--- ray/src/cv/bsdfrep.c	2014/03/07 21:21:02	2.21
+++ ray/src/cv/bsdfrep.c	2021/11/17 01:39:04	2.36
@@ -1,5 +1,5 @@
 #ifndef lint
-static const char RCSid[] = "$Id: bsdfrep.c,v 2.21 2014/03/07 21:21:02 greg Exp $";
+static const char RCSid[] = "$Id: bsdfrep.c,v 2.36 2021/11/17 01:39:04 greg Exp $";
 #endif
 /*
  * Support BSDF representation as radial basis functions.
@@ -9,11 +9,11 @@ static const char RCSid[] = "$Id: bsdfrep.c,v 2.21 201
 
 #define _USE_MATH_DEFINES
 #include <stdlib.h>
-#include <string.h>
 #include <math.h>
 #include "rtio.h"
 #include "resolu.h"
 #include "bsdfrep.h"
+#include "random.h"
 				/* name and manufacturer if known */
 char			bsdf_name[256];
 char			bsdf_manuf[256];
@@ -29,11 +29,20 @@ int			single_plane_incident = -1;
 int			input_orient = 0;
 int			output_orient = 0;
 
+				/* represented color space */
+RBColor			rbf_colorimetry = RBCunknown;
+
+const char		*RBCident[] = {
+				"CIE-Y", "CIE-XYZ", "Spectral", "Unknown"
+			};
+
 				/* BSDF histogram */
 unsigned long		bsdf_hist[HISTLEN];
 
 				/* BSDF value for boundary regions */
 double			bsdf_min = 0;
+double			bsdf_spec_val = 0;
+double			bsdf_spec_rad = 0;
 
 				/* processed incident DSF measurements */
 RBFNODE			*dsf_list = NULL;
@@ -44,18 +53,13 @@ MIGRATION		*mig_list = NULL;
 				/* current input direction */
 double			theta_in_deg, phi_in_deg;
 
+				/* header line sharing callback */
+int			(*sir_headshare)(char *s) = NULL;
+
 /* Register new input direction */
 int
 new_input_direction(double new_theta, double new_phi)
 {
-	if (!input_orient)		/* check input orientation */
-		input_orient = 1 - 2*(new_theta > 90.);
-	else if (input_orient > 0 ^ new_theta < 90.) {
-		fprintf(stderr,
-		"%s: Cannot handle input angles on both sides of surface\n",
-				progname);
-		return(0);
-	}
 					/* normalize angle ranges */
 	while (new_theta < -180.)
 		new_theta += 360.;
@@ -65,12 +69,21 @@ 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.)
 		new_phi -= 360.;
+					/* check input orientation */
+	if (!input_orient)
+		input_orient = 1 - 2*(new_theta > 90.);
+	else if (input_orient > 0 ^ new_theta < 90.) {
+		fprintf(stderr,
+		"%s: Cannot handle input angles on both sides of surface\n",
+				progname);
+		return(0);
+	}
+	if ((theta_in_deg = new_theta) < 1.0)
+		return(1);		/* don't rely on phi near normal */
 	if (single_plane_incident > 0)	/* check input coverage */
 		single_plane_incident = (round(new_phi) == round(phi_in_deg));
 	else if (single_plane_incident < 0)
@@ -91,7 +104,10 @@ new_input_direction(double new_theta, double new_phi)
 int
 use_symmetry(FVECT vec)
 {
-	const double	phi = get_phi360(vec);
+	double	phi = get_phi360(vec);
+				/* because of -0. issue */
+	while (phi >= 360.) phi -= 360.;
+	while (phi < 0.) phi += 360.;
 
 	switch (inp_coverage) {
 	case INP_QUAD1|INP_QUAD2|INP_QUAD3|INP_QUAD4:
@@ -198,7 +214,7 @@ rotate_rbf(RBFNODE *rbf, const FVECT invec)
 	int			pos[2];
 	int			n;
 
-	for (n = ((-.01 > phi) | (phi > .01))*rbf->nrbf; n-- > 0; ) {
+	for (n = (cos(phi) < 1.-FTINY)*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);
@@ -257,24 +273,28 @@ rbf_volume(const RBFVAL *rbfp)
 	return(integ);
 }
 
-/* Evaluate RBF for DSF at the given normalized outgoing direction */
-double
-eval_rbfrep(const RBFNODE *rp, const FVECT outvec)
+/* Evaluate BSDF at the given normalized outgoing direction in color */
+SDError
+eval_rbfcol(SDValue *sv, 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;
+	double		usum = 0, vsum = 0;
 	const RBFVAL	*rbfp;
 	FVECT		odir;
 	double		rad2;
 	int		n;
+				/* assign default value */
+	sv->spec = c_dfcolor;
+	sv->cieY = bsdf_min;
 				/* check for wrong side */
-	if (outvec[2] > 0 ^ output_orient > 0)
-		return(.0);
-				/* use minimum if no information avail. */
-	if (rp == NULL)
-		return(minval);
+	if (outvec[2] > 0 ^ output_orient > 0) {
+		strcpy(SDerrorDetail, "Wrong-side scattering query");
+		return(SDEargument);
+	}
+	if (rp == NULL)		/* return minimum if no information avail. */
+		return(SDEnone);
 				/* optimization for fast lobe culling */
 	pos_from_vec(pos, outvec);
 				/* sum radial basis function */
@@ -282,18 +302,42 @@ eval_rbfrep(const RBFNODE *rp, const FVECT outvec)
 	for (n = rp->nrbf; n--; rbfp++) {
 		int	d2 = (pos[0]-rbfp->gx)*(pos[0]-rbfp->gx) +
 				(pos[1]-rbfp->gy)*(pos[1]-rbfp->gy);
+		double	val;
 		rad2 = R2ANG(rbfp->crad);
 		rad2 *= rad2;
 		if (d2 > rad2*rfact2)
 			continue;
 		ovec_from_pos(odir, rbfp->gx, rbfp->gy);
-		res += rbfp->peak * exp((DOT(odir,outvec) - 1.) / rad2);
+		val = rbfp->peak * exp((DOT(odir,outvec) - 1.) / rad2);
+		if (rbf_colorimetry == RBCtristimulus) {
+			usum += val * (rbfp->chroma & 0xff);
+			vsum += val * (rbfp->chroma>>8 & 0xff);
+		}
+		res += val;
 	}
-	if (res < minval)	/* never return less than minval */
-		return(minval);
-	return(res);
+	sv->cieY = res / COSF(outvec[2]);
+	if (sv->cieY < bsdf_min) {	/* never return less than bsdf_min */
+		sv->cieY = bsdf_min;
+	} else if (rbf_colorimetry == RBCtristimulus) {
+		C_CHROMA	cres = (int)(usum/res + frandom());
+		cres |= (int)(vsum/res + frandom()) << 8;
+		c_decodeChroma(&sv->spec, cres);
+	}
+	return(SDEnone);
 }
 
+/* Evaluate BSDF at the given normalized outgoing direction in Y */
+double
+eval_rbfrep(const RBFNODE *rp, const FVECT outvec)
+{
+	SDValue	sv;
+
+	if (eval_rbfcol(&sv, rp, outvec) == SDEnone)
+		return(sv.cieY);
+
+	return(0.0);
+}
+
 /* Insert a new directional scattering function in our global list */
 int
 insert_dsf(RBFNODE *newrbf)
@@ -304,8 +348,9 @@ insert_dsf(RBFNODE *newrbf)
 	for (rbf = dsf_list; rbf != NULL; rbf = rbf->next)
 		if (DOT(rbf->invec, newrbf->invec) >= 1.-FTINY) {
 			fprintf(stderr,
-				"%s: Duplicate incident measurement (ignored)\n",
-					progname);
+		"%s: Duplicate incident measurement ignored at (%.1f,%.1f)\n",
+					progname, get_theta180(newrbf->invec),
+					get_phi360(newrbf->invec));
 			free(newrbf);
 			return(-1);
 		}
@@ -393,6 +438,39 @@ get_triangles(RBFNODE *rbfv[2], const MIGRATION *mig)
 	return((rbfv[0] != NULL) + (rbfv[1] != NULL));
 }
 
+/* Return single-lobe specular RBF for the given incident direction */
+RBFNODE *
+def_rbf_spec(const FVECT invec)
+{
+	RBFNODE		*rbf;
+	FVECT		ovec;
+	int		pos[2];
+
+	if (input_orient > 0 ^ invec[2] > 0)	/* wrong side? */
+		return(NULL);
+	if ((bsdf_spec_val <= bsdf_min) | (bsdf_spec_rad <= 0))
+		return(NULL);			/* nothing set */
+	rbf = (RBFNODE *)malloc(sizeof(RBFNODE));
+	if (rbf == NULL)
+		return(NULL);
+	ovec[0] = -invec[0];
+	ovec[1] = -invec[1];
+	ovec[2] = invec[2]*(2*(input_orient==output_orient) - 1);
+	pos_from_vec(pos, ovec);
+	rbf->ord = 0;
+	rbf->next = NULL;
+	rbf->ejl = NULL;
+	VCOPY(rbf->invec, invec);
+	rbf->nrbf = 1;
+	rbf->rbfa[0].peak = bsdf_spec_val * COSF(ovec[2]);
+	rbf->rbfa[0].chroma = c_dfchroma;
+	rbf->rbfa[0].crad = ANG2R(bsdf_spec_rad);
+	rbf->rbfa[0].gx = pos[0];
+	rbf->rbfa[0].gy = pos[1];
+	rbf->vtotal = rbf_volume(rbf->rbfa);
+	return(rbf);
+}
+
 /* Advect and allocate new RBF along edge (internal call) */
 RBFNODE *
 e_advect_rbf(const MIGRATION *mig, const FVECT invec, int lobe_lim)
@@ -403,7 +481,7 @@ e_advect_rbf(const MIGRATION *mig, const FVECT invec, 
 	double		t, full_dist;
 						/* get relative position */
 	t = Acos(DOT(invec, mig->rbfv[0]->invec));
-	if (t < M_PI/grid_res) {		/* near first DSF */
+	if (t <= .001) {			/* near first DSF */
 		n = sizeof(RBFNODE) + sizeof(RBFVAL)*(mig->rbfv[0]->nrbf-1);
 		rbf = (RBFNODE *)malloc(n);
 		if (rbf == NULL)
@@ -413,7 +491,7 @@ e_advect_rbf(const MIGRATION *mig, const FVECT invec, 
 		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 */
+	if (t >= full_dist-.001) {		/* near second DSF */
 		n = sizeof(RBFNODE) + sizeof(RBFVAL)*(mig->rbfv[1]->nrbf-1);
 		rbf = (RBFNODE *)malloc(n);
 		if (rbf == NULL)
@@ -449,9 +527,11 @@ tryagain:
 	    const RBFVAL	*rbf0i = &mig->rbfv[0]->rbfa[i];
 	    const float		peak0 = rbf0i->peak;
 	    const double	rad0 = R2ANG(rbf0i->crad);
+	    C_COLOR		cc0;
 	    FVECT		v0;
 	    float		mv;
 	    ovec_from_pos(v0, rbf0i->gx, rbf0i->gy);
+	    c_decodeChroma(&cc0, rbf0i->chroma);
 	    for (j = 0; j < mtx_ncols(mig); j++)
 		if ((mv = mtx_coef(mig,i,j)) > cthresh) {
 			const RBFVAL	*rbf1j = &mig->rbfv[1]->rbfa[j];
@@ -462,6 +542,13 @@ tryagain:
 			rad2 = rad0*rad0*(1.-t) + rad2*rad2*t;
 			rbf->rbfa[n].peak = peak0 * mv * rbf->vtotal *
 						rad0*rad0/rad2;
+			if (rbf_colorimetry == RBCtristimulus) {
+				C_COLOR	cres;
+				c_decodeChroma(&cres, rbf1j->chroma);
+				c_cmix(&cres, 1.-t, &cc0, t, &cres);
+				rbf->rbfa[n].chroma = c_encodeChroma(&cres);
+			} else
+				rbf->rbfa[n].chroma = c_dfchroma;
 			rbf->rbfa[n].crad = ANG2R(sqrt(rad2));
 			ovec_from_pos(v, rbf1j->gx, rbf1j->gy);
 			geodesic(v, v0, v, t, GEOD_REL);
@@ -498,7 +585,12 @@ clear_bsdf_rep(void)
 	inp_coverage = 0;
 	single_plane_incident = -1;
 	input_orient = output_orient = 0;
+	rbf_colorimetry = RBCunknown;
 	grid_res = GRIDRES;
+	memset(bsdf_hist, 0, sizeof(bsdf_hist));
+	bsdf_min = 0;
+	bsdf_spec_val = 0;
+	bsdf_spec_rad = 0;
 }
 
 /* Write our BSDF mesh interpolant out to the given binary stream */
@@ -515,10 +607,14 @@ save_bsdf_rep(FILE *ofp)
 		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, "COLORIMETRY=%s\n", RBCident[rbf_colorimetry]);
 	fprintf(ofp, "GRIDRES=%d\n", grid_res);
 	fprintf(ofp, "BSDFMIN=%g\n", bsdf_min);
+	if ((bsdf_spec_val > bsdf_min) & (bsdf_spec_rad > 0))
+		fprintf(ofp, "BSDFSPEC= %f %f\n", bsdf_spec_val, bsdf_spec_rad);
 	fputformat(BSDFREP_FMT, ofp);
 	fputc('\n', ofp);
+	putint(BSDFREP_MAGIC, 2, ofp);
 					/* write each DSF */
 	for (rbf = dsf_list; rbf != NULL; rbf = rbf->next) {
 		putint(rbf->ord, 4, ofp);
@@ -529,9 +625,10 @@ save_bsdf_rep(FILE *ofp)
 		putint(rbf->nrbf, 4, ofp);
 		for (i = 0; i < rbf->nrbf; i++) {
 			putflt(rbf->rbfa[i].peak, ofp);
+			putint(rbf->rbfa[i].chroma, 2, ofp);
 			putint(rbf->rbfa[i].crad, 2, ofp);
-			putint(rbf->rbfa[i].gx, 1, ofp);
-			putint(rbf->rbfa[i].gy, 1, ofp);
+			putint(rbf->rbfa[i].gx, 2, ofp);
+			putint(rbf->rbfa[i].gy, 2, ofp);
 		}
 	}
 	putint(-1, 4, ofp);		/* terminator */
@@ -567,35 +664,57 @@ save_bsdf_rep(FILE *ofp)
 static int
 headline(char *s, void *p)
 {
-	char	fmt[32];
+	char	fmt[MAXFMTLEN];
+	int	i;
 
+	if (isheadid(s))
+		return(0);
 	if (!strncmp(s, "NAME=", 5)) {
 		strcpy(bsdf_name, s+5);
 		bsdf_name[strlen(bsdf_name)-1] = '\0';
+		return(1);
 	}
 	if (!strncmp(s, "MANUFACT=", 9)) {
 		strcpy(bsdf_manuf, s+9);
 		bsdf_manuf[strlen(bsdf_manuf)-1] = '\0';
+		return(1);
 	}
 	if (!strncmp(s, "SYMMETRY=", 9)) {
 		inp_coverage = atoi(s+9);
 		single_plane_incident = !inp_coverage;
-		return(0);
+		return(1);
 	}
 	if (!strncmp(s, "IO_SIDES=", 9)) {
 		sscanf(s+9, "%d %d", &input_orient, &output_orient);
-		return(0);
+		return(1);
 	}
+	if (!strncmp(s, "COLORIMETRY=", 12)) {
+		fmt[0] = '\0';
+		sscanf(s+12, "%s", fmt);
+		for (i = RBCunknown; i >= 0; i--)
+			if (!strcmp(fmt, RBCident[i]))
+				break;
+		if (i < 0)
+			return(-1);
+		rbf_colorimetry = i;
+		return(1);
+	}
 	if (!strncmp(s, "GRIDRES=", 8)) {
 		sscanf(s+8, "%d", &grid_res);
-		return(0);
+		return(1);
 	}
 	if (!strncmp(s, "BSDFMIN=", 8)) {
 		sscanf(s+8, "%lf", &bsdf_min);
-		return(0);
+		return(1);
 	}
-	if (formatval(fmt, s) && strcmp(fmt, BSDFREP_FMT))
-		return(-1);
+	if (!strncmp(s, "BSDFSPEC=", 9)) {
+		sscanf(s+9, "%lf %lf", &bsdf_spec_val, &bsdf_spec_rad);
+		return(1);
+	}
+	if (formatval(fmt, s))
+		return (strcmp(fmt, BSDFREP_FMT) ? -1 : 0);
+	if (sir_headshare != NULL)
+		return ((*sir_headshare)(s));
 	return(0);
 }
 
@@ -611,11 +730,17 @@ load_bsdf_rep(FILE *ifp)
 	if (ifp == NULL)
 		return(0);
 	if (getheader(ifp, headline, NULL) < 0 || (single_plane_incident < 0) |
-			!input_orient | !output_orient) {
+			!input_orient | !output_orient |
+			(grid_res < 16) | (grid_res > 0xffff)) {
 		fprintf(stderr, "%s: missing/bad format for BSDF interpolant\n",
 				progname);
 		return(0);
 	}
+	if (getint(2, ifp) != BSDFREP_MAGIC) {
+		fprintf(stderr, "%s: bad magic number for BSDF interpolant\n",
+				progname);
+		return(0);
+	}
 	memset(&rbfh, 0, sizeof(rbfh));	/* read each DSF */
 	while ((rbfh.ord = getint(4, ifp)) >= 0) {
 		RBFNODE		*newrbf;
@@ -636,9 +761,10 @@ load_bsdf_rep(FILE *ifp)
 		*newrbf = rbfh;
 		for (i = 0; i < rbfh.nrbf; i++) {
 			newrbf->rbfa[i].peak = getflt(ifp);
+			newrbf->rbfa[i].chroma = getint(2, ifp) & 0xffff;
 			newrbf->rbfa[i].crad = getint(2, ifp) & 0xffff;
-			newrbf->rbfa[i].gx = getint(1, ifp) & 0xff;
-			newrbf->rbfa[i].gy = getint(1, ifp) & 0xff;
+			newrbf->rbfa[i].gx = getint(2, ifp) & 0xffff;
+			newrbf->rbfa[i].gy = getint(2, ifp) & 0xffff;
 		}
 		if (feof(ifp))
 			goto badEOF;