Oh, if you want to use a Steam Controller, then it's easiest to use the following project instead of x360ce:

https://github.com/kozec/dumbxinputemu

That gets the Steam Controller's xbox 360 emulation to be seen by the game as xbox 360 input. Once that's set up, you set up your Steam Controller controls in either (Linux) Steam or sc-controller. And you can actually do it the way you would on Windows: by starting with the pad fully emulating an Xbox 360 controller, changing the right pad to "joystick mouse" (trackpad aiming), adding gyro controls, and adding any additional customizations that are appropriate (setting the left pad to "joystick move" and the stick to D-Pad is pretty common).

I've been working on a Steam/WINE/XInput guide to post. But TBH, I've already posted most of information in it to this thread, so I might not bother.

EDIT: Now I know how to get all that working, I'm switching back to mouse and keyboard controls

Why not write a Slack Docs article using the information you provided in your posts in this thread?

1 members found this post helpful.

I just posted it in the Linux - Gaming forum. You can't miss it.

I don't look there for Slackware information.

I read recently about a recent development in Steam, called Proton, that was supposed to enable Windows games to play on Linux with no issues.

Well, today I found out how true that was. I opted-in to the Beta program, and again attempted to run DOOM. The first time, and every time thereafter, it launched and ran flawlessly. I was able to bash in a few demon skulls, much to my satisfaction. I already marked this thread as solved, but only because I had given up and installed Windows to run DOOM. However, with this new development, I was able to eradicate Windows, and solely run Linux, and *still* run DOOM 2016!! HOORAY!!!!