Pressure vs touch vs button 0 (was: Re: Tablet to screen coordinate conversion (again))

Giuseppe Bilotta giuseppe.bilotta at
Sun Oct 28 11:55:39 PDT 2007

On Sunday 28 October 2007 11:07, Giuseppe Bilotta wrote:

> Hm. If I set Gimp to relate pressure to size I get a uniform tract: no
> blotches, but no variation either. Which could mean to things: I don't
> know how to set up gimp properly (but I did activate the 3rd evaluator
> as pressure in the extended input device dialog), or it's really
> something related to the driver not being able to tell touches from
> buttons. And since I can't test with xinput I don't know where to
> start debugging this issue. Suggestions?

By using the xidump tool distributed with wacom-tools I could get
confirmation that the issue is that pressure also implies touch
(i.e. first button down). Now what I need to know if I have to disable
this kind of behavior at the kernel level or at the X driver level,
or if it's a X server issue (like the coordinate scaling) that should
be addressed at the server level, or if it's a client issue (they're
somehow supposed to know they should ignore button 1 clicks when 
looking for pressure).

Anybody has any idea? How do other tables handle this?

Giuseppe "Oblomov" Bilotta

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