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root/radiance/ray/src/rt/rpict.c
Revision: 2.66
Committed: Wed Nov 26 19:16:24 2003 UTC (20 years, 5 months ago) by greg
Content type: text/plain
Branch: MAIN
Changes since 2.65: +1 -2 lines
Log Message:
Minor code improvements

File Contents

# Content
1 #ifndef lint
2 static const char RCSid[] = "$Id";
3 #endif
4 /*
5 * rpict.c - routines and variables for picture generation.
6 */
7
8 #include "copyright.h"
9
10 #include "platform.h"
11 #include "ray.h"
12
13 #include <sys/types.h>
14
15 #ifndef NON_POSIX
16 #ifdef BSD
17 #include <sys/time.h>
18 #include <sys/resource.h>
19 #else
20 #include <sys/times.h>
21 #include <unistd.h>
22 #endif
23 #endif
24
25 #include <time.h>
26 #include <signal.h>
27
28 #include "view.h"
29 #include "random.h"
30 #include "paths.h"
31 #include "rtmisc.h" /* myhostname() */
32
33
34 #define RFTEMPLATE "rfXXXXXX"
35
36 #ifndef SIGCONT
37 #ifdef SIGIO /* XXX can we live without this? */
38 #define SIGCONT SIGIO
39 #endif
40 #endif
41
42 CUBE thescene; /* our scene */
43 OBJECT nsceneobjs; /* number of objects in our scene */
44
45 int dimlist[MAXDIM]; /* sampling dimensions */
46 int ndims = 0; /* number of sampling dimensions */
47 int samplendx; /* sample index number */
48
49 extern void ambnotify();
50 void (*addobjnotify[])() = {ambnotify, NULL};
51
52 VIEW ourview = STDVIEW; /* view parameters */
53 int hresolu = 512; /* horizontal resolution */
54 int vresolu = 512; /* vertical resolution */
55 double pixaspect = 1.0; /* pixel aspect ratio */
56
57 int psample = 4; /* pixel sample size */
58 double maxdiff = .05; /* max. difference for interpolation */
59 double dstrpix = 0.67; /* square pixel distribution */
60
61 double mblur = 0.; /* motion blur parameter */
62
63 void (*trace)() = NULL; /* trace call */
64
65 int do_irrad = 0; /* compute irradiance? */
66
67 double dstrsrc = 0.0; /* square source distribution */
68 double shadthresh = .05; /* shadow threshold */
69 double shadcert = .5; /* shadow certainty */
70 int directrelay = 1; /* number of source relays */
71 int vspretest = 512; /* virtual source pretest density */
72 int directvis = 1; /* sources visible? */
73 double srcsizerat = .25; /* maximum ratio source size/dist. */
74
75 COLOR cextinction = BLKCOLOR; /* global extinction coefficient */
76 COLOR salbedo = BLKCOLOR; /* global scattering albedo */
77 double seccg = 0.; /* global scattering eccentricity */
78 double ssampdist = 0.; /* scatter sampling distance */
79
80 double specthresh = .15; /* specular sampling threshold */
81 double specjitter = 1.; /* specular sampling jitter */
82
83 int backvis = 1; /* back face visibility */
84
85 int maxdepth = 7; /* maximum recursion depth */
86 double minweight = 4e-3; /* minimum ray weight */
87
88 char *ambfile = NULL; /* ambient file name */
89 COLOR ambval = BLKCOLOR; /* ambient value */
90 int ambvwt = 0; /* initial weight for ambient value */
91 double ambacc = 0.15; /* ambient accuracy */
92 int ambres = 64; /* ambient resolution */
93 int ambdiv = 512; /* ambient divisions */
94 int ambssamp = 128; /* ambient super-samples */
95 int ambounce = 0; /* ambient bounces */
96 char *amblist[128]; /* ambient include/exclude list */
97 int ambincl = -1; /* include == 1, exclude == 0 */
98
99 int ralrm = 0; /* seconds between reports */
100
101 double pctdone = 0.0; /* percentage done */
102 time_t tlastrept = 0L; /* time at last report */
103 time_t tstart; /* starting time */
104
105 #define MAXDIV 16 /* maximum sample size */
106
107 #define pixjitter() (.5+dstrpix*(.5-frandom()))
108
109 int hres, vres; /* resolution for this frame */
110
111 static VIEW lastview; /* the previous view input */
112
113 extern char *mktemp(); /* XXX should be in stdlib.h or unistd.h */
114
115 void report();
116
117 double pixvalue();
118
119 #ifdef RHAS_STAT
120 #include <sys/types.h>
121 #include <sys/stat.h>
122 int
123 file_exists(fname) /* ordinary file exists? */
124 char *fname;
125 {
126 struct stat sbuf;
127 if (stat(fname, &sbuf) < 0) return(0);
128 return((sbuf.st_mode & S_IFREG) != 0);
129 }
130 #else
131 #define file_exists(f) (access(f,F_OK)==0)
132 #endif
133
134
135 void
136 quit(code) /* quit program */
137 int code;
138 {
139 if (code) /* report status */
140 report();
141 #ifndef NON_POSIX
142 headclean(); /* delete header file */
143 pfclean(); /* clean up persist files */
144 #endif
145 exit(code);
146 }
147
148
149 #ifndef NON_POSIX
150 void
151 report() /* report progress */
152 {
153 double u, s;
154 #ifdef BSD
155 struct rusage rubuf;
156 #else
157 struct tms tbuf;
158 double period;
159 #endif
160
161 tlastrept = time((time_t *)NULL);
162 #ifdef BSD
163 getrusage(RUSAGE_SELF, &rubuf);
164 u = rubuf.ru_utime.tv_sec + rubuf.ru_utime.tv_usec/1e6;
165 s = rubuf.ru_stime.tv_sec + rubuf.ru_stime.tv_usec/1e6;
166 getrusage(RUSAGE_CHILDREN, &rubuf);
167 u += rubuf.ru_utime.tv_sec + rubuf.ru_utime.tv_usec/1e6;
168 s += rubuf.ru_stime.tv_sec + rubuf.ru_stime.tv_usec/1e6;
169 #else
170 times(&tbuf);
171 #ifdef _SC_CLK_TCK
172 period = 1.0 / sysconf(_SC_CLK_TCK);
173 #else
174 period = 1.0 / 60.0;
175 #endif
176 u = ( tbuf.tms_utime + tbuf.tms_cutime ) * period;
177 s = ( tbuf.tms_stime + tbuf.tms_cstime ) * period;
178 #endif
179
180 sprintf(errmsg,
181 "%lu rays, %4.2f%% after %.3fu %.3fs %.3fr hours on %s\n",
182 nrays, pctdone, u/3600., s/3600.,
183 (tlastrept-tstart)/3600., myhostname());
184 eputs(errmsg);
185 #ifdef SIGCONT
186 signal(SIGCONT, report);
187 #endif
188 }
189 #else
190 void
191 report() /* report progress */
192 {
193 tlastrept = time((time_t *)NULL);
194 sprintf(errmsg, "%lu rays, %4.2f%% after %5.4f hours\n",
195 nrays, pctdone, (tlastrept-tstart)/3600.0);
196 eputs(errmsg);
197 }
198 #endif
199
200
201 void
202 rpict(seq, pout, zout, prvr) /* generate image(s) */
203 int seq;
204 char *pout, *zout, *prvr;
205 /*
206 * If seq is greater than zero, then we will render a sequence of
207 * images based on view parameter strings read from the standard input.
208 * If pout is NULL, then all images will be sent to the standard ouput.
209 * If seq is greater than zero and prvr is an integer, then it is the
210 * frame number at which rendering should begin. Preceeding view parameter
211 * strings will be skipped in the input.
212 * If pout and prvr are the same, prvr is renamed to avoid overwriting.
213 * Note that pout and zout should contain %d format specifications for
214 * sequenced file naming.
215 */
216 {
217 char fbuf[128], fbuf2[128];
218 int npicts;
219 register char *cp;
220 RESOLU rs;
221 double pa;
222 /* check sampling */
223 if (psample < 1)
224 psample = 1;
225 else if (psample > MAXDIV) {
226 sprintf(errmsg, "pixel sampling reduced from %d to %d",
227 psample, MAXDIV);
228 error(WARNING, errmsg);
229 psample = MAXDIV;
230 }
231 /* get starting frame */
232 if (seq <= 0)
233 seq = 0;
234 else if (prvr != NULL && isint(prvr)) {
235 register int rn; /* skip to specified view */
236 if ((rn = atoi(prvr)) < seq)
237 error(USER, "recover frame less than start frame");
238 if (pout == NULL)
239 error(USER, "missing output file specification");
240 for ( ; seq < rn; seq++)
241 if (nextview(stdin) == EOF)
242 error(USER, "unexpected EOF on view input");
243 setview(&ourview);
244 prvr = fbuf; /* mark for renaming */
245 }
246 if ((pout != NULL) & (prvr != NULL)) {
247 sprintf(fbuf, pout, seq);
248 if (!strcmp(prvr, fbuf)) { /* rename */
249 strcpy(fbuf2, fbuf);
250 for (cp = fbuf2; *cp; cp++)
251 ;
252 while (cp > fbuf2 && !ISDIRSEP(cp[-1]))
253 cp--;
254 strcpy(cp, RFTEMPLATE);
255 prvr = mktemp(fbuf2);
256 if (rename(fbuf, prvr) < 0) {
257 if (errno == ENOENT) { /* ghost file */
258 sprintf(errmsg,
259 "new output file \"%s\"",
260 fbuf);
261 error(WARNING, errmsg);
262 prvr = NULL;
263 } else { /* serious error */
264 sprintf(errmsg,
265 "cannot rename \"%s\" to \"%s\"",
266 fbuf, prvr);
267 error(SYSTEM, errmsg);
268 }
269 }
270 }
271 }
272 npicts = 0; /* render sequence */
273 do {
274 if (seq && nextview(stdin) == EOF)
275 break;
276 pctdone = 0.0;
277 if (pout != NULL) {
278 sprintf(fbuf, pout, seq);
279 if (file_exists(fbuf)) {
280 if (prvr != NULL || !strcmp(fbuf, pout)) {
281 sprintf(errmsg,
282 "output file \"%s\" exists",
283 fbuf);
284 error(USER, errmsg);
285 }
286 setview(&ourview);
287 continue; /* don't clobber */
288 }
289 if (freopen(fbuf, "w", stdout) == NULL) {
290 sprintf(errmsg,
291 "cannot open output file \"%s\"", fbuf);
292 error(SYSTEM, errmsg);
293 }
294 SET_FILE_BINARY(stdout);
295 dupheader();
296 }
297 hres = hresolu; vres = vresolu; pa = pixaspect;
298 if (prvr != NULL) {
299 if (viewfile(prvr, &ourview, &rs) <= 0) {
300 sprintf(errmsg,
301 "cannot recover view parameters from \"%s\"", prvr);
302 error(WARNING, errmsg);
303 } else {
304 pa = 0.0;
305 hres = scanlen(&rs);
306 vres = numscans(&rs);
307 }
308 }
309 if ((cp = setview(&ourview)) != NULL)
310 error(USER, cp);
311 normaspect(viewaspect(&ourview), &pa, &hres, &vres);
312 if (seq) {
313 if (ralrm > 0) {
314 fprintf(stderr, "FRAME %d:", seq);
315 fprintview(&ourview, stderr);
316 putc('\n', stderr);
317 fflush(stderr);
318 }
319 printf("FRAME=%d\n", seq);
320 }
321 fputs(VIEWSTR, stdout);
322 fprintview(&ourview, stdout);
323 putchar('\n');
324 if (pa < .99 || pa > 1.01)
325 fputaspect(pa, stdout);
326 fputnow(stdout);
327 fputformat(COLRFMT, stdout);
328 putchar('\n');
329 if (zout != NULL)
330 sprintf(cp=fbuf, zout, seq);
331 else
332 cp = NULL;
333 render(cp, prvr);
334 prvr = NULL;
335 npicts++;
336 } while (seq++);
337 /* check that we did something */
338 if (npicts == 0)
339 error(WARNING, "no output produced");
340 }
341
342
343 nextview(fp) /* get next view from fp */
344 FILE *fp;
345 {
346 char linebuf[256];
347
348 lastview = ourview;
349 while (fgets(linebuf, sizeof(linebuf), fp) != NULL)
350 if (isview(linebuf) && sscanview(&ourview, linebuf) > 0)
351 return(0);
352 return(EOF);
353 }
354
355
356 render(zfile, oldfile) /* render the scene */
357 char *zfile, *oldfile;
358 {
359 COLOR *scanbar[MAXDIV+1]; /* scanline arrays of pixel values */
360 float *zbar[MAXDIV+1]; /* z values */
361 char *sampdens; /* previous sample density */
362 int ypos; /* current scanline */
363 int ystep; /* current y step size */
364 int hstep; /* h step size */
365 int zfd;
366 COLOR *colptr;
367 float *zptr;
368 register int i;
369 /* check for empty image */
370 if (hres <= 0 || vres <= 0) {
371 error(WARNING, "empty output picture");
372 fprtresolu(0, 0, stdout);
373 return;
374 }
375 /* allocate scanlines */
376 for (i = 0; i <= psample; i++) {
377 scanbar[i] = (COLOR *)malloc(hres*sizeof(COLOR));
378 if (scanbar[i] == NULL)
379 goto memerr;
380 }
381 hstep = (psample*140+49)/99; /* quincunx sampling */
382 ystep = (psample*99+70)/140;
383 if (hstep > 2) {
384 i = hres/hstep + 2;
385 if ((sampdens = (char *)malloc(i)) == NULL)
386 goto memerr;
387 while (i--)
388 sampdens[i] = hstep;
389 } else
390 sampdens = NULL;
391 /* open z-file */
392 if (zfile != NULL) {
393 if ((zfd = open(zfile, O_WRONLY|O_CREAT, 0666)) == -1) {
394 sprintf(errmsg, "cannot open z-file \"%s\"", zfile);
395 error(SYSTEM, errmsg);
396 }
397 SET_FD_BINARY(zfd);
398 for (i = 0; i <= psample; i++) {
399 zbar[i] = (float *)malloc(hres*sizeof(float));
400 if (zbar[i] == NULL)
401 goto memerr;
402 }
403 } else {
404 zfd = -1;
405 for (i = 0; i <= psample; i++)
406 zbar[i] = NULL;
407 }
408 /* write out boundaries */
409 fprtresolu(hres, vres, stdout);
410 /* recover file and compute first */
411 i = salvage(oldfile);
412 if (i >= vres)
413 goto alldone;
414 if (zfd != -1 && i > 0 &&
415 lseek(zfd, (off_t)i*hres*sizeof(float), SEEK_SET) < 0)
416 error(SYSTEM, "z-file seek error in render");
417 pctdone = 100.0*i/vres;
418 if (ralrm > 0) /* report init stats */
419 report();
420 #ifdef SIGCONT
421 else
422 signal(SIGCONT, report);
423 #endif
424 ypos = vres-1 - i; /* initialize sampling */
425 if (directvis)
426 init_drawsources(psample);
427 fillscanline(scanbar[0], zbar[0], sampdens, hres, ypos, hstep);
428 /* compute scanlines */
429 for (ypos -= ystep; ypos > -ystep; ypos -= ystep) {
430 /* bottom adjust? */
431 if (ypos < 0) {
432 ystep += ypos;
433 ypos = 0;
434 }
435 colptr = scanbar[ystep]; /* move base to top */
436 scanbar[ystep] = scanbar[0];
437 scanbar[0] = colptr;
438 zptr = zbar[ystep];
439 zbar[ystep] = zbar[0];
440 zbar[0] = zptr;
441 /* fill base line */
442 fillscanline(scanbar[0], zbar[0], sampdens,
443 hres, ypos, hstep);
444 /* fill bar */
445 fillscanbar(scanbar, zbar, hres, ypos, ystep);
446 if (directvis) /* add bitty sources */
447 drawsources(scanbar, zbar, 0, hres, ypos, ystep);
448 /* write it out */
449 #ifdef SIGCONT
450 signal(SIGCONT, SIG_IGN); /* don't interrupt writes */
451 #endif
452 for (i = ystep; i > 0; i--) {
453 if (zfd != -1 && write(zfd, (char *)zbar[i],
454 hres*sizeof(float))
455 < hres*sizeof(float))
456 goto writerr;
457 if (fwritescan(scanbar[i], hres, stdout) < 0)
458 goto writerr;
459 }
460 if (fflush(stdout) == EOF)
461 goto writerr;
462 /* record progress */
463 pctdone = 100.0*(vres-1-ypos)/vres;
464 if (ralrm > 0 && time((time_t *)NULL) >= tlastrept+ralrm)
465 report();
466 #ifdef SIGCONT
467 else
468 signal(SIGCONT, report);
469 #endif
470 }
471 /* clean up */
472 #ifdef SIGCONT
473 signal(SIGCONT, SIG_IGN);
474 #endif
475 if (zfd != -1 && write(zfd, (char *)zbar[0], hres*sizeof(float))
476 < hres*sizeof(float))
477 goto writerr;
478 fwritescan(scanbar[0], hres, stdout);
479 if (fflush(stdout) == EOF)
480 goto writerr;
481 alldone:
482 if (zfd != -1) {
483 if (close(zfd) == -1)
484 goto writerr;
485 for (i = 0; i <= psample; i++)
486 free((void *)zbar[i]);
487 }
488 for (i = 0; i <= psample; i++)
489 free((void *)scanbar[i]);
490 if (sampdens != NULL)
491 free(sampdens);
492 pctdone = 100.0;
493 if (ralrm > 0)
494 report();
495 #ifdef SIGCONT
496 signal(SIGCONT, SIG_DFL);
497 #endif
498 return;
499 writerr:
500 error(SYSTEM, "write error in render");
501 memerr:
502 error(SYSTEM, "out of memory in render");
503 }
504
505
506 fillscanline(scanline, zline, sd, xres, y, xstep) /* fill scan at y */
507 register COLOR *scanline;
508 register float *zline;
509 register char *sd;
510 int xres, y, xstep;
511 {
512 static int nc = 0; /* number of calls */
513 int bl = xstep, b = xstep;
514 double z;
515 register int i;
516
517 z = pixvalue(scanline[0], 0, y);
518 if (zline) zline[0] = z;
519 /* zig-zag start for quincunx pattern */
520 for (i = ++nc & 1 ? xstep : xstep/2; i < xres-1+xstep; i += xstep) {
521 if (i >= xres) {
522 xstep += xres-1-i;
523 i = xres-1;
524 }
525 z = pixvalue(scanline[i], i, y);
526 if (zline) zline[i] = z;
527 if (sd) b = sd[0] > sd[1] ? sd[0] : sd[1];
528 if (i <= xstep)
529 b = fillsample(scanline, zline, 0, y, i, 0, b/2);
530 else
531 b = fillsample(scanline+i-xstep,
532 zline ? zline+i-xstep : (float *)NULL,
533 i-xstep, y, xstep, 0, b/2);
534 if (sd) *sd++ = nc & 1 ? bl : b;
535 bl = b;
536 }
537 if (sd && nc & 1) *sd = bl;
538 }
539
540
541 fillscanbar(scanbar, zbar, xres, y, ysize) /* fill interior */
542 register COLOR *scanbar[];
543 register float *zbar[];
544 int xres, y, ysize;
545 {
546 COLOR vline[MAXDIV+1];
547 float zline[MAXDIV+1];
548 int b = ysize;
549 register int i, j;
550
551 for (i = 0; i < xres; i++) {
552 copycolor(vline[0], scanbar[0][i]);
553 copycolor(vline[ysize], scanbar[ysize][i]);
554 if (zbar[0]) {
555 zline[0] = zbar[0][i];
556 zline[ysize] = zbar[ysize][i];
557 }
558 b = fillsample(vline, zbar[0] ? zline : (float *)NULL,
559 i, y, 0, ysize, b/2);
560
561 for (j = 1; j < ysize; j++)
562 copycolor(scanbar[j][i], vline[j]);
563 if (zbar[0])
564 for (j = 1; j < ysize; j++)
565 zbar[j][i] = zline[j];
566 }
567 }
568
569
570 int
571 fillsample(colline, zline, x, y, xlen, ylen, b) /* fill interior points */
572 register COLOR *colline;
573 register float *zline;
574 int x, y;
575 int xlen, ylen;
576 int b;
577 {
578 double ratio;
579 double z;
580 COLOR ctmp;
581 int ncut;
582 register int len;
583
584 if (xlen > 0) /* x or y length is zero */
585 len = xlen;
586 else
587 len = ylen;
588
589 if (len <= 1) /* limit recursion */
590 return(0);
591
592 if (b > 0 ||
593 (zline && 2.*fabs(zline[0]-zline[len]) > maxdiff*(zline[0]+zline[len]))
594 || bigdiff(colline[0], colline[len], maxdiff)) {
595
596 z = pixvalue(colline[len>>1], x + (xlen>>1), y + (ylen>>1));
597 if (zline) zline[len>>1] = z;
598 ncut = 1;
599 } else { /* interpolate */
600 copycolor(colline[len>>1], colline[len]);
601 ratio = (double)(len>>1) / len;
602 scalecolor(colline[len>>1], ratio);
603 if (zline) zline[len>>1] = zline[len] * ratio;
604 ratio = 1.0 - ratio;
605 copycolor(ctmp, colline[0]);
606 scalecolor(ctmp, ratio);
607 addcolor(colline[len>>1], ctmp);
608 if (zline) zline[len>>1] += zline[0] * ratio;
609 ncut = 0;
610 }
611 /* recurse */
612 ncut += fillsample(colline, zline, x, y, xlen>>1, ylen>>1, (b-1)/2);
613
614 ncut += fillsample(colline+(len>>1),
615 zline ? zline+(len>>1) : (float *)NULL,
616 x+(xlen>>1), y+(ylen>>1),
617 xlen-(xlen>>1), ylen-(ylen>>1), b/2);
618
619 return(ncut);
620 }
621
622
623 double
624 pixvalue(col, x, y) /* compute pixel value */
625 COLOR col; /* returned color */
626 int x, y; /* pixel position */
627 {
628 RAY thisray;
629 FVECT lorg, ldir;
630 double hpos, vpos, lmax, d;
631 /* compute view ray */
632 hpos = (x+pixjitter())/hres;
633 vpos = (y+pixjitter())/vres;
634 if ((thisray.rmax = viewray(thisray.rorg, thisray.rdir,
635 &ourview, hpos, vpos)) < -FTINY) {
636 setcolor(col, 0.0, 0.0, 0.0);
637 return(0.0);
638 }
639
640 samplendx = pixnumber(x,y,hres,vres); /* set pixel index */
641
642 /* optional motion blur */
643 if (lastview.type && mblur > FTINY && (lmax = viewray(lorg, ldir,
644 &lastview, hpos, vpos)) >= -FTINY) {
645 register int i;
646 register double d = mblur*(.5-urand(281+samplendx));
647
648 thisray.rmax = (1.-d)*thisray.rmax + d*lmax;
649 for (i = 3; i--; ) {
650 thisray.rorg[i] = (1.-d)*thisray.rorg[i] + d*lorg[i];
651 thisray.rdir[i] = (1.-d)*thisray.rdir[i] + d*ldir[i];
652 }
653 if (normalize(thisray.rdir) == 0.0)
654 return(0.0);
655 }
656
657 rayorigin(&thisray, NULL, PRIMARY, 1.0);
658
659 rayvalue(&thisray); /* trace ray */
660
661 copycolor(col, thisray.rcol); /* return color */
662
663 return(thisray.rt); /* return distance */
664 }
665
666
667 int
668 salvage(oldfile) /* salvage scanlines from killed program */
669 char *oldfile;
670 {
671 COLR *scanline;
672 FILE *fp;
673 int x, y;
674
675 if (oldfile == NULL)
676 goto gotzip;
677
678 if ((fp = fopen(oldfile, "r")) == NULL) {
679 sprintf(errmsg, "cannot open recover file \"%s\"", oldfile);
680 error(WARNING, errmsg);
681 goto gotzip;
682 }
683 SET_FILE_BINARY(fp);
684 /* discard header */
685 getheader(fp, NULL, NULL);
686 /* get picture size */
687 if (!fscnresolu(&x, &y, fp)) {
688 sprintf(errmsg, "bad recover file \"%s\" - not removed",
689 oldfile);
690 error(WARNING, errmsg);
691 fclose(fp);
692 goto gotzip;
693 }
694
695 if (x != hres || y != vres) {
696 sprintf(errmsg, "resolution mismatch in recover file \"%s\"",
697 oldfile);
698 error(USER, errmsg);
699 }
700
701 scanline = (COLR *)malloc(hres*sizeof(COLR));
702 if (scanline == NULL)
703 error(SYSTEM, "out of memory in salvage");
704 for (y = 0; y < vres; y++) {
705 if (freadcolrs(scanline, hres, fp) < 0)
706 break;
707 if (fwritecolrs(scanline, hres, stdout) < 0)
708 goto writerr;
709 }
710 if (fflush(stdout) == EOF)
711 goto writerr;
712 free((void *)scanline);
713 fclose(fp);
714 unlink(oldfile);
715 return(y);
716 gotzip:
717 if (fflush(stdout) == EOF)
718 error(SYSTEM, "error writing picture header");
719 return(0);
720 writerr:
721 sprintf(errmsg, "write error during recovery of \"%s\"", oldfile);
722 error(SYSTEM, errmsg);
723 }
724
725
726 int
727 pixnumber(x, y, xres, yres) /* compute pixel index (brushed) */
728 register int x, y;
729 int xres, yres;
730 {
731 x -= y;
732 while (x < 0)
733 x += xres;
734 return((((x>>2)*yres + y) << 2) + (x & 3));
735 }