--- ray/src/rt/rpict.c	1993/12/22 21:03:54	2.37
+++ ray/src/rt/rpict.c	1995/12/08 18:49:20	2.41
@@ -1,4 +1,4 @@
-/* Copyright (c) 1993 Regents of the University of California */
+/* Copyright (c) 1995 Regents of the University of California */
 
 #ifndef lint
 static char SCCSid[] = "$SunId$ LBL";
@@ -64,9 +64,16 @@ int  vspretest = 512;			/* virtual source pretest dens
 int  directvis = 1;			/* sources visible? */
 double	srcsizerat = .25;		/* maximum ratio source size/dist. */
 
+COLOR  cextinction = BLKCOLOR;		/* global extinction coefficient */
+double  salbedo = 0.;			/* global scattering albedo */
+double  seccg = 0.;			/* global scattering eccentricity */
+double  ssampdist = 0.;			/* scatter sampling distance */
+
 double	specthresh = .15;		/* specular sampling threshold */
 double	specjitter = 1.;		/* specular sampling jitter */
 
+int  backvis = 1;			/* back face visibility */
+
 int  maxdepth = 6;			/* maximum recursion depth */
 double	minweight = 5e-3;		/* minimum ray weight */
 
@@ -500,7 +507,7 @@ int  xres, y, xstep;
 			b = fillsample(scanline, zline, 0, y, i, 0, b/2);
 		else
 			b = fillsample(scanline+i-xstep,
-					zline ? zline+i-xstep : NULL,
+					zline ? zline+i-xstep : (float *)NULL,
 					i-xstep, y, xstep, 0, b/2);
 		if (sd) *sd++ = nc & 1 ? bl : b;
 		bl = b;
@@ -528,7 +535,7 @@ int  xres, y, ysize;
 			zline[ysize] = zbar[ysize][i];
 		}
 		
-		b = fillsample(vline, zbar[0] ? zline : NULL,
+		b = fillsample(vline, zbar[0] ? zline : (float *)NULL,
 				i, y, 0, ysize, b/2);
 		
 		for (j = 1; j < ysize; j++)
@@ -586,7 +593,8 @@ int  b;
 							/* recurse */
 	ncut += fillsample(colline, zline, x, y, xlen>>1, ylen>>1, (b-1)/2);
 	
-	ncut += fillsample(colline+(len>>1), zline ? zline+(len>>1) : NULL,
+	ncut += fillsample(colline+(len>>1),
+			zline ? zline+(len>>1) : (float *)NULL,
 			x+(xlen>>1), y+(ylen>>1),
 			xlen-(xlen>>1), ylen-(ylen>>1), b/2);
 
@@ -601,8 +609,8 @@ int  x, y;			/* pixel position */
 {
 	static RAY  thisray;
 
-	if (viewray(thisray.rorg, thisray.rdir, &ourview,
-			(x+pixjitter())/hres, (y+pixjitter())/vres) < 0) {
+	if ((thisray.rmax = viewray(thisray.rorg, thisray.rdir, &ourview,
+			(x+pixjitter())/hres, (y+pixjitter())/vres)) < -FTINY) {
 		setcolor(col, 0.0, 0.0, 0.0);
 		return(0.0);
 	}