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