--- ray/src/rt/srcsupp.c	1991/06/24 16:00:30	1.5
+++ ray/src/rt/srcsupp.c	1991/06/25 16:42:03	1.8
@@ -105,7 +105,7 @@ register OBJREC  *so;
 	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->ss = theta >= PI/4.0 ? 1.0 : tan(theta);
 	src->ss2 = 2.0*PI * (1.0 - cos(theta));
 }
 
@@ -288,10 +288,56 @@ FVECT  nrm;		/* source surface normal */
 
 	d = DOT(sp->aim, nrm);
 	if (d > FTINY)			/* center in front? */
-		return(0);
+		return(1);
 					/* else check horizon */
 	d1 = 1. - sp->siz/(2.*PI);
-	return(1.-FTINY-d*d > d1*d1);
+	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));
 }