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 1.6.34, September 29, 2017 33 * 34 * Copyright (c) 1998-2002,2004,2006-2017 Glenn Randers-Pehrson 35 * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) 36 * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) 37 * 38 * This code is released under the libpng license (See LICENSE, below) 39 * 40 * Authors and maintainers: 41 * libpng versions 0.71, May 1995, through 0.88, January 1996: Guy Schalnat 42 * libpng versions 0.89, June 1996, through 0.96, May 1997: Andreas Dilger 43 * libpng versions 0.97, January 1998, through 1.6.34, September 29, 2017: 44 * Glenn Randers-Pehrson. 45 * See also "Contributing Authors", below. 46 */ 47 48 /* 49 * COPYRIGHT NOTICE, DISCLAIMER, and LICENSE: 50 * 51 * If you modify libpng you may insert additional notices immediately following 52 * this sentence. 53 * 54 * This code is released under the libpng license. 55 * 56 * libpng versions 1.0.7, July 1, 2000 through 1.6.34, September 29, 2017 are 57 * Copyright (c) 2000-2002, 2004, 2006-2017 Glenn Randers-Pehrson, are 58 * derived from libpng-1.0.6, and are distributed according to the same 59 * disclaimer and license as libpng-1.0.6 with the following individuals 60 * added to the list of Contributing Authors: 61 * 62 * Simon-Pierre Cadieux 63 * Eric S. Raymond 64 * Mans Rullgard 65 * Cosmin Truta 66 * Gilles Vollant 67 * James Yu 68 * Mandar Sahastrabuddhe 69 * Google Inc. 70 * Vadim Barkov 71 * 72 * and with the following additions to the disclaimer: 73 * 74 * There is no warranty against interference with your enjoyment of the 75 * library or against infringement. There is no warranty that our 76 * efforts or the library will fulfill any of your particular purposes 77 * or needs. This library is provided with all faults, and the entire 78 * risk of satisfactory quality, performance, accuracy, and effort is with 79 * the user. 80 * 81 * Some files in the "contrib" directory and some configure-generated 82 * files that are distributed with libpng have other copyright owners and 83 * are released under other open source licenses. 84 * 85 * libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are 86 * Copyright (c) 1998-2000 Glenn Randers-Pehrson, are derived from 87 * libpng-0.96, and are distributed according to the same disclaimer and 88 * license as libpng-0.96, with the following individuals added to the list 89 * of Contributing Authors: 90 * 91 * Tom Lane 92 * Glenn Randers-Pehrson 93 * Willem van Schaik 94 * 95 * libpng versions 0.89, June 1996, through 0.96, May 1997, are 96 * Copyright (c) 1996-1997 Andreas Dilger, are derived from libpng-0.88, 97 * and are distributed according to the same disclaimer and license as 98 * libpng-0.88, with the following individuals added to the list of 99 * Contributing Authors: 100 * 101 * John Bowler 102 * Kevin Bracey 103 * Sam Bushell 104 * Magnus Holmgren 105 * Greg Roelofs 106 * Tom Tanner 107 * 108 * Some files in the "scripts" directory have other copyright owners 109 * but are released under this license. 110 * 111 * libpng versions 0.5, May 1995, through 0.88, January 1996, are 112 * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc. 113 * 114 * For the purposes of this copyright and license, "Contributing Authors" 115 * is defined as the following set of individuals: 116 * 117 * Andreas Dilger 118 * Dave Martindale 119 * Guy Eric Schalnat 120 * Paul Schmidt 121 * Tim Wegner 122 * 123 * The PNG Reference Library is supplied "AS IS". The Contributing Authors 124 * and Group 42, Inc. disclaim all warranties, expressed or implied, 125 * including, without limitation, the warranties of merchantability and of 126 * fitness for any purpose. The Contributing Authors and Group 42, Inc. 127 * assume no liability for direct, indirect, incidental, special, exemplary, 128 * or consequential damages, which may result from the use of the PNG 129 * Reference Library, even if advised of the possibility of such damage. 130 * 131 * Permission is hereby granted to use, copy, modify, and distribute this 132 * source code, or portions hereof, for any purpose, without fee, subject 133 * to the following restrictions: 134 * 135 * 1. The origin of this source code must not be misrepresented. 136 * 137 * 2. Altered versions must be plainly marked as such and must not 138 * be misrepresented as being the original source. 139 * 140 * 3. This Copyright notice may not be removed or altered from any 141 * source or altered source distribution. 142 * 143 * The Contributing Authors and Group 42, Inc. specifically permit, without 144 * fee, and encourage the use of this source code as a component to 145 * supporting the PNG file format in commercial products. If you use this 146 * source code in a product, acknowledgment is not required but would be 147 * appreciated. 148 * 149 * END OF COPYRIGHT NOTICE, DISCLAIMER, and LICENSE. 150 * 151 * TRADEMARK: 152 * 153 * The name "libpng" has not been registered by the Copyright owner 154 * as a trademark in any jurisdiction. However, because libpng has 155 * been distributed and maintained world-wide, continually since 1995, 156 * the Copyright owner claims "common-law trademark protection" in any 157 * jurisdiction where common-law trademark is recognized. 158 * 159 * OSI CERTIFICATION: 160 * 161 * Libpng is OSI Certified Open Source Software. OSI Certified Open Source is 162 * a certification mark of the Open Source Initiative. OSI has not addressed 163 * the additional disclaimers inserted at version 1.0.7. 164 * 165 * EXPORT CONTROL: 166 * 167 * The Copyright owner believes that the Export Control Classification 168 * Number (ECCN) for libpng is EAR99, which means not subject to export 169 * controls or International Traffic in Arms Regulations (ITAR) because 170 * it is open source, publicly available software, that does not contain 171 * any encryption software. See the EAR, paragraphs 734.3(b)(3) and 172 * 734.7(b). 173 */ 174 175 /* 176 * A "png_get_copyright" function is available, for convenient use in "about" 177 * boxes and the like: 178 * 179 * printf("%s", png_get_copyright(NULL)); 180 * 181 * Also, the PNG logo (in PNG format, of course) is supplied in the 182 * files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31). 183 */ 184 185 /* 186 * The contributing authors would like to thank all those who helped 187 * with testing, bug fixes, and patience. This wouldn't have been 188 * possible without all of you. 189 * 190 * Thanks to Frank J. T. Wojcik for helping with the documentation. 191 */ 192 193 /* Note about libpng version numbers: 194 * 195 * Due to various miscommunications, unforeseen code incompatibilities 196 * and occasional factors outside the authors' control, version numbering 197 * on the library has not always been consistent and straightforward. 198 * The following table summarizes matters since version 0.89c, which was 199 * the first widely used release: 200 * 201 * source png.h png.h shared-lib 202 * version string int version 203 * ------- ------ ----- ---------- 204 * 0.89c "1.0 beta 3" 0.89 89 1.0.89 205 * 0.90 "1.0 beta 4" 0.90 90 0.90 [should have been 2.0.90] 206 * 0.95 "1.0 beta 5" 0.95 95 0.95 [should have been 2.0.95] 207 * 0.96 "1.0 beta 6" 0.96 96 0.96 [should have been 2.0.96] 208 * 0.97b "1.00.97 beta 7" 1.00.97 97 1.0.1 [should have been 2.0.97] 209 * 0.97c 0.97 97 2.0.97 210 * 0.98 0.98 98 2.0.98 211 * 0.99 0.99 98 2.0.99 212 * 0.99a-m 0.99 99 2.0.99 213 * 1.00 1.00 100 2.1.0 [100 should be 10000] 214 * 1.0.0 (from here on, the 100 2.1.0 [100 should be 10000] 215 * 1.0.1 png.h string is 10001 2.1.0 216 * 1.0.1a-e identical to the 10002 from here on, the shared library 217 * 1.0.2 source version) 10002 is 2.V where V is the source code 218 * 1.0.2a-b 10003 version, except as noted. 219 * 1.0.3 10003 220 * 1.0.3a-d 10004 221 * 1.0.4 10004 222 * 1.0.4a-f 10005 223 * 1.0.5 (+ 2 patches) 10005 224 * 1.0.5a-d 10006 225 * 1.0.5e-r 10100 (not source compatible) 226 * 1.0.5s-v 10006 (not binary compatible) 227 * 1.0.6 (+ 3 patches) 10006 (still binary incompatible) 228 * 1.0.6d-f 10007 (still binary incompatible) 229 * 1.0.6g 10007 230 * 1.0.6h 10007 10.6h (testing xy.z so-numbering) 231 * 1.0.6i 10007 10.6i 232 * 1.0.6j 10007 2.1.0.6j (incompatible with 1.0.0) 233 * 1.0.7beta11-14 DLLNUM 10007 2.1.0.7beta11-14 (binary compatible) 234 * 1.0.7beta15-18 1 10007 2.1.0.7beta15-18 (binary compatible) 235 * 1.0.7rc1-2 1 10007 2.1.0.7rc1-2 (binary compatible) 236 * 1.0.7 1 10007 (still compatible) 237 * ... 238 * 1.0.19 10 10019 10.so.0.19[.0] 239 * ... 240 * 1.2.59 13 10257 12.so.0.59[.0] 241 * ... 242 * 1.5.30 15 10527 15.so.15.30[.0] 243 * ... 244 * 1.6.34 16 10633 16.so.16.34[.0] 245 * 246 * Henceforth the source version will match the shared-library major 247 * and minor numbers; the shared-library major version number will be 248 * used for changes in backward compatibility, as it is intended. The 249 * PNG_LIBPNG_VER macro, which is not used within libpng but is available 250 * for applications, is an unsigned integer of the form xyyzz corresponding 251 * to the source version x.y.z (leading zeros in y and z). Beta versions 252 * were given the previous public release number plus a letter, until 253 * version 1.0.6j; from then on they were given the upcoming public 254 * release number plus "betaNN" or "rcNN". 255 * 256 * Binary incompatibility exists only when applications make direct access 257 * to the info_ptr or png_ptr members through png.h, and the compiled 258 * application is loaded with a different version of the library. 259 * 260 * DLLNUM will change each time there are forward or backward changes 261 * in binary compatibility (e.g., when a new feature is added). 262 * 263 * See libpng.txt or libpng.3 for more information. The PNG specification 264 * is available as a W3C Recommendation and as an ISO Specification, 265 * <https://www.w3.org/TR/2003/REC-PNG-20031110/ 266 */ 267 268 /* 269 * Y2K compliance in libpng: 270 * ========================= 271 * 272 * September 29, 2017 273 * 274 * Since the PNG Development group is an ad-hoc body, we can't make 275 * an official declaration. 276 * 277 * This is your unofficial assurance that libpng from version 0.71 and 278 * upward through 1.6.34 are Y2K compliant. It is my belief that 279 * earlier versions were also Y2K compliant. 280 * 281 * Libpng only has two year fields. One is a 2-byte unsigned integer 282 * that will hold years up to 65535. The other, which is deprecated, 283 * holds the date in text format, and will hold years up to 9999. 284 * 285 * The integer is 286 * "png_uint_16 year" in png_time_struct. 287 * 288 * The string is 289 * "char time_buffer[29]" in png_struct. This is no longer used 290 * in libpng-1.6.x and will be removed from libpng-1.7.0. 291 * 292 * There are seven time-related functions: 293 * png.c: png_convert_to_rfc_1123_buffer() in png.c 294 * (formerly png_convert_to_rfc_1123() prior to libpng-1.5.x and 295 * png_convert_to_rfc_1152() in error prior to libpng-0.98) 296 * png_convert_from_struct_tm() in pngwrite.c, called in pngwrite.c 297 * png_convert_from_time_t() in pngwrite.c 298 * png_get_tIME() in pngget.c 299 * png_handle_tIME() in pngrutil.c, called in pngread.c 300 * png_set_tIME() in pngset.c 301 * png_write_tIME() in pngwutil.c, called in pngwrite.c 302 * 303 * All handle dates properly in a Y2K environment. The 304 * png_convert_from_time_t() function calls gmtime() to convert from system 305 * clock time, which returns (year - 1900), which we properly convert to 306 * the full 4-digit year. There is a possibility that libpng applications 307 * are not passing 4-digit years into the png_convert_to_rfc_1123_buffer() 308 * function, or that they are incorrectly passing only a 2-digit year 309 * instead of "year - 1900" into the png_convert_from_struct_tm() function, 310 * but this is not under our control. The libpng documentation has always 311 * stated that it works with 4-digit years, and the APIs have been 312 * documented as such. 313 * 314 * The tIME chunk itself is also Y2K compliant. It uses a 2-byte unsigned 315 * integer to hold the year, and can hold years as large as 65535. 316 * 317 * zlib, upon which libpng depends, is also Y2K compliant. It contains 318 * no date-related code. 319 * 320 * Glenn Randers-Pehrson 321 * libpng maintainer 322 * PNG Development Group 323 */ 324 325 #ifndef PNG_H 326 #define PNG_H 327 328 /* This is not the place to learn how to use libpng. The file libpng-manual.txt 329 * describes how to use libpng, and the file example.c summarizes it 330 * with some code on which to build. This file is useful for looking 331 * at the actual function definitions and structure components. If that 332 * file has been stripped from your copy of libpng, you can find it at 333 * <http://www.libpng.org/pub/png/libpng-manual.txt> 334 * 335 * If you just need to read a PNG file and don't want to read the documentation 336 * skip to the end of this file and read the section entitled 'simplified API'. 337 */ 338 339 /* Version information for png.h - this should match the version in png.c */ 340 #define PNG_LIBPNG_VER_STRING "1.6.34" 341 #define PNG_HEADER_VERSION_STRING " libpng version 1.6.34 - September 29, 2017\n" 342 343 #define PNG_LIBPNG_VER_SONUM 16 344 #define PNG_LIBPNG_VER_DLLNUM 16 345 346 /* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */ 347 #define PNG_LIBPNG_VER_MAJOR 1 348 #define PNG_LIBPNG_VER_MINOR 6 349 #define PNG_LIBPNG_VER_RELEASE 34 350 351 /* This should match the numeric part of the final component of 352 * PNG_LIBPNG_VER_STRING, omitting any leading zero: 353 */ 354 355 #define PNG_LIBPNG_VER_BUILD 0 356 357 /* Release Status */ 358 #define PNG_LIBPNG_BUILD_ALPHA 1 359 #define PNG_LIBPNG_BUILD_BETA 2 360 #define PNG_LIBPNG_BUILD_RC 3 361 #define PNG_LIBPNG_BUILD_STABLE 4 362 #define PNG_LIBPNG_BUILD_RELEASE_STATUS_MASK 7 363 364 /* Release-Specific Flags */ 365 #define PNG_LIBPNG_BUILD_PATCH 8 /* Can be OR'ed with 366 PNG_LIBPNG_BUILD_STABLE only */ 367 #define PNG_LIBPNG_BUILD_PRIVATE 16 /* Cannot be OR'ed with 368 PNG_LIBPNG_BUILD_SPECIAL */ 369 #define PNG_LIBPNG_BUILD_SPECIAL 32 /* Cannot be OR'ed with 370 PNG_LIBPNG_BUILD_PRIVATE */ 371 372 #define PNG_LIBPNG_BUILD_BASE_TYPE PNG_LIBPNG_BUILD_STABLE 373 374 /* Careful here. At one time, Guy wanted to use 082, but that would be octal. 375 * We must not include leading zeros. 376 * Versions 0.7 through 1.0.0 were in the range 0 to 100 here (only 377 * version 1.0.0 was mis-numbered 100 instead of 10000). From 378 * version 1.0.1 it's xxyyzz, where x=major, y=minor, z=release 379 */ 380 #define PNG_LIBPNG_VER 10634 /* 1.6.34 */ 381 382 /* Library configuration: these options cannot be changed after 383 * the library has been built. 384 */ 385 #ifndef PNGLCONF_H 386 /* If pnglibconf.h is missing, you can 387 * copy scripts/pnglibconf.h.prebuilt to pnglibconf.h 388 */ 389 # include "pnglibconf.h" 390 #endif 391 392 #ifndef PNG_VERSION_INFO_ONLY 393 /* Machine specific configuration. */ 394 # include "pngconf.h" 395 #endif 396 397 /* 398 * Added at libpng-1.2.8 399 * 400 * Ref MSDN: Private as priority over Special 401 * VS_FF_PRIVATEBUILD File *was not* built using standard release 402 * procedures. If this value is given, the StringFileInfo block must 403 * contain a PrivateBuild string. 404 * 405 * VS_FF_SPECIALBUILD File *was* built by the original company using 406 * standard release procedures but is a variation of the standard 407 * file of the same version number. If this value is given, the 408 * StringFileInfo block must contain a SpecialBuild string. 409 */ 410 411 #ifdef PNG_USER_PRIVATEBUILD /* From pnglibconf.h */ 412 # define PNG_LIBPNG_BUILD_TYPE \ 413 (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_PRIVATE) 414 #else 415 # ifdef PNG_LIBPNG_SPECIALBUILD 416 # define PNG_LIBPNG_BUILD_TYPE \ 417 (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_SPECIAL) 418 # else 419 # define PNG_LIBPNG_BUILD_TYPE (PNG_LIBPNG_BUILD_BASE_TYPE) 420 # endif 421 #endif 422 423 #ifndef PNG_VERSION_INFO_ONLY 424 425 /* Inhibit C++ name-mangling for libpng functions but not for system calls. */ 426 #ifdef __cplusplus 427 extern "C" { 428 #endif /* __cplusplus */ 429 430 /* Version information for C files, stored in png.c. This had better match 431 * the version above. 432 */ 433 #define png_libpng_ver png_get_header_ver(NULL) 434 435 /* This file is arranged in several sections: 436 * 437 * 1. [omitted] 438 * 2. Any configuration options that can be specified by for the application 439 * code when it is built. (Build time configuration is in pnglibconf.h) 440 * 3. Type definitions (base types are defined in pngconf.h), structure 441 * definitions. 442 * 4. Exported library functions. 443 * 5. Simplified API. 444 * 6. Implementation options. 445 * 446 * The library source code has additional files (principally pngpriv.h) that 447 * allow configuration of the library. 448 */ 449 450 /* Section 1: [omitted] */ 451 452 /* Section 2: run time configuration 453 * See pnglibconf.h for build time configuration 454 * 455 * Run time configuration allows the application to choose between 456 * implementations of certain arithmetic APIs. The default is set 457 * at build time and recorded in pnglibconf.h, but it is safe to 458 * override these (and only these) settings. Note that this won't 459 * change what the library does, only application code, and the 460 * settings can (and probably should) be made on a per-file basis 461 * by setting the #defines before including png.h 462 * 463 * Use macros to read integers from PNG data or use the exported 464 * functions? 465 * PNG_USE_READ_MACROS: use the macros (see below) Note that 466 * the macros evaluate their argument multiple times. 467 * PNG_NO_USE_READ_MACROS: call the relevant library function. 468 * 469 * Use the alternative algorithm for compositing alpha samples that 470 * does not use division? 471 * PNG_READ_COMPOSITE_NODIV_SUPPORTED: use the 'no division' 472 * algorithm. 473 * PNG_NO_READ_COMPOSITE_NODIV: use the 'division' algorithm. 474 * 475 * How to handle benign errors if PNG_ALLOW_BENIGN_ERRORS is 476 * false? 477 * PNG_ALLOW_BENIGN_ERRORS: map calls to the benign error 478 * APIs to png_warning. 479 * Otherwise the calls are mapped to png_error. 480 */ 481 482 /* Section 3: type definitions, including structures and compile time 483 * constants. 484 * See pngconf.h for base types that vary by machine/system 485 */ 486 487 /* This triggers a compiler error in png.c, if png.c and png.h 488 * do not agree upon the version number. 489 */ 490 typedef char* png_libpng_version_1_6_34; 491 492 /* Basic control structions. Read libpng-manual.txt or libpng.3 for more info. 493 * 494 * png_struct is the cache of information used while reading or writing a single 495 * PNG file. One of these is always required, although the simplified API 496 * (below) hides the creation and destruction of it. 497 */ 498 typedef struct png_struct_def png_struct; 499 typedef const png_struct * png_const_structp; 500 typedef png_struct * png_structp; 501 typedef png_struct * * png_structpp; 502 503 /* png_info contains information read from or to be written to a PNG file. One 504 * or more of these must exist while reading or creating a PNG file. The 505 * information is not used by libpng during read but is used to control what 506 * gets written when a PNG file is created. "png_get_" function calls read 507 * information during read and "png_set_" functions calls write information 508 * when creating a PNG. 509 * been moved into a separate header file that is not accessible to 510 * applications. Read libpng-manual.txt or libpng.3 for more info. 511 */ 512 typedef struct png_info_def png_info; 513 typedef png_info * png_infop; 514 typedef const png_info * png_const_infop; 515 typedef png_info * * png_infopp; 516 517 /* Types with names ending 'p' are pointer types. The corresponding types with 518 * names ending 'rp' are identical pointer types except that the pointer is 519 * marked 'restrict', which means that it is the only pointer to the object 520 * passed to the function. Applications should not use the 'restrict' types; 521 * it is always valid to pass 'p' to a pointer with a function argument of the 522 * corresponding 'rp' type. Different compilers have different rules with 523 * regard to type matching in the presence of 'restrict'. For backward 524 * compatibility libpng callbacks never have 'restrict' in their parameters and, 525 * consequentially, writing portable application code is extremely difficult if 526 * an attempt is made to use 'restrict'. 527 */ 528 typedef png_struct * PNG_RESTRICT png_structrp; 529 typedef const png_struct * PNG_RESTRICT png_const_structrp; 530 typedef png_info * PNG_RESTRICT png_inforp; 531 typedef const png_info * PNG_RESTRICT png_const_inforp; 532 533 /* Three color definitions. The order of the red, green, and blue, (and the 534 * exact size) is not important, although the size of the fields need to 535 * be png_byte or png_uint_16 (as defined below). 536 */ 537 typedef struct png_color_struct 538 { 539 png_byte red; 540 png_byte green; 541 png_byte blue; 542 } png_color; 543 typedef png_color * png_colorp; 544 typedef const png_color * png_const_colorp; 545 typedef png_color * * png_colorpp; 546 547 typedef struct png_color_16_struct 548 { 549 png_byte index; /* used for palette files */ 550 png_uint_16 red; /* for use in red green blue files */ 551 png_uint_16 green; 552 png_uint_16 blue; 553 png_uint_16 gray; /* for use in grayscale files */ 554 } png_color_16; 555 typedef png_color_16 * png_color_16p; 556 typedef const png_color_16 * png_const_color_16p; 557 typedef png_color_16 * * png_color_16pp; 558 559 typedef struct png_color_8_struct 560 { 561 png_byte red; /* for use in red green blue files */ 562 png_byte green; 563 png_byte blue; 564 png_byte gray; /* for use in grayscale files */ 565 png_byte alpha; /* for alpha channel files */ 566 } png_color_8; 567 typedef png_color_8 * png_color_8p; 568 typedef const png_color_8 * png_const_color_8p; 569 typedef png_color_8 * * png_color_8pp; 570 571 /* 572 * The following two structures are used for the in-core representation 573 * of sPLT chunks. 574 */ 575 typedef struct png_sPLT_entry_struct 576 { 577 png_uint_16 red; 578 png_uint_16 green; 579 png_uint_16 blue; 580 png_uint_16 alpha; 581 png_uint_16 frequency; 582 } png_sPLT_entry; 583 typedef png_sPLT_entry * png_sPLT_entryp; 584 typedef const png_sPLT_entry * png_const_sPLT_entryp; 585 typedef png_sPLT_entry * * png_sPLT_entrypp; 586 587 /* When the depth of the sPLT palette is 8 bits, the color and alpha samples 588 * occupy the LSB of their respective members, and the MSB of each member 589 * is zero-filled. The frequency member always occupies the full 16 bits. 590 */ 591 592 typedef struct png_sPLT_struct 593 { 594 png_charp name; /* palette name */ 595 png_byte depth; /* depth of palette samples */ 596 png_sPLT_entryp entries; /* palette entries */ 597 png_int_32 nentries; /* number of palette entries */ 598 } png_sPLT_t; 599 typedef png_sPLT_t * png_sPLT_tp; 600 typedef const png_sPLT_t * png_const_sPLT_tp; 601 typedef png_sPLT_t * * png_sPLT_tpp; 602 603 #ifdef PNG_TEXT_SUPPORTED 604 /* png_text holds the contents of a text/ztxt/itxt chunk in a PNG file, 605 * and whether that contents is compressed or not. The "key" field 606 * points to a regular zero-terminated C string. The "text" fields can be a 607 * regular C string, an empty string, or a NULL pointer. 608 * However, the structure returned by png_get_text() will always contain 609 * the "text" field as a regular zero-terminated C string (possibly 610 * empty), never a NULL pointer, so it can be safely used in printf() and 611 * other string-handling functions. Note that the "itxt_length", "lang", and 612 * "lang_key" members of the structure only exist when the library is built 613 * with iTXt chunk support. Prior to libpng-1.4.0 the library was built by 614 * default without iTXt support. Also note that when iTXt *is* supported, 615 * the "lang" and "lang_key" fields contain NULL pointers when the 616 * "compression" field contains * PNG_TEXT_COMPRESSION_NONE or 617 * PNG_TEXT_COMPRESSION_zTXt. Note that the "compression value" is not the 618 * same as what appears in the PNG tEXt/zTXt/iTXt chunk's "compression flag" 619 * which is always 0 or 1, or its "compression method" which is always 0. 620 */ 621 typedef struct png_text_struct 622 { 623 int compression; /* compression value: 624 -1: tEXt, none 625 0: zTXt, deflate 626 1: iTXt, none 627 2: iTXt, deflate */ 628 png_charp key; /* keyword, 1-79 character description of "text" */ 629 png_charp text; /* comment, may be an empty string (ie "") 630 or a NULL pointer */ 631 png_size_t text_length; /* length of the text string */ 632 png_size_t itxt_length; /* length of the itxt string */ 633 png_charp lang; /* language code, 0-79 characters 634 or a NULL pointer */ 635 png_charp lang_key; /* keyword translated UTF-8 string, 0 or more 636 chars or a NULL pointer */ 637 } png_text; 638 typedef png_text * png_textp; 639 typedef const png_text * png_const_textp; 640 typedef png_text * * png_textpp; 641 #endif 642 643 /* Supported compression types for text in PNG files (tEXt, and zTXt). 644 * The values of the PNG_TEXT_COMPRESSION_ defines should NOT be changed. */ 645 #define PNG_TEXT_COMPRESSION_NONE_WR -3 646 #define PNG_TEXT_COMPRESSION_zTXt_WR -2 647 #define PNG_TEXT_COMPRESSION_NONE -1 648 #define PNG_TEXT_COMPRESSION_zTXt 0 649 #define PNG_ITXT_COMPRESSION_NONE 1 650 #define PNG_ITXT_COMPRESSION_zTXt 2 651 #define PNG_TEXT_COMPRESSION_LAST 3 /* Not a valid value */ 652 653 /* png_time is a way to hold the time in an machine independent way. 654 * Two conversions are provided, both from time_t and struct tm. There 655 * is no portable way to convert to either of these structures, as far 656 * as I know. If you know of a portable way, send it to me. As a side 657 * note - PNG has always been Year 2000 compliant! 658 */ 659 typedef struct png_time_struct 660 { 661 png_uint_16 year; /* full year, as in, 1995 */ 662 png_byte month; /* month of year, 1 - 12 */ 663 png_byte day; /* day of month, 1 - 31 */ 664 png_byte hour; /* hour of day, 0 - 23 */ 665 png_byte minute; /* minute of hour, 0 - 59 */ 666 png_byte second; /* second of minute, 0 - 60 (for leap seconds) */ 667 } png_time; 668 typedef png_time * png_timep; 669 typedef const png_time * png_const_timep; 670 typedef png_time * * png_timepp; 671 672 #if defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED) ||\ 673 defined(PNG_USER_CHUNKS_SUPPORTED) 674 /* png_unknown_chunk is a structure to hold queued chunks for which there is 675 * no specific support. The idea is that we can use this to queue 676 * up private chunks for output even though the library doesn't actually 677 * know about their semantics. 678 * 679 * The data in the structure is set by libpng on read and used on write. 680 */ 681 typedef struct png_unknown_chunk_t 682 { 683 png_byte name[5]; /* Textual chunk name with '\0' terminator */ 684 png_byte *data; /* Data, should not be modified on read! */ 685 png_size_t size; 686 687 /* On write 'location' must be set using the flag values listed below. 688 * Notice that on read it is set by libpng however the values stored have 689 * more bits set than are listed below. Always treat the value as a 690 * bitmask. On write set only one bit - setting multiple bits may cause the 691 * chunk to be written in multiple places. 692 */ 693 png_byte location; /* mode of operation at read time */ 694 } 695 png_unknown_chunk; 696 697 typedef png_unknown_chunk * png_unknown_chunkp; 698 typedef const png_unknown_chunk * png_const_unknown_chunkp; 699 typedef png_unknown_chunk * * png_unknown_chunkpp; 700 #endif 701 702 /* Flag values for the unknown chunk location byte. */ 703 #define PNG_HAVE_IHDR 0x01 704 #define PNG_HAVE_PLTE 0x02 705 #define PNG_AFTER_IDAT 0x08 706 707 /* Maximum positive integer used in PNG is (2^31)-1 */ 708 #define PNG_UINT_31_MAX ((png_uint_32)0x7fffffffL) 709 #define PNG_UINT_32_MAX ((png_uint_32)(-1)) 710 #define PNG_SIZE_MAX ((png_size_t)(-1)) 711 712 /* These are constants for fixed point values encoded in the 713 * PNG specification manner (x100000) 714 */ 715 #define PNG_FP_1 100000 716 #define PNG_FP_HALF 50000 717 #define PNG_FP_MAX ((png_fixed_point)0x7fffffffL) 718 #define PNG_FP_MIN (-PNG_FP_MAX) 719 720 /* These describe the color_type field in png_info. */ 721 /* color type masks */ 722 #define PNG_COLOR_MASK_PALETTE 1 723 #define PNG_COLOR_MASK_COLOR 2 724 #define PNG_COLOR_MASK_ALPHA 4 725 726 /* color types. Note that not all combinations are legal */ 727 #define PNG_COLOR_TYPE_GRAY 0 728 #define PNG_COLOR_TYPE_PALETTE (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE) 729 #define PNG_COLOR_TYPE_RGB (PNG_COLOR_MASK_COLOR) 730 #define PNG_COLOR_TYPE_RGB_ALPHA (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_ALPHA) 731 #define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA) 732 /* aliases */ 733 #define PNG_COLOR_TYPE_RGBA PNG_COLOR_TYPE_RGB_ALPHA 734 #define PNG_COLOR_TYPE_GA PNG_COLOR_TYPE_GRAY_ALPHA 735 736 /* This is for compression type. PNG 1.0-1.2 only define the single type. */ 737 #define PNG_COMPRESSION_TYPE_BASE 0 /* Deflate method 8, 32K window */ 738 #define PNG_COMPRESSION_TYPE_DEFAULT PNG_COMPRESSION_TYPE_BASE 739 740 /* This is for filter type. PNG 1.0-1.2 only define the single type. */ 741 #define PNG_FILTER_TYPE_BASE 0 /* Single row per-byte filtering */ 742 #define PNG_INTRAPIXEL_DIFFERENCING 64 /* Used only in MNG datastreams */ 743 #define PNG_FILTER_TYPE_DEFAULT PNG_FILTER_TYPE_BASE 744 745 /* These are for the interlacing type. These values should NOT be changed. */ 746 #define PNG_INTERLACE_NONE 0 /* Non-interlaced image */ 747 #define PNG_INTERLACE_ADAM7 1 /* Adam7 interlacing */ 748 #define PNG_INTERLACE_LAST 2 /* Not a valid value */ 749 750 /* These are for the oFFs chunk. These values should NOT be changed. */ 751 #define PNG_OFFSET_PIXEL 0 /* Offset in pixels */ 752 #define PNG_OFFSET_MICROMETER 1 /* Offset in micrometers (1/10^6 meter) */ 753 #define PNG_OFFSET_LAST 2 /* Not a valid value */ 754 755 /* These are for the pCAL chunk. These values should NOT be changed. */ 756 #define PNG_EQUATION_LINEAR 0 /* Linear transformation */ 757 #define PNG_EQUATION_BASE_E 1 /* Exponential base e transform */ 758 #define PNG_EQUATION_ARBITRARY 2 /* Arbitrary base exponential transform */ 759 #define PNG_EQUATION_HYPERBOLIC 3 /* Hyperbolic sine transformation */ 760 #define PNG_EQUATION_LAST 4 /* Not a valid value */ 761 762 /* These are for the sCAL chunk. These values should NOT be changed. */ 763 #define PNG_SCALE_UNKNOWN 0 /* unknown unit (image scale) */ 764 #define PNG_SCALE_METER 1 /* meters per pixel */ 765 #define PNG_SCALE_RADIAN 2 /* radians per pixel */ 766 #define PNG_SCALE_LAST 3 /* Not a valid value */ 767 768 /* These are for the pHYs chunk. These values should NOT be changed. */ 769 #define PNG_RESOLUTION_UNKNOWN 0 /* pixels/unknown unit (aspect ratio) */ 770 #define PNG_RESOLUTION_METER 1 /* pixels/meter */ 771 #define PNG_RESOLUTION_LAST 2 /* Not a valid value */ 772 773 /* These are for the sRGB chunk. These values should NOT be changed. */ 774 #define PNG_sRGB_INTENT_PERCEPTUAL 0 775 #define PNG_sRGB_INTENT_RELATIVE 1 776 #define PNG_sRGB_INTENT_SATURATION 2 777 #define PNG_sRGB_INTENT_ABSOLUTE 3 778 #define PNG_sRGB_INTENT_LAST 4 /* Not a valid value */ 779 780 /* This is for text chunks */ 781 #define PNG_KEYWORD_MAX_LENGTH 79 782 783 /* Maximum number of entries in PLTE/sPLT/tRNS arrays */ 784 #define PNG_MAX_PALETTE_LENGTH 256 785 786 /* These determine if an ancillary chunk's data has been successfully read 787 * from the PNG header, or if the application has filled in the corresponding 788 * data in the info_struct to be written into the output file. The values 789 * of the PNG_INFO_<chunk> defines should NOT be changed. 790 */ 791 #define PNG_INFO_gAMA 0x0001U 792 #define PNG_INFO_sBIT 0x0002U 793 #define PNG_INFO_cHRM 0x0004U 794 #define PNG_INFO_PLTE 0x0008U 795 #define PNG_INFO_tRNS 0x0010U 796 #define PNG_INFO_bKGD 0x0020U 797 #define PNG_INFO_hIST 0x0040U 798 #define PNG_INFO_pHYs 0x0080U 799 #define PNG_INFO_oFFs 0x0100U 800 #define PNG_INFO_tIME 0x0200U 801 #define PNG_INFO_pCAL 0x0400U 802 #define PNG_INFO_sRGB 0x0800U /* GR-P, 0.96a */ 803 #define PNG_INFO_iCCP 0x1000U /* ESR, 1.0.6 */ 804 #define PNG_INFO_sPLT 0x2000U /* ESR, 1.0.6 */ 805 #define PNG_INFO_sCAL 0x4000U /* ESR, 1.0.6 */ 806 #define PNG_INFO_IDAT 0x8000U /* ESR, 1.0.6 */ 807 #define PNG_INFO_eXIf 0x10000U /* GR-P, 1.6.31 */ 808 809 /* This is used for the transformation routines, as some of them 810 * change these values for the row. It also should enable using 811 * the routines for other purposes. 812 */ 813 typedef struct png_row_info_struct 814 { 815 png_uint_32 width; /* width of row */ 816 png_size_t rowbytes; /* number of bytes in row */ 817 png_byte color_type; /* color type of row */ 818 png_byte bit_depth; /* bit depth of row */ 819 png_byte channels; /* number of channels (1, 2, 3, or 4) */ 820 png_byte pixel_depth; /* bits per pixel (depth * channels) */ 821 } png_row_info; 822 823 typedef png_row_info * png_row_infop; 824 typedef png_row_info * * png_row_infopp; 825 826 /* These are the function types for the I/O functions and for the functions 827 * that allow the user to override the default I/O functions with his or her 828 * own. The png_error_ptr type should match that of user-supplied warning 829 * and error functions, while the png_rw_ptr type should match that of the 830 * user read/write data functions. Note that the 'write' function must not 831 * modify the buffer it is passed. The 'read' function, on the other hand, is 832 * expected to return the read data in the buffer. 833 */ 834 typedef PNG_CALLBACK(void, *png_error_ptr, (png_structp, png_const_charp)); 835 typedef PNG_CALLBACK(void, *png_rw_ptr, (png_structp, png_bytep, png_size_t)); 836 typedef PNG_CALLBACK(void, *png_flush_ptr, (png_structp)); 837 typedef PNG_CALLBACK(void, *png_read_status_ptr, (png_structp, png_uint_32, 838 int)); 839 typedef PNG_CALLBACK(void, *png_write_status_ptr, (png_structp, png_uint_32, 840 int)); 841 842 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED 843 typedef PNG_CALLBACK(void, *png_progressive_info_ptr, (png_structp, png_infop)); 844 typedef PNG_CALLBACK(void, *png_progressive_end_ptr, (png_structp, png_infop)); 845 846 /* The following callback receives png_uint_32 row_number, int pass for the 847 * png_bytep data of the row. When transforming an interlaced image the 848 * row number is the row number within the sub-image of the interlace pass, so 849 * the value will increase to the height of the sub-image (not the full image) 850 * then reset to 0 for the next pass. 851 * 852 * Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to 853 * find the output pixel (x,y) given an interlaced sub-image pixel 854 * (row,col,pass). (See below for these macros.) 855 */ 856 typedef PNG_CALLBACK(void, *png_progressive_row_ptr, (png_structp, png_bytep, 857 png_uint_32, int)); 858 #endif 859 860 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \ 861 defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) 862 typedef PNG_CALLBACK(void, *png_user_transform_ptr, (png_structp, png_row_infop, 863 png_bytep)); 864 #endif 865 866 #ifdef PNG_USER_CHUNKS_SUPPORTED 867 typedef PNG_CALLBACK(int, *png_user_chunk_ptr, (png_structp, 868 png_unknown_chunkp)); 869 #endif 870 #ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED 871 /* not used anywhere */ 872 /* typedef PNG_CALLBACK(void, *png_unknown_chunk_ptr, (png_structp)); */ 873 #endif 874 875 #ifdef PNG_SETJMP_SUPPORTED 876 /* This must match the function definition in <setjmp.h>, and the application 877 * must include this before png.h to obtain the definition of jmp_buf. The 878 * function is required to be PNG_NORETURN, but this is not checked. If the 879 * function does return the application will crash via an abort() or similar 880 * system level call. 881 * 882 * If you get a warning here while building the library you may need to make 883 * changes to ensure that pnglibconf.h records the calling convention used by 884 * your compiler. This may be very difficult - try using a different compiler 885 * to build the library! 886 */ 887 PNG_FUNCTION(void, (PNGCAPI *png_longjmp_ptr), PNGARG((jmp_buf, int)), typedef); 888 #endif 889 890 /* Transform masks for the high-level interface */ 891 #define PNG_TRANSFORM_IDENTITY 0x0000 /* read and write */ 892 #define PNG_TRANSFORM_STRIP_16 0x0001 /* read only */ 893 #define PNG_TRANSFORM_STRIP_ALPHA 0x0002 /* read only */ 894 #define PNG_TRANSFORM_PACKING 0x0004 /* read and write */ 895 #define PNG_TRANSFORM_PACKSWAP 0x0008 /* read and write */ 896 #define PNG_TRANSFORM_EXPAND 0x0010 /* read only */ 897 #define PNG_TRANSFORM_INVERT_MONO 0x0020 /* read and write */ 898 #define PNG_TRANSFORM_SHIFT 0x0040 /* read and write */ 899 #define PNG_TRANSFORM_BGR 0x0080 /* read and write */ 900 #define PNG_TRANSFORM_SWAP_ALPHA 0x0100 /* read and write */ 901 #define PNG_TRANSFORM_SWAP_ENDIAN 0x0200 /* read and write */ 902 #define PNG_TRANSFORM_INVERT_ALPHA 0x0400 /* read and write */ 903 #define PNG_TRANSFORM_STRIP_FILLER 0x0800 /* write only */ 904 /* Added to libpng-1.2.34 */ 905 #define PNG_TRANSFORM_STRIP_FILLER_BEFORE PNG_TRANSFORM_STRIP_FILLER 906 #define PNG_TRANSFORM_STRIP_FILLER_AFTER 0x1000 /* write only */ 907 /* Added to libpng-1.4.0 */ 908 #define PNG_TRANSFORM_GRAY_TO_RGB 0x2000 /* read only */ 909 /* Added to libpng-1.5.4 */ 910 #define PNG_TRANSFORM_EXPAND_16 0x4000 /* read only */ 911 #if INT_MAX >= 0x8000 /* else this might break */ 912 #define PNG_TRANSFORM_SCALE_16 0x8000 /* read only */ 913 #endif 914 915 /* Flags for MNG supported features */ 916 #define PNG_FLAG_MNG_EMPTY_PLTE 0x01 917 #define PNG_FLAG_MNG_FILTER_64 0x04 918 #define PNG_ALL_MNG_FEATURES 0x05 919 920 /* NOTE: prior to 1.5 these functions had no 'API' style declaration, 921 * this allowed the zlib default functions to be used on Windows 922 * platforms. In 1.5 the zlib default malloc (which just calls malloc and 923 * ignores the first argument) should be completely compatible with the 924 * following. 925 */ 926 typedef PNG_CALLBACK(png_voidp, *png_malloc_ptr, (png_structp, 927 png_alloc_size_t)); 928 typedef PNG_CALLBACK(void, *png_free_ptr, (png_structp, png_voidp)); 929 930 /* Section 4: exported functions 931 * Here are the function definitions most commonly used. This is not 932 * the place to find out how to use libpng. See libpng-manual.txt for the 933 * full explanation, see example.c for the summary. This just provides 934 * a simple one line description of the use of each function. 935 * 936 * The PNG_EXPORT() and PNG_EXPORTA() macros used below are defined in 937 * pngconf.h and in the *.dfn files in the scripts directory. 938 * 939 * PNG_EXPORT(ordinal, type, name, (args)); 940 * 941 * ordinal: ordinal that is used while building 942 * *.def files. The ordinal value is only 943 * relevant when preprocessing png.h with 944 * the *.dfn files for building symbol table 945 * entries, and are removed by pngconf.h. 946 * type: return type of the function 947 * name: function name 948 * args: function arguments, with types 949 * 950 * When we wish to append attributes to a function prototype we use 951 * the PNG_EXPORTA() macro instead. 952 * 953 * PNG_EXPORTA(ordinal, type, name, (args), attributes); 954 * 955 * ordinal, type, name, and args: same as in PNG_EXPORT(). 956 * attributes: function attributes 957 */ 958 959 /* Returns the version number of the library */ 960 PNG_EXPORT(1, png_uint_32, png_access_version_number, (void)); 961 962 /* Tell lib we have already handled the first <num_bytes> magic bytes. 963 * Handling more than 8 bytes from the beginning of the file is an error. 964 */ 965 PNG_EXPORT(2, void, png_set_sig_bytes, (png_structrp png_ptr, int num_bytes)); 966 967 /* Check sig[start] through sig[start + num_to_check - 1] to see if it's a 968 * PNG file. Returns zero if the supplied bytes match the 8-byte PNG 969 * signature, and non-zero otherwise. Having num_to_check == 0 or 970 * start > 7 will always fail (ie return non-zero). 971 */ 972 PNG_EXPORT(3, int, png_sig_cmp, (png_const_bytep sig, png_size_t start, 973 png_size_t num_to_check)); 974 975 /* Simple signature checking function. This is the same as calling 976 * png_check_sig(sig, n) := !png_sig_cmp(sig, 0, n). 977 */ 978 #define png_check_sig(sig, n) !png_sig_cmp((sig), 0, (n)) 979 980 /* Allocate and initialize png_ptr struct for reading, and any other memory. */ 981 PNG_EXPORTA(4, png_structp, png_create_read_struct, 982 (png_const_charp user_png_ver, png_voidp error_ptr, 983 png_error_ptr error_fn, png_error_ptr warn_fn), 984 PNG_ALLOCATED); 985 986 /* Allocate and initialize png_ptr struct for writing, and any other memory */ 987 PNG_EXPORTA(5, png_structp, png_create_write_struct, 988 (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn, 989 png_error_ptr warn_fn), 990 PNG_ALLOCATED); 991 992 PNG_EXPORT(6, png_size_t, png_get_compression_buffer_size, 993 (png_const_structrp png_ptr)); 994 995 PNG_EXPORT(7, void, png_set_compression_buffer_size, (png_structrp png_ptr, 996 png_size_t size)); 997 998 /* Moved from pngconf.h in 1.4.0 and modified to ensure setjmp/longjmp 999 * match up. 1000 */ 1001 #ifdef PNG_SETJMP_SUPPORTED 1002 /* This function returns the jmp_buf built in to *png_ptr. It must be 1003 * supplied with an appropriate 'longjmp' function to use on that jmp_buf 1004 * unless the default error function is overridden in which case NULL is 1005 * acceptable. The size of the jmp_buf is checked against the actual size 1006 * allocated by the library - the call will return NULL on a mismatch 1007 * indicating an ABI mismatch. 1008 */ 1009 PNG_EXPORT(8, jmp_buf*, png_set_longjmp_fn, (png_structrp png_ptr, 1010 png_longjmp_ptr longjmp_fn, size_t jmp_buf_size)); 1011 # define png_jmpbuf(png_ptr) \ 1012 (*png_set_longjmp_fn((png_ptr), longjmp, (sizeof (jmp_buf)))) 1013 #else 1014 # define png_jmpbuf(png_ptr) \ 1015 (LIBPNG_WAS_COMPILED_WITH__PNG_NO_SETJMP) 1016 #endif 1017 /* This function should be used by libpng applications in place of 1018 * longjmp(png_ptr->jmpbuf, val). If longjmp_fn() has been set, it 1019 * will use it; otherwise it will call PNG_ABORT(). This function was 1020 * added in libpng-1.5.0. 1021 */ 1022 PNG_EXPORTA(9, void, png_longjmp, (png_const_structrp png_ptr, int val), 1023 PNG_NORETURN); 1024 1025 #ifdef PNG_READ_SUPPORTED 1026 /* Reset the compression stream */ 1027 PNG_EXPORTA(10, int, png_reset_zstream, (png_structrp png_ptr), PNG_DEPRECATED); 1028 #endif 1029 1030 /* New functions added in libpng-1.0.2 (not enabled by default until 1.2.0) */ 1031 #ifdef PNG_USER_MEM_SUPPORTED 1032 PNG_EXPORTA(11, png_structp, png_create_read_struct_2, 1033 (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn, 1034 png_error_ptr warn_fn, 1035 png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn), 1036 PNG_ALLOCATED); 1037 PNG_EXPORTA(12, png_structp, png_create_write_struct_2, 1038 (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn, 1039 png_error_ptr warn_fn, 1040 png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn), 1041 PNG_ALLOCATED); 1042 #endif 1043 1044 /* Write the PNG file signature. */ 1045 PNG_EXPORT(13, void, png_write_sig, (png_structrp png_ptr)); 1046 1047 /* Write a PNG chunk - size, type, (optional) data, CRC. */ 1048 PNG_EXPORT(14, void, png_write_chunk, (png_structrp png_ptr, png_const_bytep 1049 chunk_name, png_const_bytep data, png_size_t length)); 1050 1051 /* Write the start of a PNG chunk - length and chunk name. */ 1052 PNG_EXPORT(15, void, png_write_chunk_start, (png_structrp png_ptr, 1053 png_const_bytep chunk_name, png_uint_32 length)); 1054 1055 /* Write the data of a PNG chunk started with png_write_chunk_start(). */ 1056 PNG_EXPORT(16, void, png_write_chunk_data, (png_structrp png_ptr, 1057 png_const_bytep data, png_size_t length)); 1058 1059 /* Finish a chunk started with png_write_chunk_start() (includes CRC). */ 1060 PNG_EXPORT(17, void, png_write_chunk_end, (png_structrp png_ptr)); 1061 1062 /* Allocate and initialize the info structure */ 1063 PNG_EXPORTA(18, png_infop, png_create_info_struct, (png_const_structrp png_ptr), 1064 PNG_ALLOCATED); 1065 1066 /* DEPRECATED: this function allowed init structures to be created using the 1067 * default allocation method (typically malloc). Use is deprecated in 1.6.0 and 1068 * the API will be removed in the future. 1069 */ 1070 PNG_EXPORTA(19, void, png_info_init_3, (png_infopp info_ptr, 1071 png_size_t png_info_struct_size), PNG_DEPRECATED); 1072 1073 /* Writes all the PNG information before the image. */ 1074 PNG_EXPORT(20, void, png_write_info_before_PLTE, 1075 (png_structrp png_ptr, png_const_inforp info_ptr)); 1076 PNG_EXPORT(21, void, png_write_info, 1077 (png_structrp png_ptr, png_const_inforp info_ptr)); 1078 1079 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED 1080 /* Read the information before the actual image data. */ 1081 PNG_EXPORT(22, void, png_read_info, 1082 (png_structrp png_ptr, png_inforp info_ptr)); 1083 #endif 1084 1085 #ifdef PNG_TIME_RFC1123_SUPPORTED 1086 /* Convert to a US string format: there is no localization support in this 1087 * routine. The original implementation used a 29 character buffer in 1088 * png_struct, this will be removed in future versions. 1089 */ 1090 #if PNG_LIBPNG_VER < 10700 1091 /* To do: remove this from libpng17 (and from libpng17/png.c and pngstruct.h) */ 1092 PNG_EXPORTA(23, png_const_charp, png_convert_to_rfc1123, (png_structrp png_ptr, 1093 png_const_timep ptime),PNG_DEPRECATED); 1094 #endif 1095 PNG_EXPORT(241, int, png_convert_to_rfc1123_buffer, (char out[29], 1096 png_const_timep ptime)); 1097 #endif 1098 1099 #ifdef PNG_CONVERT_tIME_SUPPORTED 1100 /* Convert from a struct tm to png_time */ 1101 PNG_EXPORT(24, void, png_convert_from_struct_tm, (png_timep ptime, 1102 const struct tm * ttime)); 1103 1104 /* Convert from time_t to png_time. Uses gmtime() */ 1105 PNG_EXPORT(25, void, png_convert_from_time_t, (png_timep ptime, time_t ttime)); 1106 #endif /* CONVERT_tIME */ 1107 1108 #ifdef PNG_READ_EXPAND_SUPPORTED 1109 /* Expand data to 24-bit RGB, or 8-bit grayscale, with alpha if available. */ 1110 PNG_EXPORT(26, void, png_set_expand, (png_structrp png_ptr)); 1111 PNG_EXPORT(27, void, png_set_expand_gray_1_2_4_to_8, (png_structrp png_ptr)); 1112 PNG_EXPORT(28, void, png_set_palette_to_rgb, (png_structrp png_ptr)); 1113 PNG_EXPORT(29, void, png_set_tRNS_to_alpha, (png_structrp png_ptr)); 1114 #endif 1115 1116 #ifdef PNG_READ_EXPAND_16_SUPPORTED 1117 /* Expand to 16-bit channels, forces conversion of palette to RGB and expansion 1118 * of a tRNS chunk if present. 1119 */ 1120 PNG_EXPORT(221, void, png_set_expand_16, (png_structrp png_ptr)); 1121 #endif 1122 1123 #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED) 1124 /* Use blue, green, red order for pixels. */ 1125 PNG_EXPORT(30, void, png_set_bgr, (png_structrp png_ptr)); 1126 #endif 1127 1128 #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED 1129 /* Expand the grayscale to 24-bit RGB if necessary. */ 1130 PNG_EXPORT(31, void, png_set_gray_to_rgb, (png_structrp png_ptr)); 1131 #endif 1132 1133 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED 1134 /* Reduce RGB to grayscale. */ 1135 #define PNG_ERROR_ACTION_NONE 1 1136 #define PNG_ERROR_ACTION_WARN 2 1137 #define PNG_ERROR_ACTION_ERROR 3 1138 #define PNG_RGB_TO_GRAY_DEFAULT (-1)/*for red/green coefficients*/ 1139 1140 PNG_FP_EXPORT(32, void, png_set_rgb_to_gray, (png_structrp png_ptr, 1141 int error_action, double red, double green)) 1142 PNG_FIXED_EXPORT(33, void, png_set_rgb_to_gray_fixed, (png_structrp png_ptr, 1143 int error_action, png_fixed_point red, png_fixed_point green)) 1144 1145 PNG_EXPORT(34, png_byte, png_get_rgb_to_gray_status, (png_const_structrp 1146 png_ptr)); 1147 #endif 1148 1149 #ifdef PNG_BUILD_GRAYSCALE_PALETTE_SUPPORTED 1150 PNG_EXPORT(35, void, png_build_grayscale_palette, (int bit_depth, 1151 png_colorp palette)); 1152 #endif 1153 1154 #ifdef PNG_READ_ALPHA_MODE_SUPPORTED 1155 /* How the alpha channel is interpreted - this affects how the color channels 1156 * of a PNG file are returned to the calling application when an alpha channel, 1157 * or a tRNS chunk in a palette file, is present. 1158 * 1159 * This has no effect on the way pixels are written into a PNG output 1160 * datastream. The color samples in a PNG datastream are never premultiplied 1161 * with the alpha samples. 1162 * 1163 * The default is to return data according to the PNG specification: the alpha 1164 * channel is a linear measure of the contribution of the pixel to the 1165 * corresponding composited pixel, and the color channels are unassociated 1166 * (not premultiplied). The gamma encoded color channels must be scaled 1167 * according to the contribution and to do this it is necessary to undo 1168 * the encoding, scale the color values, perform the composition and reencode 1169 * the values. This is the 'PNG' mode. 1170 * 1171 * The alternative is to 'associate' the alpha with the color information by 1172 * storing color channel values that have been scaled by the alpha. 1173 * image. These are the 'STANDARD', 'ASSOCIATED' or 'PREMULTIPLIED' modes 1174 * (the latter being the two common names for associated alpha color channels). 1175 * 1176 * For the 'OPTIMIZED' mode, a pixel is treated as opaque only if the alpha 1177 * value is equal to the maximum value. 1178 * 1179 * The final choice is to gamma encode the alpha channel as well. This is 1180 * broken because, in practice, no implementation that uses this choice 1181 * correctly undoes the encoding before handling alpha composition. Use this 1182 * choice only if other serious errors in the software or hardware you use 1183 * mandate it; the typical serious error is for dark halos to appear around 1184 * opaque areas of the composited PNG image because of arithmetic overflow. 1185 * 1186 * The API function png_set_alpha_mode specifies which of these choices to use 1187 * with an enumerated 'mode' value and the gamma of the required output: 1188 */ 1189 #define PNG_ALPHA_PNG 0 /* according to the PNG standard */ 1190 #define PNG_ALPHA_STANDARD 1 /* according to Porter/Duff */ 1191 #define PNG_ALPHA_ASSOCIATED 1 /* as above; this is the normal practice */ 1192 #define PNG_ALPHA_PREMULTIPLIED 1 /* as above */ 1193 #define PNG_ALPHA_OPTIMIZED 2 /* 'PNG' for opaque pixels, else 'STANDARD' */ 1194 #define PNG_ALPHA_BROKEN 3 /* the alpha channel is gamma encoded */ 1195 1196 PNG_FP_EXPORT(227, void, png_set_alpha_mode, (png_structrp png_ptr, int mode, 1197 double output_gamma)) 1198 PNG_FIXED_EXPORT(228, void, png_set_alpha_mode_fixed, (png_structrp png_ptr, 1199 int mode, png_fixed_point output_gamma)) 1200 #endif 1201 1202 #if defined(PNG_GAMMA_SUPPORTED) || defined(PNG_READ_ALPHA_MODE_SUPPORTED) 1203 /* The output_gamma value is a screen gamma in libpng terminology: it expresses 1204 * how to decode the output values, not how they are encoded. 1205 */ 1206 #define PNG_DEFAULT_sRGB -1 /* sRGB gamma and color space */ 1207 #define PNG_GAMMA_MAC_18 -2 /* Old Mac '1.8' gamma and color space */ 1208 #define PNG_GAMMA_sRGB 220000 /* Television standards--matches sRGB gamma */ 1209 #define PNG_GAMMA_LINEAR PNG_FP_1 /* Linear */ 1210 #endif 1211 1212 /* The following are examples of calls to png_set_alpha_mode to achieve the 1213 * required overall gamma correction and, where necessary, alpha 1214 * premultiplication. 1215 * 1216 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB); 1217 * This is the default libpng handling of the alpha channel - it is not 1218 * pre-multiplied into the color components. In addition the call states 1219 * that the output is for a sRGB system and causes all PNG files without gAMA 1220 * chunks to be assumed to be encoded using sRGB. 1221 * 1222 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC); 1223 * In this case the output is assumed to be something like an sRGB conformant 1224 * display preceeded by a power-law lookup table of power 1.45. This is how 1225 * early Mac systems behaved. 1226 * 1227 * png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_GAMMA_LINEAR); 1228 * This is the classic Jim Blinn approach and will work in academic 1229 * environments where everything is done by the book. It has the shortcoming 1230 * of assuming that input PNG data with no gamma information is linear - this 1231 * is unlikely to be correct unless the PNG files where generated locally. 1232 * Most of the time the output precision will be so low as to show 1233 * significant banding in dark areas of the image. 1234 * 1235 * png_set_expand_16(pp); 1236 * png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_DEFAULT_sRGB); 1237 * This is a somewhat more realistic Jim Blinn inspired approach. PNG files 1238 * are assumed to have the sRGB encoding if not marked with a gamma value and 1239 * the output is always 16 bits per component. This permits accurate scaling 1240 * and processing of the data. If you know that your input PNG files were 1241 * generated locally you might need to replace PNG_DEFAULT_sRGB with the 1242 * correct value for your system. 1243 * 1244 * png_set_alpha_mode(pp, PNG_ALPHA_OPTIMIZED, PNG_DEFAULT_sRGB); 1245 * If you just need to composite the PNG image onto an existing background 1246 * and if you control the code that does this you can use the optimization 1247 * setting. In this case you just copy completely opaque pixels to the 1248 * output. For pixels that are not completely transparent (you just skip 1249 * those) you do the composition math using png_composite or png_composite_16 1250 * below then encode the resultant 8-bit or 16-bit values to match the output 1251 * encoding. 1252 * 1253 * Other cases 1254 * If neither the PNG nor the standard linear encoding work for you because 1255 * of the software or hardware you use then you have a big problem. The PNG 1256 * case will probably result in halos around the image. The linear encoding 1257 * will probably result in a washed out, too bright, image (it's actually too 1258 * contrasty.) Try the ALPHA_OPTIMIZED mode above - this will probably 1259 * substantially reduce the halos. Alternatively try: 1260 * 1261 * png_set_alpha_mode(pp, PNG_ALPHA_BROKEN, PNG_DEFAULT_sRGB); 1262 * This option will also reduce the halos, but there will be slight dark 1263 * halos round the opaque parts of the image where the background is light. 1264 * In the OPTIMIZED mode the halos will be light halos where the background 1265 * is dark. Take your pick - the halos are unavoidable unless you can get 1266 * your hardware/software fixed! (The OPTIMIZED approach is slightly 1267 * faster.) 1268 * 1269 * When the default gamma of PNG files doesn't match the output gamma. 1270 * If you have PNG files with no gamma information png_set_alpha_mode allows 1271 * you to provide a default gamma, but it also sets the ouput gamma to the 1272 * matching value. If you know your PNG files have a gamma that doesn't 1273 * match the output you can take advantage of the fact that 1274 * png_set_alpha_mode always sets the output gamma but only sets the PNG 1275 * default if it is not already set: 1276 * 1277 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB); 1278 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC); 1279 * The first call sets both the default and the output gamma values, the 1280 * second call overrides the output gamma without changing the default. This 1281 * is easier than achieving the same effect with png_set_gamma. You must use 1282 * PNG_ALPHA_PNG for the first call - internal checking in png_set_alpha will 1283 * fire if more than one call to png_set_alpha_mode and png_set_background is 1284 * made in the same read operation, however multiple calls with PNG_ALPHA_PNG 1285 * are ignored. 1286 */ 1287 1288 #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED 1289 PNG_EXPORT(36, void, png_set_strip_alpha, (png_structrp png_ptr)); 1290 #endif 1291 1292 #if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \ 1293 defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED) 1294 PNG_EXPORT(37, void, png_set_swap_alpha, (png_structrp png_ptr)); 1295 #endif 1296 1297 #if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \ 1298 defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED) 1299 PNG_EXPORT(38, void, png_set_invert_alpha, (png_structrp png_ptr)); 1300 #endif 1301 1302 #if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED) 1303 /* Add a filler byte to 8-bit or 16-bit Gray or 24-bit or 48-bit RGB images. */ 1304 PNG_EXPORT(39, void, png_set_filler, (png_structrp png_ptr, png_uint_32 filler, 1305 int flags)); 1306 /* The values of the PNG_FILLER_ defines should NOT be changed */ 1307 # define PNG_FILLER_BEFORE 0 1308 # define PNG_FILLER_AFTER 1 1309 /* Add an alpha byte to 8-bit or 16-bit Gray or 24-bit or 48-bit RGB images. */ 1310 PNG_EXPORT(40, void, png_set_add_alpha, (png_structrp png_ptr, 1311 png_uint_32 filler, int flags)); 1312 #endif /* READ_FILLER || WRITE_FILLER */ 1313 1314 #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED) 1315 /* Swap bytes in 16-bit depth files. */ 1316 PNG_EXPORT(41, void, png_set_swap, (png_structrp png_ptr)); 1317 #endif 1318 1319 #if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED) 1320 /* Use 1 byte per pixel in 1, 2, or 4-bit depth files. */ 1321 PNG_EXPORT(42, void, png_set_packing, (png_structrp png_ptr)); 1322 #endif 1323 1324 #if defined(PNG_READ_PACKSWAP_SUPPORTED) || \ 1325 defined(PNG_WRITE_PACKSWAP_SUPPORTED) 1326 /* Swap packing order of pixels in bytes. */ 1327 PNG_EXPORT(43, void, png_set_packswap, (png_structrp png_ptr)); 1328 #endif 1329 1330 #if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED) 1331 /* Converts files to legal bit depths. */ 1332 PNG_EXPORT(44, void, png_set_shift, (png_structrp png_ptr, png_const_color_8p 1333 true_bits)); 1334 #endif 1335 1336 #if defined(PNG_READ_INTERLACING_SUPPORTED) || \ 1337 defined(PNG_WRITE_INTERLACING_SUPPORTED) 1338 /* Have the code handle the interlacing. Returns the number of passes. 1339 * MUST be called before png_read_update_info or png_start_read_image, 1340 * otherwise it will not have the desired effect. Note that it is still 1341 * necessary to call png_read_row or png_read_rows png_get_image_height 1342 * times for each pass. 1343 */ 1344 PNG_EXPORT(45, int, png_set_interlace_handling, (png_structrp png_ptr)); 1345 #endif 1346 1347 #if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED) 1348 /* Invert monochrome files */ 1349 PNG_EXPORT(46, void, png_set_invert_mono, (png_structrp png_ptr)); 1350 #endif 1351 1352 #ifdef PNG_READ_BACKGROUND_SUPPORTED 1353 /* Handle alpha and tRNS by replacing with a background color. Prior to 1354 * libpng-1.5.4 this API must not be called before the PNG file header has been 1355 * read. Doing so will result in unexpected behavior and possible warnings or 1356 * errors if the PNG file contains a bKGD chunk. 1357 */ 1358 PNG_FP_EXPORT(47, void, png_set_background, (png_structrp png_ptr, 1359 png_const_color_16p background_color, int background_gamma_code, 1360 int need_expand, double background_gamma)) 1361 PNG_FIXED_EXPORT(215, void, png_set_background_fixed, (png_structrp png_ptr, 1362 png_const_color_16p background_color, int background_gamma_code, 1363 int need_expand, png_fixed_point background_gamma)) 1364 #endif 1365 #ifdef PNG_READ_BACKGROUND_SUPPORTED 1366 # define PNG_BACKGROUND_GAMMA_UNKNOWN 0 1367 # define PNG_BACKGROUND_GAMMA_SCREEN 1 1368 # define PNG_BACKGROUND_GAMMA_FILE 2 1369 # define PNG_BACKGROUND_GAMMA_UNIQUE 3 1370 #endif 1371 1372 #ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED 1373 /* Scale a 16-bit depth file down to 8-bit, accurately. */ 1374 PNG_EXPORT(229, void, png_set_scale_16, (png_structrp png_ptr)); 1375 #endif 1376 1377 #ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED 1378 #define PNG_READ_16_TO_8_SUPPORTED /* Name prior to 1.5.4 */ 1379 /* Strip the second byte of information from a 16-bit depth file. */ 1380 PNG_EXPORT(48, void, png_set_strip_16, (png_structrp png_ptr)); 1381 #endif 1382 1383 #ifdef PNG_READ_QUANTIZE_SUPPORTED 1384 /* Turn on quantizing, and reduce the palette to the number of colors 1385 * available. 1386 */ 1387 PNG_EXPORT(49, void, png_set_quantize, (png_structrp png_ptr, 1388 png_colorp palette, int num_palette, int maximum_colors, 1389 png_const_uint_16p histogram, int full_quantize)); 1390 #endif 1391 1392 #ifdef PNG_READ_GAMMA_SUPPORTED 1393 /* The threshold on gamma processing is configurable but hard-wired into the 1394 * library. The following is the floating point variant. 1395 */ 1396 #define PNG_GAMMA_THRESHOLD (PNG_GAMMA_THRESHOLD_FIXED*.00001) 1397 1398 /* Handle gamma correction. Screen_gamma=(display_exponent). 1399 * NOTE: this API simply sets the screen and file gamma values. It will 1400 * therefore override the value for gamma in a PNG file if it is called after 1401 * the file header has been read - use with care - call before reading the PNG 1402 * file for best results! 1403 * 1404 * These routines accept the same gamma values as png_set_alpha_mode (described 1405 * above). The PNG_GAMMA_ defines and PNG_DEFAULT_sRGB can be passed to either 1406 * API (floating point or fixed.) Notice, however, that the 'file_gamma' value 1407 * is the inverse of a 'screen gamma' value. 1408 */ 1409 PNG_FP_EXPORT(50, void, png_set_gamma, (png_structrp png_ptr, 1410 double screen_gamma, double override_file_gamma)) 1411 PNG_FIXED_EXPORT(208, void, png_set_gamma_fixed, (png_structrp png_ptr, 1412 png_fixed_point screen_gamma, png_fixed_point override_file_gamma)) 1413 #endif 1414 1415 #ifdef PNG_WRITE_FLUSH_SUPPORTED 1416 /* Set how many lines between output flushes - 0 for no flushing */ 1417 PNG_EXPORT(51, void, png_set_flush, (png_structrp png_ptr, int nrows)); 1418 /* Flush the current PNG output buffer */ 1419 PNG_EXPORT(52, void, png_write_flush, (png_structrp png_ptr)); 1420 #endif 1421 1422 /* Optional update palette with requested transformations */ 1423 PNG_EXPORT(53, void, png_start_read_image, (png_structrp png_ptr)); 1424 1425 /* Optional call to update the users info structure */ 1426 PNG_EXPORT(54, void, png_read_update_info, (png_structrp png_ptr, 1427 png_inforp info_ptr)); 1428 1429 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED 1430 /* Read one or more rows of image data. */ 1431 PNG_EXPORT(55, void, png_read_rows, (png_structrp png_ptr, png_bytepp row, 1432 png_bytepp display_row, png_uint_32 num_rows)); 1433 #endif 1434 1435 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED 1436 /* Read a row of data. */ 1437 PNG_EXPORT(56, void, png_read_row, (png_structrp png_ptr, png_bytep row, 1438 png_bytep display_row)); 1439 #endif 1440 1441 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED 1442 /* Read the whole image into memory at once. */ 1443 PNG_EXPORT(57, void, png_read_image, (png_structrp png_ptr, png_bytepp image)); 1444 #endif 1445 1446 /* Write a row of image data */ 1447 PNG_EXPORT(58, void, png_write_row, (png_structrp png_ptr, 1448 png_const_bytep row)); 1449 1450 /* Write a few rows of image data: (*row) is not written; however, the type 1451 * is declared as writeable to maintain compatibility with previous versions 1452 * of libpng and to allow the 'display_row' array from read_rows to be passed 1453 * unchanged to write_rows. 1454 */ 1455 PNG_EXPORT(59, void, png_write_rows, (png_structrp png_ptr, png_bytepp row, 1456 png_uint_32 num_rows)); 1457 1458 /* Write the image data */ 1459 PNG_EXPORT(60, void, png_write_image, (png_structrp png_ptr, png_bytepp image)); 1460 1461 /* Write the end of the PNG file. */ 1462 PNG_EXPORT(61, void, png_write_end, (png_structrp png_ptr, 1463 png_inforp info_ptr)); 1464 1465 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED 1466 /* Read the end of the PNG file. */ 1467 PNG_EXPORT(62, void, png_read_end, (png_structrp png_ptr, png_inforp info_ptr)); 1468 #endif 1469 1470 /* Free any memory associated with the png_info_struct */ 1471 PNG_EXPORT(63, void, png_destroy_info_struct, (png_const_structrp png_ptr, 1472 png_infopp info_ptr_ptr)); 1473 1474 /* Free any memory associated with the png_struct and the png_info_structs */ 1475 PNG_EXPORT(64, void, png_destroy_read_struct, (png_structpp png_ptr_ptr, 1476 png_infopp info_ptr_ptr, png_infopp end_info_ptr_ptr)); 1477 1478 /* Free any memory associated with the png_struct and the png_info_structs */ 1479 PNG_EXPORT(65, void, png_destroy_write_struct, (png_structpp png_ptr_ptr, 1480 png_infopp info_ptr_ptr)); 1481 1482 /* Set the libpng method of handling chunk CRC errors */ 1483 PNG_EXPORT(66, void, png_set_crc_action, (png_structrp png_ptr, int crit_action, 1484 int ancil_action)); 1485 1486 /* Values for png_set_crc_action() say how to handle CRC errors in 1487 * ancillary and critical chunks, and whether to use the data contained 1488 * therein. Note that it is impossible to "discard" data in a critical 1489 * chunk. For versions prior to 0.90, the action was always error/quit, 1490 * whereas in version 0.90 and later, the action for CRC errors in ancillary 1491 * chunks is warn/discard. These values should NOT be changed. 1492 * 1493 * value action:critical action:ancillary 1494 */ 1495 #define PNG_CRC_DEFAULT 0 /* error/quit warn/discard data */ 1496 #define PNG_CRC_ERROR_QUIT 1 /* error/quit error/quit */ 1497 #define PNG_CRC_WARN_DISCARD 2 /* (INVALID) warn/discard data */ 1498 #define PNG_CRC_WARN_USE 3 /* warn/use data warn/use data */ 1499 #define PNG_CRC_QUIET_USE 4 /* quiet/use data quiet/use data */ 1500 #define PNG_CRC_NO_CHANGE 5 /* use current value use current value */ 1501 1502 #ifdef PNG_WRITE_SUPPORTED 1503 /* These functions give the user control over the scan-line filtering in 1504 * libpng and the compression methods used by zlib. These functions are 1505 * mainly useful for testing, as the defaults should work with most users. 1506 * Those users who are tight on memory or want faster performance at the 1507 * expense of compression can modify them. See the compression library 1508 * header file (zlib.h) for an explination of the compression functions. 1509 */ 1510 1511 /* Set the filtering method(s) used by libpng. Currently, the only valid 1512 * value for "method" is 0. 1513 */ 1514 PNG_EXPORT(67, void, png_set_filter, (png_structrp png_ptr, int method, 1515 int filters)); 1516 #endif /* WRITE */ 1517 1518 /* Flags for png_set_filter() to say which filters to use. The flags 1519 * are chosen so that they don't conflict with real filter types 1520 * below, in case they are supplied instead of the #defined constants. 1521 * These values should NOT be changed. 1522 */ 1523 #define PNG_NO_FILTERS 0x00 1524 #define PNG_FILTER_NONE 0x08 1525 #define PNG_FILTER_SUB 0x10 1526 #define PNG_FILTER_UP 0x20 1527 #define PNG_FILTER_AVG 0x40 1528 #define PNG_FILTER_PAETH 0x80 1529 #define PNG_FAST_FILTERS (PNG_FILTER_NONE | PNG_FILTER_SUB | PNG_FILTER_UP) 1530 #define PNG_ALL_FILTERS (PNG_FAST_FILTERS | PNG_FILTER_AVG | PNG_FILTER_PAETH) 1531 1532 /* Filter values (not flags) - used in pngwrite.c, pngwutil.c for now. 1533 * These defines should NOT be changed. 1534 */ 1535 #define PNG_FILTER_VALUE_NONE 0 1536 #define PNG_FILTER_VALUE_SUB 1 1537 #define PNG_FILTER_VALUE_UP 2 1538 #define PNG_FILTER_VALUE_AVG 3 1539 #define PNG_FILTER_VALUE_PAETH 4 1540 #define PNG_FILTER_VALUE_LAST 5 1541 1542 #ifdef PNG_WRITE_SUPPORTED 1543 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* DEPRECATED */ 1544 PNG_FP_EXPORT(68, void, png_set_filter_heuristics, (png_structrp png_ptr, 1545 int heuristic_method, int num_weights, png_const_doublep filter_weights, 1546 png_const_doublep filter_costs)) 1547 PNG_FIXED_EXPORT(209, void, png_set_filter_heuristics_fixed, 1548 (png_structrp png_ptr, int heuristic_method, int num_weights, 1549 png_const_fixed_point_p filter_weights, 1550 png_const_fixed_point_p filter_costs)) 1551 #endif /* WRITE_WEIGHTED_FILTER */ 1552 1553 /* The following are no longer used and will be removed from libpng-1.7: */ 1554 #define PNG_FILTER_HEURISTIC_DEFAULT 0 /* Currently "UNWEIGHTED" */ 1555 #define PNG_FILTER_HEURISTIC_UNWEIGHTED 1 /* Used by libpng < 0.95 */ 1556 #define PNG_FILTER_HEURISTIC_WEIGHTED 2 /* Experimental feature */ 1557 #define PNG_FILTER_HEURISTIC_LAST 3 /* Not a valid value */ 1558 1559 /* Set the library compression level. Currently, valid values range from 1560 * 0 - 9, corresponding directly to the zlib compression levels 0 - 9 1561 * (0 - no compression, 9 - "maximal" compression). Note that tests have 1562 * shown that zlib compression levels 3-6 usually perform as well as level 9 1563 * for PNG images, and do considerably fewer caclulations. In the future, 1564 * these values may not correspond directly to the zlib compression levels. 1565 */ 1566 #ifdef PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED 1567 PNG_EXPORT(69, void, png_set_compression_level, (png_structrp png_ptr, 1568 int level)); 1569 1570 PNG_EXPORT(70, void, png_set_compression_mem_level, (png_structrp png_ptr, 1571 int mem_level)); 1572 1573 PNG_EXPORT(71, void, png_set_compression_strategy, (png_structrp png_ptr, 1574 int strategy)); 1575 1576 /* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a 1577 * smaller value of window_bits if it can do so safely. 1578 */ 1579 PNG_EXPORT(72, void, png_set_compression_window_bits, (png_structrp png_ptr, 1580 int window_bits)); 1581 1582 PNG_EXPORT(73, void, png_set_compression_method, (png_structrp png_ptr, 1583 int method)); 1584 #endif /* WRITE_CUSTOMIZE_COMPRESSION */ 1585 1586 #ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED 1587 /* Also set zlib parameters for compressing non-IDAT chunks */ 1588 PNG_EXPORT(222, void, png_set_text_compression_level, (png_structrp png_ptr, 1589 int level)); 1590 1591 PNG_EXPORT(223, void, png_set_text_compression_mem_level, (png_structrp png_ptr, 1592 int mem_level)); 1593 1594 PNG_EXPORT(224, void, png_set_text_compression_strategy, (png_structrp png_ptr, 1595 int strategy)); 1596 1597 /* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a 1598 * smaller value of window_bits if it can do so safely. 1599 */ 1600 PNG_EXPORT(225, void, png_set_text_compression_window_bits, 1601 (png_structrp png_ptr, int window_bits)); 1602 1603 PNG_EXPORT(226, void, png_set_text_compression_method, (png_structrp png_ptr, 1604 int method)); 1605 #endif /* WRITE_CUSTOMIZE_ZTXT_COMPRESSION */ 1606 #endif /* WRITE */ 1607 1608 /* These next functions are called for input/output, memory, and error 1609 * handling. They are in the file pngrio.c, pngwio.c, and pngerror.c, 1610 * and call standard C I/O routines such as fread(), fwrite(), and 1611 * fprintf(). These functions can be made to use other I/O routines 1612 * at run time for those applications that need to handle I/O in a 1613 * different manner by calling png_set_???_fn(). See libpng-manual.txt for 1614 * more information. 1615 */ 1616 1617 #ifdef PNG_STDIO_SUPPORTED 1618 /* Initialize the input/output for the PNG file to the default functions. */ 1619 PNG_EXPORT(74, void, png_init_io, (png_structrp png_ptr, png_FILE_p fp)); 1620 #endif 1621 1622 /* Replace the (error and abort), and warning functions with user 1623 * supplied functions. If no messages are to be printed you must still 1624 * write and use replacement functions. The replacement error_fn should 1625 * still do a longjmp to the last setjmp location if you are using this 1626 * method of error handling. If error_fn or warning_fn is NULL, the 1627 * default function will be used. 1628 */ 1629 1630 PNG_EXPORT(75, void, png_set_error_fn, (png_structrp png_ptr, 1631 png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warning_fn)); 1632 1633 /* Return the user pointer associated with the error functions */ 1634 PNG_EXPORT(76, png_voidp, png_get_error_ptr, (png_const_structrp png_ptr)); 1635 1636 /* Replace the default data output functions with a user supplied one(s). 1637 * If buffered output is not used, then output_flush_fn can be set to NULL. 1638 * If PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile time 1639 * output_flush_fn will be ignored (and thus can be NULL). 1640 * It is probably a mistake to use NULL for output_flush_fn if 1641 * write_data_fn is not also NULL unless you have built libpng with 1642 * PNG_WRITE_FLUSH_SUPPORTED undefined, because in this case libpng's 1643 * default flush function, which uses the standard *FILE structure, will 1644 * be used. 1645 */ 1646 PNG_EXPORT(77, void, png_set_write_fn, (png_structrp png_ptr, png_voidp io_ptr, 1647 png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn)); 1648 1649 /* Replace the default data input function with a user supplied one. */ 1650 PNG_EXPORT(78, void, png_set_read_fn, (png_structrp png_ptr, png_voidp io_ptr, 1651 png_rw_ptr read_data_fn)); 1652 1653 /* Return the user pointer associated with the I/O functions */ 1654 PNG_EXPORT(79, png_voidp, png_get_io_ptr, (png_const_structrp png_ptr)); 1655 1656 PNG_EXPORT(80, void, png_set_read_status_fn, (png_structrp png_ptr, 1657 png_read_status_ptr read_row_fn)); 1658 1659 PNG_EXPORT(81, void, png_set_write_status_fn, (png_structrp png_ptr, 1660 png_write_status_ptr write_row_fn)); 1661 1662 #ifdef PNG_USER_MEM_SUPPORTED 1663 /* Replace the default memory allocation functions with user supplied one(s). */ 1664 PNG_EXPORT(82, void, png_set_mem_fn, (png_structrp png_ptr, png_voidp mem_ptr, 1665 png_malloc_ptr malloc_fn, png_free_ptr free_fn)); 1666 /* Return the user pointer associated with the memory functions */ 1667 PNG_EXPORT(83, png_voidp, png_get_mem_ptr, (png_const_structrp png_ptr)); 1668 #endif 1669 1670 #ifdef PNG_READ_USER_TRANSFORM_SUPPORTED 1671 PNG_EXPORT(84, void, png_set_read_user_transform_fn, (png_structrp png_ptr, 1672 png_user_transform_ptr read_user_transform_fn)); 1673 #endif 1674 1675 #ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED 1676 PNG_EXPORT(85, void, png_set_write_user_transform_fn, (png_structrp png_ptr, 1677 png_user_transform_ptr write_user_transform_fn)); 1678 #endif 1679 1680 #ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED 1681 PNG_EXPORT(86, void, png_set_user_transform_info, (png_structrp png_ptr, 1682 png_voidp user_transform_ptr, int user_transform_depth, 1683 int user_transform_channels)); 1684 /* Return the user pointer associated with the user transform functions */ 1685 PNG_EXPORT(87, png_voidp, png_get_user_transform_ptr, 1686 (png_const_structrp png_ptr)); 1687 #endif 1688 1689 #ifdef PNG_USER_TRANSFORM_INFO_SUPPORTED 1690 /* Return information about the row currently being processed. Note that these 1691 * APIs do not fail but will return unexpected results if called outside a user 1692 * transform callback. Also note that when transforming an interlaced image the 1693 * row number is the row number within the sub-image of the interlace pass, so 1694 * the value will increase to the height of the sub-image (not the full image) 1695 * then reset to 0 for the next pass. 1696 * 1697 * Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to 1698 * find the output pixel (x,y) given an interlaced sub-image pixel 1699 * (row,col,pass). (See below for these macros.) 1700 */ 1701 PNG_EXPORT(217, png_uint_32, png_get_current_row_number, (png_const_structrp)); 1702 PNG_EXPORT(218, png_byte, png_get_current_pass_number, (png_const_structrp)); 1703 #endif 1704 1705 #ifdef PNG_READ_USER_CHUNKS_SUPPORTED 1706 /* This callback is called only for *unknown* chunks. If 1707 * PNG_HANDLE_AS_UNKNOWN_SUPPORTED is set then it is possible to set known 1708 * chunks to be treated as unknown, however in this case the callback must do 1709 * any processing required by the chunk (e.g. by calling the appropriate 1710 * png_set_ APIs.) 1711 * 1712 * There is no write support - on write, by default, all the chunks in the 1713 * 'unknown' list are written in the specified position. 1714 * 1715 * The integer return from the callback function is interpreted thus: 1716 * 1717 * negative: An error occurred; png_chunk_error will be called. 1718 * zero: The chunk was not handled, the chunk will be saved. A critical 1719 * chunk will cause an error at this point unless it is to be saved. 1720 * positive: The chunk was handled, libpng will ignore/discard it. 1721 * 1722 * See "INTERACTION WTIH USER CHUNK CALLBACKS" below for important notes about 1723 * how this behavior will change in libpng 1.7 1724 */ 1725 PNG_EXPORT(88, void, png_set_read_user_chunk_fn, (png_structrp png_ptr, 1726 png_voidp user_chunk_ptr, png_user_chunk_ptr read_user_chunk_fn)); 1727 #endif 1728 1729 #ifdef PNG_USER_CHUNKS_SUPPORTED 1730 PNG_EXPORT(89, png_voidp, png_get_user_chunk_ptr, (png_const_structrp png_ptr)); 1731 #endif 1732 1733 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED 1734 /* Sets the function callbacks for the push reader, and a pointer to a 1735 * user-defined structure available to the callback functions. 1736 */ 1737 PNG_EXPORT(90, void, png_set_progressive_read_fn, (png_structrp png_ptr, 1738 png_voidp progressive_ptr, png_progressive_info_ptr info_fn, 1739 png_progressive_row_ptr row_fn, png_progressive_end_ptr end_fn)); 1740 1741 /* Returns the user pointer associated with the push read functions */ 1742 PNG_EXPORT(91, png_voidp, png_get_progressive_ptr, 1743 (png_const_structrp png_ptr)); 1744 1745 /* Function to be called when data becomes available */ 1746 PNG_EXPORT(92, void, png_process_data, (png_structrp png_ptr, 1747 png_inforp info_ptr, png_bytep buffer, png_size_t buffer_size)); 1748 1749 /* A function which may be called *only* within png_process_data to stop the 1750 * processing of any more data. The function returns the number of bytes 1751 * remaining, excluding any that libpng has cached internally. A subsequent 1752 * call to png_process_data must supply these bytes again. If the argument 1753 * 'save' is set to true the routine will first save all the pending data and 1754 * will always return 0. 1755 */ 1756 PNG_EXPORT(219, png_size_t, png_process_data_pause, (png_structrp, int save)); 1757 1758 /* A function which may be called *only* outside (after) a call to 1759 * png_process_data. It returns the number of bytes of data to skip in the 1760 * input. Normally it will return 0, but if it returns a non-zero value the 1761 * application must skip than number of bytes of input data and pass the 1762 * following data to the next call to png_process_data. 1763 */ 1764 PNG_EXPORT(220, png_uint_32, png_process_data_skip, (png_structrp)); 1765 1766 /* Function that combines rows. 'new_row' is a flag that should come from 1767 * the callback and be non-NULL if anything needs to be done; the library 1768 * stores its own version of the new data internally and ignores the passed 1769 * in value. 1770 */ 1771 PNG_EXPORT(93, void, png_progressive_combine_row, (png_const_structrp png_ptr, 1772 png_bytep old_row, png_const_bytep new_row)); 1773 #endif /* PROGRESSIVE_READ */ 1774 1775 PNG_EXPORTA(94, png_voidp, png_malloc, (png_const_structrp png_ptr, 1776 png_alloc_size_t size), PNG_ALLOCATED); 1777 /* Added at libpng version 1.4.0 */ 1778 PNG_EXPORTA(95, png_voidp, png_calloc, (png_const_structrp png_ptr, 1779 png_alloc_size_t size), PNG_ALLOCATED); 1780 1781 /* Added at libpng version 1.2.4 */ 1782 PNG_EXPORTA(96, png_voidp, png_malloc_warn, (png_const_structrp png_ptr, 1783 png_alloc_size_t size), PNG_ALLOCATED); 1784 1785 /* Frees a pointer allocated by png_malloc() */ 1786 PNG_EXPORT(97, void, png_free, (png_const_structrp png_ptr, png_voidp ptr)); 1787 1788 /* Free data that was allocated internally */ 1789 PNG_EXPORT(98, void, png_free_data, (png_const_structrp png_ptr, 1790 png_inforp info_ptr, png_uint_32 free_me, int num)); 1791 1792 /* Reassign responsibility for freeing existing data, whether allocated 1793 * by libpng or by the application; this works on the png_info structure passed 1794 * in, it does not change the state for other png_info structures. 1795 * 1796 * It is unlikely that this function works correctly as of 1.6.0 and using it 1797 * may result either in memory leaks or double free of allocated data. 1798 */ 1799 PNG_EXPORT(99, void, png_data_freer, (png_const_structrp png_ptr, 1800 png_inforp info_ptr, int freer, png_uint_32 mask)); 1801 1802 /* Assignments for png_data_freer */ 1803 #define PNG_DESTROY_WILL_FREE_DATA 1 1804 #define PNG_SET_WILL_FREE_DATA 1 1805 #define PNG_USER_WILL_FREE_DATA 2 1806 /* Flags for png_ptr->free_me and info_ptr->free_me */ 1807 #define PNG_FREE_HIST 0x0008U 1808 #define PNG_FREE_ICCP 0x0010U 1809 #define PNG_FREE_SPLT 0x0020U 1810 #define PNG_FREE_ROWS 0x0040U 1811 #define PNG_FREE_PCAL 0x0080U 1812 #define PNG_FREE_SCAL 0x0100U 1813 #ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED 1814 # define PNG_FREE_UNKN 0x0200U 1815 #endif 1816 /* PNG_FREE_LIST 0x0400U removed in 1.6.0 because it is ignored */ 1817 #define PNG_FREE_PLTE 0x1000U 1818 #define PNG_FREE_TRNS 0x2000U 1819 #define PNG_FREE_TEXT 0x4000U 1820 #define PNG_FREE_EXIF 0x8000U /* Added at libpng-1.6.31 */ 1821 #define PNG_FREE_ALL 0xffffU 1822 #define PNG_FREE_MUL 0x4220U /* PNG_FREE_SPLT|PNG_FREE_TEXT|PNG_FREE_UNKN */ 1823 1824 #ifdef PNG_USER_MEM_SUPPORTED 1825 PNG_EXPORTA(100, png_voidp, png_malloc_default, (png_const_structrp png_ptr, 1826 png_alloc_size_t size), PNG_ALLOCATED PNG_DEPRECATED); 1827 PNG_EXPORTA(101, void, png_free_default, (png_const_structrp png_ptr, 1828 png_voidp ptr), PNG_DEPRECATED); 1829 #endif 1830 1831 #ifdef PNG_ERROR_TEXT_SUPPORTED 1832 /* Fatal error in PNG image of libpng - can't continue */ 1833 PNG_EXPORTA(102, void, png_error, (png_const_structrp png_ptr, 1834 png_const_charp error_message), PNG_NORETURN); 1835 1836 /* The same, but the chunk name is prepended to the error string. */ 1837 PNG_EXPORTA(103, void, png_chunk_error, (png_const_structrp png_ptr, 1838 png_const_charp error_message), PNG_NORETURN); 1839 1840 #else 1841 /* Fatal error in PNG image of libpng - can't continue */ 1842 PNG_EXPORTA(104, void, png_err, (png_const_structrp png_ptr), PNG_NORETURN); 1843 # define png_error(s1,s2) png_err(s1) 1844 # define png_chunk_error(s1,s2) png_err(s1) 1845 #endif 1846 1847 #ifdef PNG_WARNINGS_SUPPORTED 1848 /* Non-fatal error in libpng. Can continue, but may have a problem. */ 1849 PNG_EXPORT(105, void, png_warning, (png_const_structrp png_ptr, 1850 png_const_charp warning_message)); 1851 1852 /* Non-fatal error in libpng, chunk name is prepended to message. */ 1853 PNG_EXPORT(106, void, png_chunk_warning, (png_const_structrp png_ptr, 1854 png_const_charp warning_message)); 1855 #else 1856 # define png_warning(s1,s2) ((void)(s1)) 1857 # define png_chunk_warning(s1,s2) ((void)(s1)) 1858 #endif 1859 1860 #ifdef PNG_BENIGN_ERRORS_SUPPORTED 1861 /* Benign error in libpng. Can continue, but may have a problem. 1862 * User can choose whether to handle as a fatal error or as a warning. */ 1863 PNG_EXPORT(107, void, png_benign_error, (png_const_structrp png_ptr, 1864 png_const_charp warning_message)); 1865 1866 #ifdef PNG_READ_SUPPORTED 1867 /* Same, chunk name is prepended to message (only during read) */ 1868 PNG_EXPORT(108, void, png_chunk_benign_error, (png_const_structrp png_ptr, 1869 png_const_charp warning_message)); 1870 #endif 1871 1872 PNG_EXPORT(109, void, png_set_benign_errors, 1873 (png_structrp png_ptr, int allowed)); 1874 #else 1875 # ifdef PNG_ALLOW_BENIGN_ERRORS 1876 # define png_benign_error png_warning 1877 # define png_chunk_benign_error png_chunk_warning 1878 # else 1879 # define png_benign_error png_error 1880 # define png_chunk_benign_error png_chunk_error 1881 # endif 1882 #endif 1883 1884 /* The png_set_<chunk> functions are for storing values in the png_info_struct. 1885 * Similarly, the png_get_<chunk> calls are used to read values from the 1886 * png_info_struct, either storing the parameters in the passed variables, or 1887 * setting pointers into the png_info_struct where the data is stored. The 1888 * png_get_<chunk> functions return a non-zero value if the data was available 1889 * in info_ptr, or return zero and do not change any of the parameters if the 1890 * data was not available. 1891 * 1892 * These functions should be used instead of directly accessing png_info 1893 * to avoid problems with future changes in the size and internal layout of 1894 * png_info_struct. 1895 */ 1896 /* Returns "flag" if chunk data is valid in info_ptr. */ 1897 PNG_EXPORT(110, png_uint_32, png_get_valid, (png_const_structrp png_ptr, 1898 png_const_inforp info_ptr, png_uint_32 flag)); 1899 1900 /* Returns number of bytes needed to hold a transformed row. */ 1901 PNG_EXPORT(111, png_size_t, png_get_rowbytes, (png_const_structrp png_ptr, 1902 png_const_inforp info_ptr)); 1903 1904 #ifdef PNG_INFO_IMAGE_SUPPORTED 1905 /* Returns row_pointers, which is an array of pointers to scanlines that was 1906 * returned from png_read_png(). 1907 */ 1908 PNG_EXPORT(112, png_bytepp, png_get_rows, (png_const_structrp png_ptr, 1909 png_const_inforp info_ptr)); 1910 1911 /* Set row_pointers, which is an array of pointers to scanlines for use 1912 * by png_write_png(). 1913 */ 1914 PNG_EXPORT(113, void, png_set_rows, (png_const_structrp png_ptr, 1915 png_inforp info_ptr, png_bytepp row_pointers)); 1916 #endif 1917 1918 /* Returns number of color channels in image. */ 1919 PNG_EXPORT(114, png_byte, png_get_channels, (png_const_structrp png_ptr, 1920 png_const_inforp info_ptr)); 1921 1922 #ifdef PNG_EASY_ACCESS_SUPPORTED 1923 /* Returns image width in pixels. */ 1924 PNG_EXPORT(115, png_uint_32, png_get_image_width, (png_const_structrp png_ptr, 1925 png_const_inforp info_ptr)); 1926 1927 /* Returns image height in pixels. */ 1928 PNG_EXPORT(116, png_uint_32, png_get_image_height, (png_const_structrp png_ptr, 1929 png_const_inforp info_ptr)); 1930 1931 /* Returns image bit_depth. */ 1932 PNG_EXPORT(117, png_byte, png_get_bit_depth, (png_const_structrp png_ptr, 1933 png_const_inforp info_ptr)); 1934 1935 /* Returns image color_type. */ 1936 PNG_EXPORT(118, png_byte, png_get_color_type, (png_const_structrp png_ptr, 1937 png_const_inforp info_ptr)); 1938 1939 /* Returns image filter_type. */ 1940 PNG_EXPORT(119, png_byte, png_get_filter_type, (png_const_structrp png_ptr, 1941 png_const_inforp info_ptr)); 1942 1943 /* Returns image interlace_type. */ 1944 PNG_EXPORT(120, png_byte, png_get_interlace_type, (png_const_structrp png_ptr, 1945 png_const_inforp info_ptr)); 1946 1947 /* Returns image compression_type. */ 1948 PNG_EXPORT(121, png_byte, png_get_compression_type, (png_const_structrp png_ptr, 1949 png_const_inforp info_ptr)); 1950 1951 /* Returns image resolution in pixels per meter, from pHYs chunk data. */ 1952 PNG_EXPORT(122, png_uint_32, png_get_pixels_per_meter, 1953 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 1954 PNG_EXPORT(123, png_uint_32, png_get_x_pixels_per_meter, 1955 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 1956 PNG_EXPORT(124, png_uint_32, png_get_y_pixels_per_meter, 1957 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 1958 1959 /* Returns pixel aspect ratio, computed from pHYs chunk data. */ 1960 PNG_FP_EXPORT(125, float, png_get_pixel_aspect_ratio, 1961 (png_const_structrp png_ptr, png_const_inforp info_ptr)) 1962 PNG_FIXED_EXPORT(210, png_fixed_point, png_get_pixel_aspect_ratio_fixed, 1963 (png_const_structrp png_ptr, png_const_inforp info_ptr)) 1964 1965 /* Returns image x, y offset in pixels or microns, from oFFs chunk data. */ 1966 PNG_EXPORT(126, png_int_32, png_get_x_offset_pixels, 1967 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 1968 PNG_EXPORT(127, png_int_32, png_get_y_offset_pixels, 1969 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 1970 PNG_EXPORT(128, png_int_32, png_get_x_offset_microns, 1971 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 1972 PNG_EXPORT(129, png_int_32, png_get_y_offset_microns, 1973 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 1974 1975 #endif /* EASY_ACCESS */ 1976 1977 #ifdef PNG_READ_SUPPORTED 1978 /* Returns pointer to signature string read from PNG header */ 1979 PNG_EXPORT(130, png_const_bytep, png_get_signature, (png_const_structrp png_ptr, 1980 png_const_inforp info_ptr)); 1981 #endif 1982 1983 #ifdef PNG_bKGD_SUPPORTED 1984 PNG_EXPORT(131, png_uint_32, png_get_bKGD, (png_const_structrp png_ptr, 1985 png_inforp info_ptr, png_color_16p *background)); 1986 #endif 1987 1988 #ifdef PNG_bKGD_SUPPORTED 1989 PNG_EXPORT(132, void, png_set_bKGD, (png_const_structrp png_ptr, 1990 png_inforp info_ptr, png_const_color_16p background)); 1991 #endif 1992 1993 #ifdef PNG_cHRM_SUPPORTED 1994 PNG_FP_EXPORT(133, png_uint_32, png_get_cHRM, (png_const_structrp png_ptr, 1995 png_const_inforp info_ptr, double *white_x, double *white_y, double *red_x, 1996 double *red_y, double *green_x, double *green_y, double *blue_x, 1997 double *blue_y)) 1998 PNG_FP_EXPORT(230, png_uint_32, png_get_cHRM_XYZ, (png_const_structrp png_ptr, 1999 png_const_inforp info_ptr, double *red_X, double *red_Y, double *red_Z, 2000 double *green_X, double *green_Y, double *green_Z, double *blue_X, 2001 double *blue_Y, double *blue_Z)) 2002 PNG_FIXED_EXPORT(134, png_uint_32, png_get_cHRM_fixed, 2003 (png_const_structrp png_ptr, png_const_inforp info_ptr, 2004 png_fixed_point *int_white_x, png_fixed_point *int_white_y, 2005 png_fixed_point *int_red_x, png_fixed_point *int_red_y, 2006 png_fixed_point *int_green_x, png_fixed_point *int_green_y, 2007 png_fixed_point *int_blue_x, png_fixed_point *int_blue_y)) 2008 PNG_FIXED_EXPORT(231, png_uint_32, png_get_cHRM_XYZ_fixed, 2009 (png_const_structrp png_ptr, png_const_inforp info_ptr, 2010 png_fixed_point *int_red_X, png_fixed_point *int_red_Y, 2011 png_fixed_point *int_red_Z, png_fixed_point *int_green_X, 2012 png_fixed_point *int_green_Y, png_fixed_point *int_green_Z, 2013 png_fixed_point *int_blue_X, png_fixed_point *int_blue_Y, 2014 png_fixed_point *int_blue_Z)) 2015 #endif 2016 2017 #ifdef PNG_cHRM_SUPPORTED 2018 PNG_FP_EXPORT(135, void, png_set_cHRM, (png_const_structrp png_ptr, 2019 png_inforp info_ptr, 2020 double white_x, double white_y, double red_x, double red_y, double green_x, 2021 double green_y, double blue_x, double blue_y)) 2022 PNG_FP_EXPORT(232, void, png_set_cHRM_XYZ, (png_const_structrp png_ptr, 2023 png_inforp info_ptr, double red_X, double red_Y, double red_Z, 2024 double green_X, double green_Y, double green_Z, double blue_X, 2025 double blue_Y, double blue_Z)) 2026 PNG_FIXED_EXPORT(136, void, png_set_cHRM_fixed, (png_const_structrp png_ptr, 2027 png_inforp info_ptr, png_fixed_point int_white_x, 2028 png_fixed_point int_white_y, png_fixed_point int_red_x, 2029 png_fixed_point int_red_y, png_fixed_point int_green_x, 2030 png_fixed_point int_green_y, png_fixed_point int_blue_x, 2031 png_fixed_point int_blue_y)) 2032 PNG_FIXED_EXPORT(233, void, png_set_cHRM_XYZ_fixed, (png_const_structrp png_ptr, 2033 png_inforp info_ptr, png_fixed_point int_red_X, png_fixed_point int_red_Y, 2034 png_fixed_point int_red_Z, png_fixed_point int_green_X, 2035 png_fixed_point int_green_Y, png_fixed_point int_green_Z, 2036 png_fixed_point int_blue_X, png_fixed_point int_blue_Y, 2037 png_fixed_point int_blue_Z)) 2038 #endif 2039 2040 #ifdef PNG_eXIf_SUPPORTED 2041 PNG_EXPORT(246, png_uint_32, png_get_eXIf, (png_const_structrp png_ptr, 2042 png_inforp info_ptr, png_bytep *exif)); 2043 PNG_EXPORT(247, void, png_set_eXIf, (png_const_structrp png_ptr, 2044 png_inforp info_ptr, const png_bytep exif)); 2045 2046 PNG_EXPORT(248, png_uint_32, png_get_eXIf_1, (png_const_structrp png_ptr, 2047 png_const_inforp info_ptr, png_uint_32 *num_exif, png_bytep *exif)); 2048 PNG_EXPORT(249, void, png_set_eXIf_1, (png_const_structrp png_ptr, 2049 png_inforp info_ptr, const png_uint_32 num_exif, const png_bytep exif)); 2050 #endif 2051 2052 #ifdef PNG_gAMA_SUPPORTED 2053 PNG_FP_EXPORT(137, png_uint_32, png_get_gAMA, (png_const_structrp png_ptr, 2054 png_const_inforp info_ptr, double *file_gamma)) 2055 PNG_FIXED_EXPORT(138, png_uint_32, png_get_gAMA_fixed, 2056 (png_const_structrp png_ptr, png_const_inforp info_ptr, 2057 png_fixed_point *int_file_gamma)) 2058 #endif 2059 2060 #ifdef PNG_gAMA_SUPPORTED 2061 PNG_FP_EXPORT(139, void, png_set_gAMA, (png_const_structrp png_ptr, 2062 png_inforp info_ptr, double file_gamma)) 2063 PNG_FIXED_EXPORT(140, void, png_set_gAMA_fixed, (png_const_structrp png_ptr, 2064 png_inforp info_ptr, png_fixed_point int_file_gamma)) 2065 #endif 2066 2067 #ifdef PNG_hIST_SUPPORTED 2068 PNG_EXPORT(141, png_uint_32, png_get_hIST, (png_const_structrp png_ptr, 2069 png_inforp info_ptr, png_uint_16p *hist)); 2070 PNG_EXPORT(142, void, png_set_hIST, (png_const_structrp png_ptr, 2071 png_inforp info_ptr, png_const_uint_16p hist)); 2072 #endif 2073 2074 PNG_EXPORT(143, png_uint_32, png_get_IHDR, (png_const_structrp png_ptr, 2075 png_const_inforp info_ptr, png_uint_32 *width, png_uint_32 *height, 2076 int *bit_depth, int *color_type, int *interlace_method, 2077 int *compression_method, int *filter_method)); 2078 2079 PNG_EXPORT(144, void, png_set_IHDR, (png_const_structrp png_ptr, 2080 png_inforp info_ptr, png_uint_32 width, png_uint_32 height, int bit_depth, 2081 int color_type, int interlace_method, int compression_method, 2082 int filter_method)); 2083 2084 #ifdef PNG_oFFs_SUPPORTED 2085 PNG_EXPORT(145, png_uint_32, png_get_oFFs, (png_const_structrp png_ptr, 2086 png_const_inforp info_ptr, png_int_32 *offset_x, png_int_32 *offset_y, 2087 int *unit_type)); 2088 #endif 2089 2090 #ifdef PNG_oFFs_SUPPORTED 2091 PNG_EXPORT(146, void, png_set_oFFs, (png_const_structrp png_ptr, 2092 png_inforp info_ptr, png_int_32 offset_x, png_int_32 offset_y, 2093 int unit_type)); 2094 #endif 2095 2096 #ifdef PNG_pCAL_SUPPORTED 2097 PNG_EXPORT(147, png_uint_32, png_get_pCAL, (png_const_structrp png_ptr, 2098 png_inforp info_ptr, png_charp *purpose, png_int_32 *X0, 2099 png_int_32 *X1, int *type, int *nparams, png_charp *units, 2100 png_charpp *params)); 2101 #endif 2102 2103 #ifdef PNG_pCAL_SUPPORTED 2104 PNG_EXPORT(148, void, png_set_pCAL, (png_const_structrp png_ptr, 2105 png_inforp info_ptr, png_const_charp purpose, png_int_32 X0, png_int_32 X1, 2106 int type, int nparams, png_const_charp units, png_charpp params)); 2107 #endif 2108 2109 #ifdef PNG_pHYs_SUPPORTED 2110 PNG_EXPORT(149, png_uint_32, png_get_pHYs, (png_const_structrp png_ptr, 2111 png_const_inforp info_ptr, png_uint_32 *res_x, png_uint_32 *res_y, 2112 int *unit_type)); 2113 #endif 2114 2115 #ifdef PNG_pHYs_SUPPORTED 2116 PNG_EXPORT(150, void, png_set_pHYs, (png_const_structrp png_ptr, 2117 png_inforp info_ptr, png_uint_32 res_x, png_uint_32 res_y, int unit_type)); 2118 #endif 2119 2120 PNG_EXPORT(151, png_uint_32, png_get_PLTE, (png_const_structrp png_ptr, 2121 png_inforp info_ptr, png_colorp *palette, int *num_palette)); 2122 2123 PNG_EXPORT(152, void, png_set_PLTE, (png_structrp png_ptr, 2124 png_inforp info_ptr, png_const_colorp palette, int num_palette)); 2125 2126 #ifdef PNG_sBIT_SUPPORTED 2127 PNG_EXPORT(153, png_uint_32, png_get_sBIT, (png_const_structrp png_ptr, 2128 png_inforp info_ptr, png_color_8p *sig_bit)); 2129 #endif 2130 2131 #ifdef PNG_sBIT_SUPPORTED 2132 PNG_EXPORT(154, void, png_set_sBIT, (png_const_structrp png_ptr, 2133 png_inforp info_ptr, png_const_color_8p sig_bit)); 2134 #endif 2135 2136 #ifdef PNG_sRGB_SUPPORTED 2137 PNG_EXPORT(155, png_uint_32, png_get_sRGB, (png_const_structrp png_ptr, 2138 png_const_inforp info_ptr, int *file_srgb_intent)); 2139 #endif 2140 2141 #ifdef PNG_sRGB_SUPPORTED 2142 PNG_EXPORT(156, void, png_set_sRGB, (png_const_structrp png_ptr, 2143 png_inforp info_ptr, int srgb_intent)); 2144 PNG_EXPORT(157, void, png_set_sRGB_gAMA_and_cHRM, (png_const_structrp png_ptr, 2145 png_inforp info_ptr, int srgb_intent)); 2146 #endif 2147 2148 #ifdef PNG_iCCP_SUPPORTED 2149 PNG_EXPORT(158, png_uint_32, png_get_iCCP, (png_const_structrp png_ptr, 2150 png_inforp info_ptr, png_charpp name, int *compression_type, 2151 png_bytepp profile, png_uint_32 *proflen)); 2152 #endif 2153 2154 #ifdef PNG_iCCP_SUPPORTED 2155 PNG_EXPORT(159, void, png_set_iCCP, (png_const_structrp png_ptr, 2156 png_inforp info_ptr, png_const_charp name, int compression_type, 2157 png_const_bytep profile, png_uint_32 proflen)); 2158 #endif 2159 2160 #ifdef PNG_sPLT_SUPPORTED 2161 PNG_EXPORT(160, int, png_get_sPLT, (png_const_structrp png_ptr, 2162 png_inforp info_ptr, png_sPLT_tpp entries)); 2163 #endif 2164 2165 #ifdef PNG_sPLT_SUPPORTED 2166 PNG_EXPORT(161, void, png_set_sPLT, (png_const_structrp png_ptr, 2167 png_inforp info_ptr, png_const_sPLT_tp entries, int nentries)); 2168 #endif 2169 2170 #ifdef PNG_TEXT_SUPPORTED 2171 /* png_get_text also returns the number of text chunks in *num_text */ 2172 PNG_EXPORT(162, int, png_get_text, (png_const_structrp png_ptr, 2173 png_inforp info_ptr, png_textp *text_ptr, int *num_text)); 2174 #endif 2175 2176 /* Note while png_set_text() will accept a structure whose text, 2177 * language, and translated keywords are NULL pointers, the structure 2178 * returned by png_get_text will always contain regular 2179 * zero-terminated C strings. They might be empty strings but 2180 * they will never be NULL pointers. 2181 */ 2182 2183 #ifdef PNG_TEXT_SUPPORTED 2184 PNG_EXPORT(163, void, png_set_text, (png_const_structrp png_ptr, 2185 png_inforp info_ptr, png_const_textp text_ptr, int num_text)); 2186 #endif 2187 2188 #ifdef PNG_tIME_SUPPORTED 2189 PNG_EXPORT(164, png_uint_32, png_get_tIME, (png_const_structrp png_ptr, 2190 png_inforp info_ptr, png_timep *mod_time)); 2191 #endif 2192 2193 #ifdef PNG_tIME_SUPPORTED 2194 PNG_EXPORT(165, void, png_set_tIME, (png_const_structrp png_ptr, 2195 png_inforp info_ptr, png_const_timep mod_time)); 2196 #endif 2197 2198 #ifdef PNG_tRNS_SUPPORTED 2199 PNG_EXPORT(166, png_uint_32, png_get_tRNS, (png_const_structrp png_ptr, 2200 png_inforp info_ptr, png_bytep *trans_alpha, int *num_trans, 2201 png_color_16p *trans_color)); 2202 #endif 2203 2204 #ifdef PNG_tRNS_SUPPORTED 2205 PNG_EXPORT(167, void, png_set_tRNS, (png_structrp png_ptr, 2206 png_inforp info_ptr, png_const_bytep trans_alpha, int num_trans, 2207 png_const_color_16p trans_color)); 2208 #endif 2209 2210 #ifdef PNG_sCAL_SUPPORTED 2211 PNG_FP_EXPORT(168, png_uint_32, png_get_sCAL, (png_const_structrp png_ptr, 2212 png_const_inforp info_ptr, int *unit, double *width, double *height)) 2213 #if defined(PNG_FLOATING_ARITHMETIC_SUPPORTED) || \ 2214 defined(PNG_FLOATING_POINT_SUPPORTED) 2215 /* NOTE: this API is currently implemented using floating point arithmetic, 2216 * consequently it can only be used on systems with floating point support. 2217 * In any case the range of values supported by png_fixed_point is small and it 2218 * is highly recommended that png_get_sCAL_s be used instead. 2219 */ 2220 PNG_FIXED_EXPORT(214, png_uint_32, png_get_sCAL_fixed, 2221 (png_const_structrp png_ptr, png_const_inforp info_ptr, int *unit, 2222 png_fixed_point *width, png_fixed_point *height)) 2223 #endif 2224 PNG_EXPORT(169, png_uint_32, png_get_sCAL_s, 2225 (png_const_structrp png_ptr, png_const_inforp info_ptr, int *unit, 2226 png_charpp swidth, png_charpp sheight)); 2227 2228 PNG_FP_EXPORT(170, void, png_set_sCAL, (png_const_structrp png_ptr, 2229 png_inforp info_ptr, int unit, double width, double height)) 2230 PNG_FIXED_EXPORT(213, void, png_set_sCAL_fixed, (png_const_structrp png_ptr, 2231 png_inforp info_ptr, int unit, png_fixed_point width, 2232 png_fixed_point height)) 2233 PNG_EXPORT(171, void, png_set_sCAL_s, (png_const_structrp png_ptr, 2234 png_inforp info_ptr, int unit, 2235 png_const_charp swidth, png_const_charp sheight)); 2236 #endif /* sCAL */ 2237 2238 #ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED 2239 /* Provide the default handling for all unknown chunks or, optionally, for 2240 * specific unknown chunks. 2241 * 2242 * NOTE: prior to 1.6.0 the handling specified for particular chunks on read was 2243 * ignored and the default was used, the per-chunk setting only had an effect on 2244 * write. If you wish to have chunk-specific handling on read in code that must 2245 * work on earlier versions you must use a user chunk callback to specify the 2246 * desired handling (keep or discard.) 2247 * 2248 * The 'keep' parameter is a PNG_HANDLE_CHUNK_ value as listed below. The 2249 * parameter is interpreted as follows: 2250 * 2251 * READ: 2252 * PNG_HANDLE_CHUNK_AS_DEFAULT: 2253 * Known chunks: do normal libpng processing, do not keep the chunk (but 2254 * see the comments below about PNG_HANDLE_AS_UNKNOWN_SUPPORTED) 2255 * Unknown chunks: for a specific chunk use the global default, when used 2256 * as the default discard the chunk data. 2257 * PNG_HANDLE_CHUNK_NEVER: 2258 * Discard the chunk data. 2259 * PNG_HANDLE_CHUNK_IF_SAFE: 2260 * Keep the chunk data if the chunk is not critical else raise a chunk 2261 * error. 2262 * PNG_HANDLE_CHUNK_ALWAYS: 2263 * Keep the chunk data. 2264 * 2265 * If the chunk data is saved it can be retrieved using png_get_unknown_chunks, 2266 * below. Notice that specifying "AS_DEFAULT" as a global default is equivalent 2267 * to specifying "NEVER", however when "AS_DEFAULT" is used for specific chunks 2268 * it simply resets the behavior to the libpng default. 2269 * 2270 * INTERACTION WTIH USER CHUNK CALLBACKS: 2271 * The per-chunk handling is always used when there is a png_user_chunk_ptr 2272 * callback and the callback returns 0; the chunk is then always stored *unless* 2273 * it is critical and the per-chunk setting is other than ALWAYS. Notice that 2274 * the global default is *not* used in this case. (In effect the per-chunk 2275 * value is incremented to at least IF_SAFE.) 2276 * 2277 * IMPORTANT NOTE: this behavior will change in libpng 1.7 - the global and 2278 * per-chunk defaults will be honored. If you want to preserve the current 2279 * behavior when your callback returns 0 you must set PNG_HANDLE_CHUNK_IF_SAFE 2280 * as the default - if you don't do this libpng 1.6 will issue a warning. 2281 * 2282 * If you want unhandled unknown chunks to be discarded in libpng 1.6 and 2283 * earlier simply return '1' (handled). 2284 * 2285 * PNG_HANDLE_AS_UNKNOWN_SUPPORTED: 2286 * If this is *not* set known chunks will always be handled by libpng and 2287 * will never be stored in the unknown chunk list. Known chunks listed to 2288 * png_set_keep_unknown_chunks will have no effect. If it is set then known 2289 * chunks listed with a keep other than AS_DEFAULT will *never* be processed 2290 * by libpng, in addition critical chunks must either be processed by the 2291 * callback or saved. 2292 * 2293 * The IHDR and IEND chunks must not be listed. Because this turns off the 2294 * default handling for chunks that would otherwise be recognized the 2295 * behavior of libpng transformations may well become incorrect! 2296 * 2297 * WRITE: 2298 * When writing chunks the options only apply to the chunks specified by 2299 * png_set_unknown_chunks (below), libpng will *always* write known chunks 2300 * required by png_set_ calls and will always write the core critical chunks 2301 * (as required for PLTE). 2302 * 2303 * Each chunk in the png_set_unknown_chunks list is looked up in the 2304 * png_set_keep_unknown_chunks list to find the keep setting, this is then 2305 * interpreted as follows: 2306 * 2307 * PNG_HANDLE_CHUNK_AS_DEFAULT: 2308 * Write safe-to-copy chunks and write other chunks if the global 2309 * default is set to _ALWAYS, otherwise don't write this chunk. 2310 * PNG_HANDLE_CHUNK_NEVER: 2311 * Do not write the chunk. 2312 * PNG_HANDLE_CHUNK_IF_SAFE: 2313 * Write the chunk if it is safe-to-copy, otherwise do not write it. 2314 * PNG_HANDLE_CHUNK_ALWAYS: 2315 * Write the chunk. 2316 * 2317 * Note that the default behavior is effectively the opposite of the read case - 2318 * in read unknown chunks are not stored by default, in write they are written 2319 * by default. Also the behavior of PNG_HANDLE_CHUNK_IF_SAFE is very different 2320 * - on write the safe-to-copy bit is checked, on read the critical bit is 2321 * checked and on read if the chunk is critical an error will be raised. 2322 * 2323 * num_chunks: 2324 * =========== 2325 * If num_chunks is positive, then the "keep" parameter specifies the manner 2326 * for handling only those chunks appearing in the chunk_list array, 2327 * otherwise the chunk list array is ignored. 2328 * 2329 * If num_chunks is 0 the "keep" parameter specifies the default behavior for 2330 * unknown chunks, as described above. 2331 * 2332 * If num_chunks is negative, then the "keep" parameter specifies the manner 2333 * for handling all unknown chunks plus all chunks recognized by libpng 2334 * except for the IHDR, PLTE, tRNS, IDAT, and IEND chunks (which continue to 2335 * be processed by libpng. 2336 */ 2337 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED 2338 PNG_EXPORT(172, void, png_set_keep_unknown_chunks, (png_structrp png_ptr, 2339 int keep, png_const_bytep chunk_list, int num_chunks)); 2340 #endif /* HANDLE_AS_UNKNOWN */ 2341 2342 /* The "keep" PNG_HANDLE_CHUNK_ parameter for the specified chunk is returned; 2343 * the result is therefore true (non-zero) if special handling is required, 2344 * false for the default handling. 2345 */ 2346 PNG_EXPORT(173, int, png_handle_as_unknown, (png_const_structrp png_ptr, 2347 png_const_bytep chunk_name)); 2348 #endif /* SET_UNKNOWN_CHUNKS */ 2349 2350 #ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED 2351 PNG_EXPORT(174, void, png_set_unknown_chunks, (png_const_structrp png_ptr, 2352 png_inforp info_ptr, png_const_unknown_chunkp unknowns, 2353 int num_unknowns)); 2354 /* NOTE: prior to 1.6.0 this routine set the 'location' field of the added 2355 * unknowns to the location currently stored in the png_struct. This is 2356 * invariably the wrong value on write. To fix this call the following API 2357 * for each chunk in the list with the correct location. If you know your 2358 * code won't be compiled on earlier versions you can rely on 2359 * png_set_unknown_chunks(write-ptr, png_get_unknown_chunks(read-ptr)) doing 2360 * the correct thing. 2361 */ 2362 2363 PNG_EXPORT(175, void, png_set_unknown_chunk_location, 2364 (png_const_structrp png_ptr, png_inforp info_ptr, int chunk, int location)); 2365 2366 PNG_EXPORT(176, int, png_get_unknown_chunks, (png_const_structrp png_ptr, 2367 png_inforp info_ptr, png_unknown_chunkpp entries)); 2368 #endif 2369 2370 /* Png_free_data() will turn off the "valid" flag for anything it frees. 2371 * If you need to turn it off for a chunk that your application has freed, 2372 * you can use png_set_invalid(png_ptr, info_ptr, PNG_INFO_CHNK); 2373 */ 2374 PNG_EXPORT(177, void, png_set_invalid, (png_const_structrp png_ptr, 2375 png_inforp info_ptr, int mask)); 2376 2377 #ifdef PNG_INFO_IMAGE_SUPPORTED 2378 /* The "params" pointer is currently not used and is for future expansion. */ 2379 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED 2380 PNG_EXPORT(178, void, png_read_png, (png_structrp png_ptr, png_inforp info_ptr, 2381 int transforms, png_voidp params)); 2382 #endif 2383 #ifdef PNG_WRITE_SUPPORTED 2384 PNG_EXPORT(179, void, png_write_png, (png_structrp png_ptr, png_inforp info_ptr, 2385 int transforms, png_voidp params)); 2386 #endif 2387 #endif 2388 2389 PNG_EXPORT(180, png_const_charp, png_get_copyright, 2390 (png_const_structrp png_ptr)); 2391 PNG_EXPORT(181, png_const_charp, png_get_header_ver, 2392 (png_const_structrp png_ptr)); 2393 PNG_EXPORT(182, png_const_charp, png_get_header_version, 2394 (png_const_structrp png_ptr)); 2395 PNG_EXPORT(183, png_const_charp, png_get_libpng_ver, 2396 (png_const_structrp png_ptr)); 2397 2398 #ifdef PNG_MNG_FEATURES_SUPPORTED 2399 PNG_EXPORT(184, png_uint_32, png_permit_mng_features, (png_structrp png_ptr, 2400 png_uint_32 mng_features_permitted)); 2401 #endif 2402 2403 /* For use in png_set_keep_unknown, added to version 1.2.6 */ 2404 #define PNG_HANDLE_CHUNK_AS_DEFAULT 0 2405 #define PNG_HANDLE_CHUNK_NEVER 1 2406 #define PNG_HANDLE_CHUNK_IF_SAFE 2 2407 #define PNG_HANDLE_CHUNK_ALWAYS 3 2408 #define PNG_HANDLE_CHUNK_LAST 4 2409 2410 /* Strip the prepended error numbers ("#nnn ") from error and warning 2411 * messages before passing them to the error or warning handler. 2412 */ 2413 #ifdef PNG_ERROR_NUMBERS_SUPPORTED 2414 PNG_EXPORT(185, void, png_set_strip_error_numbers, (png_structrp png_ptr, 2415 png_uint_32 strip_mode)); 2416 #endif 2417 2418 /* Added in libpng-1.2.6 */ 2419 #ifdef PNG_SET_USER_LIMITS_SUPPORTED 2420 PNG_EXPORT(186, void, png_set_user_limits, (png_structrp png_ptr, 2421 png_uint_32 user_width_max, png_uint_32 user_height_max)); 2422 PNG_EXPORT(187, png_uint_32, png_get_user_width_max, 2423 (png_const_structrp png_ptr)); 2424 PNG_EXPORT(188, png_uint_32, png_get_user_height_max, 2425 (png_const_structrp png_ptr)); 2426 /* Added in libpng-1.4.0 */ 2427 PNG_EXPORT(189, void, png_set_chunk_cache_max, (png_structrp png_ptr, 2428 png_uint_32 user_chunk_cache_max)); 2429 PNG_EXPORT(190, png_uint_32, png_get_chunk_cache_max, 2430 (png_const_structrp png_ptr)); 2431 /* Added in libpng-1.4.1 */ 2432 PNG_EXPORT(191, void, png_set_chunk_malloc_max, (png_structrp png_ptr, 2433 png_alloc_size_t user_chunk_cache_max)); 2434 PNG_EXPORT(192, png_alloc_size_t, png_get_chunk_malloc_max, 2435 (png_const_structrp png_ptr)); 2436 #endif 2437 2438 #if defined(PNG_INCH_CONVERSIONS_SUPPORTED) 2439 PNG_EXPORT(193, png_uint_32, png_get_pixels_per_inch, 2440 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 2441 2442 PNG_EXPORT(194, png_uint_32, png_get_x_pixels_per_inch, 2443 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 2444 2445 PNG_EXPORT(195, png_uint_32, png_get_y_pixels_per_inch, 2446 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 2447 2448 PNG_FP_EXPORT(196, float, png_get_x_offset_inches, 2449 (png_const_structrp png_ptr, png_const_inforp info_ptr)) 2450 #ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */ 2451 PNG_FIXED_EXPORT(211, png_fixed_point, png_get_x_offset_inches_fixed, 2452 (png_const_structrp png_ptr, png_const_inforp info_ptr)) 2453 #endif 2454 2455 PNG_FP_EXPORT(197, float, png_get_y_offset_inches, (png_const_structrp png_ptr, 2456 png_const_inforp info_ptr)) 2457 #ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */ 2458 PNG_FIXED_EXPORT(212, png_fixed_point, png_get_y_offset_inches_fixed, 2459 (png_const_structrp png_ptr, png_const_inforp info_ptr)) 2460 #endif 2461 2462 # ifdef PNG_pHYs_SUPPORTED 2463 PNG_EXPORT(198, png_uint_32, png_get_pHYs_dpi, (png_const_structrp png_ptr, 2464 png_const_inforp info_ptr, png_uint_32 *res_x, png_uint_32 *res_y, 2465 int *unit_type)); 2466 # endif /* pHYs */ 2467 #endif /* INCH_CONVERSIONS */ 2468 2469 /* Added in libpng-1.4.0 */ 2470 #ifdef PNG_IO_STATE_SUPPORTED 2471 PNG_EXPORT(199, png_uint_32, png_get_io_state, (png_const_structrp png_ptr)); 2472 2473 /* Removed from libpng 1.6; use png_get_io_chunk_type. */ 2474 PNG_REMOVED(200, png_const_bytep, png_get_io_chunk_name, (png_structrp png_ptr), 2475 PNG_DEPRECATED) 2476 2477 PNG_EXPORT(216, png_uint_32, png_get_io_chunk_type, 2478 (png_const_structrp png_ptr)); 2479 2480 /* The flags returned by png_get_io_state() are the following: */ 2481 # define PNG_IO_NONE 0x0000 /* no I/O at this moment */ 2482 # define PNG_IO_READING 0x0001 /* currently reading */ 2483 # define PNG_IO_WRITING 0x0002 /* currently writing */ 2484 # define PNG_IO_SIGNATURE 0x0010 /* currently at the file signature */ 2485 # define PNG_IO_CHUNK_HDR 0x0020 /* currently at the chunk header */ 2486 # define PNG_IO_CHUNK_DATA 0x0040 /* currently at the chunk data */ 2487 # define PNG_IO_CHUNK_CRC 0x0080 /* currently at the chunk crc */ 2488 # define PNG_IO_MASK_OP 0x000f /* current operation: reading/writing */ 2489 # define PNG_IO_MASK_LOC 0x00f0 /* current location: sig/hdr/data/crc */ 2490 #endif /* IO_STATE */ 2491 2492 /* Interlace support. The following macros are always defined so that if 2493 * libpng interlace handling is turned off the macros may be used to handle 2494 * interlaced images within the application. 2495 */ 2496 #define PNG_INTERLACE_ADAM7_PASSES 7 2497 2498 /* Two macros to return the first row and first column of the original, 2499 * full, image which appears in a given pass. 'pass' is in the range 0 2500 * to 6 and the result is in the range 0 to 7. 2501 */ 2502 #define PNG_PASS_START_ROW(pass) (((1&~(pass))<<(3-((pass)>>1)))&7) 2503 #define PNG_PASS_START_COL(pass) (((1& (pass))<<(3-(((pass)+1)>>1)))&7) 2504 2505 /* A macro to return the offset between pixels in the output row for a pair of 2506 * pixels in the input - effectively the inverse of the 'COL_SHIFT' macro that 2507 * follows. Note that ROW_OFFSET is the offset from one row to the next whereas 2508 * COL_OFFSET is from one column to the next, within a row. 2509 */ 2510 #define PNG_PASS_ROW_OFFSET(pass) ((pass)>2?(8>>(((pass)-1)>>1)):8) 2511 #define PNG_PASS_COL_OFFSET(pass) (1<<((7-(pass))>>1)) 2512 2513 /* Two macros to help evaluate the number of rows or columns in each 2514 * pass. This is expressed as a shift - effectively log2 of the number or 2515 * rows or columns in each 8x8 tile of the original image. 2516 */ 2517 #define PNG_PASS_ROW_SHIFT(pass) ((pass)>2?(8-(pass))>>1:3) 2518 #define PNG_PASS_COL_SHIFT(pass) ((pass)>1?(7-(pass))>>1:3) 2519 2520 /* Hence two macros to determine the number of rows or columns in a given 2521 * pass of an image given its height or width. In fact these macros may 2522 * return non-zero even though the sub-image is empty, because the other 2523 * dimension may be empty for a small image. 2524 */ 2525 #define PNG_PASS_ROWS(height, pass) (((height)+(((1<<PNG_PASS_ROW_SHIFT(pass))\ 2526 -1)-PNG_PASS_START_ROW(pass)))>>PNG_PASS_ROW_SHIFT(pass)) 2527 #define PNG_PASS_COLS(width, pass) (((width)+(((1<<PNG_PASS_COL_SHIFT(pass))\ 2528 -1)-PNG_PASS_START_COL(pass)))>>PNG_PASS_COL_SHIFT(pass)) 2529 2530 /* For the reader row callbacks (both progressive and sequential) it is 2531 * necessary to find the row in the output image given a row in an interlaced 2532 * image, so two more macros: 2533 */ 2534 #define PNG_ROW_FROM_PASS_ROW(y_in, pass) \ 2535 (((y_in)<<PNG_PASS_ROW_SHIFT(pass))+PNG_PASS_START_ROW(pass)) 2536 #define PNG_COL_FROM_PASS_COL(x_in, pass) \ 2537 (((x_in)<<PNG_PASS_COL_SHIFT(pass))+PNG_PASS_START_COL(pass)) 2538 2539 /* Two macros which return a boolean (0 or 1) saying whether the given row 2540 * or column is in a particular pass. These use a common utility macro that 2541 * returns a mask for a given pass - the offset 'off' selects the row or 2542 * column version. The mask has the appropriate bit set for each column in 2543 * the tile. 2544 */ 2545 #define PNG_PASS_MASK(pass,off) ( \ 2546 ((0x110145AF>>(((7-(off))-(pass))<<2)) & 0xF) | \ 2547 ((0x01145AF0>>(((7-(off))-(pass))<<2)) & 0xF0)) 2548 2549 #define PNG_ROW_IN_INTERLACE_PASS(y, pass) \ 2550 ((PNG_PASS_MASK(pass,0) >> ((y)&7)) & 1) 2551 #define PNG_COL_IN_INTERLACE_PASS(x, pass) \ 2552 ((PNG_PASS_MASK(pass,1) >> ((x)&7)) & 1) 2553 2554 #ifdef PNG_READ_COMPOSITE_NODIV_SUPPORTED 2555 /* With these routines we avoid an integer divide, which will be slower on 2556 * most machines. However, it does take more operations than the corresponding 2557 * divide method, so it may be slower on a few RISC systems. There are two 2558 * shifts (by 8 or 16 bits) and an addition, versus a single integer divide. 2559 * 2560 * Note that the rounding factors are NOT supposed to be the same! 128 and 2561 * 32768 are correct for the NODIV code; 127 and 32767 are correct for the 2562 * standard method. 2563 * 2564 * [Optimized code by Greg Roelofs and Mark Adler...blame us for bugs. :-) ] 2565 */ 2566 2567 /* fg and bg should be in `gamma 1.0' space; alpha is the opacity */ 2568 2569 # define png_composite(composite, fg, alpha, bg) \ 2570 { \ 2571 png_uint_16 temp = (png_uint_16)((png_uint_16)(fg) \ 2572 * (png_uint_16)(alpha) \ 2573 + (png_uint_16)(bg)*(png_uint_16)(255 \ 2574 - (png_uint_16)(alpha)) + 128); \ 2575 (composite) = (png_byte)(((temp + (temp >> 8)) >> 8) & 0xff); \ 2576 } 2577 2578 # define png_composite_16(composite, fg, alpha, bg) \ 2579 { \ 2580 png_uint_32 temp = (png_uint_32)((png_uint_32)(fg) \ 2581 * (png_uint_32)(alpha) \ 2582 + (png_uint_32)(bg)*(65535 \ 2583 - (png_uint_32)(alpha)) + 32768); \ 2584 (composite) = (png_uint_16)(0xffff & ((temp + (temp >> 16)) >> 16)); \ 2585 } 2586 2587 #else /* Standard method using integer division */ 2588 2589 # define png_composite(composite, fg, alpha, bg) \ 2590 (composite) = \ 2591 (png_byte)(0xff & (((png_uint_16)(fg) * (png_uint_16)(alpha) + \ 2592 (png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) + \ 2593 127) / 255)) 2594 2595 # define png_composite_16(composite, fg, alpha, bg) \ 2596 (composite) = \ 2597 (png_uint_16)(0xffff & (((png_uint_32)(fg) * (png_uint_32)(alpha) + \ 2598 (png_uint_32)(bg)*(png_uint_32)(65535 - (png_uint_32)(alpha)) + \ 2599 32767) / 65535)) 2600 #endif /* READ_COMPOSITE_NODIV */ 2601 2602 #ifdef PNG_READ_INT_FUNCTIONS_SUPPORTED 2603 PNG_EXPORT(201, png_uint_32, png_get_uint_32, (png_const_bytep buf)); 2604 PNG_EXPORT(202, png_uint_16, png_get_uint_16, (png_const_bytep buf)); 2605 PNG_EXPORT(203, png_int_32, png_get_int_32, (png_const_bytep buf)); 2606 #endif 2607 2608 PNG_EXPORT(204, png_uint_32, png_get_uint_31, (png_const_structrp png_ptr, 2609 png_const_bytep buf)); 2610 /* No png_get_int_16 -- may be added if there's a real need for it. */ 2611 2612 /* Place a 32-bit number into a buffer in PNG byte order (big-endian). */ 2613 #ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED 2614 PNG_EXPORT(205, void, png_save_uint_32, (png_bytep buf, png_uint_32 i)); 2615 #endif 2616 #ifdef PNG_SAVE_INT_32_SUPPORTED 2617 PNG_EXPORT(206, void, png_save_int_32, (png_bytep buf, png_int_32 i)); 2618 #endif 2619 2620 /* Place a 16-bit number into a buffer in PNG byte order. 2621 * The parameter is declared unsigned int, not png_uint_16, 2622 * just to avoid potential problems on pre-ANSI C compilers. 2623 */ 2624 #ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED 2625 PNG_EXPORT(207, void, png_save_uint_16, (png_bytep buf, unsigned int i)); 2626 /* No png_save_int_16 -- may be added if there's a real need for it. */ 2627 #endif 2628 2629 #ifdef PNG_USE_READ_MACROS 2630 /* Inline macros to do direct reads of bytes from the input buffer. 2631 * The png_get_int_32() routine assumes we are using two's complement 2632 * format for negative values, which is almost certainly true. 2633 */ 2634 # define PNG_get_uint_32(buf) \ 2635 (((png_uint_32)(*(buf)) << 24) + \ 2636 ((png_uint_32)(*((buf) + 1)) << 16) + \ 2637 ((png_uint_32)(*((buf) + 2)) << 8) + \ 2638 ((png_uint_32)(*((buf) + 3)))) 2639 2640 /* From libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the 2641 * function) incorrectly returned a value of type png_uint_32. 2642 */ 2643 # define PNG_get_uint_16(buf) \ 2644 ((png_uint_16) \ 2645 (((unsigned int)(*(buf)) << 8) + \ 2646 ((unsigned int)(*((buf) + 1))))) 2647 2648 # define PNG_get_int_32(buf) \ 2649 ((png_int_32)((*(buf) & 0x80) \ 2650 ? -((png_int_32)(((png_get_uint_32(buf)^0xffffffffU)+1U)&0x7fffffffU)) \ 2651 : (png_int_32)png_get_uint_32(buf))) 2652 2653 /* If PNG_PREFIX is defined the same thing as below happens in pnglibconf.h, 2654 * but defining a macro name prefixed with PNG_PREFIX. 2655 */ 2656 # ifndef PNG_PREFIX 2657 # define png_get_uint_32(buf) PNG_get_uint_32(buf) 2658 # define png_get_uint_16(buf) PNG_get_uint_16(buf) 2659 # define png_get_int_32(buf) PNG_get_int_32(buf) 2660 # endif 2661 #else 2662 # ifdef PNG_PREFIX 2663 /* No macros; revert to the (redefined) function */ 2664 # define PNG_get_uint_32 (png_get_uint_32) 2665 # define PNG_get_uint_16 (png_get_uint_16) 2666 # define PNG_get_int_32 (png_get_int_32) 2667 # endif 2668 #endif 2669 2670 #ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED 2671 PNG_EXPORT(242, void, png_set_check_for_invalid_index, 2672 (png_structrp png_ptr, int allowed)); 2673 # ifdef PNG_GET_PALETTE_MAX_SUPPORTED 2674 PNG_EXPORT(243, int, png_get_palette_max, (png_const_structp png_ptr, 2675 png_const_infop info_ptr)); 2676 # endif 2677 #endif /* CHECK_FOR_INVALID_INDEX */ 2678 2679 /******************************************************************************* 2680 * Section 5: SIMPLIFIED API 2681 ******************************************************************************* 2682 * 2683 * Please read the documentation in libpng-manual.txt (TODO: write said 2684 * documentation) if you don't understand what follows. 2685 * 2686 * The simplified API hides the details of both libpng and the PNG file format 2687 * itself. It allows PNG files to be read into a very limited number of 2688 * in-memory bitmap formats or to be written from the same formats. If these 2689 * formats do not accomodate your needs then you can, and should, use the more 2690 * sophisticated APIs above - these support a wide variety of in-memory formats 2691 * and a wide variety of sophisticated transformations to those formats as well 2692 * as a wide variety of APIs to manipulate ancillary information. 2693 * 2694 * To read a PNG file using the simplified API: 2695 * 2696 * 1) Declare a 'png_image' structure (see below) on the stack, set the 2697 * version field to PNG_IMAGE_VERSION and the 'opaque' pointer to NULL 2698 * (this is REQUIRED, your program may crash if you don't do it.) 2699 * 2) Call the appropriate png_image_begin_read... function. 2700 * 3) Set the png_image 'format' member to the required sample format. 2701 * 4) Allocate a buffer for the image and, if required, the color-map. 2702 * 5) Call png_image_finish_read to read the image and, if required, the 2703 * color-map into your buffers. 2704 * 2705 * There are no restrictions on the format of the PNG input itself; all valid 2706 * color types, bit depths, and interlace methods are acceptable, and the 2707 * input image is transformed as necessary to the requested in-memory format 2708 * during the png_image_finish_read() step. The only caveat is that if you 2709 * request a color-mapped image from a PNG that is full-color or makes 2710 * complex use of an alpha channel the transformation is extremely lossy and the 2711 * result may look terrible. 2712 * 2713 * To write a PNG file using the simplified API: 2714 * 2715 * 1) Declare a 'png_image' structure on the stack and memset() it to all zero. 2716 * 2) Initialize the members of the structure that describe the image, setting 2717 * the 'format' member to the format of the image samples. 2718 * 3) Call the appropriate png_image_write... function with a pointer to the 2719 * image and, if necessary, the color-map to write the PNG data. 2720 * 2721 * png_image is a structure that describes the in-memory format of an image 2722 * when it is being read or defines the in-memory format of an image that you 2723 * need to write: 2724 */ 2725 #if defined(PNG_SIMPLIFIED_READ_SUPPORTED) || \ 2726 defined(PNG_SIMPLIFIED_WRITE_SUPPORTED) 2727 2728 #define PNG_IMAGE_VERSION 1 2729 2730 typedef struct png_control *png_controlp; 2731 typedef struct 2732 { 2733 png_controlp opaque; /* Initialize to NULL, free with png_image_free */ 2734 png_uint_32 version; /* Set to PNG_IMAGE_VERSION */ 2735 png_uint_32 width; /* Image width in pixels (columns) */ 2736 png_uint_32 height; /* Image height in pixels (rows) */ 2737 png_uint_32 format; /* Image format as defined below */ 2738 png_uint_32 flags; /* A bit mask containing informational flags */ 2739 png_uint_32 colormap_entries; 2740 /* Number of entries in the color-map */ 2741 2742 /* In the event of an error or warning the following field will be set to a 2743 * non-zero value and the 'message' field will contain a '\0' terminated 2744 * string with the libpng error or warning message. If both warnings and 2745 * an error were encountered, only the error is recorded. If there 2746 * are multiple warnings, only the first one is recorded. 2747 * 2748 * The upper 30 bits of this value are reserved, the low two bits contain 2749 * a value as follows: 2750 */ 2751 # define PNG_IMAGE_WARNING 1 2752 # define PNG_IMAGE_ERROR 2 2753 /* 2754 * The result is a two-bit code such that a value more than 1 indicates 2755 * a failure in the API just called: 2756 * 2757 * 0 - no warning or error 2758 * 1 - warning 2759 * 2 - error 2760 * 3 - error preceded by warning 2761 */ 2762 # define PNG_IMAGE_FAILED(png_cntrl) ((((png_cntrl).warning_or_error)&0x03)>1) 2763 2764 png_uint_32 warning_or_error; 2765 2766 char message[64]; 2767 } png_image, *png_imagep; 2768 2769 /* The samples of the image have one to four channels whose components have 2770 * original values in the range 0 to 1.0: 2771 * 2772 * 1: A single gray or luminance channel (G). 2773 * 2: A gray/luminance channel and an alpha channel (GA). 2774 * 3: Three red, green, blue color channels (RGB). 2775 * 4: Three color channels and an alpha channel (RGBA). 2776 * 2777 * The components are encoded in one of two ways: 2778 * 2779 * a) As a small integer, value 0..255, contained in a single byte. For the 2780 * alpha channel the original value is simply value/255. For the color or 2781 * luminance channels the value is encoded according to the sRGB specification 2782 * and matches the 8-bit format expected by typical display devices. 2783 * 2784 * The color/gray channels are not scaled (pre-multiplied) by the alpha 2785 * channel and are suitable for passing to color management software. 2786 * 2787 * b) As a value in the range 0..65535, contained in a 2-byte integer. All 2788 * channels can be converted to the original value by dividing by 65535; all 2789 * channels are linear. Color channels use the RGB encoding (RGB end-points) of 2790 * the sRGB specification. This encoding is identified by the 2791 * PNG_FORMAT_FLAG_LINEAR flag below. 2792 * 2793 * When the simplified API needs to convert between sRGB and linear colorspaces, 2794 * the actual sRGB transfer curve defined in the sRGB specification (see the 2795 * article at https://en.wikipedia.org/wiki/SRGB) is used, not the gamma=1/2.2 2796 * approximation used elsewhere in libpng. 2797 * 2798 * When an alpha channel is present it is expected to denote pixel coverage 2799 * of the color or luminance channels and is returned as an associated alpha 2800 * channel: the color/gray channels are scaled (pre-multiplied) by the alpha 2801 * value. 2802 * 2803 * The samples are either contained directly in the image data, between 1 and 8 2804 * bytes per pixel according to the encoding, or are held in a color-map indexed 2805 * by bytes in the image data. In the case of a color-map the color-map entries 2806 * are individual samples, encoded as above, and the image data has one byte per 2807 * pixel to select the relevant sample from the color-map. 2808 */ 2809 2810 /* PNG_FORMAT_* 2811 * 2812 * #defines to be used in png_image::format. Each #define identifies a 2813 * particular layout of sample data and, if present, alpha values. There are 2814 * separate defines for each of the two component encodings. 2815 * 2816 * A format is built up using single bit flag values. All combinations are 2817 * valid. Formats can be built up from the flag values or you can use one of 2818 * the predefined values below. When testing formats always use the FORMAT_FLAG 2819 * macros to test for individual features - future versions of the library may 2820 * add new flags. 2821 * 2822 * When reading or writing color-mapped images the format should be set to the 2823 * format of the entries in the color-map then png_image_{read,write}_colormap 2824 * called to read or write the color-map and set the format correctly for the 2825 * image data. Do not set the PNG_FORMAT_FLAG_COLORMAP bit directly! 2826 * 2827 * NOTE: libpng can be built with particular features disabled. If you see 2828 * compiler errors because the definition of one of the following flags has been 2829 * compiled out it is because libpng does not have the required support. It is 2830 * possible, however, for the libpng configuration to enable the format on just 2831 * read or just write; in that case you may see an error at run time. You can 2832 * guard against this by checking for the definition of the appropriate 2833 * "_SUPPORTED" macro, one of: 2834 * 2835 * PNG_SIMPLIFIED_{READ,WRITE}_{BGR,AFIRST}_SUPPORTED 2836 */ 2837 #define PNG_FORMAT_FLAG_ALPHA 0x01U /* format with an alpha channel */ 2838 #define PNG_FORMAT_FLAG_COLOR 0x02U /* color format: otherwise grayscale */ 2839 #define PNG_FORMAT_FLAG_LINEAR 0x04U /* 2-byte channels else 1-byte */ 2840 #define PNG_FORMAT_FLAG_COLORMAP 0x08U /* image data is color-mapped */ 2841 2842 #ifdef PNG_FORMAT_BGR_SUPPORTED 2843 # define PNG_FORMAT_FLAG_BGR 0x10U /* BGR colors, else order is RGB */ 2844 #endif 2845 2846 #ifdef PNG_FORMAT_AFIRST_SUPPORTED 2847 # define PNG_FORMAT_FLAG_AFIRST 0x20U /* alpha channel comes first */ 2848 #endif 2849 2850 #define PNG_FORMAT_FLAG_ASSOCIATED_ALPHA 0x40U /* alpha channel is associated */ 2851 2852 /* Commonly used formats have predefined macros. 2853 * 2854 * First the single byte (sRGB) formats: 2855 */ 2856 #define PNG_FORMAT_GRAY 0 2857 #define PNG_FORMAT_GA PNG_FORMAT_FLAG_ALPHA 2858 #define PNG_FORMAT_AG (PNG_FORMAT_GA|PNG_FORMAT_FLAG_AFIRST) 2859 #define PNG_FORMAT_RGB PNG_FORMAT_FLAG_COLOR 2860 #define PNG_FORMAT_BGR (PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_BGR) 2861 #define PNG_FORMAT_RGBA (PNG_FORMAT_RGB|PNG_FORMAT_FLAG_ALPHA) 2862 #define PNG_FORMAT_ARGB (PNG_FORMAT_RGBA|PNG_FORMAT_FLAG_AFIRST) 2863 #define PNG_FORMAT_BGRA (PNG_FORMAT_BGR|PNG_FORMAT_FLAG_ALPHA) 2864 #define PNG_FORMAT_ABGR (PNG_FORMAT_BGRA|PNG_FORMAT_FLAG_AFIRST) 2865 2866 /* Then the linear 2-byte formats. When naming these "Y" is used to 2867 * indicate a luminance (gray) channel. 2868 */ 2869 #define PNG_FORMAT_LINEAR_Y PNG_FORMAT_FLAG_LINEAR 2870 #define PNG_FORMAT_LINEAR_Y_ALPHA (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_ALPHA) 2871 #define PNG_FORMAT_LINEAR_RGB (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR) 2872 #define PNG_FORMAT_LINEAR_RGB_ALPHA \ 2873 (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_ALPHA) 2874 2875 /* With color-mapped formats the image data is one byte for each pixel, the byte 2876 * is an index into the color-map which is formatted as above. To obtain a 2877 * color-mapped format it is sufficient just to add the PNG_FOMAT_FLAG_COLORMAP 2878 * to one of the above definitions, or you can use one of the definitions below. 2879 */ 2880 #define PNG_FORMAT_RGB_COLORMAP (PNG_FORMAT_RGB|PNG_FORMAT_FLAG_COLORMAP) 2881 #define PNG_FORMAT_BGR_COLORMAP (PNG_FORMAT_BGR|PNG_FORMAT_FLAG_COLORMAP) 2882 #define PNG_FORMAT_RGBA_COLORMAP (PNG_FORMAT_RGBA|PNG_FORMAT_FLAG_COLORMAP) 2883 #define PNG_FORMAT_ARGB_COLORMAP (PNG_FORMAT_ARGB|PNG_FORMAT_FLAG_COLORMAP) 2884 #define PNG_FORMAT_BGRA_COLORMAP (PNG_FORMAT_BGRA|PNG_FORMAT_FLAG_COLORMAP) 2885 #define PNG_FORMAT_ABGR_COLORMAP (PNG_FORMAT_ABGR|PNG_FORMAT_FLAG_COLORMAP) 2886 2887 /* PNG_IMAGE macros 2888 * 2889 * These are convenience macros to derive information from a png_image 2890 * structure. The PNG_IMAGE_SAMPLE_ macros return values appropriate to the 2891 * actual image sample values - either the entries in the color-map or the 2892 * pixels in the image. The PNG_IMAGE_PIXEL_ macros return corresponding values 2893 * for the pixels and will always return 1 for color-mapped formats. The 2894 * remaining macros return information about the rows in the image and the 2895 * complete image. 2896 * 2897 * NOTE: All the macros that take a png_image::format parameter are compile time 2898 * constants if the format parameter is, itself, a constant. Therefore these 2899 * macros can be used in array declarations and case labels where required. 2900 * Similarly the macros are also pre-processor constants (sizeof is not used) so 2901 * they can be used in #if tests. 2902 * 2903 * First the information about the samples. 2904 */ 2905 #define PNG_IMAGE_SAMPLE_CHANNELS(fmt)\ 2906 (((fmt)&(PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_ALPHA))+1) 2907 /* Return the total number of channels in a given format: 1..4 */ 2908 2909 #define PNG_IMAGE_SAMPLE_COMPONENT_SIZE(fmt)\ 2910 ((((fmt) & PNG_FORMAT_FLAG_LINEAR) >> 2)+1) 2911 /* Return the size in bytes of a single component of a pixel or color-map 2912 * entry (as appropriate) in the image: 1 or 2. 2913 */ 2914 2915 #define PNG_IMAGE_SAMPLE_SIZE(fmt)\ 2916 (PNG_IMAGE_SAMPLE_CHANNELS(fmt) * PNG_IMAGE_SAMPLE_COMPONENT_SIZE(fmt)) 2917 /* This is the size of the sample data for one sample. If the image is 2918 * color-mapped it is the size of one color-map entry (and image pixels are 2919 * one byte in size), otherwise it is the size of one image pixel. 2920 */ 2921 2922 #define PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(fmt)\ 2923 (PNG_IMAGE_SAMPLE_CHANNELS(fmt) * 256) 2924 /* The maximum size of the color-map required by the format expressed in a 2925 * count of components. This can be used to compile-time allocate a 2926 * color-map: 2927 * 2928 * png_uint_16 colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(linear_fmt)]; 2929 * 2930 * png_byte colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(sRGB_fmt)]; 2931 * 2932 * Alternatively use the PNG_IMAGE_COLORMAP_SIZE macro below to use the 2933 * information from one of the png_image_begin_read_ APIs and dynamically 2934 * allocate the required memory. 2935 */ 2936 2937 /* Corresponding information about the pixels */ 2938 #define PNG_IMAGE_PIXEL_(test,fmt)\ 2939 (((fmt)&PNG_FORMAT_FLAG_COLORMAP)?1:test(fmt)) 2940 2941 #define PNG_IMAGE_PIXEL_CHANNELS(fmt)\ 2942 PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_CHANNELS,fmt) 2943 /* The number of separate channels (components) in a pixel; 1 for a 2944 * color-mapped image. 2945 */ 2946 2947 #define PNG_IMAGE_PIXEL_COMPONENT_SIZE(fmt)\ 2948 PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_COMPONENT_SIZE,fmt) 2949 /* The size, in bytes, of each component in a pixel; 1 for a color-mapped 2950 * image. 2951 */ 2952 2953 #define PNG_IMAGE_PIXEL_SIZE(fmt) PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_SIZE,fmt) 2954 /* The size, in bytes, of a complete pixel; 1 for a color-mapped image. */ 2955 2956 /* Information about the whole row, or whole image */ 2957 #define PNG_IMAGE_ROW_STRIDE(image)\ 2958 (PNG_IMAGE_PIXEL_CHANNELS((image).format) * (image).width) 2959 /* Return the total number of components in a single row of the image; this 2960 * is the minimum 'row stride', the minimum count of components between each 2961 * row. For a color-mapped image this is the minimum number of bytes in a 2962 * row. 2963 * 2964 * WARNING: this macro overflows for some images with more than one component 2965 * and very large image widths. libpng will refuse to process an image where 2966 * this macro would overflow. 2967 */ 2968 2969 #define PNG_IMAGE_BUFFER_SIZE(image, row_stride)\ 2970 (PNG_IMAGE_PIXEL_COMPONENT_SIZE((image).format)*(image).height*(row_stride)) 2971 /* Return the size, in bytes, of an image buffer given a png_image and a row 2972 * stride - the number of components to leave space for in each row. 2973 * 2974 * WARNING: this macro overflows a 32-bit integer for some large PNG images, 2975 * libpng will refuse to process an image where such an overflow would occur. 2976 */ 2977 2978 #define PNG_IMAGE_SIZE(image)\ 2979 PNG_IMAGE_BUFFER_SIZE(image, PNG_IMAGE_ROW_STRIDE(image)) 2980 /* Return the size, in bytes, of the image in memory given just a png_image; 2981 * the row stride is the minimum stride required for the image. 2982 */ 2983 2984 #define PNG_IMAGE_COLORMAP_SIZE(image)\ 2985 (PNG_IMAGE_SAMPLE_SIZE((image).format) * (image).colormap_entries) 2986 /* Return the size, in bytes, of the color-map of this image. If the image 2987 * format is not a color-map format this will return a size sufficient for 2988 * 256 entries in the given format; check PNG_FORMAT_FLAG_COLORMAP if 2989 * you don't want to allocate a color-map in this case. 2990 */ 2991 2992 /* PNG_IMAGE_FLAG_* 2993 * 2994 * Flags containing additional information about the image are held in the 2995 * 'flags' field of png_image. 2996 */ 2997 #define PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB 0x01 2998 /* This indicates the the RGB values of the in-memory bitmap do not 2999 * correspond to the red, green and blue end-points defined by sRGB. 3000 */ 3001 3002 #define PNG_IMAGE_FLAG_FAST 0x02 3003 /* On write emphasise speed over compression; the resultant PNG file will be 3004 * larger but will be produced significantly faster, particular for large 3005 * images. Do not use this option for images which will be distributed, only 3006 * used it when producing intermediate files that will be read back in 3007 * repeatedly. For a typical 24-bit image the option will double the read 3008 * speed at the cost of increasing the image size by 25%, however for many 3009 * more compressible images the PNG file can be 10 times larger with only a 3010 * slight speed gain. 3011 */ 3012 3013 #define PNG_IMAGE_FLAG_16BIT_sRGB 0x04 3014 /* On read if the image is a 16-bit per component image and there is no gAMA 3015 * or sRGB chunk assume that the components are sRGB encoded. Notice that 3016 * images output by the simplified API always have gamma information; setting 3017 * this flag only affects the interpretation of 16-bit images from an 3018 * external source. It is recommended that the application expose this flag 3019 * to the user; the user can normally easily recognize the difference between 3020 * linear and sRGB encoding. This flag has no effect on write - the data 3021 * passed to the write APIs must have the correct encoding (as defined 3022 * above.) 3023 * 3024 * If the flag is not set (the default) input 16-bit per component data is 3025 * assumed to be linear. 3026 * 3027 * NOTE: the flag can only be set after the png_image_begin_read_ call, 3028 * because that call initializes the 'flags' field. 3029 */ 3030 3031 #ifdef PNG_SIMPLIFIED_READ_SUPPORTED 3032 /* READ APIs 3033 * --------- 3034 * 3035 * The png_image passed to the read APIs must have been initialized by setting 3036 * the png_controlp field 'opaque' to NULL (or, safer, memset the whole thing.) 3037 */ 3038 #ifdef PNG_STDIO_SUPPORTED 3039 PNG_EXPORT(234, int, png_image_begin_read_from_file, (png_imagep image, 3040 const char *file_name)); 3041 /* The named file is opened for read and the image header is filled in 3042 * from the PNG header in the file. 3043 */ 3044 3045 PNG_EXPORT(235, int, png_image_begin_read_from_stdio, (png_imagep image, 3046 FILE* file)); 3047 /* The PNG header is read from the stdio FILE object. */ 3048 #endif /* STDIO */ 3049 3050 PNG_EXPORT(236, int, png_image_begin_read_from_memory, (png_imagep image, 3051 png_const_voidp memory, png_size_t size)); 3052 /* The PNG header is read from the given memory buffer. */ 3053 3054 PNG_EXPORT(237, int, png_image_finish_read, (png_imagep image, 3055 png_const_colorp background, void *buffer, png_int_32 row_stride, 3056 void *colormap)); 3057 /* Finish reading the image into the supplied buffer and clean up the 3058 * png_image structure. 3059 * 3060 * row_stride is the step, in byte or 2-byte units as appropriate, 3061 * between adjacent rows. A positive stride indicates that the top-most row 3062 * is first in the buffer - the normal top-down arrangement. A negative 3063 * stride indicates that the bottom-most row is first in the buffer. 3064 * 3065 * background need only be supplied if an alpha channel must be removed from 3066 * a png_byte format and the removal is to be done by compositing on a solid 3067 * color; otherwise it may be NULL and any composition will be done directly 3068 * onto the buffer. The value is an sRGB color to use for the background, 3069 * for grayscale output the green channel is used. 3070 * 3071 * background must be supplied when an alpha channel must be removed from a 3072 * single byte color-mapped output format, in other words if: 3073 * 3074 * 1) The original format from png_image_begin_read_from_* had 3075 * PNG_FORMAT_FLAG_ALPHA set. 3076 * 2) The format set by the application does not. 3077 * 3) The format set by the application has PNG_FORMAT_FLAG_COLORMAP set and 3078 * PNG_FORMAT_FLAG_LINEAR *not* set. 3079 * 3080 * For linear output removing the alpha channel is always done by compositing 3081 * on black and background is ignored. 3082 * 3083 * colormap must be supplied when PNG_FORMAT_FLAG_COLORMAP is set. It must 3084 * be at least the size (in bytes) returned by PNG_IMAGE_COLORMAP_SIZE. 3085 * image->colormap_entries will be updated to the actual number of entries 3086 * written to the colormap; this may be less than the original value. 3087 */ 3088 3089 PNG_EXPORT(238, void, png_image_free, (png_imagep image)); 3090 /* Free any data allocated by libpng in image->opaque, setting the pointer to 3091 * NULL. May be called at any time after the structure is initialized. 3092 */ 3093 #endif /* SIMPLIFIED_READ */ 3094 3095 #ifdef PNG_SIMPLIFIED_WRITE_SUPPORTED 3096 /* WRITE APIS 3097 * ---------- 3098 * For write you must initialize a png_image structure to describe the image to 3099 * be written. To do this use memset to set the whole structure to 0 then 3100 * initialize fields describing your image. 3101 * 3102 * version: must be set to PNG_IMAGE_VERSION 3103 * opaque: must be initialized to NULL 3104 * width: image width in pixels 3105 * height: image height in rows 3106 * format: the format of the data (image and color-map) you wish to write 3107 * flags: set to 0 unless one of the defined flags applies; set 3108 * PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB for color format images where the RGB 3109 * values do not correspond to the colors in sRGB. 3110 * colormap_entries: set to the number of entries in the color-map (0 to 256) 3111 */ 3112 #ifdef PNG_SIMPLIFIED_WRITE_STDIO_SUPPORTED 3113 PNG_EXPORT(239, int, png_image_write_to_file, (png_imagep image, 3114 const char *file, int convert_to_8bit, const void *buffer, 3115 png_int_32 row_stride, const void *colormap)); 3116 /* Write the image to the named file. */ 3117 3118 PNG_EXPORT(240, int, png_image_write_to_stdio, (png_imagep image, FILE *file, 3119 int convert_to_8_bit, const void *buffer, png_int_32 row_stride, 3120 const void *colormap)); 3121 /* Write the image to the given (FILE*). */ 3122 #endif /* SIMPLIFIED_WRITE_STDIO */ 3123 3124 /* With all write APIs if image is in one of the linear formats with 16-bit 3125 * data then setting convert_to_8_bit will cause the output to be an 8-bit PNG 3126 * gamma encoded according to the sRGB specification, otherwise a 16-bit linear 3127 * encoded PNG file is written. 3128 * 3129 * With color-mapped data formats the colormap parameter point to a color-map 3130 * with at least image->colormap_entries encoded in the specified format. If 3131 * the format is linear the written PNG color-map will be converted to sRGB 3132 * regardless of the convert_to_8_bit flag. 3133 * 3134 * With all APIs row_stride is handled as in the read APIs - it is the spacing 3135 * from one row to the next in component sized units (1 or 2 bytes) and if 3136 * negative indicates a bottom-up row layout in the buffer. If row_stride is 3137 * zero, libpng will calculate it for you from the image width and number of 3138 * channels. 3139 * 3140 * Note that the write API does not support interlacing, sub-8-bit pixels or 3141 * most ancillary chunks. If you need to write text chunks (e.g. for copyright 3142 * notices) you need to use one of the other APIs. 3143 */ 3144 3145 PNG_EXPORT(245, int, png_image_write_to_memory, (png_imagep image, void *memory, 3146 png_alloc_size_t * PNG_RESTRICT memory_bytes, int convert_to_8_bit, 3147 const void *buffer, png_int_32 row_stride, const void *colormap)); 3148 /* Write the image to the given memory buffer. The function both writes the 3149 * whole PNG data stream to *memory and updates *memory_bytes with the count 3150 * of bytes written. 3151 * 3152 * 'memory' may be NULL. In this case *memory_bytes is not read however on 3153 * success the number of bytes which would have been written will still be 3154 * stored in *memory_bytes. On failure *memory_bytes will contain 0. 3155 * 3156 * If 'memory' is not NULL it must point to memory[*memory_bytes] of 3157 * writeable memory. 3158 * 3159 * If the function returns success memory[*memory_bytes] (if 'memory' is not 3160 * NULL) contains the written PNG data. *memory_bytes will always be less 3161 * than or equal to the original value. 3162 * 3163 * If the function returns false and *memory_bytes was not changed an error 3164 * occured during write. If *memory_bytes was changed, or is not 0 if 3165 * 'memory' was NULL, the write would have succeeded but for the memory 3166 * buffer being too small. *memory_bytes contains the required number of 3167 * bytes and will be bigger that the original value. 3168 */ 3169 3170 #define png_image_write_get_memory_size(image, size, convert_to_8_bit, buffer,\ 3171 row_stride, colormap)\ 3172 png_image_write_to_memory(&(image), 0, &(size), convert_to_8_bit, buffer,\ 3173 row_stride, colormap) 3174 /* Return the amount of memory in 'size' required to compress this image. 3175 * The png_image structure 'image' must be filled in as in the above 3176 * function and must not be changed before the actual write call, the buffer 3177 * and all other parameters must also be identical to that in the final 3178 * write call. The 'size' variable need not be initialized. 3179 * 3180 * NOTE: the macro returns true/false, if false is returned 'size' will be 3181 * set to zero and the write failed and probably will fail if tried again. 3182 */ 3183 3184 /* You can pre-allocate the buffer by making sure it is of sufficient size 3185 * regardless of the amount of compression achieved. The buffer size will 3186 * always be bigger than the original image and it will never be filled. The 3187 * following macros are provided to assist in allocating the buffer. 3188 */ 3189 #define PNG_IMAGE_DATA_SIZE(image) (PNG_IMAGE_SIZE(image)+(image).height) 3190 /* The number of uncompressed bytes in the PNG byte encoding of the image; 3191 * uncompressing the PNG IDAT data will give this number of bytes. 3192 * 3193 * NOTE: while PNG_IMAGE_SIZE cannot overflow for an image in memory this 3194 * macro can because of the extra bytes used in the PNG byte encoding. You 3195 * need to avoid this macro if your image size approaches 2^30 in width or 3196 * height. The same goes for the remainder of these macros; they all produce 3197 * bigger numbers than the actual in-memory image size. 3198 */ 3199 #ifndef PNG_ZLIB_MAX_SIZE 3200 # define PNG_ZLIB_MAX_SIZE(b) ((b)+(((b)+7U)>>3)+(((b)+63U)>>6)+11U) 3201 /* An upper bound on the number of compressed bytes given 'b' uncompressed 3202 * bytes. This is based on deflateBounds() in zlib; different 3203 * implementations of zlib compression may conceivably produce more data so 3204 * if your zlib implementation is not zlib itself redefine this macro 3205 * appropriately. 3206 */ 3207 #endif 3208 3209 #define PNG_IMAGE_COMPRESSED_SIZE_MAX(image)\ 3210 PNG_ZLIB_MAX_SIZE((png_alloc_size_t)PNG_IMAGE_DATA_SIZE(image)) 3211 /* An upper bound on the size of the data in the PNG IDAT chunks. */ 3212 3213 #define PNG_IMAGE_PNG_SIZE_MAX_(image, image_size)\ 3214 ((8U/*sig*/+25U/*IHDR*/+16U/*gAMA*/+44U/*cHRM*/+12U/*IEND*/+\ 3215 (((image).format&PNG_FORMAT_FLAG_COLORMAP)?/*colormap: PLTE, tRNS*/\ 3216 12U+3U*(image).colormap_entries/*PLTE data*/+\ 3217 (((image).format&PNG_FORMAT_FLAG_ALPHA)?\ 3218 12U/*tRNS*/+(image).colormap_entries:0U):0U)+\ 3219 12U)+(12U*((image_size)/PNG_ZBUF_SIZE))/*IDAT*/+(image_size)) 3220 /* A helper for the following macro; if your compiler cannot handle the 3221 * following macro use this one with the result of 3222 * PNG_IMAGE_COMPRESSED_SIZE_MAX(image) as the second argument (most 3223 * compilers should handle this just fine.) 3224 */ 3225 3226 #define PNG_IMAGE_PNG_SIZE_MAX(image)\ 3227 PNG_IMAGE_PNG_SIZE_MAX_(image, PNG_IMAGE_COMPRESSED_SIZE_MAX(image)) 3228 /* An upper bound on the total length of the PNG data stream for 'image'. 3229 * The result is of type png_alloc_size_t, on 32-bit systems this may 3230 * overflow even though PNG_IMAGE_DATA_SIZE does not overflow; the write will 3231 * run out of buffer space but return a corrected size which should work. 3232 */ 3233 #endif /* SIMPLIFIED_WRITE */ 3234 /******************************************************************************* 3235 * END OF SIMPLIFIED API 3236 ******************************************************************************/ 3237 #endif /* SIMPLIFIED_{READ|WRITE} */ 3238 3239 /******************************************************************************* 3240 * Section 6: IMPLEMENTATION OPTIONS 3241 ******************************************************************************* 3242 * 3243 * Support for arbitrary implementation-specific optimizations. The API allows 3244 * particular options to be turned on or off. 'Option' is the number of the 3245 * option and 'onoff' is 0 (off) or non-0 (on). The value returned is given 3246 * by the PNG_OPTION_ defines below. 3247 * 3248 * HARDWARE: normally hardware capabilites, such as the Intel SSE instructions, 3249 * are detected at run time, however sometimes it may be impossible 3250 * to do this in user mode, in which case it is necessary to discover 3251 * the capabilities in an OS specific way. Such capabilities are 3252 * listed here when libpng has support for them and must be turned 3253 * ON by the application if present. 3254 * 3255 * SOFTWARE: sometimes software optimizations actually result in performance 3256 * decrease on some architectures or systems, or with some sets of 3257 * PNG images. 'Software' options allow such optimizations to be 3258 * selected at run time. 3259 */ 3260 #ifdef PNG_SET_OPTION_SUPPORTED 3261 #ifdef PNG_ARM_NEON_API_SUPPORTED 3262 # define PNG_ARM_NEON 0 /* HARDWARE: ARM Neon SIMD instructions supported */ 3263 #endif 3264 #define PNG_MAXIMUM_INFLATE_WINDOW 2 /* SOFTWARE: force maximum window */ 3265 #define PNG_SKIP_sRGB_CHECK_PROFILE 4 /* SOFTWARE: Check ICC profile for sRGB */ 3266 #ifdef PNG_MIPS_MSA_API_SUPPORTED 3267 # define PNG_MIPS_MSA 6 /* HARDWARE: MIPS Msa SIMD instructions supported */ 3268 #endif 3269 #define PNG_IGNORE_ADLER32 8 3270 #ifdef PNG_POWERPC_VSX_API_SUPPORTED 3271 # define PNG_POWERPC_VSX 10 /* HARDWARE: PowerPC VSX SIMD instructions supported */ 3272 #endif 3273 #define PNG_OPTION_NEXT 12 /* Next option - numbers must be even */ 3274 3275 /* Return values: NOTE: there are four values and 'off' is *not* zero */ 3276 #define PNG_OPTION_UNSET 0 /* Unset - defaults to off */ 3277 #define PNG_OPTION_INVALID 1 /* Option number out of range */ 3278 #define PNG_OPTION_OFF 2 3279 #define PNG_OPTION_ON 3 3280 3281 PNG_EXPORT(244, int, png_set_option, (png_structrp png_ptr, int option, 3282 int onoff)); 3283 #endif /* SET_OPTION */ 3284 3285 /******************************************************************************* 3286 * END OF HARDWARE AND SOFTWARE OPTIONS 3287 ******************************************************************************/ 3288 3289 /* Maintainer: Put new public prototypes here ^, in libpng.3, in project 3290 * defs, and in scripts/symbols.def. 3291 */ 3292 3293 /* The last ordinal number (this is the *last* one already used; the next 3294 * one to use is one more than this.) 3295 */ 3296 #ifdef PNG_EXPORT_LAST_ORDINAL 3297 PNG_EXPORT_LAST_ORDINAL(249); 3298 #endif 3299 3300 #ifdef __cplusplus 3301 } 3302 #endif 3303 3304 #endif /* PNG_VERSION_INFO_ONLY */ 3305 /* Do not put anything past this line */ 3306 #endif /* PNG_H */