Re: [PATCH 7/7] elantech: average the two coordinates when 2 fingers

["Éric Piel" <E.A.B.Piel@tudelft.nl>]

Op 02-08-10 13:22, Henrik Rydberg schreef:
> On 08/02/2010 01:12 PM, Éric Piel wrote:
:
>>> You need to add the tracking id and a couple of lines, but i do not see why the
>>> 2->1 transition would be treated any differently. The one-finger coordinate
>>> would be close to either position[0] or position[1], which would determine the
>>> tracking id to keep. Every time you add a finger you add a new tracking id. What
>>> is your planned support for three fingers?
>> Yes, yes, it's probably fairly easy to do some kind of tracking. But I
>> think that as long as the hardware does not provide such a thing, it's
>> better to do the minimum in kernel space, just enough to be meaningful,
>> and leave the rest to userspace.
> 
> 
> The implemented part could also be done in userspace. Going half-way just to
> circumvent buggy behavior in synaptics is really not a good idea.
No, we've been going from protocol 0.5 (report max/min coordinates) to
protocol A.5 (report finger positions, often with correct track ID). My
argument is that it's not because we are half-way to B, by chance, that
we should go up to it. We do just the minimum to respect the minimum
protocol. Once the driver respects that protocol, all the fancy stuff
has to stay in userspace. There is already mtdev (I'm sure I don't have
to tell you ;-) ), I don't see the point of doing some copy-pasting.

Eric
--
To unsubscribe from this list: send the line "unsubscribe linux-input" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html