Le 16 août 10 à 15:58, Jiri Kosina a écrit :
thanks for the analysis. How do devices in their report descriptor
describe the fact whether the events should be interleaved by sync
or not?
As far as I know, they don't. I know of two multitouch devices that
send groups of fingers over several HID messages:
- the 3M 22" panel, when there are more than 6 fingers on the
panel. You know there are more messages coming when the number of
fingers (reported through ContactCount in the first message) is
greater than 6.
- the eGalax 72xx series, that adds a second message whenever there
are two fingers; I am not sure yet how one knows when to wait for a
second message. Mathieu might be able to tell us.
The short term solution could be to add a .sync hook similar
to .event. Each specific driver could override the call to input_sync
() based on its knowledge of the device.
We definitely could create a specialized version of
hidinput_report_event() for certain reports, which wouldn't issue the
input_sync() call, but I wonder what is the distinguishing factor.
Yes, for months now I have wondered what the generic multitouch HID
driver in Windows 7 might look like :-) I suspect that we now have a
sufficient sample of devices (about 10 different ones, all claiming
to be Win7 compliant) to extrapolate from their behaviour.
Cheers
St.
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