RadeonSI Gets Support For Enhanced Quality Anti-Aliasing

The RadeonSI Gallium3D driver now has patches available for Enhanced Quality Anti-Aliasing (EQAA) that is also known as Flexible MSAA.

EQAA is designed to deliver better quality anti-aliasing over traditional MSAA with more coverage samples per pixel while keeping the same number of color/depth/stencil samples. The EQAA visual quality is expected to be significant but with only a small performance impact compared to standard MSAA.

Over nine patches, EQAA was wired in for the RadeonSI Gallium3D driver. EQAA should work for all GCN GPUs.

With the patches, EQAA can be enabled via the EQAA environment variable by specifying the number of coverage samples, Z samples, and color samples, e.g. EQAA=8,4,2. When that environment variable is active, EQAA will be used rather than MSAA for OpenGL applications making use of multi-sample anti-aliasing.