BUG:
Caused by: java.lang.IllegalStateException: setRenderer has already been called for this instance.
或者NullPointer错误
解决方法：
把setEGLContextClientVersion(2);挪到setRenderer()前面。方法的注释上写到“If this method is called, it must be called before
setRenderer(Renderer) is called.
”。
拓展：
并且setRender（）之后之前的方法调用顺序，也是固定。详情可以看代码注释，如下：
This method should be called once and only once in the life-cycle of a GLSurfaceView.
（这些方法只能在CLSurfaceView中有且只能调用一次）
The following GLSurfaceView methods can only be called before setRenderer is called:
（setRender前调用，当然也包括setEGLContextClientVersion(2)）
setEGLConfigChooser(boolean) setEGLConfigChooser(EGLConfigChooser)
setEGLConfigChooser(int, int, int, int, int, int)
The following GLSurfaceView methods can only be called after setRenderer is called:
（setRender后调用）
OpenGL,Android注意事项初始化顺序 NullPointer
原文地址：http://blog.csdn.net/zhjali123/article/details/41856181
