1 2 /* pngstruct.h - header file for PNG reference library 3 * 4 * Copyright (c) 2018-2019 Cosmin Truta 5 * Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson 6 * Copyright (c) 1996-1997 Andreas Dilger 7 * 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 * maximum for size_t. The value can be overridden 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 #ifdef PNG_MULTY_LINE_ENABLE 144 // OH ISSUE: png optimize 145 #define PNG_FILTER_VALUE_UP_X2 (6) // PNG_FILTER_VALUE_UP + 4 146 #define PNG_FILTER_VALUE_AVG_X2 (7) // PNG_FILTER_VALUE_AVG + 4 147 #define PNG_FILTER_VALUE_PAETH_X2 (8) // PNG_FILTER_VALUE_PAETH + 4 148 #define PNG_FILTER_VALUE_LAST_X2 (9) // PNG_FILTER_VALUE_LAST + 4 149 #endif 150 151 struct png_struct_def 152 { 153 #ifdef PNG_SETJMP_SUPPORTED 154 jmp_buf jmp_buf_local; /* New name in 1.6.0 for jmp_buf in png_struct */ 155 png_longjmp_ptr longjmp_fn;/* setjmp non-local goto function. */ 156 jmp_buf *jmp_buf_ptr; /* passed to longjmp_fn */ 157 size_t jmp_buf_size; /* size of the above, if allocated */ 158 #endif 159 png_error_ptr error_fn; /* function for printing errors and aborting */ 160 #ifdef PNG_WARNINGS_SUPPORTED 161 png_error_ptr warning_fn; /* function for printing warnings */ 162 #endif 163 png_voidp error_ptr; /* user supplied struct for error functions */ 164 png_rw_ptr write_data_fn; /* function for writing output data */ 165 png_rw_ptr read_data_fn; /* function for reading input data */ 166 png_voidp io_ptr; /* ptr to application struct for I/O functions */ 167 168 #ifdef PNG_READ_USER_TRANSFORM_SUPPORTED 169 png_user_transform_ptr read_user_transform_fn; /* user read transform */ 170 #endif 171 172 #ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED 173 png_user_transform_ptr write_user_transform_fn; /* user write transform */ 174 #endif 175 176 /* These were added in libpng-1.0.2 */ 177 #ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED 178 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \ 179 defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) 180 png_voidp user_transform_ptr; /* user supplied struct for user transform */ 181 png_byte user_transform_depth; /* bit depth of user transformed pixels */ 182 png_byte user_transform_channels; /* channels in user transformed pixels */ 183 #endif 184 #endif 185 186 png_uint_32 mode; /* tells us where we are in the PNG file */ 187 png_uint_32 flags; /* flags indicating various things to libpng */ 188 png_uint_32 transformations; /* which transformations to perform */ 189 190 png_uint_32 zowner; /* ID (chunk type) of zstream owner, 0 if none */ 191 z_stream zstream; /* decompression structure */ 192 193 #ifdef PNG_WRITE_SUPPORTED 194 png_compression_bufferp zbuffer_list; /* Created on demand during write */ 195 uInt zbuffer_size; /* size of the actual buffer */ 196 197 int zlib_level; /* holds zlib compression level */ 198 int zlib_method; /* holds zlib compression method */ 199 int zlib_window_bits; /* holds zlib compression window bits */ 200 int zlib_mem_level; /* holds zlib compression memory level */ 201 int zlib_strategy; /* holds zlib compression strategy */ 202 #endif 203 /* Added at libpng 1.5.4 */ 204 #ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED 205 int zlib_text_level; /* holds zlib compression level */ 206 int zlib_text_method; /* holds zlib compression method */ 207 int zlib_text_window_bits; /* holds zlib compression window bits */ 208 int zlib_text_mem_level; /* holds zlib compression memory level */ 209 int zlib_text_strategy; /* holds zlib compression strategy */ 210 #endif 211 /* End of material added at libpng 1.5.4 */ 212 /* Added at libpng 1.6.0 */ 213 #ifdef PNG_WRITE_SUPPORTED 214 int zlib_set_level; /* Actual values set into the zstream on write */ 215 int zlib_set_method; 216 int zlib_set_window_bits; 217 int zlib_set_mem_level; 218 int zlib_set_strategy; 219 #endif 220 221 png_uint_32 width; /* width of image in pixels */ 222 png_uint_32 height; /* height of image in pixels */ 223 png_uint_32 num_rows; /* number of rows in current pass */ 224 png_uint_32 usr_width; /* width of row at start of write */ 225 size_t rowbytes; /* size of row in bytes */ 226 png_uint_32 iwidth; /* width of current interlaced row in pixels */ 227 png_uint_32 row_number; /* current row in interlace pass */ 228 png_uint_32 chunk_name; /* PNG_CHUNK() id of current chunk */ 229 png_bytep prev_row; /* buffer to save previous (unfiltered) row. 230 * While reading this is a pointer into 231 * big_prev_row; while writing it is separately 232 * allocated if needed. 233 */ 234 png_bytep row_buf; /* buffer to save current (unfiltered) row. 235 * While reading, this is a pointer into 236 * big_row_buf; while writing it is separately 237 * allocated. 238 */ 239 #ifdef PNG_WRITE_FILTER_SUPPORTED 240 png_bytep try_row; /* buffer to save trial row when filtering */ 241 png_bytep tst_row; /* buffer to save best trial row when filtering */ 242 #endif 243 size_t info_rowbytes; /* Added in 1.5.4: cache of updated row bytes */ 244 245 png_uint_32 idat_size; /* current IDAT size for read */ 246 png_uint_32 crc; /* current chunk CRC value */ 247 png_colorp palette; /* palette from the input file */ 248 png_uint_16 num_palette; /* number of color entries in palette */ 249 250 /* Added at libpng-1.5.10 */ 251 #ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED 252 int num_palette_max; /* maximum palette index found in IDAT */ 253 #endif 254 255 png_uint_16 num_trans; /* number of transparency values */ 256 png_byte compression; /* file compression type (always 0) */ 257 png_byte filter; /* file filter type (always 0) */ 258 png_byte interlaced; /* PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */ 259 png_byte pass; /* current interlace pass (0 - 6) */ 260 png_byte do_filter; /* row filter flags (see PNG_FILTER_ in png.h ) */ 261 png_byte color_type; /* color type of file */ 262 png_byte bit_depth; /* bit depth of file */ 263 png_byte usr_bit_depth; /* bit depth of users row: write only */ 264 png_byte pixel_depth; /* number of bits per pixel */ 265 png_byte channels; /* number of channels in file */ 266 #ifdef PNG_WRITE_SUPPORTED 267 png_byte usr_channels; /* channels at start of write: write only */ 268 #endif 269 png_byte sig_bytes; /* magic bytes read/written from start of file */ 270 png_byte maximum_pixel_depth; 271 /* pixel depth used for the row buffers */ 272 png_byte transformed_pixel_depth; 273 /* pixel depth after read/write transforms */ 274 #if ZLIB_VERNUM >= 0x1240 275 png_byte zstream_start; /* at start of an input zlib stream */ 276 #endif /* Zlib >= 1.2.4 */ 277 #if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED) 278 png_uint_16 filler; /* filler bytes for pixel expansion */ 279 #endif 280 281 #if defined(PNG_bKGD_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) ||\ 282 defined(PNG_READ_ALPHA_MODE_SUPPORTED) 283 png_byte background_gamma_type; 284 png_fixed_point background_gamma; 285 png_color_16 background; /* background color in screen gamma space */ 286 #ifdef PNG_READ_GAMMA_SUPPORTED 287 png_color_16 background_1; /* background normalized to gamma 1.0 */ 288 #endif 289 #endif /* bKGD */ 290 291 #ifdef PNG_WRITE_FLUSH_SUPPORTED 292 png_flush_ptr output_flush_fn; /* Function for flushing output */ 293 png_uint_32 flush_dist; /* how many rows apart to flush, 0 - no flush */ 294 png_uint_32 flush_rows; /* number of rows written since last flush */ 295 #endif 296 297 #ifdef PNG_READ_GAMMA_SUPPORTED 298 int gamma_shift; /* number of "insignificant" bits in 16-bit gamma */ 299 png_fixed_point screen_gamma; /* screen gamma value (display_exponent) */ 300 301 png_bytep gamma_table; /* gamma table for 8-bit depth files */ 302 png_uint_16pp gamma_16_table; /* gamma table for 16-bit depth files */ 303 #if defined(PNG_READ_BACKGROUND_SUPPORTED) || \ 304 defined(PNG_READ_ALPHA_MODE_SUPPORTED) || \ 305 defined(PNG_READ_RGB_TO_GRAY_SUPPORTED) 306 png_bytep gamma_from_1; /* converts from 1.0 to screen */ 307 png_bytep gamma_to_1; /* converts from file to 1.0 */ 308 png_uint_16pp gamma_16_from_1; /* converts from 1.0 to screen */ 309 png_uint_16pp gamma_16_to_1; /* converts from file to 1.0 */ 310 #endif /* READ_BACKGROUND || READ_ALPHA_MODE || RGB_TO_GRAY */ 311 #endif 312 313 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_sBIT_SUPPORTED) 314 png_color_8 sig_bit; /* significant bits in each available channel */ 315 #endif 316 317 #if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED) 318 png_color_8 shift; /* shift for significant bit transformation */ 319 #endif 320 321 #if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) \ 322 || defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) 323 png_bytep trans_alpha; /* alpha values for paletted files */ 324 png_color_16 trans_color; /* transparent color for non-paletted files */ 325 #endif 326 327 png_read_status_ptr read_row_fn; /* called after each row is decoded */ 328 png_write_status_ptr write_row_fn; /* called after each row is encoded */ 329 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED 330 png_progressive_info_ptr info_fn; /* called after header data fully read */ 331 png_progressive_row_ptr row_fn; /* called after a prog. row is decoded */ 332 png_progressive_end_ptr end_fn; /* called after image is complete */ 333 png_bytep save_buffer_ptr; /* current location in save_buffer */ 334 png_bytep save_buffer; /* buffer for previously read data */ 335 png_bytep current_buffer_ptr; /* current location in current_buffer */ 336 png_bytep current_buffer; /* buffer for recently used data */ 337 png_uint_32 push_length; /* size of current input chunk */ 338 png_uint_32 skip_length; /* bytes to skip in input data */ 339 size_t save_buffer_size; /* amount of data now in save_buffer */ 340 size_t save_buffer_max; /* total size of save_buffer */ 341 size_t buffer_size; /* total amount of available input data */ 342 size_t current_buffer_size; /* amount of data now in current_buffer */ 343 int process_mode; /* what push library is currently doing */ 344 int cur_palette; /* current push library palette index */ 345 346 #endif /* PROGRESSIVE_READ */ 347 348 #if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__) 349 /* For the Borland special 64K segment handler */ 350 png_bytepp offset_table_ptr; 351 png_bytep offset_table; 352 png_uint_16 offset_table_number; 353 png_uint_16 offset_table_count; 354 png_uint_16 offset_table_count_free; 355 #endif 356 357 #ifdef PNG_READ_QUANTIZE_SUPPORTED 358 png_bytep palette_lookup; /* lookup table for quantizing */ 359 png_bytep quantize_index; /* index translation for palette files */ 360 #endif 361 362 /* Options */ 363 #ifdef PNG_SET_OPTION_SUPPORTED 364 png_uint_32 options; /* On/off state (up to 16 options) */ 365 #endif 366 367 #if PNG_LIBPNG_VER < 10700 368 /* To do: remove this from libpng-1.7 */ 369 #ifdef PNG_TIME_RFC1123_SUPPORTED 370 char time_buffer[29]; /* String to hold RFC 1123 time text */ 371 #endif 372 #endif 373 374 /* New members added in libpng-1.0.6 */ 375 376 png_uint_32 free_me; /* flags items libpng is responsible for freeing */ 377 378 #ifdef PNG_USER_CHUNKS_SUPPORTED 379 png_voidp user_chunk_ptr; 380 #ifdef PNG_READ_USER_CHUNKS_SUPPORTED 381 png_user_chunk_ptr read_user_chunk_fn; /* user read chunk handler */ 382 #endif 383 #endif 384 385 #ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED 386 int unknown_default; /* As PNG_HANDLE_* */ 387 unsigned int num_chunk_list; /* Number of entries in the list */ 388 png_bytep chunk_list; /* List of png_byte[5]; the textual chunk name 389 * followed by a PNG_HANDLE_* byte */ 390 #endif 391 392 /* New members added in libpng-1.0.3 */ 393 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED 394 png_byte rgb_to_gray_status; 395 /* Added in libpng 1.5.5 to record setting of coefficients: */ 396 png_byte rgb_to_gray_coefficients_set; 397 /* These were changed from png_byte in libpng-1.0.6 */ 398 png_uint_16 rgb_to_gray_red_coeff; 399 png_uint_16 rgb_to_gray_green_coeff; 400 /* deleted in 1.5.5: rgb_to_gray_blue_coeff; */ 401 #endif 402 403 /* New member added in libpng-1.6.36 */ 404 #if defined(PNG_READ_EXPAND_SUPPORTED) && \ 405 defined(PNG_ARM_NEON_IMPLEMENTATION) 406 png_bytep riffled_palette; /* buffer for accelerated palette expansion */ 407 #endif 408 409 /* New member added in libpng-1.0.4 (renamed in 1.0.9) */ 410 #if defined(PNG_MNG_FEATURES_SUPPORTED) 411 /* Changed from png_byte to png_uint_32 at version 1.2.0 */ 412 png_uint_32 mng_features_permitted; 413 #endif 414 415 /* New member added in libpng-1.0.9, ifdef'ed out in 1.0.12, enabled in 1.2.0 */ 416 #ifdef PNG_MNG_FEATURES_SUPPORTED 417 png_byte filter_type; 418 #endif 419 420 /* New members added in libpng-1.2.0 */ 421 422 /* New members added in libpng-1.0.2 but first enabled by default in 1.2.0 */ 423 #ifdef PNG_USER_MEM_SUPPORTED 424 png_voidp mem_ptr; /* user supplied struct for mem functions */ 425 png_malloc_ptr malloc_fn; /* function for allocating memory */ 426 png_free_ptr free_fn; /* function for freeing memory */ 427 #endif 428 429 /* New member added in libpng-1.0.13 and 1.2.0 */ 430 png_bytep big_row_buf; /* buffer to save current (unfiltered) row */ 431 432 #ifdef PNG_READ_QUANTIZE_SUPPORTED 433 /* The following three members were added at version 1.0.14 and 1.2.4 */ 434 png_bytep quantize_sort; /* working sort array */ 435 png_bytep index_to_palette; /* where the original index currently is 436 in the palette */ 437 png_bytep palette_to_index; /* which original index points to this 438 palette color */ 439 #endif 440 441 /* New members added in libpng-1.0.16 and 1.2.6 */ 442 png_byte compression_type; 443 444 #ifdef PNG_USER_LIMITS_SUPPORTED 445 png_uint_32 user_width_max; 446 png_uint_32 user_height_max; 447 448 /* Added in libpng-1.4.0: Total number of sPLT, text, and unknown 449 * chunks that can be stored (0 means unlimited). 450 */ 451 png_uint_32 user_chunk_cache_max; 452 453 /* Total memory that a zTXt, sPLT, iTXt, iCCP, or unknown chunk 454 * can occupy when decompressed. 0 means unlimited. 455 */ 456 png_alloc_size_t user_chunk_malloc_max; 457 #endif 458 459 /* New member added in libpng-1.0.25 and 1.2.17 */ 460 #ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED 461 /* Temporary storage for unknown chunk that the library doesn't recognize, 462 * used while reading the chunk. 463 */ 464 png_unknown_chunk unknown_chunk; 465 #endif 466 467 /* New member added in libpng-1.2.26 */ 468 size_t old_big_row_buf_size; 469 470 #ifdef PNG_READ_SUPPORTED 471 /* New member added in libpng-1.2.30 */ 472 png_bytep read_buffer; /* buffer for reading chunk data */ 473 png_alloc_size_t read_buffer_size; /* current size of the buffer */ 474 #endif 475 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED 476 uInt IDAT_read_size; /* limit on read buffer size for IDAT */ 477 #endif 478 479 #ifdef PNG_IO_STATE_SUPPORTED 480 /* New member added in libpng-1.4.0 */ 481 png_uint_32 io_state; 482 #endif 483 484 /* New member added in libpng-1.5.6 */ 485 png_bytep big_prev_row; 486 487 /* New member added in libpng-1.5.7 */ 488 #ifdef PNG_MULTY_LINE_ENABLE 489 // OH ISSUE: png optimize 490 void (*read_filter[PNG_FILTER_VALUE_LAST_X2 - 1])(png_row_infop row_info, 491 png_bytep row, png_const_bytep prev_row); 492 #else 493 void (*read_filter[PNG_FILTER_VALUE_LAST-1])(png_row_infop row_info, 494 png_bytep row, png_const_bytep prev_row); 495 #endif 496 497 #ifdef PNG_READ_SUPPORTED 498 #if defined(PNG_COLORSPACE_SUPPORTED) || defined(PNG_GAMMA_SUPPORTED) 499 png_colorspace colorspace; 500 #endif 501 #endif 502 }; 503 #endif /* PNGSTRUCT_H */ 504