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# Copyright Crown and Cartopy Contributors
#
# This file is part of Cartopy and is released under the BSD 3-clause license.
# See LICENSE in the root of the repository for full licensing details.
import warnings
import matplotlib.path as mpath
import numpy as np
warnings.warn('The clip_path module is deprecated and will be removed '
'in a future release with no replacement.',
DeprecationWarning, stacklevel=2)
def intersection_point(p0, p1, p2, p3):
"""
Returns
-------
x, y
The intersection point of the two infinite lines that pass through
point p0->p1 and p2->p3 respectively.
"""
x_1, y_1 = p0
x_2, y_2 = p1
x_3, y_3 = p2
x_4, y_4 = p3
div = (x_1 - x_2) * (y_3 - y_4) - (y_1 - y_2) * (x_3 - x_4)
if div == 0:
raise ValueError('Lines are parallel and cannot '
'intersect at any one point.')
x = ((x_1 * y_2 - y_1 * x_2) * (x_3 - x_4) - (x_1 - x_2) * (x_3 *
y_4 - y_3 * x_4)) / div
y = ((x_1 * y_2 - y_1 * x_2) * (y_3 - y_4) - (y_1 - y_2) * (x_3 *
y_4 - y_3 * x_4)) / div
return x, y
def lines_intersect(p0, p1, p2, p3):
"""
Returns
-------
bool
Boolean indicating whether the two lines defined by p0->p1 and p2->p3
intersect.
"""
x_1, y_1 = p0
x_2, y_2 = p1
x_3, y_3 = p2
x_4, y_4 = p3
return (x_1 - x_2) * (y_3 - y_4) - (y_1 - y_2) * (x_3 - x_4) != 0
cp1 = np.cross(p1 - p0, p2 - p0)
cp2 = np.cross(p1 - p0, p3 - p0)
return np.sign(cp1) == np.sign(cp2) and cp1 != 0
def bbox_to_path(bbox):
"""
Turn the given :class:`matplotlib.transforms.Bbox` instance into
a :class:`matplotlib.path.Path` instance.
"""
verts = np.array([[bbox.x0, bbox.y0], [bbox.x1, bbox.y0],
[bbox.x1, bbox.y1], [bbox.x0, bbox.y1],
[bbox.x0, bbox.y0]])
return mpath.Path(verts)
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