INTRAPIXEL_DIFFERENCING))
+ method = PNG_FILTER_TYPE_BASE;
+
+#endif
+ if (method == PNG_FILTER_TYPE_BASE)
+ {
+ switch (filters & (PNG_ALL_FILTERS | 0x07))
+ {
+#ifdef PNG_WRITE_FILTER_SUPPORTED
+ case 5:
+ case 6:
+ case 7: png_app_error(png_ptr, "Unknown row filter for method 0");
+ /* FALL THROUGH */
+#endif /* WRITE_FILTER */
+ case PNG_FILTER_VALUE_NONE:
+ png_ptr->do_filter = PNG_FILTER_NONE; break;
+
+#ifdef PNG_WRITE_FILTER_SUPPORTED
+ case PNG_FILTER_VALUE_SUB:
+ png_ptr->do_filter = PNG_FILTER_SUB; break;
+
+ case PNG_FILTER_VALUE_UP:
+ png_ptr->do_filter = PNG_FILTER_UP; break;
+
+ case PNG_FILTER_VALUE_AVG:
+ png_ptr->do_filter = PNG_FILTER_AVG; break;
+
+ case PNG_FILTER_VALUE_PAETH:
+ png_ptr->do_filter = PNG_FILTER_PAETH; break;
+
+ default:
+ png_ptr->do_filter = (png_byte)filters; break;
+#else
+ default:
+ png_app_error(png_ptr, "Unknown row filter for method 0");
+#endif /* WRITE_FILTER */
+ }
+
+#ifdef PNG_WRITE_FILTER_SUPPORTED
+ /* If we have allocated the row_buf, this means we have already started
+ * with the image and we should have allocated all of the filter buffers
+ * that have been selected. If prev_row isn't already allocated, then
+ * it is too late to start using the filters that need it, since we
+ * will be missing the data in the previous row. If an application
+ * wants to start and stop using particular filters during compression,
+ * it should start out with all of the filters, and then remove them
+ * or add them back after the start of compression.
+ *
+ * NOTE: this is a nasty constraint on the code, because it means that the
+ * prev_row buffer must be maintained even if there are currently no
+ * 'prev_row' requiring filters active.
+ */
+ if (png_ptr->row_buf != NULL)
+ {
+ int num_filters;
+ png_alloc_size_t buf_size;
+
+ /* Repeat the checks in png_write_start_row; 1 pixel high or wide
+ * images cannot benefit from certain filters. If this isn't done here
+ * the check below will fire on 1 pixel high images.
+ */
+ if (png_ptr->height == 1)
+ filters &= ~(PNG_FILTER_UP|PNG_FILTER_AVG|PNG_FILTER_PAETH);
+
+ if (png_ptr->width == 1)
+ filters &= ~(PNG_FILTER_SUB|PNG_FILTER_AVG|PNG_FILTER_PAETH);
+
+ if ((filters & (PNG_FILTER_UP|PNG_FILTER_AVG|PNG_FILTER_PAETH)) != 0
+ && png_ptr->prev_row == NULL)
+ {
+ /* This is the error case, however it is benign - the previous row
+ * is not available so the filter can't be used. Just warn here.
+ */
+ png_app_warning(png_ptr,
+ "png_set_filter: UP/AVG/PAETH cannot be added after start");
+ filters &= ~(PNG_FILTER_UP|PNG_FILTER_AVG|PNG_FILTER_PAETH);
+ }
+
+ num_filters = 0;
+
+ if (filters & PNG_FILTER_SUB)
+ num_filters++;
+
+ if (filters & PNG_FILTER_UP)
+ num_filters++;
+
+ if (filters & PNG_FILTER_AVG)
+ num_filters++;
+
+ if (filters & PNG_FILTER_PAETH)
+ num_filters++;
+
+ /* Allocate needed row buffers if they have not already been
+ * allocated.
+ */
+ buf_size = PNG_ROWBYTES(png_ptr->usr_channels * png_ptr->usr_bit_depth,
+ png_ptr->width) + 1;
+
+ if (png_ptr->try_row == NULL)
+ png_ptr->try_row = png_voidcast(png_bytep,
+ png_malloc(png_ptr, buf_size));
+
+ if (num_filters > 1)
+ {
+ if (png_ptr->tst_row == NULL)
+ png_ptr->tst_row = png_voidcast(png_bytep,
+ png_malloc(png_ptr, buf_size));
+ }
+ }
+ png_ptr->do_filter = (png_byte)filters;
+#endif
+ }
+ else
+ png_error(png_ptr, "Unknown custom filter method");
+}
+
+#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* DEPRECATED */
+/* Provide floating and fixed point APIs */
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+void PNGAPI
+png_set_filter_heuristics(png_structrp png_ptr, int heuristic_method,
+ int num_weights, png_const_doublep filter_weights,
+ png_const_doublep filter_costs)
+{
+ PNG_UNUSED(png_ptr)
+ PNG_UNUSED(heuristic_method)
+ PNG_UNUSED(num_weights)
+ PNG_UNUSED(filter_weights)
+ PNG_UNUSED(filter_costs)
+}
+#endif /* FLOATING_POINT */
+
+#ifdef PNG_FIXED_POINT_SUPPORTED
+void PNGAPI
+png_set_filter_heuristics_fixed(png_structrp png_ptr, int heuristic_method,
+ int num_weights, png_const_fixed_point_p filter_weights,
+ png_const_fixed_point_p filter_costs)
+{
+ PNG_UNUSED(png_ptr)
+ PNG_UNUSED(heuristic_method)
+ PNG_UNUSED(num_weights)
+ PNG_UNUSED(filter_weights)
+ PNG_UNUSED(filter_costs)
+}
+#endif /* FIXED_POINT */
+#endif /* WRITE_WEIGHTED_FILTER */
+
+#ifdef PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED
+void PNGAPI
+png_set_compression_level(png_structrp png_ptr, int level)
+{
+ png_debug(1, "in png_set_compression_level");
+
+ if (png_ptr == NULL)
+ return;
+
+ png_ptr->zlib_level = level;
+}
+
+void PNGAPI
+png_set_compression_mem_level(png_structrp png_ptr, int mem_level)
+{
+ png_debug(1, "in png_set_compression_mem_level");
+
+ if (png_ptr == NULL)
+ return;
+
+ png_ptr->zlib_mem_level = mem_level;
+}
+
+void PNGAPI
+png_set_compression_strategy(png_structrp png_ptr, int strategy)
+{
+ png_debug(1, "in png_set_compression_strategy");
+
+ if (png_ptr == NULL)
+ return;
+
+ /* The flag setting here prevents the libpng dynamic selection of strategy.
+ */
+ png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_STRATEGY;
+ png_ptr->zlib_strategy = strategy;
+}
+
+/* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a
+ * smaller value of window_bits if it can do so safely.
+ */
+void PNGAPI
+png_set_compression_window_bits(png_structrp png_ptr, int window_bits)
+{
+ if (png_ptr == NULL)
+ return;
+
+ /* Prior to 1.6.0 this would warn but then set the window_bits value. This
+ * meant that negative window bits values could be selected that would cause
+ * libpng to write a non-standard PNG file with raw deflate or gzip
+ * compressed IDAT or ancillary chunks. Such files can be read and there is
+ * no warning on read, so this seems like a very bad idea.
+ */
+ if (window_bits > 15)
+ {
+ png_warning(png_ptr, "Only compression windows <= 32k supported by PNG");
+ window_bits = 15;
+ }
+
+ else if (window_bits < 8)
+ {
+ png_warning(png_ptr, "Only compression windows >= 256 supported by PNG");
+ window_bits = 8;
+ }
+
+ png_ptr->zlib_window_bits = window_bits;
+}
+
+void PNGAPI
+png_set_compression_method(png_structrp png_ptr, int method)
+{
+ png_debug(1, "in png_set_compression_method");
+
+ if (png_ptr == NULL)
+ return;
+
+ /* This would produce an invalid PNG file if it worked, but it doesn't and
+ * deflate will fault it, so it is harmless to just warn here.
+ */
+ if (method != 8)
+ png_warning(png_ptr, "Only compression method 8 is supported by PNG");
+
+ png_ptr->zlib_method = method;
+}
+#endif /* WRITE_CUSTOMIZE_COMPRESSION */
+
+/* The following were added to libpng-1.5.4 */
+#ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
+void PNGAPI
+png_set_text_compression_level(png_structrp png_ptr, int level)
+{
+ png_debug(1, "in png_set_text_compression_level");
+
+ if (png_ptr == NULL)
+ return;
+
+ png_ptr->zlib_text_level = level;
+}
+
+void PNGAPI
+png_set_text_compression_mem_level(png_structrp png_ptr, int mem_level)
+{
+ png_debug(1, "in png_set_text_compression_mem_level");
+
+ if (png_ptr == NULL)
+ return;
+
+ png_ptr->zlib_text_mem_level = mem_level;
+}
+
+void PNGAPI
+png_set_text_compression_strategy(png_structrp png_ptr, int strategy)
+{
+ png_debug(1, "in png_set_text_compression_strategy");
+
+ if (png_ptr == NULL)
+ return;
+
+ png_ptr->zlib_text_strategy = strategy;
+}
+
+/* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a
+ * smaller value of window_bits if it can do so safely.
+ */
+void PNGAPI
+png_set_text_compression_window_bits(png_structrp png_ptr, int window_bits)
+{
+ if (png_ptr == NULL)
+ return;
+
+ if (window_bits > 15)
+ {
+ png_warning(png_ptr, "Only compression windows <= 32k supported by PNG");
+ window_bits = 15;
+ }
+
+ else if (window_bits < 8)
+ {
+ png_warning(png_ptr, "Only compression windows >= 256 supported by PNG");
+ window_bits = 8;
+ }
+
+ png_ptr->zlib_text_window_bits = window_bits;
+}
+
+void PNGAPI
+png_set_text_compression_method(png_structrp png_ptr, int method)
+{
+ png_debug(1, "in png_set_text_compression_method");
+
+ if (png_ptr == NULL)
+ return;
+
+ if (method != 8)
+ png_warning(png_ptr, "Only compression method 8 is supported by PNG");
+
+ png_ptr->zlib_text_method = method;
+}
+#endif /* WRITE_CUSTOMIZE_ZTXT_COMPRESSION */
+/* end of API added to libpng-1.5.4 */
+
+void PNGAPI
+png_set_write_status_fn(png_structrp png_ptr, png_write_status_ptr write_row_fn)
+{
+ if (png_ptr == NULL)
+ return;
+
+ png_ptr->write_row_fn = write_row_fn;
+}
+
+#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
+void PNGAPI
+png_set_write_user_transform_fn(png_structrp png_ptr, png_user_transform_ptr
+ write_user_transform_fn)
+{
+ png_debug(1, "in png_set_write_user_transform_fn");
+
+ if (png_ptr == NULL)
+ return;
+
+ png_ptr->transformations |= PNG_USER_TRANSFORM;
+ png_ptr->write_user_transform_fn = write_user_transform_fn;
+}
+#endif
+
+
+#ifdef PNG_INFO_IMAGE_SUPPORTED
+void PNGAPI
+png_write_png(png_structrp png_ptr, png_inforp info_ptr,
+ int transforms, voidp params)
+{
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+ if ((info_ptr->valid & PNG_INFO_IDAT) == 0)
+ {
+ png_app_error(png_ptr, "no rows for png_write_image to write");
+ return;
+ }
+
+ /* Write the file header information. */
+ png_write_info(png_ptr, info_ptr);
+
+ /* ------ these transformations don't touch the info structure ------- */
+
+ /* Invert monochrome pixels */
+ if ((transforms & PNG_TRANSFORM_INVERT_MONO) != 0)
+#ifdef PNG_WRITE_INVERT_SUPPORTED
+ png_set_invert_mono(png_ptr);
+#else
+ png_app_error(png_ptr, "PNG_TRANSFORM_INVERT_MONO not supported");
+#endif
+
+ /* Shift the pixels up to a legal bit depth and fill in
+ * as appropriate to correctly scale the image.
+ */
+ if ((transforms & PNG_TRANSFORM_SHIFT) != 0)
+#ifdef PNG_WRITE_SHIFT_SUPPORTED
+ if ((info_ptr->valid & PNG_INFO_sBIT) != 0)
+ png_set_shift(png_ptr, &info_ptr->sig_bit);
+#else
+ png_app_error(png_ptr, "PNG_TRANSFORM_SHIFT not supported");
+#endif
+
+ /* Pack pixels into bytes */
+ if ((transforms & PNG_TRANSFORM_PACKING) != 0)
+#ifdef PNG_WRITE_PACK_SUPPORTED
+ png_set_packing(png_ptr);
+#else
+ png_app_error(png_ptr, "PNG_TRANSFORM_PACKING not supported");
+#endif
+
+ /* Swap location of alpha bytes from ARGB to RGBA */
+ if ((transforms & PNG_TRANSFORM_SWAP_ALPHA) != 0)
+#ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED
+ png_set_swap_alpha(png_ptr);
+#else
+ png_app_error(png_ptr, "PNG_TRANSFORM_SWAP_ALPHA not supported");
+#endif
+
+ /* Remove a filler (X) from XRGB/RGBX/AG/GA into to convert it into
+ * RGB, note that the code expects the input color type to be G or RGB; no
+ * alpha channel.
+ */
+ if ((transforms & (PNG_TRANSFORM_STRIP_FILLER_AFTER|
+ PNG_TRANSFORM_STRIP_FILLER_BEFORE)) != 0)
+ {
+#ifdef PNG_WRITE_FILLER_SUPPORTED
+ if ((transforms & PNG_TRANSFORM_STRIP_FILLER_AFTER) != 0)
+ {
+ if ((transforms & PNG_TRANSFORM_STRIP_FILLER_BEFORE) != 0)
+ png_app_error(png_ptr,
+ "PNG_TRANSFORM_STRIP_FILLER: BEFORE+AFTER not supported");
+
+ /* Continue if ignored - this is the pre-1.6.10 behavior */
+ png_set_filler(png_ptr, 0, PNG_FILLER_AFTER);
+ }
+
+ else if ((transforms & PNG_TRANSFORM_STRIP_FILLER_BEFORE) != 0)
+ png_set_filler(png_ptr, 0, PNG_FILLER_BEFORE);
+#else
+ png_app_error(png_ptr, "PNG_TRANSFORM_STRIP_FILLER not supported");
+#endif
+ }
+
+ /* Flip BGR pixels to RGB */
+ if ((transforms & PNG_TRANSFORM_BGR) != 0)
+#ifdef PNG_WRITE_BGR_SUPPORTED
+ png_set_bgr(png_ptr);
+#else
+ png_app_error(png_ptr, "PNG_TRANSFORM_BGR not supported");
+#endif
+
+ /* Swap bytes of 16-bit files to most significant byte first */
+ if ((transforms & PNG_TRANSFORM_SWAP_ENDIAN) != 0)
+#ifdef PNG_WRITE_SWAP_SUPPORTED
+ png_set_swap(png_ptr);
+#else
+ png_app_error(png_ptr, "PNG_TRANSFORM_SWAP_ENDIAN not supported");
+#endif
+
+ /* Swap bits of 1-bit, 2-bit, 4-bit packed pixel formats */
+ if ((transforms & PNG_TRANSFORM_PACKSWAP) != 0)
+#ifdef PNG_WRITE_PACKSWAP_SUPPORTED
+ png_set_packswap(png_ptr);
+#else
+ png_app_error(png_ptr, "PNG_TRANSFORM_PACKSWAP not supported");
+#endif
+
+ /* Invert the alpha channel from opacity to transparency */
+ if ((transforms & PNG_TRANSFORM_INVERT_ALPHA) != 0)
+#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
+ png_set_invert_alpha(png_ptr);
+#else
+ png_app_error(png_ptr, "PNG_TRANSFORM_INVERT_ALPHA not supported");
+#endif
+
+ /* ----------------------- end of transformations ------------------- */
+
+ /* Write the bits */
+ png_write_image(png_ptr, info_ptr->row_pointers);
+
+ /* It is REQUIRED to call this to finish writing the rest of the file */
+ png_write_end(png_ptr, info_ptr);
+
+ PNG_UNUSED(params)
+}
+#endif
+
+
+#ifdef PNG_SIMPLIFIED_WRITE_SUPPORTED
+# ifdef PNG_STDIO_SUPPORTED /* currently required for png_image_write_* */
+/* Initialize the write structure - general purpose utility. */
+static int
+png_image_write_init(png_imagep image)
+{
+ png_structp png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, image,
+ png_safe_error, png_safe_warning);
+
+ if (png_ptr != NULL)
+ {
+ png_infop info_ptr = png_create_info_struct(png_ptr);
+
+ if (info_ptr != NULL)
+ {
+ png_controlp control = png_voidcast(png_controlp,
+ png_malloc_warn(png_ptr, (sizeof *control)));
+
+ if (control != NULL)
+ {
+ memset(control, 0, (sizeof *control));
+
+ control->png_ptr = png_ptr;
+ control->info_ptr = info_ptr;
+ control->for_write = 1;
+
+ image->opaque = control;
+ return 1;
+ }
+
+ /* Error clean up */
+ png_destroy_info_struct(png_ptr, &info_ptr);
+ }
+
+ png_destroy_write_struct(&png_ptr, NULL);
+ }
+
+ return png_image_error(image, "png_image_write_: out of memory");
+}
+
+/* Arguments to png_image_write_main: */
+typedef struct
+{
+ /* Arguments: */
+ png_imagep image;
+ png_const_voidp buffer;
+ png_int_32 row_stride;
+ png_const_voidp colormap;
+ int convert_to_8bit;
+ /* Local variables: */
+ png_const_voidp first_row;
+ ptrdiff_t row_bytes;
+ png_voidp local_row;
+} png_image_write_control;
+
+/* Write png_uint_16 input to a 16-bit PNG; the png_ptr has already been set to
+ * do any necessary byte swapping. The component order is defined by the
+ * png_image format value.
+ */
+static int
+png_write_image_16bit(png_voidp argument)
+{
+ png_image_write_control *display = png_voidcast(png_image_write_control*,
+ argument);
+ png_imagep image = display->image;
+ png_structrp png_ptr = image->opaque->png_ptr;
+
+ png_const_uint_16p input_row = png_voidcast(png_const_uint_16p,
+ display->first_row);
+ png_uint_16p output_row = png_voidcast(png_uint_16p, display->local_row);
+ png_uint_16p row_end;
+ const int channels = (image->format & PNG_FORMAT_FLAG_COLOR) != 0 ? 3 : 1;
+ int aindex = 0;
+ png_uint_32 y = image->height;
+
+ if ((image->format & PNG_FORMAT_FLAG_ALPHA) != 0)
+ {
+# ifdef PNG_SIMPLIFIED_WRITE_AFIRST_SUPPORTED
+ if ((image->format & PNG_FORMAT_FLAG_AFIRST) != 0)
+ {
+ aindex = -1;
+ ++input_row; /* To point to the first component */
+ ++output_row;
+ }
+ else
+ aindex = channels;
+# else
+ aindex = channels;
+# endif
+ }
+
+ else
+ png_error(png_ptr, "png_write_image: internal call error");
+
+ /* Work out the output row end and count over this, note that the increment
+ * above to 'row' means that row_end can actually be beyond the end of the
+ * row; this is correct.
+ */
+ row_end = output_row + image->width * (channels+1);
+
+ while (y-- > 0)
+ {
+ png_const_uint_16p in_ptr = input_row;
+ png_uint_16p out_ptr = output_row;
+
+ while (out_ptr < row_end)
+ {
+ const png_uint_16 alpha = in_ptr[aindex];
+ png_uint_32 reciprocal = 0;
+ int c;
+
+ out_ptr[aindex] = alpha;
+
+ /* Calculate a reciprocal. The correct calculation is simply
+ * component/alpha*65535 << 15. (I.e. 15 bits of precision); this
+ * allows correct rounding by adding .5 before the shift. 'reciprocal'
+ * is only initialized when required.
+ */
+ if (alpha > 0 && alpha < 65535)
+ reciprocal = ((0xffff<<15)+(alpha>>1))/alpha;
+
+ c = channels;
+ do /* always at least one channel */
+ {
+ png_uint_16 component = *in_ptr++;
+
+ /* The following gives 65535 for an alpha of 0, which is fine,
+ * otherwise if 0/0 is represented as some other value there is more
+ * likely to be a discontinuity which will probably damage
+ * compression when moving from a fully transparent area to a
+ * nearly transparent one. (The assumption here is that opaque
+ * areas tend not to be 0 intensity.)
+ */
+ if (component >= alpha)
+ component = 65535;
+
+ /* component<alpha, so component/alpha is less than one and
+ * component*reciprocal is less than 2^31.
+ */
+ else if (component > 0 && alpha < 65535)
+ {
+ png_uint_32 calc = component * reciprocal;
+ calc += 16384; /* round to nearest */
+ component = (png_uint_16)(calc >> 15);
+ }
+
+ *out_ptr++ = component;
+ }
+ while (--c > 0);
+
+ /* Skip to next component (skip the intervening alpha channel) */
+ ++in_ptr;
+ ++out_ptr;
+ }
+
+ png_write_row(png_ptr, png_voidcast(png_const_bytep, display->local_row));
+ input_row += display->row_bytes/(sizeof (png_uint_16));
+ }
+
+ return 1;
+}
+
+/* Given 16-bit input (1 to 4 channels) write 8-bit output. If an alpha channel
+ * is present it must be removed from the components, the components are then
+ * written in sRGB encoding. No components are added or removed.
+ *
+ * Calculate an alpha reciprocal to reverse pre-multiplication. As above the
+ * calculation can be done to 15 bits of accuracy; however, the output needs to
+ * be scaled in the range 0..255*65535, so include that scaling here.
+ */
+# define UNP_RECIPROCAL(alpha) ((((0xffff*0xff)<<7)+(alpha>>1))/alpha)
+
+static png_byte
+png_unpremultiply(png_uint_32 component, png_uint_32 alpha,
+ png_uint_32 reciprocal/*from the above macro*/)
+{
+ /* The following gives 1.0 for an alpha of 0, which is fine, otherwise if 0/0
+ * is represented as some other value there is more likely to be a
+ * discontinuity which will probably damage compression when moving from a
+ * fully transparent area to a nearly transparent one. (The assumption here
+ * is that opaque areas tend not to be 0 intensity.)
+ *
+ * There is a rounding problem here; if alpha is less than 128 it will end up
+ * as 0 when scaled to 8 bits. To avoid introducing spurious colors into the
+ * output change for this too.
+ */
+ if (component >= alpha || alpha < 128)
+ return 255;
+
+ /* component<alpha, so component/alpha is less than one and
+ * component*reciprocal is less than 2^31.
+ */
+ else if (component > 0)
+ {
+ /* The test is that alpha/257 (rounded) is less than 255, the first value
+ * that becomes 255 is 65407.
+ * NOTE: this must agree with the PNG_DIV257 macro (which must, therefore,
+ * be exact!) [Could also test reciprocal != 0]
+ */
+ if (alpha < 65407)
+ {
+ component *= reciprocal;
+ component += 64; /* round to nearest */
+ component >>= 7;
+ }
+
+ else
+ component *= 255;
+
+ /* Convert the component to sRGB. */
+ return (png_byte)PNG_sRGB_FROM_LINEAR(component);
+ }
+
+ else
+ return 0;
+}
+
+static int
+png_write_image_8bit(png_voidp argument)
+{
+ png_image_write_control *display = png_voidcast(png_image_write_control*,
+ argument);
+ png_imagep image = display->image;
+ png_structrp png_ptr = image->opaque->png_ptr;
+
+ png_const_uint_16p input_row = png_voidcast(png_const_uint_16p,
+ display->first_row);
+ png_bytep output_row = png_voidcast(png_bytep, display->local_row);
+ png_uint_32 y = image->height;
+ const int channels = (image->format & PNG_FORMAT_FLAG_COLOR) != 0 ? 3 : 1;
+
+ if ((image->format & PNG_FORMAT_FLAG_ALPHA) != 0)
+ {
+ png_bytep row_end;
+ int aindex;
+
+# ifdef PNG_SIMPLIFIED_WRITE_AFIRST_SUPPORTED
+ if ((image->format & PNG_FORMAT_FLAG_AFIRST) != 0)
+ {
+ aindex = -1;
+ ++input_row; /* To point to the first component */
+ ++output_row;
+ }
+
+ else
+# endif
+ aindex = channels;
+
+ /* Use row_end in place of a loop counter: */
+ row_end = output_row + image->width * (channels+1);
+
+ while (y-- > 0)
+ {
+ png_const_uint_16p in_ptr = input_row;
+ png_bytep out_ptr = output_row;
+
+ while (out_ptr < row_end)
+ {
+ png_uint_16 alpha = in_ptr[aindex];
+ png_byte alphabyte = (png_byte)PNG_DIV257(alpha);
+ png_uint_32 reciprocal = 0;
+ int c;
+
+ /* Scale and write the alpha channel. */
+ out_ptr[aindex] = alphabyte;
+
+ if (alphabyte > 0 && alphabyte < 255)
+ reciprocal = UNP_RECIPROCAL(alpha);
+
+ c = channels;
+ do /* always at least one channel */
+ *out_ptr++ = png_unpremultiply(*in_ptr++, alpha, reciprocal);
+ while (--c > 0);
+
+ /* Skip to next component (skip the intervening alpha channel) */
+ ++in_ptr;
+ ++out_ptr;
+ } /* while out_ptr < row_end */
+
+ png_write_row(png_ptr, png_voidcast(png_const_bytep,
+ display->local_row));
+ input_row += display->row_bytes/(sizeof (png_uint_16));
+ } /* while y */
+ }
+
+ else
+ {
+ /* No alpha channel, so the row_end really is the end of the row and it
+ * is sufficient to loop over the components one by one.
+ */
+ png_bytep row_end = output_row + image->width * channels;
+
+ while (y-- > 0)
+ {
+ png_const_uint_16p in_ptr = input_row;
+ png_bytep out_ptr = output_row;
+
+ while (out_ptr < row_end)
+ {
+ png_uint_32 component = *in_ptr++;
+
+ component *= 255;
+ *out_ptr++ = (png_byte)PNG_sRGB_FROM_LINEAR(component);
+ }
+
+ png_write_row(png_ptr, output_row);
+ input_row += display->row_bytes/(sizeof (png_uint_16));
+ }
+ }
+
+ return 1;
+}
+
+static void
+png_image_set_PLTE(png_image_write_control *display)
+{
+ const png_imagep image = display->image;
+ const void *cmap = display->colormap;
+ const int entries = image->colormap_entries > 256 ? 256 :
+ (int)image->colormap_entries;
+
+ /* NOTE: the caller must check for cmap != NULL and entries != 0 */
+ const png_uint_32 format = image->format;
+ const int channels = PNG_IMAGE_SAMPLE_CHANNELS(format);
+
+# if defined(PNG_FORMAT_BGR_SUPPORTED) &&\
+ defined(PNG_SIMPLIFIED_WRITE_AFIRST_SUPPORTED)
+ const int afirst = (format & PNG_FORMAT_FLAG_AFIRST) != 0 &&
+ (format & PNG_FORMAT_FLAG_ALPHA) != 0;
+# else
+# define afirst 0
+# endif
+
+# ifdef PNG_FORMAT_BGR_SUPPORTED
+ const int bgr = (format & PNG_FORMAT_FLAG_BGR) != 0 ? 2 : 0;
+# else
+# define bgr 0
+# endif
+
+ int i, num_trans;
+ png_color palette[256];
+ png_byte tRNS[256];
+
+ memset(tRNS, 255, (sizeof tRNS));
+ memset(palette, 0, (sizeof palette));
+
+ for (i=num_trans=0; i<entries; ++i)
+ {
+ /* This gets automatically converted to sRGB with reversal of the
+ * pre-multiplication if the color-map has an alpha channel.
+ */
+ if ((format & PNG_FORMAT_FLAG_LINEAR) != 0)
+ {
+ png_const_uint_16p entry = png_voidcast(png_const_uint_16p, cmap);
+
+ entry += i * channels;
+
+ if ((channels & 1) != 0) /* no alpha */
+ {
+ if (channels >= 3) /* RGB */
+ {
+ palette[i].blue = (png_byte)PNG_sRGB_FROM_LINEAR(255 *
+ entry[(2 ^ bgr)]);
+ palette[i].green = (png_byte)PNG_sRGB_FROM_LINEAR(255 *
+ entry[1]);
+ palette[i].red = (png_byte)PNG_sRGB_FROM_LINEAR(255 *
+ entry[bgr]);
+ }
+
+ else /* Gray */
+ palette[i].blue = palette[i].red = palette[i].green =
+ (png_byte)PNG_sRGB_FROM_LINEAR(255 * *entry);
+ }
+
+ else /* alpha */
+ {
+ png_uint_16 alpha = entry[afirst ? 0 : channels-1];
+ png_byte alphabyte = (png_byte)PNG_DIV257(alpha);
+ png_uint_32 reciprocal = 0;
+
+ /* Calculate a reciprocal, as in the png_write_image_8bit code above
+ * this is designed to produce a value scaled to 255*65535 when
+ * divided by 128 (i.e. asr 7).
+ */
+ if (alphabyte > 0 && alphabyte < 255)
+ reciprocal = (((0xffff*0xff)<<7)+(alpha>>1))/alpha;
+
+ tRNS[i] = alphabyte;
+ if (alphabyte < 255)
+ num_trans = i+1;
+
+ if (channels >= 3) /* RGB */
+ {
+ palette[i].blue = png_unpremultiply(entry[afirst + (2 ^ bgr)],
+ alpha, reciprocal);
+ palette[i].green = png_unpremultiply(entry[afirst + 1], alpha,
+ reciprocal);
+ palette[i].red = png_unpremultiply(entry[afirst + bgr], alpha,
+ reciprocal);
+ }
+
+ else /* gray */
+ palette[i].blue = palette[i].red = palette[i].green =
+ png_unpremultiply(entry[afirst], alpha, reciprocal);
+ }
+ }
+
+ else /* Color-map has sRGB values */
+ {
+ png_const_bytep entry = png_voidcast(png_const_bytep, cmap);
+
+ entry += i * channels;
+
+ switch (channels)
+ {
+ case 4:
+ tRNS[i] = entry[afirst ? 0 : 3];
+ if (tRNS[i] < 255)
+ num_trans = i+1;
+ /* FALL THROUGH */
+ case 3:
+ palette[i].blue = entry[afirst + (2 ^ bgr)];
+ palette[i].green = entry[afirst + 1];
+ palette[i].red = entry[afirst + bgr];
+ break;
+
+ case 2:
+ tRNS[i] = entry[1 ^ afirst];
+ if (tRNS[i] < 255)
+ num_trans = i+1;
+ /* FALL THROUGH */
+ case 1:
+ palette[i].blue = palette[i].red = palette[i].green =
+ entry[afirst];
+ break;
+
+ default:
+ break;
+ }
+ }
+ }
+
+# ifdef afirst
+# undef afirst
+# endif
+# ifdef bgr
+# undef bgr
+# endif
+
+ png_set_PLTE(image->opaque->png_ptr, image->opaque->info_ptr, palette,
+ entries);
+
+ if (num_trans > 0)
+ png_set_tRNS(image->opaque->png_ptr, image->opaque->info_ptr, tRNS,
+ num_trans, NULL);
+
+ image->colormap_entries = entries;
+}
+
+static int
+png_image_write_main(png_voidp argument)
+{
+ png_image_write_control *display = png_voidcast(png_image_write_control*,
+ argument);
+ png_imagep image = display->image;
+ png_structrp png_ptr = image->opaque->png_ptr;
+ png_inforp info_ptr = image->opaque->info_ptr;
+ png_uint_32 format = image->format;
+
+ /* The following four ints are actually booleans */
+ int colormap = (format & PNG_FORMAT_FLAG_COLORMAP);
+ int linear = !colormap && (format & PNG_FORMAT_FLAG_LINEAR); /* input */
+ int alpha = !colormap && (format & PNG_FORMAT_FLAG_ALPHA);
+ int write_16bit = linear && !colormap && (display->convert_to_8bit == 0);
+
+# ifdef PNG_BENIGN_ERRORS_SUPPORTED
+ /* Make sure we error out on any bad situation */
+ png_set_benign_errors(png_ptr, 0/*error*/);
+# endif
+
+ /* Default the 'row_stride' parameter if required. */
+ if (display->row_stride == 0)
+ display->row_stride = PNG_IMAGE_ROW_STRIDE(*image);
+
+ /* Set the required transforms then write the rows in the correct order. */
+ if ((format & PNG_FORMAT_FLAG_COLORMAP) != 0)
+ {
+ if (display->colormap != NULL && image->colormap_entries > 0)
+ {
+ png_uint_32 entries = image->colormap_entries;
+
+ png_set_IHDR(png_ptr, info_ptr, image->width, image->height,
+ entries > 16 ? 8 : (entries > 4 ? 4 : (entries > 2 ? 2 : 1)),
+ PNG_COLOR_TYPE_PALETTE, PNG_INTERLACE_NONE,
+ PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
+
+ png_image_set_PLTE(display);
+ }
+
+ else
+ png_error(image->opaque->png_ptr,
+ "no color-map for color-mapped image");
+ }
+
+ else
+ png_set_IHDR(png_ptr, info_ptr, image->width, image->height,
+ write_16bit ? 16 : 8,
+ ((format & PNG_FORMAT_FLAG_COLOR) ? PNG_COLOR_MASK_COLOR : 0) +
+ ((format & PNG_FORMAT_FLAG_ALPHA) ? PNG_COLOR_MASK_ALPHA : 0),
+ PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
+
+ /* Counter-intuitively the data transformations must be called *after*
+ * png_write_info, not before as in the read code, but the 'set' functions
+ * must still be called before. Just set the color space information, never
+ * write an interlaced image.
+ */
+
+ if (write_16bit != 0)
+ {
+ /* The gamma here is 1.0 (linear) and the cHRM chunk matches sRGB. */
+ png_set_gAMA_fixed(png_ptr, info_ptr, PNG_GAMMA_LINEAR);
+
+ if ((image->flags & PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB) == 0)
+ png_set_cHRM_fixed(png_ptr, info_ptr,
+ /* color x y */
+ /* white */ 31270, 32900,
+ /* red */ 64000, 33000,
+ /* green */ 30000, 60000,
+ /* blue */ 15000, 6000
+ );
+ }
+
+ else if ((image->flags & PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB) == 0)
+ png_set_sRGB(png_ptr, info_ptr, PNG_sRGB_INTENT_PERCEPTUAL);
+
+ /* Else writing an 8-bit file and the *colors* aren't sRGB, but the 8-bit
+ * space must still be gamma encoded.
+ */
+ else
+ png_set_gAMA_fixed(png_ptr, info_ptr, PNG_GAMMA_sRGB_INVERSE);
+
+ /* Write the file header. */
+ png_write_info(png_ptr, info_ptr);
+
+ /* Now set up the data transformations (*after* the header is written),
+ * remove the handled transformations from the 'format' flags for checking.
+ *
+ * First check for a little endian system if writing 16-bit files.
+ */
+ if (write_16bit != 0)
+ {
+ PNG_CONST png_uint_16 le = 0x0001;
+
+ if ((*(png_const_bytep) & le) != 0)
+ png_set_swap(png_ptr);
+ }
+
+# ifdef PNG_SIMPLIFIED_WRITE_BGR_SUPPORTED
+ if ((format & PNG_FORMAT_FLAG_BGR) != 0)
+ {
+ if (colormap == 0 && (format & PNG_FORMAT_FLAG_COLOR) != 0)
+ png_set_bgr(png_ptr);
+ format &= ~PNG_FORMAT_FLAG_BGR;
+ }
+# endif
+
+# ifdef PNG_SIMPLIFIED_WRITE_AFIRST_SUPPORTED
+ if ((format & PNG_FORMAT_FLAG_AFIRST) != 0)
+ {
+ if (colormap == 0 && (format & PNG_FORMAT_FLAG_ALPHA) != 0)
+ png_set_swap_alpha(png_ptr);
+ format &= ~PNG_FORMAT_FLAG_AFIRST;
+ }
+# endif
+
+ /* If there are 16 or fewer color-map entries we wrote a lower bit depth
+ * above, but the application data is still byte packed.
+ */
+ if (colormap != 0 && image->colormap_entries <= 16)
+ png_set_packing(png_ptr);
+
+ /* That should have handled all (both) the transforms. */
+ if ((format & ~(png_uint_32)(PNG_FORMAT_FLAG_COLOR | PNG_FORMAT_FLAG_LINEAR |
+ PNG_FORMAT_FLAG_ALPHA | PNG_FORMAT_FLAG_COLORMAP)) != 0)
+ png_error(png_ptr, "png_write_image: unsupported transformation");
+
+ {
+ png_const_bytep row = png_voidcast(png_const_bytep, display->buffer);
+ ptrdiff_t row_bytes = display->row_stride;
+
+ if (linear != 0)
+ row_bytes *= (sizeof (png_uint_16));
+
+ if (row_bytes < 0)
+ row += (image->height-1) * (-row_bytes);
+
+ display->first_row = row;
+ display->row_bytes = row_bytes;
+ }
+
+ /* Apply 'fast' options if the flag is set. */
+ if ((image->flags & PNG_IMAGE_FLAG_FAST) != 0)
+ {
+ png_set_filter(png_ptr, PNG_FILTER_TYPE_BASE, PNG_NO_FILTERS);
+ /* NOTE: determined by experiment using pngstest, this reflects some
+ * balance between the time to write the image once and the time to read
+ * it about 50 times. The speed-up in pngstest was about 10-20% of the
+ * total (user) time on a heavily loaded system.
+ */
+# ifdef PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED
+ png_set_compression_level(png_ptr, 3);
+# endif
+ }
+
+ /* Check for the cases that currently require a pre-transform on the row
+ * before it is written. This only applies when the input is 16-bit and
+ * either there is an alpha channel or it is converted to 8-bit.
+ */
+ if ((linear != 0 && alpha != 0 ) ||
+ (colormap == 0 && display->convert_to_8bit != 0))
+ {
+ png_bytep row = png_voidcast(png_bytep, png_malloc(png_ptr,
+ png_get_rowbytes(png_ptr, info_ptr)));
+ int result;
+
+ display->local_row = row;
+ if (write_16bit != 0)
+ result = png_safe_execute(image, png_write_image_16bit, display);
+ else
+ result = png_safe_execute(image, png_write_image_8bit, display);
+ display->local_row = NULL;
+
+ png_free(png_ptr, row);
+
+ /* Skip the 'write_end' on error: */
+ if (result == 0)
+ return 0;
+ }
+
+ /* Otherwise this is the case where the input is in a format currently
+ * supported by the rest of the libpng write code; call it directly.
+ */
+ else
+ {
+ png_const_bytep row = png_voidcast(png_const_bytep, display->first_row);
+ ptrdiff_t row_bytes = display->row_bytes;
+ png_uint_32 y = image->height;
+
+ while (y-- > 0)
+ {
+ png_write_row(png_ptr, row);
+ row += row_bytes;
+ }
+ }
+
+ png_write_end(png_ptr, info_ptr);
+ return 1;
+}
+
+int PNGAPI
+png_image_write_to_stdio(png_imagep image, FILE *file, int convert_to_8bit,
+ const void *buffer, png_int_32 row_stride, const void *colormap)
+{
+ /* Write the image to the given (FILE*). */
+ if (image != NULL && image->version == PNG_IMAGE_VERSION)
+ {
+ if (file != NULL)
+ {
+ if (png_image_write_init(image) != 0)
+ {
+ png_image_write_control display;
+ int result;
+
+ /* This is slightly evil, but png_init_io doesn't do anything other
+ * than this and we haven't changed the standard IO functions so
+ * this saves a 'safe' function.
+ */
+ image->opaque->png_ptr->io_ptr = file;
+
+ memset(&display, 0, (sizeof display));
+ display.image = image;
+ display.buffer = buffer;
+ display.row_stride = row_stride;
+ display.colormap = colormap;
+ display.convert_to_8bit = convert_to_8bit;
+
+ result = png_safe_execute(image, png_image_write_main, &display);
+ png_image_free(image);
+ return result;
+ }
+
+ else
+ return 0;
+ }
+
+ else
+ return png_image_error(image,
+ "png_image_write_to_stdio: invalid argument");
+ }
+
+ else if (image != NULL)
+ return png_image_error(image,
+ "png_image_write_to_stdio: incorrect PNG_IMAGE_VERSION");
+
+ else
+ return 0;
+}
+
+int PNGAPI
+png_image_write_to_file(png_imagep image, const char *file_name,
+ int convert_to_8bit, const void *buffer, png_int_32 row_stride,
+ const void *colormap)
+{
+ /* Write the image to the named file. */
+ if (image != NULL && image->version == PNG_IMAGE_VERSION)
+ {
+ if (file_name != NULL)
+ {
+ FILE *fp = fopen(file_name, "wb");
+
+ if (fp != NULL)
+ {
+ if (png_image_write_to_stdio(image, fp, convert_to_8bit, buffer,
+ row_stride, colormap) != 0)
+ {
+ int error; /* from fflush/fclose */
+
+ /* Make sure the file is flushed correctly. */
+ if (fflush(fp) == 0 && ferror(fp) == 0)
+ {
+ if (fclose(fp) == 0)
+ return 1;
+
+ error = errno; /* from fclose */
+ }
+
+ else
+ {
+ error = errno; /* from fflush or ferror */
+ (void)fclose(fp);
+ }
+
+ (void)remove(file_name);
+ /* The image has already been cleaned up; this is just used to
+ * set the error (because the original write succeeded).
+ */
+ return png_image_error(image, strerror(error));
+ }
+
+ else
+ {
+ /* Clean up: just the opened file. */
+ (void)fclose(fp);
+ (void)remove(file_name);
+ return 0;
+ }
+ }
+
+ else
+ return png_image_error(image, strerror(errno));
+ }
+
+ else
+ return png_image_error(image,
+ "png_image_write_to_file: invalid argument");
+ }
+
+ else if (image != NULL)
+ return png_image_error(image,
+ "png_image_write_to_file: incorrect PNG_IMAGE_VERSION");
+
+ else
+ return 0;
+}
+# endif /* STDIO */
+#endif /* SIMPLIFIED_WRITE */
+#endif /* WRITE */
diff --git a/third_party/lpng_v163/pngwtran.c b/third_party/libpng/pngwtran.c
similarity index 81%
rename from third_party/lpng_v163/pngwtran.c
rename to third_party/libpng/pngwtran.c
index 1fc3340..5dc9491 100644
--- a/third_party/lpng_v163/pngwtran.c
+++ b/third_party/libpng/pngwtran.c
@@ -1,636 +1,576 @@
-
-/* pngwtran.c - transforms the data in a row for PNG writers
- *
- * Last changed in libpng 1.6.0 [February 14, 2013]
- * Copyright (c) 1998-2013 Glenn Randers-Pehrson
- * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
- * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
- *
- * This code is released under the libpng license.
- * For conditions of distribution and use, see the disclaimer
- * and license in png.h
- */
-#include "pngpriv.h"
-
-#ifdef PNG_WRITE_SUPPORTED
-
-#ifdef PNG_WRITE_TRANSFORMS_SUPPORTED
-/* Transform the data according to the user's wishes. The order of
- * transformations is significant.
- */
-void /* PRIVATE */
-png_do_write_transformations(png_structrp png_ptr, png_row_infop row_info)
-{
- png_debug(1, "in png_do_write_transformations");
-
- if (png_ptr == NULL)
- return;
-
-#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
- if (png_ptr->transformations & PNG_USER_TRANSFORM)
- if (png_ptr->write_user_transform_fn != NULL)
- (*(png_ptr->write_user_transform_fn)) /* User write transform
- function */
- (png_ptr, /* png_ptr */
- row_info, /* row_info: */
- /* png_uint_32 width; width of row */
- /* png_size_t rowbytes; number of bytes in row */
- /* png_byte color_type; color type of pixels */
- /* png_byte bit_depth; bit depth of samples */
- /* png_byte channels; number of channels (1-4) */
- /* png_byte pixel_depth; bits per pixel (depth*channels) */
- png_ptr->row_buf + 1); /* start of pixel data for row */
-#endif
-
-#ifdef PNG_WRITE_FILLER_SUPPORTED
- if (png_ptr->transformations & PNG_FILLER)
- png_do_strip_channel(row_info, png_ptr->row_buf + 1,
- !(png_ptr->flags & PNG_FLAG_FILLER_AFTER));
-#endif
-
-#ifdef PNG_WRITE_PACKSWAP_SUPPORTED
- if (png_ptr->transformations & PNG_PACKSWAP)
- png_do_packswap(row_info, png_ptr->row_buf + 1);
-#endif
-
-#ifdef PNG_WRITE_PACK_SUPPORTED
- if (png_ptr->transformations & PNG_PACK)
- png_do_pack(row_info, png_ptr->row_buf + 1,
- (png_uint_32)png_ptr->bit_depth);
-#endif
-
-#ifdef PNG_WRITE_SWAP_SUPPORTED
- if (png_ptr->transformations & PNG_SWAP_BYTES)
- png_do_swap(row_info, png_ptr->row_buf + 1);
-#endif
-
-#ifdef PNG_WRITE_SHIFT_SUPPORTED
- if (png_ptr->transformations & PNG_SHIFT)
- png_do_shift(row_info, png_ptr->row_buf + 1,
- &(png_ptr->shift));
-#endif
-
-#ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED
- if (png_ptr->transformations & PNG_SWAP_ALPHA)
- png_do_write_swap_alpha(row_info, png_ptr->row_buf + 1);
-#endif
-
-#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
- if (png_ptr->transformations & PNG_INVERT_ALPHA)
- png_do_write_invert_alpha(row_info, png_ptr->row_buf + 1);
-#endif
-
-#ifdef PNG_WRITE_BGR_SUPPORTED
- if (png_ptr->transformations & PNG_BGR)
- png_do_bgr(row_info, png_ptr->row_buf + 1);
-#endif
-
-#ifdef PNG_WRITE_INVERT_SUPPORTED
- if (png_ptr->transformations & PNG_INVERT_MONO)
- png_do_invert(row_info, png_ptr->row_buf + 1);
-#endif
-}
-
-#ifdef PNG_WRITE_PACK_SUPPORTED
-/* Pack pixels into bytes. Pass the true bit depth in bit_depth. The
- * row_info bit depth should be 8 (one pixel per byte). The channels
- * should be 1 (this only happens on grayscale and paletted images).
- */
-void /* PRIVATE */
-png_do_pack(png_row_infop row_info, png_bytep row, png_uint_32 bit_depth)
-{
- png_debug(1, "in png_do_pack");
-
- if (row_info->bit_depth == 8 &&
- row_info->channels == 1)
- {
- switch ((int)bit_depth)
- {
- case 1:
- {
- png_bytep sp, dp;
- int mask, v;
- png_uint_32 i;
- png_uint_32 row_width = row_info->width;
-
- sp = row;
- dp = row;
- mask = 0x80;
- v = 0;
-
- for (i = 0; i < row_width; i++)
- {
- if (*sp != 0)
- v |= mask;
-
- sp++;
-
- if (mask > 1)
- mask >>= 1;
-
- else
- {
- mask = 0x80;
- *dp = (png_byte)v;
- dp++;
- v = 0;
- }
- }
-
- if (mask != 0x80)
- *dp = (png_byte)v;
-
- break;
- }
-
- case 2:
- {
- png_bytep sp, dp;
- int shift, v;
- png_uint_32 i;
- png_uint_32 row_width = row_info->width;
-
- sp = row;
- dp = row;
- shift = 6;
- v = 0;
-
- for (i = 0; i < row_width; i++)
- {
- png_byte value;
-
- value = (png_byte)(*sp & 0x03);
- v |= (value << shift);
-
- if (shift == 0)
- {
- shift = 6;
- *dp = (png_byte)v;
- dp++;
- v = 0;
- }
-
- else
- shift -= 2;
-
- sp++;
- }
-
- if (shift != 6)
- *dp = (png_byte)v;
-
- break;
- }
-
- case 4:
- {
- png_bytep sp, dp;
- int shift, v;
- png_uint_32 i;
- png_uint_32 row_width = row_info->width;
-
- sp = row;
- dp = row;
- shift = 4;
- v = 0;
-
- for (i = 0; i < row_width; i++)
- {
- png_byte value;
-
- value = (png_byte)(*sp & 0x0f);
- v |= (value << shift);
-
- if (shift == 0)
- {
- shift = 4;
- *dp = (png_byte)v;
- dp++;
- v = 0;
- }
-
- else
- shift -= 4;
-
- sp++;
- }
-
- if (shift != 4)
- *dp = (png_byte)v;
-
- break;
- }
-
- default:
- break;
- }
-
- row_info->bit_depth = (png_byte)bit_depth;
- row_info->pixel_depth = (png_byte)(bit_depth * row_info->channels);
- row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth,
- row_info->width);
- }
-}
-#endif
-
-#ifdef PNG_WRITE_SHIFT_SUPPORTED
-/* Shift pixel values to take advantage of whole range. Pass the
- * true number of bits in bit_depth. The row should be packed
- * according to row_info->bit_depth. Thus, if you had a row of
- * bit depth 4, but the pixels only had values from 0 to 7, you
- * would pass 3 as bit_depth, and this routine would translate the
- * data to 0 to 15.
- */
-void /* PRIVATE */
-png_do_shift(png_row_infop row_info, png_bytep row,
- png_const_color_8p bit_depth)
-{
- png_debug(1, "in png_do_shift");
-
- if (row_info->color_type != PNG_COLOR_TYPE_PALETTE)
- {
- int shift_start[4], shift_dec[4];
- int channels = 0;
-
- if (row_info->color_type & PNG_COLOR_MASK_COLOR)
- {
- shift_start[channels] = row_info->bit_depth - bit_depth->red;
- shift_dec[channels] = bit_depth->red;
- channels++;
-
- shift_start[channels] = row_info->bit_depth - bit_depth->green;
- shift_dec[channels] = bit_depth->green;
- channels++;
-
- shift_start[channels] = row_info->bit_depth - bit_depth->blue;
- shift_dec[channels] = bit_depth->blue;
- channels++;
- }
-
- else
- {
- shift_start[channels] = row_info->bit_depth - bit_depth->gray;
- shift_dec[channels] = bit_depth->gray;
- channels++;
- }
-
- if (row_info->color_type & PNG_COLOR_MASK_ALPHA)
- {
- shift_start[channels] = row_info->bit_depth - bit_depth->alpha;
- shift_dec[channels] = bit_depth->alpha;
- channels++;
- }
-
- /* With low row depths, could only be grayscale, so one channel */
- if (row_info->bit_depth < 8)
- {
- png_bytep bp = row;
- png_size_t i;
- unsigned int mask;
- png_size_t row_bytes = row_info->rowbytes;
-
- if (bit_depth->gray == 1 && row_info->bit_depth == 2)
- mask = 0x55;
-
- else if (row_info->bit_depth == 4 && bit_depth->gray == 3)
- mask = 0x11;
-
- else
- mask = 0xff;
-
- for (i = 0; i < row_bytes; i++, bp++)
- {
- int j;
- unsigned int v, out;
-
- v = *bp;
- out = 0;
-
- for (j = shift_start[0]; j > -shift_dec[0]; j -= shift_dec[0])
- {
- if (j > 0)
- out |= v << j;
-
- else
- out |= (v >> (-j)) & mask;
- }
-
- *bp = (png_byte)(out & 0xff);
- }
- }
-
- else if (row_info->bit_depth == 8)
- {
- png_bytep bp = row;
- png_uint_32 i;
- png_uint_32 istop = channels * row_info->width;
-
- for (i = 0; i < istop; i++, bp++)
- {
-
- const unsigned int c = i%channels;
- int j;
- unsigned int v, out;
-
- v = *bp;
- out = 0;
-
- for (j = shift_start[c]; j > -shift_dec[c]; j -= shift_dec[c])
- {
- if (j > 0)
- out |= v << j;
-
- else
- out |= v >> (-j);
- }
-
- *bp = (png_byte)(out & 0xff);
- }
- }
-
- else
- {
- png_bytep bp;
- png_uint_32 i;
- png_uint_32 istop = channels * row_info->width;
-
- for (bp = row, i = 0; i < istop; i++)
- {
- const unsigned int c = i%channels;
- int j;
- unsigned int value, v;
-
- v = png_get_uint_16(bp);
- value = 0;
-
- for (j = shift_start[c]; j > -shift_dec[c]; j -= shift_dec[c])
- {
- if (j > 0)
- value |= v << j;
-
- else
- value |= v >> (-j);
- }
- *bp++ = (png_byte)((value >> 8) & 0xff);
- *bp++ = (png_byte)(value & 0xff);
- }
- }
- }
-}
-#endif
-
-#ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED
-void /* PRIVATE */
-png_do_write_swap_alpha(png_row_infop row_info, png_bytep row)
-{
- png_debug(1, "in png_do_write_swap_alpha");
-
- {
- if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
- {
- if (row_info->bit_depth == 8)
- {
- /* This converts from ARGB to RGBA */
- png_bytep sp, dp;
- png_uint_32 i;
- png_uint_32 row_width = row_info->width;
-
- for (i = 0, sp = dp = row; i < row_width; i++)
- {
- png_byte save = *(sp++);
- *(dp++) = *(sp++);
- *(dp++) = *(sp++);
- *(dp++) = *(sp++);
- *(dp++) = save;
- }
- }
-
-#ifdef PNG_WRITE_16BIT_SUPPORTED
- else
- {
- /* This converts from AARRGGBB to RRGGBBAA */
- png_bytep sp, dp;
- png_uint_32 i;
- png_uint_32 row_width = row_info->width;
-
- for (i = 0, sp = dp = row; i < row_width; i++)
- {
- png_byte save[2];
- save[0] = *(sp++);
- save[1] = *(sp++);
- *(dp++) = *(sp++);
- *(dp++) = *(sp++);
- *(dp++) = *(sp++);
- *(dp++) = *(sp++);
- *(dp++) = *(sp++);
- *(dp++) = *(sp++);
- *(dp++) = save[0];
- *(dp++) = save[1];
- }
- }
-#endif /* PNG_WRITE_16BIT_SUPPORTED */
- }
-
- else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
- {
- if (row_info->bit_depth == 8)
- {
- /* This converts from AG to GA */
- png_bytep sp, dp;
- png_uint_32 i;
- png_uint_32 row_width = row_info->width;
-
- for (i = 0, sp = dp = row; i < row_width; i++)
- {
- png_byte save = *(sp++);
- *(dp++) = *(sp++);
- *(dp++) = save;
- }
- }
-
-#ifdef PNG_WRITE_16BIT_SUPPORTED
- else
- {
- /* This converts from AAGG to GGAA */
- png_bytep sp, dp;
- png_uint_32 i;
- png_uint_32 row_width = row_info->width;
-
- for (i = 0, sp = dp = row; i < row_width; i++)
- {
- png_byte save[2];
- save[0] = *(sp++);
- save[1] = *(sp++);
- *(dp++) = *(sp++);
- *(dp++) = *(sp++);
- *(dp++) = save[0];
- *(dp++) = save[1];
- }
- }
-#endif /* PNG_WRITE_16BIT_SUPPORTED */
- }
- }
-}
-#endif
-
-#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
-void /* PRIVATE */
-png_do_write_invert_alpha(png_row_infop row_info, png_bytep row)
-{
- png_debug(1, "in png_do_write_invert_alpha");
-
- {
- if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
- {
- if (row_info->bit_depth == 8)
- {
- /* This inverts the alpha channel in RGBA */
- png_bytep sp, dp;
- png_uint_32 i;
- png_uint_32 row_width = row_info->width;
-
- for (i = 0, sp = dp = row; i < row_width; i++)
- {
- /* Does nothing
- *(dp++) = *(sp++);
- *(dp++) = *(sp++);
- *(dp++) = *(sp++);
- */
- sp+=3; dp = sp;
- *(dp++) = (png_byte)(255 - *(sp++));
- }
- }
-
-#ifdef PNG_WRITE_16BIT_SUPPORTED
- else
- {
- /* This inverts the alpha channel in RRGGBBAA */
- png_bytep sp, dp;
- png_uint_32 i;
- png_uint_32 row_width = row_info->width;
-
- for (i = 0, sp = dp = row; i < row_width; i++)
- {
- /* Does nothing
- *(dp++) = *(sp++);
- *(dp++) = *(sp++);
- *(dp++) = *(sp++);
- *(dp++) = *(sp++);
- *(dp++) = *(sp++);
- *(dp++) = *(sp++);
- */
- sp+=6; dp = sp;
- *(dp++) = (png_byte)(255 - *(sp++));
- *(dp++) = (png_byte)(255 - *(sp++));
- }
- }
-#endif /* PNG_WRITE_16BIT_SUPPORTED */
- }
-
- else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
- {
- if (row_info->bit_depth == 8)
- {
- /* This inverts the alpha channel in GA */
- png_bytep sp, dp;
- png_uint_32 i;
- png_uint_32 row_width = row_info->width;
-
- for (i = 0, sp = dp = row; i < row_width; i++)
- {
- *(dp++) = *(sp++);
- *(dp++) = (png_byte)(255 - *(sp++));
- }
- }
-
-#ifdef PNG_WRITE_16BIT_SUPPORTED
- else
- {
- /* This inverts the alpha channel in GGAA */
- png_bytep sp, dp;
- png_uint_32 i;
- png_uint_32 row_width = row_info->width;
-
- for (i = 0, sp = dp = row; i < row_width; i++)
- {
- /* Does nothing
- *(dp++) = *(sp++);
- *(dp++) = *(sp++);
- */
- sp+=2; dp = sp;
- *(dp++) = (png_byte)(255 - *(sp++));
- *(dp++) = (png_byte)(255 - *(sp++));
- }
- }
-#endif /* PNG_WRITE_16BIT_SUPPORTED */
- }
- }
-}
-#endif
-#endif /* PNG_WRITE_TRANSFORMS_SUPPORTED */
-
-#ifdef PNG_MNG_FEATURES_SUPPORTED
-/* Undoes intrapixel differencing */
-void /* PRIVATE */
-png_do_write_intrapixel(png_row_infop row_info, png_bytep row)
-{
- png_debug(1, "in png_do_write_intrapixel");
-
- if ((row_info->color_type & PNG_COLOR_MASK_COLOR))
- {
- int bytes_per_pixel;
- png_uint_32 row_width = row_info->width;
- if (row_info->bit_depth == 8)
- {
- png_bytep rp;
- png_uint_32 i;
-
- if (row_info->color_type == PNG_COLOR_TYPE_RGB)
- bytes_per_pixel = 3;
-
- else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
- bytes_per_pixel = 4;
-
- else
- return;
-
- for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel)
- {
- *(rp) = (png_byte)((*rp - *(rp + 1)) & 0xff);
- *(rp + 2) = (png_byte)((*(rp + 2) - *(rp + 1)) & 0xff);
- }
- }
-
-#ifdef PNG_WRITE_16BIT_SUPPORTED
- else if (row_info->bit_depth == 16)
- {
- png_bytep rp;
- png_uint_32 i;
-
- if (row_info->color_type == PNG_COLOR_TYPE_RGB)
- bytes_per_pixel = 6;
-
- else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
- bytes_per_pixel = 8;
-
- else
- return;
-
- for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel)
- {
- png_uint_32 s0 = (*(rp ) << 8) | *(rp + 1);
- png_uint_32 s1 = (*(rp + 2) << 8) | *(rp + 3);
- png_uint_32 s2 = (*(rp + 4) << 8) | *(rp + 5);
- png_uint_32 red = (png_uint_32)((s0 - s1) & 0xffffL);
- png_uint_32 blue = (png_uint_32)((s2 - s1) & 0xffffL);
- *(rp ) = (png_byte)((red >> 8) & 0xff);
- *(rp + 1) = (png_byte)(red & 0xff);
- *(rp + 4) = (png_byte)((blue >> 8) & 0xff);
- *(rp + 5) = (png_byte)(blue & 0xff);
- }
- }
-#endif /* PNG_WRITE_16BIT_SUPPORTED */
- }
-}
-#endif /* PNG_MNG_FEATURES_SUPPORTED */
-#endif /* PNG_WRITE_SUPPORTED */
+
+/* pngwtran.c - transforms the data in a row for PNG writers
+ *
+ * Last changed in libpng 1.6.18 [July 23, 2015]
+ * Copyright (c) 1998-2015 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+
+#include "pngpriv.h"
+
+#ifdef PNG_WRITE_SUPPORTED
+#ifdef PNG_WRITE_TRANSFORMS_SUPPORTED
+
+#ifdef PNG_WRITE_PACK_SUPPORTED
+/* Pack pixels into bytes. Pass the true bit depth in bit_depth. The
+ * row_info bit depth should be 8 (one pixel per byte). The channels
+ * should be 1 (this only happens on grayscale and paletted images).
+ */
+static void
+png_do_pack(png_row_infop row_info, png_bytep row, png_uint_32 bit_depth)
+{
+ png_debug(1, "in png_do_pack");
+
+ if (row_info->bit_depth == 8 &&
+ row_info->channels == 1)
+ {
+ switch ((int)bit_depth)
+ {
+ case 1:
+ {
+ png_bytep sp, dp;
+ int mask, v;
+ png_uint_32 i;
+ png_uint_32 row_width = row_info->width;
+
+ sp = row;
+ dp = row;
+ mask = 0x80;
+ v = 0;
+
+ for (i = 0; i < row_width; i++)
+ {
+ if (*sp != 0)
+ v |= mask;
+
+ sp++;
+
+ if (mask > 1)
+ mask >>= 1;
+
+ else
+ {
+ mask = 0x80;
+ *dp = (png_byte)v;
+ dp++;
+ v = 0;
+ }
+ }
+
+ if (mask != 0x80)
+ *dp = (png_byte)v;
+
+ break;
+ }
+
+ case 2:
+ {
+ png_bytep sp, dp;
+ unsigned int shift;
+ int v;
+ png_uint_32 i;
+ png_uint_32 row_width = row_info->width;
+
+ sp = row;
+ dp = row;
+ shift = 6;
+ v = 0;
+
+ for (i = 0; i < row_width; i++)
+ {
+ png_byte value;
+
+ value = (png_byte)(*sp & 0x03);
+ v |= (value << shift);
+
+ if (shift == 0)
+ {
+ shift = 6;
+ *dp = (png_byte)v;
+ dp++;
+ v = 0;
+ }
+
+ else
+ shift -= 2;
+
+ sp++;
+ }
+
+ if (shift != 6)
+ *dp = (png_byte)v;
+
+ break;
+ }
+
+ case 4:
+ {
+ png_bytep sp, dp;
+ unsigned int shift;
+ int v;
+ png_uint_32 i;
+ png_uint_32 row_width = row_info->width;
+
+ sp = row;
+ dp = row;
+ shift = 4;
+ v = 0;
+
+ for (i = 0; i < row_width; i++)
+ {
+ png_byte value;
+
+ value = (png_byte)(*sp & 0x0f);
+ v |= (value << shift);
+
+ if (shift == 0)
+ {
+ shift = 4;
+ *dp = (png_byte)v;
+ dp++;
+ v = 0;
+ }
+
+ else
+ shift -= 4;
+
+ sp++;
+ }
+
+ if (shift != 4)
+ *dp = (png_byte)v;
+
+ break;
+ }
+
+ default:
+ break;
+ }
+
+ row_info->bit_depth = (png_byte)bit_depth;
+ row_info->pixel_depth = (png_byte)(bit_depth * row_info->channels);
+ row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth,
+ row_info->width);
+ }
+}
+#endif
+
+#ifdef PNG_WRITE_SHIFT_SUPPORTED
+/* Shift pixel values to take advantage of whole range. Pass the
+ * true number of bits in bit_depth. The row should be packed
+ * according to row_info->bit_depth. Thus, if you had a row of
+ * bit depth 4, but the pixels only had values from 0 to 7, you
+ * would pass 3 as bit_depth, and this routine would translate the
+ * data to 0 to 15.
+ */
+static void
+png_do_shift(png_row_infop row_info, png_bytep row,
+ png_const_color_8p bit_depth)
+{
+ png_debug(1, "in png_do_shift");
+
+ if (row_info->color_type != PNG_COLOR_TYPE_PALETTE)
+ {
+ int shift_start[4], shift_dec[4];
+ int channels = 0;
+
+ if ((row_info->color_type & PNG_COLOR_MASK_COLOR) != 0)
+ {
+ shift_start[channels] = row_info->bit_depth - bit_depth->red;
+ shift_dec[channels] = bit_depth->red;
+ channels++;
+
+ shift_start[channels] = row_info->bit_depth - bit_depth->green;
+ shift_dec[channels] = bit_depth->green;
+ channels++;
+
+ shift_start[channels] = row_info->bit_depth - bit_depth->blue;
+ shift_dec[channels] = bit_depth->blue;
+ channels++;
+ }
+
+ else
+ {
+ shift_start[channels] = row_info->bit_depth - bit_depth->gray;
+ shift_dec[channels] = bit_depth->gray;
+ channels++;
+ }
+
+ if ((row_info->color_type & PNG_COLOR_MASK_ALPHA) != 0)
+ {
+ shift_start[channels] = row_info->bit_depth - bit_depth->alpha;
+ shift_dec[channels] = bit_depth->alpha;
+ channels++;
+ }
+
+ /* With low row depths, could only be grayscale, so one channel */
+ if (row_info->bit_depth < 8)
+ {
+ png_bytep bp = row;
+ png_size_t i;
+ unsigned int mask;
+ png_size_t row_bytes = row_info->rowbytes;
+
+ if (bit_depth->gray == 1 && row_info->bit_depth == 2)
+ mask = 0x55;
+
+ else if (row_info->bit_depth == 4 && bit_depth->gray == 3)
+ mask = 0x11;
+
+ else
+ mask = 0xff;
+
+ for (i = 0; i < row_bytes; i++, bp++)
+ {
+ int j;
+ unsigned int v, out;
+
+ v = *bp;
+ out = 0;
+
+ for (j = shift_start[0]; j > -shift_dec[0]; j -= shift_dec[0])
+ {
+ if (j > 0)
+ out |= v << j;
+
+ else
+ out |= (v >> (-j)) & mask;
+ }
+
+ *bp = (png_byte)(out & 0xff);
+ }
+ }
+
+ else if (row_info->bit_depth == 8)
+ {
+ png_bytep bp = row;
+ png_uint_32 i;
+ png_uint_32 istop = channels * row_info->width;
+
+ for (i = 0; i < istop; i++, bp++)
+ {
+
+ const unsigned int c = i%channels;
+ int j;
+ unsigned int v, out;
+
+ v = *bp;
+ out = 0;
+
+ for (j = shift_start[c]; j > -shift_dec[c]; j -= shift_dec[c])
+ {
+ if (j > 0)
+ out |= v << j;
+
+ else
+ out |= v >> (-j);
+ }
+
+ *bp = (png_byte)(out & 0xff);
+ }
+ }
+
+ else
+ {
+ png_bytep bp;
+ png_uint_32 i;
+ png_uint_32 istop = channels * row_info->width;
+
+ for (bp = row, i = 0; i < istop; i++)
+ {
+ const unsigned int c = i%channels;
+ int j;
+ unsigned int value, v;
+
+ v = png_get_uint_16(bp);
+ value = 0;
+
+ for (j = shift_start[c]; j > -shift_dec[c]; j -= shift_dec[c])
+ {
+ if (j > 0)
+ value |= v << j;
+
+ else
+ value |= v >> (-j);
+ }
+ *bp++ = (png_byte)((value >> 8) & 0xff);
+ *bp++ = (png_byte)(value & 0xff);
+ }
+ }
+ }
+}
+#endif
+
+#ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED
+static void
+png_do_write_swap_alpha(png_row_infop row_info, png_bytep row)
+{
+ png_debug(1, "in png_do_write_swap_alpha");
+
+ {
+ if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+ {
+ if (row_info->bit_depth == 8)
+ {
+ /* This converts from ARGB to RGBA */
+ png_bytep sp, dp;
+ png_uint_32 i;
+ png_uint_32 row_width = row_info->width;
+
+ for (i = 0, sp = dp = row; i < row_width; i++)
+ {
+ png_byte save = *(sp++);
+ *(dp++) = *(sp++);
+ *(dp++) = *(sp++);
+ *(dp++) = *(sp++);
+ *(dp++) = save;
+ }
+ }
+
+#ifdef PNG_WRITE_16BIT_SUPPORTED
+ else
+ {
+ /* This converts from AARRGGBB to RRGGBBAA */
+ png_bytep sp, dp;
+ png_uint_32 i;
+ png_uint_32 row_width = row_info->width;
+
+ for (i = 0, sp = dp = row; i < row_width; i++)
+ {
+ png_byte save[2];
+ save[0] = *(sp++);
+ save[1] = *(sp++);
+ *(dp++) = *(sp++);
+ *(dp++) = *(sp++);
+ *(dp++) = *(sp++);
+ *(dp++) = *(sp++);
+ *(dp++) = *(sp++);
+ *(dp++) = *(sp++);
+ *(dp++) = save[0];
+ *(dp++) = save[1];
+ }
+ }
+#endif /* WRITE_16BIT */
+ }
+
+ else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+ {
+ if (row_info->bit_depth == 8)
+ {
+ /* This converts from AG to GA */
+ png_bytep sp, dp;
+ png_uint_32 i;
+ png_uint_32 row_width = row_info->width;
+
+ for (i = 0, sp = dp = row; i < row_width; i++)
+ {
+ png_byte save = *(sp++);
+ *(dp++) = *(sp++);
+ *(dp++) = save;
+ }
+ }
+
+#ifdef PNG_WRITE_16BIT_SUPPORTED
+ else
+ {
+ /* This converts from AAGG to GGAA */
+ png_bytep sp, dp;
+ png_uint_32 i;
+ png_uint_32 row_width = row_info->width;
+
+ for (i = 0, sp = dp = row; i < row_width; i++)
+ {
+ png_byte save[2];
+ save[0] = *(sp++);
+ save[1] = *(sp++);
+ *(dp++) = *(sp++);
+ *(dp++) = *(sp++);
+ *(dp++) = save[0];
+ *(dp++) = save[1];
+ }
+ }
+#endif /* WRITE_16BIT */
+ }
+ }
+}
+#endif
+
+#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
+static void
+png_do_write_invert_alpha(png_row_infop row_info, png_bytep row)
+{
+ png_debug(1, "in png_do_write_invert_alpha");
+
+ {
+ if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+ {
+ if (row_info->bit_depth == 8)
+ {
+ /* This inverts the alpha channel in RGBA */
+ png_bytep sp, dp;
+ png_uint_32 i;
+ png_uint_32 row_width = row_info->width;
+
+ for (i = 0, sp = dp = row; i < row_width; i++)
+ {
+ /* Does nothing
+ *(dp++) = *(sp++);
+ *(dp++) = *(sp++);
+ *(dp++) = *(sp++);
+ */
+ sp+=3; dp = sp;
+ *dp = (png_byte)(255 - *(sp++));
+ }
+ }
+
+#ifdef PNG_WRITE_16BIT_SUPPORTED
+ else
+ {
+ /* This inverts the alpha channel in RRGGBBAA */
+ png_bytep sp, dp;
+ png_uint_32 i;
+ png_uint_32 row_width = row_info->width;
+
+ for (i = 0, sp = dp = row; i < row_width; i++)
+ {
+ /* Does nothing
+ *(dp++) = *(sp++);
+ *(dp++) = *(sp++);
+ *(dp++) = *(sp++);
+ *(dp++) = *(sp++);
+ *(dp++) = *(sp++);
+ *(dp++) = *(sp++);
+ */
+ sp+=6; dp = sp;
+ *(dp++) = (png_byte)(255 - *(sp++));
+ *dp = (png_byte)(255 - *(sp++));
+ }
+ }
+#endif /* WRITE_16BIT */
+ }
+
+ else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+ {
+ if (row_info->bit_depth == 8)
+ {
+ /* This inverts the alpha channel in GA */
+ png_bytep sp, dp;
+ png_uint_32 i;
+ png_uint_32 row_width = row_info->width;
+
+ for (i = 0, sp = dp = row; i < row_width; i++)
+ {
+ *(dp++) = *(sp++);
+ *(dp++) = (png_byte)(255 - *(sp++));
+ }
+ }
+
+#ifdef PNG_WRITE_16BIT_SUPPORTED
+ else
+ {
+ /* This inverts the alpha channel in GGAA */
+ png_bytep sp, dp;
+ png_uint_32 i;
+ png_uint_32 row_width = row_info->width;
+
+ for (i = 0, sp = dp = row; i < row_width; i++)
+ {
+ /* Does nothing
+ *(dp++) = *(sp++);
+ *(dp++) = *(sp++);
+ */
+ sp+=2; dp = sp;
+ *(dp++) = (png_byte)(255 - *(sp++));
+ *dp = (png_byte)(255 - *(sp++));
+ }
+ }
+#endif /* WRITE_16BIT */
+ }
+ }
+}
+#endif
+
+/* Transform the data according to the user's wishes. The order of
+ * transformations is significant.
+ */
+void /* PRIVATE */
+png_do_write_transformations(png_structrp png_ptr, png_row_infop row_info)
+{
+ png_debug(1, "in png_do_write_transformations");
+
+ if (png_ptr == NULL)
+ return;
+
+#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
+ if ((png_ptr->transformations & PNG_USER_TRANSFORM) != 0)
+ if (png_ptr->write_user_transform_fn != NULL)
+ (*(png_ptr->write_user_transform_fn)) /* User write transform
+ function */
+ (png_ptr, /* png_ptr */
+ row_info, /* row_info: */
+ /* png_uint_32 width; width of row */
+ /* png_size_t rowbytes; number of bytes in row */
+ /* png_byte color_type; color type of pixels */
+ /* png_byte bit_depth; bit depth of samples */
+ /* png_byte channels; number of channels (1-4) */
+ /* png_byte pixel_depth; bits per pixel (depth*channels) */
+ png_ptr->row_buf + 1); /* start of pixel data for row */
+#endif
+
+#ifdef PNG_WRITE_FILLER_SUPPORTED
+ if ((png_ptr->transformations & PNG_FILLER) != 0)
+ png_do_strip_channel(row_info, png_ptr->row_buf + 1,
+ !(png_ptr->flags & PNG_FLAG_FILLER_AFTER));
+#endif
+
+#ifdef PNG_WRITE_PACKSWAP_SUPPORTED
+ if ((png_ptr->transformations & PNG_PACKSWAP) != 0)
+ png_do_packswap(row_info, png_ptr->row_buf + 1);
+#endif
+
+#ifdef PNG_WRITE_PACK_SUPPORTED
+ if ((png_ptr->transformations & PNG_PACK) != 0)
+ png_do_pack(row_info, png_ptr->row_buf + 1,
+ (png_uint_32)png_ptr->bit_depth);
+#endif
+
+#ifdef PNG_WRITE_SWAP_SUPPORTED
+# ifdef PNG_16BIT_SUPPORTED
+ if ((png_ptr->transformations & PNG_SWAP_BYTES) != 0)
+ png_do_swap(row_info, png_ptr->row_buf + 1);
+# endif
+#endif
+
+#ifdef PNG_WRITE_SHIFT_SUPPORTED
+ if ((png_ptr->transformations & PNG_SHIFT) != 0)
+ png_do_shift(row_info, png_ptr->row_buf + 1,
+ &(png_ptr->shift));
+#endif
+
+#ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED
+ if ((png_ptr->transformations & PNG_SWAP_ALPHA) != 0)
+ png_do_write_swap_alpha(row_info, png_ptr->row_buf + 1);
+#endif
+
+#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
+ if ((png_ptr->transformations & PNG_INVERT_ALPHA) != 0)
+ png_do_write_invert_alpha(row_info, png_ptr->row_buf + 1);
+#endif
+
+#ifdef PNG_WRITE_BGR_SUPPORTED
+ if ((png_ptr->transformations & PNG_BGR) != 0)
+ png_do_bgr(row_info, png_ptr->row_buf + 1);
+#endif
+
+#ifdef PNG_WRITE_INVERT_SUPPORTED
+ if ((png_ptr->transformations & PNG_INVERT_MONO) != 0)
+ png_do_invert(row_info, png_ptr->row_buf + 1);
+#endif
+}
+#endif /* WRITE_TRANSFORMS */
+#endif /* WRITE */
diff --git a/third_party/lpng_v163/pngwutil.c b/third_party/libpng/pngwutil.c
similarity index 77%
rename from third_party/lpng_v163/pngwutil.c
rename to third_party/libpng/pngwutil.c
index dd5d659..0ee102b 100644
--- a/third_party/lpng_v163/pngwutil.c
+++ b/third_party/libpng/pngwutil.c
@@ -1,3022 +1,2709 @@
-
-/* pngwutil.c - utilities to write a PNG file
- *
- * Last changed in libpng 1.6.2 [April 25, 2013]
- * Copyright (c) 1998-2013 Glenn Randers-Pehrson
- * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
- * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
- *
- * This code is released under the libpng license.
- * For conditions of distribution and use, see the disclaimer
- * and license in png.h
- */
-#include "pngpriv.h"
-
-#ifdef PNG_WRITE_SUPPORTED
-
-#ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED
-/* Place a 32-bit number into a buffer in PNG byte order. We work
- * with unsigned numbers for convenience, although one supported
- * ancillary chunk uses signed (two's complement) numbers.
- */
-void PNGAPI
-png_save_uint_32(png_bytep buf, png_uint_32 i)
-{
- buf[0] = (png_byte)((i >> 24) & 0xff);
- buf[1] = (png_byte)((i >> 16) & 0xff);
- buf[2] = (png_byte)((i >> 8) & 0xff);
- buf[3] = (png_byte)(i & 0xff);
-}
-
-/* Place a 16-bit number into a buffer in PNG byte order.
- * The parameter is declared unsigned int, not png_uint_16,
- * just to avoid potential problems on pre-ANSI C compilers.
- */
-void PNGAPI
-png_save_uint_16(png_bytep buf, unsigned int i)
-{
- buf[0] = (png_byte)((i >> 8) & 0xff);
- buf[1] = (png_byte)(i & 0xff);
-}
-#endif
-
-/* Simple function to write the signature. If we have already written
- * the magic bytes of the signature, or more likely, the PNG stream is
- * being embedded into another stream and doesn't need its own signature,
- * we should call png_set_sig_bytes() to tell libpng how many of the
- * bytes have already been written.
- */
-void PNGAPI
-png_write_sig(png_structrp png_ptr)
-{
- png_byte png_signature[8] = {137, 80, 78, 71, 13, 10, 26, 10};
-
-#ifdef PNG_IO_STATE_SUPPORTED
- /* Inform the I/O callback that the signature is being written */
- png_ptr->io_state = PNG_IO_WRITING | PNG_IO_SIGNATURE;
-#endif
-
- /* Write the rest of the 8 byte signature */
- png_write_data(png_ptr, &png_signature[png_ptr->sig_bytes],
- (png_size_t)(8 - png_ptr->sig_bytes));
-
- if (png_ptr->sig_bytes < 3)
- png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE;
-}
-
-/* Write the start of a PNG chunk. The type is the chunk type.
- * The total_length is the sum of the lengths of all the data you will be
- * passing in png_write_chunk_data().
- */
-static void
-png_write_chunk_header(png_structrp png_ptr, png_uint_32 chunk_name,
- png_uint_32 length)
-{
- png_byte buf[8];
-
-#if defined(PNG_DEBUG) && (PNG_DEBUG > 0)
- PNG_CSTRING_FROM_CHUNK(buf, chunk_name);
- png_debug2(0, "Writing %s chunk, length = %lu", buf, (unsigned long)length);
-#endif
-
- if (png_ptr == NULL)
- return;
-
-#ifdef PNG_IO_STATE_SUPPORTED
- /* Inform the I/O callback that the chunk header is being written.
- * PNG_IO_CHUNK_HDR requires a single I/O call.
- */
- png_ptr->io_state = PNG_IO_WRITING | PNG_IO_CHUNK_HDR;
-#endif
-
- /* Write the length and the chunk name */
- png_save_uint_32(buf, length);
- png_save_uint_32(buf + 4, chunk_name);
- png_write_data(png_ptr, buf, 8);
-
- /* Put the chunk name into png_ptr->chunk_name */
- png_ptr->chunk_name = chunk_name;
-
- /* Reset the crc and run it over the chunk name */
- png_reset_crc(png_ptr);
-
- png_calculate_crc(png_ptr, buf + 4, 4);
-
-#ifdef PNG_IO_STATE_SUPPORTED
- /* Inform the I/O callback that chunk data will (possibly) be written.
- * PNG_IO_CHUNK_DATA does NOT require a specific number of I/O calls.
- */
- png_ptr->io_state = PNG_IO_WRITING | PNG_IO_CHUNK_DATA;
-#endif
-}
-
-void PNGAPI
-png_write_chunk_start(png_structrp png_ptr, png_const_bytep chunk_string,
- png_uint_32 length)
-{
- png_write_chunk_header(png_ptr, PNG_CHUNK_FROM_STRING(chunk_string), length);
-}
-
-/* Write the data of a PNG chunk started with png_write_chunk_header().
- * Note that multiple calls to this function are allowed, and that the
- * sum of the lengths from these calls *must* add up to the total_length
- * given to png_write_chunk_header().
- */
-void PNGAPI
-png_write_chunk_data(png_structrp png_ptr, png_const_bytep data,
- png_size_t length)
-{
- /* Write the data, and run the CRC over it */
- if (png_ptr == NULL)
- return;
-
- if (data != NULL && length > 0)
- {
- png_write_data(png_ptr, data, length);
-
- /* Update the CRC after writing the data,
- * in case that the user I/O routine alters it.
- */
- png_calculate_crc(png_ptr, data, length);
- }
-}
-
-/* Finish a chunk started with png_write_chunk_header(). */
-void PNGAPI
-png_write_chunk_end(png_structrp png_ptr)
-{
- png_byte buf[4];
-
- if (png_ptr == NULL) return;
-
-#ifdef PNG_IO_STATE_SUPPORTED
- /* Inform the I/O callback that the chunk CRC is being written.
- * PNG_IO_CHUNK_CRC requires a single I/O function call.
- */
- png_ptr->io_state = PNG_IO_WRITING | PNG_IO_CHUNK_CRC;
-#endif
-
- /* Write the crc in a single operation */
- png_save_uint_32(buf, png_ptr->crc);
-
- png_write_data(png_ptr, buf, (png_size_t)4);
-}
-
-/* Write a PNG chunk all at once. The type is an array of ASCII characters
- * representing the chunk name. The array must be at least 4 bytes in
- * length, and does not need to be null terminated. To be safe, pass the
- * pre-defined chunk names here, and if you need a new one, define it
- * where the others are defined. The length is the length of the data.
- * All the data must be present. If that is not possible, use the
- * png_write_chunk_start(), png_write_chunk_data(), and png_write_chunk_end()
- * functions instead.
- */
-static void
-png_write_complete_chunk(png_structrp png_ptr, png_uint_32 chunk_name,
- png_const_bytep data, png_size_t length)
-{
- if (png_ptr == NULL)
- return;
-
- /* On 64 bit architectures 'length' may not fit in a png_uint_32. */
- if (length > PNG_UINT_31_MAX)
- png_error(png_ptr, "length exceeds PNG maxima");
-
- png_write_chunk_header(png_ptr, chunk_name, (png_uint_32)length);
- png_write_chunk_data(png_ptr, data, length);
- png_write_chunk_end(png_ptr);
-}
-
-/* This is the API that calls the internal function above. */
-void PNGAPI
-png_write_chunk(png_structrp png_ptr, png_const_bytep chunk_string,
- png_const_bytep data, png_size_t length)
-{
- png_write_complete_chunk(png_ptr, PNG_CHUNK_FROM_STRING(chunk_string), data,
- length);
-}
-
-/* This is used below to find the size of an image to pass to png_deflate_claim,
- * so it only needs to be accurate if the size is less than 16384 bytes (the
- * point at which a lower LZ window size can be used.)
- */
-static png_alloc_size_t
-png_image_size(png_structrp png_ptr)
-{
- /* Only return sizes up to the maximum of a png_uint_32, do this by limiting
- * the width and height used to 15 bits.
- */
- png_uint_32 h = png_ptr->height;
-
- if (png_ptr->rowbytes < 32768 && h < 32768)
- {
- if (png_ptr->interlaced)
- {
- /* Interlacing makes the image larger because of the replication of
- * both the filter byte and the padding to a byte boundary.
- */
- png_uint_32 w = png_ptr->width;
- unsigned int pd = png_ptr->pixel_depth;
- png_alloc_size_t cb_base;
- int pass;
-
- for (cb_base=0, pass=0; pass<=6; ++pass)
- {
- png_uint_32 pw = PNG_PASS_COLS(w, pass);
-
- if (pw > 0)
- cb_base += (PNG_ROWBYTES(pd, pw)+1) * PNG_PASS_ROWS(h, pass);
- }
-
- return cb_base;
- }
-
- else
- return (png_ptr->rowbytes+1) * h;
- }
-
- else
- return 0xffffffffU;
-}
-
-#ifdef PNG_WRITE_OPTIMIZE_CMF_SUPPORTED
- /* This is the code to hack the first two bytes of the deflate stream (the
- * deflate header) to correct the windowBits value to match the actual data
- * size. Note that the second argument is the *uncompressed* size but the
- * first argument is the *compressed* data (and it must be deflate
- * compressed.)
- */
-static void
-optimize_cmf(png_bytep data, png_alloc_size_t data_size)
-{
- /* Optimize the CMF field in the zlib stream. The resultant zlib stream is
- * still compliant to the stream specification.
- */
- if (data_size <= 16384) /* else windowBits must be 15 */
- {
- unsigned int z_cmf = data[0]; /* zlib compression method and flags */
-
- if ((z_cmf & 0x0f) == 8 && (z_cmf & 0xf0) <= 0x70)
- {
- unsigned int z_cinfo;
- unsigned int half_z_window_size;
-
- z_cinfo = z_cmf >> 4;
- half_z_window_size = 1U << (z_cinfo + 7);
-
- if (data_size <= half_z_window_size) /* else no change */
- {
- unsigned int tmp;
-
- do
- {
- half_z_window_size >>= 1;
- --z_cinfo;
- }
- while (z_cinfo > 0 && data_size <= half_z_window_size);
-
- z_cmf = (z_cmf & 0x0f) | (z_cinfo << 4);
-
- data[0] = (png_byte)z_cmf;
- tmp = data[1] & 0xe0;
- tmp += 0x1f - ((z_cmf << 8) + tmp) % 0x1f;
- data[1] = (png_byte)tmp;
- }
- }
- }
-}
-#else
-# define optimize_cmf(dp,dl) ((void)0)
-#endif /* PNG_WRITE_OPTIMIZE_CMF_SUPPORTED */
-
-/* Initialize the compressor for the appropriate type of compression. */
-static int
-png_deflate_claim(png_structrp png_ptr, png_uint_32 owner,
- png_alloc_size_t data_size)
-{
- if (png_ptr->zowner != 0)
- {
- char msg[64];
-
- PNG_STRING_FROM_CHUNK(msg, owner);
- msg[4] = ':';
- msg[5] = ' ';
- PNG_STRING_FROM_CHUNK(msg+6, png_ptr->zowner);
- /* So the message that results is "<chunk> using zstream"; this is an
- * internal error, but is very useful for debugging. i18n requirements
- * are minimal.
- */
- (void)png_safecat(msg, (sizeof msg), 10, " using zstream");
-# if PNG_LIBPNG_BUILD_BASE_TYPE >= PNG_LIBPNG_BUILD_RC
- png_warning(png_ptr, msg);
-
- /* Attempt sane error recovery */
- if (png_ptr->zowner == png_IDAT) /* don't steal from IDAT */
- {
- png_ptr->zstream.msg = PNGZ_MSG_CAST("in use by IDAT");
- return Z_STREAM_ERROR;
- }
-
- png_ptr->zowner = 0;
-# else
- png_error(png_ptr, msg);
-# endif
- }
-
- {
- int level = png_ptr->zlib_level;
- int method = png_ptr->zlib_method;
- int windowBits = png_ptr->zlib_window_bits;
- int memLevel = png_ptr->zlib_mem_level;
- int strategy; /* set below */
- int ret; /* zlib return code */
-
- if (owner == png_IDAT)
- {
- if (png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_STRATEGY)
- strategy = png_ptr->zlib_strategy;
-
- else if (png_ptr->do_filter != PNG_FILTER_NONE)
- strategy = PNG_Z_DEFAULT_STRATEGY;
-
- else
- strategy = PNG_Z_DEFAULT_NOFILTER_STRATEGY;
- }
-
- else
- {
-# ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
- level = png_ptr->zlib_text_level;
- method = png_ptr->zlib_text_method;
- windowBits = png_ptr->zlib_text_window_bits;
- memLevel = png_ptr->zlib_text_mem_level;
- strategy = png_ptr->zlib_text_strategy;
-# else
- /* If customization is not supported the values all come from the
- * IDAT values except for the strategy, which is fixed to the
- * default. (This is the pre-1.6.0 behavior too, although it was
- * implemented in a very different way.)
- */
- strategy = Z_DEFAULT_STRATEGY;
-# endif
- }
-
- /* Adjust 'windowBits' down if larger than 'data_size'; to stop this
- * happening just pass 32768 as the data_size parameter. Notice that zlib
- * requires an extra 262 bytes in the window in addition to the data to be
- * able to see the whole of the data, so if data_size+262 takes us to the
- * next windowBits size we need to fix up the value later. (Because even
- * though deflate needs the extra window, inflate does not!)
- */
- if (data_size <= 16384)
- {
- /* IMPLEMENTATION NOTE: this 'half_window_size' stuff is only here to
- * work round a Microsoft Visual C misbehavior which, contrary to C-90,
- * widens the result of the following shift to 64-bits if (and,
- * apparently, only if) it is used in a test.
- */
- unsigned int half_window_size = 1U << (windowBits-1);
-
- while (data_size + 262 <= half_window_size)
- {
- half_window_size >>= 1;
- --windowBits;
- }
- }
-
- /* Check against the previous initialized values, if any. */
- if ((png_ptr->flags & PNG_FLAG_ZSTREAM_INITIALIZED) &&
- (png_ptr->zlib_set_level != level ||
- png_ptr->zlib_set_method != method ||
- png_ptr->zlib_set_window_bits != windowBits ||
- png_ptr->zlib_set_mem_level != memLevel ||
- png_ptr->zlib_set_strategy != strategy))
- {
- if (deflateEnd(&png_ptr->zstream) != Z_OK)
- png_warning(png_ptr, "deflateEnd failed (ignored)");
-
- png_ptr->flags &= ~PNG_FLAG_ZSTREAM_INITIALIZED;
- }
-
- /* For safety clear out the input and output pointers (currently zlib
- * doesn't use them on Init, but it might in the future).
- */
- png_ptr->zstream.next_in = NULL;
- png_ptr->zstream.avail_in = 0;
- png_ptr->zstream.next_out = NULL;
- png_ptr->zstream.avail_out = 0;
-
- /* Now initialize if required, setting the new parameters, otherwise just
- * to a simple reset to the previous parameters.
- */
- if (png_ptr->flags & PNG_FLAG_ZSTREAM_INITIALIZED)
- ret = deflateReset(&png_ptr->zstream);
-
- else
- {
- ret = deflateInit2(&png_ptr->zstream, level, method, windowBits,
- memLevel, strategy);
-
- if (ret == Z_OK)
- png_ptr->flags |= PNG_FLAG_ZSTREAM_INITIALIZED;
- }
-
- /* The return code is from either deflateReset or deflateInit2; they have
- * pretty much the same set of error codes.
- */
- if (ret == Z_OK)
- png_ptr->zowner = owner;
-
- else
- png_zstream_error(png_ptr, ret);
-
- return ret;
- }
-}
-
-/* Clean up (or trim) a linked list of compression buffers. */
-void /* PRIVATE */
-png_free_buffer_list(png_structrp png_ptr, png_compression_bufferp *listp)
-{
- png_compression_bufferp list = *listp;
-
- if (list != NULL)
- {
- *listp = NULL;
-
- do
- {
- png_compression_bufferp next = list->next;
-
- png_free(png_ptr, list);
- list = next;
- }
- while (list != NULL);
- }
-}
-
-#ifdef PNG_WRITE_COMPRESSED_TEXT_SUPPORTED
-/* This pair of functions encapsulates the operation of (a) compressing a
- * text string, and (b) issuing it later as a series of chunk data writes.
- * The compression_state structure is shared context for these functions
- * set up by the caller to allow access to the relevant local variables.
- *
- * compression_buffer (new in 1.6.0) is just a linked list of zbuffer_size
- * temporary buffers. From 1.6.0 it is retained in png_struct so that it will
- * be correctly freed in the event of a write error (previous implementations
- * just leaked memory.)
- */
-typedef struct
-{
- png_const_bytep input; /* The uncompressed input data */
- png_alloc_size_t input_len; /* Its length */
- png_uint_32 output_len; /* Final compressed length */
- png_byte output[1024]; /* First block of output */
-} compression_state;
-
-static void
-png_text_compress_init(compression_state *comp, png_const_bytep input,
- png_alloc_size_t input_len)
-{
- comp->input = input;
- comp->input_len = input_len;
- comp->output_len = 0;
-}
-
-/* Compress the data in the compression state input */
-static int
-png_text_compress(png_structrp png_ptr, png_uint_32 chunk_name,
- compression_state *comp, png_uint_32 prefix_len)
-{
- int ret;
-
- /* To find the length of the output it is necessary to first compress the
- * input, the result is buffered rather than using the two-pass algorithm
- * that is used on the inflate side; deflate is assumed to be slower and a
- * PNG writer is assumed to have more memory available than a PNG reader.
- *
- * IMPLEMENTATION NOTE: the zlib API deflateBound() can be used to find an
- * upper limit on the output size, but it is always bigger than the input
- * size so it is likely to be more efficient to use this linked-list
- * approach.
- */
- ret = png_deflate_claim(png_ptr, chunk_name, comp->input_len);
-
- if (ret != Z_OK)
- return ret;
-
- /* Set up the compression buffers, we need a loop here to avoid overflowing a
- * uInt. Use ZLIB_IO_MAX to limit the input. The output is always limited
- * by the output buffer size, so there is no need to check that. Since this
- * is ANSI-C we know that an 'int', hence a uInt, is always at least 16 bits
- * in size.
- */
- {
- png_compression_bufferp *end = &png_ptr->zbuffer_list;
- png_alloc_size_t input_len = comp->input_len; /* may be zero! */
- png_uint_32 output_len;
-
- /* zlib updates these for us: */
- png_ptr->zstream.next_in = PNGZ_INPUT_CAST(comp->input);
- png_ptr->zstream.avail_in = 0; /* Set below */
- png_ptr->zstream.next_out = comp->output;
- png_ptr->zstream.avail_out = (sizeof comp->output);
-
- output_len = png_ptr->zstream.avail_out;
-
- do
- {
- uInt avail_in = ZLIB_IO_MAX;
-
- if (avail_in > input_len)
- avail_in = (uInt)input_len;
-
- input_len -= avail_in;
-
- png_ptr->zstream.avail_in = avail_in;
-
- if (png_ptr->zstream.avail_out == 0)
- {
- png_compression_buffer *next;
-
- /* Chunk data is limited to 2^31 bytes in length, so the prefix
- * length must be counted here.
- */
- if (output_len + prefix_len > PNG_UINT_31_MAX)
- {
- ret = Z_MEM_ERROR;
- break;
- }
-
- /* Need a new (malloc'ed) buffer, but there may be one present
- * already.
- */
- next = *end;
- if (next == NULL)
- {
- next = png_voidcast(png_compression_bufferp, png_malloc_base
- (png_ptr, PNG_COMPRESSION_BUFFER_SIZE(png_ptr)));
-
- if (next == NULL)
- {
- ret = Z_MEM_ERROR;
- break;
- }
-
- /* Link in this buffer (so that it will be freed later) */
- next->next = NULL;
- *end = next;
- }
-
- png_ptr->zstream.next_out = next->output;
- png_ptr->zstream.avail_out = png_ptr->zbuffer_size;
- output_len += png_ptr->zstream.avail_out;
-
- /* Move 'end' to the next buffer pointer. */
- end = &next->next;
- }
-
- /* Compress the data */
- ret = deflate(&png_ptr->zstream,
- input_len > 0 ? Z_NO_FLUSH : Z_FINISH);
-
- /* Claw back input data that was not consumed (because avail_in is
- * reset above every time round the loop).
- */
- input_len += png_ptr->zstream.avail_in;
- png_ptr->zstream.avail_in = 0; /* safety */
- }
- while (ret == Z_OK);
-
- /* There may be some space left in the last output buffer, this needs to
- * be subtracted from output_len.
- */
- output_len -= png_ptr->zstream.avail_out;
- png_ptr->zstream.avail_out = 0; /* safety */
- comp->output_len = output_len;
-
- /* Now double check the output length, put in a custom message if it is
- * too long. Otherwise ensure the z_stream::msg pointer is set to
- * something.
- */
- if (output_len + prefix_len >= PNG_UINT_31_MAX)
- {
- png_ptr->zstream.msg = PNGZ_MSG_CAST("compressed data too long");
- ret = Z_MEM_ERROR;
- }
-
- else
- png_zstream_error(png_ptr, ret);
-
- /* Reset zlib for another zTXt/iTXt or image data */
- png_ptr->zowner = 0;
-
- /* The only success case is Z_STREAM_END, input_len must be 0, if not this
- * is an internal error.
- */
- if (ret == Z_STREAM_END && input_len == 0)
- {
- /* Fix up the deflate header, if required */
- optimize_cmf(comp->output, comp->input_len);
-
- /* But Z_OK is returned, not Z_STREAM_END; this allows the claim
- * function above to return Z_STREAM_END on an error (though it never
- * does in the current versions of zlib.)
- */
- return Z_OK;
- }
-
- else
- return ret;
- }
-}
-
-/* Ship the compressed text out via chunk writes */
-static void
-png_write_compressed_data_out(png_structrp png_ptr, compression_state *comp)
-{
- png_uint_32 output_len = comp->output_len;
- png_const_bytep output = comp->output;
- png_uint_32 avail = (sizeof comp->output);
- png_compression_buffer *next = png_ptr->zbuffer_list;
-
- for (;;)
- {
- if (avail > output_len)
- avail = output_len;
-
- png_write_chunk_data(png_ptr, output, avail);
-
- output_len -= avail;
-
- if (output_len == 0 || next == NULL)
- break;
-
- avail = png_ptr->zbuffer_size;
- output = next->output;
- next = next->next;
- }
-
- /* This is an internal error; 'next' must have been NULL! */
- if (output_len > 0)
- png_error(png_ptr, "error writing ancillary chunked compressed data");
-}
-#endif /* PNG_WRITE_COMPRESSED_TEXT_SUPPORTED */
-
-#if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_pCAL_SUPPORTED) || \
- defined(PNG_WRITE_iCCP_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED)
-/* Check that the tEXt or zTXt keyword is valid per PNG 1.0 specification,
- * and if invalid, correct the keyword rather than discarding the entire
- * chunk. The PNG 1.0 specification requires keywords 1-79 characters in
- * length, forbids leading or trailing whitespace, multiple internal spaces,
- * and the non-break space (0x80) from ISO 8859-1. Returns keyword length.
- *
- * The 'new_key' buffer must be 80 characters in size (for the keyword plus a
- * trailing '\0'). If this routine returns 0 then there was no keyword, or a
- * valid one could not be generated, and the caller must png_error.
- */
-static png_uint_32
-png_check_keyword(png_structrp png_ptr, png_const_charp key, png_bytep new_key)
-{
- png_const_charp orig_key = key;
- png_uint_32 key_len = 0;
- int bad_character = 0;
- int space = 1;
-
- png_debug(1, "in png_check_keyword");
-
- if (key == NULL)
- {
- *new_key = 0;
- return 0;
- }
-
- while (*key && key_len < 79)
- {
- png_byte ch = (png_byte)(0xff & *key++);
-
- if ((ch > 32 && ch <= 126) || (ch >= 161 /*&& ch <= 255*/))
- *new_key++ = ch, ++key_len, space = 0;
-
- else if (!space)
- {
- /* A space or an invalid character when one wasn't seen immediately
- * before; output just a space.
- */
- *new_key++ = 32, ++key_len, space = 1;
-
- /* If the character was not a space then it is invalid. */
- if (ch != 32)
- bad_character = ch;
- }
-
- else if (!bad_character)
- bad_character = ch; /* just skip it, record the first error */
- }
-
- if (key_len > 0 && space) /* trailing space */
- {
- --key_len, --new_key;
- if (!bad_character)
- bad_character = 32;
- }
-
- /* Terminate the keyword */
- *new_key = 0;
-
- if (key_len == 0)
- return 0;
-
- /* Try to only output one warning per keyword: */
- if (*key) /* keyword too long */
- png_warning(png_ptr, "keyword truncated");
-
- else if (bad_character)
- {
- PNG_WARNING_PARAMETERS(p)
-
- png_warning_parameter(p, 1, orig_key);
- png_warning_parameter_signed(p, 2, PNG_NUMBER_FORMAT_02x, bad_character);
-
- png_formatted_warning(png_ptr, p, "keyword \"@1\": bad character '0x@2'");
- }
-
- return key_len;
-}
-#endif
-
-/* Write the IHDR chunk, and update the png_struct with the necessary
- * information. Note that the rest of this code depends upon this
- * information being correct.
- */
-void /* PRIVATE */
-png_write_IHDR(png_structrp png_ptr, png_uint_32 width, png_uint_32 height,
- int bit_depth, int color_type, int compression_type, int filter_type,
- int interlace_type)
-{
- png_byte buf[13]; /* Buffer to store the IHDR info */
-
- png_debug(1, "in png_write_IHDR");
-
- /* Check that we have valid input data from the application info */
- switch (color_type)
- {
- case PNG_COLOR_TYPE_GRAY:
- switch (bit_depth)
- {
- case 1:
- case 2:
- case 4:
- case 8:
-#ifdef PNG_WRITE_16BIT_SUPPORTED
- case 16:
-#endif
- png_ptr->channels = 1; break;
-
- default:
- png_error(png_ptr,
- "Invalid bit depth for grayscale image");
- }
- break;
-
- case PNG_COLOR_TYPE_RGB:
-#ifdef PNG_WRITE_16BIT_SUPPORTED
- if (bit_depth != 8 && bit_depth != 16)
-#else
- if (bit_depth != 8)
-#endif
- png_error(png_ptr, "Invalid bit depth for RGB image");
-
- png_ptr->channels = 3;
- break;
-
- case PNG_COLOR_TYPE_PALETTE:
- switch (bit_depth)
- {
- case 1:
- case 2:
- case 4:
- case 8:
- png_ptr->channels = 1;
- break;
-
- default:
- png_error(png_ptr, "Invalid bit depth for paletted image");
- }
- break;
-
- case PNG_COLOR_TYPE_GRAY_ALPHA:
- if (bit_depth != 8 && bit_depth != 16)
- png_error(png_ptr, "Invalid bit depth for grayscale+alpha image");
-
- png_ptr->channels = 2;
- break;
-
- case PNG_COLOR_TYPE_RGB_ALPHA:
-#ifdef PNG_WRITE_16BIT_SUPPORTED
- if (bit_depth != 8 && bit_depth != 16)
-#else
- if (bit_depth != 8)
-#endif
- png_error(png_ptr, "Invalid bit depth for RGBA image");
-
- png_ptr->channels = 4;
- break;
-
- default:
- png_error(png_ptr, "Invalid image color type specified");
- }
-
- if (compression_type != PNG_COMPRESSION_TYPE_BASE)
- {
- png_warning(png_ptr, "Invalid compression type specified");
- compression_type = PNG_COMPRESSION_TYPE_BASE;
- }
-
- /* Write filter_method 64 (intrapixel differencing) only if
- * 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and
- * 2. Libpng did not write a PNG signature (this filter_method is only
- * used in PNG datastreams that are embedded in MNG datastreams) and
- * 3. The application called png_permit_mng_features with a mask that
- * included PNG_FLAG_MNG_FILTER_64 and
- * 4. The filter_method is 64 and
- * 5. The color_type is RGB or RGBA
- */
- if (
-#ifdef PNG_MNG_FEATURES_SUPPORTED
- !((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
- ((png_ptr->mode&PNG_HAVE_PNG_SIGNATURE) == 0) &&
- (color_type == PNG_COLOR_TYPE_RGB ||
- color_type == PNG_COLOR_TYPE_RGB_ALPHA) &&
- (filter_type == PNG_INTRAPIXEL_DIFFERENCING)) &&
-#endif
- filter_type != PNG_FILTER_TYPE_BASE)
- {
- png_warning(png_ptr, "Invalid filter type specified");
- filter_type = PNG_FILTER_TYPE_BASE;
- }
-
-#ifdef PNG_WRITE_INTERLACING_SUPPORTED
- if (interlace_type != PNG_INTERLACE_NONE &&
- interlace_type != PNG_INTERLACE_ADAM7)
- {
- png_warning(png_ptr, "Invalid interlace type specified");
- interlace_type = PNG_INTERLACE_ADAM7;
- }
-#else
- interlace_type=PNG_INTERLACE_NONE;
-#endif
-
- /* Save the relevent information */
- png_ptr->bit_depth = (png_byte)bit_depth;
- png_ptr->color_type = (png_byte)color_type;
- png_ptr->interlaced = (png_byte)interlace_type;
-#ifdef PNG_MNG_FEATURES_SUPPORTED
- png_ptr->filter_type = (png_byte)filter_type;
-#endif
- png_ptr->compression_type = (png_byte)compression_type;
- png_ptr->width = width;
- png_ptr->height = height;
-
- png_ptr->pixel_depth = (png_byte)(bit_depth * png_ptr->channels);
- png_ptr->rowbytes = PNG_ROWBYTES(png_ptr->pixel_depth, width);
- /* Set the usr info, so any transformations can modify it */
- png_ptr->usr_width = png_ptr->width;
- png_ptr->usr_bit_depth = png_ptr->bit_depth;
- png_ptr->usr_channels = png_ptr->channels;
-
- /* Pack the header information into the buffer */
- png_save_uint_32(buf, width);
- png_save_uint_32(buf + 4, height);
- buf[8] = (png_byte)bit_depth;
- buf[9] = (png_byte)color_type;
- buf[10] = (png_byte)compression_type;
- buf[11] = (png_byte)filter_type;
- buf[12] = (png_byte)interlace_type;
-
- /* Write the chunk */
- png_write_complete_chunk(png_ptr, png_IHDR, buf, (png_size_t)13);
-
- if (!(png_ptr->do_filter))
- {
- if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE ||
- png_ptr->bit_depth < 8)
- png_ptr->do_filter = PNG_FILTER_NONE;
-
- else
- png_ptr->do_filter = PNG_ALL_FILTERS;
- }
-
- png_ptr->mode = PNG_HAVE_IHDR; /* not READY_FOR_ZTXT */
-}
-
-/* Write the palette. We are careful not to trust png_color to be in the
- * correct order for PNG, so people can redefine it to any convenient
- * structure.
- */
-void /* PRIVATE */
-png_write_PLTE(png_structrp png_ptr, png_const_colorp palette,
- png_uint_32 num_pal)
-{
- png_uint_32 i;
- png_const_colorp pal_ptr;
- png_byte buf[3];
-
- png_debug(1, "in png_write_PLTE");
-
- if ((
-#ifdef PNG_MNG_FEATURES_SUPPORTED
- !(png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE) &&
-#endif
- num_pal == 0) || num_pal > 256)
- {
- if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
- {
- png_error(png_ptr, "Invalid number of colors in palette");
- }
-
- else
- {
- png_warning(png_ptr, "Invalid number of colors in palette");
- return;
- }
- }
-
- if (!(png_ptr->color_type&PNG_COLOR_MASK_COLOR))
- {
- png_warning(png_ptr,
- "Ignoring request to write a PLTE chunk in grayscale PNG");
-
- return;
- }
-
- png_ptr->num_palette = (png_uint_16)num_pal;
- png_debug1(3, "num_palette = %d", png_ptr->num_palette);
-
- png_write_chunk_header(png_ptr, png_PLTE, (png_uint_32)(num_pal * 3));
-#ifdef PNG_POINTER_INDEXING_SUPPORTED
-
- for (i = 0, pal_ptr = palette; i < num_pal; i++, pal_ptr++)
- {
- buf[0] = pal_ptr->red;
- buf[1] = pal_ptr->green;
- buf[2] = pal_ptr->blue;
- png_write_chunk_data(png_ptr, buf, (png_size_t)3);
- }
-
-#else
- /* This is a little slower but some buggy compilers need to do this
- * instead
- */
- pal_ptr=palette;
-
- for (i = 0; i < num_pal; i++)
- {
- buf[0] = pal_ptr[i].red;
- buf[1] = pal_ptr[i].green;
- buf[2] = pal_ptr[i].blue;
- png_write_chunk_data(png_ptr, buf, (png_size_t)3);
- }
-
-#endif
- png_write_chunk_end(png_ptr);
- png_ptr->mode |= PNG_HAVE_PLTE;
-}
-
-/* This is similar to png_text_compress, above, except that it does not require
- * all of the data at once and, instead of buffering the compressed result,
- * writes it as IDAT chunks. Unlike png_text_compress it *can* png_error out
- * because it calls the write interface. As a result it does its own error
- * reporting and does not return an error code. In the event of error it will
- * just call png_error. The input data length may exceed 32-bits. The 'flush'
- * parameter is exactly the same as that to deflate, with the following
- * meanings:
- *
- * Z_NO_FLUSH: normal incremental output of compressed data
- * Z_SYNC_FLUSH: do a SYNC_FLUSH, used by png_write_flush
- * Z_FINISH: this is the end of the input, do a Z_FINISH and clean up
- *
- * The routine manages the acquire and release of the png_ptr->zstream by
- * checking and (at the end) clearing png_ptr->zowner, it does some sanity
- * checks on the 'mode' flags while doing this.
- */
-void /* PRIVATE */
-png_compress_IDAT(png_structrp png_ptr, png_const_bytep input,
- png_alloc_size_t input_len, int flush)
-{
- if (png_ptr->zowner != png_IDAT)
- {
- /* First time. Ensure we have a temporary buffer for compression and
- * trim the buffer list if it has more than one entry to free memory.
- * If 'WRITE_COMPRESSED_TEXT' is not set the list will never have been
- * created at this point, but the check here is quick and safe.
- */
- if (png_ptr->zbuffer_list == NULL)
- {
- png_ptr->zbuffer_list = png_voidcast(png_compression_bufferp,
- png_malloc(png_ptr, PNG_COMPRESSION_BUFFER_SIZE(png_ptr)));
- png_ptr->zbuffer_list->next = NULL;
- }
-
- else
- png_free_buffer_list(png_ptr, &png_ptr->zbuffer_list->next);
-
- /* It is a terminal error if we can't claim the zstream. */
- if (png_deflate_claim(png_ptr, png_IDAT, png_image_size(png_ptr)) != Z_OK)
- png_error(png_ptr, png_ptr->zstream.msg);
-
- /* The output state is maintained in png_ptr->zstream, so it must be
- * initialized here after the claim.
- */
- png_ptr->zstream.next_out = png_ptr->zbuffer_list->output;
- png_ptr->zstream.avail_out = png_ptr->zbuffer_size;
- }
-
- /* Now loop reading and writing until all the input is consumed or an error
- * terminates the operation. The _out values are maintained across calls to
- * this function, but the input must be reset each time.
- */
- png_ptr->zstream.next_in = PNGZ_INPUT_CAST(input);
- png_ptr->zstream.avail_in = 0; /* set below */
- for (;;)
- {
- int ret;
-
- /* INPUT: from the row data */
- uInt avail = ZLIB_IO_MAX;
-
- if (avail > input_len)
- avail = (uInt)input_len; /* safe because of the check */
-
- png_ptr->zstream.avail_in = avail;
- input_len -= avail;
-
- ret = deflate(&png_ptr->zstream, input_len > 0 ? Z_NO_FLUSH : flush);
-
- /* Include as-yet unconsumed input */
- input_len += png_ptr->zstream.avail_in;
- png_ptr->zstream.avail_in = 0;
-
- /* OUTPUT: write complete IDAT chunks when avail_out drops to zero, note
- * that these two zstream fields are preserved across the calls, therefore
- * there is no need to set these up on entry to the loop.
- */
- if (png_ptr->zstream.avail_out == 0)
- {
- png_bytep data = png_ptr->zbuffer_list->output;
- uInt size = png_ptr->zbuffer_size;
-
- /* Write an IDAT containing the data then reset the buffer. The
- * first IDAT may need deflate header optimization.
- */
-# ifdef PNG_WRITE_OPTIMIZE_CMF_SUPPORTED
- if (!(png_ptr->mode & PNG_HAVE_IDAT) &&
- png_ptr->compression_type == PNG_COMPRESSION_TYPE_BASE)
- optimize_cmf(data, png_image_size(png_ptr));
-# endif
-
- png_write_complete_chunk(png_ptr, png_IDAT, data, size);
- png_ptr->mode |= PNG_HAVE_IDAT;
-
- png_ptr->zstream.next_out = data;
- png_ptr->zstream.avail_out = size;
-
- /* For SYNC_FLUSH or FINISH it is essential to keep calling zlib with
- * the same flush parameter until it has finished output, for NO_FLUSH
- * it doesn't matter.
- */
- if (ret == Z_OK && flush != Z_NO_FLUSH)
- continue;
- }
-
- /* The order of these checks doesn't matter much; it just effect which
- * possible error might be detected if multiple things go wrong at once.
- */
- if (ret == Z_OK) /* most likely return code! */
- {
- /* If all the input has been consumed then just return. If Z_FINISH
- * was used as the flush parameter something has gone wrong if we get
- * here.
- */
- if (input_len == 0)
- {
- if (flush == Z_FINISH)
- png_error(png_ptr, "Z_OK on Z_FINISH with output space");
-
- return;
- }
- }
-
- else if (ret == Z_STREAM_END && flush == Z_FINISH)
- {
- /* This is the end of the IDAT data; any pending output must be
- * flushed. For small PNG files we may still be at the beginning.
- */
- png_bytep data = png_ptr->zbuffer_list->output;
- uInt size = png_ptr->zbuffer_size - png_ptr->zstream.avail_out;
-
-# ifdef PNG_WRITE_OPTIMIZE_CMF_SUPPORTED
- if (!(png_ptr->mode & PNG_HAVE_IDAT) &&
- png_ptr->compression_type == PNG_COMPRESSION_TYPE_BASE)
- optimize_cmf(data, png_image_size(png_ptr));
-# endif
-
- png_write_complete_chunk(png_ptr, png_IDAT, data, size);
- png_ptr->zstream.avail_out = 0;
- png_ptr->zstream.next_out = NULL;
- png_ptr->mode |= PNG_HAVE_IDAT | PNG_AFTER_IDAT;
-
- png_ptr->zowner = 0; /* Release the stream */
- return;
- }
-
- else
- {
- /* This is an error condition. */
- png_zstream_error(png_ptr, ret);
- png_error(png_ptr, png_ptr->zstream.msg);
- }
- }
-}
-
-/* Write an IEND chunk */
-void /* PRIVATE */
-png_write_IEND(png_structrp png_ptr)
-{
- png_debug(1, "in png_write_IEND");
-
- png_write_complete_chunk(png_ptr, png_IEND, NULL, (png_size_t)0);
- png_ptr->mode |= PNG_HAVE_IEND;
-}
-
-#ifdef PNG_WRITE_gAMA_SUPPORTED
-/* Write a gAMA chunk */
-void /* PRIVATE */
-png_write_gAMA_fixed(png_structrp png_ptr, png_fixed_point file_gamma)
-{
- png_byte buf[4];
-
- png_debug(1, "in png_write_gAMA");
-
- /* file_gamma is saved in 1/100,000ths */
- png_save_uint_32(buf, (png_uint_32)file_gamma);
- png_write_complete_chunk(png_ptr, png_gAMA, buf, (png_size_t)4);
-}
-#endif
-
-#ifdef PNG_WRITE_sRGB_SUPPORTED
-/* Write a sRGB chunk */
-void /* PRIVATE */
-png_write_sRGB(png_structrp png_ptr, int srgb_intent)
-{
- png_byte buf[1];
-
- png_debug(1, "in png_write_sRGB");
-
- if (srgb_intent >= PNG_sRGB_INTENT_LAST)
- png_warning(png_ptr,
- "Invalid sRGB rendering intent specified");
-
- buf[0]=(png_byte)srgb_intent;
- png_write_complete_chunk(png_ptr, png_sRGB, buf, (png_size_t)1);
-}
-#endif
-
-#ifdef PNG_WRITE_iCCP_SUPPORTED
-/* Write an iCCP chunk */
-void /* PRIVATE */
-png_write_iCCP(png_structrp png_ptr, png_const_charp name,
- png_const_bytep profile)
-{
- png_uint_32 name_len;
- png_uint_32 profile_len;
- png_byte new_name[81]; /* 1 byte for the compression byte */
- compression_state comp;
-
- png_debug(1, "in png_write_iCCP");
-
- /* These are all internal problems: the profile should have been checked
- * before when it was stored.
- */
- if (profile == NULL)
- png_error(png_ptr, "No profile for iCCP chunk"); /* internal error */
-
- profile_len = png_get_uint_32(profile);
-
- if (profile_len < 132)
- png_error(png_ptr, "ICC profile too short");
-
- if (profile_len & 0x03)
- png_error(png_ptr, "ICC profile length invalid (not a multiple of 4)");
-
- {
- png_uint_32 embedded_profile_len = png_get_uint_32(profile);
-
- if (profile_len != embedded_profile_len)
- png_error(png_ptr, "Profile length does not match profile");
- }
-
- name_len = png_check_keyword(png_ptr, name, new_name);
-
- if (name_len == 0)
- png_error(png_ptr, "iCCP: invalid keyword");
-
- new_name[++name_len] = PNG_COMPRESSION_TYPE_BASE;
-
- /* Make sure we include the NULL after the name and the compression type */
- ++name_len;
-
- png_text_compress_init(&comp, profile, profile_len);
-
- /* Allow for keyword terminator and compression byte */
- if (png_text_compress(png_ptr, png_iCCP, &comp, name_len) != Z_OK)
- png_error(png_ptr, png_ptr->zstream.msg);
-
- png_write_chunk_header(png_ptr, png_iCCP, name_len + comp.output_len);
-
- png_write_chunk_data(png_ptr, new_name, name_len);
-
- png_write_compressed_data_out(png_ptr, &comp);
-
- png_write_chunk_end(png_ptr);
-}
-#endif
-
-#ifdef PNG_WRITE_sPLT_SUPPORTED
-/* Write a sPLT chunk */
-void /* PRIVATE */
-png_write_sPLT(png_structrp png_ptr, png_const_sPLT_tp spalette)
-{
- png_uint_32 name_len;
- png_byte new_name[80];
- png_byte entrybuf[10];
- png_size_t entry_size = (spalette->depth == 8 ? 6 : 10);
- png_size_t palette_size = entry_size * spalette->nentries;
- png_sPLT_entryp ep;
-#ifndef PNG_POINTER_INDEXING_SUPPORTED
- int i;
-#endif
-
- png_debug(1, "in png_write_sPLT");
-
- name_len = png_check_keyword(png_ptr, spalette->name, new_name);
-
- if (name_len == 0)
- png_error(png_ptr, "sPLT: invalid keyword");
-
- /* Make sure we include the NULL after the name */
- png_write_chunk_header(png_ptr, png_sPLT,
- (png_uint_32)(name_len + 2 + palette_size));
-
- png_write_chunk_data(png_ptr, (png_bytep)new_name,
- (png_size_t)(name_len + 1));
-
- png_write_chunk_data(png_ptr, &spalette->depth, (png_size_t)1);
-
- /* Loop through each palette entry, writing appropriately */
-#ifdef PNG_POINTER_INDEXING_SUPPORTED
- for (ep = spalette->entries; ep<spalette->entries + spalette->nentries; ep++)
- {
- if (spalette->depth == 8)
- {
- entrybuf[0] = (png_byte)ep->red;
- entrybuf[1] = (png_byte)ep->green;
- entrybuf[2] = (png_byte)ep->blue;
- entrybuf[3] = (png_byte)ep->alpha;
- png_save_uint_16(entrybuf + 4, ep->frequency);
- }
-
- else
- {
- png_save_uint_16(entrybuf + 0, ep->red);
- png_save_uint_16(entrybuf + 2, ep->green);
- png_save_uint_16(entrybuf + 4, ep->blue);
- png_save_uint_16(entrybuf + 6, ep->alpha);
- png_save_uint_16(entrybuf + 8, ep->frequency);
- }
-
- png_write_chunk_data(png_ptr, entrybuf, entry_size);
- }
-#else
- ep=spalette->entries;
- for (i = 0; i>spalette->nentries; i++)
- {
- if (spalette->depth == 8)
- {
- entrybuf[0] = (png_byte)ep[i].red;
- entrybuf[1] = (png_byte)ep[i].green;
- entrybuf[2] = (png_byte)ep[i].blue;
- entrybuf[3] = (png_byte)ep[i].alpha;
- png_save_uint_16(entrybuf + 4, ep[i].frequency);
- }
-
- else
- {
- png_save_uint_16(entrybuf + 0, ep[i].red);
- png_save_uint_16(entrybuf + 2, ep[i].green);
- png_save_uint_16(entrybuf + 4, ep[i].blue);
- png_save_uint_16(entrybuf + 6, ep[i].alpha);
- png_save_uint_16(entrybuf + 8, ep[i].frequency);
- }
-
- png_write_chunk_data(png_ptr, entrybuf, entry_size);
- }
-#endif
-
- png_write_chunk_end(png_ptr);
-}
-#endif
-
-#ifdef PNG_WRITE_sBIT_SUPPORTED
-/* Write the sBIT chunk */
-void /* PRIVATE */
-png_write_sBIT(png_structrp png_ptr, png_const_color_8p sbit, int color_type)
-{
- png_byte buf[4];
- png_size_t size;
-
- png_debug(1, "in png_write_sBIT");
-
- /* Make sure we don't depend upon the order of PNG_COLOR_8 */
- if (color_type & PNG_COLOR_MASK_COLOR)
- {
- png_byte maxbits;
-
- maxbits = (png_byte)(color_type==PNG_COLOR_TYPE_PALETTE ? 8 :
- png_ptr->usr_bit_depth);
-
- if (sbit->red == 0 || sbit->red > maxbits ||
- sbit->green == 0 || sbit->green > maxbits ||
- sbit->blue == 0 || sbit->blue > maxbits)
- {
- png_warning(png_ptr, "Invalid sBIT depth specified");
- return;
- }
-
- buf[0] = sbit->red;
- buf[1] = sbit->green;
- buf[2] = sbit->blue;
- size = 3;
- }
-
- else
- {
- if (sbit->gray == 0 || sbit->gray > png_ptr->usr_bit_depth)
- {
- png_warning(png_ptr, "Invalid sBIT depth specified");
- return;
- }
-
- buf[0] = sbit->gray;
- size = 1;
- }
-
- if (color_type & PNG_COLOR_MASK_ALPHA)
- {
- if (sbit->alpha == 0 || sbit->alpha > png_ptr->usr_bit_depth)
- {
- png_warning(png_ptr, "Invalid sBIT depth specified");
- return;
- }
-
- buf[size++] = sbit->alpha;
- }
-
- png_write_complete_chunk(png_ptr, png_sBIT, buf, size);
-}
-#endif
-
-#ifdef PNG_WRITE_cHRM_SUPPORTED
-/* Write the cHRM chunk */
-void /* PRIVATE */
-png_write_cHRM_fixed(png_structrp png_ptr, const png_xy *xy)
-{
- png_byte buf[32];
-
- png_debug(1, "in png_write_cHRM");
-
- /* Each value is saved in 1/100,000ths */
- png_save_int_32(buf, xy->whitex);
- png_save_int_32(buf + 4, xy->whitey);
-
- png_save_int_32(buf + 8, xy->redx);
- png_save_int_32(buf + 12, xy->redy);
-
- png_save_int_32(buf + 16, xy->greenx);
- png_save_int_32(buf + 20, xy->greeny);
-
- png_save_int_32(buf + 24, xy->bluex);
- png_save_int_32(buf + 28, xy->bluey);
-
- png_write_complete_chunk(png_ptr, png_cHRM, buf, 32);
-}
-#endif
-
-#ifdef PNG_WRITE_tRNS_SUPPORTED
-/* Write the tRNS chunk */
-void /* PRIVATE */
-png_write_tRNS(png_structrp png_ptr, png_const_bytep trans_alpha,
- png_const_color_16p tran, int num_trans, int color_type)
-{
- png_byte buf[6];
-
- png_debug(1, "in png_write_tRNS");
-
- if (color_type == PNG_COLOR_TYPE_PALETTE)
- {
- if (num_trans <= 0 || num_trans > (int)png_ptr->num_palette)
- {
- png_app_warning(png_ptr,
- "Invalid number of transparent colors specified");
- return;
- }
-
- /* Write the chunk out as it is */
- png_write_complete_chunk(png_ptr, png_tRNS, trans_alpha,
- (png_size_t)num_trans);
- }
-
- else if (color_type == PNG_COLOR_TYPE_GRAY)
- {
- /* One 16 bit value */
- if (tran->gray >= (1 << png_ptr->bit_depth))
- {
- png_app_warning(png_ptr,
- "Ignoring attempt to write tRNS chunk out-of-range for bit_depth");
-
- return;
- }
-
- png_save_uint_16(buf, tran->gray);
- png_write_complete_chunk(png_ptr, png_tRNS, buf, (png_size_t)2);
- }
-
- else if (color_type == PNG_COLOR_TYPE_RGB)
- {
- /* Three 16 bit values */
- png_save_uint_16(buf, tran->red);
- png_save_uint_16(buf + 2, tran->green);
- png_save_uint_16(buf + 4, tran->blue);
-#ifdef PNG_WRITE_16BIT_SUPPORTED
- if (png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4]))
-#else
- if (buf[0] | buf[2] | buf[4])
-#endif
- {
- png_app_warning(png_ptr,
- "Ignoring attempt to write 16-bit tRNS chunk when bit_depth is 8");
- return;
- }
-
- png_write_complete_chunk(png_ptr, png_tRNS, buf, (png_size_t)6);
- }
-
- else
- {
- png_app_warning(png_ptr, "Can't write tRNS with an alpha channel");
- }
-}
-#endif
-
-#ifdef PNG_WRITE_bKGD_SUPPORTED
-/* Write the background chunk */
-void /* PRIVATE */
-png_write_bKGD(png_structrp png_ptr, png_const_color_16p back, int color_type)
-{
- png_byte buf[6];
-
- png_debug(1, "in png_write_bKGD");
-
- if (color_type == PNG_COLOR_TYPE_PALETTE)
- {
- if (
-#ifdef PNG_MNG_FEATURES_SUPPORTED
- (png_ptr->num_palette ||
- (!(png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE))) &&
-#endif
- back->index >= png_ptr->num_palette)
- {
- png_warning(png_ptr, "Invalid background palette index");
- return;
- }
-
- buf[0] = back->index;
- png_write_complete_chunk(png_ptr, png_bKGD, buf, (png_size_t)1);
- }
-
- else if (color_type & PNG_COLOR_MASK_COLOR)
- {
- png_save_uint_16(buf, back->red);
- png_save_uint_16(buf + 2, back->green);
- png_save_uint_16(buf + 4, back->blue);
-#ifdef PNG_WRITE_16BIT_SUPPORTED
- if (png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4]))
-#else
- if (buf[0] | buf[2] | buf[4])
-#endif
- {
- png_warning(png_ptr,
- "Ignoring attempt to write 16-bit bKGD chunk when bit_depth is 8");
-
- return;
- }
-
- png_write_complete_chunk(png_ptr, png_bKGD, buf, (png_size_t)6);
- }
-
- else
- {
- if (back->gray >= (1 << png_ptr->bit_depth))
- {
- png_warning(png_ptr,
- "Ignoring attempt to write bKGD chunk out-of-range for bit_depth");
-
- return;
- }
-
- png_save_uint_16(buf, back->gray);
- png_write_complete_chunk(png_ptr, png_bKGD, buf, (png_size_t)2);
- }
-}
-#endif
-
-#ifdef PNG_WRITE_hIST_SUPPORTED
-/* Write the histogram */
-void /* PRIVATE */
-png_write_hIST(png_structrp png_ptr, png_const_uint_16p hist, int num_hist)
-{
- int i;
- png_byte buf[3];
-
- png_debug(1, "in png_write_hIST");
-
- if (num_hist > (int)png_ptr->num_palette)
- {
- png_debug2(3, "num_hist = %d, num_palette = %d", num_hist,
- png_ptr->num_palette);
-
- png_warning(png_ptr, "Invalid number of histogram entries specified");
- return;
- }
-
- png_write_chunk_header(png_ptr, png_hIST, (png_uint_32)(num_hist * 2));
-
- for (i = 0; i < num_hist; i++)
- {
- png_save_uint_16(buf, hist[i]);
- png_write_chunk_data(png_ptr, buf, (png_size_t)2);
- }
-
- png_write_chunk_end(png_ptr);
-}
-#endif
-
-#ifdef PNG_WRITE_tEXt_SUPPORTED
-/* Write a tEXt chunk */
-void /* PRIVATE */
-png_write_tEXt(png_structrp png_ptr, png_const_charp key, png_const_charp text,
- png_size_t text_len)
-{
- png_uint_32 key_len;
- png_byte new_key[80];
-
- png_debug(1, "in png_write_tEXt");
-
- key_len = png_check_keyword(png_ptr, key, new_key);
-
- if (key_len == 0)
- png_error(png_ptr, "tEXt: invalid keyword");
-
- if (text == NULL || *text == '\0')
- text_len = 0;
-
- else
- text_len = strlen(text);
-
- if (text_len > PNG_UINT_31_MAX - (key_len+1))
- png_error(png_ptr, "tEXt: text too long");
-
- /* Make sure we include the 0 after the key */
- png_write_chunk_header(png_ptr, png_tEXt,
- (png_uint_32)/*checked above*/(key_len + text_len + 1));
- /*
- * We leave it to the application to meet PNG-1.0 requirements on the
- * contents of the text. PNG-1.0 through PNG-1.2 discourage the use of
- * any non-Latin-1 characters except for NEWLINE. ISO PNG will forbid them.
- * The NUL character is forbidden by PNG-1.0 through PNG-1.2 and ISO PNG.
- */
- png_write_chunk_data(png_ptr, new_key, key_len + 1);
-
- if (text_len)
- png_write_chunk_data(png_ptr, (png_const_bytep)text, text_len);
-
- png_write_chunk_end(png_ptr);
-}
-#endif
-
-#ifdef PNG_WRITE_zTXt_SUPPORTED
-/* Write a compressed text chunk */
-void /* PRIVATE */
-png_write_zTXt(png_structrp png_ptr, png_const_charp key, png_const_charp text,
- png_size_t text_len, int compression)
-{
- png_uint_32 key_len;
- png_byte new_key[81];
- compression_state comp;
-
- png_debug(1, "in png_write_zTXt");
- PNG_UNUSED(text_len) /* Always use strlen */
-
- if (compression == PNG_TEXT_COMPRESSION_NONE)
- {
- png_write_tEXt(png_ptr, key, text, 0);
- return;
- }
-
- if (compression != PNG_TEXT_COMPRESSION_zTXt)
- png_error(png_ptr, "zTXt: invalid compression type");
-
- key_len = png_check_keyword(png_ptr, key, new_key);
-
- if (key_len == 0)
- png_error(png_ptr, "zTXt: invalid keyword");
-
- /* Add the compression method and 1 for the keyword separator. */
- new_key[++key_len] = PNG_COMPRESSION_TYPE_BASE;
- ++key_len;
-
- /* Compute the compressed data; do it now for the length */
- png_text_compress_init(&comp, (png_const_bytep)text,
- text == NULL ? 0 : strlen(text));
-
- if (png_text_compress(png_ptr, png_zTXt, &comp, key_len) != Z_OK)
- png_error(png_ptr, png_ptr->zstream.msg);
-
- /* Write start of chunk */
- png_write_chunk_header(png_ptr, png_zTXt, key_len + comp.output_len);
-
- /* Write key */
- png_write_chunk_data(png_ptr, new_key, key_len);
-
- /* Write the compressed data */
- png_write_compressed_data_out(png_ptr, &comp);
-
- /* Close the chunk */
- png_write_chunk_end(png_ptr);
-}
-#endif
-
-#ifdef PNG_WRITE_iTXt_SUPPORTED
-/* Write an iTXt chunk */
-void /* PRIVATE */
-png_write_iTXt(png_structrp png_ptr, int compression, png_const_charp key,
- png_const_charp lang, png_const_charp lang_key, png_const_charp text)
-{
- png_uint_32 key_len, prefix_len;
- png_size_t lang_len, lang_key_len;
- png_byte new_key[82];
- compression_state comp;
-
- png_debug(1, "in png_write_iTXt");
-
- key_len = png_check_keyword(png_ptr, key, new_key);
-
- if (key_len == 0)
- png_error(png_ptr, "iTXt: invalid keyword");
-
- /* Set the compression flag */
- switch (compression)
- {
- case PNG_ITXT_COMPRESSION_NONE:
- case PNG_TEXT_COMPRESSION_NONE:
- compression = new_key[++key_len] = 0; /* no compression */
- break;
-
- case PNG_TEXT_COMPRESSION_zTXt:
- case PNG_ITXT_COMPRESSION_zTXt:
- compression = new_key[++key_len] = 1; /* compressed */
- break;
-
- default:
- png_error(png_ptr, "iTXt: invalid compression");
- }
-
- new_key[++key_len] = PNG_COMPRESSION_TYPE_BASE;
- ++key_len; /* for the keywod separator */
-
- /* We leave it to the application to meet PNG-1.0 requirements on the
- * contents of the text. PNG-1.0 through PNG-1.2 discourage the use of
- * any non-Latin-1 characters except for NEWLINE. ISO PNG, however,
- * specifies that the text is UTF-8 and this really doesn't require any
- * checking.
- *
- * The NUL character is forbidden by PNG-1.0 through PNG-1.2 and ISO PNG.
- *
- * TODO: validate the language tag correctly (see the spec.)
- */
- if (lang == NULL) lang = ""; /* empty language is valid */
- lang_len = strlen(lang)+1;
- if (lang_key == NULL) lang_key = ""; /* may be empty */
- lang_key_len = strlen(lang_key)+1;
- if (text == NULL) text = ""; /* may be empty */
-
- prefix_len = key_len;
- if (lang_len > PNG_UINT_31_MAX-prefix_len)
- prefix_len = PNG_UINT_31_MAX;
- else
- prefix_len = (png_uint_32)(prefix_len + lang_len);
-
- if (lang_key_len > PNG_UINT_31_MAX-prefix_len)
- prefix_len = PNG_UINT_31_MAX;
- else
- prefix_len = (png_uint_32)(prefix_len + lang_key_len);
-
- png_text_compress_init(&comp, (png_const_bytep)text, strlen(text));
-
- if (compression)
- {
- if (png_text_compress(png_ptr, png_iTXt, &comp, prefix_len) != Z_OK)
- png_error(png_ptr, png_ptr->zstream.msg);
- }
-
- else
- {
- if (comp.input_len > PNG_UINT_31_MAX-prefix_len)
- png_error(png_ptr, "iTXt: uncompressed text too long");
-
- /* So the string will fit in a chunk: */
- comp.output_len = (png_uint_32)/*SAFE*/comp.input_len;
- }
-
- png_write_chunk_header(png_ptr, png_iTXt, comp.output_len + prefix_len);
-
- png_write_chunk_data(png_ptr, new_key, key_len);
-
- png_write_chunk_data(png_ptr, (png_const_bytep)lang, lang_len);
-
- png_write_chunk_data(png_ptr, (png_const_bytep)lang_key, lang_key_len);
-
- if (compression)
- png_write_compressed_data_out(png_ptr, &comp);
-
- else
- png_write_chunk_data(png_ptr, (png_const_bytep)text, comp.input_len);
-
- png_write_chunk_end(png_ptr);
-}
-#endif
-
-#ifdef PNG_WRITE_oFFs_SUPPORTED
-/* Write the oFFs chunk */
-void /* PRIVATE */
-png_write_oFFs(png_structrp png_ptr, png_int_32 x_offset, png_int_32 y_offset,
- int unit_type)
-{
- png_byte buf[9];
-
- png_debug(1, "in png_write_oFFs");
-
- if (unit_type >= PNG_OFFSET_LAST)
- png_warning(png_ptr, "Unrecognized unit type for oFFs chunk");
-
- png_save_int_32(buf, x_offset);
- png_save_int_32(buf + 4, y_offset);
- buf[8] = (png_byte)unit_type;
-
- png_write_complete_chunk(png_ptr, png_oFFs, buf, (png_size_t)9);
-}
-#endif
-#ifdef PNG_WRITE_pCAL_SUPPORTED
-/* Write the pCAL chunk (described in the PNG extensions document) */
-void /* PRIVATE */
-png_write_pCAL(png_structrp png_ptr, png_charp purpose, png_int_32 X0,
- png_int_32 X1, int type, int nparams, png_const_charp units,
- png_charpp params)
-{
- png_uint_32 purpose_len;
- png_size_t units_len, total_len;
- png_size_tp params_len;
- png_byte buf[10];
- png_byte new_purpose[80];
- int i;
-
- png_debug1(1, "in png_write_pCAL (%d parameters)", nparams);
-
- if (type >= PNG_EQUATION_LAST)
- png_error(png_ptr, "Unrecognized equation type for pCAL chunk");
-
- purpose_len = png_check_keyword(png_ptr, purpose, new_purpose);
-
- if (purpose_len == 0)
- png_error(png_ptr, "pCAL: invalid keyword");
-
- ++purpose_len; /* terminator */
-
- png_debug1(3, "pCAL purpose length = %d", (int)purpose_len);
- units_len = strlen(units) + (nparams == 0 ? 0 : 1);
- png_debug1(3, "pCAL units length = %d", (int)units_len);
- total_len = purpose_len + units_len + 10;
-
- params_len = (png_size_tp)png_malloc(png_ptr,
- (png_alloc_size_t)(nparams * (sizeof (png_size_t))));
-
- /* Find the length of each parameter, making sure we don't count the
- * null terminator for the last parameter.
- */
- for (i = 0; i < nparams; i++)
- {
- params_len[i] = strlen(params[i]) + (i == nparams - 1 ? 0 : 1);
- png_debug2(3, "pCAL parameter %d length = %lu", i,
- (unsigned long)params_len[i]);
- total_len += params_len[i];
- }
-
- png_debug1(3, "pCAL total length = %d", (int)total_len);
- png_write_chunk_header(png_ptr, png_pCAL, (png_uint_32)total_len);
- png_write_chunk_data(png_ptr, new_purpose, purpose_len);
- png_save_int_32(buf, X0);
- png_save_int_32(buf + 4, X1);
- buf[8] = (png_byte)type;
- buf[9] = (png_byte)nparams;
- png_write_chunk_data(png_ptr, buf, (png_size_t)10);
- png_write_chunk_data(png_ptr, (png_const_bytep)units, (png_size_t)units_len);
-
- for (i = 0; i < nparams; i++)
- {
- png_write_chunk_data(png_ptr, (png_const_bytep)params[i], params_len[i]);
- }
-
- png_free(png_ptr, params_len);
- png_write_chunk_end(png_ptr);
-}
-#endif
-
-#ifdef PNG_WRITE_sCAL_SUPPORTED
-/* Write the sCAL chunk */
-void /* PRIVATE */
-png_write_sCAL_s(png_structrp png_ptr, int unit, png_const_charp width,
- png_const_charp height)
-{
- png_byte buf[64];
- png_size_t wlen, hlen, total_len;
-
- png_debug(1, "in png_write_sCAL_s");
-
- wlen = strlen(width);
- hlen = strlen(height);
- total_len = wlen + hlen + 2;
-
- if (total_len > 64)
- {
- png_warning(png_ptr, "Can't write sCAL (buffer too small)");
- return;
- }
-
- buf[0] = (png_byte)unit;
- memcpy(buf + 1, width, wlen + 1); /* Append the '\0' here */
- memcpy(buf + wlen + 2, height, hlen); /* Do NOT append the '\0' here */
-
- png_debug1(3, "sCAL total length = %u", (unsigned int)total_len);
- png_write_complete_chunk(png_ptr, png_sCAL, buf, total_len);
-}
-#endif
-
-#ifdef PNG_WRITE_pHYs_SUPPORTED
-/* Write the pHYs chunk */
-void /* PRIVATE */
-png_write_pHYs(png_structrp png_ptr, png_uint_32 x_pixels_per_unit,
- png_uint_32 y_pixels_per_unit,
- int unit_type)
-{
- png_byte buf[9];
-
- png_debug(1, "in png_write_pHYs");
-
- if (unit_type >= PNG_RESOLUTION_LAST)
- png_warning(png_ptr, "Unrecognized unit type for pHYs chunk");
-
- png_save_uint_32(buf, x_pixels_per_unit);
- png_save_uint_32(buf + 4, y_pixels_per_unit);
- buf[8] = (png_byte)unit_type;
-
- png_write_complete_chunk(png_ptr, png_pHYs, buf, (png_size_t)9);
-}
-#endif
-
-#ifdef PNG_WRITE_tIME_SUPPORTED
-/* Write the tIME chunk. Use either png_convert_from_struct_tm()
- * or png_convert_from_time_t(), or fill in the structure yourself.
- */
-void /* PRIVATE */
-png_write_tIME(png_structrp png_ptr, png_const_timep mod_time)
-{
- png_byte buf[7];
-
- png_debug(1, "in png_write_tIME");
-
- if (mod_time->month > 12 || mod_time->month < 1 ||
- mod_time->day > 31 || mod_time->day < 1 ||
- mod_time->hour > 23 || mod_time->second > 60)
- {
- png_warning(png_ptr, "Invalid time specified for tIME chunk");
- return;
- }
-
- png_save_uint_16(buf, mod_time->year);
- buf[2] = mod_time->month;
- buf[3] = mod_time->day;
- buf[4] = mod_time->hour;
- buf[5] = mod_time->minute;
- buf[6] = mod_time->second;
-
- png_write_complete_chunk(png_ptr, png_tIME, buf, (png_size_t)7);
-}
-#endif
-
-/* Initializes the row writing capability of libpng */
-void /* PRIVATE */
-png_write_start_row(png_structrp png_ptr)
-{
-#ifdef PNG_WRITE_INTERLACING_SUPPORTED
- /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
-
- /* Start of interlace block */
- static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
-
- /* Offset to next interlace block */
- static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
-
- /* Start of interlace block in the y direction */
- static PNG_CONST png_byte png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
-
- /* Offset to next interlace block in the y direction */
- static PNG_CONST png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
-#endif
-
- png_alloc_size_t buf_size;
- int usr_pixel_depth;
-
- png_debug(1, "in png_write_start_row");
-
- usr_pixel_depth = png_ptr->usr_channels * png_ptr->usr_bit_depth;
- buf_size = PNG_ROWBYTES(usr_pixel_depth, png_ptr->width) + 1;
-
- /* 1.5.6: added to allow checking in the row write code. */
- png_ptr->transformed_pixel_depth = png_ptr->pixel_depth;
- png_ptr->maximum_pixel_depth = (png_byte)usr_pixel_depth;
-
- /* Set up row buffer */
- png_ptr->row_buf = (png_bytep)png_malloc(png_ptr, buf_size);
-
- png_ptr->row_buf[0] = PNG_FILTER_VALUE_NONE;
-
-#ifdef PNG_WRITE_FILTER_SUPPORTED
- /* Set up filtering buffer, if using this filter */
- if (png_ptr->do_filter & PNG_FILTER_SUB)
- {
- png_ptr->sub_row = (png_bytep)png_malloc(png_ptr, png_ptr->rowbytes + 1);
-
- png_ptr->sub_row[0] = PNG_FILTER_VALUE_SUB;
- }
-
- /* We only need to keep the previous row if we are using one of these. */
- if (png_ptr->do_filter & (PNG_FILTER_AVG | PNG_FILTER_UP | PNG_FILTER_PAETH))
- {
- /* Set up previous row buffer */
- png_ptr->prev_row = (png_bytep)png_calloc(png_ptr, buf_size);
-
- if (png_ptr->do_filter & PNG_FILTER_UP)
- {
- png_ptr->up_row = (png_bytep)png_malloc(png_ptr,
- png_ptr->rowbytes + 1);
-
- png_ptr->up_row[0] = PNG_FILTER_VALUE_UP;
- }
-
- if (png_ptr->do_filter & PNG_FILTER_AVG)
- {
- png_ptr->avg_row = (png_bytep)png_malloc(png_ptr,
- png_ptr->rowbytes + 1);
-
- png_ptr->avg_row[0] = PNG_FILTER_VALUE_AVG;
- }
-
- if (png_ptr->do_filter & PNG_FILTER_PAETH)
- {
- png_ptr->paeth_row = (png_bytep)png_malloc(png_ptr,
- png_ptr->rowbytes + 1);
-
- png_ptr->paeth_row[0] = PNG_FILTER_VALUE_PAETH;
- }
- }
-#endif /* PNG_WRITE_FILTER_SUPPORTED */
-
-#ifdef PNG_WRITE_INTERLACING_SUPPORTED
- /* If interlaced, we need to set up width and height of pass */
- if (png_ptr->interlaced)
- {
- if (!(png_ptr->transformations & PNG_INTERLACE))
- {
- png_ptr->num_rows = (png_ptr->height + png_pass_yinc[0] - 1 -
- png_pass_ystart[0]) / png_pass_yinc[0];
-
- png_ptr->usr_width = (png_ptr->width + png_pass_inc[0] - 1 -
- png_pass_start[0]) / png_pass_inc[0];
- }
-
- else
- {
- png_ptr->num_rows = png_ptr->height;
- png_ptr->usr_width = png_ptr->width;
- }
- }
-
- else
-#endif
- {
- png_ptr->num_rows = png_ptr->height;
- png_ptr->usr_width = png_ptr->width;
- }
-}
-
-/* Internal use only. Called when finished processing a row of data. */
-void /* PRIVATE */
-png_write_finish_row(png_structrp png_ptr)
-{
-#ifdef PNG_WRITE_INTERLACING_SUPPORTED
- /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
-
- /* Start of interlace block */
- static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
-
- /* Offset to next interlace block */
- static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
-
- /* Start of interlace block in the y direction */
- static PNG_CONST png_byte png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
-
- /* Offset to next interlace block in the y direction */
- static PNG_CONST png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
-#endif
-
- png_debug(1, "in png_write_finish_row");
-
- /* Next row */
- png_ptr->row_number++;
-
- /* See if we are done */
- if (png_ptr->row_number < png_ptr->num_rows)
- return;
-
-#ifdef PNG_WRITE_INTERLACING_SUPPORTED
- /* If interlaced, go to next pass */
- if (png_ptr->interlaced)
- {
- png_ptr->row_number = 0;
- if (png_ptr->transformations & PNG_INTERLACE)
- {
- png_ptr->pass++;
- }
-
- else
- {
- /* Loop until we find a non-zero width or height pass */
- do
- {
- png_ptr->pass++;
-
- if (png_ptr->pass >= 7)
- break;
-
- png_ptr->usr_width = (png_ptr->width +
- png_pass_inc[png_ptr->pass] - 1 -
- png_pass_start[png_ptr->pass]) /
- png_pass_inc[png_ptr->pass];
-
- png_ptr->num_rows = (png_ptr->height +
- png_pass_yinc[png_ptr->pass] - 1 -
- png_pass_ystart[png_ptr->pass]) /
- png_pass_yinc[png_ptr->pass];
-
- if (png_ptr->transformations & PNG_INTERLACE)
- break;
-
- } while (png_ptr->usr_width == 0 || png_ptr->num_rows == 0);
-
- }
-
- /* Reset the row above the image for the next pass */
- if (png_ptr->pass < 7)
- {
- if (png_ptr->prev_row != NULL)
- memset(png_ptr->prev_row, 0,
- (png_size_t)(PNG_ROWBYTES(png_ptr->usr_channels*
- png_ptr->usr_bit_depth, png_ptr->width)) + 1);
-
- return;
- }
- }
-#endif
-
- /* If we get here, we've just written the last row, so we need
- to flush the compressor */
- png_compress_IDAT(png_ptr, NULL, 0, Z_FINISH);
-}
-
-#ifdef PNG_WRITE_INTERLACING_SUPPORTED
-/* Pick out the correct pixels for the interlace pass.
- * The basic idea here is to go through the row with a source
- * pointer and a destination pointer (sp and dp), and copy the
- * correct pixels for the pass. As the row gets compacted,
- * sp will always be >= dp, so we should never overwrite anything.
- * See the default: case for the easiest code to understand.
- */
-void /* PRIVATE */
-png_do_write_interlace(png_row_infop row_info, png_bytep row, int pass)
-{
- /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
-
- /* Start of interlace block */
- static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
-
- /* Offset to next interlace block */
- static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
-
- png_debug(1, "in png_do_write_interlace");
-
- /* We don't have to do anything on the last pass (6) */
- if (pass < 6)
- {
- /* Each pixel depth is handled separately */
- switch (row_info->pixel_depth)
- {
- case 1:
- {
- png_bytep sp;
- png_bytep dp;
- int shift;
- int d;
- int value;
- png_uint_32 i;
- png_uint_32 row_width = row_info->width;
-
- dp = row;
- d = 0;
- shift = 7;
-
- for (i = png_pass_start[pass]; i < row_width;
- i += png_pass_inc[pass])
- {
- sp = row + (png_size_t)(i >> 3);
- value = (int)(*sp >> (7 - (int)(i & 0x07))) & 0x01;
- d |= (value << shift);
-
- if (shift == 0)
- {
- shift = 7;
- *dp++ = (png_byte)d;
- d = 0;
- }
-
- else
- shift--;
-
- }
- if (shift != 7)
- *dp = (png_byte)d;
-
- break;
- }
-
- case 2:
- {
- png_bytep sp;
- png_bytep dp;
- int shift;
- int d;
- int value;
- png_uint_32 i;
- png_uint_32 row_width = row_info->width;
-
- dp = row;
- shift = 6;
- d = 0;
-
- for (i = png_pass_start[pass]; i < row_width;
- i += png_pass_inc[pass])
- {
- sp = row + (png_size_t)(i >> 2);
- value = (*sp >> ((3 - (int)(i & 0x03)) << 1)) & 0x03;
- d |= (value << shift);
-
- if (shift == 0)
- {
- shift = 6;
- *dp++ = (png_byte)d;
- d = 0;
- }
-
- else
- shift -= 2;
- }
- if (shift != 6)
- *dp = (png_byte)d;
-
- break;
- }
-
- case 4:
- {
- png_bytep sp;
- png_bytep dp;
- int shift;
- int d;
- int value;
- png_uint_32 i;
- png_uint_32 row_width = row_info->width;
-
- dp = row;
- shift = 4;
- d = 0;
- for (i = png_pass_start[pass]; i < row_width;
- i += png_pass_inc[pass])
- {
- sp = row + (png_size_t)(i >> 1);
- value = (*sp >> ((1 - (int)(i & 0x01)) << 2)) & 0x0f;
- d |= (value << shift);
-
- if (shift == 0)
- {
- shift = 4;
- *dp++ = (png_byte)d;
- d = 0;
- }
-
- else
- shift -= 4;
- }
- if (shift != 4)
- *dp = (png_byte)d;
-
- break;
- }
-
- default:
- {
- png_bytep sp;
- png_bytep dp;
- png_uint_32 i;
- png_uint_32 row_width = row_info->width;
- png_size_t pixel_bytes;
-
- /* Start at the beginning */
- dp = row;
-
- /* Find out how many bytes each pixel takes up */
- pixel_bytes = (row_info->pixel_depth >> 3);
-
- /* Loop through the row, only looking at the pixels that matter */
- for (i = png_pass_start[pass]; i < row_width;
- i += png_pass_inc[pass])
- {
- /* Find out where the original pixel is */
- sp = row + (png_size_t)i * pixel_bytes;
-
- /* Move the pixel */
- if (dp != sp)
- memcpy(dp, sp, pixel_bytes);
-
- /* Next pixel */
- dp += pixel_bytes;
- }
- break;
- }
- }
- /* Set new row width */
- row_info->width = (row_info->width +
- png_pass_inc[pass] - 1 -
- png_pass_start[pass]) /
- png_pass_inc[pass];
-
- row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth,
- row_info->width);
- }
-}
-#endif
-
-/* This filters the row, chooses which filter to use, if it has not already
- * been specified by the application, and then writes the row out with the
- * chosen filter.
- */
-static void png_write_filtered_row(png_structrp png_ptr, png_bytep filtered_row,
- png_size_t row_bytes);
-
-#define PNG_MAXSUM (((png_uint_32)(-1)) >> 1)
-#define PNG_HISHIFT 10
-#define PNG_LOMASK ((png_uint_32)0xffffL)
-#define PNG_HIMASK ((png_uint_32)(~PNG_LOMASK >> PNG_HISHIFT))
-void /* PRIVATE */
-png_write_find_filter(png_structrp png_ptr, png_row_infop row_info)
-{
- png_bytep best_row;
-#ifdef PNG_WRITE_FILTER_SUPPORTED
- png_bytep prev_row, row_buf;
- png_uint_32 mins, bpp;
- png_byte filter_to_do = png_ptr->do_filter;
- png_size_t row_bytes = row_info->rowbytes;
-#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
- int num_p_filters = png_ptr->num_prev_filters;
-#endif
-
- png_debug(1, "in png_write_find_filter");
-
-#ifndef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
- if (png_ptr->row_number == 0 && filter_to_do == PNG_ALL_FILTERS)
- {
- /* These will never be selected so we need not test them. */
- filter_to_do &= ~(PNG_FILTER_UP | PNG_FILTER_PAETH);
- }
-#endif
-
- /* Find out how many bytes offset each pixel is */
- bpp = (row_info->pixel_depth + 7) >> 3;
-
- prev_row = png_ptr->prev_row;
-#endif
- best_row = png_ptr->row_buf;
-#ifdef PNG_WRITE_FILTER_SUPPORTED
- row_buf = best_row;
- mins = PNG_MAXSUM;
-
- /* The prediction method we use is to find which method provides the
- * smallest value when summing the absolute values of the distances
- * from zero, using anything >= 128 as negative numbers. This is known
- * as the "minimum sum of absolute differences" heuristic. Other
- * heuristics are the "weighted minimum sum of absolute differences"
- * (experimental and can in theory improve compression), and the "zlib
- * predictive" method (not implemented yet), which does test compressions
- * of lines using different filter methods, and then chooses the
- * (series of) filter(s) that give minimum compressed data size (VERY
- * computationally expensive).
- *
- * GRR 980525: consider also
- *
- * (1) minimum sum of absolute differences from running average (i.e.,
- * keep running sum of non-absolute differences & count of bytes)
- * [track dispersion, too? restart average if dispersion too large?]
- *
- * (1b) minimum sum of absolute differences from sliding average, probably
- * with window size <= deflate window (usually 32K)
- *
- * (2) minimum sum of squared differences from zero or running average
- * (i.e., ~ root-mean-square approach)
- */
-
-
- /* We don't need to test the 'no filter' case if this is the only filter
- * that has been chosen, as it doesn't actually do anything to the data.
- */
- if ((filter_to_do & PNG_FILTER_NONE) && filter_to_do != PNG_FILTER_NONE)
- {
- png_bytep rp;
- png_uint_32 sum = 0;
- png_size_t i;
- int v;
-
- for (i = 0, rp = row_buf + 1; i < row_bytes; i++, rp++)
- {
- v = *rp;
- sum += (v < 128) ? v : 256 - v;
- }
-
-#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
- if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
- {
- png_uint_32 sumhi, sumlo;
- int j;
- sumlo = sum & PNG_LOMASK;
- sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK; /* Gives us some footroom */
-
- /* Reduce the sum if we match any of the previous rows */
- for (j = 0; j < num_p_filters; j++)
- {
- if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_NONE)
- {
- sumlo = (sumlo * png_ptr->filter_weights[j]) >>
- PNG_WEIGHT_SHIFT;
-
- sumhi = (sumhi * png_ptr->filter_weights[j]) >>
- PNG_WEIGHT_SHIFT;
- }
- }
-
- /* Factor in the cost of this filter (this is here for completeness,
- * but it makes no sense to have a "cost" for the NONE filter, as
- * it has the minimum possible computational cost - none).
- */
- sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_NONE]) >>
- PNG_COST_SHIFT;
-
- sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_NONE]) >>
- PNG_COST_SHIFT;
-
- if (sumhi > PNG_HIMASK)
- sum = PNG_MAXSUM;
-
- else
- sum = (sumhi << PNG_HISHIFT) + sumlo;
- }
-#endif
- mins = sum;
- }
-
- /* Sub filter */
- if (filter_to_do == PNG_FILTER_SUB)
- /* It's the only filter so no testing is needed */
- {
- png_bytep rp, lp, dp;
- png_size_t i;
-
- for (i = 0, rp = row_buf + 1, dp = png_ptr->sub_row + 1; i < bpp;
- i++, rp++, dp++)
- {
- *dp = *rp;
- }
-
- for (lp = row_buf + 1; i < row_bytes;
- i++, rp++, lp++, dp++)
- {
- *dp = (png_byte)(((int)*rp - (int)*lp) & 0xff);
- }
-
- best_row = png_ptr->sub_row;
- }
-
- else if (filter_to_do & PNG_FILTER_SUB)
- {
- png_bytep rp, dp, lp;
- png_uint_32 sum = 0, lmins = mins;
- png_size_t i;
- int v;
-
-#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
- /* We temporarily increase the "minimum sum" by the factor we
- * would reduce the sum of this filter, so that we can do the
- * early exit comparison without scaling the sum each time.
- */
- if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
- {
- int j;
- png_uint_32 lmhi, lmlo;
- lmlo = lmins & PNG_LOMASK;
- lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;
-
- for (j = 0; j < num_p_filters; j++)
- {
- if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_SUB)
- {
- lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
- PNG_WEIGHT_SHIFT;
-
- lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
- PNG_WEIGHT_SHIFT;
- }
- }
-
- lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>
- PNG_COST_SHIFT;
-
- lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>
- PNG_COST_SHIFT;
-
- if (lmhi > PNG_HIMASK)
- lmins = PNG_MAXSUM;
-
- else
- lmins = (lmhi << PNG_HISHIFT) + lmlo;
- }
-#endif
-
- for (i = 0, rp = row_buf + 1, dp = png_ptr->sub_row + 1; i < bpp;
- i++, rp++, dp++)
- {
- v = *dp = *rp;
-
- sum += (v < 128) ? v : 256 - v;
- }
-
- for (lp = row_buf + 1; i < row_bytes;
- i++, rp++, lp++, dp++)
- {
- v = *dp = (png_byte)(((int)*rp - (int)*lp) & 0xff);
-
- sum += (v < 128) ? v : 256 - v;
-
- if (sum > lmins) /* We are already worse, don't continue. */
- break;
- }
-
-#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
- if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
- {
- int j;
- png_uint_32 sumhi, sumlo;
- sumlo = sum & PNG_LOMASK;
- sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;
-
- for (j = 0; j < num_p_filters; j++)
- {
- if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_SUB)
- {
- sumlo = (sumlo * png_ptr->inv_filter_weights[j]) >>
- PNG_WEIGHT_SHIFT;
-
- sumhi = (sumhi * png_ptr->inv_filter_weights[j]) >>
- PNG_WEIGHT_SHIFT;
- }
- }
-
- sumlo = (sumlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>
- PNG_COST_SHIFT;
-
- sumhi = (sumhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>
- PNG_COST_SHIFT;
-
- if (sumhi > PNG_HIMASK)
- sum = PNG_MAXSUM;
-
- else
- sum = (sumhi << PNG_HISHIFT) + sumlo;
- }
-#endif
-
- if (sum < mins)
- {
- mins = sum;
- best_row = png_ptr->sub_row;
- }
- }
-
- /* Up filter */
- if (filter_to_do == PNG_FILTER_UP)
- {
- png_bytep rp, dp, pp;
- png_size_t i;
-
- for (i = 0, rp = row_buf + 1, dp = png_ptr->up_row + 1,
- pp = prev_row + 1; i < row_bytes;
- i++, rp++, pp++, dp++)
- {
- *dp = (png_byte)(((int)*rp - (int)*pp) & 0xff);
- }
-
- best_row = png_ptr->up_row;
- }
-
- else if (filter_to_do & PNG_FILTER_UP)
- {
- png_bytep rp, dp, pp;
- png_uint_32 sum = 0, lmins = mins;
- png_size_t i;
- int v;
-
-
-#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
- if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
- {
- int j;
- png_uint_32 lmhi, lmlo;
- lmlo = lmins & PNG_LOMASK;
- lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;
-
- for (j = 0; j < num_p_filters; j++)
- {
- if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_UP)
- {
- lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
- PNG_WEIGHT_SHIFT;
-
- lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
- PNG_WEIGHT_SHIFT;
- }
- }
-
- lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_UP]) >>
- PNG_COST_SHIFT;
-
- lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_UP]) >>
- PNG_COST_SHIFT;
-
- if (lmhi > PNG_HIMASK)
- lmins = PNG_MAXSUM;
-
- else
- lmins = (lmhi << PNG_HISHIFT) + lmlo;
- }
-#endif
-
- for (i = 0, rp = row_buf + 1, dp = png_ptr->up_row + 1,
- pp = prev_row + 1; i < row_bytes; i++)
- {
- v = *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff);
-
- sum += (v < 128) ? v : 256 - v;
-
- if (sum > lmins) /* We are already worse, don't continue. */
- break;
- }
-
-#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
- if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
- {
- int j;
- png_uint_32 sumhi, sumlo;
- sumlo = sum & PNG_LOMASK;
- sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;
-
- for (j = 0; j < num_p_filters; j++)
- {
- if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_UP)
- {
- sumlo = (sumlo * png_ptr->filter_weights[j]) >>
- PNG_WEIGHT_SHIFT;
-
- sumhi = (sumhi * png_ptr->filter_weights[j]) >>
- PNG_WEIGHT_SHIFT;
- }
- }
-
- sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_UP]) >>
- PNG_COST_SHIFT;
-
- sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_UP]) >>
- PNG_COST_SHIFT;
-
- if (sumhi > PNG_HIMASK)
- sum = PNG_MAXSUM;
-
- else
- sum = (sumhi << PNG_HISHIFT) + sumlo;
- }
-#endif
-
- if (sum < mins)
- {
- mins = sum;
- best_row = png_ptr->up_row;
- }
- }
-
- /* Avg filter */
- if (filter_to_do == PNG_FILTER_AVG)
- {
- png_bytep rp, dp, pp, lp;
- png_uint_32 i;
-
- for (i = 0, rp = row_buf + 1, dp = png_ptr->avg_row + 1,
- pp = prev_row + 1; i < bpp; i++)
- {
- *dp++ = (png_byte)(((int)*rp++ - ((int)*pp++ / 2)) & 0xff);
- }
-
- for (lp = row_buf + 1; i < row_bytes; i++)
- {
- *dp++ = (png_byte)(((int)*rp++ - (((int)*pp++ + (int)*lp++) / 2))
- & 0xff);
- }
- best_row = png_ptr->avg_row;
- }
-
- else if (filter_to_do & PNG_FILTER_AVG)
- {
- png_bytep rp, dp, pp, lp;
- png_uint_32 sum = 0, lmins = mins;
- png_size_t i;
- int v;
-
-#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
- if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
- {
- int j;
- png_uint_32 lmhi, lmlo;
- lmlo = lmins & PNG_LOMASK;
- lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;
-
- for (j = 0; j < num_p_filters; j++)
- {
- if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_AVG)
- {
- lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
- PNG_WEIGHT_SHIFT;
-
- lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
- PNG_WEIGHT_SHIFT;
- }
- }
-
- lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_AVG]) >>
- PNG_COST_SHIFT;
-
- lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_AVG]) >>
- PNG_COST_SHIFT;
-
- if (lmhi > PNG_HIMASK)
- lmins = PNG_MAXSUM;
-
- else
- lmins = (lmhi << PNG_HISHIFT) + lmlo;
- }
-#endif
-
- for (i = 0, rp = row_buf + 1, dp = png_ptr->avg_row + 1,
- pp = prev_row + 1; i < bpp; i++)
- {
- v = *dp++ = (png_byte)(((int)*rp++ - ((int)*pp++ / 2)) & 0xff);
-
- sum += (v < 128) ? v : 256 - v;
- }
-
- for (lp = row_buf + 1; i < row_bytes; i++)
- {
- v = *dp++ =
- (png_byte)(((int)*rp++ - (((int)*pp++ + (int)*lp++) / 2)) & 0xff);
-
- sum += (v < 128) ? v : 256 - v;
-
- if (sum > lmins) /* We are already worse, don't continue. */
- break;
- }
-
-#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
- if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
- {
- int j;
- png_uint_32 sumhi, sumlo;
- sumlo = sum & PNG_LOMASK;
- sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;
-
- for (j = 0; j < num_p_filters; j++)
- {
- if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_NONE)
- {
- sumlo = (sumlo * png_ptr->filter_weights[j]) >>
- PNG_WEIGHT_SHIFT;
-
- sumhi = (sumhi * png_ptr->filter_weights[j]) >>
- PNG_WEIGHT_SHIFT;
- }
- }
-
- sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_AVG]) >>
- PNG_COST_SHIFT;
-
- sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_AVG]) >>
- PNG_COST_SHIFT;
-
- if (sumhi > PNG_HIMASK)
- sum = PNG_MAXSUM;
-
- else
- sum = (sumhi << PNG_HISHIFT) + sumlo;
- }
-#endif
-
- if (sum < mins)
- {
- mins = sum;
- best_row = png_ptr->avg_row;
- }
- }
-
- /* Paeth filter */
- if (filter_to_do == PNG_FILTER_PAETH)
- {
- png_bytep rp, dp, pp, cp, lp;
- png_size_t i;
-
- for (i = 0, rp = row_buf + 1, dp = png_ptr->paeth_row + 1,
- pp = prev_row + 1; i < bpp; i++)
- {
- *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff);
- }
-
- for (lp = row_buf + 1, cp = prev_row + 1; i < row_bytes; i++)
- {
- int a, b, c, pa, pb, pc, p;
-
- b = *pp++;
- c = *cp++;
- a = *lp++;
-
- p = b - c;
- pc = a - c;
-
-#ifdef PNG_USE_ABS
- pa = abs(p);
- pb = abs(pc);
- pc = abs(p + pc);
-#else
- pa = p < 0 ? -p : p;
- pb = pc < 0 ? -pc : pc;
- pc = (p + pc) < 0 ? -(p + pc) : p + pc;
-#endif
-
- p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c;
-
- *dp++ = (png_byte)(((int)*rp++ - p) & 0xff);
- }
- best_row = png_ptr->paeth_row;
- }
-
- else if (filter_to_do & PNG_FILTER_PAETH)
- {
- png_bytep rp, dp, pp, cp, lp;
- png_uint_32 sum = 0, lmins = mins;
- png_size_t i;
- int v;
-
-#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
- if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
- {
- int j;
- png_uint_32 lmhi, lmlo;
- lmlo = lmins & PNG_LOMASK;
- lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;
-
- for (j = 0; j < num_p_filters; j++)
- {
- if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_PAETH)
- {
- lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
- PNG_WEIGHT_SHIFT;
-
- lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
- PNG_WEIGHT_SHIFT;
- }
- }
-
- lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_PAETH]) >>
- PNG_COST_SHIFT;
-
- lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_PAETH]) >>
- PNG_COST_SHIFT;
-
- if (lmhi > PNG_HIMASK)
- lmins = PNG_MAXSUM;
-
- else
- lmins = (lmhi << PNG_HISHIFT) + lmlo;
- }
-#endif
-
- for (i = 0, rp = row_buf + 1, dp = png_ptr->paeth_row + 1,
- pp = prev_row + 1; i < bpp; i++)
- {
- v = *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff);
-
- sum += (v < 128) ? v : 256 - v;
- }
-
- for (lp = row_buf + 1, cp = prev_row + 1; i < row_bytes; i++)
- {
- int a, b, c, pa, pb, pc, p;
-
- b = *pp++;
- c = *cp++;
- a = *lp++;
-
-#ifndef PNG_SLOW_PAETH
- p = b - c;
- pc = a - c;
-#ifdef PNG_USE_ABS
- pa = abs(p);
- pb = abs(pc);
- pc = abs(p + pc);
-#else
- pa = p < 0 ? -p : p;
- pb = pc < 0 ? -pc : pc;
- pc = (p + pc) < 0 ? -(p + pc) : p + pc;
-#endif
- p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c;
-#else /* PNG_SLOW_PAETH */
- p = a + b - c;
- pa = abs(p - a);
- pb = abs(p - b);
- pc = abs(p - c);
-
- if (pa <= pb && pa <= pc)
- p = a;
-
- else if (pb <= pc)
- p = b;
-
- else
- p = c;
-#endif /* PNG_SLOW_PAETH */
-
- v = *dp++ = (png_byte)(((int)*rp++ - p) & 0xff);
-
- sum += (v < 128) ? v : 256 - v;
-
- if (sum > lmins) /* We are already worse, don't continue. */
- break;
- }
-
-#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
- if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
- {
- int j;
- png_uint_32 sumhi, sumlo;
- sumlo = sum & PNG_LOMASK;
- sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;
-
- for (j = 0; j < num_p_filters; j++)
- {
- if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_PAETH)
- {
- sumlo = (sumlo * png_ptr->filter_weights[j]) >>
- PNG_WEIGHT_SHIFT;
-
- sumhi = (sumhi * png_ptr->filter_weights[j]) >>
- PNG_WEIGHT_SHIFT;
- }
- }
-
- sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_PAETH]) >>
- PNG_COST_SHIFT;
-
- sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_PAETH]) >>
- PNG_COST_SHIFT;
-
- if (sumhi > PNG_HIMASK)
- sum = PNG_MAXSUM;
-
- else
- sum = (sumhi << PNG_HISHIFT) + sumlo;
- }
-#endif
-
- if (sum < mins)
- {
- best_row = png_ptr->paeth_row;
- }
- }
-#endif /* PNG_WRITE_FILTER_SUPPORTED */
-
- /* Do the actual writing of the filtered row data from the chosen filter. */
- png_write_filtered_row(png_ptr, best_row, row_info->rowbytes+1);
-
-#ifdef PNG_WRITE_FILTER_SUPPORTED
-#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
- /* Save the type of filter we picked this time for future calculations */
- if (png_ptr->num_prev_filters > 0)
- {
- int j;
-
- for (j = 1; j < num_p_filters; j++)
- {
- png_ptr->prev_filters[j] = png_ptr->prev_filters[j - 1];
- }
-
- png_ptr->prev_filters[j] = best_row[0];
- }
-#endif
-#endif /* PNG_WRITE_FILTER_SUPPORTED */
-}
-
-
-/* Do the actual writing of a previously filtered row. */
-static void
-png_write_filtered_row(png_structrp png_ptr, png_bytep filtered_row,
- png_size_t full_row_length/*includes filter byte*/)
-{
- png_debug(1, "in png_write_filtered_row");
-
- png_debug1(2, "filter = %d", filtered_row[0]);
-
- png_compress_IDAT(png_ptr, filtered_row, full_row_length, Z_NO_FLUSH);
-
- /* Swap the current and previous rows */
- if (png_ptr->prev_row != NULL)
- {
- png_bytep tptr;
-
- tptr = png_ptr->prev_row;
- png_ptr->prev_row = png_ptr->row_buf;
- png_ptr->row_buf = tptr;
- }
-
- /* Finish row - updates counters and flushes zlib if last row */
- png_write_finish_row(png_ptr);
-
-#ifdef PNG_WRITE_FLUSH_SUPPORTED
- png_ptr->flush_rows++;
-
- if (png_ptr->flush_dist > 0 &&
- png_ptr->flush_rows >= png_ptr->flush_dist)
- {
- png_write_flush(png_ptr);
- }
-#endif
-}
-#endif /* PNG_WRITE_SUPPORTED */
+
+/* pngwutil.c - utilities to write a PNG file
+ *
+ * Last changed in libpng 1.6.19 [November 12, 2015]
+ * Copyright (c) 1998-2015 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+
+#include "pngpriv.h"
+
+#ifdef PNG_WRITE_SUPPORTED
+
+#ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED
+/* Place a 32-bit number into a buffer in PNG byte order. We work
+ * with unsigned numbers for convenience, although one supported
+ * ancillary chunk uses signed (two's complement) numbers.
+ */
+void PNGAPI
+png_save_uint_32(png_bytep buf, png_uint_32 i)
+{
+ buf[0] = (png_byte)(i >> 24);
+ buf[1] = (png_byte)(i >> 16);
+ buf[2] = (png_byte)(i >> 8);
+ buf[3] = (png_byte)(i );
+}
+
+/* Place a 16-bit number into a buffer in PNG byte order.
+ * The parameter is declared unsigned int, not png_uint_16,
+ * just to avoid potential problems on pre-ANSI C compilers.
+ */
+void PNGAPI
+png_save_uint_16(png_bytep buf, unsigned int i)
+{
+ buf[0] = (png_byte)(i >> 8);
+ buf[1] = (png_byte)(i );
+}
+#endif
+
+/* Simple function to write the signature. If we have already written
+ * the magic bytes of the signature, or more likely, the PNG stream is
+ * being embedded into another stream and doesn't need its own signature,
+ * we should call png_set_sig_bytes() to tell libpng how many of the
+ * bytes have already been written.
+ */
+void PNGAPI
+png_write_sig(png_structrp png_ptr)
+{
+ png_byte png_signature[8] = {137, 80, 78, 71, 13, 10, 26, 10};
+
+#ifdef PNG_IO_STATE_SUPPORTED
+ /* Inform the I/O callback that the signature is being written */
+ png_ptr->io_state = PNG_IO_WRITING | PNG_IO_SIGNATURE;
+#endif
+
+ /* Write the rest of the 8 byte signature */
+ png_write_data(png_ptr, &png_signature[png_ptr->sig_bytes],
+ (png_size_t)(8 - png_ptr->sig_bytes));
+
+ if (png_ptr->sig_bytes < 3)
+ png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE;
+}
+
+/* Write the start of a PNG chunk. The type is the chunk type.
+ * The total_length is the sum of the lengths of all the data you will be
+ * passing in png_write_chunk_data().
+ */
+static void
+png_write_chunk_header(png_structrp png_ptr, png_uint_32 chunk_name,
+ png_uint_32 length)
+{
+ png_byte buf[8];
+
+#if defined(PNG_DEBUG) && (PNG_DEBUG > 0)
+ PNG_CSTRING_FROM_CHUNK(buf, chunk_name);
+ png_debug2(0, "Writing %s chunk, length = %lu", buf, (unsigned long)length);
+#endif
+
+ if (png_ptr == NULL)
+ return;
+
+#ifdef PNG_IO_STATE_SUPPORTED
+ /* Inform the I/O callback that the chunk header is being written.
+ * PNG_IO_CHUNK_HDR requires a single I/O call.
+ */
+ png_ptr->io_state = PNG_IO_WRITING | PNG_IO_CHUNK_HDR;
+#endif
+
+ /* Write the length and the chunk name */
+ png_save_uint_32(buf, length);
+ png_save_uint_32(buf + 4, chunk_name);
+ png_write_data(png_ptr, buf, 8);
+
+ /* Put the chunk name into png_ptr->chunk_name */
+ png_ptr->chunk_name = chunk_name;
+
+ /* Reset the crc and run it over the chunk name */
+ png_reset_crc(png_ptr);
+
+ png_calculate_crc(png_ptr, buf + 4, 4);
+
+#ifdef PNG_IO_STATE_SUPPORTED
+ /* Inform the I/O callback that chunk data will (possibly) be written.
+ * PNG_IO_CHUNK_DATA does NOT require a specific number of I/O calls.
+ */
+ png_ptr->io_state = PNG_IO_WRITING | PNG_IO_CHUNK_DATA;
+#endif
+}
+
+void PNGAPI
+png_write_chunk_start(png_structrp png_ptr, png_const_bytep chunk_string,
+ png_uint_32 length)
+{
+ png_write_chunk_header(png_ptr, PNG_CHUNK_FROM_STRING(chunk_string), length);
+}
+
+/* Write the data of a PNG chunk started with png_write_chunk_header().
+ * Note that multiple calls to this function are allowed, and that the
+ * sum of the lengths from these calls *must* add up to the total_length
+ * given to png_write_chunk_header().
+ */
+void PNGAPI
+png_write_chunk_data(png_structrp png_ptr, png_const_bytep data,
+ png_size_t length)
+{
+ /* Write the data, and run the CRC over it */
+ if (png_ptr == NULL)
+ return;
+
+ if (data != NULL && length > 0)
+ {
+ png_write_data(png_ptr, data, length);
+
+ /* Update the CRC after writing the data,
+ * in case the user I/O routine alters it.
+ */
+ png_calculate_crc(png_ptr, data, length);
+ }
+}
+
+/* Finish a chunk started with png_write_chunk_header(). */
+void PNGAPI
+png_write_chunk_end(png_structrp png_ptr)
+{
+ png_byte buf[4];
+
+ if (png_ptr == NULL) return;
+
+#ifdef PNG_IO_STATE_SUPPORTED
+ /* Inform the I/O callback that the chunk CRC is being written.
+ * PNG_IO_CHUNK_CRC requires a single I/O function call.
+ */
+ png_ptr->io_state = PNG_IO_WRITING | PNG_IO_CHUNK_CRC;
+#endif
+
+ /* Write the crc in a single operation */
+ png_save_uint_32(buf, png_ptr->crc);
+
+ png_write_data(png_ptr, buf, (png_size_t)4);
+}
+
+/* Write a PNG chunk all at once. The type is an array of ASCII characters
+ * representing the chunk name. The array must be at least 4 bytes in
+ * length, and does not need to be null terminated. To be safe, pass the
+ * pre-defined chunk names here, and if you need a new one, define it
+ * where the others are defined. The length is the length of the data.
+ * All the data must be present. If that is not possible, use the
+ * png_write_chunk_start(), png_write_chunk_data(), and png_write_chunk_end()
+ * functions instead.
+ */
+static void
+png_write_complete_chunk(png_structrp png_ptr, png_uint_32 chunk_name,
+ png_const_bytep data, png_size_t length)
+{
+ if (png_ptr == NULL)
+ return;
+
+ /* On 64-bit architectures 'length' may not fit in a png_uint_32. */
+ if (length > PNG_UINT_31_MAX)
+ png_error(png_ptr, "length exceeds PNG maximum");
+
+ png_write_chunk_header(png_ptr, chunk_name, (png_uint_32)length);
+ png_write_chunk_data(png_ptr, data, length);
+ png_write_chunk_end(png_ptr);
+}
+
+/* This is the API that calls the internal function above. */
+void PNGAPI
+png_write_chunk(png_structrp png_ptr, png_const_bytep chunk_string,
+ png_const_bytep data, png_size_t length)
+{
+ png_write_complete_chunk(png_ptr, PNG_CHUNK_FROM_STRING(chunk_string), data,
+ length);
+}
+
+/* This is used below to find the size of an image to pass to png_deflate_claim,
+ * so it only needs to be accurate if the size is less than 16384 bytes (the
+ * point at which a lower LZ window size can be used.)
+ */
+static png_alloc_size_t
+png_image_size(png_structrp png_ptr)
+{
+ /* Only return sizes up to the maximum of a png_uint_32; do this by limiting
+ * the width and height used to 15 bits.
+ */
+ png_uint_32 h = png_ptr->height;
+
+ if (png_ptr->rowbytes < 32768 && h < 32768)
+ {
+ if (png_ptr->interlaced != 0)
+ {
+ /* Interlacing makes the image larger because of the replication of
+ * both the filter byte and the padding to a byte boundary.
+ */
+ png_uint_32 w = png_ptr->width;
+ unsigned int pd = png_ptr->pixel_depth;
+ png_alloc_size_t cb_base;
+ int pass;
+
+ for (cb_base=0, pass=0; pass<=6; ++pass)
+ {
+ png_uint_32 pw = PNG_PASS_COLS(w, pass);
+
+ if (pw > 0)
+ cb_base += (PNG_ROWBYTES(pd, pw)+1) * PNG_PASS_ROWS(h, pass);
+ }
+
+ return cb_base;
+ }
+
+ else
+ return (png_ptr->rowbytes+1) * h;
+ }
+
+ else
+ return 0xffffffffU;
+}
+
+#ifdef PNG_WRITE_OPTIMIZE_CMF_SUPPORTED
+ /* This is the code to hack the first two bytes of the deflate stream (the
+ * deflate header) to correct the windowBits value to match the actual data
+ * size. Note that the second argument is the *uncompressed* size but the
+ * first argument is the *compressed* data (and it must be deflate
+ * compressed.)
+ */
+static void
+optimize_cmf(png_bytep data, png_alloc_size_t data_size)
+{
+ /* Optimize the CMF field in the zlib stream. The resultant zlib stream is
+ * still compliant to the stream specification.
+ */
+ if (data_size <= 16384) /* else windowBits must be 15 */
+ {
+ unsigned int z_cmf = data[0]; /* zlib compression method and flags */
+
+ if ((z_cmf & 0x0f) == 8 && (z_cmf & 0xf0) <= 0x70)
+ {
+ unsigned int z_cinfo;
+ unsigned int half_z_window_size;
+
+ z_cinfo = z_cmf >> 4;
+ half_z_window_size = 1U << (z_cinfo + 7);
+
+ if (data_size <= half_z_window_size) /* else no change */
+ {
+ unsigned int tmp;
+
+ do
+ {
+ half_z_window_size >>= 1;
+ --z_cinfo;
+ }
+ while (z_cinfo > 0 && data_size <= half_z_window_size);
+
+ z_cmf = (z_cmf & 0x0f) | (z_cinfo << 4);
+
+ data[0] = (png_byte)z_cmf;
+ tmp = data[1] & 0xe0;
+ tmp += 0x1f - ((z_cmf << 8) + tmp) % 0x1f;
+ data[1] = (png_byte)tmp;
+ }
+ }
+ }
+}
+#endif /* WRITE_OPTIMIZE_CMF */
+
+/* Initialize the compressor for the appropriate type of compression. */
+static int
+png_deflate_claim(png_structrp png_ptr, png_uint_32 owner,
+ png_alloc_size_t data_size)
+{
+ if (png_ptr->zowner != 0)
+ {
+#if defined(PNG_WARNINGS_SUPPORTED) || defined(PNG_ERROR_TEXT_SUPPORTED)
+ char msg[64];
+
+ PNG_STRING_FROM_CHUNK(msg, owner);
+ msg[4] = ':';
+ msg[5] = ' ';
+ PNG_STRING_FROM_CHUNK(msg+6, png_ptr->zowner);
+ /* So the message that results is "<chunk> using zstream"; this is an
+ * internal error, but is very useful for debugging. i18n requirements
+ * are minimal.
+ */
+ (void)png_safecat(msg, (sizeof msg), 10, " using zstream");
+#endif
+#if PNG_RELEASE_BUILD
+ png_warning(png_ptr, msg);
+
+ /* Attempt sane error recovery */
+ if (png_ptr->zowner == png_IDAT) /* don't steal from IDAT */
+ {
+ png_ptr->zstream.msg = PNGZ_MSG_CAST("in use by IDAT");
+ return Z_STREAM_ERROR;
+ }
+
+ png_ptr->zowner = 0;
+#else
+ png_error(png_ptr, msg);
+#endif
+ }
+
+ {
+ int level = png_ptr->zlib_level;
+ int method = png_ptr->zlib_method;
+ int windowBits = png_ptr->zlib_window_bits;
+ int memLevel = png_ptr->zlib_mem_level;
+ int strategy; /* set below */
+ int ret; /* zlib return code */
+
+ if (owner == png_IDAT)
+ {
+ if ((png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_STRATEGY) != 0)
+ strategy = png_ptr->zlib_strategy;
+
+ else if (png_ptr->do_filter != PNG_FILTER_NONE)
+ strategy = PNG_Z_DEFAULT_STRATEGY;
+
+ else
+ strategy = PNG_Z_DEFAULT_NOFILTER_STRATEGY;
+ }
+
+ else
+ {
+#ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
+ level = png_ptr->zlib_text_level;
+ method = png_ptr->zlib_text_method;
+ windowBits = png_ptr->zlib_text_window_bits;
+ memLevel = png_ptr->zlib_text_mem_level;
+ strategy = png_ptr->zlib_text_strategy;
+#else
+ /* If customization is not supported the values all come from the
+ * IDAT values except for the strategy, which is fixed to the
+ * default. (This is the pre-1.6.0 behavior too, although it was
+ * implemented in a very different way.)
+ */
+ strategy = Z_DEFAULT_STRATEGY;
+#endif
+ }
+
+ /* Adjust 'windowBits' down if larger than 'data_size'; to stop this
+ * happening just pass 32768 as the data_size parameter. Notice that zlib
+ * requires an extra 262 bytes in the window in addition to the data to be
+ * able to see the whole of the data, so if data_size+262 takes us to the
+ * next windowBits size we need to fix up the value later. (Because even
+ * though deflate needs the extra window, inflate does not!)
+ */
+ if (data_size <= 16384)
+ {
+ /* IMPLEMENTATION NOTE: this 'half_window_size' stuff is only here to
+ * work round a Microsoft Visual C misbehavior which, contrary to C-90,
+ * widens the result of the following shift to 64-bits if (and,
+ * apparently, only if) it is used in a test.
+ */
+ unsigned int half_window_size = 1U << (windowBits-1);
+
+ while (data_size + 262 <= half_window_size)
+ {
+ half_window_size >>= 1;
+ --windowBits;
+ }
+ }
+
+ /* Check against the previous initialized values, if any. */
+ if ((png_ptr->flags & PNG_FLAG_ZSTREAM_INITIALIZED) != 0 &&
+ (png_ptr->zlib_set_level != level ||
+ png_ptr->zlib_set_method != method ||
+ png_ptr->zlib_set_window_bits != windowBits ||
+ png_ptr->zlib_set_mem_level != memLevel ||
+ png_ptr->zlib_set_strategy != strategy))
+ {
+ if (deflateEnd(&png_ptr->zstream) != Z_OK)
+ png_warning(png_ptr, "deflateEnd failed (ignored)");
+
+ png_ptr->flags &= ~PNG_FLAG_ZSTREAM_INITIALIZED;
+ }
+
+ /* For safety clear out the input and output pointers (currently zlib
+ * doesn't use them on Init, but it might in the future).
+ */
+ png_ptr->zstream.next_in = NULL;
+ png_ptr->zstream.avail_in = 0;
+ png_ptr->zstream.next_out = NULL;
+ png_ptr->zstream.avail_out = 0;
+
+ /* Now initialize if required, setting the new parameters, otherwise just
+ * to a simple reset to the previous parameters.
+ */
+ if ((png_ptr->flags & PNG_FLAG_ZSTREAM_INITIALIZED) != 0)
+ ret = deflateReset(&png_ptr->zstream);
+
+ else
+ {
+ ret = deflateInit2(&png_ptr->zstream, level, method, windowBits,
+ memLevel, strategy);
+
+ if (ret == Z_OK)
+ png_ptr->flags |= PNG_FLAG_ZSTREAM_INITIALIZED;
+ }
+
+ /* The return code is from either deflateReset or deflateInit2; they have
+ * pretty much the same set of error codes.
+ */
+ if (ret == Z_OK)
+ png_ptr->zowner = owner;
+
+ else
+ png_zstream_error(png_ptr, ret);
+
+ return ret;
+ }
+}
+
+/* Clean up (or trim) a linked list of compression buffers. */
+void /* PRIVATE */
+png_free_buffer_list(png_structrp png_ptr, png_compression_bufferp *listp)
+{
+ png_compression_bufferp list = *listp;
+
+ if (list != NULL)
+ {
+ *listp = NULL;
+
+ do
+ {
+ png_compression_bufferp next = list->next;
+
+ png_free(png_ptr, list);
+ list = next;
+ }
+ while (list != NULL);
+ }
+}
+
+#ifdef PNG_WRITE_COMPRESSED_TEXT_SUPPORTED
+/* This pair of functions encapsulates the operation of (a) compressing a
+ * text string, and (b) issuing it later as a series of chunk data writes.
+ * The compression_state structure is shared context for these functions
+ * set up by the caller to allow access to the relevant local variables.
+ *
+ * compression_buffer (new in 1.6.0) is just a linked list of zbuffer_size
+ * temporary buffers. From 1.6.0 it is retained in png_struct so that it will
+ * be correctly freed in the event of a write error (previous implementations
+ * just leaked memory.)
+ */
+typedef struct
+{
+ png_const_bytep input; /* The uncompressed input data */
+ png_alloc_size_t input_len; /* Its length */
+ png_uint_32 output_len; /* Final compressed length */
+ png_byte output[1024]; /* First block of output */
+} compression_state;
+
+static void
+png_text_compress_init(compression_state *comp, png_const_bytep input,
+ png_alloc_size_t input_len)
+{
+ comp->input = input;
+ comp->input_len = input_len;
+ comp->output_len = 0;
+}
+
+/* Compress the data in the compression state input */
+static int
+png_text_compress(png_structrp png_ptr, png_uint_32 chunk_name,
+ compression_state *comp, png_uint_32 prefix_len)
+{
+ int ret;
+
+ /* To find the length of the output it is necessary to first compress the
+ * input. The result is buffered rather than using the two-pass algorithm
+ * that is used on the inflate side; deflate is assumed to be slower and a
+ * PNG writer is assumed to have more memory available than a PNG reader.
+ *
+ * IMPLEMENTATION NOTE: the zlib API deflateBound() can be used to find an
+ * upper limit on the output size, but it is always bigger than the input
+ * size so it is likely to be more efficient to use this linked-list
+ * approach.
+ */
+ ret = png_deflate_claim(png_ptr, chunk_name, comp->input_len);
+
+ if (ret != Z_OK)
+ return ret;
+
+ /* Set up the compression buffers, we need a loop here to avoid overflowing a
+ * uInt. Use ZLIB_IO_MAX to limit the input. The output is always limited
+ * by the output buffer size, so there is no need to check that. Since this
+ * is ANSI-C we know that an 'int', hence a uInt, is always at least 16 bits
+ * in size.
+ */
+ {
+ png_compression_bufferp *end = &png_ptr->zbuffer_list;
+ png_alloc_size_t input_len = comp->input_len; /* may be zero! */
+ png_uint_32 output_len;
+
+ /* zlib updates these for us: */
+ png_ptr->zstream.next_in = PNGZ_INPUT_CAST(comp->input);
+ png_ptr->zstream.avail_in = 0; /* Set below */
+ png_ptr->zstream.next_out = comp->output;
+ png_ptr->zstream.avail_out = (sizeof comp->output);
+
+ output_len = png_ptr->zstream.avail_out;
+
+ do
+ {
+ uInt avail_in = ZLIB_IO_MAX;
+
+ if (avail_in > input_len)
+ avail_in = (uInt)input_len;
+
+ input_len -= avail_in;
+
+ png_ptr->zstream.avail_in = avail_in;
+
+ if (png_ptr->zstream.avail_out == 0)
+ {
+ png_compression_buffer *next;
+
+ /* Chunk data is limited to 2^31 bytes in length, so the prefix
+ * length must be counted here.
+ */
+ if (output_len + prefix_len > PNG_UINT_31_MAX)
+ {
+ ret = Z_MEM_ERROR;
+ break;
+ }
+
+ /* Need a new (malloc'ed) buffer, but there may be one present
+ * already.
+ */
+ next = *end;
+ if (next == NULL)
+ {
+ next = png_voidcast(png_compression_bufferp, png_malloc_base
+ (png_ptr, PNG_COMPRESSION_BUFFER_SIZE(png_ptr)));
+
+ if (next == NULL)
+ {
+ ret = Z_MEM_ERROR;
+ break;
+ }
+
+ /* Link in this buffer (so that it will be freed later) */
+ next->next = NULL;
+ *end = next;
+ }
+
+ png_ptr->zstream.next_out = next->output;
+ png_ptr->zstream.avail_out = png_ptr->zbuffer_size;
+ output_len += png_ptr->zstream.avail_out;
+
+ /* Move 'end' to the next buffer pointer. */
+ end = &next->next;
+ }
+
+ /* Compress the data */
+ ret = deflate(&png_ptr->zstream,
+ input_len > 0 ? Z_NO_FLUSH : Z_FINISH);
+
+ /* Claw back input data that was not consumed (because avail_in is
+ * reset above every time round the loop).
+ */
+ input_len += png_ptr->zstream.avail_in;
+ png_ptr->zstream.avail_in = 0; /* safety */
+ }
+ while (ret == Z_OK);
+
+ /* There may be some space left in the last output buffer. This needs to
+ * be subtracted from output_len.
+ */
+ output_len -= png_ptr->zstream.avail_out;
+ png_ptr->zstream.avail_out = 0; /* safety */
+ comp->output_len = output_len;
+
+ /* Now double check the output length, put in a custom message if it is
+ * too long. Otherwise ensure the z_stream::msg pointer is set to
+ * something.
+ */
+ if (output_len + prefix_len >= PNG_UINT_31_MAX)
+ {
+ png_ptr->zstream.msg = PNGZ_MSG_CAST("compressed data too long");
+ ret = Z_MEM_ERROR;
+ }
+
+ else
+ png_zstream_error(png_ptr, ret);
+
+ /* Reset zlib for another zTXt/iTXt or image data */
+ png_ptr->zowner = 0;
+
+ /* The only success case is Z_STREAM_END, input_len must be 0; if not this
+ * is an internal error.
+ */
+ if (ret == Z_STREAM_END && input_len == 0)
+ {
+#ifdef PNG_WRITE_OPTIMIZE_CMF_SUPPORTED
+ /* Fix up the deflate header, if required */
+ optimize_cmf(comp->output, comp->input_len);
+#endif
+ /* But Z_OK is returned, not Z_STREAM_END; this allows the claim
+ * function above to return Z_STREAM_END on an error (though it never
+ * does in the current versions of zlib.)
+ */
+ return Z_OK;
+ }
+
+ else
+ return ret;
+ }
+}
+
+/* Ship the compressed text out via chunk writes */
+static void
+png_write_compressed_data_out(png_structrp png_ptr, compression_state *comp)
+{
+ png_uint_32 output_len = comp->output_len;
+ png_const_bytep output = comp->output;
+ png_uint_32 avail = (sizeof comp->output);
+ png_compression_buffer *next = png_ptr->zbuffer_list;
+
+ for (;;)
+ {
+ if (avail > output_len)
+ avail = output_len;
+
+ png_write_chunk_data(png_ptr, output, avail);
+
+ output_len -= avail;
+
+ if (output_len == 0 || next == NULL)
+ break;
+
+ avail = png_ptr->zbuffer_size;
+ output = next->output;
+ next = next->next;
+ }
+
+ /* This is an internal error; 'next' must have been NULL! */
+ if (output_len > 0)
+ png_error(png_ptr, "error writing ancillary chunked compressed data");
+}
+#endif /* WRITE_COMPRESSED_TEXT */
+
+#if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_pCAL_SUPPORTED) || \
+ defined(PNG_WRITE_iCCP_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED)
+/* Check that the tEXt or zTXt keyword is valid per PNG 1.0 specification,
+ * and if invalid, correct the keyword rather than discarding the entire
+ * chunk. The PNG 1.0 specification requires keywords 1-79 characters in
+ * length, forbids leading or trailing whitespace, multiple internal spaces,
+ * and the non-break space (0x80) from ISO 8859-1. Returns keyword length.
+ *
+ * The 'new_key' buffer must be 80 characters in size (for the keyword plus a
+ * trailing '\0'). If this routine returns 0 then there was no keyword, or a
+ * valid one could not be generated, and the caller must png_error.
+ */
+static png_uint_32
+png_check_keyword(png_structrp png_ptr, png_const_charp key, png_bytep new_key)
+{
+ png_const_charp orig_key = key;
+ png_uint_32 key_len = 0;
+ int bad_character = 0;
+ int space = 1;
+
+ png_debug(1, "in png_check_keyword");
+
+ if (key == NULL)
+ {
+ *new_key = 0;
+ return 0;
+ }
+
+ while (*key && key_len < 79)
+ {
+ png_byte ch = (png_byte)*key++;
+
+ if ((ch > 32 && ch <= 126) || (ch >= 161 /*&& ch <= 255*/))
+ *new_key++ = ch, ++key_len, space = 0;
+
+ else if (space == 0)
+ {
+ /* A space or an invalid character when one wasn't seen immediately
+ * before; output just a space.
+ */
+ *new_key++ = 32, ++key_len, space = 1;
+
+ /* If the character was not a space then it is invalid. */
+ if (ch != 32)
+ bad_character = ch;
+ }
+
+ else if (bad_character == 0)
+ bad_character = ch; /* just skip it, record the first error */
+ }
+
+ if (key_len > 0 && space != 0) /* trailing space */
+ {
+ --key_len, --new_key;
+ if (bad_character == 0)
+ bad_character = 32;
+ }
+
+ /* Terminate the keyword */
+ *new_key = 0;
+
+ if (key_len == 0)
+ return 0;
+
+#ifdef PNG_WARNINGS_SUPPORTED
+ /* Try to only output one warning per keyword: */
+ if (*key != 0) /* keyword too long */
+ png_warning(png_ptr, "keyword truncated");
+
+ else if (bad_character != 0)
+ {
+ PNG_WARNING_PARAMETERS(p)
+
+ png_warning_parameter(p, 1, orig_key);
+ png_warning_parameter_signed(p, 2, PNG_NUMBER_FORMAT_02x, bad_character);
+
+ png_formatted_warning(png_ptr, p, "keyword \"@1\": bad character '0x@2'");
+ }
+#endif /* WARNINGS */
+
+ return key_len;
+}
+#endif /* WRITE_TEXT || WRITE_pCAL || WRITE_iCCP || WRITE_sPLT */
+
+/* Write the IHDR chunk, and update the png_struct with the necessary
+ * information. Note that the rest of this code depends upon this
+ * information being correct.
+ */
+void /* PRIVATE */
+png_write_IHDR(png_structrp png_ptr, png_uint_32 width, png_uint_32 height,
+ int bit_depth, int color_type, int compression_type, int filter_type,
+ int interlace_type)
+{
+ png_byte buf[13]; /* Buffer to store the IHDR info */
+
+ png_debug(1, "in png_write_IHDR");
+
+ /* Check that we have valid input data from the application info */
+ switch (color_type)
+ {
+ case PNG_COLOR_TYPE_GRAY:
+ switch (bit_depth)
+ {
+ case 1:
+ case 2:
+ case 4:
+ case 8:
+#ifdef PNG_WRITE_16BIT_SUPPORTED
+ case 16:
+#endif
+ png_ptr->channels = 1; break;
+
+ default:
+ png_error(png_ptr,
+ "Invalid bit depth for grayscale image");
+ }
+ break;
+
+ case PNG_COLOR_TYPE_RGB:
+#ifdef PNG_WRITE_16BIT_SUPPORTED
+ if (bit_depth != 8 && bit_depth != 16)
+#else
+ if (bit_depth != 8)
+#endif
+ png_error(png_ptr, "Invalid bit depth for RGB image");
+
+ png_ptr->channels = 3;
+ break;
+
+ case PNG_COLOR_TYPE_PALETTE:
+ switch (bit_depth)
+ {
+ case 1:
+ case 2:
+ case 4:
+ case 8:
+ png_ptr->channels = 1;
+ break;
+
+ default:
+ png_error(png_ptr, "Invalid bit depth for paletted image");
+ }
+ break;
+
+ case PNG_COLOR_TYPE_GRAY_ALPHA:
+ if (bit_depth != 8 && bit_depth != 16)
+ png_error(png_ptr, "Invalid bit depth for grayscale+alpha image");
+
+ png_ptr->channels = 2;
+ break;
+
+ case PNG_COLOR_TYPE_RGB_ALPHA:
+#ifdef PNG_WRITE_16BIT_SUPPORTED
+ if (bit_depth != 8 && bit_depth != 16)
+#else
+ if (bit_depth != 8)
+#endif
+ png_error(png_ptr, "Invalid bit depth for RGBA image");
+
+ png_ptr->channels = 4;
+ break;
+
+ default:
+ png_error(png_ptr, "Invalid image color type specified");
+ }
+
+ if (compression_type != PNG_COMPRESSION_TYPE_BASE)
+ {
+ png_warning(png_ptr, "Invalid compression type specified");
+ compression_type = PNG_COMPRESSION_TYPE_BASE;
+ }
+
+ /* Write filter_method 64 (intrapixel differencing) only if
+ * 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and
+ * 2. Libpng did not write a PNG signature (this filter_method is only
+ * used in PNG datastreams that are embedded in MNG datastreams) and
+ * 3. The application called png_permit_mng_features with a mask that
+ * included PNG_FLAG_MNG_FILTER_64 and
+ * 4. The filter_method is 64 and
+ * 5. The color_type is RGB or RGBA
+ */
+ if (
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+ !((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) != 0 &&
+ ((png_ptr->mode & PNG_HAVE_PNG_SIGNATURE) == 0) &&
+ (color_type == PNG_COLOR_TYPE_RGB ||
+ color_type == PNG_COLOR_TYPE_RGB_ALPHA) &&
+ (filter_type == PNG_INTRAPIXEL_DIFFERENCING)) &&
+#endif
+ filter_type != PNG_FILTER_TYPE_BASE)
+ {
+ png_warning(png_ptr, "Invalid filter type specified");
+ filter_type = PNG_FILTER_TYPE_BASE;
+ }
+
+#ifdef PNG_WRITE_INTERLACING_SUPPORTED
+ if (interlace_type != PNG_INTERLACE_NONE &&
+ interlace_type != PNG_INTERLACE_ADAM7)
+ {
+ png_warning(png_ptr, "Invalid interlace type specified");
+ interlace_type = PNG_INTERLACE_ADAM7;
+ }
+#else
+ interlace_type=PNG_INTERLACE_NONE;
+#endif
+
+ /* Save the relevant information */
+ png_ptr->bit_depth = (png_byte)bit_depth;
+ png_ptr->color_type = (png_byte)color_type;
+ png_ptr->interlaced = (png_byte)interlace_type;
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+ png_ptr->filter_type = (png_byte)filter_type;
+#endif
+ png_ptr->compression_type = (png_byte)compression_type;
+ png_ptr->width = width;
+ png_ptr->height = height;
+
+ png_ptr->pixel_depth = (png_byte)(bit_depth * png_ptr->channels);
+ png_ptr->rowbytes = PNG_ROWBYTES(png_ptr->pixel_depth, width);
+ /* Set the usr info, so any transformations can modify it */
+ png_ptr->usr_width = png_ptr->width;
+ png_ptr->usr_bit_depth = png_ptr->bit_depth;
+ png_ptr->usr_channels = png_ptr->channels;
+
+ /* Pack the header information into the buffer */
+ png_save_uint_32(buf, width);
+ png_save_uint_32(buf + 4, height);
+ buf[8] = (png_byte)bit_depth;
+ buf[9] = (png_byte)color_type;
+ buf[10] = (png_byte)compression_type;
+ buf[11] = (png_byte)filter_type;
+ buf[12] = (png_byte)interlace_type;
+
+ /* Write the chunk */
+ png_write_complete_chunk(png_ptr, png_IHDR, buf, (png_size_t)13);
+
+ if ((png_ptr->do_filter) == PNG_NO_FILTERS)
+ {
+ if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE ||
+ png_ptr->bit_depth < 8)
+ png_ptr->do_filter = PNG_FILTER_NONE;
+
+ else
+ png_ptr->do_filter = PNG_ALL_FILTERS;
+ }
+
+ png_ptr->mode = PNG_HAVE_IHDR; /* not READY_FOR_ZTXT */
+}
+
+/* Write the palette. We are careful not to trust png_color to be in the
+ * correct order for PNG, so people can redefine it to any convenient
+ * structure.
+ */
+void /* PRIVATE */
+png_write_PLTE(png_structrp png_ptr, png_const_colorp palette,
+ png_uint_32 num_pal)
+{
+ png_uint_32 max_palette_length, i;
+ png_const_colorp pal_ptr;
+ png_byte buf[3];
+
+ png_debug(1, "in png_write_PLTE");
+
+ max_palette_length = (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) ?
+ (1 << png_ptr->bit_depth) : PNG_MAX_PALETTE_LENGTH;
+
+ if ((
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+ (png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE) == 0 &&
+#endif
+ num_pal == 0) || num_pal > max_palette_length)
+ {
+ if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+ {
+ png_error(png_ptr, "Invalid number of colors in palette");
+ }
+
+ else
+ {
+ png_warning(png_ptr, "Invalid number of colors in palette");
+ return;
+ }
+ }
+
+ if ((png_ptr->color_type & PNG_COLOR_MASK_COLOR) == 0)
+ {
+ png_warning(png_ptr,
+ "Ignoring request to write a PLTE chunk in grayscale PNG");
+
+ return;
+ }
+
+ png_ptr->num_palette = (png_uint_16)num_pal;
+ png_debug1(3, "num_palette = %d", png_ptr->num_palette);
+
+ png_write_chunk_header(png_ptr, png_PLTE, (png_uint_32)(num_pal * 3));
+#ifdef PNG_POINTER_INDEXING_SUPPORTED
+
+ for (i = 0, pal_ptr = palette; i < num_pal; i++, pal_ptr++)
+ {
+ buf[0] = pal_ptr->red;
+ buf[1] = pal_ptr->green;
+ buf[2] = pal_ptr->blue;
+ png_write_chunk_data(png_ptr, buf, (png_size_t)3);
+ }
+
+#else
+ /* This is a little slower but some buggy compilers need to do this
+ * instead
+ */
+ pal_ptr=palette;
+
+ for (i = 0; i < num_pal; i++)
+ {
+ buf[0] = pal_ptr[i].red;
+ buf[1] = pal_ptr[i].green;
+ buf[2] = pal_ptr[i].blue;
+ png_write_chunk_data(png_ptr, buf, (png_size_t)3);
+ }
+
+#endif
+ png_write_chunk_end(png_ptr);
+ png_ptr->mode |= PNG_HAVE_PLTE;
+}
+
+/* This is similar to png_text_compress, above, except that it does not require
+ * all of the data at once and, instead of buffering the compressed result,
+ * writes it as IDAT chunks. Unlike png_text_compress it *can* png_error out
+ * because it calls the write interface. As a result it does its own error
+ * reporting and does not return an error code. In the event of error it will
+ * just call png_error. The input data length may exceed 32-bits. The 'flush'
+ * parameter is exactly the same as that to deflate, with the following
+ * meanings:
+ *
+ * Z_NO_FLUSH: normal incremental output of compressed data
+ * Z_SYNC_FLUSH: do a SYNC_FLUSH, used by png_write_flush
+ * Z_FINISH: this is the end of the input, do a Z_FINISH and clean up
+ *
+ * The routine manages the acquire and release of the png_ptr->zstream by
+ * checking and (at the end) clearing png_ptr->zowner; it does some sanity
+ * checks on the 'mode' flags while doing this.
+ */
+void /* PRIVATE */
+png_compress_IDAT(png_structrp png_ptr, png_const_bytep input,
+ png_alloc_size_t input_len, int flush)
+{
+ if (png_ptr->zowner != png_IDAT)
+ {
+ /* First time. Ensure we have a temporary buffer for compression and
+ * trim the buffer list if it has more than one entry to free memory.
+ * If 'WRITE_COMPRESSED_TEXT' is not set the list will never have been
+ * created at this point, but the check here is quick and safe.
+ */
+ if (png_ptr->zbuffer_list == NULL)
+ {
+ png_ptr->zbuffer_list = png_voidcast(png_compression_bufferp,
+ png_malloc(png_ptr, PNG_COMPRESSION_BUFFER_SIZE(png_ptr)));
+ png_ptr->zbuffer_list->next = NULL;
+ }
+
+ else
+ png_free_buffer_list(png_ptr, &png_ptr->zbuffer_list->next);
+
+ /* It is a terminal error if we can't claim the zstream. */
+ if (png_deflate_claim(png_ptr, png_IDAT, png_image_size(png_ptr)) != Z_OK)
+ png_error(png_ptr, png_ptr->zstream.msg);
+
+ /* The output state is maintained in png_ptr->zstream, so it must be
+ * initialized here after the claim.
+ */
+ png_ptr->zstream.next_out = png_ptr->zbuffer_list->output;
+ png_ptr->zstream.avail_out = png_ptr->zbuffer_size;
+ }
+
+ /* Now loop reading and writing until all the input is consumed or an error
+ * terminates the operation. The _out values are maintained across calls to
+ * this function, but the input must be reset each time.
+ */
+ png_ptr->zstream.next_in = PNGZ_INPUT_CAST(input);
+ png_ptr->zstream.avail_in = 0; /* set below */
+ for (;;)
+ {
+ int ret;
+
+ /* INPUT: from the row data */
+ uInt avail = ZLIB_IO_MAX;
+
+ if (avail > input_len)
+ avail = (uInt)input_len; /* safe because of the check */
+
+ png_ptr->zstream.avail_in = avail;
+ input_len -= avail;
+
+ ret = deflate(&png_ptr->zstream, input_len > 0 ? Z_NO_FLUSH : flush);
+
+ /* Include as-yet unconsumed input */
+ input_len += png_ptr->zstream.avail_in;
+ png_ptr->zstream.avail_in = 0;
+
+ /* OUTPUT: write complete IDAT chunks when avail_out drops to zero. Note
+ * that these two zstream fields are preserved across the calls, therefore
+ * there is no need to set these up on entry to the loop.
+ */
+ if (png_ptr->zstream.avail_out == 0)
+ {
+ png_bytep data = png_ptr->zbuffer_list->output;
+ uInt size = png_ptr->zbuffer_size;
+
+ /* Write an IDAT containing the data then reset the buffer. The
+ * first IDAT may need deflate header optimization.
+ */
+#ifdef PNG_WRITE_OPTIMIZE_CMF_SUPPORTED
+ if ((png_ptr->mode & PNG_HAVE_IDAT) == 0 &&
+ png_ptr->compression_type == PNG_COMPRESSION_TYPE_BASE)
+ optimize_cmf(data, png_image_size(png_ptr));
+#endif
+
+ png_write_complete_chunk(png_ptr, png_IDAT, data, size);
+ png_ptr->mode |= PNG_HAVE_IDAT;
+
+ png_ptr->zstream.next_out = data;
+ png_ptr->zstream.avail_out = size;
+
+ /* For SYNC_FLUSH or FINISH it is essential to keep calling zlib with
+ * the same flush parameter until it has finished output, for NO_FLUSH
+ * it doesn't matter.
+ */
+ if (ret == Z_OK && flush != Z_NO_FLUSH)
+ continue;
+ }
+
+ /* The order of these checks doesn't matter much; it just affects which
+ * possible error might be detected if multiple things go wrong at once.
+ */
+ if (ret == Z_OK) /* most likely return code! */
+ {
+ /* If all the input has been consumed then just return. If Z_FINISH
+ * was used as the flush parameter something has gone wrong if we get
+ * here.
+ */
+ if (input_len == 0)
+ {
+ if (flush == Z_FINISH)
+ png_error(png_ptr, "Z_OK on Z_FINISH with output space");
+
+ return;
+ }
+ }
+
+ else if (ret == Z_STREAM_END && flush == Z_FINISH)
+ {
+ /* This is the end of the IDAT data; any pending output must be
+ * flushed. For small PNG files we may still be at the beginning.
+ */
+ png_bytep data = png_ptr->zbuffer_list->output;
+ uInt size = png_ptr->zbuffer_size - png_ptr->zstream.avail_out;
+
+#ifdef PNG_WRITE_OPTIMIZE_CMF_SUPPORTED
+ if ((png_ptr->mode & PNG_HAVE_IDAT) == 0 &&
+ png_ptr->compression_type == PNG_COMPRESSION_TYPE_BASE)
+ optimize_cmf(data, png_image_size(png_ptr));
+#endif
+
+ png_write_complete_chunk(png_ptr, png_IDAT, data, size);
+ png_ptr->zstream.avail_out = 0;
+ png_ptr->zstream.next_out = NULL;
+ png_ptr->mode |= PNG_HAVE_IDAT | PNG_AFTER_IDAT;
+
+ png_ptr->zowner = 0; /* Release the stream */
+ return;
+ }
+
+ else
+ {
+ /* This is an error condition. */
+ png_zstream_error(png_ptr, ret);
+ png_error(png_ptr, png_ptr->zstream.msg);
+ }
+ }
+}
+
+/* Write an IEND chunk */
+void /* PRIVATE */
+png_write_IEND(png_structrp png_ptr)
+{
+ png_debug(1, "in png_write_IEND");
+
+ png_write_complete_chunk(png_ptr, png_IEND, NULL, (png_size_t)0);
+ png_ptr->mode |= PNG_HAVE_IEND;
+}
+
+#ifdef PNG_WRITE_gAMA_SUPPORTED
+/* Write a gAMA chunk */
+void /* PRIVATE */
+png_write_gAMA_fixed(png_structrp png_ptr, png_fixed_point file_gamma)
+{
+ png_byte buf[4];
+
+ png_debug(1, "in png_write_gAMA");
+
+ /* file_gamma is saved in 1/100,000ths */
+ png_save_uint_32(buf, (png_uint_32)file_gamma);
+ png_write_complete_chunk(png_ptr, png_gAMA, buf, (png_size_t)4);
+}
+#endif
+
+#ifdef PNG_WRITE_sRGB_SUPPORTED
+/* Write a sRGB chunk */
+void /* PRIVATE */
+png_write_sRGB(png_structrp png_ptr, int srgb_intent)
+{
+ png_byte buf[1];
+
+ png_debug(1, "in png_write_sRGB");
+
+ if (srgb_intent >= PNG_sRGB_INTENT_LAST)
+ png_warning(png_ptr,
+ "Invalid sRGB rendering intent specified");
+
+ buf[0]=(png_byte)srgb_intent;
+ png_write_complete_chunk(png_ptr, png_sRGB, buf, (png_size_t)1);
+}
+#endif
+
+#ifdef PNG_WRITE_iCCP_SUPPORTED
+/* Write an iCCP chunk */
+void /* PRIVATE */
+png_write_iCCP(png_structrp png_ptr, png_const_charp name,
+ png_const_bytep profile)
+{
+ png_uint_32 name_len;
+ png_uint_32 profile_len;
+ png_byte new_name[81]; /* 1 byte for the compression byte */
+ compression_state comp;
+ png_uint_32 temp;
+
+ png_debug(1, "in png_write_iCCP");
+
+ /* These are all internal problems: the profile should have been checked
+ * before when it was stored.
+ */
+ if (profile == NULL)
+ png_error(png_ptr, "No profile for iCCP chunk"); /* internal error */
+
+ profile_len = png_get_uint_32(profile);
+
+ if (profile_len < 132)
+ png_error(png_ptr, "ICC profile too short");
+
+ temp = (png_uint_32) (*(profile+8));
+ if (temp > 3 && (profile_len & 0x03))
+ png_error(png_ptr, "ICC profile length invalid (not a multiple of 4)");
+
+ {
+ png_uint_32 embedded_profile_len = png_get_uint_32(profile);
+
+ if (profile_len != embedded_profile_len)
+ png_error(png_ptr, "Profile length does not match profile");
+ }
+
+ name_len = png_check_keyword(png_ptr, name, new_name);
+
+ if (name_len == 0)
+ png_error(png_ptr, "iCCP: invalid keyword");
+
+ new_name[++name_len] = PNG_COMPRESSION_TYPE_BASE;
+
+ /* Make sure we include the NULL after the name and the compression type */
+ ++name_len;
+
+ png_text_compress_init(&comp, profile, profile_len);
+
+ /* Allow for keyword terminator and compression byte */
+ if (png_text_compress(png_ptr, png_iCCP, &comp, name_len) != Z_OK)
+ png_error(png_ptr, png_ptr->zstream.msg);
+
+ png_write_chunk_header(png_ptr, png_iCCP, name_len + comp.output_len);
+
+ png_write_chunk_data(png_ptr, new_name, name_len);
+
+ png_write_compressed_data_out(png_ptr, &comp);
+
+ png_write_chunk_end(png_ptr);
+}
+#endif
+
+#ifdef PNG_WRITE_sPLT_SUPPORTED
+/* Write a sPLT chunk */
+void /* PRIVATE */
+png_write_sPLT(png_structrp png_ptr, png_const_sPLT_tp spalette)
+{
+ png_uint_32 name_len;
+ png_byte new_name[80];
+ png_byte entrybuf[10];
+ png_size_t entry_size = (spalette->depth == 8 ? 6 : 10);
+ png_size_t palette_size = entry_size * spalette->nentries;
+ png_sPLT_entryp ep;
+#ifndef PNG_POINTER_INDEXING_SUPPORTED
+ int i;
+#endif
+
+ png_debug(1, "in png_write_sPLT");
+
+ name_len = png_check_keyword(png_ptr, spalette->name, new_name);
+
+ if (name_len == 0)
+ png_error(png_ptr, "sPLT: invalid keyword");
+
+ /* Make sure we include the NULL after the name */
+ png_write_chunk_header(png_ptr, png_sPLT,
+ (png_uint_32)(name_len + 2 + palette_size));
+
+ png_write_chunk_data(png_ptr, (png_bytep)new_name,
+ (png_size_t)(name_len + 1));
+
+ png_write_chunk_data(png_ptr, &spalette->depth, (png_size_t)1);
+
+ /* Loop through each palette entry, writing appropriately */
+#ifdef PNG_POINTER_INDEXING_SUPPORTED
+ for (ep = spalette->entries; ep<spalette->entries + spalette->nentries; ep++)
+ {
+ if (spalette->depth == 8)
+ {
+ entrybuf[0] = (png_byte)ep->red;
+ entrybuf[1] = (png_byte)ep->green;
+ entrybuf[2] = (png_byte)ep->blue;
+ entrybuf[3] = (png_byte)ep->alpha;
+ png_save_uint_16(entrybuf + 4, ep->frequency);
+ }
+
+ else
+ {
+ png_save_uint_16(entrybuf + 0, ep->red);
+ png_save_uint_16(entrybuf + 2, ep->green);
+ png_save_uint_16(entrybuf + 4, ep->blue);
+ png_save_uint_16(entrybuf + 6, ep->alpha);
+ png_save_uint_16(entrybuf + 8, ep->frequency);
+ }
+
+ png_write_chunk_data(png_ptr, entrybuf, entry_size);
+ }
+#else
+ ep=spalette->entries;
+ for (i = 0; i>spalette->nentries; i++)
+ {
+ if (spalette->depth == 8)
+ {
+ entrybuf[0] = (png_byte)ep[i].red;
+ entrybuf[1] = (png_byte)ep[i].green;
+ entrybuf[2] = (png_byte)ep[i].blue;
+ entrybuf[3] = (png_byte)ep[i].alpha;
+ png_save_uint_16(entrybuf + 4, ep[i].frequency);
+ }
+
+ else
+ {
+ png_save_uint_16(entrybuf + 0, ep[i].red);
+ png_save_uint_16(entrybuf + 2, ep[i].green);
+ png_save_uint_16(entrybuf + 4, ep[i].blue);
+ png_save_uint_16(entrybuf + 6, ep[i].alpha);
+ png_save_uint_16(entrybuf + 8, ep[i].frequency);
+ }
+
+ png_write_chunk_data(png_ptr, entrybuf, entry_size);
+ }
+#endif
+
+ png_write_chunk_end(png_ptr);
+}
+#endif
+
+#ifdef PNG_WRITE_sBIT_SUPPORTED
+/* Write the sBIT chunk */
+void /* PRIVATE */
+png_write_sBIT(png_structrp png_ptr, png_const_color_8p sbit, int color_type)
+{
+ png_byte buf[4];
+ png_size_t size;
+
+ png_debug(1, "in png_write_sBIT");
+
+ /* Make sure we don't depend upon the order of PNG_COLOR_8 */
+ if ((color_type & PNG_COLOR_MASK_COLOR) != 0)
+ {
+ png_byte maxbits;
+
+ maxbits = (png_byte)(color_type==PNG_COLOR_TYPE_PALETTE ? 8 :
+ png_ptr->usr_bit_depth);
+
+ if (sbit->red == 0 || sbit->red > maxbits ||
+ sbit->green == 0 || sbit->green > maxbits ||
+ sbit->blue == 0 || sbit->blue > maxbits)
+ {
+ png_warning(png_ptr, "Invalid sBIT depth specified");
+ return;
+ }
+
+ buf[0] = sbit->red;
+ buf[1] = sbit->green;
+ buf[2] = sbit->blue;
+ size = 3;
+ }
+
+ else
+ {
+ if (sbit->gray == 0 || sbit->gray > png_ptr->usr_bit_depth)
+ {
+ png_warning(png_ptr, "Invalid sBIT depth specified");
+ return;
+ }
+
+ buf[0] = sbit->gray;
+ size = 1;
+ }
+
+ if ((color_type & PNG_COLOR_MASK_ALPHA) != 0)
+ {
+ if (sbit->alpha == 0 || sbit->alpha > png_ptr->usr_bit_depth)
+ {
+ png_warning(png_ptr, "Invalid sBIT depth specified");
+ return;
+ }
+
+ buf[size++] = sbit->alpha;
+ }
+
+ png_write_complete_chunk(png_ptr, png_sBIT, buf, size);
+}
+#endif
+
+#ifdef PNG_WRITE_cHRM_SUPPORTED
+/* Write the cHRM chunk */
+void /* PRIVATE */
+png_write_cHRM_fixed(png_structrp png_ptr, const png_xy *xy)
+{
+ png_byte buf[32];
+
+ png_debug(1, "in png_write_cHRM");
+
+ /* Each value is saved in 1/100,000ths */
+ png_save_int_32(buf, xy->whitex);
+ png_save_int_32(buf + 4, xy->whitey);
+
+ png_save_int_32(buf + 8, xy->redx);
+ png_save_int_32(buf + 12, xy->redy);
+
+ png_save_int_32(buf + 16, xy->greenx);
+ png_save_int_32(buf + 20, xy->greeny);
+
+ png_save_int_32(buf + 24, xy->bluex);
+ png_save_int_32(buf + 28, xy->bluey);
+
+ png_write_complete_chunk(png_ptr, png_cHRM, buf, 32);
+}
+#endif
+
+#ifdef PNG_WRITE_tRNS_SUPPORTED
+/* Write the tRNS chunk */
+void /* PRIVATE */
+png_write_tRNS(png_structrp png_ptr, png_const_bytep trans_alpha,
+ png_const_color_16p tran, int num_trans, int color_type)
+{
+ png_byte buf[6];
+
+ png_debug(1, "in png_write_tRNS");
+
+ if (color_type == PNG_COLOR_TYPE_PALETTE)
+ {
+ if (num_trans <= 0 || num_trans > (int)png_ptr->num_palette)
+ {
+ png_app_warning(png_ptr,
+ "Invalid number of transparent colors specified");
+ return;
+ }
+
+ /* Write the chunk out as it is */
+ png_write_complete_chunk(png_ptr, png_tRNS, trans_alpha,
+ (png_size_t)num_trans);
+ }
+
+ else if (color_type == PNG_COLOR_TYPE_GRAY)
+ {
+ /* One 16-bit value */
+ if (tran->gray >= (1 << png_ptr->bit_depth))
+ {
+ png_app_warning(png_ptr,
+ "Ignoring attempt to write tRNS chunk out-of-range for bit_depth");
+
+ return;
+ }
+
+ png_save_uint_16(buf, tran->gray);
+ png_write_complete_chunk(png_ptr, png_tRNS, buf, (png_size_t)2);
+ }
+
+ else if (color_type == PNG_COLOR_TYPE_RGB)
+ {
+ /* Three 16-bit values */
+ png_save_uint_16(buf, tran->red);
+ png_save_uint_16(buf + 2, tran->green);
+ png_save_uint_16(buf + 4, tran->blue);
+#ifdef PNG_WRITE_16BIT_SUPPORTED
+ if (png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4]) != 0)
+#else
+ if ((buf[0] | buf[2] | buf[4]) != 0)
+#endif
+ {
+ png_app_warning(png_ptr,
+ "Ignoring attempt to write 16-bit tRNS chunk when bit_depth is 8");
+ return;
+ }
+
+ png_write_complete_chunk(png_ptr, png_tRNS, buf, (png_size_t)6);
+ }
+
+ else
+ {
+ png_app_warning(png_ptr, "Can't write tRNS with an alpha channel");
+ }
+}
+#endif
+
+#ifdef PNG_WRITE_bKGD_SUPPORTED
+/* Write the background chunk */
+void /* PRIVATE */
+png_write_bKGD(png_structrp png_ptr, png_const_color_16p back, int color_type)
+{
+ png_byte buf[6];
+
+ png_debug(1, "in png_write_bKGD");
+
+ if (color_type == PNG_COLOR_TYPE_PALETTE)
+ {
+ if (
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+ (png_ptr->num_palette != 0 ||
+ (png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE) == 0) &&
+#endif
+ back->index >= png_ptr->num_palette)
+ {
+ png_warning(png_ptr, "Invalid background palette index");
+ return;
+ }
+
+ buf[0] = back->index;
+ png_write_complete_chunk(png_ptr, png_bKGD, buf, (png_size_t)1);
+ }
+
+ else if ((color_type & PNG_COLOR_MASK_COLOR) != 0)
+ {
+ png_save_uint_16(buf, back->red);
+ png_save_uint_16(buf + 2, back->green);
+ png_save_uint_16(buf + 4, back->blue);
+#ifdef PNG_WRITE_16BIT_SUPPORTED
+ if (png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4]) != 0)
+#else
+ if ((buf[0] | buf[2] | buf[4]) != 0)
+#endif
+ {
+ png_warning(png_ptr,
+ "Ignoring attempt to write 16-bit bKGD chunk when bit_depth is 8");
+
+ return;
+ }
+
+ png_write_complete_chunk(png_ptr, png_bKGD, buf, (png_size_t)6);
+ }
+
+ else
+ {
+ if (back->gray >= (1 << png_ptr->bit_depth))
+ {
+ png_warning(png_ptr,
+ "Ignoring attempt to write bKGD chunk out-of-range for bit_depth");
+
+ return;
+ }
+
+ png_save_uint_16(buf, back->gray);
+ png_write_complete_chunk(png_ptr, png_bKGD, buf, (png_size_t)2);
+ }
+}
+#endif
+
+#ifdef PNG_WRITE_hIST_SUPPORTED
+/* Write the histogram */
+void /* PRIVATE */
+png_write_hIST(png_structrp png_ptr, png_const_uint_16p hist, int num_hist)
+{
+ int i;
+ png_byte buf[3];
+
+ png_debug(1, "in png_write_hIST");
+
+ if (num_hist > (int)png_ptr->num_palette)
+ {
+ png_debug2(3, "num_hist = %d, num_palette = %d", num_hist,
+ png_ptr->num_palette);
+
+ png_warning(png_ptr, "Invalid number of histogram entries specified");
+ return;
+ }
+
+ png_write_chunk_header(png_ptr, png_hIST, (png_uint_32)(num_hist * 2));
+
+ for (i = 0; i < num_hist; i++)
+ {
+ png_save_uint_16(buf, hist[i]);
+ png_write_chunk_data(png_ptr, buf, (png_size_t)2);
+ }
+
+ png_write_chunk_end(png_ptr);
+}
+#endif
+
+#ifdef PNG_WRITE_tEXt_SUPPORTED
+/* Write a tEXt chunk */
+void /* PRIVATE */
+png_write_tEXt(png_structrp png_ptr, png_const_charp key, png_const_charp text,
+ png_size_t text_len)
+{
+ png_uint_32 key_len;
+ png_byte new_key[80];
+
+ png_debug(1, "in png_write_tEXt");
+
+ key_len = png_check_keyword(png_ptr, key, new_key);
+
+ if (key_len == 0)
+ png_error(png_ptr, "tEXt: invalid keyword");
+
+ if (text == NULL || *text == '\0')
+ text_len = 0;
+
+ else
+ text_len = strlen(text);
+
+ if (text_len > PNG_UINT_31_MAX - (key_len+1))
+ png_error(png_ptr, "tEXt: text too long");
+
+ /* Make sure we include the 0 after the key */
+ png_write_chunk_header(png_ptr, png_tEXt,
+ (png_uint_32)/*checked above*/(key_len + text_len + 1));
+ /*
+ * We leave it to the application to meet PNG-1.0 requirements on the
+ * contents of the text. PNG-1.0 through PNG-1.2 discourage the use of
+ * any non-Latin-1 characters except for NEWLINE. ISO PNG will forbid them.
+ * The NUL character is forbidden by PNG-1.0 through PNG-1.2 and ISO PNG.
+ */
+ png_write_chunk_data(png_ptr, new_key, key_len + 1);
+
+ if (text_len != 0)
+ png_write_chunk_data(png_ptr, (png_const_bytep)text, text_len);
+
+ png_write_chunk_end(png_ptr);
+}
+#endif
+
+#ifdef PNG_WRITE_zTXt_SUPPORTED
+/* Write a compressed text chunk */
+void /* PRIVATE */
+png_write_zTXt(png_structrp png_ptr, png_const_charp key, png_const_charp text,
+ int compression)
+{
+ png_uint_32 key_len;
+ png_byte new_key[81];
+ compression_state comp;
+
+ png_debug(1, "in png_write_zTXt");
+
+ if (compression == PNG_TEXT_COMPRESSION_NONE)
+ {
+ png_write_tEXt(png_ptr, key, text, 0);
+ return;
+ }
+
+ if (compression != PNG_TEXT_COMPRESSION_zTXt)
+ png_error(png_ptr, "zTXt: invalid compression type");
+
+ key_len = png_check_keyword(png_ptr, key, new_key);
+
+ if (key_len == 0)
+ png_error(png_ptr, "zTXt: invalid keyword");
+
+ /* Add the compression method and 1 for the keyword separator. */
+ new_key[++key_len] = PNG_COMPRESSION_TYPE_BASE;
+ ++key_len;
+
+ /* Compute the compressed data; do it now for the length */
+ png_text_compress_init(&comp, (png_const_bytep)text,
+ text == NULL ? 0 : strlen(text));
+
+ if (png_text_compress(png_ptr, png_zTXt, &comp, key_len) != Z_OK)
+ png_error(png_ptr, png_ptr->zstream.msg);
+
+ /* Write start of chunk */
+ png_write_chunk_header(png_ptr, png_zTXt, key_len + comp.output_len);
+
+ /* Write key */
+ png_write_chunk_data(png_ptr, new_key, key_len);
+
+ /* Write the compressed data */
+ png_write_compressed_data_out(png_ptr, &comp);
+
+ /* Close the chunk */
+ png_write_chunk_end(png_ptr);
+}
+#endif
+
+#ifdef PNG_WRITE_iTXt_SUPPORTED
+/* Write an iTXt chunk */
+void /* PRIVATE */
+png_write_iTXt(png_structrp png_ptr, int compression, png_const_charp key,
+ png_const_charp lang, png_const_charp lang_key, png_const_charp text)
+{
+ png_uint_32 key_len, prefix_len;
+ png_size_t lang_len, lang_key_len;
+ png_byte new_key[82];
+ compression_state comp;
+
+ png_debug(1, "in png_write_iTXt");
+
+ key_len = png_check_keyword(png_ptr, key, new_key);
+
+ if (key_len == 0)
+ png_error(png_ptr, "iTXt: invalid keyword");
+
+ /* Set the compression flag */
+ switch (compression)
+ {
+ case PNG_ITXT_COMPRESSION_NONE:
+ case PNG_TEXT_COMPRESSION_NONE:
+ compression = new_key[++key_len] = 0; /* no compression */
+ break;
+
+ case PNG_TEXT_COMPRESSION_zTXt:
+ case PNG_ITXT_COMPRESSION_zTXt:
+ compression = new_key[++key_len] = 1; /* compressed */
+ break;
+
+ default:
+ png_error(png_ptr, "iTXt: invalid compression");
+ }
+
+ new_key[++key_len] = PNG_COMPRESSION_TYPE_BASE;
+ ++key_len; /* for the keywod separator */
+
+ /* We leave it to the application to meet PNG-1.0 requirements on the
+ * contents of the text. PNG-1.0 through PNG-1.2 discourage the use of
+ * any non-Latin-1 characters except for NEWLINE. ISO PNG, however,
+ * specifies that the text is UTF-8 and this really doesn't require any
+ * checking.
+ *
+ * The NUL character is forbidden by PNG-1.0 through PNG-1.2 and ISO PNG.
+ *
+ * TODO: validate the language tag correctly (see the spec.)
+ */
+ if (lang == NULL) lang = ""; /* empty language is valid */
+ lang_len = strlen(lang)+1;
+ if (lang_key == NULL) lang_key = ""; /* may be empty */
+ lang_key_len = strlen(lang_key)+1;
+ if (text == NULL) text = ""; /* may be empty */
+
+ prefix_len = key_len;
+ if (lang_len > PNG_UINT_31_MAX-prefix_len)
+ prefix_len = PNG_UINT_31_MAX;
+ else
+ prefix_len = (png_uint_32)(prefix_len + lang_len);
+
+ if (lang_key_len > PNG_UINT_31_MAX-prefix_len)
+ prefix_len = PNG_UINT_31_MAX;
+ else
+ prefix_len = (png_uint_32)(prefix_len + lang_key_len);
+
+ png_text_compress_init(&comp, (png_const_bytep)text, strlen(text));
+
+ if (compression != 0)
+ {
+ if (png_text_compress(png_ptr, png_iTXt, &comp, prefix_len) != Z_OK)
+ png_error(png_ptr, png_ptr->zstream.msg);
+ }
+
+ else
+ {
+ if (comp.input_len > PNG_UINT_31_MAX-prefix_len)
+ png_error(png_ptr, "iTXt: uncompressed text too long");
+
+ /* So the string will fit in a chunk: */
+ comp.output_len = (png_uint_32)/*SAFE*/comp.input_len;
+ }
+
+ png_write_chunk_header(png_ptr, png_iTXt, comp.output_len + prefix_len);
+
+ png_write_chunk_data(png_ptr, new_key, key_len);
+
+ png_write_chunk_data(png_ptr, (png_const_bytep)lang, lang_len);
+
+ png_write_chunk_data(png_ptr, (png_const_bytep)lang_key, lang_key_len);
+
+ if (compression != 0)
+ png_write_compressed_data_out(png_ptr, &comp);
+
+ else
+ png_write_chunk_data(png_ptr, (png_const_bytep)text, comp.output_len);
+
+ png_write_chunk_end(png_ptr);
+}
+#endif
+
+#ifdef PNG_WRITE_oFFs_SUPPORTED
+/* Write the oFFs chunk */
+void /* PRIVATE */
+png_write_oFFs(png_structrp png_ptr, png_int_32 x_offset, png_int_32 y_offset,
+ int unit_type)
+{
+ png_byte buf[9];
+
+ png_debug(1, "in png_write_oFFs");
+
+ if (unit_type >= PNG_OFFSET_LAST)
+ png_warning(png_ptr, "Unrecognized unit type for oFFs chunk");
+
+ png_save_int_32(buf, x_offset);
+ png_save_int_32(buf + 4, y_offset);
+ buf[8] = (png_byte)unit_type;
+
+ png_write_complete_chunk(png_ptr, png_oFFs, buf, (png_size_t)9);
+}
+#endif
+#ifdef PNG_WRITE_pCAL_SUPPORTED
+/* Write the pCAL chunk (described in the PNG extensions document) */
+void /* PRIVATE */
+png_write_pCAL(png_structrp png_ptr, png_charp purpose, png_int_32 X0,
+ png_int_32 X1, int type, int nparams, png_const_charp units,
+ png_charpp params)
+{
+ png_uint_32 purpose_len;
+ png_size_t units_len, total_len;
+ png_size_tp params_len;
+ png_byte buf[10];
+ png_byte new_purpose[80];
+ int i;
+
+ png_debug1(1, "in png_write_pCAL (%d parameters)", nparams);
+
+ if (type >= PNG_EQUATION_LAST)
+ png_error(png_ptr, "Unrecognized equation type for pCAL chunk");
+
+ purpose_len = png_check_keyword(png_ptr, purpose, new_purpose);
+
+ if (purpose_len == 0)
+ png_error(png_ptr, "pCAL: invalid keyword");
+
+ ++purpose_len; /* terminator */
+
+ png_debug1(3, "pCAL purpose length = %d", (int)purpose_len);
+ units_len = strlen(units) + (nparams == 0 ? 0 : 1);
+ png_debug1(3, "pCAL units length = %d", (int)units_len);
+ total_len = purpose_len + units_len + 10;
+
+ params_len = (png_size_tp)png_malloc(png_ptr,
+ (png_alloc_size_t)(nparams * (sizeof (png_size_t))));
+
+ /* Find the length of each parameter, making sure we don't count the
+ * null terminator for the last parameter.
+ */
+ for (i = 0; i < nparams; i++)
+ {
+ params_len[i] = strlen(params[i]) + (i == nparams - 1 ? 0 : 1);
+ png_debug2(3, "pCAL parameter %d length = %lu", i,
+ (unsigned long)params_len[i]);
+ total_len += params_len[i];
+ }
+
+ png_debug1(3, "pCAL total length = %d", (int)total_len);
+ png_write_chunk_header(png_ptr, png_pCAL, (png_uint_32)total_len);
+ png_write_chunk_data(png_ptr, new_purpose, purpose_len);
+ png_save_int_32(buf, X0);
+ png_save_int_32(buf + 4, X1);
+ buf[8] = (png_byte)type;
+ buf[9] = (png_byte)nparams;
+ png_write_chunk_data(png_ptr, buf, (png_size_t)10);
+ png_write_chunk_data(png_ptr, (png_const_bytep)units, (png_size_t)units_len);
+
+ for (i = 0; i < nparams; i++)
+ {
+ png_write_chunk_data(png_ptr, (png_const_bytep)params[i], params_len[i]);
+ }
+
+ png_free(png_ptr, params_len);
+ png_write_chunk_end(png_ptr);
+}
+#endif
+
+#ifdef PNG_WRITE_sCAL_SUPPORTED
+/* Write the sCAL chunk */
+void /* PRIVATE */
+png_write_sCAL_s(png_structrp png_ptr, int unit, png_const_charp width,
+ png_const_charp height)
+{
+ png_byte buf[64];
+ png_size_t wlen, hlen, total_len;
+
+ png_debug(1, "in png_write_sCAL_s");
+
+ wlen = strlen(width);
+ hlen = strlen(height);
+ total_len = wlen + hlen + 2;
+
+ if (total_len > 64)
+ {
+ png_warning(png_ptr, "Can't write sCAL (buffer too small)");
+ return;
+ }
+
+ buf[0] = (png_byte)unit;
+ memcpy(buf + 1, width, wlen + 1); /* Append the '\0' here */
+ memcpy(buf + wlen + 2, height, hlen); /* Do NOT append the '\0' here */
+
+ png_debug1(3, "sCAL total length = %u", (unsigned int)total_len);
+ png_write_complete_chunk(png_ptr, png_sCAL, buf, total_len);
+}
+#endif
+
+#ifdef PNG_WRITE_pHYs_SUPPORTED
+/* Write the pHYs chunk */
+void /* PRIVATE */
+png_write_pHYs(png_structrp png_ptr, png_uint_32 x_pixels_per_unit,
+ png_uint_32 y_pixels_per_unit,
+ int unit_type)
+{
+ png_byte buf[9];
+
+ png_debug(1, "in png_write_pHYs");
+
+ if (unit_type >= PNG_RESOLUTION_LAST)
+ png_warning(png_ptr, "Unrecognized unit type for pHYs chunk");
+
+ png_save_uint_32(buf, x_pixels_per_unit);
+ png_save_uint_32(buf + 4, y_pixels_per_unit);
+ buf[8] = (png_byte)unit_type;
+
+ png_write_complete_chunk(png_ptr, png_pHYs, buf, (png_size_t)9);
+}
+#endif
+
+#ifdef PNG_WRITE_tIME_SUPPORTED
+/* Write the tIME chunk. Use either png_convert_from_struct_tm()
+ * or png_convert_from_time_t(), or fill in the structure yourself.
+ */
+void /* PRIVATE */
+png_write_tIME(png_structrp png_ptr, png_const_timep mod_time)
+{
+ png_byte buf[7];
+
+ png_debug(1, "in png_write_tIME");
+
+ if (mod_time->month > 12 || mod_time->month < 1 ||
+ mod_time->day > 31 || mod_time->day < 1 ||
+ mod_time->hour > 23 || mod_time->second > 60)
+ {
+ png_warning(png_ptr, "Invalid time specified for tIME chunk");
+ return;
+ }
+
+ png_save_uint_16(buf, mod_time->year);
+ buf[2] = mod_time->month;
+ buf[3] = mod_time->day;
+ buf[4] = mod_time->hour;
+ buf[5] = mod_time->minute;
+ buf[6] = mod_time->second;
+
+ png_write_complete_chunk(png_ptr, png_tIME, buf, (png_size_t)7);
+}
+#endif
+
+/* Initializes the row writing capability of libpng */
+void /* PRIVATE */
+png_write_start_row(png_structrp png_ptr)
+{
+#ifdef PNG_WRITE_INTERLACING_SUPPORTED
+ /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
+
+ /* Start of interlace block */
+ static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
+
+ /* Offset to next interlace block */
+ static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
+
+ /* Start of interlace block in the y direction */
+ static PNG_CONST png_byte png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
+
+ /* Offset to next interlace block in the y direction */
+ static PNG_CONST png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
+#endif
+
+ png_alloc_size_t buf_size;
+ int usr_pixel_depth;
+
+#ifdef PNG_WRITE_FILTER_SUPPORTED
+ png_byte filters;
+#endif
+
+ png_debug(1, "in png_write_start_row");
+
+ usr_pixel_depth = png_ptr->usr_channels * png_ptr->usr_bit_depth;
+ buf_size = PNG_ROWBYTES(usr_pixel_depth, png_ptr->width) + 1;
+
+ /* 1.5.6: added to allow checking in the row write code. */
+ png_ptr->transformed_pixel_depth = png_ptr->pixel_depth;
+ png_ptr->maximum_pixel_depth = (png_byte)usr_pixel_depth;
+
+ /* Set up row buffer */
+ png_ptr->row_buf = png_voidcast(png_bytep, png_malloc(png_ptr, buf_size));
+
+ png_ptr->row_buf[0] = PNG_FILTER_VALUE_NONE;
+
+#ifdef PNG_WRITE_FILTER_SUPPORTED
+ filters = png_ptr->do_filter;
+
+ if (png_ptr->height == 1)
+ filters &= 0xff & ~(PNG_FILTER_UP|PNG_FILTER_AVG|PNG_FILTER_PAETH);
+
+ if (png_ptr->width == 1)
+ filters &= 0xff & ~(PNG_FILTER_SUB|PNG_FILTER_AVG|PNG_FILTER_PAETH);
+
+ if (filters == 0)
+ filters = PNG_FILTER_NONE;
+
+ png_ptr->do_filter = filters;
+
+ if (((filters & (PNG_FILTER_SUB | PNG_FILTER_UP | PNG_FILTER_AVG |
+ PNG_FILTER_PAETH)) != 0) && png_ptr->try_row == NULL)
+ {
+ int num_filters = 0;
+
+ png_ptr->try_row = png_voidcast(png_bytep, png_malloc(png_ptr, buf_size));
+
+ if (filters & PNG_FILTER_SUB)
+ num_filters++;
+
+ if (filters & PNG_FILTER_UP)
+ num_filters++;
+
+ if (filters & PNG_FILTER_AVG)
+ num_filters++;
+
+ if (filters & PNG_FILTER_PAETH)
+ num_filters++;
+
+ if (num_filters > 1)
+ png_ptr->tst_row = png_voidcast(png_bytep, png_malloc(png_ptr,
+ buf_size));
+ }
+
+ /* We only need to keep the previous row if we are using one of the following
+ * filters.
+ */
+ if ((filters & (PNG_FILTER_AVG | PNG_FILTER_UP | PNG_FILTER_PAETH)) != 0)
+ png_ptr->prev_row = png_voidcast(png_bytep,
+ png_calloc(png_ptr, buf_size));
+#endif /* WRITE_FILTER */
+
+#ifdef PNG_WRITE_INTERLACING_SUPPORTED
+ /* If interlaced, we need to set up width and height of pass */
+ if (png_ptr->interlaced != 0)
+ {
+ if ((png_ptr->transformations & PNG_INTERLACE) == 0)
+ {
+ png_ptr->num_rows = (png_ptr->height + png_pass_yinc[0] - 1 -
+ png_pass_ystart[0]) / png_pass_yinc[0];
+
+ png_ptr->usr_width = (png_ptr->width + png_pass_inc[0] - 1 -
+ png_pass_start[0]) / png_pass_inc[0];
+ }
+
+ else
+ {
+ png_ptr->num_rows = png_ptr->height;
+ png_ptr->usr_width = png_ptr->width;
+ }
+ }
+
+ else
+#endif
+ {
+ png_ptr->num_rows = png_ptr->height;
+ png_ptr->usr_width = png_ptr->width;
+ }
+}
+
+/* Internal use only. Called when finished processing a row of data. */
+void /* PRIVATE */
+png_write_finish_row(png_structrp png_ptr)
+{
+#ifdef PNG_WRITE_INTERLACING_SUPPORTED
+ /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
+
+ /* Start of interlace block */
+ static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
+
+ /* Offset to next interlace block */
+ static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
+
+ /* Start of interlace block in the y direction */
+ static PNG_CONST png_byte png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
+
+ /* Offset to next interlace block in the y direction */
+ static PNG_CONST png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
+#endif
+
+ png_debug(1, "in png_write_finish_row");
+
+ /* Next row */
+ png_ptr->row_number++;
+
+ /* See if we are done */
+ if (png_ptr->row_number < png_ptr->num_rows)
+ return;
+
+#ifdef PNG_WRITE_INTERLACING_SUPPORTED
+ /* If interlaced, go to next pass */
+ if (png_ptr->interlaced != 0)
+ {
+ png_ptr->row_number = 0;
+ if ((png_ptr->transformations & PNG_INTERLACE) != 0)
+ {
+ png_ptr->pass++;
+ }
+
+ else
+ {
+ /* Loop until we find a non-zero width or height pass */
+ do
+ {
+ png_ptr->pass++;
+
+ if (png_ptr->pass >= 7)
+ break;
+
+ png_ptr->usr_width = (png_ptr->width +
+ png_pass_inc[png_ptr->pass] - 1 -
+ png_pass_start[png_ptr->pass]) /
+ png_pass_inc[png_ptr->pass];
+
+ png_ptr->num_rows = (png_ptr->height +
+ png_pass_yinc[png_ptr->pass] - 1 -
+ png_pass_ystart[png_ptr->pass]) /
+ png_pass_yinc[png_ptr->pass];
+
+ if ((png_ptr->transformations & PNG_INTERLACE) != 0)
+ break;
+
+ } while (png_ptr->usr_width == 0 || png_ptr->num_rows == 0);
+
+ }
+
+ /* Reset the row above the image for the next pass */
+ if (png_ptr->pass < 7)
+ {
+ if (png_ptr->prev_row != NULL)
+ memset(png_ptr->prev_row, 0,
+ (png_size_t)(PNG_ROWBYTES(png_ptr->usr_channels*
+ png_ptr->usr_bit_depth, png_ptr->width)) + 1);
+
+ return;
+ }
+ }
+#endif
+
+ /* If we get here, we've just written the last row, so we need
+ to flush the compressor */
+ png_compress_IDAT(png_ptr, NULL, 0, Z_FINISH);
+}
+
+#ifdef PNG_WRITE_INTERLACING_SUPPORTED
+/* Pick out the correct pixels for the interlace pass.
+ * The basic idea here is to go through the row with a source
+ * pointer and a destination pointer (sp and dp), and copy the
+ * correct pixels for the pass. As the row gets compacted,
+ * sp will always be >= dp, so we should never overwrite anything.
+ * See the default: case for the easiest code to understand.
+ */
+void /* PRIVATE */
+png_do_write_interlace(png_row_infop row_info, png_bytep row, int pass)
+{
+ /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
+
+ /* Start of interlace block */
+ static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
+
+ /* Offset to next interlace block */
+ static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
+
+ png_debug(1, "in png_do_write_interlace");
+
+ /* We don't have to do anything on the last pass (6) */
+ if (pass < 6)
+ {
+ /* Each pixel depth is handled separately */
+ switch (row_info->pixel_depth)
+ {
+ case 1:
+ {
+ png_bytep sp;
+ png_bytep dp;
+ unsigned int shift;
+ int d;
+ int value;
+ png_uint_32 i;
+ png_uint_32 row_width = row_info->width;
+
+ dp = row;
+ d = 0;
+ shift = 7;
+
+ for (i = png_pass_start[pass]; i < row_width;
+ i += png_pass_inc[pass])
+ {
+ sp = row + (png_size_t)(i >> 3);
+ value = (int)(*sp >> (7 - (int)(i & 0x07))) & 0x01;
+ d |= (value << shift);
+
+ if (shift == 0)
+ {
+ shift = 7;
+ *dp++ = (png_byte)d;
+ d = 0;
+ }
+
+ else
+ shift--;
+
+ }
+ if (shift != 7)
+ *dp = (png_byte)d;
+
+ break;
+ }
+
+ case 2:
+ {
+ png_bytep sp;
+ png_bytep dp;
+ unsigned int shift;
+ int d;
+ int value;
+ png_uint_32 i;
+ png_uint_32 row_width = row_info->width;
+
+ dp = row;
+ shift = 6;
+ d = 0;
+
+ for (i = png_pass_start[pass]; i < row_width;
+ i += png_pass_inc[pass])
+ {
+ sp = row + (png_size_t)(i >> 2);
+ value = (*sp >> ((3 - (int)(i & 0x03)) << 1)) & 0x03;
+ d |= (value << shift);
+
+ if (shift == 0)
+ {
+ shift = 6;
+ *dp++ = (png_byte)d;
+ d = 0;
+ }
+
+ else
+ shift -= 2;
+ }
+ if (shift != 6)
+ *dp = (png_byte)d;
+
+ break;
+ }
+
+ case 4:
+ {
+ png_bytep sp;
+ png_bytep dp;
+ unsigned int shift;
+ int d;
+ int value;
+ png_uint_32 i;
+ png_uint_32 row_width = row_info->width;
+
+ dp = row;
+ shift = 4;
+ d = 0;
+ for (i = png_pass_start[pass]; i < row_width;
+ i += png_pass_inc[pass])
+ {
+ sp = row + (png_size_t)(i >> 1);
+ value = (*sp >> ((1 - (int)(i & 0x01)) << 2)) & 0x0f;
+ d |= (value << shift);
+
+ if (shift == 0)
+ {
+ shift = 4;
+ *dp++ = (png_byte)d;
+ d = 0;
+ }
+
+ else
+ shift -= 4;
+ }
+ if (shift != 4)
+ *dp = (png_byte)d;
+
+ break;
+ }
+
+ default:
+ {
+ png_bytep sp;
+ png_bytep dp;
+ png_uint_32 i;
+ png_uint_32 row_width = row_info->width;
+ png_size_t pixel_bytes;
+
+ /* Start at the beginning */
+ dp = row;
+
+ /* Find out how many bytes each pixel takes up */
+ pixel_bytes = (row_info->pixel_depth >> 3);
+
+ /* Loop through the row, only looking at the pixels that matter */
+ for (i = png_pass_start[pass]; i < row_width;
+ i += png_pass_inc[pass])
+ {
+ /* Find out where the original pixel is */
+ sp = row + (png_size_t)i * pixel_bytes;
+
+ /* Move the pixel */
+ if (dp != sp)
+ memcpy(dp, sp, pixel_bytes);
+
+ /* Next pixel */
+ dp += pixel_bytes;
+ }
+ break;
+ }
+ }
+ /* Set new row width */
+ row_info->width = (row_info->width +
+ png_pass_inc[pass] - 1 -
+ png_pass_start[pass]) /
+ png_pass_inc[pass];
+
+ row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth,
+ row_info->width);
+ }
+}
+#endif
+
+
+/* This filters the row, chooses which filter to use, if it has not already
+ * been specified by the application, and then writes the row out with the
+ * chosen filter.
+ */
+static void /* PRIVATE */
+png_write_filtered_row(png_structrp png_ptr, png_bytep filtered_row,
+ png_size_t row_bytes);
+
+#ifdef PNG_WRITE_FILTER_SUPPORTED
+static png_size_t /* PRIVATE */
+png_setup_sub_row(png_structrp png_ptr, const png_uint_32 bpp,
+ const png_size_t row_bytes, const png_size_t lmins)
+{
+ png_bytep rp, dp, lp;
+ png_size_t i;
+ png_size_t sum = 0;
+ int v;
+
+ png_ptr->try_row[0] = PNG_FILTER_VALUE_SUB;
+
+ for (i = 0, rp = png_ptr->row_buf + 1, dp = png_ptr->try_row + 1; i < bpp;
+ i++, rp++, dp++)
+ {
+ v = *dp = *rp;
+ sum += (v < 128) ? v : 256 - v;
+ }
+
+ for (lp = png_ptr->row_buf + 1; i < row_bytes;
+ i++, rp++, lp++, dp++)
+ {
+ v = *dp = (png_byte)(((int)*rp - (int)*lp) & 0xff);
+ sum += (v < 128) ? v : 256 - v;
+
+ if (sum > lmins) /* We are already worse, don't continue. */
+ break;
+ }
+
+ return (sum);
+}
+
+static png_size_t /* PRIVATE */
+png_setup_up_row(png_structrp png_ptr, const png_size_t row_bytes,
+ const png_size_t lmins)
+{
+ png_bytep rp, dp, pp;
+ png_size_t i;
+ png_size_t sum = 0;
+ int v;
+
+ png_ptr->try_row[0] = PNG_FILTER_VALUE_UP;
+
+ for (i = 0, rp = png_ptr->row_buf + 1, dp = png_ptr->try_row + 1,
+ pp = png_ptr->prev_row + 1; i < row_bytes;
+ i++, rp++, pp++, dp++)
+ {
+ v = *dp = (png_byte)(((int)*rp - (int)*pp) & 0xff);
+ sum += (v < 128) ? v : 256 - v;
+
+ if (sum > lmins) /* We are already worse, don't continue. */
+ break;
+ }
+
+ return (sum);
+}
+
+static png_size_t /* PRIVATE */
+png_setup_avg_row(png_structrp png_ptr, const png_uint_32 bpp,
+ const png_size_t row_bytes, const png_size_t lmins)
+{
+ png_bytep rp, dp, pp, lp;
+ png_uint_32 i;
+ png_size_t sum = 0;
+ int v;
+
+ png_ptr->try_row[0] = PNG_FILTER_VALUE_AVG;
+
+ for (i = 0, rp = png_ptr->row_buf + 1, dp = png_ptr->try_row + 1,
+ pp = png_ptr->prev_row + 1; i < bpp; i++)
+ {
+ v = *dp++ = (png_byte)(((int)*rp++ - ((int)*pp++ / 2)) & 0xff);
+
+ sum += (v < 128) ? v : 256 - v;
+ }
+
+ for (lp = png_ptr->row_buf + 1; i < row_bytes; i++)
+ {
+ v = *dp++ = (png_byte)(((int)*rp++ - (((int)*pp++ + (int)*lp++) / 2))
+ & 0xff);
+
+ sum += (v < 128) ? v : 256 - v;
+
+ if (sum > lmins) /* We are already worse, don't continue. */
+ break;
+ }
+
+ return (sum);
+}
+
+static png_size_t /* PRIVATE */
+png_setup_paeth_row(png_structrp png_ptr, const png_uint_32 bpp,
+ const png_size_t row_bytes, const png_size_t lmins)
+{
+ png_bytep rp, dp, pp, cp, lp;
+ png_size_t i;
+ png_size_t sum = 0;
+ int v;
+
+ png_ptr->try_row[0] = PNG_FILTER_VALUE_PAETH;
+
+ for (i = 0, rp = png_ptr->row_buf + 1, dp = png_ptr->try_row + 1,
+ pp = png_ptr->prev_row + 1; i < bpp; i++)
+ {
+ v = *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff);
+
+ sum += (v < 128) ? v : 256 - v;
+ }
+
+ for (lp = png_ptr->row_buf + 1, cp = png_ptr->prev_row + 1; i < row_bytes;
+ i++)
+ {
+ int a, b, c, pa, pb, pc, p;
+
+ b = *pp++;
+ c = *cp++;
+ a = *lp++;
+
+ p = b - c;
+ pc = a - c;
+
+#ifdef PNG_USE_ABS
+ pa = abs(p);
+ pb = abs(pc);
+ pc = abs(p + pc);
+#else
+ pa = p < 0 ? -p : p;
+ pb = pc < 0 ? -pc : pc;
+ pc = (p + pc) < 0 ? -(p + pc) : p + pc;
+#endif
+
+ p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c;
+
+ v = *dp++ = (png_byte)(((int)*rp++ - p) & 0xff);
+
+ sum += (v < 128) ? v : 256 - v;
+
+ if (sum > lmins) /* We are already worse, don't continue. */
+ break;
+ }
+
+ return (sum);
+}
+#endif /* WRITE_FILTER */
+
+void /* PRIVATE */
+png_write_find_filter(png_structrp png_ptr, png_row_infop row_info)
+{
+#ifndef PNG_WRITE_FILTER_SUPPORTED
+ png_write_filtered_row(png_ptr, png_ptr->row_buf, row_info->rowbytes+1);
+#else
+ png_byte filter_to_do = png_ptr->do_filter;
+ png_bytep row_buf;
+ png_bytep best_row;
+ png_uint_32 bpp;
+ png_size_t mins;
+ png_size_t row_bytes = row_info->rowbytes;
+
+ png_debug(1, "in png_write_find_filter");
+
+ /* Find out how many bytes offset each pixel is */
+ bpp = (row_info->pixel_depth + 7) >> 3;
+
+ row_buf = png_ptr->row_buf;
+ mins = PNG_SIZE_MAX - 256/* so we can detect potential overflow of the
+ running sum */;
+
+ /* The prediction method we use is to find which method provides the
+ * smallest value when summing the absolute values of the distances
+ * from zero, using anything >= 128 as negative numbers. This is known
+ * as the "minimum sum of absolute differences" heuristic. Other
+ * heuristics are the "weighted minimum sum of absolute differences"
+ * (experimental and can in theory improve compression), and the "zlib
+ * predictive" method (not implemented yet), which does test compressions
+ * of lines using different filter methods, and then chooses the
+ * (series of) filter(s) that give minimum compressed data size (VERY
+ * computationally expensive).
+ *
+ * GRR 980525: consider also
+ *
+ * (1) minimum sum of absolute differences from running average (i.e.,
+ * keep running sum of non-absolute differences & count of bytes)
+ * [track dispersion, too? restart average if dispersion too large?]
+ *
+ * (1b) minimum sum of absolute differences from sliding average, probably
+ * with window size <= deflate window (usually 32K)
+ *
+ * (2) minimum sum of squared differences from zero or running average
+ * (i.e., ~ root-mean-square approach)
+ */
+
+
+ /* We don't need to test the 'no filter' case if this is the only filter
+ * that has been chosen, as it doesn't actually do anything to the data.
+ */
+ best_row = png_ptr->row_buf;
+
+
+ if ((filter_to_do & PNG_FILTER_NONE) != 0 && filter_to_do != PNG_FILTER_NONE)
+ {
+ png_bytep rp;
+ png_size_t sum = 0;
+ png_size_t i;
+ int v;
+
+ if (PNG_SIZE_MAX/128 <= row_bytes)
+ {
+ for (i = 0, rp = row_buf + 1; i < row_bytes; i++, rp++)
+ {
+ /* Check for overflow */
+ if (sum > PNG_SIZE_MAX/128 - 256)
+ break;
+
+ v = *rp;
+ sum += (v < 128) ? v : 256 - v;
+ }
+ }
+ else /* Overflow is not possible */
+ {
+ for (i = 0, rp = row_buf + 1; i < row_bytes; i++, rp++)
+ {
+ v = *rp;
+ sum += (v < 128) ? v : 256 - v;
+ }
+ }
+
+ mins = sum;
+ }
+
+ /* Sub filter */
+ if (filter_to_do == PNG_FILTER_SUB)
+ /* It's the only filter so no testing is needed */
+ {
+ (void) png_setup_sub_row(png_ptr, bpp, row_bytes, mins);
+ best_row = png_ptr->try_row;
+ }
+
+ else if ((filter_to_do & PNG_FILTER_SUB) != 0)
+ {
+ png_size_t sum;
+ png_size_t lmins = mins;
+
+ sum = png_setup_sub_row(png_ptr, bpp, row_bytes, lmins);
+
+ if (sum < mins)
+ {
+ mins = sum;
+ best_row = png_ptr->try_row;
+ if (png_ptr->tst_row != NULL)
+ {
+ png_ptr->try_row = png_ptr->tst_row;
+ png_ptr->tst_row = best_row;
+ }
+ }
+ }
+
+ /* Up filter */
+ if (filter_to_do == PNG_FILTER_UP)
+ {
+ (void) png_setup_up_row(png_ptr, row_bytes, mins);
+ best_row = png_ptr->try_row;
+ }
+
+ else if ((filter_to_do & PNG_FILTER_UP) != 0)
+ {
+ png_size_t sum;
+ png_size_t lmins = mins;
+
+ sum = png_setup_up_row(png_ptr, row_bytes, lmins);
+
+ if (sum < mins)
+ {
+ mins = sum;
+ best_row = png_ptr->try_row;
+ if (png_ptr->tst_row != NULL)
+ {
+ png_ptr->try_row = png_ptr->tst_row;
+ png_ptr->tst_row = best_row;
+ }
+ }
+ }
+
+ /* Avg filter */
+ if (filter_to_do == PNG_FILTER_AVG)
+ {
+ (void) png_setup_avg_row(png_ptr, bpp, row_bytes, mins);
+ best_row = png_ptr->try_row;
+ }
+
+ else if ((filter_to_do & PNG_FILTER_AVG) != 0)
+ {
+ png_size_t sum;
+ png_size_t lmins = mins;
+
+ sum= png_setup_avg_row(png_ptr, bpp, row_bytes, lmins);
+
+ if (sum < mins)
+ {
+ mins = sum;
+ best_row = png_ptr->try_row;
+ if (png_ptr->tst_row != NULL)
+ {
+ png_ptr->try_row = png_ptr->tst_row;
+ png_ptr->tst_row = best_row;
+ }
+ }
+ }
+
+ /* Paeth filter */
+ if ((filter_to_do == PNG_FILTER_PAETH) != 0)
+ {
+ (void) png_setup_paeth_row(png_ptr, bpp, row_bytes, mins);
+ best_row = png_ptr->try_row;
+ }
+
+ else if ((filter_to_do & PNG_FILTER_PAETH) != 0)
+ {
+ png_size_t sum;
+ png_size_t lmins = mins;
+
+ sum = png_setup_paeth_row(png_ptr, bpp, row_bytes, lmins);
+
+ if (sum < mins)
+ {
+ best_row = png_ptr->try_row;
+ if (png_ptr->tst_row != NULL)
+ {
+ png_ptr->try_row = png_ptr->tst_row;
+ png_ptr->tst_row = best_row;
+ }
+ }
+ }
+
+ /* Do the actual writing of the filtered row data from the chosen filter. */
+ png_write_filtered_row(png_ptr, best_row, row_info->rowbytes+1);
+
+#endif /* WRITE_FILTER */
+}
+
+
+/* Do the actual writing of a previously filtered row. */
+static void
+png_write_filtered_row(png_structrp png_ptr, png_bytep filtered_row,
+ png_size_t full_row_length/*includes filter byte*/)
+{
+ png_debug(1, "in png_write_filtered_row");
+
+ png_debug1(2, "filter = %d", filtered_row[0]);
+
+ png_compress_IDAT(png_ptr, filtered_row, full_row_length, Z_NO_FLUSH);
+
+#ifdef PNG_WRITE_FILTER_SUPPORTED
+ /* Swap the current and previous rows */
+ if (png_ptr->prev_row != NULL)
+ {
+ png_bytep tptr;
+
+ tptr = png_ptr->prev_row;
+ png_ptr->prev_row = png_ptr->row_buf;
+ png_ptr->row_buf = tptr;
+ }
+#endif /* WRITE_FILTER */
+
+ /* Finish row - updates counters and flushes zlib if last row */
+ png_write_finish_row(png_ptr);
+
+#ifdef PNG_WRITE_FLUSH_SUPPORTED
+ png_ptr->flush_rows++;
+
+ if (png_ptr->flush_dist > 0 &&
+ png_ptr->flush_rows >= png_ptr->flush_dist)
+ {
+ png_write_flush(png_ptr);
+ }
+#endif /* WRITE_FLUSH */
+}
+#endif /* WRITE */
diff --git a/third_party/third_party.gyp b/third_party/third_party.gyp
index 54b6aa3..f653760 100644
--- a/third_party/third_party.gyp
+++ b/third_party/third_party.gyp
@@ -269,22 +269,28 @@
'target_name': 'fx_lpng',
'type': 'static_library',
'sources': [
- 'lpng_v163/png.h',
- 'lpng_v163/png.c',
- 'lpng_v163/pngerror.c',
- 'lpng_v163/pngget.c',
- 'lpng_v163/pngmem.c',
- 'lpng_v163/pngpread.c',
- 'lpng_v163/pngread.c',
- 'lpng_v163/pngrio.c',
- 'lpng_v163/pngrtran.c',
- 'lpng_v163/pngrutil.c',
- 'lpng_v163/pngset.c',
- 'lpng_v163/pngtrans.c',
- 'lpng_v163/pngwio.c',
- 'lpng_v163/pngwrite.c',
- 'lpng_v163/pngwtran.c',
- 'lpng_v163/pngwutil.c',
+ 'libpng/png.c',
+ 'libpng/png.h',
+ 'libpng/pngconf.h',
+ 'libpng/pngdebug.h',
+ 'libpng/pngerror.c',
+ 'libpng/pngget.c',
+ 'libpng/pnginfo.h',
+ 'libpng/pnglibconf.h',
+ 'libpng/pngmem.c',
+ 'libpng/pngpread.c',
+ 'libpng/pngpriv.h',
+ 'libpng/pngread.c',
+ 'libpng/pngrio.c',
+ 'libpng/pngrtran.c',
+ 'libpng/pngrutil.c',
+ 'libpng/pngset.c',
+ 'libpng/pngstruct.h',
+ 'libpng/pngtrans.c',
+ 'libpng/pngwio.c',
+ 'libpng/pngwrite.c',
+ 'libpng/pngwtran.c',
+ 'libpng/pngwutil.c',
],
},
{
