utils.js

var requestAnimationFrame = (
        window.requestAnimationFrame ||
        window.webkitRequestAnimationFrame ||
        window.mozRequestAnimationFrame ||
        window.oRequestAnimationFrame ||
        function(fn) { return setTimeout(fn, 1000/60); }
    ),
    animationLoop = function next(fn, immediate) {
        immediate && (fn() === false) || requestAnimationFrame(next.bind(null, fn, true));
    };

function debounce(fn, threshhold) {
    threshhold = threshhold || 1000/60;
    var timer;
    return function(){
        var run = fn.apply.bind(fn, this, arguments);
        clearTimeout(timer);
        timer = setTimeout(run, threshhold);
    };
}

function throttle (fn, threshhold) {
    // Wenn threshhold nicht angegeben, mit Bildshirm synchronizieren
    var next = threshhold ? function(fn) { setTimeout(fn, threshhold) } : requestAnimationFrame;

    var waiting = false,
        runAfterWait = false,
        run;
    return function() {
        run = fn.apply.bind(fn, this, arguments);

        if (waiting) {
            runAfterWait = true;
        } else {
            run();
            waiting = true;
            next(function() {
                waiting = false;
                if (runAfterWait) {
                    runAfterWait = false;
                    run();
                }
            });
        }
    };
}

function memoize(fn) {
    var cache = {};
    return function() {
        var key = JSON.stringify(arguments);
        if (!cache.hasOwnProperty(key)) {
            cache[key] = fn.apply(this, arguments);
        }
        return cache[key];
    }
}