fltk/jpeg/jinclude.h

158 lines
5.7 KiB
C

/*
* jinclude.h
*
* Copyright (C) 1991-1994, Thomas G. Lane.
* Modified 2017-2022 by Guido Vollbeding.
* This file is part of the Independent JPEG Group's software.
* For conditions of distribution and use, see the accompanying README file.
*
* This file exists to provide a single place to fix any problems with
* including the wrong system include files. (Common problems are taken
* care of by the standard jconfig symbols, but on really weird systems
* you may have to edit this file.)
*
* NOTE: this file is NOT intended to be included by applications using
* the JPEG library. Most applications need only include jpeglib.h.
*/
/* Include auto-config file to find out which system include files we need. */
#include "jconfig.h" /* auto configuration options */
#define JCONFIG_INCLUDED /* so that jpeglib.h doesn't do it again */
/*
* We need the NULL macro and size_t typedef.
* On an ANSI-conforming system it is sufficient to include <stddef.h>.
* Otherwise, we get them from <stdlib.h> or <stdio.h>; we may have to
* pull in <sys/types.h> as well.
* Note that the core JPEG library does not require <stdio.h>;
* only the default error handler and data source/destination modules do.
* But we must pull it in because of the references to FILE in jpeglib.h.
* You can remove those references if you want to compile without <stdio.h>.
*/
#ifdef HAVE_STDDEF_H
#include <stddef.h>
#endif
#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#endif
#ifdef NEED_SYS_TYPES_H
#include <sys/types.h>
#endif
#include <stdio.h>
/*
* We need memory copying and zeroing functions, plus strncpy().
* ANSI and System V implementations declare these in <string.h>.
* BSD doesn't have the mem() functions, but it does have bcopy()/bzero().
* Some systems may declare memset and memcpy in <memory.h>.
*
* NOTE: we assume the size parameters to these functions are of type size_t.
* Change the casts in these macros if not!
*/
#ifdef NEED_BSD_STRINGS
#include <strings.h>
#define MEMZERO(target,size) bzero((void *)(target), (size_t)(size))
#define MEMCOPY(dest,src,size) bcopy((const void *)(src), (void *)(dest), (size_t)(size))
#else /* not BSD, assume ANSI/SysV string lib */
#include <string.h>
#define MEMZERO(target,size) memset((void *)(target), 0, (size_t)(size))
#define MEMCOPY(dest,src,size) memcpy((void *)(dest), (const void *)(src), (size_t)(size))
#endif
/*
* In ANSI C, and indeed any rational implementation, size_t is also the
* type returned by sizeof(). However, it seems there are some irrational
* implementations out there, in which sizeof() returns an int even though
* size_t is defined as long or unsigned long. To ensure consistent results
* we always use this SIZEOF() macro in place of using sizeof() directly.
*/
#define SIZEOF(object) ((size_t) sizeof(object))
/*
* The modules that use fread() and fwrite() always invoke them through
* these macros. On some systems you may need to twiddle the argument casts.
* CAUTION: argument order is different from underlying functions!
*
* Furthermore, macros are provided for fflush() and ferror() in order
* to facilitate adaption by applications using an own FILE class.
*
* You can define your own custom file I/O functions in jconfig.h and
* #define JPEG_HAVE_FILE_IO_CUSTOM there to prevent redefinition here.
*
* You can #define JPEG_USE_FILE_IO_CUSTOM in jconfig.h to use custom file
* I/O functions implemented in Delphi VCL (Visual Component Library)
* in Vcl.Imaging.jpeg.pas for the TJPEGImage component utilizing
* the Delphi RTL (Run-Time Library) TMemoryStream component:
*
* procedure jpeg_stdio_src(var cinfo: jpeg_decompress_struct;
* input_file: TStream); external;
*
* procedure jpeg_stdio_dest(var cinfo: jpeg_compress_struct;
* output_file: TStream); external;
*
* function jfread(var buf; recsize, reccount: Integer; S: TStream): Integer;
* begin
* Result := S.Read(buf, recsize * reccount);
* end;
*
* function jfwrite(const buf; recsize, reccount: Integer; S: TStream): Integer;
* begin
* Result := S.Write(buf, recsize * reccount);
* end;
*
* function jfflush(S: TStream): Integer;
* begin
* Result := 0;
* end;
*
* function jferror(S: TStream): Integer;
* begin
* Result := 0;
* end;
*
* TMemoryStream of Delphi RTL has the distinctive feature to provide dynamic
* memory buffer management with a file/stream-based interface, particularly for
* the write (output) operation, which is easier to apply compared with direct
* implementations as given in jdatadst.c for memory destination. Those direct
* implementations of dynamic memory write tend to be more difficult to use,
* so providing an option like TMemoryStream may be a useful alternative.
*
* The CFile/CMemFile classes of the Microsoft Foundation Class (MFC) Library
* may be used in a similar fashion.
*/
#ifndef JPEG_HAVE_FILE_IO_CUSTOM
#ifdef JPEG_USE_FILE_IO_CUSTOM
extern size_t jfread(void * __ptr, size_t __size, size_t __n, FILE * __stream);
extern size_t jfwrite(const void * __ptr, size_t __size, size_t __n, FILE * __stream);
extern int jfflush(FILE * __stream);
extern int jferror(FILE * __fp);
#define JFREAD(file,buf,sizeofbuf) \
((size_t) jfread((void *) (buf), (size_t) 1, (size_t) (sizeofbuf), (file)))
#define JFWRITE(file,buf,sizeofbuf) \
((size_t) jfwrite((const void *) (buf), (size_t) 1, (size_t) (sizeofbuf), (file)))
#define JFFLUSH(file) jfflush(file)
#define JFERROR(file) jferror(file)
#else
#define JFREAD(file,buf,sizeofbuf) \
((size_t) fread((void *) (buf), (size_t) 1, (size_t) (sizeofbuf), (file)))
#define JFWRITE(file,buf,sizeofbuf) \
((size_t) fwrite((const void *) (buf), (size_t) 1, (size_t) (sizeofbuf), (file)))
#define JFFLUSH(file) fflush(file)
#define JFERROR(file) ferror(file)
#endif
#endif