clip clipBottom clipEdge clipLeft clipRight clipTop getCount getPoint getPoints isLinked kSideType m_closed m_rect m_vs1 m_vs2 operator= output PolygonClip

PolygonClip() PolygonClip::PolygonClip ( const Box2d &  rect, bool  closed = true  ) 构造函数 参数 rect 剪裁矩形，必须为规范化的矩形 closed 将要传入的坐标序列是多边形还是折线