public static IEnumerable <VertexData> GetVertexIter(this Curve4Div curve)
        {
            ArrayList <Vector2> m_points   = curve.GetInternalPoints();
            VertexData          vertexData = new VertexData();

            vertexData.command  = VertexCmd.MoveTo;
            vertexData.position = m_points[0];
            yield return(vertexData);

            vertexData.command = VertexCmd.LineTo;
            for (int i = 1; i < m_points.Count; i++)
            {
                vertexData.position = m_points[i];
                yield return(vertexData);
            }

            vertexData.command  = VertexCmd.NoMore;
            vertexData.position = new Vector2();
            yield return(vertexData);
        }