--- ray/src/gen/mkillum2.c	2009/09/08 23:05:47	2.33
+++ ray/src/gen/mkillum2.c	2023/11/17 20:02:07	2.43
@@ -1,5 +1,5 @@
 #ifndef lint
-static const char	RCSid[] = "$Id: mkillum2.c,v 2.33 2009/09/08 23:05:47 greg Exp $";
+static const char	RCSid[] = "$Id: mkillum2.c,v 2.43 2023/11/17 20:02:07 greg Exp $";
 #endif
 /*
  * Routines to do the actual calculation for mkillum
@@ -11,14 +11,14 @@ static const char	RCSid[] = "$Id: mkillum2.c,v 2.33 20
 #include  "face.h"
 #include  "cone.h"
 #include  "source.h"
+#include  "paths.h"
 
-#ifndef NBSDFSAMPS
-#define NBSDFSAMPS	256		/* BSDF resampling count */
+#ifndef R_EPS
+#define R_EPS		0.005		/* relative epsilon for ray origin */
 #endif
 
 COLORV *	distarr = NULL;		/* distribution array */
 int		distsiz = 0;
-COLORV *	direct_discount = NULL;	/* amount to take off direct */
 
 
 void
@@ -28,14 +28,14 @@ newdist(			/* allocate & clear distribution array */
 {
 	if (siz <= 0) {
 		if (distsiz > 0)
-			free((void *)distarr);
+			free(distarr);
 		distarr = NULL;
 		distsiz = 0;
 		return;
 	}
 	if (distsiz < siz) {
 		if (distsiz > 0)
-			free((void *)distarr);
+			free(distarr);
 		distarr = (COLORV *)malloc(sizeof(COLOR)*siz);
 		if (distarr == NULL)
 			error(SYSTEM, "out of memory in newdist");
@@ -45,27 +45,6 @@ newdist(			/* allocate & clear distribution array */
 }
 
 
-static void
-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,
@@ -80,14 +59,9 @@ process_ray(			/* process a ray result or report error
 		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 */
+	smultscolor(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);
-	}
+	addscolor(colp, r->rcol);
 	return(1);
 }
 
@@ -107,7 +81,7 @@ raysamp(			/* queue a ray sample */
 	VCOPY(myRay.rorg, org);
 	VCOPY(myRay.rdir, dir);
 	myRay.rmax = .0;
-	rayorigin(&myRay, PRIMARY, NULL, NULL);
+	rayorigin(&myRay, PRIMARY|SPECULAR, NULL, NULL);
 	myRay.rno = ndx;
 					/* queue ray, check result */
 	process_ray(&myRay, ray_pqueue(&myRay));
@@ -118,20 +92,18 @@ void
 srcsamps(			/* sample sources from this surface position */
 	struct illum_args *il,
 	FVECT org,
-	FVECT nrm,
+	double eps,
 	MAT4 ixfm
 )
 {
-	int  nalt, nazi;
+	int  nalt=1, nazi=1;
 	SRCINDEX  si;
 	RAY  sr;
 	FVECT	v;
 	double  d;
 	int  i, j;
 						/* get sampling density */
-	if (il->sampdens <= 0) {
-		nalt = nazi = 1;
-	} else {
+	if (il->sampdens > 0) {
 		i = PI * il->sampdens;
 		nalt = sqrt(i/PI) + .5;
 		nazi = PI*nalt + .5;
@@ -139,24 +111,6 @@ srcsamps(			/* sample sources from this surface positi
 	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 */
@@ -165,21 +119,14 @@ srcsamps(			/* sample sources from this surface positi
 			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];
-		}
+		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);
+		scalescolor(sr.rcoef, d);
+		VSUM(sr.rorg, sr.rorg, sr.rdir, -eps);
 		process_ray(&sr, ray_pqueue(&sr));
 	}
 }
@@ -202,22 +149,14 @@ mkaxes(			/* compute u and v to go with n */
 	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);
+	getperpendicular(u, n, 1);
 	fcross(v, n, u);
 }
 
 
 static void
 rounddir(		/* compute uniform spherical direction */
-	register FVECT  dv,
+	FVECT  dv,
 	double  alt,
 	double  azi
 )
@@ -248,6 +187,7 @@ flatdir(		/* compute uniform hemispherical direction *
 	dv[2] = sqrt(1. - alt);
 }
 
+
 int
 flatindex(		/* compute index for hemispherical direction */
 	FVECT	dv,
@@ -297,7 +237,9 @@ my_face(		/* make an illum face */
 	FVECT  dn, org, dir;
 	FVECT  u, v;
 	double  ur[2], vr[2];
+	double  epsilon;
 	MAT4  xfm;
+	char  xfrot[64];
 	int  nallow;
 	FACE  *fa;
 	int  i, j;
@@ -308,23 +250,14 @@ my_face(		/* make an illum face */
 		return(my_default(ob, il, nm));
 	}
 				/* set up sampling */
-	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;
+	if (il->sampdens <= 0) {
+		nalt = nazi = 1;	/* diffuse assumption */
 	} 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 = PI * il->sampdens;
+		nalt = sqrt(n/PI) + .5;
+		nazi = PI*nalt + .5;
 	}
+	n = nazi*nalt;
 	newdist(n);
 				/* take first edge >= sqrt(area) */
 	for (j = fa->nv-1, i = 0; i < fa->nv; j = i++) {
@@ -354,22 +287,19 @@ my_face(		/* make an illum face */
 	dim[0] = random();
 				/* sample polygon */
 	nallow = 5*n*il->nsamps;
+	epsilon = R_EPS*sqrt(fa->area);
 	for (dim[1] = 0; dim[1] < n; dim[1]++)
 		for (i = 0; i < il->nsamps; i++) {
 					/* 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++)
+		    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+nallow));
@@ -385,34 +315,21 @@ my_face(		/* make an illum face */
 			freeface(ob);
 			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] += r1*fa->norm[j];
+		    VSUM(org, org, dir, -epsilon);
 					/* send sample */
 		    raysamp(dim[1], org, dir);
 		}
 				/* add in direct component? */
-	if (!directvis && (il->flags & IL_LIGHT || il->sd != NULL)) {
+	if (il->flags & IL_LIGHT) {
 		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();
+		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.;
 		dim[0] = random();
 		nallow = 10*il->nsamps;
 		for (i = 0; i < il->nsamps; i++) {
@@ -433,19 +350,11 @@ my_face(		/* make an illum face */
 			return(my_default(ob, il, nm));
 		    }
 					/* sample source rays */
-		    srcsamps(il, org, fa->norm, ixfm);
+		    srcsamps(il, org, epsilon, 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, n)) {
 		if (il->sampdens > 0)
@@ -461,7 +370,7 @@ my_face(		/* make an illum face */
 
 int
 my_sphere(	/* make an illum sphere */
-	register OBJREC  *ob,
+	OBJREC  *ob,
 	struct illum_args  *il,
 	char  *nm
 )
@@ -471,7 +380,7 @@ my_sphere(	/* make an illum sphere */
 	double  sp[4], r1, r2, r3;
 	FVECT  org, dir;
 	FVECT  u, v;
-	register int  i, j;
+	int  i, j;
 				/* check arguments */
 	if (ob->oargs.nfargs != 4)
 		objerror(ob, USER, "bad # of arguments");
@@ -483,8 +392,6 @@ my_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;
 	newdist(n);
 	dim[0] = random();
@@ -539,32 +446,27 @@ my_ring(		/* make an illum ring */
 	int  dim[2];
 	int  n, nalt, nazi, alti;
 	double  sp[2], r1, r2, r3;
+	double  epsilon;
 	int  h;
 	FVECT  dn, org, dir;
 	FVECT  u, v;
 	MAT4  xfm;
 	CONE  *co;
 	int  i, j;
-				/* get/check arguments */
+					/* get/check arguments */
 	co = getcone(ob, 0);
-				/* set up sampling */
-	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;
+	if (co == NULL)
+		objerror(ob, USER, "cannot create illum");
+					/* set up sampling */
+	if (il->sampdens <= 0) {
+		nalt = nazi = 1;	/* diffuse assumption */
 	} 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 = PI * il->sampdens;
+		nalt = sqrt(n/PI) + .5;
+		nazi = PI*nalt + .5;
 	}
+	epsilon = R_EPS*CO_R1(co);
+	n = nazi*nalt;
 	newdist(n);
 	mkaxes(u, v, co->ad);
 	dim[0] = random();
@@ -574,17 +476,13 @@ my_ring(		/* make an illum ring */
 					/* next sample point */
 		    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];
-		    }
+		    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) +
@@ -592,35 +490,23 @@ my_ring(		/* make an illum ring */
 		    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] +
-						r3*co->ad[j];
+						epsilon*co->ad[j];
 					/* send sample */
 		    raysamp(dim[1], org, dir);
 		}
 				/* add in direct component? */
-	if (!directvis && (il->flags & IL_LIGHT || il->sd != NULL)) {
+	if (il->flags & IL_LIGHT) {
 		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();
+		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.;
 		dim[0] = random();
 		for (i = 0; i < il->nsamps; i++) {
 					/* randomize location */
@@ -634,19 +520,11 @@ my_ring(		/* make an illum ring */
 		    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);
+		    srcsamps(il, org, epsilon, 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, n)) {
 		if (il->sampdens > 0)
@@ -657,110 +535,4 @@ my_ring(		/* make an illum ring */
 				/* clean up */
 	freecone(ob);
 	return(1);
-}
-
-
-void
-redistribute(		/* pass distarr ray sums through BSDF */
-	struct BSDF_data *b,
-	int nalt,
-	int nazi,
-	FVECT u,
-	FVECT v,
-	FVECT w,
-	MAT4 xm
-)
-{
-	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.;
-	}
-	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);
-		}
-		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);
-			if (b->nout != b->ninc)
-				direct_out = flatindex(dv, nalt, nazi);
-			else
-				direct_out = i;	/* assumes dist. mirroring */
-		}
-		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);
-			if (b->nout != b->ninc)
-				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 */
-		    }
-		  }
-	}
-	free(idist);			/* free temp space */
-	if (nout) {
-		sprintf(errmsg, "missing %.1f%% of BSDF directions",
-				100.*nout/(b->ninc*nalt*nazi*NBSDFSAMPS));
-		error(WARNING, errmsg);
-	}
 }