--- ray/src/gen/mkillum2.c	1991/08/22 12:12:23	1.11
+++ ray/src/gen/mkillum2.c	2003/06/30 14:59:11	2.11
@@ -1,19 +1,15 @@
-/* Copyright (c) 1991 Regents of the University of California */
-
 #ifndef lint
-static char SCCSid[] = "$SunId$ LBL";
+static const char	RCSid[] = "$Id: mkillum2.c,v 2.11 2003/06/30 14:59:11 schorsch Exp $";
 #endif
-
 /*
  * Routines to do the actual calculation for mkillum
  */
 
-#include  "mkillum.h"
+#include <string.h>
 
+#include  "mkillum.h"
 #include  "face.h"
-
 #include  "cone.h"
-
 #include  "random.h"
 
 
@@ -26,8 +22,7 @@ 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);
 }
 
 
@@ -67,7 +62,21 @@ char  *nm;
 	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++) {
@@ -88,7 +97,7 @@ char  *nm;
 		    h = ilhash(dim, 3) + i;
 		    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];
@@ -105,7 +114,7 @@ char  *nm;
 			objerror(ob, WARNING, "bad aspect");
 			rt->nrays = 0;
 			freeface(ob);
-			free((char *)distarr);
+			free((void *)distarr);
 			o_default(ob, il, rt, nm);
 			return;
 		    }
@@ -116,13 +125,15 @@ char  *nm;
 		}
 	rayflush(rt);
 				/* write out the face and its distribution */
-	average(il, distarr, nalt*nazi);
-	if (il->sampdens > 0)
-		flatout(il, distarr, nalt, nazi, u, v, fa->norm);
-	illumout(il, ob);
+	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);
+	free((void *)distarr);
 #undef MAXMISS
 }
 
@@ -148,8 +159,8 @@ char  *nm;
 		nalt = nazi = 1;
 	else {
 		n = 4.*PI * il->sampdens;
-		nalt = sqrt(n/PI) + .5;
-		nazi = PI*nalt + .5;
+		nalt = sqrt(2./PI*n) + .5;
+		nazi = PI/2.*nalt + .5;
 	}
 	n = nalt*nazi;
 	distarr = (float *)calloc(n, 3*sizeof(float));
@@ -164,7 +175,7 @@ char  *nm;
 		    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! */
@@ -183,14 +194,16 @@ char  *nm;
 		}
 	rayflush(rt);
 				/* write out the sphere and its distribution */
-	average(il, distarr, nalt*nazi);
-	if (il->sampdens > 0)
-		roundout(il, distarr, nalt, nazi);
-	else
-		objerror(ob, WARNING, "diffuse distribution");
-	illumout(il, ob);
+	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);
+	free((void *)distarr);
 }
 
 
@@ -232,7 +245,7 @@ char  *nm;
 		    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];
@@ -243,7 +256,7 @@ 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 */
@@ -251,13 +264,15 @@ char  *nm;
 		}
 	rayflush(rt);
 				/* write out the ring and its distribution */
-	average(il, distarr, nalt*nazi);
-	if (il->sampdens > 0)
-		flatout(il, distarr, nalt, nazi, u, v, co->ad);
-	illumout(il, ob);
+	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);
+	free((void *)distarr);
 }
 
 
@@ -284,11 +299,12 @@ register struct rtproc  *rt;
 
 	if (rt->nrays <= 0)
 		return;
-	bzero(rt->buf+6*rt->nrays, 6*sizeof(float));
-	if ( process(rt->pd, (char *)rt->buf, (char *)rt->buf,
-			3*sizeof(float)*rt->nrays,
+	memset(rt->buf+6*rt->nrays, '\0', 6*sizeof(float));
+	errno = 0;
+	if ( process(&(rt->pd), (char *)rt->buf, (char *)rt->buf,
+			3*sizeof(float)*(rt->nrays+1),
 			6*sizeof(float)*(rt->nrays+1)) <
-			3*sizeof(float)*rt->nrays )
+			3*sizeof(float)*(rt->nrays+1) )
 		error(SYSTEM, "error reading from rtrace process");
 	i = rt->nrays;
 	while (i--) {