def test_rational_spline_from_circular_arc_has_same_end_points():
arc = ConstructionArc(
start_angle=30, end_angle=330)
spline = rational_bspline_from_arc(
start_angle=arc.start_angle, end_angle=arc.end_angle)
assert arc.start_point.isclose(spline.control_points[0])
assert arc.end_point.isclose(spline.control_points[-1])
def test_rational_spline_curve_points_by_nurbs_python():
arc = ConstructionArc(end_angle=90)
spline = rational_bspline_from_arc(end_angle=arc.end_angle)
curve = spline.to_nurbs_python_curve()
t = list(linspace(0, 1, 10))
points = list(spline.points(t))
expected = list(curve.evaluate_list(t))
for p, e in zip(points, expected):
assert p.isclose(e)
def test_rational_spline_derivatives_by_nurbs_python():
arc = ConstructionArc(end_angle=90)
spline = rational_bspline_from_arc(end_angle=arc.end_angle)
curve = spline.to_nurbs_python_curve()
t = list(linspace(0, 1, 10))
derivatives = list(spline.derivatives(t, n=1))
expected = [curve.derivatives(u, 1) for u in t]
for (p, d1), (e, ed1) in zip(derivatives, expected):
assert p.isclose(e)
assert d1.isclose(ed1)
def test_from_ezdxf_bspline_to_nurbs_python_curve_rational():
bspline = rational_bspline_from_arc(center=Vec3(0, 0),
radius=2,
start_angle=0,
end_angle=90)
# to NURBS-Python
curve = bspline.to_nurbs_python_curve()
assert curve.degree == 2
assert len(curve.ctrlpts) == 3
assert len(curve.knotvector) == 6 # count + order
assert curve.rational is True
assert curve.weights == [1.0, 0.7071067811865476, 1.0]
# and back to ezdxf
spline = BSpline.from_nurbs_python_curve(curve)
assert spline.degree == 2
assert len(spline.control_points) == 3
assert len(spline.knots()) == 6 # count + order
assert spline.weights() == (1.0, 0.7071067811865476, 1.0)
def test_rational_spline_from_circular_arc_has_expected_parameters():
arc = ConstructionArc(end_angle=90)
spline = rational_bspline_from_arc(end_angle=arc.end_angle)
assert spline.degree == 2
cpoints = spline.control_points
assert len(cpoints) == 3
assert cpoints[0].isclose((1, 0, 0))
assert cpoints[1].isclose((1, 1, 0))
assert cpoints[2].isclose((0, 1, 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_arc(arc)
assert spline.control_points == s2.control_points