我现在C#winform中画好的一条曲线，想把一个点在画好的曲线轨迹上做匀速运动。求大仙指教

public MapExample()
  {
      InitializeComponent();

      Timer clock = new Timer();
      clock.Interval =1000;
      clock.Tick += delegate { Invalidate(); };
      clock.Start();
  }

  //重载OnPaint
  protected override void OnPaint(PaintEventArgs e)
  {
      DateTime time = DateTime.Now;
      using (Graphics g = e.Graphics)
      {
          g.DrawEllipse(new Pen(Brushes.Blue, 1), 0, 0, 200, 200);//圈
          g.TranslateTransform(100.0f,100.0f);
          System.Drawing.Drawing2D.GraphicsState state = g.Save();
          g.RotateTransform(time.Second * 6 - 90);//设置旋转的角度
          g.FillEllipse(new SolidBrush(Color.Green), 65, 65, 10, 10);//小点
      }
  }