onTouchStart( event ) {

		this.touchCaptured = false;

		if( this.isSwipePrevented( event.target ) ) return true;

		this.touchStartX = event.touches[0].clientX;
		this.touchStartY = event.touches[0].clientY;
		this.touchStartCount = event.touches.length;

	}
Handler for the 'touchstart' event, enables support for
swipe and pinch gestures.

@param {object} event