performance enhancements

memory enhancements
prevent starting sensors more than once
fix for wifi lag issues
map scaling for huge buildings

ui/MainWindow.cpp

@@ -22,14 +22,20 @@ MainWindow::MainWindow(QWidget *parent) : QWidget(parent) {
 
 	mainMenu = new MainMenu(this);
 	infoWidget = new InfoWidget(this);
-	sensorWidget = new SensorDataWidget(this); sensorWidget->setVisible(false);
+	sensorWidget = new SensorDataWidget(this);
 
-	//sensorWidget->setVisible(false);
+	// ensure we are fullscreen
 	showMaximized();
 
 	sleep(1);
 	emit resizeEvent(nullptr);
 
+	// important! must be called AFTER window is visible
+	// otherwise MapView3D's openGL context is uninitialized.
+	sensorWidget->setVisible(false);
+	mapView2D->setVisible(true);
+	mapView3D->setVisible(false);
+
 }
 
 void MainWindow::resizeEvent(QResizeEvent* event) {