def test_rotate_point_z(self):
p = Point(0, 1, 0)
half_quarter = Transformations.rotation_z(math.pi / 4)
full_quarter = Transformations.rotation_z(math.pi / 2)
self.assertEqual(Matrix.multiply_tuple(half_quarter, p),
Point(-math.sqrt(2) / 2,
math.sqrt(2) / 2, 0))
self.assertEqual(Matrix.multiply_tuple(full_quarter, p),
Point(-1, 0, 0))
class Clock:
if __name__ == '__main__':
canvas_size = 300
canvas = Canvas(canvas_size, canvas_size)
color = Color(1, 1, 1)
radius = canvas_size * 3 / 8
scale = Transformations.scaling(radius, radius, 0)
origin = Point(0, 0, 0)
center_translation = Transformations.translation(
canvas_size / 2, canvas_size / 2, 0)
center = Matrix.multiply_tuple(center_translation, origin)
hour = Point(0, 1, 0) # twelve
for _ in range(12):
scaled_hour = Matrix.multiply_tuple(scale, hour)
positioned_hour = scaled_hour + center
canvas.write_pixel(round(positioned_hour.x),
round(canvas.height - positioned_hour.y), color)
hour_rotation = Transformations.rotation_z(math.pi / 6)
hour = Matrix.multiply_tuple(hour_rotation, hour)
canvas.canvas_to_ppm()
def test_normal_transformed_sphere(self):
s = Sphere()
m = Transformations.scaling(1, 0.5, 1).dot(Transformations.rotation_z(math.pi / 5))
s.transform = m
n = s.normal_at(Point(0, math.sqrt(2) / 2, -(math.sqrt(2) / 2)))
self.assertEqual(n, Vector(0, 0.97014, -0.24254))
