1 2 /* png.h - header file for PNG reference library 3 * 4 * libpng version 1.6.37 - April 14, 2019 5 * 6 * Copyright (c) 2018-2019 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 1.6.37, April 2019: 19 * Cosmin Truta 20 * See also "Contributing Authors", below. 21 */ 22 23 /* 24 * COPYRIGHT NOTICE, DISCLAIMER, and LICENSE 25 * ========================================= 26 * 27 * This modified version of libpng code adds animated PNG support and is 28 * released under the libpng license described below. The modifications are 29 * Copyright (c) 2006-2007 Andrew Smith, Copyright (c) 2008-2019 Max Stepin, 30 * and are delimited by "#ifdef PNG_APNG_SUPPORTED / #endif" directives 31 * surrounding them in the modified libpng source files. 32 * 33 * PNG Reference Library License version 2 34 * --------------------------------------- 35 * 36 * * Copyright (c) 1995-2019 The PNG Reference Library Authors. 37 * * Copyright (c) 2018-2019 Cosmin Truta. 38 * * Copyright (c) 2000-2002, 2004, 2006-2018 Glenn Randers-Pehrson. 39 * * Copyright (c) 1996-1997 Andreas Dilger. 40 * * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc. 41 * 42 * The software is supplied "as is", without warranty of any kind, 43 * express or implied, including, without limitation, the warranties 44 * of merchantability, fitness for a particular purpose, title, and 45 * non-infringement. In no event shall the Copyright owners, or 46 * anyone distributing the software, be liable for any damages or 47 * other liability, whether in contract, tort or otherwise, arising 48 * from, out of, or in connection with the software, or the use or 49 * other dealings in the software, even if advised of the possibility 50 * of such damage. 51 * 52 * Permission is hereby granted to use, copy, modify, and distribute 53 * this software, or portions hereof, for any purpose, without fee, 54 * subject to the following restrictions: 55 * 56 * 1. The origin of this software must not be misrepresented; you 57 * must not claim that you wrote the original software. If you 58 * use this software in a product, an acknowledgment in the product 59 * documentation would be appreciated, but is not required. 60 * 61 * 2. Altered source versions must be plainly marked as such, and must 62 * not be misrepresented as being the original software. 63 * 64 * 3. This Copyright notice may not be removed or altered from any 65 * source or altered source distribution. 66 * 67 * 68 * PNG Reference Library License version 1 (for libpng 0.5 through 1.6.35) 69 * ----------------------------------------------------------------------- 70 * 71 * libpng versions 1.0.7, July 1, 2000, through 1.6.35, July 15, 2018 are 72 * Copyright (c) 2000-2002, 2004, 2006-2018 Glenn Randers-Pehrson, are 73 * derived from libpng-1.0.6, and are distributed according to the same 74 * disclaimer and license as libpng-1.0.6 with the following individuals 75 * added to the list of Contributing Authors: 76 * 77 * Simon-Pierre Cadieux 78 * Eric S. Raymond 79 * Mans Rullgard 80 * Cosmin Truta 81 * Gilles Vollant 82 * James Yu 83 * Mandar Sahastrabuddhe 84 * Google Inc. 85 * Vadim Barkov 86 * 87 * and with the following additions to the disclaimer: 88 * 89 * There is no warranty against interference with your enjoyment of 90 * the library or against infringement. There is no warranty that our 91 * efforts or the library will fulfill any of your particular purposes 92 * or needs. This library is provided with all faults, and the entire 93 * risk of satisfactory quality, performance, accuracy, and effort is 94 * with the user. 95 * 96 * Some files in the "contrib" directory and some configure-generated 97 * files that are distributed with libpng have other copyright owners, and 98 * are released under other open source licenses. 99 * 100 * libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are 101 * Copyright (c) 1998-2000 Glenn Randers-Pehrson, are derived from 102 * libpng-0.96, and are distributed according to the same disclaimer and 103 * license as libpng-0.96, with the following individuals added to the 104 * list of Contributing Authors: 105 * 106 * Tom Lane 107 * Glenn Randers-Pehrson 108 * Willem van Schaik 109 * 110 * libpng versions 0.89, June 1996, through 0.96, May 1997, are 111 * Copyright (c) 1996-1997 Andreas Dilger, are derived from libpng-0.88, 112 * and are distributed according to the same disclaimer and license as 113 * libpng-0.88, with the following individuals added to the list of 114 * Contributing Authors: 115 * 116 * John Bowler 117 * Kevin Bracey 118 * Sam Bushell 119 * Magnus Holmgren 120 * Greg Roelofs 121 * Tom Tanner 122 * 123 * Some files in the "scripts" directory have other copyright owners, 124 * but are released under this license. 125 * 126 * libpng versions 0.5, May 1995, through 0.88, January 1996, are 127 * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc. 128 * 129 * For the purposes of this copyright and license, "Contributing Authors" 130 * is defined as the following set of individuals: 131 * 132 * Andreas Dilger 133 * Dave Martindale 134 * Guy Eric Schalnat 135 * Paul Schmidt 136 * Tim Wegner 137 * 138 * The PNG Reference Library is supplied "AS IS". The Contributing 139 * Authors and Group 42, Inc. disclaim all warranties, expressed or 140 * implied, including, without limitation, the warranties of 141 * merchantability and of fitness for any purpose. The Contributing 142 * Authors and Group 42, Inc. assume no liability for direct, indirect, 143 * incidental, special, exemplary, or consequential damages, which may 144 * result from the use of the PNG Reference Library, even if advised of 145 * the possibility of such damage. 146 * 147 * Permission is hereby granted to use, copy, modify, and distribute this 148 * source code, or portions hereof, for any purpose, without fee, subject 149 * to the following restrictions: 150 * 151 * 1. The origin of this source code must not be misrepresented. 152 * 153 * 2. Altered versions must be plainly marked as such and must not 154 * be misrepresented as being the original source. 155 * 156 * 3. This Copyright notice may not be removed or altered from any 157 * source or altered source distribution. 158 * 159 * The Contributing Authors and Group 42, Inc. specifically permit, 160 * without fee, and encourage the use of this source code as a component 161 * to supporting the PNG file format in commercial products. If you use 162 * this source code in a product, acknowledgment is not required but would 163 * be appreciated. 164 * 165 * END OF COPYRIGHT NOTICE, DISCLAIMER, and LICENSE. 166 * 167 * TRADEMARK 168 * ========= 169 * 170 * The name "libpng" has not been registered by the Copyright owners 171 * as a trademark in any jurisdiction. However, because libpng has 172 * been distributed and maintained world-wide, continually since 1995, 173 * the Copyright owners claim "common-law trademark protection" in any 174 * jurisdiction where common-law trademark is recognized. 175 */ 176 177 /* 178 * A "png_get_copyright" function is available, for convenient use in "about" 179 * boxes and the like: 180 * 181 * printf("%s", png_get_copyright(NULL)); 182 * 183 * Also, the PNG logo (in PNG format, of course) is supplied in the 184 * files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31). 185 */ 186 187 /* 188 * The contributing authors would like to thank all those who helped 189 * with testing, bug fixes, and patience. This wouldn't have been 190 * possible without all of you. 191 * 192 * Thanks to Frank J. T. Wojcik for helping with the documentation. 193 */ 194 195 /* Note about libpng version numbers: 196 * 197 * Due to various miscommunications, unforeseen code incompatibilities 198 * and occasional factors outside the authors' control, version numbering 199 * on the library has not always been consistent and straightforward. 200 * The following table summarizes matters since version 0.89c, which was 201 * the first widely used release: 202 * 203 * source png.h png.h shared-lib 204 * version string int version 205 * ------- ------ ----- ---------- 206 * 0.89c "1.0 beta 3" 0.89 89 1.0.89 207 * 0.90 "1.0 beta 4" 0.90 90 0.90 [should have been 2.0.90] 208 * 0.95 "1.0 beta 5" 0.95 95 0.95 [should have been 2.0.95] 209 * 0.96 "1.0 beta 6" 0.96 96 0.96 [should have been 2.0.96] 210 * 0.97b "1.00.97 beta 7" 1.00.97 97 1.0.1 [should have been 2.0.97] 211 * 0.97c 0.97 97 2.0.97 212 * 0.98 0.98 98 2.0.98 213 * 0.99 0.99 98 2.0.99 214 * 0.99a-m 0.99 99 2.0.99 215 * 1.00 1.00 100 2.1.0 [100 should be 10000] 216 * 1.0.0 (from here on, the 100 2.1.0 [100 should be 10000] 217 * 1.0.1 png.h string is 10001 2.1.0 218 * 1.0.1a-e identical to the 10002 from here on, the shared library 219 * 1.0.2 source version) 10002 is 2.V where V is the source code 220 * 1.0.2a-b 10003 version, except as noted. 221 * 1.0.3 10003 222 * 1.0.3a-d 10004 223 * 1.0.4 10004 224 * 1.0.4a-f 10005 225 * 1.0.5 (+ 2 patches) 10005 226 * 1.0.5a-d 10006 227 * 1.0.5e-r 10100 (not source compatible) 228 * 1.0.5s-v 10006 (not binary compatible) 229 * 1.0.6 (+ 3 patches) 10006 (still binary incompatible) 230 * 1.0.6d-f 10007 (still binary incompatible) 231 * 1.0.6g 10007 232 * 1.0.6h 10007 10.6h (testing xy.z so-numbering) 233 * 1.0.6i 10007 10.6i 234 * 1.0.6j 10007 2.1.0.6j (incompatible with 1.0.0) 235 * 1.0.7beta11-14 DLLNUM 10007 2.1.0.7beta11-14 (binary compatible) 236 * 1.0.7beta15-18 1 10007 2.1.0.7beta15-18 (binary compatible) 237 * 1.0.7rc1-2 1 10007 2.1.0.7rc1-2 (binary compatible) 238 * 1.0.7 1 10007 (still compatible) 239 * ... 240 * 1.0.69 10 10069 10.so.0.69[.0] 241 * ... 242 * 1.2.59 13 10259 12.so.0.59[.0] 243 * ... 244 * 1.4.20 14 10420 14.so.0.20[.0] 245 * ... 246 * 1.5.30 15 10530 15.so.15.30[.0] 247 * ... 248 * 1.6.37 16 10637 16.so.16.37[.0] 249 * 250 * Henceforth the source version will match the shared-library major and 251 * minor numbers; the shared-library major version number will be used for 252 * changes in backward compatibility, as it is intended. 253 * The PNG_LIBPNG_VER macro, which is not used within libpng but is 254 * available for applications, is an unsigned integer of the form XYYZZ 255 * corresponding to the source version X.Y.Z (leading zeros in Y and Z). 256 * Beta versions were given the previous public release number plus a 257 * letter, until version 1.0.6j; from then on they were given the upcoming 258 * public release number plus "betaNN" or "rcNN". 259 * 260 * Binary incompatibility exists only when applications make direct access 261 * to the info_ptr or png_ptr members through png.h, and the compiled 262 * application is loaded with a different version of the library. 263 * 264 * DLLNUM will change each time there are forward or backward changes 265 * in binary compatibility (e.g., when a new feature is added). 266 * 267 * See libpng.txt or libpng.3 for more information. The PNG specification 268 * is available as a W3C Recommendation and as an ISO/IEC Standard; see 269 * <https://www.w3.org/TR/2003/REC-PNG-20031110/> 270 */ 271 272 #ifndef PNG_H 273 #define PNG_H 274 275 /* This is not the place to learn how to use libpng. The file libpng-manual.txt 276 * describes how to use libpng, and the file example.c summarizes it 277 * with some code on which to build. This file is useful for looking 278 * at the actual function definitions and structure components. If that 279 * file has been stripped from your copy of libpng, you can find it at 280 * <http://www.libpng.org/pub/png/libpng-manual.txt> 281 * 282 * If you just need to read a PNG file and don't want to read the documentation 283 * skip to the end of this file and read the section entitled 'simplified API'. 284 */ 285 286 /* Version information for png.h - this should match the version in png.c */ 287 #define PNG_LIBPNG_VER_STRING "1.6.37+apng" 288 #define PNG_HEADER_VERSION_STRING \ 289 " libpng version 1.6.37+apng - April 14, 2019\n" 290 291 #define PNG_LIBPNG_VER_SONUM 16 292 #define PNG_LIBPNG_VER_DLLNUM 16 293 294 /* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */ 295 #define PNG_LIBPNG_VER_MAJOR 1 296 #define PNG_LIBPNG_VER_MINOR 6 297 #define PNG_LIBPNG_VER_RELEASE 37 298 299 /* This should be zero for a public release, or non-zero for a 300 * development version. [Deprecated] 301 */ 302 #define PNG_LIBPNG_VER_BUILD 0 303 304 /* Release Status */ 305 #define PNG_LIBPNG_BUILD_ALPHA 1 306 #define PNG_LIBPNG_BUILD_BETA 2 307 #define PNG_LIBPNG_BUILD_RC 3 308 #define PNG_LIBPNG_BUILD_STABLE 4 309 #define PNG_LIBPNG_BUILD_RELEASE_STATUS_MASK 7 310 311 /* Release-Specific Flags */ 312 #define PNG_LIBPNG_BUILD_PATCH 8 /* Can be OR'ed with 313 PNG_LIBPNG_BUILD_STABLE only */ 314 #define PNG_LIBPNG_BUILD_PRIVATE 16 /* Cannot be OR'ed with 315 PNG_LIBPNG_BUILD_SPECIAL */ 316 #define PNG_LIBPNG_BUILD_SPECIAL 32 /* Cannot be OR'ed with 317 PNG_LIBPNG_BUILD_PRIVATE */ 318 319 #define PNG_LIBPNG_BUILD_BASE_TYPE PNG_LIBPNG_BUILD_STABLE 320 321 /* Careful here. At one time, Guy wanted to use 082, but that 322 * would be octal. We must not include leading zeros. 323 * Versions 0.7 through 1.0.0 were in the range 0 to 100 here 324 * (only version 1.0.0 was mis-numbered 100 instead of 10000). 325 * From version 1.0.1 it is: 326 * XXYYZZ, where XX=major, YY=minor, ZZ=release 327 */ 328 #define PNG_LIBPNG_VER 10637 /* 1.6.37 */ 329 330 /* Library configuration: these options cannot be changed after 331 * the library has been built. 332 */ 333 #ifndef PNGLCONF_H 334 /* If pnglibconf.h is missing, you can 335 * copy scripts/pnglibconf.h.prebuilt to pnglibconf.h 336 */ 337 # include "pnglibconf.h" 338 #endif 339 340 #define PNG_APNG_SUPPORTED 341 #define PNG_READ_APNG_SUPPORTED 342 #define PNG_WRITE_APNG_SUPPORTED 343 344 #ifndef PNG_VERSION_INFO_ONLY 345 /* Machine specific configuration. */ 346 # include "pngconf.h" 347 #endif 348 349 /* 350 * Added at libpng-1.2.8 351 * 352 * Ref MSDN: Private as priority over Special 353 * VS_FF_PRIVATEBUILD File *was not* built using standard release 354 * procedures. If this value is given, the StringFileInfo block must 355 * contain a PrivateBuild string. 356 * 357 * VS_FF_SPECIALBUILD File *was* built by the original company using 358 * standard release procedures but is a variation of the standard 359 * file of the same version number. If this value is given, the 360 * StringFileInfo block must contain a SpecialBuild string. 361 */ 362 363 #ifdef PNG_USER_PRIVATEBUILD /* From pnglibconf.h */ 364 # define PNG_LIBPNG_BUILD_TYPE \ 365 (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_PRIVATE) 366 #else 367 # ifdef PNG_LIBPNG_SPECIALBUILD 368 # define PNG_LIBPNG_BUILD_TYPE \ 369 (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_SPECIAL) 370 # else 371 # define PNG_LIBPNG_BUILD_TYPE (PNG_LIBPNG_BUILD_BASE_TYPE) 372 # endif 373 #endif 374 375 #ifndef PNG_VERSION_INFO_ONLY 376 377 /* Inhibit C++ name-mangling for libpng functions but not for system calls. */ 378 #ifdef __cplusplus 379 extern "C" { 380 #endif /* __cplusplus */ 381 382 /* Version information for C files, stored in png.c. This had better match 383 * the version above. 384 */ 385 #define png_libpng_ver png_get_header_ver(NULL) 386 387 /* This file is arranged in several sections: 388 * 389 * 1. [omitted] 390 * 2. Any configuration options that can be specified by for the application 391 * code when it is built. (Build time configuration is in pnglibconf.h) 392 * 3. Type definitions (base types are defined in pngconf.h), structure 393 * definitions. 394 * 4. Exported library functions. 395 * 5. Simplified API. 396 * 6. Implementation options. 397 * 398 * The library source code has additional files (principally pngpriv.h) that 399 * allow configuration of the library. 400 */ 401 402 /* Section 1: [omitted] */ 403 404 /* Section 2: run time configuration 405 * See pnglibconf.h for build time configuration 406 * 407 * Run time configuration allows the application to choose between 408 * implementations of certain arithmetic APIs. The default is set 409 * at build time and recorded in pnglibconf.h, but it is safe to 410 * override these (and only these) settings. Note that this won't 411 * change what the library does, only application code, and the 412 * settings can (and probably should) be made on a per-file basis 413 * by setting the #defines before including png.h 414 * 415 * Use macros to read integers from PNG data or use the exported 416 * functions? 417 * PNG_USE_READ_MACROS: use the macros (see below) Note that 418 * the macros evaluate their argument multiple times. 419 * PNG_NO_USE_READ_MACROS: call the relevant library function. 420 * 421 * Use the alternative algorithm for compositing alpha samples that 422 * does not use division? 423 * PNG_READ_COMPOSITE_NODIV_SUPPORTED: use the 'no division' 424 * algorithm. 425 * PNG_NO_READ_COMPOSITE_NODIV: use the 'division' algorithm. 426 * 427 * How to handle benign errors if PNG_ALLOW_BENIGN_ERRORS is 428 * false? 429 * PNG_ALLOW_BENIGN_ERRORS: map calls to the benign error 430 * APIs to png_warning. 431 * Otherwise the calls are mapped to png_error. 432 */ 433 434 /* Section 3: type definitions, including structures and compile time 435 * constants. 436 * See pngconf.h for base types that vary by machine/system 437 */ 438 439 #ifdef PNG_APNG_SUPPORTED 440 /* dispose_op flags from inside fcTL */ 441 #define PNG_DISPOSE_OP_NONE 0x00 442 #define PNG_DISPOSE_OP_BACKGROUND 0x01 443 #define PNG_DISPOSE_OP_PREVIOUS 0x02 444 445 /* blend_op flags from inside fcTL */ 446 #define PNG_BLEND_OP_SOURCE 0x00 447 #define PNG_BLEND_OP_OVER 0x01 448 #endif /* APNG */ 449 450 /* This triggers a compiler error in png.c, if png.c and png.h 451 * do not agree upon the version number. 452 */ 453 typedef char* png_libpng_version_1_6_37; 454 455 /* Basic control structions. Read libpng-manual.txt or libpng.3 for more info. 456 * 457 * png_struct is the cache of information used while reading or writing a single 458 * PNG file. One of these is always required, although the simplified API 459 * (below) hides the creation and destruction of it. 460 */ 461 typedef struct png_struct_def png_struct; 462 typedef const png_struct * png_const_structp; 463 typedef png_struct * png_structp; 464 typedef png_struct * * png_structpp; 465 466 /* png_info contains information read from or to be written to a PNG file. One 467 * or more of these must exist while reading or creating a PNG file. The 468 * information is not used by libpng during read but is used to control what 469 * gets written when a PNG file is created. "png_get_" function calls read 470 * information during read and "png_set_" functions calls write information 471 * when creating a PNG. 472 * been moved into a separate header file that is not accessible to 473 * applications. Read libpng-manual.txt or libpng.3 for more info. 474 */ 475 typedef struct png_info_def png_info; 476 typedef png_info * png_infop; 477 typedef const png_info * png_const_infop; 478 typedef png_info * * png_infopp; 479 480 /* Types with names ending 'p' are pointer types. The corresponding types with 481 * names ending 'rp' are identical pointer types except that the pointer is 482 * marked 'restrict', which means that it is the only pointer to the object 483 * passed to the function. Applications should not use the 'restrict' types; 484 * it is always valid to pass 'p' to a pointer with a function argument of the 485 * corresponding 'rp' type. Different compilers have different rules with 486 * regard to type matching in the presence of 'restrict'. For backward 487 * compatibility libpng callbacks never have 'restrict' in their parameters and, 488 * consequentially, writing portable application code is extremely difficult if 489 * an attempt is made to use 'restrict'. 490 */ 491 typedef png_struct * PNG_RESTRICT png_structrp; 492 typedef const png_struct * PNG_RESTRICT png_const_structrp; 493 typedef png_info * PNG_RESTRICT png_inforp; 494 typedef const png_info * PNG_RESTRICT png_const_inforp; 495 496 /* Three color definitions. The order of the red, green, and blue, (and the 497 * exact size) is not important, although the size of the fields need to 498 * be png_byte or png_uint_16 (as defined below). 499 */ 500 typedef struct png_color_struct 501 { 502 png_byte red; 503 png_byte green; 504 png_byte blue; 505 } png_color; 506 typedef png_color * png_colorp; 507 typedef const png_color * png_const_colorp; 508 typedef png_color * * png_colorpp; 509 510 typedef struct png_color_16_struct 511 { 512 png_byte index; /* used for palette files */ 513 png_uint_16 red; /* for use in red green blue files */ 514 png_uint_16 green; 515 png_uint_16 blue; 516 png_uint_16 gray; /* for use in grayscale files */ 517 } png_color_16; 518 typedef png_color_16 * png_color_16p; 519 typedef const png_color_16 * png_const_color_16p; 520 typedef png_color_16 * * png_color_16pp; 521 522 typedef struct png_color_8_struct 523 { 524 png_byte red; /* for use in red green blue files */ 525 png_byte green; 526 png_byte blue; 527 png_byte gray; /* for use in grayscale files */ 528 png_byte alpha; /* for alpha channel files */ 529 } png_color_8; 530 typedef png_color_8 * png_color_8p; 531 typedef const png_color_8 * png_const_color_8p; 532 typedef png_color_8 * * png_color_8pp; 533 534 /* 535 * The following two structures are used for the in-core representation 536 * of sPLT chunks. 537 */ 538 typedef struct png_sPLT_entry_struct 539 { 540 png_uint_16 red; 541 png_uint_16 green; 542 png_uint_16 blue; 543 png_uint_16 alpha; 544 png_uint_16 frequency; 545 } png_sPLT_entry; 546 typedef png_sPLT_entry * png_sPLT_entryp; 547 typedef const png_sPLT_entry * png_const_sPLT_entryp; 548 typedef png_sPLT_entry * * png_sPLT_entrypp; 549 550 /* When the depth of the sPLT palette is 8 bits, the color and alpha samples 551 * occupy the LSB of their respective members, and the MSB of each member 552 * is zero-filled. The frequency member always occupies the full 16 bits. 553 */ 554 555 typedef struct png_sPLT_struct 556 { 557 png_charp name; /* palette name */ 558 png_byte depth; /* depth of palette samples */ 559 png_sPLT_entryp entries; /* palette entries */ 560 png_int_32 nentries; /* number of palette entries */ 561 } png_sPLT_t; 562 typedef png_sPLT_t * png_sPLT_tp; 563 typedef const png_sPLT_t * png_const_sPLT_tp; 564 typedef png_sPLT_t * * png_sPLT_tpp; 565 566 #ifdef PNG_TEXT_SUPPORTED 567 /* png_text holds the contents of a text/ztxt/itxt chunk in a PNG file, 568 * and whether that contents is compressed or not. The "key" field 569 * points to a regular zero-terminated C string. The "text" fields can be a 570 * regular C string, an empty string, or a NULL pointer. 571 * However, the structure returned by png_get_text() will always contain 572 * the "text" field as a regular zero-terminated C string (possibly 573 * empty), never a NULL pointer, so it can be safely used in printf() and 574 * other string-handling functions. Note that the "itxt_length", "lang", and 575 * "lang_key" members of the structure only exist when the library is built 576 * with iTXt chunk support. Prior to libpng-1.4.0 the library was built by 577 * default without iTXt support. Also note that when iTXt *is* supported, 578 * the "lang" and "lang_key" fields contain NULL pointers when the 579 * "compression" field contains * PNG_TEXT_COMPRESSION_NONE or 580 * PNG_TEXT_COMPRESSION_zTXt. Note that the "compression value" is not the 581 * same as what appears in the PNG tEXt/zTXt/iTXt chunk's "compression flag" 582 * which is always 0 or 1, or its "compression method" which is always 0. 583 */ 584 typedef struct png_text_struct 585 { 586 int compression; /* compression value: 587 -1: tEXt, none 588 0: zTXt, deflate 589 1: iTXt, none 590 2: iTXt, deflate */ 591 png_charp key; /* keyword, 1-79 character description of "text" */ 592 png_charp text; /* comment, may be an empty string (ie "") 593 or a NULL pointer */ 594 size_t text_length; /* length of the text string */ 595 size_t itxt_length; /* length of the itxt string */ 596 png_charp lang; /* language code, 0-79 characters 597 or a NULL pointer */ 598 png_charp lang_key; /* keyword translated UTF-8 string, 0 or more 599 chars or a NULL pointer */ 600 } png_text; 601 typedef png_text * png_textp; 602 typedef const png_text * png_const_textp; 603 typedef png_text * * png_textpp; 604 #endif 605 606 /* Supported compression types for text in PNG files (tEXt, and zTXt). 607 * The values of the PNG_TEXT_COMPRESSION_ defines should NOT be changed. */ 608 #define PNG_TEXT_COMPRESSION_NONE_WR -3 609 #define PNG_TEXT_COMPRESSION_zTXt_WR -2 610 #define PNG_TEXT_COMPRESSION_NONE -1 611 #define PNG_TEXT_COMPRESSION_zTXt 0 612 #define PNG_ITXT_COMPRESSION_NONE 1 613 #define PNG_ITXT_COMPRESSION_zTXt 2 614 #define PNG_TEXT_COMPRESSION_LAST 3 /* Not a valid value */ 615 616 /* png_time is a way to hold the time in an machine independent way. 617 * Two conversions are provided, both from time_t and struct tm. There 618 * is no portable way to convert to either of these structures, as far 619 * as I know. If you know of a portable way, send it to me. As a side 620 * note - PNG has always been Year 2000 compliant! 621 */ 622 typedef struct png_time_struct 623 { 624 png_uint_16 year; /* full year, as in, 1995 */ 625 png_byte month; /* month of year, 1 - 12 */ 626 png_byte day; /* day of month, 1 - 31 */ 627 png_byte hour; /* hour of day, 0 - 23 */ 628 png_byte minute; /* minute of hour, 0 - 59 */ 629 png_byte second; /* second of minute, 0 - 60 (for leap seconds) */ 630 } png_time; 631 typedef png_time * png_timep; 632 typedef const png_time * png_const_timep; 633 typedef png_time * * png_timepp; 634 635 #if defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED) ||\ 636 defined(PNG_USER_CHUNKS_SUPPORTED) 637 /* png_unknown_chunk is a structure to hold queued chunks for which there is 638 * no specific support. The idea is that we can use this to queue 639 * up private chunks for output even though the library doesn't actually 640 * know about their semantics. 641 * 642 * The data in the structure is set by libpng on read and used on write. 643 */ 644 typedef struct png_unknown_chunk_t 645 { 646 png_byte name[5]; /* Textual chunk name with '\0' terminator */ 647 png_byte *data; /* Data, should not be modified on read! */ 648 size_t size; 649 650 /* On write 'location' must be set using the flag values listed below. 651 * Notice that on read it is set by libpng however the values stored have 652 * more bits set than are listed below. Always treat the value as a 653 * bitmask. On write set only one bit - setting multiple bits may cause the 654 * chunk to be written in multiple places. 655 */ 656 png_byte location; /* mode of operation at read time */ 657 } 658 png_unknown_chunk; 659 660 typedef png_unknown_chunk * png_unknown_chunkp; 661 typedef const png_unknown_chunk * png_const_unknown_chunkp; 662 typedef png_unknown_chunk * * png_unknown_chunkpp; 663 #endif 664 665 /* Flag values for the unknown chunk location byte. */ 666 #define PNG_HAVE_IHDR 0x01 667 #define PNG_HAVE_PLTE 0x02 668 #define PNG_AFTER_IDAT 0x08 669 670 /* Maximum positive integer used in PNG is (2^31)-1 */ 671 #define PNG_UINT_31_MAX ((png_uint_32)0x7fffffffL) 672 #define PNG_UINT_32_MAX ((png_uint_32)(-1)) 673 #define PNG_SIZE_MAX ((size_t)(-1)) 674 675 /* These are constants for fixed point values encoded in the 676 * PNG specification manner (x100000) 677 */ 678 #define PNG_FP_1 100000 679 #define PNG_FP_HALF 50000 680 #define PNG_FP_MAX ((png_fixed_point)0x7fffffffL) 681 #define PNG_FP_MIN (-PNG_FP_MAX) 682 683 /* These describe the color_type field in png_info. */ 684 /* color type masks */ 685 #define PNG_COLOR_MASK_PALETTE 1 686 #define PNG_COLOR_MASK_COLOR 2 687 #define PNG_COLOR_MASK_ALPHA 4 688 689 /* color types. Note that not all combinations are legal */ 690 #define PNG_COLOR_TYPE_GRAY 0 691 #define PNG_COLOR_TYPE_PALETTE (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE) 692 #define PNG_COLOR_TYPE_RGB (PNG_COLOR_MASK_COLOR) 693 #define PNG_COLOR_TYPE_RGB_ALPHA (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_ALPHA) 694 #define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA) 695 /* aliases */ 696 #define PNG_COLOR_TYPE_RGBA PNG_COLOR_TYPE_RGB_ALPHA 697 #define PNG_COLOR_TYPE_GA PNG_COLOR_TYPE_GRAY_ALPHA 698 699 /* This is for compression type. PNG 1.0-1.2 only define the single type. */ 700 #define PNG_COMPRESSION_TYPE_BASE 0 /* Deflate method 8, 32K window */ 701 #define PNG_COMPRESSION_TYPE_DEFAULT PNG_COMPRESSION_TYPE_BASE 702 703 /* This is for filter type. PNG 1.0-1.2 only define the single type. */ 704 #define PNG_FILTER_TYPE_BASE 0 /* Single row per-byte filtering */ 705 #define PNG_INTRAPIXEL_DIFFERENCING 64 /* Used only in MNG datastreams */ 706 #define PNG_FILTER_TYPE_DEFAULT PNG_FILTER_TYPE_BASE 707 708 /* These are for the interlacing type. These values should NOT be changed. */ 709 #define PNG_INTERLACE_NONE 0 /* Non-interlaced image */ 710 #define PNG_INTERLACE_ADAM7 1 /* Adam7 interlacing */ 711 #define PNG_INTERLACE_LAST 2 /* Not a valid value */ 712 713 /* These are for the oFFs chunk. These values should NOT be changed. */ 714 #define PNG_OFFSET_PIXEL 0 /* Offset in pixels */ 715 #define PNG_OFFSET_MICROMETER 1 /* Offset in micrometers (1/10^6 meter) */ 716 #define PNG_OFFSET_LAST 2 /* Not a valid value */ 717 718 /* These are for the pCAL chunk. These values should NOT be changed. */ 719 #define PNG_EQUATION_LINEAR 0 /* Linear transformation */ 720 #define PNG_EQUATION_BASE_E 1 /* Exponential base e transform */ 721 #define PNG_EQUATION_ARBITRARY 2 /* Arbitrary base exponential transform */ 722 #define PNG_EQUATION_HYPERBOLIC 3 /* Hyperbolic sine transformation */ 723 #define PNG_EQUATION_LAST 4 /* Not a valid value */ 724 725 /* These are for the sCAL chunk. These values should NOT be changed. */ 726 #define PNG_SCALE_UNKNOWN 0 /* unknown unit (image scale) */ 727 #define PNG_SCALE_METER 1 /* meters per pixel */ 728 #define PNG_SCALE_RADIAN 2 /* radians per pixel */ 729 #define PNG_SCALE_LAST 3 /* Not a valid value */ 730 731 /* These are for the pHYs chunk. These values should NOT be changed. */ 732 #define PNG_RESOLUTION_UNKNOWN 0 /* pixels/unknown unit (aspect ratio) */ 733 #define PNG_RESOLUTION_METER 1 /* pixels/meter */ 734 #define PNG_RESOLUTION_LAST 2 /* Not a valid value */ 735 736 /* These are for the sRGB chunk. These values should NOT be changed. */ 737 #define PNG_sRGB_INTENT_PERCEPTUAL 0 738 #define PNG_sRGB_INTENT_RELATIVE 1 739 #define PNG_sRGB_INTENT_SATURATION 2 740 #define PNG_sRGB_INTENT_ABSOLUTE 3 741 #define PNG_sRGB_INTENT_LAST 4 /* Not a valid value */ 742 743 /* This is for text chunks */ 744 #define PNG_KEYWORD_MAX_LENGTH 79 745 746 /* Maximum number of entries in PLTE/sPLT/tRNS arrays */ 747 #define PNG_MAX_PALETTE_LENGTH 256 748 749 /* These determine if an ancillary chunk's data has been successfully read 750 * from the PNG header, or if the application has filled in the corresponding 751 * data in the info_struct to be written into the output file. The values 752 * of the PNG_INFO_<chunk> defines should NOT be changed. 753 */ 754 #define PNG_INFO_gAMA 0x0001U 755 #define PNG_INFO_sBIT 0x0002U 756 #define PNG_INFO_cHRM 0x0004U 757 #define PNG_INFO_PLTE 0x0008U 758 #define PNG_INFO_tRNS 0x0010U 759 #define PNG_INFO_bKGD 0x0020U 760 #define PNG_INFO_hIST 0x0040U 761 #define PNG_INFO_pHYs 0x0080U 762 #define PNG_INFO_oFFs 0x0100U 763 #define PNG_INFO_tIME 0x0200U 764 #define PNG_INFO_pCAL 0x0400U 765 #define PNG_INFO_sRGB 0x0800U /* GR-P, 0.96a */ 766 #define PNG_INFO_iCCP 0x1000U /* ESR, 1.0.6 */ 767 #define PNG_INFO_sPLT 0x2000U /* ESR, 1.0.6 */ 768 #define PNG_INFO_sCAL 0x4000U /* ESR, 1.0.6 */ 769 #define PNG_INFO_IDAT 0x8000U /* ESR, 1.0.6 */ 770 #define PNG_INFO_eXIf 0x10000U /* GR-P, 1.6.31 */ 771 #ifdef PNG_APNG_SUPPORTED 772 #define PNG_INFO_acTL 0x20000U 773 #define PNG_INFO_fcTL 0x40000U 774 #endif 775 776 /* This is used for the transformation routines, as some of them 777 * change these values for the row. It also should enable using 778 * the routines for other purposes. 779 */ 780 typedef struct png_row_info_struct 781 { 782 png_uint_32 width; /* width of row */ 783 size_t rowbytes; /* number of bytes in row */ 784 png_byte color_type; /* color type of row */ 785 png_byte bit_depth; /* bit depth of row */ 786 png_byte channels; /* number of channels (1, 2, 3, or 4) */ 787 png_byte pixel_depth; /* bits per pixel (depth * channels) */ 788 } png_row_info; 789 790 typedef png_row_info * png_row_infop; 791 typedef png_row_info * * png_row_infopp; 792 793 /* These are the function types for the I/O functions and for the functions 794 * that allow the user to override the default I/O functions with his or her 795 * own. The png_error_ptr type should match that of user-supplied warning 796 * and error functions, while the png_rw_ptr type should match that of the 797 * user read/write data functions. Note that the 'write' function must not 798 * modify the buffer it is passed. The 'read' function, on the other hand, is 799 * expected to return the read data in the buffer. 800 */ 801 typedef PNG_CALLBACK(void, *png_error_ptr, (png_structp, png_const_charp)); 802 typedef PNG_CALLBACK(void, *png_rw_ptr, (png_structp, png_bytep, size_t)); 803 typedef PNG_CALLBACK(void, *png_flush_ptr, (png_structp)); 804 typedef PNG_CALLBACK(void, *png_read_status_ptr, (png_structp, png_uint_32, 805 int)); 806 typedef PNG_CALLBACK(void, *png_write_status_ptr, (png_structp, png_uint_32, 807 int)); 808 809 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED 810 typedef PNG_CALLBACK(void, *png_progressive_info_ptr, (png_structp, png_infop)); 811 typedef PNG_CALLBACK(void, *png_progressive_end_ptr, (png_structp, png_infop)); 812 #ifdef PNG_APNG_SUPPORTED 813 typedef PNG_CALLBACK(void, *png_progressive_frame_ptr, (png_structp, 814 png_uint_32)); 815 #endif 816 817 /* The following callback receives png_uint_32 row_number, int pass for the 818 * png_bytep data of the row. When transforming an interlaced image the 819 * row number is the row number within the sub-image of the interlace pass, so 820 * the value will increase to the height of the sub-image (not the full image) 821 * then reset to 0 for the next pass. 822 * 823 * Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to 824 * find the output pixel (x,y) given an interlaced sub-image pixel 825 * (row,col,pass). (See below for these macros.) 826 */ 827 typedef PNG_CALLBACK(void, *png_progressive_row_ptr, (png_structp, png_bytep, 828 png_uint_32, int)); 829 #endif 830 831 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \ 832 defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) 833 typedef PNG_CALLBACK(void, *png_user_transform_ptr, (png_structp, png_row_infop, 834 png_bytep)); 835 #endif 836 837 #ifdef PNG_USER_CHUNKS_SUPPORTED 838 typedef PNG_CALLBACK(int, *png_user_chunk_ptr, (png_structp, 839 png_unknown_chunkp)); 840 #endif 841 #ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED 842 /* not used anywhere */ 843 /* typedef PNG_CALLBACK(void, *png_unknown_chunk_ptr, (png_structp)); */ 844 #endif 845 846 #ifdef PNG_SETJMP_SUPPORTED 847 /* This must match the function definition in <setjmp.h>, and the application 848 * must include this before png.h to obtain the definition of jmp_buf. The 849 * function is required to be PNG_NORETURN, but this is not checked. If the 850 * function does return the application will crash via an abort() or similar 851 * system level call. 852 * 853 * If you get a warning here while building the library you may need to make 854 * changes to ensure that pnglibconf.h records the calling convention used by 855 * your compiler. This may be very difficult - try using a different compiler 856 * to build the library! 857 */ 858 PNG_FUNCTION(void, (PNGCAPI *png_longjmp_ptr), PNGARG((jmp_buf, int)), typedef); 859 #endif 860 861 /* Transform masks for the high-level interface */ 862 #define PNG_TRANSFORM_IDENTITY 0x0000 /* read and write */ 863 #define PNG_TRANSFORM_STRIP_16 0x0001 /* read only */ 864 #define PNG_TRANSFORM_STRIP_ALPHA 0x0002 /* read only */ 865 #define PNG_TRANSFORM_PACKING 0x0004 /* read and write */ 866 #define PNG_TRANSFORM_PACKSWAP 0x0008 /* read and write */ 867 #define PNG_TRANSFORM_EXPAND 0x0010 /* read only */ 868 #define PNG_TRANSFORM_INVERT_MONO 0x0020 /* read and write */ 869 #define PNG_TRANSFORM_SHIFT 0x0040 /* read and write */ 870 #define PNG_TRANSFORM_BGR 0x0080 /* read and write */ 871 #define PNG_TRANSFORM_SWAP_ALPHA 0x0100 /* read and write */ 872 #define PNG_TRANSFORM_SWAP_ENDIAN 0x0200 /* read and write */ 873 #define PNG_TRANSFORM_INVERT_ALPHA 0x0400 /* read and write */ 874 #define PNG_TRANSFORM_STRIP_FILLER 0x0800 /* write only */ 875 /* Added to libpng-1.2.34 */ 876 #define PNG_TRANSFORM_STRIP_FILLER_BEFORE PNG_TRANSFORM_STRIP_FILLER 877 #define PNG_TRANSFORM_STRIP_FILLER_AFTER 0x1000 /* write only */ 878 /* Added to libpng-1.4.0 */ 879 #define PNG_TRANSFORM_GRAY_TO_RGB 0x2000 /* read only */ 880 /* Added to libpng-1.5.4 */ 881 #define PNG_TRANSFORM_EXPAND_16 0x4000 /* read only */ 882 #if INT_MAX >= 0x8000 /* else this might break */ 883 #define PNG_TRANSFORM_SCALE_16 0x8000 /* read only */ 884 #endif 885 886 /* Flags for MNG supported features */ 887 #define PNG_FLAG_MNG_EMPTY_PLTE 0x01 888 #define PNG_FLAG_MNG_FILTER_64 0x04 889 #define PNG_ALL_MNG_FEATURES 0x05 890 891 /* NOTE: prior to 1.5 these functions had no 'API' style declaration, 892 * this allowed the zlib default functions to be used on Windows 893 * platforms. In 1.5 the zlib default malloc (which just calls malloc and 894 * ignores the first argument) should be completely compatible with the 895 * following. 896 */ 897 typedef PNG_CALLBACK(png_voidp, *png_malloc_ptr, (png_structp, 898 png_alloc_size_t)); 899 typedef PNG_CALLBACK(void, *png_free_ptr, (png_structp, png_voidp)); 900 901 /* Section 4: exported functions 902 * Here are the function definitions most commonly used. This is not 903 * the place to find out how to use libpng. See libpng-manual.txt for the 904 * full explanation, see example.c for the summary. This just provides 905 * a simple one line description of the use of each function. 906 * 907 * The PNG_EXPORT() and PNG_EXPORTA() macros used below are defined in 908 * pngconf.h and in the *.dfn files in the scripts directory. 909 * 910 * PNG_EXPORT(ordinal, type, name, (args)); 911 * 912 * ordinal: ordinal that is used while building 913 * *.def files. The ordinal value is only 914 * relevant when preprocessing png.h with 915 * the *.dfn files for building symbol table 916 * entries, and are removed by pngconf.h. 917 * type: return type of the function 918 * name: function name 919 * args: function arguments, with types 920 * 921 * When we wish to append attributes to a function prototype we use 922 * the PNG_EXPORTA() macro instead. 923 * 924 * PNG_EXPORTA(ordinal, type, name, (args), attributes); 925 * 926 * ordinal, type, name, and args: same as in PNG_EXPORT(). 927 * attributes: function attributes 928 */ 929 930 /* Returns the version number of the library */ 931 PNG_EXPORT(1, png_uint_32, png_access_version_number, (void)); 932 933 /* Tell lib we have already handled the first <num_bytes> magic bytes. 934 * Handling more than 8 bytes from the beginning of the file is an error. 935 */ 936 PNG_EXPORT(2, void, png_set_sig_bytes, (png_structrp png_ptr, int num_bytes)); 937 938 /* Check sig[start] through sig[start + num_to_check - 1] to see if it's a 939 * PNG file. Returns zero if the supplied bytes match the 8-byte PNG 940 * signature, and non-zero otherwise. Having num_to_check == 0 or 941 * start > 7 will always fail (ie return non-zero). 942 */ 943 PNG_EXPORT(3, int, png_sig_cmp, (png_const_bytep sig, size_t start, 944 size_t num_to_check)); 945 946 /* Simple signature checking function. This is the same as calling 947 * png_check_sig(sig, n) := !png_sig_cmp(sig, 0, n). 948 */ 949 #define png_check_sig(sig, n) !png_sig_cmp((sig), 0, (n)) 950 951 /* Allocate and initialize png_ptr struct for reading, and any other memory. */ 952 PNG_EXPORTA(4, png_structp, png_create_read_struct, 953 (png_const_charp user_png_ver, png_voidp error_ptr, 954 png_error_ptr error_fn, png_error_ptr warn_fn), 955 PNG_ALLOCATED); 956 957 /* Allocate and initialize png_ptr struct for writing, and any other memory */ 958 PNG_EXPORTA(5, png_structp, png_create_write_struct, 959 (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn, 960 png_error_ptr warn_fn), 961 PNG_ALLOCATED); 962 963 PNG_EXPORT(6, size_t, png_get_compression_buffer_size, 964 (png_const_structrp png_ptr)); 965 966 PNG_EXPORT(7, void, png_set_compression_buffer_size, (png_structrp png_ptr, 967 size_t size)); 968 969 /* Moved from pngconf.h in 1.4.0 and modified to ensure setjmp/longjmp 970 * match up. 971 */ 972 #ifdef PNG_SETJMP_SUPPORTED 973 /* This function returns the jmp_buf built in to *png_ptr. It must be 974 * supplied with an appropriate 'longjmp' function to use on that jmp_buf 975 * unless the default error function is overridden in which case NULL is 976 * acceptable. The size of the jmp_buf is checked against the actual size 977 * allocated by the library - the call will return NULL on a mismatch 978 * indicating an ABI mismatch. 979 */ 980 PNG_EXPORT(8, jmp_buf*, png_set_longjmp_fn, (png_structrp png_ptr, 981 png_longjmp_ptr longjmp_fn, size_t jmp_buf_size)); 982 # define png_jmpbuf(png_ptr) \ 983 (*png_set_longjmp_fn((png_ptr), longjmp, (sizeof (jmp_buf)))) 984 #else 985 # define png_jmpbuf(png_ptr) \ 986 (LIBPNG_WAS_COMPILED_WITH__PNG_NO_SETJMP) 987 #endif 988 /* This function should be used by libpng applications in place of 989 * longjmp(png_ptr->jmpbuf, val). If longjmp_fn() has been set, it 990 * will use it; otherwise it will call PNG_ABORT(). This function was 991 * added in libpng-1.5.0. 992 */ 993 PNG_EXPORTA(9, void, png_longjmp, (png_const_structrp png_ptr, int val), 994 PNG_NORETURN); 995 996 #ifdef PNG_READ_SUPPORTED 997 /* Reset the compression stream */ 998 PNG_EXPORTA(10, int, png_reset_zstream, (png_structrp png_ptr), PNG_DEPRECATED); 999 #endif 1000 1001 /* New functions added in libpng-1.0.2 (not enabled by default until 1.2.0) */ 1002 #ifdef PNG_USER_MEM_SUPPORTED 1003 PNG_EXPORTA(11, png_structp, png_create_read_struct_2, 1004 (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn, 1005 png_error_ptr warn_fn, 1006 png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn), 1007 PNG_ALLOCATED); 1008 PNG_EXPORTA(12, png_structp, png_create_write_struct_2, 1009 (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn, 1010 png_error_ptr warn_fn, 1011 png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn), 1012 PNG_ALLOCATED); 1013 #endif 1014 1015 /* Write the PNG file signature. */ 1016 PNG_EXPORT(13, void, png_write_sig, (png_structrp png_ptr)); 1017 1018 /* Write a PNG chunk - size, type, (optional) data, CRC. */ 1019 PNG_EXPORT(14, void, png_write_chunk, (png_structrp png_ptr, png_const_bytep 1020 chunk_name, png_const_bytep data, size_t length)); 1021 1022 /* Write the start of a PNG chunk - length and chunk name. */ 1023 PNG_EXPORT(15, void, png_write_chunk_start, (png_structrp png_ptr, 1024 png_const_bytep chunk_name, png_uint_32 length)); 1025 1026 /* Write the data of a PNG chunk started with png_write_chunk_start(). */ 1027 PNG_EXPORT(16, void, png_write_chunk_data, (png_structrp png_ptr, 1028 png_const_bytep data, size_t length)); 1029 1030 /* Finish a chunk started with png_write_chunk_start() (includes CRC). */ 1031 PNG_EXPORT(17, void, png_write_chunk_end, (png_structrp png_ptr)); 1032 1033 /* Allocate and initialize the info structure */ 1034 PNG_EXPORTA(18, png_infop, png_create_info_struct, (png_const_structrp png_ptr), 1035 PNG_ALLOCATED); 1036 1037 /* DEPRECATED: this function allowed init structures to be created using the 1038 * default allocation method (typically malloc). Use is deprecated in 1.6.0 and 1039 * the API will be removed in the future. 1040 */ 1041 PNG_EXPORTA(19, void, png_info_init_3, (png_infopp info_ptr, 1042 size_t png_info_struct_size), PNG_DEPRECATED); 1043 1044 /* Writes all the PNG information before the image. */ 1045 PNG_EXPORT(20, void, png_write_info_before_PLTE, 1046 (png_structrp png_ptr, png_const_inforp info_ptr)); 1047 PNG_EXPORT(21, void, png_write_info, 1048 (png_structrp png_ptr, png_const_inforp info_ptr)); 1049 1050 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED 1051 /* Read the information before the actual image data. */ 1052 PNG_EXPORT(22, void, png_read_info, 1053 (png_structrp png_ptr, png_inforp info_ptr)); 1054 #endif 1055 1056 #ifdef PNG_TIME_RFC1123_SUPPORTED 1057 /* Convert to a US string format: there is no localization support in this 1058 * routine. The original implementation used a 29 character buffer in 1059 * png_struct, this will be removed in future versions. 1060 */ 1061 #if PNG_LIBPNG_VER < 10700 1062 /* To do: remove this from libpng17 (and from libpng17/png.c and pngstruct.h) */ 1063 PNG_EXPORTA(23, png_const_charp, png_convert_to_rfc1123, (png_structrp png_ptr, 1064 png_const_timep ptime),PNG_DEPRECATED); 1065 #endif 1066 PNG_EXPORT(241, int, png_convert_to_rfc1123_buffer, (char out[29], 1067 png_const_timep ptime)); 1068 #endif 1069 1070 #ifdef PNG_CONVERT_tIME_SUPPORTED 1071 /* Convert from a struct tm to png_time */ 1072 PNG_EXPORT(24, void, png_convert_from_struct_tm, (png_timep ptime, 1073 const struct tm * ttime)); 1074 1075 /* Convert from time_t to png_time. Uses gmtime() */ 1076 PNG_EXPORT(25, void, png_convert_from_time_t, (png_timep ptime, time_t ttime)); 1077 #endif /* CONVERT_tIME */ 1078 1079 #ifdef PNG_READ_EXPAND_SUPPORTED 1080 /* Expand data to 24-bit RGB, or 8-bit grayscale, with alpha if available. */ 1081 PNG_EXPORT(26, void, png_set_expand, (png_structrp png_ptr)); 1082 PNG_EXPORT(27, void, png_set_expand_gray_1_2_4_to_8, (png_structrp png_ptr)); 1083 PNG_EXPORT(28, void, png_set_palette_to_rgb, (png_structrp png_ptr)); 1084 PNG_EXPORT(29, void, png_set_tRNS_to_alpha, (png_structrp png_ptr)); 1085 #endif 1086 1087 #ifdef PNG_READ_EXPAND_16_SUPPORTED 1088 /* Expand to 16-bit channels, forces conversion of palette to RGB and expansion 1089 * of a tRNS chunk if present. 1090 */ 1091 PNG_EXPORT(221, void, png_set_expand_16, (png_structrp png_ptr)); 1092 #endif 1093 1094 #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED) 1095 /* Use blue, green, red order for pixels. */ 1096 PNG_EXPORT(30, void, png_set_bgr, (png_structrp png_ptr)); 1097 #endif 1098 1099 #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED 1100 /* Expand the grayscale to 24-bit RGB if necessary. */ 1101 PNG_EXPORT(31, void, png_set_gray_to_rgb, (png_structrp png_ptr)); 1102 #endif 1103 1104 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED 1105 /* Reduce RGB to grayscale. */ 1106 #define PNG_ERROR_ACTION_NONE 1 1107 #define PNG_ERROR_ACTION_WARN 2 1108 #define PNG_ERROR_ACTION_ERROR 3 1109 #define PNG_RGB_TO_GRAY_DEFAULT (-1)/*for red/green coefficients*/ 1110 1111 PNG_FP_EXPORT(32, void, png_set_rgb_to_gray, (png_structrp png_ptr, 1112 int error_action, double red, double green)) 1113 PNG_FIXED_EXPORT(33, void, png_set_rgb_to_gray_fixed, (png_structrp png_ptr, 1114 int error_action, png_fixed_point red, png_fixed_point green)) 1115 1116 PNG_EXPORT(34, png_byte, png_get_rgb_to_gray_status, (png_const_structrp 1117 png_ptr)); 1118 #endif 1119 1120 #ifdef PNG_BUILD_GRAYSCALE_PALETTE_SUPPORTED 1121 PNG_EXPORT(35, void, png_build_grayscale_palette, (int bit_depth, 1122 png_colorp palette)); 1123 #endif 1124 1125 #ifdef PNG_READ_ALPHA_MODE_SUPPORTED 1126 /* How the alpha channel is interpreted - this affects how the color channels 1127 * of a PNG file are returned to the calling application when an alpha channel, 1128 * or a tRNS chunk in a palette file, is present. 1129 * 1130 * This has no effect on the way pixels are written into a PNG output 1131 * datastream. The color samples in a PNG datastream are never premultiplied 1132 * with the alpha samples. 1133 * 1134 * The default is to return data according to the PNG specification: the alpha 1135 * channel is a linear measure of the contribution of the pixel to the 1136 * corresponding composited pixel, and the color channels are unassociated 1137 * (not premultiplied). The gamma encoded color channels must be scaled 1138 * according to the contribution and to do this it is necessary to undo 1139 * the encoding, scale the color values, perform the composition and re-encode 1140 * the values. This is the 'PNG' mode. 1141 * 1142 * The alternative is to 'associate' the alpha with the color information by 1143 * storing color channel values that have been scaled by the alpha. 1144 * image. These are the 'STANDARD', 'ASSOCIATED' or 'PREMULTIPLIED' modes 1145 * (the latter being the two common names for associated alpha color channels). 1146 * 1147 * For the 'OPTIMIZED' mode, a pixel is treated as opaque only if the alpha 1148 * value is equal to the maximum value. 1149 * 1150 * The final choice is to gamma encode the alpha channel as well. This is 1151 * broken because, in practice, no implementation that uses this choice 1152 * correctly undoes the encoding before handling alpha composition. Use this 1153 * choice only if other serious errors in the software or hardware you use 1154 * mandate it; the typical serious error is for dark halos to appear around 1155 * opaque areas of the composited PNG image because of arithmetic overflow. 1156 * 1157 * The API function png_set_alpha_mode specifies which of these choices to use 1158 * with an enumerated 'mode' value and the gamma of the required output: 1159 */ 1160 #define PNG_ALPHA_PNG 0 /* according to the PNG standard */ 1161 #define PNG_ALPHA_STANDARD 1 /* according to Porter/Duff */ 1162 #define PNG_ALPHA_ASSOCIATED 1 /* as above; this is the normal practice */ 1163 #define PNG_ALPHA_PREMULTIPLIED 1 /* as above */ 1164 #define PNG_ALPHA_OPTIMIZED 2 /* 'PNG' for opaque pixels, else 'STANDARD' */ 1165 #define PNG_ALPHA_BROKEN 3 /* the alpha channel is gamma encoded */ 1166 1167 PNG_FP_EXPORT(227, void, png_set_alpha_mode, (png_structrp png_ptr, int mode, 1168 double output_gamma)) 1169 PNG_FIXED_EXPORT(228, void, png_set_alpha_mode_fixed, (png_structrp png_ptr, 1170 int mode, png_fixed_point output_gamma)) 1171 #endif 1172 1173 #if defined(PNG_GAMMA_SUPPORTED) || defined(PNG_READ_ALPHA_MODE_SUPPORTED) 1174 /* The output_gamma value is a screen gamma in libpng terminology: it expresses 1175 * how to decode the output values, not how they are encoded. 1176 */ 1177 #define PNG_DEFAULT_sRGB -1 /* sRGB gamma and color space */ 1178 #define PNG_GAMMA_MAC_18 -2 /* Old Mac '1.8' gamma and color space */ 1179 #define PNG_GAMMA_sRGB 220000 /* Television standards--matches sRGB gamma */ 1180 #define PNG_GAMMA_LINEAR PNG_FP_1 /* Linear */ 1181 #endif 1182 1183 /* The following are examples of calls to png_set_alpha_mode to achieve the 1184 * required overall gamma correction and, where necessary, alpha 1185 * premultiplication. 1186 * 1187 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB); 1188 * This is the default libpng handling of the alpha channel - it is not 1189 * pre-multiplied into the color components. In addition the call states 1190 * that the output is for a sRGB system and causes all PNG files without gAMA 1191 * chunks to be assumed to be encoded using sRGB. 1192 * 1193 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC); 1194 * In this case the output is assumed to be something like an sRGB conformant 1195 * display preceded by a power-law lookup table of power 1.45. This is how 1196 * early Mac systems behaved. 1197 * 1198 * png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_GAMMA_LINEAR); 1199 * This is the classic Jim Blinn approach and will work in academic 1200 * environments where everything is done by the book. It has the shortcoming 1201 * of assuming that input PNG data with no gamma information is linear - this 1202 * is unlikely to be correct unless the PNG files where generated locally. 1203 * Most of the time the output precision will be so low as to show 1204 * significant banding in dark areas of the image. 1205 * 1206 * png_set_expand_16(pp); 1207 * png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_DEFAULT_sRGB); 1208 * This is a somewhat more realistic Jim Blinn inspired approach. PNG files 1209 * are assumed to have the sRGB encoding if not marked with a gamma value and 1210 * the output is always 16 bits per component. This permits accurate scaling 1211 * and processing of the data. If you know that your input PNG files were 1212 * generated locally you might need to replace PNG_DEFAULT_sRGB with the 1213 * correct value for your system. 1214 * 1215 * png_set_alpha_mode(pp, PNG_ALPHA_OPTIMIZED, PNG_DEFAULT_sRGB); 1216 * If you just need to composite the PNG image onto an existing background 1217 * and if you control the code that does this you can use the optimization 1218 * setting. In this case you just copy completely opaque pixels to the 1219 * output. For pixels that are not completely transparent (you just skip 1220 * those) you do the composition math using png_composite or png_composite_16 1221 * below then encode the resultant 8-bit or 16-bit values to match the output 1222 * encoding. 1223 * 1224 * Other cases 1225 * If neither the PNG nor the standard linear encoding work for you because 1226 * of the software or hardware you use then you have a big problem. The PNG 1227 * case will probably result in halos around the image. The linear encoding 1228 * will probably result in a washed out, too bright, image (it's actually too 1229 * contrasty.) Try the ALPHA_OPTIMIZED mode above - this will probably 1230 * substantially reduce the halos. Alternatively try: 1231 * 1232 * png_set_alpha_mode(pp, PNG_ALPHA_BROKEN, PNG_DEFAULT_sRGB); 1233 * This option will also reduce the halos, but there will be slight dark 1234 * halos round the opaque parts of the image where the background is light. 1235 * In the OPTIMIZED mode the halos will be light halos where the background 1236 * is dark. Take your pick - the halos are unavoidable unless you can get 1237 * your hardware/software fixed! (The OPTIMIZED approach is slightly 1238 * faster.) 1239 * 1240 * When the default gamma of PNG files doesn't match the output gamma. 1241 * If you have PNG files with no gamma information png_set_alpha_mode allows 1242 * you to provide a default gamma, but it also sets the output gamma to the 1243 * matching value. If you know your PNG files have a gamma that doesn't 1244 * match the output you can take advantage of the fact that 1245 * png_set_alpha_mode always sets the output gamma but only sets the PNG 1246 * default if it is not already set: 1247 * 1248 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB); 1249 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC); 1250 * The first call sets both the default and the output gamma values, the 1251 * second call overrides the output gamma without changing the default. This 1252 * is easier than achieving the same effect with png_set_gamma. You must use 1253 * PNG_ALPHA_PNG for the first call - internal checking in png_set_alpha will 1254 * fire if more than one call to png_set_alpha_mode and png_set_background is 1255 * made in the same read operation, however multiple calls with PNG_ALPHA_PNG 1256 * are ignored. 1257 */ 1258 1259 #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED 1260 PNG_EXPORT(36, void, png_set_strip_alpha, (png_structrp png_ptr)); 1261 #endif 1262 1263 #if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \ 1264 defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED) 1265 PNG_EXPORT(37, void, png_set_swap_alpha, (png_structrp png_ptr)); 1266 #endif 1267 1268 #if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \ 1269 defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED) 1270 PNG_EXPORT(38, void, png_set_invert_alpha, (png_structrp png_ptr)); 1271 #endif 1272 1273 #if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED) 1274 /* Add a filler byte to 8-bit or 16-bit Gray or 24-bit or 48-bit RGB images. */ 1275 PNG_EXPORT(39, void, png_set_filler, (png_structrp png_ptr, png_uint_32 filler, 1276 int flags)); 1277 /* The values of the PNG_FILLER_ defines should NOT be changed */ 1278 # define PNG_FILLER_BEFORE 0 1279 # define PNG_FILLER_AFTER 1 1280 /* Add an alpha byte to 8-bit or 16-bit Gray or 24-bit or 48-bit RGB images. */ 1281 PNG_EXPORT(40, void, png_set_add_alpha, (png_structrp png_ptr, 1282 png_uint_32 filler, int flags)); 1283 #endif /* READ_FILLER || WRITE_FILLER */ 1284 1285 #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED) 1286 /* Swap bytes in 16-bit depth files. */ 1287 PNG_EXPORT(41, void, png_set_swap, (png_structrp png_ptr)); 1288 #endif 1289 1290 #if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED) 1291 /* Use 1 byte per pixel in 1, 2, or 4-bit depth files. */ 1292 PNG_EXPORT(42, void, png_set_packing, (png_structrp png_ptr)); 1293 #endif 1294 1295 #if defined(PNG_READ_PACKSWAP_SUPPORTED) || \ 1296 defined(PNG_WRITE_PACKSWAP_SUPPORTED) 1297 /* Swap packing order of pixels in bytes. */ 1298 PNG_EXPORT(43, void, png_set_packswap, (png_structrp png_ptr)); 1299 #endif 1300 1301 #if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED) 1302 /* Converts files to legal bit depths. */ 1303 PNG_EXPORT(44, void, png_set_shift, (png_structrp png_ptr, png_const_color_8p 1304 true_bits)); 1305 #endif 1306 1307 #if defined(PNG_READ_INTERLACING_SUPPORTED) || \ 1308 defined(PNG_WRITE_INTERLACING_SUPPORTED) 1309 /* Have the code handle the interlacing. Returns the number of passes. 1310 * MUST be called before png_read_update_info or png_start_read_image, 1311 * otherwise it will not have the desired effect. Note that it is still 1312 * necessary to call png_read_row or png_read_rows png_get_image_height 1313 * times for each pass. 1314 */ 1315 PNG_EXPORT(45, int, png_set_interlace_handling, (png_structrp png_ptr)); 1316 #endif 1317 1318 #if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED) 1319 /* Invert monochrome files */ 1320 PNG_EXPORT(46, void, png_set_invert_mono, (png_structrp png_ptr)); 1321 #endif 1322 1323 #ifdef PNG_READ_BACKGROUND_SUPPORTED 1324 /* Handle alpha and tRNS by replacing with a background color. Prior to 1325 * libpng-1.5.4 this API must not be called before the PNG file header has been 1326 * read. Doing so will result in unexpected behavior and possible warnings or 1327 * errors if the PNG file contains a bKGD chunk. 1328 */ 1329 PNG_FP_EXPORT(47, void, png_set_background, (png_structrp png_ptr, 1330 png_const_color_16p background_color, int background_gamma_code, 1331 int need_expand, double background_gamma)) 1332 PNG_FIXED_EXPORT(215, void, png_set_background_fixed, (png_structrp png_ptr, 1333 png_const_color_16p background_color, int background_gamma_code, 1334 int need_expand, png_fixed_point background_gamma)) 1335 #endif 1336 #ifdef PNG_READ_BACKGROUND_SUPPORTED 1337 # define PNG_BACKGROUND_GAMMA_UNKNOWN 0 1338 # define PNG_BACKGROUND_GAMMA_SCREEN 1 1339 # define PNG_BACKGROUND_GAMMA_FILE 2 1340 # define PNG_BACKGROUND_GAMMA_UNIQUE 3 1341 #endif 1342 1343 #ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED 1344 /* Scale a 16-bit depth file down to 8-bit, accurately. */ 1345 PNG_EXPORT(229, void, png_set_scale_16, (png_structrp png_ptr)); 1346 #endif 1347 1348 #ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED 1349 #define PNG_READ_16_TO_8_SUPPORTED /* Name prior to 1.5.4 */ 1350 /* Strip the second byte of information from a 16-bit depth file. */ 1351 PNG_EXPORT(48, void, png_set_strip_16, (png_structrp png_ptr)); 1352 #endif 1353 1354 #ifdef PNG_READ_QUANTIZE_SUPPORTED 1355 /* Turn on quantizing, and reduce the palette to the number of colors 1356 * available. 1357 */ 1358 PNG_EXPORT(49, void, png_set_quantize, (png_structrp png_ptr, 1359 png_colorp palette, int num_palette, int maximum_colors, 1360 png_const_uint_16p histogram, int full_quantize)); 1361 #endif 1362 1363 #ifdef PNG_READ_GAMMA_SUPPORTED 1364 /* The threshold on gamma processing is configurable but hard-wired into the 1365 * library. The following is the floating point variant. 1366 */ 1367 #define PNG_GAMMA_THRESHOLD (PNG_GAMMA_THRESHOLD_FIXED*.00001) 1368 1369 /* Handle gamma correction. Screen_gamma=(display_exponent). 1370 * NOTE: this API simply sets the screen and file gamma values. It will 1371 * therefore override the value for gamma in a PNG file if it is called after 1372 * the file header has been read - use with care - call before reading the PNG 1373 * file for best results! 1374 * 1375 * These routines accept the same gamma values as png_set_alpha_mode (described 1376 * above). The PNG_GAMMA_ defines and PNG_DEFAULT_sRGB can be passed to either 1377 * API (floating point or fixed.) Notice, however, that the 'file_gamma' value 1378 * is the inverse of a 'screen gamma' value. 1379 */ 1380 PNG_FP_EXPORT(50, void, png_set_gamma, (png_structrp png_ptr, 1381 double screen_gamma, double override_file_gamma)) 1382 PNG_FIXED_EXPORT(208, void, png_set_gamma_fixed, (png_structrp png_ptr, 1383 png_fixed_point screen_gamma, png_fixed_point override_file_gamma)) 1384 #endif 1385 1386 #ifdef PNG_WRITE_FLUSH_SUPPORTED 1387 /* Set how many lines between output flushes - 0 for no flushing */ 1388 PNG_EXPORT(51, void, png_set_flush, (png_structrp png_ptr, int nrows)); 1389 /* Flush the current PNG output buffer */ 1390 PNG_EXPORT(52, void, png_write_flush, (png_structrp png_ptr)); 1391 #endif 1392 1393 /* Optional update palette with requested transformations */ 1394 PNG_EXPORT(53, void, png_start_read_image, (png_structrp png_ptr)); 1395 1396 /* Optional call to update the users info structure */ 1397 PNG_EXPORT(54, void, png_read_update_info, (png_structrp png_ptr, 1398 png_inforp info_ptr)); 1399 1400 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED 1401 /* Read one or more rows of image data. */ 1402 PNG_EXPORT(55, void, png_read_rows, (png_structrp png_ptr, png_bytepp row, 1403 png_bytepp display_row, png_uint_32 num_rows)); 1404 #endif 1405 1406 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED 1407 /* Read a row of data. */ 1408 PNG_EXPORT(56, void, png_read_row, (png_structrp png_ptr, png_bytep row, 1409 png_bytep display_row)); 1410 #endif 1411 1412 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED 1413 /* Read the whole image into memory at once. */ 1414 PNG_EXPORT(57, void, png_read_image, (png_structrp png_ptr, png_bytepp image)); 1415 #endif 1416 1417 /* Write a row of image data */ 1418 PNG_EXPORT(58, void, png_write_row, (png_structrp png_ptr, 1419 png_const_bytep row)); 1420 1421 /* Write a few rows of image data: (*row) is not written; however, the type 1422 * is declared as writeable to maintain compatibility with previous versions 1423 * of libpng and to allow the 'display_row' array from read_rows to be passed 1424 * unchanged to write_rows. 1425 */ 1426 PNG_EXPORT(59, void, png_write_rows, (png_structrp png_ptr, png_bytepp row, 1427 png_uint_32 num_rows)); 1428 1429 /* Write the image data */ 1430 PNG_EXPORT(60, void, png_write_image, (png_structrp png_ptr, png_bytepp image)); 1431 1432 /* Write the end of the PNG file. */ 1433 PNG_EXPORT(61, void, png_write_end, (png_structrp png_ptr, 1434 png_inforp info_ptr)); 1435 1436 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED 1437 /* Read the end of the PNG file. */ 1438 PNG_EXPORT(62, void, png_read_end, (png_structrp png_ptr, png_inforp info_ptr)); 1439 #endif 1440 1441 /* Free any memory associated with the png_info_struct */ 1442 PNG_EXPORT(63, void, png_destroy_info_struct, (png_const_structrp png_ptr, 1443 png_infopp info_ptr_ptr)); 1444 1445 /* Free any memory associated with the png_struct and the png_info_structs */ 1446 PNG_EXPORT(64, void, png_destroy_read_struct, (png_structpp png_ptr_ptr, 1447 png_infopp info_ptr_ptr, png_infopp end_info_ptr_ptr)); 1448 1449 /* Free any memory associated with the png_struct and the png_info_structs */ 1450 PNG_EXPORT(65, void, png_destroy_write_struct, (png_structpp png_ptr_ptr, 1451 png_infopp info_ptr_ptr)); 1452 1453 /* Set the libpng method of handling chunk CRC errors */ 1454 PNG_EXPORT(66, void, png_set_crc_action, (png_structrp png_ptr, int crit_action, 1455 int ancil_action)); 1456 1457 /* Values for png_set_crc_action() say how to handle CRC errors in 1458 * ancillary and critical chunks, and whether to use the data contained 1459 * therein. Note that it is impossible to "discard" data in a critical 1460 * chunk. For versions prior to 0.90, the action was always error/quit, 1461 * whereas in version 0.90 and later, the action for CRC errors in ancillary 1462 * chunks is warn/discard. These values should NOT be changed. 1463 * 1464 * value action:critical action:ancillary 1465 */ 1466 #define PNG_CRC_DEFAULT 0 /* error/quit warn/discard data */ 1467 #define PNG_CRC_ERROR_QUIT 1 /* error/quit error/quit */ 1468 #define PNG_CRC_WARN_DISCARD 2 /* (INVALID) warn/discard data */ 1469 #define PNG_CRC_WARN_USE 3 /* warn/use data warn/use data */ 1470 #define PNG_CRC_QUIET_USE 4 /* quiet/use data quiet/use data */ 1471 #define PNG_CRC_NO_CHANGE 5 /* use current value use current value */ 1472 1473 #ifdef PNG_WRITE_SUPPORTED 1474 /* These functions give the user control over the scan-line filtering in 1475 * libpng and the compression methods used by zlib. These functions are 1476 * mainly useful for testing, as the defaults should work with most users. 1477 * Those users who are tight on memory or want faster performance at the 1478 * expense of compression can modify them. See the compression library 1479 * header file (zlib.h) for an explination of the compression functions. 1480 */ 1481 1482 /* Set the filtering method(s) used by libpng. Currently, the only valid 1483 * value for "method" is 0. 1484 */ 1485 PNG_EXPORT(67, void, png_set_filter, (png_structrp png_ptr, int method, 1486 int filters)); 1487 #endif /* WRITE */ 1488 1489 /* Flags for png_set_filter() to say which filters to use. The flags 1490 * are chosen so that they don't conflict with real filter types 1491 * below, in case they are supplied instead of the #defined constants. 1492 * These values should NOT be changed. 1493 */ 1494 #define PNG_NO_FILTERS 0x00 1495 #define PNG_FILTER_NONE 0x08 1496 #define PNG_FILTER_SUB 0x10 1497 #define PNG_FILTER_UP 0x20 1498 #define PNG_FILTER_AVG 0x40 1499 #define PNG_FILTER_PAETH 0x80 1500 #define PNG_FAST_FILTERS (PNG_FILTER_NONE | PNG_FILTER_SUB | PNG_FILTER_UP) 1501 #define PNG_ALL_FILTERS (PNG_FAST_FILTERS | PNG_FILTER_AVG | PNG_FILTER_PAETH) 1502 1503 /* Filter values (not flags) - used in pngwrite.c, pngwutil.c for now. 1504 * These defines should NOT be changed. 1505 */ 1506 #define PNG_FILTER_VALUE_NONE 0 1507 #define PNG_FILTER_VALUE_SUB 1 1508 #define PNG_FILTER_VALUE_UP 2 1509 #define PNG_FILTER_VALUE_AVG 3 1510 #define PNG_FILTER_VALUE_PAETH 4 1511 #define PNG_FILTER_VALUE_LAST 5 1512 1513 #ifdef PNG_WRITE_SUPPORTED 1514 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* DEPRECATED */ 1515 PNG_FP_EXPORT(68, void, png_set_filter_heuristics, (png_structrp png_ptr, 1516 int heuristic_method, int num_weights, png_const_doublep filter_weights, 1517 png_const_doublep filter_costs)) 1518 PNG_FIXED_EXPORT(209, void, png_set_filter_heuristics_fixed, 1519 (png_structrp png_ptr, int heuristic_method, int num_weights, 1520 png_const_fixed_point_p filter_weights, 1521 png_const_fixed_point_p filter_costs)) 1522 #endif /* WRITE_WEIGHTED_FILTER */ 1523 1524 /* The following are no longer used and will be removed from libpng-1.7: */ 1525 #define PNG_FILTER_HEURISTIC_DEFAULT 0 /* Currently "UNWEIGHTED" */ 1526 #define PNG_FILTER_HEURISTIC_UNWEIGHTED 1 /* Used by libpng < 0.95 */ 1527 #define PNG_FILTER_HEURISTIC_WEIGHTED 2 /* Experimental feature */ 1528 #define PNG_FILTER_HEURISTIC_LAST 3 /* Not a valid value */ 1529 1530 /* Set the library compression level. Currently, valid values range from 1531 * 0 - 9, corresponding directly to the zlib compression levels 0 - 9 1532 * (0 - no compression, 9 - "maximal" compression). Note that tests have 1533 * shown that zlib compression levels 3-6 usually perform as well as level 9 1534 * for PNG images, and do considerably fewer caclulations. In the future, 1535 * these values may not correspond directly to the zlib compression levels. 1536 */ 1537 #ifdef PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED 1538 PNG_EXPORT(69, void, png_set_compression_level, (png_structrp png_ptr, 1539 int level)); 1540 1541 PNG_EXPORT(70, void, png_set_compression_mem_level, (png_structrp png_ptr, 1542 int mem_level)); 1543 1544 PNG_EXPORT(71, void, png_set_compression_strategy, (png_structrp png_ptr, 1545 int strategy)); 1546 1547 /* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a 1548 * smaller value of window_bits if it can do so safely. 1549 */ 1550 PNG_EXPORT(72, void, png_set_compression_window_bits, (png_structrp png_ptr, 1551 int window_bits)); 1552 1553 PNG_EXPORT(73, void, png_set_compression_method, (png_structrp png_ptr, 1554 int method)); 1555 #endif /* WRITE_CUSTOMIZE_COMPRESSION */ 1556 1557 #ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED 1558 /* Also set zlib parameters for compressing non-IDAT chunks */ 1559 PNG_EXPORT(222, void, png_set_text_compression_level, (png_structrp png_ptr, 1560 int level)); 1561 1562 PNG_EXPORT(223, void, png_set_text_compression_mem_level, (png_structrp png_ptr, 1563 int mem_level)); 1564 1565 PNG_EXPORT(224, void, png_set_text_compression_strategy, (png_structrp png_ptr, 1566 int strategy)); 1567 1568 /* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a 1569 * smaller value of window_bits if it can do so safely. 1570 */ 1571 PNG_EXPORT(225, void, png_set_text_compression_window_bits, 1572 (png_structrp png_ptr, int window_bits)); 1573 1574 PNG_EXPORT(226, void, png_set_text_compression_method, (png_structrp png_ptr, 1575 int method)); 1576 #endif /* WRITE_CUSTOMIZE_ZTXT_COMPRESSION */ 1577 #endif /* WRITE */ 1578 1579 /* These next functions are called for input/output, memory, and error 1580 * handling. They are in the file pngrio.c, pngwio.c, and pngerror.c, 1581 * and call standard C I/O routines such as fread(), fwrite(), and 1582 * fprintf(). These functions can be made to use other I/O routines 1583 * at run time for those applications that need to handle I/O in a 1584 * different manner by calling png_set_???_fn(). See libpng-manual.txt for 1585 * more information. 1586 */ 1587 1588 #ifdef PNG_STDIO_SUPPORTED 1589 /* Initialize the input/output for the PNG file to the default functions. */ 1590 PNG_EXPORT(74, void, png_init_io, (png_structrp png_ptr, png_FILE_p fp)); 1591 #endif 1592 1593 /* Replace the (error and abort), and warning functions with user 1594 * supplied functions. If no messages are to be printed you must still 1595 * write and use replacement functions. The replacement error_fn should 1596 * still do a longjmp to the last setjmp location if you are using this 1597 * method of error handling. If error_fn or warning_fn is NULL, the 1598 * default function will be used. 1599 */ 1600 1601 PNG_EXPORT(75, void, png_set_error_fn, (png_structrp png_ptr, 1602 png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warning_fn)); 1603 1604 /* Return the user pointer associated with the error functions */ 1605 PNG_EXPORT(76, png_voidp, png_get_error_ptr, (png_const_structrp png_ptr)); 1606 1607 /* Replace the default data output functions with a user supplied one(s). 1608 * If buffered output is not used, then output_flush_fn can be set to NULL. 1609 * If PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile time 1610 * output_flush_fn will be ignored (and thus can be NULL). 1611 * It is probably a mistake to use NULL for output_flush_fn if 1612 * write_data_fn is not also NULL unless you have built libpng with 1613 * PNG_WRITE_FLUSH_SUPPORTED undefined, because in this case libpng's 1614 * default flush function, which uses the standard *FILE structure, will 1615 * be used. 1616 */ 1617 PNG_EXPORT(77, void, png_set_write_fn, (png_structrp png_ptr, png_voidp io_ptr, 1618 png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn)); 1619 1620 /* Replace the default data input function with a user supplied one. */ 1621 PNG_EXPORT(78, void, png_set_read_fn, (png_structrp png_ptr, png_voidp io_ptr, 1622 png_rw_ptr read_data_fn)); 1623 1624 /* Return the user pointer associated with the I/O functions */ 1625 PNG_EXPORT(79, png_voidp, png_get_io_ptr, (png_const_structrp png_ptr)); 1626 1627 PNG_EXPORT(80, void, png_set_read_status_fn, (png_structrp png_ptr, 1628 png_read_status_ptr read_row_fn)); 1629 1630 PNG_EXPORT(81, void, png_set_write_status_fn, (png_structrp png_ptr, 1631 png_write_status_ptr write_row_fn)); 1632 1633 #ifdef PNG_USER_MEM_SUPPORTED 1634 /* Replace the default memory allocation functions with user supplied one(s). */ 1635 PNG_EXPORT(82, void, png_set_mem_fn, (png_structrp png_ptr, png_voidp mem_ptr, 1636 png_malloc_ptr malloc_fn, png_free_ptr free_fn)); 1637 /* Return the user pointer associated with the memory functions */ 1638 PNG_EXPORT(83, png_voidp, png_get_mem_ptr, (png_const_structrp png_ptr)); 1639 #endif 1640 1641 #ifdef PNG_READ_USER_TRANSFORM_SUPPORTED 1642 PNG_EXPORT(84, void, png_set_read_user_transform_fn, (png_structrp png_ptr, 1643 png_user_transform_ptr read_user_transform_fn)); 1644 #endif 1645 1646 #ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED 1647 PNG_EXPORT(85, void, png_set_write_user_transform_fn, (png_structrp png_ptr, 1648 png_user_transform_ptr write_user_transform_fn)); 1649 #endif 1650 1651 #ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED 1652 PNG_EXPORT(86, void, png_set_user_transform_info, (png_structrp png_ptr, 1653 png_voidp user_transform_ptr, int user_transform_depth, 1654 int user_transform_channels)); 1655 /* Return the user pointer associated with the user transform functions */ 1656 PNG_EXPORT(87, png_voidp, png_get_user_transform_ptr, 1657 (png_const_structrp png_ptr)); 1658 #endif 1659 1660 #ifdef PNG_USER_TRANSFORM_INFO_SUPPORTED 1661 /* Return information about the row currently being processed. Note that these 1662 * APIs do not fail but will return unexpected results if called outside a user 1663 * transform callback. Also note that when transforming an interlaced image the 1664 * row number is the row number within the sub-image of the interlace pass, so 1665 * the value will increase to the height of the sub-image (not the full image) 1666 * then reset to 0 for the next pass. 1667 * 1668 * Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to 1669 * find the output pixel (x,y) given an interlaced sub-image pixel 1670 * (row,col,pass). (See below for these macros.) 1671 */ 1672 PNG_EXPORT(217, png_uint_32, png_get_current_row_number, (png_const_structrp)); 1673 PNG_EXPORT(218, png_byte, png_get_current_pass_number, (png_const_structrp)); 1674 #endif 1675 1676 #ifdef PNG_READ_USER_CHUNKS_SUPPORTED 1677 /* This callback is called only for *unknown* chunks. If 1678 * PNG_HANDLE_AS_UNKNOWN_SUPPORTED is set then it is possible to set known 1679 * chunks to be treated as unknown, however in this case the callback must do 1680 * any processing required by the chunk (e.g. by calling the appropriate 1681 * png_set_ APIs.) 1682 * 1683 * There is no write support - on write, by default, all the chunks in the 1684 * 'unknown' list are written in the specified position. 1685 * 1686 * The integer return from the callback function is interpreted thus: 1687 * 1688 * negative: An error occurred; png_chunk_error will be called. 1689 * zero: The chunk was not handled, the chunk will be saved. A critical 1690 * chunk will cause an error at this point unless it is to be saved. 1691 * positive: The chunk was handled, libpng will ignore/discard it. 1692 * 1693 * See "INTERACTION WITH USER CHUNK CALLBACKS" below for important notes about 1694 * how this behavior will change in libpng 1.7 1695 */ 1696 PNG_EXPORT(88, void, png_set_read_user_chunk_fn, (png_structrp png_ptr, 1697 png_voidp user_chunk_ptr, png_user_chunk_ptr read_user_chunk_fn)); 1698 #endif 1699 1700 #ifdef PNG_USER_CHUNKS_SUPPORTED 1701 PNG_EXPORT(89, png_voidp, png_get_user_chunk_ptr, (png_const_structrp png_ptr)); 1702 #endif 1703 1704 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED 1705 /* Sets the function callbacks for the push reader, and a pointer to a 1706 * user-defined structure available to the callback functions. 1707 */ 1708 PNG_EXPORT(90, void, png_set_progressive_read_fn, (png_structrp png_ptr, 1709 png_voidp progressive_ptr, png_progressive_info_ptr info_fn, 1710 png_progressive_row_ptr row_fn, png_progressive_end_ptr end_fn)); 1711 1712 /* Returns the user pointer associated with the push read functions */ 1713 PNG_EXPORT(91, png_voidp, png_get_progressive_ptr, 1714 (png_const_structrp png_ptr)); 1715 1716 /* Function to be called when data becomes available */ 1717 PNG_EXPORT(92, void, png_process_data, (png_structrp png_ptr, 1718 png_inforp info_ptr, png_bytep buffer, size_t buffer_size)); 1719 1720 /* A function which may be called *only* within png_process_data to stop the 1721 * processing of any more data. The function returns the number of bytes 1722 * remaining, excluding any that libpng has cached internally. A subsequent 1723 * call to png_process_data must supply these bytes again. If the argument 1724 * 'save' is set to true the routine will first save all the pending data and 1725 * will always return 0. 1726 */ 1727 PNG_EXPORT(219, size_t, png_process_data_pause, (png_structrp, int save)); 1728 1729 /* A function which may be called *only* outside (after) a call to 1730 * png_process_data. It returns the number of bytes of data to skip in the 1731 * input. Normally it will return 0, but if it returns a non-zero value the 1732 * application must skip than number of bytes of input data and pass the 1733 * following data to the next call to png_process_data. 1734 */ 1735 PNG_EXPORT(220, png_uint_32, png_process_data_skip, (png_structrp)); 1736 1737 /* Function that combines rows. 'new_row' is a flag that should come from 1738 * the callback and be non-NULL if anything needs to be done; the library 1739 * stores its own version of the new data internally and ignores the passed 1740 * in value. 1741 */ 1742 PNG_EXPORT(93, void, png_progressive_combine_row, (png_const_structrp png_ptr, 1743 png_bytep old_row, png_const_bytep new_row)); 1744 #endif /* PROGRESSIVE_READ */ 1745 1746 PNG_EXPORTA(94, png_voidp, png_malloc, (png_const_structrp png_ptr, 1747 png_alloc_size_t size), PNG_ALLOCATED); 1748 /* Added at libpng version 1.4.0 */ 1749 PNG_EXPORTA(95, png_voidp, png_calloc, (png_const_structrp png_ptr, 1750 png_alloc_size_t size), PNG_ALLOCATED); 1751 1752 /* Added at libpng version 1.2.4 */ 1753 PNG_EXPORTA(96, png_voidp, png_malloc_warn, (png_const_structrp png_ptr, 1754 png_alloc_size_t size), PNG_ALLOCATED); 1755 1756 /* Frees a pointer allocated by png_malloc() */ 1757 PNG_EXPORT(97, void, png_free, (png_const_structrp png_ptr, png_voidp ptr)); 1758 1759 /* Free data that was allocated internally */ 1760 PNG_EXPORT(98, void, png_free_data, (png_const_structrp png_ptr, 1761 png_inforp info_ptr, png_uint_32 free_me, int num)); 1762 1763 /* Reassign responsibility for freeing existing data, whether allocated 1764 * by libpng or by the application; this works on the png_info structure passed 1765 * in, it does not change the state for other png_info structures. 1766 * 1767 * It is unlikely that this function works correctly as of 1.6.0 and using it 1768 * may result either in memory leaks or double free of allocated data. 1769 */ 1770 PNG_EXPORT(99, void, png_data_freer, (png_const_structrp png_ptr, 1771 png_inforp info_ptr, int freer, png_uint_32 mask)); 1772 1773 /* Assignments for png_data_freer */ 1774 #define PNG_DESTROY_WILL_FREE_DATA 1 1775 #define PNG_SET_WILL_FREE_DATA 1 1776 #define PNG_USER_WILL_FREE_DATA 2 1777 /* Flags for png_ptr->free_me and info_ptr->free_me */ 1778 #define PNG_FREE_HIST 0x0008U 1779 #define PNG_FREE_ICCP 0x0010U 1780 #define PNG_FREE_SPLT 0x0020U 1781 #define PNG_FREE_ROWS 0x0040U 1782 #define PNG_FREE_PCAL 0x0080U 1783 #define PNG_FREE_SCAL 0x0100U 1784 #ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED 1785 # define PNG_FREE_UNKN 0x0200U 1786 #endif 1787 /* PNG_FREE_LIST 0x0400U removed in 1.6.0 because it is ignored */ 1788 #define PNG_FREE_PLTE 0x1000U 1789 #define PNG_FREE_TRNS 0x2000U 1790 #define PNG_FREE_TEXT 0x4000U 1791 #define PNG_FREE_EXIF 0x8000U /* Added at libpng-1.6.31 */ 1792 #define PNG_FREE_ALL 0xffffU 1793 #define PNG_FREE_MUL 0x4220U /* PNG_FREE_SPLT|PNG_FREE_TEXT|PNG_FREE_UNKN */ 1794 1795 #ifdef PNG_USER_MEM_SUPPORTED 1796 PNG_EXPORTA(100, png_voidp, png_malloc_default, (png_const_structrp png_ptr, 1797 png_alloc_size_t size), PNG_ALLOCATED PNG_DEPRECATED); 1798 PNG_EXPORTA(101, void, png_free_default, (png_const_structrp png_ptr, 1799 png_voidp ptr), PNG_DEPRECATED); 1800 #endif 1801 1802 #ifdef PNG_ERROR_TEXT_SUPPORTED 1803 /* Fatal error in PNG image of libpng - can't continue */ 1804 PNG_EXPORTA(102, void, png_error, (png_const_structrp png_ptr, 1805 png_const_charp error_message), PNG_NORETURN); 1806 1807 /* The same, but the chunk name is prepended to the error string. */ 1808 PNG_EXPORTA(103, void, png_chunk_error, (png_const_structrp png_ptr, 1809 png_const_charp error_message), PNG_NORETURN); 1810 1811 #else 1812 /* Fatal error in PNG image of libpng - can't continue */ 1813 PNG_EXPORTA(104, void, png_err, (png_const_structrp png_ptr), PNG_NORETURN); 1814 # define png_error(s1,s2) png_err(s1) 1815 # define png_chunk_error(s1,s2) png_err(s1) 1816 #endif 1817 1818 #ifdef PNG_WARNINGS_SUPPORTED 1819 /* Non-fatal error in libpng. Can continue, but may have a problem. */ 1820 PNG_EXPORT(105, void, png_warning, (png_const_structrp png_ptr, 1821 png_const_charp warning_message)); 1822 1823 /* Non-fatal error in libpng, chunk name is prepended to message. */ 1824 PNG_EXPORT(106, void, png_chunk_warning, (png_const_structrp png_ptr, 1825 png_const_charp warning_message)); 1826 #else 1827 # define png_warning(s1,s2) ((void)(s1)) 1828 # define png_chunk_warning(s1,s2) ((void)(s1)) 1829 #endif 1830 1831 #ifdef PNG_BENIGN_ERRORS_SUPPORTED 1832 /* Benign error in libpng. Can continue, but may have a problem. 1833 * User can choose whether to handle as a fatal error or as a warning. */ 1834 PNG_EXPORT(107, void, png_benign_error, (png_const_structrp png_ptr, 1835 png_const_charp warning_message)); 1836 1837 #ifdef PNG_READ_SUPPORTED 1838 /* Same, chunk name is prepended to message (only during read) */ 1839 PNG_EXPORT(108, void, png_chunk_benign_error, (png_const_structrp png_ptr, 1840 png_const_charp warning_message)); 1841 #endif 1842 1843 PNG_EXPORT(109, void, png_set_benign_errors, 1844 (png_structrp png_ptr, int allowed)); 1845 #else 1846 # ifdef PNG_ALLOW_BENIGN_ERRORS 1847 # define png_benign_error png_warning 1848 # define png_chunk_benign_error png_chunk_warning 1849 # else 1850 # define png_benign_error png_error 1851 # define png_chunk_benign_error png_chunk_error 1852 # endif 1853 #endif 1854 1855 /* The png_set_<chunk> functions are for storing values in the png_info_struct. 1856 * Similarly, the png_get_<chunk> calls are used to read values from the 1857 * png_info_struct, either storing the parameters in the passed variables, or 1858 * setting pointers into the png_info_struct where the data is stored. The 1859 * png_get_<chunk> functions return a non-zero value if the data was available 1860 * in info_ptr, or return zero and do not change any of the parameters if the 1861 * data was not available. 1862 * 1863 * These functions should be used instead of directly accessing png_info 1864 * to avoid problems with future changes in the size and internal layout of 1865 * png_info_struct. 1866 */ 1867 /* Returns "flag" if chunk data is valid in info_ptr. */ 1868 PNG_EXPORT(110, png_uint_32, png_get_valid, (png_const_structrp png_ptr, 1869 png_const_inforp info_ptr, png_uint_32 flag)); 1870 1871 /* Returns number of bytes needed to hold a transformed row. */ 1872 PNG_EXPORT(111, size_t, png_get_rowbytes, (png_const_structrp png_ptr, 1873 png_const_inforp info_ptr)); 1874 1875 #ifdef PNG_INFO_IMAGE_SUPPORTED 1876 /* Returns row_pointers, which is an array of pointers to scanlines that was 1877 * returned from png_read_png(). 1878 */ 1879 PNG_EXPORT(112, png_bytepp, png_get_rows, (png_const_structrp png_ptr, 1880 png_const_inforp info_ptr)); 1881 1882 /* Set row_pointers, which is an array of pointers to scanlines for use 1883 * by png_write_png(). 1884 */ 1885 PNG_EXPORT(113, void, png_set_rows, (png_const_structrp png_ptr, 1886 png_inforp info_ptr, png_bytepp row_pointers)); 1887 #endif 1888 1889 /* Returns number of color channels in image. */ 1890 PNG_EXPORT(114, png_byte, png_get_channels, (png_const_structrp png_ptr, 1891 png_const_inforp info_ptr)); 1892 1893 #ifdef PNG_EASY_ACCESS_SUPPORTED 1894 /* Returns image width in pixels. */ 1895 PNG_EXPORT(115, png_uint_32, png_get_image_width, (png_const_structrp png_ptr, 1896 png_const_inforp info_ptr)); 1897 1898 /* Returns image height in pixels. */ 1899 PNG_EXPORT(116, png_uint_32, png_get_image_height, (png_const_structrp png_ptr, 1900 png_const_inforp info_ptr)); 1901 1902 /* Returns image bit_depth. */ 1903 PNG_EXPORT(117, png_byte, png_get_bit_depth, (png_const_structrp png_ptr, 1904 png_const_inforp info_ptr)); 1905 1906 /* Returns image color_type. */ 1907 PNG_EXPORT(118, png_byte, png_get_color_type, (png_const_structrp png_ptr, 1908 png_const_inforp info_ptr)); 1909 1910 /* Returns image filter_type. */ 1911 PNG_EXPORT(119, png_byte, png_get_filter_type, (png_const_structrp png_ptr, 1912 png_const_inforp info_ptr)); 1913 1914 /* Returns image interlace_type. */ 1915 PNG_EXPORT(120, png_byte, png_get_interlace_type, (png_const_structrp png_ptr, 1916 png_const_inforp info_ptr)); 1917 1918 /* Returns image compression_type. */ 1919 PNG_EXPORT(121, png_byte, png_get_compression_type, (png_const_structrp png_ptr, 1920 png_const_inforp info_ptr)); 1921 1922 /* Returns image resolution in pixels per meter, from pHYs chunk data. */ 1923 PNG_EXPORT(122, png_uint_32, png_get_pixels_per_meter, 1924 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 1925 PNG_EXPORT(123, png_uint_32, png_get_x_pixels_per_meter, 1926 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 1927 PNG_EXPORT(124, png_uint_32, png_get_y_pixels_per_meter, 1928 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 1929 1930 /* Returns pixel aspect ratio, computed from pHYs chunk data. */ 1931 PNG_FP_EXPORT(125, float, png_get_pixel_aspect_ratio, 1932 (png_const_structrp png_ptr, png_const_inforp info_ptr)) 1933 PNG_FIXED_EXPORT(210, png_fixed_point, png_get_pixel_aspect_ratio_fixed, 1934 (png_const_structrp png_ptr, png_const_inforp info_ptr)) 1935 1936 /* Returns image x, y offset in pixels or microns, from oFFs chunk data. */ 1937 PNG_EXPORT(126, png_int_32, png_get_x_offset_pixels, 1938 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 1939 PNG_EXPORT(127, png_int_32, png_get_y_offset_pixels, 1940 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 1941 PNG_EXPORT(128, png_int_32, png_get_x_offset_microns, 1942 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 1943 PNG_EXPORT(129, png_int_32, png_get_y_offset_microns, 1944 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 1945 1946 #endif /* EASY_ACCESS */ 1947 1948 #ifdef PNG_READ_SUPPORTED 1949 /* Returns pointer to signature string read from PNG header */ 1950 PNG_EXPORT(130, png_const_bytep, png_get_signature, (png_const_structrp png_ptr, 1951 png_const_inforp info_ptr)); 1952 #endif 1953 1954 #ifdef PNG_bKGD_SUPPORTED 1955 PNG_EXPORT(131, png_uint_32, png_get_bKGD, (png_const_structrp png_ptr, 1956 png_inforp info_ptr, png_color_16p *background)); 1957 #endif 1958 1959 #ifdef PNG_bKGD_SUPPORTED 1960 PNG_EXPORT(132, void, png_set_bKGD, (png_const_structrp png_ptr, 1961 png_inforp info_ptr, png_const_color_16p background)); 1962 #endif 1963 1964 #ifdef PNG_cHRM_SUPPORTED 1965 PNG_FP_EXPORT(133, png_uint_32, png_get_cHRM, (png_const_structrp png_ptr, 1966 png_const_inforp info_ptr, double *white_x, double *white_y, double *red_x, 1967 double *red_y, double *green_x, double *green_y, double *blue_x, 1968 double *blue_y)) 1969 PNG_FP_EXPORT(230, png_uint_32, png_get_cHRM_XYZ, (png_const_structrp png_ptr, 1970 png_const_inforp info_ptr, double *red_X, double *red_Y, double *red_Z, 1971 double *green_X, double *green_Y, double *green_Z, double *blue_X, 1972 double *blue_Y, double *blue_Z)) 1973 PNG_FIXED_EXPORT(134, png_uint_32, png_get_cHRM_fixed, 1974 (png_const_structrp png_ptr, png_const_inforp info_ptr, 1975 png_fixed_point *int_white_x, png_fixed_point *int_white_y, 1976 png_fixed_point *int_red_x, png_fixed_point *int_red_y, 1977 png_fixed_point *int_green_x, png_fixed_point *int_green_y, 1978 png_fixed_point *int_blue_x, png_fixed_point *int_blue_y)) 1979 PNG_FIXED_EXPORT(231, png_uint_32, png_get_cHRM_XYZ_fixed, 1980 (png_const_structrp png_ptr, png_const_inforp info_ptr, 1981 png_fixed_point *int_red_X, png_fixed_point *int_red_Y, 1982 png_fixed_point *int_red_Z, png_fixed_point *int_green_X, 1983 png_fixed_point *int_green_Y, png_fixed_point *int_green_Z, 1984 png_fixed_point *int_blue_X, png_fixed_point *int_blue_Y, 1985 png_fixed_point *int_blue_Z)) 1986 #endif 1987 1988 #ifdef PNG_cHRM_SUPPORTED 1989 PNG_FP_EXPORT(135, void, png_set_cHRM, (png_const_structrp png_ptr, 1990 png_inforp info_ptr, 1991 double white_x, double white_y, double red_x, double red_y, double green_x, 1992 double green_y, double blue_x, double blue_y)) 1993 PNG_FP_EXPORT(232, void, png_set_cHRM_XYZ, (png_const_structrp png_ptr, 1994 png_inforp info_ptr, double red_X, double red_Y, double red_Z, 1995 double green_X, double green_Y, double green_Z, double blue_X, 1996 double blue_Y, double blue_Z)) 1997 PNG_FIXED_EXPORT(136, void, png_set_cHRM_fixed, (png_const_structrp png_ptr, 1998 png_inforp info_ptr, png_fixed_point int_white_x, 1999 png_fixed_point int_white_y, png_fixed_point int_red_x, 2000 png_fixed_point int_red_y, png_fixed_point int_green_x, 2001 png_fixed_point int_green_y, png_fixed_point int_blue_x, 2002 png_fixed_point int_blue_y)) 2003 PNG_FIXED_EXPORT(233, void, png_set_cHRM_XYZ_fixed, (png_const_structrp png_ptr, 2004 png_inforp info_ptr, png_fixed_point int_red_X, png_fixed_point int_red_Y, 2005 png_fixed_point int_red_Z, png_fixed_point int_green_X, 2006 png_fixed_point int_green_Y, png_fixed_point int_green_Z, 2007 png_fixed_point int_blue_X, png_fixed_point int_blue_Y, 2008 png_fixed_point int_blue_Z)) 2009 #endif 2010 2011 #ifdef PNG_eXIf_SUPPORTED 2012 PNG_EXPORT(246, png_uint_32, png_get_eXIf, (png_const_structrp png_ptr, 2013 png_inforp info_ptr, png_bytep *exif)); 2014 PNG_EXPORT(247, void, png_set_eXIf, (png_const_structrp png_ptr, 2015 png_inforp info_ptr, png_bytep exif)); 2016 2017 PNG_EXPORT(248, png_uint_32, png_get_eXIf_1, (png_const_structrp png_ptr, 2018 png_const_inforp info_ptr, png_uint_32 *num_exif, png_bytep *exif)); 2019 PNG_EXPORT(249, void, png_set_eXIf_1, (png_const_structrp png_ptr, 2020 png_inforp info_ptr, png_uint_32 num_exif, png_bytep exif)); 2021 #endif 2022 2023 #ifdef PNG_gAMA_SUPPORTED 2024 PNG_FP_EXPORT(137, png_uint_32, png_get_gAMA, (png_const_structrp png_ptr, 2025 png_const_inforp info_ptr, double *file_gamma)) 2026 PNG_FIXED_EXPORT(138, png_uint_32, png_get_gAMA_fixed, 2027 (png_const_structrp png_ptr, png_const_inforp info_ptr, 2028 png_fixed_point *int_file_gamma)) 2029 #endif 2030 2031 #ifdef PNG_gAMA_SUPPORTED 2032 PNG_FP_EXPORT(139, void, png_set_gAMA, (png_const_structrp png_ptr, 2033 png_inforp info_ptr, double file_gamma)) 2034 PNG_FIXED_EXPORT(140, void, png_set_gAMA_fixed, (png_const_structrp png_ptr, 2035 png_inforp info_ptr, png_fixed_point int_file_gamma)) 2036 #endif 2037 2038 #ifdef PNG_hIST_SUPPORTED 2039 PNG_EXPORT(141, png_uint_32, png_get_hIST, (png_const_structrp png_ptr, 2040 png_inforp info_ptr, png_uint_16p *hist)); 2041 PNG_EXPORT(142, void, png_set_hIST, (png_const_structrp png_ptr, 2042 png_inforp info_ptr, png_const_uint_16p hist)); 2043 #endif 2044 2045 PNG_EXPORT(143, png_uint_32, png_get_IHDR, (png_const_structrp png_ptr, 2046 png_const_inforp info_ptr, png_uint_32 *width, png_uint_32 *height, 2047 int *bit_depth, int *color_type, int *interlace_method, 2048 int *compression_method, int *filter_method)); 2049 2050 PNG_EXPORT(144, void, png_set_IHDR, (png_const_structrp png_ptr, 2051 png_inforp info_ptr, png_uint_32 width, png_uint_32 height, int bit_depth, 2052 int color_type, int interlace_method, int compression_method, 2053 int filter_method)); 2054 2055 #ifdef PNG_oFFs_SUPPORTED 2056 PNG_EXPORT(145, png_uint_32, png_get_oFFs, (png_const_structrp png_ptr, 2057 png_const_inforp info_ptr, png_int_32 *offset_x, png_int_32 *offset_y, 2058 int *unit_type)); 2059 #endif 2060 2061 #ifdef PNG_oFFs_SUPPORTED 2062 PNG_EXPORT(146, void, png_set_oFFs, (png_const_structrp png_ptr, 2063 png_inforp info_ptr, png_int_32 offset_x, png_int_32 offset_y, 2064 int unit_type)); 2065 #endif 2066 2067 #ifdef PNG_pCAL_SUPPORTED 2068 PNG_EXPORT(147, png_uint_32, png_get_pCAL, (png_const_structrp png_ptr, 2069 png_inforp info_ptr, png_charp *purpose, png_int_32 *X0, 2070 png_int_32 *X1, int *type, int *nparams, png_charp *units, 2071 png_charpp *params)); 2072 #endif 2073 2074 #ifdef PNG_pCAL_SUPPORTED 2075 PNG_EXPORT(148, void, png_set_pCAL, (png_const_structrp png_ptr, 2076 png_inforp info_ptr, png_const_charp purpose, png_int_32 X0, png_int_32 X1, 2077 int type, int nparams, png_const_charp units, png_charpp params)); 2078 #endif 2079 2080 #ifdef PNG_pHYs_SUPPORTED 2081 PNG_EXPORT(149, png_uint_32, png_get_pHYs, (png_const_structrp png_ptr, 2082 png_const_inforp info_ptr, png_uint_32 *res_x, png_uint_32 *res_y, 2083 int *unit_type)); 2084 #endif 2085 2086 #ifdef PNG_pHYs_SUPPORTED 2087 PNG_EXPORT(150, void, png_set_pHYs, (png_const_structrp png_ptr, 2088 png_inforp info_ptr, png_uint_32 res_x, png_uint_32 res_y, int unit_type)); 2089 #endif 2090 2091 PNG_EXPORT(151, png_uint_32, png_get_PLTE, (png_const_structrp png_ptr, 2092 png_inforp info_ptr, png_colorp *palette, int *num_palette)); 2093 2094 PNG_EXPORT(152, void, png_set_PLTE, (png_structrp png_ptr, 2095 png_inforp info_ptr, png_const_colorp palette, int num_palette)); 2096 2097 #ifdef PNG_sBIT_SUPPORTED 2098 PNG_EXPORT(153, png_uint_32, png_get_sBIT, (png_const_structrp png_ptr, 2099 png_inforp info_ptr, png_color_8p *sig_bit)); 2100 #endif 2101 2102 #ifdef PNG_sBIT_SUPPORTED 2103 PNG_EXPORT(154, void, png_set_sBIT, (png_const_structrp png_ptr, 2104 png_inforp info_ptr, png_const_color_8p sig_bit)); 2105 #endif 2106 2107 #ifdef PNG_sRGB_SUPPORTED 2108 PNG_EXPORT(155, png_uint_32, png_get_sRGB, (png_const_structrp png_ptr, 2109 png_const_inforp info_ptr, int *file_srgb_intent)); 2110 #endif 2111 2112 #ifdef PNG_sRGB_SUPPORTED 2113 PNG_EXPORT(156, void, png_set_sRGB, (png_const_structrp png_ptr, 2114 png_inforp info_ptr, int srgb_intent)); 2115 PNG_EXPORT(157, void, png_set_sRGB_gAMA_and_cHRM, (png_const_structrp png_ptr, 2116 png_inforp info_ptr, int srgb_intent)); 2117 #endif 2118 2119 #ifdef PNG_iCCP_SUPPORTED 2120 PNG_EXPORT(158, png_uint_32, png_get_iCCP, (png_const_structrp png_ptr, 2121 png_inforp info_ptr, png_charpp name, int *compression_type, 2122 png_bytepp profile, png_uint_32 *proflen)); 2123 #endif 2124 2125 #ifdef PNG_iCCP_SUPPORTED 2126 PNG_EXPORT(159, void, png_set_iCCP, (png_const_structrp png_ptr, 2127 png_inforp info_ptr, png_const_charp name, int compression_type, 2128 png_const_bytep profile, png_uint_32 proflen)); 2129 #endif 2130 2131 #ifdef PNG_sPLT_SUPPORTED 2132 PNG_EXPORT(160, int, png_get_sPLT, (png_const_structrp png_ptr, 2133 png_inforp info_ptr, png_sPLT_tpp entries)); 2134 #endif 2135 2136 #ifdef PNG_sPLT_SUPPORTED 2137 PNG_EXPORT(161, void, png_set_sPLT, (png_const_structrp png_ptr, 2138 png_inforp info_ptr, png_const_sPLT_tp entries, int nentries)); 2139 #endif 2140 2141 #ifdef PNG_TEXT_SUPPORTED 2142 /* png_get_text also returns the number of text chunks in *num_text */ 2143 PNG_EXPORT(162, int, png_get_text, (png_const_structrp png_ptr, 2144 png_inforp info_ptr, png_textp *text_ptr, int *num_text)); 2145 #endif 2146 2147 /* Note while png_set_text() will accept a structure whose text, 2148 * language, and translated keywords are NULL pointers, the structure 2149 * returned by png_get_text will always contain regular 2150 * zero-terminated C strings. They might be empty strings but 2151 * they will never be NULL pointers. 2152 */ 2153 2154 #ifdef PNG_TEXT_SUPPORTED 2155 PNG_EXPORT(163, void, png_set_text, (png_const_structrp png_ptr, 2156 png_inforp info_ptr, png_const_textp text_ptr, int num_text)); 2157 #endif 2158 2159 #ifdef PNG_tIME_SUPPORTED 2160 PNG_EXPORT(164, png_uint_32, png_get_tIME, (png_const_structrp png_ptr, 2161 png_inforp info_ptr, png_timep *mod_time)); 2162 #endif 2163 2164 #ifdef PNG_tIME_SUPPORTED 2165 PNG_EXPORT(165, void, png_set_tIME, (png_const_structrp png_ptr, 2166 png_inforp info_ptr, png_const_timep mod_time)); 2167 #endif 2168 2169 #ifdef PNG_tRNS_SUPPORTED 2170 PNG_EXPORT(166, png_uint_32, png_get_tRNS, (png_const_structrp png_ptr, 2171 png_inforp info_ptr, png_bytep *trans_alpha, int *num_trans, 2172 png_color_16p *trans_color)); 2173 #endif 2174 2175 #ifdef PNG_tRNS_SUPPORTED 2176 PNG_EXPORT(167, void, png_set_tRNS, (png_structrp png_ptr, 2177 png_inforp info_ptr, png_const_bytep trans_alpha, int num_trans, 2178 png_const_color_16p trans_color)); 2179 #endif 2180 2181 #ifdef PNG_sCAL_SUPPORTED 2182 PNG_FP_EXPORT(168, png_uint_32, png_get_sCAL, (png_const_structrp png_ptr, 2183 png_const_inforp info_ptr, int *unit, double *width, double *height)) 2184 #if defined(PNG_FLOATING_ARITHMETIC_SUPPORTED) || \ 2185 defined(PNG_FLOATING_POINT_SUPPORTED) 2186 /* NOTE: this API is currently implemented using floating point arithmetic, 2187 * consequently it can only be used on systems with floating point support. 2188 * In any case the range of values supported by png_fixed_point is small and it 2189 * is highly recommended that png_get_sCAL_s be used instead. 2190 */ 2191 PNG_FIXED_EXPORT(214, png_uint_32, png_get_sCAL_fixed, 2192 (png_const_structrp png_ptr, png_const_inforp info_ptr, int *unit, 2193 png_fixed_point *width, png_fixed_point *height)) 2194 #endif 2195 PNG_EXPORT(169, png_uint_32, png_get_sCAL_s, 2196 (png_const_structrp png_ptr, png_const_inforp info_ptr, int *unit, 2197 png_charpp swidth, png_charpp sheight)); 2198 2199 PNG_FP_EXPORT(170, void, png_set_sCAL, (png_const_structrp png_ptr, 2200 png_inforp info_ptr, int unit, double width, double height)) 2201 PNG_FIXED_EXPORT(213, void, png_set_sCAL_fixed, (png_const_structrp png_ptr, 2202 png_inforp info_ptr, int unit, png_fixed_point width, 2203 png_fixed_point height)) 2204 PNG_EXPORT(171, void, png_set_sCAL_s, (png_const_structrp png_ptr, 2205 png_inforp info_ptr, int unit, 2206 png_const_charp swidth, png_const_charp sheight)); 2207 #endif /* sCAL */ 2208 2209 #ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED 2210 /* Provide the default handling for all unknown chunks or, optionally, for 2211 * specific unknown chunks. 2212 * 2213 * NOTE: prior to 1.6.0 the handling specified for particular chunks on read was 2214 * ignored and the default was used, the per-chunk setting only had an effect on 2215 * write. If you wish to have chunk-specific handling on read in code that must 2216 * work on earlier versions you must use a user chunk callback to specify the 2217 * desired handling (keep or discard.) 2218 * 2219 * The 'keep' parameter is a PNG_HANDLE_CHUNK_ value as listed below. The 2220 * parameter is interpreted as follows: 2221 * 2222 * READ: 2223 * PNG_HANDLE_CHUNK_AS_DEFAULT: 2224 * Known chunks: do normal libpng processing, do not keep the chunk (but 2225 * see the comments below about PNG_HANDLE_AS_UNKNOWN_SUPPORTED) 2226 * Unknown chunks: for a specific chunk use the global default, when used 2227 * as the default discard the chunk data. 2228 * PNG_HANDLE_CHUNK_NEVER: 2229 * Discard the chunk data. 2230 * PNG_HANDLE_CHUNK_IF_SAFE: 2231 * Keep the chunk data if the chunk is not critical else raise a chunk 2232 * error. 2233 * PNG_HANDLE_CHUNK_ALWAYS: 2234 * Keep the chunk data. 2235 * 2236 * If the chunk data is saved it can be retrieved using png_get_unknown_chunks, 2237 * below. Notice that specifying "AS_DEFAULT" as a global default is equivalent 2238 * to specifying "NEVER", however when "AS_DEFAULT" is used for specific chunks 2239 * it simply resets the behavior to the libpng default. 2240 * 2241 * INTERACTION WITH USER CHUNK CALLBACKS: 2242 * The per-chunk handling is always used when there is a png_user_chunk_ptr 2243 * callback and the callback returns 0; the chunk is then always stored *unless* 2244 * it is critical and the per-chunk setting is other than ALWAYS. Notice that 2245 * the global default is *not* used in this case. (In effect the per-chunk 2246 * value is incremented to at least IF_SAFE.) 2247 * 2248 * IMPORTANT NOTE: this behavior will change in libpng 1.7 - the global and 2249 * per-chunk defaults will be honored. If you want to preserve the current 2250 * behavior when your callback returns 0 you must set PNG_HANDLE_CHUNK_IF_SAFE 2251 * as the default - if you don't do this libpng 1.6 will issue a warning. 2252 * 2253 * If you want unhandled unknown chunks to be discarded in libpng 1.6 and 2254 * earlier simply return '1' (handled). 2255 * 2256 * PNG_HANDLE_AS_UNKNOWN_SUPPORTED: 2257 * If this is *not* set known chunks will always be handled by libpng and 2258 * will never be stored in the unknown chunk list. Known chunks listed to 2259 * png_set_keep_unknown_chunks will have no effect. If it is set then known 2260 * chunks listed with a keep other than AS_DEFAULT will *never* be processed 2261 * by libpng, in addition critical chunks must either be processed by the 2262 * callback or saved. 2263 * 2264 * The IHDR and IEND chunks must not be listed. Because this turns off the 2265 * default handling for chunks that would otherwise be recognized the 2266 * behavior of libpng transformations may well become incorrect! 2267 * 2268 * WRITE: 2269 * When writing chunks the options only apply to the chunks specified by 2270 * png_set_unknown_chunks (below), libpng will *always* write known chunks 2271 * required by png_set_ calls and will always write the core critical chunks 2272 * (as required for PLTE). 2273 * 2274 * Each chunk in the png_set_unknown_chunks list is looked up in the 2275 * png_set_keep_unknown_chunks list to find the keep setting, this is then 2276 * interpreted as follows: 2277 * 2278 * PNG_HANDLE_CHUNK_AS_DEFAULT: 2279 * Write safe-to-copy chunks and write other chunks if the global 2280 * default is set to _ALWAYS, otherwise don't write this chunk. 2281 * PNG_HANDLE_CHUNK_NEVER: 2282 * Do not write the chunk. 2283 * PNG_HANDLE_CHUNK_IF_SAFE: 2284 * Write the chunk if it is safe-to-copy, otherwise do not write it. 2285 * PNG_HANDLE_CHUNK_ALWAYS: 2286 * Write the chunk. 2287 * 2288 * Note that the default behavior is effectively the opposite of the read case - 2289 * in read unknown chunks are not stored by default, in write they are written 2290 * by default. Also the behavior of PNG_HANDLE_CHUNK_IF_SAFE is very different 2291 * - on write the safe-to-copy bit is checked, on read the critical bit is 2292 * checked and on read if the chunk is critical an error will be raised. 2293 * 2294 * num_chunks: 2295 * =========== 2296 * If num_chunks is positive, then the "keep" parameter specifies the manner 2297 * for handling only those chunks appearing in the chunk_list array, 2298 * otherwise the chunk list array is ignored. 2299 * 2300 * If num_chunks is 0 the "keep" parameter specifies the default behavior for 2301 * unknown chunks, as described above. 2302 * 2303 * If num_chunks is negative, then the "keep" parameter specifies the manner 2304 * for handling all unknown chunks plus all chunks recognized by libpng 2305 * except for the IHDR, PLTE, tRNS, IDAT, and IEND chunks (which continue to 2306 * be processed by libpng. 2307 */ 2308 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED 2309 PNG_EXPORT(172, void, png_set_keep_unknown_chunks, (png_structrp png_ptr, 2310 int keep, png_const_bytep chunk_list, int num_chunks)); 2311 #endif /* HANDLE_AS_UNKNOWN */ 2312 2313 /* The "keep" PNG_HANDLE_CHUNK_ parameter for the specified chunk is returned; 2314 * the result is therefore true (non-zero) if special handling is required, 2315 * false for the default handling. 2316 */ 2317 PNG_EXPORT(173, int, png_handle_as_unknown, (png_const_structrp png_ptr, 2318 png_const_bytep chunk_name)); 2319 #endif /* SET_UNKNOWN_CHUNKS */ 2320 2321 #ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED 2322 PNG_EXPORT(174, void, png_set_unknown_chunks, (png_const_structrp png_ptr, 2323 png_inforp info_ptr, png_const_unknown_chunkp unknowns, 2324 int num_unknowns)); 2325 /* NOTE: prior to 1.6.0 this routine set the 'location' field of the added 2326 * unknowns to the location currently stored in the png_struct. This is 2327 * invariably the wrong value on write. To fix this call the following API 2328 * for each chunk in the list with the correct location. If you know your 2329 * code won't be compiled on earlier versions you can rely on 2330 * png_set_unknown_chunks(write-ptr, png_get_unknown_chunks(read-ptr)) doing 2331 * the correct thing. 2332 */ 2333 2334 PNG_EXPORT(175, void, png_set_unknown_chunk_location, 2335 (png_const_structrp png_ptr, png_inforp info_ptr, int chunk, int location)); 2336 2337 PNG_EXPORT(176, int, png_get_unknown_chunks, (png_const_structrp png_ptr, 2338 png_inforp info_ptr, png_unknown_chunkpp entries)); 2339 #endif 2340 2341 /* Png_free_data() will turn off the "valid" flag for anything it frees. 2342 * If you need to turn it off for a chunk that your application has freed, 2343 * you can use png_set_invalid(png_ptr, info_ptr, PNG_INFO_CHNK); 2344 */ 2345 PNG_EXPORT(177, void, png_set_invalid, (png_const_structrp png_ptr, 2346 png_inforp info_ptr, int mask)); 2347 2348 #ifdef PNG_INFO_IMAGE_SUPPORTED 2349 /* The "params" pointer is currently not used and is for future expansion. */ 2350 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED 2351 PNG_EXPORT(178, void, png_read_png, (png_structrp png_ptr, png_inforp info_ptr, 2352 int transforms, png_voidp params)); 2353 #endif 2354 #ifdef PNG_WRITE_SUPPORTED 2355 PNG_EXPORT(179, void, png_write_png, (png_structrp png_ptr, png_inforp info_ptr, 2356 int transforms, png_voidp params)); 2357 #endif 2358 #endif 2359 2360 PNG_EXPORT(180, png_const_charp, png_get_copyright, 2361 (png_const_structrp png_ptr)); 2362 PNG_EXPORT(181, png_const_charp, png_get_header_ver, 2363 (png_const_structrp png_ptr)); 2364 PNG_EXPORT(182, png_const_charp, png_get_header_version, 2365 (png_const_structrp png_ptr)); 2366 PNG_EXPORT(183, png_const_charp, png_get_libpng_ver, 2367 (png_const_structrp png_ptr)); 2368 2369 #ifdef PNG_MNG_FEATURES_SUPPORTED 2370 PNG_EXPORT(184, png_uint_32, png_permit_mng_features, (png_structrp png_ptr, 2371 png_uint_32 mng_features_permitted)); 2372 #endif 2373 2374 /* For use in png_set_keep_unknown, added to version 1.2.6 */ 2375 #define PNG_HANDLE_CHUNK_AS_DEFAULT 0 2376 #define PNG_HANDLE_CHUNK_NEVER 1 2377 #define PNG_HANDLE_CHUNK_IF_SAFE 2 2378 #define PNG_HANDLE_CHUNK_ALWAYS 3 2379 #define PNG_HANDLE_CHUNK_LAST 4 2380 2381 /* Strip the prepended error numbers ("#nnn ") from error and warning 2382 * messages before passing them to the error or warning handler. 2383 */ 2384 #ifdef PNG_ERROR_NUMBERS_SUPPORTED 2385 PNG_EXPORT(185, void, png_set_strip_error_numbers, (png_structrp png_ptr, 2386 png_uint_32 strip_mode)); 2387 #endif 2388 2389 /* Added in libpng-1.2.6 */ 2390 #ifdef PNG_SET_USER_LIMITS_SUPPORTED 2391 PNG_EXPORT(186, void, png_set_user_limits, (png_structrp png_ptr, 2392 png_uint_32 user_width_max, png_uint_32 user_height_max)); 2393 PNG_EXPORT(187, png_uint_32, png_get_user_width_max, 2394 (png_const_structrp png_ptr)); 2395 PNG_EXPORT(188, png_uint_32, png_get_user_height_max, 2396 (png_const_structrp png_ptr)); 2397 /* Added in libpng-1.4.0 */ 2398 PNG_EXPORT(189, void, png_set_chunk_cache_max, (png_structrp png_ptr, 2399 png_uint_32 user_chunk_cache_max)); 2400 PNG_EXPORT(190, png_uint_32, png_get_chunk_cache_max, 2401 (png_const_structrp png_ptr)); 2402 /* Added in libpng-1.4.1 */ 2403 PNG_EXPORT(191, void, png_set_chunk_malloc_max, (png_structrp png_ptr, 2404 png_alloc_size_t user_chunk_cache_max)); 2405 PNG_EXPORT(192, png_alloc_size_t, png_get_chunk_malloc_max, 2406 (png_const_structrp png_ptr)); 2407 #endif 2408 2409 #if defined(PNG_INCH_CONVERSIONS_SUPPORTED) 2410 PNG_EXPORT(193, png_uint_32, png_get_pixels_per_inch, 2411 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 2412 2413 PNG_EXPORT(194, png_uint_32, png_get_x_pixels_per_inch, 2414 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 2415 2416 PNG_EXPORT(195, png_uint_32, png_get_y_pixels_per_inch, 2417 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 2418 2419 PNG_FP_EXPORT(196, float, png_get_x_offset_inches, 2420 (png_const_structrp png_ptr, png_const_inforp info_ptr)) 2421 #ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */ 2422 PNG_FIXED_EXPORT(211, png_fixed_point, png_get_x_offset_inches_fixed, 2423 (png_const_structrp png_ptr, png_const_inforp info_ptr)) 2424 #endif 2425 2426 PNG_FP_EXPORT(197, float, png_get_y_offset_inches, (png_const_structrp png_ptr, 2427 png_const_inforp info_ptr)) 2428 #ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */ 2429 PNG_FIXED_EXPORT(212, png_fixed_point, png_get_y_offset_inches_fixed, 2430 (png_const_structrp png_ptr, png_const_inforp info_ptr)) 2431 #endif 2432 2433 # ifdef PNG_pHYs_SUPPORTED 2434 PNG_EXPORT(198, png_uint_32, png_get_pHYs_dpi, (png_const_structrp png_ptr, 2435 png_const_inforp info_ptr, png_uint_32 *res_x, png_uint_32 *res_y, 2436 int *unit_type)); 2437 # endif /* pHYs */ 2438 #endif /* INCH_CONVERSIONS */ 2439 2440 /* Added in libpng-1.4.0 */ 2441 #ifdef PNG_IO_STATE_SUPPORTED 2442 PNG_EXPORT(199, png_uint_32, png_get_io_state, (png_const_structrp png_ptr)); 2443 2444 /* Removed from libpng 1.6; use png_get_io_chunk_type. */ 2445 PNG_REMOVED(200, png_const_bytep, png_get_io_chunk_name, (png_structrp png_ptr), 2446 PNG_DEPRECATED) 2447 2448 PNG_EXPORT(216, png_uint_32, png_get_io_chunk_type, 2449 (png_const_structrp png_ptr)); 2450 2451 /* The flags returned by png_get_io_state() are the following: */ 2452 # define PNG_IO_NONE 0x0000 /* no I/O at this moment */ 2453 # define PNG_IO_READING 0x0001 /* currently reading */ 2454 # define PNG_IO_WRITING 0x0002 /* currently writing */ 2455 # define PNG_IO_SIGNATURE 0x0010 /* currently at the file signature */ 2456 # define PNG_IO_CHUNK_HDR 0x0020 /* currently at the chunk header */ 2457 # define PNG_IO_CHUNK_DATA 0x0040 /* currently at the chunk data */ 2458 # define PNG_IO_CHUNK_CRC 0x0080 /* currently at the chunk crc */ 2459 # define PNG_IO_MASK_OP 0x000f /* current operation: reading/writing */ 2460 # define PNG_IO_MASK_LOC 0x00f0 /* current location: sig/hdr/data/crc */ 2461 #endif /* IO_STATE */ 2462 2463 /* Interlace support. The following macros are always defined so that if 2464 * libpng interlace handling is turned off the macros may be used to handle 2465 * interlaced images within the application. 2466 */ 2467 #define PNG_INTERLACE_ADAM7_PASSES 7 2468 2469 /* Two macros to return the first row and first column of the original, 2470 * full, image which appears in a given pass. 'pass' is in the range 0 2471 * to 6 and the result is in the range 0 to 7. 2472 */ 2473 #define PNG_PASS_START_ROW(pass) (((1&~(pass))<<(3-((pass)>>1)))&7) 2474 #define PNG_PASS_START_COL(pass) (((1& (pass))<<(3-(((pass)+1)>>1)))&7) 2475 2476 /* A macro to return the offset between pixels in the output row for a pair of 2477 * pixels in the input - effectively the inverse of the 'COL_SHIFT' macro that 2478 * follows. Note that ROW_OFFSET is the offset from one row to the next whereas 2479 * COL_OFFSET is from one column to the next, within a row. 2480 */ 2481 #define PNG_PASS_ROW_OFFSET(pass) ((pass)>2?(8>>(((pass)-1)>>1)):8) 2482 #define PNG_PASS_COL_OFFSET(pass) (1<<((7-(pass))>>1)) 2483 2484 /* Two macros to help evaluate the number of rows or columns in each 2485 * pass. This is expressed as a shift - effectively log2 of the number or 2486 * rows or columns in each 8x8 tile of the original image. 2487 */ 2488 #define PNG_PASS_ROW_SHIFT(pass) ((pass)>2?(8-(pass))>>1:3) 2489 #define PNG_PASS_COL_SHIFT(pass) ((pass)>1?(7-(pass))>>1:3) 2490 2491 /* Hence two macros to determine the number of rows or columns in a given 2492 * pass of an image given its height or width. In fact these macros may 2493 * return non-zero even though the sub-image is empty, because the other 2494 * dimension may be empty for a small image. 2495 */ 2496 #define PNG_PASS_ROWS(height, pass) (((height)+(((1<<PNG_PASS_ROW_SHIFT(pass))\ 2497 -1)-PNG_PASS_START_ROW(pass)))>>PNG_PASS_ROW_SHIFT(pass)) 2498 #define PNG_PASS_COLS(width, pass) (((width)+(((1<<PNG_PASS_COL_SHIFT(pass))\ 2499 -1)-PNG_PASS_START_COL(pass)))>>PNG_PASS_COL_SHIFT(pass)) 2500 2501 /* For the reader row callbacks (both progressive and sequential) it is 2502 * necessary to find the row in the output image given a row in an interlaced 2503 * image, so two more macros: 2504 */ 2505 #define PNG_ROW_FROM_PASS_ROW(y_in, pass) \ 2506 (((y_in)<<PNG_PASS_ROW_SHIFT(pass))+PNG_PASS_START_ROW(pass)) 2507 #define PNG_COL_FROM_PASS_COL(x_in, pass) \ 2508 (((x_in)<<PNG_PASS_COL_SHIFT(pass))+PNG_PASS_START_COL(pass)) 2509 2510 /* Two macros which return a boolean (0 or 1) saying whether the given row 2511 * or column is in a particular pass. These use a common utility macro that 2512 * returns a mask for a given pass - the offset 'off' selects the row or 2513 * column version. The mask has the appropriate bit set for each column in 2514 * the tile. 2515 */ 2516 #define PNG_PASS_MASK(pass,off) ( \ 2517 ((0x110145AF>>(((7-(off))-(pass))<<2)) & 0xF) | \ 2518 ((0x01145AF0>>(((7-(off))-(pass))<<2)) & 0xF0)) 2519 2520 #define PNG_ROW_IN_INTERLACE_PASS(y, pass) \ 2521 ((PNG_PASS_MASK(pass,0) >> ((y)&7)) & 1) 2522 #define PNG_COL_IN_INTERLACE_PASS(x, pass) \ 2523 ((PNG_PASS_MASK(pass,1) >> ((x)&7)) & 1) 2524 2525 #ifdef PNG_READ_COMPOSITE_NODIV_SUPPORTED 2526 /* With these routines we avoid an integer divide, which will be slower on 2527 * most machines. However, it does take more operations than the corresponding 2528 * divide method, so it may be slower on a few RISC systems. There are two 2529 * shifts (by 8 or 16 bits) and an addition, versus a single integer divide. 2530 * 2531 * Note that the rounding factors are NOT supposed to be the same! 128 and 2532 * 32768 are correct for the NODIV code; 127 and 32767 are correct for the 2533 * standard method. 2534 * 2535 * [Optimized code by Greg Roelofs and Mark Adler...blame us for bugs. :-) ] 2536 */ 2537 2538 /* fg and bg should be in `gamma 1.0' space; alpha is the opacity */ 2539 2540 # define png_composite(composite, fg, alpha, bg) \ 2541 { \ 2542 png_uint_16 temp = (png_uint_16)((png_uint_16)(fg) \ 2543 * (png_uint_16)(alpha) \ 2544 + (png_uint_16)(bg)*(png_uint_16)(255 \ 2545 - (png_uint_16)(alpha)) + 128); \ 2546 (composite) = (png_byte)(((temp + (temp >> 8)) >> 8) & 0xff); \ 2547 } 2548 2549 # define png_composite_16(composite, fg, alpha, bg) \ 2550 { \ 2551 png_uint_32 temp = (png_uint_32)((png_uint_32)(fg) \ 2552 * (png_uint_32)(alpha) \ 2553 + (png_uint_32)(bg)*(65535 \ 2554 - (png_uint_32)(alpha)) + 32768); \ 2555 (composite) = (png_uint_16)(0xffff & ((temp + (temp >> 16)) >> 16)); \ 2556 } 2557 2558 #else /* Standard method using integer division */ 2559 2560 # define png_composite(composite, fg, alpha, bg) \ 2561 (composite) = \ 2562 (png_byte)(0xff & (((png_uint_16)(fg) * (png_uint_16)(alpha) + \ 2563 (png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) + \ 2564 127) / 255)) 2565 2566 # define png_composite_16(composite, fg, alpha, bg) \ 2567 (composite) = \ 2568 (png_uint_16)(0xffff & (((png_uint_32)(fg) * (png_uint_32)(alpha) + \ 2569 (png_uint_32)(bg)*(png_uint_32)(65535 - (png_uint_32)(alpha)) + \ 2570 32767) / 65535)) 2571 #endif /* READ_COMPOSITE_NODIV */ 2572 2573 #ifdef PNG_READ_INT_FUNCTIONS_SUPPORTED 2574 PNG_EXPORT(201, png_uint_32, png_get_uint_32, (png_const_bytep buf)); 2575 PNG_EXPORT(202, png_uint_16, png_get_uint_16, (png_const_bytep buf)); 2576 PNG_EXPORT(203, png_int_32, png_get_int_32, (png_const_bytep buf)); 2577 #endif 2578 2579 PNG_EXPORT(204, png_uint_32, png_get_uint_31, (png_const_structrp png_ptr, 2580 png_const_bytep buf)); 2581 /* No png_get_int_16 -- may be added if there's a real need for it. */ 2582 2583 /* Place a 32-bit number into a buffer in PNG byte order (big-endian). */ 2584 #ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED 2585 PNG_EXPORT(205, void, png_save_uint_32, (png_bytep buf, png_uint_32 i)); 2586 #endif 2587 #ifdef PNG_SAVE_INT_32_SUPPORTED 2588 PNG_EXPORT(206, void, png_save_int_32, (png_bytep buf, png_int_32 i)); 2589 #endif 2590 2591 /* Place a 16-bit number into a buffer in PNG byte order. 2592 * The parameter is declared unsigned int, not png_uint_16, 2593 * just to avoid potential problems on pre-ANSI C compilers. 2594 */ 2595 #ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED 2596 PNG_EXPORT(207, void, png_save_uint_16, (png_bytep buf, unsigned int i)); 2597 /* No png_save_int_16 -- may be added if there's a real need for it. */ 2598 #endif 2599 2600 #ifdef PNG_USE_READ_MACROS 2601 /* Inline macros to do direct reads of bytes from the input buffer. 2602 * The png_get_int_32() routine assumes we are using two's complement 2603 * format for negative values, which is almost certainly true. 2604 */ 2605 # define PNG_get_uint_32(buf) \ 2606 (((png_uint_32)(*(buf)) << 24) + \ 2607 ((png_uint_32)(*((buf) + 1)) << 16) + \ 2608 ((png_uint_32)(*((buf) + 2)) << 8) + \ 2609 ((png_uint_32)(*((buf) + 3)))) 2610 2611 /* From libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the 2612 * function) incorrectly returned a value of type png_uint_32. 2613 */ 2614 # define PNG_get_uint_16(buf) \ 2615 ((png_uint_16) \ 2616 (((unsigned int)(*(buf)) << 8) + \ 2617 ((unsigned int)(*((buf) + 1))))) 2618 2619 # define PNG_get_int_32(buf) \ 2620 ((png_int_32)((*(buf) & 0x80) \ 2621 ? -((png_int_32)(((png_get_uint_32(buf)^0xffffffffU)+1U)&0x7fffffffU)) \ 2622 : (png_int_32)png_get_uint_32(buf))) 2623 2624 /* If PNG_PREFIX is defined the same thing as below happens in pnglibconf.h, 2625 * but defining a macro name prefixed with PNG_PREFIX. 2626 */ 2627 # ifndef PNG_PREFIX 2628 # define png_get_uint_32(buf) PNG_get_uint_32(buf) 2629 # define png_get_uint_16(buf) PNG_get_uint_16(buf) 2630 # define png_get_int_32(buf) PNG_get_int_32(buf) 2631 # endif 2632 #else 2633 # ifdef PNG_PREFIX 2634 /* No macros; revert to the (redefined) function */ 2635 # define PNG_get_uint_32 (png_get_uint_32) 2636 # define PNG_get_uint_16 (png_get_uint_16) 2637 # define PNG_get_int_32 (png_get_int_32) 2638 # endif 2639 #endif 2640 2641 #ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED 2642 PNG_EXPORT(242, void, png_set_check_for_invalid_index, 2643 (png_structrp png_ptr, int allowed)); 2644 # ifdef PNG_GET_PALETTE_MAX_SUPPORTED 2645 PNG_EXPORT(243, int, png_get_palette_max, (png_const_structp png_ptr, 2646 png_const_infop info_ptr)); 2647 # endif 2648 #endif /* CHECK_FOR_INVALID_INDEX */ 2649 2650 /******************************************************************************* 2651 * Section 5: SIMPLIFIED API 2652 ******************************************************************************* 2653 * 2654 * Please read the documentation in libpng-manual.txt (TODO: write said 2655 * documentation) if you don't understand what follows. 2656 * 2657 * The simplified API hides the details of both libpng and the PNG file format 2658 * itself. It allows PNG files to be read into a very limited number of 2659 * in-memory bitmap formats or to be written from the same formats. If these 2660 * formats do not accommodate your needs then you can, and should, use the more 2661 * sophisticated APIs above - these support a wide variety of in-memory formats 2662 * and a wide variety of sophisticated transformations to those formats as well 2663 * as a wide variety of APIs to manipulate ancillary information. 2664 * 2665 * To read a PNG file using the simplified API: 2666 * 2667 * 1) Declare a 'png_image' structure (see below) on the stack, set the 2668 * version field to PNG_IMAGE_VERSION and the 'opaque' pointer to NULL 2669 * (this is REQUIRED, your program may crash if you don't do it.) 2670 * 2) Call the appropriate png_image_begin_read... function. 2671 * 3) Set the png_image 'format' member to the required sample format. 2672 * 4) Allocate a buffer for the image and, if required, the color-map. 2673 * 5) Call png_image_finish_read to read the image and, if required, the 2674 * color-map into your buffers. 2675 * 2676 * There are no restrictions on the format of the PNG input itself; all valid 2677 * color types, bit depths, and interlace methods are acceptable, and the 2678 * input image is transformed as necessary to the requested in-memory format 2679 * during the png_image_finish_read() step. The only caveat is that if you 2680 * request a color-mapped image from a PNG that is full-color or makes 2681 * complex use of an alpha channel the transformation is extremely lossy and the 2682 * result may look terrible. 2683 * 2684 * To write a PNG file using the simplified API: 2685 * 2686 * 1) Declare a 'png_image' structure on the stack and memset() it to all zero. 2687 * 2) Initialize the members of the structure that describe the image, setting 2688 * the 'format' member to the format of the image samples. 2689 * 3) Call the appropriate png_image_write... function with a pointer to the 2690 * image and, if necessary, the color-map to write the PNG data. 2691 * 2692 * png_image is a structure that describes the in-memory format of an image 2693 * when it is being read or defines the in-memory format of an image that you 2694 * need to write: 2695 */ 2696 #if defined(PNG_SIMPLIFIED_READ_SUPPORTED) || \ 2697 defined(PNG_SIMPLIFIED_WRITE_SUPPORTED) 2698 2699 #define PNG_IMAGE_VERSION 1 2700 2701 typedef struct png_control *png_controlp; 2702 typedef struct 2703 { 2704 png_controlp opaque; /* Initialize to NULL, free with png_image_free */ 2705 png_uint_32 version; /* Set to PNG_IMAGE_VERSION */ 2706 png_uint_32 width; /* Image width in pixels (columns) */ 2707 png_uint_32 height; /* Image height in pixels (rows) */ 2708 png_uint_32 format; /* Image format as defined below */ 2709 png_uint_32 flags; /* A bit mask containing informational flags */ 2710 png_uint_32 colormap_entries; 2711 /* Number of entries in the color-map */ 2712 2713 /* In the event of an error or warning the following field will be set to a 2714 * non-zero value and the 'message' field will contain a '\0' terminated 2715 * string with the libpng error or warning message. If both warnings and 2716 * an error were encountered, only the error is recorded. If there 2717 * are multiple warnings, only the first one is recorded. 2718 * 2719 * The upper 30 bits of this value are reserved, the low two bits contain 2720 * a value as follows: 2721 */ 2722 # define PNG_IMAGE_WARNING 1 2723 # define PNG_IMAGE_ERROR 2 2724 /* 2725 * The result is a two-bit code such that a value more than 1 indicates 2726 * a failure in the API just called: 2727 * 2728 * 0 - no warning or error 2729 * 1 - warning 2730 * 2 - error 2731 * 3 - error preceded by warning 2732 */ 2733 # define PNG_IMAGE_FAILED(png_cntrl) ((((png_cntrl).warning_or_error)&0x03)>1) 2734 2735 png_uint_32 warning_or_error; 2736 2737 char message[64]; 2738 } png_image, *png_imagep; 2739 2740 /* The samples of the image have one to four channels whose components have 2741 * original values in the range 0 to 1.0: 2742 * 2743 * 1: A single gray or luminance channel (G). 2744 * 2: A gray/luminance channel and an alpha channel (GA). 2745 * 3: Three red, green, blue color channels (RGB). 2746 * 4: Three color channels and an alpha channel (RGBA). 2747 * 2748 * The components are encoded in one of two ways: 2749 * 2750 * a) As a small integer, value 0..255, contained in a single byte. For the 2751 * alpha channel the original value is simply value/255. For the color or 2752 * luminance channels the value is encoded according to the sRGB specification 2753 * and matches the 8-bit format expected by typical display devices. 2754 * 2755 * The color/gray channels are not scaled (pre-multiplied) by the alpha 2756 * channel and are suitable for passing to color management software. 2757 * 2758 * b) As a value in the range 0..65535, contained in a 2-byte integer. All 2759 * channels can be converted to the original value by dividing by 65535; all 2760 * channels are linear. Color channels use the RGB encoding (RGB end-points) of 2761 * the sRGB specification. This encoding is identified by the 2762 * PNG_FORMAT_FLAG_LINEAR flag below. 2763 * 2764 * When the simplified API needs to convert between sRGB and linear colorspaces, 2765 * the actual sRGB transfer curve defined in the sRGB specification (see the 2766 * article at <https://en.wikipedia.org/wiki/SRGB>) is used, not the gamma=1/2.2 2767 * approximation used elsewhere in libpng. 2768 * 2769 * When an alpha channel is present it is expected to denote pixel coverage 2770 * of the color or luminance channels and is returned as an associated alpha 2771 * channel: the color/gray channels are scaled (pre-multiplied) by the alpha 2772 * value. 2773 * 2774 * The samples are either contained directly in the image data, between 1 and 8 2775 * bytes per pixel according to the encoding, or are held in a color-map indexed 2776 * by bytes in the image data. In the case of a color-map the color-map entries 2777 * are individual samples, encoded as above, and the image data has one byte per 2778 * pixel to select the relevant sample from the color-map. 2779 */ 2780 2781 /* PNG_FORMAT_* 2782 * 2783 * #defines to be used in png_image::format. Each #define identifies a 2784 * particular layout of sample data and, if present, alpha values. There are 2785 * separate defines for each of the two component encodings. 2786 * 2787 * A format is built up using single bit flag values. All combinations are 2788 * valid. Formats can be built up from the flag values or you can use one of 2789 * the predefined values below. When testing formats always use the FORMAT_FLAG 2790 * macros to test for individual features - future versions of the library may 2791 * add new flags. 2792 * 2793 * When reading or writing color-mapped images the format should be set to the 2794 * format of the entries in the color-map then png_image_{read,write}_colormap 2795 * called to read or write the color-map and set the format correctly for the 2796 * image data. Do not set the PNG_FORMAT_FLAG_COLORMAP bit directly! 2797 * 2798 * NOTE: libpng can be built with particular features disabled. If you see 2799 * compiler errors because the definition of one of the following flags has been 2800 * compiled out it is because libpng does not have the required support. It is 2801 * possible, however, for the libpng configuration to enable the format on just 2802 * read or just write; in that case you may see an error at run time. You can 2803 * guard against this by checking for the definition of the appropriate 2804 * "_SUPPORTED" macro, one of: 2805 * 2806 * PNG_SIMPLIFIED_{READ,WRITE}_{BGR,AFIRST}_SUPPORTED 2807 */ 2808 #define PNG_FORMAT_FLAG_ALPHA 0x01U /* format with an alpha channel */ 2809 #define PNG_FORMAT_FLAG_COLOR 0x02U /* color format: otherwise grayscale */ 2810 #define PNG_FORMAT_FLAG_LINEAR 0x04U /* 2-byte channels else 1-byte */ 2811 #define PNG_FORMAT_FLAG_COLORMAP 0x08U /* image data is color-mapped */ 2812 2813 #ifdef PNG_FORMAT_BGR_SUPPORTED 2814 # define PNG_FORMAT_FLAG_BGR 0x10U /* BGR colors, else order is RGB */ 2815 #endif 2816 2817 #ifdef PNG_FORMAT_AFIRST_SUPPORTED 2818 # define PNG_FORMAT_FLAG_AFIRST 0x20U /* alpha channel comes first */ 2819 #endif 2820 2821 #define PNG_FORMAT_FLAG_ASSOCIATED_ALPHA 0x40U /* alpha channel is associated */ 2822 2823 /* Commonly used formats have predefined macros. 2824 * 2825 * First the single byte (sRGB) formats: 2826 */ 2827 #define PNG_FORMAT_GRAY 0 2828 #define PNG_FORMAT_GA PNG_FORMAT_FLAG_ALPHA 2829 #define PNG_FORMAT_AG (PNG_FORMAT_GA|PNG_FORMAT_FLAG_AFIRST) 2830 #define PNG_FORMAT_RGB PNG_FORMAT_FLAG_COLOR 2831 #define PNG_FORMAT_BGR (PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_BGR) 2832 #define PNG_FORMAT_RGBA (PNG_FORMAT_RGB|PNG_FORMAT_FLAG_ALPHA) 2833 #define PNG_FORMAT_ARGB (PNG_FORMAT_RGBA|PNG_FORMAT_FLAG_AFIRST) 2834 #define PNG_FORMAT_BGRA (PNG_FORMAT_BGR|PNG_FORMAT_FLAG_ALPHA) 2835 #define PNG_FORMAT_ABGR (PNG_FORMAT_BGRA|PNG_FORMAT_FLAG_AFIRST) 2836 2837 /* Then the linear 2-byte formats. When naming these "Y" is used to 2838 * indicate a luminance (gray) channel. 2839 */ 2840 #define PNG_FORMAT_LINEAR_Y PNG_FORMAT_FLAG_LINEAR 2841 #define PNG_FORMAT_LINEAR_Y_ALPHA (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_ALPHA) 2842 #define PNG_FORMAT_LINEAR_RGB (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR) 2843 #define PNG_FORMAT_LINEAR_RGB_ALPHA \ 2844 (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_ALPHA) 2845 2846 /* With color-mapped formats the image data is one byte for each pixel, the byte 2847 * is an index into the color-map which is formatted as above. To obtain a 2848 * color-mapped format it is sufficient just to add the PNG_FOMAT_FLAG_COLORMAP 2849 * to one of the above definitions, or you can use one of the definitions below. 2850 */ 2851 #define PNG_FORMAT_RGB_COLORMAP (PNG_FORMAT_RGB|PNG_FORMAT_FLAG_COLORMAP) 2852 #define PNG_FORMAT_BGR_COLORMAP (PNG_FORMAT_BGR|PNG_FORMAT_FLAG_COLORMAP) 2853 #define PNG_FORMAT_RGBA_COLORMAP (PNG_FORMAT_RGBA|PNG_FORMAT_FLAG_COLORMAP) 2854 #define PNG_FORMAT_ARGB_COLORMAP (PNG_FORMAT_ARGB|PNG_FORMAT_FLAG_COLORMAP) 2855 #define PNG_FORMAT_BGRA_COLORMAP (PNG_FORMAT_BGRA|PNG_FORMAT_FLAG_COLORMAP) 2856 #define PNG_FORMAT_ABGR_COLORMAP (PNG_FORMAT_ABGR|PNG_FORMAT_FLAG_COLORMAP) 2857 2858 /* PNG_IMAGE macros 2859 * 2860 * These are convenience macros to derive information from a png_image 2861 * structure. The PNG_IMAGE_SAMPLE_ macros return values appropriate to the 2862 * actual image sample values - either the entries in the color-map or the 2863 * pixels in the image. The PNG_IMAGE_PIXEL_ macros return corresponding values 2864 * for the pixels and will always return 1 for color-mapped formats. The 2865 * remaining macros return information about the rows in the image and the 2866 * complete image. 2867 * 2868 * NOTE: All the macros that take a png_image::format parameter are compile time 2869 * constants if the format parameter is, itself, a constant. Therefore these 2870 * macros can be used in array declarations and case labels where required. 2871 * Similarly the macros are also pre-processor constants (sizeof is not used) so 2872 * they can be used in #if tests. 2873 * 2874 * First the information about the samples. 2875 */ 2876 #define PNG_IMAGE_SAMPLE_CHANNELS(fmt)\ 2877 (((fmt)&(PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_ALPHA))+1) 2878 /* Return the total number of channels in a given format: 1..4 */ 2879 2880 #define PNG_IMAGE_SAMPLE_COMPONENT_SIZE(fmt)\ 2881 ((((fmt) & PNG_FORMAT_FLAG_LINEAR) >> 2)+1) 2882 /* Return the size in bytes of a single component of a pixel or color-map 2883 * entry (as appropriate) in the image: 1 or 2. 2884 */ 2885 2886 #define PNG_IMAGE_SAMPLE_SIZE(fmt)\ 2887 (PNG_IMAGE_SAMPLE_CHANNELS(fmt) * PNG_IMAGE_SAMPLE_COMPONENT_SIZE(fmt)) 2888 /* This is the size of the sample data for one sample. If the image is 2889 * color-mapped it is the size of one color-map entry (and image pixels are 2890 * one byte in size), otherwise it is the size of one image pixel. 2891 */ 2892 2893 #define PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(fmt)\ 2894 (PNG_IMAGE_SAMPLE_CHANNELS(fmt) * 256) 2895 /* The maximum size of the color-map required by the format expressed in a 2896 * count of components. This can be used to compile-time allocate a 2897 * color-map: 2898 * 2899 * png_uint_16 colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(linear_fmt)]; 2900 * 2901 * png_byte colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(sRGB_fmt)]; 2902 * 2903 * Alternatively use the PNG_IMAGE_COLORMAP_SIZE macro below to use the 2904 * information from one of the png_image_begin_read_ APIs and dynamically 2905 * allocate the required memory. 2906 */ 2907 2908 /* Corresponding information about the pixels */ 2909 #define PNG_IMAGE_PIXEL_(test,fmt)\ 2910 (((fmt)&PNG_FORMAT_FLAG_COLORMAP)?1:test(fmt)) 2911 2912 #define PNG_IMAGE_PIXEL_CHANNELS(fmt)\ 2913 PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_CHANNELS,fmt) 2914 /* The number of separate channels (components) in a pixel; 1 for a 2915 * color-mapped image. 2916 */ 2917 2918 #define PNG_IMAGE_PIXEL_COMPONENT_SIZE(fmt)\ 2919 PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_COMPONENT_SIZE,fmt) 2920 /* The size, in bytes, of each component in a pixel; 1 for a color-mapped 2921 * image. 2922 */ 2923 2924 #define PNG_IMAGE_PIXEL_SIZE(fmt) PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_SIZE,fmt) 2925 /* The size, in bytes, of a complete pixel; 1 for a color-mapped image. */ 2926 2927 /* Information about the whole row, or whole image */ 2928 #define PNG_IMAGE_ROW_STRIDE(image)\ 2929 (PNG_IMAGE_PIXEL_CHANNELS((image).format) * (image).width) 2930 /* Return the total number of components in a single row of the image; this 2931 * is the minimum 'row stride', the minimum count of components between each 2932 * row. For a color-mapped image this is the minimum number of bytes in a 2933 * row. 2934 * 2935 * WARNING: this macro overflows for some images with more than one component 2936 * and very large image widths. libpng will refuse to process an image where 2937 * this macro would overflow. 2938 */ 2939 2940 #define PNG_IMAGE_BUFFER_SIZE(image, row_stride)\ 2941 (PNG_IMAGE_PIXEL_COMPONENT_SIZE((image).format)*(image).height*(row_stride)) 2942 /* Return the size, in bytes, of an image buffer given a png_image and a row 2943 * stride - the number of components to leave space for in each row. 2944 * 2945 * WARNING: this macro overflows a 32-bit integer for some large PNG images, 2946 * libpng will refuse to process an image where such an overflow would occur. 2947 */ 2948 2949 #define PNG_IMAGE_SIZE(image)\ 2950 PNG_IMAGE_BUFFER_SIZE(image, PNG_IMAGE_ROW_STRIDE(image)) 2951 /* Return the size, in bytes, of the image in memory given just a png_image; 2952 * the row stride is the minimum stride required for the image. 2953 */ 2954 2955 #define PNG_IMAGE_COLORMAP_SIZE(image)\ 2956 (PNG_IMAGE_SAMPLE_SIZE((image).format) * (image).colormap_entries) 2957 /* Return the size, in bytes, of the color-map of this image. If the image 2958 * format is not a color-map format this will return a size sufficient for 2959 * 256 entries in the given format; check PNG_FORMAT_FLAG_COLORMAP if 2960 * you don't want to allocate a color-map in this case. 2961 */ 2962 2963 /* PNG_IMAGE_FLAG_* 2964 * 2965 * Flags containing additional information about the image are held in the 2966 * 'flags' field of png_image. 2967 */ 2968 #define PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB 0x01 2969 /* This indicates that the RGB values of the in-memory bitmap do not 2970 * correspond to the red, green and blue end-points defined by sRGB. 2971 */ 2972 2973 #define PNG_IMAGE_FLAG_FAST 0x02 2974 /* On write emphasise speed over compression; the resultant PNG file will be 2975 * larger but will be produced significantly faster, particular for large 2976 * images. Do not use this option for images which will be distributed, only 2977 * used it when producing intermediate files that will be read back in 2978 * repeatedly. For a typical 24-bit image the option will double the read 2979 * speed at the cost of increasing the image size by 25%, however for many 2980 * more compressible images the PNG file can be 10 times larger with only a 2981 * slight speed gain. 2982 */ 2983 2984 #define PNG_IMAGE_FLAG_16BIT_sRGB 0x04 2985 /* On read if the image is a 16-bit per component image and there is no gAMA 2986 * or sRGB chunk assume that the components are sRGB encoded. Notice that 2987 * images output by the simplified API always have gamma information; setting 2988 * this flag only affects the interpretation of 16-bit images from an 2989 * external source. It is recommended that the application expose this flag 2990 * to the user; the user can normally easily recognize the difference between 2991 * linear and sRGB encoding. This flag has no effect on write - the data 2992 * passed to the write APIs must have the correct encoding (as defined 2993 * above.) 2994 * 2995 * If the flag is not set (the default) input 16-bit per component data is 2996 * assumed to be linear. 2997 * 2998 * NOTE: the flag can only be set after the png_image_begin_read_ call, 2999 * because that call initializes the 'flags' field. 3000 */ 3001 3002 #ifdef PNG_SIMPLIFIED_READ_SUPPORTED 3003 /* READ APIs 3004 * --------- 3005 * 3006 * The png_image passed to the read APIs must have been initialized by setting 3007 * the png_controlp field 'opaque' to NULL (or, safer, memset the whole thing.) 3008 */ 3009 #ifdef PNG_STDIO_SUPPORTED 3010 PNG_EXPORT(234, int, png_image_begin_read_from_file, (png_imagep image, 3011 const char *file_name)); 3012 /* The named file is opened for read and the image header is filled in 3013 * from the PNG header in the file. 3014 */ 3015 3016 PNG_EXPORT(235, int, png_image_begin_read_from_stdio, (png_imagep image, 3017 FILE* file)); 3018 /* The PNG header is read from the stdio FILE object. */ 3019 #endif /* STDIO */ 3020 3021 PNG_EXPORT(236, int, png_image_begin_read_from_memory, (png_imagep image, 3022 png_const_voidp memory, size_t size)); 3023 /* The PNG header is read from the given memory buffer. */ 3024 3025 PNG_EXPORT(237, int, png_image_finish_read, (png_imagep image, 3026 png_const_colorp background, void *buffer, png_int_32 row_stride, 3027 void *colormap)); 3028 /* Finish reading the image into the supplied buffer and clean up the 3029 * png_image structure. 3030 * 3031 * row_stride is the step, in byte or 2-byte units as appropriate, 3032 * between adjacent rows. A positive stride indicates that the top-most row 3033 * is first in the buffer - the normal top-down arrangement. A negative 3034 * stride indicates that the bottom-most row is first in the buffer. 3035 * 3036 * background need only be supplied if an alpha channel must be removed from 3037 * a png_byte format and the removal is to be done by compositing on a solid 3038 * color; otherwise it may be NULL and any composition will be done directly 3039 * onto the buffer. The value is an sRGB color to use for the background, 3040 * for grayscale output the green channel is used. 3041 * 3042 * background must be supplied when an alpha channel must be removed from a 3043 * single byte color-mapped output format, in other words if: 3044 * 3045 * 1) The original format from png_image_begin_read_from_* had 3046 * PNG_FORMAT_FLAG_ALPHA set. 3047 * 2) The format set by the application does not. 3048 * 3) The format set by the application has PNG_FORMAT_FLAG_COLORMAP set and 3049 * PNG_FORMAT_FLAG_LINEAR *not* set. 3050 * 3051 * For linear output removing the alpha channel is always done by compositing 3052 * on black and background is ignored. 3053 * 3054 * colormap must be supplied when PNG_FORMAT_FLAG_COLORMAP is set. It must 3055 * be at least the size (in bytes) returned by PNG_IMAGE_COLORMAP_SIZE. 3056 * image->colormap_entries will be updated to the actual number of entries 3057 * written to the colormap; this may be less than the original value. 3058 */ 3059 3060 PNG_EXPORT(238, void, png_image_free, (png_imagep image)); 3061 /* Free any data allocated by libpng in image->opaque, setting the pointer to 3062 * NULL. May be called at any time after the structure is initialized. 3063 */ 3064 #endif /* SIMPLIFIED_READ */ 3065 3066 #ifdef PNG_SIMPLIFIED_WRITE_SUPPORTED 3067 /* WRITE APIS 3068 * ---------- 3069 * For write you must initialize a png_image structure to describe the image to 3070 * be written. To do this use memset to set the whole structure to 0 then 3071 * initialize fields describing your image. 3072 * 3073 * version: must be set to PNG_IMAGE_VERSION 3074 * opaque: must be initialized to NULL 3075 * width: image width in pixels 3076 * height: image height in rows 3077 * format: the format of the data (image and color-map) you wish to write 3078 * flags: set to 0 unless one of the defined flags applies; set 3079 * PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB for color format images where the RGB 3080 * values do not correspond to the colors in sRGB. 3081 * colormap_entries: set to the number of entries in the color-map (0 to 256) 3082 */ 3083 #ifdef PNG_SIMPLIFIED_WRITE_STDIO_SUPPORTED 3084 PNG_EXPORT(239, int, png_image_write_to_file, (png_imagep image, 3085 const char *file, int convert_to_8bit, const void *buffer, 3086 png_int_32 row_stride, const void *colormap)); 3087 /* Write the image to the named file. */ 3088 3089 PNG_EXPORT(240, int, png_image_write_to_stdio, (png_imagep image, FILE *file, 3090 int convert_to_8_bit, const void *buffer, png_int_32 row_stride, 3091 const void *colormap)); 3092 /* Write the image to the given (FILE*). */ 3093 #endif /* SIMPLIFIED_WRITE_STDIO */ 3094 3095 /* With all write APIs if image is in one of the linear formats with 16-bit 3096 * data then setting convert_to_8_bit will cause the output to be an 8-bit PNG 3097 * gamma encoded according to the sRGB specification, otherwise a 16-bit linear 3098 * encoded PNG file is written. 3099 * 3100 * With color-mapped data formats the colormap parameter point to a color-map 3101 * with at least image->colormap_entries encoded in the specified format. If 3102 * the format is linear the written PNG color-map will be converted to sRGB 3103 * regardless of the convert_to_8_bit flag. 3104 * 3105 * With all APIs row_stride is handled as in the read APIs - it is the spacing 3106 * from one row to the next in component sized units (1 or 2 bytes) and if 3107 * negative indicates a bottom-up row layout in the buffer. If row_stride is 3108 * zero, libpng will calculate it for you from the image width and number of 3109 * channels. 3110 * 3111 * Note that the write API does not support interlacing, sub-8-bit pixels or 3112 * most ancillary chunks. If you need to write text chunks (e.g. for copyright 3113 * notices) you need to use one of the other APIs. 3114 */ 3115 3116 PNG_EXPORT(245, int, png_image_write_to_memory, (png_imagep image, void *memory, 3117 png_alloc_size_t * PNG_RESTRICT memory_bytes, int convert_to_8_bit, 3118 const void *buffer, png_int_32 row_stride, const void *colormap)); 3119 /* Write the image to the given memory buffer. The function both writes the 3120 * whole PNG data stream to *memory and updates *memory_bytes with the count 3121 * of bytes written. 3122 * 3123 * 'memory' may be NULL. In this case *memory_bytes is not read however on 3124 * success the number of bytes which would have been written will still be 3125 * stored in *memory_bytes. On failure *memory_bytes will contain 0. 3126 * 3127 * If 'memory' is not NULL it must point to memory[*memory_bytes] of 3128 * writeable memory. 3129 * 3130 * If the function returns success memory[*memory_bytes] (if 'memory' is not 3131 * NULL) contains the written PNG data. *memory_bytes will always be less 3132 * than or equal to the original value. 3133 * 3134 * If the function returns false and *memory_bytes was not changed an error 3135 * occurred during write. If *memory_bytes was changed, or is not 0 if 3136 * 'memory' was NULL, the write would have succeeded but for the memory 3137 * buffer being too small. *memory_bytes contains the required number of 3138 * bytes and will be bigger that the original value. 3139 */ 3140 3141 #define png_image_write_get_memory_size(image, size, convert_to_8_bit, buffer,\ 3142 row_stride, colormap)\ 3143 png_image_write_to_memory(&(image), 0, &(size), convert_to_8_bit, buffer,\ 3144 row_stride, colormap) 3145 /* Return the amount of memory in 'size' required to compress this image. 3146 * The png_image structure 'image' must be filled in as in the above 3147 * function and must not be changed before the actual write call, the buffer 3148 * and all other parameters must also be identical to that in the final 3149 * write call. The 'size' variable need not be initialized. 3150 * 3151 * NOTE: the macro returns true/false, if false is returned 'size' will be 3152 * set to zero and the write failed and probably will fail if tried again. 3153 */ 3154 3155 /* You can pre-allocate the buffer by making sure it is of sufficient size 3156 * regardless of the amount of compression achieved. The buffer size will 3157 * always be bigger than the original image and it will never be filled. The 3158 * following macros are provided to assist in allocating the buffer. 3159 */ 3160 #define PNG_IMAGE_DATA_SIZE(image) (PNG_IMAGE_SIZE(image)+(image).height) 3161 /* The number of uncompressed bytes in the PNG byte encoding of the image; 3162 * uncompressing the PNG IDAT data will give this number of bytes. 3163 * 3164 * NOTE: while PNG_IMAGE_SIZE cannot overflow for an image in memory this 3165 * macro can because of the extra bytes used in the PNG byte encoding. You 3166 * need to avoid this macro if your image size approaches 2^30 in width or 3167 * height. The same goes for the remainder of these macros; they all produce 3168 * bigger numbers than the actual in-memory image size. 3169 */ 3170 #ifndef PNG_ZLIB_MAX_SIZE 3171 # define PNG_ZLIB_MAX_SIZE(b) ((b)+(((b)+7U)>>3)+(((b)+63U)>>6)+11U) 3172 /* An upper bound on the number of compressed bytes given 'b' uncompressed 3173 * bytes. This is based on deflateBounds() in zlib; different 3174 * implementations of zlib compression may conceivably produce more data so 3175 * if your zlib implementation is not zlib itself redefine this macro 3176 * appropriately. 3177 */ 3178 #endif 3179 3180 #define PNG_IMAGE_COMPRESSED_SIZE_MAX(image)\ 3181 PNG_ZLIB_MAX_SIZE((png_alloc_size_t)PNG_IMAGE_DATA_SIZE(image)) 3182 /* An upper bound on the size of the data in the PNG IDAT chunks. */ 3183 3184 #define PNG_IMAGE_PNG_SIZE_MAX_(image, image_size)\ 3185 ((8U/*sig*/+25U/*IHDR*/+16U/*gAMA*/+44U/*cHRM*/+12U/*IEND*/+\ 3186 (((image).format&PNG_FORMAT_FLAG_COLORMAP)?/*colormap: PLTE, tRNS*/\ 3187 12U+3U*(image).colormap_entries/*PLTE data*/+\ 3188 (((image).format&PNG_FORMAT_FLAG_ALPHA)?\ 3189 12U/*tRNS*/+(image).colormap_entries:0U):0U)+\ 3190 12U)+(12U*((image_size)/PNG_ZBUF_SIZE))/*IDAT*/+(image_size)) 3191 /* A helper for the following macro; if your compiler cannot handle the 3192 * following macro use this one with the result of 3193 * PNG_IMAGE_COMPRESSED_SIZE_MAX(image) as the second argument (most 3194 * compilers should handle this just fine.) 3195 */ 3196 3197 #define PNG_IMAGE_PNG_SIZE_MAX(image)\ 3198 PNG_IMAGE_PNG_SIZE_MAX_(image, PNG_IMAGE_COMPRESSED_SIZE_MAX(image)) 3199 /* An upper bound on the total length of the PNG data stream for 'image'. 3200 * The result is of type png_alloc_size_t, on 32-bit systems this may 3201 * overflow even though PNG_IMAGE_DATA_SIZE does not overflow; the write will 3202 * run out of buffer space but return a corrected size which should work. 3203 */ 3204 #endif /* SIMPLIFIED_WRITE */ 3205 /******************************************************************************* 3206 * END OF SIMPLIFIED API 3207 ******************************************************************************/ 3208 #endif /* SIMPLIFIED_{READ|WRITE} */ 3209 3210 /******************************************************************************* 3211 * Section 6: IMPLEMENTATION OPTIONS 3212 ******************************************************************************* 3213 * 3214 * Support for arbitrary implementation-specific optimizations. The API allows 3215 * particular options to be turned on or off. 'Option' is the number of the 3216 * option and 'onoff' is 0 (off) or non-0 (on). The value returned is given 3217 * by the PNG_OPTION_ defines below. 3218 * 3219 * HARDWARE: normally hardware capabilities, such as the Intel SSE instructions, 3220 * are detected at run time, however sometimes it may be impossible 3221 * to do this in user mode, in which case it is necessary to discover 3222 * the capabilities in an OS specific way. Such capabilities are 3223 * listed here when libpng has support for them and must be turned 3224 * ON by the application if present. 3225 * 3226 * SOFTWARE: sometimes software optimizations actually result in performance 3227 * decrease on some architectures or systems, or with some sets of 3228 * PNG images. 'Software' options allow such optimizations to be 3229 * selected at run time. 3230 */ 3231 #ifdef PNG_SET_OPTION_SUPPORTED 3232 #ifdef PNG_ARM_NEON_API_SUPPORTED 3233 # define PNG_ARM_NEON 0 /* HARDWARE: ARM Neon SIMD instructions supported */ 3234 #endif 3235 #define PNG_MAXIMUM_INFLATE_WINDOW 2 /* SOFTWARE: force maximum window */ 3236 #define PNG_SKIP_sRGB_CHECK_PROFILE 4 /* SOFTWARE: Check ICC profile for sRGB */ 3237 #ifdef PNG_MIPS_MSA_API_SUPPORTED 3238 # define PNG_MIPS_MSA 6 /* HARDWARE: MIPS Msa SIMD instructions supported */ 3239 #endif 3240 #define PNG_IGNORE_ADLER32 8 3241 #ifdef PNG_POWERPC_VSX_API_SUPPORTED 3242 # define PNG_POWERPC_VSX 10 /* HARDWARE: PowerPC VSX SIMD instructions supported */ 3243 #endif 3244 #define PNG_OPTION_NEXT 12 /* Next option - numbers must be even */ 3245 3246 /* Return values: NOTE: there are four values and 'off' is *not* zero */ 3247 #define PNG_OPTION_UNSET 0 /* Unset - defaults to off */ 3248 #define PNG_OPTION_INVALID 1 /* Option number out of range */ 3249 #define PNG_OPTION_OFF 2 3250 #define PNG_OPTION_ON 3 3251 3252 PNG_EXPORT(244, int, png_set_option, (png_structrp png_ptr, int option, 3253 int onoff)); 3254 #endif /* SET_OPTION */ 3255 3256 /******************************************************************************* 3257 * END OF HARDWARE AND SOFTWARE OPTIONS 3258 ******************************************************************************/ 3259 3260 #ifdef PNG_APNG_SUPPORTED 3261 PNG_EXPORT(248, png_uint_32, png_get_acTL, (png_structp png_ptr, 3262 png_infop info_ptr, png_uint_32 *num_frames, png_uint_32 *num_plays)); 3263 3264 PNG_EXPORT(249, png_uint_32, png_set_acTL, (png_structp png_ptr, 3265 png_infop info_ptr, png_uint_32 num_frames, png_uint_32 num_plays)); 3266 3267 PNG_EXPORT(250, png_uint_32, png_get_num_frames, (png_structp png_ptr, 3268 png_infop info_ptr)); 3269 3270 PNG_EXPORT(251, png_uint_32, png_get_num_plays, (png_structp png_ptr, 3271 png_infop info_ptr)); 3272 3273 PNG_EXPORT(252, png_uint_32, png_get_next_frame_fcTL, 3274 (png_structp png_ptr, png_infop info_ptr, png_uint_32 *width, 3275 png_uint_32 *height, png_uint_32 *x_offset, png_uint_32 *y_offset, 3276 png_uint_16 *delay_num, png_uint_16 *delay_den, png_byte *dispose_op, 3277 png_byte *blend_op)); 3278 3279 PNG_EXPORT(253, png_uint_32, png_set_next_frame_fcTL, 3280 (png_structp png_ptr, png_infop info_ptr, png_uint_32 width, 3281 png_uint_32 height, png_uint_32 x_offset, png_uint_32 y_offset, 3282 png_uint_16 delay_num, png_uint_16 delay_den, png_byte dispose_op, 3283 png_byte blend_op)); 3284 3285 PNG_EXPORT(254, png_uint_32, png_get_next_frame_width, 3286 (png_structp png_ptr, png_infop info_ptr)); 3287 PNG_EXPORT(255, png_uint_32, png_get_next_frame_height, 3288 (png_structp png_ptr, png_infop info_ptr)); 3289 PNG_EXPORT(256, png_uint_32, png_get_next_frame_x_offset, 3290 (png_structp png_ptr, png_infop info_ptr)); 3291 PNG_EXPORT(257, png_uint_32, png_get_next_frame_y_offset, 3292 (png_structp png_ptr, png_infop info_ptr)); 3293 PNG_EXPORT(258, png_uint_16, png_get_next_frame_delay_num, 3294 (png_structp png_ptr, png_infop info_ptr)); 3295 PNG_EXPORT(259, png_uint_16, png_get_next_frame_delay_den, 3296 (png_structp png_ptr, png_infop info_ptr)); 3297 PNG_EXPORT(260, png_byte, png_get_next_frame_dispose_op, 3298 (png_structp png_ptr, png_infop info_ptr)); 3299 PNG_EXPORT(261, png_byte, png_get_next_frame_blend_op, 3300 (png_structp png_ptr, png_infop info_ptr)); 3301 PNG_EXPORT(262, png_byte, png_get_first_frame_is_hidden, 3302 (png_structp png_ptr, png_infop info_ptr)); 3303 PNG_EXPORT(263, png_uint_32, png_set_first_frame_is_hidden, 3304 (png_structp png_ptr, png_infop info_ptr, png_byte is_hidden)); 3305 3306 #ifdef PNG_READ_APNG_SUPPORTED 3307 PNG_EXPORT(264, void, png_read_frame_head, (png_structp png_ptr, 3308 png_infop info_ptr)); 3309 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED 3310 PNG_EXPORT(265, void, png_set_progressive_frame_fn, (png_structp png_ptr, 3311 png_progressive_frame_ptr frame_info_fn, 3312 png_progressive_frame_ptr frame_end_fn)); 3313 #endif /* PROGRESSIVE_READ */ 3314 #endif /* READ_APNG */ 3315 3316 #ifdef PNG_WRITE_APNG_SUPPORTED 3317 PNG_EXPORT(266, void, png_write_frame_head, (png_structp png_ptr, 3318 png_infop info_ptr, png_bytepp row_pointers, 3319 png_uint_32 width, png_uint_32 height, 3320 png_uint_32 x_offset, png_uint_32 y_offset, 3321 png_uint_16 delay_num, png_uint_16 delay_den, png_byte dispose_op, 3322 png_byte blend_op)); 3323 3324 PNG_EXPORT(267, void, png_write_frame_tail, (png_structp png_ptr, 3325 png_infop info_ptr)); 3326 #endif /* WRITE_APNG */ 3327 #endif /* APNG */ 3328 3329 /* Maintainer: Put new public prototypes here ^, in libpng.3, in project 3330 * defs, and in scripts/symbols.def. 3331 */ 3332 3333 /* The last ordinal number (this is the *last* one already used; the next 3334 * one to use is one more than this.) 3335 */ 3336 #ifdef PNG_EXPORT_LAST_ORDINAL 3337 #ifdef PNG_APNG_SUPPORTED 3338 PNG_EXPORT_LAST_ORDINAL(269); 3339 #else 3340 PNG_EXPORT_LAST_ORDINAL(249); 3341 #endif /* APNG */ 3342 #endif 3343 3344 #ifdef __cplusplus 3345 } 3346 #endif 3347 3348 #endif /* PNG_VERSION_INFO_ONLY */ 3349 /* Do not put anything past this line */ 3350 #endif /* PNG_H */ 3351