hardcoded coords in SimplePool sample code

In the SimplePool sample code, the coordinates for all the objects to be displayed are hardcoded- the side bumpers, etc.

Yet, on every device the pool table looks pretty good- centered on the screen, scaled to the correct size, etc.

Can anyone explain how this works?
[import]uid: 9562 topic_id: 3057 reply_id: 303057[/import]