     result.vx = -cos(t * timeStretch);
     result.vy = sin(t * timeStretch);
 
-    stop after a quarter circle
+    // stop after a quarter circle
     if (result.vy < 0)
     {
         result.finished = true;

    result.vx = -1;
    result.vy = 0;

    // todo: time>16

    return result;
}

    result.vx = 0;
    result.vy = 1;

    // stop after a quarter circle
    if (t > 16.0)
    {
        result.finished = true;
    }

    return result;
}
