1/****************************************************************************
2
3gif_lib_private.h - internal giflib routines and structures
4
5SPDX-License-Identifier: MIT
6
7****************************************************************************/
8
9#ifndef _GIF_LIB_PRIVATE_H
10#define _GIF_LIB_PRIVATE_H
11
12#include "gif_lib.h"
13#include "gif_hash.h"
14
15#ifndef SIZE_MAX
16 #define SIZE_MAX UINTPTR_MAX
17#endif
18
19#define EXTENSION_INTRODUCER 0x21
20#define DESCRIPTOR_INTRODUCER 0x2c
21#define TERMINATOR_INTRODUCER 0x3b
22
23#define LZ_MAX_CODE 4095 /* Biggest code possible in 12 bits. */
24#define LZ_BITS 12
25
26#define FLUSH_OUTPUT 4096 /* Impossible code, to signal flush. */
27#define FIRST_CODE 4097 /* Impossible code, to signal first. */
28#define NO_SUCH_CODE 4098 /* Impossible code, to signal empty. */
29
30#define FILE_STATE_WRITE 0x01
31#define FILE_STATE_SCREEN 0x02
32#define FILE_STATE_IMAGE 0x04
33#define FILE_STATE_READ 0x08
34
35#define IS_READABLE(Private) (Private->FileState & FILE_STATE_READ)
36#define IS_WRITEABLE(Private) (Private->FileState & FILE_STATE_WRITE)
37
38typedef struct GifFilePrivateType {
39 GifWord FileState, FileHandle, /* Where all this data goes to! */
40 BitsPerPixel, /* Bits per pixel (Codes uses at least this + 1). */
41 ClearCode, /* The CLEAR LZ code. */
42 EOFCode, /* The EOF LZ code. */
43 RunningCode, /* The next code algorithm can generate. */
44 RunningBits, /* The number of bits required to represent RunningCode. */
45 MaxCode1, /* 1 bigger than max. possible code, in RunningBits bits. */
46 LastCode, /* The code before the current code. */
47 CrntCode, /* Current algorithm code. */
48 StackPtr, /* For character stack (see below). */
49 CrntShiftState; /* Number of bits in CrntShiftDWord. */
50 unsigned long CrntShiftDWord; /* For bytes decomposition into codes. */
51 unsigned long PixelCount; /* Number of pixels in image. */
52 FILE *File; /* File as stream. */
53 InputFunc Read; /* function to read gif input (TVT) */
54 OutputFunc Write; /* function to write gif output (MRB) */
55 GifByteType Buf[256]; /* Compressed input is buffered here. */
56 GifByteType Stack[LZ_MAX_CODE]; /* Decoded pixels are stacked here. */
57 GifByteType Suffix[LZ_MAX_CODE + 1]; /* So we can trace the codes. */
58 GifPrefixType Prefix[LZ_MAX_CODE + 1];
59 GifHashTableType *HashTable;
60 bool gif89;
61} GifFilePrivateType;
62
63#ifndef HAVE_REALLOCARRAY
64extern void *openbsd_reallocarray(void *optr, size_t nmemb, size_t size);
65#define reallocarray openbsd_reallocarray
66#endif
67
68#endif /* _GIF_LIB_PRIVATE_H */
69
70/* end */
71