计算任意多边形和矩形的交点 //the input rectClip must have been NormalizeRect(). // CRect rectClip(m_ptnOrign, m_ptnPre); // rectClip.NormalizeRect(); void CheckPolygonClip(const vector &polygon, vector &vSidePoints, const CRect& rectClip) { if(polygon.size()<3) //at least three points return; vector vInputPos; vector vOutputPos; vInputPos.resize(polygon.size());