说明：  关于屏幕保护程序在OpenGL里面的实现,小虫的绘制方式采用二维的方法,汇聚过程中保持随机性,用户点一个位置,小虫都向这个位置汇聚
(On the screen saver in the OpenGL inside realize, insect s way of using two-dimensional mapping method, the process of convergence to maintain randomness, the user points a position, bugs are brought together to this location)