--- ray/src/gen/mkillum2.c	2007/09/30 19:05:26	2.22
+++ ray/src/gen/mkillum2.c	2009/06/12 17:37:37	2.31
@@ -1,5 +1,5 @@
 #ifndef lint
-static const char	RCSid[] = "$Id: mkillum2.c,v 2.22 2007/09/30 19:05:26 greg Exp $";
+static const char	RCSid[] = "$Id: mkillum2.c,v 2.31 2009/06/12 17:37:37 greg Exp $";
 #endif
 /*
  * Routines to do the actual calculation for mkillum
@@ -10,11 +10,15 @@ static const char	RCSid[] = "$Id: mkillum2.c,v 2.22 20
 #include  "mkillum.h"
 #include  "face.h"
 #include  "cone.h"
-#include  "random.h"
+#include  "source.h"
 
+#ifndef NBSDFSAMPS
+#define NBSDFSAMPS	32		/* BSDF resampling count */
+#endif
 
 COLORV *	distarr = NULL;		/* distribution array */
 int		distsiz = 0;
+COLORV *	direct_discount = NULL;	/* amount to take off direct */
 
 
 void
@@ -22,7 +26,7 @@ newdist(			/* allocate & clear distribution array */
 	int siz
 )
 {
-	if (siz == 0) {
+	if (siz <= 0) {
 		if (distsiz > 0)
 			free((void *)distarr);
 		distarr = NULL;
@@ -41,25 +45,55 @@ 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(RAY *r, int rv)
+process_ray(			/* process a ray result or report error */
+	RAY *r,
+	int rv
+)
 {
 	COLORV	*colp;
 
-	if (rv == 0)
+	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 */
+raysamp(			/* queue a ray sample */
 	int  ndx,
 	FVECT  org,
 	FVECT  dir
@@ -81,6 +115,77 @@ raysamp(	/* queue a ray sample */
 
 
 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;
@@ -127,9 +232,9 @@ rounddir(		/* compute uniform spherical direction */
 }
 
 
-static void
+void
 flatdir(		/* compute uniform hemispherical direction */
-	register FVECT  dv,
+	FVECT  dv,
 	double  alt,
 	double  azi
 )
@@ -143,7 +248,26 @@ flatdir(		/* compute uniform hemispherical direction *
 	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,
@@ -166,17 +290,17 @@ my_face(		/* make an illum face */
 	char  *nm
 )
 {
-#define MAXMISS		(5*n*il->nsamps)
 	int  dim[2];
-	int  n, nalt, nazi, h, alti;
+	int  n, nalt, nazi, alti;
 	double  sp[2], r1, r2;
+	int  h;
 	FVECT  dn, org, dir;
 	FVECT  u, v;
 	double  ur[2], vr[2];
 	MAT4  xfm;
-	int  nmisses;
+	int  nallow;
 	FACE  *fa;
-	register int  i, j;
+	int  i, j;
 				/* get/check arguments */
 	fa = getface(ob);
 	if (fa->area == 0.0) {
@@ -229,10 +353,10 @@ my_face(		/* make an illum face */
 	}
 	dim[0] = random();
 				/* sample polygon */
-	nmisses = 0;
+	nallow = 5*n*il->nsamps;
 	for (dim[1] = 0; dim[1] < n; dim[1]++)
 		for (i = 0; i < il->nsamps; i++) {
-					/* random direction */
+					/* randomize direction */
 		    h = ilhash(dim, 2) + i;
 		    if (il->sd != NULL) {
 			r_BSDF_incvec(dir, il->sd, dim[1], urand(h), xfm);
@@ -246,35 +370,81 @@ my_face(		/* make an illum face */
 			    dir[j] = -dn[0]*u[j] - dn[1]*v[j] -
 						dn[2]*fa->norm[j];
 		    }
-					/* random location */
+					/* 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();
 			freeface(ob);
 			return(my_default(ob, il, nm));
 		    }
 		    if (il->sd != NULL && DOT(dir, fa->norm) < -FTINY)
-			r1 = -1.0001*il->thick - .0001;
+			r1 = -1.0001*il->thick - 5.*FTINY;
 		    else
-			r1 = .0001;
+			r1 = 5.*FTINY;
 		    for (j = 0; j < 3; j++)
 			org[j] += r1*fa->norm[j];
 					/* send sample */
 		    raysamp(dim[1], org, dir);
 		}
+				/* 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, n)) {
@@ -286,7 +456,6 @@ my_face(		/* make an illum face */
 				/* clean up */
 	freeface(ob);
 	return(0);
-#undef MAXMISS
 }
 
 
@@ -344,6 +513,7 @@ my_sphere(	/* make an illum sphere */
 					/* send sample */
 		    raysamp(dim[1]*nazi+dim[2], org, dir);
 		}
+				/* wait for all rays to finish */
 	rayclean();
 				/* write out the sphere and its distribution */
 	if (average(il, distarr, n)) {
@@ -374,7 +544,7 @@ my_ring(		/* make an illum ring */
 	FVECT  u, v;
 	MAT4  xfm;
 	CONE  *co;
-	register int  i, j;
+	int  i, j;
 				/* get/check arguments */
 	co = getcone(ob, 0);
 				/* set up sampling */
@@ -403,7 +573,7 @@ my_ring(		/* make an illum ring */
 		for (i = 0; i < il->nsamps; i++) {
 					/* next sample point */
 		    h = ilhash(dim,2) + i;
-					/* random direction */
+					/* randomize direction */
 		    if (il->sd != NULL) {
 			r_BSDF_incvec(dir, il->sd, dim[1], urand(h), xfm);
 		    } else {
@@ -413,9 +583,9 @@ my_ring(		/* make an illum ring */
 			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];
+				dir[j] = -dn[0]*u[j] - dn[1]*v[j] - dn[2]*co->ad[j];
 		    }
-					/* random location */
+					/* randomize location */
 		    multisamp(sp, 2, urand(h+8371));
 		    r3 = sqrt(CO_R0(co)*CO_R0(co) +
 			    sp[0]*(CO_R1(co)*CO_R1(co) - CO_R0(co)*CO_R0(co)));
@@ -423,20 +593,59 @@ my_ring(		/* make an illum ring */
 		    r1 = r3*cos(r2);
 		    r2 = r3*sin(r2);
 		    if (il->sd != NULL && DOT(dir, co->ad) < -FTINY)
-			r3 = -1.0001*il->thick - .0001;
+			r3 = -1.0001*il->thick - 5.*FTINY;
 		    else
-			r3 = .0001;
+			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];
 					/* send sample */
 		    raysamp(dim[1], org, dir);
 		}
+				/* 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, n)) {
@@ -448,4 +657,106 @@ 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);
+			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 */
+		    }
+		  }
+	}
+	free(idist);			/* free temp space */
+	if (nout) {
+		sprintf(errmsg, "missing %.1f%% of BSDF directions",
+				100.*nout/(b->ninc*nalt*nazi*NBSDFSAMPS));
+		error(WARNING, errmsg);
+	}
 }