Handle MOVETO's in Path.interpolated

rcomer · rcomer · commit 67743c1e839f · 2025-04-15T19:11:20.000+01:00
diff --git a/doc/users/next_whats_new/path_interpolated.rst b/doc/users/next_whats_new/path_interpolated.rst
@@ -0,0 +1,5 @@
+``Path.interpolated`` now handles internal ``MOVETO``'s
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+If `.Path` contains internal `~.Path.MOVETO` codes, the `~.Path.interpolated` method
+is now applied to each sub-path delineated by those codes.
diff --git a/lib/matplotlib/path.py b/lib/matplotlib/path.py
@@ -667,13 +667,27 @@ 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 `LINETO` resampled to *steps* `LINETO`'s.
 
-        Codes other than `LINETO` are not handled correctly.
+        Codes other than `LINETO` and `MOVETO` are not handled correctly.
+
+        Parameters
+        ----------
+        steps : int
+            The number of `LINETO`'s in the new path for each `LINETO` in the original.
+
+        Returns
+        -------
+        Path
+            The interpolated path.
         """
         if steps == 1:
             return self
 
+        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()))
+
         vertices = simple_linear_interpolation(self.vertices, steps)
         codes = self.codes
         if codes is not None:
diff --git a/lib/matplotlib/tests/test_path.py b/lib/matplotlib/tests/test_path.py
@@ -541,3 +541,21 @@ 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 segments 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 segments with six LINETOs each
+    expected_segment_codes = [Path.MOVETO] + [Path.LINETO] * 6
+    np.testing.assert_array_equal(result.codes, expected_segment_codes * 2)
