public void onSurfaceChanged(GL10 glUnused, int width, int height)
{
// Set the OpenGL viewport to the same size as the surface.
gl.viewport(0, 0, width, height);
// Create a new perspective projection matrix. The height will stay the same
// while the width will vary as per aspect ratio.
float ratio = (float)width / height;
float left = -ratio;
float right = ratio;
float bottom = -1.0f;
float top = 1.0f;
float near = 1.0f;
float far = 10.0f;
Matrix.frustumM(mProjectionMatrix, 0, left, right, bottom, top, near, far);
}