/* png.h - header file for PNG reference library

*

* libpng version 1.6.32, August 24, 2017

*

* Copyright (c) 1998-2002,2004,2006-2017 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 0.89, June 1996, through 0.96, May 1997: Andreas Dilger

* libpng versions 0.97, January 1998, through 1.6.32, August 24, 2017:

* Glenn Randers-Pehrson.

*/

/*

* COPYRIGHT NOTICE, DISCLAIMER, and LICENSE:

*

* If you modify libpng you may insert additional notices immediately following

* this sentence.

*

* This code is released under the libpng license.

*

* libpng versions 1.0.7, July 1, 2000 through 1.6.32, August 24, 2017 are

* Copyright (c) 2000-2002, 2004, 2006-2017 Glenn Randers-Pehrson, are

* derived from libpng-1.0.6, and are distributed according to the same

* disclaimer and license as libpng-1.0.6 with the following individuals

* added to the list of Contributing Authors:

*

* Simon-Pierre Cadieux

* Eric S. Raymond

* Mans Rullgard

* Cosmin Truta

* James Yu

* Mandar Sahastrabuddhe

* Google Inc.

* Vadim Barkov

*

* and with the following additions to the disclaimer:

*

* There is no warranty against interference with your enjoyment of the

* library or against infringement. There is no warranty that our

* efforts or the library will fulfill any of your particular purposes

* or needs. This library is provided with all faults, and the entire

* risk of satisfactory quality, performance, accuracy, and effort is with

* the user.

*

* Some files in the "contrib" directory and some configure-generated

* files that are distributed with libpng have other copyright owners and

* are released under other open source licenses.

*

* Copyright (c) 1998-2000 Glenn Randers-Pehrson, are derived from

* libpng-0.96, and are distributed according to the same disclaimer and

* license as libpng-0.96, with the following individuals added to the list

* of Contributing Authors:

*

* Tom Lane

* Glenn Randers-Pehrson

* Willem van Schaik

*

* libpng versions 0.89, June 1996, through 0.96, May 1997, are

* Copyright (c) 1996-1997 Andreas Dilger, are derived from libpng-0.88,

* and are distributed according to the same disclaimer and license as

* libpng-0.88, with the following individuals added to the list of

* Contributing Authors:

*

* John Bowler

* Kevin Bracey

* Sam Bushell

* Magnus Holmgren

* Greg Roelofs

* Tom Tanner

*

* Some files in the "scripts" directory have other copyright owners

* but are released under this license.

*

*

* For the purposes of this copyright and license, "Contributing Authors"

* is defined as the following set of individuals:

*

* Andreas Dilger

* Dave Martindale

* Guy Eric Schalnat

* Paul Schmidt

* Tim Wegner

*

* The PNG Reference Library is supplied "AS IS". The Contributing Authors

* and Group 42, Inc. disclaim all warranties, expressed or implied,

* including, without limitation, the warranties of merchantability and of

* fitness for any purpose. The Contributing Authors and Group 42, Inc.

* assume no liability for direct, indirect, incidental, special, exemplary,

* or consequential damages, which may result from the use of the PNG

* Reference Library, even if advised of the possibility of such damage.

*

* Permission is hereby granted to use, copy, modify, and distribute this

* source code, or portions hereof, for any purpose, without fee, subject

* to the following restrictions:

*

* 2. Altered versions must be plainly marked as such and must not

* be misrepresented as being the original source.

* 3. This Copyright notice may not be removed or altered from any

* source or altered source distribution.

*

* The Contributing Authors and Group 42, Inc. specifically permit, without

* fee, and encourage the use of this source code as a component to

* supporting the PNG file format in commercial products. If you use this

* source code in a product, acknowledgment is not required but would be

* appreciated.

*

* END OF COPYRIGHT NOTICE, DISCLAIMER, and LICENSE.

*

* TRADEMARK:

*

* The name "libpng" has not been registered by the Copyright owner

* as a trademark in any jurisdiction. However, because libpng has

* been distributed and maintained world-wide, continually since 1995,

* the Copyright owner claims "common-law trademark protection" in any

* jurisdiction where common-law trademark is recognized.

*

* OSI CERTIFICATION:

*

* Libpng is OSI Certified Open Source Software. OSI Certified Open Source is

* a certification mark of the Open Source Initiative. OSI has not addressed

* the additional disclaimers inserted at version 1.0.7.

*

* EXPORT CONTROL:

*

* The Copyright owner believes that the Export Control Classification

* Number (ECCN) for libpng is EAR99, which means not subject to export

* controls or International Traffic in Arms Regulations (ITAR) because

* it is open source, publicly available software, that does not contain

* any encryption software. See the EAR, paragraphs 734.3(b)(3) and

* 734.7(b).

*/

/*

* A "png_get_copyright" function is available, for convenient use in "about"

* boxes and the like:

*

*

* Also, the PNG logo (in PNG format, of course) is supplied in the

* files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31).

*/

/*

* The contributing authors would like to thank all those who helped

* with testing, bug fixes, and patience. This wouldn't have been

* possible without all of you.

*

* Thanks to Frank J. T. Wojcik for helping with the documentation.

*/

/* 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)

* ...

* 1.0.19 10 10019 10.so.0.19[.0]

* ...

* 1.2.57 13 10257 12.so.0.57[.0]

* ...

* 1.5.28 15 10527 15.so.15.28[.0]

* ...

* 1.6.32 16 10632 16.so.16.32[.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 "rcNN".

*

* 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.txt or libpng.3 for more information. The PNG specification

* is available as a W3C Recommendation and as an ISO Specification,

* <https://www.w3.org/TR/2003/REC-PNG-20031110/

*/

/*

* Y2K compliance in libpng:

* =========================

*

*

* Since the PNG Development group is an ad-hoc body, we can't make

* an official declaration.

*

* This is your unofficial assurance that libpng from version 0.71 and

* that will hold years up to 65535. The other, which is deprecated,

* holds the date in text format, and will hold years up to 9999.

*

* The integer is

* "png_uint_16 year" in png_time_struct.

*

* "char time_buffer[29]" in png_struct. This is no longer used

* in libpng-1.6.x and will be removed from libpng-1.7.0.

*

* There are seven time-related functions:

* png.c: png_convert_to_rfc_1123_buffer() in png.c

* (formerly png_convert_to_rfc_1123() prior to libpng-1.5.x and

* png_convert_to_rfc_1152() in error prior to libpng-0.98)

* png_convert_from_struct_tm() in pngwrite.c, called in pngwrite.c

* png_convert_from_time_t() in pngwrite.c

* png_get_tIME() in pngget.c

* png_handle_tIME() in pngrutil.c, called in pngread.c

* png_set_tIME() in pngset.c

* png_write_tIME() in pngwutil.c, called in pngwrite.c

*

* All handle dates properly in a Y2K environment. The

* png_convert_from_time_t() function calls gmtime() to convert from system

* clock time, which returns (year - 1900), which we properly convert to

* the full 4-digit year. There is a possibility that libpng applications

* are not passing 4-digit years into the png_convert_to_rfc_1123_buffer()

* function, or that they are incorrectly passing only a 2-digit year

* instead of "year - 1900" into the png_convert_from_struct_tm() function,

* but this is not under our control. The libpng documentation has always

* stated that it works with 4-digit years, and the APIs have been

* documented as such.

*

* The tIME chunk itself is also Y2K compliant. It uses a 2-byte unsigned

* integer to hold the year, and can hold years as large as 65535.

*

* zlib, upon which libpng depends, is also Y2K compliant. It contains

* no date-related code.

*

* Glenn Randers-Pehrson

* libpng maintainer

* PNG Development Group

*/

#ifndef PNG_H

#define PNG_H

* describes how to use libpng, and the file example.c summarizes it

* with some code on which to build. This file is useful for looking

* at the actual function definitions and structure components. If that

* file has been stripped from your copy of libpng, you can find it at

* <http://www.libpng.org/pub/png/libpng-manual.txt>

*

* If you just need to read a PNG file and don't want to read the documentation

* skip to the end of this file and read the section entitled 'simplified API'.

*/

/* Version information for png.h - this should match the version in png.c */

#define PNG_LIBPNG_VER_STRING "1.6.32"

#define PNG_HEADER_VERSION_STRING " libpng version 1.6.32 - August 24, 2017\n"

#define PNG_LIBPNG_VER_SONUM 16

#define PNG_LIBPNG_VER_DLLNUM 16

/* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */

#define PNG_LIBPNG_VER_MAJOR 1

/* This should match the numeric part of the final component of

* PNG_LIBPNG_VER_STRING, omitting any leading zero:

*/

#define PNG_LIBPNG_VER_BUILD 0

/* Release Status */

#define PNG_LIBPNG_BUILD_ALPHA 1

#define PNG_LIBPNG_BUILD_BETA 2

#define PNG_LIBPNG_BUILD_RC 3

#define PNG_LIBPNG_BUILD_STABLE 4

#define PNG_LIBPNG_BUILD_RELEASE_STATUS_MASK 7

/* Release-Specific Flags */

#define PNG_LIBPNG_BUILD_PATCH 8 /* Can be OR'ed with

PNG_LIBPNG_BUILD_STABLE only */

#define PNG_LIBPNG_BUILD_PRIVATE 16 /* Cannot be OR'ed with

PNG_LIBPNG_BUILD_SPECIAL */

#define PNG_LIBPNG_BUILD_SPECIAL 32 /* Cannot be OR'ed with

PNG_LIBPNG_BUILD_PRIVATE */

/* Careful here. At one time, Guy wanted to use 082, but that would be octal.

* We must not include leading zeros.

* Versions 0.7 through 1.0.0 were in the range 0 to 100 here (only

* version 1.0.0 was mis-numbered 100 instead of 10000). From

* version 1.0.1 it's xxyyzz, where x=major, y=minor, z=release

*/

/* Library configuration: these options cannot be changed after

* the library has been built.

*/

#ifndef PNGLCONF_H

/* If pnglibconf.h is missing, you can

* copy scripts/pnglibconf.h.prebuilt to pnglibconf.h

*/

#endif

# 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.

*/

# 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. [omitted]

* 2. Any configuration options that can be specified by for the application

* 4. Exported library functions.

* 5. Simplified API.

* 6. Implementation options.

*

* The library source code has additional files (principally pngpriv.h) that

* allow configuration of the library.

*/

/* Section 1: [omitted] */

/* Section 2: 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.

*/

* 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.

*/

/* Basic control structions. Read libpng-manual.txt or libpng.3 for more info.

*

* png_struct is the cache of information used while reading or writing a single

* PNG file. One of these is always required, although the simplified API

* (below) hides the creation and destruction of it.

*/

typedef struct png_struct_def png_struct;

typedef const png_struct * png_const_structp;

typedef png_struct * png_structp;

typedef png_struct * * png_structpp;

/* png_info contains information read from or to be written to a PNG file. One

* or more of these must exist while reading or creating a PNG file. The

* information is not used by libpng during read but is used to control what

* gets written when a PNG file is created. "png_get_" function calls read

* information during read and "png_set_" functions calls write information

* when creating a PNG.

* 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 * png_infop;

typedef const png_info * png_const_infop;

typedef png_info * * png_infopp;

/* Types with names ending 'p' are pointer types. The corresponding types with

* names ending 'rp' are identical pointer types except that the pointer is

* marked 'restrict', which means that it is the only pointer to the object

* passed to the function. Applications should not use the 'restrict' types;

* it is always valid to pass 'p' to a pointer with a function argument of the

* corresponding 'rp' type. Different compilers have different rules with

* regard to type matching in the presence of 'restrict'. For backward

* compatibility libpng callbacks never have 'restrict' in their parameters and,

* consequentially, writing portable application code is extremely difficult if

* an attempt is made to use 'restrict'.

*/

typedef png_struct * PNG_RESTRICT png_structrp;

typedef const png_struct * PNG_RESTRICT png_const_structrp;

typedef png_info * PNG_RESTRICT png_inforp;

typedef const png_info * PNG_RESTRICT png_const_inforp;

/* 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 * png_colorp;

typedef const png_color * png_const_colorp;

typedef png_color * * 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 * png_color_16p;

typedef const png_color_16 * png_const_color_16p;

typedef png_color_16 * * 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 * png_color_8p;

typedef const png_color_8 * png_const_color_8p;

typedef png_color_8 * * 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 * png_sPLT_entryp;

typedef const png_sPLT_entry * png_const_sPLT_entryp;

typedef png_sPLT_entry * * 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 * png_sPLT_tp;

typedef const png_sPLT_t * png_const_sPLT_tp;

typedef png_sPLT_t * * 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" fields can be a

* regular C string, an empty string, or a NULL pointer.

* However, the structure returned by png_get_text() will always contain

* the "text" field as a regular zero-terminated C string (possibly

* empty), never a NULL pointer, so it can be safely used in printf() and

* other string-handling functions. Note that the "itxt_length", "lang", and

* "lang_key" members of the structure only exist when the library is built

* with iTXt chunk support. Prior to libpng-1.4.0 the library was built by

* default without iTXt support. Also note that when iTXt *is* supported,

* the "lang" and "lang_key" fields contain NULL pointers when the

* "compression" field contains * PNG_TEXT_COMPRESSION_NONE or

* PNG_TEXT_COMPRESSION_zTXt. Note that the "compression value" is not the

* same as what appears in the PNG tEXt/zTXt/iTXt chunk's "compression flag"

* which is always 0 or 1, or its "compression method" which is always 0.

*/

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 * png_textp;

typedef const png_text * png_const_textp;

typedef png_text * * png_textpp;

#endif

/* Supported compression types for text in PNG files (tEXt, and zTXt).

#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 * png_timep;

typedef const png_time * png_const_timep;

typedef png_time * * png_timepp;

#if defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED) ||\

defined(PNG_USER_CHUNKS_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.

*

* The data in the structure is set by libpng on read and used on write.

*/

typedef struct png_unknown_chunk_t

{

png_byte name[5]; /* Textual chunk name with '\0' terminator */

png_byte *data; /* Data, should not be modified on read! */

png_size_t size;

/* On write 'location' must be set using the flag values listed below.

* Notice that on read it is set by libpng however the values stored have

* more bits set than are listed below. Always treat the value as a

* bitmask. On write set only one bit - setting multiple bits may cause the

* chunk to be written in multiple places.

*/

png_byte location; /* mode of operation at read time */

}

png_unknown_chunk;

typedef png_unknown_chunk * png_unknown_chunkp;

typedef const png_unknown_chunk * png_const_unknown_chunkp;

typedef png_unknown_chunk * * png_unknown_chunkpp;

#endif

#define PNG_HAVE_IHDR 0x01

#define PNG_HAVE_PLTE 0x02

#define PNG_AFTER_IDAT 0x08

/* 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_<chunk> defines should NOT be changed.

*/

#define PNG_INFO_gAMA 0x0001U

#define PNG_INFO_sBIT 0x0002U

#define PNG_INFO_cHRM 0x0004U

#define PNG_INFO_PLTE 0x0008U

#define PNG_INFO_tRNS 0x0010U

#define PNG_INFO_bKGD 0x0020U

#define PNG_INFO_hIST 0x0040U

#define PNG_INFO_pHYs 0x0080U

#define PNG_INFO_oFFs 0x0100U

#define PNG_INFO_tIME 0x0200U

#define PNG_INFO_pCAL 0x0400U

#define PNG_INFO_sRGB 0x0800U /* GR-P, 0.96a */

#define PNG_INFO_iCCP 0x1000U /* ESR, 1.0.6 */

#define PNG_INFO_sPLT 0x2000U /* ESR, 1.0.6 */

#define PNG_INFO_sCAL 0x4000U /* ESR, 1.0.6 */

#define PNG_INFO_IDAT 0x8000U /* ESR, 1.0.6 */

#define PNG_INFO_eXIf 0x10000U /* GR-P, 1.6.31 */

/* 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 * png_row_infop;

typedef png_row_info * * png_row_infopp;

/* 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

/* not used anywhere */

/* typedef PNG_CALLBACK(void, *png_unknown_chunk_ptr, (png_structp)); */

#ifdef PNG_SETJMP_SUPPORTED

/* This must match the function definition in <setjmp.h>, 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_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 */

/* 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));

* 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 */

/* Tell lib we have already handled the first <num_bytes> magic bytes.

* Handling more than 8 bytes from the beginning of the file is an error.

*/

/* 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).

*/

/* 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),