Normalize scroll

normalizeScroll.js

// Provide "originalEvent" of DOMMouseScroll and mousewheel

var o = event;
var d = o.detail;
var w = o.wheelDelta || o.deltaY;
var n = 225;
var n1 = n - 1;

var d = (d ? (w && (f = w / d) ? d / f : -d / 1.35) : w / 120);
var d = (d < 1 ? (d < -1 ? (-Math.pow(d, 2) - n1) / n : d) : (Math.pow(d, 2) + n1) / n);
event.delta = Math.min(Math.max(d / 2, -1), 1);

return event;