Sculpt: only update draw buffers for visible nodes during paint stroke

Also applies to some other sculpt tools like filter and mask expand.

The full update happens after the paint stroke is finished, so it does not
happen on view navigation, which would cause a delay.

Ref T70295

Differential Revision: https://developer.blender.org/D5922

1 files changed, 10 insertions, 2 deletions

diff --git a/source/blender/draw/intern/draw_manager_data.c b/source/blender/draw/intern/draw_manager_data.c
index e978ae44bcd..e3d4228ec33 100644
--- a/source/blender/draw/intern/draw_manager_data.c
+++ b/source/blender/draw/intern/draw_manager_data.c
@@ -923,11 +923,19 @@ static void drw_sculpt_generate_calls(DRWSculptCallbackData *scd, bool use_vcol)
     }
   }
 
+  /* Update draw buffers only for visible nodes while painting.
+   * But do update them otherwise so navigating stays smooth. */
+  const bool update_only_visible = rv3d && (rv3d->rflag & RV3D_PAINTING);
+
   Mesh *mesh = scd->ob->data;
   BKE_pbvh_update_normals(pbvh, mesh->runtime.subdiv_ccg);
 
-  BKE_pbvh_draw_cb(
-      pbvh, use_vcol, &frustum, (void (*)(void *, GPU_PBVH_Buffers *))sculpt_draw_cb, scd);
+  BKE_pbvh_draw_cb(pbvh,
+                   use_vcol,
+                   update_only_visible,
+                   &frustum,
+                   (void (*)(void *, GPU_PBVH_Buffers *))sculpt_draw_cb,
+                   scd);
 
   if (SCULPT_DEBUG_BUFFERS) {
     int debug_node_nr = 0;