gif_lib_private.h

/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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/****************************************************************************

gif_lib_private.h - internal giflib routines and structures

SPDX-License-Identifier: MIT

****************************************************************************/

#ifndef _GIF_LIB_PRIVATE_H
#define _GIF_LIB_PRIVATE_H

#include "gif_lib.h"
#include "gif_hash.h"

#ifndef SIZE_MAX
    #define SIZE_MAX     UINTPTR_MAX
#endif

#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;

#ifndef HAVE_REALLOCARRAY
extern void *openbsd_reallocarray(void *optr, size_t nmemb, size_t size);
#define reallocarray openbsd_reallocarray
#endif

#endif /* _GIF_LIB_PRIVATE_H */

/* end */