optimize game view performance

src/noggit/MapView.cpp

@@ -3998,20 +3998,22 @@ void MapView::tick (float dt)
         if (moving)
         {
             _camera.move_forward(moving, dt);
+            _camera_moved_since_last_draw = true;
             // TODO use normalized speed (doesn't slow down when looking up)
             // _camera.move_forward_normalized(moving, dt);
         }
         if (strafing)
         {
             _camera.move_horizontal(strafing, dt);
+            _camera_moved_since_last_draw = true;
         }
-
         // get ground z position
-        // can be optimized by calling this only when moving/strafing or changing camera mode.
-        auto ground_pos = _world.get()->get_ground_height(_camera.position);
-        _camera.position.y = ground_pos.y + 2;
-        _camera_moved_since_last_draw = true;
-
+        // hack to update camera when entering mode in void ViewToolbar::add_tool_icon()
+        if (_camera_moved_since_last_draw)
+        {
+            auto ground_pos = _world.get()->get_ground_height(_camera.position);
+            _camera.position.y = ground_pos.y + 2;
+        }
     }
     else
     {

src/noggit/MapView.h

@@ -280,6 +280,7 @@ public:
   void randomizeStampRotation();
   void onSettingsSave();
   void updateRotationEditor() { _rotation_editor_need_update = true; };
+  void setCameraDirty() { _camera_moved_since_last_draw = true; };
 
   [[nodiscard]]
   Noggit::Ui::minimap_widget* getMinimapWidget() const { return _minimap;  }

src/noggit/ui/tools/ViewToolbar/Ui/ViewToolbar.cpp

@@ -398,7 +398,16 @@ void ViewToolbar::add_tool_icon(MapView* mapView,
         }
     });
 
-    connect (view_state, &Noggit::BoolToggleProperty::changed, [action, view_state] () {
+    connect (view_state, &Noggit::BoolToggleProperty::changed, [action, view_state, mapView] () {
+        if (action->text() == "Game view" && view_state->get())
+        {
+            // hack, manually update camera when switch to game_view
+            mapView->setCameraDirty();
+            auto ground_pos = mapView->getWorld()->get_ground_height(mapView->getCamera()->position);
+            mapView->getCamera()->position.y = ground_pos.y + 2;
+        }
+
+
         action->setChecked(view_state->get());
     });