clone copy Geometry2D getType mType ~Geometry2D

copy() virtual Geometry2D * copy ( void  ) const pure virtual 在 ArcofCircle2D, ArcofEllipse2D, BezierCurve2D, BSplineCurve2D, Circle2D, Ellipse2D, Hatch2D, Hyperbola2D, Line2D, LineSegment2D, NURBSCurve2D, Parabola2D, Point2D, PolyLine2D , 以及 Curve2D 内被实现.