Weight & Vertex Paint: always respect edit mode hiding on faces.

In some cases it is mandatory to be able to hide parts of the mesh
in order to paint certain areas. The Mask modifier doesn't work in
weight paint, and edit mode hiding requires using selection, which
is not always convenient.

This makes the weight and vertex paint modes always respect edit mode
hiding like sculpt mode. The change in behavior affects drawing and
building paint PBVH. Thus it affects brushes, but not menu operators
like Smooth or Normalize.

In addition, this makes the Alt-H shortcut available even without
any selection enabled, and implements Hide for vertex selection.

Differential Revision: https://developer.blender.org/D14163

1 files changed, 51 insertions, 0 deletions

diff --git a/source/blender/editors/mesh/editface.cc b/source/blender/editors/mesh/editface.cc
index 69fe69fe117..b69cd8b8606 100644
--- a/source/blender/editors/mesh/editface.cc
+++ b/source/blender/editors/mesh/editface.cc
@@ -551,3 +551,54 @@ void paintvert_select_ungrouped(Object *ob, bool extend, bool flush_flags)
     paintvert_flush_flags(ob);
   }
 }
+
+void paintvert_hide(bContext *C, Object *ob, const bool unselected)
+{
+  Mesh *const me = BKE_mesh_from_object(ob);
+
+  if (me == NULL || me->totvert == 0) {
+    return;
+  }
+
+  for (int i = 0; i < me->totvert; i++) {
+    MVert *const mvert = &me->mvert[i];
+
+    if ((mvert->flag & ME_HIDE) == 0) {
+      if (((mvert->flag & SELECT) == 0) == unselected) {
+        mvert->flag |= ME_HIDE;
+      }
+    }
+
+    if (mvert->flag & ME_HIDE) {
+      mvert->flag &= ~SELECT;
+    }
+  }
+
+  BKE_mesh_flush_hidden_from_verts(me);
+
+  paintvert_flush_flags(ob);
+  paintvert_tag_select_update(C, ob);
+}
+
+void paintvert_reveal(bContext *C, Object *ob, const bool select)
+{
+  Mesh *const me = BKE_mesh_from_object(ob);
+
+  if (me == NULL || me->totvert == 0) {
+    return;
+  }
+
+  for (int i = 0; i < me->totvert; i++) {
+    MVert *const mvert = &me->mvert[i];
+
+    if (mvert->flag & ME_HIDE) {
+      SET_FLAG_FROM_TEST(mvert->flag, select, SELECT);
+      mvert->flag &= ~ME_HIDE;
+    }
+  }
+
+  BKE_mesh_flush_hidden_from_verts(me);
+
+  paintvert_flush_flags(ob);
+  paintvert_tag_select_update(C, ob);
+}