--- ray/src/rt/source.c	1991/07/30 18:23:41	1.40
+++ ray/src/rt/source.c	1991/08/22 11:56:55	1.44
@@ -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";
@@ -140,13 +140,10 @@ register int  sn;		/* source number */
 	}
 	if (dstrsrc > FTINY) {
 					/* distribute source direction */
-		dimlist[ndims++] = sn;
-		for (i = 0; i < 3; i++) {
-			dimlist[ndims] = i + 8831;
-			vd[i] = dstrsrc * source[sn].ss *
-		(1.0 - 2.0*urand(urind(ilhash(dimlist,ndims+1),samplendx)));
-		}
-		ndims--;
+		dimlist[ndims] = sn + 8831;
+		multisamp(vd, 3, urand(ilhash(dimlist,ndims+1)+samplendx));
+		for (i = 0; i < 3; i++)
+			vd[i] = dstrsrc * source[sn].ss * (1. - 2.*vd[i]);
 		if (source[sn].sflags & SFLAT) {	/* project offset */
 			d = DOT(vd, source[sn].snorm);
 			for (i = 0; i < 3; i++)
@@ -164,8 +161,10 @@ register int  sn;		/* source number */
 	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];
+				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);
@@ -245,6 +244,7 @@ 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 +314,8 @@ 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);