while(!quit)
    {
        prevTime = curTime;
        curTime = timeGetTime();
        deltaTime = curTime - prevTime;
        if(deltaTime > 20)
            deltaTime = 17;
        timestep = deltaTime/freq;

        while(SDL_PollEvent(&bah))
        {
            if(bah.type == SDL_QUIT || (bah.type == SDL_KEYDOWN && bah.key.keysym.sym == SDLK_ESCAPE))
            {
                quit = true;
            }
        }

        ....
        ....

    }