(function (factory) {
    if ( typeof define === 'function' && define.amd ) {
        define(['jquery'], factory);
    } else if (typeof exports === 'object') {
        module.exports = factory;
    } else {
        factory(jquery);
    }
}(function ($) {
    var tofix  = ['wheel', 'mousewheel', 'dommousescroll', 'mozmousepixelscroll'],
        tobind = ( 'onwheel' in document || document.documentmode >= 9 ) ?
                    ['wheel'] : ['mousewheel', 'dommousescroll', 'mozmousepixelscroll'],
        slice  = array.prototype.slice,
        nulllowestdeltatimeout, lowestdelta;

    if ( $.event.fixhooks ) {
        for ( var i = tofix.length; i; ) {
            $.event.fixhooks[ tofix[--i] ] = $.event.mousehooks;
        }
    }
    var special = $.event.special.mousewheel = {
        version: '3.1.9',
        setup: function() {
            if ( this.addeventlistener ) {
                for ( var i = tobind.length; i; ) {
                    this.addeventlistener( tobind[--i], handler, false );
                }
            } else {
                this.onmousewheel = handler;
            }
            $.data(this, 'mousewheel-line-height', special.getlineheight(this));
            $.data(this, 'mousewheel-page-height', special.getpageheight(this));
        },
        teardown: function() {
            if ( this.removeeventlistener ) {
                for ( var i = tobind.length; i; ) {
                    this.removeeventlistener( tobind[--i], handler, false );
                }
            } else {
                this.onmousewheel = null;
            }
        },
        getlineheight: function(elem) {
            return parseint($(elem)['offsetparent' in $.fn ? 'offsetparent' : 'parent']().css('fontsize'), 10);
        },

        getpageheight: function(elem) {
            return $(elem).height();
        },

        settings: {
            adjustolddeltas: true
        }
    };
    $.fn.extend({
        mousewheel: function(fn) {
            return fn ? this.bind('mousewheel', fn) : this.trigger('mousewheel');
        },
        unmousewheel: function(fn) {
            return this.unbind('mousewheel', fn);
        }
    });
    function handler(event) {
        var orgevent   = event || window.event,
            args       = slice.call(arguments, 1),
            delta      = 0,
            deltax     = 0,
            deltay     = 0,
            absdelta   = 0;
        event = $.event.fix(orgevent);
        event.type = 'mousewheel';
        if ( 'detail'      in orgevent ) { deltay = orgevent.detail * -1;      }
        if ( 'wheeldelta'  in orgevent ) { deltay = orgevent.wheeldelta;       }
        if ( 'wheeldeltay' in orgevent ) { deltay = orgevent.wheeldeltay;      }
        if ( 'wheeldeltax' in orgevent ) { deltax = orgevent.wheeldeltax * -1; }
        if ( 'axis' in orgevent && orgevent.axis === orgevent.horizontal_axis ) {
            deltax = deltay * -1;
            deltay = 0;
        }
        delta = deltay === 0 ? deltax : deltay;
        if ( 'deltay' in orgevent ) {
            deltay = orgevent.deltay * -1;
            delta  = deltay;
        }
        if ( 'deltax' in orgevent ) {
            deltax = orgevent.deltax;
            if ( deltay === 0 ) { delta  = deltax * -1; }
        }
        if ( deltay === 0 && deltax === 0 ) { return; }
        if ( orgevent.deltamode === 1 ) {
            var lineheight = $.data(this, 'mousewheel-line-height');
            delta  *= lineheight;
            deltay *= lineheight;
            deltax *= lineheight;
        } else if ( orgevent.deltamode === 2 ) {
            var pageheight = $.data(this, 'mousewheel-page-height');
            delta  *= pageheight;
            deltay *= pageheight;
            deltax *= pageheight;
        }

        // store lowest absolute delta to normalize the delta values
        absdelta = math.max( math.abs(deltay), math.abs(deltax) );

        if ( !lowestdelta || absdelta < lowestdelta ) {
            lowestdelta = absdelta;

            // adjust older deltas if necessary
            if ( shouldadjustolddeltas(orgevent, absdelta) ) {
                lowestdelta /= 40;
            }
        }

        // adjust older deltas if necessary
        if ( shouldadjustolddeltas(orgevent, absdelta) ) {
            // divide all the things by 40!
            delta  /= 40;
            deltax /= 40;
            deltay /= 40;
        }

        // get a whole, normalized value for the deltas
        delta  = math[ delta  >= 1 ? 'floor' : 'ceil' ](delta  / lowestdelta);
        deltax = math[ deltax >= 1 ? 'floor' : 'ceil' ](deltax / lowestdelta);
        deltay = math[ deltay >= 1 ? 'floor' : 'ceil' ](deltay / lowestdelta);

        // add information to the event object
        event.deltax = deltax;
        event.deltay = deltay;
        event.deltafactor = lowestdelta;
        event.deltamode = 0;
        args.unshift(event, delta, deltax, deltay);
        if (nulllowestdeltatimeout) { cleartimeout(nulllowestdeltatimeout); }
        nulllowestdeltatimeout = settimeout(nulllowestdelta, 200);

        return ($.event.dispatch || $.event.handle).apply(this, args);
    }

    function nulllowestdelta() {
        lowestdelta = null;
    }

    function shouldadjustolddeltas(orgevent, absdelta) {
        return special.settings.adjustolddeltas && orgevent.type === 'mousewheel' && absdelta % 120 === 0;
    }

}));