--- ray/src/rt/dielectric.c	1991/08/05 13:52:20	1.6
+++ ray/src/rt/dielectric.c	1993/11/18 09:43:00	2.6
@@ -16,6 +16,8 @@ static char SCCSid[] = "$SunId$ LBL";
 
 #ifdef  DISPERSE
 #include  "source.h"
+static  disperse();
+static int  lambda();
 #endif
 
 /*
@@ -53,7 +55,6 @@ m_dielectric(m, r)	/* color a ray which hit something 
 OBJREC  *m;
 register RAY  *r;
 {
-	double  sqrt(), pow();
 	double  cos1, cos2, nratio;
 	COLOR  mcolor;
 	double  mabsorp;
@@ -66,8 +67,6 @@ register RAY  *r;
 	if (m->oargs.nfargs != (m->otype==MAT_DIELECTRIC ? 5 : 8))
 		objerror(m, USER, "bad arguments");
 
-	r->rt = r->rot;				/* just use ray length */
-
 	raytexture(r, m->omod);			/* get modifiers */
 
 	cos1 = raynormal(dnorm, r);		/* cosine of theta1 */
@@ -129,7 +128,7 @@ register RAY  *r;
 			if (m->otype != MAT_DIELECTRIC
 					|| r->rod > 0.0
 					|| r->crtype & SHADOW
-					|| directinvis
+					|| !directvis
 					|| m->oargs.farg[4] == 0.0
 					|| !disperse(m, r, p.rdir, trans))
 #endif
@@ -138,6 +137,8 @@ register RAY  *r;
 				multcolor(mcolor, r->pcol);	/* modify */
 				scalecolor(p.rcol, trans);
 				addcolor(r->rcol, p.rcol);
+				if (nratio >= 1.0-FTINY && nratio <= 1.0+FTINY)
+					r->rt = r->rot + p.rt;
 			}
 		}
 	}
@@ -168,13 +169,12 @@ RAY  *r;
 FVECT  vt;
 double  tr;
 {
-	double  sqrt();
 	RAY  sray, *entray;
 	FVECT  v1, v2, n1, n2;
 	FVECT  dv, v2Xdv;
 	double  v2Xdvv2Xdv;
-	int  sn, success = 0;
-	double  omega;
+	int  success = 0;
+	SRCINDEX  si;
 	FVECT  vtmp1, vtmp2;
 	double  dtmp1, dtmp2;
 	int  l1, l2;
@@ -236,12 +236,11 @@ double  tr;
 	v2Xdvv2Xdv = DOT(v2Xdv, v2Xdv);
 
 					/* check sources */
-	for (sn = 0; sn < nsources; sn++) {
+	initsrcindex(&si);
+	while (srcray(&sray, r, &si)) {
 
-		if ((omega = srcray(&sray, r, sn)) == 0.0 ||
-				DOT(sray.rdir, v2) < MINCOS)
+		if (DOT(sray.rdir, v2) < MINCOS)
 			continue;			/* bad source */
-		
 						/* adjust source ray */
 
 		dtmp1 = DOT(v2Xdv, sray.rdir) / v2Xdvv2Xdv;
@@ -266,7 +265,7 @@ double  tr;
 		 */
 		 
 		fcross(vtmp1, v2Xdv, sray.rdir);
-		dtmp1 = sqrt(omega  / v2Xdvv2Xdv / PI);
+		dtmp1 = sqrt(si.dom  / v2Xdvv2Xdv / PI);
 
 							/* compute first ray */
 		for (i = 0; i < 3; i++)