Oh, someone else mad enough to compile it on Linux
I guess you want to make an AUR package for the game? As mentioned by richard it's probably not worth it because even if you manage to compile it you will still need to copy some files over from the binary release to make it work, and the game will still complain that it's not an official build. But as far as I'm aware joining public servers is actually possible. So if an AUR package is your goal, your best bet would be making a bin package that just extracts the binary release and has all necessary dependencies.
But even that will be not great, because the Linux client has a lot of issues. Sound will not work, unless you launch it with "+snd_driver sdl" as command line argument and restart the game, because the default sound driver uses OSS which has been removed from Linux for ages. And once you got the sound working, you will notice a load of other issues related to mouse and keyboard input. Mouse is jittery, the game steals *all* keyboard input (if you're using X11), enabling fullscreen messes up multimonitor setups, and so on.
If all you want to do is play the game, install lutris and use its install script for the game (
https://lutris.net/games/digital-paintball-2/) to install the Windows version with Wine. It works much much better, and I try to keep the install scripts updated.
Anyway, if you really want to compile the linux build, your best bet is breaking into jitspoes house and stealing his old Laptop which has Ubuntu 10 or something with all obscure dependencies installed.
Your second best bet is using this docker image that I made a while ago specifically to compile the game:
https://hub.docker.com/r/nukla/dp2compile. It can pull the latest code from the SVN repository that was already mentioned here. And it is based on 32 bit Ubuntu 16.04 and has all dependencies necessary to compile the game preinstalled. More specifically, it has these packages installed on top of Ubuntu 16.04 (you can also find it in the
Dockerfile):
subversion
build-essential
libsdl1.2-dev
libjpeg62-dev
libasound2-dev
ca-certificates
This list might be useful for your third best bet: compiling it manually. I only ever managed to do it on old 32 bit Ubuntu versions, but maybe I should give it another try on Arch someday.
Keep in mind that the Linux build can break at any time when new code is pushed, it is very fragile and mostly only tested on Windows.