--- ray/src/rt/srcobstr.c	2003/12/31 19:38:27	2.1
+++ ray/src/rt/srcobstr.c	2004/06/22 13:40:54	2.5
@@ -1,5 +1,5 @@
 #ifndef lint
-static const char RCSid[] = "$Id: srcobstr.c,v 2.1 2003/12/31 19:38:27 greg Exp $";
+static const char RCSid[] = "$Id: srcobstr.c,v 2.5 2004/06/22 13:40:54 greg Exp $";
 #endif
 /*
  * Source occlusion caching routines
@@ -136,7 +136,7 @@ initobscache(int sn)
 				else
 					VSUM(rdir, srcp->obscache->p.f.v,
 						srcp->obscache->p.f.u, d);
-				d = 2./SHADCACHE*(j+.5);
+				d = 1. - 2./SHADCACHE*(j+.5);
 				VSUM(rdir, rdir, srcp->snorm, d);
 				normalize(rdir);
 				castshadow(sn, rorg, rdir);
@@ -197,7 +197,7 @@ srcobstructp(register RAY *r)
 		ondx += (int)(2*SHADCACHE*srcp->obscache->p.d.e2 *
 				(r->rorg[ax2] + t*srcp->sloc[ax2] -
 					srcp->obscache->p.d.o[ax2]));
-		if (ondx < 0 | ondx >= 4*SHADCACHE*SHADCACHE)
+		if ((ondx < 0) | (ondx >= 4*SHADCACHE*SHADCACHE))
 			return(&noobs); /* could happen if ray is outside */
 	} else if (srcp->sflags & SFLAT) {
 		FVECT   sd;
@@ -219,7 +219,7 @@ srcobstructp(register RAY *r)
 			if (sd[0] < 0)
 				ondx += ((SHADCACHE+1)>>1)*SHADCACHE;
 			ondx += SHADCACHE*(int)(SHADCACHE*(.5-FTINY) *
-					sd[2]/sd0m);
+					(1. - sd[2]/sd0m));
 			ondx += (int)(SHADCACHE*(.5-FTINY) *
 					(1. + sd[1]/sd0m));
 		} else /* sd1m > sd0m */ {
@@ -228,10 +228,13 @@ srcobstructp(register RAY *r)
 			if (sd[1] < 0)
 				ondx += ((SHADCACHE+1)>>1)*SHADCACHE;
 			ondx += SHADCACHE*(int)(SHADCACHE*(.5-FTINY) *
-					sd[2]/sd1m);
+					(1. - sd[2]/sd1m));
 			ondx += (int)(SHADCACHE*(.5-FTINY) *
 					(1. + sd[0]/sd1m));
 		}
+		DCHECK(ondx < 0 | ondx >= SHADCACHE*SHADCACHE*3 +
+				(SHADCACHE&1)*SHADCACHE*4, CONSISTENCY,
+				"flat source cache index out of bounds");
 	} else /* spherical distribution */ {
 		int     ax, ax1, ax2;
 		RREAL   amax = 0;
@@ -249,6 +252,8 @@ srcobstructp(register RAY *r)
 					(1. + r->rdir[ax1]/amax));
 		ondx += (int)(SHADCACHE*(.5-FTINY) *
 				(1. + r->rdir[ax2]/amax));
+		DCHECK(ondx < 0 | ondx >= SHADCACHE*SHADCACHE*6, CONSISTENCY,
+				"radial source cache index out of bounds");
 	}
 					/* return cache pointer */
 	return(&srcp->obscache->obs[ondx]);
@@ -276,7 +281,7 @@ srcblocker(register RAY *r)
 	m = findmaterial(r->ro);
 	if (m == NULL)
 		return;			/* no material?! */
-	if (!(ofun[m->otype].flags & T_OPAQUE))
+	if (!isopaque(m->otype))
 		return;			/* material not a reliable blocker */
 	*srcobstructp(r) = r->robj;     /* else record obstructor */
 }
@@ -291,7 +296,7 @@ srcblocked(RAY *r)
 	if (obs == OVOID)
 		return(0);
 	op = objptr(obs);		/* check for intersection */
-	return ((*ofun[op->otype].funp)(op, r));
+	return((*ofun[op->otype].funp)(op, r));
 }