public IComponent Clone()
        {
            PeriodicAddComponentComponent ret = new PeriodicAddComponentComponent();
            ret.ComponentToAdd = ComponentToAdd.Clone();
            ret.Period = Period;
            ret.TimeSinceLastFiring = TimeSinceLastFiring;

            return ret;
        }
        //Note: timerPhaseAngle is expected to be in the interval [0, 1]
        private void createPlayerGun(IEntityManager entityStore, Entity player, Entity bullet, float offsetProportion, float timerPhaseAngle)
        {
            //compute the gun's offset from the player, then create the gun
            AABBComponent bulletBox = (AABBComponent)bullet.components[typeof(AABBComponent)];
            AABBComponent playerBox = (AABBComponent)player.components[typeof(AABBComponent)];
            Entity gun = createPositionSlavedEntity(player, new Vector2(playerBox.Width + 0.1f, playerBox.Height * offsetProportion - bulletBox.Height / 2.0f));

            //The gun now has a position coupled to that of the player
            //So spawn bullets at the gun!
            SpawnEntityComponent spawner = new SpawnEntityComponent();
            spawner.Factory = new ComposedEntityFactory(new List<IEntityFactory>() {
                new CloneEntityFactory(bullet),
                new InheritParentComponentEntityFactory(typeof(PositionComponent)) });

            //Bullets should be spawned periodically
            PeriodicAddComponentComponent timer = new PeriodicAddComponentComponent();
            timer.Period = 200.0f;
            timer.TimeSinceLastFiring = timer.Period * timerPhaseAngle;
            timer.ComponentToAdd = spawner;
            gun.AddComponent(timer);

            //The gun should be removed from the world when the player dies
            DestroyedOnParentDestroyedComponent existentialDependency = new DestroyedOnParentDestroyedComponent();
            existentialDependency.parent = player;
            gun.AddComponent(existentialDependency);

            //finally, add the gun to the world
            entityStore.Add(gun);
        }
        private void initializeMinefield(IEntityManager entityStore, Game game)
        {
            //Create a mine-spawning entity that spawns mines in random positions every once in a while
            Entity minespawner = new Entity();

            //Component: Spawn an entity
            SpawnEntityComponent spawnComponent = new SpawnEntityComponent();
            spawnComponent.Factory = createAsteroidFactory(game);

            //Component: Periodically add a spawn entity component
            PeriodicAddComponentComponent timer = new PeriodicAddComponentComponent();
            timer.ComponentToAdd = spawnComponent;
            timer.Period = 500;
            timer.TimeSinceLastFiring = 0.0f;
            minespawner.AddComponent(timer);

            //Add the minefield to the entity store
            entityStore.Add(minespawner);
        }