--- ray/src/rt/raytrace.c	1993/01/25 15:16:59	2.2
+++ ray/src/rt/raytrace.c	1994/01/12 20:42:34	2.10
@@ -1,4 +1,4 @@
-/* Copyright (c) 1991 Regents of the University of California */
+/* Copyright (c) 1994 Regents of the University of California */
 
 #ifndef lint
 static char SCCSid[] = "$SunId$ LBL";
@@ -18,13 +18,15 @@ 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  raynum = 0L;			/* next unique ray number */
-long  nrays = 0L;			/* number of calls to localhit */
+unsigned long  raynum = 0;		/* next unique ray number */
+unsigned long  nrays = 0;		/* number of calls to localhit */
 
 static FLOAT  Lambfa[5] = {PI, PI, PI, 0.0, 0.0};
 OBJREC  Lamb = {
@@ -32,6 +34,8 @@ OBJREC  Lamb = {
 	{0, 5, NULL, Lambfa}, NULL,
 };					/* a Lambertian surface */
 
+static int  raymove(), checkset(), checkhit();
+
 #define  MAXLOOP	128		/* modifier loop detection */
 
 #define  RAYHIT		(-1)		/* return value for intercepted ray */
@@ -73,7 +77,6 @@ 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;
@@ -88,12 +91,16 @@ raytrace(r)			/* trace a ray and compute its value */
 RAY  *r;
 {
 	extern int  (*trace)();
+	int  gotmat;
 
 	if (localhit(r, &thescene))
-		raycont(r);
+		gotmat = raycont(r);
 	else if (sourcehit(r))
-		rayshade(r, r->ro->omod);
+		gotmat = rayshade(r, r->ro->omod);
 
+	if (!gotmat)
+		objerror(r->ro, USER, "material not found");
+
 	if (trace != NULL)
 		(*trace)(r);		/* trace execution */
 }
@@ -102,10 +109,12 @@ RAY  *r;
 raycont(r)			/* check for clipped object and continue */
 register RAY  *r;
 {
-	if (r->clipset != NULL && inset(r->clipset, r->ro->omod))
+	if ((r->clipset != NULL && inset(r->clipset, r->ro->omod)) ||
+			r->ro->omod == OVOID) {
 		raytrans(r);
-	else
-		rayshade(r, r->ro->omod);
+		return(1);
+	}
+	return(rayshade(r, r->ro->omod));
 }
 
 
@@ -128,12 +137,13 @@ register RAY  *r;
 int  mod;
 {
 	static int  depth = 0;
+	int  gotmat;
 	register OBJREC  *m;
 					/* 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) {
+	for (gotmat = 0; !gotmat && mod != OVOID; mod = m->omod) {
 		m = objptr(mod);
 		/****** unnecessary test since modifier() is always called
 		if (!ismodifier(m->otype)) {
@@ -151,13 +161,11 @@ int  mod;
 			if (!islight(m->otype))
 				m = &Lamb;
 		}
-		(*ofun[m->otype].funp)(m, r);	/* execute function */
-		if (ismaterial(m->otype)) {	/* materials call raytexture */
-			depth--;
-			return;		/* we're done */
-		}
+					/* materials call raytexture */
+		gotmat = (*ofun[m->otype].funp)(m, r);
 	}
-	objerror(r->ro, USER, "material not found");
+	depth--;
+	return(gotmat);
 }
 
 
@@ -173,11 +181,14 @@ int  mod;
 					/* execute textures and patterns */
 	for ( ; mod != OVOID; mod = m->omod) {
 		m = objptr(mod);
-		if (!istexture(m->otype)) {
+		/****** unnecessary test since modifier() is always called
+		if (!ismodifier(m->otype)) {
 			sprintf(errmsg, "illegal modifier \"%s\"", m->oname);
 			error(USER, errmsg);
 		}
-		(*ofun[m->otype].funp)(m, r);
+		******/
+		if ((*ofun[m->otype].funp)(m, r))
+			objerror(r->ro, USER, "conflicting materials");
 	}
 	depth--;			/* end here */
 }
@@ -188,44 +199,54 @@ register RAY  *r;
 OBJECT  fore, back;
 double  coef;
 {
-	FVECT  curpert, forepert, backpert;
-	COLOR  curpcol, forepcol, backpcol;
+	RAY  fr, br;
+	COLOR  ctmp;
+	int  foremat, backmat;
 	register int  i;
 					/* clip coefficient */
 	if (coef > 1.0)
 		coef = 1.0;
 	else if (coef < 0.0)
 		coef = 0.0;
-					/* save current mods */
-	VCOPY(curpert, r->pert);
-	copycolor(curpcol, r->pcol);
-					/* compute new mods */
-						/* foreground */
-	r->pert[0] = r->pert[1] = r->pert[2] = 0.0;
-	setcolor(r->pcol, 1.0, 1.0, 1.0);
+					/* foreground */
+	copystruct(&fr, r);
+	fr.pert[0] = fr.pert[1] = fr.pert[2] = 0.0;
+	setcolor(fr.pcol, 1.0, 1.0, 1.0);
+	setcolor(fr.rcol, 0.0, 0.0, 0.0);
 	if (fore != OVOID && coef > FTINY)
-		raytexture(r, fore);
-	VCOPY(forepert, r->pert);
-	copycolor(forepcol, r->pcol);
-						/* background */
-	r->pert[0] = r->pert[1] = r->pert[2] = 0.0;
-	setcolor(r->pcol, 1.0, 1.0, 1.0);
+		foremat = rayshade(&fr, fore);
+	else
+		foremat = 0;
+					/* background */
+	copystruct(&br, r);
+	br.pert[0] = br.pert[1] = br.pert[2] = 0.0;
+	setcolor(br.pcol, 1.0, 1.0, 1.0);
+	setcolor(br.rcol, 0.0, 0.0, 0.0);
 	if (back != OVOID && coef < 1.0-FTINY)
-		raytexture(r, back);
-	VCOPY(backpert, r->pert);
-	copycolor(backpcol, r->pcol);
+		backmat = rayshade(&br, back);
+	else
+		backmat = foremat;
+					/* check */
+	if (backmat != foremat)
+		objerror(r->ro, USER, "mixing material with non-material");
 					/* sum perturbations */
 	for (i = 0; i < 3; i++)
-		r->pert[i] = curpert[i] + coef*forepert[i] +
-				(1.0-coef)*backpert[i];
-					/* multiply colors */
-	setcolor(r->pcol, coef*colval(forepcol,RED) +
-				(1.0-coef)*colval(backpcol,RED),
-			coef*colval(forepcol,GRN) +
-				(1.0-coef)*colval(backpcol,GRN),
-			coef*colval(forepcol,BLU) +
-				(1.0-coef)*colval(backpcol,BLU));
-	multcolor(r->pcol, curpcol);
+		r->pert[i] += coef*fr.pert[i] + (1.0-coef)*br.pert[i];
+					/* multiply pattern colors */
+	scalecolor(fr.pcol, coef);
+	scalecolor(br.pcol, 1.0-coef);
+	copycolor(ctmp, fr.pcol);
+	addcolor(ctmp, br.pcol);
+	multcolor(r->pcol, ctmp);
+					/* sum returned ray values */
+	scalecolor(fr.rcol, coef);
+	scalecolor(br.rcol, 1.0-coef);
+	addcolor(r->rcol, fr.rcol);
+	addcolor(r->rcol, br.rcol);
+	if (foremat)
+		r->rt = bright(fr.rcol) > bright(br.rcol) ? fr.rt : br.rt;
+					/* return value tells if material */
+	return(foremat);
 }
 
 
@@ -317,6 +338,7 @@ 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;
@@ -326,9 +348,9 @@ register CUBE  *scene;
 	sflags = 0;
 	for (i = 0; i < 3; i++) {
 		curpos[i] = r->rorg[i];
-		if (r->rdir[i] > FTINY)
+		if (r->rdir[i] > 1e-7)
 			sflags |= 1 << i;
-		else if (r->rdir[i] < -FTINY)
+		else if (r->rdir[i] < -1e-7)
 			sflags |= 0x10 << i;
 	}
 	if (sflags == 0)
@@ -357,13 +379,15 @@ 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;
@@ -392,7 +416,7 @@ 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? */
@@ -411,7 +435,7 @@ 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) {
@@ -444,16 +468,17 @@ 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, r->cxs);			/* eliminate double-checking */
+	checkset(oset, cxs);			/* eliminate double-checking */
 	for (i = oset[0]; i > 0; i--) {
 		o = objptr(oset[i]);
 		(*ofun[o->otype].funp)(o, r);
@@ -467,11 +492,12 @@ CUBE  *cu;
 
 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 */
+register OBJECT  *os;			/* os' = os - cs */
+register OBJECT  *cs;			/* cs' = cs + os */
 {
 	OBJECT  cset[MAXCSET+MAXSET+1];
-	register int  i, j, k;
+	register int  i, j;
+	int  k;
 					/* copy os in place, cset <- cs */
 	cset[0] = 0;
 	k = 0;
@@ -483,10 +509,14 @@ register OBJECT  cs[MAXCSET+1];		/* cs' = cs + os */
 			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 if necessary */
+	if (cset[0] > MAXCSET)		/* truncate "checked" set if nec. */
 		cset[0] = MAXCSET;
-	setcopy(cs, cset);		/* copy new "checked" set back */
-	os[0] = k;			/* new "to check" set size */
+	/* setcopy(cs, cset); */	/* copy cset back to cs */
+	os = cset;
+	for (i = os[0]; i-- >= 0; )
+		*cs++ = *os++;
 }