1 /* 2 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 3 * 4 * This code is free software; you can redistribute it and/or modify it 5 * under the terms of the GNU General Public License version 2 only, as 6 * published by the Free Software Foundation. Oracle designates this 7 * particular file as subject to the "Classpath" exception as provided 8 * by Oracle in the LICENSE file that accompanied this code. 9 * 10 * This code is distributed in the hope that it will be useful, but WITHOUT 11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 13 * version 2 for more details (a copy is included in the LICENSE file that 14 * accompanied this code). 15 * 16 * You should have received a copy of the GNU General Public License version 17 * 2 along with this work; if not, write to the Free Software Foundation, 18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 19 * 20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 21 * or visit www.oracle.com if you need additional information or have any 22 * questions. 23 */ 24 25 /* png.h - header file for PNG reference library 26 * 27 * This file is available under and governed by the GNU General Public 28 * License version 2 only, as published by the Free Software Foundation. 29 * However, the following notice accompanied the original version of this 30 * file and, per its terms, should not be removed: 31 * 32 * libpng version 1.6.37 - April 14, 2019 33 * 34 * Copyright (c) 2018-2019 Cosmin Truta 35 * Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson 36 * Copyright (c) 1996-1997 Andreas Dilger 37 * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc. 38 * 39 * This code is released under the libpng license. (See LICENSE, below.) 40 * 41 * Authors and maintainers: 42 * libpng versions 0.71, May 1995, through 0.88, January 1996: Guy Schalnat 43 * libpng versions 0.89, June 1996, through 0.96, May 1997: Andreas Dilger 44 * libpng versions 0.97, January 1998, through 1.6.35, July 2018: 45 * Glenn Randers-Pehrson 46 * libpng versions 1.6.36, December 2018, through 1.6.37, April 2019: 47 * Cosmin Truta 48 * See also "Contributing Authors", below. 49 */ 50 51 /* 52 * COPYRIGHT NOTICE, DISCLAIMER, and LICENSE 53 * ========================================= 54 * 55 * PNG Reference Library License version 2 56 * --------------------------------------- 57 * 58 * * Copyright (c) 1995-2019 The PNG Reference Library Authors. 59 * * Copyright (c) 2018-2019 Cosmin Truta. 60 * * Copyright (c) 2000-2002, 2004, 2006-2018 Glenn Randers-Pehrson. 61 * * Copyright (c) 1996-1997 Andreas Dilger. 62 * * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc. 63 * 64 * The software is supplied "as is", without warranty of any kind, 65 * express or implied, including, without limitation, the warranties 66 * of merchantability, fitness for a particular purpose, title, and 67 * non-infringement. In no event shall the Copyright owners, or 68 * anyone distributing the software, be liable for any damages or 69 * other liability, whether in contract, tort or otherwise, arising 70 * from, out of, or in connection with the software, or the use or 71 * other dealings in the software, even if advised of the possibility 72 * of such damage. 73 * 74 * Permission is hereby granted to use, copy, modify, and distribute 75 * this software, or portions hereof, for any purpose, without fee, 76 * subject to the following restrictions: 77 * 78 * 1. The origin of this software must not be misrepresented; you 79 * must not claim that you wrote the original software. If you 80 * use this software in a product, an acknowledgment in the product 81 * documentation would be appreciated, but is not required. 82 * 83 * 2. Altered source versions must be plainly marked as such, and must 84 * not be misrepresented as being the original software. 85 * 86 * 3. This Copyright notice may not be removed or altered from any 87 * source or altered source distribution. 88 * 89 * 90 * PNG Reference Library License version 1 (for libpng 0.5 through 1.6.35) 91 * ----------------------------------------------------------------------- 92 * 93 * libpng versions 1.0.7, July 1, 2000, through 1.6.35, July 15, 2018 are 94 * Copyright (c) 2000-2002, 2004, 2006-2018 Glenn Randers-Pehrson, are 95 * derived from libpng-1.0.6, and are distributed according to the same 96 * disclaimer and license as libpng-1.0.6 with the following individuals 97 * added to the list of Contributing Authors: 98 * 99 * Simon-Pierre Cadieux 100 * Eric S. Raymond 101 * Mans Rullgard 102 * Cosmin Truta 103 * Gilles Vollant 104 * James Yu 105 * Mandar Sahastrabuddhe 106 * Google Inc. 107 * Vadim Barkov 108 * 109 * and with the following additions to the disclaimer: 110 * 111 * There is no warranty against interference with your enjoyment of 112 * the library or against infringement. There is no warranty that our 113 * efforts or the library will fulfill any of your particular purposes 114 * or needs. This library is provided with all faults, and the entire 115 * risk of satisfactory quality, performance, accuracy, and effort is 116 * with the user. 117 * 118 * Some files in the "contrib" directory and some configure-generated 119 * files that are distributed with libpng have other copyright owners, and 120 * are released under other open source licenses. 121 * 122 * libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are 123 * Copyright (c) 1998-2000 Glenn Randers-Pehrson, are derived from 124 * libpng-0.96, and are distributed according to the same disclaimer and 125 * license as libpng-0.96, with the following individuals added to the 126 * list of Contributing Authors: 127 * 128 * Tom Lane 129 * Glenn Randers-Pehrson 130 * Willem van Schaik 131 * 132 * libpng versions 0.89, June 1996, through 0.96, May 1997, are 133 * Copyright (c) 1996-1997 Andreas Dilger, are derived from libpng-0.88, 134 * and are distributed according to the same disclaimer and license as 135 * libpng-0.88, with the following individuals added to the list of 136 * Contributing Authors: 137 * 138 * John Bowler 139 * Kevin Bracey 140 * Sam Bushell 141 * Magnus Holmgren 142 * Greg Roelofs 143 * Tom Tanner 144 * 145 * Some files in the "scripts" directory have other copyright owners, 146 * but are released under this license. 147 * 148 * libpng versions 0.5, May 1995, through 0.88, January 1996, are 149 * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc. 150 * 151 * For the purposes of this copyright and license, "Contributing Authors" 152 * is defined as the following set of individuals: 153 * 154 * Andreas Dilger 155 * Dave Martindale 156 * Guy Eric Schalnat 157 * Paul Schmidt 158 * Tim Wegner 159 * 160 * The PNG Reference Library is supplied "AS IS". The Contributing 161 * Authors and Group 42, Inc. disclaim all warranties, expressed or 162 * implied, including, without limitation, the warranties of 163 * merchantability and of fitness for any purpose. The Contributing 164 * Authors and Group 42, Inc. assume no liability for direct, indirect, 165 * incidental, special, exemplary, or consequential damages, which may 166 * result from the use of the PNG Reference Library, even if advised of 167 * the possibility of such damage. 168 * 169 * Permission is hereby granted to use, copy, modify, and distribute this 170 * source code, or portions hereof, for any purpose, without fee, subject 171 * to the following restrictions: 172 * 173 * 1. The origin of this source code must not be misrepresented. 174 * 175 * 2. Altered versions must be plainly marked as such and must not 176 * be misrepresented as being the original source. 177 * 178 * 3. This Copyright notice may not be removed or altered from any 179 * source or altered source distribution. 180 * 181 * The Contributing Authors and Group 42, Inc. specifically permit, 182 * without fee, and encourage the use of this source code as a component 183 * to supporting the PNG file format in commercial products. If you use 184 * this source code in a product, acknowledgment is not required but would 185 * be appreciated. 186 * 187 * END OF COPYRIGHT NOTICE, DISCLAIMER, and LICENSE. 188 * 189 * TRADEMARK 190 * ========= 191 * 192 * The name "libpng" has not been registered by the Copyright owners 193 * as a trademark in any jurisdiction. However, because libpng has 194 * been distributed and maintained world-wide, continually since 1995, 195 * the Copyright owners claim "common-law trademark protection" in any 196 * jurisdiction where common-law trademark is recognized. 197 */ 198 199 /* 200 * A "png_get_copyright" function is available, for convenient use in "about" 201 * boxes and the like: 202 * 203 * printf("%s", png_get_copyright(NULL)); 204 * 205 * Also, the PNG logo (in PNG format, of course) is supplied in the 206 * files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31). 207 */ 208 209 /* 210 * The contributing authors would like to thank all those who helped 211 * with testing, bug fixes, and patience. This wouldn't have been 212 * possible without all of you. 213 * 214 * Thanks to Frank J. T. Wojcik for helping with the documentation. 215 */ 216 217 /* Note about libpng version numbers: 218 * 219 * Due to various miscommunications, unforeseen code incompatibilities 220 * and occasional factors outside the authors' control, version numbering 221 * on the library has not always been consistent and straightforward. 222 * The following table summarizes matters since version 0.89c, which was 223 * the first widely used release: 224 * 225 * source png.h png.h shared-lib 226 * version string int version 227 * ------- ------ ----- ---------- 228 * 0.89c "1.0 beta 3" 0.89 89 1.0.89 229 * 0.90 "1.0 beta 4" 0.90 90 0.90 [should have been 2.0.90] 230 * 0.95 "1.0 beta 5" 0.95 95 0.95 [should have been 2.0.95] 231 * 0.96 "1.0 beta 6" 0.96 96 0.96 [should have been 2.0.96] 232 * 0.97b "1.00.97 beta 7" 1.00.97 97 1.0.1 [should have been 2.0.97] 233 * 0.97c 0.97 97 2.0.97 234 * 0.98 0.98 98 2.0.98 235 * 0.99 0.99 98 2.0.99 236 * 0.99a-m 0.99 99 2.0.99 237 * 1.00 1.00 100 2.1.0 [100 should be 10000] 238 * 1.0.0 (from here on, the 100 2.1.0 [100 should be 10000] 239 * 1.0.1 png.h string is 10001 2.1.0 240 * 1.0.1a-e identical to the 10002 from here on, the shared library 241 * 1.0.2 source version) 10002 is 2.V where V is the source code 242 * 1.0.2a-b 10003 version, except as noted. 243 * 1.0.3 10003 244 * 1.0.3a-d 10004 245 * 1.0.4 10004 246 * 1.0.4a-f 10005 247 * 1.0.5 (+ 2 patches) 10005 248 * 1.0.5a-d 10006 249 * 1.0.5e-r 10100 (not source compatible) 250 * 1.0.5s-v 10006 (not binary compatible) 251 * 1.0.6 (+ 3 patches) 10006 (still binary incompatible) 252 * 1.0.6d-f 10007 (still binary incompatible) 253 * 1.0.6g 10007 254 * 1.0.6h 10007 10.6h (testing xy.z so-numbering) 255 * 1.0.6i 10007 10.6i 256 * 1.0.6j 10007 2.1.0.6j (incompatible with 1.0.0) 257 * 1.0.7beta11-14 DLLNUM 10007 2.1.0.7beta11-14 (binary compatible) 258 * 1.0.7beta15-18 1 10007 2.1.0.7beta15-18 (binary compatible) 259 * 1.0.7rc1-2 1 10007 2.1.0.7rc1-2 (binary compatible) 260 * 1.0.7 1 10007 (still compatible) 261 * ... 262 * 1.0.69 10 10069 10.so.0.69[.0] 263 * ... 264 * 1.2.59 13 10259 12.so.0.59[.0] 265 * ... 266 * 1.4.20 14 10420 14.so.0.20[.0] 267 * ... 268 * 1.5.30 15 10530 15.so.15.30[.0] 269 * ... 270 * 1.6.37 16 10637 16.so.16.37[.0] 271 * 272 * Henceforth the source version will match the shared-library major and 273 * minor numbers; the shared-library major version number will be used for 274 * changes in backward compatibility, as it is intended. 275 * The PNG_LIBPNG_VER macro, which is not used within libpng but is 276 * available for applications, is an unsigned integer of the form XYYZZ 277 * corresponding to the source version X.Y.Z (leading zeros in Y and Z). 278 * Beta versions were given the previous public release number plus a 279 * letter, until version 1.0.6j; from then on they were given the upcoming 280 * public release number plus "betaNN" or "rcNN". 281 * 282 * Binary incompatibility exists only when applications make direct access 283 * to the info_ptr or png_ptr members through png.h, and the compiled 284 * application is loaded with a different version of the library. 285 * 286 * DLLNUM will change each time there are forward or backward changes 287 * in binary compatibility (e.g., when a new feature is added). 288 * 289 * See libpng.txt or libpng.3 for more information. The PNG specification 290 * is available as a W3C Recommendation and as an ISO/IEC Standard; see 291 * <https://www.w3.org/TR/2003/REC-PNG-20031110/> 292 */ 293 294 #ifndef PNG_H 295 #define PNG_H 296 297 /* This is not the place to learn how to use libpng. The file libpng-manual.txt 298 * describes how to use libpng, and the file example.c summarizes it 299 * with some code on which to build. This file is useful for looking 300 * at the actual function definitions and structure components. If that 301 * file has been stripped from your copy of libpng, you can find it at 302 * <http://www.libpng.org/pub/png/libpng-manual.txt> 303 * 304 * If you just need to read a PNG file and don't want to read the documentation 305 * skip to the end of this file and read the section entitled 'simplified API'. 306 */ 307 308 /* Version information for png.h - this should match the version in png.c */ 309 #define PNG_LIBPNG_VER_STRING "1.6.37" 310 #define PNG_HEADER_VERSION_STRING " libpng version 1.6.37 - April 14, 2019\n" 311 312 #define PNG_LIBPNG_VER_SONUM 16 313 #define PNG_LIBPNG_VER_DLLNUM 16 314 315 /* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */ 316 #define PNG_LIBPNG_VER_MAJOR 1 317 #define PNG_LIBPNG_VER_MINOR 6 318 #define PNG_LIBPNG_VER_RELEASE 37 319 320 /* This should be zero for a public release, or non-zero for a 321 * development version. [Deprecated] 322 */ 323 #define PNG_LIBPNG_VER_BUILD 0 324 325 /* Release Status */ 326 #define PNG_LIBPNG_BUILD_ALPHA 1 327 #define PNG_LIBPNG_BUILD_BETA 2 328 #define PNG_LIBPNG_BUILD_RC 3 329 #define PNG_LIBPNG_BUILD_STABLE 4 330 #define PNG_LIBPNG_BUILD_RELEASE_STATUS_MASK 7 331 332 /* Release-Specific Flags */ 333 #define PNG_LIBPNG_BUILD_PATCH 8 /* Can be OR'ed with 334 PNG_LIBPNG_BUILD_STABLE only */ 335 #define PNG_LIBPNG_BUILD_PRIVATE 16 /* Cannot be OR'ed with 336 PNG_LIBPNG_BUILD_SPECIAL */ 337 #define PNG_LIBPNG_BUILD_SPECIAL 32 /* Cannot be OR'ed with 338 PNG_LIBPNG_BUILD_PRIVATE */ 339 340 #define PNG_LIBPNG_BUILD_BASE_TYPE PNG_LIBPNG_BUILD_STABLE 341 342 /* Careful here. At one time, Guy wanted to use 082, but that 343 * would be octal. We must not include leading zeros. 344 * Versions 0.7 through 1.0.0 were in the range 0 to 100 here 345 * (only version 1.0.0 was mis-numbered 100 instead of 10000). 346 * From version 1.0.1 it is: 347 * XXYYZZ, where XX=major, YY=minor, ZZ=release 348 */ 349 #define PNG_LIBPNG_VER 10637 /* 1.6.37 */ 350 351 /* Library configuration: these options cannot be changed after 352 * the library has been built. 353 */ 354 #ifndef PNGLCONF_H 355 /* If pnglibconf.h is missing, you can 356 * copy scripts/pnglibconf.h.prebuilt to pnglibconf.h 357 */ 358 # include "pnglibconf.h" 359 #endif 360 361 #ifndef PNG_VERSION_INFO_ONLY 362 /* Machine specific configuration. */ 363 # include "pngconf.h" 364 #endif 365 366 /* 367 * Added at libpng-1.2.8 368 * 369 * Ref MSDN: Private as priority over Special 370 * VS_FF_PRIVATEBUILD File *was not* built using standard release 371 * procedures. If this value is given, the StringFileInfo block must 372 * contain a PrivateBuild string. 373 * 374 * VS_FF_SPECIALBUILD File *was* built by the original company using 375 * standard release procedures but is a variation of the standard 376 * file of the same version number. If this value is given, the 377 * StringFileInfo block must contain a SpecialBuild string. 378 */ 379 380 #ifdef PNG_USER_PRIVATEBUILD /* From pnglibconf.h */ 381 # define PNG_LIBPNG_BUILD_TYPE \ 382 (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_PRIVATE) 383 #else 384 # ifdef PNG_LIBPNG_SPECIALBUILD 385 # define PNG_LIBPNG_BUILD_TYPE \ 386 (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_SPECIAL) 387 # else 388 # define PNG_LIBPNG_BUILD_TYPE (PNG_LIBPNG_BUILD_BASE_TYPE) 389 # endif 390 #endif 391 392 #ifndef PNG_VERSION_INFO_ONLY 393 394 /* Inhibit C++ name-mangling for libpng functions but not for system calls. */ 395 #ifdef __cplusplus 396 extern "C" { 397 #endif /* __cplusplus */ 398 399 /* Version information for C files, stored in png.c. This had better match 400 * the version above. 401 */ 402 #define png_libpng_ver png_get_header_ver(NULL) 403 404 /* This file is arranged in several sections: 405 * 406 * 1. [omitted] 407 * 2. Any configuration options that can be specified by for the application 408 * code when it is built. (Build time configuration is in pnglibconf.h) 409 * 3. Type definitions (base types are defined in pngconf.h), structure 410 * definitions. 411 * 4. Exported library functions. 412 * 5. Simplified API. 413 * 6. Implementation options. 414 * 415 * The library source code has additional files (principally pngpriv.h) that 416 * allow configuration of the library. 417 */ 418 419 /* Section 1: [omitted] */ 420 421 /* Section 2: run time configuration 422 * See pnglibconf.h for build time configuration 423 * 424 * Run time configuration allows the application to choose between 425 * implementations of certain arithmetic APIs. The default is set 426 * at build time and recorded in pnglibconf.h, but it is safe to 427 * override these (and only these) settings. Note that this won't 428 * change what the library does, only application code, and the 429 * settings can (and probably should) be made on a per-file basis 430 * by setting the #defines before including png.h 431 * 432 * Use macros to read integers from PNG data or use the exported 433 * functions? 434 * PNG_USE_READ_MACROS: use the macros (see below) Note that 435 * the macros evaluate their argument multiple times. 436 * PNG_NO_USE_READ_MACROS: call the relevant library function. 437 * 438 * Use the alternative algorithm for compositing alpha samples that 439 * does not use division? 440 * PNG_READ_COMPOSITE_NODIV_SUPPORTED: use the 'no division' 441 * algorithm. 442 * PNG_NO_READ_COMPOSITE_NODIV: use the 'division' algorithm. 443 * 444 * How to handle benign errors if PNG_ALLOW_BENIGN_ERRORS is 445 * false? 446 * PNG_ALLOW_BENIGN_ERRORS: map calls to the benign error 447 * APIs to png_warning. 448 * Otherwise the calls are mapped to png_error. 449 */ 450 451 /* Section 3: type definitions, including structures and compile time 452 * constants. 453 * See pngconf.h for base types that vary by machine/system 454 */ 455 456 /* This triggers a compiler error in png.c, if png.c and png.h 457 * do not agree upon the version number. 458 */ 459 typedef char* png_libpng_version_1_6_37; 460 461 /* Basic control structions. Read libpng-manual.txt or libpng.3 for more info. 462 * 463 * png_struct is the cache of information used while reading or writing a single 464 * PNG file. One of these is always required, although the simplified API 465 * (below) hides the creation and destruction of it. 466 */ 467 typedef struct png_struct_def png_struct; 468 typedef const png_struct * png_const_structp; 469 typedef png_struct * png_structp; 470 typedef png_struct * * png_structpp; 471 472 /* png_info contains information read from or to be written to a PNG file. One 473 * or more of these must exist while reading or creating a PNG file. The 474 * information is not used by libpng during read but is used to control what 475 * gets written when a PNG file is created. "png_get_" function calls read 476 * information during read and "png_set_" functions calls write information 477 * when creating a PNG. 478 * been moved into a separate header file that is not accessible to 479 * applications. Read libpng-manual.txt or libpng.3 for more info. 480 */ 481 typedef struct png_info_def png_info; 482 typedef png_info * png_infop; 483 typedef const png_info * png_const_infop; 484 typedef png_info * * png_infopp; 485 486 /* Types with names ending 'p' are pointer types. The corresponding types with 487 * names ending 'rp' are identical pointer types except that the pointer is 488 * marked 'restrict', which means that it is the only pointer to the object 489 * passed to the function. Applications should not use the 'restrict' types; 490 * it is always valid to pass 'p' to a pointer with a function argument of the 491 * corresponding 'rp' type. Different compilers have different rules with 492 * regard to type matching in the presence of 'restrict'. For backward 493 * compatibility libpng callbacks never have 'restrict' in their parameters and, 494 * consequentially, writing portable application code is extremely difficult if 495 * an attempt is made to use 'restrict'. 496 */ 497 typedef png_struct * PNG_RESTRICT png_structrp; 498 typedef const png_struct * PNG_RESTRICT png_const_structrp; 499 typedef png_info * PNG_RESTRICT png_inforp; 500 typedef const png_info * PNG_RESTRICT png_const_inforp; 501 502 /* Three color definitions. The order of the red, green, and blue, (and the 503 * exact size) is not important, although the size of the fields need to 504 * be png_byte or png_uint_16 (as defined below). 505 */ 506 typedef struct png_color_struct 507 { 508 png_byte red; 509 png_byte green; 510 png_byte blue; 511 } png_color; 512 typedef png_color * png_colorp; 513 typedef const png_color * png_const_colorp; 514 typedef png_color * * png_colorpp; 515 516 typedef struct png_color_16_struct 517 { 518 png_byte index; /* used for palette files */ 519 png_uint_16 red; /* for use in red green blue files */ 520 png_uint_16 green; 521 png_uint_16 blue; 522 png_uint_16 gray; /* for use in grayscale files */ 523 } png_color_16; 524 typedef png_color_16 * png_color_16p; 525 typedef const png_color_16 * png_const_color_16p; 526 typedef png_color_16 * * png_color_16pp; 527 528 typedef struct png_color_8_struct 529 { 530 png_byte red; /* for use in red green blue files */ 531 png_byte green; 532 png_byte blue; 533 png_byte gray; /* for use in grayscale files */ 534 png_byte alpha; /* for alpha channel files */ 535 } png_color_8; 536 typedef png_color_8 * png_color_8p; 537 typedef const png_color_8 * png_const_color_8p; 538 typedef png_color_8 * * png_color_8pp; 539 540 /* 541 * The following two structures are used for the in-core representation 542 * of sPLT chunks. 543 */ 544 typedef struct png_sPLT_entry_struct 545 { 546 png_uint_16 red; 547 png_uint_16 green; 548 png_uint_16 blue; 549 png_uint_16 alpha; 550 png_uint_16 frequency; 551 } png_sPLT_entry; 552 typedef png_sPLT_entry * png_sPLT_entryp; 553 typedef const png_sPLT_entry * png_const_sPLT_entryp; 554 typedef png_sPLT_entry * * png_sPLT_entrypp; 555 556 /* When the depth of the sPLT palette is 8 bits, the color and alpha samples 557 * occupy the LSB of their respective members, and the MSB of each member 558 * is zero-filled. The frequency member always occupies the full 16 bits. 559 */ 560 561 typedef struct png_sPLT_struct 562 { 563 png_charp name; /* palette name */ 564 png_byte depth; /* depth of palette samples */ 565 png_sPLT_entryp entries; /* palette entries */ 566 png_int_32 nentries; /* number of palette entries */ 567 } png_sPLT_t; 568 typedef png_sPLT_t * png_sPLT_tp; 569 typedef const png_sPLT_t * png_const_sPLT_tp; 570 typedef png_sPLT_t * * png_sPLT_tpp; 571 572 #ifdef PNG_TEXT_SUPPORTED 573 /* png_text holds the contents of a text/ztxt/itxt chunk in a PNG file, 574 * and whether that contents is compressed or not. The "key" field 575 * points to a regular zero-terminated C string. The "text" fields can be a 576 * regular C string, an empty string, or a NULL pointer. 577 * However, the structure returned by png_get_text() will always contain 578 * the "text" field as a regular zero-terminated C string (possibly 579 * empty), never a NULL pointer, so it can be safely used in printf() and 580 * other string-handling functions. Note that the "itxt_length", "lang", and 581 * "lang_key" members of the structure only exist when the library is built 582 * with iTXt chunk support. Prior to libpng-1.4.0 the library was built by 583 * default without iTXt support. Also note that when iTXt *is* supported, 584 * the "lang" and "lang_key" fields contain NULL pointers when the 585 * "compression" field contains * PNG_TEXT_COMPRESSION_NONE or 586 * PNG_TEXT_COMPRESSION_zTXt. Note that the "compression value" is not the 587 * same as what appears in the PNG tEXt/zTXt/iTXt chunk's "compression flag" 588 * which is always 0 or 1, or its "compression method" which is always 0. 589 */ 590 typedef struct png_text_struct 591 { 592 int compression; /* compression value: 593 -1: tEXt, none 594 0: zTXt, deflate 595 1: iTXt, none 596 2: iTXt, deflate */ 597 png_charp key; /* keyword, 1-79 character description of "text" */ 598 png_charp text; /* comment, may be an empty string (ie "") 599 or a NULL pointer */ 600 size_t text_length; /* length of the text string */ 601 size_t itxt_length; /* length of the itxt string */ 602 png_charp lang; /* language code, 0-79 characters 603 or a NULL pointer */ 604 png_charp lang_key; /* keyword translated UTF-8 string, 0 or more 605 chars or a NULL pointer */ 606 } png_text; 607 typedef png_text * png_textp; 608 typedef const png_text * png_const_textp; 609 typedef png_text * * png_textpp; 610 #endif 611 612 /* Supported compression types for text in PNG files (tEXt, and zTXt). 613 * The values of the PNG_TEXT_COMPRESSION_ defines should NOT be changed. */ 614 #define PNG_TEXT_COMPRESSION_NONE_WR -3 615 #define PNG_TEXT_COMPRESSION_zTXt_WR -2 616 #define PNG_TEXT_COMPRESSION_NONE -1 617 #define PNG_TEXT_COMPRESSION_zTXt 0 618 #define PNG_ITXT_COMPRESSION_NONE 1 619 #define PNG_ITXT_COMPRESSION_zTXt 2 620 #define PNG_TEXT_COMPRESSION_LAST 3 /* Not a valid value */ 621 622 /* png_time is a way to hold the time in an machine independent way. 623 * Two conversions are provided, both from time_t and struct tm. There 624 * is no portable way to convert to either of these structures, as far 625 * as I know. If you know of a portable way, send it to me. As a side 626 * note - PNG has always been Year 2000 compliant! 627 */ 628 typedef struct png_time_struct 629 { 630 png_uint_16 year; /* full year, as in, 1995 */ 631 png_byte month; /* month of year, 1 - 12 */ 632 png_byte day; /* day of month, 1 - 31 */ 633 png_byte hour; /* hour of day, 0 - 23 */ 634 png_byte minute; /* minute of hour, 0 - 59 */ 635 png_byte second; /* second of minute, 0 - 60 (for leap seconds) */ 636 } png_time; 637 typedef png_time * png_timep; 638 typedef const png_time * png_const_timep; 639 typedef png_time * * png_timepp; 640 641 #if defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED) ||\ 642 defined(PNG_USER_CHUNKS_SUPPORTED) 643 /* png_unknown_chunk is a structure to hold queued chunks for which there is 644 * no specific support. The idea is that we can use this to queue 645 * up private chunks for output even though the library doesn't actually 646 * know about their semantics. 647 * 648 * The data in the structure is set by libpng on read and used on write. 649 */ 650 typedef struct png_unknown_chunk_t 651 { 652 png_byte name[5]; /* Textual chunk name with '\0' terminator */ 653 png_byte *data; /* Data, should not be modified on read! */ 654 size_t size; 655 656 /* On write 'location' must be set using the flag values listed below. 657 * Notice that on read it is set by libpng however the values stored have 658 * more bits set than are listed below. Always treat the value as a 659 * bitmask. On write set only one bit - setting multiple bits may cause the 660 * chunk to be written in multiple places. 661 */ 662 png_byte location; /* mode of operation at read time */ 663 } 664 png_unknown_chunk; 665 666 typedef png_unknown_chunk * png_unknown_chunkp; 667 typedef const png_unknown_chunk * png_const_unknown_chunkp; 668 typedef png_unknown_chunk * * png_unknown_chunkpp; 669 #endif 670 671 /* Flag values for the unknown chunk location byte. */ 672 #define PNG_HAVE_IHDR 0x01 673 #define PNG_HAVE_PLTE 0x02 674 #define PNG_AFTER_IDAT 0x08 675 676 /* Maximum positive integer used in PNG is (2^31)-1 */ 677 #define PNG_UINT_31_MAX ((png_uint_32)0x7fffffffL) 678 #define PNG_UINT_32_MAX ((png_uint_32)(-1)) 679 #define PNG_SIZE_MAX ((size_t)(-1)) 680 681 /* These are constants for fixed point values encoded in the 682 * PNG specification manner (x100000) 683 */ 684 #define PNG_FP_1 100000 685 #define PNG_FP_HALF 50000 686 #define PNG_FP_MAX ((png_fixed_point)0x7fffffffL) 687 #define PNG_FP_MIN (-PNG_FP_MAX) 688 689 /* These describe the color_type field in png_info. */ 690 /* color type masks */ 691 #define PNG_COLOR_MASK_PALETTE 1 692 #define PNG_COLOR_MASK_COLOR 2 693 #define PNG_COLOR_MASK_ALPHA 4 694 695 /* color types. Note that not all combinations are legal */ 696 #define PNG_COLOR_TYPE_GRAY 0 697 #define PNG_COLOR_TYPE_PALETTE (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE) 698 #define PNG_COLOR_TYPE_RGB (PNG_COLOR_MASK_COLOR) 699 #define PNG_COLOR_TYPE_RGB_ALPHA (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_ALPHA) 700 #define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA) 701 /* aliases */ 702 #define PNG_COLOR_TYPE_RGBA PNG_COLOR_TYPE_RGB_ALPHA 703 #define PNG_COLOR_TYPE_GA PNG_COLOR_TYPE_GRAY_ALPHA 704 705 /* This is for compression type. PNG 1.0-1.2 only define the single type. */ 706 #define PNG_COMPRESSION_TYPE_BASE 0 /* Deflate method 8, 32K window */ 707 #define PNG_COMPRESSION_TYPE_DEFAULT PNG_COMPRESSION_TYPE_BASE 708 709 /* This is for filter type. PNG 1.0-1.2 only define the single type. */ 710 #define PNG_FILTER_TYPE_BASE 0 /* Single row per-byte filtering */ 711 #define PNG_INTRAPIXEL_DIFFERENCING 64 /* Used only in MNG datastreams */ 712 #define PNG_FILTER_TYPE_DEFAULT PNG_FILTER_TYPE_BASE 713 714 /* These are for the interlacing type. These values should NOT be changed. */ 715 #define PNG_INTERLACE_NONE 0 /* Non-interlaced image */ 716 #define PNG_INTERLACE_ADAM7 1 /* Adam7 interlacing */ 717 #define PNG_INTERLACE_LAST 2 /* Not a valid value */ 718 719 /* These are for the oFFs chunk. These values should NOT be changed. */ 720 #define PNG_OFFSET_PIXEL 0 /* Offset in pixels */ 721 #define PNG_OFFSET_MICROMETER 1 /* Offset in micrometers (1/10^6 meter) */ 722 #define PNG_OFFSET_LAST 2 /* Not a valid value */ 723 724 /* These are for the pCAL chunk. These values should NOT be changed. */ 725 #define PNG_EQUATION_LINEAR 0 /* Linear transformation */ 726 #define PNG_EQUATION_BASE_E 1 /* Exponential base e transform */ 727 #define PNG_EQUATION_ARBITRARY 2 /* Arbitrary base exponential transform */ 728 #define PNG_EQUATION_HYPERBOLIC 3 /* Hyperbolic sine transformation */ 729 #define PNG_EQUATION_LAST 4 /* Not a valid value */ 730 731 /* These are for the sCAL chunk. These values should NOT be changed. */ 732 #define PNG_SCALE_UNKNOWN 0 /* unknown unit (image scale) */ 733 #define PNG_SCALE_METER 1 /* meters per pixel */ 734 #define PNG_SCALE_RADIAN 2 /* radians per pixel */ 735 #define PNG_SCALE_LAST 3 /* Not a valid value */ 736 737 /* These are for the pHYs chunk. These values should NOT be changed. */ 738 #define PNG_RESOLUTION_UNKNOWN 0 /* pixels/unknown unit (aspect ratio) */ 739 #define PNG_RESOLUTION_METER 1 /* pixels/meter */ 740 #define PNG_RESOLUTION_LAST 2 /* Not a valid value */ 741 742 /* These are for the sRGB chunk. These values should NOT be changed. */ 743 #define PNG_sRGB_INTENT_PERCEPTUAL 0 744 #define PNG_sRGB_INTENT_RELATIVE 1 745 #define PNG_sRGB_INTENT_SATURATION 2 746 #define PNG_sRGB_INTENT_ABSOLUTE 3 747 #define PNG_sRGB_INTENT_LAST 4 /* Not a valid value */ 748 749 /* This is for text chunks */ 750 #define PNG_KEYWORD_MAX_LENGTH 79 751 752 /* Maximum number of entries in PLTE/sPLT/tRNS arrays */ 753 #define PNG_MAX_PALETTE_LENGTH 256 754 755 /* These determine if an ancillary chunk's data has been successfully read 756 * from the PNG header, or if the application has filled in the corresponding 757 * data in the info_struct to be written into the output file. The values 758 * of the PNG_INFO_<chunk> defines should NOT be changed. 759 */ 760 #define PNG_INFO_gAMA 0x0001U 761 #define PNG_INFO_sBIT 0x0002U 762 #define PNG_INFO_cHRM 0x0004U 763 #define PNG_INFO_PLTE 0x0008U 764 #define PNG_INFO_tRNS 0x0010U 765 #define PNG_INFO_bKGD 0x0020U 766 #define PNG_INFO_hIST 0x0040U 767 #define PNG_INFO_pHYs 0x0080U 768 #define PNG_INFO_oFFs 0x0100U 769 #define PNG_INFO_tIME 0x0200U 770 #define PNG_INFO_pCAL 0x0400U 771 #define PNG_INFO_sRGB 0x0800U /* GR-P, 0.96a */ 772 #define PNG_INFO_iCCP 0x1000U /* ESR, 1.0.6 */ 773 #define PNG_INFO_sPLT 0x2000U /* ESR, 1.0.6 */ 774 #define PNG_INFO_sCAL 0x4000U /* ESR, 1.0.6 */ 775 #define PNG_INFO_IDAT 0x8000U /* ESR, 1.0.6 */ 776 #define PNG_INFO_eXIf 0x10000U /* GR-P, 1.6.31 */ 777 778 /* This is used for the transformation routines, as some of them 779 * change these values for the row. It also should enable using 780 * the routines for other purposes. 781 */ 782 typedef struct png_row_info_struct 783 { 784 png_uint_32 width; /* width of row */ 785 size_t rowbytes; /* number of bytes in row */ 786 png_byte color_type; /* color type of row */ 787 png_byte bit_depth; /* bit depth of row */ 788 png_byte channels; /* number of channels (1, 2, 3, or 4) */ 789 png_byte pixel_depth; /* bits per pixel (depth * channels) */ 790 } png_row_info; 791 792 typedef png_row_info * png_row_infop; 793 typedef png_row_info * * png_row_infopp; 794 795 /* These are the function types for the I/O functions and for the functions 796 * that allow the user to override the default I/O functions with his or her 797 * own. The png_error_ptr type should match that of user-supplied warning 798 * and error functions, while the png_rw_ptr type should match that of the 799 * user read/write data functions. Note that the 'write' function must not 800 * modify the buffer it is passed. The 'read' function, on the other hand, is 801 * expected to return the read data in the buffer. 802 */ 803 typedef PNG_CALLBACK(void, *png_error_ptr, (png_structp, png_const_charp)); 804 typedef PNG_CALLBACK(void, *png_rw_ptr, (png_structp, png_bytep, size_t)); 805 typedef PNG_CALLBACK(void, *png_flush_ptr, (png_structp)); 806 typedef PNG_CALLBACK(void, *png_read_status_ptr, (png_structp, png_uint_32, 807 int)); 808 typedef PNG_CALLBACK(void, *png_write_status_ptr, (png_structp, png_uint_32, 809 int)); 810 811 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED 812 typedef PNG_CALLBACK(void, *png_progressive_info_ptr, (png_structp, png_infop)); 813 typedef PNG_CALLBACK(void, *png_progressive_end_ptr, (png_structp, png_infop)); 814 815 /* The following callback receives png_uint_32 row_number, int pass for the 816 * png_bytep data of the row. When transforming an interlaced image the 817 * row number is the row number within the sub-image of the interlace pass, so 818 * the value will increase to the height of the sub-image (not the full image) 819 * then reset to 0 for the next pass. 820 * 821 * Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to 822 * find the output pixel (x,y) given an interlaced sub-image pixel 823 * (row,col,pass). (See below for these macros.) 824 */ 825 typedef PNG_CALLBACK(void, *png_progressive_row_ptr, (png_structp, png_bytep, 826 png_uint_32, int)); 827 #endif 828 829 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \ 830 defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) 831 typedef PNG_CALLBACK(void, *png_user_transform_ptr, (png_structp, png_row_infop, 832 png_bytep)); 833 #endif 834 835 #ifdef PNG_USER_CHUNKS_SUPPORTED 836 typedef PNG_CALLBACK(int, *png_user_chunk_ptr, (png_structp, 837 png_unknown_chunkp)); 838 #endif 839 #ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED 840 /* not used anywhere */ 841 /* typedef PNG_CALLBACK(void, *png_unknown_chunk_ptr, (png_structp)); */ 842 #endif 843 844 #ifdef PNG_SETJMP_SUPPORTED 845 /* This must match the function definition in <setjmp.h>, and the application 846 * must include this before png.h to obtain the definition of jmp_buf. The 847 * function is required to be PNG_NORETURN, but this is not checked. If the 848 * function does return the application will crash via an abort() or similar 849 * system level call. 850 * 851 * If you get a warning here while building the library you may need to make 852 * changes to ensure that pnglibconf.h records the calling convention used by 853 * your compiler. This may be very difficult - try using a different compiler 854 * to build the library! 855 */ 856 PNG_FUNCTION(void, (PNGCAPI *png_longjmp_ptr), PNGARG((jmp_buf, int)), typedef); 857 #endif 858 859 /* Transform masks for the high-level interface */ 860 #define PNG_TRANSFORM_IDENTITY 0x0000 /* read and write */ 861 #define PNG_TRANSFORM_STRIP_16 0x0001 /* read only */ 862 #define PNG_TRANSFORM_STRIP_ALPHA 0x0002 /* read only */ 863 #define PNG_TRANSFORM_PACKING 0x0004 /* read and write */ 864 #define PNG_TRANSFORM_PACKSWAP 0x0008 /* read and write */ 865 #define PNG_TRANSFORM_EXPAND 0x0010 /* read only */ 866 #define PNG_TRANSFORM_INVERT_MONO 0x0020 /* read and write */ 867 #define PNG_TRANSFORM_SHIFT 0x0040 /* read and write */ 868 #define PNG_TRANSFORM_BGR 0x0080 /* read and write */ 869 #define PNG_TRANSFORM_SWAP_ALPHA 0x0100 /* read and write */ 870 #define PNG_TRANSFORM_SWAP_ENDIAN 0x0200 /* read and write */ 871 #define PNG_TRANSFORM_INVERT_ALPHA 0x0400 /* read and write */ 872 #define PNG_TRANSFORM_STRIP_FILLER 0x0800 /* write only */ 873 /* Added to libpng-1.2.34 */ 874 #define PNG_TRANSFORM_STRIP_FILLER_BEFORE PNG_TRANSFORM_STRIP_FILLER 875 #define PNG_TRANSFORM_STRIP_FILLER_AFTER 0x1000 /* write only */ 876 /* Added to libpng-1.4.0 */ 877 #define PNG_TRANSFORM_GRAY_TO_RGB 0x2000 /* read only */ 878 /* Added to libpng-1.5.4 */ 879 #define PNG_TRANSFORM_EXPAND_16 0x4000 /* read only */ 880 #if INT_MAX >= 0x8000 /* else this might break */ 881 #define PNG_TRANSFORM_SCALE_16 0x8000 /* read only */ 882 #endif 883 884 /* Flags for MNG supported features */ 885 #define PNG_FLAG_MNG_EMPTY_PLTE 0x01 886 #define PNG_FLAG_MNG_FILTER_64 0x04 887 #define PNG_ALL_MNG_FEATURES 0x05 888 889 /* NOTE: prior to 1.5 these functions had no 'API' style declaration, 890 * this allowed the zlib default functions to be used on Windows 891 * platforms. In 1.5 the zlib default malloc (which just calls malloc and 892 * ignores the first argument) should be completely compatible with the 893 * following. 894 */ 895 typedef PNG_CALLBACK(png_voidp, *png_malloc_ptr, (png_structp, 896 png_alloc_size_t)); 897 typedef PNG_CALLBACK(void, *png_free_ptr, (png_structp, png_voidp)); 898 899 /* Section 4: exported functions 900 * Here are the function definitions most commonly used. This is not 901 * the place to find out how to use libpng. See libpng-manual.txt for the 902 * full explanation, see example.c for the summary. This just provides 903 * a simple one line description of the use of each function. 904 * 905 * The PNG_EXPORT() and PNG_EXPORTA() macros used below are defined in 906 * pngconf.h and in the *.dfn files in the scripts directory. 907 * 908 * PNG_EXPORT(ordinal, type, name, (args)); 909 * 910 * ordinal: ordinal that is used while building 911 * *.def files. The ordinal value is only 912 * relevant when preprocessing png.h with 913 * the *.dfn files for building symbol table 914 * entries, and are removed by pngconf.h. 915 * type: return type of the function 916 * name: function name 917 * args: function arguments, with types 918 * 919 * When we wish to append attributes to a function prototype we use 920 * the PNG_EXPORTA() macro instead. 921 * 922 * PNG_EXPORTA(ordinal, type, name, (args), attributes); 923 * 924 * ordinal, type, name, and args: same as in PNG_EXPORT(). 925 * attributes: function attributes 926 */ 927 928 /* Returns the version number of the library */ 929 PNG_EXPORT(1, png_uint_32, png_access_version_number, (void)); 930 931 /* Tell lib we have already handled the first <num_bytes> magic bytes. 932 * Handling more than 8 bytes from the beginning of the file is an error. 933 */ 934 PNG_EXPORT(2, void, png_set_sig_bytes, (png_structrp png_ptr, int num_bytes)); 935 936 /* Check sig[start] through sig[start + num_to_check - 1] to see if it's a 937 * PNG file. Returns zero if the supplied bytes match the 8-byte PNG 938 * signature, and non-zero otherwise. Having num_to_check == 0 or 939 * start > 7 will always fail (ie return non-zero). 940 */ 941 PNG_EXPORT(3, int, png_sig_cmp, (png_const_bytep sig, size_t start, 942 size_t num_to_check)); 943 944 /* Simple signature checking function. This is the same as calling 945 * png_check_sig(sig, n) := !png_sig_cmp(sig, 0, n). 946 */ 947 #define png_check_sig(sig, n) !png_sig_cmp((sig), 0, (n)) 948 949 /* Allocate and initialize png_ptr struct for reading, and any other memory. */ 950 PNG_EXPORTA(4, png_structp, png_create_read_struct, 951 (png_const_charp user_png_ver, png_voidp error_ptr, 952 png_error_ptr error_fn, png_error_ptr warn_fn), 953 PNG_ALLOCATED); 954 955 /* Allocate and initialize png_ptr struct for writing, and any other memory */ 956 PNG_EXPORTA(5, png_structp, png_create_write_struct, 957 (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn, 958 png_error_ptr warn_fn), 959 PNG_ALLOCATED); 960 961 PNG_EXPORT(6, size_t, png_get_compression_buffer_size, 962 (png_const_structrp png_ptr)); 963 964 PNG_EXPORT(7, void, png_set_compression_buffer_size, (png_structrp png_ptr, 965 size_t size)); 966 967 /* Moved from pngconf.h in 1.4.0 and modified to ensure setjmp/longjmp 968 * match up. 969 */ 970 #ifdef PNG_SETJMP_SUPPORTED 971 /* This function returns the jmp_buf built in to *png_ptr. It must be 972 * supplied with an appropriate 'longjmp' function to use on that jmp_buf 973 * unless the default error function is overridden in which case NULL is 974 * acceptable. The size of the jmp_buf is checked against the actual size 975 * allocated by the library - the call will return NULL on a mismatch 976 * indicating an ABI mismatch. 977 */ 978 PNG_EXPORT(8, jmp_buf*, png_set_longjmp_fn, (png_structrp png_ptr, 979 png_longjmp_ptr longjmp_fn, size_t jmp_buf_size)); 980 # define png_jmpbuf(png_ptr) \ 981 (*png_set_longjmp_fn((png_ptr), longjmp, (sizeof (jmp_buf)))) 982 #else 983 # define png_jmpbuf(png_ptr) \ 984 (LIBPNG_WAS_COMPILED_WITH__PNG_NO_SETJMP) 985 #endif 986 /* This function should be used by libpng applications in place of 987 * longjmp(png_ptr->jmpbuf, val). If longjmp_fn() has been set, it 988 * will use it; otherwise it will call PNG_ABORT(). This function was 989 * added in libpng-1.5.0. 990 */ 991 PNG_EXPORTA(9, void, png_longjmp, (png_const_structrp png_ptr, int val), 992 PNG_NORETURN); 993 994 #ifdef PNG_READ_SUPPORTED 995 /* Reset the compression stream */ 996 PNG_EXPORTA(10, int, png_reset_zstream, (png_structrp png_ptr), PNG_DEPRECATED); 997 #endif 998 999 /* New functions added in libpng-1.0.2 (not enabled by default until 1.2.0) */ 1000 #ifdef PNG_USER_MEM_SUPPORTED 1001 PNG_EXPORTA(11, png_structp, png_create_read_struct_2, 1002 (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn, 1003 png_error_ptr warn_fn, 1004 png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn), 1005 PNG_ALLOCATED); 1006 PNG_EXPORTA(12, png_structp, png_create_write_struct_2, 1007 (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn, 1008 png_error_ptr warn_fn, 1009 png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn), 1010 PNG_ALLOCATED); 1011 #endif 1012 1013 /* Write the PNG file signature. */ 1014 PNG_EXPORT(13, void, png_write_sig, (png_structrp png_ptr)); 1015 1016 /* Write a PNG chunk - size, type, (optional) data, CRC. */ 1017 PNG_EXPORT(14, void, png_write_chunk, (png_structrp png_ptr, png_const_bytep 1018 chunk_name, png_const_bytep data, size_t length)); 1019 1020 /* Write the start of a PNG chunk - length and chunk name. */ 1021 PNG_EXPORT(15, void, png_write_chunk_start, (png_structrp png_ptr, 1022 png_const_bytep chunk_name, png_uint_32 length)); 1023 1024 /* Write the data of a PNG chunk started with png_write_chunk_start(). */ 1025 PNG_EXPORT(16, void, png_write_chunk_data, (png_structrp png_ptr, 1026 png_const_bytep data, size_t length)); 1027 1028 /* Finish a chunk started with png_write_chunk_start() (includes CRC). */ 1029 PNG_EXPORT(17, void, png_write_chunk_end, (png_structrp png_ptr)); 1030 1031 /* Allocate and initialize the info structure */ 1032 PNG_EXPORTA(18, png_infop, png_create_info_struct, (png_const_structrp png_ptr), 1033 PNG_ALLOCATED); 1034 1035 /* DEPRECATED: this function allowed init structures to be created using the 1036 * default allocation method (typically malloc). Use is deprecated in 1.6.0 and 1037 * the API will be removed in the future. 1038 */ 1039 PNG_EXPORTA(19, void, png_info_init_3, (png_infopp info_ptr, 1040 size_t png_info_struct_size), PNG_DEPRECATED); 1041 1042 /* Writes all the PNG information before the image. */ 1043 PNG_EXPORT(20, void, png_write_info_before_PLTE, 1044 (png_structrp png_ptr, png_const_inforp info_ptr)); 1045 PNG_EXPORT(21, void, png_write_info, 1046 (png_structrp png_ptr, png_const_inforp info_ptr)); 1047 1048 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED 1049 /* Read the information before the actual image data. */ 1050 PNG_EXPORT(22, void, png_read_info, 1051 (png_structrp png_ptr, png_inforp info_ptr)); 1052 #endif 1053 1054 #ifdef PNG_TIME_RFC1123_SUPPORTED 1055 /* Convert to a US string format: there is no localization support in this 1056 * routine. The original implementation used a 29 character buffer in 1057 * png_struct, this will be removed in future versions. 1058 */ 1059 #if PNG_LIBPNG_VER < 10700 1060 /* To do: remove this from libpng17 (and from libpng17/png.c and pngstruct.h) */ 1061 PNG_EXPORTA(23, png_const_charp, png_convert_to_rfc1123, (png_structrp png_ptr, 1062 png_const_timep ptime),PNG_DEPRECATED); 1063 #endif 1064 PNG_EXPORT(241, int, png_convert_to_rfc1123_buffer, (char out[29], 1065 png_const_timep ptime)); 1066 #endif 1067 1068 #ifdef PNG_CONVERT_tIME_SUPPORTED 1069 /* Convert from a struct tm to png_time */ 1070 PNG_EXPORT(24, void, png_convert_from_struct_tm, (png_timep ptime, 1071 const struct tm * ttime)); 1072 1073 /* Convert from time_t to png_time. Uses gmtime() */ 1074 PNG_EXPORT(25, void, png_convert_from_time_t, (png_timep ptime, time_t ttime)); 1075 #endif /* CONVERT_tIME */ 1076 1077 #ifdef PNG_READ_EXPAND_SUPPORTED 1078 /* Expand data to 24-bit RGB, or 8-bit grayscale, with alpha if available. */ 1079 PNG_EXPORT(26, void, png_set_expand, (png_structrp png_ptr)); 1080 PNG_EXPORT(27, void, png_set_expand_gray_1_2_4_to_8, (png_structrp png_ptr)); 1081 PNG_EXPORT(28, void, png_set_palette_to_rgb, (png_structrp png_ptr)); 1082 PNG_EXPORT(29, void, png_set_tRNS_to_alpha, (png_structrp png_ptr)); 1083 #endif 1084 1085 #ifdef PNG_READ_EXPAND_16_SUPPORTED 1086 /* Expand to 16-bit channels, forces conversion of palette to RGB and expansion 1087 * of a tRNS chunk if present. 1088 */ 1089 PNG_EXPORT(221, void, png_set_expand_16, (png_structrp png_ptr)); 1090 #endif 1091 1092 #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED) 1093 /* Use blue, green, red order for pixels. */ 1094 PNG_EXPORT(30, void, png_set_bgr, (png_structrp png_ptr)); 1095 #endif 1096 1097 #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED 1098 /* Expand the grayscale to 24-bit RGB if necessary. */ 1099 PNG_EXPORT(31, void, png_set_gray_to_rgb, (png_structrp png_ptr)); 1100 #endif 1101 1102 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED 1103 /* Reduce RGB to grayscale. */ 1104 #define PNG_ERROR_ACTION_NONE 1 1105 #define PNG_ERROR_ACTION_WARN 2 1106 #define PNG_ERROR_ACTION_ERROR 3 1107 #define PNG_RGB_TO_GRAY_DEFAULT (-1)/*for red/green coefficients*/ 1108 1109 PNG_FP_EXPORT(32, void, png_set_rgb_to_gray, (png_structrp png_ptr, 1110 int error_action, double red, double green)) 1111 PNG_FIXED_EXPORT(33, void, png_set_rgb_to_gray_fixed, (png_structrp png_ptr, 1112 int error_action, png_fixed_point red, png_fixed_point green)) 1113 1114 PNG_EXPORT(34, png_byte, png_get_rgb_to_gray_status, (png_const_structrp 1115 png_ptr)); 1116 #endif 1117 1118 #ifdef PNG_BUILD_GRAYSCALE_PALETTE_SUPPORTED 1119 PNG_EXPORT(35, void, png_build_grayscale_palette, (int bit_depth, 1120 png_colorp palette)); 1121 #endif 1122 1123 #ifdef PNG_READ_ALPHA_MODE_SUPPORTED 1124 /* How the alpha channel is interpreted - this affects how the color channels 1125 * of a PNG file are returned to the calling application when an alpha channel, 1126 * or a tRNS chunk in a palette file, is present. 1127 * 1128 * This has no effect on the way pixels are written into a PNG output 1129 * datastream. The color samples in a PNG datastream are never premultiplied 1130 * with the alpha samples. 1131 * 1132 * The default is to return data according to the PNG specification: the alpha 1133 * channel is a linear measure of the contribution of the pixel to the 1134 * corresponding composited pixel, and the color channels are unassociated 1135 * (not premultiplied). The gamma encoded color channels must be scaled 1136 * according to the contribution and to do this it is necessary to undo 1137 * the encoding, scale the color values, perform the composition and re-encode 1138 * the values. This is the 'PNG' mode. 1139 * 1140 * The alternative is to 'associate' the alpha with the color information by 1141 * storing color channel values that have been scaled by the alpha. 1142 * image. These are the 'STANDARD', 'ASSOCIATED' or 'PREMULTIPLIED' modes 1143 * (the latter being the two common names for associated alpha color channels). 1144 * 1145 * For the 'OPTIMIZED' mode, a pixel is treated as opaque only if the alpha 1146 * value is equal to the maximum value. 1147 * 1148 * The final choice is to gamma encode the alpha channel as well. This is 1149 * broken because, in practice, no implementation that uses this choice 1150 * correctly undoes the encoding before handling alpha composition. Use this 1151 * choice only if other serious errors in the software or hardware you use 1152 * mandate it; the typical serious error is for dark halos to appear around 1153 * opaque areas of the composited PNG image because of arithmetic overflow. 1154 * 1155 * The API function png_set_alpha_mode specifies which of these choices to use 1156 * with an enumerated 'mode' value and the gamma of the required output: 1157 */ 1158 #define PNG_ALPHA_PNG 0 /* according to the PNG standard */ 1159 #define PNG_ALPHA_STANDARD 1 /* according to Porter/Duff */ 1160 #define PNG_ALPHA_ASSOCIATED 1 /* as above; this is the normal practice */ 1161 #define PNG_ALPHA_PREMULTIPLIED 1 /* as above */ 1162 #define PNG_ALPHA_OPTIMIZED 2 /* 'PNG' for opaque pixels, else 'STANDARD' */ 1163 #define PNG_ALPHA_BROKEN 3 /* the alpha channel is gamma encoded */ 1164 1165 PNG_FP_EXPORT(227, void, png_set_alpha_mode, (png_structrp png_ptr, int mode, 1166 double output_gamma)) 1167 PNG_FIXED_EXPORT(228, void, png_set_alpha_mode_fixed, (png_structrp png_ptr, 1168 int mode, png_fixed_point output_gamma)) 1169 #endif 1170 1171 #if defined(PNG_GAMMA_SUPPORTED) || defined(PNG_READ_ALPHA_MODE_SUPPORTED) 1172 /* The output_gamma value is a screen gamma in libpng terminology: it expresses 1173 * how to decode the output values, not how they are encoded. 1174 */ 1175 #define PNG_DEFAULT_sRGB -1 /* sRGB gamma and color space */ 1176 #define PNG_GAMMA_MAC_18 -2 /* Old Mac '1.8' gamma and color space */ 1177 #define PNG_GAMMA_sRGB 220000 /* Television standards--matches sRGB gamma */ 1178 #define PNG_GAMMA_LINEAR PNG_FP_1 /* Linear */ 1179 #endif 1180 1181 /* The following are examples of calls to png_set_alpha_mode to achieve the 1182 * required overall gamma correction and, where necessary, alpha 1183 * premultiplication. 1184 * 1185 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB); 1186 * This is the default libpng handling of the alpha channel - it is not 1187 * pre-multiplied into the color components. In addition the call states 1188 * that the output is for a sRGB system and causes all PNG files without gAMA 1189 * chunks to be assumed to be encoded using sRGB. 1190 * 1191 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC); 1192 * In this case the output is assumed to be something like an sRGB conformant 1193 * display preceded by a power-law lookup table of power 1.45. This is how 1194 * early Mac systems behaved. 1195 * 1196 * png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_GAMMA_LINEAR); 1197 * This is the classic Jim Blinn approach and will work in academic 1198 * environments where everything is done by the book. It has the shortcoming 1199 * of assuming that input PNG data with no gamma information is linear - this 1200 * is unlikely to be correct unless the PNG files where generated locally. 1201 * Most of the time the output precision will be so low as to show 1202 * significant banding in dark areas of the image. 1203 * 1204 * png_set_expand_16(pp); 1205 * png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_DEFAULT_sRGB); 1206 * This is a somewhat more realistic Jim Blinn inspired approach. PNG files 1207 * are assumed to have the sRGB encoding if not marked with a gamma value and 1208 * the output is always 16 bits per component. This permits accurate scaling 1209 * and processing of the data. If you know that your input PNG files were 1210 * generated locally you might need to replace PNG_DEFAULT_sRGB with the 1211 * correct value for your system. 1212 * 1213 * png_set_alpha_mode(pp, PNG_ALPHA_OPTIMIZED, PNG_DEFAULT_sRGB); 1214 * If you just need to composite the PNG image onto an existing background 1215 * and if you control the code that does this you can use the optimization 1216 * setting. In this case you just copy completely opaque pixels to the 1217 * output. For pixels that are not completely transparent (you just skip 1218 * those) you do the composition math using png_composite or png_composite_16 1219 * below then encode the resultant 8-bit or 16-bit values to match the output 1220 * encoding. 1221 * 1222 * Other cases 1223 * If neither the PNG nor the standard linear encoding work for you because 1224 * of the software or hardware you use then you have a big problem. The PNG 1225 * case will probably result in halos around the image. The linear encoding 1226 * will probably result in a washed out, too bright, image (it's actually too 1227 * contrasty.) Try the ALPHA_OPTIMIZED mode above - this will probably 1228 * substantially reduce the halos. Alternatively try: 1229 * 1230 * png_set_alpha_mode(pp, PNG_ALPHA_BROKEN, PNG_DEFAULT_sRGB); 1231 * This option will also reduce the halos, but there will be slight dark 1232 * halos round the opaque parts of the image where the background is light. 1233 * In the OPTIMIZED mode the halos will be light halos where the background 1234 * is dark. Take your pick - the halos are unavoidable unless you can get 1235 * your hardware/software fixed! (The OPTIMIZED approach is slightly 1236 * faster.) 1237 * 1238 * When the default gamma of PNG files doesn't match the output gamma. 1239 * If you have PNG files with no gamma information png_set_alpha_mode allows 1240 * you to provide a default gamma, but it also sets the output gamma to the 1241 * matching value. If you know your PNG files have a gamma that doesn't 1242 * match the output you can take advantage of the fact that 1243 * png_set_alpha_mode always sets the output gamma but only sets the PNG 1244 * default if it is not already set: 1245 * 1246 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB); 1247 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC); 1248 * The first call sets both the default and the output gamma values, the 1249 * second call overrides the output gamma without changing the default. This 1250 * is easier than achieving the same effect with png_set_gamma. You must use 1251 * PNG_ALPHA_PNG for the first call - internal checking in png_set_alpha will 1252 * fire if more than one call to png_set_alpha_mode and png_set_background is 1253 * made in the same read operation, however multiple calls with PNG_ALPHA_PNG 1254 * are ignored. 1255 */ 1256 1257 #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED 1258 PNG_EXPORT(36, void, png_set_strip_alpha, (png_structrp png_ptr)); 1259 #endif 1260 1261 #if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \ 1262 defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED) 1263 PNG_EXPORT(37, void, png_set_swap_alpha, (png_structrp png_ptr)); 1264 #endif 1265 1266 #if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \ 1267 defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED) 1268 PNG_EXPORT(38, void, png_set_invert_alpha, (png_structrp png_ptr)); 1269 #endif 1270 1271 #if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED) 1272 /* Add a filler byte to 8-bit or 16-bit Gray or 24-bit or 48-bit RGB images. */ 1273 PNG_EXPORT(39, void, png_set_filler, (png_structrp png_ptr, png_uint_32 filler, 1274 int flags)); 1275 /* The values of the PNG_FILLER_ defines should NOT be changed */ 1276 # define PNG_FILLER_BEFORE 0 1277 # define PNG_FILLER_AFTER 1 1278 /* Add an alpha byte to 8-bit or 16-bit Gray or 24-bit or 48-bit RGB images. */ 1279 PNG_EXPORT(40, void, png_set_add_alpha, (png_structrp png_ptr, 1280 png_uint_32 filler, int flags)); 1281 #endif /* READ_FILLER || WRITE_FILLER */ 1282 1283 #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED) 1284 /* Swap bytes in 16-bit depth files. */ 1285 PNG_EXPORT(41, void, png_set_swap, (png_structrp png_ptr)); 1286 #endif 1287 1288 #if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED) 1289 /* Use 1 byte per pixel in 1, 2, or 4-bit depth files. */ 1290 PNG_EXPORT(42, void, png_set_packing, (png_structrp png_ptr)); 1291 #endif 1292 1293 #if defined(PNG_READ_PACKSWAP_SUPPORTED) || \ 1294 defined(PNG_WRITE_PACKSWAP_SUPPORTED) 1295 /* Swap packing order of pixels in bytes. */ 1296 PNG_EXPORT(43, void, png_set_packswap, (png_structrp png_ptr)); 1297 #endif 1298 1299 #if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED) 1300 /* Converts files to legal bit depths. */ 1301 PNG_EXPORT(44, void, png_set_shift, (png_structrp png_ptr, png_const_color_8p 1302 true_bits)); 1303 #endif 1304 1305 #if defined(PNG_READ_INTERLACING_SUPPORTED) || \ 1306 defined(PNG_WRITE_INTERLACING_SUPPORTED) 1307 /* Have the code handle the interlacing. Returns the number of passes. 1308 * MUST be called before png_read_update_info or png_start_read_image, 1309 * otherwise it will not have the desired effect. Note that it is still 1310 * necessary to call png_read_row or png_read_rows png_get_image_height 1311 * times for each pass. 1312 */ 1313 PNG_EXPORT(45, int, png_set_interlace_handling, (png_structrp png_ptr)); 1314 #endif 1315 1316 #if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED) 1317 /* Invert monochrome files */ 1318 PNG_EXPORT(46, void, png_set_invert_mono, (png_structrp png_ptr)); 1319 #endif 1320 1321 #ifdef PNG_READ_BACKGROUND_SUPPORTED 1322 /* Handle alpha and tRNS by replacing with a background color. Prior to 1323 * libpng-1.5.4 this API must not be called before the PNG file header has been 1324 * read. Doing so will result in unexpected behavior and possible warnings or 1325 * errors if the PNG file contains a bKGD chunk. 1326 */ 1327 PNG_FP_EXPORT(47, void, png_set_background, (png_structrp png_ptr, 1328 png_const_color_16p background_color, int background_gamma_code, 1329 int need_expand, double background_gamma)) 1330 PNG_FIXED_EXPORT(215, void, png_set_background_fixed, (png_structrp png_ptr, 1331 png_const_color_16p background_color, int background_gamma_code, 1332 int need_expand, png_fixed_point background_gamma)) 1333 #endif 1334 #ifdef PNG_READ_BACKGROUND_SUPPORTED 1335 # define PNG_BACKGROUND_GAMMA_UNKNOWN 0 1336 # define PNG_BACKGROUND_GAMMA_SCREEN 1 1337 # define PNG_BACKGROUND_GAMMA_FILE 2 1338 # define PNG_BACKGROUND_GAMMA_UNIQUE 3 1339 #endif 1340 1341 #ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED 1342 /* Scale a 16-bit depth file down to 8-bit, accurately. */ 1343 PNG_EXPORT(229, void, png_set_scale_16, (png_structrp png_ptr)); 1344 #endif 1345 1346 #ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED 1347 #define PNG_READ_16_TO_8_SUPPORTED /* Name prior to 1.5.4 */ 1348 /* Strip the second byte of information from a 16-bit depth file. */ 1349 PNG_EXPORT(48, void, png_set_strip_16, (png_structrp png_ptr)); 1350 #endif 1351 1352 #ifdef PNG_READ_QUANTIZE_SUPPORTED 1353 /* Turn on quantizing, and reduce the palette to the number of colors 1354 * available. 1355 */ 1356 PNG_EXPORT(49, void, png_set_quantize, (png_structrp png_ptr, 1357 png_colorp palette, int num_palette, int maximum_colors, 1358 png_const_uint_16p histogram, int full_quantize)); 1359 #endif 1360 1361 #ifdef PNG_READ_GAMMA_SUPPORTED 1362 /* The threshold on gamma processing is configurable but hard-wired into the 1363 * library. The following is the floating point variant. 1364 */ 1365 #define PNG_GAMMA_THRESHOLD (PNG_GAMMA_THRESHOLD_FIXED*.00001) 1366 1367 /* Handle gamma correction. Screen_gamma=(display_exponent). 1368 * NOTE: this API simply sets the screen and file gamma values. It will 1369 * therefore override the value for gamma in a PNG file if it is called after 1370 * the file header has been read - use with care - call before reading the PNG 1371 * file for best results! 1372 * 1373 * These routines accept the same gamma values as png_set_alpha_mode (described 1374 * above). The PNG_GAMMA_ defines and PNG_DEFAULT_sRGB can be passed to either 1375 * API (floating point or fixed.) Notice, however, that the 'file_gamma' value 1376 * is the inverse of a 'screen gamma' value. 1377 */ 1378 PNG_FP_EXPORT(50, void, png_set_gamma, (png_structrp png_ptr, 1379 double screen_gamma, double override_file_gamma)) 1380 PNG_FIXED_EXPORT(208, void, png_set_gamma_fixed, (png_structrp png_ptr, 1381 png_fixed_point screen_gamma, png_fixed_point override_file_gamma)) 1382 #endif 1383 1384 #ifdef PNG_WRITE_FLUSH_SUPPORTED 1385 /* Set how many lines between output flushes - 0 for no flushing */ 1386 PNG_EXPORT(51, void, png_set_flush, (png_structrp png_ptr, int nrows)); 1387 /* Flush the current PNG output buffer */ 1388 PNG_EXPORT(52, void, png_write_flush, (png_structrp png_ptr)); 1389 #endif 1390 1391 /* Optional update palette with requested transformations */ 1392 PNG_EXPORT(53, void, png_start_read_image, (png_structrp png_ptr)); 1393 1394 /* Optional call to update the users info structure */ 1395 PNG_EXPORT(54, void, png_read_update_info, (png_structrp png_ptr, 1396 png_inforp info_ptr)); 1397 1398 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED 1399 /* Read one or more rows of image data. */ 1400 PNG_EXPORT(55, void, png_read_rows, (png_structrp png_ptr, png_bytepp row, 1401 png_bytepp display_row, png_uint_32 num_rows)); 1402 #endif 1403 1404 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED 1405 /* Read a row of data. */ 1406 PNG_EXPORT(56, void, png_read_row, (png_structrp png_ptr, png_bytep row, 1407 png_bytep display_row)); 1408 #endif 1409 1410 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED 1411 /* Read the whole image into memory at once. */ 1412 PNG_EXPORT(57, void, png_read_image, (png_structrp png_ptr, png_bytepp image)); 1413 #endif 1414 1415 /* Write a row of image data */ 1416 PNG_EXPORT(58, void, png_write_row, (png_structrp png_ptr, 1417 png_const_bytep row)); 1418 1419 /* Write a few rows of image data: (*row) is not written; however, the type 1420 * is declared as writeable to maintain compatibility with previous versions 1421 * of libpng and to allow the 'display_row' array from read_rows to be passed 1422 * unchanged to write_rows. 1423 */ 1424 PNG_EXPORT(59, void, png_write_rows, (png_structrp png_ptr, png_bytepp row, 1425 png_uint_32 num_rows)); 1426 1427 /* Write the image data */ 1428 PNG_EXPORT(60, void, png_write_image, (png_structrp png_ptr, png_bytepp image)); 1429 1430 /* Write the end of the PNG file. */ 1431 PNG_EXPORT(61, void, png_write_end, (png_structrp png_ptr, 1432 png_inforp info_ptr)); 1433 1434 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED 1435 /* Read the end of the PNG file. */ 1436 PNG_EXPORT(62, void, png_read_end, (png_structrp png_ptr, png_inforp info_ptr)); 1437 #endif 1438 1439 /* Free any memory associated with the png_info_struct */ 1440 PNG_EXPORT(63, void, png_destroy_info_struct, (png_const_structrp png_ptr, 1441 png_infopp info_ptr_ptr)); 1442 1443 /* Free any memory associated with the png_struct and the png_info_structs */ 1444 PNG_EXPORT(64, void, png_destroy_read_struct, (png_structpp png_ptr_ptr, 1445 png_infopp info_ptr_ptr, png_infopp end_info_ptr_ptr)); 1446 1447 /* Free any memory associated with the png_struct and the png_info_structs */ 1448 PNG_EXPORT(65, void, png_destroy_write_struct, (png_structpp png_ptr_ptr, 1449 png_infopp info_ptr_ptr)); 1450 1451 /* Set the libpng method of handling chunk CRC errors */ 1452 PNG_EXPORT(66, void, png_set_crc_action, (png_structrp png_ptr, int crit_action, 1453 int ancil_action)); 1454 1455 /* Values for png_set_crc_action() say how to handle CRC errors in 1456 * ancillary and critical chunks, and whether to use the data contained 1457 * therein. Note that it is impossible to "discard" data in a critical 1458 * chunk. For versions prior to 0.90, the action was always error/quit, 1459 * whereas in version 0.90 and later, the action for CRC errors in ancillary 1460 * chunks is warn/discard. These values should NOT be changed. 1461 * 1462 * value action:critical action:ancillary 1463 */ 1464 #define PNG_CRC_DEFAULT 0 /* error/quit warn/discard data */ 1465 #define PNG_CRC_ERROR_QUIT 1 /* error/quit error/quit */ 1466 #define PNG_CRC_WARN_DISCARD 2 /* (INVALID) warn/discard data */ 1467 #define PNG_CRC_WARN_USE 3 /* warn/use data warn/use data */ 1468 #define PNG_CRC_QUIET_USE 4 /* quiet/use data quiet/use data */ 1469 #define PNG_CRC_NO_CHANGE 5 /* use current value use current value */ 1470 1471 #ifdef PNG_WRITE_SUPPORTED 1472 /* These functions give the user control over the scan-line filtering in 1473 * libpng and the compression methods used by zlib. These functions are 1474 * mainly useful for testing, as the defaults should work with most users. 1475 * Those users who are tight on memory or want faster performance at the 1476 * expense of compression can modify them. See the compression library 1477 * header file (zlib.h) for an explination of the compression functions. 1478 */ 1479 1480 /* Set the filtering method(s) used by libpng. Currently, the only valid 1481 * value for "method" is 0. 1482 */ 1483 PNG_EXPORT(67, void, png_set_filter, (png_structrp png_ptr, int method, 1484 int filters)); 1485 #endif /* WRITE */ 1486 1487 /* Flags for png_set_filter() to say which filters to use. The flags 1488 * are chosen so that they don't conflict with real filter types 1489 * below, in case they are supplied instead of the #defined constants. 1490 * These values should NOT be changed. 1491 */ 1492 #define PNG_NO_FILTERS 0x00 1493 #define PNG_FILTER_NONE 0x08 1494 #define PNG_FILTER_SUB 0x10 1495 #define PNG_FILTER_UP 0x20 1496 #define PNG_FILTER_AVG 0x40 1497 #define PNG_FILTER_PAETH 0x80 1498 #define PNG_FAST_FILTERS (PNG_FILTER_NONE | PNG_FILTER_SUB | PNG_FILTER_UP) 1499 #define PNG_ALL_FILTERS (PNG_FAST_FILTERS | PNG_FILTER_AVG | PNG_FILTER_PAETH) 1500 1501 /* Filter values (not flags) - used in pngwrite.c, pngwutil.c for now. 1502 * These defines should NOT be changed. 1503 */ 1504 #define PNG_FILTER_VALUE_NONE 0 1505 #define PNG_FILTER_VALUE_SUB 1 1506 #define PNG_FILTER_VALUE_UP 2 1507 #define PNG_FILTER_VALUE_AVG 3 1508 #define PNG_FILTER_VALUE_PAETH 4 1509 #define PNG_FILTER_VALUE_LAST 5 1510 1511 #ifdef PNG_WRITE_SUPPORTED 1512 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* DEPRECATED */ 1513 PNG_FP_EXPORT(68, void, png_set_filter_heuristics, (png_structrp png_ptr, 1514 int heuristic_method, int num_weights, png_const_doublep filter_weights, 1515 png_const_doublep filter_costs)) 1516 PNG_FIXED_EXPORT(209, void, png_set_filter_heuristics_fixed, 1517 (png_structrp png_ptr, int heuristic_method, int num_weights, 1518 png_const_fixed_point_p filter_weights, 1519 png_const_fixed_point_p filter_costs)) 1520 #endif /* WRITE_WEIGHTED_FILTER */ 1521 1522 /* The following are no longer used and will be removed from libpng-1.7: */ 1523 #define PNG_FILTER_HEURISTIC_DEFAULT 0 /* Currently "UNWEIGHTED" */ 1524 #define PNG_FILTER_HEURISTIC_UNWEIGHTED 1 /* Used by libpng < 0.95 */ 1525 #define PNG_FILTER_HEURISTIC_WEIGHTED 2 /* Experimental feature */ 1526 #define PNG_FILTER_HEURISTIC_LAST 3 /* Not a valid value */ 1527 1528 /* Set the library compression level. Currently, valid values range from 1529 * 0 - 9, corresponding directly to the zlib compression levels 0 - 9 1530 * (0 - no compression, 9 - "maximal" compression). Note that tests have 1531 * shown that zlib compression levels 3-6 usually perform as well as level 9 1532 * for PNG images, and do considerably fewer caclulations. In the future, 1533 * these values may not correspond directly to the zlib compression levels. 1534 */ 1535 #ifdef PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED 1536 PNG_EXPORT(69, void, png_set_compression_level, (png_structrp png_ptr, 1537 int level)); 1538 1539 PNG_EXPORT(70, void, png_set_compression_mem_level, (png_structrp png_ptr, 1540 int mem_level)); 1541 1542 PNG_EXPORT(71, void, png_set_compression_strategy, (png_structrp png_ptr, 1543 int strategy)); 1544 1545 /* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a 1546 * smaller value of window_bits if it can do so safely. 1547 */ 1548 PNG_EXPORT(72, void, png_set_compression_window_bits, (png_structrp png_ptr, 1549 int window_bits)); 1550 1551 PNG_EXPORT(73, void, png_set_compression_method, (png_structrp png_ptr, 1552 int method)); 1553 #endif /* WRITE_CUSTOMIZE_COMPRESSION */ 1554 1555 #ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED 1556 /* Also set zlib parameters for compressing non-IDAT chunks */ 1557 PNG_EXPORT(222, void, png_set_text_compression_level, (png_structrp png_ptr, 1558 int level)); 1559 1560 PNG_EXPORT(223, void, png_set_text_compression_mem_level, (png_structrp png_ptr, 1561 int mem_level)); 1562 1563 PNG_EXPORT(224, void, png_set_text_compression_strategy, (png_structrp png_ptr, 1564 int strategy)); 1565 1566 /* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a 1567 * smaller value of window_bits if it can do so safely. 1568 */ 1569 PNG_EXPORT(225, void, png_set_text_compression_window_bits, 1570 (png_structrp png_ptr, int window_bits)); 1571 1572 PNG_EXPORT(226, void, png_set_text_compression_method, (png_structrp png_ptr, 1573 int method)); 1574 #endif /* WRITE_CUSTOMIZE_ZTXT_COMPRESSION */ 1575 #endif /* WRITE */ 1576 1577 /* These next functions are called for input/output, memory, and error 1578 * handling. They are in the file pngrio.c, pngwio.c, and pngerror.c, 1579 * and call standard C I/O routines such as fread(), fwrite(), and 1580 * fprintf(). These functions can be made to use other I/O routines 1581 * at run time for those applications that need to handle I/O in a 1582 * different manner by calling png_set_???_fn(). See libpng-manual.txt for 1583 * more information. 1584 */ 1585 1586 #ifdef PNG_STDIO_SUPPORTED 1587 /* Initialize the input/output for the PNG file to the default functions. */ 1588 PNG_EXPORT(74, void, png_init_io, (png_structrp png_ptr, png_FILE_p fp)); 1589 #endif 1590 1591 /* Replace the (error and abort), and warning functions with user 1592 * supplied functions. If no messages are to be printed you must still 1593 * write and use replacement functions. The replacement error_fn should 1594 * still do a longjmp to the last setjmp location if you are using this 1595 * method of error handling. If error_fn or warning_fn is NULL, the 1596 * default function will be used. 1597 */ 1598 1599 PNG_EXPORT(75, void, png_set_error_fn, (png_structrp png_ptr, 1600 png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warning_fn)); 1601 1602 /* Return the user pointer associated with the error functions */ 1603 PNG_EXPORT(76, png_voidp, png_get_error_ptr, (png_const_structrp png_ptr)); 1604 1605 /* Replace the default data output functions with a user supplied one(s). 1606 * If buffered output is not used, then output_flush_fn can be set to NULL. 1607 * If PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile time 1608 * output_flush_fn will be ignored (and thus can be NULL). 1609 * It is probably a mistake to use NULL for output_flush_fn if 1610 * write_data_fn is not also NULL unless you have built libpng with 1611 * PNG_WRITE_FLUSH_SUPPORTED undefined, because in this case libpng's 1612 * default flush function, which uses the standard *FILE structure, will 1613 * be used. 1614 */ 1615 PNG_EXPORT(77, void, png_set_write_fn, (png_structrp png_ptr, png_voidp io_ptr, 1616 png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn)); 1617 1618 /* Replace the default data input function with a user supplied one. */ 1619 PNG_EXPORT(78, void, png_set_read_fn, (png_structrp png_ptr, png_voidp io_ptr, 1620 png_rw_ptr read_data_fn)); 1621 1622 /* Return the user pointer associated with the I/O functions */ 1623 PNG_EXPORT(79, png_voidp, png_get_io_ptr, (png_const_structrp png_ptr)); 1624 1625 PNG_EXPORT(80, void, png_set_read_status_fn, (png_structrp png_ptr, 1626 png_read_status_ptr read_row_fn)); 1627 1628 PNG_EXPORT(81, void, png_set_write_status_fn, (png_structrp png_ptr, 1629 png_write_status_ptr write_row_fn)); 1630 1631 #ifdef PNG_USER_MEM_SUPPORTED 1632 /* Replace the default memory allocation functions with user supplied one(s). */ 1633 PNG_EXPORT(82, void, png_set_mem_fn, (png_structrp png_ptr, png_voidp mem_ptr, 1634 png_malloc_ptr malloc_fn, png_free_ptr free_fn)); 1635 /* Return the user pointer associated with the memory functions */ 1636 PNG_EXPORT(83, png_voidp, png_get_mem_ptr, (png_const_structrp png_ptr)); 1637 #endif 1638 1639 #ifdef PNG_READ_USER_TRANSFORM_SUPPORTED 1640 PNG_EXPORT(84, void, png_set_read_user_transform_fn, (png_structrp png_ptr, 1641 png_user_transform_ptr read_user_transform_fn)); 1642 #endif 1643 1644 #ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED 1645 PNG_EXPORT(85, void, png_set_write_user_transform_fn, (png_structrp png_ptr, 1646 png_user_transform_ptr write_user_transform_fn)); 1647 #endif 1648 1649 #ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED 1650 PNG_EXPORT(86, void, png_set_user_transform_info, (png_structrp png_ptr, 1651 png_voidp user_transform_ptr, int user_transform_depth, 1652 int user_transform_channels)); 1653 /* Return the user pointer associated with the user transform functions */ 1654 PNG_EXPORT(87, png_voidp, png_get_user_transform_ptr, 1655 (png_const_structrp png_ptr)); 1656 #endif 1657 1658 #ifdef PNG_USER_TRANSFORM_INFO_SUPPORTED 1659 /* Return information about the row currently being processed. Note that these 1660 * APIs do not fail but will return unexpected results if called outside a user 1661 * transform callback. Also note that when transforming an interlaced image the 1662 * row number is the row number within the sub-image of the interlace pass, so 1663 * the value will increase to the height of the sub-image (not the full image) 1664 * then reset to 0 for the next pass. 1665 * 1666 * Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to 1667 * find the output pixel (x,y) given an interlaced sub-image pixel 1668 * (row,col,pass). (See below for these macros.) 1669 */ 1670 PNG_EXPORT(217, png_uint_32, png_get_current_row_number, (png_const_structrp)); 1671 PNG_EXPORT(218, png_byte, png_get_current_pass_number, (png_const_structrp)); 1672 #endif 1673 1674 #ifdef PNG_READ_USER_CHUNKS_SUPPORTED 1675 /* This callback is called only for *unknown* chunks. If 1676 * PNG_HANDLE_AS_UNKNOWN_SUPPORTED is set then it is possible to set known 1677 * chunks to be treated as unknown, however in this case the callback must do 1678 * any processing required by the chunk (e.g. by calling the appropriate 1679 * png_set_ APIs.) 1680 * 1681 * There is no write support - on write, by default, all the chunks in the 1682 * 'unknown' list are written in the specified position. 1683 * 1684 * The integer return from the callback function is interpreted thus: 1685 * 1686 * negative: An error occurred; png_chunk_error will be called. 1687 * zero: The chunk was not handled, the chunk will be saved. A critical 1688 * chunk will cause an error at this point unless it is to be saved. 1689 * positive: The chunk was handled, libpng will ignore/discard it. 1690 * 1691 * See "INTERACTION WITH USER CHUNK CALLBACKS" below for important notes about 1692 * how this behavior will change in libpng 1.7 1693 */ 1694 PNG_EXPORT(88, void, png_set_read_user_chunk_fn, (png_structrp png_ptr, 1695 png_voidp user_chunk_ptr, png_user_chunk_ptr read_user_chunk_fn)); 1696 #endif 1697 1698 #ifdef PNG_USER_CHUNKS_SUPPORTED 1699 PNG_EXPORT(89, png_voidp, png_get_user_chunk_ptr, (png_const_structrp png_ptr)); 1700 #endif 1701 1702 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED 1703 /* Sets the function callbacks for the push reader, and a pointer to a 1704 * user-defined structure available to the callback functions. 1705 */ 1706 PNG_EXPORT(90, void, png_set_progressive_read_fn, (png_structrp png_ptr, 1707 png_voidp progressive_ptr, png_progressive_info_ptr info_fn, 1708 png_progressive_row_ptr row_fn, png_progressive_end_ptr end_fn)); 1709 1710 /* Returns the user pointer associated with the push read functions */ 1711 PNG_EXPORT(91, png_voidp, png_get_progressive_ptr, 1712 (png_const_structrp png_ptr)); 1713 1714 /* Function to be called when data becomes available */ 1715 PNG_EXPORT(92, void, png_process_data, (png_structrp png_ptr, 1716 png_inforp info_ptr, png_bytep buffer, size_t buffer_size)); 1717 1718 /* A function which may be called *only* within png_process_data to stop the 1719 * processing of any more data. The function returns the number of bytes 1720 * remaining, excluding any that libpng has cached internally. A subsequent 1721 * call to png_process_data must supply these bytes again. If the argument 1722 * 'save' is set to true the routine will first save all the pending data and 1723 * will always return 0. 1724 */ 1725 PNG_EXPORT(219, size_t, png_process_data_pause, (png_structrp, int save)); 1726 1727 /* A function which may be called *only* outside (after) a call to 1728 * png_process_data. It returns the number of bytes of data to skip in the 1729 * input. Normally it will return 0, but if it returns a non-zero value the 1730 * application must skip than number of bytes of input data and pass the 1731 * following data to the next call to png_process_data. 1732 */ 1733 PNG_EXPORT(220, png_uint_32, png_process_data_skip, (png_structrp)); 1734 1735 /* Function that combines rows. 'new_row' is a flag that should come from 1736 * the callback and be non-NULL if anything needs to be done; the library 1737 * stores its own version of the new data internally and ignores the passed 1738 * in value. 1739 */ 1740 PNG_EXPORT(93, void, png_progressive_combine_row, (png_const_structrp png_ptr, 1741 png_bytep old_row, png_const_bytep new_row)); 1742 #endif /* PROGRESSIVE_READ */ 1743 1744 PNG_EXPORTA(94, png_voidp, png_malloc, (png_const_structrp png_ptr, 1745 png_alloc_size_t size), PNG_ALLOCATED); 1746 /* Added at libpng version 1.4.0 */ 1747 PNG_EXPORTA(95, png_voidp, png_calloc, (png_const_structrp png_ptr, 1748 png_alloc_size_t size), PNG_ALLOCATED); 1749 1750 /* Added at libpng version 1.2.4 */ 1751 PNG_EXPORTA(96, png_voidp, png_malloc_warn, (png_const_structrp png_ptr, 1752 png_alloc_size_t size), PNG_ALLOCATED); 1753 1754 /* Frees a pointer allocated by png_malloc() */ 1755 PNG_EXPORT(97, void, png_free, (png_const_structrp png_ptr, png_voidp ptr)); 1756 1757 /* Free data that was allocated internally */ 1758 PNG_EXPORT(98, void, png_free_data, (png_const_structrp png_ptr, 1759 png_inforp info_ptr, png_uint_32 free_me, int num)); 1760 1761 /* Reassign responsibility for freeing existing data, whether allocated 1762 * by libpng or by the application; this works on the png_info structure passed 1763 * in, it does not change the state for other png_info structures. 1764 * 1765 * It is unlikely that this function works correctly as of 1.6.0 and using it 1766 * may result either in memory leaks or double free of allocated data. 1767 */ 1768 PNG_EXPORT(99, void, png_data_freer, (png_const_structrp png_ptr, 1769 png_inforp info_ptr, int freer, png_uint_32 mask)); 1770 1771 /* Assignments for png_data_freer */ 1772 #define PNG_DESTROY_WILL_FREE_DATA 1 1773 #define PNG_SET_WILL_FREE_DATA 1 1774 #define PNG_USER_WILL_FREE_DATA 2 1775 /* Flags for png_ptr->free_me and info_ptr->free_me */ 1776 #define PNG_FREE_HIST 0x0008U 1777 #define PNG_FREE_ICCP 0x0010U 1778 #define PNG_FREE_SPLT 0x0020U 1779 #define PNG_FREE_ROWS 0x0040U 1780 #define PNG_FREE_PCAL 0x0080U 1781 #define PNG_FREE_SCAL 0x0100U 1782 #ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED 1783 # define PNG_FREE_UNKN 0x0200U 1784 #endif 1785 /* PNG_FREE_LIST 0x0400U removed in 1.6.0 because it is ignored */ 1786 #define PNG_FREE_PLTE 0x1000U 1787 #define PNG_FREE_TRNS 0x2000U 1788 #define PNG_FREE_TEXT 0x4000U 1789 #define PNG_FREE_EXIF 0x8000U /* Added at libpng-1.6.31 */ 1790 #define PNG_FREE_ALL 0xffffU 1791 #define PNG_FREE_MUL 0x4220U /* PNG_FREE_SPLT|PNG_FREE_TEXT|PNG_FREE_UNKN */ 1792 1793 #ifdef PNG_USER_MEM_SUPPORTED 1794 PNG_EXPORTA(100, png_voidp, png_malloc_default, (png_const_structrp png_ptr, 1795 png_alloc_size_t size), PNG_ALLOCATED PNG_DEPRECATED); 1796 PNG_EXPORTA(101, void, png_free_default, (png_const_structrp png_ptr, 1797 png_voidp ptr), PNG_DEPRECATED); 1798 #endif 1799 1800 #ifdef PNG_ERROR_TEXT_SUPPORTED 1801 /* Fatal error in PNG image of libpng - can't continue */ 1802 PNG_EXPORTA(102, void, png_error, (png_const_structrp png_ptr, 1803 png_const_charp error_message), PNG_NORETURN); 1804 1805 /* The same, but the chunk name is prepended to the error string. */ 1806 PNG_EXPORTA(103, void, png_chunk_error, (png_const_structrp png_ptr, 1807 png_const_charp error_message), PNG_NORETURN); 1808 1809 #else 1810 /* Fatal error in PNG image of libpng - can't continue */ 1811 PNG_EXPORTA(104, void, png_err, (png_const_structrp png_ptr), PNG_NORETURN); 1812 # define png_error(s1,s2) png_err(s1) 1813 # define png_chunk_error(s1,s2) png_err(s1) 1814 #endif 1815 1816 #ifdef PNG_WARNINGS_SUPPORTED 1817 /* Non-fatal error in libpng. Can continue, but may have a problem. */ 1818 PNG_EXPORT(105, void, png_warning, (png_const_structrp png_ptr, 1819 png_const_charp warning_message)); 1820 1821 /* Non-fatal error in libpng, chunk name is prepended to message. */ 1822 PNG_EXPORT(106, void, png_chunk_warning, (png_const_structrp png_ptr, 1823 png_const_charp warning_message)); 1824 #else 1825 # define png_warning(s1,s2) ((void)(s1)) 1826 # define png_chunk_warning(s1,s2) ((void)(s1)) 1827 #endif 1828 1829 #ifdef PNG_BENIGN_ERRORS_SUPPORTED 1830 /* Benign error in libpng. Can continue, but may have a problem. 1831 * User can choose whether to handle as a fatal error or as a warning. */ 1832 PNG_EXPORT(107, void, png_benign_error, (png_const_structrp png_ptr, 1833 png_const_charp warning_message)); 1834 1835 #ifdef PNG_READ_SUPPORTED 1836 /* Same, chunk name is prepended to message (only during read) */ 1837 PNG_EXPORT(108, void, png_chunk_benign_error, (png_const_structrp png_ptr, 1838 png_const_charp warning_message)); 1839 #endif 1840 1841 PNG_EXPORT(109, void, png_set_benign_errors, 1842 (png_structrp png_ptr, int allowed)); 1843 #else 1844 # ifdef PNG_ALLOW_BENIGN_ERRORS 1845 # define png_benign_error png_warning 1846 # define png_chunk_benign_error png_chunk_warning 1847 # else 1848 # define png_benign_error png_error 1849 # define png_chunk_benign_error png_chunk_error 1850 # endif 1851 #endif 1852 1853 /* The png_set_<chunk> functions are for storing values in the png_info_struct. 1854 * Similarly, the png_get_<chunk> calls are used to read values from the 1855 * png_info_struct, either storing the parameters in the passed variables, or 1856 * setting pointers into the png_info_struct where the data is stored. The 1857 * png_get_<chunk> functions return a non-zero value if the data was available 1858 * in info_ptr, or return zero and do not change any of the parameters if the 1859 * data was not available. 1860 * 1861 * These functions should be used instead of directly accessing png_info 1862 * to avoid problems with future changes in the size and internal layout of 1863 * png_info_struct. 1864 */ 1865 /* Returns "flag" if chunk data is valid in info_ptr. */ 1866 PNG_EXPORT(110, png_uint_32, png_get_valid, (png_const_structrp png_ptr, 1867 png_const_inforp info_ptr, png_uint_32 flag)); 1868 1869 /* Returns number of bytes needed to hold a transformed row. */ 1870 PNG_EXPORT(111, size_t, png_get_rowbytes, (png_const_structrp png_ptr, 1871 png_const_inforp info_ptr)); 1872 1873 #ifdef PNG_INFO_IMAGE_SUPPORTED 1874 /* Returns row_pointers, which is an array of pointers to scanlines that was 1875 * returned from png_read_png(). 1876 */ 1877 PNG_EXPORT(112, png_bytepp, png_get_rows, (png_const_structrp png_ptr, 1878 png_const_inforp info_ptr)); 1879 1880 /* Set row_pointers, which is an array of pointers to scanlines for use 1881 * by png_write_png(). 1882 */ 1883 PNG_EXPORT(113, void, png_set_rows, (png_const_structrp png_ptr, 1884 png_inforp info_ptr, png_bytepp row_pointers)); 1885 #endif 1886 1887 /* Returns number of color channels in image. */ 1888 PNG_EXPORT(114, png_byte, png_get_channels, (png_const_structrp png_ptr, 1889 png_const_inforp info_ptr)); 1890 1891 #ifdef PNG_EASY_ACCESS_SUPPORTED 1892 /* Returns image width in pixels. */ 1893 PNG_EXPORT(115, png_uint_32, png_get_image_width, (png_const_structrp png_ptr, 1894 png_const_inforp info_ptr)); 1895 1896 /* Returns image height in pixels. */ 1897 PNG_EXPORT(116, png_uint_32, png_get_image_height, (png_const_structrp png_ptr, 1898 png_const_inforp info_ptr)); 1899 1900 /* Returns image bit_depth. */ 1901 PNG_EXPORT(117, png_byte, png_get_bit_depth, (png_const_structrp png_ptr, 1902 png_const_inforp info_ptr)); 1903 1904 /* Returns image color_type. */ 1905 PNG_EXPORT(118, png_byte, png_get_color_type, (png_const_structrp png_ptr, 1906 png_const_inforp info_ptr)); 1907 1908 /* Returns image filter_type. */ 1909 PNG_EXPORT(119, png_byte, png_get_filter_type, (png_const_structrp png_ptr, 1910 png_const_inforp info_ptr)); 1911 1912 /* Returns image interlace_type. */ 1913 PNG_EXPORT(120, png_byte, png_get_interlace_type, (png_const_structrp png_ptr, 1914 png_const_inforp info_ptr)); 1915 1916 /* Returns image compression_type. */ 1917 PNG_EXPORT(121, png_byte, png_get_compression_type, (png_const_structrp png_ptr, 1918 png_const_inforp info_ptr)); 1919 1920 /* Returns image resolution in pixels per meter, from pHYs chunk data. */ 1921 PNG_EXPORT(122, png_uint_32, png_get_pixels_per_meter, 1922 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 1923 PNG_EXPORT(123, png_uint_32, png_get_x_pixels_per_meter, 1924 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 1925 PNG_EXPORT(124, png_uint_32, png_get_y_pixels_per_meter, 1926 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 1927 1928 /* Returns pixel aspect ratio, computed from pHYs chunk data. */ 1929 PNG_FP_EXPORT(125, float, png_get_pixel_aspect_ratio, 1930 (png_const_structrp png_ptr, png_const_inforp info_ptr)) 1931 PNG_FIXED_EXPORT(210, png_fixed_point, png_get_pixel_aspect_ratio_fixed, 1932 (png_const_structrp png_ptr, png_const_inforp info_ptr)) 1933 1934 /* Returns image x, y offset in pixels or microns, from oFFs chunk data. */ 1935 PNG_EXPORT(126, png_int_32, png_get_x_offset_pixels, 1936 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 1937 PNG_EXPORT(127, png_int_32, png_get_y_offset_pixels, 1938 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 1939 PNG_EXPORT(128, png_int_32, png_get_x_offset_microns, 1940 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 1941 PNG_EXPORT(129, png_int_32, png_get_y_offset_microns, 1942 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 1943 1944 #endif /* EASY_ACCESS */ 1945 1946 #ifdef PNG_READ_SUPPORTED 1947 /* Returns pointer to signature string read from PNG header */ 1948 PNG_EXPORT(130, png_const_bytep, png_get_signature, (png_const_structrp png_ptr, 1949 png_const_inforp info_ptr)); 1950 #endif 1951 1952 #ifdef PNG_bKGD_SUPPORTED 1953 PNG_EXPORT(131, png_uint_32, png_get_bKGD, (png_const_structrp png_ptr, 1954 png_inforp info_ptr, png_color_16p *background)); 1955 #endif 1956 1957 #ifdef PNG_bKGD_SUPPORTED 1958 PNG_EXPORT(132, void, png_set_bKGD, (png_const_structrp png_ptr, 1959 png_inforp info_ptr, png_const_color_16p background)); 1960 #endif 1961 1962 #ifdef PNG_cHRM_SUPPORTED 1963 PNG_FP_EXPORT(133, png_uint_32, png_get_cHRM, (png_const_structrp png_ptr, 1964 png_const_inforp info_ptr, double *white_x, double *white_y, double *red_x, 1965 double *red_y, double *green_x, double *green_y, double *blue_x, 1966 double *blue_y)) 1967 PNG_FP_EXPORT(230, png_uint_32, png_get_cHRM_XYZ, (png_const_structrp png_ptr, 1968 png_const_inforp info_ptr, double *red_X, double *red_Y, double *red_Z, 1969 double *green_X, double *green_Y, double *green_Z, double *blue_X, 1970 double *blue_Y, double *blue_Z)) 1971 PNG_FIXED_EXPORT(134, png_uint_32, png_get_cHRM_fixed, 1972 (png_const_structrp png_ptr, png_const_inforp info_ptr, 1973 png_fixed_point *int_white_x, png_fixed_point *int_white_y, 1974 png_fixed_point *int_red_x, png_fixed_point *int_red_y, 1975 png_fixed_point *int_green_x, png_fixed_point *int_green_y, 1976 png_fixed_point *int_blue_x, png_fixed_point *int_blue_y)) 1977 PNG_FIXED_EXPORT(231, png_uint_32, png_get_cHRM_XYZ_fixed, 1978 (png_const_structrp png_ptr, png_const_inforp info_ptr, 1979 png_fixed_point *int_red_X, png_fixed_point *int_red_Y, 1980 png_fixed_point *int_red_Z, png_fixed_point *int_green_X, 1981 png_fixed_point *int_green_Y, png_fixed_point *int_green_Z, 1982 png_fixed_point *int_blue_X, png_fixed_point *int_blue_Y, 1983 png_fixed_point *int_blue_Z)) 1984 #endif 1985 1986 #ifdef PNG_cHRM_SUPPORTED 1987 PNG_FP_EXPORT(135, void, png_set_cHRM, (png_const_structrp png_ptr, 1988 png_inforp info_ptr, 1989 double white_x, double white_y, double red_x, double red_y, double green_x, 1990 double green_y, double blue_x, double blue_y)) 1991 PNG_FP_EXPORT(232, void, png_set_cHRM_XYZ, (png_const_structrp png_ptr, 1992 png_inforp info_ptr, double red_X, double red_Y, double red_Z, 1993 double green_X, double green_Y, double green_Z, double blue_X, 1994 double blue_Y, double blue_Z)) 1995 PNG_FIXED_EXPORT(136, void, png_set_cHRM_fixed, (png_const_structrp png_ptr, 1996 png_inforp info_ptr, png_fixed_point int_white_x, 1997 png_fixed_point int_white_y, png_fixed_point int_red_x, 1998 png_fixed_point int_red_y, png_fixed_point int_green_x, 1999 png_fixed_point int_green_y, png_fixed_point int_blue_x, 2000 png_fixed_point int_blue_y)) 2001 PNG_FIXED_EXPORT(233, void, png_set_cHRM_XYZ_fixed, (png_const_structrp png_ptr, 2002 png_inforp info_ptr, png_fixed_point int_red_X, png_fixed_point int_red_Y, 2003 png_fixed_point int_red_Z, png_fixed_point int_green_X, 2004 png_fixed_point int_green_Y, png_fixed_point int_green_Z, 2005 png_fixed_point int_blue_X, png_fixed_point int_blue_Y, 2006 png_fixed_point int_blue_Z)) 2007 #endif 2008 2009 #ifdef PNG_eXIf_SUPPORTED 2010 PNG_EXPORT(246, png_uint_32, png_get_eXIf, (png_const_structrp png_ptr, 2011 png_inforp info_ptr, png_bytep *exif)); 2012 PNG_EXPORT(247, void, png_set_eXIf, (png_const_structrp png_ptr, 2013 png_inforp info_ptr, png_bytep exif)); 2014 2015 PNG_EXPORT(248, png_uint_32, png_get_eXIf_1, (png_const_structrp png_ptr, 2016 png_const_inforp info_ptr, png_uint_32 *num_exif, png_bytep *exif)); 2017 PNG_EXPORT(249, void, png_set_eXIf_1, (png_const_structrp png_ptr, 2018 png_inforp info_ptr, png_uint_32 num_exif, png_bytep exif)); 2019 #endif 2020 2021 #ifdef PNG_gAMA_SUPPORTED 2022 PNG_FP_EXPORT(137, png_uint_32, png_get_gAMA, (png_const_structrp png_ptr, 2023 png_const_inforp info_ptr, double *file_gamma)) 2024 PNG_FIXED_EXPORT(138, png_uint_32, png_get_gAMA_fixed, 2025 (png_const_structrp png_ptr, png_const_inforp info_ptr, 2026 png_fixed_point *int_file_gamma)) 2027 #endif 2028 2029 #ifdef PNG_gAMA_SUPPORTED 2030 PNG_FP_EXPORT(139, void, png_set_gAMA, (png_const_structrp png_ptr, 2031 png_inforp info_ptr, double file_gamma)) 2032 PNG_FIXED_EXPORT(140, void, png_set_gAMA_fixed, (png_const_structrp png_ptr, 2033 png_inforp info_ptr, png_fixed_point int_file_gamma)) 2034 #endif 2035 2036 #ifdef PNG_hIST_SUPPORTED 2037 PNG_EXPORT(141, png_uint_32, png_get_hIST, (png_const_structrp png_ptr, 2038 png_inforp info_ptr, png_uint_16p *hist)); 2039 PNG_EXPORT(142, void, png_set_hIST, (png_const_structrp png_ptr, 2040 png_inforp info_ptr, png_const_uint_16p hist)); 2041 #endif 2042 2043 PNG_EXPORT(143, png_uint_32, png_get_IHDR, (png_const_structrp png_ptr, 2044 png_const_inforp info_ptr, png_uint_32 *width, png_uint_32 *height, 2045 int *bit_depth, int *color_type, int *interlace_method, 2046 int *compression_method, int *filter_method)); 2047 2048 PNG_EXPORT(144, void, png_set_IHDR, (png_const_structrp png_ptr, 2049 png_inforp info_ptr, png_uint_32 width, png_uint_32 height, int bit_depth, 2050 int color_type, int interlace_method, int compression_method, 2051 int filter_method)); 2052 2053 #ifdef PNG_oFFs_SUPPORTED 2054 PNG_EXPORT(145, png_uint_32, png_get_oFFs, (png_const_structrp png_ptr, 2055 png_const_inforp info_ptr, png_int_32 *offset_x, png_int_32 *offset_y, 2056 int *unit_type)); 2057 #endif 2058 2059 #ifdef PNG_oFFs_SUPPORTED 2060 PNG_EXPORT(146, void, png_set_oFFs, (png_const_structrp png_ptr, 2061 png_inforp info_ptr, png_int_32 offset_x, png_int_32 offset_y, 2062 int unit_type)); 2063 #endif 2064 2065 #ifdef PNG_pCAL_SUPPORTED 2066 PNG_EXPORT(147, png_uint_32, png_get_pCAL, (png_const_structrp png_ptr, 2067 png_inforp info_ptr, png_charp *purpose, png_int_32 *X0, 2068 png_int_32 *X1, int *type, int *nparams, png_charp *units, 2069 png_charpp *params)); 2070 #endif 2071 2072 #ifdef PNG_pCAL_SUPPORTED 2073 PNG_EXPORT(148, void, png_set_pCAL, (png_const_structrp png_ptr, 2074 png_inforp info_ptr, png_const_charp purpose, png_int_32 X0, png_int_32 X1, 2075 int type, int nparams, png_const_charp units, png_charpp params)); 2076 #endif 2077 2078 #ifdef PNG_pHYs_SUPPORTED 2079 PNG_EXPORT(149, png_uint_32, png_get_pHYs, (png_const_structrp png_ptr, 2080 png_const_inforp info_ptr, png_uint_32 *res_x, png_uint_32 *res_y, 2081 int *unit_type)); 2082 #endif 2083 2084 #ifdef PNG_pHYs_SUPPORTED 2085 PNG_EXPORT(150, void, png_set_pHYs, (png_const_structrp png_ptr, 2086 png_inforp info_ptr, png_uint_32 res_x, png_uint_32 res_y, int unit_type)); 2087 #endif 2088 2089 PNG_EXPORT(151, png_uint_32, png_get_PLTE, (png_const_structrp png_ptr, 2090 png_inforp info_ptr, png_colorp *palette, int *num_palette)); 2091 2092 PNG_EXPORT(152, void, png_set_PLTE, (png_structrp png_ptr, 2093 png_inforp info_ptr, png_const_colorp palette, int num_palette)); 2094 2095 #ifdef PNG_sBIT_SUPPORTED 2096 PNG_EXPORT(153, png_uint_32, png_get_sBIT, (png_const_structrp png_ptr, 2097 png_inforp info_ptr, png_color_8p *sig_bit)); 2098 #endif 2099 2100 #ifdef PNG_sBIT_SUPPORTED 2101 PNG_EXPORT(154, void, png_set_sBIT, (png_const_structrp png_ptr, 2102 png_inforp info_ptr, png_const_color_8p sig_bit)); 2103 #endif 2104 2105 #ifdef PNG_sRGB_SUPPORTED 2106 PNG_EXPORT(155, png_uint_32, png_get_sRGB, (png_const_structrp png_ptr, 2107 png_const_inforp info_ptr, int *file_srgb_intent)); 2108 #endif 2109 2110 #ifdef PNG_sRGB_SUPPORTED 2111 PNG_EXPORT(156, void, png_set_sRGB, (png_const_structrp png_ptr, 2112 png_inforp info_ptr, int srgb_intent)); 2113 PNG_EXPORT(157, void, png_set_sRGB_gAMA_and_cHRM, (png_const_structrp png_ptr, 2114 png_inforp info_ptr, int srgb_intent)); 2115 #endif 2116 2117 #ifdef PNG_iCCP_SUPPORTED 2118 PNG_EXPORT(158, png_uint_32, png_get_iCCP, (png_const_structrp png_ptr, 2119 png_inforp info_ptr, png_charpp name, int *compression_type, 2120 png_bytepp profile, png_uint_32 *proflen)); 2121 #endif 2122 2123 #ifdef PNG_iCCP_SUPPORTED 2124 PNG_EXPORT(159, void, png_set_iCCP, (png_const_structrp png_ptr, 2125 png_inforp info_ptr, png_const_charp name, int compression_type, 2126 png_const_bytep profile, png_uint_32 proflen)); 2127 #endif 2128 2129 #ifdef PNG_sPLT_SUPPORTED 2130 PNG_EXPORT(160, int, png_get_sPLT, (png_const_structrp png_ptr, 2131 png_inforp info_ptr, png_sPLT_tpp entries)); 2132 #endif 2133 2134 #ifdef PNG_sPLT_SUPPORTED 2135 PNG_EXPORT(161, void, png_set_sPLT, (png_const_structrp png_ptr, 2136 png_inforp info_ptr, png_const_sPLT_tp entries, int nentries)); 2137 #endif 2138 2139 #ifdef PNG_TEXT_SUPPORTED 2140 /* png_get_text also returns the number of text chunks in *num_text */ 2141 PNG_EXPORT(162, int, png_get_text, (png_const_structrp png_ptr, 2142 png_inforp info_ptr, png_textp *text_ptr, int *num_text)); 2143 #endif 2144 2145 /* Note while png_set_text() will accept a structure whose text, 2146 * language, and translated keywords are NULL pointers, the structure 2147 * returned by png_get_text will always contain regular 2148 * zero-terminated C strings. They might be empty strings but 2149 * they will never be NULL pointers. 2150 */ 2151 2152 #ifdef PNG_TEXT_SUPPORTED 2153 PNG_EXPORT(163, void, png_set_text, (png_const_structrp png_ptr, 2154 png_inforp info_ptr, png_const_textp text_ptr, int num_text)); 2155 #endif 2156 2157 #ifdef PNG_tIME_SUPPORTED 2158 PNG_EXPORT(164, png_uint_32, png_get_tIME, (png_const_structrp png_ptr, 2159 png_inforp info_ptr, png_timep *mod_time)); 2160 #endif 2161 2162 #ifdef PNG_tIME_SUPPORTED 2163 PNG_EXPORT(165, void, png_set_tIME, (png_const_structrp png_ptr, 2164 png_inforp info_ptr, png_const_timep mod_time)); 2165 #endif 2166 2167 #ifdef PNG_tRNS_SUPPORTED 2168 PNG_EXPORT(166, png_uint_32, png_get_tRNS, (png_const_structrp png_ptr, 2169 png_inforp info_ptr, png_bytep *trans_alpha, int *num_trans, 2170 png_color_16p *trans_color)); 2171 #endif 2172 2173 #ifdef PNG_tRNS_SUPPORTED 2174 PNG_EXPORT(167, void, png_set_tRNS, (png_structrp png_ptr, 2175 png_inforp info_ptr, png_const_bytep trans_alpha, int num_trans, 2176 png_const_color_16p trans_color)); 2177 #endif 2178 2179 #ifdef PNG_sCAL_SUPPORTED 2180 PNG_FP_EXPORT(168, png_uint_32, png_get_sCAL, (png_const_structrp png_ptr, 2181 png_const_inforp info_ptr, int *unit, double *width, double *height)) 2182 #if defined(PNG_FLOATING_ARITHMETIC_SUPPORTED) || \ 2183 defined(PNG_FLOATING_POINT_SUPPORTED) 2184 /* NOTE: this API is currently implemented using floating point arithmetic, 2185 * consequently it can only be used on systems with floating point support. 2186 * In any case the range of values supported by png_fixed_point is small and it 2187 * is highly recommended that png_get_sCAL_s be used instead. 2188 */ 2189 PNG_FIXED_EXPORT(214, png_uint_32, png_get_sCAL_fixed, 2190 (png_const_structrp png_ptr, png_const_inforp info_ptr, int *unit, 2191 png_fixed_point *width, png_fixed_point *height)) 2192 #endif 2193 PNG_EXPORT(169, png_uint_32, png_get_sCAL_s, 2194 (png_const_structrp png_ptr, png_const_inforp info_ptr, int *unit, 2195 png_charpp swidth, png_charpp sheight)); 2196 2197 PNG_FP_EXPORT(170, void, png_set_sCAL, (png_const_structrp png_ptr, 2198 png_inforp info_ptr, int unit, double width, double height)) 2199 PNG_FIXED_EXPORT(213, void, png_set_sCAL_fixed, (png_const_structrp png_ptr, 2200 png_inforp info_ptr, int unit, png_fixed_point width, 2201 png_fixed_point height)) 2202 PNG_EXPORT(171, void, png_set_sCAL_s, (png_const_structrp png_ptr, 2203 png_inforp info_ptr, int unit, 2204 png_const_charp swidth, png_const_charp sheight)); 2205 #endif /* sCAL */ 2206 2207 #ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED 2208 /* Provide the default handling for all unknown chunks or, optionally, for 2209 * specific unknown chunks. 2210 * 2211 * NOTE: prior to 1.6.0 the handling specified for particular chunks on read was 2212 * ignored and the default was used, the per-chunk setting only had an effect on 2213 * write. If you wish to have chunk-specific handling on read in code that must 2214 * work on earlier versions you must use a user chunk callback to specify the 2215 * desired handling (keep or discard.) 2216 * 2217 * The 'keep' parameter is a PNG_HANDLE_CHUNK_ value as listed below. The 2218 * parameter is interpreted as follows: 2219 * 2220 * READ: 2221 * PNG_HANDLE_CHUNK_AS_DEFAULT: 2222 * Known chunks: do normal libpng processing, do not keep the chunk (but 2223 * see the comments below about PNG_HANDLE_AS_UNKNOWN_SUPPORTED) 2224 * Unknown chunks: for a specific chunk use the global default, when used 2225 * as the default discard the chunk data. 2226 * PNG_HANDLE_CHUNK_NEVER: 2227 * Discard the chunk data. 2228 * PNG_HANDLE_CHUNK_IF_SAFE: 2229 * Keep the chunk data if the chunk is not critical else raise a chunk 2230 * error. 2231 * PNG_HANDLE_CHUNK_ALWAYS: 2232 * Keep the chunk data. 2233 * 2234 * If the chunk data is saved it can be retrieved using png_get_unknown_chunks, 2235 * below. Notice that specifying "AS_DEFAULT" as a global default is equivalent 2236 * to specifying "NEVER", however when "AS_DEFAULT" is used for specific chunks 2237 * it simply resets the behavior to the libpng default. 2238 * 2239 * INTERACTION WITH USER CHUNK CALLBACKS: 2240 * The per-chunk handling is always used when there is a png_user_chunk_ptr 2241 * callback and the callback returns 0; the chunk is then always stored *unless* 2242 * it is critical and the per-chunk setting is other than ALWAYS. Notice that 2243 * the global default is *not* used in this case. (In effect the per-chunk 2244 * value is incremented to at least IF_SAFE.) 2245 * 2246 * IMPORTANT NOTE: this behavior will change in libpng 1.7 - the global and 2247 * per-chunk defaults will be honored. If you want to preserve the current 2248 * behavior when your callback returns 0 you must set PNG_HANDLE_CHUNK_IF_SAFE 2249 * as the default - if you don't do this libpng 1.6 will issue a warning. 2250 * 2251 * If you want unhandled unknown chunks to be discarded in libpng 1.6 and 2252 * earlier simply return '1' (handled). 2253 * 2254 * PNG_HANDLE_AS_UNKNOWN_SUPPORTED: 2255 * If this is *not* set known chunks will always be handled by libpng and 2256 * will never be stored in the unknown chunk list. Known chunks listed to 2257 * png_set_keep_unknown_chunks will have no effect. If it is set then known 2258 * chunks listed with a keep other than AS_DEFAULT will *never* be processed 2259 * by libpng, in addition critical chunks must either be processed by the 2260 * callback or saved. 2261 * 2262 * The IHDR and IEND chunks must not be listed. Because this turns off the 2263 * default handling for chunks that would otherwise be recognized the 2264 * behavior of libpng transformations may well become incorrect! 2265 * 2266 * WRITE: 2267 * When writing chunks the options only apply to the chunks specified by 2268 * png_set_unknown_chunks (below), libpng will *always* write known chunks 2269 * required by png_set_ calls and will always write the core critical chunks 2270 * (as required for PLTE). 2271 * 2272 * Each chunk in the png_set_unknown_chunks list is looked up in the 2273 * png_set_keep_unknown_chunks list to find the keep setting, this is then 2274 * interpreted as follows: 2275 * 2276 * PNG_HANDLE_CHUNK_AS_DEFAULT: 2277 * Write safe-to-copy chunks and write other chunks if the global 2278 * default is set to _ALWAYS, otherwise don't write this chunk. 2279 * PNG_HANDLE_CHUNK_NEVER: 2280 * Do not write the chunk. 2281 * PNG_HANDLE_CHUNK_IF_SAFE: 2282 * Write the chunk if it is safe-to-copy, otherwise do not write it. 2283 * PNG_HANDLE_CHUNK_ALWAYS: 2284 * Write the chunk. 2285 * 2286 * Note that the default behavior is effectively the opposite of the read case - 2287 * in read unknown chunks are not stored by default, in write they are written 2288 * by default. Also the behavior of PNG_HANDLE_CHUNK_IF_SAFE is very different 2289 * - on write the safe-to-copy bit is checked, on read the critical bit is 2290 * checked and on read if the chunk is critical an error will be raised. 2291 * 2292 * num_chunks: 2293 * =========== 2294 * If num_chunks is positive, then the "keep" parameter specifies the manner 2295 * for handling only those chunks appearing in the chunk_list array, 2296 * otherwise the chunk list array is ignored. 2297 * 2298 * If num_chunks is 0 the "keep" parameter specifies the default behavior for 2299 * unknown chunks, as described above. 2300 * 2301 * If num_chunks is negative, then the "keep" parameter specifies the manner 2302 * for handling all unknown chunks plus all chunks recognized by libpng 2303 * except for the IHDR, PLTE, tRNS, IDAT, and IEND chunks (which continue to 2304 * be processed by libpng. 2305 */ 2306 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED 2307 PNG_EXPORT(172, void, png_set_keep_unknown_chunks, (png_structrp png_ptr, 2308 int keep, png_const_bytep chunk_list, int num_chunks)); 2309 #endif /* HANDLE_AS_UNKNOWN */ 2310 2311 /* The "keep" PNG_HANDLE_CHUNK_ parameter for the specified chunk is returned; 2312 * the result is therefore true (non-zero) if special handling is required, 2313 * false for the default handling. 2314 */ 2315 PNG_EXPORT(173, int, png_handle_as_unknown, (png_const_structrp png_ptr, 2316 png_const_bytep chunk_name)); 2317 #endif /* SET_UNKNOWN_CHUNKS */ 2318 2319 #ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED 2320 PNG_EXPORT(174, void, png_set_unknown_chunks, (png_const_structrp png_ptr, 2321 png_inforp info_ptr, png_const_unknown_chunkp unknowns, 2322 int num_unknowns)); 2323 /* NOTE: prior to 1.6.0 this routine set the 'location' field of the added 2324 * unknowns to the location currently stored in the png_struct. This is 2325 * invariably the wrong value on write. To fix this call the following API 2326 * for each chunk in the list with the correct location. If you know your 2327 * code won't be compiled on earlier versions you can rely on 2328 * png_set_unknown_chunks(write-ptr, png_get_unknown_chunks(read-ptr)) doing 2329 * the correct thing. 2330 */ 2331 2332 PNG_EXPORT(175, void, png_set_unknown_chunk_location, 2333 (png_const_structrp png_ptr, png_inforp info_ptr, int chunk, int location)); 2334 2335 PNG_EXPORT(176, int, png_get_unknown_chunks, (png_const_structrp png_ptr, 2336 png_inforp info_ptr, png_unknown_chunkpp entries)); 2337 #endif 2338 2339 /* Png_free_data() will turn off the "valid" flag for anything it frees. 2340 * If you need to turn it off for a chunk that your application has freed, 2341 * you can use png_set_invalid(png_ptr, info_ptr, PNG_INFO_CHNK); 2342 */ 2343 PNG_EXPORT(177, void, png_set_invalid, (png_const_structrp png_ptr, 2344 png_inforp info_ptr, int mask)); 2345 2346 #ifdef PNG_INFO_IMAGE_SUPPORTED 2347 /* The "params" pointer is currently not used and is for future expansion. */ 2348 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED 2349 PNG_EXPORT(178, void, png_read_png, (png_structrp png_ptr, png_inforp info_ptr, 2350 int transforms, png_voidp params)); 2351 #endif 2352 #ifdef PNG_WRITE_SUPPORTED 2353 PNG_EXPORT(179, void, png_write_png, (png_structrp png_ptr, png_inforp info_ptr, 2354 int transforms, png_voidp params)); 2355 #endif 2356 #endif 2357 2358 PNG_EXPORT(180, png_const_charp, png_get_copyright, 2359 (png_const_structrp png_ptr)); 2360 PNG_EXPORT(181, png_const_charp, png_get_header_ver, 2361 (png_const_structrp png_ptr)); 2362 PNG_EXPORT(182, png_const_charp, png_get_header_version, 2363 (png_const_structrp png_ptr)); 2364 PNG_EXPORT(183, png_const_charp, png_get_libpng_ver, 2365 (png_const_structrp png_ptr)); 2366 2367 #ifdef PNG_MNG_FEATURES_SUPPORTED 2368 PNG_EXPORT(184, png_uint_32, png_permit_mng_features, (png_structrp png_ptr, 2369 png_uint_32 mng_features_permitted)); 2370 #endif 2371 2372 /* For use in png_set_keep_unknown, added to version 1.2.6 */ 2373 #define PNG_HANDLE_CHUNK_AS_DEFAULT 0 2374 #define PNG_HANDLE_CHUNK_NEVER 1 2375 #define PNG_HANDLE_CHUNK_IF_SAFE 2 2376 #define PNG_HANDLE_CHUNK_ALWAYS 3 2377 #define PNG_HANDLE_CHUNK_LAST 4 2378 2379 /* Strip the prepended error numbers ("#nnn ") from error and warning 2380 * messages before passing them to the error or warning handler. 2381 */ 2382 #ifdef PNG_ERROR_NUMBERS_SUPPORTED 2383 PNG_EXPORT(185, void, png_set_strip_error_numbers, (png_structrp png_ptr, 2384 png_uint_32 strip_mode)); 2385 #endif 2386 2387 /* Added in libpng-1.2.6 */ 2388 #ifdef PNG_SET_USER_LIMITS_SUPPORTED 2389 PNG_EXPORT(186, void, png_set_user_limits, (png_structrp png_ptr, 2390 png_uint_32 user_width_max, png_uint_32 user_height_max)); 2391 PNG_EXPORT(187, png_uint_32, png_get_user_width_max, 2392 (png_const_structrp png_ptr)); 2393 PNG_EXPORT(188, png_uint_32, png_get_user_height_max, 2394 (png_const_structrp png_ptr)); 2395 /* Added in libpng-1.4.0 */ 2396 PNG_EXPORT(189, void, png_set_chunk_cache_max, (png_structrp png_ptr, 2397 png_uint_32 user_chunk_cache_max)); 2398 PNG_EXPORT(190, png_uint_32, png_get_chunk_cache_max, 2399 (png_const_structrp png_ptr)); 2400 /* Added in libpng-1.4.1 */ 2401 PNG_EXPORT(191, void, png_set_chunk_malloc_max, (png_structrp png_ptr, 2402 png_alloc_size_t user_chunk_cache_max)); 2403 PNG_EXPORT(192, png_alloc_size_t, png_get_chunk_malloc_max, 2404 (png_const_structrp png_ptr)); 2405 #endif 2406 2407 #if defined(PNG_INCH_CONVERSIONS_SUPPORTED) 2408 PNG_EXPORT(193, png_uint_32, png_get_pixels_per_inch, 2409 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 2410 2411 PNG_EXPORT(194, png_uint_32, png_get_x_pixels_per_inch, 2412 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 2413 2414 PNG_EXPORT(195, png_uint_32, png_get_y_pixels_per_inch, 2415 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 2416 2417 PNG_FP_EXPORT(196, float, png_get_x_offset_inches, 2418 (png_const_structrp png_ptr, png_const_inforp info_ptr)) 2419 #ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */ 2420 PNG_FIXED_EXPORT(211, png_fixed_point, png_get_x_offset_inches_fixed, 2421 (png_const_structrp png_ptr, png_const_inforp info_ptr)) 2422 #endif 2423 2424 PNG_FP_EXPORT(197, float, png_get_y_offset_inches, (png_const_structrp png_ptr, 2425 png_const_inforp info_ptr)) 2426 #ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */ 2427 PNG_FIXED_EXPORT(212, png_fixed_point, png_get_y_offset_inches_fixed, 2428 (png_const_structrp png_ptr, png_const_inforp info_ptr)) 2429 #endif 2430 2431 # ifdef PNG_pHYs_SUPPORTED 2432 PNG_EXPORT(198, png_uint_32, png_get_pHYs_dpi, (png_const_structrp png_ptr, 2433 png_const_inforp info_ptr, png_uint_32 *res_x, png_uint_32 *res_y, 2434 int *unit_type)); 2435 # endif /* pHYs */ 2436 #endif /* INCH_CONVERSIONS */ 2437 2438 /* Added in libpng-1.4.0 */ 2439 #ifdef PNG_IO_STATE_SUPPORTED 2440 PNG_EXPORT(199, png_uint_32, png_get_io_state, (png_const_structrp png_ptr)); 2441 2442 /* Removed from libpng 1.6; use png_get_io_chunk_type. */ 2443 PNG_REMOVED(200, png_const_bytep, png_get_io_chunk_name, (png_structrp png_ptr), 2444 PNG_DEPRECATED) 2445 2446 PNG_EXPORT(216, png_uint_32, png_get_io_chunk_type, 2447 (png_const_structrp png_ptr)); 2448 2449 /* The flags returned by png_get_io_state() are the following: */ 2450 # define PNG_IO_NONE 0x0000 /* no I/O at this moment */ 2451 # define PNG_IO_READING 0x0001 /* currently reading */ 2452 # define PNG_IO_WRITING 0x0002 /* currently writing */ 2453 # define PNG_IO_SIGNATURE 0x0010 /* currently at the file signature */ 2454 # define PNG_IO_CHUNK_HDR 0x0020 /* currently at the chunk header */ 2455 # define PNG_IO_CHUNK_DATA 0x0040 /* currently at the chunk data */ 2456 # define PNG_IO_CHUNK_CRC 0x0080 /* currently at the chunk crc */ 2457 # define PNG_IO_MASK_OP 0x000f /* current operation: reading/writing */ 2458 # define PNG_IO_MASK_LOC 0x00f0 /* current location: sig/hdr/data/crc */ 2459 #endif /* IO_STATE */ 2460 2461 /* Interlace support. The following macros are always defined so that if 2462 * libpng interlace handling is turned off the macros may be used to handle 2463 * interlaced images within the application. 2464 */ 2465 #define PNG_INTERLACE_ADAM7_PASSES 7 2466 2467 /* Two macros to return the first row and first column of the original, 2468 * full, image which appears in a given pass. 'pass' is in the range 0 2469 * to 6 and the result is in the range 0 to 7. 2470 */ 2471 #define PNG_PASS_START_ROW(pass) (((1&~(pass))<<(3-((pass)>>1)))&7) 2472 #define PNG_PASS_START_COL(pass) (((1& (pass))<<(3-(((pass)+1)>>1)))&7) 2473 2474 /* A macro to return the offset between pixels in the output row for a pair of 2475 * pixels in the input - effectively the inverse of the 'COL_SHIFT' macro that 2476 * follows. Note that ROW_OFFSET is the offset from one row to the next whereas 2477 * COL_OFFSET is from one column to the next, within a row. 2478 */ 2479 #define PNG_PASS_ROW_OFFSET(pass) ((pass)>2?(8>>(((pass)-1)>>1)):8) 2480 #define PNG_PASS_COL_OFFSET(pass) (1<<((7-(pass))>>1)) 2481 2482 /* Two macros to help evaluate the number of rows or columns in each 2483 * pass. This is expressed as a shift - effectively log2 of the number or 2484 * rows or columns in each 8x8 tile of the original image. 2485 */ 2486 #define PNG_PASS_ROW_SHIFT(pass) ((pass)>2?(8-(pass))>>1:3) 2487 #define PNG_PASS_COL_SHIFT(pass) ((pass)>1?(7-(pass))>>1:3) 2488 2489 /* Hence two macros to determine the number of rows or columns in a given 2490 * pass of an image given its height or width. In fact these macros may 2491 * return non-zero even though the sub-image is empty, because the other 2492 * dimension may be empty for a small image. 2493 */ 2494 #define PNG_PASS_ROWS(height, pass) (((height)+(((1<<PNG_PASS_ROW_SHIFT(pass))\ 2495 -1)-PNG_PASS_START_ROW(pass)))>>PNG_PASS_ROW_SHIFT(pass)) 2496 #define PNG_PASS_COLS(width, pass) (((width)+(((1<<PNG_PASS_COL_SHIFT(pass))\ 2497 -1)-PNG_PASS_START_COL(pass)))>>PNG_PASS_COL_SHIFT(pass)) 2498 2499 /* For the reader row callbacks (both progressive and sequential) it is 2500 * necessary to find the row in the output image given a row in an interlaced 2501 * image, so two more macros: 2502 */ 2503 #define PNG_ROW_FROM_PASS_ROW(y_in, pass) \ 2504 (((y_in)<<PNG_PASS_ROW_SHIFT(pass))+PNG_PASS_START_ROW(pass)) 2505 #define PNG_COL_FROM_PASS_COL(x_in, pass) \ 2506 (((x_in)<<PNG_PASS_COL_SHIFT(pass))+PNG_PASS_START_COL(pass)) 2507 2508 /* Two macros which return a boolean (0 or 1) saying whether the given row 2509 * or column is in a particular pass. These use a common utility macro that 2510 * returns a mask for a given pass - the offset 'off' selects the row or 2511 * column version. The mask has the appropriate bit set for each column in 2512 * the tile. 2513 */ 2514 #define PNG_PASS_MASK(pass,off) ( \ 2515 ((0x110145AF>>(((7-(off))-(pass))<<2)) & 0xF) | \ 2516 ((0x01145AF0>>(((7-(off))-(pass))<<2)) & 0xF0)) 2517 2518 #define PNG_ROW_IN_INTERLACE_PASS(y, pass) \ 2519 ((PNG_PASS_MASK(pass,0) >> ((y)&7)) & 1) 2520 #define PNG_COL_IN_INTERLACE_PASS(x, pass) \ 2521 ((PNG_PASS_MASK(pass,1) >> ((x)&7)) & 1) 2522 2523 #ifdef PNG_READ_COMPOSITE_NODIV_SUPPORTED 2524 /* With these routines we avoid an integer divide, which will be slower on 2525 * most machines. However, it does take more operations than the corresponding 2526 * divide method, so it may be slower on a few RISC systems. There are two 2527 * shifts (by 8 or 16 bits) and an addition, versus a single integer divide. 2528 * 2529 * Note that the rounding factors are NOT supposed to be the same! 128 and 2530 * 32768 are correct for the NODIV code; 127 and 32767 are correct for the 2531 * standard method. 2532 * 2533 * [Optimized code by Greg Roelofs and Mark Adler...blame us for bugs. :-) ] 2534 */ 2535 2536 /* fg and bg should be in `gamma 1.0' space; alpha is the opacity */ 2537 2538 # define png_composite(composite, fg, alpha, bg) \ 2539 { \ 2540 png_uint_16 temp = (png_uint_16)((png_uint_16)(fg) \ 2541 * (png_uint_16)(alpha) \ 2542 + (png_uint_16)(bg)*(png_uint_16)(255 \ 2543 - (png_uint_16)(alpha)) + 128); \ 2544 (composite) = (png_byte)(((temp + (temp >> 8)) >> 8) & 0xff); \ 2545 } 2546 2547 # define png_composite_16(composite, fg, alpha, bg) \ 2548 { \ 2549 png_uint_32 temp = (png_uint_32)((png_uint_32)(fg) \ 2550 * (png_uint_32)(alpha) \ 2551 + (png_uint_32)(bg)*(65535 \ 2552 - (png_uint_32)(alpha)) + 32768); \ 2553 (composite) = (png_uint_16)(0xffff & ((temp + (temp >> 16)) >> 16)); \ 2554 } 2555 2556 #else /* Standard method using integer division */ 2557 2558 # define png_composite(composite, fg, alpha, bg) \ 2559 (composite) = \ 2560 (png_byte)(0xff & (((png_uint_16)(fg) * (png_uint_16)(alpha) + \ 2561 (png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) + \ 2562 127) / 255)) 2563 2564 # define png_composite_16(composite, fg, alpha, bg) \ 2565 (composite) = \ 2566 (png_uint_16)(0xffff & (((png_uint_32)(fg) * (png_uint_32)(alpha) + \ 2567 (png_uint_32)(bg)*(png_uint_32)(65535 - (png_uint_32)(alpha)) + \ 2568 32767) / 65535)) 2569 #endif /* READ_COMPOSITE_NODIV */ 2570 2571 #ifdef PNG_READ_INT_FUNCTIONS_SUPPORTED 2572 PNG_EXPORT(201, png_uint_32, png_get_uint_32, (png_const_bytep buf)); 2573 PNG_EXPORT(202, png_uint_16, png_get_uint_16, (png_const_bytep buf)); 2574 PNG_EXPORT(203, png_int_32, png_get_int_32, (png_const_bytep buf)); 2575 #endif 2576 2577 PNG_EXPORT(204, png_uint_32, png_get_uint_31, (png_const_structrp png_ptr, 2578 png_const_bytep buf)); 2579 /* No png_get_int_16 -- may be added if there's a real need for it. */ 2580 2581 /* Place a 32-bit number into a buffer in PNG byte order (big-endian). */ 2582 #ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED 2583 PNG_EXPORT(205, void, png_save_uint_32, (png_bytep buf, png_uint_32 i)); 2584 #endif 2585 #ifdef PNG_SAVE_INT_32_SUPPORTED 2586 PNG_EXPORT(206, void, png_save_int_32, (png_bytep buf, png_int_32 i)); 2587 #endif 2588 2589 /* Place a 16-bit number into a buffer in PNG byte order. 2590 * The parameter is declared unsigned int, not png_uint_16, 2591 * just to avoid potential problems on pre-ANSI C compilers. 2592 */ 2593 #ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED 2594 PNG_EXPORT(207, void, png_save_uint_16, (png_bytep buf, unsigned int i)); 2595 /* No png_save_int_16 -- may be added if there's a real need for it. */ 2596 #endif 2597 2598 #ifdef PNG_USE_READ_MACROS 2599 /* Inline macros to do direct reads of bytes from the input buffer. 2600 * The png_get_int_32() routine assumes we are using two's complement 2601 * format for negative values, which is almost certainly true. 2602 */ 2603 # define PNG_get_uint_32(buf) \ 2604 (((png_uint_32)(*(buf)) << 24) + \ 2605 ((png_uint_32)(*((buf) + 1)) << 16) + \ 2606 ((png_uint_32)(*((buf) + 2)) << 8) + \ 2607 ((png_uint_32)(*((buf) + 3)))) 2608 2609 /* From libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the 2610 * function) incorrectly returned a value of type png_uint_32. 2611 */ 2612 # define PNG_get_uint_16(buf) \ 2613 ((png_uint_16) \ 2614 (((unsigned int)(*(buf)) << 8) + \ 2615 ((unsigned int)(*((buf) + 1))))) 2616 2617 # define PNG_get_int_32(buf) \ 2618 ((png_int_32)((*(buf) & 0x80) \ 2619 ? -((png_int_32)(((png_get_uint_32(buf)^0xffffffffU)+1U)&0x7fffffffU)) \ 2620 : (png_int_32)png_get_uint_32(buf))) 2621 2622 /* If PNG_PREFIX is defined the same thing as below happens in pnglibconf.h, 2623 * but defining a macro name prefixed with PNG_PREFIX. 2624 */ 2625 # ifndef PNG_PREFIX 2626 # define png_get_uint_32(buf) PNG_get_uint_32(buf) 2627 # define png_get_uint_16(buf) PNG_get_uint_16(buf) 2628 # define png_get_int_32(buf) PNG_get_int_32(buf) 2629 # endif 2630 #else 2631 # ifdef PNG_PREFIX 2632 /* No macros; revert to the (redefined) function */ 2633 # define PNG_get_uint_32 (png_get_uint_32) 2634 # define PNG_get_uint_16 (png_get_uint_16) 2635 # define PNG_get_int_32 (png_get_int_32) 2636 # endif 2637 #endif 2638 2639 #ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED 2640 PNG_EXPORT(242, void, png_set_check_for_invalid_index, 2641 (png_structrp png_ptr, int allowed)); 2642 # ifdef PNG_GET_PALETTE_MAX_SUPPORTED 2643 PNG_EXPORT(243, int, png_get_palette_max, (png_const_structp png_ptr, 2644 png_const_infop info_ptr)); 2645 # endif 2646 #endif /* CHECK_FOR_INVALID_INDEX */ 2647 2648 /******************************************************************************* 2649 * Section 5: SIMPLIFIED API 2650 ******************************************************************************* 2651 * 2652 * Please read the documentation in libpng-manual.txt (TODO: write said 2653 * documentation) if you don't understand what follows. 2654 * 2655 * The simplified API hides the details of both libpng and the PNG file format 2656 * itself. It allows PNG files to be read into a very limited number of 2657 * in-memory bitmap formats or to be written from the same formats. If these 2658 * formats do not accommodate your needs then you can, and should, use the more 2659 * sophisticated APIs above - these support a wide variety of in-memory formats 2660 * and a wide variety of sophisticated transformations to those formats as well 2661 * as a wide variety of APIs to manipulate ancillary information. 2662 * 2663 * To read a PNG file using the simplified API: 2664 * 2665 * 1) Declare a 'png_image' structure (see below) on the stack, set the 2666 * version field to PNG_IMAGE_VERSION and the 'opaque' pointer to NULL 2667 * (this is REQUIRED, your program may crash if you don't do it.) 2668 * 2) Call the appropriate png_image_begin_read... function. 2669 * 3) Set the png_image 'format' member to the required sample format. 2670 * 4) Allocate a buffer for the image and, if required, the color-map. 2671 * 5) Call png_image_finish_read to read the image and, if required, the 2672 * color-map into your buffers. 2673 * 2674 * There are no restrictions on the format of the PNG input itself; all valid 2675 * color types, bit depths, and interlace methods are acceptable, and the 2676 * input image is transformed as necessary to the requested in-memory format 2677 * during the png_image_finish_read() step. The only caveat is that if you 2678 * request a color-mapped image from a PNG that is full-color or makes 2679 * complex use of an alpha channel the transformation is extremely lossy and the 2680 * result may look terrible. 2681 * 2682 * To write a PNG file using the simplified API: 2683 * 2684 * 1) Declare a 'png_image' structure on the stack and memset() it to all zero. 2685 * 2) Initialize the members of the structure that describe the image, setting 2686 * the 'format' member to the format of the image samples. 2687 * 3) Call the appropriate png_image_write... function with a pointer to the 2688 * image and, if necessary, the color-map to write the PNG data. 2689 * 2690 * png_image is a structure that describes the in-memory format of an image 2691 * when it is being read or defines the in-memory format of an image that you 2692 * need to write: 2693 */ 2694 #if defined(PNG_SIMPLIFIED_READ_SUPPORTED) || \ 2695 defined(PNG_SIMPLIFIED_WRITE_SUPPORTED) 2696 2697 #define PNG_IMAGE_VERSION 1 2698 2699 typedef struct png_control *png_controlp; 2700 typedef struct 2701 { 2702 png_controlp opaque; /* Initialize to NULL, free with png_image_free */ 2703 png_uint_32 version; /* Set to PNG_IMAGE_VERSION */ 2704 png_uint_32 width; /* Image width in pixels (columns) */ 2705 png_uint_32 height; /* Image height in pixels (rows) */ 2706 png_uint_32 format; /* Image format as defined below */ 2707 png_uint_32 flags; /* A bit mask containing informational flags */ 2708 png_uint_32 colormap_entries; 2709 /* Number of entries in the color-map */ 2710 2711 /* In the event of an error or warning the following field will be set to a 2712 * non-zero value and the 'message' field will contain a '\0' terminated 2713 * string with the libpng error or warning message. If both warnings and 2714 * an error were encountered, only the error is recorded. If there 2715 * are multiple warnings, only the first one is recorded. 2716 * 2717 * The upper 30 bits of this value are reserved, the low two bits contain 2718 * a value as follows: 2719 */ 2720 # define PNG_IMAGE_WARNING 1 2721 # define PNG_IMAGE_ERROR 2 2722 /* 2723 * The result is a two-bit code such that a value more than 1 indicates 2724 * a failure in the API just called: 2725 * 2726 * 0 - no warning or error 2727 * 1 - warning 2728 * 2 - error 2729 * 3 - error preceded by warning 2730 */ 2731 # define PNG_IMAGE_FAILED(png_cntrl) ((((png_cntrl).warning_or_error)&0x03)>1) 2732 2733 png_uint_32 warning_or_error; 2734 2735 char message[64]; 2736 } png_image, *png_imagep; 2737 2738 /* The samples of the image have one to four channels whose components have 2739 * original values in the range 0 to 1.0: 2740 * 2741 * 1: A single gray or luminance channel (G). 2742 * 2: A gray/luminance channel and an alpha channel (GA). 2743 * 3: Three red, green, blue color channels (RGB). 2744 * 4: Three color channels and an alpha channel (RGBA). 2745 * 2746 * The components are encoded in one of two ways: 2747 * 2748 * a) As a small integer, value 0..255, contained in a single byte. For the 2749 * alpha channel the original value is simply value/255. For the color or 2750 * luminance channels the value is encoded according to the sRGB specification 2751 * and matches the 8-bit format expected by typical display devices. 2752 * 2753 * The color/gray channels are not scaled (pre-multiplied) by the alpha 2754 * channel and are suitable for passing to color management software. 2755 * 2756 * b) As a value in the range 0..65535, contained in a 2-byte integer. All 2757 * channels can be converted to the original value by dividing by 65535; all 2758 * channels are linear. Color channels use the RGB encoding (RGB end-points) of 2759 * the sRGB specification. This encoding is identified by the 2760 * PNG_FORMAT_FLAG_LINEAR flag below. 2761 * 2762 * When the simplified API needs to convert between sRGB and linear colorspaces, 2763 * the actual sRGB transfer curve defined in the sRGB specification (see the 2764 * article at <https://en.wikipedia.org/wiki/SRGB>) is used, not the gamma=1/2.2 2765 * approximation used elsewhere in libpng. 2766 * 2767 * When an alpha channel is present it is expected to denote pixel coverage 2768 * of the color or luminance channels and is returned as an associated alpha 2769 * channel: the color/gray channels are scaled (pre-multiplied) by the alpha 2770 * value. 2771 * 2772 * The samples are either contained directly in the image data, between 1 and 8 2773 * bytes per pixel according to the encoding, or are held in a color-map indexed 2774 * by bytes in the image data. In the case of a color-map the color-map entries 2775 * are individual samples, encoded as above, and the image data has one byte per 2776 * pixel to select the relevant sample from the color-map. 2777 */ 2778 2779 /* PNG_FORMAT_* 2780 * 2781 * #defines to be used in png_image::format. Each #define identifies a 2782 * particular layout of sample data and, if present, alpha values. There are 2783 * separate defines for each of the two component encodings. 2784 * 2785 * A format is built up using single bit flag values. All combinations are 2786 * valid. Formats can be built up from the flag values or you can use one of 2787 * the predefined values below. When testing formats always use the FORMAT_FLAG 2788 * macros to test for individual features - future versions of the library may 2789 * add new flags. 2790 * 2791 * When reading or writing color-mapped images the format should be set to the 2792 * format of the entries in the color-map then png_image_{read,write}_colormap 2793 * called to read or write the color-map and set the format correctly for the 2794 * image data. Do not set the PNG_FORMAT_FLAG_COLORMAP bit directly! 2795 * 2796 * NOTE: libpng can be built with particular features disabled. If you see 2797 * compiler errors because the definition of one of the following flags has been 2798 * compiled out it is because libpng does not have the required support. It is 2799 * possible, however, for the libpng configuration to enable the format on just 2800 * read or just write; in that case you may see an error at run time. You can 2801 * guard against this by checking for the definition of the appropriate 2802 * "_SUPPORTED" macro, one of: 2803 * 2804 * PNG_SIMPLIFIED_{READ,WRITE}_{BGR,AFIRST}_SUPPORTED 2805 */ 2806 #define PNG_FORMAT_FLAG_ALPHA 0x01U /* format with an alpha channel */ 2807 #define PNG_FORMAT_FLAG_COLOR 0x02U /* color format: otherwise grayscale */ 2808 #define PNG_FORMAT_FLAG_LINEAR 0x04U /* 2-byte channels else 1-byte */ 2809 #define PNG_FORMAT_FLAG_COLORMAP 0x08U /* image data is color-mapped */ 2810 2811 #ifdef PNG_FORMAT_BGR_SUPPORTED 2812 # define PNG_FORMAT_FLAG_BGR 0x10U /* BGR colors, else order is RGB */ 2813 #endif 2814 2815 #ifdef PNG_FORMAT_AFIRST_SUPPORTED 2816 # define PNG_FORMAT_FLAG_AFIRST 0x20U /* alpha channel comes first */ 2817 #endif 2818 2819 #define PNG_FORMAT_FLAG_ASSOCIATED_ALPHA 0x40U /* alpha channel is associated */ 2820 2821 /* Commonly used formats have predefined macros. 2822 * 2823 * First the single byte (sRGB) formats: 2824 */ 2825 #define PNG_FORMAT_GRAY 0 2826 #define PNG_FORMAT_GA PNG_FORMAT_FLAG_ALPHA 2827 #define PNG_FORMAT_AG (PNG_FORMAT_GA|PNG_FORMAT_FLAG_AFIRST) 2828 #define PNG_FORMAT_RGB PNG_FORMAT_FLAG_COLOR 2829 #define PNG_FORMAT_BGR (PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_BGR) 2830 #define PNG_FORMAT_RGBA (PNG_FORMAT_RGB|PNG_FORMAT_FLAG_ALPHA) 2831 #define PNG_FORMAT_ARGB (PNG_FORMAT_RGBA|PNG_FORMAT_FLAG_AFIRST) 2832 #define PNG_FORMAT_BGRA (PNG_FORMAT_BGR|PNG_FORMAT_FLAG_ALPHA) 2833 #define PNG_FORMAT_ABGR (PNG_FORMAT_BGRA|PNG_FORMAT_FLAG_AFIRST) 2834 2835 /* Then the linear 2-byte formats. When naming these "Y" is used to 2836 * indicate a luminance (gray) channel. 2837 */ 2838 #define PNG_FORMAT_LINEAR_Y PNG_FORMAT_FLAG_LINEAR 2839 #define PNG_FORMAT_LINEAR_Y_ALPHA (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_ALPHA) 2840 #define PNG_FORMAT_LINEAR_RGB (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR) 2841 #define PNG_FORMAT_LINEAR_RGB_ALPHA \ 2842 (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_ALPHA) 2843 2844 /* With color-mapped formats the image data is one byte for each pixel, the byte 2845 * is an index into the color-map which is formatted as above. To obtain a 2846 * color-mapped format it is sufficient just to add the PNG_FOMAT_FLAG_COLORMAP 2847 * to one of the above definitions, or you can use one of the definitions below. 2848 */ 2849 #define PNG_FORMAT_RGB_COLORMAP (PNG_FORMAT_RGB|PNG_FORMAT_FLAG_COLORMAP) 2850 #define PNG_FORMAT_BGR_COLORMAP (PNG_FORMAT_BGR|PNG_FORMAT_FLAG_COLORMAP) 2851 #define PNG_FORMAT_RGBA_COLORMAP (PNG_FORMAT_RGBA|PNG_FORMAT_FLAG_COLORMAP) 2852 #define PNG_FORMAT_ARGB_COLORMAP (PNG_FORMAT_ARGB|PNG_FORMAT_FLAG_COLORMAP) 2853 #define PNG_FORMAT_BGRA_COLORMAP (PNG_FORMAT_BGRA|PNG_FORMAT_FLAG_COLORMAP) 2854 #define PNG_FORMAT_ABGR_COLORMAP (PNG_FORMAT_ABGR|PNG_FORMAT_FLAG_COLORMAP) 2855 2856 /* PNG_IMAGE macros 2857 * 2858 * These are convenience macros to derive information from a png_image 2859 * structure. The PNG_IMAGE_SAMPLE_ macros return values appropriate to the 2860 * actual image sample values - either the entries in the color-map or the 2861 * pixels in the image. The PNG_IMAGE_PIXEL_ macros return corresponding values 2862 * for the pixels and will always return 1 for color-mapped formats. The 2863 * remaining macros return information about the rows in the image and the 2864 * complete image. 2865 * 2866 * NOTE: All the macros that take a png_image::format parameter are compile time 2867 * constants if the format parameter is, itself, a constant. Therefore these 2868 * macros can be used in array declarations and case labels where required. 2869 * Similarly the macros are also pre-processor constants (sizeof is not used) so 2870 * they can be used in #if tests. 2871 * 2872 * First the information about the samples. 2873 */ 2874 #define PNG_IMAGE_SAMPLE_CHANNELS(fmt)\ 2875 (((fmt)&(PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_ALPHA))+1) 2876 /* Return the total number of channels in a given format: 1..4 */ 2877 2878 #define PNG_IMAGE_SAMPLE_COMPONENT_SIZE(fmt)\ 2879 ((((fmt) & PNG_FORMAT_FLAG_LINEAR) >> 2)+1) 2880 /* Return the size in bytes of a single component of a pixel or color-map 2881 * entry (as appropriate) in the image: 1 or 2. 2882 */ 2883 2884 #define PNG_IMAGE_SAMPLE_SIZE(fmt)\ 2885 (PNG_IMAGE_SAMPLE_CHANNELS(fmt) * PNG_IMAGE_SAMPLE_COMPONENT_SIZE(fmt)) 2886 /* This is the size of the sample data for one sample. If the image is 2887 * color-mapped it is the size of one color-map entry (and image pixels are 2888 * one byte in size), otherwise it is the size of one image pixel. 2889 */ 2890 2891 #define PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(fmt)\ 2892 (PNG_IMAGE_SAMPLE_CHANNELS(fmt) * 256) 2893 /* The maximum size of the color-map required by the format expressed in a 2894 * count of components. This can be used to compile-time allocate a 2895 * color-map: 2896 * 2897 * png_uint_16 colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(linear_fmt)]; 2898 * 2899 * png_byte colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(sRGB_fmt)]; 2900 * 2901 * Alternatively use the PNG_IMAGE_COLORMAP_SIZE macro below to use the 2902 * information from one of the png_image_begin_read_ APIs and dynamically 2903 * allocate the required memory. 2904 */ 2905 2906 /* Corresponding information about the pixels */ 2907 #define PNG_IMAGE_PIXEL_(test,fmt)\ 2908 (((fmt)&PNG_FORMAT_FLAG_COLORMAP)?1:test(fmt)) 2909 2910 #define PNG_IMAGE_PIXEL_CHANNELS(fmt)\ 2911 PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_CHANNELS,fmt) 2912 /* The number of separate channels (components) in a pixel; 1 for a 2913 * color-mapped image. 2914 */ 2915 2916 #define PNG_IMAGE_PIXEL_COMPONENT_SIZE(fmt)\ 2917 PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_COMPONENT_SIZE,fmt) 2918 /* The size, in bytes, of each component in a pixel; 1 for a color-mapped 2919 * image. 2920 */ 2921 2922 #define PNG_IMAGE_PIXEL_SIZE(fmt) PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_SIZE,fmt) 2923 /* The size, in bytes, of a complete pixel; 1 for a color-mapped image. */ 2924 2925 /* Information about the whole row, or whole image */ 2926 #define PNG_IMAGE_ROW_STRIDE(image)\ 2927 (PNG_IMAGE_PIXEL_CHANNELS((image).format) * (image).width) 2928 /* Return the total number of components in a single row of the image; this 2929 * is the minimum 'row stride', the minimum count of components between each 2930 * row. For a color-mapped image this is the minimum number of bytes in a 2931 * row. 2932 * 2933 * WARNING: this macro overflows for some images with more than one component 2934 * and very large image widths. libpng will refuse to process an image where 2935 * this macro would overflow. 2936 */ 2937 2938 #define PNG_IMAGE_BUFFER_SIZE(image, row_stride)\ 2939 (PNG_IMAGE_PIXEL_COMPONENT_SIZE((image).format)*(image).height*(row_stride)) 2940 /* Return the size, in bytes, of an image buffer given a png_image and a row 2941 * stride - the number of components to leave space for in each row. 2942 * 2943 * WARNING: this macro overflows a 32-bit integer for some large PNG images, 2944 * libpng will refuse to process an image where such an overflow would occur. 2945 */ 2946 2947 #define PNG_IMAGE_SIZE(image)\ 2948 PNG_IMAGE_BUFFER_SIZE(image, PNG_IMAGE_ROW_STRIDE(image)) 2949 /* Return the size, in bytes, of the image in memory given just a png_image; 2950 * the row stride is the minimum stride required for the image. 2951 */ 2952 2953 #define PNG_IMAGE_COLORMAP_SIZE(image)\ 2954 (PNG_IMAGE_SAMPLE_SIZE((image).format) * (image).colormap_entries) 2955 /* Return the size, in bytes, of the color-map of this image. If the image 2956 * format is not a color-map format this will return a size sufficient for 2957 * 256 entries in the given format; check PNG_FORMAT_FLAG_COLORMAP if 2958 * you don't want to allocate a color-map in this case. 2959 */ 2960 2961 /* PNG_IMAGE_FLAG_* 2962 * 2963 * Flags containing additional information about the image are held in the 2964 * 'flags' field of png_image. 2965 */ 2966 #define PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB 0x01 2967 /* This indicates that the RGB values of the in-memory bitmap do not 2968 * correspond to the red, green and blue end-points defined by sRGB. 2969 */ 2970 2971 #define PNG_IMAGE_FLAG_FAST 0x02 2972 /* On write emphasise speed over compression; the resultant PNG file will be 2973 * larger but will be produced significantly faster, particular for large 2974 * images. Do not use this option for images which will be distributed, only 2975 * used it when producing intermediate files that will be read back in 2976 * repeatedly. For a typical 24-bit image the option will double the read 2977 * speed at the cost of increasing the image size by 25%, however for many 2978 * more compressible images the PNG file can be 10 times larger with only a 2979 * slight speed gain. 2980 */ 2981 2982 #define PNG_IMAGE_FLAG_16BIT_sRGB 0x04 2983 /* On read if the image is a 16-bit per component image and there is no gAMA 2984 * or sRGB chunk assume that the components are sRGB encoded. Notice that 2985 * images output by the simplified API always have gamma information; setting 2986 * this flag only affects the interpretation of 16-bit images from an 2987 * external source. It is recommended that the application expose this flag 2988 * to the user; the user can normally easily recognize the difference between 2989 * linear and sRGB encoding. This flag has no effect on write - the data 2990 * passed to the write APIs must have the correct encoding (as defined 2991 * above.) 2992 * 2993 * If the flag is not set (the default) input 16-bit per component data is 2994 * assumed to be linear. 2995 * 2996 * NOTE: the flag can only be set after the png_image_begin_read_ call, 2997 * because that call initializes the 'flags' field. 2998 */ 2999 3000 #ifdef PNG_SIMPLIFIED_READ_SUPPORTED 3001 /* READ APIs 3002 * --------- 3003 * 3004 * The png_image passed to the read APIs must have been initialized by setting 3005 * the png_controlp field 'opaque' to NULL (or, safer, memset the whole thing.) 3006 */ 3007 #ifdef PNG_STDIO_SUPPORTED 3008 PNG_EXPORT(234, int, png_image_begin_read_from_file, (png_imagep image, 3009 const char *file_name)); 3010 /* The named file is opened for read and the image header is filled in 3011 * from the PNG header in the file. 3012 */ 3013 3014 PNG_EXPORT(235, int, png_image_begin_read_from_stdio, (png_imagep image, 3015 FILE* file)); 3016 /* The PNG header is read from the stdio FILE object. */ 3017 #endif /* STDIO */ 3018 3019 PNG_EXPORT(236, int, png_image_begin_read_from_memory, (png_imagep image, 3020 png_const_voidp memory, size_t size)); 3021 /* The PNG header is read from the given memory buffer. */ 3022 3023 PNG_EXPORT(237, int, png_image_finish_read, (png_imagep image, 3024 png_const_colorp background, void *buffer, png_int_32 row_stride, 3025 void *colormap)); 3026 /* Finish reading the image into the supplied buffer and clean up the 3027 * png_image structure. 3028 * 3029 * row_stride is the step, in byte or 2-byte units as appropriate, 3030 * between adjacent rows. A positive stride indicates that the top-most row 3031 * is first in the buffer - the normal top-down arrangement. A negative 3032 * stride indicates that the bottom-most row is first in the buffer. 3033 * 3034 * background need only be supplied if an alpha channel must be removed from 3035 * a png_byte format and the removal is to be done by compositing on a solid 3036 * color; otherwise it may be NULL and any composition will be done directly 3037 * onto the buffer. The value is an sRGB color to use for the background, 3038 * for grayscale output the green channel is used. 3039 * 3040 * background must be supplied when an alpha channel must be removed from a 3041 * single byte color-mapped output format, in other words if: 3042 * 3043 * 1) The original format from png_image_begin_read_from_* had 3044 * PNG_FORMAT_FLAG_ALPHA set. 3045 * 2) The format set by the application does not. 3046 * 3) The format set by the application has PNG_FORMAT_FLAG_COLORMAP set and 3047 * PNG_FORMAT_FLAG_LINEAR *not* set. 3048 * 3049 * For linear output removing the alpha channel is always done by compositing 3050 * on black and background is ignored. 3051 * 3052 * colormap must be supplied when PNG_FORMAT_FLAG_COLORMAP is set. It must 3053 * be at least the size (in bytes) returned by PNG_IMAGE_COLORMAP_SIZE. 3054 * image->colormap_entries will be updated to the actual number of entries 3055 * written to the colormap; this may be less than the original value. 3056 */ 3057 3058 PNG_EXPORT(238, void, png_image_free, (png_imagep image)); 3059 /* Free any data allocated by libpng in image->opaque, setting the pointer to 3060 * NULL. May be called at any time after the structure is initialized. 3061 */ 3062 #endif /* SIMPLIFIED_READ */ 3063 3064 #ifdef PNG_SIMPLIFIED_WRITE_SUPPORTED 3065 /* WRITE APIS 3066 * ---------- 3067 * For write you must initialize a png_image structure to describe the image to 3068 * be written. To do this use memset to set the whole structure to 0 then 3069 * initialize fields describing your image. 3070 * 3071 * version: must be set to PNG_IMAGE_VERSION 3072 * opaque: must be initialized to NULL 3073 * width: image width in pixels 3074 * height: image height in rows 3075 * format: the format of the data (image and color-map) you wish to write 3076 * flags: set to 0 unless one of the defined flags applies; set 3077 * PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB for color format images where the RGB 3078 * values do not correspond to the colors in sRGB. 3079 * colormap_entries: set to the number of entries in the color-map (0 to 256) 3080 */ 3081 #ifdef PNG_SIMPLIFIED_WRITE_STDIO_SUPPORTED 3082 PNG_EXPORT(239, int, png_image_write_to_file, (png_imagep image, 3083 const char *file, int convert_to_8bit, const void *buffer, 3084 png_int_32 row_stride, const void *colormap)); 3085 /* Write the image to the named file. */ 3086 3087 PNG_EXPORT(240, int, png_image_write_to_stdio, (png_imagep image, FILE *file, 3088 int convert_to_8_bit, const void *buffer, png_int_32 row_stride, 3089 const void *colormap)); 3090 /* Write the image to the given (FILE*). */ 3091 #endif /* SIMPLIFIED_WRITE_STDIO */ 3092 3093 /* With all write APIs if image is in one of the linear formats with 16-bit 3094 * data then setting convert_to_8_bit will cause the output to be an 8-bit PNG 3095 * gamma encoded according to the sRGB specification, otherwise a 16-bit linear 3096 * encoded PNG file is written. 3097 * 3098 * With color-mapped data formats the colormap parameter point to a color-map 3099 * with at least image->colormap_entries encoded in the specified format. If 3100 * the format is linear the written PNG color-map will be converted to sRGB 3101 * regardless of the convert_to_8_bit flag. 3102 * 3103 * With all APIs row_stride is handled as in the read APIs - it is the spacing 3104 * from one row to the next in component sized units (1 or 2 bytes) and if 3105 * negative indicates a bottom-up row layout in the buffer. If row_stride is 3106 * zero, libpng will calculate it for you from the image width and number of 3107 * channels. 3108 * 3109 * Note that the write API does not support interlacing, sub-8-bit pixels or 3110 * most ancillary chunks. If you need to write text chunks (e.g. for copyright 3111 * notices) you need to use one of the other APIs. 3112 */ 3113 3114 PNG_EXPORT(245, int, png_image_write_to_memory, (png_imagep image, void *memory, 3115 png_alloc_size_t * PNG_RESTRICT memory_bytes, int convert_to_8_bit, 3116 const void *buffer, png_int_32 row_stride, const void *colormap)); 3117 /* Write the image to the given memory buffer. The function both writes the 3118 * whole PNG data stream to *memory and updates *memory_bytes with the count 3119 * of bytes written. 3120 * 3121 * 'memory' may be NULL. In this case *memory_bytes is not read however on 3122 * success the number of bytes which would have been written will still be 3123 * stored in *memory_bytes. On failure *memory_bytes will contain 0. 3124 * 3125 * If 'memory' is not NULL it must point to memory[*memory_bytes] of 3126 * writeable memory. 3127 * 3128 * If the function returns success memory[*memory_bytes] (if 'memory' is not 3129 * NULL) contains the written PNG data. *memory_bytes will always be less 3130 * than or equal to the original value. 3131 * 3132 * If the function returns false and *memory_bytes was not changed an error 3133 * occurred during write. If *memory_bytes was changed, or is not 0 if 3134 * 'memory' was NULL, the write would have succeeded but for the memory 3135 * buffer being too small. *memory_bytes contains the required number of 3136 * bytes and will be bigger that the original value. 3137 */ 3138 3139 #define png_image_write_get_memory_size(image, size, convert_to_8_bit, buffer,\ 3140 row_stride, colormap)\ 3141 png_image_write_to_memory(&(image), 0, &(size), convert_to_8_bit, buffer,\ 3142 row_stride, colormap) 3143 /* Return the amount of memory in 'size' required to compress this image. 3144 * The png_image structure 'image' must be filled in as in the above 3145 * function and must not be changed before the actual write call, the buffer 3146 * and all other parameters must also be identical to that in the final 3147 * write call. The 'size' variable need not be initialized. 3148 * 3149 * NOTE: the macro returns true/false, if false is returned 'size' will be 3150 * set to zero and the write failed and probably will fail if tried again. 3151 */ 3152 3153 /* You can pre-allocate the buffer by making sure it is of sufficient size 3154 * regardless of the amount of compression achieved. The buffer size will 3155 * always be bigger than the original image and it will never be filled. The 3156 * following macros are provided to assist in allocating the buffer. 3157 */ 3158 #define PNG_IMAGE_DATA_SIZE(image) (PNG_IMAGE_SIZE(image)+(image).height) 3159 /* The number of uncompressed bytes in the PNG byte encoding of the image; 3160 * uncompressing the PNG IDAT data will give this number of bytes. 3161 * 3162 * NOTE: while PNG_IMAGE_SIZE cannot overflow for an image in memory this 3163 * macro can because of the extra bytes used in the PNG byte encoding. You 3164 * need to avoid this macro if your image size approaches 2^30 in width or 3165 * height. The same goes for the remainder of these macros; they all produce 3166 * bigger numbers than the actual in-memory image size. 3167 */ 3168 #ifndef PNG_ZLIB_MAX_SIZE 3169 # define PNG_ZLIB_MAX_SIZE(b) ((b)+(((b)+7U)>>3)+(((b)+63U)>>6)+11U) 3170 /* An upper bound on the number of compressed bytes given 'b' uncompressed 3171 * bytes. This is based on deflateBounds() in zlib; different 3172 * implementations of zlib compression may conceivably produce more data so 3173 * if your zlib implementation is not zlib itself redefine this macro 3174 * appropriately. 3175 */ 3176 #endif 3177 3178 #define PNG_IMAGE_COMPRESSED_SIZE_MAX(image)\ 3179 PNG_ZLIB_MAX_SIZE((png_alloc_size_t)PNG_IMAGE_DATA_SIZE(image)) 3180 /* An upper bound on the size of the data in the PNG IDAT chunks. */ 3181 3182 #define PNG_IMAGE_PNG_SIZE_MAX_(image, image_size)\ 3183 ((8U/*sig*/+25U/*IHDR*/+16U/*gAMA*/+44U/*cHRM*/+12U/*IEND*/+\ 3184 (((image).format&PNG_FORMAT_FLAG_COLORMAP)?/*colormap: PLTE, tRNS*/\ 3185 12U+3U*(image).colormap_entries/*PLTE data*/+\ 3186 (((image).format&PNG_FORMAT_FLAG_ALPHA)?\ 3187 12U/*tRNS*/+(image).colormap_entries:0U):0U)+\ 3188 12U)+(12U*((image_size)/PNG_ZBUF_SIZE))/*IDAT*/+(image_size)) 3189 /* A helper for the following macro; if your compiler cannot handle the 3190 * following macro use this one with the result of 3191 * PNG_IMAGE_COMPRESSED_SIZE_MAX(image) as the second argument (most 3192 * compilers should handle this just fine.) 3193 */ 3194 3195 #define PNG_IMAGE_PNG_SIZE_MAX(image)\ 3196 PNG_IMAGE_PNG_SIZE_MAX_(image, PNG_IMAGE_COMPRESSED_SIZE_MAX(image)) 3197 /* An upper bound on the total length of the PNG data stream for 'image'. 3198 * The result is of type png_alloc_size_t, on 32-bit systems this may 3199 * overflow even though PNG_IMAGE_DATA_SIZE does not overflow; the write will 3200 * run out of buffer space but return a corrected size which should work. 3201 */ 3202 #endif /* SIMPLIFIED_WRITE */ 3203 /******************************************************************************* 3204 * END OF SIMPLIFIED API 3205 ******************************************************************************/ 3206 #endif /* SIMPLIFIED_{READ|WRITE} */ 3207 3208 /******************************************************************************* 3209 * Section 6: IMPLEMENTATION OPTIONS 3210 ******************************************************************************* 3211 * 3212 * Support for arbitrary implementation-specific optimizations. The API allows 3213 * particular options to be turned on or off. 'Option' is the number of the 3214 * option and 'onoff' is 0 (off) or non-0 (on). The value returned is given 3215 * by the PNG_OPTION_ defines below. 3216 * 3217 * HARDWARE: normally hardware capabilities, such as the Intel SSE instructions, 3218 * are detected at run time, however sometimes it may be impossible 3219 * to do this in user mode, in which case it is necessary to discover 3220 * the capabilities in an OS specific way. Such capabilities are 3221 * listed here when libpng has support for them and must be turned 3222 * ON by the application if present. 3223 * 3224 * SOFTWARE: sometimes software optimizations actually result in performance 3225 * decrease on some architectures or systems, or with some sets of 3226 * PNG images. 'Software' options allow such optimizations to be 3227 * selected at run time. 3228 */ 3229 #ifdef PNG_SET_OPTION_SUPPORTED 3230 #ifdef PNG_ARM_NEON_API_SUPPORTED 3231 # define PNG_ARM_NEON 0 /* HARDWARE: ARM Neon SIMD instructions supported */ 3232 #endif 3233 #define PNG_MAXIMUM_INFLATE_WINDOW 2 /* SOFTWARE: force maximum window */ 3234 #define PNG_SKIP_sRGB_CHECK_PROFILE 4 /* SOFTWARE: Check ICC profile for sRGB */ 3235 #ifdef PNG_MIPS_MSA_API_SUPPORTED 3236 # define PNG_MIPS_MSA 6 /* HARDWARE: MIPS Msa SIMD instructions supported */ 3237 #endif 3238 #define PNG_IGNORE_ADLER32 8 3239 #ifdef PNG_POWERPC_VSX_API_SUPPORTED 3240 # define PNG_POWERPC_VSX 10 /* HARDWARE: PowerPC VSX SIMD instructions supported */ 3241 #endif 3242 #define PNG_OPTION_NEXT 12 /* Next option - numbers must be even */ 3243 3244 /* Return values: NOTE: there are four values and 'off' is *not* zero */ 3245 #define PNG_OPTION_UNSET 0 /* Unset - defaults to off */ 3246 #define PNG_OPTION_INVALID 1 /* Option number out of range */ 3247 #define PNG_OPTION_OFF 2 3248 #define PNG_OPTION_ON 3 3249 3250 PNG_EXPORT(244, int, png_set_option, (png_structrp png_ptr, int option, 3251 int onoff)); 3252 #endif /* SET_OPTION */ 3253 3254 /******************************************************************************* 3255 * END OF HARDWARE AND SOFTWARE OPTIONS 3256 ******************************************************************************/ 3257 3258 /* Maintainer: Put new public prototypes here ^, in libpng.3, in project 3259 * defs, and in scripts/symbols.def. 3260 */ 3261 3262 /* The last ordinal number (this is the *last* one already used; the next 3263 * one to use is one more than this.) 3264 */ 3265 #ifdef PNG_EXPORT_LAST_ORDINAL 3266 PNG_EXPORT_LAST_ORDINAL(249); 3267 #endif 3268 3269 #ifdef __cplusplus 3270 } 3271 #endif 3272 3273 #endif /* PNG_VERSION_INFO_ONLY */ 3274 /* Do not put anything past this line */ 3275 #endif /* PNG_H */