使用OpenGL实现的透明茶壶，其中中间的茶壶是贴了纹理的，周围的茶壶数目由用户确定，且都是透明的，本程序的重点是：茶壶的深度排序以及绘制的顺序。-The use of OpenGL to achieve a transparent teapot, in which the middle of the teapot is posted texture, surrounded by the number of teapot set by the user, and are transparent,