makePlaneReflection function

Matrix4 makePlaneReflection (Vector3 planeNormal, Vector3 planePoint)

Returns a transformation matrix that transforms points by reflecting them through the plane specified with planeNormal and planePoint.

Implementation 

Matrix4 makePlaneReflection(Vector3 planeNormal, Vector3 planePoint) {
  final Vector4 v = new Vector4(planeNormal.storage[0], planeNormal.storage[1],
      planeNormal.storage[2], 0.0);
  final Matrix4 outer = new Matrix4.outer(v, v)..scale(2.0);
  Matrix4 r = new Matrix4.zero();
  r = r - outer;
  final double scale = 2.0 * planePoint.dot(planeNormal);
  final Vector3 scaledNormal = (planeNormal.scaled(scale));
  final Vector4 T = new Vector4(scaledNormal.storage[0],
      scaledNormal.storage[1], scaledNormal.storage[2], 1.0);
  r.setColumn(3, T);
  return r;
}