The following area of code in wcmCommon.c seems suspicious to me:
if (!priv->oldProximity)
priv->minPressure = filtered.pressure;
else
priv->minPressure = min(priv->minPressure,
filtered.pressure);
/* normalize pressure to FILTER_PRESSURE_RES */
tmpP = (filtered.pressure - priv->minPressure)
* FILTER_PRESSURE_RES;
tmpP /= (common->wcmMaxZ - priv->minPressure);
filtered.pressure = (int)tmpP;
The whole block is in a feedback loop as best I can tell. The logic
is invoked every time a package is received from HW; even if pressure
does not change in the packet. So we can normalizing pressure values
that have already been normalized which would explain it being scaled
to high.
Another concern is that in first tmpP statement, it acts like
minPressure is un-normalized and in second tmpP statement, it acts
like minPressure is already normalized. I would think that has some
side affect on outcome as well.
I see no pressure issues in my usage of Bamboo but perhaps its
pressure range is same as FILTER_PRESSURE_RES and so hides problems.
Chris
On Fri, Jan 7, 2011 at 9:10 AM, AndrewP <[email protected]> wrote:
> Actually, issue is still open. I didn't have any troubles with xsetwacom,
> though.
>
>
> On Thu, Jan 6, 2011 at 13:22, ODDie <[email protected]> wrote:
>>
>> Hi
>>
>> I found some mailing-list thread on linuxwacom project @soureforge.net
>> about your issues with wacom pressure on Thinkpad X201t
>> (https://sourceforge.net/mailarchive/message.php?msg_id=26816222).
>> I have Thinkpad X200t and experiencing the same issue (stylus to much
>> "sensitive" on pressure). I also can't change PressCurve by xsetwacom.
>>
>> Did you managed to get it work correctly under linux (any distro)? I
>> use Ubuntu Lucid (10.04 LTS) 32bit with xf86-input-wacom 0.10.6 (also
>> checked git version 0.10.10 with no luck - reverted back to 0.10.6 as
>> Tom Jaeger's wacomrotate script did't work with git ver.).
>>
>>
>> Thanks in advance for an answer
>> --
>> Paweł Jonik | ODDie
>> mail: [email protected]
>> www: http://ODDied.net
>
>
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