wl_output ambiguity, xdg_shell fullscreen refresh rate

[Pekka Paalanen]

On Mon, 15 May 2017 12:19:47 +0200
Philipp Zabel <p.zabel at pengutronix.de> wrote:

> On Mon, 2017-05-15 at 11:18 +0300, Pekka Paalanen wrote:
> > On Sun, 14 May 2017 14:43:44 +0200
> > Philipp Kerling <pkerling at casix.org> wrote:
> >   
> > >    quite a problem. I can see that zxdg_toplevel functionality is
> > >    mostly superior to that of wl_shell_surface, but it has one omission
> > >    that is crucial for Kodi: the ability to request a specific refresh
> > >    rate for fullscreen display. This is needed for closely matching the
> > >    display and video FPS so duplicated and skipped frames are kept to a
> > >    minimum. Is this an intentional omission and/or is there anything
> > >    that provides this functionality?  
> > 
> > Hopefully the xdg_shell designers would answer that, but I believe it
> > has been omitted for now to make it easier to declare the first
> > fundamental parts of xdg_shell stable. It is missing a lot, but the
> > foundation must agreed upon first before building more on top.  
> 
> Rather than combining the FPS request with fullscreening, wouldn't it be
> better to let applications set FPS as a property of the surface?
> 
> That way the client would make a promise that is is going to update
> surface contents with periodic commits of the specified rate, completely
> independent of the actual output hardware or fullscreen state.
> 
> The server could use that information to choose the best display refresh
> rate even if not in fullscreen mode.

Hi,

that's a pretty good reason to not have it in the xdg_shell fullscreen
request. ;-)

There are lots of this kind of details to consider for every single
feature added, which is why people tend to prefer not adding features
to xdg_shell until the foundation is stabilized, I believe.


Thanks,
pq
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 833 bytes
Desc: OpenPGP digital signature
URL: <https://lists.freedesktop.org/archives/wayland-devel/attachments/20170515/c8163f47/attachment-0001.sig>