| 1 |   |
| 2 | /* png.h - header file for PNG reference library  |
| 3 | *  |
| 4 | * libpng version 1.6.37 - April 14, 2019  |
| 5 | *  |
| 6 | * Copyright (c) 2018-2019 Cosmin Truta  |
| 7 | * Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson  |
| 8 | * Copyright (c) 1996-1997 Andreas Dilger  |
| 9 | * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.  |
| 10 | *  |
| 11 | * This code is released under the libpng license. (See LICENSE, below.)  |
| 12 | *  |
| 13 | * Authors and maintainers:  |
| 14 | * libpng versions 0.71, May 1995, through 0.88, January 1996: Guy Schalnat  |
| 15 | * libpng versions 0.89, June 1996, through 0.96, May 1997: Andreas Dilger  |
| 16 | * libpng versions 0.97, January 1998, through 1.6.35, July 2018:  |
| 17 | * Glenn Randers-Pehrson  |
| 18 | * libpng versions 1.6.36, December 2018, through 1.6.37, April 2019:  |
| 19 | * Cosmin Truta  |
| 20 | * See also "Contributing Authors", below.  |
| 21 | */  |
| 22 |   |
| 23 | /*  |
| 24 | * COPYRIGHT NOTICE, DISCLAIMER, and LICENSE  |
| 25 | * =========================================  |
| 26 | *  |
| 27 | * PNG Reference Library License version 2  |
| 28 | * ---------------------------------------  |
| 29 | *  |
| 30 | * * Copyright (c) 1995-2019 The PNG Reference Library Authors.  |
| 31 | * * Copyright (c) 2018-2019 Cosmin Truta.  |
| 32 | * * Copyright (c) 2000-2002, 2004, 2006-2018 Glenn Randers-Pehrson.  |
| 33 | * * Copyright (c) 1996-1997 Andreas Dilger.  |
| 34 | * * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.  |
| 35 | *  |
| 36 | * The software is supplied "as is", without warranty of any kind,  |
| 37 | * express or implied, including, without limitation, the warranties  |
| 38 | * of merchantability, fitness for a particular purpose, title, and  |
| 39 | * non-infringement. In no event shall the Copyright owners, or  |
| 40 | * anyone distributing the software, be liable for any damages or  |
| 41 | * other liability, whether in contract, tort or otherwise, arising  |
| 42 | * from, out of, or in connection with the software, or the use or  |
| 43 | * other dealings in the software, even if advised of the possibility  |
| 44 | * of such damage.  |
| 45 | *  |
| 46 | * Permission is hereby granted to use, copy, modify, and distribute  |
| 47 | * this software, or portions hereof, for any purpose, without fee,  |
| 48 | * subject to the following restrictions:  |
| 49 | *  |
| 50 | * 1. The origin of this software must not be misrepresented; you  |
| 51 | * must not claim that you wrote the original software. If you  |
| 52 | * use this software in a product, an acknowledgment in the product  |
| 53 | * documentation would be appreciated, but is not required.  |
| 54 | *  |
| 55 | * 2. Altered source versions must be plainly marked as such, and must  |
| 56 | * not be misrepresented as being the original software.  |
| 57 | *  |
| 58 | * 3. This Copyright notice may not be removed or altered from any  |
| 59 | * source or altered source distribution.  |
| 60 | *  |
| 61 | *  |
| 62 | * PNG Reference Library License version 1 (for libpng 0.5 through 1.6.35)  |
| 63 | * -----------------------------------------------------------------------  |
| 64 | *  |
| 65 | * libpng versions 1.0.7, July 1, 2000, through 1.6.35, July 15, 2018 are  |
| 66 | * Copyright (c) 2000-2002, 2004, 2006-2018 Glenn Randers-Pehrson, are  |
| 67 | * derived from libpng-1.0.6, and are distributed according to the same  |
| 68 | * disclaimer and license as libpng-1.0.6 with the following individuals  |
| 69 | * added to the list of Contributing Authors:  |
| 70 | *  |
| 71 | * Simon-Pierre Cadieux  |
| 72 | * Eric S. Raymond  |
| 73 | * Mans Rullgard  |
| 74 | * Cosmin Truta  |
| 75 | * Gilles Vollant  |
| 76 | * James Yu  |
| 77 | * Mandar Sahastrabuddhe  |
| 78 | * Google Inc.  |
| 79 | * Vadim Barkov  |
| 80 | *  |
| 81 | * and with the following additions to the disclaimer:  |
| 82 | *  |
| 83 | * There is no warranty against interference with your enjoyment of  |
| 84 | * the library or against infringement. There is no warranty that our  |
| 85 | * efforts or the library will fulfill any of your particular purposes  |
| 86 | * or needs. This library is provided with all faults, and the entire  |
| 87 | * risk of satisfactory quality, performance, accuracy, and effort is  |
| 88 | * with the user.  |
| 89 | *  |
| 90 | * Some files in the "contrib" directory and some configure-generated  |
| 91 | * files that are distributed with libpng have other copyright owners, and  |
| 92 | * are released under other open source licenses.  |
| 93 | *  |
| 94 | * libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are  |
| 95 | * Copyright (c) 1998-2000 Glenn Randers-Pehrson, are derived from  |
| 96 | * libpng-0.96, and are distributed according to the same disclaimer and  |
| 97 | * license as libpng-0.96, with the following individuals added to the  |
| 98 | * list of Contributing Authors:  |
| 99 | *  |
| 100 | * Tom Lane  |
| 101 | * Glenn Randers-Pehrson  |
| 102 | * Willem van Schaik  |
| 103 | *  |
| 104 | * libpng versions 0.89, June 1996, through 0.96, May 1997, are  |
| 105 | * Copyright (c) 1996-1997 Andreas Dilger, are derived from libpng-0.88,  |
| 106 | * and are distributed according to the same disclaimer and license as  |
| 107 | * libpng-0.88, with the following individuals added to the list of  |
| 108 | * Contributing Authors:  |
| 109 | *  |
| 110 | * John Bowler  |
| 111 | * Kevin Bracey  |
| 112 | * Sam Bushell  |
| 113 | * Magnus Holmgren  |
| 114 | * Greg Roelofs  |
| 115 | * Tom Tanner  |
| 116 | *  |
| 117 | * Some files in the "scripts" directory have other copyright owners,  |
| 118 | * but are released under this license.  |
| 119 | *  |
| 120 | * libpng versions 0.5, May 1995, through 0.88, January 1996, are  |
| 121 | * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.  |
| 122 | *  |
| 123 | * For the purposes of this copyright and license, "Contributing Authors"  |
| 124 | * is defined as the following set of individuals:  |
| 125 | *  |
| 126 | * Andreas Dilger  |
| 127 | * Dave Martindale  |
| 128 | * Guy Eric Schalnat  |
| 129 | * Paul Schmidt  |
| 130 | * Tim Wegner  |
| 131 | *  |
| 132 | * The PNG Reference Library is supplied "AS IS". The Contributing  |
| 133 | * Authors and Group 42, Inc. disclaim all warranties, expressed or  |
| 134 | * implied, including, without limitation, the warranties of  |
| 135 | * merchantability and of fitness for any purpose. The Contributing  |
| 136 | * Authors and Group 42, Inc. assume no liability for direct, indirect,  |
| 137 | * incidental, special, exemplary, or consequential damages, which may  |
| 138 | * result from the use of the PNG Reference Library, even if advised of  |
| 139 | * the possibility of such damage.  |
| 140 | *  |
| 141 | * Permission is hereby granted to use, copy, modify, and distribute this  |
| 142 | * source code, or portions hereof, for any purpose, without fee, subject  |
| 143 | * to the following restrictions:  |
| 144 | *  |
| 145 | * 1. The origin of this source code must not be misrepresented.  |
| 146 | *  |
| 147 | * 2. Altered versions must be plainly marked as such and must not  |
| 148 | * be misrepresented as being the original source.  |
| 149 | *  |
| 150 | * 3. This Copyright notice may not be removed or altered from any  |
| 151 | * source or altered source distribution.  |
| 152 | *  |
| 153 | * The Contributing Authors and Group 42, Inc. specifically permit,  |
| 154 | * without fee, and encourage the use of this source code as a component  |
| 155 | * to supporting the PNG file format in commercial products. If you use  |
| 156 | * this source code in a product, acknowledgment is not required but would  |
| 157 | * be appreciated.  |
| 158 | *  |
| 159 | * END OF COPYRIGHT NOTICE, DISCLAIMER, and LICENSE.  |
| 160 | *  |
| 161 | * TRADEMARK  |
| 162 | * =========  |
| 163 | *  |
| 164 | * The name "libpng" has not been registered by the Copyright owners  |
| 165 | * as a trademark in any jurisdiction. However, because libpng has  |
| 166 | * been distributed and maintained world-wide, continually since 1995,  |
| 167 | * the Copyright owners claim "common-law trademark protection" in any  |
| 168 | * jurisdiction where common-law trademark is recognized.  |
| 169 | */  |
| 170 |   |
| 171 | /*  |
| 172 | * A "png_get_copyright" function is available, for convenient use in "about"  |
| 173 | * boxes and the like:  |
| 174 | *  |
| 175 | * printf("%s", png_get_copyright(NULL));  |
| 176 | *  |
| 177 | * Also, the PNG logo (in PNG format, of course) is supplied in the  |
| 178 | * files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31).  |
| 179 | */  |
| 180 |   |
| 181 | /*  |
| 182 | * The contributing authors would like to thank all those who helped  |
| 183 | * with testing, bug fixes, and patience. This wouldn't have been  |
| 184 | * possible without all of you.  |
| 185 | *  |
| 186 | * Thanks to Frank J. T. Wojcik for helping with the documentation.  |
| 187 | */  |
| 188 |   |
| 189 | /* Note about libpng version numbers:  |
| 190 | *  |
| 191 | * Due to various miscommunications, unforeseen code incompatibilities  |
| 192 | * and occasional factors outside the authors' control, version numbering  |
| 193 | * on the library has not always been consistent and straightforward.  |
| 194 | * The following table summarizes matters since version 0.89c, which was  |
| 195 | * the first widely used release:  |
| 196 | *  |
| 197 | * source png.h png.h shared-lib  |
| 198 | * version string int version  |
| 199 | * ------- ------ ----- ----------  |
| 200 | * 0.89c "1.0 beta 3" 0.89 89 1.0.89  |
| 201 | * 0.90 "1.0 beta 4" 0.90 90 0.90 [should have been 2.0.90]  |
| 202 | * 0.95 "1.0 beta 5" 0.95 95 0.95 [should have been 2.0.95]  |
| 203 | * 0.96 "1.0 beta 6" 0.96 96 0.96 [should have been 2.0.96]  |
| 204 | * 0.97b "1.00.97 beta 7" 1.00.97 97 1.0.1 [should have been 2.0.97]  |
| 205 | * 0.97c 0.97 97 2.0.97  |
| 206 | * 0.98 0.98 98 2.0.98  |
| 207 | * 0.99 0.99 98 2.0.99  |
| 208 | * 0.99a-m 0.99 99 2.0.99  |
| 209 | * 1.00 1.00 100 2.1.0 [100 should be 10000]  |
| 210 | * 1.0.0 (from here on, the 100 2.1.0 [100 should be 10000]  |
| 211 | * 1.0.1 png.h string is 10001 2.1.0  |
| 212 | * 1.0.1a-e identical to the 10002 from here on, the shared library  |
| 213 | * 1.0.2 source version) 10002 is 2.V where V is the source code  |
| 214 | * 1.0.2a-b 10003 version, except as noted.  |
| 215 | * 1.0.3 10003  |
| 216 | * 1.0.3a-d 10004  |
| 217 | * 1.0.4 10004  |
| 218 | * 1.0.4a-f 10005  |
| 219 | * 1.0.5 (+ 2 patches) 10005  |
| 220 | * 1.0.5a-d 10006  |
| 221 | * 1.0.5e-r 10100 (not source compatible)  |
| 222 | * 1.0.5s-v 10006 (not binary compatible)  |
| 223 | * 1.0.6 (+ 3 patches) 10006 (still binary incompatible)  |
| 224 | * 1.0.6d-f 10007 (still binary incompatible)  |
| 225 | * 1.0.6g 10007  |
| 226 | * 1.0.6h 10007 10.6h (testing xy.z so-numbering)  |
| 227 | * 1.0.6i 10007 10.6i  |
| 228 | * 1.0.6j 10007 2.1.0.6j (incompatible with 1.0.0)  |
| 229 | * 1.0.7beta11-14 DLLNUM 10007 2.1.0.7beta11-14 (binary compatible)  |
| 230 | * 1.0.7beta15-18 1 10007 2.1.0.7beta15-18 (binary compatible)  |
| 231 | * 1.0.7rc1-2 1 10007 2.1.0.7rc1-2 (binary compatible)  |
| 232 | * 1.0.7 1 10007 (still compatible)  |
| 233 | * ...  |
| 234 | * 1.0.69 10 10069 10.so.0.69[.0]  |
| 235 | * ...  |
| 236 | * 1.2.59 13 10259 12.so.0.59[.0]  |
| 237 | * ...  |
| 238 | * 1.4.20 14 10420 14.so.0.20[.0]  |
| 239 | * ...  |
| 240 | * 1.5.30 15 10530 15.so.15.30[.0]  |
| 241 | * ...  |
| 242 | * 1.6.37 16 10637 16.so.16.37[.0]  |
| 243 | *  |
| 244 | * Henceforth the source version will match the shared-library major and  |
| 245 | * minor numbers; the shared-library major version number will be used for  |
| 246 | * changes in backward compatibility, as it is intended.  |
| 247 | * The PNG_LIBPNG_VER macro, which is not used within libpng but is  |
| 248 | * available for applications, is an unsigned integer of the form XYYZZ  |
| 249 | * corresponding to the source version X.Y.Z (leading zeros in Y and Z).  |
| 250 | * Beta versions were given the previous public release number plus a  |
| 251 | * letter, until version 1.0.6j; from then on they were given the upcoming  |
| 252 | * public release number plus "betaNN" or "rcNN".  |
| 253 | *  |
| 254 | * Binary incompatibility exists only when applications make direct access  |
| 255 | * to the info_ptr or png_ptr members through png.h, and the compiled  |
| 256 | * application is loaded with a different version of the library.  |
| 257 | *  |
| 258 | * DLLNUM will change each time there are forward or backward changes  |
| 259 | * in binary compatibility (e.g., when a new feature is added).  |
| 260 | *  |
| 261 | * See libpng.txt or libpng.3 for more information. The PNG specification  |
| 262 | * is available as a W3C Recommendation and as an ISO/IEC Standard; see  |
| 263 | * <https://www.w3.org/TR/2003/REC-PNG-20031110/>  |
| 264 | */  |
| 265 |   |
| 266 | #ifndef PNG_H  |
| 267 | #define PNG_H  |
| 268 |   |
| 269 | /* This is not the place to learn how to use libpng. The file libpng-manual.txt  |
| 270 | * describes how to use libpng, and the file example.c summarizes it  |
| 271 | * with some code on which to build. This file is useful for looking  |
| 272 | * at the actual function definitions and structure components. If that  |
| 273 | * file has been stripped from your copy of libpng, you can find it at  |
| 274 | * <http://www.libpng.org/pub/png/libpng-manual.txt>  |
| 275 | *  |
| 276 | * If you just need to read a PNG file and don't want to read the documentation  |
| 277 | * skip to the end of this file and read the section entitled 'simplified API'.  |
| 278 | */  |
| 279 |   |
| 280 | /* Version information for png.h - this should match the version in png.c */  |
| 281 | #define PNG_LIBPNG_VER_STRING "1.6.37"  |
| 282 | #define " libpng version 1.6.37 - April 14, 2019\n"  |
| 283 |   |
| 284 | #define PNG_LIBPNG_VER_SONUM 16  |
| 285 | #define PNG_LIBPNG_VER_DLLNUM 16  |
| 286 |   |
| 287 | /* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */  |
| 288 | #define PNG_LIBPNG_VER_MAJOR 1  |
| 289 | #define PNG_LIBPNG_VER_MINOR 6  |
| 290 | #define PNG_LIBPNG_VER_RELEASE 37  |
| 291 |   |
| 292 | /* This should be zero for a public release, or non-zero for a  |
| 293 | * development version. [Deprecated]  |
| 294 | */  |
| 295 | #define PNG_LIBPNG_VER_BUILD 0  |
| 296 |   |
| 297 | /* Release Status */  |
| 298 | #define PNG_LIBPNG_BUILD_ALPHA 1  |
| 299 | #define PNG_LIBPNG_BUILD_BETA 2  |
| 300 | #define PNG_LIBPNG_BUILD_RC 3  |
| 301 | #define PNG_LIBPNG_BUILD_STABLE 4  |
| 302 | #define PNG_LIBPNG_BUILD_RELEASE_STATUS_MASK 7  |
| 303 |   |
| 304 | /* Release-Specific Flags */  |
| 305 | #define PNG_LIBPNG_BUILD_PATCH 8 /* Can be OR'ed with  |
| 306 | PNG_LIBPNG_BUILD_STABLE only */  |
| 307 | #define PNG_LIBPNG_BUILD_PRIVATE 16 /* Cannot be OR'ed with  |
| 308 | PNG_LIBPNG_BUILD_SPECIAL */  |
| 309 | #define PNG_LIBPNG_BUILD_SPECIAL 32 /* Cannot be OR'ed with  |
| 310 | PNG_LIBPNG_BUILD_PRIVATE */  |
| 311 |   |
| 312 | #define PNG_LIBPNG_BUILD_BASE_TYPE PNG_LIBPNG_BUILD_STABLE  |
| 313 |   |
| 314 | /* Careful here. At one time, Guy wanted to use 082, but that  |
| 315 | * would be octal. We must not include leading zeros.  |
| 316 | * Versions 0.7 through 1.0.0 were in the range 0 to 100 here  |
| 317 | * (only version 1.0.0 was mis-numbered 100 instead of 10000).  |
| 318 | * From version 1.0.1 it is:  |
| 319 | * XXYYZZ, where XX=major, YY=minor, ZZ=release  |
| 320 | */  |
| 321 | #define PNG_LIBPNG_VER 10637 /* 1.6.37 */  |
| 322 |   |
| 323 | /* Library configuration: these options cannot be changed after  |
| 324 | * the library has been built.  |
| 325 | */  |
| 326 | #ifndef PNGLCONF_H  |
| 327 | /* If pnglibconf.h is missing, you can  |
| 328 | * copy scripts/pnglibconf.h.prebuilt to pnglibconf.h  |
| 329 | */  |
| 330 | # include "pnglibconf.h"  |
| 331 | #endif  |
| 332 |   |
| 333 | #define PNG_APNG_SUPPORTED  |
| 334 | #define PNG_READ_APNG_SUPPORTED  |
| 335 | #define PNG_WRITE_APNG_SUPPORTED  |
| 336 |   |
| 337 | #ifndef PNG_VERSION_INFO_ONLY  |
| 338 | /* Machine specific configuration. */  |
| 339 | # include "pngconf.h"  |
| 340 | #endif  |
| 341 |   |
| 342 | /*  |
| 343 | * Added at libpng-1.2.8  |
| 344 | *  |
| 345 | * Ref MSDN: Private as priority over Special  |
| 346 | * VS_FF_PRIVATEBUILD File *was not* built using standard release  |
| 347 | * procedures. If this value is given, the StringFileInfo block must  |
| 348 | * contain a PrivateBuild string.  |
| 349 | *  |
| 350 | * VS_FF_SPECIALBUILD File *was* built by the original company using  |
| 351 | * standard release procedures but is a variation of the standard  |
| 352 | * file of the same version number. If this value is given, the  |
| 353 | * StringFileInfo block must contain a SpecialBuild string.  |
| 354 | */  |
| 355 |   |
| 356 | #ifdef PNG_USER_PRIVATEBUILD /* From pnglibconf.h */  |
| 357 | # define PNG_LIBPNG_BUILD_TYPE \  |
| 358 | (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_PRIVATE)  |
| 359 | #else  |
| 360 | # ifdef PNG_LIBPNG_SPECIALBUILD  |
| 361 | # define PNG_LIBPNG_BUILD_TYPE \  |
| 362 | (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_SPECIAL)  |
| 363 | # else  |
| 364 | # define PNG_LIBPNG_BUILD_TYPE (PNG_LIBPNG_BUILD_BASE_TYPE)  |
| 365 | # endif  |
| 366 | #endif  |
| 367 |   |
| 368 | #ifndef PNG_VERSION_INFO_ONLY  |
| 369 |   |
| 370 | /* Inhibit C++ name-mangling for libpng functions but not for system calls. */  |
| 371 | #ifdef __cplusplus  |
| 372 | extern "C" {  |
| 373 | #endif /* __cplusplus */  |
| 374 |   |
| 375 | /* Version information for C files, stored in png.c. This had better match  |
| 376 | * the version above.  |
| 377 | */  |
| 378 | #define png_libpng_ver png_get_header_ver(NULL)  |
| 379 |   |
| 380 | /* This file is arranged in several sections:  |
| 381 | *  |
| 382 | * 1. [omitted]  |
| 383 | * 2. Any configuration options that can be specified by for the application  |
| 384 | * code when it is built. (Build time configuration is in pnglibconf.h)  |
| 385 | * 3. Type definitions (base types are defined in pngconf.h), structure  |
| 386 | * definitions.  |
| 387 | * 4. Exported library functions.  |
| 388 | * 5. Simplified API.  |
| 389 | * 6. Implementation options.  |
| 390 | *  |
| 391 | * The library source code has additional files (principally pngpriv.h) that  |
| 392 | * allow configuration of the library.  |
| 393 | */  |
| 394 |   |
| 395 | /* Section 1: [omitted] */  |
| 396 |   |
| 397 | /* Section 2: run time configuration  |
| 398 | * See pnglibconf.h for build time configuration  |
| 399 | *  |
| 400 | * Run time configuration allows the application to choose between  |
| 401 | * implementations of certain arithmetic APIs. The default is set  |
| 402 | * at build time and recorded in pnglibconf.h, but it is safe to  |
| 403 | * override these (and only these) settings. Note that this won't  |
| 404 | * change what the library does, only application code, and the  |
| 405 | * settings can (and probably should) be made on a per-file basis  |
| 406 | * by setting the #defines before including png.h  |
| 407 | *  |
| 408 | * Use macros to read integers from PNG data or use the exported  |
| 409 | * functions?  |
| 410 | * PNG_USE_READ_MACROS: use the macros (see below) Note that  |
| 411 | * the macros evaluate their argument multiple times.  |
| 412 | * PNG_NO_USE_READ_MACROS: call the relevant library function.  |
| 413 | *  |
| 414 | * Use the alternative algorithm for compositing alpha samples that  |
| 415 | * does not use division?  |
| 416 | * PNG_READ_COMPOSITE_NODIV_SUPPORTED: use the 'no division'  |
| 417 | * algorithm.  |
| 418 | * PNG_NO_READ_COMPOSITE_NODIV: use the 'division' algorithm.  |
| 419 | *  |
| 420 | * How to handle benign errors if PNG_ALLOW_BENIGN_ERRORS is  |
| 421 | * false?  |
| 422 | * PNG_ALLOW_BENIGN_ERRORS: map calls to the benign error  |
| 423 | * APIs to png_warning.  |
| 424 | * Otherwise the calls are mapped to png_error.  |
| 425 | */  |
| 426 |   |
| 427 | /* Section 3: type definitions, including structures and compile time  |
| 428 | * constants.  |
| 429 | * See pngconf.h for base types that vary by machine/system  |
| 430 | */  |
| 431 |   |
| 432 | #ifdef PNG_APNG_SUPPORTED  |
| 433 | /* dispose_op flags from inside fcTL */  |
| 434 | #define PNG_DISPOSE_OP_NONE 0x00U  |
| 435 | #define PNG_DISPOSE_OP_BACKGROUND 0x01U  |
| 436 | #define PNG_DISPOSE_OP_PREVIOUS 0x02U  |
| 437 |   |
| 438 | /* blend_op flags from inside fcTL */  |
| 439 | #define PNG_BLEND_OP_SOURCE 0x00U  |
| 440 | #define PNG_BLEND_OP_OVER 0x01U  |
| 441 | #endif /* PNG_APNG_SUPPORTED */  |
| 442 |   |
| 443 | /* This triggers a compiler error in png.c, if png.c and png.h  |
| 444 | * do not agree upon the version number.  |
| 445 | */  |
| 446 | typedef char* png_libpng_version_1_6_37;  |
| 447 |   |
| 448 | /* Basic control structions. Read libpng-manual.txt or libpng.3 for more info.  |
| 449 | *  |
| 450 | * png_struct is the cache of information used while reading or writing a single  |
| 451 | * PNG file. One of these is always required, although the simplified API  |
| 452 | * (below) hides the creation and destruction of it.  |
| 453 | */  |
| 454 | typedef struct png_struct_def png_struct;  |
| 455 | typedef const png_struct * png_const_structp;  |
| 456 | typedef png_struct * png_structp;  |
| 457 | typedef png_struct * * png_structpp;  |
| 458 |   |
| 459 | /* png_info contains information read from or to be written to a PNG file. One  |
| 460 | * or more of these must exist while reading or creating a PNG file. The  |
| 461 | * information is not used by libpng during read but is used to control what  |
| 462 | * gets written when a PNG file is created. "png_get_" function calls read  |
| 463 | * information during read and "png_set_" functions calls write information  |
| 464 | * when creating a PNG.  |
| 465 | * been moved into a separate header file that is not accessible to  |
| 466 | * applications. Read libpng-manual.txt or libpng.3 for more info.  |
| 467 | */  |
| 468 | typedef struct png_info_def png_info;  |
| 469 | typedef png_info * png_infop;  |
| 470 | typedef const png_info * png_const_infop;  |
| 471 | typedef png_info * * png_infopp;  |
| 472 |   |
| 473 | /* Types with names ending 'p' are pointer types. The corresponding types with  |
| 474 | * names ending 'rp' are identical pointer types except that the pointer is  |
| 475 | * marked 'restrict', which means that it is the only pointer to the object  |
| 476 | * passed to the function. Applications should not use the 'restrict' types;  |
| 477 | * it is always valid to pass 'p' to a pointer with a function argument of the  |
| 478 | * corresponding 'rp' type. Different compilers have different rules with  |
| 479 | * regard to type matching in the presence of 'restrict'. For backward  |
| 480 | * compatibility libpng callbacks never have 'restrict' in their parameters and,  |
| 481 | * consequentially, writing portable application code is extremely difficult if  |
| 482 | * an attempt is made to use 'restrict'.  |
| 483 | */  |
| 484 | typedef png_struct * PNG_RESTRICT png_structrp;  |
| 485 | typedef const png_struct * PNG_RESTRICT png_const_structrp;  |
| 486 | typedef png_info * PNG_RESTRICT png_inforp;  |
| 487 | typedef const png_info * PNG_RESTRICT png_const_inforp;  |
| 488 |   |
| 489 | /* Three color definitions. The order of the red, green, and blue, (and the  |
| 490 | * exact size) is not important, although the size of the fields need to  |
| 491 | * be png_byte or png_uint_16 (as defined below).  |
| 492 | */  |
| 493 | typedef struct png_color_struct  |
| 494 | {  |
| 495 | png_byte red;  |
| 496 | png_byte green;  |
| 497 | png_byte blue;  |
| 498 | } png_color;  |
| 499 | typedef png_color * png_colorp;  |
| 500 | typedef const png_color * png_const_colorp;  |
| 501 | typedef png_color * * png_colorpp;  |
| 502 |   |
| 503 | typedef struct png_color_16_struct  |
| 504 | {  |
| 505 | png_byte index; /* used for palette files */  |
| 506 | png_uint_16 red; /* for use in red green blue files */  |
| 507 | png_uint_16 green;  |
| 508 | png_uint_16 blue;  |
| 509 | png_uint_16 gray; /* for use in grayscale files */  |
| 510 | } png_color_16;  |
| 511 | typedef png_color_16 * png_color_16p;  |
| 512 | typedef const png_color_16 * png_const_color_16p;  |
| 513 | typedef png_color_16 * * png_color_16pp;  |
| 514 |   |
| 515 | typedef struct png_color_8_struct  |
| 516 | {  |
| 517 | png_byte red; /* for use in red green blue files */  |
| 518 | png_byte green;  |
| 519 | png_byte blue;  |
| 520 | png_byte gray; /* for use in grayscale files */  |
| 521 | png_byte alpha; /* for alpha channel files */  |
| 522 | } png_color_8;  |
| 523 | typedef png_color_8 * png_color_8p;  |
| 524 | typedef const png_color_8 * png_const_color_8p;  |
| 525 | typedef png_color_8 * * png_color_8pp;  |
| 526 |   |
| 527 | /*  |
| 528 | * The following two structures are used for the in-core representation  |
| 529 | * of sPLT chunks.  |
| 530 | */  |
| 531 | typedef struct png_sPLT_entry_struct  |
| 532 | {  |
| 533 | png_uint_16 red;  |
| 534 | png_uint_16 green;  |
| 535 | png_uint_16 blue;  |
| 536 | png_uint_16 alpha;  |
| 537 | png_uint_16 frequency;  |
| 538 | } png_sPLT_entry;  |
| 539 | typedef png_sPLT_entry * png_sPLT_entryp;  |
| 540 | typedef const png_sPLT_entry * png_const_sPLT_entryp;  |
| 541 | typedef png_sPLT_entry * * png_sPLT_entrypp;  |
| 542 |   |
| 543 | /* When the depth of the sPLT palette is 8 bits, the color and alpha samples  |
| 544 | * occupy the LSB of their respective members, and the MSB of each member  |
| 545 | * is zero-filled. The frequency member always occupies the full 16 bits.  |
| 546 | */  |
| 547 |   |
| 548 | typedef struct png_sPLT_struct  |
| 549 | {  |
| 550 | png_charp name; /* palette name */  |
| 551 | png_byte depth; /* depth of palette samples */  |
| 552 | png_sPLT_entryp entries; /* palette entries */  |
| 553 | png_int_32 nentries; /* number of palette entries */  |
| 554 | } png_sPLT_t;  |
| 555 | typedef png_sPLT_t * png_sPLT_tp;  |
| 556 | typedef const png_sPLT_t * png_const_sPLT_tp;  |
| 557 | typedef png_sPLT_t * * png_sPLT_tpp;  |
| 558 |   |
| 559 | #ifdef PNG_TEXT_SUPPORTED  |
| 560 | /* png_text holds the contents of a text/ztxt/itxt chunk in a PNG file,  |
| 561 | * and whether that contents is compressed or not. The "key" field  |
| 562 | * points to a regular zero-terminated C string. The "text" fields can be a  |
| 563 | * regular C string, an empty string, or a NULL pointer.  |
| 564 | * However, the structure returned by png_get_text() will always contain  |
| 565 | * the "text" field as a regular zero-terminated C string (possibly  |
| 566 | * empty), never a NULL pointer, so it can be safely used in printf() and  |
| 567 | * other string-handling functions. Note that the "itxt_length", "lang", and  |
| 568 | * "lang_key" members of the structure only exist when the library is built  |
| 569 | * with iTXt chunk support. Prior to libpng-1.4.0 the library was built by  |
| 570 | * default without iTXt support. Also note that when iTXt *is* supported,  |
| 571 | * the "lang" and "lang_key" fields contain NULL pointers when the  |
| 572 | * "compression" field contains * PNG_TEXT_COMPRESSION_NONE or  |
| 573 | * PNG_TEXT_COMPRESSION_zTXt. Note that the "compression value" is not the  |
| 574 | * same as what appears in the PNG tEXt/zTXt/iTXt chunk's "compression flag"  |
| 575 | * which is always 0 or 1, or its "compression method" which is always 0.  |
| 576 | */  |
| 577 | typedef struct png_text_struct  |
| 578 | {  |
| 579 | int compression; /* compression value:  |
| 580 | -1: tEXt, none  |
| 581 | 0: zTXt, deflate  |
| 582 | 1: iTXt, none  |
| 583 | 2: iTXt, deflate */  |
| 584 | png_charp key; /* keyword, 1-79 character description of "text" */  |
| 585 | png_charp text; /* comment, may be an empty string (ie "")  |
| 586 | or a NULL pointer */  |
| 587 | size_t text_length; /* length of the text string */  |
| 588 | size_t itxt_length; /* length of the itxt string */  |
| 589 | png_charp lang; /* language code, 0-79 characters  |
| 590 | or a NULL pointer */  |
| 591 | png_charp lang_key; /* keyword translated UTF-8 string, 0 or more  |
| 592 | chars or a NULL pointer */  |
| 593 | } png_text;  |
| 594 | typedef png_text * png_textp;  |
| 595 | typedef const png_text * png_const_textp;  |
| 596 | typedef png_text * * png_textpp;  |
| 597 | #endif  |
| 598 |   |
| 599 | /* Supported compression types for text in PNG files (tEXt, and zTXt).  |
| 600 | * The values of the PNG_TEXT_COMPRESSION_ defines should NOT be changed. */  |
| 601 | #define PNG_TEXT_COMPRESSION_NONE_WR -3  |
| 602 | #define PNG_TEXT_COMPRESSION_zTXt_WR -2  |
| 603 | #define PNG_TEXT_COMPRESSION_NONE -1  |
| 604 | #define PNG_TEXT_COMPRESSION_zTXt 0  |
| 605 | #define PNG_ITXT_COMPRESSION_NONE 1  |
| 606 | #define PNG_ITXT_COMPRESSION_zTXt 2  |
| 607 | #define PNG_TEXT_COMPRESSION_LAST 3 /* Not a valid value */  |
| 608 |   |
| 609 | /* png_time is a way to hold the time in an machine independent way.  |
| 610 | * Two conversions are provided, both from time_t and struct tm. There  |
| 611 | * is no portable way to convert to either of these structures, as far  |
| 612 | * as I know. If you know of a portable way, send it to me. As a side  |
| 613 | * note - PNG has always been Year 2000 compliant!  |
| 614 | */  |
| 615 | typedef struct png_time_struct  |
| 616 | {  |
| 617 | png_uint_16 year; /* full year, as in, 1995 */  |
| 618 | png_byte month; /* month of year, 1 - 12 */  |
| 619 | png_byte day; /* day of month, 1 - 31 */  |
| 620 | png_byte hour; /* hour of day, 0 - 23 */  |
| 621 | png_byte minute; /* minute of hour, 0 - 59 */  |
| 622 | png_byte second; /* second of minute, 0 - 60 (for leap seconds) */  |
| 623 | } png_time;  |
| 624 | typedef png_time * png_timep;  |
| 625 | typedef const png_time * png_const_timep;  |
| 626 | typedef png_time * * png_timepp;  |
| 627 |   |
| 628 | #if defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED) ||\  |
| 629 | defined(PNG_USER_CHUNKS_SUPPORTED)  |
| 630 | /* png_unknown_chunk is a structure to hold queued chunks for which there is  |
| 631 | * no specific support. The idea is that we can use this to queue  |
| 632 | * up private chunks for output even though the library doesn't actually  |
| 633 | * know about their semantics.  |
| 634 | *  |
| 635 | * The data in the structure is set by libpng on read and used on write.  |
| 636 | */  |
| 637 | typedef struct png_unknown_chunk_t  |
| 638 | {  |
| 639 | png_byte name[5]; /* Textual chunk name with '\0' terminator */  |
| 640 | png_byte *data; /* Data, should not be modified on read! */  |
| 641 | size_t size;  |
| 642 |   |
| 643 | /* On write 'location' must be set using the flag values listed below.  |
| 644 | * Notice that on read it is set by libpng however the values stored have  |
| 645 | * more bits set than are listed below. Always treat the value as a  |
| 646 | * bitmask. On write set only one bit - setting multiple bits may cause the  |
| 647 | * chunk to be written in multiple places.  |
| 648 | */  |
| 649 | png_byte location; /* mode of operation at read time */  |
| 650 | }  |
| 651 | png_unknown_chunk;  |
| 652 |   |
| 653 | typedef png_unknown_chunk * png_unknown_chunkp;  |
| 654 | typedef const png_unknown_chunk * png_const_unknown_chunkp;  |
| 655 | typedef png_unknown_chunk * * png_unknown_chunkpp;  |
| 656 | #endif  |
| 657 |   |
| 658 | /* Flag values for the unknown chunk location byte. */  |
| 659 | #define PNG_HAVE_IHDR 0x01  |
| 660 | #define PNG_HAVE_PLTE 0x02  |
| 661 | #define PNG_AFTER_IDAT 0x08  |
| 662 |   |
| 663 | /* Maximum positive integer used in PNG is (2^31)-1 */  |
| 664 | #define PNG_UINT_31_MAX ((png_uint_32)0x7fffffffL)  |
| 665 | #define PNG_UINT_32_MAX ((png_uint_32)(-1))  |
| 666 | #define PNG_SIZE_MAX ((size_t)(-1))  |
| 667 |   |
| 668 | /* These are constants for fixed point values encoded in the  |
| 669 | * PNG specification manner (x100000)  |
| 670 | */  |
| 671 | #define PNG_FP_1 100000  |
| 672 | #define PNG_FP_HALF 50000  |
| 673 | #define PNG_FP_MAX ((png_fixed_point)0x7fffffffL)  |
| 674 | #define PNG_FP_MIN (-PNG_FP_MAX)  |
| 675 |   |
| 676 | /* These describe the color_type field in png_info. */  |
| 677 | /* color type masks */  |
| 678 | #define PNG_COLOR_MASK_PALETTE 1  |
| 679 | #define PNG_COLOR_MASK_COLOR 2  |
| 680 | #define PNG_COLOR_MASK_ALPHA 4  |
| 681 |   |
| 682 | /* color types. Note that not all combinations are legal */  |
| 683 | #define PNG_COLOR_TYPE_GRAY 0  |
| 684 | #define PNG_COLOR_TYPE_PALETTE (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE)  |
| 685 | #define PNG_COLOR_TYPE_RGB (PNG_COLOR_MASK_COLOR)  |
| 686 | #define PNG_COLOR_TYPE_RGB_ALPHA (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_ALPHA)  |
| 687 | #define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA)  |
| 688 | /* aliases */  |
| 689 | #define PNG_COLOR_TYPE_RGBA PNG_COLOR_TYPE_RGB_ALPHA  |
| 690 | #define PNG_COLOR_TYPE_GA PNG_COLOR_TYPE_GRAY_ALPHA  |
| 691 |   |
| 692 | /* This is for compression type. PNG 1.0-1.2 only define the single type. */  |
| 693 | #define PNG_COMPRESSION_TYPE_BASE 0 /* Deflate method 8, 32K window */  |
| 694 | #define PNG_COMPRESSION_TYPE_DEFAULT PNG_COMPRESSION_TYPE_BASE  |
| 695 |   |
| 696 | /* This is for filter type. PNG 1.0-1.2 only define the single type. */  |
| 697 | #define PNG_FILTER_TYPE_BASE 0 /* Single row per-byte filtering */  |
| 698 | #define PNG_INTRAPIXEL_DIFFERENCING 64 /* Used only in MNG datastreams */  |
| 699 | #define PNG_FILTER_TYPE_DEFAULT PNG_FILTER_TYPE_BASE  |
| 700 |   |
| 701 | /* These are for the interlacing type. These values should NOT be changed. */  |
| 702 | #define PNG_INTERLACE_NONE 0 /* Non-interlaced image */  |
| 703 | #define PNG_INTERLACE_ADAM7 1 /* Adam7 interlacing */  |
| 704 | #define PNG_INTERLACE_LAST 2 /* Not a valid value */  |
| 705 |   |
| 706 | /* These are for the oFFs chunk. These values should NOT be changed. */  |
| 707 | #define PNG_OFFSET_PIXEL 0 /* Offset in pixels */  |
| 708 | #define PNG_OFFSET_MICROMETER 1 /* Offset in micrometers (1/10^6 meter) */  |
| 709 | #define PNG_OFFSET_LAST 2 /* Not a valid value */  |
| 710 |   |
| 711 | /* These are for the pCAL chunk. These values should NOT be changed. */  |
| 712 | #define PNG_EQUATION_LINEAR 0 /* Linear transformation */  |
| 713 | #define PNG_EQUATION_BASE_E 1 /* Exponential base e transform */  |
| 714 | #define PNG_EQUATION_ARBITRARY 2 /* Arbitrary base exponential transform */  |
| 715 | #define PNG_EQUATION_HYPERBOLIC 3 /* Hyperbolic sine transformation */  |
| 716 | #define PNG_EQUATION_LAST 4 /* Not a valid value */  |
| 717 |   |
| 718 | /* These are for the sCAL chunk. These values should NOT be changed. */  |
| 719 | #define PNG_SCALE_UNKNOWN 0 /* unknown unit (image scale) */  |
| 720 | #define PNG_SCALE_METER 1 /* meters per pixel */  |
| 721 | #define PNG_SCALE_RADIAN 2 /* radians per pixel */  |
| 722 | #define PNG_SCALE_LAST 3 /* Not a valid value */  |
| 723 |   |
| 724 | /* These are for the pHYs chunk. These values should NOT be changed. */  |
| 725 | #define PNG_RESOLUTION_UNKNOWN 0 /* pixels/unknown unit (aspect ratio) */  |
| 726 | #define PNG_RESOLUTION_METER 1 /* pixels/meter */  |
| 727 | #define PNG_RESOLUTION_LAST 2 /* Not a valid value */  |
| 728 |   |
| 729 | /* These are for the sRGB chunk. These values should NOT be changed. */  |
| 730 | #define PNG_sRGB_INTENT_PERCEPTUAL 0  |
| 731 | #define PNG_sRGB_INTENT_RELATIVE 1  |
| 732 | #define PNG_sRGB_INTENT_SATURATION 2  |
| 733 | #define PNG_sRGB_INTENT_ABSOLUTE 3  |
| 734 | #define PNG_sRGB_INTENT_LAST 4 /* Not a valid value */  |
| 735 |   |
| 736 | /* This is for text chunks */  |
| 737 | #define PNG_KEYWORD_MAX_LENGTH 79  |
| 738 |   |
| 739 | /* Maximum number of entries in PLTE/sPLT/tRNS arrays */  |
| 740 | #define PNG_MAX_PALETTE_LENGTH 256  |
| 741 |   |
| 742 | /* These determine if an ancillary chunk's data has been successfully read  |
| 743 | * from the PNG header, or if the application has filled in the corresponding  |
| 744 | * data in the info_struct to be written into the output file. The values  |
| 745 | * of the PNG_INFO_<chunk> defines should NOT be changed.  |
| 746 | */  |
| 747 | #define PNG_INFO_gAMA 0x0001U  |
| 748 | #define PNG_INFO_sBIT 0x0002U  |
| 749 | #define PNG_INFO_cHRM 0x0004U  |
| 750 | #define PNG_INFO_PLTE 0x0008U  |
| 751 | #define PNG_INFO_tRNS 0x0010U  |
| 752 | #define PNG_INFO_bKGD 0x0020U  |
| 753 | #define PNG_INFO_hIST 0x0040U  |
| 754 | #define PNG_INFO_pHYs 0x0080U  |
| 755 | #define PNG_INFO_oFFs 0x0100U  |
| 756 | #define PNG_INFO_tIME 0x0200U  |
| 757 | #define PNG_INFO_pCAL 0x0400U  |
| 758 | #define PNG_INFO_sRGB 0x0800U /* GR-P, 0.96a */  |
| 759 | #define PNG_INFO_iCCP 0x1000U /* ESR, 1.0.6 */  |
| 760 | #define PNG_INFO_sPLT 0x2000U /* ESR, 1.0.6 */  |
| 761 | #define PNG_INFO_sCAL 0x4000U /* ESR, 1.0.6 */  |
| 762 | #define PNG_INFO_IDAT 0x8000U /* ESR, 1.0.6 */  |
| 763 | #define PNG_INFO_eXIf 0x10000U /* GR-P, 1.6.31 */  |
| 764 | #ifdef PNG_APNG_SUPPORTED  |
| 765 | #define PNG_INFO_acTL 0x20000U  |
| 766 | #define PNG_INFO_fcTL 0x40000U  |
| 767 | #endif  |
| 768 |   |
| 769 | /* This is used for the transformation routines, as some of them  |
| 770 | * change these values for the row. It also should enable using  |
| 771 | * the routines for other purposes.  |
| 772 | */  |
| 773 | typedef struct png_row_info_struct  |
| 774 | {  |
| 775 | png_uint_32 width; /* width of row */  |
| 776 | size_t rowbytes; /* number of bytes in row */  |
| 777 | png_byte color_type; /* color type of row */  |
| 778 | png_byte bit_depth; /* bit depth of row */  |
| 779 | png_byte channels; /* number of channels (1, 2, 3, or 4) */  |
| 780 | png_byte pixel_depth; /* bits per pixel (depth * channels) */  |
| 781 | } png_row_info;  |
| 782 |   |
| 783 | typedef png_row_info * png_row_infop;  |
| 784 | typedef png_row_info * * png_row_infopp;  |
| 785 |   |
| 786 | /* These are the function types for the I/O functions and for the functions  |
| 787 | * that allow the user to override the default I/O functions with his or her  |
| 788 | * own. The png_error_ptr type should match that of user-supplied warning  |
| 789 | * and error functions, while the png_rw_ptr type should match that of the  |
| 790 | * user read/write data functions. Note that the 'write' function must not  |
| 791 | * modify the buffer it is passed. The 'read' function, on the other hand, is  |
| 792 | * expected to return the read data in the buffer.  |
| 793 | */  |
| 794 | typedef PNG_CALLBACK(void, *png_error_ptr, (png_structp, png_const_charp));  |
| 795 | typedef PNG_CALLBACK(void, *png_rw_ptr, (png_structp, png_bytep, size_t));  |
| 796 | typedef PNG_CALLBACK(void, *png_flush_ptr, (png_structp));  |
| 797 | typedef PNG_CALLBACK(void, *png_read_status_ptr, (png_structp, png_uint_32,  |
| 798 | int));  |
| 799 | typedef PNG_CALLBACK(void, *png_write_status_ptr, (png_structp, png_uint_32,  |
| 800 | int));  |
| 801 |   |
| 802 | #ifdef PNG_PROGRESSIVE_READ_SUPPORTED  |
| 803 | typedef PNG_CALLBACK(void, *png_progressive_info_ptr, (png_structp, png_infop));  |
| 804 | typedef PNG_CALLBACK(void, *png_progressive_end_ptr, (png_structp, png_infop));  |
| 805 | #ifdef PNG_APNG_SUPPORTED  |
| 806 | typedef PNG_CALLBACK(void, *png_progressive_frame_ptr, (png_structp,  |
| 807 | png_uint_32));  |
| 808 | #endif  |
| 809 |   |
| 810 | /* The following callback receives png_uint_32 row_number, int pass for the  |
| 811 | * png_bytep data of the row. When transforming an interlaced image the  |
| 812 | * row number is the row number within the sub-image of the interlace pass, so  |
| 813 | * the value will increase to the height of the sub-image (not the full image)  |
| 814 | * then reset to 0 for the next pass.  |
| 815 | *  |
| 816 | * Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to  |
| 817 | * find the output pixel (x,y) given an interlaced sub-image pixel  |
| 818 | * (row,col,pass). (See below for these macros.)  |
| 819 | */  |
| 820 | typedef PNG_CALLBACK(void, *png_progressive_row_ptr, (png_structp, png_bytep,  |
| 821 | png_uint_32, int));  |
| 822 | #endif  |
| 823 |   |
| 824 | #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \  |
| 825 | defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)  |
| 826 | typedef PNG_CALLBACK(void, *png_user_transform_ptr, (png_structp, png_row_infop,  |
| 827 | png_bytep));  |
| 828 | #endif  |
| 829 |   |
| 830 | #ifdef PNG_USER_CHUNKS_SUPPORTED  |
| 831 | typedef PNG_CALLBACK(int, *png_user_chunk_ptr, (png_structp,  |
| 832 | png_unknown_chunkp));  |
| 833 | #endif  |
| 834 | #ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED  |
| 835 | /* not used anywhere */  |
| 836 | /* typedef PNG_CALLBACK(void, *png_unknown_chunk_ptr, (png_structp)); */  |
| 837 | #endif  |
| 838 |   |
| 839 | #ifdef PNG_SETJMP_SUPPORTED  |
| 840 | /* This must match the function definition in <setjmp.h>, and the application  |
| 841 | * must include this before png.h to obtain the definition of jmp_buf. The  |
| 842 | * function is required to be PNG_NORETURN, but this is not checked. If the  |
| 843 | * function does return the application will crash via an abort() or similar  |
| 844 | * system level call.  |
| 845 | *  |
| 846 | * If you get a warning here while building the library you may need to make  |
| 847 | * changes to ensure that pnglibconf.h records the calling convention used by  |
| 848 | * your compiler. This may be very difficult - try using a different compiler  |
| 849 | * to build the library!  |
| 850 | */  |
| 851 | PNG_FUNCTION(void, (PNGCAPI *png_longjmp_ptr), PNGARG((jmp_buf, int)), typedef);  |
| 852 | #endif  |
| 853 |   |
| 854 | /* Transform masks for the high-level interface */  |
| 855 | #define PNG_TRANSFORM_IDENTITY 0x0000 /* read and write */  |
| 856 | #define PNG_TRANSFORM_STRIP_16 0x0001 /* read only */  |
| 857 | #define PNG_TRANSFORM_STRIP_ALPHA 0x0002 /* read only */  |
| 858 | #define PNG_TRANSFORM_PACKING 0x0004 /* read and write */  |
| 859 | #define PNG_TRANSFORM_PACKSWAP 0x0008 /* read and write */  |
| 860 | #define PNG_TRANSFORM_EXPAND 0x0010 /* read only */  |
| 861 | #define PNG_TRANSFORM_INVERT_MONO 0x0020 /* read and write */  |
| 862 | #define PNG_TRANSFORM_SHIFT 0x0040 /* read and write */  |
| 863 | #define PNG_TRANSFORM_BGR 0x0080 /* read and write */  |
| 864 | #define PNG_TRANSFORM_SWAP_ALPHA 0x0100 /* read and write */  |
| 865 | #define PNG_TRANSFORM_SWAP_ENDIAN 0x0200 /* read and write */  |
| 866 | #define PNG_TRANSFORM_INVERT_ALPHA 0x0400 /* read and write */  |
| 867 | #define PNG_TRANSFORM_STRIP_FILLER 0x0800 /* write only */  |
| 868 | /* Added to libpng-1.2.34 */  |
| 869 | #define PNG_TRANSFORM_STRIP_FILLER_BEFORE PNG_TRANSFORM_STRIP_FILLER  |
| 870 | #define PNG_TRANSFORM_STRIP_FILLER_AFTER 0x1000 /* write only */  |
| 871 | /* Added to libpng-1.4.0 */  |
| 872 | #define PNG_TRANSFORM_GRAY_TO_RGB 0x2000 /* read only */  |
| 873 | /* Added to libpng-1.5.4 */  |
| 874 | #define PNG_TRANSFORM_EXPAND_16 0x4000 /* read only */  |
| 875 | #if INT_MAX >= 0x8000 /* else this might break */  |
| 876 | #define PNG_TRANSFORM_SCALE_16 0x8000 /* read only */  |
| 877 | #endif  |
| 878 |   |
| 879 | /* Flags for MNG supported features */  |
| 880 | #define PNG_FLAG_MNG_EMPTY_PLTE 0x01  |
| 881 | #define PNG_FLAG_MNG_FILTER_64 0x04  |
| 882 | #define PNG_ALL_MNG_FEATURES 0x05  |
| 883 |   |
| 884 | /* NOTE: prior to 1.5 these functions had no 'API' style declaration,  |
| 885 | * this allowed the zlib default functions to be used on Windows  |
| 886 | * platforms. In 1.5 the zlib default malloc (which just calls malloc and  |
| 887 | * ignores the first argument) should be completely compatible with the  |
| 888 | * following.  |
| 889 | */  |
| 890 | typedef PNG_CALLBACK(png_voidp, *png_malloc_ptr, (png_structp,  |
| 891 | png_alloc_size_t));  |
| 892 | typedef PNG_CALLBACK(void, *png_free_ptr, (png_structp, png_voidp));  |
| 893 |   |
| 894 | /* Section 4: exported functions  |
| 895 | * Here are the function definitions most commonly used. This is not  |
| 896 | * the place to find out how to use libpng. See libpng-manual.txt for the  |
| 897 | * full explanation, see example.c for the summary. This just provides  |
| 898 | * a simple one line description of the use of each function.  |
| 899 | *  |
| 900 | * The PNG_EXPORT() and PNG_EXPORTA() macros used below are defined in  |
| 901 | * pngconf.h and in the *.dfn files in the scripts directory.  |
| 902 | *  |
| 903 | * PNG_EXPORT(ordinal, type, name, (args));  |
| 904 | *  |
| 905 | * ordinal: ordinal that is used while building  |
| 906 | * *.def files. The ordinal value is only  |
| 907 | * relevant when preprocessing png.h with  |
| 908 | * the *.dfn files for building symbol table  |
| 909 | * entries, and are removed by pngconf.h.  |
| 910 | * type: return type of the function  |
| 911 | * name: function name  |
| 912 | * args: function arguments, with types  |
| 913 | *  |
| 914 | * When we wish to append attributes to a function prototype we use  |
| 915 | * the PNG_EXPORTA() macro instead.  |
| 916 | *  |
| 917 | * PNG_EXPORTA(ordinal, type, name, (args), attributes);  |
| 918 | *  |
| 919 | * ordinal, type, name, and args: same as in PNG_EXPORT().  |
| 920 | * attributes: function attributes  |
| 921 | */  |
| 922 |   |
| 923 | /* Returns the version number of the library */  |
| 924 | PNG_EXPORT(1, png_uint_32, png_access_version_number, (void));  |
| 925 |   |
| 926 | /* Tell lib we have already handled the first <num_bytes> magic bytes.  |
| 927 | * Handling more than 8 bytes from the beginning of the file is an error.  |
| 928 | */  |
| 929 | PNG_EXPORT(2, void, png_set_sig_bytes, (png_structrp png_ptr, int num_bytes));  |
| 930 |   |
| 931 | /* Check sig[start] through sig[start + num_to_check - 1] to see if it's a  |
| 932 | * PNG file. Returns zero if the supplied bytes match the 8-byte PNG  |
| 933 | * signature, and non-zero otherwise. Having num_to_check == 0 or  |
| 934 | * start > 7 will always fail (ie return non-zero).  |
| 935 | */  |
| 936 | PNG_EXPORT(3, int, png_sig_cmp, (png_const_bytep sig, size_t start,  |
| 937 | size_t num_to_check));  |
| 938 |   |
| 939 | /* Simple signature checking function. This is the same as calling  |
| 940 | * png_check_sig(sig, n) := !png_sig_cmp(sig, 0, n).  |
| 941 | */  |
| 942 | #define png_check_sig(sig, n) !png_sig_cmp((sig), 0, (n))  |
| 943 |   |
| 944 | /* Allocate and initialize png_ptr struct for reading, and any other memory. */  |
| 945 | PNG_EXPORTA(4, png_structp, png_create_read_struct,  |
| 946 | (png_const_charp user_png_ver, png_voidp error_ptr,  |
| 947 | png_error_ptr error_fn, png_error_ptr warn_fn),  |
| 948 | PNG_ALLOCATED);  |
| 949 |   |
| 950 | /* Allocate and initialize png_ptr struct for writing, and any other memory */  |
| 951 | PNG_EXPORTA(5, png_structp, png_create_write_struct,  |
| 952 | (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,  |
| 953 | png_error_ptr warn_fn),  |
| 954 | PNG_ALLOCATED);  |
| 955 |   |
| 956 | PNG_EXPORT(6, size_t, png_get_compression_buffer_size,  |
| 957 | (png_const_structrp png_ptr));  |
| 958 |   |
| 959 | PNG_EXPORT(7, void, png_set_compression_buffer_size, (png_structrp png_ptr,  |
| 960 | size_t size));  |
| 961 |   |
| 962 | /* Moved from pngconf.h in 1.4.0 and modified to ensure setjmp/longjmp  |
| 963 | * match up.  |
| 964 | */  |
| 965 | #ifdef PNG_SETJMP_SUPPORTED  |
| 966 | /* This function returns the jmp_buf built in to *png_ptr. It must be  |
| 967 | * supplied with an appropriate 'longjmp' function to use on that jmp_buf  |
| 968 | * unless the default error function is overridden in which case NULL is  |
| 969 | * acceptable. The size of the jmp_buf is checked against the actual size  |
| 970 | * allocated by the library - the call will return NULL on a mismatch  |
| 971 | * indicating an ABI mismatch.  |
| 972 | */  |
| 973 | PNG_EXPORT(8, jmp_buf*, png_set_longjmp_fn, (png_structrp png_ptr,  |
| 974 | png_longjmp_ptr longjmp_fn, size_t jmp_buf_size));  |
| 975 | # define png_jmpbuf(png_ptr) \  |
| 976 | (*png_set_longjmp_fn((png_ptr), longjmp, (sizeof (jmp_buf))))  |
| 977 | #else  |
| 978 | # define png_jmpbuf(png_ptr) \  |
| 979 | (LIBPNG_WAS_COMPILED_WITH__PNG_NO_SETJMP)  |
| 980 | #endif  |
| 981 | /* This function should be used by libpng applications in place of  |
| 982 | * longjmp(png_ptr->jmpbuf, val). If longjmp_fn() has been set, it  |
| 983 | * will use it; otherwise it will call PNG_ABORT(). This function was  |
| 984 | * added in libpng-1.5.0.  |
| 985 | */  |
| 986 | PNG_EXPORTA(9, void, png_longjmp, (png_const_structrp png_ptr, int val),  |
| 987 | PNG_NORETURN);  |
| 988 |   |
| 989 | #ifdef PNG_READ_SUPPORTED  |
| 990 | /* Reset the compression stream */  |
| 991 | PNG_EXPORTA(10, int, png_reset_zstream, (png_structrp png_ptr), PNG_DEPRECATED);  |
| 992 | #endif  |
| 993 |   |
| 994 | /* New functions added in libpng-1.0.2 (not enabled by default until 1.2.0) */  |
| 995 | #ifdef PNG_USER_MEM_SUPPORTED  |
| 996 | PNG_EXPORTA(11, png_structp, png_create_read_struct_2,  |
| 997 | (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,  |
| 998 | png_error_ptr warn_fn,  |
| 999 | png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn),  |
| 1000 | PNG_ALLOCATED);  |
| 1001 | PNG_EXPORTA(12, png_structp, png_create_write_struct_2,  |
| 1002 | (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,  |
| 1003 | png_error_ptr warn_fn,  |
| 1004 | png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn),  |
| 1005 | PNG_ALLOCATED);  |
| 1006 | #endif  |
| 1007 |   |
| 1008 | /* Write the PNG file signature. */  |
| 1009 | PNG_EXPORT(13, void, png_write_sig, (png_structrp png_ptr));  |
| 1010 |   |
| 1011 | /* Write a PNG chunk - size, type, (optional) data, CRC. */  |
| 1012 | PNG_EXPORT(14, void, png_write_chunk, (png_structrp png_ptr, png_const_bytep  |
| 1013 | chunk_name, png_const_bytep data, size_t length));  |
| 1014 |   |
| 1015 | /* Write the start of a PNG chunk - length and chunk name. */  |
| 1016 | PNG_EXPORT(15, void, png_write_chunk_start, (png_structrp png_ptr,  |
| 1017 | png_const_bytep chunk_name, png_uint_32 length));  |
| 1018 |   |
| 1019 | /* Write the data of a PNG chunk started with png_write_chunk_start(). */  |
| 1020 | PNG_EXPORT(16, void, png_write_chunk_data, (png_structrp png_ptr,  |
| 1021 | png_const_bytep data, size_t length));  |
| 1022 |   |
| 1023 | /* Finish a chunk started with png_write_chunk_start() (includes CRC). */  |
| 1024 | PNG_EXPORT(17, void, png_write_chunk_end, (png_structrp png_ptr));  |
| 1025 |   |
| 1026 | /* Allocate and initialize the info structure */  |
| 1027 | PNG_EXPORTA(18, png_infop, png_create_info_struct, (png_const_structrp png_ptr),  |
| 1028 | PNG_ALLOCATED);  |
| 1029 |   |
| 1030 | /* DEPRECATED: this function allowed init structures to be created using the  |
| 1031 | * default allocation method (typically malloc). Use is deprecated in 1.6.0 and  |
| 1032 | * the API will be removed in the future.  |
| 1033 | */  |
| 1034 | PNG_EXPORTA(19, void, png_info_init_3, (png_infopp info_ptr,  |
| 1035 | size_t png_info_struct_size), PNG_DEPRECATED);  |
| 1036 |   |
| 1037 | /* Writes all the PNG information before the image. */  |
| 1038 | PNG_EXPORT(20, void, png_write_info_before_PLTE,  |
| 1039 | (png_structrp png_ptr, png_const_inforp info_ptr));  |
| 1040 | PNG_EXPORT(21, void, png_write_info,  |
| 1041 | (png_structrp png_ptr, png_const_inforp info_ptr));  |
| 1042 |   |
| 1043 | #ifdef PNG_SEQUENTIAL_READ_SUPPORTED  |
| 1044 | /* Read the information before the actual image data. */  |
| 1045 | PNG_EXPORT(22, void, png_read_info,  |
| 1046 | (png_structrp png_ptr, png_inforp info_ptr));  |
| 1047 | #endif  |
| 1048 |   |
| 1049 | #ifdef PNG_TIME_RFC1123_SUPPORTED  |
| 1050 | /* Convert to a US string format: there is no localization support in this  |
| 1051 | * routine. The original implementation used a 29 character buffer in  |
| 1052 | * png_struct, this will be removed in future versions.  |
| 1053 | */  |
| 1054 | #if PNG_LIBPNG_VER < 10700  |
| 1055 | /* To do: remove this from libpng17 (and from libpng17/png.c and pngstruct.h) */  |
| 1056 | PNG_EXPORTA(23, png_const_charp, png_convert_to_rfc1123, (png_structrp png_ptr,  |
| 1057 | png_const_timep ptime),PNG_DEPRECATED);  |
| 1058 | #endif  |
| 1059 | PNG_EXPORT(241, int, png_convert_to_rfc1123_buffer, (char out[29],  |
| 1060 | png_const_timep ptime));  |
| 1061 | #endif  |
| 1062 |   |
| 1063 | #ifdef PNG_CONVERT_tIME_SUPPORTED  |
| 1064 | /* Convert from a struct tm to png_time */  |
| 1065 | PNG_EXPORT(24, void, png_convert_from_struct_tm, (png_timep ptime,  |
| 1066 | const struct tm * ttime));  |
| 1067 |   |
| 1068 | /* Convert from time_t to png_time. Uses gmtime() */  |
| 1069 | PNG_EXPORT(25, void, png_convert_from_time_t, (png_timep ptime, time_t ttime));  |
| 1070 | #endif /* CONVERT_tIME */  |
| 1071 |   |
| 1072 | #ifdef PNG_READ_EXPAND_SUPPORTED  |
| 1073 | /* Expand data to 24-bit RGB, or 8-bit grayscale, with alpha if available. */  |
| 1074 | PNG_EXPORT(26, void, png_set_expand, (png_structrp png_ptr));  |
| 1075 | PNG_EXPORT(27, void, png_set_expand_gray_1_2_4_to_8, (png_structrp png_ptr));  |
| 1076 | PNG_EXPORT(28, void, png_set_palette_to_rgb, (png_structrp png_ptr));  |
| 1077 | PNG_EXPORT(29, void, png_set_tRNS_to_alpha, (png_structrp png_ptr));  |
| 1078 | #endif  |
| 1079 |   |
| 1080 | #ifdef PNG_READ_EXPAND_16_SUPPORTED  |
| 1081 | /* Expand to 16-bit channels, forces conversion of palette to RGB and expansion  |
| 1082 | * of a tRNS chunk if present.  |
| 1083 | */  |
| 1084 | PNG_EXPORT(221, void, png_set_expand_16, (png_structrp png_ptr));  |
| 1085 | #endif  |
| 1086 |   |
| 1087 | #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)  |
| 1088 | /* Use blue, green, red order for pixels. */  |
| 1089 | PNG_EXPORT(30, void, png_set_bgr, (png_structrp png_ptr));  |
| 1090 | #endif  |
| 1091 |   |
| 1092 | #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED  |
| 1093 | /* Expand the grayscale to 24-bit RGB if necessary. */  |
| 1094 | PNG_EXPORT(31, void, png_set_gray_to_rgb, (png_structrp png_ptr));  |
| 1095 | #endif  |
| 1096 |   |
| 1097 | #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED  |
| 1098 | /* Reduce RGB to grayscale. */  |
| 1099 | #define PNG_ERROR_ACTION_NONE 1  |
| 1100 | #define PNG_ERROR_ACTION_WARN 2  |
| 1101 | #define PNG_ERROR_ACTION_ERROR 3  |
| 1102 | #define PNG_RGB_TO_GRAY_DEFAULT (-1)/*for red/green coefficients*/  |
| 1103 |   |
| 1104 | PNG_FP_EXPORT(32, void, png_set_rgb_to_gray, (png_structrp png_ptr,  |
| 1105 | int error_action, double red, double green))  |
| 1106 | PNG_FIXED_EXPORT(33, void, png_set_rgb_to_gray_fixed, (png_structrp png_ptr,  |
| 1107 | int error_action, png_fixed_point red, png_fixed_point green))  |
| 1108 |   |
| 1109 | PNG_EXPORT(34, png_byte, png_get_rgb_to_gray_status, (png_const_structrp  |
| 1110 | png_ptr));  |
| 1111 | #endif  |
| 1112 |   |
| 1113 | #ifdef PNG_BUILD_GRAYSCALE_PALETTE_SUPPORTED  |
| 1114 | PNG_EXPORT(35, void, png_build_grayscale_palette, (int bit_depth,  |
| 1115 | png_colorp palette));  |
| 1116 | #endif  |
| 1117 |   |
| 1118 | #ifdef PNG_READ_ALPHA_MODE_SUPPORTED  |
| 1119 | /* How the alpha channel is interpreted - this affects how the color channels  |
| 1120 | * of a PNG file are returned to the calling application when an alpha channel,  |
| 1121 | * or a tRNS chunk in a palette file, is present.  |
| 1122 | *  |
| 1123 | * This has no effect on the way pixels are written into a PNG output  |
| 1124 | * datastream. The color samples in a PNG datastream are never premultiplied  |
| 1125 | * with the alpha samples.  |
| 1126 | *  |
| 1127 | * The default is to return data according to the PNG specification: the alpha  |
| 1128 | * channel is a linear measure of the contribution of the pixel to the  |
| 1129 | * corresponding composited pixel, and the color channels are unassociated  |
| 1130 | * (not premultiplied). The gamma encoded color channels must be scaled  |
| 1131 | * according to the contribution and to do this it is necessary to undo  |
| 1132 | * the encoding, scale the color values, perform the composition and re-encode  |
| 1133 | * the values. This is the 'PNG' mode.  |
| 1134 | *  |
| 1135 | * The alternative is to 'associate' the alpha with the color information by  |
| 1136 | * storing color channel values that have been scaled by the alpha.  |
| 1137 | * image. These are the 'STANDARD', 'ASSOCIATED' or 'PREMULTIPLIED' modes  |
| 1138 | * (the latter being the two common names for associated alpha color channels).  |
| 1139 | *  |
| 1140 | * For the 'OPTIMIZED' mode, a pixel is treated as opaque only if the alpha  |
| 1141 | * value is equal to the maximum value.  |
| 1142 | *  |
| 1143 | * The final choice is to gamma encode the alpha channel as well. This is  |
| 1144 | * broken because, in practice, no implementation that uses this choice  |
| 1145 | * correctly undoes the encoding before handling alpha composition. Use this  |
| 1146 | * choice only if other serious errors in the software or hardware you use  |
| 1147 | * mandate it; the typical serious error is for dark halos to appear around  |
| 1148 | * opaque areas of the composited PNG image because of arithmetic overflow.  |
| 1149 | *  |
| 1150 | * The API function png_set_alpha_mode specifies which of these choices to use  |
| 1151 | * with an enumerated 'mode' value and the gamma of the required output:  |
| 1152 | */  |
| 1153 | #define PNG_ALPHA_PNG 0 /* according to the PNG standard */  |
| 1154 | #define PNG_ALPHA_STANDARD 1 /* according to Porter/Duff */  |
| 1155 | #define PNG_ALPHA_ASSOCIATED 1 /* as above; this is the normal practice */  |
| 1156 | #define PNG_ALPHA_PREMULTIPLIED 1 /* as above */  |
| 1157 | #define PNG_ALPHA_OPTIMIZED 2 /* 'PNG' for opaque pixels, else 'STANDARD' */  |
| 1158 | #define PNG_ALPHA_BROKEN 3 /* the alpha channel is gamma encoded */  |
| 1159 |   |
| 1160 | PNG_FP_EXPORT(227, void, png_set_alpha_mode, (png_structrp png_ptr, int mode,  |
| 1161 | double output_gamma))  |
| 1162 | PNG_FIXED_EXPORT(228, void, png_set_alpha_mode_fixed, (png_structrp png_ptr,  |
| 1163 | int mode, png_fixed_point output_gamma))  |
| 1164 | #endif  |
| 1165 |   |
| 1166 | #if defined(PNG_GAMMA_SUPPORTED) || defined(PNG_READ_ALPHA_MODE_SUPPORTED)  |
| 1167 | /* The output_gamma value is a screen gamma in libpng terminology: it expresses  |
| 1168 | * how to decode the output values, not how they are encoded.  |
| 1169 | */  |
| 1170 | #define PNG_DEFAULT_sRGB -1 /* sRGB gamma and color space */  |
| 1171 | #define PNG_GAMMA_MAC_18 -2 /* Old Mac '1.8' gamma and color space */  |
| 1172 | #define PNG_GAMMA_sRGB 220000 /* Television standards--matches sRGB gamma */  |
| 1173 | #define PNG_GAMMA_LINEAR PNG_FP_1 /* Linear */  |
| 1174 | #endif  |
| 1175 |   |
| 1176 | /* The following are examples of calls to png_set_alpha_mode to achieve the  |
| 1177 | * required overall gamma correction and, where necessary, alpha  |
| 1178 | * premultiplication.  |
| 1179 | *  |
| 1180 | * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB);  |
| 1181 | * This is the default libpng handling of the alpha channel - it is not  |
| 1182 | * pre-multiplied into the color components. In addition the call states  |
| 1183 | * that the output is for a sRGB system and causes all PNG files without gAMA  |
| 1184 | * chunks to be assumed to be encoded using sRGB.  |
| 1185 | *  |
| 1186 | * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC);  |
| 1187 | * In this case the output is assumed to be something like an sRGB conformant  |
| 1188 | * display preceded by a power-law lookup table of power 1.45. This is how  |
| 1189 | * early Mac systems behaved.  |
| 1190 | *  |
| 1191 | * png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_GAMMA_LINEAR);  |
| 1192 | * This is the classic Jim Blinn approach and will work in academic  |
| 1193 | * environments where everything is done by the book. It has the shortcoming  |
| 1194 | * of assuming that input PNG data with no gamma information is linear - this  |
| 1195 | * is unlikely to be correct unless the PNG files where generated locally.  |
| 1196 | * Most of the time the output precision will be so low as to show  |
| 1197 | * significant banding in dark areas of the image.  |
| 1198 | *  |
| 1199 | * png_set_expand_16(pp);  |
| 1200 | * png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_DEFAULT_sRGB);  |
| 1201 | * This is a somewhat more realistic Jim Blinn inspired approach. PNG files  |
| 1202 | * are assumed to have the sRGB encoding if not marked with a gamma value and  |
| 1203 | * the output is always 16 bits per component. This permits accurate scaling  |
| 1204 | * and processing of the data. If you know that your input PNG files were  |
| 1205 | * generated locally you might need to replace PNG_DEFAULT_sRGB with the  |
| 1206 | * correct value for your system.  |
| 1207 | *  |
| 1208 | * png_set_alpha_mode(pp, PNG_ALPHA_OPTIMIZED, PNG_DEFAULT_sRGB);  |
| 1209 | * If you just need to composite the PNG image onto an existing background  |
| 1210 | * and if you control the code that does this you can use the optimization  |
| 1211 | * setting. In this case you just copy completely opaque pixels to the  |
| 1212 | * output. For pixels that are not completely transparent (you just skip  |
| 1213 | * those) you do the composition math using png_composite or png_composite_16  |
| 1214 | * below then encode the resultant 8-bit or 16-bit values to match the output  |
| 1215 | * encoding.  |
| 1216 | *  |
| 1217 | * Other cases  |
| 1218 | * If neither the PNG nor the standard linear encoding work for you because  |
| 1219 | * of the software or hardware you use then you have a big problem. The PNG  |
| 1220 | * case will probably result in halos around the image. The linear encoding  |
| 1221 | * will probably result in a washed out, too bright, image (it's actually too  |
| 1222 | * contrasty.) Try the ALPHA_OPTIMIZED mode above - this will probably  |
| 1223 | * substantially reduce the halos. Alternatively try:  |
| 1224 | *  |
| 1225 | * png_set_alpha_mode(pp, PNG_ALPHA_BROKEN, PNG_DEFAULT_sRGB);  |
| 1226 | * This option will also reduce the halos, but there will be slight dark  |
| 1227 | * halos round the opaque parts of the image where the background is light.  |
| 1228 | * In the OPTIMIZED mode the halos will be light halos where the background  |
| 1229 | * is dark. Take your pick - the halos are unavoidable unless you can get  |
| 1230 | * your hardware/software fixed! (The OPTIMIZED approach is slightly  |
| 1231 | * faster.)  |
| 1232 | *  |
| 1233 | * When the default gamma of PNG files doesn't match the output gamma.  |
| 1234 | * If you have PNG files with no gamma information png_set_alpha_mode allows  |
| 1235 | * you to provide a default gamma, but it also sets the output gamma to the  |
| 1236 | * matching value. If you know your PNG files have a gamma that doesn't  |
| 1237 | * match the output you can take advantage of the fact that  |
| 1238 | * png_set_alpha_mode always sets the output gamma but only sets the PNG  |
| 1239 | * default if it is not already set:  |
| 1240 | *  |
| 1241 | * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB);  |
| 1242 | * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC);  |
| 1243 | * The first call sets both the default and the output gamma values, the  |
| 1244 | * second call overrides the output gamma without changing the default. This  |
| 1245 | * is easier than achieving the same effect with png_set_gamma. You must use  |
| 1246 | * PNG_ALPHA_PNG for the first call - internal checking in png_set_alpha will  |
| 1247 | * fire if more than one call to png_set_alpha_mode and png_set_background is  |
| 1248 | * made in the same read operation, however multiple calls with PNG_ALPHA_PNG  |
| 1249 | * are ignored.  |
| 1250 | */  |
| 1251 |   |
| 1252 | #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED  |
| 1253 | PNG_EXPORT(36, void, png_set_strip_alpha, (png_structrp png_ptr));  |
| 1254 | #endif  |
| 1255 |   |
| 1256 | #if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \  |
| 1257 | defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)  |
| 1258 | PNG_EXPORT(37, void, png_set_swap_alpha, (png_structrp png_ptr));  |
| 1259 | #endif  |
| 1260 |   |
| 1261 | #if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \  |
| 1262 | defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)  |
| 1263 | PNG_EXPORT(38, void, png_set_invert_alpha, (png_structrp png_ptr));  |
| 1264 | #endif  |
| 1265 |   |
| 1266 | #if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)  |
| 1267 | /* Add a filler byte to 8-bit or 16-bit Gray or 24-bit or 48-bit RGB images. */  |
| 1268 | PNG_EXPORT(39, void, png_set_filler, (png_structrp png_ptr, png_uint_32 filler,  |
| 1269 | int flags));  |
| 1270 | /* The values of the PNG_FILLER_ defines should NOT be changed */  |
| 1271 | # define PNG_FILLER_BEFORE 0  |
| 1272 | # define PNG_FILLER_AFTER 1  |
| 1273 | /* Add an alpha byte to 8-bit or 16-bit Gray or 24-bit or 48-bit RGB images. */  |
| 1274 | PNG_EXPORT(40, void, png_set_add_alpha, (png_structrp png_ptr,  |
| 1275 | png_uint_32 filler, int flags));  |
| 1276 | #endif /* READ_FILLER || WRITE_FILLER */  |
| 1277 |   |
| 1278 | #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)  |
| 1279 | /* Swap bytes in 16-bit depth files. */  |
| 1280 | PNG_EXPORT(41, void, png_set_swap, (png_structrp png_ptr));  |
| 1281 | #endif  |
| 1282 |   |
| 1283 | #if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)  |
| 1284 | /* Use 1 byte per pixel in 1, 2, or 4-bit depth files. */  |
| 1285 | PNG_EXPORT(42, void, png_set_packing, (png_structrp png_ptr));  |
| 1286 | #endif  |
| 1287 |   |
| 1288 | #if defined(PNG_READ_PACKSWAP_SUPPORTED) || \  |
| 1289 | defined(PNG_WRITE_PACKSWAP_SUPPORTED)  |
| 1290 | /* Swap packing order of pixels in bytes. */  |
| 1291 | PNG_EXPORT(43, void, png_set_packswap, (png_structrp png_ptr));  |
| 1292 | #endif  |
| 1293 |   |
| 1294 | #if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)  |
| 1295 | /* Converts files to legal bit depths. */  |
| 1296 | PNG_EXPORT(44, void, png_set_shift, (png_structrp png_ptr, png_const_color_8p  |
| 1297 | true_bits));  |
| 1298 | #endif  |
| 1299 |   |
| 1300 | #if defined(PNG_READ_INTERLACING_SUPPORTED) || \  |
| 1301 | defined(PNG_WRITE_INTERLACING_SUPPORTED)  |
| 1302 | /* Have the code handle the interlacing. Returns the number of passes.  |
| 1303 | * MUST be called before png_read_update_info or png_start_read_image,  |
| 1304 | * otherwise it will not have the desired effect. Note that it is still  |
| 1305 | * necessary to call png_read_row or png_read_rows png_get_image_height  |
| 1306 | * times for each pass.  |
| 1307 | */  |
| 1308 | PNG_EXPORT(45, int, png_set_interlace_handling, (png_structrp png_ptr));  |
| 1309 | #endif  |
| 1310 |   |
| 1311 | #if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)  |
| 1312 | /* Invert monochrome files */  |
| 1313 | PNG_EXPORT(46, void, png_set_invert_mono, (png_structrp png_ptr));  |
| 1314 | #endif  |
| 1315 |   |
| 1316 | #ifdef PNG_READ_BACKGROUND_SUPPORTED  |
| 1317 | /* Handle alpha and tRNS by replacing with a background color. Prior to  |
| 1318 | * libpng-1.5.4 this API must not be called before the PNG file header has been  |
| 1319 | * read. Doing so will result in unexpected behavior and possible warnings or  |
| 1320 | * errors if the PNG file contains a bKGD chunk.  |
| 1321 | */  |
| 1322 | PNG_FP_EXPORT(47, void, png_set_background, (png_structrp png_ptr,  |
| 1323 | png_const_color_16p background_color, int background_gamma_code,  |
| 1324 | int need_expand, double background_gamma))  |
| 1325 | PNG_FIXED_EXPORT(215, void, png_set_background_fixed, (png_structrp png_ptr,  |
| 1326 | png_const_color_16p background_color, int background_gamma_code,  |
| 1327 | int need_expand, png_fixed_point background_gamma))  |
| 1328 | #endif  |
| 1329 | #ifdef PNG_READ_BACKGROUND_SUPPORTED  |
| 1330 | # define PNG_BACKGROUND_GAMMA_UNKNOWN 0  |
| 1331 | # define PNG_BACKGROUND_GAMMA_SCREEN 1  |
| 1332 | # define PNG_BACKGROUND_GAMMA_FILE 2  |
| 1333 | # define PNG_BACKGROUND_GAMMA_UNIQUE 3  |
| 1334 | #endif  |
| 1335 |   |
| 1336 | #ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED  |
| 1337 | /* Scale a 16-bit depth file down to 8-bit, accurately. */  |
| 1338 | PNG_EXPORT(229, void, png_set_scale_16, (png_structrp png_ptr));  |
| 1339 | #endif  |
| 1340 |   |
| 1341 | #ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED  |
| 1342 | #define PNG_READ_16_TO_8_SUPPORTED /* Name prior to 1.5.4 */  |
| 1343 | /* Strip the second byte of information from a 16-bit depth file. */  |
| 1344 | PNG_EXPORT(48, void, png_set_strip_16, (png_structrp png_ptr));  |
| 1345 | #endif  |
| 1346 |   |
| 1347 | #ifdef PNG_READ_QUANTIZE_SUPPORTED  |
| 1348 | /* Turn on quantizing, and reduce the palette to the number of colors  |
| 1349 | * available.  |
| 1350 | */  |
| 1351 | PNG_EXPORT(49, void, png_set_quantize, (png_structrp png_ptr,  |
| 1352 | png_colorp palette, int num_palette, int maximum_colors,  |
| 1353 | png_const_uint_16p histogram, int full_quantize));  |
| 1354 | #endif  |
| 1355 |   |
| 1356 | #ifdef PNG_READ_GAMMA_SUPPORTED  |
| 1357 | /* The threshold on gamma processing is configurable but hard-wired into the  |
| 1358 | * library. The following is the floating point variant.  |
| 1359 | */  |
| 1360 | #define PNG_GAMMA_THRESHOLD (PNG_GAMMA_THRESHOLD_FIXED*.00001)  |
| 1361 |   |
| 1362 | /* Handle gamma correction. Screen_gamma=(display_exponent).  |
| 1363 | * NOTE: this API simply sets the screen and file gamma values. It will  |
| 1364 | * therefore override the value for gamma in a PNG file if it is called after  |
| 1365 | * the file header has been read - use with care - call before reading the PNG  |
| 1366 | * file for best results!  |
| 1367 | *  |
| 1368 | * These routines accept the same gamma values as png_set_alpha_mode (described  |
| 1369 | * above). The PNG_GAMMA_ defines and PNG_DEFAULT_sRGB can be passed to either  |
| 1370 | * API (floating point or fixed.) Notice, however, that the 'file_gamma' value  |
| 1371 | * is the inverse of a 'screen gamma' value.  |
| 1372 | */  |
| 1373 | PNG_FP_EXPORT(50, void, png_set_gamma, (png_structrp png_ptr,  |
| 1374 | double screen_gamma, double override_file_gamma))  |
| 1375 | PNG_FIXED_EXPORT(208, void, png_set_gamma_fixed, (png_structrp png_ptr,  |
| 1376 | png_fixed_point screen_gamma, png_fixed_point override_file_gamma))  |
| 1377 | #endif  |
| 1378 |   |
| 1379 | #ifdef PNG_WRITE_FLUSH_SUPPORTED  |
| 1380 | /* Set how many lines between output flushes - 0 for no flushing */  |
| 1381 | PNG_EXPORT(51, void, png_set_flush, (png_structrp png_ptr, int nrows));  |
| 1382 | /* Flush the current PNG output buffer */  |
| 1383 | PNG_EXPORT(52, void, png_write_flush, (png_structrp png_ptr));  |
| 1384 | #endif  |
| 1385 |   |
| 1386 | /* Optional update palette with requested transformations */  |
| 1387 | PNG_EXPORT(53, void, png_start_read_image, (png_structrp png_ptr));  |
| 1388 |   |
| 1389 | /* Optional call to update the users info structure */  |
| 1390 | PNG_EXPORT(54, void, png_read_update_info, (png_structrp png_ptr,  |
| 1391 | png_inforp info_ptr));  |
| 1392 |   |
| 1393 | #ifdef PNG_SEQUENTIAL_READ_SUPPORTED  |
| 1394 | /* Read one or more rows of image data. */  |
| 1395 | PNG_EXPORT(55, void, png_read_rows, (png_structrp png_ptr, png_bytepp row,  |
| 1396 | png_bytepp display_row, png_uint_32 num_rows));  |
| 1397 | #endif  |
| 1398 |   |
| 1399 | #ifdef PNG_SEQUENTIAL_READ_SUPPORTED  |
| 1400 | /* Read a row of data. */  |
| 1401 | PNG_EXPORT(56, void, png_read_row, (png_structrp png_ptr, png_bytep row,  |
| 1402 | png_bytep display_row));  |
| 1403 | #endif  |
| 1404 |   |
| 1405 | #ifdef PNG_SEQUENTIAL_READ_SUPPORTED  |
| 1406 | /* Read the whole image into memory at once. */  |
| 1407 | PNG_EXPORT(57, void, png_read_image, (png_structrp png_ptr, png_bytepp image));  |
| 1408 | #endif  |
| 1409 |   |
| 1410 | /* Write a row of image data */  |
| 1411 | PNG_EXPORT(58, void, png_write_row, (png_structrp png_ptr,  |
| 1412 | png_const_bytep row));  |
| 1413 |   |
| 1414 | /* Write a few rows of image data: (*row) is not written; however, the type  |
| 1415 | * is declared as writeable to maintain compatibility with previous versions  |
| 1416 | * of libpng and to allow the 'display_row' array from read_rows to be passed  |
| 1417 | * unchanged to write_rows.  |
| 1418 | */  |
| 1419 | PNG_EXPORT(59, void, png_write_rows, (png_structrp png_ptr, png_bytepp row,  |
| 1420 | png_uint_32 num_rows));  |
| 1421 |   |
| 1422 | /* Write the image data */  |
| 1423 | PNG_EXPORT(60, void, png_write_image, (png_structrp png_ptr, png_bytepp image));  |
| 1424 |   |
| 1425 | /* Write the end of the PNG file. */  |
| 1426 | PNG_EXPORT(61, void, png_write_end, (png_structrp png_ptr,  |
| 1427 | png_inforp info_ptr));  |
| 1428 |   |
| 1429 | #ifdef PNG_SEQUENTIAL_READ_SUPPORTED  |
| 1430 | /* Read the end of the PNG file. */  |
| 1431 | PNG_EXPORT(62, void, png_read_end, (png_structrp png_ptr, png_inforp info_ptr));  |
| 1432 | #endif  |
| 1433 |   |
| 1434 | /* Free any memory associated with the png_info_struct */  |
| 1435 | PNG_EXPORT(63, void, png_destroy_info_struct, (png_const_structrp png_ptr,  |
| 1436 | png_infopp info_ptr_ptr));  |
| 1437 |   |
| 1438 | /* Free any memory associated with the png_struct and the png_info_structs */  |
| 1439 | PNG_EXPORT(64, void, png_destroy_read_struct, (png_structpp png_ptr_ptr,  |
| 1440 | png_infopp info_ptr_ptr, png_infopp end_info_ptr_ptr));  |
| 1441 |   |
| 1442 | /* Free any memory associated with the png_struct and the png_info_structs */  |
| 1443 | PNG_EXPORT(65, void, png_destroy_write_struct, (png_structpp png_ptr_ptr,  |
| 1444 | png_infopp info_ptr_ptr));  |
| 1445 |   |
| 1446 | /* Set the libpng method of handling chunk CRC errors */  |
| 1447 | PNG_EXPORT(66, void, png_set_crc_action, (png_structrp png_ptr, int crit_action,  |
| 1448 | int ancil_action));  |
| 1449 |   |
| 1450 | /* Values for png_set_crc_action() say how to handle CRC errors in  |
| 1451 | * ancillary and critical chunks, and whether to use the data contained  |
| 1452 | * therein. Note that it is impossible to "discard" data in a critical  |
| 1453 | * chunk. For versions prior to 0.90, the action was always error/quit,  |
| 1454 | * whereas in version 0.90 and later, the action for CRC errors in ancillary  |
| 1455 | * chunks is warn/discard. These values should NOT be changed.  |
| 1456 | *  |
| 1457 | * value action:critical action:ancillary  |
| 1458 | */  |
| 1459 | #define PNG_CRC_DEFAULT 0 /* error/quit warn/discard data */  |
| 1460 | #define PNG_CRC_ERROR_QUIT 1 /* error/quit error/quit */  |
| 1461 | #define PNG_CRC_WARN_DISCARD 2 /* (INVALID) warn/discard data */  |
| 1462 | #define PNG_CRC_WARN_USE 3 /* warn/use data warn/use data */  |
| 1463 | #define PNG_CRC_QUIET_USE 4 /* quiet/use data quiet/use data */  |
| 1464 | #define PNG_CRC_NO_CHANGE 5 /* use current value use current value */  |
| 1465 |   |
| 1466 | #ifdef PNG_WRITE_SUPPORTED  |
| 1467 | /* These functions give the user control over the scan-line filtering in  |
| 1468 | * libpng and the compression methods used by zlib. These functions are  |
| 1469 | * mainly useful for testing, as the defaults should work with most users.  |
| 1470 | * Those users who are tight on memory or want faster performance at the  |
| 1471 | * expense of compression can modify them. See the compression library  |
| 1472 | * header file (zlib.h) for an explination of the compression functions.  |
| 1473 | */  |
| 1474 |   |
| 1475 | /* Set the filtering method(s) used by libpng. Currently, the only valid  |
| 1476 | * value for "method" is 0.  |
| 1477 | */  |
| 1478 | PNG_EXPORT(67, void, png_set_filter, (png_structrp png_ptr, int method,  |
| 1479 | int filters));  |
| 1480 | #endif /* WRITE */  |
| 1481 |   |
| 1482 | /* Flags for png_set_filter() to say which filters to use. The flags  |
| 1483 | * are chosen so that they don't conflict with real filter types  |
| 1484 | * below, in case they are supplied instead of the #defined constants.  |
| 1485 | * These values should NOT be changed.  |
| 1486 | */  |
| 1487 | #define PNG_NO_FILTERS 0x00  |
| 1488 | #define PNG_FILTER_NONE 0x08  |
| 1489 | #define PNG_FILTER_SUB 0x10  |
| 1490 | #define PNG_FILTER_UP 0x20  |
| 1491 | #define PNG_FILTER_AVG 0x40  |
| 1492 | #define PNG_FILTER_PAETH 0x80  |
| 1493 | #define PNG_FAST_FILTERS (PNG_FILTER_NONE | PNG_FILTER_SUB | PNG_FILTER_UP)  |
| 1494 | #define PNG_ALL_FILTERS (PNG_FAST_FILTERS | PNG_FILTER_AVG | PNG_FILTER_PAETH)  |
| 1495 |   |
| 1496 | /* Filter values (not flags) - used in pngwrite.c, pngwutil.c for now.  |
| 1497 | * These defines should NOT be changed.  |
| 1498 | */  |
| 1499 | #define PNG_FILTER_VALUE_NONE 0  |
| 1500 | #define PNG_FILTER_VALUE_SUB 1  |
| 1501 | #define PNG_FILTER_VALUE_UP 2  |
| 1502 | #define PNG_FILTER_VALUE_AVG 3  |
| 1503 | #define PNG_FILTER_VALUE_PAETH 4  |
| 1504 | #define PNG_FILTER_VALUE_LAST 5  |
| 1505 |   |
| 1506 | #ifdef PNG_WRITE_SUPPORTED  |
| 1507 | #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* DEPRECATED */  |
| 1508 | PNG_FP_EXPORT(68, void, png_set_filter_heuristics, (png_structrp png_ptr,  |
| 1509 | int heuristic_method, int num_weights, png_const_doublep filter_weights,  |
| 1510 | png_const_doublep filter_costs))  |
| 1511 | PNG_FIXED_EXPORT(209, void, png_set_filter_heuristics_fixed,  |
| 1512 | (png_structrp png_ptr, int heuristic_method, int num_weights,  |
| 1513 | png_const_fixed_point_p filter_weights,  |
| 1514 | png_const_fixed_point_p filter_costs))  |
| 1515 | #endif /* WRITE_WEIGHTED_FILTER */  |
| 1516 |   |
| 1517 | /* The following are no longer used and will be removed from libpng-1.7: */  |
| 1518 | #define PNG_FILTER_HEURISTIC_DEFAULT 0 /* Currently "UNWEIGHTED" */  |
| 1519 | #define PNG_FILTER_HEURISTIC_UNWEIGHTED 1 /* Used by libpng < 0.95 */  |
| 1520 | #define PNG_FILTER_HEURISTIC_WEIGHTED 2 /* Experimental feature */  |
| 1521 | #define PNG_FILTER_HEURISTIC_LAST 3 /* Not a valid value */  |
| 1522 |   |
| 1523 | /* Set the library compression level. Currently, valid values range from  |
| 1524 | * 0 - 9, corresponding directly to the zlib compression levels 0 - 9  |
| 1525 | * (0 - no compression, 9 - "maximal" compression). Note that tests have  |
| 1526 | * shown that zlib compression levels 3-6 usually perform as well as level 9  |
| 1527 | * for PNG images, and do considerably fewer caclulations. In the future,  |
| 1528 | * these values may not correspond directly to the zlib compression levels.  |
| 1529 | */  |
| 1530 | #ifdef PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED  |
| 1531 | PNG_EXPORT(69, void, png_set_compression_level, (png_structrp png_ptr,  |
| 1532 | int level));  |
| 1533 |   |
| 1534 | PNG_EXPORT(70, void, png_set_compression_mem_level, (png_structrp png_ptr,  |
| 1535 | int mem_level));  |
| 1536 |   |
| 1537 | PNG_EXPORT(71, void, png_set_compression_strategy, (png_structrp png_ptr,  |
| 1538 | int strategy));  |
| 1539 |   |
| 1540 | /* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a  |
| 1541 | * smaller value of window_bits if it can do so safely.  |
| 1542 | */  |
| 1543 | PNG_EXPORT(72, void, png_set_compression_window_bits, (png_structrp png_ptr,  |
| 1544 | int window_bits));  |
| 1545 |   |
| 1546 | PNG_EXPORT(73, void, png_set_compression_method, (png_structrp png_ptr,  |
| 1547 | int method));  |
| 1548 | #endif /* WRITE_CUSTOMIZE_COMPRESSION */  |
| 1549 |   |
| 1550 | #ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED  |
| 1551 | /* Also set zlib parameters for compressing non-IDAT chunks */  |
| 1552 | PNG_EXPORT(222, void, png_set_text_compression_level, (png_structrp png_ptr,  |
| 1553 | int level));  |
| 1554 |   |
| 1555 | PNG_EXPORT(223, void, png_set_text_compression_mem_level, (png_structrp png_ptr,  |
| 1556 | int mem_level));  |
| 1557 |   |
| 1558 | PNG_EXPORT(224, void, png_set_text_compression_strategy, (png_structrp png_ptr,  |
| 1559 | int strategy));  |
| 1560 |   |
| 1561 | /* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a  |
| 1562 | * smaller value of window_bits if it can do so safely.  |
| 1563 | */  |
| 1564 | PNG_EXPORT(225, void, png_set_text_compression_window_bits,  |
| 1565 | (png_structrp png_ptr, int window_bits));  |
| 1566 |   |
| 1567 | PNG_EXPORT(226, void, png_set_text_compression_method, (png_structrp png_ptr,  |
| 1568 | int method));  |
| 1569 | #endif /* WRITE_CUSTOMIZE_ZTXT_COMPRESSION */  |
| 1570 | #endif /* WRITE */  |
| 1571 |   |
| 1572 | /* These next functions are called for input/output, memory, and error  |
| 1573 | * handling. They are in the file pngrio.c, pngwio.c, and pngerror.c,  |
| 1574 | * and call standard C I/O routines such as fread(), fwrite(), and  |
| 1575 | * fprintf(). These functions can be made to use other I/O routines  |
| 1576 | * at run time for those applications that need to handle I/O in a  |
| 1577 | * different manner by calling png_set_???_fn(). See libpng-manual.txt for  |
| 1578 | * more information.  |
| 1579 | */  |
| 1580 |   |
| 1581 | #ifdef PNG_STDIO_SUPPORTED  |
| 1582 | /* Initialize the input/output for the PNG file to the default functions. */  |
| 1583 | PNG_EXPORT(74, void, png_init_io, (png_structrp png_ptr, png_FILE_p fp));  |
| 1584 | #endif  |
| 1585 |   |
| 1586 | /* Replace the (error and abort), and warning functions with user  |
| 1587 | * supplied functions. If no messages are to be printed you must still  |
| 1588 | * write and use replacement functions. The replacement error_fn should  |
| 1589 | * still do a longjmp to the last setjmp location if you are using this  |
| 1590 | * method of error handling. If error_fn or warning_fn is NULL, the  |
| 1591 | * default function will be used.  |
| 1592 | */  |
| 1593 |   |
| 1594 | PNG_EXPORT(75, void, png_set_error_fn, (png_structrp png_ptr,  |
| 1595 | png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warning_fn));  |
| 1596 |   |
| 1597 | /* Return the user pointer associated with the error functions */  |
| 1598 | PNG_EXPORT(76, png_voidp, png_get_error_ptr, (png_const_structrp png_ptr));  |
| 1599 |   |
| 1600 | /* Replace the default data output functions with a user supplied one(s).  |
| 1601 | * If buffered output is not used, then output_flush_fn can be set to NULL.  |
| 1602 | * If PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile time  |
| 1603 | * output_flush_fn will be ignored (and thus can be NULL).  |
| 1604 | * It is probably a mistake to use NULL for output_flush_fn if  |
| 1605 | * write_data_fn is not also NULL unless you have built libpng with  |
| 1606 | * PNG_WRITE_FLUSH_SUPPORTED undefined, because in this case libpng's  |
| 1607 | * default flush function, which uses the standard *FILE structure, will  |
| 1608 | * be used.  |
| 1609 | */  |
| 1610 | PNG_EXPORT(77, void, png_set_write_fn, (png_structrp png_ptr, png_voidp io_ptr,  |
| 1611 | png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn));  |
| 1612 |   |
| 1613 | /* Replace the default data input function with a user supplied one. */  |
| 1614 | PNG_EXPORT(78, void, png_set_read_fn, (png_structrp png_ptr, png_voidp io_ptr,  |
| 1615 | png_rw_ptr read_data_fn));  |
| 1616 |   |
| 1617 | /* Return the user pointer associated with the I/O functions */  |
| 1618 | PNG_EXPORT(79, png_voidp, png_get_io_ptr, (png_const_structrp png_ptr));  |
| 1619 |   |
| 1620 | PNG_EXPORT(80, void, png_set_read_status_fn, (png_structrp png_ptr,  |
| 1621 | png_read_status_ptr read_row_fn));  |
| 1622 |   |
| 1623 | PNG_EXPORT(81, void, png_set_write_status_fn, (png_structrp png_ptr,  |
| 1624 | png_write_status_ptr write_row_fn));  |
| 1625 |   |
| 1626 | #ifdef PNG_USER_MEM_SUPPORTED  |
| 1627 | /* Replace the default memory allocation functions with user supplied one(s). */  |
| 1628 | PNG_EXPORT(82, void, png_set_mem_fn, (png_structrp png_ptr, png_voidp mem_ptr,  |
| 1629 | png_malloc_ptr malloc_fn, png_free_ptr free_fn));  |
| 1630 | /* Return the user pointer associated with the memory functions */  |
| 1631 | PNG_EXPORT(83, png_voidp, png_get_mem_ptr, (png_const_structrp png_ptr));  |
| 1632 | #endif  |
| 1633 |   |
| 1634 | #ifdef PNG_READ_USER_TRANSFORM_SUPPORTED  |
| 1635 | PNG_EXPORT(84, void, png_set_read_user_transform_fn, (png_structrp png_ptr,  |
| 1636 | png_user_transform_ptr read_user_transform_fn));  |
| 1637 | #endif  |
| 1638 |   |
| 1639 | #ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED  |
| 1640 | PNG_EXPORT(85, void, png_set_write_user_transform_fn, (png_structrp png_ptr,  |
| 1641 | png_user_transform_ptr write_user_transform_fn));  |
| 1642 | #endif  |
| 1643 |   |
| 1644 | #ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED  |
| 1645 | PNG_EXPORT(86, void, png_set_user_transform_info, (png_structrp png_ptr,  |
| 1646 | png_voidp user_transform_ptr, int user_transform_depth,  |
| 1647 | int user_transform_channels));  |
| 1648 | /* Return the user pointer associated with the user transform functions */  |
| 1649 | PNG_EXPORT(87, png_voidp, png_get_user_transform_ptr,  |
| 1650 | (png_const_structrp png_ptr));  |
| 1651 | #endif  |
| 1652 |   |
| 1653 | #ifdef PNG_USER_TRANSFORM_INFO_SUPPORTED  |
| 1654 | /* Return information about the row currently being processed. Note that these  |
| 1655 | * APIs do not fail but will return unexpected results if called outside a user  |
| 1656 | * transform callback. Also note that when transforming an interlaced image the  |
| 1657 | * row number is the row number within the sub-image of the interlace pass, so  |
| 1658 | * the value will increase to the height of the sub-image (not the full image)  |
| 1659 | * then reset to 0 for the next pass.  |
| 1660 | *  |
| 1661 | * Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to  |
| 1662 | * find the output pixel (x,y) given an interlaced sub-image pixel  |
| 1663 | * (row,col,pass). (See below for these macros.)  |
| 1664 | */  |
| 1665 | PNG_EXPORT(217, png_uint_32, png_get_current_row_number, (png_const_structrp));  |
| 1666 | PNG_EXPORT(218, png_byte, png_get_current_pass_number, (png_const_structrp));  |
| 1667 | #endif  |
| 1668 |   |
| 1669 | #ifdef PNG_READ_USER_CHUNKS_SUPPORTED  |
| 1670 | /* This callback is called only for *unknown* chunks. If  |
| 1671 | * PNG_HANDLE_AS_UNKNOWN_SUPPORTED is set then it is possible to set known  |
| 1672 | * chunks to be treated as unknown, however in this case the callback must do  |
| 1673 | * any processing required by the chunk (e.g. by calling the appropriate  |
| 1674 | * png_set_ APIs.)  |
| 1675 | *  |
| 1676 | * There is no write support - on write, by default, all the chunks in the  |
| 1677 | * 'unknown' list are written in the specified position.  |
| 1678 | *  |
| 1679 | * The integer return from the callback function is interpreted thus:  |
| 1680 | *  |
| 1681 | * negative: An error occurred; png_chunk_error will be called.  |
| 1682 | * zero: The chunk was not handled, the chunk will be saved. A critical  |
| 1683 | * chunk will cause an error at this point unless it is to be saved.  |
| 1684 | * positive: The chunk was handled, libpng will ignore/discard it.  |
| 1685 | *  |
| 1686 | * See "INTERACTION WITH USER CHUNK CALLBACKS" below for important notes about  |
| 1687 | * how this behavior will change in libpng 1.7  |
| 1688 | */  |
| 1689 | PNG_EXPORT(88, void, png_set_read_user_chunk_fn, (png_structrp png_ptr,  |
| 1690 | png_voidp user_chunk_ptr, png_user_chunk_ptr read_user_chunk_fn));  |
| 1691 | #endif  |
| 1692 |   |
| 1693 | #ifdef PNG_USER_CHUNKS_SUPPORTED  |
| 1694 | PNG_EXPORT(89, png_voidp, png_get_user_chunk_ptr, (png_const_structrp png_ptr));  |
| 1695 | #endif  |
| 1696 |   |
| 1697 | #ifdef PNG_PROGRESSIVE_READ_SUPPORTED  |
| 1698 | /* Sets the function callbacks for the push reader, and a pointer to a  |
| 1699 | * user-defined structure available to the callback functions.  |
| 1700 | */  |
| 1701 | PNG_EXPORT(90, void, png_set_progressive_read_fn, (png_structrp png_ptr,  |
| 1702 | png_voidp progressive_ptr, png_progressive_info_ptr info_fn,  |
| 1703 | png_progressive_row_ptr row_fn, png_progressive_end_ptr end_fn));  |
| 1704 |   |
| 1705 | /* Returns the user pointer associated with the push read functions */  |
| 1706 | PNG_EXPORT(91, png_voidp, png_get_progressive_ptr,  |
| 1707 | (png_const_structrp png_ptr));  |
| 1708 |   |
| 1709 | /* Function to be called when data becomes available */  |
| 1710 | PNG_EXPORT(92, void, png_process_data, (png_structrp png_ptr,  |
| 1711 | png_inforp info_ptr, png_bytep buffer, size_t buffer_size));  |
| 1712 |   |
| 1713 | /* A function which may be called *only* within png_process_data to stop the  |
| 1714 | * processing of any more data. The function returns the number of bytes  |
| 1715 | * remaining, excluding any that libpng has cached internally. A subsequent  |
| 1716 | * call to png_process_data must supply these bytes again. If the argument  |
| 1717 | * 'save' is set to true the routine will first save all the pending data and  |
| 1718 | * will always return 0.  |
| 1719 | */  |
| 1720 | PNG_EXPORT(219, size_t, png_process_data_pause, (png_structrp, int save));  |
| 1721 |   |
| 1722 | /* A function which may be called *only* outside (after) a call to  |
| 1723 | * png_process_data. It returns the number of bytes of data to skip in the  |
| 1724 | * input. Normally it will return 0, but if it returns a non-zero value the  |
| 1725 | * application must skip than number of bytes of input data and pass the  |
| 1726 | * following data to the next call to png_process_data.  |
| 1727 | */  |
| 1728 | PNG_EXPORT(220, png_uint_32, png_process_data_skip, (png_structrp));  |
| 1729 |   |
| 1730 | /* Function that combines rows. 'new_row' is a flag that should come from  |
| 1731 | * the callback and be non-NULL if anything needs to be done; the library  |
| 1732 | * stores its own version of the new data internally and ignores the passed  |
| 1733 | * in value.  |
| 1734 | */  |
| 1735 | PNG_EXPORT(93, void, png_progressive_combine_row, (png_const_structrp png_ptr,  |
| 1736 | png_bytep old_row, png_const_bytep new_row));  |
| 1737 | #endif /* PROGRESSIVE_READ */  |
| 1738 |   |
| 1739 | PNG_EXPORTA(94, png_voidp, png_malloc, (png_const_structrp png_ptr,  |
| 1740 | png_alloc_size_t size), PNG_ALLOCATED);  |
| 1741 | /* Added at libpng version 1.4.0 */  |
| 1742 | PNG_EXPORTA(95, png_voidp, png_calloc, (png_const_structrp png_ptr,  |
| 1743 | png_alloc_size_t size), PNG_ALLOCATED);  |
| 1744 |   |
| 1745 | /* Added at libpng version 1.2.4 */  |
| 1746 | PNG_EXPORTA(96, png_voidp, png_malloc_warn, (png_const_structrp png_ptr,  |
| 1747 | png_alloc_size_t size), PNG_ALLOCATED);  |
| 1748 |   |
| 1749 | /* Frees a pointer allocated by png_malloc() */  |
| 1750 | PNG_EXPORT(97, void, png_free, (png_const_structrp png_ptr, png_voidp ptr));  |
| 1751 |   |
| 1752 | /* Free data that was allocated internally */  |
| 1753 | PNG_EXPORT(98, void, png_free_data, (png_const_structrp png_ptr,  |
| 1754 | png_inforp info_ptr, png_uint_32 free_me, int num));  |
| 1755 |   |
| 1756 | /* Reassign responsibility for freeing existing data, whether allocated  |
| 1757 | * by libpng or by the application; this works on the png_info structure passed  |
| 1758 | * in, it does not change the state for other png_info structures.  |
| 1759 | *  |
| 1760 | * It is unlikely that this function works correctly as of 1.6.0 and using it  |
| 1761 | * may result either in memory leaks or double free of allocated data.  |
| 1762 | */  |
| 1763 | PNG_EXPORT(99, void, png_data_freer, (png_const_structrp png_ptr,  |
| 1764 | png_inforp info_ptr, int freer, png_uint_32 mask));  |
| 1765 |   |
| 1766 | /* Assignments for png_data_freer */  |
| 1767 | #define PNG_DESTROY_WILL_FREE_DATA 1  |
| 1768 | #define PNG_SET_WILL_FREE_DATA 1  |
| 1769 | #define PNG_USER_WILL_FREE_DATA 2  |
| 1770 | /* Flags for png_ptr->free_me and info_ptr->free_me */  |
| 1771 | #define PNG_FREE_HIST 0x0008U  |
| 1772 | #define PNG_FREE_ICCP 0x0010U  |
| 1773 | #define PNG_FREE_SPLT 0x0020U  |
| 1774 | #define PNG_FREE_ROWS 0x0040U  |
| 1775 | #define PNG_FREE_PCAL 0x0080U  |
| 1776 | #define PNG_FREE_SCAL 0x0100U  |
| 1777 | #ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED  |
| 1778 | # define PNG_FREE_UNKN 0x0200U  |
| 1779 | #endif  |
| 1780 | /* PNG_FREE_LIST 0x0400U removed in 1.6.0 because it is ignored */  |
| 1781 | #define PNG_FREE_PLTE 0x1000U  |
| 1782 | #define PNG_FREE_TRNS 0x2000U  |
| 1783 | #define PNG_FREE_TEXT 0x4000U  |
| 1784 | #define PNG_FREE_EXIF 0x8000U /* Added at libpng-1.6.31 */  |
| 1785 | #define PNG_FREE_ALL 0xffffU  |
| 1786 | #define PNG_FREE_MUL 0x4220U /* PNG_FREE_SPLT|PNG_FREE_TEXT|PNG_FREE_UNKN */  |
| 1787 |   |
| 1788 | #ifdef PNG_USER_MEM_SUPPORTED  |
| 1789 | PNG_EXPORTA(100, png_voidp, png_malloc_default, (png_const_structrp png_ptr,  |
| 1790 | png_alloc_size_t size), PNG_ALLOCATED PNG_DEPRECATED);  |
| 1791 | PNG_EXPORTA(101, void, png_free_default, (png_const_structrp png_ptr,  |
| 1792 | png_voidp ptr), PNG_DEPRECATED);  |
| 1793 | #endif  |
| 1794 |   |
| 1795 | #ifdef PNG_ERROR_TEXT_SUPPORTED  |
| 1796 | /* Fatal error in PNG image of libpng - can't continue */  |
| 1797 | PNG_EXPORTA(102, void, png_error, (png_const_structrp png_ptr,  |
| 1798 | png_const_charp error_message), PNG_NORETURN);  |
| 1799 |   |
| 1800 | /* The same, but the chunk name is prepended to the error string. */  |
| 1801 | PNG_EXPORTA(103, void, png_chunk_error, (png_const_structrp png_ptr,  |
| 1802 | png_const_charp error_message), PNG_NORETURN);  |
| 1803 |   |
| 1804 | #else  |
| 1805 | /* Fatal error in PNG image of libpng - can't continue */  |
| 1806 | PNG_EXPORTA(104, void, png_err, (png_const_structrp png_ptr), PNG_NORETURN);  |
| 1807 | # define png_error(s1,s2) png_err(s1)  |
| 1808 | # define png_chunk_error(s1,s2) png_err(s1)  |
| 1809 | #endif  |
| 1810 |   |
| 1811 | #ifdef PNG_WARNINGS_SUPPORTED  |
| 1812 | /* Non-fatal error in libpng. Can continue, but may have a problem. */  |
| 1813 | PNG_EXPORT(105, void, png_warning, (png_const_structrp png_ptr,  |
| 1814 | png_const_charp warning_message));  |
| 1815 |   |
| 1816 | /* Non-fatal error in libpng, chunk name is prepended to message. */  |
| 1817 | PNG_EXPORT(106, void, png_chunk_warning, (png_const_structrp png_ptr,  |
| 1818 | png_const_charp warning_message));  |
| 1819 | #else  |
| 1820 | # define png_warning(s1,s2) ((void)(s1))  |
| 1821 | # define png_chunk_warning(s1,s2) ((void)(s1))  |
| 1822 | #endif  |
| 1823 |   |
| 1824 | #ifdef PNG_BENIGN_ERRORS_SUPPORTED  |
| 1825 | /* Benign error in libpng. Can continue, but may have a problem.  |
| 1826 | * User can choose whether to handle as a fatal error or as a warning. */  |
| 1827 | PNG_EXPORT(107, void, png_benign_error, (png_const_structrp png_ptr,  |
| 1828 | png_const_charp warning_message));  |
| 1829 |   |
| 1830 | #ifdef PNG_READ_SUPPORTED  |
| 1831 | /* Same, chunk name is prepended to message (only during read) */  |
| 1832 | PNG_EXPORT(108, void, png_chunk_benign_error, (png_const_structrp png_ptr,  |
| 1833 | png_const_charp warning_message));  |
| 1834 | #endif  |
| 1835 |   |
| 1836 | PNG_EXPORT(109, void, png_set_benign_errors,  |
| 1837 | (png_structrp png_ptr, int allowed));  |
| 1838 | #else  |
| 1839 | # ifdef PNG_ALLOW_BENIGN_ERRORS  |
| 1840 | # define png_benign_error png_warning  |
| 1841 | # define png_chunk_benign_error png_chunk_warning  |
| 1842 | # else  |
| 1843 | # define png_benign_error png_error  |
| 1844 | # define png_chunk_benign_error png_chunk_error  |
| 1845 | # endif  |
| 1846 | #endif  |
| 1847 |   |
| 1848 | /* The png_set_<chunk> functions are for storing values in the png_info_struct.  |
| 1849 | * Similarly, the png_get_<chunk> calls are used to read values from the  |
| 1850 | * png_info_struct, either storing the parameters in the passed variables, or  |
| 1851 | * setting pointers into the png_info_struct where the data is stored. The  |
| 1852 | * png_get_<chunk> functions return a non-zero value if the data was available  |
| 1853 | * in info_ptr, or return zero and do not change any of the parameters if the  |
| 1854 | * data was not available.  |
| 1855 | *  |
| 1856 | * These functions should be used instead of directly accessing png_info  |
| 1857 | * to avoid problems with future changes in the size and internal layout of  |
| 1858 | * png_info_struct.  |
| 1859 | */  |
| 1860 | /* Returns "flag" if chunk data is valid in info_ptr. */  |
| 1861 | PNG_EXPORT(110, png_uint_32, png_get_valid, (png_const_structrp png_ptr,  |
| 1862 | png_const_inforp info_ptr, png_uint_32 flag));  |
| 1863 |   |
| 1864 | /* Returns number of bytes needed to hold a transformed row. */  |
| 1865 | PNG_EXPORT(111, size_t, png_get_rowbytes, (png_const_structrp png_ptr,  |
| 1866 | png_const_inforp info_ptr));  |
| 1867 |   |
| 1868 | #ifdef PNG_INFO_IMAGE_SUPPORTED  |
| 1869 | /* Returns row_pointers, which is an array of pointers to scanlines that was  |
| 1870 | * returned from png_read_png().  |
| 1871 | */  |
| 1872 | PNG_EXPORT(112, png_bytepp, png_get_rows, (png_const_structrp png_ptr,  |
| 1873 | png_const_inforp info_ptr));  |
| 1874 |   |
| 1875 | /* Set row_pointers, which is an array of pointers to scanlines for use  |
| 1876 | * by png_write_png().  |
| 1877 | */  |
| 1878 | PNG_EXPORT(113, void, png_set_rows, (png_const_structrp png_ptr,  |
| 1879 | png_inforp info_ptr, png_bytepp row_pointers));  |
| 1880 | #endif  |
| 1881 |   |
| 1882 | /* Returns number of color channels in image. */  |
| 1883 | PNG_EXPORT(114, png_byte, png_get_channels, (png_const_structrp png_ptr,  |
| 1884 | png_const_inforp info_ptr));  |
| 1885 |   |
| 1886 | #ifdef PNG_EASY_ACCESS_SUPPORTED  |
| 1887 | /* Returns image width in pixels. */  |
| 1888 | PNG_EXPORT(115, png_uint_32, png_get_image_width, (png_const_structrp png_ptr,  |
| 1889 | png_const_inforp info_ptr));  |
| 1890 |   |
| 1891 | /* Returns image height in pixels. */  |
| 1892 | PNG_EXPORT(116, png_uint_32, png_get_image_height, (png_const_structrp png_ptr,  |
| 1893 | png_const_inforp info_ptr));  |
| 1894 |   |
| 1895 | /* Returns image bit_depth. */  |
| 1896 | PNG_EXPORT(117, png_byte, png_get_bit_depth, (png_const_structrp png_ptr,  |
| 1897 | png_const_inforp info_ptr));  |
| 1898 |   |
| 1899 | /* Returns image color_type. */  |
| 1900 | PNG_EXPORT(118, png_byte, png_get_color_type, (png_const_structrp png_ptr,  |
| 1901 | png_const_inforp info_ptr));  |
| 1902 |   |
| 1903 | /* Returns image filter_type. */  |
| 1904 | PNG_EXPORT(119, png_byte, png_get_filter_type, (png_const_structrp png_ptr,  |
| 1905 | png_const_inforp info_ptr));  |
| 1906 |   |
| 1907 | /* Returns image interlace_type. */  |
| 1908 | PNG_EXPORT(120, png_byte, png_get_interlace_type, (png_const_structrp png_ptr,  |
| 1909 | png_const_inforp info_ptr));  |
| 1910 |   |
| 1911 | /* Returns image compression_type. */  |
| 1912 | PNG_EXPORT(121, png_byte, png_get_compression_type, (png_const_structrp png_ptr,  |
| 1913 | png_const_inforp info_ptr));  |
| 1914 |   |
| 1915 | /* Returns image resolution in pixels per meter, from pHYs chunk data. */  |
| 1916 | PNG_EXPORT(122, png_uint_32, png_get_pixels_per_meter,  |
| 1917 | (png_const_structrp png_ptr, png_const_inforp info_ptr));  |
| 1918 | PNG_EXPORT(123, png_uint_32, png_get_x_pixels_per_meter,  |
| 1919 | (png_const_structrp png_ptr, png_const_inforp info_ptr));  |
| 1920 | PNG_EXPORT(124, png_uint_32, png_get_y_pixels_per_meter,  |
| 1921 | (png_const_structrp png_ptr, png_const_inforp info_ptr));  |
| 1922 |   |
| 1923 | /* Returns pixel aspect ratio, computed from pHYs chunk data. */  |
| 1924 | PNG_FP_EXPORT(125, float, png_get_pixel_aspect_ratio,  |
| 1925 | (png_const_structrp png_ptr, png_const_inforp info_ptr))  |
| 1926 | PNG_FIXED_EXPORT(210, png_fixed_point, png_get_pixel_aspect_ratio_fixed,  |
| 1927 | (png_const_structrp png_ptr, png_const_inforp info_ptr))  |
| 1928 |   |
| 1929 | /* Returns image x, y offset in pixels or microns, from oFFs chunk data. */  |
| 1930 | PNG_EXPORT(126, png_int_32, png_get_x_offset_pixels,  |
| 1931 | (png_const_structrp png_ptr, png_const_inforp info_ptr));  |
| 1932 | PNG_EXPORT(127, png_int_32, png_get_y_offset_pixels,  |
| 1933 | (png_const_structrp png_ptr, png_const_inforp info_ptr));  |
| 1934 | PNG_EXPORT(128, png_int_32, png_get_x_offset_microns,  |
| 1935 | (png_const_structrp png_ptr, png_const_inforp info_ptr));  |
| 1936 | PNG_EXPORT(129, png_int_32, png_get_y_offset_microns,  |
| 1937 | (png_const_structrp png_ptr, png_const_inforp info_ptr));  |
| 1938 |   |
| 1939 | #endif /* EASY_ACCESS */  |
| 1940 |   |
| 1941 | #ifdef PNG_READ_SUPPORTED  |
| 1942 | /* Returns pointer to signature string read from PNG header */  |
| 1943 | PNG_EXPORT(130, png_const_bytep, png_get_signature, (png_const_structrp png_ptr,  |
| 1944 | png_const_inforp info_ptr));  |
| 1945 | #endif  |
| 1946 |   |
| 1947 | #ifdef PNG_bKGD_SUPPORTED  |
| 1948 | PNG_EXPORT(131, png_uint_32, png_get_bKGD, (png_const_structrp png_ptr,  |
| 1949 | png_inforp info_ptr, png_color_16p *background));  |
| 1950 | #endif  |
| 1951 |   |
| 1952 | #ifdef PNG_bKGD_SUPPORTED  |
| 1953 | PNG_EXPORT(132, void, png_set_bKGD, (png_const_structrp png_ptr,  |
| 1954 | png_inforp info_ptr, png_const_color_16p background));  |
| 1955 | #endif  |
| 1956 |   |
| 1957 | #ifdef PNG_cHRM_SUPPORTED  |
| 1958 | PNG_FP_EXPORT(133, png_uint_32, png_get_cHRM, (png_const_structrp png_ptr,  |
| 1959 | png_const_inforp info_ptr, double *white_x, double *white_y, double *red_x,  |
| 1960 | double *red_y, double *green_x, double *green_y, double *blue_x,  |
| 1961 | double *blue_y))  |
| 1962 | PNG_FP_EXPORT(230, png_uint_32, png_get_cHRM_XYZ, (png_const_structrp png_ptr,  |
| 1963 | png_const_inforp info_ptr, double *red_X, double *red_Y, double *red_Z,  |
| 1964 | double *green_X, double *green_Y, double *green_Z, double *blue_X,  |
| 1965 | double *blue_Y, double *blue_Z))  |
| 1966 | PNG_FIXED_EXPORT(134, png_uint_32, png_get_cHRM_fixed,  |
| 1967 | (png_const_structrp png_ptr, png_const_inforp info_ptr,  |
| 1968 | png_fixed_point *int_white_x, png_fixed_point *int_white_y,  |
| 1969 | png_fixed_point *int_red_x, png_fixed_point *int_red_y,  |
| 1970 | png_fixed_point *int_green_x, png_fixed_point *int_green_y,  |
| 1971 | png_fixed_point *int_blue_x, png_fixed_point *int_blue_y))  |
| 1972 | PNG_FIXED_EXPORT(231, png_uint_32, png_get_cHRM_XYZ_fixed,  |
| 1973 | (png_const_structrp png_ptr, png_const_inforp info_ptr,  |
| 1974 | png_fixed_point *int_red_X, png_fixed_point *int_red_Y,  |
| 1975 | png_fixed_point *int_red_Z, png_fixed_point *int_green_X,  |
| 1976 | png_fixed_point *int_green_Y, png_fixed_point *int_green_Z,  |
| 1977 | png_fixed_point *int_blue_X, png_fixed_point *int_blue_Y,  |
| 1978 | png_fixed_point *int_blue_Z))  |
| 1979 | #endif  |
| 1980 |   |
| 1981 | #ifdef PNG_cHRM_SUPPORTED  |
| 1982 | PNG_FP_EXPORT(135, void, png_set_cHRM, (png_const_structrp png_ptr,  |
| 1983 | png_inforp info_ptr,  |
| 1984 | double white_x, double white_y, double red_x, double red_y, double green_x,  |
| 1985 | double green_y, double blue_x, double blue_y))  |
| 1986 | PNG_FP_EXPORT(232, void, png_set_cHRM_XYZ, (png_const_structrp png_ptr,  |
| 1987 | png_inforp info_ptr, double red_X, double red_Y, double red_Z,  |
| 1988 | double green_X, double green_Y, double green_Z, double blue_X,  |
| 1989 | double blue_Y, double blue_Z))  |
| 1990 | PNG_FIXED_EXPORT(136, void, png_set_cHRM_fixed, (png_const_structrp png_ptr,  |
| 1991 | png_inforp info_ptr, png_fixed_point int_white_x,  |
| 1992 | png_fixed_point int_white_y, png_fixed_point int_red_x,  |
| 1993 | png_fixed_point int_red_y, png_fixed_point int_green_x,  |
| 1994 | png_fixed_point int_green_y, png_fixed_point int_blue_x,  |
| 1995 | png_fixed_point int_blue_y))  |
| 1996 | PNG_FIXED_EXPORT(233, void, png_set_cHRM_XYZ_fixed, (png_const_structrp png_ptr,  |
| 1997 | png_inforp info_ptr, png_fixed_point int_red_X, png_fixed_point int_red_Y,  |
| 1998 | png_fixed_point int_red_Z, png_fixed_point int_green_X,  |
| 1999 | png_fixed_point int_green_Y, png_fixed_point int_green_Z,  |
| 2000 | png_fixed_point int_blue_X, png_fixed_point int_blue_Y,  |
| 2001 | png_fixed_point int_blue_Z))  |
| 2002 | #endif  |
| 2003 |   |
| 2004 | #ifdef PNG_eXIf_SUPPORTED  |
| 2005 | PNG_EXPORT(246, png_uint_32, png_get_eXIf, (png_const_structrp png_ptr,  |
| 2006 | png_inforp info_ptr, png_bytep *exif));  |
| 2007 | PNG_EXPORT(247, void, png_set_eXIf, (png_const_structrp png_ptr,  |
| 2008 | png_inforp info_ptr, png_bytep exif));  |
| 2009 |   |
| 2010 | PNG_EXPORT(248, png_uint_32, png_get_eXIf_1, (png_const_structrp png_ptr,  |
| 2011 | png_const_inforp info_ptr, png_uint_32 *num_exif, png_bytep *exif));  |
| 2012 | PNG_EXPORT(249, void, png_set_eXIf_1, (png_const_structrp png_ptr,  |
| 2013 | png_inforp info_ptr, png_uint_32 num_exif, png_bytep exif));  |
| 2014 | #endif  |
| 2015 |   |
| 2016 | #ifdef PNG_gAMA_SUPPORTED  |
| 2017 | PNG_FP_EXPORT(137, png_uint_32, png_get_gAMA, (png_const_structrp png_ptr,  |
| 2018 | png_const_inforp info_ptr, double *file_gamma))  |
| 2019 | PNG_FIXED_EXPORT(138, png_uint_32, png_get_gAMA_fixed,  |
| 2020 | (png_const_structrp png_ptr, png_const_inforp info_ptr,  |
| 2021 | png_fixed_point *int_file_gamma))  |
| 2022 | #endif  |
| 2023 |   |
| 2024 | #ifdef PNG_gAMA_SUPPORTED  |
| 2025 | PNG_FP_EXPORT(139, void, png_set_gAMA, (png_const_structrp png_ptr,  |
| 2026 | png_inforp info_ptr, double file_gamma))  |
| 2027 | PNG_FIXED_EXPORT(140, void, png_set_gAMA_fixed, (png_const_structrp png_ptr,  |
| 2028 | png_inforp info_ptr, png_fixed_point int_file_gamma))  |
| 2029 | #endif  |
| 2030 |   |
| 2031 | #ifdef PNG_hIST_SUPPORTED  |
| 2032 | PNG_EXPORT(141, png_uint_32, png_get_hIST, (png_const_structrp png_ptr,  |
| 2033 | png_inforp info_ptr, png_uint_16p *hist));  |
| 2034 | PNG_EXPORT(142, void, png_set_hIST, (png_const_structrp png_ptr,  |
| 2035 | png_inforp info_ptr, png_const_uint_16p hist));  |
| 2036 | #endif  |
| 2037 |   |
| 2038 | PNG_EXPORT(143, png_uint_32, png_get_IHDR, (png_const_structrp png_ptr,  |
| 2039 | png_const_inforp info_ptr, png_uint_32 *width, png_uint_32 *height,  |
| 2040 | int *bit_depth, int *color_type, int *interlace_method,  |
| 2041 | int *compression_method, int *filter_method));  |
| 2042 |   |
| 2043 | PNG_EXPORT(144, void, png_set_IHDR, (png_const_structrp png_ptr,  |
| 2044 | png_inforp info_ptr, png_uint_32 width, png_uint_32 height, int bit_depth,  |
| 2045 | int color_type, int interlace_method, int compression_method,  |
| 2046 | int filter_method));  |
| 2047 |   |
| 2048 | #ifdef PNG_oFFs_SUPPORTED  |
| 2049 | PNG_EXPORT(145, png_uint_32, png_get_oFFs, (png_const_structrp png_ptr,  |
| 2050 | png_const_inforp info_ptr, png_int_32 *offset_x, png_int_32 *offset_y,  |
| 2051 | int *unit_type));  |
| 2052 | #endif  |
| 2053 |   |
| 2054 | #ifdef PNG_oFFs_SUPPORTED  |
| 2055 | PNG_EXPORT(146, void, png_set_oFFs, (png_const_structrp png_ptr,  |
| 2056 | png_inforp info_ptr, png_int_32 offset_x, png_int_32 offset_y,  |
| 2057 | int unit_type));  |
| 2058 | #endif  |
| 2059 |   |
| 2060 | #ifdef PNG_pCAL_SUPPORTED  |
| 2061 | PNG_EXPORT(147, png_uint_32, png_get_pCAL, (png_const_structrp png_ptr,  |
| 2062 | png_inforp info_ptr, png_charp *purpose, png_int_32 *X0,  |
| 2063 | png_int_32 *X1, int *type, int *nparams, png_charp *units,  |
| 2064 | png_charpp *params));  |
| 2065 | #endif  |
| 2066 |   |
| 2067 | #ifdef PNG_pCAL_SUPPORTED  |
| 2068 | PNG_EXPORT(148, void, png_set_pCAL, (png_const_structrp png_ptr,  |
| 2069 | png_inforp info_ptr, png_const_charp purpose, png_int_32 X0, png_int_32 X1,  |
| 2070 | int type, int nparams, png_const_charp units, png_charpp params));  |
| 2071 | #endif  |
| 2072 |   |
| 2073 | #ifdef PNG_pHYs_SUPPORTED  |
| 2074 | PNG_EXPORT(149, png_uint_32, png_get_pHYs, (png_const_structrp png_ptr,  |
| 2075 | png_const_inforp info_ptr, png_uint_32 *res_x, png_uint_32 *res_y,  |
| 2076 | int *unit_type));  |
| 2077 | #endif  |
| 2078 |   |
| 2079 | #ifdef PNG_pHYs_SUPPORTED  |
| 2080 | PNG_EXPORT(150, void, png_set_pHYs, (png_const_structrp png_ptr,  |
| 2081 | png_inforp info_ptr, png_uint_32 res_x, png_uint_32 res_y, int unit_type));  |
| 2082 | #endif  |
| 2083 |   |
| 2084 | PNG_EXPORT(151, png_uint_32, png_get_PLTE, (png_const_structrp png_ptr,  |
| 2085 | png_inforp info_ptr, png_colorp *palette, int *num_palette));  |
| 2086 |   |
| 2087 | PNG_EXPORT(152, void, png_set_PLTE, (png_structrp png_ptr,  |
| 2088 | png_inforp info_ptr, png_const_colorp palette, int num_palette));  |
| 2089 |   |
| 2090 | #ifdef PNG_sBIT_SUPPORTED  |
| 2091 | PNG_EXPORT(153, png_uint_32, png_get_sBIT, (png_const_structrp png_ptr,  |
| 2092 | png_inforp info_ptr, png_color_8p *sig_bit));  |
| 2093 | #endif  |
| 2094 |   |
| 2095 | #ifdef PNG_sBIT_SUPPORTED  |
| 2096 | PNG_EXPORT(154, void, png_set_sBIT, (png_const_structrp png_ptr,  |
| 2097 | png_inforp info_ptr, png_const_color_8p sig_bit));  |
| 2098 | #endif  |
| 2099 |   |
| 2100 | #ifdef PNG_sRGB_SUPPORTED  |
| 2101 | PNG_EXPORT(155, png_uint_32, png_get_sRGB, (png_const_structrp png_ptr,  |
| 2102 | png_const_inforp info_ptr, int *file_srgb_intent));  |
| 2103 | #endif  |
| 2104 |   |
| 2105 | #ifdef PNG_sRGB_SUPPORTED  |
| 2106 | PNG_EXPORT(156, void, png_set_sRGB, (png_const_structrp png_ptr,  |
| 2107 | png_inforp info_ptr, int srgb_intent));  |
| 2108 | PNG_EXPORT(157, void, png_set_sRGB_gAMA_and_cHRM, (png_const_structrp png_ptr,  |
| 2109 | png_inforp info_ptr, int srgb_intent));  |
| 2110 | #endif  |
| 2111 |   |
| 2112 | #ifdef PNG_iCCP_SUPPORTED  |
| 2113 | PNG_EXPORT(158, png_uint_32, png_get_iCCP, (png_const_structrp png_ptr,  |
| 2114 | png_inforp info_ptr, png_charpp name, int *compression_type,  |
| 2115 | png_bytepp profile, png_uint_32 *proflen));  |
| 2116 | #endif  |
| 2117 |   |
| 2118 | #ifdef PNG_iCCP_SUPPORTED  |
| 2119 | PNG_EXPORT(159, void, png_set_iCCP, (png_const_structrp png_ptr,  |
| 2120 | png_inforp info_ptr, png_const_charp name, int compression_type,  |
| 2121 | png_const_bytep profile, png_uint_32 proflen));  |
| 2122 | #endif  |
| 2123 |   |
| 2124 | #ifdef PNG_sPLT_SUPPORTED  |
| 2125 | PNG_EXPORT(160, int, png_get_sPLT, (png_const_structrp png_ptr,  |
| 2126 | png_inforp info_ptr, png_sPLT_tpp entries));  |
| 2127 | #endif  |
| 2128 |   |
| 2129 | #ifdef PNG_sPLT_SUPPORTED  |
| 2130 | PNG_EXPORT(161, void, png_set_sPLT, (png_const_structrp png_ptr,  |
| 2131 | png_inforp info_ptr, png_const_sPLT_tp entries, int nentries));  |
| 2132 | #endif  |
| 2133 |   |
| 2134 | #ifdef PNG_TEXT_SUPPORTED  |
| 2135 | /* png_get_text also returns the number of text chunks in *num_text */  |
| 2136 | PNG_EXPORT(162, int, png_get_text, (png_const_structrp png_ptr,  |
| 2137 | png_inforp info_ptr, png_textp *text_ptr, int *num_text));  |
| 2138 | #endif  |
| 2139 |   |
| 2140 | /* Note while png_set_text() will accept a structure whose text,  |
| 2141 | * language, and translated keywords are NULL pointers, the structure  |
| 2142 | * returned by png_get_text will always contain regular  |
| 2143 | * zero-terminated C strings. They might be empty strings but  |
| 2144 | * they will never be NULL pointers.  |
| 2145 | */  |
| 2146 |   |
| 2147 | #ifdef PNG_TEXT_SUPPORTED  |
| 2148 | PNG_EXPORT(163, void, png_set_text, (png_const_structrp png_ptr,  |
| 2149 | png_inforp info_ptr, png_const_textp text_ptr, int num_text));  |
| 2150 | #endif  |
| 2151 |   |
| 2152 | #ifdef PNG_tIME_SUPPORTED  |
| 2153 | PNG_EXPORT(164, png_uint_32, png_get_tIME, (png_const_structrp png_ptr,  |
| 2154 | png_inforp info_ptr, png_timep *mod_time));  |
| 2155 | #endif  |
| 2156 |   |
| 2157 | #ifdef PNG_tIME_SUPPORTED  |
| 2158 | PNG_EXPORT(165, void, png_set_tIME, (png_const_structrp png_ptr,  |
| 2159 | png_inforp info_ptr, png_const_timep mod_time));  |
| 2160 | #endif  |
| 2161 |   |
| 2162 | #ifdef PNG_tRNS_SUPPORTED  |
| 2163 | PNG_EXPORT(166, png_uint_32, png_get_tRNS, (png_const_structrp png_ptr,  |
| 2164 | png_inforp info_ptr, png_bytep *trans_alpha, int *num_trans,  |
| 2165 | png_color_16p *trans_color));  |
| 2166 | #endif  |
| 2167 |   |
| 2168 | #ifdef PNG_tRNS_SUPPORTED  |
| 2169 | PNG_EXPORT(167, void, png_set_tRNS, (png_structrp png_ptr,  |
| 2170 | png_inforp info_ptr, png_const_bytep trans_alpha, int num_trans,  |
| 2171 | png_const_color_16p trans_color));  |
| 2172 | #endif  |
| 2173 |   |
| 2174 | #ifdef PNG_sCAL_SUPPORTED  |
| 2175 | PNG_FP_EXPORT(168, png_uint_32, png_get_sCAL, (png_const_structrp png_ptr,  |
| 2176 | png_const_inforp info_ptr, int *unit, double *width, double *height))  |
| 2177 | #if defined(PNG_FLOATING_ARITHMETIC_SUPPORTED) || \  |
| 2178 | defined(PNG_FLOATING_POINT_SUPPORTED)  |
| 2179 | /* NOTE: this API is currently implemented using floating point arithmetic,  |
| 2180 | * consequently it can only be used on systems with floating point support.  |
| 2181 | * In any case the range of values supported by png_fixed_point is small and it  |
| 2182 | * is highly recommended that png_get_sCAL_s be used instead.  |
| 2183 | */  |
| 2184 | PNG_FIXED_EXPORT(214, png_uint_32, png_get_sCAL_fixed,  |
| 2185 | (png_const_structrp png_ptr, png_const_inforp info_ptr, int *unit,  |
| 2186 | png_fixed_point *width, png_fixed_point *height))  |
| 2187 | #endif  |
| 2188 | PNG_EXPORT(169, png_uint_32, png_get_sCAL_s,  |
| 2189 | (png_const_structrp png_ptr, png_const_inforp info_ptr, int *unit,  |
| 2190 | png_charpp swidth, png_charpp sheight));  |
| 2191 |   |
| 2192 | PNG_FP_EXPORT(170, void, png_set_sCAL, (png_const_structrp png_ptr,  |
| 2193 | png_inforp info_ptr, int unit, double width, double height))  |
| 2194 | PNG_FIXED_EXPORT(213, void, png_set_sCAL_fixed, (png_const_structrp png_ptr,  |
| 2195 | png_inforp info_ptr, int unit, png_fixed_point width,  |
| 2196 | png_fixed_point height))  |
| 2197 | PNG_EXPORT(171, void, png_set_sCAL_s, (png_const_structrp png_ptr,  |
| 2198 | png_inforp info_ptr, int unit,  |
| 2199 | png_const_charp swidth, png_const_charp sheight));  |
| 2200 | #endif /* sCAL */  |
| 2201 |   |
| 2202 | #ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED  |
| 2203 | /* Provide the default handling for all unknown chunks or, optionally, for  |
| 2204 | * specific unknown chunks.  |
| 2205 | *  |
| 2206 | * NOTE: prior to 1.6.0 the handling specified for particular chunks on read was  |
| 2207 | * ignored and the default was used, the per-chunk setting only had an effect on  |
| 2208 | * write. If you wish to have chunk-specific handling on read in code that must  |
| 2209 | * work on earlier versions you must use a user chunk callback to specify the  |
| 2210 | * desired handling (keep or discard.)  |
| 2211 | *  |
| 2212 | * The 'keep' parameter is a PNG_HANDLE_CHUNK_ value as listed below. The  |
| 2213 | * parameter is interpreted as follows:  |
| 2214 | *  |
| 2215 | * READ:  |
| 2216 | * PNG_HANDLE_CHUNK_AS_DEFAULT:  |
| 2217 | * Known chunks: do normal libpng processing, do not keep the chunk (but  |
| 2218 | * see the comments below about PNG_HANDLE_AS_UNKNOWN_SUPPORTED)  |
| 2219 | * Unknown chunks: for a specific chunk use the global default, when used  |
| 2220 | * as the default discard the chunk data.  |
| 2221 | * PNG_HANDLE_CHUNK_NEVER:  |
| 2222 | * Discard the chunk data.  |
| 2223 | * PNG_HANDLE_CHUNK_IF_SAFE:  |
| 2224 | * Keep the chunk data if the chunk is not critical else raise a chunk  |
| 2225 | * error.  |
| 2226 | * PNG_HANDLE_CHUNK_ALWAYS:  |
| 2227 | * Keep the chunk data.  |
| 2228 | *  |
| 2229 | * If the chunk data is saved it can be retrieved using png_get_unknown_chunks,  |
| 2230 | * below. Notice that specifying "AS_DEFAULT" as a global default is equivalent  |
| 2231 | * to specifying "NEVER", however when "AS_DEFAULT" is used for specific chunks  |
| 2232 | * it simply resets the behavior to the libpng default.  |
| 2233 | *  |
| 2234 | * INTERACTION WITH USER CHUNK CALLBACKS:  |
| 2235 | * The per-chunk handling is always used when there is a png_user_chunk_ptr  |
| 2236 | * callback and the callback returns 0; the chunk is then always stored *unless*  |
| 2237 | * it is critical and the per-chunk setting is other than ALWAYS. Notice that  |
| 2238 | * the global default is *not* used in this case. (In effect the per-chunk  |
| 2239 | * value is incremented to at least IF_SAFE.)  |
| 2240 | *  |
| 2241 | * IMPORTANT NOTE: this behavior will change in libpng 1.7 - the global and  |
| 2242 | * per-chunk defaults will be honored. If you want to preserve the current  |
| 2243 | * behavior when your callback returns 0 you must set PNG_HANDLE_CHUNK_IF_SAFE  |
| 2244 | * as the default - if you don't do this libpng 1.6 will issue a warning.  |
| 2245 | *  |
| 2246 | * If you want unhandled unknown chunks to be discarded in libpng 1.6 and  |
| 2247 | * earlier simply return '1' (handled).  |
| 2248 | *  |
| 2249 | * PNG_HANDLE_AS_UNKNOWN_SUPPORTED:  |
| 2250 | * If this is *not* set known chunks will always be handled by libpng and  |
| 2251 | * will never be stored in the unknown chunk list. Known chunks listed to  |
| 2252 | * png_set_keep_unknown_chunks will have no effect. If it is set then known  |
| 2253 | * chunks listed with a keep other than AS_DEFAULT will *never* be processed  |
| 2254 | * by libpng, in addition critical chunks must either be processed by the  |
| 2255 | * callback or saved.  |
| 2256 | *  |
| 2257 | * The IHDR and IEND chunks must not be listed. Because this turns off the  |
| 2258 | * default handling for chunks that would otherwise be recognized the  |
| 2259 | * behavior of libpng transformations may well become incorrect!  |
| 2260 | *  |
| 2261 | * WRITE:  |
| 2262 | * When writing chunks the options only apply to the chunks specified by  |
| 2263 | * png_set_unknown_chunks (below), libpng will *always* write known chunks  |
| 2264 | * required by png_set_ calls and will always write the core critical chunks  |
| 2265 | * (as required for PLTE).  |
| 2266 | *  |
| 2267 | * Each chunk in the png_set_unknown_chunks list is looked up in the  |
| 2268 | * png_set_keep_unknown_chunks list to find the keep setting, this is then  |
| 2269 | * interpreted as follows:  |
| 2270 | *  |
| 2271 | * PNG_HANDLE_CHUNK_AS_DEFAULT:  |
| 2272 | * Write safe-to-copy chunks and write other chunks if the global  |
| 2273 | * default is set to _ALWAYS, otherwise don't write this chunk.  |
| 2274 | * PNG_HANDLE_CHUNK_NEVER:  |
| 2275 | * Do not write the chunk.  |
| 2276 | * PNG_HANDLE_CHUNK_IF_SAFE:  |
| 2277 | * Write the chunk if it is safe-to-copy, otherwise do not write it.  |
| 2278 | * PNG_HANDLE_CHUNK_ALWAYS:  |
| 2279 | * Write the chunk.  |
| 2280 | *  |
| 2281 | * Note that the default behavior is effectively the opposite of the read case -  |
| 2282 | * in read unknown chunks are not stored by default, in write they are written  |
| 2283 | * by default. Also the behavior of PNG_HANDLE_CHUNK_IF_SAFE is very different  |
| 2284 | * - on write the safe-to-copy bit is checked, on read the critical bit is  |
| 2285 | * checked and on read if the chunk is critical an error will be raised.  |
| 2286 | *  |
| 2287 | * num_chunks:  |
| 2288 | * ===========  |
| 2289 | * If num_chunks is positive, then the "keep" parameter specifies the manner  |
| 2290 | * for handling only those chunks appearing in the chunk_list array,  |
| 2291 | * otherwise the chunk list array is ignored.  |
| 2292 | *  |
| 2293 | * If num_chunks is 0 the "keep" parameter specifies the default behavior for  |
| 2294 | * unknown chunks, as described above.  |
| 2295 | *  |
| 2296 | * If num_chunks is negative, then the "keep" parameter specifies the manner  |
| 2297 | * for handling all unknown chunks plus all chunks recognized by libpng  |
| 2298 | * except for the IHDR, PLTE, tRNS, IDAT, and IEND chunks (which continue to  |
| 2299 | * be processed by libpng.  |
| 2300 | */  |
| 2301 | #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED  |
| 2302 | PNG_EXPORT(172, void, png_set_keep_unknown_chunks, (png_structrp png_ptr,  |
| 2303 | int keep, png_const_bytep chunk_list, int num_chunks));  |
| 2304 | #endif /* HANDLE_AS_UNKNOWN */  |
| 2305 |   |
| 2306 | /* The "keep" PNG_HANDLE_CHUNK_ parameter for the specified chunk is returned;  |
| 2307 | * the result is therefore true (non-zero) if special handling is required,  |
| 2308 | * false for the default handling.  |
| 2309 | */  |
| 2310 | PNG_EXPORT(173, int, png_handle_as_unknown, (png_const_structrp png_ptr,  |
| 2311 | png_const_bytep chunk_name));  |
| 2312 | #endif /* SET_UNKNOWN_CHUNKS */  |
| 2313 |   |
| 2314 | #ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED  |
| 2315 | PNG_EXPORT(174, void, png_set_unknown_chunks, (png_const_structrp png_ptr,  |
| 2316 | png_inforp info_ptr, png_const_unknown_chunkp unknowns,  |
| 2317 | int num_unknowns));  |
| 2318 | /* NOTE: prior to 1.6.0 this routine set the 'location' field of the added  |
| 2319 | * unknowns to the location currently stored in the png_struct. This is  |
| 2320 | * invariably the wrong value on write. To fix this call the following API  |
| 2321 | * for each chunk in the list with the correct location. If you know your  |
| 2322 | * code won't be compiled on earlier versions you can rely on  |
| 2323 | * png_set_unknown_chunks(write-ptr, png_get_unknown_chunks(read-ptr)) doing  |
| 2324 | * the correct thing.  |
| 2325 | */  |
| 2326 |   |
| 2327 | PNG_EXPORT(175, void, png_set_unknown_chunk_location,  |
| 2328 | (png_const_structrp png_ptr, png_inforp info_ptr, int chunk, int location));  |
| 2329 |   |
| 2330 | PNG_EXPORT(176, int, png_get_unknown_chunks, (png_const_structrp png_ptr,  |
| 2331 | png_inforp info_ptr, png_unknown_chunkpp entries));  |
| 2332 | #endif  |
| 2333 |   |
| 2334 | /* Png_free_data() will turn off the "valid" flag for anything it frees.  |
| 2335 | * If you need to turn it off for a chunk that your application has freed,  |
| 2336 | * you can use png_set_invalid(png_ptr, info_ptr, PNG_INFO_CHNK);  |
| 2337 | */  |
| 2338 | PNG_EXPORT(177, void, png_set_invalid, (png_const_structrp png_ptr,  |
| 2339 | png_inforp info_ptr, int mask));  |
| 2340 |   |
| 2341 | #ifdef PNG_INFO_IMAGE_SUPPORTED  |
| 2342 | /* The "params" pointer is currently not used and is for future expansion. */  |
| 2343 | #ifdef PNG_SEQUENTIAL_READ_SUPPORTED  |
| 2344 | PNG_EXPORT(178, void, png_read_png, (png_structrp png_ptr, png_inforp info_ptr,  |
| 2345 | int transforms, png_voidp params));  |
| 2346 | #endif  |
| 2347 | #ifdef PNG_WRITE_SUPPORTED  |
| 2348 | PNG_EXPORT(179, void, png_write_png, (png_structrp png_ptr, png_inforp info_ptr,  |
| 2349 | int transforms, png_voidp params));  |
| 2350 | #endif  |
| 2351 | #endif  |
| 2352 |   |
| 2353 | PNG_EXPORT(180, png_const_charp, png_get_copyright,  |
| 2354 | (png_const_structrp png_ptr));  |
| 2355 | PNG_EXPORT(181, png_const_charp, ,  |
| 2356 | (png_const_structrp png_ptr));  |
| 2357 | PNG_EXPORT(182, png_const_charp, ,  |
| 2358 | (png_const_structrp png_ptr));  |
| 2359 | PNG_EXPORT(183, png_const_charp, png_get_libpng_ver,  |
| 2360 | (png_const_structrp png_ptr));  |
| 2361 |   |
| 2362 | #ifdef PNG_MNG_FEATURES_SUPPORTED  |
| 2363 | PNG_EXPORT(184, png_uint_32, png_permit_mng_features, (png_structrp png_ptr,  |
| 2364 | png_uint_32 mng_features_permitted));  |
| 2365 | #endif  |
| 2366 |   |
| 2367 | /* For use in png_set_keep_unknown, added to version 1.2.6 */  |
| 2368 | #define PNG_HANDLE_CHUNK_AS_DEFAULT 0  |
| 2369 | #define PNG_HANDLE_CHUNK_NEVER 1  |
| 2370 | #define PNG_HANDLE_CHUNK_IF_SAFE 2  |
| 2371 | #define PNG_HANDLE_CHUNK_ALWAYS 3  |
| 2372 | #define PNG_HANDLE_CHUNK_LAST 4  |
| 2373 |   |
| 2374 | /* Strip the prepended error numbers ("#nnn ") from error and warning  |
| 2375 | * messages before passing them to the error or warning handler.  |
| 2376 | */  |
| 2377 | #ifdef PNG_ERROR_NUMBERS_SUPPORTED  |
| 2378 | PNG_EXPORT(185, void, png_set_strip_error_numbers, (png_structrp png_ptr,  |
| 2379 | png_uint_32 strip_mode));  |
| 2380 | #endif  |
| 2381 |   |
| 2382 | /* Added in libpng-1.2.6 */  |
| 2383 | #ifdef PNG_SET_USER_LIMITS_SUPPORTED  |
| 2384 | PNG_EXPORT(186, void, png_set_user_limits, (png_structrp png_ptr,  |
| 2385 | png_uint_32 user_width_max, png_uint_32 user_height_max));  |
| 2386 | PNG_EXPORT(187, png_uint_32, png_get_user_width_max,  |
| 2387 | (png_const_structrp png_ptr));  |
| 2388 | PNG_EXPORT(188, png_uint_32, png_get_user_height_max,  |
| 2389 | (png_const_structrp png_ptr));  |
| 2390 | /* Added in libpng-1.4.0 */  |
| 2391 | PNG_EXPORT(189, void, png_set_chunk_cache_max, (png_structrp png_ptr,  |
| 2392 | png_uint_32 user_chunk_cache_max));  |
| 2393 | PNG_EXPORT(190, png_uint_32, png_get_chunk_cache_max,  |
| 2394 | (png_const_structrp png_ptr));  |
| 2395 | /* Added in libpng-1.4.1 */  |
| 2396 | PNG_EXPORT(191, void, png_set_chunk_malloc_max, (png_structrp png_ptr,  |
| 2397 | png_alloc_size_t user_chunk_cache_max));  |
| 2398 | PNG_EXPORT(192, png_alloc_size_t, png_get_chunk_malloc_max,  |
| 2399 | (png_const_structrp png_ptr));  |
| 2400 | #endif  |
| 2401 |   |
| 2402 | #if defined(PNG_INCH_CONVERSIONS_SUPPORTED)  |
| 2403 | PNG_EXPORT(193, png_uint_32, png_get_pixels_per_inch,  |
| 2404 | (png_const_structrp png_ptr, png_const_inforp info_ptr));  |
| 2405 |   |
| 2406 | PNG_EXPORT(194, png_uint_32, png_get_x_pixels_per_inch,  |
| 2407 | (png_const_structrp png_ptr, png_const_inforp info_ptr));  |
| 2408 |   |
| 2409 | PNG_EXPORT(195, png_uint_32, png_get_y_pixels_per_inch,  |
| 2410 | (png_const_structrp png_ptr, png_const_inforp info_ptr));  |
| 2411 |   |
| 2412 | PNG_FP_EXPORT(196, float, png_get_x_offset_inches,  |
| 2413 | (png_const_structrp png_ptr, png_const_inforp info_ptr))  |
| 2414 | #ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */  |
| 2415 | PNG_FIXED_EXPORT(211, png_fixed_point, png_get_x_offset_inches_fixed,  |
| 2416 | (png_const_structrp png_ptr, png_const_inforp info_ptr))  |
| 2417 | #endif  |
| 2418 |   |
| 2419 | PNG_FP_EXPORT(197, float, png_get_y_offset_inches, (png_const_structrp png_ptr,  |
| 2420 | png_const_inforp info_ptr))  |
| 2421 | #ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */  |
| 2422 | PNG_FIXED_EXPORT(212, png_fixed_point, png_get_y_offset_inches_fixed,  |
| 2423 | (png_const_structrp png_ptr, png_const_inforp info_ptr))  |
| 2424 | #endif  |
| 2425 |   |
| 2426 | # ifdef PNG_pHYs_SUPPORTED  |
| 2427 | PNG_EXPORT(198, png_uint_32, png_get_pHYs_dpi, (png_const_structrp png_ptr,  |
| 2428 | png_const_inforp info_ptr, png_uint_32 *res_x, png_uint_32 *res_y,  |
| 2429 | int *unit_type));  |
| 2430 | # endif /* pHYs */  |
| 2431 | #endif /* INCH_CONVERSIONS */  |
| 2432 |   |
| 2433 | /* Added in libpng-1.4.0 */  |
| 2434 | #ifdef PNG_IO_STATE_SUPPORTED  |
| 2435 | PNG_EXPORT(199, png_uint_32, png_get_io_state, (png_const_structrp png_ptr));  |
| 2436 |   |
| 2437 | /* Removed from libpng 1.6; use png_get_io_chunk_type. */  |
| 2438 | PNG_REMOVED(200, png_const_bytep, png_get_io_chunk_name, (png_structrp png_ptr),  |
| 2439 | PNG_DEPRECATED)  |
| 2440 |   |
| 2441 | PNG_EXPORT(216, png_uint_32, png_get_io_chunk_type,  |
| 2442 | (png_const_structrp png_ptr));  |
| 2443 |   |
| 2444 | /* The flags returned by png_get_io_state() are the following: */  |
| 2445 | # define PNG_IO_NONE 0x0000 /* no I/O at this moment */  |
| 2446 | # define PNG_IO_READING 0x0001 /* currently reading */  |
| 2447 | # define PNG_IO_WRITING 0x0002 /* currently writing */  |
| 2448 | # define PNG_IO_SIGNATURE 0x0010 /* currently at the file signature */  |
| 2449 | # define PNG_IO_CHUNK_HDR 0x0020 /* currently at the chunk header */  |
| 2450 | # define PNG_IO_CHUNK_DATA 0x0040 /* currently at the chunk data */  |
| 2451 | # define PNG_IO_CHUNK_CRC 0x0080 /* currently at the chunk crc */  |
| 2452 | # define PNG_IO_MASK_OP 0x000f /* current operation: reading/writing */  |
| 2453 | # define PNG_IO_MASK_LOC 0x00f0 /* current location: sig/hdr/data/crc */  |
| 2454 | #endif /* IO_STATE */  |
| 2455 |   |
| 2456 | /* Interlace support. The following macros are always defined so that if  |
| 2457 | * libpng interlace handling is turned off the macros may be used to handle  |
| 2458 | * interlaced images within the application.  |
| 2459 | */  |
| 2460 | #define PNG_INTERLACE_ADAM7_PASSES 7  |
| 2461 |   |
| 2462 | /* Two macros to return the first row and first column of the original,  |
| 2463 | * full, image which appears in a given pass. 'pass' is in the range 0  |
| 2464 | * to 6 and the result is in the range 0 to 7.  |
| 2465 | */  |
| 2466 | #define PNG_PASS_START_ROW(pass) (((1&~(pass))<<(3-((pass)>>1)))&7)  |
| 2467 | #define PNG_PASS_START_COL(pass) (((1& (pass))<<(3-(((pass)+1)>>1)))&7)  |
| 2468 |   |
| 2469 | /* A macro to return the offset between pixels in the output row for a pair of  |
| 2470 | * pixels in the input - effectively the inverse of the 'COL_SHIFT' macro that  |
| 2471 | * follows. Note that ROW_OFFSET is the offset from one row to the next whereas  |
| 2472 | * COL_OFFSET is from one column to the next, within a row.  |
| 2473 | */  |
| 2474 | #define PNG_PASS_ROW_OFFSET(pass) ((pass)>2?(8>>(((pass)-1)>>1)):8)  |
| 2475 | #define PNG_PASS_COL_OFFSET(pass) (1<<((7-(pass))>>1))  |
| 2476 |   |
| 2477 | /* Two macros to help evaluate the number of rows or columns in each  |
| 2478 | * pass. This is expressed as a shift - effectively log2 of the number or  |
| 2479 | * rows or columns in each 8x8 tile of the original image.  |
| 2480 | */  |
| 2481 | #define PNG_PASS_ROW_SHIFT(pass) ((pass)>2?(8-(pass))>>1:3)  |
| 2482 | #define PNG_PASS_COL_SHIFT(pass) ((pass)>1?(7-(pass))>>1:3)  |
| 2483 |   |
| 2484 | /* Hence two macros to determine the number of rows or columns in a given  |
| 2485 | * pass of an image given its height or width. In fact these macros may  |
| 2486 | * return non-zero even though the sub-image is empty, because the other  |
| 2487 | * dimension may be empty for a small image.  |
| 2488 | */  |
| 2489 | #define PNG_PASS_ROWS(height, pass) (((height)+(((1<<PNG_PASS_ROW_SHIFT(pass))\  |
| 2490 | -1)-PNG_PASS_START_ROW(pass)))>>PNG_PASS_ROW_SHIFT(pass))  |
| 2491 | #define PNG_PASS_COLS(width, pass) (((width)+(((1<<PNG_PASS_COL_SHIFT(pass))\  |
| 2492 | -1)-PNG_PASS_START_COL(pass)))>>PNG_PASS_COL_SHIFT(pass))  |
| 2493 |   |
| 2494 | /* For the reader row callbacks (both progressive and sequential) it is  |
| 2495 | * necessary to find the row in the output image given a row in an interlaced  |
| 2496 | * image, so two more macros:  |
| 2497 | */  |
| 2498 | #define PNG_ROW_FROM_PASS_ROW(y_in, pass) \  |
| 2499 | (((y_in)<<PNG_PASS_ROW_SHIFT(pass))+PNG_PASS_START_ROW(pass))  |
| 2500 | #define PNG_COL_FROM_PASS_COL(x_in, pass) \  |
| 2501 | (((x_in)<<PNG_PASS_COL_SHIFT(pass))+PNG_PASS_START_COL(pass))  |
| 2502 |   |
| 2503 | /* Two macros which return a boolean (0 or 1) saying whether the given row  |
| 2504 | * or column is in a particular pass. These use a common utility macro that  |
| 2505 | * returns a mask for a given pass - the offset 'off' selects the row or  |
| 2506 | * column version. The mask has the appropriate bit set for each column in  |
| 2507 | * the tile.  |
| 2508 | */  |
| 2509 | #define PNG_PASS_MASK(pass,off) ( \  |
| 2510 | ((0x110145AF>>(((7-(off))-(pass))<<2)) & 0xF) | \  |
| 2511 | ((0x01145AF0>>(((7-(off))-(pass))<<2)) & 0xF0))  |
| 2512 |   |
| 2513 | #define PNG_ROW_IN_INTERLACE_PASS(y, pass) \  |
| 2514 | ((PNG_PASS_MASK(pass,0) >> ((y)&7)) & 1)  |
| 2515 | #define PNG_COL_IN_INTERLACE_PASS(x, pass) \  |
| 2516 | ((PNG_PASS_MASK(pass,1) >> ((x)&7)) & 1)  |
| 2517 |   |
| 2518 | #ifdef PNG_READ_COMPOSITE_NODIV_SUPPORTED  |
| 2519 | /* With these routines we avoid an integer divide, which will be slower on  |
| 2520 | * most machines. However, it does take more operations than the corresponding  |
| 2521 | * divide method, so it may be slower on a few RISC systems. There are two  |
| 2522 | * shifts (by 8 or 16 bits) and an addition, versus a single integer divide.  |
| 2523 | *  |
| 2524 | * Note that the rounding factors are NOT supposed to be the same! 128 and  |
| 2525 | * 32768 are correct for the NODIV code; 127 and 32767 are correct for the  |
| 2526 | * standard method.  |
| 2527 | *  |
| 2528 | * [Optimized code by Greg Roelofs and Mark Adler...blame us for bugs. :-) ]  |
| 2529 | */  |
| 2530 |   |
| 2531 | /* fg and bg should be in `gamma 1.0' space; alpha is the opacity */  |
| 2532 |   |
| 2533 | # define png_composite(composite, fg, alpha, bg) \  |
| 2534 | { \  |
| 2535 | png_uint_16 temp = (png_uint_16)((png_uint_16)(fg) \  |
| 2536 | * (png_uint_16)(alpha) \  |
| 2537 | + (png_uint_16)(bg)*(png_uint_16)(255 \  |
| 2538 | - (png_uint_16)(alpha)) + 128); \  |
| 2539 | (composite) = (png_byte)(((temp + (temp >> 8)) >> 8) & 0xff); \  |
| 2540 | }  |
| 2541 |   |
| 2542 | # define png_composite_16(composite, fg, alpha, bg) \  |
| 2543 | { \  |
| 2544 | png_uint_32 temp = (png_uint_32)((png_uint_32)(fg) \  |
| 2545 | * (png_uint_32)(alpha) \  |
| 2546 | + (png_uint_32)(bg)*(65535 \  |
| 2547 | - (png_uint_32)(alpha)) + 32768); \  |
| 2548 | (composite) = (png_uint_16)(0xffff & ((temp + (temp >> 16)) >> 16)); \  |
| 2549 | }  |
| 2550 |   |
| 2551 | #else /* Standard method using integer division */  |
| 2552 |   |
| 2553 | # define png_composite(composite, fg, alpha, bg) \  |
| 2554 | (composite) = \  |
| 2555 | (png_byte)(0xff & (((png_uint_16)(fg) * (png_uint_16)(alpha) + \  |
| 2556 | (png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) + \  |
| 2557 | 127) / 255))  |
| 2558 |   |
| 2559 | # define png_composite_16(composite, fg, alpha, bg) \  |
| 2560 | (composite) = \  |
| 2561 | (png_uint_16)(0xffff & (((png_uint_32)(fg) * (png_uint_32)(alpha) + \  |
| 2562 | (png_uint_32)(bg)*(png_uint_32)(65535 - (png_uint_32)(alpha)) + \  |
| 2563 | 32767) / 65535))  |
| 2564 | #endif /* READ_COMPOSITE_NODIV */  |
| 2565 |   |
| 2566 | #ifdef PNG_READ_INT_FUNCTIONS_SUPPORTED  |
| 2567 | PNG_EXPORT(201, png_uint_32, png_get_uint_32, (png_const_bytep buf));  |
| 2568 | PNG_EXPORT(202, png_uint_16, png_get_uint_16, (png_const_bytep buf));  |
| 2569 | PNG_EXPORT(203, png_int_32, png_get_int_32, (png_const_bytep buf));  |
| 2570 | #endif  |
| 2571 |   |
| 2572 | PNG_EXPORT(204, png_uint_32, png_get_uint_31, (png_const_structrp png_ptr,  |
| 2573 | png_const_bytep buf));  |
| 2574 | /* No png_get_int_16 -- may be added if there's a real need for it. */  |
| 2575 |   |
| 2576 | /* Place a 32-bit number into a buffer in PNG byte order (big-endian). */  |
| 2577 | #ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED  |
| 2578 | PNG_EXPORT(205, void, png_save_uint_32, (png_bytep buf, png_uint_32 i));  |
| 2579 | #endif  |
| 2580 | #ifdef PNG_SAVE_INT_32_SUPPORTED  |
| 2581 | PNG_EXPORT(206, void, png_save_int_32, (png_bytep buf, png_int_32 i));  |
| 2582 | #endif  |
| 2583 |   |
| 2584 | /* Place a 16-bit number into a buffer in PNG byte order.  |
| 2585 | * The parameter is declared unsigned int, not png_uint_16,  |
| 2586 | * just to avoid potential problems on pre-ANSI C compilers.  |
| 2587 | */  |
| 2588 | #ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED  |
| 2589 | PNG_EXPORT(207, void, png_save_uint_16, (png_bytep buf, unsigned int i));  |
| 2590 | /* No png_save_int_16 -- may be added if there's a real need for it. */  |
| 2591 | #endif  |
| 2592 |   |
| 2593 | #ifdef PNG_USE_READ_MACROS  |
| 2594 | /* Inline macros to do direct reads of bytes from the input buffer.  |
| 2595 | * The png_get_int_32() routine assumes we are using two's complement  |
| 2596 | * format for negative values, which is almost certainly true.  |
| 2597 | */  |
| 2598 | # define PNG_get_uint_32(buf) \  |
| 2599 | (((png_uint_32)(*(buf)) << 24) + \  |
| 2600 | ((png_uint_32)(*((buf) + 1)) << 16) + \  |
| 2601 | ((png_uint_32)(*((buf) + 2)) << 8) + \  |
| 2602 | ((png_uint_32)(*((buf) + 3))))  |
| 2603 |   |
| 2604 | /* From libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the  |
| 2605 | * function) incorrectly returned a value of type png_uint_32.  |
| 2606 | */  |
| 2607 | # define PNG_get_uint_16(buf) \  |
| 2608 | ((png_uint_16) \  |
| 2609 | (((unsigned int)(*(buf)) << 8) + \  |
| 2610 | ((unsigned int)(*((buf) + 1)))))  |
| 2611 |   |
| 2612 | # define PNG_get_int_32(buf) \  |
| 2613 | ((png_int_32)((*(buf) & 0x80) \  |
| 2614 | ? -((png_int_32)(((png_get_uint_32(buf)^0xffffffffU)+1U)&0x7fffffffU)) \  |
| 2615 | : (png_int_32)png_get_uint_32(buf)))  |
| 2616 |   |
| 2617 | /* If PNG_PREFIX is defined the same thing as below happens in pnglibconf.h,  |
| 2618 | * but defining a macro name prefixed with PNG_PREFIX.  |
| 2619 | */  |
| 2620 | # ifndef PNG_PREFIX  |
| 2621 | # define png_get_uint_32(buf) PNG_get_uint_32(buf)  |
| 2622 | # define png_get_uint_16(buf) PNG_get_uint_16(buf)  |
| 2623 | # define png_get_int_32(buf) PNG_get_int_32(buf)  |
| 2624 | # endif  |
| 2625 | #else  |
| 2626 | # ifdef PNG_PREFIX  |
| 2627 | /* No macros; revert to the (redefined) function */  |
| 2628 | # define PNG_get_uint_32 (png_get_uint_32)  |
| 2629 | # define PNG_get_uint_16 (png_get_uint_16)  |
| 2630 | # define PNG_get_int_32 (png_get_int_32)  |
| 2631 | # endif  |
| 2632 | #endif  |
| 2633 |   |
| 2634 | #ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED  |
| 2635 | PNG_EXPORT(242, void, png_set_check_for_invalid_index,  |
| 2636 | (png_structrp png_ptr, int allowed));  |
| 2637 | # ifdef PNG_GET_PALETTE_MAX_SUPPORTED  |
| 2638 | PNG_EXPORT(243, int, png_get_palette_max, (png_const_structp png_ptr,  |
| 2639 | png_const_infop info_ptr));  |
| 2640 | # endif  |
| 2641 | #endif /* CHECK_FOR_INVALID_INDEX */  |
| 2642 |   |
| 2643 | /*******************************************************************************  |
| 2644 | * Section 5: SIMPLIFIED API  |
| 2645 | *******************************************************************************  |
| 2646 | *  |
| 2647 | * Please read the documentation in libpng-manual.txt (TODO: write said  |
| 2648 | * documentation) if you don't understand what follows.  |
| 2649 | *  |
| 2650 | * The simplified API hides the details of both libpng and the PNG file format  |
| 2651 | * itself. It allows PNG files to be read into a very limited number of  |
| 2652 | * in-memory bitmap formats or to be written from the same formats. If these  |
| 2653 | * formats do not accommodate your needs then you can, and should, use the more  |
| 2654 | * sophisticated APIs above - these support a wide variety of in-memory formats  |
| 2655 | * and a wide variety of sophisticated transformations to those formats as well  |
| 2656 | * as a wide variety of APIs to manipulate ancillary information.  |
| 2657 | *  |
| 2658 | * To read a PNG file using the simplified API:  |
| 2659 | *  |
| 2660 | * 1) Declare a 'png_image' structure (see below) on the stack, set the  |
| 2661 | * version field to PNG_IMAGE_VERSION and the 'opaque' pointer to NULL  |
| 2662 | * (this is REQUIRED, your program may crash if you don't do it.)  |
| 2663 | * 2) Call the appropriate png_image_begin_read... function.  |
| 2664 | * 3) Set the png_image 'format' member to the required sample format.  |
| 2665 | * 4) Allocate a buffer for the image and, if required, the color-map.  |
| 2666 | * 5) Call png_image_finish_read to read the image and, if required, the  |
| 2667 | * color-map into your buffers.  |
| 2668 | *  |
| 2669 | * There are no restrictions on the format of the PNG input itself; all valid  |
| 2670 | * color types, bit depths, and interlace methods are acceptable, and the  |
| 2671 | * input image is transformed as necessary to the requested in-memory format  |
| 2672 | * during the png_image_finish_read() step. The only caveat is that if you  |
| 2673 | * request a color-mapped image from a PNG that is full-color or makes  |
| 2674 | * complex use of an alpha channel the transformation is extremely lossy and the  |
| 2675 | * result may look terrible.  |
| 2676 | *  |
| 2677 | * To write a PNG file using the simplified API:  |
| 2678 | *  |
| 2679 | * 1) Declare a 'png_image' structure on the stack and memset() it to all zero.  |
| 2680 | * 2) Initialize the members of the structure that describe the image, setting  |
| 2681 | * the 'format' member to the format of the image samples.  |
| 2682 | * 3) Call the appropriate png_image_write... function with a pointer to the  |
| 2683 | * image and, if necessary, the color-map to write the PNG data.  |
| 2684 | *  |
| 2685 | * png_image is a structure that describes the in-memory format of an image  |
| 2686 | * when it is being read or defines the in-memory format of an image that you  |
| 2687 | * need to write:  |
| 2688 | */  |
| 2689 | #if defined(PNG_SIMPLIFIED_READ_SUPPORTED) || \  |
| 2690 | defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)  |
| 2691 |   |
| 2692 | #define PNG_IMAGE_VERSION 1  |
| 2693 |   |
| 2694 | typedef struct png_control *png_controlp;  |
| 2695 | typedef struct  |
| 2696 | {  |
| 2697 | png_controlp opaque; /* Initialize to NULL, free with png_image_free */  |
| 2698 | png_uint_32 version; /* Set to PNG_IMAGE_VERSION */  |
| 2699 | png_uint_32 width; /* Image width in pixels (columns) */  |
| 2700 | png_uint_32 height; /* Image height in pixels (rows) */  |
| 2701 | png_uint_32 format; /* Image format as defined below */  |
| 2702 | png_uint_32 flags; /* A bit mask containing informational flags */  |
| 2703 | png_uint_32 colormap_entries;  |
| 2704 | /* Number of entries in the color-map */  |
| 2705 |   |
| 2706 | /* In the event of an error or warning the following field will be set to a  |
| 2707 | * non-zero value and the 'message' field will contain a '\0' terminated  |
| 2708 | * string with the libpng error or warning message. If both warnings and  |
| 2709 | * an error were encountered, only the error is recorded. If there  |
| 2710 | * are multiple warnings, only the first one is recorded.  |
| 2711 | *  |
| 2712 | * The upper 30 bits of this value are reserved, the low two bits contain  |
| 2713 | * a value as follows:  |
| 2714 | */  |
| 2715 | # define PNG_IMAGE_WARNING 1  |
| 2716 | # define PNG_IMAGE_ERROR 2  |
| 2717 | /*  |
| 2718 | * The result is a two-bit code such that a value more than 1 indicates  |
| 2719 | * a failure in the API just called:  |
| 2720 | *  |
| 2721 | * 0 - no warning or error  |
| 2722 | * 1 - warning  |
| 2723 | * 2 - error  |
| 2724 | * 3 - error preceded by warning  |
| 2725 | */  |
| 2726 | # define PNG_IMAGE_FAILED(png_cntrl) ((((png_cntrl).warning_or_error)&0x03)>1)  |
| 2727 |   |
| 2728 | png_uint_32 warning_or_error;  |
| 2729 |   |
| 2730 | char message[64];  |
| 2731 | } png_image, *png_imagep;  |
| 2732 |   |
| 2733 | /* The samples of the image have one to four channels whose components have  |
| 2734 | * original values in the range 0 to 1.0:  |
| 2735 | *  |
| 2736 | * 1: A single gray or luminance channel (G).  |
| 2737 | * 2: A gray/luminance channel and an alpha channel (GA).  |
| 2738 | * 3: Three red, green, blue color channels (RGB).  |
| 2739 | * 4: Three color channels and an alpha channel (RGBA).  |
| 2740 | *  |
| 2741 | * The components are encoded in one of two ways:  |
| 2742 | *  |
| 2743 | * a) As a small integer, value 0..255, contained in a single byte. For the  |
| 2744 | * alpha channel the original value is simply value/255. For the color or  |
| 2745 | * luminance channels the value is encoded according to the sRGB specification  |
| 2746 | * and matches the 8-bit format expected by typical display devices.  |
| 2747 | *  |
| 2748 | * The color/gray channels are not scaled (pre-multiplied) by the alpha  |
| 2749 | * channel and are suitable for passing to color management software.  |
| 2750 | *  |
| 2751 | * b) As a value in the range 0..65535, contained in a 2-byte integer. All  |
| 2752 | * channels can be converted to the original value by dividing by 65535; all  |
| 2753 | * channels are linear. Color channels use the RGB encoding (RGB end-points) of  |
| 2754 | * the sRGB specification. This encoding is identified by the  |
| 2755 | * PNG_FORMAT_FLAG_LINEAR flag below.  |
| 2756 | *  |
| 2757 | * When the simplified API needs to convert between sRGB and linear colorspaces,  |
| 2758 | * the actual sRGB transfer curve defined in the sRGB specification (see the  |
| 2759 | * article at <https://en.wikipedia.org/wiki/SRGB>) is used, not the gamma=1/2.2  |
| 2760 | * approximation used elsewhere in libpng.  |
| 2761 | *  |
| 2762 | * When an alpha channel is present it is expected to denote pixel coverage  |
| 2763 | * of the color or luminance channels and is returned as an associated alpha  |
| 2764 | * channel: the color/gray channels are scaled (pre-multiplied) by the alpha  |
| 2765 | * value.  |
| 2766 | *  |
| 2767 | * The samples are either contained directly in the image data, between 1 and 8  |
| 2768 | * bytes per pixel according to the encoding, or are held in a color-map indexed  |
| 2769 | * by bytes in the image data. In the case of a color-map the color-map entries  |
| 2770 | * are individual samples, encoded as above, and the image data has one byte per  |
| 2771 | * pixel to select the relevant sample from the color-map.  |
| 2772 | */  |
| 2773 |   |
| 2774 | /* PNG_FORMAT_*  |
| 2775 | *  |
| 2776 | * #defines to be used in png_image::format. Each #define identifies a  |
| 2777 | * particular layout of sample data and, if present, alpha values. There are  |
| 2778 | * separate defines for each of the two component encodings.  |
| 2779 | *  |
| 2780 | * A format is built up using single bit flag values. All combinations are  |
| 2781 | * valid. Formats can be built up from the flag values or you can use one of  |
| 2782 | * the predefined values below. When testing formats always use the FORMAT_FLAG  |
| 2783 | * macros to test for individual features - future versions of the library may  |
| 2784 | * add new flags.  |
| 2785 | *  |
| 2786 | * When reading or writing color-mapped images the format should be set to the  |
| 2787 | * format of the entries in the color-map then png_image_{read,write}_colormap  |
| 2788 | * called to read or write the color-map and set the format correctly for the  |
| 2789 | * image data. Do not set the PNG_FORMAT_FLAG_COLORMAP bit directly!  |
| 2790 | *  |
| 2791 | * NOTE: libpng can be built with particular features disabled. If you see  |
| 2792 | * compiler errors because the definition of one of the following flags has been  |
| 2793 | * compiled out it is because libpng does not have the required support. It is  |
| 2794 | * possible, however, for the libpng configuration to enable the format on just  |
| 2795 | * read or just write; in that case you may see an error at run time. You can  |
| 2796 | * guard against this by checking for the definition of the appropriate  |
| 2797 | * "_SUPPORTED" macro, one of:  |
| 2798 | *  |
| 2799 | * PNG_SIMPLIFIED_{READ,WRITE}_{BGR,AFIRST}_SUPPORTED  |
| 2800 | */  |
| 2801 | #define PNG_FORMAT_FLAG_ALPHA 0x01U /* format with an alpha channel */  |
| 2802 | #define PNG_FORMAT_FLAG_COLOR 0x02U /* color format: otherwise grayscale */  |
| 2803 | #define PNG_FORMAT_FLAG_LINEAR 0x04U /* 2-byte channels else 1-byte */  |
| 2804 | #define PNG_FORMAT_FLAG_COLORMAP 0x08U /* image data is color-mapped */  |
| 2805 |   |
| 2806 | #ifdef PNG_FORMAT_BGR_SUPPORTED  |
| 2807 | # define PNG_FORMAT_FLAG_BGR 0x10U /* BGR colors, else order is RGB */  |
| 2808 | #endif  |
| 2809 |   |
| 2810 | #ifdef PNG_FORMAT_AFIRST_SUPPORTED  |
| 2811 | # define PNG_FORMAT_FLAG_AFIRST 0x20U /* alpha channel comes first */  |
| 2812 | #endif  |
| 2813 |   |
| 2814 | #define PNG_FORMAT_FLAG_ASSOCIATED_ALPHA 0x40U /* alpha channel is associated */  |
| 2815 |   |
| 2816 | /* Commonly used formats have predefined macros.  |
| 2817 | *  |
| 2818 | * First the single byte (sRGB) formats:  |
| 2819 | */  |
| 2820 | #define PNG_FORMAT_GRAY 0  |
| 2821 | #define PNG_FORMAT_GA PNG_FORMAT_FLAG_ALPHA  |
| 2822 | #define PNG_FORMAT_AG (PNG_FORMAT_GA|PNG_FORMAT_FLAG_AFIRST)  |
| 2823 | #define PNG_FORMAT_RGB PNG_FORMAT_FLAG_COLOR  |
| 2824 | #define PNG_FORMAT_BGR (PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_BGR)  |
| 2825 | #define PNG_FORMAT_RGBA (PNG_FORMAT_RGB|PNG_FORMAT_FLAG_ALPHA)  |
| 2826 | #define PNG_FORMAT_ARGB (PNG_FORMAT_RGBA|PNG_FORMAT_FLAG_AFIRST)  |
| 2827 | #define PNG_FORMAT_BGRA (PNG_FORMAT_BGR|PNG_FORMAT_FLAG_ALPHA)  |
| 2828 | #define PNG_FORMAT_ABGR (PNG_FORMAT_BGRA|PNG_FORMAT_FLAG_AFIRST)  |
| 2829 |   |
| 2830 | /* Then the linear 2-byte formats. When naming these "Y" is used to  |
| 2831 | * indicate a luminance (gray) channel.  |
| 2832 | */  |
| 2833 | #define PNG_FORMAT_LINEAR_Y PNG_FORMAT_FLAG_LINEAR  |
| 2834 | #define PNG_FORMAT_LINEAR_Y_ALPHA (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_ALPHA)  |
| 2835 | #define PNG_FORMAT_LINEAR_RGB (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR)  |
| 2836 | #define PNG_FORMAT_LINEAR_RGB_ALPHA \  |
| 2837 | (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_ALPHA)  |
| 2838 |   |
| 2839 | /* With color-mapped formats the image data is one byte for each pixel, the byte  |
| 2840 | * is an index into the color-map which is formatted as above. To obtain a  |
| 2841 | * color-mapped format it is sufficient just to add the PNG_FOMAT_FLAG_COLORMAP  |
| 2842 | * to one of the above definitions, or you can use one of the definitions below.  |
| 2843 | */  |
| 2844 | #define PNG_FORMAT_RGB_COLORMAP (PNG_FORMAT_RGB|PNG_FORMAT_FLAG_COLORMAP)  |
| 2845 | #define PNG_FORMAT_BGR_COLORMAP (PNG_FORMAT_BGR|PNG_FORMAT_FLAG_COLORMAP)  |
| 2846 | #define PNG_FORMAT_RGBA_COLORMAP (PNG_FORMAT_RGBA|PNG_FORMAT_FLAG_COLORMAP)  |
| 2847 | #define PNG_FORMAT_ARGB_COLORMAP (PNG_FORMAT_ARGB|PNG_FORMAT_FLAG_COLORMAP)  |
| 2848 | #define PNG_FORMAT_BGRA_COLORMAP (PNG_FORMAT_BGRA|PNG_FORMAT_FLAG_COLORMAP)  |
| 2849 | #define PNG_FORMAT_ABGR_COLORMAP (PNG_FORMAT_ABGR|PNG_FORMAT_FLAG_COLORMAP)  |
| 2850 |   |
| 2851 | /* PNG_IMAGE macros  |
| 2852 | *  |
| 2853 | * These are convenience macros to derive information from a png_image  |
| 2854 | * structure. The PNG_IMAGE_SAMPLE_ macros return values appropriate to the  |
| 2855 | * actual image sample values - either the entries in the color-map or the  |
| 2856 | * pixels in the image. The PNG_IMAGE_PIXEL_ macros return corresponding values  |
| 2857 | * for the pixels and will always return 1 for color-mapped formats. The  |
| 2858 | * remaining macros return information about the rows in the image and the  |
| 2859 | * complete image.  |
| 2860 | *  |
| 2861 | * NOTE: All the macros that take a png_image::format parameter are compile time  |
| 2862 | * constants if the format parameter is, itself, a constant. Therefore these  |
| 2863 | * macros can be used in array declarations and case labels where required.  |
| 2864 | * Similarly the macros are also pre-processor constants (sizeof is not used) so  |
| 2865 | * they can be used in #if tests.  |
| 2866 | *  |
| 2867 | * First the information about the samples.  |
| 2868 | */  |
| 2869 | #define PNG_IMAGE_SAMPLE_CHANNELS(fmt)\  |
| 2870 | (((fmt)&(PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_ALPHA))+1)  |
| 2871 | /* Return the total number of channels in a given format: 1..4 */  |
| 2872 |   |
| 2873 | #define PNG_IMAGE_SAMPLE_COMPONENT_SIZE(fmt)\  |
| 2874 | ((((fmt) & PNG_FORMAT_FLAG_LINEAR) >> 2)+1)  |
| 2875 | /* Return the size in bytes of a single component of a pixel or color-map  |
| 2876 | * entry (as appropriate) in the image: 1 or 2.  |
| 2877 | */  |
| 2878 |   |
| 2879 | #define PNG_IMAGE_SAMPLE_SIZE(fmt)\  |
| 2880 | (PNG_IMAGE_SAMPLE_CHANNELS(fmt) * PNG_IMAGE_SAMPLE_COMPONENT_SIZE(fmt))  |
| 2881 | /* This is the size of the sample data for one sample. If the image is  |
| 2882 | * color-mapped it is the size of one color-map entry (and image pixels are  |
| 2883 | * one byte in size), otherwise it is the size of one image pixel.  |
| 2884 | */  |
| 2885 |   |
| 2886 | #define PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(fmt)\  |
| 2887 | (PNG_IMAGE_SAMPLE_CHANNELS(fmt) * 256)  |
| 2888 | /* The maximum size of the color-map required by the format expressed in a  |
| 2889 | * count of components. This can be used to compile-time allocate a  |
| 2890 | * color-map:  |
| 2891 | *  |
| 2892 | * png_uint_16 colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(linear_fmt)];  |
| 2893 | *  |
| 2894 | * png_byte colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(sRGB_fmt)];  |
| 2895 | *  |
| 2896 | * Alternatively use the PNG_IMAGE_COLORMAP_SIZE macro below to use the  |
| 2897 | * information from one of the png_image_begin_read_ APIs and dynamically  |
| 2898 | * allocate the required memory.  |
| 2899 | */  |
| 2900 |   |
| 2901 | /* Corresponding information about the pixels */  |
| 2902 | #define PNG_IMAGE_PIXEL_(test,fmt)\  |
| 2903 | (((fmt)&PNG_FORMAT_FLAG_COLORMAP)?1:test(fmt))  |
| 2904 |   |
| 2905 | #define PNG_IMAGE_PIXEL_CHANNELS(fmt)\  |
| 2906 | PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_CHANNELS,fmt)  |
| 2907 | /* The number of separate channels (components) in a pixel; 1 for a  |
| 2908 | * color-mapped image.  |
| 2909 | */  |
| 2910 |   |
| 2911 | #define PNG_IMAGE_PIXEL_COMPONENT_SIZE(fmt)\  |
| 2912 | PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_COMPONENT_SIZE,fmt)  |
| 2913 | /* The size, in bytes, of each component in a pixel; 1 for a color-mapped  |
| 2914 | * image.  |
| 2915 | */  |
| 2916 |   |
| 2917 | #define PNG_IMAGE_PIXEL_SIZE(fmt) PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_SIZE,fmt)  |
| 2918 | /* The size, in bytes, of a complete pixel; 1 for a color-mapped image. */  |
| 2919 |   |
| 2920 | /* Information about the whole row, or whole image */  |
| 2921 | #define PNG_IMAGE_ROW_STRIDE(image)\  |
| 2922 | (PNG_IMAGE_PIXEL_CHANNELS((image).format) * (image).width)  |
| 2923 | /* Return the total number of components in a single row of the image; this  |
| 2924 | * is the minimum 'row stride', the minimum count of components between each  |
| 2925 | * row. For a color-mapped image this is the minimum number of bytes in a  |
| 2926 | * row.  |
| 2927 | *  |
| 2928 | * WARNING: this macro overflows for some images with more than one component  |
| 2929 | * and very large image widths. libpng will refuse to process an image where  |
| 2930 | * this macro would overflow.  |
| 2931 | */  |
| 2932 |   |
| 2933 | #define PNG_IMAGE_BUFFER_SIZE(image, row_stride)\  |
| 2934 | (PNG_IMAGE_PIXEL_COMPONENT_SIZE((image).format)*(image).height*(row_stride))  |
| 2935 | /* Return the size, in bytes, of an image buffer given a png_image and a row  |
| 2936 | * stride - the number of components to leave space for in each row.  |
| 2937 | *  |
| 2938 | * WARNING: this macro overflows a 32-bit integer for some large PNG images,  |
| 2939 | * libpng will refuse to process an image where such an overflow would occur.  |
| 2940 | */  |
| 2941 |   |
| 2942 | #define PNG_IMAGE_SIZE(image)\  |
| 2943 | PNG_IMAGE_BUFFER_SIZE(image, PNG_IMAGE_ROW_STRIDE(image))  |
| 2944 | /* Return the size, in bytes, of the image in memory given just a png_image;  |
| 2945 | * the row stride is the minimum stride required for the image.  |
| 2946 | */  |
| 2947 |   |
| 2948 | #define PNG_IMAGE_COLORMAP_SIZE(image)\  |
| 2949 | (PNG_IMAGE_SAMPLE_SIZE((image).format) * (image).colormap_entries)  |
| 2950 | /* Return the size, in bytes, of the color-map of this image. If the image  |
| 2951 | * format is not a color-map format this will return a size sufficient for  |
| 2952 | * 256 entries in the given format; check PNG_FORMAT_FLAG_COLORMAP if  |
| 2953 | * you don't want to allocate a color-map in this case.  |
| 2954 | */  |
| 2955 |   |
| 2956 | /* PNG_IMAGE_FLAG_*  |
| 2957 | *  |
| 2958 | * Flags containing additional information about the image are held in the  |
| 2959 | * 'flags' field of png_image.  |
| 2960 | */  |
| 2961 | #define PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB 0x01  |
| 2962 | /* This indicates that the RGB values of the in-memory bitmap do not  |
| 2963 | * correspond to the red, green and blue end-points defined by sRGB.  |
| 2964 | */  |
| 2965 |   |
| 2966 | #define PNG_IMAGE_FLAG_FAST 0x02  |
| 2967 | /* On write emphasise speed over compression; the resultant PNG file will be  |
| 2968 | * larger but will be produced significantly faster, particular for large  |
| 2969 | * images. Do not use this option for images which will be distributed, only  |
| 2970 | * used it when producing intermediate files that will be read back in  |
| 2971 | * repeatedly. For a typical 24-bit image the option will double the read  |
| 2972 | * speed at the cost of increasing the image size by 25%, however for many  |
| 2973 | * more compressible images the PNG file can be 10 times larger with only a  |
| 2974 | * slight speed gain.  |
| 2975 | */  |
| 2976 |   |
| 2977 | #define PNG_IMAGE_FLAG_16BIT_sRGB 0x04  |
| 2978 | /* On read if the image is a 16-bit per component image and there is no gAMA  |
| 2979 | * or sRGB chunk assume that the components are sRGB encoded. Notice that  |
| 2980 | * images output by the simplified API always have gamma information; setting  |
| 2981 | * this flag only affects the interpretation of 16-bit images from an  |
| 2982 | * external source. It is recommended that the application expose this flag  |
| 2983 | * to the user; the user can normally easily recognize the difference between  |
| 2984 | * linear and sRGB encoding. This flag has no effect on write - the data  |
| 2985 | * passed to the write APIs must have the correct encoding (as defined  |
| 2986 | * above.)  |
| 2987 | *  |
| 2988 | * If the flag is not set (the default) input 16-bit per component data is  |
| 2989 | * assumed to be linear.  |
| 2990 | *  |
| 2991 | * NOTE: the flag can only be set after the png_image_begin_read_ call,  |
| 2992 | * because that call initializes the 'flags' field.  |
| 2993 | */  |
| 2994 |   |
| 2995 | #ifdef PNG_SIMPLIFIED_READ_SUPPORTED  |
| 2996 | /* READ APIs  |
| 2997 | * ---------  |
| 2998 | *  |
| 2999 | * The png_image passed to the read APIs must have been initialized by setting  |
| 3000 | * the png_controlp field 'opaque' to NULL (or, safer, memset the whole thing.)  |
| 3001 | */  |
| 3002 | #ifdef PNG_STDIO_SUPPORTED  |
| 3003 | PNG_EXPORT(234, int, png_image_begin_read_from_file, (png_imagep image,  |
| 3004 | const char *file_name));  |
| 3005 | /* The named file is opened for read and the image header is filled in  |
| 3006 | * from the PNG header in the file.  |
| 3007 | */  |
| 3008 |   |
| 3009 | PNG_EXPORT(235, int, png_image_begin_read_from_stdio, (png_imagep image,  |
| 3010 | FILE* file));  |
| 3011 | /* The PNG header is read from the stdio FILE object. */  |
| 3012 | #endif /* STDIO */  |
| 3013 |   |
| 3014 | PNG_EXPORT(236, int, png_image_begin_read_from_memory, (png_imagep image,  |
| 3015 | png_const_voidp memory, size_t size));  |
| 3016 | /* The PNG header is read from the given memory buffer. */  |
| 3017 |   |
| 3018 | PNG_EXPORT(237, int, png_image_finish_read, (png_imagep image,  |
| 3019 | png_const_colorp background, void *buffer, png_int_32 row_stride,  |
| 3020 | void *colormap));  |
| 3021 | /* Finish reading the image into the supplied buffer and clean up the  |
| 3022 | * png_image structure.  |
| 3023 | *  |
| 3024 | * row_stride is the step, in byte or 2-byte units as appropriate,  |
| 3025 | * between adjacent rows. A positive stride indicates that the top-most row  |
| 3026 | * is first in the buffer - the normal top-down arrangement. A negative  |
| 3027 | * stride indicates that the bottom-most row is first in the buffer.  |
| 3028 | *  |
| 3029 | * background need only be supplied if an alpha channel must be removed from  |
| 3030 | * a png_byte format and the removal is to be done by compositing on a solid  |
| 3031 | * color; otherwise it may be NULL and any composition will be done directly  |
| 3032 | * onto the buffer. The value is an sRGB color to use for the background,  |
| 3033 | * for grayscale output the green channel is used.  |
| 3034 | *  |
| 3035 | * background must be supplied when an alpha channel must be removed from a  |
| 3036 | * single byte color-mapped output format, in other words if:  |
| 3037 | *  |
| 3038 | * 1) The original format from png_image_begin_read_from_* had  |
| 3039 | * PNG_FORMAT_FLAG_ALPHA set.  |
| 3040 | * 2) The format set by the application does not.  |
| 3041 | * 3) The format set by the application has PNG_FORMAT_FLAG_COLORMAP set and  |
| 3042 | * PNG_FORMAT_FLAG_LINEAR *not* set.  |
| 3043 | *  |
| 3044 | * For linear output removing the alpha channel is always done by compositing  |
| 3045 | * on black and background is ignored.  |
| 3046 | *  |
| 3047 | * colormap must be supplied when PNG_FORMAT_FLAG_COLORMAP is set. It must  |
| 3048 | * be at least the size (in bytes) returned by PNG_IMAGE_COLORMAP_SIZE.  |
| 3049 | * image->colormap_entries will be updated to the actual number of entries  |
| 3050 | * written to the colormap; this may be less than the original value.  |
| 3051 | */  |
| 3052 |   |
| 3053 | PNG_EXPORT(238, void, png_image_free, (png_imagep image));  |
| 3054 | /* Free any data allocated by libpng in image->opaque, setting the pointer to  |
| 3055 | * NULL. May be called at any time after the structure is initialized.  |
| 3056 | */  |
| 3057 | #endif /* SIMPLIFIED_READ */  |
| 3058 |   |
| 3059 | #ifdef PNG_SIMPLIFIED_WRITE_SUPPORTED  |
| 3060 | /* WRITE APIS  |
| 3061 | * ----------  |
| 3062 | * For write you must initialize a png_image structure to describe the image to  |
| 3063 | * be written. To do this use memset to set the whole structure to 0 then  |
| 3064 | * initialize fields describing your image.  |
| 3065 | *  |
| 3066 | * version: must be set to PNG_IMAGE_VERSION  |
| 3067 | * opaque: must be initialized to NULL  |
| 3068 | * width: image width in pixels  |
| 3069 | * height: image height in rows  |
| 3070 | * format: the format of the data (image and color-map) you wish to write  |
| 3071 | * flags: set to 0 unless one of the defined flags applies; set  |
| 3072 | * PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB for color format images where the RGB  |
| 3073 | * values do not correspond to the colors in sRGB.  |
| 3074 | * colormap_entries: set to the number of entries in the color-map (0 to 256)  |
| 3075 | */  |
| 3076 | #ifdef PNG_SIMPLIFIED_WRITE_STDIO_SUPPORTED  |
| 3077 | PNG_EXPORT(239, int, png_image_write_to_file, (png_imagep image,  |
| 3078 | const char *file, int convert_to_8bit, const void *buffer,  |
| 3079 | png_int_32 row_stride, const void *colormap));  |
| 3080 | /* Write the image to the named file. */  |
| 3081 |   |
| 3082 | PNG_EXPORT(240, int, png_image_write_to_stdio, (png_imagep image, FILE *file,  |
| 3083 | int convert_to_8_bit, const void *buffer, png_int_32 row_stride,  |
| 3084 | const void *colormap));  |
| 3085 | /* Write the image to the given (FILE*). */  |
| 3086 | #endif /* SIMPLIFIED_WRITE_STDIO */  |
| 3087 |   |
| 3088 | /* With all write APIs if image is in one of the linear formats with 16-bit  |
| 3089 | * data then setting convert_to_8_bit will cause the output to be an 8-bit PNG  |
| 3090 | * gamma encoded according to the sRGB specification, otherwise a 16-bit linear  |
| 3091 | * encoded PNG file is written.  |
| 3092 | *  |
| 3093 | * With color-mapped data formats the colormap parameter point to a color-map  |
| 3094 | * with at least image->colormap_entries encoded in the specified format. If  |
| 3095 | * the format is linear the written PNG color-map will be converted to sRGB  |
| 3096 | * regardless of the convert_to_8_bit flag.  |
| 3097 | *  |
| 3098 | * With all APIs row_stride is handled as in the read APIs - it is the spacing  |
| 3099 | * from one row to the next in component sized units (1 or 2 bytes) and if  |
| 3100 | * negative indicates a bottom-up row layout in the buffer. If row_stride is  |
| 3101 | * zero, libpng will calculate it for you from the image width and number of  |
| 3102 | * channels.  |
| 3103 | *  |
| 3104 | * Note that the write API does not support interlacing, sub-8-bit pixels or  |
| 3105 | * most ancillary chunks. If you need to write text chunks (e.g. for copyright  |
| 3106 | * notices) you need to use one of the other APIs.  |
| 3107 | */  |
| 3108 |   |
| 3109 | PNG_EXPORT(245, int, png_image_write_to_memory, (png_imagep image, void *memory,  |
| 3110 | png_alloc_size_t * PNG_RESTRICT memory_bytes, int convert_to_8_bit,  |
| 3111 | const void *buffer, png_int_32 row_stride, const void *colormap));  |
| 3112 | /* Write the image to the given memory buffer. The function both writes the  |
| 3113 | * whole PNG data stream to *memory and updates *memory_bytes with the count  |
| 3114 | * of bytes written.  |
| 3115 | *  |
| 3116 | * 'memory' may be NULL. In this case *memory_bytes is not read however on  |
| 3117 | * success the number of bytes which would have been written will still be  |
| 3118 | * stored in *memory_bytes. On failure *memory_bytes will contain 0.  |
| 3119 | *  |
| 3120 | * If 'memory' is not NULL it must point to memory[*memory_bytes] of  |
| 3121 | * writeable memory.  |
| 3122 | *  |
| 3123 | * If the function returns success memory[*memory_bytes] (if 'memory' is not  |
| 3124 | * NULL) contains the written PNG data. *memory_bytes will always be less  |
| 3125 | * than or equal to the original value.  |
| 3126 | *  |
| 3127 | * If the function returns false and *memory_bytes was not changed an error  |
| 3128 | * occurred during write. If *memory_bytes was changed, or is not 0 if  |
| 3129 | * 'memory' was NULL, the write would have succeeded but for the memory  |
| 3130 | * buffer being too small. *memory_bytes contains the required number of  |
| 3131 | * bytes and will be bigger that the original value.  |
| 3132 | */  |
| 3133 |   |
| 3134 | #define png_image_write_get_memory_size(image, size, convert_to_8_bit, buffer,\  |
| 3135 | row_stride, colormap)\  |
| 3136 | png_image_write_to_memory(&(image), 0, &(size), convert_to_8_bit, buffer,\  |
| 3137 | row_stride, colormap)  |
| 3138 | /* Return the amount of memory in 'size' required to compress this image.  |
| 3139 | * The png_image structure 'image' must be filled in as in the above  |
| 3140 | * function and must not be changed before the actual write call, the buffer  |
| 3141 | * and all other parameters must also be identical to that in the final  |
| 3142 | * write call. The 'size' variable need not be initialized.  |
| 3143 | *  |
| 3144 | * NOTE: the macro returns true/false, if false is returned 'size' will be  |
| 3145 | * set to zero and the write failed and probably will fail if tried again.  |
| 3146 | */  |
| 3147 |   |
| 3148 | /* You can pre-allocate the buffer by making sure it is of sufficient size  |
| 3149 | * regardless of the amount of compression achieved. The buffer size will  |
| 3150 | * always be bigger than the original image and it will never be filled. The  |
| 3151 | * following macros are provided to assist in allocating the buffer.  |
| 3152 | */  |
| 3153 | #define PNG_IMAGE_DATA_SIZE(image) (PNG_IMAGE_SIZE(image)+(image).height)  |
| 3154 | /* The number of uncompressed bytes in the PNG byte encoding of the image;  |
| 3155 | * uncompressing the PNG IDAT data will give this number of bytes.  |
| 3156 | *  |
| 3157 | * NOTE: while PNG_IMAGE_SIZE cannot overflow for an image in memory this  |
| 3158 | * macro can because of the extra bytes used in the PNG byte encoding. You  |
| 3159 | * need to avoid this macro if your image size approaches 2^30 in width or  |
| 3160 | * height. The same goes for the remainder of these macros; they all produce  |
| 3161 | * bigger numbers than the actual in-memory image size.  |
| 3162 | */  |
| 3163 | #ifndef PNG_ZLIB_MAX_SIZE  |
| 3164 | # define PNG_ZLIB_MAX_SIZE(b) ((b)+(((b)+7U)>>3)+(((b)+63U)>>6)+11U)  |
| 3165 | /* An upper bound on the number of compressed bytes given 'b' uncompressed  |
| 3166 | * bytes. This is based on deflateBounds() in zlib; different  |
| 3167 | * implementations of zlib compression may conceivably produce more data so  |
| 3168 | * if your zlib implementation is not zlib itself redefine this macro  |
| 3169 | * appropriately.  |
| 3170 | */  |
| 3171 | #endif  |
| 3172 |   |
| 3173 | #define PNG_IMAGE_COMPRESSED_SIZE_MAX(image)\  |
| 3174 | PNG_ZLIB_MAX_SIZE((png_alloc_size_t)PNG_IMAGE_DATA_SIZE(image))  |
| 3175 | /* An upper bound on the size of the data in the PNG IDAT chunks. */  |
| 3176 |   |
| 3177 | #define PNG_IMAGE_PNG_SIZE_MAX_(image, image_size)\  |
| 3178 | ((8U/*sig*/+25U/*IHDR*/+16U/*gAMA*/+44U/*cHRM*/+12U/*IEND*/+\  |
| 3179 | (((image).format&PNG_FORMAT_FLAG_COLORMAP)?/*colormap: PLTE, tRNS*/\  |
| 3180 | 12U+3U*(image).colormap_entries/*PLTE data*/+\  |
| 3181 | (((image).format&PNG_FORMAT_FLAG_ALPHA)?\  |
| 3182 | 12U/*tRNS*/+(image).colormap_entries:0U):0U)+\  |
| 3183 | 12U)+(12U*((image_size)/PNG_ZBUF_SIZE))/*IDAT*/+(image_size))  |
| 3184 | /* A helper for the following macro; if your compiler cannot handle the  |
| 3185 | * following macro use this one with the result of  |
| 3186 | * PNG_IMAGE_COMPRESSED_SIZE_MAX(image) as the second argument (most  |
| 3187 | * compilers should handle this just fine.)  |
| 3188 | */  |
| 3189 |   |
| 3190 | #define PNG_IMAGE_PNG_SIZE_MAX(image)\  |
| 3191 | PNG_IMAGE_PNG_SIZE_MAX_(image, PNG_IMAGE_COMPRESSED_SIZE_MAX(image))  |
| 3192 | /* An upper bound on the total length of the PNG data stream for 'image'.  |
| 3193 | * The result is of type png_alloc_size_t, on 32-bit systems this may  |
| 3194 | * overflow even though PNG_IMAGE_DATA_SIZE does not overflow; the write will  |
| 3195 | * run out of buffer space but return a corrected size which should work.  |
| 3196 | */  |
| 3197 | #endif /* SIMPLIFIED_WRITE */  |
| 3198 | /*******************************************************************************  |
| 3199 | * END OF SIMPLIFIED API  |
| 3200 | ******************************************************************************/  |
| 3201 | #endif /* SIMPLIFIED_{READ|WRITE} */  |
| 3202 |   |
| 3203 | /*******************************************************************************  |
| 3204 | * Section 6: IMPLEMENTATION OPTIONS  |
| 3205 | *******************************************************************************  |
| 3206 | *  |
| 3207 | * Support for arbitrary implementation-specific optimizations. The API allows  |
| 3208 | * particular options to be turned on or off. 'Option' is the number of the  |
| 3209 | * option and 'onoff' is 0 (off) or non-0 (on). The value returned is given  |
| 3210 | * by the PNG_OPTION_ defines below.  |
| 3211 | *  |
| 3212 | * HARDWARE: normally hardware capabilities, such as the Intel SSE instructions,  |
| 3213 | * are detected at run time, however sometimes it may be impossible  |
| 3214 | * to do this in user mode, in which case it is necessary to discover  |
| 3215 | * the capabilities in an OS specific way. Such capabilities are  |
| 3216 | * listed here when libpng has support for them and must be turned  |
| 3217 | * ON by the application if present.  |
| 3218 | *  |
| 3219 | * SOFTWARE: sometimes software optimizations actually result in performance  |
| 3220 | * decrease on some architectures or systems, or with some sets of  |
| 3221 | * PNG images. 'Software' options allow such optimizations to be  |
| 3222 | * selected at run time.  |
| 3223 | */  |
| 3224 | #ifdef PNG_SET_OPTION_SUPPORTED  |
| 3225 | #ifdef PNG_ARM_NEON_API_SUPPORTED  |
| 3226 | # define PNG_ARM_NEON 0 /* HARDWARE: ARM Neon SIMD instructions supported */  |
| 3227 | #endif  |
| 3228 | #define PNG_MAXIMUM_INFLATE_WINDOW 2 /* SOFTWARE: force maximum window */  |
| 3229 | #define PNG_SKIP_sRGB_CHECK_PROFILE 4 /* SOFTWARE: Check ICC profile for sRGB */  |
| 3230 | #ifdef PNG_MIPS_MSA_API_SUPPORTED  |
| 3231 | # define PNG_MIPS_MSA 6 /* HARDWARE: MIPS Msa SIMD instructions supported */  |
| 3232 | #endif  |
| 3233 | #define PNG_IGNORE_ADLER32 8  |
| 3234 | #ifdef PNG_POWERPC_VSX_API_SUPPORTED  |
| 3235 | # define PNG_POWERPC_VSX 10 /* HARDWARE: PowerPC VSX SIMD instructions supported */  |
| 3236 | #endif  |
| 3237 | #define PNG_OPTION_NEXT 12 /* Next option - numbers must be even */  |
| 3238 |   |
| 3239 | /* Return values: NOTE: there are four values and 'off' is *not* zero */  |
| 3240 | #define PNG_OPTION_UNSET 0 /* Unset - defaults to off */  |
| 3241 | #define PNG_OPTION_INVALID 1 /* Option number out of range */  |
| 3242 | #define PNG_OPTION_OFF 2  |
| 3243 | #define PNG_OPTION_ON 3  |
| 3244 |   |
| 3245 | PNG_EXPORT(244, int, png_set_option, (png_structrp png_ptr, int option,  |
| 3246 | int onoff));  |
| 3247 | #endif /* SET_OPTION */  |
| 3248 |   |
| 3249 | /*******************************************************************************  |
| 3250 | * END OF HARDWARE AND SOFTWARE OPTIONS  |
| 3251 | ******************************************************************************/  |
| 3252 | #ifdef PNG_APNG_SUPPORTED  |
| 3253 | PNG_EXPORT(250, png_uint_32, png_get_acTL, (png_structp png_ptr,  |
| 3254 | png_infop info_ptr, png_uint_32 *num_frames, png_uint_32 *num_plays));  |
| 3255 |   |
| 3256 | PNG_EXPORT(251, png_uint_32, png_set_acTL, (png_structp png_ptr,  |
| 3257 | png_infop info_ptr, png_uint_32 num_frames, png_uint_32 num_plays));  |
| 3258 |   |
| 3259 | PNG_EXPORT(252, png_uint_32, png_get_num_frames, (png_structp png_ptr,  |
| 3260 | png_infop info_ptr));  |
| 3261 |   |
| 3262 | PNG_EXPORT(253, png_uint_32, png_get_num_plays, (png_structp png_ptr,  |
| 3263 | png_infop info_ptr));  |
| 3264 |   |
| 3265 | PNG_EXPORT(254, png_uint_32, png_get_next_frame_fcTL,  |
| 3266 | (png_structp png_ptr, png_infop info_ptr, png_uint_32 *width,  |
| 3267 | png_uint_32 *height, png_uint_32 *x_offset, png_uint_32 *y_offset,  |
| 3268 | png_uint_16 *delay_num, png_uint_16 *delay_den, png_byte *dispose_op,  |
| 3269 | png_byte *blend_op));  |
| 3270 |   |
| 3271 | PNG_EXPORT(255, png_uint_32, png_set_next_frame_fcTL,  |
| 3272 | (png_structp png_ptr, png_infop info_ptr, png_uint_32 width,  |
| 3273 | png_uint_32 height, png_uint_32 x_offset, png_uint_32 y_offset,  |
| 3274 | png_uint_16 delay_num, png_uint_16 delay_den, png_byte dispose_op,  |
| 3275 | png_byte blend_op));  |
| 3276 |   |
| 3277 | PNG_EXPORT(256, png_uint_32, png_get_next_frame_width,  |
| 3278 | (png_structp png_ptr, png_infop info_ptr));  |
| 3279 | PNG_EXPORT(257, png_uint_32, png_get_next_frame_height,  |
| 3280 | (png_structp png_ptr, png_infop info_ptr));  |
| 3281 | PNG_EXPORT(258, png_uint_32, png_get_next_frame_x_offset,  |
| 3282 | (png_structp png_ptr, png_infop info_ptr));  |
| 3283 | PNG_EXPORT(259, png_uint_32, png_get_next_frame_y_offset,  |
| 3284 | (png_structp png_ptr, png_infop info_ptr));  |
| 3285 | PNG_EXPORT(260, png_uint_16, png_get_next_frame_delay_num,  |
| 3286 | (png_structp png_ptr, png_infop info_ptr));  |
| 3287 | PNG_EXPORT(261, png_uint_16, png_get_next_frame_delay_den,  |
| 3288 | (png_structp png_ptr, png_infop info_ptr));  |
| 3289 | PNG_EXPORT(262, png_byte, png_get_next_frame_dispose_op,  |
| 3290 | (png_structp png_ptr, png_infop info_ptr));  |
| 3291 | PNG_EXPORT(263, png_byte, png_get_next_frame_blend_op,  |
| 3292 | (png_structp png_ptr, png_infop info_ptr));  |
| 3293 | PNG_EXPORT(264, png_byte, png_get_first_frame_is_hidden,  |
| 3294 | (png_structp png_ptr, png_infop info_ptr));  |
| 3295 | PNG_EXPORT(265, png_uint_32, png_set_first_frame_is_hidden,  |
| 3296 | (png_structp png_ptr, png_infop info_ptr, png_byte is_hidden));  |
| 3297 |   |
| 3298 | #ifdef PNG_READ_APNG_SUPPORTED  |
| 3299 | PNG_EXPORT(266, void, png_read_frame_head, (png_structp png_ptr,  |
| 3300 | png_infop info_ptr));  |
| 3301 | #ifdef PNG_PROGRESSIVE_READ_SUPPORTED  |
| 3302 | PNG_EXPORT(267, void, png_set_progressive_frame_fn, (png_structp png_ptr,  |
| 3303 | png_progressive_frame_ptr frame_info_fn,  |
| 3304 | png_progressive_frame_ptr frame_end_fn));  |
| 3305 | #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */  |
| 3306 | #endif /* PNG_READ_APNG_SUPPORTED */  |
| 3307 |   |
| 3308 | #ifdef PNG_WRITE_APNG_SUPPORTED  |
| 3309 | PNG_EXPORT(268, void, png_write_frame_head, (png_structp png_ptr,  |
| 3310 | png_infop info_ptr, png_bytepp row_pointers,  |
| 3311 | png_uint_32 width, png_uint_32 height,  |
| 3312 | png_uint_32 x_offset, png_uint_32 y_offset,  |
| 3313 | png_uint_16 delay_num, png_uint_16 delay_den, png_byte dispose_op,  |
| 3314 | png_byte blend_op));  |
| 3315 |   |
| 3316 | PNG_EXPORT(269, void, png_write_frame_tail, (png_structp png_ptr,  |
| 3317 | png_infop info_ptr));  |
| 3318 | #endif /* PNG_WRITE_APNG_SUPPORTED */  |
| 3319 | #endif /* PNG_APNG_SUPPORTED */  |
| 3320 |   |
| 3321 | /* Maintainer: Put new public prototypes here ^, in libpng.3, in project  |
| 3322 | * defs, and in scripts/symbols.def.  |
| 3323 | */  |
| 3324 |   |
| 3325 | /* The last ordinal number (this is the *last* one already used; the next  |
| 3326 | * one to use is one more than this.)  |
| 3327 | */  |
| 3328 | #ifdef PNG_EXPORT_LAST_ORDINAL  |
| 3329 | #ifdef PNG_APNG_SUPPORTED  |
| 3330 | PNG_EXPORT_LAST_ORDINAL(269);  |
| 3331 | #else  |
| 3332 | PNG_EXPORT_LAST_ORDINAL(249);  |
| 3333 | #endif /* PNG_APNG_SUPPORTED */  |
| 3334 | #endif  |
| 3335 |   |
| 3336 | #ifdef __cplusplus  |
| 3337 | }  |
| 3338 | #endif  |
| 3339 |   |
| 3340 | #endif /* PNG_VERSION_INFO_ONLY */  |
| 3341 | /* Do not put anything past this line */  |
| 3342 | #endif /* PNG_H */  |
| 3343 | |