adjust light functionality,

bugs:
- background cannot be changed during runtime

QtMeshViewer/Header/OglViewerWidget.h

@@ -38,7 +38,7 @@ private:
 	} m_rotDirections;
 
 	struct {
-		QVector3D position = { 10,10,10 };
+		QVector3D position = { 1,1,1 };
 		QVector3D intensities = { 1,0.25,0.25 };
 	} m_light;
 
@@ -50,7 +50,7 @@ private:
 	QQuaternion m_rotation;
 
 	bool m_wireframe = false;
-	bool m_lightOn = true;
+	bool m_lightOn = false;
 
 protected:
 	void mousePressEvent(QMouseEvent *e) Q_DECL_OVERRIDE;
@@ -68,6 +68,7 @@ protected:
 private:
 	void initShaders();
 	void setConnections();
+	void updateLightPosition();
 
 private slots:
 	void resetView();
@@ -75,5 +76,6 @@ private slots:
 public slots:
 	void changeDirection(int direction);
 	void toggleWireframe();
+	void toggleLight();
 };