multi-touch-dev team mailing list archive

[Chase Douglas <chase.douglas@xxxxxxxxxxxxx>]

On Thu, 2010-10-14 at 20:21 +0200, Henrik Rydberg wrote:
> On 10/14/2010 07:48 AM, Peter Hutterer wrote:
> [...]
> > I think there may be a misunderstanding of the "not for you" flag.
> 
> > There are two reasons why this came up. one is that doing so the server
> > doesn't have to cache events indefinitely if there is a sync grab going on.
> > It can flush the events out but mark them as "do not use" (this was the main
> > motivation).
> > The other one is that gesture detection can be performed in parallel in
> > multiple clients. The only benefit you get is deserialization.
> > given the replay case, the event sequence changes from:
> > 
> > [grab] [events to client1] [gesture detection] [replay request] [events to
> > client2] [gesture detection] [action]
> > 
> > to
> > [grab] [ev to client1] [gest det] [replay req] 
> >        [ev to client2] [gest det]             ["use it" event] [action]
> > 
> > (graphic best viewed in monospace or Internet Explorer 2.0 at 640x234 :)
> > 
> > this parallelisation is the only real effect. the "use it" events simply
> > shorten the delivery when a set of events is given the OK for a 
> > client - that client already has the data by then.
> > 
> > note that we haven't actually decided on doing this, because I predict that
> > the details of getting this semantically sound in the server will be quite
> > tricky.
> 
> 
> Thanks for the clarifications, Peter. Perhaps Chase's event list will look more
> attractive if the tentative events are taken out.

Are you suggesting that the event list would cosmetically look better,
or are you potentially advocating for the serial grabbing alternative
mechanism?

-- Chase