feat(selection): separate selection geometry from image content processing

- Introduced a new design for selection rasterization that decouples the selection geometry from the image content, ensuring that the SelectionMask is independent of the source image's alpha and color.
- Updated the `rasterize_selection_path` function to only accept selection paths and image dimensions, removing parameters related to source alpha and alpha thresholds.
- Implemented a new approach for handling selection paths using non-zero winding fill, ensuring overlapping areas are preserved.
- Enhanced performance by utilizing a scanline algorithm for rasterization, significantly reducing processing time for high-resolution images.
- Updated internal documentation and added comprehensive tests to validate the new behavior and performance improvements.
- Ensured backward compatibility by maintaining existing interfaces where necessary while introducing breaking changes in the selection processing logic.

tools/node_assets/validate_mesh_plane.py

@@ -27,21 +27,15 @@ def evaluated_mesh(obj):
     return evaluated, evaluated.to_mesh()
 
 
-def modifier_input_value(modifier, identifier):
-    inputs = getattr(getattr(modifier, "properties", None), "inputs", None)
-    if inputs is not None:
-        return getattr(inputs, identifier).value
-    return modifier[identifier]
-
-
 def main():
     bpy.ops.wm.read_factory_settings(use_empty=True)
     mesh = create_mesh_plane_mesh("Mesh Plane", (-1.0, 1.0, -0.5, 0.5))
     assert len(mesh.polygons) == 1
     material = bpy.data.materials.new("Mesh Plane Material")
+    mesh.materials.append(material)
     obj = bpy.data.objects.new("Mesh Plane", mesh)
     bpy.context.scene.collection.objects.link(obj)
-    modifier = add_mesh_plane_processing(obj, material)
+    modifier = add_mesh_plane_processing(obj)
     group = modifier.node_group
     assert group.name == "O Mesh Plane"
     assert group.is_modifier
@@ -50,15 +44,15 @@ def main():
         for item in group.interface.items_tree
         if item.item_type == "SOCKET" and item.in_out == "INPUT"
     }
-    assert list(inputs) == ["Geometry", "Subdivide", "Thickness", "Material"]
+    assert list(inputs) == ["Geometry", "Subdivide", "Thickness"]
     assert inputs["Subdivide"].default_value == 0
     assert inputs["Subdivide"].max_value == 10
     assert inputs["Thickness"].default_value == 0.0
-    assert inputs["Material"].hide_in_modifier
-    assert modifier_input_value(modifier, inputs["Material"].identifier) == material
+    assert obj.data.materials[0] == material
 
     evaluated, result = evaluated_mesh(obj)
     try:
+        assert result.materials[0].original == material
         assert len(result.polygons) == 2
         assert len(result.vertices) == 6
         assert "UVMap" in result.attributes
@@ -75,6 +69,7 @@ def main():
             (1.0, 1.0),
         }
         assert all(abs(vertex.co.z) < 1e-6 for vertex in result.vertices)
+        assert all(polygon.material_index == 0 for polygon in result.polygons)
     finally:
         evaluated.to_mesh_clear()
 
@@ -92,6 +87,7 @@ def main():
     obj.update_tag(refresh={"DATA"})
     evaluated, result = evaluated_mesh(obj)
     try:
+        assert result.materials[0].original == material
         assert len(result.polygons) == 184
         z_values = [vertex.co.z for vertex in result.vertices]
         assert abs(min(z_values) + 0.6) < 1e-6
@@ -102,6 +98,17 @@ def main():
             for edge_key in polygon.edge_keys:
                 edge_users[edge_key] += 1
         assert all(users == 2 for users in edge_users.values())
+        assert all(polygon.material_index == 0 for polygon in result.polygons)
+    finally:
+        evaluated.to_mesh_clear()
+
+    set_modifier_input(modifier, modifier_input_identifier(group, "Subdivide"), 0)
+    set_modifier_input(modifier, modifier_input_identifier(group, "Thickness"), 0.01)
+    obj.update_tag(refresh={"DATA"})
+    evaluated, result = evaluated_mesh(obj)
+    try:
+        z_values = {round(vertex.co.z, 6) for vertex in result.vertices}
+        assert len(z_values) >= 4
     finally:
         evaluated.to_mesh_clear()