public Mat4f add(Mat4f rhs) {
   Mat4f m = new Mat4f();
   ArrayMath.add(arraySize(), m.e, 0, e, 0, rhs.e, 0);
   return m;
 }
 public Mat4f div(float rhs) {
   Mat4f m = new Mat4f();
   ArrayMath.div(arraySize(), m.e, 0, e, 0, rhs);
   return m;
 }