--- ray/src/cv/mgflib/fvect.c	1994/06/21 14:45:44	1.1
+++ ray/src/cv/mgflib/fvect.c	2003/02/28 20:11:29	1.4
@@ -1,14 +1,12 @@
-/* Copyright (c) 1994 Regents of the University of California */
-
 #ifndef lint
-static char SCCSid[] = "$SunId$ LBL";
+static const char	RCSid[] = "$Id: fvect.c,v 1.4 2003/02/28 20:11:29 greg Exp $";
 #endif
-
 /*
  * Routines for 3-d vectors
  */
 
 #include <stdio.h>
+#include <stdlib.h>
 #include <math.h>
 #include "parser.h"
 
@@ -19,12 +17,15 @@ register FVECT  v;
 {
 	static double  len;
 	
-	len = v[0]*v[0] + v[1]*v[1] + v[2]*v[2];
+	len = DOT(v, v);
 	
 	if (len <= 0.0)
 		return(0.0);
 	
-	len = sqrt(len);
+	if (len <= 1.0+FTINY && len >= 1.0-FTINY)
+		len = 0.5 + 0.5*len;	/* first order approximation */
+	else
+		len = sqrt(len);
 
 	v[0] /= len;
 	v[1] /= len;
@@ -34,6 +35,7 @@ register FVECT  v;
 }
 
 
+void
 fcross(vres, v1, v2)		/* vres = v1 X v2 */
 register FVECT  vres, v1, v2;
 {