--- ray/src/cv/bsdfrep.c	2012/11/22 06:07:17	2.11
+++ ray/src/cv/bsdfrep.c	2014/03/07 21:21:02	2.21
@@ -1,5 +1,5 @@
 #ifndef lint
-static const char RCSid[] = "$Id: bsdfrep.c,v 2.11 2012/11/22 06:07:17 greg Exp $";
+static const char RCSid[] = "$Id: bsdfrep.c,v 2.21 2014/03/07 21:21:02 greg Exp $";
 #endif
 /*
  * Support BSDF representation as radial basis functions.
@@ -14,6 +14,9 @@ static const char RCSid[] = "$Id: bsdfrep.c,v 2.11 201
 #include "rtio.h"
 #include "resolu.h"
 #include "bsdfrep.h"
+				/* name and manufacturer if known */
+char			bsdf_name[256];
+char			bsdf_manuf[256];
 				/* active grid resolution */
 int			grid_res = GRIDRES;
 
@@ -26,6 +29,12 @@ int			single_plane_incident = -1;
 int			input_orient = 0;
 int			output_orient = 0;
 
+				/* BSDF histogram */
+unsigned long		bsdf_hist[HISTLEN];
+
+				/* BSDF value for boundary regions */
+double			bsdf_min = 0;
+
 				/* processed incident DSF measurements */
 RBFNODE			*dsf_list = NULL;
 
@@ -199,15 +208,6 @@ rotate_rbf(RBFNODE *rbf, const FVECT invec)
 	VCOPY(rbf->invec, invec);
 }
 
-/* Compute volume associated with Gaussian lobe */
-double
-rbf_volume(const RBFVAL *rbfp)
-{
-	double	rad = R2ANG(rbfp->crad);
-
-	return((2.*M_PI) * rbfp->peak * rad*rad);
-}
-
 /* Compute outgoing vector from grid position */
 void
 ovec_from_pos(FVECT vec, int xpos, int ypos)
@@ -237,26 +237,60 @@ pos_from_vec(int pos[2], const FVECT vec)
 	pos[1] = (int)(sq[1]*grid_res);
 }
 
+/* Compute volume associated with Gaussian lobe */
+double
+rbf_volume(const RBFVAL *rbfp)
+{
+	double	rad = R2ANG(rbfp->crad);
+	FVECT	odir;
+	double	elev, integ;
+				/* infinite integral approximation */
+	integ = (2.*M_PI) * rbfp->peak * rad*rad;
+				/* check if we're near horizon */
+	ovec_from_pos(odir, rbfp->gx, rbfp->gy);
+	elev = output_orient*odir[2];
+				/* apply cut-off correction if > 1% */
+	if (elev < 2.8*rad) {
+		/* elev = asin(elev);	/* this is so crude, anyway... */
+		integ *= 1. - .5*exp(-.5*elev*elev/(rad*rad));
+	}
+	return(integ);
+}
+
 /* Evaluate RBF for DSF at the given normalized outgoing direction */
 double
 eval_rbfrep(const RBFNODE *rp, const FVECT outvec)
 {
+	const double	rfact2 = (38./M_PI/M_PI)*(grid_res*grid_res);
+	double		minval = bsdf_min*output_orient*outvec[2];
+	int		pos[2];
 	double		res = 0;
 	const RBFVAL	*rbfp;
 	FVECT		odir;
-	double		sig2;
+	double		rad2;
 	int		n;
-
-	if (rp == NULL)
+				/* check for wrong side */
+	if (outvec[2] > 0 ^ output_orient > 0)
 		return(.0);
+				/* use minimum if no information avail. */
+	if (rp == NULL)
+		return(minval);
+				/* optimization for fast lobe culling */
+	pos_from_vec(pos, outvec);
+				/* sum radial basis function */
 	rbfp = rp->rbfa;
 	for (n = rp->nrbf; n--; rbfp++) {
+		int	d2 = (pos[0]-rbfp->gx)*(pos[0]-rbfp->gx) +
+				(pos[1]-rbfp->gy)*(pos[1]-rbfp->gy);
+		rad2 = R2ANG(rbfp->crad);
+		rad2 *= rad2;
+		if (d2 > rad2*rfact2)
+			continue;
 		ovec_from_pos(odir, rbfp->gx, rbfp->gy);
-		sig2 = R2ANG(rbfp->crad);
-		sig2 = (DOT(odir,outvec) - 1.) / (sig2*sig2);
-		if (sig2 > -19.)
-			res += rbfp->peak * exp(sig2);
+		res += rbfp->peak * exp((DOT(odir,outvec) - 1.) / rad2);
 	}
+	if (res < minval)	/* never return less than minval */
+		return(minval);
 	return(res);
 }
 
@@ -359,6 +393,92 @@ get_triangles(RBFNODE *rbfv[2], const MIGRATION *mig)
 	return((rbfv[0] != NULL) + (rbfv[1] != NULL));
 }
 
+/* Advect and allocate new RBF along edge (internal call) */
+RBFNODE *
+e_advect_rbf(const MIGRATION *mig, const FVECT invec, int lobe_lim)
+{
+	double		cthresh = FTINY;
+	RBFNODE		*rbf;
+	int		n, i, j;
+	double		t, full_dist;
+						/* get relative position */
+	t = Acos(DOT(invec, mig->rbfv[0]->invec));
+	if (t < M_PI/grid_res) {		/* near first DSF */
+		n = sizeof(RBFNODE) + sizeof(RBFVAL)*(mig->rbfv[0]->nrbf-1);
+		rbf = (RBFNODE *)malloc(n);
+		if (rbf == NULL)
+			goto memerr;
+		memcpy(rbf, mig->rbfv[0], n);	/* just duplicate */
+		rbf->next = NULL; rbf->ejl = NULL;
+		return(rbf);
+	}
+	full_dist = acos(DOT(mig->rbfv[0]->invec, mig->rbfv[1]->invec));
+	if (t > full_dist-M_PI/grid_res) {	/* near second DSF */
+		n = sizeof(RBFNODE) + sizeof(RBFVAL)*(mig->rbfv[1]->nrbf-1);
+		rbf = (RBFNODE *)malloc(n);
+		if (rbf == NULL)
+			goto memerr;
+		memcpy(rbf, mig->rbfv[1], n);	/* just duplicate */
+		rbf->next = NULL; rbf->ejl = NULL;
+		return(rbf);
+	}
+	t /= full_dist;
+tryagain:
+	n = 0;					/* count migrating particles */
+	for (i = 0; i < mtx_nrows(mig); i++)
+	    for (j = 0; j < mtx_ncols(mig); j++)
+		n += (mtx_coef(mig,i,j) > cthresh);
+						/* are we over our limit? */
+	if ((lobe_lim > 0) & (n > lobe_lim)) {
+		cthresh = cthresh*2. + 10.*FTINY;
+		goto tryagain;
+	}
+#ifdef DEBUG
+	fprintf(stderr, "Input RBFs have %d, %d nodes -> output has %d\n",
+			mig->rbfv[0]->nrbf, mig->rbfv[1]->nrbf, n);
+#endif
+	rbf = (RBFNODE *)malloc(sizeof(RBFNODE) + sizeof(RBFVAL)*(n-1));
+	if (rbf == NULL)
+		goto memerr;
+	rbf->next = NULL; rbf->ejl = NULL;
+	VCOPY(rbf->invec, invec);
+	rbf->nrbf = n;
+	rbf->vtotal = 1.-t + t*mig->rbfv[1]->vtotal/mig->rbfv[0]->vtotal;
+	n = 0;					/* advect RBF lobes */
+	for (i = 0; i < mtx_nrows(mig); i++) {
+	    const RBFVAL	*rbf0i = &mig->rbfv[0]->rbfa[i];
+	    const float		peak0 = rbf0i->peak;
+	    const double	rad0 = R2ANG(rbf0i->crad);
+	    FVECT		v0;
+	    float		mv;
+	    ovec_from_pos(v0, rbf0i->gx, rbf0i->gy);
+	    for (j = 0; j < mtx_ncols(mig); j++)
+		if ((mv = mtx_coef(mig,i,j)) > cthresh) {
+			const RBFVAL	*rbf1j = &mig->rbfv[1]->rbfa[j];
+			double		rad2;
+			FVECT		v;
+			int		pos[2];
+			rad2 = R2ANG(rbf1j->crad);
+			rad2 = rad0*rad0*(1.-t) + rad2*rad2*t;
+			rbf->rbfa[n].peak = peak0 * mv * rbf->vtotal *
+						rad0*rad0/rad2;
+			rbf->rbfa[n].crad = ANG2R(sqrt(rad2));
+			ovec_from_pos(v, rbf1j->gx, rbf1j->gy);
+			geodesic(v, v0, v, t, GEOD_REL);
+			pos_from_vec(pos, v);
+			rbf->rbfa[n].gx = pos[0];
+			rbf->rbfa[n].gy = pos[1];
+			++n;
+		}
+	}
+	rbf->vtotal *= mig->rbfv[0]->vtotal;	/* turn ratio into actual */
+	return(rbf);
+memerr:
+	fprintf(stderr, "%s: Out of memory in e_advect_rbf()\n", progname);
+	exit(1);
+	return(NULL);	/* pro forma return */
+}
+
 /* Clear our BSDF representation and free memory */
 void
 clear_bsdf_rep(void)
@@ -373,6 +493,8 @@ clear_bsdf_rep(void)
 		dsf_list = rbf->next;
 		free(rbf);
 	}
+	bsdf_name[0] = '\0';
+	bsdf_manuf[0] = '\0';
 	inp_coverage = 0;
 	single_plane_incident = -1;
 	input_orient = output_orient = 0;
@@ -387,9 +509,14 @@ save_bsdf_rep(FILE *ofp)
 	MIGRATION	*mig;
 	int		i, n;
 					/* finish header */
+	if (bsdf_name[0])
+		fprintf(ofp, "NAME=%s\n", bsdf_name);
+	if (bsdf_manuf[0])
+		fprintf(ofp, "MANUFACT=%s\n", bsdf_manuf);
 	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 */
@@ -442,6 +569,14 @@ headline(char *s, void *p)
 {
 	char	fmt[32];
 
+	if (!strncmp(s, "NAME=", 5)) {
+		strcpy(bsdf_name, s+5);
+		bsdf_name[strlen(bsdf_name)-1] = '\0';
+	}
+	if (!strncmp(s, "MANUFACT=", 9)) {
+		strcpy(bsdf_manuf, s+9);
+		bsdf_manuf[strlen(bsdf_manuf)-1] = '\0';
+	}
 	if (!strncmp(s, "SYMMETRY=", 9)) {
 		inp_coverage = atoi(s+9);
 		single_plane_incident = !inp_coverage;
@@ -455,6 +590,10 @@ 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);
@@ -471,14 +610,13 @@ load_bsdf_rep(FILE *ifp)
 	clear_bsdf_rep();
 	if (ifp == NULL)
 		return(0);
-	if (getheader(ifp, headline, NULL) < 0 || single_plane_incident < 0 |
+	if (getheader(ifp, headline, NULL) < 0 || (single_plane_incident < 0) |
 			!input_orient | !output_orient) {
 		fprintf(stderr, "%s: missing/bad format for BSDF interpolant\n",
 				progname);
 		return(0);
 	}
-	rbfh.next = NULL;		/* read each DSF */
-	rbfh.ejl = NULL;
+	memset(&rbfh, 0, sizeof(rbfh));	/* read each DSF */
 	while ((rbfh.ord = getint(4, ifp)) >= 0) {
 		RBFNODE		*newrbf;
 
@@ -495,7 +633,7 @@ load_bsdf_rep(FILE *ifp)
 					sizeof(RBFVAL)*(rbfh.nrbf-1));
 		if (newrbf == NULL)
 			goto memerr;
-		memcpy(newrbf, &rbfh, sizeof(RBFNODE)-sizeof(RBFVAL));
+		*newrbf = rbfh;
 		for (i = 0; i < rbfh.nrbf; i++) {
 			newrbf->rbfa[i].peak = getflt(ifp);
 			newrbf->rbfa[i].crad = getint(2, ifp) & 0xffff;