Benefits of the New API - Learn OpenGL ES: For Mobile Game and Graphics Development - page 26

public void onSurfaceChanged(GL10 gl, int width, int
height) {
GLES20.glViewport(0, 0, width, height);
}
public void onDrawFrame(GL10 gl) {
GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT |
GLES20.GL_DEPTH_BUFFER_BIT);
}
}
Note In Listing 1-4 , you will see that the sequence of auto-gener-
ated methods for GLES20Renderer class is modified. This shows
the actual sequence in which these methods are called. If you closely
observe these methods, you might wonder what the purpose of
GL10 type for argument gl is. GL10 is a public interface that im-
plements GL . GLES20Renderer class must implement the inher-
ited abstract methods of GLSurfaceView.Renderer interface,
and the methods of this interface use GL10 type for arguments.
After removing all errors and warnings, run the application. A blank, blue colored
OpenGL surface view, similar to Figure 1-20 , will appear.