[PATCH wayland-protocols v2] unstable: Add input-timestamps protocol

Alexandros Frantzis alexandros.frantzis at collabora.com
Wed Dec 20 14:21:32 UTC 2017


On Tue, Dec 19, 2017 at 01:06:11PM +0200, Alexandros Frantzis wrote:
> On Tue, Dec 19, 2017 at 10:15:06AM +0200, Pekka Paalanen wrote:
> > On Mon, 18 Dec 2017 14:55:00 +0200
> > Alexandros Frantzis <alexandros.frantzis at collabora.com> wrote:
> > 
> > > wl_pointer, wl_keyboard and wl_touch events currently use a 32-bit
> > > timestamp with millisecond resolution. In some cases, notably latency
> > > measurements, this resolution is too coarse to be useful.
> > > 
> > > This protocol provides additional high-resolution timestamps events,
> > > which are emitted before the corresponding input event. Each timestamp
> > > event contains a high-resolution, and ideally higher-accuracy, version
> > > of the 'time' argument of the first subsequent supported input event.
> > > 
> > > Clients that care about high-resolution timestamps just need to keep
> > > track of the last timestamp event they receive and associate it with the
> > > next supported input event that arrives.
> > > 
> > > Signed-off-by: Alexandros Frantzis <alexandros.frantzis at collabora.com>
> > > Reviewed-by: Pekka Paalanen <pekka.paalanen at collabora.co.uk>
> > > Acked-by: Jonas Ã…dahl <jadahl at gmail.com>
> > > ---
> > > 
> > > Changes in v2:
> > >  - Add '...carrying a timestamp...' to better describe the set of subsequent
> > >    input events in the timestamp event description. 
> > >  - Clarify normalization requirements of tv_sec_hi, tv_sec_lo, tv_nsec
> > >    timestamp representation.
> > > 
> > >  Makefile.am                                        |   1 +
> > >  unstable/input-timestamps/README                   |   4 +
> > >  .../input-timestamps-unstable-v1.xml               | 145 +++++++++++++++++++++
> > >  3 files changed, 150 insertions(+)
> > >  create mode 100644 unstable/input-timestamps/README
> > >  create mode 100644 unstable/input-timestamps/input-timestamps-unstable-v1.xml
> > 
> > Cool! I suppose we want to see the Weston implementation patches posted
> > to the list before landing this?
> 
> The plan is to refresh and clean up the proof-of-concept Weston
> implementation and propose it. For those interested to take an
> early look the p-o-c code is at:
> 
> https://gitlab.collabora.com/alf/weston/commits/zwp-input-timestamps

Hi all,

a heads-up that I have posted the libweston input-timestamps patchset
for review at:

https://lists.freedesktop.org/archives/wayland-devel/2017-December/036392.html

Thanks,
Alexandros


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