scrollDirection.js

$(window).on('mousewheel DOMMouseScroll touchmove', function (e) {

    var direction = (function () {
        var delta,
            compareEvent;
      
        if (e.type ==='touchmove') {
            compareEvent = 'touchmove';
        } else {
            compareEvent = 'DOMMouseScroll';
        }

        delta = e.type === compareEvent ?
                e.originalEvent.detail * -40 :
                e.originalEvent.wheelDelta;

        return delta > 0 ? 0 : 1;
    }());

    if (direction === 1) {
       // scroll down
    }
    if (direction === 0) {
       // scroll up
    }
});