1 /****************************************************************************** 2 3 gif_lib.h - service library for decoding and encoding GIF images 4 5 SPDX-License-Identifier: MIT 6 7 *****************************************************************************/ 8 9 #ifndef _GIF_LIB_H_ 10 #define _GIF_LIB_H_ 1 11 12 #ifdef __cplusplus 13 extern "C" { 14 #endif /* __cplusplus */ 15 16 #define GIFLIB_MAJOR 5 17 #define GIFLIB_MINOR 2 18 #define GIFLIB_RELEASE 1 19 20 #define GIF_ERROR 0 21 #define GIF_OK 1 22 23 #include <stdbool.h> 24 #include <stddef.h> 25 26 #define GIF_STAMP "GIFVER" /* First chars in file - GIF stamp. */ 27 #define GIF_STAMP_LEN sizeof(GIF_STAMP) - 1 28 #define GIF_VERSION_POS 3 /* Version first character in stamp. */ 29 #define GIF87_STAMP "GIF87a" /* First chars in file - GIF stamp. */ 30 #define GIF89_STAMP "GIF89a" /* First chars in file - GIF stamp. */ 31 32 typedef unsigned char GifPixelType; 33 typedef unsigned char *GifRowType; 34 typedef unsigned char GifByteType; 35 typedef unsigned int GifPrefixType; 36 typedef int GifWord; 37 38 typedef struct GifColorType { 39 GifByteType Red, Green, Blue; 40 } GifColorType; 41 42 typedef struct ColorMapObject { 43 int ColorCount; 44 int BitsPerPixel; 45 bool SortFlag; 46 GifColorType *Colors; /* on malloc(3) heap */ 47 } ColorMapObject; 48 49 typedef struct GifImageDesc { 50 GifWord Left, Top, Width, Height; /* Current image dimensions. */ 51 bool Interlace; /* Sequential/Interlaced lines. */ 52 ColorMapObject *ColorMap; /* The local color map */ 53 } GifImageDesc; 54 55 typedef struct ExtensionBlock { 56 int ByteCount; 57 GifByteType *Bytes; /* on malloc(3) heap */ 58 int Function; /* The block function code */ 59 #define CONTINUE_EXT_FUNC_CODE 0x00 /* continuation subblock */ 60 #define COMMENT_EXT_FUNC_CODE 0xfe /* comment */ 61 #define GRAPHICS_EXT_FUNC_CODE 0xf9 /* graphics control (GIF89) */ 62 #define PLAINTEXT_EXT_FUNC_CODE 0x01 /* plaintext */ 63 #define APPLICATION_EXT_FUNC_CODE 0xff /* application block (GIF89) */ 64 } ExtensionBlock; 65 66 typedef struct SavedImage { 67 GifImageDesc ImageDesc; 68 GifByteType *RasterBits; /* on malloc(3) heap */ 69 int ExtensionBlockCount; /* Count of extensions before image */ 70 ExtensionBlock *ExtensionBlocks; /* Extensions before image */ 71 } SavedImage; 72 73 typedef struct GifFileType { 74 GifWord SWidth, SHeight; /* Size of virtual canvas */ 75 GifWord SColorResolution; /* How many colors can we generate? */ 76 GifWord SBackGroundColor; /* Background color for virtual canvas */ 77 GifByteType AspectByte; /* Used to compute pixel aspect ratio */ 78 ColorMapObject *SColorMap; /* Global colormap, NULL if nonexistent. */ 79 int ImageCount; /* Number of current image (both APIs) */ 80 GifImageDesc Image; /* Current image (low-level API) */ 81 SavedImage *SavedImages; /* Image sequence (high-level API) */ 82 int ExtensionBlockCount; /* Count extensions past last image */ 83 ExtensionBlock *ExtensionBlocks; /* Extensions past last image */ 84 int Error; /* Last error condition reported */ 85 void *UserData; /* hook to attach user data (TVT) */ 86 void *Private; /* Don't mess with this! */ 87 } GifFileType; 88 89 #define GIF_ASPECT_RATIO(n) ((n) + 15.0 / 64.0) 90 91 typedef enum { 92 UNDEFINED_RECORD_TYPE, 93 SCREEN_DESC_RECORD_TYPE, 94 IMAGE_DESC_RECORD_TYPE, /* Begin with ',' */ 95 EXTENSION_RECORD_TYPE, /* Begin with '!' */ 96 TERMINATE_RECORD_TYPE /* Begin with ';' */ 97 } GifRecordType; 98 99 /* func type to read gif data from arbitrary sources (TVT) */ 100 typedef int (*InputFunc)(GifFileType *, GifByteType *, int); 101 102 /* func type to write gif data to arbitrary targets. 103 * Returns count of bytes written. (MRB) 104 */ 105 typedef int (*OutputFunc)(GifFileType *, const GifByteType *, int); 106 107 /****************************************************************************** 108 GIF89 structures 109 ******************************************************************************/ 110 111 typedef struct GraphicsControlBlock { 112 int DisposalMode; 113 #define DISPOSAL_UNSPECIFIED 0 /* No disposal specified. */ 114 #define DISPOSE_DO_NOT 1 /* Leave image in place */ 115 #define DISPOSE_BACKGROUND 2 /* Set area too background color */ 116 #define DISPOSE_PREVIOUS 3 /* Restore to previous content */ 117 bool UserInputFlag; /* User confirmation required before disposal */ 118 int DelayTime; /* pre-display delay in 0.01sec units */ 119 int TransparentColor; /* Palette index for transparency, -1 if none */ 120 #define NO_TRANSPARENT_COLOR -1 121 } GraphicsControlBlock; 122 123 /****************************************************************************** 124 GIF encoding routines 125 ******************************************************************************/ 126 127 /* Main entry points */ 128 GifFileType *EGifOpenFileName(const char *GifFileName, 129 const bool GifTestExistence, int *Error); 130 GifFileType *EGifOpenFileHandle(const int GifFileHandle, int *Error); 131 GifFileType *EGifOpen(void *userPtr, OutputFunc writeFunc, int *Error); 132 int EGifSpew(GifFileType *GifFile); 133 const char *EGifGetGifVersion(GifFileType *GifFile); /* new in 5.x */ 134 int EGifCloseFile(GifFileType *GifFile, int *ErrorCode); 135 136 #define E_GIF_SUCCEEDED 0 137 #define E_GIF_ERR_OPEN_FAILED 1 /* And EGif possible errors. */ 138 #define E_GIF_ERR_WRITE_FAILED 2 139 #define E_GIF_ERR_HAS_SCRN_DSCR 3 140 #define E_GIF_ERR_HAS_IMAG_DSCR 4 141 #define E_GIF_ERR_NO_COLOR_MAP 5 142 #define E_GIF_ERR_DATA_TOO_BIG 6 143 #define E_GIF_ERR_NOT_ENOUGH_MEM 7 144 #define E_GIF_ERR_DISK_IS_FULL 8 145 #define E_GIF_ERR_CLOSE_FAILED 9 146 #define E_GIF_ERR_NOT_WRITEABLE 10 147 148 /* These are legacy. You probably do not want to call them directly */ 149 int EGifPutScreenDesc(GifFileType *GifFile, const int GifWidth, 150 const int GifHeight, const int GifColorRes, 151 const int GifBackGround, 152 const ColorMapObject *GifColorMap); 153 int EGifPutImageDesc(GifFileType *GifFile, 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, int GifLineLen); 159 int EGifPutPixel(GifFileType *GifFile, const GifPixelType GifPixel); 160 int EGifPutComment(GifFileType *GifFile, const char *GifComment); 161 int EGifPutExtensionLeader(GifFileType *GifFile, const int GifExtCode); 162 int EGifPutExtensionBlock(GifFileType *GifFile, const int GifExtLen, 163 const void *GifExtension); 164 int EGifPutExtensionTrailer(GifFileType *GifFile); 165 int EGifPutExtension(GifFileType *GifFile, const int GifExtCode, 166 const int GifExtLen, const void *GifExtension); 167 int EGifPutCode(GifFileType *GifFile, int GifCodeSize, 168 const GifByteType *GifCodeBlock); 169 int EGifPutCodeNext(GifFileType *GifFile, const GifByteType *GifCodeBlock); 170 171 /****************************************************************************** 172 GIF decoding routines 173 ******************************************************************************/ 174 175 /* Main entry points */ 176 GifFileType *DGifOpenFileName(const char *GifFileName, int *Error); 177 GifFileType *DGifOpenFileHandle(int GifFileHandle, int *Error); 178 int DGifSlurp(GifFileType *GifFile); 179 GifFileType *DGifOpen(void *userPtr, InputFunc readFunc, 180 int *Error); /* new one (TVT) */ 181 int DGifCloseFile(GifFileType *GifFile, int *ErrorCode); 182 183 #define D_GIF_SUCCEEDED 0 184 #define D_GIF_ERR_OPEN_FAILED 101 /* And DGif possible errors. */ 185 #define D_GIF_ERR_READ_FAILED 102 186 #define D_GIF_ERR_NOT_GIF_FILE 103 187 #define D_GIF_ERR_NO_SCRN_DSCR 104 188 #define D_GIF_ERR_NO_IMAG_DSCR 105 189 #define D_GIF_ERR_NO_COLOR_MAP 106 190 #define D_GIF_ERR_WRONG_RECORD 107 191 #define D_GIF_ERR_DATA_TOO_BIG 108 192 #define D_GIF_ERR_NOT_ENOUGH_MEM 109 193 #define D_GIF_ERR_CLOSE_FAILED 110 194 #define D_GIF_ERR_NOT_READABLE 111 195 #define D_GIF_ERR_IMAGE_DEFECT 112 196 #define D_GIF_ERR_EOF_TOO_SOON 113 197 198 /* These are legacy. You probably do not want to call them directly */ 199 int DGifGetScreenDesc(GifFileType *GifFile); 200 int DGifGetRecordType(GifFileType *GifFile, GifRecordType *GifType); 201 int DGifGetImageHeader(GifFileType *GifFile); 202 int DGifGetImageDesc(GifFileType *GifFile); 203 int DGifGetLine(GifFileType *GifFile, GifPixelType *GifLine, int GifLineLen); 204 int DGifGetPixel(GifFileType *GifFile, GifPixelType GifPixel); 205 int DGifGetExtension(GifFileType *GifFile, int *GifExtCode, 206 GifByteType **GifExtension); 207 int DGifGetExtensionNext(GifFileType *GifFile, GifByteType **GifExtension); 208 int DGifGetCode(GifFileType *GifFile, int *GifCodeSize, 209 GifByteType **GifCodeBlock); 210 int DGifGetCodeNext(GifFileType *GifFile, GifByteType **GifCodeBlock); 211 int DGifGetLZCodes(GifFileType *GifFile, int *GifCode); 212 const char *DGifGetGifVersion(GifFileType *GifFile); 213 214 /****************************************************************************** 215 Error handling and reporting. 216 ******************************************************************************/ 217 extern const char *GifErrorString(int ErrorCode); /* new in 2012 - ESR */ 218 219 /***************************************************************************** 220 Everything below this point is new after version 1.2, supporting `slurp 221 mode' for doing I/O in two big belts with all the image-bashing in core. 222 ******************************************************************************/ 223 224 /****************************************************************************** 225 Color map handling from gif_alloc.c 226 ******************************************************************************/ 227 228 extern ColorMapObject *GifMakeMapObject(int ColorCount, 229 const GifColorType *ColorMap); 230 extern void GifFreeMapObject(ColorMapObject *Object); 231 extern ColorMapObject *GifUnionColorMap(const ColorMapObject *ColorIn1, 232 const ColorMapObject *ColorIn2, 233 GifPixelType ColorTransIn2[]); 234 extern int GifBitSize(int n); 235 236 /****************************************************************************** 237 Support for the in-core structures allocation (slurp mode). 238 ******************************************************************************/ 239 240 extern void GifApplyTranslation(SavedImage *Image, 241 const GifPixelType Translation[]); 242 extern int GifAddExtensionBlock(int *ExtensionBlock_Count, 243 ExtensionBlock **ExtensionBlocks, int Function, 244 unsigned int Len, unsigned char ExtData[]); 245 extern void GifFreeExtensions(int *ExtensionBlock_Count, 246 ExtensionBlock **ExtensionBlocks); 247 extern SavedImage *GifMakeSavedImage(GifFileType *GifFile, 248 const SavedImage *CopyFrom); 249 extern void GifFreeSavedImages(GifFileType *GifFile); 250 251 /****************************************************************************** 252 5.x functions for GIF89 graphics control blocks 253 ******************************************************************************/ 254 255 int DGifExtensionToGCB(const size_t GifExtensionLength, 256 const GifByteType *GifExtension, 257 GraphicsControlBlock *GCB); 258 size_t EGifGCBToExtension(const GraphicsControlBlock *GCB, 259 GifByteType *GifExtension); 260 261 int DGifSavedExtensionToGCB(GifFileType *GifFile, int ImageIndex, 262 GraphicsControlBlock *GCB); 263 int EGifGCBToSavedExtension(const GraphicsControlBlock *GCB, 264 GifFileType *GifFile, int ImageIndex); 265 266 /****************************************************************************** 267 The library's internal utility font 268 ******************************************************************************/ 269 270 #define GIF_FONT_WIDTH 8 271 #define GIF_FONT_HEIGHT 8 272 extern const unsigned char GifAsciiTable8x8[][GIF_FONT_WIDTH]; 273 274 extern void GifDrawText8x8(SavedImage *Image, const int x, const int y, 275 const char *legend, const int color); 276 277 extern void GifDrawBox(SavedImage *Image, const int x, const int y, const int w, 278 const int d, const int color); 279 280 extern void GifDrawRectangle(SavedImage *Image, const int x, const int y, 281 const int w, const int d, const int color); 282 283 extern void GifDrawBoxedText8x8(SavedImage *Image, const int x, const int y, 284 const char *legend, const int border, 285 const int bg, const int fg); 286 287 #ifdef __cplusplus 288 } 289 #endif /* __cplusplus */ 290 #endif /* _GIF_LIB_H */ 291 292 /* end */ 293