[RFC] Multitouch support, step one

[Ping Cheng]

2010/3/20 Rafi Rubin <rafi at seas.upenn.edu>:
> On 03/20/10 01:58, Ping Cheng wrote:
>> On Fri, Mar 19, 2010 at 3:28 AM, Henrik Rydberg <rydberg at euromail.se> wrote:
>>> Rafi Rubin wrote:
>>>> Of course this doesn't make as much sense if we follow Henrik's argument about
>>>> suppressing motion until the current values have changed enough.  But there
>>>> again, do we emit just the one contact or the whole group?  If the whole group,
>>>> then my argument stands.  As for reporting only subsets of the contacts as
>>>> needed, we would either have to move tracking to the kernel, or be pretty
>>>> careful about the conditions for "enough".
>>>
>>> The reporting is always for the whole group, since the contacts are
>>> interdependent. I do not see what argument stands because of this, nor the
>>> rationale behind it. Could you clarify, please?
>>
>> If we consider to filter the data in the kernel, reporting ID from the
>> kernel is unavoidable.  Otherwise we would have to either filter the
>> whole group or report the whole group even if there is only one point
>> in the group changed significantly.
>
> Henrik expressed the assumption that the whole group would be transmitted
> together.  I had some thoughts about keeping or not keeping ID, but I have
> another idea.
>
> Why don't we just report delta(ID).

I might have mistaken the definition of tracking ID here.  Dmitry has
asked for a kernel patch to explain the ID.  I will wait until I see
Henrik's patch to make proper comments.

Ping