--- ray/src/rt/source.c	1989/06/07 10:29:05	1.6
+++ ray/src/rt/source.c	1991/10/21 14:23:36	1.46
@@ -1,4 +1,4 @@
-/* Copyright (c) 1986 Regents of the University of California */
+/* Copyright (c) 1991 Regents of the University of California */
 
 #ifndef lint
 static char SCCSid[] = "$SunId$ LBL";
@@ -14,42 +14,49 @@ static char SCCSid[] = "$SunId$ LBL";
 
 #include  "octree.h"
 
-#include  "source.h"
-
 #include  "otypes.h"
 
-#include  "cone.h"
+#include  "source.h"
 
-#include  "face.h"
+/*
+ * Structures used by direct()
+ */
 
-#include  "random.h"
+typedef struct {
+	int  sno;		/* source number */
+	FVECT  dir;		/* source direction */
+	COLOR  coef;		/* material coefficient */
+	COLOR  val;		/* contribution */
+}  CONTRIB;		/* direct contribution */
 
+typedef struct {
+	int  sndx;		/* source index (to CONTRIB array) */
+	float  brt;		/* brightness (for comparison) */
+}  CNTPTR;		/* contribution pointer */
 
-extern double  dstrsrc;			/* source distribution amount */
-extern double  shadthresh;		/* relative shadow threshold */
+static CONTRIB  *srccnt;		/* source contributions in direct() */
+static CNTPTR  *cntord;			/* source ordering in direct() */
+static int  maxcntr = 0;		/* size of contribution arrays */
 
-SRCREC  *source = NULL;			/* our list of sources */
-int  nsources = 0;			/* the number of sources */
 
-
 marksources()			/* find and mark source objects */
 {
+	int  i;
 	register OBJREC  *o, *m;
-	register int  i;
-
+	register int  ns;
+					/* initialize dispatch table */
+	initstypes();
+					/* find direct sources */
 	for (i = 0; i < nobjects; i++) {
 	
 		o = objptr(i);
 
-		if (o->omod == OVOID)
+		if (!issurface(o->otype) || o->omod == OVOID)
 			continue;
 
 		m = objptr(o->omod);
 
-		if (m->otype != MAT_LIGHT &&
-				m->otype != MAT_ILLUM &&
-				m->otype != MAT_GLOW &&
-				m->otype != MAT_SPOT)
+		if (!islight(m->otype))
 			continue;
 	
 		if (m->oargs.nfargs != (m->otype == MAT_GLOW ? 4 :
@@ -61,232 +68,132 @@ marksources()			/* find and mark source objects */
 				m->oargs.farg[3] <= FTINY)
 			continue;			/* don't bother */
 
-		if (source == NULL)
-			source = (SRCREC *)malloc(sizeof(SRCREC));
-		else
-			source = (SRCREC *)realloc((char *)source,
-					(unsigned)(nsources+1)*sizeof(SRCREC));
-		if (source == NULL)
-			error(SYSTEM, "out of memory in marksources");
+		if (sfun[o->otype].of == NULL ||
+				sfun[o->otype].of->setsrc == NULL)
+			objerror(o, USER, "illegal material");
 
-		newsource(&source[nsources], o);
+		if ((ns = newsource()) < 0)
+			goto memerr;
 
+		setsource(&source[ns], o);
+
 		if (m->otype == MAT_GLOW) {
-			source[nsources].sflags |= SPROX;
-			source[nsources].sl.prox = m->oargs.farg[3];
+			source[ns].sflags |= SPROX;
+			source[ns].sl.prox = m->oargs.farg[3];
 			if (o->otype == OBJ_SOURCE)
-				source[nsources].sflags |= SSKIP;
+				source[ns].sflags |= SSKIP;
 		} else if (m->otype == MAT_SPOT) {
-			source[nsources].sflags |= SSPOT;
-			source[nsources].sl.s = makespot(m);
+			source[ns].sflags |= SSPOT;
+			if ((source[ns].sl.s = makespot(m)) == NULL)
+				goto memerr;
+			if (source[ns].sflags & SFLAT &&
+				!checkspot(source[ns].sl.s,source[ns].snorm)) {
+				objerror(o, WARNING,
+					"invalid spotlight direction");
+				source[ns].sflags |= SSKIP;
+			}
 		}
-		nsources++;
 	}
-}
-
-
-newsource(src, so)			/* add a source to the array */
-register SRCREC  *src;
-register OBJREC  *so;
-{
-	double  cos(), tan(), sqrt();
-	double  theta;
-	FACE  *f;
-	CONE  *co;
-	int  j;
-	register int  i;
-	
-	src->sflags = 0;
-	src->nhits = 1; src->ntests = 2;	/* start probability = 1/2 */
-	src->so = so;
-
-	switch (so->otype) {
-	case OBJ_SOURCE:
-		if (so->oargs.nfargs != 4)
-			objerror(so, USER, "bad arguments");
-		src->sflags |= SDISTANT;
-		VCOPY(src->sloc, so->oargs.farg);
-		if (normalize(src->sloc) == 0.0)
-			objerror(so, USER, "zero direction");
-		theta = PI/180.0/2.0 * so->oargs.farg[3];
-		if (theta <= FTINY)
-			objerror(so, USER, "zero size");
-		src->ss = theta >= PI/4 ? 1.0 : tan(theta);
-		src->ss2 = 2.0*PI * (1.0 - cos(theta));
-		break;
-	case OBJ_SPHERE:
-		VCOPY(src->sloc, so->oargs.farg);
-		src->ss = so->oargs.farg[3];
-		src->ss2 = PI * src->ss * src->ss;
-		break;
-	case OBJ_FACE:
-						/* get the face */
-		f = getface(so);
-						/* find the center */
-		for (j = 0; j < 3; j++) {
-			src->sloc[j] = 0.0;
-			for (i = 0; i < f->nv; i++)
-				src->sloc[j] += VERTEX(f,i)[j];
-			src->sloc[j] /= f->nv;
-		}
-		if (!inface(src->sloc, f))
-			objerror(so, USER, "cannot hit center");
-		src->ss = sqrt(f->area / PI);
-		src->ss2 = f->area;
-		break;
-	case OBJ_RING:
-						/* get the ring */
-		co = getcone(so, 0);
-		VCOPY(src->sloc, CO_P0(co));
-		if (CO_R0(co) > 0.0)
-			objerror(so, USER, "cannot hit center");
-		src->ss = CO_R1(co);
-		src->ss2 = PI * src->ss * src->ss;
-		break;
-	default:
-		objerror(so, USER, "illegal material");
+	if (nsources <= 0) {
+		error(WARNING, "no light sources found");
+		return;
 	}
+	markvirtuals();			/* find and add virtual sources */
+				/* allocate our contribution arrays */
+	maxcntr = nsources + MAXSPART*2;	/* start with this many */
+	srccnt = (CONTRIB *)malloc(maxcntr*sizeof(CONTRIB));
+	cntord = (CNTPTR *)malloc(maxcntr*sizeof(CNTPTR));
+	if (srccnt == NULL || cntord == NULL)
+		goto memerr;
+	return;
+memerr:
+	error(SYSTEM, "out of memory in marksources");
 }
 
 
-SPOT *
-makespot(m)			/* make a spotlight */
-register OBJREC  *m;
-{
-	extern double  cos();
-	register SPOT  *ns;
-
-	if ((ns = (SPOT *)malloc(sizeof(SPOT))) == NULL)
-		error(SYSTEM, "out of memory in makespot");
-	ns->siz = 2.0*PI * (1.0 - cos(PI/180.0/2.0 * m->oargs.farg[3]));
-	VCOPY(ns->aim, m->oargs.farg+4);
-	if ((ns->flen = normalize(ns->aim)) == 0.0)
-		objerror(m, USER, "zero focus vector");
-	return(ns);
-}
-
-
-double
-srcray(sr, r, sn)		/* send a ray to a source, return domega */
+srcray(sr, r, si)		/* send a ray to a source, return domega */
 register RAY  *sr;		/* returned source ray */
 RAY  *r;			/* ray which hit object */
-register int  sn;		/* source number */
+SRCINDEX  *si;			/* source sample index */
 {
-	register double  *norm = NULL;	/* plane normal */
-	double  ddot;			/* (distance times) cosine */
-	FVECT  vd;
-	double  d;
-	register int  i;
+    double  d;				/* distance to source */
+    FVECT  vd;
+    register SRCREC  *srcp;
+    register int  i;
 
-	if (source[sn].sflags & SSKIP)
-		return(0.0);			/* skip this source */
+    rayorigin(sr, r, SHADOW, 1.0);		/* ignore limits */
 
-	rayorigin(sr, r, SHADOW, 1.0);		/* ignore limits */
-
-	sr->rsrc = sn;				/* remember source */
-						/* get source direction */
-	if (source[sn].sflags & SDISTANT)
-						/* constant direction */
-		VCOPY(sr->rdir, source[sn].sloc);
-	else {					/* compute direction */
-		for (i = 0; i < 3; i++)
-			sr->rdir[i] = source[sn].sloc[i] - sr->rorg[i];
-
-		if (source[sn].so->otype == OBJ_FACE)
- 			norm = getface(source[sn].so)->norm;
-		else if (source[sn].so->otype == OBJ_RING)
-			norm = getcone(source[sn].so,0)->ad;
-
-		if (norm != NULL && (ddot = -DOT(sr->rdir, norm)) <= FTINY)
-			return(0.0);		/* behind surface! */
-	}
-	if (dstrsrc > FTINY) {
-					/* distribute source direction */
-		for (i = 0; i < 3; i++)
-			vd[i] = dstrsrc * source[sn].ss * (1.0 - 2.0*frandom());
-
-		if (norm != NULL) {		/* project offset */
-			d = DOT(vd, norm);
+    while ((d = nextssamp(sr->rorg, sr->rdir, si)) != 0.0) {
+	sr->rsrc = si->sn;			/* remember source */
+	srcp = source + si->sn;
+	if (srcp->sflags & SDISTANT) {
+		if (srcp->sflags & SSPOT) {	/* check location */
 			for (i = 0; i < 3; i++)
-				vd[i] -= d * norm[i];
+			    vd[i] = srcp->sl.s->aim[i] - sr->rorg[i];
+			d = DOT(sr->rdir,vd);
+			if (d <= FTINY)
+				continue;
+			d = DOT(vd,vd) - d*d;
+			if (PI*d > srcp->sl.s->siz)
+				continue;
 		}
-		for (i = 0; i < 3; i++)		/* offset source direction */
-			sr->rdir[i] += vd[i];
-
-	} else if (source[sn].sflags & SDISTANT)
-						/* already normalized */
-		return(source[sn].ss2);
-
-	if ((d = normalize(sr->rdir)) == 0.0)
-						/* at source! */
-		return(0.0);
-	
-	if (source[sn].sflags & SDISTANT)
-						/* domega constant */
-		return(source[sn].ss2);
-
-	else {
+		return(1);		/* sample OK */
+	}
+				/* local source */
 						/* check proximity */
-		if (source[sn].sflags & SPROX &&
-				d > source[sn].sl.prox)
-			return(0.0);
-
-		if (norm != NULL)
-			ddot /= d;
-		else
-			ddot = 1.0;
+	if (srcp->sflags & SPROX && d > srcp->sl.prox)
+		continue;
 						/* check angle */
-		if (source[sn].sflags & SSPOT) {
-			if (source[sn].sl.s->siz < 2.0*PI *
-				(1.0 + DOT(source[sn].sl.s->aim,sr->rdir)))
-				return(0.0);
-			d += source[sn].sl.s->flen;
-		}
-						/* return domega */
-		return(ddot*source[sn].ss2/(d*d));
+	if (srcp->sflags & SSPOT) {
+		if (srcp->sl.s->siz < 2.0*PI *
+				(1.0 + DOT(srcp->sl.s->aim,sr->rdir)))
+			continue;
+					/* adjust solid angle */
+		si->dom *= d*d;
+		d += srcp->sl.s->flen;
+		si->dom /= d*d;
 	}
+	return(1);			/* sample OK */
+    }
+    return(0);			/* no more samples */
 }
 
 
-sourcehit(r)			/* check to see if ray hit distant source */
-register RAY  *r;
+srcvalue(r)			/* punch ray to source and compute value */
+RAY  *r;
 {
-	int  first, last;
-	register int  i;
+	register SRCREC  *sp;
 
-	if (r->rsrc >= 0) {		/* check only one if aimed */
-		first = last = r->rsrc;
-	} else {			/* otherwise check all */
-		first = 0; last = nsources-1;
+	sp = &source[r->rsrc];
+	if (sp->sflags & SVIRTUAL) {	/* virtual source */
+					/* check intersection */
+		if (!(*ofun[sp->so->otype].funp)(sp->so, r))
+			return;
+		raycont(r);		/* compute contribution */
+		return;
 	}
-	for (i = first; i <= last; i++)
-		if (source[i].sflags & 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) {
-		for (i = 0; i < 3; i++)
-			r->ron[i] = -r->rdir[i];
-		r->rod = 1.0;
-		r->rofs = 1.0; setident4(r->rofx);
-		r->robs = 1.0; setident4(r->robx);
-		return(1);
+					/* compute intersection */
+	if (sp->sflags & SDISTANT ? sourcehit(r) :
+			(*ofun[sp->so->otype].funp)(sp->so, r)) {
+		if (sp->sa.success >= 0)
+			sp->sa.success++;
+		raycont(r);		/* compute contribution */
+		return;
 	}
-	return(0);
+	if (sp->sa.success < 0)
+		return;			/* bitched already */
+	sp->sa.success -= AIMREQT;
+	if (sp->sa.success >= 0)
+		return;			/* leniency */
+	sprintf(errmsg, "aiming failure for light source \"%s\"",
+			sp->so->oname);
+	error(WARNING, errmsg);		/* issue warning */
 }
 
 
 static int
 cntcmp(sc1, sc2)			/* contribution compare (descending) */
-register CONTRIB  *sc1, *sc2;
+register CNTPTR  *sc1, *sc2;
 {
 	if (sc1->brt > sc2->brt)
 		return(-1);
@@ -301,134 +208,113 @@ RAY  *r;			/* ray that hit surface */
 int  (*f)();			/* direct component coefficient function */
 char  *p;			/* data for f */
 {
+	extern int  (*trace)();
+	extern double  pow();
 	register int  sn;
-	register CONTRIB  *srccnt;
-	double  dtmp, hwt, test2, hit2;
+	SRCINDEX  si;
+	int  nshadcheck, ncnts;
+	int  nhits;
+	double  prob, ourthresh, hwt;
 	RAY  sr;
-
-	if ((srccnt = (CONTRIB *)malloc(nsources*sizeof(CONTRIB))) == NULL)
-		error(SYSTEM, "out of memory in direct");
+			/* NOTE: srccnt and cntord global so no recursion */
+	if (nsources <= 0)
+		return;		/* no sources?! */
 						/* potential contributions */
-	for (sn = 0; sn < nsources; sn++) {
-		srccnt[sn].sno = sn;
-		setcolor(srccnt[sn].val, 0.0, 0.0, 0.0);
-		srccnt[sn].brt = 0.0;
-						/* get source ray */
-		if ((srccnt[sn].dom = srcray(&sr, r, sn)) == 0.0)
-			continue;
-		VCOPY(srccnt[sn].dir, sr.rdir);
+	initsrcindex(&si);
+	for (sn = 0; srcray(&sr, r, &si); sn++) {
+		if (sn >= maxcntr) {
+			maxcntr = sn + MAXSPART;
+			srccnt = (CONTRIB *)realloc((char *)srccnt,
+					maxcntr*sizeof(CONTRIB));
+			cntord = (CNTPTR *)realloc((char *)cntord,
+					maxcntr*sizeof(CNTPTR));
+			if (srccnt == NULL || cntord == NULL)
+				error(SYSTEM, "out of memory in direct");
+		}
+		cntord[sn].sndx = sn;
+		srccnt[sn].sno = sr.rsrc;
 						/* compute coefficient */
-		(*f)(srccnt[sn].val, p, srccnt[sn].dir, srccnt[sn].dom);
-		srccnt[sn].brt = bright(srccnt[sn].val);
-		if (srccnt[sn].brt <= FTINY)
+		(*f)(srccnt[sn].coef, p, sr.rdir, si.dom);
+		cntord[sn].brt = bright(srccnt[sn].coef);
+		if (cntord[sn].brt <= 0.0)
 			continue;
-						/* compute intersection */
-		if (!( source[sn].sflags & SDISTANT ?
-				sourcehit(&sr) :
-				(*ofun[source[sn].so->otype].funp)
-				(source[sn].so, &sr) ))
-			continue;
-						/* compute contribution */
-		rayshade(&sr, sr.ro->omod);
-		multcolor(srccnt[sn].val, sr.rcol);
-		srccnt[sn].brt = bright(srccnt[sn].val);
+		VCOPY(srccnt[sn].dir, sr.rdir);
+						/* compute potential */
+		sr.revf = srcvalue;
+		rayvalue(&sr);
+		copycolor(srccnt[sn].val, sr.rcol);
+		multcolor(srccnt[sn].val, srccnt[sn].coef);
+		cntord[sn].brt = bright(srccnt[sn].val);
 	}
 						/* sort contributions */
-	qsort(srccnt, nsources, sizeof(CONTRIB), cntcmp);
-	hit2 = test2 = 0.0;
+	qsort(cntord, sn, sizeof(CNTPTR), cntcmp);
+	{					/* find last */
+		register int  l, m;
+
+		ncnts = l = sn;
+		sn = 0;
+		while ((m = (sn + ncnts) >> 1) != l) {
+			if (cntord[m].brt > 0.0)
+				sn = m;
+			else
+				ncnts = m;
+			l = m;
+		}
+	}
+                                                /* accumulate tail */
+        for (sn = ncnts-1; sn > 0; sn--)
+                cntord[sn-1].brt += cntord[sn].brt;
+						/* compute number to check */
+	nshadcheck = pow((double)ncnts, shadcert) + .5;
+						/* modify threshold */
+	ourthresh = shadthresh / r->rweight;
 						/* test for shadows */
-	for (sn = 0; sn < nsources; sn++) {
+	nhits = 0;
+	for (sn = 0; sn < ncnts; sn++) {
 						/* check threshold */
-		if (srccnt[sn].brt <= shadthresh*bright(r->rcol)/r->rweight)
+		if ((sn+nshadcheck>=ncnts ? cntord[sn].brt :
+				cntord[sn].brt-cntord[sn+nshadcheck].brt)
+				< ourthresh*bright(r->rcol))
 			break;
-						/* get statistics */
-		hwt = (double)source[srccnt[sn].sno].nhits /
-				(double)source[srccnt[sn].sno].ntests;
-		test2 += hwt;
-		source[srccnt[sn].sno].ntests++;
 						/* test for hit */
 		rayorigin(&sr, r, SHADOW, 1.0);
-		VCOPY(sr.rdir, srccnt[sn].dir);
+		VCOPY(sr.rdir, srccnt[cntord[sn].sndx].dir);
+		sr.rsrc = srccnt[cntord[sn].sndx].sno;
+		source[sr.rsrc].ntests++;	/* keep statistics */
 		if (localhit(&sr, &thescene) &&
-				sr.ro != source[srccnt[sn].sno].so) {
-						/* check for transmission */
-			if (sr.clipset != NULL && inset(sr.clipset,sr.ro->omod))
-				raytrans(&sr);		/* object is clipped */
-			else
-				rayshade(&sr, sr.ro->omod);
+				( sr.ro != source[sr.rsrc].so ||
+				source[sr.rsrc].sflags & SFOLLOW )) {
+						/* follow entire path */
+			raycont(&sr);
+			if (trace != NULL)
+				(*trace)(&sr);	/* trace execution */
 			if (bright(sr.rcol) <= FTINY)
 				continue;	/* missed! */
-			(*f)(srccnt[sn].val, p, srccnt[sn].dir, srccnt[sn].dom);
-			multcolor(srccnt[sn].val, sr.rcol);
+			copycolor(srccnt[cntord[sn].sndx].val, sr.rcol);
+			multcolor(srccnt[cntord[sn].sndx].val,
+					srccnt[cntord[sn].sndx].coef);
 		}
 						/* add contribution if hit */
-		addcolor(r->rcol, srccnt[sn].val);
-		hit2 += hwt;
-		source[srccnt[sn].sno].nhits++;
+		addcolor(r->rcol, srccnt[cntord[sn].sndx].val);
+		nhits++;
+		source[sr.rsrc].nhits++;
 	}
-	if (test2 > FTINY)		/* weighted hit rate */
-		hwt = hit2 / test2;
+					/* surface hit rate */
+	if (sn > 0)
+		hwt = (double)nhits / (double)sn;
 	else
-		hwt = 0.0;
+		hwt = 0.5;
 #ifdef DEBUG
-	fprintf(stderr, "%d tested, %f hit rate\n", sn, hwt);
+	sprintf(errmsg, "%d tested, %d untested, %f hit rate\n",
+			sn, ncnts-sn, hwt);
+	eputs(errmsg);
 #endif
 					/* add in untested sources */
-	for ( ; sn < nsources; sn++) {
-		if (srccnt[sn].brt <= 0.0)
-			break;
-		dtmp = hwt * (double)source[srccnt[sn].sno].nhits /
-				(double)source[srccnt[sn].sno].ntests;
-		scalecolor(srccnt[sn].val, dtmp);
-		addcolor(r->rcol, srccnt[sn].val);
+	for ( ; sn < ncnts; sn++) {
+		sr.rsrc = srccnt[cntord[sn].sndx].sno;
+		prob = hwt * (double)source[sr.rsrc].nhits /
+				(double)source[sr.rsrc].ntests;
+		scalecolor(srccnt[cntord[sn].sndx].val, prob);
+		addcolor(r->rcol, srccnt[cntord[sn].sndx].val);
 	}
-		
-	free(srccnt);
 }
-
-
-#define  wrongsource(m, r)	(m->otype!=MAT_ILLUM && \
-				r->rsrc>=0 && \
-				source[r->rsrc].so!=r->ro)
-
-#define  badambient(m, r)	((r->crtype&(AMBIENT|SHADOW))==AMBIENT && \
-				!(r->rtype&REFLECTED) && 	/* hack! */\
-				!(m->otype==MAT_GLOW&&r->rot>m->oargs.farg[3]))
-
-#define  passillum(m, r)	(m->otype==MAT_ILLUM && \
-				!(r->rsrc>=0&&source[r->rsrc].so==r->ro))
-
-
-m_light(m, r)			/* ray hit a light source */
-register OBJREC  *m;
-register RAY  *r;
-{
-						/* check for behind */
-	if (r->rod < 0.0)
-		return;
-						/* check for over-counting */
-	if (wrongsource(m, r) || badambient(m, r))
-		return;
-						/* check for passed illum */
-	if (passillum(m, r)) {
-
-		if (m->oargs.nsargs < 1 || !strcmp(m->oargs.sarg[0], VOIDID))
-			raytrans(r);
-		else
-			rayshade(r, modifier(m->oargs.sarg[0]));
-
-						/* otherwise treat as source */
-	} else {
-						/* get distribution pattern */
-		raytexture(r, m->omod);
-						/* get source color */
-		setcolor(r->rcol, m->oargs.farg[0],
-				  m->oargs.farg[1],
-				  m->oargs.farg[2]);
-						/* modify value */
-		multcolor(r->rcol, r->pcol);
-	}
-}
-
-
-o_source() {}		/* intersection with a source is done elsewhere */