/*! copyright (c) 2013 brandon aaron (http://brandonaaron.net)
 * licensed under the mit license (license.txt).
 *
 * thanks to: http://adomas.org/javascript-mouse-wheel/ for some pointers.
 * thanks to: mathias bank(http://www.mathias-bank.de) for a scope bug fix.
 * thanks to: seamus leahy for adding deltax and deltay
 *
 * version: 3.1.3
 *
 * requires: 1.2.2+
 */

(function (factory) {
    if ( typeof define === 'function' && define.amd ) {
        // amd. register as an anonymous module.
        define(['jquery'], factory);
    } else if (typeof exports === 'object') {
        // node/commonjs style for browserify
        module.exports = factory;
    } else {
        // browser globals
        factory(jquery);
    }
}(function ($) {

    var tofix = ['wheel', 'mousewheel', 'dommousescroll', 'mozmousepixelscroll'];
    var tobind = 'onwheel' in document || document.documentmode >= 9 ? ['wheel'] : ['mousewheel', 'dommousescroll', 'mozmousepixelscroll'];
    var lowestdelta, lowestdeltaxy;

    if ( $.event.fixhooks ) {
        for ( var i = tofix.length; i; ) {
            $.event.fixhooks[ tofix[--i] ] = $.event.mousehooks;
        }
    }

    $.event.special.mousewheel = {
        setup: function() {
            if ( this.addeventlistener ) {
                for ( var i = tobind.length; i; ) {
                    this.addeventlistener( tobind[--i], handler, false );
                }
            } else {
                this.onmousewheel = handler;
            }
        },

        teardown: function() {
            if ( this.removeeventlistener ) {
                for ( var i = tobind.length; i; ) {
                    this.removeeventlistener( tobind[--i], handler, false );
                }
            } else {
                this.onmousewheel = null;
            }
        }
    };

    $.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,
            absdeltaxy = 0,
            fn;
        event = $.event.fix(orgevent);
        event.type = "mousewheel";

        // old school scrollwheel delta
        if ( orgevent.wheeldelta ) { delta = orgevent.wheeldelta; }
        if ( orgevent.detail )     { delta = orgevent.detail * -1; }

        // new school wheel delta (wheel event)
        if ( orgevent.deltay ) {
            deltay = orgevent.deltay * -1;
            delta  = deltay;
        }
        if ( orgevent.deltax ) {
            deltax = orgevent.deltax;
            delta  = deltax * -1;
        }

        // webkit
        if ( orgevent.wheeldeltay !== undefined ) { deltay = orgevent.wheeldeltay; }
        if ( orgevent.wheeldeltax !== undefined ) { deltax = orgevent.wheeldeltax * -1; }

        // look for lowest delta to normalize the delta values
        absdelta = math.abs(delta);
        if ( !lowestdelta || absdelta < lowestdelta ) { lowestdelta = absdelta; }
        absdeltaxy = math.max(math.abs(deltay), math.abs(deltax));
        if ( !lowestdeltaxy || absdeltaxy < lowestdeltaxy ) { lowestdeltaxy = absdeltaxy; }

        // get a whole value for the deltas
        fn = delta > 0 ? 'floor' : 'ceil';
        delta  = math[fn](delta / lowestdelta);
        deltax = math[fn](deltax / lowestdeltaxy);
        deltay = math[fn](deltay / lowestdeltaxy);

        // add event and delta to the front of the arguments
        args.unshift(event, delta, deltax, deltay);

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

}));