def arc_between_two_points(coordinate_system, point1, point2, radius=1, right=True):
global_point1 = coordinate_system.to_parent(point1)
global_point2 = coordinate_system.to_parent(point2)
direction = point2 - point1
distance = np.sqrt(np.dot(direction, direction))
arc_coordinate_system = Cartesian(basis=np.copy(coordinate_system.basis), origin=np.copy(global_point1),
name='Arc coordinate_system')
r_theta_phi = transforms.cartesian_to_spherical(direction)
arc_coordinate_system.rotate_axis_angle([0, 0, 1], r_theta_phi[2])
arc_coordinate_system.rotate_axis_angle([0, 1, 0], r_theta_phi[1] + np.pi/2)
x_offset = -distance / 2
y_offset = np.sqrt(radius**2 - x_offset**2)
if right:
y_offset *= -1
arc_coordinate_system.origin = arc_coordinate_system.to_parent([x_offset, y_offset, 0])
local_point1 = arc_coordinate_system.to_local(global_point1)
local_point2 = arc_coordinate_system.to_local(global_point2)
start = transforms.cartesian_to_spherical(local_point1)[2]
stop = transforms.cartesian_to_spherical(local_point2)[2]
if not right:
start = 2 * np.pi - start
stop = 2 * np.pi - stop
path = Arc(coordinate_system=arc_coordinate_system, a=radius, b=radius, start=start, stop=stop, right=right)
return path
def test_equality(self):
other_coordinate_system = Cartesian()
self.assertEqual(self.coordinate_system, other_coordinate_system)
other_coordinate_system.origin = [1, 0, 0]
self.assertNotEqual(self.coordinate_system, other_coordinate_system)
