--- ray/src/rt/srcobstr.c	2004/01/01 19:31:46	2.2
+++ ray/src/rt/srcobstr.c	2004/09/08 06:07:52	2.7
@@ -1,5 +1,5 @@
 #ifndef lint
-static const char RCSid[] = "$Id: srcobstr.c,v 2.2 2004/01/01 19:31:46 greg Exp $";
+static const char RCSid[] = "$Id: srcobstr.c,v 2.7 2004/09/08 06:07:52 greg Exp $";
 #endif
 /*
  * Source occlusion caching routines
@@ -19,7 +19,7 @@ static const char RCSid[] = "$Id: srcobstr.c,v 2.2 200
 #if  SHADCACHE			/* preemptive shadow checking */
 
 
-static void				/* cast source ray to first blocker */
+static int				/* cast source ray to first blocker */
 castshadow(int sn, FVECT rorg, FVECT rdir)
 {
 	RAY     rt;
@@ -28,19 +28,25 @@ castshadow(int sn, FVECT rorg, FVECT rdir)
 	VCOPY(rt.rdir, rdir);
 	rt.rmax = 0;
 	rayorigin(&rt, NULL, PRIMARY, 1.0);
-	if (!localhit(&rt, &thescene))
-		return;
-					/* pretend we were aimed at source */
-	rt.crtype |= rt.rtype = SHADOW;
-	rt.rdir[0] = -rt.rdir[0];
-	rt.rdir[1] = -rt.rdir[1];
-	rt.rdir[2] = -rt.rdir[2];
-	rt.rod = -rt.rod;
-	VSUB(rt.rorg, rt.rop, rt.rdir);
-	rt.rot = 1.;
-	rt.rsrc = sn;
+					/* check for intersection */
+	while (localhit(&rt, &thescene)) {
+		RAY	rt1 = rt;	/* pretend we were aimed at source */
+		rt1.crtype |= rt1.rtype = SHADOW;
+		rt1.rdir[0] = -rt.rdir[0];
+		rt1.rdir[1] = -rt.rdir[1];
+		rt1.rdir[2] = -rt.rdir[2];
+		rt1.rod = -rt.rod;
+		VSUB(rt1.rorg, rt.rop, rt.rdir);
+		rt1.rot = 1.;
+		rt1.rsrc = sn;
 					/* record blocker */
-	srcblocker(&rt);
+		if (srcblocker(&rt1))
+			return(1);
+					/* move past failed blocker */
+		VSUM(rt.rorg, rt.rop, rt.rdir, FTINY);
+		rayclear(&rt);		/* & try again... */
+	}
+	return(0);			/* found no blockers */
 }
 
 
@@ -136,7 +142,7 @@ 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);
@@ -169,13 +175,19 @@ initobscache(int sn)
 static OBJECT *			/* return occluder cache entry */
 srcobstructp(register RAY *r)
 {
+	static unsigned long	lastrno = ~0;
 	static OBJECT   noobs;
+	static OBJECT	*lastobjp;
 	SRCREC		*srcp;
 	int		ondx;
 
+	noobs = OVOID;
+	if (r->rno == lastrno)
+		return lastobjp;	/* just recall last pointer */
 	DCHECK(r->rsrc < 0, CONSISTENCY,
 			"srcobstructp() called with unaimed ray");
-	noobs = OVOID;
+	lastrno = r->rno;
+	lastobjp = &noobs;
 	srcp = &source[r->rsrc];
 	if (srcp->sflags & (SSKIP|SPROX|SSPOT|SVIRTUAL))
 		return(&noobs);		/* don't cache these */
@@ -197,7 +209,7 @@ 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 +231,7 @@ 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 +240,13 @@ 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;
@@ -249,9 +264,11 @@ 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]);
+	return(lastobjp = &srcp->obscache->obs[ondx]);
 }
 
 
@@ -265,20 +282,21 @@ freeobscache(SRCREC *srcp)
 }
 
 	
-void				/* record a source blocker */
+int				/* record a source blocker */
 srcblocker(register RAY *r)
 {
 	OBJREC  *m;
 
 	if (r->robj == OVOID || objptr(r->robj) != r->ro ||
 			isvolume(r->ro->otype))
-		return;			/* don't record complex blockers */
+		return(0);		/* don't record complex blockers */
 	m = findmaterial(r->ro);
 	if (m == NULL)
-		return;			/* no material?! */
-	if (!(ofun[m->otype].flags & T_OPAQUE))
-		return;			/* material not a reliable blocker */
+		return(0);		/* no material?! */
+	if (!isopaque(m->otype))
+		return(0);		/* material not a reliable blocker */
 	*srcobstructp(r) = r->robj;     /* else record obstructor */
+	return(1);
 }