This is a (very) rudimentary demonstration of mapping 2D greyscale pressure pad array data to key input and passing it to an X window.
You'll want Docker to run this demo. On Debian Jessie, if you have backports enabled, do
apt-get install docker.io
Then, build the containers in docker/dev and docker/demo:
cd docker/dev
docker build -t dev .
cd ../demo
docker build -t demo .
From there, use the up.sh and down.sh scripts to create/enter and destroy
(respectively) the container. You can pass additional arguments to docker run
via up.sh. For example, to mount a directory with a 3D game,
./up.sh -v /home/user/sauerbraten:/home/dev/sauerbraten
To run the demo, use xwininfo to get the X window ID of the target
application after it's running, then pass that as the first parameter to
demo.py. Then click around to hit the wasd keys. Escape is bound to
Enter; ideally all keyboard input would go to the target window. Beware: this
won't work if a game expects to have focus.