Mesa RFC Changes To Help Worms WMD, Tropico 5 & Crookz

In continuation of this morning's article about Valve Planning To Carry Mesa GL Thread Feature On SteamOS, Per-Game Features, it looks like the developers working for Valve on the open-source Linux graphics driver stack are looking to do more in the per-game profile space.

The earlier article was about Valve interested in landing the OpenGL threading dispatch work into their SteamOS Mesa package even if this feature isn't accepted upstream in Mesa. And Valve would also be maintaining a white-list of games where to automatically turn on this experimental Mesa feature for better performance.

Their work in the controversial per-game/app profile space isn't ending with that. For helping other buggy Linux games, they are looking at adding more DRIRC options. Samuel Pitoiset who started out as a Nouveau contributor but is now working for Valve to improve Mesa, sent out a "request for comments" patch series about adding another new capability to driconf and enabling it to fix a few games.

Samuel explained that some (buggy) Linux OpenGL games will create an OpenGL compatibility profile even though they don't end up using those old GL features found in the compatibility profile and not the core profile. But Mesa doesn't support OpenGL 3.1+ compatibility profiles with focusing on just the core profile. These games using the compatibility profile but without any of those older features tend to not work since Mesa's GLSL version is then limited to 130.

With these RFC patches there would be a new force_compat_profile driconf option to appease some of these problematic Linux games. This option and adding the force_compat_profile option for Worms WMD, Crooz - The Big Heist, and Tropico 5 let these games be happy with the Mesa driver stack. This feature needs to be enabled on a per-game basis but not as a default across the board since it could cause issues for other OpenGL compatibility profile applications/games. This workaround also isn't enough for some heavier OpenGL compatibility-profile-using games like Dying Light -- more work is needed there.

Details on Samuel's RFC proposal via this mailing list thread.