New approach to multitouch using DIDs and bitmasked events

[Peter Hutterer]

On Wed, Jul 21, 2010 at 09:27:48AM +0300, Micki Balanga wrote:
> Hi All,
> My name is Micki , I works at N-trig. 
> I am responsible on the Linux development at N-trig. 
> I would like to participle the discussion of adapting multi-touch protocol into Xorg server and share my knowledge regards this issue. 
> I had read the posts and I would like to raise a question: 
> Is there any distinguish between single touch and multi-touch events?

looks like multi-touch events will be following some extra protocol
specification. currently being worked on, no public version available just
yet (too early).

> I think, there are some scenarios need to take into account:
> a. Touching the screen with one finger and then after a while you touch the screen with another finger.

there'll be some pointer emulation code for single-finger interaction that's
likely implementation-specific but detectable by the client (so they can
differ between a MT event and a pointer event).

> b.  Gestures for example zoom , rotate. 

Gestures will not be in the X server but on the client side instead.

> I think that before sending an event to the server, there should be an
> application which handles all touch events and transfer the right message
> to server according to movement type (like Mohamed Ikbel Boulabiar
> suggested) an application which analyze current movement: 
> a single touch or multi –touch movements (more than one finger). 

IMO, single-touch interaction on a multi-touch system is just a subset of
multi-touch interaction and doesn't need special treatment. A client either
uses MT or it doesn't.

> For example: In N-trig we developed gesture engine which analyze the
> current message received from the sensor, analyze the data and transfer it
> as multi-touch events.
> 
> Do you supports that kind of application, is there a set of new multi-touch commands?
> Is there a code I can download for testing to add my feedbacks as well?

not yet, soon-ish.

Cheers,
  Peter