1 2 /* pngstruct.h - header file for PNG reference library 3 * 4 * Copyright (c) 1998-2013 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 1.6.1 [March 28, 2013] 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 #ifndef ZLIB_CONST 28 /* We must ensure that zlib uses 'const' in declarations. */ 29 # define ZLIB_CONST 30 #endif 31 #include "third_party/zlib_v128/zlib.h" 32 #ifdef const 33 /* zlib.h sometimes #defines const to nothing, undo this. */ 34 # undef const 35 #endif 36 37 /* zlib.h has mediocre z_const use before 1.2.6, this stuff is for compatibility 38 * with older builds. 39 */ 40 #if ZLIB_VERNUM < 0x1260 41 # define PNGZ_MSG_CAST(s) png_constcast(char*,s) 42 # define PNGZ_INPUT_CAST(b) png_constcast(png_bytep,b) 43 #else 44 # define PNGZ_MSG_CAST(s) (s) 45 # define PNGZ_INPUT_CAST(b) (b) 46 #endif 47 48 /* zlib.h declares a magic type 'uInt' that limits the amount of data that zlib 49 * can handle at once. This type need be no larger than 16 bits (so maximum of 50 * 65535), this define allows us to discover how big it is, but limited by the 51 * maximuum for png_size_t. The value can be overriden in a library build 52 * (pngusr.h, or set it in CPPFLAGS) and it works to set it to a considerably 53 * lower value (e.g. 255 works). A lower value may help memory usage (slightly) 54 * and may even improve performance on some systems (and degrade it on others.) 55 */ 56 #ifndef ZLIB_IO_MAX 57 # define ZLIB_IO_MAX ((uInt)-1) 58 #endif 59 60 #ifdef PNG_WRITE_SUPPORTED 61 /* The type of a compression buffer list used by the write code. */ 62 typedef struct png_compression_buffer 63 { 64 struct png_compression_buffer *next; 65 png_byte output[1]; /* actually zbuf_size */ 66 } png_compression_buffer, *png_compression_bufferp; 67 68 #define PNG_COMPRESSION_BUFFER_SIZE(pp)\ 69 (offsetof(png_compression_buffer, output) + (pp)->zbuffer_size) 70 #endif 71 72 /* Colorspace support; structures used in png_struct, png_info and in internal 73 * functions to hold and communicate information about the color space. 74 * 75 * PNG_COLORSPACE_SUPPORTED is only required if the application will perform 76 * colorspace corrections, otherwise all the colorspace information can be 77 * skipped and the size of libpng can be reduced (significantly) by compiling 78 * out the colorspace support. 79 */ 80 #ifdef PNG_COLORSPACE_SUPPORTED 81 /* The chromaticities of the red, green and blue colorants and the chromaticity 82 * of the corresponding white point (i.e. of rgb(1.0,1.0,1.0)). 83 */ 84 typedef struct png_xy 85 { 86 png_fixed_point redx, redy; 87 png_fixed_point greenx, greeny; 88 png_fixed_point bluex, bluey; 89 png_fixed_point whitex, whitey; 90 } png_xy; 91 92 /* The same data as above but encoded as CIE XYZ values. When this data comes 93 * from chromaticities the sum of the Y values is assumed to be 1.0 94 */ 95 typedef struct png_XYZ 96 { 97 png_fixed_point red_X, red_Y, red_Z; 98 png_fixed_point green_X, green_Y, green_Z; 99 png_fixed_point blue_X, blue_Y, blue_Z; 100 } png_XYZ; 101 #endif /* COLORSPACE */ 102 103 #if defined(PNG_COLORSPACE_SUPPORTED) || defined(PNG_GAMMA_SUPPORTED) 104 /* A colorspace is all the above plus, potentially, profile information, 105 * however at present libpng does not use the profile internally so it is only 106 * stored in the png_info struct (if iCCP is supported.) The rendering intent 107 * is retained here and is checked. 108 * 109 * The file gamma encoding information is also stored here and gamma correction 110 * is done by libpng, whereas color correction must currently be done by the 111 * application. 112 */ 113 typedef struct png_colorspace 114 { 115 #ifdef PNG_GAMMA_SUPPORTED 116 png_fixed_point gamma; /* File gamma */ 117 #endif 118 119 #ifdef PNG_COLORSPACE_SUPPORTED 120 png_xy end_points_xy; /* End points as chromaticities */ 121 png_XYZ end_points_XYZ; /* End points as CIE XYZ colorant values */ 122 png_uint_16 rendering_intent; /* Rendering intent of a profile */ 123 #endif 124 125 /* Flags are always defined to simplify the code. */ 126 png_uint_16 flags; /* As defined below */ 127 } png_colorspace, * PNG_RESTRICT png_colorspacerp; 128 129 typedef const png_colorspace * PNG_RESTRICT png_const_colorspacerp; 130 131 /* General flags for the 'flags' field */ 132 #define PNG_COLORSPACE_HAVE_GAMMA 0x0001 133 #define PNG_COLORSPACE_HAVE_ENDPOINTS 0x0002 134 #define PNG_COLORSPACE_HAVE_INTENT 0x0004 135 #define PNG_COLORSPACE_FROM_gAMA 0x0008 136 #define PNG_COLORSPACE_FROM_cHRM 0x0010 137 #define PNG_COLORSPACE_FROM_sRGB 0x0020 138 #define PNG_COLORSPACE_ENDPOINTS_MATCH_sRGB 0x0040 139 #define PNG_COLORSPACE_MATCHES_sRGB 0x0080 /* exact match on profile */ 140 #define PNG_COLORSPACE_INVALID 0x8000 141 #define PNG_COLORSPACE_CANCEL(flags) (0xffff ^ (flags)) 142 #endif /* COLORSPACE || GAMMA */ 143 144 struct png_struct_def 145 { 146 #ifdef PNG_SETJMP_SUPPORTED 147 jmp_buf jmp_buf_local; /* New name in 1.6.0 for jmp_buf in png_struct */ 148 png_longjmp_ptr longjmp_fn;/* setjmp non-local goto function. */ 149 jmp_buf *jmp_buf_ptr; /* passed to longjmp_fn */ 150 size_t jmp_buf_size; /* size of the above, if allocated */ 151 #endif 152 png_error_ptr error_fn; /* function for printing errors and aborting */ 153 #ifdef PNG_WARNINGS_SUPPORTED 154 png_error_ptr warning_fn; /* function for printing warnings */ 155 #endif 156 png_voidp error_ptr; /* user supplied struct for error functions */ 157 png_rw_ptr write_data_fn; /* function for writing output data */ 158 png_rw_ptr read_data_fn; /* function for reading input data */ 159 png_voidp io_ptr; /* ptr to application struct for I/O functions */ 160 161 #ifdef PNG_READ_USER_TRANSFORM_SUPPORTED 162 png_user_transform_ptr read_user_transform_fn; /* user read transform */ 163 #endif 164 165 #ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED 166 png_user_transform_ptr write_user_transform_fn; /* user write transform */ 167 #endif 168 169 /* These were added in libpng-1.0.2 */ 170 #ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED 171 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \ 172 defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) 173 png_voidp user_transform_ptr; /* user supplied struct for user transform */ 174 png_byte user_transform_depth; /* bit depth of user transformed pixels */ 175 png_byte user_transform_channels; /* channels in user transformed pixels */ 176 #endif 177 #endif 178 179 png_uint_32 mode; /* tells us where we are in the PNG file */ 180 png_uint_32 flags; /* flags indicating various things to libpng */ 181 png_uint_32 transformations; /* which transformations to perform */ 182 183 png_uint_32 zowner; /* ID (chunk type) of zstream owner, 0 if none */ 184 z_stream zstream; /* decompression structure */ 185 186 #ifdef PNG_WRITE_SUPPORTED 187 png_compression_bufferp zbuffer_list; /* Created on demand during write */ 188 uInt zbuffer_size; /* size of the actual buffer */ 189 190 int zlib_level; /* holds zlib compression level */ 191 int zlib_method; /* holds zlib compression method */ 192 int zlib_window_bits; /* holds zlib compression window bits */ 193 int zlib_mem_level; /* holds zlib compression memory level */ 194 int zlib_strategy; /* holds zlib compression strategy */ 195 #endif 196 /* Added at libpng 1.5.4 */ 197 #ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED 198 int zlib_text_level; /* holds zlib compression level */ 199 int zlib_text_method; /* holds zlib compression method */ 200 int zlib_text_window_bits; /* holds zlib compression window bits */ 201 int zlib_text_mem_level; /* holds zlib compression memory level */ 202 int zlib_text_strategy; /* holds zlib compression strategy */ 203 #endif 204 /* End of material added at libpng 1.5.4 */ 205 /* Added at libpng 1.6.0 */ 206 #ifdef PNG_WRITE_SUPPORTED 207 int zlib_set_level; /* Actual values set into the zstream on write */ 208 int zlib_set_method; 209 int zlib_set_window_bits; 210 int zlib_set_mem_level; 211 int zlib_set_strategy; 212 #endif 213 214 png_uint_32 width; /* width of image in pixels */ 215 png_uint_32 height; /* height of image in pixels */ 216 png_uint_32 num_rows; /* number of rows in current pass */ 217 png_uint_32 usr_width; /* width of row at start of write */ 218 png_size_t rowbytes; /* size of row in bytes */ 219 png_uint_32 iwidth; /* width of current interlaced row in pixels */ 220 png_uint_32 row_number; /* current row in interlace pass */ 221 png_uint_32 chunk_name; /* PNG_CHUNK() id of current chunk */ 222 png_bytep prev_row; /* buffer to save previous (unfiltered) row. 223 * This is a pointer into big_prev_row 224 */ 225 png_bytep row_buf; /* buffer to save current (unfiltered) row. 226 * This is a pointer into big_row_buf 227 */ 228 #ifdef PNG_WRITE_SUPPORTED 229 png_bytep sub_row; /* buffer to save "sub" row when filtering */ 230 png_bytep up_row; /* buffer to save "up" row when filtering */ 231 png_bytep avg_row; /* buffer to save "avg" row when filtering */ 232 png_bytep paeth_row; /* buffer to save "Paeth" row when filtering */ 233 #endif 234 png_size_t info_rowbytes; /* Added in 1.5.4: cache of updated row bytes */ 235 236 png_uint_32 idat_size; /* current IDAT size for read */ 237 png_uint_32 crc; /* current chunk CRC value */ 238 png_colorp palette; /* palette from the input file */ 239 png_uint_16 num_palette; /* number of color entries in palette */ 240 241 /* Added at libpng-1.5.10 */ 242 #ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED 243 int num_palette_max; /* maximum palette index found in IDAT */ 244 #endif 245 246 png_uint_16 num_trans; /* number of transparency values */ 247 png_byte compression; /* file compression type (always 0) */ 248 png_byte filter; /* file filter type (always 0) */ 249 png_byte interlaced; /* PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */ 250 png_byte pass; /* current interlace pass (0 - 6) */ 251 png_byte do_filter; /* row filter flags (see PNG_FILTER_ below ) */ 252 png_byte color_type; /* color type of file */ 253 png_byte bit_depth; /* bit depth of file */ 254 png_byte usr_bit_depth; /* bit depth of users row: write only */ 255 png_byte pixel_depth; /* number of bits per pixel */ 256 png_byte channels; /* number of channels in file */ 257 #ifdef PNG_WRITE_SUPPORTED 258 png_byte usr_channels; /* channels at start of write: write only */ 259 #endif 260 png_byte sig_bytes; /* magic bytes read/written from start of file */ 261 png_byte maximum_pixel_depth; 262 /* pixel depth used for the row buffers */ 263 png_byte transformed_pixel_depth; 264 /* pixel depth after read/write transforms */ 265 #if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED) 266 png_uint_16 filler; /* filler bytes for pixel expansion */ 267 #endif 268 269 #if defined(PNG_bKGD_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) ||\ 270 defined(PNG_READ_ALPHA_MODE_SUPPORTED) 271 png_byte background_gamma_type; 272 png_fixed_point background_gamma; 273 png_color_16 background; /* background color in screen gamma space */ 274 #ifdef PNG_READ_GAMMA_SUPPORTED 275 png_color_16 background_1; /* background normalized to gamma 1.0 */ 276 #endif 277 #endif /* PNG_bKGD_SUPPORTED */ 278 279 #ifdef PNG_WRITE_FLUSH_SUPPORTED 280 png_flush_ptr output_flush_fn; /* Function for flushing output */ 281 png_uint_32 flush_dist; /* how many rows apart to flush, 0 - no flush */ 282 png_uint_32 flush_rows; /* number of rows written since last flush */ 283 #endif 284 285 #ifdef PNG_READ_GAMMA_SUPPORTED 286 int gamma_shift; /* number of "insignificant" bits in 16-bit gamma */ 287 png_fixed_point screen_gamma; /* screen gamma value (display_exponent) */ 288 289 png_bytep gamma_table; /* gamma table for 8-bit depth files */ 290 png_uint_16pp gamma_16_table; /* gamma table for 16-bit depth files */ 291 #if defined(PNG_READ_BACKGROUND_SUPPORTED) || \ 292 defined(PNG_READ_ALPHA_MODE_SUPPORTED) || \ 293 defined(PNG_READ_RGB_TO_GRAY_SUPPORTED) 294 png_bytep gamma_from_1; /* converts from 1.0 to screen */ 295 png_bytep gamma_to_1; /* converts from file to 1.0 */ 296 png_uint_16pp gamma_16_from_1; /* converts from 1.0 to screen */ 297 png_uint_16pp gamma_16_to_1; /* converts from file to 1.0 */ 298 #endif /* READ_BACKGROUND || READ_ALPHA_MODE || RGB_TO_GRAY */ 299 #endif 300 301 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_sBIT_SUPPORTED) 302 png_color_8 sig_bit; /* significant bits in each available channel */ 303 #endif 304 305 #if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED) 306 png_color_8 shift; /* shift for significant bit tranformation */ 307 #endif 308 309 #if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) \ 310 || defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) 311 png_bytep trans_alpha; /* alpha values for paletted files */ 312 png_color_16 trans_color; /* transparent color for non-paletted files */ 313 #endif 314 315 png_read_status_ptr read_row_fn; /* called after each row is decoded */ 316 png_write_status_ptr write_row_fn; /* called after each row is encoded */ 317 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED 318 png_progressive_info_ptr info_fn; /* called after header data fully read */ 319 png_progressive_row_ptr row_fn; /* called after a prog. row is decoded */ 320 png_progressive_end_ptr end_fn; /* called after image is complete */ 321 png_bytep save_buffer_ptr; /* current location in save_buffer */ 322 png_bytep save_buffer; /* buffer for previously read data */ 323 png_bytep current_buffer_ptr; /* current location in current_buffer */ 324 png_bytep current_buffer; /* buffer for recently used data */ 325 png_uint_32 push_length; /* size of current input chunk */ 326 png_uint_32 skip_length; /* bytes to skip in input data */ 327 png_size_t save_buffer_size; /* amount of data now in save_buffer */ 328 png_size_t save_buffer_max; /* total size of save_buffer */ 329 png_size_t buffer_size; /* total amount of available input data */ 330 png_size_t current_buffer_size; /* amount of data now in current_buffer */ 331 int process_mode; /* what push library is currently doing */ 332 int cur_palette; /* current push library palette index */ 333 334 #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */ 335 336 #if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__) 337 /* For the Borland special 64K segment handler */ 338 png_bytepp offset_table_ptr; 339 png_bytep offset_table; 340 png_uint_16 offset_table_number; 341 png_uint_16 offset_table_count; 342 png_uint_16 offset_table_count_free; 343 #endif 344 345 #ifdef PNG_READ_QUANTIZE_SUPPORTED 346 png_bytep palette_lookup; /* lookup table for quantizing */ 347 png_bytep quantize_index; /* index translation for palette files */ 348 #endif 349 350 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED 351 png_byte heuristic_method; /* heuristic for row filter selection */ 352 png_byte num_prev_filters; /* number of weights for previous rows */ 353 png_bytep prev_filters; /* filter type(s) of previous row(s) */ 354 png_uint_16p filter_weights; /* weight(s) for previous line(s) */ 355 png_uint_16p inv_filter_weights; /* 1/weight(s) for previous line(s) */ 356 png_uint_16p filter_costs; /* relative filter calculation cost */ 357 png_uint_16p inv_filter_costs; /* 1/relative filter calculation cost */ 358 #endif 359 360 /* Options */ 361 #ifdef PNG_SET_OPTION_SUPPORTED 362 png_byte options; /* On/off state (up to 4 options) */ 363 #endif 364 365 #if PNG_LIBPNG_VER < 10700 366 /* To do: remove this from libpng-1.7 */ 367 #ifdef PNG_TIME_RFC1123_SUPPORTED 368 char time_buffer[29]; /* String to hold RFC 1123 time text */ 369 #endif 370 #endif 371 372 /* New members added in libpng-1.0.6 */ 373 374 png_uint_32 free_me; /* flags items libpng is responsible for freeing */ 375 376 #ifdef PNG_USER_CHUNKS_SUPPORTED 377 png_voidp user_chunk_ptr; 378 #ifdef PNG_READ_USER_CHUNKS_SUPPORTED 379 png_user_chunk_ptr read_user_chunk_fn; /* user read chunk handler */ 380 #endif 381 #endif 382 383 #ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED 384 int unknown_default; /* As PNG_HANDLE_* */ 385 unsigned int num_chunk_list; /* Number of entries in the list */ 386 png_bytep chunk_list; /* List of png_byte[5]; the textual chunk name 387 * followed by a PNG_HANDLE_* byte */ 388 #endif 389 390 /* New members added in libpng-1.0.3 */ 391 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED 392 png_byte rgb_to_gray_status; 393 /* Added in libpng 1.5.5 to record setting of coefficients: */ 394 png_byte rgb_to_gray_coefficients_set; 395 /* These were changed from png_byte in libpng-1.0.6 */ 396 png_uint_16 rgb_to_gray_red_coeff; 397 png_uint_16 rgb_to_gray_green_coeff; 398 /* deleted in 1.5.5: rgb_to_gray_blue_coeff; */ 399 #endif 400 401 /* New member added in libpng-1.0.4 (renamed in 1.0.9) */ 402 #if defined(PNG_MNG_FEATURES_SUPPORTED) 403 /* Changed from png_byte to png_uint_32 at version 1.2.0 */ 404 png_uint_32 mng_features_permitted; 405 #endif 406 407 /* New member added in libpng-1.0.9, ifdef'ed out in 1.0.12, enabled in 1.2.0 */ 408 #ifdef PNG_MNG_FEATURES_SUPPORTED 409 png_byte filter_type; 410 #endif 411 412 /* New members added in libpng-1.2.0 */ 413 414 /* New members added in libpng-1.0.2 but first enabled by default in 1.2.0 */ 415 #ifdef PNG_USER_MEM_SUPPORTED 416 png_voidp mem_ptr; /* user supplied struct for mem functions */ 417 png_malloc_ptr malloc_fn; /* function for allocating memory */ 418 png_free_ptr free_fn; /* function for freeing memory */ 419 #endif 420 421 /* New member added in libpng-1.0.13 and 1.2.0 */ 422 png_bytep big_row_buf; /* buffer to save current (unfiltered) row */ 423 424 #ifdef PNG_READ_QUANTIZE_SUPPORTED 425 /* The following three members were added at version 1.0.14 and 1.2.4 */ 426 png_bytep quantize_sort; /* working sort array */ 427 png_bytep index_to_palette; /* where the original index currently is 428 in the palette */ 429 png_bytep palette_to_index; /* which original index points to this 430 palette color */ 431 #endif 432 433 /* New members added in libpng-1.0.16 and 1.2.6 */ 434 png_byte compression_type; 435 436 #ifdef PNG_USER_LIMITS_SUPPORTED 437 png_uint_32 user_width_max; 438 png_uint_32 user_height_max; 439 440 /* Added in libpng-1.4.0: Total number of sPLT, text, and unknown 441 * chunks that can be stored (0 means unlimited). 442 */ 443 png_uint_32 user_chunk_cache_max; 444 445 /* Total memory that a zTXt, sPLT, iTXt, iCCP, or unknown chunk 446 * can occupy when decompressed. 0 means unlimited. 447 */ 448 png_alloc_size_t user_chunk_malloc_max; 449 #endif 450 451 /* New member added in libpng-1.0.25 and 1.2.17 */ 452 #ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED 453 /* Temporary storage for unknown chunk that the library doesn't recognize, 454 * used while reading the chunk. 455 */ 456 png_unknown_chunk unknown_chunk; 457 #endif 458 459 /* New member added in libpng-1.2.26 */ 460 png_size_t old_big_row_buf_size; 461 462 #ifdef PNG_READ_SUPPORTED 463 /* New member added in libpng-1.2.30 */ 464 png_bytep read_buffer; /* buffer for reading chunk data */ 465 png_alloc_size_t read_buffer_size; /* current size of the buffer */ 466 #endif 467 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED 468 uInt IDAT_read_size; /* limit on read buffer size for IDAT */ 469 #endif 470 471 #ifdef PNG_IO_STATE_SUPPORTED 472 /* New member added in libpng-1.4.0 */ 473 png_uint_32 io_state; 474 #endif 475 476 /* New member added in libpng-1.5.6 */ 477 png_bytep big_prev_row; 478 479 /* New member added in libpng-1.5.7 */ 480 void (*read_filter[PNG_FILTER_VALUE_LAST-1])(png_row_infop row_info, 481 png_bytep row, png_const_bytep prev_row); 482 483 #ifdef PNG_READ_SUPPORTED 484 #if defined(PNG_COLORSPACE_SUPPORTED) || defined(PNG_GAMMA_SUPPORTED) 485 png_colorspace colorspace; 486 #endif 487 #endif 488 }; 489 #endif /* PNGSTRUCT_H */ 490
