C#picturebox生成科赫曲线

private void DrawKoch(Graphics g, PointF p1, PointF p2, int n)
{
    if (n == 0)
    {
        g.DrawLine(Pens.Black, p1, p2);
    }
    else
    {
        float dx = (p2.X - p1.X) / 3;
        float dy = (p2.Y - p1.Y) / 3;
        PointF pA = new PointF(p1.X + dx, p1.Y + dy);
        PointF pB = new PointF(p2.X - dx, p2.Y - dy);
        float angle = (float)Math.PI / 3;
        float x = pB.X - pA.X;
        float y = pB.Y - pA.Y;
        PointF pC = new PointF(pA.X + x * (float)Math.Cos(angle) + y * (float)Math.Sin(angle),                               pA.Y - x * (float)Math.Sin(angle) + y * (float)Math.Cos(angle));
        DrawKoch(g, p1, pA, n - 1);
        DrawKoch(g, pA, pC, n - 1);
        DrawKoch(g, pC, pB, n - 1);
        DrawKoch(g, pB, p2, n - 1);
    }
}

private void pictureBox1_Paint(object sender, PaintEventArgs e)
{
    Graphics g = e.Graphics;
    PointF p1 = new PointF(50,200);
    PointF p2 = new PointF(550, 200);
    DrawKoch(g, p1, p2, 5);
}

// 在PictureBox上绘制科赫曲线

--相关问题--:
1. C#中如何实现图片的裁剪和旋转？
2. 如何在C#