--- ray/src/px/pinterp.c	1993/04/01 11:21:18	2.10
+++ ray/src/px/pinterp.c	1994/12/22 19:11:01	2.15
@@ -1,4 +1,4 @@
-/* Copyright (c) 1993 Regents of the University of California */
+/* Copyright (c) 1994 Regents of the University of California */
 
 #ifndef lint
 static char SCCSid[] = "$SunId$ LBL";
@@ -186,7 +186,7 @@ char	*argv[];
 	if (fillsamp == 1)
 		fillo &= ~F_BACK;
 						/* set view */
-	if (err = setview(&ourview)) {
+	if ((err = setview(&ourview)) != NULL) {
 		fprintf(stderr, "%s: %s\n", progname, err);
 		exit(1);
 	}
@@ -197,6 +197,8 @@ char	*argv[];
 	if (ourpict == NULL || ourzbuf == NULL)
 		syserror(progname);
 	bzero((char *)ourzbuf, hresolu*vresolu*sizeof(float));
+							/* new header */
+	newheader("RADIANCE", stdout);
 							/* get input */
 	for ( ; i < argc; i += 2)
 		addpicture(argv[i], argv[i+1]);
@@ -207,6 +209,8 @@ char	*argv[];
 		fillpicture(fillfunc);
 							/* close calculation */
 	caldone();
+							/* aft clipping */
+	clipaft();
 							/* add to header */
 	printargs(argc, argv, stdout);
 	if (gotvfile) {
@@ -241,8 +245,9 @@ char	*s;
 {
 	char	fmt[32];
 
-	if (isformat(s)) {
-		formatval(fmt, s);
+	if (isheadid(s))
+		return;
+	if (formatval(fmt, s)) {
 		wrongformat = strcmp(fmt, COLRFMT);
 		return;
 	}
@@ -303,7 +308,6 @@ char	*pfile, *zspec;
 		register int	x;
 		if (!isfloat(zspec) || (zvalue = atof(zspec)) <= 0.0)
 			syserror(zspec);
-			exit(1);
 		for (x = scanlen(&tresolu); x-- > 0; )
 			zin[x] = zvalue;
 	}
@@ -466,18 +470,20 @@ double	z;
 movepixel(pos)				/* reposition image point */
 FVECT	pos;
 {
+	double	d0, d1;
 	FVECT	pt, direc;
 	
 	if (pos[2] <= 0)		/* empty pixel */
 		return(-1);
+	if (normdist && theirview.type == VT_PER) {	/* adjust distance */
+		d0 = pos[0] + theirview.hoff - .5;
+		d1 = pos[1] + theirview.voff - .5;
+		pos[2] /= sqrt(1. + d0*d0*theirview.hn2 + d1*d1*theirview.vn2);
+	}
 	if (hasmatrix) {
 		pos[0] += theirview.hoff - .5;
 		pos[1] += theirview.voff - .5;
 		if (theirview.type == VT_PER) {
-			if (normdist)	/* adjust for eye-ray distance */
-				pos[2] /= sqrt( 1.
-					+ pos[0]*pos[0]*theirview.hn2
-					+ pos[1]*pos[1]*theirview.vn2 );
 			pos[0] *= pos[2];
 			pos[1] *= pos[2];
 		}
@@ -492,7 +498,7 @@ FVECT	pos;
 		pos[1] += .5 - ourview.voff;
 		return(0);
 	}
-	if (viewray(pt, direc, &theirview, pos[0], pos[1]) < 0)
+	if (viewray(pt, direc, &theirview, pos[0], pos[1]) < -FTINY)
 		return(-1);
 	pt[0] += direc[0]*pos[2];
 	pt[1] += direc[1]*pos[2];
@@ -611,6 +617,36 @@ int	(*fill)();
 }
 
 
+clipaft()			/* perform aft clipping as indicated */
+{
+	register int	x, y;
+	double	tstdist;
+	double	yzn2, vx;
+
+	if (ourview.vaft <= FTINY)
+		return;
+	tstdist = ourview.vaft;
+	for (y = 0; y < vresolu; y++) {
+		if (ourview.type == VT_PER) {		/* adjust distance */
+			yzn2 = (y+.5)/vresolu + ourview.voff - .5;
+			yzn2 = 1. + yzn2*yzn2*ourview.vn2;
+			tstdist = ourview.vaft * sqrt(yzn2);
+		}
+		for (x = 0; x < hresolu; x++)
+			if (zscan(y)[x] > tstdist) {
+				if (ourview.type == VT_PER) {
+					vx = (x+.5)/hresolu + ourview.hoff - .5;
+					if (zscan(y)[x] <= ourview.vaft *
+						sqrt(vx*vx*ourview.hn2 + yzn2))
+						continue;
+				}
+				bzero(pscan(y)[x], sizeof(COLR));
+				zscan(y)[x] = 0.0;
+			}
+	}
+}
+
+
 writepicture()				/* write out picture */
 {
 	int	y;
@@ -696,14 +732,14 @@ char	*prog, *args;
 	cp = combuf;
 	wp = argv;
 	for ( ; ; ) {
-		while (isspace(*cp)) cp++;
-		if (!*cp) break;
-		*wp++ = cp;
-		while (!isspace(*cp))
-			if (!*cp++) goto done;
-		*cp++ = '\0';
+		while (isspace(*cp))	/* nullify spaces */
+			*cp++ = '\0';
+		if (!*cp)		/* all done? */
+			break;
+		*wp++ = cp;		/* add argument to list */
+		while (*++cp && !isspace(*cp))
+			;
 	}
-done:
 	*wp = NULL;
 						/* start process */
 	if ((rval = open_process(PDesc, argv)) < 0)