1 2 /* png.h - header file for PNG reference library 3 * 4 * libpng version 1.6.44 5 * 6 * Copyright (c) 2018-2024 Cosmin Truta 7 * Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson 8 * Copyright (c) 1996-1997 Andreas Dilger 9 * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc. 10 * 11 * This code is released under the libpng license. (See LICENSE, below.) 12 * 13 * Authors and maintainers: 14 * libpng versions 0.71, May 1995, through 0.88, January 1996: Guy Schalnat 15 * libpng versions 0.89, June 1996, through 0.96, May 1997: Andreas Dilger 16 * libpng versions 0.97, January 1998, through 1.6.35, July 2018: 17 * Glenn Randers-Pehrson 18 * libpng versions 1.6.36, December 2018, through 1.6.44, September 2024: 19 * Cosmin Truta 20 * See also "Contributing Authors", below. 21 */ 22 23 /* 24 * COPYRIGHT NOTICE, DISCLAIMER, and LICENSE 25 * ========================================= 26 * 27 * PNG Reference Library License version 2 28 * --------------------------------------- 29 * 30 * * Copyright (c) 1995-2024 The PNG Reference Library Authors. 31 * * Copyright (c) 2018-2024 Cosmin Truta. 32 * * Copyright (c) 2000-2002, 2004, 2006-2018 Glenn Randers-Pehrson. 33 * * Copyright (c) 1996-1997 Andreas Dilger. 34 * * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc. 35 * 36 * The software is supplied "as is", without warranty of any kind, 37 * express or implied, including, without limitation, the warranties 38 * of merchantability, fitness for a particular purpose, title, and 39 * non-infringement. In no event shall the Copyright owners, or 40 * anyone distributing the software, be liable for any damages or 41 * other liability, whether in contract, tort or otherwise, arising 42 * from, out of, or in connection with the software, or the use or 43 * other dealings in the software, even if advised of the possibility 44 * of such damage. 45 * 46 * Permission is hereby granted to use, copy, modify, and distribute 47 * this software, or portions hereof, for any purpose, without fee, 48 * subject to the following restrictions: 49 * 50 * 1. The origin of this software must not be misrepresented; you 51 * must not claim that you wrote the original software. If you 52 * use this software in a product, an acknowledgment in the product 53 * documentation would be appreciated, but is not required. 54 * 55 * 2. Altered source versions must be plainly marked as such, and must 56 * not be misrepresented as being the original software. 57 * 58 * 3. This Copyright notice may not be removed or altered from any 59 * source or altered source distribution. 60 * 61 * 62 * PNG Reference Library License version 1 (for libpng 0.5 through 1.6.35) 63 * ----------------------------------------------------------------------- 64 * 65 * libpng versions 1.0.7, July 1, 2000, through 1.6.35, July 15, 2018 are 66 * Copyright (c) 2000-2002, 2004, 2006-2018 Glenn Randers-Pehrson, are 67 * derived from libpng-1.0.6, and are distributed according to the same 68 * disclaimer and license as libpng-1.0.6 with the following individuals 69 * added to the list of Contributing Authors: 70 * 71 * Simon-Pierre Cadieux 72 * Eric S. Raymond 73 * Mans Rullgard 74 * Cosmin Truta 75 * Gilles Vollant 76 * James Yu 77 * Mandar Sahastrabuddhe 78 * Google Inc. 79 * Vadim Barkov 80 * 81 * and with the following additions to the disclaimer: 82 * 83 * There is no warranty against interference with your enjoyment of 84 * the library or against infringement. There is no warranty that our 85 * efforts or the library will fulfill any of your particular purposes 86 * or needs. This library is provided with all faults, and the entire 87 * risk of satisfactory quality, performance, accuracy, and effort is 88 * with the user. 89 * 90 * Some files in the "contrib" directory and some configure-generated 91 * files that are distributed with libpng have other copyright owners, and 92 * are released under other open source licenses. 93 * 94 * libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are 95 * Copyright (c) 1998-2000 Glenn Randers-Pehrson, are derived from 96 * libpng-0.96, and are distributed according to the same disclaimer and 97 * license as libpng-0.96, with the following individuals added to the 98 * list of Contributing Authors: 99 * 100 * Tom Lane 101 * Glenn Randers-Pehrson 102 * Willem van Schaik 103 * 104 * libpng versions 0.89, June 1996, through 0.96, May 1997, are 105 * Copyright (c) 1996-1997 Andreas Dilger, are derived from libpng-0.88, 106 * and are distributed according to the same disclaimer and license as 107 * libpng-0.88, with the following individuals added to the list of 108 * Contributing Authors: 109 * 110 * John Bowler 111 * Kevin Bracey 112 * Sam Bushell 113 * Magnus Holmgren 114 * Greg Roelofs 115 * Tom Tanner 116 * 117 * Some files in the "scripts" directory have other copyright owners, 118 * but are released under this license. 119 * 120 * libpng versions 0.5, May 1995, through 0.88, January 1996, are 121 * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc. 122 * 123 * For the purposes of this copyright and license, "Contributing Authors" 124 * is defined as the following set of individuals: 125 * 126 * Andreas Dilger 127 * Dave Martindale 128 * Guy Eric Schalnat 129 * Paul Schmidt 130 * Tim Wegner 131 * 132 * The PNG Reference Library is supplied "AS IS". The Contributing 133 * Authors and Group 42, Inc. disclaim all warranties, expressed or 134 * implied, including, without limitation, the warranties of 135 * merchantability and of fitness for any purpose. The Contributing 136 * Authors and Group 42, Inc. assume no liability for direct, indirect, 137 * incidental, special, exemplary, or consequential damages, which may 138 * result from the use of the PNG Reference Library, even if advised of 139 * the possibility of such damage. 140 * 141 * Permission is hereby granted to use, copy, modify, and distribute this 142 * source code, or portions hereof, for any purpose, without fee, subject 143 * to the following restrictions: 144 * 145 * 1. The origin of this source code must not be misrepresented. 146 * 147 * 2. Altered versions must be plainly marked as such and must not 148 * be misrepresented as being the original source. 149 * 150 * 3. This Copyright notice may not be removed or altered from any 151 * source or altered source distribution. 152 * 153 * The Contributing Authors and Group 42, Inc. specifically permit, 154 * without fee, and encourage the use of this source code as a component 155 * to supporting the PNG file format in commercial products. If you use 156 * this source code in a product, acknowledgment is not required but would 157 * be appreciated. 158 * 159 * END OF COPYRIGHT NOTICE, DISCLAIMER, and LICENSE. 160 * 161 * TRADEMARK 162 * ========= 163 * 164 * The name "libpng" has not been registered by the Copyright owners 165 * as a trademark in any jurisdiction. However, because libpng has 166 * been distributed and maintained world-wide, continually since 1995, 167 * the Copyright owners claim "common-law trademark protection" in any 168 * jurisdiction where common-law trademark is recognized. 169 */ 170 171 /* 172 * A "png_get_copyright" function is available, for convenient use in "about" 173 * boxes and the like: 174 * 175 * printf("%s", png_get_copyright(NULL)); 176 * 177 * Also, the PNG logo (in PNG format, of course) is supplied in the 178 * files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31). 179 */ 180 181 /* 182 * The contributing authors would like to thank all those who helped 183 * with testing, bug fixes, and patience. This wouldn't have been 184 * possible without all of you. 185 * 186 * Thanks to Frank J. T. Wojcik for helping with the documentation. 187 */ 188 189 /* Note about libpng version numbers: 190 * 191 * Due to various miscommunications, unforeseen code incompatibilities 192 * and occasional factors outside the authors' control, version numbering 193 * on the library has not always been consistent and straightforward. 194 * The following table summarizes matters since version 0.89c, which was 195 * the first widely used release: 196 * 197 * source png.h png.h shared-lib 198 * version string int version 199 * ------- ------ ----- ---------- 200 * 0.89c "1.0 beta 3" 0.89 89 1.0.89 201 * 0.90 "1.0 beta 4" 0.90 90 0.90 [should have been 2.0.90] 202 * 0.95 "1.0 beta 5" 0.95 95 0.95 [should have been 2.0.95] 203 * 0.96 "1.0 beta 6" 0.96 96 0.96 [should have been 2.0.96] 204 * 0.97b "1.00.97 beta 7" 1.00.97 97 1.0.1 [should have been 2.0.97] 205 * 0.97c 0.97 97 2.0.97 206 * 0.98 0.98 98 2.0.98 207 * 0.99 0.99 98 2.0.99 208 * 0.99a-m 0.99 99 2.0.99 209 * 1.00 1.00 100 2.1.0 [100 should be 10000] 210 * 1.0.0 (from here on, the 100 2.1.0 [100 should be 10000] 211 * 1.0.1 png.h string is 10001 2.1.0 212 * 1.0.1a-e identical to the 10002 from here on, the shared library 213 * 1.0.2 source version) 10002 is 2.V where V is the source code 214 * 1.0.2a-b 10003 version, except as noted. 215 * 1.0.3 10003 216 * 1.0.3a-d 10004 217 * 1.0.4 10004 218 * 1.0.4a-f 10005 219 * 1.0.5 (+ 2 patches) 10005 220 * 1.0.5a-d 10006 221 * 1.0.5e-r 10100 (not source compatible) 222 * 1.0.5s-v 10006 (not binary compatible) 223 * 1.0.6 (+ 3 patches) 10006 (still binary incompatible) 224 * 1.0.6d-f 10007 (still binary incompatible) 225 * 1.0.6g 10007 226 * 1.0.6h 10007 10.6h (testing xy.z so-numbering) 227 * 1.0.6i 10007 10.6i 228 * 1.0.6j 10007 2.1.0.6j (incompatible with 1.0.0) 229 * 1.0.7beta11-14 DLLNUM 10007 2.1.0.7beta11-14 (binary compatible) 230 * 1.0.7beta15-18 1 10007 2.1.0.7beta15-18 (binary compatible) 231 * 1.0.7rc1-2 1 10007 2.1.0.7rc1-2 (binary compatible) 232 * 1.0.7 1 10007 (still compatible) 233 * ... 234 * 1.0.69 10 10069 10.so.0.69[.0] 235 * ... 236 * 1.2.59 13 10259 12.so.0.59[.0] 237 * ... 238 * 1.4.20 14 10420 14.so.0.20[.0] 239 * ... 240 * 1.5.30 15 10530 15.so.15.30[.0] 241 * ... 242 * 1.6.44 16 10644 16.so.16.44[.0] 243 * 244 * Henceforth the source version will match the shared-library major and 245 * minor numbers; the shared-library major version number will be used for 246 * changes in backward compatibility, as it is intended. 247 * The PNG_LIBPNG_VER macro, which is not used within libpng but is 248 * available for applications, is an unsigned integer of the form XYYZZ 249 * corresponding to the source version X.Y.Z (leading zeros in Y and Z). 250 * Beta versions were given the previous public release number plus a 251 * letter, until version 1.0.6j; from then on they were given the upcoming 252 * public release number plus "betaNN" or "rcNN". 253 * 254 * Binary incompatibility exists only when applications make direct access 255 * to the info_ptr or png_ptr members through png.h, and the compiled 256 * application is loaded with a different version of the library. 257 * 258 * See libpng.txt or libpng.3 for more information. The PNG specification 259 * is available as a W3C Recommendation and as an ISO/IEC Standard; see 260 * <https://www.w3.org/TR/2003/REC-PNG-20031110/> 261 */ 262 263 #ifndef PNG_H 264 #define PNG_H 265 266 /* This is not the place to learn how to use libpng. The file libpng-manual.txt 267 * describes how to use libpng, and the file example.c summarizes it 268 * with some code on which to build. This file is useful for looking 269 * at the actual function definitions and structure components. If that 270 * file has been stripped from your copy of libpng, you can find it at 271 * <http://www.libpng.org/pub/png/libpng-manual.txt> 272 * 273 * If you just need to read a PNG file and don't want to read the documentation 274 * skip to the end of this file and read the section entitled 'simplified API'. 275 */ 276 277 /* Version information for png.h - this should match the version in png.c */ 278 #define PNG_LIBPNG_VER_STRING "1.6.44" 279 #define PNG_HEADER_VERSION_STRING " libpng version " PNG_LIBPNG_VER_STRING "\n" 280 281 /* The versions of shared library builds should stay in sync, going forward */ 282 #define PNG_LIBPNG_VER_SHAREDLIB 16 283 #define PNG_LIBPNG_VER_SONUM PNG_LIBPNG_VER_SHAREDLIB /* [Deprecated] */ 284 #define PNG_LIBPNG_VER_DLLNUM PNG_LIBPNG_VER_SHAREDLIB /* [Deprecated] */ 285 286 /* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */ 287 #define PNG_LIBPNG_VER_MAJOR 1 288 #define PNG_LIBPNG_VER_MINOR 6 289 #define PNG_LIBPNG_VER_RELEASE 44 290 291 /* This should be zero for a public release, or non-zero for a 292 * development version. 293 */ 294 #define PNG_LIBPNG_VER_BUILD 0 295 296 /* Release Status */ 297 #define PNG_LIBPNG_BUILD_ALPHA 1 298 #define PNG_LIBPNG_BUILD_BETA 2 299 #define PNG_LIBPNG_BUILD_RC 3 300 #define PNG_LIBPNG_BUILD_STABLE 4 301 #define PNG_LIBPNG_BUILD_RELEASE_STATUS_MASK 7 302 303 /* Release-Specific Flags */ 304 #define PNG_LIBPNG_BUILD_PATCH 8 /* Can be OR'ed with 305 PNG_LIBPNG_BUILD_STABLE only */ 306 #define PNG_LIBPNG_BUILD_PRIVATE 16 /* Cannot be OR'ed with 307 PNG_LIBPNG_BUILD_SPECIAL */ 308 #define PNG_LIBPNG_BUILD_SPECIAL 32 /* Cannot be OR'ed with 309 PNG_LIBPNG_BUILD_PRIVATE */ 310 311 #define PNG_LIBPNG_BUILD_BASE_TYPE PNG_LIBPNG_BUILD_STABLE 312 313 /* Careful here. At one time, Guy wanted to use 082, but that 314 * would be octal. We must not include leading zeros. 315 * Versions 0.7 through 1.0.0 were in the range 0 to 100 here 316 * (only version 1.0.0 was mis-numbered 100 instead of 10000). 317 * From version 1.0.1 it is: 318 * XXYYZZ, where XX=major, YY=minor, ZZ=release 319 */ 320 #define PNG_LIBPNG_VER 10644 /* 1.6.44 */ 321 322 /* Library configuration: these options cannot be changed after 323 * the library has been built. 324 */ 325 #ifndef PNGLCONF_H 326 /* If pnglibconf.h is missing, you can 327 * copy scripts/pnglibconf.h.prebuilt to pnglibconf.h 328 */ 329 # include "pnglibconf.h" 330 #endif 331 332 #ifndef PNG_VERSION_INFO_ONLY 333 /* Machine specific configuration. */ 334 # include "pngconf.h" 335 #endif 336 337 /* 338 * Added at libpng-1.2.8 339 * 340 * Ref MSDN: Private as priority over Special 341 * VS_FF_PRIVATEBUILD File *was not* built using standard release 342 * procedures. If this value is given, the StringFileInfo block must 343 * contain a PrivateBuild string. 344 * 345 * VS_FF_SPECIALBUILD File *was* built by the original company using 346 * standard release procedures but is a variation of the standard 347 * file of the same version number. If this value is given, the 348 * StringFileInfo block must contain a SpecialBuild string. 349 */ 350 351 #ifdef PNG_USER_PRIVATEBUILD /* From pnglibconf.h */ 352 # define PNG_LIBPNG_BUILD_TYPE \ 353 (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_PRIVATE) 354 #else 355 # ifdef PNG_LIBPNG_SPECIALBUILD 356 # define PNG_LIBPNG_BUILD_TYPE \ 357 (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_SPECIAL) 358 # else 359 # define PNG_LIBPNG_BUILD_TYPE (PNG_LIBPNG_BUILD_BASE_TYPE) 360 # endif 361 #endif 362 363 #ifndef PNG_VERSION_INFO_ONLY 364 365 /* Inhibit C++ name-mangling for libpng functions but not for system calls. */ 366 #ifdef __cplusplus 367 extern "C" { 368 #endif /* __cplusplus */ 369 370 /* Version information for C files, stored in png.c. This had better match 371 * the version above. 372 */ 373 #define png_libpng_ver png_get_header_ver(NULL) 374 375 /* This file is arranged in several sections: 376 * 377 * 1. [omitted] 378 * 2. Any configuration options that can be specified by for the application 379 * code when it is built. (Build time configuration is in pnglibconf.h) 380 * 3. Type definitions (base types are defined in pngconf.h), structure 381 * definitions. 382 * 4. Exported library functions. 383 * 5. Simplified API. 384 * 6. Implementation options. 385 * 386 * The library source code has additional files (principally pngpriv.h) that 387 * allow configuration of the library. 388 */ 389 390 /* Section 1: [omitted] */ 391 392 /* Section 2: run time configuration 393 * See pnglibconf.h for build time configuration 394 * 395 * Run time configuration allows the application to choose between 396 * implementations of certain arithmetic APIs. The default is set 397 * at build time and recorded in pnglibconf.h, but it is safe to 398 * override these (and only these) settings. Note that this won't 399 * change what the library does, only application code, and the 400 * settings can (and probably should) be made on a per-file basis 401 * by setting the #defines before including png.h 402 * 403 * Use macros to read integers from PNG data or use the exported 404 * functions? 405 * PNG_USE_READ_MACROS: use the macros (see below) Note that 406 * the macros evaluate their argument multiple times. 407 * PNG_NO_USE_READ_MACROS: call the relevant library function. 408 * 409 * Use the alternative algorithm for compositing alpha samples that 410 * does not use division? 411 * PNG_READ_COMPOSITE_NODIV_SUPPORTED: use the 'no division' 412 * algorithm. 413 * PNG_NO_READ_COMPOSITE_NODIV: use the 'division' algorithm. 414 * 415 * How to handle benign errors if PNG_ALLOW_BENIGN_ERRORS is 416 * false? 417 * PNG_ALLOW_BENIGN_ERRORS: map calls to the benign error 418 * APIs to png_warning. 419 * Otherwise the calls are mapped to png_error. 420 */ 421 422 /* Section 3: type definitions, including structures and compile time 423 * constants. 424 * See pngconf.h for base types that vary by machine/system 425 */ 426 427 /* This triggers a compiler error in png.c, if png.c and png.h 428 * do not agree upon the version number. 429 */ 430 typedef char* png_libpng_version_1_6_44; 431 432 /* Basic control structions. Read libpng-manual.txt or libpng.3 for more info. 433 * 434 * png_struct is the cache of information used while reading or writing a single 435 * PNG file. One of these is always required, although the simplified API 436 * (below) hides the creation and destruction of it. 437 */ 438 typedef struct png_struct_def png_struct; 439 typedef const png_struct * png_const_structp; 440 typedef png_struct * png_structp; 441 typedef png_struct * * png_structpp; 442 443 /* png_info contains information read from or to be written to a PNG file. One 444 * or more of these must exist while reading or creating a PNG file. The 445 * information is not used by libpng during read but is used to control what 446 * gets written when a PNG file is created. "png_get_" function calls read 447 * information during read and "png_set_" functions calls write information 448 * when creating a PNG. 449 * been moved into a separate header file that is not accessible to 450 * applications. Read libpng-manual.txt or libpng.3 for more info. 451 */ 452 typedef struct png_info_def png_info; 453 typedef png_info * png_infop; 454 typedef const png_info * png_const_infop; 455 typedef png_info * * png_infopp; 456 457 /* Types with names ending 'p' are pointer types. The corresponding types with 458 * names ending 'rp' are identical pointer types except that the pointer is 459 * marked 'restrict', which means that it is the only pointer to the object 460 * passed to the function. Applications should not use the 'restrict' types; 461 * it is always valid to pass 'p' to a pointer with a function argument of the 462 * corresponding 'rp' type. Different compilers have different rules with 463 * regard to type matching in the presence of 'restrict'. For backward 464 * compatibility libpng callbacks never have 'restrict' in their parameters and, 465 * consequentially, writing portable application code is extremely difficult if 466 * an attempt is made to use 'restrict'. 467 */ 468 typedef png_struct * PNG_RESTRICT png_structrp; 469 typedef const png_struct * PNG_RESTRICT png_const_structrp; 470 typedef png_info * PNG_RESTRICT png_inforp; 471 typedef const png_info * PNG_RESTRICT png_const_inforp; 472 473 /* Three color definitions. The order of the red, green, and blue, (and the 474 * exact size) is not important, although the size of the fields need to 475 * be png_byte or png_uint_16 (as defined below). 476 */ 477 typedef struct png_color_struct 478 { 479 png_byte red; 480 png_byte green; 481 png_byte blue; 482 } png_color; 483 typedef png_color * png_colorp; 484 typedef const png_color * png_const_colorp; 485 typedef png_color * * png_colorpp; 486 487 typedef struct png_color_16_struct 488 { 489 png_byte index; /* used for palette files */ 490 png_uint_16 red; /* for use in red green blue files */ 491 png_uint_16 green; 492 png_uint_16 blue; 493 png_uint_16 gray; /* for use in grayscale files */ 494 } png_color_16; 495 typedef png_color_16 * png_color_16p; 496 typedef const png_color_16 * png_const_color_16p; 497 typedef png_color_16 * * png_color_16pp; 498 499 typedef struct png_color_8_struct 500 { 501 png_byte red; /* for use in red green blue files */ 502 png_byte green; 503 png_byte blue; 504 png_byte gray; /* for use in grayscale files */ 505 png_byte alpha; /* for alpha channel files */ 506 } png_color_8; 507 typedef png_color_8 * png_color_8p; 508 typedef const png_color_8 * png_const_color_8p; 509 typedef png_color_8 * * png_color_8pp; 510 511 /* 512 * The following two structures are used for the in-core representation 513 * of sPLT chunks. 514 */ 515 typedef struct png_sPLT_entry_struct 516 { 517 png_uint_16 red; 518 png_uint_16 green; 519 png_uint_16 blue; 520 png_uint_16 alpha; 521 png_uint_16 frequency; 522 } png_sPLT_entry; 523 typedef png_sPLT_entry * png_sPLT_entryp; 524 typedef const png_sPLT_entry * png_const_sPLT_entryp; 525 typedef png_sPLT_entry * * png_sPLT_entrypp; 526 527 /* When the depth of the sPLT palette is 8 bits, the color and alpha samples 528 * occupy the LSB of their respective members, and the MSB of each member 529 * is zero-filled. The frequency member always occupies the full 16 bits. 530 */ 531 532 typedef struct png_sPLT_struct 533 { 534 png_charp name; /* palette name */ 535 png_byte depth; /* depth of palette samples */ 536 png_sPLT_entryp entries; /* palette entries */ 537 png_int_32 nentries; /* number of palette entries */ 538 } png_sPLT_t; 539 typedef png_sPLT_t * png_sPLT_tp; 540 typedef const png_sPLT_t * png_const_sPLT_tp; 541 typedef png_sPLT_t * * png_sPLT_tpp; 542 543 #ifdef PNG_TEXT_SUPPORTED 544 /* png_text holds the contents of a text/ztxt/itxt chunk in a PNG file, 545 * and whether that contents is compressed or not. The "key" field 546 * points to a regular zero-terminated C string. The "text" fields can be a 547 * regular C string, an empty string, or a NULL pointer. 548 * However, the structure returned by png_get_text() will always contain 549 * the "text" field as a regular zero-terminated C string (possibly 550 * empty), never a NULL pointer, so it can be safely used in printf() and 551 * other string-handling functions. Note that the "itxt_length", "lang", and 552 * "lang_key" members of the structure only exist when the library is built 553 * with iTXt chunk support. Prior to libpng-1.4.0 the library was built by 554 * default without iTXt support. Also note that when iTXt *is* supported, 555 * the "lang" and "lang_key" fields contain NULL pointers when the 556 * "compression" field contains * PNG_TEXT_COMPRESSION_NONE or 557 * PNG_TEXT_COMPRESSION_zTXt. Note that the "compression value" is not the 558 * same as what appears in the PNG tEXt/zTXt/iTXt chunk's "compression flag" 559 * which is always 0 or 1, or its "compression method" which is always 0. 560 */ 561 typedef struct png_text_struct 562 { 563 int compression; /* compression value: 564 -1: tEXt, none 565 0: zTXt, deflate 566 1: iTXt, none 567 2: iTXt, deflate */ 568 png_charp key; /* keyword, 1-79 character description of "text" */ 569 png_charp text; /* comment, may be an empty string (ie "") 570 or a NULL pointer */ 571 size_t text_length; /* length of the text string */ 572 size_t itxt_length; /* length of the itxt string */ 573 png_charp lang; /* language code, 0-79 characters 574 or a NULL pointer */ 575 png_charp lang_key; /* keyword translated UTF-8 string, 0 or more 576 chars or a NULL pointer */ 577 } png_text; 578 typedef png_text * png_textp; 579 typedef const png_text * png_const_textp; 580 typedef png_text * * png_textpp; 581 #endif 582 583 /* Supported compression types for text in PNG files (tEXt, and zTXt). 584 * The values of the PNG_TEXT_COMPRESSION_ defines should NOT be changed. */ 585 #define PNG_TEXT_COMPRESSION_NONE_WR -3 586 #define PNG_TEXT_COMPRESSION_zTXt_WR -2 587 #define PNG_TEXT_COMPRESSION_NONE -1 588 #define PNG_TEXT_COMPRESSION_zTXt 0 589 #define PNG_ITXT_COMPRESSION_NONE 1 590 #define PNG_ITXT_COMPRESSION_zTXt 2 591 #define PNG_TEXT_COMPRESSION_LAST 3 /* Not a valid value */ 592 593 /* png_time is a way to hold the time in an machine independent way. 594 * Two conversions are provided, both from time_t and struct tm. There 595 * is no portable way to convert to either of these structures, as far 596 * as I know. If you know of a portable way, send it to me. As a side 597 * note - PNG has always been Year 2000 compliant! 598 */ 599 typedef struct png_time_struct 600 { 601 png_uint_16 year; /* full year, as in, 1995 */ 602 png_byte month; /* month of year, 1 - 12 */ 603 png_byte day; /* day of month, 1 - 31 */ 604 png_byte hour; /* hour of day, 0 - 23 */ 605 png_byte minute; /* minute of hour, 0 - 59 */ 606 png_byte second; /* second of minute, 0 - 60 (for leap seconds) */ 607 } png_time; 608 typedef png_time * png_timep; 609 typedef const png_time * png_const_timep; 610 typedef png_time * * png_timepp; 611 612 #if defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED) ||\ 613 defined(PNG_USER_CHUNKS_SUPPORTED) 614 /* png_unknown_chunk is a structure to hold queued chunks for which there is 615 * no specific support. The idea is that we can use this to queue 616 * up private chunks for output even though the library doesn't actually 617 * know about their semantics. 618 * 619 * The data in the structure is set by libpng on read and used on write. 620 */ 621 typedef struct png_unknown_chunk_t 622 { 623 png_byte name[5]; /* Textual chunk name with '\0' terminator */ 624 png_byte *data; /* Data, should not be modified on read! */ 625 size_t size; 626 627 /* On write 'location' must be set using the flag values listed below. 628 * Notice that on read it is set by libpng however the values stored have 629 * more bits set than are listed below. Always treat the value as a 630 * bitmask. On write set only one bit - setting multiple bits may cause the 631 * chunk to be written in multiple places. 632 */ 633 png_byte location; /* mode of operation at read time */ 634 } 635 png_unknown_chunk; 636 637 typedef png_unknown_chunk * png_unknown_chunkp; 638 typedef const png_unknown_chunk * png_const_unknown_chunkp; 639 typedef png_unknown_chunk * * png_unknown_chunkpp; 640 #endif 641 642 /* Flag values for the unknown chunk location byte. */ 643 #define PNG_HAVE_IHDR 0x01 644 #define PNG_HAVE_PLTE 0x02 645 #define PNG_AFTER_IDAT 0x08 646 647 /* Maximum positive integer used in PNG is (2^31)-1 */ 648 #define PNG_UINT_31_MAX ((png_uint_32)0x7fffffffL) 649 #define PNG_UINT_32_MAX ((png_uint_32)(-1)) 650 #define PNG_SIZE_MAX ((size_t)(-1)) 651 652 /* These are constants for fixed point values encoded in the 653 * PNG specification manner (x100000) 654 */ 655 #define PNG_FP_1 100000 656 #define PNG_FP_HALF 50000 657 #define PNG_FP_MAX ((png_fixed_point)0x7fffffffL) 658 #define PNG_FP_MIN (-PNG_FP_MAX) 659 660 /* These describe the color_type field in png_info. */ 661 /* color type masks */ 662 #define PNG_COLOR_MASK_PALETTE 1 663 #define PNG_COLOR_MASK_COLOR 2 664 #define PNG_COLOR_MASK_ALPHA 4 665 666 /* color types. Note that not all combinations are legal */ 667 #define PNG_COLOR_TYPE_GRAY 0 668 #define PNG_COLOR_TYPE_PALETTE (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE) 669 #define PNG_COLOR_TYPE_RGB (PNG_COLOR_MASK_COLOR) 670 #define PNG_COLOR_TYPE_RGB_ALPHA (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_ALPHA) 671 #define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA) 672 /* aliases */ 673 #define PNG_COLOR_TYPE_RGBA PNG_COLOR_TYPE_RGB_ALPHA 674 #define PNG_COLOR_TYPE_GA PNG_COLOR_TYPE_GRAY_ALPHA 675 676 /* This is for compression type. PNG 1.0-1.2 only define the single type. */ 677 #define PNG_COMPRESSION_TYPE_BASE 0 /* Deflate method 8, 32K window */ 678 #define PNG_COMPRESSION_TYPE_DEFAULT PNG_COMPRESSION_TYPE_BASE 679 680 /* This is for filter type. PNG 1.0-1.2 only define the single type. */ 681 #define PNG_FILTER_TYPE_BASE 0 /* Single row per-byte filtering */ 682 #define PNG_INTRAPIXEL_DIFFERENCING 64 /* Used only in MNG datastreams */ 683 #define PNG_FILTER_TYPE_DEFAULT PNG_FILTER_TYPE_BASE 684 685 /* These are for the interlacing type. These values should NOT be changed. */ 686 #define PNG_INTERLACE_NONE 0 /* Non-interlaced image */ 687 #define PNG_INTERLACE_ADAM7 1 /* Adam7 interlacing */ 688 #define PNG_INTERLACE_LAST 2 /* Not a valid value */ 689 690 /* These are for the oFFs chunk. These values should NOT be changed. */ 691 #define PNG_OFFSET_PIXEL 0 /* Offset in pixels */ 692 #define PNG_OFFSET_MICROMETER 1 /* Offset in micrometers (1/10^6 meter) */ 693 #define PNG_OFFSET_LAST 2 /* Not a valid value */ 694 695 /* These are for the pCAL chunk. These values should NOT be changed. */ 696 #define PNG_EQUATION_LINEAR 0 /* Linear transformation */ 697 #define PNG_EQUATION_BASE_E 1 /* Exponential base e transform */ 698 #define PNG_EQUATION_ARBITRARY 2 /* Arbitrary base exponential transform */ 699 #define PNG_EQUATION_HYPERBOLIC 3 /* Hyperbolic sine transformation */ 700 #define PNG_EQUATION_LAST 4 /* Not a valid value */ 701 702 /* These are for the sCAL chunk. These values should NOT be changed. */ 703 #define PNG_SCALE_UNKNOWN 0 /* unknown unit (image scale) */ 704 #define PNG_SCALE_METER 1 /* meters per pixel */ 705 #define PNG_SCALE_RADIAN 2 /* radians per pixel */ 706 #define PNG_SCALE_LAST 3 /* Not a valid value */ 707 708 /* These are for the pHYs chunk. These values should NOT be changed. */ 709 #define PNG_RESOLUTION_UNKNOWN 0 /* pixels/unknown unit (aspect ratio) */ 710 #define PNG_RESOLUTION_METER 1 /* pixels/meter */ 711 #define PNG_RESOLUTION_LAST 2 /* Not a valid value */ 712 713 /* These are for the sRGB chunk. These values should NOT be changed. */ 714 #define PNG_sRGB_INTENT_PERCEPTUAL 0 715 #define PNG_sRGB_INTENT_RELATIVE 1 716 #define PNG_sRGB_INTENT_SATURATION 2 717 #define PNG_sRGB_INTENT_ABSOLUTE 3 718 #define PNG_sRGB_INTENT_LAST 4 /* Not a valid value */ 719 720 /* This is for text chunks */ 721 #define PNG_KEYWORD_MAX_LENGTH 79 722 723 /* Maximum number of entries in PLTE/sPLT/tRNS arrays */ 724 #define PNG_MAX_PALETTE_LENGTH 256 725 726 /* These determine if an ancillary chunk's data has been successfully read 727 * from the PNG header, or if the application has filled in the corresponding 728 * data in the info_struct to be written into the output file. The values 729 * of the PNG_INFO_<chunk> defines should NOT be changed. 730 */ 731 #define PNG_INFO_gAMA 0x0001U 732 #define PNG_INFO_sBIT 0x0002U 733 #define PNG_INFO_cHRM 0x0004U 734 #define PNG_INFO_PLTE 0x0008U 735 #define PNG_INFO_tRNS 0x0010U 736 #define PNG_INFO_bKGD 0x0020U 737 #define PNG_INFO_hIST 0x0040U 738 #define PNG_INFO_pHYs 0x0080U 739 #define PNG_INFO_oFFs 0x0100U 740 #define PNG_INFO_tIME 0x0200U 741 #define PNG_INFO_pCAL 0x0400U 742 #define PNG_INFO_sRGB 0x0800U /* GR-P, 0.96a */ 743 #define PNG_INFO_iCCP 0x1000U /* ESR, 1.0.6 */ 744 #define PNG_INFO_sPLT 0x2000U /* ESR, 1.0.6 */ 745 #define PNG_INFO_sCAL 0x4000U /* ESR, 1.0.6 */ 746 #define PNG_INFO_IDAT 0x8000U /* ESR, 1.0.6 */ 747 #define PNG_INFO_eXIf 0x10000U /* GR-P, 1.6.31 */ 748 749 /* This is used for the transformation routines, as some of them 750 * change these values for the row. It also should enable using 751 * the routines for other purposes. 752 */ 753 typedef struct png_row_info_struct 754 { 755 png_uint_32 width; /* width of row */ 756 size_t rowbytes; /* number of bytes in row */ 757 png_byte color_type; /* color type of row */ 758 png_byte bit_depth; /* bit depth of row */ 759 png_byte channels; /* number of channels (1, 2, 3, or 4) */ 760 png_byte pixel_depth; /* bits per pixel (depth * channels) */ 761 } png_row_info; 762 763 typedef png_row_info * png_row_infop; 764 typedef png_row_info * * png_row_infopp; 765 766 /* These are the function types for the I/O functions and for the functions 767 * that allow the user to override the default I/O functions with his or her 768 * own. The png_error_ptr type should match that of user-supplied warning 769 * and error functions, while the png_rw_ptr type should match that of the 770 * user read/write data functions. Note that the 'write' function must not 771 * modify the buffer it is passed. The 'read' function, on the other hand, is 772 * expected to return the read data in the buffer. 773 */ 774 typedef PNG_CALLBACK(void, *png_error_ptr, (png_structp, png_const_charp)); 775 typedef PNG_CALLBACK(void, *png_rw_ptr, (png_structp, png_bytep, size_t)); 776 typedef PNG_CALLBACK(void, *png_flush_ptr, (png_structp)); 777 typedef PNG_CALLBACK(void, *png_read_status_ptr, (png_structp, png_uint_32, 778 int)); 779 typedef PNG_CALLBACK(void, *png_write_status_ptr, (png_structp, png_uint_32, 780 int)); 781 782 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED 783 typedef PNG_CALLBACK(void, *png_progressive_info_ptr, (png_structp, png_infop)); 784 typedef PNG_CALLBACK(void, *png_progressive_end_ptr, (png_structp, png_infop)); 785 786 /* The following callback receives png_uint_32 row_number, int pass for the 787 * png_bytep data of the row. When transforming an interlaced image the 788 * row number is the row number within the sub-image of the interlace pass, so 789 * the value will increase to the height of the sub-image (not the full image) 790 * then reset to 0 for the next pass. 791 * 792 * Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to 793 * find the output pixel (x,y) given an interlaced sub-image pixel 794 * (row,col,pass). (See below for these macros.) 795 */ 796 typedef PNG_CALLBACK(void, *png_progressive_row_ptr, (png_structp, png_bytep, 797 png_uint_32, int)); 798 #endif 799 800 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \ 801 defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) 802 typedef PNG_CALLBACK(void, *png_user_transform_ptr, (png_structp, png_row_infop, 803 png_bytep)); 804 #endif 805 806 #ifdef PNG_USER_CHUNKS_SUPPORTED 807 typedef PNG_CALLBACK(int, *png_user_chunk_ptr, (png_structp, 808 png_unknown_chunkp)); 809 #endif 810 #ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED 811 /* not used anywhere */ 812 /* typedef PNG_CALLBACK(void, *png_unknown_chunk_ptr, (png_structp)); */ 813 #endif 814 815 #ifdef PNG_SETJMP_SUPPORTED 816 /* This must match the function definition in <setjmp.h>, and the application 817 * must include this before png.h to obtain the definition of jmp_buf. The 818 * function is required to be PNG_NORETURN, but this is not checked. If the 819 * function does return the application will crash via an abort() or similar 820 * system level call. 821 * 822 * If you get a warning here while building the library you may need to make 823 * changes to ensure that pnglibconf.h records the calling convention used by 824 * your compiler. This may be very difficult - try using a different compiler 825 * to build the library! 826 */ 827 PNG_FUNCTION(void, (PNGCAPI *png_longjmp_ptr), (jmp_buf, int), typedef); 828 #endif 829 830 /* Transform masks for the high-level interface */ 831 #define PNG_TRANSFORM_IDENTITY 0x0000 /* read and write */ 832 #define PNG_TRANSFORM_STRIP_16 0x0001 /* read only */ 833 #define PNG_TRANSFORM_STRIP_ALPHA 0x0002 /* read only */ 834 #define PNG_TRANSFORM_PACKING 0x0004 /* read and write */ 835 #define PNG_TRANSFORM_PACKSWAP 0x0008 /* read and write */ 836 #define PNG_TRANSFORM_EXPAND 0x0010 /* read only */ 837 #define PNG_TRANSFORM_INVERT_MONO 0x0020 /* read and write */ 838 #define PNG_TRANSFORM_SHIFT 0x0040 /* read and write */ 839 #define PNG_TRANSFORM_BGR 0x0080 /* read and write */ 840 #define PNG_TRANSFORM_SWAP_ALPHA 0x0100 /* read and write */ 841 #define PNG_TRANSFORM_SWAP_ENDIAN 0x0200 /* read and write */ 842 #define PNG_TRANSFORM_INVERT_ALPHA 0x0400 /* read and write */ 843 #define PNG_TRANSFORM_STRIP_FILLER 0x0800 /* write only */ 844 /* Added to libpng-1.2.34 */ 845 #define PNG_TRANSFORM_STRIP_FILLER_BEFORE PNG_TRANSFORM_STRIP_FILLER 846 #define PNG_TRANSFORM_STRIP_FILLER_AFTER 0x1000 /* write only */ 847 /* Added to libpng-1.4.0 */ 848 #define PNG_TRANSFORM_GRAY_TO_RGB 0x2000 /* read only */ 849 /* Added to libpng-1.5.4 */ 850 #define PNG_TRANSFORM_EXPAND_16 0x4000 /* read only */ 851 #if ~0U > 0xffffU /* or else this might break on a 16-bit machine */ 852 #define PNG_TRANSFORM_SCALE_16 0x8000 /* read only */ 853 #endif 854 855 /* Flags for MNG supported features */ 856 #define PNG_FLAG_MNG_EMPTY_PLTE 0x01 857 #define PNG_FLAG_MNG_FILTER_64 0x04 858 #define PNG_ALL_MNG_FEATURES 0x05 859 860 /* NOTE: prior to 1.5 these functions had no 'API' style declaration, 861 * this allowed the zlib default functions to be used on Windows 862 * platforms. In 1.5 the zlib default malloc (which just calls malloc and 863 * ignores the first argument) should be completely compatible with the 864 * following. 865 */ 866 typedef PNG_CALLBACK(png_voidp, *png_malloc_ptr, (png_structp, 867 png_alloc_size_t)); 868 typedef PNG_CALLBACK(void, *png_free_ptr, (png_structp, png_voidp)); 869 870 /* Section 4: exported functions 871 * Here are the function definitions most commonly used. This is not 872 * the place to find out how to use libpng. See libpng-manual.txt for the 873 * full explanation, see example.c for the summary. This just provides 874 * a simple one line description of the use of each function. 875 * 876 * The PNG_EXPORT() and PNG_EXPORTA() macros used below are defined in 877 * pngconf.h and in the *.dfn files in the scripts directory. 878 * 879 * PNG_EXPORT(ordinal, type, name, (args)); 880 * 881 * ordinal: ordinal that is used while building 882 * *.def files. The ordinal value is only 883 * relevant when preprocessing png.h with 884 * the *.dfn files for building symbol table 885 * entries, and are removed by pngconf.h. 886 * type: return type of the function 887 * name: function name 888 * args: function arguments, with types 889 * 890 * When we wish to append attributes to a function prototype we use 891 * the PNG_EXPORTA() macro instead. 892 * 893 * PNG_EXPORTA(ordinal, type, name, (args), attributes); 894 * 895 * ordinal, type, name, and args: same as in PNG_EXPORT(). 896 * attributes: function attributes 897 */ 898 899 /* Returns the version number of the library */ 900 PNG_EXPORT(1, png_uint_32, png_access_version_number, (void)); 901 902 /* Tell lib we have already handled the first <num_bytes> magic bytes. 903 * Handling more than 8 bytes from the beginning of the file is an error. 904 */ 905 PNG_EXPORT(2, void, png_set_sig_bytes, (png_structrp png_ptr, int num_bytes)); 906 907 /* Check sig[start] through sig[start + num_to_check - 1] to see if it's a 908 * PNG file. Returns zero if the supplied bytes match the 8-byte PNG 909 * signature, and non-zero otherwise. Having num_to_check == 0 or 910 * start > 7 will always fail (i.e. return non-zero). 911 */ 912 PNG_EXPORT(3, int, png_sig_cmp, (png_const_bytep sig, size_t start, 913 size_t num_to_check)); 914 915 /* Simple signature checking function. This is the same as calling 916 * png_check_sig(sig, n) := (png_sig_cmp(sig, 0, n) == 0). 917 */ 918 #define png_check_sig(sig, n) (png_sig_cmp((sig), 0, (n)) == 0) /* DEPRECATED */ 919 920 /* Allocate and initialize png_ptr struct for reading, and any other memory. */ 921 PNG_EXPORTA(4, png_structp, png_create_read_struct, 922 (png_const_charp user_png_ver, png_voidp error_ptr, 923 png_error_ptr error_fn, png_error_ptr warn_fn), 924 PNG_ALLOCATED); 925 926 /* Allocate and initialize png_ptr struct for writing, and any other memory */ 927 PNG_EXPORTA(5, png_structp, png_create_write_struct, 928 (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn, 929 png_error_ptr warn_fn), 930 PNG_ALLOCATED); 931 932 PNG_EXPORT(6, size_t, png_get_compression_buffer_size, 933 (png_const_structrp png_ptr)); 934 935 PNG_EXPORT(7, void, png_set_compression_buffer_size, (png_structrp png_ptr, 936 size_t size)); 937 938 /* Moved from pngconf.h in 1.4.0 and modified to ensure setjmp/longjmp 939 * match up. 940 */ 941 #ifdef PNG_SETJMP_SUPPORTED 942 /* This function returns the jmp_buf built in to *png_ptr. It must be 943 * supplied with an appropriate 'longjmp' function to use on that jmp_buf 944 * unless the default error function is overridden in which case NULL is 945 * acceptable. The size of the jmp_buf is checked against the actual size 946 * allocated by the library - the call will return NULL on a mismatch 947 * indicating an ABI mismatch. 948 */ 949 PNG_EXPORT(8, jmp_buf*, png_set_longjmp_fn, (png_structrp png_ptr, 950 png_longjmp_ptr longjmp_fn, size_t jmp_buf_size)); 951 # define png_jmpbuf(png_ptr) \ 952 (*png_set_longjmp_fn((png_ptr), longjmp, (sizeof (jmp_buf)))) 953 #else 954 # define png_jmpbuf(png_ptr) \ 955 (LIBPNG_WAS_COMPILED_WITH__PNG_NO_SETJMP) 956 #endif 957 /* This function should be used by libpng applications in place of 958 * longjmp(png_ptr->jmpbuf, val). If longjmp_fn() has been set, it 959 * will use it; otherwise it will call PNG_ABORT(). This function was 960 * added in libpng-1.5.0. 961 */ 962 PNG_EXPORTA(9, void, png_longjmp, (png_const_structrp png_ptr, int val), 963 PNG_NORETURN); 964 965 #ifdef PNG_READ_SUPPORTED 966 /* Reset the compression stream */ 967 PNG_EXPORTA(10, int, png_reset_zstream, (png_structrp png_ptr), PNG_DEPRECATED); 968 #endif 969 970 /* New functions added in libpng-1.0.2 (not enabled by default until 1.2.0) */ 971 #ifdef PNG_USER_MEM_SUPPORTED 972 PNG_EXPORTA(11, png_structp, png_create_read_struct_2, 973 (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn, 974 png_error_ptr warn_fn, 975 png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn), 976 PNG_ALLOCATED); 977 PNG_EXPORTA(12, png_structp, png_create_write_struct_2, 978 (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn, 979 png_error_ptr warn_fn, 980 png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn), 981 PNG_ALLOCATED); 982 #endif 983 984 /* Write the PNG file signature. */ 985 PNG_EXPORT(13, void, png_write_sig, (png_structrp png_ptr)); 986 987 /* Write a PNG chunk - size, type, (optional) data, CRC. */ 988 PNG_EXPORT(14, void, png_write_chunk, (png_structrp png_ptr, png_const_bytep 989 chunk_name, png_const_bytep data, size_t length)); 990 991 /* Write the start of a PNG chunk - length and chunk name. */ 992 PNG_EXPORT(15, void, png_write_chunk_start, (png_structrp png_ptr, 993 png_const_bytep chunk_name, png_uint_32 length)); 994 995 /* Write the data of a PNG chunk started with png_write_chunk_start(). */ 996 PNG_EXPORT(16, void, png_write_chunk_data, (png_structrp png_ptr, 997 png_const_bytep data, size_t length)); 998 999 /* Finish a chunk started with png_write_chunk_start() (includes CRC). */ 1000 PNG_EXPORT(17, void, png_write_chunk_end, (png_structrp png_ptr)); 1001 1002 /* Allocate and initialize the info structure */ 1003 PNG_EXPORTA(18, png_infop, png_create_info_struct, (png_const_structrp png_ptr), 1004 PNG_ALLOCATED); 1005 1006 /* DEPRECATED: this function allowed init structures to be created using the 1007 * default allocation method (typically malloc). Use is deprecated in 1.6.0 and 1008 * the API will be removed in the future. 1009 */ 1010 PNG_EXPORTA(19, void, png_info_init_3, (png_infopp info_ptr, 1011 size_t png_info_struct_size), PNG_DEPRECATED); 1012 1013 /* Writes all the PNG information before the image. */ 1014 PNG_EXPORT(20, void, png_write_info_before_PLTE, 1015 (png_structrp png_ptr, png_const_inforp info_ptr)); 1016 PNG_EXPORT(21, void, png_write_info, 1017 (png_structrp png_ptr, png_const_inforp info_ptr)); 1018 1019 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED 1020 /* Read the information before the actual image data. */ 1021 PNG_EXPORT(22, void, png_read_info, 1022 (png_structrp png_ptr, png_inforp info_ptr)); 1023 #endif 1024 1025 #ifdef PNG_TIME_RFC1123_SUPPORTED 1026 /* Convert to a US string format: there is no localization support in this 1027 * routine. The original implementation used a 29 character buffer in 1028 * png_struct, this will be removed in future versions. 1029 */ 1030 #if PNG_LIBPNG_VER < 10700 1031 /* To do: remove this from libpng17 (and from libpng17/png.c and pngstruct.h) */ 1032 PNG_EXPORTA(23, png_const_charp, png_convert_to_rfc1123, (png_structrp png_ptr, 1033 png_const_timep ptime),PNG_DEPRECATED); 1034 #endif 1035 PNG_EXPORT(241, int, png_convert_to_rfc1123_buffer, (char out[29], 1036 png_const_timep ptime)); 1037 #endif 1038 1039 #ifdef PNG_CONVERT_tIME_SUPPORTED 1040 /* Convert from a struct tm to png_time */ 1041 PNG_EXPORT(24, void, png_convert_from_struct_tm, (png_timep ptime, 1042 const struct tm * ttime)); 1043 1044 /* Convert from time_t to png_time. Uses gmtime() */ 1045 PNG_EXPORT(25, void, png_convert_from_time_t, (png_timep ptime, time_t ttime)); 1046 #endif /* CONVERT_tIME */ 1047 1048 #ifdef PNG_READ_EXPAND_SUPPORTED 1049 /* Expand data to 24-bit RGB, or 8-bit grayscale, with alpha if available. */ 1050 PNG_EXPORT(26, void, png_set_expand, (png_structrp png_ptr)); 1051 PNG_EXPORT(27, void, png_set_expand_gray_1_2_4_to_8, (png_structrp png_ptr)); 1052 PNG_EXPORT(28, void, png_set_palette_to_rgb, (png_structrp png_ptr)); 1053 PNG_EXPORT(29, void, png_set_tRNS_to_alpha, (png_structrp png_ptr)); 1054 #endif 1055 1056 #ifdef PNG_READ_EXPAND_16_SUPPORTED 1057 /* Expand to 16-bit channels, forces conversion of palette to RGB and expansion 1058 * of a tRNS chunk if present. 1059 */ 1060 PNG_EXPORT(221, void, png_set_expand_16, (png_structrp png_ptr)); 1061 #endif 1062 1063 #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED) 1064 /* Use blue, green, red order for pixels. */ 1065 PNG_EXPORT(30, void, png_set_bgr, (png_structrp png_ptr)); 1066 #endif 1067 1068 #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED 1069 /* Expand the grayscale to 24-bit RGB if necessary. */ 1070 PNG_EXPORT(31, void, png_set_gray_to_rgb, (png_structrp png_ptr)); 1071 #endif 1072 1073 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED 1074 /* Reduce RGB to grayscale. */ 1075 #define PNG_ERROR_ACTION_NONE 1 1076 #define PNG_ERROR_ACTION_WARN 2 1077 #define PNG_ERROR_ACTION_ERROR 3 1078 #define PNG_RGB_TO_GRAY_DEFAULT (-1)/*for red/green coefficients*/ 1079 1080 PNG_FP_EXPORT(32, void, png_set_rgb_to_gray, (png_structrp png_ptr, 1081 int error_action, double red, double green)) 1082 PNG_FIXED_EXPORT(33, void, png_set_rgb_to_gray_fixed, (png_structrp png_ptr, 1083 int error_action, png_fixed_point red, png_fixed_point green)) 1084 1085 PNG_EXPORT(34, png_byte, png_get_rgb_to_gray_status, (png_const_structrp 1086 png_ptr)); 1087 #endif 1088 1089 #ifdef PNG_BUILD_GRAYSCALE_PALETTE_SUPPORTED 1090 PNG_EXPORT(35, void, png_build_grayscale_palette, (int bit_depth, 1091 png_colorp palette)); 1092 #endif 1093 1094 #ifdef PNG_READ_ALPHA_MODE_SUPPORTED 1095 /* How the alpha channel is interpreted - this affects how the color channels 1096 * of a PNG file are returned to the calling application when an alpha channel, 1097 * or a tRNS chunk in a palette file, is present. 1098 * 1099 * This has no effect on the way pixels are written into a PNG output 1100 * datastream. The color samples in a PNG datastream are never premultiplied 1101 * with the alpha samples. 1102 * 1103 * The default is to return data according to the PNG specification: the alpha 1104 * channel is a linear measure of the contribution of the pixel to the 1105 * corresponding composited pixel, and the color channels are unassociated 1106 * (not premultiplied). The gamma encoded color channels must be scaled 1107 * according to the contribution and to do this it is necessary to undo 1108 * the encoding, scale the color values, perform the composition and re-encode 1109 * the values. This is the 'PNG' mode. 1110 * 1111 * The alternative is to 'associate' the alpha with the color information by 1112 * storing color channel values that have been scaled by the alpha. 1113 * image. These are the 'STANDARD', 'ASSOCIATED' or 'PREMULTIPLIED' modes 1114 * (the latter being the two common names for associated alpha color channels). 1115 * 1116 * For the 'OPTIMIZED' mode, a pixel is treated as opaque only if the alpha 1117 * value is equal to the maximum value. 1118 * 1119 * The final choice is to gamma encode the alpha channel as well. This is 1120 * broken because, in practice, no implementation that uses this choice 1121 * correctly undoes the encoding before handling alpha composition. Use this 1122 * choice only if other serious errors in the software or hardware you use 1123 * mandate it; the typical serious error is for dark halos to appear around 1124 * opaque areas of the composited PNG image because of arithmetic overflow. 1125 * 1126 * The API function png_set_alpha_mode specifies which of these choices to use 1127 * with an enumerated 'mode' value and the gamma of the required output: 1128 */ 1129 #define PNG_ALPHA_PNG 0 /* according to the PNG standard */ 1130 #define PNG_ALPHA_STANDARD 1 /* according to Porter/Duff */ 1131 #define PNG_ALPHA_ASSOCIATED 1 /* as above; this is the normal practice */ 1132 #define PNG_ALPHA_PREMULTIPLIED 1 /* as above */ 1133 #define PNG_ALPHA_OPTIMIZED 2 /* 'PNG' for opaque pixels, else 'STANDARD' */ 1134 #define PNG_ALPHA_BROKEN 3 /* the alpha channel is gamma encoded */ 1135 1136 PNG_FP_EXPORT(227, void, png_set_alpha_mode, (png_structrp png_ptr, int mode, 1137 double output_gamma)) 1138 PNG_FIXED_EXPORT(228, void, png_set_alpha_mode_fixed, (png_structrp png_ptr, 1139 int mode, png_fixed_point output_gamma)) 1140 #endif 1141 1142 #if defined(PNG_GAMMA_SUPPORTED) || defined(PNG_READ_ALPHA_MODE_SUPPORTED) 1143 /* The output_gamma value is a screen gamma in libpng terminology: it expresses 1144 * how to decode the output values, not how they are encoded. 1145 */ 1146 #define PNG_DEFAULT_sRGB -1 /* sRGB gamma and color space */ 1147 #define PNG_GAMMA_MAC_18 -2 /* Old Mac '1.8' gamma and color space */ 1148 #define PNG_GAMMA_sRGB 220000 /* Television standards--matches sRGB gamma */ 1149 #define PNG_GAMMA_LINEAR PNG_FP_1 /* Linear */ 1150 #endif 1151 1152 /* The following are examples of calls to png_set_alpha_mode to achieve the 1153 * required overall gamma correction and, where necessary, alpha 1154 * premultiplication. 1155 * 1156 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB); 1157 * This is the default libpng handling of the alpha channel - it is not 1158 * pre-multiplied into the color components. In addition the call states 1159 * that the output is for a sRGB system and causes all PNG files without gAMA 1160 * chunks to be assumed to be encoded using sRGB. 1161 * 1162 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC); 1163 * In this case the output is assumed to be something like an sRGB conformant 1164 * display preceded by a power-law lookup table of power 1.45. This is how 1165 * early Mac systems behaved. 1166 * 1167 * png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_GAMMA_LINEAR); 1168 * This is the classic Jim Blinn approach and will work in academic 1169 * environments where everything is done by the book. It has the shortcoming 1170 * of assuming that input PNG data with no gamma information is linear - this 1171 * is unlikely to be correct unless the PNG files where generated locally. 1172 * Most of the time the output precision will be so low as to show 1173 * significant banding in dark areas of the image. 1174 * 1175 * png_set_expand_16(pp); 1176 * png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_DEFAULT_sRGB); 1177 * This is a somewhat more realistic Jim Blinn inspired approach. PNG files 1178 * are assumed to have the sRGB encoding if not marked with a gamma value and 1179 * the output is always 16 bits per component. This permits accurate scaling 1180 * and processing of the data. If you know that your input PNG files were 1181 * generated locally you might need to replace PNG_DEFAULT_sRGB with the 1182 * correct value for your system. 1183 * 1184 * png_set_alpha_mode(pp, PNG_ALPHA_OPTIMIZED, PNG_DEFAULT_sRGB); 1185 * If you just need to composite the PNG image onto an existing background 1186 * and if you control the code that does this you can use the optimization 1187 * setting. In this case you just copy completely opaque pixels to the 1188 * output. For pixels that are not completely transparent (you just skip 1189 * those) you do the composition math using png_composite or png_composite_16 1190 * below then encode the resultant 8-bit or 16-bit values to match the output 1191 * encoding. 1192 * 1193 * Other cases 1194 * If neither the PNG nor the standard linear encoding work for you because 1195 * of the software or hardware you use then you have a big problem. The PNG 1196 * case will probably result in halos around the image. The linear encoding 1197 * will probably result in a washed out, too bright, image (it's actually too 1198 * contrasty.) Try the ALPHA_OPTIMIZED mode above - this will probably 1199 * substantially reduce the halos. Alternatively try: 1200 * 1201 * png_set_alpha_mode(pp, PNG_ALPHA_BROKEN, PNG_DEFAULT_sRGB); 1202 * This option will also reduce the halos, but there will be slight dark 1203 * halos round the opaque parts of the image where the background is light. 1204 * In the OPTIMIZED mode the halos will be light halos where the background 1205 * is dark. Take your pick - the halos are unavoidable unless you can get 1206 * your hardware/software fixed! (The OPTIMIZED approach is slightly 1207 * faster.) 1208 * 1209 * When the default gamma of PNG files doesn't match the output gamma. 1210 * If you have PNG files with no gamma information png_set_alpha_mode allows 1211 * you to provide a default gamma, but it also sets the output gamma to the 1212 * matching value. If you know your PNG files have a gamma that doesn't 1213 * match the output you can take advantage of the fact that 1214 * png_set_alpha_mode always sets the output gamma but only sets the PNG 1215 * default if it is not already set: 1216 * 1217 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB); 1218 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC); 1219 * The first call sets both the default and the output gamma values, the 1220 * second call overrides the output gamma without changing the default. This 1221 * is easier than achieving the same effect with png_set_gamma. You must use 1222 * PNG_ALPHA_PNG for the first call - internal checking in png_set_alpha will 1223 * fire if more than one call to png_set_alpha_mode and png_set_background is 1224 * made in the same read operation, however multiple calls with PNG_ALPHA_PNG 1225 * are ignored. 1226 */ 1227 1228 #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED 1229 PNG_EXPORT(36, void, png_set_strip_alpha, (png_structrp png_ptr)); 1230 #endif 1231 1232 #if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \ 1233 defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED) 1234 PNG_EXPORT(37, void, png_set_swap_alpha, (png_structrp png_ptr)); 1235 #endif 1236 1237 #if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \ 1238 defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED) 1239 PNG_EXPORT(38, void, png_set_invert_alpha, (png_structrp png_ptr)); 1240 #endif 1241 1242 #if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED) 1243 /* Add a filler byte to 8-bit or 16-bit Gray or 24-bit or 48-bit RGB images. */ 1244 PNG_EXPORT(39, void, png_set_filler, (png_structrp png_ptr, png_uint_32 filler, 1245 int flags)); 1246 /* The values of the PNG_FILLER_ defines should NOT be changed */ 1247 # define PNG_FILLER_BEFORE 0 1248 # define PNG_FILLER_AFTER 1 1249 /* Add an alpha byte to 8-bit or 16-bit Gray or 24-bit or 48-bit RGB images. */ 1250 PNG_EXPORT(40, void, png_set_add_alpha, (png_structrp png_ptr, 1251 png_uint_32 filler, int flags)); 1252 #endif /* READ_FILLER || WRITE_FILLER */ 1253 1254 #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED) 1255 /* Swap bytes in 16-bit depth files. */ 1256 PNG_EXPORT(41, void, png_set_swap, (png_structrp png_ptr)); 1257 #endif 1258 1259 #if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED) 1260 /* Use 1 byte per pixel in 1, 2, or 4-bit depth files. */ 1261 PNG_EXPORT(42, void, png_set_packing, (png_structrp png_ptr)); 1262 #endif 1263 1264 #if defined(PNG_READ_PACKSWAP_SUPPORTED) || \ 1265 defined(PNG_WRITE_PACKSWAP_SUPPORTED) 1266 /* Swap packing order of pixels in bytes. */ 1267 PNG_EXPORT(43, void, png_set_packswap, (png_structrp png_ptr)); 1268 #endif 1269 1270 #if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED) 1271 /* Converts files to legal bit depths. */ 1272 PNG_EXPORT(44, void, png_set_shift, (png_structrp png_ptr, png_const_color_8p 1273 true_bits)); 1274 #endif 1275 1276 #if defined(PNG_READ_INTERLACING_SUPPORTED) || \ 1277 defined(PNG_WRITE_INTERLACING_SUPPORTED) 1278 /* Have the code handle the interlacing. Returns the number of passes. 1279 * MUST be called before png_read_update_info or png_start_read_image, 1280 * otherwise it will not have the desired effect. Note that it is still 1281 * necessary to call png_read_row or png_read_rows png_get_image_height 1282 * times for each pass. 1283 */ 1284 PNG_EXPORT(45, int, png_set_interlace_handling, (png_structrp png_ptr)); 1285 #endif 1286 1287 #if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED) 1288 /* Invert monochrome files */ 1289 PNG_EXPORT(46, void, png_set_invert_mono, (png_structrp png_ptr)); 1290 #endif 1291 1292 #ifdef PNG_READ_BACKGROUND_SUPPORTED 1293 /* Handle alpha and tRNS by replacing with a background color. Prior to 1294 * libpng-1.5.4 this API must not be called before the PNG file header has been 1295 * read. Doing so will result in unexpected behavior and possible warnings or 1296 * errors if the PNG file contains a bKGD chunk. 1297 */ 1298 PNG_FP_EXPORT(47, void, png_set_background, (png_structrp png_ptr, 1299 png_const_color_16p background_color, int background_gamma_code, 1300 int need_expand, double background_gamma)) 1301 PNG_FIXED_EXPORT(215, void, png_set_background_fixed, (png_structrp png_ptr, 1302 png_const_color_16p background_color, int background_gamma_code, 1303 int need_expand, png_fixed_point background_gamma)) 1304 #endif 1305 #ifdef PNG_READ_BACKGROUND_SUPPORTED 1306 # define PNG_BACKGROUND_GAMMA_UNKNOWN 0 1307 # define PNG_BACKGROUND_GAMMA_SCREEN 1 1308 # define PNG_BACKGROUND_GAMMA_FILE 2 1309 # define PNG_BACKGROUND_GAMMA_UNIQUE 3 1310 #endif 1311 1312 #ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED 1313 /* Scale a 16-bit depth file down to 8-bit, accurately. */ 1314 PNG_EXPORT(229, void, png_set_scale_16, (png_structrp png_ptr)); 1315 #endif 1316 1317 #ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED 1318 #define PNG_READ_16_TO_8_SUPPORTED /* Name prior to 1.5.4 */ 1319 /* Strip the second byte of information from a 16-bit depth file. */ 1320 PNG_EXPORT(48, void, png_set_strip_16, (png_structrp png_ptr)); 1321 #endif 1322 1323 #ifdef PNG_READ_QUANTIZE_SUPPORTED 1324 /* Turn on quantizing, and reduce the palette to the number of colors 1325 * available. 1326 */ 1327 PNG_EXPORT(49, void, png_set_quantize, (png_structrp png_ptr, 1328 png_colorp palette, int num_palette, int maximum_colors, 1329 png_const_uint_16p histogram, int full_quantize)); 1330 #endif 1331 1332 #ifdef PNG_READ_GAMMA_SUPPORTED 1333 /* The threshold on gamma processing is configurable but hard-wired into the 1334 * library. The following is the floating point variant. 1335 */ 1336 #define PNG_GAMMA_THRESHOLD (PNG_GAMMA_THRESHOLD_FIXED*.00001) 1337 1338 /* Handle gamma correction. Screen_gamma=(display_exponent). 1339 * NOTE: this API simply sets the screen and file gamma values. It will 1340 * therefore override the value for gamma in a PNG file if it is called after 1341 * the file header has been read - use with care - call before reading the PNG 1342 * file for best results! 1343 * 1344 * These routines accept the same gamma values as png_set_alpha_mode (described 1345 * above). The PNG_GAMMA_ defines and PNG_DEFAULT_sRGB can be passed to either 1346 * API (floating point or fixed.) Notice, however, that the 'file_gamma' value 1347 * is the inverse of a 'screen gamma' value. 1348 */ 1349 PNG_FP_EXPORT(50, void, png_set_gamma, (png_structrp png_ptr, 1350 double screen_gamma, double override_file_gamma)) 1351 PNG_FIXED_EXPORT(208, void, png_set_gamma_fixed, (png_structrp png_ptr, 1352 png_fixed_point screen_gamma, png_fixed_point override_file_gamma)) 1353 #endif 1354 1355 #ifdef PNG_WRITE_FLUSH_SUPPORTED 1356 /* Set how many lines between output flushes - 0 for no flushing */ 1357 PNG_EXPORT(51, void, png_set_flush, (png_structrp png_ptr, int nrows)); 1358 /* Flush the current PNG output buffer */ 1359 PNG_EXPORT(52, void, png_write_flush, (png_structrp png_ptr)); 1360 #endif 1361 1362 /* Optional update palette with requested transformations */ 1363 PNG_EXPORT(53, void, png_start_read_image, (png_structrp png_ptr)); 1364 1365 /* Optional call to update the users info structure */ 1366 PNG_EXPORT(54, void, png_read_update_info, (png_structrp png_ptr, 1367 png_inforp info_ptr)); 1368 1369 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED 1370 /* Read one or more rows of image data. */ 1371 PNG_EXPORT(55, void, png_read_rows, (png_structrp png_ptr, png_bytepp row, 1372 png_bytepp display_row, png_uint_32 num_rows)); 1373 #endif 1374 1375 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED 1376 /* Read a row of data. */ 1377 PNG_EXPORT(56, void, png_read_row, (png_structrp png_ptr, png_bytep row, 1378 png_bytep display_row)); 1379 #endif 1380 1381 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED 1382 /* Read the whole image into memory at once. */ 1383 PNG_EXPORT(57, void, png_read_image, (png_structrp png_ptr, png_bytepp image)); 1384 #endif 1385 1386 /* Write a row of image data */ 1387 PNG_EXPORT(58, void, png_write_row, (png_structrp png_ptr, 1388 png_const_bytep row)); 1389 1390 /* Write a few rows of image data: (*row) is not written; however, the type 1391 * is declared as writeable to maintain compatibility with previous versions 1392 * of libpng and to allow the 'display_row' array from read_rows to be passed 1393 * unchanged to write_rows. 1394 */ 1395 PNG_EXPORT(59, void, png_write_rows, (png_structrp png_ptr, png_bytepp row, 1396 png_uint_32 num_rows)); 1397 1398 /* Write the image data */ 1399 PNG_EXPORT(60, void, png_write_image, (png_structrp png_ptr, png_bytepp image)); 1400 1401 /* Write the end of the PNG file. */ 1402 PNG_EXPORT(61, void, png_write_end, (png_structrp png_ptr, 1403 png_inforp info_ptr)); 1404 1405 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED 1406 /* Read the end of the PNG file. */ 1407 PNG_EXPORT(62, void, png_read_end, (png_structrp png_ptr, png_inforp info_ptr)); 1408 #endif 1409 1410 /* Free any memory associated with the png_info_struct */ 1411 PNG_EXPORT(63, void, png_destroy_info_struct, (png_const_structrp png_ptr, 1412 png_infopp info_ptr_ptr)); 1413 1414 /* Free any memory associated with the png_struct and the png_info_structs */ 1415 PNG_EXPORT(64, void, png_destroy_read_struct, (png_structpp png_ptr_ptr, 1416 png_infopp info_ptr_ptr, png_infopp end_info_ptr_ptr)); 1417 1418 /* Free any memory associated with the png_struct and the png_info_structs */ 1419 PNG_EXPORT(65, void, png_destroy_write_struct, (png_structpp png_ptr_ptr, 1420 png_infopp info_ptr_ptr)); 1421 1422 /* Set the libpng method of handling chunk CRC errors */ 1423 PNG_EXPORT(66, void, png_set_crc_action, (png_structrp png_ptr, int crit_action, 1424 int ancil_action)); 1425 1426 /* Values for png_set_crc_action() say how to handle CRC errors in 1427 * ancillary and critical chunks, and whether to use the data contained 1428 * therein. Note that it is impossible to "discard" data in a critical 1429 * chunk. For versions prior to 0.90, the action was always error/quit, 1430 * whereas in version 0.90 and later, the action for CRC errors in ancillary 1431 * chunks is warn/discard. These values should NOT be changed. 1432 * 1433 * value action:critical action:ancillary 1434 */ 1435 #define PNG_CRC_DEFAULT 0 /* error/quit warn/discard data */ 1436 #define PNG_CRC_ERROR_QUIT 1 /* error/quit error/quit */ 1437 #define PNG_CRC_WARN_DISCARD 2 /* (INVALID) warn/discard data */ 1438 #define PNG_CRC_WARN_USE 3 /* warn/use data warn/use data */ 1439 #define PNG_CRC_QUIET_USE 4 /* quiet/use data quiet/use data */ 1440 #define PNG_CRC_NO_CHANGE 5 /* use current value use current value */ 1441 1442 #ifdef PNG_WRITE_SUPPORTED 1443 /* These functions give the user control over the scan-line filtering in 1444 * libpng and the compression methods used by zlib. These functions are 1445 * mainly useful for testing, as the defaults should work with most users. 1446 * Those users who are tight on memory or want faster performance at the 1447 * expense of compression can modify them. See the compression library 1448 * header file (zlib.h) for an explanation of the compression functions. 1449 */ 1450 1451 /* Set the filtering method(s) used by libpng. Currently, the only valid 1452 * value for "method" is 0. 1453 */ 1454 PNG_EXPORT(67, void, png_set_filter, (png_structrp png_ptr, int method, 1455 int filters)); 1456 #endif /* WRITE */ 1457 1458 /* Flags for png_set_filter() to say which filters to use. The flags 1459 * are chosen so that they don't conflict with real filter types 1460 * below, in case they are supplied instead of the #defined constants. 1461 * These values should NOT be changed. 1462 */ 1463 #define PNG_NO_FILTERS 0x00 1464 #define PNG_FILTER_NONE 0x08 1465 #define PNG_FILTER_SUB 0x10 1466 #define PNG_FILTER_UP 0x20 1467 #define PNG_FILTER_AVG 0x40 1468 #define PNG_FILTER_PAETH 0x80 1469 #define PNG_FAST_FILTERS (PNG_FILTER_NONE | PNG_FILTER_SUB | PNG_FILTER_UP) 1470 #define PNG_ALL_FILTERS (PNG_FAST_FILTERS | PNG_FILTER_AVG | PNG_FILTER_PAETH) 1471 1472 /* Filter values (not flags) - used in pngwrite.c, pngwutil.c for now. 1473 * These defines should NOT be changed. 1474 */ 1475 #define PNG_FILTER_VALUE_NONE 0 1476 #define PNG_FILTER_VALUE_SUB 1 1477 #define PNG_FILTER_VALUE_UP 2 1478 #define PNG_FILTER_VALUE_AVG 3 1479 #define PNG_FILTER_VALUE_PAETH 4 1480 #define PNG_FILTER_VALUE_LAST 5 1481 1482 #ifdef PNG_WRITE_SUPPORTED 1483 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* DEPRECATED */ 1484 PNG_FP_EXPORT(68, void, png_set_filter_heuristics, (png_structrp png_ptr, 1485 int heuristic_method, int num_weights, png_const_doublep filter_weights, 1486 png_const_doublep filter_costs)) 1487 PNG_FIXED_EXPORT(209, void, png_set_filter_heuristics_fixed, 1488 (png_structrp png_ptr, int heuristic_method, int num_weights, 1489 png_const_fixed_point_p filter_weights, 1490 png_const_fixed_point_p filter_costs)) 1491 #endif /* WRITE_WEIGHTED_FILTER */ 1492 1493 /* The following are no longer used and will be removed from libpng-1.7: */ 1494 #define PNG_FILTER_HEURISTIC_DEFAULT 0 /* Currently "UNWEIGHTED" */ 1495 #define PNG_FILTER_HEURISTIC_UNWEIGHTED 1 /* Used by libpng < 0.95 */ 1496 #define PNG_FILTER_HEURISTIC_WEIGHTED 2 /* Experimental feature */ 1497 #define PNG_FILTER_HEURISTIC_LAST 3 /* Not a valid value */ 1498 1499 /* Set the library compression level. Currently, valid values range from 1500 * 0 - 9, corresponding directly to the zlib compression levels 0 - 9 1501 * (0 - no compression, 9 - "maximal" compression). Note that tests have 1502 * shown that zlib compression levels 3-6 usually perform as well as level 9 1503 * for PNG images, and do considerably fewer calculations. In the future, 1504 * these values may not correspond directly to the zlib compression levels. 1505 */ 1506 #ifdef PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED 1507 PNG_EXPORT(69, void, png_set_compression_level, (png_structrp png_ptr, 1508 int level)); 1509 1510 PNG_EXPORT(70, void, png_set_compression_mem_level, (png_structrp png_ptr, 1511 int mem_level)); 1512 1513 PNG_EXPORT(71, void, png_set_compression_strategy, (png_structrp png_ptr, 1514 int strategy)); 1515 1516 /* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a 1517 * smaller value of window_bits if it can do so safely. 1518 */ 1519 PNG_EXPORT(72, void, png_set_compression_window_bits, (png_structrp png_ptr, 1520 int window_bits)); 1521 1522 PNG_EXPORT(73, void, png_set_compression_method, (png_structrp png_ptr, 1523 int method)); 1524 #endif /* WRITE_CUSTOMIZE_COMPRESSION */ 1525 1526 #ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED 1527 /* Also set zlib parameters for compressing non-IDAT chunks */ 1528 PNG_EXPORT(222, void, png_set_text_compression_level, (png_structrp png_ptr, 1529 int level)); 1530 1531 PNG_EXPORT(223, void, png_set_text_compression_mem_level, (png_structrp png_ptr, 1532 int mem_level)); 1533 1534 PNG_EXPORT(224, void, png_set_text_compression_strategy, (png_structrp png_ptr, 1535 int strategy)); 1536 1537 /* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a 1538 * smaller value of window_bits if it can do so safely. 1539 */ 1540 PNG_EXPORT(225, void, png_set_text_compression_window_bits, 1541 (png_structrp png_ptr, int window_bits)); 1542 1543 PNG_EXPORT(226, void, png_set_text_compression_method, (png_structrp png_ptr, 1544 int method)); 1545 #endif /* WRITE_CUSTOMIZE_ZTXT_COMPRESSION */ 1546 #endif /* WRITE */ 1547 1548 /* These next functions are called for input/output, memory, and error 1549 * handling. They are in the file pngrio.c, pngwio.c, and pngerror.c, 1550 * and call standard C I/O routines such as fread(), fwrite(), and 1551 * fprintf(). These functions can be made to use other I/O routines 1552 * at run time for those applications that need to handle I/O in a 1553 * different manner by calling png_set_???_fn(). See libpng-manual.txt for 1554 * more information. 1555 */ 1556 1557 #ifdef PNG_STDIO_SUPPORTED 1558 /* Initialize the input/output for the PNG file to the default functions. */ 1559 PNG_EXPORT(74, void, png_init_io, (png_structrp png_ptr, png_FILE_p fp)); 1560 #endif 1561 1562 /* Replace the (error and abort), and warning functions with user 1563 * supplied functions. If no messages are to be printed you must still 1564 * write and use replacement functions. The replacement error_fn should 1565 * still do a longjmp to the last setjmp location if you are using this 1566 * method of error handling. If error_fn or warning_fn is NULL, the 1567 * default function will be used. 1568 */ 1569 1570 PNG_EXPORT(75, void, png_set_error_fn, (png_structrp png_ptr, 1571 png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warning_fn)); 1572 1573 /* Return the user pointer associated with the error functions */ 1574 PNG_EXPORT(76, png_voidp, png_get_error_ptr, (png_const_structrp png_ptr)); 1575 1576 /* Replace the default data output functions with a user supplied one(s). 1577 * If buffered output is not used, then output_flush_fn can be set to NULL. 1578 * If PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile time 1579 * output_flush_fn will be ignored (and thus can be NULL). 1580 * It is probably a mistake to use NULL for output_flush_fn if 1581 * write_data_fn is not also NULL unless you have built libpng with 1582 * PNG_WRITE_FLUSH_SUPPORTED undefined, because in this case libpng's 1583 * default flush function, which uses the standard *FILE structure, will 1584 * be used. 1585 */ 1586 PNG_EXPORT(77, void, png_set_write_fn, (png_structrp png_ptr, png_voidp io_ptr, 1587 png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn)); 1588 1589 /* Replace the default data input function with a user supplied one. */ 1590 PNG_EXPORT(78, void, png_set_read_fn, (png_structrp png_ptr, png_voidp io_ptr, 1591 png_rw_ptr read_data_fn)); 1592 1593 /* Return the user pointer associated with the I/O functions */ 1594 PNG_EXPORT(79, png_voidp, png_get_io_ptr, (png_const_structrp png_ptr)); 1595 1596 PNG_EXPORT(80, void, png_set_read_status_fn, (png_structrp png_ptr, 1597 png_read_status_ptr read_row_fn)); 1598 1599 PNG_EXPORT(81, void, png_set_write_status_fn, (png_structrp png_ptr, 1600 png_write_status_ptr write_row_fn)); 1601 1602 #ifdef PNG_USER_MEM_SUPPORTED 1603 /* Replace the default memory allocation functions with user supplied one(s). */ 1604 PNG_EXPORT(82, void, png_set_mem_fn, (png_structrp png_ptr, png_voidp mem_ptr, 1605 png_malloc_ptr malloc_fn, png_free_ptr free_fn)); 1606 /* Return the user pointer associated with the memory functions */ 1607 PNG_EXPORT(83, png_voidp, png_get_mem_ptr, (png_const_structrp png_ptr)); 1608 #endif 1609 1610 #ifdef PNG_READ_USER_TRANSFORM_SUPPORTED 1611 PNG_EXPORT(84, void, png_set_read_user_transform_fn, (png_structrp png_ptr, 1612 png_user_transform_ptr read_user_transform_fn)); 1613 #endif 1614 1615 #ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED 1616 PNG_EXPORT(85, void, png_set_write_user_transform_fn, (png_structrp png_ptr, 1617 png_user_transform_ptr write_user_transform_fn)); 1618 #endif 1619 1620 #ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED 1621 PNG_EXPORT(86, void, png_set_user_transform_info, (png_structrp png_ptr, 1622 png_voidp user_transform_ptr, int user_transform_depth, 1623 int user_transform_channels)); 1624 /* Return the user pointer associated with the user transform functions */ 1625 PNG_EXPORT(87, png_voidp, png_get_user_transform_ptr, 1626 (png_const_structrp png_ptr)); 1627 #endif 1628 1629 #ifdef PNG_USER_TRANSFORM_INFO_SUPPORTED 1630 /* Return information about the row currently being processed. Note that these 1631 * APIs do not fail but will return unexpected results if called outside a user 1632 * transform callback. Also note that when transforming an interlaced image the 1633 * row number is the row number within the sub-image of the interlace pass, so 1634 * the value will increase to the height of the sub-image (not the full image) 1635 * then reset to 0 for the next pass. 1636 * 1637 * Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to 1638 * find the output pixel (x,y) given an interlaced sub-image pixel 1639 * (row,col,pass). (See below for these macros.) 1640 */ 1641 PNG_EXPORT(217, png_uint_32, png_get_current_row_number, (png_const_structrp)); 1642 PNG_EXPORT(218, png_byte, png_get_current_pass_number, (png_const_structrp)); 1643 #endif 1644 1645 #ifdef PNG_READ_USER_CHUNKS_SUPPORTED 1646 /* This callback is called only for *unknown* chunks. If 1647 * PNG_HANDLE_AS_UNKNOWN_SUPPORTED is set then it is possible to set known 1648 * chunks to be treated as unknown, however in this case the callback must do 1649 * any processing required by the chunk (e.g. by calling the appropriate 1650 * png_set_ APIs.) 1651 * 1652 * There is no write support - on write, by default, all the chunks in the 1653 * 'unknown' list are written in the specified position. 1654 * 1655 * The integer return from the callback function is interpreted thus: 1656 * 1657 * negative: An error occurred; png_chunk_error will be called. 1658 * zero: The chunk was not handled, the chunk will be saved. A critical 1659 * chunk will cause an error at this point unless it is to be saved. 1660 * positive: The chunk was handled, libpng will ignore/discard it. 1661 * 1662 * See "INTERACTION WITH USER CHUNK CALLBACKS" below for important notes about 1663 * how this behavior will change in libpng 1.7 1664 */ 1665 PNG_EXPORT(88, void, png_set_read_user_chunk_fn, (png_structrp png_ptr, 1666 png_voidp user_chunk_ptr, png_user_chunk_ptr read_user_chunk_fn)); 1667 #endif 1668 1669 #ifdef PNG_USER_CHUNKS_SUPPORTED 1670 PNG_EXPORT(89, png_voidp, png_get_user_chunk_ptr, (png_const_structrp png_ptr)); 1671 #endif 1672 1673 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED 1674 /* Sets the function callbacks for the push reader, and a pointer to a 1675 * user-defined structure available to the callback functions. 1676 */ 1677 PNG_EXPORT(90, void, png_set_progressive_read_fn, (png_structrp png_ptr, 1678 png_voidp progressive_ptr, png_progressive_info_ptr info_fn, 1679 png_progressive_row_ptr row_fn, png_progressive_end_ptr end_fn)); 1680 1681 /* Returns the user pointer associated with the push read functions */ 1682 PNG_EXPORT(91, png_voidp, png_get_progressive_ptr, 1683 (png_const_structrp png_ptr)); 1684 1685 /* Function to be called when data becomes available */ 1686 PNG_EXPORT(92, void, png_process_data, (png_structrp png_ptr, 1687 png_inforp info_ptr, png_bytep buffer, size_t buffer_size)); 1688 1689 /* A function which may be called *only* within png_process_data to stop the 1690 * processing of any more data. The function returns the number of bytes 1691 * remaining, excluding any that libpng has cached internally. A subsequent 1692 * call to png_process_data must supply these bytes again. If the argument 1693 * 'save' is set to true the routine will first save all the pending data and 1694 * will always return 0. 1695 */ 1696 PNG_EXPORT(219, size_t, png_process_data_pause, (png_structrp, int save)); 1697 1698 /* A function which may be called *only* outside (after) a call to 1699 * png_process_data. It returns the number of bytes of data to skip in the 1700 * input. Normally it will return 0, but if it returns a non-zero value the 1701 * application must skip than number of bytes of input data and pass the 1702 * following data to the next call to png_process_data. 1703 */ 1704 PNG_EXPORT(220, png_uint_32, png_process_data_skip, (png_structrp)); 1705 1706 /* Function that combines rows. 'new_row' is a flag that should come from 1707 * the callback and be non-NULL if anything needs to be done; the library 1708 * stores its own version of the new data internally and ignores the passed 1709 * in value. 1710 */ 1711 PNG_EXPORT(93, void, png_progressive_combine_row, (png_const_structrp png_ptr, 1712 png_bytep old_row, png_const_bytep new_row)); 1713 #endif /* PROGRESSIVE_READ */ 1714 1715 PNG_EXPORTA(94, png_voidp, png_malloc, (png_const_structrp png_ptr, 1716 png_alloc_size_t size), PNG_ALLOCATED); 1717 /* Added at libpng version 1.4.0 */ 1718 PNG_EXPORTA(95, png_voidp, png_calloc, (png_const_structrp png_ptr, 1719 png_alloc_size_t size), PNG_ALLOCATED); 1720 1721 /* Added at libpng version 1.2.4 */ 1722 PNG_EXPORTA(96, png_voidp, png_malloc_warn, (png_const_structrp png_ptr, 1723 png_alloc_size_t size), PNG_ALLOCATED); 1724 1725 /* Frees a pointer allocated by png_malloc() */ 1726 PNG_EXPORT(97, void, png_free, (png_const_structrp png_ptr, png_voidp ptr)); 1727 1728 /* Free data that was allocated internally */ 1729 PNG_EXPORT(98, void, png_free_data, (png_const_structrp png_ptr, 1730 png_inforp info_ptr, png_uint_32 free_me, int num)); 1731 1732 /* Reassign the responsibility for freeing existing data, whether allocated 1733 * by libpng or by the application; this works on the png_info structure passed 1734 * in, without changing the state for other png_info structures. 1735 */ 1736 PNG_EXPORT(99, void, png_data_freer, (png_const_structrp png_ptr, 1737 png_inforp info_ptr, int freer, png_uint_32 mask)); 1738 1739 /* Assignments for png_data_freer */ 1740 #define PNG_DESTROY_WILL_FREE_DATA 1 1741 #define PNG_SET_WILL_FREE_DATA 1 1742 #define PNG_USER_WILL_FREE_DATA 2 1743 /* Flags for png_ptr->free_me and info_ptr->free_me */ 1744 #define PNG_FREE_HIST 0x0008U 1745 #define PNG_FREE_ICCP 0x0010U 1746 #define PNG_FREE_SPLT 0x0020U 1747 #define PNG_FREE_ROWS 0x0040U 1748 #define PNG_FREE_PCAL 0x0080U 1749 #define PNG_FREE_SCAL 0x0100U 1750 #ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED 1751 # define PNG_FREE_UNKN 0x0200U 1752 #endif 1753 /* PNG_FREE_LIST 0x0400U removed in 1.6.0 because it is ignored */ 1754 #define PNG_FREE_PLTE 0x1000U 1755 #define PNG_FREE_TRNS 0x2000U 1756 #define PNG_FREE_TEXT 0x4000U 1757 #define PNG_FREE_EXIF 0x8000U /* Added at libpng-1.6.31 */ 1758 #define PNG_FREE_ALL 0xffffU 1759 #define PNG_FREE_MUL 0x4220U /* PNG_FREE_SPLT|PNG_FREE_TEXT|PNG_FREE_UNKN */ 1760 1761 #ifdef PNG_USER_MEM_SUPPORTED 1762 PNG_EXPORTA(100, png_voidp, png_malloc_default, (png_const_structrp png_ptr, 1763 png_alloc_size_t size), PNG_ALLOCATED PNG_DEPRECATED); 1764 PNG_EXPORTA(101, void, png_free_default, (png_const_structrp png_ptr, 1765 png_voidp ptr), PNG_DEPRECATED); 1766 #endif 1767 1768 #ifdef PNG_ERROR_TEXT_SUPPORTED 1769 /* Fatal error in PNG image of libpng - can't continue */ 1770 PNG_EXPORTA(102, void, png_error, (png_const_structrp png_ptr, 1771 png_const_charp error_message), PNG_NORETURN); 1772 1773 /* The same, but the chunk name is prepended to the error string. */ 1774 PNG_EXPORTA(103, void, png_chunk_error, (png_const_structrp png_ptr, 1775 png_const_charp error_message), PNG_NORETURN); 1776 1777 #else 1778 /* Fatal error in PNG image of libpng - can't continue */ 1779 PNG_EXPORTA(104, void, png_err, (png_const_structrp png_ptr), PNG_NORETURN); 1780 # define png_error(s1,s2) png_err(s1) 1781 # define png_chunk_error(s1,s2) png_err(s1) 1782 #endif 1783 1784 #ifdef PNG_WARNINGS_SUPPORTED 1785 /* Non-fatal error in libpng. Can continue, but may have a problem. */ 1786 PNG_EXPORT(105, void, png_warning, (png_const_structrp png_ptr, 1787 png_const_charp warning_message)); 1788 1789 /* Non-fatal error in libpng, chunk name is prepended to message. */ 1790 PNG_EXPORT(106, void, png_chunk_warning, (png_const_structrp png_ptr, 1791 png_const_charp warning_message)); 1792 #else 1793 # define png_warning(s1,s2) ((void)(s1)) 1794 # define png_chunk_warning(s1,s2) ((void)(s1)) 1795 #endif 1796 1797 #ifdef PNG_BENIGN_ERRORS_SUPPORTED 1798 /* Benign error in libpng. Can continue, but may have a problem. 1799 * User can choose whether to handle as a fatal error or as a warning. */ 1800 PNG_EXPORT(107, void, png_benign_error, (png_const_structrp png_ptr, 1801 png_const_charp warning_message)); 1802 1803 #ifdef PNG_READ_SUPPORTED 1804 /* Same, chunk name is prepended to message (only during read) */ 1805 PNG_EXPORT(108, void, png_chunk_benign_error, (png_const_structrp png_ptr, 1806 png_const_charp warning_message)); 1807 #endif 1808 1809 PNG_EXPORT(109, void, png_set_benign_errors, 1810 (png_structrp png_ptr, int allowed)); 1811 #else 1812 # ifdef PNG_ALLOW_BENIGN_ERRORS 1813 # define png_benign_error png_warning 1814 # define png_chunk_benign_error png_chunk_warning 1815 # else 1816 # define png_benign_error png_error 1817 # define png_chunk_benign_error png_chunk_error 1818 # endif 1819 #endif 1820 1821 /* The png_set_<chunk> functions are for storing values in the png_info_struct. 1822 * Similarly, the png_get_<chunk> calls are used to read values from the 1823 * png_info_struct, either storing the parameters in the passed variables, or 1824 * setting pointers into the png_info_struct where the data is stored. The 1825 * png_get_<chunk> functions return a non-zero value if the data was available 1826 * in info_ptr, or return zero and do not change any of the parameters if the 1827 * data was not available. 1828 * 1829 * These functions should be used instead of directly accessing png_info 1830 * to avoid problems with future changes in the size and internal layout of 1831 * png_info_struct. 1832 */ 1833 /* Returns "flag" if chunk data is valid in info_ptr. */ 1834 PNG_EXPORT(110, png_uint_32, png_get_valid, (png_const_structrp png_ptr, 1835 png_const_inforp info_ptr, png_uint_32 flag)); 1836 1837 /* Returns number of bytes needed to hold a transformed row. */ 1838 PNG_EXPORT(111, size_t, png_get_rowbytes, (png_const_structrp png_ptr, 1839 png_const_inforp info_ptr)); 1840 1841 #ifdef PNG_INFO_IMAGE_SUPPORTED 1842 /* Returns row_pointers, which is an array of pointers to scanlines that was 1843 * returned from png_read_png(). 1844 */ 1845 PNG_EXPORT(112, png_bytepp, png_get_rows, (png_const_structrp png_ptr, 1846 png_const_inforp info_ptr)); 1847 1848 /* Set row_pointers, which is an array of pointers to scanlines for use 1849 * by png_write_png(). 1850 */ 1851 PNG_EXPORT(113, void, png_set_rows, (png_const_structrp png_ptr, 1852 png_inforp info_ptr, png_bytepp row_pointers)); 1853 #endif 1854 1855 /* Returns number of color channels in image. */ 1856 PNG_EXPORT(114, png_byte, png_get_channels, (png_const_structrp png_ptr, 1857 png_const_inforp info_ptr)); 1858 1859 #ifdef PNG_EASY_ACCESS_SUPPORTED 1860 /* Returns image width in pixels. */ 1861 PNG_EXPORT(115, png_uint_32, png_get_image_width, (png_const_structrp png_ptr, 1862 png_const_inforp info_ptr)); 1863 1864 /* Returns image height in pixels. */ 1865 PNG_EXPORT(116, png_uint_32, png_get_image_height, (png_const_structrp png_ptr, 1866 png_const_inforp info_ptr)); 1867 1868 /* Returns image bit_depth. */ 1869 PNG_EXPORT(117, png_byte, png_get_bit_depth, (png_const_structrp png_ptr, 1870 png_const_inforp info_ptr)); 1871 1872 /* Returns image color_type. */ 1873 PNG_EXPORT(118, png_byte, png_get_color_type, (png_const_structrp png_ptr, 1874 png_const_inforp info_ptr)); 1875 1876 /* Returns image filter_type. */ 1877 PNG_EXPORT(119, png_byte, png_get_filter_type, (png_const_structrp png_ptr, 1878 png_const_inforp info_ptr)); 1879 1880 /* Returns image interlace_type. */ 1881 PNG_EXPORT(120, png_byte, png_get_interlace_type, (png_const_structrp png_ptr, 1882 png_const_inforp info_ptr)); 1883 1884 /* Returns image compression_type. */ 1885 PNG_EXPORT(121, png_byte, png_get_compression_type, (png_const_structrp png_ptr, 1886 png_const_inforp info_ptr)); 1887 1888 /* Returns image resolution in pixels per meter, from pHYs chunk data. */ 1889 PNG_EXPORT(122, png_uint_32, png_get_pixels_per_meter, 1890 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 1891 PNG_EXPORT(123, png_uint_32, png_get_x_pixels_per_meter, 1892 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 1893 PNG_EXPORT(124, png_uint_32, png_get_y_pixels_per_meter, 1894 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 1895 1896 /* Returns pixel aspect ratio, computed from pHYs chunk data. */ 1897 PNG_FP_EXPORT(125, float, png_get_pixel_aspect_ratio, 1898 (png_const_structrp png_ptr, png_const_inforp info_ptr)) 1899 PNG_FIXED_EXPORT(210, png_fixed_point, png_get_pixel_aspect_ratio_fixed, 1900 (png_const_structrp png_ptr, png_const_inforp info_ptr)) 1901 1902 /* Returns image x, y offset in pixels or microns, from oFFs chunk data. */ 1903 PNG_EXPORT(126, png_int_32, png_get_x_offset_pixels, 1904 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 1905 PNG_EXPORT(127, png_int_32, png_get_y_offset_pixels, 1906 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 1907 PNG_EXPORT(128, png_int_32, png_get_x_offset_microns, 1908 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 1909 PNG_EXPORT(129, png_int_32, png_get_y_offset_microns, 1910 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 1911 1912 #endif /* EASY_ACCESS */ 1913 1914 #ifdef PNG_READ_SUPPORTED 1915 /* Returns pointer to signature string read from PNG header */ 1916 PNG_EXPORT(130, png_const_bytep, png_get_signature, (png_const_structrp png_ptr, 1917 png_const_inforp info_ptr)); 1918 #endif 1919 1920 #ifdef PNG_bKGD_SUPPORTED 1921 PNG_EXPORT(131, png_uint_32, png_get_bKGD, (png_const_structrp png_ptr, 1922 png_inforp info_ptr, png_color_16p *background)); 1923 #endif 1924 1925 #ifdef PNG_bKGD_SUPPORTED 1926 PNG_EXPORT(132, void, png_set_bKGD, (png_const_structrp png_ptr, 1927 png_inforp info_ptr, png_const_color_16p background)); 1928 #endif 1929 1930 #ifdef PNG_cHRM_SUPPORTED 1931 PNG_FP_EXPORT(133, png_uint_32, png_get_cHRM, (png_const_structrp png_ptr, 1932 png_const_inforp info_ptr, double *white_x, double *white_y, double *red_x, 1933 double *red_y, double *green_x, double *green_y, double *blue_x, 1934 double *blue_y)) 1935 PNG_FP_EXPORT(230, png_uint_32, png_get_cHRM_XYZ, (png_const_structrp png_ptr, 1936 png_const_inforp info_ptr, double *red_X, double *red_Y, double *red_Z, 1937 double *green_X, double *green_Y, double *green_Z, double *blue_X, 1938 double *blue_Y, double *blue_Z)) 1939 PNG_FIXED_EXPORT(134, png_uint_32, png_get_cHRM_fixed, 1940 (png_const_structrp png_ptr, png_const_inforp info_ptr, 1941 png_fixed_point *int_white_x, png_fixed_point *int_white_y, 1942 png_fixed_point *int_red_x, png_fixed_point *int_red_y, 1943 png_fixed_point *int_green_x, png_fixed_point *int_green_y, 1944 png_fixed_point *int_blue_x, png_fixed_point *int_blue_y)) 1945 PNG_FIXED_EXPORT(231, png_uint_32, png_get_cHRM_XYZ_fixed, 1946 (png_const_structrp png_ptr, png_const_inforp info_ptr, 1947 png_fixed_point *int_red_X, png_fixed_point *int_red_Y, 1948 png_fixed_point *int_red_Z, png_fixed_point *int_green_X, 1949 png_fixed_point *int_green_Y, png_fixed_point *int_green_Z, 1950 png_fixed_point *int_blue_X, png_fixed_point *int_blue_Y, 1951 png_fixed_point *int_blue_Z)) 1952 #endif 1953 1954 #ifdef PNG_cHRM_SUPPORTED 1955 PNG_FP_EXPORT(135, void, png_set_cHRM, (png_const_structrp png_ptr, 1956 png_inforp info_ptr, 1957 double white_x, double white_y, double red_x, double red_y, double green_x, 1958 double green_y, double blue_x, double blue_y)) 1959 PNG_FP_EXPORT(232, void, png_set_cHRM_XYZ, (png_const_structrp png_ptr, 1960 png_inforp info_ptr, double red_X, double red_Y, double red_Z, 1961 double green_X, double green_Y, double green_Z, double blue_X, 1962 double blue_Y, double blue_Z)) 1963 PNG_FIXED_EXPORT(136, void, png_set_cHRM_fixed, (png_const_structrp png_ptr, 1964 png_inforp info_ptr, png_fixed_point int_white_x, 1965 png_fixed_point int_white_y, png_fixed_point int_red_x, 1966 png_fixed_point int_red_y, png_fixed_point int_green_x, 1967 png_fixed_point int_green_y, png_fixed_point int_blue_x, 1968 png_fixed_point int_blue_y)) 1969 PNG_FIXED_EXPORT(233, void, png_set_cHRM_XYZ_fixed, (png_const_structrp png_ptr, 1970 png_inforp info_ptr, png_fixed_point int_red_X, png_fixed_point int_red_Y, 1971 png_fixed_point int_red_Z, png_fixed_point int_green_X, 1972 png_fixed_point int_green_Y, png_fixed_point int_green_Z, 1973 png_fixed_point int_blue_X, png_fixed_point int_blue_Y, 1974 png_fixed_point int_blue_Z)) 1975 #endif 1976 1977 #ifdef PNG_eXIf_SUPPORTED 1978 PNG_EXPORT(246, png_uint_32, png_get_eXIf, (png_const_structrp png_ptr, 1979 png_inforp info_ptr, png_bytep *exif)); 1980 PNG_EXPORT(247, void, png_set_eXIf, (png_const_structrp png_ptr, 1981 png_inforp info_ptr, png_bytep exif)); 1982 1983 PNG_EXPORT(248, png_uint_32, png_get_eXIf_1, (png_const_structrp png_ptr, 1984 png_const_inforp info_ptr, png_uint_32 *num_exif, png_bytep *exif)); 1985 PNG_EXPORT(249, void, png_set_eXIf_1, (png_const_structrp png_ptr, 1986 png_inforp info_ptr, png_uint_32 num_exif, png_bytep exif)); 1987 #endif 1988 1989 #ifdef PNG_gAMA_SUPPORTED 1990 PNG_FP_EXPORT(137, png_uint_32, png_get_gAMA, (png_const_structrp png_ptr, 1991 png_const_inforp info_ptr, double *file_gamma)) 1992 PNG_FIXED_EXPORT(138, png_uint_32, png_get_gAMA_fixed, 1993 (png_const_structrp png_ptr, png_const_inforp info_ptr, 1994 png_fixed_point *int_file_gamma)) 1995 #endif 1996 1997 #ifdef PNG_gAMA_SUPPORTED 1998 PNG_FP_EXPORT(139, void, png_set_gAMA, (png_const_structrp png_ptr, 1999 png_inforp info_ptr, double file_gamma)) 2000 PNG_FIXED_EXPORT(140, void, png_set_gAMA_fixed, (png_const_structrp png_ptr, 2001 png_inforp info_ptr, png_fixed_point int_file_gamma)) 2002 #endif 2003 2004 #ifdef PNG_hIST_SUPPORTED 2005 PNG_EXPORT(141, png_uint_32, png_get_hIST, (png_const_structrp png_ptr, 2006 png_inforp info_ptr, png_uint_16p *hist)); 2007 PNG_EXPORT(142, void, png_set_hIST, (png_const_structrp png_ptr, 2008 png_inforp info_ptr, png_const_uint_16p hist)); 2009 #endif 2010 2011 PNG_EXPORT(143, png_uint_32, png_get_IHDR, (png_const_structrp png_ptr, 2012 png_const_inforp info_ptr, png_uint_32 *width, png_uint_32 *height, 2013 int *bit_depth, int *color_type, int *interlace_method, 2014 int *compression_method, int *filter_method)); 2015 2016 PNG_EXPORT(144, void, png_set_IHDR, (png_const_structrp png_ptr, 2017 png_inforp info_ptr, png_uint_32 width, png_uint_32 height, int bit_depth, 2018 int color_type, int interlace_method, int compression_method, 2019 int filter_method)); 2020 2021 #ifdef PNG_oFFs_SUPPORTED 2022 PNG_EXPORT(145, png_uint_32, png_get_oFFs, (png_const_structrp png_ptr, 2023 png_const_inforp info_ptr, png_int_32 *offset_x, png_int_32 *offset_y, 2024 int *unit_type)); 2025 #endif 2026 2027 #ifdef PNG_oFFs_SUPPORTED 2028 PNG_EXPORT(146, void, png_set_oFFs, (png_const_structrp png_ptr, 2029 png_inforp info_ptr, png_int_32 offset_x, png_int_32 offset_y, 2030 int unit_type)); 2031 #endif 2032 2033 #ifdef PNG_pCAL_SUPPORTED 2034 PNG_EXPORT(147, png_uint_32, png_get_pCAL, (png_const_structrp png_ptr, 2035 png_inforp info_ptr, png_charp *purpose, png_int_32 *X0, 2036 png_int_32 *X1, int *type, int *nparams, png_charp *units, 2037 png_charpp *params)); 2038 #endif 2039 2040 #ifdef PNG_pCAL_SUPPORTED 2041 PNG_EXPORT(148, void, png_set_pCAL, (png_const_structrp png_ptr, 2042 png_inforp info_ptr, png_const_charp purpose, png_int_32 X0, png_int_32 X1, 2043 int type, int nparams, png_const_charp units, png_charpp params)); 2044 #endif 2045 2046 #ifdef PNG_pHYs_SUPPORTED 2047 PNG_EXPORT(149, png_uint_32, png_get_pHYs, (png_const_structrp png_ptr, 2048 png_const_inforp info_ptr, png_uint_32 *res_x, png_uint_32 *res_y, 2049 int *unit_type)); 2050 #endif 2051 2052 #ifdef PNG_pHYs_SUPPORTED 2053 PNG_EXPORT(150, void, png_set_pHYs, (png_const_structrp png_ptr, 2054 png_inforp info_ptr, png_uint_32 res_x, png_uint_32 res_y, int unit_type)); 2055 #endif 2056 2057 PNG_EXPORT(151, png_uint_32, png_get_PLTE, (png_const_structrp png_ptr, 2058 png_inforp info_ptr, png_colorp *palette, int *num_palette)); 2059 2060 PNG_EXPORT(152, void, png_set_PLTE, (png_structrp png_ptr, 2061 png_inforp info_ptr, png_const_colorp palette, int num_palette)); 2062 2063 #ifdef PNG_sBIT_SUPPORTED 2064 PNG_EXPORT(153, png_uint_32, png_get_sBIT, (png_const_structrp png_ptr, 2065 png_inforp info_ptr, png_color_8p *sig_bit)); 2066 #endif 2067 2068 #ifdef PNG_sBIT_SUPPORTED 2069 PNG_EXPORT(154, void, png_set_sBIT, (png_const_structrp png_ptr, 2070 png_inforp info_ptr, png_const_color_8p sig_bit)); 2071 #endif 2072 2073 #ifdef PNG_sRGB_SUPPORTED 2074 PNG_EXPORT(155, png_uint_32, png_get_sRGB, (png_const_structrp png_ptr, 2075 png_const_inforp info_ptr, int *file_srgb_intent)); 2076 #endif 2077 2078 #ifdef PNG_sRGB_SUPPORTED 2079 PNG_EXPORT(156, void, png_set_sRGB, (png_const_structrp png_ptr, 2080 png_inforp info_ptr, int srgb_intent)); 2081 PNG_EXPORT(157, void, png_set_sRGB_gAMA_and_cHRM, (png_const_structrp png_ptr, 2082 png_inforp info_ptr, int srgb_intent)); 2083 #endif 2084 2085 #ifdef PNG_iCCP_SUPPORTED 2086 PNG_EXPORT(158, png_uint_32, png_get_iCCP, (png_const_structrp png_ptr, 2087 png_inforp info_ptr, png_charpp name, int *compression_type, 2088 png_bytepp profile, png_uint_32 *proflen)); 2089 #endif 2090 2091 #ifdef PNG_iCCP_SUPPORTED 2092 PNG_EXPORT(159, void, png_set_iCCP, (png_const_structrp png_ptr, 2093 png_inforp info_ptr, png_const_charp name, int compression_type, 2094 png_const_bytep profile, png_uint_32 proflen)); 2095 #endif 2096 2097 #ifdef PNG_sPLT_SUPPORTED 2098 PNG_EXPORT(160, int, png_get_sPLT, (png_const_structrp png_ptr, 2099 png_inforp info_ptr, png_sPLT_tpp entries)); 2100 #endif 2101 2102 #ifdef PNG_sPLT_SUPPORTED 2103 PNG_EXPORT(161, void, png_set_sPLT, (png_const_structrp png_ptr, 2104 png_inforp info_ptr, png_const_sPLT_tp entries, int nentries)); 2105 #endif 2106 2107 #ifdef PNG_TEXT_SUPPORTED 2108 /* png_get_text also returns the number of text chunks in *num_text */ 2109 PNG_EXPORT(162, int, png_get_text, (png_const_structrp png_ptr, 2110 png_inforp info_ptr, png_textp *text_ptr, int *num_text)); 2111 #endif 2112 2113 /* Note while png_set_text() will accept a structure whose text, 2114 * language, and translated keywords are NULL pointers, the structure 2115 * returned by png_get_text will always contain regular 2116 * zero-terminated C strings. They might be empty strings but 2117 * they will never be NULL pointers. 2118 */ 2119 2120 #ifdef PNG_TEXT_SUPPORTED 2121 PNG_EXPORT(163, void, png_set_text, (png_const_structrp png_ptr, 2122 png_inforp info_ptr, png_const_textp text_ptr, int num_text)); 2123 #endif 2124 2125 #ifdef PNG_tIME_SUPPORTED 2126 PNG_EXPORT(164, png_uint_32, png_get_tIME, (png_const_structrp png_ptr, 2127 png_inforp info_ptr, png_timep *mod_time)); 2128 #endif 2129 2130 #ifdef PNG_tIME_SUPPORTED 2131 PNG_EXPORT(165, void, png_set_tIME, (png_const_structrp png_ptr, 2132 png_inforp info_ptr, png_const_timep mod_time)); 2133 #endif 2134 2135 #ifdef PNG_tRNS_SUPPORTED 2136 PNG_EXPORT(166, png_uint_32, png_get_tRNS, (png_const_structrp png_ptr, 2137 png_inforp info_ptr, png_bytep *trans_alpha, int *num_trans, 2138 png_color_16p *trans_color)); 2139 #endif 2140 2141 #ifdef PNG_tRNS_SUPPORTED 2142 PNG_EXPORT(167, void, png_set_tRNS, (png_structrp png_ptr, 2143 png_inforp info_ptr, png_const_bytep trans_alpha, int num_trans, 2144 png_const_color_16p trans_color)); 2145 #endif 2146 2147 #ifdef PNG_sCAL_SUPPORTED 2148 PNG_FP_EXPORT(168, png_uint_32, png_get_sCAL, (png_const_structrp png_ptr, 2149 png_const_inforp info_ptr, int *unit, double *width, double *height)) 2150 #if defined(PNG_FLOATING_ARITHMETIC_SUPPORTED) || \ 2151 defined(PNG_FLOATING_POINT_SUPPORTED) 2152 /* NOTE: this API is currently implemented using floating point arithmetic, 2153 * consequently it can only be used on systems with floating point support. 2154 * In any case the range of values supported by png_fixed_point is small and it 2155 * is highly recommended that png_get_sCAL_s be used instead. 2156 */ 2157 PNG_FIXED_EXPORT(214, png_uint_32, png_get_sCAL_fixed, 2158 (png_const_structrp png_ptr, png_const_inforp info_ptr, int *unit, 2159 png_fixed_point *width, png_fixed_point *height)) 2160 #endif 2161 PNG_EXPORT(169, png_uint_32, png_get_sCAL_s, 2162 (png_const_structrp png_ptr, png_const_inforp info_ptr, int *unit, 2163 png_charpp swidth, png_charpp sheight)); 2164 2165 PNG_FP_EXPORT(170, void, png_set_sCAL, (png_const_structrp png_ptr, 2166 png_inforp info_ptr, int unit, double width, double height)) 2167 PNG_FIXED_EXPORT(213, void, png_set_sCAL_fixed, (png_const_structrp png_ptr, 2168 png_inforp info_ptr, int unit, png_fixed_point width, 2169 png_fixed_point height)) 2170 PNG_EXPORT(171, void, png_set_sCAL_s, (png_const_structrp png_ptr, 2171 png_inforp info_ptr, int unit, 2172 png_const_charp swidth, png_const_charp sheight)); 2173 #endif /* sCAL */ 2174 2175 #ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED 2176 /* Provide the default handling for all unknown chunks or, optionally, for 2177 * specific unknown chunks. 2178 * 2179 * NOTE: prior to 1.6.0 the handling specified for particular chunks on read was 2180 * ignored and the default was used, the per-chunk setting only had an effect on 2181 * write. If you wish to have chunk-specific handling on read in code that must 2182 * work on earlier versions you must use a user chunk callback to specify the 2183 * desired handling (keep or discard.) 2184 * 2185 * The 'keep' parameter is a PNG_HANDLE_CHUNK_ value as listed below. The 2186 * parameter is interpreted as follows: 2187 * 2188 * READ: 2189 * PNG_HANDLE_CHUNK_AS_DEFAULT: 2190 * Known chunks: do normal libpng processing, do not keep the chunk (but 2191 * see the comments below about PNG_HANDLE_AS_UNKNOWN_SUPPORTED) 2192 * Unknown chunks: for a specific chunk use the global default, when used 2193 * as the default discard the chunk data. 2194 * PNG_HANDLE_CHUNK_NEVER: 2195 * Discard the chunk data. 2196 * PNG_HANDLE_CHUNK_IF_SAFE: 2197 * Keep the chunk data if the chunk is not critical else raise a chunk 2198 * error. 2199 * PNG_HANDLE_CHUNK_ALWAYS: 2200 * Keep the chunk data. 2201 * 2202 * If the chunk data is saved it can be retrieved using png_get_unknown_chunks, 2203 * below. Notice that specifying "AS_DEFAULT" as a global default is equivalent 2204 * to specifying "NEVER", however when "AS_DEFAULT" is used for specific chunks 2205 * it simply resets the behavior to the libpng default. 2206 * 2207 * INTERACTION WITH USER CHUNK CALLBACKS: 2208 * The per-chunk handling is always used when there is a png_user_chunk_ptr 2209 * callback and the callback returns 0; the chunk is then always stored *unless* 2210 * it is critical and the per-chunk setting is other than ALWAYS. Notice that 2211 * the global default is *not* used in this case. (In effect the per-chunk 2212 * value is incremented to at least IF_SAFE.) 2213 * 2214 * IMPORTANT NOTE: this behavior will change in libpng 1.7 - the global and 2215 * per-chunk defaults will be honored. If you want to preserve the current 2216 * behavior when your callback returns 0 you must set PNG_HANDLE_CHUNK_IF_SAFE 2217 * as the default - if you don't do this libpng 1.6 will issue a warning. 2218 * 2219 * If you want unhandled unknown chunks to be discarded in libpng 1.6 and 2220 * earlier simply return '1' (handled). 2221 * 2222 * PNG_HANDLE_AS_UNKNOWN_SUPPORTED: 2223 * If this is *not* set known chunks will always be handled by libpng and 2224 * will never be stored in the unknown chunk list. Known chunks listed to 2225 * png_set_keep_unknown_chunks will have no effect. If it is set then known 2226 * chunks listed with a keep other than AS_DEFAULT will *never* be processed 2227 * by libpng, in addition critical chunks must either be processed by the 2228 * callback or saved. 2229 * 2230 * The IHDR and IEND chunks must not be listed. Because this turns off the 2231 * default handling for chunks that would otherwise be recognized the 2232 * behavior of libpng transformations may well become incorrect! 2233 * 2234 * WRITE: 2235 * When writing chunks the options only apply to the chunks specified by 2236 * png_set_unknown_chunks (below), libpng will *always* write known chunks 2237 * required by png_set_ calls and will always write the core critical chunks 2238 * (as required for PLTE). 2239 * 2240 * Each chunk in the png_set_unknown_chunks list is looked up in the 2241 * png_set_keep_unknown_chunks list to find the keep setting, this is then 2242 * interpreted as follows: 2243 * 2244 * PNG_HANDLE_CHUNK_AS_DEFAULT: 2245 * Write safe-to-copy chunks and write other chunks if the global 2246 * default is set to _ALWAYS, otherwise don't write this chunk. 2247 * PNG_HANDLE_CHUNK_NEVER: 2248 * Do not write the chunk. 2249 * PNG_HANDLE_CHUNK_IF_SAFE: 2250 * Write the chunk if it is safe-to-copy, otherwise do not write it. 2251 * PNG_HANDLE_CHUNK_ALWAYS: 2252 * Write the chunk. 2253 * 2254 * Note that the default behavior is effectively the opposite of the read case - 2255 * in read unknown chunks are not stored by default, in write they are written 2256 * by default. Also the behavior of PNG_HANDLE_CHUNK_IF_SAFE is very different 2257 * - on write the safe-to-copy bit is checked, on read the critical bit is 2258 * checked and on read if the chunk is critical an error will be raised. 2259 * 2260 * num_chunks: 2261 * =========== 2262 * If num_chunks is positive, then the "keep" parameter specifies the manner 2263 * for handling only those chunks appearing in the chunk_list array, 2264 * otherwise the chunk list array is ignored. 2265 * 2266 * If num_chunks is 0 the "keep" parameter specifies the default behavior for 2267 * unknown chunks, as described above. 2268 * 2269 * If num_chunks is negative, then the "keep" parameter specifies the manner 2270 * for handling all unknown chunks plus all chunks recognized by libpng 2271 * except for the IHDR, PLTE, tRNS, IDAT, and IEND chunks (which continue to 2272 * be processed by libpng. 2273 */ 2274 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED 2275 PNG_EXPORT(172, void, png_set_keep_unknown_chunks, (png_structrp png_ptr, 2276 int keep, png_const_bytep chunk_list, int num_chunks)); 2277 #endif /* HANDLE_AS_UNKNOWN */ 2278 2279 /* The "keep" PNG_HANDLE_CHUNK_ parameter for the specified chunk is returned; 2280 * the result is therefore true (non-zero) if special handling is required, 2281 * false for the default handling. 2282 */ 2283 PNG_EXPORT(173, int, png_handle_as_unknown, (png_const_structrp png_ptr, 2284 png_const_bytep chunk_name)); 2285 #endif /* SET_UNKNOWN_CHUNKS */ 2286 2287 #ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED 2288 PNG_EXPORT(174, void, png_set_unknown_chunks, (png_const_structrp png_ptr, 2289 png_inforp info_ptr, png_const_unknown_chunkp unknowns, 2290 int num_unknowns)); 2291 /* NOTE: prior to 1.6.0 this routine set the 'location' field of the added 2292 * unknowns to the location currently stored in the png_struct. This is 2293 * invariably the wrong value on write. To fix this call the following API 2294 * for each chunk in the list with the correct location. If you know your 2295 * code won't be compiled on earlier versions you can rely on 2296 * png_set_unknown_chunks(write-ptr, png_get_unknown_chunks(read-ptr)) doing 2297 * the correct thing. 2298 */ 2299 2300 PNG_EXPORT(175, void, png_set_unknown_chunk_location, 2301 (png_const_structrp png_ptr, png_inforp info_ptr, int chunk, int location)); 2302 2303 PNG_EXPORT(176, int, png_get_unknown_chunks, (png_const_structrp png_ptr, 2304 png_inforp info_ptr, png_unknown_chunkpp entries)); 2305 #endif 2306 2307 /* Png_free_data() will turn off the "valid" flag for anything it frees. 2308 * If you need to turn it off for a chunk that your application has freed, 2309 * you can use png_set_invalid(png_ptr, info_ptr, PNG_INFO_CHNK); 2310 */ 2311 PNG_EXPORT(177, void, png_set_invalid, (png_const_structrp png_ptr, 2312 png_inforp info_ptr, int mask)); 2313 2314 #ifdef PNG_INFO_IMAGE_SUPPORTED 2315 /* The "params" pointer is currently not used and is for future expansion. */ 2316 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED 2317 PNG_EXPORT(178, void, png_read_png, (png_structrp png_ptr, png_inforp info_ptr, 2318 int transforms, png_voidp params)); 2319 #endif 2320 #ifdef PNG_WRITE_SUPPORTED 2321 PNG_EXPORT(179, void, png_write_png, (png_structrp png_ptr, png_inforp info_ptr, 2322 int transforms, png_voidp params)); 2323 #endif 2324 #endif 2325 2326 PNG_EXPORT(180, png_const_charp, png_get_copyright, 2327 (png_const_structrp png_ptr)); 2328 PNG_EXPORT(181, png_const_charp, png_get_header_ver, 2329 (png_const_structrp png_ptr)); 2330 PNG_EXPORT(182, png_const_charp, png_get_header_version, 2331 (png_const_structrp png_ptr)); 2332 PNG_EXPORT(183, png_const_charp, png_get_libpng_ver, 2333 (png_const_structrp png_ptr)); 2334 2335 #ifdef PNG_MNG_FEATURES_SUPPORTED 2336 PNG_EXPORT(184, png_uint_32, png_permit_mng_features, (png_structrp png_ptr, 2337 png_uint_32 mng_features_permitted)); 2338 #endif 2339 2340 /* For use in png_set_keep_unknown, added to version 1.2.6 */ 2341 #define PNG_HANDLE_CHUNK_AS_DEFAULT 0 2342 #define PNG_HANDLE_CHUNK_NEVER 1 2343 #define PNG_HANDLE_CHUNK_IF_SAFE 2 2344 #define PNG_HANDLE_CHUNK_ALWAYS 3 2345 #define PNG_HANDLE_CHUNK_LAST 4 2346 2347 /* Strip the prepended error numbers ("#nnn ") from error and warning 2348 * messages before passing them to the error or warning handler. 2349 */ 2350 #ifdef PNG_ERROR_NUMBERS_SUPPORTED 2351 PNG_EXPORT(185, void, png_set_strip_error_numbers, (png_structrp png_ptr, 2352 png_uint_32 strip_mode)); 2353 #endif 2354 2355 /* Added in libpng-1.2.6 */ 2356 #ifdef PNG_SET_USER_LIMITS_SUPPORTED 2357 PNG_EXPORT(186, void, png_set_user_limits, (png_structrp png_ptr, 2358 png_uint_32 user_width_max, png_uint_32 user_height_max)); 2359 PNG_EXPORT(187, png_uint_32, png_get_user_width_max, 2360 (png_const_structrp png_ptr)); 2361 PNG_EXPORT(188, png_uint_32, png_get_user_height_max, 2362 (png_const_structrp png_ptr)); 2363 /* Added in libpng-1.4.0 */ 2364 PNG_EXPORT(189, void, png_set_chunk_cache_max, (png_structrp png_ptr, 2365 png_uint_32 user_chunk_cache_max)); 2366 PNG_EXPORT(190, png_uint_32, png_get_chunk_cache_max, 2367 (png_const_structrp png_ptr)); 2368 /* Added in libpng-1.4.1 */ 2369 PNG_EXPORT(191, void, png_set_chunk_malloc_max, (png_structrp png_ptr, 2370 png_alloc_size_t user_chunk_cache_max)); 2371 PNG_EXPORT(192, png_alloc_size_t, png_get_chunk_malloc_max, 2372 (png_const_structrp png_ptr)); 2373 #endif 2374 2375 #if defined(PNG_INCH_CONVERSIONS_SUPPORTED) 2376 PNG_EXPORT(193, png_uint_32, png_get_pixels_per_inch, 2377 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 2378 2379 PNG_EXPORT(194, png_uint_32, png_get_x_pixels_per_inch, 2380 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 2381 2382 PNG_EXPORT(195, png_uint_32, png_get_y_pixels_per_inch, 2383 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 2384 2385 PNG_FP_EXPORT(196, float, png_get_x_offset_inches, 2386 (png_const_structrp png_ptr, png_const_inforp info_ptr)) 2387 #ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */ 2388 PNG_FIXED_EXPORT(211, png_fixed_point, png_get_x_offset_inches_fixed, 2389 (png_const_structrp png_ptr, png_const_inforp info_ptr)) 2390 #endif 2391 2392 PNG_FP_EXPORT(197, float, png_get_y_offset_inches, (png_const_structrp png_ptr, 2393 png_const_inforp info_ptr)) 2394 #ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */ 2395 PNG_FIXED_EXPORT(212, png_fixed_point, png_get_y_offset_inches_fixed, 2396 (png_const_structrp png_ptr, png_const_inforp info_ptr)) 2397 #endif 2398 2399 # ifdef PNG_pHYs_SUPPORTED 2400 PNG_EXPORT(198, png_uint_32, png_get_pHYs_dpi, (png_const_structrp png_ptr, 2401 png_const_inforp info_ptr, png_uint_32 *res_x, png_uint_32 *res_y, 2402 int *unit_type)); 2403 # endif /* pHYs */ 2404 #endif /* INCH_CONVERSIONS */ 2405 2406 /* Added in libpng-1.4.0 */ 2407 #ifdef PNG_IO_STATE_SUPPORTED 2408 PNG_EXPORT(199, png_uint_32, png_get_io_state, (png_const_structrp png_ptr)); 2409 2410 /* Removed from libpng 1.6; use png_get_io_chunk_type. */ 2411 PNG_REMOVED(200, png_const_bytep, png_get_io_chunk_name, (png_structrp png_ptr), 2412 PNG_DEPRECATED) 2413 2414 PNG_EXPORT(216, png_uint_32, png_get_io_chunk_type, 2415 (png_const_structrp png_ptr)); 2416 2417 /* The flags returned by png_get_io_state() are the following: */ 2418 # define PNG_IO_NONE 0x0000 /* no I/O at this moment */ 2419 # define PNG_IO_READING 0x0001 /* currently reading */ 2420 # define PNG_IO_WRITING 0x0002 /* currently writing */ 2421 # define PNG_IO_SIGNATURE 0x0010 /* currently at the file signature */ 2422 # define PNG_IO_CHUNK_HDR 0x0020 /* currently at the chunk header */ 2423 # define PNG_IO_CHUNK_DATA 0x0040 /* currently at the chunk data */ 2424 # define PNG_IO_CHUNK_CRC 0x0080 /* currently at the chunk crc */ 2425 # define PNG_IO_MASK_OP 0x000f /* current operation: reading/writing */ 2426 # define PNG_IO_MASK_LOC 0x00f0 /* current location: sig/hdr/data/crc */ 2427 #endif /* IO_STATE */ 2428 2429 /* Interlace support. The following macros are always defined so that if 2430 * libpng interlace handling is turned off the macros may be used to handle 2431 * interlaced images within the application. 2432 */ 2433 #define PNG_INTERLACE_ADAM7_PASSES 7 2434 2435 /* Two macros to return the first row and first column of the original, 2436 * full, image which appears in a given pass. 'pass' is in the range 0 2437 * to 6 and the result is in the range 0 to 7. 2438 */ 2439 #define PNG_PASS_START_ROW(pass) (((1&~(pass))<<(3-((pass)>>1)))&7) 2440 #define PNG_PASS_START_COL(pass) (((1& (pass))<<(3-(((pass)+1)>>1)))&7) 2441 2442 /* A macro to return the offset between pixels in the output row for a pair of 2443 * pixels in the input - effectively the inverse of the 'COL_SHIFT' macro that 2444 * follows. Note that ROW_OFFSET is the offset from one row to the next whereas 2445 * COL_OFFSET is from one column to the next, within a row. 2446 */ 2447 #define PNG_PASS_ROW_OFFSET(pass) ((pass)>2?(8>>(((pass)-1)>>1)):8) 2448 #define PNG_PASS_COL_OFFSET(pass) (1<<((7-(pass))>>1)) 2449 2450 /* Two macros to help evaluate the number of rows or columns in each 2451 * pass. This is expressed as a shift - effectively log2 of the number or 2452 * rows or columns in each 8x8 tile of the original image. 2453 */ 2454 #define PNG_PASS_ROW_SHIFT(pass) ((pass)>2?(8-(pass))>>1:3) 2455 #define PNG_PASS_COL_SHIFT(pass) ((pass)>1?(7-(pass))>>1:3) 2456 2457 /* Hence two macros to determine the number of rows or columns in a given 2458 * pass of an image given its height or width. In fact these macros may 2459 * return non-zero even though the sub-image is empty, because the other 2460 * dimension may be empty for a small image. 2461 */ 2462 #define PNG_PASS_ROWS(height, pass) (((height)+(((1<<PNG_PASS_ROW_SHIFT(pass))\ 2463 -1)-PNG_PASS_START_ROW(pass)))>>PNG_PASS_ROW_SHIFT(pass)) 2464 #define PNG_PASS_COLS(width, pass) (((width)+(((1<<PNG_PASS_COL_SHIFT(pass))\ 2465 -1)-PNG_PASS_START_COL(pass)))>>PNG_PASS_COL_SHIFT(pass)) 2466 2467 /* For the reader row callbacks (both progressive and sequential) it is 2468 * necessary to find the row in the output image given a row in an interlaced 2469 * image, so two more macros: 2470 */ 2471 #define PNG_ROW_FROM_PASS_ROW(y_in, pass) \ 2472 (((y_in)<<PNG_PASS_ROW_SHIFT(pass))+PNG_PASS_START_ROW(pass)) 2473 #define PNG_COL_FROM_PASS_COL(x_in, pass) \ 2474 (((x_in)<<PNG_PASS_COL_SHIFT(pass))+PNG_PASS_START_COL(pass)) 2475 2476 /* Two macros which return a boolean (0 or 1) saying whether the given row 2477 * or column is in a particular pass. These use a common utility macro that 2478 * returns a mask for a given pass - the offset 'off' selects the row or 2479 * column version. The mask has the appropriate bit set for each column in 2480 * the tile. 2481 */ 2482 #define PNG_PASS_MASK(pass,off) ( \ 2483 ((0x110145AF>>(((7-(off))-(pass))<<2)) & 0xF) | \ 2484 ((0x01145AF0>>(((7-(off))-(pass))<<2)) & 0xF0)) 2485 2486 #define PNG_ROW_IN_INTERLACE_PASS(y, pass) \ 2487 ((PNG_PASS_MASK(pass,0) >> ((y)&7)) & 1) 2488 #define PNG_COL_IN_INTERLACE_PASS(x, pass) \ 2489 ((PNG_PASS_MASK(pass,1) >> ((x)&7)) & 1) 2490 2491 #ifdef PNG_READ_COMPOSITE_NODIV_SUPPORTED 2492 /* With these routines we avoid an integer divide, which will be slower on 2493 * most machines. However, it does take more operations than the corresponding 2494 * divide method, so it may be slower on a few RISC systems. There are two 2495 * shifts (by 8 or 16 bits) and an addition, versus a single integer divide. 2496 * 2497 * Note that the rounding factors are NOT supposed to be the same! 128 and 2498 * 32768 are correct for the NODIV code; 127 and 32767 are correct for the 2499 * standard method. 2500 * 2501 * [Optimized code by Greg Roelofs and Mark Adler...blame us for bugs. :-) ] 2502 */ 2503 2504 /* fg and bg should be in `gamma 1.0' space; alpha is the opacity */ 2505 2506 # define png_composite(composite, fg, alpha, bg) \ 2507 { \ 2508 png_uint_16 temp = (png_uint_16)((png_uint_16)(fg) \ 2509 * (png_uint_16)(alpha) \ 2510 + (png_uint_16)(bg)*(png_uint_16)(255 \ 2511 - (png_uint_16)(alpha)) + 128); \ 2512 (composite) = (png_byte)(((temp + (temp >> 8)) >> 8) & 0xff); \ 2513 } 2514 2515 # define png_composite_16(composite, fg, alpha, bg) \ 2516 { \ 2517 png_uint_32 temp = (png_uint_32)((png_uint_32)(fg) \ 2518 * (png_uint_32)(alpha) \ 2519 + (png_uint_32)(bg)*(65535 \ 2520 - (png_uint_32)(alpha)) + 32768); \ 2521 (composite) = (png_uint_16)(0xffff & ((temp + (temp >> 16)) >> 16)); \ 2522 } 2523 2524 #else /* Standard method using integer division */ 2525 2526 # define png_composite(composite, fg, alpha, bg) \ 2527 (composite) = \ 2528 (png_byte)(0xff & (((png_uint_16)(fg) * (png_uint_16)(alpha) + \ 2529 (png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) + \ 2530 127) / 255)) 2531 2532 # define png_composite_16(composite, fg, alpha, bg) \ 2533 (composite) = \ 2534 (png_uint_16)(0xffff & (((png_uint_32)(fg) * (png_uint_32)(alpha) + \ 2535 (png_uint_32)(bg)*(png_uint_32)(65535 - (png_uint_32)(alpha)) + \ 2536 32767) / 65535)) 2537 #endif /* READ_COMPOSITE_NODIV */ 2538 2539 #ifdef PNG_READ_INT_FUNCTIONS_SUPPORTED 2540 PNG_EXPORT(201, png_uint_32, png_get_uint_32, (png_const_bytep buf)); 2541 PNG_EXPORT(202, png_uint_16, png_get_uint_16, (png_const_bytep buf)); 2542 PNG_EXPORT(203, png_int_32, png_get_int_32, (png_const_bytep buf)); 2543 #endif 2544 2545 PNG_EXPORT(204, png_uint_32, png_get_uint_31, (png_const_structrp png_ptr, 2546 png_const_bytep buf)); 2547 /* No png_get_int_16 -- may be added if there's a real need for it. */ 2548 2549 /* Place a 32-bit number into a buffer in PNG byte order (big-endian). */ 2550 #ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED 2551 PNG_EXPORT(205, void, png_save_uint_32, (png_bytep buf, png_uint_32 i)); 2552 #endif 2553 #ifdef PNG_SAVE_INT_32_SUPPORTED 2554 PNG_EXPORT(206, void, png_save_int_32, (png_bytep buf, png_int_32 i)); 2555 #endif 2556 2557 /* Place a 16-bit number into a buffer in PNG byte order. 2558 * The parameter is declared unsigned int, not png_uint_16, 2559 * just to avoid potential problems on pre-ANSI C compilers. 2560 */ 2561 #ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED 2562 PNG_EXPORT(207, void, png_save_uint_16, (png_bytep buf, unsigned int i)); 2563 /* No png_save_int_16 -- may be added if there's a real need for it. */ 2564 #endif 2565 2566 #ifdef PNG_USE_READ_MACROS 2567 /* Inline macros to do direct reads of bytes from the input buffer. 2568 * The png_get_int_32() routine assumes we are using two's complement 2569 * format for negative values, which is almost certainly true. 2570 */ 2571 # define PNG_get_uint_32(buf) \ 2572 (((png_uint_32)(*(buf)) << 24) + \ 2573 ((png_uint_32)(*((buf) + 1)) << 16) + \ 2574 ((png_uint_32)(*((buf) + 2)) << 8) + \ 2575 ((png_uint_32)(*((buf) + 3)))) 2576 2577 /* From libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the 2578 * function) incorrectly returned a value of type png_uint_32. 2579 */ 2580 # define PNG_get_uint_16(buf) \ 2581 ((png_uint_16) \ 2582 (((unsigned int)(*(buf)) << 8) + \ 2583 ((unsigned int)(*((buf) + 1))))) 2584 2585 # define PNG_get_int_32(buf) \ 2586 ((png_int_32)((*(buf) & 0x80) \ 2587 ? -((png_int_32)(((png_get_uint_32(buf)^0xffffffffU)+1U)&0x7fffffffU)) \ 2588 : (png_int_32)png_get_uint_32(buf))) 2589 2590 /* If PNG_PREFIX is defined the same thing as below happens in pnglibconf.h, 2591 * but defining a macro name prefixed with PNG_PREFIX. 2592 */ 2593 # ifndef PNG_PREFIX 2594 # define png_get_uint_32(buf) PNG_get_uint_32(buf) 2595 # define png_get_uint_16(buf) PNG_get_uint_16(buf) 2596 # define png_get_int_32(buf) PNG_get_int_32(buf) 2597 # endif 2598 #else 2599 # ifdef PNG_PREFIX 2600 /* No macros; revert to the (redefined) function */ 2601 # define PNG_get_uint_32 (png_get_uint_32) 2602 # define PNG_get_uint_16 (png_get_uint_16) 2603 # define PNG_get_int_32 (png_get_int_32) 2604 # endif 2605 #endif 2606 2607 #ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED 2608 PNG_EXPORT(242, void, png_set_check_for_invalid_index, 2609 (png_structrp png_ptr, int allowed)); 2610 # ifdef PNG_GET_PALETTE_MAX_SUPPORTED 2611 PNG_EXPORT(243, int, png_get_palette_max, (png_const_structp png_ptr, 2612 png_const_infop info_ptr)); 2613 # endif 2614 #endif /* CHECK_FOR_INVALID_INDEX */ 2615 2616 /******************************************************************************* 2617 * Section 5: SIMPLIFIED API 2618 ******************************************************************************* 2619 * 2620 * Please read the documentation in libpng-manual.txt (TODO: write said 2621 * documentation) if you don't understand what follows. 2622 * 2623 * The simplified API hides the details of both libpng and the PNG file format 2624 * itself. It allows PNG files to be read into a very limited number of 2625 * in-memory bitmap formats or to be written from the same formats. If these 2626 * formats do not accommodate your needs then you can, and should, use the more 2627 * sophisticated APIs above - these support a wide variety of in-memory formats 2628 * and a wide variety of sophisticated transformations to those formats as well 2629 * as a wide variety of APIs to manipulate ancillary information. 2630 * 2631 * To read a PNG file using the simplified API: 2632 * 2633 * 1) Declare a 'png_image' structure (see below) on the stack, set the 2634 * version field to PNG_IMAGE_VERSION and the 'opaque' pointer to NULL 2635 * (this is REQUIRED, your program may crash if you don't do it.) 2636 * 2) Call the appropriate png_image_begin_read... function. 2637 * 3) Set the png_image 'format' member to the required sample format. 2638 * 4) Allocate a buffer for the image and, if required, the color-map. 2639 * 5) Call png_image_finish_read to read the image and, if required, the 2640 * color-map into your buffers. 2641 * 2642 * There are no restrictions on the format of the PNG input itself; all valid 2643 * color types, bit depths, and interlace methods are acceptable, and the 2644 * input image is transformed as necessary to the requested in-memory format 2645 * during the png_image_finish_read() step. The only caveat is that if you 2646 * request a color-mapped image from a PNG that is full-color or makes 2647 * complex use of an alpha channel the transformation is extremely lossy and the 2648 * result may look terrible. 2649 * 2650 * To write a PNG file using the simplified API: 2651 * 2652 * 1) Declare a 'png_image' structure on the stack and memset() it to all zero. 2653 * 2) Initialize the members of the structure that describe the image, setting 2654 * the 'format' member to the format of the image samples. 2655 * 3) Call the appropriate png_image_write... function with a pointer to the 2656 * image and, if necessary, the color-map to write the PNG data. 2657 * 2658 * png_image is a structure that describes the in-memory format of an image 2659 * when it is being read or defines the in-memory format of an image that you 2660 * need to write: 2661 */ 2662 #if defined(PNG_SIMPLIFIED_READ_SUPPORTED) || \ 2663 defined(PNG_SIMPLIFIED_WRITE_SUPPORTED) 2664 2665 #define PNG_IMAGE_VERSION 1 2666 2667 typedef struct png_control *png_controlp; 2668 typedef struct 2669 { 2670 png_controlp opaque; /* Initialize to NULL, free with png_image_free */ 2671 png_uint_32 version; /* Set to PNG_IMAGE_VERSION */ 2672 png_uint_32 width; /* Image width in pixels (columns) */ 2673 png_uint_32 height; /* Image height in pixels (rows) */ 2674 png_uint_32 format; /* Image format as defined below */ 2675 png_uint_32 flags; /* A bit mask containing informational flags */ 2676 png_uint_32 colormap_entries; 2677 /* Number of entries in the color-map */ 2678 2679 /* In the event of an error or warning the following field will be set to a 2680 * non-zero value and the 'message' field will contain a '\0' terminated 2681 * string with the libpng error or warning message. If both warnings and 2682 * an error were encountered, only the error is recorded. If there 2683 * are multiple warnings, only the first one is recorded. 2684 * 2685 * The upper 30 bits of this value are reserved, the low two bits contain 2686 * a value as follows: 2687 */ 2688 # define PNG_IMAGE_WARNING 1 2689 # define PNG_IMAGE_ERROR 2 2690 /* 2691 * The result is a two-bit code such that a value more than 1 indicates 2692 * a failure in the API just called: 2693 * 2694 * 0 - no warning or error 2695 * 1 - warning 2696 * 2 - error 2697 * 3 - error preceded by warning 2698 */ 2699 # define PNG_IMAGE_FAILED(png_cntrl) ((((png_cntrl).warning_or_error)&0x03)>1) 2700 2701 png_uint_32 warning_or_error; 2702 2703 char message[64]; 2704 } png_image, *png_imagep; 2705 2706 /* The samples of the image have one to four channels whose components have 2707 * original values in the range 0 to 1.0: 2708 * 2709 * 1: A single gray or luminance channel (G). 2710 * 2: A gray/luminance channel and an alpha channel (GA). 2711 * 3: Three red, green, blue color channels (RGB). 2712 * 4: Three color channels and an alpha channel (RGBA). 2713 * 2714 * The components are encoded in one of two ways: 2715 * 2716 * a) As a small integer, value 0..255, contained in a single byte. For the 2717 * alpha channel the original value is simply value/255. For the color or 2718 * luminance channels the value is encoded according to the sRGB specification 2719 * and matches the 8-bit format expected by typical display devices. 2720 * 2721 * The color/gray channels are not scaled (pre-multiplied) by the alpha 2722 * channel and are suitable for passing to color management software. 2723 * 2724 * b) As a value in the range 0..65535, contained in a 2-byte integer. All 2725 * channels can be converted to the original value by dividing by 65535; all 2726 * channels are linear. Color channels use the RGB encoding (RGB end-points) of 2727 * the sRGB specification. This encoding is identified by the 2728 * PNG_FORMAT_FLAG_LINEAR flag below. 2729 * 2730 * When the simplified API needs to convert between sRGB and linear colorspaces, 2731 * the actual sRGB transfer curve defined in the sRGB specification (see the 2732 * article at <https://en.wikipedia.org/wiki/SRGB>) is used, not the gamma=1/2.2 2733 * approximation used elsewhere in libpng. 2734 * 2735 * When an alpha channel is present it is expected to denote pixel coverage 2736 * of the color or luminance channels and is returned as an associated alpha 2737 * channel: the color/gray channels are scaled (pre-multiplied) by the alpha 2738 * value. 2739 * 2740 * The samples are either contained directly in the image data, between 1 and 8 2741 * bytes per pixel according to the encoding, or are held in a color-map indexed 2742 * by bytes in the image data. In the case of a color-map the color-map entries 2743 * are individual samples, encoded as above, and the image data has one byte per 2744 * pixel to select the relevant sample from the color-map. 2745 */ 2746 2747 /* PNG_FORMAT_* 2748 * 2749 * #defines to be used in png_image::format. Each #define identifies a 2750 * particular layout of sample data and, if present, alpha values. There are 2751 * separate defines for each of the two component encodings. 2752 * 2753 * A format is built up using single bit flag values. All combinations are 2754 * valid. Formats can be built up from the flag values or you can use one of 2755 * the predefined values below. When testing formats always use the FORMAT_FLAG 2756 * macros to test for individual features - future versions of the library may 2757 * add new flags. 2758 * 2759 * When reading or writing color-mapped images the format should be set to the 2760 * format of the entries in the color-map then png_image_{read,write}_colormap 2761 * called to read or write the color-map and set the format correctly for the 2762 * image data. Do not set the PNG_FORMAT_FLAG_COLORMAP bit directly! 2763 * 2764 * NOTE: libpng can be built with particular features disabled. If you see 2765 * compiler errors because the definition of one of the following flags has been 2766 * compiled out it is because libpng does not have the required support. It is 2767 * possible, however, for the libpng configuration to enable the format on just 2768 * read or just write; in that case you may see an error at run time. You can 2769 * guard against this by checking for the definition of the appropriate 2770 * "_SUPPORTED" macro, one of: 2771 * 2772 * PNG_SIMPLIFIED_{READ,WRITE}_{BGR,AFIRST}_SUPPORTED 2773 */ 2774 #define PNG_FORMAT_FLAG_ALPHA 0x01U /* format with an alpha channel */ 2775 #define PNG_FORMAT_FLAG_COLOR 0x02U /* color format: otherwise grayscale */ 2776 #define PNG_FORMAT_FLAG_LINEAR 0x04U /* 2-byte channels else 1-byte */ 2777 #define PNG_FORMAT_FLAG_COLORMAP 0x08U /* image data is color-mapped */ 2778 2779 #ifdef PNG_FORMAT_BGR_SUPPORTED 2780 # define PNG_FORMAT_FLAG_BGR 0x10U /* BGR colors, else order is RGB */ 2781 #endif 2782 2783 #ifdef PNG_FORMAT_AFIRST_SUPPORTED 2784 # define PNG_FORMAT_FLAG_AFIRST 0x20U /* alpha channel comes first */ 2785 #endif 2786 2787 #define PNG_FORMAT_FLAG_ASSOCIATED_ALPHA 0x40U /* alpha channel is associated */ 2788 2789 /* Commonly used formats have predefined macros. 2790 * 2791 * First the single byte (sRGB) formats: 2792 */ 2793 #define PNG_FORMAT_GRAY 0 2794 #define PNG_FORMAT_GA PNG_FORMAT_FLAG_ALPHA 2795 #define PNG_FORMAT_AG (PNG_FORMAT_GA|PNG_FORMAT_FLAG_AFIRST) 2796 #define PNG_FORMAT_RGB PNG_FORMAT_FLAG_COLOR 2797 #define PNG_FORMAT_BGR (PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_BGR) 2798 #define PNG_FORMAT_RGBA (PNG_FORMAT_RGB|PNG_FORMAT_FLAG_ALPHA) 2799 #define PNG_FORMAT_ARGB (PNG_FORMAT_RGBA|PNG_FORMAT_FLAG_AFIRST) 2800 #define PNG_FORMAT_BGRA (PNG_FORMAT_BGR|PNG_FORMAT_FLAG_ALPHA) 2801 #define PNG_FORMAT_ABGR (PNG_FORMAT_BGRA|PNG_FORMAT_FLAG_AFIRST) 2802 2803 /* Then the linear 2-byte formats. When naming these "Y" is used to 2804 * indicate a luminance (gray) channel. 2805 */ 2806 #define PNG_FORMAT_LINEAR_Y PNG_FORMAT_FLAG_LINEAR 2807 #define PNG_FORMAT_LINEAR_Y_ALPHA (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_ALPHA) 2808 #define PNG_FORMAT_LINEAR_RGB (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR) 2809 #define PNG_FORMAT_LINEAR_RGB_ALPHA \ 2810 (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_ALPHA) 2811 2812 /* With color-mapped formats the image data is one byte for each pixel, the byte 2813 * is an index into the color-map which is formatted as above. To obtain a 2814 * color-mapped format it is sufficient just to add the PNG_FOMAT_FLAG_COLORMAP 2815 * to one of the above definitions, or you can use one of the definitions below. 2816 */ 2817 #define PNG_FORMAT_RGB_COLORMAP (PNG_FORMAT_RGB|PNG_FORMAT_FLAG_COLORMAP) 2818 #define PNG_FORMAT_BGR_COLORMAP (PNG_FORMAT_BGR|PNG_FORMAT_FLAG_COLORMAP) 2819 #define PNG_FORMAT_RGBA_COLORMAP (PNG_FORMAT_RGBA|PNG_FORMAT_FLAG_COLORMAP) 2820 #define PNG_FORMAT_ARGB_COLORMAP (PNG_FORMAT_ARGB|PNG_FORMAT_FLAG_COLORMAP) 2821 #define PNG_FORMAT_BGRA_COLORMAP (PNG_FORMAT_BGRA|PNG_FORMAT_FLAG_COLORMAP) 2822 #define PNG_FORMAT_ABGR_COLORMAP (PNG_FORMAT_ABGR|PNG_FORMAT_FLAG_COLORMAP) 2823 2824 /* PNG_IMAGE macros 2825 * 2826 * These are convenience macros to derive information from a png_image 2827 * structure. The PNG_IMAGE_SAMPLE_ macros return values appropriate to the 2828 * actual image sample values - either the entries in the color-map or the 2829 * pixels in the image. The PNG_IMAGE_PIXEL_ macros return corresponding values 2830 * for the pixels and will always return 1 for color-mapped formats. The 2831 * remaining macros return information about the rows in the image and the 2832 * complete image. 2833 * 2834 * NOTE: All the macros that take a png_image::format parameter are compile time 2835 * constants if the format parameter is, itself, a constant. Therefore these 2836 * macros can be used in array declarations and case labels where required. 2837 * Similarly the macros are also pre-processor constants (sizeof is not used) so 2838 * they can be used in #if tests. 2839 * 2840 * First the information about the samples. 2841 */ 2842 #define PNG_IMAGE_SAMPLE_CHANNELS(fmt)\ 2843 (((fmt)&(PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_ALPHA))+1) 2844 /* Return the total number of channels in a given format: 1..4 */ 2845 2846 #define PNG_IMAGE_SAMPLE_COMPONENT_SIZE(fmt)\ 2847 ((((fmt) & PNG_FORMAT_FLAG_LINEAR) >> 2)+1) 2848 /* Return the size in bytes of a single component of a pixel or color-map 2849 * entry (as appropriate) in the image: 1 or 2. 2850 */ 2851 2852 #define PNG_IMAGE_SAMPLE_SIZE(fmt)\ 2853 (PNG_IMAGE_SAMPLE_CHANNELS(fmt) * PNG_IMAGE_SAMPLE_COMPONENT_SIZE(fmt)) 2854 /* This is the size of the sample data for one sample. If the image is 2855 * color-mapped it is the size of one color-map entry (and image pixels are 2856 * one byte in size), otherwise it is the size of one image pixel. 2857 */ 2858 2859 #define PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(fmt)\ 2860 (PNG_IMAGE_SAMPLE_CHANNELS(fmt) * 256) 2861 /* The maximum size of the color-map required by the format expressed in a 2862 * count of components. This can be used to compile-time allocate a 2863 * color-map: 2864 * 2865 * png_uint_16 colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(linear_fmt)]; 2866 * 2867 * png_byte colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(sRGB_fmt)]; 2868 * 2869 * Alternatively use the PNG_IMAGE_COLORMAP_SIZE macro below to use the 2870 * information from one of the png_image_begin_read_ APIs and dynamically 2871 * allocate the required memory. 2872 */ 2873 2874 /* Corresponding information about the pixels */ 2875 #define PNG_IMAGE_PIXEL_(test,fmt)\ 2876 (((fmt)&PNG_FORMAT_FLAG_COLORMAP)?1:test(fmt)) 2877 2878 #define PNG_IMAGE_PIXEL_CHANNELS(fmt)\ 2879 PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_CHANNELS,fmt) 2880 /* The number of separate channels (components) in a pixel; 1 for a 2881 * color-mapped image. 2882 */ 2883 2884 #define PNG_IMAGE_PIXEL_COMPONENT_SIZE(fmt)\ 2885 PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_COMPONENT_SIZE,fmt) 2886 /* The size, in bytes, of each component in a pixel; 1 for a color-mapped 2887 * image. 2888 */ 2889 2890 #define PNG_IMAGE_PIXEL_SIZE(fmt) PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_SIZE,fmt) 2891 /* The size, in bytes, of a complete pixel; 1 for a color-mapped image. */ 2892 2893 /* Information about the whole row, or whole image */ 2894 #define PNG_IMAGE_ROW_STRIDE(image)\ 2895 (PNG_IMAGE_PIXEL_CHANNELS((image).format) * (image).width) 2896 /* Return the total number of components in a single row of the image; this 2897 * is the minimum 'row stride', the minimum count of components between each 2898 * row. For a color-mapped image this is the minimum number of bytes in a 2899 * row. 2900 * 2901 * WARNING: this macro overflows for some images with more than one component 2902 * and very large image widths. libpng will refuse to process an image where 2903 * this macro would overflow. 2904 */ 2905 2906 #define PNG_IMAGE_BUFFER_SIZE(image, row_stride)\ 2907 (PNG_IMAGE_PIXEL_COMPONENT_SIZE((image).format)*(image).height*(row_stride)) 2908 /* Return the size, in bytes, of an image buffer given a png_image and a row 2909 * stride - the number of components to leave space for in each row. 2910 * 2911 * WARNING: this macro overflows a 32-bit integer for some large PNG images, 2912 * libpng will refuse to process an image where such an overflow would occur. 2913 */ 2914 2915 #define PNG_IMAGE_SIZE(image)\ 2916 PNG_IMAGE_BUFFER_SIZE(image, PNG_IMAGE_ROW_STRIDE(image)) 2917 /* Return the size, in bytes, of the image in memory given just a png_image; 2918 * the row stride is the minimum stride required for the image. 2919 */ 2920 2921 #define PNG_IMAGE_COLORMAP_SIZE(image)\ 2922 (PNG_IMAGE_SAMPLE_SIZE((image).format) * (image).colormap_entries) 2923 /* Return the size, in bytes, of the color-map of this image. If the image 2924 * format is not a color-map format this will return a size sufficient for 2925 * 256 entries in the given format; check PNG_FORMAT_FLAG_COLORMAP if 2926 * you don't want to allocate a color-map in this case. 2927 */ 2928 2929 /* PNG_IMAGE_FLAG_* 2930 * 2931 * Flags containing additional information about the image are held in the 2932 * 'flags' field of png_image. 2933 */ 2934 #define PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB 0x01 2935 /* This indicates that the RGB values of the in-memory bitmap do not 2936 * correspond to the red, green and blue end-points defined by sRGB. 2937 */ 2938 2939 #define PNG_IMAGE_FLAG_FAST 0x02 2940 /* On write emphasise speed over compression; the resultant PNG file will be 2941 * larger but will be produced significantly faster, particular for large 2942 * images. Do not use this option for images which will be distributed, only 2943 * used it when producing intermediate files that will be read back in 2944 * repeatedly. For a typical 24-bit image the option will double the read 2945 * speed at the cost of increasing the image size by 25%, however for many 2946 * more compressible images the PNG file can be 10 times larger with only a 2947 * slight speed gain. 2948 */ 2949 2950 #define PNG_IMAGE_FLAG_16BIT_sRGB 0x04 2951 /* On read if the image is a 16-bit per component image and there is no gAMA 2952 * or sRGB chunk assume that the components are sRGB encoded. Notice that 2953 * images output by the simplified API always have gamma information; setting 2954 * this flag only affects the interpretation of 16-bit images from an 2955 * external source. It is recommended that the application expose this flag 2956 * to the user; the user can normally easily recognize the difference between 2957 * linear and sRGB encoding. This flag has no effect on write - the data 2958 * passed to the write APIs must have the correct encoding (as defined 2959 * above.) 2960 * 2961 * If the flag is not set (the default) input 16-bit per component data is 2962 * assumed to be linear. 2963 * 2964 * NOTE: the flag can only be set after the png_image_begin_read_ call, 2965 * because that call initializes the 'flags' field. 2966 */ 2967 2968 #ifdef PNG_SIMPLIFIED_READ_SUPPORTED 2969 /* READ APIs 2970 * --------- 2971 * 2972 * The png_image passed to the read APIs must have been initialized by setting 2973 * the png_controlp field 'opaque' to NULL (or, safer, memset the whole thing.) 2974 */ 2975 #ifdef PNG_STDIO_SUPPORTED 2976 PNG_EXPORT(234, int, png_image_begin_read_from_file, (png_imagep image, 2977 const char *file_name)); 2978 /* The named file is opened for read and the image header is filled in 2979 * from the PNG header in the file. 2980 */ 2981 2982 PNG_EXPORT(235, int, png_image_begin_read_from_stdio, (png_imagep image, 2983 FILE* file)); 2984 /* The PNG header is read from the stdio FILE object. */ 2985 #endif /* STDIO */ 2986 2987 PNG_EXPORT(236, int, png_image_begin_read_from_memory, (png_imagep image, 2988 png_const_voidp memory, size_t size)); 2989 /* The PNG header is read from the given memory buffer. */ 2990 2991 PNG_EXPORT(237, int, png_image_finish_read, (png_imagep image, 2992 png_const_colorp background, void *buffer, png_int_32 row_stride, 2993 void *colormap)); 2994 /* Finish reading the image into the supplied buffer and clean up the 2995 * png_image structure. 2996 * 2997 * row_stride is the step, in byte or 2-byte units as appropriate, 2998 * between adjacent rows. A positive stride indicates that the top-most row 2999 * is first in the buffer - the normal top-down arrangement. A negative 3000 * stride indicates that the bottom-most row is first in the buffer. 3001 * 3002 * background need only be supplied if an alpha channel must be removed from 3003 * a png_byte format and the removal is to be done by compositing on a solid 3004 * color; otherwise it may be NULL and any composition will be done directly 3005 * onto the buffer. The value is an sRGB color to use for the background, 3006 * for grayscale output the green channel is used. 3007 * 3008 * background must be supplied when an alpha channel must be removed from a 3009 * single byte color-mapped output format, in other words if: 3010 * 3011 * 1) The original format from png_image_begin_read_from_* had 3012 * PNG_FORMAT_FLAG_ALPHA set. 3013 * 2) The format set by the application does not. 3014 * 3) The format set by the application has PNG_FORMAT_FLAG_COLORMAP set and 3015 * PNG_FORMAT_FLAG_LINEAR *not* set. 3016 * 3017 * For linear output removing the alpha channel is always done by compositing 3018 * on black and background is ignored. 3019 * 3020 * colormap must be supplied when PNG_FORMAT_FLAG_COLORMAP is set. It must 3021 * be at least the size (in bytes) returned by PNG_IMAGE_COLORMAP_SIZE. 3022 * image->colormap_entries will be updated to the actual number of entries 3023 * written to the colormap; this may be less than the original value. 3024 */ 3025 3026 PNG_EXPORT(238, void, png_image_free, (png_imagep image)); 3027 /* Free any data allocated by libpng in image->opaque, setting the pointer to 3028 * NULL. May be called at any time after the structure is initialized. 3029 */ 3030 #endif /* SIMPLIFIED_READ */ 3031 3032 #ifdef PNG_SIMPLIFIED_WRITE_SUPPORTED 3033 /* WRITE APIS 3034 * ---------- 3035 * For write you must initialize a png_image structure to describe the image to 3036 * be written. To do this use memset to set the whole structure to 0 then 3037 * initialize fields describing your image. 3038 * 3039 * version: must be set to PNG_IMAGE_VERSION 3040 * opaque: must be initialized to NULL 3041 * width: image width in pixels 3042 * height: image height in rows 3043 * format: the format of the data (image and color-map) you wish to write 3044 * flags: set to 0 unless one of the defined flags applies; set 3045 * PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB for color format images where the RGB 3046 * values do not correspond to the colors in sRGB. 3047 * colormap_entries: set to the number of entries in the color-map (0 to 256) 3048 */ 3049 #ifdef PNG_SIMPLIFIED_WRITE_STDIO_SUPPORTED 3050 PNG_EXPORT(239, int, png_image_write_to_file, (png_imagep image, 3051 const char *file, int convert_to_8bit, const void *buffer, 3052 png_int_32 row_stride, const void *colormap)); 3053 /* Write the image to the named file. */ 3054 3055 PNG_EXPORT(240, int, png_image_write_to_stdio, (png_imagep image, FILE *file, 3056 int convert_to_8_bit, const void *buffer, png_int_32 row_stride, 3057 const void *colormap)); 3058 /* Write the image to the given (FILE*). */ 3059 #endif /* SIMPLIFIED_WRITE_STDIO */ 3060 3061 /* With all write APIs if image is in one of the linear formats with 16-bit 3062 * data then setting convert_to_8_bit will cause the output to be an 8-bit PNG 3063 * gamma encoded according to the sRGB specification, otherwise a 16-bit linear 3064 * encoded PNG file is written. 3065 * 3066 * With color-mapped data formats the colormap parameter point to a color-map 3067 * with at least image->colormap_entries encoded in the specified format. If 3068 * the format is linear the written PNG color-map will be converted to sRGB 3069 * regardless of the convert_to_8_bit flag. 3070 * 3071 * With all APIs row_stride is handled as in the read APIs - it is the spacing 3072 * from one row to the next in component sized units (1 or 2 bytes) and if 3073 * negative indicates a bottom-up row layout in the buffer. If row_stride is 3074 * zero, libpng will calculate it for you from the image width and number of 3075 * channels. 3076 * 3077 * Note that the write API does not support interlacing, sub-8-bit pixels or 3078 * most ancillary chunks. If you need to write text chunks (e.g. for copyright 3079 * notices) you need to use one of the other APIs. 3080 */ 3081 3082 PNG_EXPORT(245, int, png_image_write_to_memory, (png_imagep image, void *memory, 3083 png_alloc_size_t * PNG_RESTRICT memory_bytes, int convert_to_8_bit, 3084 const void *buffer, png_int_32 row_stride, const void *colormap)); 3085 /* Write the image to the given memory buffer. The function both writes the 3086 * whole PNG data stream to *memory and updates *memory_bytes with the count 3087 * of bytes written. 3088 * 3089 * 'memory' may be NULL. In this case *memory_bytes is not read however on 3090 * success the number of bytes which would have been written will still be 3091 * stored in *memory_bytes. On failure *memory_bytes will contain 0. 3092 * 3093 * If 'memory' is not NULL it must point to memory[*memory_bytes] of 3094 * writeable memory. 3095 * 3096 * If the function returns success memory[*memory_bytes] (if 'memory' is not 3097 * NULL) contains the written PNG data. *memory_bytes will always be less 3098 * than or equal to the original value. 3099 * 3100 * If the function returns false and *memory_bytes was not changed an error 3101 * occurred during write. If *memory_bytes was changed, or is not 0 if 3102 * 'memory' was NULL, the write would have succeeded but for the memory 3103 * buffer being too small. *memory_bytes contains the required number of 3104 * bytes and will be bigger that the original value. 3105 */ 3106 3107 #define png_image_write_get_memory_size(image, size, convert_to_8_bit, buffer,\ 3108 row_stride, colormap)\ 3109 png_image_write_to_memory(&(image), 0, &(size), convert_to_8_bit, buffer,\ 3110 row_stride, colormap) 3111 /* Return the amount of memory in 'size' required to compress this image. 3112 * The png_image structure 'image' must be filled in as in the above 3113 * function and must not be changed before the actual write call, the buffer 3114 * and all other parameters must also be identical to that in the final 3115 * write call. The 'size' variable need not be initialized. 3116 * 3117 * NOTE: the macro returns true/false, if false is returned 'size' will be 3118 * set to zero and the write failed and probably will fail if tried again. 3119 */ 3120 3121 /* You can pre-allocate the buffer by making sure it is of sufficient size 3122 * regardless of the amount of compression achieved. The buffer size will 3123 * always be bigger than the original image and it will never be filled. The 3124 * following macros are provided to assist in allocating the buffer. 3125 */ 3126 #define PNG_IMAGE_DATA_SIZE(image) (PNG_IMAGE_SIZE(image)+(image).height) 3127 /* The number of uncompressed bytes in the PNG byte encoding of the image; 3128 * uncompressing the PNG IDAT data will give this number of bytes. 3129 * 3130 * NOTE: while PNG_IMAGE_SIZE cannot overflow for an image in memory this 3131 * macro can because of the extra bytes used in the PNG byte encoding. You 3132 * need to avoid this macro if your image size approaches 2^30 in width or 3133 * height. The same goes for the remainder of these macros; they all produce 3134 * bigger numbers than the actual in-memory image size. 3135 */ 3136 #ifndef PNG_ZLIB_MAX_SIZE 3137 # define PNG_ZLIB_MAX_SIZE(b) ((b)+(((b)+7U)>>3)+(((b)+63U)>>6)+11U) 3138 /* An upper bound on the number of compressed bytes given 'b' uncompressed 3139 * bytes. This is based on deflateBounds() in zlib; different 3140 * implementations of zlib compression may conceivably produce more data so 3141 * if your zlib implementation is not zlib itself redefine this macro 3142 * appropriately. 3143 */ 3144 #endif 3145 3146 #define PNG_IMAGE_COMPRESSED_SIZE_MAX(image)\ 3147 PNG_ZLIB_MAX_SIZE((png_alloc_size_t)PNG_IMAGE_DATA_SIZE(image)) 3148 /* An upper bound on the size of the data in the PNG IDAT chunks. */ 3149 3150 #define PNG_IMAGE_PNG_SIZE_MAX_(image, image_size)\ 3151 ((8U/*sig*/+25U/*IHDR*/+16U/*gAMA*/+44U/*cHRM*/+12U/*IEND*/+\ 3152 (((image).format&PNG_FORMAT_FLAG_COLORMAP)?/*colormap: PLTE, tRNS*/\ 3153 12U+3U*(image).colormap_entries/*PLTE data*/+\ 3154 (((image).format&PNG_FORMAT_FLAG_ALPHA)?\ 3155 12U/*tRNS*/+(image).colormap_entries:0U):0U)+\ 3156 12U)+(12U*((image_size)/PNG_ZBUF_SIZE))/*IDAT*/+(image_size)) 3157 /* A helper for the following macro; if your compiler cannot handle the 3158 * following macro use this one with the result of 3159 * PNG_IMAGE_COMPRESSED_SIZE_MAX(image) as the second argument (most 3160 * compilers should handle this just fine.) 3161 */ 3162 3163 #define PNG_IMAGE_PNG_SIZE_MAX(image)\ 3164 PNG_IMAGE_PNG_SIZE_MAX_(image, PNG_IMAGE_COMPRESSED_SIZE_MAX(image)) 3165 /* An upper bound on the total length of the PNG data stream for 'image'. 3166 * The result is of type png_alloc_size_t, on 32-bit systems this may 3167 * overflow even though PNG_IMAGE_DATA_SIZE does not overflow; the write will 3168 * run out of buffer space but return a corrected size which should work. 3169 */ 3170 #endif /* SIMPLIFIED_WRITE */ 3171 /******************************************************************************* 3172 * END OF SIMPLIFIED API 3173 ******************************************************************************/ 3174 #endif /* SIMPLIFIED_{READ|WRITE} */ 3175 3176 /******************************************************************************* 3177 * Section 6: IMPLEMENTATION OPTIONS 3178 ******************************************************************************* 3179 * 3180 * Support for arbitrary implementation-specific optimizations. The API allows 3181 * particular options to be turned on or off. 'Option' is the number of the 3182 * option and 'onoff' is 0 (off) or non-0 (on). The value returned is given 3183 * by the PNG_OPTION_ defines below. 3184 * 3185 * HARDWARE: normally hardware capabilities, such as the Intel SSE instructions, 3186 * are detected at run time, however sometimes it may be impossible 3187 * to do this in user mode, in which case it is necessary to discover 3188 * the capabilities in an OS specific way. Such capabilities are 3189 * listed here when libpng has support for them and must be turned 3190 * ON by the application if present. 3191 * 3192 * SOFTWARE: sometimes software optimizations actually result in performance 3193 * decrease on some architectures or systems, or with some sets of 3194 * PNG images. 'Software' options allow such optimizations to be 3195 * selected at run time. 3196 */ 3197 #ifdef PNG_SET_OPTION_SUPPORTED 3198 #ifdef PNG_ARM_NEON_API_SUPPORTED 3199 # define PNG_ARM_NEON 0 /* HARDWARE: ARM Neon SIMD instructions supported */ 3200 #endif 3201 #define PNG_MAXIMUM_INFLATE_WINDOW 2 /* SOFTWARE: force maximum window */ 3202 #define PNG_SKIP_sRGB_CHECK_PROFILE 4 /* SOFTWARE: Check ICC profile for sRGB */ 3203 #ifdef PNG_MIPS_MSA_API_SUPPORTED 3204 # define PNG_MIPS_MSA 6 /* HARDWARE: MIPS Msa SIMD instructions supported */ 3205 #endif 3206 #ifdef PNG_DISABLE_ADLER32_CHECK_SUPPORTED 3207 # define PNG_IGNORE_ADLER32 8 /* SOFTWARE: disable Adler32 check on IDAT */ 3208 #endif 3209 #ifdef PNG_POWERPC_VSX_API_SUPPORTED 3210 # define PNG_POWERPC_VSX 10 /* HARDWARE: PowerPC VSX SIMD instructions 3211 * supported */ 3212 #endif 3213 #ifdef PNG_MIPS_MMI_API_SUPPORTED 3214 # define PNG_MIPS_MMI 12 /* HARDWARE: MIPS MMI SIMD instructions supported */ 3215 #endif 3216 3217 #define PNG_OPTION_NEXT 14 /* Next option - numbers must be even */ 3218 3219 /* Return values: NOTE: there are four values and 'off' is *not* zero */ 3220 #define PNG_OPTION_UNSET 0 /* Unset - defaults to off */ 3221 #define PNG_OPTION_INVALID 1 /* Option number out of range */ 3222 #define PNG_OPTION_OFF 2 3223 #define PNG_OPTION_ON 3 3224 3225 PNG_EXPORT(244, int, png_set_option, (png_structrp png_ptr, int option, 3226 int onoff)); 3227 #endif /* SET_OPTION */ 3228 3229 /******************************************************************************* 3230 * END OF HARDWARE AND SOFTWARE OPTIONS 3231 ******************************************************************************/ 3232 3233 /* Maintainer: Put new public prototypes here ^, in libpng.3, in project 3234 * defs, and in scripts/symbols.def. 3235 */ 3236 3237 /* The last ordinal number (this is the *last* one already used; the next 3238 * one to use is one more than this.) 3239 */ 3240 #ifdef PNG_EXPORT_LAST_ORDINAL 3241 PNG_EXPORT_LAST_ORDINAL(249); 3242 #endif 3243 3244 #ifdef __cplusplus 3245 } 3246 #endif 3247 3248 #endif /* PNG_VERSION_INFO_ONLY */ 3249 /* Do not put anything past this line */ 3250 #endif /* PNG_H */ 3251