private bool pollEvents()
    {
        static SDL_Event event;

        while (SDL_PollEvent(&event) != 0)
        {
            switch (event.type)
            {
                case SDL_QUIT:
                    return false;
                case SDL_KEYDOWN:
                    if (event.key.keysym.sym == SDLK_F4 &&
                        (event.key.keysym.mod == KMOD_LALT ||
                        event.key.keysym.mod == KMOD_RALT))
                    {
                        SDL_Event e;
                        e.type = SDL_QUIT;
                        SDL_PushEvent(&e);
                    }
                    break;
                default:
            }
        }

        return true;
    }