As an update for anyone who is like me and using Windows 10 and a PS4 controller with DS4Windows and the Xinput Plus program above, and is still having a hard time figuring out why you can't seem to map the buttons on the controller, then here is why.
At least for me, unlike other people on the internet, when I click the box, it doesn't add the little flashing underscore and it doesn't take any inputs for the buttons to add them.
But double clicking the box seems to add the mouse button that you just pressed.
After deciding to just see if I could force it to take by doing a brute force tactic with holding the button on the controller while clicking, I found out that this is the way you're supposed to do it.
Again though, at least for me on the GOG version of this game.
I can only assume it may work as well for other controllers such as an official Xbox controller and such.
So to put it simply for all you new people out there coming across this post to try and get an answer to how to get a controller like the Xbox 360 controller to work and how to assign the inputs, simply follow the guide above to get Xinput Plus set up, then when going to assign buttons in the settings of the game, simply hold down the button on the controller, then double click the slot to assign it. And that's all there is to it.
Unfortunately for me however, it seems as though the camera stick is wonky and only works moving from left to right and doesn't give a crap about up and down. Also, whenever I use the look button to go into first person mode, even though I changed the settings accordingly in Xinput Plus, it goes first person and looks straight up and I can't move it around. (I am referring to the trigger since this is what I've designated as the look button. and I am referring to the settings that is supposed to be changed to make the trigger act as Dinput rather than Xinput)
Camera being weird also happens with any other camera button option I have assigned such as alternate view and such.
So if there's anyone who can give me some insight into what I have to fiddle with to get that working that would be great.
For the time being though, I can still play the game with the camera auto following my character which is playable enough when using a controller..... for now.
Post edited May 21, 2019 by xSimply1337x