sprite rotation demo

demonstrate usage of currentTransform.rotate

HTML

<script src="https://github.com/melonjs/melonJS/releases/download/4.0.0/melonJS.js"></script>
<!-- Canvas placeholder -->
<div id="screen"></div>

JavaScript

<!-- init the melonJS Library -->
me.boot();

<!-- game template -->
var game = {

    // assets to preload
    assets: [{
        name: "logo",
        type: "image",
        src: "http://superpowers-html5.com/images/superpowers-logo.png"
    }],


    // Run on page load.
    "onload": function() {
        // Initialize the video.
        if (!me.video.init(960, 640, {
                wrapper: "screen",
                scale: "auto"
            })) {
            alert("Your browser does not support HTML5 canvas.");
            return;
        }

        // Initialize the audio.
        me.audio.init("mp3,ogg");

        // set and load all resources.
        // (this will also automatically switch to the loading screen)
        me.loader.preload(game.assets, this.loaded.bind(this));
    },

    // Run on game resources loaded.
    "loaded": function() {
        var PlayScreen = me.ScreenObject.extend({
            // on reset event function
            onResetEvent: function() {
                // black background
                me.game.world.addChild(new me.ColorLayer("background", "#202020"), 0);
                var logo = new game.LogoEntity(345, 170,"logo");
                me.game.world.addChild(logo, 1);
                var maxAngle = 5;
                var tween = new me.Tween(logo).to( {x:200, currentAngle:maxAngle}, 8000 ).onUpdate(function (val){console.log( logo.currentAngle,val*maxAngle,(1-val)*maxAngle)}).easing(me.Tween.Easing.Quadratic.InOut).repeat(Infinity).yoyo(true).start(); 
            }
        });

        // set the "Play/Ingame" Screen Object
        me.state.set(me.state.PLAY, new PlayScreen());
        // switch to PLAY state
        me.state.change(me.state.PLAY);
    }
};

/**
 * a basic sprite object
 */
game.LogoEntity = me.Entity.extend({
    init: function(x, y, imageName) {
    		var image = me.loader.getImage("logo"); 
        // call the super constructor
        this._super(me.Entity, "init", [x, y, {
            width:...