def _make_intersection(edge_info, all_edge_nodes):
"""Convert a description of edges into a curved polygon.
.. note::
This is a helper used only by :meth:`.Triangle.intersect`.
Args:
edge_info (Tuple[Tuple[int, float, float], ...]): Information
describing each edge in the curved polygon by indicating which
triangle / edge on the triangle and then start and end parameters
along that edge. (See :func:`.ends_to_curve`.)
all_edge_nodes (Tuple[numpy.ndarray, ...]): The nodes of three edges
of the first triangle being intersected followed by the nodes of
the three edges of the second.
Returns:
.CurvedPolygon: The intersection corresponding to ``edge_info``.
"""
edges = []
for index, start, end in edge_info:
nodes = all_edge_nodes[index]
new_nodes = _curve_helpers.specialize_curve(nodes, start, end)
degree = new_nodes.shape[1] - 1
edge = _curve_mod.Curve(new_nodes, degree, copy=False, verify=False)
edges.append(edge)
return curved_polygon.CurvedPolygon(*edges,
metadata=edge_info,
_verify=False)
def specialize(self, start, end):
"""Specialize the curve to a given sub-interval.
.. image:: ../../images/curve_specialize.png
:align: center
.. doctest:: curve-specialize
>>> nodes = np.asfortranarray([
... [0.0, 0.5, 1.0],
... [0.0, 1.0, 0.0],
... ])
>>> curve = bezier.Curve(nodes, degree=2)
>>> new_curve = curve.specialize(-0.25, 0.75)
>>> new_curve.nodes
array([[-0.25 , 0.25 , 0.75 ],
[-0.625, 0.875, 0.375]])
.. testcleanup:: curve-specialize
import make_images
make_images.curve_specialize(curve, new_curve)
This is generalized version of :meth:`subdivide`, and can even
match the output of that method:
.. testsetup:: curve-specialize2
import numpy as np
import bezier
nodes = np.asfortranarray([
[0.0, 0.5, 1.0],
[0.0, 1.0, 0.0],
])
curve = bezier.Curve(nodes, degree=2)
.. doctest:: curve-specialize2
>>> left, right = curve.subdivide()
>>> also_left = curve.specialize(0.0, 0.5)
>>> np.all(also_left.nodes == left.nodes)
True
>>> also_right = curve.specialize(0.5, 1.0)
>>> np.all(also_right.nodes == right.nodes)
True
Args:
start (float): The start point of the interval we
are specializing to.
end (float): The end point of the interval we
are specializing to.
Returns:
Curve: The newly-specialized curve.
"""
new_nodes = _curve_helpers.specialize_curve(self._nodes, start, end)
return Curve(new_nodes, self._degree, _copy=False)