--- ray/src/rt/virtuals.c	1991/06/24 16:10:59	1.7
+++ ray/src/rt/virtuals.c	2003/07/21 22:30:19	2.11
@@ -1,33 +1,32 @@
-/* Copyright (c) 1991 Regents of the University of California */
-
 #ifndef lint
-static char SCCSid[] = "$SunId$ LBL";
+static const char	RCSid[] = "$Id: virtuals.c,v 2.11 2003/07/21 22:30:19 schorsch Exp $";
 #endif
-
 /*
  * Routines for simulating virtual light sources
  *	Thus far, we only support planar mirrors.
+ *
+ *  External symbols declared in source.h
  */
 
+#include "copyright.h"
+
 #include  "ray.h"
 
-#include  "octree.h"
-
 #include  "otypes.h"
 
 #include  "source.h"
 
 #include  "random.h"
 
+#define  MINSAMPLES	16		/* minimum number of pretest samples */
+#define  STESTMAX	32		/* maximum seeks per sample */
 
-#define  DISKTFRAC	0.25		/* disk area pretest fraction */
 
-double  getdisk();
-
 static OBJECT  *vobject;		/* virtual source objects */
 static int  nvobjects = 0;		/* number of virtual source objects */
 
 
+void
 markvirtuals()			/* find and mark virtual sources */
 {
 	register OBJREC  *o;
@@ -36,19 +35,21 @@ markvirtuals()			/* find and mark virtual sources */
 	if (directrelay <= 0)
 		return;
 					/* find virtual source objects */
-	for (i = 0; i < nobjects; i++) {
+	for (i = 0; i < nsceneobjs; i++) {
 		o = objptr(i);
 		if (!issurface(o->otype) || o->omod == OVOID)
 			continue;
-		if (!isvlight(objptr(o->omod)->otype))
+		if (!isvlight(vsmaterial(o)->otype))
 			continue;
 		if (sfun[o->otype].of == NULL ||
-				sfun[o->otype].of->getpleq == NULL)
-			objerror(o, USER, "illegal material");
+				sfun[o->otype].of->getpleq == NULL) {
+			objerror(o,WARNING,"secondary sources not supported");
+			continue;
+		}
 		if (nvobjects == 0)
 			vobject = (OBJECT *)malloc(sizeof(OBJECT));
 		else
-			vobject = (OBJECT *)realloc((char *)vobject,
+			vobject = (OBJECT *)realloc((void *)vobject,
 				(unsigned)(nvobjects+1)*sizeof(OBJECT));
 		if (vobject == NULL)
 			error(SYSTEM, "out of memory in addvirtuals");
@@ -63,11 +64,12 @@ markvirtuals()			/* find and mark virtual sources */
 	for (i = nsources; i-- > 0; )
 		addvirtuals(i, directrelay);
 					/* done with our object list */
-	free((char *)vobject);
+	free((void *)vobject);
 	nvobjects = 0;
 }
 
 
+void
 addvirtuals(sn, nr)		/* add virtuals associated with source */
 int  sn;
 int  nr;
@@ -85,6 +87,7 @@ int  nr;
 }
 
 
+void
 vproject(o, sn, n)		/* create projected source(s) if they exist */
 OBJREC  *o;
 int  sn;
@@ -98,11 +101,12 @@ int  n;
 	if (o == source[sn].so)	/* objects cannot project themselves */
 		return;
 				/* get virtual source material */
-	vsmat = sfun[objptr(o->omod)->otype].mf;
+	vsmat = sfun[vsmaterial(o)->otype].mf;
 				/* project virtual sources */
 	for (i = 0; i < vsmat->nproj; i++)
 		if ((*vsmat->vproj)(proj, o, &source[sn], i))
 			if ((ns = makevsrc(o, sn, proj)) >= 0) {
+				source[ns].sa.sv.pn = i;
 #ifdef DEBUG
 				virtverb(ns, stderr);
 #endif
@@ -111,16 +115,32 @@ int  n;
 }
 
 
+OBJREC *
+vsmaterial(o)			/* get virtual source material pointer */
+OBJREC  *o;
+{
+	register int  i;
+	register OBJREC  *m;
+
+	i = o->omod;
+	m = objptr(i);
+	if (m->otype != MAT_ILLUM || m->oargs.nsargs < 1 ||
+			!strcmp(m->oargs.sarg[0], VOIDID) ||
+			(i = lastmod(objndx(m), m->oargs.sarg[0])) == OVOID)
+		return(m);		/* direct modifier */
+	return(objptr(i));		/* illum alternate */
+}
+
+
 int
 makevsrc(op, sn, pm)		/* make virtual source if reasonable */
 OBJREC  *op;
 register int  sn;
 MAT4  pm;
 {
-	FVECT  nsloc, nsnorm, ocent;
-	double  maxrad2;
+	FVECT  nsloc, nsnorm, ocent, v;
+	double  maxrad2, d;
 	int  nsflags;
-	double  d1;
 	SPOT  theirspot, ourspot;
 	register int  i;
 
@@ -134,35 +154,73 @@ MAT4  pm;
 		if (source[sn].sflags & SPROX)
 			return(-1);		/* should never get here! */
 		multv3(nsloc, source[sn].sloc, pm);
+		normalize(nsloc);
 		VCOPY(ourspot.aim, ocent);
 		ourspot.siz = PI*maxrad2;
-		ourspot.flen = 0.;
+		ourspot.flen = -1.;
 		if (source[sn].sflags & SSPOT) {
-			copystruct(&theirspot, source[sn].sl.s);
 			multp3(theirspot.aim, source[sn].sl.s->aim, pm);
+						/* adjust for source size */
+			d = sqrt(dist2(ourspot.aim, theirspot.aim));
+			d = sqrt(source[sn].sl.s->siz/PI) + d*source[sn].srad;
+			theirspot.siz = PI*d*d;
+			ourspot.flen = theirspot.flen = source[sn].sl.s->flen;
+			d = ourspot.siz;
 			if (!commonbeam(&ourspot, &theirspot, nsloc))
-				return(-1);		/* no overlap */
+				return(-1);	/* no overlap */
+			if (ourspot.siz < d-FTINY) {	/* it shrunk */
+				d = beamdisk(v, op, &ourspot, nsloc);
+				if (d <= FTINY)
+					return(-1);
+				if (d < maxrad2) {
+					maxrad2 = d;
+					VCOPY(ocent, v);
+				}
+			}
 		}
 	} else {				/* local source */
 		multp3(nsloc, source[sn].sloc, pm);
 		for (i = 0; i < 3; i++)
 			ourspot.aim[i] = ocent[i] - nsloc[i];
-		if ((d1 = normalize(ourspot.aim)) == 0.)
+		if ((d = normalize(ourspot.aim)) == 0.)
 			return(-1);		/* at source!! */
-		if (source[sn].sflags & SPROX && d1 > source[sn].sl.prox)
+		if (source[sn].sflags & SPROX && d > source[sn].sl.prox)
 			return(-1);		/* too far away */
-		ourspot.siz = 2.*PI*(1. - d1/sqrt(d1*d1+maxrad2));
 		ourspot.flen = 0.;
+						/* adjust for source size */
+		d = (sqrt(maxrad2) + source[sn].srad) / d;
+		if (d < 1.-FTINY)
+			ourspot.siz = 2.*PI*(1. - sqrt(1.-d*d));
+		else
+			nsflags &= ~SSPOT;
 		if (source[sn].sflags & SSPOT) {
-			copystruct(&theirspot, source[sn].sl.s);
+			theirspot = *(source[sn].sl.s);
 			multv3(theirspot.aim, source[sn].sl.s->aim, pm);
-			if (!commonspot(&ourspot, &theirspot, nsloc))
-				return(-1);	/* no overlap */
-			ourspot.flen = theirspot.flen;
+			normalize(theirspot.aim);
+			if (nsflags & SSPOT) {
+				ourspot.flen = theirspot.flen;
+				d = ourspot.siz;
+				if (!commonspot(&ourspot, &theirspot, nsloc))
+					return(-1);	/* no overlap */
+			} else {
+				nsflags |= SSPOT;
+				ourspot = theirspot;
+				d = 2.*ourspot.siz;
+			}
+			if (ourspot.siz < d-FTINY) {	/* it shrunk */
+				d = spotdisk(v, op, &ourspot, nsloc);
+				if (d <= FTINY)
+					return(-1);
+				if (d < maxrad2) {
+					maxrad2 = d;
+					VCOPY(ocent, v);
+				}
+			}
 		}
 		if (source[sn].sflags & SFLAT) {	/* behind source? */
 			multv3(nsnorm, source[sn].snorm, pm);
-			if (checkspot(&ourspot, nsnorm) < 0)
+			normalize(nsnorm);
+			if (nsflags & SSPOT && !checkspot(&ourspot, nsnorm))
 				return(-1);
 		}
 	}
@@ -175,15 +233,22 @@ MAT4  pm;
 		goto memerr;
 	source[i].sflags = nsflags;
 	VCOPY(source[i].sloc, nsloc);
+	multv3(source[i].ss[SU], source[sn].ss[SU], pm);
+	multv3(source[i].ss[SV], source[sn].ss[SV], pm);
 	if (nsflags & SFLAT)
 		VCOPY(source[i].snorm, nsnorm);
-	source[i].ss = source[sn].ss; source[i].ss2 = source[sn].ss2;
-	if ((source[i].sl.s = (SPOT *)malloc(sizeof(SPOT))) == NULL)
-		goto memerr;
-	copystruct(source[i].sl.s, &ourspot);
+	else
+		multv3(source[i].ss[SW], source[sn].ss[SW], pm);
+	source[i].srad = source[sn].srad;
+	source[i].ss2 = source[sn].ss2;
+	if (nsflags & SSPOT) {
+		if ((source[i].sl.s = (SPOT *)malloc(sizeof(SPOT))) == NULL)
+			goto memerr;
+		*(source[i].sl.s) = ourspot;
+	}
 	if (nsflags & SPROX)
 		source[i].sl.prox = source[sn].sl.prox;
-	source[i].sa.svnext = sn;
+	source[i].sa.sv.sn = sn;
 	source[i].so = op;
 	return(i);
 memerr:
@@ -200,11 +265,11 @@ register int  sn;
 	double  rad2, roffs, offs, d, rd, rdoto;
 	FVECT  rnrm, nrm;
 				/* first, use object getdisk function */
-	rad2 = (*sfun[op->otype].of->getdisk)(oc, op);
+	rad2 = getmaxdisk(oc, op);
 	if (!(source[sn].sflags & SVIRTUAL))
 		return(rad2);		/* all done for normal source */
 				/* check for correct side of relay surface */
-	roffs = (*sfun[source[sn].so->otype].of->getpleq)(rnrm, source[sn].so);
+	roffs = getplaneq(rnrm, source[sn].so);
 	rd = DOT(rnrm, source[sn].sloc);	/* source projection */
 	if (!(source[sn].sflags & SDISTANT))
 		rd -= roffs;
@@ -212,9 +277,9 @@ register int  sn;
 	if ((d > 0.) ^ (rd > 0.))
 		return(rad2);		/* OK if opposite sides */
 	if (d*d >= rad2)
-		return(.0);		/* no relay is possible */
+		return(0.);		/* no relay is possible */
 				/* we need a closer look */
-	offs = (*sfun[op->otype].of->getpleq)(nrm, op);
+	offs = getplaneq(nrm, op);
 	rdoto = DOT(rnrm, nrm);
 	if (d*d >= rad2*(1.-rdoto*rdoto))
 		return(0.);		/* disk entirely on projection side */
@@ -234,60 +299,103 @@ register int  sn;	/* target source number */
 	RAY  sr;
 	FVECT  onorm;
 	FVECT  offsdir;
+	SRCINDEX  si;
 	double  or, d;
-	int  nok, nhit;
+	int  stestlim, ssn;
+	int  nhit, nok;
 	register int  i, n;
 				/* return if pretesting disabled */
 	if (vspretest <= 0)
 		return(f);
 				/* get surface normal */
-	(*sfun[o->otype].of->getpleq)(onorm, o);
+	getplaneq(onorm, o);
 				/* set number of rays to sample */
-	if (source[sn].sflags & SDISTANT)
-		n = (2./3.*PI*PI)*or2/(thescene.cusize*thescene.cusize)*
-				vspretest + .5;
-	else
-		n = or2/dist2(oc,source[sn].sloc)*vspretest + .5;
-	if (n < 1) n = 1;
-				/* limit tests to central region */
-	or = DISKTFRAC*sqrt(or2);
+	if (source[sn].sflags & SDISTANT) {
+					/* 32. == heuristic constant */
+		n = 32.*or2/(thescene.cusize*thescene.cusize)*vspretest + .5;
+	} else {
+		for (i = 0; i < 3; i++)
+			offsdir[i] = source[sn].sloc[i] - oc[i];
+		d = DOT(offsdir,offsdir);
+		if (d <= FTINY)
+			n = 2.*PI * vspretest + .5;
+		else
+			n = 2.*PI * (1.-sqrt(1./(1.+or2/d)))*vspretest + .5;
+	}
+	if (n < MINSAMPLES) n = MINSAMPLES;
+#ifdef DEBUG
+	fprintf(stderr, "pretesting source %d in object %s with %d rays\n",
+			sn, o->oname, n);
+#endif
 				/* sample */
+	or = sqrt(or2);
+	stestlim = n*STESTMAX;
+	ssn = 0;
 	nhit = nok = 0;
+	initsrcindex(&si);
 	while (n-- > 0) {
-		samplendx++;
-		/*
-		 * We're being real sloppy with our sample locations here.
-		 */
-		for (i = 0; i < 3; i++)
-			offsdir[i] = or*(1. - 2.*urand(931*i+5821+n));
-		d = DOT(offsdir,onorm);
-		for (i = 0; i < 3; i++)
-			sr.rorg[i] = oc[i] + (1.-d)*offsdir[i];
+					/* get sample point */
+		do {
+			if (ssn >= stestlim) {
+#ifdef DEBUG
+				fprintf(stderr, "\ttoo hard to hit\n");
+#endif
+				return(f);	/* too small a target! */
+			}
+			multisamp(offsdir, 3, urand(sn*931+5827+ssn));
+			for (i = 0; i < 3; i++)
+				offsdir[i] = or*(1. - 2.*offsdir[i]);
+			ssn++;
+			d = 1. - DOT(offsdir, onorm);
+			for (i = 0; i < 3; i++) {
+				sr.rorg[i] = oc[i] + offsdir[i] + d*onorm[i];
+				sr.rdir[i] = -onorm[i];
+			}
+			sr.rmax = 0.0;
+			rayorigin(&sr, NULL, PRIMARY, 1.0);
+		} while (!(*ofun[o->otype].funp)(o, &sr));
 					/* check against source */
-		if (srcray(&sr, NULL, sn) == 0.0)
-			continue;
+		VCOPY(sr.rorg, sr.rop);	/* starting from intersection */
+		samplendx++;
+		if (si.sp >= si.np-1 ||
+				!srcray(&sr, NULL, &si) || sr.rsrc != sn) {
+			si.sn = sn-1;		/* reset index to our source */
+			si.np = 0;
+			if (!srcray(&sr, NULL, &si) || sr.rsrc != sn)
+				continue;	/* can't get there from here */
+		}
 		sr.revf = srcvalue;
-		rayvalue(&sr);
+		rayvalue(&sr);			/* check sample validity */
 		if (bright(sr.rcol) <= FTINY)
 			continue;
-		nok++;
-					/* check against obstructions */
-		srcray(&sr, NULL, sn);
+		nok++;			/* got sample; check obstructions */
+		rayclear(&sr);
+		sr.revf = raytrace;
 		rayvalue(&sr);
-		if (bright(sr.rcol) <= FTINY)
-			continue;
-		nhit++;
+		if (bright(sr.rcol) > FTINY)
+			nhit++;
+		if (nhit > 0 && nhit < nok) {
+#ifdef DEBUG
+			fprintf(stderr, "\tpartially occluded\n");
+#endif
+			return(f);		/* need to shadow test */
+		}
 	}
-				/* interpret results */
-	if (nhit == 0)
+	if (nhit == 0) {
+#ifdef DEBUG
+		fprintf(stderr, "\t0%% hit rate\n");
+#endif
 		return(f | SSKIP);	/* 0% hit rate:  totally occluded */
-	if (nhit == nok)
-		return(f & ~SFOLLOW);	/* 100% hit rate:  no occlusion */
-	return(f);		/* no comment */
+	}
+#ifdef DEBUG
+	fprintf(stderr, "\t100%% hit rate\n");
+#endif
+	return(f & ~SFOLLOW);		/* 100% hit rate:  no occlusion */
 }
 	
 
 #ifdef DEBUG
+void
 virtverb(sn, fp)	/* print verbose description of virtual source */
 register int  sn;
 FILE  *fp;
@@ -301,7 +409,7 @@ FILE  *fp;
 	fprintf(fp, "\tat (%f,%f,%f)\n",
 		source[sn].sloc[0], source[sn].sloc[1], source[sn].sloc[2]);
 	fprintf(fp, "\tlinked to source %d (%s)\n",
-		source[sn].sa.svnext, source[source[sn].sa.svnext].so->oname);
+		source[sn].sa.sv.sn, source[source[sn].sa.sv.sn].so->oname);
 	if (source[sn].sflags & SFOLLOW)
 		fprintf(fp, "\talways followed\n");
 	else