std::list<Entity*> EntityManager::getNearbyEntities(
    const Vector2f &pos,
    float           radius
    )
{
    std::list<Entity*> result;

    for(std::list<Entity*>::iterator iter = m_entities.begin();
        iter != m_entities.end();
        iter++)
    {
        if(*iter)
        {
            if(pos.distanceSquared((*iter)->getPosition()) < radius * radius)
            {
                result.push_back(*iter);
            }
        }
    }

    return result;
}