computeOutputValue( element ) {

		this._value = this._inheritedInput;

		switch ( this._value ) {
			case "row":
				this._process = FlexDirectionPropertyBox_processRow;
				// this._offset = - element._bounds._innerWidth / 2;
				break;

			case "row-reverse":
				this._process = _processRowReverse;
				// this._offset = element._bounds._innerWidth / 2;
				break;

			case "column":
				this._process = FlexDirectionPropertyBox_processColumn;
				// this._offset = element._bounds._innerHeight / 2;
				break;

			case "column-reverse":
				this._process = _processColumnReverse;
				// this._offset = - element._bounds._innerHeight / 2;
				break;
		}

		// also update dependencies
		if( !element._justifyContent._needsUpdate ) element._justifyContent.computeOutputValue( element );
		if( !element._alignItems._needsUpdate ) element._alignItems.computeOutputValue( element );

		this._needsProcess = true;

	}
@param { (element:MeshUIBaseElement) => void} element
@private