Visualization Library 2.0.0-b5

A lightweight C++ OpenGL middleware for 2D/3D graphics

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compress.c
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1 /* compress.c -- compress a memory buffer
2  * Copyright (C) 1995-2005 Jean-loup Gailly.
3  * For conditions of distribution and use, see copyright notice in zlib.h
4  */
5 
6 /* @(#) $Id$ */
7 
8 #define ZLIB_INTERNAL
9 #include "zlib.h"
10 
11 /* ===========================================================================
12  Compresses the source buffer into the destination buffer. The level
13  parameter has the same meaning as in deflateInit. sourceLen is the byte
14  length of the source buffer. Upon entry, destLen is the total size of the
15  destination buffer, which must be at least 0.1% larger than sourceLen plus
16  12 bytes. Upon exit, destLen is the actual size of the compressed buffer.
17 
18  compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
19  memory, Z_BUF_ERROR if there was not enough room in the output buffer,
20  Z_STREAM_ERROR if the level parameter is invalid.
21 */
22 int ZEXPORT compress2 (dest, destLen, source, sourceLen, level)
23  Bytef *dest;
24  uLongf *destLen;
25  const Bytef *source;
26  uLong sourceLen;
27  int level;
28 {
30  int err;
31 
32  stream.next_in = (z_const Bytef *)source;
33  stream.avail_in = (uInt)sourceLen;
34 #ifdef MAXSEG_64K
35  /* Check for source > 64K on 16-bit machine: */
36  if ((uLong)stream.avail_in != sourceLen) return Z_BUF_ERROR;
37 #endif
38  stream.next_out = dest;
39  stream.avail_out = (uInt)*destLen;
40  if ((uLong)stream.avail_out != *destLen) return Z_BUF_ERROR;
41 
42  stream.zalloc = (alloc_func)0;
43  stream.zfree = (free_func)0;
44  stream.opaque = (voidpf)0;
45 
46  err = deflateInit(&stream, level);
47  if (err != Z_OK) return err;
48 
49  err = deflate(&stream, Z_FINISH);
50  if (err != Z_STREAM_END) {
51  deflateEnd(&stream);
52  return err == Z_OK ? Z_BUF_ERROR : err;
53  }
54  *destLen = stream.total_out;
55 
56  err = deflateEnd(&stream);
57  return err;
58 }
59 
60 /* ===========================================================================
61  */
62 int ZEXPORT compress (dest, destLen, source, sourceLen)
63  Bytef *dest;
64  uLongf *destLen;
65  const Bytef *source;
66  uLong sourceLen;
67 {
68  return compress2(dest, destLen, source, sourceLen, Z_DEFAULT_COMPRESSION);
69 }
70 
71 /* ===========================================================================
72  If the default memLevel or windowBits for deflateInit() is changed, then
73  this function needs to be updated.
74  */
76  uLong sourceLen;
77 {
78  return sourceLen + (sourceLen >> 12) + (sourceLen >> 14) +
79  (sourceLen >> 25) + 13;
80 }
GLuint GLuint stream
unsigned int uInt
Definition: zconf.h:221
uLong ZEXPORT compressBound(uLong sourceLen)
Definition: compress.c:75
Bytef * next_in
Definition: zlib.h:69
uInt avail_in
Definition: zlib.h:70
GLsizei GLsizei GLchar * source
#define Z_DEFAULT_COMPRESSION
Definition: zlib.h:148
int ZEXPORT deflateEnd(z_streamp strm)
Definition: deflate.c:979
#define ZEXPORT(x)
Definition: zconf.h:202
#define Z_BUF_ERROR
Definition: zlib.h:139
voidpf opaque
Definition: zlib.h:82
free_func zfree
Definition: zlib.h:81
#define Z_FINISH
Definition: zlib.h:129
#define Z_OK
Definition: zlib.h:132
#define z_const
Definition: zconf.h:224
unsigned long uLong
Definition: zconf.h:222
GLint level
Byte FAR * voidpf
Definition: zconf.h:239
#define deflateInit(strm, level)
Definition: zlib.h:815
int ZEXPORT compress2(Bytef *dest, uLongf *destLen, const Bytef *source, uLong sourceLen, int level)
Definition: compress.c:22
alloc_func zalloc
Definition: zlib.h:80
int ZEXPORT deflate(z_streamp strm, int flush)
Definition: deflate.c:665
uLong total_out
Definition: zlib.h:75
int ZEXPORT compress(Bytef *dest, uLongf *destLen, const Bytef *source, uLong sourceLen)
Definition: compress.c:62
Byte FAR Bytef
Definition: zconf.h:228
uInt avail_out
Definition: zlib.h:74
uLong FAR uLongf
Definition: zconf.h:233
Bytef * next_out
Definition: zlib.h:73
#define Z_STREAM_END
Definition: zlib.h:133