def add_spline(path: Path, spline: BSpline, level=4, reset=True) -> None:
""" Add a B-spline as multiple cubic Bèzier-curves.
Non-rational B-splines of 3rd degree gets a perfect conversion to
cubic bezier curves with a minimal count of curve segments, all other
B-spline require much more curve segments for approximation.
Auto-detect the connection point to the given `path`, if neither the start-
nor the end point of the B-spline is close to the path end point, a line
from the path end point to the start point of the B-spline will be added
automatically. (see :meth:`add_bezier4p`).
By default the start of an **empty** path is set to the start point of
the spline, setting argument `reset` to ``False`` prevents this
behavior.
Args:
path: :class:`~ezdxf.path.Path` object
spline: B-spline parameters as :class:`~ezdxf.math.BSpline` object
level: subdivision level of approximation segments
reset: set start point to start of spline if path is empty
"""
if len(path) == 0 and reset:
path.start = spline.point(0)
if spline.degree == 3 and not spline.is_rational and spline.is_clamped:
curves = [Bezier4P(points) for points in spline.bezier_decomposition()]
else:
curves = spline.cubic_bezier_approximation(level=level)
add_bezier4p(path, curves)
def random_point_comparision_to_nurbs_python(spline: BSpline, count: int = 10):
curve = spline.to_nurbs_python_curve()
for _ in range(count):
t = random.random()
p1 = spline.point(t)
p2 = curve.evaluate_single(t)
assert p1.isclose(p2)