--- ray/src/rt/raytrace.c	1991/05/29 11:09:23	1.18
+++ ray/src/rt/raytrace.c	1993/02/23 13:57:11	2.4
@@ -18,17 +18,20 @@ static char SCCSid[] = "$SunId$ LBL";
 
 #include  "otspecial.h"
 
+#define  MAXCSET	((MAXSET+1)*2-1)	/* maximum check set size */
+
 extern CUBE  thescene;			/* our scene */
 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 +50,7 @@ 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 +61,20 @@ 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->newcset = r->clipset;
 	r->ro = NULL;
 	r->rot = FHUGE;
@@ -69,11 +82,10 @@ 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)();
@@ -121,6 +133,7 @@ int  mod;
 					/* 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
@@ -140,7 +153,6 @@ int  mod;
 				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 */
@@ -167,7 +179,6 @@ int  mod;
 			error(USER, errmsg);
 		}
 		(*ofun[m->otype].funp)(m, r);
-		m->lastrno = r->rno;
 	}
 	depth--;			/* end here */
 }
@@ -307,13 +318,13 @@ localhit(r, scene)		/* check for hit in the octree */
 register RAY  *r;
 register CUBE  *scene;
 {
+	OBJECT  cxset[MAXCSET+1];	/* set of checked objects */
 	FVECT  curpos;			/* current cube position */
 	int  sflags;			/* sign flags */
 	double  t, dt;
 	register int  i;
 
 	nrays++;			/* increment trace counter */
-
 	sflags = 0;
 	for (i = 0; i < 3; i++) {
 		curpos[i] = r->rorg[i];
@@ -348,13 +359,15 @@ register CUBE  *scene;
 		if (!incube(scene, curpos))	/* non-intersecting ray */
 			return(0);
 	}
-	return(raymove(curpos, sflags, r, scene) == RAYHIT);
+	cxset[0] = 0;
+	return(raymove(curpos, cxset, sflags, r, scene) == RAYHIT);
 }
 
 
 static int
-raymove(pos, dirf, r, cu)		/* check for hit as we move */
-FVECT  pos;			/* modified */
+raymove(pos, cxs, dirf, r, cu)		/* check for hit as we move */
+FVECT  pos;			/* current position, modified herein */
+OBJECT  *cxs;			/* checked objects, modified by checkhit */
 int  dirf;			/* direction indicators to speed tests */
 register RAY  *r;
 register CUBE  *cu;
@@ -383,7 +396,7 @@ register CUBE  *cu;
 		}
 		for ( ; ; ) {
 			cukid.cutree = octkid(cu->cutree, br);
-			if ((ax = raymove(pos,dirf,r,&cukid)) == RAYHIT)
+			if ((ax = raymove(pos,cxs,dirf,r,&cukid)) == RAYHIT)
 				return(RAYHIT);
 			sgn = 1 << ax;
 			if (sgn & dirf)			/* positive axis? */
@@ -402,7 +415,7 @@ register CUBE  *cu;
 		}
 		/*NOTREACHED*/
 	}
-	if (isfull(cu->cutree) && checkhit(r, cu))
+	if (isfull(cu->cutree) && checkhit(r, cu, cxs))
 		return(RAYHIT);
 					/* advance to next cube */
 	if (dirf&0x11) {
@@ -435,24 +448,57 @@ register CUBE  *cu;
 
 
 static
-checkhit(r, cu)			/* check for hit in full cube */
+checkhit(r, cu, cxs)		/* check for hit in full cube */
 register RAY  *r;
 CUBE  *cu;
+OBJECT  *cxs;
 {
 	OBJECT  oset[MAXSET+1];
 	register OBJREC  *o;
 	register int  i;
 
 	objset(oset, cu->cutree);
+	checkset(oset, cxs);			/* eliminate double-checking */
 	for (i = oset[0]; i > 0; i--) {
 		o = objptr(oset[i]);
-		if (o->lastrno == r->rno)		/* checked already? */
-			continue;
+		if (o->omod == OVOID && issurface(o->otype))
+			continue;		/* ignore void surfaces */
 		(*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;			/* os' = os - cs */
+register OBJECT  *cs;			/* cs' = cs + os */
+{
+	OBJECT  cset[MAXCSET+MAXSET+1];
+	register int  i, j;
+	int  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];
+		}
+	}
+	if (!(os[0] = k))		/* new "to check" set size */
+		return;			/* special case */
+	while (j <= cs[0])		/* get the rest of cs */
+		cset[++cset[0]] = cs[j++];
+	if (cset[0] > MAXCSET)		/* truncate "checked" set if nec. */
+		cset[0] = MAXCSET;
+	/* setcopy(cs, cset); */	/* copy cset back to cs */
+	os = cset;
+	for (i = os[0]; i-- >= 0; )
+		*cs++ = *os++;
 }