The contacts come in untracked, and the current production versions of hid-ntrig do not add tracking. It just uses the first contact from each frame (I think that will be the finger closest to the bottom of the screen, either that or the top) for single touch coordinates.
In your case, I would suggest ignoring the single touch events, they don't add anything useful when you're already parsing the multi touch events. On Tue, Apr 26, 2011 at 12:10:53PM +0200, Henrik Rydberg wrote: > On Fri, Apr 22, 2011 at 10:10:32AM +0200, Paolo Olivo wrote: > > Hello everyone, > > > > I am developing a mt toolkit, which I would like to interface to > > libmtdev. I am using a Dell XT2 and a 3M M2256PW touchscreen on Ubuntu > > 10.10, kernel 2.6.35-28-generic, libmtdev1.1.0. > > > > I started capturing mtdev events, but I found something weird. I don't > > know if they are bugs or it is simply my misunderstanding. > > > > First, using function "mtdev_has_mt_event" on the XT2 and passing > > ABS_MT_SLOT and ABS_MT_TRACKING_ID, in both cases it returns 0, while > > I actually receive ABS_MT_SLOT and ABS_MT_TRACKING_ID events using > > "mtdev_get". 3M is working fine. > > The XT2 is using MT protocol type A, and mtdev is emulating the slot > and tracking values. The mtdev does not alter the actual kernel > device, therefore mtdev_has_mt_event() returns false for the XT2. > > Cheers, > Henrik > > _______________________________________________ > Mailing list: https://launchpad.net/~multi-touch-dev > Post to : [email protected] > Unsubscribe : https://launchpad.net/~multi-touch-dev > More help : https://help.launchpad.net/ListHelp > _______________________________________________ Mailing list: https://launchpad.net/~multi-touch-dev Post to : [email protected] Unsubscribe : https://launchpad.net/~multi-touch-dev More help : https://help.launchpad.net/ListHelp

