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root/radiance/ray/src/rt/ambient.c
Revision: 2.26
Committed: Thu Apr 27 14:12:05 1995 UTC (29 years ago) by greg
Content type: text/plain
Branch: MAIN
Changes since 2.25: +183 -12 lines
Log Message:
added memory sorting to ambient caching module

File Contents

# Content
1 /* Copyright (c) 1993 Regents of the University of California */
2
3 #ifndef lint
4 static char SCCSid[] = "$SunId$ LBL";
5 #endif
6
7 /*
8 * ambient.c - routines dealing with ambient (inter-reflected) component.
9 */
10
11 #include "ray.h"
12
13 #include "octree.h"
14
15 #include "otypes.h"
16
17 #include "ambient.h"
18
19 #include "random.h"
20
21 #define OCTSCALE 0.5 /* ceil((valid rad.)/(cube size)) */
22
23 typedef struct ambtree {
24 AMBVAL *alist; /* ambient value list */
25 struct ambtree *kid; /* 8 child nodes */
26 } AMBTREE; /* ambient octree */
27
28 extern CUBE thescene; /* contains space boundaries */
29
30 extern char *shm_boundary; /* shared memory boundary */
31
32 #define MAXASET 511 /* maximum number of elements in ambient set */
33 OBJECT ambset[MAXASET+1]={0}; /* ambient include/exclude set */
34
35 double maxarad; /* maximum ambient radius */
36 double minarad; /* minimum ambient radius */
37
38 static AMBTREE atrunk; /* our ambient trunk node */
39
40 static FILE *ambfp = NULL; /* ambient file pointer */
41 static int nunflshed = 0; /* number of unflushed ambient values */
42
43 #ifndef SORT_THRESH
44 #ifdef BIGMEM
45 #define SORT_THRESH (6*(1L<<20)/sizeof(AMBVAL))
46 #else
47 #define SORT_THRESH (2*(1L<<20)/sizeof(AMBVAL))
48 #endif
49 #endif
50 #ifndef SORT_INTVL
51 #define SORT_INTVL (SORT_THRESH*2)
52 #endif
53
54 static long ambclock = 0; /* ambient access clock */
55 static int nambvals = 0; /* number of stored ambient values */
56 static long lastsort = 0; /* time of last value sort */
57 static long sortintvl = SORT_INTVL; /* time until next sort */
58
59 #define MAXACLOCK (1L<<30) /* clock turnover value */
60 #define tracktime (shm_boundary == NULL || ambfp == NULL)
61 #define need2sort (ambclock > lastsort+sortintvl && \
62 nambvals > SORT_THRESH)
63
64 #define AMBFLUSH (BUFSIZ/AMBVALSIZ)
65
66 #define newambval() (AMBVAL *)bmalloc(sizeof(AMBVAL))
67
68 extern long ftell(), lseek();
69 static int initambfile(), avsave(), avinsert(), sortambvals();
70 static AMBVAL *avstore();
71 #ifdef F_SETLKW
72 static aflock();
73 #endif
74
75
76 setambres(ar) /* set ambient resolution */
77 int ar;
78 {
79 ambres = ar < 0 ? 0 : ar; /* may be done already */
80 /* set min & max radii */
81 if (ar <= 0) {
82 minarad = 0;
83 maxarad = thescene.cusize / 2.0;
84 } else {
85 minarad = thescene.cusize / ar;
86 maxarad = 16 * minarad; /* heuristic */
87 if (maxarad > thescene.cusize / 2.0)
88 maxarad = thescene.cusize / 2.0;
89 }
90 if (minarad <= FTINY)
91 minarad = 10*FTINY;
92 if (maxarad <= minarad)
93 maxarad = 64 * minarad;
94 }
95
96
97 setambacc(newa) /* set ambient accuracy */
98 double newa;
99 {
100 static double oldambacc = -1.0;
101
102 ambacc = newa < 0.0 ? 0.0 : newa; /* may be done already */
103 if (oldambacc < -FTINY)
104 oldambacc = ambacc; /* do nothing first call */
105 if (fabs(newa - oldambacc) < 0.01)
106 return; /* insignificant -- don't bother */
107 if (ambacc <= FTINY)
108 return; /* cannot build new tree */
109 /* else need to rebuild tree */
110 sortambvals(1);
111 oldambacc = ambacc; /* remeber setting for next call */
112 }
113
114
115 setambient(afile) /* initialize calculation */
116 char *afile;
117 {
118 long headlen;
119 AMBVAL amb;
120 /* init ambient limits */
121 setambres(ambres);
122 setambacc(ambacc);
123 if (afile == NULL)
124 return;
125 if (ambacc <= FTINY) {
126 sprintf(errmsg, "zero ambient accuracy so \"%s\" not opened",
127 afile);
128 error(WARNING, errmsg);
129 return;
130 }
131 /* open ambient file */
132 if ((ambfp = fopen(afile, "r+")) != NULL) {
133 initambfile(0);
134 headlen = ftell(ambfp);
135 while (readambval(&amb, ambfp))
136 avinsert(avstore(&amb));
137 /* align */
138 fseek(ambfp, -((ftell(ambfp)-headlen)%AMBVALSIZ), 1);
139 } else if ((ambfp = fopen(afile, "w+")) != NULL)
140 initambfile(1);
141 else {
142 sprintf(errmsg, "cannot open ambient file \"%s\"", afile);
143 error(SYSTEM, errmsg);
144 }
145 nunflshed++; /* lie */
146 ambsync();
147 }
148
149
150 ambnotify(obj) /* record new modifier */
151 OBJECT obj;
152 {
153 static int hitlimit = 0;
154 register OBJREC *o = objptr(obj);
155 register char **amblp;
156
157 if (hitlimit || !ismodifier(o->otype))
158 return;
159 for (amblp = amblist; *amblp != NULL; amblp++)
160 if (!strcmp(o->oname, *amblp)) {
161 if (ambset[0] >= MAXASET) {
162 error(WARNING, "too many modifiers in ambient list");
163 hitlimit++;
164 return; /* should this be fatal? */
165 }
166 insertelem(ambset, obj);
167 return;
168 }
169 }
170
171
172 ambient(acol, r) /* compute ambient component for ray */
173 COLOR acol;
174 register RAY *r;
175 {
176 static int rdepth = 0; /* ambient recursion */
177 double d;
178
179 if (ambdiv <= 0) /* no ambient calculation */
180 goto dumbamb;
181 /* check number of bounces */
182 if (rdepth >= ambounce)
183 goto dumbamb;
184 /* check ambient list */
185 if (ambincl != -1 && r->ro != NULL &&
186 ambincl != inset(ambset, r->ro->omod))
187 goto dumbamb;
188
189 if (ambacc <= FTINY) { /* no ambient storage */
190 rdepth++;
191 d = doambient(acol, r, r->rweight, NULL, NULL);
192 rdepth--;
193 if (d == 0.0)
194 goto dumbamb;
195 return;
196 }
197 /* get ambient value */
198 if (need2sort)
199 sortambvals(0);
200 setcolor(acol, 0.0, 0.0, 0.0);
201 d = sumambient(acol, r, rdepth,
202 &atrunk, thescene.cuorg, thescene.cusize);
203 if (d > FTINY)
204 scalecolor(acol, 1.0/d);
205 else {
206 d = makeambient(acol, r, rdepth++);
207 rdepth--;
208 }
209 if (d > FTINY)
210 return;
211 dumbamb: /* return global value */
212 copycolor(acol, ambval);
213 }
214
215
216 double
217 sumambient(acol, r, al, at, c0, s) /* get interpolated ambient value */
218 COLOR acol;
219 register RAY *r;
220 int al;
221 AMBTREE *at;
222 FVECT c0;
223 double s;
224 {
225 double d, e1, e2, wt, wsum;
226 COLOR ct;
227 FVECT ck0;
228 int i;
229 register int j;
230 register AMBVAL *av;
231 /* do this node */
232 wsum = 0.0;
233 for (av = at->alist; av != NULL; av = av->next) {
234 if (tracktime)
235 av->latick = ambclock++;
236 /*
237 * Ambient level test.
238 */
239 if (av->lvl > al) /* list sorted, so this works */
240 break;
241 if (av->weight < r->rweight-FTINY)
242 continue;
243 /*
244 * Ambient radius test.
245 */
246 e1 = 0.0;
247 for (j = 0; j < 3; j++) {
248 d = av->pos[j] - r->rop[j];
249 e1 += d * d;
250 }
251 e1 /= av->rad * av->rad;
252 if (e1 > ambacc*ambacc*1.21)
253 continue;
254 /*
255 * Normal direction test.
256 */
257 e2 = (1.0 - DOT(av->dir, r->ron)) * r->rweight;
258 if (e2 < 0.0) e2 = 0.0;
259 if (e1 + e2 > ambacc*ambacc*1.21)
260 continue;
261 /*
262 * Ray behind test.
263 */
264 d = 0.0;
265 for (j = 0; j < 3; j++)
266 d += (r->rop[j] - av->pos[j]) *
267 (av->dir[j] + r->ron[j]);
268 if (d*0.5 < -minarad*ambacc-.001)
269 continue;
270 /*
271 * Jittering final test reduces image artifacts.
272 */
273 wt = sqrt(e1) + sqrt(e2);
274 wt *= .9 + .2*urand(9015+samplendx);
275 if (wt > ambacc)
276 continue;
277 if (wt <= 1e-3)
278 wt = 1e3;
279 else
280 wt = 1.0 / wt;
281 wsum += wt;
282 extambient(ct, av, r->rop, r->ron);
283 scalecolor(ct, wt);
284 addcolor(acol, ct);
285 }
286 if (at->kid == NULL)
287 return(wsum);
288 /* do children */
289 s *= 0.5;
290 for (i = 0; i < 8; i++) {
291 for (j = 0; j < 3; j++) {
292 ck0[j] = c0[j];
293 if (1<<j & i)
294 ck0[j] += s;
295 if (r->rop[j] < ck0[j] - OCTSCALE*s)
296 break;
297 if (r->rop[j] > ck0[j] + (1.0+OCTSCALE)*s)
298 break;
299 }
300 if (j == 3)
301 wsum += sumambient(acol, r, al, at->kid+i, ck0, s);
302 }
303 return(wsum);
304 }
305
306
307 double
308 makeambient(acol, r, al) /* make a new ambient value */
309 COLOR acol;
310 register RAY *r;
311 int al;
312 {
313 AMBVAL amb;
314 FVECT gp, gd;
315 /* compute weight */
316 amb.weight = pow(AVGREFL, (double)al);
317 if (r->rweight < 0.2*amb.weight) /* heuristic */
318 amb.weight = r->rweight;
319 /* compute ambient */
320 amb.rad = doambient(acol, r, amb.weight, gp, gd);
321 if (amb.rad == 0.0)
322 return(0.0);
323 /* store it */
324 VCOPY(amb.pos, r->rop);
325 VCOPY(amb.dir, r->ron);
326 amb.lvl = al;
327 copycolor(amb.val, acol);
328 VCOPY(amb.gpos, gp);
329 VCOPY(amb.gdir, gd);
330 /* insert into tree */
331 avsave(&amb); /* and save to file */
332 return(amb.rad);
333 }
334
335
336 extambient(cr, ap, pv, nv) /* extrapolate value at pv, nv */
337 COLOR cr;
338 register AMBVAL *ap;
339 FVECT pv, nv;
340 {
341 FVECT v1, v2;
342 register int i;
343 double d;
344
345 d = 1.0; /* zeroeth order */
346 /* gradient due to translation */
347 for (i = 0; i < 3; i++)
348 d += ap->gpos[i]*(pv[i]-ap->pos[i]);
349 /* gradient due to rotation */
350 VCOPY(v1, ap->dir);
351 fcross(v2, v1, nv);
352 d += DOT(ap->gdir, v2);
353 if (d <= 0.0) {
354 setcolor(cr, 0.0, 0.0, 0.0);
355 return;
356 }
357 copycolor(cr, ap->val);
358 scalecolor(cr, d);
359 }
360
361
362 static
363 initambfile(creat) /* initialize ambient file */
364 int creat;
365 {
366 extern char *progname, *octname, VersionID[];
367
368 #ifdef F_SETLKW
369 aflock(creat ? F_WRLCK : F_RDLCK);
370 #endif
371 #ifdef MSDOS
372 setmode(fileno(ambfp), O_BINARY);
373 #endif
374 setbuf(ambfp, bmalloc(BUFSIZ+8));
375 if (creat) { /* new file */
376 newheader("RADIANCE", ambfp);
377 fprintf(ambfp, "%s -av %g %g %g -ab %d -aa %g ",
378 progname, colval(ambval,RED),
379 colval(ambval,GRN), colval(ambval,BLU),
380 ambounce, ambacc);
381 fprintf(ambfp, "-ad %d -as %d -ar %d %s\n",
382 ambdiv, ambssamp, ambres,
383 octname==NULL ? "" : octname);
384 fprintf(ambfp, "SOFTWARE= %s\n", VersionID);
385 fputformat(AMBFMT, ambfp);
386 putc('\n', ambfp);
387 putambmagic(ambfp);
388 } else if (checkheader(ambfp, AMBFMT, NULL) < 0 || !hasambmagic(ambfp))
389 error(USER, "bad ambient file");
390 }
391
392
393 static
394 avsave(av) /* insert and save an ambient value */
395 AMBVAL *av;
396 {
397 avinsert(avstore(av));
398 if (ambfp == NULL)
399 return;
400 if (writambval(av, ambfp) < 0)
401 goto writerr;
402 if (++nunflshed >= AMBFLUSH)
403 if (ambsync() == EOF)
404 goto writerr;
405 return;
406 writerr:
407 error(SYSTEM, "error writing ambient file");
408 }
409
410
411 static AMBVAL *
412 avstore(aval) /* allocate memory and store aval */
413 register AMBVAL *aval;
414 {
415 register AMBVAL *av;
416
417 if ((av = newambval()) == NULL)
418 error(SYSTEM, "out of memory in avstore");
419 copystruct(av, aval);
420 av->latick = ambclock;
421 av->next = NULL;
422 nambvals++;
423 return(av);
424 }
425
426
427 #define ATALLOCSZ 512 /* #/8 trees to allocate at once */
428
429 static AMBTREE *atfreelist = NULL; /* free ambient tree structures */
430
431
432 static
433 AMBTREE *
434 newambtree() /* allocate 8 ambient tree structs */
435 {
436 register AMBTREE *atp, *upperlim;
437
438 if (atfreelist == NULL) { /* get more nodes */
439 atfreelist = (AMBTREE *)bmalloc(ATALLOCSZ*8*sizeof(AMBTREE));
440 if (atfreelist == NULL)
441 return(NULL);
442 /* link new free list */
443 upperlim = atfreelist + 8*(ATALLOCSZ-1);
444 for (atp = atfreelist; atp < upperlim; atp += 8)
445 atp->kid = atp + 8;
446 atp->kid = NULL;
447 }
448 atp = atfreelist;
449 atfreelist = atp->kid;
450 bzero((char *)atp, 8*sizeof(AMBTREE));
451 return(atp);
452 }
453
454
455 static
456 freeambtree(atp) /* free 8 ambient tree structs */
457 AMBTREE *atp;
458 {
459 atp->kid = atfreelist;
460 atfreelist = atp;
461 }
462
463
464 static
465 avinsert(av) /* insert ambient value in our tree */
466 register AMBVAL *av;
467 {
468 register AMBTREE *at;
469 register AMBVAL *ap;
470 AMBVAL avh;
471 FVECT ck0;
472 double s;
473 int branch;
474 register int i;
475
476 if (av->rad <= FTINY)
477 error(CONSISTENCY, "zero ambient radius in avinsert");
478 at = &atrunk;
479 VCOPY(ck0, thescene.cuorg);
480 s = thescene.cusize;
481 while (s*(OCTSCALE/2) > av->rad*ambacc) {
482 if (at->kid == NULL)
483 if ((at->kid = newambtree()) == NULL)
484 error(SYSTEM, "out of memory in avinsert");
485 s *= 0.5;
486 branch = 0;
487 for (i = 0; i < 3; i++)
488 if (av->pos[i] > ck0[i] + s) {
489 ck0[i] += s;
490 branch |= 1 << i;
491 }
492 at = at->kid + branch;
493 }
494 avh.next = at->alist; /* order by increasing level */
495 for (ap = &avh; ap->next != NULL; ap = ap->next)
496 if (ap->next->lvl >= av->lvl)
497 break;
498 av->next = ap->next;
499 ap->next = av;
500 at->alist = avh.next;
501 }
502
503
504 static
505 unloadatree(at, f) /* unload an ambient value tree */
506 register AMBTREE *at;
507 int (*f)();
508 {
509 register AMBVAL *av;
510 register int i;
511 /* transfer values at this node */
512 for (av = at->alist; av != NULL; av = at->alist) {
513 at->alist = av->next;
514 (*f)(av);
515 }
516 if (at->kid == NULL)
517 return;
518 for (i = 0; i < 8; i++) /* transfer and free children */
519 unloadatree(at->kid+i, f);
520 freeambtree(at->kid);
521 at->kid = NULL;
522 }
523
524
525 static AMBVAL **avlist1, **avlist2; /* ambient value lists for sorting */
526 static int i_avlist; /* index for lists */
527
528
529 static
530 av2list(av)
531 AMBVAL *av;
532 {
533 if (i_avlist >= nambvals)
534 error(CONSISTENCY, "too many ambient values in av2list1");
535 avlist1[i_avlist] = avlist2[i_avlist] = av;
536 i_avlist++;
537 }
538
539
540 static int
541 alatcmp(avp1, avp2) /* compare ambient values for MRA */
542 AMBVAL **avp1, **avp2;
543 {
544 return((**avp2).latick - (**avp1).latick);
545 }
546
547
548 static int
549 aposcmp(avp1, avp2) /* compare ambient value positions */
550 AMBVAL **avp1, **avp2;
551 {
552 return(*avp1 - *avp2);
553 }
554
555
556 static
557 sortambvals(always) /* resort ambient values */
558 int always;
559 {
560 AMBTREE oldatrunk;
561 AMBVAL tav, *tap, *pnext;
562 register int i, j;
563 /*
564 * The idea here is to minimize memory thrashing
565 * in VM systems by improving reference locality.
566 * We do this by periodically sorting our stored ambient
567 * values in memory in order of most recently to least
568 * recently accessed. This ordering was chosen so that new
569 * ambient values (which tend to be less important) go into
570 * higher memory with the infrequently accessed values.
571 * Since we expect our values to need sorting less
572 * frequently as the process continues, we double our
573 * waiting interval after each call.
574 * This routine is also called by setambacc() with
575 * the "always" parameter set to 1 so that the ambient
576 * tree will be rebuilt with the new accuracy parameter.
577 */
578 if (tracktime) {
579 avlist1 = (AMBVAL **)malloc(nambvals*sizeof(AMBVAL *));
580 avlist2 = (AMBVAL **)malloc(nambvals*sizeof(AMBVAL *));
581 } else
582 avlist1 = avlist2 = NULL;
583 if (avlist2 == NULL) { /* rebuild tree? */
584 if (avlist1 != NULL)
585 free((char *)avlist1);
586 if (!always)
587 return;
588 copystruct(&oldatrunk, &atrunk);
589 atrunk.alist = NULL;
590 atrunk.kid = NULL;
591 unloadatree(&oldatrunk, avinsert);
592 } else { /* sort memory by last access time */
593 i_avlist = 0;
594 unloadatree(&atrunk, av2list); /* empty current tree */
595 /*
596 * Sorting memory is tricky because it isn't contiguous.
597 * We have to sort an array of pointers by MRA and also
598 * by memory position. We then copy values in "loops"
599 * to minimize memory hits. Nevertheless, we will visit
600 * everyone at least once, and this is an expensive process
601 * when we're thrashing, which is when we need to do it.
602 */
603 qsort((char *)avlist1, nambvals, sizeof(AMBVAL *), alatcmp);
604 qsort((char *)avlist2, nambvals, sizeof(AMBVAL *), aposcmp);
605 for (i = 0; i < nambvals; i++) {
606 if (avlist1[i] == NULL || avlist1[i] == avlist2[i])
607 continue;
608 tap = avlist2[i];
609 copystruct(&tav, tap);
610 for (j = i; (pnext = avlist1[j]) != tap;
611 j = (AMBVAL **)bsearch((char *)&pnext,
612 (char *)(avlist2+i),nambvals-i,
613 sizeof(AMBVAL *),aposcmp) -
614 avlist2) {
615 copystruct(avlist2[j], pnext);
616 avinsert(avlist2[j]);
617 avlist1[j] = NULL;
618 }
619 copystruct(avlist2[j], &tav);
620 avinsert(avlist2[j]);
621 avlist1[j] = NULL;
622 }
623 free((char *)avlist1);
624 free((char *)avlist2);
625 if (sortintvl < MAXACLOCK/4)
626 sortintvl <<= 1; /* wait twice as long next */
627 }
628 if (ambclock >= MAXACLOCK)
629 ambclock = MAXACLOCK/2;
630 lastsort = ambclock;
631 }
632
633
634 #ifdef F_SETLKW
635
636 static
637 aflock(typ) /* lock/unlock ambient file */
638 int typ;
639 {
640 static struct flock fls; /* static so initialized to zeroes */
641
642 fls.l_type = typ;
643 if (fcntl(fileno(ambfp), F_SETLKW, &fls) < 0)
644 error(SYSTEM, "cannot (un)lock ambient file");
645 }
646
647
648 int
649 ambsync() /* synchronize ambient file */
650 {
651 static FILE *ambinp = NULL;
652 static long lastpos = -1;
653 long flen;
654 AMBVAL avs;
655 register int n;
656
657 if (nunflshed == 0)
658 return(0);
659 if (lastpos < 0) /* initializing (locked in initambfile) */
660 goto syncend;
661 /* gain exclusive access */
662 aflock(F_WRLCK);
663 /* see if file has grown */
664 if ((flen = lseek(fileno(ambfp), 0L, 2)) < 0)
665 goto seekerr;
666 if (n = flen - lastpos) { /* file has grown */
667 if (ambinp == NULL) { /* use duplicate filedes */
668 ambinp = fdopen(dup(fileno(ambfp)), "r");
669 if (ambinp == NULL)
670 error(SYSTEM, "fdopen failed in ambsync");
671 }
672 if (fseek(ambinp, lastpos, 0) < 0)
673 goto seekerr;
674 while (n >= AMBVALSIZ) { /* load contributed values */
675 readambval(&avs, ambinp);
676 avinsert(avstore(&avs));
677 n -= AMBVALSIZ;
678 }
679 /*** seek always as safety measure
680 if (n) ***/ /* alignment */
681 if (lseek(fileno(ambfp), flen-n, 0) < 0)
682 goto seekerr;
683 }
684 #ifdef DEBUG
685 if (ambfp->_ptr - ambfp->_base != nunflshed*AMBVALSIZ) {
686 sprintf(errmsg, "ambient file buffer at %d rather than %d",
687 ambfp->_ptr - ambfp->_base,
688 nunflshed*AMBVALSIZ);
689 error(CONSISTENCY, errmsg);
690 }
691 #endif
692 syncend:
693 n = fflush(ambfp); /* calls write() at last */
694 if ((lastpos = lseek(fileno(ambfp), 0L, 1)) < 0)
695 goto seekerr;
696 aflock(F_UNLCK); /* release file */
697 nunflshed = 0;
698 return(n);
699 seekerr:
700 error(SYSTEM, "seek failed in ambsync");
701 }
702
703 #else
704
705 int
706 ambsync() /* flush ambient file */
707 {
708 if (nunflshed == 0)
709 return(0);
710 nunflshed = 0;
711 return(fflush(ambfp));
712 }
713
714 #endif