1 2 /* png.h - header file for PNG reference library 3 * 4 * libpng version 1.6.10 - March 6, 2014 5 * Copyright (c) 1998-2014 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 1.6.10 - March 6, 2014: 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 * 1.6.0beta01-40 16 10600 16.so.16.0[.0] 170 * 1.6.0rc01-08 16 10600 16.so.16.0[.0] 171 * 1.6.0 16 10600 16.so.16.0[.0] 172 * 1.6.1beta01-09 16 10601 16.so.16.1[.0] 173 * 1.6.1rc01 16 10601 16.so.16.1[.0] 174 * 1.6.1 16 10601 16.so.16.1[.0] 175 * 1.6.2beta01 16 10602 16.so.16.2[.0] 176 * 1.6.2rc01-06 16 10602 16.so.16.2[.0] 177 * 1.6.2 16 10602 16.so.16.2[.0] 178 * 1.6.3beta01-11 16 10603 16.so.16.3[.0] 179 * 1.6.3rc01 16 10603 16.so.16.3[.0] 180 * 1.6.3 16 10603 16.so.16.3[.0] 181 * 1.6.4beta01-02 16 10604 16.so.16.4[.0] 182 * 1.6.4rc01 16 10604 16.so.16.4[.0] 183 * 1.6.4 16 10604 16.so.16.4[.0] 184 * 1.6.5 16 10605 16.so.16.5[.0] 185 * 1.6.6 16 10606 16.so.16.6[.0] 186 * 1.6.7beta01-04 16 10607 16.so.16.7[.0] 187 * 1.6.7rc01-03 16 10607 16.so.16.7[.0] 188 * 1.6.7 16 10607 16.so.16.7[.0] 189 * 1.6.8beta01-02 16 10608 16.so.16.8[.0] 190 * 1.6.8rc01-02 16 10608 16.so.16.8[.0] 191 * 1.6.8 16 10608 16.so.16.8[.0] 192 * 1.6.9beta01-04 16 10609 16.so.16.9[.0] 193 * 1.6.9rc01-02 16 10609 16.so.16.9[.0] 194 * 1.6.9 16 10609 16.so.16.9[.0] 195 * 1.6.10beta01-03 16 10610 16.so.16.10[.0] 196 * 1.6.10betarc01-04 16 10610 16.so.16.10[.0] 197 * 1.6.10beta 16 10610 16.so.16.10[.0] 198 * 199 * Henceforth the source version will match the shared-library major 200 * and minor numbers; the shared-library major version number will be 201 * used for changes in backward compatibility, as it is intended. The 202 * PNG_LIBPNG_VER macro, which is not used within libpng but is available 203 * for applications, is an unsigned integer of the form xyyzz corresponding 204 * to the source version x.y.z (leading zeros in y and z). Beta versions 205 * were given the previous public release number plus a letter, until 206 * version 1.0.6j; from then on they were given the upcoming public 207 * release number plus "betaNN" or "rcNN". 208 * 209 * Binary incompatibility exists only when applications make direct access 210 * to the info_ptr or png_ptr members through png.h, and the compiled 211 * application is loaded with a different version of the library. 212 * 213 * DLLNUM will change each time there are forward or backward changes 214 * in binary compatibility (e.g., when a new feature is added). 215 * 216 * See libpng-manual.txt or libpng.3 for more information. The PNG 217 * specification is available as a W3C Recommendation and as an ISO 218 * Specification, <http://www.w3.org/TR/2003/REC-PNG-20031110/ 219 */ 220 221 /* 222 * COPYRIGHT NOTICE, DISCLAIMER, and LICENSE: 223 * 224 * If you modify libpng you may insert additional notices immediately following 225 * this sentence. 226 * 227 * This code is released under the libpng license. 228 * 229 * libpng versions 1.2.6, August 15, 2004, through 1.6.10, March 6, 2014, are 230 * Copyright (c) 2004, 2006-2013 Glenn Randers-Pehrson, and are 231 * distributed according to the same disclaimer and license as libpng-1.2.5 232 * with the following individual added to the list of Contributing Authors: 233 * 234 * Cosmin Truta 235 * 236 * libpng versions 1.0.7, July 1, 2000, through 1.2.5, October 3, 2002, are 237 * Copyright (c) 2000-2002 Glenn Randers-Pehrson, and are 238 * distributed according to the same disclaimer and license as libpng-1.0.6 239 * with the following individuals added to the list of Contributing Authors: 240 * 241 * Simon-Pierre Cadieux 242 * Eric S. Raymond 243 * Gilles Vollant 244 * 245 * and with the following additions to the disclaimer: 246 * 247 * There is no warranty against interference with your enjoyment of the 248 * library or against infringement. There is no warranty that our 249 * efforts or the library will fulfill any of your particular purposes 250 * or needs. This library is provided with all faults, and the entire 251 * risk of satisfactory quality, performance, accuracy, and effort is with 252 * the user. 253 * 254 * libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are 255 * Copyright (c) 1998, 1999, 2000 Glenn Randers-Pehrson, and are 256 * distributed according to the same disclaimer and license as libpng-0.96, 257 * with the following individuals added to the list of Contributing Authors: 258 * 259 * Tom Lane 260 * Glenn Randers-Pehrson 261 * Willem van Schaik 262 * 263 * libpng versions 0.89, June 1996, through 0.96, May 1997, are 264 * Copyright (c) 1996, 1997 Andreas Dilger 265 * Distributed according to the same disclaimer and license as libpng-0.88, 266 * with the following individuals added to the list of Contributing Authors: 267 * 268 * John Bowler 269 * Kevin Bracey 270 * Sam Bushell 271 * Magnus Holmgren 272 * Greg Roelofs 273 * Tom Tanner 274 * 275 * libpng versions 0.5, May 1995, through 0.88, January 1996, are 276 * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. 277 * 278 * For the purposes of this copyright and license, "Contributing Authors" 279 * is defined as the following set of individuals: 280 * 281 * Andreas Dilger 282 * Dave Martindale 283 * Guy Eric Schalnat 284 * Paul Schmidt 285 * Tim Wegner 286 * 287 * The PNG Reference Library is supplied "AS IS". The Contributing Authors 288 * and Group 42, Inc. disclaim all warranties, expressed or implied, 289 * including, without limitation, the warranties of merchantability and of 290 * fitness for any purpose. The Contributing Authors and Group 42, Inc. 291 * assume no liability for direct, indirect, incidental, special, exemplary, 292 * or consequential damages, which may result from the use of the PNG 293 * Reference Library, even if advised of the possibility of such damage. 294 * 295 * Permission is hereby granted to use, copy, modify, and distribute this 296 * source code, or portions hereof, for any purpose, without fee, subject 297 * to the following restrictions: 298 * 299 * 1. The origin of this source code must not be misrepresented. 300 * 301 * 2. Altered versions must be plainly marked as such and must not 302 * be misrepresented as being the original source. 303 * 304 * 3. This Copyright notice may not be removed or altered from 305 * any source or altered source distribution. 306 * 307 * The Contributing Authors and Group 42, Inc. specifically permit, without 308 * fee, and encourage the use of this source code as a component to 309 * supporting the PNG file format in commercial products. If you use this 310 * source code in a product, acknowledgment is not required but would be 311 * appreciated. 312 */ 313 314 /* 315 * A "png_get_copyright" function is available, for convenient use in "about" 316 * boxes and the like: 317 * 318 * printf("%s", png_get_copyright(NULL)); 319 * 320 * Also, the PNG logo (in PNG format, of course) is supplied in the 321 * files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31). 322 */ 323 324 /* 325 * Libpng is OSI Certified Open Source Software. OSI Certified is a 326 * certification mark of the Open Source Initiative. 327 */ 328 329 /* 330 * The contributing authors would like to thank all those who helped 331 * with testing, bug fixes, and patience. This wouldn't have been 332 * possible without all of you. 333 * 334 * Thanks to Frank J. T. Wojcik for helping with the documentation. 335 */ 336 337 /* 338 * Y2K compliance in libpng: 339 * ========================= 340 * 341 * March 6, 2014 342 * 343 * Since the PNG Development group is an ad-hoc body, we can't make 344 * an official declaration. 345 * 346 * This is your unofficial assurance that libpng from version 0.71 and 347 * upward through 1.6.10 are Y2K compliant. It is my belief that 348 * earlier versions were also Y2K compliant. 349 * 350 * Libpng only has two year fields. One is a 2-byte unsigned integer 351 * that will hold years up to 65535. The other, which is deprecated, 352 * holds the date in text format, and will hold years up to 9999. 353 * 354 * The integer is 355 * "png_uint_16 year" in png_time_struct. 356 * 357 * The string is 358 * "char time_buffer[29]" in png_struct. This is no longer used 359 * in libpng-1.6.x and will be removed from libpng-1.7.0. 360 * 361 * There are seven time-related functions: 362 * png.c: png_convert_to_rfc_1123_buffer() in png.c 363 * (formerly png_convert_to_rfc_1123() prior to libpng-1.5.x and 364 * png_convert_to_rfc_1152() in error prior to libpng-0.98) 365 * png_convert_from_struct_tm() in pngwrite.c, called in pngwrite.c 366 * png_convert_from_time_t() in pngwrite.c 367 * png_get_tIME() in pngget.c 368 * png_handle_tIME() in pngrutil.c, called in pngread.c 369 * png_set_tIME() in pngset.c 370 * png_write_tIME() in pngwutil.c, called in pngwrite.c 371 * 372 * All handle dates properly in a Y2K environment. The 373 * png_convert_from_time_t() function calls gmtime() to convert from system 374 * clock time, which returns (year - 1900), which we properly convert to 375 * the full 4-digit year. There is a possibility that libpng applications 376 * are not passing 4-digit years into the png_convert_to_rfc_1123_buffer() 377 * function, or that they are incorrectly passing only a 2-digit year 378 * instead of "year - 1900" into the png_convert_from_struct_tm() function, 379 * but this is not under our control. The libpng documentation has always 380 * stated that it works with 4-digit years, and the APIs have been 381 * documented as such. 382 * 383 * The tIME chunk itself is also Y2K compliant. It uses a 2-byte unsigned 384 * integer to hold the year, and can hold years as large as 65535. 385 * 386 * zlib, upon which libpng depends, is also Y2K compliant. It contains 387 * no date-related code. 388 * 389 * Glenn Randers-Pehrson 390 * libpng maintainer 391 * PNG Development Group 392 */ 393 394 #ifndef PNG_H 395 #define PNG_H 396 397 /* This is not the place to learn how to use libpng. The file libpng-manual.txt 398 * describes how to use libpng, and the file example.c summarizes it 399 * with some code on which to build. This file is useful for looking 400 * at the actual function definitions and structure components. 401 * 402 * If you just need to read a PNG file and don't want to read the documentation 403 * skip to the end of this file and read the section entitled 'simplified API'. 404 */ 405 406 /* Version information for png.h - this should match the version in png.c */ 407 #define PNG_LIBPNG_VER_STRING "1.6.10" 408 #define PNG_HEADER_VERSION_STRING \ 409 " libpng version 1.6.10 - March 6, 2014\n" 410 411 #define PNG_LIBPNG_VER_SONUM 16 412 #define PNG_LIBPNG_VER_DLLNUM 16 413 414 /* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */ 415 #define PNG_LIBPNG_VER_MAJOR 1 416 #define PNG_LIBPNG_VER_MINOR 6 417 #define PNG_LIBPNG_VER_RELEASE 10 418 419 /* This should match the numeric part of the final component of 420 * PNG_LIBPNG_VER_STRING, omitting any leading zero: 421 */ 422 423 #define PNG_LIBPNG_VER_BUILD 0 424 425 /* Release Status */ 426 #define PNG_LIBPNG_BUILD_ALPHA 1 427 #define PNG_LIBPNG_BUILD_BETA 2 428 #define PNG_LIBPNG_BUILD_RC 3 429 #define PNG_LIBPNG_BUILD_STABLE 4 430 #define PNG_LIBPNG_BUILD_RELEASE_STATUS_MASK 7 431 432 /* Release-Specific Flags */ 433 #define PNG_LIBPNG_BUILD_PATCH 8 /* Can be OR'ed with 434 PNG_LIBPNG_BUILD_STABLE only */ 435 #define PNG_LIBPNG_BUILD_PRIVATE 16 /* Cannot be OR'ed with 436 PNG_LIBPNG_BUILD_SPECIAL */ 437 #define PNG_LIBPNG_BUILD_SPECIAL 32 /* Cannot be OR'ed with 438 PNG_LIBPNG_BUILD_PRIVATE */ 439 440 #define PNG_LIBPNG_BUILD_BASE_TYPE PNG_LIBPNG_BUILD_STABLE 441 442 /* Careful here. At one time, Guy wanted to use 082, but that would be octal. 443 * We must not include leading zeros. 444 * Versions 0.7 through 1.0.0 were in the range 0 to 100 here (only 445 * version 1.0.0 was mis-numbered 100 instead of 10000). From 446 * version 1.0.1 it's xxyyzz, where x=major, y=minor, z=release 447 */ 448 #define PNG_LIBPNG_VER 10610 /* 1.6.10 */ 449 450 /* Library configuration: these options cannot be changed after 451 * the library has been built. 452 */ 453 #ifndef PNGLCONF_H 454 /* If pnglibconf.h is missing, you can 455 * copy scripts/pnglibconf.h.prebuilt to pnglibconf.h 456 */ 457 # include "pnglibconf.h" 458 #endif 459 460 #ifndef PNG_VERSION_INFO_ONLY 461 /* Machine specific configuration. */ 462 # include "pngconf.h" 463 #endif 464 465 /* 466 * Added at libpng-1.2.8 467 * 468 * Ref MSDN: Private as priority over Special 469 * VS_FF_PRIVATEBUILD File *was not* built using standard release 470 * procedures. If this value is given, the StringFileInfo block must 471 * contain a PrivateBuild string. 472 * 473 * VS_FF_SPECIALBUILD File *was* built by the original company using 474 * standard release procedures but is a variation of the standard 475 * file of the same version number. If this value is given, the 476 * StringFileInfo block must contain a SpecialBuild string. 477 */ 478 479 #ifdef PNG_USER_PRIVATEBUILD /* From pnglibconf.h */ 480 # define PNG_LIBPNG_BUILD_TYPE \ 481 (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_PRIVATE) 482 #else 483 # ifdef PNG_LIBPNG_SPECIALBUILD 484 # define PNG_LIBPNG_BUILD_TYPE \ 485 (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_SPECIAL) 486 # else 487 # define PNG_LIBPNG_BUILD_TYPE (PNG_LIBPNG_BUILD_BASE_TYPE) 488 # endif 489 #endif 490 491 #ifndef PNG_VERSION_INFO_ONLY 492 493 /* Inhibit C++ name-mangling for libpng functions but not for system calls. */ 494 #ifdef __cplusplus 495 extern "C" { 496 #endif /* __cplusplus */ 497 498 /* Version information for C files, stored in png.c. This had better match 499 * the version above. 500 */ 501 #define png_libpng_ver png_get_header_ver(NULL) 502 503 /* This file is arranged in several sections: 504 * 505 * 1. Any configuration options that can be specified by for the application 506 * code when it is built. (Build time configuration is in pnglibconf.h) 507 * 2. Type definitions (base types are defined in pngconf.h), structure 508 * definitions. 509 * 3. Exported library functions. 510 * 4. Simplified API. 511 * 512 * The library source code has additional files (principally pngpriv.h) that 513 * allow configuration of the library. 514 */ 515 /* Section 1: run time configuration 516 * See pnglibconf.h for build time configuration 517 * 518 * Run time configuration allows the application to choose between 519 * implementations of certain arithmetic APIs. The default is set 520 * at build time and recorded in pnglibconf.h, but it is safe to 521 * override these (and only these) settings. Note that this won't 522 * change what the library does, only application code, and the 523 * settings can (and probably should) be made on a per-file basis 524 * by setting the #defines before including png.h 525 * 526 * Use macros to read integers from PNG data or use the exported 527 * functions? 528 * PNG_USE_READ_MACROS: use the macros (see below) Note that 529 * the macros evaluate their argument multiple times. 530 * PNG_NO_USE_READ_MACROS: call the relevant library function. 531 * 532 * Use the alternative algorithm for compositing alpha samples that 533 * does not use division? 534 * PNG_READ_COMPOSITE_NODIV_SUPPORTED: use the 'no division' 535 * algorithm. 536 * PNG_NO_READ_COMPOSITE_NODIV: use the 'division' algorithm. 537 * 538 * How to handle benign errors if PNG_ALLOW_BENIGN_ERRORS is 539 * false? 540 * PNG_ALLOW_BENIGN_ERRORS: map calls to the benign error 541 * APIs to png_warning. 542 * Otherwise the calls are mapped to png_error. 543 */ 544 545 /* Section 2: type definitions, including structures and compile time 546 * constants. 547 * See pngconf.h for base types that vary by machine/system 548 */ 549 550 /* This triggers a compiler error in png.c, if png.c and png.h 551 * do not agree upon the version number. 552 */ 553 typedef char* png_libpng_version_1_6_10; 554 555 /* Basic control structions. Read libpng-manual.txt or libpng.3 for more info. 556 * 557 * png_struct is the cache of information used while reading or writing a single 558 * PNG file. One of these is always required, although the simplified API 559 * (below) hides the creation and destruction of it. 560 */ 561 typedef struct png_struct_def png_struct; 562 typedef const png_struct * png_const_structp; 563 typedef png_struct * png_structp; 564 typedef png_struct * * png_structpp; 565 566 /* png_info contains information read from or to be written to a PNG file. One 567 * or more of these must exist while reading or creating a PNG file. The 568 * information is not used by libpng during read but is used to control what 569 * gets written when a PNG file is created. "png_get_" function calls read 570 * information during read and "png_set_" functions calls write information 571 * when creating a PNG. 572 * been moved into a separate header file that is not accessible to 573 * applications. Read libpng-manual.txt or libpng.3 for more info. 574 */ 575 typedef struct png_info_def png_info; 576 typedef png_info * png_infop; 577 typedef const png_info * png_const_infop; 578 typedef png_info * * png_infopp; 579 580 /* Types with names ending 'p' are pointer types. The corresponding types with 581 * names ending 'rp' are identical pointer types except that the pointer is 582 * marked 'restrict', which means that it is the only pointer to the object 583 * passed to the function. Applications should not use the 'restrict' types; 584 * it is always valid to pass 'p' to a pointer with a function argument of the 585 * corresponding 'rp' type. Different compilers have different rules with 586 * regard to type matching in the presence of 'restrict'. For backward 587 * compatibility libpng callbacks never have 'restrict' in their parameters and, 588 * consequentially, writing portable application code is extremely difficult if 589 * an attempt is made to use 'restrict'. 590 */ 591 typedef png_struct * PNG_RESTRICT png_structrp; 592 typedef const png_struct * PNG_RESTRICT png_const_structrp; 593 typedef png_info * PNG_RESTRICT png_inforp; 594 typedef const png_info * PNG_RESTRICT png_const_inforp; 595 596 /* Three color definitions. The order of the red, green, and blue, (and the 597 * exact size) is not important, although the size of the fields need to 598 * be png_byte or png_uint_16 (as defined below). 599 */ 600 typedef struct png_color_struct 601 { 602 png_byte red; 603 png_byte green; 604 png_byte blue; 605 } png_color; 606 typedef png_color * png_colorp; 607 typedef const png_color * png_const_colorp; 608 typedef png_color * * png_colorpp; 609 610 typedef struct png_color_16_struct 611 { 612 png_byte index; /* used for palette files */ 613 png_uint_16 red; /* for use in red green blue files */ 614 png_uint_16 green; 615 png_uint_16 blue; 616 png_uint_16 gray; /* for use in grayscale files */ 617 } png_color_16; 618 typedef png_color_16 * png_color_16p; 619 typedef const png_color_16 * png_const_color_16p; 620 typedef png_color_16 * * png_color_16pp; 621 622 typedef struct png_color_8_struct 623 { 624 png_byte red; /* for use in red green blue files */ 625 png_byte green; 626 png_byte blue; 627 png_byte gray; /* for use in grayscale files */ 628 png_byte alpha; /* for alpha channel files */ 629 } png_color_8; 630 typedef png_color_8 * png_color_8p; 631 typedef const png_color_8 * png_const_color_8p; 632 typedef png_color_8 * * png_color_8pp; 633 634 /* 635 * The following two structures are used for the in-core representation 636 * of sPLT chunks. 637 */ 638 typedef struct png_sPLT_entry_struct 639 { 640 png_uint_16 red; 641 png_uint_16 green; 642 png_uint_16 blue; 643 png_uint_16 alpha; 644 png_uint_16 frequency; 645 } png_sPLT_entry; 646 typedef png_sPLT_entry * png_sPLT_entryp; 647 typedef const png_sPLT_entry * png_const_sPLT_entryp; 648 typedef png_sPLT_entry * * png_sPLT_entrypp; 649 650 /* When the depth of the sPLT palette is 8 bits, the color and alpha samples 651 * occupy the LSB of their respective members, and the MSB of each member 652 * is zero-filled. The frequency member always occupies the full 16 bits. 653 */ 654 655 typedef struct png_sPLT_struct 656 { 657 png_charp name; /* palette name */ 658 png_byte depth; /* depth of palette samples */ 659 png_sPLT_entryp entries; /* palette entries */ 660 png_int_32 nentries; /* number of palette entries */ 661 } png_sPLT_t; 662 typedef png_sPLT_t * png_sPLT_tp; 663 typedef const png_sPLT_t * png_const_sPLT_tp; 664 typedef png_sPLT_t * * png_sPLT_tpp; 665 666 #ifdef PNG_TEXT_SUPPORTED 667 /* png_text holds the contents of a text/ztxt/itxt chunk in a PNG file, 668 * and whether that contents is compressed or not. The "key" field 669 * points to a regular zero-terminated C string. The "text" fields can be a 670 * regular C string, an empty string, or a NULL pointer. 671 * However, the structure returned by png_get_text() will always contain 672 * the "text" field as a regular zero-terminated C string (possibly 673 * empty), never a NULL pointer, so it can be safely used in printf() and 674 * other string-handling functions. Note that the "itxt_length", "lang", and 675 * "lang_key" members of the structure only exist when the library is built 676 * with iTXt chunk support. Prior to libpng-1.4.0 the library was built by 677 * default without iTXt support. Also note that when iTXt *is* supported, 678 * the "lang" and "lang_key" fields contain NULL pointers when the 679 * "compression" field contains * PNG_TEXT_COMPRESSION_NONE or 680 * PNG_TEXT_COMPRESSION_zTXt. Note that the "compression value" is not the 681 * same as what appears in the PNG tEXt/zTXt/iTXt chunk's "compression flag" 682 * which is always 0 or 1, or its "compression method" which is always 0. 683 */ 684 typedef struct png_text_struct 685 { 686 int compression; /* compression value: 687 -1: tEXt, none 688 0: zTXt, deflate 689 1: iTXt, none 690 2: iTXt, deflate */ 691 png_charp key; /* keyword, 1-79 character description of "text" */ 692 png_charp text; /* comment, may be an empty string (ie "") 693 or a NULL pointer */ 694 png_size_t text_length; /* length of the text string */ 695 png_size_t itxt_length; /* length of the itxt string */ 696 png_charp lang; /* language code, 0-79 characters 697 or a NULL pointer */ 698 png_charp lang_key; /* keyword translated UTF-8 string, 0 or more 699 chars or a NULL pointer */ 700 } png_text; 701 typedef png_text * png_textp; 702 typedef const png_text * png_const_textp; 703 typedef png_text * * png_textpp; 704 #endif 705 706 /* Supported compression types for text in PNG files (tEXt, and zTXt). 707 * The values of the PNG_TEXT_COMPRESSION_ defines should NOT be changed. */ 708 #define PNG_TEXT_COMPRESSION_NONE_WR -3 709 #define PNG_TEXT_COMPRESSION_zTXt_WR -2 710 #define PNG_TEXT_COMPRESSION_NONE -1 711 #define PNG_TEXT_COMPRESSION_zTXt 0 712 #define PNG_ITXT_COMPRESSION_NONE 1 713 #define PNG_ITXT_COMPRESSION_zTXt 2 714 #define PNG_TEXT_COMPRESSION_LAST 3 /* Not a valid value */ 715 716 /* png_time is a way to hold the time in an machine independent way. 717 * Two conversions are provided, both from time_t and struct tm. There 718 * is no portable way to convert to either of these structures, as far 719 * as I know. If you know of a portable way, send it to me. As a side 720 * note - PNG has always been Year 2000 compliant! 721 */ 722 typedef struct png_time_struct 723 { 724 png_uint_16 year; /* full year, as in, 1995 */ 725 png_byte month; /* month of year, 1 - 12 */ 726 png_byte day; /* day of month, 1 - 31 */ 727 png_byte hour; /* hour of day, 0 - 23 */ 728 png_byte minute; /* minute of hour, 0 - 59 */ 729 png_byte second; /* second of minute, 0 - 60 (for leap seconds) */ 730 } png_time; 731 typedef png_time * png_timep; 732 typedef const png_time * png_const_timep; 733 typedef png_time * * png_timepp; 734 735 #if defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED) ||\ 736 defined(PNG_USER_CHUNKS_SUPPORTED) 737 /* png_unknown_chunk is a structure to hold queued chunks for which there is 738 * no specific support. The idea is that we can use this to queue 739 * up private chunks for output even though the library doesn't actually 740 * know about their semantics. 741 * 742 * The data in the structure is set by libpng on read and used on write. 743 */ 744 typedef struct png_unknown_chunk_t 745 { 746 png_byte name[5]; /* Textual chunk name with '\0' terminator */ 747 png_byte *data; /* Data, should not be modified on read! */ 748 png_size_t size; 749 750 /* On write 'location' must be set using the flag values listed below. 751 * Notice that on read it is set by libpng however the values stored have 752 * more bits set than are listed below. Always treat the value as a 753 * bitmask. On write set only one bit - setting multiple bits may cause the 754 * chunk to be written in multiple places. 755 */ 756 png_byte location; /* mode of operation at read time */ 757 } 758 png_unknown_chunk; 759 760 typedef png_unknown_chunk * png_unknown_chunkp; 761 typedef const png_unknown_chunk * png_const_unknown_chunkp; 762 typedef png_unknown_chunk * * png_unknown_chunkpp; 763 #endif 764 765 /* Flag values for the unknown chunk location byte. */ 766 #define PNG_HAVE_IHDR 0x01 767 #define PNG_HAVE_PLTE 0x02 768 #define PNG_AFTER_IDAT 0x08 769 770 /* Maximum positive integer used in PNG is (2^31)-1 */ 771 #define PNG_UINT_31_MAX ((png_uint_32)0x7fffffffL) 772 #define PNG_UINT_32_MAX ((png_uint_32)(-1)) 773 #define PNG_SIZE_MAX ((png_size_t)(-1)) 774 775 /* These are constants for fixed point values encoded in the 776 * PNG specification manner (x100000) 777 */ 778 #define PNG_FP_1 100000 779 #define PNG_FP_HALF 50000 780 #define PNG_FP_MAX ((png_fixed_point)0x7fffffffL) 781 #define PNG_FP_MIN (-PNG_FP_MAX) 782 783 /* These describe the color_type field in png_info. */ 784 /* color type masks */ 785 #define PNG_COLOR_MASK_PALETTE 1 786 #define PNG_COLOR_MASK_COLOR 2 787 #define PNG_COLOR_MASK_ALPHA 4 788 789 /* color types. Note that not all combinations are legal */ 790 #define PNG_COLOR_TYPE_GRAY 0 791 #define PNG_COLOR_TYPE_PALETTE (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE) 792 #define PNG_COLOR_TYPE_RGB (PNG_COLOR_MASK_COLOR) 793 #define PNG_COLOR_TYPE_RGB_ALPHA (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_ALPHA) 794 #define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA) 795 /* aliases */ 796 #define PNG_COLOR_TYPE_RGBA PNG_COLOR_TYPE_RGB_ALPHA 797 #define PNG_COLOR_TYPE_GA PNG_COLOR_TYPE_GRAY_ALPHA 798 799 /* This is for compression type. PNG 1.0-1.2 only define the single type. */ 800 #define PNG_COMPRESSION_TYPE_BASE 0 /* Deflate method 8, 32K window */ 801 #define PNG_COMPRESSION_TYPE_DEFAULT PNG_COMPRESSION_TYPE_BASE 802 803 /* This is for filter type. PNG 1.0-1.2 only define the single type. */ 804 #define PNG_FILTER_TYPE_BASE 0 /* Single row per-byte filtering */ 805 #define PNG_INTRAPIXEL_DIFFERENCING 64 /* Used only in MNG datastreams */ 806 #define PNG_FILTER_TYPE_DEFAULT PNG_FILTER_TYPE_BASE 807 808 /* These are for the interlacing type. These values should NOT be changed. */ 809 #define PNG_INTERLACE_NONE 0 /* Non-interlaced image */ 810 #define PNG_INTERLACE_ADAM7 1 /* Adam7 interlacing */ 811 #define PNG_INTERLACE_LAST 2 /* Not a valid value */ 812 813 /* These are for the oFFs chunk. These values should NOT be changed. */ 814 #define PNG_OFFSET_PIXEL 0 /* Offset in pixels */ 815 #define PNG_OFFSET_MICROMETER 1 /* Offset in micrometers (1/10^6 meter) */ 816 #define PNG_OFFSET_LAST 2 /* Not a valid value */ 817 818 /* These are for the pCAL chunk. These values should NOT be changed. */ 819 #define PNG_EQUATION_LINEAR 0 /* Linear transformation */ 820 #define PNG_EQUATION_BASE_E 1 /* Exponential base e transform */ 821 #define PNG_EQUATION_ARBITRARY 2 /* Arbitrary base exponential transform */ 822 #define PNG_EQUATION_HYPERBOLIC 3 /* Hyperbolic sine transformation */ 823 #define PNG_EQUATION_LAST 4 /* Not a valid value */ 824 825 /* These are for the sCAL chunk. These values should NOT be changed. */ 826 #define PNG_SCALE_UNKNOWN 0 /* unknown unit (image scale) */ 827 #define PNG_SCALE_METER 1 /* meters per pixel */ 828 #define PNG_SCALE_RADIAN 2 /* radians per pixel */ 829 #define PNG_SCALE_LAST 3 /* Not a valid value */ 830 831 /* These are for the pHYs chunk. These values should NOT be changed. */ 832 #define PNG_RESOLUTION_UNKNOWN 0 /* pixels/unknown unit (aspect ratio) */ 833 #define PNG_RESOLUTION_METER 1 /* pixels/meter */ 834 #define PNG_RESOLUTION_LAST 2 /* Not a valid value */ 835 836 /* These are for the sRGB chunk. These values should NOT be changed. */ 837 #define PNG_sRGB_INTENT_PERCEPTUAL 0 838 #define PNG_sRGB_INTENT_RELATIVE 1 839 #define PNG_sRGB_INTENT_SATURATION 2 840 #define PNG_sRGB_INTENT_ABSOLUTE 3 841 #define PNG_sRGB_INTENT_LAST 4 /* Not a valid value */ 842 843 /* This is for text chunks */ 844 #define PNG_KEYWORD_MAX_LENGTH 79 845 846 /* Maximum number of entries in PLTE/sPLT/tRNS arrays */ 847 #define PNG_MAX_PALETTE_LENGTH 256 848 849 /* These determine if an ancillary chunk's data has been successfully read 850 * from the PNG header, or if the application has filled in the corresponding 851 * data in the info_struct to be written into the output file. The values 852 * of the PNG_INFO_<chunk> defines should NOT be changed. 853 */ 854 #define PNG_INFO_gAMA 0x0001 855 #define PNG_INFO_sBIT 0x0002 856 #define PNG_INFO_cHRM 0x0004 857 #define PNG_INFO_PLTE 0x0008 858 #define PNG_INFO_tRNS 0x0010 859 #define PNG_INFO_bKGD 0x0020 860 #define PNG_INFO_hIST 0x0040 861 #define PNG_INFO_pHYs 0x0080 862 #define PNG_INFO_oFFs 0x0100 863 #define PNG_INFO_tIME 0x0200 864 #define PNG_INFO_pCAL 0x0400 865 #define PNG_INFO_sRGB 0x0800 /* GR-P, 0.96a */ 866 #define PNG_INFO_iCCP 0x1000 /* ESR, 1.0.6 */ 867 #define PNG_INFO_sPLT 0x2000 /* ESR, 1.0.6 */ 868 #define PNG_INFO_sCAL 0x4000 /* ESR, 1.0.6 */ 869 #define PNG_INFO_IDAT 0x8000 /* ESR, 1.0.6 */ 870 871 /* This is used for the transformation routines, as some of them 872 * change these values for the row. It also should enable using 873 * the routines for other purposes. 874 */ 875 typedef struct png_row_info_struct 876 { 877 png_uint_32 width; /* width of row */ 878 png_size_t rowbytes; /* number of bytes in row */ 879 png_byte color_type; /* color type of row */ 880 png_byte bit_depth; /* bit depth of row */ 881 png_byte channels; /* number of channels (1, 2, 3, or 4) */ 882 png_byte pixel_depth; /* bits per pixel (depth * channels) */ 883 } png_row_info; 884 885 typedef png_row_info * png_row_infop; 886 typedef png_row_info * * png_row_infopp; 887 888 /* These are the function types for the I/O functions and for the functions 889 * that allow the user to override the default I/O functions with his or her 890 * own. The png_error_ptr type should match that of user-supplied warning 891 * and error functions, while the png_rw_ptr type should match that of the 892 * user read/write data functions. Note that the 'write' function must not 893 * modify the buffer it is passed. The 'read' function, on the other hand, is 894 * expected to return the read data in the buffer. 895 */ 896 typedef PNG_CALLBACK(void, *png_error_ptr, (png_structp, png_const_charp)); 897 typedef PNG_CALLBACK(void, *png_rw_ptr, (png_structp, png_bytep, png_size_t)); 898 typedef PNG_CALLBACK(void, *png_flush_ptr, (png_structp)); 899 typedef PNG_CALLBACK(void, *png_read_status_ptr, (png_structp, png_uint_32, 900 int)); 901 typedef PNG_CALLBACK(void, *png_write_status_ptr, (png_structp, png_uint_32, 902 int)); 903 904 #ifdef PNG_INDEX_SUPPORTED 905 typedef PNG_CALLBACK(void, *png_seek_ptr, (png_structp, png_uint_32)); 906 #endif 907 908 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED 909 typedef PNG_CALLBACK(void, *png_progressive_info_ptr, (png_structp, png_infop)); 910 typedef PNG_CALLBACK(void, *png_progressive_end_ptr, (png_structp, png_infop)); 911 912 /* The following callback receives png_uint_32 row_number, int pass for the 913 * png_bytep data of the row. When transforming an interlaced image the 914 * row number is the row number within the sub-image of the interlace pass, so 915 * the value will increase to the height of the sub-image (not the full image) 916 * then reset to 0 for the next pass. 917 * 918 * Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to 919 * find the output pixel (x,y) given an interlaced sub-image pixel 920 * (row,col,pass). (See below for these macros.) 921 */ 922 typedef PNG_CALLBACK(void, *png_progressive_row_ptr, (png_structp, png_bytep, 923 png_uint_32, int)); 924 #endif 925 926 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \ 927 defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) 928 typedef PNG_CALLBACK(void, *png_user_transform_ptr, (png_structp, png_row_infop, 929 png_bytep)); 930 #endif 931 932 #ifdef PNG_USER_CHUNKS_SUPPORTED 933 typedef PNG_CALLBACK(int, *png_user_chunk_ptr, (png_structp, 934 png_unknown_chunkp)); 935 #endif 936 #ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED 937 /* not used anywhere */ 938 /* typedef PNG_CALLBACK(void, *png_unknown_chunk_ptr, (png_structp)); */ 939 #endif 940 941 #ifdef PNG_SETJMP_SUPPORTED 942 /* This must match the function definition in <setjmp.h>, and the application 943 * must include this before png.h to obtain the definition of jmp_buf. The 944 * function is required to be PNG_NORETURN, but this is not checked. If the 945 * function does return the application will crash via an abort() or similar 946 * system level call. 947 * 948 * If you get a warning here while building the library you may need to make 949 * changes to ensure that pnglibconf.h records the calling convention used by 950 * your compiler. This may be very difficult - try using a different compiler 951 * to build the library! 952 */ 953 PNG_FUNCTION(void, (PNGCAPI *png_longjmp_ptr), PNGARG((jmp_buf, int)), typedef); 954 #endif 955 956 /* Transform masks for the high-level interface */ 957 #define PNG_TRANSFORM_IDENTITY 0x0000 /* read and write */ 958 #define PNG_TRANSFORM_STRIP_16 0x0001 /* read only */ 959 #define PNG_TRANSFORM_STRIP_ALPHA 0x0002 /* read only */ 960 #define PNG_TRANSFORM_PACKING 0x0004 /* read and write */ 961 #define PNG_TRANSFORM_PACKSWAP 0x0008 /* read and write */ 962 #define PNG_TRANSFORM_EXPAND 0x0010 /* read only */ 963 #define PNG_TRANSFORM_INVERT_MONO 0x0020 /* read and write */ 964 #define PNG_TRANSFORM_SHIFT 0x0040 /* read and write */ 965 #define PNG_TRANSFORM_BGR 0x0080 /* read and write */ 966 #define PNG_TRANSFORM_SWAP_ALPHA 0x0100 /* read and write */ 967 #define PNG_TRANSFORM_SWAP_ENDIAN 0x0200 /* read and write */ 968 #define PNG_TRANSFORM_INVERT_ALPHA 0x0400 /* read and write */ 969 #define PNG_TRANSFORM_STRIP_FILLER 0x0800 /* write only */ 970 /* Added to libpng-1.2.34 */ 971 #define PNG_TRANSFORM_STRIP_FILLER_BEFORE PNG_TRANSFORM_STRIP_FILLER 972 #define PNG_TRANSFORM_STRIP_FILLER_AFTER 0x1000 /* write only */ 973 /* Added to libpng-1.4.0 */ 974 #define PNG_TRANSFORM_GRAY_TO_RGB 0x2000 /* read only */ 975 /* Added to libpng-1.5.4 */ 976 #define PNG_TRANSFORM_EXPAND_16 0x4000 /* read only */ 977 #define PNG_TRANSFORM_SCALE_16 0x8000 /* read only */ 978 979 /* Flags for MNG supported features */ 980 #define PNG_FLAG_MNG_EMPTY_PLTE 0x01 981 #define PNG_FLAG_MNG_FILTER_64 0x04 982 #define PNG_ALL_MNG_FEATURES 0x05 983 984 /* NOTE: prior to 1.5 these functions had no 'API' style declaration, 985 * this allowed the zlib default functions to be used on Windows 986 * platforms. In 1.5 the zlib default malloc (which just calls malloc and 987 * ignores the first argument) should be completely compatible with the 988 * following. 989 */ 990 typedef PNG_CALLBACK(png_voidp, *png_malloc_ptr, (png_structp, 991 png_alloc_size_t)); 992 typedef PNG_CALLBACK(void, *png_free_ptr, (png_structp, png_voidp)); 993 994 /* Section 3: exported functions 995 * Here are the function definitions most commonly used. This is not 996 * the place to find out how to use libpng. See libpng-manual.txt for the 997 * full explanation, see example.c for the summary. This just provides 998 * a simple one line description of the use of each function. 999 * 1000 * The PNG_EXPORT() and PNG_EXPORTA() macros used below are defined in 1001 * pngconf.h and in the *.dfn files in the scripts directory. 1002 * 1003 * PNG_EXPORT(ordinal, type, name, (args)); 1004 * 1005 * ordinal: ordinal that is used while building 1006 * *.def files. The ordinal value is only 1007 * relevant when preprocessing png.h with 1008 * the *.dfn files for building symbol table 1009 * entries, and are removed by pngconf.h. 1010 * type: return type of the function 1011 * name: function name 1012 * args: function arguments, with types 1013 * 1014 * When we wish to append attributes to a function prototype we use 1015 * the PNG_EXPORTA() macro instead. 1016 * 1017 * PNG_EXPORTA(ordinal, type, name, (args), attributes); 1018 * 1019 * ordinal, type, name, and args: same as in PNG_EXPORT(). 1020 * attributes: function attributes 1021 */ 1022 1023 /* Returns the version number of the library */ 1024 PNG_EXPORT(1, png_uint_32, png_access_version_number, (void)); 1025 1026 /* Tell lib we have already handled the first <num_bytes> magic bytes. 1027 * Handling more than 8 bytes from the beginning of the file is an error. 1028 */ 1029 PNG_EXPORT(2, void, png_set_sig_bytes, (png_structrp png_ptr, int num_bytes)); 1030 1031 /* Check sig[start] through sig[start + num_to_check - 1] to see if it's a 1032 * PNG file. Returns zero if the supplied bytes match the 8-byte PNG 1033 * signature, and non-zero otherwise. Having num_to_check == 0 or 1034 * start > 7 will always fail (ie return non-zero). 1035 */ 1036 PNG_EXPORT(3, int, png_sig_cmp, (png_const_bytep sig, png_size_t start, 1037 png_size_t num_to_check)); 1038 1039 /* Simple signature checking function. This is the same as calling 1040 * png_check_sig(sig, n) := !png_sig_cmp(sig, 0, n). 1041 */ 1042 #define png_check_sig(sig, n) !png_sig_cmp((sig), 0, (n)) 1043 1044 /* Allocate and initialize png_ptr struct for reading, and any other memory. */ 1045 PNG_EXPORTA(4, png_structp, png_create_read_struct, 1046 (png_const_charp user_png_ver, png_voidp error_ptr, 1047 png_error_ptr error_fn, png_error_ptr warn_fn), 1048 PNG_ALLOCATED); 1049 1050 /* Allocate and initialize png_ptr struct for writing, and any other memory */ 1051 PNG_EXPORTA(5, png_structp, png_create_write_struct, 1052 (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn, 1053 png_error_ptr warn_fn), 1054 PNG_ALLOCATED); 1055 1056 PNG_EXPORT(6, png_size_t, png_get_compression_buffer_size, 1057 (png_const_structrp png_ptr)); 1058 1059 PNG_EXPORT(7, void, png_set_compression_buffer_size, (png_structrp png_ptr, 1060 png_size_t size)); 1061 1062 /* Moved from pngconf.h in 1.4.0 and modified to ensure setjmp/longjmp 1063 * match up. 1064 */ 1065 #ifdef PNG_SETJMP_SUPPORTED 1066 /* This function returns the jmp_buf built in to *png_ptr. It must be 1067 * supplied with an appropriate 'longjmp' function to use on that jmp_buf 1068 * unless the default error function is overridden in which case NULL is 1069 * acceptable. The size of the jmp_buf is checked against the actual size 1070 * allocated by the library - the call will return NULL on a mismatch 1071 * indicating an ABI mismatch. 1072 */ 1073 PNG_EXPORT(8, jmp_buf*, png_set_longjmp_fn, (png_structrp png_ptr, 1074 png_longjmp_ptr longjmp_fn, size_t jmp_buf_size)); 1075 # define png_jmpbuf(png_ptr) \ 1076 (*png_set_longjmp_fn((png_ptr), longjmp, (sizeof (jmp_buf)))) 1077 #else 1078 # define png_jmpbuf(png_ptr) \ 1079 (LIBPNG_WAS_COMPILED_WITH__PNG_NO_SETJMP) 1080 #endif 1081 /* This function should be used by libpng applications in place of 1082 * longjmp(png_ptr->jmpbuf, val). If longjmp_fn() has been set, it 1083 * will use it; otherwise it will call PNG_ABORT(). This function was 1084 * added in libpng-1.5.0. 1085 */ 1086 PNG_EXPORTA(9, void, png_longjmp, (png_const_structrp png_ptr, int val), 1087 PNG_NORETURN); 1088 1089 #ifdef PNG_READ_SUPPORTED 1090 /* Reset the compression stream */ 1091 PNG_EXPORTA(10, int, png_reset_zstream, (png_structrp png_ptr), PNG_DEPRECATED); 1092 #endif 1093 1094 /* New functions added in libpng-1.0.2 (not enabled by default until 1.2.0) */ 1095 #ifdef PNG_USER_MEM_SUPPORTED 1096 PNG_EXPORTA(11, png_structp, png_create_read_struct_2, 1097 (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn, 1098 png_error_ptr warn_fn, 1099 png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn), 1100 PNG_ALLOCATED); 1101 PNG_EXPORTA(12, png_structp, png_create_write_struct_2, 1102 (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn, 1103 png_error_ptr warn_fn, 1104 png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn), 1105 PNG_ALLOCATED); 1106 #endif 1107 1108 /* Write the PNG file signature. */ 1109 PNG_EXPORT(13, void, png_write_sig, (png_structrp png_ptr)); 1110 1111 /* Write a PNG chunk - size, type, (optional) data, CRC. */ 1112 PNG_EXPORT(14, void, png_write_chunk, (png_structrp png_ptr, png_const_bytep 1113 chunk_name, png_const_bytep data, png_size_t length)); 1114 1115 /* Write the start of a PNG chunk - length and chunk name. */ 1116 PNG_EXPORT(15, void, png_write_chunk_start, (png_structrp png_ptr, 1117 png_const_bytep chunk_name, png_uint_32 length)); 1118 1119 /* Write the data of a PNG chunk started with png_write_chunk_start(). */ 1120 PNG_EXPORT(16, void, png_write_chunk_data, (png_structrp png_ptr, 1121 png_const_bytep data, png_size_t length)); 1122 1123 /* Finish a chunk started with png_write_chunk_start() (includes CRC). */ 1124 PNG_EXPORT(17, void, png_write_chunk_end, (png_structrp png_ptr)); 1125 1126 /* Allocate and initialize the info structure */ 1127 PNG_EXPORTA(18, png_infop, png_create_info_struct, (png_const_structrp png_ptr), 1128 PNG_ALLOCATED); 1129 1130 /* DEPRECATED: this function allowed init structures to be created using the 1131 * default allocation method (typically malloc). Use is deprecated in 1.6.0 and 1132 * the API will be removed in the future. 1133 */ 1134 PNG_EXPORTA(19, void, png_info_init_3, (png_infopp info_ptr, 1135 png_size_t png_info_struct_size), PNG_DEPRECATED); 1136 1137 /* Writes all the PNG information before the image. */ 1138 PNG_EXPORT(20, void, png_write_info_before_PLTE, 1139 (png_structrp png_ptr, png_const_inforp info_ptr)); 1140 PNG_EXPORT(21, void, png_write_info, 1141 (png_structrp png_ptr, png_const_inforp info_ptr)); 1142 1143 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED 1144 /* Read the information before the actual image data. */ 1145 PNG_EXPORT(22, void, png_read_info, 1146 (png_structrp png_ptr, png_inforp info_ptr)); 1147 #endif 1148 1149 #ifdef PNG_TIME_RFC1123_SUPPORTED 1150 /* Convert to a US string format: there is no localization support in this 1151 * routine. The original implementation used a 29 character buffer in 1152 * png_struct, this will be removed in future versions. 1153 */ 1154 #if PNG_LIBPNG_VER < 10700 1155 /* To do: remove this from libpng17 (and from libpng17/png.c and pngstruct.h) */ 1156 PNG_EXPORTA(23, png_const_charp, png_convert_to_rfc1123, (png_structrp png_ptr, 1157 png_const_timep ptime),PNG_DEPRECATED); 1158 #endif 1159 PNG_EXPORT(241, int, png_convert_to_rfc1123_buffer, (char out[29], 1160 png_const_timep ptime)); 1161 #endif 1162 1163 #ifdef PNG_CONVERT_tIME_SUPPORTED 1164 /* Convert from a struct tm to png_time */ 1165 PNG_EXPORT(24, void, png_convert_from_struct_tm, (png_timep ptime, 1166 const struct tm * ttime)); 1167 1168 /* Convert from time_t to png_time. Uses gmtime() */ 1169 PNG_EXPORT(25, void, png_convert_from_time_t, (png_timep ptime, time_t ttime)); 1170 #endif /* PNG_CONVERT_tIME_SUPPORTED */ 1171 1172 #ifdef PNG_READ_EXPAND_SUPPORTED 1173 /* Expand data to 24-bit RGB, or 8-bit grayscale, with alpha if available. */ 1174 PNG_EXPORT(26, void, png_set_expand, (png_structrp png_ptr)); 1175 PNG_EXPORT(27, void, png_set_expand_gray_1_2_4_to_8, (png_structrp png_ptr)); 1176 PNG_EXPORT(28, void, png_set_palette_to_rgb, (png_structrp png_ptr)); 1177 PNG_EXPORT(29, void, png_set_tRNS_to_alpha, (png_structrp png_ptr)); 1178 #endif 1179 1180 #ifdef PNG_READ_EXPAND_16_SUPPORTED 1181 /* Expand to 16-bit channels, forces conversion of palette to RGB and expansion 1182 * of a tRNS chunk if present. 1183 */ 1184 PNG_EXPORT(221, void, png_set_expand_16, (png_structrp png_ptr)); 1185 #endif 1186 1187 #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED) 1188 /* Use blue, green, red order for pixels. */ 1189 PNG_EXPORT(30, void, png_set_bgr, (png_structrp png_ptr)); 1190 #endif 1191 1192 #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED 1193 /* Expand the grayscale to 24-bit RGB if necessary. */ 1194 PNG_EXPORT(31, void, png_set_gray_to_rgb, (png_structrp png_ptr)); 1195 #endif 1196 1197 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED 1198 /* Reduce RGB to grayscale. */ 1199 #define PNG_ERROR_ACTION_NONE 1 1200 #define PNG_ERROR_ACTION_WARN 2 1201 #define PNG_ERROR_ACTION_ERROR 3 1202 #define PNG_RGB_TO_GRAY_DEFAULT (-1)/*for red/green coefficients*/ 1203 1204 PNG_FP_EXPORT(32, void, png_set_rgb_to_gray, (png_structrp png_ptr, 1205 int error_action, double red, double green)) 1206 PNG_FIXED_EXPORT(33, void, png_set_rgb_to_gray_fixed, (png_structrp png_ptr, 1207 int error_action, png_fixed_point red, png_fixed_point green)) 1208 1209 PNG_EXPORT(34, png_byte, png_get_rgb_to_gray_status, (png_const_structrp 1210 png_ptr)); 1211 #endif 1212 1213 #ifdef PNG_BUILD_GRAYSCALE_PALETTE_SUPPORTED 1214 PNG_EXPORT(35, void, png_build_grayscale_palette, (int bit_depth, 1215 png_colorp palette)); 1216 #endif 1217 1218 #ifdef PNG_READ_ALPHA_MODE_SUPPORTED 1219 /* How the alpha channel is interpreted - this affects how the color channels 1220 * of a PNG file are returned to the calling application when an alpha channel, 1221 * or a tRNS chunk in a palette file, is present. 1222 * 1223 * This has no effect on the way pixels are written into a PNG output 1224 * datastream. The color samples in a PNG datastream are never premultiplied 1225 * with the alpha samples. 1226 * 1227 * The default is to return data according to the PNG specification: the alpha 1228 * channel is a linear measure of the contribution of the pixel to the 1229 * corresponding composited pixel, and the color channels are unassociated 1230 * (not premultiplied). The gamma encoded color channels must be scaled 1231 * according to the contribution and to do this it is necessary to undo 1232 * the encoding, scale the color values, perform the composition and reencode 1233 * the values. This is the 'PNG' mode. 1234 * 1235 * The alternative is to 'associate' the alpha with the color information by 1236 * storing color channel values that have been scaled by the alpha. 1237 * image. These are the 'STANDARD', 'ASSOCIATED' or 'PREMULTIPLIED' modes 1238 * (the latter being the two common names for associated alpha color channels). 1239 * 1240 * For the 'OPTIMIZED' mode, a pixel is treated as opaque only if the alpha 1241 * value is equal to the maximum value. 1242 * 1243 * The final choice is to gamma encode the alpha channel as well. This is 1244 * broken because, in practice, no implementation that uses this choice 1245 * correctly undoes the encoding before handling alpha composition. Use this 1246 * choice only if other serious errors in the software or hardware you use 1247 * mandate it; the typical serious error is for dark halos to appear around 1248 * opaque areas of the composited PNG image because of arithmetic overflow. 1249 * 1250 * The API function png_set_alpha_mode specifies which of these choices to use 1251 * with an enumerated 'mode' value and the gamma of the required output: 1252 */ 1253 #define PNG_ALPHA_PNG 0 /* according to the PNG standard */ 1254 #define PNG_ALPHA_STANDARD 1 /* according to Porter/Duff */ 1255 #define PNG_ALPHA_ASSOCIATED 1 /* as above; this is the normal practice */ 1256 #define PNG_ALPHA_PREMULTIPLIED 1 /* as above */ 1257 #define PNG_ALPHA_OPTIMIZED 2 /* 'PNG' for opaque pixels, else 'STANDARD' */ 1258 #define PNG_ALPHA_BROKEN 3 /* the alpha channel is gamma encoded */ 1259 1260 PNG_FP_EXPORT(227, void, png_set_alpha_mode, (png_structrp png_ptr, int mode, 1261 double output_gamma)) 1262 PNG_FIXED_EXPORT(228, void, png_set_alpha_mode_fixed, (png_structrp png_ptr, 1263 int mode, png_fixed_point output_gamma)) 1264 #endif 1265 1266 #if defined(PNG_GAMMA_SUPPORTED) || defined(PNG_READ_ALPHA_MODE_SUPPORTED) 1267 /* The output_gamma value is a screen gamma in libpng terminology: it expresses 1268 * how to decode the output values, not how they are encoded. 1269 */ 1270 #define PNG_DEFAULT_sRGB -1 /* sRGB gamma and color space */ 1271 #define PNG_GAMMA_MAC_18 -2 /* Old Mac '1.8' gamma and color space */ 1272 #define PNG_GAMMA_sRGB 220000 /* Television standards--matches sRGB gamma */ 1273 #define PNG_GAMMA_LINEAR PNG_FP_1 /* Linear */ 1274 #endif 1275 1276 /* The following are examples of calls to png_set_alpha_mode to achieve the 1277 * required overall gamma correction and, where necessary, alpha 1278 * premultiplication. 1279 * 1280 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB); 1281 * This is the default libpng handling of the alpha channel - it is not 1282 * pre-multiplied into the color components. In addition the call states 1283 * that the output is for a sRGB system and causes all PNG files without gAMA 1284 * chunks to be assumed to be encoded using sRGB. 1285 * 1286 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC); 1287 * In this case the output is assumed to be something like an sRGB conformant 1288 * display preceeded by a power-law lookup table of power 1.45. This is how 1289 * early Mac systems behaved. 1290 * 1291 * png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_GAMMA_LINEAR); 1292 * This is the classic Jim Blinn approach and will work in academic 1293 * environments where everything is done by the book. It has the shortcoming 1294 * of assuming that input PNG data with no gamma information is linear - this 1295 * is unlikely to be correct unless the PNG files where generated locally. 1296 * Most of the time the output precision will be so low as to show 1297 * significant banding in dark areas of the image. 1298 * 1299 * png_set_expand_16(pp); 1300 * png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_DEFAULT_sRGB); 1301 * This is a somewhat more realistic Jim Blinn inspired approach. PNG files 1302 * are assumed to have the sRGB encoding if not marked with a gamma value and 1303 * the output is always 16 bits per component. This permits accurate scaling 1304 * and processing of the data. If you know that your input PNG files were 1305 * generated locally you might need to replace PNG_DEFAULT_sRGB with the 1306 * correct value for your system. 1307 * 1308 * png_set_alpha_mode(pp, PNG_ALPHA_OPTIMIZED, PNG_DEFAULT_sRGB); 1309 * If you just need to composite the PNG image onto an existing background 1310 * and if you control the code that does this you can use the optimization 1311 * setting. In this case you just copy completely opaque pixels to the 1312 * output. For pixels that are not completely transparent (you just skip 1313 * those) you do the composition math using png_composite or png_composite_16 1314 * below then encode the resultant 8-bit or 16-bit values to match the output 1315 * encoding. 1316 * 1317 * Other cases 1318 * If neither the PNG nor the standard linear encoding work for you because 1319 * of the software or hardware you use then you have a big problem. The PNG 1320 * case will probably result in halos around the image. The linear encoding 1321 * will probably result in a washed out, too bright, image (it's actually too 1322 * contrasty.) Try the ALPHA_OPTIMIZED mode above - this will probably 1323 * substantially reduce the halos. Alternatively try: 1324 * 1325 * png_set_alpha_mode(pp, PNG_ALPHA_BROKEN, PNG_DEFAULT_sRGB); 1326 * This option will also reduce the halos, but there will be slight dark 1327 * halos round the opaque parts of the image where the background is light. 1328 * In the OPTIMIZED mode the halos will be light halos where the background 1329 * is dark. Take your pick - the halos are unavoidable unless you can get 1330 * your hardware/software fixed! (The OPTIMIZED approach is slightly 1331 * faster.) 1332 * 1333 * When the default gamma of PNG files doesn't match the output gamma. 1334 * If you have PNG files with no gamma information png_set_alpha_mode allows 1335 * you to provide a default gamma, but it also sets the ouput gamma to the 1336 * matching value. If you know your PNG files have a gamma that doesn't 1337 * match the output you can take advantage of the fact that 1338 * png_set_alpha_mode always sets the output gamma but only sets the PNG 1339 * default if it is not already set: 1340 * 1341 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB); 1342 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC); 1343 * The first call sets both the default and the output gamma values, the 1344 * second call overrides the output gamma without changing the default. This 1345 * is easier than achieving the same effect with png_set_gamma. You must use 1346 * PNG_ALPHA_PNG for the first call - internal checking in png_set_alpha will 1347 * fire if more than one call to png_set_alpha_mode and png_set_background is 1348 * made in the same read operation, however multiple calls with PNG_ALPHA_PNG 1349 * are ignored. 1350 */ 1351 1352 #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED 1353 PNG_EXPORT(36, void, png_set_strip_alpha, (png_structrp png_ptr)); 1354 #endif 1355 1356 #if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \ 1357 defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED) 1358 PNG_EXPORT(37, void, png_set_swap_alpha, (png_structrp png_ptr)); 1359 #endif 1360 1361 #if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \ 1362 defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED) 1363 PNG_EXPORT(38, void, png_set_invert_alpha, (png_structrp png_ptr)); 1364 #endif 1365 1366 #if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED) 1367 /* Add a filler byte to 8-bit Gray or 24-bit RGB images. */ 1368 PNG_EXPORT(39, void, png_set_filler, (png_structrp png_ptr, png_uint_32 filler, 1369 int flags)); 1370 /* The values of the PNG_FILLER_ defines should NOT be changed */ 1371 # define PNG_FILLER_BEFORE 0 1372 # define PNG_FILLER_AFTER 1 1373 /* Add an alpha byte to 8-bit Gray or 24-bit RGB images. */ 1374 PNG_EXPORT(40, void, png_set_add_alpha, (png_structrp png_ptr, 1375 png_uint_32 filler, int flags)); 1376 #endif /* PNG_READ_FILLER_SUPPORTED || PNG_WRITE_FILLER_SUPPORTED */ 1377 1378 #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED) 1379 /* Swap bytes in 16-bit depth files. */ 1380 PNG_EXPORT(41, void, png_set_swap, (png_structrp png_ptr)); 1381 #endif 1382 1383 #if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED) 1384 /* Use 1 byte per pixel in 1, 2, or 4-bit depth files. */ 1385 PNG_EXPORT(42, void, png_set_packing, (png_structrp png_ptr)); 1386 #endif 1387 1388 #if defined(PNG_READ_PACKSWAP_SUPPORTED) || \ 1389 defined(PNG_WRITE_PACKSWAP_SUPPORTED) 1390 /* Swap packing order of pixels in bytes. */ 1391 PNG_EXPORT(43, void, png_set_packswap, (png_structrp png_ptr)); 1392 #endif 1393 1394 #if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED) 1395 /* Converts files to legal bit depths. */ 1396 PNG_EXPORT(44, void, png_set_shift, (png_structrp png_ptr, png_const_color_8p 1397 true_bits)); 1398 #endif 1399 1400 #if defined(PNG_READ_INTERLACING_SUPPORTED) || \ 1401 defined(PNG_WRITE_INTERLACING_SUPPORTED) 1402 /* Have the code handle the interlacing. Returns the number of passes. 1403 * MUST be called before png_read_update_info or png_start_read_image, 1404 * otherwise it will not have the desired effect. Note that it is still 1405 * necessary to call png_read_row or png_read_rows png_get_image_height 1406 * times for each pass. 1407 */ 1408 PNG_EXPORT(45, int, png_set_interlace_handling, (png_structrp png_ptr)); 1409 #endif 1410 1411 #if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED) 1412 /* Invert monochrome files */ 1413 PNG_EXPORT(46, void, png_set_invert_mono, (png_structrp png_ptr)); 1414 #endif 1415 1416 #ifdef PNG_READ_BACKGROUND_SUPPORTED 1417 /* Handle alpha and tRNS by replacing with a background color. Prior to 1418 * libpng-1.5.4 this API must not be called before the PNG file header has been 1419 * read. Doing so will result in unexpected behavior and possible warnings or 1420 * errors if the PNG file contains a bKGD chunk. 1421 */ 1422 PNG_FP_EXPORT(47, void, png_set_background, (png_structrp png_ptr, 1423 png_const_color_16p background_color, int background_gamma_code, 1424 int need_expand, double background_gamma)) 1425 PNG_FIXED_EXPORT(215, void, png_set_background_fixed, (png_structrp png_ptr, 1426 png_const_color_16p background_color, int background_gamma_code, 1427 int need_expand, png_fixed_point background_gamma)) 1428 #endif 1429 #ifdef PNG_READ_BACKGROUND_SUPPORTED 1430 # define PNG_BACKGROUND_GAMMA_UNKNOWN 0 1431 # define PNG_BACKGROUND_GAMMA_SCREEN 1 1432 # define PNG_BACKGROUND_GAMMA_FILE 2 1433 # define PNG_BACKGROUND_GAMMA_UNIQUE 3 1434 #endif 1435 1436 #ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED 1437 /* Scale a 16-bit depth file down to 8-bit, accurately. */ 1438 PNG_EXPORT(229, void, png_set_scale_16, (png_structrp png_ptr)); 1439 #endif 1440 1441 #ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED 1442 #define PNG_READ_16_TO_8 SUPPORTED /* Name prior to 1.5.4 */ 1443 /* Strip the second byte of information from a 16-bit depth file. */ 1444 PNG_EXPORT(48, void, png_set_strip_16, (png_structrp png_ptr)); 1445 #endif 1446 1447 #ifdef PNG_READ_QUANTIZE_SUPPORTED 1448 /* Turn on quantizing, and reduce the palette to the number of colors 1449 * available. 1450 */ 1451 PNG_EXPORT(49, void, png_set_quantize, (png_structrp png_ptr, 1452 png_colorp palette, int num_palette, int maximum_colors, 1453 png_const_uint_16p histogram, int full_quantize)); 1454 #endif 1455 1456 #ifdef PNG_READ_GAMMA_SUPPORTED 1457 /* The threshold on gamma processing is configurable but hard-wired into the 1458 * library. The following is the floating point variant. 1459 */ 1460 #define PNG_GAMMA_THRESHOLD (PNG_GAMMA_THRESHOLD_FIXED*.00001) 1461 1462 /* Handle gamma correction. Screen_gamma=(display_exponent). 1463 * NOTE: this API simply sets the screen and file gamma values. It will 1464 * therefore override the value for gamma in a PNG file if it is called after 1465 * the file header has been read - use with care - call before reading the PNG 1466 * file for best results! 1467 * 1468 * These routines accept the same gamma values as png_set_alpha_mode (described 1469 * above). The PNG_GAMMA_ defines and PNG_DEFAULT_sRGB can be passed to either 1470 * API (floating point or fixed.) Notice, however, that the 'file_gamma' value 1471 * is the inverse of a 'screen gamma' value. 1472 */ 1473 PNG_FP_EXPORT(50, void, png_set_gamma, (png_structrp png_ptr, 1474 double screen_gamma, double override_file_gamma)) 1475 PNG_FIXED_EXPORT(208, void, png_set_gamma_fixed, (png_structrp png_ptr, 1476 png_fixed_point screen_gamma, png_fixed_point override_file_gamma)) 1477 #endif 1478 1479 #ifdef PNG_WRITE_FLUSH_SUPPORTED 1480 /* Set how many lines between output flushes - 0 for no flushing */ 1481 PNG_EXPORT(51, void, png_set_flush, (png_structrp png_ptr, int nrows)); 1482 /* Flush the current PNG output buffer */ 1483 PNG_EXPORT(52, void, png_write_flush, (png_structrp png_ptr)); 1484 #endif 1485 1486 /* Optional update palette with requested transformations */ 1487 PNG_EXPORT(53, void, png_start_read_image, (png_structrp png_ptr)); 1488 1489 /* Optional call to update the users info structure */ 1490 PNG_EXPORT(54, void, png_read_update_info, (png_structrp png_ptr, 1491 png_inforp info_ptr)); 1492 1493 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED 1494 /* Read one or more rows of image data. */ 1495 PNG_EXPORT(55, void, png_read_rows, (png_structrp png_ptr, png_bytepp row, 1496 png_bytepp display_row, png_uint_32 num_rows)); 1497 #endif 1498 1499 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED 1500 /* Read a row of data. */ 1501 PNG_EXPORT(56, void, png_read_row, (png_structrp png_ptr, png_bytep row, 1502 png_bytep display_row)); 1503 #endif 1504 1505 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED 1506 /* Read the whole image into memory at once. */ 1507 PNG_EXPORT(57, void, png_read_image, (png_structrp png_ptr, png_bytepp image)); 1508 #endif 1509 1510 /* Write a row of image data */ 1511 PNG_EXPORT(58, void, png_write_row, (png_structrp png_ptr, 1512 png_const_bytep row)); 1513 1514 /* Write a few rows of image data: (*row) is not written; however, the type 1515 * is declared as writeable to maintain compatibility with previous versions 1516 * of libpng and to allow the 'display_row' array from read_rows to be passed 1517 * unchanged to write_rows. 1518 */ 1519 PNG_EXPORT(59, void, png_write_rows, (png_structrp png_ptr, png_bytepp row, 1520 png_uint_32 num_rows)); 1521 1522 /* Write the image data */ 1523 PNG_EXPORT(60, void, png_write_image, (png_structrp png_ptr, png_bytepp image)); 1524 1525 /* Write the end of the PNG file. */ 1526 PNG_EXPORT(61, void, png_write_end, (png_structrp png_ptr, 1527 png_inforp info_ptr)); 1528 1529 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED 1530 /* Read the end of the PNG file. */ 1531 PNG_EXPORT(62, void, png_read_end, (png_structrp png_ptr, png_inforp info_ptr)); 1532 #endif 1533 1534 /* Free any memory associated with the png_info_struct */ 1535 PNG_EXPORT(63, void, png_destroy_info_struct, (png_const_structrp png_ptr, 1536 png_infopp info_ptr_ptr)); 1537 1538 /* Free any memory associated with the png_struct and the png_info_structs */ 1539 PNG_EXPORT(64, void, png_destroy_read_struct, (png_structpp png_ptr_ptr, 1540 png_infopp info_ptr_ptr, png_infopp end_info_ptr_ptr)); 1541 1542 /* Free any memory associated with the png_struct and the png_info_structs */ 1543 PNG_EXPORT(65, void, png_destroy_write_struct, (png_structpp png_ptr_ptr, 1544 png_infopp info_ptr_ptr)); 1545 1546 /* Set the libpng method of handling chunk CRC errors */ 1547 PNG_EXPORT(66, void, png_set_crc_action, (png_structrp png_ptr, int crit_action, 1548 int ancil_action)); 1549 1550 /* Values for png_set_crc_action() say how to handle CRC errors in 1551 * ancillary and critical chunks, and whether to use the data contained 1552 * therein. Note that it is impossible to "discard" data in a critical 1553 * chunk. For versions prior to 0.90, the action was always error/quit, 1554 * whereas in version 0.90 and later, the action for CRC errors in ancillary 1555 * chunks is warn/discard. These values should NOT be changed. 1556 * 1557 * value action:critical action:ancillary 1558 */ 1559 #define PNG_CRC_DEFAULT 0 /* error/quit warn/discard data */ 1560 #define PNG_CRC_ERROR_QUIT 1 /* error/quit error/quit */ 1561 #define PNG_CRC_WARN_DISCARD 2 /* (INVALID) warn/discard data */ 1562 #define PNG_CRC_WARN_USE 3 /* warn/use data warn/use data */ 1563 #define PNG_CRC_QUIET_USE 4 /* quiet/use data quiet/use data */ 1564 #define PNG_CRC_NO_CHANGE 5 /* use current value use current value */ 1565 1566 /* These functions give the user control over the scan-line filtering in 1567 * libpng and the compression methods used by zlib. These functions are 1568 * mainly useful for testing, as the defaults should work with most users. 1569 * Those users who are tight on memory or want faster performance at the 1570 * expense of compression can modify them. See the compression library 1571 * header file (zlib.h) for an explination of the compression functions. 1572 */ 1573 1574 /* Set the filtering method(s) used by libpng. Currently, the only valid 1575 * value for "method" is 0. 1576 */ 1577 PNG_EXPORT(67, void, png_set_filter, (png_structrp png_ptr, int method, 1578 int filters)); 1579 1580 /* Flags for png_set_filter() to say which filters to use. The flags 1581 * are chosen so that they don't conflict with real filter types 1582 * below, in case they are supplied instead of the #defined constants. 1583 * These values should NOT be changed. 1584 */ 1585 #define PNG_NO_FILTERS 0x00 1586 #define PNG_FILTER_NONE 0x08 1587 #define PNG_FILTER_SUB 0x10 1588 #define PNG_FILTER_UP 0x20 1589 #define PNG_FILTER_AVG 0x40 1590 #define PNG_FILTER_PAETH 0x80 1591 #define PNG_ALL_FILTERS (PNG_FILTER_NONE | PNG_FILTER_SUB | PNG_FILTER_UP | \ 1592 PNG_FILTER_AVG | PNG_FILTER_PAETH) 1593 1594 /* Filter values (not flags) - used in pngwrite.c, pngwutil.c for now. 1595 * These defines should NOT be changed. 1596 */ 1597 #define PNG_FILTER_VALUE_NONE 0 1598 #define PNG_FILTER_VALUE_SUB 1 1599 #define PNG_FILTER_VALUE_UP 2 1600 #define PNG_FILTER_VALUE_AVG 3 1601 #define PNG_FILTER_VALUE_PAETH 4 1602 #define PNG_FILTER_VALUE_LAST 5 1603 1604 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* EXPERIMENTAL */ 1605 /* The "heuristic_method" is given by one of the PNG_FILTER_HEURISTIC_ 1606 * defines, either the default (minimum-sum-of-absolute-differences), or 1607 * the experimental method (weighted-minimum-sum-of-absolute-differences). 1608 * 1609 * Weights are factors >= 1.0, indicating how important it is to keep the 1610 * filter type consistent between rows. Larger numbers mean the current 1611 * filter is that many times as likely to be the same as the "num_weights" 1612 * previous filters. This is cumulative for each previous row with a weight. 1613 * There needs to be "num_weights" values in "filter_weights", or it can be 1614 * NULL if the weights aren't being specified. Weights have no influence on 1615 * the selection of the first row filter. Well chosen weights can (in theory) 1616 * improve the compression for a given image. 1617 * 1618 * Costs are factors >= 1.0 indicating the relative decoding costs of a 1619 * filter type. Higher costs indicate more decoding expense, and are 1620 * therefore less likely to be selected over a filter with lower computational 1621 * costs. There needs to be a value in "filter_costs" for each valid filter 1622 * type (given by PNG_FILTER_VALUE_LAST), or it can be NULL if you aren't 1623 * setting the costs. Costs try to improve the speed of decompression without 1624 * unduly increasing the compressed image size. 1625 * 1626 * A negative weight or cost indicates the default value is to be used, and 1627 * values in the range [0.0, 1.0) indicate the value is to remain unchanged. 1628 * The default values for both weights and costs are currently 1.0, but may 1629 * change if good general weighting/cost heuristics can be found. If both 1630 * the weights and costs are set to 1.0, this degenerates the WEIGHTED method 1631 * to the UNWEIGHTED method, but with added encoding time/computation. 1632 */ 1633 PNG_FP_EXPORT(68, void, png_set_filter_heuristics, (png_structrp png_ptr, 1634 int heuristic_method, int num_weights, png_const_doublep filter_weights, 1635 png_const_doublep filter_costs)) 1636 PNG_FIXED_EXPORT(209, void, png_set_filter_heuristics_fixed, 1637 (png_structrp png_ptr, int heuristic_method, int num_weights, 1638 png_const_fixed_point_p filter_weights, 1639 png_const_fixed_point_p filter_costs)) 1640 #endif /* PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */ 1641 1642 /* Heuristic used for row filter selection. These defines should NOT be 1643 * changed. 1644 */ 1645 #define PNG_FILTER_HEURISTIC_DEFAULT 0 /* Currently "UNWEIGHTED" */ 1646 #define PNG_FILTER_HEURISTIC_UNWEIGHTED 1 /* Used by libpng < 0.95 */ 1647 #define PNG_FILTER_HEURISTIC_WEIGHTED 2 /* Experimental feature */ 1648 #define PNG_FILTER_HEURISTIC_LAST 3 /* Not a valid value */ 1649 1650 #ifdef PNG_WRITE_SUPPORTED 1651 /* Set the library compression level. Currently, valid values range from 1652 * 0 - 9, corresponding directly to the zlib compression levels 0 - 9 1653 * (0 - no compression, 9 - "maximal" compression). Note that tests have 1654 * shown that zlib compression levels 3-6 usually perform as well as level 9 1655 * for PNG images, and do considerably fewer caclulations. In the future, 1656 * these values may not correspond directly to the zlib compression levels. 1657 */ 1658 PNG_EXPORT(69, void, png_set_compression_level, (png_structrp png_ptr, 1659 int level)); 1660 1661 PNG_EXPORT(70, void, png_set_compression_mem_level, (png_structrp png_ptr, 1662 int mem_level)); 1663 1664 PNG_EXPORT(71, void, png_set_compression_strategy, (png_structrp png_ptr, 1665 int strategy)); 1666 1667 /* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a 1668 * smaller value of window_bits if it can do so safely. 1669 */ 1670 PNG_EXPORT(72, void, png_set_compression_window_bits, (png_structrp png_ptr, 1671 int window_bits)); 1672 1673 PNG_EXPORT(73, void, png_set_compression_method, (png_structrp png_ptr, 1674 int method)); 1675 #endif 1676 1677 #ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED 1678 /* Also set zlib parameters for compressing non-IDAT chunks */ 1679 PNG_EXPORT(222, void, png_set_text_compression_level, (png_structrp png_ptr, 1680 int level)); 1681 1682 PNG_EXPORT(223, void, png_set_text_compression_mem_level, (png_structrp png_ptr, 1683 int mem_level)); 1684 1685 PNG_EXPORT(224, void, png_set_text_compression_strategy, (png_structrp png_ptr, 1686 int strategy)); 1687 1688 /* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a 1689 * smaller value of window_bits if it can do so safely. 1690 */ 1691 PNG_EXPORT(225, void, png_set_text_compression_window_bits, 1692 (png_structrp png_ptr, int window_bits)); 1693 1694 PNG_EXPORT(226, void, png_set_text_compression_method, (png_structrp png_ptr, 1695 int method)); 1696 #endif /* PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED */ 1697 1698 /* These next functions are called for input/output, memory, and error 1699 * handling. They are in the file pngrio.c, pngwio.c, and pngerror.c, 1700 * and call standard C I/O routines such as fread(), fwrite(), and 1701 * fprintf(). These functions can be made to use other I/O routines 1702 * at run time for those applications that need to handle I/O in a 1703 * different manner by calling png_set_???_fn(). See libpng-manual.txt for 1704 * more information. 1705 */ 1706 1707 #ifdef PNG_STDIO_SUPPORTED 1708 /* Initialize the input/output for the PNG file to the default functions. */ 1709 PNG_EXPORT(74, void, png_init_io, (png_structrp png_ptr, png_FILE_p fp)); 1710 #endif 1711 1712 /* Replace the (error and abort), and warning functions with user 1713 * supplied functions. If no messages are to be printed you must still 1714 * write and use replacement functions. The replacement error_fn should 1715 * still do a longjmp to the last setjmp location if you are using this 1716 * method of error handling. If error_fn or warning_fn is NULL, the 1717 * default function will be used. 1718 */ 1719 1720 PNG_EXPORT(75, void, png_set_error_fn, (png_structrp png_ptr, 1721 png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warning_fn)); 1722 1723 /* Return the user pointer associated with the error functions */ 1724 PNG_EXPORT(76, png_voidp, png_get_error_ptr, (png_const_structrp png_ptr)); 1725 1726 /* Replace the default data output functions with a user supplied one(s). 1727 * If buffered output is not used, then output_flush_fn can be set to NULL. 1728 * If PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile time 1729 * output_flush_fn will be ignored (and thus can be NULL). 1730 * It is probably a mistake to use NULL for output_flush_fn if 1731 * write_data_fn is not also NULL unless you have built libpng with 1732 * PNG_WRITE_FLUSH_SUPPORTED undefined, because in this case libpng's 1733 * default flush function, which uses the standard *FILE structure, will 1734 * be used. 1735 */ 1736 PNG_EXPORT(77, void, png_set_write_fn, (png_structrp png_ptr, png_voidp io_ptr, 1737 png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn)); 1738 1739 /* Replace the default data input function with a user supplied one. */ 1740 PNG_EXPORT(78, void, png_set_read_fn, (png_structrp png_ptr, png_voidp io_ptr, 1741 png_rw_ptr read_data_fn)); 1742 1743 /* Return the user pointer associated with the I/O functions */ 1744 PNG_EXPORT(79, png_voidp, png_get_io_ptr, (png_const_structrp png_ptr)); 1745 1746 PNG_EXPORT(80, void, png_set_read_status_fn, (png_structrp png_ptr, 1747 png_read_status_ptr read_row_fn)); 1748 1749 PNG_EXPORT(81, void, png_set_write_status_fn, (png_structrp png_ptr, 1750 png_write_status_ptr write_row_fn)); 1751 1752 #ifdef PNG_USER_MEM_SUPPORTED 1753 /* Replace the default memory allocation functions with user supplied one(s). */ 1754 PNG_EXPORT(82, void, png_set_mem_fn, (png_structrp png_ptr, png_voidp mem_ptr, 1755 png_malloc_ptr malloc_fn, png_free_ptr free_fn)); 1756 /* Return the user pointer associated with the memory functions */ 1757 PNG_EXPORT(83, png_voidp, png_get_mem_ptr, (png_const_structrp png_ptr)); 1758 #endif 1759 1760 #ifdef PNG_READ_USER_TRANSFORM_SUPPORTED 1761 PNG_EXPORT(84, void, png_set_read_user_transform_fn, (png_structrp png_ptr, 1762 png_user_transform_ptr read_user_transform_fn)); 1763 #endif 1764 1765 #ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED 1766 PNG_EXPORT(85, void, png_set_write_user_transform_fn, (png_structrp png_ptr, 1767 png_user_transform_ptr write_user_transform_fn)); 1768 #endif 1769 1770 #ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED 1771 PNG_EXPORT(86, void, png_set_user_transform_info, (png_structrp png_ptr, 1772 png_voidp user_transform_ptr, int user_transform_depth, 1773 int user_transform_channels)); 1774 /* Return the user pointer associated with the user transform functions */ 1775 PNG_EXPORT(87, png_voidp, png_get_user_transform_ptr, 1776 (png_const_structrp png_ptr)); 1777 #endif 1778 1779 #ifdef PNG_USER_TRANSFORM_INFO_SUPPORTED 1780 /* Return information about the row currently being processed. Note that these 1781 * APIs do not fail but will return unexpected results if called outside a user 1782 * transform callback. Also note that when transforming an interlaced image the 1783 * row number is the row number within the sub-image of the interlace pass, so 1784 * the value will increase to the height of the sub-image (not the full image) 1785 * then reset to 0 for the next pass. 1786 * 1787 * Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to 1788 * find the output pixel (x,y) given an interlaced sub-image pixel 1789 * (row,col,pass). (See below for these macros.) 1790 */ 1791 PNG_EXPORT(217, png_uint_32, png_get_current_row_number, (png_const_structrp)); 1792 PNG_EXPORT(218, png_byte, png_get_current_pass_number, (png_const_structrp)); 1793 #endif 1794 1795 #ifdef PNG_READ_USER_CHUNKS_SUPPORTED 1796 /* This callback is called only for *unknown* chunks. If 1797 * PNG_HANDLE_AS_UNKNOWN_SUPPORTED is set then it is possible to set known 1798 * chunks to be treated as unknown, however in this case the callback must do 1799 * any processing required by the chunk (e.g. by calling the appropriate 1800 * png_set_ APIs.) 1801 * 1802 * There is no write support - on write, by default, all the chunks in the 1803 * 'unknown' list are written in the specified position. 1804 * 1805 * The integer return from the callback function is interpreted thus: 1806 * 1807 * negative: An error occured, png_chunk_error will be called. 1808 * zero: The chunk was not handled, the chunk will be saved. A critical 1809 * chunk will cause an error at this point unless it is to be saved. 1810 * positive: The chunk was handled, libpng will ignore/discard it. 1811 * 1812 * See "INTERACTION WTIH USER CHUNK CALLBACKS" below for important notes about 1813 * how this behavior will change in libpng 1.7 1814 */ 1815 PNG_EXPORT(88, void, png_set_read_user_chunk_fn, (png_structrp png_ptr, 1816 png_voidp user_chunk_ptr, png_user_chunk_ptr read_user_chunk_fn)); 1817 #endif 1818 1819 #ifdef PNG_USER_CHUNKS_SUPPORTED 1820 PNG_EXPORT(89, png_voidp, png_get_user_chunk_ptr, (png_const_structrp png_ptr)); 1821 #endif 1822 1823 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED 1824 /* Sets the function callbacks for the push reader, and a pointer to a 1825 * user-defined structure available to the callback functions. 1826 */ 1827 PNG_EXPORT(90, void, png_set_progressive_read_fn, (png_structrp png_ptr, 1828 png_voidp progressive_ptr, png_progressive_info_ptr info_fn, 1829 png_progressive_row_ptr row_fn, png_progressive_end_ptr end_fn)); 1830 1831 /* Returns the user pointer associated with the push read functions */ 1832 PNG_EXPORT(91, png_voidp, png_get_progressive_ptr, 1833 (png_const_structrp png_ptr)); 1834 1835 /* Function to be called when data becomes available */ 1836 PNG_EXPORT(92, void, png_process_data, (png_structrp png_ptr, 1837 png_inforp info_ptr, png_bytep buffer, png_size_t buffer_size)); 1838 1839 /* A function which may be called *only* within png_process_data to stop the 1840 * processing of any more data. The function returns the number of bytes 1841 * remaining, excluding any that libpng has cached internally. A subsequent 1842 * call to png_process_data must supply these bytes again. If the argument 1843 * 'save' is set to true the routine will first save all the pending data and 1844 * will always return 0. 1845 */ 1846 PNG_EXPORT(219, png_size_t, png_process_data_pause, (png_structrp, int save)); 1847 1848 /* A function which may be called *only* outside (after) a call to 1849 * png_process_data. It returns the number of bytes of data to skip in the 1850 * input. Normally it will return 0, but if it returns a non-zero value the 1851 * application must skip than number of bytes of input data and pass the 1852 * following data to the next call to png_process_data. 1853 */ 1854 PNG_EXPORT(220, png_uint_32, png_process_data_skip, (png_structrp)); 1855 1856 #ifdef PNG_READ_INTERLACING_SUPPORTED 1857 /* Function that combines rows. 'new_row' is a flag that should come from 1858 * the callback and be non-NULL if anything needs to be done; the library 1859 * stores its own version of the new data internally and ignores the passed 1860 * in value. 1861 */ 1862 PNG_EXPORT(93, void, png_progressive_combine_row, (png_const_structrp png_ptr, 1863 png_bytep old_row, png_const_bytep new_row)); 1864 #endif /* PNG_READ_INTERLACING_SUPPORTED */ 1865 #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */ 1866 1867 PNG_EXPORTA(94, png_voidp, png_malloc, (png_const_structrp png_ptr, 1868 png_alloc_size_t size), PNG_ALLOCATED); 1869 /* Added at libpng version 1.4.0 */ 1870 PNG_EXPORTA(95, png_voidp, png_calloc, (png_const_structrp png_ptr, 1871 png_alloc_size_t size), PNG_ALLOCATED); 1872 1873 /* Added at libpng version 1.2.4 */ 1874 PNG_EXPORTA(96, png_voidp, png_malloc_warn, (png_const_structrp png_ptr, 1875 png_alloc_size_t size), PNG_ALLOCATED); 1876 1877 /* Frees a pointer allocated by png_malloc() */ 1878 PNG_EXPORT(97, void, png_free, (png_const_structrp png_ptr, png_voidp ptr)); 1879 1880 /* Free data that was allocated internally */ 1881 PNG_EXPORT(98, void, png_free_data, (png_const_structrp png_ptr, 1882 png_inforp info_ptr, png_uint_32 free_me, int num)); 1883 1884 /* Reassign responsibility for freeing existing data, whether allocated 1885 * by libpng or by the application; this works on the png_info structure passed 1886 * in, it does not change the state for other png_info structures. 1887 * 1888 * It is unlikely that this function works correctly as of 1.6.0 and using it 1889 * may result either in memory leaks or double free of allocated data. 1890 */ 1891 PNG_EXPORT(99, void, png_data_freer, (png_const_structrp png_ptr, 1892 png_inforp info_ptr, int freer, png_uint_32 mask)); 1893 1894 #ifdef PNG_INDEX_SUPPORTED 1895 /* Build image index for partial image decoding. */ 1896 PNG_EXPORT(300, void, png_build_index, (png_structp png_ptr)); 1897 PNG_EXPORT(301, void, png_configure_decoder, 1898 (png_structp png_ptr, int *row_offset, int pass)); 1899 /* Set the data seek function with a user supplied one. 1900 * REQUIRED by partial image decode. 1901 */ 1902 PNG_EXPORT(302, void, png_set_seek_fn, (png_structp png_ptr, 1903 png_seek_ptr seek_data_fn)); 1904 /* Update the decoder status to the given pass */ 1905 PNG_EXPORT(303, void, png_set_interlaced_pass, (png_structp png_ptr, int pass)); 1906 #endif 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 #ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED 1920 # define PNG_FREE_UNKN 0x0200 1921 #endif 1922 /* PNG_FREE_LIST 0x0400 removed in 1.6.0 because it is ignored */ 1923 #define PNG_FREE_PLTE 0x1000 1924 #define PNG_FREE_TRNS 0x2000 1925 #define PNG_FREE_TEXT 0x4000 1926 #define PNG_FREE_ALL 0x7fff 1927 #define PNG_FREE_MUL 0x4220 /* PNG_FREE_SPLT|PNG_FREE_TEXT|PNG_FREE_UNKN */ 1928 1929 #ifdef PNG_USER_MEM_SUPPORTED 1930 PNG_EXPORTA(100, png_voidp, png_malloc_default, (png_const_structrp png_ptr, 1931 png_alloc_size_t size), PNG_ALLOCATED PNG_DEPRECATED); 1932 PNG_EXPORTA(101, void, png_free_default, (png_const_structrp png_ptr, 1933 png_voidp ptr), PNG_DEPRECATED); 1934 #endif 1935 1936 #ifdef PNG_ERROR_TEXT_SUPPORTED 1937 /* Fatal error in PNG image of libpng - can't continue */ 1938 PNG_EXPORTA(102, void, png_error, (png_const_structrp png_ptr, 1939 png_const_charp error_message), PNG_NORETURN); 1940 1941 /* The same, but the chunk name is prepended to the error string. */ 1942 PNG_EXPORTA(103, void, png_chunk_error, (png_const_structrp png_ptr, 1943 png_const_charp error_message), PNG_NORETURN); 1944 1945 #else 1946 /* Fatal error in PNG image of libpng - can't continue */ 1947 PNG_EXPORTA(104, void, png_err, (png_const_structrp png_ptr), PNG_NORETURN); 1948 # define png_error(s1,s2) png_err(s1) 1949 # define png_chunk_error(s1,s2) png_err(s1) 1950 #endif 1951 1952 #ifdef PNG_WARNINGS_SUPPORTED 1953 /* Non-fatal error in libpng. Can continue, but may have a problem. */ 1954 PNG_EXPORT(105, void, png_warning, (png_const_structrp png_ptr, 1955 png_const_charp warning_message)); 1956 1957 /* Non-fatal error in libpng, chunk name is prepended to message. */ 1958 PNG_EXPORT(106, void, png_chunk_warning, (png_const_structrp png_ptr, 1959 png_const_charp warning_message)); 1960 #else 1961 # define png_warning(s1,s2) ((void)(s1)) 1962 # define png_chunk_warning(s1,s2) ((void)(s1)) 1963 #endif 1964 1965 #ifdef PNG_BENIGN_ERRORS_SUPPORTED 1966 /* Benign error in libpng. Can continue, but may have a problem. 1967 * User can choose whether to handle as a fatal error or as a warning. */ 1968 PNG_EXPORT(107, void, png_benign_error, (png_const_structrp png_ptr, 1969 png_const_charp warning_message)); 1970 1971 #ifdef PNG_READ_SUPPORTED 1972 /* Same, chunk name is prepended to message (only during read) */ 1973 PNG_EXPORT(108, void, png_chunk_benign_error, (png_const_structrp png_ptr, 1974 png_const_charp warning_message)); 1975 #endif 1976 1977 PNG_EXPORT(109, void, png_set_benign_errors, 1978 (png_structrp png_ptr, int allowed)); 1979 #else 1980 # ifdef PNG_ALLOW_BENIGN_ERRORS 1981 # define png_benign_error png_warning 1982 # define png_chunk_benign_error png_chunk_warning 1983 # else 1984 # define png_benign_error png_error 1985 # define png_chunk_benign_error png_chunk_error 1986 # endif 1987 #endif 1988 1989 /* The png_set_<chunk> functions are for storing values in the png_info_struct. 1990 * Similarly, the png_get_<chunk> calls are used to read values from the 1991 * png_info_struct, either storing the parameters in the passed variables, or 1992 * setting pointers into the png_info_struct where the data is stored. The 1993 * png_get_<chunk> functions return a non-zero value if the data was available 1994 * in info_ptr, or return zero and do not change any of the parameters if the 1995 * data was not available. 1996 * 1997 * These functions should be used instead of directly accessing png_info 1998 * to avoid problems with future changes in the size and internal layout of 1999 * png_info_struct. 2000 */ 2001 /* Returns "flag" if chunk data is valid in info_ptr. */ 2002 PNG_EXPORT(110, png_uint_32, png_get_valid, (png_const_structrp png_ptr, 2003 png_const_inforp info_ptr, png_uint_32 flag)); 2004 2005 /* Returns number of bytes needed to hold a transformed row. */ 2006 PNG_EXPORT(111, png_size_t, png_get_rowbytes, (png_const_structrp png_ptr, 2007 png_const_inforp info_ptr)); 2008 2009 #ifdef PNG_INFO_IMAGE_SUPPORTED 2010 /* Returns row_pointers, which is an array of pointers to scanlines that was 2011 * returned from png_read_png(). 2012 */ 2013 PNG_EXPORT(112, png_bytepp, png_get_rows, (png_const_structrp png_ptr, 2014 png_const_inforp info_ptr)); 2015 2016 /* Set row_pointers, which is an array of pointers to scanlines for use 2017 * by png_write_png(). 2018 */ 2019 PNG_EXPORT(113, void, png_set_rows, (png_const_structrp png_ptr, 2020 png_inforp info_ptr, png_bytepp row_pointers)); 2021 #endif 2022 2023 /* Returns number of color channels in image. */ 2024 PNG_EXPORT(114, png_byte, png_get_channels, (png_const_structrp png_ptr, 2025 png_const_inforp info_ptr)); 2026 2027 #ifdef PNG_EASY_ACCESS_SUPPORTED 2028 /* Returns image width in pixels. */ 2029 PNG_EXPORT(115, png_uint_32, png_get_image_width, (png_const_structrp png_ptr, 2030 png_const_inforp info_ptr)); 2031 2032 /* Returns image height in pixels. */ 2033 PNG_EXPORT(116, png_uint_32, png_get_image_height, (png_const_structrp png_ptr, 2034 png_const_inforp info_ptr)); 2035 2036 /* Returns image bit_depth. */ 2037 PNG_EXPORT(117, png_byte, png_get_bit_depth, (png_const_structrp png_ptr, 2038 png_const_inforp info_ptr)); 2039 2040 /* Returns image color_type. */ 2041 PNG_EXPORT(118, png_byte, png_get_color_type, (png_const_structrp png_ptr, 2042 png_const_inforp info_ptr)); 2043 2044 /* Returns image filter_type. */ 2045 PNG_EXPORT(119, png_byte, png_get_filter_type, (png_const_structrp png_ptr, 2046 png_const_inforp info_ptr)); 2047 2048 /* Returns image interlace_type. */ 2049 PNG_EXPORT(120, png_byte, png_get_interlace_type, (png_const_structrp png_ptr, 2050 png_const_inforp info_ptr)); 2051 2052 /* Returns image compression_type. */ 2053 PNG_EXPORT(121, png_byte, png_get_compression_type, (png_const_structrp png_ptr, 2054 png_const_inforp info_ptr)); 2055 2056 /* Returns image resolution in pixels per meter, from pHYs chunk data. */ 2057 PNG_EXPORT(122, png_uint_32, png_get_pixels_per_meter, 2058 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 2059 PNG_EXPORT(123, png_uint_32, png_get_x_pixels_per_meter, 2060 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 2061 PNG_EXPORT(124, png_uint_32, png_get_y_pixels_per_meter, 2062 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 2063 2064 /* Returns pixel aspect ratio, computed from pHYs chunk data. */ 2065 PNG_FP_EXPORT(125, float, png_get_pixel_aspect_ratio, 2066 (png_const_structrp png_ptr, png_const_inforp info_ptr)) 2067 PNG_FIXED_EXPORT(210, png_fixed_point, png_get_pixel_aspect_ratio_fixed, 2068 (png_const_structrp png_ptr, png_const_inforp info_ptr)) 2069 2070 /* Returns image x, y offset in pixels or microns, from oFFs chunk data. */ 2071 PNG_EXPORT(126, png_int_32, png_get_x_offset_pixels, 2072 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 2073 PNG_EXPORT(127, png_int_32, png_get_y_offset_pixels, 2074 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 2075 PNG_EXPORT(128, png_int_32, png_get_x_offset_microns, 2076 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 2077 PNG_EXPORT(129, png_int_32, png_get_y_offset_microns, 2078 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 2079 2080 #endif /* PNG_EASY_ACCESS_SUPPORTED */ 2081 2082 #ifdef PNG_READ_SUPPORTED 2083 /* Returns pointer to signature string read from PNG header */ 2084 PNG_EXPORT(130, png_const_bytep, png_get_signature, (png_const_structrp png_ptr, 2085 png_const_inforp info_ptr)); 2086 #endif 2087 2088 #ifdef PNG_bKGD_SUPPORTED 2089 PNG_EXPORT(131, png_uint_32, png_get_bKGD, (png_const_structrp png_ptr, 2090 png_inforp info_ptr, png_color_16p *background)); 2091 #endif 2092 2093 #ifdef PNG_bKGD_SUPPORTED 2094 PNG_EXPORT(132, void, png_set_bKGD, (png_const_structrp png_ptr, 2095 png_inforp info_ptr, png_const_color_16p background)); 2096 #endif 2097 2098 #ifdef PNG_cHRM_SUPPORTED 2099 PNG_FP_EXPORT(133, png_uint_32, png_get_cHRM, (png_const_structrp png_ptr, 2100 png_const_inforp info_ptr, double *white_x, double *white_y, double *red_x, 2101 double *red_y, double *green_x, double *green_y, double *blue_x, 2102 double *blue_y)) 2103 PNG_FP_EXPORT(230, png_uint_32, png_get_cHRM_XYZ, (png_const_structrp png_ptr, 2104 png_const_inforp info_ptr, double *red_X, double *red_Y, double *red_Z, 2105 double *green_X, double *green_Y, double *green_Z, double *blue_X, 2106 double *blue_Y, double *blue_Z)) 2107 PNG_FIXED_EXPORT(134, png_uint_32, png_get_cHRM_fixed, 2108 (png_const_structrp png_ptr, png_const_inforp info_ptr, 2109 png_fixed_point *int_white_x, png_fixed_point *int_white_y, 2110 png_fixed_point *int_red_x, png_fixed_point *int_red_y, 2111 png_fixed_point *int_green_x, png_fixed_point *int_green_y, 2112 png_fixed_point *int_blue_x, png_fixed_point *int_blue_y)) 2113 PNG_FIXED_EXPORT(231, png_uint_32, png_get_cHRM_XYZ_fixed, 2114 (png_const_structrp png_ptr, png_const_inforp info_ptr, 2115 png_fixed_point *int_red_X, png_fixed_point *int_red_Y, 2116 png_fixed_point *int_red_Z, png_fixed_point *int_green_X, 2117 png_fixed_point *int_green_Y, png_fixed_point *int_green_Z, 2118 png_fixed_point *int_blue_X, png_fixed_point *int_blue_Y, 2119 png_fixed_point *int_blue_Z)) 2120 #endif 2121 2122 #ifdef PNG_cHRM_SUPPORTED 2123 PNG_FP_EXPORT(135, void, png_set_cHRM, (png_const_structrp png_ptr, 2124 png_inforp info_ptr, 2125 double white_x, double white_y, double red_x, double red_y, double green_x, 2126 double green_y, double blue_x, double blue_y)) 2127 PNG_FP_EXPORT(232, void, png_set_cHRM_XYZ, (png_const_structrp png_ptr, 2128 png_inforp info_ptr, double red_X, double red_Y, double red_Z, 2129 double green_X, double green_Y, double green_Z, double blue_X, 2130 double blue_Y, double blue_Z)) 2131 PNG_FIXED_EXPORT(136, void, png_set_cHRM_fixed, (png_const_structrp png_ptr, 2132 png_inforp info_ptr, png_fixed_point int_white_x, 2133 png_fixed_point int_white_y, png_fixed_point int_red_x, 2134 png_fixed_point int_red_y, png_fixed_point int_green_x, 2135 png_fixed_point int_green_y, png_fixed_point int_blue_x, 2136 png_fixed_point int_blue_y)) 2137 PNG_FIXED_EXPORT(233, void, png_set_cHRM_XYZ_fixed, (png_const_structrp png_ptr, 2138 png_inforp info_ptr, png_fixed_point int_red_X, png_fixed_point int_red_Y, 2139 png_fixed_point int_red_Z, png_fixed_point int_green_X, 2140 png_fixed_point int_green_Y, png_fixed_point int_green_Z, 2141 png_fixed_point int_blue_X, png_fixed_point int_blue_Y, 2142 png_fixed_point int_blue_Z)) 2143 #endif 2144 2145 #ifdef PNG_gAMA_SUPPORTED 2146 PNG_FP_EXPORT(137, png_uint_32, png_get_gAMA, (png_const_structrp png_ptr, 2147 png_const_inforp info_ptr, double *file_gamma)) 2148 PNG_FIXED_EXPORT(138, png_uint_32, png_get_gAMA_fixed, 2149 (png_const_structrp png_ptr, png_const_inforp info_ptr, 2150 png_fixed_point *int_file_gamma)) 2151 #endif 2152 2153 #ifdef PNG_gAMA_SUPPORTED 2154 PNG_FP_EXPORT(139, void, png_set_gAMA, (png_const_structrp png_ptr, 2155 png_inforp info_ptr, double file_gamma)) 2156 PNG_FIXED_EXPORT(140, void, png_set_gAMA_fixed, (png_const_structrp png_ptr, 2157 png_inforp info_ptr, png_fixed_point int_file_gamma)) 2158 #endif 2159 2160 #ifdef PNG_hIST_SUPPORTED 2161 PNG_EXPORT(141, png_uint_32, png_get_hIST, (png_const_structrp png_ptr, 2162 png_inforp info_ptr, png_uint_16p *hist)); 2163 #endif 2164 2165 #ifdef PNG_hIST_SUPPORTED 2166 PNG_EXPORT(142, void, png_set_hIST, (png_const_structrp png_ptr, 2167 png_inforp info_ptr, png_const_uint_16p hist)); 2168 #endif 2169 2170 PNG_EXPORT(143, png_uint_32, png_get_IHDR, (png_const_structrp png_ptr, 2171 png_const_inforp info_ptr, png_uint_32 *width, png_uint_32 *height, 2172 int *bit_depth, int *color_type, int *interlace_method, 2173 int *compression_method, int *filter_method)); 2174 2175 PNG_EXPORT(144, void, png_set_IHDR, (png_const_structrp png_ptr, 2176 png_inforp info_ptr, png_uint_32 width, png_uint_32 height, int bit_depth, 2177 int color_type, int interlace_method, int compression_method, 2178 int filter_method)); 2179 2180 #ifdef PNG_oFFs_SUPPORTED 2181 PNG_EXPORT(145, png_uint_32, png_get_oFFs, (png_const_structrp png_ptr, 2182 png_const_inforp info_ptr, png_int_32 *offset_x, png_int_32 *offset_y, 2183 int *unit_type)); 2184 #endif 2185 2186 #ifdef PNG_oFFs_SUPPORTED 2187 PNG_EXPORT(146, void, png_set_oFFs, (png_const_structrp png_ptr, 2188 png_inforp info_ptr, png_int_32 offset_x, png_int_32 offset_y, 2189 int unit_type)); 2190 #endif 2191 2192 #ifdef PNG_pCAL_SUPPORTED 2193 PNG_EXPORT(147, png_uint_32, png_get_pCAL, (png_const_structrp png_ptr, 2194 png_inforp info_ptr, png_charp *purpose, png_int_32 *X0, 2195 png_int_32 *X1, int *type, int *nparams, png_charp *units, 2196 png_charpp *params)); 2197 #endif 2198 2199 #ifdef PNG_pCAL_SUPPORTED 2200 PNG_EXPORT(148, void, png_set_pCAL, (png_const_structrp png_ptr, 2201 png_inforp info_ptr, png_const_charp purpose, png_int_32 X0, png_int_32 X1, 2202 int type, int nparams, png_const_charp units, png_charpp params)); 2203 #endif 2204 2205 #ifdef PNG_pHYs_SUPPORTED 2206 PNG_EXPORT(149, png_uint_32, png_get_pHYs, (png_const_structrp png_ptr, 2207 png_const_inforp info_ptr, png_uint_32 *res_x, png_uint_32 *res_y, 2208 int *unit_type)); 2209 #endif 2210 2211 #ifdef PNG_pHYs_SUPPORTED 2212 PNG_EXPORT(150, void, png_set_pHYs, (png_const_structrp png_ptr, 2213 png_inforp info_ptr, 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, (png_const_structrp png_ptr, 2217 png_inforp info_ptr, png_colorp *palette, int *num_palette)); 2218 2219 PNG_EXPORT(152, void, png_set_PLTE, (png_structrp png_ptr, 2220 png_inforp info_ptr, png_const_colorp palette, int num_palette)); 2221 2222 #ifdef PNG_sBIT_SUPPORTED 2223 PNG_EXPORT(153, png_uint_32, png_get_sBIT, (png_const_structrp png_ptr, 2224 png_inforp info_ptr, png_color_8p *sig_bit)); 2225 #endif 2226 2227 #ifdef PNG_sBIT_SUPPORTED 2228 PNG_EXPORT(154, void, png_set_sBIT, (png_const_structrp png_ptr, 2229 png_inforp info_ptr, png_const_color_8p sig_bit)); 2230 #endif 2231 2232 #ifdef PNG_sRGB_SUPPORTED 2233 PNG_EXPORT(155, png_uint_32, png_get_sRGB, (png_const_structrp png_ptr, 2234 png_const_inforp info_ptr, int *file_srgb_intent)); 2235 #endif 2236 2237 #ifdef PNG_sRGB_SUPPORTED 2238 PNG_EXPORT(156, void, png_set_sRGB, (png_const_structrp png_ptr, 2239 png_inforp info_ptr, int srgb_intent)); 2240 PNG_EXPORT(157, void, png_set_sRGB_gAMA_and_cHRM, (png_const_structrp png_ptr, 2241 png_inforp info_ptr, int srgb_intent)); 2242 #endif 2243 2244 #ifdef PNG_iCCP_SUPPORTED 2245 PNG_EXPORT(158, png_uint_32, png_get_iCCP, (png_const_structrp png_ptr, 2246 png_inforp info_ptr, png_charpp name, int *compression_type, 2247 png_bytepp profile, png_uint_32 *proflen)); 2248 #endif 2249 2250 #ifdef PNG_iCCP_SUPPORTED 2251 PNG_EXPORT(159, void, png_set_iCCP, (png_const_structrp png_ptr, 2252 png_inforp info_ptr, png_const_charp name, int compression_type, 2253 png_const_bytep profile, png_uint_32 proflen)); 2254 #endif 2255 2256 #ifdef PNG_sPLT_SUPPORTED 2257 PNG_EXPORT(160, int, png_get_sPLT, (png_const_structrp png_ptr, 2258 png_inforp info_ptr, png_sPLT_tpp entries)); 2259 #endif 2260 2261 #ifdef PNG_sPLT_SUPPORTED 2262 PNG_EXPORT(161, void, png_set_sPLT, (png_const_structrp png_ptr, 2263 png_inforp info_ptr, png_const_sPLT_tp entries, int nentries)); 2264 #endif 2265 2266 #ifdef PNG_TEXT_SUPPORTED 2267 /* png_get_text also returns the number of text chunks in *num_text */ 2268 PNG_EXPORT(162, int, png_get_text, (png_const_structrp png_ptr, 2269 png_inforp info_ptr, png_textp *text_ptr, int *num_text)); 2270 #endif 2271 2272 /* Note while png_set_text() will accept a structure whose text, 2273 * language, and translated keywords are NULL pointers, the structure 2274 * returned by png_get_text will always contain regular 2275 * zero-terminated C strings. They might be empty strings but 2276 * they will never be NULL pointers. 2277 */ 2278 2279 #ifdef PNG_TEXT_SUPPORTED 2280 PNG_EXPORT(163, void, png_set_text, (png_const_structrp png_ptr, 2281 png_inforp info_ptr, png_const_textp text_ptr, int num_text)); 2282 #endif 2283 2284 #ifdef PNG_tIME_SUPPORTED 2285 PNG_EXPORT(164, png_uint_32, png_get_tIME, (png_const_structrp png_ptr, 2286 png_inforp info_ptr, png_timep *mod_time)); 2287 #endif 2288 2289 #ifdef PNG_tIME_SUPPORTED 2290 PNG_EXPORT(165, void, png_set_tIME, (png_const_structrp png_ptr, 2291 png_inforp info_ptr, png_const_timep mod_time)); 2292 #endif 2293 2294 #ifdef PNG_tRNS_SUPPORTED 2295 PNG_EXPORT(166, png_uint_32, png_get_tRNS, (png_const_structrp png_ptr, 2296 png_inforp info_ptr, png_bytep *trans_alpha, int *num_trans, 2297 png_color_16p *trans_color)); 2298 #endif 2299 2300 #ifdef PNG_tRNS_SUPPORTED 2301 PNG_EXPORT(167, void, png_set_tRNS, (png_structrp png_ptr, 2302 png_inforp info_ptr, png_const_bytep trans_alpha, int num_trans, 2303 png_const_color_16p trans_color)); 2304 #endif 2305 2306 #ifdef PNG_sCAL_SUPPORTED 2307 PNG_FP_EXPORT(168, png_uint_32, png_get_sCAL, (png_const_structrp png_ptr, 2308 png_const_inforp info_ptr, int *unit, double *width, double *height)) 2309 #if defined(PNG_FLOATING_ARITHMETIC_SUPPORTED) || \ 2310 defined(PNG_FLOATING_POINT_SUPPORTED) 2311 /* NOTE: this API is currently implemented using floating point arithmetic, 2312 * consequently it can only be used on systems with floating point support. 2313 * In any case the range of values supported by png_fixed_point is small and it 2314 * is highly recommended that png_get_sCAL_s be used instead. 2315 */ 2316 PNG_FIXED_EXPORT(214, png_uint_32, png_get_sCAL_fixed, 2317 (png_const_structrp png_ptr, png_const_inforp info_ptr, int *unit, 2318 png_fixed_point *width, png_fixed_point *height)) 2319 #endif 2320 PNG_EXPORT(169, png_uint_32, png_get_sCAL_s, 2321 (png_const_structrp png_ptr, png_const_inforp info_ptr, int *unit, 2322 png_charpp swidth, png_charpp sheight)); 2323 2324 PNG_FP_EXPORT(170, void, png_set_sCAL, (png_const_structrp png_ptr, 2325 png_inforp info_ptr, int unit, double width, double height)) 2326 PNG_FIXED_EXPORT(213, void, png_set_sCAL_fixed, (png_const_structrp png_ptr, 2327 png_inforp info_ptr, int unit, png_fixed_point width, 2328 png_fixed_point height)) 2329 PNG_EXPORT(171, void, png_set_sCAL_s, (png_const_structrp png_ptr, 2330 png_inforp info_ptr, int unit, 2331 png_const_charp swidth, png_const_charp sheight)); 2332 #endif /* PNG_sCAL_SUPPORTED */ 2333 2334 #ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED 2335 /* Provide the default handling for all unknown chunks or, optionally, for 2336 * specific unknown chunks. 2337 * 2338 * NOTE: prior to 1.6.0 the handling specified for particular chunks on read was 2339 * ignored and the default was used, the per-chunk setting only had an effect on 2340 * write. If you wish to have chunk-specific handling on read in code that must 2341 * work on earlier versions you must use a user chunk callback to specify the 2342 * desired handling (keep or discard.) 2343 * 2344 * The 'keep' parameter is a PNG_HANDLE_CHUNK_ value as listed below. The 2345 * parameter is interpreted as follows: 2346 * 2347 * READ: 2348 * PNG_HANDLE_CHUNK_AS_DEFAULT: 2349 * Known chunks: do normal libpng processing, do not keep the chunk (but 2350 * see the comments below about PNG_HANDLE_AS_UNKNOWN_SUPPORTED) 2351 * Unknown chunks: for a specific chunk use the global default, when used 2352 * as the default discard the chunk data. 2353 * PNG_HANDLE_CHUNK_NEVER: 2354 * Discard the chunk data. 2355 * PNG_HANDLE_CHUNK_IF_SAFE: 2356 * Keep the chunk data if the chunk is not critical else raise a chunk 2357 * error. 2358 * PNG_HANDLE_CHUNK_ALWAYS: 2359 * Keep the chunk data. 2360 * 2361 * If the chunk data is saved it can be retrieved using png_get_unknown_chunks, 2362 * below. Notice that specifying "AS_DEFAULT" as a global default is equivalent 2363 * to specifying "NEVER", however when "AS_DEFAULT" is used for specific chunks 2364 * it simply resets the behavior to the libpng default. 2365 * 2366 * INTERACTION WTIH USER CHUNK CALLBACKS: 2367 * The per-chunk handling is always used when there is a png_user_chunk_ptr 2368 * callback and the callback returns 0; the chunk is then always stored *unless* 2369 * it is critical and the per-chunk setting is other than ALWAYS. Notice that 2370 * the global default is *not* used in this case. (In effect the per-chunk 2371 * value is incremented to at least IF_SAFE.) 2372 * 2373 * IMPORTANT NOTE: this behavior will change in libpng 1.7 - the global and 2374 * per-chunk defaults will be honored. If you want to preserve the current 2375 * behavior when your callback returns 0 you must set PNG_HANDLE_CHUNK_IF_SAFE 2376 * as the default - if you don't do this libpng 1.6 will issue a warning. 2377 * 2378 * If you want unhandled unknown chunks to be discarded in libpng 1.6 and 2379 * earlier simply return '1' (handled). 2380 * 2381 * PNG_HANDLE_AS_UNKNOWN_SUPPORTED: 2382 * If this is *not* set known chunks will always be handled by libpng and 2383 * will never be stored in the unknown chunk list. Known chunks listed to 2384 * png_set_keep_unknown_chunks will have no effect. If it is set then known 2385 * chunks listed with a keep other than AS_DEFAULT will *never* be processed 2386 * by libpng, in addition critical chunks must either be processed by the 2387 * callback or saved. 2388 * 2389 * The IHDR and IEND chunks must not be listed. Because this turns off the 2390 * default handling for chunks that would otherwise be recognized the 2391 * behavior of libpng transformations may well become incorrect! 2392 * 2393 * WRITE: 2394 * When writing chunks the options only apply to the chunks specified by 2395 * png_set_unknown_chunks (below), libpng will *always* write known chunks 2396 * required by png_set_ calls and will always write the core critical chunks 2397 * (as required for PLTE). 2398 * 2399 * Each chunk in the png_set_unknown_chunks list is looked up in the 2400 * png_set_keep_unknown_chunks list to find the keep setting, this is then 2401 * interpreted as follows: 2402 * 2403 * PNG_HANDLE_CHUNK_AS_DEFAULT: 2404 * Write safe-to-copy chunks and write other chunks if the global 2405 * default is set to _ALWAYS, otherwise don't write this chunk. 2406 * PNG_HANDLE_CHUNK_NEVER: 2407 * Do not write the chunk. 2408 * PNG_HANDLE_CHUNK_IF_SAFE: 2409 * Write the chunk if it is safe-to-copy, otherwise do not write it. 2410 * PNG_HANDLE_CHUNK_ALWAYS: 2411 * Write the chunk. 2412 * 2413 * Note that the default behavior is effectively the opposite of the read case - 2414 * in read unknown chunks are not stored by default, in write they are written 2415 * by default. Also the behavior of PNG_HANDLE_CHUNK_IF_SAFE is very different 2416 * - on write the safe-to-copy bit is checked, on read the critical bit is 2417 * checked and on read if the chunk is critical an error will be raised. 2418 * 2419 * num_chunks: 2420 * =========== 2421 * If num_chunks is positive, then the "keep" parameter specifies the manner 2422 * for handling only those chunks appearing in the chunk_list array, 2423 * otherwise the chunk list array is ignored. 2424 * 2425 * If num_chunks is 0 the "keep" parameter specifies the default behavior for 2426 * unknown chunks, as described above. 2427 * 2428 * If num_chunks is negative, then the "keep" parameter specifies the manner 2429 * for handling all unknown chunks plus all chunks recognized by libpng 2430 * except for the IHDR, PLTE, tRNS, IDAT, and IEND chunks (which continue to 2431 * be processed by libpng. 2432 */ 2433 PNG_EXPORT(172, void, png_set_keep_unknown_chunks, (png_structrp png_ptr, 2434 int keep, png_const_bytep chunk_list, int num_chunks)); 2435 2436 /* The "keep" PNG_HANDLE_CHUNK_ parameter for the specified chunk is returned; 2437 * the result is therefore true (non-zero) if special handling is required, 2438 * false for the default handling. 2439 */ 2440 PNG_EXPORT(173, int, png_handle_as_unknown, (png_const_structrp png_ptr, 2441 png_const_bytep chunk_name)); 2442 #endif 2443 2444 #ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED 2445 PNG_EXPORT(174, void, png_set_unknown_chunks, (png_const_structrp png_ptr, 2446 png_inforp info_ptr, png_const_unknown_chunkp unknowns, 2447 int num_unknowns)); 2448 /* NOTE: prior to 1.6.0 this routine set the 'location' field of the added 2449 * unknowns to the location currently stored in the png_struct. This is 2450 * invariably the wrong value on write. To fix this call the following API 2451 * for each chunk in the list with the correct location. If you know your 2452 * code won't be compiled on earlier versions you can rely on 2453 * png_set_unknown_chunks(write-ptr, png_get_unknown_chunks(read-ptr)) doing 2454 * the correct thing. 2455 */ 2456 2457 PNG_EXPORT(175, void, png_set_unknown_chunk_location, 2458 (png_const_structrp png_ptr, png_inforp info_ptr, int chunk, int location)); 2459 2460 PNG_EXPORT(176, int, png_get_unknown_chunks, (png_const_structrp png_ptr, 2461 png_inforp info_ptr, png_unknown_chunkpp entries)); 2462 #endif 2463 2464 /* Png_free_data() will turn off the "valid" flag for anything it frees. 2465 * If you need to turn it off for a chunk that your application has freed, 2466 * you can use png_set_invalid(png_ptr, info_ptr, PNG_INFO_CHNK); 2467 */ 2468 PNG_EXPORT(177, void, png_set_invalid, (png_const_structrp png_ptr, 2469 png_inforp info_ptr, int mask)); 2470 2471 #ifdef PNG_INFO_IMAGE_SUPPORTED 2472 /* The "params" pointer is currently not used and is for future expansion. */ 2473 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED 2474 PNG_EXPORT(178, void, png_read_png, (png_structrp png_ptr, png_inforp info_ptr, 2475 int transforms, png_voidp params)); 2476 #endif 2477 #ifdef PNG_WRITE_SUPPORTED 2478 PNG_EXPORT(179, void, png_write_png, (png_structrp png_ptr, png_inforp info_ptr, 2479 int transforms, png_voidp params)); 2480 #endif 2481 #endif 2482 2483 PNG_EXPORT(180, png_const_charp, png_get_copyright, 2484 (png_const_structrp png_ptr)); 2485 PNG_EXPORT(181, png_const_charp, png_get_header_ver, 2486 (png_const_structrp png_ptr)); 2487 PNG_EXPORT(182, png_const_charp, png_get_header_version, 2488 (png_const_structrp png_ptr)); 2489 PNG_EXPORT(183, png_const_charp, png_get_libpng_ver, 2490 (png_const_structrp png_ptr)); 2491 2492 #ifdef PNG_MNG_FEATURES_SUPPORTED 2493 PNG_EXPORT(184, png_uint_32, png_permit_mng_features, (png_structrp png_ptr, 2494 png_uint_32 mng_features_permitted)); 2495 #endif 2496 2497 /* For use in png_set_keep_unknown, added to version 1.2.6 */ 2498 #define PNG_HANDLE_CHUNK_AS_DEFAULT 0 2499 #define PNG_HANDLE_CHUNK_NEVER 1 2500 #define PNG_HANDLE_CHUNK_IF_SAFE 2 2501 #define PNG_HANDLE_CHUNK_ALWAYS 3 2502 #define PNG_HANDLE_CHUNK_LAST 4 2503 2504 /* Strip the prepended error numbers ("#nnn ") from error and warning 2505 * messages before passing them to the error or warning handler. 2506 */ 2507 #ifdef PNG_ERROR_NUMBERS_SUPPORTED 2508 PNG_EXPORT(185, void, png_set_strip_error_numbers, (png_structrp png_ptr, 2509 png_uint_32 strip_mode)); 2510 #endif 2511 2512 /* Added in libpng-1.2.6 */ 2513 #ifdef PNG_SET_USER_LIMITS_SUPPORTED 2514 PNG_EXPORT(186, void, png_set_user_limits, (png_structrp png_ptr, 2515 png_uint_32 user_width_max, png_uint_32 user_height_max)); 2516 PNG_EXPORT(187, png_uint_32, png_get_user_width_max, 2517 (png_const_structrp png_ptr)); 2518 PNG_EXPORT(188, png_uint_32, png_get_user_height_max, 2519 (png_const_structrp png_ptr)); 2520 /* Added in libpng-1.4.0 */ 2521 PNG_EXPORT(189, void, png_set_chunk_cache_max, (png_structrp png_ptr, 2522 png_uint_32 user_chunk_cache_max)); 2523 PNG_EXPORT(190, png_uint_32, png_get_chunk_cache_max, 2524 (png_const_structrp png_ptr)); 2525 /* Added in libpng-1.4.1 */ 2526 PNG_EXPORT(191, void, png_set_chunk_malloc_max, (png_structrp png_ptr, 2527 png_alloc_size_t user_chunk_cache_max)); 2528 PNG_EXPORT(192, png_alloc_size_t, png_get_chunk_malloc_max, 2529 (png_const_structrp png_ptr)); 2530 #endif 2531 2532 #if defined(PNG_INCH_CONVERSIONS_SUPPORTED) 2533 PNG_EXPORT(193, png_uint_32, png_get_pixels_per_inch, 2534 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 2535 2536 PNG_EXPORT(194, png_uint_32, png_get_x_pixels_per_inch, 2537 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 2538 2539 PNG_EXPORT(195, png_uint_32, png_get_y_pixels_per_inch, 2540 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 2541 2542 PNG_FP_EXPORT(196, float, png_get_x_offset_inches, 2543 (png_const_structrp png_ptr, png_const_inforp info_ptr)) 2544 #ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */ 2545 PNG_FIXED_EXPORT(211, png_fixed_point, png_get_x_offset_inches_fixed, 2546 (png_const_structrp png_ptr, png_const_inforp info_ptr)) 2547 #endif 2548 2549 PNG_FP_EXPORT(197, float, png_get_y_offset_inches, (png_const_structrp png_ptr, 2550 png_const_inforp info_ptr)) 2551 #ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */ 2552 PNG_FIXED_EXPORT(212, png_fixed_point, png_get_y_offset_inches_fixed, 2553 (png_const_structrp png_ptr, png_const_inforp info_ptr)) 2554 #endif 2555 2556 # ifdef PNG_pHYs_SUPPORTED 2557 PNG_EXPORT(198, png_uint_32, png_get_pHYs_dpi, (png_const_structrp png_ptr, 2558 png_const_inforp info_ptr, png_uint_32 *res_x, png_uint_32 *res_y, 2559 int *unit_type)); 2560 # endif /* PNG_pHYs_SUPPORTED */ 2561 #endif /* PNG_INCH_CONVERSIONS_SUPPORTED */ 2562 2563 /* Added in libpng-1.4.0 */ 2564 #ifdef PNG_IO_STATE_SUPPORTED 2565 PNG_EXPORT(199, png_uint_32, png_get_io_state, (png_const_structrp png_ptr)); 2566 2567 /* Removed from libpng 1.6; use png_get_io_chunk_type. */ 2568 PNG_REMOVED(200, png_const_bytep, png_get_io_chunk_name, (png_structrp png_ptr), 2569 PNG_DEPRECATED) 2570 2571 PNG_EXPORT(216, png_uint_32, png_get_io_chunk_type, 2572 (png_const_structrp png_ptr)); 2573 2574 /* The flags returned by png_get_io_state() are the following: */ 2575 # define PNG_IO_NONE 0x0000 /* no I/O at this moment */ 2576 # define PNG_IO_READING 0x0001 /* currently reading */ 2577 # define PNG_IO_WRITING 0x0002 /* currently writing */ 2578 # define PNG_IO_SIGNATURE 0x0010 /* currently at the file signature */ 2579 # define PNG_IO_CHUNK_HDR 0x0020 /* currently at the chunk header */ 2580 # define PNG_IO_CHUNK_DATA 0x0040 /* currently at the chunk data */ 2581 # define PNG_IO_CHUNK_CRC 0x0080 /* currently at the chunk crc */ 2582 # define PNG_IO_MASK_OP 0x000f /* current operation: reading/writing */ 2583 # define PNG_IO_MASK_LOC 0x00f0 /* current location: sig/hdr/data/crc */ 2584 #endif /* ?PNG_IO_STATE_SUPPORTED */ 2585 2586 /* Interlace support. The following macros are always defined so that if 2587 * libpng interlace handling is turned off the macros may be used to handle 2588 * interlaced images within the application. 2589 */ 2590 #define PNG_INTERLACE_ADAM7_PASSES 7 2591 2592 /* Two macros to return the first row and first column of the original, 2593 * full, image which appears in a given pass. 'pass' is in the range 0 2594 * to 6 and the result is in the range 0 to 7. 2595 */ 2596 #define PNG_PASS_START_ROW(pass) (((1&~(pass))<<(3-((pass)>>1)))&7) 2597 #define PNG_PASS_START_COL(pass) (((1& (pass))<<(3-(((pass)+1)>>1)))&7) 2598 2599 /* A macro to return the offset between pixels in the output row for a pair of 2600 * pixels in the input - effectively the inverse of the 'COL_SHIFT' macro that 2601 * follows. Note that ROW_OFFSET is the offset from one row to the next whereas 2602 * COL_OFFSET is from one column to the next, within a row. 2603 */ 2604 #define PNG_PASS_ROW_OFFSET(pass) ((pass)>2?(8>>(((pass)-1)>>1)):8) 2605 #define PNG_PASS_COL_OFFSET(pass) (1<<((7-(pass))>>1)) 2606 2607 /* Two macros to help evaluate the number of rows or columns in each 2608 * pass. This is expressed as a shift - effectively log2 of the number or 2609 * rows or columns in each 8x8 tile of the original image. 2610 */ 2611 #define PNG_PASS_ROW_SHIFT(pass) ((pass)>2?(8-(pass))>>1:3) 2612 #define PNG_PASS_COL_SHIFT(pass) ((pass)>1?(7-(pass))>>1:3) 2613 2614 /* Hence two macros to determine the number of rows or columns in a given 2615 * pass of an image given its height or width. In fact these macros may 2616 * return non-zero even though the sub-image is empty, because the other 2617 * dimension may be empty for a small image. 2618 */ 2619 #define PNG_PASS_ROWS(height, pass) (((height)+(((1<<PNG_PASS_ROW_SHIFT(pass))\ 2620 -1)-PNG_PASS_START_ROW(pass)))>>PNG_PASS_ROW_SHIFT(pass)) 2621 #define PNG_PASS_COLS(width, pass) (((width)+(((1<<PNG_PASS_COL_SHIFT(pass))\ 2622 -1)-PNG_PASS_START_COL(pass)))>>PNG_PASS_COL_SHIFT(pass)) 2623 2624 /* For the reader row callbacks (both progressive and sequential) it is 2625 * necessary to find the row in the output image given a row in an interlaced 2626 * image, so two more macros: 2627 */ 2628 #define PNG_ROW_FROM_PASS_ROW(y_in, pass) \ 2629 (((y_in)<<PNG_PASS_ROW_SHIFT(pass))+PNG_PASS_START_ROW(pass)) 2630 #define PNG_COL_FROM_PASS_COL(x_in, pass) \ 2631 (((x_in)<<PNG_PASS_COL_SHIFT(pass))+PNG_PASS_START_COL(pass)) 2632 2633 /* Two macros which return a boolean (0 or 1) saying whether the given row 2634 * or column is in a particular pass. These use a common utility macro that 2635 * returns a mask for a given pass - the offset 'off' selects the row or 2636 * column version. The mask has the appropriate bit set for each column in 2637 * the tile. 2638 */ 2639 #define PNG_PASS_MASK(pass,off) ( \ 2640 ((0x110145AF>>(((7-(off))-(pass))<<2)) & 0xF) | \ 2641 ((0x01145AF0>>(((7-(off))-(pass))<<2)) & 0xF0)) 2642 2643 #define PNG_ROW_IN_INTERLACE_PASS(y, pass) \ 2644 ((PNG_PASS_MASK(pass,0) >> ((y)&7)) & 1) 2645 #define PNG_COL_IN_INTERLACE_PASS(x, pass) \ 2646 ((PNG_PASS_MASK(pass,1) >> ((x)&7)) & 1) 2647 2648 #ifdef PNG_READ_COMPOSITE_NODIV_SUPPORTED 2649 /* With these routines we avoid an integer divide, which will be slower on 2650 * most machines. However, it does take more operations than the corresponding 2651 * divide method, so it may be slower on a few RISC systems. There are two 2652 * shifts (by 8 or 16 bits) and an addition, versus a single integer divide. 2653 * 2654 * Note that the rounding factors are NOT supposed to be the same! 128 and 2655 * 32768 are correct for the NODIV code; 127 and 32767 are correct for the 2656 * standard method. 2657 * 2658 * [Optimized code by Greg Roelofs and Mark Adler...blame us for bugs. :-) ] 2659 */ 2660 2661 /* fg and bg should be in `gamma 1.0' space; alpha is the opacity */ 2662 2663 # define png_composite(composite, fg, alpha, bg) \ 2664 { png_uint_16 temp = (png_uint_16)((png_uint_16)(fg) \ 2665 * (png_uint_16)(alpha) \ 2666 + (png_uint_16)(bg)*(png_uint_16)(255 \ 2667 - (png_uint_16)(alpha)) + 128); \ 2668 (composite) = (png_byte)((temp + (temp >> 8)) >> 8); } 2669 2670 # define png_composite_16(composite, fg, alpha, bg) \ 2671 { png_uint_32 temp = (png_uint_32)((png_uint_32)(fg) \ 2672 * (png_uint_32)(alpha) \ 2673 + (png_uint_32)(bg)*(65535 \ 2674 - (png_uint_32)(alpha)) + 32768); \ 2675 (composite) = (png_uint_16)((temp + (temp >> 16)) >> 16); } 2676 2677 #else /* Standard method using integer division */ 2678 2679 # define png_composite(composite, fg, alpha, bg) \ 2680 (composite) = (png_byte)(((png_uint_16)(fg) * (png_uint_16)(alpha) + \ 2681 (png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) + \ 2682 127) / 255) 2683 2684 # define png_composite_16(composite, fg, alpha, bg) \ 2685 (composite) = (png_uint_16)(((png_uint_32)(fg) * (png_uint_32)(alpha) + \ 2686 (png_uint_32)(bg)*(png_uint_32)(65535 - (png_uint_32)(alpha)) + \ 2687 32767) / 65535) 2688 #endif /* PNG_READ_COMPOSITE_NODIV_SUPPORTED */ 2689 2690 #ifdef PNG_READ_INT_FUNCTIONS_SUPPORTED 2691 PNG_EXPORT(201, png_uint_32, png_get_uint_32, (png_const_bytep buf)); 2692 PNG_EXPORT(202, png_uint_16, png_get_uint_16, (png_const_bytep buf)); 2693 PNG_EXPORT(203, png_int_32, png_get_int_32, (png_const_bytep buf)); 2694 #endif 2695 2696 PNG_EXPORT(204, png_uint_32, png_get_uint_31, (png_const_structrp png_ptr, 2697 png_const_bytep buf)); 2698 /* No png_get_int_16 -- may be added if there's a real need for it. */ 2699 2700 /* Place a 32-bit number into a buffer in PNG byte order (big-endian). */ 2701 #ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED 2702 PNG_EXPORT(205, void, png_save_uint_32, (png_bytep buf, png_uint_32 i)); 2703 #endif 2704 #ifdef PNG_SAVE_INT_32_SUPPORTED 2705 PNG_EXPORT(206, void, png_save_int_32, (png_bytep buf, png_int_32 i)); 2706 #endif 2707 2708 /* Place a 16-bit number into a buffer in PNG byte order. 2709 * The parameter is declared unsigned int, not png_uint_16, 2710 * just to avoid potential problems on pre-ANSI C compilers. 2711 */ 2712 #ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED 2713 PNG_EXPORT(207, void, png_save_uint_16, (png_bytep buf, unsigned int i)); 2714 /* No png_save_int_16 -- may be added if there's a real need for it. */ 2715 #endif 2716 2717 #ifdef PNG_USE_READ_MACROS 2718 /* Inline macros to do direct reads of bytes from the input buffer. 2719 * The png_get_int_32() routine assumes we are using two's complement 2720 * format for negative values, which is almost certainly true. 2721 */ 2722 # define PNG_get_uint_32(buf) \ 2723 (((png_uint_32)(*(buf)) << 24) + \ 2724 ((png_uint_32)(*((buf) + 1)) << 16) + \ 2725 ((png_uint_32)(*((buf) + 2)) << 8) + \ 2726 ((png_uint_32)(*((buf) + 3)))) 2727 2728 /* From libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the 2729 * function) incorrectly returned a value of type png_uint_32. 2730 */ 2731 # define PNG_get_uint_16(buf) \ 2732 ((png_uint_16) \ 2733 (((unsigned int)(*(buf)) << 8) + \ 2734 ((unsigned int)(*((buf) + 1))))) 2735 2736 # define PNG_get_int_32(buf) \ 2737 ((png_int_32)((*(buf) & 0x80) \ 2738 ? -((png_int_32)((png_get_uint_32(buf) ^ 0xffffffffL) + 1)) \ 2739 : (png_int_32)png_get_uint_32(buf))) 2740 2741 /* If PNG_PREFIX is defined the same thing as below happens in pnglibconf.h, 2742 * but defining a macro name prefixed with PNG_PREFIX. 2743 */ 2744 # ifndef PNG_PREFIX 2745 # define png_get_uint_32(buf) PNG_get_uint_32(buf) 2746 # define png_get_uint_16(buf) PNG_get_uint_16(buf) 2747 # define png_get_int_32(buf) PNG_get_int_32(buf) 2748 # endif 2749 #else 2750 # ifdef PNG_PREFIX 2751 /* No macros; revert to the (redefined) function */ 2752 # define PNG_get_uint_32 (png_get_uint_32) 2753 # define PNG_get_uint_16 (png_get_uint_16) 2754 # define PNG_get_int_32 (png_get_int_32) 2755 # endif 2756 #endif 2757 2758 /******************************************************************************* 2759 * SIMPLIFIED API 2760 ******************************************************************************* 2761 * 2762 * Please read the documentation in libpng-manual.txt (TODO: write said 2763 * documentation) if you don't understand what follows. 2764 * 2765 * The simplified API hides the details of both libpng and the PNG file format 2766 * itself. It allows PNG files to be read into a very limited number of 2767 * in-memory bitmap formats or to be written from the same formats. If these 2768 * formats do not accomodate your needs then you can, and should, use the more 2769 * sophisticated APIs above - these support a wide variety of in-memory formats 2770 * and a wide variety of sophisticated transformations to those formats as well 2771 * as a wide variety of APIs to manipulate ancillary information. 2772 * 2773 * To read a PNG file using the simplified API: 2774 * 2775 * 1) Declare a 'png_image' structure (see below) on the stack and set the 2776 * version field to PNG_IMAGE_VERSION. 2777 * 2) Call the appropriate png_image_begin_read... function. 2778 * 3) Set the png_image 'format' member to the required sample format. 2779 * 4) Allocate a buffer for the image and, if required, the color-map. 2780 * 5) Call png_image_finish_read to read the image and, if required, the 2781 * color-map into your buffers. 2782 * 2783 * There are no restrictions on the format of the PNG input itself; all valid 2784 * color types, bit depths, and interlace methods are acceptable, and the 2785 * input image is transformed as necessary to the requested in-memory format 2786 * during the png_image_finish_read() step. The only caveat is that if you 2787 * request a color-mapped image from a PNG that is full-color or makes 2788 * complex use of an alpha channel the transformation is extremely lossy and the 2789 * result may look terrible. 2790 * 2791 * To write a PNG file using the simplified API: 2792 * 2793 * 1) Declare a 'png_image' structure on the stack and memset() it to all zero. 2794 * 2) Initialize the members of the structure that describe the image, setting 2795 * the 'format' member to the format of the image samples. 2796 * 3) Call the appropriate png_image_write... function with a pointer to the 2797 * image and, if necessary, the color-map to write the PNG data. 2798 * 2799 * png_image is a structure that describes the in-memory format of an image 2800 * when it is being read or defines the in-memory format of an image that you 2801 * need to write: 2802 */ 2803 #define PNG_IMAGE_VERSION 1 2804 2805 typedef struct png_control *png_controlp; 2806 typedef struct 2807 { 2808 png_controlp opaque; /* Initialize to NULL, free with png_image_free */ 2809 png_uint_32 version; /* Set to PNG_IMAGE_VERSION */ 2810 png_uint_32 width; /* Image width in pixels (columns) */ 2811 png_uint_32 height; /* Image height in pixels (rows) */ 2812 png_uint_32 format; /* Image format as defined below */ 2813 png_uint_32 flags; /* A bit mask containing informational flags */ 2814 png_uint_32 colormap_entries; 2815 /* Number of entries in the color-map */ 2816 2817 /* In the event of an error or warning the following field will be set to a 2818 * non-zero value and the 'message' field will contain a '\0' terminated 2819 * string with the libpng error or warning message. If both warnings and 2820 * an error were encountered, only the error is recorded. If there 2821 * are multiple warnings, only the first one is recorded. 2822 * 2823 * The upper 30 bits of this value are reserved, the low two bits contain 2824 * a value as follows: 2825 */ 2826 # define PNG_IMAGE_WARNING 1 2827 # define PNG_IMAGE_ERROR 2 2828 /* 2829 * The result is a two bit code such that a value more than 1 indicates 2830 * a failure in the API just called: 2831 * 2832 * 0 - no warning or error 2833 * 1 - warning 2834 * 2 - error 2835 * 3 - error preceded by warning 2836 */ 2837 # define PNG_IMAGE_FAILED(png_cntrl) ((((png_cntrl).warning_or_error)&0x03)>1) 2838 2839 png_uint_32 warning_or_error; 2840 2841 char message[64]; 2842 } png_image, *png_imagep; 2843 2844 /* The samples of the image have one to four channels whose components have 2845 * original values in the range 0 to 1.0: 2846 * 2847 * 1: A single gray or luminance channel (G). 2848 * 2: A gray/luminance channel and an alpha channel (GA). 2849 * 3: Three red, green, blue color channels (RGB). 2850 * 4: Three color channels and an alpha channel (RGBA). 2851 * 2852 * The components are encoded in one of two ways: 2853 * 2854 * a) As a small integer, value 0..255, contained in a single byte. For the 2855 * alpha channel the original value is simply value/255. For the color or 2856 * luminance channels the value is encoded according to the sRGB specification 2857 * and matches the 8-bit format expected by typical display devices. 2858 * 2859 * The color/gray channels are not scaled (pre-multiplied) by the alpha 2860 * channel and are suitable for passing to color management software. 2861 * 2862 * b) As a value in the range 0..65535, contained in a 2-byte integer. All 2863 * channels can be converted to the original value by dividing by 65535; all 2864 * channels are linear. Color channels use the RGB encoding (RGB end-points) of 2865 * the sRGB specification. This encoding is identified by the 2866 * PNG_FORMAT_FLAG_LINEAR flag below. 2867 * 2868 * When the simplified API needs to convert between sRGB and linear colorspaces, 2869 * the actual sRGB transfer curve defined in the sRGB specification (see the 2870 * article at http://en.wikipedia.org/wiki/SRGB) is used, not the gamma=1/2.2 2871 * approximation used elsewhere in libpng. 2872 * 2873 * When an alpha channel is present it is expected to denote pixel coverage 2874 * of the color or luminance channels and is returned as an associated alpha 2875 * channel: the color/gray channels are scaled (pre-multiplied) by the alpha 2876 * value. 2877 * 2878 * The samples are either contained directly in the image data, between 1 and 8 2879 * bytes per pixel according to the encoding, or are held in a color-map indexed 2880 * by bytes in the image data. In the case of a color-map the color-map entries 2881 * are individual samples, encoded as above, and the image data has one byte per 2882 * pixel to select the relevant sample from the color-map. 2883 */ 2884 2885 /* PNG_FORMAT_* 2886 * 2887 * #defines to be used in png_image::format. Each #define identifies a 2888 * particular layout of sample data and, if present, alpha values. There are 2889 * separate defines for each of the two component encodings. 2890 * 2891 * A format is built up using single bit flag values. All combinations are 2892 * valid. Formats can be built up from the flag values or you can use one of 2893 * the predefined values below. When testing formats always use the FORMAT_FLAG 2894 * macros to test for individual features - future versions of the library may 2895 * add new flags. 2896 * 2897 * When reading or writing color-mapped images the format should be set to the 2898 * format of the entries in the color-map then png_image_{read,write}_colormap 2899 * called to read or write the color-map and set the format correctly for the 2900 * image data. Do not set the PNG_FORMAT_FLAG_COLORMAP bit directly! 2901 * 2902 * NOTE: libpng can be built with particular features disabled, if you see 2903 * compiler errors because the definition of one of the following flags has been 2904 * compiled out it is because libpng does not have the required support. It is 2905 * possible, however, for the libpng configuration to enable the format on just 2906 * read or just write; in that case you may see an error at run time. You can 2907 * guard against this by checking for the definition of the appropriate 2908 * "_SUPPORTED" macro, one of: 2909 * 2910 * PNG_SIMPLIFIED_{READ,WRITE}_{BGR,AFIRST}_SUPPORTED 2911 */ 2912 #define PNG_FORMAT_FLAG_ALPHA 0x01U /* format with an alpha channel */ 2913 #define PNG_FORMAT_FLAG_COLOR 0x02U /* color format: otherwise grayscale */ 2914 #define PNG_FORMAT_FLAG_LINEAR 0x04U /* 2 byte channels else 1 byte */ 2915 #define PNG_FORMAT_FLAG_COLORMAP 0x08U /* image data is color-mapped */ 2916 2917 #ifdef PNG_FORMAT_BGR_SUPPORTED 2918 # define PNG_FORMAT_FLAG_BGR 0x10U /* BGR colors, else order is RGB */ 2919 #endif 2920 2921 #ifdef PNG_FORMAT_AFIRST_SUPPORTED 2922 # define PNG_FORMAT_FLAG_AFIRST 0x20U /* alpha channel comes first */ 2923 #endif 2924 2925 /* Commonly used formats have predefined macros. 2926 * 2927 * First the single byte (sRGB) formats: 2928 */ 2929 #define PNG_FORMAT_GRAY 0 2930 #define PNG_FORMAT_GA PNG_FORMAT_FLAG_ALPHA 2931 #define PNG_FORMAT_AG (PNG_FORMAT_GA|PNG_FORMAT_FLAG_AFIRST) 2932 #define PNG_FORMAT_RGB PNG_FORMAT_FLAG_COLOR 2933 #define PNG_FORMAT_BGR (PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_BGR) 2934 #define PNG_FORMAT_RGBA (PNG_FORMAT_RGB|PNG_FORMAT_FLAG_ALPHA) 2935 #define PNG_FORMAT_ARGB (PNG_FORMAT_RGBA|PNG_FORMAT_FLAG_AFIRST) 2936 #define PNG_FORMAT_BGRA (PNG_FORMAT_BGR|PNG_FORMAT_FLAG_ALPHA) 2937 #define PNG_FORMAT_ABGR (PNG_FORMAT_BGRA|PNG_FORMAT_FLAG_AFIRST) 2938 2939 /* Then the linear 2-byte formats. When naming these "Y" is used to 2940 * indicate a luminance (gray) channel. 2941 */ 2942 #define PNG_FORMAT_LINEAR_Y PNG_FORMAT_FLAG_LINEAR 2943 #define PNG_FORMAT_LINEAR_Y_ALPHA (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_ALPHA) 2944 #define PNG_FORMAT_LINEAR_RGB (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR) 2945 #define PNG_FORMAT_LINEAR_RGB_ALPHA \ 2946 (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_ALPHA) 2947 2948 /* With color-mapped formats the image data is one byte for each pixel, the byte 2949 * is an index into the color-map which is formatted as above. To obtain a 2950 * color-mapped format it is sufficient just to add the PNG_FOMAT_FLAG_COLORMAP 2951 * to one of the above definitions, or you can use one of the definitions below. 2952 */ 2953 #define PNG_FORMAT_RGB_COLORMAP (PNG_FORMAT_RGB|PNG_FORMAT_FLAG_COLORMAP) 2954 #define PNG_FORMAT_BGR_COLORMAP (PNG_FORMAT_BGR|PNG_FORMAT_FLAG_COLORMAP) 2955 #define PNG_FORMAT_RGBA_COLORMAP (PNG_FORMAT_RGBA|PNG_FORMAT_FLAG_COLORMAP) 2956 #define PNG_FORMAT_ARGB_COLORMAP (PNG_FORMAT_ARGB|PNG_FORMAT_FLAG_COLORMAP) 2957 #define PNG_FORMAT_BGRA_COLORMAP (PNG_FORMAT_BGRA|PNG_FORMAT_FLAG_COLORMAP) 2958 #define PNG_FORMAT_ABGR_COLORMAP (PNG_FORMAT_ABGR|PNG_FORMAT_FLAG_COLORMAP) 2959 2960 /* PNG_IMAGE macros 2961 * 2962 * These are convenience macros to derive information from a png_image 2963 * structure. The PNG_IMAGE_SAMPLE_ macros return values appropriate to the 2964 * actual image sample values - either the entries in the color-map or the 2965 * pixels in the image. The PNG_IMAGE_PIXEL_ macros return corresponding values 2966 * for the pixels and will always return 1 for color-mapped formats. The 2967 * remaining macros return information about the rows in the image and the 2968 * complete image. 2969 * 2970 * NOTE: All the macros that take a png_image::format parameter are compile time 2971 * constants if the format parameter is, itself, a constant. Therefore these 2972 * macros can be used in array declarations and case labels where required. 2973 * Similarly the macros are also pre-processor constants (sizeof is not used) so 2974 * they can be used in #if tests. 2975 * 2976 * First the information about the samples. 2977 */ 2978 #define PNG_IMAGE_SAMPLE_CHANNELS(fmt)\ 2979 (((fmt)&(PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_ALPHA))+1) 2980 /* Return the total number of channels in a given format: 1..4 */ 2981 2982 #define PNG_IMAGE_SAMPLE_COMPONENT_SIZE(fmt)\ 2983 ((((fmt) & PNG_FORMAT_FLAG_LINEAR) >> 2)+1) 2984 /* Return the size in bytes of a single component of a pixel or color-map 2985 * entry (as appropriate) in the image: 1 or 2. 2986 */ 2987 2988 #define PNG_IMAGE_SAMPLE_SIZE(fmt)\ 2989 (PNG_IMAGE_SAMPLE_CHANNELS(fmt) * PNG_IMAGE_SAMPLE_COMPONENT_SIZE(fmt)) 2990 /* This is the size of the sample data for one sample. If the image is 2991 * color-mapped it is the size of one color-map entry (and image pixels are 2992 * one byte in size), otherwise it is the size of one image pixel. 2993 */ 2994 2995 #define PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(fmt)\ 2996 (PNG_IMAGE_SAMPLE_CHANNELS(fmt) * 256) 2997 /* The maximum size of the color-map required by the format expressed in a 2998 * count of components. This can be used to compile-time allocate a 2999 * color-map: 3000 * 3001 * png_uint_16 colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(linear_fmt)]; 3002 * 3003 * png_byte colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(sRGB_fmt)]; 3004 * 3005 * Alternatively use the PNG_IMAGE_COLORMAP_SIZE macro below to use the 3006 * information from one of the png_image_begin_read_ APIs and dynamically 3007 * allocate the required memory. 3008 */ 3009 3010 /* Corresponding information about the pixels */ 3011 #define PNG_IMAGE_PIXEL_(test,fmt)\ 3012 (((fmt)&PNG_FORMAT_FLAG_COLORMAP)?1:test(fmt)) 3013 3014 #define PNG_IMAGE_PIXEL_CHANNELS(fmt)\ 3015 PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_CHANNELS,fmt) 3016 /* The number of separate channels (components) in a pixel; 1 for a 3017 * color-mapped image. 3018 */ 3019 3020 #define PNG_IMAGE_PIXEL_COMPONENT_SIZE(fmt)\ 3021 PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_COMPONENT_SIZE,fmt) 3022 /* The size, in bytes, of each component in a pixel; 1 for a color-mapped 3023 * image. 3024 */ 3025 3026 #define PNG_IMAGE_PIXEL_SIZE(fmt) PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_SIZE,fmt) 3027 /* The size, in bytes, of a complete pixel; 1 for a color-mapped image. */ 3028 3029 /* Information about the whole row, or whole image */ 3030 #define PNG_IMAGE_ROW_STRIDE(image)\ 3031 (PNG_IMAGE_PIXEL_CHANNELS((image).format) * (image).width) 3032 /* Return the total number of components in a single row of the image; this 3033 * is the minimum 'row stride', the minimum count of components between each 3034 * row. For a color-mapped image this is the minimum number of bytes in a 3035 * row. 3036 */ 3037 3038 #define PNG_IMAGE_BUFFER_SIZE(image, row_stride)\ 3039 (PNG_IMAGE_PIXEL_COMPONENT_SIZE((image).format)*(image).height*(row_stride)) 3040 /* Return the size, in bytes, of an image buffer given a png_image and a row 3041 * stride - the number of components to leave space for in each row. 3042 */ 3043 3044 #define PNG_IMAGE_SIZE(image)\ 3045 PNG_IMAGE_BUFFER_SIZE(image, PNG_IMAGE_ROW_STRIDE(image)) 3046 /* Return the size, in bytes, of the image in memory given just a png_image; 3047 * the row stride is the minimum stride required for the image. 3048 */ 3049 3050 #define PNG_IMAGE_COLORMAP_SIZE(image)\ 3051 (PNG_IMAGE_SAMPLE_SIZE((image).format) * (image).colormap_entries) 3052 /* Return the size, in bytes, of the color-map of this image. If the image 3053 * format is not a color-map format this will return a size sufficient for 3054 * 256 entries in the given format; check PNG_FORMAT_FLAG_COLORMAP if 3055 * you don't want to allocate a color-map in this case. 3056 */ 3057 3058 /* PNG_IMAGE_FLAG_* 3059 * 3060 * Flags containing additional information about the image are held in the 3061 * 'flags' field of png_image. 3062 */ 3063 #define PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB 0x01 3064 /* This indicates the the RGB values of the in-memory bitmap do not 3065 * correspond to the red, green and blue end-points defined by sRGB. 3066 */ 3067 3068 #define PNG_IMAGE_FLAG_FAST 0x02 3069 /* On write emphasise speed over compression; the resultant PNG file will be 3070 * larger but will be produced significantly faster, particular for large 3071 * images. Do not use this option for images which will be distributed, only 3072 * used it when producing intermediate files that will be read back in 3073 * repeatedly. For a typical 24-bit image the option will double the read 3074 * speed at the cost of increasing the image size by 25%, however for many 3075 * more compressible images the PNG file can be 10 times larger with only a 3076 * slight speed gain. 3077 */ 3078 3079 #define PNG_IMAGE_FLAG_16BIT_sRGB 0x04 3080 /* On read if the image is a 16-bit per component image and there is no gAMA 3081 * or sRGB chunk assume that the components are sRGB encoded. Notice that 3082 * images output by the simplified API always have gamma information; setting 3083 * this flag only affects the interpretation of 16-bit images from an 3084 * external source. It is recommended that the application expose this flag 3085 * to the user; the user can normally easily recognize the difference between 3086 * linear and sRGB encoding. This flag has no effect on write - the data 3087 * passed to the write APIs must have the correct encoding (as defined 3088 * above.) 3089 * 3090 * If the flag is not set (the default) input 16-bit per component data is 3091 * assumed to be linear. 3092 * 3093 * NOTE: the flag can only be set after the png_image_begin_read_ call, 3094 * because that call initializes the 'flags' field. 3095 */ 3096 3097 #ifdef PNG_SIMPLIFIED_READ_SUPPORTED 3098 /* READ APIs 3099 * --------- 3100 * 3101 * The png_image passed to the read APIs must have been initialized by setting 3102 * the png_controlp field 'opaque' to NULL (or, safer, memset the whole thing.) 3103 */ 3104 #ifdef PNG_STDIO_SUPPORTED 3105 PNG_EXPORT(234, int, png_image_begin_read_from_file, (png_imagep image, 3106 const char *file_name)); 3107 /* The named file is opened for read and the image header is filled in 3108 * from the PNG header in the file. 3109 */ 3110 3111 PNG_EXPORT(235, int, png_image_begin_read_from_stdio, (png_imagep image, 3112 FILE* file)); 3113 /* The PNG header is read from the stdio FILE object. */ 3114 #endif /* PNG_STDIO_SUPPORTED */ 3115 3116 PNG_EXPORT(236, int, png_image_begin_read_from_memory, (png_imagep image, 3117 png_const_voidp memory, png_size_t size)); 3118 /* The PNG header is read from the given memory buffer. */ 3119 3120 PNG_EXPORT(237, int, png_image_finish_read, (png_imagep image, 3121 png_const_colorp background, void *buffer, png_int_32 row_stride, 3122 void *colormap)); 3123 /* Finish reading the image into the supplied buffer and clean up the 3124 * png_image structure. 3125 * 3126 * row_stride is the step, in byte or 2-byte units as appropriate, 3127 * between adjacent rows. A positive stride indicates that the top-most row 3128 * is first in the buffer - the normal top-down arrangement. A negative 3129 * stride indicates that the bottom-most row is first in the buffer. 3130 * 3131 * background need only be supplied if an alpha channel must be removed from 3132 * a png_byte format and the removal is to be done by compositing on a solid 3133 * color; otherwise it may be NULL and any composition will be done directly 3134 * onto the buffer. The value is an sRGB color to use for the background, 3135 * for grayscale output the green channel is used. 3136 * 3137 * background must be supplied when an alpha channel must be removed from a 3138 * single byte color-mapped output format, in other words if: 3139 * 3140 * 1) The original format from png_image_begin_read_from_* had 3141 * PNG_FORMAT_FLAG_ALPHA set. 3142 * 2) The format set by the application does not. 3143 * 3) The format set by the application has PNG_FORMAT_FLAG_COLORMAP set and 3144 * PNG_FORMAT_FLAG_LINEAR *not* set. 3145 * 3146 * For linear output removing the alpha channel is always done by compositing 3147 * on black and background is ignored. 3148 * 3149 * colormap must be supplied when PNG_FORMAT_FLAG_COLORMAP is set. It must 3150 * be at least the size (in bytes) returned by PNG_IMAGE_COLORMAP_SIZE. 3151 * image->colormap_entries will be updated to the actual number of entries 3152 * written to the colormap; this may be less than the original value. 3153 */ 3154 3155 PNG_EXPORT(238, void, png_image_free, (png_imagep image)); 3156 /* Free any data allocated by libpng in image->opaque, setting the pointer to 3157 * NULL. May be called at any time after the structure is initialized. 3158 */ 3159 #endif /* PNG_SIMPLIFIED_READ_SUPPORTED */ 3160 3161 #ifdef PNG_SIMPLIFIED_WRITE_SUPPORTED 3162 #ifdef PNG_STDIO_SUPPORTED 3163 /* WRITE APIS 3164 * ---------- 3165 * For write you must initialize a png_image structure to describe the image to 3166 * be written. To do this use memset to set the whole structure to 0 then 3167 * initialize fields describing your image. 3168 * 3169 * version: must be set to PNG_IMAGE_VERSION 3170 * opaque: must be initialized to NULL 3171 * width: image width in pixels 3172 * height: image height in rows 3173 * format: the format of the data (image and color-map) you wish to write 3174 * flags: set to 0 unless one of the defined flags applies; set 3175 * PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB for color format images where the RGB 3176 * values do not correspond to the colors in sRGB. 3177 * colormap_entries: set to the number of entries in the color-map (0 to 256) 3178 */ 3179 PNG_EXPORT(239, int, png_image_write_to_file, (png_imagep image, 3180 const char *file, int convert_to_8bit, const void *buffer, 3181 png_int_32 row_stride, const void *colormap)); 3182 /* Write the image to the named file. */ 3183 3184 PNG_EXPORT(240, int, png_image_write_to_stdio, (png_imagep image, FILE *file, 3185 int convert_to_8_bit, const void *buffer, png_int_32 row_stride, 3186 const void *colormap)); 3187 /* Write the image to the given (FILE*). */ 3188 3189 /* With both write APIs if image is in one of the linear formats with 16-bit 3190 * data then setting convert_to_8_bit will cause the output to be an 8-bit PNG 3191 * gamma encoded according to the sRGB specification, otherwise a 16-bit linear 3192 * encoded PNG file is written. 3193 * 3194 * With color-mapped data formats the colormap parameter point to a color-map 3195 * with at least image->colormap_entries encoded in the specified format. If 3196 * the format is linear the written PNG color-map will be converted to sRGB 3197 * regardless of the convert_to_8_bit flag. 3198 * 3199 * With all APIs row_stride is handled as in the read APIs - it is the spacing 3200 * from one row to the next in component sized units (1 or 2 bytes) and if 3201 * negative indicates a bottom-up row layout in the buffer. 3202 * 3203 * Note that the write API does not support interlacing or sub-8-bit pixels. 3204 */ 3205 #endif /* PNG_STDIO_SUPPORTED */ 3206 #endif /* PNG_SIMPLIFIED_WRITE_SUPPORTED */ 3207 /******************************************************************************* 3208 * END OF SIMPLIFIED API 3209 ******************************************************************************/ 3210 3211 #ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED 3212 PNG_EXPORT(242, void, png_set_check_for_invalid_index, 3213 (png_structrp png_ptr, int allowed)); 3214 # ifdef PNG_GET_PALETTE_MAX_SUPPORTED 3215 PNG_EXPORT(243, int, png_get_palette_max, (png_const_structp png_ptr, 3216 png_const_infop info_ptr)); 3217 # endif 3218 #endif /* CHECK_FOR_INVALID_INDEX */ 3219 3220 /******************************************************************************* 3221 * IMPLEMENTATION OPTIONS 3222 ******************************************************************************* 3223 * 3224 * Support for arbitrary implementation-specific optimizations. The API allows 3225 * particular options to be turned on or off. 'Option' is the number of the 3226 * option and 'onoff' is 0 (off) or non-0 (on). The value returned is given 3227 * by the PNG_OPTION_ defines below. 3228 * 3229 * HARDWARE: normally hardware capabilites, such as the Intel SSE instructions, 3230 * are detected at run time, however sometimes it may be impossible 3231 * to do this in user mode, in which case it is necessary to discover 3232 * the capabilities in an OS specific way. Such capabilities are 3233 * listed here when libpng has support for them and must be turned 3234 * ON by the application if present. 3235 * 3236 * SOFTWARE: sometimes software optimizations actually result in performance 3237 * decrease on some architectures or systems, or with some sets of 3238 * PNG images. 'Software' options allow such optimizations to be 3239 * selected at run time. 3240 */ 3241 #ifdef PNG_SET_OPTION_SUPPORTED 3242 #ifdef PNG_ARM_NEON_API_SUPPORTED 3243 # define PNG_ARM_NEON 0 /* HARDWARE: ARM Neon SIMD instructions supported */ 3244 #endif 3245 #define PNG_MAXIMUM_INFLATE_WINDOW 2 /* SOFTWARE: force maximum window */ 3246 #define PNG_OPTION_NEXT 4 /* Next option - numbers must be even */ 3247 3248 /* Return values: NOTE: there are four values and 'off' is *not* zero */ 3249 #define PNG_OPTION_UNSET 0 /* Unset - defaults to off */ 3250 #define PNG_OPTION_INVALID 1 /* Option number out of range */ 3251 #define PNG_OPTION_OFF 2 3252 #define PNG_OPTION_ON 3 3253 3254 PNG_EXPORT(244, int, png_set_option, (png_structrp png_ptr, int option, 3255 int onoff)); 3256 #endif 3257 3258 /******************************************************************************* 3259 * END OF HARDWARE OPTIONS 3260 ******************************************************************************/ 3261 3262 /* Maintainer: Put new public prototypes here ^, in libpng.3, and project 3263 * defs, scripts/pnglibconf.h, and scripts/pnglibconf.h.prebuilt 3264 */ 3265 3266 /* The last ordinal number (this is the *last* one already used; the next 3267 * one to use is one more than this.) Maintainer, remember to add an entry to 3268 * scripts/symbols.def as well. 3269 */ 3270 #ifdef PNG_EXPORT_LAST_ORDINAL 3271 PNG_EXPORT_LAST_ORDINAL(244); 3272 #endif 3273 3274 #ifdef __cplusplus 3275 } 3276 #endif 3277 3278 #endif /* PNG_VERSION_INFO_ONLY */ 3279 /* Do not put anything past this line */ 3280 #endif /* PNG_H */ 3281
