1/*
2 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
3 *
4 * This code is free software; you can redistribute it and/or modify it
5 * under the terms of the GNU General Public License version 2 only, as
6 * published by the Free Software Foundation.  Oracle designates this
7 * particular file as subject to the "Classpath" exception as provided
8 * by Oracle in the LICENSE file that accompanied this code.
9 *
10 * This code is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
13 * version 2 for more details (a copy is included in the LICENSE file that
14 * accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License version
17 * 2 along with this work; if not, write to the Free Software Foundation,
18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
19 *
20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
21 * or visit www.oracle.com if you need additional information or have any
22 * questions.
23 */
24
25/****************************************************************************
26
27gif_lib_private.h - internal giflib routines and structures
28
29****************************************************************************/
30
31#ifndef _GIF_LIB_PRIVATE_H
32#define _GIF_LIB_PRIVATE_H
33
34#include "gif_lib.h"
35#include "gif_hash.h"
36
37#define EXTENSION_INTRODUCER      0x21
38#define DESCRIPTOR_INTRODUCER     0x2c
39#define TERMINATOR_INTRODUCER     0x3b
40
41#define LZ_MAX_CODE         4095    /* Biggest code possible in 12 bits. */
42#define LZ_BITS             12
43
44#define FLUSH_OUTPUT        4096    /* Impossible code, to signal flush. */
45#define FIRST_CODE          4097    /* Impossible code, to signal first. */
46#define NO_SUCH_CODE        4098    /* Impossible code, to signal empty. */
47
48#define FILE_STATE_WRITE    0x01
49#define FILE_STATE_SCREEN   0x02
50#define FILE_STATE_IMAGE    0x04
51#define FILE_STATE_READ     0x08
52
53#define IS_READABLE(Private)    (Private->FileState & FILE_STATE_READ)
54#define IS_WRITEABLE(Private)   (Private->FileState & FILE_STATE_WRITE)
55
56typedef struct GifFilePrivateType {
57    GifWord FileState, FileHandle,  /* Where all this data goes to! */
58      BitsPerPixel,     /* Bits per pixel (Codes uses at least this + 1). */
59      ClearCode,   /* The CLEAR LZ code. */
60      EOFCode,     /* The EOF LZ code. */
61      RunningCode, /* The next code algorithm can generate. */
62      RunningBits, /* The number of bits required to represent RunningCode. */
63      MaxCode1,    /* 1 bigger than max. possible code, in RunningBits bits. */
64      LastCode,    /* The code before the current code. */
65      CrntCode,    /* Current algorithm code. */
66      StackPtr,    /* For character stack (see below). */
67      CrntShiftState;    /* Number of bits in CrntShiftDWord. */
68    unsigned long CrntShiftDWord;   /* For bytes decomposition into codes. */
69    unsigned long PixelCount;   /* Number of pixels in image. */
70    FILE *File;    /* File as stream. */
71    InputFunc Read;     /* function to read gif input (TVT) */
72    OutputFunc Write;   /* function to write gif output (MRB) */
73    GifByteType Buf[256];   /* Compressed input is buffered here. */
74    GifByteType Stack[LZ_MAX_CODE]; /* Decoded pixels are stacked here. */
75    GifByteType Suffix[LZ_MAX_CODE + 1];    /* So we can trace the codes. */
76    GifPrefixType Prefix[LZ_MAX_CODE + 1];
77    GifHashTableType *HashTable;
78    bool gif89;
79} GifFilePrivateType;
80
81#endif /* _GIF_LIB_PRIVATE_H */
82
83/* end */
84