Fix sculpt mode drawing with modifiers still being wrong in some cases

Centralize logic for when to use the PBVH for drawing, fix missing tests in
mask drawing, fix missing tests for multiple windows, only do more expensive
update for all viewports at end of the stroke.

1 files changed, 20 insertions, 0 deletions

diff --git a/source/blender/blenkernel/intern/paint.c b/source/blender/blenkernel/intern/paint.c
index 5849d691b03..4de425acfc0 100644
--- a/source/blender/blenkernel/intern/paint.c
+++ b/source/blender/blenkernel/intern/paint.c
@@ -1512,3 +1512,23 @@ void BKE_sculpt_bvh_update_from_ccg(PBVH *pbvh, SubdivCCG *subdiv_ccg)
                         subdiv_ccg->grid_flag_mats,
                         subdiv_ccg->grid_hidden);
 }
+
+/* Test if PBVH can be used directly for drawing, which is faster than
+ * drawing the mesh and all updates that come with it. */
+bool BKE_sculptsession_use_pbvh_draw(const Object *ob, const View3D *v3d)
+{
+  SculptSession *ss = ob->sculpt;
+  if (ss == NULL || ss->pbvh == NULL || ss->mode_type != OB_MODE_SCULPT) {
+    return false;
+  }
+
+  if (BKE_pbvh_type(ss->pbvh) == PBVH_FACES) {
+    /* Regular mesh only draws from PBVH without modifiers and shape keys. */
+    const bool full_shading = (v3d && (v3d->shading.type > OB_SOLID));
+    return !(ss->kb || ss->modifiers_active || full_shading);
+  }
+  else {
+    /* Multires and dyntopo always draw directly from the PBVH. */
+    return true;
+  }
+}