How can i clip a rectangle without close?

[jim-jiang-github]

This is a simple code:

static void Main(string[] args)
 {
     Console.WriteLine("Hello, World!");
     PointD[] pointDs = new PointD[]
     {
         new PointD(200,1000),
         new PointD(3200,1000),
         new PointD(3000,600),
         new PointD(200,600),
     };
     PathsD psd = new PathsD();
     psd.Add(new PathD(pointDs));
     Point startPoint = new Point(0, 0);
     double width = 15000;
     double height = 1520;
     int split = 500;
     SvgWriter svg = new(FillRule.NonZero);

     for (int i = 0; i < (int)(width / split); i++)
     {
         var startX = i * split;
         var endX = split * i + split;
         RectD clipRect = new RectD(Math.Max(0, startX - 2), 0, endX, height);
         PathsD paths = Clipper.RectClip(clipRect, psd, 8);
         SvgUtils.AddSubject(svg, paths);
     }
     svg.SaveToFile("rectclip.svg");
 }

I want split a rectangle, I use 'Clipper.RectClip', but a got mutiple rectange splited with closed. How can I splite rectangle without close??

I also try use "Clipper.RectClipLines" but still got wrong result:

static void Main(string[] args)
{
    Console.WriteLine("Hello, World!");
    PointD[] pointDs = new PointD[]
    {
        new PointD(200,1000),
        new PointD(3300,1000),
        new PointD(3300,600),
        new PointD(200,600),
    };
    PathsD psd = new PathsD();
    psd.Add(new PathD(pointDs));
    Point startPoint = new Point(0, 0);
    double width = 15000;
    double height = 1520;
    int split = 500;
    SvgWriter svg = new(FillRule.NonZero);

    for (int i = 0; i < (int)(width / split); i++)
    {
        var startX = i * split;
        var endX = split * i + split;
        RectD clipRect = new RectD(Math.Max(0, startX - 2), 0, endX, height);
        PathsD paths = Clipper.RectClipLines(clipRect, psd);
        SvgUtils.AddSubject(svg, paths);
    }
    svg.SaveToFile("rectclip.svg");
}

[brunnerant]

I would also like to do the same with general polygons, as explained in my question, but I didn't manage to do it either...