core/src/ons/gesture-detector.js
function getDirection(touch1, touch2) {
    var x = Math.abs(touch1.clientX - touch2.clientX),
        y = Math.abs(touch1.clientY - touch2.clientY);

    if (x >= y) {
      return touch1.clientX - touch2.clientX > 0 ? DIRECTION_LEFT : DIRECTION_RIGHT;
    }
    return touch1.clientY - touch2.clientY > 0 ? DIRECTION_UP : DIRECTION_DOWN;
  }
function getDirection(touch1, touch2) {
    var x = Math.abs(touch1.clientX - touch2.clientX),
        y = Math.abs(touch1.clientY - touch2.clientY);

    if (x >= y) {
      return touch1.clientX - touch2.clientX > 0 ? DIRECTION_LEFT : DIRECTION_RIGHT;
    }
    return touch1.clientY - touch2.clientY > 0 ? DIRECTION_UP : DIRECTION_DOWN;
  }
function getDirection ( touch1 , touch2 ) { var x = Math . abs ( touch1 . clientX - touch2 . clientX ) , y = Math . abs ( touch1 . clientY - touch2 . clientY ) ; if ( x >= y ) { return touch1 . clientX - touch2 . clientX > 0 ? DIRECTION_LEFT : DIRECTION_RIGHT ; } return touch1 . clientY - touch2 . clientY > 0 ? DIRECTION_UP : DIRECTION_DOWN ; }
do a small comparison to get the direction between two touches.
@param {Touch} touch1
@param {Touch} touch2
@return {String} direction matches `DIRECTION_LEFT|RIGHT|UP|DOWN`
do a small comparison to get the direction between two touches .