1 /******************************************************************************
   2  
   3 gif_lib.h - service library for decoding and encoding GIF images
   4                                                                              
   5 *****************************************************************************/
   6 
   7 #ifndef _GIF_LIB_H_
   8 #define _GIF_LIB_H_ 1
   9 
  10 #ifdef __cplusplus
  11 extern "C" {
  12 #endif /* __cplusplus */
  13 
  14 #define GIFLIB_MAJOR 5
  15 #define GIFLIB_MINOR 1
  16 #define GIFLIB_RELEASE 1
  17 
  18 #define GIF_ERROR   0
  19 #define GIF_OK      1
  20 
  21 #include <stddef.h>
  22 #include <stdbool.h>






  23 
  24 #define GIF_STAMP "GIFVER"          /* First chars in file - GIF stamp.  */
  25 #define GIF_STAMP_LEN sizeof(GIF_STAMP) - 1
  26 #define GIF_VERSION_POS 3           /* Version first character in stamp. */
  27 #define GIF87_STAMP "GIF87a"        /* First chars in file - GIF stamp.  */
  28 #define GIF89_STAMP "GIF89a"        /* First chars in file - GIF stamp.  */
  29 
  30 typedef unsigned char GifPixelType;
  31 typedef unsigned char *GifRowType;
  32 typedef unsigned char GifByteType;
  33 typedef unsigned int GifPrefixType;
  34 typedef int GifWord;
  35 
  36 typedef struct GifColorType {
  37     GifByteType Red, Green, Blue;
  38 } GifColorType;
  39 
  40 typedef struct ColorMapObject {
  41     int ColorCount;
  42     int BitsPerPixel;
  43     bool SortFlag;
  44     GifColorType *Colors;    /* on malloc(3) heap */
  45 } ColorMapObject;
  46 
  47 typedef struct GifImageDesc {
  48     GifWord Left, Top, Width, Height;   /* Current image dimensions. */
  49     bool Interlace;                     /* Sequential/Interlaced lines. */
  50     ColorMapObject *ColorMap;           /* The local color map */
  51 } GifImageDesc;
  52 
  53 typedef struct ExtensionBlock {
  54     int ByteCount;
  55     GifByteType *Bytes; /* on malloc(3) heap */
  56     int Function;       /* The block function code */
  57 #define CONTINUE_EXT_FUNC_CODE    0x00    /* continuation subblock */
  58 #define COMMENT_EXT_FUNC_CODE     0xfe    /* comment */
  59 #define GRAPHICS_EXT_FUNC_CODE    0xf9    /* graphics control (GIF89) */
  60 #define PLAINTEXT_EXT_FUNC_CODE   0x01    /* plaintext */
  61 #define APPLICATION_EXT_FUNC_CODE 0xff    /* application block */
  62 } ExtensionBlock;
  63 
  64 typedef struct SavedImage {
  65     GifImageDesc ImageDesc;
  66     GifByteType *RasterBits;         /* on malloc(3) heap */
  67     int ExtensionBlockCount;         /* Count of extensions before image */    
  68     ExtensionBlock *ExtensionBlocks; /* Extensions before image */    
  69 } SavedImage;
  70 
  71 typedef struct GifFileType {
  72     GifWord SWidth, SHeight;         /* Size of virtual canvas */
  73     GifWord SColorResolution;        /* How many colors can we generate? */
  74     GifWord SBackGroundColor;        /* Background color for virtual canvas */
  75     GifByteType AspectByte;          /* Used to compute pixel aspect ratio */
  76     ColorMapObject *SColorMap;       /* Global colormap, NULL if nonexistent. */
  77     int ImageCount;                  /* Number of current image (both APIs) */
  78     GifImageDesc Image;              /* Current image (low-level API) */
  79     SavedImage *SavedImages;         /* Image sequence (high-level API) */
  80     int ExtensionBlockCount;         /* Count extensions past last image */
  81     ExtensionBlock *ExtensionBlocks; /* Extensions past last image */    
  82     int Error;                       /* Last error condition reported */
  83     void *UserData;                  /* hook to attach user data (TVT) */
  84     void *Private;                   /* Don't mess with this! */
  85 } GifFileType;
  86 
  87 #define GIF_ASPECT_RATIO(n)     ((n)+15.0/64.0)
  88 
  89 typedef enum {
  90     UNDEFINED_RECORD_TYPE,
  91     SCREEN_DESC_RECORD_TYPE,
  92     IMAGE_DESC_RECORD_TYPE, /* Begin with ',' */
  93     EXTENSION_RECORD_TYPE,  /* Begin with '!' */
  94     TERMINATE_RECORD_TYPE   /* Begin with ';' */
  95 } GifRecordType;
  96 
  97 /* func type to read gif data from arbitrary sources (TVT) */
  98 typedef int (*InputFunc) (GifFileType *, GifByteType *, int);
  99 
 100 /* func type to write gif data to arbitrary targets.
 101  * Returns count of bytes written. (MRB)
 102  */
 103 typedef int (*OutputFunc) (GifFileType *, const GifByteType *, int);
 104 
 105 /******************************************************************************
 106  GIF89 structures
 107 ******************************************************************************/
 108 
 109 typedef struct GraphicsControlBlock {
 110     int DisposalMode;
 111 #define DISPOSAL_UNSPECIFIED      0       /* No disposal specified. */
 112 #define DISPOSE_DO_NOT            1       /* Leave image in place */
 113 #define DISPOSE_BACKGROUND        2       /* Set area too background color */
 114 #define DISPOSE_PREVIOUS          3       /* Restore to previous content */
 115     bool UserInputFlag;      /* User confirmation required before disposal */
 116     int DelayTime;           /* pre-display delay in 0.01sec units */
 117     int TransparentColor;    /* Palette index for transparency, -1 if none */
 118 #define NO_TRANSPARENT_COLOR    -1
 119 } GraphicsControlBlock;
 120 
 121 /******************************************************************************
 122  GIF encoding routines
 123 ******************************************************************************/
 124 
 125 /* Main entry points */
 126 GifFileType *EGifOpenFileName(const char *GifFileName,
 127                               const bool GifTestExistence, int *Error);
 128 GifFileType *EGifOpenFileHandle(const int GifFileHandle, int *Error);
 129 GifFileType *EGifOpen(void *userPtr, OutputFunc writeFunc, int *Error);
 130 int EGifSpew(GifFileType * GifFile);
 131 const char *EGifGetGifVersion(GifFileType *GifFile); /* new in 5.x */
 132 int EGifCloseFile(GifFileType *GifFile, int *ErrorCode);
 133 
 134 #define E_GIF_SUCCEEDED          0
 135 #define E_GIF_ERR_OPEN_FAILED    1    /* And EGif possible errors. */
 136 #define E_GIF_ERR_WRITE_FAILED   2
 137 #define E_GIF_ERR_HAS_SCRN_DSCR  3
 138 #define E_GIF_ERR_HAS_IMAG_DSCR  4
 139 #define E_GIF_ERR_NO_COLOR_MAP   5
 140 #define E_GIF_ERR_DATA_TOO_BIG   6
 141 #define E_GIF_ERR_NOT_ENOUGH_MEM 7
 142 #define E_GIF_ERR_DISK_IS_FULL   8
 143 #define E_GIF_ERR_CLOSE_FAILED   9
 144 #define E_GIF_ERR_NOT_WRITEABLE  10
 145 
 146 /* These are legacy.  You probably do not want to call them directly */
 147 int EGifPutScreenDesc(GifFileType *GifFile,
 148                       const int GifWidth, const int GifHeight, 
 149                       const int GifColorRes,
 150                       const int GifBackGround,
 151                       const ColorMapObject *GifColorMap);
 152 int EGifPutImageDesc(GifFileType *GifFile, 
 153                      const int GifLeft, const int GifTop,
 154                      const int GifWidth, const int GifHeight, 
 155                      const bool GifInterlace,
 156                      const ColorMapObject *GifColorMap);
 157 void EGifSetGifVersion(GifFileType *GifFile, const bool gif89);
 158 int EGifPutLine(GifFileType *GifFile, GifPixelType *GifLine,
 159                 int GifLineLen);
 160 int EGifPutPixel(GifFileType *GifFile, const GifPixelType GifPixel);
 161 int EGifPutComment(GifFileType *GifFile, const char *GifComment);
 162 int EGifPutExtensionLeader(GifFileType *GifFile, const int GifExtCode);
 163 int EGifPutExtensionBlock(GifFileType *GifFile,
 164                          const int GifExtLen, const void *GifExtension);
 165 int EGifPutExtensionTrailer(GifFileType *GifFile);
 166 int EGifPutExtension(GifFileType *GifFile, const int GifExtCode, 
 167                      const int GifExtLen,
 168                      const void *GifExtension);
 169 int EGifPutCode(GifFileType *GifFile, int GifCodeSize,
 170                 const GifByteType *GifCodeBlock);
 171 int EGifPutCodeNext(GifFileType *GifFile,
 172                     const GifByteType *GifCodeBlock);
 173 
 174 /******************************************************************************
 175  GIF decoding routines
 176 ******************************************************************************/
 177 
 178 /* Main entry points */
 179 GifFileType *DGifOpenFileName(const char *GifFileName, int *Error);
 180 GifFileType *DGifOpenFileHandle(int GifFileHandle, int *Error);
 181 int DGifSlurp(GifFileType * GifFile);
 182 GifFileType *DGifOpen(void *userPtr, InputFunc readFunc, int *Error);    /* new one (TVT) */
 183     int DGifCloseFile(GifFileType * GifFile, int *ErrorCode);
 184 
 185 #define D_GIF_SUCCEEDED          0
 186 #define D_GIF_ERR_OPEN_FAILED    101    /* And DGif possible errors. */
 187 #define D_GIF_ERR_READ_FAILED    102
 188 #define D_GIF_ERR_NOT_GIF_FILE   103
 189 #define D_GIF_ERR_NO_SCRN_DSCR   104
 190 #define D_GIF_ERR_NO_IMAG_DSCR   105
 191 #define D_GIF_ERR_NO_COLOR_MAP   106
 192 #define D_GIF_ERR_WRONG_RECORD   107
 193 #define D_GIF_ERR_DATA_TOO_BIG   108
 194 #define D_GIF_ERR_NOT_ENOUGH_MEM 109
 195 #define D_GIF_ERR_CLOSE_FAILED   110
 196 #define D_GIF_ERR_NOT_READABLE   111
 197 #define D_GIF_ERR_IMAGE_DEFECT   112
 198 #define D_GIF_ERR_EOF_TOO_SOON   113
 199 
 200 /* These are legacy.  You probably do not want to call them directly */
 201 int DGifGetScreenDesc(GifFileType *GifFile);
 202 int DGifGetRecordType(GifFileType *GifFile, GifRecordType *GifType);
 203 int DGifGetImageDesc(GifFileType *GifFile);
 204 int DGifGetLine(GifFileType *GifFile, GifPixelType *GifLine, int GifLineLen);
 205 int DGifGetPixel(GifFileType *GifFile, GifPixelType GifPixel);
 206 int DGifGetComment(GifFileType *GifFile, char *GifComment);
 207 int DGifGetExtension(GifFileType *GifFile, int *GifExtCode,
 208                      GifByteType **GifExtension);
 209 int DGifGetExtensionNext(GifFileType *GifFile, GifByteType **GifExtension);
 210 int DGifGetCode(GifFileType *GifFile, int *GifCodeSize,
 211                 GifByteType **GifCodeBlock);
 212 int DGifGetCodeNext(GifFileType *GifFile, GifByteType **GifCodeBlock);
 213 int DGifGetLZCodes(GifFileType *GifFile, int *GifCode);
 214 
 215 
 216 /******************************************************************************
 217  Color table quantization (deprecated)
 218 ******************************************************************************/
 219 int GifQuantizeBuffer(unsigned int Width, unsigned int Height,
 220                    int *ColorMapSize, GifByteType * RedInput,
 221                    GifByteType * GreenInput, GifByteType * BlueInput,
 222                    GifByteType * OutputBuffer,
 223                    GifColorType * OutputColorMap);
 224 
 225 /******************************************************************************
 226  Error handling and reporting.
 227 ******************************************************************************/
 228 extern const char *GifErrorString(int ErrorCode);     /* new in 2012 - ESR */
 229 
 230 /*****************************************************************************
 231  Everything below this point is new after version 1.2, supporting `slurp
 232  mode' for doing I/O in two big belts with all the image-bashing in core.
 233 ******************************************************************************/
 234 
 235 /******************************************************************************
 236  Color map handling from gif_alloc.c
 237 ******************************************************************************/
 238 
 239 extern ColorMapObject *GifMakeMapObject(int ColorCount,
 240                                      const GifColorType *ColorMap);
 241 extern void GifFreeMapObject(ColorMapObject *Object);
 242 extern ColorMapObject *GifUnionColorMap(const ColorMapObject *ColorIn1,
 243                                      const ColorMapObject *ColorIn2,
 244                                      GifPixelType ColorTransIn2[]);
 245 extern int GifBitSize(int n);
 246 
 247 /******************************************************************************
 248  Support for the in-core structures allocation (slurp mode).              
 249 ******************************************************************************/
 250 
 251 extern void GifApplyTranslation(SavedImage *Image, GifPixelType Translation[]);
 252 extern int GifAddExtensionBlock(int *ExtensionBlock_Count,
 253                                 ExtensionBlock **ExtensionBlocks, 
 254                                 int Function, 
 255                                 unsigned int Len, unsigned char ExtData[]);
 256 extern void GifFreeExtensions(int *ExtensionBlock_Count,
 257                               ExtensionBlock **ExtensionBlocks);
 258 extern SavedImage *GifMakeSavedImage(GifFileType *GifFile,
 259                                   const SavedImage *CopyFrom);
 260 extern void GifFreeSavedImages(GifFileType *GifFile);
 261 
 262 /******************************************************************************
 263  5.x functions for GIF89 graphics control blocks
 264 ******************************************************************************/
 265 
 266 int DGifExtensionToGCB(const size_t GifExtensionLength,
 267                        const GifByteType *GifExtension,
 268                        GraphicsControlBlock *GCB);
 269 size_t EGifGCBToExtension(const GraphicsControlBlock *GCB,
 270                        GifByteType *GifExtension);
 271 
 272 int DGifSavedExtensionToGCB(GifFileType *GifFile, 
 273                             int ImageIndex, 
 274                             GraphicsControlBlock *GCB);
 275 int EGifGCBToSavedExtension(const GraphicsControlBlock *GCB, 
 276                             GifFileType *GifFile, 
 277                             int ImageIndex);
 278 
 279 /******************************************************************************
 280  The library's internal utility font                          
 281 ******************************************************************************/
 282 
 283 #define GIF_FONT_WIDTH  8
 284 #define GIF_FONT_HEIGHT 8
 285 extern const unsigned char GifAsciiTable8x8[][GIF_FONT_WIDTH];
 286 
 287 extern void GifDrawText8x8(SavedImage *Image,
 288                      const int x, const int y,
 289                      const char *legend, const int color);
 290 
 291 extern void GifDrawBox(SavedImage *Image,
 292                     const int x, const int y,
 293                     const int w, const int d, const int color);
 294 
 295 extern void GifDrawRectangle(SavedImage *Image,
 296                    const int x, const int y,
 297                    const int w, const int d, const int color);
 298 
 299 extern void GifDrawBoxedText8x8(SavedImage *Image,
 300                           const int x, const int y,
 301                           const char *legend,
 302                           const int border, const int bg, const int fg);
 303 
 304 #ifdef __cplusplus
 305 }
 306 #endif /* __cplusplus */
 307 #endif /* _GIF_LIB_H */
 308 
 309 /* end */
--- EOF ---