/* 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 */ |