dll/win32/windowscodecs/ungif.h

   1 /*
   2  * Gif extracting routines - derived from libungif
   3  *
   4  * Portions Copyright 2006 Mike McCormack
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  19  */
  20
  21 /*
  22  * Original copyright notice:
  23  *
  24  * The GIFLIB distribution is Copyright (c) 1997  Eric S. Raymond
  25  *
  26  * Permission is hereby granted, free of charge, to any person obtaining a copy
  27  * of this software and associated documentation files (the "Software"), to deal
  28  * in the Software without restriction, including without limitation the rights
  29  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  30  * copies of the Software, and to permit persons to whom the Software is
  31  * furnished to do so, subject to the following conditions:
  32  *
  33  * The above copyright notice and this permission notice shall be included in
  34  * all copies or substantial portions of the Software.
  35  */
  36
  37 /******************************************************************************
  38  * In order to make life a little bit easier when using the GIF file format,
  39  * this library was written, and which does all the dirty work...
  40  *
  41  *                                        Written by Gershon Elber,  Jun. 1989
  42  *                                        Hacks by Eric S. Raymond,  Sep. 1992
  43  ******************************************************************************
  44  * History:
  45  * 14 Jun 89 - Version 1.0 by Gershon Elber.
  46  *  3 Sep 90 - Version 1.1 by Gershon Elber (Support for Gif89, Unique names)
  47  * 15 Sep 90 - Version 2.0 by Eric S. Raymond (Changes to support GIF slurp)
  48  * 26 Jun 96 - Version 3.0 by Eric S. Raymond (Full GIF89 support)
  49  * 17 Dec 98 - Version 4.0 by Toshio Kuratomi (Fix extension writing code)
  50  *****************************************************************************/
  51
  52 #ifndef _UNGIF_H_
  53 #define _UNGIF_H_ 1
  54
  55 #define GIF_ERROR   0
  56 #define GIF_OK      1
  57
  58 #ifndef TRUE
  59 #define TRUE        1
  60 #endif /* TRUE */
  61 #ifndef FALSE
  62 #define FALSE       0
  63 #endif /* FALSE */
  64
  65 #ifndef NULL
  66 #define NULL        0
  67 #endif /* NULL */
  68
  69 #define GIF_STAMP "GIFVER"          /* First chars in file - GIF stamp.  */
  70 #define GIF_STAMP_LEN sizeof(GIF_STAMP) - 1
  71 #define GIF_VERSION_POS 3           /* Version first character in stamp. */
  72 #define GIF87_STAMP "GIF87a"        /* First chars in file - GIF stamp.  */
  73 #define GIF89_STAMP "GIF89a"        /* First chars in file - GIF stamp.  */
  74
  75 #define GIF_FILE_BUFFER_SIZE 16384  /* Files uses bigger buffers than usual. */
  76
  77 typedef int GifBooleanType;
  78 typedef unsigned char GifPixelType;
  79 typedef unsigned char *GifRowType;
  80 typedef unsigned char GifByteType;
  81 typedef unsigned int GifPrefixType;
  82 typedef int GifWord;
  83
  84 typedef struct GifColorType {
  85     GifByteType Red, Green, Blue;
  86 } GifColorType;
  87
  88 typedef struct ColorMapObject {
  89     int ColorCount;
  90     int BitsPerPixel;
  91     int SortFlag;
  92     GifColorType *Colors;
  93 } ColorMapObject;
  94
  95 typedef struct GifImageDesc {
  96     GifWord Left, Top, Width, Height,   /* Current image dimensions. */
  97       Interlace;                    /* Sequential/Interlaced lines. */
  98     ColorMapObject *ColorMap;       /* The local color map */
  99 } GifImageDesc;
 100
 101 /* This is the in-core version of an extension record */
 102 typedef struct {
 103     int Function;   /* Holds the type of the Extension block. */
 104     int ByteCount;
 105     char *Bytes;
 106 } ExtensionBlock;
 107
 108 typedef struct {
 109     int Function;   /* DEPRECATED: Use ExtensionBlocks[x].Function instead */
 110     int ExtensionBlockCount;
 111     ExtensionBlock *ExtensionBlocks;
 112 } Extensions;
 113
 114 typedef struct GifFileType {
 115     GifWord SWidth, SHeight,        /* Screen dimensions. */
 116       SColorResolution,         /* How many colors can we generate? */
 117       SBackGroundColor,         /* I hope you understand this one... */
 118       SAspectRatio;             /* Pixel aspect ratio, in 1/64 units, starting at 1:4. */
 119     ColorMapObject *SColorMap;  /* NULL if not exists. */
 120     Extensions Extensions;
 121     int ImageCount;             /* Number of current image */
 122     GifImageDesc Image;         /* Block describing current image */
 123     struct SavedImage *SavedImages; /* Use this to accumulate file state */
 124     void *UserData;             /* hook to attach user data (TVT) */
 125     void *Private;              /* Don't mess with this! */
 126 } GifFileType;
 127
 128 typedef enum {
 129     UNDEFINED_RECORD_TYPE,
 130     SCREEN_DESC_RECORD_TYPE,
 131     IMAGE_DESC_RECORD_TYPE, /* Begin with ',' */
 132     EXTENSION_RECORD_TYPE,  /* Begin with '!' */
 133     TERMINATE_RECORD_TYPE   /* Begin with ';' */
 134 } GifRecordType;
 135
 136 /* func type to read gif data from arbitrary sources (TVT) */
 137 typedef int (*InputFunc) (GifFileType *, GifByteType *, int);
 138
 139 /*  GIF89 extension function codes */
 140
 141 #define COMMENT_EXT_FUNC_CODE     0xfe    /* comment */
 142 #define GRAPHICS_EXT_FUNC_CODE    0xf9    /* graphics control */
 143 #define PLAINTEXT_EXT_FUNC_CODE   0x01    /* plaintext */
 144 #define APPLICATION_EXT_FUNC_CODE 0xff    /* application block */
 145
 146 /* public interface to ungif.c */
 147 int DGifSlurp(GifFileType * GifFile) DECLSPEC_HIDDEN;
 148 GifFileType *DGifOpen(void *userPtr, InputFunc readFunc) DECLSPEC_HIDDEN;
 149 int DGifCloseFile(GifFileType * GifFile) DECLSPEC_HIDDEN;
 150
 151 #define D_GIF_ERR_OPEN_FAILED    101    /* And DGif possible errors. */
 152 #define D_GIF_ERR_READ_FAILED    102
 153 #define D_GIF_ERR_NOT_GIF_FILE   103
 154 #define D_GIF_ERR_NO_SCRN_DSCR   104
 155 #define D_GIF_ERR_NO_IMAG_DSCR   105
 156 #define D_GIF_ERR_NO_COLOR_MAP   106
 157 #define D_GIF_ERR_WRONG_RECORD   107
 158 #define D_GIF_ERR_DATA_TOO_BIG   108
 159 #define D_GIF_ERR_NOT_ENOUGH_MEM 109
 160 #define D_GIF_ERR_CLOSE_FAILED   110
 161 #define D_GIF_ERR_NOT_READABLE   111
 162 #define D_GIF_ERR_IMAGE_DEFECT   112
 163 #define D_GIF_ERR_EOF_TOO_SOON   113
 164
 165 /******************************************************************************
 166  * Support for the in-core structures allocation (slurp mode).
 167  *****************************************************************************/
 168
 169 /* This holds an image header, its unpacked raster bits, and extensions */
 170 typedef struct SavedImage {
 171     GifImageDesc ImageDesc;
 172     unsigned char *RasterBits;
 173     Extensions Extensions;
 174 } SavedImage;
 175
 176 #endif /* _UNGIF_H_ */