Hi all - Here's a new set of patches for the WM spec adding synchronization. It's a fairly minor evolution of the proposal I made in 2011, with quite a bit more non-normative text added to explain what is going on.
A formatted version of the synchronization chapter can be found at: http://fishsoup.net/misc/wm-spec-synchronization.html For easier review. I'm expecting people to be a bit put off by the complexity of the proposal, and in particular, by the fact that a particular frame timing algorithm is recommended (but not required) for the compositor. I'd certainly rather avoid that, but I found that without some idea of how the compositor is drawing, it is very hard to write a client that achieves a solid, consistent, and known latency. (Something that you want when attempting to play video with perfect audio synchronization.) Additional information on the question of timing can can be found: http://blog.fishsoup.net/2012/11/28/avoiding-jitter-in-composited-frame-display/ (See older blog posts for more general background.) My branches implementing the proposal for GTK+ and GNOME http://git.gnome.org/browse/cogl/log/?h=wip/frame-synchronization http://git.gnome.org/browse/clutter/log/?h=wip/frame-synchronization http://git.gnome.org/browse/mutter/log/?h=wip/frame-synchronization http://git.gnome.org/browse/gtk+/log/?h=wip/frame-synchronization (The GTK+ changes are big because I'm introducing the idea of frame-based drawing from scratch - I'd expect changes for a frame based toolkit like SDL to be much smaller.) The one thing from the spec that is unimplemented in the above patchsets is _NET_WM_SYNC_FENCES - I'll be locating the right hardware/software for a test environment and working on that soon. Please let me know if you have any questions, and if anybody is interested in implementing this for a different window manager or toolkit, I'd be happy to provide advice and work with you on testing for interoperability. - Owen _______________________________________________ wm-spec-list mailing list wm-spec-list@gnome.org https://mail.gnome.org/mailman/listinfo/wm-spec-list
