remove an automatic invalidate_buffers and replace them by manually placed ones

Polyhedron/demo/Polyhedron/Polyhedron_demo_self_intersection_plugin.cpp

@@ -72,6 +72,7 @@ void Polyhedron_demo_self_intersection_plugin::on_actionSelfIntersection_trigger
         selection_item->selected_facets.insert(fb->first);
         selection_item->selected_facets.insert(fb->second);
       }
+      selection_item->invalidate_buffers();
       selection_item->setName(tr("%1 (selection) (intersecting triangles)").arg(item->name()));
       scene->addItem(selection_item);
       item->setRenderingMode(Wireframe);

Polyhedron/demo/Polyhedron/Scene.cpp

@@ -652,7 +652,6 @@ void Scene::itemChanged(Item_id i)
     if(i < 0 || i >= m_entries.size())
         return;
 
-    m_entries[i]->invalidate_buffers();
   Q_EMIT dataChanged(this->createIndex(i, 0),
                      this->createIndex(i, LastColumn));
 }

Polyhedron/demo/Polyhedron/Scene_edit_polyhedron_item.cpp

@@ -443,6 +443,7 @@ void Scene_edit_polyhedron_item::timerEvent(QTimerEvent* /*event*/)
 { // just handle deformation - paint like selection is handled in eventFilter()
   if(state.ctrl_pressing && (state.left_button_pressing || state.right_button_pressing)) {
     if(!ui_widget->ActivatePivotingCheckBox->isChecked()) {
+      invalidate_buffers();
       deform();
     }
     else {

Polyhedron/demo/Polyhedron/Scene_points_with_normal_item.cpp

@@ -93,6 +93,7 @@ Scene_points_with_normal_item::~Scene_points_with_normal_item()
 
 void Scene_points_with_normal_item::initialize_buffers(Viewer_interface *viewer) const
 {
+    compute_normals_and_vertices();
     //vao for the edges
     {
         program = getShaderProgram(PROGRAM_WITHOUT_LIGHT, viewer);
@@ -150,10 +151,9 @@ void Scene_points_with_normal_item::initialize_buffers(Viewer_interface *viewer)
         program->release();
     }
     are_buffers_filled = true;
-
-
 }
-void Scene_points_with_normal_item::compute_normals_and_vertices(void)
+
+void Scene_points_with_normal_item::compute_normals_and_vertices() const
 {
     positions_points.resize(0);
     positions_lines.resize(0);
@@ -579,7 +579,6 @@ void Scene_points_with_normal_item::set_has_normals(bool b) {
 
 void Scene_points_with_normal_item::invalidate_buffers()
 {
-    compute_normals_and_vertices();
     are_buffers_filled = false;
 }
 

Polyhedron/demo/Polyhedron/Scene_points_with_normal_item.h

@@ -105,7 +105,7 @@ private:
   using Scene_item::initialize_buffers;
   void initialize_buffers(Viewer_interface *viewer) const;
 
-  void compute_normals_and_vertices(void);
+  void compute_normals_and_vertices() const;
 
 
 }; // end class Scene_points_with_normal_item

Polyhedron/demo/Polyhedron/Scene_polyhedron_selection_item.h

@@ -604,6 +604,7 @@ public:
       polyhedron()->erase_facet((*fb)->halfedge());
     }
     selected_facets.clear();
+    invalidate_buffers();
     changed_with_poly_item();
   }
 
@@ -670,6 +671,7 @@ public:
   void changed_with_poly_item() {
     // no need to update indices
     poly_item->invalidate_buffers();
+    Q_EMIT poly_item->itemChanged();
     Q_EMIT itemChanged();
   }
 

Polyhedron/demo/Polyhedron/Scene_polyhedron_shortest_path_item.cpp

@@ -177,6 +177,8 @@ void Scene_polyhedron_shortest_path_item::ensure_shortest_paths_tree()
 void Scene_polyhedron_shortest_path_item::poly_item_changed()
 {
   recreate_shortest_path_object();
+  invalidate_buffers();
+  Q_EMIT itemChanged();
 }
   
 void Scene_polyhedron_shortest_path_item::invalidate_buffers()