实现二维扫描转换多边形的扫描线算法 　　实现二维连通区域填充的种子填充算法（四连通或八连通） 　　实现二维直线段裁剪的Cohen-Sutherland裁剪算法和中点分割裁剪算法 -Realization of two-dimensional polygon scan conversion algorithm dimensional scan line connected region filled seed filling algorithm (four or eight con