Radeon EQAA Anti-Aliasing Support Merged To Mesa 18.2

In addition to the potentially performance-doubling AMD Kaveri fix landing yesterday in Mesa 18.2 Git, also hitting this next version of Mesa is Enhanced Quality Anti-Aliasing (EQAA) support for Radeon GCN graphics processors.

RadeonSI Gallium3D has wired up its Enhanced Quality Anti-Aliasing support. EQAA aims to deliver better quality over multi-sample anti-aliasing (MSAA) by providing more coverage samples per pixel. EQAA should have only slightly higher performance requirements than MSAA but with significant visual quality benefits.

For now this EQAA support can only be toggled by an environment variable, EQAA. The environment variable needs a value of the number of coverage samples, Z samples, and color samples; all delimited by a comma, such as EQAA=8,4,2. This variable/EQAA also only works if the OpenGL application is going to be making use of MSAA.

The code is now in Git for Mesa 18.2, just in time for any habitual Mesa Git users wanting to try it out for their weekend gaming sessions.