From 3beadd2bf0f104433cc54f57ca0830fbaa46af31 Mon Sep 17 00:00:00 2001
From: Jan Petykiewicz <jan@mpxd.net>
Date: Tue, 31 Mar 2026 09:23:59 -0700
Subject: [PATCH] [Path] preserve cap extensions in normalized form, and scale
 them with scale()

---
 masque/shapes/path.py       |  6 +++++-
 masque/test/test_library.py | 16 ++++++++++++++++
 masque/test/test_path.py    | 32 +++++++++++++++++++++++++++++++-
 3 files changed, 52 insertions(+), 2 deletions(-)

diff --git a/masque/shapes/path.py b/masque/shapes/path.py
index fc8793d..3aa6f07 100644
--- a/masque/shapes/path.py
+++ b/masque/shapes/path.py
@@ -453,6 +453,8 @@ class Path(Shape):
     def scale_by(self, c: float) -> 'Path':
         self.vertices *= c
         self.width *= c
+        if self.cap_extensions is not None:
+            self.cap_extensions *= c
         return self
 
     def normalized_form(self, norm_value: float) -> normalized_shape_tuple:
@@ -476,13 +478,15 @@ class Path(Shape):
             reordered_vertices = rotated_vertices
 
         width0 = self.width / norm_value
+        cap_extensions0 = None if self.cap_extensions is None else tuple(float(v) / norm_value for v in self.cap_extensions)
 
-        return ((type(self), reordered_vertices.data.tobytes(), width0, self.cap),
+        return ((type(self), reordered_vertices.data.tobytes(), width0, self.cap, cap_extensions0),
                 (offset, scale / norm_value, rotation, False),
                 lambda: Path(
                     reordered_vertices * norm_value,
                     width=width0 * norm_value,
                     cap=self.cap,
+                    cap_extensions=None if cap_extensions0 is None else tuple(v * norm_value for v in cap_extensions0),
                     ))
 
     def clean_vertices(self) -> 'Path':
diff --git a/masque/test/test_library.py b/masque/test/test_library.py
index 0a04d98..e58bd10 100644
--- a/masque/test/test_library.py
+++ b/masque/test/test_library.py
@@ -6,6 +6,7 @@ from ..pattern import Pattern
 from ..error import LibraryError, PatternError
 from ..ports import Port
 from ..repetition import Grid
+from ..shapes import Path
 from ..file.utils import preflight
 
 if TYPE_CHECKING:
@@ -243,3 +244,18 @@ def test_library_get_name() -> None:
 
     name2 = lib.get_name("other")
     assert name2 == "other"
+
+
+def test_library_dedup_shapes_does_not_merge_custom_capped_paths() -> None:
+    lib = Library()
+    pat = Pattern()
+    pat.shapes[(1, 0)] += [
+        Path(vertices=[[0, 0], [10, 0]], width=2, cap=Path.Cap.SquareCustom, cap_extensions=(1, 2)),
+        Path(vertices=[[20, 0], [30, 0]], width=2, cap=Path.Cap.SquareCustom, cap_extensions=(3, 4)),
+        ]
+    lib["top"] = pat
+
+    lib.dedup(norm_value=1, threshold=2)
+
+    assert not lib["top"].refs
+    assert len(lib["top"].shapes[(1, 0)]) == 2
diff --git a/masque/test/test_path.py b/masque/test/test_path.py
index 766798f..1cdd872 100644
--- a/masque/test/test_path.py
+++ b/masque/test/test_path.py
@@ -1,4 +1,4 @@
-from numpy.testing import assert_equal
+from numpy.testing import assert_equal, assert_allclose
 
 from ..shapes import Path
 
@@ -79,3 +79,33 @@ def test_path_scale() -> None:
     p.scale_by(2)
     assert_equal(p.vertices, [[0, 0], [20, 0]])
     assert p.width == 4
+
+
+def test_path_scale_custom_cap_extensions() -> None:
+    p = Path(vertices=[[0, 0], [10, 0]], width=2, cap=Path.Cap.SquareCustom, cap_extensions=(1, 2))
+    p.scale_by(3)
+
+    assert_equal(p.vertices, [[0, 0], [30, 0]])
+    assert p.width == 6
+    assert p.cap_extensions is not None
+    assert_allclose(p.cap_extensions, [3, 6])
+    assert_equal(p.to_polygons()[0].get_bounds_single(), [[-3, -3], [36, 3]])
+
+
+def test_path_normalized_form_preserves_width_and_custom_cap_extensions() -> None:
+    p = Path(vertices=[[0, 0], [10, 0]], width=2, cap=Path.Cap.SquareCustom, cap_extensions=(1, 2))
+
+    intrinsic, _extrinsic, ctor = p.normalized_form(5)
+    q = ctor()
+
+    assert intrinsic[-1] == (0.2, 0.4)
+    assert q.width == 2
+    assert q.cap_extensions is not None
+    assert_allclose(q.cap_extensions, [1, 2])
+
+
+def test_path_normalized_form_distinguishes_custom_caps() -> None:
+    p1 = Path(vertices=[[0, 0], [10, 0]], width=2, cap=Path.Cap.SquareCustom, cap_extensions=(1, 2))
+    p2 = Path(vertices=[[0, 0], [10, 0]], width=2, cap=Path.Cap.SquareCustom, cap_extensions=(3, 4))
+
+    assert p1.normalized_form(1)[0] != p2.normalized_form(1)[0]