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pngstruct.h
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pngstruct.h
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/* pngstruct.h - header file for PNG reference library
*
* 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 1.5.9 [March 29, 2012]
*
* 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.
*/
#include "zlib.h"
struct png_struct_def
{
#ifdef PNG_SETJMP_SUPPORTED
jmp_buf longjmp_buffer; /* used in png_error */
png_longjmp_ptr longjmp_fn;/* setjmp non-local goto function. */
#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 */
z_stream zstream; /* pointer to decompression structure (below) */
png_bytep zbuf; /* buffer for zlib */
uInt zbuf_size; /* size of zbuf (typically 65536) */
#ifdef PNG_WRITE_SUPPORTED
/* Added in 1.5.4: state to keep track of whether the zstream has been
* initialized and if so whether it is for IDAT or some other chunk.
*/
#define PNG_ZLIB_UNINITIALIZED 0
#define PNG_ZLIB_FOR_IDAT 1
#define PNG_ZLIB_FOR_TEXT 2 /* anything other than IDAT */
#define PNG_ZLIB_USE_MASK 3 /* bottom two bits */
#define PNG_ZLIB_IN_USE 4 /* a flag value */
png_uint_32 zlib_state; /* State of zlib initialization */
/* End of material added at libpng 1.5.4 */
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 */
#if defined(PNG_WRITE_COMPRESSED_TEXT_SUPPORTED) || \
defined(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 */
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
*/
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 */
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 */
png_byte usr_channels; /* channels at start of write: write only */
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 */
png_byte io_chunk_string[5];
/* string name of chunk */
#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 gamma; /* file gamma value */
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
#if defined(PNG_READ_QUANTIZE_SUPPORTED) || defined(PNG_hIST_SUPPORTED)
png_uint_16p hist; /* histogram */
#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
#ifdef PNG_TIME_RFC1123_SUPPORTED
char time_buffer[29]; /* String to hold RFC 1123 time text */
#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;
png_user_chunk_ptr read_user_chunk_fn; /* user read chunk handler */
#endif
#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
int num_chunk_list;
png_bytep chunk_list;
#endif
#ifdef PNG_READ_sRGB_SUPPORTED
/* Added in 1.5.5 to record an sRGB chunk in the png. */
png_byte is_sRGB;
#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
#ifdef PNG_APNG_SUPPORTED
png_uint_32 apng_flags;
png_uint_32 next_seq_num; /* next fcTL/fdAT chunk sequence number */
png_uint_32 first_frame_width;
png_uint_32 first_frame_height;
#ifdef PNG_READ_APNG_SUPPORTED
png_uint_32 num_frames_read; /* incremented after all image data of */
/* a frame is read */
#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
png_progressive_frame_ptr frame_info_fn; /* frame info read callback */
png_progressive_frame_ptr frame_end_fn; /* frame data read callback */
#endif
#endif
#ifdef PNG_WRITE_APNG_SUPPORTED
png_uint_32 num_frames_to_write;
png_uint_32 num_frames_written;
#endif
#endif /* PNG_APNG_SUPPORTED */
/* 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_UNKNOWN_CHUNKS_SUPPORTED
/* Storage for unknown chunk that the library doesn't recognize. */
png_unknown_chunk unknown_chunk;
#endif
/* New member added in libpng-1.2.26 */
png_size_t old_big_row_buf_size;
/* New member added in libpng-1.2.30 */
png_charp chunkdata; /* buffer for reading chunk data */
#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;
void (*read_filter[PNG_FILTER_VALUE_LAST-1])(png_row_infop row_info,
png_bytep row, png_const_bytep prev_row);
};
#endif /* PNGSTRUCT_H */