1 2 /* png.h - header file for PNG reference library 3 * 4 * libpng version 1.6.9 - February 6, 2014 5 * Copyright (c) 1998-2013 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 1.6.9 - February 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 * 196 * Henceforth the source version will match the shared-library major 197 * and minor numbers; the shared-library major version number will be 198 * used for changes in backward compatibility, as it is intended. The 199 * PNG_LIBPNG_VER macro, which is not used within libpng but is available 200 * for applications, is an unsigned integer of the form xyyzz corresponding 201 * to the source version x.y.z (leading zeros in y and z). Beta versions 202 * were given the previous public release number plus a letter, until 203 * version 1.0.6j; from then on they were given the upcoming public 204 * release number plus "betaNN" or "rcNN". 205 * 206 * Binary incompatibility exists only when applications make direct access 207 * to the info_ptr or png_ptr members through png.h, and the compiled 208 * application is loaded with a different version of the library. 209 * 210 * DLLNUM will change each time there are forward or backward changes 211 * in binary compatibility (e.g., when a new feature is added). 212 * 213 * See libpng-manual.txt or libpng.3 for more information. The PNG 214 * specification is available as a W3C Recommendation and as an ISO 215 * Specification, <http://www.w3.org/TR/2003/REC-PNG-20031110/ 216 */ 217 218 /* 219 * COPYRIGHT NOTICE, DISCLAIMER, and LICENSE: 220 * 221 * If you modify libpng you may insert additional notices immediately following 222 * this sentence. 223 * 224 * This code is released under the libpng license. 225 * 226 * libpng versions 1.2.6, August 15, 2004, through 1.6.9, February 6, 2014, are 227 * Copyright (c) 2004, 2006-2013 Glenn Randers-Pehrson, and are 228 * distributed according to the same disclaimer and license as libpng-1.2.5 229 * with the following individual added to the list of Contributing Authors: 230 * 231 * Cosmin Truta 232 * 233 * libpng versions 1.0.7, July 1, 2000, through 1.2.5, October 3, 2002, are 234 * Copyright (c) 2000-2002 Glenn Randers-Pehrson, and are 235 * distributed according to the same disclaimer and license as libpng-1.0.6 236 * with the following individuals added to the list of Contributing Authors: 237 * 238 * Simon-Pierre Cadieux 239 * Eric S. Raymond 240 * Gilles Vollant 241 * 242 * and with the following additions to the disclaimer: 243 * 244 * There is no warranty against interference with your enjoyment of the 245 * library or against infringement. There is no warranty that our 246 * efforts or the library will fulfill any of your particular purposes 247 * or needs. This library is provided with all faults, and the entire 248 * risk of satisfactory quality, performance, accuracy, and effort is with 249 * the user. 250 * 251 * libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are 252 * Copyright (c) 1998, 1999, 2000 Glenn Randers-Pehrson, and are 253 * distributed according to the same disclaimer and license as libpng-0.96, 254 * with the following individuals added to the list of Contributing Authors: 255 * 256 * Tom Lane 257 * Glenn Randers-Pehrson 258 * Willem van Schaik 259 * 260 * libpng versions 0.89, June 1996, through 0.96, May 1997, are 261 * Copyright (c) 1996, 1997 Andreas Dilger 262 * Distributed according to the same disclaimer and license as libpng-0.88, 263 * with the following individuals added to the list of Contributing Authors: 264 * 265 * John Bowler 266 * Kevin Bracey 267 * Sam Bushell 268 * Magnus Holmgren 269 * Greg Roelofs 270 * Tom Tanner 271 * 272 * libpng versions 0.5, May 1995, through 0.88, January 1996, are 273 * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. 274 * 275 * For the purposes of this copyright and license, "Contributing Authors" 276 * is defined as the following set of individuals: 277 * 278 * Andreas Dilger 279 * Dave Martindale 280 * Guy Eric Schalnat 281 * Paul Schmidt 282 * Tim Wegner 283 * 284 * The PNG Reference Library is supplied "AS IS". The Contributing Authors 285 * and Group 42, Inc. disclaim all warranties, expressed or implied, 286 * including, without limitation, the warranties of merchantability and of 287 * fitness for any purpose. The Contributing Authors and Group 42, Inc. 288 * assume no liability for direct, indirect, incidental, special, exemplary, 289 * or consequential damages, which may result from the use of the PNG 290 * Reference Library, even if advised of the possibility of such damage. 291 * 292 * Permission is hereby granted to use, copy, modify, and distribute this 293 * source code, or portions hereof, for any purpose, without fee, subject 294 * to the following restrictions: 295 * 296 * 1. The origin of this source code must not be misrepresented. 297 * 298 * 2. Altered versions must be plainly marked as such and must not 299 * be misrepresented as being the original source. 300 * 301 * 3. This Copyright notice may not be removed or altered from 302 * any source or altered source distribution. 303 * 304 * The Contributing Authors and Group 42, Inc. specifically permit, without 305 * fee, and encourage the use of this source code as a component to 306 * supporting the PNG file format in commercial products. If you use this 307 * source code in a product, acknowledgment is not required but would be 308 * appreciated. 309 */ 310 311 /* 312 * A "png_get_copyright" function is available, for convenient use in "about" 313 * boxes and the like: 314 * 315 * printf("%s", png_get_copyright(NULL)); 316 * 317 * Also, the PNG logo (in PNG format, of course) is supplied in the 318 * files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31). 319 */ 320 321 /* 322 * Libpng is OSI Certified Open Source Software. OSI Certified is a 323 * certification mark of the Open Source Initiative. 324 */ 325 326 /* 327 * The contributing authors would like to thank all those who helped 328 * with testing, bug fixes, and patience. This wouldn't have been 329 * possible without all of you. 330 * 331 * Thanks to Frank J. T. Wojcik for helping with the documentation. 332 */ 333 334 /* 335 * Y2K compliance in libpng: 336 * ========================= 337 * 338 * February 6, 2014 339 * 340 * Since the PNG Development group is an ad-hoc body, we can't make 341 * an official declaration. 342 * 343 * This is your unofficial assurance that libpng from version 0.71 and 344 * upward through 1.6.9 are Y2K compliant. It is my belief that 345 * earlier versions were also Y2K compliant. 346 * 347 * Libpng only has two year fields. One is a 2-byte unsigned integer 348 * that will hold years up to 65535. The other, which is deprecated, 349 * holds the date in text format, and will hold years up to 9999. 350 * 351 * The integer is 352 * "png_uint_16 year" in png_time_struct. 353 * 354 * The string is 355 * "char time_buffer[29]" in png_struct. This is no longer used 356 * in libpng-1.6.x and will be removed from libpng-1.7.0. 357 * 358 * There are seven time-related functions: 359 * png.c: png_convert_to_rfc_1123_buffer() in png.c 360 * (formerly png_convert_to_rfc_1123() prior to libpng-1.5.x and 361 * png_convert_to_rfc_1152() in error prior to libpng-0.98) 362 * png_convert_from_struct_tm() in pngwrite.c, called in pngwrite.c 363 * png_convert_from_time_t() in pngwrite.c 364 * png_get_tIME() in pngget.c 365 * png_handle_tIME() in pngrutil.c, called in pngread.c 366 * png_set_tIME() in pngset.c 367 * png_write_tIME() in pngwutil.c, called in pngwrite.c 368 * 369 * All handle dates properly in a Y2K environment. The 370 * png_convert_from_time_t() function calls gmtime() to convert from system 371 * clock time, which returns (year - 1900), which we properly convert to 372 * the full 4-digit year. There is a possibility that libpng applications 373 * are not passing 4-digit years into the png_convert_to_rfc_1123_buffer() 374 * function, or that they are incorrectly passing only a 2-digit year 375 * instead of "year - 1900" into the png_convert_from_struct_tm() function, 376 * but this is not under our control. The libpng documentation has always 377 * stated that it works with 4-digit years, and the APIs have been 378 * documented as such. 379 * 380 * The tIME chunk itself is also Y2K compliant. It uses a 2-byte unsigned 381 * integer to hold the year, and can hold years as large as 65535. 382 * 383 * zlib, upon which libpng depends, is also Y2K compliant. It contains 384 * no date-related code. 385 * 386 * Glenn Randers-Pehrson 387 * libpng maintainer 388 * PNG Development Group 389 */ 390 391 #ifndef PNG_H 392 #define PNG_H 393 394 /* This is not the place to learn how to use libpng. The file libpng-manual.txt 395 * describes how to use libpng, and the file example.c summarizes it 396 * with some code on which to build. This file is useful for looking 397 * at the actual function definitions and structure components. 398 * 399 * If you just need to read a PNG file and don't want to read the documentation 400 * skip to the end of this file and read the section entitled 'simplified API'. 401 */ 402 403 /* Version information for png.h - this should match the version in png.c */ 404 #define PNG_LIBPNG_VER_STRING "1.6.9" 405 #define PNG_HEADER_VERSION_STRING \ 406 " libpng version 1.6.9 - February 6, 2014\n" 407 408 #define PNG_LIBPNG_VER_SONUM 16 409 #define PNG_LIBPNG_VER_DLLNUM 16 410 411 /* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */ 412 #define PNG_LIBPNG_VER_MAJOR 1 413 #define PNG_LIBPNG_VER_MINOR 6 414 #define PNG_LIBPNG_VER_RELEASE 9 415 416 /* This should match the numeric part of the final component of 417 * PNG_LIBPNG_VER_STRING, omitting any leading zero: 418 */ 419 420 #define PNG_LIBPNG_VER_BUILD 0 421 422 /* Release Status */ 423 #define PNG_LIBPNG_BUILD_ALPHA 1 424 #define PNG_LIBPNG_BUILD_BETA 2 425 #define PNG_LIBPNG_BUILD_RC 3 426 #define PNG_LIBPNG_BUILD_STABLE 4 427 #define PNG_LIBPNG_BUILD_RELEASE_STATUS_MASK 7 428 429 /* Release-Specific Flags */ 430 #define PNG_LIBPNG_BUILD_PATCH 8 /* Can be OR'ed with 431 PNG_LIBPNG_BUILD_STABLE only */ 432 #define PNG_LIBPNG_BUILD_PRIVATE 16 /* Cannot be OR'ed with 433 PNG_LIBPNG_BUILD_SPECIAL */ 434 #define PNG_LIBPNG_BUILD_SPECIAL 32 /* Cannot be OR'ed with 435 PNG_LIBPNG_BUILD_PRIVATE */ 436 437 #define PNG_LIBPNG_BUILD_BASE_TYPE PNG_LIBPNG_BUILD_STABLE 438 439 /* Careful here. At one time, Guy wanted to use 082, but that would be octal. 440 * We must not include leading zeros. 441 * Versions 0.7 through 1.0.0 were in the range 0 to 100 here (only 442 * version 1.0.0 was mis-numbered 100 instead of 10000). From 443 * version 1.0.1 it's xxyyzz, where x=major, y=minor, z=release 444 */ 445 #define PNG_LIBPNG_VER 10609 /* 1.6.9 */ 446 447 /* Library configuration: these options cannot be changed after 448 * the library has been built. 449 */ 450 #ifndef PNGLCONF_H 451 /* If pnglibconf.h is missing, you can 452 * copy scripts/pnglibconf.h.prebuilt to pnglibconf.h 453 */ 454 # include "pnglibconf.h" 455 #endif 456 457 #ifndef PNG_VERSION_INFO_ONLY 458 /* Machine specific configuration. */ 459 # include "pngconf.h" 460 #endif 461 462 /* 463 * Added at libpng-1.2.8 464 * 465 * Ref MSDN: Private as priority over Special 466 * VS_FF_PRIVATEBUILD File *was not* built using standard release 467 * procedures. If this value is given, the StringFileInfo block must 468 * contain a PrivateBuild string. 469 * 470 * VS_FF_SPECIALBUILD File *was* built by the original company using 471 * standard release procedures but is a variation of the standard 472 * file of the same version number. If this value is given, the 473 * StringFileInfo block must contain a SpecialBuild string. 474 */ 475 476 #ifdef PNG_USER_PRIVATEBUILD /* From pnglibconf.h */ 477 # define PNG_LIBPNG_BUILD_TYPE \ 478 (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_PRIVATE) 479 #else 480 # ifdef PNG_LIBPNG_SPECIALBUILD 481 # define PNG_LIBPNG_BUILD_TYPE \ 482 (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_SPECIAL) 483 # else 484 # define PNG_LIBPNG_BUILD_TYPE (PNG_LIBPNG_BUILD_BASE_TYPE) 485 # endif 486 #endif 487 488 #ifndef PNG_VERSION_INFO_ONLY 489 490 /* Inhibit C++ name-mangling for libpng functions but not for system calls. */ 491 #ifdef __cplusplus 492 extern "C" { 493 #endif /* __cplusplus */ 494 495 /* Version information for C files, stored in png.c. This had better match 496 * the version above. 497 */ 498 #define png_libpng_ver png_get_header_ver(NULL) 499 500 /* This file is arranged in several sections: 501 * 502 * 1. Any configuration options that can be specified by for the application 503 * code when it is built. (Build time configuration is in pnglibconf.h) 504 * 2. Type definitions (base types are defined in pngconf.h), structure 505 * definitions. 506 * 3. Exported library functions. 507 * 4. Simplified API. 508 * 509 * The library source code has additional files (principally pngpriv.h) that 510 * allow configuration of the library. 511 */ 512 /* Section 1: run time configuration 513 * See pnglibconf.h for build time configuration 514 * 515 * Run time configuration allows the application to choose between 516 * implementations of certain arithmetic APIs. The default is set 517 * at build time and recorded in pnglibconf.h, but it is safe to 518 * override these (and only these) settings. Note that this won't 519 * change what the library does, only application code, and the 520 * settings can (and probably should) be made on a per-file basis 521 * by setting the #defines before including png.h 522 * 523 * Use macros to read integers from PNG data or use the exported 524 * functions? 525 * PNG_USE_READ_MACROS: use the macros (see below) Note that 526 * the macros evaluate their argument multiple times. 527 * PNG_NO_USE_READ_MACROS: call the relevant library function. 528 * 529 * Use the alternative algorithm for compositing alpha samples that 530 * does not use division? 531 * PNG_READ_COMPOSITE_NODIV_SUPPORTED: use the 'no division' 532 * algorithm. 533 * PNG_NO_READ_COMPOSITE_NODIV: use the 'division' algorithm. 534 * 535 * How to handle benign errors if PNG_ALLOW_BENIGN_ERRORS is 536 * false? 537 * PNG_ALLOW_BENIGN_ERRORS: map calls to the benign error 538 * APIs to png_warning. 539 * Otherwise the calls are mapped to png_error. 540 */ 541 542 /* Section 2: type definitions, including structures and compile time 543 * constants. 544 * See pngconf.h for base types that vary by machine/system 545 */ 546 547 /* This triggers a compiler error in png.c, if png.c and png.h 548 * do not agree upon the version number. 549 */ 550 typedef char* png_libpng_version_1_6_9; 551 552 /* Basic control structions. Read libpng-manual.txt or libpng.3 for more info. 553 * 554 * png_struct is the cache of information used while reading or writing a single 555 * PNG file. One of these is always required, although the simplified API 556 * (below) hides the creation and destruction of it. 557 */ 558 typedef struct png_struct_def png_struct; 559 typedef const png_struct * png_const_structp; 560 typedef png_struct * png_structp; 561 typedef png_struct * * png_structpp; 562 563 /* png_info contains information read from or to be written to a PNG file. One 564 * or more of these must exist while reading or creating a PNG file. The 565 * information is not used by libpng during read but is used to control what 566 * gets written when a PNG file is created. "png_get_" function calls read 567 * information during read and "png_set_" functions calls write information 568 * when creating a PNG. 569 * been moved into a separate header file that is not accessible to 570 * applications. Read libpng-manual.txt or libpng.3 for more info. 571 */ 572 typedef struct png_info_def png_info; 573 typedef png_info * png_infop; 574 typedef const png_info * png_const_infop; 575 typedef png_info * * png_infopp; 576 577 /* Types with names ending 'p' are pointer types. The corresponding types with 578 * names ending 'rp' are identical pointer types except that the pointer is 579 * marked 'restrict', which means that it is the only pointer to the object 580 * passed to the function. Applications should not use the 'restrict' types; 581 * it is always valid to pass 'p' to a pointer with a function argument of the 582 * corresponding 'rp' type. Different compilers have different rules with 583 * regard to type matching in the presence of 'restrict'. For backward 584 * compatibility libpng callbacks never have 'restrict' in their parameters and, 585 * consequentially, writing portable application code is extremely difficult if 586 * an attempt is made to use 'restrict'. 587 */ 588 typedef png_struct * PNG_RESTRICT png_structrp; 589 typedef const png_struct * PNG_RESTRICT png_const_structrp; 590 typedef png_info * PNG_RESTRICT png_inforp; 591 typedef const png_info * PNG_RESTRICT png_const_inforp; 592 593 /* Three color definitions. The order of the red, green, and blue, (and the 594 * exact size) is not important, although the size of the fields need to 595 * be png_byte or png_uint_16 (as defined below). 596 */ 597 typedef struct png_color_struct 598 { 599 png_byte red; 600 png_byte green; 601 png_byte blue; 602 } png_color; 603 typedef png_color * png_colorp; 604 typedef const png_color * png_const_colorp; 605 typedef png_color * * png_colorpp; 606 607 typedef struct png_color_16_struct 608 { 609 png_byte index; /* used for palette files */ 610 png_uint_16 red; /* for use in red green blue files */ 611 png_uint_16 green; 612 png_uint_16 blue; 613 png_uint_16 gray; /* for use in grayscale files */ 614 } png_color_16; 615 typedef png_color_16 * png_color_16p; 616 typedef const png_color_16 * png_const_color_16p; 617 typedef png_color_16 * * png_color_16pp; 618 619 typedef struct png_color_8_struct 620 { 621 png_byte red; /* for use in red green blue files */ 622 png_byte green; 623 png_byte blue; 624 png_byte gray; /* for use in grayscale files */ 625 png_byte alpha; /* for alpha channel files */ 626 } png_color_8; 627 typedef png_color_8 * png_color_8p; 628 typedef const png_color_8 * png_const_color_8p; 629 typedef png_color_8 * * png_color_8pp; 630 631 /* 632 * The following two structures are used for the in-core representation 633 * of sPLT chunks. 634 */ 635 typedef struct png_sPLT_entry_struct 636 { 637 png_uint_16 red; 638 png_uint_16 green; 639 png_uint_16 blue; 640 png_uint_16 alpha; 641 png_uint_16 frequency; 642 } png_sPLT_entry; 643 typedef png_sPLT_entry * png_sPLT_entryp; 644 typedef const png_sPLT_entry * png_const_sPLT_entryp; 645 typedef png_sPLT_entry * * png_sPLT_entrypp; 646 647 /* When the depth of the sPLT palette is 8 bits, the color and alpha samples 648 * occupy the LSB of their respective members, and the MSB of each member 649 * is zero-filled. The frequency member always occupies the full 16 bits. 650 */ 651 652 typedef struct png_sPLT_struct 653 { 654 png_charp name; /* palette name */ 655 png_byte depth; /* depth of palette samples */ 656 png_sPLT_entryp entries; /* palette entries */ 657 png_int_32 nentries; /* number of palette entries */ 658 } png_sPLT_t; 659 typedef png_sPLT_t * png_sPLT_tp; 660 typedef const png_sPLT_t * png_const_sPLT_tp; 661 typedef png_sPLT_t * * png_sPLT_tpp; 662 663 #ifdef PNG_TEXT_SUPPORTED 664 /* png_text holds the contents of a text/ztxt/itxt chunk in a PNG file, 665 * and whether that contents is compressed or not. The "key" field 666 * points to a regular zero-terminated C string. The "text" fields can be a 667 * regular C string, an empty string, or a NULL pointer. 668 * However, the structure returned by png_get_text() will always contain 669 * the "text" field as a regular zero-terminated C string (possibly 670 * empty), never a NULL pointer, so it can be safely used in printf() and 671 * other string-handling functions. Note that the "itxt_length", "lang", and 672 * "lang_key" members of the structure only exist when the library is built 673 * with iTXt chunk support. Prior to libpng-1.4.0 the library was built by 674 * default without iTXt support. Also note that when iTXt *is* supported, 675 * the "lang" and "lang_key" fields contain NULL pointers when the 676 * "compression" field contains * PNG_TEXT_COMPRESSION_NONE or 677 * PNG_TEXT_COMPRESSION_zTXt. Note that the "compression value" is not the 678 * same as what appears in the PNG tEXt/zTXt/iTXt chunk's "compression flag" 679 * which is always 0 or 1, or its "compression method" which is always 0. 680 */ 681 typedef struct png_text_struct 682 { 683 int compression; /* compression value: 684 -1: tEXt, none 685 0: zTXt, deflate 686 1: iTXt, none 687 2: iTXt, deflate */ 688 png_charp key; /* keyword, 1-79 character description of "text" */ 689 png_charp text; /* comment, may be an empty string (ie "") 690 or a NULL pointer */ 691 png_size_t text_length; /* length of the text string */ 692 png_size_t itxt_length; /* length of the itxt string */ 693 png_charp lang; /* language code, 0-79 characters 694 or a NULL pointer */ 695 png_charp lang_key; /* keyword translated UTF-8 string, 0 or more 696 chars or a NULL pointer */ 697 } png_text; 698 typedef png_text * png_textp; 699 typedef const png_text * png_const_textp; 700 typedef png_text * * png_textpp; 701 #endif 702 703 /* Supported compression types for text in PNG files (tEXt, and zTXt). 704 * The values of the PNG_TEXT_COMPRESSION_ defines should NOT be changed. */ 705 #define PNG_TEXT_COMPRESSION_NONE_WR -3 706 #define PNG_TEXT_COMPRESSION_zTXt_WR -2 707 #define PNG_TEXT_COMPRESSION_NONE -1 708 #define PNG_TEXT_COMPRESSION_zTXt 0 709 #define PNG_ITXT_COMPRESSION_NONE 1 710 #define PNG_ITXT_COMPRESSION_zTXt 2 711 #define PNG_TEXT_COMPRESSION_LAST 3 /* Not a valid value */ 712 713 /* png_time is a way to hold the time in an machine independent way. 714 * Two conversions are provided, both from time_t and struct tm. There 715 * is no portable way to convert to either of these structures, as far 716 * as I know. If you know of a portable way, send it to me. As a side 717 * note - PNG has always been Year 2000 compliant! 718 */ 719 typedef struct png_time_struct 720 { 721 png_uint_16 year; /* full year, as in, 1995 */ 722 png_byte month; /* month of year, 1 - 12 */ 723 png_byte day; /* day of month, 1 - 31 */ 724 png_byte hour; /* hour of day, 0 - 23 */ 725 png_byte minute; /* minute of hour, 0 - 59 */ 726 png_byte second; /* second of minute, 0 - 60 (for leap seconds) */ 727 } png_time; 728 typedef png_time * png_timep; 729 typedef const png_time * png_const_timep; 730 typedef png_time * * png_timepp; 731 732 #if defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED) ||\ 733 defined(PNG_USER_CHUNKS_SUPPORTED) 734 /* png_unknown_chunk is a structure to hold queued chunks for which there is 735 * no specific support. The idea is that we can use this to queue 736 * up private chunks for output even though the library doesn't actually 737 * know about their semantics. 738 * 739 * The data in the structure is set by libpng on read and used on write. 740 */ 741 typedef struct png_unknown_chunk_t 742 { 743 png_byte name[5]; /* Textual chunk name with '\0' terminator */ 744 png_byte *data; /* Data, should not be modified on read! */ 745 png_size_t size; 746 747 /* On write 'location' must be set using the flag values listed below. 748 * Notice that on read it is set by libpng however the values stored have 749 * more bits set than are listed below. Always treat the value as a 750 * bitmask. On write set only one bit - setting multiple bits may cause the 751 * chunk to be written in multiple places. 752 */ 753 png_byte location; /* mode of operation at read time */ 754 } 755 png_unknown_chunk; 756 757 typedef png_unknown_chunk * png_unknown_chunkp; 758 typedef const png_unknown_chunk * png_const_unknown_chunkp; 759 typedef png_unknown_chunk * * png_unknown_chunkpp; 760 #endif 761 762 /* Flag values for the unknown chunk location byte. */ 763 #define PNG_HAVE_IHDR 0x01 764 #define PNG_HAVE_PLTE 0x02 765 #define PNG_AFTER_IDAT 0x08 766 767 /* Maximum positive integer used in PNG is (2^31)-1 */ 768 #define PNG_UINT_31_MAX ((png_uint_32)0x7fffffffL) 769 #define PNG_UINT_32_MAX ((png_uint_32)(-1)) 770 #define PNG_SIZE_MAX ((png_size_t)(-1)) 771 772 /* These are constants for fixed point values encoded in the 773 * PNG specification manner (x100000) 774 */ 775 #define PNG_FP_1 100000 776 #define PNG_FP_HALF 50000 777 #define PNG_FP_MAX ((png_fixed_point)0x7fffffffL) 778 #define PNG_FP_MIN (-PNG_FP_MAX) 779 780 /* These describe the color_type field in png_info. */ 781 /* color type masks */ 782 #define PNG_COLOR_MASK_PALETTE 1 783 #define PNG_COLOR_MASK_COLOR 2 784 #define PNG_COLOR_MASK_ALPHA 4 785 786 /* color types. Note that not all combinations are legal */ 787 #define PNG_COLOR_TYPE_GRAY 0 788 #define PNG_COLOR_TYPE_PALETTE (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE) 789 #define PNG_COLOR_TYPE_RGB (PNG_COLOR_MASK_COLOR) 790 #define PNG_COLOR_TYPE_RGB_ALPHA (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_ALPHA) 791 #define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA) 792 /* aliases */ 793 #define PNG_COLOR_TYPE_RGBA PNG_COLOR_TYPE_RGB_ALPHA 794 #define PNG_COLOR_TYPE_GA PNG_COLOR_TYPE_GRAY_ALPHA 795 796 /* This is for compression type. PNG 1.0-1.2 only define the single type. */ 797 #define PNG_COMPRESSION_TYPE_BASE 0 /* Deflate method 8, 32K window */ 798 #define PNG_COMPRESSION_TYPE_DEFAULT PNG_COMPRESSION_TYPE_BASE 799 800 /* This is for filter type. PNG 1.0-1.2 only define the single type. */ 801 #define PNG_FILTER_TYPE_BASE 0 /* Single row per-byte filtering */ 802 #define PNG_INTRAPIXEL_DIFFERENCING 64 /* Used only in MNG datastreams */ 803 #define PNG_FILTER_TYPE_DEFAULT PNG_FILTER_TYPE_BASE 804 805 /* These are for the interlacing type. These values should NOT be changed. */ 806 #define PNG_INTERLACE_NONE 0 /* Non-interlaced image */ 807 #define PNG_INTERLACE_ADAM7 1 /* Adam7 interlacing */ 808 #define PNG_INTERLACE_LAST 2 /* Not a valid value */ 809 810 /* These are for the oFFs chunk. These values should NOT be changed. */ 811 #define PNG_OFFSET_PIXEL 0 /* Offset in pixels */ 812 #define PNG_OFFSET_MICROMETER 1 /* Offset in micrometers (1/10^6 meter) */ 813 #define PNG_OFFSET_LAST 2 /* Not a valid value */ 814 815 /* These are for the pCAL chunk. These values should NOT be changed. */ 816 #define PNG_EQUATION_LINEAR 0 /* Linear transformation */ 817 #define PNG_EQUATION_BASE_E 1 /* Exponential base e transform */ 818 #define PNG_EQUATION_ARBITRARY 2 /* Arbitrary base exponential transform */ 819 #define PNG_EQUATION_HYPERBOLIC 3 /* Hyperbolic sine transformation */ 820 #define PNG_EQUATION_LAST 4 /* Not a valid value */ 821 822 /* These are for the sCAL chunk. These values should NOT be changed. */ 823 #define PNG_SCALE_UNKNOWN 0 /* unknown unit (image scale) */ 824 #define PNG_SCALE_METER 1 /* meters per pixel */ 825 #define PNG_SCALE_RADIAN 2 /* radians per pixel */ 826 #define PNG_SCALE_LAST 3 /* Not a valid value */ 827 828 /* These are for the pHYs chunk. These values should NOT be changed. */ 829 #define PNG_RESOLUTION_UNKNOWN 0 /* pixels/unknown unit (aspect ratio) */ 830 #define PNG_RESOLUTION_METER 1 /* pixels/meter */ 831 #define PNG_RESOLUTION_LAST 2 /* Not a valid value */ 832 833 /* These are for the sRGB chunk. These values should NOT be changed. */ 834 #define PNG_sRGB_INTENT_PERCEPTUAL 0 835 #define PNG_sRGB_INTENT_RELATIVE 1 836 #define PNG_sRGB_INTENT_SATURATION 2 837 #define PNG_sRGB_INTENT_ABSOLUTE 3 838 #define PNG_sRGB_INTENT_LAST 4 /* Not a valid value */ 839 840 /* This is for text chunks */ 841 #define PNG_KEYWORD_MAX_LENGTH 79 842 843 /* Maximum number of entries in PLTE/sPLT/tRNS arrays */ 844 #define PNG_MAX_PALETTE_LENGTH 256 845 846 /* These determine if an ancillary chunk's data has been successfully read 847 * from the PNG header, or if the application has filled in the corresponding 848 * data in the info_struct to be written into the output file. The values 849 * of the PNG_INFO_<chunk> defines should NOT be changed. 850 */ 851 #define PNG_INFO_gAMA 0x0001 852 #define PNG_INFO_sBIT 0x0002 853 #define PNG_INFO_cHRM 0x0004 854 #define PNG_INFO_PLTE 0x0008 855 #define PNG_INFO_tRNS 0x0010 856 #define PNG_INFO_bKGD 0x0020 857 #define PNG_INFO_hIST 0x0040 858 #define PNG_INFO_pHYs 0x0080 859 #define PNG_INFO_oFFs 0x0100 860 #define PNG_INFO_tIME 0x0200 861 #define PNG_INFO_pCAL 0x0400 862 #define PNG_INFO_sRGB 0x0800 /* GR-P, 0.96a */ 863 #define PNG_INFO_iCCP 0x1000 /* ESR, 1.0.6 */ 864 #define PNG_INFO_sPLT 0x2000 /* ESR, 1.0.6 */ 865 #define PNG_INFO_sCAL 0x4000 /* ESR, 1.0.6 */ 866 #define PNG_INFO_IDAT 0x8000 /* ESR, 1.0.6 */ 867 868 /* This is used for the transformation routines, as some of them 869 * change these values for the row. It also should enable using 870 * the routines for other purposes. 871 */ 872 typedef struct png_row_info_struct 873 { 874 png_uint_32 width; /* width of row */ 875 png_size_t rowbytes; /* number of bytes in row */ 876 png_byte color_type; /* color type of row */ 877 png_byte bit_depth; /* bit depth of row */ 878 png_byte channels; /* number of channels (1, 2, 3, or 4) */ 879 png_byte pixel_depth; /* bits per pixel (depth * channels) */ 880 } png_row_info; 881 882 typedef png_row_info * png_row_infop; 883 typedef png_row_info * * png_row_infopp; 884 885 /* These are the function types for the I/O functions and for the functions 886 * that allow the user to override the default I/O functions with his or her 887 * own. The png_error_ptr type should match that of user-supplied warning 888 * and error functions, while the png_rw_ptr type should match that of the 889 * user read/write data functions. Note that the 'write' function must not 890 * modify the buffer it is passed. The 'read' function, on the other hand, is 891 * expected to return the read data in the buffer. 892 */ 893 typedef PNG_CALLBACK(void, *png_error_ptr, (png_structp, png_const_charp)); 894 typedef PNG_CALLBACK(void, *png_rw_ptr, (png_structp, png_bytep, png_size_t)); 895 typedef PNG_CALLBACK(void, *png_flush_ptr, (png_structp)); 896 typedef PNG_CALLBACK(void, *png_read_status_ptr, (png_structp, png_uint_32, 897 int)); 898 typedef PNG_CALLBACK(void, *png_write_status_ptr, (png_structp, png_uint_32, 899 int)); 900 901 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED 902 typedef PNG_CALLBACK(void, *png_progressive_info_ptr, (png_structp, png_infop)); 903 typedef PNG_CALLBACK(void, *png_progressive_end_ptr, (png_structp, png_infop)); 904 905 /* The following callback receives png_uint_32 row_number, int pass for the 906 * png_bytep data of the row. When transforming an interlaced image the 907 * row number is the row number within the sub-image of the interlace pass, so 908 * the value will increase to the height of the sub-image (not the full image) 909 * then reset to 0 for the next pass. 910 * 911 * Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to 912 * find the output pixel (x,y) given an interlaced sub-image pixel 913 * (row,col,pass). (See below for these macros.) 914 */ 915 typedef PNG_CALLBACK(void, *png_progressive_row_ptr, (png_structp, png_bytep, 916 png_uint_32, int)); 917 #endif 918 919 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \ 920 defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) 921 typedef PNG_CALLBACK(void, *png_user_transform_ptr, (png_structp, png_row_infop, 922 png_bytep)); 923 #endif 924 925 #ifdef PNG_USER_CHUNKS_SUPPORTED 926 typedef PNG_CALLBACK(int, *png_user_chunk_ptr, (png_structp, 927 png_unknown_chunkp)); 928 #endif 929 #ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED 930 /* not used anywhere */ 931 /* typedef PNG_CALLBACK(void, *png_unknown_chunk_ptr, (png_structp)); */ 932 #endif 933 934 #ifdef PNG_SETJMP_SUPPORTED 935 /* This must match the function definition in <setjmp.h>, and the application 936 * must include this before png.h to obtain the definition of jmp_buf. The 937 * function is required to be PNG_NORETURN, but this is not checked. If the 938 * function does return the application will crash via an abort() or similar 939 * system level call. 940 * 941 * If you get a warning here while building the library you may need to make 942 * changes to ensure that pnglibconf.h records the calling convention used by 943 * your compiler. This may be very difficult - try using a different compiler 944 * to build the library! 945 */ 946 PNG_FUNCTION(void, (PNGCAPI *png_longjmp_ptr), PNGARG((jmp_buf, int)), typedef); 947 #endif 948 949 /* Transform masks for the high-level interface */ 950 #define PNG_TRANSFORM_IDENTITY 0x0000 /* read and write */ 951 #define PNG_TRANSFORM_STRIP_16 0x0001 /* read only */ 952 #define PNG_TRANSFORM_STRIP_ALPHA 0x0002 /* read only */ 953 #define PNG_TRANSFORM_PACKING 0x0004 /* read and write */ 954 #define PNG_TRANSFORM_PACKSWAP 0x0008 /* read and write */ 955 #define PNG_TRANSFORM_EXPAND 0x0010 /* read only */ 956 #define PNG_TRANSFORM_INVERT_MONO 0x0020 /* read and write */ 957 #define PNG_TRANSFORM_SHIFT 0x0040 /* read and write */ 958 #define PNG_TRANSFORM_BGR 0x0080 /* read and write */ 959 #define PNG_TRANSFORM_SWAP_ALPHA 0x0100 /* read and write */ 960 #define PNG_TRANSFORM_SWAP_ENDIAN 0x0200 /* read and write */ 961 #define PNG_TRANSFORM_INVERT_ALPHA 0x0400 /* read and write */ 962 #define PNG_TRANSFORM_STRIP_FILLER 0x0800 /* write only */ 963 /* Added to libpng-1.2.34 */ 964 #define PNG_TRANSFORM_STRIP_FILLER_BEFORE PNG_TRANSFORM_STRIP_FILLER 965 #define PNG_TRANSFORM_STRIP_FILLER_AFTER 0x1000 /* write only */ 966 /* Added to libpng-1.4.0 */ 967 #define PNG_TRANSFORM_GRAY_TO_RGB 0x2000 /* read only */ 968 /* Added to libpng-1.5.4 */ 969 #define PNG_TRANSFORM_EXPAND_16 0x4000 /* read only */ 970 #define PNG_TRANSFORM_SCALE_16 0x8000 /* read only */ 971 972 /* Flags for MNG supported features */ 973 #define PNG_FLAG_MNG_EMPTY_PLTE 0x01 974 #define PNG_FLAG_MNG_FILTER_64 0x04 975 #define PNG_ALL_MNG_FEATURES 0x05 976 977 /* NOTE: prior to 1.5 these functions had no 'API' style declaration, 978 * this allowed the zlib default functions to be used on Windows 979 * platforms. In 1.5 the zlib default malloc (which just calls malloc and 980 * ignores the first argument) should be completely compatible with the 981 * following. 982 */ 983 typedef PNG_CALLBACK(png_voidp, *png_malloc_ptr, (png_structp, 984 png_alloc_size_t)); 985 typedef PNG_CALLBACK(void, *png_free_ptr, (png_structp, png_voidp)); 986 987 /* Section 3: exported functions 988 * Here are the function definitions most commonly used. This is not 989 * the place to find out how to use libpng. See libpng-manual.txt for the 990 * full explanation, see example.c for the summary. This just provides 991 * a simple one line description of the use of each function. 992 * 993 * The PNG_EXPORT() and PNG_EXPORTA() macros used below are defined in 994 * pngconf.h and in the *.dfn files in the scripts directory. 995 * 996 * PNG_EXPORT(ordinal, type, name, (args)); 997 * 998 * ordinal: ordinal that is used while building 999 * *.def files. The ordinal value is only 1000 * relevant when preprocessing png.h with 1001 * the *.dfn files for building symbol table 1002 * entries, and are removed by pngconf.h. 1003 * type: return type of the function 1004 * name: function name 1005 * args: function arguments, with types 1006 * 1007 * When we wish to append attributes to a function prototype we use 1008 * the PNG_EXPORTA() macro instead. 1009 * 1010 * PNG_EXPORTA(ordinal, type, name, (args), attributes); 1011 * 1012 * ordinal, type, name, and args: same as in PNG_EXPORT(). 1013 * attributes: function attributes 1014 */ 1015 1016 /* Returns the version number of the library */ 1017 PNG_EXPORT(1, png_uint_32, png_access_version_number, (void)); 1018 1019 /* Tell lib we have already handled the first <num_bytes> magic bytes. 1020 * Handling more than 8 bytes from the beginning of the file is an error. 1021 */ 1022 PNG_EXPORT(2, void, png_set_sig_bytes, (png_structrp png_ptr, int num_bytes)); 1023 1024 /* Check sig[start] through sig[start + num_to_check - 1] to see if it's a 1025 * PNG file. Returns zero if the supplied bytes match the 8-byte PNG 1026 * signature, and non-zero otherwise. Having num_to_check == 0 or 1027 * start > 7 will always fail (ie return non-zero). 1028 */ 1029 PNG_EXPORT(3, int, png_sig_cmp, (png_const_bytep sig, png_size_t start, 1030 png_size_t num_to_check)); 1031 1032 /* Simple signature checking function. This is the same as calling 1033 * png_check_sig(sig, n) := !png_sig_cmp(sig, 0, n). 1034 */ 1035 #define png_check_sig(sig, n) !png_sig_cmp((sig), 0, (n)) 1036 1037 /* Allocate and initialize png_ptr struct for reading, and any other memory. */ 1038 PNG_EXPORTA(4, png_structp, png_create_read_struct, 1039 (png_const_charp user_png_ver, png_voidp error_ptr, 1040 png_error_ptr error_fn, png_error_ptr warn_fn), 1041 PNG_ALLOCATED); 1042 1043 /* Allocate and initialize png_ptr struct for writing, and any other memory */ 1044 PNG_EXPORTA(5, png_structp, png_create_write_struct, 1045 (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn, 1046 png_error_ptr warn_fn), 1047 PNG_ALLOCATED); 1048 1049 PNG_EXPORT(6, png_size_t, png_get_compression_buffer_size, 1050 (png_const_structrp png_ptr)); 1051 1052 PNG_EXPORT(7, void, png_set_compression_buffer_size, (png_structrp png_ptr, 1053 png_size_t size)); 1054 1055 /* Moved from pngconf.h in 1.4.0 and modified to ensure setjmp/longjmp 1056 * match up. 1057 */ 1058 #ifdef PNG_SETJMP_SUPPORTED 1059 /* This function returns the jmp_buf built in to *png_ptr. It must be 1060 * supplied with an appropriate 'longjmp' function to use on that jmp_buf 1061 * unless the default error function is overridden in which case NULL is 1062 * acceptable. The size of the jmp_buf is checked against the actual size 1063 * allocated by the library - the call will return NULL on a mismatch 1064 * indicating an ABI mismatch. 1065 */ 1066 PNG_EXPORT(8, jmp_buf*, png_set_longjmp_fn, (png_structrp png_ptr, 1067 png_longjmp_ptr longjmp_fn, size_t jmp_buf_size)); 1068 # define png_jmpbuf(png_ptr) \ 1069 (*png_set_longjmp_fn((png_ptr), longjmp, (sizeof (jmp_buf)))) 1070 #else 1071 # define png_jmpbuf(png_ptr) \ 1072 (LIBPNG_WAS_COMPILED_WITH__PNG_NO_SETJMP) 1073 #endif 1074 /* This function should be used by libpng applications in place of 1075 * longjmp(png_ptr->jmpbuf, val). If longjmp_fn() has been set, it 1076 * will use it; otherwise it will call PNG_ABORT(). This function was 1077 * added in libpng-1.5.0. 1078 */ 1079 PNG_EXPORTA(9, void, png_longjmp, (png_const_structrp png_ptr, int val), 1080 PNG_NORETURN); 1081 1082 #ifdef PNG_READ_SUPPORTED 1083 /* Reset the compression stream */ 1084 PNG_EXPORTA(10, int, png_reset_zstream, (png_structrp png_ptr), PNG_DEPRECATED); 1085 #endif 1086 1087 /* New functions added in libpng-1.0.2 (not enabled by default until 1.2.0) */ 1088 #ifdef PNG_USER_MEM_SUPPORTED 1089 PNG_EXPORTA(11, png_structp, png_create_read_struct_2, 1090 (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn, 1091 png_error_ptr warn_fn, 1092 png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn), 1093 PNG_ALLOCATED); 1094 PNG_EXPORTA(12, png_structp, png_create_write_struct_2, 1095 (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn, 1096 png_error_ptr warn_fn, 1097 png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn), 1098 PNG_ALLOCATED); 1099 #endif 1100 1101 /* Write the PNG file signature. */ 1102 PNG_EXPORT(13, void, png_write_sig, (png_structrp png_ptr)); 1103 1104 /* Write a PNG chunk - size, type, (optional) data, CRC. */ 1105 PNG_EXPORT(14, void, png_write_chunk, (png_structrp png_ptr, png_const_bytep 1106 chunk_name, png_const_bytep data, png_size_t length)); 1107 1108 /* Write the start of a PNG chunk - length and chunk name. */ 1109 PNG_EXPORT(15, void, png_write_chunk_start, (png_structrp png_ptr, 1110 png_const_bytep chunk_name, png_uint_32 length)); 1111 1112 /* Write the data of a PNG chunk started with png_write_chunk_start(). */ 1113 PNG_EXPORT(16, void, png_write_chunk_data, (png_structrp png_ptr, 1114 png_const_bytep data, png_size_t length)); 1115 1116 /* Finish a chunk started with png_write_chunk_start() (includes CRC). */ 1117 PNG_EXPORT(17, void, png_write_chunk_end, (png_structrp png_ptr)); 1118 1119 /* Allocate and initialize the info structure */ 1120 PNG_EXPORTA(18, png_infop, png_create_info_struct, (png_const_structrp png_ptr), 1121 PNG_ALLOCATED); 1122 1123 /* DEPRECATED: this function allowed init structures to be created using the 1124 * default allocation method (typically malloc). Use is deprecated in 1.6.0 and 1125 * the API will be removed in the future. 1126 */ 1127 PNG_EXPORTA(19, void, png_info_init_3, (png_infopp info_ptr, 1128 png_size_t png_info_struct_size), PNG_DEPRECATED); 1129 1130 /* Writes all the PNG information before the image. */ 1131 PNG_EXPORT(20, void, png_write_info_before_PLTE, 1132 (png_structrp png_ptr, png_const_inforp info_ptr)); 1133 PNG_EXPORT(21, void, png_write_info, 1134 (png_structrp png_ptr, png_const_inforp info_ptr)); 1135 1136 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED 1137 /* Read the information before the actual image data. */ 1138 PNG_EXPORT(22, void, png_read_info, 1139 (png_structrp png_ptr, png_inforp info_ptr)); 1140 #endif 1141 1142 #ifdef PNG_TIME_RFC1123_SUPPORTED 1143 /* Convert to a US string format: there is no localization support in this 1144 * routine. The original implementation used a 29 character buffer in 1145 * png_struct, this will be removed in future versions. 1146 */ 1147 #if PNG_LIBPNG_VER < 10700 1148 /* To do: remove this from libpng17 (and from libpng17/png.c and pngstruct.h) */ 1149 PNG_EXPORTA(23, png_const_charp, png_convert_to_rfc1123, (png_structrp png_ptr, 1150 png_const_timep ptime),PNG_DEPRECATED); 1151 #endif 1152 PNG_EXPORT(241, int, png_convert_to_rfc1123_buffer, (char out[29], 1153 png_const_timep ptime)); 1154 #endif 1155 1156 #ifdef PNG_CONVERT_tIME_SUPPORTED 1157 /* Convert from a struct tm to png_time */ 1158 PNG_EXPORT(24, void, png_convert_from_struct_tm, (png_timep ptime, 1159 const struct tm * ttime)); 1160 1161 /* Convert from time_t to png_time. Uses gmtime() */ 1162 PNG_EXPORT(25, void, png_convert_from_time_t, (png_timep ptime, time_t ttime)); 1163 #endif /* PNG_CONVERT_tIME_SUPPORTED */ 1164 1165 #ifdef PNG_READ_EXPAND_SUPPORTED 1166 /* Expand data to 24-bit RGB, or 8-bit grayscale, with alpha if available. */ 1167 PNG_EXPORT(26, void, png_set_expand, (png_structrp png_ptr)); 1168 PNG_EXPORT(27, void, png_set_expand_gray_1_2_4_to_8, (png_structrp png_ptr)); 1169 PNG_EXPORT(28, void, png_set_palette_to_rgb, (png_structrp png_ptr)); 1170 PNG_EXPORT(29, void, png_set_tRNS_to_alpha, (png_structrp png_ptr)); 1171 #endif 1172 1173 #ifdef PNG_READ_EXPAND_16_SUPPORTED 1174 /* Expand to 16-bit channels, forces conversion of palette to RGB and expansion 1175 * of a tRNS chunk if present. 1176 */ 1177 PNG_EXPORT(221, void, png_set_expand_16, (png_structrp png_ptr)); 1178 #endif 1179 1180 #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED) 1181 /* Use blue, green, red order for pixels. */ 1182 PNG_EXPORT(30, void, png_set_bgr, (png_structrp png_ptr)); 1183 #endif 1184 1185 #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED 1186 /* Expand the grayscale to 24-bit RGB if necessary. */ 1187 PNG_EXPORT(31, void, png_set_gray_to_rgb, (png_structrp png_ptr)); 1188 #endif 1189 1190 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED 1191 /* Reduce RGB to grayscale. */ 1192 #define PNG_ERROR_ACTION_NONE 1 1193 #define PNG_ERROR_ACTION_WARN 2 1194 #define PNG_ERROR_ACTION_ERROR 3 1195 #define PNG_RGB_TO_GRAY_DEFAULT (-1)/*for red/green coefficients*/ 1196 1197 PNG_FP_EXPORT(32, void, png_set_rgb_to_gray, (png_structrp png_ptr, 1198 int error_action, double red, double green)) 1199 PNG_FIXED_EXPORT(33, void, png_set_rgb_to_gray_fixed, (png_structrp png_ptr, 1200 int error_action, png_fixed_point red, png_fixed_point green)) 1201 1202 PNG_EXPORT(34, png_byte, png_get_rgb_to_gray_status, (png_const_structrp 1203 png_ptr)); 1204 #endif 1205 1206 #ifdef PNG_BUILD_GRAYSCALE_PALETTE_SUPPORTED 1207 PNG_EXPORT(35, void, png_build_grayscale_palette, (int bit_depth, 1208 png_colorp palette)); 1209 #endif 1210 1211 #ifdef PNG_READ_ALPHA_MODE_SUPPORTED 1212 /* How the alpha channel is interpreted - this affects how the color channels of 1213 * a PNG file are returned when an alpha channel, or tRNS chunk in a palette 1214 * file, is present. 1215 * 1216 * This has no effect on the way pixels are written into a PNG output 1217 * datastream. The color samples in a PNG datastream are never premultiplied 1218 * with the alpha samples. 1219 * 1220 * The default is to return data according to the PNG specification: the alpha 1221 * channel is a linear measure of the contribution of the pixel to the 1222 * corresponding composited pixel. The gamma encoded color channels must be 1223 * scaled according to the contribution and to do this it is necessary to undo 1224 * the encoding, scale the color values, perform the composition and reencode 1225 * the values. This is the 'PNG' mode. 1226 * 1227 * The alternative is to 'associate' the alpha with the color information by 1228 * storing color channel values that have been scaled by the alpha. The 1229 * advantage is that the color channels can be resampled (the image can be 1230 * scaled) in this form. The disadvantage is that normal practice is to store 1231 * linear, not (gamma) encoded, values and this requires 16-bit channels for 1232 * still images rather than the 8-bit channels that are just about sufficient if 1233 * gamma encoding is used. In addition all non-transparent pixel values, 1234 * including completely opaque ones, must be gamma encoded to produce the final 1235 * image. This is the 'STANDARD', 'ASSOCIATED' or 'PREMULTIPLIED' mode (the 1236 * latter being the two common names for associated alpha color channels.) 1237 * 1238 * Since it is not necessary to perform arithmetic on opaque color values so 1239 * long as they are not to be resampled and are in the final color space it is 1240 * possible to optimize the handling of alpha by storing the opaque pixels in 1241 * the PNG format (adjusted for the output color space) while storing partially 1242 * opaque pixels in the standard, linear, format. The accuracy required for 1243 * standard alpha composition is relatively low, because the pixels are 1244 * isolated, therefore typically the accuracy loss in storing 8-bit linear 1245 * values is acceptable. (This is not true if the alpha channel is used to 1246 * simulate transparency over large areas - use 16 bits or the PNG mode in 1247 * this case!) This is the 'OPTIMIZED' mode. For this mode a pixel is 1248 * treated as opaque only if the alpha value is equal to the maximum value. 1249 * 1250 * The final choice is to gamma encode the alpha channel as well. This is 1251 * broken because, in practice, no implementation that uses this choice 1252 * correctly undoes the encoding before handling alpha composition. Use this 1253 * choice only if other serious errors in the software or hardware you use 1254 * mandate it; the typical serious error is for dark halos to appear around 1255 * opaque areas of the composited PNG image because of arithmetic overflow. 1256 * 1257 * The API function png_set_alpha_mode specifies which of these choices to use 1258 * with an enumerated 'mode' value and the gamma of the required output: 1259 */ 1260 #define PNG_ALPHA_PNG 0 /* according to the PNG standard */ 1261 #define PNG_ALPHA_STANDARD 1 /* according to Porter/Duff */ 1262 #define PNG_ALPHA_ASSOCIATED 1 /* as above; this is the normal practice */ 1263 #define PNG_ALPHA_PREMULTIPLIED 1 /* as above */ 1264 #define PNG_ALPHA_OPTIMIZED 2 /* 'PNG' for opaque pixels, else 'STANDARD' */ 1265 #define PNG_ALPHA_BROKEN 3 /* the alpha channel is gamma encoded */ 1266 1267 PNG_FP_EXPORT(227, void, png_set_alpha_mode, (png_structrp png_ptr, int mode, 1268 double output_gamma)) 1269 PNG_FIXED_EXPORT(228, void, png_set_alpha_mode_fixed, (png_structrp png_ptr, 1270 int mode, png_fixed_point output_gamma)) 1271 #endif 1272 1273 #if defined(PNG_GAMMA_SUPPORTED) || defined(PNG_READ_ALPHA_MODE_SUPPORTED) 1274 /* The output_gamma value is a screen gamma in libpng terminology: it expresses 1275 * how to decode the output values, not how they are encoded. The values used 1276 * correspond to the normal numbers used to describe the overall gamma of a 1277 * computer display system; for example 2.2 for an sRGB conformant system. The 1278 * values are scaled by 100000 in the _fixed version of the API (so 220000 for 1279 * sRGB.) 1280 * 1281 * The inverse of the value is always used to provide a default for the PNG file 1282 * encoding if it has no gAMA chunk and if png_set_gamma() has not been called 1283 * to override the PNG gamma information. 1284 * 1285 * When the ALPHA_OPTIMIZED mode is selected the output gamma is used to encode 1286 * opaque pixels however pixels with lower alpha values are not encoded, 1287 * regardless of the output gamma setting. 1288 * 1289 * When the standard Porter Duff handling is requested with mode 1 the output 1290 * encoding is set to be linear and the output_gamma value is only relevant 1291 * as a default for input data that has no gamma information. The linear output 1292 * encoding will be overridden if png_set_gamma() is called - the results may be 1293 * highly unexpected! 1294 * 1295 * The following numbers are derived from the sRGB standard and the research 1296 * behind it. sRGB is defined to be approximated by a PNG gAMA chunk value of 1297 * 0.45455 (1/2.2) for PNG. The value implicitly includes any viewing 1298 * correction required to take account of any differences in the color 1299 * environment of the original scene and the intended display environment; the 1300 * value expresses how to *decode* the image for display, not how the original 1301 * data was *encoded*. 1302 * 1303 * sRGB provides a peg for the PNG standard by defining a viewing environment. 1304 * sRGB itself, and earlier TV standards, actually use a more complex transform 1305 * (a linear portion then a gamma 2.4 power law) than PNG can express. (PNG is 1306 * limited to simple power laws.) By saying that an image for direct display on 1307 * an sRGB conformant system should be stored with a gAMA chunk value of 45455 1308 * (11.3.3.2 and 11.3.3.5 of the ISO PNG specification) the PNG specification 1309 * makes it possible to derive values for other display systems and 1310 * environments. 1311 * 1312 * The Mac value is deduced from the sRGB based on an assumption that the actual 1313 * extra viewing correction used in early Mac display systems was implemented as 1314 * a power 1.45 lookup table. 1315 * 1316 * Any system where a programmable lookup table is used or where the behavior of 1317 * the final display device characteristics can be changed requires system 1318 * specific code to obtain the current characteristic. However this can be 1319 * difficult and most PNG gamma correction only requires an approximate value. 1320 * 1321 * By default, if png_set_alpha_mode() is not called, libpng assumes that all 1322 * values are unencoded, linear, values and that the output device also has a 1323 * linear characteristic. This is only very rarely correct - it is invariably 1324 * better to call png_set_alpha_mode() with PNG_DEFAULT_sRGB than rely on the 1325 * default if you don't know what the right answer is! 1326 * 1327 * The special value PNG_GAMMA_MAC_18 indicates an older Mac system (pre Mac OS 1328 * 10.6) which used a correction table to implement a somewhat lower gamma on an 1329 * otherwise sRGB system. 1330 * 1331 * Both these values are reserved (not simple gamma values) in order to allow 1332 * more precise correction internally in the future. 1333 * 1334 * NOTE: the following values can be passed to either the fixed or floating 1335 * point APIs, but the floating point API will also accept floating point 1336 * values. 1337 */ 1338 #define PNG_DEFAULT_sRGB -1 /* sRGB gamma and color space */ 1339 #define PNG_GAMMA_MAC_18 -2 /* Old Mac '1.8' gamma and color space */ 1340 #define PNG_GAMMA_sRGB 220000 /* Television standards--matches sRGB gamma */ 1341 #define PNG_GAMMA_LINEAR PNG_FP_1 /* Linear */ 1342 #endif 1343 1344 /* The following are examples of calls to png_set_alpha_mode to achieve the 1345 * required overall gamma correction and, where necessary, alpha 1346 * premultiplication. 1347 * 1348 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB); 1349 * This is the default libpng handling of the alpha channel - it is not 1350 * pre-multiplied into the color components. In addition the call states 1351 * that the output is for a sRGB system and causes all PNG files without gAMA 1352 * chunks to be assumed to be encoded using sRGB. 1353 * 1354 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC); 1355 * In this case the output is assumed to be something like an sRGB conformant 1356 * display preceeded by a power-law lookup table of power 1.45. This is how 1357 * early Mac systems behaved. 1358 * 1359 * png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_GAMMA_LINEAR); 1360 * This is the classic Jim Blinn approach and will work in academic 1361 * environments where everything is done by the book. It has the shortcoming 1362 * of assuming that input PNG data with no gamma information is linear - this 1363 * is unlikely to be correct unless the PNG files where generated locally. 1364 * Most of the time the output precision will be so low as to show 1365 * significant banding in dark areas of the image. 1366 * 1367 * png_set_expand_16(pp); 1368 * png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_DEFAULT_sRGB); 1369 * This is a somewhat more realistic Jim Blinn inspired approach. PNG files 1370 * are assumed to have the sRGB encoding if not marked with a gamma value and 1371 * the output is always 16 bits per component. This permits accurate scaling 1372 * and processing of the data. If you know that your input PNG files were 1373 * generated locally you might need to replace PNG_DEFAULT_sRGB with the 1374 * correct value for your system. 1375 * 1376 * png_set_alpha_mode(pp, PNG_ALPHA_OPTIMIZED, PNG_DEFAULT_sRGB); 1377 * If you just need to composite the PNG image onto an existing background 1378 * and if you control the code that does this you can use the optimization 1379 * setting. In this case you just copy completely opaque pixels to the 1380 * output. For pixels that are not completely transparent (you just skip 1381 * those) you do the composition math using png_composite or png_composite_16 1382 * below then encode the resultant 8-bit or 16-bit values to match the output 1383 * encoding. 1384 * 1385 * Other cases 1386 * If neither the PNG nor the standard linear encoding work for you because 1387 * of the software or hardware you use then you have a big problem. The PNG 1388 * case will probably result in halos around the image. The linear encoding 1389 * will probably result in a washed out, too bright, image (it's actually too 1390 * contrasty.) Try the ALPHA_OPTIMIZED mode above - this will probably 1391 * substantially reduce the halos. Alternatively try: 1392 * 1393 * png_set_alpha_mode(pp, PNG_ALPHA_BROKEN, PNG_DEFAULT_sRGB); 1394 * This option will also reduce the halos, but there will be slight dark 1395 * halos round the opaque parts of the image where the background is light. 1396 * In the OPTIMIZED mode the halos will be light halos where the background 1397 * is dark. Take your pick - the halos are unavoidable unless you can get 1398 * your hardware/software fixed! (The OPTIMIZED approach is slightly 1399 * faster.) 1400 * 1401 * When the default gamma of PNG files doesn't match the output gamma. 1402 * If you have PNG files with no gamma information png_set_alpha_mode allows 1403 * you to provide a default gamma, but it also sets the ouput gamma to the 1404 * matching value. If you know your PNG files have a gamma that doesn't 1405 * match the output you can take advantage of the fact that 1406 * png_set_alpha_mode always sets the output gamma but only sets the PNG 1407 * default if it is not already set: 1408 * 1409 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB); 1410 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC); 1411 * The first call sets both the default and the output gamma values, the 1412 * second call overrides the output gamma without changing the default. This 1413 * is easier than achieving the same effect with png_set_gamma. You must use 1414 * PNG_ALPHA_PNG for the first call - internal checking in png_set_alpha will 1415 * fire if more than one call to png_set_alpha_mode and png_set_background is 1416 * made in the same read operation, however multiple calls with PNG_ALPHA_PNG 1417 * are ignored. 1418 */ 1419 1420 #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED 1421 PNG_EXPORT(36, void, png_set_strip_alpha, (png_structrp png_ptr)); 1422 #endif 1423 1424 #if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \ 1425 defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED) 1426 PNG_EXPORT(37, void, png_set_swap_alpha, (png_structrp png_ptr)); 1427 #endif 1428 1429 #if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \ 1430 defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED) 1431 PNG_EXPORT(38, void, png_set_invert_alpha, (png_structrp png_ptr)); 1432 #endif 1433 1434 #if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED) 1435 /* Add a filler byte to 8-bit Gray or 24-bit RGB images. */ 1436 PNG_EXPORT(39, void, png_set_filler, (png_structrp png_ptr, png_uint_32 filler, 1437 int flags)); 1438 /* The values of the PNG_FILLER_ defines should NOT be changed */ 1439 # define PNG_FILLER_BEFORE 0 1440 # define PNG_FILLER_AFTER 1 1441 /* Add an alpha byte to 8-bit Gray or 24-bit RGB images. */ 1442 PNG_EXPORT(40, void, png_set_add_alpha, (png_structrp png_ptr, 1443 png_uint_32 filler, int flags)); 1444 #endif /* PNG_READ_FILLER_SUPPORTED || PNG_WRITE_FILLER_SUPPORTED */ 1445 1446 #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED) 1447 /* Swap bytes in 16-bit depth files. */ 1448 PNG_EXPORT(41, void, png_set_swap, (png_structrp png_ptr)); 1449 #endif 1450 1451 #if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED) 1452 /* Use 1 byte per pixel in 1, 2, or 4-bit depth files. */ 1453 PNG_EXPORT(42, void, png_set_packing, (png_structrp png_ptr)); 1454 #endif 1455 1456 #if defined(PNG_READ_PACKSWAP_SUPPORTED) || \ 1457 defined(PNG_WRITE_PACKSWAP_SUPPORTED) 1458 /* Swap packing order of pixels in bytes. */ 1459 PNG_EXPORT(43, void, png_set_packswap, (png_structrp png_ptr)); 1460 #endif 1461 1462 #if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED) 1463 /* Converts files to legal bit depths. */ 1464 PNG_EXPORT(44, void, png_set_shift, (png_structrp png_ptr, png_const_color_8p 1465 true_bits)); 1466 #endif 1467 1468 #if defined(PNG_READ_INTERLACING_SUPPORTED) || \ 1469 defined(PNG_WRITE_INTERLACING_SUPPORTED) 1470 /* Have the code handle the interlacing. Returns the number of passes. 1471 * MUST be called before png_read_update_info or png_start_read_image, 1472 * otherwise it will not have the desired effect. Note that it is still 1473 * necessary to call png_read_row or png_read_rows png_get_image_height 1474 * times for each pass. 1475 */ 1476 PNG_EXPORT(45, int, png_set_interlace_handling, (png_structrp png_ptr)); 1477 #endif 1478 1479 #if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED) 1480 /* Invert monochrome files */ 1481 PNG_EXPORT(46, void, png_set_invert_mono, (png_structrp png_ptr)); 1482 #endif 1483 1484 #ifdef PNG_READ_BACKGROUND_SUPPORTED 1485 /* Handle alpha and tRNS by replacing with a background color. Prior to 1486 * libpng-1.5.4 this API must not be called before the PNG file header has been 1487 * read. Doing so will result in unexpected behavior and possible warnings or 1488 * errors if the PNG file contains a bKGD chunk. 1489 */ 1490 PNG_FP_EXPORT(47, void, png_set_background, (png_structrp png_ptr, 1491 png_const_color_16p background_color, int background_gamma_code, 1492 int need_expand, double background_gamma)) 1493 PNG_FIXED_EXPORT(215, void, png_set_background_fixed, (png_structrp png_ptr, 1494 png_const_color_16p background_color, int background_gamma_code, 1495 int need_expand, png_fixed_point background_gamma)) 1496 #endif 1497 #ifdef PNG_READ_BACKGROUND_SUPPORTED 1498 # define PNG_BACKGROUND_GAMMA_UNKNOWN 0 1499 # define PNG_BACKGROUND_GAMMA_SCREEN 1 1500 # define PNG_BACKGROUND_GAMMA_FILE 2 1501 # define PNG_BACKGROUND_GAMMA_UNIQUE 3 1502 #endif 1503 1504 #ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED 1505 /* Scale a 16-bit depth file down to 8-bit, accurately. */ 1506 PNG_EXPORT(229, void, png_set_scale_16, (png_structrp png_ptr)); 1507 #endif 1508 1509 #ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED 1510 #define PNG_READ_16_TO_8 SUPPORTED /* Name prior to 1.5.4 */ 1511 /* Strip the second byte of information from a 16-bit depth file. */ 1512 PNG_EXPORT(48, void, png_set_strip_16, (png_structrp png_ptr)); 1513 #endif 1514 1515 #ifdef PNG_READ_QUANTIZE_SUPPORTED 1516 /* Turn on quantizing, and reduce the palette to the number of colors 1517 * available. 1518 */ 1519 PNG_EXPORT(49, void, png_set_quantize, (png_structrp png_ptr, 1520 png_colorp palette, int num_palette, int maximum_colors, 1521 png_const_uint_16p histogram, int full_quantize)); 1522 #endif 1523 1524 #ifdef PNG_READ_GAMMA_SUPPORTED 1525 /* The threshold on gamma processing is configurable but hard-wired into the 1526 * library. The following is the floating point variant. 1527 */ 1528 #define PNG_GAMMA_THRESHOLD (PNG_GAMMA_THRESHOLD_FIXED*.00001) 1529 1530 /* Handle gamma correction. Screen_gamma=(display_exponent). 1531 * NOTE: this API simply sets the screen and file gamma values. It will 1532 * therefore override the value for gamma in a PNG file if it is called after 1533 * the file header has been read - use with care - call before reading the PNG 1534 * file for best results! 1535 * 1536 * These routines accept the same gamma values as png_set_alpha_mode (described 1537 * above). The PNG_GAMMA_ defines and PNG_DEFAULT_sRGB can be passed to either 1538 * API (floating point or fixed.) Notice, however, that the 'file_gamma' value 1539 * is the inverse of a 'screen gamma' value. 1540 */ 1541 PNG_FP_EXPORT(50, void, png_set_gamma, (png_structrp png_ptr, 1542 double screen_gamma, double override_file_gamma)) 1543 PNG_FIXED_EXPORT(208, void, png_set_gamma_fixed, (png_structrp png_ptr, 1544 png_fixed_point screen_gamma, png_fixed_point override_file_gamma)) 1545 #endif 1546 1547 #ifdef PNG_WRITE_FLUSH_SUPPORTED 1548 /* Set how many lines between output flushes - 0 for no flushing */ 1549 PNG_EXPORT(51, void, png_set_flush, (png_structrp png_ptr, int nrows)); 1550 /* Flush the current PNG output buffer */ 1551 PNG_EXPORT(52, void, png_write_flush, (png_structrp png_ptr)); 1552 #endif 1553 1554 /* Optional update palette with requested transformations */ 1555 PNG_EXPORT(53, void, png_start_read_image, (png_structrp png_ptr)); 1556 1557 /* Optional call to update the users info structure */ 1558 PNG_EXPORT(54, void, png_read_update_info, (png_structrp png_ptr, 1559 png_inforp info_ptr)); 1560 1561 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED 1562 /* Read one or more rows of image data. */ 1563 PNG_EXPORT(55, void, png_read_rows, (png_structrp png_ptr, png_bytepp row, 1564 png_bytepp display_row, png_uint_32 num_rows)); 1565 #endif 1566 1567 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED 1568 /* Read a row of data. */ 1569 PNG_EXPORT(56, void, png_read_row, (png_structrp png_ptr, png_bytep row, 1570 png_bytep display_row)); 1571 #endif 1572 1573 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED 1574 /* Read the whole image into memory at once. */ 1575 PNG_EXPORT(57, void, png_read_image, (png_structrp png_ptr, png_bytepp image)); 1576 #endif 1577 1578 /* Write a row of image data */ 1579 PNG_EXPORT(58, void, png_write_row, (png_structrp png_ptr, 1580 png_const_bytep row)); 1581 1582 /* Write a few rows of image data: (*row) is not written; however, the type 1583 * is declared as writeable to maintain compatibility with previous versions 1584 * of libpng and to allow the 'display_row' array from read_rows to be passed 1585 * unchanged to write_rows. 1586 */ 1587 PNG_EXPORT(59, void, png_write_rows, (png_structrp png_ptr, png_bytepp row, 1588 png_uint_32 num_rows)); 1589 1590 /* Write the image data */ 1591 PNG_EXPORT(60, void, png_write_image, (png_structrp png_ptr, png_bytepp image)); 1592 1593 /* Write the end of the PNG file. */ 1594 PNG_EXPORT(61, void, png_write_end, (png_structrp png_ptr, 1595 png_inforp info_ptr)); 1596 1597 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED 1598 /* Read the end of the PNG file. */ 1599 PNG_EXPORT(62, void, png_read_end, (png_structrp png_ptr, png_inforp info_ptr)); 1600 #endif 1601 1602 /* Free any memory associated with the png_info_struct */ 1603 PNG_EXPORT(63, void, png_destroy_info_struct, (png_const_structrp png_ptr, 1604 png_infopp info_ptr_ptr)); 1605 1606 /* Free any memory associated with the png_struct and the png_info_structs */ 1607 PNG_EXPORT(64, void, png_destroy_read_struct, (png_structpp png_ptr_ptr, 1608 png_infopp info_ptr_ptr, png_infopp end_info_ptr_ptr)); 1609 1610 /* Free any memory associated with the png_struct and the png_info_structs */ 1611 PNG_EXPORT(65, void, png_destroy_write_struct, (png_structpp png_ptr_ptr, 1612 png_infopp info_ptr_ptr)); 1613 1614 /* Set the libpng method of handling chunk CRC errors */ 1615 PNG_EXPORT(66, void, png_set_crc_action, (png_structrp png_ptr, int crit_action, 1616 int ancil_action)); 1617 1618 /* Values for png_set_crc_action() say how to handle CRC errors in 1619 * ancillary and critical chunks, and whether to use the data contained 1620 * therein. Note that it is impossible to "discard" data in a critical 1621 * chunk. For versions prior to 0.90, the action was always error/quit, 1622 * whereas in version 0.90 and later, the action for CRC errors in ancillary 1623 * chunks is warn/discard. These values should NOT be changed. 1624 * 1625 * value action:critical action:ancillary 1626 */ 1627 #define PNG_CRC_DEFAULT 0 /* error/quit warn/discard data */ 1628 #define PNG_CRC_ERROR_QUIT 1 /* error/quit error/quit */ 1629 #define PNG_CRC_WARN_DISCARD 2 /* (INVALID) warn/discard data */ 1630 #define PNG_CRC_WARN_USE 3 /* warn/use data warn/use data */ 1631 #define PNG_CRC_QUIET_USE 4 /* quiet/use data quiet/use data */ 1632 #define PNG_CRC_NO_CHANGE 5 /* use current value use current value */ 1633 1634 /* These functions give the user control over the scan-line filtering in 1635 * libpng and the compression methods used by zlib. These functions are 1636 * mainly useful for testing, as the defaults should work with most users. 1637 * Those users who are tight on memory or want faster performance at the 1638 * expense of compression can modify them. See the compression library 1639 * header file (zlib.h) for an explination of the compression functions. 1640 */ 1641 1642 /* Set the filtering method(s) used by libpng. Currently, the only valid 1643 * value for "method" is 0. 1644 */ 1645 PNG_EXPORT(67, void, png_set_filter, (png_structrp png_ptr, int method, 1646 int filters)); 1647 1648 /* Flags for png_set_filter() to say which filters to use. The flags 1649 * are chosen so that they don't conflict with real filter types 1650 * below, in case they are supplied instead of the #defined constants. 1651 * These values should NOT be changed. 1652 */ 1653 #define PNG_NO_FILTERS 0x00 1654 #define PNG_FILTER_NONE 0x08 1655 #define PNG_FILTER_SUB 0x10 1656 #define PNG_FILTER_UP 0x20 1657 #define PNG_FILTER_AVG 0x40 1658 #define PNG_FILTER_PAETH 0x80 1659 #define PNG_ALL_FILTERS (PNG_FILTER_NONE | PNG_FILTER_SUB | PNG_FILTER_UP | \ 1660 PNG_FILTER_AVG | PNG_FILTER_PAETH) 1661 1662 /* Filter values (not flags) - used in pngwrite.c, pngwutil.c for now. 1663 * These defines should NOT be changed. 1664 */ 1665 #define PNG_FILTER_VALUE_NONE 0 1666 #define PNG_FILTER_VALUE_SUB 1 1667 #define PNG_FILTER_VALUE_UP 2 1668 #define PNG_FILTER_VALUE_AVG 3 1669 #define PNG_FILTER_VALUE_PAETH 4 1670 #define PNG_FILTER_VALUE_LAST 5 1671 1672 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* EXPERIMENTAL */ 1673 /* The "heuristic_method" is given by one of the PNG_FILTER_HEURISTIC_ 1674 * defines, either the default (minimum-sum-of-absolute-differences), or 1675 * the experimental method (weighted-minimum-sum-of-absolute-differences). 1676 * 1677 * Weights are factors >= 1.0, indicating how important it is to keep the 1678 * filter type consistent between rows. Larger numbers mean the current 1679 * filter is that many times as likely to be the same as the "num_weights" 1680 * previous filters. This is cumulative for each previous row with a weight. 1681 * There needs to be "num_weights" values in "filter_weights", or it can be 1682 * NULL if the weights aren't being specified. Weights have no influence on 1683 * the selection of the first row filter. Well chosen weights can (in theory) 1684 * improve the compression for a given image. 1685 * 1686 * Costs are factors >= 1.0 indicating the relative decoding costs of a 1687 * filter type. Higher costs indicate more decoding expense, and are 1688 * therefore less likely to be selected over a filter with lower computational 1689 * costs. There needs to be a value in "filter_costs" for each valid filter 1690 * type (given by PNG_FILTER_VALUE_LAST), or it can be NULL if you aren't 1691 * setting the costs. Costs try to improve the speed of decompression without 1692 * unduly increasing the compressed image size. 1693 * 1694 * A negative weight or cost indicates the default value is to be used, and 1695 * values in the range [0.0, 1.0) indicate the value is to remain unchanged. 1696 * The default values for both weights and costs are currently 1.0, but may 1697 * change if good general weighting/cost heuristics can be found. If both 1698 * the weights and costs are set to 1.0, this degenerates the WEIGHTED method 1699 * to the UNWEIGHTED method, but with added encoding time/computation. 1700 */ 1701 PNG_FP_EXPORT(68, void, png_set_filter_heuristics, (png_structrp png_ptr, 1702 int heuristic_method, int num_weights, png_const_doublep filter_weights, 1703 png_const_doublep filter_costs)) 1704 PNG_FIXED_EXPORT(209, void, png_set_filter_heuristics_fixed, 1705 (png_structrp png_ptr, int heuristic_method, int num_weights, 1706 png_const_fixed_point_p filter_weights, 1707 png_const_fixed_point_p filter_costs)) 1708 #endif /* PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */ 1709 1710 /* Heuristic used for row filter selection. These defines should NOT be 1711 * changed. 1712 */ 1713 #define PNG_FILTER_HEURISTIC_DEFAULT 0 /* Currently "UNWEIGHTED" */ 1714 #define PNG_FILTER_HEURISTIC_UNWEIGHTED 1 /* Used by libpng < 0.95 */ 1715 #define PNG_FILTER_HEURISTIC_WEIGHTED 2 /* Experimental feature */ 1716 #define PNG_FILTER_HEURISTIC_LAST 3 /* Not a valid value */ 1717 1718 #ifdef PNG_WRITE_SUPPORTED 1719 /* Set the library compression level. Currently, valid values range from 1720 * 0 - 9, corresponding directly to the zlib compression levels 0 - 9 1721 * (0 - no compression, 9 - "maximal" compression). Note that tests have 1722 * shown that zlib compression levels 3-6 usually perform as well as level 9 1723 * for PNG images, and do considerably fewer caclulations. In the future, 1724 * these values may not correspond directly to the zlib compression levels. 1725 */ 1726 PNG_EXPORT(69, void, png_set_compression_level, (png_structrp png_ptr, 1727 int level)); 1728 1729 PNG_EXPORT(70, void, png_set_compression_mem_level, (png_structrp png_ptr, 1730 int mem_level)); 1731 1732 PNG_EXPORT(71, void, png_set_compression_strategy, (png_structrp png_ptr, 1733 int strategy)); 1734 1735 /* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a 1736 * smaller value of window_bits if it can do so safely. 1737 */ 1738 PNG_EXPORT(72, void, png_set_compression_window_bits, (png_structrp png_ptr, 1739 int window_bits)); 1740 1741 PNG_EXPORT(73, void, png_set_compression_method, (png_structrp png_ptr, 1742 int method)); 1743 #endif 1744 1745 #ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED 1746 /* Also set zlib parameters for compressing non-IDAT chunks */ 1747 PNG_EXPORT(222, void, png_set_text_compression_level, (png_structrp png_ptr, 1748 int level)); 1749 1750 PNG_EXPORT(223, void, png_set_text_compression_mem_level, (png_structrp png_ptr, 1751 int mem_level)); 1752 1753 PNG_EXPORT(224, void, png_set_text_compression_strategy, (png_structrp png_ptr, 1754 int strategy)); 1755 1756 /* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a 1757 * smaller value of window_bits if it can do so safely. 1758 */ 1759 PNG_EXPORT(225, void, png_set_text_compression_window_bits, 1760 (png_structrp png_ptr, int window_bits)); 1761 1762 PNG_EXPORT(226, void, png_set_text_compression_method, (png_structrp png_ptr, 1763 int method)); 1764 #endif /* PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED */ 1765 1766 /* These next functions are called for input/output, memory, and error 1767 * handling. They are in the file pngrio.c, pngwio.c, and pngerror.c, 1768 * and call standard C I/O routines such as fread(), fwrite(), and 1769 * fprintf(). These functions can be made to use other I/O routines 1770 * at run time for those applications that need to handle I/O in a 1771 * different manner by calling png_set_???_fn(). See libpng-manual.txt for 1772 * more information. 1773 */ 1774 1775 #ifdef PNG_STDIO_SUPPORTED 1776 /* Initialize the input/output for the PNG file to the default functions. */ 1777 PNG_EXPORT(74, void, png_init_io, (png_structrp png_ptr, png_FILE_p fp)); 1778 #endif 1779 1780 /* Replace the (error and abort), and warning functions with user 1781 * supplied functions. If no messages are to be printed you must still 1782 * write and use replacement functions. The replacement error_fn should 1783 * still do a longjmp to the last setjmp location if you are using this 1784 * method of error handling. If error_fn or warning_fn is NULL, the 1785 * default function will be used. 1786 */ 1787 1788 PNG_EXPORT(75, void, png_set_error_fn, (png_structrp png_ptr, 1789 png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warning_fn)); 1790 1791 /* Return the user pointer associated with the error functions */ 1792 PNG_EXPORT(76, png_voidp, png_get_error_ptr, (png_const_structrp png_ptr)); 1793 1794 /* Replace the default data output functions with a user supplied one(s). 1795 * If buffered output is not used, then output_flush_fn can be set to NULL. 1796 * If PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile time 1797 * output_flush_fn will be ignored (and thus can be NULL). 1798 * It is probably a mistake to use NULL for output_flush_fn if 1799 * write_data_fn is not also NULL unless you have built libpng with 1800 * PNG_WRITE_FLUSH_SUPPORTED undefined, because in this case libpng's 1801 * default flush function, which uses the standard *FILE structure, will 1802 * be used. 1803 */ 1804 PNG_EXPORT(77, void, png_set_write_fn, (png_structrp png_ptr, png_voidp io_ptr, 1805 png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn)); 1806 1807 /* Replace the default data input function with a user supplied one. */ 1808 PNG_EXPORT(78, void, png_set_read_fn, (png_structrp png_ptr, png_voidp io_ptr, 1809 png_rw_ptr read_data_fn)); 1810 1811 /* Return the user pointer associated with the I/O functions */ 1812 PNG_EXPORT(79, png_voidp, png_get_io_ptr, (png_const_structrp png_ptr)); 1813 1814 PNG_EXPORT(80, void, png_set_read_status_fn, (png_structrp png_ptr, 1815 png_read_status_ptr read_row_fn)); 1816 1817 PNG_EXPORT(81, void, png_set_write_status_fn, (png_structrp png_ptr, 1818 png_write_status_ptr write_row_fn)); 1819 1820 #ifdef PNG_USER_MEM_SUPPORTED 1821 /* Replace the default memory allocation functions with user supplied one(s). */ 1822 PNG_EXPORT(82, void, png_set_mem_fn, (png_structrp png_ptr, png_voidp mem_ptr, 1823 png_malloc_ptr malloc_fn, png_free_ptr free_fn)); 1824 /* Return the user pointer associated with the memory functions */ 1825 PNG_EXPORT(83, png_voidp, png_get_mem_ptr, (png_const_structrp png_ptr)); 1826 #endif 1827 1828 #ifdef PNG_READ_USER_TRANSFORM_SUPPORTED 1829 PNG_EXPORT(84, void, png_set_read_user_transform_fn, (png_structrp png_ptr, 1830 png_user_transform_ptr read_user_transform_fn)); 1831 #endif 1832 1833 #ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED 1834 PNG_EXPORT(85, void, png_set_write_user_transform_fn, (png_structrp png_ptr, 1835 png_user_transform_ptr write_user_transform_fn)); 1836 #endif 1837 1838 #ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED 1839 PNG_EXPORT(86, void, png_set_user_transform_info, (png_structrp png_ptr, 1840 png_voidp user_transform_ptr, int user_transform_depth, 1841 int user_transform_channels)); 1842 /* Return the user pointer associated with the user transform functions */ 1843 PNG_EXPORT(87, png_voidp, png_get_user_transform_ptr, 1844 (png_const_structrp png_ptr)); 1845 #endif 1846 1847 #ifdef PNG_USER_TRANSFORM_INFO_SUPPORTED 1848 /* Return information about the row currently being processed. Note that these 1849 * APIs do not fail but will return unexpected results if called outside a user 1850 * transform callback. Also note that when transforming an interlaced image the 1851 * row number is the row number within the sub-image of the interlace pass, so 1852 * the value will increase to the height of the sub-image (not the full image) 1853 * then reset to 0 for the next pass. 1854 * 1855 * Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to 1856 * find the output pixel (x,y) given an interlaced sub-image pixel 1857 * (row,col,pass). (See below for these macros.) 1858 */ 1859 PNG_EXPORT(217, png_uint_32, png_get_current_row_number, (png_const_structrp)); 1860 PNG_EXPORT(218, png_byte, png_get_current_pass_number, (png_const_structrp)); 1861 #endif 1862 1863 #ifdef PNG_READ_USER_CHUNKS_SUPPORTED 1864 /* This callback is called only for *unknown* chunks. If 1865 * PNG_HANDLE_AS_UNKNOWN_SUPPORTED is set then it is possible to set known 1866 * chunks to be treated as unknown, however in this case the callback must do 1867 * any processing required by the chunk (e.g. by calling the appropriate 1868 * png_set_ APIs.) 1869 * 1870 * There is no write support - on write, by default, all the chunks in the 1871 * 'unknown' list are written in the specified position. 1872 * 1873 * The integer return from the callback function is interpreted thus: 1874 * 1875 * negative: An error occured, png_chunk_error will be called. 1876 * zero: The chunk was not handled, the chunk will be saved. A critical 1877 * chunk will cause an error at this point unless it is to be saved. 1878 * positive: The chunk was handled, libpng will ignore/discard it. 1879 * 1880 * See "INTERACTION WTIH USER CHUNK CALLBACKS" below for important notes about 1881 * how this behavior will change in libpng 1.7 1882 */ 1883 PNG_EXPORT(88, void, png_set_read_user_chunk_fn, (png_structrp png_ptr, 1884 png_voidp user_chunk_ptr, png_user_chunk_ptr read_user_chunk_fn)); 1885 #endif 1886 1887 #ifdef PNG_USER_CHUNKS_SUPPORTED 1888 PNG_EXPORT(89, png_voidp, png_get_user_chunk_ptr, (png_const_structrp png_ptr)); 1889 #endif 1890 1891 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED 1892 /* Sets the function callbacks for the push reader, and a pointer to a 1893 * user-defined structure available to the callback functions. 1894 */ 1895 PNG_EXPORT(90, void, png_set_progressive_read_fn, (png_structrp png_ptr, 1896 png_voidp progressive_ptr, png_progressive_info_ptr info_fn, 1897 png_progressive_row_ptr row_fn, png_progressive_end_ptr end_fn)); 1898 1899 /* Returns the user pointer associated with the push read functions */ 1900 PNG_EXPORT(91, png_voidp, png_get_progressive_ptr, 1901 (png_const_structrp png_ptr)); 1902 1903 /* Function to be called when data becomes available */ 1904 PNG_EXPORT(92, void, png_process_data, (png_structrp png_ptr, 1905 png_inforp info_ptr, png_bytep buffer, png_size_t buffer_size)); 1906 1907 /* A function which may be called *only* within png_process_data to stop the 1908 * processing of any more data. The function returns the number of bytes 1909 * remaining, excluding any that libpng has cached internally. A subsequent 1910 * call to png_process_data must supply these bytes again. If the argument 1911 * 'save' is set to true the routine will first save all the pending data and 1912 * will always return 0. 1913 */ 1914 PNG_EXPORT(219, png_size_t, png_process_data_pause, (png_structrp, int save)); 1915 1916 /* A function which may be called *only* outside (after) a call to 1917 * png_process_data. It returns the number of bytes of data to skip in the 1918 * input. Normally it will return 0, but if it returns a non-zero value the 1919 * application must skip than number of bytes of input data and pass the 1920 * following data to the next call to png_process_data. 1921 */ 1922 PNG_EXPORT(220, png_uint_32, png_process_data_skip, (png_structrp)); 1923 1924 #ifdef PNG_READ_INTERLACING_SUPPORTED 1925 /* Function that combines rows. 'new_row' is a flag that should come from 1926 * the callback and be non-NULL if anything needs to be done; the library 1927 * stores its own version of the new data internally and ignores the passed 1928 * in value. 1929 */ 1930 PNG_EXPORT(93, void, png_progressive_combine_row, (png_const_structrp png_ptr, 1931 png_bytep old_row, png_const_bytep new_row)); 1932 #endif /* PNG_READ_INTERLACING_SUPPORTED */ 1933 #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */ 1934 1935 PNG_EXPORTA(94, png_voidp, png_malloc, (png_const_structrp png_ptr, 1936 png_alloc_size_t size), PNG_ALLOCATED); 1937 /* Added at libpng version 1.4.0 */ 1938 PNG_EXPORTA(95, png_voidp, png_calloc, (png_const_structrp png_ptr, 1939 png_alloc_size_t size), PNG_ALLOCATED); 1940 1941 /* Added at libpng version 1.2.4 */ 1942 PNG_EXPORTA(96, png_voidp, png_malloc_warn, (png_const_structrp png_ptr, 1943 png_alloc_size_t size), PNG_ALLOCATED); 1944 1945 /* Frees a pointer allocated by png_malloc() */ 1946 PNG_EXPORT(97, void, png_free, (png_const_structrp png_ptr, png_voidp ptr)); 1947 1948 /* Free data that was allocated internally */ 1949 PNG_EXPORT(98, void, png_free_data, (png_const_structrp png_ptr, 1950 png_inforp info_ptr, png_uint_32 free_me, int num)); 1951 1952 /* Reassign responsibility for freeing existing data, whether allocated 1953 * by libpng or by the application; this works on the png_info structure passed 1954 * in, it does not change the state for other png_info structures. 1955 * 1956 * It is unlikely that this function works correctly as of 1.6.0 and using it 1957 * may result either in memory leaks or double free of allocated data. 1958 */ 1959 PNG_EXPORTA(99, void, png_data_freer, (png_const_structrp png_ptr, 1960 png_inforp info_ptr, int freer, png_uint_32 mask), PNG_DEPRECATED); 1961 1962 /* Assignments for png_data_freer */ 1963 #define PNG_DESTROY_WILL_FREE_DATA 1 1964 #define PNG_SET_WILL_FREE_DATA 1 1965 #define PNG_USER_WILL_FREE_DATA 2 1966 /* Flags for png_ptr->free_me and info_ptr->free_me */ 1967 #define PNG_FREE_HIST 0x0008 1968 #define PNG_FREE_ICCP 0x0010 1969 #define PNG_FREE_SPLT 0x0020 1970 #define PNG_FREE_ROWS 0x0040 1971 #define PNG_FREE_PCAL 0x0080 1972 #define PNG_FREE_SCAL 0x0100 1973 #ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED 1974 # define PNG_FREE_UNKN 0x0200 1975 #endif 1976 /* PNG_FREE_LIST 0x0400 removed in 1.6.0 because it is ignored */ 1977 #define PNG_FREE_PLTE 0x1000 1978 #define PNG_FREE_TRNS 0x2000 1979 #define PNG_FREE_TEXT 0x4000 1980 #define PNG_FREE_ALL 0x7fff 1981 #define PNG_FREE_MUL 0x4220 /* PNG_FREE_SPLT|PNG_FREE_TEXT|PNG_FREE_UNKN */ 1982 1983 #ifdef PNG_USER_MEM_SUPPORTED 1984 PNG_EXPORTA(100, png_voidp, png_malloc_default, (png_const_structrp png_ptr, 1985 png_alloc_size_t size), PNG_ALLOCATED PNG_DEPRECATED); 1986 PNG_EXPORTA(101, void, png_free_default, (png_const_structrp png_ptr, 1987 png_voidp ptr), PNG_DEPRECATED); 1988 #endif 1989 1990 #ifdef PNG_ERROR_TEXT_SUPPORTED 1991 /* Fatal error in PNG image of libpng - can't continue */ 1992 PNG_EXPORTA(102, void, png_error, (png_const_structrp png_ptr, 1993 png_const_charp error_message), PNG_NORETURN); 1994 1995 /* The same, but the chunk name is prepended to the error string. */ 1996 PNG_EXPORTA(103, void, png_chunk_error, (png_const_structrp png_ptr, 1997 png_const_charp error_message), PNG_NORETURN); 1998 1999 #else 2000 /* Fatal error in PNG image of libpng - can't continue */ 2001 PNG_EXPORTA(104, void, png_err, (png_const_structrp png_ptr), PNG_NORETURN); 2002 #endif 2003 2004 #ifdef PNG_WARNINGS_SUPPORTED 2005 /* Non-fatal error in libpng. Can continue, but may have a problem. */ 2006 PNG_EXPORT(105, void, png_warning, (png_const_structrp png_ptr, 2007 png_const_charp warning_message)); 2008 2009 /* Non-fatal error in libpng, chunk name is prepended to message. */ 2010 PNG_EXPORT(106, void, png_chunk_warning, (png_const_structrp png_ptr, 2011 png_const_charp warning_message)); 2012 #endif 2013 2014 #ifdef PNG_BENIGN_ERRORS_SUPPORTED 2015 /* Benign error in libpng. Can continue, but may have a problem. 2016 * User can choose whether to handle as a fatal error or as a warning. */ 2017 PNG_EXPORT(107, void, png_benign_error, (png_const_structrp png_ptr, 2018 png_const_charp warning_message)); 2019 2020 #ifdef PNG_READ_SUPPORTED 2021 /* Same, chunk name is prepended to message (only during read) */ 2022 PNG_EXPORT(108, void, png_chunk_benign_error, (png_const_structrp png_ptr, 2023 png_const_charp warning_message)); 2024 #endif 2025 2026 PNG_EXPORT(109, void, png_set_benign_errors, 2027 (png_structrp png_ptr, int allowed)); 2028 #else 2029 # ifdef PNG_ALLOW_BENIGN_ERRORS 2030 # define png_benign_error png_warning 2031 # define png_chunk_benign_error png_chunk_warning 2032 # else 2033 # define png_benign_error png_error 2034 # define png_chunk_benign_error png_chunk_error 2035 # endif 2036 #endif 2037 2038 /* The png_set_<chunk> functions are for storing values in the png_info_struct. 2039 * Similarly, the png_get_<chunk> calls are used to read values from the 2040 * png_info_struct, either storing the parameters in the passed variables, or 2041 * setting pointers into the png_info_struct where the data is stored. The 2042 * png_get_<chunk> functions return a non-zero value if the data was available 2043 * in info_ptr, or return zero and do not change any of the parameters if the 2044 * data was not available. 2045 * 2046 * These functions should be used instead of directly accessing png_info 2047 * to avoid problems with future changes in the size and internal layout of 2048 * png_info_struct. 2049 */ 2050 /* Returns "flag" if chunk data is valid in info_ptr. */ 2051 PNG_EXPORT(110, png_uint_32, png_get_valid, (png_const_structrp png_ptr, 2052 png_const_inforp info_ptr, png_uint_32 flag)); 2053 2054 /* Returns number of bytes needed to hold a transformed row. */ 2055 PNG_EXPORT(111, png_size_t, png_get_rowbytes, (png_const_structrp png_ptr, 2056 png_const_inforp info_ptr)); 2057 2058 #ifdef PNG_INFO_IMAGE_SUPPORTED 2059 /* Returns row_pointers, which is an array of pointers to scanlines that was 2060 * returned from png_read_png(). 2061 */ 2062 PNG_EXPORT(112, png_bytepp, png_get_rows, (png_const_structrp png_ptr, 2063 png_const_inforp info_ptr)); 2064 2065 /* Set row_pointers, which is an array of pointers to scanlines for use 2066 * by png_write_png(). 2067 */ 2068 PNG_EXPORT(113, void, png_set_rows, (png_const_structrp png_ptr, 2069 png_inforp info_ptr, png_bytepp row_pointers)); 2070 #endif 2071 2072 /* Returns number of color channels in image. */ 2073 PNG_EXPORT(114, png_byte, png_get_channels, (png_const_structrp png_ptr, 2074 png_const_inforp info_ptr)); 2075 2076 #ifdef PNG_EASY_ACCESS_SUPPORTED 2077 /* Returns image width in pixels. */ 2078 PNG_EXPORT(115, png_uint_32, png_get_image_width, (png_const_structrp png_ptr, 2079 png_const_inforp info_ptr)); 2080 2081 /* Returns image height in pixels. */ 2082 PNG_EXPORT(116, png_uint_32, png_get_image_height, (png_const_structrp png_ptr, 2083 png_const_inforp info_ptr)); 2084 2085 /* Returns image bit_depth. */ 2086 PNG_EXPORT(117, png_byte, png_get_bit_depth, (png_const_structrp png_ptr, 2087 png_const_inforp info_ptr)); 2088 2089 /* Returns image color_type. */ 2090 PNG_EXPORT(118, png_byte, png_get_color_type, (png_const_structrp png_ptr, 2091 png_const_inforp info_ptr)); 2092 2093 /* Returns image filter_type. */ 2094 PNG_EXPORT(119, png_byte, png_get_filter_type, (png_const_structrp png_ptr, 2095 png_const_inforp info_ptr)); 2096 2097 /* Returns image interlace_type. */ 2098 PNG_EXPORT(120, png_byte, png_get_interlace_type, (png_const_structrp png_ptr, 2099 png_const_inforp info_ptr)); 2100 2101 /* Returns image compression_type. */ 2102 PNG_EXPORT(121, png_byte, png_get_compression_type, (png_const_structrp png_ptr, 2103 png_const_inforp info_ptr)); 2104 2105 /* Returns image resolution in pixels per meter, from pHYs chunk data. */ 2106 PNG_EXPORT(122, png_uint_32, png_get_pixels_per_meter, 2107 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 2108 PNG_EXPORT(123, png_uint_32, png_get_x_pixels_per_meter, 2109 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 2110 PNG_EXPORT(124, png_uint_32, png_get_y_pixels_per_meter, 2111 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 2112 2113 /* Returns pixel aspect ratio, computed from pHYs chunk data. */ 2114 PNG_FP_EXPORT(125, float, png_get_pixel_aspect_ratio, 2115 (png_const_structrp png_ptr, png_const_inforp info_ptr)) 2116 PNG_FIXED_EXPORT(210, png_fixed_point, png_get_pixel_aspect_ratio_fixed, 2117 (png_const_structrp png_ptr, png_const_inforp info_ptr)) 2118 2119 /* Returns image x, y offset in pixels or microns, from oFFs chunk data. */ 2120 PNG_EXPORT(126, png_int_32, png_get_x_offset_pixels, 2121 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 2122 PNG_EXPORT(127, png_int_32, png_get_y_offset_pixels, 2123 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 2124 PNG_EXPORT(128, png_int_32, png_get_x_offset_microns, 2125 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 2126 PNG_EXPORT(129, png_int_32, png_get_y_offset_microns, 2127 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 2128 2129 #endif /* PNG_EASY_ACCESS_SUPPORTED */ 2130 2131 #ifdef PNG_READ_SUPPORTED 2132 /* Returns pointer to signature string read from PNG header */ 2133 PNG_EXPORT(130, png_const_bytep, png_get_signature, (png_const_structrp png_ptr, 2134 png_const_inforp info_ptr)); 2135 #endif 2136 2137 #ifdef PNG_bKGD_SUPPORTED 2138 PNG_EXPORT(131, png_uint_32, png_get_bKGD, (png_const_structrp png_ptr, 2139 png_inforp info_ptr, png_color_16p *background)); 2140 #endif 2141 2142 #ifdef PNG_bKGD_SUPPORTED 2143 PNG_EXPORT(132, void, png_set_bKGD, (png_const_structrp png_ptr, 2144 png_inforp info_ptr, png_const_color_16p background)); 2145 #endif 2146 2147 #ifdef PNG_cHRM_SUPPORTED 2148 PNG_FP_EXPORT(133, png_uint_32, png_get_cHRM, (png_const_structrp png_ptr, 2149 png_const_inforp info_ptr, double *white_x, double *white_y, double *red_x, 2150 double *red_y, double *green_x, double *green_y, double *blue_x, 2151 double *blue_y)) 2152 PNG_FP_EXPORT(230, png_uint_32, png_get_cHRM_XYZ, (png_const_structrp png_ptr, 2153 png_const_inforp info_ptr, double *red_X, double *red_Y, double *red_Z, 2154 double *green_X, double *green_Y, double *green_Z, double *blue_X, 2155 double *blue_Y, double *blue_Z)) 2156 PNG_FIXED_EXPORT(134, png_uint_32, png_get_cHRM_fixed, 2157 (png_const_structrp png_ptr, png_const_inforp info_ptr, 2158 png_fixed_point *int_white_x, png_fixed_point *int_white_y, 2159 png_fixed_point *int_red_x, png_fixed_point *int_red_y, 2160 png_fixed_point *int_green_x, png_fixed_point *int_green_y, 2161 png_fixed_point *int_blue_x, png_fixed_point *int_blue_y)) 2162 PNG_FIXED_EXPORT(231, png_uint_32, png_get_cHRM_XYZ_fixed, 2163 (png_const_structrp png_ptr, png_const_inforp info_ptr, 2164 png_fixed_point *int_red_X, png_fixed_point *int_red_Y, 2165 png_fixed_point *int_red_Z, png_fixed_point *int_green_X, 2166 png_fixed_point *int_green_Y, png_fixed_point *int_green_Z, 2167 png_fixed_point *int_blue_X, png_fixed_point *int_blue_Y, 2168 png_fixed_point *int_blue_Z)) 2169 #endif 2170 2171 #ifdef PNG_cHRM_SUPPORTED 2172 PNG_FP_EXPORT(135, void, png_set_cHRM, (png_const_structrp png_ptr, 2173 png_inforp info_ptr, 2174 double white_x, double white_y, double red_x, double red_y, double green_x, 2175 double green_y, double blue_x, double blue_y)) 2176 PNG_FP_EXPORT(232, void, png_set_cHRM_XYZ, (png_const_structrp png_ptr, 2177 png_inforp info_ptr, double red_X, double red_Y, double red_Z, 2178 double green_X, double green_Y, double green_Z, double blue_X, 2179 double blue_Y, double blue_Z)) 2180 PNG_FIXED_EXPORT(136, void, png_set_cHRM_fixed, (png_const_structrp png_ptr, 2181 png_inforp info_ptr, png_fixed_point int_white_x, 2182 png_fixed_point int_white_y, png_fixed_point int_red_x, 2183 png_fixed_point int_red_y, png_fixed_point int_green_x, 2184 png_fixed_point int_green_y, png_fixed_point int_blue_x, 2185 png_fixed_point int_blue_y)) 2186 PNG_FIXED_EXPORT(233, void, png_set_cHRM_XYZ_fixed, (png_const_structrp png_ptr, 2187 png_inforp info_ptr, png_fixed_point int_red_X, png_fixed_point int_red_Y, 2188 png_fixed_point int_red_Z, png_fixed_point int_green_X, 2189 png_fixed_point int_green_Y, png_fixed_point int_green_Z, 2190 png_fixed_point int_blue_X, png_fixed_point int_blue_Y, 2191 png_fixed_point int_blue_Z)) 2192 #endif 2193 2194 #ifdef PNG_gAMA_SUPPORTED 2195 PNG_FP_EXPORT(137, png_uint_32, png_get_gAMA, (png_const_structrp png_ptr, 2196 png_const_inforp info_ptr, double *file_gamma)) 2197 PNG_FIXED_EXPORT(138, png_uint_32, png_get_gAMA_fixed, 2198 (png_const_structrp png_ptr, png_const_inforp info_ptr, 2199 png_fixed_point *int_file_gamma)) 2200 #endif 2201 2202 #ifdef PNG_gAMA_SUPPORTED 2203 PNG_FP_EXPORT(139, void, png_set_gAMA, (png_const_structrp png_ptr, 2204 png_inforp info_ptr, double file_gamma)) 2205 PNG_FIXED_EXPORT(140, void, png_set_gAMA_fixed, (png_const_structrp png_ptr, 2206 png_inforp info_ptr, png_fixed_point int_file_gamma)) 2207 #endif 2208 2209 #ifdef PNG_hIST_SUPPORTED 2210 PNG_EXPORT(141, png_uint_32, png_get_hIST, (png_const_structrp png_ptr, 2211 png_inforp info_ptr, png_uint_16p *hist)); 2212 #endif 2213 2214 #ifdef PNG_hIST_SUPPORTED 2215 PNG_EXPORT(142, void, png_set_hIST, (png_const_structrp png_ptr, 2216 png_inforp info_ptr, png_const_uint_16p hist)); 2217 #endif 2218 2219 PNG_EXPORT(143, png_uint_32, png_get_IHDR, (png_const_structrp png_ptr, 2220 png_const_inforp info_ptr, png_uint_32 *width, png_uint_32 *height, 2221 int *bit_depth, int *color_type, int *interlace_method, 2222 int *compression_method, int *filter_method)); 2223 2224 PNG_EXPORT(144, void, png_set_IHDR, (png_const_structrp png_ptr, 2225 png_inforp info_ptr, png_uint_32 width, png_uint_32 height, int bit_depth, 2226 int color_type, int interlace_method, int compression_method, 2227 int filter_method)); 2228 2229 #ifdef PNG_oFFs_SUPPORTED 2230 PNG_EXPORT(145, png_uint_32, png_get_oFFs, (png_const_structrp png_ptr, 2231 png_const_inforp info_ptr, png_int_32 *offset_x, png_int_32 *offset_y, 2232 int *unit_type)); 2233 #endif 2234 2235 #ifdef PNG_oFFs_SUPPORTED 2236 PNG_EXPORT(146, void, png_set_oFFs, (png_const_structrp png_ptr, 2237 png_inforp info_ptr, png_int_32 offset_x, png_int_32 offset_y, 2238 int unit_type)); 2239 #endif 2240 2241 #ifdef PNG_pCAL_SUPPORTED 2242 PNG_EXPORT(147, png_uint_32, png_get_pCAL, (png_const_structrp png_ptr, 2243 png_inforp info_ptr, png_charp *purpose, png_int_32 *X0, 2244 png_int_32 *X1, int *type, int *nparams, png_charp *units, 2245 png_charpp *params)); 2246 #endif 2247 2248 #ifdef PNG_pCAL_SUPPORTED 2249 PNG_EXPORT(148, void, png_set_pCAL, (png_const_structrp png_ptr, 2250 png_inforp info_ptr, png_const_charp purpose, png_int_32 X0, png_int_32 X1, 2251 int type, int nparams, png_const_charp units, png_charpp params)); 2252 #endif 2253 2254 #ifdef PNG_pHYs_SUPPORTED 2255 PNG_EXPORT(149, png_uint_32, png_get_pHYs, (png_const_structrp png_ptr, 2256 png_const_inforp info_ptr, png_uint_32 *res_x, png_uint_32 *res_y, 2257 int *unit_type)); 2258 #endif 2259 2260 #ifdef PNG_pHYs_SUPPORTED 2261 PNG_EXPORT(150, void, png_set_pHYs, (png_const_structrp png_ptr, 2262 png_inforp info_ptr, png_uint_32 res_x, png_uint_32 res_y, int unit_type)); 2263 #endif 2264 2265 PNG_EXPORT(151, png_uint_32, png_get_PLTE, (png_const_structrp png_ptr, 2266 png_inforp info_ptr, png_colorp *palette, int *num_palette)); 2267 2268 PNG_EXPORT(152, void, png_set_PLTE, (png_structrp png_ptr, 2269 png_inforp info_ptr, png_const_colorp palette, int num_palette)); 2270 2271 #ifdef PNG_sBIT_SUPPORTED 2272 PNG_EXPORT(153, png_uint_32, png_get_sBIT, (png_const_structrp png_ptr, 2273 png_inforp info_ptr, png_color_8p *sig_bit)); 2274 #endif 2275 2276 #ifdef PNG_sBIT_SUPPORTED 2277 PNG_EXPORT(154, void, png_set_sBIT, (png_const_structrp png_ptr, 2278 png_inforp info_ptr, png_const_color_8p sig_bit)); 2279 #endif 2280 2281 #ifdef PNG_sRGB_SUPPORTED 2282 PNG_EXPORT(155, png_uint_32, png_get_sRGB, (png_const_structrp png_ptr, 2283 png_const_inforp info_ptr, int *file_srgb_intent)); 2284 #endif 2285 2286 #ifdef PNG_sRGB_SUPPORTED 2287 PNG_EXPORT(156, void, png_set_sRGB, (png_const_structrp png_ptr, 2288 png_inforp info_ptr, int srgb_intent)); 2289 PNG_EXPORT(157, void, png_set_sRGB_gAMA_and_cHRM, (png_const_structrp png_ptr, 2290 png_inforp info_ptr, int srgb_intent)); 2291 #endif 2292 2293 #ifdef PNG_iCCP_SUPPORTED 2294 PNG_EXPORT(158, png_uint_32, png_get_iCCP, (png_const_structrp png_ptr, 2295 png_inforp info_ptr, png_charpp name, int *compression_type, 2296 png_bytepp profile, png_uint_32 *proflen)); 2297 #endif 2298 2299 #ifdef PNG_iCCP_SUPPORTED 2300 PNG_EXPORT(159, void, png_set_iCCP, (png_const_structrp png_ptr, 2301 png_inforp info_ptr, png_const_charp name, int compression_type, 2302 png_const_bytep profile, png_uint_32 proflen)); 2303 #endif 2304 2305 #ifdef PNG_sPLT_SUPPORTED 2306 PNG_EXPORT(160, int, png_get_sPLT, (png_const_structrp png_ptr, 2307 png_inforp info_ptr, png_sPLT_tpp entries)); 2308 #endif 2309 2310 #ifdef PNG_sPLT_SUPPORTED 2311 PNG_EXPORT(161, void, png_set_sPLT, (png_const_structrp png_ptr, 2312 png_inforp info_ptr, png_const_sPLT_tp entries, int nentries)); 2313 #endif 2314 2315 #ifdef PNG_TEXT_SUPPORTED 2316 /* png_get_text also returns the number of text chunks in *num_text */ 2317 PNG_EXPORT(162, int, png_get_text, (png_const_structrp png_ptr, 2318 png_inforp info_ptr, png_textp *text_ptr, int *num_text)); 2319 #endif 2320 2321 /* Note while png_set_text() will accept a structure whose text, 2322 * language, and translated keywords are NULL pointers, the structure 2323 * returned by png_get_text will always contain regular 2324 * zero-terminated C strings. They might be empty strings but 2325 * they will never be NULL pointers. 2326 */ 2327 2328 #ifdef PNG_TEXT_SUPPORTED 2329 PNG_EXPORT(163, void, png_set_text, (png_const_structrp png_ptr, 2330 png_inforp info_ptr, png_const_textp text_ptr, int num_text)); 2331 #endif 2332 2333 #ifdef PNG_tIME_SUPPORTED 2334 PNG_EXPORT(164, png_uint_32, png_get_tIME, (png_const_structrp png_ptr, 2335 png_inforp info_ptr, png_timep *mod_time)); 2336 #endif 2337 2338 #ifdef PNG_tIME_SUPPORTED 2339 PNG_EXPORT(165, void, png_set_tIME, (png_const_structrp png_ptr, 2340 png_inforp info_ptr, png_const_timep mod_time)); 2341 #endif 2342 2343 #ifdef PNG_tRNS_SUPPORTED 2344 PNG_EXPORT(166, png_uint_32, png_get_tRNS, (png_const_structrp png_ptr, 2345 png_inforp info_ptr, png_bytep *trans_alpha, int *num_trans, 2346 png_color_16p *trans_color)); 2347 #endif 2348 2349 #ifdef PNG_tRNS_SUPPORTED 2350 PNG_EXPORT(167, void, png_set_tRNS, (png_structrp png_ptr, 2351 png_inforp info_ptr, png_const_bytep trans_alpha, int num_trans, 2352 png_const_color_16p trans_color)); 2353 #endif 2354 2355 #ifdef PNG_sCAL_SUPPORTED 2356 PNG_FP_EXPORT(168, png_uint_32, png_get_sCAL, (png_const_structrp png_ptr, 2357 png_const_inforp info_ptr, int *unit, double *width, double *height)) 2358 #if defined(PNG_FLOATING_ARITHMETIC_SUPPORTED) || \ 2359 defined(PNG_FLOATING_POINT_SUPPORTED) 2360 /* NOTE: this API is currently implemented using floating point arithmetic, 2361 * consequently it can only be used on systems with floating point support. 2362 * In any case the range of values supported by png_fixed_point is small and it 2363 * is highly recommended that png_get_sCAL_s be used instead. 2364 */ 2365 PNG_FIXED_EXPORT(214, png_uint_32, png_get_sCAL_fixed, 2366 (png_const_structrp png_ptr, png_const_inforp info_ptr, int *unit, 2367 png_fixed_point *width, png_fixed_point *height)) 2368 #endif 2369 PNG_EXPORT(169, png_uint_32, png_get_sCAL_s, 2370 (png_const_structrp png_ptr, png_const_inforp info_ptr, int *unit, 2371 png_charpp swidth, png_charpp sheight)); 2372 2373 PNG_FP_EXPORT(170, void, png_set_sCAL, (png_const_structrp png_ptr, 2374 png_inforp info_ptr, int unit, double width, double height)) 2375 PNG_FIXED_EXPORT(213, void, png_set_sCAL_fixed, (png_const_structrp png_ptr, 2376 png_inforp info_ptr, int unit, png_fixed_point width, 2377 png_fixed_point height)) 2378 PNG_EXPORT(171, void, png_set_sCAL_s, (png_const_structrp png_ptr, 2379 png_inforp info_ptr, int unit, 2380 png_const_charp swidth, png_const_charp sheight)); 2381 #endif /* PNG_sCAL_SUPPORTED */ 2382 2383 #ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED 2384 /* Provide the default handling for all unknown chunks or, optionally, for 2385 * specific unknown chunks. 2386 * 2387 * NOTE: prior to 1.6.0 the handling specified for particular chunks on read was 2388 * ignored and the default was used, the per-chunk setting only had an effect on 2389 * write. If you wish to have chunk-specific handling on read in code that must 2390 * work on earlier versions you must use a user chunk callback to specify the 2391 * desired handling (keep or discard.) 2392 * 2393 * The 'keep' parameter is a PNG_HANDLE_CHUNK_ value as listed below. The 2394 * parameter is interpreted as follows: 2395 * 2396 * READ: 2397 * PNG_HANDLE_CHUNK_AS_DEFAULT: 2398 * Known chunks: do normal libpng processing, do not keep the chunk (but 2399 * see the comments below about PNG_HANDLE_AS_UNKNOWN_SUPPORTED) 2400 * Unknown chunks: for a specific chunk use the global default, when used 2401 * as the default discard the chunk data. 2402 * PNG_HANDLE_CHUNK_NEVER: 2403 * Discard the chunk data. 2404 * PNG_HANDLE_CHUNK_IF_SAFE: 2405 * Keep the chunk data if the chunk is not critical else raise a chunk 2406 * error. 2407 * PNG_HANDLE_CHUNK_ALWAYS: 2408 * Keep the chunk data. 2409 * 2410 * If the chunk data is saved it can be retrieved using png_get_unknown_chunks, 2411 * below. Notice that specifying "AS_DEFAULT" as a global default is equivalent 2412 * to specifying "NEVER", however when "AS_DEFAULT" is used for specific chunks 2413 * it simply resets the behavior to the libpng default. 2414 * 2415 * INTERACTION WTIH USER CHUNK CALLBACKS: 2416 * The per-chunk handling is always used when there is a png_user_chunk_ptr 2417 * callback and the callback returns 0; the chunk is then always stored *unless* 2418 * it is critical and the per-chunk setting is other than ALWAYS. Notice that 2419 * the global default is *not* used in this case. (In effect the per-chunk 2420 * value is incremented to at least IF_SAFE.) 2421 * 2422 * IMPORTANT NOTE: this behavior will change in libpng 1.7 - the global and 2423 * per-chunk defaults will be honored. If you want to preserve the current 2424 * behavior when your callback returns 0 you must set PNG_HANDLE_CHUNK_IF_SAFE 2425 * as the default - if you don't do this libpng 1.6 will issue a warning. 2426 * 2427 * If you want unhandled unknown chunks to be discarded in libpng 1.6 and 2428 * earlier simply return '1' (handled). 2429 * 2430 * PNG_HANDLE_AS_UNKNOWN_SUPPORTED: 2431 * If this is *not* set known chunks will always be handled by libpng and 2432 * will never be stored in the unknown chunk list. Known chunks listed to 2433 * png_set_keep_unknown_chunks will have no effect. If it is set then known 2434 * chunks listed with a keep other than AS_DEFAULT will *never* be processed 2435 * by libpng, in addition critical chunks must either be processed by the 2436 * callback or saved. 2437 * 2438 * The IHDR and IEND chunks must not be listed. Because this turns off the 2439 * default handling for chunks that would otherwise be recognized the 2440 * behavior of libpng transformations may well become incorrect! 2441 * 2442 * WRITE: 2443 * When writing chunks the options only apply to the chunks specified by 2444 * png_set_unknown_chunks (below), libpng will *always* write known chunks 2445 * required by png_set_ calls and will always write the core critical chunks 2446 * (as required for PLTE). 2447 * 2448 * Each chunk in the png_set_unknown_chunks list is looked up in the 2449 * png_set_keep_unknown_chunks list to find the keep setting, this is then 2450 * interpreted as follows: 2451 * 2452 * PNG_HANDLE_CHUNK_AS_DEFAULT: 2453 * Write safe-to-copy chunks and write other chunks if the global 2454 * default is set to _ALWAYS, otherwise don't write this chunk. 2455 * PNG_HANDLE_CHUNK_NEVER: 2456 * Do not write the chunk. 2457 * PNG_HANDLE_CHUNK_IF_SAFE: 2458 * Write the chunk if it is safe-to-copy, otherwise do not write it. 2459 * PNG_HANDLE_CHUNK_ALWAYS: 2460 * Write the chunk. 2461 * 2462 * Note that the default behavior is effectively the opposite of the read case - 2463 * in read unknown chunks are not stored by default, in write they are written 2464 * by default. Also the behavior of PNG_HANDLE_CHUNK_IF_SAFE is very different 2465 * - on write the safe-to-copy bit is checked, on read the critical bit is 2466 * checked and on read if the chunk is critical an error will be raised. 2467 * 2468 * num_chunks: 2469 * =========== 2470 * If num_chunks is positive, then the "keep" parameter specifies the manner 2471 * for handling only those chunks appearing in the chunk_list array, 2472 * otherwise the chunk list array is ignored. 2473 * 2474 * If num_chunks is 0 the "keep" parameter specifies the default behavior for 2475 * unknown chunks, as described above. 2476 * 2477 * If num_chunks is negative, then the "keep" parameter specifies the manner 2478 * for handling all unknown chunks plus all chunks recognized by libpng 2479 * except for the IHDR, PLTE, tRNS, IDAT, and IEND chunks (which continue to 2480 * be processed by libpng. 2481 */ 2482 PNG_EXPORT(172, void, png_set_keep_unknown_chunks, (png_structrp png_ptr, 2483 int keep, png_const_bytep chunk_list, int num_chunks)); 2484 2485 /* The "keep" PNG_HANDLE_CHUNK_ parameter for the specified chunk is returned; 2486 * the result is therefore true (non-zero) if special handling is required, 2487 * false for the default handling. 2488 */ 2489 PNG_EXPORT(173, int, png_handle_as_unknown, (png_const_structrp png_ptr, 2490 png_const_bytep chunk_name)); 2491 #endif 2492 2493 #ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED 2494 PNG_EXPORT(174, void, png_set_unknown_chunks, (png_const_structrp png_ptr, 2495 png_inforp info_ptr, png_const_unknown_chunkp unknowns, 2496 int num_unknowns)); 2497 /* NOTE: prior to 1.6.0 this routine set the 'location' field of the added 2498 * unknowns to the location currently stored in the png_struct. This is 2499 * invariably the wrong value on write. To fix this call the following API 2500 * for each chunk in the list with the correct location. If you know your 2501 * code won't be compiled on earlier versions you can rely on 2502 * png_set_unknown_chunks(write-ptr, png_get_unknown_chunks(read-ptr)) doing 2503 * the correct thing. 2504 */ 2505 2506 PNG_EXPORT(175, void, png_set_unknown_chunk_location, 2507 (png_const_structrp png_ptr, png_inforp info_ptr, int chunk, int location)); 2508 2509 PNG_EXPORT(176, int, png_get_unknown_chunks, (png_const_structrp png_ptr, 2510 png_inforp info_ptr, png_unknown_chunkpp entries)); 2511 #endif 2512 2513 /* Png_free_data() will turn off the "valid" flag for anything it frees. 2514 * If you need to turn it off for a chunk that your application has freed, 2515 * you can use png_set_invalid(png_ptr, info_ptr, PNG_INFO_CHNK); 2516 */ 2517 PNG_EXPORT(177, void, png_set_invalid, (png_const_structrp png_ptr, 2518 png_inforp info_ptr, int mask)); 2519 2520 #ifdef PNG_INFO_IMAGE_SUPPORTED 2521 /* The "params" pointer is currently not used and is for future expansion. */ 2522 PNG_EXPORT(178, void, png_read_png, (png_structrp png_ptr, png_inforp info_ptr, 2523 int transforms, png_voidp params)); 2524 PNG_EXPORT(179, void, png_write_png, (png_structrp png_ptr, png_inforp info_ptr, 2525 int transforms, png_voidp params)); 2526 #endif 2527 2528 PNG_EXPORT(180, png_const_charp, png_get_copyright, 2529 (png_const_structrp png_ptr)); 2530 PNG_EXPORT(181, png_const_charp, png_get_header_ver, 2531 (png_const_structrp png_ptr)); 2532 PNG_EXPORT(182, png_const_charp, png_get_header_version, 2533 (png_const_structrp png_ptr)); 2534 PNG_EXPORT(183, png_const_charp, png_get_libpng_ver, 2535 (png_const_structrp png_ptr)); 2536 2537 #ifdef PNG_MNG_FEATURES_SUPPORTED 2538 PNG_EXPORT(184, png_uint_32, png_permit_mng_features, (png_structrp png_ptr, 2539 png_uint_32 mng_features_permitted)); 2540 #endif 2541 2542 /* For use in png_set_keep_unknown, added to version 1.2.6 */ 2543 #define PNG_HANDLE_CHUNK_AS_DEFAULT 0 2544 #define PNG_HANDLE_CHUNK_NEVER 1 2545 #define PNG_HANDLE_CHUNK_IF_SAFE 2 2546 #define PNG_HANDLE_CHUNK_ALWAYS 3 2547 #define PNG_HANDLE_CHUNK_LAST 4 2548 2549 /* Strip the prepended error numbers ("#nnn ") from error and warning 2550 * messages before passing them to the error or warning handler. 2551 */ 2552 #ifdef PNG_ERROR_NUMBERS_SUPPORTED 2553 PNG_EXPORT(185, void, png_set_strip_error_numbers, (png_structrp png_ptr, 2554 png_uint_32 strip_mode)); 2555 #endif 2556 2557 /* Added in libpng-1.2.6 */ 2558 #ifdef PNG_SET_USER_LIMITS_SUPPORTED 2559 PNG_EXPORT(186, void, png_set_user_limits, (png_structrp png_ptr, 2560 png_uint_32 user_width_max, png_uint_32 user_height_max)); 2561 PNG_EXPORT(187, png_uint_32, png_get_user_width_max, 2562 (png_const_structrp png_ptr)); 2563 PNG_EXPORT(188, png_uint_32, png_get_user_height_max, 2564 (png_const_structrp png_ptr)); 2565 /* Added in libpng-1.4.0 */ 2566 PNG_EXPORT(189, void, png_set_chunk_cache_max, (png_structrp png_ptr, 2567 png_uint_32 user_chunk_cache_max)); 2568 PNG_EXPORT(190, png_uint_32, png_get_chunk_cache_max, 2569 (png_const_structrp png_ptr)); 2570 /* Added in libpng-1.4.1 */ 2571 PNG_EXPORT(191, void, png_set_chunk_malloc_max, (png_structrp png_ptr, 2572 png_alloc_size_t user_chunk_cache_max)); 2573 PNG_EXPORT(192, png_alloc_size_t, png_get_chunk_malloc_max, 2574 (png_const_structrp png_ptr)); 2575 #endif 2576 2577 #if defined(PNG_INCH_CONVERSIONS_SUPPORTED) 2578 PNG_EXPORT(193, png_uint_32, png_get_pixels_per_inch, 2579 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 2580 2581 PNG_EXPORT(194, png_uint_32, png_get_x_pixels_per_inch, 2582 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 2583 2584 PNG_EXPORT(195, png_uint_32, png_get_y_pixels_per_inch, 2585 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 2586 2587 PNG_FP_EXPORT(196, float, png_get_x_offset_inches, 2588 (png_const_structrp png_ptr, png_const_inforp info_ptr)) 2589 #ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */ 2590 PNG_FIXED_EXPORT(211, png_fixed_point, png_get_x_offset_inches_fixed, 2591 (png_const_structrp png_ptr, png_const_inforp info_ptr)) 2592 #endif 2593 2594 PNG_FP_EXPORT(197, float, png_get_y_offset_inches, (png_const_structrp png_ptr, 2595 png_const_inforp info_ptr)) 2596 #ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */ 2597 PNG_FIXED_EXPORT(212, png_fixed_point, png_get_y_offset_inches_fixed, 2598 (png_const_structrp png_ptr, png_const_inforp info_ptr)) 2599 #endif 2600 2601 # ifdef PNG_pHYs_SUPPORTED 2602 PNG_EXPORT(198, png_uint_32, png_get_pHYs_dpi, (png_const_structrp png_ptr, 2603 png_const_inforp info_ptr, png_uint_32 *res_x, png_uint_32 *res_y, 2604 int *unit_type)); 2605 # endif /* PNG_pHYs_SUPPORTED */ 2606 #endif /* PNG_INCH_CONVERSIONS_SUPPORTED */ 2607 2608 /* Added in libpng-1.4.0 */ 2609 #ifdef PNG_IO_STATE_SUPPORTED 2610 PNG_EXPORT(199, png_uint_32, png_get_io_state, (png_const_structrp png_ptr)); 2611 2612 /* Removed from libpng 1.6; use png_get_io_chunk_type. */ 2613 PNG_REMOVED(200, png_const_bytep, png_get_io_chunk_name, (png_structrp png_ptr), 2614 PNG_DEPRECATED) 2615 2616 PNG_EXPORT(216, png_uint_32, png_get_io_chunk_type, 2617 (png_const_structrp png_ptr)); 2618 2619 /* The flags returned by png_get_io_state() are the following: */ 2620 # define PNG_IO_NONE 0x0000 /* no I/O at this moment */ 2621 # define PNG_IO_READING 0x0001 /* currently reading */ 2622 # define PNG_IO_WRITING 0x0002 /* currently writing */ 2623 # define PNG_IO_SIGNATURE 0x0010 /* currently at the file signature */ 2624 # define PNG_IO_CHUNK_HDR 0x0020 /* currently at the chunk header */ 2625 # define PNG_IO_CHUNK_DATA 0x0040 /* currently at the chunk data */ 2626 # define PNG_IO_CHUNK_CRC 0x0080 /* currently at the chunk crc */ 2627 # define PNG_IO_MASK_OP 0x000f /* current operation: reading/writing */ 2628 # define PNG_IO_MASK_LOC 0x00f0 /* current location: sig/hdr/data/crc */ 2629 #endif /* ?PNG_IO_STATE_SUPPORTED */ 2630 2631 /* Interlace support. The following macros are always defined so that if 2632 * libpng interlace handling is turned off the macros may be used to handle 2633 * interlaced images within the application. 2634 */ 2635 #define PNG_INTERLACE_ADAM7_PASSES 7 2636 2637 /* Two macros to return the first row and first column of the original, 2638 * full, image which appears in a given pass. 'pass' is in the range 0 2639 * to 6 and the result is in the range 0 to 7. 2640 */ 2641 #define PNG_PASS_START_ROW(pass) (((1&~(pass))<<(3-((pass)>>1)))&7) 2642 #define PNG_PASS_START_COL(pass) (((1& (pass))<<(3-(((pass)+1)>>1)))&7) 2643 2644 /* A macro to return the offset between pixels in the output row for a pair of 2645 * pixels in the input - effectively the inverse of the 'COL_SHIFT' macro that 2646 * follows. Note that ROW_OFFSET is the offset from one row to the next whereas 2647 * COL_OFFSET is from one column to the next, within a row. 2648 */ 2649 #define PNG_PASS_ROW_OFFSET(pass) ((pass)>2?(8>>(((pass)-1)>>1)):8) 2650 #define PNG_PASS_COL_OFFSET(pass) (1<<((7-(pass))>>1)) 2651 2652 /* Two macros to help evaluate the number of rows or columns in each 2653 * pass. This is expressed as a shift - effectively log2 of the number or 2654 * rows or columns in each 8x8 tile of the original image. 2655 */ 2656 #define PNG_PASS_ROW_SHIFT(pass) ((pass)>2?(8-(pass))>>1:3) 2657 #define PNG_PASS_COL_SHIFT(pass) ((pass)>1?(7-(pass))>>1:3) 2658 2659 /* Hence two macros to determine the number of rows or columns in a given 2660 * pass of an image given its height or width. In fact these macros may 2661 * return non-zero even though the sub-image is empty, because the other 2662 * dimension may be empty for a small image. 2663 */ 2664 #define PNG_PASS_ROWS(height, pass) (((height)+(((1<<PNG_PASS_ROW_SHIFT(pass))\ 2665 -1)-PNG_PASS_START_ROW(pass)))>>PNG_PASS_ROW_SHIFT(pass)) 2666 #define PNG_PASS_COLS(width, pass) (((width)+(((1<<PNG_PASS_COL_SHIFT(pass))\ 2667 -1)-PNG_PASS_START_COL(pass)))>>PNG_PASS_COL_SHIFT(pass)) 2668 2669 /* For the reader row callbacks (both progressive and sequential) it is 2670 * necessary to find the row in the output image given a row in an interlaced 2671 * image, so two more macros: 2672 */ 2673 #define PNG_ROW_FROM_PASS_ROW(y_in, pass) \ 2674 (((y_in)<<PNG_PASS_ROW_SHIFT(pass))+PNG_PASS_START_ROW(pass)) 2675 #define PNG_COL_FROM_PASS_COL(x_in, pass) \ 2676 (((x_in)<<PNG_PASS_COL_SHIFT(pass))+PNG_PASS_START_COL(pass)) 2677 2678 /* Two macros which return a boolean (0 or 1) saying whether the given row 2679 * or column is in a particular pass. These use a common utility macro that 2680 * returns a mask for a given pass - the offset 'off' selects the row or 2681 * column version. The mask has the appropriate bit set for each column in 2682 * the tile. 2683 */ 2684 #define PNG_PASS_MASK(pass,off) ( \ 2685 ((0x110145AF>>(((7-(off))-(pass))<<2)) & 0xF) | \ 2686 ((0x01145AF0>>(((7-(off))-(pass))<<2)) & 0xF0)) 2687 2688 #define PNG_ROW_IN_INTERLACE_PASS(y, pass) \ 2689 ((PNG_PASS_MASK(pass,0) >> ((y)&7)) & 1) 2690 #define PNG_COL_IN_INTERLACE_PASS(x, pass) \ 2691 ((PNG_PASS_MASK(pass,1) >> ((x)&7)) & 1) 2692 2693 #ifdef PNG_READ_COMPOSITE_NODIV_SUPPORTED 2694 /* With these routines we avoid an integer divide, which will be slower on 2695 * most machines. However, it does take more operations than the corresponding 2696 * divide method, so it may be slower on a few RISC systems. There are two 2697 * shifts (by 8 or 16 bits) and an addition, versus a single integer divide. 2698 * 2699 * Note that the rounding factors are NOT supposed to be the same! 128 and 2700 * 32768 are correct for the NODIV code; 127 and 32767 are correct for the 2701 * standard method. 2702 * 2703 * [Optimized code by Greg Roelofs and Mark Adler...blame us for bugs. :-) ] 2704 */ 2705 2706 /* fg and bg should be in `gamma 1.0' space; alpha is the opacity */ 2707 2708 # define png_composite(composite, fg, alpha, bg) \ 2709 { png_uint_16 temp = (png_uint_16)((png_uint_16)(fg) \ 2710 * (png_uint_16)(alpha) \ 2711 + (png_uint_16)(bg)*(png_uint_16)(255 \ 2712 - (png_uint_16)(alpha)) + 128); \ 2713 (composite) = (png_byte)((temp + (temp >> 8)) >> 8); } 2714 2715 # define png_composite_16(composite, fg, alpha, bg) \ 2716 { png_uint_32 temp = (png_uint_32)((png_uint_32)(fg) \ 2717 * (png_uint_32)(alpha) \ 2718 + (png_uint_32)(bg)*(65535 \ 2719 - (png_uint_32)(alpha)) + 32768); \ 2720 (composite) = (png_uint_16)((temp + (temp >> 16)) >> 16); } 2721 2722 #else /* Standard method using integer division */ 2723 2724 # define png_composite(composite, fg, alpha, bg) \ 2725 (composite) = (png_byte)(((png_uint_16)(fg) * (png_uint_16)(alpha) + \ 2726 (png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) + \ 2727 127) / 255) 2728 2729 # define png_composite_16(composite, fg, alpha, bg) \ 2730 (composite) = (png_uint_16)(((png_uint_32)(fg) * (png_uint_32)(alpha) + \ 2731 (png_uint_32)(bg)*(png_uint_32)(65535 - (png_uint_32)(alpha)) + \ 2732 32767) / 65535) 2733 #endif /* PNG_READ_COMPOSITE_NODIV_SUPPORTED */ 2734 2735 #ifdef PNG_READ_INT_FUNCTIONS_SUPPORTED 2736 PNG_EXPORT(201, png_uint_32, png_get_uint_32, (png_const_bytep buf)); 2737 PNG_EXPORT(202, png_uint_16, png_get_uint_16, (png_const_bytep buf)); 2738 PNG_EXPORT(203, png_int_32, png_get_int_32, (png_const_bytep buf)); 2739 #endif 2740 2741 PNG_EXPORT(204, png_uint_32, png_get_uint_31, (png_const_structrp png_ptr, 2742 png_const_bytep buf)); 2743 /* No png_get_int_16 -- may be added if there's a real need for it. */ 2744 2745 /* Place a 32-bit number into a buffer in PNG byte order (big-endian). */ 2746 #ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED 2747 PNG_EXPORT(205, void, png_save_uint_32, (png_bytep buf, png_uint_32 i)); 2748 #endif 2749 #ifdef PNG_SAVE_INT_32_SUPPORTED 2750 PNG_EXPORT(206, void, png_save_int_32, (png_bytep buf, png_int_32 i)); 2751 #endif 2752 2753 /* Place a 16-bit number into a buffer in PNG byte order. 2754 * The parameter is declared unsigned int, not png_uint_16, 2755 * just to avoid potential problems on pre-ANSI C compilers. 2756 */ 2757 #ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED 2758 PNG_EXPORT(207, void, png_save_uint_16, (png_bytep buf, unsigned int i)); 2759 /* No png_save_int_16 -- may be added if there's a real need for it. */ 2760 #endif 2761 2762 #ifdef PNG_USE_READ_MACROS 2763 /* Inline macros to do direct reads of bytes from the input buffer. 2764 * The png_get_int_32() routine assumes we are using two's complement 2765 * format for negative values, which is almost certainly true. 2766 */ 2767 # define PNG_get_uint_32(buf) \ 2768 (((png_uint_32)(*(buf)) << 24) + \ 2769 ((png_uint_32)(*((buf) + 1)) << 16) + \ 2770 ((png_uint_32)(*((buf) + 2)) << 8) + \ 2771 ((png_uint_32)(*((buf) + 3)))) 2772 2773 /* From libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the 2774 * function) incorrectly returned a value of type png_uint_32. 2775 */ 2776 # define PNG_get_uint_16(buf) \ 2777 ((png_uint_16) \ 2778 (((unsigned int)(*(buf)) << 8) + \ 2779 ((unsigned int)(*((buf) + 1))))) 2780 2781 # define PNG_get_int_32(buf) \ 2782 ((png_int_32)((*(buf) & 0x80) \ 2783 ? -((png_int_32)((png_get_uint_32(buf) ^ 0xffffffffL) + 1)) \ 2784 : (png_int_32)png_get_uint_32(buf))) 2785 2786 /* If PNG_PREFIX is defined the same thing as below happens in pnglibconf.h, 2787 * but defining a macro name prefixed with PNG_PREFIX. 2788 */ 2789 # ifndef PNG_PREFIX 2790 # define png_get_uint_32(buf) PNG_get_uint_32(buf) 2791 # define png_get_uint_16(buf) PNG_get_uint_16(buf) 2792 # define png_get_int_32(buf) PNG_get_int_32(buf) 2793 # endif 2794 #else 2795 # ifdef PNG_PREFIX 2796 /* No macros; revert to the (redefined) function */ 2797 # define PNG_get_uint_32 (png_get_uint_32) 2798 # define PNG_get_uint_16 (png_get_uint_16) 2799 # define PNG_get_int_32 (png_get_int_32) 2800 # endif 2801 #endif 2802 2803 /******************************************************************************* 2804 * SIMPLIFIED API 2805 ******************************************************************************* 2806 * 2807 * Please read the documentation in libpng-manual.txt (TODO: write said 2808 * documentation) if you don't understand what follows. 2809 * 2810 * The simplified API hides the details of both libpng and the PNG file format 2811 * itself. It allows PNG files to be read into a very limited number of 2812 * in-memory bitmap formats or to be written from the same formats. If these 2813 * formats do not accomodate your needs then you can, and should, use the more 2814 * sophisticated APIs above - these support a wide variety of in-memory formats 2815 * and a wide variety of sophisticated transformations to those formats as well 2816 * as a wide variety of APIs to manipulate ancillary information. 2817 * 2818 * To read a PNG file using the simplified API: 2819 * 2820 * 1) Declare a 'png_image' structure (see below) on the stack and set the 2821 * version field to PNG_IMAGE_VERSION. 2822 * 2) Call the appropriate png_image_begin_read... function. 2823 * 3) Set the png_image 'format' member to the required sample format. 2824 * 4) Allocate a buffer for the image and, if required, the color-map. 2825 * 5) Call png_image_finish_read to read the image and, if required, the 2826 * color-map into your buffers. 2827 * 2828 * There are no restrictions on the format of the PNG input itself; all valid 2829 * color types, bit depths, and interlace methods are acceptable, and the 2830 * input image is transformed as necessary to the requested in-memory format 2831 * during the png_image_finish_read() step. The only caveat is that if you 2832 * request a color-mapped image from a PNG that is full-color or makes 2833 * complex use of an alpha channel the transformation is extremely lossy and the 2834 * result may look terrible. 2835 * 2836 * To write a PNG file using the simplified API: 2837 * 2838 * 1) Declare a 'png_image' structure on the stack and memset() it to all zero. 2839 * 2) Initialize the members of the structure that describe the image, setting 2840 * the 'format' member to the format of the image samples. 2841 * 3) Call the appropriate png_image_write... function with a pointer to the 2842 * image and, if necessary, the color-map to write the PNG data. 2843 * 2844 * png_image is a structure that describes the in-memory format of an image 2845 * when it is being read or defines the in-memory format of an image that you 2846 * need to write: 2847 */ 2848 #define PNG_IMAGE_VERSION 1 2849 2850 typedef struct png_control *png_controlp; 2851 typedef struct 2852 { 2853 png_controlp opaque; /* Initialize to NULL, free with png_image_free */ 2854 png_uint_32 version; /* Set to PNG_IMAGE_VERSION */ 2855 png_uint_32 width; /* Image width in pixels (columns) */ 2856 png_uint_32 height; /* Image height in pixels (rows) */ 2857 png_uint_32 format; /* Image format as defined below */ 2858 png_uint_32 flags; /* A bit mask containing informational flags */ 2859 png_uint_32 colormap_entries; 2860 /* Number of entries in the color-map */ 2861 2862 /* In the event of an error or warning the following field will be set to a 2863 * non-zero value and the 'message' field will contain a '\0' terminated 2864 * string with the libpng error or warning message. If both warnings and 2865 * an error were encountered, only the error is recorded. If there 2866 * are multiple warnings, only the first one is recorded. 2867 * 2868 * The upper 30 bits of this value are reserved, the low two bits contain 2869 * a value as follows: 2870 */ 2871 # define PNG_IMAGE_WARNING 1 2872 # define PNG_IMAGE_ERROR 2 2873 /* 2874 * The result is a two bit code such that a value more than 1 indicates 2875 * a failure in the API just called: 2876 * 2877 * 0 - no warning or error 2878 * 1 - warning 2879 * 2 - error 2880 * 3 - error preceded by warning 2881 */ 2882 # define PNG_IMAGE_FAILED(png_cntrl) ((((png_cntrl).warning_or_error)&0x03)>1) 2883 2884 png_uint_32 warning_or_error; 2885 2886 char message[64]; 2887 } png_image, *png_imagep; 2888 2889 /* The samples of the image have one to four channels whose components have 2890 * original values in the range 0 to 1.0: 2891 * 2892 * 1: A single gray or luminance channel (G). 2893 * 2: A gray/luminance channel and an alpha channel (GA). 2894 * 3: Three red, green, blue color channels (RGB). 2895 * 4: Three color channels and an alpha channel (RGBA). 2896 * 2897 * The components are encoded in one of two ways: 2898 * 2899 * a) As a small integer, value 0..255, contained in a single byte. For the 2900 * alpha channel the original value is simply value/255. For the color or 2901 * luminance channels the value is encoded according to the sRGB specification 2902 * and matches the 8-bit format expected by typical display devices. 2903 * 2904 * The color/gray channels are not scaled (pre-multiplied) by the alpha 2905 * channel and are suitable for passing to color management software. 2906 * 2907 * b) As a value in the range 0..65535, contained in a 2-byte integer. All 2908 * channels can be converted to the original value by dividing by 65535; all 2909 * channels are linear. Color channels use the RGB encoding (RGB end-points) of 2910 * the sRGB specification. This encoding is identified by the 2911 * PNG_FORMAT_FLAG_LINEAR flag below. 2912 * 2913 * When the simplified API needs to convert between sRGB and linear colorspaces, 2914 * the actual sRGB transfer curve defined in the sRGB specification (see the 2915 * article at http://en.wikipedia.org/wiki/SRGB) is used, not the gamma=1/2.2 2916 * approximation used elsewhere in libpng. 2917 * 2918 * When an alpha channel is present it is expected to denote pixel coverage 2919 * of the color or luminance channels and is returned as an associated alpha 2920 * channel: the color/gray channels are scaled (pre-multiplied) by the alpha 2921 * value. 2922 * 2923 * The samples are either contained directly in the image data, between 1 and 8 2924 * bytes per pixel according to the encoding, or are held in a color-map indexed 2925 * by bytes in the image data. In the case of a color-map the color-map entries 2926 * are individual samples, encoded as above, and the image data has one byte per 2927 * pixel to select the relevant sample from the color-map. 2928 */ 2929 2930 /* PNG_FORMAT_* 2931 * 2932 * #defines to be used in png_image::format. Each #define identifies a 2933 * particular layout of sample data and, if present, alpha values. There are 2934 * separate defines for each of the two component encodings. 2935 * 2936 * A format is built up using single bit flag values. All combinations are 2937 * valid. Formats can be built up from the flag values or you can use one of 2938 * the predefined values below. When testing formats always use the FORMAT_FLAG 2939 * macros to test for individual features - future versions of the library may 2940 * add new flags. 2941 * 2942 * When reading or writing color-mapped images the format should be set to the 2943 * format of the entries in the color-map then png_image_{read,write}_colormap 2944 * called to read or write the color-map and set the format correctly for the 2945 * image data. Do not set the PNG_FORMAT_FLAG_COLORMAP bit directly! 2946 * 2947 * NOTE: libpng can be built with particular features disabled, if you see 2948 * compiler errors because the definition of one of the following flags has been 2949 * compiled out it is because libpng does not have the required support. It is 2950 * possible, however, for the libpng configuration to enable the format on just 2951 * read or just write; in that case you may see an error at run time. You can 2952 * guard against this by checking for the definition of the appropriate 2953 * "_SUPPORTED" macro, one of: 2954 * 2955 * PNG_SIMPLIFIED_{READ,WRITE}_{BGR,AFIRST}_SUPPORTED 2956 */ 2957 #define PNG_FORMAT_FLAG_ALPHA 0x01U /* format with an alpha channel */ 2958 #define PNG_FORMAT_FLAG_COLOR 0x02U /* color format: otherwise grayscale */ 2959 #define PNG_FORMAT_FLAG_LINEAR 0x04U /* 2 byte channels else 1 byte */ 2960 #define PNG_FORMAT_FLAG_COLORMAP 0x08U /* image data is color-mapped */ 2961 2962 #ifdef PNG_FORMAT_BGR_SUPPORTED 2963 # define PNG_FORMAT_FLAG_BGR 0x10U /* BGR colors, else order is RGB */ 2964 #endif 2965 2966 #ifdef PNG_FORMAT_AFIRST_SUPPORTED 2967 # define PNG_FORMAT_FLAG_AFIRST 0x20U /* alpha channel comes first */ 2968 #endif 2969 2970 /* Commonly used formats have predefined macros. 2971 * 2972 * First the single byte (sRGB) formats: 2973 */ 2974 #define PNG_FORMAT_GRAY 0 2975 #define PNG_FORMAT_GA PNG_FORMAT_FLAG_ALPHA 2976 #define PNG_FORMAT_AG (PNG_FORMAT_GA|PNG_FORMAT_FLAG_AFIRST) 2977 #define PNG_FORMAT_RGB PNG_FORMAT_FLAG_COLOR 2978 #define PNG_FORMAT_BGR (PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_BGR) 2979 #define PNG_FORMAT_RGBA (PNG_FORMAT_RGB|PNG_FORMAT_FLAG_ALPHA) 2980 #define PNG_FORMAT_ARGB (PNG_FORMAT_RGBA|PNG_FORMAT_FLAG_AFIRST) 2981 #define PNG_FORMAT_BGRA (PNG_FORMAT_BGR|PNG_FORMAT_FLAG_ALPHA) 2982 #define PNG_FORMAT_ABGR (PNG_FORMAT_BGRA|PNG_FORMAT_FLAG_AFIRST) 2983 2984 /* Then the linear 2-byte formats. When naming these "Y" is used to 2985 * indicate a luminance (gray) channel. 2986 */ 2987 #define PNG_FORMAT_LINEAR_Y PNG_FORMAT_FLAG_LINEAR 2988 #define PNG_FORMAT_LINEAR_Y_ALPHA (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_ALPHA) 2989 #define PNG_FORMAT_LINEAR_RGB (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR) 2990 #define PNG_FORMAT_LINEAR_RGB_ALPHA \ 2991 (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_ALPHA) 2992 2993 /* With color-mapped formats the image data is one byte for each pixel, the byte 2994 * is an index into the color-map which is formatted as above. To obtain a 2995 * color-mapped format it is sufficient just to add the PNG_FOMAT_FLAG_COLORMAP 2996 * to one of the above definitions, or you can use one of the definitions below. 2997 */ 2998 #define PNG_FORMAT_RGB_COLORMAP (PNG_FORMAT_RGB|PNG_FORMAT_FLAG_COLORMAP) 2999 #define PNG_FORMAT_BGR_COLORMAP (PNG_FORMAT_BGR|PNG_FORMAT_FLAG_COLORMAP) 3000 #define PNG_FORMAT_RGBA_COLORMAP (PNG_FORMAT_RGBA|PNG_FORMAT_FLAG_COLORMAP) 3001 #define PNG_FORMAT_ARGB_COLORMAP (PNG_FORMAT_ARGB|PNG_FORMAT_FLAG_COLORMAP) 3002 #define PNG_FORMAT_BGRA_COLORMAP (PNG_FORMAT_BGRA|PNG_FORMAT_FLAG_COLORMAP) 3003 #define PNG_FORMAT_ABGR_COLORMAP (PNG_FORMAT_ABGR|PNG_FORMAT_FLAG_COLORMAP) 3004 3005 /* PNG_IMAGE macros 3006 * 3007 * These are convenience macros to derive information from a png_image 3008 * structure. The PNG_IMAGE_SAMPLE_ macros return values appropriate to the 3009 * actual image sample values - either the entries in the color-map or the 3010 * pixels in the image. The PNG_IMAGE_PIXEL_ macros return corresponding values 3011 * for the pixels and will always return 1 for color-mapped formats. The 3012 * remaining macros return information about the rows in the image and the 3013 * complete image. 3014 * 3015 * NOTE: All the macros that take a png_image::format parameter are compile time 3016 * constants if the format parameter is, itself, a constant. Therefore these 3017 * macros can be used in array declarations and case labels where required. 3018 * Similarly the macros are also pre-processor constants (sizeof is not used) so 3019 * they can be used in #if tests. 3020 * 3021 * First the information about the samples. 3022 */ 3023 #define PNG_IMAGE_SAMPLE_CHANNELS(fmt)\ 3024 (((fmt)&(PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_ALPHA))+1) 3025 /* Return the total number of channels in a given format: 1..4 */ 3026 3027 #define PNG_IMAGE_SAMPLE_COMPONENT_SIZE(fmt)\ 3028 ((((fmt) & PNG_FORMAT_FLAG_LINEAR) >> 2)+1) 3029 /* Return the size in bytes of a single component of a pixel or color-map 3030 * entry (as appropriate) in the image: 1 or 2. 3031 */ 3032 3033 #define PNG_IMAGE_SAMPLE_SIZE(fmt)\ 3034 (PNG_IMAGE_SAMPLE_CHANNELS(fmt) * PNG_IMAGE_SAMPLE_COMPONENT_SIZE(fmt)) 3035 /* This is the size of the sample data for one sample. If the image is 3036 * color-mapped it is the size of one color-map entry (and image pixels are 3037 * one byte in size), otherwise it is the size of one image pixel. 3038 */ 3039 3040 #define PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(fmt)\ 3041 (PNG_IMAGE_SAMPLE_CHANNELS(fmt) * 256) 3042 /* The maximum size of the color-map required by the format expressed in a 3043 * count of components. This can be used to compile-time allocate a 3044 * color-map: 3045 * 3046 * png_uint_16 colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(linear_fmt)]; 3047 * 3048 * png_byte colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(sRGB_fmt)]; 3049 * 3050 * Alternatively use the PNG_IMAGE_COLORMAP_SIZE macro below to use the 3051 * information from one of the png_image_begin_read_ APIs and dynamically 3052 * allocate the required memory. 3053 */ 3054 3055 /* Corresponding information about the pixels */ 3056 #define PNG_IMAGE_PIXEL_(test,fmt)\ 3057 (((fmt)&PNG_FORMAT_FLAG_COLORMAP)?1:test(fmt)) 3058 3059 #define PNG_IMAGE_PIXEL_CHANNELS(fmt)\ 3060 PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_CHANNELS,fmt) 3061 /* The number of separate channels (components) in a pixel; 1 for a 3062 * color-mapped image. 3063 */ 3064 3065 #define PNG_IMAGE_PIXEL_COMPONENT_SIZE(fmt)\ 3066 PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_COMPONENT_SIZE,fmt) 3067 /* The size, in bytes, of each component in a pixel; 1 for a color-mapped 3068 * image. 3069 */ 3070 3071 #define PNG_IMAGE_PIXEL_SIZE(fmt) PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_SIZE,fmt) 3072 /* The size, in bytes, of a complete pixel; 1 for a color-mapped image. */ 3073 3074 /* Information about the whole row, or whole image */ 3075 #define PNG_IMAGE_ROW_STRIDE(image)\ 3076 (PNG_IMAGE_PIXEL_CHANNELS((image).format) * (image).width) 3077 /* Return the total number of components in a single row of the image; this 3078 * is the minimum 'row stride', the minimum count of components between each 3079 * row. For a color-mapped image this is the minimum number of bytes in a 3080 * row. 3081 */ 3082 3083 #define PNG_IMAGE_BUFFER_SIZE(image, row_stride)\ 3084 (PNG_IMAGE_PIXEL_COMPONENT_SIZE((image).format)*(image).height*(row_stride)) 3085 /* Return the size, in bytes, of an image buffer given a png_image and a row 3086 * stride - the number of components to leave space for in each row. 3087 */ 3088 3089 #define PNG_IMAGE_SIZE(image)\ 3090 PNG_IMAGE_BUFFER_SIZE(image, PNG_IMAGE_ROW_STRIDE(image)) 3091 /* Return the size, in bytes, of the image in memory given just a png_image; 3092 * the row stride is the minimum stride required for the image. 3093 */ 3094 3095 #define PNG_IMAGE_COLORMAP_SIZE(image)\ 3096 (PNG_IMAGE_SAMPLE_SIZE((image).format) * (image).colormap_entries) 3097 /* Return the size, in bytes, of the color-map of this image. If the image 3098 * format is not a color-map format this will return a size sufficient for 3099 * 256 entries in the given format; check PNG_FORMAT_FLAG_COLORMAP if 3100 * you don't want to allocate a color-map in this case. 3101 */ 3102 3103 /* PNG_IMAGE_FLAG_* 3104 * 3105 * Flags containing additional information about the image are held in the 3106 * 'flags' field of png_image. 3107 */ 3108 #define PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB 0x01 3109 /* This indicates the the RGB values of the in-memory bitmap do not 3110 * correspond to the red, green and blue end-points defined by sRGB. 3111 */ 3112 3113 #define PNG_IMAGE_FLAG_FAST 0x02 3114 /* On write emphasise speed over compression; the resultant PNG file will be 3115 * larger but will be produced significantly faster, particular for large 3116 * images. Do not use this option for images which will be distributed, only 3117 * used it when producing intermediate files that will be read back in 3118 * repeatedly. For a typical 24-bit image the option will double the read 3119 * speed at the cost of increasing the image size by 25%, however for many 3120 * more compressible images the PNG file can be 10 times larger with only a 3121 * slight speed gain. 3122 */ 3123 3124 #define PNG_IMAGE_FLAG_16BIT_sRGB 0x04 3125 /* On read if the image is a 16-bit per component image and there is no gAMA 3126 * or sRGB chunk assume that the components are sRGB encoded. Notice that 3127 * images output by the simplified API always have gamma information; setting 3128 * this flag only affects the interpretation of 16-bit images from an 3129 * external source. It is recommended that the application expose this flag 3130 * to the user; the user can normally easily recognize the difference between 3131 * linear and sRGB encoding. This flag has no effect on write - the data 3132 * passed to the write APIs must have the correct encoding (as defined 3133 * above.) 3134 * 3135 * If the flag is not set (the default) input 16-bit per component data is 3136 * assumed to be linear. 3137 * 3138 * NOTE: the flag can only be set after the png_image_begin_read_ call, 3139 * because that call initializes the 'flags' field. 3140 */ 3141 3142 #ifdef PNG_SIMPLIFIED_READ_SUPPORTED 3143 /* READ APIs 3144 * --------- 3145 * 3146 * The png_image passed to the read APIs must have been initialized by setting 3147 * the png_controlp field 'opaque' to NULL (or, safer, memset the whole thing.) 3148 */ 3149 #ifdef PNG_STDIO_SUPPORTED 3150 PNG_EXPORT(234, int, png_image_begin_read_from_file, (png_imagep image, 3151 const char *file_name)); 3152 /* The named file is opened for read and the image header is filled in 3153 * from the PNG header in the file. 3154 */ 3155 3156 PNG_EXPORT(235, int, png_image_begin_read_from_stdio, (png_imagep image, 3157 FILE* file)); 3158 /* The PNG header is read from the stdio FILE object. */ 3159 #endif /* PNG_STDIO_SUPPORTED */ 3160 3161 PNG_EXPORT(236, int, png_image_begin_read_from_memory, (png_imagep image, 3162 png_const_voidp memory, png_size_t size)); 3163 /* The PNG header is read from the given memory buffer. */ 3164 3165 PNG_EXPORT(237, int, png_image_finish_read, (png_imagep image, 3166 png_const_colorp background, void *buffer, png_int_32 row_stride, 3167 void *colormap)); 3168 /* Finish reading the image into the supplied buffer and clean up the 3169 * png_image structure. 3170 * 3171 * row_stride is the step, in byte or 2-byte units as appropriate, 3172 * between adjacent rows. A positive stride indicates that the top-most row 3173 * is first in the buffer - the normal top-down arrangement. A negative 3174 * stride indicates that the bottom-most row is first in the buffer. 3175 * 3176 * background need only be supplied if an alpha channel must be removed from 3177 * a png_byte format and the removal is to be done by compositing on a solid 3178 * color; otherwise it may be NULL and any composition will be done directly 3179 * onto the buffer. The value is an sRGB color to use for the background, 3180 * for grayscale output the green channel is used. 3181 * 3182 * background must be supplied when an alpha channel must be removed from a 3183 * single byte color-mapped output format, in other words if: 3184 * 3185 * 1) The original format from png_image_begin_read_from_* had 3186 * PNG_FORMAT_FLAG_ALPHA set. 3187 * 2) The format set by the application does not. 3188 * 3) The format set by the application has PNG_FORMAT_FLAG_COLORMAP set and 3189 * PNG_FORMAT_FLAG_LINEAR *not* set. 3190 * 3191 * For linear output removing the alpha channel is always done by compositing 3192 * on black and background is ignored. 3193 * 3194 * colormap must be supplied when PNG_FORMAT_FLAG_COLORMAP is set. It must 3195 * be at least the size (in bytes) returned by PNG_IMAGE_COLORMAP_SIZE. 3196 * image->colormap_entries will be updated to the actual number of entries 3197 * written to the colormap; this may be less than the original value. 3198 */ 3199 3200 PNG_EXPORT(238, void, png_image_free, (png_imagep image)); 3201 /* Free any data allocated by libpng in image->opaque, setting the pointer to 3202 * NULL. May be called at any time after the structure is initialized. 3203 */ 3204 #endif /* PNG_SIMPLIFIED_READ_SUPPORTED */ 3205 3206 #ifdef PNG_SIMPLIFIED_WRITE_SUPPORTED 3207 #ifdef PNG_STDIO_SUPPORTED 3208 /* WRITE APIS 3209 * ---------- 3210 * For write you must initialize a png_image structure to describe the image to 3211 * be written. To do this use memset to set the whole structure to 0 then 3212 * initialize fields describing your image. 3213 * 3214 * version: must be set to PNG_IMAGE_VERSION 3215 * opaque: must be initialized to NULL 3216 * width: image width in pixels 3217 * height: image height in rows 3218 * format: the format of the data (image and color-map) you wish to write 3219 * flags: set to 0 unless one of the defined flags applies; set 3220 * PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB for color format images where the RGB 3221 * values do not correspond to the colors in sRGB. 3222 * colormap_entries: set to the number of entries in the color-map (0 to 256) 3223 */ 3224 PNG_EXPORT(239, int, png_image_write_to_file, (png_imagep image, 3225 const char *file, int convert_to_8bit, const void *buffer, 3226 png_int_32 row_stride, const void *colormap)); 3227 /* Write the image to the named file. */ 3228 3229 PNG_EXPORT(240, int, png_image_write_to_stdio, (png_imagep image, FILE *file, 3230 int convert_to_8_bit, const void *buffer, png_int_32 row_stride, 3231 const void *colormap)); 3232 /* Write the image to the given (FILE*). */ 3233 3234 /* With both write APIs if image is in one of the linear formats with 16-bit 3235 * data then setting convert_to_8_bit will cause the output to be an 8-bit PNG 3236 * gamma encoded according to the sRGB specification, otherwise a 16-bit linear 3237 * encoded PNG file is written. 3238 * 3239 * With color-mapped data formats the colormap parameter point to a color-map 3240 * with at least image->colormap_entries encoded in the specified format. If 3241 * the format is linear the written PNG color-map will be converted to sRGB 3242 * regardless of the convert_to_8_bit flag. 3243 * 3244 * With all APIs row_stride is handled as in the read APIs - it is the spacing 3245 * from one row to the next in component sized units (1 or 2 bytes) and if 3246 * negative indicates a bottom-up row layout in the buffer. 3247 * 3248 * Note that the write API does not support interlacing or sub-8-bit pixels. 3249 */ 3250 #endif /* PNG_STDIO_SUPPORTED */ 3251 #endif /* PNG_SIMPLIFIED_WRITE_SUPPORTED */ 3252 /******************************************************************************* 3253 * END OF SIMPLIFIED API 3254 ******************************************************************************/ 3255 3256 #ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED 3257 PNG_EXPORT(242, void, png_set_check_for_invalid_index, 3258 (png_structrp png_ptr, int allowed)); 3259 # ifdef PNG_GET_PALETTE_MAX_SUPPORTED 3260 PNG_EXPORT(243, int, png_get_palette_max, (png_const_structp png_ptr, 3261 png_const_infop info_ptr)); 3262 # endif 3263 #endif /* CHECK_FOR_INVALID_INDEX */ 3264 3265 /******************************************************************************* 3266 * IMPLEMENTATION OPTIONS 3267 ******************************************************************************* 3268 * 3269 * Support for arbitrary implementation-specific optimizations. The API allows 3270 * particular options to be turned on or off. 'Option' is the number of the 3271 * option and 'onoff' is 0 (off) or non-0 (on). The value returned is given 3272 * by the PNG_OPTION_ defines below. 3273 * 3274 * HARDWARE: normally hardware capabilites, such as the Intel SSE instructions, 3275 * are detected at run time, however sometimes it may be impossible 3276 * to do this in user mode, in which case it is necessary to discover 3277 * the capabilities in an OS specific way. Such capabilities are 3278 * listed here when libpng has support for them and must be turned 3279 * ON by the application if present. 3280 * 3281 * SOFTWARE: sometimes software optimizations actually result in performance 3282 * decrease on some architectures or systems, or with some sets of 3283 * PNG images. 'Software' options allow such optimizations to be 3284 * selected at run time. 3285 */ 3286 #ifdef PNG_SET_OPTION_SUPPORTED 3287 #ifdef PNG_ARM_NEON_API_SUPPORTED 3288 # define PNG_ARM_NEON 0 /* HARDWARE: ARM Neon SIMD instructions supported */ 3289 #endif 3290 #define PNG_MAXIMUM_INFLATE_WINDOW 2 /* SOFTWARE: force maximum window */ 3291 #define PNG_OPTION_NEXT 4 /* Next option - numbers must be even */ 3292 3293 /* Return values: NOTE: there are four values and 'off' is *not* zero */ 3294 #define PNG_OPTION_UNSET 0 /* Unset - defaults to off */ 3295 #define PNG_OPTION_INVALID 1 /* Option number out of range */ 3296 #define PNG_OPTION_OFF 2 3297 #define PNG_OPTION_ON 3 3298 3299 PNG_EXPORT(244, int, png_set_option, (png_structrp png_ptr, int option, 3300 int onoff)); 3301 #endif 3302 3303 /******************************************************************************* 3304 * END OF HARDWARE OPTIONS 3305 ******************************************************************************/ 3306 3307 /* Maintainer: Put new public prototypes here ^, in libpng.3, and project 3308 * defs, scripts/pnglibconf.h, and scripts/pnglibconf.h.prebuilt 3309 */ 3310 3311 /* The last ordinal number (this is the *last* one already used; the next 3312 * one to use is one more than this.) Maintainer, remember to add an entry to 3313 * scripts/symbols.def as well. 3314 */ 3315 #ifdef PNG_EXPORT_LAST_ORDINAL 3316 PNG_EXPORT_LAST_ORDINAL(244); 3317 #endif 3318 3319 #ifdef __cplusplus 3320 } 3321 #endif 3322 3323 #endif /* PNG_VERSION_INFO_ONLY */ 3324 /* Do not put anything past this line */ 3325 #endif /* PNG_H */ 3326