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root/radiance/ray/src/rt/ambient.c
Revision: 2.107
Committed: Sat Feb 16 00:09:53 2019 UTC (5 years, 3 months ago) by greg
Content type: text/plain
Branch: MAIN
Changes since 2.106: +2 -2 lines
Log Message:
Fixed infinite loop when setting aa to 0 within rvu

File Contents

# Content
1 static const char RCSid[] = "$Id: ambient.c,v 2.106 2018/11/08 00:54:07 greg Exp $";
2 /*
3 * ambient.c - routines dealing with ambient (inter-reflected) component.
4 *
5 * Declarations of external symbols in ambient.h
6 */
7
8 #include "copyright.h"
9
10 #include <string.h>
11
12 #include "platform.h"
13 #include "ray.h"
14 #include "otypes.h"
15 #include "otspecial.h"
16 #include "resolu.h"
17 #include "ambient.h"
18 #include "random.h"
19 #include "pmapamb.h"
20
21 #ifndef OCTSCALE
22 #define OCTSCALE 1.0 /* ceil((valid rad.)/(cube size)) */
23 #endif
24
25 extern char *shm_boundary; /* memory sharing boundary */
26
27 #ifndef MAXASET
28 #define MAXASET 4095 /* maximum number of elements in ambient set */
29 #endif
30 OBJECT ambset[MAXASET+1]={0}; /* ambient include/exclude set */
31
32 double maxarad; /* maximum ambient radius */
33 double minarad; /* minimum ambient radius */
34
35 static AMBTREE atrunk; /* our ambient trunk node */
36
37 static FILE *ambfp = NULL; /* ambient file pointer */
38 static int nunflshed = 0; /* number of unflushed ambient values */
39
40 #ifndef SORT_THRESH
41 #ifdef SMLMEM
42 #define SORT_THRESH ((16L<<20)/sizeof(AMBVAL))
43 #else
44 #define SORT_THRESH ((64L<<20)/sizeof(AMBVAL))
45 #endif
46 #endif
47 #ifndef SORT_INTVL
48 #define SORT_INTVL (SORT_THRESH<<1)
49 #endif
50 #ifndef MAX_SORT_INTVL
51 #define MAX_SORT_INTVL (SORT_INTVL<<6)
52 #endif
53
54
55 static double avsum = 0.; /* computed ambient value sum (log) */
56 static unsigned int navsum = 0; /* number of values in avsum */
57 static unsigned int nambvals = 0; /* total number of indirect values */
58 static unsigned int nambshare = 0; /* number of values from file */
59 static unsigned long ambclock = 0; /* ambient access clock */
60 static unsigned long lastsort = 0; /* time of last value sort */
61 static long sortintvl = SORT_INTVL; /* time until next sort */
62 static FILE *ambinp = NULL; /* auxiliary file for input */
63 static long lastpos = -1; /* last flush position */
64
65 #define MAXACLOCK (1L<<30) /* clock turnover value */
66 /*
67 * Track access times unless we are sharing ambient values
68 * through memory on a multiprocessor, when we want to avoid
69 * claiming our own memory (copy on write). Go ahead anyway
70 * if more than two thirds of our values are unshared.
71 * Compile with -Dtracktime=0 to turn this code off.
72 */
73 #ifndef tracktime
74 #define tracktime (shm_boundary == NULL || nambvals > 3*nambshare)
75 #endif
76
77 #define AMBFLUSH (BUFSIZ/AMBVALSIZ)
78
79 #define newambval() (AMBVAL *)malloc(sizeof(AMBVAL))
80
81 static void initambfile(int creat);
82 static void avsave(AMBVAL *av);
83 static AMBVAL *avstore(AMBVAL *aval);
84 static AMBTREE *newambtree(void);
85 static void freeambtree(AMBTREE *atp);
86
87 typedef void unloadtf_t(AMBVAL *);
88 static unloadtf_t avinsert;
89 static unloadtf_t av2list;
90 static unloadtf_t avfree;
91 static void unloadatree(AMBTREE *at, unloadtf_t *f);
92
93 static int aposcmp(const void *avp1, const void *avp2);
94 static int avlmemi(AMBVAL *avaddr);
95 static void sortambvals(int always);
96
97 #ifdef F_SETLKW
98 static void aflock(int typ);
99 #endif
100
101
102 void
103 setambres( /* set ambient resolution */
104 int ar
105 )
106 {
107 ambres = ar < 0 ? 0 : ar; /* may be done already */
108 /* set min & max radii */
109 if (ar <= 0) {
110 minarad = 0;
111 maxarad = thescene.cusize*0.2;
112 } else {
113 minarad = thescene.cusize / ar;
114 maxarad = 64.0 * minarad; /* heuristic */
115 if (maxarad > thescene.cusize*0.2)
116 maxarad = thescene.cusize*0.2;
117 }
118 if (minarad <= FTINY)
119 minarad = 10.0*FTINY;
120 if (maxarad <= minarad)
121 maxarad = 64.0 * minarad;
122 }
123
124
125 void
126 setambacc( /* set ambient accuracy */
127 double newa
128 )
129 {
130 static double olda; /* remember previous setting here */
131
132 newa *= (newa > 0);
133 if (fabs(newa - olda) >= .05*(newa + olda)) {
134 ambacc = newa;
135 if (ambacc > FTINY && nambvals > 0)
136 sortambvals(1); /* rebuild tree */
137 }
138 }
139
140
141 void
142 setambient(void) /* initialize calculation */
143 {
144 int readonly = 0;
145 long flen;
146 AMBVAL amb;
147 /* make sure we're fresh */
148 ambdone();
149 /* init ambient limits */
150 setambres(ambres);
151 setambacc(ambacc);
152 if (ambfile == NULL || !ambfile[0])
153 return;
154 if (ambacc <= FTINY) {
155 sprintf(errmsg, "zero ambient accuracy so \"%s\" not opened",
156 ambfile);
157 error(WARNING, errmsg);
158 return;
159 }
160 /* open ambient file */
161 if ((ambfp = fopen(ambfile, "r+")) == NULL)
162 readonly = (ambfp = fopen(ambfile, "r")) != NULL;
163 if (ambfp != NULL) {
164 initambfile(0); /* file exists */
165 lastpos = ftell(ambfp);
166 while (readambval(&amb, ambfp))
167 avstore(&amb);
168 nambshare = nambvals; /* share loaded values */
169 if (readonly) {
170 sprintf(errmsg,
171 "loaded %u values from read-only ambient file",
172 nambvals);
173 error(WARNING, errmsg);
174 fclose(ambfp); /* close file so no writes */
175 ambfp = NULL;
176 return; /* avoid ambsync() */
177 }
178 /* align file pointer */
179 lastpos += (long)nambvals*AMBVALSIZ;
180 flen = lseek(fileno(ambfp), (off_t)0, SEEK_END);
181 if (flen != lastpos) {
182 sprintf(errmsg,
183 "ignoring last %ld values in ambient file (corrupted)",
184 (flen - lastpos)/AMBVALSIZ);
185 error(WARNING, errmsg);
186 fseek(ambfp, lastpos, SEEK_SET);
187 ftruncate(fileno(ambfp), (off_t)lastpos);
188 }
189 } else if ((ambfp = fopen(ambfile, "w+")) != NULL) {
190 initambfile(1); /* else create new file */
191 fflush(ambfp);
192 lastpos = ftell(ambfp);
193 } else {
194 sprintf(errmsg, "cannot open ambient file \"%s\"", ambfile);
195 error(SYSTEM, errmsg);
196 }
197 #ifdef F_SETLKW
198 aflock(F_UNLCK); /* release file */
199 #endif
200 }
201
202
203 void
204 ambdone(void) /* close ambient file and free memory */
205 {
206 if (ambfp != NULL) { /* close ambient file */
207 ambsync();
208 fclose(ambfp);
209 ambfp = NULL;
210 if (ambinp != NULL) {
211 fclose(ambinp);
212 ambinp = NULL;
213 }
214 lastpos = -1;
215 }
216 /* free ambient tree */
217 unloadatree(&atrunk, avfree);
218 /* reset state variables */
219 avsum = 0.;
220 navsum = 0;
221 nambvals = 0;
222 nambshare = 0;
223 ambclock = 0;
224 lastsort = 0;
225 sortintvl = SORT_INTVL;
226 }
227
228
229 void
230 ambnotify( /* record new modifier */
231 OBJECT obj
232 )
233 {
234 static int hitlimit = 0;
235 OBJREC *o;
236 char **amblp;
237
238 if (obj == OVOID) { /* starting over */
239 ambset[0] = 0;
240 hitlimit = 0;
241 return;
242 }
243 o = objptr(obj);
244 if (hitlimit || !ismodifier(o->otype))
245 return;
246 for (amblp = amblist; *amblp != NULL; amblp++)
247 if (!strcmp(o->oname, *amblp)) {
248 if (ambset[0] >= MAXASET) {
249 error(WARNING, "too many modifiers in ambient list");
250 hitlimit++;
251 return; /* should this be fatal? */
252 }
253 insertelem(ambset, obj);
254 return;
255 }
256 }
257
258 /************ THE FOLLOWING ROUTINES DIFFER BETWEEN NEW & OLD ***************/
259
260 #ifndef OLDAMB
261
262 #define tfunc(lwr, x, upr) (((x)-(lwr))/((upr)-(lwr)))
263
264 static int plugaleak(RAY *r, AMBVAL *ap, FVECT anorm, double ang);
265 static double sumambient(COLOR acol, RAY *r, FVECT rn, int al,
266 AMBTREE *at, FVECT c0, double s);
267 static int makeambient(COLOR acol, RAY *r, FVECT rn, int al);
268 static int extambient(COLOR cr, AMBVAL *ap, FVECT pv, FVECT nv,
269 FVECT uvw[3]);
270
271 void
272 multambient( /* compute ambient component & multiply by coef. */
273 COLOR aval,
274 RAY *r,
275 FVECT nrm
276 )
277 {
278 static int rdepth = 0; /* ambient recursion */
279 COLOR acol, caustic;
280 int i, ok;
281 double d, l;
282
283 /* PMAP: Factor in ambient from photon map, if enabled and ray is
284 * ambient. Return as all ambient components accounted for, else
285 * continue. */
286 if (ambPmap(aval, r, rdepth))
287 return;
288
289 /* PMAP: Factor in specular-diffuse ambient (caustics) from photon
290 * map, if enabled and ray is primary, else caustic is zero. Continue
291 * with RADIANCE ambient calculation */
292 copycolor(caustic, aval);
293 ambPmapCaustic(caustic, r, rdepth);
294
295 if (ambdiv <= 0) /* no ambient calculation */
296 goto dumbamb;
297 /* check number of bounces */
298 if (rdepth >= ambounce)
299 goto dumbamb;
300 /* check ambient list */
301 if (ambincl != -1 && r->ro != NULL &&
302 ambincl != inset(ambset, r->ro->omod))
303 goto dumbamb;
304
305 if (ambacc <= FTINY) { /* no ambient storage */
306 FVECT uvd[2];
307 float dgrad[2], *dgp = NULL;
308
309 if (nrm != r->ron && DOT(nrm,r->ron) < 0.9999)
310 dgp = dgrad; /* compute rotational grad. */
311 copycolor(acol, aval);
312 rdepth++;
313 ok = doambient(acol, r, r->rweight,
314 uvd, NULL, NULL, dgp, NULL);
315 rdepth--;
316 if (!ok)
317 goto dumbamb;
318 if ((ok > 0) & (dgp != NULL)) { /* apply texture */
319 FVECT v1;
320 VCROSS(v1, r->ron, nrm);
321 d = 1.0;
322 for (i = 3; i--; )
323 d += v1[i] * (dgp[0]*uvd[0][i] + dgp[1]*uvd[1][i]);
324 if (d >= 0.05)
325 scalecolor(acol, d);
326 }
327 copycolor(aval, acol);
328
329 /* PMAP: add in caustic */
330 addcolor(aval, caustic);
331 return;
332 }
333
334 if (tracktime) /* sort to minimize thrashing */
335 sortambvals(0);
336 /* interpolate ambient value */
337 setcolor(acol, 0.0, 0.0, 0.0);
338 d = sumambient(acol, r, nrm, rdepth,
339 &atrunk, thescene.cuorg, thescene.cusize);
340
341 if (d > FTINY) {
342 d = 1.0/d;
343 scalecolor(acol, d);
344 multcolor(aval, acol);
345
346 /* PMAP: add in caustic */
347 addcolor(aval, caustic);
348 return;
349 }
350
351 rdepth++; /* need to cache new value */
352 ok = makeambient(acol, r, nrm, rdepth-1);
353 rdepth--;
354
355 if (ok) {
356 multcolor(aval, acol); /* computed new value */
357
358 /* PMAP: add in caustic */
359 addcolor(aval, caustic);
360 return;
361 }
362
363 dumbamb: /* return global value */
364 if ((ambvwt <= 0) | (navsum == 0)) {
365 multcolor(aval, ambval);
366
367 /* PMAP: add in caustic */
368 addcolor(aval, caustic);
369 return;
370 }
371
372 l = bright(ambval); /* average in computations */
373 if (l > FTINY) {
374 d = (log(l)*(double)ambvwt + avsum) /
375 (double)(ambvwt + navsum);
376 d = exp(d) / l;
377 scalecolor(aval, d);
378 multcolor(aval, ambval); /* apply color of ambval */
379 } else {
380 d = exp( avsum / (double)navsum );
381 scalecolor(aval, d); /* neutral color */
382 }
383 }
384
385
386 /* Plug a potential leak where ambient cache value is occluded */
387 static int
388 plugaleak(RAY *r, AMBVAL *ap, FVECT anorm, double ang)
389 {
390 const double cost70sq = 0.1169778; /* cos(70deg)^2 */
391 RAY rtst;
392 FVECT vdif;
393 double normdot, ndotd, nadotd;
394 double a, b, c, t[2];
395
396 ang += 2.*PI*(ang < 0); /* check direction flags */
397 if ( !(ap->corral>>(int)(ang*(16./PI)) & 1) )
398 return(0);
399 /*
400 * Generate test ray, targeting 20 degrees above sample point plane
401 * along surface normal from cache position. This should be high
402 * enough to miss local geometry we don't really care about.
403 */
404 VSUB(vdif, ap->pos, r->rop);
405 normdot = DOT(anorm, r->ron);
406 ndotd = DOT(vdif, r->ron);
407 nadotd = DOT(vdif, anorm);
408 a = normdot*normdot - cost70sq;
409 b = 2.0*(normdot*ndotd - nadotd*cost70sq);
410 c = ndotd*ndotd - DOT(vdif,vdif)*cost70sq;
411 if (quadratic(t, a, b, c) != 2)
412 return(1); /* should rarely happen */
413 if (t[1] <= FTINY)
414 return(0); /* should fail behind test */
415 rayorigin(&rtst, SHADOW, r, NULL);
416 VSUM(rtst.rdir, vdif, anorm, t[1]); /* further dist. > plane */
417 rtst.rmax = normalize(rtst.rdir); /* short ray test */
418 while (localhit(&rtst, &thescene)) { /* check for occluder */
419 OBJREC *m = findmaterial(rtst.ro);
420 if (m != NULL && !istransp(m->otype) && !isBSDFproxy(m) &&
421 (rtst.clipset == NULL ||
422 !inset(rtst.clipset, rtst.ro->omod)))
423 return(1); /* plug light leak */
424 VCOPY(rtst.rorg, rtst.rop); /* skip invisible surface */
425 rtst.rmax -= rtst.rot;
426 rayclear(&rtst);
427 }
428 return(0); /* seems we're OK */
429 }
430
431
432 static double
433 sumambient( /* get interpolated ambient value */
434 COLOR acol,
435 RAY *r,
436 FVECT rn,
437 int al,
438 AMBTREE *at,
439 FVECT c0,
440 double s
441 )
442 { /* initial limit is 10 degrees plus ambacc radians */
443 const double minangle = 10.0 * PI/180.;
444 double maxangle = minangle + ambacc;
445 double wsum = 0.0;
446 FVECT ck0;
447 int i, j;
448 AMBVAL *av;
449
450 if (at->kid != NULL) { /* sum children first */
451 s *= 0.5;
452 for (i = 0; i < 8; i++) {
453 for (j = 0; j < 3; j++) {
454 ck0[j] = c0[j];
455 if (1<<j & i)
456 ck0[j] += s;
457 if (r->rop[j] < ck0[j] - OCTSCALE*s)
458 break;
459 if (r->rop[j] > ck0[j] + (1.0+OCTSCALE)*s)
460 break;
461 }
462 if (j == 3)
463 wsum += sumambient(acol, r, rn, al,
464 at->kid+i, ck0, s);
465 }
466 /* good enough? */
467 if (wsum >= 0.05 && s > minarad*10.0)
468 return(wsum);
469 }
470 /* adjust maximum angle */
471 if (at->alist != NULL && (at->alist->lvl <= al) & (r->rweight < 0.6))
472 maxangle = (maxangle - PI/2.)*pow(r->rweight,0.13) + PI/2.;
473 /* sum this node */
474 for (av = at->alist; av != NULL; av = av->next) {
475 double u, v, d, delta_r2, delta_t2;
476 COLOR ct;
477 FVECT uvw[3];
478 /* record access */
479 if (tracktime)
480 av->latick = ambclock;
481 /*
482 * Ambient level test
483 */
484 if (av->lvl > al || /* list sorted, so this works */
485 (av->lvl == al) & (av->weight < 0.9*r->rweight))
486 break;
487 /*
488 * Direction test using unperturbed normal
489 */
490 decodedir(uvw[2], av->ndir);
491 d = DOT(uvw[2], r->ron);
492 if (d <= 0.0) /* >= 90 degrees */
493 continue;
494 delta_r2 = 2.0 - 2.0*d; /* approx. radians^2 */
495 if (delta_r2 >= maxangle*maxangle)
496 continue;
497 /*
498 * Modified ray behind test
499 */
500 VSUB(ck0, r->rop, av->pos);
501 d = DOT(ck0, uvw[2]);
502 if (d < -minarad*ambacc-.001)
503 continue;
504 d /= av->rad[0];
505 delta_t2 = d*d;
506 if (delta_t2 >= ambacc*ambacc)
507 continue;
508 /*
509 * Elliptical radii test based on Hessian
510 */
511 decodedir(uvw[0], av->udir);
512 VCROSS(uvw[1], uvw[2], uvw[0]);
513 d = (u = DOT(ck0, uvw[0])) / av->rad[0];
514 delta_t2 += d*d;
515 d = (v = DOT(ck0, uvw[1])) / av->rad[1];
516 delta_t2 += d*d;
517 if (delta_t2 >= ambacc*ambacc)
518 continue;
519 /*
520 * Test for potential light leak
521 */
522 if (av->corral && plugaleak(r, av, uvw[2], atan2a(v,u)))
523 continue;
524 /*
525 * Extrapolate value and compute final weight (hat function)
526 */
527 if (!extambient(ct, av, r->rop, rn, uvw))
528 continue;
529 d = tfunc(maxangle, sqrt(delta_r2), 0.0) *
530 tfunc(ambacc, sqrt(delta_t2), 0.0);
531 scalecolor(ct, d);
532 addcolor(acol, ct);
533 wsum += d;
534 }
535 return(wsum);
536 }
537
538
539 static int
540 makeambient( /* make a new ambient value for storage */
541 COLOR acol,
542 RAY *r,
543 FVECT rn,
544 int al
545 )
546 {
547 AMBVAL amb;
548 FVECT uvw[3];
549 int i;
550
551 amb.weight = 1.0; /* compute weight */
552 for (i = al; i-- > 0; )
553 amb.weight *= AVGREFL;
554 if (r->rweight < 0.1*amb.weight) /* heuristic override */
555 amb.weight = 1.25*r->rweight;
556 setcolor(acol, AVGREFL, AVGREFL, AVGREFL);
557 /* compute ambient */
558 i = doambient(acol, r, amb.weight,
559 uvw, amb.rad, amb.gpos, amb.gdir, &amb.corral);
560 scalecolor(acol, 1./AVGREFL); /* undo assumed reflectance */
561 if (i <= 0 || amb.rad[0] <= FTINY) /* no Hessian or zero radius */
562 return(i);
563 /* store value */
564 VCOPY(amb.pos, r->rop);
565 amb.ndir = encodedir(r->ron);
566 amb.udir = encodedir(uvw[0]);
567 amb.lvl = al;
568 copycolor(amb.val, acol);
569 /* insert into tree */
570 avsave(&amb); /* and save to file */
571 if (rn != r->ron) { /* texture */
572 VCOPY(uvw[2], r->ron);
573 extambient(acol, &amb, r->rop, rn, uvw);
574 }
575 return(1);
576 }
577
578
579 static int
580 extambient( /* extrapolate value at pv, nv */
581 COLOR cr,
582 AMBVAL *ap,
583 FVECT pv,
584 FVECT nv,
585 FVECT uvw[3]
586 )
587 {
588 const double min_d = 0.05;
589 static FVECT my_uvw[3];
590 FVECT v1;
591 int i;
592 double d = 1.0; /* zeroeth order */
593
594 if (uvw == NULL) { /* need local coordinates? */
595 decodedir(my_uvw[2], ap->ndir);
596 decodedir(my_uvw[0], ap->udir);
597 VCROSS(my_uvw[1], my_uvw[2], my_uvw[0]);
598 uvw = my_uvw;
599 }
600 for (i = 3; i--; ) /* gradient due to translation */
601 d += (pv[i] - ap->pos[i]) *
602 (ap->gpos[0]*uvw[0][i] + ap->gpos[1]*uvw[1][i]);
603
604 VCROSS(v1, uvw[2], nv); /* gradient due to rotation */
605 for (i = 3; i--; )
606 d += v1[i] * (ap->gdir[0]*uvw[0][i] + ap->gdir[1]*uvw[1][i]);
607
608 if (d < min_d) /* should not use if we can avoid it */
609 d = min_d;
610 copycolor(cr, ap->val);
611 scalecolor(cr, d);
612 return(d > min_d);
613 }
614
615
616 static void
617 avinsert( /* insert ambient value in our tree */
618 AMBVAL *av
619 )
620 {
621 AMBTREE *at;
622 AMBVAL *ap;
623 AMBVAL avh;
624 FVECT ck0;
625 double s;
626 int branch;
627 int i;
628
629 if (av->rad[0] <= FTINY)
630 error(CONSISTENCY, "zero ambient radius in avinsert");
631 at = &atrunk;
632 VCOPY(ck0, thescene.cuorg);
633 s = thescene.cusize;
634 while (s*(OCTSCALE/2) > av->rad[1]*ambacc) {
635 if (at->kid == NULL)
636 if ((at->kid = newambtree()) == NULL)
637 error(SYSTEM, "out of memory in avinsert");
638 s *= 0.5;
639 branch = 0;
640 for (i = 0; i < 3; i++)
641 if (av->pos[i] > ck0[i] + s) {
642 ck0[i] += s;
643 branch |= 1 << i;
644 }
645 at = at->kid + branch;
646 }
647 avh.next = at->alist; /* order by increasing level */
648 for (ap = &avh; ap->next != NULL; ap = ap->next)
649 if ( ap->next->lvl > av->lvl ||
650 (ap->next->lvl == av->lvl) &
651 (ap->next->weight <= av->weight) )
652 break;
653 av->next = ap->next;
654 ap->next = (AMBVAL*)av;
655 at->alist = avh.next;
656 }
657
658
659 #else /* ! NEWAMB */
660
661 static double sumambient(COLOR acol, RAY *r, FVECT rn, int al,
662 AMBTREE *at, FVECT c0, double s);
663 static double makeambient(COLOR acol, RAY *r, FVECT rn, int al);
664 static void extambient(COLOR cr, AMBVAL *ap, FVECT pv, FVECT nv);
665
666
667 void
668 multambient( /* compute ambient component & multiply by coef. */
669 COLOR aval,
670 RAY *r,
671 FVECT nrm
672 )
673 {
674 static int rdepth = 0; /* ambient recursion */
675 COLOR acol, caustic;
676 double d, l;
677
678 /* PMAP: Factor in ambient from global photon map (if enabled) and return
679 * as all ambient components accounted for */
680 if (ambPmap(aval, r, rdepth))
681 return;
682
683 /* PMAP: Otherwise factor in ambient from caustic photon map
684 * (ambPmapCaustic() returns zero if caustic photons disabled) and
685 * continue with RADIANCE ambient calculation */
686 copycolor(caustic, aval);
687 ambPmapCaustic(caustic, r, rdepth);
688
689 if (ambdiv <= 0) /* no ambient calculation */
690 goto dumbamb;
691 /* check number of bounces */
692 if (rdepth >= ambounce)
693 goto dumbamb;
694 /* check ambient list */
695 if (ambincl != -1 && r->ro != NULL &&
696 ambincl != inset(ambset, r->ro->omod))
697 goto dumbamb;
698
699 if (ambacc <= FTINY) { /* no ambient storage */
700 copycolor(acol, aval);
701 rdepth++;
702 d = doambient(acol, r, r->rweight, NULL, NULL);
703 rdepth--;
704 if (d <= FTINY)
705 goto dumbamb;
706 copycolor(aval, acol);
707
708 /* PMAP: add in caustic */
709 addcolor(aval, caustic);
710 return;
711 }
712
713 if (tracktime) /* sort to minimize thrashing */
714 sortambvals(0);
715 /* interpolate ambient value */
716 setcolor(acol, 0.0, 0.0, 0.0);
717 d = sumambient(acol, r, nrm, rdepth,
718 &atrunk, thescene.cuorg, thescene.cusize);
719
720 if (d > FTINY) {
721 d = 1.0/d;
722 scalecolor(acol, d);
723 multcolor(aval, acol);
724
725 /* PMAP: add in caustic */
726 addcolor(aval, caustic);
727 return;
728 }
729
730 rdepth++; /* need to cache new value */
731 d = makeambient(acol, r, nrm, rdepth-1);
732 rdepth--;
733
734 if (d > FTINY) {
735 multcolor(aval, acol); /* got new value */
736
737 /* PMAP: add in caustic */
738 addcolor(aval, caustic);
739 return;
740 }
741
742 dumbamb: /* return global value */
743 if ((ambvwt <= 0) | (navsum == 0)) {
744 multcolor(aval, ambval);
745
746 /* PMAP: add in caustic */
747 addcolor(aval, caustic);
748 return;
749 }
750
751 l = bright(ambval); /* average in computations */
752 if (l > FTINY) {
753 d = (log(l)*(double)ambvwt + avsum) /
754 (double)(ambvwt + navsum);
755 d = exp(d) / l;
756 scalecolor(aval, d);
757 multcolor(aval, ambval); /* apply color of ambval */
758 } else {
759 d = exp( avsum / (double)navsum );
760 scalecolor(aval, d); /* neutral color */
761 }
762 }
763
764
765 static double
766 sumambient( /* get interpolated ambient value */
767 COLOR acol,
768 RAY *r,
769 FVECT rn,
770 int al,
771 AMBTREE *at,
772 FVECT c0,
773 double s
774 )
775 {
776 double d, e1, e2, wt, wsum;
777 COLOR ct;
778 FVECT ck0;
779 int i;
780 int j;
781 AMBVAL *av;
782
783 wsum = 0.0;
784 /* do this node */
785 for (av = at->alist; av != NULL; av = av->next) {
786 double rn_dot = -2.0;
787 if (tracktime)
788 av->latick = ambclock;
789 /*
790 * Ambient level test.
791 */
792 if (av->lvl > al || /* list sorted, so this works */
793 (av->lvl == al) & (av->weight < 0.9*r->rweight))
794 break;
795 /*
796 * Ambient radius test.
797 */
798 VSUB(ck0, av->pos, r->rop);
799 e1 = DOT(ck0, ck0) / (av->rad * av->rad);
800 if (e1 > ambacc*ambacc*1.21)
801 continue;
802 /*
803 * Direction test using closest normal.
804 */
805 d = DOT(av->dir, r->ron);
806 if (rn != r->ron) {
807 rn_dot = DOT(av->dir, rn);
808 if (rn_dot > 1.0-FTINY)
809 rn_dot = 1.0-FTINY;
810 if (rn_dot >= d-FTINY) {
811 d = rn_dot;
812 rn_dot = -2.0;
813 }
814 }
815 e2 = (1.0 - d) * r->rweight;
816 if (e2 < 0.0)
817 e2 = 0.0;
818 else if (e1 + e2 > ambacc*ambacc*1.21)
819 continue;
820 /*
821 * Ray behind test.
822 */
823 d = 0.0;
824 for (j = 0; j < 3; j++)
825 d += (r->rop[j] - av->pos[j]) *
826 (av->dir[j] + r->ron[j]);
827 if (d*0.5 < -minarad*ambacc-.001)
828 continue;
829 /*
830 * Jittering final test reduces image artifacts.
831 */
832 e1 = sqrt(e1);
833 e2 = sqrt(e2);
834 wt = e1 + e2;
835 if (wt > ambacc*(.9+.2*urand(9015+samplendx)))
836 continue;
837 /*
838 * Recompute directional error using perturbed normal
839 */
840 if (rn_dot > 0.0) {
841 e2 = sqrt((1.0 - rn_dot)*r->rweight);
842 wt = e1 + e2;
843 }
844 if (wt <= 1e-3)
845 wt = 1e3;
846 else
847 wt = 1.0 / wt;
848 wsum += wt;
849 extambient(ct, av, r->rop, rn);
850 scalecolor(ct, wt);
851 addcolor(acol, ct);
852 }
853 if (at->kid == NULL)
854 return(wsum);
855 /* do children */
856 s *= 0.5;
857 for (i = 0; i < 8; i++) {
858 for (j = 0; j < 3; j++) {
859 ck0[j] = c0[j];
860 if (1<<j & i)
861 ck0[j] += s;
862 if (r->rop[j] < ck0[j] - OCTSCALE*s)
863 break;
864 if (r->rop[j] > ck0[j] + (1.0+OCTSCALE)*s)
865 break;
866 }
867 if (j == 3)
868 wsum += sumambient(acol, r, rn, al,
869 at->kid+i, ck0, s);
870 }
871 return(wsum);
872 }
873
874
875 static double
876 makeambient( /* make a new ambient value for storage */
877 COLOR acol,
878 RAY *r,
879 FVECT rn,
880 int al
881 )
882 {
883 AMBVAL amb;
884 FVECT gp, gd;
885 int i;
886
887 amb.weight = 1.0; /* compute weight */
888 for (i = al; i-- > 0; )
889 amb.weight *= AVGREFL;
890 if (r->rweight < 0.1*amb.weight) /* heuristic override */
891 amb.weight = 1.25*r->rweight;
892 setcolor(acol, AVGREFL, AVGREFL, AVGREFL);
893 /* compute ambient */
894 amb.rad = doambient(acol, r, amb.weight, gp, gd);
895 if (amb.rad <= FTINY) {
896 setcolor(acol, 0.0, 0.0, 0.0);
897 return(0.0);
898 }
899 scalecolor(acol, 1./AVGREFL); /* undo assumed reflectance */
900 /* store value */
901 VCOPY(amb.pos, r->rop);
902 VCOPY(amb.dir, r->ron);
903 amb.lvl = al;
904 copycolor(amb.val, acol);
905 VCOPY(amb.gpos, gp);
906 VCOPY(amb.gdir, gd);
907 /* insert into tree */
908 avsave(&amb); /* and save to file */
909 if (rn != r->ron)
910 extambient(acol, &amb, r->rop, rn); /* texture */
911 return(amb.rad);
912 }
913
914
915 static void
916 extambient( /* extrapolate value at pv, nv */
917 COLOR cr,
918 AMBVAL *ap,
919 FVECT pv,
920 FVECT nv
921 )
922 {
923 FVECT v1;
924 int i;
925 double d;
926
927 d = 1.0; /* zeroeth order */
928 /* gradient due to translation */
929 for (i = 0; i < 3; i++)
930 d += ap->gpos[i]*(pv[i]-ap->pos[i]);
931 /* gradient due to rotation */
932 VCROSS(v1, ap->dir, nv);
933 d += DOT(ap->gdir, v1);
934 if (d <= 0.0) {
935 setcolor(cr, 0.0, 0.0, 0.0);
936 return;
937 }
938 copycolor(cr, ap->val);
939 scalecolor(cr, d);
940 }
941
942
943 static void
944 avinsert( /* insert ambient value in our tree */
945 AMBVAL *av
946 )
947 {
948 AMBTREE *at;
949 AMBVAL *ap;
950 AMBVAL avh;
951 FVECT ck0;
952 double s;
953 int branch;
954 int i;
955
956 if (av->rad <= FTINY)
957 error(CONSISTENCY, "zero ambient radius in avinsert");
958 at = &atrunk;
959 VCOPY(ck0, thescene.cuorg);
960 s = thescene.cusize;
961 while (s*(OCTSCALE/2) > av->rad*ambacc) {
962 if (at->kid == NULL)
963 if ((at->kid = newambtree()) == NULL)
964 error(SYSTEM, "out of memory in avinsert");
965 s *= 0.5;
966 branch = 0;
967 for (i = 0; i < 3; i++)
968 if (av->pos[i] > ck0[i] + s) {
969 ck0[i] += s;
970 branch |= 1 << i;
971 }
972 at = at->kid + branch;
973 }
974 avh.next = at->alist; /* order by increasing level */
975 for (ap = &avh; ap->next != NULL; ap = ap->next)
976 if ( ap->next->lvl > av->lvl ||
977 (ap->next->lvl == av->lvl) &
978 (ap->next->weight <= av->weight) )
979 break;
980 av->next = ap->next;
981 ap->next = (AMBVAL*)av;
982 at->alist = avh.next;
983 }
984
985 #endif /* ! NEWAMB */
986
987 /************* FOLLOWING ROUTINES SAME FOR NEW & OLD METHODS ***************/
988
989 static void
990 initambfile( /* initialize ambient file */
991 int cre8
992 )
993 {
994 extern char *progname, *octname;
995 static char *mybuf = NULL;
996
997 #ifdef F_SETLKW
998 aflock(cre8 ? F_WRLCK : F_RDLCK);
999 #endif
1000 SET_FILE_BINARY(ambfp);
1001 if (mybuf == NULL)
1002 mybuf = (char *)bmalloc(BUFSIZ+8);
1003 setbuf(ambfp, mybuf);
1004 if (cre8) { /* new file */
1005 newheader("RADIANCE", ambfp);
1006 fprintf(ambfp, "%s -av %g %g %g -aw %d -ab %d -aa %g ",
1007 progname, colval(ambval,RED),
1008 colval(ambval,GRN), colval(ambval,BLU),
1009 ambvwt, ambounce, ambacc);
1010 fprintf(ambfp, "-ad %d -as %d -ar %d ",
1011 ambdiv, ambssamp, ambres);
1012 if (octname != NULL)
1013 fputs(octname, ambfp);
1014 fputc('\n', ambfp);
1015 fprintf(ambfp, "SOFTWARE= %s\n", VersionID);
1016 fputnow(ambfp);
1017 fputformat(AMBFMT, ambfp);
1018 fputc('\n', ambfp);
1019 putambmagic(ambfp);
1020 } else if (checkheader(ambfp, AMBFMT, NULL) < 0 || !hasambmagic(ambfp))
1021 error(USER, "bad ambient file");
1022 }
1023
1024
1025 static void
1026 avsave( /* insert and save an ambient value */
1027 AMBVAL *av
1028 )
1029 {
1030 avstore(av);
1031 if (ambfp == NULL)
1032 return;
1033 if (writambval(av, ambfp) < 0)
1034 goto writerr;
1035 if (++nunflshed >= AMBFLUSH)
1036 if (ambsync() == EOF)
1037 goto writerr;
1038 return;
1039 writerr:
1040 error(SYSTEM, "error writing to ambient file");
1041 }
1042
1043
1044 static AMBVAL *
1045 avstore( /* allocate memory and save aval */
1046 AMBVAL *aval
1047 )
1048 {
1049 AMBVAL *av;
1050 double d;
1051
1052 if ((av = newambval()) == NULL)
1053 error(SYSTEM, "out of memory in avstore");
1054 *av = *aval;
1055 av->latick = ambclock;
1056 av->next = NULL;
1057 nambvals++;
1058 d = bright(av->val);
1059 if (d > FTINY) { /* add to log sum for averaging */
1060 avsum += log(d);
1061 navsum++;
1062 }
1063 avinsert(av); /* insert in our cache tree */
1064 return(av);
1065 }
1066
1067
1068 #define ATALLOCSZ 512 /* #/8 trees to allocate at once */
1069
1070 static AMBTREE *atfreelist = NULL; /* free ambient tree structures */
1071
1072
1073 static AMBTREE *
1074 newambtree(void) /* allocate 8 ambient tree structs */
1075 {
1076 AMBTREE *atp, *upperlim;
1077
1078 if (atfreelist == NULL) { /* get more nodes */
1079 atfreelist = (AMBTREE *)malloc(ATALLOCSZ*8*sizeof(AMBTREE));
1080 if (atfreelist == NULL)
1081 return(NULL);
1082 /* link new free list */
1083 upperlim = atfreelist + 8*(ATALLOCSZ-1);
1084 for (atp = atfreelist; atp < upperlim; atp += 8)
1085 atp->kid = atp + 8;
1086 atp->kid = NULL;
1087 }
1088 atp = atfreelist;
1089 atfreelist = atp->kid;
1090 memset(atp, 0, 8*sizeof(AMBTREE));
1091 return(atp);
1092 }
1093
1094
1095 static void
1096 freeambtree( /* free 8 ambient tree structs */
1097 AMBTREE *atp
1098 )
1099 {
1100 atp->kid = atfreelist;
1101 atfreelist = atp;
1102 }
1103
1104
1105 static void
1106 unloadatree( /* unload an ambient value tree */
1107 AMBTREE *at,
1108 unloadtf_t *f
1109 )
1110 {
1111 AMBVAL *av;
1112 int i;
1113 /* transfer values at this node */
1114 for (av = at->alist; av != NULL; av = at->alist) {
1115 at->alist = av->next;
1116 av->next = NULL;
1117 (*f)(av);
1118 }
1119 if (at->kid == NULL)
1120 return;
1121 for (i = 0; i < 8; i++) /* transfer and free children */
1122 unloadatree(at->kid+i, f);
1123 freeambtree(at->kid);
1124 at->kid = NULL;
1125 }
1126
1127
1128 static struct avl {
1129 AMBVAL *p;
1130 unsigned long t;
1131 } *avlist1; /* ambient value list with ticks */
1132 static AMBVAL **avlist2; /* memory positions for sorting */
1133 static int i_avlist; /* index for lists */
1134
1135 static int alatcmp(const void *av1, const void *av2);
1136
1137 static void
1138 avfree(AMBVAL *av)
1139 {
1140 free(av);
1141 }
1142
1143 static void
1144 av2list(
1145 AMBVAL *av
1146 )
1147 {
1148 #ifdef DEBUG
1149 if (i_avlist >= nambvals)
1150 error(CONSISTENCY, "too many ambient values in av2list1");
1151 #endif
1152 avlist1[i_avlist].p = avlist2[i_avlist] = (AMBVAL*)av;
1153 avlist1[i_avlist++].t = av->latick;
1154 }
1155
1156
1157 static int
1158 alatcmp( /* compare ambient values for MRA */
1159 const void *av1,
1160 const void *av2
1161 )
1162 {
1163 long lc = ((struct avl *)av2)->t - ((struct avl *)av1)->t;
1164 return(lc<0 ? -1 : lc>0 ? 1 : 0);
1165 }
1166
1167
1168 /* GW NOTE 2002/10/3:
1169 * I used to compare AMBVAL pointers, but found that this was the
1170 * cause of a serious consistency error with gcc, since the optimizer
1171 * uses some dangerous trick in pointer subtraction that
1172 * assumes pointers differ by exact struct size increments.
1173 */
1174 static int
1175 aposcmp( /* compare ambient value positions */
1176 const void *avp1,
1177 const void *avp2
1178 )
1179 {
1180 long diff = *(char * const *)avp1 - *(char * const *)avp2;
1181 if (diff < 0)
1182 return(-1);
1183 return(diff > 0);
1184 }
1185
1186
1187 static int
1188 avlmemi( /* find list position from address */
1189 AMBVAL *avaddr
1190 )
1191 {
1192 AMBVAL **avlpp;
1193
1194 avlpp = (AMBVAL **)bsearch(&avaddr, avlist2,
1195 nambvals, sizeof(AMBVAL *), aposcmp);
1196 if (avlpp == NULL)
1197 error(CONSISTENCY, "address not found in avlmemi");
1198 return(avlpp - avlist2);
1199 }
1200
1201
1202 static void
1203 sortambvals( /* resort ambient values */
1204 int always
1205 )
1206 {
1207 AMBTREE oldatrunk;
1208 AMBVAL tav, *tap, *pnext;
1209 int i, j;
1210 /* see if it's time yet */
1211 if (!always && (ambclock++ < lastsort+sortintvl ||
1212 nambvals < SORT_THRESH))
1213 return;
1214 /*
1215 * The idea here is to minimize memory thrashing
1216 * in VM systems by improving reference locality.
1217 * We do this by periodically sorting our stored ambient
1218 * values in memory in order of most recently to least
1219 * recently accessed. This ordering was chosen so that new
1220 * ambient values (which tend to be less important) go into
1221 * higher memory with the infrequently accessed values.
1222 * Since we expect our values to need sorting less
1223 * frequently as the process continues, we double our
1224 * waiting interval after each call.
1225 * This routine is also called by setambacc() with
1226 * the "always" parameter set to 1 so that the ambient
1227 * tree will be rebuilt with the new accuracy parameter.
1228 */
1229 if (tracktime) { /* allocate pointer arrays to sort */
1230 avlist2 = (AMBVAL **)malloc(nambvals*sizeof(AMBVAL *));
1231 avlist1 = (struct avl *)malloc(nambvals*sizeof(struct avl));
1232 } else {
1233 avlist2 = NULL;
1234 avlist1 = NULL;
1235 }
1236 if (avlist1 == NULL) { /* no time tracking -- rebuild tree? */
1237 if (avlist2 != NULL)
1238 free(avlist2);
1239 if (always) { /* rebuild without sorting */
1240 oldatrunk = atrunk;
1241 atrunk.alist = NULL;
1242 atrunk.kid = NULL;
1243 unloadatree(&oldatrunk, avinsert);
1244 }
1245 } else { /* sort memory by last access time */
1246 /*
1247 * Sorting memory is tricky because it isn't contiguous.
1248 * We have to sort an array of pointers by MRA and also
1249 * by memory position. We then copy values in "loops"
1250 * to minimize memory hits. Nevertheless, we will visit
1251 * everyone at least twice, and this is an expensive process
1252 * when we're thrashing, which is when we need to do it.
1253 */
1254 #ifdef DEBUG
1255 sprintf(errmsg, "sorting %u ambient values at ambclock=%lu...",
1256 nambvals, ambclock);
1257 eputs(errmsg);
1258 #endif
1259 i_avlist = 0;
1260 unloadatree(&atrunk, av2list); /* empty current tree */
1261 #ifdef DEBUG
1262 if (i_avlist < nambvals)
1263 error(CONSISTENCY, "missing ambient values in sortambvals");
1264 #endif
1265 qsort(avlist1, nambvals, sizeof(struct avl), alatcmp);
1266 qsort(avlist2, nambvals, sizeof(AMBVAL *), aposcmp);
1267 for (i = 0; i < nambvals; i++) {
1268 if (avlist1[i].p == NULL)
1269 continue;
1270 tap = avlist2[i];
1271 tav = *tap;
1272 for (j = i; (pnext = avlist1[j].p) != tap;
1273 j = avlmemi(pnext)) {
1274 *(avlist2[j]) = *pnext;
1275 avinsert(avlist2[j]);
1276 avlist1[j].p = NULL;
1277 }
1278 *(avlist2[j]) = tav;
1279 avinsert(avlist2[j]);
1280 avlist1[j].p = NULL;
1281 }
1282 free(avlist1);
1283 free(avlist2);
1284 /* compute new sort interval */
1285 sortintvl = ambclock - lastsort;
1286 if (sortintvl >= MAX_SORT_INTVL/2)
1287 sortintvl = MAX_SORT_INTVL;
1288 else
1289 sortintvl <<= 1; /* wait twice as long next */
1290 #ifdef DEBUG
1291 eputs("done\n");
1292 #endif
1293 }
1294 if (ambclock >= MAXACLOCK)
1295 ambclock = MAXACLOCK/2;
1296 lastsort = ambclock;
1297 }
1298
1299
1300 #ifdef F_SETLKW
1301
1302 static void
1303 aflock( /* lock/unlock ambient file */
1304 int typ
1305 )
1306 {
1307 static struct flock fls; /* static so initialized to zeroes */
1308
1309 if (typ == fls.l_type) /* already called? */
1310 return;
1311 fls.l_type = typ;
1312 if (fcntl(fileno(ambfp), F_SETLKW, &fls) < 0)
1313 error(SYSTEM, "cannot (un)lock ambient file");
1314 }
1315
1316
1317 int
1318 ambsync(void) /* synchronize ambient file */
1319 {
1320 long flen;
1321 AMBVAL avs;
1322 int n;
1323
1324 if (ambfp == NULL) /* no ambient file? */
1325 return(0);
1326 /* gain appropriate access */
1327 aflock(nunflshed ? F_WRLCK : F_RDLCK);
1328 /* see if file has grown */
1329 if ((flen = lseek(fileno(ambfp), (off_t)0, SEEK_END)) < 0)
1330 goto seekerr;
1331 if ((n = flen - lastpos) > 0) { /* file has grown */
1332 if (ambinp == NULL) { /* get new file pointer */
1333 ambinp = fopen(ambfile, "rb");
1334 if (ambinp == NULL)
1335 error(SYSTEM, "fopen failed in ambsync");
1336 }
1337 if (fseek(ambinp, lastpos, SEEK_SET) < 0)
1338 goto seekerr;
1339 while (n >= AMBVALSIZ) { /* load contributed values */
1340 if (!readambval(&avs, ambinp)) {
1341 sprintf(errmsg,
1342 "ambient file \"%s\" corrupted near character %ld",
1343 ambfile, flen - n);
1344 error(WARNING, errmsg);
1345 break;
1346 }
1347 avstore(&avs);
1348 n -= AMBVALSIZ;
1349 }
1350 lastpos = flen - n; /* check alignment */
1351 if (n && lseek(fileno(ambfp), (off_t)lastpos, SEEK_SET) < 0)
1352 goto seekerr;
1353 }
1354 n = fflush(ambfp); /* calls write() at last */
1355 lastpos += (long)nunflshed*AMBVALSIZ;
1356 aflock(F_UNLCK); /* release file */
1357 nunflshed = 0;
1358 return(n);
1359 seekerr:
1360 error(SYSTEM, "seek failed in ambsync");
1361 return(EOF); /* pro forma return */
1362 }
1363
1364 #else /* ! F_SETLKW */
1365
1366 int
1367 ambsync(void) /* flush ambient file */
1368 {
1369 if (ambfp == NULL)
1370 return(0);
1371 nunflshed = 0;
1372 return(fflush(ambfp));
1373 }
1374
1375 #endif /* ! F_SETLKW */