def test_normal_with_transform(self):
s = Sphere()
s.transform = Matrix.translate(0, 5, 0)
n = s.normal(Point(1, 5, 0))
self.assertEqual(n, Vector(1, 0, 0))
s = Sphere()
s.transform = Matrix.scale(1, 0.5, 1)
r = math.sqrt(2) / 2
n = s.normal(Point(0, r, -r))
self.assertTupleEqual(n, Vector(0, 0.97014, -0.24254))
def test_normal(self):
s = Sphere()
n = s.normal(Point(1, 0, 0))
self.assertEqual(n, Vector(1, 0, 0))
n = s.normal(Point(0, 1, 0))
self.assertEqual(n, Vector(0, 1, 0))
n = s.normal(Point(0, 0, 1))
self.assertEqual(n, Vector(0, 0, 1))
r = math.sqrt(3) / 3
n = s.normal(Point(r, r, r))
self.assertEqual(n, Vector(r, r, r))
self.assertEqual(n, n.norm())