Add option to disable recenter on visibility changed

Polyhedron/demo/Polyhedron/MainWindow.cpp

@@ -1575,6 +1575,7 @@ void MainWindow::readSettings()
     QSettings settings;
     viewer->setAntiAliasing(settings.value("antialiasing", false).toBool());
     viewer->setFastDrawing(settings.value("quick_camera_mode", true).toBool());
+    scene->enableVisibilityRecentering(settings.value("offset_update", true).toBool());
     viewer->textRenderer()->setMax(settings.value("max_text_items", 10000).toInt());
     viewer->setTotalPass(settings.value("transparency_pass_number", 4).toInt());
     CGAL::Three::Three::s_defaultSMRM = CGAL::Three::Three::modeFromName(
@@ -1947,6 +1948,11 @@ void MainWindow::on_actionPreferences_triggered()
   QSettings settings;
   prefdiag.setupUi(&dialog);
   
+  prefdiag.offset_updateCheckBox->setChecked(
+        settings.value("offset_update", true).toBool());
+  connect(prefdiag.offset_updateCheckBox, SIGNAL(toggled(bool)),
+          scene, SLOT(enableVisibilityRecentering(bool)));
+  
   prefdiag.antialiasingCheckBox->setChecked(settings.value("antialiasing", false).toBool());
   connect(prefdiag.antialiasingCheckBox, SIGNAL(toggled(bool)),
           viewer, SLOT(setAntiAliasing(bool)));
@@ -2042,6 +2048,8 @@ void MainWindow::on_actionPreferences_triggered()
     //write settings
     settings.setValue("antialiasing",
                       prefdiag.antialiasingCheckBox->isChecked());
+    settings.setValue("offset_update",
+                      prefdiag.offset_updateCheckBox->isChecked());
     settings.setValue("quick_camera_mode",
                       prefdiag.quick_cameraCheckBox->isChecked());
     settings.setValue("transparency_pass_number",

Polyhedron/demo/Polyhedron/Preferences.ui

@@ -78,6 +78,13 @@
               </property>
              </widget>
             </item>
+            <item>
+             <widget class="QCheckBox" name="offset_updateCheckBox">
+              <property name="text">
+               <string>Visibility Changes Recenter</string>
+              </property>
+             </widget>
+            </item>
             <item>
              <widget class="QSpinBox" name="max_itemsSpinBox">
               <property name="sizePolicy">

Polyhedron/demo/Polyhedron/Scene.cpp

@@ -1201,6 +1201,7 @@ void Scene::itemVisibilityChanged(CGAL::Three::Scene_item* item)
      && !item->isEmpty())
   {
     //does not recenter
+    if(visibility_recentering_enabled)
       Q_EMIT updated_bbox(false);
   }
 }
@@ -1662,3 +1663,8 @@ void Scene::adjustIds(Item_id removed_id)
     m_entries[i]->setId(i-1);//the signal is emitted before m_entries is amputed from the item, so new id is current id -1.
   }
 }
+
+void Scene::enableVisibilityRecentering(bool b)
+{
+  visibility_recentering_enabled = b;
+}

Polyhedron/demo/Polyhedron/Scene.h

@@ -208,6 +208,7 @@ public Q_SLOTS:
   void setItemA(int i);
   //!Sets the item_B as the item at index i .
   void setItemB(int i);
+  void enableVisibilityRecentering(bool);
 
 Q_SIGNALS:
   //generated automatically by moc
@@ -280,6 +281,7 @@ private:
   QOpenGLShaderProgram program;
   QOpenGLVertexArrayObject* vao;
   mutable QOpenGLBuffer vbo[2];
+  bool visibility_recentering_enabled;
 
 }; // end class Scene