Mesa's Vulkan WSI/Wayland Code Adds "IMMEDIATE" Present Mode Support

Mesa's Vulkan windowing system integration (WSI) code for Wayland has added the "IMMEDIATE" present mode option that uses Wayland's tearing-control unstable extension to allow for images to be presented immediately but at the risk of visible screen tearing.

The VK_PRESENT_MODE_IMMEDIATE_KHR mode is specified by the Vulkan spec as "the presentation engine does not wait for a vertical blanking period to update the current image, meaning this mode may result in visible tearing. No internal queuing of presentation requests is needed, as the requests are applied immediately."

More details on the immediate mode via the Wayland tearing updates protocol.

For nearly one year now has been this Mesa merge request for adding the IMMEDIATE support to the Wayland WSI code. The work was managed by Simon Ser and is now in Mesa Git ahead of the v23.3 release in Q4.