1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
|
/****************************************************************************
gif_lib_private.h - internal giflib routines and structures
****************************************************************************/
#ifndef _GIF_LIB_PRIVATE_H
#define _GIF_LIB_PRIVATE_H
#include "gif_lib.h"
#include "gif_hash.h"
#define EXTENSION_INTRODUCER 0x21
#define DESCRIPTOR_INTRODUCER 0x2c
#define TERMINATOR_INTRODUCER 0x3b
#define LZ_MAX_CODE 4095 /* Biggest code possible in 12 bits. */
#define LZ_BITS 12
#define FLUSH_OUTPUT 4096 /* Impossible code, to signal flush. */
#define FIRST_CODE 4097 /* Impossible code, to signal first. */
#define NO_SUCH_CODE 4098 /* Impossible code, to signal empty. */
#define FILE_STATE_WRITE 0x01
#define FILE_STATE_SCREEN 0x02
#define FILE_STATE_IMAGE 0x04
#define FILE_STATE_READ 0x08
#define IS_READABLE(Private) (Private->FileState & FILE_STATE_READ)
#define IS_WRITEABLE(Private) (Private->FileState & FILE_STATE_WRITE)
typedef struct GifFilePrivateType {
GifWord FileState, FileHandle, /* Where all this data goes to! */
BitsPerPixel, /* Bits per pixel (Codes uses at least this + 1). */
ClearCode, /* The CLEAR LZ code. */
EOFCode, /* The EOF LZ code. */
RunningCode, /* The next code algorithm can generate. */
RunningBits, /* The number of bits required to represent RunningCode. */
MaxCode1, /* 1 bigger than max. possible code, in RunningBits bits. */
LastCode, /* The code before the current code. */
CrntCode, /* Current algorithm code. */
StackPtr, /* For character stack (see below). */
CrntShiftState; /* Number of bits in CrntShiftDWord. */
unsigned long CrntShiftDWord; /* For bytes decomposition into codes. */
unsigned long PixelCount; /* Number of pixels in image. */
FILE *File; /* File as stream. */
InputFunc Read; /* function to read gif input (TVT) */
OutputFunc Write; /* function to write gif output (MRB) */
GifByteType Buf[256]; /* Compressed input is buffered here. */
GifByteType Stack[LZ_MAX_CODE]; /* Decoded pixels are stacked here. */
GifByteType Suffix[LZ_MAX_CODE + 1]; /* So we can trace the codes. */
GifPrefixType Prefix[LZ_MAX_CODE + 1];
GifHashTableType *HashTable;
bool gif89;
} GifFilePrivateType;
#endif /* _GIF_LIB_PRIVATE_H */
/* end */
|
