--- ray/src/rt/source.c	2003/12/31 02:03:08	2.39
+++ ray/src/rt/source.c	2014/09/15 00:54:39	2.63
@@ -1,5 +1,5 @@
 #ifndef lint
-static const char RCSid[] = "$Id: source.c,v 2.39 2003/12/31 02:03:08 greg Exp $";
+static const char RCSid[] = "$Id: source.c,v 2.63 2014/09/15 00:54:39 greg Exp $";
 #endif
 /*
  *  source.c - routines dealing with illumination sources.
@@ -7,20 +7,12 @@ static const char RCSid[] = "$Id: source.c,v 2.39 2003
  *  External symbols declared in source.h
  */
 
-#include "copyright.h"
-
 #include  "ray.h"
-
 #include  "otypes.h"
-
-#include  "otspecial.h"
-
+#include  "rtotypes.h"
 #include  "source.h"
-
 #include  "random.h"
 
-extern double  ssampdist;		/* scatter sampling distance */
-
 #ifndef MAXSSAMP
 #define MAXSSAMP	16		/* maximum samples per ray */
 #endif
@@ -45,13 +37,13 @@ static CONTRIB  *srccnt;		/* source contributions in d
 static CNTPTR  *cntord;			/* source ordering in direct() */
 static int  maxcntr = 0;		/* size of contribution arrays */
 
+static int cntcmp(const void *p1, const void *p2);
 
+
 OBJREC *			/* find an object's actual material */
-findmaterial(register OBJREC *o)
+findmaterial(OBJREC *o)
 {
 	while (!ismaterial(o->otype)) {
-		if (ismixture(o->otype))
-			return(NULL);   /* reject mixed materials */
 		if (o->otype == MOD_ALIAS && o->oargs.nsargs) {
 			OBJECT  aobj;
 			OBJREC  *ao;
@@ -61,22 +53,26 @@ findmaterial(register OBJREC *o)
 			ao = objptr(aobj);
 			if (ismaterial(ao->otype))
 				return(ao);
+			if (ao->otype == MOD_ALIAS) {
+				o = ao;
+				continue;
+			}
 		}
 		if (o->omod == OVOID)
 			return(NULL);
 		o = objptr(o->omod);
 	}
-	return(o);
+	return(o);		/* mixtures will return NULL */
 }
 
 
 void
-marksources()			/* find and mark source objects */
+marksources(void)			/* find and mark source objects */
 {
 	int  foundsource = 0;
 	int  i;
-	register OBJREC  *o, *m;
-	register int  ns;
+	OBJREC  *o, *m;
+	int  ns;
 					/* initialize dispatch table */
 	initstypes();
 					/* find direct sources */
@@ -87,22 +83,29 @@ marksources()			/* find and mark source objects */
 		if (!issurface(o->otype) || o->omod == OVOID)
 			continue;
 					/* find material */
-		m = findmaterial(o);
-		if (m == NULL || !islight(m->otype))
+		m = findmaterial(objptr(o->omod));
+		if (m == NULL)
+			continue;
+		if (m->otype == MAT_CLIP) {
+			markclip(m);	/* special case for antimatter */
+			continue;
+		}
+		if (!islight(m->otype))
 			continue;	/* not source modifier */
 	
 		if (m->oargs.nfargs != (m->otype == MAT_GLOW ? 4 :
 				m->otype == MAT_SPOT ? 7 : 3))
 			objerror(m, USER, "bad # arguments");
 
-		if (m->otype == MAT_GLOW &&
-				o->otype != OBJ_SOURCE &&
-				m->oargs.farg[3] <= FTINY)
-			continue;			/* don't bother */
 		if (m->oargs.farg[0] <= FTINY && m->oargs.farg[1] <= FTINY &&
 				m->oargs.farg[2] <= FTINY)
 			continue;			/* don't bother */
-
+		if (m->otype == MAT_GLOW &&
+				o->otype != OBJ_SOURCE &&
+				m->oargs.farg[3] <= FTINY) {
+			foundsource += (ambounce > 0);
+			continue;			/* don't track these */
+		}
 		if (sfun[o->otype].of == NULL ||
 				sfun[o->otype].of->setsrc == NULL)
 			objerror(o, USER, "illegal material");
@@ -115,8 +118,10 @@ marksources()			/* find and mark source objects */
 		if (m->otype == MAT_GLOW) {
 			source[ns].sflags |= SPROX;
 			source[ns].sl.prox = m->oargs.farg[3];
-			if (source[ns].sflags & SDISTANT)
+			if (source[ns].sflags & SDISTANT) {
 				source[ns].sflags |= SSKIP;
+				foundsource += (ambounce > 0);
+			}
 		} else if (m->otype == MAT_SPOT) {
 			source[ns].sflags |= SSPOT;
 			if ((source[ns].sl.s = makespot(m)) == NULL)
@@ -129,10 +134,9 @@ marksources()			/* find and mark source objects */
 			}
 		}
 #if  SHADCACHE
-		source[ns].obscache = NULL;
+		initobscache(ns);
 #endif
-		if (!(source[ns].sflags & SSKIP))
-			foundsource++;
+		foundsource += !(source[ns].sflags & SSKIP);
 	}
 	if (!foundsource) {
 		error(WARNING, "no light sources found");
@@ -152,7 +156,7 @@ memerr:
 
 
 void
-freesources()			/* free all source structures */
+freesources(void)			/* free all source structures */
 {
 	if (nsources > 0) {
 #if SHADCACHE
@@ -163,6 +167,7 @@ freesources()			/* free all source structures */
 		source = NULL;
 		nsources = 0;
 	}
+	markclip(NULL);
 	if (maxcntr <= 0)
 		return;
 	free((void *)srccnt);
@@ -175,49 +180,52 @@ freesources()			/* free all source structures */
 
 int
 srcray(				/* send a ray to a source, return domega */
-register RAY  *sr,		/* returned source ray */
-RAY  *r,			/* ray which hit object */
-SRCINDEX  *si			/* source sample index */
+	RAY  *sr,		/* returned source ray */
+	RAY  *r,			/* ray which hit object */
+	SRCINDEX  *si			/* source sample index */
 )
 {
-    double  d;				/* distance to source */
-    register SRCREC  *srcp;
+	double  d;				/* distance to source */
+	SRCREC  *srcp;
 
-    rayorigin(sr, r, SHADOW, 1.0);		/* ignore limits */
+	rayorigin(sr, SHADOW, r, NULL);		/* ignore limits */
 
-    while ((d = nextssamp(sr, si)) != 0.0) {
-	sr->rsrc = si->sn;			/* remember source */
-	srcp = source + si->sn;
-	if (srcp->sflags & SDISTANT) {
-		if (srcp->sflags & SSPOT && spotout(sr, srcp->sl.s))
-			continue;
-		return(1);		/* sample OK */
-	}
+	if (r == NULL)
+		sr->rmax = 0.0;
+
+	while ((d = nextssamp(sr, si)) != 0.0) {
+		sr->rsrc = si->sn;			/* remember source */
+		srcp = source + si->sn;
+		if (srcp->sflags & SDISTANT) {
+			if (srcp->sflags & SSPOT && spotout(sr, srcp->sl.s))
+				continue;
+			return(1);		/* sample OK */
+		}
 				/* local source */
 						/* check proximity */
-	if (srcp->sflags & SPROX && d > srcp->sl.prox)
-		continue;
-						/* check angle */
-	if (srcp->sflags & SSPOT) {
-		if (spotout(sr, srcp->sl.s))
+		if (srcp->sflags & SPROX && d > srcp->sl.prox)
 			continue;
+						/* check angle */
+		if (srcp->sflags & SSPOT) {
+			if (spotout(sr, srcp->sl.s))
+				continue;
 					/* adjust solid angle */
-		si->dom *= d*d;
-		d += srcp->sl.s->flen;
-		si->dom /= d*d;
+			si->dom *= d*d;
+			d += srcp->sl.s->flen;
+			si->dom /= d*d;
+		}
+		return(1);			/* sample OK */
 	}
-	return(1);			/* sample OK */
-    }
-    return(0);			/* no more samples */
+	return(0);			/* no more samples */
 }
 
 
 void
 srcvalue(			/* punch ray to source and compute value */
-register RAY  *r
+	RAY  *r
 )
 {
-	register SRCREC  *sp;
+	SRCREC  *sp;
 
 	sp = &source[r->rsrc];
 	if (sp->sflags & SVIRTUAL) {	/* virtual source */
@@ -254,243 +262,99 @@ nomat:
 }
 
 
+static int
+transillum(			/* check if material is transparent illum */
+	OBJECT	obj
+)
+{
+	OBJREC *m = findmaterial(objptr(obj));
+	
+	if (m == NULL)
+		return(1);
+	if (m->otype != MAT_ILLUM)
+		return(0);
+	return(!m->oargs.nsargs || !strcmp(m->oargs.sarg[0], VOIDID));
+}
+
+
 int
 sourcehit(			/* check to see if ray hit distant source */
-register RAY  *r
+	RAY  *r
 )
 {
+	int  glowsrc = -1;
+	int  transrc = -1;
 	int  first, last;
-	register int  i;
+	int  i;
 
 	if (r->rsrc >= 0) {		/* check only one if aimed */
 		first = last = r->rsrc;
 	} else {			/* otherwise check all */
 		first = 0; last = nsources-1;
 	}
-	for (i = first; i <= last; i++)
-		if ((source[i].sflags & (SDISTANT|SVIRTUAL)) == SDISTANT)
-			/*
-			 * Check to see if ray is within
-			 * solid angle of source.
-			 */
-			if (2.0*PI * (1.0 - DOT(source[i].sloc,r->rdir))
-					<= source[i].ss2) {
-				r->ro = source[i].so;
-				if (!(source[i].sflags & SSKIP))
-					break;
-			}
-
-	if (r->ro != NULL) {
-		r->robj = objndx(r->ro);
-		for (i = 0; i < 3; i++)
-			r->ron[i] = -r->rdir[i];
-		r->rod = 1.0;
-		r->pert[0] = r->pert[1] = r->pert[2] = 0.0;
-		r->uv[0] = r->uv[1] = 0.0;
-		r->rox = NULL;
-		return(1);
+	for (i = first; i <= last; i++) {
+		if ((source[i].sflags & (SDISTANT|SVIRTUAL)) != SDISTANT)
+			continue;
+		/*
+		 * Check to see if ray is within
+		 * solid angle of source.
+		 */
+		if (2.*PI*(1. - DOT(source[i].sloc,r->rdir)) > source[i].ss2)
+			continue;
+					/* is it the only possibility? */
+		if (first == last) {
+			r->ro = source[i].so;
+			break;
+		}
+		/*
+		 * If it's a glow or transparent illum, just remember it.
+		 */
+		if (source[i].sflags & SSKIP) {
+			if (glowsrc < 0)
+				glowsrc = i;
+			continue;
+		}
+		if (transillum(source[i].so->omod)) {
+			if (transrc < 0)
+				transrc = i;
+			continue;
+		}
+		r->ro = source[i].so;	/* otherwise, use first hit */
+		break;
 	}
-	return(0);
-}
-
-
-#if  SHADCACHE			/* preemptive shadow checking */
-#define ABS(x)  ((x)>0 ? (x) : -(x))
-
-static void				/* find closest blockers to source */
-initobscache(SRCREC *srcp)
-{
-	int     i;
-	int     cachelen;
-
-	if (srcp->sflags & SDISTANT)
-		cachelen = 4*SHADCACHE*SHADCACHE;
-	else if (srcp->sflags & SFLAT)
-		cachelen = SHADCACHE*SHADCACHE*3 + (SHADCACHE&1)*SHADCACHE*4;
-	else /* spherical distribution */
-		cachelen = SHADCACHE*SHADCACHE*6;
-					/* allocate cache */
-	DCHECK(srcp->obscache != NULL,
-			CONSISTENCY, "initobscache() called twice");
-	srcp->obscache = (OBSCACHE *)malloc(sizeof(OBSCACHE) +
-						sizeof(OBJECT)*(cachelen-1));
-	if (srcp->obscache == NULL)
-		error(SYSTEM, "out of memory in initobscache()");
-					/* set parameters */
-	if (srcp->sflags & SDISTANT) {
-		int     ax, ax1, ax2;
-		RREAL   amax = 0;
-		for (ax1 = 3; ax1--; )
-			if (ABS(srcp->sloc[ax1]) > amax) {
-				amax = ABS(srcp->sloc[ax1]);
-				ax = ax1;
-			}
-		srcp->obscache->p.d.ax = ax;
-		ax1 = (ax+1)%3;
-		ax2 = (ax+2)%3;
-		VCOPY(srcp->obscache->p.d.o, thescene.cuorg);
-		if (srcp->sloc[ax] > 0)
-			srcp->obscache->p.d.o[ax] += thescene.cusize;
-		if (srcp->sloc[ax1] < 0)
-			srcp->obscache->p.d.o[ax1] += thescene.cusize *
-					srcp->sloc[ax1] / ABS(srcp->sloc[ax]);
-		if (srcp->sloc[ax2] < 0)
-			srcp->obscache->p.d.o[ax2] += thescene.cusize *
-					srcp->sloc[ax2] / ABS(srcp->sloc[ax]);
-		srcp->obscache->p.d.e1 = (1.-FTINY) / (thescene.cusize*(1. +
-				fabs(srcp->sloc[ax1]/srcp->sloc[ax])));
-		srcp->obscache->p.d.e2 = (1.-FTINY) / (thescene.cusize*(1. +
-				fabs(srcp->sloc[ax2]/srcp->sloc[ax])));
-	} else if (srcp->sflags & SFLAT) {
-		VCOPY(srcp->obscache->p.f.u, srcp->ss[SU]);
-		normalize(srcp->obscache->p.f.u);
-		fcross(srcp->obscache->p.f.v,
-				srcp->snorm, srcp->obscache->p.f.u);
+	/*
+	 * Do we need fallback?
+	 */
+	if (r->ro == NULL) {
+		if (transrc >= 0 && r->crtype & (AMBIENT|SPECULAR))
+			return(0);	/* avoid overcounting */
+		if (glowsrc >= 0)
+			r->ro = source[glowsrc].so;
+		else
+			return(0);	/* nothing usable */
 	}
-					/* XXX Should cast rays from source */
-	for (i = cachelen; i--; )
-		srcp->obscache->obs[i] = OVOID;
+	/*
+	 * Make assignments.
+	 */
+	r->robj = objndx(r->ro);
+	for (i = 0; i < 3; i++)
+		r->ron[i] = -r->rdir[i];
+	r->rod = 1.0;
+	r->pert[0] = r->pert[1] = r->pert[2] = 0.0;
+	r->uv[0] = r->uv[1] = 0.0;
+	r->rox = NULL;
+	return(1);
 }
 
 
-static OBJECT *			/* return occluder cache entry */
-srcobstructp(register RAY *r)
-{
-	static OBJECT   noobs;
-	SRCREC		*srcp;
-	int		ondx;
-
-	DCHECK(r->rsrc < 0, CONSISTENCY,
-			"srcobstructp() called with unaimed ray");
-	noobs = OVOID;
-	srcp = &source[r->rsrc];
-	if (srcp->obscache == NULL)     /* initialize cache */
-		initobscache(srcp);
-					/* compute cache index */
-	if (srcp->sflags & SDISTANT) {
-		int     ax, ax1, ax2;
-		double  t;
-		ax = srcp->obscache->p.d.ax;
-		if ((ax1 = ax+1) >= 3) ax1 -= 3;
-		if ((ax2 = ax+2) >= 3) ax2 -= 3;
-		t = (srcp->obscache->p.d.o[ax] - r->rorg[ax]) / srcp->sloc[ax];
-		if (t <= FTINY)
-			return &noobs;  /* could happen if ray is outside */
-		ondx = 2*SHADCACHE*(int)(2*SHADCACHE*srcp->obscache->p.d.e1 *
-				(r->rorg[ax1] + t*srcp->sloc[ax1] -
-					srcp->obscache->p.d.o[ax1]));
-		ondx += (int)(2*SHADCACHE*srcp->obscache->p.d.e2 *
-				(r->rorg[ax2] + t*srcp->sloc[ax2] -
-					srcp->obscache->p.d.o[ax2]));
-		if (ondx < 0 | ondx >= 4*SHADCACHE*SHADCACHE)
-			return &nobs;   /* could happen if ray is outside */
-	} else if (srcp->sflags & SFLAT) {
-		FVECT   sd;
-		RREAL   sd0m, sd1m;
-		sd[0] = -DOT(r->rdir, srcp->obscache->p.f.u);
-		sd[1] = -DOT(r->rdir, srcp->obscache->p.f.v);
-		sd[2] = -DOT(r->rdir, srcp->snorm);
-		if (sd[2] < 0)
-			return &noobs;  /* shouldn't happen */
-		sd0m = ABS(sd[0]);
-		sd1m = ABS(sd[1]);
-		if (sd[2] >= sd0m && sd[2] >= sd1m) {
-			ondx = SHADCACHE*(int)(SHADCACHE*(.5-FTINY) *
-					(1. + sd[0]/sd[2]));
-			ondx += (int)(SHADCACHE*(.5-FTINY) *
-					(1. + sd[1]/sd[2]));
-		} else if (sd0m >= sd1m) {
-			ondx = SHADCACHE*SHADCACHE;
-			if (sd[0] < 0)
-				ondx += ((SHADCACHE+1)>>1)*SHADCACHE;
-			ondx += SHADCACHE*(int)(SHADCACHE*(.5-FTINY) *
-					sd[2]/sd0m);
-			ondx += (int)(SHADCACHE*(.5-FTINY) *
-					(1. + sd[1]/sd0m));
-		} else /* sd1m > sd0m */ {
-			ondx = SHADCACHE*SHADCACHE +
-					((SHADCACHE+1)>>1)*SHADCACHE*2;
-			if (sd[1] < 0)
-				ondx += ((SHADCACHE+1)>>1)*SHADCACHE;
-			ondx += SHADCACHE*(int)(SHADCACHE*(.5-FTINY) *
-					sd[2]/sd1m);
-			ondx += (int)(SHADCACHE*(.5-FTINY) *
-					(1. + sd[0]/sd1m));
-		}
-	} else /* spherical distribution */ {
-		int     ax, ax1, ax2;
-		RREAL   amax = 0;
-		for (ax1 = 3; ax1--; )
-			if (ABS(r->rdir[ax1]) > amax) {
-				amax = ABS(r->rdir[ax1]);
-				ax = ax1;
-			}
-		if ((ax1 = ax+1) >= 3) ax1 -= 3;
-		if ((ax2 = ax+2) >= 3) ax2 -= 3;
-		ondx = 2*SHADCACHE*SHADCACHE * ax;
-		if (r->rdir[ax] < 0)
-			ondx += SHADCACHE*SHADCACHE;
-		ondx += SHADCACHE*(int)(SHADCACHE*(.5-FTINY) *
-					(1. + r->rdir[ax1]/amax));
-		ondx += (int)(SHADCACHE*(.5-FTINY) *
-				(1. + r->rdir[ax2]/amax));
-	}
-					/* return cache pointer */
-	return(&srcp->obscache->obs[ondx]);
-}
-
-
-void				/* free obstruction cache */
-freeobscache(SRCREC *srcp)
-{
-	if (srcp->obscache == NULL)
-		return;
-	free((void *)srcp->obscache);
-	srcp->obscache = NULL;
-}
-
-	
-void				/* record a source blocker */
-srcblocker(register RAY *r)
-{
-	OBJREC  *m;
-
-	if (r->robj == OVOID || objptr(r->robj) != r->ro ||
-			isvolume(r->ro->otype))
-		return;			/* don't record complex blockers */
-	m = findmaterial(r->ro);
-	if (m == NULL)
-		return;			/* no material?! */
-	if (!(ofun[m->otype].flags & T_OPAQUE))
-		return;			/* material not a reliable blocker */
-
-	*srcobstructp(r) = r->robj;     /* else record obstructor */
-}
-
-
-int				/* check ray against cached blocker */
-srcblocked(RAY *r)
-{
-	OBJECT  obs = *srcobstructp(r);
-	OBJREC  *op;
-
-	if (obs == OVOID)
-		return(0);
-	op = objptr(obs);		/* check for intersection */
-	return ((*ofun[op->otype].funp)(op, r));
-}
-
-#endif
-
-
 static int
 cntcmp(				/* contribution compare (descending) */
-const void *p1,
-const void *p2
+	const void *p1,
+	const void *p2
 )
 {
-	register const CNTPTR  *sc1 = (const CNTPTR *)p1;
-	register const CNTPTR  *sc2 = (const CNTPTR *)p2;
+	const CNTPTR  *sc1 = (const CNTPTR *)p1;
+	const CNTPTR  *sc2 = (const CNTPTR *)p2;
 
 	if (sc1->brt > sc2->brt)
 		return(-1);
@@ -502,14 +366,13 @@ const void *p2
 
 void
 direct(					/* add direct component */
-RAY  *r,			/* ray that hit surface */
-void  (*f)(),			/* direct component coefficient function */
-char  *p			/* data for f */
+	RAY  *r,			/* ray that hit surface */
+	srcdirf_t *f,			/* direct component coefficient function */
+	void  *p			/* data for f */
 )
 {
-	extern void  (*trace)();
-	register int  sn;
-	register CONTRIB  *scp;
+	int  sn;
+	CONTRIB  *scp;
 	SRCINDEX  si;
 	int  nshadcheck, ncnts;
 	int  nhits;
@@ -535,7 +398,7 @@ char  *p			/* data for f */
 		scp->sno = sr.rsrc;
 						/* compute coefficient */
 		(*f)(scp->coef, p, sr.rdir, si.dom);
-		cntord[sn].brt = bright(scp->coef);
+		cntord[sn].brt = intens(scp->coef);
 		if (cntord[sn].brt <= 0.0)
 			continue;
 #if SHADCACHE
@@ -546,17 +409,18 @@ char  *p			/* data for f */
 		}
 #endif
 		VCOPY(scp->dir, sr.rdir);
+		copycolor(sr.rcoef, scp->coef);
 						/* compute potential */
 		sr.revf = srcvalue;
 		rayvalue(&sr);
+		multcolor(sr.rcol, sr.rcoef);
 		copycolor(scp->val, sr.rcol);
-		multcolor(scp->val, scp->coef);
-		cntord[sn].brt = bright(scp->val);
+		cntord[sn].brt = bright(sr.rcol);
 	}
 						/* sort contributions */
 	qsort(cntord, sn, sizeof(CNTPTR), cntcmp);
 	{					/* find last */
-		register int  l, m;
+		int  l, m;
 
 		ncnts = l = sn;
 		sn = 0;
@@ -576,7 +440,10 @@ char  *p			/* data for f */
 						/* compute number to check */
 	nshadcheck = pow((double)ncnts, shadcert) + .5;
 						/* modify threshold */
-	ourthresh = shadthresh / r->rweight;
+	if (ncnts > MINSHADCNT)
+		ourthresh = shadthresh / r->rweight;
+	else
+		ourthresh = 0;
 						/* test for shadows */
 	for (nhits = 0, hwt = 0.0, sn = 0; sn < ncnts;
 			hwt += (double)source[scp->sno].nhits /
@@ -589,7 +456,8 @@ char  *p			/* data for f */
 			break;
 		scp = srccnt + cntord[sn].sndx;
 						/* test for hit */
-		rayorigin(&sr, r, SHADOW, 1.0);
+		rayorigin(&sr, SHADOW, r, NULL);
+		copycolor(sr.rcoef, scp->coef);
 		VCOPY(sr.rdir, scp->dir);
 		sr.rsrc = scp->sno;
 						/* keep statistics */
@@ -602,20 +470,26 @@ char  *p			/* data for f */
 				source[scp->sno].sflags & SFOLLOW )) {
 						/* follow entire path */
 			raycont(&sr);
-			rayparticipate(&sr);
 			if (trace != NULL)
 				(*trace)(&sr);	/* trace execution */
 			if (bright(sr.rcol) <= FTINY) {
 #if SHADCACHE
 				if ((scp <= srccnt || scp[-1].sno != scp->sno)
-						&& (scp >= srccnt+ncnts ||
+						&& (scp >= srccnt+ncnts-1 ||
 						    scp[1].sno != scp->sno))
 					srcblocker(&sr);
 #endif
 				continue;	/* missed! */
 			}
+			rayparticipate(&sr);
+			multcolor(sr.rcol, sr.rcoef);
 			copycolor(scp->val, sr.rcol);
-			multcolor(scp->val, scp->coef);
+		} else if (trace != NULL &&
+			(source[scp->sno].sflags & (SDISTANT|SVIRTUAL|SFOLLOW))
+						== (SDISTANT|SFOLLOW) &&
+				sourcehit(&sr) && rayshade(&sr, sr.ro->omod)) {
+			(*trace)(&sr);		/* trace execution */
+			/* skip call to rayparticipate() & scp->val update */
 		}
 						/* add contribution if hit */
 		addcolor(r->rcol, scp->val);
@@ -637,9 +511,8 @@ char  *p			/* data for f */
 		scp = srccnt + cntord[sn].sndx;
 		prob = hwt * (double)source[scp->sno].nhits /
 				(double)source[scp->sno].ntests;
-		if (prob > 1.0)
-			prob = 1.0;
-		scalecolor(scp->val, prob);
+		if (prob < 1.0)
+			scalecolor(scp->val, prob);
 		addcolor(r->rcol, scp->val);
 	}
 }
@@ -647,7 +520,7 @@ char  *p			/* data for f */
 
 void
 srcscatter(			/* compute source scattering into ray */
-register RAY  *r
+	RAY  *r
 )
 {
 	int  oldsampndx;
@@ -686,20 +559,27 @@ register RAY  *r
 			sr.rorg[0] = r->rorg[0] + r->rdir[0]*t;
 			sr.rorg[1] = r->rorg[1] + r->rdir[1]*t;
 			sr.rorg[2] = r->rorg[2] + r->rdir[2]*t;
-			sr.rmax = 0.;
 			initsrcindex(&si);	/* sample ray to this source */
 			si.sn = r->slights[i];
 			nopart(&si, &sr);
 			if (!srcray(&sr, NULL, &si) ||
 					sr.rsrc != r->slights[i])
 				continue;		/* no path */
+#if SHADCACHE
+			if (srcblocked(&sr))		/* check shadow cache */
+				continue;
+#endif
 			copycolor(sr.cext, r->cext);
 			copycolor(sr.albedo, r->albedo);
 			sr.gecc = r->gecc;
 			sr.slights = r->slights;
 			rayvalue(&sr);			/* eval. source ray */
-			if (bright(sr.rcol) <= FTINY)
+			if (bright(sr.rcol) <= FTINY) {
+#if SHADCACHE
+				srcblocker(&sr);	/* add blocker to cache */
+#endif
 				continue;
+			}
 			if (r->gecc <= FTINY)		/* compute P(theta) */
 				d = 1.;
 			else {
@@ -737,13 +617,12 @@ register RAY  *r
  */
 
 static int
-weaksrcmat(int obj)		/* identify material */
+weaksrcmat(OBJECT obj)		/* identify material */
 {
-	register OBJREC *o = objptr(obj);
+	OBJREC *m = findmaterial(objptr(obj));
 	
-	while (!ismaterial(o->otype))	/* find material */
-		o = objptr(o->omod);
-	return((o->otype==MAT_ILLUM)|(o->otype==MAT_GLOW));
+	if (m == NULL) return(0);
+	return((m->otype==MAT_ILLUM) | (m->otype==MAT_GLOW));
 }
 
 #define  illumblock(m, r)	(!(source[r->rsrc].sflags&SVIRTUAL) && \
@@ -806,15 +685,19 @@ weaksrcmat(int obj)		/* identify material */
 
 int
 m_light(				/* ray hit a light source */
-register OBJREC  *m,
-register RAY  *r
+	OBJREC  *m,
+	RAY  *r
 )
 {
 						/* check for over-counting */
-	if (badcomponent(m, r))
+	if (badcomponent(m, r)) {
+		setcolor(r->rcoef, 0.0, 0.0, 0.0);
 		return(1);
-	if (wrongsource(m, r))
+	}
+	if (wrongsource(m, r)) {
+		setcolor(r->rcoef, 0.0, 0.0, 0.0);
 		return(1);
+	}
 						/* check for passed illum */
 	if (passillum(m, r)) {
 		if (m->oargs.nsargs && strcmp(m->oargs.sarg[0], VOIDID))
@@ -822,12 +705,14 @@ register RAY  *r
 		raytrans(r);
 		return(1);
 	}
+						/* check for invisibility */
+	if (srcignore(m, r)) {
+		setcolor(r->rcoef, 0.0, 0.0, 0.0);
+		return(1);
+	}
 					/* otherwise treat as source */
 						/* check for behind */
 	if (r->rod < 0.0)
-		return(1);
-						/* check for invisibility */
-	if (srcignore(m, r))
 		return(1);
 						/* check for outside spot */
 	if (m->otype==MAT_SPOT && spotout(r, makespot(m)))