--- ray/src/cv/bsdfrep.c	2012/11/07 03:04:23	2.5
+++ ray/src/cv/bsdfrep.c	2013/03/24 17:22:23	2.13
@@ -1,5 +1,5 @@
 #ifndef lint
-static const char RCSid[] = "$Id: bsdfrep.c,v 2.5 2012/11/07 03:04:23 greg Exp $";
+static const char RCSid[] = "$Id: bsdfrep.c,v 2.13 2013/03/24 17:22:23 greg Exp $";
 #endif
 /*
  * Support BSDF representation as radial basis functions.
@@ -26,6 +26,12 @@ int			single_plane_incident = -1;
 int			input_orient = 0;
 int			output_orient = 0;
 
+				/* BSDF histogram */
+int			bsdf_hist[HISTLEN];
+
+				/* BSDF value for boundary regions */
+double			bsdf_min = 0;
+
 				/* processed incident DSF measurements */
 RBFNODE			*dsf_list = NULL;
 
@@ -56,6 +62,8 @@ new_input_direction(double new_theta, double new_phi)
 		new_theta = -new_theta;
 		new_phi += 180.;
 	}
+	if ((theta_in_deg = new_theta) < 1.0)
+		return(1);		/* don't rely on phi near normal */
 	while (new_phi < 0)
 		new_phi += 360.;
 	while (new_phi >= 360.)
@@ -64,7 +72,6 @@ new_input_direction(double new_theta, double new_phi)
 		single_plane_incident = (round(new_phi) == round(phi_in_deg));
 	else if (single_plane_incident < 0)
 		single_plane_incident = 1;
-	theta_in_deg = new_theta;	/* assume it's OK */
 	phi_in_deg = new_phi;
 	if ((1. < new_phi) & (new_phi < 89.))
 		inp_coverage |= INP_QUAD1;
@@ -81,7 +88,7 @@ new_input_direction(double new_theta, double new_phi)
 int
 use_symmetry(FVECT vec)
 {
-	double	phi = get_phi360(vec);
+	const double	phi = get_phi360(vec);
 
 	switch (inp_coverage) {
 	case INP_QUAD1|INP_QUAD2|INP_QUAD3|INP_QUAD4:
@@ -177,6 +184,27 @@ rev_rbf_symmetry(RBFNODE *rbf, int sym)
 			rbf->rbfa[n].gy = grid_res-1 - rbf->rbfa[n].gy;
 }
 
+/* Rotate RBF to correspond to given incident vector */
+void
+rotate_rbf(RBFNODE *rbf, const FVECT invec)
+{
+	static const FVECT	vnorm = {.0, .0, 1.};
+	const double		phi = atan2(invec[1],invec[0]) -
+					atan2(rbf->invec[1],rbf->invec[0]);
+	FVECT			outvec;
+	int			pos[2];
+	int			n;
+
+	for (n = ((-.01 > phi) | (phi > .01))*rbf->nrbf; n-- > 0; ) {
+		ovec_from_pos(outvec, rbf->rbfa[n].gx, rbf->rbfa[n].gy);
+		spinvector(outvec, outvec, vnorm, phi);
+		pos_from_vec(pos, outvec);
+		rbf->rbfa[n].gx = pos[0];
+		rbf->rbfa[n].gy = pos[1];
+	}
+	VCOPY(rbf->invec, invec);
+}
+
 /* Compute volume associated with Gaussian lobe */
 double
 rbf_volume(const RBFVAL *rbfp)
@@ -193,7 +221,7 @@ ovec_from_pos(FVECT vec, int xpos, int ypos)
 	double	uv[2];
 	double	r2;
 	
-	SDsquare2disk(uv, (1./grid_res)*(xpos+.5), (1./grid_res)*(ypos+.5));
+	SDsquare2disk(uv, (xpos+.5)/grid_res, (ypos+.5)/grid_res);
 				/* uniform hemispherical projection */
 	r2 = uv[0]*uv[0] + uv[1]*uv[1];
 	vec[0] = vec[1] = sqrt(2. - r2);
@@ -219,14 +247,18 @@ pos_from_vec(int pos[2], const FVECT vec)
 double
 eval_rbfrep(const RBFNODE *rp, const FVECT outvec)
 {
-	double		res = .0;
+	double		minval = bsdf_min*output_orient*outvec[2];
+	double		res = 0;
 	const RBFVAL	*rbfp;
 	FVECT		odir;
 	double		sig2;
 	int		n;
-
-	if (rp == NULL)
-		return(.0);
+				/* use minimum if no information avail. */
+	if (rp == NULL) {
+		if (outvec[2] > 0 ^ output_orient > 0)
+			return(.0);
+		return(minval);
+	}
 	rbfp = rp->rbfa;
 	for (n = rp->nrbf; n--; rbfp++) {
 		ovec_from_pos(odir, rbfp->gx, rbfp->gy);
@@ -235,6 +267,8 @@ eval_rbfrep(const RBFNODE *rp, const FVECT outvec)
 		if (sig2 > -19.)
 			res += rbfp->peak * exp(sig2);
 	}
+	if (res < minval)	/* never return less than minval */
+		return(minval);
 	return(res);
 }
 
@@ -368,6 +402,7 @@ save_bsdf_rep(FILE *ofp)
 	fprintf(ofp, "SYMMETRY=%d\n", !single_plane_incident * inp_coverage);
 	fprintf(ofp, "IO_SIDES= %d %d\n", input_orient, output_orient);
 	fprintf(ofp, "GRIDRES=%d\n", grid_res);
+	fprintf(ofp, "BSDFMIN=%g\n", bsdf_min);
 	fputformat(BSDFREP_FMT, ofp);
 	fputc('\n', ofp);
 					/* write each DSF */
@@ -433,6 +468,10 @@ headline(char *s, void *p)
 		sscanf(s+8, "%d", &grid_res);
 		return(0);
 	}
+	if (!strncmp(s, "BSDFMIN=", 8)) {
+		sscanf(s+8, "%lf", &bsdf_min);
+		return(0);
+	}
 	if (formatval(fmt, s) && strcmp(fmt, BSDFREP_FMT))
 		return(-1);
 	return(0);
@@ -463,13 +502,17 @@ load_bsdf_rep(FILE *ifp)
 		rbfh.invec[0] = getflt(ifp);
 		rbfh.invec[1] = getflt(ifp);
 		rbfh.invec[2] = getflt(ifp);
+		if (normalize(rbfh.invec) == 0) {
+			fprintf(stderr, "%s: zero incident vector\n", progname);
+			return(0);
+		}
 		rbfh.vtotal = getflt(ifp);
 		rbfh.nrbf = getint(4, ifp);
 		newrbf = (RBFNODE *)malloc(sizeof(RBFNODE) +
 					sizeof(RBFVAL)*(rbfh.nrbf-1));
 		if (newrbf == NULL)
 			goto memerr;
-		memcpy(newrbf, &rbfh, sizeof(RBFNODE));
+		memcpy(newrbf, &rbfh, sizeof(RBFNODE)-sizeof(RBFVAL));
 		for (i = 0; i < rbfh.nrbf; i++) {
 			newrbf->rbfa[i].peak = getflt(ifp);
 			newrbf->rbfa[i].crad = getint(2, ifp) & 0xffff;