--- ray/src/rt/source.c	1991/07/11 16:39:03	1.39
+++ ray/src/rt/source.c	1991/08/12 08:20:49	1.42
@@ -1,4 +1,4 @@
-/* Copyright (c) 1990 Regents of the University of California */
+/* Copyright (c) 1991 Regents of the University of California */
 
 #ifndef lint
 static char SCCSid[] = "$SunId$ LBL";
@@ -128,14 +128,6 @@ register int  sn;		/* source number */
 	sr->rsrc = sn;				/* remember source */
 						/* get source direction */
 	if (source[sn].sflags & SDISTANT) {
-		if (source[sn].sflags & SSPOT) {	/* check location */
-			for (i = 0; i < 3; i++)
-				vd[i] = sr->rorg[i] - source[sn].sl.s->aim[i];
-			d = DOT(source[sn].sloc,vd);
-			d = DOT(vd,vd) - d*d;
-			if (PI*d > source[sn].sl.s->siz)
-				return(0.0);
-		}
 						/* constant direction */
 		VCOPY(sr->rdir, source[sn].sloc);
 	} else {				/* compute direction */
@@ -162,19 +154,29 @@ register int  sn;		/* source number */
 		}
 		for (i = 0; i < 3; i++)		/* offset source direction */
 			sr->rdir[i] += vd[i];
+						/* normalize */
+		d = normalize(sr->rdir);
 
-	} else if (source[sn].sflags & SDISTANT)
-						/* already normalized */
-		return(source[sn].ss2);
+	} else if (!(source[sn].sflags & SDISTANT))
+						/* normalize direction */
+		d = normalize(sr->rdir);
 
-	if ((d = normalize(sr->rdir)) == 0.0)
-						/* at source! */
+	if (source[sn].sflags & SDISTANT) {
+		if (source[sn].sflags & SSPOT) {	/* check location */
+			for (i = 0; i < 3; i++)
+				vd[i] = source[sn].sl.s->aim[i] - sr->rorg[i];
+			d = DOT(sr->rdir,vd);
+			if (d <= FTINY)
+				return(0.0);
+			d = DOT(vd,vd) - d*d;
+			if (PI*d > source[sn].sl.s->siz)
+				return(0.0);
+		}
+		return(source[sn].ss2);		/* domega constant */
+	}
+						/* check direction */
+	if (d == 0.0)
 		return(0.0);
-	
-	if (source[sn].sflags & SDISTANT)
-						/* domega constant */
-		return(source[sn].ss2);
-
 						/* check proximity */
 	if (source[sn].sflags & SPROX &&
 			d > source[sn].sl.prox)
@@ -245,6 +247,7 @@ 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;
 	int  nshadcheck, ncnts;
@@ -314,6 +317,8 @@ char  *p;			/* data for f */
 				source[cntord[sn].sno].sflags & SFOLLOW )) {
 						/* follow entire path */
 			raycont(&sr);
+			if (trace != NULL)
+				(*trace)(&sr);	/* trace execution */
 			if (bright(sr.rcol) <= FTINY)
 				continue;	/* missed! */
 			copycolor(srccnt[cntord[sn].sno].val, sr.rcol);