Multi-touch Protocol B Slots

[kev]

Hello,

Are the Linux defined (Multi-touch-protocol.txt) Protocol B Slots used
in Gingerbread or Honeycomb?

Thank you,
-kev

[Jeffrey Brown]

Not at this time.  Out current drivers do not use the ABS_MT_SLOT protocol and I ran out of time to implement it for Honeycomb.

Support for this feature could be contributed via AOSP.  Or I may just get around to it later.

One tricky bit is that even if the MultiTouchInputReader class in InputReader.cpp were modified to support ABS_MT_SLOT, applications still expect motion events to contain information about *all* pointers, not just the ones that changed.  So the bandwidth from kernel to userspace would be reduced slightly but all of the real heavyweight work dispatching the event to applications would be unchanged.

Basically, there is no benefit supporting ABS_MT_SLOT other than to obtain compatibility with newer drivers.

Jeff.

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[kev]

Hi Jeff,

Thank you for the information.

We are trying to get our touchscreen driver into an open source repository.  However, the Linux community will not accept our driver for submission without Protocol B.  Can we submit our driver for inclusion in the Android repository?  It will use Track ID's for multi-touch.

Thanks and best regards,
-kev

[Heiko Lechner]

What about android's finger tracking? Protocol B could release the system from that burden (assuming the touch hardware can track the fingers)

Am 25.02.2011 08:35 schrieb "Jeffrey Brown" <jeff...@android.com>:
Not at this time.  Out current drivers do not use the ABS_MT_SLOT protocol and I ran out of time to implement it for Honeycomb.

Support for this feature could be contributed via AOSP.  Or I may just get around to it later.

One tricky bit is that even if the MultiTouchInputReader class in InputReader.cpp were modified to support ABS_MT_SLOT, applications still expect motion events to contain information about *all* pointers, not just the ones that changed.  So the bandwidth from kernel to userspace would be reduced slightly but all of the real heavyweight work dispatching the event to applications would be unchanged.

Basically, there is no benefit supporting ABS_MT_SLOT other than to obtain compatibility with newer drivers.

Jeff.

On Tue, Feb 22, 2011 at 1:10 PM, kev <mcnee...@gmail.com> wrote:
>
> Hello,
>

> Are the Linux d...

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