碰撞检测blabla

记录，怕找不到了~

1:像素碰撞 http://blog.youkuaiyun.com/aa294194253/article/details/38701893

http://blog.youkuaiyun.com/pj933/article/details/38424795

http://blog.youkuaiyun.com/lihaifei_/article/details/38496695

2:点是否在多边形内

  http://www.cnblogs.com/hhyypp/archive/2011/12/05/2276984.html