1/****************************************************************************** 2 3gif_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 11extern "C" { 12#endif /* __cplusplus */ 13 14#define GIFLIB_MAJOR 5 15#define GIFLIB_MINOR 0 16#define GIFLIB_RELEASE 4 17 18#define GIF_ERROR 0 19#define GIF_OK 1 20 21#include <stdbool.h> 22 23#define GIF_STAMP "GIFVER" /* First chars in file - GIF stamp. */ 24#define GIF_STAMP_LEN sizeof(GIF_STAMP) - 1 25#define GIF_VERSION_POS 3 /* Version first character in stamp. */ 26#define GIF87_STAMP "GIF87a" /* First chars in file - GIF stamp. */ 27#define GIF89_STAMP "GIF89a" /* First chars in file - GIF stamp. */ 28 29typedef unsigned char GifPixelType; 30typedef unsigned char *GifRowType; 31typedef unsigned char GifByteType; 32typedef unsigned int GifPrefixType; 33typedef int GifWord; 34 35typedef struct GifColorType { 36 GifByteType Red, Green, Blue; 37} GifColorType; 38 39typedef struct ColorMapObject { 40 int ColorCount; 41 int BitsPerPixel; 42 bool SortFlag; 43 GifColorType *Colors; /* on malloc(3) heap */ 44} ColorMapObject; 45 46typedef struct GifImageDesc { 47 GifWord Left, Top, Width, Height; /* Current image dimensions. */ 48 bool Interlace; /* Sequential/Interlaced lines. */ 49 ColorMapObject *ColorMap; /* The local color map */ 50} GifImageDesc; 51 52typedef struct ExtensionBlock { 53 int ByteCount; 54 GifByteType *Bytes; /* on malloc(3) heap */ 55 int Function; /* The block function code */ 56#define CONTINUE_EXT_FUNC_CODE 0x00 /* continuation subblock */ 57#define COMMENT_EXT_FUNC_CODE 0xfe /* comment */ 58#define GRAPHICS_EXT_FUNC_CODE 0xf9 /* graphics control (GIF89) */ 59#define PLAINTEXT_EXT_FUNC_CODE 0x01 /* plaintext */ 60#define APPLICATION_EXT_FUNC_CODE 0xff /* application block */ 61} ExtensionBlock; 62 63typedef struct SavedImage { 64 GifImageDesc ImageDesc; 65 GifByteType *RasterBits; /* on malloc(3) heap */ 66 int ExtensionBlockCount; /* Count of extensions before image */ 67 ExtensionBlock *ExtensionBlocks; /* Extensions before image */ 68} SavedImage; 69 70typedef struct GifFileType { 71 GifWord SWidth, SHeight; /* Size of virtual canvas */ 72 GifWord SColorResolution; /* How many colors can we generate? */ 73 GifWord SBackGroundColor; /* Background color for virtual canvas */ 74 GifByteType AspectByte; /* Used to compute pixel aspect ratio */ 75 ColorMapObject *SColorMap; /* Global colormap, NULL if nonexistent. */ 76 int ImageCount; /* Number of current image (both APIs) */ 77 GifImageDesc Image; /* Current image (low-level API) */ 78 SavedImage *SavedImages; /* Image sequence (high-level API) */ 79 int ExtensionBlockCount; /* Count extensions past last image */ 80 ExtensionBlock *ExtensionBlocks; /* Extensions past last image */ 81 int Error; /* Last error condition reported */ 82 void *UserData; /* hook to attach user data (TVT) */ 83 void *Private; /* Don't mess with this! */ 84} GifFileType; 85 86#define GIF_ASPECT_RATIO(n) ((n)+15.0/64.0) 87 88typedef enum { 89 UNDEFINED_RECORD_TYPE, 90 SCREEN_DESC_RECORD_TYPE, 91 IMAGE_DESC_RECORD_TYPE, /* Begin with ',' */ 92 EXTENSION_RECORD_TYPE, /* Begin with '!' */ 93 TERMINATE_RECORD_TYPE /* Begin with ';' */ 94} GifRecordType; 95 96/* func type to read gif data from arbitrary sources (TVT) */ 97typedef int (*InputFunc) (GifFileType *, GifByteType *, int); 98 99/* func type to write gif data to arbitrary targets. 100 * Returns count of bytes written. (MRB) 101 */ 102typedef int (*OutputFunc) (GifFileType *, const GifByteType *, int); 103 104/****************************************************************************** 105 GIF89 structures 106******************************************************************************/ 107 108typedef struct GraphicsControlBlock { 109 int DisposalMode; 110#define DISPOSAL_UNSPECIFIED 0 /* No disposal specified. */ 111#define DISPOSE_DO_NOT 1 /* Leave image in place */ 112#define DISPOSE_BACKGROUND 2 /* Set area too background color */ 113#define DISPOSE_PREVIOUS 3 /* Restore to previous content */ 114 bool UserInputFlag; /* User confirmation required before disposal */ 115 int DelayTime; /* pre-display delay in 0.01sec units */ 116 int TransparentColor; /* Palette index for transparency, -1 if none */ 117#define NO_TRANSPARENT_COLOR -1 118} GraphicsControlBlock; 119 120/****************************************************************************** 121 GIF encoding routines 122******************************************************************************/ 123 124/* Main entry points */ 125GifFileType *EGifOpenFileName(const char *GifFileName, 126 const bool GifTestExistence, int *Error); 127GifFileType *EGifOpenFileHandle(const int GifFileHandle, int *Error); 128GifFileType *EGifOpen(void *userPtr, OutputFunc writeFunc, int *Error); 129int EGifSpew(GifFileType * GifFile); 130char *EGifGetGifVersion(GifFileType *GifFile); /* new in 5.x */ 131int EGifCloseFile(GifFileType * GifFile); 132 133#define E_GIF_ERR_OPEN_FAILED 1 /* And EGif possible errors. */ 134#define E_GIF_ERR_WRITE_FAILED 2 135#define E_GIF_ERR_HAS_SCRN_DSCR 3 136#define E_GIF_ERR_HAS_IMAG_DSCR 4 137#define E_GIF_ERR_NO_COLOR_MAP 5 138#define E_GIF_ERR_DATA_TOO_BIG 6 139#define E_GIF_ERR_NOT_ENOUGH_MEM 7 140#define E_GIF_ERR_DISK_IS_FULL 8 141#define E_GIF_ERR_CLOSE_FAILED 9 142#define E_GIF_ERR_NOT_WRITEABLE 10 143 144/* These are legacy. You probably do not want to call them directly */ 145int EGifPutScreenDesc(GifFileType *GifFile, 146 const int GifWidth, const int GifHeight, 147 const int GifColorRes, 148 const int GifBackGround, 149 const ColorMapObject *GifColorMap); 150int EGifPutImageDesc(GifFileType *GifFile, 151 const int GifLeft, const int GifTop, 152 const int GifWidth, const int GifHeight, 153 const bool GifInterlace, 154 const ColorMapObject *GifColorMap); 155void EGifSetGifVersion(GifFileType *GifFile, const bool gif89); 156int EGifPutLine(GifFileType *GifFile, GifPixelType *GifLine, 157 int GifLineLen); 158int EGifPutPixel(GifFileType *GifFile, const GifPixelType GifPixel); 159int EGifPutComment(GifFileType *GifFile, const char *GifComment); 160int EGifPutExtensionLeader(GifFileType *GifFile, const int GifExtCode); 161int EGifPutExtensionBlock(GifFileType *GifFile, 162 const int GifExtLen, const void *GifExtension); 163int EGifPutExtensionTrailer(GifFileType *GifFile); 164int EGifPutExtension(GifFileType *GifFile, const int GifExtCode, 165 const int GifExtLen, 166 const void *GifExtension); 167int EGifPutCode(GifFileType *GifFile, int GifCodeSize, 168 const GifByteType *GifCodeBlock); 169int EGifPutCodeNext(GifFileType *GifFile, 170 const GifByteType *GifCodeBlock); 171 172/****************************************************************************** 173 GIF decoding routines 174******************************************************************************/ 175 176/* Main entry points */ 177GifFileType *DGifOpenFileName(const char *GifFileName, int *Error); 178GifFileType *DGifOpenFileHandle(int GifFileHandle, int *Error); 179int DGifSlurp(GifFileType * GifFile); 180GifFileType *DGifOpen(void *userPtr, InputFunc readFunc, int *Error); /* new one (TVT) */ 181int DGifCloseFile(GifFileType * GifFile); 182 183#define D_GIF_ERR_OPEN_FAILED 101 /* And DGif possible errors. */ 184#define D_GIF_ERR_READ_FAILED 102 185#define D_GIF_ERR_NOT_GIF_FILE 103 186#define D_GIF_ERR_NO_SCRN_DSCR 104 187#define D_GIF_ERR_NO_IMAG_DSCR 105 188#define D_GIF_ERR_NO_COLOR_MAP 106 189#define D_GIF_ERR_WRONG_RECORD 107 190#define D_GIF_ERR_DATA_TOO_BIG 108 191#define D_GIF_ERR_NOT_ENOUGH_MEM 109 192#define D_GIF_ERR_CLOSE_FAILED 110 193#define D_GIF_ERR_NOT_READABLE 111 194#define D_GIF_ERR_IMAGE_DEFECT 112 195#define D_GIF_ERR_EOF_TOO_SOON 113 196 197/* These are legacy. You probably do not want to call them directly */ 198int DGifGetScreenDesc(GifFileType *GifFile); 199int DGifGetRecordType(GifFileType *GifFile, GifRecordType *GifType); 200int DGifGetImageDesc(GifFileType *GifFile); 201int DGifGetLine(GifFileType *GifFile, GifPixelType *GifLine, int GifLineLen); 202int DGifGetPixel(GifFileType *GifFile, GifPixelType GifPixel); 203int DGifGetComment(GifFileType *GifFile, char *GifComment); 204int DGifGetExtension(GifFileType *GifFile, int *GifExtCode, 205 GifByteType **GifExtension); 206int DGifGetExtensionNext(GifFileType *GifFile, GifByteType **GifExtension); 207int DGifGetCode(GifFileType *GifFile, int *GifCodeSize, 208 GifByteType **GifCodeBlock); 209int DGifGetCodeNext(GifFileType *GifFile, GifByteType **GifCodeBlock); 210int DGifGetLZCodes(GifFileType *GifFile, int *GifCode); 211 212 213/****************************************************************************** 214 Color table quantization (deprecated) 215******************************************************************************/ 216int GifQuantizeBuffer(unsigned int Width, unsigned int Height, 217 int *ColorMapSize, GifByteType * RedInput, 218 GifByteType * GreenInput, GifByteType * BlueInput, 219 GifByteType * OutputBuffer, 220 GifColorType * OutputColorMap); 221 222/****************************************************************************** 223 Error handling and reporting. 224******************************************************************************/ 225extern char *GifErrorString(int ErrorCode); /* new in 2012 - ESR */ 226 227/***************************************************************************** 228 Everything below this point is new after version 1.2, supporting `slurp 229 mode' for doing I/O in two big belts with all the image-bashing in core. 230******************************************************************************/ 231 232/****************************************************************************** 233 Color map handling from gif_alloc.c 234******************************************************************************/ 235 236extern ColorMapObject *GifMakeMapObject(int ColorCount, 237 const GifColorType *ColorMap); 238extern void GifFreeMapObject(ColorMapObject *Object); 239extern ColorMapObject *GifUnionColorMap(const ColorMapObject *ColorIn1, 240 const ColorMapObject *ColorIn2, 241 GifPixelType ColorTransIn2[]); 242extern int GifBitSize(int n); 243 244/****************************************************************************** 245 Support for the in-core structures allocation (slurp mode). 246******************************************************************************/ 247 248extern void GifApplyTranslation(SavedImage *Image, GifPixelType Translation[]); 249extern int GifAddExtensionBlock(int *ExtensionBlock_Count, 250 ExtensionBlock **ExtensionBlocks, 251 int Function, 252 unsigned int Len, unsigned char ExtData[]); 253extern void GifFreeExtensions(int *ExtensionBlock_Count, 254 ExtensionBlock **ExtensionBlocks); 255extern SavedImage *GifMakeSavedImage(GifFileType *GifFile, 256 const SavedImage *CopyFrom); 257extern void GifFreeSavedImages(GifFileType *GifFile); 258 259/****************************************************************************** 260 5.x functions for GIF89 graphics control blocks 261******************************************************************************/ 262 263int DGifExtensionToGCB(const size_t GifExtensionLength, 264 const GifByteType *GifExtension, 265 GraphicsControlBlock *GCB); 266size_t EGifGCBToExtension(const GraphicsControlBlock *GCB, 267 GifByteType *GifExtension); 268 269int DGifSavedExtensionToGCB(GifFileType *GifFile, 270 int ImageIndex, 271 GraphicsControlBlock *GCB); 272int EGifGCBToSavedExtension(const GraphicsControlBlock *GCB, 273 GifFileType *GifFile, 274 int ImageIndex); 275 276#ifdef __cplusplus 277} 278#endif /* __cplusplus */ 279#endif /* _GIF_LIB_H */ 280 281/* end */ 282