Fix slowness when rendering dense meshes with the opening decorator

It uses a custom boolean attribute on the mesh to decide whether an edge should be displayed or not. I think later on it can be used to get rid of the dictionary accessors which make the blend file size skyrocket.

src/bonsai/bonsai/bim/module/model/opening.py

@@ -1184,12 +1184,14 @@ class DecorationsHandler:
                 bm.from_mesh(obj.data)
 
                 verts = [tuple(obj.matrix_world @ v.co) for v in bm.verts]
-                edges = [tuple([v.index for v in e.verts]) for e in bm.edges]
-                ios_edges = [(edge[0], edge[1]) for edge in obj.data.get("ios_edges", [])]
-                if ios_edges:
-                    edges = [e for e in edges if (e[0], e[1]) in ios_edges or (e[1], e[0]) in ios_edges]
+                if ios_edges_attribute := obj.data.attributes.get("ios_edges"):
+                    edges = [e for i, e in enumerate(bm.edges) if ios_edges_attribute.data[i].value]
+                else:
+                    edges = bm.edges
+                edges_indices = [tuple([v.index for v in e.verts]) for e in edges]
+
                 color = selected_elements_color if obj in context.selected_objects else special_elements_color
-                self.draw_batch("LINES", verts, color, edges)
+                self.draw_batch("LINES", verts, color, edges_indices)
 
             obj.data.calc_loop_triangles()
             tris = [tuple(t.vertices) for t in obj.data.loop_triangles]

src/bonsai/bonsai/tool/loader.py

@@ -937,7 +937,8 @@ class Loader(bonsai.core.tool.Loader):
             # ios_edges holds true edges that aren't triangulated.
             #
             # we do `.tolist()` because Blender can't assign `np.int32` to it's custom attributes
-            mesh["ios_edges"] = list(set(tuple(e) for e in ifcopenshell.util.shape.get_edges(geometry).tolist()))
+            ios_edges = list(set(tuple(e) for e in ifcopenshell.util.shape.get_edges(geometry).tolist()))
+            mesh["ios_edges"] = ios_edges
             mesh["ios_item_ids"] = ifcopenshell.util.shape.get_faces_representation_item_ids(geometry).tolist()
 
             mesh.vertices.add(num_vertices)
@@ -979,6 +980,20 @@ class Loader(bonsai.core.tool.Loader):
                 # For now, not necessary to load maps in Item mode
                 if rep.is_a("IfcShapeRepresentation"):
                     tool.Loader.load_indexed_colour_map(rep, mesh)
+
+            ios_edges_indices = [(e[0], e[1]) for e in ios_edges]
+            attribute_ios_edges = mesh.attributes.get("ios_edges")
+            if not attribute_ios_edges:
+                attribute_ios_edges = mesh.attributes.new("ios_edges", domain="EDGE", type="BOOLEAN")
+
+            attribute_ios_edges.data.foreach_set(
+                "value",
+                [
+                    (e.vertices[0], e.vertices[1]) in ios_edges_indices
+                    or (e.vertices[1], e.vertices[0]) in ios_edges_indices
+                    for e in mesh.edges
+                ],
+            )
         else:
             e = geometry.edges
             v = verts