//// TODO: replace this function by creating a delegate in the entity that
//// the factory methods will set to return the entity to the correct pool.
public void ReturnToPool(Entity entityToReturn)
{
if (entityToReturn is Asteroid)
{
asteroidPool.Return(entityToReturn);
}
else if (entityToReturn is Laser)
{
laserPool.Return(entityToReturn);
}
else if (entityToReturn is Planet)
{
planetPool.Return(entityToReturn);
}
else if (entityToReturn is Ship)
{
shipPool.Return(entityToReturn);
}
}