def test_rational_spline_from_elliptic_arc_has_expected_parameters():
ellipse = ConstructionEllipse(
center=(1, 1),
major_axis=(2, 0),
ratio=0.5,
start_param=0,
end_param=math.pi / 2,
)
spline = rational_bspline_from_ellipse(ellipse)
assert spline.degree == 2
cpoints = spline.control_points
assert len(cpoints) == 3
assert cpoints[0].isclose((3, 1, 0))
assert cpoints[1].isclose((3, 2, 0))
assert cpoints[2].isclose((1, 2, 0))
weights = spline.weights()
assert len(weights) == 3
assert weights[0] == 1.0
assert weights[1] == math.cos(math.pi / 4)
assert weights[2] == 1.0
# as BSpline constructor()
s2 = BSpline.from_ellipse(ellipse)
assert spline.control_points == s2.control_points
def test_rational_spline_from_elliptic_arc_has_same_end_points():
ellipse = ConstructionEllipse(
center=(1, 1),
major_axis=(2, 0),
ratio=0.5,
start_param=math.radians(30),
end_param=math.radians(330),
)
start_point = ellipse.start_point
end_point = ellipse.end_point
spline = rational_bspline_from_ellipse(ellipse)
assert start_point.isclose(spline.control_points[0])
assert end_point.isclose(spline.control_points[-1])