1/******************************************************************************
2
3gif_lib.h - service library for decoding and encoding GIF images
4
5SPDX-License-Identifier: MIT
6
7*****************************************************************************/
8
9#ifndef _GIF_LIB_H_
10#define _GIF_LIB_H_ 1
11
12#ifdef __cplusplus
13extern "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 <stddef.h>
24#include <stdbool.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
32typedef unsigned char GifPixelType;
33typedef unsigned char *GifRowType;
34typedef unsigned char GifByteType;
35typedef unsigned int GifPrefixType;
36typedef int GifWord;
37
38typedef struct GifColorType {
39 GifByteType Red, Green, Blue;
40} GifColorType;
41
42typedef struct ColorMapObject {
43 int ColorCount;
44 int BitsPerPixel;
45 bool SortFlag;
46 GifColorType *Colors; /* on malloc(3) heap */
47} ColorMapObject;
48
49typedef 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
55typedef 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
66typedef 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
73typedef 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
91typedef 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) */
100typedef int (*InputFunc) (GifFileType *, GifByteType *, int);
101
102/* func type to write gif data to arbitrary targets.
103 * Returns count of bytes written. (MRB)
104 */
105typedef int (*OutputFunc) (GifFileType *, const GifByteType *, int);
106
107/******************************************************************************
108 GIF89 structures
109******************************************************************************/
110
111typedef 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 */
128GifFileType *EGifOpenFileName(const char *GifFileName,
129 const bool GifTestExistence, int *Error);
130GifFileType *EGifOpenFileHandle(const int GifFileHandle, int *Error);
131GifFileType *EGifOpen(void *userPtr, OutputFunc writeFunc, int *Error);
132int EGifSpew(GifFileType * GifFile);
133const char *EGifGetGifVersion(GifFileType *GifFile); /* new in 5.x */
134int 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 */
149int EGifPutScreenDesc(GifFileType *GifFile,
150 const int GifWidth, const int GifHeight,
151 const int GifColorRes,
152 const int GifBackGround,
153 const ColorMapObject *GifColorMap);
154int EGifPutImageDesc(GifFileType *GifFile,
155 const int GifLeft, const int GifTop,
156 const int GifWidth, const int GifHeight,
157 const bool GifInterlace,
158 const ColorMapObject *GifColorMap);
159void EGifSetGifVersion(GifFileType *GifFile, const bool gif89);
160int EGifPutLine(GifFileType *GifFile, GifPixelType *GifLine,
161 int GifLineLen);
162int EGifPutPixel(GifFileType *GifFile, const GifPixelType GifPixel);
163int EGifPutComment(GifFileType *GifFile, const char *GifComment);
164int EGifPutExtensionLeader(GifFileType *GifFile, const int GifExtCode);
165int EGifPutExtensionBlock(GifFileType *GifFile,
166 const int GifExtLen, const void *GifExtension);
167int EGifPutExtensionTrailer(GifFileType *GifFile);
168int EGifPutExtension(GifFileType *GifFile, const int GifExtCode,
169 const int GifExtLen,
170 const void *GifExtension);
171int EGifPutCode(GifFileType *GifFile, int GifCodeSize,
172 const GifByteType *GifCodeBlock);
173int EGifPutCodeNext(GifFileType *GifFile,
174 const GifByteType *GifCodeBlock);
175
176/******************************************************************************
177 GIF decoding routines
178******************************************************************************/
179
180/* Main entry points */
181GifFileType *DGifOpenFileName(const char *GifFileName, int *Error);
182GifFileType *DGifOpenFileHandle(int GifFileHandle, int *Error);
183int DGifSlurp(GifFileType * GifFile);
184GifFileType *DGifOpen(void *userPtr, InputFunc readFunc, int *Error); /* new one (TVT) */
185 int DGifCloseFile(GifFileType * GifFile, int *ErrorCode);
186
187#define D_GIF_SUCCEEDED 0
188#define D_GIF_ERR_OPEN_FAILED 101 /* And DGif possible errors. */
189#define D_GIF_ERR_READ_FAILED 102
190#define D_GIF_ERR_NOT_GIF_FILE 103
191#define D_GIF_ERR_NO_SCRN_DSCR 104
192#define D_GIF_ERR_NO_IMAG_DSCR 105
193#define D_GIF_ERR_NO_COLOR_MAP 106
194#define D_GIF_ERR_WRONG_RECORD 107
195#define D_GIF_ERR_DATA_TOO_BIG 108
196#define D_GIF_ERR_NOT_ENOUGH_MEM 109
197#define D_GIF_ERR_CLOSE_FAILED 110
198#define D_GIF_ERR_NOT_READABLE 111
199#define D_GIF_ERR_IMAGE_DEFECT 112
200#define D_GIF_ERR_EOF_TOO_SOON 113
201
202/* These are legacy. You probably do not want to call them directly */
203int DGifGetScreenDesc(GifFileType *GifFile);
204int DGifGetRecordType(GifFileType *GifFile, GifRecordType *GifType);
205int DGifGetImageHeader(GifFileType *GifFile);
206int DGifGetImageDesc(GifFileType *GifFile);
207int DGifGetLine(GifFileType *GifFile, GifPixelType *GifLine, int GifLineLen);
208int DGifGetPixel(GifFileType *GifFile, GifPixelType GifPixel);
209int DGifGetExtension(GifFileType *GifFile, int *GifExtCode,
210 GifByteType **GifExtension);
211int DGifGetExtensionNext(GifFileType *GifFile, GifByteType **GifExtension);
212int DGifGetCode(GifFileType *GifFile, int *GifCodeSize,
213 GifByteType **GifCodeBlock);
214int DGifGetCodeNext(GifFileType *GifFile, GifByteType **GifCodeBlock);
215int DGifGetLZCodes(GifFileType *GifFile, int *GifCode);
216const char *DGifGetGifVersion(GifFileType *GifFile);
217
218
219/******************************************************************************
220 Error handling and reporting.
221******************************************************************************/
222extern const char *GifErrorString(int ErrorCode); /* new in 2012 - ESR */
223
224/*****************************************************************************
225 Everything below this point is new after version 1.2, supporting `slurp
226 mode' for doing I/O in two big belts with all the image-bashing in core.
227******************************************************************************/
228
229/******************************************************************************
230 Color map handling from gif_alloc.c
231******************************************************************************/
232
233extern ColorMapObject *GifMakeMapObject(int ColorCount,
234 const GifColorType *ColorMap);
235extern void GifFreeMapObject(ColorMapObject *Object);
236extern ColorMapObject *GifUnionColorMap(const ColorMapObject *ColorIn1,
237 const ColorMapObject *ColorIn2,
238 GifPixelType ColorTransIn2[]);
239extern int GifBitSize(int n);
240
241/******************************************************************************
242 Support for the in-core structures allocation (slurp mode).
243******************************************************************************/
244
245extern void GifApplyTranslation(SavedImage *Image, GifPixelType Translation[]);
246extern int GifAddExtensionBlock(int *ExtensionBlock_Count,
247 ExtensionBlock **ExtensionBlocks,
248 int Function,
249 unsigned int Len, unsigned char ExtData[]);
250extern void GifFreeExtensions(int *ExtensionBlock_Count,
251 ExtensionBlock **ExtensionBlocks);
252extern SavedImage *GifMakeSavedImage(GifFileType *GifFile,
253 const SavedImage *CopyFrom);
254extern void GifFreeSavedImages(GifFileType *GifFile);
255
256/******************************************************************************
257 5.x functions for GIF89 graphics control blocks
258******************************************************************************/
259
260int DGifExtensionToGCB(const size_t GifExtensionLength,
261 const GifByteType *GifExtension,
262 GraphicsControlBlock *GCB);
263size_t EGifGCBToExtension(const GraphicsControlBlock *GCB,
264 GifByteType *GifExtension);
265
266int DGifSavedExtensionToGCB(GifFileType *GifFile,
267 int ImageIndex,
268 GraphicsControlBlock *GCB);
269int EGifGCBToSavedExtension(const GraphicsControlBlock *GCB,
270 GifFileType *GifFile,
271 int ImageIndex);
272
273/******************************************************************************
274 The library's internal utility font
275******************************************************************************/
276
277#define GIF_FONT_WIDTH 8
278#define GIF_FONT_HEIGHT 8
279extern const unsigned char GifAsciiTable8x8[][GIF_FONT_WIDTH];
280
281extern void GifDrawText8x8(SavedImage *Image,
282 const int x, const int y,
283 const char *legend, const int color);
284
285extern void GifDrawBox(SavedImage *Image,
286 const int x, const int y,
287 const int w, const int d, const int color);
288
289extern void GifDrawRectangle(SavedImage *Image,
290 const int x, const int y,
291 const int w, const int d, const int color);
292
293extern void GifDrawBoxedText8x8(SavedImage *Image,
294 const int x, const int y,
295 const char *legend,
296 const int border, const int bg, const int fg);
297
298#ifdef __cplusplus
299}
300#endif /* __cplusplus */
301#endif /* _GIF_LIB_H */
302
303/* end */
304