CSharpGL.Scene.Pick C# (CSharp) Method

        public List<Tuple<Point, PickedGeometry>> Pick(Point mousePosition, PickingGeometryType pickingGeometryType)
        {
            Rectangle clientRectangle = this.Canvas.ClientRectangle;
            // if mouse is out of window's area, nothing picked.
            if (mousePosition.X < 0 || clientRectangle.Width <= mousePosition.X || mousePosition.Y < 0 || clientRectangle.Height <= mousePosition.Y) { return null; }

            int x = mousePosition.X;
            int y = clientRectangle.Height - mousePosition.Y - 1;
            // now (x, y) is in OpenGL's window cooridnate system.
            Point position = new Point(x, y);
            var pickingRect = new Rectangle(x, y, 1, 1);
            List<Tuple<Point, PickedGeometry>> allPickedGeometrys = null;
            foreach (ViewPort viewPort in this.rootViewPort.Traverse(TraverseOrder.Post))
            {
                if (viewPort.Visiable && viewPort.Enabled && viewPort.Contains(position))
                {
                    allPickedGeometrys = ColorCodedPicking(viewPort, pickingRect, clientRectangle, pickingGeometryType);

                    break;
                }
            }

            return allPickedGeometrys;
        }