multi-touch-dev team mailing list archive

[Henrik Rydberg <rydberg@xxxxxxxxxxx>]

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.

Cheers,
Henrik