function calculateTouchesDistance(startPoint, endPoint) {
      var diffX = Math.abs(startPoint.x - endPoint.x);
      var diffY = Math.abs(startPoint.y - endPoint.y);

      return Math.round(Math.sqrt(diffX * diffX + diffY * diffY));
    }
Calculate the distance between 2 touches (pinch)
@param {point} startPoint A point object containing x and y co-ordinates
@param {point} endPoint A point object containing x and y co-ordinates
@return int;
@inner