Skip to content

Backport PR #29919 on branch v3.10.x (Handle MOVETO's, CLOSEPOLY's and empty paths in Path.interpolated) #29940

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
oscargus merged 1 commit into from
Apr 18, 2025
Merged

Backport PR #29919 on branch v3.10.x (Handle MOVETO's, CLOSEPOLY's and empty paths in Path.interpolated) #29940

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
29 changes: 25 additions & 4 deletions lib/matplotlib/path.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -668,14 +668,35 @@ def intersects_bbox(self, bbox, filled=True):

def interpolated(self, steps):
"""
Return a new path resampled to length N x *steps*.
Return a new path with each segment divided into *steps* parts.

Codes other than `LINETO` are not handled correctly.
Codes other than `LINETO`, `MOVETO`, and `CLOSEPOLY` are not handled correctly.

Parameters
----------
steps : int
The number of segments in the new path for each in the original.

Returns
-------
Path
The interpolated path.
"""
if steps == 1:
if steps == 1 or len(self) == 0:
return self

vertices = simple_linear_interpolation(self.vertices, steps)
if self.codes is not None and self.MOVETO in self.codes[1:]:
return self.make_compound_path(
*(p.interpolated(steps) for p in self._iter_connected_components()))

if self.codes is not None and self.CLOSEPOLY in self.codes and not np.all(
self.vertices[self.codes == self.CLOSEPOLY] == self.vertices[0]):
vertices = self.vertices.copy()
vertices[self.codes == self.CLOSEPOLY] = vertices[0]
else:
vertices = self.vertices

vertices = simple_linear_interpolation(vertices, steps)
codes = self.codes
if codes is not None:
new_codes = np.full((len(codes) - 1) * steps + 1, Path.LINETO,
Expand Down
81 changes: 81 additions & 0 deletions lib/matplotlib/tests/test_path.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -541,3 +541,84 @@ def test_cleanup_closepoly():
cleaned = p.cleaned(remove_nans=True)
assert len(cleaned) == 1
assert cleaned.codes[0] == Path.STOP


def test_interpolated_moveto():
# Initial path has two subpaths with two LINETOs each
vertices = np.array([[0, 0],
[0, 1],
[1, 2],
[4, 4],
[4, 5],
[5, 5]])
codes = [Path.MOVETO, Path.LINETO, Path.LINETO] * 2

path = Path(vertices, codes)
result = path.interpolated(3)

# Result should have two subpaths with six LINETOs each
expected_subpath_codes = [Path.MOVETO] + [Path.LINETO] * 6
np.testing.assert_array_equal(result.codes, expected_subpath_codes * 2)


def test_interpolated_closepoly():
codes = [Path.MOVETO] + [Path.LINETO]*2 + [Path.CLOSEPOLY]
vertices = [(4, 3), (5, 4), (5, 3), (0, 0)]

path = Path(vertices, codes)
result = path.interpolated(2)

expected_vertices = np.array([[4, 3],
[4.5, 3.5],
[5, 4],
[5, 3.5],
[5, 3],
[4.5, 3],
[4, 3]])
expected_codes = [Path.MOVETO] + [Path.LINETO]*5 + [Path.CLOSEPOLY]

np.testing.assert_allclose(result.vertices, expected_vertices)
np.testing.assert_array_equal(result.codes, expected_codes)

# Usually closepoly is the last vertex but does not have to be.
codes += [Path.LINETO]
vertices += [(2, 1)]

path = Path(vertices, codes)
result = path.interpolated(2)

extra_expected_vertices = np.array([[3, 2],
[2, 1]])
expected_vertices = np.concatenate([expected_vertices, extra_expected_vertices])

expected_codes += [Path.LINETO] * 2

np.testing.assert_allclose(result.vertices, expected_vertices)
np.testing.assert_array_equal(result.codes, expected_codes)


def test_interpolated_moveto_closepoly():
# Initial path has two closed subpaths
codes = ([Path.MOVETO] + [Path.LINETO]*2 + [Path.CLOSEPOLY]) * 2
vertices = [(4, 3), (5, 4), (5, 3), (0, 0), (8, 6), (10, 8), (10, 6), (0, 0)]

path = Path(vertices, codes)
result = path.interpolated(2)

expected_vertices1 = np.array([[4, 3],
[4.5, 3.5],
[5, 4],
[5, 3.5],
[5, 3],
[4.5, 3],
[4, 3]])
expected_vertices = np.concatenate([expected_vertices1, expected_vertices1 * 2])
expected_codes = ([Path.MOVETO] + [Path.LINETO]*5 + [Path.CLOSEPOLY]) * 2

np.testing.assert_allclose(result.vertices, expected_vertices)
np.testing.assert_array_equal(result.codes, expected_codes)


def test_interpolated_empty_path():
path = Path(np.zeros((0, 2)))
assert path.interpolated(42) is path
Loading