def test_set():
a = Quaternion()
assert a.x == 0
assert a.y == 0
assert a.z == 0
assert a.w == 1
a.set(x, y, z, w)
assert a.x == x
assert a.y == y
assert a.z == z
assert a.w == w
def test_normalize_length_length_sq():
a = Quaternion(x, y, z, w)
assert a.length() != 1
assert a.length_sq() != 1
a.normalize()
assert a.length() == 1
assert a.length_sq() == 1
a.set(0, 0, 0, 0)
assert a.length_sq() == 0
assert a.length() == 0
a.normalize()
assert a.length_sq() == 1
assert a.length() == 1
def test_rotate_towards():
a = Quaternion()
b = Quaternion().set_from_euler(Euler(0, pi, 0))
c = Quaternion()
half_pi = pi * 0.5
a.rotate_towards(b, 0)
assert a.equals(a) is True
a.rotate_towards(b, pi * 2)
# test overshoot
assert a.equals(b) is True
a.set(0, 0, 0, 1)
a.rotate_towards(b, half_pi)
assert a.angle_to(c) - half_pi <= eps
def test_clone():
a = Quaternion().clone()
assert a.x == 0
assert a.y == 0
assert a.z == 0
assert a.w == 1
b = a.set(x, y, z, w).clone()
assert b.x == x
assert b.y == y
assert b.z == z
assert b.w == w