Should OpenGL game use UIScreen nativeBounds or bounds for iPhone6 plus?

Question

My game engine currently uses UIScreen bounds for its rendering resolution. On an iPhone6 plus this reports the virtual resolution of 2208x1242.

On the simulator this is also that same resolution as reported by UIScreen nativeBounds.

However, on a real device nativeBounds will be 1920x1080, and I am unsure which to use for correct OpenGL rendering on an iPhone6 plus, and can find no official documentation on it.

Which one is correct?

Answer 1

I can now confirm that on a real device, correct rendering is produced when using the virtual resolution of 2208x1242 reported by [UIScreen bounds].