public function configure($_array = NULL) {
		if ( $_array != NULL ) {
			if ( isset( $_array['x'] ) ) $this->_config['x'] = $_array['x'];
			if ( isset( $_array['y'] ) ) $this->_config['y'] = $_array['y'];
			if ( isset( $_array['w'] ) ) $this->_config['w'] = $_array['w'];
			if ( isset( $_array['h'] ) ) $this->_config['h'] = $_array['h'];
			if ( isset( $_array['f'] ) ) $this->_config['f'] = $_array['f'];
		}
		return self::$_instance;
	}