428
+ − 1 /******************************************************************************
+ − 2 * In order to make life a little bit easier when using the GIF file format, *
+ − 3 * this library was written, and which does all the dirty work... *
+ − 4 * *
+ − 5 * Written by Gershon Elber, Jun. 1989 *
+ − 6 * Hacks by Eric S. Raymond, Sep. 1992 *
+ − 7 * and Jareth Hein, Jan. 1998 *
+ − 8 *******************************************************************************
+ − 9 * History: *
+ − 10 * 14 Jun 89 - Version 1.0 by Gershon Elber. *
+ − 11 * 3 Sep 90 - Version 1.1 by Gershon Elber (Support for Gif89, Unique names). *
+ − 12 * 15 Sep 90 - Version 2.0 by Eric S. Raymond (Changes to suoport GIF slurp) *
+ − 13 * 26 Jun 96 - Version 3.0 by Eric S. Raymond (Full GIF89 support) *
+ − 14 * 19 Jan 98 - Version 3.1 by Jareth Hein (Support for user-defined I/O). *
+ − 15 ******************************************************************************/
+ − 16
440
+ − 17 #ifndef INCLUDED_gifrlib_h_
+ − 18 #define INCLUDED_gifrlib_h_
428
+ − 19
+ − 20 #define GIF_ERROR 0
+ − 21 #define GIF_OK 1
+ − 22
+ − 23 #ifndef TRUE
+ − 24 #define TRUE 1
+ − 25 #define FALSE 0
+ − 26 #endif
+ − 27
+ − 28 #ifndef NULL
+ − 29 #define NULL 0
+ − 30 #endif /* NULL */
+ − 31
+ − 32 #define GIF_FILE_BUFFER_SIZE 16384 /* Files uses bigger buffers than usual. */
+ − 33
+ − 34 typedef int GifBooleanType;
+ − 35 typedef unsigned char GifPixelType;
+ − 36 typedef unsigned char * GifRowType;
+ − 37 typedef unsigned char GifByteType;
+ − 38
+ − 39 #define VoidPtr void *
+ − 40
+ − 41 typedef struct GifColorType {
+ − 42 GifByteType Red, Green, Blue;
+ − 43 } GifColorType;
+ − 44
+ − 45 typedef struct ColorMapObject
+ − 46 {
+ − 47 int ColorCount;
+ − 48 int BitsPerPixel;
+ − 49 GifColorType *Colors; /* on malloc(3) heap */
+ − 50 }
+ − 51 ColorMapObject;
+ − 52
+ − 53 typedef struct GifImageDesc {
+ − 54 int Left, Top, Width, Height, /* Current image dimensions. */
+ − 55 Interlace; /* Sequential/Interlaced lines. */
+ − 56 ColorMapObject *ColorMap; /* The local color map */
+ − 57 } GifImageDesc;
+ − 58
+ − 59 /* I/O operations. If you roll your own, they need to be semantically equivilent to
+ − 60 fread/fwrite, with an additional paramater to hold data local to your method. */
665
+ − 61 typedef Bytecount (*Gif_rw_func)(GifByteType *buffer, Bytecount size, VoidPtr method_data);
428
+ − 62 /* Finish up stream. Non-zero return indicates failure */
+ − 63 typedef int (*Gif_close_func)(VoidPtr close_data);
+ − 64 /* Error handling function */
+ − 65 typedef void (*Gif_error_func)(const char *string, VoidPtr error_data);
+ − 66
+ − 67 typedef struct GifFileType {
+ − 68 int SWidth, SHeight, /* Screen dimensions. */
+ − 69 SColorResolution, /* How many colors can we generate? */
+ − 70 SBackGroundColor; /* I hope you understand this one... */
+ − 71 ColorMapObject *SColorMap; /* NULL if it doesn't exist. */
+ − 72 int ImageCount; /* Number of current image */
+ − 73 GifImageDesc Image; /* Block describing current image */
+ − 74 struct SavedImage *SavedImages; /* Use this to accumulate file state */
+ − 75 VoidPtr Private; /* Don't mess with this! */
+ − 76 VoidPtr GifIO; /* Contains all information for I/O */
+ − 77 } GifFileType;
+ − 78
+ − 79 typedef enum {
+ − 80 UNDEFINED_RECORD_TYPE,
+ − 81 SCREEN_DESC_RECORD_TYPE,
+ − 82 IMAGE_DESC_RECORD_TYPE, /* Begin with ',' */
+ − 83 EXTENSION_RECORD_TYPE, /* Begin with '!' */
+ − 84 TERMINATE_RECORD_TYPE /* Begin with ';' */
+ − 85 } GifRecordType;
+ − 86
+ − 87 /******************************************************************************
+ − 88 * GIF89 extension function codes *
+ − 89 ******************************************************************************/
+ − 90
+ − 91 #define COMMENT_EXT_FUNC_CODE 0xfe /* comment */
+ − 92 #define GRAPHICS_EXT_FUNC_CODE 0xf9 /* graphics control */
+ − 93 #define PLAINTEXT_EXT_FUNC_CODE 0x01 /* plaintext */
+ − 94 #define APPLICATION_EXT_FUNC_CODE 0xff /* application block */
+ − 95
+ − 96 /******************************************************************************
+ − 97 * IO related routines. Defined in gif_io.c *
+ − 98 ******************************************************************************/
+ − 99 GifFileType *GifSetup(void);
+ − 100 void GifFree(GifFileType *GifFile);
+ − 101 void GifSetReadFunc (GifFileType *GifFile, Gif_rw_func func, VoidPtr data);
+ − 102 void GifSetWriteFunc(GifFileType *GifFile, Gif_rw_func func, VoidPtr data);
+ − 103 void GifSetCloseFunc(GifFileType *GifFile, Gif_close_func func, VoidPtr data);
+ − 104
+ − 105 /******************************************************************************
+ − 106 * O.K., here are the routines one can access in order to decode GIF file: *
+ − 107 ******************************************************************************/
+ − 108
+ − 109 void DGifOpenFileName(GifFileType *GifFile, const char *GifFileName);
+ − 110 void DGifOpenFileHandle(GifFileType *GifFile, int GifFileHandle);
+ − 111 void DGifInitRead(GifFileType *GifFile);
+ − 112 void DGifSlurp(GifFileType *GifFile);
+ − 113 void DGifGetScreenDesc(GifFileType *GifFile);
+ − 114 void DGifGetRecordType(GifFileType *GifFile, GifRecordType *GifType);
+ − 115 void DGifGetImageDesc(GifFileType *GifFile);
+ − 116 void DGifGetLine(GifFileType *GifFile, GifPixelType *GifLine, int GifLineLen);
+ − 117 void DGifGetPixel(GifFileType *GifFile, GifPixelType GifPixel);
+ − 118 void DGifGetComment(GifFileType *GifFile, char *GifComment);
+ − 119 void DGifGetExtension(GifFileType *GifFile, int *GifExtCode,
+ − 120 GifByteType **GifExtension);
+ − 121 void DGifGetExtensionNext(GifFileType *GifFile, GifByteType **GifExtension);
+ − 122 void DGifGetCode(GifFileType *GifFile, int *GifCodeSize,
+ − 123 GifByteType **GifCodeBlock);
+ − 124 void DGifGetCodeNext(GifFileType *GifFile, GifByteType **GifCodeBlock);
+ − 125 void DGifGetLZCodes(GifFileType *GifFile, int *GifCode);
+ − 126 int DGifCloseFile(GifFileType *GifFile);
+ − 127
+ − 128 #define D_GIF_ERR_OPEN_FAILED 101 /* And DGif possible errors. */
+ − 129 #define D_GIF_ERR_READ_FAILED 102
+ − 130 #define D_GIF_ERR_NOT_GIF_FILE 103
+ − 131 #define D_GIF_ERR_NO_SCRN_DSCR 104
+ − 132 #define D_GIF_ERR_NO_IMAG_DSCR 105
+ − 133 #define D_GIF_ERR_NO_COLOR_MAP 106
+ − 134 #define D_GIF_ERR_WRONG_RECORD 107
+ − 135 #define D_GIF_ERR_DATA_TOO_BIG 108
+ − 136 #define GIF_ERR_NOT_ENOUGH_MEM 109
+ − 137 #define D_GIF_ERR_NOT_ENOUGH_MEM 109
+ − 138 #define D_GIF_ERR_CLOSE_FAILED 110
+ − 139 #define D_GIF_ERR_NOT_READABLE 111
+ − 140 #define D_GIF_ERR_IMAGE_DEFECT 112
+ − 141 #define D_GIF_ERR_EOF_TOO_SOON 113
+ − 142
+ − 143 /******************************************************************************
+ − 144 * O.K., here are the error routines *
+ − 145 ******************************************************************************/
+ − 146 extern void GifSetErrorFunc(GifFileType *GifFile, Gif_error_func func, VoidPtr data);
+ − 147 extern void GifSetWarningFunc(GifFileType *GifFile, Gif_error_func func, VoidPtr data);
+ − 148 extern void GifInternError(GifFileType *GifFile, int errnum);
+ − 149 extern void GifInternWarning(GifFileType *GifFile, int errnum);
+ − 150 extern void GifError(GifFileType *GifFile, const char *err_str);
+ − 151 extern void GifWarning(GifFileType *GifFile, const char *err_str);
+ − 152
+ − 153 /*****************************************************************************
+ − 154 *
+ − 155 * Everything below this point is new after version 1.2, supporting `slurp
+ − 156 * mode' for doing I/O in two big belts with all the image-bashing in core.
+ − 157 *
+ − 158 *****************************************************************************/
+ − 159
+ − 160 /******************************************************************************
+ − 161 * Support for the in-core structures allocation (slurp mode). *
+ − 162 ******************************************************************************/
+ − 163
+ − 164 /* This is the in-core version of an extension record */
+ − 165 typedef struct {
+ − 166 int ByteCount;
+ − 167 GifByteType *Bytes; /* on malloc(3) heap */
+ − 168 } ExtensionBlock;
+ − 169
+ − 170 /* This holds an image header, its unpacked raster bits, and extensions */
+ − 171 typedef struct SavedImage {
+ − 172 GifImageDesc ImageDesc;
+ − 173
+ − 174 GifPixelType *RasterBits; /* on malloc(3) heap */
+ − 175
+ − 176 int Function;
+ − 177 int ExtensionBlockCount;
+ − 178 ExtensionBlock *ExtensionBlocks; /* on malloc(3) heap */
+ − 179 } SavedImage;
+ − 180
+ − 181 extern void ApplyTranslation(SavedImage *Image, GifPixelType Translation[]);
+ − 182
+ − 183 extern void MakeExtension(SavedImage *New, int Function);
+ − 184 extern int AddExtensionBlock(SavedImage *New, int Length, GifByteType *data);
+ − 185 extern void FreeExtension(SavedImage *Image);
+ − 186
+ − 187 extern SavedImage *MakeSavedImage(GifFileType *GifFile, SavedImage *CopyFrom);
+ − 188 extern void FreeSavedImages(GifFileType *GifFile);
+ − 189
+ − 190 /* Common defines used by encode/decode functions */
+ − 191
+ − 192 #define COMMENT_EXT_FUNC_CODE 0xfe /* Extension function code for comment. */
+ − 193 #define GIF_STAMP "GIFVER" /* First chars in file - GIF stamp. */
+ − 194 #define GIF_STAMP_LEN sizeof(GIF_STAMP) - 1
+ − 195 #define GIF_VERSION_POS 3 /* Version first character in stamp. */
+ − 196 #define GIF87_STAMP "GIF87a" /* First chars in file - GIF stamp. */
+ − 197 #define GIF89_STAMP "GIF89a" /* First chars in file - GIF stamp. */
+ − 198
+ − 199 #define LZ_MAX_CODE 4095 /* Biggest code possible in 12 bits. */
+ − 200 #define LZ_BITS 12
+ − 201
+ − 202 #define FILE_STATE_READ 0x01
+ − 203 #define FILE_STATE_WRITE 0x01
+ − 204 #define FILE_STATE_SCREEN 0x02
+ − 205 #define FILE_STATE_IMAGE 0x04
+ − 206
+ − 207 #define FLUSH_OUTPUT 4096 /* Impossible code, to signal flush. */
+ − 208 #define FIRST_CODE 4097 /* Impossible code, to signal first. */
+ − 209 #define NO_SUCH_CODE 4098 /* Impossible code, to signal empty. */
+ − 210
+ − 211 #define IS_READABLE(Private) (!(Private->FileState & FILE_STATE_READ))
+ − 212 #define IS_WRITEABLE(Private) (Private->FileState & FILE_STATE_WRITE)
+ − 213
+ − 214 typedef struct GifFilePrivateType {
+ − 215 int FileState,
+ − 216 BitsPerPixel, /* Bits per pixel (Codes uses at list this + 1). */
+ − 217 ClearCode, /* The CLEAR LZ code. */
+ − 218 EOFCode, /* The EOF LZ code. */
+ − 219 RunningCode, /* The next code algorithm can generate. */
+ − 220 RunningBits,/* The number of bits required to represent RunningCode. */
+ − 221 MaxCode1, /* 1 bigger than max. possible code, in RunningBits bits. */
+ − 222 LastCode, /* The code before the current code. */
+ − 223 CrntCode, /* Current algorithm code. */
+ − 224 StackPtr, /* For character stack (see below). */
+ − 225 CrntShiftState; /* Number of bits in CrntShiftDWord. */
+ − 226 unsigned long CrntShiftDWord; /* For bytes decomposition into codes. */
+ − 227 unsigned long PixelCount; /* Number of pixels in image. */
+ − 228 GifByteType Buf[256]; /* Compressed input is buffered here. */
+ − 229 GifByteType Stack[LZ_MAX_CODE]; /* Decoded pixels are stacked here. */
+ − 230 GifByteType Suffix[LZ_MAX_CODE+1]; /* So we can trace the codes. */
+ − 231 unsigned int Prefix[LZ_MAX_CODE+1];
+ − 232 } GifFilePrivateType;
+ − 233
+ − 234 typedef struct GifIODataType {
+ − 235 Gif_rw_func ReadFunc, WriteFunc; /* Pointers to the functions that will do the I/O */
+ − 236 Gif_close_func CloseFunc;
+ − 237 VoidPtr ReadFunc_data; /* data to be passed to the read function */
+ − 238 VoidPtr WriteFunc_data; /* data to be passed to the write function */
+ − 239 VoidPtr CloseFunc_data; /* data to be passed to the close function */
+ − 240 Gif_error_func ErrorFunc; /* MUST NOT RETURN (use lng_jmp or exit)! */
+ − 241 Gif_error_func WarningFunc; /* For warning messages (can be ignored) */
+ − 242 VoidPtr ErrorFunc_data;
+ − 243 VoidPtr WarningFunc_data;
+ − 244 } GifIODataType;
+ − 245
+ − 246 typedef struct GifStdIODataType {
+ − 247 FILE *File;
+ − 248 int FileHandle;
+ − 249 } GifStdIODataType;
+ − 250
+ − 251 /* Install StdIO funcs on FILE into GifFile */
+ − 252 void GifStdIOInit(GifFileType *GifFile, FILE *file, int filehandle);
+ − 253
+ − 254 /* Error checking reads, writes and closes */
665
+ − 255 void GifRead(GifByteType *buf, Bytecount size, GifFileType *GifFile);
+ − 256 void GifWrite(GifByteType *buf, Bytecount size, GifFileType *GifFile);
428
+ − 257 int GifClose(GifFileType *GifFile);
+ − 258
+ − 259 /* The default Read and Write functions for files */
665
+ − 260 Bytecount GifStdRead(GifByteType *buf, Bytecount size, VoidPtr method_data);
+ − 261 Bytecount GifStdWrite(GifByteType *buf, Bytecount size, VoidPtr method_data);
428
+ − 262 int GifStdFileClose(VoidPtr method_data);
+ − 263
+ − 264 ColorMapObject *MakeMapObject(int ColorCount, GifColorType *ColorMap);
+ − 265 void FreeMapObject(ColorMapObject *Object);
+ − 266
440
+ − 267 #endif /* INCLUDED_gifrlib_h_ */
