我们在用OpenGL绘图时往往想制作一些复合图形以及凹凸多边形，像五角星、大的矩形里再画一个小的矩形；另外有时还想做些镂空图或类似的效果。这时我们可以开启模板测试功能来完成。-When we tend to want to use OpenGL graphics to make some complex polygon graphics and irregularities, such as five-pointed star, and then draw a large rectangle in a small rectangle　another may want to do some hollow chart or similar effect. Then we can open the mask test function to complete.