1 2 /* png.h - header file for PNG reference library 3 * 4 * libpng version 1.5.13 - September 27, 2012 5 * Copyright (c) 1998-2012 Glenn Randers-Pehrson 6 * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) 7 * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) 8 * 9 * This code is released under the libpng license (See LICENSE, below) 10 * 11 * Authors and maintainers: 12 * libpng versions 0.71, May 1995, through 0.88, January 1996: Guy Schalnat 13 * libpng versions 0.89c, June 1996, through 0.96, May 1997: Andreas Dilger 14 * libpng versions 0.97, January 1998, through 1.5.13 - September 27, 2012: Glenn 15 * See also "Contributing Authors", below. 16 * 17 * Note about libpng version numbers: 18 * 19 * Due to various miscommunications, unforeseen code incompatibilities 20 * and occasional factors outside the authors' control, version numbering 21 * on the library has not always been consistent and straightforward. 22 * The following table summarizes matters since version 0.89c, which was 23 * the first widely used release: 24 * 25 * source png.h png.h shared-lib 26 * version string int version 27 * ------- ------ ----- ---------- 28 * 0.89c "1.0 beta 3" 0.89 89 1.0.89 29 * 0.90 "1.0 beta 4" 0.90 90 0.90 [should have been 2.0.90] 30 * 0.95 "1.0 beta 5" 0.95 95 0.95 [should have been 2.0.95] 31 * 0.96 "1.0 beta 6" 0.96 96 0.96 [should have been 2.0.96] 32 * 0.97b "1.00.97 beta 7" 1.00.97 97 1.0.1 [should have been 2.0.97] 33 * 0.97c 0.97 97 2.0.97 34 * 0.98 0.98 98 2.0.98 35 * 0.99 0.99 98 2.0.99 36 * 0.99a-m 0.99 99 2.0.99 37 * 1.00 1.00 100 2.1.0 [100 should be 10000] 38 * 1.0.0 (from here on, the 100 2.1.0 [100 should be 10000] 39 * 1.0.1 png.h string is 10001 2.1.0 40 * 1.0.1a-e identical to the 10002 from here on, the shared library 41 * 1.0.2 source version) 10002 is 2.V where V is the source code 42 * 1.0.2a-b 10003 version, except as noted. 43 * 1.0.3 10003 44 * 1.0.3a-d 10004 45 * 1.0.4 10004 46 * 1.0.4a-f 10005 47 * 1.0.5 (+ 2 patches) 10005 48 * 1.0.5a-d 10006 49 * 1.0.5e-r 10100 (not source compatible) 50 * 1.0.5s-v 10006 (not binary compatible) 51 * 1.0.6 (+ 3 patches) 10006 (still binary incompatible) 52 * 1.0.6d-f 10007 (still binary incompatible) 53 * 1.0.6g 10007 54 * 1.0.6h 10007 10.6h (testing xy.z so-numbering) 55 * 1.0.6i 10007 10.6i 56 * 1.0.6j 10007 2.1.0.6j (incompatible with 1.0.0) 57 * 1.0.7beta11-14 DLLNUM 10007 2.1.0.7beta11-14 (binary compatible) 58 * 1.0.7beta15-18 1 10007 2.1.0.7beta15-18 (binary compatible) 59 * 1.0.7rc1-2 1 10007 2.1.0.7rc1-2 (binary compatible) 60 * 1.0.7 1 10007 (still compatible) 61 * 1.0.8beta1-4 1 10008 2.1.0.8beta1-4 62 * 1.0.8rc1 1 10008 2.1.0.8rc1 63 * 1.0.8 1 10008 2.1.0.8 64 * 1.0.9beta1-6 1 10009 2.1.0.9beta1-6 65 * 1.0.9rc1 1 10009 2.1.0.9rc1 66 * 1.0.9beta7-10 1 10009 2.1.0.9beta7-10 67 * 1.0.9rc2 1 10009 2.1.0.9rc2 68 * 1.0.9 1 10009 2.1.0.9 69 * 1.0.10beta1 1 10010 2.1.0.10beta1 70 * 1.0.10rc1 1 10010 2.1.0.10rc1 71 * 1.0.10 1 10010 2.1.0.10 72 * 1.0.11beta1-3 1 10011 2.1.0.11beta1-3 73 * 1.0.11rc1 1 10011 2.1.0.11rc1 74 * 1.0.11 1 10011 2.1.0.11 75 * 1.0.12beta1-2 2 10012 2.1.0.12beta1-2 76 * 1.0.12rc1 2 10012 2.1.0.12rc1 77 * 1.0.12 2 10012 2.1.0.12 78 * 1.1.0a-f - 10100 2.1.1.0a-f (branch abandoned) 79 * 1.2.0beta1-2 2 10200 2.1.2.0beta1-2 80 * 1.2.0beta3-5 3 10200 3.1.2.0beta3-5 81 * 1.2.0rc1 3 10200 3.1.2.0rc1 82 * 1.2.0 3 10200 3.1.2.0 83 * 1.2.1beta1-4 3 10201 3.1.2.1beta1-4 84 * 1.2.1rc1-2 3 10201 3.1.2.1rc1-2 85 * 1.2.1 3 10201 3.1.2.1 86 * 1.2.2beta1-6 12 10202 12.so.0.1.2.2beta1-6 87 * 1.0.13beta1 10 10013 10.so.0.1.0.13beta1 88 * 1.0.13rc1 10 10013 10.so.0.1.0.13rc1 89 * 1.2.2rc1 12 10202 12.so.0.1.2.2rc1 90 * 1.0.13 10 10013 10.so.0.1.0.13 91 * 1.2.2 12 10202 12.so.0.1.2.2 92 * 1.2.3rc1-6 12 10203 12.so.0.1.2.3rc1-6 93 * 1.2.3 12 10203 12.so.0.1.2.3 94 * 1.2.4beta1-3 13 10204 12.so.0.1.2.4beta1-3 95 * 1.0.14rc1 13 10014 10.so.0.1.0.14rc1 96 * 1.2.4rc1 13 10204 12.so.0.1.2.4rc1 97 * 1.0.14 10 10014 10.so.0.1.0.14 98 * 1.2.4 13 10204 12.so.0.1.2.4 99 * 1.2.5beta1-2 13 10205 12.so.0.1.2.5beta1-2 100 * 1.0.15rc1-3 10 10015 10.so.0.1.0.15rc1-3 101 * 1.2.5rc1-3 13 10205 12.so.0.1.2.5rc1-3 102 * 1.0.15 10 10015 10.so.0.1.0.15 103 * 1.2.5 13 10205 12.so.0.1.2.5 104 * 1.2.6beta1-4 13 10206 12.so.0.1.2.6beta1-4 105 * 1.0.16 10 10016 10.so.0.1.0.16 106 * 1.2.6 13 10206 12.so.0.1.2.6 107 * 1.2.7beta1-2 13 10207 12.so.0.1.2.7beta1-2 108 * 1.0.17rc1 10 10017 12.so.0.1.0.17rc1 109 * 1.2.7rc1 13 10207 12.so.0.1.2.7rc1 110 * 1.0.17 10 10017 12.so.0.1.0.17 111 * 1.2.7 13 10207 12.so.0.1.2.7 112 * 1.2.8beta1-5 13 10208 12.so.0.1.2.8beta1-5 113 * 1.0.18rc1-5 10 10018 12.so.0.1.0.18rc1-5 114 * 1.2.8rc1-5 13 10208 12.so.0.1.2.8rc1-5 115 * 1.0.18 10 10018 12.so.0.1.0.18 116 * 1.2.8 13 10208 12.so.0.1.2.8 117 * 1.2.9beta1-3 13 10209 12.so.0.1.2.9beta1-3 118 * 1.2.9beta4-11 13 10209 12.so.0.9[.0] 119 * 1.2.9rc1 13 10209 12.so.0.9[.0] 120 * 1.2.9 13 10209 12.so.0.9[.0] 121 * 1.2.10beta1-7 13 10210 12.so.0.10[.0] 122 * 1.2.10rc1-2 13 10210 12.so.0.10[.0] 123 * 1.2.10 13 10210 12.so.0.10[.0] 124 * 1.4.0beta1-5 14 10400 14.so.0.0[.0] 125 * 1.2.11beta1-4 13 10211 12.so.0.11[.0] 126 * 1.4.0beta7-8 14 10400 14.so.0.0[.0] 127 * 1.2.11 13 10211 12.so.0.11[.0] 128 * 1.2.12 13 10212 12.so.0.12[.0] 129 * 1.4.0beta9-14 14 10400 14.so.0.0[.0] 130 * 1.2.13 13 10213 12.so.0.13[.0] 131 * 1.4.0beta15-36 14 10400 14.so.0.0[.0] 132 * 1.4.0beta37-87 14 10400 14.so.14.0[.0] 133 * 1.4.0rc01 14 10400 14.so.14.0[.0] 134 * 1.4.0beta88-109 14 10400 14.so.14.0[.0] 135 * 1.4.0rc02-08 14 10400 14.so.14.0[.0] 136 * 1.4.0 14 10400 14.so.14.0[.0] 137 * 1.4.1beta01-03 14 10401 14.so.14.1[.0] 138 * 1.4.1rc01 14 10401 14.so.14.1[.0] 139 * 1.4.1beta04-12 14 10401 14.so.14.1[.0] 140 * 1.4.1 14 10401 14.so.14.1[.0] 141 * 1.4.2 14 10402 14.so.14.2[.0] 142 * 1.4.3 14 10403 14.so.14.3[.0] 143 * 1.4.4 14 10404 14.so.14.4[.0] 144 * 1.5.0beta01-58 15 10500 15.so.15.0[.0] 145 * 1.5.0rc01-07 15 10500 15.so.15.0[.0] 146 * 1.5.0 15 10500 15.so.15.0[.0] 147 * 1.5.1beta01-11 15 10501 15.so.15.1[.0] 148 * 1.5.1rc01-02 15 10501 15.so.15.1[.0] 149 * 1.5.1 15 10501 15.so.15.1[.0] 150 * 1.5.2beta01-03 15 10502 15.so.15.2[.0] 151 * 1.5.2rc01-03 15 10502 15.so.15.2[.0] 152 * 1.5.2 15 10502 15.so.15.2[.0] 153 * 1.5.3beta01-10 15 10503 15.so.15.3[.0] 154 * 1.5.3rc01-02 15 10503 15.so.15.3[.0] 155 * 1.5.3beta11 15 10503 15.so.15.3[.0] 156 * 1.5.3 [omitted] 157 * 1.5.4beta01-08 15 10504 15.so.15.4[.0] 158 * 1.5.4rc01 15 10504 15.so.15.4[.0] 159 * 1.5.4 15 10504 15.so.15.4[.0] 160 * 1.5.5beta01-08 15 10505 15.so.15.5[.0] 161 * 1.5.5rc01 15 10505 15.so.15.5[.0] 162 * 1.5.5 15 10505 15.so.15.5[.0] 163 * 1.5.6beta01-07 15 10506 15.so.15.6[.0] 164 * 1.5.6rc01-03 15 10506 15.so.15.6[.0] 165 * 1.5.6 15 10506 15.so.15.6[.0] 166 * 1.5.7beta01-05 15 10507 15.so.15.7[.0] 167 * 1.5.7rc01-03 15 10507 15.so.15.7[.0] 168 * 1.5.7 15 10507 15.so.15.7[.0] 169 * 1.5.8beta01 15 10508 15.so.15.8[.0] 170 * 1.5.8rc01 15 10508 15.so.15.8[.0] 171 * 1.5.8 15 10508 15.so.15.8[.0] 172 * 1.5.9beta01-02 15 10509 15.so.15.9[.0] 173 * 1.5.9rc01 15 10509 15.so.15.9[.0] 174 * 1.5.9 15 10509 15.so.15.9[.0] 175 * 1.5.10beta01-05 15 10510 15.so.15.10[.0] 176 * 1.5.10 15 10510 15.so.15.10[.0] 177 * 1.5.11beta01 15 10511 15.so.15.11[.0] 178 * 1.5.11rc01-05 15 10511 15.so.15.11[.0] 179 * 1.5.11 15 10511 15.so.15.11[.0] 180 * 1.5.12 15 10512 15.so.15.12[.0] 181 * 1.5.13beta01-02 15 10513 15.so.15.13[.0] 182 * 1.5.13rc01 15 10513 15.so.15.13[.0] 183 * 1.5.13 15 10513 15.so.15.13[.0] 184 * 185 * Henceforth the source version will match the shared-library major 186 * and minor numbers; the shared-library major version number will be 187 * used for changes in backward compatibility, as it is intended. The 188 * PNG_LIBPNG_VER macro, which is not used within libpng but is available 189 * for applications, is an unsigned integer of the form xyyzz corresponding 190 * to the source version x.y.z (leading zeros in y and z). Beta versions 191 * were given the previous public release number plus a letter, until 192 * version 1.0.6j; from then on they were given the upcoming public 193 * release number plus "betaNN" or "rcNN". 194 * 195 * Binary incompatibility exists only when applications make direct access 196 * to the info_ptr or png_ptr members through png.h, and the compiled 197 * application is loaded with a different version of the library. 198 * 199 * DLLNUM will change each time there are forward or backward changes 200 * in binary compatibility (e.g., when a new feature is added). 201 * 202 * See libpng-manual.txt or libpng.3 for more information. The PNG 203 * specification is available as a W3C Recommendation and as an ISO 204 * Specification, <http://www.w3.org/TR/2003/REC-PNG-20031110/ 205 */ 206 207 /* 208 * COPYRIGHT NOTICE, DISCLAIMER, and LICENSE: 209 * 210 * If you modify libpng you may insert additional notices immediately following 211 * this sentence. 212 * 213 * This code is released under the libpng license. 214 * 215 * libpng versions 1.2.6, August 15, 2004, through 1.5.13, September 27, 2012, are 216 * Copyright (c) 2004, 2006-2012 Glenn Randers-Pehrson, and are 217 * distributed according to the same disclaimer and license as libpng-1.2.5 218 * with the following individual added to the list of Contributing Authors: 219 * 220 * Cosmin Truta 221 * 222 * libpng versions 1.0.7, July 1, 2000, through 1.2.5, October 3, 2002, are 223 * Copyright (c) 2000-2002 Glenn Randers-Pehrson, and are 224 * distributed according to the same disclaimer and license as libpng-1.0.6 225 * with the following individuals added to the list of Contributing Authors: 226 * 227 * Simon-Pierre Cadieux 228 * Eric S. Raymond 229 * Gilles Vollant 230 * 231 * and with the following additions to the disclaimer: 232 * 233 * There is no warranty against interference with your enjoyment of the 234 * library or against infringement. There is no warranty that our 235 * efforts or the library will fulfill any of your particular purposes 236 * or needs. This library is provided with all faults, and the entire 237 * risk of satisfactory quality, performance, accuracy, and effort is with 238 * the user. 239 * 240 * libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are 241 * Copyright (c) 1998, 1999, 2000 Glenn Randers-Pehrson, and are 242 * distributed according to the same disclaimer and license as libpng-0.96, 243 * with the following individuals added to the list of Contributing Authors: 244 * 245 * Tom Lane 246 * Glenn Randers-Pehrson 247 * Willem van Schaik 248 * 249 * libpng versions 0.89, June 1996, through 0.96, May 1997, are 250 * Copyright (c) 1996, 1997 Andreas Dilger 251 * Distributed according to the same disclaimer and license as libpng-0.88, 252 * with the following individuals added to the list of Contributing Authors: 253 * 254 * John Bowler 255 * Kevin Bracey 256 * Sam Bushell 257 * Magnus Holmgren 258 * Greg Roelofs 259 * Tom Tanner 260 * 261 * libpng versions 0.5, May 1995, through 0.88, January 1996, are 262 * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. 263 * 264 * For the purposes of this copyright and license, "Contributing Authors" 265 * is defined as the following set of individuals: 266 * 267 * Andreas Dilger 268 * Dave Martindale 269 * Guy Eric Schalnat 270 * Paul Schmidt 271 * Tim Wegner 272 * 273 * The PNG Reference Library is supplied "AS IS". The Contributing Authors 274 * and Group 42, Inc. disclaim all warranties, expressed or implied, 275 * including, without limitation, the warranties of merchantability and of 276 * fitness for any purpose. The Contributing Authors and Group 42, Inc. 277 * assume no liability for direct, indirect, incidental, special, exemplary, 278 * or consequential damages, which may result from the use of the PNG 279 * Reference Library, even if advised of the possibility of such damage. 280 * 281 * Permission is hereby granted to use, copy, modify, and distribute this 282 * source code, or portions hereof, for any purpose, without fee, subject 283 * to the following restrictions: 284 * 285 * 1. The origin of this source code must not be misrepresented. 286 * 287 * 2. Altered versions must be plainly marked as such and must not 288 * be misrepresented as being the original source. 289 * 290 * 3. This Copyright notice may not be removed or altered from 291 * any source or altered source distribution. 292 * 293 * The Contributing Authors and Group 42, Inc. specifically permit, without 294 * fee, and encourage the use of this source code as a component to 295 * supporting the PNG file format in commercial products. If you use this 296 * source code in a product, acknowledgment is not required but would be 297 * appreciated. 298 */ 299 300 /* 301 * A "png_get_copyright" function is available, for convenient use in "about" 302 * boxes and the like: 303 * 304 * printf("%s", png_get_copyright(NULL)); 305 * 306 * Also, the PNG logo (in PNG format, of course) is supplied in the 307 * files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31). 308 */ 309 310 /* 311 * Libpng is OSI Certified Open Source Software. OSI Certified is a 312 * certification mark of the Open Source Initiative. 313 */ 314 315 /* 316 * The contributing authors would like to thank all those who helped 317 * with testing, bug fixes, and patience. This wouldn't have been 318 * possible without all of you. 319 * 320 * Thanks to Frank J. T. Wojcik for helping with the documentation. 321 */ 322 323 /* 324 * Y2K compliance in libpng: 325 * ========================= 326 * 327 * September 27, 2012 328 * 329 * Since the PNG Development group is an ad-hoc body, we can't make 330 * an official declaration. 331 * 332 * This is your unofficial assurance that libpng from version 0.71 and 333 * upward through 1.5.13 are Y2K compliant. It is my belief that 334 * earlier versions were also Y2K compliant. 335 * 336 * Libpng only has two year fields. One is a 2-byte unsigned integer 337 * that will hold years up to 65535. The other holds the date in text 338 * format, and will hold years up to 9999. 339 * 340 * The integer is 341 * "png_uint_16 year" in png_time_struct. 342 * 343 * The string is 344 * "char time_buffer[29]" in png_struct. This will be no 345 * longer used in libpng-1.6.0 and will be removed from libpng-1.7.0. 346 * 347 * There are seven time-related functions: 348 * png.c: png_convert_to_rfc_1123() in png.c 349 * (formerly png_convert_to_rfc_1152() in error) 350 * png_convert_from_struct_tm() in pngwrite.c, called in pngwrite.c 351 * png_convert_from_time_t() in pngwrite.c 352 * png_get_tIME() in pngget.c 353 * png_handle_tIME() in pngrutil.c, called in pngread.c 354 * png_set_tIME() in pngset.c 355 * png_write_tIME() in pngwutil.c, called in pngwrite.c 356 * 357 * All handle dates properly in a Y2K environment. The 358 * png_convert_from_time_t() function calls gmtime() to convert from system 359 * clock time, which returns (year - 1900), which we properly convert to 360 * the full 4-digit year. There is a possibility that applications using 361 * libpng are not passing 4-digit years into the png_convert_to_rfc_1123() 362 * function, or that they are incorrectly passing only a 2-digit year 363 * instead of "year - 1900" into the png_convert_from_struct_tm() function, 364 * but this is not under our control. The libpng documentation has always 365 * stated that it works with 4-digit years, and the APIs have been 366 * documented as such. 367 * 368 * The tIME chunk itself is also Y2K compliant. It uses a 2-byte unsigned 369 * integer to hold the year, and can hold years as large as 65535. 370 * 371 * zlib, upon which libpng depends, is also Y2K compliant. It contains 372 * no date-related code. 373 * 374 * Glenn Randers-Pehrson 375 * libpng maintainer 376 * PNG Development Group 377 */ 378 379 #ifndef PNG_H 380 #define PNG_H 381 382 /* This is not the place to learn how to use libpng. The file libpng-manual.txt 383 * describes how to use libpng, and the file example.c summarizes it 384 * with some code on which to build. This file is useful for looking 385 * at the actual function definitions and structure components. 386 * 387 * If you just need to read a PNG file and don't want to read the documentation 388 * skip to the end of this file and read the section entitled 'simplified API'. 389 */ 390 391 /* Version information for png.h - this should match the version in png.c */ 392 #define PNG_LIBPNG_VER_STRING "1.5.13" 393 #define PNG_HEADER_VERSION_STRING \ 394 " libpng version 1.5.13 - September 27, 2012\n" 395 396 #define PNG_LIBPNG_VER_SONUM 15 397 #define PNG_LIBPNG_VER_DLLNUM 15 398 399 /* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */ 400 #define PNG_LIBPNG_VER_MAJOR 1 401 #define PNG_LIBPNG_VER_MINOR 5 402 #define PNG_LIBPNG_VER_RELEASE 13 403 404 /* This should match the numeric part of the final component of 405 * PNG_LIBPNG_VER_STRING, omitting any leading zero: 406 */ 407 408 #define PNG_LIBPNG_VER_BUILD 0 409 410 /* Release Status */ 411 #define PNG_LIBPNG_BUILD_ALPHA 1 412 #define PNG_LIBPNG_BUILD_BETA 2 413 #define PNG_LIBPNG_BUILD_RC 3 414 #define PNG_LIBPNG_BUILD_STABLE 4 415 #define PNG_LIBPNG_BUILD_RELEASE_STATUS_MASK 7 416 417 /* Release-Specific Flags */ 418 #define PNG_LIBPNG_BUILD_PATCH 8 /* Can be OR'ed with 419 PNG_LIBPNG_BUILD_STABLE only */ 420 #define PNG_LIBPNG_BUILD_PRIVATE 16 /* Cannot be OR'ed with 421 PNG_LIBPNG_BUILD_SPECIAL */ 422 #define PNG_LIBPNG_BUILD_SPECIAL 32 /* Cannot be OR'ed with 423 PNG_LIBPNG_BUILD_PRIVATE */ 424 425 #define PNG_LIBPNG_BUILD_BASE_TYPE PNG_LIBPNG_BUILD_STABLE 426 427 /* Careful here. At one time, Guy wanted to use 082, but that would be octal. 428 * We must not include leading zeros. 429 * Versions 0.7 through 1.0.0 were in the range 0 to 100 here (only 430 * version 1.0.0 was mis-numbered 100 instead of 10000). From 431 * version 1.0.1 it's xxyyzz, where x=major, y=minor, z=release 432 */ 433 #define PNG_LIBPNG_VER 10513 /* 1.5.13 */ 434 435 /* Library configuration: these options cannot be changed after 436 * the library has been built. 437 */ 438 #ifndef PNGLCONF_H 439 /* If pnglibconf.h is missing, you can 440 * copy scripts/pnglibconf.h.prebuilt to pnglibconf.h 441 */ 442 # include "pnglibconf.h" 443 #endif 444 445 #ifndef PNG_VERSION_INFO_ONLY 446 # ifndef PNG_BUILDING_SYMBOL_TABLE 447 /* 448 * Standard header files (not needed for the version info or while 449 * building symbol table -- see scripts/pnglibconf.dfa) 450 */ 451 # ifdef PNG_SETJMP_SUPPORTED 452 # include <setjmp.h> 453 # endif 454 455 /* Need the time information for converting tIME chunks, it 456 * defines struct tm: 457 */ 458 # ifdef PNG_CONVERT_tIME_SUPPORTED 459 /* "time.h" functions are not supported on all operating systems */ 460 # include <time.h> 461 # endif 462 # endif 463 464 /* Machine specific configuration. */ 465 # include "pngconf.h" 466 #endif 467 468 /* 469 * Added at libpng-1.2.8 470 * 471 * Ref MSDN: Private as priority over Special 472 * VS_FF_PRIVATEBUILD File *was not* built using standard release 473 * procedures. If this value is given, the StringFileInfo block must 474 * contain a PrivateBuild string. 475 * 476 * VS_FF_SPECIALBUILD File *was* built by the original company using 477 * standard release procedures but is a variation of the standard 478 * file of the same version number. If this value is given, the 479 * StringFileInfo block must contain a SpecialBuild string. 480 */ 481 482 #ifdef PNG_USER_PRIVATEBUILD /* From pnglibconf.h */ 483 # define PNG_LIBPNG_BUILD_TYPE \ 484 (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_PRIVATE) 485 #else 486 # ifdef PNG_LIBPNG_SPECIALBUILD 487 # define PNG_LIBPNG_BUILD_TYPE \ 488 (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_SPECIAL) 489 # else 490 # define PNG_LIBPNG_BUILD_TYPE (PNG_LIBPNG_BUILD_BASE_TYPE) 491 # endif 492 #endif 493 494 #ifndef PNG_VERSION_INFO_ONLY 495 496 /* Inhibit C++ name-mangling for libpng functions but not for system calls. */ 497 #ifdef __cplusplus 498 extern "C" { 499 #endif /* __cplusplus */ 500 501 /* Version information for C files, stored in png.c. This had better match 502 * the version above. 503 */ 504 #define png_libpng_ver png_get_header_ver(NULL) 505 506 /* This file is arranged in several sections: 507 * 508 * 1. Any configuration options that can be specified by for the application 509 * code when it is built. (Build time configuration is in pnglibconf.h) 510 * 2. Type definitions (base types are defined in pngconf.h), structure 511 * definitions. 512 * 3. Exported library functions. 513 * 514 * The library source code has additional files (principally pngpriv.h) that 515 * allow configuration of the library. 516 */ 517 /* Section 1: run time configuration 518 * See pnglibconf.h for build time configuration 519 * 520 * Run time configuration allows the application to choose between 521 * implementations of certain arithmetic APIs. The default is set 522 * at build time and recorded in pnglibconf.h, but it is safe to 523 * override these (and only these) settings. Note that this won't 524 * change what the library does, only application code, and the 525 * settings can (and probably should) be made on a per-file basis 526 * by setting the #defines before including png.h 527 * 528 * Use macros to read integers from PNG data or use the exported 529 * functions? 530 * PNG_USE_READ_MACROS: use the macros (see below) Note that 531 * the macros evaluate their argument multiple times. 532 * PNG_NO_USE_READ_MACROS: call the relevant library function. 533 * 534 * Use the alternative algorithm for compositing alpha samples that 535 * does not use division? 536 * PNG_READ_COMPOSITE_NODIV_SUPPORTED: use the 'no division' 537 * algorithm. 538 * PNG_NO_READ_COMPOSITE_NODIV: use the 'division' algorithm. 539 * 540 * How to handle benign errors if PNG_ALLOW_BENIGN_ERRORS is 541 * false? 542 * PNG_ALLOW_BENIGN_ERRORS: map calls to the benign error 543 * APIs to png_warning. 544 * Otherwise the calls are mapped to png_error. 545 */ 546 547 /* Section 2: type definitions, including structures and compile time 548 * constants. 549 * See pngconf.h for base types that vary by machine/system 550 */ 551 552 /* This triggers a compiler error in png.c, if png.c and png.h 553 * do not agree upon the version number. 554 */ 555 typedef char* png_libpng_version_1_5_13; 556 557 /* Three color definitions. The order of the red, green, and blue, (and the 558 * exact size) is not important, although the size of the fields need to 559 * be png_byte or png_uint_16 (as defined below). 560 */ 561 typedef struct png_color_struct 562 { 563 png_byte red; 564 png_byte green; 565 png_byte blue; 566 } png_color; 567 typedef png_color FAR * png_colorp; 568 typedef PNG_CONST png_color FAR * png_const_colorp; 569 typedef png_color FAR * FAR * png_colorpp; 570 571 typedef struct png_color_16_struct 572 { 573 png_byte index; /* used for palette files */ 574 png_uint_16 red; /* for use in red green blue files */ 575 png_uint_16 green; 576 png_uint_16 blue; 577 png_uint_16 gray; /* for use in grayscale files */ 578 } png_color_16; 579 typedef png_color_16 FAR * png_color_16p; 580 typedef PNG_CONST png_color_16 FAR * png_const_color_16p; 581 typedef png_color_16 FAR * FAR * png_color_16pp; 582 583 typedef struct png_color_8_struct 584 { 585 png_byte red; /* for use in red green blue files */ 586 png_byte green; 587 png_byte blue; 588 png_byte gray; /* for use in grayscale files */ 589 png_byte alpha; /* for alpha channel files */ 590 } png_color_8; 591 typedef png_color_8 FAR * png_color_8p; 592 typedef PNG_CONST png_color_8 FAR * png_const_color_8p; 593 typedef png_color_8 FAR * FAR * png_color_8pp; 594 595 /* 596 * The following two structures are used for the in-core representation 597 * of sPLT chunks. 598 */ 599 typedef struct png_sPLT_entry_struct 600 { 601 png_uint_16 red; 602 png_uint_16 green; 603 png_uint_16 blue; 604 png_uint_16 alpha; 605 png_uint_16 frequency; 606 } png_sPLT_entry; 607 typedef png_sPLT_entry FAR * png_sPLT_entryp; 608 typedef PNG_CONST png_sPLT_entry FAR * png_const_sPLT_entryp; 609 typedef png_sPLT_entry FAR * FAR * png_sPLT_entrypp; 610 611 /* When the depth of the sPLT palette is 8 bits, the color and alpha samples 612 * occupy the LSB of their respective members, and the MSB of each member 613 * is zero-filled. The frequency member always occupies the full 16 bits. 614 */ 615 616 typedef struct png_sPLT_struct 617 { 618 png_charp name; /* palette name */ 619 png_byte depth; /* depth of palette samples */ 620 png_sPLT_entryp entries; /* palette entries */ 621 png_int_32 nentries; /* number of palette entries */ 622 } png_sPLT_t; 623 typedef png_sPLT_t FAR * png_sPLT_tp; 624 typedef PNG_CONST png_sPLT_t FAR * png_const_sPLT_tp; 625 typedef png_sPLT_t FAR * FAR * png_sPLT_tpp; 626 627 #ifdef PNG_TEXT_SUPPORTED 628 /* png_text holds the contents of a text/ztxt/itxt chunk in a PNG file, 629 * and whether that contents is compressed or not. The "key" field 630 * points to a regular zero-terminated C string. The "text" fields can be a 631 * regular C string, an empty string, or a NULL pointer. 632 * However, the structure returned by png_get_text() will always contain 633 * the "text" field as a regular zero-terminated C string (possibly 634 * empty), never a NULL pointer, so it can be safely used in printf() and 635 * other string-handling functions. Note that the "itxt_length", "lang", and 636 * "lang_key" members of the structure only exist when the library is built 637 * with iTXt chunk support. Prior to libpng-1.4.0 the library was built by 638 * default without iTXt support. Also note that when iTXt *is* supported, 639 * the "lang" and "lang_key" fields contain NULL pointers when the 640 * "compression" field contains * PNG_TEXT_COMPRESSION_NONE or 641 * PNG_TEXT_COMPRESSION_zTXt. Note that the "compression value" is not the 642 * same as what appears in the PNG tEXt/zTXt/iTXt chunk's "compression flag" 643 * which is always 0 or 1, or its "compression method" which is always 0. 644 */ 645 typedef struct png_text_struct 646 { 647 int compression; /* compression value: 648 -1: tEXt, none 649 0: zTXt, deflate 650 1: iTXt, none 651 2: iTXt, deflate */ 652 png_charp key; /* keyword, 1-79 character description of "text" */ 653 png_charp text; /* comment, may be an empty string (ie "") 654 or a NULL pointer */ 655 png_size_t text_length; /* length of the text string */ 656 png_size_t itxt_length; /* length of the itxt string */ 657 png_charp lang; /* language code, 0-79 characters 658 or a NULL pointer */ 659 png_charp lang_key; /* keyword translated UTF-8 string, 0 or more 660 chars or a NULL pointer */ 661 } png_text; 662 typedef png_text FAR * png_textp; 663 typedef PNG_CONST png_text FAR * png_const_textp; 664 typedef png_text FAR * FAR * png_textpp; 665 #endif 666 667 /* Supported compression types for text in PNG files (tEXt, and zTXt). 668 * The values of the PNG_TEXT_COMPRESSION_ defines should NOT be changed. */ 669 #define PNG_TEXT_COMPRESSION_NONE_WR -3 670 #define PNG_TEXT_COMPRESSION_zTXt_WR -2 671 #define PNG_TEXT_COMPRESSION_NONE -1 672 #define PNG_TEXT_COMPRESSION_zTXt 0 673 #define PNG_ITXT_COMPRESSION_NONE 1 674 #define PNG_ITXT_COMPRESSION_zTXt 2 675 #define PNG_TEXT_COMPRESSION_LAST 3 /* Not a valid value */ 676 677 /* png_time is a way to hold the time in an machine independent way. 678 * Two conversions are provided, both from time_t and struct tm. There 679 * is no portable way to convert to either of these structures, as far 680 * as I know. If you know of a portable way, send it to me. As a side 681 * note - PNG has always been Year 2000 compliant! 682 */ 683 typedef struct png_time_struct 684 { 685 png_uint_16 year; /* full year, as in, 1995 */ 686 png_byte month; /* month of year, 1 - 12 */ 687 png_byte day; /* day of month, 1 - 31 */ 688 png_byte hour; /* hour of day, 0 - 23 */ 689 png_byte minute; /* minute of hour, 0 - 59 */ 690 png_byte second; /* second of minute, 0 - 60 (for leap seconds) */ 691 } png_time; 692 typedef png_time FAR * png_timep; 693 typedef PNG_CONST png_time FAR * png_const_timep; 694 typedef png_time FAR * FAR * png_timepp; 695 696 #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED) || \ 697 defined(PNG_HANDLE_AS_UNKNOWN_SUPPORTED) 698 /* png_unknown_chunk is a structure to hold queued chunks for which there is 699 * no specific support. The idea is that we can use this to queue 700 * up private chunks for output even though the library doesn't actually 701 * know about their semantics. 702 */ 703 typedef struct png_unknown_chunk_t 704 { 705 png_byte name[5]; 706 png_byte *data; 707 png_size_t size; 708 709 /* libpng-using applications should NOT directly modify this byte. */ 710 png_byte location; /* mode of operation at read time */ 711 } 712 713 714 png_unknown_chunk; 715 typedef png_unknown_chunk FAR * png_unknown_chunkp; 716 typedef PNG_CONST png_unknown_chunk FAR * png_const_unknown_chunkp; 717 typedef png_unknown_chunk FAR * FAR * png_unknown_chunkpp; 718 #endif 719 720 /* Values for the unknown chunk location byte */ 721 722 #define PNG_HAVE_IHDR 0x01 723 #define PNG_HAVE_PLTE 0x02 724 #define PNG_AFTER_IDAT 0x08 725 726 /* The complete definition of png_info has, as of libpng-1.5.0, 727 * been moved into a separate header file that is not accessible to 728 * applications. Read libpng-manual.txt or libpng.3 for more info. 729 */ 730 typedef struct png_info_def png_info; 731 typedef png_info FAR * png_infop; 732 typedef PNG_CONST png_info FAR * png_const_infop; 733 typedef png_info FAR * FAR * png_infopp; 734 735 /* Maximum positive integer used in PNG is (2^31)-1 */ 736 #define PNG_UINT_31_MAX ((png_uint_32)0x7fffffffL) 737 #define PNG_UINT_32_MAX ((png_uint_32)(-1)) 738 #define PNG_SIZE_MAX ((png_size_t)(-1)) 739 740 /* These are constants for fixed point values encoded in the 741 * PNG specification manner (x100000) 742 */ 743 #define PNG_FP_1 100000 744 #define PNG_FP_HALF 50000 745 #define PNG_FP_MAX ((png_fixed_point)0x7fffffffL) 746 #define PNG_FP_MIN (-PNG_FP_MAX) 747 748 /* These describe the color_type field in png_info. */ 749 /* color type masks */ 750 #define PNG_COLOR_MASK_PALETTE 1 751 #define PNG_COLOR_MASK_COLOR 2 752 #define PNG_COLOR_MASK_ALPHA 4 753 754 /* color types. Note that not all combinations are legal */ 755 #define PNG_COLOR_TYPE_GRAY 0 756 #define PNG_COLOR_TYPE_PALETTE (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE) 757 #define PNG_COLOR_TYPE_RGB (PNG_COLOR_MASK_COLOR) 758 #define PNG_COLOR_TYPE_RGB_ALPHA (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_ALPHA) 759 #define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA) 760 /* aliases */ 761 #define PNG_COLOR_TYPE_RGBA PNG_COLOR_TYPE_RGB_ALPHA 762 #define PNG_COLOR_TYPE_GA PNG_COLOR_TYPE_GRAY_ALPHA 763 764 /* This is for compression type. PNG 1.0-1.2 only define the single type. */ 765 #define PNG_COMPRESSION_TYPE_BASE 0 /* Deflate method 8, 32K window */ 766 #define PNG_COMPRESSION_TYPE_DEFAULT PNG_COMPRESSION_TYPE_BASE 767 768 /* This is for filter type. PNG 1.0-1.2 only define the single type. */ 769 #define PNG_FILTER_TYPE_BASE 0 /* Single row per-byte filtering */ 770 #define PNG_INTRAPIXEL_DIFFERENCING 64 /* Used only in MNG datastreams */ 771 #define PNG_FILTER_TYPE_DEFAULT PNG_FILTER_TYPE_BASE 772 773 /* These are for the interlacing type. These values should NOT be changed. */ 774 #define PNG_INTERLACE_NONE 0 /* Non-interlaced image */ 775 #define PNG_INTERLACE_ADAM7 1 /* Adam7 interlacing */ 776 #define PNG_INTERLACE_LAST 2 /* Not a valid value */ 777 778 /* These are for the oFFs chunk. These values should NOT be changed. */ 779 #define PNG_OFFSET_PIXEL 0 /* Offset in pixels */ 780 #define PNG_OFFSET_MICROMETER 1 /* Offset in micrometers (1/10^6 meter) */ 781 #define PNG_OFFSET_LAST 2 /* Not a valid value */ 782 783 /* These are for the pCAL chunk. These values should NOT be changed. */ 784 #define PNG_EQUATION_LINEAR 0 /* Linear transformation */ 785 #define PNG_EQUATION_BASE_E 1 /* Exponential base e transform */ 786 #define PNG_EQUATION_ARBITRARY 2 /* Arbitrary base exponential transform */ 787 #define PNG_EQUATION_HYPERBOLIC 3 /* Hyperbolic sine transformation */ 788 #define PNG_EQUATION_LAST 4 /* Not a valid value */ 789 790 /* These are for the sCAL chunk. These values should NOT be changed. */ 791 #define PNG_SCALE_UNKNOWN 0 /* unknown unit (image scale) */ 792 #define PNG_SCALE_METER 1 /* meters per pixel */ 793 #define PNG_SCALE_RADIAN 2 /* radians per pixel */ 794 #define PNG_SCALE_LAST 3 /* Not a valid value */ 795 796 /* These are for the pHYs chunk. These values should NOT be changed. */ 797 #define PNG_RESOLUTION_UNKNOWN 0 /* pixels/unknown unit (aspect ratio) */ 798 #define PNG_RESOLUTION_METER 1 /* pixels/meter */ 799 #define PNG_RESOLUTION_LAST 2 /* Not a valid value */ 800 801 /* These are for the sRGB chunk. These values should NOT be changed. */ 802 #define PNG_sRGB_INTENT_PERCEPTUAL 0 803 #define PNG_sRGB_INTENT_RELATIVE 1 804 #define PNG_sRGB_INTENT_SATURATION 2 805 #define PNG_sRGB_INTENT_ABSOLUTE 3 806 #define PNG_sRGB_INTENT_LAST 4 /* Not a valid value */ 807 808 /* This is for text chunks */ 809 #define PNG_KEYWORD_MAX_LENGTH 79 810 811 /* Maximum number of entries in PLTE/sPLT/tRNS arrays */ 812 #define PNG_MAX_PALETTE_LENGTH 256 813 814 /* These determine if an ancillary chunk's data has been successfully read 815 * from the PNG header, or if the application has filled in the corresponding 816 * data in the info_struct to be written into the output file. The values 817 * of the PNG_INFO_<chunk> defines should NOT be changed. 818 */ 819 #define PNG_INFO_gAMA 0x0001 820 #define PNG_INFO_sBIT 0x0002 821 #define PNG_INFO_cHRM 0x0004 822 #define PNG_INFO_PLTE 0x0008 823 #define PNG_INFO_tRNS 0x0010 824 #define PNG_INFO_bKGD 0x0020 825 #define PNG_INFO_hIST 0x0040 826 #define PNG_INFO_pHYs 0x0080 827 #define PNG_INFO_oFFs 0x0100 828 #define PNG_INFO_tIME 0x0200 829 #define PNG_INFO_pCAL 0x0400 830 #define PNG_INFO_sRGB 0x0800 /* GR-P, 0.96a */ 831 #define PNG_INFO_iCCP 0x1000 /* ESR, 1.0.6 */ 832 #define PNG_INFO_sPLT 0x2000 /* ESR, 1.0.6 */ 833 #define PNG_INFO_sCAL 0x4000 /* ESR, 1.0.6 */ 834 #define PNG_INFO_IDAT 0x8000 /* ESR, 1.0.6 */ 835 836 /* This is used for the transformation routines, as some of them 837 * change these values for the row. It also should enable using 838 * the routines for other purposes. 839 */ 840 typedef struct png_row_info_struct 841 { 842 png_uint_32 width; /* width of row */ 843 png_size_t rowbytes; /* number of bytes in row */ 844 png_byte color_type; /* color type of row */ 845 png_byte bit_depth; /* bit depth of row */ 846 png_byte channels; /* number of channels (1, 2, 3, or 4) */ 847 png_byte pixel_depth; /* bits per pixel (depth * channels) */ 848 } png_row_info; 849 850 typedef png_row_info FAR * png_row_infop; 851 typedef png_row_info FAR * FAR * png_row_infopp; 852 853 /* The complete definition of png_struct has, as of libpng-1.5.0, 854 * been moved into a separate header file that is not accessible to 855 * applications. Read libpng-manual.txt or libpng.3 for more info. 856 */ 857 typedef struct png_struct_def png_struct; 858 typedef PNG_CONST png_struct FAR * png_const_structp; 859 typedef png_struct FAR * png_structp; 860 861 /* These are the function types for the I/O functions and for the functions 862 * that allow the user to override the default I/O functions with his or her 863 * own. The png_error_ptr type should match that of user-supplied warning 864 * and error functions, while the png_rw_ptr type should match that of the 865 * user read/write data functions. Note that the 'write' function must not 866 * modify the buffer it is passed. The 'read' function, on the other hand, is 867 * expected to return the read data in the buffer. 868 */ 869 typedef PNG_CALLBACK(void, *png_error_ptr, (png_structp, png_const_charp)); 870 typedef PNG_CALLBACK(void, *png_rw_ptr, (png_structp, png_bytep, png_size_t)); 871 typedef PNG_CALLBACK(void, *png_flush_ptr, (png_structp)); 872 typedef PNG_CALLBACK(void, *png_read_status_ptr, (png_structp, png_uint_32, 873 int)); 874 typedef PNG_CALLBACK(void, *png_write_status_ptr, (png_structp, png_uint_32, 875 int)); 876 877 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED 878 typedef PNG_CALLBACK(void, *png_progressive_info_ptr, (png_structp, png_infop)); 879 typedef PNG_CALLBACK(void, *png_progressive_end_ptr, (png_structp, png_infop)); 880 881 /* The following callback receives png_uint_32 row_number, int pass for the 882 * png_bytep data of the row. When transforming an interlaced image the 883 * row number is the row number within the sub-image of the interlace pass, so 884 * the value will increase to the height of the sub-image (not the full image) 885 * then reset to 0 for the next pass. 886 * 887 * Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to 888 * find the output pixel (x,y) given an interlaced sub-image pixel 889 * (row,col,pass). (See below for these macros.) 890 */ 891 typedef PNG_CALLBACK(void, *png_progressive_row_ptr, (png_structp, png_bytep, 892 png_uint_32, int)); 893 #endif 894 895 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \ 896 defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) 897 typedef PNG_CALLBACK(void, *png_user_transform_ptr, (png_structp, png_row_infop, 898 png_bytep)); 899 #endif 900 901 #ifdef PNG_USER_CHUNKS_SUPPORTED 902 typedef PNG_CALLBACK(int, *png_user_chunk_ptr, (png_structp, 903 png_unknown_chunkp)); 904 #endif 905 #ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED 906 typedef PNG_CALLBACK(void, *png_unknown_chunk_ptr, (png_structp)); 907 #endif 908 909 #ifdef PNG_SETJMP_SUPPORTED 910 /* This must match the function definition in <setjmp.h>, and the application 911 * must include this before png.h to obtain the definition of jmp_buf. The 912 * function is required to be PNG_NORETURN, but this is not checked. If the 913 * function does return the application will crash via an abort() or similar 914 * system level call. 915 * 916 * If you get a warning here while building the library you may need to make 917 * changes to ensure that pnglibconf.h records the calling convention used by 918 * your compiler. This may be very difficult - try using a different compiler 919 * to build the library! 920 */ 921 PNG_FUNCTION(void, (PNGCAPI *png_longjmp_ptr), PNGARG((jmp_buf, int)), typedef); 922 #endif 923 924 /* Transform masks for the high-level interface */ 925 #define PNG_TRANSFORM_IDENTITY 0x0000 /* read and write */ 926 #define PNG_TRANSFORM_STRIP_16 0x0001 /* read only */ 927 #define PNG_TRANSFORM_STRIP_ALPHA 0x0002 /* read only */ 928 #define PNG_TRANSFORM_PACKING 0x0004 /* read and write */ 929 #define PNG_TRANSFORM_PACKSWAP 0x0008 /* read and write */ 930 #define PNG_TRANSFORM_EXPAND 0x0010 /* read only */ 931 #define PNG_TRANSFORM_INVERT_MONO 0x0020 /* read and write */ 932 #define PNG_TRANSFORM_SHIFT 0x0040 /* read and write */ 933 #define PNG_TRANSFORM_BGR 0x0080 /* read and write */ 934 #define PNG_TRANSFORM_SWAP_ALPHA 0x0100 /* read and write */ 935 #define PNG_TRANSFORM_SWAP_ENDIAN 0x0200 /* read and write */ 936 #define PNG_TRANSFORM_INVERT_ALPHA 0x0400 /* read and write */ 937 #define PNG_TRANSFORM_STRIP_FILLER 0x0800 /* write only */ 938 /* Added to libpng-1.2.34 */ 939 #define PNG_TRANSFORM_STRIP_FILLER_BEFORE PNG_TRANSFORM_STRIP_FILLER 940 #define PNG_TRANSFORM_STRIP_FILLER_AFTER 0x1000 /* write only */ 941 /* Added to libpng-1.4.0 */ 942 #define PNG_TRANSFORM_GRAY_TO_RGB 0x2000 /* read only */ 943 /* Added to libpng-1.5.4 */ 944 #define PNG_TRANSFORM_EXPAND_16 0x4000 /* read only */ 945 #define PNG_TRANSFORM_SCALE_16 0x8000 /* read only */ 946 947 /* Flags for MNG supported features */ 948 #define PNG_FLAG_MNG_EMPTY_PLTE 0x01 949 #define PNG_FLAG_MNG_FILTER_64 0x04 950 #define PNG_ALL_MNG_FEATURES 0x05 951 952 /* NOTE: prior to 1.5 these functions had no 'API' style declaration, 953 * this allowed the zlib default functions to be used on Windows 954 * platforms. In 1.5 the zlib default malloc (which just calls malloc and 955 * ignores the first argument) should be completely compatible with the 956 * following. 957 */ 958 typedef PNG_CALLBACK(png_voidp, *png_malloc_ptr, (png_structp, 959 png_alloc_size_t)); 960 typedef PNG_CALLBACK(void, *png_free_ptr, (png_structp, png_voidp)); 961 962 typedef png_struct FAR * FAR * png_structpp; 963 964 /* Section 3: exported functions 965 * Here are the function definitions most commonly used. This is not 966 * the place to find out how to use libpng. See libpng-manual.txt for the 967 * full explanation, see example.c for the summary. This just provides 968 * a simple one line description of the use of each function. 969 * 970 * The PNG_EXPORT() and PNG_EXPORTA() macros used below are defined in 971 * pngconf.h and in the *.dfn files in the scripts directory. 972 * 973 * PNG_EXPORT(ordinal, type, name, (args)); 974 * 975 * ordinal: ordinal that is used while building 976 * *.def files. The ordinal value is only 977 * relevant when preprocessing png.h with 978 * the *.dfn files for building symbol table 979 * entries, and are removed by pngconf.h. 980 * type: return type of the function 981 * name: function name 982 * args: function arguments, with types 983 * 984 * When we wish to append attributes to a function prototype we use 985 * the PNG_EXPORTA() macro instead. 986 * 987 * PNG_EXPORTA(ordinal, type, name, (args), attributes); 988 * 989 * ordinal, type, name, and args: same as in PNG_EXPORT(). 990 * attributes: function attributes 991 */ 992 993 /* Returns the version number of the library */ 994 PNG_EXPORT(1, png_uint_32, png_access_version_number, (void)); 995 996 /* Tell lib we have already handled the first <num_bytes> magic bytes. 997 * Handling more than 8 bytes from the beginning of the file is an error. 998 */ 999 PNG_EXPORT(2, void, png_set_sig_bytes, (png_structp png_ptr, int num_bytes)); 1000 1001 /* Check sig[start] through sig[start + num_to_check - 1] to see if it's a 1002 * PNG file. Returns zero if the supplied bytes match the 8-byte PNG 1003 * signature, and non-zero otherwise. Having num_to_check == 0 or 1004 * start > 7 will always fail (ie return non-zero). 1005 */ 1006 PNG_EXPORT(3, int, png_sig_cmp, (png_const_bytep sig, png_size_t start, 1007 png_size_t num_to_check)); 1008 1009 /* Simple signature checking function. This is the same as calling 1010 * png_check_sig(sig, n) := !png_sig_cmp(sig, 0, n). 1011 */ 1012 #define png_check_sig(sig, n) !png_sig_cmp((sig), 0, (n)) 1013 1014 /* Allocate and initialize png_ptr struct for reading, and any other memory. */ 1015 PNG_EXPORTA(4, png_structp, png_create_read_struct, 1016 (png_const_charp user_png_ver, png_voidp error_ptr, 1017 png_error_ptr error_fn, png_error_ptr warn_fn), 1018 PNG_ALLOCATED); 1019 1020 /* Allocate and initialize png_ptr struct for writing, and any other memory */ 1021 PNG_EXPORTA(5, png_structp, png_create_write_struct, 1022 (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn, 1023 png_error_ptr warn_fn), 1024 PNG_ALLOCATED); 1025 1026 PNG_EXPORT(6, png_size_t, png_get_compression_buffer_size, 1027 (png_const_structp png_ptr)); 1028 1029 PNG_EXPORT(7, void, png_set_compression_buffer_size, (png_structp png_ptr, 1030 png_size_t size)); 1031 1032 /* Moved from pngconf.h in 1.4.0 and modified to ensure setjmp/longjmp 1033 * match up. 1034 */ 1035 #ifdef PNG_SETJMP_SUPPORTED 1036 /* This function returns the jmp_buf built in to *png_ptr. It must be 1037 * supplied with an appropriate 'longjmp' function to use on that jmp_buf 1038 * unless the default error function is overridden in which case NULL is 1039 * acceptable. The size of the jmp_buf is checked against the actual size 1040 * allocated by the library - the call will return NULL on a mismatch 1041 * indicating an ABI mismatch. 1042 */ 1043 PNG_EXPORT(8, jmp_buf*, png_set_longjmp_fn, (png_structp png_ptr, 1044 png_longjmp_ptr longjmp_fn, size_t jmp_buf_size)); 1045 # define png_jmpbuf(png_ptr) \ 1046 (*png_set_longjmp_fn((png_ptr), longjmp, sizeof (jmp_buf))) 1047 #else 1048 # define png_jmpbuf(png_ptr) \ 1049 (LIBPNG_WAS_COMPILED_WITH__PNG_NO_SETJMP) 1050 #endif 1051 /* This function should be used by libpng applications in place of 1052 * longjmp(png_ptr->jmpbuf, val). If longjmp_fn() has been set, it 1053 * will use it; otherwise it will call PNG_ABORT(). This function was 1054 * added in libpng-1.5.0. 1055 */ 1056 PNG_EXPORTA(9, void, png_longjmp, (png_structp png_ptr, int val), 1057 PNG_NORETURN); 1058 1059 #ifdef PNG_READ_SUPPORTED 1060 /* Reset the compression stream */ 1061 PNG_EXPORT(10, int, png_reset_zstream, (png_structp png_ptr)); 1062 #endif 1063 1064 /* New functions added in libpng-1.0.2 (not enabled by default until 1.2.0) */ 1065 #ifdef PNG_USER_MEM_SUPPORTED 1066 PNG_EXPORTA(11, png_structp, png_create_read_struct_2, 1067 (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn, 1068 png_error_ptr warn_fn, 1069 png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn), 1070 PNG_ALLOCATED); 1071 PNG_EXPORTA(12, png_structp, png_create_write_struct_2, 1072 (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn, 1073 png_error_ptr warn_fn, 1074 png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn), 1075 PNG_ALLOCATED); 1076 #endif 1077 1078 /* Write the PNG file signature. */ 1079 PNG_EXPORT(13, void, png_write_sig, (png_structp png_ptr)); 1080 1081 /* Write a PNG chunk - size, type, (optional) data, CRC. */ 1082 PNG_EXPORT(14, void, png_write_chunk, (png_structp png_ptr, png_const_bytep 1083 chunk_name, png_const_bytep data, png_size_t length)); 1084 1085 /* Write the start of a PNG chunk - length and chunk name. */ 1086 PNG_EXPORT(15, void, png_write_chunk_start, (png_structp png_ptr, 1087 png_const_bytep chunk_name, png_uint_32 length)); 1088 1089 /* Write the data of a PNG chunk started with png_write_chunk_start(). */ 1090 PNG_EXPORT(16, void, png_write_chunk_data, (png_structp png_ptr, 1091 png_const_bytep data, png_size_t length)); 1092 1093 /* Finish a chunk started with png_write_chunk_start() (includes CRC). */ 1094 PNG_EXPORT(17, void, png_write_chunk_end, (png_structp png_ptr)); 1095 1096 /* Allocate and initialize the info structure */ 1097 PNG_EXPORTA(18, png_infop, png_create_info_struct, (png_structp png_ptr), 1098 PNG_ALLOCATED); 1099 1100 PNG_EXPORT(19, void, png_info_init_3, (png_infopp info_ptr, 1101 png_size_t png_info_struct_size)); 1102 1103 /* Writes all the PNG information before the image. */ 1104 PNG_EXPORT(20, void, png_write_info_before_PLTE, 1105 (png_structp png_ptr, png_infop info_ptr)); 1106 PNG_EXPORT(21, void, png_write_info, 1107 (png_structp png_ptr, png_infop info_ptr)); 1108 1109 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED 1110 /* Read the information before the actual image data. */ 1111 PNG_EXPORT(22, void, png_read_info, 1112 (png_structp png_ptr, png_infop info_ptr)); 1113 #endif 1114 1115 #ifdef PNG_TIME_RFC1123_SUPPORTED 1116 PNG_EXPORT(23, png_const_charp, png_convert_to_rfc1123, 1117 (png_structp png_ptr, 1118 png_const_timep ptime)); 1119 #endif 1120 1121 #ifdef PNG_CONVERT_tIME_SUPPORTED 1122 /* Convert from a struct tm to png_time */ 1123 PNG_EXPORT(24, void, png_convert_from_struct_tm, (png_timep ptime, 1124 PNG_CONST struct tm FAR * ttime)); 1125 1126 /* Convert from time_t to png_time. Uses gmtime() */ 1127 PNG_EXPORT(25, void, png_convert_from_time_t, 1128 (png_timep ptime, time_t ttime)); 1129 #endif /* PNG_CONVERT_tIME_SUPPORTED */ 1130 1131 #ifdef PNG_READ_EXPAND_SUPPORTED 1132 /* Expand data to 24-bit RGB, or 8-bit grayscale, with alpha if available. */ 1133 PNG_EXPORT(26, void, png_set_expand, (png_structp png_ptr)); 1134 PNG_EXPORT(27, void, png_set_expand_gray_1_2_4_to_8, (png_structp png_ptr)); 1135 PNG_EXPORT(28, void, png_set_palette_to_rgb, (png_structp png_ptr)); 1136 PNG_EXPORT(29, void, png_set_tRNS_to_alpha, (png_structp png_ptr)); 1137 #endif 1138 1139 #ifdef PNG_READ_EXPAND_16_SUPPORTED 1140 /* Expand to 16-bit channels, forces conversion of palette to RGB and expansion 1141 * of a tRNS chunk if present. 1142 */ 1143 PNG_EXPORT(221, void, png_set_expand_16, (png_structp png_ptr)); 1144 #endif 1145 1146 #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED) 1147 /* Use blue, green, red order for pixels. */ 1148 PNG_EXPORT(30, void, png_set_bgr, (png_structp png_ptr)); 1149 #endif 1150 1151 #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED 1152 /* Expand the grayscale to 24-bit RGB if necessary. */ 1153 PNG_EXPORT(31, void, png_set_gray_to_rgb, (png_structp png_ptr)); 1154 #endif 1155 1156 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED 1157 /* Reduce RGB to grayscale. */ 1158 #define PNG_ERROR_ACTION_NONE 1 1159 #define PNG_ERROR_ACTION_WARN 2 1160 #define PNG_ERROR_ACTION_ERROR 3 1161 #define PNG_RGB_TO_GRAY_DEFAULT (-1)/*for red/green coefficients*/ 1162 1163 PNG_FP_EXPORT(32, void, png_set_rgb_to_gray, (png_structp png_ptr, 1164 int error_action, double red, double green)) 1165 PNG_FIXED_EXPORT(33, void, png_set_rgb_to_gray_fixed, (png_structp png_ptr, 1166 int error_action, png_fixed_point red, png_fixed_point green)) 1167 1168 PNG_EXPORT(34, png_byte, png_get_rgb_to_gray_status, (png_const_structp 1169 png_ptr)); 1170 #endif 1171 1172 #ifdef PNG_BUILD_GRAYSCALE_PALETTE_SUPPORTED 1173 PNG_EXPORT(35, void, png_build_grayscale_palette, (int bit_depth, 1174 png_colorp palette)); 1175 #endif 1176 1177 #ifdef PNG_READ_ALPHA_MODE_SUPPORTED 1178 /* How the alpha channel is interpreted - this affects how the color channels of 1179 * a PNG file are returned when an alpha channel, or tRNS chunk in a palette 1180 * file, is present. 1181 * 1182 * This has no effect on the way pixels are written into a PNG output 1183 * datastream. The color samples in a PNG datastream are never premultiplied 1184 * with the alpha samples. 1185 * 1186 * The default is to return data according to the PNG specification: the alpha 1187 * channel is a linear measure of the contribution of the pixel to the 1188 * corresponding composited pixel. The gamma encoded color channels must be 1189 * scaled according to the contribution and to do this it is necessary to undo 1190 * the encoding, scale the color values, perform the composition and reencode 1191 * the values. This is the 'PNG' mode. 1192 * 1193 * The alternative is to 'associate' the alpha with the color information by 1194 * storing color channel values that have been scaled by the alpha. The 1195 * advantage is that the color channels can be resampled (the image can be 1196 * scaled) in this form. The disadvantage is that normal practice is to store 1197 * linear, not (gamma) encoded, values and this requires 16-bit channels for 1198 * still images rather than the 8-bit channels that are just about sufficient if 1199 * gamma encoding is used. In addition all non-transparent pixel values, 1200 * including completely opaque ones, must be gamma encoded to produce the final 1201 * image. This is the 'STANDARD', 'ASSOCIATED' or 'PREMULTIPLIED' mode (the 1202 * latter being the two common names for associated alpha color channels.) 1203 * 1204 * Since it is not necessary to perform arithmetic on opaque color values so 1205 * long as they are not to be resampled and are in the final color space it is 1206 * possible to optimize the handling of alpha by storing the opaque pixels in 1207 * the PNG format (adjusted for the output color space) while storing partially 1208 * opaque pixels in the standard, linear, format. The accuracy required for 1209 * standard alpha composition is relatively low, because the pixels are 1210 * isolated, therefore typically the accuracy loss in storing 8-bit linear 1211 * values is acceptable. (This is not true if the alpha channel is used to 1212 * simulate transparency over large areas - use 16 bits or the PNG mode in 1213 * this case!) This is the 'OPTIMIZED' mode. For this mode a pixel is 1214 * treated as opaque only if the alpha value is equal to the maximum value. 1215 * 1216 * The final choice is to gamma encode the alpha channel as well. This is 1217 * broken because, in practice, no implementation that uses this choice 1218 * correctly undoes the encoding before handling alpha composition. Use this 1219 * choice only if other serious errors in the software or hardware you use 1220 * mandate it; the typical serious error is for dark halos to appear around 1221 * opaque areas of the composited PNG image because of arithmetic overflow. 1222 * 1223 * The API function png_set_alpha_mode specifies which of these choices to use 1224 * with an enumerated 'mode' value and the gamma of the required output: 1225 */ 1226 #define PNG_ALPHA_PNG 0 /* according to the PNG standard */ 1227 #define PNG_ALPHA_STANDARD 1 /* according to Porter/Duff */ 1228 #define PNG_ALPHA_ASSOCIATED 1 /* as above; this is the normal practice */ 1229 #define PNG_ALPHA_PREMULTIPLIED 1 /* as above */ 1230 #define PNG_ALPHA_OPTIMIZED 2 /* 'PNG' for opaque pixels, else 'STANDARD' */ 1231 #define PNG_ALPHA_BROKEN 3 /* the alpha channel is gamma encoded */ 1232 1233 PNG_FP_EXPORT(227, void, png_set_alpha_mode, (png_structp png_ptr, int mode, 1234 double output_gamma)) 1235 PNG_FIXED_EXPORT(228, void, png_set_alpha_mode_fixed, (png_structp png_ptr, 1236 int mode, png_fixed_point output_gamma)) 1237 #endif 1238 1239 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_ALPHA_MODE_SUPPORTED) 1240 /* The output_gamma value is a screen gamma in libpng terminology: it expresses 1241 * how to decode the output values, not how they are encoded. The values used 1242 * correspond to the normal numbers used to describe the overall gamma of a 1243 * computer display system; for example 2.2 for an sRGB conformant system. The 1244 * values are scaled by 100000 in the _fixed version of the API (so 220000 for 1245 * sRGB.) 1246 * 1247 * The inverse of the value is always used to provide a default for the PNG file 1248 * encoding if it has no gAMA chunk and if png_set_gamma() has not been called 1249 * to override the PNG gamma information. 1250 * 1251 * When the ALPHA_OPTIMIZED mode is selected the output gamma is used to encode 1252 * opaque pixels however pixels with lower alpha values are not encoded, 1253 * regardless of the output gamma setting. 1254 * 1255 * When the standard Porter Duff handling is requested with mode 1 the output 1256 * encoding is set to be linear and the output_gamma value is only relevant 1257 * as a default for input data that has no gamma information. The linear output 1258 * encoding will be overridden if png_set_gamma() is called - the results may be 1259 * highly unexpected! 1260 * 1261 * The following numbers are derived from the sRGB standard and the research 1262 * behind it. sRGB is defined to be approximated by a PNG gAMA chunk value of 1263 * 0.45455 (1/2.2) for PNG. The value implicitly includes any viewing 1264 * correction required to take account of any differences in the color 1265 * environment of the original scene and the intended display environment; the 1266 * value expresses how to *decode* the image for display, not how the original 1267 * data was *encoded*. 1268 * 1269 * sRGB provides a peg for the PNG standard by defining a viewing environment. 1270 * sRGB itself, and earlier TV standards, actually use a more complex transform 1271 * (a linear portion then a gamma 2.4 power law) than PNG can express. (PNG is 1272 * limited to simple power laws.) By saying that an image for direct display on 1273 * an sRGB conformant system should be stored with a gAMA chunk value of 45455 1274 * (11.3.3.2 and 11.3.3.5 of the ISO PNG specification) the PNG specification 1275 * makes it possible to derive values for other display systems and 1276 * environments. 1277 * 1278 * The Mac value is deduced from the sRGB based on an assumption that the actual 1279 * extra viewing correction used in early Mac display systems was implemented as 1280 * a power 1.45 lookup table. 1281 * 1282 * Any system where a programmable lookup table is used or where the behavior of 1283 * the final display device characteristics can be changed requires system 1284 * specific code to obtain the current characteristic. However this can be 1285 * difficult and most PNG gamma correction only requires an approximate value. 1286 * 1287 * By default, if png_set_alpha_mode() is not called, libpng assumes that all 1288 * values are unencoded, linear, values and that the output device also has a 1289 * linear characteristic. This is only very rarely correct - it is invariably 1290 * better to call png_set_alpha_mode() with PNG_DEFAULT_sRGB than rely on the 1291 * default if you don't know what the right answer is! 1292 * 1293 * The special value PNG_GAMMA_MAC_18 indicates an older Mac system (pre Mac OS 1294 * 10.6) which used a correction table to implement a somewhat lower gamma on an 1295 * otherwise sRGB system. 1296 * 1297 * Both these values are reserved (not simple gamma values) in order to allow 1298 * more precise correction internally in the future. 1299 * 1300 * NOTE: the following values can be passed to either the fixed or floating 1301 * point APIs, but the floating point API will also accept floating point 1302 * values. 1303 */ 1304 #define PNG_DEFAULT_sRGB -1 /* sRGB gamma and color space */ 1305 #define PNG_GAMMA_MAC_18 -2 /* Old Mac '1.8' gamma and color space */ 1306 #define PNG_GAMMA_sRGB 220000 /* Television standards--matches sRGB gamma */ 1307 #define PNG_GAMMA_LINEAR PNG_FP_1 /* Linear */ 1308 #endif 1309 1310 /* The following are examples of calls to png_set_alpha_mode to achieve the 1311 * required overall gamma correction and, where necessary, alpha 1312 * premultiplication. 1313 * 1314 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB); 1315 * This is the default libpng handling of the alpha channel - it is not 1316 * pre-multiplied into the color components. In addition the call states 1317 * that the output is for a sRGB system and causes all PNG files without gAMA 1318 * chunks to be assumed to be encoded using sRGB. 1319 * 1320 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC); 1321 * In this case the output is assumed to be something like an sRGB conformant 1322 * display preceeded by a power-law lookup table of power 1.45. This is how 1323 * early Mac systems behaved. 1324 * 1325 * png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_GAMMA_LINEAR); 1326 * This is the classic Jim Blinn approach and will work in academic 1327 * environments where everything is done by the book. It has the shortcoming 1328 * of assuming that input PNG data with no gamma information is linear - this 1329 * is unlikely to be correct unless the PNG files where generated locally. 1330 * Most of the time the output precision will be so low as to show 1331 * significant banding in dark areas of the image. 1332 * 1333 * png_set_expand_16(pp); 1334 * png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_DEFAULT_sRGB); 1335 * This is a somewhat more realistic Jim Blinn inspired approach. PNG files 1336 * are assumed to have the sRGB encoding if not marked with a gamma value and 1337 * the output is always 16 bits per component. This permits accurate scaling 1338 * and processing of the data. If you know that your input PNG files were 1339 * generated locally you might need to replace PNG_DEFAULT_sRGB with the 1340 * correct value for your system. 1341 * 1342 * png_set_alpha_mode(pp, PNG_ALPHA_OPTIMIZED, PNG_DEFAULT_sRGB); 1343 * If you just need to composite the PNG image onto an existing background 1344 * and if you control the code that does this you can use the optimization 1345 * setting. In this case you just copy completely opaque pixels to the 1346 * output. For pixels that are not completely transparent (you just skip 1347 * those) you do the composition math using png_composite or png_composite_16 1348 * below then encode the resultant 8-bit or 16-bit values to match the output 1349 * encoding. 1350 * 1351 * Other cases 1352 * If neither the PNG nor the standard linear encoding work for you because 1353 * of the software or hardware you use then you have a big problem. The PNG 1354 * case will probably result in halos around the image. The linear encoding 1355 * will probably result in a washed out, too bright, image (it's actually too 1356 * contrasty.) Try the ALPHA_OPTIMIZED mode above - this will probably 1357 * substantially reduce the halos. Alternatively try: 1358 * 1359 * png_set_alpha_mode(pp, PNG_ALPHA_BROKEN, PNG_DEFAULT_sRGB); 1360 * This option will also reduce the halos, but there will be slight dark 1361 * halos round the opaque parts of the image where the background is light. 1362 * In the OPTIMIZED mode the halos will be light halos where the background 1363 * is dark. Take your pick - the halos are unavoidable unless you can get 1364 * your hardware/software fixed! (The OPTIMIZED approach is slightly 1365 * faster.) 1366 * 1367 * When the default gamma of PNG files doesn't match the output gamma. 1368 * If you have PNG files with no gamma information png_set_alpha_mode allows 1369 * you to provide a default gamma, but it also sets the ouput gamma to the 1370 * matching value. If you know your PNG files have a gamma that doesn't 1371 * match the output you can take advantage of the fact that 1372 * png_set_alpha_mode always sets the output gamma but only sets the PNG 1373 * default if it is not already set: 1374 * 1375 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB); 1376 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC); 1377 * The first call sets both the default and the output gamma values, the 1378 * second call overrides the output gamma without changing the default. This 1379 * is easier than achieving the same effect with png_set_gamma. You must use 1380 * PNG_ALPHA_PNG for the first call - internal checking in png_set_alpha will 1381 * fire if more than one call to png_set_alpha_mode and png_set_background is 1382 * made in the same read operation, however multiple calls with PNG_ALPHA_PNG 1383 * are ignored. 1384 */ 1385 1386 #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED 1387 PNG_EXPORT(36, void, png_set_strip_alpha, (png_structp png_ptr)); 1388 #endif 1389 1390 #if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \ 1391 defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED) 1392 PNG_EXPORT(37, void, png_set_swap_alpha, (png_structp png_ptr)); 1393 #endif 1394 1395 #if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \ 1396 defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED) 1397 PNG_EXPORT(38, void, png_set_invert_alpha, (png_structp png_ptr)); 1398 #endif 1399 1400 #if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED) 1401 /* Add a filler byte to 8-bit Gray or 24-bit RGB images. */ 1402 PNG_EXPORT(39, void, png_set_filler, (png_structp png_ptr, png_uint_32 filler, 1403 int flags)); 1404 /* The values of the PNG_FILLER_ defines should NOT be changed */ 1405 # define PNG_FILLER_BEFORE 0 1406 # define PNG_FILLER_AFTER 1 1407 /* Add an alpha byte to 8-bit Gray or 24-bit RGB images. */ 1408 PNG_EXPORT(40, void, png_set_add_alpha, 1409 (png_structp png_ptr, png_uint_32 filler, 1410 int flags)); 1411 #endif /* PNG_READ_FILLER_SUPPORTED || PNG_WRITE_FILLER_SUPPORTED */ 1412 1413 #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED) 1414 /* Swap bytes in 16-bit depth files. */ 1415 PNG_EXPORT(41, void, png_set_swap, (png_structp png_ptr)); 1416 #endif 1417 1418 #if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED) 1419 /* Use 1 byte per pixel in 1, 2, or 4-bit depth files. */ 1420 PNG_EXPORT(42, void, png_set_packing, (png_structp png_ptr)); 1421 #endif 1422 1423 #if defined(PNG_READ_PACKSWAP_SUPPORTED) || \ 1424 defined(PNG_WRITE_PACKSWAP_SUPPORTED) 1425 /* Swap packing order of pixels in bytes. */ 1426 PNG_EXPORT(43, void, png_set_packswap, (png_structp png_ptr)); 1427 #endif 1428 1429 #if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED) 1430 /* Converts files to legal bit depths. */ 1431 PNG_EXPORT(44, void, png_set_shift, (png_structp png_ptr, png_const_color_8p 1432 true_bits)); 1433 #endif 1434 1435 #if defined(PNG_READ_INTERLACING_SUPPORTED) || \ 1436 defined(PNG_WRITE_INTERLACING_SUPPORTED) 1437 /* Have the code handle the interlacing. Returns the number of passes. 1438 * MUST be called before png_read_update_info or png_start_read_image, 1439 * otherwise it will not have the desired effect. Note that it is still 1440 * necessary to call png_read_row or png_read_rows png_get_image_height 1441 * times for each pass. 1442 */ 1443 PNG_EXPORT(45, int, png_set_interlace_handling, (png_structp png_ptr)); 1444 #endif 1445 1446 #if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED) 1447 /* Invert monochrome files */ 1448 PNG_EXPORT(46, void, png_set_invert_mono, (png_structp png_ptr)); 1449 #endif 1450 1451 #ifdef PNG_READ_BACKGROUND_SUPPORTED 1452 /* Handle alpha and tRNS by replacing with a background color. Prior to 1453 * libpng-1.5.4 this API must not be called before the PNG file header has been 1454 * read. Doing so will result in unexpected behavior and possible warnings or 1455 * errors if the PNG file contains a bKGD chunk. 1456 */ 1457 PNG_FP_EXPORT(47, void, png_set_background, (png_structp png_ptr, 1458 png_const_color_16p background_color, int background_gamma_code, 1459 int need_expand, double background_gamma)) 1460 PNG_FIXED_EXPORT(215, void, png_set_background_fixed, (png_structp png_ptr, 1461 png_const_color_16p background_color, int background_gamma_code, 1462 int need_expand, png_fixed_point background_gamma)) 1463 #endif 1464 #ifdef PNG_READ_BACKGROUND_SUPPORTED 1465 # define PNG_BACKGROUND_GAMMA_UNKNOWN 0 1466 # define PNG_BACKGROUND_GAMMA_SCREEN 1 1467 # define PNG_BACKGROUND_GAMMA_FILE 2 1468 # define PNG_BACKGROUND_GAMMA_UNIQUE 3 1469 #endif 1470 1471 #ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED 1472 /* Scale a 16-bit depth file down to 8-bit, accurately. */ 1473 PNG_EXPORT(229, void, png_set_scale_16, (png_structp png_ptr)); 1474 #endif 1475 1476 #ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED 1477 #define PNG_READ_16_TO_8 SUPPORTED /* Name prior to 1.5.4 */ 1478 /* Strip the second byte of information from a 16-bit depth file. */ 1479 PNG_EXPORT(48, void, png_set_strip_16, (png_structp png_ptr)); 1480 #endif 1481 1482 #ifdef PNG_READ_QUANTIZE_SUPPORTED 1483 /* Turn on quantizing, and reduce the palette to the number of colors 1484 * available. 1485 */ 1486 PNG_EXPORT(49, void, png_set_quantize, 1487 (png_structp png_ptr, png_colorp palette, 1488 int num_palette, int maximum_colors, png_const_uint_16p histogram, 1489 int full_quantize)); 1490 #endif 1491 1492 #ifdef PNG_READ_GAMMA_SUPPORTED 1493 /* The threshold on gamma processing is configurable but hard-wired into the 1494 * library. The following is the floating point variant. 1495 */ 1496 #define PNG_GAMMA_THRESHOLD (PNG_GAMMA_THRESHOLD_FIXED*.00001) 1497 1498 /* Handle gamma correction. Screen_gamma=(display_exponent). 1499 * NOTE: this API simply sets the screen and file gamma values. It will 1500 * therefore override the value for gamma in a PNG file if it is called after 1501 * the file header has been read - use with care - call before reading the PNG 1502 * file for best results! 1503 * 1504 * These routines accept the same gamma values as png_set_alpha_mode (described 1505 * above). The PNG_GAMMA_ defines and PNG_DEFAULT_sRGB can be passed to either 1506 * API (floating point or fixed.) Notice, however, that the 'file_gamma' value 1507 * is the inverse of a 'screen gamma' value. 1508 */ 1509 PNG_FP_EXPORT(50, void, png_set_gamma, 1510 (png_structp png_ptr, double screen_gamma, 1511 double override_file_gamma)) 1512 PNG_FIXED_EXPORT(208, void, png_set_gamma_fixed, (png_structp png_ptr, 1513 png_fixed_point screen_gamma, png_fixed_point override_file_gamma)) 1514 #endif 1515 1516 #ifdef PNG_WRITE_FLUSH_SUPPORTED 1517 /* Set how many lines between output flushes - 0 for no flushing */ 1518 PNG_EXPORT(51, void, png_set_flush, (png_structp png_ptr, int nrows)); 1519 /* Flush the current PNG output buffer */ 1520 PNG_EXPORT(52, void, png_write_flush, (png_structp png_ptr)); 1521 #endif 1522 1523 /* Optional update palette with requested transformations */ 1524 PNG_EXPORT(53, void, png_start_read_image, (png_structp png_ptr)); 1525 1526 /* Optional call to update the users info structure */ 1527 PNG_EXPORT(54, void, png_read_update_info, 1528 (png_structp png_ptr, png_infop info_ptr)); 1529 1530 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED 1531 /* Read one or more rows of image data. */ 1532 PNG_EXPORT(55, void, png_read_rows, (png_structp png_ptr, png_bytepp row, 1533 png_bytepp display_row, png_uint_32 num_rows)); 1534 #endif 1535 1536 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED 1537 /* Read a row of data. */ 1538 PNG_EXPORT(56, void, png_read_row, (png_structp png_ptr, png_bytep row, 1539 png_bytep display_row)); 1540 #endif 1541 1542 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED 1543 /* Read the whole image into memory at once. */ 1544 PNG_EXPORT(57, void, png_read_image, (png_structp png_ptr, png_bytepp image)); 1545 #endif 1546 1547 /* Write a row of image data */ 1548 PNG_EXPORT(58, void, png_write_row, 1549 (png_structp png_ptr, png_const_bytep row)); 1550 1551 /* Write a few rows of image data: (*row) is not written; however, the type 1552 * is declared as writeable to maintain compatibility with previous versions 1553 * of libpng and to allow the 'display_row' array from read_rows to be passed 1554 * unchanged to write_rows. 1555 */ 1556 PNG_EXPORT(59, void, png_write_rows, (png_structp png_ptr, png_bytepp row, 1557 png_uint_32 num_rows)); 1558 1559 /* Write the image data */ 1560 PNG_EXPORT(60, void, png_write_image, 1561 (png_structp png_ptr, png_bytepp image)); 1562 1563 /* Write the end of the PNG file. */ 1564 PNG_EXPORT(61, void, png_write_end, 1565 (png_structp png_ptr, png_infop info_ptr)); 1566 1567 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED 1568 /* Read the end of the PNG file. */ 1569 PNG_EXPORT(62, void, png_read_end, (png_structp png_ptr, png_infop info_ptr)); 1570 #endif 1571 1572 /* Free any memory associated with the png_info_struct */ 1573 PNG_EXPORT(63, void, png_destroy_info_struct, (png_structp png_ptr, 1574 png_infopp info_ptr_ptr)); 1575 1576 /* Free any memory associated with the png_struct and the png_info_structs */ 1577 PNG_EXPORT(64, void, png_destroy_read_struct, (png_structpp png_ptr_ptr, 1578 png_infopp info_ptr_ptr, png_infopp end_info_ptr_ptr)); 1579 1580 /* Free any memory associated with the png_struct and the png_info_structs */ 1581 PNG_EXPORT(65, void, png_destroy_write_struct, (png_structpp png_ptr_ptr, 1582 png_infopp info_ptr_ptr)); 1583 1584 /* Set the libpng method of handling chunk CRC errors */ 1585 PNG_EXPORT(66, void, png_set_crc_action, 1586 (png_structp png_ptr, int crit_action, int ancil_action)); 1587 1588 /* Values for png_set_crc_action() say how to handle CRC errors in 1589 * ancillary and critical chunks, and whether to use the data contained 1590 * therein. Note that it is impossible to "discard" data in a critical 1591 * chunk. For versions prior to 0.90, the action was always error/quit, 1592 * whereas in version 0.90 and later, the action for CRC errors in ancillary 1593 * chunks is warn/discard. These values should NOT be changed. 1594 * 1595 * value action:critical action:ancillary 1596 */ 1597 #define PNG_CRC_DEFAULT 0 /* error/quit warn/discard data */ 1598 #define PNG_CRC_ERROR_QUIT 1 /* error/quit error/quit */ 1599 #define PNG_CRC_WARN_DISCARD 2 /* (INVALID) warn/discard data */ 1600 #define PNG_CRC_WARN_USE 3 /* warn/use data warn/use data */ 1601 #define PNG_CRC_QUIET_USE 4 /* quiet/use data quiet/use data */ 1602 #define PNG_CRC_NO_CHANGE 5 /* use current value use current value */ 1603 1604 /* These functions give the user control over the scan-line filtering in 1605 * libpng and the compression methods used by zlib. These functions are 1606 * mainly useful for testing, as the defaults should work with most users. 1607 * Those users who are tight on memory or want faster performance at the 1608 * expense of compression can modify them. See the compression library 1609 * header file (zlib.h) for an explination of the compression functions. 1610 */ 1611 1612 /* Set the filtering method(s) used by libpng. Currently, the only valid 1613 * value for "method" is 0. 1614 */ 1615 PNG_EXPORT(67, void, png_set_filter, 1616 (png_structp png_ptr, int method, int filters)); 1617 1618 /* Flags for png_set_filter() to say which filters to use. The flags 1619 * are chosen so that they don't conflict with real filter types 1620 * below, in case they are supplied instead of the #defined constants. 1621 * These values should NOT be changed. 1622 */ 1623 #define PNG_NO_FILTERS 0x00 1624 #define PNG_FILTER_NONE 0x08 1625 #define PNG_FILTER_SUB 0x10 1626 #define PNG_FILTER_UP 0x20 1627 #define PNG_FILTER_AVG 0x40 1628 #define PNG_FILTER_PAETH 0x80 1629 #define PNG_ALL_FILTERS (PNG_FILTER_NONE | PNG_FILTER_SUB | PNG_FILTER_UP | \ 1630 PNG_FILTER_AVG | PNG_FILTER_PAETH) 1631 1632 /* Filter values (not flags) - used in pngwrite.c, pngwutil.c for now. 1633 * These defines should NOT be changed. 1634 */ 1635 #define PNG_FILTER_VALUE_NONE 0 1636 #define PNG_FILTER_VALUE_SUB 1 1637 #define PNG_FILTER_VALUE_UP 2 1638 #define PNG_FILTER_VALUE_AVG 3 1639 #define PNG_FILTER_VALUE_PAETH 4 1640 #define PNG_FILTER_VALUE_LAST 5 1641 1642 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* EXPERIMENTAL */ 1643 /* The "heuristic_method" is given by one of the PNG_FILTER_HEURISTIC_ 1644 * defines, either the default (minimum-sum-of-absolute-differences), or 1645 * the experimental method (weighted-minimum-sum-of-absolute-differences). 1646 * 1647 * Weights are factors >= 1.0, indicating how important it is to keep the 1648 * filter type consistent between rows. Larger numbers mean the current 1649 * filter is that many times as likely to be the same as the "num_weights" 1650 * previous filters. This is cumulative for each previous row with a weight. 1651 * There needs to be "num_weights" values in "filter_weights", or it can be 1652 * NULL if the weights aren't being specified. Weights have no influence on 1653 * the selection of the first row filter. Well chosen weights can (in theory) 1654 * improve the compression for a given image. 1655 * 1656 * Costs are factors >= 1.0 indicating the relative decoding costs of a 1657 * filter type. Higher costs indicate more decoding expense, and are 1658 * therefore less likely to be selected over a filter with lower computational 1659 * costs. There needs to be a value in "filter_costs" for each valid filter 1660 * type (given by PNG_FILTER_VALUE_LAST), or it can be NULL if you aren't 1661 * setting the costs. Costs try to improve the speed of decompression without 1662 * unduly increasing the compressed image size. 1663 * 1664 * A negative weight or cost indicates the default value is to be used, and 1665 * values in the range [0.0, 1.0) indicate the value is to remain unchanged. 1666 * The default values for both weights and costs are currently 1.0, but may 1667 * change if good general weighting/cost heuristics can be found. If both 1668 * the weights and costs are set to 1.0, this degenerates the WEIGHTED method 1669 * to the UNWEIGHTED method, but with added encoding time/computation. 1670 */ 1671 PNG_FP_EXPORT(68, void, png_set_filter_heuristics, (png_structp png_ptr, 1672 int heuristic_method, int num_weights, png_const_doublep filter_weights, 1673 png_const_doublep filter_costs)) 1674 PNG_FIXED_EXPORT(209, void, png_set_filter_heuristics_fixed, 1675 (png_structp png_ptr, 1676 int heuristic_method, int num_weights, png_const_fixed_point_p 1677 filter_weights, png_const_fixed_point_p filter_costs)) 1678 #endif /* PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */ 1679 1680 /* Heuristic used for row filter selection. These defines should NOT be 1681 * changed. 1682 */ 1683 #define PNG_FILTER_HEURISTIC_DEFAULT 0 /* Currently "UNWEIGHTED" */ 1684 #define PNG_FILTER_HEURISTIC_UNWEIGHTED 1 /* Used by libpng < 0.95 */ 1685 #define PNG_FILTER_HEURISTIC_WEIGHTED 2 /* Experimental feature */ 1686 #define PNG_FILTER_HEURISTIC_LAST 3 /* Not a valid value */ 1687 1688 #ifdef PNG_WRITE_SUPPORTED 1689 /* Set the library compression level. Currently, valid values range from 1690 * 0 - 9, corresponding directly to the zlib compression levels 0 - 9 1691 * (0 - no compression, 9 - "maximal" compression). Note that tests have 1692 * shown that zlib compression levels 3-6 usually perform as well as level 9 1693 * for PNG images, and do considerably fewer caclulations. In the future, 1694 * these values may not correspond directly to the zlib compression levels. 1695 */ 1696 PNG_EXPORT(69, void, png_set_compression_level, 1697 (png_structp png_ptr, int level)); 1698 1699 PNG_EXPORT(70, void, png_set_compression_mem_level, (png_structp png_ptr, 1700 int mem_level)); 1701 1702 PNG_EXPORT(71, void, png_set_compression_strategy, (png_structp png_ptr, 1703 int strategy)); 1704 1705 /* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a 1706 * smaller value of window_bits if it can do so safely. 1707 */ 1708 PNG_EXPORT(72, void, png_set_compression_window_bits, (png_structp png_ptr, 1709 int window_bits)); 1710 1711 PNG_EXPORT(73, void, png_set_compression_method, (png_structp png_ptr, 1712 int method)); 1713 #endif 1714 1715 #ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED 1716 /* Also set zlib parameters for compressing non-IDAT chunks */ 1717 PNG_EXPORT(222, void, png_set_text_compression_level, 1718 (png_structp png_ptr, int level)); 1719 1720 PNG_EXPORT(223, void, png_set_text_compression_mem_level, (png_structp png_ptr, 1721 int mem_level)); 1722 1723 PNG_EXPORT(224, void, png_set_text_compression_strategy, (png_structp png_ptr, 1724 int strategy)); 1725 1726 /* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a 1727 * smaller value of window_bits if it can do so safely. 1728 */ 1729 PNG_EXPORT(225, void, png_set_text_compression_window_bits, (png_structp 1730 png_ptr, int window_bits)); 1731 1732 PNG_EXPORT(226, void, png_set_text_compression_method, (png_structp png_ptr, 1733 int method)); 1734 #endif /* PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED */ 1735 1736 /* These next functions are called for input/output, memory, and error 1737 * handling. They are in the file pngrio.c, pngwio.c, and pngerror.c, 1738 * and call standard C I/O routines such as fread(), fwrite(), and 1739 * fprintf(). These functions can be made to use other I/O routines 1740 * at run time for those applications that need to handle I/O in a 1741 * different manner by calling png_set_???_fn(). See libpng-manual.txt for 1742 * more information. 1743 */ 1744 1745 #ifdef PNG_STDIO_SUPPORTED 1746 /* Initialize the input/output for the PNG file to the default functions. */ 1747 PNG_EXPORT(74, void, png_init_io, (png_structp png_ptr, png_FILE_p fp)); 1748 #endif 1749 1750 /* Replace the (error and abort), and warning functions with user 1751 * supplied functions. If no messages are to be printed you must still 1752 * write and use replacement functions. The replacement error_fn should 1753 * still do a longjmp to the last setjmp location if you are using this 1754 * method of error handling. If error_fn or warning_fn is NULL, the 1755 * default function will be used. 1756 */ 1757 1758 PNG_EXPORT(75, void, png_set_error_fn, 1759 (png_structp png_ptr, png_voidp error_ptr, 1760 png_error_ptr error_fn, png_error_ptr warning_fn)); 1761 1762 /* Return the user pointer associated with the error functions */ 1763 PNG_EXPORT(76, png_voidp, png_get_error_ptr, (png_const_structp png_ptr)); 1764 1765 /* Replace the default data output functions with a user supplied one(s). 1766 * If buffered output is not used, then output_flush_fn can be set to NULL. 1767 * If PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile time 1768 * output_flush_fn will be ignored (and thus can be NULL). 1769 * It is probably a mistake to use NULL for output_flush_fn if 1770 * write_data_fn is not also NULL unless you have built libpng with 1771 * PNG_WRITE_FLUSH_SUPPORTED undefined, because in this case libpng's 1772 * default flush function, which uses the standard *FILE structure, will 1773 * be used. 1774 */ 1775 PNG_EXPORT(77, void, png_set_write_fn, (png_structp png_ptr, png_voidp io_ptr, 1776 png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn)); 1777 1778 /* Replace the default data input function with a user supplied one. */ 1779 PNG_EXPORT(78, void, png_set_read_fn, (png_structp png_ptr, png_voidp io_ptr, 1780 png_rw_ptr read_data_fn)); 1781 1782 /* Return the user pointer associated with the I/O functions */ 1783 PNG_EXPORT(79, png_voidp, png_get_io_ptr, (png_structp png_ptr)); 1784 1785 PNG_EXPORT(80, void, png_set_read_status_fn, (png_structp png_ptr, 1786 png_read_status_ptr read_row_fn)); 1787 1788 PNG_EXPORT(81, void, png_set_write_status_fn, (png_structp png_ptr, 1789 png_write_status_ptr write_row_fn)); 1790 1791 #ifdef PNG_USER_MEM_SUPPORTED 1792 /* Replace the default memory allocation functions with user supplied one(s). */ 1793 PNG_EXPORT(82, void, png_set_mem_fn, (png_structp png_ptr, png_voidp mem_ptr, 1794 png_malloc_ptr malloc_fn, png_free_ptr free_fn)); 1795 /* Return the user pointer associated with the memory functions */ 1796 PNG_EXPORT(83, png_voidp, png_get_mem_ptr, (png_const_structp png_ptr)); 1797 #endif 1798 1799 #ifdef PNG_READ_USER_TRANSFORM_SUPPORTED 1800 PNG_EXPORT(84, void, png_set_read_user_transform_fn, (png_structp png_ptr, 1801 png_user_transform_ptr read_user_transform_fn)); 1802 #endif 1803 1804 #ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED 1805 PNG_EXPORT(85, void, png_set_write_user_transform_fn, (png_structp png_ptr, 1806 png_user_transform_ptr write_user_transform_fn)); 1807 #endif 1808 1809 #ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED 1810 PNG_EXPORT(86, void, png_set_user_transform_info, (png_structp png_ptr, 1811 png_voidp user_transform_ptr, int user_transform_depth, 1812 int user_transform_channels)); 1813 /* Return the user pointer associated with the user transform functions */ 1814 PNG_EXPORT(87, png_voidp, png_get_user_transform_ptr, 1815 (png_const_structp png_ptr)); 1816 #endif 1817 1818 #ifdef PNG_USER_TRANSFORM_INFO_SUPPORTED 1819 /* Return information about the row currently being processed. Note that these 1820 * APIs do not fail but will return unexpected results if called outside a user 1821 * transform callback. Also note that when transforming an interlaced image the 1822 * row number is the row number within the sub-image of the interlace pass, so 1823 * the value will increase to the height of the sub-image (not the full image) 1824 * then reset to 0 for the next pass. 1825 * 1826 * Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to 1827 * find the output pixel (x,y) given an interlaced sub-image pixel 1828 * (row,col,pass). (See below for these macros.) 1829 */ 1830 PNG_EXPORT(217, png_uint_32, png_get_current_row_number, (png_const_structp)); 1831 PNG_EXPORT(218, png_byte, png_get_current_pass_number, (png_const_structp)); 1832 #endif 1833 1834 #ifdef PNG_USER_CHUNKS_SUPPORTED 1835 PNG_EXPORT(88, void, png_set_read_user_chunk_fn, (png_structp png_ptr, 1836 png_voidp user_chunk_ptr, png_user_chunk_ptr read_user_chunk_fn)); 1837 PNG_EXPORT(89, png_voidp, png_get_user_chunk_ptr, (png_const_structp png_ptr)); 1838 #endif 1839 1840 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED 1841 /* Sets the function callbacks for the push reader, and a pointer to a 1842 * user-defined structure available to the callback functions. 1843 */ 1844 PNG_EXPORT(90, void, png_set_progressive_read_fn, (png_structp png_ptr, 1845 png_voidp progressive_ptr, png_progressive_info_ptr info_fn, 1846 png_progressive_row_ptr row_fn, png_progressive_end_ptr end_fn)); 1847 1848 /* Returns the user pointer associated with the push read functions */ 1849 PNG_EXPORT(91, png_voidp, png_get_progressive_ptr, (png_const_structp png_ptr)); 1850 1851 /* Function to be called when data becomes available */ 1852 PNG_EXPORT(92, void, png_process_data, 1853 (png_structp png_ptr, png_infop info_ptr, 1854 png_bytep buffer, png_size_t buffer_size)); 1855 1856 /* A function which may be called *only* within png_process_data to stop the 1857 * processing of any more data. The function returns the number of bytes 1858 * remaining, excluding any that libpng has cached internally. A subsequent 1859 * call to png_process_data must supply these bytes again. If the argument 1860 * 'save' is set to true the routine will first save all the pending data and 1861 * will always return 0. 1862 */ 1863 PNG_EXPORT(219, png_size_t, png_process_data_pause, (png_structp, int save)); 1864 1865 /* A function which may be called *only* outside (after) a call to 1866 * png_process_data. It returns the number of bytes of data to skip in the 1867 * input. Normally it will return 0, but if it returns a non-zero value the 1868 * application must skip than number of bytes of input data and pass the 1869 * following data to the next call to png_process_data. 1870 */ 1871 PNG_EXPORT(220, png_uint_32, png_process_data_skip, (png_structp)); 1872 1873 #ifdef PNG_READ_INTERLACING_SUPPORTED 1874 /* Function that combines rows. 'new_row' is a flag that should come from 1875 * the callback and be non-NULL if anything needs to be done; the library 1876 * stores its own version of the new data internally and ignores the passed 1877 * in value. 1878 */ 1879 PNG_EXPORT(93, void, png_progressive_combine_row, (png_structp png_ptr, 1880 png_bytep old_row, png_const_bytep new_row)); 1881 #endif /* PNG_READ_INTERLACING_SUPPORTED */ 1882 #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */ 1883 1884 PNG_EXPORTA(94, png_voidp, png_malloc, 1885 (png_structp png_ptr, png_alloc_size_t size), 1886 PNG_ALLOCATED); 1887 /* Added at libpng version 1.4.0 */ 1888 PNG_EXPORTA(95, png_voidp, png_calloc, 1889 (png_structp png_ptr, png_alloc_size_t size), 1890 PNG_ALLOCATED); 1891 1892 /* Added at libpng version 1.2.4 */ 1893 PNG_EXPORTA(96, png_voidp, png_malloc_warn, (png_structp png_ptr, 1894 png_alloc_size_t size), PNG_ALLOCATED); 1895 1896 /* Frees a pointer allocated by png_malloc() */ 1897 PNG_EXPORT(97, void, png_free, (png_structp png_ptr, png_voidp ptr)); 1898 1899 /* Free data that was allocated internally */ 1900 PNG_EXPORT(98, void, png_free_data, 1901 (png_structp png_ptr, png_infop info_ptr, png_uint_32 free_me, int num)); 1902 1903 /* Reassign responsibility for freeing existing data, whether allocated 1904 * by libpng or by the application */ 1905 PNG_EXPORT(99, void, png_data_freer, 1906 (png_structp png_ptr, png_infop info_ptr, int freer, png_uint_32 mask)); 1907 1908 /* Assignments for png_data_freer */ 1909 #define PNG_DESTROY_WILL_FREE_DATA 1 1910 #define PNG_SET_WILL_FREE_DATA 1 1911 #define PNG_USER_WILL_FREE_DATA 2 1912 /* Flags for png_ptr->free_me and info_ptr->free_me */ 1913 #define PNG_FREE_HIST 0x0008 1914 #define PNG_FREE_ICCP 0x0010 1915 #define PNG_FREE_SPLT 0x0020 1916 #define PNG_FREE_ROWS 0x0040 1917 #define PNG_FREE_PCAL 0x0080 1918 #define PNG_FREE_SCAL 0x0100 1919 #define PNG_FREE_UNKN 0x0200 1920 #define PNG_FREE_LIST 0x0400 1921 #define PNG_FREE_PLTE 0x1000 1922 #define PNG_FREE_TRNS 0x2000 1923 #define PNG_FREE_TEXT 0x4000 1924 #define PNG_FREE_ALL 0x7fff 1925 #define PNG_FREE_MUL 0x4220 /* PNG_FREE_SPLT|PNG_FREE_TEXT|PNG_FREE_UNKN */ 1926 1927 #ifdef PNG_USER_MEM_SUPPORTED 1928 PNG_EXPORTA(100, png_voidp, png_malloc_default, (png_structp png_ptr, 1929 png_alloc_size_t size), PNG_ALLOCATED); 1930 PNG_EXPORT(101, void, png_free_default, (png_structp png_ptr, png_voidp ptr)); 1931 #endif 1932 1933 #ifdef PNG_ERROR_TEXT_SUPPORTED 1934 /* Fatal error in PNG image of libpng - can't continue */ 1935 PNG_EXPORTA(102, void, png_error, 1936 (png_structp png_ptr, png_const_charp error_message), 1937 PNG_NORETURN); 1938 1939 /* The same, but the chunk name is prepended to the error string. */ 1940 PNG_EXPORTA(103, void, png_chunk_error, (png_structp png_ptr, 1941 png_const_charp error_message), PNG_NORETURN); 1942 1943 #else 1944 /* Fatal error in PNG image of libpng - can't continue */ 1945 PNG_EXPORTA(104, void, png_err, (png_structp png_ptr), PNG_NORETURN); 1946 #endif 1947 1948 #ifdef PNG_WARNINGS_SUPPORTED 1949 /* Non-fatal error in libpng. Can continue, but may have a problem. */ 1950 PNG_EXPORT(105, void, png_warning, (png_structp png_ptr, 1951 png_const_charp warning_message)); 1952 1953 /* Non-fatal error in libpng, chunk name is prepended to message. */ 1954 PNG_EXPORT(106, void, png_chunk_warning, (png_structp png_ptr, 1955 png_const_charp warning_message)); 1956 #endif 1957 1958 #ifdef PNG_BENIGN_ERRORS_SUPPORTED 1959 /* Benign error in libpng. Can continue, but may have a problem. 1960 * User can choose whether to handle as a fatal error or as a warning. */ 1961 # undef png_benign_error 1962 PNG_EXPORT(107, void, png_benign_error, (png_structp png_ptr, 1963 png_const_charp warning_message)); 1964 1965 /* Same, chunk name is prepended to message. */ 1966 # undef png_chunk_benign_error 1967 PNG_EXPORT(108, void, png_chunk_benign_error, (png_structp png_ptr, 1968 png_const_charp warning_message)); 1969 1970 PNG_EXPORT(109, void, png_set_benign_errors, 1971 (png_structp png_ptr, int allowed)); 1972 #else 1973 # ifdef PNG_ALLOW_BENIGN_ERRORS 1974 # define png_benign_error png_warning 1975 # define png_chunk_benign_error png_chunk_warning 1976 # else 1977 # define png_benign_error png_error 1978 # define png_chunk_benign_error png_chunk_error 1979 # endif 1980 #endif 1981 1982 /* The png_set_<chunk> functions are for storing values in the png_info_struct. 1983 * Similarly, the png_get_<chunk> calls are used to read values from the 1984 * png_info_struct, either storing the parameters in the passed variables, or 1985 * setting pointers into the png_info_struct where the data is stored. The 1986 * png_get_<chunk> functions return a non-zero value if the data was available 1987 * in info_ptr, or return zero and do not change any of the parameters if the 1988 * data was not available. 1989 * 1990 * These functions should be used instead of directly accessing png_info 1991 * to avoid problems with future changes in the size and internal layout of 1992 * png_info_struct. 1993 */ 1994 /* Returns "flag" if chunk data is valid in info_ptr. */ 1995 PNG_EXPORT(110, png_uint_32, png_get_valid, 1996 (png_const_structp png_ptr, png_const_infop info_ptr, 1997 png_uint_32 flag)); 1998 1999 /* Returns number of bytes needed to hold a transformed row. */ 2000 PNG_EXPORT(111, png_size_t, png_get_rowbytes, (png_const_structp png_ptr, 2001 png_const_infop info_ptr)); 2002 2003 #ifdef PNG_INFO_IMAGE_SUPPORTED 2004 /* Returns row_pointers, which is an array of pointers to scanlines that was 2005 * returned from png_read_png(). 2006 */ 2007 PNG_EXPORT(112, png_bytepp, png_get_rows, 2008 (png_const_structp png_ptr, png_const_infop info_ptr)); 2009 /* Set row_pointers, which is an array of pointers to scanlines for use 2010 * by png_write_png(). 2011 */ 2012 PNG_EXPORT(113, void, png_set_rows, (png_structp png_ptr, 2013 png_infop info_ptr, png_bytepp row_pointers)); 2014 #endif 2015 2016 /* Returns number of color channels in image. */ 2017 PNG_EXPORT(114, png_byte, png_get_channels, 2018 (png_const_structp png_ptr, png_const_infop info_ptr)); 2019 2020 #ifdef PNG_EASY_ACCESS_SUPPORTED 2021 /* Returns image width in pixels. */ 2022 PNG_EXPORT(115, png_uint_32, png_get_image_width, (png_const_structp png_ptr, 2023 png_const_infop info_ptr)); 2024 2025 /* Returns image height in pixels. */ 2026 PNG_EXPORT(116, png_uint_32, png_get_image_height, (png_const_structp png_ptr, 2027 png_const_infop info_ptr)); 2028 2029 /* Returns image bit_depth. */ 2030 PNG_EXPORT(117, png_byte, png_get_bit_depth, 2031 (png_const_structp png_ptr, png_const_infop info_ptr)); 2032 2033 /* Returns image color_type. */ 2034 PNG_EXPORT(118, png_byte, png_get_color_type, (png_const_structp png_ptr, 2035 png_const_infop info_ptr)); 2036 2037 /* Returns image filter_type. */ 2038 PNG_EXPORT(119, png_byte, png_get_filter_type, (png_const_structp png_ptr, 2039 png_const_infop info_ptr)); 2040 2041 /* Returns image interlace_type. */ 2042 PNG_EXPORT(120, png_byte, png_get_interlace_type, (png_const_structp png_ptr, 2043 png_const_infop info_ptr)); 2044 2045 /* Returns image compression_type. */ 2046 PNG_EXPORT(121, png_byte, png_get_compression_type, (png_const_structp png_ptr, 2047 png_const_infop info_ptr)); 2048 2049 /* Returns image resolution in pixels per meter, from pHYs chunk data. */ 2050 PNG_EXPORT(122, png_uint_32, png_get_pixels_per_meter, 2051 (png_const_structp png_ptr, png_const_infop info_ptr)); 2052 PNG_EXPORT(123, png_uint_32, png_get_x_pixels_per_meter, 2053 (png_const_structp png_ptr, png_const_infop info_ptr)); 2054 PNG_EXPORT(124, png_uint_32, png_get_y_pixels_per_meter, 2055 (png_const_structp png_ptr, png_const_infop info_ptr)); 2056 2057 /* Returns pixel aspect ratio, computed from pHYs chunk data. */ 2058 PNG_FP_EXPORT(125, float, png_get_pixel_aspect_ratio, 2059 (png_const_structp png_ptr, png_const_infop info_ptr)) 2060 PNG_FIXED_EXPORT(210, png_fixed_point, png_get_pixel_aspect_ratio_fixed, 2061 (png_const_structp png_ptr, png_const_infop info_ptr)) 2062 2063 /* Returns image x, y offset in pixels or microns, from oFFs chunk data. */ 2064 PNG_EXPORT(126, png_int_32, png_get_x_offset_pixels, 2065 (png_const_structp png_ptr, png_const_infop info_ptr)); 2066 PNG_EXPORT(127, png_int_32, png_get_y_offset_pixels, 2067 (png_const_structp png_ptr, png_const_infop info_ptr)); 2068 PNG_EXPORT(128, png_int_32, png_get_x_offset_microns, 2069 (png_const_structp png_ptr, png_const_infop info_ptr)); 2070 PNG_EXPORT(129, png_int_32, png_get_y_offset_microns, 2071 (png_const_structp png_ptr, png_const_infop info_ptr)); 2072 2073 #endif /* PNG_EASY_ACCESS_SUPPORTED */ 2074 2075 /* Returns pointer to signature string read from PNG header */ 2076 PNG_EXPORT(130, png_const_bytep, png_get_signature, 2077 (png_const_structp png_ptr, png_infop info_ptr)); 2078 2079 #ifdef PNG_bKGD_SUPPORTED 2080 PNG_EXPORT(131, png_uint_32, png_get_bKGD, 2081 (png_const_structp png_ptr, png_infop info_ptr, 2082 png_color_16p *background)); 2083 #endif 2084 2085 #ifdef PNG_bKGD_SUPPORTED 2086 PNG_EXPORT(132, void, png_set_bKGD, (png_structp png_ptr, png_infop info_ptr, 2087 png_const_color_16p background)); 2088 #endif 2089 2090 #ifdef PNG_cHRM_SUPPORTED 2091 PNG_FP_EXPORT(133, png_uint_32, png_get_cHRM, (png_const_structp png_ptr, 2092 png_const_infop info_ptr, double *white_x, double *white_y, double *red_x, 2093 double *red_y, double *green_x, double *green_y, double *blue_x, 2094 double *blue_y)) 2095 PNG_FP_EXPORT(230, png_uint_32, png_get_cHRM_XYZ, (png_structp png_ptr, 2096 png_const_infop info_ptr, double *red_X, double *red_Y, double *red_Z, 2097 double *green_X, double *green_Y, double *green_Z, double *blue_X, 2098 double *blue_Y, double *blue_Z)) 2099 #ifdef PNG_FIXED_POINT_SUPPORTED /* Otherwise not implemented */ 2100 PNG_FIXED_EXPORT(134, png_uint_32, png_get_cHRM_fixed, 2101 (png_const_structp png_ptr, 2102 png_const_infop info_ptr, png_fixed_point *int_white_x, 2103 png_fixed_point *int_white_y, png_fixed_point *int_red_x, 2104 png_fixed_point *int_red_y, png_fixed_point *int_green_x, 2105 png_fixed_point *int_green_y, png_fixed_point *int_blue_x, 2106 png_fixed_point *int_blue_y)) 2107 #endif 2108 PNG_FIXED_EXPORT(231, png_uint_32, png_get_cHRM_XYZ_fixed, 2109 (png_structp png_ptr, png_const_infop info_ptr, 2110 png_fixed_point *int_red_X, png_fixed_point *int_red_Y, 2111 png_fixed_point *int_red_Z, png_fixed_point *int_green_X, 2112 png_fixed_point *int_green_Y, png_fixed_point *int_green_Z, 2113 png_fixed_point *int_blue_X, png_fixed_point *int_blue_Y, 2114 png_fixed_point *int_blue_Z)) 2115 #endif 2116 2117 #ifdef PNG_cHRM_SUPPORTED 2118 PNG_FP_EXPORT(135, void, png_set_cHRM, 2119 (png_structp png_ptr, png_infop info_ptr, 2120 double white_x, double white_y, double red_x, double red_y, double green_x, 2121 double green_y, double blue_x, double blue_y)) 2122 PNG_FP_EXPORT(232, void, png_set_cHRM_XYZ, (png_structp png_ptr, 2123 png_infop info_ptr, double red_X, double red_Y, double red_Z, 2124 double green_X, double green_Y, double green_Z, double blue_X, 2125 double blue_Y, double blue_Z)) 2126 PNG_FIXED_EXPORT(136, void, png_set_cHRM_fixed, (png_structp png_ptr, 2127 png_infop info_ptr, png_fixed_point int_white_x, 2128 png_fixed_point int_white_y, png_fixed_point int_red_x, 2129 png_fixed_point int_red_y, png_fixed_point int_green_x, 2130 png_fixed_point int_green_y, png_fixed_point int_blue_x, 2131 png_fixed_point int_blue_y)) 2132 PNG_FIXED_EXPORT(233, void, png_set_cHRM_XYZ_fixed, (png_structp png_ptr, 2133 png_infop info_ptr, png_fixed_point int_red_X, png_fixed_point int_red_Y, 2134 png_fixed_point int_red_Z, png_fixed_point int_green_X, 2135 png_fixed_point int_green_Y, png_fixed_point int_green_Z, 2136 png_fixed_point int_blue_X, png_fixed_point int_blue_Y, 2137 png_fixed_point int_blue_Z)) 2138 #endif 2139 2140 #ifdef PNG_gAMA_SUPPORTED 2141 PNG_FP_EXPORT(137, png_uint_32, png_get_gAMA, 2142 (png_const_structp png_ptr, png_const_infop info_ptr, 2143 double *file_gamma)) 2144 PNG_FIXED_EXPORT(138, png_uint_32, png_get_gAMA_fixed, 2145 (png_const_structp png_ptr, png_const_infop info_ptr, 2146 png_fixed_point *int_file_gamma)) 2147 #endif 2148 2149 #ifdef PNG_gAMA_SUPPORTED 2150 PNG_FP_EXPORT(139, void, png_set_gAMA, (png_structp png_ptr, 2151 png_infop info_ptr, double file_gamma)) 2152 PNG_FIXED_EXPORT(140, void, png_set_gAMA_fixed, (png_structp png_ptr, 2153 png_infop info_ptr, png_fixed_point int_file_gamma)) 2154 #endif 2155 2156 #ifdef PNG_hIST_SUPPORTED 2157 PNG_EXPORT(141, png_uint_32, png_get_hIST, 2158 (png_const_structp png_ptr, png_const_infop info_ptr, 2159 png_uint_16p *hist)); 2160 #endif 2161 2162 #ifdef PNG_hIST_SUPPORTED 2163 PNG_EXPORT(142, void, png_set_hIST, (png_structp png_ptr, 2164 png_infop info_ptr, png_const_uint_16p hist)); 2165 #endif 2166 2167 PNG_EXPORT(143, png_uint_32, png_get_IHDR, 2168 (png_structp png_ptr, png_infop info_ptr, 2169 png_uint_32 *width, png_uint_32 *height, int *bit_depth, int *color_type, 2170 int *interlace_method, int *compression_method, int *filter_method)); 2171 2172 PNG_EXPORT(144, void, png_set_IHDR, 2173 (png_structp png_ptr, png_infop info_ptr, 2174 png_uint_32 width, png_uint_32 height, int bit_depth, int color_type, 2175 int interlace_method, int compression_method, int filter_method)); 2176 2177 #ifdef PNG_oFFs_SUPPORTED 2178 PNG_EXPORT(145, png_uint_32, png_get_oFFs, 2179 (png_const_structp png_ptr, png_const_infop info_ptr, 2180 png_int_32 *offset_x, png_int_32 *offset_y, int *unit_type)); 2181 #endif 2182 2183 #ifdef PNG_oFFs_SUPPORTED 2184 PNG_EXPORT(146, void, png_set_oFFs, 2185 (png_structp png_ptr, png_infop info_ptr, 2186 png_int_32 offset_x, png_int_32 offset_y, int unit_type)); 2187 #endif 2188 2189 #ifdef PNG_pCAL_SUPPORTED 2190 PNG_EXPORT(147, png_uint_32, png_get_pCAL, 2191 (png_const_structp png_ptr, png_const_infop info_ptr, 2192 png_charp *purpose, png_int_32 *X0, png_int_32 *X1, int *type, 2193 int *nparams, 2194 png_charp *units, png_charpp *params)); 2195 #endif 2196 2197 #ifdef PNG_pCAL_SUPPORTED 2198 PNG_EXPORT(148, void, png_set_pCAL, (png_structp png_ptr, 2199 png_infop info_ptr, 2200 png_const_charp purpose, png_int_32 X0, png_int_32 X1, int type, 2201 int nparams, png_const_charp units, png_charpp params)); 2202 #endif 2203 2204 #ifdef PNG_pHYs_SUPPORTED 2205 PNG_EXPORT(149, png_uint_32, png_get_pHYs, 2206 (png_const_structp png_ptr, png_const_infop info_ptr, 2207 png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type)); 2208 #endif 2209 2210 #ifdef PNG_pHYs_SUPPORTED 2211 PNG_EXPORT(150, void, png_set_pHYs, 2212 (png_structp png_ptr, png_infop info_ptr, 2213 png_uint_32 res_x, png_uint_32 res_y, int unit_type)); 2214 #endif 2215 2216 PNG_EXPORT(151, png_uint_32, png_get_PLTE, 2217 (png_const_structp png_ptr, png_const_infop info_ptr, 2218 png_colorp *palette, int *num_palette)); 2219 2220 PNG_EXPORT(152, void, png_set_PLTE, 2221 (png_structp png_ptr, png_infop info_ptr, 2222 png_const_colorp palette, int num_palette)); 2223 2224 #ifdef PNG_sBIT_SUPPORTED 2225 PNG_EXPORT(153, png_uint_32, png_get_sBIT, 2226 (png_const_structp png_ptr, png_infop info_ptr, 2227 png_color_8p *sig_bit)); 2228 #endif 2229 2230 #ifdef PNG_sBIT_SUPPORTED 2231 PNG_EXPORT(154, void, png_set_sBIT, 2232 (png_structp png_ptr, png_infop info_ptr, png_const_color_8p sig_bit)); 2233 #endif 2234 2235 #ifdef PNG_sRGB_SUPPORTED 2236 PNG_EXPORT(155, png_uint_32, png_get_sRGB, (png_const_structp png_ptr, 2237 png_const_infop info_ptr, int *file_srgb_intent)); 2238 #endif 2239 2240 #ifdef PNG_sRGB_SUPPORTED 2241 PNG_EXPORT(156, void, png_set_sRGB, 2242 (png_structp png_ptr, png_infop info_ptr, int srgb_intent)); 2243 PNG_EXPORT(157, void, png_set_sRGB_gAMA_and_cHRM, (png_structp png_ptr, 2244 png_infop info_ptr, int srgb_intent)); 2245 #endif 2246 2247 #ifdef PNG_iCCP_SUPPORTED 2248 PNG_EXPORT(158, png_uint_32, png_get_iCCP, 2249 (png_const_structp png_ptr, png_const_infop info_ptr, 2250 png_charpp name, int *compression_type, png_bytepp profile, 2251 png_uint_32 *proflen)); 2252 #endif 2253 2254 #ifdef PNG_iCCP_SUPPORTED 2255 PNG_EXPORT(159, void, png_set_iCCP, 2256 (png_structp png_ptr, png_infop info_ptr, 2257 png_const_charp name, int compression_type, png_const_bytep profile, 2258 png_uint_32 proflen)); 2259 #endif 2260 2261 #ifdef PNG_sPLT_SUPPORTED 2262 PNG_EXPORT(160, png_uint_32, png_get_sPLT, 2263 (png_const_structp png_ptr, png_const_infop info_ptr, 2264 png_sPLT_tpp entries)); 2265 #endif 2266 2267 #ifdef PNG_sPLT_SUPPORTED 2268 PNG_EXPORT(161, void, png_set_sPLT, 2269 (png_structp png_ptr, png_infop info_ptr, 2270 png_const_sPLT_tp entries, int nentries)); 2271 #endif 2272 2273 #ifdef PNG_TEXT_SUPPORTED 2274 /* png_get_text also returns the number of text chunks in *num_text */ 2275 PNG_EXPORT(162, png_uint_32, png_get_text, 2276 (png_const_structp png_ptr, png_const_infop info_ptr, 2277 png_textp *text_ptr, int *num_text)); 2278 #endif 2279 2280 /* Note while png_set_text() will accept a structure whose text, 2281 * language, and translated keywords are NULL pointers, the structure 2282 * returned by png_get_text will always contain regular 2283 * zero-terminated C strings. They might be empty strings but 2284 * they will never be NULL pointers. 2285 */ 2286 2287 #ifdef PNG_TEXT_SUPPORTED 2288 PNG_EXPORT(163, void, png_set_text, 2289 (png_structp png_ptr, png_infop info_ptr, 2290 png_const_textp text_ptr, int num_text)); 2291 #endif 2292 2293 #ifdef PNG_tIME_SUPPORTED 2294 PNG_EXPORT(164, png_uint_32, png_get_tIME, 2295 (png_const_structp png_ptr, png_infop info_ptr, png_timep *mod_time)); 2296 #endif 2297 2298 #ifdef PNG_tIME_SUPPORTED 2299 PNG_EXPORT(165, void, png_set_tIME, 2300 (png_structp png_ptr, png_infop info_ptr, png_const_timep mod_time)); 2301 #endif 2302 2303 #ifdef PNG_tRNS_SUPPORTED 2304 PNG_EXPORT(166, png_uint_32, png_get_tRNS, 2305 (png_const_structp png_ptr, png_infop info_ptr, 2306 png_bytep *trans_alpha, int *num_trans, png_color_16p *trans_color)); 2307 #endif 2308 2309 #ifdef PNG_tRNS_SUPPORTED 2310 PNG_EXPORT(167, void, png_set_tRNS, 2311 (png_structp png_ptr, png_infop info_ptr, 2312 png_const_bytep trans_alpha, int num_trans, 2313 png_const_color_16p trans_color)); 2314 #endif 2315 2316 #ifdef PNG_sCAL_SUPPORTED 2317 PNG_FP_EXPORT(168, png_uint_32, png_get_sCAL, 2318 (png_const_structp png_ptr, png_const_infop info_ptr, 2319 int *unit, double *width, double *height)) 2320 #ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED 2321 /* NOTE: this API is currently implemented using floating point arithmetic, 2322 * consequently it can only be used on systems with floating point support. 2323 * In any case the range of values supported by png_fixed_point is small and it 2324 * is highly recommended that png_get_sCAL_s be used instead. 2325 */ 2326 PNG_FIXED_EXPORT(214, png_uint_32, png_get_sCAL_fixed, 2327 (png_structp png_ptr, png_const_infop info_ptr, int *unit, 2328 png_fixed_point *width, 2329 png_fixed_point *height)) 2330 #endif 2331 PNG_EXPORT(169, png_uint_32, png_get_sCAL_s, 2332 (png_const_structp png_ptr, png_const_infop info_ptr, 2333 int *unit, png_charpp swidth, png_charpp sheight)); 2334 2335 PNG_FP_EXPORT(170, void, png_set_sCAL, 2336 (png_structp png_ptr, png_infop info_ptr, 2337 int unit, double width, double height)) 2338 PNG_FIXED_EXPORT(213, void, png_set_sCAL_fixed, (png_structp png_ptr, 2339 png_infop info_ptr, int unit, png_fixed_point width, 2340 png_fixed_point height)) 2341 PNG_EXPORT(171, void, png_set_sCAL_s, 2342 (png_structp png_ptr, png_infop info_ptr, 2343 int unit, png_const_charp swidth, png_const_charp sheight)); 2344 #endif /* PNG_sCAL_SUPPORTED */ 2345 2346 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED 2347 /* Provide a list of chunks and how they are to be handled, if the built-in 2348 handling or default unknown chunk handling is not desired. Any chunks not 2349 listed will be handled in the default manner. The IHDR and IEND chunks 2350 must not be listed. Because this turns off the default handling for chunks 2351 that would otherwise be recognized the behavior of libpng transformations may 2352 well become incorrect! 2353 keep = 0: PNG_HANDLE_CHUNK_AS_DEFAULT: follow default behavior 2354 = 1: PNG_HANDLE_CHUNK_NEVER: do not keep 2355 = 2: PNG_HANDLE_CHUNK_IF_SAFE: keep only if safe-to-copy 2356 = 3: PNG_HANDLE_CHUNK_ALWAYS: keep even if unsafe-to-copy 2357 */ 2358 PNG_EXPORT(172, void, png_set_keep_unknown_chunks, 2359 (png_structp png_ptr, int keep, 2360 png_const_bytep chunk_list, int num_chunks)); 2361 2362 /* The handling code is returned; the result is therefore true (non-zero) if 2363 * special handling is required, false for the default handling. 2364 */ 2365 PNG_EXPORT(173, int, png_handle_as_unknown, (png_structp png_ptr, 2366 png_const_bytep chunk_name)); 2367 #endif 2368 #ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED 2369 PNG_EXPORT(174, void, png_set_unknown_chunks, (png_structp png_ptr, 2370 png_infop info_ptr, png_const_unknown_chunkp unknowns, 2371 int num_unknowns)); 2372 PNG_EXPORT(175, void, png_set_unknown_chunk_location, 2373 (png_structp png_ptr, png_infop info_ptr, int chunk, int location)); 2374 PNG_EXPORT(176, int, png_get_unknown_chunks, (png_const_structp png_ptr, 2375 png_const_infop info_ptr, png_unknown_chunkpp entries)); 2376 #endif 2377 2378 /* Png_free_data() will turn off the "valid" flag for anything it frees. 2379 * If you need to turn it off for a chunk that your application has freed, 2380 * you can use png_set_invalid(png_ptr, info_ptr, PNG_INFO_CHNK); 2381 */ 2382 PNG_EXPORT(177, void, png_set_invalid, 2383 (png_structp png_ptr, png_infop info_ptr, int mask)); 2384 2385 #ifdef PNG_INFO_IMAGE_SUPPORTED 2386 /* The "params" pointer is currently not used and is for future expansion. */ 2387 PNG_EXPORT(178, void, png_read_png, (png_structp png_ptr, png_infop info_ptr, 2388 int transforms, png_voidp params)); 2389 PNG_EXPORT(179, void, png_write_png, (png_structp png_ptr, png_infop info_ptr, 2390 int transforms, png_voidp params)); 2391 #endif 2392 2393 PNG_EXPORT(180, png_const_charp, png_get_copyright, 2394 (png_const_structp png_ptr)); 2395 PNG_EXPORT(181, png_const_charp, png_get_header_ver, 2396 (png_const_structp png_ptr)); 2397 PNG_EXPORT(182, png_const_charp, png_get_header_version, 2398 (png_const_structp png_ptr)); 2399 PNG_EXPORT(183, png_const_charp, png_get_libpng_ver, 2400 (png_const_structp png_ptr)); 2401 2402 #ifdef PNG_MNG_FEATURES_SUPPORTED 2403 PNG_EXPORT(184, png_uint_32, png_permit_mng_features, (png_structp png_ptr, 2404 png_uint_32 mng_features_permitted)); 2405 #endif 2406 2407 /* For use in png_set_keep_unknown, added to version 1.2.6 */ 2408 #define PNG_HANDLE_CHUNK_AS_DEFAULT 0 2409 #define PNG_HANDLE_CHUNK_NEVER 1 2410 #define PNG_HANDLE_CHUNK_IF_SAFE 2 2411 #define PNG_HANDLE_CHUNK_ALWAYS 3 2412 2413 /* Strip the prepended error numbers ("#nnn ") from error and warning 2414 * messages before passing them to the error or warning handler. 2415 */ 2416 #ifdef PNG_ERROR_NUMBERS_SUPPORTED 2417 PNG_EXPORT(185, void, png_set_strip_error_numbers, 2418 (png_structp png_ptr, 2419 png_uint_32 strip_mode)); 2420 #endif 2421 2422 /* Added in libpng-1.2.6 */ 2423 #ifdef PNG_SET_USER_LIMITS_SUPPORTED 2424 PNG_EXPORT(186, void, png_set_user_limits, (png_structp png_ptr, 2425 png_uint_32 user_width_max, png_uint_32 user_height_max)); 2426 PNG_EXPORT(187, png_uint_32, png_get_user_width_max, 2427 (png_const_structp png_ptr)); 2428 PNG_EXPORT(188, png_uint_32, png_get_user_height_max, 2429 (png_const_structp png_ptr)); 2430 /* Added in libpng-1.4.0 */ 2431 PNG_EXPORT(189, void, png_set_chunk_cache_max, (png_structp png_ptr, 2432 png_uint_32 user_chunk_cache_max)); 2433 PNG_EXPORT(190, png_uint_32, png_get_chunk_cache_max, 2434 (png_const_structp png_ptr)); 2435 /* Added in libpng-1.4.1 */ 2436 PNG_EXPORT(191, void, png_set_chunk_malloc_max, (png_structp png_ptr, 2437 png_alloc_size_t user_chunk_cache_max)); 2438 PNG_EXPORT(192, png_alloc_size_t, png_get_chunk_malloc_max, 2439 (png_const_structp png_ptr)); 2440 #endif 2441 2442 #if defined(PNG_INCH_CONVERSIONS_SUPPORTED) 2443 PNG_EXPORT(193, png_uint_32, png_get_pixels_per_inch, 2444 (png_const_structp png_ptr, png_const_infop info_ptr)); 2445 2446 PNG_EXPORT(194, png_uint_32, png_get_x_pixels_per_inch, 2447 (png_const_structp png_ptr, png_const_infop info_ptr)); 2448 2449 PNG_EXPORT(195, png_uint_32, png_get_y_pixels_per_inch, 2450 (png_const_structp png_ptr, png_const_infop info_ptr)); 2451 2452 PNG_FP_EXPORT(196, float, png_get_x_offset_inches, 2453 (png_const_structp png_ptr, png_const_infop info_ptr)) 2454 #ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */ 2455 PNG_FIXED_EXPORT(211, png_fixed_point, png_get_x_offset_inches_fixed, 2456 (png_structp png_ptr, png_const_infop info_ptr)) 2457 #endif 2458 2459 PNG_FP_EXPORT(197, float, png_get_y_offset_inches, (png_const_structp png_ptr, 2460 png_const_infop info_ptr)) 2461 #ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */ 2462 PNG_FIXED_EXPORT(212, png_fixed_point, png_get_y_offset_inches_fixed, 2463 (png_structp png_ptr, png_const_infop info_ptr)) 2464 #endif 2465 2466 # ifdef PNG_pHYs_SUPPORTED 2467 PNG_EXPORT(198, png_uint_32, png_get_pHYs_dpi, (png_const_structp png_ptr, 2468 png_const_infop info_ptr, png_uint_32 *res_x, png_uint_32 *res_y, 2469 int *unit_type)); 2470 # endif /* PNG_pHYs_SUPPORTED */ 2471 #endif /* PNG_INCH_CONVERSIONS_SUPPORTED */ 2472 2473 /* Added in libpng-1.4.0 */ 2474 #ifdef PNG_IO_STATE_SUPPORTED 2475 PNG_EXPORT(199, png_uint_32, png_get_io_state, (png_structp png_ptr)); 2476 2477 PNG_EXPORTA(200, png_const_bytep, png_get_io_chunk_name, 2478 (png_structp png_ptr), PNG_DEPRECATED); 2479 PNG_EXPORT(216, png_uint_32, png_get_io_chunk_type, 2480 (png_const_structp png_ptr)); 2481 2482 /* The flags returned by png_get_io_state() are the following: */ 2483 # define PNG_IO_NONE 0x0000 /* no I/O at this moment */ 2484 # define PNG_IO_READING 0x0001 /* currently reading */ 2485 # define PNG_IO_WRITING 0x0002 /* currently writing */ 2486 # define PNG_IO_SIGNATURE 0x0010 /* currently at the file signature */ 2487 # define PNG_IO_CHUNK_HDR 0x0020 /* currently at the chunk header */ 2488 # define PNG_IO_CHUNK_DATA 0x0040 /* currently at the chunk data */ 2489 # define PNG_IO_CHUNK_CRC 0x0080 /* currently at the chunk crc */ 2490 # define PNG_IO_MASK_OP 0x000f /* current operation: reading/writing */ 2491 # define PNG_IO_MASK_LOC 0x00f0 /* current location: sig/hdr/data/crc */ 2492 #endif /* ?PNG_IO_STATE_SUPPORTED */ 2493 2494 /* Interlace support. The following macros are always defined so that if 2495 * libpng interlace handling is turned off the macros may be used to handle 2496 * interlaced images within the application. 2497 */ 2498 #define PNG_INTERLACE_ADAM7_PASSES 7 2499 2500 /* Two macros to return the first row and first column of the original, 2501 * full, image which appears in a given pass. 'pass' is in the range 0 2502 * to 6 and the result is in the range 0 to 7. 2503 */ 2504 #define PNG_PASS_START_ROW(pass) (((1&~(pass))<<(3-((pass)>>1)))&7) 2505 #define PNG_PASS_START_COL(pass) (((1& (pass))<<(3-(((pass)+1)>>1)))&7) 2506 2507 /* A macro to return the offset between pixels in the output row for a pair of 2508 * pixels in the input - effectively the inverse of the 'COL_SHIFT' macro that 2509 * follows. Note that ROW_OFFSET is the offset from one row to the next whereas 2510 * COL_OFFSET is from one column to the next, within a row. 2511 */ 2512 #define PNG_PASS_ROW_OFFSET(pass) ((pass)>2?(8>>(((pass)-1)>>1)):8) 2513 #define PNG_PASS_COL_OFFSET(pass) (1<<((7-(pass))>>1)) 2514 2515 /* Two macros to help evaluate the number of rows or columns in each 2516 * pass. This is expressed as a shift - effectively log2 of the number or 2517 * rows or columns in each 8x8 tile of the original image. 2518 */ 2519 #define PNG_PASS_ROW_SHIFT(pass) ((pass)>2?(8-(pass))>>1:3) 2520 #define PNG_PASS_COL_SHIFT(pass) ((pass)>1?(7-(pass))>>1:3) 2521 2522 /* Hence two macros to determine the number of rows or columns in a given 2523 * pass of an image given its height or width. In fact these macros may 2524 * return non-zero even though the sub-image is empty, because the other 2525 * dimension may be empty for a small image. 2526 */ 2527 #define PNG_PASS_ROWS(height, pass) (((height)+(((1<<PNG_PASS_ROW_SHIFT(pass))\ 2528 -1)-PNG_PASS_START_ROW(pass)))>>PNG_PASS_ROW_SHIFT(pass)) 2529 #define PNG_PASS_COLS(width, pass) (((width)+(((1<<PNG_PASS_COL_SHIFT(pass))\ 2530 -1)-PNG_PASS_START_COL(pass)))>>PNG_PASS_COL_SHIFT(pass)) 2531 2532 /* For the reader row callbacks (both progressive and sequential) it is 2533 * necessary to find the row in the output image given a row in an interlaced 2534 * image, so two more macros: 2535 */ 2536 #define PNG_ROW_FROM_PASS_ROW(yIn, pass) \ 2537 (((yIn)<<PNG_PASS_ROW_SHIFT(pass))+PNG_PASS_START_ROW(pass)) 2538 #define PNG_COL_FROM_PASS_COL(xIn, pass) \ 2539 (((xIn)<<PNG_PASS_COL_SHIFT(pass))+PNG_PASS_START_COL(pass)) 2540 2541 /* Two macros which return a boolean (0 or 1) saying whether the given row 2542 * or column is in a particular pass. These use a common utility macro that 2543 * returns a mask for a given pass - the offset 'off' selects the row or 2544 * column version. The mask has the appropriate bit set for each column in 2545 * the tile. 2546 */ 2547 #define PNG_PASS_MASK(pass,off) ( \ 2548 ((0x110145AF>>(((7-(off))-(pass))<<2)) & 0xF) | \ 2549 ((0x01145AF0>>(((7-(off))-(pass))<<2)) & 0xF0)) 2550 2551 #define PNG_ROW_IN_INTERLACE_PASS(y, pass) \ 2552 ((PNG_PASS_MASK(pass,0) >> ((y)&7)) & 1) 2553 #define PNG_COL_IN_INTERLACE_PASS(x, pass) \ 2554 ((PNG_PASS_MASK(pass,1) >> ((x)&7)) & 1) 2555 2556 #ifdef PNG_READ_COMPOSITE_NODIV_SUPPORTED 2557 /* With these routines we avoid an integer divide, which will be slower on 2558 * most machines. However, it does take more operations than the corresponding 2559 * divide method, so it may be slower on a few RISC systems. There are two 2560 * shifts (by 8 or 16 bits) and an addition, versus a single integer divide. 2561 * 2562 * Note that the rounding factors are NOT supposed to be the same! 128 and 2563 * 32768 are correct for the NODIV code; 127 and 32767 are correct for the 2564 * standard method. 2565 * 2566 * [Optimized code by Greg Roelofs and Mark Adler...blame us for bugs. :-) ] 2567 */ 2568 2569 /* fg and bg should be in `gamma 1.0' space; alpha is the opacity */ 2570 2571 # define png_composite(composite, fg, alpha, bg) \ 2572 { png_uint_16 temp = (png_uint_16)((png_uint_16)(fg) \ 2573 * (png_uint_16)(alpha) \ 2574 + (png_uint_16)(bg)*(png_uint_16)(255 \ 2575 - (png_uint_16)(alpha)) + 128); \ 2576 (composite) = (png_byte)((temp + (temp >> 8)) >> 8); } 2577 2578 # define png_composite_16(composite, fg, alpha, bg) \ 2579 { png_uint_32 temp = (png_uint_32)((png_uint_32)(fg) \ 2580 * (png_uint_32)(alpha) \ 2581 + (png_uint_32)(bg)*(65535 \ 2582 - (png_uint_32)(alpha)) + 32768); \ 2583 (composite) = (png_uint_16)((temp + (temp >> 16)) >> 16); } 2584 2585 #else /* Standard method using integer division */ 2586 2587 # define png_composite(composite, fg, alpha, bg) \ 2588 (composite) = (png_byte)(((png_uint_16)(fg) * (png_uint_16)(alpha) + \ 2589 (png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) + \ 2590 127) / 255) 2591 2592 # define png_composite_16(composite, fg, alpha, bg) \ 2593 (composite) = (png_uint_16)(((png_uint_32)(fg) * (png_uint_32)(alpha) + \ 2594 (png_uint_32)(bg)*(png_uint_32)(65535 - (png_uint_32)(alpha)) + \ 2595 32767) / 65535) 2596 #endif /* PNG_READ_COMPOSITE_NODIV_SUPPORTED */ 2597 2598 #ifdef PNG_READ_INT_FUNCTIONS_SUPPORTED 2599 PNG_EXPORT(201, png_uint_32, png_get_uint_32, (png_const_bytep buf)); 2600 PNG_EXPORT(202, png_uint_16, png_get_uint_16, (png_const_bytep buf)); 2601 PNG_EXPORT(203, png_int_32, png_get_int_32, (png_const_bytep buf)); 2602 #endif 2603 2604 PNG_EXPORT(204, png_uint_32, png_get_uint_31, (png_structp png_ptr, 2605 png_const_bytep buf)); 2606 /* No png_get_int_16 -- may be added if there's a real need for it. */ 2607 2608 /* Place a 32-bit number into a buffer in PNG byte order (big-endian). */ 2609 #ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED 2610 PNG_EXPORT(205, void, png_save_uint_32, (png_bytep buf, png_uint_32 i)); 2611 #endif 2612 #ifdef PNG_SAVE_INT_32_SUPPORTED 2613 PNG_EXPORT(206, void, png_save_int_32, (png_bytep buf, png_int_32 i)); 2614 #endif 2615 2616 /* Place a 16-bit number into a buffer in PNG byte order. 2617 * The parameter is declared unsigned int, not png_uint_16, 2618 * just to avoid potential problems on pre-ANSI C compilers. 2619 */ 2620 #ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED 2621 PNG_EXPORT(207, void, png_save_uint_16, (png_bytep buf, unsigned int i)); 2622 /* No png_save_int_16 -- may be added if there's a real need for it. */ 2623 #endif 2624 2625 #ifdef PNG_USE_READ_MACROS 2626 /* Inline macros to do direct reads of bytes from the input buffer. 2627 * The png_get_int_32() routine assumes we are using two's complement 2628 * format for negative values, which is almost certainly true. 2629 */ 2630 # define png_get_uint_32(buf) \ 2631 (((png_uint_32)(*(buf)) << 24) + \ 2632 ((png_uint_32)(*((buf) + 1)) << 16) + \ 2633 ((png_uint_32)(*((buf) + 2)) << 8) + \ 2634 ((png_uint_32)(*((buf) + 3)))) 2635 2636 /* From libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the 2637 * function) incorrectly returned a value of type png_uint_32. 2638 */ 2639 # define png_get_uint_16(buf) \ 2640 ((png_uint_16) \ 2641 (((unsigned int)(*(buf)) << 8) + \ 2642 ((unsigned int)(*((buf) + 1))))) 2643 2644 # define png_get_int_32(buf) \ 2645 ((png_int_32)((*(buf) & 0x80) \ 2646 ? -((png_int_32)((png_get_uint_32(buf) ^ 0xffffffffL) + 1)) \ 2647 : (png_int_32)png_get_uint_32(buf))) 2648 #endif 2649 2650 #if defined(PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED) || \ 2651 defined(PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED) 2652 PNG_EXPORT(234, void, png_set_check_for_invalid_index, (png_structp png_ptr, 2653 int allowed)); 2654 #endif 2655 2656 /* Maintainer: Put new public prototypes here ^, in libpng.3, and project 2657 * defs 2658 */ 2659 2660 /* The last ordinal number (this is the *last* one already used; the next 2661 * one to use is one more than this.) Maintainer, remember to add an entry to 2662 * scripts/symbols.def as well. 2663 */ 2664 #ifdef PNG_EXPORT_LAST_ORDINAL 2665 PNG_EXPORT_LAST_ORDINAL(234); 2666 #endif 2667 2668 #ifdef __cplusplus 2669 } 2670 #endif 2671 2672 #endif /* PNG_VERSION_INFO_ONLY */ 2673 /* Do not put anything past this line */ 2674 #endif /* PNG_H */ 2675
