--- ray/src/gen/mkillum2.c	2004/09/19 08:42:22	2.17
+++ ray/src/gen/mkillum2.c	2009/07/02 04:26:41	2.32
@@ -1,5 +1,5 @@
 #ifndef lint
-static const char	RCSid[] = "$Id: mkillum2.c,v 2.17 2004/09/19 08:42:22 greg Exp $";
+static const char	RCSid[] = "$Id: mkillum2.c,v 2.32 2009/07/02 04:26:41 greg Exp $";
 #endif
 /*
  * Routines to do the actual calculation for mkillum
@@ -10,31 +10,268 @@ static const char	RCSid[] = "$Id: mkillum2.c,v 2.17 20
 #include  "mkillum.h"
 #include  "face.h"
 #include  "cone.h"
-#include  "random.h"
-#include  "selcall.h"
+#include  "source.h"
 
+#ifndef NBSDFSAMPS
+#define NBSDFSAMPS	256		/* BSDF resampling count */
+#endif
 
-static void mkaxes(FVECT u, FVECT v, FVECT n);
-static void rounddir(FVECT dv, double alt, double azi);
-static void flatdir(FVECT dv, double alt, double azi);
+COLORV *	distarr = NULL;		/* distribution array */
+int		distsiz = 0;
+COLORV *	direct_discount = NULL;	/* amount to take off direct */
 
 
+void
+newdist(			/* allocate & clear distribution array */
+	int siz
+)
+{
+	if (siz <= 0) {
+		if (distsiz > 0)
+			free((void *)distarr);
+		distarr = NULL;
+		distsiz = 0;
+		return;
+	}
+	if (distsiz < siz) {
+		if (distsiz > 0)
+			free((void *)distarr);
+		distarr = (COLORV *)malloc(sizeof(COLOR)*siz);
+		if (distarr == NULL)
+			error(SYSTEM, "out of memory in newdist");
+		distsiz = siz;
+	}
+	memset(distarr, '\0', sizeof(COLOR)*siz);
+}
+
+
 static void
-rayclean(			/* finish all pending rays */
-	struct rtproc *rt0
+new_discount()			/* allocate space for direct contrib. record */
+{
+	if (distsiz <= 0)
+		return;
+	direct_discount = (COLORV *)calloc(distsiz, sizeof(COLOR));
+	if (direct_discount == NULL)
+		error(SYSTEM, "out of memory in new_discount");
+}
+
+
+static void
+done_discount()			/* clear off direct contrib. record */
+{
+	if (direct_discount == NULL)
+		return;
+	free((void *)direct_discount);
+	direct_discount = NULL;
+}
+
+
+int
+process_ray(			/* process a ray result or report error */
+	RAY *r,
+	int rv
 )
 {
-	rayflush(rt0, 1);
-	while (raywait(rt0) != NULL)
+	COLORV	*colp;
+
+	if (rv == 0)			/* no result ready */
+		return(0);
+	if (rv < 0)
+		error(USER, "ray tracing process died");
+	if (r->rno >= distsiz)
+		error(INTERNAL, "bad returned index in process_ray");
+	multcolor(r->rcol, r->rcoef);	/* in case it's a source ray */
+	colp = &distarr[r->rno * 3];
+	addcolor(colp, r->rcol);
+	if (r->rsrc >= 0 &&		/* remember source contrib. */
+			direct_discount != NULL) {
+		colp = &direct_discount[r->rno * 3];
+		addcolor(colp, r->rcol);
+	}
+	return(1);
+}
+
+
+void
+raysamp(			/* queue a ray sample */
+	int  ndx,
+	FVECT  org,
+	FVECT  dir
+)
+{
+	RAY	myRay;
+	int	rv;
+
+	if ((ndx < 0) | (ndx >= distsiz))
+		error(INTERNAL, "bad index in raysamp");
+	VCOPY(myRay.rorg, org);
+	VCOPY(myRay.rdir, dir);
+	myRay.rmax = .0;
+	rayorigin(&myRay, PRIMARY, NULL, NULL);
+	myRay.rno = ndx;
+					/* queue ray, check result */
+	process_ray(&myRay, ray_pqueue(&myRay));
+}
+
+
+void
+srcsamps(			/* sample sources from this surface position */
+	struct illum_args *il,
+	FVECT org,
+	FVECT nrm,
+	MAT4 ixfm
+)
+{
+	int  nalt, nazi;
+	SRCINDEX  si;
+	RAY  sr;
+	FVECT	v;
+	double  d;
+	int  i, j;
+						/* get sampling density */
+	if (il->sampdens <= 0) {
+		nalt = nazi = 1;
+	} else {
+		i = PI * il->sampdens;
+		nalt = sqrt(i/PI) + .5;
+		nazi = PI*nalt + .5;
+	}
+	initsrcindex(&si);			/* loop over (sub)sources */
+	for ( ; ; ) {
+		VCOPY(sr.rorg, org);		/* pick side to shoot from */
+		if (il->sd != NULL) {
+			int  sn = si.sn;
+			if (si.sp+1 >= si.np) ++sn;
+			if (sn >= nsources) break;
+			if (source[sn].sflags & SDISTANT)
+				d = DOT(source[sn].sloc, nrm);
+			else {
+				VSUB(v, source[sn].sloc, org);
+				d = DOT(v, nrm);
+			}
+		} else
+			d = 1.0;		/* only transmission */
+		if (d < 0.0)
+			d = -1.0001*il->thick - 5.*FTINY;
+		else
+			d = 5.*FTINY;
+		for (i = 3; i--; )
+			sr.rorg[i] += d*nrm[i];
+		samplendx++;			/* increment sample counter */
+		if (!srcray(&sr, NULL, &si))
+			break;			/* end of sources */
+						/* index direction */
+		if (ixfm != NULL)
+			multv3(v, sr.rdir, ixfm);
+		else
+			VCOPY(v, sr.rdir);
+		if (il->sd != NULL) {
+			i = getBSDF_incndx(il->sd, v);
+			if (i < 0)
+				continue;	/* must not be important */
+			sr.rno = i;
+			d = 1.0/getBSDF_incohm(il->sd, i);
+		} else {
+			if (v[2] >= -FTINY)
+				continue;	/* only sample transmission */
+			v[0] = -v[0]; v[1] = -v[1]; v[2] = -v[2];
+			sr.rno = flatindex(v, nalt, nazi);
+			d = nalt*nazi*(1./PI) * v[2];
+		}
+		d *= si.dom;			/* solid angle correction */
+		scalecolor(sr.rcoef, d);
+		process_ray(&sr, ray_pqueue(&sr));
+	}
+}
+
+
+void
+rayclean()			/* finish all pending rays */
+{
+	RAY	myRay;
+
+	while (process_ray(&myRay, ray_presult(&myRay, 0)))
 		;
 }
 
 
-int /* XXX type conflict with otypes.h */
-o_default(	/* default illum action */
+static void
+mkaxes(			/* compute u and v to go with n */
+	FVECT  u,
+	FVECT  v,
+	FVECT  n
+)
+{
+	register int  i;
+
+	v[0] = v[1] = v[2] = 0.0;
+	for (i = 0; i < 3; i++)
+		if (n[i] < 0.6 && n[i] > -0.6)
+			break;
+	v[i] = 1.0;
+	fcross(u, v, n);
+	normalize(u);
+	fcross(v, n, u);
+}
+
+
+static void
+rounddir(		/* compute uniform spherical direction */
+	register FVECT  dv,
+	double  alt,
+	double  azi
+)
+{
+	double  d1, d2;
+
+	dv[2] = 1. - 2.*alt;
+	d1 = sqrt(1. - dv[2]*dv[2]);
+	d2 = 2.*PI * azi;
+	dv[0] = d1*cos(d2);
+	dv[1] = d1*sin(d2);
+}
+
+
+void
+flatdir(		/* compute uniform hemispherical direction */
+	FVECT  dv,
+	double  alt,
+	double  azi
+)
+{
+	double  d1, d2;
+
+	d1 = sqrt(alt);
+	d2 = 2.*PI * azi;
+	dv[0] = d1*cos(d2);
+	dv[1] = d1*sin(d2);
+	dv[2] = sqrt(1. - alt);
+}
+
+int
+flatindex(		/* compute index for hemispherical direction */
+	FVECT	dv,
+	int	nalt,
+	int	nazi
+)
+{
+	double	d;
+	int	i, j;
+	
+	d = 1.0 - dv[2]*dv[2];
+	i = d*nalt;
+	d = atan2(dv[1], dv[0]) * (0.5/PI);
+	if (d < 0.0) d += 1.0;
+	j = d*nazi + 0.5;
+	if (j >= nazi) j = 0;
+	return(i*nazi + j);
+}
+
+
+int
+my_default(	/* default illum action */
 	OBJREC  *ob,
 	struct illum_args  *il,
-	struct rtproc  *rt0,
 	char  *nm
 )
 {
@@ -47,43 +284,49 @@ o_default(	/* default illum action */
 
 
 int
-o_face(		/* make an illum face */
+my_face(		/* make an illum face */
 	OBJREC  *ob,
 	struct illum_args  *il,
-	struct rtproc  *rt0,
 	char  *nm
 )
 {
-#define MAXMISS		(5*n*il->nsamps)
-	int  dim[3];
-	int  n, nalt, nazi, h;
-	float  *distarr;
+	int  dim[2];
+	int  n, nalt, nazi, alti;
 	double  sp[2], r1, r2;
+	int  h;
 	FVECT  dn, org, dir;
 	FVECT  u, v;
 	double  ur[2], vr[2];
-	int  nmisses;
-	register FACE  *fa;
-	register int  i, j;
+	MAT4  xfm;
+	int  nallow;
+	FACE  *fa;
+	int  i, j;
 				/* get/check arguments */
 	fa = getface(ob);
 	if (fa->area == 0.0) {
 		freeface(ob);
-		return(o_default(ob, il, rt0, nm));
+		return(my_default(ob, il, nm));
 	}
 				/* set up sampling */
-	if (il->sampdens <= 0)
-		nalt = nazi = 1;
-	else {
-		n = PI * il->sampdens;
-		nalt = sqrt(n/PI) + .5;
-		nazi = PI*nalt + .5;
+	if (il->sd != NULL) {
+		if (!getBSDF_xfm(xfm, fa->norm, il->udir)) {
+			objerror(ob, WARNING, "illegal up direction");
+			freeface(ob);
+			return(my_default(ob, il, nm));
+		}
+		n = il->sd->ninc;
+	} else {
+		if (il->sampdens <= 0) {
+			nalt = nazi = 1;	/* diffuse assumption */
+		} else {
+			n = PI * il->sampdens;
+			nalt = sqrt(n/PI) + .5;
+			nazi = PI*nalt + .5;
+		}
+		n = nazi*nalt;
 	}
-	n = nalt*nazi;
-	distarr = (float *)calloc(n, 3*sizeof(float));
-	if (distarr == NULL)
-		error(SYSTEM, "out of memory in o_face");
-				/* take first edge longer than sqrt(area) */
+	newdist(n);
+				/* take first edge >= sqrt(area) */
 	for (j = fa->nv-1, i = 0; i < fa->nv; j = i++) {
 		u[0] = VERTEX(fa,i)[0] - VERTEX(fa,j)[0];
 		u[1] = VERTEX(fa,i)[1] - VERTEX(fa,j)[1];
@@ -110,42 +353,101 @@ o_face(		/* make an illum face */
 	}
 	dim[0] = random();
 				/* sample polygon */
-	nmisses = 0;
-	for (dim[1] = 0; dim[1] < nalt; dim[1]++)
-	    for (dim[2] = 0; dim[2] < nazi; dim[2]++)
+	nallow = 5*n*il->nsamps;
+	for (dim[1] = 0; dim[1] < n; dim[1]++)
 		for (i = 0; i < il->nsamps; i++) {
-					/* random direction */
-		    h = ilhash(dim, 3) + i;
-		    multisamp(sp, 2, urand(h));
-		    r1 = (dim[1] + sp[0])/nalt;
-		    r2 = (dim[2] + sp[1] - .5)/nazi;
-		    flatdir(dn, r1, r2);
-		    for (j = 0; j < 3; j++)
-			dir[j] = -dn[0]*u[j] - dn[1]*v[j] - dn[2]*fa->norm[j];
-					/* random location */
+					/* randomize direction */
+		    h = ilhash(dim, 2) + i;
+		    if (il->sd != NULL) {
+			r_BSDF_incvec(dir, il->sd, dim[1], urand(h), xfm);
+		    } else {
+			multisamp(sp, 2, urand(h));
+			alti = dim[1]/nazi;
+			r1 = (alti + sp[0])/nalt;
+			r2 = (dim[1] - alti*nazi + sp[1] - .5)/nazi;
+			flatdir(dn, r1, r2);
+			for (j = 0; j < 3; j++)
+			    dir[j] = -dn[0]*u[j] - dn[1]*v[j] -
+						dn[2]*fa->norm[j];
+		    }
+					/* randomize location */
 		    do {
-			multisamp(sp, 2, urand(h+4862+nmisses));
+			multisamp(sp, 2, urand(h+4862+nallow));
 			r1 = ur[0] + (ur[1]-ur[0]) * sp[0];
 			r2 = vr[0] + (vr[1]-vr[0]) * sp[1];
 			for (j = 0; j < 3; j++)
 			    org[j] = r1*u[j] + r2*v[j]
 					+ fa->offset*fa->norm[j];
-		    } while (!inface(org, fa) && nmisses++ < MAXMISS);
-		    if (nmisses > MAXMISS) {
+		    } while (!inface(org, fa) && nallow-- > 0);
+		    if (nallow < 0) {
 			objerror(ob, WARNING, "bad aspect");
-			rayclean(rt0);
+			rayclean();
 			freeface(ob);
-			free((void *)distarr);
-			return(o_default(ob, il, rt0, nm));
+			return(my_default(ob, il, nm));
 		    }
+		    if (il->sd != NULL && DOT(dir, fa->norm) < -FTINY)
+			r1 = -1.0001*il->thick - 5.*FTINY;
+		    else
+			r1 = 5.*FTINY;
 		    for (j = 0; j < 3; j++)
-			org[j] += .001*fa->norm[j];
+			org[j] += r1*fa->norm[j];
 					/* send sample */
-		    raysamp(distarr+3*(dim[1]*nazi+dim[2]), org, dir, rt0);
+		    raysamp(dim[1], org, dir);
 		}
-	rayclean(rt0);
+				/* add in direct component? */
+	if (!directvis && (il->flags & IL_LIGHT || il->sd != NULL)) {
+		MAT4	ixfm;
+		if (il->sd == NULL) {
+			for (i = 3; i--; ) {
+				ixfm[i][0] = u[i];
+				ixfm[i][1] = v[i];
+				ixfm[i][2] = fa->norm[i];
+				ixfm[i][3] = 0.;
+			}
+			ixfm[3][0] = ixfm[3][1] = ixfm[3][2] = 0.;
+			ixfm[3][3] = 1.;
+		} else {
+			if (!invmat4(ixfm, xfm))
+				objerror(ob, INTERNAL,
+					"cannot invert BSDF transform");
+			if (!(il->flags & IL_LIGHT))
+				new_discount();
+		}
+		dim[0] = random();
+		nallow = 10*il->nsamps;
+		for (i = 0; i < il->nsamps; i++) {
+					/* randomize location */
+		    h = dim[0] + samplendx++;
+		    do {
+			multisamp(sp, 2, urand(h+nallow));
+			r1 = ur[0] + (ur[1]-ur[0]) * sp[0];
+			r2 = vr[0] + (vr[1]-vr[0]) * sp[1];
+			for (j = 0; j < 3; j++)
+			    org[j] = r1*u[j] + r2*v[j]
+					+ fa->offset*fa->norm[j];
+		    } while (!inface(org, fa) && nallow-- > 0);
+		    if (nallow < 0) {
+			objerror(ob, WARNING, "bad aspect");
+			rayclean();
+			freeface(ob);
+			return(my_default(ob, il, nm));
+		    }
+					/* sample source rays */
+		    srcsamps(il, org, fa->norm, ixfm);
+		}
+	}
+				/* wait for all rays to finish */
+	rayclean();
+	if (il->sd != NULL) {	/* run distribution through BSDF */
+		nalt = sqrt(il->sd->nout/PI) + .5;
+		nazi = PI*nalt + .5;
+		redistribute(il->sd, nalt, nazi, u, v, fa->norm, xfm);
+		done_discount();
+		if (!il->sampdens)
+			il->sampdens = nalt*nazi/PI + .999;
+	}
 				/* write out the face and its distribution */
-	if (average(il, distarr, nalt*nazi)) {
+	if (average(il, distarr, n)) {
 		if (il->sampdens > 0)
 			flatout(il, distarr, nalt, nazi, u, v, fa->norm);
 		illumout(il, ob);
@@ -153,23 +455,19 @@ o_face(		/* make an illum face */
 		printobj(il->altmat, ob);
 				/* clean up */
 	freeface(ob);
-	free((void *)distarr);
 	return(0);
-#undef MAXMISS
 }
 
 
 int
-o_sphere(	/* make an illum sphere */
+my_sphere(	/* make an illum sphere */
 	register OBJREC  *ob,
 	struct illum_args  *il,
-	struct rtproc  *rt0,
 	char  *nm
 )
 {
 	int  dim[3];
 	int  n, nalt, nazi;
-	float  *distarr;
 	double  sp[4], r1, r2, r3;
 	FVECT  org, dir;
 	FVECT  u, v;
@@ -185,10 +483,10 @@ o_sphere(	/* make an illum sphere */
 		nalt = sqrt(2./PI*n) + .5;
 		nazi = PI/2.*nalt + .5;
 	}
+	if (il->sd != NULL)
+		objerror(ob, WARNING, "BSDF ignored");
 	n = nalt*nazi;
-	distarr = (float *)calloc(n, 3*sizeof(float));
-	if (distarr == NULL)
-		error(SYSTEM, "out of memory in o_sphere");
+	newdist(n);
 	dim[0] = random();
 				/* sample sphere */
 	for (dim[1] = 0; dim[1] < nalt; dim[1]++)
@@ -213,11 +511,12 @@ o_sphere(	/* make an illum sphere */
 			dir[j] = -dir[j];
 		    }
 					/* send sample */
-		    raysamp(distarr+3*(dim[1]*nazi+dim[2]), org, dir, rt0);
+		    raysamp(dim[1]*nazi+dim[2], org, dir);
 		}
-	rayclean(rt0);
+				/* wait for all rays to finish */
+	rayclean();
 				/* write out the sphere and its distribution */
-	if (average(il, distarr, nalt*nazi)) {
+	if (average(il, distarr, n)) {
 		if (il->sampdens > 0)
 			roundout(il, distarr, nalt, nazi);
 		else
@@ -226,71 +525,130 @@ o_sphere(	/* make an illum sphere */
 	} else
 		printobj(il->altmat, ob);
 				/* clean up */
-	free((void *)distarr);
 	return(1);
 }
 
 
 int
-o_ring(		/* make an illum ring */
+my_ring(		/* make an illum ring */
 	OBJREC  *ob,
 	struct illum_args  *il,
-	struct rtproc  *rt0,
 	char  *nm
 )
 {
-	int  dim[3];
-	int  n, nalt, nazi;
-	float  *distarr;
-	double  sp[4], r1, r2, r3;
+	int  dim[2];
+	int  n, nalt, nazi, alti;
+	double  sp[2], r1, r2, r3;
+	int  h;
 	FVECT  dn, org, dir;
 	FVECT  u, v;
-	register CONE  *co;
-	register int  i, j;
+	MAT4  xfm;
+	CONE  *co;
+	int  i, j;
 				/* get/check arguments */
 	co = getcone(ob, 0);
 				/* set up sampling */
-	if (il->sampdens <= 0)
-		nalt = nazi = 1;
-	else {
-		n = PI * il->sampdens;
-		nalt = sqrt(n/PI) + .5;
-		nazi = PI*nalt + .5;
+	if (il->sd != NULL) {
+		if (!getBSDF_xfm(xfm, co->ad, il->udir)) {
+			objerror(ob, WARNING, "illegal up direction");
+			freecone(ob);
+			return(my_default(ob, il, nm));
+		}
+		n = il->sd->ninc;
+	} else {
+		if (il->sampdens <= 0) {
+			nalt = nazi = 1;	/* diffuse assumption */
+		} else {
+			n = PI * il->sampdens;
+			nalt = sqrt(n/PI) + .5;
+			nazi = PI*nalt + .5;
+		}
+		n = nazi*nalt;
 	}
-	n = nalt*nazi;
-	distarr = (float *)calloc(n, 3*sizeof(float));
-	if (distarr == NULL)
-		error(SYSTEM, "out of memory in o_ring");
+	newdist(n);
 	mkaxes(u, v, co->ad);
 	dim[0] = random();
 				/* sample disk */
-	for (dim[1] = 0; dim[1] < nalt; dim[1]++)
-	    for (dim[2] = 0; dim[2] < nazi; dim[2]++)
+	for (dim[1] = 0; dim[1] < n; dim[1]++)
 		for (i = 0; i < il->nsamps; i++) {
 					/* next sample point */
-		    multisamp(sp, 4, urand(ilhash(dim,3)+i));
-					/* random direction */
-		    r1 = (dim[1] + sp[0])/nalt;
-		    r2 = (dim[2] + sp[1] - .5)/nazi;
-		    flatdir(dn, r1, r2);
-		    for (j = 0; j < 3; j++)
-			dir[j] = -dn[0]*u[j] - dn[1]*v[j] - dn[2]*co->ad[j];
-					/* random location */
+		    h = ilhash(dim,2) + i;
+					/* randomize direction */
+		    if (il->sd != NULL) {
+			r_BSDF_incvec(dir, il->sd, dim[1], urand(h), xfm);
+		    } else {
+			multisamp(sp, 2, urand(h));
+			alti = dim[1]/nazi;
+			r1 = (alti + sp[0])/nalt;
+			r2 = (dim[1] - alti*nazi + sp[1] - .5)/nazi;
+			flatdir(dn, r1, r2);
+			for (j = 0; j < 3; j++)
+				dir[j] = -dn[0]*u[j] - dn[1]*v[j] - dn[2]*co->ad[j];
+		    }
+					/* randomize location */
+		    multisamp(sp, 2, urand(h+8371));
 		    r3 = sqrt(CO_R0(co)*CO_R0(co) +
-			    sp[2]*(CO_R1(co)*CO_R1(co) - CO_R0(co)*CO_R0(co)));
-		    r2 = 2.*PI*sp[3];
+			    sp[0]*(CO_R1(co)*CO_R1(co) - CO_R0(co)*CO_R0(co)));
+		    r2 = 2.*PI*sp[1];
 		    r1 = r3*cos(r2);
 		    r2 = r3*sin(r2);
+		    if (il->sd != NULL && DOT(dir, co->ad) < -FTINY)
+			r3 = -1.0001*il->thick - 5.*FTINY;
+		    else
+			r3 = 5.*FTINY;
 		    for (j = 0; j < 3; j++)
 			org[j] = CO_P0(co)[j] + r1*u[j] + r2*v[j] +
-					.001*co->ad[j];
-
+						r3*co->ad[j];
 					/* send sample */
-		    raysamp(distarr+3*(dim[1]*nazi+dim[2]), org, dir, rt0);
+		    raysamp(dim[1], org, dir);
 		}
-	rayclean(rt0);
+				/* add in direct component? */
+	if (!directvis && (il->flags & IL_LIGHT || il->sd != NULL)) {
+		MAT4	ixfm;
+		if (il->sd == NULL) {
+			for (i = 3; i--; ) {
+				ixfm[i][0] = u[i];
+				ixfm[i][1] = v[i];
+				ixfm[i][2] = co->ad[i];
+				ixfm[i][3] = 0.;
+			}
+			ixfm[3][0] = ixfm[3][1] = ixfm[3][2] = 0.;
+			ixfm[3][3] = 1.;
+		} else {
+			if (!invmat4(ixfm, xfm))
+				objerror(ob, INTERNAL,
+					"cannot invert BSDF transform");
+			if (!(il->flags & IL_LIGHT))
+				new_discount();
+		}
+		dim[0] = random();
+		for (i = 0; i < il->nsamps; i++) {
+					/* randomize location */
+		    h = dim[0] + samplendx++;
+		    multisamp(sp, 2, urand(h));
+		    r3 = sqrt(CO_R0(co)*CO_R0(co) +
+			    sp[0]*(CO_R1(co)*CO_R1(co) - CO_R0(co)*CO_R0(co)));
+		    r2 = 2.*PI*sp[1];
+		    r1 = r3*cos(r2);
+		    r2 = r3*sin(r2);
+		    for (j = 0; j < 3; j++)
+			org[j] = CO_P0(co)[j] + r1*u[j] + r2*v[j];
+					/* sample source rays */
+		    srcsamps(il, org, co->ad, ixfm);
+		}
+	}
+				/* wait for all rays to finish */
+	rayclean();
+	if (il->sd != NULL) {	/* run distribution through BSDF */
+		nalt = sqrt(il->sd->nout/PI) + .5;
+		nazi = PI*nalt + .5;
+		redistribute(il->sd, nalt, nazi, u, v, co->ad, xfm);
+		done_discount();
+		if (!il->sampdens)
+			il->sampdens = nalt*nazi/PI + .999;
+	}
 				/* write out the ring and its distribution */
-	if (average(il, distarr, nalt*nazi)) {
+	if (average(il, distarr, n)) {
 		if (il->sampdens > 0)
 			flatout(il, distarr, nalt, nazi, u, v, co->ad);
 		illumout(il, ob);
@@ -298,160 +656,107 @@ o_ring(		/* make an illum ring */
 		printobj(il->altmat, ob);
 				/* clean up */
 	freecone(ob);
-	free((void *)distarr);
 	return(1);
 }
 
 
 void
-raysamp(	/* queue a ray sample */
-	float  res[3],
-	FVECT  org,
-	FVECT  dir,
-	struct rtproc *rt0
+redistribute(		/* pass distarr ray sums through BSDF */
+	struct BSDF_data *b,
+	int nalt,
+	int nazi,
+	FVECT u,
+	FVECT v,
+	FVECT w,
+	MAT4 xm
 )
 {
-	register struct rtproc  *rt;
-	register float  *fp;
-
-	for (rt = rt0; rt != NULL; rt = rt->next)
-		if (rt->nrays < rt->bsiz && rt->dest[rt->nrays] == NULL)
-			break;
-	if (rt == NULL)		/* need to free up buffer? */
-		rt = raywait(rt0);
-	if (rt == NULL)
-		error(SYSTEM, "raywait() returned NULL in raysamp()");
-	fp = rt->buf + 6*rt->nrays;
-	*fp++ = org[0]; *fp++ = org[1]; *fp++ = org[2];
-	*fp++ = dir[0]; *fp++ = dir[1]; *fp = dir[2];
-	rt->dest[rt->nrays++] = res;
-	if (rt->nrays == rt->bsiz)
-		rayflush(rt, 0);
-}
-
-
-void
-rayflush(			/* flush queued rays to rtrace */
-	register struct rtproc  *rt,
-	int  doall
-)
-{
-	int	nw;
-
-	do {
-		if (rt->nrays <= 0)
-			continue;
-		memset(rt->buf+6*rt->nrays, 0, 6*sizeof(float));
-		nw = 6*sizeof(float)*(rt->nrays+1);
-		errno = 0;
-		if (writebuf(rt->pd.w, (char *)rt->buf, nw) < nw)
-			error(SYSTEM, "error writing to rtrace process");
-		rt->nrays = 0;		/* flag buffer as flushed */
-	} while (doall && (rt = rt->next) != NULL);
-}
-
-
-struct rtproc *
-raywait(			/* retrieve rtrace results */
-	struct rtproc *rt0
-)
-{
-	fd_set	readset, errset;
-	int	nr;
-	struct rtproc	*rtfree;
-	register struct rtproc	*rt;
-	register int	n;
-				/* prepare select call */
-	FD_ZERO(&readset); FD_ZERO(&errset); n = 0;
-	nr = 0;
-	for (rt = rt0; rt != NULL; rt = rt->next) {
-		if (rt->nrays == 0 && rt->dest[0] != NULL) {
-			FD_SET(rt->pd.r, &readset);
-			++nr;
-		}
-		FD_SET(rt->pd.r, &errset);
-		if (rt->pd.r >= n)
-			n = rt->pd.r + 1;
+	int	nout = 0;
+	MAT4	mymat, inmat;
+	COLORV	*idist;
+	COLORV	*cp;
+	FVECT	dv;
+	double	wt;
+	int	i, j, k, c, o;
+	COLOR	col, cinc;
+					/* copy incoming distribution */
+	if (b->ninc > distsiz)
+		error(INTERNAL, "error 1 in redistribute");
+	idist = (COLORV *)malloc(sizeof(COLOR)*b->ninc);
+	if (idist == NULL)
+		error(SYSTEM, "out of memory in redistribute");
+	memcpy(idist, distarr, sizeof(COLOR)*b->ninc);
+					/* compose direction transform */
+	for (i = 3; i--; ) {
+		mymat[i][0] = u[i];
+		mymat[i][1] = v[i];
+		mymat[i][2] = w[i];
+		mymat[i][3] = 0.;
 	}
-	if (!nr)		/* no rays pending */
-		return(NULL);
-	if (nr > 1) {		/* call select for multiple processes */
-		errno = 0;
-		if (select(n, &readset, NULL, &errset, NULL) < 0)
-			error(SYSTEM, "select call error in raywait()");
-	} else
-		FD_ZERO(&errset);
-	rtfree = NULL;		/* read from ready process(es) */
-	for (rt = rt0; rt != NULL; rt = rt->next) {
-		if (!FD_ISSET(rt->pd.r, &readset) &&
-				!FD_ISSET(rt->pd.r, &errset))
-			continue;
-		for (n = 0; n < rt->bsiz && rt->dest[n] != NULL; n++)
-			;
-		nr = 3*sizeof(float)*(n+1);
-		if (readbuf(rt->pd.r, (char *)rt->buf, nr) < nr)
-			error(USER, "rtrace process died");
-		while (n-- > 0) {
-			rt->dest[n][0] += rt->buf[3*n];
-			rt->dest[n][1] += rt->buf[3*n+1];
-			rt->dest[n][2] += rt->buf[3*n+2];
-			rt->dest[n] = NULL;
+	mymat[3][0] = mymat[3][1] = mymat[3][2] = 0.;
+	mymat[3][3] = 1.;
+	if (xm != NULL)
+		multmat4(mymat, xm, mymat);
+	for (i = 3; i--; ) {		/* make sure it's normalized */
+		wt = 1./sqrt(	mymat[0][i]*mymat[0][i] +
+				mymat[1][i]*mymat[1][i] +
+				mymat[2][i]*mymat[2][i]	);
+		for (j = 3; j--; )
+			mymat[j][i] *= wt;
+	}
+	if (!invmat4(inmat, mymat))	/* need inverse as well */
+		error(INTERNAL, "cannot invert BSDF transform");
+	newdist(nalt*nazi);		/* resample distribution */
+	for (i = b->ninc; i--; ) {
+		int	direct_out = -1;
+		COLOR	cdir;
+		getBSDF_incvec(dv, b, i);	/* compute incident irrad. */
+		multv3(dv, dv, mymat);
+		if (dv[2] < 0.0) {
+			dv[0] = -dv[0]; dv[1] = -dv[1]; dv[2] = -dv[2];
+			direct_out += (direct_discount != NULL);
 		}
-		rtfree = rt;
+		wt = getBSDF_incohm(b, i);
+		wt *= dv[2];			/* solid_angle*cosine(theta) */
+		cp = &idist[3*i];
+		copycolor(cinc, cp);
+		scalecolor(cinc, wt);
+		if (!direct_out) {		/* discount direct contr. */
+			cp = &direct_discount[3*i];
+			copycolor(cdir, cp);
+			scalecolor(cdir, -wt);
+			direct_out = flatindex(dv, nalt, nazi);
+		}
+		for (k = nalt; k--; )		/* loop over distribution */
+		  for (j = nazi; j--; ) {
+		    int	rstart = random();
+		    for (c = NBSDFSAMPS; c--; ) {
+			double  sp[2];
+			multisamp(sp, 2, urand(rstart+c));
+			flatdir(dv, (k + sp[0])/nalt,
+					(j + .5 - sp[1])/nazi);
+			multv3(dv, dv, inmat);
+						/* evaluate BSDF @ outgoing */
+			o = getBSDF_outndx(b, dv);
+			if (o < 0) {
+				nout++;
+				continue;
+			}
+			wt = BSDF_value(b, i, o) * (1./NBSDFSAMPS);
+			copycolor(col, cinc);
+			o = k*nazi + j;
+			if (o == direct_out)
+				addcolor(col, cdir);	/* minus direct */
+			scalecolor(col, wt);
+			cp = &distarr[3*o];
+			addcolor(cp, col);	/* sum into distribution */
+		    }
+		  }
 	}
-	return(rtfree);
-}
-
-
-static void
-mkaxes(			/* compute u and v to go with n */
-	FVECT  u,
-	FVECT  v,
-	FVECT  n
-)
-{
-	register int  i;
-
-	v[0] = v[1] = v[2] = 0.0;
-	for (i = 0; i < 3; i++)
-		if (n[i] < 0.6 && n[i] > -0.6)
-			break;
-	v[i] = 1.0;
-	fcross(u, v, n);
-	normalize(u);
-	fcross(v, n, u);
-}
-
-
-static void
-rounddir(		/* compute uniform spherical direction */
-	register FVECT  dv,
-	double  alt,
-	double  azi
-)
-{
-	double  d1, d2;
-
-	dv[2] = 1. - 2.*alt;
-	d1 = sqrt(1. - dv[2]*dv[2]);
-	d2 = 2.*PI * azi;
-	dv[0] = d1*cos(d2);
-	dv[1] = d1*sin(d2);
-}
-
-
-static void
-flatdir(		/* compute uniform hemispherical direction */
-	register FVECT  dv,
-	double  alt,
-	double  azi
-)
-{
-	double  d1, d2;
-
-	d1 = sqrt(alt);
-	d2 = 2.*PI * azi;
-	dv[0] = d1*cos(d2);
-	dv[1] = d1*sin(d2);
-	dv[2] = sqrt(1. - alt);
+	free(idist);			/* free temp space */
+	if (nout) {
+		sprintf(errmsg, "missing %.1f%% of BSDF directions",
+				100.*nout/(b->ninc*nalt*nazi*NBSDFSAMPS));
+		error(WARNING, errmsg);
+	}
 }