--- ray/src/gen/mkillum2.c	1991/08/13 13:45:18	1.10
+++ ray/src/gen/mkillum2.c	1994/01/07 14:51:46	2.6
@@ -26,8 +26,7 @@ char  *nm;
 	sprintf(errmsg, "(%s): cannot make illum for %s \"%s\"",
 			nm, ofun[ob->otype].funame, ob->oname);
 	error(WARNING, errmsg);
-	if (!(il->flags & IL_LIGHT))
-		printobj(il->altmat, ob);
+	printobj(il->altmat, ob);
 }
 
 
@@ -56,14 +55,32 @@ char  *nm;
 		return;
 	}
 				/* set up sampling */
-	n = PI * il->sampdens;
-	nalt = sqrt(n/PI) + .5;
-	nazi = PI*nalt + .5;
+	if (il->sampdens <= 0)
+		nalt = nazi = 1;
+	else {
+		n = PI * il->sampdens;
+		nalt = sqrt(n/PI) + .5;
+		nazi = PI*nalt + .5;
+	}
 	n = nalt*nazi;
 	distarr = (float *)calloc(n, 3*sizeof(float));
 	if (distarr == NULL)
 		error(SYSTEM, "out of memory in o_face");
-	mkaxes(u, v, fa->norm);
+				/* take first edge longer than 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];
+		u[2] = VERTEX(fa,i)[2] - VERTEX(fa,j)[2];
+		if ((r1 = DOT(u,u)) >= fa->area-FTINY)
+			break;
+	}
+	if (i < fa->nv) {	/* got one! -- let's align our axes */
+		r2 = 1.0/sqrt(r1);
+		u[0] *= r2; u[1] *= r2; u[2] *= r2;
+		fcross(v, fa->norm, u);
+	} else			/* oh well, we'll just have to wing it */
+		mkaxes(u, v, fa->norm);
+				/* now, find limits in (u,v) coordinates */
 	ur[0] = vr[0] = FHUGE;
 	ur[1] = vr[1] = -FHUGE;
 	for (i = 0; i < fa->nv; i++) {
@@ -82,15 +99,15 @@ char  *nm;
 		for (i = 0; i < il->nsamps; i++) {
 					/* random direction */
 		    h = ilhash(dim, 3) + i;
-		    peano(sp, 2, urand(h), .02);
+		    multisamp(sp, 2, urand(h));
 		    r1 = (dim[1] + sp[0])/nalt;
-		    r2 = (dim[2] + sp[1])/nazi;
+		    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 */
 		    do {
-			peano(sp, 2, urand(h+nmisses), .01);
+			multisamp(sp, 2, urand(h+4862+nmisses));
 			r1 = ur[0] + (ur[1]-ur[0]) * sp[0];
 			r2 = vr[0] + (vr[1]-vr[0]) * sp[1];
 			for (j = 0; j < 3; j++)
@@ -111,9 +128,13 @@ char  *nm;
 		    raysamp(distarr+3*(dim[1]*nazi+dim[2]), org, dir, rt);
 		}
 	rayflush(rt);
-				/* write out the face w/ distribution */
-	flatout(il, distarr, nalt, nazi, u, v, fa->norm);
-	illumout(il, ob);
+				/* write out the face and its distribution */
+	if (average(il, distarr, nalt*nazi)) {
+		if (il->sampdens > 0)
+			flatout(il, distarr, nalt, nazi, u, v, fa->norm);
+		illumout(il, ob);
+	} else
+		printobj(il->altmat, ob);
 				/* clean up */
 	freeface(ob);
 	free((char *)distarr);
@@ -138,9 +159,13 @@ char  *nm;
 	if (ob->oargs.nfargs != 4)
 		objerror(ob, USER, "bad # of arguments");
 				/* set up sampling */
-	n = 4.*PI * il->sampdens;
-	nalt = sqrt(n/PI) + .5;
-	nazi = PI*nalt + .5;
+	if (il->sampdens <= 0)
+		nalt = nazi = 1;
+	else {
+		n = 4.*PI * il->sampdens;
+		nalt = sqrt(n/PI) + .5;
+		nazi = PI*nalt + .5;
+	}
 	n = nalt*nazi;
 	distarr = (float *)calloc(n, 3*sizeof(float));
 	if (distarr == NULL)
@@ -151,10 +176,10 @@ char  *nm;
 	    for (dim[2] = 0; dim[2] < nazi; dim[2]++)
 		for (i = 0; i < il->nsamps; i++) {
 					/* next sample point */
-		    peano(sp, 4, urand(ilhash(dim,3)+i), .02);
+		    multisamp(sp, 4, urand(ilhash(dim,3)+i));
 					/* random direction */
 		    r1 = (dim[1] + sp[0])/nalt;
-		    r2 = (dim[2] + sp[1])/nazi;
+		    r2 = (dim[2] + sp[1] - .5)/nazi;
 		    rounddir(dir, r1, r2);
 					/* random location */
 		    mkaxes(u, v, dir);		/* yuck! */
@@ -172,9 +197,15 @@ char  *nm;
 		    raysamp(distarr+3*(dim[1]*nazi+dim[2]), org, dir, rt);
 		}
 	rayflush(rt);
-				/* write out the sphere w/ distribution */
-	roundout(il, distarr, nalt, nazi);
-	illumout(il, ob);
+				/* write out the sphere and its distribution */
+	if (average(il, distarr, nalt*nazi)) {
+		if (il->sampdens > 0)
+			roundout(il, distarr, nalt, nazi);
+		else
+			objerror(ob, WARNING, "diffuse distribution");
+		illumout(il, ob);
+	} else
+		printobj(il->altmat, ob);
 				/* clean up */
 	free((char *)distarr);
 }
@@ -197,9 +228,13 @@ char  *nm;
 				/* get/check arguments */
 	co = getcone(ob, 0);
 				/* set up sampling */
-	n = PI * il->sampdens;
-	nalt = sqrt(n/PI) + .5;
-	nazi = PI*nalt + .5;
+	if (il->sampdens <= 0)
+		nalt = nazi = 1;
+	else {
+		n = PI * il->sampdens;
+		nalt = sqrt(n/PI) + .5;
+		nazi = PI*nalt + .5;
+	}
 	n = nalt*nazi;
 	distarr = (float *)calloc(n, 3*sizeof(float));
 	if (distarr == NULL)
@@ -211,10 +246,10 @@ char  *nm;
 	    for (dim[2] = 0; dim[2] < nazi; dim[2]++)
 		for (i = 0; i < il->nsamps; i++) {
 					/* next sample point */
-		    peano(sp, 4, urand(ilhash(dim,3)+i), .02);
+		    multisamp(sp, 4, urand(ilhash(dim,3)+i));
 					/* random direction */
 		    r1 = (dim[1] + sp[0])/nalt;
-		    r2 = (dim[2] + sp[1])/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];
@@ -225,16 +260,20 @@ char  *nm;
 		    r1 = r3*cos(r2);
 		    r2 = r3*sin(r2);
 		    for (j = 0; j < 3; j++)
-			org[j] = CO_P0(co)[j] + r1*u[j] + r1*v[j] +
+			org[j] = CO_P0(co)[j] + r1*u[j] + r2*v[j] +
 					.001*co->ad[j];
 
 					/* send sample */
 		    raysamp(distarr+3*(dim[1]*nazi+dim[2]), org, dir, rt);
 		}
 	rayflush(rt);
-				/* write out the ring w/ distribution */
-	flatout(il, distarr, nalt, nazi, u, v, co->ad);
-	illumout(il, ob);
+				/* write out the ring and its distribution */
+	if (average(il, distarr, nalt*nazi)) {
+		if (il->sampdens > 0)
+			flatout(il, distarr, nalt, nazi, u, v, co->ad);
+		illumout(il, ob);
+	} else
+		printobj(il->altmat, ob);
 				/* clean up */
 	freecone(ob);
 	free((char *)distarr);
@@ -265,6 +304,7 @@ register struct rtproc  *rt;
 	if (rt->nrays <= 0)
 		return;
 	bzero(rt->buf+6*rt->nrays, 6*sizeof(float));
+	errno = 0;
 	if ( process(rt->pd, (char *)rt->buf, (char *)rt->buf,
 			3*sizeof(float)*rt->nrays,
 			6*sizeof(float)*(rt->nrays+1)) <