--- ray/src/rt/srcsupp.c	2003/12/31 02:03:08	2.13
+++ ray/src/rt/srcsupp.c	2010/10/25 22:57:45	2.18
@@ -1,5 +1,5 @@
 #ifndef lint
-static const char	RCSid[] = "$Id: srcsupp.c,v 2.13 2003/12/31 02:03:08 greg Exp $";
+static const char	RCSid[] = "$Id: srcsupp.c,v 2.18 2010/10/25 22:57:45 greg Exp $";
 #endif
 /*
  *  Support routines for source objects and materials
@@ -59,8 +59,8 @@ newsource()			/* allocate new source in our array */
 	if (source == NULL)
 		return(-1);
 	source[nsources].sflags = 0;
-	source[nsources].nhits = 0;
-	source[nsources].ntests = 1;	/* initial hit probability = 0 */
+	source[nsources].nhits = 1;
+	source[nsources].ntests = 2;	/* initial hit probability = 50% */
 #if SHADCACHE
 	source[nsources].obscache = NULL;
 #endif
@@ -101,6 +101,8 @@ OBJREC  *so;
 	src->so = so;
 						/* get the face */
 	f = getface(so);
+	if (f->area == 0.0)
+		objerror(so, USER, "zero source area");
 						/* find the center */
 	for (j = 0; j < 3; j++) {
 		src->sloc[j] = 0.0;
@@ -109,7 +111,7 @@ OBJREC  *so;
 		src->sloc[j] /= (double)f->nv;
 	}
 	if (!inface(src->sloc, f))
-		objerror(so, USER, "cannot hit center");
+		objerror(so, USER, "cannot hit source center");
 	src->sflags |= SFLAT;
 	VCOPY(src->snorm, f->norm);
 	src->ss2 = f->area;
@@ -143,7 +145,7 @@ register OBJREC  *so;
 	src->so = so;
 	if (so->oargs.nfargs != 4)
 		objerror(so, USER, "bad arguments");
-	src->sflags |= SDISTANT;
+	src->sflags |= (SDISTANT|SCIR);
 	VCOPY(src->sloc, so->oargs.farg);
 	if (normalize(src->sloc) == 0.0)
 		objerror(so, USER, "zero direction");
@@ -171,14 +173,15 @@ register OBJREC  *so;
 	if (so->oargs.nfargs != 4)
 		objerror(so, USER, "bad # arguments");
 	if (so->oargs.farg[3] <= FTINY)
-		objerror(so, USER, "illegal radius");
+		objerror(so, USER, "illegal source radius");
+	src->sflags |= SCIR;
 	VCOPY(src->sloc, so->oargs.farg);
 	src->srad = so->oargs.farg[3];
 	src->ss2 = PI * src->srad * src->srad;
 	for (i = 0; i < 3; i++)
 		src->ss[SU][i] = src->ss[SV][i] = src->ss[SW][i] = 0.0;
 	for (i = 0; i < 3; i++)
-		src->ss[i][i] = .7236 * so->oargs.farg[3];
+		src->ss[i][i] = 0.7236 * so->oargs.farg[3];
 }
 
 
@@ -193,10 +196,12 @@ OBJREC  *so;
 	src->so = so;
 						/* get the ring */
 	co = getcone(so, 0);
+	if (CO_R1(co) <= FTINY)
+		objerror(so, USER, "illegal source radius");
 	VCOPY(src->sloc, CO_P0(co));
 	if (CO_R0(co) > 0.0)
-		objerror(so, USER, "cannot hit center");
-	src->sflags |= SFLAT;
+		objerror(so, USER, "cannot hit source center");
+	src->sflags |= (SFLAT|SCIR);
 	VCOPY(src->snorm, co->ad);
 	src->srad = CO_R1(co);
 	src->ss2 = PI * src->srad * src->srad;
@@ -216,6 +221,8 @@ OBJREC  *so;
 	src->so = so;
 						/* get the cylinder */
 	co = getcone(so, 0);
+	if (CO_R0(co) <= FTINY)
+		objerror(so, USER, "illegal source radius");
 	if (CO_R0(co) > .2*co->al)		/* heuristic constraint */
 		objerror(so, WARNING, "source aspect too small");
 	src->sflags |= SCYL;
@@ -249,6 +256,8 @@ register OBJREC  *m;
 		return(ns);
 	if ((ns = (SPOT *)malloc(sizeof(SPOT))) == NULL)
 		return(NULL);
+	if (m->oargs.farg[3] <= FTINY)
+		objerror(m, USER, "zero angle");
 	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)
@@ -390,14 +399,11 @@ FVECT  dir;
 {
 	FVECT  cent, c1, c2;
 	double  rad2, d;
-	register int  i;
 					/* move centers to common plane */
 	d = DOT(sp1->aim, dir);
-	for (i = 0; i < 3; i++)
-		c1[i] = sp1->aim[i] - d*dir[i];
+	VSUM(c1, sp1->aim, dir, -d);
 	d = DOT(sp2->aim, dir);
-	for (i = 0; i < 3; i++)
-		c2[i] = sp2->aim[i] - d*dir[i];
+	VSUM(c2, sp2->aim, dir, -d);
 					/* compute overlap */
 	rad2 = intercircle(cent, c1, c2, sp1->siz/PI, sp2->siz/PI);
 	if (rad2 <= FTINY)
@@ -433,7 +439,6 @@ FVECT  pos;
 {
 	FVECT  onorm;
 	double  offs, d, dist;
-	register int  i;
 
 	offs = getplaneq(onorm, op);
 	d = -DOT(onorm, sp->aim);
@@ -442,8 +447,7 @@ FVECT  pos;
 	dist = (DOT(pos, onorm) - offs)/d;
 	if (dist < 0.)
 		return(0.);
-	for (i = 0; i < 3; i++)
-		oc[i] = pos[i] + dist*sp->aim[i];
+	VSUM(oc, pos, sp->aim, dist);
 	return(sp->siz*dist*dist/PI/(d*d));
 }
 
@@ -457,15 +461,13 @@ FVECT  dir;
 {
 	FVECT  onorm;
 	double  offs, d, dist;
-	register int  i;
 
 	offs = getplaneq(onorm, op);
 	d = -DOT(onorm, dir);
 	if (d >= -FTINY && d <= FTINY)
 		return(0.);
 	dist = (DOT(sp->aim, onorm) - offs)/d;
-	for (i = 0; i < 3; i++)
-		oc[i] = sp->aim[i] + dist*dir[i];
+	VSUM(oc, sp->aim, dir, dist);
 	return(sp->siz/PI/(d*d));
 }
 
@@ -478,10 +480,8 @@ double  r1s, r2s;		/* radii squared */
 {
 	double  a2, d2, l;
 	FVECT  disp;
-	register int  i;
 
-	for (i = 0; i < 3; i++)
-		disp[i] = c2[i] - c1[i];
+	VSUB(disp, c2, c1);
 	d2 = DOT(disp,disp);
 					/* circle within overlap? */
 	if (r1s < r2s) {
@@ -501,7 +501,6 @@ double  r1s, r2s;		/* radii squared */
 		return(0.);
 					/* overlap, compute center */
 	l = sqrt((r1s - a2)/d2);
-	for (i = 0; i < 3; i++)
-		cc[i] = c1[i] + l*disp[i];
+	VSUM(cc, c1, disp, l);
 	return(a2);
 }