/* BAD! */
float getTimeDelta()
{
    static unsigned int lastTime = 0;
    unsigned int currentTime = GetTickCount();
    unsigned int timeDelta = currentTime - lastTime;
    lastTime = currentTime;
    return (float)timeDelta * 0.001f;
}

/* GOOD ! */
float getTimeDelta()
{
    unsigned int timeDelta;
    static unsigned int lastTime = 0;
    unsigned int currentTime = GetTickCount();
    if(currentTime >= lastTime)
        timeDelta = currentTime - lastTime;
    else
        timeDelta = (0xFFFFFFFF - lastTime) + currentTime + 1;

    lastTime = currentTime;
    return (float)timeDelta * 0.001f;
}