How to draw on 2D plane?

.Net Add-on Programming
1

I’m trying to use 2D plane for my own things, but I was totally lost in making a single line. I found how to switch to 2D drawing, found IDrawingView that looking reliable for making any figure, but I don’t understand how to make ILineSet or where I can get objects that realize this interface.

public void draw()
        {
            var context = IoC.Get<IApplicationContext>();
            IoC.Get<IApplication>().DrawingContext = true;            
            ISimWorld drawingWorld = IoC.Get<IApplication>().DrawingWorld;

            \\it works
            IAnnotation ann = drawingWorld.CreateLayoutItem<IAnnotation>("hello");
            ann.Text = "Hello world";

            \\how to make it work?
            IDrawingView line = drawingContext.CreateLayoutItem<IDrawingView>("rect");
            Vector3 topleft = new Vector3(100, 10, 0);
            Vector3 topright = new Vector3(100, 200, 0);
            ???
            rect.SetLines(???);

        }

Tried to make my own realization of ILineSet interface like in the code below, but program tell me, that
"Unhandled exception occurred:EXCEPTION_ACCESS_VIOLATION "

class Rect : ILineSet
        {
            private List<Vector3[]> InternalLines = new List<Vector3[]>();

...

            public ReadOnlyCollection<Vector3[]> Lines
            {
                get {
                    return  InternalLines.AsReadOnly(); 
                } 
            }

...

            public void AddLine(Vector3 point1, Vector3 point2)
            {
               Vector3[] vector = new Vector3[2];
                vector[0] = point1;
                vector[1] = point2;
                InternalLines.Append(vector);
                //Lines.Append<Vector3>(point1);
            }

in draw function

....
            IDrawingView rect = drawingWorld.CreateLayoutItem<IDrawingView>("hello");

            Vector3 topleft = new Vector3(100, 10, 0);
            Vector3 topright = new Vector3(100, 200, 0);

            Rect myRect = new Rect();
            myRect.AddLine(topleft, topright);

            List<ILineSet> liseSet = new List<ILineSet> { myRect };
            IEnumerable<ILineSet> test = liseSet.AsEnumerable<ILineSet>();
            
            rect.SetLines(test);
....
2

I guess the only way to add the sets to the IDrawingView is by using the IHiddenLineService.
You will need to have in the 3D word your plane (a component with a plane geometry) and then use the IHiddenLineService.Create() to get a HiddenLineRepresentation result, that result contains list of LineSets that can be used to populate the drawing element.

3

I see. IDrawingView can’t help me in my goals. In that case, I will try WPF for free drawing.

Thank you for replay