EXT_external_objects For Mesa Updated, Fixes SteamVR OpenGL Crash

Valve developer Andres Rodriguez has sent out his third revision to the set of Mesa patches implementing the EXT_external_objects OpenGL extension.

EXT_external_objects is for EXT_memory_object and EXT_memory_object_fd for Linux drivers and is similar to the external memory behavior offered on Vulkan. Valve is planning to make use of this OpenGL External memory object support by the SteamVR compositor on Vulkan. This is a newer GL extension likely to be introduced officially with OpenGL 4.6.

This third version of the Mesa patches fix a crash during initialization of the SteamVR OpenGL client. There's also a GFX9/Vega fix and other fixes/clean-ups spurred by code review on the earlier patches.

These latest patches can be found on Mesa-dev. The cut-off for new Mesa 17.2 features is happening next Friday, so let's hope these patches manage to get merged in time to avoid having to wait another quarter before seeing this functionality in a stable Mesa release.