--- ray/src/px/pf2.c	1992/10/02 16:23:20	2.3
+++ ray/src/px/pf2.c	2004/03/28 20:33:14	2.7
@@ -1,46 +1,26 @@
-/* Copyright (c) 1992 Regents of the University of California */
-
 #ifndef lint
-static char SCCSid[] = "$SunId$ LBL";
+static const char	RCSid[] = "$Id: pf2.c,v 2.7 2004/03/28 20:33:14 schorsch Exp $";
 #endif
-
 /*
  *  pf2.c - routines used by pfilt.
- *
- *     10/3/85
  */
 
 #include  <stdio.h>
-
+#include  <stdlib.h>
 #include  <math.h>
 
+#include  "rterror.h"
 #include  "random.h"
-
 #include  "color.h"
+#include  "pfilt.h"
 
 #define	 PI		3.14159265359
-
 #define	 FTINY		(1e-6)
 
-extern int  nrows, ncols;	/* number of rows and columns for output */
-
-extern int  xres, yres;		/* x and y resolution */
-
-extern int  avghot;		/* true means average in avgbrt spots */
-
-extern double  hotlvl;		/* brightness considered "hot" */
-
-extern int  npts;		/* # of points for stars */
-
-extern double  spread;		/* spread for star points */
-
-extern char  *progname;
-
-extern COLOR  exposure;		/* exposure for frame */
-
 #define	 AVGLVL		0.5	/* target mean brightness */
 
 double	avgbrt;			/* average picture brightness */
+long	npix;			/* # pixels in average */
 
 typedef struct	hotpix {	/* structure for avgbrt pixels */
 	struct hotpix  *next;	/* next in list */
@@ -53,37 +33,48 @@ HOTPIX	*head;			/* head of avgbrt pixel list */
 
 double	sprdfact;		/* computed spread factor */
 
+static void starpoint(COLOR  fcol, int  x, int  y, HOTPIX	 *hp);
 
-pass1init()			/* prepare for first pass */
+
+extern void
+pass1init(void)			/* prepare for first pass */
 {
 	avgbrt = 0.0;
+	npix = 0;
 	head = NULL;
 }
 
 
-pass1default()			/* for single pass */
+extern void
+pass1default(void)			/* for single pass */
 {
-	avgbrt = AVGLVL * xres * yres;
+	avgbrt = AVGLVL;
+	npix = 1;
 	head = NULL;
 }
 
 
-pass1scan(scan, y)		/* process first pass scanline */
-register COLOR	*scan;
-int  y;
+extern void
+pass1scan(		/* process first pass scanline */
+	register COLOR	*scan,
+	int  y
+)
 {
-	extern char  *malloc();
 	double	cbrt;
 	register int  x;
 	register HOTPIX	 *hp;
 
 	for (x = 0; x < xres; x++) {
 	
-		cbrt = bright(scan[x]);
+		cbrt = (*ourbright)(scan[x]);
 
-		if (avghot || cbrt < hotlvl)
-			avgbrt += cbrt;
+		if (cbrt <= 0)
+			continue;
 
+		if (avghot || cbrt < hotlvl) {
+			avgbrt += cbrt;
+			npix++;
+		}
 		if (npts && cbrt >= hotlvl) {
 			hp = (HOTPIX *)malloc(sizeof(HOTPIX));
 			if (hp == NULL) {
@@ -102,25 +93,28 @@ int  y;
 }
 
 
-pass2init()			/* prepare for final pass */
+extern void
+pass2init(void)			/* prepare for final pass */
 {
-	avgbrt /= (double)xres * yres;
-
-	if (avgbrt <= FTINY) {
-		fprintf(stderr, "%s: picture too dark\n", progname);
+	if (!npix) {
+		fprintf(stderr, "%s: picture too dark or too bright\n",
+				progname);
 		quit(1);
 	}
+	avgbrt /= (double)npix;
 
 	scalecolor(exposure,  AVGLVL/avgbrt);
 	
-	sprdfact = spread / (hotlvl * bright(exposure))
+	sprdfact = spread / (hotlvl * (*ourbright)(exposure))
 			* ((double)xres*xres + (double)yres*yres) / 4.0;
 }
 
 
-pass2scan(scan, y)		/* process final pass scanline */
-register COLOR	*scan;
-int  y;
+extern void
+pass2scan(		/* process final pass scanline */
+	register COLOR	*scan,
+	int  y
+)
 {
 	int  xmin, xmax;
 	register int  x;
@@ -152,10 +146,13 @@ int  y;
 }
 
 
-starpoint(fcol, x, y, hp)		/* pixel is on the star's point */
-COLOR  fcol;
-int  x, y;
-register HOTPIX	 *hp;
+static void
+starpoint(		/* pixel is on the star's point */
+	COLOR  fcol,
+	int  x,
+	int  y,
+	register HOTPIX	 *hp
+)
 {
 	COLOR  ctmp;
 	double	d2;