| |
| /* pngstruct.h - header file for PNG reference library |
| * |
| * Copyright (c) 2018-2019 Cosmin Truta |
| * Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson |
| * Copyright (c) 1996-1997 Andreas Dilger |
| * 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 "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 |
| * maximum for size_t. The value can be overridden 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 */ |
| 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 |
| 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_ in png.h ) */ |
| 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 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 transformation */ |
| #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 */ |
| size_t save_buffer_size; /* amount of data now in save_buffer */ |
| size_t save_buffer_max; /* total size of save_buffer */ |
| size_t buffer_size; /* total amount of available input data */ |
| 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_uint_32 options; /* On/off state (up to 16 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-1.6.36 */ |
| #if defined(PNG_READ_EXPAND_SUPPORTED) && \ |
| defined(PNG_ARM_NEON_IMPLEMENTATION) |
| png_bytep riffled_palette; /* buffer for accelerated palette expansion */ |
| #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 */ |
| 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 */ |
