ObjectArx.net: Spline转弧段技术与参数计算

//==样条曲线转换成多段弧
public void SplineToArcArray(Curve curve, ref Point3dCollection Point3dColl, ref DoubleCollection Bulges){
                        Spline SplineObject = (Spline)curve;                        
                        Polyline p3d = (Polyline)SplineObject.ToPolyline();
                        int NumberSpline = p3d.NumberOfVertices;
                        int k = 1;
                        
                        for (int i = 0; i < NumberSpline-1; i++)
                        {
                            Log.Append("\r\n" + (i).ToString() + "、p3d[" + Convert.ToString(p3d.GetPoint3dAt(i).X) + "," + Convert.ToString(p3d.GetPoint3dAt(i).Y) + "],[" + Convert.ToString(p3d.GetPoint3dAt(i+1).X) + "," + Convert.ToString(p3d.GetPoint3dAt(i+1).Y) + "]\r\n");
                            Point3d OnArc = new Point3d((p3d.GetPoint3dAt(i).X + p3d.GetPoint3dAt(i + 1).X) / 2, (p3d.GetPoint3dAt(i).Y + p3d.GetPoint3dAt(i + 1).Y) / 2,0);
                            OnArc = SplineObject.GetClosestPointTo(OnArc, false);
                            CircularArc3d arc = new CircularArc3d(p3d.GetPoint3dAt(i), OnArc, p3d.GetPoint3dAt(i + 1));
                            
                            Arc _cArc = ConvertToArc(arc);
                            Double _tBulge = GetBulge(_cArc);
                            Point3dColl.Add(_cArc.StartPoint);
                            Point3dColl.Add(_cArc.EndPoint);
                            Bulges.Add(_tBulge);
                            Bulges.Add(_tBulge);
                            Log.Append("\r\n" + (k).ToString() + "、OnArc[" + Convert.ToString(OnArc[0]) + "," + Convert.ToString(OnArc[1]) + "]\r\n");
                            Log.Append("\r\n S[" + Convert.ToString(_cArc.StartPoint[0]) + "," + Convert.ToString(_cArc.StartPoint[1]) + "," + Convert.ToString(_cArc.StartPoint[2]) + "]E[" + Convert.ToString(_cArc.EndPoint[0]) + "," + Convert.ToString(_cArc.EndPoint[1]) + "," + Convert.ToString(_cArc.EndPoint[2]) + "] ");
                            k = k + 1;
                        }
}
//===取出弧的凸度
        public  double GetBulge(Arc pArc)
        {
            double dStartAngle = pArc.StartAngle;
            double dEndAngle = pArc.EndAngle;