I have managed to solve the initial compilation problem, and the problem with the glx.h library, now I have problems when it wants to link the game executables
All these problems are with the bullet library, I guess I’ll have to change something in CMake, to solve it, but I’ll keep trying later
Not always, for instance python does the same (python = 2.7, python3 = 3.7 etc …) 
Xlibe does not implement GLX (yet) so you will not be able to use OpenGL on the Xlib compatibility layer, unfortunately.
Well, in the end I was able to compile and run GTA III inside Haiku, I didn’t do it with the OpenRW project, but with the extinct RE3 project.
It runs at less than 1 FPS, and the viewport is bugged, plus I had to do a few tweaks to get it to run, but it works.
Right now it’s late at night, I hope to do more tests tomorrow.
