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root/radiance/ray/src/rt/rpict.c
Revision: 2.60
Committed: Thu Jul 3 21:44:41 2003 UTC (20 years, 10 months ago) by schorsch
Content type: text/plain
Branch: MAIN
Changes since 2.59: +2 -2 lines
Log Message:
Fixed fputnow() call to match prototype.

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
32
33 #define RFTEMPLATE "rfXXXXXX"
34
35 #ifndef SIGCONT
36 #ifdef SIGIO /* XXX can we live without this? */
37 #define SIGCONT SIGIO
38 #endif
39 #endif
40
41 CUBE thescene; /* our scene */
42 OBJECT nsceneobjs; /* number of objects in our scene */
43
44 int dimlist[MAXDIM]; /* sampling dimensions */
45 int ndims = 0; /* number of sampling dimensions */
46 int samplendx; /* sample index number */
47
48 extern void ambnotify();
49 void (*addobjnotify[])() = {ambnotify, NULL};
50
51 VIEW ourview = STDVIEW; /* view parameters */
52 int hresolu = 512; /* horizontal resolution */
53 int vresolu = 512; /* vertical resolution */
54 double pixaspect = 1.0; /* pixel aspect ratio */
55
56 int psample = 4; /* pixel sample size */
57 double maxdiff = .05; /* max. difference for interpolation */
58 double dstrpix = 0.67; /* square pixel distribution */
59
60 double mblur = 0.; /* motion blur parameter */
61
62 void (*trace)() = NULL; /* trace call */
63
64 int do_irrad = 0; /* compute irradiance? */
65
66 double dstrsrc = 0.0; /* square source distribution */
67 double shadthresh = .05; /* shadow threshold */
68 double shadcert = .5; /* shadow certainty */
69 int directrelay = 1; /* number of source relays */
70 int vspretest = 512; /* virtual source pretest density */
71 int directvis = 1; /* sources visible? */
72 double srcsizerat = .25; /* maximum ratio source size/dist. */
73
74 COLOR cextinction = BLKCOLOR; /* global extinction coefficient */
75 COLOR salbedo = BLKCOLOR; /* global scattering albedo */
76 double seccg = 0.; /* global scattering eccentricity */
77 double ssampdist = 0.; /* scatter sampling distance */
78
79 double specthresh = .15; /* specular sampling threshold */
80 double specjitter = 1.; /* specular sampling jitter */
81
82 int backvis = 1; /* back face visibility */
83
84 int maxdepth = 6; /* maximum recursion depth */
85 double minweight = 5e-3; /* minimum ray weight */
86
87 char *ambfile = NULL; /* ambient file name */
88 COLOR ambval = BLKCOLOR; /* ambient value */
89 int ambvwt = 0; /* initial weight for ambient value */
90 double ambacc = 0.2; /* ambient accuracy */
91 int ambres = 32; /* ambient resolution */
92 int ambdiv = 128; /* ambient divisions */
93 int ambssamp = 0; /* ambient super-samples */
94 int ambounce = 0; /* ambient bounces */
95 char *amblist[128]; /* ambient include/exclude list */
96 int ambincl = -1; /* include == 1, exclude == 0 */
97
98 int ralrm = 0; /* seconds between reports */
99
100 double pctdone = 0.0; /* percentage done */
101 time_t tlastrept = 0L; /* time at last report */
102 time_t tstart; /* starting time */
103
104 #define MAXDIV 16 /* maximum sample size */
105
106 #define pixjitter() (.5+dstrpix*(.5-frandom()))
107
108 int hres, vres; /* resolution for this frame */
109
110 static VIEW lastview; /* the previous view input */
111
112 extern char *mktemp(); /* XXX should be in stdlib.h or unistd.h */
113
114 void report();
115
116 double pixvalue();
117
118 #ifdef RHAS_STAT
119 #include <sys/types.h>
120 #include <sys/stat.h>
121 int
122 file_exists(fname) /* ordinary file exists? */
123 char *fname;
124 {
125 struct stat sbuf;
126 if (stat(fname, &sbuf) < 0) return(0);
127 return((sbuf.st_mode & S_IFREG) != 0);
128 }
129 #else
130 #define file_exists(f) (access(f,F_OK)==0)
131 #endif
132
133
134 void
135 quit(code) /* quit program */
136 int code;
137 {
138 if (code) /* report status */
139 report();
140 #ifndef NON_POSIX
141 headclean(); /* delete header file */
142 pfclean(); /* clean up persist files */
143 #endif
144 exit(code);
145 }
146
147
148 #ifndef NON_POSIX
149 void
150 report() /* report progress */
151 {
152 extern char *myhostname();
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 npicts = 0; /* render sequence */
272 do {
273 if (seq && nextview(stdin) == EOF)
274 break;
275 pctdone = 0.0;
276 if (pout != NULL) {
277 sprintf(fbuf, pout, seq);
278 if (file_exists(fbuf)) {
279 if (prvr != NULL || !strcmp(fbuf, pout)) {
280 sprintf(errmsg,
281 "output file \"%s\" exists",
282 fbuf);
283 error(USER, errmsg);
284 }
285 setview(&ourview);
286 continue; /* don't clobber */
287 }
288 if (freopen(fbuf, "w", stdout) == NULL) {
289 sprintf(errmsg,
290 "cannot open output file \"%s\"", fbuf);
291 error(SYSTEM, errmsg);
292 }
293 SET_FILE_BINARY(stdout);
294 dupheader();
295 }
296 hres = hresolu; vres = vresolu; pa = pixaspect;
297 if (prvr != NULL)
298 if (viewfile(prvr, &ourview, &rs) <= 0
299 || rs.rt != PIXSTANDARD) {
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 if ((cp = setview(&ourview)) != NULL)
309 error(USER, cp);
310 normaspect(viewaspect(&ourview), &pa, &hres, &vres);
311 if (seq) {
312 if (ralrm > 0) {
313 fprintf(stderr, "FRAME %d:", seq);
314 fprintview(&ourview, stderr);
315 putc('\n', stderr);
316 fflush(stderr);
317 }
318 printf("FRAME=%d\n", seq);
319 }
320 fputs(VIEWSTR, stdout);
321 fprintview(&ourview, stdout);
322 putchar('\n');
323 if (pa < .99 || pa > 1.01)
324 fputaspect(pa, stdout);
325 fputnow(stdout);
326 fputformat(COLRFMT, stdout);
327 putchar('\n');
328 if (zout != NULL)
329 sprintf(cp=fbuf, zout, seq);
330 else
331 cp = NULL;
332 render(cp, prvr);
333 prvr = NULL;
334 npicts++;
335 } while (seq++);
336 /* check that we did something */
337 if (npicts == 0)
338 error(WARNING, "no output produced");
339 }
340
341
342 nextview(fp) /* get next view from fp */
343 FILE *fp;
344 {
345 char linebuf[256];
346
347 copystruct(&lastview, &ourview);
348 while (fgets(linebuf, sizeof(linebuf), fp) != NULL)
349 if (isview(linebuf) && sscanview(&ourview, linebuf) > 0)
350 return(0);
351 return(EOF);
352 }
353
354
355 render(zfile, oldfile) /* render the scene */
356 char *zfile, *oldfile;
357 {
358 COLOR *scanbar[MAXDIV+1]; /* scanline arrays of pixel values */
359 float *zbar[MAXDIV+1]; /* z values */
360 char *sampdens; /* previous sample density */
361 int ypos; /* current scanline */
362 int ystep; /* current y step size */
363 int hstep; /* h step size */
364 int zfd;
365 COLOR *colptr;
366 float *zptr;
367 register int i;
368 /* check for empty image */
369 if (hres <= 0 || vres <= 0) {
370 error(WARNING, "empty output picture");
371 fprtresolu(0, 0, stdout);
372 return;
373 }
374 /* allocate scanlines */
375 for (i = 0; i <= psample; i++) {
376 scanbar[i] = (COLOR *)malloc(hres*sizeof(COLOR));
377 if (scanbar[i] == NULL)
378 goto memerr;
379 }
380 hstep = (psample*140+49)/99; /* quincunx sampling */
381 ystep = (psample*99+70)/140;
382 if (hstep > 2) {
383 i = hres/hstep + 2;
384 if ((sampdens = (char *)malloc(i)) == NULL)
385 goto memerr;
386 while (i--)
387 sampdens[i] = hstep;
388 } else
389 sampdens = NULL;
390 /* open z-file */
391 if (zfile != NULL) {
392 if ((zfd = open(zfile, O_WRONLY|O_CREAT, 0666)) == -1) {
393 sprintf(errmsg, "cannot open z-file \"%s\"", zfile);
394 error(SYSTEM, errmsg);
395 }
396 SET_FD_BINARY(zfd);
397 for (i = 0; i <= psample; i++) {
398 zbar[i] = (float *)malloc(hres*sizeof(float));
399 if (zbar[i] == NULL)
400 goto memerr;
401 }
402 } else {
403 zfd = -1;
404 for (i = 0; i <= psample; i++)
405 zbar[i] = NULL;
406 }
407 /* write out boundaries */
408 fprtresolu(hres, vres, stdout);
409 /* recover file and compute first */
410 i = salvage(oldfile);
411 if (i >= vres)
412 goto alldone;
413 if (zfd != -1 && i > 0 &&
414 lseek(zfd, (off_t)i*hres*sizeof(float), 0) < 0)
415 error(SYSTEM, "z-file seek error in render");
416 pctdone = 100.0*i/vres;
417 if (ralrm > 0) /* report init stats */
418 report();
419 #ifdef SIGCONT
420 else
421 signal(SIGCONT, report);
422 #endif
423 ypos = vres-1 - i; /* initialize sampling */
424 if (directvis)
425 init_drawsources(psample);
426 fillscanline(scanbar[0], zbar[0], sampdens, hres, ypos, hstep);
427 /* compute scanlines */
428 for (ypos -= ystep; ypos > -ystep; ypos -= ystep) {
429 /* bottom adjust? */
430 if (ypos < 0) {
431 ystep += ypos;
432 ypos = 0;
433 }
434 colptr = scanbar[ystep]; /* move base to top */
435 scanbar[ystep] = scanbar[0];
436 scanbar[0] = colptr;
437 zptr = zbar[ystep];
438 zbar[ystep] = zbar[0];
439 zbar[0] = zptr;
440 /* fill base line */
441 fillscanline(scanbar[0], zbar[0], sampdens,
442 hres, ypos, hstep);
443 /* fill bar */
444 fillscanbar(scanbar, zbar, hres, ypos, ystep);
445 if (directvis) /* add bitty sources */
446 drawsources(scanbar, zbar, 0, hres, ypos, ystep);
447 /* write it out */
448 #ifdef SIGCONT
449 signal(SIGCONT, SIG_IGN); /* don't interrupt writes */
450 #endif
451 for (i = ystep; i > 0; i--) {
452 if (zfd != -1 && write(zfd, (char *)zbar[i],
453 hres*sizeof(float))
454 < hres*sizeof(float))
455 goto writerr;
456 if (fwritescan(scanbar[i], hres, stdout) < 0)
457 goto writerr;
458 }
459 if (fflush(stdout) == EOF)
460 goto writerr;
461 /* record progress */
462 pctdone = 100.0*(vres-1-ypos)/vres;
463 if (ralrm > 0 && time((time_t *)NULL) >= tlastrept+ralrm)
464 report();
465 #ifdef SIGCONT
466 else
467 signal(SIGCONT, report);
468 #endif
469 }
470 /* clean up */
471 #ifdef SIGCONT
472 signal(SIGCONT, SIG_IGN);
473 #endif
474 if (zfd != -1 && write(zfd, (char *)zbar[0], hres*sizeof(float))
475 < hres*sizeof(float))
476 goto writerr;
477 fwritescan(scanbar[0], hres, stdout);
478 if (fflush(stdout) == EOF)
479 goto writerr;
480 alldone:
481 if (zfd != -1) {
482 if (close(zfd) == -1)
483 goto writerr;
484 for (i = 0; i <= psample; i++)
485 free((void *)zbar[i]);
486 }
487 for (i = 0; i <= psample; i++)
488 free((void *)scanbar[i]);
489 if (sampdens != NULL)
490 free(sampdens);
491 pctdone = 100.0;
492 if (ralrm > 0)
493 report();
494 #ifdef SIGCONT
495 signal(SIGCONT, SIG_DFL);
496 #endif
497 return;
498 writerr:
499 error(SYSTEM, "write error in render");
500 memerr:
501 error(SYSTEM, "out of memory in render");
502 }
503
504
505 fillscanline(scanline, zline, sd, xres, y, xstep) /* fill scan at y */
506 register COLOR *scanline;
507 register float *zline;
508 register char *sd;
509 int xres, y, xstep;
510 {
511 static int nc = 0; /* number of calls */
512 int bl = xstep, b = xstep;
513 double z;
514 register int i;
515
516 z = pixvalue(scanline[0], 0, y);
517 if (zline) zline[0] = z;
518 /* zig-zag start for quincunx pattern */
519 for (i = ++nc & 1 ? xstep : xstep/2; i < xres-1+xstep; i += xstep) {
520 if (i >= xres) {
521 xstep += xres-1-i;
522 i = xres-1;
523 }
524 z = pixvalue(scanline[i], i, y);
525 if (zline) zline[i] = z;
526 if (sd) b = sd[0] > sd[1] ? sd[0] : sd[1];
527 if (i <= xstep)
528 b = fillsample(scanline, zline, 0, y, i, 0, b/2);
529 else
530 b = fillsample(scanline+i-xstep,
531 zline ? zline+i-xstep : (float *)NULL,
532 i-xstep, y, xstep, 0, b/2);
533 if (sd) *sd++ = nc & 1 ? bl : b;
534 bl = b;
535 }
536 if (sd && nc & 1) *sd = bl;
537 }
538
539
540 fillscanbar(scanbar, zbar, xres, y, ysize) /* fill interior */
541 register COLOR *scanbar[];
542 register float *zbar[];
543 int xres, y, ysize;
544 {
545 COLOR vline[MAXDIV+1];
546 float zline[MAXDIV+1];
547 int b = ysize;
548 register int i, j;
549
550 for (i = 0; i < xres; i++) {
551 copycolor(vline[0], scanbar[0][i]);
552 copycolor(vline[ysize], scanbar[ysize][i]);
553 if (zbar[0]) {
554 zline[0] = zbar[0][i];
555 zline[ysize] = zbar[ysize][i];
556 }
557 b = fillsample(vline, zbar[0] ? zline : (float *)NULL,
558 i, y, 0, ysize, b/2);
559
560 for (j = 1; j < ysize; j++)
561 copycolor(scanbar[j][i], vline[j]);
562 if (zbar[0])
563 for (j = 1; j < ysize; j++)
564 zbar[j][i] = zline[j];
565 }
566 }
567
568
569 int
570 fillsample(colline, zline, x, y, xlen, ylen, b) /* fill interior points */
571 register COLOR *colline;
572 register float *zline;
573 int x, y;
574 int xlen, ylen;
575 int b;
576 {
577 double ratio;
578 double z;
579 COLOR ctmp;
580 int ncut;
581 register int len;
582
583 if (xlen > 0) /* x or y length is zero */
584 len = xlen;
585 else
586 len = ylen;
587
588 if (len <= 1) /* limit recursion */
589 return(0);
590
591 if (b > 0 ||
592 (zline && 2.*fabs(zline[0]-zline[len]) > maxdiff*(zline[0]+zline[len]))
593 || bigdiff(colline[0], colline[len], maxdiff)) {
594
595 z = pixvalue(colline[len>>1], x + (xlen>>1), y + (ylen>>1));
596 if (zline) zline[len>>1] = z;
597 ncut = 1;
598 } else { /* interpolate */
599 copycolor(colline[len>>1], colline[len]);
600 ratio = (double)(len>>1) / len;
601 scalecolor(colline[len>>1], ratio);
602 if (zline) zline[len>>1] = zline[len] * ratio;
603 ratio = 1.0 - ratio;
604 copycolor(ctmp, colline[0]);
605 scalecolor(ctmp, ratio);
606 addcolor(colline[len>>1], ctmp);
607 if (zline) zline[len>>1] += zline[0] * ratio;
608 ncut = 0;
609 }
610 /* recurse */
611 ncut += fillsample(colline, zline, x, y, xlen>>1, ylen>>1, (b-1)/2);
612
613 ncut += fillsample(colline+(len>>1),
614 zline ? zline+(len>>1) : (float *)NULL,
615 x+(xlen>>1), y+(ylen>>1),
616 xlen-(xlen>>1), ylen-(ylen>>1), b/2);
617
618 return(ncut);
619 }
620
621
622 double
623 pixvalue(col, x, y) /* compute pixel value */
624 COLOR col; /* returned color */
625 int x, y; /* pixel position */
626 {
627 RAY thisray;
628 FVECT lorg, ldir;
629 double hpos, vpos, lmax, d;
630 /* compute view ray */
631 hpos = (x+pixjitter())/hres;
632 vpos = (y+pixjitter())/vres;
633 if ((thisray.rmax = viewray(thisray.rorg, thisray.rdir,
634 &ourview, hpos, vpos)) < -FTINY) {
635 setcolor(col, 0.0, 0.0, 0.0);
636 return(0.0);
637 }
638
639 samplendx = pixnumber(x,y,hres,vres); /* set pixel index */
640
641 /* optional motion blur */
642 if (lastview.type && mblur > FTINY && (lmax = viewray(lorg, ldir,
643 &lastview, hpos, vpos)) >= -FTINY) {
644 register int i;
645 register double d = mblur*(.5-urand(281+samplendx));
646
647 thisray.rmax = (1.-d)*thisray.rmax + d*lmax;
648 for (i = 3; i--; ) {
649 thisray.rorg[i] = (1.-d)*thisray.rorg[i] + d*lorg[i];
650 thisray.rdir[i] = (1.-d)*thisray.rdir[i] + d*ldir[i];
651 }
652 if (normalize(thisray.rdir) == 0.0)
653 return(0.0);
654 }
655
656 rayorigin(&thisray, NULL, PRIMARY, 1.0);
657
658 rayvalue(&thisray); /* trace ray */
659
660 copycolor(col, thisray.rcol); /* return color */
661
662 return(thisray.rt); /* return distance */
663 }
664
665
666 int
667 salvage(oldfile) /* salvage scanlines from killed program */
668 char *oldfile;
669 {
670 COLR *scanline;
671 FILE *fp;
672 int x, y;
673
674 if (oldfile == NULL)
675 goto gotzip;
676
677 if ((fp = fopen(oldfile, "r")) == NULL) {
678 sprintf(errmsg, "cannot open recover file \"%s\"", oldfile);
679 error(WARNING, errmsg);
680 goto gotzip;
681 }
682 SET_FILE_BINARY(fp);
683 /* discard header */
684 getheader(fp, NULL, NULL);
685 /* get picture size */
686 if (!fscnresolu(&x, &y, fp)) {
687 sprintf(errmsg, "bad recover file \"%s\" - not removed",
688 oldfile);
689 error(WARNING, errmsg);
690 fclose(fp);
691 goto gotzip;
692 }
693
694 if (x != hres || y != vres) {
695 sprintf(errmsg, "resolution mismatch in recover file \"%s\"",
696 oldfile);
697 error(USER, errmsg);
698 }
699
700 scanline = (COLR *)malloc(hres*sizeof(COLR));
701 if (scanline == NULL)
702 error(SYSTEM, "out of memory in salvage");
703 for (y = 0; y < vres; y++) {
704 if (freadcolrs(scanline, hres, fp) < 0)
705 break;
706 if (fwritecolrs(scanline, hres, stdout) < 0)
707 goto writerr;
708 }
709 if (fflush(stdout) == EOF)
710 goto writerr;
711 free((void *)scanline);
712 fclose(fp);
713 unlink(oldfile);
714 return(y);
715 gotzip:
716 if (fflush(stdout) == EOF)
717 error(SYSTEM, "error writing picture header");
718 return(0);
719 writerr:
720 sprintf(errmsg, "write error during recovery of \"%s\"", oldfile);
721 error(SYSTEM, errmsg);
722 }
723
724
725 int
726 pixnumber(x, y, xres, yres) /* compute pixel index (brushed) */
727 register int x, y;
728 int xres, yres;
729 {
730 x -= y;
731 while (x < 0)
732 x += xres;
733 return((((x>>2)*yres + y) << 2) + (x & 3));
734 }