def test_a_stripe_pattern_is_constant_in_z(self):
black = Color(0, 0, 0)
white = Color(1, 1, 1)
p = StripePattern(white, black)
self.assertTrue(white.equals(p.pattern_at(Point(0, 0, 0))))
self.assertTrue(white.equals(p.pattern_at(Point(0, 0, 1))))
self.assertTrue(white.equals(p.pattern_at(Point(0, 0, 2))))
def test_stripes_with_an_object_transformation(self):
black = Color(0, 0, 0)
white = Color(1, 1, 1)
s = Sphere()
s.set_transform(scale(2, 2, 2))
p = StripePattern(white, black)
c = p.pattern_at_shape(s, Point(1.5, 0, 0))
self.assertTrue(c.equals(white))
def test_a_stripe_pattern_alternates_in_x(self):
black = Color(0, 0, 0)
white = Color(1, 1, 1)
p = StripePattern(white, black)
self.assertTrue(white.equals(p.pattern_at(Point(0, 0, 0))))
self.assertTrue(white.equals(p.pattern_at(Point(0.9, 0, 0))))
self.assertTrue(black.equals(p.pattern_at(Point(1, 0, 0))))
self.assertTrue(black.equals(p.pattern_at(Point(-0.1, 0, 0))))
self.assertTrue(black.equals(p.pattern_at(Point(-1, 0, 0))))
self.assertTrue(white.equals(p.pattern_at(Point(-1.1, 0, 0))))
def test_lighting_with_a_pattern_applied(self):
sp = StripePattern(Color(1, 1, 1), Color(0, 0, 0))
m = Material()
m.pattern = sp
m.ambient = 1
m.diffuse = 0
m.specular = 0
eyev = Vector(0, 0, -1)
normalv = Vector(0, 0, -1)
light = Light(Point(0, 0, -10), Color(1, 1, 1))
c1 = m.lighting(Sphere(), light, Point(0.9, 0, 0), eyev, normalv,
False)
c2 = m.lighting(Sphere(), light, Point(1.1, 0, 0), eyev, normalv,
False)
self.assertTrue(c1.equals(Color(1, 1, 1)))
self.assertTrue(c2.equals(Color(0, 0, 0)))
def test_creating_a_stripe_pattern(self):
black = Color(0, 0, 0)
white = Color(1, 1, 1)
p = StripePattern(white, black)
p.a = white
p.b = black