1 2 /* pngstruct.h - header file for PNG reference library 3 * 4 * Copyright (c) 1998-2012 Glenn Randers-Pehrson 5 * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) 6 * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) 7 * 8 * Last changed in libpng 1.5.9 [February 18, 2012] 9 * 10 * This code is released under the libpng license. 11 * For conditions of distribution and use, see the disclaimer 12 * and license in png.h 13 */ 14 15 /* The structure that holds the information to read and write PNG files. 16 * The only people who need to care about what is inside of this are the 17 * people who will be modifying the library for their own special needs. 18 * It should NOT be accessed directly by an application. 19 */ 20 21 #ifndef PNGSTRUCT_H 22 #define PNGSTRUCT_H 23 /* zlib.h defines the structure z_stream, an instance of which is included 24 * in this structure and is required for decompressing the LZ compressed 25 * data in PNG files. 26 */ 27 #include "zlib.h" 28 29 struct png_struct_def 30 { 31 #ifdef PNG_SETJMP_SUPPORTED 32 jmp_buf longjmp_buffer; /* used in png_error */ 33 png_longjmp_ptr longjmp_fn;/* setjmp non-local goto function. */ 34 #endif 35 png_error_ptr error_fn; /* function for printing errors and aborting */ 36 #ifdef PNG_WARNINGS_SUPPORTED 37 png_error_ptr warning_fn; /* function for printing warnings */ 38 #endif 39 png_voidp error_ptr; /* user supplied struct for error functions */ 40 png_rw_ptr write_data_fn; /* function for writing output data */ 41 png_rw_ptr read_data_fn; /* function for reading input data */ 42 png_voidp io_ptr; /* ptr to application struct for I/O functions */ 43 44 #ifdef PNG_READ_USER_TRANSFORM_SUPPORTED 45 png_user_transform_ptr read_user_transform_fn; /* user read transform */ 46 #endif 47 48 #ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED 49 png_user_transform_ptr write_user_transform_fn; /* user write transform */ 50 #endif 51 52 /* These were added in libpng-1.0.2 */ 53 #ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED 54 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \ 55 defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) 56 png_voidp user_transform_ptr; /* user supplied struct for user transform */ 57 png_byte user_transform_depth; /* bit depth of user transformed pixels */ 58 png_byte user_transform_channels; /* channels in user transformed pixels */ 59 #endif 60 #endif 61 62 png_uint_32 mode; /* tells us where we are in the PNG file */ 63 png_uint_32 flags; /* flags indicating various things to libpng */ 64 png_uint_32 transformations; /* which transformations to perform */ 65 66 z_stream zstream; /* pointer to decompression structure (below) */ 67 png_bytep zbuf; /* buffer for zlib */ 68 uInt zbuf_size; /* size of zbuf (typically 65536) */ 69 #ifdef PNG_WRITE_SUPPORTED 70 71 /* Added in 1.5.4: state to keep track of whether the zstream has been 72 * initialized and if so whether it is for IDAT or some other chunk. 73 */ 74 #define PNG_ZLIB_UNINITIALIZED 0 75 #define PNG_ZLIB_FOR_IDAT 1 76 #define PNG_ZLIB_FOR_TEXT 2 /* anything other than IDAT */ 77 #define PNG_ZLIB_USE_MASK 3 /* bottom two bits */ 78 #define PNG_ZLIB_IN_USE 4 /* a flag value */ 79 80 png_uint_32 zlib_state; /* State of zlib initialization */ 81 /* End of material added at libpng 1.5.4 */ 82 83 int zlib_level; /* holds zlib compression level */ 84 int zlib_method; /* holds zlib compression method */ 85 int zlib_window_bits; /* holds zlib compression window bits */ 86 int zlib_mem_level; /* holds zlib compression memory level */ 87 int zlib_strategy; /* holds zlib compression strategy */ 88 #endif 89 /* Added at libpng 1.5.4 */ 90 #if defined(PNG_WRITE_COMPRESSED_TEXT_SUPPORTED) || \ 91 defined(PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED) 92 int zlib_text_level; /* holds zlib compression level */ 93 int zlib_text_method; /* holds zlib compression method */ 94 int zlib_text_window_bits; /* holds zlib compression window bits */ 95 int zlib_text_mem_level; /* holds zlib compression memory level */ 96 int zlib_text_strategy; /* holds zlib compression strategy */ 97 #endif 98 /* End of material added at libpng 1.5.4 */ 99 100 png_uint_32 width; /* width of image in pixels */ 101 png_uint_32 height; /* height of image in pixels */ 102 png_uint_32 num_rows; /* number of rows in current pass */ 103 png_uint_32 usr_width; /* width of row at start of write */ 104 png_size_t rowbytes; /* size of row in bytes */ 105 png_uint_32 iwidth; /* width of current interlaced row in pixels */ 106 png_uint_32 row_number; /* current row in interlace pass */ 107 png_uint_32 chunk_name; /* PNG_CHUNK() id of current chunk */ 108 png_bytep prev_row; /* buffer to save previous (unfiltered) row. 109 * This is a pointer into big_prev_row 110 */ 111 png_bytep row_buf; /* buffer to save current (unfiltered) row. 112 * This is a pointer into big_row_buf 113 */ 114 png_bytep sub_row; /* buffer to save "sub" row when filtering */ 115 png_bytep up_row; /* buffer to save "up" row when filtering */ 116 png_bytep avg_row; /* buffer to save "avg" row when filtering */ 117 png_bytep paeth_row; /* buffer to save "Paeth" row when filtering */ 118 png_size_t info_rowbytes; /* Added in 1.5.4: cache of updated row bytes */ 119 120 png_uint_32 idat_size; /* current IDAT size for read */ 121 png_uint_32 crc; /* current chunk CRC value */ 122 png_colorp palette; /* palette from the input file */ 123 png_uint_16 num_palette; /* number of color entries in palette */ 124 125 /* Added at libpng-1.5.10 */ 126 #ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED 127 int num_palette_max; /* maximum palette index found in IDAT */ 128 #endif 129 130 png_uint_16 num_trans; /* number of transparency values */ 131 png_byte compression; /* file compression type (always 0) */ 132 png_byte filter; /* file filter type (always 0) */ 133 png_byte interlaced; /* PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */ 134 png_byte pass; /* current interlace pass (0 - 6) */ 135 png_byte do_filter; /* row filter flags (see PNG_FILTER_ below ) */ 136 png_byte color_type; /* color type of file */ 137 png_byte bit_depth; /* bit depth of file */ 138 png_byte usr_bit_depth; /* bit depth of users row: write only */ 139 png_byte pixel_depth; /* number of bits per pixel */ 140 png_byte channels; /* number of channels in file */ 141 png_byte usr_channels; /* channels at start of write: write only */ 142 png_byte sig_bytes; /* magic bytes read/written from start of file */ 143 png_byte maximum_pixel_depth; 144 /* pixel depth used for the row buffers */ 145 png_byte transformed_pixel_depth; 146 /* pixel depth after read/write transforms */ 147 png_byte io_chunk_string[5]; 148 /* string name of chunk */ 149 150 #if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED) 151 png_uint_16 filler; /* filler bytes for pixel expansion */ 152 #endif 153 154 #if defined(PNG_bKGD_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) ||\ 155 defined(PNG_READ_ALPHA_MODE_SUPPORTED) 156 png_byte background_gamma_type; 157 png_fixed_point background_gamma; 158 png_color_16 background; /* background color in screen gamma space */ 159 #ifdef PNG_READ_GAMMA_SUPPORTED 160 png_color_16 background_1; /* background normalized to gamma 1.0 */ 161 #endif 162 #endif /* PNG_bKGD_SUPPORTED */ 163 164 #ifdef PNG_WRITE_FLUSH_SUPPORTED 165 png_flush_ptr output_flush_fn; /* Function for flushing output */ 166 png_uint_32 flush_dist; /* how many rows apart to flush, 0 - no flush */ 167 png_uint_32 flush_rows; /* number of rows written since last flush */ 168 #endif 169 170 #ifdef PNG_READ_GAMMA_SUPPORTED 171 int gamma_shift; /* number of "insignificant" bits in 16-bit gamma */ 172 png_fixed_point gamma; /* file gamma value */ 173 png_fixed_point screen_gamma; /* screen gamma value (display_exponent) */ 174 175 png_bytep gamma_table; /* gamma table for 8-bit depth files */ 176 png_uint_16pp gamma_16_table; /* gamma table for 16-bit depth files */ 177 #if defined(PNG_READ_BACKGROUND_SUPPORTED) || \ 178 defined(PNG_READ_ALPHA_MODE_SUPPORTED) || \ 179 defined(PNG_READ_RGB_TO_GRAY_SUPPORTED) 180 png_bytep gamma_from_1; /* converts from 1.0 to screen */ 181 png_bytep gamma_to_1; /* converts from file to 1.0 */ 182 png_uint_16pp gamma_16_from_1; /* converts from 1.0 to screen */ 183 png_uint_16pp gamma_16_to_1; /* converts from file to 1.0 */ 184 #endif /* READ_BACKGROUND || READ_ALPHA_MODE || RGB_TO_GRAY */ 185 #endif 186 187 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_sBIT_SUPPORTED) 188 png_color_8 sig_bit; /* significant bits in each available channel */ 189 #endif 190 191 #if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED) 192 png_color_8 shift; /* shift for significant bit tranformation */ 193 #endif 194 195 #if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) \ 196 || defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) 197 png_bytep trans_alpha; /* alpha values for paletted files */ 198 png_color_16 trans_color; /* transparent color for non-paletted files */ 199 #endif 200 201 png_read_status_ptr read_row_fn; /* called after each row is decoded */ 202 png_write_status_ptr write_row_fn; /* called after each row is encoded */ 203 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED 204 png_progressive_info_ptr info_fn; /* called after header data fully read */ 205 png_progressive_row_ptr row_fn; /* called after a prog. row is decoded */ 206 png_progressive_end_ptr end_fn; /* called after image is complete */ 207 png_bytep save_buffer_ptr; /* current location in save_buffer */ 208 png_bytep save_buffer; /* buffer for previously read data */ 209 png_bytep current_buffer_ptr; /* current location in current_buffer */ 210 png_bytep current_buffer; /* buffer for recently used data */ 211 png_uint_32 push_length; /* size of current input chunk */ 212 png_uint_32 skip_length; /* bytes to skip in input data */ 213 png_size_t save_buffer_size; /* amount of data now in save_buffer */ 214 png_size_t save_buffer_max; /* total size of save_buffer */ 215 png_size_t buffer_size; /* total amount of available input data */ 216 png_size_t current_buffer_size; /* amount of data now in current_buffer */ 217 int process_mode; /* what push library is currently doing */ 218 int cur_palette; /* current push library palette index */ 219 220 #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */ 221 222 #if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__) 223 /* For the Borland special 64K segment handler */ 224 png_bytepp offset_table_ptr; 225 png_bytep offset_table; 226 png_uint_16 offset_table_number; 227 png_uint_16 offset_table_count; 228 png_uint_16 offset_table_count_free; 229 #endif 230 231 #ifdef PNG_READ_QUANTIZE_SUPPORTED 232 png_bytep palette_lookup; /* lookup table for quantizing */ 233 png_bytep quantize_index; /* index translation for palette files */ 234 #endif 235 236 #if defined(PNG_READ_QUANTIZE_SUPPORTED) || defined(PNG_hIST_SUPPORTED) 237 png_uint_16p hist; /* histogram */ 238 #endif 239 240 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED 241 png_byte heuristic_method; /* heuristic for row filter selection */ 242 png_byte num_prev_filters; /* number of weights for previous rows */ 243 png_bytep prev_filters; /* filter type(s) of previous row(s) */ 244 png_uint_16p filter_weights; /* weight(s) for previous line(s) */ 245 png_uint_16p inv_filter_weights; /* 1/weight(s) for previous line(s) */ 246 png_uint_16p filter_costs; /* relative filter calculation cost */ 247 png_uint_16p inv_filter_costs; /* 1/relative filter calculation cost */ 248 #endif 249 250 #ifdef PNG_TIME_RFC1123_SUPPORTED 251 /* This is going to be unused in libpng16 and removed from libpng17 */ 252 char time_buffer[29]; /* String to hold RFC 1123 time text */ 253 #endif 254 255 /* New members added in libpng-1.0.6 */ 256 257 png_uint_32 free_me; /* flags items libpng is responsible for freeing */ 258 259 #ifdef PNG_USER_CHUNKS_SUPPORTED 260 png_voidp user_chunk_ptr; 261 png_user_chunk_ptr read_user_chunk_fn; /* user read chunk handler */ 262 #endif 263 264 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED 265 int num_chunk_list; 266 png_bytep chunk_list; 267 #endif 268 269 #ifdef PNG_READ_sRGB_SUPPORTED 270 /* Added in 1.5.5 to record an sRGB chunk in the png. */ 271 png_byte is_sRGB; 272 #endif 273 274 /* New members added in libpng-1.0.3 */ 275 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED 276 png_byte rgb_to_gray_status; 277 /* Added in libpng 1.5.5 to record setting of coefficients: */ 278 png_byte rgb_to_gray_coefficients_set; 279 /* These were changed from png_byte in libpng-1.0.6 */ 280 png_uint_16 rgb_to_gray_red_coeff; 281 png_uint_16 rgb_to_gray_green_coeff; 282 /* deleted in 1.5.5: rgb_to_gray_blue_coeff; */ 283 #endif 284 285 /* New member added in libpng-1.0.4 (renamed in 1.0.9) */ 286 #if defined(PNG_MNG_FEATURES_SUPPORTED) 287 /* Changed from png_byte to png_uint_32 at version 1.2.0 */ 288 png_uint_32 mng_features_permitted; 289 #endif 290 291 /* New member added in libpng-1.0.9, ifdef'ed out in 1.0.12, enabled in 1.2.0 */ 292 #ifdef PNG_MNG_FEATURES_SUPPORTED 293 png_byte filter_type; 294 #endif 295 296 /* New members added in libpng-1.2.0 */ 297 298 /* New members added in libpng-1.0.2 but first enabled by default in 1.2.0 */ 299 #ifdef PNG_USER_MEM_SUPPORTED 300 png_voidp mem_ptr; /* user supplied struct for mem functions */ 301 png_malloc_ptr malloc_fn; /* function for allocating memory */ 302 png_free_ptr free_fn; /* function for freeing memory */ 303 #endif 304 305 /* New member added in libpng-1.0.13 and 1.2.0 */ 306 png_bytep big_row_buf; /* buffer to save current (unfiltered) row */ 307 308 #ifdef PNG_READ_QUANTIZE_SUPPORTED 309 /* The following three members were added at version 1.0.14 and 1.2.4 */ 310 png_bytep quantize_sort; /* working sort array */ 311 png_bytep index_to_palette; /* where the original index currently is 312 in the palette */ 313 png_bytep palette_to_index; /* which original index points to this 314 palette color */ 315 #endif 316 317 /* New members added in libpng-1.0.16 and 1.2.6 */ 318 png_byte compression_type; 319 320 #ifdef PNG_USER_LIMITS_SUPPORTED 321 png_uint_32 user_width_max; 322 png_uint_32 user_height_max; 323 324 /* Added in libpng-1.4.0: Total number of sPLT, text, and unknown 325 * chunks that can be stored (0 means unlimited). 326 */ 327 png_uint_32 user_chunk_cache_max; 328 329 /* Total memory that a zTXt, sPLT, iTXt, iCCP, or unknown chunk 330 * can occupy when decompressed. 0 means unlimited. 331 */ 332 png_alloc_size_t user_chunk_malloc_max; 333 #endif 334 335 /* New member added in libpng-1.0.25 and 1.2.17 */ 336 #ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED 337 /* Storage for unknown chunk that the library doesn't recognize. */ 338 png_unknown_chunk unknown_chunk; 339 #endif 340 341 /* New member added in libpng-1.2.26 */ 342 png_size_t old_big_row_buf_size; 343 344 /* New member added in libpng-1.2.30 */ 345 png_charp chunkdata; /* buffer for reading chunk data */ 346 347 #ifdef PNG_IO_STATE_SUPPORTED 348 /* New member added in libpng-1.4.0 */ 349 png_uint_32 io_state; 350 #endif 351 352 /* New member added in libpng-1.5.6 */ 353 png_bytep big_prev_row; 354 355 void (*read_filter[PNG_FILTER_VALUE_LAST-1])(png_row_infop row_info, 356 png_bytep row, png_const_bytep prev_row); 357 }; 358 #endif /* PNGSTRUCT_H */ 359