|  |  | 
|  | /* pngstruct.h - header file for PNG reference library | 
|  | * | 
|  | * Copyright (c) 1998-2012 Glenn Randers-Pehrson | 
|  | * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) | 
|  | * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) | 
|  | * | 
|  | * Last changed in libpng 1.6.0 [(PENDING RELEASE)] | 
|  | * | 
|  | * 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 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 */ | 
|  |  | 
|  | 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 | 
|  | png_uint_16 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 */ | 
|  | #if PNG_LIBPNG_VER < 10600 | 
|  | png_byte io_chunk_string[5]; | 
|  | /* string name of chunk */ | 
|  | #endif | 
|  |  | 
|  | #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 | 
|  |  | 
|  | #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 | 
|  |  | 
|  | #if PNG_LIBPNG_VER < 10700 | 
|  | #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; | 
|  | png_user_chunk_ptr read_user_chunk_fn; /* user read chunk handler */ | 
|  | #endif | 
|  |  | 
|  | #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED | 
|  | unsigned 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 | 
|  |  | 
|  | /* 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 | 
|  | /* Temporary storage for unknown chunk that the library doesn't recognize, | 
|  | * used while reading the chunk. | 
|  | */ | 
|  | #ifdef PNG_READ_SUPPORTED | 
|  | png_unknown_chunk unknown_chunk; | 
|  | #endif | 
|  | #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 */ |