Optimize sculpt undo, avoid redundant updates

On undo, sculpting regular meshes would update _all_ GPU VBO's.
Avoiding the update gives noticeably faster undo.

This is also a fix/workaround for strange behavior with NVidia's driver (T47232),
Where locking and unlocking all buffers for updating
slows down redraw speed permanently after the first undo.

However the problem isn't avoided entirely since a single brush stroke might modify most of the mesh.

1 files changed, 2 insertions, 0 deletions

diff --git a/source/blender/blenkernel/BKE_pbvh.h b/source/blender/blenkernel/BKE_pbvh.h
index 5d69cb51ab1..927303f8b3c 100644
--- a/source/blender/blenkernel/BKE_pbvh.h
+++ b/source/blender/blenkernel/BKE_pbvh.h
@@ -349,6 +349,8 @@ void BKE_pbvh_node_get_bm_orco_data(
         PBVHNode *node,
         int (**r_orco_tris)[3], int *r_orco_tris_num, float (**r_orco_coords)[3]);
 
+bool BKE_pbvh_node_vert_update_check_any(PBVH *bvh, PBVHNode *node);
+
 //void BKE_pbvh_node_BB_reset(PBVHNode *node);
 //void BKE_pbvh_node_BB_expand(PBVHNode *node, float co[3]);