chuck.js/app/Game/Core/Physics/Engine.js

define([
    "Game/Config/Settings",
    "Lib/Vendor/Box2D",
    "Game/Core/Collision/Detector"
],

function (Settings, Box2D, CollisionDetector) {

    function Engine () {
        this.world = new Box2D.Dynamics.b2World(
            new Box2D.Common.Math.b2Vec2(0, Settings.BOX2D_GRAVITY),
            Settings.BOX2D_ALLOW_SLEEP
        );
    }

    Engine.prototype.getWorld = function () {
        return this.world;
    }

    Engine.prototype.setCollisionDetector = function (me) {
        
        var detector = new CollisionDetector(me); // FIXME: check if core collision detector works
        this.world.SetContactListener(detector.getListener());
    }

    Engine.prototype.createBody = function (bodyDef) {
        return this.world.CreateBody(bodyDef);
    }

    Engine.prototype.update = function () {
        this.world.Step(Settings.BOX2D_TIME_STEP, Settings.BOX2D_VELOCITY_ITERATIONS, Settings.BOX2D_POSITION_ITERATIONS);
        this.world.ClearForces();
    }

    return Engine;
});