5 |
|
* Windows and OS/2 BMP file support |
6 |
|
*/ |
7 |
|
|
8 |
– |
/* XXX reading and writing of compressed files currently unsupported */ |
9 |
– |
|
8 |
|
#include <stdio.h> |
9 |
|
#include <stdlib.h> |
10 |
|
#include <string.h> |
23 |
|
return "Truncated BMP image"; |
24 |
|
case BIR_UNSUPPORTED: |
25 |
|
return "Unsupported BMP feature"; |
26 |
+ |
case BIR_RLERROR: |
27 |
+ |
return "BMP runlength encoding error"; |
28 |
|
case BIR_SEEKERR: |
29 |
|
return "BMP seek error"; |
30 |
|
} |
31 |
|
return "Unknown BMP error"; |
32 |
|
} |
33 |
|
|
34 |
< |
/* compute uncompressed scanline size */ |
35 |
< |
static uint32 |
36 |
< |
getScanSiz(BMPHeader *hdr) |
34 |
> |
/* check than header is sensible */ |
35 |
> |
static int |
36 |
> |
BMPheaderOK(const BMPHeader *hdr) |
37 |
|
{ |
38 |
< |
uint32 scanSiz; |
39 |
< |
/* bytes per scanline */ |
40 |
< |
scanSiz = (hdr->bpp*hdr->width + 7) >> 3; |
41 |
< |
if (scanSiz & 3) /* 32-bit word boundary */ |
42 |
< |
scanSiz += 4 - (scanSiz & 3); |
43 |
< |
|
44 |
< |
return scanSiz; |
38 |
> |
if (!hdr) |
39 |
> |
return 0; |
40 |
> |
if ((hdr->width <= 0) | (hdr->height <= 0)) |
41 |
> |
return 0; |
42 |
> |
switch (hdr->bpp) { /* check compression */ |
43 |
> |
case 1: |
44 |
> |
case 24: |
45 |
> |
if (hdr->compr != BI_UNCOMPR) |
46 |
> |
return 0; |
47 |
> |
break; |
48 |
> |
case 16: |
49 |
> |
case 32: |
50 |
> |
if ((hdr->compr != BI_UNCOMPR) & (hdr->compr != BI_BITFIELDS)) |
51 |
> |
return 0; |
52 |
> |
break; |
53 |
> |
case 4: |
54 |
> |
if ((hdr->compr != BI_UNCOMPR) & (hdr->compr != BI_RLE4)) |
55 |
> |
return 0; |
56 |
> |
break; |
57 |
> |
case 8: |
58 |
> |
if ((hdr->compr != BI_UNCOMPR) & (hdr->compr != BI_RLE8)) |
59 |
> |
return 0; |
60 |
> |
break; |
61 |
> |
default: |
62 |
> |
return 0; |
63 |
> |
} |
64 |
> |
if (hdr->compr == BI_BITFIELDS && (BMPbitField(hdr)[0] & |
65 |
> |
BMPbitField(hdr)[1] & BMPbitField(hdr)[2])) |
66 |
> |
return 0; |
67 |
> |
if ((hdr->nColors < 0) | (hdr->impColors < 0)) |
68 |
> |
return 0; |
69 |
> |
if (hdr->impColors > hdr->nColors) |
70 |
> |
return 0; |
71 |
> |
if (hdr->nColors > BMPpalLen(hdr)) |
72 |
> |
return 0; |
73 |
> |
return 1; |
74 |
|
} |
75 |
|
|
76 |
+ |
/* compute uncompressed scan size */ |
77 |
+ |
#define getScanSiz(h) ( ((((h)->bpp*(h)->width+7) >>3) + 3) & ~03 ) |
78 |
+ |
|
79 |
|
/* get next byte from reader */ |
80 |
|
#define rdbyte(c,br) ((br)->fpos += (c=(*(br)->cget)((br)->c_data))!=EOF, c) |
81 |
|
|
162 |
|
(void)rdint32(br); /* file size */ |
163 |
|
(void)rdint32(br); /* reserved word */ |
164 |
|
bmPos = rdint32(br); /* offset to bitmap */ |
165 |
< |
hdrSiz = rdint32(br) + 14; /* header size */ |
165 |
> |
hdrSiz = 2 + 3*4 + rdint32(br); /* header size */ |
166 |
|
if (hdrSiz < 2 + 6*4 + 2*2 + 6*4) |
167 |
|
goto err; |
168 |
|
br->hdr->width = rdint32(br); /* bitmap width */ |
174 |
|
if (rduint16(br) != 1) /* number of planes */ |
175 |
|
goto err; |
176 |
|
br->hdr->bpp = rduint16(br); /* bits per pixel */ |
145 |
– |
if (br->hdr->bpp != 1 && br->hdr->bpp != 4 && |
146 |
– |
br->hdr->bpp != 8 && br->hdr->bpp != 24 && |
147 |
– |
br->hdr->bpp != 32) |
148 |
– |
goto err; |
177 |
|
br->hdr->compr = rdint32(br); /* compression mode */ |
150 |
– |
if (br->hdr->compr != BI_UNCOMPR && br->hdr->compr != BI_RLE8) |
151 |
– |
goto err; /* don't support the rest */ |
178 |
|
(void)rdint32(br); /* bitmap size */ |
179 |
|
br->hdr->hRes = rdint32(br); /* horizontal resolution */ |
180 |
|
br->hdr->vRes = rdint32(br); /* vertical resolution */ |
182 |
|
br->hdr->impColors = rdint32(br); /* # important colors */ |
183 |
|
if (br->hdr->impColors < 0) |
184 |
|
goto err; /* catch premature EOF */ |
185 |
< |
palLen = 0; |
186 |
< |
if (br->hdr->bpp <= 8) { |
187 |
< |
palLen = 1 << br->hdr->bpp; |
185 |
> |
if (!BMPheaderOK(br->hdr)) |
186 |
> |
goto err; |
187 |
> |
palLen = BMPpalLen(br->hdr); |
188 |
> |
if (br->hdr->bpp <= 8) { /* normalize color counts */ |
189 |
|
if (br->hdr->nColors <= 0) |
190 |
|
br->hdr->nColors = palLen; |
164 |
– |
else if (br->hdr->nColors > palLen) |
165 |
– |
goto err; |
191 |
|
if (br->hdr->impColors <= 0) |
192 |
|
br->hdr->impColors = br->hdr->nColors; |
193 |
< |
else if (br->hdr->impColors > br->hdr->nColors) |
169 |
< |
goto err; |
170 |
< |
} else if (br->hdr->nColors > 0 || br->hdr->compr != BI_UNCOMPR) |
171 |
< |
goto err; |
193 |
> |
} |
194 |
|
/* extend header */ |
195 |
|
if (bmPos < hdrSiz + sizeof(RGBquad)*palLen) |
196 |
|
goto err; |
198 |
|
if (palLen > 0 || br->hdr->infoSiz > 0) { |
199 |
|
br->hdr = (BMPHeader *)realloc((void *)br->hdr, |
200 |
|
sizeof(BMPHeader) + |
201 |
< |
sizeof(RGBquad)*palLen - |
180 |
< |
sizeof(br->hdr->palette) + |
201 |
> |
sizeof(RGBquad)*palLen + |
202 |
|
br->hdr->infoSiz); |
203 |
|
if (br->hdr == NULL) |
204 |
|
goto err; |
205 |
|
} |
206 |
< |
/* read color palette */ |
207 |
< |
if (rdbytes((char *)br->hdr->palette, |
206 |
> |
/* read colors or fields */ |
207 |
> |
if (br->hdr->compr == BI_BITFIELDS) { |
208 |
> |
BMPbitField(br->hdr)[0] = (uint32)rdint32(br); |
209 |
> |
BMPbitField(br->hdr)[1] = (uint32)rdint32(br); |
210 |
> |
BMPbitField(br->hdr)[2] = (uint32)rdint32(br); |
211 |
> |
} else if (rdbytes((char *)br->hdr->palette, |
212 |
|
sizeof(RGBquad)*palLen, br) != BIR_OK) |
213 |
|
goto err; |
214 |
|
/* read add'l information */ |
219 |
|
if (br->scanline == NULL) |
220 |
|
goto err; |
221 |
|
br->yscan = -1; |
222 |
< |
if (seek != NULL && br->hdr->compr != BI_UNCOMPR) { |
222 |
> |
if (seek != NULL && ((br->hdr->compr == BI_RLE8) | |
223 |
> |
(br->hdr->compr == BI_RLE4))) { |
224 |
|
BMPReader *newbr = (BMPReader *)realloc((void *)br, |
225 |
|
sizeof(BMPReader) + |
226 |
|
sizeof(br->scanpos[0]) * |
255 |
|
return -1; |
256 |
|
if (hdr->bpp > 8) /* assume they had a reason for it */ |
257 |
|
return 0; |
258 |
< |
for (rgbp = hdr->palette, n = hdr->impColors; n-- > 0; rgbp++) |
258 |
> |
for (rgbp = hdr->palette, n = hdr->nColors; n-- > 0; rgbp++) |
259 |
|
if (((rgbp->r != rgbp->g) | (rgbp->g != rgbp->b))) |
260 |
|
return 0; |
261 |
|
return 1; /* all colors neutral in map */ |
265 |
|
int |
266 |
|
BMPreadScanline(BMPReader *br) |
267 |
|
{ |
268 |
+ |
int n; |
269 |
+ |
int8 *sp; |
270 |
+ |
|
271 |
|
if (br->yscan + 1 >= br->hdr->height) |
272 |
|
return BIR_EOF; |
273 |
|
br->yscan++; /* prepare to read */ |
274 |
< |
if (br->hdr->compr == BI_UNCOMPR) |
275 |
< |
return rdbytes((char *)br->scanline, getScanSiz(br->hdr), br); |
276 |
< |
/* XXX need to perform actual decompression */ |
277 |
< |
return BIR_UNSUPPORTED; |
278 |
< |
if (br->seek != NULL) |
274 |
> |
n = getScanSiz(br->hdr); /* reading uncompressed data? */ |
275 |
> |
if (br->hdr->compr == BI_UNCOMPR || br->hdr->compr == BI_BITFIELDS) |
276 |
> |
return rdbytes((char *)br->scanline, n, br); |
277 |
> |
/* |
278 |
> |
* RLE/RLE8 Decoding |
279 |
> |
* |
280 |
> |
* Certain aspects of this scheme are completely insane, so |
281 |
> |
* we don't support them. Fortunately, they rarely appear. |
282 |
> |
* One is the mid-file EOD (0x0001) and another is the ill-conceived |
283 |
> |
* "delta" (0x0002), which is like a "goto" statement for bitmaps. |
284 |
> |
* Whoever thought this up should be shot, then told why |
285 |
> |
* it's impossible to support such a scheme in any reasonable way. |
286 |
> |
* Also, RLE4 mode allows runs to stop halfway through a byte, |
287 |
> |
* which is likewise uncodeable, so we don't even try. |
288 |
> |
* Finally, the scanline break is ambiguous -- we assume here that |
289 |
> |
* it is required at the end of each scanline, though I haven't |
290 |
> |
* found anywhere this is written. Otherwise, we would read to |
291 |
> |
* the end of the scanline, assuming the next bit of data belongs |
292 |
> |
* the following scan. If a break follows the last pixel, as it |
293 |
> |
* seems to in the files I've tested out of Photoshop, you end up |
294 |
> |
* painting every other line black. Also, I assume any skipped |
295 |
> |
* pixels are painted with color 0, which is often black. Nowhere |
296 |
> |
* is it specified what we should assume for missing pixels. This |
297 |
> |
* is undoubtedly the most brain-dead format I've ever encountered. |
298 |
> |
*/ |
299 |
> |
sp = br->scanline; |
300 |
> |
while (n > 0) { |
301 |
> |
int skipOdd, len, val; |
302 |
> |
|
303 |
> |
if (rdbyte(len, br) == EOF) |
304 |
> |
return BIR_TRUNCATED; |
305 |
> |
if (len > 0) { /* got a run */ |
306 |
> |
if (br->hdr->compr == BI_RLE4) { |
307 |
> |
if (len & 1) |
308 |
> |
return BIR_UNSUPPORTED; |
309 |
> |
len >>= 1; |
310 |
> |
} |
311 |
> |
if (len > n) |
312 |
> |
return BIR_RLERROR; |
313 |
> |
if (rdbyte(val, br) == EOF) |
314 |
> |
return BIR_TRUNCATED; |
315 |
> |
n -= len; |
316 |
> |
while (len--) |
317 |
> |
*sp++ = val; |
318 |
> |
continue; |
319 |
> |
} |
320 |
> |
switch (rdbyte(len, br)) { |
321 |
> |
case EOF: |
322 |
> |
return BIR_TRUNCATED; |
323 |
> |
case 0: /* end of line */ |
324 |
> |
while (n--) |
325 |
> |
*sp++ = 0; |
326 |
> |
/* leaves n == -1 as flag for test after loop */ |
327 |
> |
continue; |
328 |
> |
case 1: /* end of bitmap */ |
329 |
> |
case 2: /* delta */ |
330 |
> |
return BIR_UNSUPPORTED; |
331 |
> |
} |
332 |
> |
/* absolute mode */ |
333 |
> |
if (br->hdr->compr == BI_RLE4) { |
334 |
> |
if (len & 1) |
335 |
> |
return BIR_UNSUPPORTED; |
336 |
> |
len >>= 1; |
337 |
> |
} |
338 |
> |
skipOdd = len & 1; |
339 |
> |
if (len > n) |
340 |
> |
return BIR_RLERROR; |
341 |
> |
n -= len; |
342 |
> |
while (len--) { |
343 |
> |
if (rdbyte(val, br) == EOF) |
344 |
> |
return BIR_TRUNCATED; |
345 |
> |
*sp++ = val; |
346 |
> |
} |
347 |
> |
if (skipOdd && rdbyte(val, br) == EOF) |
348 |
> |
return BIR_TRUNCATED; |
349 |
> |
} |
350 |
> |
/* verify break at end of line */ |
351 |
> |
if (!n && (rdbyte(n, br) != 0 || (rdbyte(n, br) != 0 && |
352 |
> |
(n != 1 || br->yscan != br->hdr->height-1)))) |
353 |
> |
return BIR_RLERROR; |
354 |
> |
if (br->seek != NULL) /* record next scanline position */ |
355 |
|
br->scanpos[br->yscan + 1] = br->fpos; |
356 |
|
return BIR_OK; |
357 |
|
} |
375 |
|
if (y != br->yscan + 1 && br->seek != NULL) { |
376 |
|
int yseek; |
377 |
|
uint32 seekp; |
378 |
< |
if (br->hdr->compr == BI_UNCOMPR) { |
378 |
> |
if (br->hdr->compr == BI_UNCOMPR || |
379 |
> |
br->hdr->compr == BI_BITFIELDS) { |
380 |
|
yseek = y; |
381 |
|
seekp = br->scanpos[0] + y*getScanSiz(br->hdr); |
382 |
|
} else { |
401 |
|
|
402 |
|
/* get ith pixel from last scanline */ |
403 |
|
RGBquad |
404 |
< |
BMPdecodePixel(int i, BMPReader *br) |
404 |
> |
BMPdecodePixel(int i, const BMPReader *br) |
405 |
|
{ |
406 |
+ |
static const uint32 std16mask[3] = {0x7c00, 0x3e0, 0x1f}; |
407 |
|
static const RGBquad black = {0, 0, 0, 0}; |
408 |
+ |
const uint32 *mask; |
409 |
+ |
const uint8 *pp; |
410 |
+ |
uint32 pval, v; |
411 |
+ |
RGBquad cval; |
412 |
|
|
413 |
|
if (((br == NULL) | (i < 0)) || i >= br->hdr->width) |
414 |
|
return black; |
415 |
|
|
416 |
+ |
cval.padding = 0; |
417 |
+ |
|
418 |
|
switch (br->hdr->bpp) { |
419 |
< |
case 24: { |
420 |
< |
uint8 *bgr = br->scanline + 3*i; |
421 |
< |
RGBquad cval; |
422 |
< |
cval.b = bgr[0]; cval.g = bgr[1]; cval.r = bgr[2]; |
423 |
< |
cval.padding = 0; |
419 |
> |
case 24: |
420 |
> |
pp = br->scanline + 3*i; |
421 |
> |
cval.b = *pp++; |
422 |
> |
cval.g = *pp++; |
423 |
> |
cval.r = *pp; |
424 |
|
return cval; |
312 |
– |
} |
425 |
|
case 32: |
426 |
< |
return ((RGBquad *)br->scanline)[i]; |
426 |
> |
if (br->hdr->compr == BI_UNCOMPR) |
427 |
> |
return ((RGBquad *)br->scanline)[i]; |
428 |
> |
/* convert bit fields */ |
429 |
> |
pp = br->scanline + 4*i; |
430 |
> |
pval = *pp++; |
431 |
> |
pval |= *pp++ << 8; |
432 |
> |
pval |= *pp++ << 16; |
433 |
> |
pval |= *pp << 24; |
434 |
> |
mask = BMPbitField(br->hdr); |
435 |
> |
v = pval & mask[0]; |
436 |
> |
while (v & ~0xff) v >>= 8; |
437 |
> |
cval.r = v; |
438 |
> |
v = pval & mask[1]; |
439 |
> |
while (v & ~0xff) v >>= 8; |
440 |
> |
cval.g = v; |
441 |
> |
v = pval & mask[2]; |
442 |
> |
while (v & ~0xff) v >>= 8; |
443 |
> |
cval.b = v; |
444 |
> |
return cval; |
445 |
|
case 8: |
446 |
|
return br->hdr->palette[br->scanline[i]]; |
447 |
|
case 1: |
448 |
< |
return br->hdr->palette[br->scanline[i>>3]>>(i&7) & 1]; |
448 |
> |
return br->hdr->palette[br->scanline[i>>3]>>((7-i)&7) & 1]; |
449 |
|
case 4: |
450 |
< |
return br->hdr->palette[br->scanline[i>>1]>>((i&1)<<2) & 0xf]; |
450 |
> |
return br->hdr->palette[br->scanline[i>>1]>>(i&1?4:0) & 0xf]; |
451 |
> |
case 16: |
452 |
> |
pp = br->scanline + 2*i; |
453 |
> |
pval = *pp++; |
454 |
> |
pval |= *pp++ << 8; |
455 |
> |
mask = std16mask; |
456 |
> |
if (br->hdr->compr == BI_BITFIELDS) |
457 |
> |
mask = BMPbitField(br->hdr); |
458 |
> |
cval.r = ((pval & mask[0]) << 8) / (mask[0] + 1); |
459 |
> |
cval.g = ((pval & mask[1]) << 8) / (mask[1] + 1); |
460 |
> |
cval.b = ((pval & mask[2]) << 8) / (mask[2] + 1); |
461 |
> |
return cval; |
462 |
|
} |
463 |
|
return black; /* should never happen */ |
464 |
|
} |
550 |
|
hdr->height = yr; |
551 |
|
hdr->yIsDown = 0; /* default to upwards order */ |
552 |
|
hdr->bpp = n; |
553 |
< |
hdr->compr = BI_UNCOMPR; |
553 |
> |
hdr->compr = BI_UNCOMPR; /* compression needs seek */ |
554 |
|
hdr->hRes = hdr->vRes = 2835; /* default to 72 ppi */ |
555 |
|
hdr->nColors = ncolors; |
556 |
|
hdr->impColors = 0; /* says all colors important */ |
564 |
|
|
565 |
|
/* put byte to writer */ |
566 |
|
#define wrbyte(c,bw) ( (*(bw)->cput)(c,(bw)->c_data), \ |
567 |
< |
++((bw)->fpos) > (bw)->flen ? \ |
567 |
> |
++(bw)->fpos > (bw)->flen ? \ |
568 |
|
((bw)->flen = (bw)->fpos) : \ |
569 |
|
(bw)->fpos ) |
570 |
|
|
583 |
|
wrbyte(i& 0xff, bw); |
584 |
|
wrbyte(i>>8 & 0xff, bw); |
585 |
|
wrbyte(i>>16 & 0xff, bw); |
586 |
< |
wrbyte(i>>24 & 0xff, bw); |
586 |
> |
wrbyte(i>>24 & 0xff, bw); |
587 |
|
} |
588 |
|
|
589 |
|
/* write 16-bit unsigned integer in littlendian order */ |
623 |
|
BMPWriter *bw; |
624 |
|
uint32 hdrSiz, palSiz, scanSiz, bmSiz; |
625 |
|
/* check arguments */ |
626 |
< |
if (cput == NULL || hdr == NULL) |
626 |
> |
if (cput == NULL) |
627 |
|
return NULL; |
628 |
< |
if (hdr->width <= 0 || hdr->height <= 0) |
628 |
> |
if (!BMPheaderOK(hdr)) |
629 |
|
return NULL; |
630 |
< |
if (hdr->compr != BI_UNCOMPR && hdr->compr != BI_RLE8) |
630 |
> |
if ((hdr->bpp == 16) | (hdr->compr == BI_RLE4)) |
631 |
|
return NULL; /* unsupported */ |
632 |
< |
if (hdr->bpp > 8 && hdr->compr != BI_UNCOMPR) |
632 |
> |
/* no seek means we may have the wrong file length, but most app's don't care |
633 |
> |
if (seek == NULL && ((hdr->compr == BI_RLE8) | (hdr->compr == BI_RLE4))) |
634 |
|
return NULL; |
635 |
< |
palSiz = BMPpalLen(hdr); |
494 |
< |
if (hdr->nColors > palSiz) |
495 |
< |
return NULL; |
496 |
< |
if (hdr->compr != BI_UNCOMPR && seek == NULL) |
497 |
< |
return NULL; |
635 |
> |
*/ |
636 |
|
/* compute sizes */ |
637 |
|
hdrSiz = 2 + 6*4 + 2*2 + 6*4; |
638 |
< |
palSiz *= sizeof(RGBquad); |
638 |
> |
if (hdr->compr == BI_BITFIELDS) |
639 |
> |
hdrSiz += sizeof(uint32)*3; |
640 |
> |
palSiz = sizeof(RGBquad)*BMPpalLen(hdr); |
641 |
|
scanSiz = getScanSiz(hdr); |
642 |
|
bmSiz = hdr->height*scanSiz; /* wrong if compressed */ |
643 |
|
/* initialize writer */ |
687 |
|
#endif |
688 |
|
return bw; |
689 |
|
} |
690 |
+ |
|
691 |
+ |
/* find position of next run of 5 or more identical bytes, or 255 if none */ |
692 |
+ |
static int |
693 |
+ |
findNextRun(const int8 *bp, int len) |
694 |
+ |
{ |
695 |
+ |
int pos, cnt; |
696 |
+ |
/* look for run */ |
697 |
+ |
for (pos = 0; (len > 0) & (pos < 255); pos++, bp++, len--) { |
698 |
+ |
if (len < 5) /* no hope left? */ |
699 |
+ |
continue; |
700 |
+ |
cnt = 1; /* else let's try it */ |
701 |
+ |
while (bp[cnt] == bp[0]) |
702 |
+ |
if (++cnt >= 5) |
703 |
+ |
return pos; /* long enough */ |
704 |
+ |
} |
705 |
+ |
return pos; /* didn't find any */ |
706 |
+ |
} |
707 |
|
|
708 |
|
/* write the current scanline */ |
709 |
|
int |
710 |
|
BMPwriteScanline(BMPWriter *bw) |
711 |
|
{ |
712 |
+ |
const int8 *sp; |
713 |
+ |
int n; |
714 |
+ |
|
715 |
|
if (bw->yscan >= bw->hdr->height) |
716 |
|
return BIR_EOF; |
717 |
|
/* writing uncompressed? */ |
718 |
< |
if (bw->hdr->compr == BI_UNCOMPR) { |
718 |
> |
if (bw->hdr->compr == BI_UNCOMPR || bw->hdr->compr == BI_BITFIELDS) { |
719 |
|
uint32 scanSiz = getScanSiz(bw->hdr); |
720 |
|
uint32 slpos = bw->fbmp + bw->yscan*scanSiz; |
721 |
|
if (wrseek(slpos, bw) != BIR_OK) |
724 |
|
bw->yscan++; |
725 |
|
return BIR_OK; |
726 |
|
} |
727 |
< |
/* else write compressed */ |
728 |
< |
/* XXX need to do actual compression */ |
729 |
< |
return BIR_UNSUPPORTED; |
730 |
< |
/* write file length at end */ |
727 |
> |
/* |
728 |
> |
* RLE8 Encoding |
729 |
> |
* |
730 |
> |
* See the notes in BMPreadScanline() on this encoding. Needless |
731 |
> |
* to say, we avoid the nuttier aspects of this specification. |
732 |
> |
* We also assume that every scanline ends in a line break |
733 |
> |
* (0x0000) except for the last, which ends in a bitmap break |
734 |
> |
* (0x0001). We don't support RLE4 at all; it's too awkward. |
735 |
> |
*/ |
736 |
> |
sp = bw->scanline; |
737 |
> |
n = bw->hdr->width; |
738 |
> |
while (n > 0) { |
739 |
> |
int cnt, val; |
740 |
> |
|
741 |
> |
cnt = findNextRun(sp, n); /* 0-255 < n */ |
742 |
> |
if (cnt >= 3) { /* output non-run */ |
743 |
> |
int skipOdd = cnt & 1; |
744 |
> |
wrbyte(0, bw); |
745 |
> |
wrbyte(cnt, bw); |
746 |
> |
n -= cnt; |
747 |
> |
while (cnt--) |
748 |
> |
wrbyte(*sp++, bw); |
749 |
> |
if (skipOdd) |
750 |
> |
wrbyte(0, bw); |
751 |
> |
} |
752 |
> |
if (n <= 0) /* was that it? */ |
753 |
> |
break; |
754 |
> |
val = *sp; /* output run */ |
755 |
> |
for (cnt = 1; cnt < 255; cnt++) |
756 |
> |
if (!--n | *++sp != val) |
757 |
> |
break; |
758 |
> |
wrbyte(cnt, bw); |
759 |
> |
wrbyte(val, bw); |
760 |
> |
} |
761 |
> |
bw->yscan++; /* write line break or EOD */ |
762 |
|
if (bw->yscan == bw->hdr->height) { |
763 |
+ |
wrbyte(0, bw); wrbyte(1, bw); /* end of bitmap marker */ |
764 |
|
if (bw->seek == NULL || (*bw->seek)(2, bw->c_data) != 0) |
765 |
< |
return BIR_SEEKERR; |
765 |
> |
return BIR_OK; /* no one may care */ |
766 |
|
bw->fpos = 2; |
767 |
< |
wrint32(bw->flen, bw); |
767 |
> |
wrint32(bw->flen-bw->fbmp, bw); /* correct bitmap length */ |
768 |
> |
} else { |
769 |
> |
wrbyte(0, bw); wrbyte(0, bw); /* end of line marker */ |
770 |
|
} |
771 |
|
return BIR_OK; |
772 |
|
} |