Re: [PATCH] input: mt: Add hovering distance axis

[Ping Cheng]

On Wed, Dec 8, 2010 at 10:05 AM, Dmitry Torokhov
<dmitry.torokhov@xxxxxxxxx> wrote:
> On Wed, Dec 08, 2010 at 09:46:04AM -0800, Chase Douglas wrote:
>> On 12/07/2010 12:27 AM, Henrik Rydberg wrote:
>> > Touch devices capable of hovering, i.e., fingers detected a distance
>> > from the surface, are not supported by the current input MT
>> > protocol. This patch adds ABS_MT_DISTANCE, which may be used to
>> > indicate the distance between the contact and the surface.
>>
>> Have you given thought to calling it ABS_MT_Z instead? I have no real
>> problem with ABS_MT_DISTANCE per se, but ABS_MT_Z is more clearly
>> defined in my head. If I was new to MT development I may wonder if
>> ABS_MT_DISTANCE had anything to do with distance between points or some
>> other object.
>
> X/Y/Z imply that we fully engaged the device and it is 3 dimensional.
> Distance says that we are approaching the device but have not directly
> engaged it yet.
>
> I think ABS_DISTANCE was added at Pings request and ABS_MT_DISTANCE is
> modeled after ST one. Ping, could you refresh my memory why we needed
> ABS_DISTANCE?

ABS_DISTANCE is used in wacom driver as the distance between the tool
tip and the tablet.

Ping
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/