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root/radiance/ray/src/rt/srcsupp.c
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Comparing ray/src/rt/srcsupp.c (file contents):
Revision 2.2 by greg, Sat Jan 4 19:54:20 1992 UTC vs.
Revision 2.6 by greg, Fri Aug 28 15:10:47 1992 UTC

# Line 239 | Line 239 | register OBJREC  *m;
239   {
240          register SPOT  *ns;
241  
242 +        if ((ns = (SPOT *)m->os) != NULL)
243 +                return(ns);
244          if ((ns = (SPOT *)malloc(sizeof(SPOT))) == NULL)
245                  return(NULL);
246          ns->siz = 2.0*PI * (1.0 - cos(PI/180.0/2.0 * m->oargs.farg[3]));
247          VCOPY(ns->aim, m->oargs.farg+4);
248          if ((ns->flen = normalize(ns->aim)) == 0.0)
249                  objerror(m, USER, "zero focus vector");
250 +        m->os = (char *)ns;
251          return(ns);
252   }
253  
254  
255 + spotout(r, s, dist)             /* check if we're outside spot region */
256 + register RAY  *r;
257 + register SPOT  *s;
258 + int  dist;
259 + {
260 +        double  d;
261 +        FVECT  vd;
262 +        
263 +        if (s == NULL)
264 +                return(0);
265 +        if (dist) {                     /* distant source */
266 +                vd[0] = s->aim[0] - r->rorg[0];
267 +                vd[1] = s->aim[1] - r->rorg[1];
268 +                vd[2] = s->aim[2] - r->rorg[2];
269 +                d = DOT(r->rdir,vd);
270 +                /*                      wrong side?
271 +                if (d <= FTINY)
272 +                        return(1);      */
273 +                d = DOT(vd,vd) - d*d;
274 +                if (PI*d > s->siz)
275 +                        return(1);      /* out */
276 +                return(0);      /* OK */
277 +        }
278 +                                        /* local source */
279 +        if (s->siz < 2.0*PI * (1.0 + DOT(s->aim,r->rdir)))
280 +                return(1);      /* out */
281 +        return(0);      /* OK */
282 + }
283 +
284 +
285   double
286   fgetmaxdisk(ocent, op)          /* get center and squared radius of face */
287   FVECT  ocent;
# Line 462 | Line 495 | double  r1s, r2s;              /* radii squared */
495          for (i = 0; i < 3; i++)
496                  cc[i] = c1[i] + l*disp[i];
497          return(a2);
465 }
466
467
468 sourcehit(r)                    /* check to see if ray hit distant source */
469 register RAY  *r;
470 {
471        int  first, last;
472        register int  i;
473
474        if (r->rsrc >= 0) {             /* check only one if aimed */
475                first = last = r->rsrc;
476        } else {                        /* otherwise check all */
477                first = 0; last = nsources-1;
478        }
479        for (i = first; i <= last; i++)
480                if ((source[i].sflags & (SDISTANT|SVIRTUAL)) == SDISTANT)
481                        /*
482                         * Check to see if ray is within
483                         * solid angle of source.
484                         */
485                        if (2.0*PI * (1.0 - DOT(source[i].sloc,r->rdir))
486                                        <= source[i].ss2) {
487                                r->ro = source[i].so;
488                                if (!(source[i].sflags & SSKIP))
489                                        break;
490                        }
491
492        if (r->ro != NULL) {
493                for (i = 0; i < 3; i++)
494                        r->ron[i] = -r->rdir[i];
495                r->rod = 1.0;
496                r->rox = NULL;
497                return(1);
498        }
499        return(0);
500 }
501
502
503 /****************************************************************
504 * The following macros were separated from the m_light() routine
505 * because they are very nasty and difficult to understand.
506 */
507
508 /* wrongillum *
509 *
510 * We cannot allow an illum to pass to another illum, because that
511 * would almost certainly constitute overcounting.
512 * However, we do allow an illum to pass to another illum
513 * that is actually going to relay to a virtual light source.
514 */
515
516 #define  wrongillum(m, r)       (!(source[r->rsrc].sflags&SVIRTUAL) && \
517                        objptr(source[r->rsrc].so->omod)->otype==MAT_ILLUM)
518
519 /* wrongsource *
520 *
521 * This source is the wrong source (ie. overcounted) if we are
522 * aimed to a different source than the one we hit and the one
523 * we hit is not an illum which should be passed.
524 */
525
526 #define  wrongsource(m, r)      (r->rsrc>=0 && source[r->rsrc].so!=r->ro && \
527                                (m->otype!=MAT_ILLUM || wrongillum(m,r)))
528
529 /* badspecular *
530 *
531 * Any undirected specular ray that hits a light source
532 * should be discarded.  This is because the source contribution to
533 * specular components is calculated separately to reduce variance.
534 */
535
536 #define  badspecular(m, r)      (r->rsrc<0 && r->crtype&SPECULAR)
537
538 /* distglow *
539 *
540 * A distant glow is an object that sometimes acts as a light source,
541 * but is too far away from the test point to be one in this case.
542 */
543
544 #define  distglow(m, r)         (m->otype==MAT_GLOW && \
545                                r->rot > m->oargs.farg[3])
546
547 /* badambient *
548 *
549 * We must avoid including counting light sources in the ambient calculation,
550 * since the direct component is handled separately.  Therefore, any
551 * ambient ray which hits an active light source must be discarded.
552 */
553
554 #define  badambient(m, r)       ((r->crtype&(AMBIENT|SHADOW))==AMBIENT && \
555                                !distglow(m, r))
556
557 /* overcount *
558 *
559 * All overcounting possibilities are contained here.
560 */
561
562 #define  overcount(m, r)        (badspecular(m,r) || wrongsource(m,r) || \
563                                badambient(m,r))
564
565 /* passillum *
566 *
567 * An illum passes to another material type when we didn't hit it
568 * on purpose (as part of a direct calculation), or it is relaying
569 * a virtual light source.
570 */
571
572 #define  passillum(m, r)        (m->otype==MAT_ILLUM && \
573                                (r->rsrc<0 || source[r->rsrc].so!=r->ro || \
574                                source[r->rsrc].sflags&SVIRTUAL))
575
576 /* srcignore *
577 *
578 * The -di flag renders light sources invisible, and here is the test.
579 */
580
581 #define  srcignore(m, r)        (directinvis && !(r->crtype&SHADOW) && \
582                                !distglow(m, r))
583
584
585 m_light(m, r)                   /* ray hit a light source */
586 register OBJREC  *m;
587 register RAY  *r;
588 {
589                                                /* check for over-counting */
590        if (overcount(m, r))
591                return;
592                                                /* check for passed illum */
593        if (passillum(m, r)) {
594                if (m->oargs.nsargs < 1 || !strcmp(m->oargs.sarg[0], VOIDID))
595                        raytrans(r);
596                else
597                        rayshade(r, modifier(m->oargs.sarg[0]));
598                return;
599        }
600                                        /* otherwise treat as source */
601                                                /* check for behind */
602        if (r->rod < 0.0)
603                return;
604                                                /* check for invisibility */
605        if (srcignore(m, r))
606                return;
607                                                /* get distribution pattern */
608        raytexture(r, m->omod);
609                                                /* get source color */
610        setcolor(r->rcol, m->oargs.farg[0],
611                          m->oargs.farg[1],
612                          m->oargs.farg[2]);
613                                                /* modify value */
614        multcolor(r->rcol, r->pcol);
498   }

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