SuperMap.WindowsPhone.Core.GeoRegionClip.ClipRing C# (CSharp) Méthode

        private static Point2DCollection ClipRing(Point2DCollection ring, Edge edge)
        {
            if ((ring == null) || (ring.Count < 2))
            {
                return null;
            }
            Point2DCollection points = new Point2DCollection();
            Point2D lastPoint = ring[ring.Count - 1];
            for (int i = 0; i < ring.Count; i++)
            {
                Point2D point = ring[i];
                if (Inside(point, edge))
                {
                    if (Inside(lastPoint, edge))
                    {
                        points.Add(point);
                    }
                    else
                    {
                        Point2D item = EdgeIntersection(lastPoint, point, edge);
                        points.Add(item);
                        points.Add(point);
                    }
                }
                else if (Inside(lastPoint, edge))
                {
                    Point2D item = EdgeIntersection(lastPoint, point, edge);
                    points.Add(item);
                }
                lastPoint = point;
            }
            return points;
        }