--- ray/src/rt/m_brdf.c	2004/03/30 16:13:01	2.21
+++ ray/src/rt/m_brdf.c	2010/10/25 22:57:45	2.27
@@ -1,5 +1,5 @@
 #ifndef lint
-static const char	RCSid[] = "$Id: m_brdf.c,v 2.21 2004/03/30 16:13:01 schorsch Exp $";
+static const char	RCSid[] = "$Id: m_brdf.c,v 2.27 2010/10/25 22:57:45 greg Exp $";
 #endif
 /*
  *  Shading for materials with arbitrary BRDF's
@@ -129,7 +129,7 @@ dirbrdf(		/* compute source contribution */
 		addcolor(cval, ctmp);
 	}
 	if (ldot > 0.0 ? np->rspec <= FTINY : np->tspec <= FTINY)
-		return;		/* no specular component */
+		return;		/* diffuse only */
 					/* set up function */
 	setbrdfunc(np);
 	sa = np->mp->oargs.sarg;
@@ -145,7 +145,9 @@ dirbrdf(		/* compute source contribution */
 			colval(ctmp,RED) = 0.0;
 		else
 			colval(ctmp,RED) = funvalue(sa[6], 4, lddx);
-		if (!strcmp(sa[7],sa[6]))
+		if (sa[7][0] == '0')
+			colval(ctmp,GRN) = 0.0;
+		else if (!strcmp(sa[7],sa[6]))
 			colval(ctmp,GRN) = colval(ctmp,RED);
 		else
 			colval(ctmp,GRN) = funvalue(sa[7], 4, lddx);
@@ -166,7 +168,7 @@ dirbrdf(		/* compute source contribution */
 		dtmp = funvalue(sa[0], 5, vldx);
 		setcolor(ctmp, dtmp, dtmp, dtmp);
 	}
-	if (errno == EDOM || errno == ERANGE) {
+	if ((errno == EDOM) | (errno == ERANGE)) {
 		objerror(np->mp, WARNING, "compute error");
 		return;
 	}
@@ -204,10 +206,13 @@ m_brdf(			/* color a ray that hit a BRDTfunc material 
 	int  hitfront = 1;
 	BRDFDAT  nd;
 	RAY  sr;
+	double  mirtest=0, mirdist=0;
 	double  transtest, transdist;
 	int  hasrefl, hastrans;
+	int  hastexture;
 	COLOR  ctmp;
 	FVECT  vtmp;
+	double  d;
 	register MFUNC  *mf;
 	register int  i;
 						/* check arguments */
@@ -233,7 +238,13 @@ m_brdf(			/* color a ray that hit a BRDTfunc material 
 			m->oargs.farg[8]);
 						/* get modifiers */
 	raytexture(r, m->omod);
-	nd.pdot = raynormal(nd.pnorm, r);	/* perturb normal */
+	hastexture = DOT(r->pert,r->pert) > FTINY*FTINY;
+	if (hastexture) {			/* perturb normal */
+		nd.pdot = raynormal(nd.pnorm, r);
+	} else {
+		VCOPY(nd.pnorm, r->ron);
+		nd.pdot = r->rod;
+	}
 	if (r->rod < 0.0) {			/* orient perturbed values */
 		nd.pdot = -nd.pdot;
 		for (i = 0; i < 3; i++) {
@@ -252,32 +263,30 @@ m_brdf(			/* color a ray that hit a BRDTfunc material 
 	mf = getfunc(m, 9, 0x3f, 0);
 						/* compute transmitted ray */
 	setbrdfunc(&nd);
-	transtest = 0;
-	transdist = r->rot;
 	errno = 0;
 	setcolor(ctmp, evalue(mf->ep[3]),
 			evalue(mf->ep[4]),
 			evalue(mf->ep[5]));
-	if (errno == EDOM || errno == ERANGE)
+	if ((errno == EDOM) | (errno == ERANGE))
 		objerror(m, WARNING, "compute error");
-	else if (rayorigin(&sr, r, TRANS, bright(ctmp)) == 0) {
-		if (!(r->crtype & SHADOW) &&
-				DOT(r->pert,r->pert) > FTINY*FTINY) {
-			for (i = 0; i < 3; i++)	/* perturb direction */
-				sr.rdir[i] = r->rdir[i] - .75*r->pert[i];
+	else if (rayorigin(&sr, TRANS, r, ctmp) == 0) {
+		if (!(r->crtype & SHADOW) && hastexture) {
+						/* perturb direction */
+			VSUM(sr.rdir, r->rdir, r->pert, -.75);
 			if (normalize(sr.rdir) == 0.0) {
 				objerror(m, WARNING, "illegal perturbation");
 				VCOPY(sr.rdir, r->rdir);
 			}
 		} else {
 			VCOPY(sr.rdir, r->rdir);
-			transtest = 2;
 		}
 		rayvalue(&sr);
-		multcolor(sr.rcol, ctmp);
+		multcolor(sr.rcol, sr.rcoef);
 		addcolor(r->rcol, sr.rcol);
-		transtest *= bright(sr.rcol);
-		transdist = r->rot + sr.rt;
+		if (!hastexture) {
+			transtest = 2.0*bright(sr.rcol);
+			transdist = r->rot + sr.rt;
+		}
 	}
 	if (r->crtype & SHADOW)			/* the rest is shadow */
 		return(1);
@@ -287,21 +296,25 @@ m_brdf(			/* color a ray that hit a BRDTfunc material 
 	setcolor(ctmp, evalue(mf->ep[0]),
 			evalue(mf->ep[1]),
 			evalue(mf->ep[2]));
-	if (errno == EDOM || errno == ERANGE)
+	if ((errno == EDOM) | (errno == ERANGE))
 		objerror(m, WARNING, "compute error");
-	else if (rayorigin(&sr, r, REFLECTED, bright(ctmp)) == 0) {
-		for (i = 0; i < 3; i++)
-			sr.rdir[i] = r->rdir[i] + 2.0*nd.pdot*nd.pnorm[i];
+	else if (rayorigin(&sr, REFLECTED, r, ctmp) == 0) {
+		VSUM(sr.rdir, r->rdir, nd.pnorm, 2.*nd.pdot);
+		checknorm(sr.rdir);
 		rayvalue(&sr);
-		multcolor(sr.rcol, ctmp);
+		multcolor(sr.rcol, sr.rcoef);
 		addcolor(r->rcol, sr.rcol);
+		if (!hastexture && r->ro != NULL && isflat(r->ro->otype)) {
+			mirtest = 2.0*bright(sr.rcol);
+			mirdist = r->rot + sr.rt;
+		}
 	}
 						/* compute ambient */
 	if (hasrefl) {
 		if (!hitfront)
 			flipsurface(r);
-		ambient(ctmp, r, nd.pnorm);
-		multcolor(ctmp, nd.rdiff);
+		copycolor(ctmp, nd.rdiff);
+		multambient(ctmp, r, nd.pnorm);
 		addcolor(r->rcol, ctmp);	/* add to returned color */
 		if (!hitfront)
 			flipsurface(r);
@@ -312,17 +325,20 @@ m_brdf(			/* color a ray that hit a BRDTfunc material 
 		vtmp[0] = -nd.pnorm[0];
 		vtmp[1] = -nd.pnorm[1];
 		vtmp[2] = -nd.pnorm[2];
-		ambient(ctmp, r, vtmp);
-		multcolor(ctmp, nd.tdiff);
+		copycolor(ctmp, nd.tdiff);
+		multambient(ctmp, r, vtmp);
 		addcolor(r->rcol, ctmp);
 		if (hitfront)
 			flipsurface(r);
 	}
 	if (hasrefl | hastrans || m->oargs.sarg[6][0] != '0')
 		direct(r, dirbrdf, &nd);	/* add direct component */
-						/* check distance */
-	if (transtest > bright(r->rcol))
+
+	d = bright(r->rcol);			/* set effective distance */
+	if (transtest > d)
 		r->rt = transdist;
+	else if (mirtest > d)
+		r->rt = mirdist;
 
 	return(1);
 }
@@ -393,9 +409,9 @@ m_brdf2(			/* color a ray that hit a BRDF material */
 	}
 						/* compute ambient */
 	if (nd.trans < 1.0-FTINY) {
-		ambient(ctmp, r, nd.pnorm);
+		copycolor(ctmp, nd.mcolor);	/* modified by material color */
 		scalecolor(ctmp, 1.0-nd.trans);
-		multcolor(ctmp, nd.mcolor);	/* modified by material color */
+		multambient(ctmp, r, nd.pnorm);
 		addcolor(r->rcol, ctmp);	/* add to returned color */
 	}
 	if (nd.trans > FTINY) {		/* from other side */
@@ -403,9 +419,9 @@ m_brdf2(			/* color a ray that hit a BRDF material */
 		vtmp[0] = -nd.pnorm[0];
 		vtmp[1] = -nd.pnorm[1];
 		vtmp[2] = -nd.pnorm[2];
-		ambient(ctmp, r, vtmp);
+		copycolor(ctmp, nd.mcolor);
 		scalecolor(ctmp, nd.trans);
-		multcolor(ctmp, nd.mcolor);
+		multambient(ctmp, r, vtmp);
 		addcolor(r->rcol, ctmp);
 		flipsurface(r);
 	}