Mercurial > hg > xemacs-beta

comparison src/gifrlib.h @ 308:33bdb3d4b97f r21-0b52

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Import from CVS: tag r21-0b52
author cvs
date Mon, 13 Aug 2007 10:42:44 +0200
parents
children 19dcec799385
comparison
equal deleted inserted replaced
307:42d630fd9bd8 308:33bdb3d4b97f
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
17 #ifndef GIF_LIB_H
18 #define GIF_LIB_H
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 #ifdef SYSV
40 #define VoidPtr char *
41 #else
42 #define VoidPtr void *
43 #endif /* SYSV */
44
45 typedef struct GifColorType {
46 GifByteType Red, Green, Blue;
47 } GifColorType;
48
49 typedef struct ColorMapObject
50 {
51 int ColorCount;
52 int BitsPerPixel;
53 GifColorType *Colors; /* on malloc(3) heap */
54 }
55 ColorMapObject;
56
57 typedef struct GifImageDesc {
58 int Left, Top, Width, Height, /* Current image dimensions. */
59 Interlace; /* Sequential/Interlaced lines. */
60 ColorMapObject *ColorMap; /* The local color map */
61 } GifImageDesc;
62
63 /* I/O operations. If you roll your own, they need to be semantically equivilent to
64 fread/fwrite, with an additional paramater to hold data local to your method. */
65 typedef size_t (*Gif_rw_func)(GifByteType *buffer, size_t size, VoidPtr method_data);
66 /* Finish up stream. Non-zero return indicates failure */
67 typedef int (*Gif_close_func)(VoidPtr close_data);
68 /* Error handling function */
69 typedef void (*Gif_error_func)(const char *string, VoidPtr error_data);
70
71 typedef struct GifFileType {
72 int SWidth, SHeight, /* Screen dimensions. */
73 SColorResolution, /* How many colors can we generate? */
74 SBackGroundColor; /* I hope you understand this one... */
75 ColorMapObject *SColorMap; /* NULL if it doesn't exist. */
76 int ImageCount; /* Number of current image */
77 GifImageDesc Image; /* Block describing current image */
78 struct SavedImage *SavedImages; /* Use this to accumulate file state */
79 VoidPtr Private; /* Don't mess with this! */
80 VoidPtr GifIO; /* Contains all information for I/O */
81 } GifFileType;
82
83 typedef enum {
84 UNDEFINED_RECORD_TYPE,
85 SCREEN_DESC_RECORD_TYPE,
86 IMAGE_DESC_RECORD_TYPE, /* Begin with ',' */
87 EXTENSION_RECORD_TYPE, /* Begin with '!' */
88 TERMINATE_RECORD_TYPE /* Begin with ';' */
89 } GifRecordType;
90
91 /******************************************************************************
92 * GIF89 extension function codes *
93 ******************************************************************************/
94
95 #define COMMENT_EXT_FUNC_CODE 0xfe /* comment */
96 #define GRAPHICS_EXT_FUNC_CODE 0xf9 /* graphics control */
97 #define PLAINTEXT_EXT_FUNC_CODE 0x01 /* plaintext */
98 #define APPLICATION_EXT_FUNC_CODE 0xff /* application block */
99
100 /******************************************************************************
101 * IO related routines. Defined in gif_io.c *
102 ******************************************************************************/
103 GifFileType *GifSetup(void);
104 void GifFree(GifFileType *GifFile);
105 void GifSetReadFunc (GifFileType *GifFile, Gif_rw_func func, VoidPtr data);
106 void GifSetWriteFunc(GifFileType *GifFile, Gif_rw_func func, VoidPtr data);
107 void GifSetCloseFunc(GifFileType *GifFile, Gif_close_func func, VoidPtr data);
108
109 /******************************************************************************
110 * O.K., here are the routines one can access in order to decode GIF file: *
111 ******************************************************************************/
112
113 void DGifOpenFileName(GifFileType *GifFile, const char *GifFileName);
114 void DGifOpenFileHandle(GifFileType *GifFile, int GifFileHandle);
115 void DGifInitRead(GifFileType *GifFile);
116 void DGifSlurp(GifFileType *GifFile);
117 void DGifGetScreenDesc(GifFileType *GifFile);
118 void DGifGetRecordType(GifFileType *GifFile, GifRecordType *GifType);
119 void DGifGetImageDesc(GifFileType *GifFile);
120 void DGifGetLine(GifFileType *GifFile, GifPixelType *GifLine, int GifLineLen);
121 void DGifGetPixel(GifFileType *GifFile, GifPixelType GifPixel);
122 void DGifGetComment(GifFileType *GifFile, char *GifComment);
123 void DGifGetExtension(GifFileType *GifFile, int *GifExtCode,
124 GifByteType **GifExtension);
125 void DGifGetExtensionNext(GifFileType *GifFile, GifByteType **GifExtension);
126 void DGifGetCode(GifFileType *GifFile, int *GifCodeSize,
127 GifByteType **GifCodeBlock);
128 void DGifGetCodeNext(GifFileType *GifFile, GifByteType **GifCodeBlock);
129 void DGifGetLZCodes(GifFileType *GifFile, int *GifCode);
130 int DGifCloseFile(GifFileType *GifFile);
131
132 #define D_GIF_ERR_OPEN_FAILED 101 /* And DGif possible errors. */
133 #define D_GIF_ERR_READ_FAILED 102
134 #define D_GIF_ERR_NOT_GIF_FILE 103
135 #define D_GIF_ERR_NO_SCRN_DSCR 104
136 #define D_GIF_ERR_NO_IMAG_DSCR 105
137 #define D_GIF_ERR_NO_COLOR_MAP 106
138 #define D_GIF_ERR_WRONG_RECORD 107
139 #define D_GIF_ERR_DATA_TOO_BIG 108
140 #define GIF_ERR_NOT_ENOUGH_MEM 109
141 #define D_GIF_ERR_NOT_ENOUGH_MEM 109
142 #define D_GIF_ERR_CLOSE_FAILED 110
143 #define D_GIF_ERR_NOT_READABLE 111
144 #define D_GIF_ERR_IMAGE_DEFECT 112
145 #define D_GIF_ERR_EOF_TOO_SOON 113
146
147 /******************************************************************************
148 * O.K., here are the error routines *
149 ******************************************************************************/
150 extern void GifSetErrorFunc(GifFileType *GifFile, Gif_error_func func, VoidPtr data);
151 extern void GifSetWarningFunc(GifFileType *GifFile, Gif_error_func func, VoidPtr data);
152 extern void GifInternError(GifFileType *GifFile, int errnum);
153 extern void GifInternWarning(GifFileType *GifFile, int errnum);
154 extern void GifError(GifFileType *GifFile, const char *err_str);
155 extern void GifWarning(GifFileType *GifFile, const char *err_str);
156
157 /*****************************************************************************
158 *
159 * Everything below this point is new after version 1.2, supporting `slurp
160 * mode' for doing I/O in two big belts with all the image-bashing in core.
161 *
162 *****************************************************************************/
163
164 /******************************************************************************
165 * Support for the in-core structures allocation (slurp mode). *
166 ******************************************************************************/
167
168 /* This is the in-core version of an extension record */
169 typedef struct {
170 int ByteCount;
171 char *Bytes; /* on malloc(3) heap */
172 } ExtensionBlock;
173
174 /* This holds an image header, its unpacked raster bits, and extensions */
175 typedef struct SavedImage {
176 GifImageDesc ImageDesc;
177
178 char *RasterBits; /* on malloc(3) heap */
179
180 int Function;
181 int ExtensionBlockCount;
182 ExtensionBlock *ExtensionBlocks; /* on malloc(3) heap */
183 } SavedImage;
184
185 extern void ApplyTranslation(SavedImage *Image, GifPixelType Translation[]);
186
187 extern void MakeExtension(SavedImage *New, int Function);
188 extern int AddExtensionBlock(SavedImage *New, int Length, GifByteType *data);
189 extern void FreeExtension(SavedImage *Image);
190
191 extern SavedImage *MakeSavedImage(GifFileType *GifFile, SavedImage *CopyFrom);
192 extern void FreeSavedImages(GifFileType *GifFile);
193
194 /* Common defines used by encode/decode functions */
195
196 #define COMMENT_EXT_FUNC_CODE 0xfe /* Extension function code for comment. */
197 #define GIF_STAMP "GIFVER" /* First chars in file - GIF stamp. */
198 #define GIF_STAMP_LEN sizeof(GIF_STAMP) - 1
199 #define GIF_VERSION_POS 3 /* Version first character in stamp. */
200 #define GIF87_STAMP "GIF87a" /* First chars in file - GIF stamp. */
201 #define GIF89_STAMP "GIF89a" /* First chars in file - GIF stamp. */
202
203 #define LZ_MAX_CODE 4095 /* Biggest code possible in 12 bits. */
204 #define LZ_BITS 12
205
206 #define FILE_STATE_READ 0x01
207 #define FILE_STATE_WRITE 0x01
208 #define FILE_STATE_SCREEN 0x02
209 #define FILE_STATE_IMAGE 0x04
210
211 #define FLUSH_OUTPUT 4096 /* Impossible code, to signal flush. */
212 #define FIRST_CODE 4097 /* Impossible code, to signal first. */
213 #define NO_SUCH_CODE 4098 /* Impossible code, to signal empty. */
214
215 #define IS_READABLE(Private) (!(Private->FileState & FILE_STATE_READ))
216 #define IS_WRITEABLE(Private) (Private->FileState & FILE_STATE_WRITE)
217
218 typedef struct GifFilePrivateType {
219 int FileState,
220 BitsPerPixel, /* Bits per pixel (Codes uses at list this + 1). */
221 ClearCode, /* The CLEAR LZ code. */
222 EOFCode, /* The EOF LZ code. */
223 RunningCode, /* The next code algorithm can generate. */
224 RunningBits,/* The number of bits required to represent RunningCode. */
225 MaxCode1, /* 1 bigger than max. possible code, in RunningBits bits. */
226 LastCode, /* The code before the current code. */
227 CrntCode, /* Current algorithm code. */
228 StackPtr, /* For character stack (see below). */
229 CrntShiftState; /* Number of bits in CrntShiftDWord. */
230 unsigned long CrntShiftDWord; /* For bytes decomposition into codes. */
231 unsigned long PixelCount; /* Number of pixels in image. */
232 GifByteType Buf[256]; /* Compressed input is buffered here. */
233 GifByteType Stack[LZ_MAX_CODE]; /* Decoded pixels are stacked here. */
234 GifByteType Suffix[LZ_MAX_CODE+1]; /* So we can trace the codes. */
235 unsigned int Prefix[LZ_MAX_CODE+1];
236 } GifFilePrivateType;
237
238 typedef struct GifIODataType {
239 Gif_rw_func ReadFunc, WriteFunc; /* Pointers to the functions that will do the I/O */
240 Gif_close_func CloseFunc;
241 VoidPtr ReadFunc_data; /* data to be passed to the read function */
242 VoidPtr WriteFunc_data; /* data to be passed to the write function */
243 VoidPtr CloseFunc_data; /* data to be passed to the close function */
244 Gif_error_func ErrorFunc; /* MUST NOT RETURN (use lng_jmp or exit)! */
245 Gif_error_func WarningFunc; /* For warning messages (can be ignored) */
246 VoidPtr ErrorFunc_data;
247 VoidPtr WarningFunc_data;
248 } GifIODataType;
249
250 typedef struct GifStdIODataType {
251 FILE *File;
252 int FileHandle;
253 } GifStdIODataType;
254
255 /* Install StdIO funcs on FILE into GifFile */
256 void GifStdIOInit(GifFileType *GifFile, FILE *file, int filehandle);
257
258 /* Error checking reads, writes and closes */
259 void GifRead(GifByteType *buf, size_t size, GifFileType *GifFile);
260 void GifWrite(GifByteType *buf, size_t size, GifFileType *GifFile);
261 int GifClose(GifFileType *GifFile);
262
263 /* The default Read and Write functions for files */
264 size_t GifStdRead(GifByteType *buf, size_t size, VoidPtr method_data);
265 size_t GifStdWrite(GifByteType *buf, size_t size, VoidPtr method_data);
266 int GifStdFileClose(VoidPtr method_data);
267
268 ColorMapObject *MakeMapObject(int ColorCount, GifColorType *ColorMap);
269 void FreeMapObject(ColorMapObject *Object);
270
271
272 #endif /* GIF_LIB_H */