--- ray/src/px/pf3.c	1989/02/02 10:49:26	1.1
+++ ray/src/px/pf3.c	1992/10/02 16:23:41	2.3
@@ -1,4 +1,4 @@
-/* Copyright (c) 1986 Regents of the University of California */
+/* Copyright (c) 1992 Regents of the University of California */
 
 #ifndef lint
 static char SCCSid[] = "$SunId$ LBL";
@@ -12,9 +12,11 @@ static char SCCSid[] = "$SunId$ LBL";
 
 #include  <stdio.h>
 
+#include  <math.h>
+
 #include  "color.h"
 
-#define  FTINY		1e-7
+#define	 FTINY		1e-7
 
 extern double  rad;		/* output pixel radius for filtering */
 
@@ -38,13 +40,12 @@ extern char  *progname;
 
 float  *exptable;		/* exponent table */
 
-#define  lookexp(x)		exptable[(int)(-10.*(x)+.5)]
+#define	 lookexp(x)		exptable[(int)(-10.*(x)+.5)]
 
 
 initmask()			/* initialize gaussian lookup table */
 {
 	extern char  *malloc();
-	extern double  exp();
 	register int  x;
 
 	exptable = (float *)malloc(100*sizeof(float));
@@ -66,7 +67,7 @@ int  c, r;
 	static double  d;
 	static int  y;
 	register int  x;
-	register COLOR  *scan;
+	register COLOR	*scan;
 
 	wsum = 0;
 	setcolor(csum, 0.0, 0.0, 0.0);
@@ -101,19 +102,19 @@ int  c, r;
 	static COLOR  ctmp;
 	static int  y;
 	register int  x;
-	register COLOR  *scan;
+	register COLOR	*scan;
 
 	wsum = FTINY;
 	setcolor(csum, 0.0, 0.0, 0.0);
-	for (y = ycent+1-yrad; y <= ycent+yrad; y++) {
+	for (y = ycent-yrad; y <= ycent+yrad; y++) {
 		if (y < 0 || y >= yres)
 			continue;
-		dy = (y_r*y - r)/rad;
+		dy = (y_r*(y+.5) - (r+.5))/rad;
 		scan = scanin[y%barsize];
-		for (x = xcent+1-xrad; x <= xcent+xrad; x++) {
+		for (x = xcent-xrad; x <= xcent+xrad; x++) {
 			if (x < 0 || x >= xres)
 				continue;
-			dx = (x_c*x - c)/rad;
+			dx = (x_c*(x+.5) - (c+.5))/rad;
 			weight = lookexp(-(dx*dx + dy*dy));
 			wsum += weight;
 			copycolor(ctmp, scan[x]);