pngconf.h - third_party/libpng - Git at Google


 /* pngconf.h - machine configurable file for libpng
  *
  * libpng 1.00
  * For conditions of distribution and use, see copyright notice in png.h
  * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
  * Copyright (c) 1996, 1997 Andreas Dilger
  * Copyright (c) 1998, Glenn Randers-Pehrson
  * March 7, 1998
  */

 /* Any machine specific code is near the front of this file, so if you
  * are configuring libpng for a machine, you may want to read the section
  * starting here down to where it starts to typedef png_color, png_text,
  * and png_info.
  */

 #ifndef PNGCONF_H
 #define PNGCONF_H

 /* This is the size of the compression buffer, and thus the size of
  * an IDAT chunk.  Make this whatever size you feel is best for your
  * machine.  One of these will be allocated per png_struct.  When this
  * is full, it writes the data to the disk, and does some other
  * calculations.  Making this an extremely small size will slow
  * the library down, but you may want to experiment to determine
  * where it becomes significant, if you are concerned with memory
  * usage.  Note that zlib allocates at least 32Kb also.  For readers,
  * this describes the size of the buffer available to read the data in.
  * Unless this gets smaller than the size of a row (compressed),
  * it should not make much difference how big this is.
  */

 #ifndef PNG_ZBUF_SIZE
 #define PNG_ZBUF_SIZE 8192
 #endif

 /* If you are running on a machine where you cannot allocate more
  * than 64K of memory at once, uncomment this.  While libpng will not
  * normally need that much memory in a chunk (unless you load up a very
  * large file), zlib needs to know how big of a chunk it can use, and
  * libpng thus makes sure to check any memory allocation to verify it
  * will fit into memory.
 #define PNG_MAX_MALLOC_64K
  */
 #if defined(MAXSEG_64K) && !defined(PNG_MAX_MALLOC_64K)
 #define PNG_MAX_MALLOC_64K
 #endif

 /* This protects us against compilers which run on a windowing system
  * and thus don't have or would rather us not use the stdio types:
  * stdin, stdout, and stderr.  The only one currently used is stderr
  * in png_error() and png_warning().  #defining PNG_NO_STDIO will
  * prevent these from being compiled and used.
  * #define PNG_NO_STDIO
  */

 #ifndef PNG_NO_STDIO
 #include <stdio.h>
 #endif

 /* This macro protects us against machines that don't have function
  * prototypes (ie K&R style headers).  If your compiler does not handle
  * function prototypes, define this macro and use the included ansi2knr.
  * I've always been able to use _NO_PROTO as the indicator, but you may
  * need to drag the empty declaration out in front of here, or change the
  * ifdef to suit your own needs.
  */
 #ifndef PNGARG

 #ifdef OF /* zlib prototype munger */
 #define PNGARG(arglist) OF(arglist)
 #else

 #ifdef _NO_PROTO
 #define PNGARG(arglist) ()
 #else
 #define PNGARG(arglist) arglist
 #endif /* _NO_PROTO */

 #endif /* OF */

 #endif /* PNGARG */

 /* Try to determine if we are compiling on a Mac.  Note that testing for
  * just __MWERKS__ is not good enough, because the Codewarrior is now used
  * on non-Mac platforms.
  */
 #ifndef MACOS
 #if (defined(__MWERKS__) && defined(macintosh)) || defined(applec) || \
     defined(THINK_C) || defined(__SC__) || defined(TARGET_OS_MAC)
 #define MACOS
 #endif
 #endif

 /* enough people need this for various reasons to include it here */
 #if !defined(MACOS) && !defined(RISCOS)
 #include <sys/types.h>
 #endif

 /* This is an attempt to force a single setjmp behaviour on Linux.  If
  * the X config stuff didn't define _BSD_SOURCE we wouldn't need this.
  */
 #ifdef __linux__
 #ifdef _BSD_SOURCE
 #define _PNG_SAVE_BSD_SOURCE
 #undef _BSD_SOURCE
 #endif
 #ifdef _SETJMP_H
 __png.h__ already includes setjmp.h
 __dont__ include it again
 #endif
 #endif /* __linux__ */

 /* include setjmp.h for error handling */
 #include <setjmp.h>

 #ifdef __linux__
 #ifdef _PNG_SAVE_BSD_SOURCE
 #define _BSD_SOURCE
 #undef _PNG_SAVE_BSD_SOURCE
 #endif
 #endif /* __linux__ */

 #ifdef BSD
 #include <strings.h>
 #else
 #include <string.h>
 #endif

 /* Other defines for things like memory and the like can go here.  */
 #ifdef PNG_INTERNAL
 #include <stdlib.h>

 /* The functions exported by PNG_EXTERN are PNG_INTERNAL functions, which
  * aren't usually used outside the library (as far as I know), so it is
  * debatable if they should be exported at all.  In the future, when it is
  * possible to have run-time registry of chunk-handling functions, some of
  * these will be made available again.
 #define PNG_EXTERN extern
  */
 #define PNG_EXTERN

 /* Other defines specific to compilers can go here.  Try to keep
  * them inside an appropriate ifdef/endif pair for portability.
  */

 #if defined(MACOS)
 /* We need to check that <math.h> hasn't already been included earlier
  * as it seems it doesn't agree with <fp.h>, yet we should really use
  * <fp.h> if possible.
  */
 #if !defined(__MATH_H__) && !defined(__MATH_H) && !defined(__cmath__)
 #include <fp.h>
 #endif
 #else
 #include <math.h>
 #endif

 /* Codewarrior on NT has linking problems without this. */
 #if defined(__MWERKS__) && defined(WIN32)
 #define PNG_ALWAYS_EXTERN
 #endif

 /* For some reason, Borland C++ defines memcmp, etc. in mem.h, not
  * stdlib.h like it should (I think).  Or perhaps this is a C++
  * "feature"?
  */
 #ifdef __TURBOC__
 #include <mem.h>
 #include "alloc.h"
 #endif

 #ifdef _MSC_VER
 #include <malloc.h>
 #endif

 /* This controls how fine the dithering gets.  As this allocates
  * a largish chunk of memory (32K), those who are not as concerned
  * with dithering quality can decrease some or all of these.
  */
 #ifndef PNG_DITHER_RED_BITS
 #define PNG_DITHER_RED_BITS 5
 #endif
 #ifndef PNG_DITHER_GREEN_BITS
 #define PNG_DITHER_GREEN_BITS 5
 #endif
 #ifndef PNG_DITHER_BLUE_BITS
 #define PNG_DITHER_BLUE_BITS 5
 #endif

 /* This controls how fine the gamma correction becomes when you
  * are only interested in 8 bits anyway.  Increasing this value
  * results in more memory being used, and more pow() functions
  * being called to fill in the gamma tables.  Don't set this value
  * less then 8, and even that may not work (I haven't tested it).
  */

 #ifndef PNG_MAX_GAMMA_8
 #define PNG_MAX_GAMMA_8 11
 #endif

 /* This controls how much a difference in gamma we can tolerate before
  * we actually start doing gamma conversion.
  */
 #ifndef PNG_GAMMA_THRESHOLD
 #define PNG_GAMMA_THRESHOLD 0.05
 #endif

 #endif /* PNG_INTERNAL */

 /* The following uses const char * instead of char * for error
  * and warning message functions, so some compilers won't complain.
  * If you do not want to use const, define PNG_NO_CONST here.
  */

 #ifndef PNG_NO_CONST
 #  define PNG_CONST const
 #else
 #  define PNG_CONST
 #endif

 /* The following defines give you the ability to remove code from the
  * library that you will not be using.  I wish I could figure out how to
  * automate this, but I can't do that without making it seriously hard
  * on the users.  So if you are not using an ability, change the #define
  * to and #undef, and that part of the library will not be compiled.  If
  * your linker can't find a function, you may want to make sure the
  * ability is defined here.  Some of these depend upon some others being
  * defined.  I haven't figured out all the interactions here, so you may
  * have to experiment awhile to get everything to compile.  If you are
  * creating or using a shared library, you probably shouldn't touch this,
  * as it will affect the size of the structures, and this will cause bad
  * things to happen if the library and/or application ever change.
  */

 /* Any transformations you will not be using can be undef'ed here */

 /* GR-P, 0.96a: Set "*TRANSFORMS_SUPPORTED as default but allow user
    to turn it off with "*TRANSFORMS_NOT_SUPPORTED" on the compile line,
    then pick and choose which ones to define without having to edit
    this file. It is safe to use the *TRANSFORMS_NOT_SUPPORTED if you
    only want to have a png-compliant reader/writer but don't need
    any of the extra transformations.  This saves about 80 kbytes in a
    typical installation of the library.
  */


 #ifndef PNG_READ_TRANSFORMS_NOT_SUPPORTED
 #define PNG_READ_TRANSFORMS_SUPPORTED
 #endif
 #ifndef PNG_WRITE_TRANSFORMS_NOT_SUPPORTED
 #define PNG_WRITE_TRANSFORMS_SUPPORTED
 #endif

 #ifdef PNG_READ_TRANSFORMS_SUPPORTED
 #define PNG_READ_EXPAND_SUPPORTED
 #define PNG_READ_SHIFT_SUPPORTED
 #define PNG_READ_PACK_SUPPORTED
 #define PNG_READ_BGR_SUPPORTED
 #define PNG_READ_SWAP_SUPPORTED
 #define PNG_READ_PACKSWAP_SUPPORTED
 #define PNG_READ_INVERT_SUPPORTED
 #define PNG_READ_DITHER_SUPPORTED
 #define PNG_READ_BACKGROUND_SUPPORTED
 #define PNG_READ_16_TO_8_SUPPORTED
 #define PNG_READ_FILLER_SUPPORTED
 #define PNG_READ_GAMMA_SUPPORTED
 #define PNG_READ_GRAY_TO_RGB_SUPPORTED
 #define PNG_READ_SWAP_ALPHA_SUPPORTED
 #define PNG_READ_INVERT_ALPHA_SUPPORTED
 #define PNG_READ_STRIP_ALPHA_SUPPORTED
 #define PNG_READ_USER_TRANSFORM_SUPPORTED
 /* the following aren't implemented yet
 #define PNG_READ_RGB_TO_GRAY_SUPPORTED
  */
 #endif /* PNG_READ_TRANSFORMS_SUPPORTED */

 #ifndef PNG_PROGRESSIVE_READ_NOT_SUPPORTED   /* if you don't do progressive   */
 #define PNG_PROGRESSIVE_READ_SUPPORTED       /* reading.  This is not talking */
 #endif                               /* about interlacing capability!  You'll */
               /* still have interlacing unless you change the following line: */
 #define PNG_READ_INTERLACING_SUPPORTED /* required for PNG-compliant decoders */
 #define PNG_READ_COMPOSITE_NODIV_SUPPORTED    /* well tested on Intel and SGI */

 #ifdef PNG_WRITE_TRANSFORMS_SUPPORTED
 #define PNG_WRITE_SHIFT_SUPPORTED
 #define PNG_WRITE_PACK_SUPPORTED
 #define PNG_WRITE_BGR_SUPPORTED
 #define PNG_WRITE_SWAP_SUPPORTED
 #define PNG_WRITE_PACKSWAP_SUPPORTED
 #define PNG_WRITE_INVERT_SUPPORTED
 #define PNG_WRITE_FILLER_SUPPORTED  /* This is the same as WRITE_STRIP_ALPHA */
 #define PNG_WRITE_FLUSH_SUPPORTED
 #define PNG_WRITE_SWAP_ALPHA_SUPPORTED
 #define PNG_WRITE_INVERT_ALPHA_SUPPORTED
 #define PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
 #define PNG_WRITE_USER_TRANSFORM_SUPPORTED
 #endif /* PNG_WRITE_TRANSFORMS_SUPPORTED */

 #define PNG_WRITE_INTERLACING_SUPPORTED  /* not required for PNG-compliant
                                             encoders, but can cause trouble
                                             if left undefined */

 #if !defined(PNG_NO_STDIO)
 #define PNG_TIME_RFC1123_SUPPORTED
 #endif

 /* This adds extra functions in pngget.c for accessing data from the
  * info pointer (added in version 0.99)
  * png_get_image_width()
  * png_get_image_height()
  * png_get_bit_depth()
  * png_get_color_type()
  * png_get_compression_type()
  * png_get_filter_type()
  * png_get_interlace_type()
  * png_get_pixel_aspect_ratio()
  * png_get_pixels_per_meter()
  * png_get_x_offset_pixels()
  * png_get_y_offset_pixels()
  * png_get_x_offset_microns()
  * png_get_y_offset_microns()
  */
 #if !defined(PNG_NO_EASY_ACCESS)
 #define PNG_EASY_ACCESS_SUPPORTED
 #endif

 /* These are currently experimental features, define them if you want */

 /* very little testing */
 /*
 #define PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED
 */

 /* This is only for PowerPC big-endian and 680x0 systems */
 /* some testing */
 /*
 #define PNG_READ_BIG_ENDIAN_SUPPORTED
 */

 /* These functions are turned off by default, as they will be phased out. */
 /*
 #define  PNG_USELESS_TESTS_SUPPORTED
 #define  PNG_CORRECT_PALETTE_SUPPORTED
 */

 /* Any chunks you are not interested in, you can undef here.  The
  * ones that allocate memory may be expecially important (hIST,
  * tEXt, zTXt, tRNS, pCAL).  Others will just save time and make png_info
  * a bit smaller.
  */

 #ifndef PNG_READ_ANCILLARY_CHUNKS_NOT_SUPPORTED
 #define PNG_READ_ANCILLARY_CHUNKS_SUPPORTED
 #endif
 #ifndef PNG_WRITE_ANCILLARY_CHUNKS_NOT_SUPPORTED
 #define PNG_WRITE_ANCILLARY_CHUNKS_SUPPORTED
 #endif

 #ifdef PNG_READ_ANCILLARY_CHUNKS_SUPPORTED
 #define PNG_READ_bKGD_SUPPORTED
 #define PNG_READ_cHRM_SUPPORTED
 #define PNG_READ_gAMA_SUPPORTED
 #define PNG_READ_hIST_SUPPORTED
 #define PNG_READ_oFFs_SUPPORTED
 #define PNG_READ_pCAL_SUPPORTED
 #define PNG_READ_pHYs_SUPPORTED
 #define PNG_READ_sBIT_SUPPORTED
 #define PNG_READ_sRGB_SUPPORTED
 #define PNG_READ_tEXt_SUPPORTED
 #define PNG_READ_tIME_SUPPORTED
 #define PNG_READ_tRNS_SUPPORTED
 #define PNG_READ_zTXt_SUPPORTED
 #define PNG_READ_OPT_PLTE_SUPPORTED /* only affects support of the optional */
                                     /* PLTE chunk in RGB and RGBA images */
 #endif /* PNG_READ_ANCILLARY_CHUNKS_SUPPORTED */

 #ifdef PNG_WRITE_ANCILLARY_CHUNKS_SUPPORTED
 #define PNG_WRITE_bKGD_SUPPORTED
 #define PNG_WRITE_cHRM_SUPPORTED
 #define PNG_WRITE_gAMA_SUPPORTED
 #define PNG_WRITE_hIST_SUPPORTED
 #define PNG_WRITE_oFFs_SUPPORTED
 #define PNG_WRITE_pCAL_SUPPORTED
 #define PNG_WRITE_pHYs_SUPPORTED
 #define PNG_WRITE_sBIT_SUPPORTED
 #define PNG_WRITE_sRGB_SUPPORTED
 #define PNG_WRITE_tEXt_SUPPORTED
 #define PNG_WRITE_tIME_SUPPORTED
 #define PNG_WRITE_tRNS_SUPPORTED
 #define PNG_WRITE_zTXt_SUPPORTED
 #endif /* PNG_WRITE_ANCILLARY_CHUNKS_SUPPORTED */

 /* need the time information for reading tIME chunks */
 #if defined(PNG_READ_tIME_SUPPORTED) || defined(PNG_WRITE_tIME_SUPPORTED)
 #include <time.h>
 #endif

 /* Some typedefs to get us started.  These should be safe on most of the
  * common platforms.  The typedefs should be at least as large as the
  * numbers suggest (a png_uint_32 must be at least 32 bits long), but they
  * don't have to be exactly that size.  Some compilers dislike passing
  * unsigned shorts as function parameters, so you may be better off using
  * unsigned int for png_uint_16.  Likewise, for 64-bit systems, you may
  * want to have unsigned int for png_uint_32 instead of unsigned long.
  */

 typedef unsigned long png_uint_32;
 typedef long png_int_32;
 typedef unsigned short png_uint_16;
 typedef short png_int_16;
 typedef unsigned char png_byte;

 /* This is usually size_t.  It is typedef'ed just in case you need it to
    change (I'm not sure if you will or not, so I thought I'd be safe) */
 typedef size_t png_size_t;

 /* The following is needed for medium model support.  It cannot be in the
  * PNG_INTERNAL section.  Needs modification for other compilers besides
  * MSC.  Model independent support declares all arrays and pointers to be
  * large using the far keyword.  The zlib version used must also support
  * model independent data.  As of version zlib 1.0.4, the necessary changes
  * have been made in zlib.  The USE_FAR_KEYWORD define triggers other
  * changes that are needed. (Tim Wegner)
  */

 /* Separate compiler dependencies (problem here is that zlib.h always
    defines FAR. (SJT) */
 #ifdef __BORLANDC__
 #if defined(__LARGE__) || defined(__HUGE__) || defined(__COMPACT__)
 #define LDATA 1
 #else
 #define LDATA 0
 #endif

 #if !defined(__WIN32__) && !defined(__FLAT__)
 #define PNG_MAX_MALLOC_64K
 #if (LDATA != 1)
 #ifndef FAR
 #define FAR __far
 #endif
 #define USE_FAR_KEYWORD
 #endif   /* LDATA != 1 */

 /* Possibly useful for moving data out of default segment.
  * Uncomment it if you want. Could also define FARDATA as
  * const if your compiler supports it. (SJT)
 #  define FARDATA FAR
  */
 #endif  /* __WIN32__, __FLAT__ */

 #endif   /* __BORLANDC__ */


 /* Suggest testing for specific compiler first before testing for
  * FAR.  The Watcom compiler defines both __MEDIUM__ and M_I86MM,
  * making reliance oncertain keywords suspect. (SJT)
  */

 /* MSC Medium model */
 #if defined(FAR)
 #  if defined(M_I86MM)
 #     define USE_FAR_KEYWORD
 #     define FARDATA FAR
 #     include <dos.h>
 #  endif
 #endif

 /* SJT: default case */
 #ifndef FAR
 #   define FAR
 #endif

 /* At this point FAR is always defined */
 #ifndef FARDATA
 #define FARDATA
 #endif

 /* Add typedefs for pointers */
 typedef void            FAR * png_voidp;
 typedef png_byte        FAR * png_bytep;
 typedef png_uint_32     FAR * png_uint_32p;
 typedef png_int_32      FAR * png_int_32p;
 typedef png_uint_16     FAR * png_uint_16p;
 typedef png_int_16      FAR * png_int_16p;
 typedef PNG_CONST char  FAR * png_const_charp;
 typedef char            FAR * png_charp;
 typedef double          FAR * png_doublep;

 /* Pointers to pointers; i.e. arrays */
 typedef png_byte        FAR * FAR * png_bytepp;
 typedef png_uint_32     FAR * FAR * png_uint_32pp;
 typedef png_int_32      FAR * FAR * png_int_32pp;
 typedef png_uint_16     FAR * FAR * png_uint_16pp;
 typedef png_int_16      FAR * FAR * png_int_16pp;
 typedef PNG_CONST char  FAR * FAR * png_const_charpp;
 typedef char            FAR * FAR * png_charpp;
 typedef double          FAR * FAR * png_doublepp;

 /* Pointers to pointers to pointers; i.e. pointer to array */
 typedef char            FAR * FAR * FAR * png_charppp;

 /* libpng typedefs for types in zlib. If zlib changes
  * or another compression library is used, then change these.
  * Eliminates need to change all the source files.
  */
 typedef charf *         png_zcharp;
 typedef charf * FAR *   png_zcharpp;
 typedef z_stream FAR *  png_zstreamp;

 /* allow for compilation as dll under MS Windows */
 #ifdef __WIN32DLL__
 #define PNG_EXPORT(type,symbol) __declspec(dllexport) type symbol
 #endif

 /* allow for compilation as dll with BORLAND C++ 5.0 */
 #if defined(__BORLANDC__) && defined(_Windows) && defined(__DLL__)
 #   define PNG_EXPORT(type,symbol) type _export symbol
 #endif

 /* allow for compilation as shared lib under BeOS */
 #ifdef __BEOSDLL__
 #define PNG_EXPORT(type,symbol) __declspec(export) type symbol
 #endif

 #ifndef PNG_EXPORT
 #define PNG_EXPORT(type,symbol) type symbol
 #endif


 /* User may want to use these so not in PNG_INTERNAL. Any library functions
  * that are passed far data must be model independent.
  */

 #if defined(USE_FAR_KEYWORD)  /* memory model independent fns */
 /* use this to make far-to-near assignments */
 #   define CHECK   1
 #   define NOCHECK 0
 #   define CVT_PTR(ptr) (png_far_to_near(png_ptr,ptr,CHECK))
 #   define CVT_PTR_NOCHECK(ptr) (png_far_to_near(png_ptr,ptr,NOCHECK))
 #   define png_strlen _fstrlen
 #   define png_memcmp _fmemcmp      /* SJT: added */
 #   define png_memcpy _fmemcpy
 #   define png_memset _fmemset
 #else /* use the usual functions */
 #   define CVT_PTR(ptr)         (ptr)
 #   define CVT_PTR_NOCHECK(ptr) (ptr)
 #   define png_strlen strlen
 #   define png_memcmp memcmp     /* SJT: added */
 #   define png_memcpy memcpy
 #   define png_memset memset
 #endif
 /* End of memory model independent support */

 /* Just a double check that someone hasn't tried to define something
  * contradictory.
  */
 #if (PNG_ZBUF_SIZE > 65536) && defined(PNG_MAX_MALLOC_64K)
 #undef PNG_ZBUF_SIZE
 #define PNG_ZBUF_SIZE 65536
 #endif

 #endif /* PNGCONF_H */

	/* pngconf.h - machine configurable file for libpng
	*
	* libpng 1.00
	* For conditions of distribution and use, see copyright notice in png.h
	* Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
	* Copyright (c) 1996, 1997 Andreas Dilger
	* Copyright (c) 1998, Glenn Randers-Pehrson
	* March 7, 1998
	*/

	/* Any machine specific code is near the front of this file, so if you
	* are configuring libpng for a machine, you may want to read the section
	* starting here down to where it starts to typedef png_color, png_text,
	* and png_info.
	*/

	#ifndef PNGCONF_H
	#define PNGCONF_H

	/* This is the size of the compression buffer, and thus the size of
	* an IDAT chunk. Make this whatever size you feel is best for your
	* machine. One of these will be allocated per png_struct. When this
	* is full, it writes the data to the disk, and does some other
	* calculations. Making this an extremely small size will slow
	* the library down, but you may want to experiment to determine
	* where it becomes significant, if you are concerned with memory
	* usage. Note that zlib allocates at least 32Kb also. For readers,
	* this describes the size of the buffer available to read the data in.
	* Unless this gets smaller than the size of a row (compressed),
	* it should not make much difference how big this is.
	*/

	#ifndef PNG_ZBUF_SIZE
	#define PNG_ZBUF_SIZE 8192
	#endif

	/* If you are running on a machine where you cannot allocate more
	* than 64K of memory at once, uncomment this. While libpng will not
	* normally need that much memory in a chunk (unless you load up a very
	* large file), zlib needs to know how big of a chunk it can use, and
	* libpng thus makes sure to check any memory allocation to verify it
	* will fit into memory.
	#define PNG_MAX_MALLOC_64K
	*/
	#if defined(MAXSEG_64K) && !defined(PNG_MAX_MALLOC_64K)
	#define PNG_MAX_MALLOC_64K
	#endif

	/* This protects us against compilers which run on a windowing system
	* and thus don't have or would rather us not use the stdio types:
	* stdin, stdout, and stderr. The only one currently used is stderr
	* in png_error() and png_warning(). #defining PNG_NO_STDIO will
	* prevent these from being compiled and used.
	* #define PNG_NO_STDIO
	*/

	#ifndef PNG_NO_STDIO
	#include <stdio.h>
	#endif

	/* This macro protects us against machines that don't have function
	* prototypes (ie K&R style headers). If your compiler does not handle
	* function prototypes, define this macro and use the included ansi2knr.
	* I've always been able to use _NO_PROTO as the indicator, but you may
	* need to drag the empty declaration out in front of here, or change the
	* ifdef to suit your own needs.
	*/
	#ifndef PNGARG

	#ifdef OF /* zlib prototype munger */
	#define PNGARG(arglist) OF(arglist)
	#else

	#ifdef _NO_PROTO
	#define PNGARG(arglist) ()
	#else
	#define PNGARG(arglist) arglist
	#endif /* _NO_PROTO */

	#endif /* OF */

	#endif /* PNGARG */

	/* Try to determine if we are compiling on a Mac. Note that testing for
	* just __MWERKS__ is not good enough, because the Codewarrior is now used
	* on non-Mac platforms.
	*/
	#ifndef MACOS
	#if (defined(__MWERKS__) && defined(macintosh)) \|\| defined(applec) \|\| \
	defined(THINK_C) \|\| defined(__SC__) \|\| defined(TARGET_OS_MAC)
	#define MACOS
	#endif
	#endif

	/* enough people need this for various reasons to include it here */
	#if !defined(MACOS) && !defined(RISCOS)
	#include <sys/types.h>
	#endif

	/* This is an attempt to force a single setjmp behaviour on Linux. If
	* the X config stuff didn't define _BSD_SOURCE we wouldn't need this.
	*/
	#ifdef __linux__
	#ifdef _BSD_SOURCE
	#define _PNG_SAVE_BSD_SOURCE
	#undef _BSD_SOURCE
	#endif
	#ifdef _SETJMP_H
	__png.h__ already includes setjmp.h
	__dont__ include it again
	#endif
	#endif /* __linux__ */

	/* include setjmp.h for error handling */
	#include <setjmp.h>

	#ifdef __linux__
	#ifdef _PNG_SAVE_BSD_SOURCE
	#define _BSD_SOURCE
	#undef _PNG_SAVE_BSD_SOURCE
	#endif
	#endif /* __linux__ */

	#ifdef BSD
	#include <strings.h>
	#else
	#include <string.h>
	#endif

	/* Other defines for things like memory and the like can go here. */
	#ifdef PNG_INTERNAL
	#include <stdlib.h>

	/* The functions exported by PNG_EXTERN are PNG_INTERNAL functions, which
	* aren't usually used outside the library (as far as I know), so it is
	* debatable if they should be exported at all. In the future, when it is
	* possible to have run-time registry of chunk-handling functions, some of
	* these will be made available again.
	#define PNG_EXTERN extern
	*/
	#define PNG_EXTERN

	/* Other defines specific to compilers can go here. Try to keep
	* them inside an appropriate ifdef/endif pair for portability.
	*/

	#if defined(MACOS)
	/* We need to check that <math.h> hasn't already been included earlier
	* as it seems it doesn't agree with <fp.h>, yet we should really use
	* <fp.h> if possible.
	*/
	#if !defined(__MATH_H__) && !defined(__MATH_H) && !defined(__cmath__)
	#include <fp.h>
	#endif
	#else
	#include <math.h>
	#endif

	/* Codewarrior on NT has linking problems without this. */
	#if defined(__MWERKS__) && defined(WIN32)
	#define PNG_ALWAYS_EXTERN
	#endif

	/* For some reason, Borland C++ defines memcmp, etc. in mem.h, not
	* stdlib.h like it should (I think). Or perhaps this is a C++
	* "feature"?
	*/
	#ifdef __TURBOC__
	#include <mem.h>
	#include "alloc.h"
	#endif

	#ifdef _MSC_VER
	#include <malloc.h>
	#endif

	/* This controls how fine the dithering gets. As this allocates
	* a largish chunk of memory (32K), those who are not as concerned
	* with dithering quality can decrease some or all of these.
	*/
	#ifndef PNG_DITHER_RED_BITS
	#define PNG_DITHER_RED_BITS 5
	#endif
	#ifndef PNG_DITHER_GREEN_BITS
	#define PNG_DITHER_GREEN_BITS 5
	#endif
	#ifndef PNG_DITHER_BLUE_BITS
	#define PNG_DITHER_BLUE_BITS 5
	#endif

	/* This controls how fine the gamma correction becomes when you
	* are only interested in 8 bits anyway. Increasing this value
	* results in more memory being used, and more pow() functions
	* being called to fill in the gamma tables. Don't set this value
	* less then 8, and even that may not work (I haven't tested it).
	*/

	#ifndef PNG_MAX_GAMMA_8
	#define PNG_MAX_GAMMA_8 11
	#endif

	/* This controls how much a difference in gamma we can tolerate before
	* we actually start doing gamma conversion.
	*/
	#ifndef PNG_GAMMA_THRESHOLD
	#define PNG_GAMMA_THRESHOLD 0.05
	#endif

	#endif /* PNG_INTERNAL */

	/* The following uses const char * instead of char * for error
	* and warning message functions, so some compilers won't complain.
	* If you do not want to use const, define PNG_NO_CONST here.
	*/

	#ifndef PNG_NO_CONST
	# define PNG_CONST const
	#else
	# define PNG_CONST
	#endif

	/* The following defines give you the ability to remove code from the
	* library that you will not be using. I wish I could figure out how to
	* automate this, but I can't do that without making it seriously hard
	* on the users. So if you are not using an ability, change the #define
	* to and #undef, and that part of the library will not be compiled. If
	* your linker can't find a function, you may want to make sure the
	* ability is defined here. Some of these depend upon some others being
	* defined. I haven't figured out all the interactions here, so you may
	* have to experiment awhile to get everything to compile. If you are
	* creating or using a shared library, you probably shouldn't touch this,
	* as it will affect the size of the structures, and this will cause bad
	* things to happen if the library and/or application ever change.
	*/

	/* Any transformations you will not be using can be undef'ed here */

	/* GR-P, 0.96a: Set "*TRANSFORMS_SUPPORTED as default but allow user
	to turn it off with "*TRANSFORMS_NOT_SUPPORTED" on the compile line,
	then pick and choose which ones to define without having to edit
	this file. It is safe to use the *TRANSFORMS_NOT_SUPPORTED if you
	only want to have a png-compliant reader/writer but don't need
	any of the extra transformations. This saves about 80 kbytes in a
	typical installation of the library.
	*/


	#ifndef PNG_READ_TRANSFORMS_NOT_SUPPORTED
	#define PNG_READ_TRANSFORMS_SUPPORTED
	#endif
	#ifndef PNG_WRITE_TRANSFORMS_NOT_SUPPORTED
	#define PNG_WRITE_TRANSFORMS_SUPPORTED
	#endif

	#ifdef PNG_READ_TRANSFORMS_SUPPORTED
	#define PNG_READ_EXPAND_SUPPORTED
	#define PNG_READ_SHIFT_SUPPORTED
	#define PNG_READ_PACK_SUPPORTED
	#define PNG_READ_BGR_SUPPORTED
	#define PNG_READ_SWAP_SUPPORTED
	#define PNG_READ_PACKSWAP_SUPPORTED
	#define PNG_READ_INVERT_SUPPORTED
	#define PNG_READ_DITHER_SUPPORTED
	#define PNG_READ_BACKGROUND_SUPPORTED
	#define PNG_READ_16_TO_8_SUPPORTED
	#define PNG_READ_FILLER_SUPPORTED
	#define PNG_READ_GAMMA_SUPPORTED
	#define PNG_READ_GRAY_TO_RGB_SUPPORTED
	#define PNG_READ_SWAP_ALPHA_SUPPORTED
	#define PNG_READ_INVERT_ALPHA_SUPPORTED
	#define PNG_READ_STRIP_ALPHA_SUPPORTED
	#define PNG_READ_USER_TRANSFORM_SUPPORTED
	/* the following aren't implemented yet
	#define PNG_READ_RGB_TO_GRAY_SUPPORTED
	*/
	#endif /* PNG_READ_TRANSFORMS_SUPPORTED */

	#ifndef PNG_PROGRESSIVE_READ_NOT_SUPPORTED /* if you don't do progressive */
	#define PNG_PROGRESSIVE_READ_SUPPORTED /* reading. This is not talking */
	#endif /* about interlacing capability! You'll */
	/* still have interlacing unless you change the following line: */
	#define PNG_READ_INTERLACING_SUPPORTED /* required for PNG-compliant decoders */
	#define PNG_READ_COMPOSITE_NODIV_SUPPORTED /* well tested on Intel and SGI */

	#ifdef PNG_WRITE_TRANSFORMS_SUPPORTED
	#define PNG_WRITE_SHIFT_SUPPORTED
	#define PNG_WRITE_PACK_SUPPORTED
	#define PNG_WRITE_BGR_SUPPORTED
	#define PNG_WRITE_SWAP_SUPPORTED
	#define PNG_WRITE_PACKSWAP_SUPPORTED
	#define PNG_WRITE_INVERT_SUPPORTED
	#define PNG_WRITE_FILLER_SUPPORTED /* This is the same as WRITE_STRIP_ALPHA */
	#define PNG_WRITE_FLUSH_SUPPORTED
	#define PNG_WRITE_SWAP_ALPHA_SUPPORTED
	#define PNG_WRITE_INVERT_ALPHA_SUPPORTED
	#define PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
	#define PNG_WRITE_USER_TRANSFORM_SUPPORTED
	#endif /* PNG_WRITE_TRANSFORMS_SUPPORTED */

	#define PNG_WRITE_INTERLACING_SUPPORTED /* not required for PNG-compliant
	encoders, but can cause trouble
	if left undefined */

	#if !defined(PNG_NO_STDIO)
	#define PNG_TIME_RFC1123_SUPPORTED
	#endif

	/* This adds extra functions in pngget.c for accessing data from the
	* info pointer (added in version 0.99)
	* png_get_image_width()
	* png_get_image_height()
	* png_get_bit_depth()
	* png_get_color_type()
	* png_get_compression_type()
	* png_get_filter_type()
	* png_get_interlace_type()
	* png_get_pixel_aspect_ratio()
	* png_get_pixels_per_meter()
	* png_get_x_offset_pixels()
	* png_get_y_offset_pixels()
	* png_get_x_offset_microns()
	* png_get_y_offset_microns()
	*/
	#if !defined(PNG_NO_EASY_ACCESS)
	#define PNG_EASY_ACCESS_SUPPORTED
	#endif

	/* These are currently experimental features, define them if you want */

	/* very little testing */
	/*
	#define PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED
	*/

	/* This is only for PowerPC big-endian and 680x0 systems */
	/* some testing */
	/*
	#define PNG_READ_BIG_ENDIAN_SUPPORTED
	*/

	/* These functions are turned off by default, as they will be phased out. */
	/*
	#define PNG_USELESS_TESTS_SUPPORTED
	#define PNG_CORRECT_PALETTE_SUPPORTED
	*/

	/* Any chunks you are not interested in, you can undef here. The
	* ones that allocate memory may be expecially important (hIST,
	* tEXt, zTXt, tRNS, pCAL). Others will just save time and make png_info
	* a bit smaller.
	*/

	#ifndef PNG_READ_ANCILLARY_CHUNKS_NOT_SUPPORTED
	#define PNG_READ_ANCILLARY_CHUNKS_SUPPORTED
	#endif
	#ifndef PNG_WRITE_ANCILLARY_CHUNKS_NOT_SUPPORTED
	#define PNG_WRITE_ANCILLARY_CHUNKS_SUPPORTED
	#endif

	#ifdef PNG_READ_ANCILLARY_CHUNKS_SUPPORTED
	#define PNG_READ_bKGD_SUPPORTED
	#define PNG_READ_cHRM_SUPPORTED
	#define PNG_READ_gAMA_SUPPORTED
	#define PNG_READ_hIST_SUPPORTED
	#define PNG_READ_oFFs_SUPPORTED
	#define PNG_READ_pCAL_SUPPORTED
	#define PNG_READ_pHYs_SUPPORTED
	#define PNG_READ_sBIT_SUPPORTED
	#define PNG_READ_sRGB_SUPPORTED
	#define PNG_READ_tEXt_SUPPORTED
	#define PNG_READ_tIME_SUPPORTED
	#define PNG_READ_tRNS_SUPPORTED
	#define PNG_READ_zTXt_SUPPORTED
	#define PNG_READ_OPT_PLTE_SUPPORTED /* only affects support of the optional */
	/* PLTE chunk in RGB and RGBA images */
	#endif /* PNG_READ_ANCILLARY_CHUNKS_SUPPORTED */

	#ifdef PNG_WRITE_ANCILLARY_CHUNKS_SUPPORTED
	#define PNG_WRITE_bKGD_SUPPORTED
	#define PNG_WRITE_cHRM_SUPPORTED
	#define PNG_WRITE_gAMA_SUPPORTED
	#define PNG_WRITE_hIST_SUPPORTED
	#define PNG_WRITE_oFFs_SUPPORTED
	#define PNG_WRITE_pCAL_SUPPORTED
	#define PNG_WRITE_pHYs_SUPPORTED
	#define PNG_WRITE_sBIT_SUPPORTED
	#define PNG_WRITE_sRGB_SUPPORTED
	#define PNG_WRITE_tEXt_SUPPORTED
	#define PNG_WRITE_tIME_SUPPORTED
	#define PNG_WRITE_tRNS_SUPPORTED
	#define PNG_WRITE_zTXt_SUPPORTED
	#endif /* PNG_WRITE_ANCILLARY_CHUNKS_SUPPORTED */

	/* need the time information for reading tIME chunks */
	#if defined(PNG_READ_tIME_SUPPORTED) \|\| defined(PNG_WRITE_tIME_SUPPORTED)
	#include <time.h>
	#endif

	/* Some typedefs to get us started. These should be safe on most of the
	* common platforms. The typedefs should be at least as large as the
	* numbers suggest (a png_uint_32 must be at least 32 bits long), but they
	* don't have to be exactly that size. Some compilers dislike passing
	* unsigned shorts as function parameters, so you may be better off using
	* unsigned int for png_uint_16. Likewise, for 64-bit systems, you may
	* want to have unsigned int for png_uint_32 instead of unsigned long.
	*/

	typedef unsigned long png_uint_32;
	typedef long png_int_32;
	typedef unsigned short png_uint_16;
	typedef short png_int_16;
	typedef unsigned char png_byte;

	/* This is usually size_t. It is typedef'ed just in case you need it to
	change (I'm not sure if you will or not, so I thought I'd be safe) */
	typedef size_t png_size_t;

	/* The following is needed for medium model support. It cannot be in the
	* PNG_INTERNAL section. Needs modification for other compilers besides
	* MSC. Model independent support declares all arrays and pointers to be
	* large using the far keyword. The zlib version used must also support
	* model independent data. As of version zlib 1.0.4, the necessary changes
	* have been made in zlib. The USE_FAR_KEYWORD define triggers other
	* changes that are needed. (Tim Wegner)
	*/

	/* Separate compiler dependencies (problem here is that zlib.h always
	defines FAR. (SJT) */
	#ifdef __BORLANDC__
	#if defined(__LARGE__) \|\| defined(__HUGE__) \|\| defined(__COMPACT__)
	#define LDATA 1
	#else
	#define LDATA 0
	#endif

	#if !defined(__WIN32__) && !defined(__FLAT__)
	#define PNG_MAX_MALLOC_64K
	#if (LDATA != 1)
	#ifndef FAR
	#define FAR __far
	#endif
	#define USE_FAR_KEYWORD
	#endif /* LDATA != 1 */

	/* Possibly useful for moving data out of default segment.
	* Uncomment it if you want. Could also define FARDATA as
	* const if your compiler supports it. (SJT)
	# define FARDATA FAR
	*/
	#endif /* __WIN32__, __FLAT__ */

	#endif /* __BORLANDC__ */


	/* Suggest testing for specific compiler first before testing for
	* FAR. The Watcom compiler defines both __MEDIUM__ and M_I86MM,
	* making reliance oncertain keywords suspect. (SJT)
	*/

	/* MSC Medium model */
	#if defined(FAR)
	# if defined(M_I86MM)
	# define USE_FAR_KEYWORD
	# define FARDATA FAR
	# include <dos.h>
	# endif
	#endif

	/* SJT: default case */
	#ifndef FAR
	# define FAR
	#endif

	/* At this point FAR is always defined */
	#ifndef FARDATA
	#define FARDATA
	#endif

	/* Add typedefs for pointers */
	typedef void FAR * png_voidp;
	typedef png_byte FAR * png_bytep;
	typedef png_uint_32 FAR * png_uint_32p;
	typedef png_int_32 FAR * png_int_32p;
	typedef png_uint_16 FAR * png_uint_16p;
	typedef png_int_16 FAR * png_int_16p;
	typedef PNG_CONST char FAR * png_const_charp;
	typedef char FAR * png_charp;
	typedef double FAR * png_doublep;

	/* Pointers to pointers; i.e. arrays */
	typedef png_byte FAR * FAR * png_bytepp;
	typedef png_uint_32 FAR * FAR * png_uint_32pp;
	typedef png_int_32 FAR * FAR * png_int_32pp;
	typedef png_uint_16 FAR * FAR * png_uint_16pp;
	typedef png_int_16 FAR * FAR * png_int_16pp;
	typedef PNG_CONST char FAR * FAR * png_const_charpp;
	typedef char FAR * FAR * png_charpp;
	typedef double FAR * FAR * png_doublepp;

	/* Pointers to pointers to pointers; i.e. pointer to array */
	typedef char FAR * FAR * FAR * png_charppp;

	/* libpng typedefs for types in zlib. If zlib changes
	* or another compression library is used, then change these.
	* Eliminates need to change all the source files.
	*/
	typedef charf * png_zcharp;
	typedef charf * FAR * png_zcharpp;
	typedef z_stream FAR * png_zstreamp;

	/* allow for compilation as dll under MS Windows */
	#ifdef __WIN32DLL__
	#define PNG_EXPORT(type,symbol) __declspec(dllexport) type symbol
	#endif

	/* allow for compilation as dll with BORLAND C++ 5.0 */
	#if defined(__BORLANDC__) && defined(_Windows) && defined(__DLL__)
	# define PNG_EXPORT(type,symbol) type _export symbol
	#endif

	/* allow for compilation as shared lib under BeOS */
	#ifdef __BEOSDLL__
	#define PNG_EXPORT(type,symbol) __declspec(export) type symbol
	#endif

	#ifndef PNG_EXPORT
	#define PNG_EXPORT(type,symbol) type symbol
	#endif


	/* User may want to use these so not in PNG_INTERNAL. Any library functions
	* that are passed far data must be model independent.
	*/

	#if defined(USE_FAR_KEYWORD) /* memory model independent fns */
	/* use this to make far-to-near assignments */
	# define CHECK 1
	# define NOCHECK 0
	# define CVT_PTR(ptr) (png_far_to_near(png_ptr,ptr,CHECK))
	# define CVT_PTR_NOCHECK(ptr) (png_far_to_near(png_ptr,ptr,NOCHECK))
	# define png_strlen _fstrlen
	# define png_memcmp _fmemcmp /* SJT: added */
	# define png_memcpy _fmemcpy
	# define png_memset _fmemset
	#else /* use the usual functions */
	# define CVT_PTR(ptr) (ptr)
	# define CVT_PTR_NOCHECK(ptr) (ptr)
	# define png_strlen strlen
	# define png_memcmp memcmp /* SJT: added */
	# define png_memcpy memcpy
	# define png_memset memset
	#endif
	/* End of memory model independent support */

	/* Just a double check that someone hasn't tried to define something
	* contradictory.
	*/
	#if (PNG_ZBUF_SIZE > 65536) && defined(PNG_MAX_MALLOC_64K)
	#undef PNG_ZBUF_SIZE
	#define PNG_ZBUF_SIZE 65536
	#endif

	#endif /* PNGCONF_H */