Up to now with using XWayland for running X11 applications on Wayland, the traditional DDX drivers for the respective hardware (e.g. xf86-video-ati and xf86-video-intel) have had to be modified to support XWayland and they're still hardware-specific. The xf86-video-wlglamor driver provides a means of generic XWayland support with acceleration being routed through GLAMOR for carrying out 2D operations using the GLAMOR library. GLAMOR is what provides for acceleration support on modern Radeon HD graphics cards and can optionally be used for older generations of Radeon GPUs and also the Intel driver.
This new XWayland DDX was published to GitHub and notes, "The ultimate goal is to have only one DDX for Wayland, and this code will probably be integrated to xf86-video-wayland. It works with Xserver 1.14, unlike the current xf86-video-ati and xf86-video-nouveau XWayland branches we can find today. The DDX is based on Glamor and gbm."