Mesa 21.3 Fixes Issue Of Some Games Having Transparency Issues Under Wayland

Landing in time for the imminent Mesa 21.3 feature freeze / code branching is support for the EGL_EXT_present_opaque extension on Wayland. While this EGL extension may not sound too exciting, for some OpenGL games on Wayland it will address some transparency issues.

The issue stems from this issue ticket opened during the summer by game porter Ethan Lee. The issue is around needing an EGL equivalent to VkCompositeAlphaFlagBitsKHR as "we've got a whole lot of games that are unintentionally translucent in Wayland." Portal 2 is among the games as a result having issues under native Wayland.

Intel's Eric Engestrom ended up drafting the EGL_EXT_present_opaque extension for having a new EGL surface attribute to indicate the surface should be presented as opaque and to disregard the alpha channel if present.

Support for this EGL_EXT_present_opaque extension was merged into Mesa on Tuesday ahead of the Mesa 21.3 branching. This paired with SDL2 code since August that allows using the new extension will address the transparency issues seen by some games running under Wayland.

Mesa 21.3 stable should be out around mid-to-late November. There has also been a number of Radeon fixes, last minute Intel driver changes, and other code landing this week.