1 2 /* pngstruct.h - header file for PNG reference library 3 * 4 * Last changed in libpng 1.6.24 [August 4, 2016] 5 * Copyright (c) 1998-2002,2004,2006-2016 Glenn Randers-Pehrson 6 * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) 7 * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) 8 * 9 * This code is released under the libpng license. 10 * For conditions of distribution and use, see the disclaimer 11 * and license in png.h 12 */ 13 14 /* The structure that holds the information to read and write PNG files. 15 * The only people who need to care about what is inside of this are the 16 * people who will be modifying the library for their own special needs. 17 * It should NOT be accessed directly by an application. 18 */ 19 20 #ifndef PNGSTRUCT_H 21 #define PNGSTRUCT_H 22 /* zlib.h defines the structure z_stream, an instance of which is included 23 * in this structure and is required for decompressing the LZ compressed 24 * data in PNG files. 25 */ 26 #ifndef ZLIB_CONST 27 /* We must ensure that zlib uses 'const' in declarations. */ 28 # define ZLIB_CONST 29 #endif 30 #include "zlib.h" 31 #ifdef const 32 /* zlib.h sometimes #defines const to nothing, undo this. */ 33 # undef const 34 #endif 35 36 /* zlib.h has mediocre z_const use before 1.2.6, this stuff is for compatibility 37 * with older builds. 38 */ 39 #if ZLIB_VERNUM < 0x1260 40 # define PNGZ_MSG_CAST(s) png_constcast(char*,s) 41 # define PNGZ_INPUT_CAST(b) png_constcast(png_bytep,b) 42 #else 43 # define PNGZ_MSG_CAST(s) (s) 44 # define PNGZ_INPUT_CAST(b) (b) 45 #endif 46 47 /* zlib.h declares a magic type 'uInt' that limits the amount of data that zlib 48 * can handle at once. This type need be no larger than 16 bits (so maximum of 49 * 65535), this define allows us to discover how big it is, but limited by the 50 * maximuum for png_size_t. The value can be overriden in a library build 51 * (pngusr.h, or set it in CPPFLAGS) and it works to set it to a considerably 52 * lower value (e.g. 255 works). A lower value may help memory usage (slightly) 53 * and may even improve performance on some systems (and degrade it on others.) 54 */ 55 #ifndef ZLIB_IO_MAX 56 # define ZLIB_IO_MAX ((uInt)-1) 57 #endif 58 59 #ifdef PNG_WRITE_SUPPORTED 60 /* The type of a compression buffer list used by the write code. */ 61 typedef struct png_compression_buffer 62 { 63 struct png_compression_buffer *next; 64 png_byte output[1]; /* actually zbuf_size */ 65 } png_compression_buffer, *png_compression_bufferp; 66 67 #define PNG_COMPRESSION_BUFFER_SIZE(pp)\ 68 (offsetof(png_compression_buffer, output) + (pp)->zbuffer_size) 69 #endif 70 71 /* Colorspace support; structures used in png_struct, png_info and in internal 72 * functions to hold and communicate information about the color space. 73 * 74 * PNG_COLORSPACE_SUPPORTED is only required if the application will perform 75 * colorspace corrections, otherwise all the colorspace information can be 76 * skipped and the size of libpng can be reduced (significantly) by compiling 77 * out the colorspace support. 78 */ 79 #ifdef PNG_COLORSPACE_SUPPORTED 80 /* The chromaticities of the red, green and blue colorants and the chromaticity 81 * of the corresponding white point (i.e. of rgb(1.0,1.0,1.0)). 82 */ 83 typedef struct png_xy 84 { 85 png_fixed_point redx, redy; 86 png_fixed_point greenx, greeny; 87 png_fixed_point bluex, bluey; 88 png_fixed_point whitex, whitey; 89 } png_xy; 90 91 /* The same data as above but encoded as CIE XYZ values. When this data comes 92 * from chromaticities the sum of the Y values is assumed to be 1.0 93 */ 94 typedef struct png_XYZ 95 { 96 png_fixed_point red_X, red_Y, red_Z; 97 png_fixed_point green_X, green_Y, green_Z; 98 png_fixed_point blue_X, blue_Y, blue_Z; 99 } png_XYZ; 100 #endif /* COLORSPACE */ 101 102 #if defined(PNG_COLORSPACE_SUPPORTED) || defined(PNG_GAMMA_SUPPORTED) 103 /* A colorspace is all the above plus, potentially, profile information; 104 * however at present libpng does not use the profile internally so it is only 105 * stored in the png_info struct (if iCCP is supported.) The rendering intent 106 * is retained here and is checked. 107 * 108 * The file gamma encoding information is also stored here and gamma correction 109 * is done by libpng, whereas color correction must currently be done by the 110 * application. 111 */ 112 typedef struct png_colorspace 113 { 114 #ifdef PNG_GAMMA_SUPPORTED 115 png_fixed_point gamma; /* File gamma */ 116 #endif 117 118 #ifdef PNG_COLORSPACE_SUPPORTED 119 png_xy end_points_xy; /* End points as chromaticities */ 120 png_XYZ end_points_XYZ; /* End points as CIE XYZ colorant values */ 121 png_uint_16 rendering_intent; /* Rendering intent of a profile */ 122 #endif 123 124 /* Flags are always defined to simplify the code. */ 125 png_uint_16 flags; /* As defined below */ 126 } png_colorspace, * PNG_RESTRICT png_colorspacerp; 127 128 typedef const png_colorspace * PNG_RESTRICT png_const_colorspacerp; 129 130 /* General flags for the 'flags' field */ 131 #define PNG_COLORSPACE_HAVE_GAMMA 0x0001 132 #define PNG_COLORSPACE_HAVE_ENDPOINTS 0x0002 133 #define PNG_COLORSPACE_HAVE_INTENT 0x0004 134 #define PNG_COLORSPACE_FROM_gAMA 0x0008 135 #define PNG_COLORSPACE_FROM_cHRM 0x0010 136 #define PNG_COLORSPACE_FROM_sRGB 0x0020 137 #define PNG_COLORSPACE_ENDPOINTS_MATCH_sRGB 0x0040 138 #define PNG_COLORSPACE_MATCHES_sRGB 0x0080 /* exact match on profile */ 139 #define PNG_COLORSPACE_INVALID 0x8000 140 #define PNG_COLORSPACE_CANCEL(flags) (0xffff ^ (flags)) 141 #endif /* COLORSPACE || GAMMA */ 142 143 struct png_struct_def 144 { 145 #ifdef PNG_SETJMP_SUPPORTED 146 jmp_buf jmp_buf_local; /* New name in 1.6.0 for jmp_buf in png_struct */ 147 png_longjmp_ptr longjmp_fn;/* setjmp non-local goto function. */ 148 jmp_buf *jmp_buf_ptr; /* passed to longjmp_fn */ 149 size_t jmp_buf_size; /* size of the above, if allocated */ 150 #endif 151 png_error_ptr error_fn; /* function for printing errors and aborting */ 152 #ifdef PNG_WARNINGS_SUPPORTED 153 png_error_ptr warning_fn; /* function for printing warnings */ 154 #endif 155 png_voidp error_ptr; /* user supplied struct for error functions */ 156 png_rw_ptr write_data_fn; /* function for writing output data */ 157 png_rw_ptr read_data_fn; /* function for reading input data */ 158 png_voidp io_ptr; /* ptr to application struct for I/O functions */ 159 160 #ifdef PNG_READ_USER_TRANSFORM_SUPPORTED 161 png_user_transform_ptr read_user_transform_fn; /* user read transform */ 162 #endif 163 164 #ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED 165 png_user_transform_ptr write_user_transform_fn; /* user write transform */ 166 #endif 167 168 /* These were added in libpng-1.0.2 */ 169 #ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED 170 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \ 171 defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) 172 png_voidp user_transform_ptr; /* user supplied struct for user transform */ 173 png_byte user_transform_depth; /* bit depth of user transformed pixels */ 174 png_byte user_transform_channels; /* channels in user transformed pixels */ 175 #endif 176 #endif 177 178 png_uint_32 mode; /* tells us where we are in the PNG file */ 179 png_uint_32 flags; /* flags indicating various things to libpng */ 180 png_uint_32 transformations; /* which transformations to perform */ 181 182 png_uint_32 zowner; /* ID (chunk type) of zstream owner, 0 if none */ 183 z_stream zstream; /* decompression structure */ 184 185 #ifdef PNG_WRITE_SUPPORTED 186 png_compression_bufferp zbuffer_list; /* Created on demand during write */ 187 uInt zbuffer_size; /* size of the actual buffer */ 188 189 int zlib_level; /* holds zlib compression level */ 190 int zlib_method; /* holds zlib compression method */ 191 int zlib_window_bits; /* holds zlib compression window bits */ 192 int zlib_mem_level; /* holds zlib compression memory level */ 193 int zlib_strategy; /* holds zlib compression strategy */ 194 #endif 195 /* Added at libpng 1.5.4 */ 196 #ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED 197 int zlib_text_level; /* holds zlib compression level */ 198 int zlib_text_method; /* holds zlib compression method */ 199 int zlib_text_window_bits; /* holds zlib compression window bits */ 200 int zlib_text_mem_level; /* holds zlib compression memory level */ 201 int zlib_text_strategy; /* holds zlib compression strategy */ 202 #endif 203 /* End of material added at libpng 1.5.4 */ 204 /* Added at libpng 1.6.0 */ 205 #ifdef PNG_WRITE_SUPPORTED 206 int zlib_set_level; /* Actual values set into the zstream on write */ 207 int zlib_set_method; 208 int zlib_set_window_bits; 209 int zlib_set_mem_level; 210 int zlib_set_strategy; 211 #endif 212 213 png_uint_32 width; /* width of image in pixels */ 214 png_uint_32 height; /* height of image in pixels */ 215 png_uint_32 num_rows; /* number of rows in current pass */ 216 png_uint_32 usr_width; /* width of row at start of write */ 217 png_size_t rowbytes; /* size of row in bytes */ 218 png_uint_32 iwidth; /* width of current interlaced row in pixels */ 219 png_uint_32 row_number; /* current row in interlace pass */ 220 png_uint_32 chunk_name; /* PNG_CHUNK() id of current chunk */ 221 png_bytep prev_row; /* buffer to save previous (unfiltered) row. 222 * While reading this is a pointer into 223 * big_prev_row; while writing it is separately 224 * allocated if needed. 225 */ 226 png_bytep row_buf; /* buffer to save current (unfiltered) row. 227 * While reading, this is a pointer into 228 * big_row_buf; while writing it is separately 229 * allocated. 230 */ 231 #ifdef PNG_WRITE_FILTER_SUPPORTED 232 png_bytep try_row; /* buffer to save trial row when filtering */ 233 png_bytep tst_row; /* buffer to save best trial row when filtering */ 234 #endif 235 png_size_t info_rowbytes; /* Added in 1.5.4: cache of updated row bytes */ 236 237 png_uint_32 idat_size; /* current IDAT size for read */ 238 png_uint_32 crc; /* current chunk CRC value */ 239 png_colorp palette; /* palette from the input file */ 240 png_uint_16 num_palette; /* number of color entries in palette */ 241 242 /* Added at libpng-1.5.10 */ 243 #ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED 244 int num_palette_max; /* maximum palette index found in IDAT */ 245 #endif 246 247 png_uint_16 num_trans; /* number of transparency values */ 248 png_byte compression; /* file compression type (always 0) */ 249 png_byte filter; /* file filter type (always 0) */ 250 png_byte interlaced; /* PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */ 251 png_byte pass; /* current interlace pass (0 - 6) */ 252 png_byte do_filter; /* row filter flags (see PNG_FILTER_ in png.h ) */ 253 png_byte color_type; /* color type of file */ 254 png_byte bit_depth; /* bit depth of file */ 255 png_byte usr_bit_depth; /* bit depth of users row: write only */ 256 png_byte pixel_depth; /* number of bits per pixel */ 257 png_byte channels; /* number of channels in file */ 258 #ifdef PNG_WRITE_SUPPORTED 259 png_byte usr_channels; /* channels at start of write: write only */ 260 #endif 261 png_byte sig_bytes; /* magic bytes read/written from start of file */ 262 png_byte maximum_pixel_depth; 263 /* pixel depth used for the row buffers */ 264 png_byte transformed_pixel_depth; 265 /* pixel depth after read/write transforms */ 266 #if PNG_ZLIB_VERNUM >= 0x1240 267 png_byte zstream_start; /* at start of an input zlib stream */ 268 #endif /* Zlib >= 1.2.4 */ 269 #if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED) 270 png_uint_16 filler; /* filler bytes for pixel expansion */ 271 #endif 272 273 #if defined(PNG_bKGD_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) ||\ 274 defined(PNG_READ_ALPHA_MODE_SUPPORTED) 275 png_byte background_gamma_type; 276 png_fixed_point background_gamma; 277 png_color_16 background; /* background color in screen gamma space */ 278 #ifdef PNG_READ_GAMMA_SUPPORTED 279 png_color_16 background_1; /* background normalized to gamma 1.0 */ 280 #endif 281 #endif /* bKGD */ 282 283 #ifdef PNG_WRITE_FLUSH_SUPPORTED 284 png_flush_ptr output_flush_fn; /* Function for flushing output */ 285 png_uint_32 flush_dist; /* how many rows apart to flush, 0 - no flush */ 286 png_uint_32 flush_rows; /* number of rows written since last flush */ 287 #endif 288 289 #ifdef PNG_READ_GAMMA_SUPPORTED 290 int gamma_shift; /* number of "insignificant" bits in 16-bit gamma */ 291 png_fixed_point screen_gamma; /* screen gamma value (display_exponent) */ 292 293 png_bytep gamma_table; /* gamma table for 8-bit depth files */ 294 png_uint_16pp gamma_16_table; /* gamma table for 16-bit depth files */ 295 #if defined(PNG_READ_BACKGROUND_SUPPORTED) || \ 296 defined(PNG_READ_ALPHA_MODE_SUPPORTED) || \ 297 defined(PNG_READ_RGB_TO_GRAY_SUPPORTED) 298 png_bytep gamma_from_1; /* converts from 1.0 to screen */ 299 png_bytep gamma_to_1; /* converts from file to 1.0 */ 300 png_uint_16pp gamma_16_from_1; /* converts from 1.0 to screen */ 301 png_uint_16pp gamma_16_to_1; /* converts from file to 1.0 */ 302 #endif /* READ_BACKGROUND || READ_ALPHA_MODE || RGB_TO_GRAY */ 303 #endif 304 305 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_sBIT_SUPPORTED) 306 png_color_8 sig_bit; /* significant bits in each available channel */ 307 #endif 308 309 #if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED) 310 png_color_8 shift; /* shift for significant bit tranformation */ 311 #endif 312 313 #if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) \ 314 || defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) 315 png_bytep trans_alpha; /* alpha values for paletted files */ 316 png_color_16 trans_color; /* transparent color for non-paletted files */ 317 #endif 318 319 png_read_status_ptr read_row_fn; /* called after each row is decoded */ 320 png_write_status_ptr write_row_fn; /* called after each row is encoded */ 321 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED 322 png_progressive_info_ptr info_fn; /* called after header data fully read */ 323 png_progressive_row_ptr row_fn; /* called after a prog. row is decoded */ 324 png_progressive_end_ptr end_fn; /* called after image is complete */ 325 png_bytep save_buffer_ptr; /* current location in save_buffer */ 326 png_bytep save_buffer; /* buffer for previously read data */ 327 png_bytep current_buffer_ptr; /* current location in current_buffer */ 328 png_bytep current_buffer; /* buffer for recently used data */ 329 png_uint_32 push_length; /* size of current input chunk */ 330 png_uint_32 skip_length; /* bytes to skip in input data */ 331 png_size_t save_buffer_size; /* amount of data now in save_buffer */ 332 png_size_t save_buffer_max; /* total size of save_buffer */ 333 png_size_t buffer_size; /* total amount of available input data */ 334 png_size_t current_buffer_size; /* amount of data now in current_buffer */ 335 int process_mode; /* what push library is currently doing */ 336 int cur_palette; /* current push library palette index */ 337 338 #endif /* PROGRESSIVE_READ */ 339 340 #if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__) 341 /* For the Borland special 64K segment handler */ 342 png_bytepp offset_table_ptr; 343 png_bytep offset_table; 344 png_uint_16 offset_table_number; 345 png_uint_16 offset_table_count; 346 png_uint_16 offset_table_count_free; 347 #endif 348 349 #ifdef PNG_READ_QUANTIZE_SUPPORTED 350 png_bytep palette_lookup; /* lookup table for quantizing */ 351 png_bytep quantize_index; /* index translation for palette files */ 352 #endif 353 354 /* Options */ 355 #ifdef PNG_SET_OPTION_SUPPORTED 356 png_byte options; /* On/off state (up to 4 options) */ 357 #endif 358 359 #if PNG_LIBPNG_VER < 10700 360 /* To do: remove this from libpng-1.7 */ 361 #ifdef PNG_TIME_RFC1123_SUPPORTED 362 char time_buffer[29]; /* String to hold RFC 1123 time text */ 363 #endif 364 #endif 365 366 /* New members added in libpng-1.0.6 */ 367 368 png_uint_32 free_me; /* flags items libpng is responsible for freeing */ 369 370 #ifdef PNG_USER_CHUNKS_SUPPORTED 371 png_voidp user_chunk_ptr; 372 #ifdef PNG_READ_USER_CHUNKS_SUPPORTED 373 png_user_chunk_ptr read_user_chunk_fn; /* user read chunk handler */ 374 #endif 375 #endif 376 377 #ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED 378 int unknown_default; /* As PNG_HANDLE_* */ 379 unsigned int num_chunk_list; /* Number of entries in the list */ 380 png_bytep chunk_list; /* List of png_byte[5]; the textual chunk name 381 * followed by a PNG_HANDLE_* byte */ 382 #endif 383 384 /* New members added in libpng-1.0.3 */ 385 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED 386 png_byte rgb_to_gray_status; 387 /* Added in libpng 1.5.5 to record setting of coefficients: */ 388 png_byte rgb_to_gray_coefficients_set; 389 /* These were changed from png_byte in libpng-1.0.6 */ 390 png_uint_16 rgb_to_gray_red_coeff; 391 png_uint_16 rgb_to_gray_green_coeff; 392 /* deleted in 1.5.5: rgb_to_gray_blue_coeff; */ 393 #endif 394 395 /* New member added in libpng-1.0.4 (renamed in 1.0.9) */ 396 #if defined(PNG_MNG_FEATURES_SUPPORTED) 397 /* Changed from png_byte to png_uint_32 at version 1.2.0 */ 398 png_uint_32 mng_features_permitted; 399 #endif 400 401 /* New member added in libpng-1.0.9, ifdef'ed out in 1.0.12, enabled in 1.2.0 */ 402 #ifdef PNG_MNG_FEATURES_SUPPORTED 403 png_byte filter_type; 404 #endif 405 406 /* New members added in libpng-1.2.0 */ 407 408 /* New members added in libpng-1.0.2 but first enabled by default in 1.2.0 */ 409 #ifdef PNG_USER_MEM_SUPPORTED 410 png_voidp mem_ptr; /* user supplied struct for mem functions */ 411 png_malloc_ptr malloc_fn; /* function for allocating memory */ 412 png_free_ptr free_fn; /* function for freeing memory */ 413 #endif 414 415 /* New member added in libpng-1.0.13 and 1.2.0 */ 416 png_bytep big_row_buf; /* buffer to save current (unfiltered) row */ 417 418 #ifdef PNG_READ_QUANTIZE_SUPPORTED 419 /* The following three members were added at version 1.0.14 and 1.2.4 */ 420 png_bytep quantize_sort; /* working sort array */ 421 png_bytep index_to_palette; /* where the original index currently is 422 in the palette */ 423 png_bytep palette_to_index; /* which original index points to this 424 palette color */ 425 #endif 426 427 /* New members added in libpng-1.0.16 and 1.2.6 */ 428 png_byte compression_type; 429 430 #ifdef PNG_USER_LIMITS_SUPPORTED 431 png_uint_32 user_width_max; 432 png_uint_32 user_height_max; 433 434 /* Added in libpng-1.4.0: Total number of sPLT, text, and unknown 435 * chunks that can be stored (0 means unlimited). 436 */ 437 png_uint_32 user_chunk_cache_max; 438 439 /* Total memory that a zTXt, sPLT, iTXt, iCCP, or unknown chunk 440 * can occupy when decompressed. 0 means unlimited. 441 */ 442 png_alloc_size_t user_chunk_malloc_max; 443 #endif 444 445 /* New member added in libpng-1.0.25 and 1.2.17 */ 446 #ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED 447 /* Temporary storage for unknown chunk that the library doesn't recognize, 448 * used while reading the chunk. 449 */ 450 png_unknown_chunk unknown_chunk; 451 #endif 452 453 /* New member added in libpng-1.2.26 */ 454 png_size_t old_big_row_buf_size; 455 456 #ifdef PNG_READ_SUPPORTED 457 /* New member added in libpng-1.2.30 */ 458 png_bytep read_buffer; /* buffer for reading chunk data */ 459 png_alloc_size_t read_buffer_size; /* current size of the buffer */ 460 #endif 461 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED 462 uInt IDAT_read_size; /* limit on read buffer size for IDAT */ 463 #endif 464 465 #ifdef PNG_IO_STATE_SUPPORTED 466 /* New member added in libpng-1.4.0 */ 467 png_uint_32 io_state; 468 #endif 469 470 /* New member added in libpng-1.5.6 */ 471 png_bytep big_prev_row; 472 473 /* New member added in libpng-1.5.7 */ 474 void (*read_filter[PNG_FILTER_VALUE_LAST-1])(png_row_infop row_info, 475 png_bytep row, png_const_bytep prev_row); 476 477 #ifdef PNG_READ_SUPPORTED 478 #if defined(PNG_COLORSPACE_SUPPORTED) || defined(PNG_GAMMA_SUPPORTED) 479 png_colorspace colorspace; 480 #endif 481 #endif 482 }; 483 #endif /* PNGSTRUCT_H */ 484
