--- ray/src/px/pinterp.c	1996/06/24 09:17:47	2.28
+++ ray/src/px/pinterp.c	1999/07/16 16:11:31	2.32
@@ -1,7 +1,7 @@
-/* Copyright (c) 1995 Regents of the University of California */
+/* Copyright (c) 1999 Silicon Graphics, Inc. */
 
 #ifndef lint
-static char SCCSid[] = "$SunId$ LBL";
+static char SCCSid[] = "$SunId$ SGI";
 #endif
 
 /*
@@ -39,7 +39,7 @@ static char SCCSid[] = "$SunId$ LBL";
 
 #define PACKSIZ		256		/* max. calculation packet size */
 
-#define RTCOM		"rtrace -h- -ovl -fff "
+#define RTCOM		"rtrace -h- -ovl -fff -ld- -i- -I- "
 
 #define ABS(x)		((x)>0?(x):-(x))
 
@@ -328,20 +328,21 @@ userr:
 }
 
 
+int
 headline(s)				/* process header string */
 char	*s;
 {
 	char	fmt[32];
 
 	if (isheadid(s))
-		return;
+		return(0);
 	if (formatval(fmt, s)) {
 		if (globmatch(ourfmt, fmt)) {
 			wrongformat = 0;
 			strcpy(ourfmt, fmt);
 		} else
 			wrongformat = 1;
-		return;
+		return(0);
 	}
 	if (nvavg < 2) {
 		putc('\t', stdout);
@@ -349,10 +350,11 @@ char	*s;
 	}
 	if (isexpos(s)) {
 		theirexp *= exposval(s);
-		return;
+		return(0);
 	}
 	if (isview(s) && sscanview(&theirview, s) > 0)
 		gotview++;
+	return(0);
 }
 
 
@@ -672,7 +674,6 @@ register FVECT	pos;
 {
 	FVECT	pt, tdir, odir;
 	double	d;
-	register int	i;
 	
 	if (pos[2] <= 0)		/* empty pixel */
 		return(0);
@@ -717,15 +718,18 @@ register FVECT	pos;
 		return(0);
 	if (!averaging)
 		return(1);
-	if (ourview.type == VT_PAR)		/* compute our direction */
-		VCOPY(odir, ourview.vdir);
-	else
-		for (i = 0; i < 3; i++)
-			odir[i] = (pt[i] - ourview.vp[i])/pos[2];
-	d = DOT(odir,tdir);			/* compute pixel weight */
-	if (d >= 1.-1./MAXWT/MAXWT)
+						/* compute pixel weight */
+	if (ourview.type == VT_PAR) {
+		d = DOT(ourview.vdir,tdir);
+		d = 1. - d*d;
+	} else {
+		VSUB(odir, pt, ourview.vp);
+		d = DOT(odir,tdir);
+		d = 1. - d*d/DOT(odir,odir);
+	}
+	if (d <= 1./MAXWT/MAXWT)
 		return(MAXWT);		/* clip to maximum weight */
-	return(1./sqrt(1.-d));
+	return(1./sqrt(d));
 }
 
 
@@ -1169,9 +1173,9 @@ clearqueue()				/* process queue */
 	}
 					/* mark end and get results */
 	bzero((char *)fbp, 6*sizeof(float));
-	if (process(PDesc, fbuf, fbuf, 4*sizeof(float)*queuesiz,
+	if (process(PDesc, fbuf, fbuf, 4*sizeof(float)*(queuesiz+1),
 			6*sizeof(float)*(queuesiz+1)) !=
-			4*sizeof(float)*queuesiz) {
+			4*sizeof(float)*(queuesiz+1)) {
 		fprintf(stderr, "%s: error reading from rtrace process\n",
 				progname);
 		exit(1);