EditMesh: Avoid creating deform-vert layer every redraw

Getting a new edit-derived-bmesh was always creating a deform-vert array, even when it wasn't needed.
Since this was called on redraw, in many cases it was doing it unnecessarily.

Now pass in a custom-data mask and only fill in deform-verts when needed.

Gives noticeable drawing speedup (~10-30% here).

1 files changed, 7 insertions, 4 deletions

diff --git a/source/blender/editors/space_view3d/drawobject.c b/source/blender/editors/space_view3d/drawobject.c
index 7c12b8ea7a5..1999ff7a6cf 100644
--- a/source/blender/editors/space_view3d/drawobject.c
+++ b/source/blender/editors/space_view3d/drawobject.c
@@ -4250,12 +4250,15 @@ static bool draw_mesh_object(Scene *scene, ARegion *ar, View3D *v3d, RegionView3
 	if (ob == obedit || drawlinked) {
 		DerivedMesh *finalDM, *cageDM;
 		
-		if (obedit != ob)
-			finalDM = cageDM = editbmesh_get_derived_base(ob, em);
-		else
+		if (obedit != ob) {
+			finalDM = cageDM = editbmesh_get_derived_base(
+			        ob, em, scene->customdata_mask);
+		}
+		else {
 			cageDM = editbmesh_get_derived_cage_and_final(
 			        scene, ob, em, scene->customdata_mask,
 			        &finalDM);
+		}
 
 		const bool use_material = ((me->drawflag & ME_DRAWEIGHT) == 0);
 
@@ -8480,7 +8483,7 @@ static void draw_object_mesh_instance(Scene *scene, View3D *v3d, RegionView3D *r
 	DerivedMesh *dm = NULL, *edm = NULL;
 	
 	if (ob->mode & OB_MODE_EDIT) {
-		edm = editbmesh_get_derived_base(ob, me->edit_btmesh);
+		edm = editbmesh_get_derived_base(ob, me->edit_btmesh, CD_MASK_BAREMESH);
 		DM_update_materials(edm, ob);
 	}
 	else {