Marek Begins Working On Possible OpenGL Compatibility Profile For Mesa

Well known open-source AMD graphics driver developer Marek Olšák has sent out patches offering ARB_compatibility support with OpenGL 3.1.

The ARB_compatibility extension when introduced in OpenGL 3.1 is for indicating the deprecated/removed features from core OpenGL are still available. Marek wrote this weekend on Mesa-dev:

This shouldn't be a surprise to some of you. Let's say this is a new trend in Mesa.

OpenGL 3.1 with ARB_compatibility is tiny since most of the work was done a long time ago.

This is not really a Compatibility profile because the first Compatibility profile starts at OpenGL 3.2, but it's fundamentally the same thing.

As far as the importance of the OpenGL compatibility profile support, it's mostly a function for workstation users. There's a lot of OpenGL-using workstation/professional applications sadly relying upon the OpenGL compatibility context for using legacy GL bits with newer versions of the OpenGL API. This has been among the expressed lead reasons why AMD is still maintaining their closed-source OpenGL driver in AMDGPU-PRO rather than focusing on AMDGPU+RadeonSI for all use-cases.

More on OpenGL ARB_compatibility via the OpenGL Wiki.

The OpenGL 3.1 ARB_compatibility patches are quite small. It will be interesting to see where the work leads from here and if AMD really is pursing full-on (OpenGL 3.2+) compatibility profile support to possibly push off workstation customers onto the RadeonSI Gallium3D driver in the future.