png.h 141 KB

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  1. /* png.h - header file for PNG reference library
  2. *
  3. * libpng version 1.6.34, September 29, 2017
  4. *
  5. * Copyright (c) 1998-2002,2004,2006-2017 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 0.89, June 1996, through 0.96, May 1997: Andreas Dilger
  14. * libpng versions 0.97, January 1998, through 1.6.34, September 29, 2017:
  15. * Glenn Randers-Pehrson.
  16. * See also "Contributing Authors", below.
  17. */
  18. /*
  19. * COPYRIGHT NOTICE, DISCLAIMER, and LICENSE:
  20. *
  21. * If you modify libpng you may insert additional notices immediately following
  22. * this sentence.
  23. *
  24. * This code is released under the libpng license.
  25. *
  26. * libpng versions 1.0.7, July 1, 2000 through 1.6.34, September 29, 2017 are
  27. * Copyright (c) 2000-2002, 2004, 2006-2017 Glenn Randers-Pehrson, are
  28. * derived from libpng-1.0.6, and are distributed according to the same
  29. * disclaimer and license as libpng-1.0.6 with the following individuals
  30. * added to the list of Contributing Authors:
  31. *
  32. * Simon-Pierre Cadieux
  33. * Eric S. Raymond
  34. * Mans Rullgard
  35. * Cosmin Truta
  36. * Gilles Vollant
  37. * James Yu
  38. * Mandar Sahastrabuddhe
  39. * Google Inc.
  40. * Vadim Barkov
  41. *
  42. * and with the following additions to the disclaimer:
  43. *
  44. * There is no warranty against interference with your enjoyment of the
  45. * library or against infringement. There is no warranty that our
  46. * efforts or the library will fulfill any of your particular purposes
  47. * or needs. This library is provided with all faults, and the entire
  48. * risk of satisfactory quality, performance, accuracy, and effort is with
  49. * the user.
  50. *
  51. * Some files in the "contrib" directory and some configure-generated
  52. * files that are distributed with libpng have other copyright owners and
  53. * are released under other open source licenses.
  54. *
  55. * libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are
  56. * Copyright (c) 1998-2000 Glenn Randers-Pehrson, are derived from
  57. * libpng-0.96, and are distributed according to the same disclaimer and
  58. * license as libpng-0.96, with the following individuals added to the list
  59. * of Contributing Authors:
  60. *
  61. * Tom Lane
  62. * Glenn Randers-Pehrson
  63. * Willem van Schaik
  64. *
  65. * libpng versions 0.89, June 1996, through 0.96, May 1997, are
  66. * Copyright (c) 1996-1997 Andreas Dilger, are derived from libpng-0.88,
  67. * and are distributed according to the same disclaimer and license as
  68. * libpng-0.88, with the following individuals added to the list of
  69. * Contributing Authors:
  70. *
  71. * John Bowler
  72. * Kevin Bracey
  73. * Sam Bushell
  74. * Magnus Holmgren
  75. * Greg Roelofs
  76. * Tom Tanner
  77. *
  78. * Some files in the "scripts" directory have other copyright owners
  79. * but are released under this license.
  80. *
  81. * libpng versions 0.5, May 1995, through 0.88, January 1996, are
  82. * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
  83. *
  84. * For the purposes of this copyright and license, "Contributing Authors"
  85. * is defined as the following set of individuals:
  86. *
  87. * Andreas Dilger
  88. * Dave Martindale
  89. * Guy Eric Schalnat
  90. * Paul Schmidt
  91. * Tim Wegner
  92. *
  93. * The PNG Reference Library is supplied "AS IS". The Contributing Authors
  94. * and Group 42, Inc. disclaim all warranties, expressed or implied,
  95. * including, without limitation, the warranties of merchantability and of
  96. * fitness for any purpose. The Contributing Authors and Group 42, Inc.
  97. * assume no liability for direct, indirect, incidental, special, exemplary,
  98. * or consequential damages, which may result from the use of the PNG
  99. * Reference Library, even if advised of the possibility of such damage.
  100. *
  101. * Permission is hereby granted to use, copy, modify, and distribute this
  102. * source code, or portions hereof, for any purpose, without fee, subject
  103. * to the following restrictions:
  104. *
  105. * 1. The origin of this source code must not be misrepresented.
  106. *
  107. * 2. Altered versions must be plainly marked as such and must not
  108. * be misrepresented as being the original source.
  109. *
  110. * 3. This Copyright notice may not be removed or altered from any
  111. * source or altered source distribution.
  112. *
  113. * The Contributing Authors and Group 42, Inc. specifically permit, without
  114. * fee, and encourage the use of this source code as a component to
  115. * supporting the PNG file format in commercial products. If you use this
  116. * source code in a product, acknowledgment is not required but would be
  117. * appreciated.
  118. *
  119. * END OF COPYRIGHT NOTICE, DISCLAIMER, and LICENSE.
  120. *
  121. * TRADEMARK:
  122. *
  123. * The name "libpng" has not been registered by the Copyright owner
  124. * as a trademark in any jurisdiction. However, because libpng has
  125. * been distributed and maintained world-wide, continually since 1995,
  126. * the Copyright owner claims "common-law trademark protection" in any
  127. * jurisdiction where common-law trademark is recognized.
  128. *
  129. * OSI CERTIFICATION:
  130. *
  131. * Libpng is OSI Certified Open Source Software. OSI Certified Open Source is
  132. * a certification mark of the Open Source Initiative. OSI has not addressed
  133. * the additional disclaimers inserted at version 1.0.7.
  134. *
  135. * EXPORT CONTROL:
  136. *
  137. * The Copyright owner believes that the Export Control Classification
  138. * Number (ECCN) for libpng is EAR99, which means not subject to export
  139. * controls or International Traffic in Arms Regulations (ITAR) because
  140. * it is open source, publicly available software, that does not contain
  141. * any encryption software. See the EAR, paragraphs 734.3(b)(3) and
  142. * 734.7(b).
  143. */
  144. /*
  145. * A "png_get_copyright" function is available, for convenient use in "about"
  146. * boxes and the like:
  147. *
  148. * printf("%s", png_get_copyright(NULL));
  149. *
  150. * Also, the PNG logo (in PNG format, of course) is supplied in the
  151. * files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31).
  152. */
  153. /*
  154. * The contributing authors would like to thank all those who helped
  155. * with testing, bug fixes, and patience. This wouldn't have been
  156. * possible without all of you.
  157. *
  158. * Thanks to Frank J. T. Wojcik for helping with the documentation.
  159. */
  160. /* Note about libpng version numbers:
  161. *
  162. * Due to various miscommunications, unforeseen code incompatibilities
  163. * and occasional factors outside the authors' control, version numbering
  164. * on the library has not always been consistent and straightforward.
  165. * The following table summarizes matters since version 0.89c, which was
  166. * the first widely used release:
  167. *
  168. * source png.h png.h shared-lib
  169. * version string int version
  170. * ------- ------ ----- ----------
  171. * 0.89c "1.0 beta 3" 0.89 89 1.0.89
  172. * 0.90 "1.0 beta 4" 0.90 90 0.90 [should have been 2.0.90]
  173. * 0.95 "1.0 beta 5" 0.95 95 0.95 [should have been 2.0.95]
  174. * 0.96 "1.0 beta 6" 0.96 96 0.96 [should have been 2.0.96]
  175. * 0.97b "1.00.97 beta 7" 1.00.97 97 1.0.1 [should have been 2.0.97]
  176. * 0.97c 0.97 97 2.0.97
  177. * 0.98 0.98 98 2.0.98
  178. * 0.99 0.99 98 2.0.99
  179. * 0.99a-m 0.99 99 2.0.99
  180. * 1.00 1.00 100 2.1.0 [100 should be 10000]
  181. * 1.0.0 (from here on, the 100 2.1.0 [100 should be 10000]
  182. * 1.0.1 png.h string is 10001 2.1.0
  183. * 1.0.1a-e identical to the 10002 from here on, the shared library
  184. * 1.0.2 source version) 10002 is 2.V where V is the source code
  185. * 1.0.2a-b 10003 version, except as noted.
  186. * 1.0.3 10003
  187. * 1.0.3a-d 10004
  188. * 1.0.4 10004
  189. * 1.0.4a-f 10005
  190. * 1.0.5 (+ 2 patches) 10005
  191. * 1.0.5a-d 10006
  192. * 1.0.5e-r 10100 (not source compatible)
  193. * 1.0.5s-v 10006 (not binary compatible)
  194. * 1.0.6 (+ 3 patches) 10006 (still binary incompatible)
  195. * 1.0.6d-f 10007 (still binary incompatible)
  196. * 1.0.6g 10007
  197. * 1.0.6h 10007 10.6h (testing xy.z so-numbering)
  198. * 1.0.6i 10007 10.6i
  199. * 1.0.6j 10007 2.1.0.6j (incompatible with 1.0.0)
  200. * 1.0.7beta11-14 DLLNUM 10007 2.1.0.7beta11-14 (binary compatible)
  201. * 1.0.7beta15-18 1 10007 2.1.0.7beta15-18 (binary compatible)
  202. * 1.0.7rc1-2 1 10007 2.1.0.7rc1-2 (binary compatible)
  203. * 1.0.7 1 10007 (still compatible)
  204. * ...
  205. * 1.0.19 10 10019 10.so.0.19[.0]
  206. * ...
  207. * 1.2.59 13 10257 12.so.0.59[.0]
  208. * ...
  209. * 1.5.30 15 10527 15.so.15.30[.0]
  210. * ...
  211. * 1.6.34 16 10633 16.so.16.34[.0]
  212. *
  213. * Henceforth the source version will match the shared-library major
  214. * and minor numbers; the shared-library major version number will be
  215. * used for changes in backward compatibility, as it is intended. The
  216. * PNG_LIBPNG_VER macro, which is not used within libpng but is available
  217. * for applications, is an unsigned integer of the form xyyzz corresponding
  218. * to the source version x.y.z (leading zeros in y and z). Beta versions
  219. * were given the previous public release number plus a letter, until
  220. * version 1.0.6j; from then on they were given the upcoming public
  221. * release number plus "betaNN" or "rcNN".
  222. *
  223. * Binary incompatibility exists only when applications make direct access
  224. * to the info_ptr or png_ptr members through png.h, and the compiled
  225. * application is loaded with a different version of the library.
  226. *
  227. * DLLNUM will change each time there are forward or backward changes
  228. * in binary compatibility (e.g., when a new feature is added).
  229. *
  230. * See libpng.txt or libpng.3 for more information. The PNG specification
  231. * is available as a W3C Recommendation and as an ISO Specification,
  232. * <https://www.w3.org/TR/2003/REC-PNG-20031110/
  233. */
  234. /*
  235. * Y2K compliance in libpng:
  236. * =========================
  237. *
  238. * September 29, 2017
  239. *
  240. * Since the PNG Development group is an ad-hoc body, we can't make
  241. * an official declaration.
  242. *
  243. * This is your unofficial assurance that libpng from version 0.71 and
  244. * upward through 1.6.34 are Y2K compliant. It is my belief that
  245. * earlier versions were also Y2K compliant.
  246. *
  247. * Libpng only has two year fields. One is a 2-byte unsigned integer
  248. * that will hold years up to 65535. The other, which is deprecated,
  249. * holds the date in text format, and will hold years up to 9999.
  250. *
  251. * The integer is
  252. * "png_uint_16 year" in png_time_struct.
  253. *
  254. * The string is
  255. * "char time_buffer[29]" in png_struct. This is no longer used
  256. * in libpng-1.6.x and will be removed from libpng-1.7.0.
  257. *
  258. * There are seven time-related functions:
  259. * png.c: png_convert_to_rfc_1123_buffer() in png.c
  260. * (formerly png_convert_to_rfc_1123() prior to libpng-1.5.x and
  261. * png_convert_to_rfc_1152() in error prior to libpng-0.98)
  262. * png_convert_from_struct_tm() in pngwrite.c, called in pngwrite.c
  263. * png_convert_from_time_t() in pngwrite.c
  264. * png_get_tIME() in pngget.c
  265. * png_handle_tIME() in pngrutil.c, called in pngread.c
  266. * png_set_tIME() in pngset.c
  267. * png_write_tIME() in pngwutil.c, called in pngwrite.c
  268. *
  269. * All handle dates properly in a Y2K environment. The
  270. * png_convert_from_time_t() function calls gmtime() to convert from system
  271. * clock time, which returns (year - 1900), which we properly convert to
  272. * the full 4-digit year. There is a possibility that libpng applications
  273. * are not passing 4-digit years into the png_convert_to_rfc_1123_buffer()
  274. * function, or that they are incorrectly passing only a 2-digit year
  275. * instead of "year - 1900" into the png_convert_from_struct_tm() function,
  276. * but this is not under our control. The libpng documentation has always
  277. * stated that it works with 4-digit years, and the APIs have been
  278. * documented as such.
  279. *
  280. * The tIME chunk itself is also Y2K compliant. It uses a 2-byte unsigned
  281. * integer to hold the year, and can hold years as large as 65535.
  282. *
  283. * zlib, upon which libpng depends, is also Y2K compliant. It contains
  284. * no date-related code.
  285. *
  286. * Glenn Randers-Pehrson
  287. * libpng maintainer
  288. * PNG Development Group
  289. */
  290. #ifndef PNG_H
  291. #define PNG_H
  292. /* This is not the place to learn how to use libpng. The file libpng-manual.txt
  293. * describes how to use libpng, and the file example.c summarizes it
  294. * with some code on which to build. This file is useful for looking
  295. * at the actual function definitions and structure components. If that
  296. * file has been stripped from your copy of libpng, you can find it at
  297. * <http://www.libpng.org/pub/png/libpng-manual.txt>
  298. *
  299. * If you just need to read a PNG file and don't want to read the documentation
  300. * skip to the end of this file and read the section entitled 'simplified API'.
  301. */
  302. /* Version information for png.h - this should match the version in png.c */
  303. #define PNG_LIBPNG_VER_STRING "1.6.34"
  304. #define PNG_HEADER_VERSION_STRING " libpng version 1.6.34 - September 29, 2017\n"
  305. #define PNG_LIBPNG_VER_SONUM 16
  306. #define PNG_LIBPNG_VER_DLLNUM 16
  307. /* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */
  308. #define PNG_LIBPNG_VER_MAJOR 1
  309. #define PNG_LIBPNG_VER_MINOR 6
  310. #define PNG_LIBPNG_VER_RELEASE 34
  311. /* This should match the numeric part of the final component of
  312. * PNG_LIBPNG_VER_STRING, omitting any leading zero:
  313. */
  314. #define PNG_LIBPNG_VER_BUILD 0
  315. /* Release Status */
  316. #define PNG_LIBPNG_BUILD_ALPHA 1
  317. #define PNG_LIBPNG_BUILD_BETA 2
  318. #define PNG_LIBPNG_BUILD_RC 3
  319. #define PNG_LIBPNG_BUILD_STABLE 4
  320. #define PNG_LIBPNG_BUILD_RELEASE_STATUS_MASK 7
  321. /* Release-Specific Flags */
  322. #define PNG_LIBPNG_BUILD_PATCH 8 /* Can be OR'ed with
  323. PNG_LIBPNG_BUILD_STABLE only */
  324. #define PNG_LIBPNG_BUILD_PRIVATE 16 /* Cannot be OR'ed with
  325. PNG_LIBPNG_BUILD_SPECIAL */
  326. #define PNG_LIBPNG_BUILD_SPECIAL 32 /* Cannot be OR'ed with
  327. PNG_LIBPNG_BUILD_PRIVATE */
  328. #define PNG_LIBPNG_BUILD_BASE_TYPE PNG_LIBPNG_BUILD_STABLE
  329. /* Careful here. At one time, Guy wanted to use 082, but that would be octal.
  330. * We must not include leading zeros.
  331. * Versions 0.7 through 1.0.0 were in the range 0 to 100 here (only
  332. * version 1.0.0 was mis-numbered 100 instead of 10000). From
  333. * version 1.0.1 it's xxyyzz, where x=major, y=minor, z=release
  334. */
  335. #define PNG_LIBPNG_VER 10634 /* 1.6.34 */
  336. /* Library configuration: these options cannot be changed after
  337. * the library has been built.
  338. */
  339. #ifndef PNGLCONF_H
  340. /* If pnglibconf.h is missing, you can
  341. * copy scripts/pnglibconf.h.prebuilt to pnglibconf.h
  342. */
  343. # include "pnglibconf.h"
  344. #endif
  345. #ifndef PNG_VERSION_INFO_ONLY
  346. /* Machine specific configuration. */
  347. # include "pngconf.h"
  348. #endif
  349. /*
  350. * Added at libpng-1.2.8
  351. *
  352. * Ref MSDN: Private as priority over Special
  353. * VS_FF_PRIVATEBUILD File *was not* built using standard release
  354. * procedures. If this value is given, the StringFileInfo block must
  355. * contain a PrivateBuild string.
  356. *
  357. * VS_FF_SPECIALBUILD File *was* built by the original company using
  358. * standard release procedures but is a variation of the standard
  359. * file of the same version number. If this value is given, the
  360. * StringFileInfo block must contain a SpecialBuild string.
  361. */
  362. #ifdef PNG_USER_PRIVATEBUILD /* From pnglibconf.h */
  363. # define PNG_LIBPNG_BUILD_TYPE \
  364. (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_PRIVATE)
  365. #else
  366. # ifdef PNG_LIBPNG_SPECIALBUILD
  367. # define PNG_LIBPNG_BUILD_TYPE \
  368. (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_SPECIAL)
  369. # else
  370. # define PNG_LIBPNG_BUILD_TYPE (PNG_LIBPNG_BUILD_BASE_TYPE)
  371. # endif
  372. #endif
  373. #ifndef PNG_VERSION_INFO_ONLY
  374. /* Inhibit C++ name-mangling for libpng functions but not for system calls. */
  375. #ifdef __cplusplus
  376. extern "C" {
  377. #endif /* __cplusplus */
  378. /* Version information for C files, stored in png.c. This had better match
  379. * the version above.
  380. */
  381. #define png_libpng_ver png_get_header_ver(NULL)
  382. /* This file is arranged in several sections:
  383. *
  384. * 1. [omitted]
  385. * 2. Any configuration options that can be specified by for the application
  386. * code when it is built. (Build time configuration is in pnglibconf.h)
  387. * 3. Type definitions (base types are defined in pngconf.h), structure
  388. * definitions.
  389. * 4. Exported library functions.
  390. * 5. Simplified API.
  391. * 6. Implementation options.
  392. *
  393. * The library source code has additional files (principally pngpriv.h) that
  394. * allow configuration of the library.
  395. */
  396. /* Section 1: [omitted] */
  397. /* Section 2: run time configuration
  398. * See pnglibconf.h for build time configuration
  399. *
  400. * Run time configuration allows the application to choose between
  401. * implementations of certain arithmetic APIs. The default is set
  402. * at build time and recorded in pnglibconf.h, but it is safe to
  403. * override these (and only these) settings. Note that this won't
  404. * change what the library does, only application code, and the
  405. * settings can (and probably should) be made on a per-file basis
  406. * by setting the #defines before including png.h
  407. *
  408. * Use macros to read integers from PNG data or use the exported
  409. * functions?
  410. * PNG_USE_READ_MACROS: use the macros (see below) Note that
  411. * the macros evaluate their argument multiple times.
  412. * PNG_NO_USE_READ_MACROS: call the relevant library function.
  413. *
  414. * Use the alternative algorithm for compositing alpha samples that
  415. * does not use division?
  416. * PNG_READ_COMPOSITE_NODIV_SUPPORTED: use the 'no division'
  417. * algorithm.
  418. * PNG_NO_READ_COMPOSITE_NODIV: use the 'division' algorithm.
  419. *
  420. * How to handle benign errors if PNG_ALLOW_BENIGN_ERRORS is
  421. * false?
  422. * PNG_ALLOW_BENIGN_ERRORS: map calls to the benign error
  423. * APIs to png_warning.
  424. * Otherwise the calls are mapped to png_error.
  425. */
  426. /* Section 3: type definitions, including structures and compile time
  427. * constants.
  428. * See pngconf.h for base types that vary by machine/system
  429. */
  430. /* This triggers a compiler error in png.c, if png.c and png.h
  431. * do not agree upon the version number.
  432. */
  433. typedef char* png_libpng_version_1_6_34;
  434. /* Basic control structions. Read libpng-manual.txt or libpng.3 for more info.
  435. *
  436. * png_struct is the cache of information used while reading or writing a single
  437. * PNG file. One of these is always required, although the simplified API
  438. * (below) hides the creation and destruction of it.
  439. */
  440. typedef struct png_struct_def png_struct;
  441. typedef const png_struct * png_const_structp;
  442. typedef png_struct * png_structp;
  443. typedef png_struct * * png_structpp;
  444. /* png_info contains information read from or to be written to a PNG file. One
  445. * or more of these must exist while reading or creating a PNG file. The
  446. * information is not used by libpng during read but is used to control what
  447. * gets written when a PNG file is created. "png_get_" function calls read
  448. * information during read and "png_set_" functions calls write information
  449. * when creating a PNG.
  450. * been moved into a separate header file that is not accessible to
  451. * applications. Read libpng-manual.txt or libpng.3 for more info.
  452. */
  453. typedef struct png_info_def png_info;
  454. typedef png_info * png_infop;
  455. typedef const png_info * png_const_infop;
  456. typedef png_info * * png_infopp;
  457. /* Types with names ending 'p' are pointer types. The corresponding types with
  458. * names ending 'rp' are identical pointer types except that the pointer is
  459. * marked 'restrict', which means that it is the only pointer to the object
  460. * passed to the function. Applications should not use the 'restrict' types;
  461. * it is always valid to pass 'p' to a pointer with a function argument of the
  462. * corresponding 'rp' type. Different compilers have different rules with
  463. * regard to type matching in the presence of 'restrict'. For backward
  464. * compatibility libpng callbacks never have 'restrict' in their parameters and,
  465. * consequentially, writing portable application code is extremely difficult if
  466. * an attempt is made to use 'restrict'.
  467. */
  468. typedef png_struct * PNG_RESTRICT png_structrp;
  469. typedef const png_struct * PNG_RESTRICT png_const_structrp;
  470. typedef png_info * PNG_RESTRICT png_inforp;
  471. typedef const png_info * PNG_RESTRICT png_const_inforp;
  472. /* Three color definitions. The order of the red, green, and blue, (and the
  473. * exact size) is not important, although the size of the fields need to
  474. * be png_byte or png_uint_16 (as defined below).
  475. */
  476. typedef struct png_color_struct
  477. {
  478. png_byte red;
  479. png_byte green;
  480. png_byte blue;
  481. } png_color;
  482. typedef png_color * png_colorp;
  483. typedef const png_color * png_const_colorp;
  484. typedef png_color * * png_colorpp;
  485. typedef struct png_color_16_struct
  486. {
  487. png_byte index; /* used for palette files */
  488. png_uint_16 red; /* for use in red green blue files */
  489. png_uint_16 green;
  490. png_uint_16 blue;
  491. png_uint_16 gray; /* for use in grayscale files */
  492. } png_color_16;
  493. typedef png_color_16 * png_color_16p;
  494. typedef const png_color_16 * png_const_color_16p;
  495. typedef png_color_16 * * png_color_16pp;
  496. typedef struct png_color_8_struct
  497. {
  498. png_byte red; /* for use in red green blue files */
  499. png_byte green;
  500. png_byte blue;
  501. png_byte gray; /* for use in grayscale files */
  502. png_byte alpha; /* for alpha channel files */
  503. } png_color_8;
  504. typedef png_color_8 * png_color_8p;
  505. typedef const png_color_8 * png_const_color_8p;
  506. typedef png_color_8 * * png_color_8pp;
  507. /*
  508. * The following two structures are used for the in-core representation
  509. * of sPLT chunks.
  510. */
  511. typedef struct png_sPLT_entry_struct
  512. {
  513. png_uint_16 red;
  514. png_uint_16 green;
  515. png_uint_16 blue;
  516. png_uint_16 alpha;
  517. png_uint_16 frequency;
  518. } png_sPLT_entry;
  519. typedef png_sPLT_entry * png_sPLT_entryp;
  520. typedef const png_sPLT_entry * png_const_sPLT_entryp;
  521. typedef png_sPLT_entry * * png_sPLT_entrypp;
  522. /* When the depth of the sPLT palette is 8 bits, the color and alpha samples
  523. * occupy the LSB of their respective members, and the MSB of each member
  524. * is zero-filled. The frequency member always occupies the full 16 bits.
  525. */
  526. typedef struct png_sPLT_struct
  527. {
  528. png_charp name; /* palette name */
  529. png_byte depth; /* depth of palette samples */
  530. png_sPLT_entryp entries; /* palette entries */
  531. png_int_32 nentries; /* number of palette entries */
  532. } png_sPLT_t;
  533. typedef png_sPLT_t * png_sPLT_tp;
  534. typedef const png_sPLT_t * png_const_sPLT_tp;
  535. typedef png_sPLT_t * * png_sPLT_tpp;
  536. #ifdef PNG_TEXT_SUPPORTED
  537. /* png_text holds the contents of a text/ztxt/itxt chunk in a PNG file,
  538. * and whether that contents is compressed or not. The "key" field
  539. * points to a regular zero-terminated C string. The "text" fields can be a
  540. * regular C string, an empty string, or a NULL pointer.
  541. * However, the structure returned by png_get_text() will always contain
  542. * the "text" field as a regular zero-terminated C string (possibly
  543. * empty), never a NULL pointer, so it can be safely used in printf() and
  544. * other string-handling functions. Note that the "itxt_length", "lang", and
  545. * "lang_key" members of the structure only exist when the library is built
  546. * with iTXt chunk support. Prior to libpng-1.4.0 the library was built by
  547. * default without iTXt support. Also note that when iTXt *is* supported,
  548. * the "lang" and "lang_key" fields contain NULL pointers when the
  549. * "compression" field contains * PNG_TEXT_COMPRESSION_NONE or
  550. * PNG_TEXT_COMPRESSION_zTXt. Note that the "compression value" is not the
  551. * same as what appears in the PNG tEXt/zTXt/iTXt chunk's "compression flag"
  552. * which is always 0 or 1, or its "compression method" which is always 0.
  553. */
  554. typedef struct png_text_struct
  555. {
  556. int compression; /* compression value:
  557. -1: tEXt, none
  558. 0: zTXt, deflate
  559. 1: iTXt, none
  560. 2: iTXt, deflate */
  561. png_charp key; /* keyword, 1-79 character description of "text" */
  562. png_charp text; /* comment, may be an empty string (ie "")
  563. or a NULL pointer */
  564. png_size_t text_length; /* length of the text string */
  565. png_size_t itxt_length; /* length of the itxt string */
  566. png_charp lang; /* language code, 0-79 characters
  567. or a NULL pointer */
  568. png_charp lang_key; /* keyword translated UTF-8 string, 0 or more
  569. chars or a NULL pointer */
  570. } png_text;
  571. typedef png_text * png_textp;
  572. typedef const png_text * png_const_textp;
  573. typedef png_text * * png_textpp;
  574. #endif
  575. /* Supported compression types for text in PNG files (tEXt, and zTXt).
  576. * The values of the PNG_TEXT_COMPRESSION_ defines should NOT be changed. */
  577. #define PNG_TEXT_COMPRESSION_NONE_WR -3
  578. #define PNG_TEXT_COMPRESSION_zTXt_WR -2
  579. #define PNG_TEXT_COMPRESSION_NONE -1
  580. #define PNG_TEXT_COMPRESSION_zTXt 0
  581. #define PNG_ITXT_COMPRESSION_NONE 1
  582. #define PNG_ITXT_COMPRESSION_zTXt 2
  583. #define PNG_TEXT_COMPRESSION_LAST 3 /* Not a valid value */
  584. /* png_time is a way to hold the time in an machine independent way.
  585. * Two conversions are provided, both from time_t and struct tm. There
  586. * is no portable way to convert to either of these structures, as far
  587. * as I know. If you know of a portable way, send it to me. As a side
  588. * note - PNG has always been Year 2000 compliant!
  589. */
  590. typedef struct png_time_struct
  591. {
  592. png_uint_16 year; /* full year, as in, 1995 */
  593. png_byte month; /* month of year, 1 - 12 */
  594. png_byte day; /* day of month, 1 - 31 */
  595. png_byte hour; /* hour of day, 0 - 23 */
  596. png_byte minute; /* minute of hour, 0 - 59 */
  597. png_byte second; /* second of minute, 0 - 60 (for leap seconds) */
  598. } png_time;
  599. typedef png_time * png_timep;
  600. typedef const png_time * png_const_timep;
  601. typedef png_time * * png_timepp;
  602. #if defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED) ||\
  603. defined(PNG_USER_CHUNKS_SUPPORTED)
  604. /* png_unknown_chunk is a structure to hold queued chunks for which there is
  605. * no specific support. The idea is that we can use this to queue
  606. * up private chunks for output even though the library doesn't actually
  607. * know about their semantics.
  608. *
  609. * The data in the structure is set by libpng on read and used on write.
  610. */
  611. typedef struct png_unknown_chunk_t
  612. {
  613. png_byte name[5]; /* Textual chunk name with '\0' terminator */
  614. png_byte *data; /* Data, should not be modified on read! */
  615. png_size_t size;
  616. /* On write 'location' must be set using the flag values listed below.
  617. * Notice that on read it is set by libpng however the values stored have
  618. * more bits set than are listed below. Always treat the value as a
  619. * bitmask. On write set only one bit - setting multiple bits may cause the
  620. * chunk to be written in multiple places.
  621. */
  622. png_byte location; /* mode of operation at read time */
  623. }
  624. png_unknown_chunk;
  625. typedef png_unknown_chunk * png_unknown_chunkp;
  626. typedef const png_unknown_chunk * png_const_unknown_chunkp;
  627. typedef png_unknown_chunk * * png_unknown_chunkpp;
  628. #endif
  629. /* Flag values for the unknown chunk location byte. */
  630. #define PNG_HAVE_IHDR 0x01
  631. #define PNG_HAVE_PLTE 0x02
  632. #define PNG_AFTER_IDAT 0x08
  633. /* Maximum positive integer used in PNG is (2^31)-1 */
  634. #define PNG_UINT_31_MAX ((png_uint_32)0x7fffffffL)
  635. #define PNG_UINT_32_MAX ((png_uint_32)(-1))
  636. #define PNG_SIZE_MAX ((png_size_t)(-1))
  637. /* These are constants for fixed point values encoded in the
  638. * PNG specification manner (x100000)
  639. */
  640. #define PNG_FP_1 100000
  641. #define PNG_FP_HALF 50000
  642. #define PNG_FP_MAX ((png_fixed_point)0x7fffffffL)
  643. #define PNG_FP_MIN (-PNG_FP_MAX)
  644. /* These describe the color_type field in png_info. */
  645. /* color type masks */
  646. #define PNG_COLOR_MASK_PALETTE 1
  647. #define PNG_COLOR_MASK_COLOR 2
  648. #define PNG_COLOR_MASK_ALPHA 4
  649. /* color types. Note that not all combinations are legal */
  650. #define PNG_COLOR_TYPE_GRAY 0
  651. #define PNG_COLOR_TYPE_PALETTE (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE)
  652. #define PNG_COLOR_TYPE_RGB (PNG_COLOR_MASK_COLOR)
  653. #define PNG_COLOR_TYPE_RGB_ALPHA (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_ALPHA)
  654. #define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA)
  655. /* aliases */
  656. #define PNG_COLOR_TYPE_RGBA PNG_COLOR_TYPE_RGB_ALPHA
  657. #define PNG_COLOR_TYPE_GA PNG_COLOR_TYPE_GRAY_ALPHA
  658. /* This is for compression type. PNG 1.0-1.2 only define the single type. */
  659. #define PNG_COMPRESSION_TYPE_BASE 0 /* Deflate method 8, 32K window */
  660. #define PNG_COMPRESSION_TYPE_DEFAULT PNG_COMPRESSION_TYPE_BASE
  661. /* This is for filter type. PNG 1.0-1.2 only define the single type. */
  662. #define PNG_FILTER_TYPE_BASE 0 /* Single row per-byte filtering */
  663. #define PNG_INTRAPIXEL_DIFFERENCING 64 /* Used only in MNG datastreams */
  664. #define PNG_FILTER_TYPE_DEFAULT PNG_FILTER_TYPE_BASE
  665. /* These are for the interlacing type. These values should NOT be changed. */
  666. #define PNG_INTERLACE_NONE 0 /* Non-interlaced image */
  667. #define PNG_INTERLACE_ADAM7 1 /* Adam7 interlacing */
  668. #define PNG_INTERLACE_LAST 2 /* Not a valid value */
  669. /* These are for the oFFs chunk. These values should NOT be changed. */
  670. #define PNG_OFFSET_PIXEL 0 /* Offset in pixels */
  671. #define PNG_OFFSET_MICROMETER 1 /* Offset in micrometers (1/10^6 meter) */
  672. #define PNG_OFFSET_LAST 2 /* Not a valid value */
  673. /* These are for the pCAL chunk. These values should NOT be changed. */
  674. #define PNG_EQUATION_LINEAR 0 /* Linear transformation */
  675. #define PNG_EQUATION_BASE_E 1 /* Exponential base e transform */
  676. #define PNG_EQUATION_ARBITRARY 2 /* Arbitrary base exponential transform */
  677. #define PNG_EQUATION_HYPERBOLIC 3 /* Hyperbolic sine transformation */
  678. #define PNG_EQUATION_LAST 4 /* Not a valid value */
  679. /* These are for the sCAL chunk. These values should NOT be changed. */
  680. #define PNG_SCALE_UNKNOWN 0 /* unknown unit (image scale) */
  681. #define PNG_SCALE_METER 1 /* meters per pixel */
  682. #define PNG_SCALE_RADIAN 2 /* radians per pixel */
  683. #define PNG_SCALE_LAST 3 /* Not a valid value */
  684. /* These are for the pHYs chunk. These values should NOT be changed. */
  685. #define PNG_RESOLUTION_UNKNOWN 0 /* pixels/unknown unit (aspect ratio) */
  686. #define PNG_RESOLUTION_METER 1 /* pixels/meter */
  687. #define PNG_RESOLUTION_LAST 2 /* Not a valid value */
  688. /* These are for the sRGB chunk. These values should NOT be changed. */
  689. #define PNG_sRGB_INTENT_PERCEPTUAL 0
  690. #define PNG_sRGB_INTENT_RELATIVE 1
  691. #define PNG_sRGB_INTENT_SATURATION 2
  692. #define PNG_sRGB_INTENT_ABSOLUTE 3
  693. #define PNG_sRGB_INTENT_LAST 4 /* Not a valid value */
  694. /* This is for text chunks */
  695. #define PNG_KEYWORD_MAX_LENGTH 79
  696. /* Maximum number of entries in PLTE/sPLT/tRNS arrays */
  697. #define PNG_MAX_PALETTE_LENGTH 256
  698. /* These determine if an ancillary chunk's data has been successfully read
  699. * from the PNG header, or if the application has filled in the corresponding
  700. * data in the info_struct to be written into the output file. The values
  701. * of the PNG_INFO_<chunk> defines should NOT be changed.
  702. */
  703. #define PNG_INFO_gAMA 0x0001U
  704. #define PNG_INFO_sBIT 0x0002U
  705. #define PNG_INFO_cHRM 0x0004U
  706. #define PNG_INFO_PLTE 0x0008U
  707. #define PNG_INFO_tRNS 0x0010U
  708. #define PNG_INFO_bKGD 0x0020U
  709. #define PNG_INFO_hIST 0x0040U
  710. #define PNG_INFO_pHYs 0x0080U
  711. #define PNG_INFO_oFFs 0x0100U
  712. #define PNG_INFO_tIME 0x0200U
  713. #define PNG_INFO_pCAL 0x0400U
  714. #define PNG_INFO_sRGB 0x0800U /* GR-P, 0.96a */
  715. #define PNG_INFO_iCCP 0x1000U /* ESR, 1.0.6 */
  716. #define PNG_INFO_sPLT 0x2000U /* ESR, 1.0.6 */
  717. #define PNG_INFO_sCAL 0x4000U /* ESR, 1.0.6 */
  718. #define PNG_INFO_IDAT 0x8000U /* ESR, 1.0.6 */
  719. #define PNG_INFO_eXIf 0x10000U /* GR-P, 1.6.31 */
  720. /* This is used for the transformation routines, as some of them
  721. * change these values for the row. It also should enable using
  722. * the routines for other purposes.
  723. */
  724. typedef struct png_row_info_struct
  725. {
  726. png_uint_32 width; /* width of row */
  727. png_size_t rowbytes; /* number of bytes in row */
  728. png_byte color_type; /* color type of row */
  729. png_byte bit_depth; /* bit depth of row */
  730. png_byte channels; /* number of channels (1, 2, 3, or 4) */
  731. png_byte pixel_depth; /* bits per pixel (depth * channels) */
  732. } png_row_info;
  733. typedef png_row_info * png_row_infop;
  734. typedef png_row_info * * png_row_infopp;
  735. /* These are the function types for the I/O functions and for the functions
  736. * that allow the user to override the default I/O functions with his or her
  737. * own. The png_error_ptr type should match that of user-supplied warning
  738. * and error functions, while the png_rw_ptr type should match that of the
  739. * user read/write data functions. Note that the 'write' function must not
  740. * modify the buffer it is passed. The 'read' function, on the other hand, is
  741. * expected to return the read data in the buffer.
  742. */
  743. typedef PNG_CALLBACK(void, *png_error_ptr, (png_structp, png_const_charp));
  744. typedef PNG_CALLBACK(void, *png_rw_ptr, (png_structp, png_bytep, png_size_t));
  745. typedef PNG_CALLBACK(void, *png_flush_ptr, (png_structp));
  746. typedef PNG_CALLBACK(void, *png_read_status_ptr, (png_structp, png_uint_32,
  747. int));
  748. typedef PNG_CALLBACK(void, *png_write_status_ptr, (png_structp, png_uint_32,
  749. int));
  750. #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
  751. typedef PNG_CALLBACK(void, *png_progressive_info_ptr, (png_structp, png_infop));
  752. typedef PNG_CALLBACK(void, *png_progressive_end_ptr, (png_structp, png_infop));
  753. /* The following callback receives png_uint_32 row_number, int pass for the
  754. * png_bytep data of the row. When transforming an interlaced image the
  755. * row number is the row number within the sub-image of the interlace pass, so
  756. * the value will increase to the height of the sub-image (not the full image)
  757. * then reset to 0 for the next pass.
  758. *
  759. * Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to
  760. * find the output pixel (x,y) given an interlaced sub-image pixel
  761. * (row,col,pass). (See below for these macros.)
  762. */
  763. typedef PNG_CALLBACK(void, *png_progressive_row_ptr, (png_structp, png_bytep,
  764. png_uint_32, int));
  765. #endif
  766. #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
  767. defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
  768. typedef PNG_CALLBACK(void, *png_user_transform_ptr, (png_structp, png_row_infop,
  769. png_bytep));
  770. #endif
  771. #ifdef PNG_USER_CHUNKS_SUPPORTED
  772. typedef PNG_CALLBACK(int, *png_user_chunk_ptr, (png_structp,
  773. png_unknown_chunkp));
  774. #endif
  775. #ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
  776. /* not used anywhere */
  777. /* typedef PNG_CALLBACK(void, *png_unknown_chunk_ptr, (png_structp)); */
  778. #endif
  779. #ifdef PNG_SETJMP_SUPPORTED
  780. /* This must match the function definition in <setjmp.h>, and the application
  781. * must include this before png.h to obtain the definition of jmp_buf. The
  782. * function is required to be PNG_NORETURN, but this is not checked. If the
  783. * function does return the application will crash via an abort() or similar
  784. * system level call.
  785. *
  786. * If you get a warning here while building the library you may need to make
  787. * changes to ensure that pnglibconf.h records the calling convention used by
  788. * your compiler. This may be very difficult - try using a different compiler
  789. * to build the library!
  790. */
  791. PNG_FUNCTION(void, (PNGCAPI *png_longjmp_ptr), PNGARG((jmp_buf, int)), typedef);
  792. #endif
  793. /* Transform masks for the high-level interface */
  794. #define PNG_TRANSFORM_IDENTITY 0x0000 /* read and write */
  795. #define PNG_TRANSFORM_STRIP_16 0x0001 /* read only */
  796. #define PNG_TRANSFORM_STRIP_ALPHA 0x0002 /* read only */
  797. #define PNG_TRANSFORM_PACKING 0x0004 /* read and write */
  798. #define PNG_TRANSFORM_PACKSWAP 0x0008 /* read and write */
  799. #define PNG_TRANSFORM_EXPAND 0x0010 /* read only */
  800. #define PNG_TRANSFORM_INVERT_MONO 0x0020 /* read and write */
  801. #define PNG_TRANSFORM_SHIFT 0x0040 /* read and write */
  802. #define PNG_TRANSFORM_BGR 0x0080 /* read and write */
  803. #define PNG_TRANSFORM_SWAP_ALPHA 0x0100 /* read and write */
  804. #define PNG_TRANSFORM_SWAP_ENDIAN 0x0200 /* read and write */
  805. #define PNG_TRANSFORM_INVERT_ALPHA 0x0400 /* read and write */
  806. #define PNG_TRANSFORM_STRIP_FILLER 0x0800 /* write only */
  807. /* Added to libpng-1.2.34 */
  808. #define PNG_TRANSFORM_STRIP_FILLER_BEFORE PNG_TRANSFORM_STRIP_FILLER
  809. #define PNG_TRANSFORM_STRIP_FILLER_AFTER 0x1000 /* write only */
  810. /* Added to libpng-1.4.0 */
  811. #define PNG_TRANSFORM_GRAY_TO_RGB 0x2000 /* read only */
  812. /* Added to libpng-1.5.4 */
  813. #define PNG_TRANSFORM_EXPAND_16 0x4000 /* read only */
  814. #if INT_MAX >= 0x8000 /* else this might break */
  815. #define PNG_TRANSFORM_SCALE_16 0x8000 /* read only */
  816. #endif
  817. /* Flags for MNG supported features */
  818. #define PNG_FLAG_MNG_EMPTY_PLTE 0x01
  819. #define PNG_FLAG_MNG_FILTER_64 0x04
  820. #define PNG_ALL_MNG_FEATURES 0x05
  821. /* NOTE: prior to 1.5 these functions had no 'API' style declaration,
  822. * this allowed the zlib default functions to be used on Windows
  823. * platforms. In 1.5 the zlib default malloc (which just calls malloc and
  824. * ignores the first argument) should be completely compatible with the
  825. * following.
  826. */
  827. typedef PNG_CALLBACK(png_voidp, *png_malloc_ptr, (png_structp,
  828. png_alloc_size_t));
  829. typedef PNG_CALLBACK(void, *png_free_ptr, (png_structp, png_voidp));
  830. /* Section 4: exported functions
  831. * Here are the function definitions most commonly used. This is not
  832. * the place to find out how to use libpng. See libpng-manual.txt for the
  833. * full explanation, see example.c for the summary. This just provides
  834. * a simple one line description of the use of each function.
  835. *
  836. * The PNG_EXPORT() and PNG_EXPORTA() macros used below are defined in
  837. * pngconf.h and in the *.dfn files in the scripts directory.
  838. *
  839. * PNG_EXPORT(ordinal, type, name, (args));
  840. *
  841. * ordinal: ordinal that is used while building
  842. * *.def files. The ordinal value is only
  843. * relevant when preprocessing png.h with
  844. * the *.dfn files for building symbol table
  845. * entries, and are removed by pngconf.h.
  846. * type: return type of the function
  847. * name: function name
  848. * args: function arguments, with types
  849. *
  850. * When we wish to append attributes to a function prototype we use
  851. * the PNG_EXPORTA() macro instead.
  852. *
  853. * PNG_EXPORTA(ordinal, type, name, (args), attributes);
  854. *
  855. * ordinal, type, name, and args: same as in PNG_EXPORT().
  856. * attributes: function attributes
  857. */
  858. /* Returns the version number of the library */
  859. PNG_EXPORT(1, png_uint_32, png_access_version_number, (void));
  860. /* Tell lib we have already handled the first <num_bytes> magic bytes.
  861. * Handling more than 8 bytes from the beginning of the file is an error.
  862. */
  863. PNG_EXPORT(2, void, png_set_sig_bytes, (png_structrp png_ptr, int num_bytes));
  864. /* Check sig[start] through sig[start + num_to_check - 1] to see if it's a
  865. * PNG file. Returns zero if the supplied bytes match the 8-byte PNG
  866. * signature, and non-zero otherwise. Having num_to_check == 0 or
  867. * start > 7 will always fail (ie return non-zero).
  868. */
  869. PNG_EXPORT(3, int, png_sig_cmp, (png_const_bytep sig, png_size_t start,
  870. png_size_t num_to_check));
  871. /* Simple signature checking function. This is the same as calling
  872. * png_check_sig(sig, n) := !png_sig_cmp(sig, 0, n).
  873. */
  874. #define png_check_sig(sig, n) !png_sig_cmp((sig), 0, (n))
  875. /* Allocate and initialize png_ptr struct for reading, and any other memory. */
  876. PNG_EXPORTA(4, png_structp, png_create_read_struct,
  877. (png_const_charp user_png_ver, png_voidp error_ptr,
  878. png_error_ptr error_fn, png_error_ptr warn_fn),
  879. PNG_ALLOCATED);
  880. /* Allocate and initialize png_ptr struct for writing, and any other memory */
  881. PNG_EXPORTA(5, png_structp, png_create_write_struct,
  882. (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
  883. png_error_ptr warn_fn),
  884. PNG_ALLOCATED);
  885. PNG_EXPORT(6, png_size_t, png_get_compression_buffer_size,
  886. (png_const_structrp png_ptr));
  887. PNG_EXPORT(7, void, png_set_compression_buffer_size, (png_structrp png_ptr,
  888. png_size_t size));
  889. /* Moved from pngconf.h in 1.4.0 and modified to ensure setjmp/longjmp
  890. * match up.
  891. */
  892. #ifdef PNG_SETJMP_SUPPORTED
  893. /* This function returns the jmp_buf built in to *png_ptr. It must be
  894. * supplied with an appropriate 'longjmp' function to use on that jmp_buf
  895. * unless the default error function is overridden in which case NULL is
  896. * acceptable. The size of the jmp_buf is checked against the actual size
  897. * allocated by the library - the call will return NULL on a mismatch
  898. * indicating an ABI mismatch.
  899. */
  900. PNG_EXPORT(8, jmp_buf*, png_set_longjmp_fn, (png_structrp png_ptr,
  901. png_longjmp_ptr longjmp_fn, size_t jmp_buf_size));
  902. # define png_jmpbuf(png_ptr) \
  903. (*png_set_longjmp_fn((png_ptr), longjmp, (sizeof (jmp_buf))))
  904. #else
  905. # define png_jmpbuf(png_ptr) \
  906. (LIBPNG_WAS_COMPILED_WITH__PNG_NO_SETJMP)
  907. #endif
  908. /* This function should be used by libpng applications in place of
  909. * longjmp(png_ptr->jmpbuf, val). If longjmp_fn() has been set, it
  910. * will use it; otherwise it will call PNG_ABORT(). This function was
  911. * added in libpng-1.5.0.
  912. */
  913. PNG_EXPORTA(9, void, png_longjmp, (png_const_structrp png_ptr, int val),
  914. PNG_NORETURN);
  915. #ifdef PNG_READ_SUPPORTED
  916. /* Reset the compression stream */
  917. PNG_EXPORTA(10, int, png_reset_zstream, (png_structrp png_ptr), PNG_DEPRECATED);
  918. #endif
  919. /* New functions added in libpng-1.0.2 (not enabled by default until 1.2.0) */
  920. #ifdef PNG_USER_MEM_SUPPORTED
  921. PNG_EXPORTA(11, png_structp, png_create_read_struct_2,
  922. (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
  923. png_error_ptr warn_fn,
  924. png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn),
  925. PNG_ALLOCATED);
  926. PNG_EXPORTA(12, png_structp, png_create_write_struct_2,
  927. (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
  928. png_error_ptr warn_fn,
  929. png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn),
  930. PNG_ALLOCATED);
  931. #endif
  932. /* Write the PNG file signature. */
  933. PNG_EXPORT(13, void, png_write_sig, (png_structrp png_ptr));
  934. /* Write a PNG chunk - size, type, (optional) data, CRC. */
  935. PNG_EXPORT(14, void, png_write_chunk, (png_structrp png_ptr, png_const_bytep
  936. chunk_name, png_const_bytep data, png_size_t length));
  937. /* Write the start of a PNG chunk - length and chunk name. */
  938. PNG_EXPORT(15, void, png_write_chunk_start, (png_structrp png_ptr,
  939. png_const_bytep chunk_name, png_uint_32 length));
  940. /* Write the data of a PNG chunk started with png_write_chunk_start(). */
  941. PNG_EXPORT(16, void, png_write_chunk_data, (png_structrp png_ptr,
  942. png_const_bytep data, png_size_t length));
  943. /* Finish a chunk started with png_write_chunk_start() (includes CRC). */
  944. PNG_EXPORT(17, void, png_write_chunk_end, (png_structrp png_ptr));
  945. /* Allocate and initialize the info structure */
  946. PNG_EXPORTA(18, png_infop, png_create_info_struct, (png_const_structrp png_ptr),
  947. PNG_ALLOCATED);
  948. /* DEPRECATED: this function allowed init structures to be created using the
  949. * default allocation method (typically malloc). Use is deprecated in 1.6.0 and
  950. * the API will be removed in the future.
  951. */
  952. PNG_EXPORTA(19, void, png_info_init_3, (png_infopp info_ptr,
  953. png_size_t png_info_struct_size), PNG_DEPRECATED);
  954. /* Writes all the PNG information before the image. */
  955. PNG_EXPORT(20, void, png_write_info_before_PLTE,
  956. (png_structrp png_ptr, png_const_inforp info_ptr));
  957. PNG_EXPORT(21, void, png_write_info,
  958. (png_structrp png_ptr, png_const_inforp info_ptr));
  959. #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
  960. /* Read the information before the actual image data. */
  961. PNG_EXPORT(22, void, png_read_info,
  962. (png_structrp png_ptr, png_inforp info_ptr));
  963. #endif
  964. #ifdef PNG_TIME_RFC1123_SUPPORTED
  965. /* Convert to a US string format: there is no localization support in this
  966. * routine. The original implementation used a 29 character buffer in
  967. * png_struct, this will be removed in future versions.
  968. */
  969. #if PNG_LIBPNG_VER < 10700
  970. /* To do: remove this from libpng17 (and from libpng17/png.c and pngstruct.h) */
  971. PNG_EXPORTA(23, png_const_charp, png_convert_to_rfc1123, (png_structrp png_ptr,
  972. png_const_timep ptime),PNG_DEPRECATED);
  973. #endif
  974. PNG_EXPORT(241, int, png_convert_to_rfc1123_buffer, (char out[29],
  975. png_const_timep ptime));
  976. #endif
  977. #ifdef PNG_CONVERT_tIME_SUPPORTED
  978. /* Convert from a struct tm to png_time */
  979. PNG_EXPORT(24, void, png_convert_from_struct_tm, (png_timep ptime,
  980. const struct tm * ttime));
  981. /* Convert from time_t to png_time. Uses gmtime() */
  982. PNG_EXPORT(25, void, png_convert_from_time_t, (png_timep ptime, time_t ttime));
  983. #endif /* CONVERT_tIME */
  984. #ifdef PNG_READ_EXPAND_SUPPORTED
  985. /* Expand data to 24-bit RGB, or 8-bit grayscale, with alpha if available. */
  986. PNG_EXPORT(26, void, png_set_expand, (png_structrp png_ptr));
  987. PNG_EXPORT(27, void, png_set_expand_gray_1_2_4_to_8, (png_structrp png_ptr));
  988. PNG_EXPORT(28, void, png_set_palette_to_rgb, (png_structrp png_ptr));
  989. PNG_EXPORT(29, void, png_set_tRNS_to_alpha, (png_structrp png_ptr));
  990. #endif
  991. #ifdef PNG_READ_EXPAND_16_SUPPORTED
  992. /* Expand to 16-bit channels, forces conversion of palette to RGB and expansion
  993. * of a tRNS chunk if present.
  994. */
  995. PNG_EXPORT(221, void, png_set_expand_16, (png_structrp png_ptr));
  996. #endif
  997. #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
  998. /* Use blue, green, red order for pixels. */
  999. PNG_EXPORT(30, void, png_set_bgr, (png_structrp png_ptr));
  1000. #endif
  1001. #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
  1002. /* Expand the grayscale to 24-bit RGB if necessary. */
  1003. PNG_EXPORT(31, void, png_set_gray_to_rgb, (png_structrp png_ptr));
  1004. #endif
  1005. #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
  1006. /* Reduce RGB to grayscale. */
  1007. #define PNG_ERROR_ACTION_NONE 1
  1008. #define PNG_ERROR_ACTION_WARN 2
  1009. #define PNG_ERROR_ACTION_ERROR 3
  1010. #define PNG_RGB_TO_GRAY_DEFAULT (-1)/*for red/green coefficients*/
  1011. PNG_FP_EXPORT(32, void, png_set_rgb_to_gray, (png_structrp png_ptr,
  1012. int error_action, double red, double green))
  1013. PNG_FIXED_EXPORT(33, void, png_set_rgb_to_gray_fixed, (png_structrp png_ptr,
  1014. int error_action, png_fixed_point red, png_fixed_point green))
  1015. PNG_EXPORT(34, png_byte, png_get_rgb_to_gray_status, (png_const_structrp
  1016. png_ptr));
  1017. #endif
  1018. #ifdef PNG_BUILD_GRAYSCALE_PALETTE_SUPPORTED
  1019. PNG_EXPORT(35, void, png_build_grayscale_palette, (int bit_depth,
  1020. png_colorp palette));
  1021. #endif
  1022. #ifdef PNG_READ_ALPHA_MODE_SUPPORTED
  1023. /* How the alpha channel is interpreted - this affects how the color channels
  1024. * of a PNG file are returned to the calling application when an alpha channel,
  1025. * or a tRNS chunk in a palette file, is present.
  1026. *
  1027. * This has no effect on the way pixels are written into a PNG output
  1028. * datastream. The color samples in a PNG datastream are never premultiplied
  1029. * with the alpha samples.
  1030. *
  1031. * The default is to return data according to the PNG specification: the alpha
  1032. * channel is a linear measure of the contribution of the pixel to the
  1033. * corresponding composited pixel, and the color channels are unassociated
  1034. * (not premultiplied). The gamma encoded color channels must be scaled
  1035. * according to the contribution and to do this it is necessary to undo
  1036. * the encoding, scale the color values, perform the composition and reencode
  1037. * the values. This is the 'PNG' mode.
  1038. *
  1039. * The alternative is to 'associate' the alpha with the color information by
  1040. * storing color channel values that have been scaled by the alpha.
  1041. * image. These are the 'STANDARD', 'ASSOCIATED' or 'PREMULTIPLIED' modes
  1042. * (the latter being the two common names for associated alpha color channels).
  1043. *
  1044. * For the 'OPTIMIZED' mode, a pixel is treated as opaque only if the alpha
  1045. * value is equal to the maximum value.
  1046. *
  1047. * The final choice is to gamma encode the alpha channel as well. This is
  1048. * broken because, in practice, no implementation that uses this choice
  1049. * correctly undoes the encoding before handling alpha composition. Use this
  1050. * choice only if other serious errors in the software or hardware you use
  1051. * mandate it; the typical serious error is for dark halos to appear around
  1052. * opaque areas of the composited PNG image because of arithmetic overflow.
  1053. *
  1054. * The API function png_set_alpha_mode specifies which of these choices to use
  1055. * with an enumerated 'mode' value and the gamma of the required output:
  1056. */
  1057. #define PNG_ALPHA_PNG 0 /* according to the PNG standard */
  1058. #define PNG_ALPHA_STANDARD 1 /* according to Porter/Duff */
  1059. #define PNG_ALPHA_ASSOCIATED 1 /* as above; this is the normal practice */
  1060. #define PNG_ALPHA_PREMULTIPLIED 1 /* as above */
  1061. #define PNG_ALPHA_OPTIMIZED 2 /* 'PNG' for opaque pixels, else 'STANDARD' */
  1062. #define PNG_ALPHA_BROKEN 3 /* the alpha channel is gamma encoded */
  1063. PNG_FP_EXPORT(227, void, png_set_alpha_mode, (png_structrp png_ptr, int mode,
  1064. double output_gamma))
  1065. PNG_FIXED_EXPORT(228, void, png_set_alpha_mode_fixed, (png_structrp png_ptr,
  1066. int mode, png_fixed_point output_gamma))
  1067. #endif
  1068. #if defined(PNG_GAMMA_SUPPORTED) || defined(PNG_READ_ALPHA_MODE_SUPPORTED)
  1069. /* The output_gamma value is a screen gamma in libpng terminology: it expresses
  1070. * how to decode the output values, not how they are encoded.
  1071. */
  1072. #define PNG_DEFAULT_sRGB -1 /* sRGB gamma and color space */
  1073. #define PNG_GAMMA_MAC_18 -2 /* Old Mac '1.8' gamma and color space */
  1074. #define PNG_GAMMA_sRGB 220000 /* Television standards--matches sRGB gamma */
  1075. #define PNG_GAMMA_LINEAR PNG_FP_1 /* Linear */
  1076. #endif
  1077. /* The following are examples of calls to png_set_alpha_mode to achieve the
  1078. * required overall gamma correction and, where necessary, alpha
  1079. * premultiplication.
  1080. *
  1081. * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB);
  1082. * This is the default libpng handling of the alpha channel - it is not
  1083. * pre-multiplied into the color components. In addition the call states
  1084. * that the output is for a sRGB system and causes all PNG files without gAMA
  1085. * chunks to be assumed to be encoded using sRGB.
  1086. *
  1087. * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC);
  1088. * In this case the output is assumed to be something like an sRGB conformant
  1089. * display preceeded by a power-law lookup table of power 1.45. This is how
  1090. * early Mac systems behaved.
  1091. *
  1092. * png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_GAMMA_LINEAR);
  1093. * This is the classic Jim Blinn approach and will work in academic
  1094. * environments where everything is done by the book. It has the shortcoming
  1095. * of assuming that input PNG data with no gamma information is linear - this
  1096. * is unlikely to be correct unless the PNG files where generated locally.
  1097. * Most of the time the output precision will be so low as to show
  1098. * significant banding in dark areas of the image.
  1099. *
  1100. * png_set_expand_16(pp);
  1101. * png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_DEFAULT_sRGB);
  1102. * This is a somewhat more realistic Jim Blinn inspired approach. PNG files
  1103. * are assumed to have the sRGB encoding if not marked with a gamma value and
  1104. * the output is always 16 bits per component. This permits accurate scaling
  1105. * and processing of the data. If you know that your input PNG files were
  1106. * generated locally you might need to replace PNG_DEFAULT_sRGB with the
  1107. * correct value for your system.
  1108. *
  1109. * png_set_alpha_mode(pp, PNG_ALPHA_OPTIMIZED, PNG_DEFAULT_sRGB);
  1110. * If you just need to composite the PNG image onto an existing background
  1111. * and if you control the code that does this you can use the optimization
  1112. * setting. In this case you just copy completely opaque pixels to the
  1113. * output. For pixels that are not completely transparent (you just skip
  1114. * those) you do the composition math using png_composite or png_composite_16
  1115. * below then encode the resultant 8-bit or 16-bit values to match the output
  1116. * encoding.
  1117. *
  1118. * Other cases
  1119. * If neither the PNG nor the standard linear encoding work for you because
  1120. * of the software or hardware you use then you have a big problem. The PNG
  1121. * case will probably result in halos around the image. The linear encoding
  1122. * will probably result in a washed out, too bright, image (it's actually too
  1123. * contrasty.) Try the ALPHA_OPTIMIZED mode above - this will probably
  1124. * substantially reduce the halos. Alternatively try:
  1125. *
  1126. * png_set_alpha_mode(pp, PNG_ALPHA_BROKEN, PNG_DEFAULT_sRGB);
  1127. * This option will also reduce the halos, but there will be slight dark
  1128. * halos round the opaque parts of the image where the background is light.
  1129. * In the OPTIMIZED mode the halos will be light halos where the background
  1130. * is dark. Take your pick - the halos are unavoidable unless you can get
  1131. * your hardware/software fixed! (The OPTIMIZED approach is slightly
  1132. * faster.)
  1133. *
  1134. * When the default gamma of PNG files doesn't match the output gamma.
  1135. * If you have PNG files with no gamma information png_set_alpha_mode allows
  1136. * you to provide a default gamma, but it also sets the ouput gamma to the
  1137. * matching value. If you know your PNG files have a gamma that doesn't
  1138. * match the output you can take advantage of the fact that
  1139. * png_set_alpha_mode always sets the output gamma but only sets the PNG
  1140. * default if it is not already set:
  1141. *
  1142. * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB);
  1143. * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC);
  1144. * The first call sets both the default and the output gamma values, the
  1145. * second call overrides the output gamma without changing the default. This
  1146. * is easier than achieving the same effect with png_set_gamma. You must use
  1147. * PNG_ALPHA_PNG for the first call - internal checking in png_set_alpha will
  1148. * fire if more than one call to png_set_alpha_mode and png_set_background is
  1149. * made in the same read operation, however multiple calls with PNG_ALPHA_PNG
  1150. * are ignored.
  1151. */
  1152. #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
  1153. PNG_EXPORT(36, void, png_set_strip_alpha, (png_structrp png_ptr));
  1154. #endif
  1155. #if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \
  1156. defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
  1157. PNG_EXPORT(37, void, png_set_swap_alpha, (png_structrp png_ptr));
  1158. #endif
  1159. #if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \
  1160. defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
  1161. PNG_EXPORT(38, void, png_set_invert_alpha, (png_structrp png_ptr));
  1162. #endif
  1163. #if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
  1164. /* Add a filler byte to 8-bit or 16-bit Gray or 24-bit or 48-bit RGB images. */
  1165. PNG_EXPORT(39, void, png_set_filler, (png_structrp png_ptr, png_uint_32 filler,
  1166. int flags));
  1167. /* The values of the PNG_FILLER_ defines should NOT be changed */
  1168. # define PNG_FILLER_BEFORE 0
  1169. # define PNG_FILLER_AFTER 1
  1170. /* Add an alpha byte to 8-bit or 16-bit Gray or 24-bit or 48-bit RGB images. */
  1171. PNG_EXPORT(40, void, png_set_add_alpha, (png_structrp png_ptr,
  1172. png_uint_32 filler, int flags));
  1173. #endif /* READ_FILLER || WRITE_FILLER */
  1174. #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
  1175. /* Swap bytes in 16-bit depth files. */
  1176. PNG_EXPORT(41, void, png_set_swap, (png_structrp png_ptr));
  1177. #endif
  1178. #if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
  1179. /* Use 1 byte per pixel in 1, 2, or 4-bit depth files. */
  1180. PNG_EXPORT(42, void, png_set_packing, (png_structrp png_ptr));
  1181. #endif
  1182. #if defined(PNG_READ_PACKSWAP_SUPPORTED) || \
  1183. defined(PNG_WRITE_PACKSWAP_SUPPORTED)
  1184. /* Swap packing order of pixels in bytes. */
  1185. PNG_EXPORT(43, void, png_set_packswap, (png_structrp png_ptr));
  1186. #endif
  1187. #if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
  1188. /* Converts files to legal bit depths. */
  1189. PNG_EXPORT(44, void, png_set_shift, (png_structrp png_ptr, png_const_color_8p
  1190. true_bits));
  1191. #endif
  1192. #if defined(PNG_READ_INTERLACING_SUPPORTED) || \
  1193. defined(PNG_WRITE_INTERLACING_SUPPORTED)
  1194. /* Have the code handle the interlacing. Returns the number of passes.
  1195. * MUST be called before png_read_update_info or png_start_read_image,
  1196. * otherwise it will not have the desired effect. Note that it is still
  1197. * necessary to call png_read_row or png_read_rows png_get_image_height
  1198. * times for each pass.
  1199. */
  1200. PNG_EXPORT(45, int, png_set_interlace_handling, (png_structrp png_ptr));
  1201. #endif
  1202. #if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
  1203. /* Invert monochrome files */
  1204. PNG_EXPORT(46, void, png_set_invert_mono, (png_structrp png_ptr));
  1205. #endif
  1206. #ifdef PNG_READ_BACKGROUND_SUPPORTED
  1207. /* Handle alpha and tRNS by replacing with a background color. Prior to
  1208. * libpng-1.5.4 this API must not be called before the PNG file header has been
  1209. * read. Doing so will result in unexpected behavior and possible warnings or
  1210. * errors if the PNG file contains a bKGD chunk.
  1211. */
  1212. PNG_FP_EXPORT(47, void, png_set_background, (png_structrp png_ptr,
  1213. png_const_color_16p background_color, int background_gamma_code,
  1214. int need_expand, double background_gamma))
  1215. PNG_FIXED_EXPORT(215, void, png_set_background_fixed, (png_structrp png_ptr,
  1216. png_const_color_16p background_color, int background_gamma_code,
  1217. int need_expand, png_fixed_point background_gamma))
  1218. #endif
  1219. #ifdef PNG_READ_BACKGROUND_SUPPORTED
  1220. # define PNG_BACKGROUND_GAMMA_UNKNOWN 0
  1221. # define PNG_BACKGROUND_GAMMA_SCREEN 1
  1222. # define PNG_BACKGROUND_GAMMA_FILE 2
  1223. # define PNG_BACKGROUND_GAMMA_UNIQUE 3
  1224. #endif
  1225. #ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
  1226. /* Scale a 16-bit depth file down to 8-bit, accurately. */
  1227. PNG_EXPORT(229, void, png_set_scale_16, (png_structrp png_ptr));
  1228. #endif
  1229. #ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
  1230. #define PNG_READ_16_TO_8_SUPPORTED /* Name prior to 1.5.4 */
  1231. /* Strip the second byte of information from a 16-bit depth file. */
  1232. PNG_EXPORT(48, void, png_set_strip_16, (png_structrp png_ptr));
  1233. #endif
  1234. #ifdef PNG_READ_QUANTIZE_SUPPORTED
  1235. /* Turn on quantizing, and reduce the palette to the number of colors
  1236. * available.
  1237. */
  1238. PNG_EXPORT(49, void, png_set_quantize, (png_structrp png_ptr,
  1239. png_colorp palette, int num_palette, int maximum_colors,
  1240. png_const_uint_16p histogram, int full_quantize));
  1241. #endif
  1242. #ifdef PNG_READ_GAMMA_SUPPORTED
  1243. /* The threshold on gamma processing is configurable but hard-wired into the
  1244. * library. The following is the floating point variant.
  1245. */
  1246. #define PNG_GAMMA_THRESHOLD (PNG_GAMMA_THRESHOLD_FIXED*.00001)
  1247. /* Handle gamma correction. Screen_gamma=(display_exponent).
  1248. * NOTE: this API simply sets the screen and file gamma values. It will
  1249. * therefore override the value for gamma in a PNG file if it is called after
  1250. * the file header has been read - use with care - call before reading the PNG
  1251. * file for best results!
  1252. *
  1253. * These routines accept the same gamma values as png_set_alpha_mode (described
  1254. * above). The PNG_GAMMA_ defines and PNG_DEFAULT_sRGB can be passed to either
  1255. * API (floating point or fixed.) Notice, however, that the 'file_gamma' value
  1256. * is the inverse of a 'screen gamma' value.
  1257. */
  1258. PNG_FP_EXPORT(50, void, png_set_gamma, (png_structrp png_ptr,
  1259. double screen_gamma, double override_file_gamma))
  1260. PNG_FIXED_EXPORT(208, void, png_set_gamma_fixed, (png_structrp png_ptr,
  1261. png_fixed_point screen_gamma, png_fixed_point override_file_gamma))
  1262. #endif
  1263. #ifdef PNG_WRITE_FLUSH_SUPPORTED
  1264. /* Set how many lines between output flushes - 0 for no flushing */
  1265. PNG_EXPORT(51, void, png_set_flush, (png_structrp png_ptr, int nrows));
  1266. /* Flush the current PNG output buffer */
  1267. PNG_EXPORT(52, void, png_write_flush, (png_structrp png_ptr));
  1268. #endif
  1269. /* Optional update palette with requested transformations */
  1270. PNG_EXPORT(53, void, png_start_read_image, (png_structrp png_ptr));
  1271. /* Optional call to update the users info structure */
  1272. PNG_EXPORT(54, void, png_read_update_info, (png_structrp png_ptr,
  1273. png_inforp info_ptr));
  1274. #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
  1275. /* Read one or more rows of image data. */
  1276. PNG_EXPORT(55, void, png_read_rows, (png_structrp png_ptr, png_bytepp row,
  1277. png_bytepp display_row, png_uint_32 num_rows));
  1278. #endif
  1279. #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
  1280. /* Read a row of data. */
  1281. PNG_EXPORT(56, void, png_read_row, (png_structrp png_ptr, png_bytep row,
  1282. png_bytep display_row));
  1283. #endif
  1284. #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
  1285. /* Read the whole image into memory at once. */
  1286. PNG_EXPORT(57, void, png_read_image, (png_structrp png_ptr, png_bytepp image));
  1287. #endif
  1288. /* Write a row of image data */
  1289. PNG_EXPORT(58, void, png_write_row, (png_structrp png_ptr,
  1290. png_const_bytep row));
  1291. /* Write a few rows of image data: (*row) is not written; however, the type
  1292. * is declared as writeable to maintain compatibility with previous versions
  1293. * of libpng and to allow the 'display_row' array from read_rows to be passed
  1294. * unchanged to write_rows.
  1295. */
  1296. PNG_EXPORT(59, void, png_write_rows, (png_structrp png_ptr, png_bytepp row,
  1297. png_uint_32 num_rows));
  1298. /* Write the image data */
  1299. PNG_EXPORT(60, void, png_write_image, (png_structrp png_ptr, png_bytepp image));
  1300. /* Write the end of the PNG file. */
  1301. PNG_EXPORT(61, void, png_write_end, (png_structrp png_ptr,
  1302. png_inforp info_ptr));
  1303. #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
  1304. /* Read the end of the PNG file. */
  1305. PNG_EXPORT(62, void, png_read_end, (png_structrp png_ptr, png_inforp info_ptr));
  1306. #endif
  1307. /* Free any memory associated with the png_info_struct */
  1308. PNG_EXPORT(63, void, png_destroy_info_struct, (png_const_structrp png_ptr,
  1309. png_infopp info_ptr_ptr));
  1310. /* Free any memory associated with the png_struct and the png_info_structs */
  1311. PNG_EXPORT(64, void, png_destroy_read_struct, (png_structpp png_ptr_ptr,
  1312. png_infopp info_ptr_ptr, png_infopp end_info_ptr_ptr));
  1313. /* Free any memory associated with the png_struct and the png_info_structs */
  1314. PNG_EXPORT(65, void, png_destroy_write_struct, (png_structpp png_ptr_ptr,
  1315. png_infopp info_ptr_ptr));
  1316. /* Set the libpng method of handling chunk CRC errors */
  1317. PNG_EXPORT(66, void, png_set_crc_action, (png_structrp png_ptr, int crit_action,
  1318. int ancil_action));
  1319. /* Values for png_set_crc_action() say how to handle CRC errors in
  1320. * ancillary and critical chunks, and whether to use the data contained
  1321. * therein. Note that it is impossible to "discard" data in a critical
  1322. * chunk. For versions prior to 0.90, the action was always error/quit,
  1323. * whereas in version 0.90 and later, the action for CRC errors in ancillary
  1324. * chunks is warn/discard. These values should NOT be changed.
  1325. *
  1326. * value action:critical action:ancillary
  1327. */
  1328. #define PNG_CRC_DEFAULT 0 /* error/quit warn/discard data */
  1329. #define PNG_CRC_ERROR_QUIT 1 /* error/quit error/quit */
  1330. #define PNG_CRC_WARN_DISCARD 2 /* (INVALID) warn/discard data */
  1331. #define PNG_CRC_WARN_USE 3 /* warn/use data warn/use data */
  1332. #define PNG_CRC_QUIET_USE 4 /* quiet/use data quiet/use data */
  1333. #define PNG_CRC_NO_CHANGE 5 /* use current value use current value */
  1334. #ifdef PNG_WRITE_SUPPORTED
  1335. /* These functions give the user control over the scan-line filtering in
  1336. * libpng and the compression methods used by zlib. These functions are
  1337. * mainly useful for testing, as the defaults should work with most users.
  1338. * Those users who are tight on memory or want faster performance at the
  1339. * expense of compression can modify them. See the compression library
  1340. * header file (zlib.h) for an explination of the compression functions.
  1341. */
  1342. /* Set the filtering method(s) used by libpng. Currently, the only valid
  1343. * value for "method" is 0.
  1344. */
  1345. PNG_EXPORT(67, void, png_set_filter, (png_structrp png_ptr, int method,
  1346. int filters));
  1347. #endif /* WRITE */
  1348. /* Flags for png_set_filter() to say which filters to use. The flags
  1349. * are chosen so that they don't conflict with real filter types
  1350. * below, in case they are supplied instead of the #defined constants.
  1351. * These values should NOT be changed.
  1352. */
  1353. #define PNG_NO_FILTERS 0x00
  1354. #define PNG_FILTER_NONE 0x08
  1355. #define PNG_FILTER_SUB 0x10
  1356. #define PNG_FILTER_UP 0x20
  1357. #define PNG_FILTER_AVG 0x40
  1358. #define PNG_FILTER_PAETH 0x80
  1359. #define PNG_FAST_FILTERS (PNG_FILTER_NONE | PNG_FILTER_SUB | PNG_FILTER_UP)
  1360. #define PNG_ALL_FILTERS (PNG_FAST_FILTERS | PNG_FILTER_AVG | PNG_FILTER_PAETH)
  1361. /* Filter values (not flags) - used in pngwrite.c, pngwutil.c for now.
  1362. * These defines should NOT be changed.
  1363. */
  1364. #define PNG_FILTER_VALUE_NONE 0
  1365. #define PNG_FILTER_VALUE_SUB 1
  1366. #define PNG_FILTER_VALUE_UP 2
  1367. #define PNG_FILTER_VALUE_AVG 3
  1368. #define PNG_FILTER_VALUE_PAETH 4
  1369. #define PNG_FILTER_VALUE_LAST 5
  1370. #ifdef PNG_WRITE_SUPPORTED
  1371. #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* DEPRECATED */
  1372. PNG_FP_EXPORT(68, void, png_set_filter_heuristics, (png_structrp png_ptr,
  1373. int heuristic_method, int num_weights, png_const_doublep filter_weights,
  1374. png_const_doublep filter_costs))
  1375. PNG_FIXED_EXPORT(209, void, png_set_filter_heuristics_fixed,
  1376. (png_structrp png_ptr, int heuristic_method, int num_weights,
  1377. png_const_fixed_point_p filter_weights,
  1378. png_const_fixed_point_p filter_costs))
  1379. #endif /* WRITE_WEIGHTED_FILTER */
  1380. /* The following are no longer used and will be removed from libpng-1.7: */
  1381. #define PNG_FILTER_HEURISTIC_DEFAULT 0 /* Currently "UNWEIGHTED" */
  1382. #define PNG_FILTER_HEURISTIC_UNWEIGHTED 1 /* Used by libpng < 0.95 */
  1383. #define PNG_FILTER_HEURISTIC_WEIGHTED 2 /* Experimental feature */
  1384. #define PNG_FILTER_HEURISTIC_LAST 3 /* Not a valid value */
  1385. /* Set the library compression level. Currently, valid values range from
  1386. * 0 - 9, corresponding directly to the zlib compression levels 0 - 9
  1387. * (0 - no compression, 9 - "maximal" compression). Note that tests have
  1388. * shown that zlib compression levels 3-6 usually perform as well as level 9
  1389. * for PNG images, and do considerably fewer caclulations. In the future,
  1390. * these values may not correspond directly to the zlib compression levels.
  1391. */
  1392. #ifdef PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED
  1393. PNG_EXPORT(69, void, png_set_compression_level, (png_structrp png_ptr,
  1394. int level));
  1395. PNG_EXPORT(70, void, png_set_compression_mem_level, (png_structrp png_ptr,
  1396. int mem_level));
  1397. PNG_EXPORT(71, void, png_set_compression_strategy, (png_structrp png_ptr,
  1398. int strategy));
  1399. /* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a
  1400. * smaller value of window_bits if it can do so safely.
  1401. */
  1402. PNG_EXPORT(72, void, png_set_compression_window_bits, (png_structrp png_ptr,
  1403. int window_bits));
  1404. PNG_EXPORT(73, void, png_set_compression_method, (png_structrp png_ptr,
  1405. int method));
  1406. #endif /* WRITE_CUSTOMIZE_COMPRESSION */
  1407. #ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
  1408. /* Also set zlib parameters for compressing non-IDAT chunks */
  1409. PNG_EXPORT(222, void, png_set_text_compression_level, (png_structrp png_ptr,
  1410. int level));
  1411. PNG_EXPORT(223, void, png_set_text_compression_mem_level, (png_structrp png_ptr,
  1412. int mem_level));
  1413. PNG_EXPORT(224, void, png_set_text_compression_strategy, (png_structrp png_ptr,
  1414. int strategy));
  1415. /* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a
  1416. * smaller value of window_bits if it can do so safely.
  1417. */
  1418. PNG_EXPORT(225, void, png_set_text_compression_window_bits,
  1419. (png_structrp png_ptr, int window_bits));
  1420. PNG_EXPORT(226, void, png_set_text_compression_method, (png_structrp png_ptr,
  1421. int method));
  1422. #endif /* WRITE_CUSTOMIZE_ZTXT_COMPRESSION */
  1423. #endif /* WRITE */
  1424. /* These next functions are called for input/output, memory, and error
  1425. * handling. They are in the file pngrio.c, pngwio.c, and pngerror.c,
  1426. * and call standard C I/O routines such as fread(), fwrite(), and
  1427. * fprintf(). These functions can be made to use other I/O routines
  1428. * at run time for those applications that need to handle I/O in a
  1429. * different manner by calling png_set_???_fn(). See libpng-manual.txt for
  1430. * more information.
  1431. */
  1432. #ifdef PNG_STDIO_SUPPORTED
  1433. /* Initialize the input/output for the PNG file to the default functions. */
  1434. PNG_EXPORT(74, void, png_init_io, (png_structrp png_ptr, png_FILE_p fp));
  1435. #endif
  1436. /* Replace the (error and abort), and warning functions with user
  1437. * supplied functions. If no messages are to be printed you must still
  1438. * write and use replacement functions. The replacement error_fn should
  1439. * still do a longjmp to the last setjmp location if you are using this
  1440. * method of error handling. If error_fn or warning_fn is NULL, the
  1441. * default function will be used.
  1442. */
  1443. PNG_EXPORT(75, void, png_set_error_fn, (png_structrp png_ptr,
  1444. png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warning_fn));
  1445. /* Return the user pointer associated with the error functions */
  1446. PNG_EXPORT(76, png_voidp, png_get_error_ptr, (png_const_structrp png_ptr));
  1447. /* Replace the default data output functions with a user supplied one(s).
  1448. * If buffered output is not used, then output_flush_fn can be set to NULL.
  1449. * If PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile time
  1450. * output_flush_fn will be ignored (and thus can be NULL).
  1451. * It is probably a mistake to use NULL for output_flush_fn if
  1452. * write_data_fn is not also NULL unless you have built libpng with
  1453. * PNG_WRITE_FLUSH_SUPPORTED undefined, because in this case libpng's
  1454. * default flush function, which uses the standard *FILE structure, will
  1455. * be used.
  1456. */
  1457. PNG_EXPORT(77, void, png_set_write_fn, (png_structrp png_ptr, png_voidp io_ptr,
  1458. png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn));
  1459. /* Replace the default data input function with a user supplied one. */
  1460. PNG_EXPORT(78, void, png_set_read_fn, (png_structrp png_ptr, png_voidp io_ptr,
  1461. png_rw_ptr read_data_fn));
  1462. /* Return the user pointer associated with the I/O functions */
  1463. PNG_EXPORT(79, png_voidp, png_get_io_ptr, (png_const_structrp png_ptr));
  1464. PNG_EXPORT(80, void, png_set_read_status_fn, (png_structrp png_ptr,
  1465. png_read_status_ptr read_row_fn));
  1466. PNG_EXPORT(81, void, png_set_write_status_fn, (png_structrp png_ptr,
  1467. png_write_status_ptr write_row_fn));
  1468. #ifdef PNG_USER_MEM_SUPPORTED
  1469. /* Replace the default memory allocation functions with user supplied one(s). */
  1470. PNG_EXPORT(82, void, png_set_mem_fn, (png_structrp png_ptr, png_voidp mem_ptr,
  1471. png_malloc_ptr malloc_fn, png_free_ptr free_fn));
  1472. /* Return the user pointer associated with the memory functions */
  1473. PNG_EXPORT(83, png_voidp, png_get_mem_ptr, (png_const_structrp png_ptr));
  1474. #endif
  1475. #ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
  1476. PNG_EXPORT(84, void, png_set_read_user_transform_fn, (png_structrp png_ptr,
  1477. png_user_transform_ptr read_user_transform_fn));
  1478. #endif
  1479. #ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
  1480. PNG_EXPORT(85, void, png_set_write_user_transform_fn, (png_structrp png_ptr,
  1481. png_user_transform_ptr write_user_transform_fn));
  1482. #endif
  1483. #ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
  1484. PNG_EXPORT(86, void, png_set_user_transform_info, (png_structrp png_ptr,
  1485. png_voidp user_transform_ptr, int user_transform_depth,
  1486. int user_transform_channels));
  1487. /* Return the user pointer associated with the user transform functions */
  1488. PNG_EXPORT(87, png_voidp, png_get_user_transform_ptr,
  1489. (png_const_structrp png_ptr));
  1490. #endif
  1491. #ifdef PNG_USER_TRANSFORM_INFO_SUPPORTED
  1492. /* Return information about the row currently being processed. Note that these
  1493. * APIs do not fail but will return unexpected results if called outside a user
  1494. * transform callback. Also note that when transforming an interlaced image the
  1495. * row number is the row number within the sub-image of the interlace pass, so
  1496. * the value will increase to the height of the sub-image (not the full image)
  1497. * then reset to 0 for the next pass.
  1498. *
  1499. * Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to
  1500. * find the output pixel (x,y) given an interlaced sub-image pixel
  1501. * (row,col,pass). (See below for these macros.)
  1502. */
  1503. PNG_EXPORT(217, png_uint_32, png_get_current_row_number, (png_const_structrp));
  1504. PNG_EXPORT(218, png_byte, png_get_current_pass_number, (png_const_structrp));
  1505. #endif
  1506. #ifdef PNG_READ_USER_CHUNKS_SUPPORTED
  1507. /* This callback is called only for *unknown* chunks. If
  1508. * PNG_HANDLE_AS_UNKNOWN_SUPPORTED is set then it is possible to set known
  1509. * chunks to be treated as unknown, however in this case the callback must do
  1510. * any processing required by the chunk (e.g. by calling the appropriate
  1511. * png_set_ APIs.)
  1512. *
  1513. * There is no write support - on write, by default, all the chunks in the
  1514. * 'unknown' list are written in the specified position.
  1515. *
  1516. * The integer return from the callback function is interpreted thus:
  1517. *
  1518. * negative: An error occurred; png_chunk_error will be called.
  1519. * zero: The chunk was not handled, the chunk will be saved. A critical
  1520. * chunk will cause an error at this point unless it is to be saved.
  1521. * positive: The chunk was handled, libpng will ignore/discard it.
  1522. *
  1523. * See "INTERACTION WTIH USER CHUNK CALLBACKS" below for important notes about
  1524. * how this behavior will change in libpng 1.7
  1525. */
  1526. PNG_EXPORT(88, void, png_set_read_user_chunk_fn, (png_structrp png_ptr,
  1527. png_voidp user_chunk_ptr, png_user_chunk_ptr read_user_chunk_fn));
  1528. #endif
  1529. #ifdef PNG_USER_CHUNKS_SUPPORTED
  1530. PNG_EXPORT(89, png_voidp, png_get_user_chunk_ptr, (png_const_structrp png_ptr));
  1531. #endif
  1532. #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
  1533. /* Sets the function callbacks for the push reader, and a pointer to a
  1534. * user-defined structure available to the callback functions.
  1535. */
  1536. PNG_EXPORT(90, void, png_set_progressive_read_fn, (png_structrp png_ptr,
  1537. png_voidp progressive_ptr, png_progressive_info_ptr info_fn,
  1538. png_progressive_row_ptr row_fn, png_progressive_end_ptr end_fn));
  1539. /* Returns the user pointer associated with the push read functions */
  1540. PNG_EXPORT(91, png_voidp, png_get_progressive_ptr,
  1541. (png_const_structrp png_ptr));
  1542. /* Function to be called when data becomes available */
  1543. PNG_EXPORT(92, void, png_process_data, (png_structrp png_ptr,
  1544. png_inforp info_ptr, png_bytep buffer, png_size_t buffer_size));
  1545. /* A function which may be called *only* within png_process_data to stop the
  1546. * processing of any more data. The function returns the number of bytes
  1547. * remaining, excluding any that libpng has cached internally. A subsequent
  1548. * call to png_process_data must supply these bytes again. If the argument
  1549. * 'save' is set to true the routine will first save all the pending data and
  1550. * will always return 0.
  1551. */
  1552. PNG_EXPORT(219, png_size_t, png_process_data_pause, (png_structrp, int save));
  1553. /* A function which may be called *only* outside (after) a call to
  1554. * png_process_data. It returns the number of bytes of data to skip in the
  1555. * input. Normally it will return 0, but if it returns a non-zero value the
  1556. * application must skip than number of bytes of input data and pass the
  1557. * following data to the next call to png_process_data.
  1558. */
  1559. PNG_EXPORT(220, png_uint_32, png_process_data_skip, (png_structrp));
  1560. /* Function that combines rows. 'new_row' is a flag that should come from
  1561. * the callback and be non-NULL if anything needs to be done; the library
  1562. * stores its own version of the new data internally and ignores the passed
  1563. * in value.
  1564. */
  1565. PNG_EXPORT(93, void, png_progressive_combine_row, (png_const_structrp png_ptr,
  1566. png_bytep old_row, png_const_bytep new_row));
  1567. #endif /* PROGRESSIVE_READ */
  1568. PNG_EXPORTA(94, png_voidp, png_malloc, (png_const_structrp png_ptr,
  1569. png_alloc_size_t size), PNG_ALLOCATED);
  1570. /* Added at libpng version 1.4.0 */
  1571. PNG_EXPORTA(95, png_voidp, png_calloc, (png_const_structrp png_ptr,
  1572. png_alloc_size_t size), PNG_ALLOCATED);
  1573. /* Added at libpng version 1.2.4 */
  1574. PNG_EXPORTA(96, png_voidp, png_malloc_warn, (png_const_structrp png_ptr,
  1575. png_alloc_size_t size), PNG_ALLOCATED);
  1576. /* Frees a pointer allocated by png_malloc() */
  1577. PNG_EXPORT(97, void, png_free, (png_const_structrp png_ptr, png_voidp ptr));
  1578. /* Free data that was allocated internally */
  1579. PNG_EXPORT(98, void, png_free_data, (png_const_structrp png_ptr,
  1580. png_inforp info_ptr, png_uint_32 free_me, int num));
  1581. /* Reassign responsibility for freeing existing data, whether allocated
  1582. * by libpng or by the application; this works on the png_info structure passed
  1583. * in, it does not change the state for other png_info structures.
  1584. *
  1585. * It is unlikely that this function works correctly as of 1.6.0 and using it
  1586. * may result either in memory leaks or double free of allocated data.
  1587. */
  1588. PNG_EXPORT(99, void, png_data_freer, (png_const_structrp png_ptr,
  1589. png_inforp info_ptr, int freer, png_uint_32 mask));
  1590. /* Assignments for png_data_freer */
  1591. #define PNG_DESTROY_WILL_FREE_DATA 1
  1592. #define PNG_SET_WILL_FREE_DATA 1
  1593. #define PNG_USER_WILL_FREE_DATA 2
  1594. /* Flags for png_ptr->free_me and info_ptr->free_me */
  1595. #define PNG_FREE_HIST 0x0008U
  1596. #define PNG_FREE_ICCP 0x0010U
  1597. #define PNG_FREE_SPLT 0x0020U
  1598. #define PNG_FREE_ROWS 0x0040U
  1599. #define PNG_FREE_PCAL 0x0080U
  1600. #define PNG_FREE_SCAL 0x0100U
  1601. #ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
  1602. # define PNG_FREE_UNKN 0x0200U
  1603. #endif
  1604. /* PNG_FREE_LIST 0x0400U removed in 1.6.0 because it is ignored */
  1605. #define PNG_FREE_PLTE 0x1000U
  1606. #define PNG_FREE_TRNS 0x2000U
  1607. #define PNG_FREE_TEXT 0x4000U
  1608. #define PNG_FREE_EXIF 0x8000U /* Added at libpng-1.6.31 */
  1609. #define PNG_FREE_ALL 0xffffU
  1610. #define PNG_FREE_MUL 0x4220U /* PNG_FREE_SPLT|PNG_FREE_TEXT|PNG_FREE_UNKN */
  1611. #ifdef PNG_USER_MEM_SUPPORTED
  1612. PNG_EXPORTA(100, png_voidp, png_malloc_default, (png_const_structrp png_ptr,
  1613. png_alloc_size_t size), PNG_ALLOCATED PNG_DEPRECATED);
  1614. PNG_EXPORTA(101, void, png_free_default, (png_const_structrp png_ptr,
  1615. png_voidp ptr), PNG_DEPRECATED);
  1616. #endif
  1617. #ifdef PNG_ERROR_TEXT_SUPPORTED
  1618. /* Fatal error in PNG image of libpng - can't continue */
  1619. PNG_EXPORTA(102, void, png_error, (png_const_structrp png_ptr,
  1620. png_const_charp error_message), PNG_NORETURN);
  1621. /* The same, but the chunk name is prepended to the error string. */
  1622. PNG_EXPORTA(103, void, png_chunk_error, (png_const_structrp png_ptr,
  1623. png_const_charp error_message), PNG_NORETURN);
  1624. #else
  1625. /* Fatal error in PNG image of libpng - can't continue */
  1626. PNG_EXPORTA(104, void, png_err, (png_const_structrp png_ptr), PNG_NORETURN);
  1627. # define png_error(s1,s2) png_err(s1)
  1628. # define png_chunk_error(s1,s2) png_err(s1)
  1629. #endif
  1630. #ifdef PNG_WARNINGS_SUPPORTED
  1631. /* Non-fatal error in libpng. Can continue, but may have a problem. */
  1632. PNG_EXPORT(105, void, png_warning, (png_const_structrp png_ptr,
  1633. png_const_charp warning_message));
  1634. /* Non-fatal error in libpng, chunk name is prepended to message. */
  1635. PNG_EXPORT(106, void, png_chunk_warning, (png_const_structrp png_ptr,
  1636. png_const_charp warning_message));
  1637. #else
  1638. # define png_warning(s1,s2) ((void)(s1))
  1639. # define png_chunk_warning(s1,s2) ((void)(s1))
  1640. #endif
  1641. #ifdef PNG_BENIGN_ERRORS_SUPPORTED
  1642. /* Benign error in libpng. Can continue, but may have a problem.
  1643. * User can choose whether to handle as a fatal error or as a warning. */
  1644. PNG_EXPORT(107, void, png_benign_error, (png_const_structrp png_ptr,
  1645. png_const_charp warning_message));
  1646. #ifdef PNG_READ_SUPPORTED
  1647. /* Same, chunk name is prepended to message (only during read) */
  1648. PNG_EXPORT(108, void, png_chunk_benign_error, (png_const_structrp png_ptr,
  1649. png_const_charp warning_message));
  1650. #endif
  1651. PNG_EXPORT(109, void, png_set_benign_errors,
  1652. (png_structrp png_ptr, int allowed));
  1653. #else
  1654. # ifdef PNG_ALLOW_BENIGN_ERRORS
  1655. # define png_benign_error png_warning
  1656. # define png_chunk_benign_error png_chunk_warning
  1657. # else
  1658. # define png_benign_error png_error
  1659. # define png_chunk_benign_error png_chunk_error
  1660. # endif
  1661. #endif
  1662. /* The png_set_<chunk> functions are for storing values in the png_info_struct.
  1663. * Similarly, the png_get_<chunk> calls are used to read values from the
  1664. * png_info_struct, either storing the parameters in the passed variables, or
  1665. * setting pointers into the png_info_struct where the data is stored. The
  1666. * png_get_<chunk> functions return a non-zero value if the data was available
  1667. * in info_ptr, or return zero and do not change any of the parameters if the
  1668. * data was not available.
  1669. *
  1670. * These functions should be used instead of directly accessing png_info
  1671. * to avoid problems with future changes in the size and internal layout of
  1672. * png_info_struct.
  1673. */
  1674. /* Returns "flag" if chunk data is valid in info_ptr. */
  1675. PNG_EXPORT(110, png_uint_32, png_get_valid, (png_const_structrp png_ptr,
  1676. png_const_inforp info_ptr, png_uint_32 flag));
  1677. /* Returns number of bytes needed to hold a transformed row. */
  1678. PNG_EXPORT(111, png_size_t, png_get_rowbytes, (png_const_structrp png_ptr,
  1679. png_const_inforp info_ptr));
  1680. #ifdef PNG_INFO_IMAGE_SUPPORTED
  1681. /* Returns row_pointers, which is an array of pointers to scanlines that was
  1682. * returned from png_read_png().
  1683. */
  1684. PNG_EXPORT(112, png_bytepp, png_get_rows, (png_const_structrp png_ptr,
  1685. png_const_inforp info_ptr));
  1686. /* Set row_pointers, which is an array of pointers to scanlines for use
  1687. * by png_write_png().
  1688. */
  1689. PNG_EXPORT(113, void, png_set_rows, (png_const_structrp png_ptr,
  1690. png_inforp info_ptr, png_bytepp row_pointers));
  1691. #endif
  1692. /* Returns number of color channels in image. */
  1693. PNG_EXPORT(114, png_byte, png_get_channels, (png_const_structrp png_ptr,
  1694. png_const_inforp info_ptr));
  1695. #ifdef PNG_EASY_ACCESS_SUPPORTED
  1696. /* Returns image width in pixels. */
  1697. PNG_EXPORT(115, png_uint_32, png_get_image_width, (png_const_structrp png_ptr,
  1698. png_const_inforp info_ptr));
  1699. /* Returns image height in pixels. */
  1700. PNG_EXPORT(116, png_uint_32, png_get_image_height, (png_const_structrp png_ptr,
  1701. png_const_inforp info_ptr));
  1702. /* Returns image bit_depth. */
  1703. PNG_EXPORT(117, png_byte, png_get_bit_depth, (png_const_structrp png_ptr,
  1704. png_const_inforp info_ptr));
  1705. /* Returns image color_type. */
  1706. PNG_EXPORT(118, png_byte, png_get_color_type, (png_const_structrp png_ptr,
  1707. png_const_inforp info_ptr));
  1708. /* Returns image filter_type. */
  1709. PNG_EXPORT(119, png_byte, png_get_filter_type, (png_const_structrp png_ptr,
  1710. png_const_inforp info_ptr));
  1711. /* Returns image interlace_type. */
  1712. PNG_EXPORT(120, png_byte, png_get_interlace_type, (png_const_structrp png_ptr,
  1713. png_const_inforp info_ptr));
  1714. /* Returns image compression_type. */
  1715. PNG_EXPORT(121, png_byte, png_get_compression_type, (png_const_structrp png_ptr,
  1716. png_const_inforp info_ptr));
  1717. /* Returns image resolution in pixels per meter, from pHYs chunk data. */
  1718. PNG_EXPORT(122, png_uint_32, png_get_pixels_per_meter,
  1719. (png_const_structrp png_ptr, png_const_inforp info_ptr));
  1720. PNG_EXPORT(123, png_uint_32, png_get_x_pixels_per_meter,
  1721. (png_const_structrp png_ptr, png_const_inforp info_ptr));
  1722. PNG_EXPORT(124, png_uint_32, png_get_y_pixels_per_meter,
  1723. (png_const_structrp png_ptr, png_const_inforp info_ptr));
  1724. /* Returns pixel aspect ratio, computed from pHYs chunk data. */
  1725. PNG_FP_EXPORT(125, float, png_get_pixel_aspect_ratio,
  1726. (png_const_structrp png_ptr, png_const_inforp info_ptr))
  1727. PNG_FIXED_EXPORT(210, png_fixed_point, png_get_pixel_aspect_ratio_fixed,
  1728. (png_const_structrp png_ptr, png_const_inforp info_ptr))
  1729. /* Returns image x, y offset in pixels or microns, from oFFs chunk data. */
  1730. PNG_EXPORT(126, png_int_32, png_get_x_offset_pixels,
  1731. (png_const_structrp png_ptr, png_const_inforp info_ptr));
  1732. PNG_EXPORT(127, png_int_32, png_get_y_offset_pixels,
  1733. (png_const_structrp png_ptr, png_const_inforp info_ptr));
  1734. PNG_EXPORT(128, png_int_32, png_get_x_offset_microns,
  1735. (png_const_structrp png_ptr, png_const_inforp info_ptr));
  1736. PNG_EXPORT(129, png_int_32, png_get_y_offset_microns,
  1737. (png_const_structrp png_ptr, png_const_inforp info_ptr));
  1738. #endif /* EASY_ACCESS */
  1739. #ifdef PNG_READ_SUPPORTED
  1740. /* Returns pointer to signature string read from PNG header */
  1741. PNG_EXPORT(130, png_const_bytep, png_get_signature, (png_const_structrp png_ptr,
  1742. png_const_inforp info_ptr));
  1743. #endif
  1744. #ifdef PNG_bKGD_SUPPORTED
  1745. PNG_EXPORT(131, png_uint_32, png_get_bKGD, (png_const_structrp png_ptr,
  1746. png_inforp info_ptr, png_color_16p *background));
  1747. #endif
  1748. #ifdef PNG_bKGD_SUPPORTED
  1749. PNG_EXPORT(132, void, png_set_bKGD, (png_const_structrp png_ptr,
  1750. png_inforp info_ptr, png_const_color_16p background));
  1751. #endif
  1752. #ifdef PNG_cHRM_SUPPORTED
  1753. PNG_FP_EXPORT(133, png_uint_32, png_get_cHRM, (png_const_structrp png_ptr,
  1754. png_const_inforp info_ptr, double *white_x, double *white_y, double *red_x,
  1755. double *red_y, double *green_x, double *green_y, double *blue_x,
  1756. double *blue_y))
  1757. PNG_FP_EXPORT(230, png_uint_32, png_get_cHRM_XYZ, (png_const_structrp png_ptr,
  1758. png_const_inforp info_ptr, double *red_X, double *red_Y, double *red_Z,
  1759. double *green_X, double *green_Y, double *green_Z, double *blue_X,
  1760. double *blue_Y, double *blue_Z))
  1761. PNG_FIXED_EXPORT(134, png_uint_32, png_get_cHRM_fixed,
  1762. (png_const_structrp png_ptr, png_const_inforp info_ptr,
  1763. png_fixed_point *int_white_x, png_fixed_point *int_white_y,
  1764. png_fixed_point *int_red_x, png_fixed_point *int_red_y,
  1765. png_fixed_point *int_green_x, png_fixed_point *int_green_y,
  1766. png_fixed_point *int_blue_x, png_fixed_point *int_blue_y))
  1767. PNG_FIXED_EXPORT(231, png_uint_32, png_get_cHRM_XYZ_fixed,
  1768. (png_const_structrp png_ptr, png_const_inforp info_ptr,
  1769. png_fixed_point *int_red_X, png_fixed_point *int_red_Y,
  1770. png_fixed_point *int_red_Z, png_fixed_point *int_green_X,
  1771. png_fixed_point *int_green_Y, png_fixed_point *int_green_Z,
  1772. png_fixed_point *int_blue_X, png_fixed_point *int_blue_Y,
  1773. png_fixed_point *int_blue_Z))
  1774. #endif
  1775. #ifdef PNG_cHRM_SUPPORTED
  1776. PNG_FP_EXPORT(135, void, png_set_cHRM, (png_const_structrp png_ptr,
  1777. png_inforp info_ptr,
  1778. double white_x, double white_y, double red_x, double red_y, double green_x,
  1779. double green_y, double blue_x, double blue_y))
  1780. PNG_FP_EXPORT(232, void, png_set_cHRM_XYZ, (png_const_structrp png_ptr,
  1781. png_inforp info_ptr, double red_X, double red_Y, double red_Z,
  1782. double green_X, double green_Y, double green_Z, double blue_X,
  1783. double blue_Y, double blue_Z))
  1784. PNG_FIXED_EXPORT(136, void, png_set_cHRM_fixed, (png_const_structrp png_ptr,
  1785. png_inforp info_ptr, png_fixed_point int_white_x,
  1786. png_fixed_point int_white_y, png_fixed_point int_red_x,
  1787. png_fixed_point int_red_y, png_fixed_point int_green_x,
  1788. png_fixed_point int_green_y, png_fixed_point int_blue_x,
  1789. png_fixed_point int_blue_y))
  1790. PNG_FIXED_EXPORT(233, void, png_set_cHRM_XYZ_fixed, (png_const_structrp png_ptr,
  1791. png_inforp info_ptr, png_fixed_point int_red_X, png_fixed_point int_red_Y,
  1792. png_fixed_point int_red_Z, png_fixed_point int_green_X,
  1793. png_fixed_point int_green_Y, png_fixed_point int_green_Z,
  1794. png_fixed_point int_blue_X, png_fixed_point int_blue_Y,
  1795. png_fixed_point int_blue_Z))
  1796. #endif
  1797. #ifdef PNG_eXIf_SUPPORTED
  1798. PNG_EXPORT(246, png_uint_32, png_get_eXIf, (png_const_structrp png_ptr,
  1799. png_inforp info_ptr, png_bytep *exif));
  1800. PNG_EXPORT(247, void, png_set_eXIf, (png_const_structrp png_ptr,
  1801. png_inforp info_ptr, const png_bytep exif));
  1802. PNG_EXPORT(248, png_uint_32, png_get_eXIf_1, (png_const_structrp png_ptr,
  1803. png_const_inforp info_ptr, png_uint_32 *num_exif, png_bytep *exif));
  1804. PNG_EXPORT(249, void, png_set_eXIf_1, (png_const_structrp png_ptr,
  1805. png_inforp info_ptr, const png_uint_32 num_exif, const png_bytep exif));
  1806. #endif
  1807. #ifdef PNG_gAMA_SUPPORTED
  1808. PNG_FP_EXPORT(137, png_uint_32, png_get_gAMA, (png_const_structrp png_ptr,
  1809. png_const_inforp info_ptr, double *file_gamma))
  1810. PNG_FIXED_EXPORT(138, png_uint_32, png_get_gAMA_fixed,
  1811. (png_const_structrp png_ptr, png_const_inforp info_ptr,
  1812. png_fixed_point *int_file_gamma))
  1813. #endif
  1814. #ifdef PNG_gAMA_SUPPORTED
  1815. PNG_FP_EXPORT(139, void, png_set_gAMA, (png_const_structrp png_ptr,
  1816. png_inforp info_ptr, double file_gamma))
  1817. PNG_FIXED_EXPORT(140, void, png_set_gAMA_fixed, (png_const_structrp png_ptr,
  1818. png_inforp info_ptr, png_fixed_point int_file_gamma))
  1819. #endif
  1820. #ifdef PNG_hIST_SUPPORTED
  1821. PNG_EXPORT(141, png_uint_32, png_get_hIST, (png_const_structrp png_ptr,
  1822. png_inforp info_ptr, png_uint_16p *hist));
  1823. PNG_EXPORT(142, void, png_set_hIST, (png_const_structrp png_ptr,
  1824. png_inforp info_ptr, png_const_uint_16p hist));
  1825. #endif
  1826. PNG_EXPORT(143, png_uint_32, png_get_IHDR, (png_const_structrp png_ptr,
  1827. png_const_inforp info_ptr, png_uint_32 *width, png_uint_32 *height,
  1828. int *bit_depth, int *color_type, int *interlace_method,
  1829. int *compression_method, int *filter_method));
  1830. PNG_EXPORT(144, void, png_set_IHDR, (png_const_structrp png_ptr,
  1831. png_inforp info_ptr, png_uint_32 width, png_uint_32 height, int bit_depth,
  1832. int color_type, int interlace_method, int compression_method,
  1833. int filter_method));
  1834. #ifdef PNG_oFFs_SUPPORTED
  1835. PNG_EXPORT(145, png_uint_32, png_get_oFFs, (png_const_structrp png_ptr,
  1836. png_const_inforp info_ptr, png_int_32 *offset_x, png_int_32 *offset_y,
  1837. int *unit_type));
  1838. #endif
  1839. #ifdef PNG_oFFs_SUPPORTED
  1840. PNG_EXPORT(146, void, png_set_oFFs, (png_const_structrp png_ptr,
  1841. png_inforp info_ptr, png_int_32 offset_x, png_int_32 offset_y,
  1842. int unit_type));
  1843. #endif
  1844. #ifdef PNG_pCAL_SUPPORTED
  1845. PNG_EXPORT(147, png_uint_32, png_get_pCAL, (png_const_structrp png_ptr,
  1846. png_inforp info_ptr, png_charp *purpose, png_int_32 *X0,
  1847. png_int_32 *X1, int *type, int *nparams, png_charp *units,
  1848. png_charpp *params));
  1849. #endif
  1850. #ifdef PNG_pCAL_SUPPORTED
  1851. PNG_EXPORT(148, void, png_set_pCAL, (png_const_structrp png_ptr,
  1852. png_inforp info_ptr, png_const_charp purpose, png_int_32 X0, png_int_32 X1,
  1853. int type, int nparams, png_const_charp units, png_charpp params));
  1854. #endif
  1855. #ifdef PNG_pHYs_SUPPORTED
  1856. PNG_EXPORT(149, png_uint_32, png_get_pHYs, (png_const_structrp png_ptr,
  1857. png_const_inforp info_ptr, png_uint_32 *res_x, png_uint_32 *res_y,
  1858. int *unit_type));
  1859. #endif
  1860. #ifdef PNG_pHYs_SUPPORTED
  1861. PNG_EXPORT(150, void, png_set_pHYs, (png_const_structrp png_ptr,
  1862. png_inforp info_ptr, png_uint_32 res_x, png_uint_32 res_y, int unit_type));
  1863. #endif
  1864. PNG_EXPORT(151, png_uint_32, png_get_PLTE, (png_const_structrp png_ptr,
  1865. png_inforp info_ptr, png_colorp *palette, int *num_palette));
  1866. PNG_EXPORT(152, void, png_set_PLTE, (png_structrp png_ptr,
  1867. png_inforp info_ptr, png_const_colorp palette, int num_palette));
  1868. #ifdef PNG_sBIT_SUPPORTED
  1869. PNG_EXPORT(153, png_uint_32, png_get_sBIT, (png_const_structrp png_ptr,
  1870. png_inforp info_ptr, png_color_8p *sig_bit));
  1871. #endif
  1872. #ifdef PNG_sBIT_SUPPORTED
  1873. PNG_EXPORT(154, void, png_set_sBIT, (png_const_structrp png_ptr,
  1874. png_inforp info_ptr, png_const_color_8p sig_bit));
  1875. #endif
  1876. #ifdef PNG_sRGB_SUPPORTED
  1877. PNG_EXPORT(155, png_uint_32, png_get_sRGB, (png_const_structrp png_ptr,
  1878. png_const_inforp info_ptr, int *file_srgb_intent));
  1879. #endif
  1880. #ifdef PNG_sRGB_SUPPORTED
  1881. PNG_EXPORT(156, void, png_set_sRGB, (png_const_structrp png_ptr,
  1882. png_inforp info_ptr, int srgb_intent));
  1883. PNG_EXPORT(157, void, png_set_sRGB_gAMA_and_cHRM, (png_const_structrp png_ptr,
  1884. png_inforp info_ptr, int srgb_intent));
  1885. #endif
  1886. #ifdef PNG_iCCP_SUPPORTED
  1887. PNG_EXPORT(158, png_uint_32, png_get_iCCP, (png_const_structrp png_ptr,
  1888. png_inforp info_ptr, png_charpp name, int *compression_type,
  1889. png_bytepp profile, png_uint_32 *proflen));
  1890. #endif
  1891. #ifdef PNG_iCCP_SUPPORTED
  1892. PNG_EXPORT(159, void, png_set_iCCP, (png_const_structrp png_ptr,
  1893. png_inforp info_ptr, png_const_charp name, int compression_type,
  1894. png_const_bytep profile, png_uint_32 proflen));
  1895. #endif
  1896. #ifdef PNG_sPLT_SUPPORTED
  1897. PNG_EXPORT(160, int, png_get_sPLT, (png_const_structrp png_ptr,
  1898. png_inforp info_ptr, png_sPLT_tpp entries));
  1899. #endif
  1900. #ifdef PNG_sPLT_SUPPORTED
  1901. PNG_EXPORT(161, void, png_set_sPLT, (png_const_structrp png_ptr,
  1902. png_inforp info_ptr, png_const_sPLT_tp entries, int nentries));
  1903. #endif
  1904. #ifdef PNG_TEXT_SUPPORTED
  1905. /* png_get_text also returns the number of text chunks in *num_text */
  1906. PNG_EXPORT(162, int, png_get_text, (png_const_structrp png_ptr,
  1907. png_inforp info_ptr, png_textp *text_ptr, int *num_text));
  1908. #endif
  1909. /* Note while png_set_text() will accept a structure whose text,
  1910. * language, and translated keywords are NULL pointers, the structure
  1911. * returned by png_get_text will always contain regular
  1912. * zero-terminated C strings. They might be empty strings but
  1913. * they will never be NULL pointers.
  1914. */
  1915. #ifdef PNG_TEXT_SUPPORTED
  1916. PNG_EXPORT(163, void, png_set_text, (png_const_structrp png_ptr,
  1917. png_inforp info_ptr, png_const_textp text_ptr, int num_text));
  1918. #endif
  1919. #ifdef PNG_tIME_SUPPORTED
  1920. PNG_EXPORT(164, png_uint_32, png_get_tIME, (png_const_structrp png_ptr,
  1921. png_inforp info_ptr, png_timep *mod_time));
  1922. #endif
  1923. #ifdef PNG_tIME_SUPPORTED
  1924. PNG_EXPORT(165, void, png_set_tIME, (png_const_structrp png_ptr,
  1925. png_inforp info_ptr, png_const_timep mod_time));
  1926. #endif
  1927. #ifdef PNG_tRNS_SUPPORTED
  1928. PNG_EXPORT(166, png_uint_32, png_get_tRNS, (png_const_structrp png_ptr,
  1929. png_inforp info_ptr, png_bytep *trans_alpha, int *num_trans,
  1930. png_color_16p *trans_color));
  1931. #endif
  1932. #ifdef PNG_tRNS_SUPPORTED
  1933. PNG_EXPORT(167, void, png_set_tRNS, (png_structrp png_ptr,
  1934. png_inforp info_ptr, png_const_bytep trans_alpha, int num_trans,
  1935. png_const_color_16p trans_color));
  1936. #endif
  1937. #ifdef PNG_sCAL_SUPPORTED
  1938. PNG_FP_EXPORT(168, png_uint_32, png_get_sCAL, (png_const_structrp png_ptr,
  1939. png_const_inforp info_ptr, int *unit, double *width, double *height))
  1940. #if defined(PNG_FLOATING_ARITHMETIC_SUPPORTED) || \
  1941. defined(PNG_FLOATING_POINT_SUPPORTED)
  1942. /* NOTE: this API is currently implemented using floating point arithmetic,
  1943. * consequently it can only be used on systems with floating point support.
  1944. * In any case the range of values supported by png_fixed_point is small and it
  1945. * is highly recommended that png_get_sCAL_s be used instead.
  1946. */
  1947. PNG_FIXED_EXPORT(214, png_uint_32, png_get_sCAL_fixed,
  1948. (png_const_structrp png_ptr, png_const_inforp info_ptr, int *unit,
  1949. png_fixed_point *width, png_fixed_point *height))
  1950. #endif
  1951. PNG_EXPORT(169, png_uint_32, png_get_sCAL_s,
  1952. (png_const_structrp png_ptr, png_const_inforp info_ptr, int *unit,
  1953. png_charpp swidth, png_charpp sheight));
  1954. PNG_FP_EXPORT(170, void, png_set_sCAL, (png_const_structrp png_ptr,
  1955. png_inforp info_ptr, int unit, double width, double height))
  1956. PNG_FIXED_EXPORT(213, void, png_set_sCAL_fixed, (png_const_structrp png_ptr,
  1957. png_inforp info_ptr, int unit, png_fixed_point width,
  1958. png_fixed_point height))
  1959. PNG_EXPORT(171, void, png_set_sCAL_s, (png_const_structrp png_ptr,
  1960. png_inforp info_ptr, int unit,
  1961. png_const_charp swidth, png_const_charp sheight));
  1962. #endif /* sCAL */
  1963. #ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
  1964. /* Provide the default handling for all unknown chunks or, optionally, for
  1965. * specific unknown chunks.
  1966. *
  1967. * NOTE: prior to 1.6.0 the handling specified for particular chunks on read was
  1968. * ignored and the default was used, the per-chunk setting only had an effect on
  1969. * write. If you wish to have chunk-specific handling on read in code that must
  1970. * work on earlier versions you must use a user chunk callback to specify the
  1971. * desired handling (keep or discard.)
  1972. *
  1973. * The 'keep' parameter is a PNG_HANDLE_CHUNK_ value as listed below. The
  1974. * parameter is interpreted as follows:
  1975. *
  1976. * READ:
  1977. * PNG_HANDLE_CHUNK_AS_DEFAULT:
  1978. * Known chunks: do normal libpng processing, do not keep the chunk (but
  1979. * see the comments below about PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
  1980. * Unknown chunks: for a specific chunk use the global default, when used
  1981. * as the default discard the chunk data.
  1982. * PNG_HANDLE_CHUNK_NEVER:
  1983. * Discard the chunk data.
  1984. * PNG_HANDLE_CHUNK_IF_SAFE:
  1985. * Keep the chunk data if the chunk is not critical else raise a chunk
  1986. * error.
  1987. * PNG_HANDLE_CHUNK_ALWAYS:
  1988. * Keep the chunk data.
  1989. *
  1990. * If the chunk data is saved it can be retrieved using png_get_unknown_chunks,
  1991. * below. Notice that specifying "AS_DEFAULT" as a global default is equivalent
  1992. * to specifying "NEVER", however when "AS_DEFAULT" is used for specific chunks
  1993. * it simply resets the behavior to the libpng default.
  1994. *
  1995. * INTERACTION WTIH USER CHUNK CALLBACKS:
  1996. * The per-chunk handling is always used when there is a png_user_chunk_ptr
  1997. * callback and the callback returns 0; the chunk is then always stored *unless*
  1998. * it is critical and the per-chunk setting is other than ALWAYS. Notice that
  1999. * the global default is *not* used in this case. (In effect the per-chunk
  2000. * value is incremented to at least IF_SAFE.)
  2001. *
  2002. * IMPORTANT NOTE: this behavior will change in libpng 1.7 - the global and
  2003. * per-chunk defaults will be honored. If you want to preserve the current
  2004. * behavior when your callback returns 0 you must set PNG_HANDLE_CHUNK_IF_SAFE
  2005. * as the default - if you don't do this libpng 1.6 will issue a warning.
  2006. *
  2007. * If you want unhandled unknown chunks to be discarded in libpng 1.6 and
  2008. * earlier simply return '1' (handled).
  2009. *
  2010. * PNG_HANDLE_AS_UNKNOWN_SUPPORTED:
  2011. * If this is *not* set known chunks will always be handled by libpng and
  2012. * will never be stored in the unknown chunk list. Known chunks listed to
  2013. * png_set_keep_unknown_chunks will have no effect. If it is set then known
  2014. * chunks listed with a keep other than AS_DEFAULT will *never* be processed
  2015. * by libpng, in addition critical chunks must either be processed by the
  2016. * callback or saved.
  2017. *
  2018. * The IHDR and IEND chunks must not be listed. Because this turns off the
  2019. * default handling for chunks that would otherwise be recognized the
  2020. * behavior of libpng transformations may well become incorrect!
  2021. *
  2022. * WRITE:
  2023. * When writing chunks the options only apply to the chunks specified by
  2024. * png_set_unknown_chunks (below), libpng will *always* write known chunks
  2025. * required by png_set_ calls and will always write the core critical chunks
  2026. * (as required for PLTE).
  2027. *
  2028. * Each chunk in the png_set_unknown_chunks list is looked up in the
  2029. * png_set_keep_unknown_chunks list to find the keep setting, this is then
  2030. * interpreted as follows:
  2031. *
  2032. * PNG_HANDLE_CHUNK_AS_DEFAULT:
  2033. * Write safe-to-copy chunks and write other chunks if the global
  2034. * default is set to _ALWAYS, otherwise don't write this chunk.
  2035. * PNG_HANDLE_CHUNK_NEVER:
  2036. * Do not write the chunk.
  2037. * PNG_HANDLE_CHUNK_IF_SAFE:
  2038. * Write the chunk if it is safe-to-copy, otherwise do not write it.
  2039. * PNG_HANDLE_CHUNK_ALWAYS:
  2040. * Write the chunk.
  2041. *
  2042. * Note that the default behavior is effectively the opposite of the read case -
  2043. * in read unknown chunks are not stored by default, in write they are written
  2044. * by default. Also the behavior of PNG_HANDLE_CHUNK_IF_SAFE is very different
  2045. * - on write the safe-to-copy bit is checked, on read the critical bit is
  2046. * checked and on read if the chunk is critical an error will be raised.
  2047. *
  2048. * num_chunks:
  2049. * ===========
  2050. * If num_chunks is positive, then the "keep" parameter specifies the manner
  2051. * for handling only those chunks appearing in the chunk_list array,
  2052. * otherwise the chunk list array is ignored.
  2053. *
  2054. * If num_chunks is 0 the "keep" parameter specifies the default behavior for
  2055. * unknown chunks, as described above.
  2056. *
  2057. * If num_chunks is negative, then the "keep" parameter specifies the manner
  2058. * for handling all unknown chunks plus all chunks recognized by libpng
  2059. * except for the IHDR, PLTE, tRNS, IDAT, and IEND chunks (which continue to
  2060. * be processed by libpng.
  2061. */
  2062. #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
  2063. PNG_EXPORT(172, void, png_set_keep_unknown_chunks, (png_structrp png_ptr,
  2064. int keep, png_const_bytep chunk_list, int num_chunks));
  2065. #endif /* HANDLE_AS_UNKNOWN */
  2066. /* The "keep" PNG_HANDLE_CHUNK_ parameter for the specified chunk is returned;
  2067. * the result is therefore true (non-zero) if special handling is required,
  2068. * false for the default handling.
  2069. */
  2070. PNG_EXPORT(173, int, png_handle_as_unknown, (png_const_structrp png_ptr,
  2071. png_const_bytep chunk_name));
  2072. #endif /* SET_UNKNOWN_CHUNKS */
  2073. #ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
  2074. PNG_EXPORT(174, void, png_set_unknown_chunks, (png_const_structrp png_ptr,
  2075. png_inforp info_ptr, png_const_unknown_chunkp unknowns,
  2076. int num_unknowns));
  2077. /* NOTE: prior to 1.6.0 this routine set the 'location' field of the added
  2078. * unknowns to the location currently stored in the png_struct. This is
  2079. * invariably the wrong value on write. To fix this call the following API
  2080. * for each chunk in the list with the correct location. If you know your
  2081. * code won't be compiled on earlier versions you can rely on
  2082. * png_set_unknown_chunks(write-ptr, png_get_unknown_chunks(read-ptr)) doing
  2083. * the correct thing.
  2084. */
  2085. PNG_EXPORT(175, void, png_set_unknown_chunk_location,
  2086. (png_const_structrp png_ptr, png_inforp info_ptr, int chunk, int location));
  2087. PNG_EXPORT(176, int, png_get_unknown_chunks, (png_const_structrp png_ptr,
  2088. png_inforp info_ptr, png_unknown_chunkpp entries));
  2089. #endif
  2090. /* Png_free_data() will turn off the "valid" flag for anything it frees.
  2091. * If you need to turn it off for a chunk that your application has freed,
  2092. * you can use png_set_invalid(png_ptr, info_ptr, PNG_INFO_CHNK);
  2093. */
  2094. PNG_EXPORT(177, void, png_set_invalid, (png_const_structrp png_ptr,
  2095. png_inforp info_ptr, int mask));
  2096. #ifdef PNG_INFO_IMAGE_SUPPORTED
  2097. /* The "params" pointer is currently not used and is for future expansion. */
  2098. #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
  2099. PNG_EXPORT(178, void, png_read_png, (png_structrp png_ptr, png_inforp info_ptr,
  2100. int transforms, png_voidp params));
  2101. #endif
  2102. #ifdef PNG_WRITE_SUPPORTED
  2103. PNG_EXPORT(179, void, png_write_png, (png_structrp png_ptr, png_inforp info_ptr,
  2104. int transforms, png_voidp params));
  2105. #endif
  2106. #endif
  2107. PNG_EXPORT(180, png_const_charp, png_get_copyright,
  2108. (png_const_structrp png_ptr));
  2109. PNG_EXPORT(181, png_const_charp, png_get_header_ver,
  2110. (png_const_structrp png_ptr));
  2111. PNG_EXPORT(182, png_const_charp, png_get_header_version,
  2112. (png_const_structrp png_ptr));
  2113. PNG_EXPORT(183, png_const_charp, png_get_libpng_ver,
  2114. (png_const_structrp png_ptr));
  2115. #ifdef PNG_MNG_FEATURES_SUPPORTED
  2116. PNG_EXPORT(184, png_uint_32, png_permit_mng_features, (png_structrp png_ptr,
  2117. png_uint_32 mng_features_permitted));
  2118. #endif
  2119. /* For use in png_set_keep_unknown, added to version 1.2.6 */
  2120. #define PNG_HANDLE_CHUNK_AS_DEFAULT 0
  2121. #define PNG_HANDLE_CHUNK_NEVER 1
  2122. #define PNG_HANDLE_CHUNK_IF_SAFE 2
  2123. #define PNG_HANDLE_CHUNK_ALWAYS 3
  2124. #define PNG_HANDLE_CHUNK_LAST 4
  2125. /* Strip the prepended error numbers ("#nnn ") from error and warning
  2126. * messages before passing them to the error or warning handler.
  2127. */
  2128. #ifdef PNG_ERROR_NUMBERS_SUPPORTED
  2129. PNG_EXPORT(185, void, png_set_strip_error_numbers, (png_structrp png_ptr,
  2130. png_uint_32 strip_mode));
  2131. #endif
  2132. /* Added in libpng-1.2.6 */
  2133. #ifdef PNG_SET_USER_LIMITS_SUPPORTED
  2134. PNG_EXPORT(186, void, png_set_user_limits, (png_structrp png_ptr,
  2135. png_uint_32 user_width_max, png_uint_32 user_height_max));
  2136. PNG_EXPORT(187, png_uint_32, png_get_user_width_max,
  2137. (png_const_structrp png_ptr));
  2138. PNG_EXPORT(188, png_uint_32, png_get_user_height_max,
  2139. (png_const_structrp png_ptr));
  2140. /* Added in libpng-1.4.0 */
  2141. PNG_EXPORT(189, void, png_set_chunk_cache_max, (png_structrp png_ptr,
  2142. png_uint_32 user_chunk_cache_max));
  2143. PNG_EXPORT(190, png_uint_32, png_get_chunk_cache_max,
  2144. (png_const_structrp png_ptr));
  2145. /* Added in libpng-1.4.1 */
  2146. PNG_EXPORT(191, void, png_set_chunk_malloc_max, (png_structrp png_ptr,
  2147. png_alloc_size_t user_chunk_cache_max));
  2148. PNG_EXPORT(192, png_alloc_size_t, png_get_chunk_malloc_max,
  2149. (png_const_structrp png_ptr));
  2150. #endif
  2151. #if defined(PNG_INCH_CONVERSIONS_SUPPORTED)
  2152. PNG_EXPORT(193, png_uint_32, png_get_pixels_per_inch,
  2153. (png_const_structrp png_ptr, png_const_inforp info_ptr));
  2154. PNG_EXPORT(194, png_uint_32, png_get_x_pixels_per_inch,
  2155. (png_const_structrp png_ptr, png_const_inforp info_ptr));
  2156. PNG_EXPORT(195, png_uint_32, png_get_y_pixels_per_inch,
  2157. (png_const_structrp png_ptr, png_const_inforp info_ptr));
  2158. PNG_FP_EXPORT(196, float, png_get_x_offset_inches,
  2159. (png_const_structrp png_ptr, png_const_inforp info_ptr))
  2160. #ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */
  2161. PNG_FIXED_EXPORT(211, png_fixed_point, png_get_x_offset_inches_fixed,
  2162. (png_const_structrp png_ptr, png_const_inforp info_ptr))
  2163. #endif
  2164. PNG_FP_EXPORT(197, float, png_get_y_offset_inches, (png_const_structrp png_ptr,
  2165. png_const_inforp info_ptr))
  2166. #ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */
  2167. PNG_FIXED_EXPORT(212, png_fixed_point, png_get_y_offset_inches_fixed,
  2168. (png_const_structrp png_ptr, png_const_inforp info_ptr))
  2169. #endif
  2170. # ifdef PNG_pHYs_SUPPORTED
  2171. PNG_EXPORT(198, png_uint_32, png_get_pHYs_dpi, (png_const_structrp png_ptr,
  2172. png_const_inforp info_ptr, png_uint_32 *res_x, png_uint_32 *res_y,
  2173. int *unit_type));
  2174. # endif /* pHYs */
  2175. #endif /* INCH_CONVERSIONS */
  2176. /* Added in libpng-1.4.0 */
  2177. #ifdef PNG_IO_STATE_SUPPORTED
  2178. PNG_EXPORT(199, png_uint_32, png_get_io_state, (png_const_structrp png_ptr));
  2179. /* Removed from libpng 1.6; use png_get_io_chunk_type. */
  2180. PNG_REMOVED(200, png_const_bytep, png_get_io_chunk_name, (png_structrp png_ptr),
  2181. PNG_DEPRECATED)
  2182. PNG_EXPORT(216, png_uint_32, png_get_io_chunk_type,
  2183. (png_const_structrp png_ptr));
  2184. /* The flags returned by png_get_io_state() are the following: */
  2185. # define PNG_IO_NONE 0x0000 /* no I/O at this moment */
  2186. # define PNG_IO_READING 0x0001 /* currently reading */
  2187. # define PNG_IO_WRITING 0x0002 /* currently writing */
  2188. # define PNG_IO_SIGNATURE 0x0010 /* currently at the file signature */
  2189. # define PNG_IO_CHUNK_HDR 0x0020 /* currently at the chunk header */
  2190. # define PNG_IO_CHUNK_DATA 0x0040 /* currently at the chunk data */
  2191. # define PNG_IO_CHUNK_CRC 0x0080 /* currently at the chunk crc */
  2192. # define PNG_IO_MASK_OP 0x000f /* current operation: reading/writing */
  2193. # define PNG_IO_MASK_LOC 0x00f0 /* current location: sig/hdr/data/crc */
  2194. #endif /* IO_STATE */
  2195. /* Interlace support. The following macros are always defined so that if
  2196. * libpng interlace handling is turned off the macros may be used to handle
  2197. * interlaced images within the application.
  2198. */
  2199. #define PNG_INTERLACE_ADAM7_PASSES 7
  2200. /* Two macros to return the first row and first column of the original,
  2201. * full, image which appears in a given pass. 'pass' is in the range 0
  2202. * to 6 and the result is in the range 0 to 7.
  2203. */
  2204. #define PNG_PASS_START_ROW(pass) (((1&~(pass))<<(3-((pass)>>1)))&7)
  2205. #define PNG_PASS_START_COL(pass) (((1& (pass))<<(3-(((pass)+1)>>1)))&7)
  2206. /* A macro to return the offset between pixels in the output row for a pair of
  2207. * pixels in the input - effectively the inverse of the 'COL_SHIFT' macro that
  2208. * follows. Note that ROW_OFFSET is the offset from one row to the next whereas
  2209. * COL_OFFSET is from one column to the next, within a row.
  2210. */
  2211. #define PNG_PASS_ROW_OFFSET(pass) ((pass)>2?(8>>(((pass)-1)>>1)):8)
  2212. #define PNG_PASS_COL_OFFSET(pass) (1<<((7-(pass))>>1))
  2213. /* Two macros to help evaluate the number of rows or columns in each
  2214. * pass. This is expressed as a shift - effectively log2 of the number or
  2215. * rows or columns in each 8x8 tile of the original image.
  2216. */
  2217. #define PNG_PASS_ROW_SHIFT(pass) ((pass)>2?(8-(pass))>>1:3)
  2218. #define PNG_PASS_COL_SHIFT(pass) ((pass)>1?(7-(pass))>>1:3)
  2219. /* Hence two macros to determine the number of rows or columns in a given
  2220. * pass of an image given its height or width. In fact these macros may
  2221. * return non-zero even though the sub-image is empty, because the other
  2222. * dimension may be empty for a small image.
  2223. */
  2224. #define PNG_PASS_ROWS(height, pass) (((height)+(((1<<PNG_PASS_ROW_SHIFT(pass))\
  2225. -1)-PNG_PASS_START_ROW(pass)))>>PNG_PASS_ROW_SHIFT(pass))
  2226. #define PNG_PASS_COLS(width, pass) (((width)+(((1<<PNG_PASS_COL_SHIFT(pass))\
  2227. -1)-PNG_PASS_START_COL(pass)))>>PNG_PASS_COL_SHIFT(pass))
  2228. /* For the reader row callbacks (both progressive and sequential) it is
  2229. * necessary to find the row in the output image given a row in an interlaced
  2230. * image, so two more macros:
  2231. */
  2232. #define PNG_ROW_FROM_PASS_ROW(y_in, pass) \
  2233. (((y_in)<<PNG_PASS_ROW_SHIFT(pass))+PNG_PASS_START_ROW(pass))
  2234. #define PNG_COL_FROM_PASS_COL(x_in, pass) \
  2235. (((x_in)<<PNG_PASS_COL_SHIFT(pass))+PNG_PASS_START_COL(pass))
  2236. /* Two macros which return a boolean (0 or 1) saying whether the given row
  2237. * or column is in a particular pass. These use a common utility macro that
  2238. * returns a mask for a given pass - the offset 'off' selects the row or
  2239. * column version. The mask has the appropriate bit set for each column in
  2240. * the tile.
  2241. */
  2242. #define PNG_PASS_MASK(pass,off) ( \
  2243. ((0x110145AF>>(((7-(off))-(pass))<<2)) & 0xF) | \
  2244. ((0x01145AF0>>(((7-(off))-(pass))<<2)) & 0xF0))
  2245. #define PNG_ROW_IN_INTERLACE_PASS(y, pass) \
  2246. ((PNG_PASS_MASK(pass,0) >> ((y)&7)) & 1)
  2247. #define PNG_COL_IN_INTERLACE_PASS(x, pass) \
  2248. ((PNG_PASS_MASK(pass,1) >> ((x)&7)) & 1)
  2249. #ifdef PNG_READ_COMPOSITE_NODIV_SUPPORTED
  2250. /* With these routines we avoid an integer divide, which will be slower on
  2251. * most machines. However, it does take more operations than the corresponding
  2252. * divide method, so it may be slower on a few RISC systems. There are two
  2253. * shifts (by 8 or 16 bits) and an addition, versus a single integer divide.
  2254. *
  2255. * Note that the rounding factors are NOT supposed to be the same! 128 and
  2256. * 32768 are correct for the NODIV code; 127 and 32767 are correct for the
  2257. * standard method.
  2258. *
  2259. * [Optimized code by Greg Roelofs and Mark Adler...blame us for bugs. :-) ]
  2260. */
  2261. /* fg and bg should be in `gamma 1.0' space; alpha is the opacity */
  2262. # define png_composite(composite, fg, alpha, bg) \
  2263. { \
  2264. png_uint_16 temp = (png_uint_16)((png_uint_16)(fg) \
  2265. * (png_uint_16)(alpha) \
  2266. + (png_uint_16)(bg)*(png_uint_16)(255 \
  2267. - (png_uint_16)(alpha)) + 128); \
  2268. (composite) = (png_byte)(((temp + (temp >> 8)) >> 8) & 0xff); \
  2269. }
  2270. # define png_composite_16(composite, fg, alpha, bg) \
  2271. { \
  2272. png_uint_32 temp = (png_uint_32)((png_uint_32)(fg) \
  2273. * (png_uint_32)(alpha) \
  2274. + (png_uint_32)(bg)*(65535 \
  2275. - (png_uint_32)(alpha)) + 32768); \
  2276. (composite) = (png_uint_16)(0xffff & ((temp + (temp >> 16)) >> 16)); \
  2277. }
  2278. #else /* Standard method using integer division */
  2279. # define png_composite(composite, fg, alpha, bg) \
  2280. (composite) = \
  2281. (png_byte)(0xff & (((png_uint_16)(fg) * (png_uint_16)(alpha) + \
  2282. (png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) + \
  2283. 127) / 255))
  2284. # define png_composite_16(composite, fg, alpha, bg) \
  2285. (composite) = \
  2286. (png_uint_16)(0xffff & (((png_uint_32)(fg) * (png_uint_32)(alpha) + \
  2287. (png_uint_32)(bg)*(png_uint_32)(65535 - (png_uint_32)(alpha)) + \
  2288. 32767) / 65535))
  2289. #endif /* READ_COMPOSITE_NODIV */
  2290. #ifdef PNG_READ_INT_FUNCTIONS_SUPPORTED
  2291. PNG_EXPORT(201, png_uint_32, png_get_uint_32, (png_const_bytep buf));
  2292. PNG_EXPORT(202, png_uint_16, png_get_uint_16, (png_const_bytep buf));
  2293. PNG_EXPORT(203, png_int_32, png_get_int_32, (png_const_bytep buf));
  2294. #endif
  2295. PNG_EXPORT(204, png_uint_32, png_get_uint_31, (png_const_structrp png_ptr,
  2296. png_const_bytep buf));
  2297. /* No png_get_int_16 -- may be added if there's a real need for it. */
  2298. /* Place a 32-bit number into a buffer in PNG byte order (big-endian). */
  2299. #ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED
  2300. PNG_EXPORT(205, void, png_save_uint_32, (png_bytep buf, png_uint_32 i));
  2301. #endif
  2302. #ifdef PNG_SAVE_INT_32_SUPPORTED
  2303. PNG_EXPORT(206, void, png_save_int_32, (png_bytep buf, png_int_32 i));
  2304. #endif
  2305. /* Place a 16-bit number into a buffer in PNG byte order.
  2306. * The parameter is declared unsigned int, not png_uint_16,
  2307. * just to avoid potential problems on pre-ANSI C compilers.
  2308. */
  2309. #ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED
  2310. PNG_EXPORT(207, void, png_save_uint_16, (png_bytep buf, unsigned int i));
  2311. /* No png_save_int_16 -- may be added if there's a real need for it. */
  2312. #endif
  2313. #ifdef PNG_USE_READ_MACROS
  2314. /* Inline macros to do direct reads of bytes from the input buffer.
  2315. * The png_get_int_32() routine assumes we are using two's complement
  2316. * format for negative values, which is almost certainly true.
  2317. */
  2318. # define PNG_get_uint_32(buf) \
  2319. (((png_uint_32)(*(buf)) << 24) + \
  2320. ((png_uint_32)(*((buf) + 1)) << 16) + \
  2321. ((png_uint_32)(*((buf) + 2)) << 8) + \
  2322. ((png_uint_32)(*((buf) + 3))))
  2323. /* From libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the
  2324. * function) incorrectly returned a value of type png_uint_32.
  2325. */
  2326. # define PNG_get_uint_16(buf) \
  2327. ((png_uint_16) \
  2328. (((unsigned int)(*(buf)) << 8) + \
  2329. ((unsigned int)(*((buf) + 1)))))
  2330. # define PNG_get_int_32(buf) \
  2331. ((png_int_32)((*(buf) & 0x80) \
  2332. ? -((png_int_32)(((png_get_uint_32(buf)^0xffffffffU)+1U)&0x7fffffffU)) \
  2333. : (png_int_32)png_get_uint_32(buf)))
  2334. /* If PNG_PREFIX is defined the same thing as below happens in pnglibconf.h,
  2335. * but defining a macro name prefixed with PNG_PREFIX.
  2336. */
  2337. # ifndef PNG_PREFIX
  2338. # define png_get_uint_32(buf) PNG_get_uint_32(buf)
  2339. # define png_get_uint_16(buf) PNG_get_uint_16(buf)
  2340. # define png_get_int_32(buf) PNG_get_int_32(buf)
  2341. # endif
  2342. #else
  2343. # ifdef PNG_PREFIX
  2344. /* No macros; revert to the (redefined) function */
  2345. # define PNG_get_uint_32 (png_get_uint_32)
  2346. # define PNG_get_uint_16 (png_get_uint_16)
  2347. # define PNG_get_int_32 (png_get_int_32)
  2348. # endif
  2349. #endif
  2350. #ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED
  2351. PNG_EXPORT(242, void, png_set_check_for_invalid_index,
  2352. (png_structrp png_ptr, int allowed));
  2353. # ifdef PNG_GET_PALETTE_MAX_SUPPORTED
  2354. PNG_EXPORT(243, int, png_get_palette_max, (png_const_structp png_ptr,
  2355. png_const_infop info_ptr));
  2356. # endif
  2357. #endif /* CHECK_FOR_INVALID_INDEX */
  2358. /*******************************************************************************
  2359. * Section 5: SIMPLIFIED API
  2360. *******************************************************************************
  2361. *
  2362. * Please read the documentation in libpng-manual.txt (TODO: write said
  2363. * documentation) if you don't understand what follows.
  2364. *
  2365. * The simplified API hides the details of both libpng and the PNG file format
  2366. * itself. It allows PNG files to be read into a very limited number of
  2367. * in-memory bitmap formats or to be written from the same formats. If these
  2368. * formats do not accomodate your needs then you can, and should, use the more
  2369. * sophisticated APIs above - these support a wide variety of in-memory formats
  2370. * and a wide variety of sophisticated transformations to those formats as well
  2371. * as a wide variety of APIs to manipulate ancillary information.
  2372. *
  2373. * To read a PNG file using the simplified API:
  2374. *
  2375. * 1) Declare a 'png_image' structure (see below) on the stack, set the
  2376. * version field to PNG_IMAGE_VERSION and the 'opaque' pointer to NULL
  2377. * (this is REQUIRED, your program may crash if you don't do it.)
  2378. * 2) Call the appropriate png_image_begin_read... function.
  2379. * 3) Set the png_image 'format' member to the required sample format.
  2380. * 4) Allocate a buffer for the image and, if required, the color-map.
  2381. * 5) Call png_image_finish_read to read the image and, if required, the
  2382. * color-map into your buffers.
  2383. *
  2384. * There are no restrictions on the format of the PNG input itself; all valid
  2385. * color types, bit depths, and interlace methods are acceptable, and the
  2386. * input image is transformed as necessary to the requested in-memory format
  2387. * during the png_image_finish_read() step. The only caveat is that if you
  2388. * request a color-mapped image from a PNG that is full-color or makes
  2389. * complex use of an alpha channel the transformation is extremely lossy and the
  2390. * result may look terrible.
  2391. *
  2392. * To write a PNG file using the simplified API:
  2393. *
  2394. * 1) Declare a 'png_image' structure on the stack and memset() it to all zero.
  2395. * 2) Initialize the members of the structure that describe the image, setting
  2396. * the 'format' member to the format of the image samples.
  2397. * 3) Call the appropriate png_image_write... function with a pointer to the
  2398. * image and, if necessary, the color-map to write the PNG data.
  2399. *
  2400. * png_image is a structure that describes the in-memory format of an image
  2401. * when it is being read or defines the in-memory format of an image that you
  2402. * need to write:
  2403. */
  2404. #if defined(PNG_SIMPLIFIED_READ_SUPPORTED) || \
  2405. defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
  2406. #define PNG_IMAGE_VERSION 1
  2407. typedef struct png_control *png_controlp;
  2408. typedef struct
  2409. {
  2410. png_controlp opaque; /* Initialize to NULL, free with png_image_free */
  2411. png_uint_32 version; /* Set to PNG_IMAGE_VERSION */
  2412. png_uint_32 width; /* Image width in pixels (columns) */
  2413. png_uint_32 height; /* Image height in pixels (rows) */
  2414. png_uint_32 format; /* Image format as defined below */
  2415. png_uint_32 flags; /* A bit mask containing informational flags */
  2416. png_uint_32 colormap_entries;
  2417. /* Number of entries in the color-map */
  2418. /* In the event of an error or warning the following field will be set to a
  2419. * non-zero value and the 'message' field will contain a '\0' terminated
  2420. * string with the libpng error or warning message. If both warnings and
  2421. * an error were encountered, only the error is recorded. If there
  2422. * are multiple warnings, only the first one is recorded.
  2423. *
  2424. * The upper 30 bits of this value are reserved, the low two bits contain
  2425. * a value as follows:
  2426. */
  2427. # define PNG_IMAGE_WARNING 1
  2428. # define PNG_IMAGE_ERROR 2
  2429. /*
  2430. * The result is a two-bit code such that a value more than 1 indicates
  2431. * a failure in the API just called:
  2432. *
  2433. * 0 - no warning or error
  2434. * 1 - warning
  2435. * 2 - error
  2436. * 3 - error preceded by warning
  2437. */
  2438. # define PNG_IMAGE_FAILED(png_cntrl) ((((png_cntrl).warning_or_error)&0x03)>1)
  2439. png_uint_32 warning_or_error;
  2440. char message[64];
  2441. } png_image, *png_imagep;
  2442. /* The samples of the image have one to four channels whose components have
  2443. * original values in the range 0 to 1.0:
  2444. *
  2445. * 1: A single gray or luminance channel (G).
  2446. * 2: A gray/luminance channel and an alpha channel (GA).
  2447. * 3: Three red, green, blue color channels (RGB).
  2448. * 4: Three color channels and an alpha channel (RGBA).
  2449. *
  2450. * The components are encoded in one of two ways:
  2451. *
  2452. * a) As a small integer, value 0..255, contained in a single byte. For the
  2453. * alpha channel the original value is simply value/255. For the color or
  2454. * luminance channels the value is encoded according to the sRGB specification
  2455. * and matches the 8-bit format expected by typical display devices.
  2456. *
  2457. * The color/gray channels are not scaled (pre-multiplied) by the alpha
  2458. * channel and are suitable for passing to color management software.
  2459. *
  2460. * b) As a value in the range 0..65535, contained in a 2-byte integer. All
  2461. * channels can be converted to the original value by dividing by 65535; all
  2462. * channels are linear. Color channels use the RGB encoding (RGB end-points) of
  2463. * the sRGB specification. This encoding is identified by the
  2464. * PNG_FORMAT_FLAG_LINEAR flag below.
  2465. *
  2466. * When the simplified API needs to convert between sRGB and linear colorspaces,
  2467. * the actual sRGB transfer curve defined in the sRGB specification (see the
  2468. * article at https://en.wikipedia.org/wiki/SRGB) is used, not the gamma=1/2.2
  2469. * approximation used elsewhere in libpng.
  2470. *
  2471. * When an alpha channel is present it is expected to denote pixel coverage
  2472. * of the color or luminance channels and is returned as an associated alpha
  2473. * channel: the color/gray channels are scaled (pre-multiplied) by the alpha
  2474. * value.
  2475. *
  2476. * The samples are either contained directly in the image data, between 1 and 8
  2477. * bytes per pixel according to the encoding, or are held in a color-map indexed
  2478. * by bytes in the image data. In the case of a color-map the color-map entries
  2479. * are individual samples, encoded as above, and the image data has one byte per
  2480. * pixel to select the relevant sample from the color-map.
  2481. */
  2482. /* PNG_FORMAT_*
  2483. *
  2484. * #defines to be used in png_image::format. Each #define identifies a
  2485. * particular layout of sample data and, if present, alpha values. There are
  2486. * separate defines for each of the two component encodings.
  2487. *
  2488. * A format is built up using single bit flag values. All combinations are
  2489. * valid. Formats can be built up from the flag values or you can use one of
  2490. * the predefined values below. When testing formats always use the FORMAT_FLAG
  2491. * macros to test for individual features - future versions of the library may
  2492. * add new flags.
  2493. *
  2494. * When reading or writing color-mapped images the format should be set to the
  2495. * format of the entries in the color-map then png_image_{read,write}_colormap
  2496. * called to read or write the color-map and set the format correctly for the
  2497. * image data. Do not set the PNG_FORMAT_FLAG_COLORMAP bit directly!
  2498. *
  2499. * NOTE: libpng can be built with particular features disabled. If you see
  2500. * compiler errors because the definition of one of the following flags has been
  2501. * compiled out it is because libpng does not have the required support. It is
  2502. * possible, however, for the libpng configuration to enable the format on just
  2503. * read or just write; in that case you may see an error at run time. You can
  2504. * guard against this by checking for the definition of the appropriate
  2505. * "_SUPPORTED" macro, one of:
  2506. *
  2507. * PNG_SIMPLIFIED_{READ,WRITE}_{BGR,AFIRST}_SUPPORTED
  2508. */
  2509. #define PNG_FORMAT_FLAG_ALPHA 0x01U /* format with an alpha channel */
  2510. #define PNG_FORMAT_FLAG_COLOR 0x02U /* color format: otherwise grayscale */
  2511. #define PNG_FORMAT_FLAG_LINEAR 0x04U /* 2-byte channels else 1-byte */
  2512. #define PNG_FORMAT_FLAG_COLORMAP 0x08U /* image data is color-mapped */
  2513. #ifdef PNG_FORMAT_BGR_SUPPORTED
  2514. # define PNG_FORMAT_FLAG_BGR 0x10U /* BGR colors, else order is RGB */
  2515. #endif
  2516. #ifdef PNG_FORMAT_AFIRST_SUPPORTED
  2517. # define PNG_FORMAT_FLAG_AFIRST 0x20U /* alpha channel comes first */
  2518. #endif
  2519. #define PNG_FORMAT_FLAG_ASSOCIATED_ALPHA 0x40U /* alpha channel is associated */
  2520. /* Commonly used formats have predefined macros.
  2521. *
  2522. * First the single byte (sRGB) formats:
  2523. */
  2524. #define PNG_FORMAT_GRAY 0
  2525. #define PNG_FORMAT_GA PNG_FORMAT_FLAG_ALPHA
  2526. #define PNG_FORMAT_AG (PNG_FORMAT_GA|PNG_FORMAT_FLAG_AFIRST)
  2527. #define PNG_FORMAT_RGB PNG_FORMAT_FLAG_COLOR
  2528. #define PNG_FORMAT_BGR (PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_BGR)
  2529. #define PNG_FORMAT_RGBA (PNG_FORMAT_RGB|PNG_FORMAT_FLAG_ALPHA)
  2530. #define PNG_FORMAT_ARGB (PNG_FORMAT_RGBA|PNG_FORMAT_FLAG_AFIRST)
  2531. #define PNG_FORMAT_BGRA (PNG_FORMAT_BGR|PNG_FORMAT_FLAG_ALPHA)
  2532. #define PNG_FORMAT_ABGR (PNG_FORMAT_BGRA|PNG_FORMAT_FLAG_AFIRST)
  2533. /* Then the linear 2-byte formats. When naming these "Y" is used to
  2534. * indicate a luminance (gray) channel.
  2535. */
  2536. #define PNG_FORMAT_LINEAR_Y PNG_FORMAT_FLAG_LINEAR
  2537. #define PNG_FORMAT_LINEAR_Y_ALPHA (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_ALPHA)
  2538. #define PNG_FORMAT_LINEAR_RGB (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR)
  2539. #define PNG_FORMAT_LINEAR_RGB_ALPHA \
  2540. (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_ALPHA)
  2541. /* With color-mapped formats the image data is one byte for each pixel, the byte
  2542. * is an index into the color-map which is formatted as above. To obtain a
  2543. * color-mapped format it is sufficient just to add the PNG_FOMAT_FLAG_COLORMAP
  2544. * to one of the above definitions, or you can use one of the definitions below.
  2545. */
  2546. #define PNG_FORMAT_RGB_COLORMAP (PNG_FORMAT_RGB|PNG_FORMAT_FLAG_COLORMAP)
  2547. #define PNG_FORMAT_BGR_COLORMAP (PNG_FORMAT_BGR|PNG_FORMAT_FLAG_COLORMAP)
  2548. #define PNG_FORMAT_RGBA_COLORMAP (PNG_FORMAT_RGBA|PNG_FORMAT_FLAG_COLORMAP)
  2549. #define PNG_FORMAT_ARGB_COLORMAP (PNG_FORMAT_ARGB|PNG_FORMAT_FLAG_COLORMAP)
  2550. #define PNG_FORMAT_BGRA_COLORMAP (PNG_FORMAT_BGRA|PNG_FORMAT_FLAG_COLORMAP)
  2551. #define PNG_FORMAT_ABGR_COLORMAP (PNG_FORMAT_ABGR|PNG_FORMAT_FLAG_COLORMAP)
  2552. /* PNG_IMAGE macros
  2553. *
  2554. * These are convenience macros to derive information from a png_image
  2555. * structure. The PNG_IMAGE_SAMPLE_ macros return values appropriate to the
  2556. * actual image sample values - either the entries in the color-map or the
  2557. * pixels in the image. The PNG_IMAGE_PIXEL_ macros return corresponding values
  2558. * for the pixels and will always return 1 for color-mapped formats. The
  2559. * remaining macros return information about the rows in the image and the
  2560. * complete image.
  2561. *
  2562. * NOTE: All the macros that take a png_image::format parameter are compile time
  2563. * constants if the format parameter is, itself, a constant. Therefore these
  2564. * macros can be used in array declarations and case labels where required.
  2565. * Similarly the macros are also pre-processor constants (sizeof is not used) so
  2566. * they can be used in #if tests.
  2567. *
  2568. * First the information about the samples.
  2569. */
  2570. #define PNG_IMAGE_SAMPLE_CHANNELS(fmt)\
  2571. (((fmt)&(PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_ALPHA))+1)
  2572. /* Return the total number of channels in a given format: 1..4 */
  2573. #define PNG_IMAGE_SAMPLE_COMPONENT_SIZE(fmt)\
  2574. ((((fmt) & PNG_FORMAT_FLAG_LINEAR) >> 2)+1)
  2575. /* Return the size in bytes of a single component of a pixel or color-map
  2576. * entry (as appropriate) in the image: 1 or 2.
  2577. */
  2578. #define PNG_IMAGE_SAMPLE_SIZE(fmt)\
  2579. (PNG_IMAGE_SAMPLE_CHANNELS(fmt) * PNG_IMAGE_SAMPLE_COMPONENT_SIZE(fmt))
  2580. /* This is the size of the sample data for one sample. If the image is
  2581. * color-mapped it is the size of one color-map entry (and image pixels are
  2582. * one byte in size), otherwise it is the size of one image pixel.
  2583. */
  2584. #define PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(fmt)\
  2585. (PNG_IMAGE_SAMPLE_CHANNELS(fmt) * 256)
  2586. /* The maximum size of the color-map required by the format expressed in a
  2587. * count of components. This can be used to compile-time allocate a
  2588. * color-map:
  2589. *
  2590. * png_uint_16 colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(linear_fmt)];
  2591. *
  2592. * png_byte colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(sRGB_fmt)];
  2593. *
  2594. * Alternatively use the PNG_IMAGE_COLORMAP_SIZE macro below to use the
  2595. * information from one of the png_image_begin_read_ APIs and dynamically
  2596. * allocate the required memory.
  2597. */
  2598. /* Corresponding information about the pixels */
  2599. #define PNG_IMAGE_PIXEL_(test,fmt)\
  2600. (((fmt)&PNG_FORMAT_FLAG_COLORMAP)?1:test(fmt))
  2601. #define PNG_IMAGE_PIXEL_CHANNELS(fmt)\
  2602. PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_CHANNELS,fmt)
  2603. /* The number of separate channels (components) in a pixel; 1 for a
  2604. * color-mapped image.
  2605. */
  2606. #define PNG_IMAGE_PIXEL_COMPONENT_SIZE(fmt)\
  2607. PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_COMPONENT_SIZE,fmt)
  2608. /* The size, in bytes, of each component in a pixel; 1 for a color-mapped
  2609. * image.
  2610. */
  2611. #define PNG_IMAGE_PIXEL_SIZE(fmt) PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_SIZE,fmt)
  2612. /* The size, in bytes, of a complete pixel; 1 for a color-mapped image. */
  2613. /* Information about the whole row, or whole image */
  2614. #define PNG_IMAGE_ROW_STRIDE(image)\
  2615. (PNG_IMAGE_PIXEL_CHANNELS((image).format) * (image).width)
  2616. /* Return the total number of components in a single row of the image; this
  2617. * is the minimum 'row stride', the minimum count of components between each
  2618. * row. For a color-mapped image this is the minimum number of bytes in a
  2619. * row.
  2620. *
  2621. * WARNING: this macro overflows for some images with more than one component
  2622. * and very large image widths. libpng will refuse to process an image where
  2623. * this macro would overflow.
  2624. */
  2625. #define PNG_IMAGE_BUFFER_SIZE(image, row_stride)\
  2626. (PNG_IMAGE_PIXEL_COMPONENT_SIZE((image).format)*(image).height*(row_stride))
  2627. /* Return the size, in bytes, of an image buffer given a png_image and a row
  2628. * stride - the number of components to leave space for in each row.
  2629. *
  2630. * WARNING: this macro overflows a 32-bit integer for some large PNG images,
  2631. * libpng will refuse to process an image where such an overflow would occur.
  2632. */
  2633. #define PNG_IMAGE_SIZE(image)\
  2634. PNG_IMAGE_BUFFER_SIZE(image, PNG_IMAGE_ROW_STRIDE(image))
  2635. /* Return the size, in bytes, of the image in memory given just a png_image;
  2636. * the row stride is the minimum stride required for the image.
  2637. */
  2638. #define PNG_IMAGE_COLORMAP_SIZE(image)\
  2639. (PNG_IMAGE_SAMPLE_SIZE((image).format) * (image).colormap_entries)
  2640. /* Return the size, in bytes, of the color-map of this image. If the image
  2641. * format is not a color-map format this will return a size sufficient for
  2642. * 256 entries in the given format; check PNG_FORMAT_FLAG_COLORMAP if
  2643. * you don't want to allocate a color-map in this case.
  2644. */
  2645. /* PNG_IMAGE_FLAG_*
  2646. *
  2647. * Flags containing additional information about the image are held in the
  2648. * 'flags' field of png_image.
  2649. */
  2650. #define PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB 0x01
  2651. /* This indicates the the RGB values of the in-memory bitmap do not
  2652. * correspond to the red, green and blue end-points defined by sRGB.
  2653. */
  2654. #define PNG_IMAGE_FLAG_FAST 0x02
  2655. /* On write emphasise speed over compression; the resultant PNG file will be
  2656. * larger but will be produced significantly faster, particular for large
  2657. * images. Do not use this option for images which will be distributed, only
  2658. * used it when producing intermediate files that will be read back in
  2659. * repeatedly. For a typical 24-bit image the option will double the read
  2660. * speed at the cost of increasing the image size by 25%, however for many
  2661. * more compressible images the PNG file can be 10 times larger with only a
  2662. * slight speed gain.
  2663. */
  2664. #define PNG_IMAGE_FLAG_16BIT_sRGB 0x04
  2665. /* On read if the image is a 16-bit per component image and there is no gAMA
  2666. * or sRGB chunk assume that the components are sRGB encoded. Notice that
  2667. * images output by the simplified API always have gamma information; setting
  2668. * this flag only affects the interpretation of 16-bit images from an
  2669. * external source. It is recommended that the application expose this flag
  2670. * to the user; the user can normally easily recognize the difference between
  2671. * linear and sRGB encoding. This flag has no effect on write - the data
  2672. * passed to the write APIs must have the correct encoding (as defined
  2673. * above.)
  2674. *
  2675. * If the flag is not set (the default) input 16-bit per component data is
  2676. * assumed to be linear.
  2677. *
  2678. * NOTE: the flag can only be set after the png_image_begin_read_ call,
  2679. * because that call initializes the 'flags' field.
  2680. */
  2681. #ifdef PNG_SIMPLIFIED_READ_SUPPORTED
  2682. /* READ APIs
  2683. * ---------
  2684. *
  2685. * The png_image passed to the read APIs must have been initialized by setting
  2686. * the png_controlp field 'opaque' to NULL (or, safer, memset the whole thing.)
  2687. */
  2688. #ifdef PNG_STDIO_SUPPORTED
  2689. PNG_EXPORT(234, int, png_image_begin_read_from_file, (png_imagep image,
  2690. const char *file_name));
  2691. /* The named file is opened for read and the image header is filled in
  2692. * from the PNG header in the file.
  2693. */
  2694. PNG_EXPORT(235, int, png_image_begin_read_from_stdio, (png_imagep image,
  2695. FILE* file));
  2696. /* The PNG header is read from the stdio FILE object. */
  2697. #endif /* STDIO */
  2698. PNG_EXPORT(236, int, png_image_begin_read_from_memory, (png_imagep image,
  2699. png_const_voidp memory, png_size_t size));
  2700. /* The PNG header is read from the given memory buffer. */
  2701. PNG_EXPORT(237, int, png_image_finish_read, (png_imagep image,
  2702. png_const_colorp background, void *buffer, png_int_32 row_stride,
  2703. void *colormap));
  2704. /* Finish reading the image into the supplied buffer and clean up the
  2705. * png_image structure.
  2706. *
  2707. * row_stride is the step, in byte or 2-byte units as appropriate,
  2708. * between adjacent rows. A positive stride indicates that the top-most row
  2709. * is first in the buffer - the normal top-down arrangement. A negative
  2710. * stride indicates that the bottom-most row is first in the buffer.
  2711. *
  2712. * background need only be supplied if an alpha channel must be removed from
  2713. * a png_byte format and the removal is to be done by compositing on a solid
  2714. * color; otherwise it may be NULL and any composition will be done directly
  2715. * onto the buffer. The value is an sRGB color to use for the background,
  2716. * for grayscale output the green channel is used.
  2717. *
  2718. * background must be supplied when an alpha channel must be removed from a
  2719. * single byte color-mapped output format, in other words if:
  2720. *
  2721. * 1) The original format from png_image_begin_read_from_* had
  2722. * PNG_FORMAT_FLAG_ALPHA set.
  2723. * 2) The format set by the application does not.
  2724. * 3) The format set by the application has PNG_FORMAT_FLAG_COLORMAP set and
  2725. * PNG_FORMAT_FLAG_LINEAR *not* set.
  2726. *
  2727. * For linear output removing the alpha channel is always done by compositing
  2728. * on black and background is ignored.
  2729. *
  2730. * colormap must be supplied when PNG_FORMAT_FLAG_COLORMAP is set. It must
  2731. * be at least the size (in bytes) returned by PNG_IMAGE_COLORMAP_SIZE.
  2732. * image->colormap_entries will be updated to the actual number of entries
  2733. * written to the colormap; this may be less than the original value.
  2734. */
  2735. PNG_EXPORT(238, void, png_image_free, (png_imagep image));
  2736. /* Free any data allocated by libpng in image->opaque, setting the pointer to
  2737. * NULL. May be called at any time after the structure is initialized.
  2738. */
  2739. #endif /* SIMPLIFIED_READ */
  2740. #ifdef PNG_SIMPLIFIED_WRITE_SUPPORTED
  2741. /* WRITE APIS
  2742. * ----------
  2743. * For write you must initialize a png_image structure to describe the image to
  2744. * be written. To do this use memset to set the whole structure to 0 then
  2745. * initialize fields describing your image.
  2746. *
  2747. * version: must be set to PNG_IMAGE_VERSION
  2748. * opaque: must be initialized to NULL
  2749. * width: image width in pixels
  2750. * height: image height in rows
  2751. * format: the format of the data (image and color-map) you wish to write
  2752. * flags: set to 0 unless one of the defined flags applies; set
  2753. * PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB for color format images where the RGB
  2754. * values do not correspond to the colors in sRGB.
  2755. * colormap_entries: set to the number of entries in the color-map (0 to 256)
  2756. */
  2757. #ifdef PNG_SIMPLIFIED_WRITE_STDIO_SUPPORTED
  2758. PNG_EXPORT(239, int, png_image_write_to_file, (png_imagep image,
  2759. const char *file, int convert_to_8bit, const void *buffer,
  2760. png_int_32 row_stride, const void *colormap));
  2761. /* Write the image to the named file. */
  2762. PNG_EXPORT(240, int, png_image_write_to_stdio, (png_imagep image, FILE *file,
  2763. int convert_to_8_bit, const void *buffer, png_int_32 row_stride,
  2764. const void *colormap));
  2765. /* Write the image to the given (FILE*). */
  2766. #endif /* SIMPLIFIED_WRITE_STDIO */
  2767. /* With all write APIs if image is in one of the linear formats with 16-bit
  2768. * data then setting convert_to_8_bit will cause the output to be an 8-bit PNG
  2769. * gamma encoded according to the sRGB specification, otherwise a 16-bit linear
  2770. * encoded PNG file is written.
  2771. *
  2772. * With color-mapped data formats the colormap parameter point to a color-map
  2773. * with at least image->colormap_entries encoded in the specified format. If
  2774. * the format is linear the written PNG color-map will be converted to sRGB
  2775. * regardless of the convert_to_8_bit flag.
  2776. *
  2777. * With all APIs row_stride is handled as in the read APIs - it is the spacing
  2778. * from one row to the next in component sized units (1 or 2 bytes) and if
  2779. * negative indicates a bottom-up row layout in the buffer. If row_stride is
  2780. * zero, libpng will calculate it for you from the image width and number of
  2781. * channels.
  2782. *
  2783. * Note that the write API does not support interlacing, sub-8-bit pixels or
  2784. * most ancillary chunks. If you need to write text chunks (e.g. for copyright
  2785. * notices) you need to use one of the other APIs.
  2786. */
  2787. PNG_EXPORT(245, int, png_image_write_to_memory, (png_imagep image, void *memory,
  2788. png_alloc_size_t * PNG_RESTRICT memory_bytes, int convert_to_8_bit,
  2789. const void *buffer, png_int_32 row_stride, const void *colormap));
  2790. /* Write the image to the given memory buffer. The function both writes the
  2791. * whole PNG data stream to *memory and updates *memory_bytes with the count
  2792. * of bytes written.
  2793. *
  2794. * 'memory' may be NULL. In this case *memory_bytes is not read however on
  2795. * success the number of bytes which would have been written will still be
  2796. * stored in *memory_bytes. On failure *memory_bytes will contain 0.
  2797. *
  2798. * If 'memory' is not NULL it must point to memory[*memory_bytes] of
  2799. * writeable memory.
  2800. *
  2801. * If the function returns success memory[*memory_bytes] (if 'memory' is not
  2802. * NULL) contains the written PNG data. *memory_bytes will always be less
  2803. * than or equal to the original value.
  2804. *
  2805. * If the function returns false and *memory_bytes was not changed an error
  2806. * occured during write. If *memory_bytes was changed, or is not 0 if
  2807. * 'memory' was NULL, the write would have succeeded but for the memory
  2808. * buffer being too small. *memory_bytes contains the required number of
  2809. * bytes and will be bigger that the original value.
  2810. */
  2811. #define png_image_write_get_memory_size(image, size, convert_to_8_bit, buffer,\
  2812. row_stride, colormap)\
  2813. png_image_write_to_memory(&(image), 0, &(size), convert_to_8_bit, buffer,\
  2814. row_stride, colormap)
  2815. /* Return the amount of memory in 'size' required to compress this image.
  2816. * The png_image structure 'image' must be filled in as in the above
  2817. * function and must not be changed before the actual write call, the buffer
  2818. * and all other parameters must also be identical to that in the final
  2819. * write call. The 'size' variable need not be initialized.
  2820. *
  2821. * NOTE: the macro returns true/false, if false is returned 'size' will be
  2822. * set to zero and the write failed and probably will fail if tried again.
  2823. */
  2824. /* You can pre-allocate the buffer by making sure it is of sufficient size
  2825. * regardless of the amount of compression achieved. The buffer size will
  2826. * always be bigger than the original image and it will never be filled. The
  2827. * following macros are provided to assist in allocating the buffer.
  2828. */
  2829. #define PNG_IMAGE_DATA_SIZE(image) (PNG_IMAGE_SIZE(image)+(image).height)
  2830. /* The number of uncompressed bytes in the PNG byte encoding of the image;
  2831. * uncompressing the PNG IDAT data will give this number of bytes.
  2832. *
  2833. * NOTE: while PNG_IMAGE_SIZE cannot overflow for an image in memory this
  2834. * macro can because of the extra bytes used in the PNG byte encoding. You
  2835. * need to avoid this macro if your image size approaches 2^30 in width or
  2836. * height. The same goes for the remainder of these macros; they all produce
  2837. * bigger numbers than the actual in-memory image size.
  2838. */
  2839. #ifndef PNG_ZLIB_MAX_SIZE
  2840. # define PNG_ZLIB_MAX_SIZE(b) ((b)+(((b)+7U)>>3)+(((b)+63U)>>6)+11U)
  2841. /* An upper bound on the number of compressed bytes given 'b' uncompressed
  2842. * bytes. This is based on deflateBounds() in zlib; different
  2843. * implementations of zlib compression may conceivably produce more data so
  2844. * if your zlib implementation is not zlib itself redefine this macro
  2845. * appropriately.
  2846. */
  2847. #endif
  2848. #define PNG_IMAGE_COMPRESSED_SIZE_MAX(image)\
  2849. PNG_ZLIB_MAX_SIZE((png_alloc_size_t)PNG_IMAGE_DATA_SIZE(image))
  2850. /* An upper bound on the size of the data in the PNG IDAT chunks. */
  2851. #define PNG_IMAGE_PNG_SIZE_MAX_(image, image_size)\
  2852. ((8U/*sig*/+25U/*IHDR*/+16U/*gAMA*/+44U/*cHRM*/+12U/*IEND*/+\
  2853. (((image).format&PNG_FORMAT_FLAG_COLORMAP)?/*colormap: PLTE, tRNS*/\
  2854. 12U+3U*(image).colormap_entries/*PLTE data*/+\
  2855. (((image).format&PNG_FORMAT_FLAG_ALPHA)?\
  2856. 12U/*tRNS*/+(image).colormap_entries:0U):0U)+\
  2857. 12U)+(12U*((image_size)/PNG_ZBUF_SIZE))/*IDAT*/+(image_size))
  2858. /* A helper for the following macro; if your compiler cannot handle the
  2859. * following macro use this one with the result of
  2860. * PNG_IMAGE_COMPRESSED_SIZE_MAX(image) as the second argument (most
  2861. * compilers should handle this just fine.)
  2862. */
  2863. #define PNG_IMAGE_PNG_SIZE_MAX(image)\
  2864. PNG_IMAGE_PNG_SIZE_MAX_(image, PNG_IMAGE_COMPRESSED_SIZE_MAX(image))
  2865. /* An upper bound on the total length of the PNG data stream for 'image'.
  2866. * The result is of type png_alloc_size_t, on 32-bit systems this may
  2867. * overflow even though PNG_IMAGE_DATA_SIZE does not overflow; the write will
  2868. * run out of buffer space but return a corrected size which should work.
  2869. */
  2870. #endif /* SIMPLIFIED_WRITE */
  2871. /*******************************************************************************
  2872. * END OF SIMPLIFIED API
  2873. ******************************************************************************/
  2874. #endif /* SIMPLIFIED_{READ|WRITE} */
  2875. /*******************************************************************************
  2876. * Section 6: IMPLEMENTATION OPTIONS
  2877. *******************************************************************************
  2878. *
  2879. * Support for arbitrary implementation-specific optimizations. The API allows
  2880. * particular options to be turned on or off. 'Option' is the number of the
  2881. * option and 'onoff' is 0 (off) or non-0 (on). The value returned is given
  2882. * by the PNG_OPTION_ defines below.
  2883. *
  2884. * HARDWARE: normally hardware capabilites, such as the Intel SSE instructions,
  2885. * are detected at run time, however sometimes it may be impossible
  2886. * to do this in user mode, in which case it is necessary to discover
  2887. * the capabilities in an OS specific way. Such capabilities are
  2888. * listed here when libpng has support for them and must be turned
  2889. * ON by the application if present.
  2890. *
  2891. * SOFTWARE: sometimes software optimizations actually result in performance
  2892. * decrease on some architectures or systems, or with some sets of
  2893. * PNG images. 'Software' options allow such optimizations to be
  2894. * selected at run time.
  2895. */
  2896. #ifdef PNG_SET_OPTION_SUPPORTED
  2897. #ifdef PNG_ARM_NEON_API_SUPPORTED
  2898. # define PNG_ARM_NEON 0 /* HARDWARE: ARM Neon SIMD instructions supported */
  2899. #endif
  2900. #define PNG_MAXIMUM_INFLATE_WINDOW 2 /* SOFTWARE: force maximum window */
  2901. #define PNG_SKIP_sRGB_CHECK_PROFILE 4 /* SOFTWARE: Check ICC profile for sRGB */
  2902. #ifdef PNG_MIPS_MSA_API_SUPPORTED
  2903. # define PNG_MIPS_MSA 6 /* HARDWARE: MIPS Msa SIMD instructions supported */
  2904. #endif
  2905. #define PNG_IGNORE_ADLER32 8
  2906. #ifdef PNG_POWERPC_VSX_API_SUPPORTED
  2907. # define PNG_POWERPC_VSX 10 /* HARDWARE: PowerPC VSX SIMD instructions supported */
  2908. #endif
  2909. #define PNG_OPTION_NEXT 12 /* Next option - numbers must be even */
  2910. /* Return values: NOTE: there are four values and 'off' is *not* zero */
  2911. #define PNG_OPTION_UNSET 0 /* Unset - defaults to off */
  2912. #define PNG_OPTION_INVALID 1 /* Option number out of range */
  2913. #define PNG_OPTION_OFF 2
  2914. #define PNG_OPTION_ON 3
  2915. PNG_EXPORT(244, int, png_set_option, (png_structrp png_ptr, int option,
  2916. int onoff));
  2917. #endif /* SET_OPTION */
  2918. /*******************************************************************************
  2919. * END OF HARDWARE AND SOFTWARE OPTIONS
  2920. ******************************************************************************/
  2921. /* Maintainer: Put new public prototypes here ^, in libpng.3, in project
  2922. * defs, and in scripts/symbols.def.
  2923. */
  2924. /* The last ordinal number (this is the *last* one already used; the next
  2925. * one to use is one more than this.)
  2926. */
  2927. #ifdef PNG_EXPORT_LAST_ORDINAL
  2928. PNG_EXPORT_LAST_ORDINAL(249);
  2929. #endif
  2930. #ifdef __cplusplus
  2931. }
  2932. #endif
  2933. #endif /* PNG_VERSION_INFO_ONLY */
  2934. /* Do not put anything past this line */
  2935. #endif /* PNG_H */