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root/radiance/ray/src/rt/source.c
Revision: 2.75
Committed: Mon Jan 4 19:07:15 2021 UTC (3 years, 4 months ago) by greg
Content type: text/plain
Branch: MAIN
Changes since 2.74: +2 -8 lines
Log Message:
refactor: added default initialization of RAY ron, rod members

File Contents

# User Rev Content
1 greg 1.1 #ifndef lint
2 greg 2.75 static const char RCSid[] = "$Id: source.c,v 2.74 2020/12/17 03:30:37 greg Exp $";
3 greg 1.1 #endif
4     /*
5     * source.c - routines dealing with illumination sources.
6     *
7 greg 2.29 * External symbols declared in source.h
8     */
9    
10 greg 1.1 #include "ray.h"
11     #include "otypes.h"
12 greg 2.70 #include "otspecial.h"
13 schorsch 2.44 #include "rtotypes.h"
14 greg 1.35 #include "source.h"
15 greg 2.19 #include "random.h"
16 greg 2.64 #include "pmapsrc.h"
17 rschregle 2.67 #include "pmapmat.h"
18 greg 2.19
19 greg 2.22 #ifndef MAXSSAMP
20     #define MAXSSAMP 16 /* maximum samples per ray */
21     #endif
22    
23 greg 1.35 /*
24     * Structures used by direct()
25     */
26 greg 1.1
27 greg 1.35 typedef struct {
28 greg 1.45 int sno; /* source number */
29 greg 1.35 FVECT dir; /* source direction */
30     COLOR coef; /* material coefficient */
31     COLOR val; /* contribution */
32     } CONTRIB; /* direct contribution */
33 greg 1.1
34 greg 1.35 typedef struct {
35 greg 1.45 int sndx; /* source index (to CONTRIB array) */
36 greg 1.35 float brt; /* brightness (for comparison) */
37     } CNTPTR; /* contribution pointer */
38 greg 1.1
39 greg 1.25 static CONTRIB *srccnt; /* source contributions in direct() */
40     static CNTPTR *cntord; /* source ordering in direct() */
41 greg 1.45 static int maxcntr = 0; /* size of contribution arrays */
42 greg 1.1
43 schorsch 2.44 static int cntcmp(const void *p1, const void *p2);
44    
45 greg 1.25
46 greg 2.62 void
47 schorsch 2.44 marksources(void) /* find and mark source objects */
48 greg 1.1 {
49 greg 2.3 int foundsource = 0;
50 greg 1.33 int i;
51 greg 2.62 OBJREC *o, *m;
52     int ns;
53 greg 1.35 /* initialize dispatch table */
54     initstypes();
55     /* find direct sources */
56 greg 2.33 for (i = 0; i < nsceneobjs; i++) {
57 greg 1.1
58     o = objptr(i);
59    
60 greg 1.35 if (!issurface(o->otype) || o->omod == OVOID)
61 greg 1.1 continue;
62 greg 2.36 /* find material */
63 greg 2.43 m = findmaterial(objptr(o->omod));
64 greg 2.56 if (m == NULL)
65     continue;
66     if (m->otype == MAT_CLIP) {
67     markclip(m); /* special case for antimatter */
68     continue;
69     }
70     if (!islight(m->otype))
71 greg 2.36 continue; /* not source modifier */
72 greg 1.1
73 greg 1.6 if (m->oargs.nfargs != (m->otype == MAT_GLOW ? 4 :
74     m->otype == MAT_SPOT ? 7 : 3))
75 greg 1.1 objerror(m, USER, "bad # arguments");
76    
77 greg 2.72 if (m->oargs.farg[0] <= FTINY && (m->oargs.farg[1] <= FTINY) &
78     (m->oargs.farg[2] <= FTINY))
79 greg 2.16 continue; /* don't bother */
80 greg 2.61 if (m->otype == MAT_GLOW &&
81     o->otype != OBJ_SOURCE &&
82     m->oargs.farg[3] <= FTINY) {
83     foundsource += (ambounce > 0);
84     continue; /* don't track these */
85     }
86 greg 1.35 if (sfun[o->otype].of == NULL ||
87     sfun[o->otype].of->setsrc == NULL)
88     objerror(o, USER, "illegal material");
89    
90 greg 1.36 if ((ns = newsource()) < 0)
91 greg 1.25 goto memerr;
92 greg 1.1
93 greg 1.37 setsource(&source[ns], o);
94 greg 1.1
95 greg 1.6 if (m->otype == MAT_GLOW) {
96 greg 1.36 source[ns].sflags |= SPROX;
97     source[ns].sl.prox = m->oargs.farg[3];
98 greg 2.61 if (source[ns].sflags & SDISTANT) {
99 greg 1.36 source[ns].sflags |= SSKIP;
100 greg 2.61 foundsource += (ambounce > 0);
101     }
102 greg 1.6 } else if (m->otype == MAT_SPOT) {
103 greg 2.72 if (source[ns].sflags & SDISTANT)
104     objerror(o, WARNING,
105     "distant source is a spotlight");
106 greg 1.36 source[ns].sflags |= SSPOT;
107     if ((source[ns].sl.s = makespot(m)) == NULL)
108 greg 1.33 goto memerr;
109 greg 1.38 if (source[ns].sflags & SFLAT &&
110     !checkspot(source[ns].sl.s,source[ns].snorm)) {
111     objerror(o, WARNING,
112     "invalid spotlight direction");
113     source[ns].sflags |= SSKIP;
114     }
115 greg 1.6 }
116 greg 2.61 foundsource += !(source[ns].sflags & SSKIP);
117 greg 1.1 }
118 greg 2.3 if (!foundsource) {
119 greg 1.25 error(WARNING, "no light sources found");
120     return;
121     }
122 greg 2.65 #if SHADCACHE
123 greg 2.66 for (ns = 0; ns < nsources; ns++) /* initialize obstructor cache */
124     initobscache(ns);
125 greg 2.65 #endif
126 greg 2.64 /* PMAP: disable virtual sources */
127     if (!photonMapping)
128     markvirtuals(); /* find and add virtual sources */
129    
130 greg 1.45 /* allocate our contribution arrays */
131 greg 1.48 maxcntr = nsources + MAXSPART; /* start with this many */
132 greg 1.45 srccnt = (CONTRIB *)malloc(maxcntr*sizeof(CONTRIB));
133     cntord = (CNTPTR *)malloc(maxcntr*sizeof(CNTPTR));
134 greg 2.72 if ((srccnt != NULL) & (cntord != NULL))
135     return;
136 greg 1.25 memerr:
137     error(SYSTEM, "out of memory in marksources");
138 greg 1.1 }
139    
140    
141 greg 2.62 void
142 greg 2.72 distantsources(void) /* only mark distant sources */
143     {
144     int i;
145     OBJREC *o, *m;
146     int ns;
147     /* initialize dispatch table */
148     initstypes();
149     /* sources needed for sourcehit() */
150     for (i = 0; i < nsceneobjs; i++) {
151    
152     o = objptr(i);
153    
154     if ((o->otype != OBJ_SOURCE) | (o->omod == OVOID))
155     continue;
156     /* find material */
157     m = findmaterial(objptr(o->omod));
158     if (m == NULL)
159     continue;
160     if (!islight(m->otype))
161     continue; /* not source modifier */
162    
163     if (m->oargs.nfargs != (m->otype == MAT_GLOW ? 4 :
164     m->otype == MAT_SPOT ? 7 : 3))
165     objerror(m, USER, "bad # arguments");
166    
167     if (m->oargs.farg[0] <= FTINY && (m->oargs.farg[1] <= FTINY) &
168     (m->oargs.farg[2] <= FTINY))
169     continue; /* don't bother */
170     if (sfun[o->otype].of == NULL ||
171     sfun[o->otype].of->setsrc == NULL)
172     objerror(o, USER, "illegal material");
173    
174     if ((ns = newsource()) < 0)
175     error(SYSTEM, "out of memory in distantsources");
176    
177     setsource(&source[ns], o);
178    
179     if (m->otype == MAT_GLOW) {
180     source[ns].sflags |= SPROX|SSKIP;
181     source[ns].sl.prox = m->oargs.farg[3];
182     } else if (m->otype == MAT_SPOT)
183     objerror(o, WARNING, "distant source is a spotlight");
184     }
185     }
186    
187    
188     void
189 schorsch 2.44 freesources(void) /* free all source structures */
190 greg 2.29 {
191     if (nsources > 0) {
192 greg 2.38 #if SHADCACHE
193     while (nsources--)
194     freeobscache(&source[nsources]);
195     #endif
196 greg 2.29 free((void *)source);
197     source = NULL;
198     nsources = 0;
199     }
200 greg 2.60 markclip(NULL);
201 greg 2.29 if (maxcntr <= 0)
202     return;
203     free((void *)srccnt);
204     srccnt = NULL;
205     free((void *)cntord);
206     cntord = NULL;
207     maxcntr = 0;
208     }
209    
210    
211 greg 2.62 int
212 greg 2.38 srcray( /* send a ray to a source, return domega */
213 greg 2.62 RAY *sr, /* returned source ray */
214 schorsch 2.44 RAY *r, /* ray which hit object */
215     SRCINDEX *si /* source sample index */
216 greg 2.38 )
217 greg 1.1 {
218 greg 2.59 double d; /* distance to source */
219 greg 2.62 SRCREC *srcp;
220 greg 1.1
221 greg 2.59 rayorigin(sr, SHADOW, r, NULL); /* ignore limits */
222 greg 1.1
223 greg 2.59 if (r == NULL)
224     sr->rmax = 0.0;
225    
226     while ((d = nextssamp(sr, si)) != 0.0) {
227     sr->rsrc = si->sn; /* remember source */
228     srcp = source + si->sn;
229     if (srcp->sflags & SDISTANT) {
230     if (srcp->sflags & SSPOT && spotout(sr, srcp->sl.s))
231     continue;
232     return(1); /* sample OK */
233     }
234 greg 1.45 /* local source */
235 greg 1.6 /* check proximity */
236 greg 2.59 if (srcp->sflags & SPROX && d > srcp->sl.prox)
237     continue;
238 greg 1.6 /* check angle */
239 greg 2.59 if (srcp->sflags & SSPOT) {
240     if (spotout(sr, srcp->sl.s))
241     continue;
242 greg 1.45 /* adjust solid angle */
243 greg 2.59 si->dom *= d*d;
244     d += srcp->sl.s->flen;
245     si->dom /= d*d;
246     }
247     return(1); /* sample OK */
248     }
249     return(0); /* no more samples */
250 greg 1.1 }
251    
252    
253 greg 2.62 void
254 greg 2.38 srcvalue( /* punch ray to source and compute value */
255 greg 2.62 RAY *r
256 greg 2.38 )
257 greg 1.1 {
258 greg 2.62 SRCREC *sp;
259 greg 1.1
260 greg 1.35 sp = &source[r->rsrc];
261     if (sp->sflags & SVIRTUAL) { /* virtual source */
262     /* check intersection */
263     if (!(*ofun[sp->so->otype].funp)(sp->so, r))
264     return;
265 greg 2.15 if (!rayshade(r, r->ro->omod)) /* compute contribution */
266     goto nomat;
267 greg 2.19 rayparticipate(r);
268 greg 1.35 return;
269 greg 1.1 }
270 greg 1.35 /* compute intersection */
271     if (sp->sflags & SDISTANT ? sourcehit(r) :
272     (*ofun[sp->so->otype].funp)(sp->so, r)) {
273     if (sp->sa.success >= 0)
274     sp->sa.success++;
275 greg 2.15 if (!rayshade(r, r->ro->omod)) /* compute contribution */
276     goto nomat;
277 greg 2.19 rayparticipate(r);
278 greg 1.35 return;
279 greg 1.1 }
280 greg 2.15 /* we missed our mark! */
281 greg 1.35 if (sp->sa.success < 0)
282     return; /* bitched already */
283     sp->sa.success -= AIMREQT;
284     if (sp->sa.success >= 0)
285     return; /* leniency */
286     sprintf(errmsg, "aiming failure for light source \"%s\"",
287     sp->so->oname);
288     error(WARNING, errmsg); /* issue warning */
289 greg 2.15 return;
290     nomat:
291     objerror(r->ro, USER, "material not found");
292 greg 1.1 }
293    
294    
295 greg 2.47 static int
296     transillum( /* check if material is transparent illum */
297     OBJECT obj
298     )
299     {
300     OBJREC *m = findmaterial(objptr(obj));
301    
302     if (m == NULL)
303     return(1);
304     if (m->otype != MAT_ILLUM)
305     return(0);
306     return(!m->oargs.nsargs || !strcmp(m->oargs.sarg[0], VOIDID));
307     }
308    
309    
310 greg 2.62 int
311 greg 2.38 sourcehit( /* check to see if ray hit distant source */
312 greg 2.62 RAY *r
313 greg 2.38 )
314 greg 2.5 {
315 greg 2.47 int glowsrc = -1;
316     int transrc = -1;
317 greg 2.5 int first, last;
318 greg 2.62 int i;
319 greg 2.5
320     if (r->rsrc >= 0) { /* check only one if aimed */
321     first = last = r->rsrc;
322     } else { /* otherwise check all */
323     first = 0; last = nsources-1;
324     }
325 greg 2.47 for (i = first; i <= last; i++) {
326     if ((source[i].sflags & (SDISTANT|SVIRTUAL)) != SDISTANT)
327     continue;
328     /*
329     * Check to see if ray is within
330     * solid angle of source.
331     */
332     if (2.*PI*(1. - DOT(source[i].sloc,r->rdir)) > source[i].ss2)
333     continue;
334     /* is it the only possibility? */
335     if (first == last) {
336     r->ro = source[i].so;
337     break;
338     }
339     /*
340     * If it's a glow or transparent illum, just remember it.
341     */
342     if (source[i].sflags & SSKIP) {
343 greg 2.58 if (glowsrc < 0)
344     glowsrc = i;
345 greg 2.47 continue;
346     }
347     if (transillum(source[i].so->omod)) {
348 greg 2.58 if (transrc < 0)
349     transrc = i;
350 greg 2.47 continue;
351     }
352     r->ro = source[i].so; /* otherwise, use first hit */
353     break;
354 greg 2.5 }
355 greg 2.47 /*
356     * Do we need fallback?
357     */
358     if (r->ro == NULL) {
359     if (transrc >= 0 && r->crtype & (AMBIENT|SPECULAR))
360     return(0); /* avoid overcounting */
361     if (glowsrc >= 0)
362     r->ro = source[glowsrc].so;
363     else
364     return(0); /* nothing usable */
365     }
366     /*
367 greg 2.75 * Assign object index
368 greg 2.47 */
369     r->robj = objndx(r->ro);
370     return(1);
371 greg 2.5 }
372 greg 2.38
373    
374 greg 1.4 static int
375 greg 2.38 cntcmp( /* contribution compare (descending) */
376 schorsch 2.44 const void *p1,
377     const void *p2
378 greg 2.38 )
379 greg 1.4 {
380 greg 2.62 const CNTPTR *sc1 = (const CNTPTR *)p1;
381     const CNTPTR *sc2 = (const CNTPTR *)p2;
382 greg 2.38
383 greg 1.4 if (sc1->brt > sc2->brt)
384     return(-1);
385     if (sc1->brt < sc2->brt)
386     return(1);
387     return(0);
388     }
389    
390    
391 greg 2.62 void
392 greg 2.38 direct( /* add direct component */
393 schorsch 2.44 RAY *r, /* ray that hit surface */
394     srcdirf_t *f, /* direct component coefficient function */
395     void *p /* data for f */
396 greg 2.38 )
397 greg 1.4 {
398 greg 2.62 int sn;
399     CONTRIB *scp;
400 greg 1.45 SRCINDEX si;
401 greg 1.12 int nshadcheck, ncnts;
402 greg 1.29 int nhits;
403 greg 1.45 double prob, ourthresh, hwt;
404 greg 1.4 RAY sr;
405 greg 2.64
406     /* PMAP: Factor in direct photons (primarily for debugging/validation) */
407     if (directPhotonMapping) {
408     (*f)(r -> rcol, p, r -> ron, PI);
409     multDirectPmap(r);
410     return;
411     }
412    
413 greg 1.25 /* NOTE: srccnt and cntord global so no recursion */
414 greg 1.22 if (nsources <= 0)
415 greg 1.25 return; /* no sources?! */
416 greg 1.4 /* potential contributions */
417 greg 1.45 initsrcindex(&si);
418     for (sn = 0; srcray(&sr, r, &si); sn++) {
419     if (sn >= maxcntr) {
420     maxcntr = sn + MAXSPART;
421 greg 2.32 srccnt = (CONTRIB *)realloc((void *)srccnt,
422 greg 1.45 maxcntr*sizeof(CONTRIB));
423 greg 2.32 cntord = (CNTPTR *)realloc((void *)cntord,
424 greg 1.45 maxcntr*sizeof(CNTPTR));
425 schorsch 2.35 if ((srccnt == NULL) | (cntord == NULL))
426 greg 1.45 error(SYSTEM, "out of memory in direct");
427     }
428     cntord[sn].sndx = sn;
429 greg 2.7 scp = srccnt + sn;
430     scp->sno = sr.rsrc;
431 greg 2.73 #if SHADCACHE /* check shadow cache */
432     if (si.np == 1 && srcblocked(&sr)) {
433     cntord[sn].brt = 0.0;
434     continue;
435     }
436     #endif
437 greg 1.4 /* compute coefficient */
438 greg 2.7 (*f)(scp->coef, p, sr.rdir, si.dom);
439 greg 2.53 cntord[sn].brt = intens(scp->coef);
440 greg 1.15 if (cntord[sn].brt <= 0.0)
441 greg 1.4 continue;
442 greg 2.7 VCOPY(scp->dir, sr.rdir);
443 greg 2.50 copycolor(sr.rcoef, scp->coef);
444 greg 1.35 /* compute potential */
445 greg 2.51 sr.revf = srcvalue;
446     rayvalue(&sr);
447 greg 2.50 multcolor(sr.rcol, sr.rcoef);
448 greg 2.7 copycolor(scp->val, sr.rcol);
449 greg 2.57 cntord[sn].brt = bright(sr.rcol);
450 greg 1.4 }
451     /* sort contributions */
452 greg 1.45 qsort(cntord, sn, sizeof(CNTPTR), cntcmp);
453 greg 1.13 { /* find last */
454 greg 2.62 int l, m;
455 greg 1.13
456 greg 1.45 ncnts = l = sn;
457     sn = 0;
458 greg 1.13 while ((m = (sn + ncnts) >> 1) != l) {
459     if (cntord[m].brt > 0.0)
460     sn = m;
461     else
462     ncnts = m;
463     l = m;
464     }
465     }
466 greg 2.2 if (ncnts == 0)
467     return; /* no contributions! */
468 greg 1.12 /* accumulate tail */
469     for (sn = ncnts-1; sn > 0; sn--)
470     cntord[sn-1].brt += cntord[sn].brt;
471 greg 1.45 /* compute number to check */
472     nshadcheck = pow((double)ncnts, shadcert) + .5;
473     /* modify threshold */
474 greg 2.74 ourthresh = shadthresh / r->rweight;
475 greg 1.10 /* test for shadows */
476 greg 2.13 for (nhits = 0, hwt = 0.0, sn = 0; sn < ncnts;
477     hwt += (double)source[scp->sno].nhits /
478     (double)source[scp->sno].ntests,
479     sn++) {
480 greg 1.10 /* check threshold */
481 greg 2.74 if (sn >= MINSHADCNT &&
482     (sn+nshadcheck>=ncnts ? cntord[sn].brt :
483 greg 1.27 cntord[sn].brt-cntord[sn+nshadcheck].brt)
484 greg 2.74 < ourthresh*bright(r->rcol))
485 greg 1.4 break;
486 greg 2.7 scp = srccnt + cntord[sn].sndx;
487 greg 1.4 /* test for hit */
488 greg 2.52 rayorigin(&sr, SHADOW, r, NULL);
489     copycolor(sr.rcoef, scp->coef);
490 greg 2.7 VCOPY(sr.rdir, scp->dir);
491     sr.rsrc = scp->sno;
492 greg 2.34 /* keep statistics */
493     if (source[scp->sno].ntests++ > 0xfffffff0) {
494     source[scp->sno].ntests >>= 1;
495     source[scp->sno].nhits >>= 1;
496     }
497 greg 1.4 if (localhit(&sr, &thescene) &&
498 greg 2.7 ( sr.ro != source[scp->sno].so ||
499     source[scp->sno].sflags & SFOLLOW )) {
500 greg 1.33 /* follow entire path */
501 greg 2.23 raycont(&sr);
502 greg 1.42 if (trace != NULL)
503     (*trace)(&sr); /* trace execution */
504 greg 2.38 if (bright(sr.rcol) <= FTINY) {
505     #if SHADCACHE
506     if ((scp <= srccnt || scp[-1].sno != scp->sno)
507 greg 2.41 && (scp >= srccnt+ncnts-1 ||
508 greg 2.38 scp[1].sno != scp->sno))
509     srcblocker(&sr);
510     #endif
511 greg 1.4 continue; /* missed! */
512 greg 2.38 }
513 greg 2.55 rayparticipate(&sr);
514 greg 2.51 multcolor(sr.rcol, sr.rcoef);
515 greg 2.7 copycolor(scp->val, sr.rcol);
516 greg 2.51 } else if (trace != NULL &&
517     (source[scp->sno].sflags & (SDISTANT|SVIRTUAL|SFOLLOW))
518     == (SDISTANT|SFOLLOW) &&
519     sourcehit(&sr) && rayshade(&sr, sr.ro->omod)) {
520     (*trace)(&sr); /* trace execution */
521     /* skip call to rayparticipate() & scp->val update */
522 greg 1.4 }
523     /* add contribution if hit */
524 greg 2.7 addcolor(r->rcol, scp->val);
525 greg 1.29 nhits++;
526 greg 2.7 source[scp->sno].nhits++;
527 greg 1.4 }
528 greg 2.13 /* source hit rate */
529     if (hwt > FTINY)
530     hwt = (double)nhits / hwt;
531 greg 1.29 else
532     hwt = 0.5;
533 greg 1.20 #ifdef DEBUG
534 greg 2.13 sprintf(errmsg, "%d tested, %d untested, %f conditional hit rate\n",
535 greg 1.12 sn, ncnts-sn, hwt);
536     eputs(errmsg);
537 greg 1.4 #endif
538     /* add in untested sources */
539 greg 1.12 for ( ; sn < ncnts; sn++) {
540 greg 2.7 scp = srccnt + cntord[sn].sndx;
541     prob = hwt * (double)source[scp->sno].nhits /
542     (double)source[scp->sno].ntests;
543 greg 2.51 if (prob < 1.0)
544     scalecolor(scp->val, prob);
545 greg 2.7 addcolor(r->rcol, scp->val);
546 greg 2.19 }
547     }
548    
549    
550 greg 2.62 void
551 greg 2.38 srcscatter( /* compute source scattering into ray */
552 greg 2.62 RAY *r
553 greg 2.38 )
554 greg 2.19 {
555 greg 2.20 int oldsampndx;
556 greg 2.19 int nsamps;
557     RAY sr;
558     SRCINDEX si;
559 greg 2.25 double t, d;
560     double re, ge, be;
561 greg 2.68 COLOR cvext;
562 greg 2.19 int i, j;
563    
564 greg 2.71 if (r->rot >= FHUGE*.99 || r->gecc >= 1.-FTINY)
565 greg 2.68 return; /* this can never work */
566     /* PMAP: do unconditional inscattering for volume photons */
567     if (!volumePhotonMapping && (r->slights == NULL || r->slights[0] == 0))
568 greg 2.19 return;
569 greg 2.64
570 greg 2.19 if (ssampdist <= FTINY || (nsamps = r->rot/ssampdist + .5) < 1)
571     nsamps = 1;
572 greg 2.22 #if MAXSSAMP
573     else if (nsamps > MAXSSAMP)
574     nsamps = MAXSSAMP;
575     #endif
576 greg 2.20 oldsampndx = samplendx;
577     samplendx = random()&0x7fff; /* randomize */
578 greg 2.68 for (i = volumePhotonMapping ? 1 : r->slights[0]; i > 0; i--) {
579     /* for each source OR once if volume photon map enabled */
580 greg 2.25 for (j = 0; j < nsamps; j++) { /* for each sample position */
581 greg 2.19 samplendx++;
582     t = r->rot * (j+frandom())/nsamps;
583 greg 2.25 /* extinction */
584     re = t*colval(r->cext,RED);
585     ge = t*colval(r->cext,GRN);
586     be = t*colval(r->cext,BLU);
587     setcolor(cvext, re > 92. ? 0. : exp(-re),
588     ge > 92. ? 0. : exp(-ge),
589     be > 92. ? 0. : exp(-be));
590     if (intens(cvext) <= FTINY)
591     break; /* too far away */
592 greg 2.19 sr.rorg[0] = r->rorg[0] + r->rdir[0]*t;
593     sr.rorg[1] = r->rorg[1] + r->rdir[1]*t;
594     sr.rorg[2] = r->rorg[2] + r->rdir[2]*t;
595 greg 2.68
596     if (!volumePhotonMapping) {
597     initsrcindex(&si); /* sample ray to this source */
598     si.sn = r->slights[i];
599     nopart(&si, &sr);
600     if (!srcray(&sr, NULL, &si) ||
601     sr.rsrc != r->slights[i])
602     continue; /* no path */
603 greg 2.45 #if SHADCACHE
604 greg 2.68 if (srcblocked(&sr)) /* check shadow cache */
605     continue;
606 greg 2.45 #endif
607 greg 2.68 copycolor(sr.cext, r->cext);
608     copycolor(sr.albedo, r->albedo);
609     sr.gecc = r->gecc;
610     sr.slights = r->slights;
611     rayvalue(&sr); /* eval. source ray */
612     if (bright(sr.rcol) <= FTINY) {
613 greg 2.45 #if SHADCACHE
614 greg 2.68 srcblocker(&sr); /* add blocker to cache */
615 greg 2.45 #endif
616 greg 2.68 continue;
617     }
618     if (r->gecc <= FTINY) /* compute P(theta) */
619     d = 1.;
620     else {
621     d = DOT(r->rdir, sr.rdir);
622     d = 1. + r->gecc*r->gecc - 2.*r->gecc*d;
623     d = (1. - r->gecc*r->gecc) / (d*sqrt(d));
624     }
625     /* other factors */
626     d *= si.dom * r->rot / (4.*PI*nsamps);
627     scalecolor(sr.rcol, d);
628     } else {
629     /* PMAP: Add ambient inscattering from
630     * volume photons; note we reverse the
631     * incident ray direction since we're
632     * now in *backward* raytracing mode! */
633     sr.rdir [0] = -r -> rdir [0];
634     sr.rdir [1] = -r -> rdir [1];
635     sr.rdir [2] = -r -> rdir [2];
636     sr.gecc = r -> gecc;
637     inscatterVolumePmap(&sr, sr.rcol);
638     scalecolor(sr.rcol, r -> rot / nsamps);
639 greg 2.45 }
640 greg 2.19 multcolor(sr.rcol, r->cext);
641 greg 2.24 multcolor(sr.rcol, r->albedo);
642 greg 2.25 multcolor(sr.rcol, cvext);
643     addcolor(r->rcol, sr.rcol); /* add it in */
644 greg 2.19 }
645 greg 1.1 }
646 greg 2.20 samplendx = oldsampndx;
647 greg 2.4 }
648    
649    
650     /****************************************************************
651     * The following macros were separated from the m_light() routine
652     * because they are very nasty and difficult to understand.
653     */
654    
655 greg 2.11 /* illumblock *
656 greg 2.4 *
657     * We cannot allow an illum to pass to another illum, because that
658     * would almost certainly constitute overcounting.
659     * However, we do allow an illum to pass to another illum
660     * that is actually going to relay to a virtual light source.
661 greg 2.11 * We also prevent an illum from passing to a glow; this provides a
662     * convenient mechanism for defining detailed light source
663     * geometry behind (or inside) an effective radiator.
664 greg 2.4 */
665    
666 greg 2.37 static int
667 greg 2.42 weaksrcmat(OBJECT obj) /* identify material */
668 greg 2.37 {
669 greg 2.47 OBJREC *m = findmaterial(objptr(obj));
670 greg 2.37
671 greg 2.47 if (m == NULL) return(0);
672     return((m->otype==MAT_ILLUM) | (m->otype==MAT_GLOW));
673 greg 2.37 }
674 greg 2.4
675 greg 2.11 #define illumblock(m, r) (!(source[r->rsrc].sflags&SVIRTUAL) && \
676 greg 2.12 r->rod > 0.0 && \
677 greg 2.37 weaksrcmat(source[r->rsrc].so->omod))
678 greg 2.11
679 greg 2.4 /* wrongsource *
680     *
681     * This source is the wrong source (ie. overcounted) if we are
682     * aimed to a different source than the one we hit and the one
683 greg 2.11 * we hit is not an illum that should be passed.
684 greg 2.4 */
685    
686     #define wrongsource(m, r) (r->rsrc>=0 && source[r->rsrc].so!=r->ro && \
687 greg 2.11 (m->otype!=MAT_ILLUM || illumblock(m,r)))
688 greg 2.4
689     /* distglow *
690     *
691     * A distant glow is an object that sometimes acts as a light source,
692     * but is too far away from the test point to be one in this case.
693 greg 2.11 * (Glows with negative radii should NEVER participate in illumination.)
694 greg 2.4 */
695    
696 greg 2.17 #define distglow(m, r, d) (m->otype==MAT_GLOW && \
697 greg 2.10 m->oargs.farg[3] >= -FTINY && \
698 greg 2.17 d > m->oargs.farg[3])
699 greg 2.4
700     /* badcomponent *
701     *
702     * We must avoid counting light sources in the ambient calculation,
703     * since the direct component is handled separately. Therefore, any
704     * ambient ray which hits an active light source must be discarded.
705     * The same is true for stray specular samples, since the specular
706     * contribution from light sources is calculated separately.
707     */
708 rschregle 2.67 /* PMAP: Also avoid counting sources via transferred ambient rays (e.g.
709     * through glass) when photon mapping is enabled, as these indirect
710     * components are already accounted for.
711     */
712     #define badcomponent(m, r) (srcRayInPmap(r) || \
713     (r->crtype&(AMBIENT|SPECULAR) && \
714 greg 2.4 !(r->crtype&SHADOW || r->rod < 0.0 || \
715 rschregle 2.67 /* not 100% correct */ distglow(m, r, r->rot))))
716 greg 2.4
717     /* passillum *
718     *
719     * An illum passes to another material type when we didn't hit it
720     * on purpose (as part of a direct calculation), or it is relaying
721     * a virtual light source.
722     */
723    
724     #define passillum(m, r) (m->otype==MAT_ILLUM && \
725     (r->rsrc<0 || source[r->rsrc].so!=r->ro || \
726     source[r->rsrc].sflags&SVIRTUAL))
727    
728     /* srcignore *
729     *
730 greg 2.10 * The -dv flag is normally on for sources to be visible.
731 greg 2.4 */
732    
733 greg 2.17 #define srcignore(m, r) !(directvis || r->crtype&SHADOW || \
734     distglow(m, r, raydist(r,PRIMARY)))
735 greg 2.4
736    
737 greg 2.62 int
738 greg 2.38 m_light( /* ray hit a light source */
739 greg 2.62 OBJREC *m,
740     RAY *r
741 greg 2.38 )
742 greg 2.4 {
743     /* check for over-counting */
744 greg 2.50 if (badcomponent(m, r)) {
745     setcolor(r->rcoef, 0.0, 0.0, 0.0);
746 greg 2.14 return(1);
747 greg 2.50 }
748     if (wrongsource(m, r)) {
749     setcolor(r->rcoef, 0.0, 0.0, 0.0);
750 greg 2.14 return(1);
751 greg 2.50 }
752 greg 2.4 /* check for passed illum */
753     if (passillum(m, r)) {
754 greg 2.14 if (m->oargs.nsargs && strcmp(m->oargs.sarg[0], VOIDID))
755 gwlarson 2.28 return(rayshade(r,lastmod(objndx(m),m->oargs.sarg[0])));
756 greg 2.14 raytrans(r);
757     return(1);
758 greg 2.4 }
759 greg 2.50 /* check for invisibility */
760     if (srcignore(m, r)) {
761     setcolor(r->rcoef, 0.0, 0.0, 0.0);
762     return(1);
763     }
764 greg 2.4 /* otherwise treat as source */
765     /* check for behind */
766     if (r->rod < 0.0)
767 greg 2.14 return(1);
768 greg 2.4 /* check for outside spot */
769 greg 2.18 if (m->otype==MAT_SPOT && spotout(r, makespot(m)))
770 greg 2.14 return(1);
771 greg 2.4 /* get distribution pattern */
772     raytexture(r, m->omod);
773     /* get source color */
774     setcolor(r->rcol, m->oargs.farg[0],
775     m->oargs.farg[1],
776     m->oargs.farg[2]);
777     /* modify value */
778     multcolor(r->rcol, r->pcol);
779 greg 2.14 return(1);
780 greg 1.1 }