Topic: Out, Out, Out or: Get the Viewport UCS

[kaefer]

Viewport.GetUcs doesn't do what it's advertised to do, as in "This function returns the origin, x-axis, and y-axis of the ucs for this viewport."
Googling brought up a link from China four years old:http://www.objectarx.net/forum.php?mod=viewthread&tid=340&page=1

Are there more sleeping beauties?

Code: [Select]

    public static class AcDbViewport
    {
        // Acad::ErrorStatus getUcs(AcGePoint3d& origin, AcGeVector3d& xAxis, AcGeVector3d& yAxis) const;
        [DllImport("acdb18.dll", CallingConvention = CallingConvention.ThisCall, CharSet = CharSet.Unicode,
            EntryPoint = "?getUcs@AcDbViewport@@QBE?AW4ErrorStatus@Acad@@AAVAcGePoint3d@@AAVAcGeVector3d@@1@Z")]

        public static extern ErrorStatus getUcs(IntPtr viewport, out Point3d origin, out Vector3d xAxis, out Vector3d yAxis);

        [CommandMethod("getUCSTest")]
        public static void getUCSTest()
        {
            Document doc = Application.DocumentManager.MdiActiveDocument;
            PromptEntityOptions peo = new PromptEntityOptions("\nSelect viewport: ");
            peo.SetRejectMessage("\nOnly Viewport accepted. ");
            peo.AddAllowedClass(typeof(Viewport), true);
            PromptEntityResult per = doc.Editor.GetEntity(peo);
            if (per.Status == PromptStatus.OK)
            {
                using (Transaction tr = doc.Database.TransactionManager.StartTransaction())
                {
                    Viewport vp = (Viewport)per.ObjectId.GetObject(OpenMode.ForRead);
                    Point3d origin;
                    Vector3d x, y;
                    // vp.GetUcs<Ctrl-Space>: void Viewport.GetUcs(Point3d origin, Vector3d x, Vector3d y)
                    getUcs(vp.UnmanagedObject, out origin, out x, out y);
                    doc.Editor.WriteMessage("Ucs Origin: {0}\nUcs X: {1}\nUcs Y: {2}\n", origin, x, y);
                    tr.Commit();
                }
            }
        }
    }
The easy cure is a little p/invoken. Alas, I can't get it to work under F#2.0 when byref<System.ValueType> is involved.

Regards, Thorsten