--- ray/src/common/mat4.c	1991/11/12 16:54:53	2.1
+++ ray/src/common/mat4.c	1994/06/23 10:22:20	2.2
@@ -59,59 +59,3 @@ register MAT4  m4;
 	p3a[1] += m4[3][1];
 	p3a[2] += m4[3][2];
 }
-
-
-/*
- * invmat - computes the inverse of mat into inverse.  Returns 1
- * if there exists an inverse, 0 otherwise.  It uses Gaussian Elimination
- * method with partial pivoting.
- */
-
-invmat(inverse,mat)
-MAT4  mat, inverse;
-{
-#define SWAP(a,b,t) (t=a,a=b,b=t)
-#define ABS(x) (x>=0?x:-(x))
-
-	register int i,j,k;
-	register double temp;
-
-	copymat4(m4tmp, mat);
-	setident4(inverse);
-
-	for(i = 0; i < 4; i++) {
-		/* Look for row with largest pivot and swap rows */
-		temp = 0; j = -1;
-		for(k = i; k < 4; k++)
-			if(ABS(m4tmp[k][i]) > temp) {
-				temp = ABS(m4tmp[k][i]);
-				j = k;
-				}
-		if(j == -1)	/* No replacing row -> no inverse */
-			return(0);
-		if (j != i)
-			for(k = 0; k < 4; k++) {
-				SWAP(m4tmp[i][k],m4tmp[j][k],temp);
-				SWAP(inverse[i][k],inverse[j][k],temp);
-				}
-
-		temp = m4tmp[i][i];
-		for(k = 0; k < 4; k++) {
-			m4tmp[i][k] /= temp;
-			inverse[i][k] /= temp;
-			}
-		for(j = 0; j < 4; j++) {
-			if(j != i) {
-				temp = m4tmp[j][i];
-				for(k = 0; k < 4; k++) {
-					m4tmp[j][k] -= m4tmp[i][k]*temp;
-					inverse[j][k] -= inverse[i][k]*temp;
-					}
-				}
-			}
-		}
-	return(1);
-
-#undef ABS
-#undef SWAP
-}