Mesa Now Supports S3TC Texture Compression With sRGB Color Components

Since the notorious S3TC patent expired at the end of 2017, this common texture compression implementation for OpenGL has been supported by mainline Mesa. It's now been extended to also support sRGB non-linear color components.

Google/Chromium developer Gurchetan Singh added support for OpenGL EXT_texture_compression_s3tc_srgb support to Mesa: both core Mesa as well as the drivers -- Gallium3D and the i965 classic driver.

Google and Unity developers worked out the EXT_texture_compression_s3tc_srgb back in 2016 for using S3 Texture Compression with sRGB color components. Adding this extension to Mesa ended up being quite trivial at a few lines of code.

This S3TC sRGB support comes just days after Intel landed for sRGB / FP16 support, including the EXT_sRGB_write_control extension. This latest Mesa work will be found in the 19.1 release due out next quarter with the 19.0 branching having occurred last week.