/* png.h - header file for PNG reference library * * libpng version 1.5.4beta07 - June 18, 2011 * Copyright (c) 1998-2011 Glenn Randers-Pehrson * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) * * This code is released under the libpng license (See LICENSE, below) * * Authors and maintainers: * libpng versions 0.71, May 1995, through 0.88, January 1996: Guy Schalnat * libpng versions 0.89c, June 1996, through 0.96, May 1997: Andreas Dilger * libpng versions 0.97, January 1998, through 1.5.4beta07 - June 18, 2011: Glenn * See also "Contributing Authors", below. * * Note about libpng version numbers: * * Due to various miscommunications, unforeseen code incompatibilities * and occasional factors outside the authors' control, version numbering * on the library has not always been consistent and straightforward. * The following table summarizes matters since version 0.89c, which was * the first widely used release: * * source png.h png.h shared-lib * version string int version * ------- ------ ----- ---------- * 0.89c "1.0 beta 3" 0.89 89 1.0.89 * 0.90 "1.0 beta 4" 0.90 90 0.90 [should have been 2.0.90] * 0.95 "1.0 beta 5" 0.95 95 0.95 [should have been 2.0.95] * 0.96 "1.0 beta 6" 0.96 96 0.96 [should have been 2.0.96] * 0.97b "1.00.97 beta 7" 1.00.97 97 1.0.1 [should have been 2.0.97] * 0.97c 0.97 97 2.0.97 * 0.98 0.98 98 2.0.98 * 0.99 0.99 98 2.0.99 * 0.99a-m 0.99 99 2.0.99 * 1.00 1.00 100 2.1.0 [100 should be 10000] * 1.0.0 (from here on, the 100 2.1.0 [100 should be 10000] * 1.0.1 png.h string is 10001 2.1.0 * 1.0.1a-e identical to the 10002 from here on, the shared library * 1.0.2 source version) 10002 is 2.V where V is the source code * 1.0.2a-b 10003 version, except as noted. * 1.0.3 10003 * 1.0.3a-d 10004 * 1.0.4 10004 * 1.0.4a-f 10005 * 1.0.5 (+ 2 patches) 10005 * 1.0.5a-d 10006 * 1.0.5e-r 10100 (not source compatible) * 1.0.5s-v 10006 (not binary compatible) * 1.0.6 (+ 3 patches) 10006 (still binary incompatible) * 1.0.6d-f 10007 (still binary incompatible) * 1.0.6g 10007 * 1.0.6h 10007 10.6h (testing xy.z so-numbering) * 1.0.6i 10007 10.6i * 1.0.6j 10007 2.1.0.6j (incompatible with 1.0.0) * 1.0.7beta11-14 DLLNUM 10007 2.1.0.7beta11-14 (binary compatible) * 1.0.7beta15-18 1 10007 2.1.0.7beta15-18 (binary compatible) * 1.0.7rc1-2 1 10007 2.1.0.7rc1-2 (binary compatible) * 1.0.7 1 10007 (still compatible) * 1.0.8beta1-4 1 10008 2.1.0.8beta1-4 * 1.0.8rc1 1 10008 2.1.0.8rc1 * 1.0.8 1 10008 2.1.0.8 * 1.0.9beta1-6 1 10009 2.1.0.9beta1-6 * 1.0.9rc1 1 10009 2.1.0.9rc1 * 1.0.9beta7-10 1 10009 2.1.0.9beta7-10 * 1.0.9rc2 1 10009 2.1.0.9rc2 * 1.0.9 1 10009 2.1.0.9 * 1.0.10beta1 1 10010 2.1.0.10beta1 * 1.0.10rc1 1 10010 2.1.0.10rc1 * 1.0.10 1 10010 2.1.0.10 * 1.0.11beta1-3 1 10011 2.1.0.11beta1-3 * 1.0.11rc1 1 10011 2.1.0.11rc1 * 1.0.11 1 10011 2.1.0.11 * 1.0.12beta1-2 2 10012 2.1.0.12beta1-2 * 1.0.12rc1 2 10012 2.1.0.12rc1 * 1.0.12 2 10012 2.1.0.12 * 1.1.0a-f - 10100 2.1.1.0a-f (branch abandoned) * 1.2.0beta1-2 2 10200 2.1.2.0beta1-2 * 1.2.0beta3-5 3 10200 3.1.2.0beta3-5 * 1.2.0rc1 3 10200 3.1.2.0rc1 * 1.2.0 3 10200 3.1.2.0 * 1.2.1beta1-4 3 10201 3.1.2.1beta1-4 * 1.2.1rc1-2 3 10201 3.1.2.1rc1-2 * 1.2.1 3 10201 3.1.2.1 * 1.2.2beta1-6 12 10202 12.so.0.1.2.2beta1-6 * 1.0.13beta1 10 10013 10.so.0.1.0.13beta1 * 1.0.13rc1 10 10013 10.so.0.1.0.13rc1 * 1.2.2rc1 12 10202 12.so.0.1.2.2rc1 * 1.0.13 10 10013 10.so.0.1.0.13 * 1.2.2 12 10202 12.so.0.1.2.2 * 1.2.3rc1-6 12 10203 12.so.0.1.2.3rc1-6 * 1.2.3 12 10203 12.so.0.1.2.3 * 1.2.4beta1-3 13 10204 12.so.0.1.2.4beta1-3 * 1.0.14rc1 13 10014 10.so.0.1.0.14rc1 * 1.2.4rc1 13 10204 12.so.0.1.2.4rc1 * 1.0.14 10 10014 10.so.0.1.0.14 * 1.2.4 13 10204 12.so.0.1.2.4 * 1.2.5beta1-2 13 10205 12.so.0.1.2.5beta1-2 * 1.0.15rc1-3 10 10015 10.so.0.1.0.15rc1-3 * 1.2.5rc1-3 13 10205 12.so.0.1.2.5rc1-3 * 1.0.15 10 10015 10.so.0.1.0.15 * 1.2.5 13 10205 12.so.0.1.2.5 * 1.2.6beta1-4 13 10206 12.so.0.1.2.6beta1-4 * 1.0.16 10 10016 10.so.0.1.0.16 * 1.2.6 13 10206 12.so.0.1.2.6 * 1.2.7beta1-2 13 10207 12.so.0.1.2.7beta1-2 * 1.0.17rc1 10 10017 12.so.0.1.0.17rc1 * 1.2.7rc1 13 10207 12.so.0.1.2.7rc1 * 1.0.17 10 10017 12.so.0.1.0.17 * 1.2.7 13 10207 12.so.0.1.2.7 * 1.2.8beta1-5 13 10208 12.so.0.1.2.8beta1-5 * 1.0.18rc1-5 10 10018 12.so.0.1.0.18rc1-5 * 1.2.8rc1-5 13 10208 12.so.0.1.2.8rc1-5 * 1.0.18 10 10018 12.so.0.1.0.18 * 1.2.8 13 10208 12.so.0.1.2.8 * 1.2.9beta1-3 13 10209 12.so.0.1.2.9beta1-3 * 1.2.9beta4-11 13 10209 12.so.0.9[.0] * 1.2.9rc1 13 10209 12.so.0.9[.0] * 1.2.9 13 10209 12.so.0.9[.0] * 1.2.10beta1-7 13 10210 12.so.0.10[.0] * 1.2.10rc1-2 13 10210 12.so.0.10[.0] * 1.2.10 13 10210 12.so.0.10[.0] * 1.4.0beta1-5 14 10400 14.so.0.0[.0] * 1.2.11beta1-4 13 10211 12.so.0.11[.0] * 1.4.0beta7-8 14 10400 14.so.0.0[.0] * 1.2.11 13 10211 12.so.0.11[.0] * 1.2.12 13 10212 12.so.0.12[.0] * 1.4.0beta9-14 14 10400 14.so.0.0[.0] * 1.2.13 13 10213 12.so.0.13[.0] * 1.4.0beta15-36 14 10400 14.so.0.0[.0] * 1.4.0beta37-87 14 10400 14.so.14.0[.0] * 1.4.0rc01 14 10400 14.so.14.0[.0] * 1.4.0beta88-109 14 10400 14.so.14.0[.0] * 1.4.0rc02-08 14 10400 14.so.14.0[.0] * 1.4.0 14 10400 14.so.14.0[.0] * 1.4.1beta01-03 14 10401 14.so.14.1[.0] * 1.4.1rc01 14 10401 14.so.14.1[.0] * 1.4.1beta04-12 14 10401 14.so.14.1[.0] * 1.4.1 14 10401 14.so.14.1[.0] * 1.4.2 14 10402 14.so.14.2[.0] * 1.4.3 14 10403 14.so.14.3[.0] * 1.4.4 14 10404 14.so.14.4[.0] * 1.5.0beta01-58 15 10500 15.so.15.0[.0] * 1.5.0rc01-07 15 10500 15.so.15.0[.0] * 1.5.0 15 10500 15.so.15.0[.0] * 1.5.1beta01-11 15 10501 15.so.15.1[.0] * 1.5.1rc01-02 15 10501 15.so.15.1[.0] * 1.5.1 15 10501 15.so.15.1[.0] * 1.5.2beta01-03 15 10502 15.so.15.2[.0] * 1.5.2rc01-03 15 10502 15.so.15.2[.0] * 1.5.2 15 10502 15.so.15.2[.0] * 1.5.3beta01-10 15 10503 15.so.15.3[.0] * 1.5.3rc01-02 15 10503 15.so.15.3[.0] * 1.5.3beta11 15 10503 15.so.15.3[.0] * 1.5.3 [omitted] * 1.5.4beta01-07 15 10504 15.so.15.4[.0] * * Henceforth the source version will match the shared-library major * and minor numbers; the shared-library major version number will be * used for changes in backward compatibility, as it is intended. The * PNG_LIBPNG_VER macro, which is not used within libpng but is available * for applications, is an unsigned integer of the form xyyzz corresponding * to the source version x.y.z (leading zeros in y and z). Beta versions * were given the previous public release number plus a letter, until * version 1.0.6j; from then on they were given the upcoming public * release number plus "betaNN" or "rcN". * * Binary incompatibility exists only when applications make direct access * to the info_ptr or png_ptr members through png.h, and the compiled * application is loaded with a different version of the library. * * DLLNUM will change each time there are forward or backward changes * in binary compatibility (e.g., when a new feature is added). * * See libpng-manual.txt or libpng.3 for more information. The PNG * specification is available as a W3C Recommendation and as an ISO * Specification, # endif /* Need the time information for converting tIME chunks, it * defines struct tm: */ # ifdef PNG_CONVERT_tIME_SUPPORTED /* "time.h" functions are not supported on all operating systems */ # include # endif # endif /* Machine specific configuration. */ # include "pngconf.h" #endif /* * Added at libpng-1.2.8 * * Ref MSDN: Private as priority over Special * VS_FF_PRIVATEBUILD File *was not* built using standard release * procedures. If this value is given, the StringFileInfo block must * contain a PrivateBuild string. * * VS_FF_SPECIALBUILD File *was* built by the original company using * standard release procedures but is a variation of the standard * file of the same version number. If this value is given, the * StringFileInfo block must contain a SpecialBuild string. */ #ifdef PNG_USER_PRIVATEBUILD /* From pnglibconf.h */ # define PNG_LIBPNG_BUILD_TYPE \ (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_PRIVATE) #else # ifdef PNG_LIBPNG_SPECIALBUILD # define PNG_LIBPNG_BUILD_TYPE \ (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_SPECIAL) # else # define PNG_LIBPNG_BUILD_TYPE (PNG_LIBPNG_BUILD_BASE_TYPE) # endif #endif #ifndef PNG_VERSION_INFO_ONLY /* Inhibit C++ name-mangling for libpng functions but not for system calls. */ #ifdef __cplusplus extern "C" { #endif /* __cplusplus */ /* Version information for C files, stored in png.c. This had better match * the version above. */ #define png_libpng_ver png_get_header_ver(NULL) /* This file is arranged in several sections: * * 1. Any configuration options that can be specified by for the application * code when it is built. (Build time configuration is in pnglibconf.h) * 2. Type definitions (base types are defined in pngconf.h), structure * definitions. * 3. Exported library functions. * * The library source code has additional files (principally pngpriv.h) that * allow configuration of the library. */ /* Section 1: run time configuration * See pnglibconf.h for build time configuration * * Run time configuration allows the application to choose between * implementations of certain arithmetic APIs. The default is set * at build time and recorded in pnglibconf.h, but it is safe to * override these (and only these) settings. Note that this won't * change what the library does, only application code, and the * settings can (and probably should) be made on a per-file basis * by setting the #defines before including png.h * * Use macros to read integers from PNG data or use the exported * functions? * PNG_USE_READ_MACROS: use the macros (see below) Note that * the macros evaluate their argument multiple times. * PNG_NO_USE_READ_MACROS: call the relevant library function. * * Use the alternative algorithm for compositing alpha samples that * does not use division? * PNG_READ_COMPOSITE_NODIV_SUPPORTED: use the 'no division' * algorithm. * PNG_NO_READ_COMPOSITE_NODIV: use the 'division' algorithm. * * How to handle benign errors if PNG_ALLOW_BENIGN_ERRORS is * false? * PNG_ALLOW_BENIGN_ERRORS: map calls to the benign error * APIs to png_warning. * Otherwise the calls are mapped to png_error. */ /* Section 2: type definitions, including structures and compile time * constants. * See pngconf.h for base types that vary by machine/system */ /* This triggers a compiler error in png.c, if png.c and png.h * do not agree upon the version number. */ typedef char* png_libpng_version_1_5_4beta07; /* Three color definitions. The order of the red, green, and blue, (and the * exact size) is not important, although the size of the fields need to * be png_byte or png_uint_16 (as defined below). */ typedef struct png_color_struct { png_byte red; png_byte green; png_byte blue; } png_color; typedef png_color FAR * png_colorp; typedef PNG_CONST png_color FAR * png_const_colorp; typedef png_color FAR * FAR * png_colorpp; typedef struct png_color_16_struct { png_byte index; /* used for palette files */ png_uint_16 red; /* for use in red green blue files */ png_uint_16 green; png_uint_16 blue; png_uint_16 gray; /* for use in grayscale files */ } png_color_16; typedef png_color_16 FAR * png_color_16p; typedef PNG_CONST png_color_16 FAR * png_const_color_16p; typedef png_color_16 FAR * FAR * png_color_16pp; typedef struct png_color_8_struct { png_byte red; /* for use in red green blue files */ png_byte green; png_byte blue; png_byte gray; /* for use in grayscale files */ png_byte alpha; /* for alpha channel files */ } png_color_8; typedef png_color_8 FAR * png_color_8p; typedef PNG_CONST png_color_8 FAR * png_const_color_8p; typedef png_color_8 FAR * FAR * png_color_8pp; /* * The following two structures are used for the in-core representation * of sPLT chunks. */ typedef struct png_sPLT_entry_struct { png_uint_16 red; png_uint_16 green; png_uint_16 blue; png_uint_16 alpha; png_uint_16 frequency; } png_sPLT_entry; typedef png_sPLT_entry FAR * png_sPLT_entryp; typedef PNG_CONST png_sPLT_entry FAR * png_const_sPLT_entryp; typedef png_sPLT_entry FAR * FAR * png_sPLT_entrypp; /* When the depth of the sPLT palette is 8 bits, the color and alpha samples * occupy the LSB of their respective members, and the MSB of each member * is zero-filled. The frequency member always occupies the full 16 bits. */ typedef struct png_sPLT_struct { png_charp name; /* palette name */ png_byte depth; /* depth of palette samples */ png_sPLT_entryp entries; /* palette entries */ png_int_32 nentries; /* number of palette entries */ } png_sPLT_t; typedef png_sPLT_t FAR * png_sPLT_tp; typedef PNG_CONST png_sPLT_t FAR * png_const_sPLT_tp; typedef png_sPLT_t FAR * FAR * png_sPLT_tpp; #ifdef PNG_TEXT_SUPPORTED /* png_text holds the contents of a text/ztxt/itxt chunk in a PNG file, * and whether that contents is compressed or not. The "key" field * points to a regular zero-terminated C string. The "text", "lang", and * "lang_key" fields can be regular C strings, empty strings, or NULL pointers. * However, the structure returned by png_get_text() will always contain * regular zero-terminated C strings (possibly empty), never NULL pointers, * so they can be safely used in printf() and other string-handling functions. */ typedef struct png_text_struct { int compression; /* compression value: -1: tEXt, none 0: zTXt, deflate 1: iTXt, none 2: iTXt, deflate */ png_charp key; /* keyword, 1-79 character description of "text" */ png_charp text; /* comment, may be an empty string (ie "") or a NULL pointer */ png_size_t text_length; /* length of the text string */ png_size_t itxt_length; /* length of the itxt string */ png_charp lang; /* language code, 0-79 characters or a NULL pointer */ png_charp lang_key; /* keyword translated UTF-8 string, 0 or more chars or a NULL pointer */ } png_text; typedef png_text FAR * png_textp; typedef PNG_CONST png_text FAR * png_const_textp; typedef png_text FAR * FAR * png_textpp; #endif /* Supported compression types for text in PNG files (tEXt, and zTXt). * The values of the PNG_TEXT_COMPRESSION_ defines should NOT be changed. */ #define PNG_TEXT_COMPRESSION_NONE_WR -3 #define PNG_TEXT_COMPRESSION_zTXt_WR -2 #define PNG_TEXT_COMPRESSION_NONE -1 #define PNG_TEXT_COMPRESSION_zTXt 0 #define PNG_ITXT_COMPRESSION_NONE 1 #define PNG_ITXT_COMPRESSION_zTXt 2 #define PNG_TEXT_COMPRESSION_LAST 3 /* Not a valid value */ /* png_time is a way to hold the time in an machine independent way. * Two conversions are provided, both from time_t and struct tm. There * is no portable way to convert to either of these structures, as far * as I know. If you know of a portable way, send it to me. As a side * note - PNG has always been Year 2000 compliant! */ typedef struct png_time_struct { png_uint_16 year; /* full year, as in, 1995 */ png_byte month; /* month of year, 1 - 12 */ png_byte day; /* day of month, 1 - 31 */ png_byte hour; /* hour of day, 0 - 23 */ png_byte minute; /* minute of hour, 0 - 59 */ png_byte second; /* second of minute, 0 - 60 (for leap seconds) */ } png_time; typedef png_time FAR * png_timep; typedef PNG_CONST png_time FAR * png_const_timep; typedef png_time FAR * FAR * png_timepp; #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED) || \ defined(PNG_HANDLE_AS_UNKNOWN_SUPPORTED) /* png_unknown_chunk is a structure to hold queued chunks for which there is * no specific support. The idea is that we can use this to queue * up private chunks for output even though the library doesn't actually * know about their semantics. */ typedef struct png_unknown_chunk_t { png_byte name[5]; png_byte *data; png_size_t size; /* libpng-using applications should NOT directly modify this byte. */ png_byte location; /* mode of operation at read time */ } png_unknown_chunk; typedef png_unknown_chunk FAR * png_unknown_chunkp; typedef PNG_CONST png_unknown_chunk FAR * png_const_unknown_chunkp; typedef png_unknown_chunk FAR * FAR * png_unknown_chunkpp; #endif /* Values for the unknown chunk location byte */ #define PNG_HAVE_IHDR 0x01 #define PNG_HAVE_PLTE 0x02 #define PNG_AFTER_IDAT 0x08 /* The complete definition of png_info has, as of libpng-1.5.0, * been moved into a separate header file that is not accessible to * applications. Read libpng-manual.txt or libpng.3 for more info. */ typedef struct png_info_def png_info; typedef png_info FAR * png_infop; typedef PNG_CONST png_info FAR * png_const_infop; typedef png_info FAR * FAR * png_infopp; /* Maximum positive integer used in PNG is (2^31)-1 */ #define PNG_UINT_31_MAX ((png_uint_32)0x7fffffffL) #define PNG_UINT_32_MAX ((png_uint_32)(-1)) #define PNG_SIZE_MAX ((png_size_t)(-1)) /* These are constants for fixed point values encoded in the * PNG specification manner (x100000) */ #define PNG_FP_1 100000 #define PNG_FP_HALF 50000 #define PNG_FP_MAX ((png_fixed_point)0x7fffffffL) #define PNG_FP_MIN (-PNG_FP_MAX) /* These describe the color_type field in png_info. */ /* color type masks */ #define PNG_COLOR_MASK_PALETTE 1 #define PNG_COLOR_MASK_COLOR 2 #define PNG_COLOR_MASK_ALPHA 4 /* color types. Note that not all combinations are legal */ #define PNG_COLOR_TYPE_GRAY 0 #define PNG_COLOR_TYPE_PALETTE (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE) #define PNG_COLOR_TYPE_RGB (PNG_COLOR_MASK_COLOR) #define PNG_COLOR_TYPE_RGB_ALPHA (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_ALPHA) #define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA) /* aliases */ #define PNG_COLOR_TYPE_RGBA PNG_COLOR_TYPE_RGB_ALPHA #define PNG_COLOR_TYPE_GA PNG_COLOR_TYPE_GRAY_ALPHA /* This is for compression type. PNG 1.0-1.2 only define the single type. */ #define PNG_COMPRESSION_TYPE_BASE 0 /* Deflate method 8, 32K window */ #define PNG_COMPRESSION_TYPE_DEFAULT PNG_COMPRESSION_TYPE_BASE /* This is for filter type. PNG 1.0-1.2 only define the single type. */ #define PNG_FILTER_TYPE_BASE 0 /* Single row per-byte filtering */ #define PNG_INTRAPIXEL_DIFFERENCING 64 /* Used only in MNG datastreams */ #define PNG_FILTER_TYPE_DEFAULT PNG_FILTER_TYPE_BASE /* These are for the interlacing type. These values should NOT be changed. */ #define PNG_INTERLACE_NONE 0 /* Non-interlaced image */ #define PNG_INTERLACE_ADAM7 1 /* Adam7 interlacing */ #define PNG_INTERLACE_LAST 2 /* Not a valid value */ /* These are for the oFFs chunk. These values should NOT be changed. */ #define PNG_OFFSET_PIXEL 0 /* Offset in pixels */ #define PNG_OFFSET_MICROMETER 1 /* Offset in micrometers (1/10^6 meter) */ #define PNG_OFFSET_LAST 2 /* Not a valid value */ /* These are for the pCAL chunk. These values should NOT be changed. */ #define PNG_EQUATION_LINEAR 0 /* Linear transformation */ #define PNG_EQUATION_BASE_E 1 /* Exponential base e transform */ #define PNG_EQUATION_ARBITRARY 2 /* Arbitrary base exponential transform */ #define PNG_EQUATION_HYPERBOLIC 3 /* Hyperbolic sine transformation */ #define PNG_EQUATION_LAST 4 /* Not a valid value */ /* These are for the sCAL chunk. These values should NOT be changed. */ #define PNG_SCALE_UNKNOWN 0 /* unknown unit (image scale) */ #define PNG_SCALE_METER 1 /* meters per pixel */ #define PNG_SCALE_RADIAN 2 /* radians per pixel */ #define PNG_SCALE_LAST 3 /* Not a valid value */ /* These are for the pHYs chunk. These values should NOT be changed. */ #define PNG_RESOLUTION_UNKNOWN 0 /* pixels/unknown unit (aspect ratio) */ #define PNG_RESOLUTION_METER 1 /* pixels/meter */ #define PNG_RESOLUTION_LAST 2 /* Not a valid value */ /* These are for the sRGB chunk. These values should NOT be changed. */ #define PNG_sRGB_INTENT_PERCEPTUAL 0 #define PNG_sRGB_INTENT_RELATIVE 1 #define PNG_sRGB_INTENT_SATURATION 2 #define PNG_sRGB_INTENT_ABSOLUTE 3 #define PNG_sRGB_INTENT_LAST 4 /* Not a valid value */ /* This is for text chunks */ #define PNG_KEYWORD_MAX_LENGTH 79 /* Maximum number of entries in PLTE/sPLT/tRNS arrays */ #define PNG_MAX_PALETTE_LENGTH 256 /* These determine if an ancillary chunk's data has been successfully read * from the PNG header, or if the application has filled in the corresponding * data in the info_struct to be written into the output file. The values * of the PNG_INFO_ defines should NOT be changed. */ #define PNG_INFO_gAMA 0x0001 #define PNG_INFO_sBIT 0x0002 #define PNG_INFO_cHRM 0x0004 #define PNG_INFO_PLTE 0x0008 #define PNG_INFO_tRNS 0x0010 #define PNG_INFO_bKGD 0x0020 #define PNG_INFO_hIST 0x0040 #define PNG_INFO_pHYs 0x0080 #define PNG_INFO_oFFs 0x0100 #define PNG_INFO_tIME 0x0200 #define PNG_INFO_pCAL 0x0400 #define PNG_INFO_sRGB 0x0800 /* GR-P, 0.96a */ #define PNG_INFO_iCCP 0x1000 /* ESR, 1.0.6 */ #define PNG_INFO_sPLT 0x2000 /* ESR, 1.0.6 */ #define PNG_INFO_sCAL 0x4000 /* ESR, 1.0.6 */ #define PNG_INFO_IDAT 0x8000L /* ESR, 1.0.6 */ /* This is used for the transformation routines, as some of them * change these values for the row. It also should enable using * the routines for other purposes. */ typedef struct png_row_info_struct { png_uint_32 width; /* width of row */ png_size_t rowbytes; /* number of bytes in row */ png_byte color_type; /* color type of row */ png_byte bit_depth; /* bit depth of row */ png_byte channels; /* number of channels (1, 2, 3, or 4) */ png_byte pixel_depth; /* bits per pixel (depth * channels) */ } png_row_info; typedef png_row_info FAR * png_row_infop; typedef png_row_info FAR * FAR * png_row_infopp; /* The complete definition of png_struct has, as of libpng-1.5.0, * been moved into a separate header file that is not accessible to * applications. Read libpng-manual.txt or libpng.3 for more info. */ typedef struct png_struct_def png_struct; typedef PNG_CONST png_struct FAR * png_const_structp; typedef png_struct FAR * png_structp; /* These are the function types for the I/O functions and for the functions * that allow the user to override the default I/O functions with his or her * own. The png_error_ptr type should match that of user-supplied warning * and error functions, while the png_rw_ptr type should match that of the * user read/write data functions. Note that the 'write' function must not * modify the buffer it is passed. The 'read' function, on the other hand, is * expected to return the read data in the buffer. */ typedef PNG_CALLBACK(void, *png_error_ptr, (png_structp, png_const_charp)); typedef PNG_CALLBACK(void, *png_rw_ptr, (png_structp, png_bytep, png_size_t)); typedef PNG_CALLBACK(void, *png_flush_ptr, (png_structp)); typedef PNG_CALLBACK(void, *png_read_status_ptr, (png_structp, png_uint_32, int)); typedef PNG_CALLBACK(void, *png_write_status_ptr, (png_structp, png_uint_32, int)); #ifdef PNG_PROGRESSIVE_READ_SUPPORTED typedef PNG_CALLBACK(void, *png_progressive_info_ptr, (png_structp, png_infop)); typedef PNG_CALLBACK(void, *png_progressive_end_ptr, (png_structp, png_infop)); /* The following callback receives png_uint_32 row_number, int pass for the * png_bytep data of the row. When transforming an interlaced image the * row number is the row number within the sub-image of the interlace pass, so * the value will increase to the height of the sub-image (not the full image) * then reset to 0 for the next pass. * * Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to * find the output pixel (x,y) given an interlaced sub-image pixel * (row,col,pass). (See below for these macros.) */ typedef PNG_CALLBACK(void, *png_progressive_row_ptr, (png_structp, png_bytep, png_uint_32, int)); #endif #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \ defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) typedef PNG_CALLBACK(void, *png_user_transform_ptr, (png_structp, png_row_infop, png_bytep)); #endif #ifdef PNG_USER_CHUNKS_SUPPORTED typedef PNG_CALLBACK(int, *png_user_chunk_ptr, (png_structp, png_unknown_chunkp)); #endif #ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED typedef PNG_CALLBACK(void, *png_unknown_chunk_ptr, (png_structp)); #endif #ifdef PNG_SETJMP_SUPPORTED /* This must match the function definition in , and the application * must include this before png.h to obtain the definition of jmp_buf. The * function is required to be PNG_NORETURN, but this is not checked. If the * function does return the application will crash via an abort() or similar * system level call. * * If you get a warning here while building the library you may need to make * changes to ensure that pnglibconf.h records the calling convention used by * your compiler. This may be very difficult - try using a different compiler * to build the library! */ PNG_FUNCTION(void, (PNGCAPI *png_longjmp_ptr), PNGARG((jmp_buf, int)), typedef); #endif /* Transform masks for the high-level interface */ #define PNG_TRANSFORM_IDENTITY 0x0000 /* read and write */ #define PNG_TRANSFORM_STRIP_16 0x0001 /* read only */ #define PNG_TRANSFORM_STRIP_ALPHA 0x0002 /* read only */ #define PNG_TRANSFORM_PACKING 0x0004 /* read and write */ #define PNG_TRANSFORM_PACKSWAP 0x0008 /* read and write */ #define PNG_TRANSFORM_EXPAND 0x0010 /* read only */ #define PNG_TRANSFORM_INVERT_MONO 0x0020 /* read and write */ #define PNG_TRANSFORM_SHIFT 0x0040 /* read and write */ #define PNG_TRANSFORM_BGR 0x0080 /* read and write */ #define PNG_TRANSFORM_SWAP_ALPHA 0x0100 /* read and write */ #define PNG_TRANSFORM_SWAP_ENDIAN 0x0200 /* read and write */ #define PNG_TRANSFORM_INVERT_ALPHA 0x0400 /* read and write */ #define PNG_TRANSFORM_STRIP_FILLER 0x0800 /* write only */ /* Added to libpng-1.2.34 */ #define PNG_TRANSFORM_STRIP_FILLER_BEFORE PNG_TRANSFORM_STRIP_FILLER #define PNG_TRANSFORM_STRIP_FILLER_AFTER 0x1000 /* write only */ /* Added to libpng-1.4.0 */ #define PNG_TRANSFORM_GRAY_TO_RGB 0x2000 /* read only */ /* Added to libpng-1.5.4 */ #define PNG_TRANSFORM_EXPAND_16 0x4000 /* read only */ #define PNG_TRANSFORM_SCALE_16 0x8000 /* read only */ /* Flags for MNG supported features */ #define PNG_FLAG_MNG_EMPTY_PLTE 0x01 #define PNG_FLAG_MNG_FILTER_64 0x04 #define PNG_ALL_MNG_FEATURES 0x05 /* NOTE: prior to 1.5 these functions had no 'API' style declaration, * this allowed the zlib default functions to be used on Windows * platforms. In 1.5 the zlib default malloc (which just calls malloc and * ignores the first argument) should be completely compatible with the * following. */ typedef PNG_CALLBACK(png_voidp, *png_malloc_ptr, (png_structp, png_alloc_size_t)); typedef PNG_CALLBACK(void, *png_free_ptr, (png_structp, png_voidp)); typedef png_struct FAR * FAR * png_structpp; /* Section 3: exported functions * Here are the function definitions most commonly used. This is not * the place to find out how to use libpng. See libpng-manual.txt for the * full explanation, see example.c for the summary. This just provides * a simple one line description of the use of each function. * * The PNG_EXPORT() and PNG_EXPORTA() macros used below are defined in * pngconf.h and in the *.dfn files in the scripts directory. * * PNG_EXPORT(ordinal, type, name, (args)); * * ordinal: ordinal that is used while building * *.def files. The ordinal value is only * relevant when preprocessing png.h with * the *.dfn files for building symbol table * entries, and are removed by pngconf.h. * type: return type of the function * name: function name * args: function arguments, with types * * When we wish to append attributes to a function prototype we use * the PNG_EXPORTA() macro instead. * * PNG_EXPORTA(ordinal, type, name, (args), attributes); * * ordinal, type, name, and args: same as in PNG_EXPORT(). * attributes: function attributes */ /* Returns the version number of the library */ PNG_EXPORT(1, png_uint_32, png_access_version_number, (void)); /* Tell lib we have already handled the first magic bytes. * Handling more than 8 bytes from the beginning of the file is an error. */ PNG_EXPORT(2, void, png_set_sig_bytes, (png_structp png_ptr, int num_bytes)); /* Check sig[start] through sig[start + num_to_check - 1] to see if it's a * PNG file. Returns zero if the supplied bytes match the 8-byte PNG * signature, and non-zero otherwise. Having num_to_check == 0 or * start > 7 will always fail (ie return non-zero). */ PNG_EXPORT(3, int, png_sig_cmp, (png_const_bytep sig, png_size_t start, png_size_t num_to_check)); /* Simple signature checking function. This is the same as calling * png_check_sig(sig, n) := !png_sig_cmp(sig, 0, n). */ #define png_check_sig(sig, n) !png_sig_cmp((sig), 0, (n)) /* Allocate and initialize png_ptr struct for reading, and any other memory. */ PNG_EXPORTA(4, png_structp, png_create_read_struct, (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warn_fn), PNG_ALLOCATED); /* Allocate and initialize png_ptr struct for writing, and any other memory */ PNG_EXPORTA(5, png_structp, png_create_write_struct, (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warn_fn), PNG_ALLOCATED); PNG_EXPORT(6, png_size_t, png_get_compression_buffer_size, (png_const_structp png_ptr)); PNG_EXPORT(7, void, png_set_compression_buffer_size, (png_structp png_ptr, png_size_t size)); /* Moved from pngconf.h in 1.4.0 and modified to ensure setjmp/longjmp * match up. */ #ifdef PNG_SETJMP_SUPPORTED /* This function returns the jmp_buf built in to *png_ptr. It must be * supplied with an appropriate 'longjmp' function to use on that jmp_buf * unless the default error function is overridden in which case NULL is * acceptable. The size of the jmp_buf is checked against the actual size * allocated by the library - the call will return NULL on a mismatch * indicating an ABI mismatch. */ PNG_EXPORT(8, jmp_buf*, png_set_longjmp_fn, (png_structp png_ptr, png_longjmp_ptr longjmp_fn, size_t jmp_buf_size)); # define png_jmpbuf(png_ptr) \ (*png_set_longjmp_fn((png_ptr), longjmp, sizeof (jmp_buf))) #else # define png_jmpbuf(png_ptr) \ (LIBPNG_WAS_COMPILED_WITH__PNG_NO_SETJMP) #endif /* This function should be used by libpng applications in place of * longjmp(png_ptr->jmpbuf, val). If longjmp_fn() has been set, it * will use it; otherwise it will call PNG_ABORT(). This function was * added in libpng-1.5.0. */ PNG_EXPORTA(9, void, png_longjmp, (png_structp png_ptr, int val), PNG_NORETURN); #ifdef PNG_READ_SUPPORTED /* Reset the compression stream */ PNG_EXPORT(10, int, png_reset_zstream, (png_structp png_ptr)); #endif /* New functions added in libpng-1.0.2 (not enabled by default until 1.2.0) */ #ifdef PNG_USER_MEM_SUPPORTED PNG_EXPORTA(11, png_structp, png_create_read_struct_2, (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn), PNG_ALLOCATED); PNG_EXPORTA(12, png_structp, png_create_write_struct_2, (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn), PNG_ALLOCATED); #endif /* Write the PNG file signature. */ PNG_EXPORT(13, void, png_write_sig, (png_structp png_ptr)); /* Write a PNG chunk - size, type, (optional) data, CRC. */ PNG_EXPORT(14, void, png_write_chunk, (png_structp png_ptr, png_const_bytep chunk_name, png_const_bytep data, png_size_t length)); /* Write the start of a PNG chunk - length and chunk name. */ PNG_EXPORT(15, void, png_write_chunk_start, (png_structp png_ptr, png_const_bytep chunk_name, png_uint_32 length)); /* Write the data of a PNG chunk started with png_write_chunk_start(). */ PNG_EXPORT(16, void, png_write_chunk_data, (png_structp png_ptr, png_const_bytep data, png_size_t length)); /* Finish a chunk started with png_write_chunk_start() (includes CRC). */ PNG_EXPORT(17, void, png_write_chunk_end, (png_structp png_ptr)); /* Allocate and initialize the info structure */ PNG_EXPORTA(18, png_infop, png_create_info_struct, (png_structp png_ptr), PNG_ALLOCATED); PNG_EXPORT(19, void, png_info_init_3, (png_infopp info_ptr, png_size_t png_info_struct_size)); /* Writes all the PNG information before the image. */ PNG_EXPORT(20, void, png_write_info_before_PLTE, (png_structp png_ptr, png_infop info_ptr)); PNG_EXPORT(21, void, png_write_info, (png_structp png_ptr, png_infop info_ptr)); #ifdef PNG_SEQUENTIAL_READ_SUPPORTED /* Read the information before the actual image data. */ PNG_EXPORT(22, void, png_read_info, (png_structp png_ptr, png_infop info_ptr)); #endif #ifdef PNG_TIME_RFC1123_SUPPORTED PNG_EXPORT(23, png_const_charp, png_convert_to_rfc1123, (png_structp png_ptr, png_const_timep ptime)); #endif #ifdef PNG_CONVERT_tIME_SUPPORTED /* Convert from a struct tm to png_time */ PNG_EXPORT(24, void, png_convert_from_struct_tm, (png_timep ptime, PNG_CONST struct tm FAR * ttime)); /* Convert from time_t to png_time. Uses gmtime() */ PNG_EXPORT(25, void, png_convert_from_time_t, (png_timep ptime, time_t ttime)); #endif /* PNG_CONVERT_tIME_SUPPORTED */ #ifdef PNG_READ_EXPAND_SUPPORTED /* Expand data to 24-bit RGB, or 8-bit grayscale, with alpha if available. */ PNG_EXPORT(26, void, png_set_expand, (png_structp png_ptr)); PNG_EXPORT(27, void, png_set_expand_gray_1_2_4_to_8, (png_structp png_ptr)); PNG_EXPORT(28, void, png_set_palette_to_rgb, (png_structp png_ptr)); PNG_EXPORT(29, void, png_set_tRNS_to_alpha, (png_structp png_ptr)); #endif #ifdef PNG_READ_EXPAND_16_SUPPORTED /* Expand to 16-bit channels, forces conversion of palette to RGB and expansion * of a tRNS chunk if present. */ PNG_EXPORT(221, void, png_set_expand_16, (png_structp png_ptr)); #endif #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED) /* Use blue, green, red order for pixels. */ PNG_EXPORT(30, void, png_set_bgr, (png_structp png_ptr)); #endif #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED /* Expand the grayscale to 24-bit RGB if necessary. */ PNG_EXPORT(31, void, png_set_gray_to_rgb, (png_structp png_ptr)); #endif #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED /* Reduce RGB to grayscale. */ PNG_FP_EXPORT(32, void, png_set_rgb_to_gray, (png_structp png_ptr, int error_action, double red, double green)); PNG_FIXED_EXPORT(33, void, png_set_rgb_to_gray_fixed, (png_structp png_ptr, int error_action, png_fixed_point red, png_fixed_point green)); PNG_EXPORT(34, png_byte, png_get_rgb_to_gray_status, (png_const_structp png_ptr)); #endif #ifdef PNG_BUILD_GRAYSCALE_PALETTE_SUPPORTED PNG_EXPORT(35, void, png_build_grayscale_palette, (int bit_depth, png_colorp palette)); #endif #ifdef PNG_READ_ALPHA_MODE_SUPPORTED /* How the alpha channel is interpreted - this affects how the color channels of * a PNG file are returned when an alpha channel, or tRNS chunk in a palette * file, is present. * * This has no effect on the way pixels are written into a PNG output * datastream. The color samples in a PNG datastream are never premultiplied * with the alpha samples. * * The default is to return data according to the PNG specification: the alpha * channel is a linear measure of the contribution of the pixel to the * corresponding composited pixel. The gamma encoded color channels must be * scaled according to the contribution and to do this it is necessary to undo * the encoding, scale the color values, perform the composition and reencode * the values. This is the 'PNG' mode. * * The alternative is to 'associate' the alpha with the color information by * storing color channel values that have been scaled by the alpha. The * advantage is that the color channels can be resampled (the image can be * scaled) in this form. The disadvantage is that normal practice is to store * linear, not (gamma) encoded, values and this requires 16-bit channels for * still images rather than the 8-bit channels that are just about sufficient if * gamma encoding is used. In addition all non-transparent pixel values, * including completely opaque ones, must be gamma encoded to produce the final * image. This is the 'STANDARD', 'ASSOCIATED' or 'PREMULTIPLIED' mode (the * latter being the two common names for associated alpha color channels.) * * Since it is not necessary to perform arithmetic on opaque color values so * long as they are not to be resampled and are in the final color space it is * possible to optimize the handling of alpha by storing the opaque pixels in * the PNG format (adjusted for the output color space) while storing partially * opaque pixels in the standard, linear, format. The accuracy required for * standard alpha composition is relatively low, because the pixels are * isolated, therefore typically the accuracy loss in storing 8-bit linear * values is acceptable. (This is not true if the alpha channel is used to * simulate transparency over large areas - use 16 bits or the PNG mode in * this case!) This is the 'OPTIMIZED' mode. For this mode a pixel is * treated as opaque only if the alpha value is equal to the maximum value. * * The final choice is to gamma encode the alpha channel as well. This is * broken because, in practice, no implementation that uses this choice * correctly undoes the encoding before handling alpha composition. Use this * choice only if other serious errors in the software or hardware you use * mandate it; the typical serious error is for dark halos to appear around * opaque areas of the composited PNG image because of arithmetic overflow. * * The API function png_set_alpha_mode specifies which of these choices to use * with an enumerated 'mode' value and the gamma of the required output: */ #define PNG_ALPHA_PNG 0 /* according to the PNG standard */ #define PNG_ALPHA_STANDARD 1 /* according to Porter/Duff */ #define PNG_ALPHA_ASSOCIATED 1 /* as above; this is the normal practice */ #define PNG_ALPHA_PREMULTIPLIED 1 /* as above */ #define PNG_ALPHA_OPTIMIZED 2 /* 'PNG' for opaque pixels, else 'STANDARD' */ #define PNG_ALPHA_BROKEN 3 /* the alpha channel is gamma encoded */ PNG_FP_EXPORT(227, void, png_set_alpha_mode, (png_structp png_ptr, int mode, double output_gamma)); PNG_FIXED_EXPORT(228, void, png_set_alpha_mode_fixed, (png_structp png_ptr, int mode, png_fixed_point output_gamma)); #endif #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_ALPHA_MODE_SUPPORTED) /* The output_gamma value is a screen gamma in libpng terminology: it expresses * how to decode the output values, not how they are encoded. The values used * correspond to the normal numbers used to describe the overall gamma of a * computer display system; for example 2.2 for an sRGB conformant system. The * values are scaled by 100000 in the _fixed version of the API (so 220000 for * sRGB.) * * The inverse of the value is always used to provide a default for the PNG file * encoding if it has no gAMA chunk and if png_set_gamma() has not been called * to override the PNG gamma information. * * When the ALPHA_OPTIMIZED mode is selected the output gamma is used to encode * opaque pixels however pixels with lower alpha values are not encoded, * regardless of the output gamma setting. * * When the standard Porter Duff handling is requested with mode 1 the output * encoding is set to be linear and the output_gamma value is only relevant * as a default for input data that has no gamma information. The linear output * encoding will be overridden if png_set_gamma() is called - the results may be * highly unexpected! * * The following numbers are derived from the sRGB standard and the research * behind it. sRGB is defined to be approximated by a PNG gAMA chunk value of * 0.45455 (1/2.2) for PNG. The value implicitly includes any viewing * correction required to take account of any differences in the color * environment of the original scene and the intended display environment; the * value expresses how to *decode* the image for display, not how the original * data was *encoded*. * * sRGB provides a peg for the PNG standard by defining a viewing environment. * sRGB itself, and earlier TV standards, actually use a more complex transform * (a linear portion then a gamma 2.4 power law) than PNG can express. (PNG is * limited to simple power laws.) By saying that an image for direct display on * an sRGB conformant system should be stored with a gAMA chunk value of 45455 * (11.3.3.2 and 11.3.3.5 of the ISO PNG specification) the PNG specification * makes it possible to derive values for other display systems and * environments. * * The Mac value is deduced from the sRGB based on an assumption that the actual * extra viewing correction used in early Mac display systems was implemented as * a power 1.45 lookup table. * * Any system where a programmable lookup table is used or where the behavior of * the final display device characteristics can be changed requires system * specific code to obtain the current characteristic. However this can be * difficult and most PNG gamma correction only requires an approximate value. * * By default, if png_set_alpha_mode() is not called, libpng assumes that all * values are unencoded, linear, values and that the output device also has a * linear characteristic. This is only very rarely correct - it is invariably * better to call png_set_alpha_mode() with PNG_DEFAULT_sRGB than rely on the * default if you don't know what the right answer is! * * The special value PNG_GAMMA_MAC_18 indicates an older Mac system (pre Mac OS * 10.6) which used a correction table to implement a somewhat lower gamma on an * otherwise sRGB system. * * Both these values are reserved (not simple gamma values) in order to allow * more precise correction internally in the future. * * NOTE: the following values can be passed to either the fixed or floating * point APIs, but the floating point API will also accept floating point * values. */ #define PNG_DEFAULT_sRGB -1 /* sRGB gamma and color space */ #define PNG_GAMMA_MAC_18 -2 /* Old Mac '1.8' gamma and color space */ #define PNG_GAMMA_sRGB 220000 /* Television standards--matches sRGB gamma */ #define PNG_GAMMA_LINEAR PNG_FP_1 /* Linear */ #endif /* The following are examples of calls to png_set_alpha_mode to achieve the * required overall gamma correction and, where necessary, alpha * premultiplication. * * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB); * This is the default libpng handling of the alpha channel - it is not * pre-multiplied into the color components. In addition the call states * that the output is for a sRGB system and causes all PNG files without gAMA * chunks to be assumed to be encoded using sRGB. * * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC); * In this case the output is assumed to be something like an sRGB conformant * display preceeded by a power-law lookup table of power 1.45. This is how * early Mac systems behaved. * * png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_GAMMA_LINEAR); * This is the classic Jim Blinn approach and will work in academic * environments where everything is done by the book. It has the shortcoming * of assuming that input PNG data with no gamma information is linear - this * is unlikely to be correct unless the PNG files where generated locally. * Most of the time the output precision will be so low as to show * significant banding in dark areas of the image. * * png_set_expand_16(pp); * png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_DEFAULT_sRGB); * This is a somewhat more realistic Jim Blinn inspired approach. PNG files * are assumed to have the sRGB encoding if not marked with a gamma value and * the output is always 16 bits per component. This permits accurate scaling * and processing of the data. If you know that your input PNG files were * generated locally you might need to replace PNG_DEFAULT_sRGB with the * correct value for your system. * * png_set_alpha_mode(pp, PNG_ALPHA_OPTIMIZED, PNG_DEFAULT_sRGB); * If you just need to composite the PNG image onto an existing background * and if you control the code that does this you can use the optimization * setting. In this case you just copy completely opaque pixels to the * output. For pixels that are not completely transparent (you just skip * those) you do the composition math using png_composite or png_composite_16 * below then encode the resultant 8-bit or 16-bit values to match the output * encoding. * * Other cases * If neither the PNG nor the standard linear encoding work for you because * of the software or hardware you use then you have a big problem. The PNG * case will probably result in halos around the image. The linear encoding * will probably result in a washed out, too bright, image (it's actually too * contrasty.) Try the ALPHA_OPTIMIZED mode above - this will probably * substantially reduce the halos. Alternatively try: * * png_set_alpha_mode(pp, PNG_ALPHA_BROKEN, PNG_DEFAULT_sRGB); * This option will also reduce the halos, but there will be slight dark * halos round the opaque parts of the image where the background is light. * In the OPTIMIZED mode the halos will be light halos where the background * is dark. Take your pick - the halos are unavoidable unless you can get * your hardware/software fixed! (The OPTIMIZED approach is slightly * faster.) * * When the default gamma of PNG files doesn't match the output gamma. * If you have PNG files with no gamma information png_set_alpha_mode allows * you to provide a default gamma, but it also sets the ouput gamma to the * matching value. If you know your PNG files have a gamma that doesn't * match the output you can take advantage of the fact that * png_set_alpha_mode always sets the output gamma but only sets the PNG * default if it is not already set: * * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB); * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC); * The first call sets both the default and the output gamma values, the * second call overrides the output gamma without changing the default. This * is easier than achieving the same effect with png_set_gamma. You must use * PNG_ALPHA_PNG for the first call - internal checking in png_set_alpha will * fire if more than one call to png_set_alpha_mode and png_set_background is * made in the same read operation, however multiple calls with PNG_ALPHA_PNG * are ignored. */ #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED PNG_EXPORT(36, void, png_set_strip_alpha, (png_structp png_ptr)); #endif #if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \ defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED) PNG_EXPORT(37, void, png_set_swap_alpha, (png_structp png_ptr)); #endif #if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \ defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED) PNG_EXPORT(38, void, png_set_invert_alpha, (png_structp png_ptr)); #endif #if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED) /* Add a filler byte to 8-bit Gray or 24-bit RGB images. */ PNG_EXPORT(39, void, png_set_filler, (png_structp png_ptr, png_uint_32 filler, int flags)); /* The values of the PNG_FILLER_ defines should NOT be changed */ # define PNG_FILLER_BEFORE 0 # define PNG_FILLER_AFTER 1 /* Add an alpha byte to 8-bit Gray or 24-bit RGB images. */ PNG_EXPORT(40, void, png_set_add_alpha, (png_structp png_ptr, png_uint_32 filler, int flags)); #endif /* PNG_READ_FILLER_SUPPORTED || PNG_WRITE_FILLER_SUPPORTED */ #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED) /* Swap bytes in 16-bit depth files. */ PNG_EXPORT(41, void, png_set_swap, (png_structp png_ptr)); #endif #if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED) /* Use 1 byte per pixel in 1, 2, or 4-bit depth files. */ PNG_EXPORT(42, void, png_set_packing, (png_structp png_ptr)); #endif #if defined(PNG_READ_PACKSWAP_SUPPORTED) || \ defined(PNG_WRITE_PACKSWAP_SUPPORTED) /* Swap packing order of pixels in bytes. */ PNG_EXPORT(43, void, png_set_packswap, (png_structp png_ptr)); #endif #if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED) /* Converts files to legal bit depths. */ PNG_EXPORT(44, void, png_set_shift, (png_structp png_ptr, png_const_color_8p true_bits)); #endif #if defined(PNG_READ_INTERLACING_SUPPORTED) || \ defined(PNG_WRITE_INTERLACING_SUPPORTED) /* Have the code handle the interlacing. Returns the number of passes. * MUST be called before png_read_update_info or png_start_read_image, * otherwise it will not have the desired effect. Note that it is still * necessary to call png_read_row or png_read_rows png_get_image_height * times for each pass. */ PNG_EXPORT(45, int, png_set_interlace_handling, (png_structp png_ptr)); #endif #if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED) /* Invert monochrome files */ PNG_EXPORT(46, void, png_set_invert_mono, (png_structp png_ptr)); #endif #ifdef PNG_READ_BACKGROUND_SUPPORTED /* Handle alpha and tRNS by replacing with a background color. Prior to * libpng-1.5.4 this API must not be called before the PNG file header has been * read. Doing so will result in unexpected behavior and possible warnings or * errors if the PNG file contains a bKGD chunk. */ PNG_FP_EXPORT(47, void, png_set_background, (png_structp png_ptr, png_const_color_16p background_color, int background_gamma_code, int need_expand, double background_gamma)); PNG_FIXED_EXPORT(215, void, png_set_background_fixed, (png_structp png_ptr, png_const_color_16p background_color, int background_gamma_code, int need_expand, png_fixed_point background_gamma)); #endif #ifdef PNG_READ_BACKGROUND_SUPPORTED # define PNG_BACKGROUND_GAMMA_UNKNOWN 0 # define PNG_BACKGROUND_GAMMA_SCREEN 1 # define PNG_BACKGROUND_GAMMA_FILE 2 # define PNG_BACKGROUND_GAMMA_UNIQUE 3 #endif #ifdef PNG_READ_16_TO_8_SUPPORTED # ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED /* Scale a 16-bit depth file down to 8-bit, accurately. */ PNG_EXPORT(229, void, png_set_scale_16, (png_structp png_ptr)); # endif # ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED /* Strip the second byte of information from a 16-bit depth file. */ PNG_EXPORT(48, void, png_set_strip_16, (png_structp png_ptr)); # endif #endif #ifdef PNG_READ_QUANTIZE_SUPPORTED /* Turn on quantizing, and reduce the palette to the number of colors * available. */ PNG_EXPORT(49, void, png_set_quantize, (png_structp png_ptr, png_colorp palette, int num_palette, int maximum_colors, png_const_uint_16p histogram, int full_quantize)); #endif #ifdef PNG_READ_GAMMA_SUPPORTED /* The threshold on gamma processing is configurable but hard-wired into the * library. The following is the floating point variant. */ #define PNG_GAMMA_THRESHOLD (PNG_GAMMA_THRESHOLD_FIXED*.00001) /* Handle gamma correction. Screen_gamma=(display_exponent). * NOTE: this API simply sets the screen and file gamma values. It will * therefore override the value for gamma in a PNG file if it is called after * the file header has been read - use with care - call before reading the PNG * file for best results! * * These routines accept the same gamma values as png_set_alpha_mode (described * above). The PNG_GAMMA_ defines and PNG_DEFAULT_sRGB can be passed to either * API (floating point or fixed.) Notice, however, that the 'file_gamma' value * is the inverse of a 'screen gamma' value. */ PNG_FP_EXPORT(50, void, png_set_gamma, (png_structp png_ptr, double screen_gamma, double override_file_gamma)); PNG_FIXED_EXPORT(208, void, png_set_gamma_fixed, (png_structp png_ptr, png_fixed_point screen_gamma, png_fixed_point override_file_gamma)); #endif #ifdef PNG_WRITE_FLUSH_SUPPORTED /* Set how many lines between output flushes - 0 for no flushing */ PNG_EXPORT(51, void, png_set_flush, (png_structp png_ptr, int nrows)); /* Flush the current PNG output buffer */ PNG_EXPORT(52, void, png_write_flush, (png_structp png_ptr)); #endif /* Optional update palette with requested transformations */ PNG_EXPORT(53, void, png_start_read_image, (png_structp png_ptr)); /* Optional call to update the users info structure */ PNG_EXPORT(54, void, png_read_update_info, (png_structp png_ptr, png_infop info_ptr)); #ifdef PNG_SEQUENTIAL_READ_SUPPORTED /* Read one or more rows of image data. */ PNG_EXPORT(55, void, png_read_rows, (png_structp png_ptr, png_bytepp row, png_bytepp display_row, png_uint_32 num_rows)); #endif #ifdef PNG_SEQUENTIAL_READ_SUPPORTED /* Read a row of data. */ PNG_EXPORT(56, void, png_read_row, (png_structp png_ptr, png_bytep row, png_bytep display_row)); #endif #ifdef PNG_SEQUENTIAL_READ_SUPPORTED /* Read the whole image into memory at once. */ PNG_EXPORT(57, void, png_read_image, (png_structp png_ptr, png_bytepp image)); #endif /* Write a row of image data */ PNG_EXPORT(58, void, png_write_row, (png_structp png_ptr, png_const_bytep row)); /* Write a few rows of image data: (*row) is not written; however, the type * is declared as writeable to maintain compatibility with previous versions * of libpng and to allow the 'display_row' array from read_rows to be passed * unchanged to write_rows. */ PNG_EXPORT(59, void, png_write_rows, (png_structp png_ptr, png_bytepp row, png_uint_32 num_rows)); /* Write the image data */ PNG_EXPORT(60, void, png_write_image, (png_structp png_ptr, png_bytepp image)); /* Write the end of the PNG file. */ PNG_EXPORT(61, void, png_write_end, (png_structp png_ptr, png_infop info_ptr)); #ifdef PNG_SEQUENTIAL_READ_SUPPORTED /* Read the end of the PNG file. */ PNG_EXPORT(62, void, png_read_end, (png_structp png_ptr, png_infop info_ptr)); #endif /* Free any memory associated with the png_info_struct */ PNG_EXPORT(63, void, png_destroy_info_struct, (png_structp png_ptr, png_infopp info_ptr_ptr)); /* Free any memory associated with the png_struct and the png_info_structs */ PNG_EXPORT(64, void, png_destroy_read_struct, (png_structpp png_ptr_ptr, png_infopp info_ptr_ptr, png_infopp end_info_ptr_ptr)); /* Free any memory associated with the png_struct and the png_info_structs */ PNG_EXPORT(65, void, png_destroy_write_struct, (png_structpp png_ptr_ptr, png_infopp info_ptr_ptr)); /* Set the libpng method of handling chunk CRC errors */ PNG_EXPORT(66, void, png_set_crc_action, (png_structp png_ptr, int crit_action, int ancil_action)); /* Values for png_set_crc_action() say how to handle CRC errors in * ancillary and critical chunks, and whether to use the data contained * therein. Note that it is impossible to "discard" data in a critical * chunk. For versions prior to 0.90, the action was always error/quit, * whereas in version 0.90 and later, the action for CRC errors in ancillary * chunks is warn/discard. These values should NOT be changed. * * value action:critical action:ancillary */ #define PNG_CRC_DEFAULT 0 /* error/quit warn/discard data */ #define PNG_CRC_ERROR_QUIT 1 /* error/quit error/quit */ #define PNG_CRC_WARN_DISCARD 2 /* (INVALID) warn/discard data */ #define PNG_CRC_WARN_USE 3 /* warn/use data warn/use data */ #define PNG_CRC_QUIET_USE 4 /* quiet/use data quiet/use data */ #define PNG_CRC_NO_CHANGE 5 /* use current value use current value */ /* These functions give the user control over the scan-line filtering in * libpng and the compression methods used by zlib. These functions are * mainly useful for testing, as the defaults should work with most users. * Those users who are tight on memory or want faster performance at the * expense of compression can modify them. See the compression library * header file (zlib.h) for an explination of the compression functions. */ /* Set the filtering method(s) used by libpng. Currently, the only valid * value for "method" is 0. */ PNG_EXPORT(67, void, png_set_filter, (png_structp png_ptr, int method, int filters)); /* Flags for png_set_filter() to say which filters to use. The flags * are chosen so that they don't conflict with real filter types * below, in case they are supplied instead of the #defined constants. * These values should NOT be changed. */ #define PNG_NO_FILTERS 0x00 #define PNG_FILTER_NONE 0x08 #define PNG_FILTER_SUB 0x10 #define PNG_FILTER_UP 0x20 #define PNG_FILTER_AVG 0x40 #define PNG_FILTER_PAETH 0x80 #define PNG_ALL_FILTERS (PNG_FILTER_NONE | PNG_FILTER_SUB | PNG_FILTER_UP | \ PNG_FILTER_AVG | PNG_FILTER_PAETH) /* Filter values (not flags) - used in pngwrite.c, pngwutil.c for now. * These defines should NOT be changed. */ #define PNG_FILTER_VALUE_NONE 0 #define PNG_FILTER_VALUE_SUB 1 #define PNG_FILTER_VALUE_UP 2 #define PNG_FILTER_VALUE_AVG 3 #define PNG_FILTER_VALUE_PAETH 4 #define PNG_FILTER_VALUE_LAST 5 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* EXPERIMENTAL */ /* The "heuristic_method" is given by one of the PNG_FILTER_HEURISTIC_ * defines, either the default (minimum-sum-of-absolute-differences), or * the experimental method (weighted-minimum-sum-of-absolute-differences). * * Weights are factors >= 1.0, indicating how important it is to keep the * filter type consistent between rows. Larger numbers mean the current * filter is that many times as likely to be the same as the "num_weights" * previous filters. This is cumulative for each previous row with a weight. * There needs to be "num_weights" values in "filter_weights", or it can be * NULL if the weights aren't being specified. Weights have no influence on * the selection of the first row filter. Well chosen weights can (in theory) * improve the compression for a given image. * * Costs are factors >= 1.0 indicating the relative decoding costs of a * filter type. Higher costs indicate more decoding expense, and are * therefore less likely to be selected over a filter with lower computational * costs. There needs to be a value in "filter_costs" for each valid filter * type (given by PNG_FILTER_VALUE_LAST), or it can be NULL if you aren't * setting the costs. Costs try to improve the speed of decompression without * unduly increasing the compressed image size. * * A negative weight or cost indicates the default value is to be used, and * values in the range [0.0, 1.0) indicate the value is to remain unchanged. * The default values for both weights and costs are currently 1.0, but may * change if good general weighting/cost heuristics can be found. If both * the weights and costs are set to 1.0, this degenerates the WEIGHTED method * to the UNWEIGHTED method, but with added encoding time/computation. */ PNG_FP_EXPORT(68, void, png_set_filter_heuristics, (png_structp png_ptr, int heuristic_method, int num_weights, png_const_doublep filter_weights, png_const_doublep filter_costs)); PNG_FIXED_EXPORT(209, void, png_set_filter_heuristics_fixed, (png_structp png_ptr, int heuristic_method, int num_weights, png_const_fixed_point_p filter_weights, png_const_fixed_point_p filter_costs)); #endif /* PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */ /* Heuristic used for row filter selection. These defines should NOT be * changed. */ #define PNG_FILTER_HEURISTIC_DEFAULT 0 /* Currently "UNWEIGHTED" */ #define PNG_FILTER_HEURISTIC_UNWEIGHTED 1 /* Used by libpng < 0.95 */ #define PNG_FILTER_HEURISTIC_WEIGHTED 2 /* Experimental feature */ #define PNG_FILTER_HEURISTIC_LAST 3 /* Not a valid value */ #ifdef PNG_WRITE_SUPPORTED /* Set the library compression level. Currently, valid values range from * 0 - 9, corresponding directly to the zlib compression levels 0 - 9 * (0 - no compression, 9 - "maximal" compression). Note that tests have * shown that zlib compression levels 3-6 usually perform as well as level 9 * for PNG images, and do considerably fewer caclulations. In the future, * these values may not correspond directly to the zlib compression levels. */ PNG_EXPORT(69, void, png_set_compression_level, (png_structp png_ptr, int level)); PNG_EXPORT(70, void, png_set_compression_mem_level, (png_structp png_ptr, int mem_level)); PNG_EXPORT(71, void, png_set_compression_strategy, (png_structp png_ptr, int strategy)); /* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a * smaller value of window_bits if it can do so safely. */ PNG_EXPORT(72, void, png_set_compression_window_bits, (png_structp png_ptr, int window_bits)); PNG_EXPORT(73, void, png_set_compression_method, (png_structp png_ptr, int method)); #endif #ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED /* Also set zlib parameters for compressing non-IDAT chunks */ PNG_EXPORT(222, void, png_set_text_compression_level, (png_structp png_ptr, int level)); PNG_EXPORT(223, void, png_set_text_compression_mem_level, (png_structp png_ptr, int mem_level)); PNG_EXPORT(224, void, png_set_text_compression_strategy, (png_structp png_ptr, int strategy)); /* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a * smaller value of window_bits if it can do so safely. */ PNG_EXPORT(225, void, png_set_text_compression_window_bits, (png_structp png_ptr, int window_bits)); PNG_EXPORT(226, void, png_set_text_compression_method, (png_structp png_ptr, int method)); #endif /* PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED */ /* These next functions are called for input/output, memory, and error * handling. They are in the file pngrio.c, pngwio.c, and pngerror.c, * and call standard C I/O routines such as fread(), fwrite(), and * fprintf(). These functions can be made to use other I/O routines * at run time for those applications that need to handle I/O in a * different manner by calling png_set_???_fn(). See libpng-manual.txt for * more information. */ #ifdef PNG_STDIO_SUPPORTED /* Initialize the input/output for the PNG file to the default functions. */ PNG_EXPORT(74, void, png_init_io, (png_structp png_ptr, png_FILE_p fp)); #endif /* Replace the (error and abort), and warning functions with user * supplied functions. If no messages are to be printed you must still * write and use replacement functions. The replacement error_fn should * still do a longjmp to the last setjmp location if you are using this * method of error handling. If error_fn or warning_fn is NULL, the * default function will be used. */ PNG_EXPORT(75, void, png_set_error_fn, (png_structp png_ptr, png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warning_fn)); /* Return the user pointer associated with the error functions */ PNG_EXPORT(76, png_voidp, png_get_error_ptr, (png_const_structp png_ptr)); /* Replace the default data output functions with a user supplied one(s). * If buffered output is not used, then output_flush_fn can be set to NULL. * If PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile time * output_flush_fn will be ignored (and thus can be NULL). * It is probably a mistake to use NULL for output_flush_fn if * write_data_fn is not also NULL unless you have built libpng with * PNG_WRITE_FLUSH_SUPPORTED undefined, because in this case libpng's * default flush function, which uses the standard *FILE structure, will * be used. */ PNG_EXPORT(77, void, png_set_write_fn, (png_structp png_ptr, png_voidp io_ptr, png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn)); /* Replace the default data input function with a user supplied one. */ PNG_EXPORT(78, void, png_set_read_fn, (png_structp png_ptr, png_voidp io_ptr, png_rw_ptr read_data_fn)); /* Return the user pointer associated with the I/O functions */ PNG_EXPORT(79, png_voidp, png_get_io_ptr, (png_structp png_ptr)); PNG_EXPORT(80, void, png_set_read_status_fn, (png_structp png_ptr, png_read_status_ptr read_row_fn)); PNG_EXPORT(81, void, png_set_write_status_fn, (png_structp png_ptr, png_write_status_ptr write_row_fn)); #ifdef PNG_USER_MEM_SUPPORTED /* Replace the default memory allocation functions with user supplied one(s). */ PNG_EXPORT(82, void, png_set_mem_fn, (png_structp png_ptr, png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn)); /* Return the user pointer associated with the memory functions */ PNG_EXPORT(83, png_voidp, png_get_mem_ptr, (png_const_structp png_ptr)); #endif #ifdef PNG_READ_USER_TRANSFORM_SUPPORTED PNG_EXPORT(84, void, png_set_read_user_transform_fn, (png_structp png_ptr, png_user_transform_ptr read_user_transform_fn)); #endif #ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED PNG_EXPORT(85, void, png_set_write_user_transform_fn, (png_structp png_ptr, png_user_transform_ptr write_user_transform_fn)); #endif #ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED PNG_EXPORT(86, void, png_set_user_transform_info, (png_structp png_ptr, png_voidp user_transform_ptr, int user_transform_depth, int user_transform_channels)); /* Return the user pointer associated with the user transform functions */ PNG_EXPORT(87, png_voidp, png_get_user_transform_ptr, (png_const_structp png_ptr)); #endif #ifdef PNG_USER_TRANSFORM_INFO_SUPPORTED /* Return information about the row currently being processed. Note that these * APIs do not fail but will return unexpected results if called outside a user * transform callback. Also note that when transforming an interlaced image the * row number is the row number within the sub-image of the interlace pass, so * the value will increase to the height of the sub-image (not the full image) * then reset to 0 for the next pass. * * Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to * find the output pixel (x,y) given an interlaced sub-image pixel * (row,col,pass). (See below for these macros.) */ PNG_EXPORT(217, png_uint_32, png_get_current_row_number, (png_const_structp)); PNG_EXPORT(218, png_byte, png_get_current_pass_number, (png_const_structp)); #endif #ifdef PNG_USER_CHUNKS_SUPPORTED PNG_EXPORT(88, void, png_set_read_user_chunk_fn, (png_structp png_ptr, png_voidp user_chunk_ptr, png_user_chunk_ptr read_user_chunk_fn)); PNG_EXPORT(89, png_voidp, png_get_user_chunk_ptr, (png_const_structp png_ptr)); #endif #ifdef PNG_PROGRESSIVE_READ_SUPPORTED /* Sets the function callbacks for the push reader, and a pointer to a * user-defined structure available to the callback functions. */ PNG_EXPORT(90, void, png_set_progressive_read_fn, (png_structp png_ptr, png_voidp progressive_ptr, png_progressive_info_ptr info_fn, png_progressive_row_ptr row_fn, png_progressive_end_ptr end_fn)); /* Returns the user pointer associated with the push read functions */ PNG_EXPORT(91, png_voidp, png_get_progressive_ptr, (png_const_structp png_ptr)); /* Function to be called when data becomes available */ PNG_EXPORT(92, void, png_process_data, (png_structp png_ptr, png_infop info_ptr, png_bytep buffer, png_size_t buffer_size)); /* A function which may be called *only* within png_process_data to stop the * processing of any more data. The function returns the number of bytes * remaining, excluding any that libpng has cached internally. A subsequent * call to png_process_data must supply these bytes again. If the argument * 'save' is set to true the routine will first save all the pending data and * will always return 0. */ PNG_EXPORT(219, png_size_t, png_process_data_pause, (png_structp, int save)); /* A function which may be called *only* outside (after) a call to * png_process_data. It returns the number of bytes of data to skip in the * input. Normally it will return 0, but if it returns a non-zero value the * application must skip than number of bytes of input data and pass the * following data to the next call to png_process_data. */ PNG_EXPORT(220, png_uint_32, png_process_data_skip, (png_structp)); /* Function that combines rows. 'new_row' is a flag that should come from * the callback and be non-NULL if anything needs to be done; the library * stores its own version of the new data internally and ignores the passed * in value. */ PNG_EXPORT(93, void, png_progressive_combine_row, (png_structp png_ptr, png_bytep old_row, png_const_bytep new_row)); #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */ PNG_EXPORTA(94, png_voidp, png_malloc, (png_structp png_ptr, png_alloc_size_t size), PNG_ALLOCATED); /* Added at libpng version 1.4.0 */ PNG_EXPORTA(95, png_voidp, png_calloc, (png_structp png_ptr, png_alloc_size_t size), PNG_ALLOCATED); /* Added at libpng version 1.2.4 */ PNG_EXPORTA(96, png_voidp, png_malloc_warn, (png_structp png_ptr, png_alloc_size_t size), PNG_ALLOCATED); /* Frees a pointer allocated by png_malloc() */ PNG_EXPORT(97, void, png_free, (png_structp png_ptr, png_voidp ptr)); /* Free data that was allocated internally */ PNG_EXPORT(98, void, png_free_data, (png_structp png_ptr, png_infop info_ptr, png_uint_32 free_me, int num)); /* Reassign responsibility for freeing existing data, whether allocated * by libpng or by the application */ PNG_EXPORT(99, void, png_data_freer, (png_structp png_ptr, png_infop info_ptr, int freer, png_uint_32 mask)); /* Assignments for png_data_freer */ #define PNG_DESTROY_WILL_FREE_DATA 1 #define PNG_SET_WILL_FREE_DATA 1 #define PNG_USER_WILL_FREE_DATA 2 /* Flags for png_ptr->free_me and info_ptr->free_me */ #define PNG_FREE_HIST 0x0008 #define PNG_FREE_ICCP 0x0010 #define PNG_FREE_SPLT 0x0020 #define PNG_FREE_ROWS 0x0040 #define PNG_FREE_PCAL 0x0080 #define PNG_FREE_SCAL 0x0100 #define PNG_FREE_UNKN 0x0200 #define PNG_FREE_LIST 0x0400 #define PNG_FREE_PLTE 0x1000 #define PNG_FREE_TRNS 0x2000 #define PNG_FREE_TEXT 0x4000 #define PNG_FREE_ALL 0x7fff #define PNG_FREE_MUL 0x4220 /* PNG_FREE_SPLT|PNG_FREE_TEXT|PNG_FREE_UNKN */ #ifdef PNG_USER_MEM_SUPPORTED PNG_EXPORTA(100, png_voidp, png_malloc_default, (png_structp png_ptr, png_alloc_size_t size), PNG_ALLOCATED); PNG_EXPORT(101, void, png_free_default, (png_structp png_ptr, png_voidp ptr)); #endif #ifdef PNG_ERROR_TEXT_SUPPORTED /* Fatal error in PNG image of libpng - can't continue */ PNG_EXPORTA(102, void, png_error, (png_structp png_ptr, png_const_charp error_message), PNG_NORETURN); /* The same, but the chunk name is prepended to the error string. */ PNG_EXPORTA(103, void, png_chunk_error, (png_structp png_ptr, png_const_charp error_message), PNG_NORETURN); #else /* Fatal error in PNG image of libpng - can't continue */ PNG_EXPORTA(104, void, png_err, (png_structp png_ptr), PNG_NORETURN); #endif #ifdef PNG_WARNINGS_SUPPORTED /* Non-fatal error in libpng. Can continue, but may have a problem. */ PNG_EXPORT(105, void, png_warning, (png_structp png_ptr, png_const_charp warning_message)); /* Non-fatal error in libpng, chunk name is prepended to message. */ PNG_EXPORT(106, void, png_chunk_warning, (png_structp png_ptr, png_const_charp warning_message)); #endif #ifdef PNG_BENIGN_ERRORS_SUPPORTED /* Benign error in libpng. Can continue, but may have a problem. * User can choose whether to handle as a fatal error or as a warning. */ # undef png_benign_error PNG_EXPORT(107, void, png_benign_error, (png_structp png_ptr, png_const_charp warning_message)); /* Same, chunk name is prepended to message. */ # undef png_chunk_benign_error PNG_EXPORT(108, void, png_chunk_benign_error, (png_structp png_ptr, png_const_charp warning_message)); PNG_EXPORT(109, void, png_set_benign_errors, (png_structp png_ptr, int allowed)); #else # ifdef PNG_ALLOW_BENIGN_ERRORS # define png_benign_error png_warning # define png_chunk_benign_error png_chunk_warning # else # define png_benign_error png_error # define png_chunk_benign_error png_chunk_error # endif #endif /* The png_set_ functions are for storing values in the png_info_struct. * Similarly, the png_get_ calls are used to read values from the * png_info_struct, either storing the parameters in the passed variables, or * setting pointers into the png_info_struct where the data is stored. The * png_get_ functions return a non-zero value if the data was available * in info_ptr, or return zero and do not change any of the parameters if the * data was not available. * * These functions should be used instead of directly accessing png_info * to avoid problems with future changes in the size and internal layout of * png_info_struct. */ /* Returns "flag" if chunk data is valid in info_ptr. */ PNG_EXPORT(110, png_uint_32, png_get_valid, (png_const_structp png_ptr, png_const_infop info_ptr, png_uint_32 flag)); /* Returns number of bytes needed to hold a transformed row. */ PNG_EXPORT(111, png_size_t, png_get_rowbytes, (png_const_structp png_ptr, png_const_infop info_ptr)); #ifdef PNG_INFO_IMAGE_SUPPORTED /* Returns row_pointers, which is an array of pointers to scanlines that was * returned from png_read_png(). */ PNG_EXPORT(112, png_bytepp, png_get_rows, (png_const_structp png_ptr, png_const_infop info_ptr)); /* Set row_pointers, which is an array of pointers to scanlines for use * by png_write_png(). */ PNG_EXPORT(113, void, png_set_rows, (png_structp png_ptr, png_infop info_ptr, png_bytepp row_pointers)); #endif /* Returns number of color channels in image. */ PNG_EXPORT(114, png_byte, png_get_channels, (png_const_structp png_ptr, png_const_infop info_ptr)); #ifdef PNG_EASY_ACCESS_SUPPORTED /* Returns image width in pixels. */ PNG_EXPORT(115, png_uint_32, png_get_image_width, (png_const_structp png_ptr, png_const_infop info_ptr)); /* Returns image height in pixels. */ PNG_EXPORT(116, png_uint_32, png_get_image_height, (png_const_structp png_ptr, png_const_infop info_ptr)); /* Returns image bit_depth. */ PNG_EXPORT(117, png_byte, png_get_bit_depth, (png_const_structp png_ptr, png_const_infop info_ptr)); /* Returns image color_type. */ PNG_EXPORT(118, png_byte, png_get_color_type, (png_const_structp png_ptr, png_const_infop info_ptr)); /* Returns image filter_type. */ PNG_EXPORT(119, png_byte, png_get_filter_type, (png_const_structp png_ptr, png_const_infop info_ptr)); /* Returns image interlace_type. */ PNG_EXPORT(120, png_byte, png_get_interlace_type, (png_const_structp png_ptr, png_const_infop info_ptr)); /* Returns image compression_type. */ PNG_EXPORT(121, png_byte, png_get_compression_type, (png_const_structp png_ptr, png_const_infop info_ptr)); /* Returns image resolution in pixels per meter, from pHYs chunk data. */ PNG_EXPORT(122, png_uint_32, png_get_pixels_per_meter, (png_const_structp png_ptr, png_const_infop info_ptr)); PNG_EXPORT(123, png_uint_32, png_get_x_pixels_per_meter, (png_const_structp png_ptr, png_const_infop info_ptr)); PNG_EXPORT(124, png_uint_32, png_get_y_pixels_per_meter, (png_const_structp png_ptr, png_const_infop info_ptr)); /* Returns pixel aspect ratio, computed from pHYs chunk data. */ PNG_FP_EXPORT(125, float, png_get_pixel_aspect_ratio, (png_const_structp png_ptr, png_const_infop info_ptr)); PNG_FIXED_EXPORT(210, png_fixed_point, png_get_pixel_aspect_ratio_fixed, (png_const_structp png_ptr, png_const_infop info_ptr)); /* Returns image x, y offset in pixels or microns, from oFFs chunk data. */ PNG_EXPORT(126, png_int_32, png_get_x_offset_pixels, (png_const_structp png_ptr, png_const_infop info_ptr)); PNG_EXPORT(127, png_int_32, png_get_y_offset_pixels, (png_const_structp png_ptr, png_const_infop info_ptr)); PNG_EXPORT(128, png_int_32, png_get_x_offset_microns, (png_const_structp png_ptr, png_const_infop info_ptr)); PNG_EXPORT(129, png_int_32, png_get_y_offset_microns, (png_const_structp png_ptr, png_const_infop info_ptr)); #endif /* PNG_EASY_ACCESS_SUPPORTED */ /* Returns pointer to signature string read from PNG header */ PNG_EXPORT(130, png_const_bytep, png_get_signature, (png_const_structp png_ptr, png_infop info_ptr)); #ifdef PNG_bKGD_SUPPORTED PNG_EXPORT(131, png_uint_32, png_get_bKGD, (png_const_structp png_ptr, png_infop info_ptr, png_color_16p *background)); #endif #ifdef PNG_bKGD_SUPPORTED PNG_EXPORT(132, void, png_set_bKGD, (png_structp png_ptr, png_infop info_ptr, png_const_color_16p background)); #endif #ifdef PNG_cHRM_SUPPORTED PNG_FP_EXPORT(133, png_uint_32, png_get_cHRM, (png_const_structp png_ptr, png_const_infop info_ptr, double *white_x, double *white_y, double *red_x, double *red_y, double *green_x, double *green_y, double *blue_x, double *blue_y)); #ifdef PNG_FIXED_POINT_SUPPORTED /* Otherwise not implemented */ PNG_FIXED_EXPORT(134, png_uint_32, png_get_cHRM_fixed, (png_const_structp png_ptr, png_const_infop info_ptr, png_fixed_point *int_white_x, png_fixed_point *int_white_y, png_fixed_point *int_red_x, png_fixed_point *int_red_y, png_fixed_point *int_green_x, png_fixed_point *int_green_y, png_fixed_point *int_blue_x, png_fixed_point *int_blue_y)); #endif #endif #ifdef PNG_cHRM_SUPPORTED PNG_FP_EXPORT(135, void, png_set_cHRM, (png_structp png_ptr, png_infop info_ptr, double white_x, double white_y, double red_x, double red_y, double green_x, double green_y, double blue_x, double blue_y)); PNG_FIXED_EXPORT(136, void, png_set_cHRM_fixed, (png_structp png_ptr, png_infop info_ptr, png_fixed_point int_white_x, png_fixed_point int_white_y, png_fixed_point int_red_x, png_fixed_point int_red_y, png_fixed_point int_green_x, png_fixed_point int_green_y, png_fixed_point int_blue_x, png_fixed_point int_blue_y)); #endif #ifdef PNG_gAMA_SUPPORTED PNG_FP_EXPORT(137, png_uint_32, png_get_gAMA, (png_const_structp png_ptr, png_const_infop info_ptr, double *file_gamma)); PNG_FIXED_EXPORT(138, png_uint_32, png_get_gAMA_fixed, (png_const_structp png_ptr, png_const_infop info_ptr, png_fixed_point *int_file_gamma)); #endif #ifdef PNG_gAMA_SUPPORTED PNG_FP_EXPORT(139, void, png_set_gAMA, (png_structp png_ptr, png_infop info_ptr, double file_gamma)); PNG_FIXED_EXPORT(140, void, png_set_gAMA_fixed, (png_structp png_ptr, png_infop info_ptr, png_fixed_point int_file_gamma)); #endif #ifdef PNG_hIST_SUPPORTED PNG_EXPORT(141, png_uint_32, png_get_hIST, (png_const_structp png_ptr, png_const_infop info_ptr, png_uint_16p *hist)); #endif #ifdef PNG_hIST_SUPPORTED PNG_EXPORT(142, void, png_set_hIST, (png_structp png_ptr, png_infop info_ptr, png_const_uint_16p hist)); #endif PNG_EXPORT(143, png_uint_32, png_get_IHDR, (png_structp png_ptr, png_infop info_ptr, png_uint_32 *width, png_uint_32 *height, int *bit_depth, int *color_type, int *interlace_method, int *compression_method, int *filter_method)); PNG_EXPORT(144, void, png_set_IHDR, (png_structp png_ptr, png_infop info_ptr, png_uint_32 width, png_uint_32 height, int bit_depth, int color_type, int interlace_method, int compression_method, int filter_method)); #ifdef PNG_oFFs_SUPPORTED PNG_EXPORT(145, png_uint_32, png_get_oFFs, (png_const_structp png_ptr, png_const_infop info_ptr, png_int_32 *offset_x, png_int_32 *offset_y, int *unit_type)); #endif #ifdef PNG_oFFs_SUPPORTED PNG_EXPORT(146, void, png_set_oFFs, (png_structp png_ptr, png_infop info_ptr, png_int_32 offset_x, png_int_32 offset_y, int unit_type)); #endif #ifdef PNG_pCAL_SUPPORTED PNG_EXPORT(147, png_uint_32, png_get_pCAL, (png_const_structp png_ptr, png_const_infop info_ptr, png_charp *purpose, png_int_32 *X0, png_int_32 *X1, int *type, int *nparams, png_charp *units, png_charpp *params)); #endif #ifdef PNG_pCAL_SUPPORTED PNG_EXPORT(148, void, png_set_pCAL, (png_structp png_ptr, png_infop info_ptr, png_const_charp purpose, png_int_32 X0, png_int_32 X1, int type, int nparams, png_const_charp units, png_charpp params)); #endif #ifdef PNG_pHYs_SUPPORTED PNG_EXPORT(149, png_uint_32, png_get_pHYs, (png_const_structp png_ptr, png_const_infop info_ptr, png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type)); #endif #ifdef PNG_pHYs_SUPPORTED PNG_EXPORT(150, void, png_set_pHYs, (png_structp png_ptr, png_infop info_ptr, png_uint_32 res_x, png_uint_32 res_y, int unit_type)); #endif PNG_EXPORT(151, png_uint_32, png_get_PLTE, (png_const_structp png_ptr, png_const_infop info_ptr, png_colorp *palette, int *num_palette)); PNG_EXPORT(152, void, png_set_PLTE, (png_structp png_ptr, png_infop info_ptr, png_const_colorp palette, int num_palette)); #ifdef PNG_sBIT_SUPPORTED PNG_EXPORT(153, png_uint_32, png_get_sBIT, (png_const_structp png_ptr, png_infop info_ptr, png_color_8p *sig_bit)); #endif #ifdef PNG_sBIT_SUPPORTED PNG_EXPORT(154, void, png_set_sBIT, (png_structp png_ptr, png_infop info_ptr, png_const_color_8p sig_bit)); #endif #ifdef PNG_sRGB_SUPPORTED PNG_EXPORT(155, png_uint_32, png_get_sRGB, (png_const_structp png_ptr, png_const_infop info_ptr, int *file_srgb_intent)); #endif #ifdef PNG_sRGB_SUPPORTED PNG_EXPORT(156, void, png_set_sRGB, (png_structp png_ptr, png_infop info_ptr, int srgb_intent)); PNG_EXPORT(157, void, png_set_sRGB_gAMA_and_cHRM, (png_structp png_ptr, png_infop info_ptr, int srgb_intent)); #endif #ifdef PNG_iCCP_SUPPORTED PNG_EXPORT(158, png_uint_32, png_get_iCCP, (png_const_structp png_ptr, png_const_infop info_ptr, png_charpp name, int *compression_type, png_bytepp profile, png_uint_32 *proflen)); #endif #ifdef PNG_iCCP_SUPPORTED PNG_EXPORT(159, void, png_set_iCCP, (png_structp png_ptr, png_infop info_ptr, png_const_charp name, int compression_type, png_const_bytep profile, png_uint_32 proflen)); #endif #ifdef PNG_sPLT_SUPPORTED PNG_EXPORT(160, png_uint_32, png_get_sPLT, (png_const_structp png_ptr, png_const_infop info_ptr, png_sPLT_tpp entries)); #endif #ifdef PNG_sPLT_SUPPORTED PNG_EXPORT(161, void, png_set_sPLT, (png_structp png_ptr, png_infop info_ptr, png_const_sPLT_tp entries, int nentries)); #endif #ifdef PNG_TEXT_SUPPORTED /* png_get_text also returns the number of text chunks in *num_text */ PNG_EXPORT(162, png_uint_32, png_get_text, (png_const_structp png_ptr, png_const_infop info_ptr, png_textp *text_ptr, int *num_text)); #endif /* Note while png_set_text() will accept a structure whose text, * language, and translated keywords are NULL pointers, the structure * returned by png_get_text will always contain regular * zero-terminated C strings. They might be empty strings but * they will never be NULL pointers. */ #ifdef PNG_TEXT_SUPPORTED PNG_EXPORT(163, void, png_set_text, (png_structp png_ptr, png_infop info_ptr, png_const_textp text_ptr, int num_text)); #endif #ifdef PNG_tIME_SUPPORTED PNG_EXPORT(164, png_uint_32, png_get_tIME, (png_const_structp png_ptr, png_infop info_ptr, png_timep *mod_time)); #endif #ifdef PNG_tIME_SUPPORTED PNG_EXPORT(165, void, png_set_tIME, (png_structp png_ptr, png_infop info_ptr, png_const_timep mod_time)); #endif #ifdef PNG_tRNS_SUPPORTED PNG_EXPORT(166, png_uint_32, png_get_tRNS, (png_const_structp png_ptr, png_infop info_ptr, png_bytep *trans_alpha, int *num_trans, png_color_16p *trans_color)); #endif #ifdef PNG_tRNS_SUPPORTED PNG_EXPORT(167, void, png_set_tRNS, (png_structp png_ptr, png_infop info_ptr, png_const_bytep trans_alpha, int num_trans, png_const_color_16p trans_color)); #endif #ifdef PNG_sCAL_SUPPORTED PNG_FP_EXPORT(168, png_uint_32, png_get_sCAL, (png_const_structp png_ptr, png_const_infop info_ptr, int *unit, double *width, double *height)); #ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED /* NOTE: this API is currently implemented using floating point arithmetic, * consequently it can only be used on systems with floating point support. * In any case the range of values supported by png_fixed_point is small and it * is highly recommended that png_get_sCAL_s be used instead. */ PNG_FIXED_EXPORT(214, png_uint_32, png_get_sCAL_fixed, (png_structp png_ptr, png_const_infop info_ptr, int *unit, png_fixed_point *width, png_fixed_point *height)); #endif PNG_EXPORT(169, png_uint_32, png_get_sCAL_s, (png_const_structp png_ptr, png_const_infop info_ptr, int *unit, png_charpp swidth, png_charpp sheight)); PNG_FP_EXPORT(170, void, png_set_sCAL, (png_structp png_ptr, png_infop info_ptr, int unit, double width, double height)); PNG_FIXED_EXPORT(213, void, png_set_sCAL_fixed, (png_structp png_ptr, png_infop info_ptr, int unit, png_fixed_point width, png_fixed_point height)); PNG_EXPORT(171, void, png_set_sCAL_s, (png_structp png_ptr, png_infop info_ptr, int unit, png_const_charp swidth, png_const_charp sheight)); #endif /* PNG_sCAL_SUPPORTED */ #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED /* Provide a list of chunks and how they are to be handled, if the built-in handling or default unknown chunk handling is not desired. Any chunks not listed will be handled in the default manner. The IHDR and IEND chunks must not be listed. keep = 0: follow default behaviour = 1: do not keep = 2: keep only if safe-to-copy = 3: keep even if unsafe-to-copy */ PNG_EXPORT(172, void, png_set_keep_unknown_chunks, (png_structp png_ptr, int keep, png_const_bytep chunk_list, int num_chunks)); PNG_EXPORT(173, int, png_handle_as_unknown, (png_structp png_ptr, png_const_bytep chunk_name)); #endif #ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED PNG_EXPORT(174, void, png_set_unknown_chunks, (png_structp png_ptr, png_infop info_ptr, png_const_unknown_chunkp unknowns, int num_unknowns)); PNG_EXPORT(175, void, png_set_unknown_chunk_location, (png_structp png_ptr, png_infop info_ptr, int chunk, int location)); PNG_EXPORT(176, int, png_get_unknown_chunks, (png_const_structp png_ptr, png_const_infop info_ptr, png_unknown_chunkpp entries)); #endif /* Png_free_data() will turn off the "valid" flag for anything it frees. * If you need to turn it off for a chunk that your application has freed, * you can use png_set_invalid(png_ptr, info_ptr, PNG_INFO_CHNK); */ PNG_EXPORT(177, void, png_set_invalid, (png_structp png_ptr, png_infop info_ptr, int mask)); #ifdef PNG_INFO_IMAGE_SUPPORTED /* The "params" pointer is currently not used and is for future expansion. */ PNG_EXPORT(178, void, png_read_png, (png_structp png_ptr, png_infop info_ptr, int transforms, png_voidp params)); PNG_EXPORT(179, void, png_write_png, (png_structp png_ptr, png_infop info_ptr, int transforms, png_voidp params)); #endif PNG_EXPORT(180, png_const_charp, png_get_copyright, (png_const_structp png_ptr)); PNG_EXPORT(181, png_const_charp, png_get_header_ver, (png_const_structp png_ptr)); PNG_EXPORT(182, png_const_charp, png_get_header_version, (png_const_structp png_ptr)); PNG_EXPORT(183, png_const_charp, png_get_libpng_ver, (png_const_structp png_ptr)); #ifdef PNG_MNG_FEATURES_SUPPORTED PNG_EXPORT(184, png_uint_32, png_permit_mng_features, (png_structp png_ptr, png_uint_32 mng_features_permitted)); #endif /* For use in png_set_keep_unknown, added to version 1.2.6 */ #define PNG_HANDLE_CHUNK_AS_DEFAULT 0 #define PNG_HANDLE_CHUNK_NEVER 1 #define PNG_HANDLE_CHUNK_IF_SAFE 2 #define PNG_HANDLE_CHUNK_ALWAYS 3 /* Strip the prepended error numbers ("#nnn ") from error and warning * messages before passing them to the error or warning handler. */ #ifdef PNG_ERROR_NUMBERS_SUPPORTED PNG_EXPORT(185, void, png_set_strip_error_numbers, (png_structp png_ptr, png_uint_32 strip_mode)); #endif /* Added in libpng-1.2.6 */ #ifdef PNG_SET_USER_LIMITS_SUPPORTED PNG_EXPORT(186, void, png_set_user_limits, (png_structp png_ptr, png_uint_32 user_width_max, png_uint_32 user_height_max)); PNG_EXPORT(187, png_uint_32, png_get_user_width_max, (png_const_structp png_ptr)); PNG_EXPORT(188, png_uint_32, png_get_user_height_max, (png_const_structp png_ptr)); /* Added in libpng-1.4.0 */ PNG_EXPORT(189, void, png_set_chunk_cache_max, (png_structp png_ptr, png_uint_32 user_chunk_cache_max)); PNG_EXPORT(190, png_uint_32, png_get_chunk_cache_max, (png_const_structp png_ptr)); /* Added in libpng-1.4.1 */ PNG_EXPORT(191, void, png_set_chunk_malloc_max, (png_structp png_ptr, png_alloc_size_t user_chunk_cache_max)); PNG_EXPORT(192, png_alloc_size_t, png_get_chunk_malloc_max, (png_const_structp png_ptr)); #endif #if defined(PNG_INCH_CONVERSIONS_SUPPORTED) PNG_EXPORT(193, png_uint_32, png_get_pixels_per_inch, (png_const_structp png_ptr, png_const_infop info_ptr)); PNG_EXPORT(194, png_uint_32, png_get_x_pixels_per_inch, (png_const_structp png_ptr, png_const_infop info_ptr)); PNG_EXPORT(195, png_uint_32, png_get_y_pixels_per_inch, (png_const_structp png_ptr, png_const_infop info_ptr)); PNG_FP_EXPORT(196, float, png_get_x_offset_inches, (png_const_structp png_ptr, png_const_infop info_ptr)); #ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */ PNG_FIXED_EXPORT(211, png_fixed_point, png_get_x_offset_inches_fixed, (png_structp png_ptr, png_const_infop info_ptr)); #endif PNG_FP_EXPORT(197, float, png_get_y_offset_inches, (png_const_structp png_ptr, png_const_infop info_ptr)); #ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */ PNG_FIXED_EXPORT(212, png_fixed_point, png_get_y_offset_inches_fixed, (png_structp png_ptr, png_const_infop info_ptr)); #endif # ifdef PNG_pHYs_SUPPORTED PNG_EXPORT(198, png_uint_32, png_get_pHYs_dpi, (png_const_structp png_ptr, png_const_infop info_ptr, png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type)); # endif /* PNG_pHYs_SUPPORTED */ #endif /* PNG_INCH_CONVERSIONS_SUPPORTED */ /* Added in libpng-1.4.0 */ #ifdef PNG_IO_STATE_SUPPORTED PNG_EXPORT(199, png_uint_32, png_get_io_state, (png_structp png_ptr)); PNG_EXPORTA(200, png_const_bytep, png_get_io_chunk_name, (png_structp png_ptr), PNG_DEPRECATED); PNG_EXPORT(216, png_uint_32, png_get_io_chunk_type, (png_const_structp png_ptr)); /* The flags returned by png_get_io_state() are the following: */ # define PNG_IO_NONE 0x0000 /* no I/O at this moment */ # define PNG_IO_READING 0x0001 /* currently reading */ # define PNG_IO_WRITING 0x0002 /* currently writing */ # define PNG_IO_SIGNATURE 0x0010 /* currently at the file signature */ # define PNG_IO_CHUNK_HDR 0x0020 /* currently at the chunk header */ # define PNG_IO_CHUNK_DATA 0x0040 /* currently at the chunk data */ # define PNG_IO_CHUNK_CRC 0x0080 /* currently at the chunk crc */ # define PNG_IO_MASK_OP 0x000f /* current operation: reading/writing */ # define PNG_IO_MASK_LOC 0x00f0 /* current location: sig/hdr/data/crc */ #endif /* ?PNG_IO_STATE_SUPPORTED */ /* Interlace support. The following macros are always defined so that if * libpng interlace handling is turned off the macros may be used to handle * interlaced images within the application. */ #define PNG_INTERLACE_ADAM7_PASSES 7 /* Two macros to return the first row and first column of the original, * full, image which appears in a given pass. 'pass' is in the range 0 * to 6 and the result is in the range 0 to 7. */ #define PNG_PASS_START_ROW(pass) (((1U&~(pass))<<(3-((pass)>>1)))&7) #define PNG_PASS_START_COL(pass) (((1U& (pass))<<(3-(((pass)+1)>>1)))&7) /* Two macros to help evaluate the number of rows or columns in each * pass. This is expressed as a shift - effectively log2 of the number or * rows or columns in each 8x8 tile of the original image. */ #define PNG_PASS_ROW_SHIFT(pass) ((pass)>2?(8-(pass))>>1:3) #define PNG_PASS_COL_SHIFT(pass) ((pass)>1?(7-(pass))>>1:3) /* Hence two macros to determine the number of rows or columns in a given * pass of an image given its height or width. In fact these macros may * return non-zero even though the sub-image is empty, because the other * dimension may be empty for a small image. */ #define PNG_PASS_ROWS(height, pass) (((height)+(((1<>PNG_PASS_ROW_SHIFT(pass)) #define PNG_PASS_COLS(width, pass) (((width)+(((1<>PNG_PASS_COL_SHIFT(pass)) /* For the reader row callbacks (both progressive and sequential) it is * necessary to find the row in the output image given a row in an interlaced * image, so two more macros: */ #define PNG_ROW_FROM_PASS_ROW(yIn, pass) \ (((yIn)<>(((7-(off))-(pass))<<2)) & 0xFU) | \ ((0x01145AF0U>>(((7-(off))-(pass))<<2)) & 0xF0U)) #define PNG_ROW_IN_INTERLACE_PASS(y, pass) \ ((PNG_PASS_MASK(pass,0) >> ((y)&7)) & 1) #define PNG_COL_IN_INTERLACE_PASS(x, pass) \ ((PNG_PASS_MASK(pass,1) >> ((x)&7)) & 1) #ifdef PNG_READ_COMPOSITE_NODIV_SUPPORTED /* With these routines we avoid an integer divide, which will be slower on * most machines. However, it does take more operations than the corresponding * divide method, so it may be slower on a few RISC systems. There are two * shifts (by 8 or 16 bits) and an addition, versus a single integer divide. * * Note that the rounding factors are NOT supposed to be the same! 128 and * 32768 are correct for the NODIV code; 127 and 32767 are correct for the * standard method. * * [Optimized code by Greg Roelofs and Mark Adler...blame us for bugs. :-) ] */ /* fg and bg should be in `gamma 1.0' space; alpha is the opacity */ # define png_composite(composite, fg, alpha, bg) \ { png_uint_16 temp = (png_uint_16)((png_uint_16)(fg) \ * (png_uint_16)(alpha) \ + (png_uint_16)(bg)*(png_uint_16)(255 \ - (png_uint_16)(alpha)) + (png_uint_16)128); \ (composite) = (png_byte)((temp + (temp >> 8)) >> 8); } # define png_composite_16(composite, fg, alpha, bg) \ { png_uint_32 temp = (png_uint_32)((png_uint_32)(fg) \ * (png_uint_32)(alpha) \ + (png_uint_32)(bg)*(png_uint_32)(65535L \ - (png_uint_32)(alpha)) + (png_uint_32)32768L); \ (composite) = (png_uint_16)((temp + (temp >> 16)) >> 16); } #else /* Standard method using integer division */ # define png_composite(composite, fg, alpha, bg) \ (composite) = (png_byte)(((png_uint_16)(fg) * (png_uint_16)(alpha) + \ (png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) + \ (png_uint_16)127) / 255) # define png_composite_16(composite, fg, alpha, bg) \ (composite) = (png_uint_16)(((png_uint_32)(fg) * (png_uint_32)(alpha) + \ (png_uint_32)(bg)*(png_uint_32)(65535L - (png_uint_32)(alpha)) + \ (png_uint_32)32767) / (png_uint_32)65535L) #endif /* PNG_READ_COMPOSITE_NODIV_SUPPORTED */ #ifdef PNG_READ_INT_FUNCTIONS_SUPPORTED PNG_EXPORT(201, png_uint_32, png_get_uint_32, (png_const_bytep buf)); PNG_EXPORT(202, png_uint_16, png_get_uint_16, (png_const_bytep buf)); PNG_EXPORT(203, png_int_32, png_get_int_32, (png_const_bytep buf)); #endif PNG_EXPORT(204, png_uint_32, png_get_uint_31, (png_structp png_ptr, png_const_bytep buf)); /* No png_get_int_16 -- may be added if there's a real need for it. */ /* Place a 32-bit number into a buffer in PNG byte order (big-endian). */ #ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED PNG_EXPORT(205, void, png_save_uint_32, (png_bytep buf, png_uint_32 i)); #endif #ifdef PNG_SAVE_INT_32_SUPPORTED PNG_EXPORT(206, void, png_save_int_32, (png_bytep buf, png_int_32 i)); #endif /* Place a 16-bit number into a buffer in PNG byte order. * The parameter is declared unsigned int, not png_uint_16, * just to avoid potential problems on pre-ANSI C compilers. */ #ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED PNG_EXPORT(207, void, png_save_uint_16, (png_bytep buf, unsigned int i)); /* No png_save_int_16 -- may be added if there's a real need for it. */ #endif #ifdef PNG_USE_READ_MACROS /* Inline macros to do direct reads of bytes from the input buffer. * The png_get_int_32() routine assumes we are using two's complement * format for negative values, which is almost certainly true. */ # define png_get_uint_32(buf) \ (((png_uint_32)(*(buf)) << 24) + \ ((png_uint_32)(*((buf) + 1)) << 16) + \ ((png_uint_32)(*((buf) + 2)) << 8) + \ ((png_uint_32)(*((buf) + 3)))) /* From libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the * function) incorrectly returned a value of type png_uint_32. */ # define png_get_uint_16(buf) \ ((png_uint_16) \ (((unsigned int)(*(buf)) << 8) + \ ((unsigned int)(*((buf) + 1))))) # define png_get_int_32(buf) \ ((png_int_32)((*(buf) & 0x80) \ ? -((png_int_32)((png_get_uint_32(buf) ^ 0xffffffffL) + 1)) \ : (png_int_32)png_get_uint_32(buf))) #endif /* Maintainer: Put new public prototypes here ^, in libpng.3, and project * defs */ /* The last ordinal number (this is the *last* one already used; the next * one to use is one more than this.) Maintainer, remember to add an entry to * scripts/symbols.def as well. */ #ifdef PNG_EXPORT_LAST_ORDINAL PNG_EXPORT_LAST_ORDINAL(229); #endif #ifdef __cplusplus } #endif #endif /* PNG_VERSION_INFO_ONLY */ /* Do not put anything past this line */ #endif /* PNG_H */