1 2 /* png.h - header file for PNG reference library 3 * 4 * libpng version 1.6.25, September 1, 2016 5 * 6 * Copyright (c) 1998-2002,2004,2006-2016 Glenn Randers-Pehrson 7 * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) 8 * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) 9 * 10 * This code is released under the libpng license (See LICENSE, below) 11 * 12 * Authors and maintainers: 13 * libpng versions 0.71, May 1995, through 0.88, January 1996: Guy Schalnat 14 * libpng versions 0.89, June 1996, through 0.96, May 1997: Andreas Dilger 15 * libpng versions 0.97, January 1998, through 1.6.25, September 1, 2016: 16 * Glenn Randers-Pehrson. 17 * See also "Contributing Authors", below. 18 */ 19 20 /* 21 * COPYRIGHT NOTICE, DISCLAIMER, and LICENSE: 22 * 23 * If you modify libpng you may insert additional notices immediately following 24 * this sentence. 25 * 26 * This code is released under the libpng license. 27 * 28 * Some files in the "contrib" directory and some configure-generated 29 * files that are distributed with libpng have other copyright owners and 30 * are released under other open source licenses. 31 * 32 * libpng versions 1.0.7, July 1, 2000 through 1.6.25, September 1, 2016 are 33 * Copyright (c) 2000-2002, 2004, 2006-2016 Glenn Randers-Pehrson, are 34 * derived from libpng-1.0.6, and are distributed according to the same 35 * disclaimer and license as libpng-1.0.6 with the following individuals 36 * added to the list of Contributing Authors: 37 * 38 * Simon-Pierre Cadieux 39 * Eric S. Raymond 40 * Mans Rullgard 41 * Cosmin Truta 42 * Gilles Vollant 43 * James Yu 44 * Mandar Sahastrabuddhe 45 * 46 * and with the following additions to the disclaimer: 47 * 48 * There is no warranty against interference with your enjoyment of the 49 * library or against infringement. There is no warranty that our 50 * efforts or the library will fulfill any of your particular purposes 51 * or needs. This library is provided with all faults, and the entire 52 * risk of satisfactory quality, performance, accuracy, and effort is with 53 * the user. 54 * 55 * Some files in the "contrib" directory have other copyright owners and 56 * are released under other open source licenses. 57 * 58 * 59 * libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are 60 * Copyright (c) 1998-2000 Glenn Randers-Pehrson, are derived from 61 * libpng-0.96, and are distributed according to the same disclaimer and 62 * license as libpng-0.96, with the following individuals added to the list 63 * of Contributing Authors: 64 * 65 * Tom Lane 66 * Glenn Randers-Pehrson 67 * Willem van Schaik 68 * 69 * Some files in the "scripts" directory have different copyright owners 70 * but are also released under this license. 71 * 72 * libpng versions 0.89, June 1996, through 0.96, May 1997, are 73 * Copyright (c) 1996-1997 Andreas Dilger, are derived from libpng-0.88, 74 * and are distributed according to the same disclaimer and license as 75 * libpng-0.88, with the following individuals added to the list of 76 * Contributing Authors: 77 * 78 * John Bowler 79 * Kevin Bracey 80 * Sam Bushell 81 * Magnus Holmgren 82 * Greg Roelofs 83 * Tom Tanner 84 * 85 * Some files in the "scripts" directory have other copyright owners 86 * but are released under this license. 87 * 88 * libpng versions 0.5, May 1995, through 0.88, January 1996, are 89 * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc. 90 * 91 * For the purposes of this copyright and license, "Contributing Authors" 92 * is defined as the following set of individuals: 93 * 94 * Andreas Dilger 95 * Dave Martindale 96 * Guy Eric Schalnat 97 * Paul Schmidt 98 * Tim Wegner 99 * 100 * The PNG Reference Library is supplied "AS IS". The Contributing Authors 101 * and Group 42, Inc. disclaim all warranties, expressed or implied, 102 * including, without limitation, the warranties of merchantability and of 103 * fitness for any purpose. The Contributing Authors and Group 42, Inc. 104 * assume no liability for direct, indirect, incidental, special, exemplary, 105 * or consequential damages, which may result from the use of the PNG 106 * Reference Library, even if advised of the possibility of such damage. 107 * 108 * Permission is hereby granted to use, copy, modify, and distribute this 109 * source code, or portions hereof, for any purpose, without fee, subject 110 * to the following restrictions: 111 * 112 * 1. The origin of this source code must not be misrepresented. 113 * 114 * 2. Altered versions must be plainly marked as such and must not 115 * be misrepresented as being the original source. 116 * 117 * 3. This Copyright notice may not be removed or altered from any 118 * source or altered source distribution. 119 * 120 * The Contributing Authors and Group 42, Inc. specifically permit, without 121 * fee, and encourage the use of this source code as a component to 122 * supporting the PNG file format in commercial products. If you use this 123 * source code in a product, acknowledgment is not required but would be 124 * appreciated. 125 * 126 * END OF COPYRIGHT NOTICE, DISCLAIMER, and LICENSE. 127 * 128 * TRADEMARK: 129 * 130 * The name "libpng" has not been registered by the Copyright owner 131 * as a trademark in any jurisdiction. However, because libpng has 132 * been distributed and maintained world-wide, continually since 1995, 133 * the Copyright owner claims "common-law trademark protection" in any 134 * jurisdiction where common-law trademark is recognized. 135 * 136 * OSI CERTIFICATION: 137 * 138 * Libpng is OSI Certified Open Source Software. OSI Certified Open Source is 139 * a certification mark of the Open Source Initiative. OSI has not addressed 140 * the additional disclaimers inserted at version 1.0.7. 141 * 142 * EXPORT CONTROL: 143 * 144 * The Copyright owner believes that the Export Control Classification 145 * Number (ECCN) for libpng is EAR99, which means not subject to export 146 * controls or International Traffic in Arms Regulations (ITAR) because 147 * it is open source, publicly available software, that does not contain 148 * any encryption software. See the EAR, paragraphs 734.3(b)(3) and 149 * 734.7(b). 150 */ 151 152 /* 153 * A "png_get_copyright" function is available, for convenient use in "about" 154 * boxes and the like: 155 * 156 * printf("%s", png_get_copyright(NULL)); 157 * 158 * Also, the PNG logo (in PNG format, of course) is supplied in the 159 * files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31). 160 */ 161 162 /* 163 * The contributing authors would like to thank all those who helped 164 * with testing, bug fixes, and patience. This wouldn't have been 165 * possible without all of you. 166 * 167 * Thanks to Frank J. T. Wojcik for helping with the documentation. 168 */ 169 170 /* Note about libpng version numbers: 171 * 172 * Due to various miscommunications, unforeseen code incompatibilities 173 * and occasional factors outside the authors' control, version numbering 174 * on the library has not always been consistent and straightforward. 175 * The following table summarizes matters since version 0.89c, which was 176 * the first widely used release: 177 * 178 * source png.h png.h shared-lib 179 * version string int version 180 * ------- ------ ----- ---------- 181 * 0.89c "1.0 beta 3" 0.89 89 1.0.89 182 * 0.90 "1.0 beta 4" 0.90 90 0.90 [should have been 2.0.90] 183 * 0.95 "1.0 beta 5" 0.95 95 0.95 [should have been 2.0.95] 184 * 0.96 "1.0 beta 6" 0.96 96 0.96 [should have been 2.0.96] 185 * 0.97b "1.00.97 beta 7" 1.00.97 97 1.0.1 [should have been 2.0.97] 186 * 0.97c 0.97 97 2.0.97 187 * 0.98 0.98 98 2.0.98 188 * 0.99 0.99 98 2.0.99 189 * 0.99a-m 0.99 99 2.0.99 190 * 1.00 1.00 100 2.1.0 [100 should be 10000] 191 * 1.0.0 (from here on, the 100 2.1.0 [100 should be 10000] 192 * 1.0.1 png.h string is 10001 2.1.0 193 * 1.0.1a-e identical to the 10002 from here on, the shared library 194 * 1.0.2 source version) 10002 is 2.V where V is the source code 195 * 1.0.2a-b 10003 version, except as noted. 196 * 1.0.3 10003 197 * 1.0.3a-d 10004 198 * 1.0.4 10004 199 * 1.0.4a-f 10005 200 * 1.0.5 (+ 2 patches) 10005 201 * 1.0.5a-d 10006 202 * 1.0.5e-r 10100 (not source compatible) 203 * 1.0.5s-v 10006 (not binary compatible) 204 * 1.0.6 (+ 3 patches) 10006 (still binary incompatible) 205 * 1.0.6d-f 10007 (still binary incompatible) 206 * 1.0.6g 10007 207 * 1.0.6h 10007 10.6h (testing xy.z so-numbering) 208 * 1.0.6i 10007 10.6i 209 * 1.0.6j 10007 2.1.0.6j (incompatible with 1.0.0) 210 * 1.0.7beta11-14 DLLNUM 10007 2.1.0.7beta11-14 (binary compatible) 211 * 1.0.7beta15-18 1 10007 2.1.0.7beta15-18 (binary compatible) 212 * 1.0.7rc1-2 1 10007 2.1.0.7rc1-2 (binary compatible) 213 * 1.0.7 1 10007 (still compatible) 214 * ... 215 * 1.0.19 10 10019 10.so.0.19[.0] 216 * ... 217 * 1.2.56 13 10256 12.so.0.56[.0] 218 * ... 219 * 1.5.27 15 10527 15.so.15.27[.0] 220 * ... 221 * 1.6.25 16 10625 16.so.16.25[.0] 222 * 223 * Henceforth the source version will match the shared-library major 224 * and minor numbers; the shared-library major version number will be 225 * used for changes in backward compatibility, as it is intended. The 226 * PNG_LIBPNG_VER macro, which is not used within libpng but is available 227 * for applications, is an unsigned integer of the form xyyzz corresponding 228 * to the source version x.y.z (leading zeros in y and z). Beta versions 229 * were given the previous public release number plus a letter, until 230 * version 1.0.6j; from then on they were given the upcoming public 231 * release number plus "betaNN" or "rcNN". 232 * 233 * Binary incompatibility exists only when applications make direct access 234 * to the info_ptr or png_ptr members through png.h, and the compiled 235 * application is loaded with a different version of the library. 236 * 237 * DLLNUM will change each time there are forward or backward changes 238 * in binary compatibility (e.g., when a new feature is added). 239 * 240 * See libpng.txt or libpng.3 for more information. The PNG specification 241 * is available as a W3C Recommendation and as an ISO Specification, 242 * <http://www.w3.org/TR/2003/REC-PNG-20031110/ 243 */ 244 245 /* 246 * Y2K compliance in libpng: 247 * ========================= 248 * 249 * September 1, 2016 250 * 251 * Since the PNG Development group is an ad-hoc body, we can't make 252 * an official declaration. 253 * 254 * This is your unofficial assurance that libpng from version 0.71 and 255 * upward through 1.6.25 are Y2K compliant. It is my belief that 256 * earlier versions were also Y2K compliant. 257 * 258 * Libpng only has two year fields. One is a 2-byte unsigned integer 259 * that will hold years up to 65535. The other, which is deprecated, 260 * holds the date in text format, and will hold years up to 9999. 261 * 262 * The integer is 263 * "png_uint_16 year" in png_time_struct. 264 * 265 * The string is 266 * "char time_buffer[29]" in png_struct. This is no longer used 267 * in libpng-1.6.x and will be removed from libpng-1.7.0. 268 * 269 * There are seven time-related functions: 270 * png.c: png_convert_to_rfc_1123_buffer() in png.c 271 * (formerly png_convert_to_rfc_1123() prior to libpng-1.5.x and 272 * png_convert_to_rfc_1152() in error prior to libpng-0.98) 273 * png_convert_from_struct_tm() in pngwrite.c, called in pngwrite.c 274 * png_convert_from_time_t() in pngwrite.c 275 * png_get_tIME() in pngget.c 276 * png_handle_tIME() in pngrutil.c, called in pngread.c 277 * png_set_tIME() in pngset.c 278 * png_write_tIME() in pngwutil.c, called in pngwrite.c 279 * 280 * All handle dates properly in a Y2K environment. The 281 * png_convert_from_time_t() function calls gmtime() to convert from system 282 * clock time, which returns (year - 1900), which we properly convert to 283 * the full 4-digit year. There is a possibility that libpng applications 284 * are not passing 4-digit years into the png_convert_to_rfc_1123_buffer() 285 * function, or that they are incorrectly passing only a 2-digit year 286 * instead of "year - 1900" into the png_convert_from_struct_tm() function, 287 * but this is not under our control. The libpng documentation has always 288 * stated that it works with 4-digit years, and the APIs have been 289 * documented as such. 290 * 291 * The tIME chunk itself is also Y2K compliant. It uses a 2-byte unsigned 292 * integer to hold the year, and can hold years as large as 65535. 293 * 294 * zlib, upon which libpng depends, is also Y2K compliant. It contains 295 * no date-related code. 296 * 297 * Glenn Randers-Pehrson 298 * libpng maintainer 299 * PNG Development Group 300 */ 301 302 #ifndef PNG_H 303 #define PNG_H 304 305 /* This is not the place to learn how to use libpng. The file libpng-manual.txt 306 * describes how to use libpng, and the file example.c summarizes it 307 * with some code on which to build. This file is useful for looking 308 * at the actual function definitions and structure components. If that 309 * file has been stripped from your copy of libpng, you can find it at 310 * <http://www.libpng.org/pub/png/libpng-manual.txt> 311 * 312 * If you just need to read a PNG file and don't want to read the documentation 313 * skip to the end of this file and read the section entitled 'simplified API'. 314 */ 315 316 /* Version information for png.h - this should match the version in png.c */ 317 #define PNG_LIBPNG_VER_STRING "1.6.25" 318 #define PNG_HEADER_VERSION_STRING " libpng version 1.6.25 - September 1, 2016\n" 319 320 #define PNG_LIBPNG_VER_SONUM 16 321 #define PNG_LIBPNG_VER_DLLNUM 16 322 323 /* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */ 324 #define PNG_LIBPNG_VER_MAJOR 1 325 #define PNG_LIBPNG_VER_MINOR 6 326 #define PNG_LIBPNG_VER_RELEASE 25 327 328 /* This should match the numeric part of the final component of 329 * PNG_LIBPNG_VER_STRING, omitting any leading zero: 330 */ 331 332 #define PNG_LIBPNG_VER_BUILD 0 333 334 /* Release Status */ 335 #define PNG_LIBPNG_BUILD_ALPHA 1 336 #define PNG_LIBPNG_BUILD_BETA 2 337 #define PNG_LIBPNG_BUILD_RC 3 338 #define PNG_LIBPNG_BUILD_STABLE 4 339 #define PNG_LIBPNG_BUILD_RELEASE_STATUS_MASK 7 340 341 /* Release-Specific Flags */ 342 #define PNG_LIBPNG_BUILD_PATCH 8 /* Can be OR'ed with 343 PNG_LIBPNG_BUILD_STABLE only */ 344 #define PNG_LIBPNG_BUILD_PRIVATE 16 /* Cannot be OR'ed with 345 PNG_LIBPNG_BUILD_SPECIAL */ 346 #define PNG_LIBPNG_BUILD_SPECIAL 32 /* Cannot be OR'ed with 347 PNG_LIBPNG_BUILD_PRIVATE */ 348 349 #define PNG_LIBPNG_BUILD_BASE_TYPE PNG_LIBPNG_BUILD_STABLE 350 351 /* Careful here. At one time, Guy wanted to use 082, but that would be octal. 352 * We must not include leading zeros. 353 * Versions 0.7 through 1.0.0 were in the range 0 to 100 here (only 354 * version 1.0.0 was mis-numbered 100 instead of 10000). From 355 * version 1.0.1 it's xxyyzz, where x=major, y=minor, z=release 356 */ 357 #define PNG_LIBPNG_VER 10625 /* 1.6.25 */ 358 359 /* Library configuration: these options cannot be changed after 360 * the library has been built. 361 */ 362 #ifndef PNGLCONF_H 363 /* If pnglibconf.h is missing, you can 364 * copy scripts/pnglibconf.h.prebuilt to pnglibconf.h 365 */ 366 # include "pnglibconf.h" 367 #endif 368 369 #ifndef PNG_VERSION_INFO_ONLY 370 /* Machine specific configuration. */ 371 # include "pngconf.h" 372 #endif 373 374 /* 375 * Added at libpng-1.2.8 376 * 377 * Ref MSDN: Private as priority over Special 378 * VS_FF_PRIVATEBUILD File *was not* built using standard release 379 * procedures. If this value is given, the StringFileInfo block must 380 * contain a PrivateBuild string. 381 * 382 * VS_FF_SPECIALBUILD File *was* built by the original company using 383 * standard release procedures but is a variation of the standard 384 * file of the same version number. If this value is given, the 385 * StringFileInfo block must contain a SpecialBuild string. 386 */ 387 388 #ifdef PNG_USER_PRIVATEBUILD /* From pnglibconf.h */ 389 # define PNG_LIBPNG_BUILD_TYPE \ 390 (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_PRIVATE) 391 #else 392 # ifdef PNG_LIBPNG_SPECIALBUILD 393 # define PNG_LIBPNG_BUILD_TYPE \ 394 (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_SPECIAL) 395 # else 396 # define PNG_LIBPNG_BUILD_TYPE (PNG_LIBPNG_BUILD_BASE_TYPE) 397 # endif 398 #endif 399 400 #ifndef PNG_VERSION_INFO_ONLY 401 402 /* Inhibit C++ name-mangling for libpng functions but not for system calls. */ 403 #ifdef __cplusplus 404 extern "C" { 405 #endif /* __cplusplus */ 406 407 /* Version information for C files, stored in png.c. This had better match 408 * the version above. 409 */ 410 #define png_libpng_ver png_get_header_ver(NULL) 411 412 /* This file is arranged in several sections: 413 * 414 * 1. [omitted] 415 * 2. Any configuration options that can be specified by for the application 416 * code when it is built. (Build time configuration is in pnglibconf.h) 417 * 3. Type definitions (base types are defined in pngconf.h), structure 418 * definitions. 419 * 4. Exported library functions. 420 * 5. Simplified API. 421 * 6. Implementation options. 422 * 423 * The library source code has additional files (principally pngpriv.h) that 424 * allow configuration of the library. 425 */ 426 427 /* Section 1: [omitted] */ 428 429 /* Section 2: run time configuration 430 * See pnglibconf.h for build time configuration 431 * 432 * Run time configuration allows the application to choose between 433 * implementations of certain arithmetic APIs. The default is set 434 * at build time and recorded in pnglibconf.h, but it is safe to 435 * override these (and only these) settings. Note that this won't 436 * change what the library does, only application code, and the 437 * settings can (and probably should) be made on a per-file basis 438 * by setting the #defines before including png.h 439 * 440 * Use macros to read integers from PNG data or use the exported 441 * functions? 442 * PNG_USE_READ_MACROS: use the macros (see below) Note that 443 * the macros evaluate their argument multiple times. 444 * PNG_NO_USE_READ_MACROS: call the relevant library function. 445 * 446 * Use the alternative algorithm for compositing alpha samples that 447 * does not use division? 448 * PNG_READ_COMPOSITE_NODIV_SUPPORTED: use the 'no division' 449 * algorithm. 450 * PNG_NO_READ_COMPOSITE_NODIV: use the 'division' algorithm. 451 * 452 * How to handle benign errors if PNG_ALLOW_BENIGN_ERRORS is 453 * false? 454 * PNG_ALLOW_BENIGN_ERRORS: map calls to the benign error 455 * APIs to png_warning. 456 * Otherwise the calls are mapped to png_error. 457 */ 458 459 /* Section 3: type definitions, including structures and compile time 460 * constants. 461 * See pngconf.h for base types that vary by machine/system 462 */ 463 464 /* This triggers a compiler error in png.c, if png.c and png.h 465 * do not agree upon the version number. 466 */ 467 typedef char* png_libpng_version_1_6_25; 468 469 /* Basic control structions. Read libpng-manual.txt or libpng.3 for more info. 470 * 471 * png_struct is the cache of information used while reading or writing a single 472 * PNG file. One of these is always required, although the simplified API 473 * (below) hides the creation and destruction of it. 474 */ 475 typedef struct png_struct_def png_struct; 476 typedef const png_struct * png_const_structp; 477 typedef png_struct * png_structp; 478 typedef png_struct * * png_structpp; 479 480 /* png_info contains information read from or to be written to a PNG file. One 481 * or more of these must exist while reading or creating a PNG file. The 482 * information is not used by libpng during read but is used to control what 483 * gets written when a PNG file is created. "png_get_" function calls read 484 * information during read and "png_set_" functions calls write information 485 * when creating a PNG. 486 * been moved into a separate header file that is not accessible to 487 * applications. Read libpng-manual.txt or libpng.3 for more info. 488 */ 489 typedef struct png_info_def png_info; 490 typedef png_info * png_infop; 491 typedef const png_info * png_const_infop; 492 typedef png_info * * png_infopp; 493 494 /* Types with names ending 'p' are pointer types. The corresponding types with 495 * names ending 'rp' are identical pointer types except that the pointer is 496 * marked 'restrict', which means that it is the only pointer to the object 497 * passed to the function. Applications should not use the 'restrict' types; 498 * it is always valid to pass 'p' to a pointer with a function argument of the 499 * corresponding 'rp' type. Different compilers have different rules with 500 * regard to type matching in the presence of 'restrict'. For backward 501 * compatibility libpng callbacks never have 'restrict' in their parameters and, 502 * consequentially, writing portable application code is extremely difficult if 503 * an attempt is made to use 'restrict'. 504 */ 505 typedef png_struct * PNG_RESTRICT png_structrp; 506 typedef const png_struct * PNG_RESTRICT png_const_structrp; 507 typedef png_info * PNG_RESTRICT png_inforp; 508 typedef const png_info * PNG_RESTRICT png_const_inforp; 509 510 /* Three color definitions. The order of the red, green, and blue, (and the 511 * exact size) is not important, although the size of the fields need to 512 * be png_byte or png_uint_16 (as defined below). 513 */ 514 typedef struct png_color_struct 515 { 516 png_byte red; 517 png_byte green; 518 png_byte blue; 519 } png_color; 520 typedef png_color * png_colorp; 521 typedef const png_color * png_const_colorp; 522 typedef png_color * * png_colorpp; 523 524 typedef struct png_color_16_struct 525 { 526 png_byte index; /* used for palette files */ 527 png_uint_16 red; /* for use in red green blue files */ 528 png_uint_16 green; 529 png_uint_16 blue; 530 png_uint_16 gray; /* for use in grayscale files */ 531 } png_color_16; 532 typedef png_color_16 * png_color_16p; 533 typedef const png_color_16 * png_const_color_16p; 534 typedef png_color_16 * * png_color_16pp; 535 536 typedef struct png_color_8_struct 537 { 538 png_byte red; /* for use in red green blue files */ 539 png_byte green; 540 png_byte blue; 541 png_byte gray; /* for use in grayscale files */ 542 png_byte alpha; /* for alpha channel files */ 543 } png_color_8; 544 typedef png_color_8 * png_color_8p; 545 typedef const png_color_8 * png_const_color_8p; 546 typedef png_color_8 * * png_color_8pp; 547 548 /* 549 * The following two structures are used for the in-core representation 550 * of sPLT chunks. 551 */ 552 typedef struct png_sPLT_entry_struct 553 { 554 png_uint_16 red; 555 png_uint_16 green; 556 png_uint_16 blue; 557 png_uint_16 alpha; 558 png_uint_16 frequency; 559 } png_sPLT_entry; 560 typedef png_sPLT_entry * png_sPLT_entryp; 561 typedef const png_sPLT_entry * png_const_sPLT_entryp; 562 typedef png_sPLT_entry * * png_sPLT_entrypp; 563 564 /* When the depth of the sPLT palette is 8 bits, the color and alpha samples 565 * occupy the LSB of their respective members, and the MSB of each member 566 * is zero-filled. The frequency member always occupies the full 16 bits. 567 */ 568 569 typedef struct png_sPLT_struct 570 { 571 png_charp name; /* palette name */ 572 png_byte depth; /* depth of palette samples */ 573 png_sPLT_entryp entries; /* palette entries */ 574 png_int_32 nentries; /* number of palette entries */ 575 } png_sPLT_t; 576 typedef png_sPLT_t * png_sPLT_tp; 577 typedef const png_sPLT_t * png_const_sPLT_tp; 578 typedef png_sPLT_t * * png_sPLT_tpp; 579 580 #ifdef PNG_TEXT_SUPPORTED 581 /* png_text holds the contents of a text/ztxt/itxt chunk in a PNG file, 582 * and whether that contents is compressed or not. The "key" field 583 * points to a regular zero-terminated C string. The "text" fields can be a 584 * regular C string, an empty string, or a NULL pointer. 585 * However, the structure returned by png_get_text() will always contain 586 * the "text" field as a regular zero-terminated C string (possibly 587 * empty), never a NULL pointer, so it can be safely used in printf() and 588 * other string-handling functions. Note that the "itxt_length", "lang", and 589 * "lang_key" members of the structure only exist when the library is built 590 * with iTXt chunk support. Prior to libpng-1.4.0 the library was built by 591 * default without iTXt support. Also note that when iTXt *is* supported, 592 * the "lang" and "lang_key" fields contain NULL pointers when the 593 * "compression" field contains * PNG_TEXT_COMPRESSION_NONE or 594 * PNG_TEXT_COMPRESSION_zTXt. Note that the "compression value" is not the 595 * same as what appears in the PNG tEXt/zTXt/iTXt chunk's "compression flag" 596 * which is always 0 or 1, or its "compression method" which is always 0. 597 */ 598 typedef struct png_text_struct 599 { 600 int compression; /* compression value: 601 -1: tEXt, none 602 0: zTXt, deflate 603 1: iTXt, none 604 2: iTXt, deflate */ 605 png_charp key; /* keyword, 1-79 character description of "text" */ 606 png_charp text; /* comment, may be an empty string (ie "") 607 or a NULL pointer */ 608 png_size_t text_length; /* length of the text string */ 609 png_size_t itxt_length; /* length of the itxt string */ 610 png_charp lang; /* language code, 0-79 characters 611 or a NULL pointer */ 612 png_charp lang_key; /* keyword translated UTF-8 string, 0 or more 613 chars or a NULL pointer */ 614 } png_text; 615 typedef png_text * png_textp; 616 typedef const png_text * png_const_textp; 617 typedef png_text * * png_textpp; 618 #endif 619 620 /* Supported compression types for text in PNG files (tEXt, and zTXt). 621 * The values of the PNG_TEXT_COMPRESSION_ defines should NOT be changed. */ 622 #define PNG_TEXT_COMPRESSION_NONE_WR -3 623 #define PNG_TEXT_COMPRESSION_zTXt_WR -2 624 #define PNG_TEXT_COMPRESSION_NONE -1 625 #define PNG_TEXT_COMPRESSION_zTXt 0 626 #define PNG_ITXT_COMPRESSION_NONE 1 627 #define PNG_ITXT_COMPRESSION_zTXt 2 628 #define PNG_TEXT_COMPRESSION_LAST 3 /* Not a valid value */ 629 630 /* png_time is a way to hold the time in an machine independent way. 631 * Two conversions are provided, both from time_t and struct tm. There 632 * is no portable way to convert to either of these structures, as far 633 * as I know. If you know of a portable way, send it to me. As a side 634 * note - PNG has always been Year 2000 compliant! 635 */ 636 typedef struct png_time_struct 637 { 638 png_uint_16 year; /* full year, as in, 1995 */ 639 png_byte month; /* month of year, 1 - 12 */ 640 png_byte day; /* day of month, 1 - 31 */ 641 png_byte hour; /* hour of day, 0 - 23 */ 642 png_byte minute; /* minute of hour, 0 - 59 */ 643 png_byte second; /* second of minute, 0 - 60 (for leap seconds) */ 644 } png_time; 645 typedef png_time * png_timep; 646 typedef const png_time * png_const_timep; 647 typedef png_time * * png_timepp; 648 649 #if defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED) ||\ 650 defined(PNG_USER_CHUNKS_SUPPORTED) 651 /* png_unknown_chunk is a structure to hold queued chunks for which there is 652 * no specific support. The idea is that we can use this to queue 653 * up private chunks for output even though the library doesn't actually 654 * know about their semantics. 655 * 656 * The data in the structure is set by libpng on read and used on write. 657 */ 658 typedef struct png_unknown_chunk_t 659 { 660 png_byte name[5]; /* Textual chunk name with '\0' terminator */ 661 png_byte *data; /* Data, should not be modified on read! */ 662 png_size_t size; 663 664 /* On write 'location' must be set using the flag values listed below. 665 * Notice that on read it is set by libpng however the values stored have 666 * more bits set than are listed below. Always treat the value as a 667 * bitmask. On write set only one bit - setting multiple bits may cause the 668 * chunk to be written in multiple places. 669 */ 670 png_byte location; /* mode of operation at read time */ 671 } 672 png_unknown_chunk; 673 674 typedef png_unknown_chunk * png_unknown_chunkp; 675 typedef const png_unknown_chunk * png_const_unknown_chunkp; 676 typedef png_unknown_chunk * * png_unknown_chunkpp; 677 #endif 678 679 /* Flag values for the unknown chunk location byte. */ 680 #define PNG_HAVE_IHDR 0x01 681 #define PNG_HAVE_PLTE 0x02 682 #define PNG_AFTER_IDAT 0x08 683 684 /* Maximum positive integer used in PNG is (2^31)-1 */ 685 #define PNG_UINT_31_MAX ((png_uint_32)0x7fffffffL) 686 #define PNG_UINT_32_MAX ((png_uint_32)(-1)) 687 #define PNG_SIZE_MAX ((png_size_t)(-1)) 688 689 /* These are constants for fixed point values encoded in the 690 * PNG specification manner (x100000) 691 */ 692 #define PNG_FP_1 100000 693 #define PNG_FP_HALF 50000 694 #define PNG_FP_MAX ((png_fixed_point)0x7fffffffL) 695 #define PNG_FP_MIN (-PNG_FP_MAX) 696 697 /* These describe the color_type field in png_info. */ 698 /* color type masks */ 699 #define PNG_COLOR_MASK_PALETTE 1 700 #define PNG_COLOR_MASK_COLOR 2 701 #define PNG_COLOR_MASK_ALPHA 4 702 703 /* color types. Note that not all combinations are legal */ 704 #define PNG_COLOR_TYPE_GRAY 0 705 #define PNG_COLOR_TYPE_PALETTE (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE) 706 #define PNG_COLOR_TYPE_RGB (PNG_COLOR_MASK_COLOR) 707 #define PNG_COLOR_TYPE_RGB_ALPHA (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_ALPHA) 708 #define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA) 709 /* aliases */ 710 #define PNG_COLOR_TYPE_RGBA PNG_COLOR_TYPE_RGB_ALPHA 711 #define PNG_COLOR_TYPE_GA PNG_COLOR_TYPE_GRAY_ALPHA 712 713 /* This is for compression type. PNG 1.0-1.2 only define the single type. */ 714 #define PNG_COMPRESSION_TYPE_BASE 0 /* Deflate method 8, 32K window */ 715 #define PNG_COMPRESSION_TYPE_DEFAULT PNG_COMPRESSION_TYPE_BASE 716 717 /* This is for filter type. PNG 1.0-1.2 only define the single type. */ 718 #define PNG_FILTER_TYPE_BASE 0 /* Single row per-byte filtering */ 719 #define PNG_INTRAPIXEL_DIFFERENCING 64 /* Used only in MNG datastreams */ 720 #define PNG_FILTER_TYPE_DEFAULT PNG_FILTER_TYPE_BASE 721 722 /* These are for the interlacing type. These values should NOT be changed. */ 723 #define PNG_INTERLACE_NONE 0 /* Non-interlaced image */ 724 #define PNG_INTERLACE_ADAM7 1 /* Adam7 interlacing */ 725 #define PNG_INTERLACE_LAST 2 /* Not a valid value */ 726 727 /* These are for the oFFs chunk. These values should NOT be changed. */ 728 #define PNG_OFFSET_PIXEL 0 /* Offset in pixels */ 729 #define PNG_OFFSET_MICROMETER 1 /* Offset in micrometers (1/10^6 meter) */ 730 #define PNG_OFFSET_LAST 2 /* Not a valid value */ 731 732 /* These are for the pCAL chunk. These values should NOT be changed. */ 733 #define PNG_EQUATION_LINEAR 0 /* Linear transformation */ 734 #define PNG_EQUATION_BASE_E 1 /* Exponential base e transform */ 735 #define PNG_EQUATION_ARBITRARY 2 /* Arbitrary base exponential transform */ 736 #define PNG_EQUATION_HYPERBOLIC 3 /* Hyperbolic sine transformation */ 737 #define PNG_EQUATION_LAST 4 /* Not a valid value */ 738 739 /* These are for the sCAL chunk. These values should NOT be changed. */ 740 #define PNG_SCALE_UNKNOWN 0 /* unknown unit (image scale) */ 741 #define PNG_SCALE_METER 1 /* meters per pixel */ 742 #define PNG_SCALE_RADIAN 2 /* radians per pixel */ 743 #define PNG_SCALE_LAST 3 /* Not a valid value */ 744 745 /* These are for the pHYs chunk. These values should NOT be changed. */ 746 #define PNG_RESOLUTION_UNKNOWN 0 /* pixels/unknown unit (aspect ratio) */ 747 #define PNG_RESOLUTION_METER 1 /* pixels/meter */ 748 #define PNG_RESOLUTION_LAST 2 /* Not a valid value */ 749 750 /* These are for the sRGB chunk. These values should NOT be changed. */ 751 #define PNG_sRGB_INTENT_PERCEPTUAL 0 752 #define PNG_sRGB_INTENT_RELATIVE 1 753 #define PNG_sRGB_INTENT_SATURATION 2 754 #define PNG_sRGB_INTENT_ABSOLUTE 3 755 #define PNG_sRGB_INTENT_LAST 4 /* Not a valid value */ 756 757 /* This is for text chunks */ 758 #define PNG_KEYWORD_MAX_LENGTH 79 759 760 /* Maximum number of entries in PLTE/sPLT/tRNS arrays */ 761 #define PNG_MAX_PALETTE_LENGTH 256 762 763 /* These determine if an ancillary chunk's data has been successfully read 764 * from the PNG header, or if the application has filled in the corresponding 765 * data in the info_struct to be written into the output file. The values 766 * of the PNG_INFO_<chunk> defines should NOT be changed. 767 */ 768 #define PNG_INFO_gAMA 0x0001U 769 #define PNG_INFO_sBIT 0x0002U 770 #define PNG_INFO_cHRM 0x0004U 771 #define PNG_INFO_PLTE 0x0008U 772 #define PNG_INFO_tRNS 0x0010U 773 #define PNG_INFO_bKGD 0x0020U 774 #define PNG_INFO_hIST 0x0040U 775 #define PNG_INFO_pHYs 0x0080U 776 #define PNG_INFO_oFFs 0x0100U 777 #define PNG_INFO_tIME 0x0200U 778 #define PNG_INFO_pCAL 0x0400U 779 #define PNG_INFO_sRGB 0x0800U /* GR-P, 0.96a */ 780 #define PNG_INFO_iCCP 0x1000U /* ESR, 1.0.6 */ 781 #define PNG_INFO_sPLT 0x2000U /* ESR, 1.0.6 */ 782 #define PNG_INFO_sCAL 0x4000U /* ESR, 1.0.6 */ 783 #define PNG_INFO_IDAT 0x8000U /* ESR, 1.0.6 */ 784 785 /* This is used for the transformation routines, as some of them 786 * change these values for the row. It also should enable using 787 * the routines for other purposes. 788 */ 789 typedef struct png_row_info_struct 790 { 791 png_uint_32 width; /* width of row */ 792 png_size_t rowbytes; /* number of bytes in row */ 793 png_byte color_type; /* color type of row */ 794 png_byte bit_depth; /* bit depth of row */ 795 png_byte channels; /* number of channels (1, 2, 3, or 4) */ 796 png_byte pixel_depth; /* bits per pixel (depth * channels) */ 797 } png_row_info; 798 799 typedef png_row_info * png_row_infop; 800 typedef png_row_info * * png_row_infopp; 801 802 /* These are the function types for the I/O functions and for the functions 803 * that allow the user to override the default I/O functions with his or her 804 * own. The png_error_ptr type should match that of user-supplied warning 805 * and error functions, while the png_rw_ptr type should match that of the 806 * user read/write data functions. Note that the 'write' function must not 807 * modify the buffer it is passed. The 'read' function, on the other hand, is 808 * expected to return the read data in the buffer. 809 */ 810 typedef PNG_CALLBACK(void, *png_error_ptr, (png_structp, png_const_charp)); 811 typedef PNG_CALLBACK(void, *png_rw_ptr, (png_structp, png_bytep, png_size_t)); 812 typedef PNG_CALLBACK(void, *png_flush_ptr, (png_structp)); 813 typedef PNG_CALLBACK(void, *png_read_status_ptr, (png_structp, png_uint_32, 814 int)); 815 typedef PNG_CALLBACK(void, *png_write_status_ptr, (png_structp, png_uint_32, 816 int)); 817 818 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED 819 typedef PNG_CALLBACK(void, *png_progressive_info_ptr, (png_structp, png_infop)); 820 typedef PNG_CALLBACK(void, *png_progressive_end_ptr, (png_structp, png_infop)); 821 822 /* The following callback receives png_uint_32 row_number, int pass for the 823 * png_bytep data of the row. When transforming an interlaced image the 824 * row number is the row number within the sub-image of the interlace pass, so 825 * the value will increase to the height of the sub-image (not the full image) 826 * then reset to 0 for the next pass. 827 * 828 * Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to 829 * find the output pixel (x,y) given an interlaced sub-image pixel 830 * (row,col,pass). (See below for these macros.) 831 */ 832 typedef PNG_CALLBACK(void, *png_progressive_row_ptr, (png_structp, png_bytep, 833 png_uint_32, int)); 834 #endif 835 836 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \ 837 defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) 838 typedef PNG_CALLBACK(void, *png_user_transform_ptr, (png_structp, png_row_infop, 839 png_bytep)); 840 #endif 841 842 #ifdef PNG_USER_CHUNKS_SUPPORTED 843 typedef PNG_CALLBACK(int, *png_user_chunk_ptr, (png_structp, 844 png_unknown_chunkp)); 845 #endif 846 #ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED 847 /* not used anywhere */ 848 /* typedef PNG_CALLBACK(void, *png_unknown_chunk_ptr, (png_structp)); */ 849 #endif 850 851 #ifdef PNG_SETJMP_SUPPORTED 852 /* This must match the function definition in <setjmp.h>, and the application 853 * must include this before png.h to obtain the definition of jmp_buf. The 854 * function is required to be PNG_NORETURN, but this is not checked. If the 855 * function does return the application will crash via an abort() or similar 856 * system level call. 857 * 858 * If you get a warning here while building the library you may need to make 859 * changes to ensure that pnglibconf.h records the calling convention used by 860 * your compiler. This may be very difficult - try using a different compiler 861 * to build the library! 862 */ 863 PNG_FUNCTION(void, (PNGCAPI *png_longjmp_ptr), PNGARG((jmp_buf, int)), typedef); 864 #endif 865 866 /* Transform masks for the high-level interface */ 867 #define PNG_TRANSFORM_IDENTITY 0x0000 /* read and write */ 868 #define PNG_TRANSFORM_STRIP_16 0x0001 /* read only */ 869 #define PNG_TRANSFORM_STRIP_ALPHA 0x0002 /* read only */ 870 #define PNG_TRANSFORM_PACKING 0x0004 /* read and write */ 871 #define PNG_TRANSFORM_PACKSWAP 0x0008 /* read and write */ 872 #define PNG_TRANSFORM_EXPAND 0x0010 /* read only */ 873 #define PNG_TRANSFORM_INVERT_MONO 0x0020 /* read and write */ 874 #define PNG_TRANSFORM_SHIFT 0x0040 /* read and write */ 875 #define PNG_TRANSFORM_BGR 0x0080 /* read and write */ 876 #define PNG_TRANSFORM_SWAP_ALPHA 0x0100 /* read and write */ 877 #define PNG_TRANSFORM_SWAP_ENDIAN 0x0200 /* read and write */ 878 #define PNG_TRANSFORM_INVERT_ALPHA 0x0400 /* read and write */ 879 #define PNG_TRANSFORM_STRIP_FILLER 0x0800 /* write only */ 880 /* Added to libpng-1.2.34 */ 881 #define PNG_TRANSFORM_STRIP_FILLER_BEFORE PNG_TRANSFORM_STRIP_FILLER 882 #define PNG_TRANSFORM_STRIP_FILLER_AFTER 0x1000 /* write only */ 883 /* Added to libpng-1.4.0 */ 884 #define PNG_TRANSFORM_GRAY_TO_RGB 0x2000 /* read only */ 885 /* Added to libpng-1.5.4 */ 886 #define PNG_TRANSFORM_EXPAND_16 0x4000 /* read only */ 887 #if INT_MAX >= 0x8000 /* else this might break */ 888 #define PNG_TRANSFORM_SCALE_16 0x8000 /* read only */ 889 #endif 890 891 /* Flags for MNG supported features */ 892 #define PNG_FLAG_MNG_EMPTY_PLTE 0x01 893 #define PNG_FLAG_MNG_FILTER_64 0x04 894 #define PNG_ALL_MNG_FEATURES 0x05 895 896 /* NOTE: prior to 1.5 these functions had no 'API' style declaration, 897 * this allowed the zlib default functions to be used on Windows 898 * platforms. In 1.5 the zlib default malloc (which just calls malloc and 899 * ignores the first argument) should be completely compatible with the 900 * following. 901 */ 902 typedef PNG_CALLBACK(png_voidp, *png_malloc_ptr, (png_structp, 903 png_alloc_size_t)); 904 typedef PNG_CALLBACK(void, *png_free_ptr, (png_structp, png_voidp)); 905 906 /* Section 4: exported functions 907 * Here are the function definitions most commonly used. This is not 908 * the place to find out how to use libpng. See libpng-manual.txt for the 909 * full explanation, see example.c for the summary. This just provides 910 * a simple one line description of the use of each function. 911 * 912 * The PNG_EXPORT() and PNG_EXPORTA() macros used below are defined in 913 * pngconf.h and in the *.dfn files in the scripts directory. 914 * 915 * PNG_EXPORT(ordinal, type, name, (args)); 916 * 917 * ordinal: ordinal that is used while building 918 * *.def files. The ordinal value is only 919 * relevant when preprocessing png.h with 920 * the *.dfn files for building symbol table 921 * entries, and are removed by pngconf.h. 922 * type: return type of the function 923 * name: function name 924 * args: function arguments, with types 925 * 926 * When we wish to append attributes to a function prototype we use 927 * the PNG_EXPORTA() macro instead. 928 * 929 * PNG_EXPORTA(ordinal, type, name, (args), attributes); 930 * 931 * ordinal, type, name, and args: same as in PNG_EXPORT(). 932 * attributes: function attributes 933 */ 934 935 /* Returns the version number of the library */ 936 PNG_EXPORT(1, png_uint_32, png_access_version_number, (void)); 937 938 /* Tell lib we have already handled the first <num_bytes> magic bytes. 939 * Handling more than 8 bytes from the beginning of the file is an error. 940 */ 941 PNG_EXPORT(2, void, png_set_sig_bytes, (png_structrp png_ptr, int num_bytes)); 942 943 /* Check sig[start] through sig[start + num_to_check - 1] to see if it's a 944 * PNG file. Returns zero if the supplied bytes match the 8-byte PNG 945 * signature, and non-zero otherwise. Having num_to_check == 0 or 946 * start > 7 will always fail (ie return non-zero). 947 */ 948 PNG_EXPORT(3, int, png_sig_cmp, (png_const_bytep sig, png_size_t start, 949 png_size_t num_to_check)); 950 951 /* Simple signature checking function. This is the same as calling 952 * png_check_sig(sig, n) := !png_sig_cmp(sig, 0, n). 953 */ 954 #define png_check_sig(sig, n) !png_sig_cmp((sig), 0, (n)) 955 956 /* Allocate and initialize png_ptr struct for reading, and any other memory. */ 957 PNG_EXPORTA(4, png_structp, png_create_read_struct, 958 (png_const_charp user_png_ver, png_voidp error_ptr, 959 png_error_ptr error_fn, png_error_ptr warn_fn), 960 PNG_ALLOCATED); 961 962 /* Allocate and initialize png_ptr struct for writing, and any other memory */ 963 PNG_EXPORTA(5, png_structp, png_create_write_struct, 964 (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn, 965 png_error_ptr warn_fn), 966 PNG_ALLOCATED); 967 968 PNG_EXPORT(6, png_size_t, png_get_compression_buffer_size, 969 (png_const_structrp png_ptr)); 970 971 PNG_EXPORT(7, void, png_set_compression_buffer_size, (png_structrp png_ptr, 972 png_size_t size)); 973 974 /* Moved from pngconf.h in 1.4.0 and modified to ensure setjmp/longjmp 975 * match up. 976 */ 977 #ifdef PNG_SETJMP_SUPPORTED 978 /* This function returns the jmp_buf built in to *png_ptr. It must be 979 * supplied with an appropriate 'longjmp' function to use on that jmp_buf 980 * unless the default error function is overridden in which case NULL is 981 * acceptable. The size of the jmp_buf is checked against the actual size 982 * allocated by the library - the call will return NULL on a mismatch 983 * indicating an ABI mismatch. 984 */ 985 PNG_EXPORT(8, jmp_buf*, png_set_longjmp_fn, (png_structrp png_ptr, 986 png_longjmp_ptr longjmp_fn, size_t jmp_buf_size)); 987 # define png_jmpbuf(png_ptr) \ 988 (*png_set_longjmp_fn((png_ptr), longjmp, (sizeof (jmp_buf)))) 989 #else 990 # define png_jmpbuf(png_ptr) \ 991 (LIBPNG_WAS_COMPILED_WITH__PNG_NO_SETJMP) 992 #endif 993 /* This function should be used by libpng applications in place of 994 * longjmp(png_ptr->jmpbuf, val). If longjmp_fn() has been set, it 995 * will use it; otherwise it will call PNG_ABORT(). This function was 996 * added in libpng-1.5.0. 997 */ 998 PNG_EXPORTA(9, void, png_longjmp, (png_const_structrp png_ptr, int val), 999 PNG_NORETURN); 1000 1001 #ifdef PNG_READ_SUPPORTED 1002 /* Reset the compression stream */ 1003 PNG_EXPORTA(10, int, png_reset_zstream, (png_structrp png_ptr), PNG_DEPRECATED); 1004 #endif 1005 1006 /* New functions added in libpng-1.0.2 (not enabled by default until 1.2.0) */ 1007 #ifdef PNG_USER_MEM_SUPPORTED 1008 PNG_EXPORTA(11, png_structp, png_create_read_struct_2, 1009 (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn, 1010 png_error_ptr warn_fn, 1011 png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn), 1012 PNG_ALLOCATED); 1013 PNG_EXPORTA(12, png_structp, png_create_write_struct_2, 1014 (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn, 1015 png_error_ptr warn_fn, 1016 png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn), 1017 PNG_ALLOCATED); 1018 #endif 1019 1020 /* Write the PNG file signature. */ 1021 PNG_EXPORT(13, void, png_write_sig, (png_structrp png_ptr)); 1022 1023 /* Write a PNG chunk - size, type, (optional) data, CRC. */ 1024 PNG_EXPORT(14, void, png_write_chunk, (png_structrp png_ptr, png_const_bytep 1025 chunk_name, png_const_bytep data, png_size_t length)); 1026 1027 /* Write the start of a PNG chunk - length and chunk name. */ 1028 PNG_EXPORT(15, void, png_write_chunk_start, (png_structrp png_ptr, 1029 png_const_bytep chunk_name, png_uint_32 length)); 1030 1031 /* Write the data of a PNG chunk started with png_write_chunk_start(). */ 1032 PNG_EXPORT(16, void, png_write_chunk_data, (png_structrp png_ptr, 1033 png_const_bytep data, png_size_t length)); 1034 1035 /* Finish a chunk started with png_write_chunk_start() (includes CRC). */ 1036 PNG_EXPORT(17, void, png_write_chunk_end, (png_structrp png_ptr)); 1037 1038 /* Allocate and initialize the info structure */ 1039 PNG_EXPORTA(18, png_infop, png_create_info_struct, (png_const_structrp png_ptr), 1040 PNG_ALLOCATED); 1041 1042 /* DEPRECATED: this function allowed init structures to be created using the 1043 * default allocation method (typically malloc). Use is deprecated in 1.6.0 and 1044 * the API will be removed in the future. 1045 */ 1046 PNG_EXPORTA(19, void, png_info_init_3, (png_infopp info_ptr, 1047 png_size_t png_info_struct_size), PNG_DEPRECATED); 1048 1049 /* Writes all the PNG information before the image. */ 1050 PNG_EXPORT(20, void, png_write_info_before_PLTE, 1051 (png_structrp png_ptr, png_const_inforp info_ptr)); 1052 PNG_EXPORT(21, void, png_write_info, 1053 (png_structrp png_ptr, png_const_inforp info_ptr)); 1054 1055 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED 1056 /* Read the information before the actual image data. */ 1057 PNG_EXPORT(22, void, png_read_info, 1058 (png_structrp png_ptr, png_inforp info_ptr)); 1059 #endif 1060 1061 #ifdef PNG_TIME_RFC1123_SUPPORTED 1062 /* Convert to a US string format: there is no localization support in this 1063 * routine. The original implementation used a 29 character buffer in 1064 * png_struct, this will be removed in future versions. 1065 */ 1066 #if PNG_LIBPNG_VER < 10700 1067 /* To do: remove this from libpng17 (and from libpng17/png.c and pngstruct.h) */ 1068 PNG_EXPORTA(23, png_const_charp, png_convert_to_rfc1123, (png_structrp png_ptr, 1069 png_const_timep ptime),PNG_DEPRECATED); 1070 #endif 1071 PNG_EXPORT(241, int, png_convert_to_rfc1123_buffer, (char out[29], 1072 png_const_timep ptime)); 1073 #endif 1074 1075 #ifdef PNG_CONVERT_tIME_SUPPORTED 1076 /* Convert from a struct tm to png_time */ 1077 PNG_EXPORT(24, void, png_convert_from_struct_tm, (png_timep ptime, 1078 const struct tm * ttime)); 1079 1080 /* Convert from time_t to png_time. Uses gmtime() */ 1081 PNG_EXPORT(25, void, png_convert_from_time_t, (png_timep ptime, time_t ttime)); 1082 #endif /* CONVERT_tIME */ 1083 1084 #ifdef PNG_READ_EXPAND_SUPPORTED 1085 /* Expand data to 24-bit RGB, or 8-bit grayscale, with alpha if available. */ 1086 PNG_EXPORT(26, void, png_set_expand, (png_structrp png_ptr)); 1087 PNG_EXPORT(27, void, png_set_expand_gray_1_2_4_to_8, (png_structrp png_ptr)); 1088 PNG_EXPORT(28, void, png_set_palette_to_rgb, (png_structrp png_ptr)); 1089 PNG_EXPORT(29, void, png_set_tRNS_to_alpha, (png_structrp png_ptr)); 1090 #endif 1091 1092 #ifdef PNG_READ_EXPAND_16_SUPPORTED 1093 /* Expand to 16-bit channels, forces conversion of palette to RGB and expansion 1094 * of a tRNS chunk if present. 1095 */ 1096 PNG_EXPORT(221, void, png_set_expand_16, (png_structrp png_ptr)); 1097 #endif 1098 1099 #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED) 1100 /* Use blue, green, red order for pixels. */ 1101 PNG_EXPORT(30, void, png_set_bgr, (png_structrp png_ptr)); 1102 #endif 1103 1104 #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED 1105 /* Expand the grayscale to 24-bit RGB if necessary. */ 1106 PNG_EXPORT(31, void, png_set_gray_to_rgb, (png_structrp png_ptr)); 1107 #endif 1108 1109 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED 1110 /* Reduce RGB to grayscale. */ 1111 #define PNG_ERROR_ACTION_NONE 1 1112 #define PNG_ERROR_ACTION_WARN 2 1113 #define PNG_ERROR_ACTION_ERROR 3 1114 #define PNG_RGB_TO_GRAY_DEFAULT (-1)/*for red/green coefficients*/ 1115 1116 PNG_FP_EXPORT(32, void, png_set_rgb_to_gray, (png_structrp png_ptr, 1117 int error_action, double red, double green)) 1118 PNG_FIXED_EXPORT(33, void, png_set_rgb_to_gray_fixed, (png_structrp png_ptr, 1119 int error_action, png_fixed_point red, png_fixed_point green)) 1120 1121 PNG_EXPORT(34, png_byte, png_get_rgb_to_gray_status, (png_const_structrp 1122 png_ptr)); 1123 #endif 1124 1125 #ifdef PNG_BUILD_GRAYSCALE_PALETTE_SUPPORTED 1126 PNG_EXPORT(35, void, png_build_grayscale_palette, (int bit_depth, 1127 png_colorp palette)); 1128 #endif 1129 1130 #ifdef PNG_READ_ALPHA_MODE_SUPPORTED 1131 /* How the alpha channel is interpreted - this affects how the color channels 1132 * of a PNG file are returned to the calling application when an alpha channel, 1133 * or a tRNS chunk in a palette file, is present. 1134 * 1135 * This has no effect on the way pixels are written into a PNG output 1136 * datastream. The color samples in a PNG datastream are never premultiplied 1137 * with the alpha samples. 1138 * 1139 * The default is to return data according to the PNG specification: the alpha 1140 * channel is a linear measure of the contribution of the pixel to the 1141 * corresponding composited pixel, and the color channels are unassociated 1142 * (not premultiplied). The gamma encoded color channels must be scaled 1143 * according to the contribution and to do this it is necessary to undo 1144 * the encoding, scale the color values, perform the composition and reencode 1145 * the values. This is the 'PNG' mode. 1146 * 1147 * The alternative is to 'associate' the alpha with the color information by 1148 * storing color channel values that have been scaled by the alpha. 1149 * image. These are the 'STANDARD', 'ASSOCIATED' or 'PREMULTIPLIED' modes 1150 * (the latter being the two common names for associated alpha color channels). 1151 * 1152 * For the 'OPTIMIZED' mode, a pixel is treated as opaque only if the alpha 1153 * value is equal to the maximum value. 1154 * 1155 * The final choice is to gamma encode the alpha channel as well. This is 1156 * broken because, in practice, no implementation that uses this choice 1157 * correctly undoes the encoding before handling alpha composition. Use this 1158 * choice only if other serious errors in the software or hardware you use 1159 * mandate it; the typical serious error is for dark halos to appear around 1160 * opaque areas of the composited PNG image because of arithmetic overflow. 1161 * 1162 * The API function png_set_alpha_mode specifies which of these choices to use 1163 * with an enumerated 'mode' value and the gamma of the required output: 1164 */ 1165 #define PNG_ALPHA_PNG 0 /* according to the PNG standard */ 1166 #define PNG_ALPHA_STANDARD 1 /* according to Porter/Duff */ 1167 #define PNG_ALPHA_ASSOCIATED 1 /* as above; this is the normal practice */ 1168 #define PNG_ALPHA_PREMULTIPLIED 1 /* as above */ 1169 #define PNG_ALPHA_OPTIMIZED 2 /* 'PNG' for opaque pixels, else 'STANDARD' */ 1170 #define PNG_ALPHA_BROKEN 3 /* the alpha channel is gamma encoded */ 1171 1172 PNG_FP_EXPORT(227, void, png_set_alpha_mode, (png_structrp png_ptr, int mode, 1173 double output_gamma)) 1174 PNG_FIXED_EXPORT(228, void, png_set_alpha_mode_fixed, (png_structrp png_ptr, 1175 int mode, png_fixed_point output_gamma)) 1176 #endif 1177 1178 #if defined(PNG_GAMMA_SUPPORTED) || defined(PNG_READ_ALPHA_MODE_SUPPORTED) 1179 /* The output_gamma value is a screen gamma in libpng terminology: it expresses 1180 * how to decode the output values, not how they are encoded. 1181 */ 1182 #define PNG_DEFAULT_sRGB -1 /* sRGB gamma and color space */ 1183 #define PNG_GAMMA_MAC_18 -2 /* Old Mac '1.8' gamma and color space */ 1184 #define PNG_GAMMA_sRGB 220000 /* Television standards--matches sRGB gamma */ 1185 #define PNG_GAMMA_LINEAR PNG_FP_1 /* Linear */ 1186 #endif 1187 1188 /* The following are examples of calls to png_set_alpha_mode to achieve the 1189 * required overall gamma correction and, where necessary, alpha 1190 * premultiplication. 1191 * 1192 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB); 1193 * This is the default libpng handling of the alpha channel - it is not 1194 * pre-multiplied into the color components. In addition the call states 1195 * that the output is for a sRGB system and causes all PNG files without gAMA 1196 * chunks to be assumed to be encoded using sRGB. 1197 * 1198 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC); 1199 * In this case the output is assumed to be something like an sRGB conformant 1200 * display preceeded by a power-law lookup table of power 1.45. This is how 1201 * early Mac systems behaved. 1202 * 1203 * png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_GAMMA_LINEAR); 1204 * This is the classic Jim Blinn approach and will work in academic 1205 * environments where everything is done by the book. It has the shortcoming 1206 * of assuming that input PNG data with no gamma information is linear - this 1207 * is unlikely to be correct unless the PNG files where generated locally. 1208 * Most of the time the output precision will be so low as to show 1209 * significant banding in dark areas of the image. 1210 * 1211 * png_set_expand_16(pp); 1212 * png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_DEFAULT_sRGB); 1213 * This is a somewhat more realistic Jim Blinn inspired approach. PNG files 1214 * are assumed to have the sRGB encoding if not marked with a gamma value and 1215 * the output is always 16 bits per component. This permits accurate scaling 1216 * and processing of the data. If you know that your input PNG files were 1217 * generated locally you might need to replace PNG_DEFAULT_sRGB with the 1218 * correct value for your system. 1219 * 1220 * png_set_alpha_mode(pp, PNG_ALPHA_OPTIMIZED, PNG_DEFAULT_sRGB); 1221 * If you just need to composite the PNG image onto an existing background 1222 * and if you control the code that does this you can use the optimization 1223 * setting. In this case you just copy completely opaque pixels to the 1224 * output. For pixels that are not completely transparent (you just skip 1225 * those) you do the composition math using png_composite or png_composite_16 1226 * below then encode the resultant 8-bit or 16-bit values to match the output 1227 * encoding. 1228 * 1229 * Other cases 1230 * If neither the PNG nor the standard linear encoding work for you because 1231 * of the software or hardware you use then you have a big problem. The PNG 1232 * case will probably result in halos around the image. The linear encoding 1233 * will probably result in a washed out, too bright, image (it's actually too 1234 * contrasty.) Try the ALPHA_OPTIMIZED mode above - this will probably 1235 * substantially reduce the halos. Alternatively try: 1236 * 1237 * png_set_alpha_mode(pp, PNG_ALPHA_BROKEN, PNG_DEFAULT_sRGB); 1238 * This option will also reduce the halos, but there will be slight dark 1239 * halos round the opaque parts of the image where the background is light. 1240 * In the OPTIMIZED mode the halos will be light halos where the background 1241 * is dark. Take your pick - the halos are unavoidable unless you can get 1242 * your hardware/software fixed! (The OPTIMIZED approach is slightly 1243 * faster.) 1244 * 1245 * When the default gamma of PNG files doesn't match the output gamma. 1246 * If you have PNG files with no gamma information png_set_alpha_mode allows 1247 * you to provide a default gamma, but it also sets the ouput gamma to the 1248 * matching value. If you know your PNG files have a gamma that doesn't 1249 * match the output you can take advantage of the fact that 1250 * png_set_alpha_mode always sets the output gamma but only sets the PNG 1251 * default if it is not already set: 1252 * 1253 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB); 1254 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC); 1255 * The first call sets both the default and the output gamma values, the 1256 * second call overrides the output gamma without changing the default. This 1257 * is easier than achieving the same effect with png_set_gamma. You must use 1258 * PNG_ALPHA_PNG for the first call - internal checking in png_set_alpha will 1259 * fire if more than one call to png_set_alpha_mode and png_set_background is 1260 * made in the same read operation, however multiple calls with PNG_ALPHA_PNG 1261 * are ignored. 1262 */ 1263 1264 #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED 1265 PNG_EXPORT(36, void, png_set_strip_alpha, (png_structrp png_ptr)); 1266 #endif 1267 1268 #if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \ 1269 defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED) 1270 PNG_EXPORT(37, void, png_set_swap_alpha, (png_structrp png_ptr)); 1271 #endif 1272 1273 #if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \ 1274 defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED) 1275 PNG_EXPORT(38, void, png_set_invert_alpha, (png_structrp png_ptr)); 1276 #endif 1277 1278 #if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED) 1279 /* Add a filler byte to 8-bit or 16-bit Gray or 24-bit or 48-bit RGB images. */ 1280 PNG_EXPORT(39, void, png_set_filler, (png_structrp png_ptr, png_uint_32 filler, 1281 int flags)); 1282 /* The values of the PNG_FILLER_ defines should NOT be changed */ 1283 # define PNG_FILLER_BEFORE 0 1284 # define PNG_FILLER_AFTER 1 1285 /* Add an alpha byte to 8-bit or 16-bit Gray or 24-bit or 48-bit RGB images. */ 1286 PNG_EXPORT(40, void, png_set_add_alpha, (png_structrp png_ptr, 1287 png_uint_32 filler, int flags)); 1288 #endif /* READ_FILLER || WRITE_FILLER */ 1289 1290 #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED) 1291 /* Swap bytes in 16-bit depth files. */ 1292 PNG_EXPORT(41, void, png_set_swap, (png_structrp png_ptr)); 1293 #endif 1294 1295 #if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED) 1296 /* Use 1 byte per pixel in 1, 2, or 4-bit depth files. */ 1297 PNG_EXPORT(42, void, png_set_packing, (png_structrp png_ptr)); 1298 #endif 1299 1300 #if defined(PNG_READ_PACKSWAP_SUPPORTED) || \ 1301 defined(PNG_WRITE_PACKSWAP_SUPPORTED) 1302 /* Swap packing order of pixels in bytes. */ 1303 PNG_EXPORT(43, void, png_set_packswap, (png_structrp png_ptr)); 1304 #endif 1305 1306 #if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED) 1307 /* Converts files to legal bit depths. */ 1308 PNG_EXPORT(44, void, png_set_shift, (png_structrp png_ptr, png_const_color_8p 1309 true_bits)); 1310 #endif 1311 1312 #if defined(PNG_READ_INTERLACING_SUPPORTED) || \ 1313 defined(PNG_WRITE_INTERLACING_SUPPORTED) 1314 /* Have the code handle the interlacing. Returns the number of passes. 1315 * MUST be called before png_read_update_info or png_start_read_image, 1316 * otherwise it will not have the desired effect. Note that it is still 1317 * necessary to call png_read_row or png_read_rows png_get_image_height 1318 * times for each pass. 1319 */ 1320 PNG_EXPORT(45, int, png_set_interlace_handling, (png_structrp png_ptr)); 1321 #endif 1322 1323 #if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED) 1324 /* Invert monochrome files */ 1325 PNG_EXPORT(46, void, png_set_invert_mono, (png_structrp png_ptr)); 1326 #endif 1327 1328 #ifdef PNG_READ_BACKGROUND_SUPPORTED 1329 /* Handle alpha and tRNS by replacing with a background color. Prior to 1330 * libpng-1.5.4 this API must not be called before the PNG file header has been 1331 * read. Doing so will result in unexpected behavior and possible warnings or 1332 * errors if the PNG file contains a bKGD chunk. 1333 */ 1334 PNG_FP_EXPORT(47, void, png_set_background, (png_structrp png_ptr, 1335 png_const_color_16p background_color, int background_gamma_code, 1336 int need_expand, double background_gamma)) 1337 PNG_FIXED_EXPORT(215, void, png_set_background_fixed, (png_structrp png_ptr, 1338 png_const_color_16p background_color, int background_gamma_code, 1339 int need_expand, png_fixed_point background_gamma)) 1340 #endif 1341 #ifdef PNG_READ_BACKGROUND_SUPPORTED 1342 # define PNG_BACKGROUND_GAMMA_UNKNOWN 0 1343 # define PNG_BACKGROUND_GAMMA_SCREEN 1 1344 # define PNG_BACKGROUND_GAMMA_FILE 2 1345 # define PNG_BACKGROUND_GAMMA_UNIQUE 3 1346 #endif 1347 1348 #ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED 1349 /* Scale a 16-bit depth file down to 8-bit, accurately. */ 1350 PNG_EXPORT(229, void, png_set_scale_16, (png_structrp png_ptr)); 1351 #endif 1352 1353 #ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED 1354 #define PNG_READ_16_TO_8_SUPPORTED /* Name prior to 1.5.4 */ 1355 /* Strip the second byte of information from a 16-bit depth file. */ 1356 PNG_EXPORT(48, void, png_set_strip_16, (png_structrp png_ptr)); 1357 #endif 1358 1359 #ifdef PNG_READ_QUANTIZE_SUPPORTED 1360 /* Turn on quantizing, and reduce the palette to the number of colors 1361 * available. 1362 */ 1363 PNG_EXPORT(49, void, png_set_quantize, (png_structrp png_ptr, 1364 png_colorp palette, int num_palette, int maximum_colors, 1365 png_const_uint_16p histogram, int full_quantize)); 1366 #endif 1367 1368 #ifdef PNG_READ_GAMMA_SUPPORTED 1369 /* The threshold on gamma processing is configurable but hard-wired into the 1370 * library. The following is the floating point variant. 1371 */ 1372 #define PNG_GAMMA_THRESHOLD (PNG_GAMMA_THRESHOLD_FIXED*.00001) 1373 1374 /* Handle gamma correction. Screen_gamma=(display_exponent). 1375 * NOTE: this API simply sets the screen and file gamma values. It will 1376 * therefore override the value for gamma in a PNG file if it is called after 1377 * the file header has been read - use with care - call before reading the PNG 1378 * file for best results! 1379 * 1380 * These routines accept the same gamma values as png_set_alpha_mode (described 1381 * above). The PNG_GAMMA_ defines and PNG_DEFAULT_sRGB can be passed to either 1382 * API (floating point or fixed.) Notice, however, that the 'file_gamma' value 1383 * is the inverse of a 'screen gamma' value. 1384 */ 1385 PNG_FP_EXPORT(50, void, png_set_gamma, (png_structrp png_ptr, 1386 double screen_gamma, double override_file_gamma)) 1387 PNG_FIXED_EXPORT(208, void, png_set_gamma_fixed, (png_structrp png_ptr, 1388 png_fixed_point screen_gamma, png_fixed_point override_file_gamma)) 1389 #endif 1390 1391 #ifdef PNG_WRITE_FLUSH_SUPPORTED 1392 /* Set how many lines between output flushes - 0 for no flushing */ 1393 PNG_EXPORT(51, void, png_set_flush, (png_structrp png_ptr, int nrows)); 1394 /* Flush the current PNG output buffer */ 1395 PNG_EXPORT(52, void, png_write_flush, (png_structrp png_ptr)); 1396 #endif 1397 1398 /* Optional update palette with requested transformations */ 1399 PNG_EXPORT(53, void, png_start_read_image, (png_structrp png_ptr)); 1400 1401 /* Optional call to update the users info structure */ 1402 PNG_EXPORT(54, void, png_read_update_info, (png_structrp png_ptr, 1403 png_inforp info_ptr)); 1404 1405 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED 1406 /* Read one or more rows of image data. */ 1407 PNG_EXPORT(55, void, png_read_rows, (png_structrp png_ptr, png_bytepp row, 1408 png_bytepp display_row, png_uint_32 num_rows)); 1409 #endif 1410 1411 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED 1412 /* Read a row of data. */ 1413 PNG_EXPORT(56, void, png_read_row, (png_structrp png_ptr, png_bytep row, 1414 png_bytep display_row)); 1415 #endif 1416 1417 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED 1418 /* Read the whole image into memory at once. */ 1419 PNG_EXPORT(57, void, png_read_image, (png_structrp png_ptr, png_bytepp image)); 1420 #endif 1421 1422 /* Write a row of image data */ 1423 PNG_EXPORT(58, void, png_write_row, (png_structrp png_ptr, 1424 png_const_bytep row)); 1425 1426 /* Write a few rows of image data: (*row) is not written; however, the type 1427 * is declared as writeable to maintain compatibility with previous versions 1428 * of libpng and to allow the 'display_row' array from read_rows to be passed 1429 * unchanged to write_rows. 1430 */ 1431 PNG_EXPORT(59, void, png_write_rows, (png_structrp png_ptr, png_bytepp row, 1432 png_uint_32 num_rows)); 1433 1434 /* Write the image data */ 1435 PNG_EXPORT(60, void, png_write_image, (png_structrp png_ptr, png_bytepp image)); 1436 1437 /* Write the end of the PNG file. */ 1438 PNG_EXPORT(61, void, png_write_end, (png_structrp png_ptr, 1439 png_inforp info_ptr)); 1440 1441 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED 1442 /* Read the end of the PNG file. */ 1443 PNG_EXPORT(62, void, png_read_end, (png_structrp png_ptr, png_inforp info_ptr)); 1444 #endif 1445 1446 /* Free any memory associated with the png_info_struct */ 1447 PNG_EXPORT(63, void, png_destroy_info_struct, (png_const_structrp png_ptr, 1448 png_infopp info_ptr_ptr)); 1449 1450 /* Free any memory associated with the png_struct and the png_info_structs */ 1451 PNG_EXPORT(64, void, png_destroy_read_struct, (png_structpp png_ptr_ptr, 1452 png_infopp info_ptr_ptr, png_infopp end_info_ptr_ptr)); 1453 1454 /* Free any memory associated with the png_struct and the png_info_structs */ 1455 PNG_EXPORT(65, void, png_destroy_write_struct, (png_structpp png_ptr_ptr, 1456 png_infopp info_ptr_ptr)); 1457 1458 /* Set the libpng method of handling chunk CRC errors */ 1459 PNG_EXPORT(66, void, png_set_crc_action, (png_structrp png_ptr, int crit_action, 1460 int ancil_action)); 1461 1462 /* Values for png_set_crc_action() say how to handle CRC errors in 1463 * ancillary and critical chunks, and whether to use the data contained 1464 * therein. Note that it is impossible to "discard" data in a critical 1465 * chunk. For versions prior to 0.90, the action was always error/quit, 1466 * whereas in version 0.90 and later, the action for CRC errors in ancillary 1467 * chunks is warn/discard. These values should NOT be changed. 1468 * 1469 * value action:critical action:ancillary 1470 */ 1471 #define PNG_CRC_DEFAULT 0 /* error/quit warn/discard data */ 1472 #define PNG_CRC_ERROR_QUIT 1 /* error/quit error/quit */ 1473 #define PNG_CRC_WARN_DISCARD 2 /* (INVALID) warn/discard data */ 1474 #define PNG_CRC_WARN_USE 3 /* warn/use data warn/use data */ 1475 #define PNG_CRC_QUIET_USE 4 /* quiet/use data quiet/use data */ 1476 #define PNG_CRC_NO_CHANGE 5 /* use current value use current value */ 1477 1478 #ifdef PNG_WRITE_SUPPORTED 1479 /* These functions give the user control over the scan-line filtering in 1480 * libpng and the compression methods used by zlib. These functions are 1481 * mainly useful for testing, as the defaults should work with most users. 1482 * Those users who are tight on memory or want faster performance at the 1483 * expense of compression can modify them. See the compression library 1484 * header file (zlib.h) for an explination of the compression functions. 1485 */ 1486 1487 /* Set the filtering method(s) used by libpng. Currently, the only valid 1488 * value for "method" is 0. 1489 */ 1490 PNG_EXPORT(67, void, png_set_filter, (png_structrp png_ptr, int method, 1491 int filters)); 1492 #endif /* WRITE */ 1493 1494 /* Flags for png_set_filter() to say which filters to use. The flags 1495 * are chosen so that they don't conflict with real filter types 1496 * below, in case they are supplied instead of the #defined constants. 1497 * These values should NOT be changed. 1498 */ 1499 #define PNG_NO_FILTERS 0x00 1500 #define PNG_FILTER_NONE 0x08 1501 #define PNG_FILTER_SUB 0x10 1502 #define PNG_FILTER_UP 0x20 1503 #define PNG_FILTER_AVG 0x40 1504 #define PNG_FILTER_PAETH 0x80 1505 #define PNG_FAST_FILTERS (PNG_FILTER_NONE | PNG_FILTER_SUB | PNG_FILTER_UP) 1506 #define PNG_ALL_FILTERS (PNG_FAST_FILTERS | PNG_FILTER_AVG | PNG_FILTER_PAETH) 1507 1508 /* Filter values (not flags) - used in pngwrite.c, pngwutil.c for now. 1509 * These defines should NOT be changed. 1510 */ 1511 #define PNG_FILTER_VALUE_NONE 0 1512 #define PNG_FILTER_VALUE_SUB 1 1513 #define PNG_FILTER_VALUE_UP 2 1514 #define PNG_FILTER_VALUE_AVG 3 1515 #define PNG_FILTER_VALUE_PAETH 4 1516 #define PNG_FILTER_VALUE_LAST 5 1517 1518 #ifdef PNG_WRITE_SUPPORTED 1519 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* DEPRECATED */ 1520 PNG_FP_EXPORT(68, void, png_set_filter_heuristics, (png_structrp png_ptr, 1521 int heuristic_method, int num_weights, png_const_doublep filter_weights, 1522 png_const_doublep filter_costs)) 1523 PNG_FIXED_EXPORT(209, void, png_set_filter_heuristics_fixed, 1524 (png_structrp png_ptr, int heuristic_method, int num_weights, 1525 png_const_fixed_point_p filter_weights, 1526 png_const_fixed_point_p filter_costs)) 1527 #endif /* WRITE_WEIGHTED_FILTER */ 1528 1529 /* The following are no longer used and will be removed from libpng-1.7: */ 1530 #define PNG_FILTER_HEURISTIC_DEFAULT 0 /* Currently "UNWEIGHTED" */ 1531 #define PNG_FILTER_HEURISTIC_UNWEIGHTED 1 /* Used by libpng < 0.95 */ 1532 #define PNG_FILTER_HEURISTIC_WEIGHTED 2 /* Experimental feature */ 1533 #define PNG_FILTER_HEURISTIC_LAST 3 /* Not a valid value */ 1534 1535 /* Set the library compression level. Currently, valid values range from 1536 * 0 - 9, corresponding directly to the zlib compression levels 0 - 9 1537 * (0 - no compression, 9 - "maximal" compression). Note that tests have 1538 * shown that zlib compression levels 3-6 usually perform as well as level 9 1539 * for PNG images, and do considerably fewer caclulations. In the future, 1540 * these values may not correspond directly to the zlib compression levels. 1541 */ 1542 #ifdef PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED 1543 PNG_EXPORT(69, void, png_set_compression_level, (png_structrp png_ptr, 1544 int level)); 1545 1546 PNG_EXPORT(70, void, png_set_compression_mem_level, (png_structrp png_ptr, 1547 int mem_level)); 1548 1549 PNG_EXPORT(71, void, png_set_compression_strategy, (png_structrp png_ptr, 1550 int strategy)); 1551 1552 /* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a 1553 * smaller value of window_bits if it can do so safely. 1554 */ 1555 PNG_EXPORT(72, void, png_set_compression_window_bits, (png_structrp png_ptr, 1556 int window_bits)); 1557 1558 PNG_EXPORT(73, void, png_set_compression_method, (png_structrp png_ptr, 1559 int method)); 1560 #endif /* WRITE_CUSTOMIZE_COMPRESSION */ 1561 1562 #ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED 1563 /* Also set zlib parameters for compressing non-IDAT chunks */ 1564 PNG_EXPORT(222, void, png_set_text_compression_level, (png_structrp png_ptr, 1565 int level)); 1566 1567 PNG_EXPORT(223, void, png_set_text_compression_mem_level, (png_structrp png_ptr, 1568 int mem_level)); 1569 1570 PNG_EXPORT(224, void, png_set_text_compression_strategy, (png_structrp png_ptr, 1571 int strategy)); 1572 1573 /* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a 1574 * smaller value of window_bits if it can do so safely. 1575 */ 1576 PNG_EXPORT(225, void, png_set_text_compression_window_bits, 1577 (png_structrp png_ptr, int window_bits)); 1578 1579 PNG_EXPORT(226, void, png_set_text_compression_method, (png_structrp png_ptr, 1580 int method)); 1581 #endif /* WRITE_CUSTOMIZE_ZTXT_COMPRESSION */ 1582 #endif /* WRITE */ 1583 1584 /* These next functions are called for input/output, memory, and error 1585 * handling. They are in the file pngrio.c, pngwio.c, and pngerror.c, 1586 * and call standard C I/O routines such as fread(), fwrite(), and 1587 * fprintf(). These functions can be made to use other I/O routines 1588 * at run time for those applications that need to handle I/O in a 1589 * different manner by calling png_set_???_fn(). See libpng-manual.txt for 1590 * more information. 1591 */ 1592 1593 #ifdef PNG_STDIO_SUPPORTED 1594 /* Initialize the input/output for the PNG file to the default functions. */ 1595 PNG_EXPORT(74, void, png_init_io, (png_structrp png_ptr, png_FILE_p fp)); 1596 #endif 1597 1598 /* Replace the (error and abort), and warning functions with user 1599 * supplied functions. If no messages are to be printed you must still 1600 * write and use replacement functions. The replacement error_fn should 1601 * still do a longjmp to the last setjmp location if you are using this 1602 * method of error handling. If error_fn or warning_fn is NULL, the 1603 * default function will be used. 1604 */ 1605 1606 PNG_EXPORT(75, void, png_set_error_fn, (png_structrp png_ptr, 1607 png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warning_fn)); 1608 1609 /* Return the user pointer associated with the error functions */ 1610 PNG_EXPORT(76, png_voidp, png_get_error_ptr, (png_const_structrp png_ptr)); 1611 1612 /* Replace the default data output functions with a user supplied one(s). 1613 * If buffered output is not used, then output_flush_fn can be set to NULL. 1614 * If PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile time 1615 * output_flush_fn will be ignored (and thus can be NULL). 1616 * It is probably a mistake to use NULL for output_flush_fn if 1617 * write_data_fn is not also NULL unless you have built libpng with 1618 * PNG_WRITE_FLUSH_SUPPORTED undefined, because in this case libpng's 1619 * default flush function, which uses the standard *FILE structure, will 1620 * be used. 1621 */ 1622 PNG_EXPORT(77, void, png_set_write_fn, (png_structrp png_ptr, png_voidp io_ptr, 1623 png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn)); 1624 1625 /* Replace the default data input function with a user supplied one. */ 1626 PNG_EXPORT(78, void, png_set_read_fn, (png_structrp png_ptr, png_voidp io_ptr, 1627 png_rw_ptr read_data_fn)); 1628 1629 /* Return the user pointer associated with the I/O functions */ 1630 PNG_EXPORT(79, png_voidp, png_get_io_ptr, (png_const_structrp png_ptr)); 1631 1632 PNG_EXPORT(80, void, png_set_read_status_fn, (png_structrp png_ptr, 1633 png_read_status_ptr read_row_fn)); 1634 1635 PNG_EXPORT(81, void, png_set_write_status_fn, (png_structrp png_ptr, 1636 png_write_status_ptr write_row_fn)); 1637 1638 #ifdef PNG_USER_MEM_SUPPORTED 1639 /* Replace the default memory allocation functions with user supplied one(s). */ 1640 PNG_EXPORT(82, void, png_set_mem_fn, (png_structrp png_ptr, png_voidp mem_ptr, 1641 png_malloc_ptr malloc_fn, png_free_ptr free_fn)); 1642 /* Return the user pointer associated with the memory functions */ 1643 PNG_EXPORT(83, png_voidp, png_get_mem_ptr, (png_const_structrp png_ptr)); 1644 #endif 1645 1646 #ifdef PNG_READ_USER_TRANSFORM_SUPPORTED 1647 PNG_EXPORT(84, void, png_set_read_user_transform_fn, (png_structrp png_ptr, 1648 png_user_transform_ptr read_user_transform_fn)); 1649 #endif 1650 1651 #ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED 1652 PNG_EXPORT(85, void, png_set_write_user_transform_fn, (png_structrp png_ptr, 1653 png_user_transform_ptr write_user_transform_fn)); 1654 #endif 1655 1656 #ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED 1657 PNG_EXPORT(86, void, png_set_user_transform_info, (png_structrp png_ptr, 1658 png_voidp user_transform_ptr, int user_transform_depth, 1659 int user_transform_channels)); 1660 /* Return the user pointer associated with the user transform functions */ 1661 PNG_EXPORT(87, png_voidp, png_get_user_transform_ptr, 1662 (png_const_structrp png_ptr)); 1663 #endif 1664 1665 #ifdef PNG_USER_TRANSFORM_INFO_SUPPORTED 1666 /* Return information about the row currently being processed. Note that these 1667 * APIs do not fail but will return unexpected results if called outside a user 1668 * transform callback. Also note that when transforming an interlaced image the 1669 * row number is the row number within the sub-image of the interlace pass, so 1670 * the value will increase to the height of the sub-image (not the full image) 1671 * then reset to 0 for the next pass. 1672 * 1673 * Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to 1674 * find the output pixel (x,y) given an interlaced sub-image pixel 1675 * (row,col,pass). (See below for these macros.) 1676 */ 1677 PNG_EXPORT(217, png_uint_32, png_get_current_row_number, (png_const_structrp)); 1678 PNG_EXPORT(218, png_byte, png_get_current_pass_number, (png_const_structrp)); 1679 #endif 1680 1681 #ifdef PNG_READ_USER_CHUNKS_SUPPORTED 1682 /* This callback is called only for *unknown* chunks. If 1683 * PNG_HANDLE_AS_UNKNOWN_SUPPORTED is set then it is possible to set known 1684 * chunks to be treated as unknown, however in this case the callback must do 1685 * any processing required by the chunk (e.g. by calling the appropriate 1686 * png_set_ APIs.) 1687 * 1688 * There is no write support - on write, by default, all the chunks in the 1689 * 'unknown' list are written in the specified position. 1690 * 1691 * The integer return from the callback function is interpreted thus: 1692 * 1693 * negative: An error occurred; png_chunk_error will be called. 1694 * zero: The chunk was not handled, the chunk will be saved. A critical 1695 * chunk will cause an error at this point unless it is to be saved. 1696 * positive: The chunk was handled, libpng will ignore/discard it. 1697 * 1698 * See "INTERACTION WTIH USER CHUNK CALLBACKS" below for important notes about 1699 * how this behavior will change in libpng 1.7 1700 */ 1701 PNG_EXPORT(88, void, png_set_read_user_chunk_fn, (png_structrp png_ptr, 1702 png_voidp user_chunk_ptr, png_user_chunk_ptr read_user_chunk_fn)); 1703 #endif 1704 1705 #ifdef PNG_USER_CHUNKS_SUPPORTED 1706 PNG_EXPORT(89, png_voidp, png_get_user_chunk_ptr, (png_const_structrp png_ptr)); 1707 #endif 1708 1709 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED 1710 /* Sets the function callbacks for the push reader, and a pointer to a 1711 * user-defined structure available to the callback functions. 1712 */ 1713 PNG_EXPORT(90, void, png_set_progressive_read_fn, (png_structrp png_ptr, 1714 png_voidp progressive_ptr, png_progressive_info_ptr info_fn, 1715 png_progressive_row_ptr row_fn, png_progressive_end_ptr end_fn)); 1716 1717 /* Returns the user pointer associated with the push read functions */ 1718 PNG_EXPORT(91, png_voidp, png_get_progressive_ptr, 1719 (png_const_structrp png_ptr)); 1720 1721 /* Function to be called when data becomes available */ 1722 PNG_EXPORT(92, void, png_process_data, (png_structrp png_ptr, 1723 png_inforp info_ptr, png_bytep buffer, png_size_t buffer_size)); 1724 1725 /* A function which may be called *only* within png_process_data to stop the 1726 * processing of any more data. The function returns the number of bytes 1727 * remaining, excluding any that libpng has cached internally. A subsequent 1728 * call to png_process_data must supply these bytes again. If the argument 1729 * 'save' is set to true the routine will first save all the pending data and 1730 * will always return 0. 1731 */ 1732 PNG_EXPORT(219, png_size_t, png_process_data_pause, (png_structrp, int save)); 1733 1734 /* A function which may be called *only* outside (after) a call to 1735 * png_process_data. It returns the number of bytes of data to skip in the 1736 * input. Normally it will return 0, but if it returns a non-zero value the 1737 * application must skip than number of bytes of input data and pass the 1738 * following data to the next call to png_process_data. 1739 */ 1740 PNG_EXPORT(220, png_uint_32, png_process_data_skip, (png_structrp)); 1741 1742 /* Function that combines rows. 'new_row' is a flag that should come from 1743 * the callback and be non-NULL if anything needs to be done; the library 1744 * stores its own version of the new data internally and ignores the passed 1745 * in value. 1746 */ 1747 PNG_EXPORT(93, void, png_progressive_combine_row, (png_const_structrp png_ptr, 1748 png_bytep old_row, png_const_bytep new_row)); 1749 #endif /* PROGRESSIVE_READ */ 1750 1751 PNG_EXPORTA(94, png_voidp, png_malloc, (png_const_structrp png_ptr, 1752 png_alloc_size_t size), PNG_ALLOCATED); 1753 /* Added at libpng version 1.4.0 */ 1754 PNG_EXPORTA(95, png_voidp, png_calloc, (png_const_structrp png_ptr, 1755 png_alloc_size_t size), PNG_ALLOCATED); 1756 1757 /* Added at libpng version 1.2.4 */ 1758 PNG_EXPORTA(96, png_voidp, png_malloc_warn, (png_const_structrp png_ptr, 1759 png_alloc_size_t size), PNG_ALLOCATED); 1760 1761 /* Frees a pointer allocated by png_malloc() */ 1762 PNG_EXPORT(97, void, png_free, (png_const_structrp png_ptr, png_voidp ptr)); 1763 1764 /* Free data that was allocated internally */ 1765 PNG_EXPORT(98, void, png_free_data, (png_const_structrp png_ptr, 1766 png_inforp info_ptr, png_uint_32 free_me, int num)); 1767 1768 /* Reassign responsibility for freeing existing data, whether allocated 1769 * by libpng or by the application; this works on the png_info structure passed 1770 * in, it does not change the state for other png_info structures. 1771 * 1772 * It is unlikely that this function works correctly as of 1.6.0 and using it 1773 * may result either in memory leaks or double free of allocated data. 1774 */ 1775 PNG_EXPORT(99, void, png_data_freer, (png_const_structrp png_ptr, 1776 png_inforp info_ptr, int freer, png_uint_32 mask)); 1777 1778 /* Assignments for png_data_freer */ 1779 #define PNG_DESTROY_WILL_FREE_DATA 1 1780 #define PNG_SET_WILL_FREE_DATA 1 1781 #define PNG_USER_WILL_FREE_DATA 2 1782 /* Flags for png_ptr->free_me and info_ptr->free_me */ 1783 #define PNG_FREE_HIST 0x0008U 1784 #define PNG_FREE_ICCP 0x0010U 1785 #define PNG_FREE_SPLT 0x0020U 1786 #define PNG_FREE_ROWS 0x0040U 1787 #define PNG_FREE_PCAL 0x0080U 1788 #define PNG_FREE_SCAL 0x0100U 1789 #ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED 1790 # define PNG_FREE_UNKN 0x0200U 1791 #endif 1792 /* PNG_FREE_LIST 0x0400U removed in 1.6.0 because it is ignored */ 1793 #define PNG_FREE_PLTE 0x1000U 1794 #define PNG_FREE_TRNS 0x2000U 1795 #define PNG_FREE_TEXT 0x4000U 1796 #define PNG_FREE_ALL 0x7fffU 1797 #define PNG_FREE_MUL 0x4220U /* PNG_FREE_SPLT|PNG_FREE_TEXT|PNG_FREE_UNKN */ 1798 1799 #ifdef PNG_USER_MEM_SUPPORTED 1800 PNG_EXPORTA(100, png_voidp, png_malloc_default, (png_const_structrp png_ptr, 1801 png_alloc_size_t size), PNG_ALLOCATED PNG_DEPRECATED); 1802 PNG_EXPORTA(101, void, png_free_default, (png_const_structrp png_ptr, 1803 png_voidp ptr), PNG_DEPRECATED); 1804 #endif 1805 1806 #ifdef PNG_ERROR_TEXT_SUPPORTED 1807 /* Fatal error in PNG image of libpng - can't continue */ 1808 PNG_EXPORTA(102, void, png_error, (png_const_structrp png_ptr, 1809 png_const_charp error_message), PNG_NORETURN); 1810 1811 /* The same, but the chunk name is prepended to the error string. */ 1812 PNG_EXPORTA(103, void, png_chunk_error, (png_const_structrp png_ptr, 1813 png_const_charp error_message), PNG_NORETURN); 1814 1815 #else 1816 /* Fatal error in PNG image of libpng - can't continue */ 1817 PNG_EXPORTA(104, void, png_err, (png_const_structrp png_ptr), PNG_NORETURN); 1818 # define png_error(s1,s2) png_err(s1) 1819 # define png_chunk_error(s1,s2) png_err(s1) 1820 #endif 1821 1822 #ifdef PNG_WARNINGS_SUPPORTED 1823 /* Non-fatal error in libpng. Can continue, but may have a problem. */ 1824 PNG_EXPORT(105, void, png_warning, (png_const_structrp png_ptr, 1825 png_const_charp warning_message)); 1826 1827 /* Non-fatal error in libpng, chunk name is prepended to message. */ 1828 PNG_EXPORT(106, void, png_chunk_warning, (png_const_structrp png_ptr, 1829 png_const_charp warning_message)); 1830 #else 1831 # define png_warning(s1,s2) ((void)(s1)) 1832 # define png_chunk_warning(s1,s2) ((void)(s1)) 1833 #endif 1834 1835 #ifdef PNG_BENIGN_ERRORS_SUPPORTED 1836 /* Benign error in libpng. Can continue, but may have a problem. 1837 * User can choose whether to handle as a fatal error or as a warning. */ 1838 PNG_EXPORT(107, void, png_benign_error, (png_const_structrp png_ptr, 1839 png_const_charp warning_message)); 1840 1841 #ifdef PNG_READ_SUPPORTED 1842 /* Same, chunk name is prepended to message (only during read) */ 1843 PNG_EXPORT(108, void, png_chunk_benign_error, (png_const_structrp png_ptr, 1844 png_const_charp warning_message)); 1845 #endif 1846 1847 PNG_EXPORT(109, void, png_set_benign_errors, 1848 (png_structrp png_ptr, int allowed)); 1849 #else 1850 # ifdef PNG_ALLOW_BENIGN_ERRORS 1851 # define png_benign_error png_warning 1852 # define png_chunk_benign_error png_chunk_warning 1853 # else 1854 # define png_benign_error png_error 1855 # define png_chunk_benign_error png_chunk_error 1856 # endif 1857 #endif 1858 1859 /* The png_set_<chunk> functions are for storing values in the png_info_struct. 1860 * Similarly, the png_get_<chunk> calls are used to read values from the 1861 * png_info_struct, either storing the parameters in the passed variables, or 1862 * setting pointers into the png_info_struct where the data is stored. The 1863 * png_get_<chunk> functions return a non-zero value if the data was available 1864 * in info_ptr, or return zero and do not change any of the parameters if the 1865 * data was not available. 1866 * 1867 * These functions should be used instead of directly accessing png_info 1868 * to avoid problems with future changes in the size and internal layout of 1869 * png_info_struct. 1870 */ 1871 /* Returns "flag" if chunk data is valid in info_ptr. */ 1872 PNG_EXPORT(110, png_uint_32, png_get_valid, (png_const_structrp png_ptr, 1873 png_const_inforp info_ptr, png_uint_32 flag)); 1874 1875 /* Returns number of bytes needed to hold a transformed row. */ 1876 PNG_EXPORT(111, png_size_t, png_get_rowbytes, (png_const_structrp png_ptr, 1877 png_const_inforp info_ptr)); 1878 1879 #ifdef PNG_INFO_IMAGE_SUPPORTED 1880 /* Returns row_pointers, which is an array of pointers to scanlines that was 1881 * returned from png_read_png(). 1882 */ 1883 PNG_EXPORT(112, png_bytepp, png_get_rows, (png_const_structrp png_ptr, 1884 png_const_inforp info_ptr)); 1885 1886 /* Set row_pointers, which is an array of pointers to scanlines for use 1887 * by png_write_png(). 1888 */ 1889 PNG_EXPORT(113, void, png_set_rows, (png_const_structrp png_ptr, 1890 png_inforp info_ptr, png_bytepp row_pointers)); 1891 #endif 1892 1893 /* Returns number of color channels in image. */ 1894 PNG_EXPORT(114, png_byte, png_get_channels, (png_const_structrp png_ptr, 1895 png_const_inforp info_ptr)); 1896 1897 #ifdef PNG_EASY_ACCESS_SUPPORTED 1898 /* Returns image width in pixels. */ 1899 PNG_EXPORT(115, png_uint_32, png_get_image_width, (png_const_structrp png_ptr, 1900 png_const_inforp info_ptr)); 1901 1902 /* Returns image height in pixels. */ 1903 PNG_EXPORT(116, png_uint_32, png_get_image_height, (png_const_structrp png_ptr, 1904 png_const_inforp info_ptr)); 1905 1906 /* Returns image bit_depth. */ 1907 PNG_EXPORT(117, png_byte, png_get_bit_depth, (png_const_structrp png_ptr, 1908 png_const_inforp info_ptr)); 1909 1910 /* Returns image color_type. */ 1911 PNG_EXPORT(118, png_byte, png_get_color_type, (png_const_structrp png_ptr, 1912 png_const_inforp info_ptr)); 1913 1914 /* Returns image filter_type. */ 1915 PNG_EXPORT(119, png_byte, png_get_filter_type, (png_const_structrp png_ptr, 1916 png_const_inforp info_ptr)); 1917 1918 /* Returns image interlace_type. */ 1919 PNG_EXPORT(120, png_byte, png_get_interlace_type, (png_const_structrp png_ptr, 1920 png_const_inforp info_ptr)); 1921 1922 /* Returns image compression_type. */ 1923 PNG_EXPORT(121, png_byte, png_get_compression_type, (png_const_structrp png_ptr, 1924 png_const_inforp info_ptr)); 1925 1926 /* Returns image resolution in pixels per meter, from pHYs chunk data. */ 1927 PNG_EXPORT(122, png_uint_32, png_get_pixels_per_meter, 1928 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 1929 PNG_EXPORT(123, png_uint_32, png_get_x_pixels_per_meter, 1930 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 1931 PNG_EXPORT(124, png_uint_32, png_get_y_pixels_per_meter, 1932 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 1933 1934 /* Returns pixel aspect ratio, computed from pHYs chunk data. */ 1935 PNG_FP_EXPORT(125, float, png_get_pixel_aspect_ratio, 1936 (png_const_structrp png_ptr, png_const_inforp info_ptr)) 1937 PNG_FIXED_EXPORT(210, png_fixed_point, png_get_pixel_aspect_ratio_fixed, 1938 (png_const_structrp png_ptr, png_const_inforp info_ptr)) 1939 1940 /* Returns image x, y offset in pixels or microns, from oFFs chunk data. */ 1941 PNG_EXPORT(126, png_int_32, png_get_x_offset_pixels, 1942 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 1943 PNG_EXPORT(127, png_int_32, png_get_y_offset_pixels, 1944 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 1945 PNG_EXPORT(128, png_int_32, png_get_x_offset_microns, 1946 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 1947 PNG_EXPORT(129, png_int_32, png_get_y_offset_microns, 1948 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 1949 1950 #endif /* EASY_ACCESS */ 1951 1952 #ifdef PNG_READ_SUPPORTED 1953 /* Returns pointer to signature string read from PNG header */ 1954 PNG_EXPORT(130, png_const_bytep, png_get_signature, (png_const_structrp png_ptr, 1955 png_const_inforp info_ptr)); 1956 #endif 1957 1958 #ifdef PNG_bKGD_SUPPORTED 1959 PNG_EXPORT(131, png_uint_32, png_get_bKGD, (png_const_structrp png_ptr, 1960 png_inforp info_ptr, png_color_16p *background)); 1961 #endif 1962 1963 #ifdef PNG_bKGD_SUPPORTED 1964 PNG_EXPORT(132, void, png_set_bKGD, (png_const_structrp png_ptr, 1965 png_inforp info_ptr, png_const_color_16p background)); 1966 #endif 1967 1968 #ifdef PNG_cHRM_SUPPORTED 1969 PNG_FP_EXPORT(133, png_uint_32, png_get_cHRM, (png_const_structrp png_ptr, 1970 png_const_inforp info_ptr, double *white_x, double *white_y, double *red_x, 1971 double *red_y, double *green_x, double *green_y, double *blue_x, 1972 double *blue_y)) 1973 PNG_FP_EXPORT(230, png_uint_32, png_get_cHRM_XYZ, (png_const_structrp png_ptr, 1974 png_const_inforp info_ptr, double *red_X, double *red_Y, double *red_Z, 1975 double *green_X, double *green_Y, double *green_Z, double *blue_X, 1976 double *blue_Y, double *blue_Z)) 1977 PNG_FIXED_EXPORT(134, png_uint_32, png_get_cHRM_fixed, 1978 (png_const_structrp png_ptr, png_const_inforp info_ptr, 1979 png_fixed_point *int_white_x, png_fixed_point *int_white_y, 1980 png_fixed_point *int_red_x, png_fixed_point *int_red_y, 1981 png_fixed_point *int_green_x, png_fixed_point *int_green_y, 1982 png_fixed_point *int_blue_x, png_fixed_point *int_blue_y)) 1983 PNG_FIXED_EXPORT(231, png_uint_32, png_get_cHRM_XYZ_fixed, 1984 (png_const_structrp png_ptr, png_const_inforp info_ptr, 1985 png_fixed_point *int_red_X, png_fixed_point *int_red_Y, 1986 png_fixed_point *int_red_Z, png_fixed_point *int_green_X, 1987 png_fixed_point *int_green_Y, png_fixed_point *int_green_Z, 1988 png_fixed_point *int_blue_X, png_fixed_point *int_blue_Y, 1989 png_fixed_point *int_blue_Z)) 1990 #endif 1991 1992 #ifdef PNG_cHRM_SUPPORTED 1993 PNG_FP_EXPORT(135, void, png_set_cHRM, (png_const_structrp png_ptr, 1994 png_inforp info_ptr, 1995 double white_x, double white_y, double red_x, double red_y, double green_x, 1996 double green_y, double blue_x, double blue_y)) 1997 PNG_FP_EXPORT(232, void, png_set_cHRM_XYZ, (png_const_structrp png_ptr, 1998 png_inforp info_ptr, double red_X, double red_Y, double red_Z, 1999 double green_X, double green_Y, double green_Z, double blue_X, 2000 double blue_Y, double blue_Z)) 2001 PNG_FIXED_EXPORT(136, void, png_set_cHRM_fixed, (png_const_structrp png_ptr, 2002 png_inforp info_ptr, png_fixed_point int_white_x, 2003 png_fixed_point int_white_y, png_fixed_point int_red_x, 2004 png_fixed_point int_red_y, png_fixed_point int_green_x, 2005 png_fixed_point int_green_y, png_fixed_point int_blue_x, 2006 png_fixed_point int_blue_y)) 2007 PNG_FIXED_EXPORT(233, void, png_set_cHRM_XYZ_fixed, (png_const_structrp png_ptr, 2008 png_inforp info_ptr, png_fixed_point int_red_X, png_fixed_point int_red_Y, 2009 png_fixed_point int_red_Z, png_fixed_point int_green_X, 2010 png_fixed_point int_green_Y, png_fixed_point int_green_Z, 2011 png_fixed_point int_blue_X, png_fixed_point int_blue_Y, 2012 png_fixed_point int_blue_Z)) 2013 #endif 2014 2015 #ifdef PNG_gAMA_SUPPORTED 2016 PNG_FP_EXPORT(137, png_uint_32, png_get_gAMA, (png_const_structrp png_ptr, 2017 png_const_inforp info_ptr, double *file_gamma)) 2018 PNG_FIXED_EXPORT(138, png_uint_32, png_get_gAMA_fixed, 2019 (png_const_structrp png_ptr, png_const_inforp info_ptr, 2020 png_fixed_point *int_file_gamma)) 2021 #endif 2022 2023 #ifdef PNG_gAMA_SUPPORTED 2024 PNG_FP_EXPORT(139, void, png_set_gAMA, (png_const_structrp png_ptr, 2025 png_inforp info_ptr, double file_gamma)) 2026 PNG_FIXED_EXPORT(140, void, png_set_gAMA_fixed, (png_const_structrp png_ptr, 2027 png_inforp info_ptr, png_fixed_point int_file_gamma)) 2028 #endif 2029 2030 #ifdef PNG_hIST_SUPPORTED 2031 PNG_EXPORT(141, png_uint_32, png_get_hIST, (png_const_structrp png_ptr, 2032 png_inforp info_ptr, png_uint_16p *hist)); 2033 #endif 2034 2035 #ifdef PNG_hIST_SUPPORTED 2036 PNG_EXPORT(142, void, png_set_hIST, (png_const_structrp png_ptr, 2037 png_inforp info_ptr, png_const_uint_16p hist)); 2038 #endif 2039 2040 PNG_EXPORT(143, png_uint_32, png_get_IHDR, (png_const_structrp png_ptr, 2041 png_const_inforp info_ptr, png_uint_32 *width, png_uint_32 *height, 2042 int *bit_depth, int *color_type, int *interlace_method, 2043 int *compression_method, int *filter_method)); 2044 2045 PNG_EXPORT(144, void, png_set_IHDR, (png_const_structrp png_ptr, 2046 png_inforp info_ptr, png_uint_32 width, png_uint_32 height, int bit_depth, 2047 int color_type, int interlace_method, int compression_method, 2048 int filter_method)); 2049 2050 #ifdef PNG_oFFs_SUPPORTED 2051 PNG_EXPORT(145, png_uint_32, png_get_oFFs, (png_const_structrp png_ptr, 2052 png_const_inforp info_ptr, png_int_32 *offset_x, png_int_32 *offset_y, 2053 int *unit_type)); 2054 #endif 2055 2056 #ifdef PNG_oFFs_SUPPORTED 2057 PNG_EXPORT(146, void, png_set_oFFs, (png_const_structrp png_ptr, 2058 png_inforp info_ptr, png_int_32 offset_x, png_int_32 offset_y, 2059 int unit_type)); 2060 #endif 2061 2062 #ifdef PNG_pCAL_SUPPORTED 2063 PNG_EXPORT(147, png_uint_32, png_get_pCAL, (png_const_structrp png_ptr, 2064 png_inforp info_ptr, png_charp *purpose, png_int_32 *X0, 2065 png_int_32 *X1, int *type, int *nparams, png_charp *units, 2066 png_charpp *params)); 2067 #endif 2068 2069 #ifdef PNG_pCAL_SUPPORTED 2070 PNG_EXPORT(148, void, png_set_pCAL, (png_const_structrp png_ptr, 2071 png_inforp info_ptr, png_const_charp purpose, png_int_32 X0, png_int_32 X1, 2072 int type, int nparams, png_const_charp units, png_charpp params)); 2073 #endif 2074 2075 #ifdef PNG_pHYs_SUPPORTED 2076 PNG_EXPORT(149, png_uint_32, png_get_pHYs, (png_const_structrp png_ptr, 2077 png_const_inforp info_ptr, png_uint_32 *res_x, png_uint_32 *res_y, 2078 int *unit_type)); 2079 #endif 2080 2081 #ifdef PNG_pHYs_SUPPORTED 2082 PNG_EXPORT(150, void, png_set_pHYs, (png_const_structrp png_ptr, 2083 png_inforp info_ptr, png_uint_32 res_x, png_uint_32 res_y, int unit_type)); 2084 #endif 2085 2086 PNG_EXPORT(151, png_uint_32, png_get_PLTE, (png_const_structrp png_ptr, 2087 png_inforp info_ptr, png_colorp *palette, int *num_palette)); 2088 2089 PNG_EXPORT(152, void, png_set_PLTE, (png_structrp png_ptr, 2090 png_inforp info_ptr, png_const_colorp palette, int num_palette)); 2091 2092 #ifdef PNG_sBIT_SUPPORTED 2093 PNG_EXPORT(153, png_uint_32, png_get_sBIT, (png_const_structrp png_ptr, 2094 png_inforp info_ptr, png_color_8p *sig_bit)); 2095 #endif 2096 2097 #ifdef PNG_sBIT_SUPPORTED 2098 PNG_EXPORT(154, void, png_set_sBIT, (png_const_structrp png_ptr, 2099 png_inforp info_ptr, png_const_color_8p sig_bit)); 2100 #endif 2101 2102 #ifdef PNG_sRGB_SUPPORTED 2103 PNG_EXPORT(155, png_uint_32, png_get_sRGB, (png_const_structrp png_ptr, 2104 png_const_inforp info_ptr, int *file_srgb_intent)); 2105 #endif 2106 2107 #ifdef PNG_sRGB_SUPPORTED 2108 PNG_EXPORT(156, void, png_set_sRGB, (png_const_structrp png_ptr, 2109 png_inforp info_ptr, int srgb_intent)); 2110 PNG_EXPORT(157, void, png_set_sRGB_gAMA_and_cHRM, (png_const_structrp png_ptr, 2111 png_inforp info_ptr, int srgb_intent)); 2112 #endif 2113 2114 #ifdef PNG_iCCP_SUPPORTED 2115 PNG_EXPORT(158, png_uint_32, png_get_iCCP, (png_const_structrp png_ptr, 2116 png_inforp info_ptr, png_charpp name, int *compression_type, 2117 png_bytepp profile, png_uint_32 *proflen)); 2118 #endif 2119 2120 #ifdef PNG_iCCP_SUPPORTED 2121 PNG_EXPORT(159, void, png_set_iCCP, (png_const_structrp png_ptr, 2122 png_inforp info_ptr, png_const_charp name, int compression_type, 2123 png_const_bytep profile, png_uint_32 proflen)); 2124 #endif 2125 2126 #ifdef PNG_sPLT_SUPPORTED 2127 PNG_EXPORT(160, int, png_get_sPLT, (png_const_structrp png_ptr, 2128 png_inforp info_ptr, png_sPLT_tpp entries)); 2129 #endif 2130 2131 #ifdef PNG_sPLT_SUPPORTED 2132 PNG_EXPORT(161, void, png_set_sPLT, (png_const_structrp png_ptr, 2133 png_inforp info_ptr, png_const_sPLT_tp entries, int nentries)); 2134 #endif 2135 2136 #ifdef PNG_TEXT_SUPPORTED 2137 /* png_get_text also returns the number of text chunks in *num_text */ 2138 PNG_EXPORT(162, int, png_get_text, (png_const_structrp png_ptr, 2139 png_inforp info_ptr, png_textp *text_ptr, int *num_text)); 2140 #endif 2141 2142 /* Note while png_set_text() will accept a structure whose text, 2143 * language, and translated keywords are NULL pointers, the structure 2144 * returned by png_get_text will always contain regular 2145 * zero-terminated C strings. They might be empty strings but 2146 * they will never be NULL pointers. 2147 */ 2148 2149 #ifdef PNG_TEXT_SUPPORTED 2150 PNG_EXPORT(163, void, png_set_text, (png_const_structrp png_ptr, 2151 png_inforp info_ptr, png_const_textp text_ptr, int num_text)); 2152 #endif 2153 2154 #ifdef PNG_tIME_SUPPORTED 2155 PNG_EXPORT(164, png_uint_32, png_get_tIME, (png_const_structrp png_ptr, 2156 png_inforp info_ptr, png_timep *mod_time)); 2157 #endif 2158 2159 #ifdef PNG_tIME_SUPPORTED 2160 PNG_EXPORT(165, void, png_set_tIME, (png_const_structrp png_ptr, 2161 png_inforp info_ptr, png_const_timep mod_time)); 2162 #endif 2163 2164 #ifdef PNG_tRNS_SUPPORTED 2165 PNG_EXPORT(166, png_uint_32, png_get_tRNS, (png_const_structrp png_ptr, 2166 png_inforp info_ptr, png_bytep *trans_alpha, int *num_trans, 2167 png_color_16p *trans_color)); 2168 #endif 2169 2170 #ifdef PNG_tRNS_SUPPORTED 2171 PNG_EXPORT(167, void, png_set_tRNS, (png_structrp png_ptr, 2172 png_inforp info_ptr, png_const_bytep trans_alpha, int num_trans, 2173 png_const_color_16p trans_color)); 2174 #endif 2175 2176 #ifdef PNG_sCAL_SUPPORTED 2177 PNG_FP_EXPORT(168, png_uint_32, png_get_sCAL, (png_const_structrp png_ptr, 2178 png_const_inforp info_ptr, int *unit, double *width, double *height)) 2179 #if defined(PNG_FLOATING_ARITHMETIC_SUPPORTED) || \ 2180 defined(PNG_FLOATING_POINT_SUPPORTED) 2181 /* NOTE: this API is currently implemented using floating point arithmetic, 2182 * consequently it can only be used on systems with floating point support. 2183 * In any case the range of values supported by png_fixed_point is small and it 2184 * is highly recommended that png_get_sCAL_s be used instead. 2185 */ 2186 PNG_FIXED_EXPORT(214, png_uint_32, png_get_sCAL_fixed, 2187 (png_const_structrp png_ptr, png_const_inforp info_ptr, int *unit, 2188 png_fixed_point *width, png_fixed_point *height)) 2189 #endif 2190 PNG_EXPORT(169, png_uint_32, png_get_sCAL_s, 2191 (png_const_structrp png_ptr, png_const_inforp info_ptr, int *unit, 2192 png_charpp swidth, png_charpp sheight)); 2193 2194 PNG_FP_EXPORT(170, void, png_set_sCAL, (png_const_structrp png_ptr, 2195 png_inforp info_ptr, int unit, double width, double height)) 2196 PNG_FIXED_EXPORT(213, void, png_set_sCAL_fixed, (png_const_structrp png_ptr, 2197 png_inforp info_ptr, int unit, png_fixed_point width, 2198 png_fixed_point height)) 2199 PNG_EXPORT(171, void, png_set_sCAL_s, (png_const_structrp png_ptr, 2200 png_inforp info_ptr, int unit, 2201 png_const_charp swidth, png_const_charp sheight)); 2202 #endif /* sCAL */ 2203 2204 #ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED 2205 /* Provide the default handling for all unknown chunks or, optionally, for 2206 * specific unknown chunks. 2207 * 2208 * NOTE: prior to 1.6.0 the handling specified for particular chunks on read was 2209 * ignored and the default was used, the per-chunk setting only had an effect on 2210 * write. If you wish to have chunk-specific handling on read in code that must 2211 * work on earlier versions you must use a user chunk callback to specify the 2212 * desired handling (keep or discard.) 2213 * 2214 * The 'keep' parameter is a PNG_HANDLE_CHUNK_ value as listed below. The 2215 * parameter is interpreted as follows: 2216 * 2217 * READ: 2218 * PNG_HANDLE_CHUNK_AS_DEFAULT: 2219 * Known chunks: do normal libpng processing, do not keep the chunk (but 2220 * see the comments below about PNG_HANDLE_AS_UNKNOWN_SUPPORTED) 2221 * Unknown chunks: for a specific chunk use the global default, when used 2222 * as the default discard the chunk data. 2223 * PNG_HANDLE_CHUNK_NEVER: 2224 * Discard the chunk data. 2225 * PNG_HANDLE_CHUNK_IF_SAFE: 2226 * Keep the chunk data if the chunk is not critical else raise a chunk 2227 * error. 2228 * PNG_HANDLE_CHUNK_ALWAYS: 2229 * Keep the chunk data. 2230 * 2231 * If the chunk data is saved it can be retrieved using png_get_unknown_chunks, 2232 * below. Notice that specifying "AS_DEFAULT" as a global default is equivalent 2233 * to specifying "NEVER", however when "AS_DEFAULT" is used for specific chunks 2234 * it simply resets the behavior to the libpng default. 2235 * 2236 * INTERACTION WTIH USER CHUNK CALLBACKS: 2237 * The per-chunk handling is always used when there is a png_user_chunk_ptr 2238 * callback and the callback returns 0; the chunk is then always stored *unless* 2239 * it is critical and the per-chunk setting is other than ALWAYS. Notice that 2240 * the global default is *not* used in this case. (In effect the per-chunk 2241 * value is incremented to at least IF_SAFE.) 2242 * 2243 * IMPORTANT NOTE: this behavior will change in libpng 1.7 - the global and 2244 * per-chunk defaults will be honored. If you want to preserve the current 2245 * behavior when your callback returns 0 you must set PNG_HANDLE_CHUNK_IF_SAFE 2246 * as the default - if you don't do this libpng 1.6 will issue a warning. 2247 * 2248 * If you want unhandled unknown chunks to be discarded in libpng 1.6 and 2249 * earlier simply return '1' (handled). 2250 * 2251 * PNG_HANDLE_AS_UNKNOWN_SUPPORTED: 2252 * If this is *not* set known chunks will always be handled by libpng and 2253 * will never be stored in the unknown chunk list. Known chunks listed to 2254 * png_set_keep_unknown_chunks will have no effect. If it is set then known 2255 * chunks listed with a keep other than AS_DEFAULT will *never* be processed 2256 * by libpng, in addition critical chunks must either be processed by the 2257 * callback or saved. 2258 * 2259 * The IHDR and IEND chunks must not be listed. Because this turns off the 2260 * default handling for chunks that would otherwise be recognized the 2261 * behavior of libpng transformations may well become incorrect! 2262 * 2263 * WRITE: 2264 * When writing chunks the options only apply to the chunks specified by 2265 * png_set_unknown_chunks (below), libpng will *always* write known chunks 2266 * required by png_set_ calls and will always write the core critical chunks 2267 * (as required for PLTE). 2268 * 2269 * Each chunk in the png_set_unknown_chunks list is looked up in the 2270 * png_set_keep_unknown_chunks list to find the keep setting, this is then 2271 * interpreted as follows: 2272 * 2273 * PNG_HANDLE_CHUNK_AS_DEFAULT: 2274 * Write safe-to-copy chunks and write other chunks if the global 2275 * default is set to _ALWAYS, otherwise don't write this chunk. 2276 * PNG_HANDLE_CHUNK_NEVER: 2277 * Do not write the chunk. 2278 * PNG_HANDLE_CHUNK_IF_SAFE: 2279 * Write the chunk if it is safe-to-copy, otherwise do not write it. 2280 * PNG_HANDLE_CHUNK_ALWAYS: 2281 * Write the chunk. 2282 * 2283 * Note that the default behavior is effectively the opposite of the read case - 2284 * in read unknown chunks are not stored by default, in write they are written 2285 * by default. Also the behavior of PNG_HANDLE_CHUNK_IF_SAFE is very different 2286 * - on write the safe-to-copy bit is checked, on read the critical bit is 2287 * checked and on read if the chunk is critical an error will be raised. 2288 * 2289 * num_chunks: 2290 * =========== 2291 * If num_chunks is positive, then the "keep" parameter specifies the manner 2292 * for handling only those chunks appearing in the chunk_list array, 2293 * otherwise the chunk list array is ignored. 2294 * 2295 * If num_chunks is 0 the "keep" parameter specifies the default behavior for 2296 * unknown chunks, as described above. 2297 * 2298 * If num_chunks is negative, then the "keep" parameter specifies the manner 2299 * for handling all unknown chunks plus all chunks recognized by libpng 2300 * except for the IHDR, PLTE, tRNS, IDAT, and IEND chunks (which continue to 2301 * be processed by libpng. 2302 */ 2303 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED 2304 PNG_EXPORT(172, void, png_set_keep_unknown_chunks, (png_structrp png_ptr, 2305 int keep, png_const_bytep chunk_list, int num_chunks)); 2306 #endif /* HANDLE_AS_UNKNOWN */ 2307 2308 /* The "keep" PNG_HANDLE_CHUNK_ parameter for the specified chunk is returned; 2309 * the result is therefore true (non-zero) if special handling is required, 2310 * false for the default handling. 2311 */ 2312 PNG_EXPORT(173, int, png_handle_as_unknown, (png_const_structrp png_ptr, 2313 png_const_bytep chunk_name)); 2314 #endif /* SET_UNKNOWN_CHUNKS */ 2315 2316 #ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED 2317 PNG_EXPORT(174, void, png_set_unknown_chunks, (png_const_structrp png_ptr, 2318 png_inforp info_ptr, png_const_unknown_chunkp unknowns, 2319 int num_unknowns)); 2320 /* NOTE: prior to 1.6.0 this routine set the 'location' field of the added 2321 * unknowns to the location currently stored in the png_struct. This is 2322 * invariably the wrong value on write. To fix this call the following API 2323 * for each chunk in the list with the correct location. If you know your 2324 * code won't be compiled on earlier versions you can rely on 2325 * png_set_unknown_chunks(write-ptr, png_get_unknown_chunks(read-ptr)) doing 2326 * the correct thing. 2327 */ 2328 2329 PNG_EXPORT(175, void, png_set_unknown_chunk_location, 2330 (png_const_structrp png_ptr, png_inforp info_ptr, int chunk, int location)); 2331 2332 PNG_EXPORT(176, int, png_get_unknown_chunks, (png_const_structrp png_ptr, 2333 png_inforp info_ptr, png_unknown_chunkpp entries)); 2334 #endif 2335 2336 /* Png_free_data() will turn off the "valid" flag for anything it frees. 2337 * If you need to turn it off for a chunk that your application has freed, 2338 * you can use png_set_invalid(png_ptr, info_ptr, PNG_INFO_CHNK); 2339 */ 2340 PNG_EXPORT(177, void, png_set_invalid, (png_const_structrp png_ptr, 2341 png_inforp info_ptr, int mask)); 2342 2343 #ifdef PNG_INFO_IMAGE_SUPPORTED 2344 /* The "params" pointer is currently not used and is for future expansion. */ 2345 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED 2346 PNG_EXPORT(178, void, png_read_png, (png_structrp png_ptr, png_inforp info_ptr, 2347 int transforms, png_voidp params)); 2348 #endif 2349 #ifdef PNG_WRITE_SUPPORTED 2350 PNG_EXPORT(179, void, png_write_png, (png_structrp png_ptr, png_inforp info_ptr, 2351 int transforms, png_voidp params)); 2352 #endif 2353 #endif 2354 2355 PNG_EXPORT(180, png_const_charp, png_get_copyright, 2356 (png_const_structrp png_ptr)); 2357 PNG_EXPORT(181, png_const_charp, png_get_header_ver, 2358 (png_const_structrp png_ptr)); 2359 PNG_EXPORT(182, png_const_charp, png_get_header_version, 2360 (png_const_structrp png_ptr)); 2361 PNG_EXPORT(183, png_const_charp, png_get_libpng_ver, 2362 (png_const_structrp png_ptr)); 2363 2364 #ifdef PNG_MNG_FEATURES_SUPPORTED 2365 PNG_EXPORT(184, png_uint_32, png_permit_mng_features, (png_structrp png_ptr, 2366 png_uint_32 mng_features_permitted)); 2367 #endif 2368 2369 /* For use in png_set_keep_unknown, added to version 1.2.6 */ 2370 #define PNG_HANDLE_CHUNK_AS_DEFAULT 0 2371 #define PNG_HANDLE_CHUNK_NEVER 1 2372 #define PNG_HANDLE_CHUNK_IF_SAFE 2 2373 #define PNG_HANDLE_CHUNK_ALWAYS 3 2374 #define PNG_HANDLE_CHUNK_LAST 4 2375 2376 /* Strip the prepended error numbers ("#nnn ") from error and warning 2377 * messages before passing them to the error or warning handler. 2378 */ 2379 #ifdef PNG_ERROR_NUMBERS_SUPPORTED 2380 PNG_EXPORT(185, void, png_set_strip_error_numbers, (png_structrp png_ptr, 2381 png_uint_32 strip_mode)); 2382 #endif 2383 2384 /* Added in libpng-1.2.6 */ 2385 #ifdef PNG_SET_USER_LIMITS_SUPPORTED 2386 PNG_EXPORT(186, void, png_set_user_limits, (png_structrp png_ptr, 2387 png_uint_32 user_width_max, png_uint_32 user_height_max)); 2388 PNG_EXPORT(187, png_uint_32, png_get_user_width_max, 2389 (png_const_structrp png_ptr)); 2390 PNG_EXPORT(188, png_uint_32, png_get_user_height_max, 2391 (png_const_structrp png_ptr)); 2392 /* Added in libpng-1.4.0 */ 2393 PNG_EXPORT(189, void, png_set_chunk_cache_max, (png_structrp png_ptr, 2394 png_uint_32 user_chunk_cache_max)); 2395 PNG_EXPORT(190, png_uint_32, png_get_chunk_cache_max, 2396 (png_const_structrp png_ptr)); 2397 /* Added in libpng-1.4.1 */ 2398 PNG_EXPORT(191, void, png_set_chunk_malloc_max, (png_structrp png_ptr, 2399 png_alloc_size_t user_chunk_cache_max)); 2400 PNG_EXPORT(192, png_alloc_size_t, png_get_chunk_malloc_max, 2401 (png_const_structrp png_ptr)); 2402 #endif 2403 2404 #if defined(PNG_INCH_CONVERSIONS_SUPPORTED) 2405 PNG_EXPORT(193, png_uint_32, png_get_pixels_per_inch, 2406 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 2407 2408 PNG_EXPORT(194, png_uint_32, png_get_x_pixels_per_inch, 2409 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 2410 2411 PNG_EXPORT(195, png_uint_32, png_get_y_pixels_per_inch, 2412 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 2413 2414 PNG_FP_EXPORT(196, float, png_get_x_offset_inches, 2415 (png_const_structrp png_ptr, png_const_inforp info_ptr)) 2416 #ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */ 2417 PNG_FIXED_EXPORT(211, png_fixed_point, png_get_x_offset_inches_fixed, 2418 (png_const_structrp png_ptr, png_const_inforp info_ptr)) 2419 #endif 2420 2421 PNG_FP_EXPORT(197, float, png_get_y_offset_inches, (png_const_structrp png_ptr, 2422 png_const_inforp info_ptr)) 2423 #ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */ 2424 PNG_FIXED_EXPORT(212, png_fixed_point, png_get_y_offset_inches_fixed, 2425 (png_const_structrp png_ptr, png_const_inforp info_ptr)) 2426 #endif 2427 2428 # ifdef PNG_pHYs_SUPPORTED 2429 PNG_EXPORT(198, png_uint_32, png_get_pHYs_dpi, (png_const_structrp png_ptr, 2430 png_const_inforp info_ptr, png_uint_32 *res_x, png_uint_32 *res_y, 2431 int *unit_type)); 2432 # endif /* pHYs */ 2433 #endif /* INCH_CONVERSIONS */ 2434 2435 /* Added in libpng-1.4.0 */ 2436 #ifdef PNG_IO_STATE_SUPPORTED 2437 PNG_EXPORT(199, png_uint_32, png_get_io_state, (png_const_structrp png_ptr)); 2438 2439 /* Removed from libpng 1.6; use png_get_io_chunk_type. */ 2440 PNG_REMOVED(200, png_const_bytep, png_get_io_chunk_name, (png_structrp png_ptr), 2441 PNG_DEPRECATED) 2442 2443 PNG_EXPORT(216, png_uint_32, png_get_io_chunk_type, 2444 (png_const_structrp png_ptr)); 2445 2446 /* The flags returned by png_get_io_state() are the following: */ 2447 # define PNG_IO_NONE 0x0000 /* no I/O at this moment */ 2448 # define PNG_IO_READING 0x0001 /* currently reading */ 2449 # define PNG_IO_WRITING 0x0002 /* currently writing */ 2450 # define PNG_IO_SIGNATURE 0x0010 /* currently at the file signature */ 2451 # define PNG_IO_CHUNK_HDR 0x0020 /* currently at the chunk header */ 2452 # define PNG_IO_CHUNK_DATA 0x0040 /* currently at the chunk data */ 2453 # define PNG_IO_CHUNK_CRC 0x0080 /* currently at the chunk crc */ 2454 # define PNG_IO_MASK_OP 0x000f /* current operation: reading/writing */ 2455 # define PNG_IO_MASK_LOC 0x00f0 /* current location: sig/hdr/data/crc */ 2456 #endif /* IO_STATE */ 2457 2458 /* Interlace support. The following macros are always defined so that if 2459 * libpng interlace handling is turned off the macros may be used to handle 2460 * interlaced images within the application. 2461 */ 2462 #define PNG_INTERLACE_ADAM7_PASSES 7 2463 2464 /* Two macros to return the first row and first column of the original, 2465 * full, image which appears in a given pass. 'pass' is in the range 0 2466 * to 6 and the result is in the range 0 to 7. 2467 */ 2468 #define PNG_PASS_START_ROW(pass) (((1&~(pass))<<(3-((pass)>>1)))&7) 2469 #define PNG_PASS_START_COL(pass) (((1& (pass))<<(3-(((pass)+1)>>1)))&7) 2470 2471 /* A macro to return the offset between pixels in the output row for a pair of 2472 * pixels in the input - effectively the inverse of the 'COL_SHIFT' macro that 2473 * follows. Note that ROW_OFFSET is the offset from one row to the next whereas 2474 * COL_OFFSET is from one column to the next, within a row. 2475 */ 2476 #define PNG_PASS_ROW_OFFSET(pass) ((pass)>2?(8>>(((pass)-1)>>1)):8) 2477 #define PNG_PASS_COL_OFFSET(pass) (1<<((7-(pass))>>1)) 2478 2479 /* Two macros to help evaluate the number of rows or columns in each 2480 * pass. This is expressed as a shift - effectively log2 of the number or 2481 * rows or columns in each 8x8 tile of the original image. 2482 */ 2483 #define PNG_PASS_ROW_SHIFT(pass) ((pass)>2?(8-(pass))>>1:3) 2484 #define PNG_PASS_COL_SHIFT(pass) ((pass)>1?(7-(pass))>>1:3) 2485 2486 /* Hence two macros to determine the number of rows or columns in a given 2487 * pass of an image given its height or width. In fact these macros may 2488 * return non-zero even though the sub-image is empty, because the other 2489 * dimension may be empty for a small image. 2490 */ 2491 #define PNG_PASS_ROWS(height, pass) (((height)+(((1<<PNG_PASS_ROW_SHIFT(pass))\ 2492 -1)-PNG_PASS_START_ROW(pass)))>>PNG_PASS_ROW_SHIFT(pass)) 2493 #define PNG_PASS_COLS(width, pass) (((width)+(((1<<PNG_PASS_COL_SHIFT(pass))\ 2494 -1)-PNG_PASS_START_COL(pass)))>>PNG_PASS_COL_SHIFT(pass)) 2495 2496 /* For the reader row callbacks (both progressive and sequential) it is 2497 * necessary to find the row in the output image given a row in an interlaced 2498 * image, so two more macros: 2499 */ 2500 #define PNG_ROW_FROM_PASS_ROW(y_in, pass) \ 2501 (((y_in)<<PNG_PASS_ROW_SHIFT(pass))+PNG_PASS_START_ROW(pass)) 2502 #define PNG_COL_FROM_PASS_COL(x_in, pass) \ 2503 (((x_in)<<PNG_PASS_COL_SHIFT(pass))+PNG_PASS_START_COL(pass)) 2504 2505 /* Two macros which return a boolean (0 or 1) saying whether the given row 2506 * or column is in a particular pass. These use a common utility macro that 2507 * returns a mask for a given pass - the offset 'off' selects the row or 2508 * column version. The mask has the appropriate bit set for each column in 2509 * the tile. 2510 */ 2511 #define PNG_PASS_MASK(pass,off) ( \ 2512 ((0x110145AF>>(((7-(off))-(pass))<<2)) & 0xF) | \ 2513 ((0x01145AF0>>(((7-(off))-(pass))<<2)) & 0xF0)) 2514 2515 #define PNG_ROW_IN_INTERLACE_PASS(y, pass) \ 2516 ((PNG_PASS_MASK(pass,0) >> ((y)&7)) & 1) 2517 #define PNG_COL_IN_INTERLACE_PASS(x, pass) \ 2518 ((PNG_PASS_MASK(pass,1) >> ((x)&7)) & 1) 2519 2520 #ifdef PNG_READ_COMPOSITE_NODIV_SUPPORTED 2521 /* With these routines we avoid an integer divide, which will be slower on 2522 * most machines. However, it does take more operations than the corresponding 2523 * divide method, so it may be slower on a few RISC systems. There are two 2524 * shifts (by 8 or 16 bits) and an addition, versus a single integer divide. 2525 * 2526 * Note that the rounding factors are NOT supposed to be the same! 128 and 2527 * 32768 are correct for the NODIV code; 127 and 32767 are correct for the 2528 * standard method. 2529 * 2530 * [Optimized code by Greg Roelofs and Mark Adler...blame us for bugs. :-) ] 2531 */ 2532 2533 /* fg and bg should be in `gamma 1.0' space; alpha is the opacity */ 2534 2535 # define png_composite(composite, fg, alpha, bg) \ 2536 { \ 2537 png_uint_16 temp = (png_uint_16)((png_uint_16)(fg) \ 2538 * (png_uint_16)(alpha) \ 2539 + (png_uint_16)(bg)*(png_uint_16)(255 \ 2540 - (png_uint_16)(alpha)) + 128); \ 2541 (composite) = (png_byte)(((temp + (temp >> 8)) >> 8) & 0xff); \ 2542 } 2543 2544 # define png_composite_16(composite, fg, alpha, bg) \ 2545 { \ 2546 png_uint_32 temp = (png_uint_32)((png_uint_32)(fg) \ 2547 * (png_uint_32)(alpha) \ 2548 + (png_uint_32)(bg)*(65535 \ 2549 - (png_uint_32)(alpha)) + 32768); \ 2550 (composite) = (png_uint_16)(0xffff & ((temp + (temp >> 16)) >> 16)); \ 2551 } 2552 2553 #else /* Standard method using integer division */ 2554 2555 # define png_composite(composite, fg, alpha, bg) \ 2556 (composite) = \ 2557 (png_byte)(0xff & (((png_uint_16)(fg) * (png_uint_16)(alpha) + \ 2558 (png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) + \ 2559 127) / 255)) 2560 2561 # define png_composite_16(composite, fg, alpha, bg) \ 2562 (composite) = \ 2563 (png_uint_16)(0xffff & (((png_uint_32)(fg) * (png_uint_32)(alpha) + \ 2564 (png_uint_32)(bg)*(png_uint_32)(65535 - (png_uint_32)(alpha)) + \ 2565 32767) / 65535)) 2566 #endif /* READ_COMPOSITE_NODIV */ 2567 2568 #ifdef PNG_READ_INT_FUNCTIONS_SUPPORTED 2569 PNG_EXPORT(201, png_uint_32, png_get_uint_32, (png_const_bytep buf)); 2570 PNG_EXPORT(202, png_uint_16, png_get_uint_16, (png_const_bytep buf)); 2571 PNG_EXPORT(203, png_int_32, png_get_int_32, (png_const_bytep buf)); 2572 #endif 2573 2574 PNG_EXPORT(204, png_uint_32, png_get_uint_31, (png_const_structrp png_ptr, 2575 png_const_bytep buf)); 2576 /* No png_get_int_16 -- may be added if there's a real need for it. */ 2577 2578 /* Place a 32-bit number into a buffer in PNG byte order (big-endian). */ 2579 #ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED 2580 PNG_EXPORT(205, void, png_save_uint_32, (png_bytep buf, png_uint_32 i)); 2581 #endif 2582 #ifdef PNG_SAVE_INT_32_SUPPORTED 2583 PNG_EXPORT(206, void, png_save_int_32, (png_bytep buf, png_int_32 i)); 2584 #endif 2585 2586 /* Place a 16-bit number into a buffer in PNG byte order. 2587 * The parameter is declared unsigned int, not png_uint_16, 2588 * just to avoid potential problems on pre-ANSI C compilers. 2589 */ 2590 #ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED 2591 PNG_EXPORT(207, void, png_save_uint_16, (png_bytep buf, unsigned int i)); 2592 /* No png_save_int_16 -- may be added if there's a real need for it. */ 2593 #endif 2594 2595 #ifdef PNG_USE_READ_MACROS 2596 /* Inline macros to do direct reads of bytes from the input buffer. 2597 * The png_get_int_32() routine assumes we are using two's complement 2598 * format for negative values, which is almost certainly true. 2599 */ 2600 # define PNG_get_uint_32(buf) \ 2601 (((png_uint_32)(*(buf)) << 24) + \ 2602 ((png_uint_32)(*((buf) + 1)) << 16) + \ 2603 ((png_uint_32)(*((buf) + 2)) << 8) + \ 2604 ((png_uint_32)(*((buf) + 3)))) 2605 2606 /* From libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the 2607 * function) incorrectly returned a value of type png_uint_32. 2608 */ 2609 # define PNG_get_uint_16(buf) \ 2610 ((png_uint_16) \ 2611 (((unsigned int)(*(buf)) << 8) + \ 2612 ((unsigned int)(*((buf) + 1))))) 2613 2614 # define PNG_get_int_32(buf) \ 2615 ((png_int_32)((*(buf) & 0x80) \ 2616 ? -((png_int_32)(((png_get_uint_32(buf)^0xffffffffU)+1U)&0x7fffffffU)) \ 2617 : (png_int_32)png_get_uint_32(buf))) 2618 2619 /* If PNG_PREFIX is defined the same thing as below happens in pnglibconf.h, 2620 * but defining a macro name prefixed with PNG_PREFIX. 2621 */ 2622 # ifndef PNG_PREFIX 2623 # define png_get_uint_32(buf) PNG_get_uint_32(buf) 2624 # define png_get_uint_16(buf) PNG_get_uint_16(buf) 2625 # define png_get_int_32(buf) PNG_get_int_32(buf) 2626 # endif 2627 #else 2628 # ifdef PNG_PREFIX 2629 /* No macros; revert to the (redefined) function */ 2630 # define PNG_get_uint_32 (png_get_uint_32) 2631 # define PNG_get_uint_16 (png_get_uint_16) 2632 # define PNG_get_int_32 (png_get_int_32) 2633 # endif 2634 #endif 2635 2636 #ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED 2637 PNG_EXPORT(242, void, png_set_check_for_invalid_index, 2638 (png_structrp png_ptr, int allowed)); 2639 # ifdef PNG_GET_PALETTE_MAX_SUPPORTED 2640 PNG_EXPORT(243, int, png_get_palette_max, (png_const_structp png_ptr, 2641 png_const_infop info_ptr)); 2642 # endif 2643 #endif /* CHECK_FOR_INVALID_INDEX */ 2644 2645 /******************************************************************************* 2646 * Section 5: SIMPLIFIED API 2647 ******************************************************************************* 2648 * 2649 * Please read the documentation in libpng-manual.txt (TODO: write said 2650 * documentation) if you don't understand what follows. 2651 * 2652 * The simplified API hides the details of both libpng and the PNG file format 2653 * itself. It allows PNG files to be read into a very limited number of 2654 * in-memory bitmap formats or to be written from the same formats. If these 2655 * formats do not accomodate your needs then you can, and should, use the more 2656 * sophisticated APIs above - these support a wide variety of in-memory formats 2657 * and a wide variety of sophisticated transformations to those formats as well 2658 * as a wide variety of APIs to manipulate ancillary information. 2659 * 2660 * To read a PNG file using the simplified API: 2661 * 2662 * 1) Declare a 'png_image' structure (see below) on the stack, set the 2663 * version field to PNG_IMAGE_VERSION and the 'opaque' pointer to NULL 2664 * (this is REQUIRED, your program may crash if you don't do it.) 2665 * 2) Call the appropriate png_image_begin_read... function. 2666 * 3) Set the png_image 'format' member to the required sample format. 2667 * 4) Allocate a buffer for the image and, if required, the color-map. 2668 * 5) Call png_image_finish_read to read the image and, if required, the 2669 * color-map into your buffers. 2670 * 2671 * There are no restrictions on the format of the PNG input itself; all valid 2672 * color types, bit depths, and interlace methods are acceptable, and the 2673 * input image is transformed as necessary to the requested in-memory format 2674 * during the png_image_finish_read() step. The only caveat is that if you 2675 * request a color-mapped image from a PNG that is full-color or makes 2676 * complex use of an alpha channel the transformation is extremely lossy and the 2677 * result may look terrible. 2678 * 2679 * To write a PNG file using the simplified API: 2680 * 2681 * 1) Declare a 'png_image' structure on the stack and memset() it to all zero. 2682 * 2) Initialize the members of the structure that describe the image, setting 2683 * the 'format' member to the format of the image samples. 2684 * 3) Call the appropriate png_image_write... function with a pointer to the 2685 * image and, if necessary, the color-map to write the PNG data. 2686 * 2687 * png_image is a structure that describes the in-memory format of an image 2688 * when it is being read or defines the in-memory format of an image that you 2689 * need to write: 2690 */ 2691 #if defined(PNG_SIMPLIFIED_READ_SUPPORTED) || \ 2692 defined(PNG_SIMPLIFIED_WRITE_SUPPORTED) 2693 2694 #define PNG_IMAGE_VERSION 1 2695 2696 typedef struct png_control *png_controlp; 2697 typedef struct 2698 { 2699 png_controlp opaque; /* Initialize to NULL, free with png_image_free */ 2700 png_uint_32 version; /* Set to PNG_IMAGE_VERSION */ 2701 png_uint_32 width; /* Image width in pixels (columns) */ 2702 png_uint_32 height; /* Image height in pixels (rows) */ 2703 png_uint_32 format; /* Image format as defined below */ 2704 png_uint_32 flags; /* A bit mask containing informational flags */ 2705 png_uint_32 colormap_entries; 2706 /* Number of entries in the color-map */ 2707 2708 /* In the event of an error or warning the following field will be set to a 2709 * non-zero value and the 'message' field will contain a '\0' terminated 2710 * string with the libpng error or warning message. If both warnings and 2711 * an error were encountered, only the error is recorded. If there 2712 * are multiple warnings, only the first one is recorded. 2713 * 2714 * The upper 30 bits of this value are reserved, the low two bits contain 2715 * a value as follows: 2716 */ 2717 # define PNG_IMAGE_WARNING 1 2718 # define PNG_IMAGE_ERROR 2 2719 /* 2720 * The result is a two-bit code such that a value more than 1 indicates 2721 * a failure in the API just called: 2722 * 2723 * 0 - no warning or error 2724 * 1 - warning 2725 * 2 - error 2726 * 3 - error preceded by warning 2727 */ 2728 # define PNG_IMAGE_FAILED(png_cntrl) ((((png_cntrl).warning_or_error)&0x03)>1) 2729 2730 png_uint_32 warning_or_error; 2731 2732 char message[64]; 2733 } png_image, *png_imagep; 2734 2735 /* The samples of the image have one to four channels whose components have 2736 * original values in the range 0 to 1.0: 2737 * 2738 * 1: A single gray or luminance channel (G). 2739 * 2: A gray/luminance channel and an alpha channel (GA). 2740 * 3: Three red, green, blue color channels (RGB). 2741 * 4: Three color channels and an alpha channel (RGBA). 2742 * 2743 * The components are encoded in one of two ways: 2744 * 2745 * a) As a small integer, value 0..255, contained in a single byte. For the 2746 * alpha channel the original value is simply value/255. For the color or 2747 * luminance channels the value is encoded according to the sRGB specification 2748 * and matches the 8-bit format expected by typical display devices. 2749 * 2750 * The color/gray channels are not scaled (pre-multiplied) by the alpha 2751 * channel and are suitable for passing to color management software. 2752 * 2753 * b) As a value in the range 0..65535, contained in a 2-byte integer. All 2754 * channels can be converted to the original value by dividing by 65535; all 2755 * channels are linear. Color channels use the RGB encoding (RGB end-points) of 2756 * the sRGB specification. This encoding is identified by the 2757 * PNG_FORMAT_FLAG_LINEAR flag below. 2758 * 2759 * When the simplified API needs to convert between sRGB and linear colorspaces, 2760 * the actual sRGB transfer curve defined in the sRGB specification (see the 2761 * article at http://en.wikipedia.org/wiki/SRGB) is used, not the gamma=1/2.2 2762 * approximation used elsewhere in libpng. 2763 * 2764 * When an alpha channel is present it is expected to denote pixel coverage 2765 * of the color or luminance channels and is returned as an associated alpha 2766 * channel: the color/gray channels are scaled (pre-multiplied) by the alpha 2767 * value. 2768 * 2769 * The samples are either contained directly in the image data, between 1 and 8 2770 * bytes per pixel according to the encoding, or are held in a color-map indexed 2771 * by bytes in the image data. In the case of a color-map the color-map entries 2772 * are individual samples, encoded as above, and the image data has one byte per 2773 * pixel to select the relevant sample from the color-map. 2774 */ 2775 2776 /* PNG_FORMAT_* 2777 * 2778 * #defines to be used in png_image::format. Each #define identifies a 2779 * particular layout of sample data and, if present, alpha values. There are 2780 * separate defines for each of the two component encodings. 2781 * 2782 * A format is built up using single bit flag values. All combinations are 2783 * valid. Formats can be built up from the flag values or you can use one of 2784 * the predefined values below. When testing formats always use the FORMAT_FLAG 2785 * macros to test for individual features - future versions of the library may 2786 * add new flags. 2787 * 2788 * When reading or writing color-mapped images the format should be set to the 2789 * format of the entries in the color-map then png_image_{read,write}_colormap 2790 * called to read or write the color-map and set the format correctly for the 2791 * image data. Do not set the PNG_FORMAT_FLAG_COLORMAP bit directly! 2792 * 2793 * NOTE: libpng can be built with particular features disabled. If you see 2794 * compiler errors because the definition of one of the following flags has been 2795 * compiled out it is because libpng does not have the required support. It is 2796 * possible, however, for the libpng configuration to enable the format on just 2797 * read or just write; in that case you may see an error at run time. You can 2798 * guard against this by checking for the definition of the appropriate 2799 * "_SUPPORTED" macro, one of: 2800 * 2801 * PNG_SIMPLIFIED_{READ,WRITE}_{BGR,AFIRST}_SUPPORTED 2802 */ 2803 #define PNG_FORMAT_FLAG_ALPHA 0x01U /* format with an alpha channel */ 2804 #define PNG_FORMAT_FLAG_COLOR 0x02U /* color format: otherwise grayscale */ 2805 #define PNG_FORMAT_FLAG_LINEAR 0x04U /* 2-byte channels else 1-byte */ 2806 #define PNG_FORMAT_FLAG_COLORMAP 0x08U /* image data is color-mapped */ 2807 2808 #ifdef PNG_FORMAT_BGR_SUPPORTED 2809 # define PNG_FORMAT_FLAG_BGR 0x10U /* BGR colors, else order is RGB */ 2810 #endif 2811 2812 #ifdef PNG_FORMAT_AFIRST_SUPPORTED 2813 # define PNG_FORMAT_FLAG_AFIRST 0x20U /* alpha channel comes first */ 2814 #endif 2815 2816 /* Commonly used formats have predefined macros. 2817 * 2818 * First the single byte (sRGB) formats: 2819 */ 2820 #define PNG_FORMAT_GRAY 0 2821 #define PNG_FORMAT_GA PNG_FORMAT_FLAG_ALPHA 2822 #define PNG_FORMAT_AG (PNG_FORMAT_GA|PNG_FORMAT_FLAG_AFIRST) 2823 #define PNG_FORMAT_RGB PNG_FORMAT_FLAG_COLOR 2824 #define PNG_FORMAT_BGR (PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_BGR) 2825 #define PNG_FORMAT_RGBA (PNG_FORMAT_RGB|PNG_FORMAT_FLAG_ALPHA) 2826 #define PNG_FORMAT_ARGB (PNG_FORMAT_RGBA|PNG_FORMAT_FLAG_AFIRST) 2827 #define PNG_FORMAT_BGRA (PNG_FORMAT_BGR|PNG_FORMAT_FLAG_ALPHA) 2828 #define PNG_FORMAT_ABGR (PNG_FORMAT_BGRA|PNG_FORMAT_FLAG_AFIRST) 2829 2830 /* Then the linear 2-byte formats. When naming these "Y" is used to 2831 * indicate a luminance (gray) channel. 2832 */ 2833 #define PNG_FORMAT_LINEAR_Y PNG_FORMAT_FLAG_LINEAR 2834 #define PNG_FORMAT_LINEAR_Y_ALPHA (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_ALPHA) 2835 #define PNG_FORMAT_LINEAR_RGB (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR) 2836 #define PNG_FORMAT_LINEAR_RGB_ALPHA \ 2837 (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_ALPHA) 2838 2839 /* With color-mapped formats the image data is one byte for each pixel, the byte 2840 * is an index into the color-map which is formatted as above. To obtain a 2841 * color-mapped format it is sufficient just to add the PNG_FOMAT_FLAG_COLORMAP 2842 * to one of the above definitions, or you can use one of the definitions below. 2843 */ 2844 #define PNG_FORMAT_RGB_COLORMAP (PNG_FORMAT_RGB|PNG_FORMAT_FLAG_COLORMAP) 2845 #define PNG_FORMAT_BGR_COLORMAP (PNG_FORMAT_BGR|PNG_FORMAT_FLAG_COLORMAP) 2846 #define PNG_FORMAT_RGBA_COLORMAP (PNG_FORMAT_RGBA|PNG_FORMAT_FLAG_COLORMAP) 2847 #define PNG_FORMAT_ARGB_COLORMAP (PNG_FORMAT_ARGB|PNG_FORMAT_FLAG_COLORMAP) 2848 #define PNG_FORMAT_BGRA_COLORMAP (PNG_FORMAT_BGRA|PNG_FORMAT_FLAG_COLORMAP) 2849 #define PNG_FORMAT_ABGR_COLORMAP (PNG_FORMAT_ABGR|PNG_FORMAT_FLAG_COLORMAP) 2850 2851 /* PNG_IMAGE macros 2852 * 2853 * These are convenience macros to derive information from a png_image 2854 * structure. The PNG_IMAGE_SAMPLE_ macros return values appropriate to the 2855 * actual image sample values - either the entries in the color-map or the 2856 * pixels in the image. The PNG_IMAGE_PIXEL_ macros return corresponding values 2857 * for the pixels and will always return 1 for color-mapped formats. The 2858 * remaining macros return information about the rows in the image and the 2859 * complete image. 2860 * 2861 * NOTE: All the macros that take a png_image::format parameter are compile time 2862 * constants if the format parameter is, itself, a constant. Therefore these 2863 * macros can be used in array declarations and case labels where required. 2864 * Similarly the macros are also pre-processor constants (sizeof is not used) so 2865 * they can be used in #if tests. 2866 * 2867 * First the information about the samples. 2868 */ 2869 #define PNG_IMAGE_SAMPLE_CHANNELS(fmt)\ 2870 (((fmt)&(PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_ALPHA))+1) 2871 /* Return the total number of channels in a given format: 1..4 */ 2872 2873 #define PNG_IMAGE_SAMPLE_COMPONENT_SIZE(fmt)\ 2874 ((((fmt) & PNG_FORMAT_FLAG_LINEAR) >> 2)+1) 2875 /* Return the size in bytes of a single component of a pixel or color-map 2876 * entry (as appropriate) in the image: 1 or 2. 2877 */ 2878 2879 #define PNG_IMAGE_SAMPLE_SIZE(fmt)\ 2880 (PNG_IMAGE_SAMPLE_CHANNELS(fmt) * PNG_IMAGE_SAMPLE_COMPONENT_SIZE(fmt)) 2881 /* This is the size of the sample data for one sample. If the image is 2882 * color-mapped it is the size of one color-map entry (and image pixels are 2883 * one byte in size), otherwise it is the size of one image pixel. 2884 */ 2885 2886 #define PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(fmt)\ 2887 (PNG_IMAGE_SAMPLE_CHANNELS(fmt) * 256) 2888 /* The maximum size of the color-map required by the format expressed in a 2889 * count of components. This can be used to compile-time allocate a 2890 * color-map: 2891 * 2892 * png_uint_16 colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(linear_fmt)]; 2893 * 2894 * png_byte colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(sRGB_fmt)]; 2895 * 2896 * Alternatively use the PNG_IMAGE_COLORMAP_SIZE macro below to use the 2897 * information from one of the png_image_begin_read_ APIs and dynamically 2898 * allocate the required memory. 2899 */ 2900 2901 /* Corresponding information about the pixels */ 2902 #define PNG_IMAGE_PIXEL_(test,fmt)\ 2903 (((fmt)&PNG_FORMAT_FLAG_COLORMAP)?1:test(fmt)) 2904 2905 #define PNG_IMAGE_PIXEL_CHANNELS(fmt)\ 2906 PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_CHANNELS,fmt) 2907 /* The number of separate channels (components) in a pixel; 1 for a 2908 * color-mapped image. 2909 */ 2910 2911 #define PNG_IMAGE_PIXEL_COMPONENT_SIZE(fmt)\ 2912 PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_COMPONENT_SIZE,fmt) 2913 /* The size, in bytes, of each component in a pixel; 1 for a color-mapped 2914 * image. 2915 */ 2916 2917 #define PNG_IMAGE_PIXEL_SIZE(fmt) PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_SIZE,fmt) 2918 /* The size, in bytes, of a complete pixel; 1 for a color-mapped image. */ 2919 2920 /* Information about the whole row, or whole image */ 2921 #define PNG_IMAGE_ROW_STRIDE(image)\ 2922 (PNG_IMAGE_PIXEL_CHANNELS((image).format) * (image).width) 2923 /* Return the total number of components in a single row of the image; this 2924 * is the minimum 'row stride', the minimum count of components between each 2925 * row. For a color-mapped image this is the minimum number of bytes in a 2926 * row. 2927 * 2928 * WARNING: this macro overflows for some images with more than one component 2929 * and very large image widths. libpng will refuse to process an image where 2930 * this macro would overflow. 2931 */ 2932 2933 #define PNG_IMAGE_BUFFER_SIZE(image, row_stride)\ 2934 (PNG_IMAGE_PIXEL_COMPONENT_SIZE((image).format)*(image).height*(row_stride)) 2935 /* Return the size, in bytes, of an image buffer given a png_image and a row 2936 * stride - the number of components to leave space for in each row. 2937 * 2938 * WARNING: this macro overflows a 32-bit integer for some large PNG images, 2939 * libpng will refuse to process an image where such an overflow would occur. 2940 */ 2941 2942 #define PNG_IMAGE_SIZE(image)\ 2943 PNG_IMAGE_BUFFER_SIZE(image, PNG_IMAGE_ROW_STRIDE(image)) 2944 /* Return the size, in bytes, of the image in memory given just a png_image; 2945 * the row stride is the minimum stride required for the image. 2946 */ 2947 2948 #define PNG_IMAGE_COLORMAP_SIZE(image)\ 2949 (PNG_IMAGE_SAMPLE_SIZE((image).format) * (image).colormap_entries) 2950 /* Return the size, in bytes, of the color-map of this image. If the image 2951 * format is not a color-map format this will return a size sufficient for 2952 * 256 entries in the given format; check PNG_FORMAT_FLAG_COLORMAP if 2953 * you don't want to allocate a color-map in this case. 2954 */ 2955 2956 /* PNG_IMAGE_FLAG_* 2957 * 2958 * Flags containing additional information about the image are held in the 2959 * 'flags' field of png_image. 2960 */ 2961 #define PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB 0x01 2962 /* This indicates the the RGB values of the in-memory bitmap do not 2963 * correspond to the red, green and blue end-points defined by sRGB. 2964 */ 2965 2966 #define PNG_IMAGE_FLAG_FAST 0x02 2967 /* On write emphasise speed over compression; the resultant PNG file will be 2968 * larger but will be produced significantly faster, particular for large 2969 * images. Do not use this option for images which will be distributed, only 2970 * used it when producing intermediate files that will be read back in 2971 * repeatedly. For a typical 24-bit image the option will double the read 2972 * speed at the cost of increasing the image size by 25%, however for many 2973 * more compressible images the PNG file can be 10 times larger with only a 2974 * slight speed gain. 2975 */ 2976 2977 #define PNG_IMAGE_FLAG_16BIT_sRGB 0x04 2978 /* On read if the image is a 16-bit per component image and there is no gAMA 2979 * or sRGB chunk assume that the components are sRGB encoded. Notice that 2980 * images output by the simplified API always have gamma information; setting 2981 * this flag only affects the interpretation of 16-bit images from an 2982 * external source. It is recommended that the application expose this flag 2983 * to the user; the user can normally easily recognize the difference between 2984 * linear and sRGB encoding. This flag has no effect on write - the data 2985 * passed to the write APIs must have the correct encoding (as defined 2986 * above.) 2987 * 2988 * If the flag is not set (the default) input 16-bit per component data is 2989 * assumed to be linear. 2990 * 2991 * NOTE: the flag can only be set after the png_image_begin_read_ call, 2992 * because that call initializes the 'flags' field. 2993 */ 2994 2995 #ifdef PNG_SIMPLIFIED_READ_SUPPORTED 2996 /* READ APIs 2997 * --------- 2998 * 2999 * The png_image passed to the read APIs must have been initialized by setting 3000 * the png_controlp field 'opaque' to NULL (or, safer, memset the whole thing.) 3001 */ 3002 #ifdef PNG_STDIO_SUPPORTED 3003 PNG_EXPORT(234, int, png_image_begin_read_from_file, (png_imagep image, 3004 const char *file_name)); 3005 /* The named file is opened for read and the image header is filled in 3006 * from the PNG header in the file. 3007 */ 3008 3009 PNG_EXPORT(235, int, png_image_begin_read_from_stdio, (png_imagep image, 3010 FILE* file)); 3011 /* The PNG header is read from the stdio FILE object. */ 3012 #endif /* STDIO */ 3013 3014 PNG_EXPORT(236, int, png_image_begin_read_from_memory, (png_imagep image, 3015 png_const_voidp memory, png_size_t size)); 3016 /* The PNG header is read from the given memory buffer. */ 3017 3018 PNG_EXPORT(237, int, png_image_finish_read, (png_imagep image, 3019 png_const_colorp background, void *buffer, png_int_32 row_stride, 3020 void *colormap)); 3021 /* Finish reading the image into the supplied buffer and clean up the 3022 * png_image structure. 3023 * 3024 * row_stride is the step, in byte or 2-byte units as appropriate, 3025 * between adjacent rows. A positive stride indicates that the top-most row 3026 * is first in the buffer - the normal top-down arrangement. A negative 3027 * stride indicates that the bottom-most row is first in the buffer. 3028 * 3029 * background need only be supplied if an alpha channel must be removed from 3030 * a png_byte format and the removal is to be done by compositing on a solid 3031 * color; otherwise it may be NULL and any composition will be done directly 3032 * onto the buffer. The value is an sRGB color to use for the background, 3033 * for grayscale output the green channel is used. 3034 * 3035 * background must be supplied when an alpha channel must be removed from a 3036 * single byte color-mapped output format, in other words if: 3037 * 3038 * 1) The original format from png_image_begin_read_from_* had 3039 * PNG_FORMAT_FLAG_ALPHA set. 3040 * 2) The format set by the application does not. 3041 * 3) The format set by the application has PNG_FORMAT_FLAG_COLORMAP set and 3042 * PNG_FORMAT_FLAG_LINEAR *not* set. 3043 * 3044 * For linear output removing the alpha channel is always done by compositing 3045 * on black and background is ignored. 3046 * 3047 * colormap must be supplied when PNG_FORMAT_FLAG_COLORMAP is set. It must 3048 * be at least the size (in bytes) returned by PNG_IMAGE_COLORMAP_SIZE. 3049 * image->colormap_entries will be updated to the actual number of entries 3050 * written to the colormap; this may be less than the original value. 3051 */ 3052 3053 PNG_EXPORT(238, void, png_image_free, (png_imagep image)); 3054 /* Free any data allocated by libpng in image->opaque, setting the pointer to 3055 * NULL. May be called at any time after the structure is initialized. 3056 */ 3057 #endif /* SIMPLIFIED_READ */ 3058 3059 #ifdef PNG_SIMPLIFIED_WRITE_SUPPORTED 3060 /* WRITE APIS 3061 * ---------- 3062 * For write you must initialize a png_image structure to describe the image to 3063 * be written. To do this use memset to set the whole structure to 0 then 3064 * initialize fields describing your image. 3065 * 3066 * version: must be set to PNG_IMAGE_VERSION 3067 * opaque: must be initialized to NULL 3068 * width: image width in pixels 3069 * height: image height in rows 3070 * format: the format of the data (image and color-map) you wish to write 3071 * flags: set to 0 unless one of the defined flags applies; set 3072 * PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB for color format images where the RGB 3073 * values do not correspond to the colors in sRGB. 3074 * colormap_entries: set to the number of entries in the color-map (0 to 256) 3075 */ 3076 #ifdef PNG_SIMPLIFIED_WRITE_STDIO_SUPPORTED 3077 PNG_EXPORT(239, int, png_image_write_to_file, (png_imagep image, 3078 const char *file, int convert_to_8bit, const void *buffer, 3079 png_int_32 row_stride, const void *colormap)); 3080 /* Write the image to the named file. */ 3081 3082 PNG_EXPORT(240, int, png_image_write_to_stdio, (png_imagep image, FILE *file, 3083 int convert_to_8_bit, const void *buffer, png_int_32 row_stride, 3084 const void *colormap)); 3085 /* Write the image to the given (FILE*). */ 3086 #endif /* SIMPLIFIED_WRITE_STDIO */ 3087 3088 /* With all write APIs if image is in one of the linear formats with 16-bit 3089 * data then setting convert_to_8_bit will cause the output to be an 8-bit PNG 3090 * gamma encoded according to the sRGB specification, otherwise a 16-bit linear 3091 * encoded PNG file is written. 3092 * 3093 * With color-mapped data formats the colormap parameter point to a color-map 3094 * with at least image->colormap_entries encoded in the specified format. If 3095 * the format is linear the written PNG color-map will be converted to sRGB 3096 * regardless of the convert_to_8_bit flag. 3097 * 3098 * With all APIs row_stride is handled as in the read APIs - it is the spacing 3099 * from one row to the next in component sized units (1 or 2 bytes) and if 3100 * negative indicates a bottom-up row layout in the buffer. If row_stride is 3101 * zero, libpng will calculate it for you from the image width and number of 3102 * channels. 3103 * 3104 * Note that the write API does not support interlacing, sub-8-bit pixels or 3105 * most ancillary chunks. If you need to write text chunks (e.g. for copyright 3106 * notices) you need to use one of the other APIs. 3107 */ 3108 3109 PNG_EXPORT(245, int, png_image_write_to_memory, (png_imagep image, void *memory, 3110 png_alloc_size_t * PNG_RESTRICT memory_bytes, int convert_to_8_bit, 3111 const void *buffer, png_int_32 row_stride, const void *colormap)); 3112 /* Write the image to the given memory buffer. The function both writes the 3113 * whole PNG data stream to *memory and updates *memory_bytes with the count 3114 * of bytes written. 3115 * 3116 * 'memory' may be NULL. In this case *memory_bytes is not read however on 3117 * success the number of bytes which would have been written will still be 3118 * stored in *memory_bytes. On failure *memory_bytes will contain 0. 3119 * 3120 * If 'memory' is not NULL it must point to memory[*memory_bytes] of 3121 * writeable memory. 3122 * 3123 * If the function returns success memory[*memory_bytes] (if 'memory' is not 3124 * NULL) contains the written PNG data. *memory_bytes will always be less 3125 * than or equal to the original value. 3126 * 3127 * If the function returns false and *memory_bytes was not changed an error 3128 * occured during write. If *memory_bytes was changed, or is not 0 if 3129 * 'memory' was NULL, the write would have succeeded but for the memory 3130 * buffer being too small. *memory_bytes contains the required number of 3131 * bytes and will be bigger that the original value. 3132 */ 3133 3134 #define png_image_write_get_memory_size(image, size, convert_to_8_bit, buffer,\ 3135 row_stride, colormap)\ 3136 png_image_write_to_memory(&(image), 0, &(size), convert_to_8_bit, buffer,\ 3137 row_stride, colormap) 3138 /* Return the amount of memory in 'size' required to compress this image. 3139 * The png_image structure 'image' must be filled in as in the above 3140 * function and must not be changed before the actual write call, the buffer 3141 * and all other parameters must also be identical to that in the final 3142 * write call. The 'size' variable need not be initialized. 3143 * 3144 * NOTE: the macro returns true/false, if false is returned 'size' will be 3145 * set to zero and the write failed and probably will fail if tried again. 3146 */ 3147 3148 /* You can pre-allocate the buffer by making sure it is of sufficient size 3149 * regardless of the amount of compression achieved. The buffer size will 3150 * always be bigger than the original image and it will never be filled. The 3151 * following macros are provided to assist in allocating the buffer. 3152 */ 3153 #define PNG_IMAGE_DATA_SIZE(image) (PNG_IMAGE_SIZE(image)+(image).height) 3154 /* The number of uncompressed bytes in the PNG byte encoding of the image; 3155 * uncompressing the PNG IDAT data will give this number of bytes. 3156 * 3157 * NOTE: while PNG_IMAGE_SIZE cannot overflow for an image in memory this 3158 * macro can because of the extra bytes used in the PNG byte encoding. You 3159 * need to avoid this macro if your image size approaches 2^30 in width or 3160 * height. The same goes for the remainder of these macros; they all produce 3161 * bigger numbers than the actual in-memory image size. 3162 */ 3163 #ifndef PNG_ZLIB_MAX_SIZE 3164 # define PNG_ZLIB_MAX_SIZE(b) ((b)+(((b)+7U)>>3)+(((b)+63U)>>6)+11U) 3165 /* An upper bound on the number of compressed bytes given 'b' uncompressed 3166 * bytes. This is based on deflateBounds() in zlib; different 3167 * implementations of zlib compression may conceivably produce more data so 3168 * if your zlib implementation is not zlib itself redefine this macro 3169 * appropriately. 3170 */ 3171 #endif 3172 3173 #define PNG_IMAGE_COMPRESSED_SIZE_MAX(image)\ 3174 PNG_ZLIB_MAX_SIZE((png_alloc_size_t)PNG_IMAGE_DATA_SIZE(image)) 3175 /* An upper bound on the size of the data in the PNG IDAT chunks. */ 3176 3177 #define PNG_IMAGE_PNG_SIZE_MAX_(image, image_size)\ 3178 ((8U/*sig*/+25U/*IHDR*/+16U/*gAMA*/+44U/*cHRM*/+12U/*IEND*/+\ 3179 (((image).format&PNG_FORMAT_FLAG_COLORMAP)?/*colormap: PLTE, tRNS*/\ 3180 12U+3U*(image).colormap_entries/*PLTE data*/+\ 3181 (((image).format&PNG_FORMAT_FLAG_ALPHA)?\ 3182 12U/*tRNS*/+(image).colormap_entries:0U):0U)+\ 3183 12U)+(12U*((image_size)/PNG_ZBUF_SIZE))/*IDAT*/+(image_size)) 3184 /* A helper for the following macro; if your compiler cannot handle the 3185 * following macro use this one with the result of 3186 * PNG_IMAGE_COMPRESSED_SIZE_MAX(image) as the second argument (most 3187 * compilers should handle this just fine.) 3188 */ 3189 3190 #define PNG_IMAGE_PNG_SIZE_MAX(image)\ 3191 PNG_IMAGE_PNG_SIZE_MAX_(image, PNG_IMAGE_COMPRESSED_SIZE_MAX(image)) 3192 /* An upper bound on the total length of the PNG data stream for 'image'. 3193 * The result is of type png_alloc_size_t, on 32-bit systems this may 3194 * overflow even though PNG_IMAGE_DATA_SIZE does not overflow; the write will 3195 * run out of buffer space but return a corrected size which should work. 3196 */ 3197 #endif /* SIMPLIFIED_WRITE */ 3198 /******************************************************************************* 3199 * END OF SIMPLIFIED API 3200 ******************************************************************************/ 3201 #endif /* SIMPLIFIED_{READ|WRITE} */ 3202 3203 /******************************************************************************* 3204 * Section 6: IMPLEMENTATION OPTIONS 3205 ******************************************************************************* 3206 * 3207 * Support for arbitrary implementation-specific optimizations. The API allows 3208 * particular options to be turned on or off. 'Option' is the number of the 3209 * option and 'onoff' is 0 (off) or non-0 (on). The value returned is given 3210 * by the PNG_OPTION_ defines below. 3211 * 3212 * HARDWARE: normally hardware capabilites, such as the Intel SSE instructions, 3213 * are detected at run time, however sometimes it may be impossible 3214 * to do this in user mode, in which case it is necessary to discover 3215 * the capabilities in an OS specific way. Such capabilities are 3216 * listed here when libpng has support for them and must be turned 3217 * ON by the application if present. 3218 * 3219 * SOFTWARE: sometimes software optimizations actually result in performance 3220 * decrease on some architectures or systems, or with some sets of 3221 * PNG images. 'Software' options allow such optimizations to be 3222 * selected at run time. 3223 */ 3224 #ifdef PNG_SET_OPTION_SUPPORTED 3225 #ifdef PNG_ARM_NEON_API_SUPPORTED 3226 # define PNG_ARM_NEON 0 /* HARDWARE: ARM Neon SIMD instructions supported */ 3227 #endif 3228 #define PNG_MAXIMUM_INFLATE_WINDOW 2 /* SOFTWARE: force maximum window */ 3229 #define PNG_SKIP_sRGB_CHECK_PROFILE 4 /* SOFTWARE: Check ICC profile for sRGB */ 3230 #ifdef PNG_MIPS_MSA_API_SUPPORTED 3231 # define PNG_MIPS_MSA 6 /* HARDWARE: MIPS Msa SIMD instructions supported */ 3232 #endif 3233 #define PNG_OPTION_NEXT 8 /* Next option - numbers must be even */ 3234 3235 /* Return values: NOTE: there are four values and 'off' is *not* zero */ 3236 #define PNG_OPTION_UNSET 0 /* Unset - defaults to off */ 3237 #define PNG_OPTION_INVALID 1 /* Option number out of range */ 3238 #define PNG_OPTION_OFF 2 3239 #define PNG_OPTION_ON 3 3240 3241 PNG_EXPORT(244, int, png_set_option, (png_structrp png_ptr, int option, 3242 int onoff)); 3243 #endif /* SET_OPTION */ 3244 3245 /******************************************************************************* 3246 * END OF HARDWARE AND SOFTWARE OPTIONS 3247 ******************************************************************************/ 3248 3249 /* Maintainer: Put new public prototypes here ^, in libpng.3, in project 3250 * defs, and in scripts/symbols.def. 3251 */ 3252 3253 /* The last ordinal number (this is the *last* one already used; the next 3254 * one to use is one more than this.) 3255 */ 3256 #ifdef PNG_EXPORT_LAST_ORDINAL 3257 PNG_EXPORT_LAST_ORDINAL(245); 3258 #endif 3259 3260 #ifdef __cplusplus 3261 } 3262 #endif 3263 3264 #endif /* PNG_VERSION_INFO_ONLY */ 3265 /* Do not put anything past this line */ 3266 #endif /* PNG_H */ 3267
