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  1.  
  2. /* pngpriv.h - private declarations for use inside libpng
  3.  *
  4.  * For conditions of distribution and use, see copyright notice in png.h
  5.  * Copyright (c) 1998-2013 Glenn Randers-Pehrson
  6.  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  7.  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
  8.  *
  9.  * Last changed in libpng 1.6.3 [July 18, 2013]
  10.  *
  11.  * This code is released under the libpng license.
  12.  * For conditions of distribution and use, see the disclaimer
  13.  * and license in png.h
  14.  */
  15.  
  16. /* The symbols declared in this file (including the functions declared
  17.  * as extern) are PRIVATE.  They are not part of the libpng public
  18.  * interface, and are not recommended for use by regular applications.
  19.  * Some of them may become public in the future; others may stay private,
  20.  * change in an incompatible way, or even disappear.
  21.  * Although the libpng users are not forbidden to include this header,
  22.  * they should be well aware of the issues that may arise from doing so.
  23.  */
  24.  
  25. #ifndef PNGPRIV_H
  26. #define PNGPRIV_H
  27.  
  28. /* Feature Test Macros.  The following are defined here to ensure that correctly
  29.  * implemented libraries reveal the APIs libpng needs to build and hide those
  30.  * that are not needed and potentially damaging to the compilation.
  31.  *
  32.  * Feature Test Macros must be defined before any system header is included (see
  33.  * POSIX 1003.1 2.8.2 "POSIX Symbols."
  34.  *
  35.  * These macros only have an effect if the operating system supports either
  36.  * POSIX 1003.1 or C99, or both.  On other operating systems (particularly
  37.  * Windows/Visual Studio) there is no effect; the OS specific tests below are
  38.  * still required (as of 2011-05-02.)
  39.  */
  40. #define _POSIX_SOURCE 1 /* Just the POSIX 1003.1 and C89 APIs */
  41.  
  42. #ifndef PNG_VERSION_INFO_ONLY
  43. /* Standard library headers not required by png.h: */
  44. #  include <stdlib.h>
  45. #  include <string.h>
  46. #endif
  47.  
  48. #define PNGLIB_BUILD /*libpng is being built, not used*/
  49.  
  50. /* If HAVE_CONFIG_H is defined during the build then the build system must
  51.  * provide an appropriate "config.h" file on the include path.  The header file
  52.  * must provide definitions as required below (search for "HAVE_CONFIG_H");
  53.  * see configure.ac for more details of the requirements.  The macro
  54.  * "PNG_NO_CONFIG_H" is provided for maintainers to test for dependencies on
  55.  * 'configure'; define this macro to prevent the configure build including the
  56.  * configure generated config.h.  Libpng is expected to compile without *any*
  57.  * special build system support on a reasonably ANSI-C compliant system.
  58.  */
  59. #if defined(HAVE_CONFIG_H) && !defined(PNG_NO_CONFIG_H)
  60. #  include <config.h>
  61.  
  62.    /* Pick up the definition of 'restrict' from config.h if it was read: */
  63. #  define PNG_RESTRICT restrict
  64. #endif
  65.  
  66. /* To support symbol prefixing it is necessary to know *before* including png.h
  67.  * whether the fixed point (and maybe other) APIs are exported, because if they
  68.  * are not internal definitions may be required.  This is handled below just
  69.  * before png.h is included, but load the configuration now if it is available.
  70.  */
  71. #ifndef PNGLCONF_H
  72. #  include "pnglibconf.h"
  73. #endif
  74.  
  75. /* Local renames may change non-exported API functions from png.h */
  76. #if defined(PNG_PREFIX) && !defined(PNGPREFIX_H)
  77. #  include "pngprefix.h"
  78. #endif
  79.  
  80. #ifdef PNG_USER_CONFIG
  81. #  include "pngusr.h"
  82.    /* These should have been defined in pngusr.h */
  83. #  ifndef PNG_USER_PRIVATEBUILD
  84. #    define PNG_USER_PRIVATEBUILD "Custom libpng build"
  85. #  endif
  86. #  ifndef PNG_USER_DLLFNAME_POSTFIX
  87. #    define PNG_USER_DLLFNAME_POSTFIX "Cb"
  88. #  endif
  89. #endif
  90.  
  91. /* Compile time options.
  92.  * =====================
  93.  * In a multi-arch build the compiler may compile the code several times for the
  94.  * same object module, producing different binaries for different architectures.
  95.  * When this happens configure-time setting of the target host options cannot be
  96.  * done and this interferes with the handling of the ARM NEON optimizations, and
  97.  * possibly other similar optimizations.  Put additional tests here; in general
  98.  * this is needed when the same option can be changed at both compile time and
  99.  * run time depending on the target OS (i.e. iOS vs Android.)
  100.  *
  101.  * NOTE: symbol prefixing does not pass $(CFLAGS) to the preprocessor, because
  102.  * this is not possible with certain compilers (Oracle SUN OS CC), as a result
  103.  * it is necessary to ensure that all extern functions that *might* be used
  104.  * regardless of $(CFLAGS) get declared in this file.  The test on __ARM_NEON__
  105.  * below is one example of this behavior because it is controlled by the
  106.  * presence or not of -mfpu=neon on the GCC command line, it is possible to do
  107.  * this in $(CC), e.g. "CC=gcc -mfpu=neon", but people who build libpng rarely
  108.  * do this.
  109.  */
  110. #ifndef PNG_ARM_NEON_OPT
  111.    /* ARM NEON optimizations are being controlled by the compiler settings,
  112.     * typically the target FPU.  If the FPU has been set to NEON (-mfpu=neon
  113.     * with GCC) then the compiler will define __ARM_NEON__ and we can rely
  114.     * unconditionally on NEON instructions not crashing, otherwise we must
  115.     * disable use of NEON instructions:
  116.     */
  117. #  ifdef __ARM_NEON__
  118. #     define PNG_ARM_NEON_OPT 2
  119. #  else
  120. #     define PNG_ARM_NEON_OPT 0
  121. #  endif
  122. #endif
  123.  
  124. #if PNG_ARM_NEON_OPT > 0
  125.    /* NEON optimizations are to be at least considered by libpng, so enable the
  126.     * callbacks to do this.
  127.     */
  128. #  define PNG_FILTER_OPTIMIZATIONS png_init_filter_functions_neon
  129. #endif
  130.  
  131. /* Is this a build of a DLL where compilation of the object modules requires
  132.  * different preprocessor settings to those required for a simple library?  If
  133.  * so PNG_BUILD_DLL must be set.
  134.  *
  135.  * If libpng is used inside a DLL but that DLL does not export the libpng APIs
  136.  * PNG_BUILD_DLL must not be set.  To avoid the code below kicking in build a
  137.  * static library of libpng then link the DLL against that.
  138.  */
  139. #ifndef PNG_BUILD_DLL
  140. #  ifdef DLL_EXPORT
  141.       /* This is set by libtool when files are compiled for a DLL; libtool
  142.        * always compiles twice, even on systems where it isn't necessary.  Set
  143.        * PNG_BUILD_DLL in case it is necessary:
  144.        */
  145. #     define PNG_BUILD_DLL
  146. #  else
  147. #     ifdef _WINDLL
  148.          /* This is set by the Microsoft Visual Studio IDE in projects that
  149.           * build a DLL.  It can't easily be removed from those projects (it
  150.           * isn't visible in the Visual Studio UI) so it is a fairly reliable
  151.           * indication that PNG_IMPEXP needs to be set to the DLL export
  152.           * attributes.
  153.           */
  154. #        define PNG_BUILD_DLL
  155. #     else
  156. #        ifdef __DLL__
  157.             /* This is set by the Borland C system when compiling for a DLL
  158.              * (as above.)
  159.              */
  160. #           define PNG_BUILD_DLL
  161. #        else
  162.             /* Add additional compiler cases here. */
  163. #        endif
  164. #     endif
  165. #  endif
  166. #endif /* Setting PNG_BUILD_DLL if required */
  167.  
  168. /* See pngconf.h for more details: the builder of the library may set this on
  169.  * the command line to the right thing for the specific compilation system or it
  170.  * may be automagically set above (at present we know of no system where it does
  171.  * need to be set on the command line.)
  172.  *
  173.  * PNG_IMPEXP must be set here when building the library to prevent pngconf.h
  174.  * setting it to the "import" setting for a DLL build.
  175.  */
  176. #ifndef PNG_IMPEXP
  177. #  ifdef PNG_BUILD_DLL
  178. #     define PNG_IMPEXP PNG_DLL_EXPORT
  179. #  else
  180.       /* Not building a DLL, or the DLL doesn't require specific export
  181.        * definitions.
  182.        */
  183. #     define PNG_IMPEXP
  184. #  endif
  185. #endif
  186.  
  187. /* No warnings for private or deprecated functions in the build: */
  188. #ifndef PNG_DEPRECATED
  189. #  define PNG_DEPRECATED
  190. #endif
  191. #ifndef PNG_PRIVATE
  192. #  define PNG_PRIVATE
  193. #endif
  194.  
  195. /* Symbol preprocessing support.
  196.  *
  197.  * To enable listing global, but internal, symbols the following macros should
  198.  * always be used to declare an extern data or function object in this file.
  199.  */
  200. #ifndef PNG_INTERNAL_DATA
  201. #  define PNG_INTERNAL_DATA(type, name, array) extern type name array
  202. #endif
  203.  
  204. #ifndef PNG_INTERNAL_FUNCTION
  205. #  define PNG_INTERNAL_FUNCTION(type, name, args, attributes)\
  206.       extern PNG_FUNCTION(type, name, args, PNG_EMPTY attributes)
  207. #endif
  208.  
  209. /* If floating or fixed point APIs are disabled they may still be compiled
  210.  * internally.  To handle this make sure they are declared as the appropriate
  211.  * internal extern function (otherwise the symbol prefixing stuff won't work and
  212.  * the functions will be used without definitions.)
  213.  *
  214.  * NOTE: although all the API functions are declared here they are not all
  215.  * actually built!  Because the declarations are still made it is necessary to
  216.  * fake out types that they depend on.
  217.  */
  218. #ifndef PNG_FP_EXPORT
  219. #  ifndef PNG_FLOATING_POINT_SUPPORTED
  220. #     define PNG_FP_EXPORT(ordinal, type, name, args)\
  221.          PNG_INTERNAL_FUNCTION(type, name, args, PNG_EMPTY);
  222. #     ifndef PNG_VERSION_INFO_ONLY
  223.          typedef struct png_incomplete png_double;
  224.          typedef png_double*           png_doublep;
  225.          typedef const png_double*     png_const_doublep;
  226.          typedef png_double**          png_doublepp;
  227. #     endif
  228. #  endif
  229. #endif
  230. #ifndef PNG_FIXED_EXPORT
  231. #  ifndef PNG_FIXED_POINT_SUPPORTED
  232. #     define PNG_FIXED_EXPORT(ordinal, type, name, args)\
  233.          PNG_INTERNAL_FUNCTION(type, name, args, PNG_EMPTY);
  234. #  endif
  235. #endif
  236.  
  237. #include "png.h"
  238.  
  239. /* pngconf.h does not set PNG_DLL_EXPORT unless it is required, so: */
  240. #ifndef PNG_DLL_EXPORT
  241. #  define PNG_DLL_EXPORT
  242. #endif
  243.  
  244. /* SECURITY and SAFETY:
  245.  *
  246.  * By default libpng is built without any internal limits on image size,
  247.  * individual heap (png_malloc) allocations or the total amount of memory used.
  248.  * If PNG_SAFE_LIMITS_SUPPORTED is defined, however, the limits below are used
  249.  * (unless individually overridden).  These limits are believed to be fairly
  250.  * safe, but builders of secure systems should verify the values against the
  251.  * real system capabilities.
  252.  */
  253. #ifdef PNG_SAFE_LIMITS_SUPPORTED
  254.    /* 'safe' limits */
  255. #  ifndef PNG_USER_WIDTH_MAX
  256. #     define PNG_USER_WIDTH_MAX 1000000
  257. #  endif
  258. #  ifndef PNG_USER_HEIGHT_MAX
  259. #     define PNG_USER_HEIGHT_MAX 1000000
  260. #  endif
  261. #  ifndef PNG_USER_CHUNK_CACHE_MAX
  262. #     define PNG_USER_CHUNK_CACHE_MAX 128
  263. #  endif
  264. #  ifndef PNG_USER_CHUNK_MALLOC_MAX
  265. #     define PNG_USER_CHUNK_MALLOC_MAX 8000000
  266. #  endif
  267. #else
  268.    /* values for no limits */
  269. #  ifndef PNG_USER_WIDTH_MAX
  270. #     define PNG_USER_WIDTH_MAX 0x7fffffff
  271. #  endif
  272. #  ifndef PNG_USER_HEIGHT_MAX
  273. #     define PNG_USER_HEIGHT_MAX 0x7fffffff
  274. #  endif
  275. #  ifndef PNG_USER_CHUNK_CACHE_MAX
  276. #     define PNG_USER_CHUNK_CACHE_MAX 0
  277. #  endif
  278. #  ifndef PNG_USER_CHUNK_MALLOC_MAX
  279. #     define PNG_USER_CHUNK_MALLOC_MAX 0
  280. #  endif
  281. #endif
  282.  
  283. /* Moved to pngpriv.h at libpng-1.5.0 */
  284. /* NOTE: some of these may have been used in external applications as
  285.  * these definitions were exposed in pngconf.h prior to 1.5.
  286.  */
  287.  
  288. /* If you are running on a machine where you cannot allocate more
  289.  * than 64K of memory at once, uncomment this.  While libpng will not
  290.  * normally need that much memory in a chunk (unless you load up a very
  291.  * large file), zlib needs to know how big of a chunk it can use, and
  292.  * libpng thus makes sure to check any memory allocation to verify it
  293.  * will fit into memory.
  294.  *
  295.  * zlib provides 'MAXSEG_64K' which, if defined, indicates the
  296.  * same limit and pngconf.h (already included) sets the limit
  297.  * if certain operating systems are detected.
  298.  */
  299. #if defined(MAXSEG_64K) && !defined(PNG_MAX_MALLOC_64K)
  300. #  define PNG_MAX_MALLOC_64K
  301. #endif
  302.  
  303. #ifndef PNG_UNUSED
  304. /* Unused formal parameter warnings are silenced using the following macro
  305.  * which is expected to have no bad effects on performance (optimizing
  306.  * compilers will probably remove it entirely).  Note that if you replace
  307.  * it with something other than whitespace, you must include the terminating
  308.  * semicolon.
  309.  */
  310. #  define PNG_UNUSED(param) (void)param;
  311. #endif
  312.  
  313. /* Just a little check that someone hasn't tried to define something
  314.  * contradictory.
  315.  */
  316. #if (PNG_ZBUF_SIZE > 65536L) && defined(PNG_MAX_MALLOC_64K)
  317. #  undef PNG_ZBUF_SIZE
  318. #  define PNG_ZBUF_SIZE 65536L
  319. #endif
  320.  
  321. /* If warnings or errors are turned off the code is disabled or redirected here.
  322.  * From 1.5.4 functions have been added to allow very limited formatting of
  323.  * error and warning messages - this code will also be disabled here.
  324.  */
  325. #ifdef PNG_WARNINGS_SUPPORTED
  326. #  define PNG_WARNING_PARAMETERS(p) png_warning_parameters p;
  327. #else
  328. #  define png_warning(s1,s2) ((void)(s1))
  329. #  define png_chunk_warning(s1,s2) ((void)(s1))
  330. #  define png_warning_parameter(p,number,string) ((void)0)
  331. #  define png_warning_parameter_unsigned(p,number,format,value) ((void)0)
  332. #  define png_warning_parameter_signed(p,number,format,value) ((void)0)
  333. #  define png_formatted_warning(pp,p,message) ((void)(pp))
  334. #  define PNG_WARNING_PARAMETERS(p)
  335. #endif
  336. #ifndef PNG_ERROR_TEXT_SUPPORTED
  337. #  define png_error(s1,s2) png_err(s1)
  338. #  define png_chunk_error(s1,s2) png_err(s1)
  339. #  define png_fixed_error(s1,s2) png_err(s1)
  340. #endif
  341.  
  342. /* C allows up-casts from (void*) to any pointer and (const void*) to any
  343.  * pointer to a const object.  C++ regards this as a type error and requires an
  344.  * explicit, static, cast and provides the static_cast<> rune to ensure that
  345.  * const is not cast away.
  346.  */
  347. #ifdef __cplusplus
  348. #  define png_voidcast(type, value) static_cast<type>(value)
  349. #  define png_constcast(type, value) const_cast<type>(value)
  350. #  define png_aligncast(type, value) \
  351.    static_cast<type>(static_cast<void*>(value))
  352. #  define png_aligncastconst(type, value) \
  353.    static_cast<type>(static_cast<const void*>(value))
  354. #else
  355. #  define png_voidcast(type, value) (value)
  356. #  define png_constcast(type, value) ((type)(value))
  357. #  define png_aligncast(type, value) ((void*)(value))
  358. #  define png_aligncastconst(type, value) ((const void*)(value))
  359. #endif /* __cplusplus */
  360.  
  361. /* Some fixed point APIs are still required even if not exported because
  362.  * they get used by the corresponding floating point APIs.  This magic
  363.  * deals with this:
  364.  */
  365. #ifdef PNG_FIXED_POINT_SUPPORTED
  366. #  define PNGFAPI PNGAPI
  367. #else
  368. #  define PNGFAPI /* PRIVATE */
  369. #endif
  370.  
  371. #ifndef PNG_VERSION_INFO_ONLY
  372. /* Other defines specific to compilers can go here.  Try to keep
  373.  * them inside an appropriate ifdef/endif pair for portability.
  374.  */
  375. #if defined(PNG_FLOATING_POINT_SUPPORTED) ||\
  376.     defined(PNG_FLOATING_ARITHMETIC_SUPPORTED)
  377.    /* png.c requires the following ANSI-C constants if the conversion of
  378.     * floating point to ASCII is implemented therein:
  379.     *
  380.     *  DBL_DIG  Maximum number of decimal digits (can be set to any constant)
  381.     *  DBL_MIN  Smallest normalized fp number (can be set to an arbitrary value)
  382.     *  DBL_MAX  Maximum floating point number (can be set to an arbitrary value)
  383.     */
  384. #  include <float.h>
  385.  
  386. #  if (defined(__MWERKS__) && defined(macintosh)) || defined(applec) || \
  387.     defined(THINK_C) || defined(__SC__) || defined(TARGET_OS_MAC)
  388.      /* We need to check that <math.h> hasn't already been included earlier
  389.       * as it seems it doesn't agree with <fp.h>, yet we should really use
  390.       * <fp.h> if possible.
  391.       */
  392. #    if !defined(__MATH_H__) && !defined(__MATH_H) && !defined(__cmath__)
  393. #      include <fp.h>
  394. #    endif
  395. #  else
  396. #    include <math.h>
  397. #  endif
  398. #  if defined(_AMIGA) && defined(__SASC) && defined(_M68881)
  399.      /* Amiga SAS/C: We must include builtin FPU functions when compiling using
  400.       * MATH=68881
  401.       */
  402. #    include <m68881.h>
  403. #  endif
  404. #endif
  405.  
  406. /* This provides the non-ANSI (far) memory allocation routines. */
  407. #if defined(__TURBOC__) && defined(__MSDOS__)
  408. #  include <mem.h>
  409. #  include <alloc.h>
  410. #endif
  411.  
  412. #if defined(WIN32) || defined(_Windows) || defined(_WINDOWS) || \
  413.     defined(_WIN32) || defined(__WIN32__)
  414. #  include <windows.h>  /* defines _WINDOWS_ macro */
  415. #endif
  416. #endif /* PNG_VERSION_INFO_ONLY */
  417.  
  418. /* Moved here around 1.5.0beta36 from pngconf.h */
  419. /* Users may want to use these so they are not private.  Any library
  420.  * functions that are passed far data must be model-independent.
  421.  */
  422.  
  423. /* Memory model/platform independent fns */
  424. #ifndef PNG_ABORT
  425. #  ifdef _WINDOWS_
  426. #    define PNG_ABORT() ExitProcess(0)
  427. #  else
  428. #    define PNG_ABORT() abort()
  429. #  endif
  430. #endif
  431.  
  432. /* These macros may need to be architecture dependent. */
  433. #define PNG_ALIGN_NONE   0 /* do not use data alignment */
  434. #define PNG_ALIGN_ALWAYS 1 /* assume unaligned accesses are OK */
  435. #ifdef offsetof
  436. #  define PNG_ALIGN_OFFSET 2 /* use offsetof to determine alignment */
  437. #else
  438. #  define PNG_ALIGN_OFFSET -1 /* prevent the use of this */
  439. #endif
  440. #define PNG_ALIGN_SIZE   3 /* use sizeof to determine alignment */
  441.  
  442. #ifndef PNG_ALIGN_TYPE
  443.    /* Default to using aligned access optimizations and requiring alignment to a
  444.     * multiple of the data type size.  Override in a compiler specific fashion
  445.     * if necessary by inserting tests here:
  446.     */
  447. #  define PNG_ALIGN_TYPE PNG_ALIGN_SIZE
  448. #endif
  449.  
  450. #if PNG_ALIGN_TYPE == PNG_ALIGN_SIZE
  451.    /* This is used because in some compiler implementations non-aligned
  452.     * structure members are supported, so the offsetof approach below fails.
  453.     * Set PNG_ALIGN_SIZE=0 for compiler combinations where unaligned access
  454.     * is good for performance.  Do not do this unless you have tested the result
  455.     * and understand it.
  456.     */
  457. #  define png_alignof(type) (sizeof (type))
  458. #else
  459. #  if PNG_ALIGN_TYPE == PNG_ALIGN_OFFSET
  460. #     define png_alignof(type) offsetof(struct{char c; type t;}, t)
  461. #  else
  462. #     if PNG_ALIGN_TYPE == PNG_ALIGN_ALWAYS
  463. #        define png_alignof(type) (1)
  464. #     endif
  465.       /* Else leave png_alignof undefined to prevent use thereof */
  466. #  endif
  467. #endif
  468.  
  469. /* This implicitly assumes alignment is always to a power of 2. */
  470. #ifdef png_alignof
  471. #  define png_isaligned(ptr, type)\
  472.    ((((const char*)ptr-(const char*)0) & (png_alignof(type)-1)) == 0)
  473. #else
  474. #  define png_isaligned(ptr, type) 0
  475. #endif
  476.  
  477. /* End of memory model/platform independent support */
  478. /* End of 1.5.0beta36 move from pngconf.h */
  479.  
  480. /* CONSTANTS and UTILITY MACROS
  481.  * These are used internally by libpng and not exposed in the API
  482.  */
  483.  
  484. /* Various modes of operation.  Note that after an init, mode is set to
  485.  * zero automatically when the structure is created.  Three of these
  486.  * are defined in png.h because they need to be visible to applications
  487.  * that call png_set_unknown_chunk().
  488.  */
  489. /* #define PNG_HAVE_IHDR            0x01 (defined in png.h) */
  490. /* #define PNG_HAVE_PLTE            0x02 (defined in png.h) */
  491. #define PNG_HAVE_IDAT               0x04
  492. /* #define PNG_AFTER_IDAT           0x08 (defined in png.h) */
  493. #define PNG_HAVE_IEND               0x10
  494.                    /*               0x20 (unused) */
  495.                    /*               0x40 (unused) */
  496.                    /*               0x80 (unused) */
  497. #define PNG_HAVE_CHUNK_HEADER      0x100
  498. #define PNG_WROTE_tIME             0x200
  499. #define PNG_WROTE_INFO_BEFORE_PLTE 0x400
  500. #define PNG_BACKGROUND_IS_GRAY     0x800
  501. #define PNG_HAVE_PNG_SIGNATURE    0x1000
  502. #define PNG_HAVE_CHUNK_AFTER_IDAT 0x2000 /* Have another chunk after IDAT */
  503.                    /*             0x4000 (unused) */
  504. #define PNG_IS_READ_STRUCT        0x8000 /* Else is a write struct */
  505.  
  506. /* Flags for the transformations the PNG library does on the image data */
  507. #define PNG_BGR                 0x0001
  508. #define PNG_INTERLACE           0x0002
  509. #define PNG_PACK                0x0004
  510. #define PNG_SHIFT               0x0008
  511. #define PNG_SWAP_BYTES          0x0010
  512. #define PNG_INVERT_MONO         0x0020
  513. #define PNG_QUANTIZE            0x0040
  514. #define PNG_COMPOSE             0x0080     /* Was PNG_BACKGROUND */
  515. #define PNG_BACKGROUND_EXPAND   0x0100
  516. #define PNG_EXPAND_16           0x0200     /* Added to libpng 1.5.2 */
  517. #define PNG_16_TO_8             0x0400     /* Becomes 'chop' in 1.5.4 */
  518. #define PNG_RGBA                0x0800
  519. #define PNG_EXPAND              0x1000
  520. #define PNG_GAMMA               0x2000
  521. #define PNG_GRAY_TO_RGB         0x4000
  522. #define PNG_FILLER              0x8000
  523. #define PNG_PACKSWAP           0x10000
  524. #define PNG_SWAP_ALPHA         0x20000
  525. #define PNG_STRIP_ALPHA        0x40000
  526. #define PNG_INVERT_ALPHA       0x80000
  527. #define PNG_USER_TRANSFORM    0x100000
  528. #define PNG_RGB_TO_GRAY_ERR   0x200000
  529. #define PNG_RGB_TO_GRAY_WARN  0x400000
  530. #define PNG_RGB_TO_GRAY       0x600000 /* two bits, RGB_TO_GRAY_ERR|WARN */
  531. #define PNG_ENCODE_ALPHA      0x800000 /* Added to libpng-1.5.4 */
  532. #define PNG_ADD_ALPHA         0x1000000 /* Added to libpng-1.2.7 */
  533. #define PNG_EXPAND_tRNS       0x2000000 /* Added to libpng-1.2.9 */
  534. #define PNG_SCALE_16_TO_8     0x4000000 /* Added to libpng-1.5.4 */
  535.                        /*   0x8000000 unused */
  536.                        /*  0x10000000 unused */
  537.                        /*  0x20000000 unused */
  538.                        /*  0x40000000 unused */
  539. /* Flags for png_create_struct */
  540. #define PNG_STRUCT_PNG   0x0001
  541. #define PNG_STRUCT_INFO  0x0002
  542.  
  543. /* Scaling factor for filter heuristic weighting calculations */
  544. #define PNG_WEIGHT_FACTOR (1<<(PNG_WEIGHT_SHIFT))
  545. #define PNG_COST_FACTOR (1<<(PNG_COST_SHIFT))
  546.  
  547. /* Flags for the png_ptr->flags rather than declaring a byte for each one */
  548. #define PNG_FLAG_ZLIB_CUSTOM_STRATEGY     0x0001
  549. #define PNG_FLAG_ZSTREAM_INITIALIZED      0x0002 /* Added to libpng-1.6.0 */
  550.                                   /*      0x0004    unused */
  551. #define PNG_FLAG_ZSTREAM_ENDED            0x0008 /* Added to libpng-1.6.0 */
  552.                                   /*      0x0010    unused */
  553.                                   /*      0x0020    unused */
  554. #define PNG_FLAG_ROW_INIT                 0x0040
  555. #define PNG_FLAG_FILLER_AFTER             0x0080
  556. #define PNG_FLAG_CRC_ANCILLARY_USE        0x0100
  557. #define PNG_FLAG_CRC_ANCILLARY_NOWARN     0x0200
  558. #define PNG_FLAG_CRC_CRITICAL_USE         0x0400
  559. #define PNG_FLAG_CRC_CRITICAL_IGNORE      0x0800
  560. #define PNG_FLAG_ASSUME_sRGB              0x1000 /* Added to libpng-1.5.4 */
  561. #define PNG_FLAG_OPTIMIZE_ALPHA           0x2000 /* Added to libpng-1.5.4 */
  562. #define PNG_FLAG_DETECT_UNINITIALIZED     0x4000 /* Added to libpng-1.5.4 */
  563. /* #define PNG_FLAG_KEEP_UNKNOWN_CHUNKS      0x8000 */
  564. /* #define PNG_FLAG_KEEP_UNSAFE_CHUNKS      0x10000 */
  565. #define PNG_FLAG_LIBRARY_MISMATCH        0x20000
  566. #define PNG_FLAG_STRIP_ERROR_NUMBERS     0x40000
  567. #define PNG_FLAG_STRIP_ERROR_TEXT        0x80000
  568. #define PNG_FLAG_BENIGN_ERRORS_WARN     0x100000 /* Added to libpng-1.4.0 */
  569. #define PNG_FLAG_APP_WARNINGS_WARN      0x200000 /* Added to libpng-1.6.0 */
  570. #define PNG_FLAG_APP_ERRORS_WARN        0x400000 /* Added to libpng-1.6.0 */
  571.                                   /*    0x800000    unused */
  572.                                   /*   0x1000000    unused */
  573.                                   /*   0x2000000    unused */
  574.                                   /*   0x4000000    unused */
  575.                                   /*   0x8000000    unused */
  576.                                   /*  0x10000000    unused */
  577.                                   /*  0x20000000    unused */
  578.                                   /*  0x40000000    unused */
  579.  
  580. #define PNG_FLAG_CRC_ANCILLARY_MASK (PNG_FLAG_CRC_ANCILLARY_USE | \
  581.                                      PNG_FLAG_CRC_ANCILLARY_NOWARN)
  582.  
  583. #define PNG_FLAG_CRC_CRITICAL_MASK  (PNG_FLAG_CRC_CRITICAL_USE | \
  584.                                      PNG_FLAG_CRC_CRITICAL_IGNORE)
  585.  
  586. #define PNG_FLAG_CRC_MASK           (PNG_FLAG_CRC_ANCILLARY_MASK | \
  587.                                      PNG_FLAG_CRC_CRITICAL_MASK)
  588.  
  589. /* Save typing and make code easier to understand */
  590.  
  591. #define PNG_COLOR_DIST(c1, c2) (abs((int)((c1).red) - (int)((c2).red)) + \
  592.    abs((int)((c1).green) - (int)((c2).green)) + \
  593.    abs((int)((c1).blue) - (int)((c2).blue)))
  594.  
  595. /* Added to libpng-1.6.0: scale a 16-bit value in the range 0..65535 to 0..255
  596.  * by dividing by 257 *with rounding*.  This macro is exact for the given range.
  597.  * See the discourse in pngrtran.c png_do_scale_16_to_8.  The values in the
  598.  * macro were established by experiment (modifying the added value).  The macro
  599.  * has a second variant that takes a value already scaled by 255 and divides by
  600.  * 65535 - this has a maximum error of .502.  Over the range 0..65535*65535 it
  601.  * only gives off-by-one errors and only for 0.5% (1 in 200) of the values.
  602.  */
  603. #define PNG_DIV65535(v24) (((v24) + 32895) >> 16)
  604. #define PNG_DIV257(v16) PNG_DIV65535((png_uint_32)(v16) * 255)
  605.  
  606. /* Added to libpng-1.2.6 JB */
  607. #define PNG_ROWBYTES(pixel_bits, width) \
  608.     ((pixel_bits) >= 8 ? \
  609.     ((png_size_t)(width) * (((png_size_t)(pixel_bits)) >> 3)) : \
  610.     (( ((png_size_t)(width) * ((png_size_t)(pixel_bits))) + 7) >> 3) )
  611.  
  612. /* PNG_OUT_OF_RANGE returns true if value is outside the range
  613.  * ideal-delta..ideal+delta.  Each argument is evaluated twice.
  614.  * "ideal" and "delta" should be constants, normally simple
  615.  * integers, "value" a variable. Added to libpng-1.2.6 JB
  616.  */
  617. #define PNG_OUT_OF_RANGE(value, ideal, delta) \
  618.    ( (value) < (ideal)-(delta) || (value) > (ideal)+(delta) )
  619.  
  620. /* Conversions between fixed and floating point, only defined if
  621.  * required (to make sure the code doesn't accidentally use float
  622.  * when it is supposedly disabled.)
  623.  */
  624. #ifdef PNG_FLOATING_POINT_SUPPORTED
  625. /* The floating point conversion can't overflow, though it can and
  626.  * does lose accuracy relative to the original fixed point value.
  627.  * In practice this doesn't matter because png_fixed_point only
  628.  * stores numbers with very low precision.  The png_ptr and s
  629.  * arguments are unused by default but are there in case error
  630.  * checking becomes a requirement.
  631.  */
  632. #define png_float(png_ptr, fixed, s) (.00001 * (fixed))
  633.  
  634. /* The fixed point conversion performs range checking and evaluates
  635.  * its argument multiple times, so must be used with care.  The
  636.  * range checking uses the PNG specification values for a signed
  637.  * 32 bit fixed point value except that the values are deliberately
  638.  * rounded-to-zero to an integral value - 21474 (21474.83 is roughly
  639.  * (2^31-1) * 100000). 's' is a string that describes the value being
  640.  * converted.
  641.  *
  642.  * NOTE: this macro will raise a png_error if the range check fails,
  643.  * therefore it is normally only appropriate to use this on values
  644.  * that come from API calls or other sources where an out of range
  645.  * error indicates a programming error, not a data error!
  646.  *
  647.  * NOTE: by default this is off - the macro is not used - because the
  648.  * function call saves a lot of code.
  649.  */
  650. #ifdef PNG_FIXED_POINT_MACRO_SUPPORTED
  651. #define png_fixed(png_ptr, fp, s) ((fp) <= 21474 && (fp) >= -21474 ?\
  652.     ((png_fixed_point)(100000 * (fp))) : (png_fixed_error(png_ptr, s),0))
  653. #endif
  654. /* else the corresponding function is defined below, inside the scope of the
  655.  * cplusplus test.
  656.  */
  657. #endif
  658.  
  659. /* Constants for known chunk types.  If you need to add a chunk, define the name
  660.  * here.  For historical reasons these constants have the form png_<name>; i.e.
  661.  * the prefix is lower case.  Please use decimal values as the parameters to
  662.  * match the ISO PNG specification and to avoid relying on the C locale
  663.  * interpretation of character values.
  664.  *
  665.  * Prior to 1.5.6 these constants were strings, as of 1.5.6 png_uint_32 values
  666.  * are computed and a new macro (PNG_STRING_FROM_CHUNK) added to allow a string
  667.  * to be generated if required.
  668.  *
  669.  * PNG_32b correctly produces a value shifted by up to 24 bits, even on
  670.  * architectures where (int) is only 16 bits.
  671.  */
  672. #define PNG_32b(b,s) ((png_uint_32)(b) << (s))
  673. #define PNG_U32(b1,b2,b3,b4) \
  674.    (PNG_32b(b1,24) | PNG_32b(b2,16) | PNG_32b(b3,8) | PNG_32b(b4,0))
  675.  
  676. /* Constants for known chunk types.
  677.  *
  678.  * MAINTAINERS: If you need to add a chunk, define the name here.
  679.  * For historical reasons these constants have the form png_<name>; i.e.
  680.  * the prefix is lower case.  Please use decimal values as the parameters to
  681.  * match the ISO PNG specification and to avoid relying on the C locale
  682.  * interpretation of character values.  Please keep the list sorted.
  683.  *
  684.  * Notice that PNG_U32 is used to define a 32-bit value for the 4 byte chunk
  685.  * type.  In fact the specification does not express chunk types this way,
  686.  * however using a 32-bit value means that the chunk type can be read from the
  687.  * stream using exactly the same code as used for a 32-bit unsigned value and
  688.  * can be examined far more efficiently (using one arithmetic compare).
  689.  *
  690.  * Prior to 1.5.6 the chunk type constants were expressed as C strings.  The
  691.  * libpng API still uses strings for 'unknown' chunks and a macro,
  692.  * PNG_STRING_FROM_CHUNK, allows a string to be generated if required.  Notice
  693.  * that for portable code numeric values must still be used; the string "IHDR"
  694.  * is not portable and neither is PNG_U32('I', 'H', 'D', 'R').
  695.  *
  696.  * In 1.7.0 the definitions will be made public in png.h to avoid having to
  697.  * duplicate the same definitions in application code.
  698.  */
  699. #define png_IDAT PNG_U32( 73,  68,  65,  84)
  700. #define png_IEND PNG_U32( 73,  69,  78,  68)
  701. #define png_IHDR PNG_U32( 73,  72,  68,  82)
  702. #define png_PLTE PNG_U32( 80,  76,  84,  69)
  703. #define png_bKGD PNG_U32( 98,  75,  71,  68)
  704. #define png_cHRM PNG_U32( 99,  72,  82,  77)
  705. #define png_fRAc PNG_U32(102,  82,  65,  99) /* registered, not defined */
  706. #define png_gAMA PNG_U32(103,  65,  77,  65)
  707. #define png_gIFg PNG_U32(103,  73,  70, 103)
  708. #define png_gIFt PNG_U32(103,  73,  70, 116) /* deprecated */
  709. #define png_gIFx PNG_U32(103,  73,  70, 120)
  710. #define png_hIST PNG_U32(104,  73,  83,  84)
  711. #define png_iCCP PNG_U32(105,  67,  67,  80)
  712. #define png_iTXt PNG_U32(105,  84,  88, 116)
  713. #define png_oFFs PNG_U32(111,  70,  70, 115)
  714. #define png_pCAL PNG_U32(112,  67,  65,  76)
  715. #define png_pHYs PNG_U32(112,  72,  89, 115)
  716. #define png_sBIT PNG_U32(115,  66,  73,  84)
  717. #define png_sCAL PNG_U32(115,  67,  65,  76)
  718. #define png_sPLT PNG_U32(115,  80,  76,  84)
  719. #define png_sRGB PNG_U32(115,  82,  71,  66)
  720. #define png_sTER PNG_U32(115,  84,  69,  82)
  721. #define png_tEXt PNG_U32(116,  69,  88, 116)
  722. #define png_tIME PNG_U32(116,  73,  77,  69)
  723. #define png_tRNS PNG_U32(116,  82,  78,  83)
  724. #define png_zTXt PNG_U32(122,  84,  88, 116)
  725.  
  726. /* The following will work on (signed char*) strings, whereas the get_uint_32
  727.  * macro will fail on top-bit-set values because of the sign extension.
  728.  */
  729. #define PNG_CHUNK_FROM_STRING(s)\
  730.    PNG_U32(0xff&(s)[0], 0xff&(s)[1], 0xff&(s)[2], 0xff&(s)[3])
  731.  
  732. /* This uses (char), not (png_byte) to avoid warnings on systems where (char) is
  733.  * signed and the argument is a (char[])  This macro will fail miserably on
  734.  * systems where (char) is more than 8 bits.
  735.  */
  736. #define PNG_STRING_FROM_CHUNK(s,c)\
  737.    (void)(((char*)(s))[0]=(char)((c)>>24), ((char*)(s))[1]=(char)((c)>>16),\
  738.    ((char*)(s))[2]=(char)((c)>>8), ((char*)(s))[3]=(char)((c)))
  739.  
  740. /* Do the same but terminate with a null character. */
  741. #define PNG_CSTRING_FROM_CHUNK(s,c)\
  742.    (void)(PNG_STRING_FROM_CHUNK(s,c), ((char*)(s))[4] = 0)
  743.  
  744. /* Test on flag values as defined in the spec (section 5.4): */
  745. #define PNG_CHUNK_ANCILLARY(c)   (1 & ((c) >> 29))
  746. #define PNG_CHUNK_CRITICAL(c)     (!PNG_CHUNK_ANCILLARY(c))
  747. #define PNG_CHUNK_PRIVATE(c)      (1 & ((c) >> 21))
  748. #define PNG_CHUNK_RESERVED(c)     (1 & ((c) >> 13))
  749. #define PNG_CHUNK_SAFE_TO_COPY(c) (1 & ((c) >>  5))
  750.  
  751. /* Gamma values (new at libpng-1.5.4): */
  752. #define PNG_GAMMA_MAC_OLD 151724  /* Assume '1.8' is really 2.2/1.45! */
  753. #define PNG_GAMMA_MAC_INVERSE 65909
  754. #define PNG_GAMMA_sRGB_INVERSE 45455
  755.  
  756. /* Almost everything below is C specific; the #defines above can be used in
  757.  * non-C code (so long as it is C-preprocessed) the rest of this stuff cannot.
  758.  */
  759. #ifndef PNG_VERSION_INFO_ONLY
  760.  
  761. #include "pngstruct.h"
  762. #include "pnginfo.h"
  763.  
  764. /* Validate the include paths - the include path used to generate pnglibconf.h
  765.  * must match that used in the build, or we must be using pnglibconf.h.prebuilt:
  766.  */
  767. #if PNG_ZLIB_VERNUM != 0 && PNG_ZLIB_VERNUM != ZLIB_VERNUM
  768. #  error ZLIB_VERNUM != PNG_ZLIB_VERNUM \
  769.       "-I (include path) error: see the notes in pngpriv.h"
  770.    /* This means that when pnglibconf.h was built the copy of zlib.h that it
  771.     * used is not the same as the one being used here.  Because the build of
  772.     * libpng makes decisions to use inflateInit2 and inflateReset2 based on the
  773.     * zlib version number and because this affects handling of certain broken
  774.     * PNG files the -I directives must match.
  775.     *
  776.     * The most likely explanation is that you passed a -I in CFLAGS, this will
  777.     * not work; all the preprocessor directories and in particular all the -I
  778.     * directives must be in CPPFLAGS.
  779.     */
  780. #endif
  781.  
  782. /* This is used for 16 bit gamma tables -- only the top level pointers are
  783.  * const; this could be changed:
  784.  */
  785. typedef const png_uint_16p * png_const_uint_16pp;
  786.  
  787. /* Added to libpng-1.5.7: sRGB conversion tables */
  788. #if defined(PNG_SIMPLIFIED_READ_SUPPORTED) ||\
  789.    defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
  790. #ifdef PNG_SIMPLIFIED_READ_SUPPORTED
  791. PNG_INTERNAL_DATA(const png_uint_16, png_sRGB_table, [256]);
  792.    /* Convert from an sRGB encoded value 0..255 to a 16-bit linear value,
  793.     * 0..65535.  This table gives the closest 16-bit answers (no errors).
  794.     */
  795. #endif
  796.  
  797. PNG_INTERNAL_DATA(const png_uint_16, png_sRGB_base, [512]);
  798. PNG_INTERNAL_DATA(const png_byte, png_sRGB_delta, [512]);
  799.  
  800. #define PNG_sRGB_FROM_LINEAR(linear) ((png_byte)((png_sRGB_base[(linear)>>15] +\
  801.    ((((linear)&0x7fff)*png_sRGB_delta[(linear)>>15])>>12)) >> 8))
  802.    /* Given a value 'linear' in the range 0..255*65535 calculate the 8-bit sRGB
  803.     * encoded value with maximum error 0.646365.  Note that the input is not a
  804.     * 16-bit value; it has been multiplied by 255! */
  805. #endif /* PNG_SIMPLIFIED_READ/WRITE */
  806.  
  807.  
  808. /* Inhibit C++ name-mangling for libpng functions but not for system calls. */
  809. #ifdef __cplusplus
  810. extern "C" {
  811. #endif /* __cplusplus */
  812.  
  813. /* Internal functions; these are not exported from a DLL however because they
  814.  * are used within several of the C source files they have to be C extern.
  815.  *
  816.  * All of these functions must be declared with PNG_INTERNAL_FUNCTION.
  817.  */
  818.  
  819. /* Zlib support */
  820. #define PNG_UNEXPECTED_ZLIB_RETURN (-7)
  821. PNG_INTERNAL_FUNCTION(void, png_zstream_error,(png_structrp png_ptr, int ret),
  822.    PNG_EMPTY);
  823.    /* Used by the zlib handling functions to ensure that z_stream::msg is always
  824.     * set before they return.
  825.     */
  826.  
  827. #ifdef PNG_WRITE_SUPPORTED
  828. PNG_INTERNAL_FUNCTION(void,png_free_buffer_list,(png_structrp png_ptr,
  829.    png_compression_bufferp *list),PNG_EMPTY);
  830.    /* Free the buffer list used by the compressed write code. */
  831. #endif
  832.  
  833. #if defined(PNG_FLOATING_POINT_SUPPORTED) && \
  834.    !defined(PNG_FIXED_POINT_MACRO_SUPPORTED) && \
  835.    (defined(PNG_gAMA_SUPPORTED) || defined(PNG_cHRM_SUPPORTED) || \
  836.    defined(PNG_sCAL_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) || \
  837.    defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)) || \
  838.    (defined(PNG_sCAL_SUPPORTED) && \
  839.    defined(PNG_FLOATING_ARITHMETIC_SUPPORTED))
  840. PNG_INTERNAL_FUNCTION(png_fixed_point,png_fixed,(png_const_structrp png_ptr,
  841.    double fp, png_const_charp text),PNG_EMPTY);
  842. #endif
  843.  
  844. /* Check the user version string for compatibility, returns false if the version
  845.  * numbers aren't compatible.
  846.  */
  847. PNG_INTERNAL_FUNCTION(int,png_user_version_check,(png_structrp png_ptr,
  848.    png_const_charp user_png_ver),PNG_EMPTY);
  849.  
  850. /* Internal base allocator - no messages, NULL on failure to allocate.  This
  851.  * does, however, call the application provided allocator and that could call
  852.  * png_error (although that would be a bug in the application implementation.)
  853.  */
  854. PNG_INTERNAL_FUNCTION(png_voidp,png_malloc_base,(png_const_structrp png_ptr,
  855.    png_alloc_size_t size),PNG_ALLOCATED);
  856.  
  857. #if defined(PNG_TEXT_SUPPORTED) || defined(PNG_sPLT_SUPPORTED) ||\
  858.    defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED)
  859. /* Internal array allocator, outputs no error or warning messages on failure,
  860.  * just returns NULL.  
  861.  */
  862. PNG_INTERNAL_FUNCTION(png_voidp,png_malloc_array,(png_const_structrp png_ptr,
  863.    int nelements, size_t element_size),PNG_ALLOCATED);
  864.  
  865. /* The same but an existing array is extended by add_elements.  This function
  866.  * also memsets the new elements to 0 and copies the old elements.  The old
  867.  * array is not freed or altered.
  868.  */
  869. PNG_INTERNAL_FUNCTION(png_voidp,png_realloc_array,(png_const_structrp png_ptr,
  870.    png_const_voidp array, int old_elements, int add_elements,
  871.    size_t element_size),PNG_ALLOCATED);
  872. #endif /* text, sPLT or unknown chunks */
  873.  
  874. /* Magic to create a struct when there is no struct to call the user supplied
  875.  * memory allocators.  Because error handling has not been set up the memory
  876.  * handlers can't safely call png_error, but this is an obscure and undocumented
  877.  * restriction so libpng has to assume that the 'free' handler, at least, might
  878.  * call png_error.
  879.  */
  880. PNG_INTERNAL_FUNCTION(png_structp,png_create_png_struct,
  881.    (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
  882.     png_error_ptr warn_fn, png_voidp mem_ptr, png_malloc_ptr malloc_fn,
  883.     png_free_ptr free_fn),PNG_ALLOCATED);
  884.  
  885. /* Free memory from internal libpng struct */
  886. PNG_INTERNAL_FUNCTION(void,png_destroy_png_struct,(png_structrp png_ptr),
  887.    PNG_EMPTY);
  888.  
  889. /* Free an allocated jmp_buf (always succeeds) */
  890. PNG_INTERNAL_FUNCTION(void,png_free_jmpbuf,(png_structrp png_ptr),PNG_EMPTY);
  891.  
  892. /* Function to allocate memory for zlib.  PNGAPI is disallowed. */
  893. PNG_INTERNAL_FUNCTION(voidpf,png_zalloc,(voidpf png_ptr, uInt items, uInt size),
  894.    PNG_ALLOCATED);
  895.  
  896. /* Function to free memory for zlib.  PNGAPI is disallowed. */
  897. PNG_INTERNAL_FUNCTION(void,png_zfree,(voidpf png_ptr, voidpf ptr),PNG_EMPTY);
  898.  
  899. /* Next four functions are used internally as callbacks.  PNGCBAPI is required
  900.  * but not PNG_EXPORT.  PNGAPI added at libpng version 1.2.3, changed to
  901.  * PNGCBAPI at 1.5.0
  902.  */
  903.  
  904. PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_default_read_data,(png_structp png_ptr,
  905.     png_bytep data, png_size_t length),PNG_EMPTY);
  906.  
  907. #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
  908. PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_push_fill_buffer,(png_structp png_ptr,
  909.     png_bytep buffer, png_size_t length),PNG_EMPTY);
  910. #endif
  911.  
  912. PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_default_write_data,(png_structp png_ptr,
  913.     png_bytep data, png_size_t length),PNG_EMPTY);
  914.  
  915. #ifdef PNG_WRITE_FLUSH_SUPPORTED
  916. #  ifdef PNG_STDIO_SUPPORTED
  917. PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_default_flush,(png_structp png_ptr),
  918.    PNG_EMPTY);
  919. #  endif
  920. #endif
  921.  
  922. /* Reset the CRC variable */
  923. PNG_INTERNAL_FUNCTION(void,png_reset_crc,(png_structrp png_ptr),PNG_EMPTY);
  924.  
  925. /* Write the "data" buffer to whatever output you are using */
  926. PNG_INTERNAL_FUNCTION(void,png_write_data,(png_structrp png_ptr,
  927.     png_const_bytep data, png_size_t length),PNG_EMPTY);
  928.  
  929. /* Read and check the PNG file signature */
  930. PNG_INTERNAL_FUNCTION(void,png_read_sig,(png_structrp png_ptr,
  931.    png_inforp info_ptr),PNG_EMPTY);
  932.  
  933. /* Read the chunk header (length + type name) */
  934. PNG_INTERNAL_FUNCTION(png_uint_32,png_read_chunk_header,(png_structrp png_ptr),
  935.    PNG_EMPTY);
  936.  
  937. /* Read data from whatever input you are using into the "data" buffer */
  938. PNG_INTERNAL_FUNCTION(void,png_read_data,(png_structrp png_ptr, png_bytep data,
  939.     png_size_t length),PNG_EMPTY);
  940.  
  941. /* Read bytes into buf, and update png_ptr->crc */
  942. PNG_INTERNAL_FUNCTION(void,png_crc_read,(png_structrp png_ptr, png_bytep buf,
  943.     png_uint_32 length),PNG_EMPTY);
  944.  
  945. /* Read "skip" bytes, read the file crc, and (optionally) verify png_ptr->crc */
  946. PNG_INTERNAL_FUNCTION(int,png_crc_finish,(png_structrp png_ptr,
  947.    png_uint_32 skip),PNG_EMPTY);
  948.  
  949. /* Read the CRC from the file and compare it to the libpng calculated CRC */
  950. PNG_INTERNAL_FUNCTION(int,png_crc_error,(png_structrp png_ptr),PNG_EMPTY);
  951.  
  952. /* Calculate the CRC over a section of data.  Note that we are only
  953.  * passing a maximum of 64K on systems that have this as a memory limit,
  954.  * since this is the maximum buffer size we can specify.
  955.  */
  956. PNG_INTERNAL_FUNCTION(void,png_calculate_crc,(png_structrp png_ptr,
  957.    png_const_bytep ptr, png_size_t length),PNG_EMPTY);
  958.  
  959. #ifdef PNG_WRITE_FLUSH_SUPPORTED
  960. PNG_INTERNAL_FUNCTION(void,png_flush,(png_structrp png_ptr),PNG_EMPTY);
  961. #endif
  962.  
  963. /* Write various chunks */
  964.  
  965. /* Write the IHDR chunk, and update the png_struct with the necessary
  966.  * information.
  967.  */
  968. PNG_INTERNAL_FUNCTION(void,png_write_IHDR,(png_structrp png_ptr,
  969.    png_uint_32 width, png_uint_32 height, int bit_depth, int color_type,
  970.    int compression_method, int filter_method, int interlace_method),PNG_EMPTY);
  971.  
  972. PNG_INTERNAL_FUNCTION(void,png_write_PLTE,(png_structrp png_ptr,
  973.    png_const_colorp palette, png_uint_32 num_pal),PNG_EMPTY);
  974.  
  975. PNG_INTERNAL_FUNCTION(void,png_compress_IDAT,(png_structrp png_ptr,
  976.    png_const_bytep row_data, png_alloc_size_t row_data_length, int flush),
  977.    PNG_EMPTY);
  978.  
  979. PNG_INTERNAL_FUNCTION(void,png_write_IEND,(png_structrp png_ptr),PNG_EMPTY);
  980.  
  981. #ifdef PNG_WRITE_gAMA_SUPPORTED
  982. PNG_INTERNAL_FUNCTION(void,png_write_gAMA_fixed,(png_structrp png_ptr,
  983.     png_fixed_point file_gamma),PNG_EMPTY);
  984. #endif
  985.  
  986. #ifdef PNG_WRITE_sBIT_SUPPORTED
  987. PNG_INTERNAL_FUNCTION(void,png_write_sBIT,(png_structrp png_ptr,
  988.     png_const_color_8p sbit, int color_type),PNG_EMPTY);
  989. #endif
  990.  
  991. #ifdef PNG_WRITE_cHRM_SUPPORTED
  992. PNG_INTERNAL_FUNCTION(void,png_write_cHRM_fixed,(png_structrp png_ptr,
  993.     const png_xy *xy), PNG_EMPTY);
  994.     /* The xy value must have been previously validated */
  995. #endif
  996.  
  997. #ifdef PNG_WRITE_sRGB_SUPPORTED
  998. PNG_INTERNAL_FUNCTION(void,png_write_sRGB,(png_structrp png_ptr,
  999.     int intent),PNG_EMPTY);
  1000. #endif
  1001.  
  1002. #ifdef PNG_WRITE_iCCP_SUPPORTED
  1003. PNG_INTERNAL_FUNCTION(void,png_write_iCCP,(png_structrp png_ptr,
  1004.    png_const_charp name, png_const_bytep profile), PNG_EMPTY);
  1005.    /* The profile must have been previously validated for correctness, the
  1006.     * length comes from the first four bytes.  Only the base, deflate,
  1007.     * compression is supported.
  1008.     */
  1009. #endif
  1010.  
  1011. #ifdef PNG_WRITE_sPLT_SUPPORTED
  1012. PNG_INTERNAL_FUNCTION(void,png_write_sPLT,(png_structrp png_ptr,
  1013.     png_const_sPLT_tp palette),PNG_EMPTY);
  1014. #endif
  1015.  
  1016. #ifdef PNG_WRITE_tRNS_SUPPORTED
  1017. PNG_INTERNAL_FUNCTION(void,png_write_tRNS,(png_structrp png_ptr,
  1018.     png_const_bytep trans, png_const_color_16p values, int number,
  1019.     int color_type),PNG_EMPTY);
  1020. #endif
  1021.  
  1022. #ifdef PNG_WRITE_bKGD_SUPPORTED
  1023. PNG_INTERNAL_FUNCTION(void,png_write_bKGD,(png_structrp png_ptr,
  1024.     png_const_color_16p values, int color_type),PNG_EMPTY);
  1025. #endif
  1026.  
  1027. #ifdef PNG_WRITE_hIST_SUPPORTED
  1028. PNG_INTERNAL_FUNCTION(void,png_write_hIST,(png_structrp png_ptr,
  1029.     png_const_uint_16p hist, int num_hist),PNG_EMPTY);
  1030. #endif
  1031.  
  1032. /* Chunks that have keywords */
  1033. #ifdef PNG_WRITE_tEXt_SUPPORTED
  1034. PNG_INTERNAL_FUNCTION(void,png_write_tEXt,(png_structrp png_ptr,
  1035.    png_const_charp key, png_const_charp text, png_size_t text_len),PNG_EMPTY);
  1036. #endif
  1037.  
  1038. #ifdef PNG_WRITE_zTXt_SUPPORTED
  1039. PNG_INTERNAL_FUNCTION(void,png_write_zTXt,(png_structrp png_ptr, png_const_charp
  1040.     key, png_const_charp text, png_size_t text_len, int compression),PNG_EMPTY);
  1041. #endif
  1042.  
  1043. #ifdef PNG_WRITE_iTXt_SUPPORTED
  1044. PNG_INTERNAL_FUNCTION(void,png_write_iTXt,(png_structrp png_ptr,
  1045.     int compression, png_const_charp key, png_const_charp lang,
  1046.     png_const_charp lang_key, png_const_charp text),PNG_EMPTY);
  1047. #endif
  1048.  
  1049. #ifdef PNG_TEXT_SUPPORTED  /* Added at version 1.0.14 and 1.2.4 */
  1050. PNG_INTERNAL_FUNCTION(int,png_set_text_2,(png_const_structrp png_ptr,
  1051.     png_inforp info_ptr, png_const_textp text_ptr, int num_text),PNG_EMPTY);
  1052. #endif
  1053.  
  1054. #ifdef PNG_WRITE_oFFs_SUPPORTED
  1055. PNG_INTERNAL_FUNCTION(void,png_write_oFFs,(png_structrp png_ptr,
  1056.     png_int_32 x_offset, png_int_32 y_offset, int unit_type),PNG_EMPTY);
  1057. #endif
  1058.  
  1059. #ifdef PNG_WRITE_pCAL_SUPPORTED
  1060. PNG_INTERNAL_FUNCTION(void,png_write_pCAL,(png_structrp png_ptr,
  1061.     png_charp purpose, png_int_32 X0, png_int_32 X1, int type, int nparams,
  1062.     png_const_charp units, png_charpp params),PNG_EMPTY);
  1063. #endif
  1064.  
  1065. #ifdef PNG_WRITE_pHYs_SUPPORTED
  1066. PNG_INTERNAL_FUNCTION(void,png_write_pHYs,(png_structrp png_ptr,
  1067.     png_uint_32 x_pixels_per_unit, png_uint_32 y_pixels_per_unit,
  1068.     int unit_type),PNG_EMPTY);
  1069. #endif
  1070.  
  1071. #ifdef PNG_WRITE_tIME_SUPPORTED
  1072. PNG_INTERNAL_FUNCTION(void,png_write_tIME,(png_structrp png_ptr,
  1073.     png_const_timep mod_time),PNG_EMPTY);
  1074. #endif
  1075.  
  1076. #ifdef PNG_WRITE_sCAL_SUPPORTED
  1077. PNG_INTERNAL_FUNCTION(void,png_write_sCAL_s,(png_structrp png_ptr,
  1078.     int unit, png_const_charp width, png_const_charp height),PNG_EMPTY);
  1079. #endif
  1080.  
  1081. /* Called when finished processing a row of data */
  1082. PNG_INTERNAL_FUNCTION(void,png_write_finish_row,(png_structrp png_ptr),
  1083.     PNG_EMPTY);
  1084.  
  1085. /* Internal use only.   Called before first row of data */
  1086. PNG_INTERNAL_FUNCTION(void,png_write_start_row,(png_structrp png_ptr),
  1087.     PNG_EMPTY);
  1088.  
  1089. /* Combine a row of data, dealing with alpha, etc. if requested.  'row' is an
  1090.  * array of png_ptr->width pixels.  If the image is not interlaced or this
  1091.  * is the final pass this just does a memcpy, otherwise the "display" flag
  1092.  * is used to determine whether to copy pixels that are not in the current pass.
  1093.  *
  1094.  * Because 'png_do_read_interlace' (below) replicates pixels this allows this
  1095.  * function to achieve the documented 'blocky' appearance during interlaced read
  1096.  * if display is 1 and the 'sparkle' appearance, where existing pixels in 'row'
  1097.  * are not changed if they are not in the current pass, when display is 0.
  1098.  *
  1099.  * 'display' must be 0 or 1, otherwise the memcpy will be done regardless.
  1100.  *
  1101.  * The API always reads from the png_struct row buffer and always assumes that
  1102.  * it is full width (png_do_read_interlace has already been called.)
  1103.  *
  1104.  * This function is only ever used to write to row buffers provided by the
  1105.  * caller of the relevant libpng API and the row must have already been
  1106.  * transformed by the read transformations.
  1107.  *
  1108.  * The PNG_USE_COMPILE_TIME_MASKS option causes generation of pre-computed
  1109.  * bitmasks for use within the code, otherwise runtime generated masks are used.
  1110.  * The default is compile time masks.
  1111.  */
  1112. #ifndef PNG_USE_COMPILE_TIME_MASKS
  1113. #  define PNG_USE_COMPILE_TIME_MASKS 1
  1114. #endif
  1115. PNG_INTERNAL_FUNCTION(void,png_combine_row,(png_const_structrp png_ptr,
  1116.     png_bytep row, int display),PNG_EMPTY);
  1117.  
  1118. #ifdef PNG_READ_INTERLACING_SUPPORTED
  1119. /* Expand an interlaced row: the 'row_info' describes the pass data that has
  1120.  * been read in and must correspond to the pixels in 'row', the pixels are
  1121.  * expanded (moved apart) in 'row' to match the final layout, when doing this
  1122.  * the pixels are *replicated* to the intervening space.  This is essential for
  1123.  * the correct operation of png_combine_row, above.
  1124.  */
  1125. PNG_INTERNAL_FUNCTION(void,png_do_read_interlace,(png_row_infop row_info,
  1126.     png_bytep row, int pass, png_uint_32 transformations),PNG_EMPTY);
  1127. #endif
  1128.  
  1129. /* GRR TO DO (2.0 or whenever):  simplify other internal calling interfaces */
  1130.  
  1131. #ifdef PNG_WRITE_INTERLACING_SUPPORTED
  1132. /* Grab pixels out of a row for an interlaced pass */
  1133. PNG_INTERNAL_FUNCTION(void,png_do_write_interlace,(png_row_infop row_info,
  1134.     png_bytep row, int pass),PNG_EMPTY);
  1135. #endif
  1136.  
  1137. /* Unfilter a row: check the filter value before calling this, there is no point
  1138.  * calling it for PNG_FILTER_VALUE_NONE.
  1139.  */
  1140. PNG_INTERNAL_FUNCTION(void,png_read_filter_row,(png_structrp pp, png_row_infop
  1141.     row_info, png_bytep row, png_const_bytep prev_row, int filter),PNG_EMPTY);
  1142.  
  1143. PNG_INTERNAL_FUNCTION(void,png_read_filter_row_up_neon,(png_row_infop row_info,
  1144.     png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
  1145. PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub3_neon,(png_row_infop
  1146.     row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
  1147. PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub4_neon,(png_row_infop
  1148.     row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
  1149. PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg3_neon,(png_row_infop
  1150.     row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
  1151. PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg4_neon,(png_row_infop
  1152.     row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
  1153. PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth3_neon,(png_row_infop
  1154.     row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
  1155. PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_neon,(png_row_infop
  1156.     row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
  1157.  
  1158. /* Choose the best filter to use and filter the row data */
  1159. PNG_INTERNAL_FUNCTION(void,png_write_find_filter,(png_structrp png_ptr,
  1160.     png_row_infop row_info),PNG_EMPTY);
  1161.  
  1162. #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
  1163. PNG_INTERNAL_FUNCTION(void,png_read_IDAT_data,(png_structrp png_ptr,
  1164.    png_bytep output, png_alloc_size_t avail_out),PNG_EMPTY);
  1165.    /* Read 'avail_out' bytes of data from the IDAT stream.  If the output buffer
  1166.     * is NULL the function checks, instead, for the end of the stream.  In this
  1167.     * case a benign error will be issued if the stream end is not found or if
  1168.     * extra data has to be consumed.
  1169.     */
  1170. PNG_INTERNAL_FUNCTION(void,png_read_finish_IDAT,(png_structrp png_ptr),
  1171.    PNG_EMPTY);
  1172.    /* This cleans up when the IDAT LZ stream does not end when the last image
  1173.     * byte is read; there is still some pending input.
  1174.     */
  1175.  
  1176. PNG_INTERNAL_FUNCTION(void,png_read_finish_row,(png_structrp png_ptr),
  1177.    PNG_EMPTY);
  1178.    /* Finish a row while reading, dealing with interlacing passes, etc. */
  1179. #endif
  1180.  
  1181. /* Initialize the row buffers, etc. */
  1182. PNG_INTERNAL_FUNCTION(void,png_read_start_row,(png_structrp png_ptr),PNG_EMPTY);
  1183.  
  1184. #ifdef PNG_READ_TRANSFORMS_SUPPORTED
  1185. /* Optional call to update the users info structure */
  1186. PNG_INTERNAL_FUNCTION(void,png_read_transform_info,(png_structrp png_ptr,
  1187.     png_inforp info_ptr),PNG_EMPTY);
  1188. #endif
  1189.  
  1190. /* These are the functions that do the transformations */
  1191. #ifdef PNG_READ_FILLER_SUPPORTED
  1192. PNG_INTERNAL_FUNCTION(void,png_do_read_filler,(png_row_infop row_info,
  1193.     png_bytep row, png_uint_32 filler, png_uint_32 flags),PNG_EMPTY);
  1194. #endif
  1195.  
  1196. #ifdef PNG_READ_SWAP_ALPHA_SUPPORTED
  1197. PNG_INTERNAL_FUNCTION(void,png_do_read_swap_alpha,(png_row_infop row_info,
  1198.     png_bytep row),PNG_EMPTY);
  1199. #endif
  1200.  
  1201. #ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED
  1202. PNG_INTERNAL_FUNCTION(void,png_do_write_swap_alpha,(png_row_infop row_info,
  1203.     png_bytep row),PNG_EMPTY);
  1204. #endif
  1205.  
  1206. #ifdef PNG_READ_INVERT_ALPHA_SUPPORTED
  1207. PNG_INTERNAL_FUNCTION(void,png_do_read_invert_alpha,(png_row_infop row_info,
  1208.     png_bytep row),PNG_EMPTY);
  1209. #endif
  1210.  
  1211. #ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
  1212. PNG_INTERNAL_FUNCTION(void,png_do_write_invert_alpha,(png_row_infop row_info,
  1213.     png_bytep row),PNG_EMPTY);
  1214. #endif
  1215.  
  1216. #if defined(PNG_WRITE_FILLER_SUPPORTED) || \
  1217.     defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
  1218. PNG_INTERNAL_FUNCTION(void,png_do_strip_channel,(png_row_infop row_info,
  1219.     png_bytep row, int at_start),PNG_EMPTY);
  1220. #endif
  1221.  
  1222. #ifdef PNG_16BIT_SUPPORTED
  1223. #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
  1224. PNG_INTERNAL_FUNCTION(void,png_do_swap,(png_row_infop row_info,
  1225.     png_bytep row),PNG_EMPTY);
  1226. #endif
  1227. #endif
  1228.  
  1229. #if defined(PNG_READ_PACKSWAP_SUPPORTED) || \
  1230.     defined(PNG_WRITE_PACKSWAP_SUPPORTED)
  1231. PNG_INTERNAL_FUNCTION(void,png_do_packswap,(png_row_infop row_info,
  1232.     png_bytep row),PNG_EMPTY);
  1233. #endif
  1234.  
  1235. #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
  1236. PNG_INTERNAL_FUNCTION(int,png_do_rgb_to_gray,(png_structrp png_ptr,
  1237.     png_row_infop row_info, png_bytep row),PNG_EMPTY);
  1238. #endif
  1239.  
  1240. #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
  1241. PNG_INTERNAL_FUNCTION(void,png_do_gray_to_rgb,(png_row_infop row_info,
  1242.     png_bytep row),PNG_EMPTY);
  1243. #endif
  1244.  
  1245. #ifdef PNG_READ_PACK_SUPPORTED
  1246. PNG_INTERNAL_FUNCTION(void,png_do_unpack,(png_row_infop row_info,
  1247.     png_bytep row),PNG_EMPTY);
  1248. #endif
  1249.  
  1250. #ifdef PNG_READ_SHIFT_SUPPORTED
  1251. PNG_INTERNAL_FUNCTION(void,png_do_unshift,(png_row_infop row_info,
  1252.     png_bytep row, png_const_color_8p sig_bits),PNG_EMPTY);
  1253. #endif
  1254.  
  1255. #if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
  1256. PNG_INTERNAL_FUNCTION(void,png_do_invert,(png_row_infop row_info,
  1257.     png_bytep row),PNG_EMPTY);
  1258. #endif
  1259.  
  1260. #ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
  1261. PNG_INTERNAL_FUNCTION(void,png_do_scale_16_to_8,(png_row_infop row_info,
  1262.     png_bytep row),PNG_EMPTY);
  1263. #endif
  1264.  
  1265. #ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
  1266. PNG_INTERNAL_FUNCTION(void,png_do_chop,(png_row_infop row_info,
  1267.     png_bytep row),PNG_EMPTY);
  1268. #endif
  1269.  
  1270. #ifdef PNG_READ_QUANTIZE_SUPPORTED
  1271. PNG_INTERNAL_FUNCTION(void,png_do_quantize,(png_row_infop row_info,
  1272.     png_bytep row, png_const_bytep palette_lookup,
  1273.     png_const_bytep quantize_lookup),PNG_EMPTY);
  1274.  
  1275. #  ifdef PNG_CORRECT_PALETTE_SUPPORTED
  1276. PNG_INTERNAL_FUNCTION(void,png_correct_palette,(png_structrp png_ptr,
  1277.     png_colorp palette, int num_palette),PNG_EMPTY);
  1278. #  endif
  1279. #endif
  1280.  
  1281. #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
  1282. PNG_INTERNAL_FUNCTION(void,png_do_bgr,(png_row_infop row_info,
  1283.     png_bytep row),PNG_EMPTY);
  1284. #endif
  1285.  
  1286. #ifdef PNG_WRITE_PACK_SUPPORTED
  1287. PNG_INTERNAL_FUNCTION(void,png_do_pack,(png_row_infop row_info,
  1288.    png_bytep row, png_uint_32 bit_depth),PNG_EMPTY);
  1289. #endif
  1290.  
  1291. #ifdef PNG_WRITE_SHIFT_SUPPORTED
  1292. PNG_INTERNAL_FUNCTION(void,png_do_shift,(png_row_infop row_info,
  1293.     png_bytep row, png_const_color_8p bit_depth),PNG_EMPTY);
  1294. #endif
  1295.  
  1296. #if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\
  1297.     defined(PNG_READ_ALPHA_MODE_SUPPORTED)
  1298. PNG_INTERNAL_FUNCTION(void,png_do_compose,(png_row_infop row_info,
  1299.     png_bytep row, png_structrp png_ptr),PNG_EMPTY);
  1300. #endif
  1301.  
  1302. #ifdef PNG_READ_GAMMA_SUPPORTED
  1303. PNG_INTERNAL_FUNCTION(void,png_do_gamma,(png_row_infop row_info,
  1304.     png_bytep row, png_structrp png_ptr),PNG_EMPTY);
  1305. #endif
  1306.  
  1307. #ifdef PNG_READ_ALPHA_MODE_SUPPORTED
  1308. PNG_INTERNAL_FUNCTION(void,png_do_encode_alpha,(png_row_infop row_info,
  1309.    png_bytep row, png_structrp png_ptr),PNG_EMPTY);
  1310. #endif
  1311.  
  1312. #ifdef PNG_READ_EXPAND_SUPPORTED
  1313. PNG_INTERNAL_FUNCTION(void,png_do_expand_palette,(png_row_infop row_info,
  1314.     png_bytep row, png_const_colorp palette, png_const_bytep trans,
  1315.     int num_trans),PNG_EMPTY);
  1316. PNG_INTERNAL_FUNCTION(void,png_do_expand,(png_row_infop row_info,
  1317.     png_bytep row, png_const_color_16p trans_color),PNG_EMPTY);
  1318. #endif
  1319.  
  1320. #ifdef PNG_READ_EXPAND_16_SUPPORTED
  1321. PNG_INTERNAL_FUNCTION(void,png_do_expand_16,(png_row_infop row_info,
  1322.     png_bytep row),PNG_EMPTY);
  1323. #endif
  1324.  
  1325. /* The following decodes the appropriate chunks, and does error correction,
  1326.  * then calls the appropriate callback for the chunk if it is valid.
  1327.  */
  1328.  
  1329. /* Decode the IHDR chunk */
  1330. PNG_INTERNAL_FUNCTION(void,png_handle_IHDR,(png_structrp png_ptr,
  1331.     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
  1332. PNG_INTERNAL_FUNCTION(void,png_handle_PLTE,(png_structrp png_ptr,
  1333.     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
  1334. PNG_INTERNAL_FUNCTION(void,png_handle_IEND,(png_structrp png_ptr,
  1335.     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
  1336.  
  1337. #ifdef PNG_READ_bKGD_SUPPORTED
  1338. PNG_INTERNAL_FUNCTION(void,png_handle_bKGD,(png_structrp png_ptr,
  1339.     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
  1340. #endif
  1341.  
  1342. #ifdef PNG_READ_cHRM_SUPPORTED
  1343. PNG_INTERNAL_FUNCTION(void,png_handle_cHRM,(png_structrp png_ptr,
  1344.     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
  1345. #endif
  1346.  
  1347. #ifdef PNG_READ_gAMA_SUPPORTED
  1348. PNG_INTERNAL_FUNCTION(void,png_handle_gAMA,(png_structrp png_ptr,
  1349.     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
  1350. #endif
  1351.  
  1352. #ifdef PNG_READ_hIST_SUPPORTED
  1353. PNG_INTERNAL_FUNCTION(void,png_handle_hIST,(png_structrp png_ptr,
  1354.     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
  1355. #endif
  1356.  
  1357. #ifdef PNG_READ_iCCP_SUPPORTED
  1358. PNG_INTERNAL_FUNCTION(void,png_handle_iCCP,(png_structrp png_ptr,
  1359.     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
  1360. #endif /* PNG_READ_iCCP_SUPPORTED */
  1361.  
  1362. #ifdef PNG_READ_iTXt_SUPPORTED
  1363. PNG_INTERNAL_FUNCTION(void,png_handle_iTXt,(png_structrp png_ptr,
  1364.     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
  1365. #endif
  1366.  
  1367. #ifdef PNG_READ_oFFs_SUPPORTED
  1368. PNG_INTERNAL_FUNCTION(void,png_handle_oFFs,(png_structrp png_ptr,
  1369.     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
  1370. #endif
  1371.  
  1372. #ifdef PNG_READ_pCAL_SUPPORTED
  1373. PNG_INTERNAL_FUNCTION(void,png_handle_pCAL,(png_structrp png_ptr,
  1374.     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
  1375. #endif
  1376.  
  1377. #ifdef PNG_READ_pHYs_SUPPORTED
  1378. PNG_INTERNAL_FUNCTION(void,png_handle_pHYs,(png_structrp png_ptr,
  1379.     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
  1380. #endif
  1381.  
  1382. #ifdef PNG_READ_sBIT_SUPPORTED
  1383. PNG_INTERNAL_FUNCTION(void,png_handle_sBIT,(png_structrp png_ptr,
  1384.     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
  1385. #endif
  1386.  
  1387. #ifdef PNG_READ_sCAL_SUPPORTED
  1388. PNG_INTERNAL_FUNCTION(void,png_handle_sCAL,(png_structrp png_ptr,
  1389.     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
  1390. #endif
  1391.  
  1392. #ifdef PNG_READ_sPLT_SUPPORTED
  1393. PNG_INTERNAL_FUNCTION(void,png_handle_sPLT,(png_structrp png_ptr,
  1394.     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
  1395. #endif /* PNG_READ_sPLT_SUPPORTED */
  1396.  
  1397. #ifdef PNG_READ_sRGB_SUPPORTED
  1398. PNG_INTERNAL_FUNCTION(void,png_handle_sRGB,(png_structrp png_ptr,
  1399.     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
  1400. #endif
  1401.  
  1402. #ifdef PNG_READ_tEXt_SUPPORTED
  1403. PNG_INTERNAL_FUNCTION(void,png_handle_tEXt,(png_structrp png_ptr,
  1404.     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
  1405. #endif
  1406.  
  1407. #ifdef PNG_READ_tIME_SUPPORTED
  1408. PNG_INTERNAL_FUNCTION(void,png_handle_tIME,(png_structrp png_ptr,
  1409.     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
  1410. #endif
  1411.  
  1412. #ifdef PNG_READ_tRNS_SUPPORTED
  1413. PNG_INTERNAL_FUNCTION(void,png_handle_tRNS,(png_structrp png_ptr,
  1414.     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
  1415. #endif
  1416.  
  1417. #ifdef PNG_READ_zTXt_SUPPORTED
  1418. PNG_INTERNAL_FUNCTION(void,png_handle_zTXt,(png_structrp png_ptr,
  1419.     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
  1420. #endif
  1421.  
  1422. PNG_INTERNAL_FUNCTION(void,png_check_chunk_name,(png_structrp png_ptr,
  1423.     png_uint_32 chunk_name),PNG_EMPTY);
  1424.  
  1425. #ifdef PNG_READ_SUPPORTED
  1426. PNG_INTERNAL_FUNCTION(void,png_handle_unknown,(png_structrp png_ptr,
  1427.     png_inforp info_ptr, png_uint_32 length, int keep),PNG_EMPTY);
  1428.    /* This is the function that gets called for unknown chunks.  The 'keep'
  1429.     * argument is either non-zero for a known chunk that has been set to be
  1430.     * handled as unknown or zero for an unknown chunk.  By default the function
  1431.     * just skips the chunk or errors out if it is critical.
  1432.     */
  1433.  
  1434. #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
  1435. PNG_INTERNAL_FUNCTION(int,png_chunk_unknown_handling,
  1436.     (png_const_structrp png_ptr, png_uint_32 chunk_name),PNG_EMPTY);
  1437.    /* Exactly as the API png_handle_as_unknown() except that the argument is a
  1438.     * 32-bit chunk name, not a string.
  1439.     */
  1440. #endif /* PNG_HANDLE_AS_UNKNOWN_SUPPORTED */
  1441. #endif /* PNG_READ_SUPPORTED */
  1442.  
  1443. /* Handle the transformations for reading and writing */
  1444. #ifdef PNG_READ_TRANSFORMS_SUPPORTED
  1445. PNG_INTERNAL_FUNCTION(void,png_do_read_transformations,(png_structrp png_ptr,
  1446.    png_row_infop row_info),PNG_EMPTY);
  1447. #endif
  1448. #ifdef PNG_WRITE_TRANSFORMS_SUPPORTED
  1449. PNG_INTERNAL_FUNCTION(void,png_do_write_transformations,(png_structrp png_ptr,
  1450.    png_row_infop row_info),PNG_EMPTY);
  1451. #endif
  1452.  
  1453. #ifdef PNG_READ_TRANSFORMS_SUPPORTED
  1454. PNG_INTERNAL_FUNCTION(void,png_init_read_transformations,(png_structrp png_ptr),
  1455.     PNG_EMPTY);
  1456. #endif
  1457.  
  1458. #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
  1459. PNG_INTERNAL_FUNCTION(void,png_push_read_chunk,(png_structrp png_ptr,
  1460.     png_inforp info_ptr),PNG_EMPTY);
  1461. PNG_INTERNAL_FUNCTION(void,png_push_read_sig,(png_structrp png_ptr,
  1462.     png_inforp info_ptr),PNG_EMPTY);
  1463. PNG_INTERNAL_FUNCTION(void,png_push_check_crc,(png_structrp png_ptr),PNG_EMPTY);
  1464. PNG_INTERNAL_FUNCTION(void,png_push_crc_skip,(png_structrp png_ptr,
  1465.     png_uint_32 length),PNG_EMPTY);
  1466. PNG_INTERNAL_FUNCTION(void,png_push_crc_finish,(png_structrp png_ptr),
  1467.     PNG_EMPTY);
  1468. PNG_INTERNAL_FUNCTION(void,png_push_save_buffer,(png_structrp png_ptr),
  1469.     PNG_EMPTY);
  1470. PNG_INTERNAL_FUNCTION(void,png_push_restore_buffer,(png_structrp png_ptr,
  1471.     png_bytep buffer, png_size_t buffer_length),PNG_EMPTY);
  1472. PNG_INTERNAL_FUNCTION(void,png_push_read_IDAT,(png_structrp png_ptr),PNG_EMPTY);
  1473. PNG_INTERNAL_FUNCTION(void,png_process_IDAT_data,(png_structrp png_ptr,
  1474.     png_bytep buffer, png_size_t buffer_length),PNG_EMPTY);
  1475. PNG_INTERNAL_FUNCTION(void,png_push_process_row,(png_structrp png_ptr),
  1476.     PNG_EMPTY);
  1477. PNG_INTERNAL_FUNCTION(void,png_push_handle_unknown,(png_structrp png_ptr,
  1478.    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
  1479. PNG_INTERNAL_FUNCTION(void,png_push_have_info,(png_structrp png_ptr,
  1480.    png_inforp info_ptr),PNG_EMPTY);
  1481. PNG_INTERNAL_FUNCTION(void,png_push_have_end,(png_structrp png_ptr,
  1482.    png_inforp info_ptr),PNG_EMPTY);
  1483. PNG_INTERNAL_FUNCTION(void,png_push_have_row,(png_structrp png_ptr,
  1484.      png_bytep row),PNG_EMPTY);
  1485. PNG_INTERNAL_FUNCTION(void,png_push_read_end,(png_structrp png_ptr,
  1486.     png_inforp info_ptr),PNG_EMPTY);
  1487. PNG_INTERNAL_FUNCTION(void,png_process_some_data,(png_structrp png_ptr,
  1488.     png_inforp info_ptr),PNG_EMPTY);
  1489. PNG_INTERNAL_FUNCTION(void,png_read_push_finish_row,(png_structrp png_ptr),
  1490.     PNG_EMPTY);
  1491. #  ifdef PNG_READ_tEXt_SUPPORTED
  1492. PNG_INTERNAL_FUNCTION(void,png_push_handle_tEXt,(png_structrp png_ptr,
  1493.     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
  1494. PNG_INTERNAL_FUNCTION(void,png_push_read_tEXt,(png_structrp png_ptr,
  1495.     png_inforp info_ptr),PNG_EMPTY);
  1496. #  endif
  1497. #  ifdef PNG_READ_zTXt_SUPPORTED
  1498. PNG_INTERNAL_FUNCTION(void,png_push_handle_zTXt,(png_structrp png_ptr,
  1499.     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
  1500. PNG_INTERNAL_FUNCTION(void,png_push_read_zTXt,(png_structrp png_ptr,
  1501.     png_inforp info_ptr),PNG_EMPTY);
  1502. #  endif
  1503. #  ifdef PNG_READ_iTXt_SUPPORTED
  1504. PNG_INTERNAL_FUNCTION(void,png_push_handle_iTXt,(png_structrp png_ptr,
  1505.     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
  1506. PNG_INTERNAL_FUNCTION(void,png_push_read_iTXt,(png_structrp png_ptr,
  1507.     png_inforp info_ptr),PNG_EMPTY);
  1508. #  endif
  1509.  
  1510. #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
  1511.  
  1512. #ifdef PNG_MNG_FEATURES_SUPPORTED
  1513. PNG_INTERNAL_FUNCTION(void,png_do_read_intrapixel,(png_row_infop row_info,
  1514.     png_bytep row),PNG_EMPTY);
  1515. PNG_INTERNAL_FUNCTION(void,png_do_write_intrapixel,(png_row_infop row_info,
  1516.     png_bytep row),PNG_EMPTY);
  1517. #endif
  1518.  
  1519. /* Added at libpng version 1.6.0 */
  1520. #ifdef PNG_GAMMA_SUPPORTED
  1521. PNG_INTERNAL_FUNCTION(void,png_colorspace_set_gamma,(png_const_structrp png_ptr,
  1522.     png_colorspacerp colorspace, png_fixed_point gAMA), PNG_EMPTY);
  1523.    /* Set the colorspace gamma with a value provided by the application or by
  1524.     * the gAMA chunk on read.  The value will override anything set by an ICC
  1525.     * profile.
  1526.     */
  1527.  
  1528. PNG_INTERNAL_FUNCTION(void,png_colorspace_sync_info,(png_const_structrp png_ptr,
  1529.     png_inforp info_ptr), PNG_EMPTY);
  1530.     /* Synchronize the info 'valid' flags with the colorspace */
  1531.  
  1532. PNG_INTERNAL_FUNCTION(void,png_colorspace_sync,(png_const_structrp png_ptr,
  1533.     png_inforp info_ptr), PNG_EMPTY);
  1534.     /* Copy the png_struct colorspace to the info_struct and call the above to
  1535.      * synchronize the flags.  Checks for NULL info_ptr and does nothing.
  1536.      */
  1537. #endif
  1538.  
  1539. /* Added at libpng version 1.4.0 */
  1540. #ifdef PNG_COLORSPACE_SUPPORTED
  1541. /* These internal functions are for maintaining the colorspace structure within
  1542.  * a png_info or png_struct (or, indeed, both).
  1543.  */
  1544. PNG_INTERNAL_FUNCTION(int,png_colorspace_set_chromaticities,
  1545.    (png_const_structrp png_ptr, png_colorspacerp colorspace, const png_xy *xy,
  1546.     int preferred), PNG_EMPTY);
  1547.  
  1548. PNG_INTERNAL_FUNCTION(int,png_colorspace_set_endpoints,
  1549.    (png_const_structrp png_ptr, png_colorspacerp colorspace, const png_XYZ *XYZ,
  1550.     int preferred), PNG_EMPTY);
  1551.  
  1552. #ifdef PNG_sRGB_SUPPORTED
  1553. PNG_INTERNAL_FUNCTION(int,png_colorspace_set_sRGB,(png_const_structrp png_ptr,
  1554.    png_colorspacerp colorspace, int intent), PNG_EMPTY);
  1555.    /* This does set the colorspace gAMA and cHRM values too, but doesn't set the
  1556.     * flags to write them, if it returns false there was a problem and an error
  1557.     * message has already been output (but the colorspace may still need to be
  1558.     * synced to record the invalid flag).
  1559.     */
  1560. #endif /* sRGB */
  1561.  
  1562. #ifdef PNG_iCCP_SUPPORTED
  1563. PNG_INTERNAL_FUNCTION(int,png_colorspace_set_ICC,(png_const_structrp png_ptr,
  1564.    png_colorspacerp colorspace, png_const_charp name,
  1565.    png_uint_32 profile_length, png_const_bytep profile, int color_type),
  1566.    PNG_EMPTY);
  1567.    /* The 'name' is used for information only */
  1568.  
  1569. /* Routines for checking parts of an ICC profile. */
  1570. PNG_INTERNAL_FUNCTION(int,png_icc_check_length,(png_const_structrp png_ptr,
  1571.    png_colorspacerp colorspace, png_const_charp name,
  1572.    png_uint_32 profile_length), PNG_EMPTY);
  1573. PNG_INTERNAL_FUNCTION(int,png_icc_check_header,(png_const_structrp png_ptr,
  1574.    png_colorspacerp colorspace, png_const_charp name,
  1575.    png_uint_32 profile_length,
  1576.    png_const_bytep profile /* first 132 bytes only */, int color_type),
  1577.    PNG_EMPTY);
  1578. PNG_INTERNAL_FUNCTION(int,png_icc_check_tag_table,(png_const_structrp png_ptr,
  1579.    png_colorspacerp colorspace, png_const_charp name,
  1580.    png_uint_32 profile_length,
  1581.    png_const_bytep profile /* header plus whole tag table */), PNG_EMPTY);
  1582. #ifdef PNG_sRGB_SUPPORTED
  1583. PNG_INTERNAL_FUNCTION(void,png_icc_set_sRGB,(
  1584.    png_const_structrp png_ptr, png_colorspacerp colorspace,
  1585.    png_const_bytep profile, uLong adler), PNG_EMPTY);
  1586.    /* 'adler' is the Adler32 checksum of the uncompressed profile data. It may
  1587.     * be zero to indicate that it is not available.  It is used, if provided,
  1588.     * as a fast check on the profile when checking to see if it is sRGB.
  1589.     */
  1590. #endif
  1591. #endif /* iCCP */
  1592.  
  1593. #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
  1594. PNG_INTERNAL_FUNCTION(void,png_colorspace_set_rgb_coefficients,
  1595.    (png_structrp png_ptr), PNG_EMPTY);
  1596.    /* Set the rgb_to_gray coefficients from the colorspace Y values */
  1597. #endif /* READ_RGB_TO_GRAY */
  1598. #endif /* COLORSPACE */
  1599.  
  1600. /* Added at libpng version 1.4.0 */
  1601. PNG_INTERNAL_FUNCTION(void,png_check_IHDR,(png_const_structrp png_ptr,
  1602.     png_uint_32 width, png_uint_32 height, int bit_depth,
  1603.     int color_type, int interlace_type, int compression_type,
  1604.     int filter_type),PNG_EMPTY);
  1605.  
  1606. /* Added at libpng version 1.5.10 */
  1607. #if defined(PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED) || \
  1608.     defined(PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED)
  1609. PNG_INTERNAL_FUNCTION(void,png_do_check_palette_indexes,
  1610.    (png_structrp png_ptr, png_row_infop row_info),PNG_EMPTY);
  1611. #endif
  1612.  
  1613. #if defined(PNG_FLOATING_POINT_SUPPORTED) && defined(PNG_ERROR_TEXT_SUPPORTED)
  1614. PNG_INTERNAL_FUNCTION(void,png_fixed_error,(png_const_structrp png_ptr,
  1615.    png_const_charp name),PNG_NORETURN);
  1616. #endif
  1617.  
  1618. /* Puts 'string' into 'buffer' at buffer[pos], taking care never to overwrite
  1619.  * the end.  Always leaves the buffer nul terminated.  Never errors out (and
  1620.  * there is no error code.)
  1621.  */
  1622. PNG_INTERNAL_FUNCTION(size_t,png_safecat,(png_charp buffer, size_t bufsize,
  1623.    size_t pos, png_const_charp string),PNG_EMPTY);
  1624.  
  1625. /* Various internal functions to handle formatted warning messages, currently
  1626.  * only implemented for warnings.
  1627.  */
  1628. #if defined(PNG_WARNINGS_SUPPORTED) || defined(PNG_TIME_RFC1123_SUPPORTED)
  1629. /* Utility to dump an unsigned value into a buffer, given a start pointer and
  1630.  * and end pointer (which should point just *beyond* the end of the buffer!)
  1631.  * Returns the pointer to the start of the formatted string.  This utility only
  1632.  * does unsigned values.
  1633.  */
  1634. PNG_INTERNAL_FUNCTION(png_charp,png_format_number,(png_const_charp start,
  1635.    png_charp end, int format, png_alloc_size_t number),PNG_EMPTY);
  1636.  
  1637. /* Convenience macro that takes an array: */
  1638. #define PNG_FORMAT_NUMBER(buffer,format,number) \
  1639.    png_format_number(buffer, buffer + (sizeof buffer), format, number)
  1640.  
  1641. /* Suggested size for a number buffer (enough for 64 bits and a sign!) */
  1642. #define PNG_NUMBER_BUFFER_SIZE 24
  1643.  
  1644. /* These are the integer formats currently supported, the name is formed from
  1645.  * the standard printf(3) format string.
  1646.  */
  1647. #define PNG_NUMBER_FORMAT_u     1 /* chose unsigned API! */
  1648. #define PNG_NUMBER_FORMAT_02u   2
  1649. #define PNG_NUMBER_FORMAT_d     1 /* chose signed API! */
  1650. #define PNG_NUMBER_FORMAT_02d   2
  1651. #define PNG_NUMBER_FORMAT_x     3
  1652. #define PNG_NUMBER_FORMAT_02x   4
  1653. #define PNG_NUMBER_FORMAT_fixed 5 /* choose the signed API */
  1654. #endif
  1655.  
  1656. #ifdef PNG_WARNINGS_SUPPORTED
  1657. /* New defines and members adding in libpng-1.5.4 */
  1658. #  define PNG_WARNING_PARAMETER_SIZE 32
  1659. #  define PNG_WARNING_PARAMETER_COUNT 8 /* Maximum 9; see pngerror.c */
  1660.  
  1661. /* An l-value of this type has to be passed to the APIs below to cache the
  1662.  * values of the parameters to a formatted warning message.
  1663.  */
  1664. typedef char png_warning_parameters[PNG_WARNING_PARAMETER_COUNT][
  1665.    PNG_WARNING_PARAMETER_SIZE];
  1666.  
  1667. PNG_INTERNAL_FUNCTION(void,png_warning_parameter,(png_warning_parameters p,
  1668.    int number, png_const_charp string),PNG_EMPTY);
  1669.    /* Parameters are limited in size to PNG_WARNING_PARAMETER_SIZE characters,
  1670.     * including the trailing '\0'.
  1671.     */
  1672. PNG_INTERNAL_FUNCTION(void,png_warning_parameter_unsigned,
  1673.    (png_warning_parameters p, int number, int format, png_alloc_size_t value),
  1674.    PNG_EMPTY);
  1675.    /* Use png_alloc_size_t because it is an unsigned type as big as any we
  1676.     * need to output.  Use the following for a signed value.
  1677.     */
  1678. PNG_INTERNAL_FUNCTION(void,png_warning_parameter_signed,
  1679.    (png_warning_parameters p, int number, int format, png_int_32 value),
  1680.    PNG_EMPTY);
  1681.  
  1682. PNG_INTERNAL_FUNCTION(void,png_formatted_warning,(png_const_structrp png_ptr,
  1683.    png_warning_parameters p, png_const_charp message),PNG_EMPTY);
  1684.    /* 'message' follows the X/Open approach of using @1, @2 to insert
  1685.     * parameters previously supplied using the above functions.  Errors in
  1686.     * specifying the parameters will simply result in garbage substitutions.
  1687.     */
  1688. #endif
  1689.  
  1690. #ifdef PNG_BENIGN_ERRORS_SUPPORTED
  1691. /* Application errors (new in 1.6); use these functions (declared below) for
  1692.  * errors in the parameters or order of API function calls on read.  The
  1693.  * 'warning' should be used for an error that can be handled completely; the
  1694.  * 'error' for one which can be handled safely but which may lose application
  1695.  * information or settings.
  1696.  *
  1697.  * By default these both result in a png_error call prior to release, while in a
  1698.  * released version the 'warning' is just a warning.  However if the application
  1699.  * explicitly disables benign errors (explicitly permitting the code to lose
  1700.  * information) they both turn into warnings.
  1701.  *
  1702.  * If benign errors aren't supported they end up as the corresponding base call
  1703.  * (png_warning or png_error.)
  1704.  */
  1705. PNG_INTERNAL_FUNCTION(void,png_app_warning,(png_const_structrp png_ptr,
  1706.    png_const_charp message),PNG_EMPTY);
  1707.    /* The application provided invalid parameters to an API function or called
  1708.     * an API function at the wrong time, libpng can completely recover.
  1709.     */
  1710.  
  1711. PNG_INTERNAL_FUNCTION(void,png_app_error,(png_const_structrp png_ptr,
  1712.    png_const_charp message),PNG_EMPTY);
  1713.    /* As above but libpng will ignore the call, or attempt some other partial
  1714.     * recovery from the error.
  1715.     */
  1716. #else
  1717. #  define png_app_warning(pp,s) png_warning(pp,s)
  1718. #  define png_app_error(pp,s) png_error(pp,s)
  1719. #endif
  1720.  
  1721. PNG_INTERNAL_FUNCTION(void,png_chunk_report,(png_const_structrp png_ptr,
  1722.    png_const_charp message, int error),PNG_EMPTY);
  1723.    /* Report a recoverable issue in chunk data.  On read this is used to report
  1724.     * a problem found while reading a particular chunk and the
  1725.     * png_chunk_benign_error or png_chunk_warning function is used as
  1726.     * appropriate.  On write this is used to report an error that comes from
  1727.     * data set via an application call to a png_set_ API and png_app_error or
  1728.     * png_app_warning is used as appropriate.
  1729.     *
  1730.     * The 'error' parameter must have one of the following values:
  1731.     */
  1732. #define PNG_CHUNK_WARNING     0 /* never an error */
  1733. #define PNG_CHUNK_WRITE_ERROR 1 /* an error only on write */
  1734. #define PNG_CHUNK_ERROR       2 /* always an error */
  1735.  
  1736. /* ASCII to FP interfaces, currently only implemented if sCAL
  1737.  * support is required.
  1738.  */
  1739. #if defined(PNG_sCAL_SUPPORTED)
  1740. /* MAX_DIGITS is actually the maximum number of characters in an sCAL
  1741.  * width or height, derived from the precision (number of significant
  1742.  * digits - a build time settable option) and assumptions about the
  1743.  * maximum ridiculous exponent.
  1744.  */
  1745. #define PNG_sCAL_MAX_DIGITS (PNG_sCAL_PRECISION+1/*.*/+1/*E*/+10/*exponent*/)
  1746.  
  1747. #ifdef PNG_FLOATING_POINT_SUPPORTED
  1748. PNG_INTERNAL_FUNCTION(void,png_ascii_from_fp,(png_const_structrp png_ptr,
  1749.    png_charp ascii, png_size_t size, double fp, unsigned int precision),
  1750.    PNG_EMPTY);
  1751. #endif /* FLOATING_POINT */
  1752.  
  1753. #ifdef PNG_FIXED_POINT_SUPPORTED
  1754. PNG_INTERNAL_FUNCTION(void,png_ascii_from_fixed,(png_const_structrp png_ptr,
  1755.    png_charp ascii, png_size_t size, png_fixed_point fp),PNG_EMPTY);
  1756. #endif /* FIXED_POINT */
  1757. #endif /* sCAL */
  1758.  
  1759. #if defined(PNG_sCAL_SUPPORTED) || defined(PNG_pCAL_SUPPORTED)
  1760. /* An internal API to validate the format of a floating point number.
  1761.  * The result is the index of the next character.  If the number is
  1762.  * not valid it will be the index of a character in the supposed number.
  1763.  *
  1764.  * The format of a number is defined in the PNG extensions specification
  1765.  * and this API is strictly conformant to that spec, not anyone elses!
  1766.  *
  1767.  * The format as a regular expression is:
  1768.  *
  1769.  * [+-]?[0-9]+.?([Ee][+-]?[0-9]+)?
  1770.  *
  1771.  * or:
  1772.  *
  1773.  * [+-]?.[0-9]+(.[0-9]+)?([Ee][+-]?[0-9]+)?
  1774.  *
  1775.  * The complexity is that either integer or fraction must be present and the
  1776.  * fraction is permitted to have no digits only if the integer is present.
  1777.  *
  1778.  * NOTE: The dangling E problem.
  1779.  *   There is a PNG valid floating point number in the following:
  1780.  *
  1781.  *       PNG floating point numbers are not greedy.
  1782.  *
  1783.  *   Working this out requires *TWO* character lookahead (because of the
  1784.  *   sign), the parser does not do this - it will fail at the 'r' - this
  1785.  *   doesn't matter for PNG sCAL chunk values, but it requires more care
  1786.  *   if the value were ever to be embedded in something more complex.  Use
  1787.  *   ANSI-C strtod if you need the lookahead.
  1788.  */
  1789. /* State table for the parser. */
  1790. #define PNG_FP_INTEGER    0  /* before or in integer */
  1791. #define PNG_FP_FRACTION   1  /* before or in fraction */
  1792. #define PNG_FP_EXPONENT   2  /* before or in exponent */
  1793. #define PNG_FP_STATE      3  /* mask for the above */
  1794. #define PNG_FP_SAW_SIGN   4  /* Saw +/- in current state */
  1795. #define PNG_FP_SAW_DIGIT  8  /* Saw a digit in current state */
  1796. #define PNG_FP_SAW_DOT   16  /* Saw a dot in current state */
  1797. #define PNG_FP_SAW_E     32  /* Saw an E (or e) in current state */
  1798. #define PNG_FP_SAW_ANY   60  /* Saw any of the above 4 */
  1799.  
  1800. /* These three values don't affect the parser.  They are set but not used.
  1801.  */
  1802. #define PNG_FP_WAS_VALID 64  /* Preceding substring is a valid fp number */
  1803. #define PNG_FP_NEGATIVE 128  /* A negative number, including "-0" */
  1804. #define PNG_FP_NONZERO  256  /* A non-zero value */
  1805. #define PNG_FP_STICKY   448  /* The above three flags */
  1806.  
  1807. /* This is available for the caller to store in 'state' if required.  Do not
  1808.  * call the parser after setting it (the parser sometimes clears it.)
  1809.  */
  1810. #define PNG_FP_INVALID  512  /* Available for callers as a distinct value */
  1811.  
  1812. /* Result codes for the parser (boolean - true meants ok, false means
  1813.  * not ok yet.)
  1814.  */
  1815. #define PNG_FP_MAYBE      0  /* The number may be valid in the future */
  1816. #define PNG_FP_OK         1  /* The number is valid */
  1817.  
  1818. /* Tests on the sticky non-zero and negative flags.  To pass these checks
  1819.  * the state must also indicate that the whole number is valid - this is
  1820.  * achieved by testing PNG_FP_SAW_DIGIT (see the implementation for why this
  1821.  * is equivalent to PNG_FP_OK above.)
  1822.  */
  1823. #define PNG_FP_NZ_MASK (PNG_FP_SAW_DIGIT | PNG_FP_NEGATIVE | PNG_FP_NONZERO)
  1824.    /* NZ_MASK: the string is valid and a non-zero negative value */
  1825. #define PNG_FP_Z_MASK (PNG_FP_SAW_DIGIT | PNG_FP_NONZERO)
  1826.    /* Z MASK: the string is valid and a non-zero value. */
  1827.    /* PNG_FP_SAW_DIGIT: the string is valid. */
  1828. #define PNG_FP_IS_ZERO(state) (((state) & PNG_FP_Z_MASK) == PNG_FP_SAW_DIGIT)
  1829. #define PNG_FP_IS_POSITIVE(state) (((state) & PNG_FP_NZ_MASK) == PNG_FP_Z_MASK)
  1830. #define PNG_FP_IS_NEGATIVE(state) (((state) & PNG_FP_NZ_MASK) == PNG_FP_NZ_MASK)
  1831.  
  1832. /* The actual parser.  This can be called repeatedly. It updates
  1833.  * the index into the string and the state variable (which must
  1834.  * be initialized to 0).  It returns a result code, as above.  There
  1835.  * is no point calling the parser any more if it fails to advance to
  1836.  * the end of the string - it is stuck on an invalid character (or
  1837.  * terminated by '\0').
  1838.  *
  1839.  * Note that the pointer will consume an E or even an E+ and then leave
  1840.  * a 'maybe' state even though a preceding integer.fraction is valid.
  1841.  * The PNG_FP_WAS_VALID flag indicates that a preceding substring was
  1842.  * a valid number.  It's possible to recover from this by calling
  1843.  * the parser again (from the start, with state 0) but with a string
  1844.  * that omits the last character (i.e. set the size to the index of
  1845.  * the problem character.)  This has not been tested within libpng.
  1846.  */
  1847. PNG_INTERNAL_FUNCTION(int,png_check_fp_number,(png_const_charp string,
  1848.    png_size_t size, int *statep, png_size_tp whereami),PNG_EMPTY);
  1849.  
  1850. /* This is the same but it checks a complete string and returns true
  1851.  * only if it just contains a floating point number.  As of 1.5.4 this
  1852.  * function also returns the state at the end of parsing the number if
  1853.  * it was valid (otherwise it returns 0.)  This can be used for testing
  1854.  * for negative or zero values using the sticky flag.
  1855.  */
  1856. PNG_INTERNAL_FUNCTION(int,png_check_fp_string,(png_const_charp string,
  1857.    png_size_t size),PNG_EMPTY);
  1858. #endif /* pCAL || sCAL */
  1859.  
  1860. #if defined(PNG_READ_GAMMA_SUPPORTED) ||\
  1861.     defined(PNG_INCH_CONVERSIONS_SUPPORTED) || defined(PNG_READ_pHYs_SUPPORTED)
  1862. /* Added at libpng version 1.5.0 */
  1863. /* This is a utility to provide a*times/div (rounded) and indicate
  1864.  * if there is an overflow.  The result is a boolean - false (0)
  1865.  * for overflow, true (1) if no overflow, in which case *res
  1866.  * holds the result.
  1867.  */
  1868. PNG_INTERNAL_FUNCTION(int,png_muldiv,(png_fixed_point_p res, png_fixed_point a,
  1869.    png_int_32 multiplied_by, png_int_32 divided_by),PNG_EMPTY);
  1870. #endif
  1871.  
  1872. #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_INCH_CONVERSIONS_SUPPORTED)
  1873. /* Same deal, but issue a warning on overflow and return 0. */
  1874. PNG_INTERNAL_FUNCTION(png_fixed_point,png_muldiv_warn,
  1875.    (png_const_structrp png_ptr, png_fixed_point a, png_int_32 multiplied_by,
  1876.    png_int_32 divided_by),PNG_EMPTY);
  1877. #endif
  1878.  
  1879. #ifdef PNG_GAMMA_SUPPORTED
  1880. /* Calculate a reciprocal - used for gamma values.  This returns
  1881.  * 0 if the argument is 0 in order to maintain an undefined value;
  1882.  * there are no warnings.
  1883.  */
  1884. PNG_INTERNAL_FUNCTION(png_fixed_point,png_reciprocal,(png_fixed_point a),
  1885.    PNG_EMPTY);
  1886.  
  1887. #ifdef PNG_READ_GAMMA_SUPPORTED
  1888. /* The same but gives a reciprocal of the product of two fixed point
  1889.  * values.  Accuracy is suitable for gamma calculations but this is
  1890.  * not exact - use png_muldiv for that.  Only required at present on read.
  1891.  */
  1892. PNG_INTERNAL_FUNCTION(png_fixed_point,png_reciprocal2,(png_fixed_point a,
  1893.    png_fixed_point b),PNG_EMPTY);
  1894. #endif
  1895.  
  1896. /* Return true if the gamma value is significantly different from 1.0 */
  1897. PNG_INTERNAL_FUNCTION(int,png_gamma_significant,(png_fixed_point gamma_value),
  1898.    PNG_EMPTY);
  1899. #endif
  1900.  
  1901. #ifdef PNG_READ_GAMMA_SUPPORTED
  1902. /* Internal fixed point gamma correction.  These APIs are called as
  1903.  * required to convert single values - they don't need to be fast,
  1904.  * they are not used when processing image pixel values.
  1905.  *
  1906.  * While the input is an 'unsigned' value it must actually be the
  1907.  * correct bit value - 0..255 or 0..65535 as required.
  1908.  */
  1909. PNG_INTERNAL_FUNCTION(png_uint_16,png_gamma_correct,(png_structrp png_ptr,
  1910.    unsigned int value, png_fixed_point gamma_value),PNG_EMPTY);
  1911. PNG_INTERNAL_FUNCTION(png_uint_16,png_gamma_16bit_correct,(unsigned int value,
  1912.    png_fixed_point gamma_value),PNG_EMPTY);
  1913. PNG_INTERNAL_FUNCTION(png_byte,png_gamma_8bit_correct,(unsigned int value,
  1914.    png_fixed_point gamma_value),PNG_EMPTY);
  1915. PNG_INTERNAL_FUNCTION(void,png_destroy_gamma_table,(png_structrp png_ptr),
  1916.    PNG_EMPTY);
  1917. PNG_INTERNAL_FUNCTION(void,png_build_gamma_table,(png_structrp png_ptr,
  1918.    int bit_depth),PNG_EMPTY);
  1919. #endif
  1920.  
  1921. /* SIMPLIFIED READ/WRITE SUPPORT */
  1922. #if defined(PNG_SIMPLIFIED_READ_SUPPORTED) ||\
  1923.    defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
  1924. /* The internal structure that png_image::opaque points to. */
  1925. typedef struct png_control
  1926. {
  1927.    png_structp png_ptr;
  1928.    png_infop   info_ptr;
  1929.    png_voidp   error_buf;           /* Always a jmp_buf at present. */
  1930.  
  1931.    png_const_bytep memory;          /* Memory buffer. */
  1932.    png_size_t      size;            /* Size of the memory buffer. */
  1933.  
  1934.    unsigned int for_write       :1; /* Otherwise it is a read structure */
  1935.    unsigned int owned_file      :1; /* We own the file in io_ptr */
  1936. } png_control;
  1937.  
  1938. /* Return the pointer to the jmp_buf from a png_control: necessary because C
  1939.  * does not reveal the type of the elements of jmp_buf.
  1940.  */
  1941. #ifdef __cplusplus
  1942. #  define png_control_jmp_buf(pc) (((jmp_buf*)((pc)->error_buf))[0])
  1943. #else
  1944. #  define png_control_jmp_buf(pc) ((pc)->error_buf)
  1945. #endif
  1946.  
  1947. /* Utility to safely execute a piece of libpng code catching and logging any
  1948.  * errors that might occur.  Returns true on success, false on failure (either
  1949.  * of the function or as a result of a png_error.)
  1950.  */
  1951. PNG_INTERNAL_FUNCTION(void,png_safe_error,(png_structp png_ptr,
  1952.    png_const_charp error_message),PNG_NORETURN);
  1953.  
  1954. #ifdef PNG_WARNINGS_SUPPORTED
  1955. PNG_INTERNAL_FUNCTION(void,png_safe_warning,(png_structp png_ptr,
  1956.    png_const_charp warning_message),PNG_EMPTY);
  1957. #else
  1958. #  define png_safe_warning 0/*dummy argument*/
  1959. #endif
  1960.  
  1961. PNG_INTERNAL_FUNCTION(int,png_safe_execute,(png_imagep image,
  1962.    int (*function)(png_voidp), png_voidp arg),PNG_EMPTY);
  1963.  
  1964. /* Utility to log an error; this also cleans up the png_image; the function
  1965.  * always returns 0 (false).
  1966.  */
  1967. PNG_INTERNAL_FUNCTION(int,png_image_error,(png_imagep image,
  1968.    png_const_charp error_message),PNG_EMPTY);
  1969.  
  1970. #ifndef PNG_SIMPLIFIED_READ_SUPPORTED
  1971. /* png_image_free is used by the write code but not exported */
  1972. PNG_INTERNAL_FUNCTION(void, png_image_free, (png_imagep image), PNG_EMPTY);
  1973. #endif /* !SIMPLIFIED_READ */
  1974.  
  1975. #endif /* SIMPLIFIED READ/WRITE */
  1976.  
  1977. /* These are initialization functions for hardware specific PNG filter
  1978.  * optimizations; list these here then select the appropriate one at compile
  1979.  * time using the macro PNG_FILTER_OPTIMIZATIONS.  If the macro is not defined
  1980.  * the generic code is used.
  1981.  */
  1982. #ifdef PNG_FILTER_OPTIMIZATIONS
  1983. PNG_INTERNAL_FUNCTION(void, PNG_FILTER_OPTIMIZATIONS, (png_structp png_ptr,
  1984.    unsigned int bpp), PNG_EMPTY);
  1985.    /* Just declare the optimization that will be used */
  1986. #else
  1987.    /* List *all* the possible optimizations here - this branch is required if
  1988.     * the builder of libpng passes the definition of PNG_FILTER_OPTIMIZATIONS in
  1989.     * CFLAGS in place of CPPFLAGS *and* uses symbol prefixing.
  1990.     */
  1991. PNG_INTERNAL_FUNCTION(void, png_init_filter_functions_neon,
  1992.    (png_structp png_ptr, unsigned int bpp), PNG_EMPTY);
  1993. #endif
  1994.  
  1995. /* Maintainer: Put new private prototypes here ^ */
  1996.  
  1997. #include "pngdebug.h"
  1998.  
  1999. #ifdef __cplusplus
  2000. }
  2001. #endif
  2002.  
  2003. #endif /* PNG_VERSION_INFO_ONLY */
  2004. #endif /* PNGPRIV_H */
  2005.