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 */ 310