Landscape + full key support

The game now renders in landscape, with the buttons on the right-hand side! This means it renders at 800x600 instead of 600x800, which makes much more sense 😄

Also, the flickering of the UI was fixed, the game looks much better!

Finally, the key handling code was fixed and the game can now use all the buttons on the Kindle, allowing you to open doors and access the menus. It is now (theoretically) possible to finish the game!

Proof-of-concept

This is the first version of PrBoom for the Kindle 4.

This KUAL extension automatically stops the Kindle interface before running the game, and starts it back up afterwards.

You can't open the first door yet!