--- ray/src/rt/srcsupp.c	1991/06/21 16:44:01	1.4
+++ ray/src/rt/srcsupp.c	1991/06/25 13:11:55	1.6
@@ -168,24 +168,27 @@ FVECT  ocent;
 OBJREC  *op;
 {
 	double  maxrad2;
-	double  d2;
+	double  d;
 	register int  i, j;
 	register FACE  *f;
 	
 	f = getface(op);
+	if (f->area == 0.)
+		return(0.);
 	for (i = 0; i < 3; i++) {
 		ocent[i] = 0.;
 		for (j = 0; j < f->nv; j++)
 			ocent[i] += VERTEX(f,j)[i];
 		ocent[i] /= (double)f->nv;
 	}
-	if (f->area == 0.)
-		return(0.);
+	d = DOT(ocent,f->norm);
+	for (i = 0; i < 3; i++)
+		ocent[i] += (f->offset - d)*f->norm[i];
 	maxrad2 = 0.;
 	for (j = 0; j < f->nv; j++) {
-		d2 = dist2(VERTEX(f,j), ocent);
-		if (d2 > maxrad2)
-			maxrad2 = d2;
+		d = dist2(VERTEX(f,j), ocent);
+		if (d > maxrad2)
+			maxrad2 = d;
 	}
 	return(maxrad2);
 }
@@ -289,6 +292,52 @@ FVECT  nrm;		/* source surface normal */
 					/* else check horizon */
 	d1 = 1. - sp->siz/(2.*PI);
 	return(1.-FTINY-d*d > d1*d1);
+}
+
+
+double
+spotdisk(oc, op, sp, pos)	/* intersect spot with object op */
+FVECT  oc;
+OBJREC  *op;
+register SPOT  *sp;
+FVECT  pos;
+{
+	FVECT  onorm;
+	double  offs, d, dist;
+	register int  i;
+
+	offs = getplaneq(onorm, op);
+	d = -DOT(onorm, sp->aim);
+	if (d >= -FTINY && d <= FTINY)
+		return(0.);
+	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];
+	return(sp->siz*dist*dist/PI/(d*d));
+}
+
+
+double
+beamdisk(oc, op, sp, dir)	/* intersect beam with object op */
+FVECT  oc;
+OBJREC  *op;
+register SPOT  *sp;
+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];
+	return(sp->siz/PI/(d*d));
 }