Subversion Repositories Kolibri OS

Rev

Blame | Last modification | View Log | RSS feed

  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) 1998-2011 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 1.5.0 [January 6, 2011]
  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 PNG_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. /* This is required for the definition of abort(), used as a last ditch
  29.  * error handler when all else fails.
  30.  */
  31. #include <stdlib.h>
  32.  
  33. #define PNGLIB_BUILD
  34. #ifdef PNG_USER_CONFIG
  35. #  include "pngusr.h"
  36.    /* These should have been defined in pngusr.h */
  37. #  ifndef PNG_USER_PRIVATEBUILD
  38. #    define PNG_USER_PRIVATEBUILD "Custom libpng build"
  39. #  endif
  40. #  ifndef PNG_USER_DLLFNAME_POSTFIX
  41. #    define PNG_USER_DLLFNAME_POSTFIX "Cb"
  42. #  endif
  43. #endif
  44. #include "png.h"
  45. #include "pnginfo.h"
  46. #include "pngstruct.h"
  47.  
  48. /* This is used for 16 bit gamma tables - only the top level pointers are const,
  49.  * this could be changed:
  50.  */
  51. typedef PNG_CONST png_uint_16p FAR * png_const_uint_16pp;
  52.  
  53. /* Added at libpng-1.2.9 */
  54. /* Moved to pngpriv.h at libpng-1.5.0 */
  55.  
  56. /* config.h is created by and PNG_CONFIGURE_LIBPNG is set by the "configure"
  57.  * script.  We may need it here to get the correct configuration on things
  58.  * like limits.
  59.  */
  60. #ifdef PNG_CONFIGURE_LIBPNG
  61. #  ifdef HAVE_CONFIG_H
  62. #    include "config.h"
  63. #  endif
  64. #endif
  65.  
  66. /* Moved to pngpriv.h at libpng-1.5.0 */
  67. /* NOTE: some of these may have been used in external applications as
  68.  * these definitions were exposed in pngconf.h prior to 1.5.
  69.  */
  70.  
  71. /* If you are running on a machine where you cannot allocate more
  72.  * than 64K of memory at once, uncomment this.  While libpng will not
  73.  * normally need that much memory in a chunk (unless you load up a very
  74.  * large file), zlib needs to know how big of a chunk it can use, and
  75.  * libpng thus makes sure to check any memory allocation to verify it
  76.  * will fit into memory.
  77.  *
  78.  * zlib provides 'MAXSEG_64K' which, if defined, indicates the
  79.  * same limit and pngconf.h (already included) sets the limit
  80.  * if certain operating systems are detected.
  81.  */
  82. #if defined(MAXSEG_64K) && !defined(PNG_MAX_MALLOC_64K)
  83. #  define PNG_MAX_MALLOC_64K
  84. #endif
  85.  
  86. /* Unused formal parameter warnings are silenced using the following macro
  87.  * which is expected to have no bad effects on performance (optimizing
  88.  * compilers will probably remove it entirely).  Note that if you replace
  89.  * it with something other than whitespace, you must include the terminating
  90.  * semicolon.
  91.  */
  92. #define PNG_UNUSED(param) (void)param;
  93.  
  94. /* Just a little check that someone hasn't tried to define something
  95.  * contradictory.
  96.  */
  97. #if (PNG_ZBUF_SIZE > 65536L) && defined(PNG_MAX_MALLOC_64K)
  98. #  undef PNG_ZBUF_SIZE
  99. #  define PNG_ZBUF_SIZE 65536L
  100. #endif
  101.  
  102. /* If warnings or errors are turned off the code is disabled
  103.  * or redirected here.
  104.  */
  105. #ifndef PNG_WARNINGS_SUPPORTED
  106. #  define png_warning(s1,s2) ((void)0)
  107. #  define png_chunk_warning(s1,s2) ((void)0)
  108. #endif
  109. #ifndef PNG_ERROR_TEXT_SUPPORTED
  110. #  define png_error(s1,s2) png_err(s1)
  111. #  define png_chunk_error(s1,s2) png_err(s1)
  112. #  define png_fixed_error(s1,s2) png_err(s1)
  113. #endif
  114.  
  115. #ifndef PNG_EXTERN
  116. /* The functions exported by PNG_EXTERN are internal functions, which
  117.  * aren't usually used outside the library (as far as I know), so it is
  118.  * debatable if they should be exported at all.  In the future, when it
  119.  * is possible to have run-time registry of chunk-handling functions,
  120.  * some of these might be made available again.
  121. #  define PNG_EXTERN extern
  122.  */
  123. #  define PNG_EXTERN
  124. #endif
  125.  
  126. /* Some fixed point APIs are still required even if not exported because
  127.  * they get used by the corresponding floating point APIs.  This magic
  128.  * deals with this:
  129.  */
  130. #ifdef PNG_FIXED_POINT_SUPPORTED
  131. #  define PNGFAPI PNGAPI
  132. #else
  133. #  define PNGFAPI /* PRIVATE */
  134. #endif
  135.  
  136. /* Other defines specific to compilers can go here.  Try to keep
  137.  * them inside an appropriate ifdef/endif pair for portability.
  138.  */
  139. #if defined(PNG_FLOATING_POINT_SUPPORTED) ||\
  140.     defined(PNG_FLOATING_ARITHMETIC_SUPPORTED)
  141.    /* png.c requires the following ANSI-C constants if the conversion of
  142.     * floating point to ASCII is implemented therein:
  143.     *
  144.     *  DBL_DIG  Maximum number of decimal digits (can be set to any constant)
  145.     *  DBL_MIN  Smallest normalized fp number (can be set to an arbitrary value)
  146.     *  DBL_MAX  Maximum floating point number (can be set to an arbitrary value)
  147.     */
  148. #  include <float.h>
  149.  
  150. #  if (defined(__MWERKS__) && defined(macintosh)) || defined(applec) || \
  151.     defined(THINK_C) || defined(__SC__) || defined(TARGET_OS_MAC)
  152.      /* We need to check that <math.h> hasn't already been included earlier
  153.       * as it seems it doesn't agree with <fp.h>, yet we should really use
  154.       * <fp.h> if possible.
  155.       */
  156. #    if !defined(__MATH_H__) && !defined(__MATH_H) && !defined(__cmath__)
  157. #      include <fp.h>
  158. #    endif
  159. #  else
  160. #    include <math.h>
  161. #  endif
  162. #  if defined(_AMIGA) && defined(__SASC) && defined(_M68881)
  163.      /* Amiga SAS/C: We must include builtin FPU functions when compiling using
  164.       * MATH=68881
  165.       */
  166. #    include <m68881.h>
  167. #  endif
  168. #endif
  169.  
  170. /* This provides the non-ANSI (far) memory allocation routines. */
  171. #if defined(__TURBOC__) && defined(__MSDOS__)
  172. #  include <mem.h>
  173. #  include <alloc.h>
  174. #endif
  175.  
  176.  
  177. /* Moved here around 1.5.0beta36 from pngconf.h */
  178. /* Users may want to use these so they are not private.  Any library
  179.  * functions that are passed far data must be model-independent.
  180.  */
  181.  
  182. /* Memory model/platform independent fns */
  183. #ifndef PNG_ABORT
  184. #  ifdef _WINDOWS_
  185. #    define PNG_ABORT() ExitProcess(0)
  186. #  else
  187. #    define PNG_ABORT() abort()
  188. #  endif
  189. #endif
  190.  
  191. #ifdef USE_FAR_KEYWORD
  192. /* Use this to make far-to-near assignments */
  193. #  define CHECK   1
  194. #  define NOCHECK 0
  195. #  define CVT_PTR(ptr) (png_far_to_near(png_ptr,ptr,CHECK))
  196. #  define CVT_PTR_NOCHECK(ptr) (png_far_to_near(png_ptr,ptr,NOCHECK))
  197. #  define png_strcpy  _fstrcpy
  198. #  define png_strncpy _fstrncpy   /* Added to v 1.2.6 */
  199. #  define png_strlen  _fstrlen
  200. #  define png_memcmp  _fmemcmp    /* SJT: added */
  201. #  define png_memcpy  _fmemcpy
  202. #  define png_memset  _fmemset
  203. #  define png_sprintf sprintf
  204. #else
  205. #  ifdef _WINDOWS_  /* Favor Windows over C runtime fns */
  206. #    define CVT_PTR(ptr)         (ptr)
  207. #    define CVT_PTR_NOCHECK(ptr) (ptr)
  208. #    define png_strcpy  lstrcpyA
  209. #    define png_strncpy lstrcpynA
  210. #    define png_strlen  lstrlenA
  211. #    define png_memcmp  memcmp
  212. #    define png_memcpy  CopyMemory
  213. #    define png_memset  memset
  214. #    define png_sprintf wsprintfA
  215. #  else
  216. #    define CVT_PTR(ptr)         (ptr)
  217. #    define CVT_PTR_NOCHECK(ptr) (ptr)
  218. #    define png_strcpy  strcpy
  219. #    define png_strncpy strncpy     /* Added to v 1.2.6 */
  220. #    define png_strlen  strlen
  221. #    define png_memcmp  memcmp      /* SJT: added */
  222. #    define png_memcpy  memcpy
  223. #    define png_memset  memset
  224. #    define png_sprintf sprintf
  225. #  endif
  226. #endif
  227. /* End of memory model/platform independent support */
  228.  
  229. #ifndef PNG_NO_SNPRINTF
  230. #  ifdef _MSC_VER
  231. #    define png_snprintf _snprintf   /* Added to v 1.2.19 */
  232. #    define png_snprintf2 _snprintf
  233. #    define png_snprintf6 _snprintf
  234. #  else
  235. #    define png_snprintf snprintf   /* Added to v 1.2.19 */
  236. #    define png_snprintf2 snprintf
  237. #    define png_snprintf6 snprintf
  238. #  endif
  239. #else
  240.   /* You don't have or don't want to use snprintf().  Caution: Using
  241.    * sprintf instead of snprintf exposes your application to accidental
  242.    * or malevolent buffer overflows.  If you don't have snprintf()
  243.    * as a general rule you should provide one (you can get one from
  244.    * Portable OpenSSH).
  245.    */
  246. #  define png_snprintf(s1,n,fmt,x1) png_sprintf(s1,fmt,x1)
  247. #  define png_snprintf2(s1,n,fmt,x1,x2) png_sprintf(s1,fmt,x1,x2)
  248. #  define png_snprintf6(s1,n,fmt,x1,x2,x3,x4,x5,x6) \
  249.       png_sprintf(s1,fmt,x1,x2,x3,x4,x5,x6)
  250. #endif
  251. /* End of 1.5.0beta36 move from pngconf.h */
  252.  
  253. /* CONSTANTS and UTILITY MACROS
  254.  * These are used internally by libpng and not exposed in the API
  255.  */
  256.  
  257. /* Various modes of operation.  Note that after an init, mode is set to
  258.  * zero automatically when the structure is created.
  259.  */
  260. #define PNG_HAVE_IHDR               0x01
  261. #define PNG_HAVE_PLTE               0x02
  262. #define PNG_HAVE_IDAT               0x04
  263. #define PNG_AFTER_IDAT              0x08 /* Have complete zlib datastream */
  264. #define PNG_HAVE_IEND               0x10
  265. #define PNG_HAVE_gAMA               0x20
  266. #define PNG_HAVE_cHRM               0x40
  267. #define PNG_HAVE_sRGB               0x80
  268. #define PNG_HAVE_CHUNK_HEADER      0x100
  269. #define PNG_WROTE_tIME             0x200
  270. #define PNG_WROTE_INFO_BEFORE_PLTE 0x400
  271. #define PNG_BACKGROUND_IS_GRAY     0x800
  272. #define PNG_HAVE_PNG_SIGNATURE    0x1000
  273. #define PNG_HAVE_CHUNK_AFTER_IDAT 0x2000 /* Have another chunk after IDAT */
  274.  
  275. /* Flags for the transformations the PNG library does on the image data */
  276. #define PNG_BGR                 0x0001
  277. #define PNG_INTERLACE           0x0002
  278. #define PNG_PACK                0x0004
  279. #define PNG_SHIFT               0x0008
  280. #define PNG_SWAP_BYTES          0x0010
  281. #define PNG_INVERT_MONO         0x0020
  282. #define PNG_QUANTIZE            0x0040
  283. #define PNG_BACKGROUND          0x0080
  284. #define PNG_BACKGROUND_EXPAND   0x0100
  285.                           /*    0x0200 unused */
  286. #define PNG_16_TO_8             0x0400
  287. #define PNG_RGBA                0x0800
  288. #define PNG_EXPAND              0x1000
  289. #define PNG_GAMMA               0x2000
  290. #define PNG_GRAY_TO_RGB         0x4000
  291. #define PNG_FILLER              0x8000L
  292. #define PNG_PACKSWAP           0x10000L
  293. #define PNG_SWAP_ALPHA         0x20000L
  294. #define PNG_STRIP_ALPHA        0x40000L
  295. #define PNG_INVERT_ALPHA       0x80000L
  296. #define PNG_USER_TRANSFORM    0x100000L
  297. #define PNG_RGB_TO_GRAY_ERR   0x200000L
  298. #define PNG_RGB_TO_GRAY_WARN  0x400000L
  299. #define PNG_RGB_TO_GRAY       0x600000L  /* two bits, RGB_TO_GRAY_ERR|WARN */
  300.                        /*     0x800000L     Unused */
  301. #define PNG_ADD_ALPHA         0x1000000L  /* Added to libpng-1.2.7 */
  302. #define PNG_EXPAND_tRNS       0x2000000L  /* Added to libpng-1.2.9 */
  303.                        /*   0x4000000L  unused */
  304.                        /*   0x8000000L  unused */
  305.                        /*  0x10000000L  unused */
  306.                        /*  0x20000000L  unused */
  307.                        /*  0x40000000L  unused */
  308.  
  309. /* Flags for png_create_struct */
  310. #define PNG_STRUCT_PNG   0x0001
  311. #define PNG_STRUCT_INFO  0x0002
  312.  
  313. /* Scaling factor for filter heuristic weighting calculations */
  314. #define PNG_WEIGHT_FACTOR (1<<(PNG_WEIGHT_SHIFT))
  315. #define PNG_COST_FACTOR (1<<(PNG_COST_SHIFT))
  316.  
  317. /* Flags for the png_ptr->flags rather than declaring a byte for each one */
  318. #define PNG_FLAG_ZLIB_CUSTOM_STRATEGY     0x0001
  319. #define PNG_FLAG_ZLIB_CUSTOM_LEVEL        0x0002
  320. #define PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL    0x0004
  321. #define PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS  0x0008
  322. #define PNG_FLAG_ZLIB_CUSTOM_METHOD       0x0010
  323. #define PNG_FLAG_ZLIB_FINISHED            0x0020
  324. #define PNG_FLAG_ROW_INIT                 0x0040
  325. #define PNG_FLAG_FILLER_AFTER             0x0080
  326. #define PNG_FLAG_CRC_ANCILLARY_USE        0x0100
  327. #define PNG_FLAG_CRC_ANCILLARY_NOWARN     0x0200
  328. #define PNG_FLAG_CRC_CRITICAL_USE         0x0400
  329. #define PNG_FLAG_CRC_CRITICAL_IGNORE      0x0800
  330.                                 /*        0x1000  unused */
  331.                                 /*        0x2000  unused */
  332.                                 /*        0x4000  unused */
  333. #define PNG_FLAG_KEEP_UNKNOWN_CHUNKS      0x8000L
  334. #define PNG_FLAG_KEEP_UNSAFE_CHUNKS       0x10000L
  335. #define PNG_FLAG_LIBRARY_MISMATCH         0x20000L
  336. #define PNG_FLAG_STRIP_ERROR_NUMBERS      0x40000L
  337. #define PNG_FLAG_STRIP_ERROR_TEXT         0x80000L
  338. #define PNG_FLAG_MALLOC_NULL_MEM_OK       0x100000L
  339. #define PNG_FLAG_ADD_ALPHA                0x200000L  /* Added to libpng-1.2.8 */
  340. #define PNG_FLAG_STRIP_ALPHA              0x400000L  /* Added to libpng-1.2.8 */
  341. #define PNG_FLAG_BENIGN_ERRORS_WARN       0x800000L  /* Added to libpng-1.4.0 */
  342.                                   /*     0x1000000L  unused */
  343.                                   /*     0x2000000L  unused */
  344.                                   /*     0x4000000L  unused */
  345.                                   /*     0x8000000L  unused */
  346.                                   /*    0x10000000L  unused */
  347.                                   /*    0x20000000L  unused */
  348.                                   /*    0x40000000L  unused */
  349.  
  350. #define PNG_FLAG_CRC_ANCILLARY_MASK (PNG_FLAG_CRC_ANCILLARY_USE | \
  351.                                      PNG_FLAG_CRC_ANCILLARY_NOWARN)
  352.  
  353. #define PNG_FLAG_CRC_CRITICAL_MASK  (PNG_FLAG_CRC_CRITICAL_USE | \
  354.                                      PNG_FLAG_CRC_CRITICAL_IGNORE)
  355.  
  356. #define PNG_FLAG_CRC_MASK           (PNG_FLAG_CRC_ANCILLARY_MASK | \
  357.                                      PNG_FLAG_CRC_CRITICAL_MASK)
  358.  
  359. /* zlib.h declares a magic type 'uInt' that limits the amount of data that zlib
  360.  * can handle at once.  This type need be no larger than 16 bits (so maximum of
  361.  * 65535), this define allows us to discover how big it is, but limited by the
  362.  * maximuum for png_size_t.  The value can be overriden in a library build
  363.  * (pngusr.h, or set it in CPPFLAGS) and it works to set it to a considerably
  364.  * lower value (e.g. 255 works).  A lower value may help memory usage (slightly)
  365.  * and may even improve performance on some systems (and degrade it on others.)
  366.  */
  367. #ifndef ZLIB_IO_MAX
  368. #  define ZLIB_IO_MAX ((uInt)-1)
  369. #endif
  370.  
  371. /* Save typing and make code easier to understand */
  372.  
  373. #define PNG_COLOR_DIST(c1, c2) (abs((int)((c1).red) - (int)((c2).red)) + \
  374.    abs((int)((c1).green) - (int)((c2).green)) + \
  375.    abs((int)((c1).blue) - (int)((c2).blue)))
  376.  
  377. /* Added to libpng-1.2.6 JB */
  378. #define PNG_ROWBYTES(pixel_bits, width) \
  379.     ((pixel_bits) >= 8 ? \
  380.     ((png_size_t)(width) * (((png_size_t)(pixel_bits)) >> 3)) : \
  381.     (( ((png_size_t)(width) * ((png_size_t)(pixel_bits))) + 7) >> 3) )
  382.  
  383. /* PNG_OUT_OF_RANGE returns true if value is outside the range
  384.  * ideal-delta..ideal+delta.  Each argument is evaluated twice.
  385.  * "ideal" and "delta" should be constants, normally simple
  386.  * integers, "value" a variable. Added to libpng-1.2.6 JB
  387.  */
  388. #define PNG_OUT_OF_RANGE(value, ideal, delta) \
  389.    ( (value) < (ideal)-(delta) || (value) > (ideal)+(delta) )
  390.  
  391. /* Conversions between fixed and floating point, only defined if
  392.  * required (to make sure the code doesn't accidentally use float
  393.  * when it is supposedly disabled.)
  394.  */
  395. #ifdef PNG_FLOATING_POINT_SUPPORTED
  396. /* The floating point conversion can't overflow, though it can and
  397.  * does lose accuracy relative to the original fixed point value.
  398.  * In practice this doesn't matter because png_fixed_point only
  399.  * stores numbers with very low precision.  The png_ptr and s
  400.  * arguments are unused by default but are there in case error
  401.  * checking becomes a requirement.
  402.  */
  403. #define png_float(png_ptr, fixed, s) (.00001 * (fixed))
  404.  
  405. /* The fixed point conversion performs range checking and evaluates
  406.  * its argument multiple times, so must be used with care.  The
  407.  * range checking uses the PNG specification values for a signed
  408.  * 32 bit fixed point value except that the values are deliberately
  409.  * rounded-to-zero to an integral value - 21474 (21474.83 is roughly
  410.  * (2^31-1) * 100000). 's' is a string that describes the value being
  411.  * converted.
  412.  *
  413.  * NOTE: this macro will raise a png_error if the range check fails,
  414.  * therefore it is normally only appropriate to use this on values
  415.  * that come from API calls or other sources where an out of range
  416.  * error indicates a programming error, not a data error!
  417.  *
  418.  * NOTE: by default this is off - the macro is not used - because the
  419.  * function call saves a lot of code.
  420.  */
  421. #ifdef PNG_FIXED_POINT_MACRO_SUPPORTED
  422. #define png_fixed(png_ptr, fp, s) ((fp) <= 21474 && (fp) >= -21474 ?\
  423.     ((png_fixed_point)(100000 * (fp))) : (png_fixed_error(png_ptr, s),0))
  424. #else
  425. PNG_EXTERN png_fixed_point png_fixed PNGARG((png_structp png_ptr, double fp,
  426.    png_const_charp text));
  427. #endif
  428. #endif
  429.  
  430. /* Constant strings for known chunk types.  If you need to add a chunk,
  431.  * define the name here, and add an invocation of the macro wherever it's
  432.  * needed.
  433.  */
  434. #define PNG_IHDR PNG_CONST png_byte png_IHDR[5] = { 73,  72,  68,  82, '\0'}
  435. #define PNG_IDAT PNG_CONST png_byte png_IDAT[5] = { 73,  68,  65,  84, '\0'}
  436. #define PNG_IEND PNG_CONST png_byte png_IEND[5] = { 73,  69,  78,  68, '\0'}
  437. #define PNG_PLTE PNG_CONST png_byte png_PLTE[5] = { 80,  76,  84,  69, '\0'}
  438. #define PNG_bKGD PNG_CONST png_byte png_bKGD[5] = { 98,  75,  71,  68, '\0'}
  439. #define PNG_cHRM PNG_CONST png_byte png_cHRM[5] = { 99,  72,  82,  77, '\0'}
  440. #define PNG_gAMA PNG_CONST png_byte png_gAMA[5] = {103,  65,  77,  65, '\0'}
  441. #define PNG_hIST PNG_CONST png_byte png_hIST[5] = {104,  73,  83,  84, '\0'}
  442. #define PNG_iCCP PNG_CONST png_byte png_iCCP[5] = {105,  67,  67,  80, '\0'}
  443. #define PNG_iTXt PNG_CONST png_byte png_iTXt[5] = {105,  84,  88, 116, '\0'}
  444. #define PNG_oFFs PNG_CONST png_byte png_oFFs[5] = {111,  70,  70, 115, '\0'}
  445. #define PNG_pCAL PNG_CONST png_byte png_pCAL[5] = {112,  67,  65,  76, '\0'}
  446. #define PNG_sCAL PNG_CONST png_byte png_sCAL[5] = {115,  67,  65,  76, '\0'}
  447. #define PNG_pHYs PNG_CONST png_byte png_pHYs[5] = {112,  72,  89, 115, '\0'}
  448. #define PNG_sBIT PNG_CONST png_byte png_sBIT[5] = {115,  66,  73,  84, '\0'}
  449. #define PNG_sPLT PNG_CONST png_byte png_sPLT[5] = {115,  80,  76,  84, '\0'}
  450. #define PNG_sRGB PNG_CONST png_byte png_sRGB[5] = {115,  82,  71,  66, '\0'}
  451. #define PNG_sTER PNG_CONST png_byte png_sTER[5] = {115,  84,  69,  82, '\0'}
  452. #define PNG_tEXt PNG_CONST png_byte png_tEXt[5] = {116,  69,  88, 116, '\0'}
  453. #define PNG_tIME PNG_CONST png_byte png_tIME[5] = {116,  73,  77,  69, '\0'}
  454. #define PNG_tRNS PNG_CONST png_byte png_tRNS[5] = {116,  82,  78,  83, '\0'}
  455. #define PNG_zTXt PNG_CONST png_byte png_zTXt[5] = {122,  84,  88, 116, '\0'}
  456.  
  457.  
  458. /* Inhibit C++ name-mangling for libpng functions but not for system calls. */
  459. #ifdef __cplusplus
  460. extern "C" {
  461. #endif /* __cplusplus */
  462.  
  463. /* These functions are used internally in the code.  They generally
  464.  * shouldn't be used unless you are writing code to add or replace some
  465.  * functionality in libpng.  More information about most functions can
  466.  * be found in the files where the functions are located.
  467.  */
  468.  
  469. /* Allocate memory for an internal libpng struct */
  470. PNG_EXTERN PNG_FUNCTION(png_voidp,png_create_struct,PNGARG((int type)),
  471.    PNG_ALLOCATED);
  472.  
  473. /* Free memory from internal libpng struct */
  474. PNG_EXTERN void png_destroy_struct PNGARG((png_voidp struct_ptr));
  475.  
  476. PNG_EXTERN PNG_FUNCTION(png_voidp,png_create_struct_2,
  477.    PNGARG((int type, png_malloc_ptr malloc_fn, png_voidp mem_ptr)),
  478.    PNG_ALLOCATED);
  479. PNG_EXTERN void png_destroy_struct_2 PNGARG((png_voidp struct_ptr,
  480.     png_free_ptr free_fn, png_voidp mem_ptr));
  481.  
  482. /* Free any memory that info_ptr points to and reset struct. */
  483. PNG_EXTERN void png_info_destroy PNGARG((png_structp png_ptr,
  484.     png_infop info_ptr));
  485.  
  486. /* Function to allocate memory for zlib.  PNGAPI is disallowed. */
  487. PNG_EXTERN PNG_FUNCTION(voidpf,png_zalloc,PNGARG((voidpf png_ptr, uInt items,
  488.    uInt size)),PNG_ALLOCATED);
  489.  
  490. /* Function to free memory for zlib.  PNGAPI is disallowed. */
  491. PNG_EXTERN void png_zfree PNGARG((voidpf png_ptr, voidpf ptr));
  492.  
  493. /* Next four functions are used internally as callbacks.  PNGCBAPI is required
  494.  * but not PNG_EXPORT.  PNGAPI added at libpng version 1.2.3, changed to
  495.  * PNGCBAPI at 1.5.0
  496.  */
  497.  
  498. PNG_EXTERN void PNGCBAPI png_default_read_data PNGARG((png_structp png_ptr,
  499.     png_bytep data, png_size_t length));
  500.  
  501. #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
  502. PNG_EXTERN void PNGCBAPI png_push_fill_buffer PNGARG((png_structp png_ptr,
  503.     png_bytep buffer, png_size_t length));
  504. #endif
  505.  
  506. PNG_EXTERN void PNGCBAPI png_default_write_data PNGARG((png_structp png_ptr,
  507.     png_bytep data, png_size_t length));
  508.  
  509. #ifdef PNG_WRITE_FLUSH_SUPPORTED
  510. #  ifdef PNG_STDIO_SUPPORTED
  511. PNG_EXTERN void PNGCBAPI png_default_flush PNGARG((png_structp png_ptr));
  512. #  endif
  513. #endif
  514.  
  515. /* Reset the CRC variable */
  516. PNG_EXTERN void png_reset_crc PNGARG((png_structp png_ptr));
  517.  
  518. /* Write the "data" buffer to whatever output you are using */
  519. PNG_EXTERN void png_write_data PNGARG((png_structp png_ptr,
  520.     png_const_bytep data, png_size_t length));
  521.  
  522. /* Read and check the PNG file signature */
  523. PNG_EXTERN void png_read_sig PNGARG((png_structp png_ptr, png_infop info_ptr));
  524.  
  525. /* Read the chunk header (length + type name) */
  526. PNG_EXTERN png_uint_32 png_read_chunk_header PNGARG((png_structp png_ptr));
  527.  
  528. /* Read data from whatever input you are using into the "data" buffer */
  529. PNG_EXTERN void png_read_data PNGARG((png_structp png_ptr, png_bytep data,
  530.     png_size_t length));
  531.  
  532. /* Read bytes into buf, and update png_ptr->crc */
  533. PNG_EXTERN void png_crc_read PNGARG((png_structp png_ptr, png_bytep buf,
  534.     png_size_t length));
  535.  
  536. /* Decompress data in a chunk that uses compression */
  537. #if defined(PNG_zTXt_SUPPORTED) || defined(PNG_iTXt_SUPPORTED) || \
  538.     defined(PNG_iCCP_SUPPORTED) || defined(PNG_sPLT_SUPPORTED)
  539. PNG_EXTERN void png_decompress_chunk PNGARG((png_structp png_ptr,
  540.     int comp_type, png_size_t chunklength, png_size_t prefix_length,
  541.     png_size_t *data_length));
  542. #endif
  543.  
  544. /* Read "skip" bytes, read the file crc, and (optionally) verify png_ptr->crc */
  545. PNG_EXTERN int png_crc_finish PNGARG((png_structp png_ptr, png_uint_32 skip));
  546.  
  547. /* Read the CRC from the file and compare it to the libpng calculated CRC */
  548. PNG_EXTERN int png_crc_error PNGARG((png_structp png_ptr));
  549.  
  550. /* Calculate the CRC over a section of data.  Note that we are only
  551.  * passing a maximum of 64K on systems that have this as a memory limit,
  552.  * since this is the maximum buffer size we can specify.
  553.  */
  554. PNG_EXTERN void png_calculate_crc PNGARG((png_structp png_ptr,
  555.     png_const_bytep ptr, png_size_t length));
  556.  
  557. #ifdef PNG_WRITE_FLUSH_SUPPORTED
  558. PNG_EXTERN void png_flush PNGARG((png_structp png_ptr));
  559. #endif
  560.  
  561. /* Write various chunks */
  562.  
  563. /* Write the IHDR chunk, and update the png_struct with the necessary
  564.  * information.
  565.  */
  566. PNG_EXTERN void png_write_IHDR PNGARG((png_structp png_ptr, png_uint_32 width,
  567.     png_uint_32 height,
  568.     int bit_depth, int color_type, int compression_method, int filter_method,
  569.     int interlace_method));
  570.  
  571. PNG_EXTERN void png_write_PLTE PNGARG((png_structp png_ptr,
  572.     png_const_colorp palette, png_uint_32 num_pal));
  573.  
  574. PNG_EXTERN void png_write_IDAT PNGARG((png_structp png_ptr, png_bytep data,
  575.     png_size_t length));
  576.  
  577. PNG_EXTERN void png_write_IEND PNGARG((png_structp png_ptr));
  578.  
  579. #ifdef PNG_WRITE_gAMA_SUPPORTED
  580. #  ifdef PNG_FLOATING_POINT_SUPPORTED
  581. PNG_EXTERN void png_write_gAMA PNGARG((png_structp png_ptr, double file_gamma));
  582. #  endif
  583. #  ifdef PNG_FIXED_POINT_SUPPORTED
  584. PNG_EXTERN void png_write_gAMA_fixed PNGARG((png_structp png_ptr,
  585.     png_fixed_point file_gamma));
  586. #  endif
  587. #endif
  588.  
  589. #ifdef PNG_WRITE_sBIT_SUPPORTED
  590. PNG_EXTERN void png_write_sBIT PNGARG((png_structp png_ptr,
  591.     png_const_color_8p sbit, int color_type));
  592. #endif
  593.  
  594. #ifdef PNG_WRITE_cHRM_SUPPORTED
  595. #  ifdef PNG_FLOATING_POINT_SUPPORTED
  596. PNG_EXTERN void png_write_cHRM PNGARG((png_structp png_ptr,
  597.     double white_x, double white_y,
  598.     double red_x, double red_y, double green_x, double green_y,
  599.     double blue_x, double blue_y));
  600. #  endif
  601. PNG_EXTERN void png_write_cHRM_fixed PNGARG((png_structp png_ptr,
  602.     png_fixed_point int_white_x, png_fixed_point int_white_y,
  603.     png_fixed_point int_red_x, png_fixed_point int_red_y, png_fixed_point
  604.     int_green_x, png_fixed_point int_green_y, png_fixed_point int_blue_x,
  605.     png_fixed_point int_blue_y));
  606. #endif
  607.  
  608. #ifdef PNG_WRITE_sRGB_SUPPORTED
  609. PNG_EXTERN void png_write_sRGB PNGARG((png_structp png_ptr,
  610.     int intent));
  611. #endif
  612.  
  613. #ifdef PNG_WRITE_iCCP_SUPPORTED
  614. PNG_EXTERN void png_write_iCCP PNGARG((png_structp png_ptr,
  615.     png_const_charp name, int compression_type,
  616.     png_const_charp profile, int proflen));
  617.    /* Note to maintainer: profile should be png_bytep */
  618. #endif
  619.  
  620. #ifdef PNG_WRITE_sPLT_SUPPORTED
  621. PNG_EXTERN void png_write_sPLT PNGARG((png_structp png_ptr,
  622.     png_const_sPLT_tp palette));
  623. #endif
  624.  
  625. #ifdef PNG_WRITE_tRNS_SUPPORTED
  626. PNG_EXTERN void png_write_tRNS PNGARG((png_structp png_ptr,
  627.     png_const_bytep trans, png_const_color_16p values, int number,
  628.     int color_type));
  629. #endif
  630.  
  631. #ifdef PNG_WRITE_bKGD_SUPPORTED
  632. PNG_EXTERN void png_write_bKGD PNGARG((png_structp png_ptr,
  633.     png_const_color_16p values, int color_type));
  634. #endif
  635.  
  636. #ifdef PNG_WRITE_hIST_SUPPORTED
  637. PNG_EXTERN void png_write_hIST PNGARG((png_structp png_ptr,
  638.     png_const_uint_16p hist, int num_hist));
  639. #endif
  640.  
  641. #if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_pCAL_SUPPORTED) || \
  642.     defined(PNG_WRITE_iCCP_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED)
  643. PNG_EXTERN png_size_t png_check_keyword PNGARG((png_structp png_ptr,
  644.     png_const_charp key, png_charpp new_key));
  645. #endif
  646.  
  647. #ifdef PNG_WRITE_tEXt_SUPPORTED
  648. PNG_EXTERN void png_write_tEXt PNGARG((png_structp png_ptr, png_const_charp key,
  649.     png_const_charp text, png_size_t text_len));
  650. #endif
  651.  
  652. #ifdef PNG_WRITE_zTXt_SUPPORTED
  653. PNG_EXTERN void png_write_zTXt PNGARG((png_structp png_ptr, png_const_charp key,
  654.     png_const_charp text, png_size_t text_len, int compression));
  655. #endif
  656.  
  657. #ifdef PNG_WRITE_iTXt_SUPPORTED
  658. PNG_EXTERN void png_write_iTXt PNGARG((png_structp png_ptr,
  659.     int compression, png_const_charp key, png_const_charp lang,
  660.     png_const_charp lang_key, png_const_charp text));
  661. #endif
  662.  
  663. #ifdef PNG_TEXT_SUPPORTED  /* Added at version 1.0.14 and 1.2.4 */
  664. PNG_EXTERN int png_set_text_2 PNGARG((png_structp png_ptr,
  665.     png_infop info_ptr, png_const_textp text_ptr, int num_text));
  666. #endif
  667.  
  668. #ifdef PNG_WRITE_oFFs_SUPPORTED
  669. PNG_EXTERN void png_write_oFFs PNGARG((png_structp png_ptr,
  670.     png_int_32 x_offset, png_int_32 y_offset, int unit_type));
  671. #endif
  672.  
  673. #ifdef PNG_WRITE_pCAL_SUPPORTED
  674. PNG_EXTERN void png_write_pCAL PNGARG((png_structp png_ptr, png_charp purpose,
  675.     png_int_32 X0, png_int_32 X1, int type, int nparams,
  676.     png_const_charp units, png_charpp params));
  677. #endif
  678.  
  679. #ifdef PNG_WRITE_pHYs_SUPPORTED
  680. PNG_EXTERN void png_write_pHYs PNGARG((png_structp png_ptr,
  681.     png_uint_32 x_pixels_per_unit, png_uint_32 y_pixels_per_unit,
  682.     int unit_type));
  683. #endif
  684.  
  685. #ifdef PNG_WRITE_tIME_SUPPORTED
  686. PNG_EXTERN void png_write_tIME PNGARG((png_structp png_ptr,
  687.     png_const_timep mod_time));
  688. #endif
  689.  
  690. #ifdef PNG_WRITE_sCAL_SUPPORTED
  691. PNG_EXTERN void png_write_sCAL_s PNGARG((png_structp png_ptr,
  692.     int unit, png_const_charp width, png_const_charp height));
  693. #endif
  694.  
  695. /* Called when finished processing a row of data */
  696. PNG_EXTERN void png_write_finish_row PNGARG((png_structp png_ptr));
  697.  
  698. /* Internal use only.   Called before first row of data */
  699. PNG_EXTERN void png_write_start_row PNGARG((png_structp png_ptr));
  700.  
  701. /* Combine a row of data, dealing with alpha, etc. if requested */
  702. PNG_EXTERN void png_combine_row PNGARG((png_structp png_ptr, png_bytep row,
  703.     int mask));
  704.  
  705. #ifdef PNG_READ_INTERLACING_SUPPORTED
  706. /* Expand an interlaced row */
  707. /* OLD pre-1.0.9 interface:
  708. PNG_EXTERN void png_do_read_interlace PNGARG((png_row_infop row_info,
  709.     png_bytep row, int pass, png_uint_32 transformations));
  710.  */
  711. PNG_EXTERN void png_do_read_interlace PNGARG((png_structp png_ptr));
  712. #endif
  713.  
  714. /* GRR TO DO (2.0 or whenever):  simplify other internal calling interfaces */
  715.  
  716. #ifdef PNG_WRITE_INTERLACING_SUPPORTED
  717. /* Grab pixels out of a row for an interlaced pass */
  718. PNG_EXTERN void png_do_write_interlace PNGARG((png_row_infop row_info,
  719.     png_bytep row, int pass));
  720. #endif
  721.  
  722. /* Unfilter a row */
  723. PNG_EXTERN void png_read_filter_row PNGARG((png_structp png_ptr,
  724.     png_row_infop row_info, png_bytep row, png_const_bytep prev_row,
  725.     int filter));
  726.  
  727. /* Choose the best filter to use and filter the row data */
  728. PNG_EXTERN void png_write_find_filter PNGARG((png_structp png_ptr,
  729.     png_row_infop row_info));
  730.  
  731. /* Write out the filtered row. */
  732. PNG_EXTERN void png_write_filtered_row PNGARG((png_structp png_ptr,
  733.     png_bytep filtered_row));
  734. /* Finish a row while reading, dealing with interlacing passes, etc. */
  735. PNG_EXTERN void png_read_finish_row PNGARG((png_structp png_ptr));
  736.  
  737. /* Initialize the row buffers, etc. */
  738. PNG_EXTERN void png_read_start_row PNGARG((png_structp png_ptr));
  739. /* Optional call to update the users info structure */
  740. PNG_EXTERN void png_read_transform_info PNGARG((png_structp png_ptr,
  741.     png_infop info_ptr));
  742.  
  743. /* These are the functions that do the transformations */
  744. #ifdef PNG_READ_FILLER_SUPPORTED
  745. PNG_EXTERN void png_do_read_filler PNGARG((png_row_infop row_info,
  746.     png_bytep row, png_uint_32 filler, png_uint_32 flags));
  747. #endif
  748.  
  749. #ifdef PNG_READ_SWAP_ALPHA_SUPPORTED
  750. PNG_EXTERN void png_do_read_swap_alpha PNGARG((png_row_infop row_info,
  751.     png_bytep row));
  752. #endif
  753.  
  754. #ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED
  755. PNG_EXTERN void png_do_write_swap_alpha PNGARG((png_row_infop row_info,
  756.     png_bytep row));
  757. #endif
  758.  
  759. #ifdef PNG_READ_INVERT_ALPHA_SUPPORTED
  760. PNG_EXTERN void png_do_read_invert_alpha PNGARG((png_row_infop row_info,
  761.     png_bytep row));
  762. #endif
  763.  
  764. #ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
  765. PNG_EXTERN void png_do_write_invert_alpha PNGARG((png_row_infop row_info,
  766.     png_bytep row));
  767. #endif
  768.  
  769. #if defined(PNG_WRITE_FILLER_SUPPORTED) || \
  770.     defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
  771. PNG_EXTERN void png_do_strip_filler PNGARG((png_row_infop row_info,
  772.     png_bytep row, png_uint_32 flags));
  773. #endif
  774.  
  775. #ifdef PNG_16BIT_SUPPORTED
  776. #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
  777. PNG_EXTERN void png_do_swap PNGARG((png_row_infop row_info,
  778.     png_bytep row));
  779. #endif
  780. #endif
  781.  
  782. #if defined(PNG_READ_PACKSWAP_SUPPORTED) || \
  783.     defined(PNG_WRITE_PACKSWAP_SUPPORTED)
  784. PNG_EXTERN void png_do_packswap PNGARG((png_row_infop row_info,
  785.     png_bytep row));
  786. #endif
  787.  
  788. #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
  789. PNG_EXTERN int png_do_rgb_to_gray PNGARG((png_structp png_ptr,
  790.     png_row_infop row_info, png_bytep row));
  791. #endif
  792.  
  793. #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
  794. PNG_EXTERN void png_do_gray_to_rgb PNGARG((png_row_infop row_info,
  795.     png_bytep row));
  796. #endif
  797.  
  798. #ifdef PNG_READ_PACK_SUPPORTED
  799. PNG_EXTERN void png_do_unpack PNGARG((png_row_infop row_info,
  800.     png_bytep row));
  801. #endif
  802.  
  803. #ifdef PNG_READ_SHIFT_SUPPORTED
  804. PNG_EXTERN void png_do_unshift PNGARG((png_row_infop row_info,
  805.     png_bytep row, png_const_color_8p sig_bits));
  806. #endif
  807.  
  808. #if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
  809. PNG_EXTERN void png_do_invert PNGARG((png_row_infop row_info,
  810.     png_bytep row));
  811. #endif
  812.  
  813. #ifdef PNG_READ_16_TO_8_SUPPORTED
  814. PNG_EXTERN void png_do_chop PNGARG((png_row_infop row_info,
  815.     png_bytep row));
  816. #endif
  817.  
  818. #ifdef PNG_READ_QUANTIZE_SUPPORTED
  819. PNG_EXTERN void png_do_quantize PNGARG((png_row_infop row_info,
  820.     png_bytep row, png_const_bytep palette_lookup,
  821.     png_const_bytep quantize_lookup));
  822.  
  823. #  ifdef PNG_CORRECT_PALETTE_SUPPORTED
  824. PNG_EXTERN void png_correct_palette PNGARG((png_structp png_ptr,
  825.     png_colorp palette, int num_palette));
  826. #  endif
  827. #endif
  828.  
  829. #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
  830. PNG_EXTERN void png_do_bgr PNGARG((png_row_infop row_info,
  831.     png_bytep row));
  832. #endif
  833.  
  834. #ifdef PNG_WRITE_PACK_SUPPORTED
  835. PNG_EXTERN void png_do_pack PNGARG((png_row_infop row_info,
  836.    png_bytep row, png_uint_32 bit_depth));
  837. #endif
  838.  
  839. #ifdef PNG_WRITE_SHIFT_SUPPORTED
  840. PNG_EXTERN void png_do_shift PNGARG((png_row_infop row_info,
  841.     png_bytep row, png_const_color_8p bit_depth));
  842. #endif
  843.  
  844. #ifdef PNG_READ_BACKGROUND_SUPPORTED
  845. #  ifdef PNG_READ_GAMMA_SUPPORTED
  846. PNG_EXTERN void png_do_background PNGARG((png_row_infop row_info,
  847.     png_bytep row, png_const_color_16p trans_color,
  848.     png_const_color_16p background, png_const_color_16p background_1,
  849.     png_const_bytep gamma_table, png_const_bytep gamma_from_1,
  850.     png_const_bytep gamma_to_1, png_const_uint_16pp gamma_16,
  851.     png_const_uint_16pp gamma_16_from_1, png_const_uint_16pp gamma_16_to_1,
  852.     int gamma_shift));
  853. #  else
  854. PNG_EXTERN void png_do_background PNGARG((png_row_infop row_info,
  855.     png_bytep row, png_const_color_16p trans_color,
  856.     png_const_color_16p background));
  857. #  endif
  858. #endif
  859.  
  860. #ifdef PNG_READ_GAMMA_SUPPORTED
  861. PNG_EXTERN void png_do_gamma PNGARG((png_row_infop row_info,
  862.     png_bytep row, png_const_bytep gamma_table,
  863.     png_const_uint_16pp gamma_16_table, int gamma_shift));
  864. #endif
  865.  
  866. #ifdef PNG_READ_EXPAND_SUPPORTED
  867. PNG_EXTERN void png_do_expand_palette PNGARG((png_row_infop row_info,
  868.     png_bytep row, png_const_colorp palette, png_const_bytep trans,
  869.     int num_trans));
  870. PNG_EXTERN void png_do_expand PNGARG((png_row_infop row_info,
  871.     png_bytep row, png_const_color_16p trans_color));
  872. #endif
  873.  
  874. /* The following decodes the appropriate chunks, and does error correction,
  875.  * then calls the appropriate callback for the chunk if it is valid.
  876.  */
  877.  
  878. /* Decode the IHDR chunk */
  879. PNG_EXTERN void png_handle_IHDR PNGARG((png_structp png_ptr, png_infop info_ptr,
  880.     png_uint_32 length));
  881. PNG_EXTERN void png_handle_PLTE PNGARG((png_structp png_ptr, png_infop info_ptr,
  882.     png_uint_32 length));
  883. PNG_EXTERN void png_handle_IEND PNGARG((png_structp png_ptr, png_infop info_ptr,
  884.     png_uint_32 length));
  885.  
  886. #ifdef PNG_READ_bKGD_SUPPORTED
  887. PNG_EXTERN void png_handle_bKGD PNGARG((png_structp png_ptr, png_infop info_ptr,
  888.     png_uint_32 length));
  889. #endif
  890.  
  891. #ifdef PNG_READ_cHRM_SUPPORTED
  892. PNG_EXTERN void png_handle_cHRM PNGARG((png_structp png_ptr, png_infop info_ptr,
  893.     png_uint_32 length));
  894. #endif
  895.  
  896. #ifdef PNG_READ_gAMA_SUPPORTED
  897. PNG_EXTERN void png_handle_gAMA PNGARG((png_structp png_ptr, png_infop info_ptr,
  898.     png_uint_32 length));
  899. #endif
  900.  
  901. #ifdef PNG_READ_hIST_SUPPORTED
  902. PNG_EXTERN void png_handle_hIST PNGARG((png_structp png_ptr, png_infop info_ptr,
  903.     png_uint_32 length));
  904. #endif
  905.  
  906. #ifdef PNG_READ_iCCP_SUPPORTED
  907. PNG_EXTERN void png_handle_iCCP PNGARG((png_structp png_ptr, png_infop info_ptr,
  908.     png_uint_32 length));
  909. #endif /* PNG_READ_iCCP_SUPPORTED */
  910.  
  911. #ifdef PNG_READ_iTXt_SUPPORTED
  912. PNG_EXTERN void png_handle_iTXt PNGARG((png_structp png_ptr, png_infop info_ptr,
  913.     png_uint_32 length));
  914. #endif
  915.  
  916. #ifdef PNG_READ_oFFs_SUPPORTED
  917. PNG_EXTERN void png_handle_oFFs PNGARG((png_structp png_ptr, png_infop info_ptr,
  918.     png_uint_32 length));
  919. #endif
  920.  
  921. #ifdef PNG_READ_pCAL_SUPPORTED
  922. PNG_EXTERN void png_handle_pCAL PNGARG((png_structp png_ptr, png_infop info_ptr,
  923.     png_uint_32 length));
  924. #endif
  925.  
  926. #ifdef PNG_READ_pHYs_SUPPORTED
  927. PNG_EXTERN void png_handle_pHYs PNGARG((png_structp png_ptr, png_infop info_ptr,
  928.     png_uint_32 length));
  929. #endif
  930.  
  931. #ifdef PNG_READ_sBIT_SUPPORTED
  932. PNG_EXTERN void png_handle_sBIT PNGARG((png_structp png_ptr, png_infop info_ptr,
  933.     png_uint_32 length));
  934. #endif
  935.  
  936. #ifdef PNG_READ_sCAL_SUPPORTED
  937. PNG_EXTERN void png_handle_sCAL PNGARG((png_structp png_ptr, png_infop info_ptr,
  938.     png_uint_32 length));
  939. #endif
  940.  
  941. #ifdef PNG_READ_sPLT_SUPPORTED
  942. PNG_EXTERN void png_handle_sPLT PNGARG((png_structp png_ptr, png_infop info_ptr,
  943.     png_uint_32 length));
  944. #endif /* PNG_READ_sPLT_SUPPORTED */
  945.  
  946. #ifdef PNG_READ_sRGB_SUPPORTED
  947. PNG_EXTERN void png_handle_sRGB PNGARG((png_structp png_ptr, png_infop info_ptr,
  948.     png_uint_32 length));
  949. #endif
  950.  
  951. #ifdef PNG_READ_tEXt_SUPPORTED
  952. PNG_EXTERN void png_handle_tEXt PNGARG((png_structp png_ptr, png_infop info_ptr,
  953.     png_uint_32 length));
  954. #endif
  955.  
  956. #ifdef PNG_READ_tIME_SUPPORTED
  957. PNG_EXTERN void png_handle_tIME PNGARG((png_structp png_ptr, png_infop info_ptr,
  958.     png_uint_32 length));
  959. #endif
  960.  
  961. #ifdef PNG_READ_tRNS_SUPPORTED
  962. PNG_EXTERN void png_handle_tRNS PNGARG((png_structp png_ptr, png_infop info_ptr,
  963.     png_uint_32 length));
  964. #endif
  965.  
  966. #ifdef PNG_READ_zTXt_SUPPORTED
  967. PNG_EXTERN void png_handle_zTXt PNGARG((png_structp png_ptr, png_infop info_ptr,
  968.     png_uint_32 length));
  969. #endif
  970.  
  971. PNG_EXTERN void png_handle_unknown PNGARG((png_structp png_ptr,
  972.     png_infop info_ptr, png_uint_32 length));
  973.  
  974. PNG_EXTERN void png_check_chunk_name PNGARG((png_structp png_ptr,
  975.     png_const_bytep chunk_name));
  976.  
  977. /* Handle the transformations for reading and writing */
  978. PNG_EXTERN void png_do_read_transformations PNGARG((png_structp png_ptr));
  979. PNG_EXTERN void png_do_write_transformations PNGARG((png_structp png_ptr));
  980.  
  981. PNG_EXTERN void png_init_read_transformations PNGARG((png_structp png_ptr));
  982.  
  983. #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
  984. PNG_EXTERN void png_push_read_chunk PNGARG((png_structp png_ptr,
  985.     png_infop info_ptr));
  986. PNG_EXTERN void png_push_read_sig PNGARG((png_structp png_ptr,
  987.     png_infop info_ptr));
  988. PNG_EXTERN void png_push_check_crc PNGARG((png_structp png_ptr));
  989. PNG_EXTERN void png_push_crc_skip PNGARG((png_structp png_ptr,
  990.     png_uint_32 length));
  991. PNG_EXTERN void png_push_crc_finish PNGARG((png_structp png_ptr));
  992. PNG_EXTERN void png_push_save_buffer PNGARG((png_structp png_ptr));
  993. PNG_EXTERN void png_push_restore_buffer PNGARG((png_structp png_ptr,
  994.     png_bytep buffer, png_size_t buffer_length));
  995. PNG_EXTERN void png_push_read_IDAT PNGARG((png_structp png_ptr));
  996. PNG_EXTERN void png_process_IDAT_data PNGARG((png_structp png_ptr,
  997.     png_bytep buffer, png_size_t buffer_length));
  998. PNG_EXTERN void png_push_process_row PNGARG((png_structp png_ptr));
  999. PNG_EXTERN void png_push_handle_unknown PNGARG((png_structp png_ptr,
  1000.    png_infop info_ptr, png_uint_32 length));
  1001. PNG_EXTERN void png_push_have_info PNGARG((png_structp png_ptr,
  1002.    png_infop info_ptr));
  1003. PNG_EXTERN void png_push_have_end PNGARG((png_structp png_ptr,
  1004.    png_infop info_ptr));
  1005. PNG_EXTERN void png_push_have_row PNGARG((png_structp png_ptr, png_bytep row));
  1006. PNG_EXTERN void png_push_read_end PNGARG((png_structp png_ptr,
  1007.     png_infop info_ptr));
  1008. PNG_EXTERN void png_process_some_data PNGARG((png_structp png_ptr,
  1009.     png_infop info_ptr));
  1010. PNG_EXTERN void png_read_push_finish_row PNGARG((png_structp png_ptr));
  1011. #  ifdef PNG_READ_tEXt_SUPPORTED
  1012. PNG_EXTERN void png_push_handle_tEXt PNGARG((png_structp png_ptr,
  1013.     png_infop info_ptr, png_uint_32 length));
  1014. PNG_EXTERN void png_push_read_tEXt PNGARG((png_structp png_ptr,
  1015.     png_infop info_ptr));
  1016. #  endif
  1017. #  ifdef PNG_READ_zTXt_SUPPORTED
  1018. PNG_EXTERN void png_push_handle_zTXt PNGARG((png_structp png_ptr,
  1019.     png_infop info_ptr, png_uint_32 length));
  1020. PNG_EXTERN void png_push_read_zTXt PNGARG((png_structp png_ptr,
  1021.     png_infop info_ptr));
  1022. #  endif
  1023. #  ifdef PNG_READ_iTXt_SUPPORTED
  1024. PNG_EXTERN void png_push_handle_iTXt PNGARG((png_structp png_ptr,
  1025.     png_infop info_ptr, png_uint_32 length));
  1026. PNG_EXTERN void png_push_read_iTXt PNGARG((png_structp png_ptr,
  1027.     png_infop info_ptr));
  1028. #  endif
  1029.  
  1030. #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
  1031.  
  1032. #ifdef PNG_MNG_FEATURES_SUPPORTED
  1033. PNG_EXTERN void png_do_read_intrapixel PNGARG((png_row_infop row_info,
  1034.     png_bytep row));
  1035. PNG_EXTERN void png_do_write_intrapixel PNGARG((png_row_infop row_info,
  1036.     png_bytep row));
  1037. #endif
  1038.  
  1039. /* Added at libpng version 1.4.0 */
  1040. #ifdef PNG_CHECK_cHRM_SUPPORTED
  1041. PNG_EXTERN int png_check_cHRM_fixed PNGARG((png_structp png_ptr,
  1042.     png_fixed_point int_white_x, png_fixed_point int_white_y,
  1043.     png_fixed_point int_red_x, png_fixed_point int_red_y, png_fixed_point
  1044.     int_green_x, png_fixed_point int_green_y, png_fixed_point int_blue_x,
  1045.     png_fixed_point int_blue_y));
  1046. #endif
  1047.  
  1048. #ifdef PNG_CHECK_cHRM_SUPPORTED
  1049. /* Added at libpng version 1.2.34 and 1.4.0 */
  1050. /* Currently only used by png_check_cHRM_fixed */
  1051. PNG_EXTERN void png_64bit_product PNGARG((long v1, long v2,
  1052.     unsigned long *hi_product, unsigned long *lo_product));
  1053. #endif
  1054.  
  1055. /* Added at libpng version 1.4.0 */
  1056. PNG_EXTERN void png_check_IHDR PNGARG((png_structp png_ptr,
  1057.     png_uint_32 width, png_uint_32 height, int bit_depth,
  1058.     int color_type, int interlace_type, int compression_type,
  1059.     int filter_type));
  1060.  
  1061. /* Free all memory used by the read (old method - NOT DLL EXPORTED) */
  1062. PNG_EXTERN void png_read_destroy PNGARG((png_structp png_ptr,
  1063.     png_infop info_ptr, png_infop end_info_ptr));
  1064.  
  1065. /* Free any memory used in png_ptr struct (old method - NOT DLL EXPORTED) */
  1066. PNG_EXTERN void png_write_destroy PNGARG((png_structp png_ptr));
  1067.  
  1068. #ifdef USE_FAR_KEYWORD  /* memory model conversion function */
  1069. PNG_EXTERN void *png_far_to_near PNGARG((png_structp png_ptr, png_voidp ptr,
  1070.     int check));
  1071. #endif /* USE_FAR_KEYWORD */
  1072.  
  1073. #if defined(PNG_FLOATING_POINT_SUPPORTED) && defined(PNG_ERROR_TEXT_SUPPORTED)
  1074. PNG_EXTERN PNG_FUNCTION(void, png_fixed_error, (png_structp png_ptr,
  1075.    png_const_charp name),PNG_NORETURN);
  1076. #endif
  1077.  
  1078. /* ASCII to FP interfaces, currently only implemented if sCAL
  1079.  * support is required.
  1080.  */
  1081. #if defined(PNG_READ_sCAL_SUPPORTED)
  1082. /* MAX_DIGITS is actually the maximum number of characters in an sCAL
  1083.  * width or height, derived from the precision (number of significant
  1084.  * digits - a build time settable option) and assumpitions about the
  1085.  * maximum ridiculous exponent.
  1086.  */
  1087. #define PNG_sCAL_MAX_DIGITS (PNG_sCAL_PRECISION+1/*.*/+1/*E*/+10/*exponent*/)
  1088.  
  1089. #ifdef PNG_FLOATING_POINT_SUPPORTED
  1090. PNG_EXTERN void png_ascii_from_fp PNGARG((png_structp png_ptr, png_charp ascii,
  1091.     png_size_t size, double fp, unsigned int precision));
  1092. #endif /* FLOATING_POINT */
  1093.  
  1094. #ifdef PNG_FIXED_POINT_SUPPORTED
  1095. PNG_EXTERN void png_ascii_from_fixed PNGARG((png_structp png_ptr,
  1096.     png_charp ascii, png_size_t size, png_fixed_point fp));
  1097. #endif /* FIXED_POINT */
  1098. #endif /* READ_sCAL */
  1099.  
  1100. #if defined(PNG_sCAL_SUPPORTED) || defined(PNG_pCAL_SUPPORTED)
  1101. /* An internal API to validate the format of a floating point number.
  1102.  * The result is the index of the next character.  If the number is
  1103.  * not valid it will be the index of a character in the supposed number.
  1104.  *
  1105.  * The format of a number is defined in the PNG extensions specification
  1106.  * and this API is strictly conformant to that spec, not anyone elses!
  1107.  *
  1108.  * The format as a regular expression is:
  1109.  *
  1110.  * [+-]?[0-9]+.?([Ee][+-]?[0-9]+)?
  1111.  *
  1112.  * or:
  1113.  *
  1114.  * [+-]?.[0-9]+(.[0-9]+)?([Ee][+-]?[0-9]+)?
  1115.  *
  1116.  * The complexity is that either integer or fraction must be present and the
  1117.  * fraction is permitted to have no digits only if the integer is present.
  1118.  *
  1119.  * NOTE: The dangling E problem.
  1120.  *   There is a PNG valid floating point number in the following:
  1121.  *
  1122.  *       PNG floating point numb1.ers are not greedy.
  1123.  *
  1124.  *   Working this out requires *TWO* character lookahead (because of the
  1125.  *   sign), the parser does not do this - it will fail at the 'r' - this
  1126.  *   doesn't matter for PNG sCAL chunk values, but it requires more care
  1127.  *   if the value were ever to be embedded in something more complex.  Use
  1128.  *   ANSI-C strtod if you need the lookahead.
  1129.  */
  1130. /* State table for the parser. */
  1131. #define PNG_FP_INTEGER    0  /* before or in integer */
  1132. #define PNG_FP_FRACTION   1  /* before or in fraction */
  1133. #define PNG_FP_EXPONENT   2  /* before or in exponent */
  1134. #define PNG_FP_STATE      3  /* mask for the above */
  1135. #define PNG_FP_SAW_SIGN   4  /* Saw +/- in current state */
  1136. #define PNG_FP_SAW_DIGIT  8  /* Saw a digit in current state */
  1137. #define PNG_FP_SAW_DOT   16  /* Saw a dot in current state */
  1138. #define PNG_FP_SAW_E     32  /* Saw an E (or e) in current state */
  1139. #define PNG_FP_SAW_ANY   60  /* Saw any of the above 4 */
  1140. #define PNG_FP_WAS_VALID 64  /* Preceding substring is a valid fp number */
  1141. #define PNG_FP_INVALID  128  /* Available for callers as a distinct value */
  1142.  
  1143. /* Result codes for the parser (boolean - true meants ok, false means
  1144.  * not ok yet.)
  1145.  */
  1146. #define PNG_FP_MAYBE      0  /* The number may be valid in the future */
  1147. #define PNG_FP_OK         1  /* The number is valid */
  1148.  
  1149. /* The actual parser.  This can be called repeatedly, it updates
  1150.  * the index into the string and the state variable (which must
  1151.  * be initialzed to 0).  It returns a result code, as above.  There
  1152.  * is no point calling the parser any more if it fails to advance to
  1153.  * the end of the string - it is stuck on an invalid character (or
  1154.  * terminated by '\0').
  1155.  *
  1156.  * Note that the pointer will consume an E or even an E+ then leave
  1157.  * a 'maybe' state even though a preceding integer.fraction is valid.
  1158.  * The PNG_FP_WAS_VALID flag indicates that a preceding substring was
  1159.  * a valid number.  It's possible to recover from this by calling
  1160.  * the parser again (from the start, with state 0) but with a string
  1161.  * that omits the last character (i.e. set the size to the index of
  1162.  * the problem character.)  This has not been tested within libpng.
  1163.  */
  1164. PNG_EXTERN int png_check_fp_number PNGARG((png_const_charp string,
  1165.     png_size_t size, int *statep, png_size_tp whereami));
  1166.  
  1167. /* This is the same but it checks a complete string and returns true
  1168.  * only if it just contains a floating point number.
  1169.  */
  1170. PNG_EXTERN int png_check_fp_string PNGARG((png_const_charp string,
  1171.     png_size_t size));
  1172. #endif /* pCAL || sCAL */
  1173.  
  1174. #if defined(PNG_READ_GAMMA_SUPPORTED) ||\
  1175.     defined(PNG_INCH_CONVERSIONS_SUPPORTED) || defined(PNG_READ_pHYs_SUPPORTED)
  1176. /* Added at libpng version 1.5.0 */
  1177. /* This is a utility to provide a*times/div (rounded) and indicate
  1178.  * if there is an overflow.  The result is a boolean - false (0)
  1179.  * for overflow, true (1) if no overflow, in which case *res
  1180.  * holds the result.
  1181.  */
  1182. PNG_EXTERN int png_muldiv PNGARG((png_fixed_point_p res, png_fixed_point a,
  1183.     png_int_32 times, png_int_32 div));
  1184. #endif
  1185.  
  1186. #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_INCH_CONVERSIONS_SUPPORTED)
  1187. /* Same deal, but issue a warning on overflow and return 0. */
  1188. PNG_EXTERN png_fixed_point png_muldiv_warn PNGARG((png_structp png_ptr,
  1189.     png_fixed_point a, png_int_32 times, png_int_32 div));
  1190. #endif
  1191.  
  1192. #ifdef PNG_READ_GAMMA_SUPPORTED
  1193. /* Calculate a reciprocal - used for gamma values.  This returns
  1194.  * 0 if the argument is 0 in order to maintain an undefined value,
  1195.  * there are no warnings.
  1196.  */
  1197. PNG_EXTERN png_fixed_point png_reciprocal PNGARG((png_fixed_point a));
  1198.  
  1199. /* The same but gives a reciprocal of the product of two fixed point
  1200.  * values.  Accuracy is suitable for gamma calculations but this is
  1201.  * not exact - use png_muldiv for that.
  1202.  */
  1203. PNG_EXTERN png_fixed_point png_reciprocal2 PNGARG((png_fixed_point a,
  1204.     png_fixed_point b));
  1205. #endif
  1206.  
  1207. #ifdef PNG_READ_GAMMA_SUPPORTED
  1208. /* Internal fixed point gamma correction.  These APIs are called as
  1209.  * required to convert single values - they don't need to be fast,
  1210.  * they are not used when processing image pixel values.
  1211.  *
  1212.  * While the input is an 'unsigned' value it must actually be the
  1213.  * correct bit value - 0..255 or 0..65535 as required.
  1214.  */
  1215. PNG_EXTERN png_uint_16 png_gamma_correct PNGARG((png_structp png_ptr,
  1216.     unsigned int value, png_fixed_point gamma));
  1217. PNG_EXTERN int png_gamma_significant PNGARG((png_fixed_point gamma));
  1218. PNG_EXTERN png_uint_16 png_gamma_16bit_correct PNGARG((unsigned int value,
  1219.     png_fixed_point gamma));
  1220. PNG_EXTERN png_byte png_gamma_8bit_correct PNGARG((unsigned int value,
  1221.     png_fixed_point gamma));
  1222. PNG_EXTERN void png_build_gamma_table PNGARG((png_structp png_ptr,
  1223.     int bit_depth));
  1224. #endif
  1225.  
  1226. /* Maintainer: Put new private prototypes here ^ and in libpngpf.3 */
  1227.  
  1228.  
  1229. #include "pngdebug.h"
  1230.  
  1231. #ifdef __cplusplus
  1232. }
  1233. #endif
  1234.  
  1235. #endif /* PNGPRIV_H */
  1236.