pngpriv.h revision 5a242664149701e00be6eef18f93a5fe0635d949
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) 1998-2012 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 1.5.10 [March 29, 2012] 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/* 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/* This is required for the definition of abort(), used as a last ditch 43 * error handler when all else fails. 44 */ 45#include <stdlib.h> 46 47/* This is used to find 'offsetof', used below for alignment tests. */ 48#include <stddef.h> 49 50#define PNGLIB_BUILD /*libpng is being built, not used*/ 51 52#ifdef PNG_USER_CONFIG 53# include "pngusr.h" 54 /* These should have been defined in pngusr.h */ 55# ifndef PNG_USER_PRIVATEBUILD 56# define PNG_USER_PRIVATEBUILD "Custom libpng build" 57# endif 58# ifndef PNG_USER_DLLFNAME_POSTFIX 59# define PNG_USER_DLLFNAME_POSTFIX "Cb" 60# endif 61#endif 62 63/* Is this a build of a DLL where compilation of the object modules requires 64 * different preprocessor settings to those required for a simple library? If 65 * so PNG_BUILD_DLL must be set. 66 * 67 * If libpng is used inside a DLL but that DLL does not export the libpng APIs 68 * PNG_BUILD_DLL must not be set. To avoid the code below kicking in build a 69 * static library of libpng then link the DLL against that. 70 */ 71#ifndef PNG_BUILD_DLL 72# ifdef DLL_EXPORT 73 /* This is set by libtool when files are compiled for a DLL; libtool 74 * always compiles twice, even on systems where it isn't necessary. Set 75 * PNG_BUILD_DLL in case it is necessary: 76 */ 77# define PNG_BUILD_DLL 78# else 79# ifdef _WINDLL 80 /* This is set by the Microsoft Visual Studio IDE in projects that 81 * build a DLL. It can't easily be removed from those projects (it 82 * isn't visible in the Visual Studio UI) so it is a fairly reliable 83 * indication that PNG_IMPEXP needs to be set to the DLL export 84 * attributes. 85 */ 86# define PNG_BUILD_DLL 87# else 88# ifdef __DLL__ 89 /* This is set by the Borland C system when compiling for a DLL 90 * (as above.) 91 */ 92# define PNG_BUILD_DLL 93# else 94 /* Add additional compiler cases here. */ 95# endif 96# endif 97# endif 98#endif /* Setting PNG_BUILD_DLL if required */ 99 100/* See pngconf.h for more details: the builder of the library may set this on 101 * the command line to the right thing for the specific compilation system or it 102 * may be automagically set above (at present we know of no system where it does 103 * need to be set on the command line.) 104 * 105 * PNG_IMPEXP must be set here when building the library to prevent pngconf.h 106 * setting it to the "import" setting for a DLL build. 107 */ 108#ifndef PNG_IMPEXP 109# ifdef PNG_BUILD_DLL 110# define PNG_IMPEXP PNG_DLL_EXPORT 111# else 112 /* Not building a DLL, or the DLL doesn't require specific export 113 * definitions. 114 */ 115# define PNG_IMPEXP 116# endif 117#endif 118 119/* No warnings for private or deprecated functions in the build: */ 120#ifndef PNG_DEPRECATED 121# define PNG_DEPRECATED 122#endif 123#ifndef PNG_PRIVATE 124# define PNG_PRIVATE 125#endif 126 127#include "png.h" 128#include "pnginfo.h" 129#include "pngstruct.h" 130 131/* pngconf.h does not set PNG_DLL_EXPORT unless it is required, so: */ 132#ifndef PNG_DLL_EXPORT 133# define PNG_DLL_EXPORT 134#endif 135 136/* SECURITY and SAFETY: 137 * 138 * By default libpng is built without any internal limits on image size, 139 * individual heap (png_malloc) allocations or the total amount of memory used. 140 * If PNG_SAFE_LIMITS_SUPPORTED is defined, however, the limits below are used 141 * (unless individually overridden). These limits are believed to be fairly 142 * safe, but builders of secure systems should verify the values against the 143 * real system capabilities. 144 */ 145 146#ifdef PNG_SAFE_LIMITS_SUPPORTED 147 /* 'safe' limits */ 148# ifndef PNG_USER_WIDTH_MAX 149# define PNG_USER_WIDTH_MAX 1000000 150# endif 151# ifndef PNG_USER_HEIGHT_MAX 152# define PNG_USER_HEIGHT_MAX 1000000 153# endif 154# ifndef PNG_USER_CHUNK_CACHE_MAX 155# define PNG_USER_CHUNK_CACHE_MAX 128 156# endif 157# ifndef PNG_USER_CHUNK_MALLOC_MAX 158# define PNG_USER_CHUNK_MALLOC_MAX 8000000 159# endif 160#else 161 /* values for no limits */ 162# ifndef PNG_USER_WIDTH_MAX 163# define PNG_USER_WIDTH_MAX 0x7fffffff 164# endif 165# ifndef PNG_USER_HEIGHT_MAX 166# define PNG_USER_HEIGHT_MAX 0x7fffffff 167# endif 168# ifndef PNG_USER_CHUNK_CACHE_MAX 169# define PNG_USER_CHUNK_CACHE_MAX 0 170# endif 171# ifndef PNG_USER_CHUNK_MALLOC_MAX 172# define PNG_USER_CHUNK_MALLOC_MAX 0 173# endif 174#endif 175 176/* This is used for 16 bit gamma tables - only the top level pointers are const, 177 * this could be changed: 178 */ 179typedef PNG_CONST png_uint_16p FAR * png_const_uint_16pp; 180 181/* Added at libpng-1.2.9 */ 182/* Moved to pngpriv.h at libpng-1.5.0 */ 183 184/* config.h is created by and PNG_CONFIGURE_LIBPNG is set by the "configure" 185 * script. We may need it here to get the correct configuration on things 186 * like limits. 187 */ 188#ifdef PNG_CONFIGURE_LIBPNG 189# ifdef HAVE_CONFIG_H 190# include "config.h" 191# endif 192#endif 193 194/* Moved to pngpriv.h at libpng-1.5.0 */ 195/* NOTE: some of these may have been used in external applications as 196 * these definitions were exposed in pngconf.h prior to 1.5. 197 */ 198 199/* If you are running on a machine where you cannot allocate more 200 * than 64K of memory at once, uncomment this. While libpng will not 201 * normally need that much memory in a chunk (unless you load up a very 202 * large file), zlib needs to know how big of a chunk it can use, and 203 * libpng thus makes sure to check any memory allocation to verify it 204 * will fit into memory. 205 * 206 * zlib provides 'MAXSEG_64K' which, if defined, indicates the 207 * same limit and pngconf.h (already included) sets the limit 208 * if certain operating systems are detected. 209 */ 210#if defined(MAXSEG_64K) && !defined(PNG_MAX_MALLOC_64K) 211# define PNG_MAX_MALLOC_64K 212#endif 213 214#ifndef PNG_UNUSED 215/* Unused formal parameter warnings are silenced using the following macro 216 * which is expected to have no bad effects on performance (optimizing 217 * compilers will probably remove it entirely). Note that if you replace 218 * it with something other than whitespace, you must include the terminating 219 * semicolon. 220 */ 221# define PNG_UNUSED(param) (void)param; 222#endif 223 224/* Just a little check that someone hasn't tried to define something 225 * contradictory. 226 */ 227#if (PNG_ZBUF_SIZE > 65536L) && defined(PNG_MAX_MALLOC_64K) 228# undef PNG_ZBUF_SIZE 229# define PNG_ZBUF_SIZE 65536L 230#endif 231 232/* PNG_STATIC is used to mark internal file scope functions if they need to be 233 * accessed for implementation tests (see the code in tests/?*). 234 */ 235#ifndef PNG_STATIC 236# define PNG_STATIC static 237#endif 238 239/* C99 restrict is used where possible, to do this 'restrict' is defined as 240 * empty if we can't be sure it is supported. configure builds have already 241 * done this work. 242 */ 243#ifdef PNG_CONFIGURE_LIBPNG 244# define PNG_RESTRICT restrict 245#else 246 /* Modern compilers support restrict, but assume not for anything not 247 * recognized here: 248 */ 249# if defined __GNUC__ || defined _MSC_VER || defined __WATCOMC__ 250# define PNG_RESTRICT restrict 251# else 252# define PNG_RESTRICT 253# endif 254#endif 255 256/* If warnings or errors are turned off the code is disabled or redirected here. 257 * From 1.5.4 functions have been added to allow very limited formatting of 258 * error and warning messages - this code will also be disabled here. 259 */ 260#ifdef PNG_WARNINGS_SUPPORTED 261# define PNG_WARNING_PARAMETERS(p) png_warning_parameters p; 262#else 263# define png_warning(s1,s2) ((void)(s1)) 264# define png_chunk_warning(s1,s2) ((void)(s1)) 265# define png_warning_parameter(p,number,string) ((void)0) 266# define png_warning_parameter_unsigned(p,number,format,value) ((void)0) 267# define png_warning_parameter_signed(p,number,format,value) ((void)0) 268# define png_formatted_warning(pp,p,message) ((void)(pp)) 269# define PNG_WARNING_PARAMETERS(p) 270#endif 271#ifndef PNG_ERROR_TEXT_SUPPORTED 272# define png_error(s1,s2) png_err(s1) 273# define png_chunk_error(s1,s2) png_err(s1) 274# define png_fixed_error(s1,s2) png_err(s1) 275#endif 276 277/* C allows up-casts from (void*) to any pointer and (const void*) to any 278 * pointer to a const object. C++ regards this as a type error and requires an 279 * explicit, static, cast and provides the static_cast<> rune to ensure that 280 * const is not cast away. 281 */ 282#ifdef __cplusplus 283# define png_voidcast(type, value) static_cast<type>(value) 284#else 285# define png_voidcast(type, value) (value) 286#endif /* __cplusplus */ 287 288#ifndef PNG_EXTERN 289/* The functions exported by PNG_EXTERN are internal functions, which 290 * aren't usually used outside the library (as far as I know), so it is 291 * debatable if they should be exported at all. In the future, when it 292 * is possible to have run-time registry of chunk-handling functions, 293 * some of these might be made available again. 294 * 295 * 1.5.7: turned the use of 'extern' back on, since it is localized to pngpriv.h 296 * it should be safe now (it is unclear why it was turned off.) 297 */ 298# define PNG_EXTERN extern 299#endif 300 301/* Some fixed point APIs are still required even if not exported because 302 * they get used by the corresponding floating point APIs. This magic 303 * deals with this: 304 */ 305#ifdef PNG_FIXED_POINT_SUPPORTED 306# define PNGFAPI PNGAPI 307#else 308# define PNGFAPI /* PRIVATE */ 309#endif 310 311/* Other defines specific to compilers can go here. Try to keep 312 * them inside an appropriate ifdef/endif pair for portability. 313 */ 314#if defined(PNG_FLOATING_POINT_SUPPORTED) ||\ 315 defined(PNG_FLOATING_ARITHMETIC_SUPPORTED) 316 /* png.c requires the following ANSI-C constants if the conversion of 317 * floating point to ASCII is implemented therein: 318 * 319 * DBL_DIG Maximum number of decimal digits (can be set to any constant) 320 * DBL_MIN Smallest normalized fp number (can be set to an arbitrary value) 321 * DBL_MAX Maximum floating point number (can be set to an arbitrary value) 322 */ 323# include <float.h> 324 325# if (defined(__MWERKS__) && defined(macintosh)) || defined(applec) || \ 326 defined(THINK_C) || defined(__SC__) || defined(TARGET_OS_MAC) 327 /* We need to check that <math.h> hasn't already been included earlier 328 * as it seems it doesn't agree with <fp.h>, yet we should really use 329 * <fp.h> if possible. 330 */ 331# if !defined(__MATH_H__) && !defined(__MATH_H) && !defined(__cmath__) 332# include <fp.h> 333# endif 334# else 335# include <math.h> 336# endif 337# if defined(_AMIGA) && defined(__SASC) && defined(_M68881) 338 /* Amiga SAS/C: We must include builtin FPU functions when compiling using 339 * MATH=68881 340 */ 341# include <m68881.h> 342# endif 343#endif 344 345/* This provides the non-ANSI (far) memory allocation routines. */ 346#if defined(__TURBOC__) && defined(__MSDOS__) 347# include <mem.h> 348# include <alloc.h> 349#endif 350 351#if defined(WIN32) || defined(_Windows) || defined(_WINDOWS) || \ 352 defined(_WIN32) || defined(__WIN32__) 353# include <windows.h> /* defines _WINDOWS_ macro */ 354#endif 355 356/* Moved here around 1.5.0beta36 from pngconf.h */ 357/* Users may want to use these so they are not private. Any library 358 * functions that are passed far data must be model-independent. 359 */ 360 361/* Memory model/platform independent fns */ 362#ifndef PNG_ABORT 363# ifdef _WINDOWS_ 364# define PNG_ABORT() ExitProcess(0) 365# else 366# define PNG_ABORT() abort() 367# endif 368#endif 369 370#ifdef USE_FAR_KEYWORD 371/* Use this to make far-to-near assignments */ 372# define CHECK 1 373# define NOCHECK 0 374# define CVT_PTR(ptr) (png_far_to_near(png_ptr,ptr,CHECK)) 375# define CVT_PTR_NOCHECK(ptr) (png_far_to_near(png_ptr,ptr,NOCHECK)) 376# define png_strlen _fstrlen 377# define png_memcmp _fmemcmp /* SJT: added */ 378# define png_memcpy _fmemcpy 379# define png_memset _fmemset 380#else 381# ifdef _WINDOWS_ /* Favor Windows over C runtime fns */ 382# define CVT_PTR(ptr) (ptr) 383# define CVT_PTR_NOCHECK(ptr) (ptr) 384# define png_strlen lstrlenA 385# define png_memcmp memcmp 386# define png_memcpy CopyMemory 387# define png_memset memset 388# else 389# define CVT_PTR(ptr) (ptr) 390# define CVT_PTR_NOCHECK(ptr) (ptr) 391# define png_strlen strlen 392# define png_memcmp memcmp /* SJT: added */ 393# define png_memcpy memcpy 394# define png_memset memset 395# endif 396#endif 397 398/* These macros may need to be architecture dependent. */ 399#define PNG_ALIGN_NONE 0 /* do not use data alignment */ 400#define PNG_ALIGN_ALWAYS 1 /* assume unaligned accesses are OK */ 401#ifdef offsetof 402# define PNG_ALIGN_OFFSET 2 /* use offsetof to determine alignment */ 403#else 404# define PNG_ALIGN_OFFSET -1 /* prevent the use of this */ 405#endif 406#define PNG_ALIGN_SIZE 3 /* use sizeof to determine alignment */ 407 408#ifndef PNG_ALIGN_TYPE 409 /* Default to using aligned access optimizations and requiring alignment to a 410 * multiple of the data type size. Override in a compiler specific fashion 411 * if necessary by inserting tests here: 412 */ 413# define PNG_ALIGN_TYPE PNG_ALIGN_SIZE 414#endif 415 416#if PNG_ALIGN_TYPE == PNG_ALIGN_SIZE 417 /* This is used because in some compiler implementations non-aligned 418 * structure members are supported, so the offsetof approach below fails. 419 * Set PNG_ALIGN_TO_SIZE=0 for compiler combinations where unaligned access 420 * is good for performance. Do not do this unless you have tested the result 421 * and understand it. 422 */ 423# define png_alignof(type) (sizeof (type)) 424#else 425# if PNG_ALIGN_TYPE == PNG_ALIGN_OFFSET 426# define png_alignof(type) offsetof(struct{char c; type t;}, t) 427# else 428# if PNG_ALIGN_TYPE == PNG_ALIGN_ALWAYS 429# define png_alignof(type) (1) 430# endif 431 /* Else leave png_alignof undefined to prevent use thereof */ 432# endif 433#endif 434 435/* This implicitly assumes alignment is always to a power of 2. */ 436#ifdef png_alignof 437# define png_isaligned(ptr, type)\ 438 ((((const char*)ptr-(const char*)0) & (png_alignof(type)-1)) == 0) 439#else 440# define png_isaligned(ptr, type) 0 441#endif 442 443/* End of memory model/platform independent support */ 444/* End of 1.5.0beta36 move from pngconf.h */ 445 446/* CONSTANTS and UTILITY MACROS 447 * These are used internally by libpng and not exposed in the API 448 */ 449 450/* Various modes of operation. Note that after an init, mode is set to 451 * zero automatically when the structure is created. Three of these 452 * are defined in png.h because they need to be visible to applications 453 * that call png_set_unknown_chunk(). 454 */ 455/* #define PNG_HAVE_IHDR 0x01 (defined in png.h) */ 456/* #define PNG_HAVE_PLTE 0x02 (defined in png.h) */ 457#define PNG_HAVE_IDAT 0x04 458/* #define PNG_AFTER_IDAT 0x08 (defined in png.h) */ 459#define PNG_HAVE_IEND 0x10 460#define PNG_HAVE_gAMA 0x20 461#define PNG_HAVE_cHRM 0x40 462#define PNG_HAVE_sRGB 0x80 463#define PNG_HAVE_CHUNK_HEADER 0x100 464#define PNG_WROTE_tIME 0x200 465#define PNG_WROTE_INFO_BEFORE_PLTE 0x400 466#define PNG_BACKGROUND_IS_GRAY 0x800 467#define PNG_HAVE_PNG_SIGNATURE 0x1000 468#define PNG_HAVE_CHUNK_AFTER_IDAT 0x2000 /* Have another chunk after IDAT */ 469#define PNG_HAVE_iCCP 0x4000 470 471/* Flags for the transformations the PNG library does on the image data */ 472#define PNG_BGR 0x0001 473#define PNG_INTERLACE 0x0002 474#define PNG_PACK 0x0004 475#define PNG_SHIFT 0x0008 476#define PNG_SWAP_BYTES 0x0010 477#define PNG_INVERT_MONO 0x0020 478#define PNG_QUANTIZE 0x0040 479#define PNG_COMPOSE 0x0080 /* Was PNG_BACKGROUND */ 480#define PNG_BACKGROUND_EXPAND 0x0100 481#define PNG_EXPAND_16 0x0200 /* Added to libpng 1.5.2 */ 482#define PNG_16_TO_8 0x0400 /* Becomes 'chop' in 1.5.4 */ 483#define PNG_RGBA 0x0800 484#define PNG_EXPAND 0x1000 485#define PNG_GAMMA 0x2000 486#define PNG_GRAY_TO_RGB 0x4000 487#define PNG_FILLER 0x8000 488#define PNG_PACKSWAP 0x10000 489#define PNG_SWAP_ALPHA 0x20000 490#define PNG_STRIP_ALPHA 0x40000 491#define PNG_INVERT_ALPHA 0x80000 492#define PNG_USER_TRANSFORM 0x100000 493#define PNG_RGB_TO_GRAY_ERR 0x200000 494#define PNG_RGB_TO_GRAY_WARN 0x400000 495#define PNG_RGB_TO_GRAY 0x600000 /* two bits, RGB_TO_GRAY_ERR|WARN */ 496#define PNG_ENCODE_ALPHA 0x800000 /* Added to libpng-1.5.4 */ 497#define PNG_ADD_ALPHA 0x1000000 /* Added to libpng-1.2.7 */ 498#define PNG_EXPAND_tRNS 0x2000000 /* Added to libpng-1.2.9 */ 499#define PNG_SCALE_16_TO_8 0x4000000 /* Added to libpng-1.5.4 */ 500 /* 0x8000000 unused */ 501 /* 0x10000000 unused */ 502 /* 0x20000000 unused */ 503 /* 0x40000000 unused */ 504/* Flags for png_create_struct */ 505#define PNG_STRUCT_PNG 0x0001 506#define PNG_STRUCT_INFO 0x0002 507 508/* Scaling factor for filter heuristic weighting calculations */ 509#define PNG_WEIGHT_FACTOR (1<<(PNG_WEIGHT_SHIFT)) 510#define PNG_COST_FACTOR (1<<(PNG_COST_SHIFT)) 511 512/* Flags for the png_ptr->flags rather than declaring a byte for each one */ 513#define PNG_FLAG_ZLIB_CUSTOM_STRATEGY 0x0001 514#define PNG_FLAG_ZLIB_CUSTOM_LEVEL 0x0002 515#define PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL 0x0004 516#define PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS 0x0008 517#define PNG_FLAG_ZLIB_CUSTOM_METHOD 0x0010 518#define PNG_FLAG_ZLIB_FINISHED 0x0020 519#define PNG_FLAG_ROW_INIT 0x0040 520#define PNG_FLAG_FILLER_AFTER 0x0080 521#define PNG_FLAG_CRC_ANCILLARY_USE 0x0100 522#define PNG_FLAG_CRC_ANCILLARY_NOWARN 0x0200 523#define PNG_FLAG_CRC_CRITICAL_USE 0x0400 524#define PNG_FLAG_CRC_CRITICAL_IGNORE 0x0800 525#define PNG_FLAG_ASSUME_sRGB 0x1000 /* Added to libpng-1.5.4 */ 526#define PNG_FLAG_OPTIMIZE_ALPHA 0x2000 /* Added to libpng-1.5.4 */ 527#define PNG_FLAG_DETECT_UNINITIALIZED 0x4000 /* Added to libpng-1.5.4 */ 528#define PNG_FLAG_KEEP_UNKNOWN_CHUNKS 0x8000 529#define PNG_FLAG_KEEP_UNSAFE_CHUNKS 0x10000 530#define PNG_FLAG_LIBRARY_MISMATCH 0x20000 531#define PNG_FLAG_STRIP_ERROR_NUMBERS 0x40000 532#define PNG_FLAG_STRIP_ERROR_TEXT 0x80000 533#define PNG_FLAG_MALLOC_NULL_MEM_OK 0x100000 534 /* 0x200000 unused */ 535 /* 0x400000 unused */ 536#define PNG_FLAG_BENIGN_ERRORS_WARN 0x800000 /* Added to libpng-1.4.0 */ 537#define PNG_FLAG_ZTXT_CUSTOM_STRATEGY 0x1000000 /* 5 lines added */ 538#define PNG_FLAG_ZTXT_CUSTOM_LEVEL 0x2000000 /* to libpng-1.5.4 */ 539#define PNG_FLAG_ZTXT_CUSTOM_MEM_LEVEL 0x4000000 540#define PNG_FLAG_ZTXT_CUSTOM_WINDOW_BITS 0x8000000 541#define PNG_FLAG_ZTXT_CUSTOM_METHOD 0x10000000 542 /* 0x20000000 unused */ 543 /* 0x40000000 unused */ 544 545#define PNG_FLAG_CRC_ANCILLARY_MASK (PNG_FLAG_CRC_ANCILLARY_USE | \ 546 PNG_FLAG_CRC_ANCILLARY_NOWARN) 547 548#define PNG_FLAG_CRC_CRITICAL_MASK (PNG_FLAG_CRC_CRITICAL_USE | \ 549 PNG_FLAG_CRC_CRITICAL_IGNORE) 550 551#define PNG_FLAG_CRC_MASK (PNG_FLAG_CRC_ANCILLARY_MASK | \ 552 PNG_FLAG_CRC_CRITICAL_MASK) 553 554/* zlib.h declares a magic type 'uInt' that limits the amount of data that zlib 555 * can handle at once. This type need be no larger than 16 bits (so maximum of 556 * 65535), this define allows us to discover how big it is, but limited by the 557 * maximuum for png_size_t. The value can be overriden in a library build 558 * (pngusr.h, or set it in CPPFLAGS) and it works to set it to a considerably 559 * lower value (e.g. 255 works). A lower value may help memory usage (slightly) 560 * and may even improve performance on some systems (and degrade it on others.) 561 */ 562#ifndef ZLIB_IO_MAX 563# define ZLIB_IO_MAX ((uInt)-1) 564#endif 565 566/* Save typing and make code easier to understand */ 567 568#define PNG_COLOR_DIST(c1, c2) (abs((int)((c1).red) - (int)((c2).red)) + \ 569 abs((int)((c1).green) - (int)((c2).green)) + \ 570 abs((int)((c1).blue) - (int)((c2).blue))) 571 572/* Added to libpng-1.2.6 JB */ 573#define PNG_ROWBYTES(pixel_bits, width) \ 574 ((pixel_bits) >= 8 ? \ 575 ((png_size_t)(width) * (((png_size_t)(pixel_bits)) >> 3)) : \ 576 (( ((png_size_t)(width) * ((png_size_t)(pixel_bits))) + 7) >> 3) ) 577 578/* PNG_OUT_OF_RANGE returns true if value is outside the range 579 * ideal-delta..ideal+delta. Each argument is evaluated twice. 580 * "ideal" and "delta" should be constants, normally simple 581 * integers, "value" a variable. Added to libpng-1.2.6 JB 582 */ 583#define PNG_OUT_OF_RANGE(value, ideal, delta) \ 584 ( (value) < (ideal)-(delta) || (value) > (ideal)+(delta) ) 585 586/* Conversions between fixed and floating point, only defined if 587 * required (to make sure the code doesn't accidentally use float 588 * when it is supposedly disabled.) 589 */ 590#ifdef PNG_FLOATING_POINT_SUPPORTED 591/* The floating point conversion can't overflow, though it can and 592 * does lose accuracy relative to the original fixed point value. 593 * In practice this doesn't matter because png_fixed_point only 594 * stores numbers with very low precision. The png_ptr and s 595 * arguments are unused by default but are there in case error 596 * checking becomes a requirement. 597 */ 598#define png_float(png_ptr, fixed, s) (.00001 * (fixed)) 599 600/* The fixed point conversion performs range checking and evaluates 601 * its argument multiple times, so must be used with care. The 602 * range checking uses the PNG specification values for a signed 603 * 32 bit fixed point value except that the values are deliberately 604 * rounded-to-zero to an integral value - 21474 (21474.83 is roughly 605 * (2^31-1) * 100000). 's' is a string that describes the value being 606 * converted. 607 * 608 * NOTE: this macro will raise a png_error if the range check fails, 609 * therefore it is normally only appropriate to use this on values 610 * that come from API calls or other sources where an out of range 611 * error indicates a programming error, not a data error! 612 * 613 * NOTE: by default this is off - the macro is not used - because the 614 * function call saves a lot of code. 615 */ 616#ifdef PNG_FIXED_POINT_MACRO_SUPPORTED 617#define png_fixed(png_ptr, fp, s) ((fp) <= 21474 && (fp) >= -21474 ?\ 618 ((png_fixed_point)(100000 * (fp))) : (png_fixed_error(png_ptr, s),0)) 619#else 620PNG_EXTERN png_fixed_point png_fixed PNGARG((png_structp png_ptr, double fp, 621 png_const_charp text)); 622#endif 623#endif 624 625/* Constants for known chunk types. If you need to add a chunk, define the name 626 * here. For historical reasons these constants have the form png_<name>; i.e. 627 * the prefix is lower case. Please use decimal values as the parameters to 628 * match the ISO PNG specification and to avoid relying on the C locale 629 * interpretation of character values. 630 * 631 * Prior to 1.5.6 these constants were strings, as of 1.5.6 png_uint_32 values 632 * are computed and a new macro (PNG_STRING_FROM_CHUNK) added to allow a string 633 * to be generated if required. 634 * 635 * PNG_32b correctly produces a value shifted by up to 24 bits, even on 636 * architectures where (int) is only 16 bits. 637 */ 638#define PNG_32b(b,s) ((png_uint_32)(b) << (s)) 639#define PNG_CHUNK(b1,b2,b3,b4) \ 640 (PNG_32b(b1,24) | PNG_32b(b2,16) | PNG_32b(b3,8) | PNG_32b(b4,0)) 641 642#define png_IHDR PNG_CHUNK( 73, 72, 68, 82) 643#define png_IDAT PNG_CHUNK( 73, 68, 65, 84) 644#define png_IEND PNG_CHUNK( 73, 69, 78, 68) 645#define png_PLTE PNG_CHUNK( 80, 76, 84, 69) 646#define png_bKGD PNG_CHUNK( 98, 75, 71, 68) 647#define png_cHRM PNG_CHUNK( 99, 72, 82, 77) 648#define png_gAMA PNG_CHUNK(103, 65, 77, 65) 649#define png_hIST PNG_CHUNK(104, 73, 83, 84) 650#define png_iCCP PNG_CHUNK(105, 67, 67, 80) 651#define png_iTXt PNG_CHUNK(105, 84, 88, 116) 652#define png_oFFs PNG_CHUNK(111, 70, 70, 115) 653#define png_pCAL PNG_CHUNK(112, 67, 65, 76) 654#define png_sCAL PNG_CHUNK(115, 67, 65, 76) 655#define png_pHYs PNG_CHUNK(112, 72, 89, 115) 656#define png_sBIT PNG_CHUNK(115, 66, 73, 84) 657#define png_sPLT PNG_CHUNK(115, 80, 76, 84) 658#define png_sRGB PNG_CHUNK(115, 82, 71, 66) 659#define png_sTER PNG_CHUNK(115, 84, 69, 82) 660#define png_tEXt PNG_CHUNK(116, 69, 88, 116) 661#define png_tIME PNG_CHUNK(116, 73, 77, 69) 662#define png_tRNS PNG_CHUNK(116, 82, 78, 83) 663#define png_zTXt PNG_CHUNK(122, 84, 88, 116) 664 665/* The following will work on (signed char*) strings, whereas the get_uint_32 666 * macro will fail on top-bit-set values because of the sign extension. 667 */ 668#define PNG_CHUNK_FROM_STRING(s)\ 669 PNG_CHUNK(0xff&(s)[0], 0xff&(s)[1], 0xff&(s)[2], 0xff&(s)[3]) 670 671/* This uses (char), not (png_byte) to avoid warnings on systems where (char) is 672 * signed and the argument is a (char[]) This macro will fail miserably on 673 * systems where (char) is more than 8 bits. 674 */ 675#define PNG_STRING_FROM_CHUNK(s,c)\ 676 (void)(((char*)(s))[0]=(char)((c)>>24), ((char*)(s))[1]=(char)((c)>>16),\ 677 ((char*)(s))[2]=(char)((c)>>8), ((char*)(s))[3]=(char)((c))) 678 679/* Do the same but terminate with a null character. */ 680#define PNG_CSTRING_FROM_CHUNK(s,c)\ 681 (void)(PNG_STRING_FROM_CHUNK(s,c), ((char*)(s))[4] = 0) 682 683/* Test on flag values as defined in the spec (section 5.4): */ 684#define PNG_CHUNK_ANCILLIARY(c) (1 & ((c) >> 29)) 685#define PNG_CHUNK_CRITICAL(c) (!PNG_CHUNK_ANCILLIARY(c)) 686#define PNG_CHUNK_PRIVATE(c) (1 & ((c) >> 21)) 687#define PNG_CHUNK_RESERVED(c) (1 & ((c) >> 13)) 688#define PNG_CHUNK_SAFE_TO_COPY(c) (1 & ((c) >> 5)) 689 690/* Gamma values (new at libpng-1.5.4): */ 691#define PNG_GAMMA_MAC_OLD 151724 /* Assume '1.8' is really 2.2/1.45! */ 692#define PNG_GAMMA_MAC_INVERSE 65909 693#define PNG_GAMMA_sRGB_INVERSE 45455 694 695 696/* Inhibit C++ name-mangling for libpng functions but not for system calls. */ 697#ifdef __cplusplus 698extern "C" { 699#endif /* __cplusplus */ 700 701/* These functions are used internally in the code. They generally 702 * shouldn't be used unless you are writing code to add or replace some 703 * functionality in libpng. More information about most functions can 704 * be found in the files where the functions are located. 705 */ 706 707/* Check the user version string for compatibility, returns false if the version 708 * numbers aren't compatible. 709 */ 710PNG_EXTERN int png_user_version_check(png_structp png_ptr, 711 png_const_charp user_png_ver); 712 713/* Allocate memory for an internal libpng struct */ 714PNG_EXTERN PNG_FUNCTION(png_voidp,png_create_struct,PNGARG((int type)), 715 PNG_ALLOCATED); 716 717/* Free memory from internal libpng struct */ 718PNG_EXTERN void png_destroy_struct PNGARG((png_voidp struct_ptr)); 719 720PNG_EXTERN PNG_FUNCTION(png_voidp,png_create_struct_2, 721 PNGARG((int type, png_malloc_ptr malloc_fn, png_voidp mem_ptr)), 722 PNG_ALLOCATED); 723PNG_EXTERN void png_destroy_struct_2 PNGARG((png_voidp struct_ptr, 724 png_free_ptr free_fn, png_voidp mem_ptr)); 725 726/* Free any memory that info_ptr points to and reset struct. */ 727PNG_EXTERN void png_info_destroy PNGARG((png_structp png_ptr, 728 png_infop info_ptr)); 729 730/* Function to allocate memory for zlib. PNGAPI is disallowed. */ 731PNG_EXTERN PNG_FUNCTION(voidpf,png_zalloc,PNGARG((voidpf png_ptr, uInt items, 732 uInt size)),PNG_ALLOCATED); 733 734/* Function to free memory for zlib. PNGAPI is disallowed. */ 735PNG_EXTERN void png_zfree PNGARG((voidpf png_ptr, voidpf ptr)); 736 737/* Next four functions are used internally as callbacks. PNGCBAPI is required 738 * but not PNG_EXPORT. PNGAPI added at libpng version 1.2.3, changed to 739 * PNGCBAPI at 1.5.0 740 */ 741 742PNG_EXTERN void PNGCBAPI png_default_read_data PNGARG((png_structp png_ptr, 743 png_bytep data, png_size_t length)); 744 745#ifdef PNG_PROGRESSIVE_READ_SUPPORTED 746PNG_EXTERN void PNGCBAPI png_push_fill_buffer PNGARG((png_structp png_ptr, 747 png_bytep buffer, png_size_t length)); 748#endif 749 750PNG_EXTERN void PNGCBAPI png_default_write_data PNGARG((png_structp png_ptr, 751 png_bytep data, png_size_t length)); 752 753#ifdef PNG_WRITE_FLUSH_SUPPORTED 754# ifdef PNG_STDIO_SUPPORTED 755PNG_EXTERN void PNGCBAPI png_default_flush PNGARG((png_structp png_ptr)); 756# endif 757#endif 758 759/* Reset the CRC variable */ 760PNG_EXTERN void png_reset_crc PNGARG((png_structp png_ptr)); 761 762/* Write the "data" buffer to whatever output you are using */ 763PNG_EXTERN void png_write_data PNGARG((png_structp png_ptr, 764 png_const_bytep data, png_size_t length)); 765 766/* Read and check the PNG file signature */ 767PNG_EXTERN void png_read_sig PNGARG((png_structp png_ptr, png_infop info_ptr)); 768 769/* Read the chunk header (length + type name) */ 770PNG_EXTERN png_uint_32 png_read_chunk_header PNGARG((png_structp png_ptr)); 771 772/* Read data from whatever input you are using into the "data" buffer */ 773PNG_EXTERN void png_read_data PNGARG((png_structp png_ptr, png_bytep data, 774 png_size_t length)); 775 776/* Read bytes into buf, and update png_ptr->crc */ 777PNG_EXTERN void png_crc_read PNGARG((png_structp png_ptr, png_bytep buf, 778 png_size_t length)); 779 780/* Decompress data in a chunk that uses compression */ 781#if defined(PNG_READ_COMPRESSED_TEXT_SUPPORTED) 782PNG_EXTERN void png_decompress_chunk PNGARG((png_structp png_ptr, 783 int comp_type, png_size_t chunklength, png_size_t prefix_length, 784 png_size_t *data_length)); 785#endif 786 787/* Read "skip" bytes, read the file crc, and (optionally) verify png_ptr->crc */ 788PNG_EXTERN int png_crc_finish PNGARG((png_structp png_ptr, png_uint_32 skip)); 789 790/* Read the CRC from the file and compare it to the libpng calculated CRC */ 791PNG_EXTERN int png_crc_error PNGARG((png_structp png_ptr)); 792 793/* Calculate the CRC over a section of data. Note that we are only 794 * passing a maximum of 64K on systems that have this as a memory limit, 795 * since this is the maximum buffer size we can specify. 796 */ 797PNG_EXTERN void png_calculate_crc PNGARG((png_structp png_ptr, 798 png_const_bytep ptr, png_size_t length)); 799 800#ifdef PNG_WRITE_FLUSH_SUPPORTED 801PNG_EXTERN void png_flush PNGARG((png_structp png_ptr)); 802#endif 803 804/* Write various chunks */ 805 806/* Write the IHDR chunk, and update the png_struct with the necessary 807 * information. 808 */ 809PNG_EXTERN void png_write_IHDR PNGARG((png_structp png_ptr, png_uint_32 width, 810 png_uint_32 height, 811 int bit_depth, int color_type, int compression_method, int filter_method, 812 int interlace_method)); 813 814PNG_EXTERN void png_write_PLTE PNGARG((png_structp png_ptr, 815 png_const_colorp palette, png_uint_32 num_pal)); 816 817PNG_EXTERN void png_write_IDAT PNGARG((png_structp png_ptr, png_bytep data, 818 png_size_t length)); 819 820PNG_EXTERN void png_write_IEND PNGARG((png_structp png_ptr)); 821 822#ifdef PNG_WRITE_gAMA_SUPPORTED 823# ifdef PNG_FLOATING_POINT_SUPPORTED 824PNG_EXTERN void png_write_gAMA PNGARG((png_structp png_ptr, double file_gamma)); 825# endif 826# ifdef PNG_FIXED_POINT_SUPPORTED 827PNG_EXTERN void png_write_gAMA_fixed PNGARG((png_structp png_ptr, 828 png_fixed_point file_gamma)); 829# endif 830#endif 831 832#ifdef PNG_WRITE_sBIT_SUPPORTED 833PNG_EXTERN void png_write_sBIT PNGARG((png_structp png_ptr, 834 png_const_color_8p sbit, int color_type)); 835#endif 836 837#ifdef PNG_WRITE_cHRM_SUPPORTED 838# ifdef PNG_FLOATING_POINT_SUPPORTED 839PNG_EXTERN void png_write_cHRM PNGARG((png_structp png_ptr, 840 double white_x, double white_y, 841 double red_x, double red_y, double green_x, double green_y, 842 double blue_x, double blue_y)); 843# endif 844PNG_EXTERN void png_write_cHRM_fixed PNGARG((png_structp png_ptr, 845 png_fixed_point int_white_x, png_fixed_point int_white_y, 846 png_fixed_point int_red_x, png_fixed_point int_red_y, png_fixed_point 847 int_green_x, png_fixed_point int_green_y, png_fixed_point int_blue_x, 848 png_fixed_point int_blue_y)); 849#endif 850 851#ifdef PNG_WRITE_sRGB_SUPPORTED 852PNG_EXTERN void png_write_sRGB PNGARG((png_structp png_ptr, 853 int intent)); 854#endif 855 856#ifdef PNG_WRITE_iCCP_SUPPORTED 857PNG_EXTERN void png_write_iCCP PNGARG((png_structp png_ptr, 858 png_const_charp name, int compression_type, 859 png_const_charp profile, int proflen)); 860 /* Note to maintainer: profile should be png_bytep */ 861#endif 862 863#ifdef PNG_WRITE_sPLT_SUPPORTED 864PNG_EXTERN void png_write_sPLT PNGARG((png_structp png_ptr, 865 png_const_sPLT_tp palette)); 866#endif 867 868#ifdef PNG_WRITE_tRNS_SUPPORTED 869PNG_EXTERN void png_write_tRNS PNGARG((png_structp png_ptr, 870 png_const_bytep trans, png_const_color_16p values, int number, 871 int color_type)); 872#endif 873 874#ifdef PNG_WRITE_bKGD_SUPPORTED 875PNG_EXTERN void png_write_bKGD PNGARG((png_structp png_ptr, 876 png_const_color_16p values, int color_type)); 877#endif 878 879#ifdef PNG_WRITE_hIST_SUPPORTED 880PNG_EXTERN void png_write_hIST PNGARG((png_structp png_ptr, 881 png_const_uint_16p hist, int num_hist)); 882#endif 883 884/* Chunks that have keywords */ 885#if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_pCAL_SUPPORTED) || \ 886 defined(PNG_WRITE_iCCP_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED) 887PNG_EXTERN png_size_t png_check_keyword PNGARG((png_structp png_ptr, 888 png_const_charp key, png_charpp new_key)); 889#endif 890 891#ifdef PNG_WRITE_tEXt_SUPPORTED 892PNG_EXTERN void png_write_tEXt PNGARG((png_structp png_ptr, png_const_charp key, 893 png_const_charp text, png_size_t text_len)); 894#endif 895 896#ifdef PNG_WRITE_zTXt_SUPPORTED 897PNG_EXTERN void png_write_zTXt PNGARG((png_structp png_ptr, png_const_charp key, 898 png_const_charp text, png_size_t text_len, int compression)); 899#endif 900 901#ifdef PNG_WRITE_iTXt_SUPPORTED 902PNG_EXTERN void png_write_iTXt PNGARG((png_structp png_ptr, 903 int compression, png_const_charp key, png_const_charp lang, 904 png_const_charp lang_key, png_const_charp text)); 905#endif 906 907#ifdef PNG_TEXT_SUPPORTED /* Added at version 1.0.14 and 1.2.4 */ 908PNG_EXTERN int png_set_text_2 PNGARG((png_structp png_ptr, 909 png_infop info_ptr, png_const_textp text_ptr, int num_text)); 910#endif 911 912#ifdef PNG_WRITE_oFFs_SUPPORTED 913PNG_EXTERN void png_write_oFFs PNGARG((png_structp png_ptr, 914 png_int_32 x_offset, png_int_32 y_offset, int unit_type)); 915#endif 916 917#ifdef PNG_WRITE_pCAL_SUPPORTED 918PNG_EXTERN void png_write_pCAL PNGARG((png_structp png_ptr, png_charp purpose, 919 png_int_32 X0, png_int_32 X1, int type, int nparams, 920 png_const_charp units, png_charpp params)); 921#endif 922 923#ifdef PNG_WRITE_pHYs_SUPPORTED 924PNG_EXTERN void png_write_pHYs PNGARG((png_structp png_ptr, 925 png_uint_32 x_pixels_per_unit, png_uint_32 y_pixels_per_unit, 926 int unit_type)); 927#endif 928 929#ifdef PNG_WRITE_tIME_SUPPORTED 930PNG_EXTERN void png_write_tIME PNGARG((png_structp png_ptr, 931 png_const_timep mod_time)); 932#endif 933 934#ifdef PNG_WRITE_sCAL_SUPPORTED 935PNG_EXTERN void png_write_sCAL_s PNGARG((png_structp png_ptr, 936 int unit, png_const_charp width, png_const_charp height)); 937#endif 938 939/* Called when finished processing a row of data */ 940PNG_EXTERN void png_write_finish_row PNGARG((png_structp png_ptr)); 941 942/* Internal use only. Called before first row of data */ 943PNG_EXTERN void png_write_start_row PNGARG((png_structp png_ptr)); 944 945/* Combine a row of data, dealing with alpha, etc. if requested. 'row' is an 946 * array of png_ptr->width pixels. If the image is not interlaced or this 947 * is the final pass this just does a png_memcpy, otherwise the "display" flag 948 * is used to determine whether to copy pixels that are not in the current pass. 949 * 950 * Because 'png_do_read_interlace' (below) replicates pixels this allows this 951 * function to achieve the documented 'blocky' appearance during interlaced read 952 * if display is 1 and the 'sparkle' appearance, where existing pixels in 'row' 953 * are not changed if they are not in the current pass, when display is 0. 954 * 955 * 'display' must be 0 or 1, otherwise the memcpy will be done regardless. 956 * 957 * The API always reads from the png_struct row buffer and always assumes that 958 * it is full width (png_do_read_interlace has already been called.) 959 * 960 * This function is only ever used to write to row buffers provided by the 961 * caller of the relevant libpng API and the row must have already been 962 * transformed by the read transformations. 963 * 964 * The PNG_USE_COMPILE_TIME_MASKS option causes generation of pre-computed 965 * bitmasks for use within the code, otherwise runtime generated masks are used. 966 * The default is compile time masks. 967 */ 968#ifndef PNG_USE_COMPILE_TIME_MASKS 969# define PNG_USE_COMPILE_TIME_MASKS 1 970#endif 971PNG_EXTERN void png_combine_row PNGARG((png_structp png_ptr, png_bytep row, 972 int display)); 973 974#ifdef PNG_READ_INTERLACING_SUPPORTED 975/* Expand an interlaced row: the 'row_info' describes the pass data that has 976 * been read in and must correspond to the pixels in 'row', the pixels are 977 * expanded (moved apart) in 'row' to match the final layout, when doing this 978 * the pixels are *replicated* to the intervening space. This is essential for 979 * the correct operation of png_combine_row, above. 980 */ 981PNG_EXTERN void png_do_read_interlace PNGARG((png_row_infop row_info, 982 png_bytep row, int pass, png_uint_32 transformations)); 983#endif 984 985/* GRR TO DO (2.0 or whenever): simplify other internal calling interfaces */ 986 987#ifdef PNG_WRITE_INTERLACING_SUPPORTED 988/* Grab pixels out of a row for an interlaced pass */ 989PNG_EXTERN void png_do_write_interlace PNGARG((png_row_infop row_info, 990 png_bytep row, int pass)); 991#endif 992 993/* Unfilter a row: check the filter value before calling this, there is no point 994 * calling it for PNG_FILTER_VALUE_NONE. 995 */ 996PNG_EXTERN void png_read_filter_row PNGARG((png_structp pp, png_row_infop 997 row_info, png_bytep row, png_const_bytep prev_row, int filter)); 998 999PNG_EXTERN void png_read_filter_row_up_neon PNGARG((png_row_infop row_info, 1000 png_bytep row, png_const_bytep prev_row)); 1001PNG_EXTERN void png_read_filter_row_sub3_neon PNGARG((png_row_infop row_info, 1002 png_bytep row, png_const_bytep prev_row)); 1003PNG_EXTERN void png_read_filter_row_sub4_neon PNGARG((png_row_infop row_info, 1004 png_bytep row, png_const_bytep prev_row)); 1005PNG_EXTERN void png_read_filter_row_avg3_neon PNGARG((png_row_infop row_info, 1006 png_bytep row, png_const_bytep prev_row)); 1007PNG_EXTERN void png_read_filter_row_avg4_neon PNGARG((png_row_infop row_info, 1008 png_bytep row, png_const_bytep prev_row)); 1009PNG_EXTERN void png_read_filter_row_paeth3_neon PNGARG((png_row_infop row_info, 1010 png_bytep row, png_const_bytep prev_row)); 1011PNG_EXTERN void png_read_filter_row_paeth4_neon PNGARG((png_row_infop row_info, 1012 png_bytep row, png_const_bytep prev_row)); 1013 1014/* Choose the best filter to use and filter the row data */ 1015PNG_EXTERN void png_write_find_filter PNGARG((png_structp png_ptr, 1016 png_row_infop row_info)); 1017 1018/* Finish a row while reading, dealing with interlacing passes, etc. */ 1019PNG_EXTERN void png_read_finish_row PNGARG((png_structp png_ptr)); 1020 1021/* Initialize the row buffers, etc. */ 1022PNG_EXTERN void png_read_start_row PNGARG((png_structp png_ptr)); 1023 1024#ifdef PNG_READ_TRANSFORMS_SUPPORTED 1025/* Optional call to update the users info structure */ 1026PNG_EXTERN void png_read_transform_info PNGARG((png_structp png_ptr, 1027 png_infop info_ptr)); 1028#endif 1029 1030/* These are the functions that do the transformations */ 1031#ifdef PNG_READ_FILLER_SUPPORTED 1032PNG_EXTERN void png_do_read_filler PNGARG((png_row_infop row_info, 1033 png_bytep row, png_uint_32 filler, png_uint_32 flags)); 1034#endif 1035 1036#ifdef PNG_READ_SWAP_ALPHA_SUPPORTED 1037PNG_EXTERN void png_do_read_swap_alpha PNGARG((png_row_infop row_info, 1038 png_bytep row)); 1039#endif 1040 1041#ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED 1042PNG_EXTERN void png_do_write_swap_alpha PNGARG((png_row_infop row_info, 1043 png_bytep row)); 1044#endif 1045 1046#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED 1047PNG_EXTERN void png_do_read_invert_alpha PNGARG((png_row_infop row_info, 1048 png_bytep row)); 1049#endif 1050 1051#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED 1052PNG_EXTERN void png_do_write_invert_alpha PNGARG((png_row_infop row_info, 1053 png_bytep row)); 1054#endif 1055 1056#if defined(PNG_WRITE_FILLER_SUPPORTED) || \ 1057 defined(PNG_READ_STRIP_ALPHA_SUPPORTED) 1058PNG_EXTERN void png_do_strip_channel PNGARG((png_row_infop row_info, 1059 png_bytep row, int at_start)); 1060#endif 1061 1062#ifdef PNG_16BIT_SUPPORTED 1063#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED) 1064PNG_EXTERN void png_do_swap PNGARG((png_row_infop row_info, 1065 png_bytep row)); 1066#endif 1067#endif 1068 1069#if defined(PNG_READ_PACKSWAP_SUPPORTED) || \ 1070 defined(PNG_WRITE_PACKSWAP_SUPPORTED) 1071PNG_EXTERN void png_do_packswap PNGARG((png_row_infop row_info, 1072 png_bytep row)); 1073#endif 1074 1075#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED 1076PNG_EXTERN int png_do_rgb_to_gray PNGARG((png_structp png_ptr, 1077 png_row_infop row_info, png_bytep row)); 1078#endif 1079 1080#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED 1081PNG_EXTERN void png_do_gray_to_rgb PNGARG((png_row_infop row_info, 1082 png_bytep row)); 1083#endif 1084 1085#ifdef PNG_READ_PACK_SUPPORTED 1086PNG_EXTERN void png_do_unpack PNGARG((png_row_infop row_info, 1087 png_bytep row)); 1088#endif 1089 1090#ifdef PNG_READ_SHIFT_SUPPORTED 1091PNG_EXTERN void png_do_unshift PNGARG((png_row_infop row_info, 1092 png_bytep row, png_const_color_8p sig_bits)); 1093#endif 1094 1095#if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED) 1096PNG_EXTERN void png_do_invert PNGARG((png_row_infop row_info, 1097 png_bytep row)); 1098#endif 1099 1100#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED 1101PNG_EXTERN void png_do_scale_16_to_8 PNGARG((png_row_infop row_info, 1102 png_bytep row)); 1103#endif 1104 1105#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED 1106PNG_EXTERN void png_do_chop PNGARG((png_row_infop row_info, 1107 png_bytep row)); 1108#endif 1109 1110#ifdef PNG_READ_QUANTIZE_SUPPORTED 1111PNG_EXTERN void png_do_quantize PNGARG((png_row_infop row_info, 1112 png_bytep row, png_const_bytep palette_lookup, 1113 png_const_bytep quantize_lookup)); 1114 1115# ifdef PNG_CORRECT_PALETTE_SUPPORTED 1116PNG_EXTERN void png_correct_palette PNGARG((png_structp png_ptr, 1117 png_colorp palette, int num_palette)); 1118# endif 1119#endif 1120 1121#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED) 1122PNG_EXTERN void png_do_bgr PNGARG((png_row_infop row_info, 1123 png_bytep row)); 1124#endif 1125 1126#ifdef PNG_WRITE_PACK_SUPPORTED 1127PNG_EXTERN void png_do_pack PNGARG((png_row_infop row_info, 1128 png_bytep row, png_uint_32 bit_depth)); 1129#endif 1130 1131#ifdef PNG_WRITE_SHIFT_SUPPORTED 1132PNG_EXTERN void png_do_shift PNGARG((png_row_infop row_info, 1133 png_bytep row, png_const_color_8p bit_depth)); 1134#endif 1135 1136#if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\ 1137 defined(PNG_READ_ALPHA_MODE_SUPPORTED) 1138PNG_EXTERN void png_do_compose PNGARG((png_row_infop row_info, 1139 png_bytep row, png_structp png_ptr)); 1140#endif 1141 1142#ifdef PNG_READ_GAMMA_SUPPORTED 1143PNG_EXTERN void png_do_gamma PNGARG((png_row_infop row_info, 1144 png_bytep row, png_structp png_ptr)); 1145#endif 1146 1147#ifdef PNG_READ_ALPHA_MODE_SUPPORTED 1148PNG_EXTERN void png_do_encode_alpha PNGARG((png_row_infop row_info, 1149 png_bytep row, png_structp png_ptr)); 1150#endif 1151 1152#ifdef PNG_READ_EXPAND_SUPPORTED 1153PNG_EXTERN void png_do_expand_palette PNGARG((png_row_infop row_info, 1154 png_bytep row, png_const_colorp palette, png_const_bytep trans, 1155 int num_trans)); 1156PNG_EXTERN void png_do_expand PNGARG((png_row_infop row_info, 1157 png_bytep row, png_const_color_16p trans_color)); 1158#endif 1159 1160#ifdef PNG_READ_EXPAND_16_SUPPORTED 1161PNG_EXTERN void png_do_expand_16 PNGARG((png_row_infop row_info, 1162 png_bytep row)); 1163#endif 1164 1165/* The following decodes the appropriate chunks, and does error correction, 1166 * then calls the appropriate callback for the chunk if it is valid. 1167 */ 1168 1169/* Decode the IHDR chunk */ 1170PNG_EXTERN void png_handle_IHDR PNGARG((png_structp png_ptr, png_infop info_ptr, 1171 png_uint_32 length)); 1172PNG_EXTERN void png_handle_PLTE PNGARG((png_structp png_ptr, png_infop info_ptr, 1173 png_uint_32 length)); 1174PNG_EXTERN void png_handle_IEND PNGARG((png_structp png_ptr, png_infop info_ptr, 1175 png_uint_32 length)); 1176 1177#ifdef PNG_READ_bKGD_SUPPORTED 1178PNG_EXTERN void png_handle_bKGD PNGARG((png_structp png_ptr, png_infop info_ptr, 1179 png_uint_32 length)); 1180#endif 1181 1182#ifdef PNG_READ_cHRM_SUPPORTED 1183PNG_EXTERN void png_handle_cHRM PNGARG((png_structp png_ptr, png_infop info_ptr, 1184 png_uint_32 length)); 1185#endif 1186 1187#ifdef PNG_READ_gAMA_SUPPORTED 1188PNG_EXTERN void png_handle_gAMA PNGARG((png_structp png_ptr, png_infop info_ptr, 1189 png_uint_32 length)); 1190#endif 1191 1192#ifdef PNG_READ_hIST_SUPPORTED 1193PNG_EXTERN void png_handle_hIST PNGARG((png_structp png_ptr, png_infop info_ptr, 1194 png_uint_32 length)); 1195#endif 1196 1197#ifdef PNG_READ_iCCP_SUPPORTED 1198PNG_EXTERN void png_handle_iCCP PNGARG((png_structp png_ptr, png_infop info_ptr, 1199 png_uint_32 length)); 1200#endif /* PNG_READ_iCCP_SUPPORTED */ 1201 1202#ifdef PNG_READ_iTXt_SUPPORTED 1203PNG_EXTERN void png_handle_iTXt PNGARG((png_structp png_ptr, png_infop info_ptr, 1204 png_uint_32 length)); 1205#endif 1206 1207#ifdef PNG_READ_oFFs_SUPPORTED 1208PNG_EXTERN void png_handle_oFFs PNGARG((png_structp png_ptr, png_infop info_ptr, 1209 png_uint_32 length)); 1210#endif 1211 1212#ifdef PNG_READ_pCAL_SUPPORTED 1213PNG_EXTERN void png_handle_pCAL PNGARG((png_structp png_ptr, png_infop info_ptr, 1214 png_uint_32 length)); 1215#endif 1216 1217#ifdef PNG_READ_pHYs_SUPPORTED 1218PNG_EXTERN void png_handle_pHYs PNGARG((png_structp png_ptr, png_infop info_ptr, 1219 png_uint_32 length)); 1220#endif 1221 1222#ifdef PNG_READ_sBIT_SUPPORTED 1223PNG_EXTERN void png_handle_sBIT PNGARG((png_structp png_ptr, png_infop info_ptr, 1224 png_uint_32 length)); 1225#endif 1226 1227#ifdef PNG_READ_sCAL_SUPPORTED 1228PNG_EXTERN void png_handle_sCAL PNGARG((png_structp png_ptr, png_infop info_ptr, 1229 png_uint_32 length)); 1230#endif 1231 1232#ifdef PNG_READ_sPLT_SUPPORTED 1233PNG_EXTERN void png_handle_sPLT PNGARG((png_structp png_ptr, png_infop info_ptr, 1234 png_uint_32 length)); 1235#endif /* PNG_READ_sPLT_SUPPORTED */ 1236 1237#ifdef PNG_READ_sRGB_SUPPORTED 1238PNG_EXTERN void png_handle_sRGB PNGARG((png_structp png_ptr, png_infop info_ptr, 1239 png_uint_32 length)); 1240#endif 1241 1242#ifdef PNG_READ_tEXt_SUPPORTED 1243PNG_EXTERN void png_handle_tEXt PNGARG((png_structp png_ptr, png_infop info_ptr, 1244 png_uint_32 length)); 1245#endif 1246 1247#ifdef PNG_READ_tIME_SUPPORTED 1248PNG_EXTERN void png_handle_tIME PNGARG((png_structp png_ptr, png_infop info_ptr, 1249 png_uint_32 length)); 1250#endif 1251 1252#ifdef PNG_READ_tRNS_SUPPORTED 1253PNG_EXTERN void png_handle_tRNS PNGARG((png_structp png_ptr, png_infop info_ptr, 1254 png_uint_32 length)); 1255#endif 1256 1257#ifdef PNG_READ_zTXt_SUPPORTED 1258PNG_EXTERN void png_handle_zTXt PNGARG((png_structp png_ptr, png_infop info_ptr, 1259 png_uint_32 length)); 1260#endif 1261 1262PNG_EXTERN void png_handle_unknown PNGARG((png_structp png_ptr, 1263 png_infop info_ptr, png_uint_32 length)); 1264 1265PNG_EXTERN void png_check_chunk_name PNGARG((png_structp png_ptr, 1266 png_uint_32 chunk_name)); 1267 1268#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED 1269/* Exactly as png_handle_as_unknown() except that the argument is a 32-bit chunk 1270 * name, not a string. 1271 */ 1272PNG_EXTERN int png_chunk_unknown_handling PNGARG((png_structp png_ptr, 1273 png_uint_32 chunk_name)); 1274#endif 1275 1276/* Handle the transformations for reading and writing */ 1277#ifdef PNG_READ_TRANSFORMS_SUPPORTED 1278PNG_EXTERN void png_do_read_transformations PNGARG((png_structp png_ptr, 1279 png_row_infop row_info)); 1280#endif 1281#ifdef PNG_WRITE_TRANSFORMS_SUPPORTED 1282PNG_EXTERN void png_do_write_transformations PNGARG((png_structp png_ptr, 1283 png_row_infop row_info)); 1284#endif 1285 1286#ifdef PNG_READ_TRANSFORMS_SUPPORTED 1287PNG_EXTERN void png_init_read_transformations PNGARG((png_structp png_ptr)); 1288#endif 1289 1290#ifdef PNG_PROGRESSIVE_READ_SUPPORTED 1291PNG_EXTERN void png_push_read_chunk PNGARG((png_structp png_ptr, 1292 png_infop info_ptr)); 1293PNG_EXTERN void png_push_read_sig PNGARG((png_structp png_ptr, 1294 png_infop info_ptr)); 1295PNG_EXTERN void png_push_check_crc PNGARG((png_structp png_ptr)); 1296PNG_EXTERN void png_push_crc_skip PNGARG((png_structp png_ptr, 1297 png_uint_32 length)); 1298PNG_EXTERN void png_push_crc_finish PNGARG((png_structp png_ptr)); 1299PNG_EXTERN void png_push_save_buffer PNGARG((png_structp png_ptr)); 1300PNG_EXTERN void png_push_restore_buffer PNGARG((png_structp png_ptr, 1301 png_bytep buffer, png_size_t buffer_length)); 1302PNG_EXTERN void png_push_read_IDAT PNGARG((png_structp png_ptr)); 1303PNG_EXTERN void png_process_IDAT_data PNGARG((png_structp png_ptr, 1304 png_bytep buffer, png_size_t buffer_length)); 1305PNG_EXTERN void png_push_process_row PNGARG((png_structp png_ptr)); 1306PNG_EXTERN void png_push_handle_unknown PNGARG((png_structp png_ptr, 1307 png_infop info_ptr, png_uint_32 length)); 1308PNG_EXTERN void png_push_have_info PNGARG((png_structp png_ptr, 1309 png_infop info_ptr)); 1310PNG_EXTERN void png_push_have_end PNGARG((png_structp png_ptr, 1311 png_infop info_ptr)); 1312PNG_EXTERN void png_push_have_row PNGARG((png_structp png_ptr, png_bytep row)); 1313PNG_EXTERN void png_push_read_end PNGARG((png_structp png_ptr, 1314 png_infop info_ptr)); 1315PNG_EXTERN void png_process_some_data PNGARG((png_structp png_ptr, 1316 png_infop info_ptr)); 1317PNG_EXTERN void png_read_push_finish_row PNGARG((png_structp png_ptr)); 1318# ifdef PNG_READ_tEXt_SUPPORTED 1319PNG_EXTERN void png_push_handle_tEXt PNGARG((png_structp png_ptr, 1320 png_infop info_ptr, png_uint_32 length)); 1321PNG_EXTERN void png_push_read_tEXt PNGARG((png_structp png_ptr, 1322 png_infop info_ptr)); 1323# endif 1324# ifdef PNG_READ_zTXt_SUPPORTED 1325PNG_EXTERN void png_push_handle_zTXt PNGARG((png_structp png_ptr, 1326 png_infop info_ptr, png_uint_32 length)); 1327PNG_EXTERN void png_push_read_zTXt PNGARG((png_structp png_ptr, 1328 png_infop info_ptr)); 1329# endif 1330# ifdef PNG_READ_iTXt_SUPPORTED 1331PNG_EXTERN void png_push_handle_iTXt PNGARG((png_structp png_ptr, 1332 png_infop info_ptr, png_uint_32 length)); 1333PNG_EXTERN void png_push_read_iTXt PNGARG((png_structp png_ptr, 1334 png_infop info_ptr)); 1335# endif 1336 1337#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */ 1338 1339#ifdef PNG_MNG_FEATURES_SUPPORTED 1340PNG_EXTERN void png_do_read_intrapixel PNGARG((png_row_infop row_info, 1341 png_bytep row)); 1342PNG_EXTERN void png_do_write_intrapixel PNGARG((png_row_infop row_info, 1343 png_bytep row)); 1344#endif 1345 1346/* Added at libpng version 1.4.0 */ 1347#ifdef PNG_CHECK_cHRM_SUPPORTED 1348PNG_EXTERN int png_check_cHRM_fixed PNGARG((png_structp png_ptr, 1349 png_fixed_point int_white_x, png_fixed_point int_white_y, 1350 png_fixed_point int_red_x, png_fixed_point int_red_y, png_fixed_point 1351 int_green_x, png_fixed_point int_green_y, png_fixed_point int_blue_x, 1352 png_fixed_point int_blue_y)); 1353#endif 1354 1355#ifdef PNG_CHECK_cHRM_SUPPORTED 1356/* Added at libpng version 1.2.34 and 1.4.0 */ 1357/* Currently only used by png_check_cHRM_fixed */ 1358PNG_EXTERN void png_64bit_product PNGARG((long v1, long v2, 1359 unsigned long *hi_product, unsigned long *lo_product)); 1360#endif 1361 1362#ifdef PNG_cHRM_SUPPORTED 1363/* Added at libpng version 1.5.5 */ 1364typedef struct png_xy 1365{ 1366 png_fixed_point redx, redy; 1367 png_fixed_point greenx, greeny; 1368 png_fixed_point bluex, bluey; 1369 png_fixed_point whitex, whitey; 1370} png_xy; 1371 1372typedef struct png_XYZ 1373{ 1374 png_fixed_point redX, redY, redZ; 1375 png_fixed_point greenX, greenY, greenZ; 1376 png_fixed_point blueX, blueY, blueZ; 1377} png_XYZ; 1378 1379/* The conversion APIs return 0 on success, non-zero on a parameter error. They 1380 * allow conversion between the above representations of a color encoding. When 1381 * converting from XYZ end points to chromaticities the absolute magnitude of 1382 * the end points is lost, when converting back the sum of the Y values of the 1383 * three end points will be 1.0 1384 */ 1385PNG_EXTERN int png_xy_from_XYZ PNGARG((png_xy *xy, png_XYZ XYZ)); 1386PNG_EXTERN int png_XYZ_from_xy PNGARG((png_XYZ *XYZ, png_xy xy)); 1387PNG_EXTERN int png_XYZ_from_xy_checked PNGARG((png_structp png_ptr, 1388 png_XYZ *XYZ, png_xy xy)); 1389#endif 1390 1391/* Added at libpng version 1.4.0 */ 1392PNG_EXTERN void png_check_IHDR PNGARG((png_structp png_ptr, 1393 png_uint_32 width, png_uint_32 height, int bit_depth, 1394 int color_type, int interlace_type, int compression_type, 1395 int filter_type)); 1396 1397/* Added at libpng version 1.5.10 */ 1398#if defined(PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED) || \ 1399 defined(PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED) 1400PNG_EXTERN void png_do_check_palette_indexes PNGARG((png_structp png_ptr, 1401 png_row_infop row_info)); 1402#endif 1403 1404/* Free all memory used by the read (old method - NOT DLL EXPORTED) */ 1405PNG_EXTERN void png_read_destroy PNGARG((png_structp png_ptr, 1406 png_infop info_ptr, png_infop end_info_ptr)); 1407 1408/* Free any memory used in png_ptr struct (old method - NOT DLL EXPORTED) */ 1409PNG_EXTERN void png_write_destroy PNGARG((png_structp png_ptr)); 1410 1411#ifdef USE_FAR_KEYWORD /* memory model conversion function */ 1412PNG_EXTERN void *png_far_to_near PNGARG((png_structp png_ptr, png_voidp ptr, 1413 int check)); 1414#endif /* USE_FAR_KEYWORD */ 1415 1416#if defined(PNG_FLOATING_POINT_SUPPORTED) && defined(PNG_ERROR_TEXT_SUPPORTED) 1417PNG_EXTERN PNG_FUNCTION(void, png_fixed_error, (png_structp png_ptr, 1418 png_const_charp name),PNG_NORETURN); 1419#endif 1420 1421/* Puts 'string' into 'buffer' at buffer[pos], taking care never to overwrite 1422 * the end. Always leaves the buffer nul terminated. Never errors out (and 1423 * there is no error code.) 1424 */ 1425PNG_EXTERN size_t png_safecat(png_charp buffer, size_t bufsize, size_t pos, 1426 png_const_charp string); 1427 1428/* Various internal functions to handle formatted warning messages, currently 1429 * only implemented for warnings. 1430 */ 1431#if defined(PNG_WARNINGS_SUPPORTED) || defined(PNG_TIME_RFC1123_SUPPORTED) 1432/* Utility to dump an unsigned value into a buffer, given a start pointer and 1433 * and end pointer (which should point just *beyond* the end of the buffer!) 1434 * Returns the pointer to the start of the formatted string. This utility only 1435 * does unsigned values. 1436 */ 1437PNG_EXTERN png_charp png_format_number(png_const_charp start, png_charp end, 1438 int format, png_alloc_size_t number); 1439 1440/* Convenience macro that takes an array: */ 1441#define PNG_FORMAT_NUMBER(buffer,format,number) \ 1442 png_format_number(buffer, buffer + (sizeof buffer), format, number) 1443 1444/* Suggested size for a number buffer (enough for 64 bits and a sign!) */ 1445#define PNG_NUMBER_BUFFER_SIZE 24 1446 1447/* These are the integer formats currently supported, the name is formed from 1448 * the standard printf(3) format string. 1449 */ 1450#define PNG_NUMBER_FORMAT_u 1 /* chose unsigned API! */ 1451#define PNG_NUMBER_FORMAT_02u 2 1452#define PNG_NUMBER_FORMAT_d 1 /* chose signed API! */ 1453#define PNG_NUMBER_FORMAT_02d 2 1454#define PNG_NUMBER_FORMAT_x 3 1455#define PNG_NUMBER_FORMAT_02x 4 1456#define PNG_NUMBER_FORMAT_fixed 5 /* choose the signed API */ 1457#endif 1458 1459#ifdef PNG_WARNINGS_SUPPORTED 1460/* New defines and members adding in libpng-1.5.4 */ 1461# define PNG_WARNING_PARAMETER_SIZE 32 1462# define PNG_WARNING_PARAMETER_COUNT 8 1463 1464/* An l-value of this type has to be passed to the APIs below to cache the 1465 * values of the parameters to a formatted warning message. 1466 */ 1467typedef char png_warning_parameters[PNG_WARNING_PARAMETER_COUNT][ 1468 PNG_WARNING_PARAMETER_SIZE]; 1469 1470PNG_EXTERN void png_warning_parameter(png_warning_parameters p, int number, 1471 png_const_charp string); 1472 /* Parameters are limited in size to PNG_WARNING_PARAMETER_SIZE characters, 1473 * including the trailing '\0'. 1474 */ 1475PNG_EXTERN void png_warning_parameter_unsigned(png_warning_parameters p, 1476 int number, int format, png_alloc_size_t value); 1477 /* Use png_alloc_size_t because it is an unsigned type as big as any we 1478 * need to output. Use the following for a signed value. 1479 */ 1480PNG_EXTERN void png_warning_parameter_signed(png_warning_parameters p, 1481 int number, int format, png_int_32 value); 1482 1483PNG_EXTERN void png_formatted_warning(png_structp png_ptr, 1484 png_warning_parameters p, png_const_charp message); 1485 /* 'message' follows the X/Open approach of using @1, @2 to insert 1486 * parameters previously supplied using the above functions. Errors in 1487 * specifying the paramters will simple result in garbage substitutions. 1488 */ 1489#endif 1490 1491/* ASCII to FP interfaces, currently only implemented if sCAL 1492 * support is required. 1493 */ 1494#if defined(PNG_READ_sCAL_SUPPORTED) 1495/* MAX_DIGITS is actually the maximum number of characters in an sCAL 1496 * width or height, derived from the precision (number of significant 1497 * digits - a build time settable option) and assumpitions about the 1498 * maximum ridiculous exponent. 1499 */ 1500#define PNG_sCAL_MAX_DIGITS (PNG_sCAL_PRECISION+1/*.*/+1/*E*/+10/*exponent*/) 1501 1502#ifdef PNG_FLOATING_POINT_SUPPORTED 1503PNG_EXTERN void png_ascii_from_fp PNGARG((png_structp png_ptr, png_charp ascii, 1504 png_size_t size, double fp, unsigned int precision)); 1505#endif /* FLOATING_POINT */ 1506 1507#ifdef PNG_FIXED_POINT_SUPPORTED 1508PNG_EXTERN void png_ascii_from_fixed PNGARG((png_structp png_ptr, 1509 png_charp ascii, png_size_t size, png_fixed_point fp)); 1510#endif /* FIXED_POINT */ 1511#endif /* READ_sCAL */ 1512 1513#if defined(PNG_sCAL_SUPPORTED) || defined(PNG_pCAL_SUPPORTED) 1514/* An internal API to validate the format of a floating point number. 1515 * The result is the index of the next character. If the number is 1516 * not valid it will be the index of a character in the supposed number. 1517 * 1518 * The format of a number is defined in the PNG extensions specification 1519 * and this API is strictly conformant to that spec, not anyone elses! 1520 * 1521 * The format as a regular expression is: 1522 * 1523 * [+-]?[0-9]+.?([Ee][+-]?[0-9]+)? 1524 * 1525 * or: 1526 * 1527 * [+-]?.[0-9]+(.[0-9]+)?([Ee][+-]?[0-9]+)? 1528 * 1529 * The complexity is that either integer or fraction must be present and the 1530 * fraction is permitted to have no digits only if the integer is present. 1531 * 1532 * NOTE: The dangling E problem. 1533 * There is a PNG valid floating point number in the following: 1534 * 1535 * PNG floating point numb1.ers are not greedy. 1536 * 1537 * Working this out requires *TWO* character lookahead (because of the 1538 * sign), the parser does not do this - it will fail at the 'r' - this 1539 * doesn't matter for PNG sCAL chunk values, but it requires more care 1540 * if the value were ever to be embedded in something more complex. Use 1541 * ANSI-C strtod if you need the lookahead. 1542 */ 1543/* State table for the parser. */ 1544#define PNG_FP_INTEGER 0 /* before or in integer */ 1545#define PNG_FP_FRACTION 1 /* before or in fraction */ 1546#define PNG_FP_EXPONENT 2 /* before or in exponent */ 1547#define PNG_FP_STATE 3 /* mask for the above */ 1548#define PNG_FP_SAW_SIGN 4 /* Saw +/- in current state */ 1549#define PNG_FP_SAW_DIGIT 8 /* Saw a digit in current state */ 1550#define PNG_FP_SAW_DOT 16 /* Saw a dot in current state */ 1551#define PNG_FP_SAW_E 32 /* Saw an E (or e) in current state */ 1552#define PNG_FP_SAW_ANY 60 /* Saw any of the above 4 */ 1553 1554/* These three values don't affect the parser. They are set but not used. 1555 */ 1556#define PNG_FP_WAS_VALID 64 /* Preceding substring is a valid fp number */ 1557#define PNG_FP_NEGATIVE 128 /* A negative number, including "-0" */ 1558#define PNG_FP_NONZERO 256 /* A non-zero value */ 1559#define PNG_FP_STICKY 448 /* The above three flags */ 1560 1561/* This is available for the caller to store in 'state' if required. Do not 1562 * call the parser after setting it (the parser sometimes clears it.) 1563 */ 1564#define PNG_FP_INVALID 512 /* Available for callers as a distinct value */ 1565 1566/* Result codes for the parser (boolean - true meants ok, false means 1567 * not ok yet.) 1568 */ 1569#define PNG_FP_MAYBE 0 /* The number may be valid in the future */ 1570#define PNG_FP_OK 1 /* The number is valid */ 1571 1572/* Tests on the sticky non-zero and negative flags. To pass these checks 1573 * the state must also indicate that the whole number is valid - this is 1574 * achieved by testing PNG_FP_SAW_DIGIT (see the implementation for why this 1575 * is equivalent to PNG_FP_OK above.) 1576 */ 1577#define PNG_FP_NZ_MASK (PNG_FP_SAW_DIGIT | PNG_FP_NEGATIVE | PNG_FP_NONZERO) 1578 /* NZ_MASK: the string is valid and a non-zero negative value */ 1579#define PNG_FP_Z_MASK (PNG_FP_SAW_DIGIT | PNG_FP_NONZERO) 1580 /* Z MASK: the string is valid and a non-zero value. */ 1581 /* PNG_FP_SAW_DIGIT: the string is valid. */ 1582#define PNG_FP_IS_ZERO(state) (((state) & PNG_FP_Z_MASK) == PNG_FP_SAW_DIGIT) 1583#define PNG_FP_IS_POSITIVE(state) (((state) & PNG_FP_NZ_MASK) == PNG_FP_Z_MASK) 1584#define PNG_FP_IS_NEGATIVE(state) (((state) & PNG_FP_NZ_MASK) == PNG_FP_NZ_MASK) 1585 1586/* The actual parser. This can be called repeatedly, it updates 1587 * the index into the string and the state variable (which must 1588 * be initialzed to 0). It returns a result code, as above. There 1589 * is no point calling the parser any more if it fails to advance to 1590 * the end of the string - it is stuck on an invalid character (or 1591 * terminated by '\0'). 1592 * 1593 * Note that the pointer will consume an E or even an E+ then leave 1594 * a 'maybe' state even though a preceding integer.fraction is valid. 1595 * The PNG_FP_WAS_VALID flag indicates that a preceding substring was 1596 * a valid number. It's possible to recover from this by calling 1597 * the parser again (from the start, with state 0) but with a string 1598 * that omits the last character (i.e. set the size to the index of 1599 * the problem character.) This has not been tested within libpng. 1600 */ 1601PNG_EXTERN int png_check_fp_number PNGARG((png_const_charp string, 1602 png_size_t size, int *statep, png_size_tp whereami)); 1603 1604/* This is the same but it checks a complete string and returns true 1605 * only if it just contains a floating point number. As of 1.5.4 this 1606 * function also returns the state at the end of parsing the number if 1607 * it was valid (otherwise it returns 0.) This can be used for testing 1608 * for negative or zero values using the sticky flag. 1609 */ 1610PNG_EXTERN int png_check_fp_string PNGARG((png_const_charp string, 1611 png_size_t size)); 1612#endif /* pCAL || sCAL */ 1613 1614#if defined(PNG_READ_GAMMA_SUPPORTED) ||\ 1615 defined(PNG_INCH_CONVERSIONS_SUPPORTED) || defined(PNG_READ_pHYs_SUPPORTED) 1616/* Added at libpng version 1.5.0 */ 1617/* This is a utility to provide a*times/div (rounded) and indicate 1618 * if there is an overflow. The result is a boolean - false (0) 1619 * for overflow, true (1) if no overflow, in which case *res 1620 * holds the result. 1621 */ 1622PNG_EXTERN int png_muldiv PNGARG((png_fixed_point_p res, png_fixed_point a, 1623 png_int_32 multiplied_by, png_int_32 divided_by)); 1624#endif 1625 1626#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_INCH_CONVERSIONS_SUPPORTED) 1627/* Same deal, but issue a warning on overflow and return 0. */ 1628PNG_EXTERN png_fixed_point png_muldiv_warn PNGARG((png_structp png_ptr, 1629 png_fixed_point a, png_int_32 multiplied_by, png_int_32 divided_by)); 1630#endif 1631 1632#ifdef PNG_READ_GAMMA_SUPPORTED 1633/* Calculate a reciprocal - used for gamma values. This returns 1634 * 0 if the argument is 0 in order to maintain an undefined value, 1635 * there are no warnings. 1636 */ 1637PNG_EXTERN png_fixed_point png_reciprocal PNGARG((png_fixed_point a)); 1638 1639/* The same but gives a reciprocal of the product of two fixed point 1640 * values. Accuracy is suitable for gamma calculations but this is 1641 * not exact - use png_muldiv for that. 1642 */ 1643PNG_EXTERN png_fixed_point png_reciprocal2 PNGARG((png_fixed_point a, 1644 png_fixed_point b)); 1645#endif 1646 1647#ifdef PNG_READ_GAMMA_SUPPORTED 1648/* Internal fixed point gamma correction. These APIs are called as 1649 * required to convert single values - they don't need to be fast, 1650 * they are not used when processing image pixel values. 1651 * 1652 * While the input is an 'unsigned' value it must actually be the 1653 * correct bit value - 0..255 or 0..65535 as required. 1654 */ 1655PNG_EXTERN png_uint_16 png_gamma_correct PNGARG((png_structp png_ptr, 1656 unsigned int value, png_fixed_point gamma_value)); 1657PNG_EXTERN int png_gamma_significant PNGARG((png_fixed_point gamma_value)); 1658PNG_EXTERN png_uint_16 png_gamma_16bit_correct PNGARG((unsigned int value, 1659 png_fixed_point gamma_value)); 1660PNG_EXTERN png_byte png_gamma_8bit_correct PNGARG((unsigned int value, 1661 png_fixed_point gamma_value)); 1662PNG_EXTERN void png_destroy_gamma_table(png_structp png_ptr); 1663PNG_EXTERN void png_build_gamma_table PNGARG((png_structp png_ptr, 1664 int bit_depth)); 1665#endif 1666 1667/* Maintainer: Put new private prototypes here ^ and in libpngpf.3 */ 1668 1669#include "pngdebug.h" 1670 1671#ifdef __cplusplus 1672} 1673#endif 1674 1675#endif /* PNGPRIV_H */ 1676