--- ray/src/rt/m_brdf.c	2004/03/30 16:13:01	2.21
+++ ray/src/rt/m_brdf.c	2019/02/13 02:38:26	2.38
@@ -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 2.38 2019/02/13 02:38:26 greg Exp $";
 #endif
 /*
  *  Shading for materials with arbitrary BRDF's
@@ -14,6 +14,7 @@ static const char	RCSid[] = "$Id: m_brdf.c,v 2.21 2004
 #include  "otypes.h"
 #include  "rtotypes.h"
 #include  "func.h"
+#include  "pmapmat.h"
 
 /*
  *	Arguments to this material include the color and specularity.
@@ -38,12 +39,12 @@ static const char	RCSid[] = "$Id: m_brdf.c,v 2.21 2004
  *  Arguments for MAT_TFUNC are:
  *	2+	func	funcfile	transform
  *	0
- *	4+	red	grn	blu	rspec	trans	tspec	A7 ..
+ *	6+	red	grn	blu	rspec	trans	tspec	A7 ..
  *
  *  Arguments for MAT_TDATA are:
  *	4+	func	datafile	funcfile	v0 ..	transform
  *	0
- *	4+	red	grn	blu	rspec	trans	tspec	A7 ..
+ *	6+	red	grn	blu	rspec	trans	tspec	A7 ..
  *
  *  Arguments for the more general MAT_BRTDF are:
  *	10+	rrefl	grefl	brefl
@@ -77,8 +78,7 @@ typedef struct {
 }  BRDFDAT;		/* BRDF material data */
 
 
-static srcdirf_t dirbrdf;
-static int setbrdfunc(BRDFDAT  *np);
+static int setbrdfunc(BRDFDAT *np);
 
 
 static void
@@ -89,14 +89,14 @@ dirbrdf(		/* compute source contribution */
 	double  omega			/* light source size */
 )
 {
-	register BRDFDAT *np = nnp;
+	BRDFDAT *np = nnp;
 	double  ldot;
 	double  dtmp;
 	COLOR  ctmp;
 	FVECT  ldx;
 	static double  vldx[5], pt[MAXDIM];
-	register char	**sa;
-	register int	i;
+	char	**sa;
+	int	i;
 #define lddx (vldx+1)
 
 	setcolor(cval, 0.0, 0.0, 0.0);
@@ -128,8 +128,9 @@ dirbrdf(		/* compute source contribution */
 		scalecolor(ctmp, dtmp);
 		addcolor(cval, ctmp);
 	}
-	if (ldot > 0.0 ? np->rspec <= FTINY : np->tspec <= FTINY)
-		return;		/* no specular component */
+	if ((ldot > 0.0 ? np->rspec <= FTINY : np->tspec <= FTINY) ||
+			ambRayInPmap(np->pr))
+		return;		/* diffuse only */
 					/* set up function */
 	setbrdfunc(np);
 	sa = np->mp->oargs.sarg;
@@ -141,15 +142,19 @@ dirbrdf(		/* compute source contribution */
 	lddx[3] = omega;
 					/* compute BRTDF */
 	if (np->mp->otype == MAT_BRTDF) {
-		if (sa[6][0] == '0')		/* special case */
+		if (sa[6][0] == '0' && !sa[6][1])	/* special case */
 			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' && !sa[7][1])
+			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);
-		if (!strcmp(sa[8],sa[6]))
+		if (sa[8][0] == '0' && !sa[8][1])
+			colval(ctmp,BLU) = 0.0;
+		else if (!strcmp(sa[8],sa[6]))
 			colval(ctmp,BLU) = colval(ctmp,RED);
 		else if (!strcmp(sa[8],sa[7]))
 			colval(ctmp,BLU) = colval(ctmp,GRN);
@@ -166,7 +171,7 @@ 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;
 	}
@@ -195,21 +200,22 @@ dirbrdf(		/* compute source contribution */
 }
 
 
-extern int
+int
 m_brdf(			/* color a ray that hit a BRDTfunc material */
-	register OBJREC  *m,
-	register RAY  *r
+	OBJREC  *m,
+	RAY  *r
 )
 {
 	int  hitfront = 1;
 	BRDFDAT  nd;
 	RAY  sr;
-	double  transtest, transdist;
 	int  hasrefl, hastrans;
+	int  hastexture;
 	COLOR  ctmp;
 	FVECT  vtmp;
-	register MFUNC  *mf;
-	register int  i;
+	double  d;
+	MFUNC  *mf;
+	int  i;
 						/* check arguments */
 	if ((m->oargs.nsargs < 10) | (m->oargs.nfargs < 9))
 		objerror(m, USER, "bad # arguments");
@@ -233,7 +239,13 @@ 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++) {
@@ -245,63 +257,65 @@ m_brdf(			/* color a ray that hit a BRDTfunc material 
 	copycolor(nd.mcolor, r->pcol);		/* get pattern color */
 	multcolor(nd.rdiff, nd.mcolor);		/* modify diffuse values */
 	multcolor(nd.tdiff, nd.mcolor);
-	hasrefl = bright(nd.rdiff) > FTINY;
-	hastrans = bright(nd.tdiff) > FTINY;
+	hasrefl = (bright(nd.rdiff) > FTINY);
+	hastrans = (bright(nd.tdiff) > FTINY);
 						/* load cal file */
 	nd.dp = NULL;
 	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 (hastexture && !(r->crtype & (SHADOW|AMBIENT))) {
+						/* perturb direction */
+			VSUB(sr.rdir, r->rdir, r->pert);
 			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 || r->crtype & (SHADOW|AMBIENT)) &&
+				nd.tspec > bright(nd.tdiff) + bright(nd.rdiff))
+			r->rxt = r->rot + raydistance(&sr);
 	}
 	if (r->crtype & SHADOW)			/* the rest is shadow */
 		return(1);
+
 						/* compute reflected ray */
 	setbrdfunc(&nd);
 	errno = 0;
 	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);
+		copycolor(r->mcol, sr.rcol);
 		addcolor(r->rcol, sr.rcol);
+		if (r->ro != NULL && isflat(r->ro->otype) &&
+				!hastexture | (r->crtype & AMBIENT))
+			r->rmt = r->rot + raydistance(&sr);
 	}
 						/* 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);
@@ -312,27 +326,24 @@ 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))
-		r->rt = transdist;
 
 	return(1);
 }
 
 
 
-extern int
+int
 m_brdf2(			/* color a ray that hit a BRDF material */
-	register OBJREC  *m,
-	register RAY  *r
+	OBJREC  *m,
+	RAY  *r
 )
 {
 	BRDFDAT  nd;
@@ -348,8 +359,7 @@ m_brdf2(			/* color a ray that hit a BRDF material */
 		objerror(m, USER, "bad # arguments");
 						/* check for back side */
 	if (r->rod < 0.0) {
-		if (!backvis && m->otype != MAT_TFUNC
-				&& m->otype != MAT_TDATA) {
+		if (!backvis) {
 			raytrans(r);
 			return(1);
 		}
@@ -393,19 +403,19 @@ 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 */
+	if (nd.trans > FTINY) {			/* from other side */
 		flipsurface(r);
 		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);
 	}
@@ -418,7 +428,7 @@ m_brdf2(			/* color a ray that hit a BRDF material */
 
 static int
 setbrdfunc(			/* set up brdf function and variables */
-	register BRDFDAT  *np
+	BRDFDAT  *np
 )
 {
 	FVECT  vec;
@@ -427,10 +437,10 @@ setbrdfunc(			/* set up brdf function and variables */
 		return(0);	/* it's OK, setfunc says we're done */
 				/* else (re)assign special variables */
 	multv3(vec, np->pnorm, funcxf.xfm);
-	varset("NxP", '=', vec[0]/funcxf.sca);
-	varset("NyP", '=', vec[1]/funcxf.sca);
-	varset("NzP", '=', vec[2]/funcxf.sca);
-	varset("RdotP", '=', np->pdot <= -1.0 ? -1.0 :
+	varset("NxP`", '=', vec[0]/funcxf.sca);
+	varset("NyP`", '=', vec[1]/funcxf.sca);
+	varset("NzP`", '=', vec[2]/funcxf.sca);
+	varset("RdotP`", '=', np->pdot <= -1.0 ? -1.0 :
 			np->pdot >= 1.0 ? 1.0 : np->pdot);
 	varset("CrP", '=', colval(np->mcolor,RED));
 	varset("CgP", '=', colval(np->mcolor,GRN));