Using CurvedPolygon._metadata in surface-surface intersection.

src/bezier/surface.py

@@ -1134,4 +1134,5 @@ def _make_intersection(edge_info, all_edge_nodes):
             new_nodes, degree, start=start, end=end, _copy=False)
         edges.append(edge)
 
-    return curved_polygon.CurvedPolygon(*edges, _verify=False)
+    return curved_polygon.CurvedPolygon(
+        *edges, metadata=edge_info, _verify=False)

tests/functional/test_surface_surface.py

@@ -85,27 +85,13 @@
 CONFIG = utils.Config()
 
 
-def find_edge_index(edge, root_edges):
-    for index, root_edge in enumerate(root_edges):
-        if root_edge.degree != edge.degree:
-            continue
-        specialized = root_edge.specialize(edge.start, edge.end)
-        if np.allclose(specialized._nodes, edge._nodes):
-            return index
-
-    raise RuntimeError('No match found.')
-
-
 def curved_polygon_edges(intersection, root_edges_pair):
     edges1, edges2 = root_edges_pair
     root_edges = edges1 + edges2
     # Re-sort the edges to be in the same order independent of strategy.
-    edge_list = intersection._edges
-    edge_info = [
-        (find_edge_index(edge, root_edges), edge.start, edge.end)
-        for edge in edge_list
-    ]
+    edge_info = intersection._metadata
     index = edge_info.index(min(edge_info))
+    edge_list = intersection._edges
     return edge_list[index:] + edge_list[:index]
 
 

tests/unit/test_surface.py

@@ -743,6 +743,16 @@ def _basic_intersect_helper(self, **kwargs):
 
         intersection = intersections[0]
         self.assertIsInstance(intersection, bezier.CurvedPolygon)
+        self.assertEqual(
+            intersection._metadata,
+            (
+                (5, 0.5, 1.0),
+                (3, 0.0, 0.5),
+                (1, 0.5, 1.0),
+                (2, 0.0, 0.5),
+            ),
+        )
+
         cp_edges = intersection._edges
         self.assertEqual(len(cp_edges), 4)
         # Edge 0.
@@ -940,6 +950,16 @@ def test_it(self):
         )
         result = self._call_function_under_test(edge_info, edge_nodes)
         self.assertIsInstance(result, bezier.CurvedPolygon)
+        self.assertEqual(
+            result._metadata,
+            (
+                (0, 0.0, 0.25),
+                (5, 0.75, 1.0),
+                (3, 0.0, 0.25),
+                (2, 0.75, 1.0),
+            ),
+        )
+
         self.assertEqual(result.num_sides, 4)
         # pylint: disable=unbalanced-tuple-unpacking
         edge0, edge1, edge2, edge3 = result._edges