[RFC] xserver: Masked valuators, DIDs, and ABS_MT_SLOT

[Henrik Rydberg]

Peter Hutterer wrote:
> On Mon, Jul 05, 2010 at 09:15:42PM -0400, Chase Douglas wrote:
>> On Tue, 2010-07-06 at 11:04 +1000, Peter Hutterer wrote:
>>> On Thu, Jul 01, 2010 at 06:36:18PM -0400, Chase Douglas wrote:
>>>>       Add extra functions for masked valuator input API
>>> yes, but no :)
>>> idea is right, implementation needs work. Please send this as a patch for
>>> better comments. Most notably, you don't need GetPointerEventsM, just change GPE to take
>>> the mask bits and fix up the callers in the DDXs.
>> I saw GPE is referenced in /usr/include/xorg/input.h, so I was afraid to
>> modify its prototype. I certainly can change it though.
> 
> don't be. we don't really care about ABI guarantees across server revisions,
> if a change makes sense add it. the only callers of GPE are the DDX's anyway
> and they are in-tree. well, except VNC, they'll just have to live with it ;)
> 
>> <snip>
>>>>       Add atom name for ABS_MT_SLOT properties
>>> I'm not sure at all about this. I was hoping to abstract the slots so we
>>> don't need to expose thos to the clients.
>> Given the approach that I have been taking, we have to expose the slot
>> number to the clients. If you only send one touch data point per event,
>> the client needs to know about its tracking data. The easiest way to do
>> this is to just pass the ABS_MT_SLOT property from the kernel.
> 
> I thought the valuator number (or set of valuators) implicitly defined a
> slot.

Yes, I believe we have seen an extremely rapid development here, passing through
three different stages so far. It would certainly help if we discussed the
protocol details a bit at this stage.

Cheers,
Henrik