def test_rotating_a_point_around_the_x_axis():
# Given
p = Point(0, 1, 0)
half_quarter = rotation_x(pi / 4)
full_quarter = rotation_x(pi / 2)
# Then
assert half_quarter * p == Point(0, sqrt(2) / 2, sqrt(2) / 2)
assert full_quarter * p == Point(0, 0, 1)
def test_the_inverse_of_an__x_rotation__rotates_in_the_opposite_direction():
# Given
p = Point(0, 1, 0)
half_quarter = rotation_x(pi / 4)
inv = half_quarter.inverse()
# Then
assert inv * p == Point(0, sqrt(2) / 2, -sqrt(2) / 2)
def test_chained_transformations_must_be_applied_in_reverse_order():
# Given
p = Point(1, 0, 1)
A = rotation_x(pi / 2)
B = scaling(5, 5, 5)
C = translation(10, 5, 7)
# When
T = C * B * A
# Then
assert T * p == Point(15, 0, 7)
def test_individual_transformations_are_applied_in_sequence():
# Given
p = Point(1, 0, 1)
A = rotation_x(pi / 2)
B = scaling(5, 5, 5)
C = translation(10, 5, 7)
# apply rotation first
# When
p2 = A * p
# Then
assert p2 == Point(1, -1, 0)
# then apply scaling
# When
p3 = B * p2
# Then
assert p3 == Point(5, -5, 0)
# then apply translation
# When
p4 = C * p3
# Then
assert p4 == Point(15, 0, 7)
if __name__ == "__main__":
# pattern = StripePattern(Color(1, 0, 0), Color(1, 1, 1))
# pattern = CheckersPattern(Color(1, 0, 0), Color(1, 1, 1))
pattern = GradientPattern(Color(1, 0, 0), Color(1, 1, 1))
# pattern = RingPattern(Color(1, 0, 0), Color(1, 1, 1))
pattern.transform = scaling(0.2, 0.2, 0.2)
floor = Plane()
floor.material = Material()
floor.material.color = Color(1, 0.9, 0.9)
# floor.material.pattern = pattern
backdrop = Plane()
backdrop.transform = \
rotation_y(pi / 3) * translation(0, 0, 5) * rotation_x(pi / 2)
backdrop2 = Plane()
backdrop2.transform = \
rotation_y(-pi / 3) * translation(0, 0, 5) * rotation_x(pi / 2)
middle = Sphere()
# middle = glass_sphere()
middle.transform = translation(-0.5, 1, 0.5)
# middle.reflective = 1.0
middle.material = Material()
middle.material.color = Color(0.1, 1, 0.5)
# middle.material.pattern = pattern
middle.material.diffuse = 0.7
middle.material.specular = 0.3
# middle.material.reflective = 1.0