1 2 /* png.h - header file for PNG reference library 3 * 4 * libpng version 1.6.12 - June 12, 2014 5 * Copyright (c) 1998-2014 Glenn Randers-Pehrson 6 * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) 7 * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) 8 * 9 * This code is released under the libpng license (See LICENSE, below) 10 * 11 * Authors and maintainers: 12 * libpng versions 0.71, May 1995, through 0.88, January 1996: Guy Schalnat 13 * libpng versions 0.89c, June 1996, through 0.96, May 1997: Andreas Dilger 14 * libpng versions 0.97, January 1998, through 1.6.12 - June 12, 2014: Glenn 15 * See also "Contributing Authors", below. 16 * 17 * Note about libpng version numbers: 18 * 19 * Due to various miscommunications, unforeseen code incompatibilities 20 * and occasional factors outside the authors' control, version numbering 21 * on the library has not always been consistent and straightforward. 22 * The following table summarizes matters since version 0.89c, which was 23 * the first widely used release: 24 * 25 * source png.h png.h shared-lib 26 * version string int version 27 * ------- ------ ----- ---------- 28 * 0.89c "1.0 beta 3" 0.89 89 1.0.89 29 * 0.90 "1.0 beta 4" 0.90 90 0.90 [should have been 2.0.90] 30 * 0.95 "1.0 beta 5" 0.95 95 0.95 [should have been 2.0.95] 31 * 0.96 "1.0 beta 6" 0.96 96 0.96 [should have been 2.0.96] 32 * 0.97b "1.00.97 beta 7" 1.00.97 97 1.0.1 [should have been 2.0.97] 33 * 0.97c 0.97 97 2.0.97 34 * 0.98 0.98 98 2.0.98 35 * 0.99 0.99 98 2.0.99 36 * 0.99a-m 0.99 99 2.0.99 37 * 1.00 1.00 100 2.1.0 [100 should be 10000] 38 * 1.0.0 (from here on, the 100 2.1.0 [100 should be 10000] 39 * 1.0.1 png.h string is 10001 2.1.0 40 * 1.0.1a-e identical to the 10002 from here on, the shared library 41 * 1.0.2 source version) 10002 is 2.V where V is the source code 42 * 1.0.2a-b 10003 version, except as noted. 43 * 1.0.3 10003 44 * 1.0.3a-d 10004 45 * 1.0.4 10004 46 * 1.0.4a-f 10005 47 * 1.0.5 (+ 2 patches) 10005 48 * 1.0.5a-d 10006 49 * 1.0.5e-r 10100 (not source compatible) 50 * 1.0.5s-v 10006 (not binary compatible) 51 * 1.0.6 (+ 3 patches) 10006 (still binary incompatible) 52 * 1.0.6d-f 10007 (still binary incompatible) 53 * 1.0.6g 10007 54 * 1.0.6h 10007 10.6h (testing xy.z so-numbering) 55 * 1.0.6i 10007 10.6i 56 * 1.0.6j 10007 2.1.0.6j (incompatible with 1.0.0) 57 * 1.0.7beta11-14 DLLNUM 10007 2.1.0.7beta11-14 (binary compatible) 58 * 1.0.7beta15-18 1 10007 2.1.0.7beta15-18 (binary compatible) 59 * 1.0.7rc1-2 1 10007 2.1.0.7rc1-2 (binary compatible) 60 * 1.0.7 1 10007 (still compatible) 61 * 1.0.8beta1-4 1 10008 2.1.0.8beta1-4 62 * 1.0.8rc1 1 10008 2.1.0.8rc1 63 * 1.0.8 1 10008 2.1.0.8 64 * 1.0.9beta1-6 1 10009 2.1.0.9beta1-6 65 * 1.0.9rc1 1 10009 2.1.0.9rc1 66 * 1.0.9beta7-10 1 10009 2.1.0.9beta7-10 67 * 1.0.9rc2 1 10009 2.1.0.9rc2 68 * 1.0.9 1 10009 2.1.0.9 69 * 1.0.10beta1 1 10010 2.1.0.10beta1 70 * 1.0.10rc1 1 10010 2.1.0.10rc1 71 * 1.0.10 1 10010 2.1.0.10 72 * 1.0.11beta1-3 1 10011 2.1.0.11beta1-3 73 * 1.0.11rc1 1 10011 2.1.0.11rc1 74 * 1.0.11 1 10011 2.1.0.11 75 * 1.0.12beta1-2 2 10012 2.1.0.12beta1-2 76 * 1.0.12rc1 2 10012 2.1.0.12rc1 77 * 1.0.12 2 10012 2.1.0.12 78 * 1.1.0a-f - 10100 2.1.1.0a-f (branch abandoned) 79 * 1.2.0beta1-2 2 10200 2.1.2.0beta1-2 80 * 1.2.0beta3-5 3 10200 3.1.2.0beta3-5 81 * 1.2.0rc1 3 10200 3.1.2.0rc1 82 * 1.2.0 3 10200 3.1.2.0 83 * 1.2.1beta1-4 3 10201 3.1.2.1beta1-4 84 * 1.2.1rc1-2 3 10201 3.1.2.1rc1-2 85 * 1.2.1 3 10201 3.1.2.1 86 * 1.2.2beta1-6 12 10202 12.so.0.1.2.2beta1-6 87 * 1.0.13beta1 10 10013 10.so.0.1.0.13beta1 88 * 1.0.13rc1 10 10013 10.so.0.1.0.13rc1 89 * 1.2.2rc1 12 10202 12.so.0.1.2.2rc1 90 * 1.0.13 10 10013 10.so.0.1.0.13 91 * 1.2.2 12 10202 12.so.0.1.2.2 92 * 1.2.3rc1-6 12 10203 12.so.0.1.2.3rc1-6 93 * 1.2.3 12 10203 12.so.0.1.2.3 94 * 1.2.4beta1-3 13 10204 12.so.0.1.2.4beta1-3 95 * 1.0.14rc1 13 10014 10.so.0.1.0.14rc1 96 * 1.2.4rc1 13 10204 12.so.0.1.2.4rc1 97 * 1.0.14 10 10014 10.so.0.1.0.14 98 * 1.2.4 13 10204 12.so.0.1.2.4 99 * 1.2.5beta1-2 13 10205 12.so.0.1.2.5beta1-2 100 * 1.0.15rc1-3 10 10015 10.so.0.1.0.15rc1-3 101 * 1.2.5rc1-3 13 10205 12.so.0.1.2.5rc1-3 102 * 1.0.15 10 10015 10.so.0.1.0.15 103 * 1.2.5 13 10205 12.so.0.1.2.5 104 * 1.2.6beta1-4 13 10206 12.so.0.1.2.6beta1-4 105 * 1.0.16 10 10016 10.so.0.1.0.16 106 * 1.2.6 13 10206 12.so.0.1.2.6 107 * 1.2.7beta1-2 13 10207 12.so.0.1.2.7beta1-2 108 * 1.0.17rc1 10 10017 12.so.0.1.0.17rc1 109 * 1.2.7rc1 13 10207 12.so.0.1.2.7rc1 110 * 1.0.17 10 10017 12.so.0.1.0.17 111 * 1.2.7 13 10207 12.so.0.1.2.7 112 * 1.2.8beta1-5 13 10208 12.so.0.1.2.8beta1-5 113 * 1.0.18rc1-5 10 10018 12.so.0.1.0.18rc1-5 114 * 1.2.8rc1-5 13 10208 12.so.0.1.2.8rc1-5 115 * 1.0.18 10 10018 12.so.0.1.0.18 116 * 1.2.8 13 10208 12.so.0.1.2.8 117 * 1.2.9beta1-3 13 10209 12.so.0.1.2.9beta1-3 118 * 1.2.9beta4-11 13 10209 12.so.0.9[.0] 119 * 1.2.9rc1 13 10209 12.so.0.9[.0] 120 * 1.2.9 13 10209 12.so.0.9[.0] 121 * 1.2.10beta1-7 13 10210 12.so.0.10[.0] 122 * 1.2.10rc1-2 13 10210 12.so.0.10[.0] 123 * 1.2.10 13 10210 12.so.0.10[.0] 124 * 1.4.0beta1-5 14 10400 14.so.0.0[.0] 125 * 1.2.11beta1-4 13 10211 12.so.0.11[.0] 126 * 1.4.0beta7-8 14 10400 14.so.0.0[.0] 127 * 1.2.11 13 10211 12.so.0.11[.0] 128 * 1.2.12 13 10212 12.so.0.12[.0] 129 * 1.4.0beta9-14 14 10400 14.so.0.0[.0] 130 * 1.2.13 13 10213 12.so.0.13[.0] 131 * 1.4.0beta15-36 14 10400 14.so.0.0[.0] 132 * 1.4.0beta37-87 14 10400 14.so.14.0[.0] 133 * 1.4.0rc01 14 10400 14.so.14.0[.0] 134 * 1.4.0beta88-109 14 10400 14.so.14.0[.0] 135 * 1.4.0rc02-08 14 10400 14.so.14.0[.0] 136 * 1.4.0 14 10400 14.so.14.0[.0] 137 * 1.4.1beta01-03 14 10401 14.so.14.1[.0] 138 * 1.4.1rc01 14 10401 14.so.14.1[.0] 139 * 1.4.1beta04-12 14 10401 14.so.14.1[.0] 140 * 1.4.1 14 10401 14.so.14.1[.0] 141 * 1.4.2 14 10402 14.so.14.2[.0] 142 * 1.4.3 14 10403 14.so.14.3[.0] 143 * 1.4.4 14 10404 14.so.14.4[.0] 144 * 1.5.0beta01-58 15 10500 15.so.15.0[.0] 145 * 1.5.0rc01-07 15 10500 15.so.15.0[.0] 146 * 1.5.0 15 10500 15.so.15.0[.0] 147 * 1.5.1beta01-11 15 10501 15.so.15.1[.0] 148 * 1.5.1rc01-02 15 10501 15.so.15.1[.0] 149 * 1.5.1 15 10501 15.so.15.1[.0] 150 * 1.5.2beta01-03 15 10502 15.so.15.2[.0] 151 * 1.5.2rc01-03 15 10502 15.so.15.2[.0] 152 * 1.5.2 15 10502 15.so.15.2[.0] 153 * 1.5.3beta01-10 15 10503 15.so.15.3[.0] 154 * 1.5.3rc01-02 15 10503 15.so.15.3[.0] 155 * 1.5.3beta11 15 10503 15.so.15.3[.0] 156 * 1.5.3 [omitted] 157 * 1.5.4beta01-08 15 10504 15.so.15.4[.0] 158 * 1.5.4rc01 15 10504 15.so.15.4[.0] 159 * 1.5.4 15 10504 15.so.15.4[.0] 160 * 1.5.5beta01-08 15 10505 15.so.15.5[.0] 161 * 1.5.5rc01 15 10505 15.so.15.5[.0] 162 * 1.5.5 15 10505 15.so.15.5[.0] 163 * 1.5.6beta01-07 15 10506 15.so.15.6[.0] 164 * 1.5.6rc01-03 15 10506 15.so.15.6[.0] 165 * 1.5.6 15 10506 15.so.15.6[.0] 166 * 1.5.7beta01-05 15 10507 15.so.15.7[.0] 167 * 1.5.7rc01-03 15 10507 15.so.15.7[.0] 168 * 1.5.7 15 10507 15.so.15.7[.0] 169 * 1.6.0beta01-40 16 10600 16.so.16.0[.0] 170 * 1.6.0rc01-08 16 10600 16.so.16.0[.0] 171 * 1.6.0 16 10600 16.so.16.0[.0] 172 * 1.6.1beta01-09 16 10601 16.so.16.1[.0] 173 * 1.6.1rc01 16 10601 16.so.16.1[.0] 174 * 1.6.1 16 10601 16.so.16.1[.0] 175 * 1.6.2beta01 16 10602 16.so.16.2[.0] 176 * 1.6.2rc01-06 16 10602 16.so.16.2[.0] 177 * 1.6.2 16 10602 16.so.16.2[.0] 178 * 1.6.3beta01-11 16 10603 16.so.16.3[.0] 179 * 1.6.3rc01 16 10603 16.so.16.3[.0] 180 * 1.6.3 16 10603 16.so.16.3[.0] 181 * 1.6.4beta01-02 16 10604 16.so.16.4[.0] 182 * 1.6.4rc01 16 10604 16.so.16.4[.0] 183 * 1.6.4 16 10604 16.so.16.4[.0] 184 * 1.6.5 16 10605 16.so.16.5[.0] 185 * 1.6.6 16 10606 16.so.16.6[.0] 186 * 1.6.7beta01-04 16 10607 16.so.16.7[.0] 187 * 1.6.7rc01-03 16 10607 16.so.16.7[.0] 188 * 1.6.7 16 10607 16.so.16.7[.0] 189 * 1.6.8beta01-02 16 10608 16.so.16.8[.0] 190 * 1.6.8rc01-02 16 10608 16.so.16.8[.0] 191 * 1.6.8 16 10608 16.so.16.8[.0] 192 * 1.6.9beta01-04 16 10609 16.so.16.9[.0] 193 * 1.6.9rc01-02 16 10609 16.so.16.9[.0] 194 * 1.6.9 16 10609 16.so.16.9[.0] 195 * 1.6.10beta01-03 16 10610 16.so.16.10[.0] 196 * 1.6.10rc01-03 16 10610 16.so.16.10[.0] 197 * 1.6.10 16 10610 16.so.16.10[.0] 198 * 1.6.11beta01-06 16 10611 16.so.16.11[.0] 199 * 1.6.11rc01-02 16 10611 16.so.16.11[.0] 200 * 1.6.11 16 10611 16.so.16.11[.0] 201 * 1.6.12rc01-03 16 10612 16.so.16.12[.0] 202 * 1.6.12 16 10612 16.so.16.12[.0] 203 * 204 * Henceforth the source version will match the shared-library major 205 * and minor numbers; the shared-library major version number will be 206 * used for changes in backward compatibility, as it is intended. The 207 * PNG_LIBPNG_VER macro, which is not used within libpng but is available 208 * for applications, is an unsigned integer of the form xyyzz corresponding 209 * to the source version x.y.z (leading zeros in y and z). Beta versions 210 * were given the previous public release number plus a letter, until 211 * version 1.0.6j; from then on they were given the upcoming public 212 * release number plus "betaNN" or "rcNN". 213 * 214 * Binary incompatibility exists only when applications make direct access 215 * to the info_ptr or png_ptr members through png.h, and the compiled 216 * application is loaded with a different version of the library. 217 * 218 * DLLNUM will change each time there are forward or backward changes 219 * in binary compatibility (e.g., when a new feature is added). 220 * 221 * See libpng-manual.txt or libpng.3 for more information. The PNG 222 * specification is available as a W3C Recommendation and as an ISO 223 * Specification, <http://www.w3.org/TR/2003/REC-PNG-20031110/ 224 */ 225 226 /* 227 * COPYRIGHT NOTICE, DISCLAIMER, and LICENSE: 228 * 229 * If you modify libpng you may insert additional notices immediately following 230 * this sentence. 231 * 232 * This code is released under the libpng license. 233 * 234 * libpng versions 1.2.6, August 15, 2004, through 1.6.12, June 12, 2014, are 235 * Copyright (c) 2004, 2006-2014 Glenn Randers-Pehrson, and are 236 * distributed according to the same disclaimer and license as libpng-1.2.5 237 * with the following individual added to the list of Contributing Authors: 238 * 239 * Cosmin Truta 240 * 241 * libpng versions 1.0.7, July 1, 2000, through 1.2.5, October 3, 2002, are 242 * Copyright (c) 2000-2002 Glenn Randers-Pehrson, and are 243 * distributed according to the same disclaimer and license as libpng-1.0.6 244 * with the following individuals added to the list of Contributing Authors: 245 * 246 * Simon-Pierre Cadieux 247 * Eric S. Raymond 248 * Gilles Vollant 249 * 250 * and with the following additions to the disclaimer: 251 * 252 * There is no warranty against interference with your enjoyment of the 253 * library or against infringement. There is no warranty that our 254 * efforts or the library will fulfill any of your particular purposes 255 * or needs. This library is provided with all faults, and the entire 256 * risk of satisfactory quality, performance, accuracy, and effort is with 257 * the user. 258 * 259 * libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are 260 * Copyright (c) 1998, 1999, 2000 Glenn Randers-Pehrson, and are 261 * distributed according to the same disclaimer and license as libpng-0.96, 262 * with the following individuals added to the list of Contributing Authors: 263 * 264 * Tom Lane 265 * Glenn Randers-Pehrson 266 * Willem van Schaik 267 * 268 * libpng versions 0.89, June 1996, through 0.96, May 1997, are 269 * Copyright (c) 1996, 1997 Andreas Dilger 270 * Distributed according to the same disclaimer and license as libpng-0.88, 271 * with the following individuals added to the list of Contributing Authors: 272 * 273 * John Bowler 274 * Kevin Bracey 275 * Sam Bushell 276 * Magnus Holmgren 277 * Greg Roelofs 278 * Tom Tanner 279 * 280 * libpng versions 0.5, May 1995, through 0.88, January 1996, are 281 * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. 282 * 283 * For the purposes of this copyright and license, "Contributing Authors" 284 * is defined as the following set of individuals: 285 * 286 * Andreas Dilger 287 * Dave Martindale 288 * Guy Eric Schalnat 289 * Paul Schmidt 290 * Tim Wegner 291 * 292 * The PNG Reference Library is supplied "AS IS". The Contributing Authors 293 * and Group 42, Inc. disclaim all warranties, expressed or implied, 294 * including, without limitation, the warranties of merchantability and of 295 * fitness for any purpose. The Contributing Authors and Group 42, Inc. 296 * assume no liability for direct, indirect, incidental, special, exemplary, 297 * or consequential damages, which may result from the use of the PNG 298 * Reference Library, even if advised of the possibility of such damage. 299 * 300 * Permission is hereby granted to use, copy, modify, and distribute this 301 * source code, or portions hereof, for any purpose, without fee, subject 302 * to the following restrictions: 303 * 304 * 1. The origin of this source code must not be misrepresented. 305 * 306 * 2. Altered versions must be plainly marked as such and must not 307 * be misrepresented as being the original source. 308 * 309 * 3. This Copyright notice may not be removed or altered from 310 * any source or altered source distribution. 311 * 312 * The Contributing Authors and Group 42, Inc. specifically permit, without 313 * fee, and encourage the use of this source code as a component to 314 * supporting the PNG file format in commercial products. If you use this 315 * source code in a product, acknowledgment is not required but would be 316 * appreciated. 317 */ 318 319 /* 320 * A "png_get_copyright" function is available, for convenient use in "about" 321 * boxes and the like: 322 * 323 * printf("%s", png_get_copyright(NULL)); 324 * 325 * Also, the PNG logo (in PNG format, of course) is supplied in the 326 * files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31). 327 */ 328 329 /* 330 * Libpng is OSI Certified Open Source Software. OSI Certified is a 331 * certification mark of the Open Source Initiative. 332 */ 333 334 /* 335 * The contributing authors would like to thank all those who helped 336 * with testing, bug fixes, and patience. This wouldn't have been 337 * possible without all of you. 338 * 339 * Thanks to Frank J. T. Wojcik for helping with the documentation. 340 */ 341 342 /* 343 * Y2K compliance in libpng: 344 * ========================= 345 * 346 * June 12, 2014 347 * 348 * Since the PNG Development group is an ad-hoc body, we can't make 349 * an official declaration. 350 * 351 * This is your unofficial assurance that libpng from version 0.71 and 352 * upward through 1.6.12 are Y2K compliant. It is my belief that 353 * earlier versions were also Y2K compliant. 354 * 355 * Libpng only has two year fields. One is a 2-byte unsigned integer 356 * that will hold years up to 65535. The other, which is deprecated, 357 * holds the date in text format, and will hold years up to 9999. 358 * 359 * The integer is 360 * "png_uint_16 year" in png_time_struct. 361 * 362 * The string is 363 * "char time_buffer[29]" in png_struct. This is no longer used 364 * in libpng-1.6.x and will be removed from libpng-1.7.0. 365 * 366 * There are seven time-related functions: 367 * png.c: png_convert_to_rfc_1123_buffer() in png.c 368 * (formerly png_convert_to_rfc_1123() prior to libpng-1.5.x and 369 * png_convert_to_rfc_1152() in error prior to libpng-0.98) 370 * png_convert_from_struct_tm() in pngwrite.c, called in pngwrite.c 371 * png_convert_from_time_t() in pngwrite.c 372 * png_get_tIME() in pngget.c 373 * png_handle_tIME() in pngrutil.c, called in pngread.c 374 * png_set_tIME() in pngset.c 375 * png_write_tIME() in pngwutil.c, called in pngwrite.c 376 * 377 * All handle dates properly in a Y2K environment. The 378 * png_convert_from_time_t() function calls gmtime() to convert from system 379 * clock time, which returns (year - 1900), which we properly convert to 380 * the full 4-digit year. There is a possibility that libpng applications 381 * are not passing 4-digit years into the png_convert_to_rfc_1123_buffer() 382 * function, or that they are incorrectly passing only a 2-digit year 383 * instead of "year - 1900" into the png_convert_from_struct_tm() function, 384 * but this is not under our control. The libpng documentation has always 385 * stated that it works with 4-digit years, and the APIs have been 386 * documented as such. 387 * 388 * The tIME chunk itself is also Y2K compliant. It uses a 2-byte unsigned 389 * integer to hold the year, and can hold years as large as 65535. 390 * 391 * zlib, upon which libpng depends, is also Y2K compliant. It contains 392 * no date-related code. 393 * 394 * Glenn Randers-Pehrson 395 * libpng maintainer 396 * PNG Development Group 397 */ 398 399 #ifndef PNG_H 400 #define PNG_H 401 402 /* This is not the place to learn how to use libpng. The file libpng-manual.txt 403 * describes how to use libpng, and the file example.c summarizes it 404 * with some code on which to build. This file is useful for looking 405 * at the actual function definitions and structure components. If that 406 * file has been stripped from your copy of libpng, you can find it at 407 * <http://www.libpng.org/pub/png/libpng-manual.txt> 408 * 409 * If you just need to read a PNG file and don't want to read the documentation 410 * skip to the end of this file and read the section entitled 'simplified API'. 411 */ 412 413 /* Version information for png.h - this should match the version in png.c */ 414 #define PNG_LIBPNG_VER_STRING "1.6.12" 415 #define PNG_HEADER_VERSION_STRING \ 416 " libpng version 1.6.12 - June 12, 2014\n" 417 418 #define PNG_LIBPNG_VER_SONUM 16 419 #define PNG_LIBPNG_VER_DLLNUM 16 420 421 /* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */ 422 #define PNG_LIBPNG_VER_MAJOR 1 423 #define PNG_LIBPNG_VER_MINOR 6 424 #define PNG_LIBPNG_VER_RELEASE 12 425 426 /* This should match the numeric part of the final component of 427 * PNG_LIBPNG_VER_STRING, omitting any leading zero: 428 */ 429 430 #define PNG_LIBPNG_VER_BUILD 0 431 432 /* Release Status */ 433 #define PNG_LIBPNG_BUILD_ALPHA 1 434 #define PNG_LIBPNG_BUILD_BETA 2 435 #define PNG_LIBPNG_BUILD_RC 3 436 #define PNG_LIBPNG_BUILD_STABLE 4 437 #define PNG_LIBPNG_BUILD_RELEASE_STATUS_MASK 7 438 439 /* Release-Specific Flags */ 440 #define PNG_LIBPNG_BUILD_PATCH 8 /* Can be OR'ed with 441 PNG_LIBPNG_BUILD_STABLE only */ 442 #define PNG_LIBPNG_BUILD_PRIVATE 16 /* Cannot be OR'ed with 443 PNG_LIBPNG_BUILD_SPECIAL */ 444 #define PNG_LIBPNG_BUILD_SPECIAL 32 /* Cannot be OR'ed with 445 PNG_LIBPNG_BUILD_PRIVATE */ 446 447 #define PNG_LIBPNG_BUILD_BASE_TYPE PNG_LIBPNG_BUILD_STABLE 448 449 /* Careful here. At one time, Guy wanted to use 082, but that would be octal. 450 * We must not include leading zeros. 451 * Versions 0.7 through 1.0.0 were in the range 0 to 100 here (only 452 * version 1.0.0 was mis-numbered 100 instead of 10000). From 453 * version 1.0.1 it's xxyyzz, where x=major, y=minor, z=release 454 */ 455 #define PNG_LIBPNG_VER 10612 /* 1.6.12 */ 456 457 /* Library configuration: these options cannot be changed after 458 * the library has been built. 459 */ 460 #ifndef PNGLCONF_H 461 /* If pnglibconf.h is missing, you can 462 * copy scripts/pnglibconf.h.prebuilt to pnglibconf.h 463 */ 464 # include "pnglibconf.h" 465 #endif 466 467 #ifndef PNG_VERSION_INFO_ONLY 468 /* Machine specific configuration. */ 469 # include "pngconf.h" 470 #endif 471 472 /* 473 * Added at libpng-1.2.8 474 * 475 * Ref MSDN: Private as priority over Special 476 * VS_FF_PRIVATEBUILD File *was not* built using standard release 477 * procedures. If this value is given, the StringFileInfo block must 478 * contain a PrivateBuild string. 479 * 480 * VS_FF_SPECIALBUILD File *was* built by the original company using 481 * standard release procedures but is a variation of the standard 482 * file of the same version number. If this value is given, the 483 * StringFileInfo block must contain a SpecialBuild string. 484 */ 485 486 #ifdef PNG_USER_PRIVATEBUILD /* From pnglibconf.h */ 487 # define PNG_LIBPNG_BUILD_TYPE \ 488 (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_PRIVATE) 489 #else 490 # ifdef PNG_LIBPNG_SPECIALBUILD 491 # define PNG_LIBPNG_BUILD_TYPE \ 492 (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_SPECIAL) 493 # else 494 # define PNG_LIBPNG_BUILD_TYPE (PNG_LIBPNG_BUILD_BASE_TYPE) 495 # endif 496 #endif 497 498 #ifndef PNG_VERSION_INFO_ONLY 499 500 /* Inhibit C++ name-mangling for libpng functions but not for system calls. */ 501 #ifdef __cplusplus 502 extern "C" { 503 #endif /* __cplusplus */ 504 505 /* Version information for C files, stored in png.c. This had better match 506 * the version above. 507 */ 508 #define png_libpng_ver png_get_header_ver(NULL) 509 510 /* This file is arranged in several sections: 511 * 512 * 1. Any configuration options that can be specified by for the application 513 * code when it is built. (Build time configuration is in pnglibconf.h) 514 * 2. Type definitions (base types are defined in pngconf.h), structure 515 * definitions. 516 * 3. Exported library functions. 517 * 4. Simplified API. 518 * 519 * The library source code has additional files (principally pngpriv.h) that 520 * allow configuration of the library. 521 */ 522 /* Section 1: run time configuration 523 * See pnglibconf.h for build time configuration 524 * 525 * Run time configuration allows the application to choose between 526 * implementations of certain arithmetic APIs. The default is set 527 * at build time and recorded in pnglibconf.h, but it is safe to 528 * override these (and only these) settings. Note that this won't 529 * change what the library does, only application code, and the 530 * settings can (and probably should) be made on a per-file basis 531 * by setting the #defines before including png.h 532 * 533 * Use macros to read integers from PNG data or use the exported 534 * functions? 535 * PNG_USE_READ_MACROS: use the macros (see below) Note that 536 * the macros evaluate their argument multiple times. 537 * PNG_NO_USE_READ_MACROS: call the relevant library function. 538 * 539 * Use the alternative algorithm for compositing alpha samples that 540 * does not use division? 541 * PNG_READ_COMPOSITE_NODIV_SUPPORTED: use the 'no division' 542 * algorithm. 543 * PNG_NO_READ_COMPOSITE_NODIV: use the 'division' algorithm. 544 * 545 * How to handle benign errors if PNG_ALLOW_BENIGN_ERRORS is 546 * false? 547 * PNG_ALLOW_BENIGN_ERRORS: map calls to the benign error 548 * APIs to png_warning. 549 * Otherwise the calls are mapped to png_error. 550 */ 551 552 /* Section 2: type definitions, including structures and compile time 553 * constants. 554 * See pngconf.h for base types that vary by machine/system 555 */ 556 557 /* This triggers a compiler error in png.c, if png.c and png.h 558 * do not agree upon the version number. 559 */ 560 typedef char* png_libpng_version_1_6_12; 561 562 /* Basic control structions. Read libpng-manual.txt or libpng.3 for more info. 563 * 564 * png_struct is the cache of information used while reading or writing a single 565 * PNG file. One of these is always required, although the simplified API 566 * (below) hides the creation and destruction of it. 567 */ 568 typedef struct png_struct_def png_struct; 569 typedef const png_struct * png_const_structp; 570 typedef png_struct * png_structp; 571 typedef png_struct * * png_structpp; 572 573 /* png_info contains information read from or to be written to a PNG file. One 574 * or more of these must exist while reading or creating a PNG file. The 575 * information is not used by libpng during read but is used to control what 576 * gets written when a PNG file is created. "png_get_" function calls read 577 * information during read and "png_set_" functions calls write information 578 * when creating a PNG. 579 * been moved into a separate header file that is not accessible to 580 * applications. Read libpng-manual.txt or libpng.3 for more info. 581 */ 582 typedef struct png_info_def png_info; 583 typedef png_info * png_infop; 584 typedef const png_info * png_const_infop; 585 typedef png_info * * png_infopp; 586 587 /* Types with names ending 'p' are pointer types. The corresponding types with 588 * names ending 'rp' are identical pointer types except that the pointer is 589 * marked 'restrict', which means that it is the only pointer to the object 590 * passed to the function. Applications should not use the 'restrict' types; 591 * it is always valid to pass 'p' to a pointer with a function argument of the 592 * corresponding 'rp' type. Different compilers have different rules with 593 * regard to type matching in the presence of 'restrict'. For backward 594 * compatibility libpng callbacks never have 'restrict' in their parameters and, 595 * consequentially, writing portable application code is extremely difficult if 596 * an attempt is made to use 'restrict'. 597 */ 598 typedef png_struct * PNG_RESTRICT png_structrp; 599 typedef const png_struct * PNG_RESTRICT png_const_structrp; 600 typedef png_info * PNG_RESTRICT png_inforp; 601 typedef const png_info * PNG_RESTRICT png_const_inforp; 602 603 /* Three color definitions. The order of the red, green, and blue, (and the 604 * exact size) is not important, although the size of the fields need to 605 * be png_byte or png_uint_16 (as defined below). 606 */ 607 typedef struct png_color_struct 608 { 609 png_byte red; 610 png_byte green; 611 png_byte blue; 612 } png_color; 613 typedef png_color * png_colorp; 614 typedef const png_color * png_const_colorp; 615 typedef png_color * * png_colorpp; 616 617 typedef struct png_color_16_struct 618 { 619 png_byte index; /* used for palette files */ 620 png_uint_16 red; /* for use in red green blue files */ 621 png_uint_16 green; 622 png_uint_16 blue; 623 png_uint_16 gray; /* for use in grayscale files */ 624 } png_color_16; 625 typedef png_color_16 * png_color_16p; 626 typedef const png_color_16 * png_const_color_16p; 627 typedef png_color_16 * * png_color_16pp; 628 629 typedef struct png_color_8_struct 630 { 631 png_byte red; /* for use in red green blue files */ 632 png_byte green; 633 png_byte blue; 634 png_byte gray; /* for use in grayscale files */ 635 png_byte alpha; /* for alpha channel files */ 636 } png_color_8; 637 typedef png_color_8 * png_color_8p; 638 typedef const png_color_8 * png_const_color_8p; 639 typedef png_color_8 * * png_color_8pp; 640 641 /* 642 * The following two structures are used for the in-core representation 643 * of sPLT chunks. 644 */ 645 typedef struct png_sPLT_entry_struct 646 { 647 png_uint_16 red; 648 png_uint_16 green; 649 png_uint_16 blue; 650 png_uint_16 alpha; 651 png_uint_16 frequency; 652 } png_sPLT_entry; 653 typedef png_sPLT_entry * png_sPLT_entryp; 654 typedef const png_sPLT_entry * png_const_sPLT_entryp; 655 typedef png_sPLT_entry * * png_sPLT_entrypp; 656 657 /* When the depth of the sPLT palette is 8 bits, the color and alpha samples 658 * occupy the LSB of their respective members, and the MSB of each member 659 * is zero-filled. The frequency member always occupies the full 16 bits. 660 */ 661 662 typedef struct png_sPLT_struct 663 { 664 png_charp name; /* palette name */ 665 png_byte depth; /* depth of palette samples */ 666 png_sPLT_entryp entries; /* palette entries */ 667 png_int_32 nentries; /* number of palette entries */ 668 } png_sPLT_t; 669 typedef png_sPLT_t * png_sPLT_tp; 670 typedef const png_sPLT_t * png_const_sPLT_tp; 671 typedef png_sPLT_t * * png_sPLT_tpp; 672 673 #ifdef PNG_TEXT_SUPPORTED 674 /* png_text holds the contents of a text/ztxt/itxt chunk in a PNG file, 675 * and whether that contents is compressed or not. The "key" field 676 * points to a regular zero-terminated C string. The "text" fields can be a 677 * regular C string, an empty string, or a NULL pointer. 678 * However, the structure returned by png_get_text() will always contain 679 * the "text" field as a regular zero-terminated C string (possibly 680 * empty), never a NULL pointer, so it can be safely used in printf() and 681 * other string-handling functions. Note that the "itxt_length", "lang", and 682 * "lang_key" members of the structure only exist when the library is built 683 * with iTXt chunk support. Prior to libpng-1.4.0 the library was built by 684 * default without iTXt support. Also note that when iTXt *is* supported, 685 * the "lang" and "lang_key" fields contain NULL pointers when the 686 * "compression" field contains * PNG_TEXT_COMPRESSION_NONE or 687 * PNG_TEXT_COMPRESSION_zTXt. Note that the "compression value" is not the 688 * same as what appears in the PNG tEXt/zTXt/iTXt chunk's "compression flag" 689 * which is always 0 or 1, or its "compression method" which is always 0. 690 */ 691 typedef struct png_text_struct 692 { 693 int compression; /* compression value: 694 -1: tEXt, none 695 0: zTXt, deflate 696 1: iTXt, none 697 2: iTXt, deflate */ 698 png_charp key; /* keyword, 1-79 character description of "text" */ 699 png_charp text; /* comment, may be an empty string (ie "") 700 or a NULL pointer */ 701 png_size_t text_length; /* length of the text string */ 702 png_size_t itxt_length; /* length of the itxt string */ 703 png_charp lang; /* language code, 0-79 characters 704 or a NULL pointer */ 705 png_charp lang_key; /* keyword translated UTF-8 string, 0 or more 706 chars or a NULL pointer */ 707 } png_text; 708 typedef png_text * png_textp; 709 typedef const png_text * png_const_textp; 710 typedef png_text * * png_textpp; 711 #endif 712 713 /* Supported compression types for text in PNG files (tEXt, and zTXt). 714 * The values of the PNG_TEXT_COMPRESSION_ defines should NOT be changed. */ 715 #define PNG_TEXT_COMPRESSION_NONE_WR -3 716 #define PNG_TEXT_COMPRESSION_zTXt_WR -2 717 #define PNG_TEXT_COMPRESSION_NONE -1 718 #define PNG_TEXT_COMPRESSION_zTXt 0 719 #define PNG_ITXT_COMPRESSION_NONE 1 720 #define PNG_ITXT_COMPRESSION_zTXt 2 721 #define PNG_TEXT_COMPRESSION_LAST 3 /* Not a valid value */ 722 723 /* png_time is a way to hold the time in an machine independent way. 724 * Two conversions are provided, both from time_t and struct tm. There 725 * is no portable way to convert to either of these structures, as far 726 * as I know. If you know of a portable way, send it to me. As a side 727 * note - PNG has always been Year 2000 compliant! 728 */ 729 typedef struct png_time_struct 730 { 731 png_uint_16 year; /* full year, as in, 1995 */ 732 png_byte month; /* month of year, 1 - 12 */ 733 png_byte day; /* day of month, 1 - 31 */ 734 png_byte hour; /* hour of day, 0 - 23 */ 735 png_byte minute; /* minute of hour, 0 - 59 */ 736 png_byte second; /* second of minute, 0 - 60 (for leap seconds) */ 737 } png_time; 738 typedef png_time * png_timep; 739 typedef const png_time * png_const_timep; 740 typedef png_time * * png_timepp; 741 742 #if defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED) ||\ 743 defined(PNG_USER_CHUNKS_SUPPORTED) 744 /* png_unknown_chunk is a structure to hold queued chunks for which there is 745 * no specific support. The idea is that we can use this to queue 746 * up private chunks for output even though the library doesn't actually 747 * know about their semantics. 748 * 749 * The data in the structure is set by libpng on read and used on write. 750 */ 751 typedef struct png_unknown_chunk_t 752 { 753 png_byte name[5]; /* Textual chunk name with '\0' terminator */ 754 png_byte *data; /* Data, should not be modified on read! */ 755 png_size_t size; 756 757 /* On write 'location' must be set using the flag values listed below. 758 * Notice that on read it is set by libpng however the values stored have 759 * more bits set than are listed below. Always treat the value as a 760 * bitmask. On write set only one bit - setting multiple bits may cause the 761 * chunk to be written in multiple places. 762 */ 763 png_byte location; /* mode of operation at read time */ 764 } 765 png_unknown_chunk; 766 767 typedef png_unknown_chunk * png_unknown_chunkp; 768 typedef const png_unknown_chunk * png_const_unknown_chunkp; 769 typedef png_unknown_chunk * * png_unknown_chunkpp; 770 #endif 771 772 /* Flag values for the unknown chunk location byte. */ 773 #define PNG_HAVE_IHDR 0x01 774 #define PNG_HAVE_PLTE 0x02 775 #define PNG_AFTER_IDAT 0x08 776 777 /* Maximum positive integer used in PNG is (2^31)-1 */ 778 #define PNG_UINT_31_MAX ((png_uint_32)0x7fffffffL) 779 #define PNG_UINT_32_MAX ((png_uint_32)(-1)) 780 #define PNG_SIZE_MAX ((png_size_t)(-1)) 781 782 /* These are constants for fixed point values encoded in the 783 * PNG specification manner (x100000) 784 */ 785 #define PNG_FP_1 100000 786 #define PNG_FP_HALF 50000 787 #define PNG_FP_MAX ((png_fixed_point)0x7fffffffL) 788 #define PNG_FP_MIN (-PNG_FP_MAX) 789 790 /* These describe the color_type field in png_info. */ 791 /* color type masks */ 792 #define PNG_COLOR_MASK_PALETTE 1 793 #define PNG_COLOR_MASK_COLOR 2 794 #define PNG_COLOR_MASK_ALPHA 4 795 796 /* color types. Note that not all combinations are legal */ 797 #define PNG_COLOR_TYPE_GRAY 0 798 #define PNG_COLOR_TYPE_PALETTE (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE) 799 #define PNG_COLOR_TYPE_RGB (PNG_COLOR_MASK_COLOR) 800 #define PNG_COLOR_TYPE_RGB_ALPHA (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_ALPHA) 801 #define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA) 802 /* aliases */ 803 #define PNG_COLOR_TYPE_RGBA PNG_COLOR_TYPE_RGB_ALPHA 804 #define PNG_COLOR_TYPE_GA PNG_COLOR_TYPE_GRAY_ALPHA 805 806 /* This is for compression type. PNG 1.0-1.2 only define the single type. */ 807 #define PNG_COMPRESSION_TYPE_BASE 0 /* Deflate method 8, 32K window */ 808 #define PNG_COMPRESSION_TYPE_DEFAULT PNG_COMPRESSION_TYPE_BASE 809 810 /* This is for filter type. PNG 1.0-1.2 only define the single type. */ 811 #define PNG_FILTER_TYPE_BASE 0 /* Single row per-byte filtering */ 812 #define PNG_INTRAPIXEL_DIFFERENCING 64 /* Used only in MNG datastreams */ 813 #define PNG_FILTER_TYPE_DEFAULT PNG_FILTER_TYPE_BASE 814 815 /* These are for the interlacing type. These values should NOT be changed. */ 816 #define PNG_INTERLACE_NONE 0 /* Non-interlaced image */ 817 #define PNG_INTERLACE_ADAM7 1 /* Adam7 interlacing */ 818 #define PNG_INTERLACE_LAST 2 /* Not a valid value */ 819 820 /* These are for the oFFs chunk. These values should NOT be changed. */ 821 #define PNG_OFFSET_PIXEL 0 /* Offset in pixels */ 822 #define PNG_OFFSET_MICROMETER 1 /* Offset in micrometers (1/10^6 meter) */ 823 #define PNG_OFFSET_LAST 2 /* Not a valid value */ 824 825 /* These are for the pCAL chunk. These values should NOT be changed. */ 826 #define PNG_EQUATION_LINEAR 0 /* Linear transformation */ 827 #define PNG_EQUATION_BASE_E 1 /* Exponential base e transform */ 828 #define PNG_EQUATION_ARBITRARY 2 /* Arbitrary base exponential transform */ 829 #define PNG_EQUATION_HYPERBOLIC 3 /* Hyperbolic sine transformation */ 830 #define PNG_EQUATION_LAST 4 /* Not a valid value */ 831 832 /* These are for the sCAL chunk. These values should NOT be changed. */ 833 #define PNG_SCALE_UNKNOWN 0 /* unknown unit (image scale) */ 834 #define PNG_SCALE_METER 1 /* meters per pixel */ 835 #define PNG_SCALE_RADIAN 2 /* radians per pixel */ 836 #define PNG_SCALE_LAST 3 /* Not a valid value */ 837 838 /* These are for the pHYs chunk. These values should NOT be changed. */ 839 #define PNG_RESOLUTION_UNKNOWN 0 /* pixels/unknown unit (aspect ratio) */ 840 #define PNG_RESOLUTION_METER 1 /* pixels/meter */ 841 #define PNG_RESOLUTION_LAST 2 /* Not a valid value */ 842 843 /* These are for the sRGB chunk. These values should NOT be changed. */ 844 #define PNG_sRGB_INTENT_PERCEPTUAL 0 845 #define PNG_sRGB_INTENT_RELATIVE 1 846 #define PNG_sRGB_INTENT_SATURATION 2 847 #define PNG_sRGB_INTENT_ABSOLUTE 3 848 #define PNG_sRGB_INTENT_LAST 4 /* Not a valid value */ 849 850 /* This is for text chunks */ 851 #define PNG_KEYWORD_MAX_LENGTH 79 852 853 /* Maximum number of entries in PLTE/sPLT/tRNS arrays */ 854 #define PNG_MAX_PALETTE_LENGTH 256 855 856 /* These determine if an ancillary chunk's data has been successfully read 857 * from the PNG header, or if the application has filled in the corresponding 858 * data in the info_struct to be written into the output file. The values 859 * of the PNG_INFO_<chunk> defines should NOT be changed. 860 */ 861 #define PNG_INFO_gAMA 0x0001 862 #define PNG_INFO_sBIT 0x0002 863 #define PNG_INFO_cHRM 0x0004 864 #define PNG_INFO_PLTE 0x0008 865 #define PNG_INFO_tRNS 0x0010 866 #define PNG_INFO_bKGD 0x0020 867 #define PNG_INFO_hIST 0x0040 868 #define PNG_INFO_pHYs 0x0080 869 #define PNG_INFO_oFFs 0x0100 870 #define PNG_INFO_tIME 0x0200 871 #define PNG_INFO_pCAL 0x0400 872 #define PNG_INFO_sRGB 0x0800 /* GR-P, 0.96a */ 873 #define PNG_INFO_iCCP 0x1000 /* ESR, 1.0.6 */ 874 #define PNG_INFO_sPLT 0x2000 /* ESR, 1.0.6 */ 875 #define PNG_INFO_sCAL 0x4000 /* ESR, 1.0.6 */ 876 #define PNG_INFO_IDAT 0x8000 /* ESR, 1.0.6 */ 877 878 /* This is used for the transformation routines, as some of them 879 * change these values for the row. It also should enable using 880 * the routines for other purposes. 881 */ 882 typedef struct png_row_info_struct 883 { 884 png_uint_32 width; /* width of row */ 885 png_size_t rowbytes; /* number of bytes in row */ 886 png_byte color_type; /* color type of row */ 887 png_byte bit_depth; /* bit depth of row */ 888 png_byte channels; /* number of channels (1, 2, 3, or 4) */ 889 png_byte pixel_depth; /* bits per pixel (depth * channels) */ 890 } png_row_info; 891 892 typedef png_row_info * png_row_infop; 893 typedef png_row_info * * png_row_infopp; 894 895 /* These are the function types for the I/O functions and for the functions 896 * that allow the user to override the default I/O functions with his or her 897 * own. The png_error_ptr type should match that of user-supplied warning 898 * and error functions, while the png_rw_ptr type should match that of the 899 * user read/write data functions. Note that the 'write' function must not 900 * modify the buffer it is passed. The 'read' function, on the other hand, is 901 * expected to return the read data in the buffer. 902 */ 903 typedef PNG_CALLBACK(void, *png_error_ptr, (png_structp, png_const_charp)); 904 typedef PNG_CALLBACK(void, *png_rw_ptr, (png_structp, png_bytep, png_size_t)); 905 typedef PNG_CALLBACK(void, *png_flush_ptr, (png_structp)); 906 typedef PNG_CALLBACK(void, *png_read_status_ptr, (png_structp, png_uint_32, 907 int)); 908 typedef PNG_CALLBACK(void, *png_write_status_ptr, (png_structp, png_uint_32, 909 int)); 910 911 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED 912 typedef PNG_CALLBACK(void, *png_progressive_info_ptr, (png_structp, png_infop)); 913 typedef PNG_CALLBACK(void, *png_progressive_end_ptr, (png_structp, png_infop)); 914 915 /* The following callback receives png_uint_32 row_number, int pass for the 916 * png_bytep data of the row. When transforming an interlaced image the 917 * row number is the row number within the sub-image of the interlace pass, so 918 * the value will increase to the height of the sub-image (not the full image) 919 * then reset to 0 for the next pass. 920 * 921 * Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to 922 * find the output pixel (x,y) given an interlaced sub-image pixel 923 * (row,col,pass). (See below for these macros.) 924 */ 925 typedef PNG_CALLBACK(void, *png_progressive_row_ptr, (png_structp, png_bytep, 926 png_uint_32, int)); 927 #endif 928 929 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \ 930 defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) 931 typedef PNG_CALLBACK(void, *png_user_transform_ptr, (png_structp, png_row_infop, 932 png_bytep)); 933 #endif 934 935 #ifdef PNG_USER_CHUNKS_SUPPORTED 936 typedef PNG_CALLBACK(int, *png_user_chunk_ptr, (png_structp, 937 png_unknown_chunkp)); 938 #endif 939 #ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED 940 /* not used anywhere */ 941 /* typedef PNG_CALLBACK(void, *png_unknown_chunk_ptr, (png_structp)); */ 942 #endif 943 944 #ifdef PNG_SETJMP_SUPPORTED 945 /* This must match the function definition in <setjmp.h>, and the application 946 * must include this before png.h to obtain the definition of jmp_buf. The 947 * function is required to be PNG_NORETURN, but this is not checked. If the 948 * function does return the application will crash via an abort() or similar 949 * system level call. 950 * 951 * If you get a warning here while building the library you may need to make 952 * changes to ensure that pnglibconf.h records the calling convention used by 953 * your compiler. This may be very difficult - try using a different compiler 954 * to build the library! 955 */ 956 PNG_FUNCTION(void, (PNGCAPI *png_longjmp_ptr), PNGARG((jmp_buf, int)), typedef); 957 #endif 958 959 /* Transform masks for the high-level interface */ 960 #define PNG_TRANSFORM_IDENTITY 0x0000 /* read and write */ 961 #define PNG_TRANSFORM_STRIP_16 0x0001 /* read only */ 962 #define PNG_TRANSFORM_STRIP_ALPHA 0x0002 /* read only */ 963 #define PNG_TRANSFORM_PACKING 0x0004 /* read and write */ 964 #define PNG_TRANSFORM_PACKSWAP 0x0008 /* read and write */ 965 #define PNG_TRANSFORM_EXPAND 0x0010 /* read only */ 966 #define PNG_TRANSFORM_INVERT_MONO 0x0020 /* read and write */ 967 #define PNG_TRANSFORM_SHIFT 0x0040 /* read and write */ 968 #define PNG_TRANSFORM_BGR 0x0080 /* read and write */ 969 #define PNG_TRANSFORM_SWAP_ALPHA 0x0100 /* read and write */ 970 #define PNG_TRANSFORM_SWAP_ENDIAN 0x0200 /* read and write */ 971 #define PNG_TRANSFORM_INVERT_ALPHA 0x0400 /* read and write */ 972 #define PNG_TRANSFORM_STRIP_FILLER 0x0800 /* write only */ 973 /* Added to libpng-1.2.34 */ 974 #define PNG_TRANSFORM_STRIP_FILLER_BEFORE PNG_TRANSFORM_STRIP_FILLER 975 #define PNG_TRANSFORM_STRIP_FILLER_AFTER 0x1000 /* write only */ 976 /* Added to libpng-1.4.0 */ 977 #define PNG_TRANSFORM_GRAY_TO_RGB 0x2000 /* read only */ 978 /* Added to libpng-1.5.4 */ 979 #define PNG_TRANSFORM_EXPAND_16 0x4000 /* read only */ 980 #define PNG_TRANSFORM_SCALE_16 0x8000 /* read only */ 981 982 /* Flags for MNG supported features */ 983 #define PNG_FLAG_MNG_EMPTY_PLTE 0x01 984 #define PNG_FLAG_MNG_FILTER_64 0x04 985 #define PNG_ALL_MNG_FEATURES 0x05 986 987 /* NOTE: prior to 1.5 these functions had no 'API' style declaration, 988 * this allowed the zlib default functions to be used on Windows 989 * platforms. In 1.5 the zlib default malloc (which just calls malloc and 990 * ignores the first argument) should be completely compatible with the 991 * following. 992 */ 993 typedef PNG_CALLBACK(png_voidp, *png_malloc_ptr, (png_structp, 994 png_alloc_size_t)); 995 typedef PNG_CALLBACK(void, *png_free_ptr, (png_structp, png_voidp)); 996 997 /* Section 3: exported functions 998 * Here are the function definitions most commonly used. This is not 999 * the place to find out how to use libpng. See libpng-manual.txt for the 1000 * full explanation, see example.c for the summary. This just provides 1001 * a simple one line description of the use of each function. 1002 * 1003 * The PNG_EXPORT() and PNG_EXPORTA() macros used below are defined in 1004 * pngconf.h and in the *.dfn files in the scripts directory. 1005 * 1006 * PNG_EXPORT(ordinal, type, name, (args)); 1007 * 1008 * ordinal: ordinal that is used while building 1009 * *.def files. The ordinal value is only 1010 * relevant when preprocessing png.h with 1011 * the *.dfn files for building symbol table 1012 * entries, and are removed by pngconf.h. 1013 * type: return type of the function 1014 * name: function name 1015 * args: function arguments, with types 1016 * 1017 * When we wish to append attributes to a function prototype we use 1018 * the PNG_EXPORTA() macro instead. 1019 * 1020 * PNG_EXPORTA(ordinal, type, name, (args), attributes); 1021 * 1022 * ordinal, type, name, and args: same as in PNG_EXPORT(). 1023 * attributes: function attributes 1024 */ 1025 1026 /* Returns the version number of the library */ 1027 PNG_EXPORT(1, png_uint_32, png_access_version_number, (void)); 1028 1029 /* Tell lib we have already handled the first <num_bytes> magic bytes. 1030 * Handling more than 8 bytes from the beginning of the file is an error. 1031 */ 1032 PNG_EXPORT(2, void, png_set_sig_bytes, (png_structrp png_ptr, int num_bytes)); 1033 1034 /* Check sig[start] through sig[start + num_to_check - 1] to see if it's a 1035 * PNG file. Returns zero if the supplied bytes match the 8-byte PNG 1036 * signature, and non-zero otherwise. Having num_to_check == 0 or 1037 * start > 7 will always fail (ie return non-zero). 1038 */ 1039 PNG_EXPORT(3, int, png_sig_cmp, (png_const_bytep sig, png_size_t start, 1040 png_size_t num_to_check)); 1041 1042 /* Simple signature checking function. This is the same as calling 1043 * png_check_sig(sig, n) := !png_sig_cmp(sig, 0, n). 1044 */ 1045 #define png_check_sig(sig, n) !png_sig_cmp((sig), 0, (n)) 1046 1047 /* Allocate and initialize png_ptr struct for reading, and any other memory. */ 1048 PNG_EXPORTA(4, png_structp, png_create_read_struct, 1049 (png_const_charp user_png_ver, png_voidp error_ptr, 1050 png_error_ptr error_fn, png_error_ptr warn_fn), 1051 PNG_ALLOCATED); 1052 1053 /* Allocate and initialize png_ptr struct for writing, and any other memory */ 1054 PNG_EXPORTA(5, png_structp, png_create_write_struct, 1055 (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn, 1056 png_error_ptr warn_fn), 1057 PNG_ALLOCATED); 1058 1059 PNG_EXPORT(6, png_size_t, png_get_compression_buffer_size, 1060 (png_const_structrp png_ptr)); 1061 1062 PNG_EXPORT(7, void, png_set_compression_buffer_size, (png_structrp png_ptr, 1063 png_size_t size)); 1064 1065 /* Moved from pngconf.h in 1.4.0 and modified to ensure setjmp/longjmp 1066 * match up. 1067 */ 1068 #ifdef PNG_SETJMP_SUPPORTED 1069 /* This function returns the jmp_buf built in to *png_ptr. It must be 1070 * supplied with an appropriate 'longjmp' function to use on that jmp_buf 1071 * unless the default error function is overridden in which case NULL is 1072 * acceptable. The size of the jmp_buf is checked against the actual size 1073 * allocated by the library - the call will return NULL on a mismatch 1074 * indicating an ABI mismatch. 1075 */ 1076 PNG_EXPORT(8, jmp_buf*, png_set_longjmp_fn, (png_structrp png_ptr, 1077 png_longjmp_ptr longjmp_fn, size_t jmp_buf_size)); 1078 # define png_jmpbuf(png_ptr) \ 1079 (*png_set_longjmp_fn((png_ptr), longjmp, (sizeof (jmp_buf)))) 1080 #else 1081 # define png_jmpbuf(png_ptr) \ 1082 (LIBPNG_WAS_COMPILED_WITH__PNG_NO_SETJMP) 1083 #endif 1084 /* This function should be used by libpng applications in place of 1085 * longjmp(png_ptr->jmpbuf, val). If longjmp_fn() has been set, it 1086 * will use it; otherwise it will call PNG_ABORT(). This function was 1087 * added in libpng-1.5.0. 1088 */ 1089 PNG_EXPORTA(9, void, png_longjmp, (png_const_structrp png_ptr, int val), 1090 PNG_NORETURN); 1091 1092 #ifdef PNG_READ_SUPPORTED 1093 /* Reset the compression stream */ 1094 PNG_EXPORTA(10, int, png_reset_zstream, (png_structrp png_ptr), PNG_DEPRECATED); 1095 #endif 1096 1097 /* New functions added in libpng-1.0.2 (not enabled by default until 1.2.0) */ 1098 #ifdef PNG_USER_MEM_SUPPORTED 1099 PNG_EXPORTA(11, png_structp, png_create_read_struct_2, 1100 (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn, 1101 png_error_ptr warn_fn, 1102 png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn), 1103 PNG_ALLOCATED); 1104 PNG_EXPORTA(12, png_structp, png_create_write_struct_2, 1105 (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn, 1106 png_error_ptr warn_fn, 1107 png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn), 1108 PNG_ALLOCATED); 1109 #endif 1110 1111 /* Write the PNG file signature. */ 1112 PNG_EXPORT(13, void, png_write_sig, (png_structrp png_ptr)); 1113 1114 /* Write a PNG chunk - size, type, (optional) data, CRC. */ 1115 PNG_EXPORT(14, void, png_write_chunk, (png_structrp png_ptr, png_const_bytep 1116 chunk_name, png_const_bytep data, png_size_t length)); 1117 1118 /* Write the start of a PNG chunk - length and chunk name. */ 1119 PNG_EXPORT(15, void, png_write_chunk_start, (png_structrp png_ptr, 1120 png_const_bytep chunk_name, png_uint_32 length)); 1121 1122 /* Write the data of a PNG chunk started with png_write_chunk_start(). */ 1123 PNG_EXPORT(16, void, png_write_chunk_data, (png_structrp png_ptr, 1124 png_const_bytep data, png_size_t length)); 1125 1126 /* Finish a chunk started with png_write_chunk_start() (includes CRC). */ 1127 PNG_EXPORT(17, void, png_write_chunk_end, (png_structrp png_ptr)); 1128 1129 /* Allocate and initialize the info structure */ 1130 PNG_EXPORTA(18, png_infop, png_create_info_struct, (png_const_structrp png_ptr), 1131 PNG_ALLOCATED); 1132 1133 /* DEPRECATED: this function allowed init structures to be created using the 1134 * default allocation method (typically malloc). Use is deprecated in 1.6.0 and 1135 * the API will be removed in the future. 1136 */ 1137 PNG_EXPORTA(19, void, png_info_init_3, (png_infopp info_ptr, 1138 png_size_t png_info_struct_size), PNG_DEPRECATED); 1139 1140 /* Writes all the PNG information before the image. */ 1141 PNG_EXPORT(20, void, png_write_info_before_PLTE, 1142 (png_structrp png_ptr, png_const_inforp info_ptr)); 1143 PNG_EXPORT(21, void, png_write_info, 1144 (png_structrp png_ptr, png_const_inforp info_ptr)); 1145 1146 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED 1147 /* Read the information before the actual image data. */ 1148 PNG_EXPORT(22, void, png_read_info, 1149 (png_structrp png_ptr, png_inforp info_ptr)); 1150 #endif 1151 1152 #ifdef PNG_TIME_RFC1123_SUPPORTED 1153 /* Convert to a US string format: there is no localization support in this 1154 * routine. The original implementation used a 29 character buffer in 1155 * png_struct, this will be removed in future versions. 1156 */ 1157 #if PNG_LIBPNG_VER < 10700 1158 /* To do: remove this from libpng17 (and from libpng17/png.c and pngstruct.h) */ 1159 PNG_EXPORTA(23, png_const_charp, png_convert_to_rfc1123, (png_structrp png_ptr, 1160 png_const_timep ptime),PNG_DEPRECATED); 1161 #endif 1162 PNG_EXPORT(241, int, png_convert_to_rfc1123_buffer, (char out[29], 1163 png_const_timep ptime)); 1164 #endif 1165 1166 #ifdef PNG_CONVERT_tIME_SUPPORTED 1167 /* Convert from a struct tm to png_time */ 1168 PNG_EXPORT(24, void, png_convert_from_struct_tm, (png_timep ptime, 1169 const struct tm * ttime)); 1170 1171 /* Convert from time_t to png_time. Uses gmtime() */ 1172 PNG_EXPORT(25, void, png_convert_from_time_t, (png_timep ptime, time_t ttime)); 1173 #endif /* PNG_CONVERT_tIME_SUPPORTED */ 1174 1175 #ifdef PNG_READ_EXPAND_SUPPORTED 1176 /* Expand data to 24-bit RGB, or 8-bit grayscale, with alpha if available. */ 1177 PNG_EXPORT(26, void, png_set_expand, (png_structrp png_ptr)); 1178 PNG_EXPORT(27, void, png_set_expand_gray_1_2_4_to_8, (png_structrp png_ptr)); 1179 PNG_EXPORT(28, void, png_set_palette_to_rgb, (png_structrp png_ptr)); 1180 PNG_EXPORT(29, void, png_set_tRNS_to_alpha, (png_structrp png_ptr)); 1181 #endif 1182 1183 #ifdef PNG_READ_EXPAND_16_SUPPORTED 1184 /* Expand to 16-bit channels, forces conversion of palette to RGB and expansion 1185 * of a tRNS chunk if present. 1186 */ 1187 PNG_EXPORT(221, void, png_set_expand_16, (png_structrp png_ptr)); 1188 #endif 1189 1190 #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED) 1191 /* Use blue, green, red order for pixels. */ 1192 PNG_EXPORT(30, void, png_set_bgr, (png_structrp png_ptr)); 1193 #endif 1194 1195 #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED 1196 /* Expand the grayscale to 24-bit RGB if necessary. */ 1197 PNG_EXPORT(31, void, png_set_gray_to_rgb, (png_structrp png_ptr)); 1198 #endif 1199 1200 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED 1201 /* Reduce RGB to grayscale. */ 1202 #define PNG_ERROR_ACTION_NONE 1 1203 #define PNG_ERROR_ACTION_WARN 2 1204 #define PNG_ERROR_ACTION_ERROR 3 1205 #define PNG_RGB_TO_GRAY_DEFAULT (-1)/*for red/green coefficients*/ 1206 1207 PNG_FP_EXPORT(32, void, png_set_rgb_to_gray, (png_structrp png_ptr, 1208 int error_action, double red, double green)) 1209 PNG_FIXED_EXPORT(33, void, png_set_rgb_to_gray_fixed, (png_structrp png_ptr, 1210 int error_action, png_fixed_point red, png_fixed_point green)) 1211 1212 PNG_EXPORT(34, png_byte, png_get_rgb_to_gray_status, (png_const_structrp 1213 png_ptr)); 1214 #endif 1215 1216 #ifdef PNG_BUILD_GRAYSCALE_PALETTE_SUPPORTED 1217 PNG_EXPORT(35, void, png_build_grayscale_palette, (int bit_depth, 1218 png_colorp palette)); 1219 #endif 1220 1221 #ifdef PNG_READ_ALPHA_MODE_SUPPORTED 1222 /* How the alpha channel is interpreted - this affects how the color channels 1223 * of a PNG file are returned to the calling application when an alpha channel, 1224 * or a tRNS chunk in a palette file, is present. 1225 * 1226 * This has no effect on the way pixels are written into a PNG output 1227 * datastream. The color samples in a PNG datastream are never premultiplied 1228 * with the alpha samples. 1229 * 1230 * The default is to return data according to the PNG specification: the alpha 1231 * channel is a linear measure of the contribution of the pixel to the 1232 * corresponding composited pixel, and the color channels are unassociated 1233 * (not premultiplied). The gamma encoded color channels must be scaled 1234 * according to the contribution and to do this it is necessary to undo 1235 * the encoding, scale the color values, perform the composition and reencode 1236 * the values. This is the 'PNG' mode. 1237 * 1238 * The alternative is to 'associate' the alpha with the color information by 1239 * storing color channel values that have been scaled by the alpha. 1240 * image. These are the 'STANDARD', 'ASSOCIATED' or 'PREMULTIPLIED' modes 1241 * (the latter being the two common names for associated alpha color channels). 1242 * 1243 * For the 'OPTIMIZED' mode, a pixel is treated as opaque only if the alpha 1244 * value is equal to the maximum value. 1245 * 1246 * The final choice is to gamma encode the alpha channel as well. This is 1247 * broken because, in practice, no implementation that uses this choice 1248 * correctly undoes the encoding before handling alpha composition. Use this 1249 * choice only if other serious errors in the software or hardware you use 1250 * mandate it; the typical serious error is for dark halos to appear around 1251 * opaque areas of the composited PNG image because of arithmetic overflow. 1252 * 1253 * The API function png_set_alpha_mode specifies which of these choices to use 1254 * with an enumerated 'mode' value and the gamma of the required output: 1255 */ 1256 #define PNG_ALPHA_PNG 0 /* according to the PNG standard */ 1257 #define PNG_ALPHA_STANDARD 1 /* according to Porter/Duff */ 1258 #define PNG_ALPHA_ASSOCIATED 1 /* as above; this is the normal practice */ 1259 #define PNG_ALPHA_PREMULTIPLIED 1 /* as above */ 1260 #define PNG_ALPHA_OPTIMIZED 2 /* 'PNG' for opaque pixels, else 'STANDARD' */ 1261 #define PNG_ALPHA_BROKEN 3 /* the alpha channel is gamma encoded */ 1262 1263 PNG_FP_EXPORT(227, void, png_set_alpha_mode, (png_structrp png_ptr, int mode, 1264 double output_gamma)) 1265 PNG_FIXED_EXPORT(228, void, png_set_alpha_mode_fixed, (png_structrp png_ptr, 1266 int mode, png_fixed_point output_gamma)) 1267 #endif 1268 1269 #if defined(PNG_GAMMA_SUPPORTED) || defined(PNG_READ_ALPHA_MODE_SUPPORTED) 1270 /* The output_gamma value is a screen gamma in libpng terminology: it expresses 1271 * how to decode the output values, not how they are encoded. 1272 */ 1273 #define PNG_DEFAULT_sRGB -1 /* sRGB gamma and color space */ 1274 #define PNG_GAMMA_MAC_18 -2 /* Old Mac '1.8' gamma and color space */ 1275 #define PNG_GAMMA_sRGB 220000 /* Television standards--matches sRGB gamma */ 1276 #define PNG_GAMMA_LINEAR PNG_FP_1 /* Linear */ 1277 #endif 1278 1279 /* The following are examples of calls to png_set_alpha_mode to achieve the 1280 * required overall gamma correction and, where necessary, alpha 1281 * premultiplication. 1282 * 1283 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB); 1284 * This is the default libpng handling of the alpha channel - it is not 1285 * pre-multiplied into the color components. In addition the call states 1286 * that the output is for a sRGB system and causes all PNG files without gAMA 1287 * chunks to be assumed to be encoded using sRGB. 1288 * 1289 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC); 1290 * In this case the output is assumed to be something like an sRGB conformant 1291 * display preceeded by a power-law lookup table of power 1.45. This is how 1292 * early Mac systems behaved. 1293 * 1294 * png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_GAMMA_LINEAR); 1295 * This is the classic Jim Blinn approach and will work in academic 1296 * environments where everything is done by the book. It has the shortcoming 1297 * of assuming that input PNG data with no gamma information is linear - this 1298 * is unlikely to be correct unless the PNG files where generated locally. 1299 * Most of the time the output precision will be so low as to show 1300 * significant banding in dark areas of the image. 1301 * 1302 * png_set_expand_16(pp); 1303 * png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_DEFAULT_sRGB); 1304 * This is a somewhat more realistic Jim Blinn inspired approach. PNG files 1305 * are assumed to have the sRGB encoding if not marked with a gamma value and 1306 * the output is always 16 bits per component. This permits accurate scaling 1307 * and processing of the data. If you know that your input PNG files were 1308 * generated locally you might need to replace PNG_DEFAULT_sRGB with the 1309 * correct value for your system. 1310 * 1311 * png_set_alpha_mode(pp, PNG_ALPHA_OPTIMIZED, PNG_DEFAULT_sRGB); 1312 * If you just need to composite the PNG image onto an existing background 1313 * and if you control the code that does this you can use the optimization 1314 * setting. In this case you just copy completely opaque pixels to the 1315 * output. For pixels that are not completely transparent (you just skip 1316 * those) you do the composition math using png_composite or png_composite_16 1317 * below then encode the resultant 8-bit or 16-bit values to match the output 1318 * encoding. 1319 * 1320 * Other cases 1321 * If neither the PNG nor the standard linear encoding work for you because 1322 * of the software or hardware you use then you have a big problem. The PNG 1323 * case will probably result in halos around the image. The linear encoding 1324 * will probably result in a washed out, too bright, image (it's actually too 1325 * contrasty.) Try the ALPHA_OPTIMIZED mode above - this will probably 1326 * substantially reduce the halos. Alternatively try: 1327 * 1328 * png_set_alpha_mode(pp, PNG_ALPHA_BROKEN, PNG_DEFAULT_sRGB); 1329 * This option will also reduce the halos, but there will be slight dark 1330 * halos round the opaque parts of the image where the background is light. 1331 * In the OPTIMIZED mode the halos will be light halos where the background 1332 * is dark. Take your pick - the halos are unavoidable unless you can get 1333 * your hardware/software fixed! (The OPTIMIZED approach is slightly 1334 * faster.) 1335 * 1336 * When the default gamma of PNG files doesn't match the output gamma. 1337 * If you have PNG files with no gamma information png_set_alpha_mode allows 1338 * you to provide a default gamma, but it also sets the ouput gamma to the 1339 * matching value. If you know your PNG files have a gamma that doesn't 1340 * match the output you can take advantage of the fact that 1341 * png_set_alpha_mode always sets the output gamma but only sets the PNG 1342 * default if it is not already set: 1343 * 1344 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB); 1345 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC); 1346 * The first call sets both the default and the output gamma values, the 1347 * second call overrides the output gamma without changing the default. This 1348 * is easier than achieving the same effect with png_set_gamma. You must use 1349 * PNG_ALPHA_PNG for the first call - internal checking in png_set_alpha will 1350 * fire if more than one call to png_set_alpha_mode and png_set_background is 1351 * made in the same read operation, however multiple calls with PNG_ALPHA_PNG 1352 * are ignored. 1353 */ 1354 1355 #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED 1356 PNG_EXPORT(36, void, png_set_strip_alpha, (png_structrp png_ptr)); 1357 #endif 1358 1359 #if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \ 1360 defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED) 1361 PNG_EXPORT(37, void, png_set_swap_alpha, (png_structrp png_ptr)); 1362 #endif 1363 1364 #if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \ 1365 defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED) 1366 PNG_EXPORT(38, void, png_set_invert_alpha, (png_structrp png_ptr)); 1367 #endif 1368 1369 #if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED) 1370 /* Add a filler byte to 8-bit Gray or 24-bit RGB images. */ 1371 PNG_EXPORT(39, void, png_set_filler, (png_structrp png_ptr, png_uint_32 filler, 1372 int flags)); 1373 /* The values of the PNG_FILLER_ defines should NOT be changed */ 1374 # define PNG_FILLER_BEFORE 0 1375 # define PNG_FILLER_AFTER 1 1376 /* Add an alpha byte to 8-bit Gray or 24-bit RGB images. */ 1377 PNG_EXPORT(40, void, png_set_add_alpha, (png_structrp png_ptr, 1378 png_uint_32 filler, int flags)); 1379 #endif /* PNG_READ_FILLER_SUPPORTED || PNG_WRITE_FILLER_SUPPORTED */ 1380 1381 #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED) 1382 /* Swap bytes in 16-bit depth files. */ 1383 PNG_EXPORT(41, void, png_set_swap, (png_structrp png_ptr)); 1384 #endif 1385 1386 #if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED) 1387 /* Use 1 byte per pixel in 1, 2, or 4-bit depth files. */ 1388 PNG_EXPORT(42, void, png_set_packing, (png_structrp png_ptr)); 1389 #endif 1390 1391 #if defined(PNG_READ_PACKSWAP_SUPPORTED) || \ 1392 defined(PNG_WRITE_PACKSWAP_SUPPORTED) 1393 /* Swap packing order of pixels in bytes. */ 1394 PNG_EXPORT(43, void, png_set_packswap, (png_structrp png_ptr)); 1395 #endif 1396 1397 #if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED) 1398 /* Converts files to legal bit depths. */ 1399 PNG_EXPORT(44, void, png_set_shift, (png_structrp png_ptr, png_const_color_8p 1400 true_bits)); 1401 #endif 1402 1403 #if defined(PNG_READ_INTERLACING_SUPPORTED) || \ 1404 defined(PNG_WRITE_INTERLACING_SUPPORTED) 1405 /* Have the code handle the interlacing. Returns the number of passes. 1406 * MUST be called before png_read_update_info or png_start_read_image, 1407 * otherwise it will not have the desired effect. Note that it is still 1408 * necessary to call png_read_row or png_read_rows png_get_image_height 1409 * times for each pass. 1410 */ 1411 PNG_EXPORT(45, int, png_set_interlace_handling, (png_structrp png_ptr)); 1412 #endif 1413 1414 #if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED) 1415 /* Invert monochrome files */ 1416 PNG_EXPORT(46, void, png_set_invert_mono, (png_structrp png_ptr)); 1417 #endif 1418 1419 #ifdef PNG_READ_BACKGROUND_SUPPORTED 1420 /* Handle alpha and tRNS by replacing with a background color. Prior to 1421 * libpng-1.5.4 this API must not be called before the PNG file header has been 1422 * read. Doing so will result in unexpected behavior and possible warnings or 1423 * errors if the PNG file contains a bKGD chunk. 1424 */ 1425 PNG_FP_EXPORT(47, void, png_set_background, (png_structrp png_ptr, 1426 png_const_color_16p background_color, int background_gamma_code, 1427 int need_expand, double background_gamma)) 1428 PNG_FIXED_EXPORT(215, void, png_set_background_fixed, (png_structrp png_ptr, 1429 png_const_color_16p background_color, int background_gamma_code, 1430 int need_expand, png_fixed_point background_gamma)) 1431 #endif 1432 #ifdef PNG_READ_BACKGROUND_SUPPORTED 1433 # define PNG_BACKGROUND_GAMMA_UNKNOWN 0 1434 # define PNG_BACKGROUND_GAMMA_SCREEN 1 1435 # define PNG_BACKGROUND_GAMMA_FILE 2 1436 # define PNG_BACKGROUND_GAMMA_UNIQUE 3 1437 #endif 1438 1439 #ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED 1440 /* Scale a 16-bit depth file down to 8-bit, accurately. */ 1441 PNG_EXPORT(229, void, png_set_scale_16, (png_structrp png_ptr)); 1442 #endif 1443 1444 #ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED 1445 #define PNG_READ_16_TO_8 SUPPORTED /* Name prior to 1.5.4 */ 1446 /* Strip the second byte of information from a 16-bit depth file. */ 1447 PNG_EXPORT(48, void, png_set_strip_16, (png_structrp png_ptr)); 1448 #endif 1449 1450 #ifdef PNG_READ_QUANTIZE_SUPPORTED 1451 /* Turn on quantizing, and reduce the palette to the number of colors 1452 * available. 1453 */ 1454 PNG_EXPORT(49, void, png_set_quantize, (png_structrp png_ptr, 1455 png_colorp palette, int num_palette, int maximum_colors, 1456 png_const_uint_16p histogram, int full_quantize)); 1457 #endif 1458 1459 #ifdef PNG_READ_GAMMA_SUPPORTED 1460 /* The threshold on gamma processing is configurable but hard-wired into the 1461 * library. The following is the floating point variant. 1462 */ 1463 #define PNG_GAMMA_THRESHOLD (PNG_GAMMA_THRESHOLD_FIXED*.00001) 1464 1465 /* Handle gamma correction. Screen_gamma=(display_exponent). 1466 * NOTE: this API simply sets the screen and file gamma values. It will 1467 * therefore override the value for gamma in a PNG file if it is called after 1468 * the file header has been read - use with care - call before reading the PNG 1469 * file for best results! 1470 * 1471 * These routines accept the same gamma values as png_set_alpha_mode (described 1472 * above). The PNG_GAMMA_ defines and PNG_DEFAULT_sRGB can be passed to either 1473 * API (floating point or fixed.) Notice, however, that the 'file_gamma' value 1474 * is the inverse of a 'screen gamma' value. 1475 */ 1476 PNG_FP_EXPORT(50, void, png_set_gamma, (png_structrp png_ptr, 1477 double screen_gamma, double override_file_gamma)) 1478 PNG_FIXED_EXPORT(208, void, png_set_gamma_fixed, (png_structrp png_ptr, 1479 png_fixed_point screen_gamma, png_fixed_point override_file_gamma)) 1480 #endif 1481 1482 #ifdef PNG_WRITE_FLUSH_SUPPORTED 1483 /* Set how many lines between output flushes - 0 for no flushing */ 1484 PNG_EXPORT(51, void, png_set_flush, (png_structrp png_ptr, int nrows)); 1485 /* Flush the current PNG output buffer */ 1486 PNG_EXPORT(52, void, png_write_flush, (png_structrp png_ptr)); 1487 #endif 1488 1489 /* Optional update palette with requested transformations */ 1490 PNG_EXPORT(53, void, png_start_read_image, (png_structrp png_ptr)); 1491 1492 /* Optional call to update the users info structure */ 1493 PNG_EXPORT(54, void, png_read_update_info, (png_structrp png_ptr, 1494 png_inforp info_ptr)); 1495 1496 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED 1497 /* Read one or more rows of image data. */ 1498 PNG_EXPORT(55, void, png_read_rows, (png_structrp png_ptr, png_bytepp row, 1499 png_bytepp display_row, png_uint_32 num_rows)); 1500 #endif 1501 1502 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED 1503 /* Read a row of data. */ 1504 PNG_EXPORT(56, void, png_read_row, (png_structrp png_ptr, png_bytep row, 1505 png_bytep display_row)); 1506 #endif 1507 1508 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED 1509 /* Read the whole image into memory at once. */ 1510 PNG_EXPORT(57, void, png_read_image, (png_structrp png_ptr, png_bytepp image)); 1511 #endif 1512 1513 /* Write a row of image data */ 1514 PNG_EXPORT(58, void, png_write_row, (png_structrp png_ptr, 1515 png_const_bytep row)); 1516 1517 /* Write a few rows of image data: (*row) is not written; however, the type 1518 * is declared as writeable to maintain compatibility with previous versions 1519 * of libpng and to allow the 'display_row' array from read_rows to be passed 1520 * unchanged to write_rows. 1521 */ 1522 PNG_EXPORT(59, void, png_write_rows, (png_structrp png_ptr, png_bytepp row, 1523 png_uint_32 num_rows)); 1524 1525 /* Write the image data */ 1526 PNG_EXPORT(60, void, png_write_image, (png_structrp png_ptr, png_bytepp image)); 1527 1528 /* Write the end of the PNG file. */ 1529 PNG_EXPORT(61, void, png_write_end, (png_structrp png_ptr, 1530 png_inforp info_ptr)); 1531 1532 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED 1533 /* Read the end of the PNG file. */ 1534 PNG_EXPORT(62, void, png_read_end, (png_structrp png_ptr, png_inforp info_ptr)); 1535 #endif 1536 1537 /* Free any memory associated with the png_info_struct */ 1538 PNG_EXPORT(63, void, png_destroy_info_struct, (png_const_structrp png_ptr, 1539 png_infopp info_ptr_ptr)); 1540 1541 /* Free any memory associated with the png_struct and the png_info_structs */ 1542 PNG_EXPORT(64, void, png_destroy_read_struct, (png_structpp png_ptr_ptr, 1543 png_infopp info_ptr_ptr, png_infopp end_info_ptr_ptr)); 1544 1545 /* Free any memory associated with the png_struct and the png_info_structs */ 1546 PNG_EXPORT(65, void, png_destroy_write_struct, (png_structpp png_ptr_ptr, 1547 png_infopp info_ptr_ptr)); 1548 1549 /* Set the libpng method of handling chunk CRC errors */ 1550 PNG_EXPORT(66, void, png_set_crc_action, (png_structrp png_ptr, int crit_action, 1551 int ancil_action)); 1552 1553 /* Values for png_set_crc_action() say how to handle CRC errors in 1554 * ancillary and critical chunks, and whether to use the data contained 1555 * therein. Note that it is impossible to "discard" data in a critical 1556 * chunk. For versions prior to 0.90, the action was always error/quit, 1557 * whereas in version 0.90 and later, the action for CRC errors in ancillary 1558 * chunks is warn/discard. These values should NOT be changed. 1559 * 1560 * value action:critical action:ancillary 1561 */ 1562 #define PNG_CRC_DEFAULT 0 /* error/quit warn/discard data */ 1563 #define PNG_CRC_ERROR_QUIT 1 /* error/quit error/quit */ 1564 #define PNG_CRC_WARN_DISCARD 2 /* (INVALID) warn/discard data */ 1565 #define PNG_CRC_WARN_USE 3 /* warn/use data warn/use data */ 1566 #define PNG_CRC_QUIET_USE 4 /* quiet/use data quiet/use data */ 1567 #define PNG_CRC_NO_CHANGE 5 /* use current value use current value */ 1568 1569 /* These functions give the user control over the scan-line filtering in 1570 * libpng and the compression methods used by zlib. These functions are 1571 * mainly useful for testing, as the defaults should work with most users. 1572 * Those users who are tight on memory or want faster performance at the 1573 * expense of compression can modify them. See the compression library 1574 * header file (zlib.h) for an explination of the compression functions. 1575 */ 1576 1577 /* Set the filtering method(s) used by libpng. Currently, the only valid 1578 * value for "method" is 0. 1579 */ 1580 PNG_EXPORT(67, void, png_set_filter, (png_structrp png_ptr, int method, 1581 int filters)); 1582 1583 /* Flags for png_set_filter() to say which filters to use. The flags 1584 * are chosen so that they don't conflict with real filter types 1585 * below, in case they are supplied instead of the #defined constants. 1586 * These values should NOT be changed. 1587 */ 1588 #define PNG_NO_FILTERS 0x00 1589 #define PNG_FILTER_NONE 0x08 1590 #define PNG_FILTER_SUB 0x10 1591 #define PNG_FILTER_UP 0x20 1592 #define PNG_FILTER_AVG 0x40 1593 #define PNG_FILTER_PAETH 0x80 1594 #define PNG_ALL_FILTERS (PNG_FILTER_NONE | PNG_FILTER_SUB | PNG_FILTER_UP | \ 1595 PNG_FILTER_AVG | PNG_FILTER_PAETH) 1596 1597 /* Filter values (not flags) - used in pngwrite.c, pngwutil.c for now. 1598 * These defines should NOT be changed. 1599 */ 1600 #define PNG_FILTER_VALUE_NONE 0 1601 #define PNG_FILTER_VALUE_SUB 1 1602 #define PNG_FILTER_VALUE_UP 2 1603 #define PNG_FILTER_VALUE_AVG 3 1604 #define PNG_FILTER_VALUE_PAETH 4 1605 #define PNG_FILTER_VALUE_LAST 5 1606 1607 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* EXPERIMENTAL */ 1608 /* The "heuristic_method" is given by one of the PNG_FILTER_HEURISTIC_ 1609 * defines, either the default (minimum-sum-of-absolute-differences), or 1610 * the experimental method (weighted-minimum-sum-of-absolute-differences). 1611 * 1612 * Weights are factors >= 1.0, indicating how important it is to keep the 1613 * filter type consistent between rows. Larger numbers mean the current 1614 * filter is that many times as likely to be the same as the "num_weights" 1615 * previous filters. This is cumulative for each previous row with a weight. 1616 * There needs to be "num_weights" values in "filter_weights", or it can be 1617 * NULL if the weights aren't being specified. Weights have no influence on 1618 * the selection of the first row filter. Well chosen weights can (in theory) 1619 * improve the compression for a given image. 1620 * 1621 * Costs are factors >= 1.0 indicating the relative decoding costs of a 1622 * filter type. Higher costs indicate more decoding expense, and are 1623 * therefore less likely to be selected over a filter with lower computational 1624 * costs. There needs to be a value in "filter_costs" for each valid filter 1625 * type (given by PNG_FILTER_VALUE_LAST), or it can be NULL if you aren't 1626 * setting the costs. Costs try to improve the speed of decompression without 1627 * unduly increasing the compressed image size. 1628 * 1629 * A negative weight or cost indicates the default value is to be used, and 1630 * values in the range [0.0, 1.0) indicate the value is to remain unchanged. 1631 * The default values for both weights and costs are currently 1.0, but may 1632 * change if good general weighting/cost heuristics can be found. If both 1633 * the weights and costs are set to 1.0, this degenerates the WEIGHTED method 1634 * to the UNWEIGHTED method, but with added encoding time/computation. 1635 */ 1636 PNG_FP_EXPORT(68, void, png_set_filter_heuristics, (png_structrp png_ptr, 1637 int heuristic_method, int num_weights, png_const_doublep filter_weights, 1638 png_const_doublep filter_costs)) 1639 PNG_FIXED_EXPORT(209, void, png_set_filter_heuristics_fixed, 1640 (png_structrp png_ptr, int heuristic_method, int num_weights, 1641 png_const_fixed_point_p filter_weights, 1642 png_const_fixed_point_p filter_costs)) 1643 #endif /* PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */ 1644 1645 /* Heuristic used for row filter selection. These defines should NOT be 1646 * changed. 1647 */ 1648 #define PNG_FILTER_HEURISTIC_DEFAULT 0 /* Currently "UNWEIGHTED" */ 1649 #define PNG_FILTER_HEURISTIC_UNWEIGHTED 1 /* Used by libpng < 0.95 */ 1650 #define PNG_FILTER_HEURISTIC_WEIGHTED 2 /* Experimental feature */ 1651 #define PNG_FILTER_HEURISTIC_LAST 3 /* Not a valid value */ 1652 1653 #ifdef PNG_WRITE_SUPPORTED 1654 /* Set the library compression level. Currently, valid values range from 1655 * 0 - 9, corresponding directly to the zlib compression levels 0 - 9 1656 * (0 - no compression, 9 - "maximal" compression). Note that tests have 1657 * shown that zlib compression levels 3-6 usually perform as well as level 9 1658 * for PNG images, and do considerably fewer caclulations. In the future, 1659 * these values may not correspond directly to the zlib compression levels. 1660 */ 1661 PNG_EXPORT(69, void, png_set_compression_level, (png_structrp png_ptr, 1662 int level)); 1663 1664 PNG_EXPORT(70, void, png_set_compression_mem_level, (png_structrp png_ptr, 1665 int mem_level)); 1666 1667 PNG_EXPORT(71, void, png_set_compression_strategy, (png_structrp png_ptr, 1668 int strategy)); 1669 1670 /* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a 1671 * smaller value of window_bits if it can do so safely. 1672 */ 1673 PNG_EXPORT(72, void, png_set_compression_window_bits, (png_structrp png_ptr, 1674 int window_bits)); 1675 1676 PNG_EXPORT(73, void, png_set_compression_method, (png_structrp png_ptr, 1677 int method)); 1678 #endif 1679 1680 #ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED 1681 /* Also set zlib parameters for compressing non-IDAT chunks */ 1682 PNG_EXPORT(222, void, png_set_text_compression_level, (png_structrp png_ptr, 1683 int level)); 1684 1685 PNG_EXPORT(223, void, png_set_text_compression_mem_level, (png_structrp png_ptr, 1686 int mem_level)); 1687 1688 PNG_EXPORT(224, void, png_set_text_compression_strategy, (png_structrp png_ptr, 1689 int strategy)); 1690 1691 /* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a 1692 * smaller value of window_bits if it can do so safely. 1693 */ 1694 PNG_EXPORT(225, void, png_set_text_compression_window_bits, 1695 (png_structrp png_ptr, int window_bits)); 1696 1697 PNG_EXPORT(226, void, png_set_text_compression_method, (png_structrp png_ptr, 1698 int method)); 1699 #endif /* PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED */ 1700 1701 /* These next functions are called for input/output, memory, and error 1702 * handling. They are in the file pngrio.c, pngwio.c, and pngerror.c, 1703 * and call standard C I/O routines such as fread(), fwrite(), and 1704 * fprintf(). These functions can be made to use other I/O routines 1705 * at run time for those applications that need to handle I/O in a 1706 * different manner by calling png_set_???_fn(). See libpng-manual.txt for 1707 * more information. 1708 */ 1709 1710 #ifdef PNG_STDIO_SUPPORTED 1711 /* Initialize the input/output for the PNG file to the default functions. */ 1712 PNG_EXPORT(74, void, png_init_io, (png_structrp png_ptr, png_FILE_p fp)); 1713 #endif 1714 1715 /* Replace the (error and abort), and warning functions with user 1716 * supplied functions. If no messages are to be printed you must still 1717 * write and use replacement functions. The replacement error_fn should 1718 * still do a longjmp to the last setjmp location if you are using this 1719 * method of error handling. If error_fn or warning_fn is NULL, the 1720 * default function will be used. 1721 */ 1722 1723 PNG_EXPORT(75, void, png_set_error_fn, (png_structrp png_ptr, 1724 png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warning_fn)); 1725 1726 /* Return the user pointer associated with the error functions */ 1727 PNG_EXPORT(76, png_voidp, png_get_error_ptr, (png_const_structrp png_ptr)); 1728 1729 /* Replace the default data output functions with a user supplied one(s). 1730 * If buffered output is not used, then output_flush_fn can be set to NULL. 1731 * If PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile time 1732 * output_flush_fn will be ignored (and thus can be NULL). 1733 * It is probably a mistake to use NULL for output_flush_fn if 1734 * write_data_fn is not also NULL unless you have built libpng with 1735 * PNG_WRITE_FLUSH_SUPPORTED undefined, because in this case libpng's 1736 * default flush function, which uses the standard *FILE structure, will 1737 * be used. 1738 */ 1739 PNG_EXPORT(77, void, png_set_write_fn, (png_structrp png_ptr, png_voidp io_ptr, 1740 png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn)); 1741 1742 /* Replace the default data input function with a user supplied one. */ 1743 PNG_EXPORT(78, void, png_set_read_fn, (png_structrp png_ptr, png_voidp io_ptr, 1744 png_rw_ptr read_data_fn)); 1745 1746 /* Return the user pointer associated with the I/O functions */ 1747 PNG_EXPORT(79, png_voidp, png_get_io_ptr, (png_const_structrp png_ptr)); 1748 1749 PNG_EXPORT(80, void, png_set_read_status_fn, (png_structrp png_ptr, 1750 png_read_status_ptr read_row_fn)); 1751 1752 PNG_EXPORT(81, void, png_set_write_status_fn, (png_structrp png_ptr, 1753 png_write_status_ptr write_row_fn)); 1754 1755 #ifdef PNG_USER_MEM_SUPPORTED 1756 /* Replace the default memory allocation functions with user supplied one(s). */ 1757 PNG_EXPORT(82, void, png_set_mem_fn, (png_structrp png_ptr, png_voidp mem_ptr, 1758 png_malloc_ptr malloc_fn, png_free_ptr free_fn)); 1759 /* Return the user pointer associated with the memory functions */ 1760 PNG_EXPORT(83, png_voidp, png_get_mem_ptr, (png_const_structrp png_ptr)); 1761 #endif 1762 1763 #ifdef PNG_READ_USER_TRANSFORM_SUPPORTED 1764 PNG_EXPORT(84, void, png_set_read_user_transform_fn, (png_structrp png_ptr, 1765 png_user_transform_ptr read_user_transform_fn)); 1766 #endif 1767 1768 #ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED 1769 PNG_EXPORT(85, void, png_set_write_user_transform_fn, (png_structrp png_ptr, 1770 png_user_transform_ptr write_user_transform_fn)); 1771 #endif 1772 1773 #ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED 1774 PNG_EXPORT(86, void, png_set_user_transform_info, (png_structrp png_ptr, 1775 png_voidp user_transform_ptr, int user_transform_depth, 1776 int user_transform_channels)); 1777 /* Return the user pointer associated with the user transform functions */ 1778 PNG_EXPORT(87, png_voidp, png_get_user_transform_ptr, 1779 (png_const_structrp png_ptr)); 1780 #endif 1781 1782 #ifdef PNG_USER_TRANSFORM_INFO_SUPPORTED 1783 /* Return information about the row currently being processed. Note that these 1784 * APIs do not fail but will return unexpected results if called outside a user 1785 * transform callback. Also note that when transforming an interlaced image the 1786 * row number is the row number within the sub-image of the interlace pass, so 1787 * the value will increase to the height of the sub-image (not the full image) 1788 * then reset to 0 for the next pass. 1789 * 1790 * Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to 1791 * find the output pixel (x,y) given an interlaced sub-image pixel 1792 * (row,col,pass). (See below for these macros.) 1793 */ 1794 PNG_EXPORT(217, png_uint_32, png_get_current_row_number, (png_const_structrp)); 1795 PNG_EXPORT(218, png_byte, png_get_current_pass_number, (png_const_structrp)); 1796 #endif 1797 1798 #ifdef PNG_READ_USER_CHUNKS_SUPPORTED 1799 /* This callback is called only for *unknown* chunks. If 1800 * PNG_HANDLE_AS_UNKNOWN_SUPPORTED is set then it is possible to set known 1801 * chunks to be treated as unknown, however in this case the callback must do 1802 * any processing required by the chunk (e.g. by calling the appropriate 1803 * png_set_ APIs.) 1804 * 1805 * There is no write support - on write, by default, all the chunks in the 1806 * 'unknown' list are written in the specified position. 1807 * 1808 * The integer return from the callback function is interpreted thus: 1809 * 1810 * negative: An error occured, png_chunk_error will be called. 1811 * zero: The chunk was not handled, the chunk will be saved. A critical 1812 * chunk will cause an error at this point unless it is to be saved. 1813 * positive: The chunk was handled, libpng will ignore/discard it. 1814 * 1815 * See "INTERACTION WTIH USER CHUNK CALLBACKS" below for important notes about 1816 * how this behavior will change in libpng 1.7 1817 */ 1818 PNG_EXPORT(88, void, png_set_read_user_chunk_fn, (png_structrp png_ptr, 1819 png_voidp user_chunk_ptr, png_user_chunk_ptr read_user_chunk_fn)); 1820 #endif 1821 1822 #ifdef PNG_USER_CHUNKS_SUPPORTED 1823 PNG_EXPORT(89, png_voidp, png_get_user_chunk_ptr, (png_const_structrp png_ptr)); 1824 #endif 1825 1826 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED 1827 /* Sets the function callbacks for the push reader, and a pointer to a 1828 * user-defined structure available to the callback functions. 1829 */ 1830 PNG_EXPORT(90, void, png_set_progressive_read_fn, (png_structrp png_ptr, 1831 png_voidp progressive_ptr, png_progressive_info_ptr info_fn, 1832 png_progressive_row_ptr row_fn, png_progressive_end_ptr end_fn)); 1833 1834 /* Returns the user pointer associated with the push read functions */ 1835 PNG_EXPORT(91, png_voidp, png_get_progressive_ptr, 1836 (png_const_structrp png_ptr)); 1837 1838 /* Function to be called when data becomes available */ 1839 PNG_EXPORT(92, void, png_process_data, (png_structrp png_ptr, 1840 png_inforp info_ptr, png_bytep buffer, png_size_t buffer_size)); 1841 1842 /* A function which may be called *only* within png_process_data to stop the 1843 * processing of any more data. The function returns the number of bytes 1844 * remaining, excluding any that libpng has cached internally. A subsequent 1845 * call to png_process_data must supply these bytes again. If the argument 1846 * 'save' is set to true the routine will first save all the pending data and 1847 * will always return 0. 1848 */ 1849 PNG_EXPORT(219, png_size_t, png_process_data_pause, (png_structrp, int save)); 1850 1851 /* A function which may be called *only* outside (after) a call to 1852 * png_process_data. It returns the number of bytes of data to skip in the 1853 * input. Normally it will return 0, but if it returns a non-zero value the 1854 * application must skip than number of bytes of input data and pass the 1855 * following data to the next call to png_process_data. 1856 */ 1857 PNG_EXPORT(220, png_uint_32, png_process_data_skip, (png_structrp)); 1858 1859 /* Function that combines rows. 'new_row' is a flag that should come from 1860 * the callback and be non-NULL if anything needs to be done; the library 1861 * stores its own version of the new data internally and ignores the passed 1862 * in value. 1863 */ 1864 PNG_EXPORT(93, void, png_progressive_combine_row, (png_const_structrp png_ptr, 1865 png_bytep old_row, png_const_bytep new_row)); 1866 #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */ 1867 1868 PNG_EXPORTA(94, png_voidp, png_malloc, (png_const_structrp png_ptr, 1869 png_alloc_size_t size), PNG_ALLOCATED); 1870 /* Added at libpng version 1.4.0 */ 1871 PNG_EXPORTA(95, png_voidp, png_calloc, (png_const_structrp png_ptr, 1872 png_alloc_size_t size), PNG_ALLOCATED); 1873 1874 /* Added at libpng version 1.2.4 */ 1875 PNG_EXPORTA(96, png_voidp, png_malloc_warn, (png_const_structrp png_ptr, 1876 png_alloc_size_t size), PNG_ALLOCATED); 1877 1878 /* Frees a pointer allocated by png_malloc() */ 1879 PNG_EXPORT(97, void, png_free, (png_const_structrp png_ptr, png_voidp ptr)); 1880 1881 /* Free data that was allocated internally */ 1882 PNG_EXPORT(98, void, png_free_data, (png_const_structrp png_ptr, 1883 png_inforp info_ptr, png_uint_32 free_me, int num)); 1884 1885 /* Reassign responsibility for freeing existing data, whether allocated 1886 * by libpng or by the application; this works on the png_info structure passed 1887 * in, it does not change the state for other png_info structures. 1888 * 1889 * It is unlikely that this function works correctly as of 1.6.0 and using it 1890 * may result either in memory leaks or double free of allocated data. 1891 */ 1892 PNG_EXPORT(99, void, png_data_freer, (png_const_structrp png_ptr, 1893 png_inforp info_ptr, int freer, png_uint_32 mask)); 1894 1895 /* Assignments for png_data_freer */ 1896 #define PNG_DESTROY_WILL_FREE_DATA 1 1897 #define PNG_SET_WILL_FREE_DATA 1 1898 #define PNG_USER_WILL_FREE_DATA 2 1899 /* Flags for png_ptr->free_me and info_ptr->free_me */ 1900 #define PNG_FREE_HIST 0x0008 1901 #define PNG_FREE_ICCP 0x0010 1902 #define PNG_FREE_SPLT 0x0020 1903 #define PNG_FREE_ROWS 0x0040 1904 #define PNG_FREE_PCAL 0x0080 1905 #define PNG_FREE_SCAL 0x0100 1906 #ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED 1907 # define PNG_FREE_UNKN 0x0200 1908 #endif 1909 /* PNG_FREE_LIST 0x0400 removed in 1.6.0 because it is ignored */ 1910 #define PNG_FREE_PLTE 0x1000 1911 #define PNG_FREE_TRNS 0x2000 1912 #define PNG_FREE_TEXT 0x4000 1913 #define PNG_FREE_ALL 0x7fff 1914 #define PNG_FREE_MUL 0x4220 /* PNG_FREE_SPLT|PNG_FREE_TEXT|PNG_FREE_UNKN */ 1915 1916 #ifdef PNG_USER_MEM_SUPPORTED 1917 PNG_EXPORTA(100, png_voidp, png_malloc_default, (png_const_structrp png_ptr, 1918 png_alloc_size_t size), PNG_ALLOCATED PNG_DEPRECATED); 1919 PNG_EXPORTA(101, void, png_free_default, (png_const_structrp png_ptr, 1920 png_voidp ptr), PNG_DEPRECATED); 1921 #endif 1922 1923 #ifdef PNG_ERROR_TEXT_SUPPORTED 1924 /* Fatal error in PNG image of libpng - can't continue */ 1925 PNG_EXPORTA(102, void, png_error, (png_const_structrp png_ptr, 1926 png_const_charp error_message), PNG_NORETURN); 1927 1928 /* The same, but the chunk name is prepended to the error string. */ 1929 PNG_EXPORTA(103, void, png_chunk_error, (png_const_structrp png_ptr, 1930 png_const_charp error_message), PNG_NORETURN); 1931 1932 #else 1933 /* Fatal error in PNG image of libpng - can't continue */ 1934 PNG_EXPORTA(104, void, png_err, (png_const_structrp png_ptr), PNG_NORETURN); 1935 # define png_error(s1,s2) png_err(s1) 1936 # define png_chunk_error(s1,s2) png_err(s1) 1937 #endif 1938 1939 #ifdef PNG_WARNINGS_SUPPORTED 1940 /* Non-fatal error in libpng. Can continue, but may have a problem. */ 1941 PNG_EXPORT(105, void, png_warning, (png_const_structrp png_ptr, 1942 png_const_charp warning_message)); 1943 1944 /* Non-fatal error in libpng, chunk name is prepended to message. */ 1945 PNG_EXPORT(106, void, png_chunk_warning, (png_const_structrp png_ptr, 1946 png_const_charp warning_message)); 1947 #else 1948 # define png_warning(s1,s2) ((void)(s1)) 1949 # define png_chunk_warning(s1,s2) ((void)(s1)) 1950 #endif 1951 1952 #ifdef PNG_BENIGN_ERRORS_SUPPORTED 1953 /* Benign error in libpng. Can continue, but may have a problem. 1954 * User can choose whether to handle as a fatal error or as a warning. */ 1955 PNG_EXPORT(107, void, png_benign_error, (png_const_structrp png_ptr, 1956 png_const_charp warning_message)); 1957 1958 #ifdef PNG_READ_SUPPORTED 1959 /* Same, chunk name is prepended to message (only during read) */ 1960 PNG_EXPORT(108, void, png_chunk_benign_error, (png_const_structrp png_ptr, 1961 png_const_charp warning_message)); 1962 #endif 1963 1964 PNG_EXPORT(109, void, png_set_benign_errors, 1965 (png_structrp png_ptr, int allowed)); 1966 #else 1967 # ifdef PNG_ALLOW_BENIGN_ERRORS 1968 # define png_benign_error png_warning 1969 # define png_chunk_benign_error png_chunk_warning 1970 # else 1971 # define png_benign_error png_error 1972 # define png_chunk_benign_error png_chunk_error 1973 # endif 1974 #endif 1975 1976 /* The png_set_<chunk> functions are for storing values in the png_info_struct. 1977 * Similarly, the png_get_<chunk> calls are used to read values from the 1978 * png_info_struct, either storing the parameters in the passed variables, or 1979 * setting pointers into the png_info_struct where the data is stored. The 1980 * png_get_<chunk> functions return a non-zero value if the data was available 1981 * in info_ptr, or return zero and do not change any of the parameters if the 1982 * data was not available. 1983 * 1984 * These functions should be used instead of directly accessing png_info 1985 * to avoid problems with future changes in the size and internal layout of 1986 * png_info_struct. 1987 */ 1988 /* Returns "flag" if chunk data is valid in info_ptr. */ 1989 PNG_EXPORT(110, png_uint_32, png_get_valid, (png_const_structrp png_ptr, 1990 png_const_inforp info_ptr, png_uint_32 flag)); 1991 1992 /* Returns number of bytes needed to hold a transformed row. */ 1993 PNG_EXPORT(111, png_size_t, png_get_rowbytes, (png_const_structrp png_ptr, 1994 png_const_inforp info_ptr)); 1995 1996 #ifdef PNG_INFO_IMAGE_SUPPORTED 1997 /* Returns row_pointers, which is an array of pointers to scanlines that was 1998 * returned from png_read_png(). 1999 */ 2000 PNG_EXPORT(112, png_bytepp, png_get_rows, (png_const_structrp png_ptr, 2001 png_const_inforp info_ptr)); 2002 2003 /* Set row_pointers, which is an array of pointers to scanlines for use 2004 * by png_write_png(). 2005 */ 2006 PNG_EXPORT(113, void, png_set_rows, (png_const_structrp png_ptr, 2007 png_inforp info_ptr, png_bytepp row_pointers)); 2008 #endif 2009 2010 /* Returns number of color channels in image. */ 2011 PNG_EXPORT(114, png_byte, png_get_channels, (png_const_structrp png_ptr, 2012 png_const_inforp info_ptr)); 2013 2014 #ifdef PNG_EASY_ACCESS_SUPPORTED 2015 /* Returns image width in pixels. */ 2016 PNG_EXPORT(115, png_uint_32, png_get_image_width, (png_const_structrp png_ptr, 2017 png_const_inforp info_ptr)); 2018 2019 /* Returns image height in pixels. */ 2020 PNG_EXPORT(116, png_uint_32, png_get_image_height, (png_const_structrp png_ptr, 2021 png_const_inforp info_ptr)); 2022 2023 /* Returns image bit_depth. */ 2024 PNG_EXPORT(117, png_byte, png_get_bit_depth, (png_const_structrp png_ptr, 2025 png_const_inforp info_ptr)); 2026 2027 /* Returns image color_type. */ 2028 PNG_EXPORT(118, png_byte, png_get_color_type, (png_const_structrp png_ptr, 2029 png_const_inforp info_ptr)); 2030 2031 /* Returns image filter_type. */ 2032 PNG_EXPORT(119, png_byte, png_get_filter_type, (png_const_structrp png_ptr, 2033 png_const_inforp info_ptr)); 2034 2035 /* Returns image interlace_type. */ 2036 PNG_EXPORT(120, png_byte, png_get_interlace_type, (png_const_structrp png_ptr, 2037 png_const_inforp info_ptr)); 2038 2039 /* Returns image compression_type. */ 2040 PNG_EXPORT(121, png_byte, png_get_compression_type, (png_const_structrp png_ptr, 2041 png_const_inforp info_ptr)); 2042 2043 /* Returns image resolution in pixels per meter, from pHYs chunk data. */ 2044 PNG_EXPORT(122, png_uint_32, png_get_pixels_per_meter, 2045 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 2046 PNG_EXPORT(123, png_uint_32, png_get_x_pixels_per_meter, 2047 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 2048 PNG_EXPORT(124, png_uint_32, png_get_y_pixels_per_meter, 2049 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 2050 2051 /* Returns pixel aspect ratio, computed from pHYs chunk data. */ 2052 PNG_FP_EXPORT(125, float, png_get_pixel_aspect_ratio, 2053 (png_const_structrp png_ptr, png_const_inforp info_ptr)) 2054 PNG_FIXED_EXPORT(210, png_fixed_point, png_get_pixel_aspect_ratio_fixed, 2055 (png_const_structrp png_ptr, png_const_inforp info_ptr)) 2056 2057 /* Returns image x, y offset in pixels or microns, from oFFs chunk data. */ 2058 PNG_EXPORT(126, png_int_32, png_get_x_offset_pixels, 2059 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 2060 PNG_EXPORT(127, png_int_32, png_get_y_offset_pixels, 2061 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 2062 PNG_EXPORT(128, png_int_32, png_get_x_offset_microns, 2063 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 2064 PNG_EXPORT(129, png_int_32, png_get_y_offset_microns, 2065 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 2066 2067 #endif /* PNG_EASY_ACCESS_SUPPORTED */ 2068 2069 #ifdef PNG_READ_SUPPORTED 2070 /* Returns pointer to signature string read from PNG header */ 2071 PNG_EXPORT(130, png_const_bytep, png_get_signature, (png_const_structrp png_ptr, 2072 png_const_inforp info_ptr)); 2073 #endif 2074 2075 #ifdef PNG_bKGD_SUPPORTED 2076 PNG_EXPORT(131, png_uint_32, png_get_bKGD, (png_const_structrp png_ptr, 2077 png_inforp info_ptr, png_color_16p *background)); 2078 #endif 2079 2080 #ifdef PNG_bKGD_SUPPORTED 2081 PNG_EXPORT(132, void, png_set_bKGD, (png_const_structrp png_ptr, 2082 png_inforp info_ptr, png_const_color_16p background)); 2083 #endif 2084 2085 #ifdef PNG_cHRM_SUPPORTED 2086 PNG_FP_EXPORT(133, png_uint_32, png_get_cHRM, (png_const_structrp png_ptr, 2087 png_const_inforp info_ptr, double *white_x, double *white_y, double *red_x, 2088 double *red_y, double *green_x, double *green_y, double *blue_x, 2089 double *blue_y)) 2090 PNG_FP_EXPORT(230, png_uint_32, png_get_cHRM_XYZ, (png_const_structrp png_ptr, 2091 png_const_inforp info_ptr, double *red_X, double *red_Y, double *red_Z, 2092 double *green_X, double *green_Y, double *green_Z, double *blue_X, 2093 double *blue_Y, double *blue_Z)) 2094 PNG_FIXED_EXPORT(134, png_uint_32, png_get_cHRM_fixed, 2095 (png_const_structrp png_ptr, png_const_inforp info_ptr, 2096 png_fixed_point *int_white_x, png_fixed_point *int_white_y, 2097 png_fixed_point *int_red_x, png_fixed_point *int_red_y, 2098 png_fixed_point *int_green_x, png_fixed_point *int_green_y, 2099 png_fixed_point *int_blue_x, png_fixed_point *int_blue_y)) 2100 PNG_FIXED_EXPORT(231, png_uint_32, png_get_cHRM_XYZ_fixed, 2101 (png_const_structrp png_ptr, png_const_inforp info_ptr, 2102 png_fixed_point *int_red_X, png_fixed_point *int_red_Y, 2103 png_fixed_point *int_red_Z, png_fixed_point *int_green_X, 2104 png_fixed_point *int_green_Y, png_fixed_point *int_green_Z, 2105 png_fixed_point *int_blue_X, png_fixed_point *int_blue_Y, 2106 png_fixed_point *int_blue_Z)) 2107 #endif 2108 2109 #ifdef PNG_cHRM_SUPPORTED 2110 PNG_FP_EXPORT(135, void, png_set_cHRM, (png_const_structrp png_ptr, 2111 png_inforp info_ptr, 2112 double white_x, double white_y, double red_x, double red_y, double green_x, 2113 double green_y, double blue_x, double blue_y)) 2114 PNG_FP_EXPORT(232, void, png_set_cHRM_XYZ, (png_const_structrp png_ptr, 2115 png_inforp info_ptr, double red_X, double red_Y, double red_Z, 2116 double green_X, double green_Y, double green_Z, double blue_X, 2117 double blue_Y, double blue_Z)) 2118 PNG_FIXED_EXPORT(136, void, png_set_cHRM_fixed, (png_const_structrp png_ptr, 2119 png_inforp info_ptr, png_fixed_point int_white_x, 2120 png_fixed_point int_white_y, png_fixed_point int_red_x, 2121 png_fixed_point int_red_y, png_fixed_point int_green_x, 2122 png_fixed_point int_green_y, png_fixed_point int_blue_x, 2123 png_fixed_point int_blue_y)) 2124 PNG_FIXED_EXPORT(233, void, png_set_cHRM_XYZ_fixed, (png_const_structrp png_ptr, 2125 png_inforp info_ptr, png_fixed_point int_red_X, png_fixed_point int_red_Y, 2126 png_fixed_point int_red_Z, png_fixed_point int_green_X, 2127 png_fixed_point int_green_Y, png_fixed_point int_green_Z, 2128 png_fixed_point int_blue_X, png_fixed_point int_blue_Y, 2129 png_fixed_point int_blue_Z)) 2130 #endif 2131 2132 #ifdef PNG_gAMA_SUPPORTED 2133 PNG_FP_EXPORT(137, png_uint_32, png_get_gAMA, (png_const_structrp png_ptr, 2134 png_const_inforp info_ptr, double *file_gamma)) 2135 PNG_FIXED_EXPORT(138, png_uint_32, png_get_gAMA_fixed, 2136 (png_const_structrp png_ptr, png_const_inforp info_ptr, 2137 png_fixed_point *int_file_gamma)) 2138 #endif 2139 2140 #ifdef PNG_gAMA_SUPPORTED 2141 PNG_FP_EXPORT(139, void, png_set_gAMA, (png_const_structrp png_ptr, 2142 png_inforp info_ptr, double file_gamma)) 2143 PNG_FIXED_EXPORT(140, void, png_set_gAMA_fixed, (png_const_structrp png_ptr, 2144 png_inforp info_ptr, png_fixed_point int_file_gamma)) 2145 #endif 2146 2147 #ifdef PNG_hIST_SUPPORTED 2148 PNG_EXPORT(141, png_uint_32, png_get_hIST, (png_const_structrp png_ptr, 2149 png_inforp info_ptr, png_uint_16p *hist)); 2150 #endif 2151 2152 #ifdef PNG_hIST_SUPPORTED 2153 PNG_EXPORT(142, void, png_set_hIST, (png_const_structrp png_ptr, 2154 png_inforp info_ptr, png_const_uint_16p hist)); 2155 #endif 2156 2157 PNG_EXPORT(143, png_uint_32, png_get_IHDR, (png_const_structrp png_ptr, 2158 png_const_inforp info_ptr, png_uint_32 *width, png_uint_32 *height, 2159 int *bit_depth, int *color_type, int *interlace_method, 2160 int *compression_method, int *filter_method)); 2161 2162 PNG_EXPORT(144, void, png_set_IHDR, (png_const_structrp png_ptr, 2163 png_inforp info_ptr, png_uint_32 width, png_uint_32 height, int bit_depth, 2164 int color_type, int interlace_method, int compression_method, 2165 int filter_method)); 2166 2167 #ifdef PNG_oFFs_SUPPORTED 2168 PNG_EXPORT(145, png_uint_32, png_get_oFFs, (png_const_structrp png_ptr, 2169 png_const_inforp info_ptr, png_int_32 *offset_x, png_int_32 *offset_y, 2170 int *unit_type)); 2171 #endif 2172 2173 #ifdef PNG_oFFs_SUPPORTED 2174 PNG_EXPORT(146, void, png_set_oFFs, (png_const_structrp png_ptr, 2175 png_inforp info_ptr, png_int_32 offset_x, png_int_32 offset_y, 2176 int unit_type)); 2177 #endif 2178 2179 #ifdef PNG_pCAL_SUPPORTED 2180 PNG_EXPORT(147, png_uint_32, png_get_pCAL, (png_const_structrp png_ptr, 2181 png_inforp info_ptr, png_charp *purpose, png_int_32 *X0, 2182 png_int_32 *X1, int *type, int *nparams, png_charp *units, 2183 png_charpp *params)); 2184 #endif 2185 2186 #ifdef PNG_pCAL_SUPPORTED 2187 PNG_EXPORT(148, void, png_set_pCAL, (png_const_structrp png_ptr, 2188 png_inforp info_ptr, png_const_charp purpose, png_int_32 X0, png_int_32 X1, 2189 int type, int nparams, png_const_charp units, png_charpp params)); 2190 #endif 2191 2192 #ifdef PNG_pHYs_SUPPORTED 2193 PNG_EXPORT(149, png_uint_32, png_get_pHYs, (png_const_structrp png_ptr, 2194 png_const_inforp info_ptr, png_uint_32 *res_x, png_uint_32 *res_y, 2195 int *unit_type)); 2196 #endif 2197 2198 #ifdef PNG_pHYs_SUPPORTED 2199 PNG_EXPORT(150, void, png_set_pHYs, (png_const_structrp png_ptr, 2200 png_inforp info_ptr, png_uint_32 res_x, png_uint_32 res_y, int unit_type)); 2201 #endif 2202 2203 PNG_EXPORT(151, png_uint_32, png_get_PLTE, (png_const_structrp png_ptr, 2204 png_inforp info_ptr, png_colorp *palette, int *num_palette)); 2205 2206 PNG_EXPORT(152, void, png_set_PLTE, (png_structrp png_ptr, 2207 png_inforp info_ptr, png_const_colorp palette, int num_palette)); 2208 2209 #ifdef PNG_sBIT_SUPPORTED 2210 PNG_EXPORT(153, png_uint_32, png_get_sBIT, (png_const_structrp png_ptr, 2211 png_inforp info_ptr, png_color_8p *sig_bit)); 2212 #endif 2213 2214 #ifdef PNG_sBIT_SUPPORTED 2215 PNG_EXPORT(154, void, png_set_sBIT, (png_const_structrp png_ptr, 2216 png_inforp info_ptr, png_const_color_8p sig_bit)); 2217 #endif 2218 2219 #ifdef PNG_sRGB_SUPPORTED 2220 PNG_EXPORT(155, png_uint_32, png_get_sRGB, (png_const_structrp png_ptr, 2221 png_const_inforp info_ptr, int *file_srgb_intent)); 2222 #endif 2223 2224 #ifdef PNG_sRGB_SUPPORTED 2225 PNG_EXPORT(156, void, png_set_sRGB, (png_const_structrp png_ptr, 2226 png_inforp info_ptr, int srgb_intent)); 2227 PNG_EXPORT(157, void, png_set_sRGB_gAMA_and_cHRM, (png_const_structrp png_ptr, 2228 png_inforp info_ptr, int srgb_intent)); 2229 #endif 2230 2231 #ifdef PNG_iCCP_SUPPORTED 2232 PNG_EXPORT(158, png_uint_32, png_get_iCCP, (png_const_structrp png_ptr, 2233 png_inforp info_ptr, png_charpp name, int *compression_type, 2234 png_bytepp profile, png_uint_32 *proflen)); 2235 #endif 2236 2237 #ifdef PNG_iCCP_SUPPORTED 2238 PNG_EXPORT(159, void, png_set_iCCP, (png_const_structrp png_ptr, 2239 png_inforp info_ptr, png_const_charp name, int compression_type, 2240 png_const_bytep profile, png_uint_32 proflen)); 2241 #endif 2242 2243 #ifdef PNG_sPLT_SUPPORTED 2244 PNG_EXPORT(160, int, png_get_sPLT, (png_const_structrp png_ptr, 2245 png_inforp info_ptr, png_sPLT_tpp entries)); 2246 #endif 2247 2248 #ifdef PNG_sPLT_SUPPORTED 2249 PNG_EXPORT(161, void, png_set_sPLT, (png_const_structrp png_ptr, 2250 png_inforp info_ptr, png_const_sPLT_tp entries, int nentries)); 2251 #endif 2252 2253 #ifdef PNG_TEXT_SUPPORTED 2254 /* png_get_text also returns the number of text chunks in *num_text */ 2255 PNG_EXPORT(162, int, png_get_text, (png_const_structrp png_ptr, 2256 png_inforp info_ptr, png_textp *text_ptr, int *num_text)); 2257 #endif 2258 2259 /* Note while png_set_text() will accept a structure whose text, 2260 * language, and translated keywords are NULL pointers, the structure 2261 * returned by png_get_text will always contain regular 2262 * zero-terminated C strings. They might be empty strings but 2263 * they will never be NULL pointers. 2264 */ 2265 2266 #ifdef PNG_TEXT_SUPPORTED 2267 PNG_EXPORT(163, void, png_set_text, (png_const_structrp png_ptr, 2268 png_inforp info_ptr, png_const_textp text_ptr, int num_text)); 2269 #endif 2270 2271 #ifdef PNG_tIME_SUPPORTED 2272 PNG_EXPORT(164, png_uint_32, png_get_tIME, (png_const_structrp png_ptr, 2273 png_inforp info_ptr, png_timep *mod_time)); 2274 #endif 2275 2276 #ifdef PNG_tIME_SUPPORTED 2277 PNG_EXPORT(165, void, png_set_tIME, (png_const_structrp png_ptr, 2278 png_inforp info_ptr, png_const_timep mod_time)); 2279 #endif 2280 2281 #ifdef PNG_tRNS_SUPPORTED 2282 PNG_EXPORT(166, png_uint_32, png_get_tRNS, (png_const_structrp png_ptr, 2283 png_inforp info_ptr, png_bytep *trans_alpha, int *num_trans, 2284 png_color_16p *trans_color)); 2285 #endif 2286 2287 #ifdef PNG_tRNS_SUPPORTED 2288 PNG_EXPORT(167, void, png_set_tRNS, (png_structrp png_ptr, 2289 png_inforp info_ptr, png_const_bytep trans_alpha, int num_trans, 2290 png_const_color_16p trans_color)); 2291 #endif 2292 2293 #ifdef PNG_sCAL_SUPPORTED 2294 PNG_FP_EXPORT(168, png_uint_32, png_get_sCAL, (png_const_structrp png_ptr, 2295 png_const_inforp info_ptr, int *unit, double *width, double *height)) 2296 #if defined(PNG_FLOATING_ARITHMETIC_SUPPORTED) || \ 2297 defined(PNG_FLOATING_POINT_SUPPORTED) 2298 /* NOTE: this API is currently implemented using floating point arithmetic, 2299 * consequently it can only be used on systems with floating point support. 2300 * In any case the range of values supported by png_fixed_point is small and it 2301 * is highly recommended that png_get_sCAL_s be used instead. 2302 */ 2303 PNG_FIXED_EXPORT(214, png_uint_32, png_get_sCAL_fixed, 2304 (png_const_structrp png_ptr, png_const_inforp info_ptr, int *unit, 2305 png_fixed_point *width, png_fixed_point *height)) 2306 #endif 2307 PNG_EXPORT(169, png_uint_32, png_get_sCAL_s, 2308 (png_const_structrp png_ptr, png_const_inforp info_ptr, int *unit, 2309 png_charpp swidth, png_charpp sheight)); 2310 2311 PNG_FP_EXPORT(170, void, png_set_sCAL, (png_const_structrp png_ptr, 2312 png_inforp info_ptr, int unit, double width, double height)) 2313 PNG_FIXED_EXPORT(213, void, png_set_sCAL_fixed, (png_const_structrp png_ptr, 2314 png_inforp info_ptr, int unit, png_fixed_point width, 2315 png_fixed_point height)) 2316 PNG_EXPORT(171, void, png_set_sCAL_s, (png_const_structrp png_ptr, 2317 png_inforp info_ptr, int unit, 2318 png_const_charp swidth, png_const_charp sheight)); 2319 #endif /* PNG_sCAL_SUPPORTED */ 2320 2321 #ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED 2322 /* Provide the default handling for all unknown chunks or, optionally, for 2323 * specific unknown chunks. 2324 * 2325 * NOTE: prior to 1.6.0 the handling specified for particular chunks on read was 2326 * ignored and the default was used, the per-chunk setting only had an effect on 2327 * write. If you wish to have chunk-specific handling on read in code that must 2328 * work on earlier versions you must use a user chunk callback to specify the 2329 * desired handling (keep or discard.) 2330 * 2331 * The 'keep' parameter is a PNG_HANDLE_CHUNK_ value as listed below. The 2332 * parameter is interpreted as follows: 2333 * 2334 * READ: 2335 * PNG_HANDLE_CHUNK_AS_DEFAULT: 2336 * Known chunks: do normal libpng processing, do not keep the chunk (but 2337 * see the comments below about PNG_HANDLE_AS_UNKNOWN_SUPPORTED) 2338 * Unknown chunks: for a specific chunk use the global default, when used 2339 * as the default discard the chunk data. 2340 * PNG_HANDLE_CHUNK_NEVER: 2341 * Discard the chunk data. 2342 * PNG_HANDLE_CHUNK_IF_SAFE: 2343 * Keep the chunk data if the chunk is not critical else raise a chunk 2344 * error. 2345 * PNG_HANDLE_CHUNK_ALWAYS: 2346 * Keep the chunk data. 2347 * 2348 * If the chunk data is saved it can be retrieved using png_get_unknown_chunks, 2349 * below. Notice that specifying "AS_DEFAULT" as a global default is equivalent 2350 * to specifying "NEVER", however when "AS_DEFAULT" is used for specific chunks 2351 * it simply resets the behavior to the libpng default. 2352 * 2353 * INTERACTION WTIH USER CHUNK CALLBACKS: 2354 * The per-chunk handling is always used when there is a png_user_chunk_ptr 2355 * callback and the callback returns 0; the chunk is then always stored *unless* 2356 * it is critical and the per-chunk setting is other than ALWAYS. Notice that 2357 * the global default is *not* used in this case. (In effect the per-chunk 2358 * value is incremented to at least IF_SAFE.) 2359 * 2360 * IMPORTANT NOTE: this behavior will change in libpng 1.7 - the global and 2361 * per-chunk defaults will be honored. If you want to preserve the current 2362 * behavior when your callback returns 0 you must set PNG_HANDLE_CHUNK_IF_SAFE 2363 * as the default - if you don't do this libpng 1.6 will issue a warning. 2364 * 2365 * If you want unhandled unknown chunks to be discarded in libpng 1.6 and 2366 * earlier simply return '1' (handled). 2367 * 2368 * PNG_HANDLE_AS_UNKNOWN_SUPPORTED: 2369 * If this is *not* set known chunks will always be handled by libpng and 2370 * will never be stored in the unknown chunk list. Known chunks listed to 2371 * png_set_keep_unknown_chunks will have no effect. If it is set then known 2372 * chunks listed with a keep other than AS_DEFAULT will *never* be processed 2373 * by libpng, in addition critical chunks must either be processed by the 2374 * callback or saved. 2375 * 2376 * The IHDR and IEND chunks must not be listed. Because this turns off the 2377 * default handling for chunks that would otherwise be recognized the 2378 * behavior of libpng transformations may well become incorrect! 2379 * 2380 * WRITE: 2381 * When writing chunks the options only apply to the chunks specified by 2382 * png_set_unknown_chunks (below), libpng will *always* write known chunks 2383 * required by png_set_ calls and will always write the core critical chunks 2384 * (as required for PLTE). 2385 * 2386 * Each chunk in the png_set_unknown_chunks list is looked up in the 2387 * png_set_keep_unknown_chunks list to find the keep setting, this is then 2388 * interpreted as follows: 2389 * 2390 * PNG_HANDLE_CHUNK_AS_DEFAULT: 2391 * Write safe-to-copy chunks and write other chunks if the global 2392 * default is set to _ALWAYS, otherwise don't write this chunk. 2393 * PNG_HANDLE_CHUNK_NEVER: 2394 * Do not write the chunk. 2395 * PNG_HANDLE_CHUNK_IF_SAFE: 2396 * Write the chunk if it is safe-to-copy, otherwise do not write it. 2397 * PNG_HANDLE_CHUNK_ALWAYS: 2398 * Write the chunk. 2399 * 2400 * Note that the default behavior is effectively the opposite of the read case - 2401 * in read unknown chunks are not stored by default, in write they are written 2402 * by default. Also the behavior of PNG_HANDLE_CHUNK_IF_SAFE is very different 2403 * - on write the safe-to-copy bit is checked, on read the critical bit is 2404 * checked and on read if the chunk is critical an error will be raised. 2405 * 2406 * num_chunks: 2407 * =========== 2408 * If num_chunks is positive, then the "keep" parameter specifies the manner 2409 * for handling only those chunks appearing in the chunk_list array, 2410 * otherwise the chunk list array is ignored. 2411 * 2412 * If num_chunks is 0 the "keep" parameter specifies the default behavior for 2413 * unknown chunks, as described above. 2414 * 2415 * If num_chunks is negative, then the "keep" parameter specifies the manner 2416 * for handling all unknown chunks plus all chunks recognized by libpng 2417 * except for the IHDR, PLTE, tRNS, IDAT, and IEND chunks (which continue to 2418 * be processed by libpng. 2419 */ 2420 PNG_EXPORT(172, void, png_set_keep_unknown_chunks, (png_structrp png_ptr, 2421 int keep, png_const_bytep chunk_list, int num_chunks)); 2422 2423 /* The "keep" PNG_HANDLE_CHUNK_ parameter for the specified chunk is returned; 2424 * the result is therefore true (non-zero) if special handling is required, 2425 * false for the default handling. 2426 */ 2427 PNG_EXPORT(173, int, png_handle_as_unknown, (png_const_structrp png_ptr, 2428 png_const_bytep chunk_name)); 2429 #endif 2430 2431 #ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED 2432 PNG_EXPORT(174, void, png_set_unknown_chunks, (png_const_structrp png_ptr, 2433 png_inforp info_ptr, png_const_unknown_chunkp unknowns, 2434 int num_unknowns)); 2435 /* NOTE: prior to 1.6.0 this routine set the 'location' field of the added 2436 * unknowns to the location currently stored in the png_struct. This is 2437 * invariably the wrong value on write. To fix this call the following API 2438 * for each chunk in the list with the correct location. If you know your 2439 * code won't be compiled on earlier versions you can rely on 2440 * png_set_unknown_chunks(write-ptr, png_get_unknown_chunks(read-ptr)) doing 2441 * the correct thing. 2442 */ 2443 2444 PNG_EXPORT(175, void, png_set_unknown_chunk_location, 2445 (png_const_structrp png_ptr, png_inforp info_ptr, int chunk, int location)); 2446 2447 PNG_EXPORT(176, int, png_get_unknown_chunks, (png_const_structrp png_ptr, 2448 png_inforp info_ptr, png_unknown_chunkpp entries)); 2449 #endif 2450 2451 /* Png_free_data() will turn off the "valid" flag for anything it frees. 2452 * If you need to turn it off for a chunk that your application has freed, 2453 * you can use png_set_invalid(png_ptr, info_ptr, PNG_INFO_CHNK); 2454 */ 2455 PNG_EXPORT(177, void, png_set_invalid, (png_const_structrp png_ptr, 2456 png_inforp info_ptr, int mask)); 2457 2458 #ifdef PNG_INFO_IMAGE_SUPPORTED 2459 /* The "params" pointer is currently not used and is for future expansion. */ 2460 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED 2461 PNG_EXPORT(178, void, png_read_png, (png_structrp png_ptr, png_inforp info_ptr, 2462 int transforms, png_voidp params)); 2463 #endif 2464 #ifdef PNG_WRITE_SUPPORTED 2465 PNG_EXPORT(179, void, png_write_png, (png_structrp png_ptr, png_inforp info_ptr, 2466 int transforms, png_voidp params)); 2467 #endif 2468 #endif 2469 2470 PNG_EXPORT(180, png_const_charp, png_get_copyright, 2471 (png_const_structrp png_ptr)); 2472 PNG_EXPORT(181, png_const_charp, png_get_header_ver, 2473 (png_const_structrp png_ptr)); 2474 PNG_EXPORT(182, png_const_charp, png_get_header_version, 2475 (png_const_structrp png_ptr)); 2476 PNG_EXPORT(183, png_const_charp, png_get_libpng_ver, 2477 (png_const_structrp png_ptr)); 2478 2479 #ifdef PNG_MNG_FEATURES_SUPPORTED 2480 PNG_EXPORT(184, png_uint_32, png_permit_mng_features, (png_structrp png_ptr, 2481 png_uint_32 mng_features_permitted)); 2482 #endif 2483 2484 /* For use in png_set_keep_unknown, added to version 1.2.6 */ 2485 #define PNG_HANDLE_CHUNK_AS_DEFAULT 0 2486 #define PNG_HANDLE_CHUNK_NEVER 1 2487 #define PNG_HANDLE_CHUNK_IF_SAFE 2 2488 #define PNG_HANDLE_CHUNK_ALWAYS 3 2489 #define PNG_HANDLE_CHUNK_LAST 4 2490 2491 /* Strip the prepended error numbers ("#nnn ") from error and warning 2492 * messages before passing them to the error or warning handler. 2493 */ 2494 #ifdef PNG_ERROR_NUMBERS_SUPPORTED 2495 PNG_EXPORT(185, void, png_set_strip_error_numbers, (png_structrp png_ptr, 2496 png_uint_32 strip_mode)); 2497 #endif 2498 2499 /* Added in libpng-1.2.6 */ 2500 #ifdef PNG_SET_USER_LIMITS_SUPPORTED 2501 PNG_EXPORT(186, void, png_set_user_limits, (png_structrp png_ptr, 2502 png_uint_32 user_width_max, png_uint_32 user_height_max)); 2503 PNG_EXPORT(187, png_uint_32, png_get_user_width_max, 2504 (png_const_structrp png_ptr)); 2505 PNG_EXPORT(188, png_uint_32, png_get_user_height_max, 2506 (png_const_structrp png_ptr)); 2507 /* Added in libpng-1.4.0 */ 2508 PNG_EXPORT(189, void, png_set_chunk_cache_max, (png_structrp png_ptr, 2509 png_uint_32 user_chunk_cache_max)); 2510 PNG_EXPORT(190, png_uint_32, png_get_chunk_cache_max, 2511 (png_const_structrp png_ptr)); 2512 /* Added in libpng-1.4.1 */ 2513 PNG_EXPORT(191, void, png_set_chunk_malloc_max, (png_structrp png_ptr, 2514 png_alloc_size_t user_chunk_cache_max)); 2515 PNG_EXPORT(192, png_alloc_size_t, png_get_chunk_malloc_max, 2516 (png_const_structrp png_ptr)); 2517 #endif 2518 2519 #if defined(PNG_INCH_CONVERSIONS_SUPPORTED) 2520 PNG_EXPORT(193, png_uint_32, png_get_pixels_per_inch, 2521 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 2522 2523 PNG_EXPORT(194, png_uint_32, png_get_x_pixels_per_inch, 2524 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 2525 2526 PNG_EXPORT(195, png_uint_32, png_get_y_pixels_per_inch, 2527 (png_const_structrp png_ptr, png_const_inforp info_ptr)); 2528 2529 PNG_FP_EXPORT(196, float, png_get_x_offset_inches, 2530 (png_const_structrp png_ptr, png_const_inforp info_ptr)) 2531 #ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */ 2532 PNG_FIXED_EXPORT(211, png_fixed_point, png_get_x_offset_inches_fixed, 2533 (png_const_structrp png_ptr, png_const_inforp info_ptr)) 2534 #endif 2535 2536 PNG_FP_EXPORT(197, float, png_get_y_offset_inches, (png_const_structrp png_ptr, 2537 png_const_inforp info_ptr)) 2538 #ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */ 2539 PNG_FIXED_EXPORT(212, png_fixed_point, png_get_y_offset_inches_fixed, 2540 (png_const_structrp png_ptr, png_const_inforp info_ptr)) 2541 #endif 2542 2543 # ifdef PNG_pHYs_SUPPORTED 2544 PNG_EXPORT(198, png_uint_32, png_get_pHYs_dpi, (png_const_structrp png_ptr, 2545 png_const_inforp info_ptr, png_uint_32 *res_x, png_uint_32 *res_y, 2546 int *unit_type)); 2547 # endif /* PNG_pHYs_SUPPORTED */ 2548 #endif /* PNG_INCH_CONVERSIONS_SUPPORTED */ 2549 2550 /* Added in libpng-1.4.0 */ 2551 #ifdef PNG_IO_STATE_SUPPORTED 2552 PNG_EXPORT(199, png_uint_32, png_get_io_state, (png_const_structrp png_ptr)); 2553 2554 /* Removed from libpng 1.6; use png_get_io_chunk_type. */ 2555 PNG_REMOVED(200, png_const_bytep, png_get_io_chunk_name, (png_structrp png_ptr), 2556 PNG_DEPRECATED) 2557 2558 PNG_EXPORT(216, png_uint_32, png_get_io_chunk_type, 2559 (png_const_structrp png_ptr)); 2560 2561 /* The flags returned by png_get_io_state() are the following: */ 2562 # define PNG_IO_NONE 0x0000 /* no I/O at this moment */ 2563 # define PNG_IO_READING 0x0001 /* currently reading */ 2564 # define PNG_IO_WRITING 0x0002 /* currently writing */ 2565 # define PNG_IO_SIGNATURE 0x0010 /* currently at the file signature */ 2566 # define PNG_IO_CHUNK_HDR 0x0020 /* currently at the chunk header */ 2567 # define PNG_IO_CHUNK_DATA 0x0040 /* currently at the chunk data */ 2568 # define PNG_IO_CHUNK_CRC 0x0080 /* currently at the chunk crc */ 2569 # define PNG_IO_MASK_OP 0x000f /* current operation: reading/writing */ 2570 # define PNG_IO_MASK_LOC 0x00f0 /* current location: sig/hdr/data/crc */ 2571 #endif /* ?PNG_IO_STATE_SUPPORTED */ 2572 2573 /* Interlace support. The following macros are always defined so that if 2574 * libpng interlace handling is turned off the macros may be used to handle 2575 * interlaced images within the application. 2576 */ 2577 #define PNG_INTERLACE_ADAM7_PASSES 7 2578 2579 /* Two macros to return the first row and first column of the original, 2580 * full, image which appears in a given pass. 'pass' is in the range 0 2581 * to 6 and the result is in the range 0 to 7. 2582 */ 2583 #define PNG_PASS_START_ROW(pass) (((1&~(pass))<<(3-((pass)>>1)))&7) 2584 #define PNG_PASS_START_COL(pass) (((1& (pass))<<(3-(((pass)+1)>>1)))&7) 2585 2586 /* A macro to return the offset between pixels in the output row for a pair of 2587 * pixels in the input - effectively the inverse of the 'COL_SHIFT' macro that 2588 * follows. Note that ROW_OFFSET is the offset from one row to the next whereas 2589 * COL_OFFSET is from one column to the next, within a row. 2590 */ 2591 #define PNG_PASS_ROW_OFFSET(pass) ((pass)>2?(8>>(((pass)-1)>>1)):8) 2592 #define PNG_PASS_COL_OFFSET(pass) (1<<((7-(pass))>>1)) 2593 2594 /* Two macros to help evaluate the number of rows or columns in each 2595 * pass. This is expressed as a shift - effectively log2 of the number or 2596 * rows or columns in each 8x8 tile of the original image. 2597 */ 2598 #define PNG_PASS_ROW_SHIFT(pass) ((pass)>2?(8-(pass))>>1:3) 2599 #define PNG_PASS_COL_SHIFT(pass) ((pass)>1?(7-(pass))>>1:3) 2600 2601 /* Hence two macros to determine the number of rows or columns in a given 2602 * pass of an image given its height or width. In fact these macros may 2603 * return non-zero even though the sub-image is empty, because the other 2604 * dimension may be empty for a small image. 2605 */ 2606 #define PNG_PASS_ROWS(height, pass) (((height)+(((1<<PNG_PASS_ROW_SHIFT(pass))\ 2607 -1)-PNG_PASS_START_ROW(pass)))>>PNG_PASS_ROW_SHIFT(pass)) 2608 #define PNG_PASS_COLS(width, pass) (((width)+(((1<<PNG_PASS_COL_SHIFT(pass))\ 2609 -1)-PNG_PASS_START_COL(pass)))>>PNG_PASS_COL_SHIFT(pass)) 2610 2611 /* For the reader row callbacks (both progressive and sequential) it is 2612 * necessary to find the row in the output image given a row in an interlaced 2613 * image, so two more macros: 2614 */ 2615 #define PNG_ROW_FROM_PASS_ROW(y_in, pass) \ 2616 (((y_in)<<PNG_PASS_ROW_SHIFT(pass))+PNG_PASS_START_ROW(pass)) 2617 #define PNG_COL_FROM_PASS_COL(x_in, pass) \ 2618 (((x_in)<<PNG_PASS_COL_SHIFT(pass))+PNG_PASS_START_COL(pass)) 2619 2620 /* Two macros which return a boolean (0 or 1) saying whether the given row 2621 * or column is in a particular pass. These use a common utility macro that 2622 * returns a mask for a given pass - the offset 'off' selects the row or 2623 * column version. The mask has the appropriate bit set for each column in 2624 * the tile. 2625 */ 2626 #define PNG_PASS_MASK(pass,off) ( \ 2627 ((0x110145AF>>(((7-(off))-(pass))<<2)) & 0xF) | \ 2628 ((0x01145AF0>>(((7-(off))-(pass))<<2)) & 0xF0)) 2629 2630 #define PNG_ROW_IN_INTERLACE_PASS(y, pass) \ 2631 ((PNG_PASS_MASK(pass,0) >> ((y)&7)) & 1) 2632 #define PNG_COL_IN_INTERLACE_PASS(x, pass) \ 2633 ((PNG_PASS_MASK(pass,1) >> ((x)&7)) & 1) 2634 2635 #ifdef PNG_READ_COMPOSITE_NODIV_SUPPORTED 2636 /* With these routines we avoid an integer divide, which will be slower on 2637 * most machines. However, it does take more operations than the corresponding 2638 * divide method, so it may be slower on a few RISC systems. There are two 2639 * shifts (by 8 or 16 bits) and an addition, versus a single integer divide. 2640 * 2641 * Note that the rounding factors are NOT supposed to be the same! 128 and 2642 * 32768 are correct for the NODIV code; 127 and 32767 are correct for the 2643 * standard method. 2644 * 2645 * [Optimized code by Greg Roelofs and Mark Adler...blame us for bugs. :-) ] 2646 */ 2647 2648 /* fg and bg should be in `gamma 1.0' space; alpha is the opacity */ 2649 2650 # define png_composite(composite, fg, alpha, bg) \ 2651 { png_uint_16 temp = (png_uint_16)((png_uint_16)(fg) \ 2652 * (png_uint_16)(alpha) \ 2653 + (png_uint_16)(bg)*(png_uint_16)(255 \ 2654 - (png_uint_16)(alpha)) + 128); \ 2655 (composite) = (png_byte)((temp + (temp >> 8)) >> 8); } 2656 2657 # define png_composite_16(composite, fg, alpha, bg) \ 2658 { png_uint_32 temp = (png_uint_32)((png_uint_32)(fg) \ 2659 * (png_uint_32)(alpha) \ 2660 + (png_uint_32)(bg)*(65535 \ 2661 - (png_uint_32)(alpha)) + 32768); \ 2662 (composite) = (png_uint_16)((temp + (temp >> 16)) >> 16); } 2663 2664 #else /* Standard method using integer division */ 2665 2666 # define png_composite(composite, fg, alpha, bg) \ 2667 (composite) = (png_byte)(((png_uint_16)(fg) * (png_uint_16)(alpha) + \ 2668 (png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) + \ 2669 127) / 255) 2670 2671 # define png_composite_16(composite, fg, alpha, bg) \ 2672 (composite) = (png_uint_16)(((png_uint_32)(fg) * (png_uint_32)(alpha) + \ 2673 (png_uint_32)(bg)*(png_uint_32)(65535 - (png_uint_32)(alpha)) + \ 2674 32767) / 65535) 2675 #endif /* PNG_READ_COMPOSITE_NODIV_SUPPORTED */ 2676 2677 #ifdef PNG_READ_INT_FUNCTIONS_SUPPORTED 2678 PNG_EXPORT(201, png_uint_32, png_get_uint_32, (png_const_bytep buf)); 2679 PNG_EXPORT(202, png_uint_16, png_get_uint_16, (png_const_bytep buf)); 2680 PNG_EXPORT(203, png_int_32, png_get_int_32, (png_const_bytep buf)); 2681 #endif 2682 2683 PNG_EXPORT(204, png_uint_32, png_get_uint_31, (png_const_structrp png_ptr, 2684 png_const_bytep buf)); 2685 /* No png_get_int_16 -- may be added if there's a real need for it. */ 2686 2687 /* Place a 32-bit number into a buffer in PNG byte order (big-endian). */ 2688 #ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED 2689 PNG_EXPORT(205, void, png_save_uint_32, (png_bytep buf, png_uint_32 i)); 2690 #endif 2691 #ifdef PNG_SAVE_INT_32_SUPPORTED 2692 PNG_EXPORT(206, void, png_save_int_32, (png_bytep buf, png_int_32 i)); 2693 #endif 2694 2695 /* Place a 16-bit number into a buffer in PNG byte order. 2696 * The parameter is declared unsigned int, not png_uint_16, 2697 * just to avoid potential problems on pre-ANSI C compilers. 2698 */ 2699 #ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED 2700 PNG_EXPORT(207, void, png_save_uint_16, (png_bytep buf, unsigned int i)); 2701 /* No png_save_int_16 -- may be added if there's a real need for it. */ 2702 #endif 2703 2704 #ifdef PNG_USE_READ_MACROS 2705 /* Inline macros to do direct reads of bytes from the input buffer. 2706 * The png_get_int_32() routine assumes we are using two's complement 2707 * format for negative values, which is almost certainly true. 2708 */ 2709 # define PNG_get_uint_32(buf) \ 2710 (((png_uint_32)(*(buf)) << 24) + \ 2711 ((png_uint_32)(*((buf) + 1)) << 16) + \ 2712 ((png_uint_32)(*((buf) + 2)) << 8) + \ 2713 ((png_uint_32)(*((buf) + 3)))) 2714 2715 /* From libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the 2716 * function) incorrectly returned a value of type png_uint_32. 2717 */ 2718 # define PNG_get_uint_16(buf) \ 2719 ((png_uint_16) \ 2720 (((unsigned int)(*(buf)) << 8) + \ 2721 ((unsigned int)(*((buf) + 1))))) 2722 2723 # define PNG_get_int_32(buf) \ 2724 ((png_int_32)((*(buf) & 0x80) \ 2725 ? -((png_int_32)((png_get_uint_32(buf) ^ 0xffffffffL) + 1)) \ 2726 : (png_int_32)png_get_uint_32(buf))) 2727 2728 /* If PNG_PREFIX is defined the same thing as below happens in pnglibconf.h, 2729 * but defining a macro name prefixed with PNG_PREFIX. 2730 */ 2731 # ifndef PNG_PREFIX 2732 # define png_get_uint_32(buf) PNG_get_uint_32(buf) 2733 # define png_get_uint_16(buf) PNG_get_uint_16(buf) 2734 # define png_get_int_32(buf) PNG_get_int_32(buf) 2735 # endif 2736 #else 2737 # ifdef PNG_PREFIX 2738 /* No macros; revert to the (redefined) function */ 2739 # define PNG_get_uint_32 (png_get_uint_32) 2740 # define PNG_get_uint_16 (png_get_uint_16) 2741 # define PNG_get_int_32 (png_get_int_32) 2742 # endif 2743 #endif 2744 2745 /******************************************************************************* 2746 * SIMPLIFIED API 2747 ******************************************************************************* 2748 * 2749 * Please read the documentation in libpng-manual.txt (TODO: write said 2750 * documentation) if you don't understand what follows. 2751 * 2752 * The simplified API hides the details of both libpng and the PNG file format 2753 * itself. It allows PNG files to be read into a very limited number of 2754 * in-memory bitmap formats or to be written from the same formats. If these 2755 * formats do not accomodate your needs then you can, and should, use the more 2756 * sophisticated APIs above - these support a wide variety of in-memory formats 2757 * and a wide variety of sophisticated transformations to those formats as well 2758 * as a wide variety of APIs to manipulate ancillary information. 2759 * 2760 * To read a PNG file using the simplified API: 2761 * 2762 * 1) Declare a 'png_image' structure (see below) on the stack and set the 2763 * version field to PNG_IMAGE_VERSION. 2764 * 2) Call the appropriate png_image_begin_read... function. 2765 * 3) Set the png_image 'format' member to the required sample format. 2766 * 4) Allocate a buffer for the image and, if required, the color-map. 2767 * 5) Call png_image_finish_read to read the image and, if required, the 2768 * color-map into your buffers. 2769 * 2770 * There are no restrictions on the format of the PNG input itself; all valid 2771 * color types, bit depths, and interlace methods are acceptable, and the 2772 * input image is transformed as necessary to the requested in-memory format 2773 * during the png_image_finish_read() step. The only caveat is that if you 2774 * request a color-mapped image from a PNG that is full-color or makes 2775 * complex use of an alpha channel the transformation is extremely lossy and the 2776 * result may look terrible. 2777 * 2778 * To write a PNG file using the simplified API: 2779 * 2780 * 1) Declare a 'png_image' structure on the stack and memset() it to all zero. 2781 * 2) Initialize the members of the structure that describe the image, setting 2782 * the 'format' member to the format of the image samples. 2783 * 3) Call the appropriate png_image_write... function with a pointer to the 2784 * image and, if necessary, the color-map to write the PNG data. 2785 * 2786 * png_image is a structure that describes the in-memory format of an image 2787 * when it is being read or defines the in-memory format of an image that you 2788 * need to write: 2789 */ 2790 #define PNG_IMAGE_VERSION 1 2791 2792 typedef struct png_control *png_controlp; 2793 typedef struct 2794 { 2795 png_controlp opaque; /* Initialize to NULL, free with png_image_free */ 2796 png_uint_32 version; /* Set to PNG_IMAGE_VERSION */ 2797 png_uint_32 width; /* Image width in pixels (columns) */ 2798 png_uint_32 height; /* Image height in pixels (rows) */ 2799 png_uint_32 format; /* Image format as defined below */ 2800 png_uint_32 flags; /* A bit mask containing informational flags */ 2801 png_uint_32 colormap_entries; 2802 /* Number of entries in the color-map */ 2803 2804 /* In the event of an error or warning the following field will be set to a 2805 * non-zero value and the 'message' field will contain a '\0' terminated 2806 * string with the libpng error or warning message. If both warnings and 2807 * an error were encountered, only the error is recorded. If there 2808 * are multiple warnings, only the first one is recorded. 2809 * 2810 * The upper 30 bits of this value are reserved, the low two bits contain 2811 * a value as follows: 2812 */ 2813 # define PNG_IMAGE_WARNING 1 2814 # define PNG_IMAGE_ERROR 2 2815 /* 2816 * The result is a two bit code such that a value more than 1 indicates 2817 * a failure in the API just called: 2818 * 2819 * 0 - no warning or error 2820 * 1 - warning 2821 * 2 - error 2822 * 3 - error preceded by warning 2823 */ 2824 # define PNG_IMAGE_FAILED(png_cntrl) ((((png_cntrl).warning_or_error)&0x03)>1) 2825 2826 png_uint_32 warning_or_error; 2827 2828 char message[64]; 2829 } png_image, *png_imagep; 2830 2831 /* The samples of the image have one to four channels whose components have 2832 * original values in the range 0 to 1.0: 2833 * 2834 * 1: A single gray or luminance channel (G). 2835 * 2: A gray/luminance channel and an alpha channel (GA). 2836 * 3: Three red, green, blue color channels (RGB). 2837 * 4: Three color channels and an alpha channel (RGBA). 2838 * 2839 * The components are encoded in one of two ways: 2840 * 2841 * a) As a small integer, value 0..255, contained in a single byte. For the 2842 * alpha channel the original value is simply value/255. For the color or 2843 * luminance channels the value is encoded according to the sRGB specification 2844 * and matches the 8-bit format expected by typical display devices. 2845 * 2846 * The color/gray channels are not scaled (pre-multiplied) by the alpha 2847 * channel and are suitable for passing to color management software. 2848 * 2849 * b) As a value in the range 0..65535, contained in a 2-byte integer. All 2850 * channels can be converted to the original value by dividing by 65535; all 2851 * channels are linear. Color channels use the RGB encoding (RGB end-points) of 2852 * the sRGB specification. This encoding is identified by the 2853 * PNG_FORMAT_FLAG_LINEAR flag below. 2854 * 2855 * When the simplified API needs to convert between sRGB and linear colorspaces, 2856 * the actual sRGB transfer curve defined in the sRGB specification (see the 2857 * article at http://en.wikipedia.org/wiki/SRGB) is used, not the gamma=1/2.2 2858 * approximation used elsewhere in libpng. 2859 * 2860 * When an alpha channel is present it is expected to denote pixel coverage 2861 * of the color or luminance channels and is returned as an associated alpha 2862 * channel: the color/gray channels are scaled (pre-multiplied) by the alpha 2863 * value. 2864 * 2865 * The samples are either contained directly in the image data, between 1 and 8 2866 * bytes per pixel according to the encoding, or are held in a color-map indexed 2867 * by bytes in the image data. In the case of a color-map the color-map entries 2868 * are individual samples, encoded as above, and the image data has one byte per 2869 * pixel to select the relevant sample from the color-map. 2870 */ 2871 2872 /* PNG_FORMAT_* 2873 * 2874 * #defines to be used in png_image::format. Each #define identifies a 2875 * particular layout of sample data and, if present, alpha values. There are 2876 * separate defines for each of the two component encodings. 2877 * 2878 * A format is built up using single bit flag values. All combinations are 2879 * valid. Formats can be built up from the flag values or you can use one of 2880 * the predefined values below. When testing formats always use the FORMAT_FLAG 2881 * macros to test for individual features - future versions of the library may 2882 * add new flags. 2883 * 2884 * When reading or writing color-mapped images the format should be set to the 2885 * format of the entries in the color-map then png_image_{read,write}_colormap 2886 * called to read or write the color-map and set the format correctly for the 2887 * image data. Do not set the PNG_FORMAT_FLAG_COLORMAP bit directly! 2888 * 2889 * NOTE: libpng can be built with particular features disabled, if you see 2890 * compiler errors because the definition of one of the following flags has been 2891 * compiled out it is because libpng does not have the required support. It is 2892 * possible, however, for the libpng configuration to enable the format on just 2893 * read or just write; in that case you may see an error at run time. You can 2894 * guard against this by checking for the definition of the appropriate 2895 * "_SUPPORTED" macro, one of: 2896 * 2897 * PNG_SIMPLIFIED_{READ,WRITE}_{BGR,AFIRST}_SUPPORTED 2898 */ 2899 #define PNG_FORMAT_FLAG_ALPHA 0x01U /* format with an alpha channel */ 2900 #define PNG_FORMAT_FLAG_COLOR 0x02U /* color format: otherwise grayscale */ 2901 #define PNG_FORMAT_FLAG_LINEAR 0x04U /* 2 byte channels else 1 byte */ 2902 #define PNG_FORMAT_FLAG_COLORMAP 0x08U /* image data is color-mapped */ 2903 2904 #ifdef PNG_FORMAT_BGR_SUPPORTED 2905 # define PNG_FORMAT_FLAG_BGR 0x10U /* BGR colors, else order is RGB */ 2906 #endif 2907 2908 #ifdef PNG_FORMAT_AFIRST_SUPPORTED 2909 # define PNG_FORMAT_FLAG_AFIRST 0x20U /* alpha channel comes first */ 2910 #endif 2911 2912 /* Commonly used formats have predefined macros. 2913 * 2914 * First the single byte (sRGB) formats: 2915 */ 2916 #define PNG_FORMAT_GRAY 0 2917 #define PNG_FORMAT_GA PNG_FORMAT_FLAG_ALPHA 2918 #define PNG_FORMAT_AG (PNG_FORMAT_GA|PNG_FORMAT_FLAG_AFIRST) 2919 #define PNG_FORMAT_RGB PNG_FORMAT_FLAG_COLOR 2920 #define PNG_FORMAT_BGR (PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_BGR) 2921 #define PNG_FORMAT_RGBA (PNG_FORMAT_RGB|PNG_FORMAT_FLAG_ALPHA) 2922 #define PNG_FORMAT_ARGB (PNG_FORMAT_RGBA|PNG_FORMAT_FLAG_AFIRST) 2923 #define PNG_FORMAT_BGRA (PNG_FORMAT_BGR|PNG_FORMAT_FLAG_ALPHA) 2924 #define PNG_FORMAT_ABGR (PNG_FORMAT_BGRA|PNG_FORMAT_FLAG_AFIRST) 2925 2926 /* Then the linear 2-byte formats. When naming these "Y" is used to 2927 * indicate a luminance (gray) channel. 2928 */ 2929 #define PNG_FORMAT_LINEAR_Y PNG_FORMAT_FLAG_LINEAR 2930 #define PNG_FORMAT_LINEAR_Y_ALPHA (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_ALPHA) 2931 #define PNG_FORMAT_LINEAR_RGB (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR) 2932 #define PNG_FORMAT_LINEAR_RGB_ALPHA \ 2933 (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_ALPHA) 2934 2935 /* With color-mapped formats the image data is one byte for each pixel, the byte 2936 * is an index into the color-map which is formatted as above. To obtain a 2937 * color-mapped format it is sufficient just to add the PNG_FOMAT_FLAG_COLORMAP 2938 * to one of the above definitions, or you can use one of the definitions below. 2939 */ 2940 #define PNG_FORMAT_RGB_COLORMAP (PNG_FORMAT_RGB|PNG_FORMAT_FLAG_COLORMAP) 2941 #define PNG_FORMAT_BGR_COLORMAP (PNG_FORMAT_BGR|PNG_FORMAT_FLAG_COLORMAP) 2942 #define PNG_FORMAT_RGBA_COLORMAP (PNG_FORMAT_RGBA|PNG_FORMAT_FLAG_COLORMAP) 2943 #define PNG_FORMAT_ARGB_COLORMAP (PNG_FORMAT_ARGB|PNG_FORMAT_FLAG_COLORMAP) 2944 #define PNG_FORMAT_BGRA_COLORMAP (PNG_FORMAT_BGRA|PNG_FORMAT_FLAG_COLORMAP) 2945 #define PNG_FORMAT_ABGR_COLORMAP (PNG_FORMAT_ABGR|PNG_FORMAT_FLAG_COLORMAP) 2946 2947 /* PNG_IMAGE macros 2948 * 2949 * These are convenience macros to derive information from a png_image 2950 * structure. The PNG_IMAGE_SAMPLE_ macros return values appropriate to the 2951 * actual image sample values - either the entries in the color-map or the 2952 * pixels in the image. The PNG_IMAGE_PIXEL_ macros return corresponding values 2953 * for the pixels and will always return 1 for color-mapped formats. The 2954 * remaining macros return information about the rows in the image and the 2955 * complete image. 2956 * 2957 * NOTE: All the macros that take a png_image::format parameter are compile time 2958 * constants if the format parameter is, itself, a constant. Therefore these 2959 * macros can be used in array declarations and case labels where required. 2960 * Similarly the macros are also pre-processor constants (sizeof is not used) so 2961 * they can be used in #if tests. 2962 * 2963 * First the information about the samples. 2964 */ 2965 #define PNG_IMAGE_SAMPLE_CHANNELS(fmt)\ 2966 (((fmt)&(PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_ALPHA))+1) 2967 /* Return the total number of channels in a given format: 1..4 */ 2968 2969 #define PNG_IMAGE_SAMPLE_COMPONENT_SIZE(fmt)\ 2970 ((((fmt) & PNG_FORMAT_FLAG_LINEAR) >> 2)+1) 2971 /* Return the size in bytes of a single component of a pixel or color-map 2972 * entry (as appropriate) in the image: 1 or 2. 2973 */ 2974 2975 #define PNG_IMAGE_SAMPLE_SIZE(fmt)\ 2976 (PNG_IMAGE_SAMPLE_CHANNELS(fmt) * PNG_IMAGE_SAMPLE_COMPONENT_SIZE(fmt)) 2977 /* This is the size of the sample data for one sample. If the image is 2978 * color-mapped it is the size of one color-map entry (and image pixels are 2979 * one byte in size), otherwise it is the size of one image pixel. 2980 */ 2981 2982 #define PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(fmt)\ 2983 (PNG_IMAGE_SAMPLE_CHANNELS(fmt) * 256) 2984 /* The maximum size of the color-map required by the format expressed in a 2985 * count of components. This can be used to compile-time allocate a 2986 * color-map: 2987 * 2988 * png_uint_16 colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(linear_fmt)]; 2989 * 2990 * png_byte colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(sRGB_fmt)]; 2991 * 2992 * Alternatively use the PNG_IMAGE_COLORMAP_SIZE macro below to use the 2993 * information from one of the png_image_begin_read_ APIs and dynamically 2994 * allocate the required memory. 2995 */ 2996 2997 /* Corresponding information about the pixels */ 2998 #define PNG_IMAGE_PIXEL_(test,fmt)\ 2999 (((fmt)&PNG_FORMAT_FLAG_COLORMAP)?1:test(fmt)) 3000 3001 #define PNG_IMAGE_PIXEL_CHANNELS(fmt)\ 3002 PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_CHANNELS,fmt) 3003 /* The number of separate channels (components) in a pixel; 1 for a 3004 * color-mapped image. 3005 */ 3006 3007 #define PNG_IMAGE_PIXEL_COMPONENT_SIZE(fmt)\ 3008 PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_COMPONENT_SIZE,fmt) 3009 /* The size, in bytes, of each component in a pixel; 1 for a color-mapped 3010 * image. 3011 */ 3012 3013 #define PNG_IMAGE_PIXEL_SIZE(fmt) PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_SIZE,fmt) 3014 /* The size, in bytes, of a complete pixel; 1 for a color-mapped image. */ 3015 3016 /* Information about the whole row, or whole image */ 3017 #define PNG_IMAGE_ROW_STRIDE(image)\ 3018 (PNG_IMAGE_PIXEL_CHANNELS((image).format) * (image).width) 3019 /* Return the total number of components in a single row of the image; this 3020 * is the minimum 'row stride', the minimum count of components between each 3021 * row. For a color-mapped image this is the minimum number of bytes in a 3022 * row. 3023 */ 3024 3025 #define PNG_IMAGE_BUFFER_SIZE(image, row_stride)\ 3026 (PNG_IMAGE_PIXEL_COMPONENT_SIZE((image).format)*(image).height*(row_stride)) 3027 /* Return the size, in bytes, of an image buffer given a png_image and a row 3028 * stride - the number of components to leave space for in each row. 3029 */ 3030 3031 #define PNG_IMAGE_SIZE(image)\ 3032 PNG_IMAGE_BUFFER_SIZE(image, PNG_IMAGE_ROW_STRIDE(image)) 3033 /* Return the size, in bytes, of the image in memory given just a png_image; 3034 * the row stride is the minimum stride required for the image. 3035 */ 3036 3037 #define PNG_IMAGE_COLORMAP_SIZE(image)\ 3038 (PNG_IMAGE_SAMPLE_SIZE((image).format) * (image).colormap_entries) 3039 /* Return the size, in bytes, of the color-map of this image. If the image 3040 * format is not a color-map format this will return a size sufficient for 3041 * 256 entries in the given format; check PNG_FORMAT_FLAG_COLORMAP if 3042 * you don't want to allocate a color-map in this case. 3043 */ 3044 3045 /* PNG_IMAGE_FLAG_* 3046 * 3047 * Flags containing additional information about the image are held in the 3048 * 'flags' field of png_image. 3049 */ 3050 #define PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB 0x01 3051 /* This indicates the the RGB values of the in-memory bitmap do not 3052 * correspond to the red, green and blue end-points defined by sRGB. 3053 */ 3054 3055 #define PNG_IMAGE_FLAG_FAST 0x02 3056 /* On write emphasise speed over compression; the resultant PNG file will be 3057 * larger but will be produced significantly faster, particular for large 3058 * images. Do not use this option for images which will be distributed, only 3059 * used it when producing intermediate files that will be read back in 3060 * repeatedly. For a typical 24-bit image the option will double the read 3061 * speed at the cost of increasing the image size by 25%, however for many 3062 * more compressible images the PNG file can be 10 times larger with only a 3063 * slight speed gain. 3064 */ 3065 3066 #define PNG_IMAGE_FLAG_16BIT_sRGB 0x04 3067 /* On read if the image is a 16-bit per component image and there is no gAMA 3068 * or sRGB chunk assume that the components are sRGB encoded. Notice that 3069 * images output by the simplified API always have gamma information; setting 3070 * this flag only affects the interpretation of 16-bit images from an 3071 * external source. It is recommended that the application expose this flag 3072 * to the user; the user can normally easily recognize the difference between 3073 * linear and sRGB encoding. This flag has no effect on write - the data 3074 * passed to the write APIs must have the correct encoding (as defined 3075 * above.) 3076 * 3077 * If the flag is not set (the default) input 16-bit per component data is 3078 * assumed to be linear. 3079 * 3080 * NOTE: the flag can only be set after the png_image_begin_read_ call, 3081 * because that call initializes the 'flags' field. 3082 */ 3083 3084 #ifdef PNG_SIMPLIFIED_READ_SUPPORTED 3085 /* READ APIs 3086 * --------- 3087 * 3088 * The png_image passed to the read APIs must have been initialized by setting 3089 * the png_controlp field 'opaque' to NULL (or, safer, memset the whole thing.) 3090 */ 3091 #ifdef PNG_STDIO_SUPPORTED 3092 PNG_EXPORT(234, int, png_image_begin_read_from_file, (png_imagep image, 3093 const char *file_name)); 3094 /* The named file is opened for read and the image header is filled in 3095 * from the PNG header in the file. 3096 */ 3097 3098 PNG_EXPORT(235, int, png_image_begin_read_from_stdio, (png_imagep image, 3099 FILE* file)); 3100 /* The PNG header is read from the stdio FILE object. */ 3101 #endif /* PNG_STDIO_SUPPORTED */ 3102 3103 PNG_EXPORT(236, int, png_image_begin_read_from_memory, (png_imagep image, 3104 png_const_voidp memory, png_size_t size)); 3105 /* The PNG header is read from the given memory buffer. */ 3106 3107 PNG_EXPORT(237, int, png_image_finish_read, (png_imagep image, 3108 png_const_colorp background, void *buffer, png_int_32 row_stride, 3109 void *colormap)); 3110 /* Finish reading the image into the supplied buffer and clean up the 3111 * png_image structure. 3112 * 3113 * row_stride is the step, in byte or 2-byte units as appropriate, 3114 * between adjacent rows. A positive stride indicates that the top-most row 3115 * is first in the buffer - the normal top-down arrangement. A negative 3116 * stride indicates that the bottom-most row is first in the buffer. 3117 * 3118 * background need only be supplied if an alpha channel must be removed from 3119 * a png_byte format and the removal is to be done by compositing on a solid 3120 * color; otherwise it may be NULL and any composition will be done directly 3121 * onto the buffer. The value is an sRGB color to use for the background, 3122 * for grayscale output the green channel is used. 3123 * 3124 * background must be supplied when an alpha channel must be removed from a 3125 * single byte color-mapped output format, in other words if: 3126 * 3127 * 1) The original format from png_image_begin_read_from_* had 3128 * PNG_FORMAT_FLAG_ALPHA set. 3129 * 2) The format set by the application does not. 3130 * 3) The format set by the application has PNG_FORMAT_FLAG_COLORMAP set and 3131 * PNG_FORMAT_FLAG_LINEAR *not* set. 3132 * 3133 * For linear output removing the alpha channel is always done by compositing 3134 * on black and background is ignored. 3135 * 3136 * colormap must be supplied when PNG_FORMAT_FLAG_COLORMAP is set. It must 3137 * be at least the size (in bytes) returned by PNG_IMAGE_COLORMAP_SIZE. 3138 * image->colormap_entries will be updated to the actual number of entries 3139 * written to the colormap; this may be less than the original value. 3140 */ 3141 3142 PNG_EXPORT(238, void, png_image_free, (png_imagep image)); 3143 /* Free any data allocated by libpng in image->opaque, setting the pointer to 3144 * NULL. May be called at any time after the structure is initialized. 3145 */ 3146 #endif /* PNG_SIMPLIFIED_READ_SUPPORTED */ 3147 3148 #ifdef PNG_SIMPLIFIED_WRITE_SUPPORTED 3149 #ifdef PNG_STDIO_SUPPORTED 3150 /* WRITE APIS 3151 * ---------- 3152 * For write you must initialize a png_image structure to describe the image to 3153 * be written. To do this use memset to set the whole structure to 0 then 3154 * initialize fields describing your image. 3155 * 3156 * version: must be set to PNG_IMAGE_VERSION 3157 * opaque: must be initialized to NULL 3158 * width: image width in pixels 3159 * height: image height in rows 3160 * format: the format of the data (image and color-map) you wish to write 3161 * flags: set to 0 unless one of the defined flags applies; set 3162 * PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB for color format images where the RGB 3163 * values do not correspond to the colors in sRGB. 3164 * colormap_entries: set to the number of entries in the color-map (0 to 256) 3165 */ 3166 PNG_EXPORT(239, int, png_image_write_to_file, (png_imagep image, 3167 const char *file, int convert_to_8bit, const void *buffer, 3168 png_int_32 row_stride, const void *colormap)); 3169 /* Write the image to the named file. */ 3170 3171 PNG_EXPORT(240, int, png_image_write_to_stdio, (png_imagep image, FILE *file, 3172 int convert_to_8_bit, const void *buffer, png_int_32 row_stride, 3173 const void *colormap)); 3174 /* Write the image to the given (FILE*). */ 3175 3176 /* With both write APIs if image is in one of the linear formats with 16-bit 3177 * data then setting convert_to_8_bit will cause the output to be an 8-bit PNG 3178 * gamma encoded according to the sRGB specification, otherwise a 16-bit linear 3179 * encoded PNG file is written. 3180 * 3181 * With color-mapped data formats the colormap parameter point to a color-map 3182 * with at least image->colormap_entries encoded in the specified format. If 3183 * the format is linear the written PNG color-map will be converted to sRGB 3184 * regardless of the convert_to_8_bit flag. 3185 * 3186 * With all APIs row_stride is handled as in the read APIs - it is the spacing 3187 * from one row to the next in component sized units (1 or 2 bytes) and if 3188 * negative indicates a bottom-up row layout in the buffer. 3189 * 3190 * Note that the write API does not support interlacing or sub-8-bit pixels. 3191 */ 3192 #endif /* PNG_STDIO_SUPPORTED */ 3193 #endif /* PNG_SIMPLIFIED_WRITE_SUPPORTED */ 3194 /******************************************************************************* 3195 * END OF SIMPLIFIED API 3196 ******************************************************************************/ 3197 3198 #ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED 3199 PNG_EXPORT(242, void, png_set_check_for_invalid_index, 3200 (png_structrp png_ptr, int allowed)); 3201 # ifdef PNG_GET_PALETTE_MAX_SUPPORTED 3202 PNG_EXPORT(243, int, png_get_palette_max, (png_const_structp png_ptr, 3203 png_const_infop info_ptr)); 3204 # endif 3205 #endif /* CHECK_FOR_INVALID_INDEX */ 3206 3207 /******************************************************************************* 3208 * IMPLEMENTATION OPTIONS 3209 ******************************************************************************* 3210 * 3211 * Support for arbitrary implementation-specific optimizations. The API allows 3212 * particular options to be turned on or off. 'Option' is the number of the 3213 * option and 'onoff' is 0 (off) or non-0 (on). The value returned is given 3214 * by the PNG_OPTION_ defines below. 3215 * 3216 * HARDWARE: normally hardware capabilites, such as the Intel SSE instructions, 3217 * are detected at run time, however sometimes it may be impossible 3218 * to do this in user mode, in which case it is necessary to discover 3219 * the capabilities in an OS specific way. Such capabilities are 3220 * listed here when libpng has support for them and must be turned 3221 * ON by the application if present. 3222 * 3223 * SOFTWARE: sometimes software optimizations actually result in performance 3224 * decrease on some architectures or systems, or with some sets of 3225 * PNG images. 'Software' options allow such optimizations to be 3226 * selected at run time. 3227 */ 3228 #ifdef PNG_SET_OPTION_SUPPORTED 3229 #ifdef PNG_ARM_NEON_API_SUPPORTED 3230 # define PNG_ARM_NEON 0 /* HARDWARE: ARM Neon SIMD instructions supported */ 3231 #endif 3232 #define PNG_MAXIMUM_INFLATE_WINDOW 2 /* SOFTWARE: force maximum window */ 3233 #define PNG_SKIP_sRGB_CHECK_PROFILE 4 /* SOFTWARE: Check ICC profile for sRGB */ 3234 #define PNG_OPTION_NEXT 6 /* Next option - numbers must be even */ 3235 3236 /* Return values: NOTE: there are four values and 'off' is *not* zero */ 3237 #define PNG_OPTION_UNSET 0 /* Unset - defaults to off */ 3238 #define PNG_OPTION_INVALID 1 /* Option number out of range */ 3239 #define PNG_OPTION_OFF 2 3240 #define PNG_OPTION_ON 3 3241 3242 PNG_EXPORT(244, int, png_set_option, (png_structrp png_ptr, int option, 3243 int onoff)); 3244 #endif 3245 3246 /******************************************************************************* 3247 * END OF HARDWARE AND SOFTWARE OPTIONS 3248 ******************************************************************************/ 3249 3250 /* Maintainer: Put new public prototypes here ^, in libpng.3, and project 3251 * defs, scripts/pnglibconf.h, and scripts/pnglibconf.h.prebuilt 3252 */ 3253 3254 /* The last ordinal number (this is the *last* one already used; the next 3255 * one to use is one more than this.) Maintainer, remember to add an entry to 3256 * scripts/symbols.def as well. 3257 */ 3258 #ifdef PNG_EXPORT_LAST_ORDINAL 3259 PNG_EXPORT_LAST_ORDINAL(244); 3260 #endif 3261 3262 #ifdef __cplusplus 3263 } 3264 #endif 3265 3266 #endif /* PNG_VERSION_INFO_ONLY */ 3267 /* Do not put anything past this line */ 3268 #endif /* PNG_H */ 3269