--- ray/src/rt/raytrace.c	1991/05/01 11:17:01	1.15
+++ ray/src/rt/raytrace.c	1993/01/25 15:16:59	2.2
@@ -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";
@@ -23,12 +23,13 @@ extern int  maxdepth;			/* maximum recursion depth */
 extern double  minweight;		/* minimum ray weight */
 extern int  do_irrad;			/* compute irradiance? */
 
-long  nrays = 0L;			/* number of rays traced */
+long  raynum = 0L;			/* next unique ray number */
+long  nrays = 0L;			/* number of calls to localhit */
 
-static double  Lambfa[5] = {PI, PI, PI, 0.0, 0.0};
+static FLOAT  Lambfa[5] = {PI, PI, PI, 0.0, 0.0};
 OBJREC  Lamb = {
 	OVOID, MAT_PLASTIC, "Lambertian",
-	{0, 5, NULL, Lambfa}, NULL, -1,
+	{0, 5, NULL, Lambfa}, NULL,
 };					/* a Lambertian surface */
 
 #define  MAXLOOP	128		/* modifier loop detection */
@@ -47,6 +48,7 @@ double  rw;
 		r->crtype = r->rtype = rt;
 		r->rsrc = -1;
 		r->clipset = NULL;
+		r->revf = raytrace;
 	} else {				/* spawned ray */
 		r->rlvl = ro->rlvl;
 		if (rt & RAYREFL) {
@@ -57,11 +59,21 @@ double  rw;
 			r->rsrc = ro->rsrc;
 			r->clipset = ro->newcset;
 		}
+		r->revf = ro->revf;
 		r->rweight = ro->rweight * rw;
 		r->crtype = ro->crtype | (r->rtype = rt);
 		VCOPY(r->rorg, ro->rop);
 	}
-	r->rno = nrays;
+	rayclear(r);
+	return(r->rlvl <= maxdepth && r->rweight >= minweight ? 0 : -1);
+}
+
+
+rayclear(r)			/* clear a ray for (re)evaluation */
+register RAY  *r;
+{
+	r->rno = raynum++;
+	r->cxs[0] = 0;
 	r->newcset = r->clipset;
 	r->ro = NULL;
 	r->rot = FHUGE;
@@ -69,11 +81,10 @@ double  rw;
 	setcolor(r->pcol, 1.0, 1.0, 1.0);
 	setcolor(r->rcol, 0.0, 0.0, 0.0);
 	r->rt = 0.0;
-	return(r->rlvl <= maxdepth && r->rweight >= minweight ? 0 : -1);
 }
 
 
-rayvalue(r)			/* compute a ray's value */
+raytrace(r)			/* trace a ray and compute its value */
 RAY  *r;
 {
 	extern int  (*trace)();
@@ -118,17 +129,10 @@ int  mod;
 {
 	static int  depth = 0;
 	register OBJREC  *m;
-					/* check for irradiance calc. */
-	if (do_irrad && !(r->crtype & ~(PRIMARY|TRANS))) {
-		if (irr_ignore(objptr(mod)->otype))
-			raytrans(r);
-		else
-			(*ofun[Lamb.otype].funp)(&Lamb, r);
-		return;
-	}
 					/* check for infinite loop */
 	if (depth++ >= MAXLOOP)
 		objerror(r->ro, USER, "possible modifier loop");
+	r->rt = r->rot;			/* set effective ray length */
 	for ( ; mod != OVOID; mod = m->omod) {
 		m = objptr(mod);
 		/****** unnecessary test since modifier() is always called
@@ -137,8 +141,17 @@ int  mod;
 			error(USER, errmsg);
 		}
 		******/
+					/* hack for irradiance calculation */
+		if (do_irrad && !(r->crtype & ~(PRIMARY|TRANS))) {
+			if (irr_ignore(m->otype)) {
+				depth--;
+				raytrans(r);
+				return;
+			}
+			if (!islight(m->otype))
+				m = &Lamb;
+		}
 		(*ofun[m->otype].funp)(m, r);	/* execute function */
-		m->lastrno = r->rno;
 		if (ismaterial(m->otype)) {	/* materials call raytexture */
 			depth--;
 			return;		/* we're done */
@@ -165,7 +178,6 @@ int  mod;
 			error(USER, errmsg);
 		}
 		(*ofun[m->otype].funp)(m, r);
-		m->lastrno = r->rno;
 	}
 	depth--;			/* end here */
 }
@@ -311,7 +323,6 @@ register CUBE  *scene;
 	register int  i;
 
 	nrays++;			/* increment trace counter */
-
 	sflags = 0;
 	for (i = 0; i < 3; i++) {
 		curpos[i] = r->rorg[i];
@@ -320,6 +331,8 @@ register CUBE  *scene;
 		else if (r->rdir[i] < -FTINY)
 			sflags |= 0x10 << i;
 	}
+	if (sflags == 0)
+		error(CONSISTENCY, "zero ray direction in localhit");
 	t = 0.0;
 	if (!incube(scene, curpos)) {
 					/* find distance to entry */
@@ -440,15 +453,40 @@ CUBE  *cu;
 	register int  i;
 
 	objset(oset, cu->cutree);
+	checkset(oset, r->cxs);			/* eliminate double-checking */
 	for (i = oset[0]; i > 0; i--) {
 		o = objptr(oset[i]);
-		if (o->lastrno == r->rno)		/* checked already? */
-			continue;
 		(*ofun[o->otype].funp)(o, r);
-		o->lastrno = r->rno;
 	}
 	if (r->ro == NULL)
 		return(0);			/* no scores yet */
 
 	return(incube(cu, r->rop));		/* hit OK if in current cube */
+}
+
+
+static
+checkset(os, cs)		/* modify checked set and set to check */
+register OBJECT  os[MAXSET+1];		/* os' = os - cs */
+register OBJECT  cs[MAXCSET+1];		/* cs' = cs + os */
+{
+	OBJECT  cset[MAXCSET+MAXSET+1];
+	register int  i, j, k;
+					/* copy os in place, cset <- cs */
+	cset[0] = 0;
+	k = 0;
+	for (i = j = 1; i <= os[0]; i++) {
+		while (j <= cs[0] && cs[j] < os[i])
+			cset[++cset[0]] = cs[j++];
+		if (j > cs[0] || os[i] != cs[j]) {	/* object to check */
+			os[++k] = os[i];
+			cset[++cset[0]] = os[i];
+		}
+	}
+	while (j <= cs[0])		/* get the rest of cs */
+		cset[++cset[0]] = cs[j++];
+	if (cset[0] > MAXCSET)		/* truncate if necessary */
+		cset[0] = MAXCSET;
+	setcopy(cs, cset);		/* copy new "checked" set back */
+	os[0] = k;			/* new "to check" set size */
 }