1 |
/* $Header$ */
|
2 |
|
3 |
/*
|
4 |
* tkImgGIF.c --
|
5 |
*
|
6 |
* A photo image file handler for GIF files. Reads 87a and 89a GIF
|
7 |
* files. At present, there only is a file write function. GIF images may be
|
8 |
* read using the -data option of the photo image. The data may be
|
9 |
* given as a binary string in a Tcl_Obj or by representing
|
10 |
* the data as BASE64 encoded ascii. Derived from the giftoppm code
|
11 |
* found in the pbmplus package and tkImgFmtPPM.c in the tk4.0b2
|
12 |
* distribution.
|
13 |
*
|
14 |
* Copyright (c) Reed Wade (wade@cs.utk.edu), University of Tennessee
|
15 |
* Copyright (c) 1995-1997 Sun Microsystems, Inc.
|
16 |
* Copyright (c) 1997 Australian National University
|
17 |
*
|
18 |
* See the file "license.terms" for information on usage and redistribution
|
19 |
* of this file, and for a DISCLAIMER OF ALL WARRANTIES.
|
20 |
*
|
21 |
* This file also contains code from the giftoppm program, which is
|
22 |
* copyrighted as follows:
|
23 |
*
|
24 |
* +-------------------------------------------------------------------+
|
25 |
* | Copyright 1990, David Koblas. |
|
26 |
* | Permission to use, copy, modify, and distribute this software |
|
27 |
* | and its documentation for any purpose and without fee is hereby |
|
28 |
* | granted, provided that the above copyright notice appear in all |
|
29 |
* | copies and that both that copyright notice and this permission |
|
30 |
* | notice appear in supporting documentation. This software is |
|
31 |
* | provided "as is" without express or implied warranty. |
|
32 |
* +-------------------------------------------------------------------+
|
33 |
*
|
34 |
* RCS: @(#) $Id: tkimggif.c,v 1.1.1.1 2001/06/13 05:02:40 dtashley Exp $
|
35 |
*/
|
36 |
|
37 |
/*
|
38 |
* GIF's are represented as data in base64 format.
|
39 |
* base64 strings consist of 4 6-bit characters -> 3 8 bit bytes.
|
40 |
* A-Z, a-z, 0-9, + and / represent the 64 values (in order).
|
41 |
* '=' is a trailing padding char when the un-encoded data is not a
|
42 |
* multiple of 3 bytes. We'll ignore white space when encountered.
|
43 |
* Any other invalid character is treated as an EOF
|
44 |
*/
|
45 |
|
46 |
#define GIF_SPECIAL (256)
|
47 |
#define GIF_PAD (GIF_SPECIAL+1)
|
48 |
#define GIF_SPACE (GIF_SPECIAL+2)
|
49 |
#define GIF_BAD (GIF_SPECIAL+3)
|
50 |
#define GIF_DONE (GIF_SPECIAL+4)
|
51 |
|
52 |
/*
|
53 |
* structure to "mimic" FILE for Mread, so we can look like fread.
|
54 |
* The decoder state keeps track of which byte we are about to read,
|
55 |
* or EOF.
|
56 |
*/
|
57 |
|
58 |
typedef struct mFile {
|
59 |
unsigned char *data; /* mmencoded source string */
|
60 |
int c; /* bits left over from previous character */
|
61 |
int state; /* decoder state (0-4 or GIF_DONE) */
|
62 |
} MFile;
|
63 |
|
64 |
#include "tkInt.h"
|
65 |
#include "tkPort.h"
|
66 |
|
67 |
/*
|
68 |
* Non-ASCII encoding support:
|
69 |
* Most data in a GIF image is binary and is treated as such. However,
|
70 |
* a few key bits are stashed in ASCII. If we try to compare those pieces
|
71 |
* to the char they represent, it will fail on any non-ASCII (eg, EBCDIC)
|
72 |
* system. To accomodate these systems, we test against the numeric value
|
73 |
* of the ASCII characters instead of the characters themselves. This is
|
74 |
* encoding independant.
|
75 |
*/
|
76 |
|
77 |
# define GIF87a "\x47\x49\x46\x38\x37\x61" /* ASCII GIF87a */
|
78 |
# define GIF89a "\x47\x49\x46\x38\x39\x61" /* ASCII GIF89a */
|
79 |
# define GIF_TERMINATOR 0x3b /* ASCII ; */
|
80 |
# define GIF_EXTENSION 0x21 /* ASCII ! */
|
81 |
# define GIF_START 0x2c /* ASCII , */
|
82 |
|
83 |
/*
|
84 |
* HACK ALERT!! HACK ALERT!! HACK ALERT!!
|
85 |
* This code is hard-wired for reading from files. In order to read
|
86 |
* from a data stream, we'll trick fread so we can reuse the same code.
|
87 |
* 0==from file; 1==from base64 encoded data; 2==from binary data
|
88 |
*/
|
89 |
|
90 |
typedef struct ThreadSpecificData {
|
91 |
int fromData;
|
92 |
} ThreadSpecificData;
|
93 |
static Tcl_ThreadDataKey dataKey;
|
94 |
|
95 |
/*
|
96 |
* The format record for the GIF file format:
|
97 |
*/
|
98 |
|
99 |
static int FileMatchGIF _ANSI_ARGS_((Tcl_Channel chan, CONST char *fileName,
|
100 |
Tcl_Obj *format, int *widthPtr, int *heightPtr,
|
101 |
Tcl_Interp *interp));
|
102 |
static int FileReadGIF _ANSI_ARGS_((Tcl_Interp *interp,
|
103 |
Tcl_Channel chan, CONST char *fileName, Tcl_Obj *format,
|
104 |
Tk_PhotoHandle imageHandle, int destX, int destY,
|
105 |
int width, int height, int srcX, int srcY));
|
106 |
static int StringMatchGIF _ANSI_ARGS_(( Tcl_Obj *dataObj,
|
107 |
Tcl_Obj *format, int *widthPtr, int *heightPtr,
|
108 |
Tcl_Interp *interp));
|
109 |
static int StringReadGIF _ANSI_ARGS_((Tcl_Interp *interp, Tcl_Obj *dataObj,
|
110 |
Tcl_Obj *format, Tk_PhotoHandle imageHandle,
|
111 |
int destX, int destY, int width, int height,
|
112 |
int srcX, int srcY));
|
113 |
static int FileWriteGIF _ANSI_ARGS_((Tcl_Interp *interp,
|
114 |
CONST char *filename, Tcl_Obj *format,
|
115 |
Tk_PhotoImageBlock *blockPtr));
|
116 |
static int CommonWriteGIF _ANSI_ARGS_((Tcl_Interp *interp,
|
117 |
Tcl_Channel handle, Tcl_Obj *format,
|
118 |
Tk_PhotoImageBlock *blockPtr));
|
119 |
|
120 |
Tk_PhotoImageFormat tkImgFmtGIF = {
|
121 |
"gif", /* name */
|
122 |
FileMatchGIF, /* fileMatchProc */
|
123 |
StringMatchGIF, /* stringMatchProc */
|
124 |
FileReadGIF, /* fileReadProc */
|
125 |
StringReadGIF, /* stringReadProc */
|
126 |
FileWriteGIF, /* fileWriteProc */
|
127 |
NULL, /* stringWriteProc */
|
128 |
};
|
129 |
|
130 |
#define INTERLACE 0x40
|
131 |
#define LOCALCOLORMAP 0x80
|
132 |
#define BitSet(byte, bit) (((byte) & (bit)) == (bit))
|
133 |
#define MAXCOLORMAPSIZE 256
|
134 |
#define CM_RED 0
|
135 |
#define CM_GREEN 1
|
136 |
#define CM_BLUE 2
|
137 |
#define CM_ALPHA 3
|
138 |
#define MAX_LWZ_BITS 12
|
139 |
#define LM_to_uint(a,b) (((b)<<8)|(a))
|
140 |
#define ReadOK(file,buffer,len) (Fread(buffer, len, 1, file) != 0)
|
141 |
|
142 |
/*
|
143 |
* Prototypes for local procedures defined in this file:
|
144 |
*/
|
145 |
|
146 |
static int DoExtension _ANSI_ARGS_((Tcl_Channel chan, int label,
|
147 |
int *transparent));
|
148 |
static int GetCode _ANSI_ARGS_((Tcl_Channel chan, int code_size,
|
149 |
int flag));
|
150 |
static int GetDataBlock _ANSI_ARGS_((Tcl_Channel chan,
|
151 |
unsigned char *buf));
|
152 |
static int ReadColorMap _ANSI_ARGS_((Tcl_Channel chan, int number,
|
153 |
unsigned char buffer[MAXCOLORMAPSIZE][4]));
|
154 |
static int ReadGIFHeader _ANSI_ARGS_((Tcl_Channel chan,
|
155 |
int *widthPtr, int *heightPtr));
|
156 |
static int ReadImage _ANSI_ARGS_((Tcl_Interp *interp,
|
157 |
char *imagePtr, Tcl_Channel chan,
|
158 |
int len, int rows,
|
159 |
unsigned char cmap[MAXCOLORMAPSIZE][4],
|
160 |
int width, int height, int srcX, int srcY,
|
161 |
int interlace, int transparent));
|
162 |
|
163 |
/*
|
164 |
* these are for the BASE64 image reader code only
|
165 |
*/
|
166 |
|
167 |
static int Fread _ANSI_ARGS_((unsigned char *dst, size_t size,
|
168 |
size_t count, Tcl_Channel chan));
|
169 |
static int Mread _ANSI_ARGS_((unsigned char *dst, size_t size,
|
170 |
size_t count, MFile *handle));
|
171 |
static int Mgetc _ANSI_ARGS_((MFile *handle));
|
172 |
static int char64 _ANSI_ARGS_((int c));
|
173 |
static void mInit _ANSI_ARGS_((unsigned char *string,
|
174 |
MFile *handle));
|
175 |
|
176 |
|
177 |
/*
|
178 |
*----------------------------------------------------------------------
|
179 |
*
|
180 |
* FileMatchGIF --
|
181 |
*
|
182 |
* This procedure is invoked by the photo image type to see if
|
183 |
* a file contains image data in GIF format.
|
184 |
*
|
185 |
* Results:
|
186 |
* The return value is 1 if the first characters in file f look
|
187 |
* like GIF data, and 0 otherwise.
|
188 |
*
|
189 |
* Side effects:
|
190 |
* The access position in f may change.
|
191 |
*
|
192 |
*----------------------------------------------------------------------
|
193 |
*/
|
194 |
|
195 |
static int
|
196 |
FileMatchGIF(chan, fileName, format, widthPtr, heightPtr, interp)
|
197 |
Tcl_Channel chan; /* The image file, open for reading. */
|
198 |
CONST char *fileName; /* The name of the image file. */
|
199 |
Tcl_Obj *format; /* User-specified format object, or NULL. */
|
200 |
int *widthPtr, *heightPtr; /* The dimensions of the image are
|
201 |
* returned here if the file is a valid
|
202 |
* raw GIF file. */
|
203 |
Tcl_Interp *interp; /* not used */
|
204 |
{
|
205 |
return ReadGIFHeader(chan, widthPtr, heightPtr);
|
206 |
}
|
207 |
|
208 |
/*
|
209 |
*----------------------------------------------------------------------
|
210 |
*
|
211 |
* FileReadGIF --
|
212 |
*
|
213 |
* This procedure is called by the photo image type to read
|
214 |
* GIF format data from a file and write it into a given
|
215 |
* photo image.
|
216 |
*
|
217 |
* Results:
|
218 |
* A standard TCL completion code. If TCL_ERROR is returned
|
219 |
* then an error message is left in the interp's result.
|
220 |
*
|
221 |
* Side effects:
|
222 |
* The access position in file f is changed, and new data is
|
223 |
* added to the image given by imageHandle.
|
224 |
*
|
225 |
*----------------------------------------------------------------------
|
226 |
*/
|
227 |
|
228 |
static int
|
229 |
FileReadGIF(interp, chan, fileName, format, imageHandle, destX, destY,
|
230 |
width, height, srcX, srcY)
|
231 |
Tcl_Interp *interp; /* Interpreter to use for reporting errors. */
|
232 |
Tcl_Channel chan; /* The image file, open for reading. */
|
233 |
CONST char *fileName; /* The name of the image file. */
|
234 |
Tcl_Obj *format; /* User-specified format object, or NULL. */
|
235 |
Tk_PhotoHandle imageHandle; /* The photo image to write into. */
|
236 |
int destX, destY; /* Coordinates of top-left pixel in
|
237 |
* photo image to be written to. */
|
238 |
int width, height; /* Dimensions of block of photo image to
|
239 |
* be written to. */
|
240 |
int srcX, srcY; /* Coordinates of top-left pixel to be used
|
241 |
* in image being read. */
|
242 |
{
|
243 |
int fileWidth, fileHeight;
|
244 |
int nBytes, index = 0, argc = 0, i;
|
245 |
Tcl_Obj **objv;
|
246 |
Tk_PhotoImageBlock block;
|
247 |
unsigned char buf[100];
|
248 |
unsigned char *trashBuffer = NULL;
|
249 |
int bitPixel;
|
250 |
unsigned char colorMap[MAXCOLORMAPSIZE][4];
|
251 |
int transparent = -1;
|
252 |
static char *optionStrings[] = {
|
253 |
"-index", NULL
|
254 |
};
|
255 |
|
256 |
if (format && Tcl_ListObjGetElements(interp, format,
|
257 |
&argc, &objv) != TCL_OK) {
|
258 |
return TCL_ERROR;
|
259 |
}
|
260 |
for (i = 1; i < argc; i++) {
|
261 |
if (Tcl_GetIndexFromObj(interp, objv[i], optionStrings, "option name", 0,
|
262 |
&nBytes) != TCL_OK) {
|
263 |
return TCL_ERROR;
|
264 |
}
|
265 |
if (i == (argc-1)) {
|
266 |
Tcl_AppendResult(interp, "no value given for \"",
|
267 |
Tcl_GetStringFromObj(objv[i], NULL),
|
268 |
"\" option", (char *) NULL);
|
269 |
return TCL_ERROR;
|
270 |
}
|
271 |
if (Tcl_GetIntFromObj(interp, objv[++i], &index) != TCL_OK) {
|
272 |
return TCL_ERROR;
|
273 |
}
|
274 |
}
|
275 |
if (!ReadGIFHeader(chan, &fileWidth, &fileHeight)) {
|
276 |
Tcl_AppendResult(interp, "couldn't read GIF header from file \"",
|
277 |
fileName, "\"", NULL);
|
278 |
return TCL_ERROR;
|
279 |
}
|
280 |
if ((fileWidth <= 0) || (fileHeight <= 0)) {
|
281 |
Tcl_AppendResult(interp, "GIF image file \"", fileName,
|
282 |
"\" has dimension(s) <= 0", (char *) NULL);
|
283 |
return TCL_ERROR;
|
284 |
}
|
285 |
|
286 |
if (Fread(buf, 1, 3, chan) != 3) {
|
287 |
return TCL_OK;
|
288 |
}
|
289 |
bitPixel = 2<<(buf[0]&0x07);
|
290 |
|
291 |
if (BitSet(buf[0], LOCALCOLORMAP)) { /* Global Colormap */
|
292 |
if (!ReadColorMap(chan, bitPixel, colorMap)) {
|
293 |
Tcl_AppendResult(interp, "error reading color map",
|
294 |
(char *) NULL);
|
295 |
return TCL_ERROR;
|
296 |
}
|
297 |
}
|
298 |
|
299 |
if ((srcX + width) > fileWidth) {
|
300 |
width = fileWidth - srcX;
|
301 |
}
|
302 |
if ((srcY + height) > fileHeight) {
|
303 |
height = fileHeight - srcY;
|
304 |
}
|
305 |
if ((width <= 0) || (height <= 0)
|
306 |
|| (srcX >= fileWidth) || (srcY >= fileHeight)) {
|
307 |
return TCL_OK;
|
308 |
}
|
309 |
|
310 |
Tk_PhotoExpand(imageHandle, destX + width, destY + height);
|
311 |
|
312 |
block.width = width;
|
313 |
block.height = height;
|
314 |
block.pixelSize = 4;
|
315 |
block.pitch = block.pixelSize * block.width;
|
316 |
block.offset[0] = 0;
|
317 |
block.offset[1] = 1;
|
318 |
block.offset[2] = 2;
|
319 |
block.offset[3] = 3;
|
320 |
block.pixelPtr = NULL;
|
321 |
|
322 |
while (1) {
|
323 |
if (Fread(buf, 1, 1, chan) != 1) {
|
324 |
/*
|
325 |
* Premature end of image. We should really notify
|
326 |
* the user, but for now just show garbage.
|
327 |
*/
|
328 |
|
329 |
break;
|
330 |
}
|
331 |
|
332 |
if (buf[0] == GIF_TERMINATOR) {
|
333 |
/*
|
334 |
* GIF terminator.
|
335 |
*/
|
336 |
|
337 |
Tcl_AppendResult(interp,"no image data for this index",
|
338 |
(char *) NULL);
|
339 |
goto error;
|
340 |
}
|
341 |
|
342 |
if (buf[0] == GIF_EXTENSION) {
|
343 |
/*
|
344 |
* This is a GIF extension.
|
345 |
*/
|
346 |
|
347 |
if (Fread(buf, 1, 1, chan) != 1) {
|
348 |
Tcl_SetResult(interp,
|
349 |
"error reading extension function code in GIF image",
|
350 |
TCL_STATIC);
|
351 |
goto error;
|
352 |
}
|
353 |
if (DoExtension(chan, buf[0], &transparent) < 0) {
|
354 |
Tcl_SetResult(interp, "error reading extension in GIF image",
|
355 |
TCL_STATIC);
|
356 |
goto error;
|
357 |
}
|
358 |
continue;
|
359 |
}
|
360 |
|
361 |
if (buf[0] != GIF_START) {
|
362 |
/*
|
363 |
* Not a valid start character; ignore it.
|
364 |
*/
|
365 |
continue;
|
366 |
}
|
367 |
|
368 |
if (Fread(buf, 1, 9, chan) != 9) {
|
369 |
Tcl_SetResult(interp,
|
370 |
"couldn't read left/top/width/height in GIF image",
|
371 |
TCL_STATIC);
|
372 |
goto error;
|
373 |
}
|
374 |
|
375 |
fileWidth = LM_to_uint(buf[4],buf[5]);
|
376 |
fileHeight = LM_to_uint(buf[6],buf[7]);
|
377 |
|
378 |
bitPixel = 1<<((buf[8]&0x07)+1);
|
379 |
|
380 |
if (index--) {
|
381 |
/* this is not the image we want to read: skip it. */
|
382 |
if (BitSet(buf[8], LOCALCOLORMAP)) {
|
383 |
if (!ReadColorMap(chan, bitPixel, colorMap)) {
|
384 |
Tcl_AppendResult(interp,
|
385 |
"error reading color map", (char *) NULL);
|
386 |
goto error;
|
387 |
}
|
388 |
}
|
389 |
|
390 |
/* If we've not yet allocated a trash buffer, do so now */
|
391 |
if (trashBuffer == NULL) {
|
392 |
nBytes = fileWidth * fileHeight * 3;
|
393 |
trashBuffer =
|
394 |
(unsigned char *) ckalloc((unsigned int) nBytes);
|
395 |
}
|
396 |
|
397 |
/*
|
398 |
* Slurp! Process the data for this image and stuff it in a
|
399 |
* trash buffer.
|
400 |
*
|
401 |
* Yes, it might be more efficient here to *not* store the data
|
402 |
* (we're just going to throw it away later). However, I elected
|
403 |
* to implement it this way for good reasons. First, I wanted to
|
404 |
* avoid duplicating the (fairly complex) LWZ decoder in ReadImage.
|
405 |
* Fine, you say, why didn't you just modify it to allow the use of
|
406 |
* a NULL specifier for the output buffer? I tried that, but it
|
407 |
* negatively impacted the performance of what I think will be the
|
408 |
* common case: reading the first image in the file. Rather than
|
409 |
* marginally improve the speed of the less frequent case, I chose
|
410 |
* to maintain high performance for the common case.
|
411 |
*/
|
412 |
if (ReadImage(interp, (char *) trashBuffer, chan, fileWidth,
|
413 |
fileHeight, colorMap, 0, 0, 0, 0, 0, -1) != TCL_OK) {
|
414 |
goto error;
|
415 |
}
|
416 |
continue;
|
417 |
}
|
418 |
|
419 |
/* If a trash buffer has been allocated, free it now */
|
420 |
if (trashBuffer != NULL) {
|
421 |
ckfree((char *)trashBuffer);
|
422 |
trashBuffer = NULL;
|
423 |
}
|
424 |
if (BitSet(buf[8], LOCALCOLORMAP)) {
|
425 |
if (!ReadColorMap(chan, bitPixel, colorMap)) {
|
426 |
Tcl_AppendResult(interp, "error reading color map",
|
427 |
(char *) NULL);
|
428 |
goto error;
|
429 |
}
|
430 |
}
|
431 |
|
432 |
index = LM_to_uint(buf[0],buf[1]);
|
433 |
srcX -= index;
|
434 |
if (srcX<0) {
|
435 |
destX -= srcX; width += srcX;
|
436 |
srcX = 0;
|
437 |
}
|
438 |
|
439 |
if (width > fileWidth) {
|
440 |
width = fileWidth;
|
441 |
}
|
442 |
|
443 |
index = LM_to_uint(buf[2],buf[3]);
|
444 |
srcY -= index;
|
445 |
if (index > srcY) {
|
446 |
destY -= srcY; height += srcY;
|
447 |
srcY = 0;
|
448 |
}
|
449 |
if (height > fileHeight) {
|
450 |
height = fileHeight;
|
451 |
}
|
452 |
|
453 |
if ((width <= 0) || (height <= 0)) {
|
454 |
block.pixelPtr = 0;
|
455 |
goto noerror;
|
456 |
}
|
457 |
|
458 |
block.width = width;
|
459 |
block.height = height;
|
460 |
block.pixelSize = (transparent>=0) ? 4 : 3;
|
461 |
block.offset[3] = (transparent>=0) ? 3 : 0;
|
462 |
block.pitch = block.pixelSize * width;
|
463 |
nBytes = block.pitch * height;
|
464 |
block.pixelPtr = (unsigned char *) ckalloc((unsigned) nBytes);
|
465 |
|
466 |
if (ReadImage(interp, (char *) block.pixelPtr, chan, width,
|
467 |
height, colorMap, fileWidth, fileHeight, srcX, srcY,
|
468 |
BitSet(buf[8], INTERLACE), transparent) != TCL_OK) {
|
469 |
goto error;
|
470 |
}
|
471 |
break;
|
472 |
}
|
473 |
|
474 |
Tk_PhotoPutBlock(imageHandle, &block, destX, destY, width, height);
|
475 |
|
476 |
noerror:
|
477 |
if (block.pixelPtr) {
|
478 |
ckfree((char *) block.pixelPtr);
|
479 |
}
|
480 |
Tcl_AppendResult(interp, tkImgFmtGIF.name, (char *) NULL);
|
481 |
return TCL_OK;
|
482 |
|
483 |
error:
|
484 |
if (block.pixelPtr) {
|
485 |
ckfree((char *) block.pixelPtr);
|
486 |
}
|
487 |
return TCL_ERROR;
|
488 |
|
489 |
}
|
490 |
|
491 |
/*
|
492 |
*----------------------------------------------------------------------
|
493 |
*
|
494 |
* StringMatchGIF --
|
495 |
*
|
496 |
* This procedure is invoked by the photo image type to see if
|
497 |
* an object contains image data in GIF format.
|
498 |
*
|
499 |
* Results:
|
500 |
* The return value is 1 if the first characters in the data are
|
501 |
* like GIF data, and 0 otherwise.
|
502 |
*
|
503 |
* Side effects:
|
504 |
* the size of the image is placed in widthPre and heightPtr.
|
505 |
*
|
506 |
*----------------------------------------------------------------------
|
507 |
*/
|
508 |
|
509 |
static int
|
510 |
StringMatchGIF(dataObj, format, widthPtr, heightPtr, interp)
|
511 |
Tcl_Obj *dataObj; /* the object containing the image data */
|
512 |
Tcl_Obj *format; /* the image format object, or NULL */
|
513 |
int *widthPtr; /* where to put the string width */
|
514 |
int *heightPtr; /* where to put the string height */
|
515 |
Tcl_Interp *interp; /* not used */
|
516 |
{
|
517 |
unsigned char *data, header[10];
|
518 |
int got, length;
|
519 |
MFile handle;
|
520 |
|
521 |
data = Tcl_GetByteArrayFromObj(dataObj, &length);
|
522 |
|
523 |
/* Header is a minimum of 10 bytes */
|
524 |
if (length < 10) {
|
525 |
return 0;
|
526 |
}
|
527 |
|
528 |
/* Check whether the data is Base64 encoded */
|
529 |
|
530 |
if ((strncmp(GIF87a, (char *) data, 6) != 0) &&
|
531 |
(strncmp(GIF89a, (char *) data, 6) != 0)) {
|
532 |
/* Try interpreting the data as Base64 encoded */
|
533 |
mInit((unsigned char *) data, &handle);
|
534 |
got = Mread(header, 10, 1, &handle);
|
535 |
if (got != 10
|
536 |
|| ((strncmp(GIF87a, (char *) header, 6) != 0)
|
537 |
&& (strncmp(GIF89a, (char *) header, 6) != 0))) {
|
538 |
return 0;
|
539 |
}
|
540 |
} else {
|
541 |
memcpy((VOID *) header, (VOID *) data, 10);
|
542 |
}
|
543 |
*widthPtr = LM_to_uint(header[6],header[7]);
|
544 |
*heightPtr = LM_to_uint(header[8],header[9]);
|
545 |
return 1;
|
546 |
}
|
547 |
|
548 |
/*
|
549 |
*----------------------------------------------------------------------
|
550 |
*
|
551 |
* StringReadGif -- --
|
552 |
*
|
553 |
* This procedure is called by the photo image type to read
|
554 |
* GIF format data from an object, optionally base64 encoded,
|
555 |
* and give it to the photo image.
|
556 |
*
|
557 |
* Results:
|
558 |
* A standard TCL completion code. If TCL_ERROR is returned
|
559 |
* then an error message is left in the interp's result.
|
560 |
*
|
561 |
* Side effects:
|
562 |
* new data is added to the image given by imageHandle. This
|
563 |
* procedure calls FileReadGif by redefining the operation of
|
564 |
* fprintf temporarily.
|
565 |
*
|
566 |
*----------------------------------------------------------------------
|
567 |
*/
|
568 |
|
569 |
static int
|
570 |
StringReadGIF(interp, dataObj, format, imageHandle,
|
571 |
destX, destY, width, height, srcX, srcY)
|
572 |
Tcl_Interp *interp; /* interpreter for reporting errors in */
|
573 |
Tcl_Obj *dataObj; /* object containing the image */
|
574 |
Tcl_Obj *format; /* format object, or NULL */
|
575 |
Tk_PhotoHandle imageHandle; /* the image to write this data into */
|
576 |
int destX, destY; /* The rectangular region of the */
|
577 |
int width, height; /* image to copy */
|
578 |
int srcX, srcY;
|
579 |
{
|
580 |
int result;
|
581 |
MFile handle;
|
582 |
ThreadSpecificData *tsdPtr = (ThreadSpecificData *)
|
583 |
Tcl_GetThreadData(&dataKey, sizeof(ThreadSpecificData));
|
584 |
Tcl_Channel dataSrc;
|
585 |
char *data;
|
586 |
|
587 |
/*
|
588 |
* Check whether the data is Base64 encoded
|
589 |
*/
|
590 |
data = (char *) Tcl_GetByteArrayFromObj(dataObj, NULL);
|
591 |
if ((strncmp(GIF87a, data, 6) != 0) &&
|
592 |
(strncmp(GIF89a, data, 6) != 0)) {
|
593 |
mInit((unsigned char *)data, &handle);
|
594 |
tsdPtr->fromData = 1;
|
595 |
dataSrc = (Tcl_Channel) &handle;
|
596 |
} else {
|
597 |
tsdPtr->fromData = 2;
|
598 |
mInit((unsigned char *)data, &handle);
|
599 |
dataSrc = (Tcl_Channel) &handle;
|
600 |
}
|
601 |
result = FileReadGIF(interp, dataSrc, "inline data",
|
602 |
format, imageHandle, destX, destY, width, height, srcX, srcY);
|
603 |
tsdPtr->fromData = 0;
|
604 |
return(result);
|
605 |
}
|
606 |
|
607 |
/*
|
608 |
*----------------------------------------------------------------------
|
609 |
*
|
610 |
* ReadGIFHeader --
|
611 |
*
|
612 |
* This procedure reads the GIF header from the beginning of a
|
613 |
* GIF file and returns the dimensions of the image.
|
614 |
*
|
615 |
* Results:
|
616 |
* The return value is 1 if file "f" appears to start with
|
617 |
* a valid GIF header, 0 otherwise. If the header is valid,
|
618 |
* then *widthPtr and *heightPtr are modified to hold the
|
619 |
* dimensions of the image.
|
620 |
*
|
621 |
* Side effects:
|
622 |
* The access position in f advances.
|
623 |
*
|
624 |
*----------------------------------------------------------------------
|
625 |
*/
|
626 |
|
627 |
static int
|
628 |
ReadGIFHeader(chan, widthPtr, heightPtr)
|
629 |
Tcl_Channel chan; /* Image file to read the header from */
|
630 |
int *widthPtr, *heightPtr; /* The dimensions of the image are
|
631 |
* returned here. */
|
632 |
{
|
633 |
unsigned char buf[7];
|
634 |
|
635 |
if ((Fread(buf, 1, 6, chan) != 6)
|
636 |
|| ((strncmp(GIF87a, (char *) buf, 6) != 0)
|
637 |
&& (strncmp(GIF89a, (char *) buf, 6) != 0))) {
|
638 |
return 0;
|
639 |
}
|
640 |
|
641 |
if (Fread(buf, 1, 4, chan) != 4) {
|
642 |
return 0;
|
643 |
}
|
644 |
|
645 |
*widthPtr = LM_to_uint(buf[0],buf[1]);
|
646 |
*heightPtr = LM_to_uint(buf[2],buf[3]);
|
647 |
return 1;
|
648 |
}
|
649 |
|
650 |
/*
|
651 |
*-----------------------------------------------------------------
|
652 |
* The code below is copied from the giftoppm program and modified
|
653 |
* just slightly.
|
654 |
*-----------------------------------------------------------------
|
655 |
*/
|
656 |
|
657 |
static int
|
658 |
ReadColorMap(chan, number, buffer)
|
659 |
Tcl_Channel chan;
|
660 |
int number;
|
661 |
unsigned char buffer[MAXCOLORMAPSIZE][4];
|
662 |
{
|
663 |
int i;
|
664 |
unsigned char rgb[3];
|
665 |
|
666 |
for (i = 0; i < number; ++i) {
|
667 |
if (! ReadOK(chan, rgb, sizeof(rgb))) {
|
668 |
return 0;
|
669 |
}
|
670 |
|
671 |
if (buffer) {
|
672 |
buffer[i][CM_RED] = rgb[0] ;
|
673 |
buffer[i][CM_GREEN] = rgb[1] ;
|
674 |
buffer[i][CM_BLUE] = rgb[2] ;
|
675 |
buffer[i][CM_ALPHA] = 255 ;
|
676 |
}
|
677 |
}
|
678 |
return 1;
|
679 |
}
|
680 |
|
681 |
|
682 |
|
683 |
static int
|
684 |
DoExtension(chan, label, transparent)
|
685 |
Tcl_Channel chan;
|
686 |
int label;
|
687 |
int *transparent;
|
688 |
{
|
689 |
static unsigned char buf[256];
|
690 |
int count;
|
691 |
|
692 |
switch (label) {
|
693 |
case 0x01: /* Plain Text Extension */
|
694 |
break;
|
695 |
|
696 |
case 0xff: /* Application Extension */
|
697 |
break;
|
698 |
|
699 |
case 0xfe: /* Comment Extension */
|
700 |
do {
|
701 |
count = GetDataBlock(chan, (unsigned char*) buf);
|
702 |
} while (count > 0);
|
703 |
return count;
|
704 |
|
705 |
case 0xf9: /* Graphic Control Extension */
|
706 |
count = GetDataBlock(chan, (unsigned char*) buf);
|
707 |
if (count < 0) {
|
708 |
return 1;
|
709 |
}
|
710 |
if ((buf[0] & 0x1) != 0) {
|
711 |
*transparent = buf[3];
|
712 |
}
|
713 |
|
714 |
do {
|
715 |
count = GetDataBlock(chan, (unsigned char*) buf);
|
716 |
} while (count > 0);
|
717 |
return count;
|
718 |
}
|
719 |
|
720 |
do {
|
721 |
count = GetDataBlock(chan, (unsigned char*) buf);
|
722 |
} while (count > 0);
|
723 |
return count;
|
724 |
}
|
725 |
|
726 |
static int ZeroDataBlock = 0;
|
727 |
|
728 |
static int
|
729 |
GetDataBlock(chan, buf)
|
730 |
Tcl_Channel chan;
|
731 |
unsigned char *buf;
|
732 |
{
|
733 |
unsigned char count;
|
734 |
|
735 |
if (! ReadOK(chan, &count,1)) {
|
736 |
return -1;
|
737 |
}
|
738 |
|
739 |
ZeroDataBlock = count == 0;
|
740 |
|
741 |
if ((count != 0) && (! ReadOK(chan, buf, count))) {
|
742 |
return -1;
|
743 |
}
|
744 |
|
745 |
return count;
|
746 |
}
|
747 |
|
748 |
|
749 |
|
750 |
/*
|
751 |
*----------------------------------------------------------------------
|
752 |
*
|
753 |
* ReadImage --
|
754 |
*
|
755 |
* Process a GIF image from a given source, with a given height,
|
756 |
* width, transparency, etc.
|
757 |
*
|
758 |
* This code is based on the code found in the ImageMagick GIF decoder,
|
759 |
* which is (c) 2000 ImageMagick Studio.
|
760 |
*
|
761 |
* Some thoughts on our implementation:
|
762 |
* It sure would be nice if ReadImage didn't take 11 parameters! I think
|
763 |
* that if we were smarter, we could avoid doing that.
|
764 |
*
|
765 |
* Possible further optimizations: we could pull the GetCode function
|
766 |
* directly into ReadImage, which would improve our speed.
|
767 |
*
|
768 |
* Results:
|
769 |
* Processes a GIF image and loads the pixel data into a memory array.
|
770 |
*
|
771 |
* Side effects:
|
772 |
* None.
|
773 |
*
|
774 |
*----------------------------------------------------------------------
|
775 |
*/
|
776 |
|
777 |
static int
|
778 |
ReadImage(interp, imagePtr, chan, len, rows, cmap,
|
779 |
width, height, srcX, srcY, interlace, transparent)
|
780 |
Tcl_Interp *interp;
|
781 |
char *imagePtr;
|
782 |
Tcl_Channel chan;
|
783 |
int len, rows;
|
784 |
unsigned char cmap[MAXCOLORMAPSIZE][4];
|
785 |
int width, height;
|
786 |
int srcX, srcY;
|
787 |
int interlace;
|
788 |
int transparent;
|
789 |
{
|
790 |
unsigned char initialCodeSize;
|
791 |
int v;
|
792 |
int xpos = 0, ypos = 0, pass = 0, i;
|
793 |
register char *pixelPtr;
|
794 |
CONST static int interlaceStep[] = { 8, 8, 4, 2 };
|
795 |
CONST static int interlaceStart[] = { 0, 4, 2, 1 };
|
796 |
unsigned short prefix[(1 << MAX_LWZ_BITS)];
|
797 |
unsigned char append[(1 << MAX_LWZ_BITS)];
|
798 |
unsigned char stack[(1 << MAX_LWZ_BITS)*2];
|
799 |
register unsigned char *top;
|
800 |
int codeSize, clearCode, inCode, endCode, oldCode, maxCode,
|
801 |
code, firstCode;
|
802 |
|
803 |
/*
|
804 |
* Initialize the decoder
|
805 |
*/
|
806 |
if (! ReadOK(chan, &initialCodeSize, 1)) {
|
807 |
Tcl_AppendResult(interp, "error reading GIF image: ",
|
808 |
Tcl_PosixError(interp), (char *) NULL);
|
809 |
return TCL_ERROR;
|
810 |
}
|
811 |
if (transparent!=-1) {
|
812 |
cmap[transparent][CM_RED] = 0;
|
813 |
cmap[transparent][CM_GREEN] = 0;
|
814 |
cmap[transparent][CM_BLUE] = 0;
|
815 |
cmap[transparent][CM_ALPHA] = 0;
|
816 |
}
|
817 |
|
818 |
pixelPtr = imagePtr;
|
819 |
|
820 |
/* Initialize the decoder */
|
821 |
/* Set values for "special" numbers:
|
822 |
* clear code reset the decoder
|
823 |
* end code stop decoding
|
824 |
* code size size of the next code to retrieve
|
825 |
* max code next available table position
|
826 |
*/
|
827 |
clearCode = 1 << (int) initialCodeSize;
|
828 |
endCode = clearCode + 1;
|
829 |
codeSize = (int) initialCodeSize + 1;
|
830 |
maxCode = clearCode + 2;
|
831 |
oldCode = -1;
|
832 |
firstCode = -1;
|
833 |
|
834 |
memset((void *)prefix, 0, (1 << MAX_LWZ_BITS) * sizeof(short));
|
835 |
memset((void *)append, 0, (1 << MAX_LWZ_BITS) * sizeof(char));
|
836 |
for (i = 0; i < clearCode; i++) {
|
837 |
append[i] = i;
|
838 |
}
|
839 |
top = stack;
|
840 |
|
841 |
GetCode(chan, 0, 1);
|
842 |
|
843 |
/* Read until we finish the image */
|
844 |
for (i = 0, ypos = 0; i < rows; i++) {
|
845 |
for (xpos = 0; xpos < len; ) {
|
846 |
|
847 |
if (top == stack) {
|
848 |
/* Bummer -- our stack is empty. Now we have to work! */
|
849 |
code = GetCode(chan, codeSize, 0);
|
850 |
if (code < 0) {
|
851 |
return TCL_OK;
|
852 |
}
|
853 |
|
854 |
if (code > maxCode || code == endCode) {
|
855 |
/*
|
856 |
* If we're doing things right, we should never
|
857 |
* receive a code that is greater than our current
|
858 |
* maximum code. If we do, bail, because our decoder
|
859 |
* does not yet have that code set up.
|
860 |
*
|
861 |
* If the code is the magic endCode value, quit.
|
862 |
*/
|
863 |
return TCL_OK;
|
864 |
}
|
865 |
|
866 |
if (code == clearCode) {
|
867 |
/* Reset the decoder */
|
868 |
codeSize = initialCodeSize + 1;
|
869 |
maxCode = clearCode + 2;
|
870 |
oldCode = -1;
|
871 |
continue;
|
872 |
}
|
873 |
|
874 |
if (oldCode == -1) {
|
875 |
/*
|
876 |
* Last pass reset the decoder, so the first code we
|
877 |
* see must be a singleton. Seed the stack with it,
|
878 |
* and set up the old/first code pointers for
|
879 |
* insertion into the string table. We can't just
|
880 |
* roll this into the clearCode test above, because
|
881 |
* at that point we have not yet read the next code.
|
882 |
*/
|
883 |
*top++=append[code];
|
884 |
oldCode = code;
|
885 |
firstCode = code;
|
886 |
continue;
|
887 |
}
|
888 |
|
889 |
inCode = code;
|
890 |
|
891 |
if (code == maxCode) {
|
892 |
/*
|
893 |
* maxCode is always one bigger than our highest assigned
|
894 |
* code. If the code we see is equal to maxCode, then
|
895 |
* we are about to add a new string to the table. ???
|
896 |
*/
|
897 |
*top++ = firstCode;
|
898 |
code = oldCode;
|
899 |
}
|
900 |
|
901 |
while (code > clearCode) {
|
902 |
/*
|
903 |
* Populate the stack by tracing the string in the
|
904 |
* string table from its tail to its head
|
905 |
*/
|
906 |
*top++ = append[code];
|
907 |
code = prefix[code];
|
908 |
}
|
909 |
firstCode = append[code];
|
910 |
|
911 |
/*
|
912 |
* If there's no more room in our string table, quit.
|
913 |
* Otherwise, add a new string to the table
|
914 |
*/
|
915 |
if (maxCode >= (1 << MAX_LWZ_BITS)) {
|
916 |
return TCL_OK;
|
917 |
}
|
918 |
|
919 |
/* Push the head of the string onto the stack */
|
920 |
*top++ = firstCode;
|
921 |
|
922 |
/* Add a new string to the string table */
|
923 |
prefix[maxCode] = oldCode;
|
924 |
append[maxCode] = firstCode;
|
925 |
maxCode++;
|
926 |
|
927 |
/* maxCode tells us the maximum code value we can accept.
|
928 |
* If we see that we need more bits to represent it than
|
929 |
* we are requesting from the unpacker, we need to increase
|
930 |
* the number we ask for.
|
931 |
*/
|
932 |
if ((maxCode >= (1 << codeSize))
|
933 |
&& (maxCode < (1<<MAX_LWZ_BITS))) {
|
934 |
codeSize++;
|
935 |
}
|
936 |
oldCode = inCode;
|
937 |
}
|
938 |
|
939 |
/* Pop the next color index off the stack */
|
940 |
v = *(--top);
|
941 |
if (v < 0) {
|
942 |
return TCL_OK;
|
943 |
}
|
944 |
|
945 |
/*
|
946 |
* If pixelPtr is null, we're skipping this image (presumably
|
947 |
* there are more in the file and we will be called to read
|
948 |
* one of them later)
|
949 |
*/
|
950 |
*pixelPtr++ = cmap[v][CM_RED];
|
951 |
*pixelPtr++ = cmap[v][CM_GREEN];
|
952 |
*pixelPtr++ = cmap[v][CM_BLUE];
|
953 |
if (transparent >= 0) {
|
954 |
*pixelPtr++ = cmap[v][CM_ALPHA];
|
955 |
}
|
956 |
xpos++;
|
957 |
|
958 |
}
|
959 |
|
960 |
/* If interlacing, the next ypos is not just +1 */
|
961 |
if (interlace) {
|
962 |
ypos += interlaceStep[pass];
|
963 |
while (ypos >= height) {
|
964 |
pass++;
|
965 |
if (pass > 3) {
|
966 |
return TCL_OK;
|
967 |
}
|
968 |
ypos = interlaceStart[pass];
|
969 |
}
|
970 |
} else {
|
971 |
ypos++;
|
972 |
}
|
973 |
pixelPtr = imagePtr + (ypos) * len * ((transparent>=0)?4:3);
|
974 |
}
|
975 |
return TCL_OK;
|
976 |
}
|
977 |
|
978 |
|
979 |
/*
|
980 |
*----------------------------------------------------------------------
|
981 |
*
|
982 |
* GetCode --
|
983 |
*
|
984 |
* Extract the next compression code from the file. In GIF's, the
|
985 |
* compression codes are between 3 and 12 bits long and are then
|
986 |
* packed into 8 bit bytes, left to right, for example:
|
987 |
* bbbaaaaa
|
988 |
* dcccccbb
|
989 |
* eeeedddd
|
990 |
* ...
|
991 |
* We use a byte buffer read from the file and a sliding window
|
992 |
* to unpack the bytes. Thanks to ImageMagick for the sliding window
|
993 |
* idea.
|
994 |
* args: chan the channel to read from
|
995 |
* code_size size of the code to extract
|
996 |
* flag boolean indicating whether the extractor
|
997 |
* should be reset or not
|
998 |
*
|
999 |
* Results:
|
1000 |
* code the next compression code
|
1001 |
*
|
1002 |
* Side effects:
|
1003 |
* May consume more input from chan.
|
1004 |
*
|
1005 |
*----------------------------------------------------------------------
|
1006 |
*/
|
1007 |
|
1008 |
static int
|
1009 |
GetCode(chan, code_size, flag)
|
1010 |
Tcl_Channel chan;
|
1011 |
int code_size;
|
1012 |
int flag;
|
1013 |
{
|
1014 |
static unsigned char buf[280];
|
1015 |
static int bytes = 0, done;
|
1016 |
static unsigned char *c;
|
1017 |
|
1018 |
static unsigned int window;
|
1019 |
static int bitsInWindow = 0;
|
1020 |
int ret;
|
1021 |
|
1022 |
if (flag) {
|
1023 |
/* Initialize the decoder */
|
1024 |
bitsInWindow = 0;
|
1025 |
bytes = 0;
|
1026 |
window = 0;
|
1027 |
done = 0;
|
1028 |
c = NULL;
|
1029 |
return 0;
|
1030 |
}
|
1031 |
|
1032 |
while (bitsInWindow < code_size) {
|
1033 |
/* Not enough bits in our window to cover the request */
|
1034 |
if (done) {
|
1035 |
return -1;
|
1036 |
}
|
1037 |
if (bytes == 0) {
|
1038 |
/* Not enough bytes in our buffer to add to the window */
|
1039 |
bytes = GetDataBlock(chan, buf);
|
1040 |
c = buf;
|
1041 |
if (bytes <= 0) {
|
1042 |
done = 1;
|
1043 |
break;
|
1044 |
}
|
1045 |
}
|
1046 |
/* Tack another byte onto the window, see if that's enough */
|
1047 |
window += (*c) << bitsInWindow;
|
1048 |
c++;
|
1049 |
bitsInWindow += 8;
|
1050 |
bytes--;
|
1051 |
}
|
1052 |
|
1053 |
|
1054 |
/* The next code will always be the last code_size bits of the window */
|
1055 |
ret = window & ((1 << code_size) - 1);
|
1056 |
|
1057 |
/* Shift data in the window to put the next code at the end */
|
1058 |
window >>= code_size;
|
1059 |
bitsInWindow -= code_size;
|
1060 |
return ret;
|
1061 |
}
|
1062 |
|
1063 |
/*
|
1064 |
*----------------------------------------------------------------------
|
1065 |
*
|
1066 |
* Minit -- --
|
1067 |
*
|
1068 |
* This procedure initializes a base64 decoder handle
|
1069 |
*
|
1070 |
* Results:
|
1071 |
* none
|
1072 |
*
|
1073 |
* Side effects:
|
1074 |
* the base64 handle is initialized
|
1075 |
*
|
1076 |
*----------------------------------------------------------------------
|
1077 |
*/
|
1078 |
|
1079 |
static void
|
1080 |
mInit(string, handle)
|
1081 |
unsigned char *string; /* string containing initial mmencoded data */
|
1082 |
MFile *handle; /* mmdecode "file" handle */
|
1083 |
{
|
1084 |
handle->data = string;
|
1085 |
handle->state = 0;
|
1086 |
}
|
1087 |
|
1088 |
/*
|
1089 |
*----------------------------------------------------------------------
|
1090 |
*
|
1091 |
* Mread --
|
1092 |
*
|
1093 |
* This procedure is invoked by the GIF file reader as a
|
1094 |
* temporary replacement for "fread", to get GIF data out
|
1095 |
* of a string (using Mgetc).
|
1096 |
*
|
1097 |
* Results:
|
1098 |
* The return value is the number of characters "read"
|
1099 |
*
|
1100 |
* Side effects:
|
1101 |
* The base64 handle will change state.
|
1102 |
*
|
1103 |
*----------------------------------------------------------------------
|
1104 |
*/
|
1105 |
|
1106 |
static int
|
1107 |
Mread(dst, chunkSize, numChunks, handle)
|
1108 |
unsigned char *dst; /* where to put the result */
|
1109 |
size_t chunkSize; /* size of each transfer */
|
1110 |
size_t numChunks; /* number of chunks */
|
1111 |
MFile *handle; /* mmdecode "file" handle */
|
1112 |
{
|
1113 |
register int i, c;
|
1114 |
int count = chunkSize * numChunks;
|
1115 |
|
1116 |
for(i=0; i<count && (c=Mgetc(handle)) != GIF_DONE; i++) {
|
1117 |
*dst++ = c;
|
1118 |
}
|
1119 |
return i;
|
1120 |
}
|
1121 |
|
1122 |
/*
|
1123 |
* get the next decoded character from an mmencode handle
|
1124 |
* This causes at least 1 character to be "read" from the encoded string
|
1125 |
*/
|
1126 |
|
1127 |
/*
|
1128 |
*----------------------------------------------------------------------
|
1129 |
*
|
1130 |
* Mgetc --
|
1131 |
*
|
1132 |
* This procedure decodes and returns the next byte from a base64
|
1133 |
* encoded string.
|
1134 |
*
|
1135 |
* Results:
|
1136 |
* The next byte (or GIF_DONE) is returned.
|
1137 |
*
|
1138 |
* Side effects:
|
1139 |
* The base64 handle will change state.
|
1140 |
*
|
1141 |
*----------------------------------------------------------------------
|
1142 |
*/
|
1143 |
|
1144 |
static int
|
1145 |
Mgetc(handle)
|
1146 |
MFile *handle; /* Handle containing decoder data and state. */
|
1147 |
{
|
1148 |
int c;
|
1149 |
int result = 0; /* Initialization needed only to prevent
|
1150 |
* gcc compiler warning. */
|
1151 |
|
1152 |
if (handle->state == GIF_DONE) {
|
1153 |
return(GIF_DONE);
|
1154 |
}
|
1155 |
|
1156 |
do {
|
1157 |
c = char64(*handle->data);
|
1158 |
handle->data++;
|
1159 |
} while (c==GIF_SPACE);
|
1160 |
|
1161 |
if (c>GIF_SPECIAL) {
|
1162 |
handle->state = GIF_DONE;
|
1163 |
return(handle->state ? handle->c : GIF_DONE);
|
1164 |
}
|
1165 |
|
1166 |
switch (handle->state++) {
|
1167 |
case 0:
|
1168 |
handle->c = c<<2;
|
1169 |
result = Mgetc(handle);
|
1170 |
break;
|
1171 |
case 1:
|
1172 |
result = handle->c | (c>>4);
|
1173 |
handle->c = (c&0xF)<<4;
|
1174 |
break;
|
1175 |
case 2:
|
1176 |
result = handle->c | (c>>2);
|
1177 |
handle->c = (c&0x3) << 6;
|
1178 |
break;
|
1179 |
case 3:
|
1180 |
result = handle->c | c;
|
1181 |
handle->state = 0;
|
1182 |
break;
|
1183 |
}
|
1184 |
return(result);
|
1185 |
}
|
1186 |
|
1187 |
/*
|
1188 |
*----------------------------------------------------------------------
|
1189 |
*
|
1190 |
* char64 --
|
1191 |
*
|
1192 |
* This procedure converts a base64 ascii character into its binary
|
1193 |
* equivalent. This code is a slightly modified version of the
|
1194 |
* char64 proc in N. Borenstein's metamail decoder.
|
1195 |
*
|
1196 |
* Results:
|
1197 |
* The binary value, or an error code.
|
1198 |
*
|
1199 |
* Side effects:
|
1200 |
* None.
|
1201 |
*----------------------------------------------------------------------
|
1202 |
*/
|
1203 |
|
1204 |
static int
|
1205 |
char64(c)
|
1206 |
int c;
|
1207 |
{
|
1208 |
switch(c) {
|
1209 |
case 'A': return(0); case 'B': return(1); case 'C': return(2);
|
1210 |
case 'D': return(3); case 'E': return(4); case 'F': return(5);
|
1211 |
case 'G': return(6); case 'H': return(7); case 'I': return(8);
|
1212 |
case 'J': return(9); case 'K': return(10); case 'L': return(11);
|
1213 |
case 'M': return(12); case 'N': return(13); case 'O': return(14);
|
1214 |
case 'P': return(15); case 'Q': return(16); case 'R': return(17);
|
1215 |
case 'S': return(18); case 'T': return(19); case 'U': return(20);
|
1216 |
case 'V': return(21); case 'W': return(22); case 'X': return(23);
|
1217 |
case 'Y': return(24); case 'Z': return(25); case 'a': return(26);
|
1218 |
case 'b': return(27); case 'c': return(28); case 'd': return(29);
|
1219 |
case 'e': return(30); case 'f': return(31); case 'g': return(32);
|
1220 |
case 'h': return(33); case 'i': return(34); case 'j': return(35);
|
1221 |
case 'k': return(36); case 'l': return(37); case 'm': return(38);
|
1222 |
case 'n': return(39); case 'o': return(40); case 'p': return(41);
|
1223 |
case 'q': return(42); case 'r': return(43); case 's': return(44);
|
1224 |
case 't': return(45); case 'u': return(46); case 'v': return(47);
|
1225 |
case 'w': return(48); case 'x': return(49); case 'y': return(50);
|
1226 |
case 'z': return(51); case '0': return(52); case '1': return(53);
|
1227 |
case '2': return(54); case '3': return(55); case '4': return(56);
|
1228 |
case '5': return(57); case '6': return(58); case '7': return(59);
|
1229 |
case '8': return(60); case '9': return(61); case '+': return(62);
|
1230 |
case '/': return(63);
|
1231 |
|
1232 |
case ' ': case '\t': case '\n': case '\r': case '\f': return(GIF_SPACE);
|
1233 |
case '=': return(GIF_PAD);
|
1234 |
case '\0': return(GIF_DONE);
|
1235 |
default: return(GIF_BAD);
|
1236 |
}
|
1237 |
}
|
1238 |
|
1239 |
/*
|
1240 |
*----------------------------------------------------------------------
|
1241 |
*
|
1242 |
* Fread --
|
1243 |
*
|
1244 |
* This procedure calls either fread or Mread to read data
|
1245 |
* from a file or a base64 encoded string.
|
1246 |
*
|
1247 |
* Results: - same as fread
|
1248 |
*
|
1249 |
*----------------------------------------------------------------------
|
1250 |
*/
|
1251 |
|
1252 |
static int
|
1253 |
Fread(dst, hunk, count, chan)
|
1254 |
unsigned char *dst; /* where to put the result */
|
1255 |
size_t hunk,count; /* how many */
|
1256 |
Tcl_Channel chan;
|
1257 |
{
|
1258 |
ThreadSpecificData *tsdPtr = (ThreadSpecificData *)
|
1259 |
Tcl_GetThreadData(&dataKey, sizeof(ThreadSpecificData));
|
1260 |
MFile *handle;
|
1261 |
|
1262 |
switch (tsdPtr->fromData) {
|
1263 |
case 1:
|
1264 |
return(Mread(dst, hunk, count, (MFile *) chan));
|
1265 |
case 2:
|
1266 |
handle = (MFile *) chan;
|
1267 |
memcpy((VOID *)dst, (VOID *) handle->data, (size_t) (hunk * count));
|
1268 |
handle->data += hunk * count;
|
1269 |
return((int) (hunk * count));
|
1270 |
default:
|
1271 |
return Tcl_Read(chan, (char *) dst, (int) (hunk * count));
|
1272 |
}
|
1273 |
}
|
1274 |
|
1275 |
|
1276 |
/*
|
1277 |
* ChanWriteGIF - writes a image in GIF format.
|
1278 |
*-------------------------------------------------------------------------
|
1279 |
* Author: Lolo
|
1280 |
* Engeneering Projects Area
|
1281 |
* Department of Mining
|
1282 |
* University of Oviedo
|
1283 |
* e-mail zz11425958@zeus.etsimo.uniovi.es
|
1284 |
* lolo@pcsig22.etsimo.uniovi.es
|
1285 |
* Date: Fri September 20 1996
|
1286 |
*
|
1287 |
* Modified for transparency handling (gif89a) and miGIF compression
|
1288 |
* by Jan Nijtmans <j.nijtmans@chello.nl>
|
1289 |
*
|
1290 |
*----------------------------------------------------------------------
|
1291 |
* FileWriteGIF-
|
1292 |
*
|
1293 |
* This procedure is called by the photo image type to write
|
1294 |
* GIF format data from a photo image into a given file
|
1295 |
*
|
1296 |
* Results:
|
1297 |
* A standard TCL completion code. If TCL_ERROR is returned
|
1298 |
* then an error message is left in interp->result.
|
1299 |
*
|
1300 |
*----------------------------------------------------------------------
|
1301 |
*/
|
1302 |
|
1303 |
/*
|
1304 |
* Types, defines and variables needed to write and compress a GIF.
|
1305 |
*/
|
1306 |
|
1307 |
typedef int (* ifunptr) _ANSI_ARGS_((void));
|
1308 |
|
1309 |
#define LSB(a) ((unsigned char) (((short)(a)) & 0x00FF))
|
1310 |
#define MSB(a) ((unsigned char) (((short)(a)) >> 8))
|
1311 |
|
1312 |
#define GIFBITS 12
|
1313 |
#define HSIZE 5003 /* 80% occupancy */
|
1314 |
|
1315 |
static int ssize;
|
1316 |
static int csize;
|
1317 |
static int rsize;
|
1318 |
static unsigned char *pixelo;
|
1319 |
static int pixelSize;
|
1320 |
static int pixelPitch;
|
1321 |
static int greenOffset;
|
1322 |
static int blueOffset;
|
1323 |
static int alphaOffset;
|
1324 |
static int num;
|
1325 |
static unsigned char mapa[MAXCOLORMAPSIZE][3];
|
1326 |
|
1327 |
/*
|
1328 |
* Definition of new functions to write GIFs
|
1329 |
*/
|
1330 |
|
1331 |
static int color _ANSI_ARGS_((int red,int green, int blue));
|
1332 |
static void compress _ANSI_ARGS_((int init_bits, Tcl_Channel handle,
|
1333 |
ifunptr readValue));
|
1334 |
static int nuevo _ANSI_ARGS_((int red, int green ,int blue,
|
1335 |
unsigned char mapa[MAXCOLORMAPSIZE][3]));
|
1336 |
static int savemap _ANSI_ARGS_((Tk_PhotoImageBlock *blockPtr,
|
1337 |
unsigned char mapa[MAXCOLORMAPSIZE][3]));
|
1338 |
static int ReadValue _ANSI_ARGS_((void));
|
1339 |
static int no_bits _ANSI_ARGS_((int colors));
|
1340 |
|
1341 |
static int
|
1342 |
FileWriteGIF (interp, filename, format, blockPtr)
|
1343 |
Tcl_Interp *interp; /* Interpreter to use for reporting errors. */
|
1344 |
CONST char *filename;
|
1345 |
Tcl_Obj *format;
|
1346 |
Tk_PhotoImageBlock *blockPtr;
|
1347 |
{
|
1348 |
Tcl_Channel chan = NULL;
|
1349 |
int result;
|
1350 |
|
1351 |
chan = Tcl_OpenFileChannel(interp, (char *) filename, "w", 0644);
|
1352 |
if (!chan) {
|
1353 |
return TCL_ERROR;
|
1354 |
}
|
1355 |
if (Tcl_SetChannelOption(interp, chan, "-translation", "binary") != TCL_OK) {
|
1356 |
return TCL_ERROR;
|
1357 |
}
|
1358 |
if (Tcl_SetChannelOption(interp, chan, "-encoding", "binary") != TCL_OK) {
|
1359 |
return TCL_ERROR;
|
1360 |
}
|
1361 |
|
1362 |
result = CommonWriteGIF(interp, chan, format, blockPtr);
|
1363 |
if (Tcl_Close(interp, chan) == TCL_ERROR) {
|
1364 |
return TCL_ERROR;
|
1365 |
}
|
1366 |
return result;
|
1367 |
}
|
1368 |
|
1369 |
#define Mputc(c,handle) Tcl_Write(handle,(char *) &c,1)
|
1370 |
|
1371 |
static int
|
1372 |
CommonWriteGIF(interp, handle, format, blockPtr)
|
1373 |
Tcl_Interp *interp;
|
1374 |
Tcl_Channel handle;
|
1375 |
Tcl_Obj *format;
|
1376 |
Tk_PhotoImageBlock *blockPtr;
|
1377 |
{
|
1378 |
int resolution;
|
1379 |
long numcolormap;
|
1380 |
|
1381 |
long width,height,x;
|
1382 |
unsigned char c;
|
1383 |
unsigned int top,left;
|
1384 |
int num;
|
1385 |
|
1386 |
top = 0;
|
1387 |
left = 0;
|
1388 |
|
1389 |
pixelSize=blockPtr->pixelSize;
|
1390 |
greenOffset=blockPtr->offset[1]-blockPtr->offset[0];
|
1391 |
blueOffset=blockPtr->offset[2]-blockPtr->offset[0];
|
1392 |
alphaOffset = blockPtr->offset[0];
|
1393 |
if (alphaOffset < blockPtr->offset[2]) {
|
1394 |
alphaOffset = blockPtr->offset[2];
|
1395 |
}
|
1396 |
if (++alphaOffset < pixelSize) {
|
1397 |
alphaOffset -= blockPtr->offset[0];
|
1398 |
} else {
|
1399 |
alphaOffset = 0;
|
1400 |
}
|
1401 |
|
1402 |
Tcl_Write(handle, (char *) (alphaOffset ? GIF89a : GIF87a), 6);
|
1403 |
|
1404 |
for (x=0;x<MAXCOLORMAPSIZE;x++) {
|
1405 |
mapa[x][CM_RED] = 255;
|
1406 |
mapa[x][CM_GREEN] = 255;
|
1407 |
mapa[x][CM_BLUE] = 255;
|
1408 |
}
|
1409 |
|
1410 |
|
1411 |
width=blockPtr->width;
|
1412 |
height=blockPtr->height;
|
1413 |
pixelo=blockPtr->pixelPtr + blockPtr->offset[0];
|
1414 |
pixelPitch=blockPtr->pitch;
|
1415 |
if ((num=savemap(blockPtr,mapa))<0) {
|
1416 |
Tcl_AppendResult(interp, "too many colors", (char *) NULL);
|
1417 |
return TCL_ERROR;
|
1418 |
}
|
1419 |
if (num<3) num=3;
|
1420 |
c=LSB(width);
|
1421 |
Mputc(c,handle);
|
1422 |
c=MSB(width);
|
1423 |
Mputc(c,handle);
|
1424 |
c=LSB(height);
|
1425 |
Mputc(c,handle);
|
1426 |
c=MSB(height);
|
1427 |
Mputc(c,handle);
|
1428 |
|
1429 |
c= (1 << 7) | (no_bits(num) << 4) | (no_bits(num));
|
1430 |
Mputc(c,handle);
|
1431 |
resolution = no_bits(num)+1;
|
1432 |
|
1433 |
numcolormap=1 << resolution;
|
1434 |
|
1435 |
/* background color */
|
1436 |
|
1437 |
c = 0;
|
1438 |
Mputc(c,handle);
|
1439 |
|
1440 |
/* zero for future expansion */
|
1441 |
|
1442 |
Mputc(c,handle);
|
1443 |
|
1444 |
for (x=0; x<numcolormap ;x++) {
|
1445 |
c = mapa[x][CM_RED];
|
1446 |
Mputc(c,handle);
|
1447 |
c = mapa[x][CM_GREEN];
|
1448 |
Mputc(c,handle);
|
1449 |
c = mapa[x][CM_BLUE];
|
1450 |
Mputc(c,handle);
|
1451 |
}
|
1452 |
|
1453 |
/*
|
1454 |
* Write out extension for transparent colour index, if necessary.
|
1455 |
*/
|
1456 |
|
1457 |
if (alphaOffset) {
|
1458 |
c = GIF_EXTENSION;
|
1459 |
Mputc(c, handle);
|
1460 |
Tcl_Write(handle, "\371\4\1\0\0\0", 7);
|
1461 |
}
|
1462 |
|
1463 |
c = GIF_START;
|
1464 |
Mputc(c,handle);
|
1465 |
c=LSB(top);
|
1466 |
Mputc(c,handle);
|
1467 |
c=MSB(top);
|
1468 |
Mputc(c,handle);
|
1469 |
c=LSB(left);
|
1470 |
Mputc(c,handle);
|
1471 |
c=MSB(left);
|
1472 |
Mputc(c,handle);
|
1473 |
|
1474 |
c=LSB(width);
|
1475 |
Mputc(c,handle);
|
1476 |
c=MSB(width);
|
1477 |
Mputc(c,handle);
|
1478 |
|
1479 |
c=LSB(height);
|
1480 |
Mputc(c,handle);
|
1481 |
c=MSB(height);
|
1482 |
Mputc(c,handle);
|
1483 |
|
1484 |
c=0;
|
1485 |
Mputc(c,handle);
|
1486 |
c=resolution;
|
1487 |
Mputc(c,handle);
|
1488 |
|
1489 |
ssize = rsize = blockPtr->width;
|
1490 |
csize = blockPtr->height;
|
1491 |
compress(resolution+1, handle, ReadValue);
|
1492 |
|
1493 |
c = 0;
|
1494 |
Mputc(c,handle);
|
1495 |
c = GIF_TERMINATOR;
|
1496 |
Mputc(c,handle);
|
1497 |
|
1498 |
return TCL_OK;
|
1499 |
}
|
1500 |
|
1501 |
static int
|
1502 |
color(red, green, blue)
|
1503 |
int red;
|
1504 |
int green;
|
1505 |
int blue;
|
1506 |
{
|
1507 |
int x;
|
1508 |
for (x=(alphaOffset != 0);x<=MAXCOLORMAPSIZE;x++) {
|
1509 |
if ((mapa[x][CM_RED]==red) && (mapa[x][CM_GREEN]==green) &&
|
1510 |
(mapa[x][CM_BLUE]==blue)) {
|
1511 |
return x;
|
1512 |
}
|
1513 |
}
|
1514 |
return -1;
|
1515 |
}
|
1516 |
|
1517 |
|
1518 |
static int
|
1519 |
nuevo(red, green, blue, mapa)
|
1520 |
int red,green,blue;
|
1521 |
unsigned char mapa[MAXCOLORMAPSIZE][3];
|
1522 |
{
|
1523 |
int x;
|
1524 |
for (x=(alphaOffset != 0);x<num;x++) {
|
1525 |
if ((mapa[x][CM_RED]==red) && (mapa[x][CM_GREEN]==green) &&
|
1526 |
(mapa[x][CM_BLUE]==blue)) {
|
1527 |
return 0;
|
1528 |
}
|
1529 |
}
|
1530 |
return 1;
|
1531 |
}
|
1532 |
|
1533 |
static int
|
1534 |
savemap(blockPtr,mapa)
|
1535 |
Tk_PhotoImageBlock *blockPtr;
|
1536 |
unsigned char mapa[MAXCOLORMAPSIZE][3];
|
1537 |
{
|
1538 |
unsigned char *colores;
|
1539 |
int x,y;
|
1540 |
unsigned char red,green,blue;
|
1541 |
|
1542 |
if (alphaOffset) {
|
1543 |
num = 1;
|
1544 |
mapa[0][CM_RED] = 0xd9;
|
1545 |
mapa[0][CM_GREEN] = 0xd9;
|
1546 |
mapa[0][CM_BLUE] = 0xd9;
|
1547 |
} else {
|
1548 |
num = 0;
|
1549 |
}
|
1550 |
|
1551 |
for(y=0;y<blockPtr->height;y++) {
|
1552 |
colores=blockPtr->pixelPtr + blockPtr->offset[0]
|
1553 |
+ y * blockPtr->pitch;
|
1554 |
for(x=0;x<blockPtr->width;x++) {
|
1555 |
if (!alphaOffset || (colores[alphaOffset] != 0)) {
|
1556 |
red = colores[0];
|
1557 |
green = colores[greenOffset];
|
1558 |
blue = colores[blueOffset];
|
1559 |
if (nuevo(red,green,blue,mapa)) {
|
1560 |
if (num>255)
|
1561 |
return -1;
|
1562 |
|
1563 |
mapa[num][CM_RED]=red;
|
1564 |
mapa[num][CM_GREEN]=green;
|
1565 |
mapa[num][CM_BLUE]=blue;
|
1566 |
num++;
|
1567 |
}
|
1568 |
}
|
1569 |
colores += pixelSize;
|
1570 |
}
|
1571 |
}
|
1572 |
return num-1;
|
1573 |
}
|
1574 |
|
1575 |
static int
|
1576 |
ReadValue()
|
1577 |
{
|
1578 |
unsigned int col;
|
1579 |
|
1580 |
if (csize == 0) {
|
1581 |
return EOF;
|
1582 |
}
|
1583 |
if (alphaOffset && (pixelo[alphaOffset]==0)) {
|
1584 |
col = 0;
|
1585 |
} else {
|
1586 |
col = color(pixelo[0],pixelo[greenOffset],pixelo[blueOffset]);
|
1587 |
}
|
1588 |
pixelo += pixelSize;
|
1589 |
if (--ssize <= 0) {
|
1590 |
ssize = rsize;
|
1591 |
csize--;
|
1592 |
pixelo += pixelPitch - (rsize * pixelSize);
|
1593 |
}
|
1594 |
|
1595 |
return col;
|
1596 |
}
|
1597 |
|
1598 |
/*
|
1599 |
* Return the number of bits ( -1 ) to represent a given
|
1600 |
* number of colors ( ex: 256 colors => 7 ).
|
1601 |
*/
|
1602 |
|
1603 |
static int
|
1604 |
no_bits( colors )
|
1605 |
int colors;
|
1606 |
{
|
1607 |
register int bits = 0;
|
1608 |
|
1609 |
colors--;
|
1610 |
while ( colors >> bits ) {
|
1611 |
bits++;
|
1612 |
}
|
1613 |
|
1614 |
return (bits-1);
|
1615 |
}
|
1616 |
|
1617 |
|
1618 |
|
1619 |
/*-----------------------------------------------------------------------
|
1620 |
*
|
1621 |
* miGIF Compression - mouse and ivo's GIF-compatible compression
|
1622 |
*
|
1623 |
* -run length encoding compression routines-
|
1624 |
*
|
1625 |
* Copyright (C) 1998 Hutchison Avenue Software Corporation
|
1626 |
* http://www.hasc.com
|
1627 |
* info@hasc.com
|
1628 |
*
|
1629 |
* Permission to use, copy, modify, and distribute this software and its
|
1630 |
* documentation for any purpose and without fee is hereby granted, provided
|
1631 |
* that the above copyright notice appear in all copies and that both that
|
1632 |
* copyright notice and this permission notice appear in supporting
|
1633 |
* documentation. This software is provided "AS IS." The Hutchison Avenue
|
1634 |
* Software Corporation disclaims all warranties, either express or implied,
|
1635 |
* including but not limited to implied warranties of merchantability and
|
1636 |
* fitness for a particular purpose, with respect to this code and accompanying
|
1637 |
* documentation.
|
1638 |
*
|
1639 |
* The miGIF compression routines do not, strictly speaking, generate files
|
1640 |
* conforming to the GIF spec, since the image data is not LZW-compressed
|
1641 |
* (this is the point: in order to avoid transgression of the Unisys patent
|
1642 |
* on the LZW algorithm.) However, miGIF generates data streams that any
|
1643 |
* reasonably sane LZW decompresser will decompress to what we want.
|
1644 |
*
|
1645 |
* miGIF compression uses run length encoding. It compresses horizontal runs
|
1646 |
* of pixels of the same color. This type of compression gives good results
|
1647 |
* on images with many runs, for example images with lines, text and solid
|
1648 |
* shapes on a solid-colored background. It gives little or no compression
|
1649 |
* on images with few runs, for example digital or scanned photos.
|
1650 |
*
|
1651 |
* der Mouse
|
1652 |
* mouse@rodents.montreal.qc.ca
|
1653 |
* 7D C8 61 52 5D E7 2D 39 4E F1 31 3E E8 B3 27 4B
|
1654 |
*
|
1655 |
* ivo@hasc.com
|
1656 |
*
|
1657 |
* The Graphics Interchange Format(c) is the Copyright property of
|
1658 |
* CompuServe Incorporated. GIF(sm) is a Service Mark property of
|
1659 |
* CompuServe Incorporated.
|
1660 |
*
|
1661 |
*/
|
1662 |
|
1663 |
static int rl_pixel;
|
1664 |
static int rl_basecode;
|
1665 |
static int rl_count;
|
1666 |
static int rl_table_pixel;
|
1667 |
static int rl_table_max;
|
1668 |
static int just_cleared;
|
1669 |
static int out_bits;
|
1670 |
static int out_bits_init;
|
1671 |
static int out_count;
|
1672 |
static int out_bump;
|
1673 |
static int out_bump_init;
|
1674 |
static int out_clear;
|
1675 |
static int out_clear_init;
|
1676 |
static int max_ocodes;
|
1677 |
static int code_clear;
|
1678 |
static int code_eof;
|
1679 |
static unsigned int obuf;
|
1680 |
static int obits;
|
1681 |
static Tcl_Channel ofile;
|
1682 |
static unsigned char oblock[256];
|
1683 |
static int oblen;
|
1684 |
|
1685 |
/* Used only when debugging GIF compression code */
|
1686 |
/* #define DEBUGGING_ENVARS */
|
1687 |
|
1688 |
#ifdef DEBUGGING_ENVARS
|
1689 |
|
1690 |
static int verbose_set = 0;
|
1691 |
static int verbose;
|
1692 |
#define VERBOSE (verbose_set?verbose:set_verbose())
|
1693 |
|
1694 |
static int set_verbose(void)
|
1695 |
{
|
1696 |
verbose = !!getenv("GIF_VERBOSE");
|
1697 |
verbose_set = 1;
|
1698 |
return(verbose);
|
1699 |
}
|
1700 |
|
1701 |
#else
|
1702 |
|
1703 |
#define VERBOSE 0
|
1704 |
|
1705 |
#endif
|
1706 |
|
1707 |
|
1708 |
static CONST char *
|
1709 |
binformat(v, nbits)
|
1710 |
unsigned int v;
|
1711 |
int nbits;
|
1712 |
{
|
1713 |
static char bufs[8][64];
|
1714 |
static int bhand = 0;
|
1715 |
unsigned int bit;
|
1716 |
int bno;
|
1717 |
char *bp;
|
1718 |
|
1719 |
bhand --;
|
1720 |
if (bhand < 0) bhand = (sizeof(bufs)/sizeof(bufs[0]))-1;
|
1721 |
bp = &bufs[bhand][0];
|
1722 |
for (bno=nbits-1,bit=((unsigned int)1)<<bno;bno>=0;bno--,bit>>=1)
|
1723 |
{ *bp++ = (v & bit) ? '1' : '0';
|
1724 |
if (((bno&3) == 0) && (bno != 0)) *bp++ = '.';
|
1725 |
}
|
1726 |
*bp = '\0';
|
1727 |
return(&bufs[bhand][0]);
|
1728 |
}
|
1729 |
|
1730 |
static void write_block()
|
1731 |
{
|
1732 |
int i;
|
1733 |
unsigned char c;
|
1734 |
|
1735 |
if (VERBOSE)
|
1736 |
{ printf("write_block %d:",oblen);
|
1737 |
for (i=0;i<oblen;i++) printf(" %02x",oblock[i]);
|
1738 |
printf("\n");
|
1739 |
}
|
1740 |
c = oblen;
|
1741 |
Tcl_Write(ofile, (char *) &c, 1);
|
1742 |
Tcl_Write(ofile, (char *) &oblock[0], oblen);
|
1743 |
oblen = 0;
|
1744 |
}
|
1745 |
|
1746 |
static void
|
1747 |
block_out(c)
|
1748 |
unsigned char c;
|
1749 |
{
|
1750 |
if (VERBOSE) printf("block_out %s\n",binformat(c,8));
|
1751 |
oblock[oblen++] = c;
|
1752 |
if (oblen >= 255) write_block();
|
1753 |
}
|
1754 |
|
1755 |
static void block_flush()
|
1756 |
{
|
1757 |
if (VERBOSE) printf("block_flush\n");
|
1758 |
if (oblen > 0) write_block();
|
1759 |
}
|
1760 |
|
1761 |
static void output(val)
|
1762 |
int val;
|
1763 |
{
|
1764 |
if (VERBOSE) printf("output %s [%s %d %d]\n",binformat(val,out_bits),binformat(obuf,obits),obits,out_bits);
|
1765 |
obuf |= val << obits;
|
1766 |
obits += out_bits;
|
1767 |
while (obits >= 8)
|
1768 |
{ block_out(obuf&0xff);
|
1769 |
obuf >>= 8;
|
1770 |
obits -= 8;
|
1771 |
}
|
1772 |
if (VERBOSE) printf("output leaving [%s %d]\n",binformat(obuf,obits),obits);
|
1773 |
}
|
1774 |
|
1775 |
static void output_flush()
|
1776 |
{
|
1777 |
if (VERBOSE) printf("output_flush\n");
|
1778 |
if (obits > 0) block_out(obuf);
|
1779 |
block_flush();
|
1780 |
}
|
1781 |
|
1782 |
static void did_clear()
|
1783 |
{
|
1784 |
if (VERBOSE) printf("did_clear\n");
|
1785 |
out_bits = out_bits_init;
|
1786 |
out_bump = out_bump_init;
|
1787 |
out_clear = out_clear_init;
|
1788 |
out_count = 0;
|
1789 |
rl_table_max = 0;
|
1790 |
just_cleared = 1;
|
1791 |
}
|
1792 |
|
1793 |
static void
|
1794 |
output_plain(c)
|
1795 |
int c;
|
1796 |
{
|
1797 |
if (VERBOSE) printf("output_plain %s\n",binformat(c,out_bits));
|
1798 |
just_cleared = 0;
|
1799 |
output(c);
|
1800 |
out_count ++;
|
1801 |
if (out_count >= out_bump)
|
1802 |
{ out_bits ++;
|
1803 |
out_bump += 1 << (out_bits - 1);
|
1804 |
}
|
1805 |
if (out_count >= out_clear)
|
1806 |
{ output(code_clear);
|
1807 |
did_clear();
|
1808 |
}
|
1809 |
}
|
1810 |
|
1811 |
static unsigned int isqrt(x)
|
1812 |
unsigned int x;
|
1813 |
{
|
1814 |
unsigned int r;
|
1815 |
unsigned int v;
|
1816 |
|
1817 |
if (x < 2) return(x);
|
1818 |
for (v=x,r=1;v;v>>=2,r<<=1) ;
|
1819 |
while (1)
|
1820 |
{ v = ((x / r) + r) / 2;
|
1821 |
if ((v == r) || (v == r+1)) return(r);
|
1822 |
r = v;
|
1823 |
}
|
1824 |
}
|
1825 |
|
1826 |
static unsigned int
|
1827 |
compute_triangle_count(count, nrepcodes)
|
1828 |
unsigned int count;
|
1829 |
unsigned int nrepcodes;
|
1830 |
{
|
1831 |
unsigned int perrep;
|
1832 |
unsigned int cost;
|
1833 |
|
1834 |
cost = 0;
|
1835 |
perrep = (nrepcodes * (nrepcodes+1)) / 2;
|
1836 |
while (count >= perrep)
|
1837 |
{ cost += nrepcodes;
|
1838 |
count -= perrep;
|
1839 |
}
|
1840 |
if (count > 0)
|
1841 |
{ unsigned int n;
|
1842 |
n = isqrt(count);
|
1843 |
while ((n*(n+1)) >= 2*count) n --;
|
1844 |
while ((n*(n+1)) < 2*count) n ++;
|
1845 |
cost += n;
|
1846 |
}
|
1847 |
return(cost);
|
1848 |
}
|
1849 |
|
1850 |
static void max_out_clear()
|
1851 |
{
|
1852 |
out_clear = max_ocodes;
|
1853 |
}
|
1854 |
|
1855 |
static void reset_out_clear()
|
1856 |
{
|
1857 |
out_clear = out_clear_init;
|
1858 |
if (out_count >= out_clear)
|
1859 |
{ output(code_clear);
|
1860 |
did_clear();
|
1861 |
}
|
1862 |
}
|
1863 |
|
1864 |
static void
|
1865 |
rl_flush_fromclear(count)
|
1866 |
int count;
|
1867 |
{
|
1868 |
int n;
|
1869 |
|
1870 |
if (VERBOSE) printf("rl_flush_fromclear %d\n",count);
|
1871 |
max_out_clear();
|
1872 |
rl_table_pixel = rl_pixel;
|
1873 |
n = 1;
|
1874 |
while (count > 0)
|
1875 |
{ if (n == 1)
|
1876 |
{ rl_table_max = 1;
|
1877 |
output_plain(rl_pixel);
|
1878 |
count --;
|
1879 |
}
|
1880 |
else if (count >= n)
|
1881 |
{ rl_table_max = n;
|
1882 |
output_plain(rl_basecode+n-2);
|
1883 |
count -= n;
|
1884 |
}
|
1885 |
else if (count == 1)
|
1886 |
{ rl_table_max ++;
|
1887 |
output_plain(rl_pixel);
|
1888 |
count = 0;
|
1889 |
}
|
1890 |
else
|
1891 |
{ rl_table_max ++;
|
1892 |
output_plain(rl_basecode+count-2);
|
1893 |
count = 0;
|
1894 |
}
|
1895 |
if (out_count == 0) n = 1; else n ++;
|
1896 |
}
|
1897 |
reset_out_clear();
|
1898 |
if (VERBOSE) printf("rl_flush_fromclear leaving table_max=%d\n",rl_table_max);
|
1899 |
}
|
1900 |
|
1901 |
static void rl_flush_clearorrep(count)
|
1902 |
int count;
|
1903 |
{
|
1904 |
int withclr;
|
1905 |
|
1906 |
if (VERBOSE) printf("rl_flush_clearorrep %d\n",count);
|
1907 |
withclr = 1 + compute_triangle_count(count,max_ocodes);
|
1908 |
if (withclr < count)
|
1909 |
{ output(code_clear);
|
1910 |
did_clear();
|
1911 |
rl_flush_fromclear(count);
|
1912 |
}
|
1913 |
else
|
1914 |
{ for (;count>0;count--) output_plain(rl_pixel);
|
1915 |
}
|
1916 |
}
|
1917 |
|
1918 |
static void rl_flush_withtable(count)
|
1919 |
int count;
|
1920 |
{
|
1921 |
int repmax;
|
1922 |
int repleft;
|
1923 |
int leftover;
|
1924 |
|
1925 |
if (VERBOSE) printf("rl_flush_withtable %d\n",count);
|
1926 |
repmax = count / rl_table_max;
|
1927 |
leftover = count % rl_table_max;
|
1928 |
repleft = (leftover ? 1 : 0);
|
1929 |
if (out_count+repmax+repleft > max_ocodes)
|
1930 |
{ repmax = max_ocodes - out_count;
|
1931 |
leftover = count - (repmax * rl_table_max);
|
1932 |
repleft = 1 + compute_triangle_count(leftover,max_ocodes);
|
1933 |
}
|
1934 |
if (VERBOSE) printf("rl_flush_withtable repmax=%d leftover=%d repleft=%d\n",repmax,leftover,repleft);
|
1935 |
if (1+(int)compute_triangle_count(count,max_ocodes) < repmax+repleft)
|
1936 |
{ output(code_clear);
|
1937 |
did_clear();
|
1938 |
rl_flush_fromclear(count);
|
1939 |
return;
|
1940 |
}
|
1941 |
max_out_clear();
|
1942 |
for (;repmax>0;repmax--) output_plain(rl_basecode+rl_table_max-2);
|
1943 |
if (leftover)
|
1944 |
{ if (just_cleared)
|
1945 |
{ rl_flush_fromclear(leftover);
|
1946 |
}
|
1947 |
else if (leftover == 1)
|
1948 |
{ output_plain(rl_pixel);
|
1949 |
}
|
1950 |
else
|
1951 |
{ output_plain(rl_basecode+leftover-2);
|
1952 |
}
|
1953 |
}
|
1954 |
reset_out_clear();
|
1955 |
}
|
1956 |
|
1957 |
static void rl_flush()
|
1958 |
{
|
1959 |
if (VERBOSE) printf("rl_flush [ %d %d\n",rl_count,rl_pixel);
|
1960 |
if (rl_count == 1)
|
1961 |
{ output_plain(rl_pixel);
|
1962 |
rl_count = 0;
|
1963 |
if (VERBOSE) printf("rl_flush ]\n");
|
1964 |
return;
|
1965 |
}
|
1966 |
if (just_cleared)
|
1967 |
{ rl_flush_fromclear(rl_count);
|
1968 |
}
|
1969 |
else if ((rl_table_max < 2) || (rl_table_pixel != rl_pixel))
|
1970 |
{ rl_flush_clearorrep(rl_count);
|
1971 |
}
|
1972 |
else
|
1973 |
{ rl_flush_withtable(rl_count);
|
1974 |
}
|
1975 |
if (VERBOSE) printf("rl_flush ]\n");
|
1976 |
rl_count = 0;
|
1977 |
}
|
1978 |
|
1979 |
|
1980 |
static void compress( init_bits, handle, readValue )
|
1981 |
int init_bits;
|
1982 |
Tcl_Channel handle;
|
1983 |
ifunptr readValue;
|
1984 |
{
|
1985 |
int c;
|
1986 |
|
1987 |
ofile = handle;
|
1988 |
obuf = 0;
|
1989 |
obits = 0;
|
1990 |
oblen = 0;
|
1991 |
code_clear = 1 << (init_bits - 1);
|
1992 |
code_eof = code_clear + 1;
|
1993 |
rl_basecode = code_eof + 1;
|
1994 |
out_bump_init = (1 << (init_bits - 1)) - 1;
|
1995 |
/* for images with a lot of runs, making out_clear_init larger will
|
1996 |
give better compression. */
|
1997 |
out_clear_init = (init_bits <= 3) ? 9 : (out_bump_init-1);
|
1998 |
#ifdef DEBUGGING_ENVARS
|
1999 |
{ const char *ocienv;
|
2000 |
ocienv = getenv("GIF_OUT_CLEAR_INIT");
|
2001 |
if (ocienv)
|
2002 |
{ out_clear_init = atoi(ocienv);
|
2003 |
if (VERBOSE) printf("[overriding out_clear_init to %d]\n",out_clear_init);
|
2004 |
}
|
2005 |
}
|
2006 |
#endif
|
2007 |
out_bits_init = init_bits;
|
2008 |
max_ocodes = (1 << GIFBITS) - ((1 << (out_bits_init - 1)) + 3);
|
2009 |
did_clear();
|
2010 |
output(code_clear);
|
2011 |
rl_count = 0;
|
2012 |
while (1)
|
2013 |
{ c = readValue();
|
2014 |
if ((rl_count > 0) && (c != rl_pixel)) rl_flush();
|
2015 |
if (c == EOF) break;
|
2016 |
if (rl_pixel == c)
|
2017 |
{ rl_count ++;
|
2018 |
}
|
2019 |
else
|
2020 |
{ rl_pixel = c;
|
2021 |
rl_count = 1;
|
2022 |
}
|
2023 |
}
|
2024 |
output(code_eof);
|
2025 |
output_flush();
|
2026 |
}
|
2027 |
|
2028 |
/*-----------------------------------------------------------------------
|
2029 |
*
|
2030 |
* End of miGIF section - See copyright notice at start of section.
|
2031 |
*
|
2032 |
*-----------------------------------------------------------------------*/
|
2033 |
|
2034 |
/* End of tkimggif.c */
|