struct png_struct_def { #ifdef PNG_SETJMP_SUPPORTED jmp_buf jmpbuf; /* used in png_error */ #endif png_error_ptr error_fn; /* function for printing errors and aborting */ png_error_ptr warning_fn; /* function for printing warnings */ 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*/ #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) png_user_transform_ptr read_user_transform_fn; /* user read transform */ #endif #if defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) png_user_transform_ptr write_user_transform_fn; /* user write transform */ #endif #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 #if defined(PNG_READ_USER_CHUNKS_SUPPORTED) png_voidp user_chunk_ptr; png_user_chunk_ptr read_user_chunk_fn; /* user read chunk handler */ #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 */ png_size_t zbuf_size; /* size of zbuf */ 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 */ 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_uint_32 rowbytes; /* size of row in bytes */ png_uint_32 irowbytes; /* size of current interlaced 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_bytep prev_row; /* buffer to save previous (unfiltered) row */ png_bytep row_buf; /* buffer to save current (unfiltered) row */ 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_row_info row_info; /* used for transformation routines */ 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 */ png_uint_16 num_trans; /* number of transparency values */ png_byte chunk_name[5]; /* null-terminated name of current chunk */ 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 */ 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 */ png_byte sig_bytes; /* magic bytes read/written from start of file */ #if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED) png_uint_16 filler; /* filler bytes for pixel expansion */ #endif #if defined(PNG_READ_bKGD_SUPPORTED) png_byte background_gamma_type; #ifdef PNG_FLOATING_POINT_SUPPORTED float background_gamma; #endif png_color_16 background; /* background color in screen gamma space */ # if defined(PNG_READ_GAMMA_SUPPORTED) png_color_16 background_1; /* background normalized to gamma 1.0 */ # endif /* PNG_READ_GAMMA && PNG_READ_bKGD_SUPPORTED */ #endif /* PNG_READ_bKGD_SUPPORTED */ #if defined(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 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) int gamma_shift; /* number of "insignificant" bits 16-bit gamma */ #ifdef PNG_FLOATING_POINT_SUPPORTED float gamma; /* file gamma value */ float screen_gamma; /* screen gamma value (display_exponent) */ #endif #endif #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) png_bytep gamma_table; /* gamma table for 8-bit depth files */ 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_table; /* gamma table for 16-bit depth files */ 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 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined (PNG_READ_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_READ_tRNS_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) \ || defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) png_bytep trans; /* transparency values for paletted files */ png_color_16 trans_values; /* transparency values 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 each 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 */ # if defined(PNG_READ_TEXT_SUPPORTED) png_size_t current_text_size; /* current size of text input data */ png_size_t current_text_left; /* how much text left to read in input */ png_charp current_text; /* current text chunk buffer */ png_charp current_text_ptr; /* current location in current_text */ # endif /* PNG_PROGRESSIVE_READ_SUPPORTED && PNG_READ_TEXT_SUPPORTED */ #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 #if defined(PNG_READ_DITHER_SUPPORTED) png_bytep palette_lookup; /* lookup table for dithering */ png_bytep dither_index; /* index translation for palette files */ #endif #if defined(PNG_READ_DITHER_SUPPORTED) || defined(PNG_READ_hIST_SUPPORTED) png_uint_16p hist; /* histogram */ #endif #if defined(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 defined(PNG_TIME_RFC1123_SUPPORTED) png_charp time_buffer; /* String to hold RFC 1123 time text */ #endif #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 #if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED) png_byte rgb_to_gray_status; png_uint_16 rgb_to_gray_red_coeff; png_uint_16 rgb_to_gray_green_coeff; png_uint_16 rgb_to_gray_blue_coeff; #endif #if defined(PNG_READ_EMPTY_PLTE_SUPPORTED) || \ defined(PNG_WRITE_EMPTY_PLTE_SUPPORTED) png_byte empty_plte_permitted; #endif #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED) int num_chunk_list; png_bytep chunk_list; #endif #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) png_fixed_point int_gamma; #endif png_uint_32 free_me; /* flags items libpng is responsible for freeing */ };