--- ray/src/common/invmat4.c	1994/04/12 15:20:48	2.1
+++ ray/src/common/invmat4.c	2003/02/25 02:47:21	2.3
@@ -1,15 +1,14 @@
-/* Copyright (c) 1994 Regents of the University of California */
-
 #ifndef lint
-static char SCCSid[] = "$SunId$ LBL";
+static const char	RCSid[] = "$Id: invmat4.c,v 2.3 2003/02/25 02:47:21 greg Exp $";
 #endif
-
 /*
  * invmat4 - computes the inverse of mat into inverse.  Returns 1
  * if there exists an inverse, 0 otherwise.  It uses Gaussian Elimination
  * method.
  */
 
+#include "copyright.h"
+
 #include "mat4.h"
 
 
@@ -18,7 +17,8 @@ static char SCCSid[] = "$SunId$ LBL";
 #define SWAP(a,b,t) (t=a,a=b,b=t)
 
 
-invmat4(inverse,mat)
+int
+invmat4(inverse, mat)
 MAT4  inverse, mat;
 {
 	MAT4  m4tmp;
@@ -27,9 +27,7 @@ MAT4  inverse, mat;
 
 	copymat4(m4tmp, mat);
 					/* set inverse to identity */
-	for (i = 0; i < 4; i++)
-		for (j = 0; j < 4; j++)
-			inverse[i][j] = i==j ? 1.0 : 0.0;
+	setident4(inverse);
 
 	for(i = 0; i < 4; i++) {
 		/* Look for row with largest pivot and swap rows */