generic touchscreen calibration

Søren Hauberg hauberg at
Fri Sep 11 12:07:46 PDT 2009


2009/9/10 Tias <tias at>:
> In the end, I had to hack up the ancient tkxinput because it was the only
> device independent calibrator (it uses Xinput to read the coordinates). On
> the other hand, I was impressed by the simplicity of the calibrator that
> Soren Hauberg sent to this list in july (thread titled 'Evdev touchscreen
> calibration?'), although it was written for usbtouchscreen driven devices
> specifically.
> I figured that a generic calibration program should be device independent
> when reading calibration data, and device dependent in how to use the data.
> I've adapted Soren's calibrator to do exactly this: it reads the current
> calibration from Xinput. When the usbtouchscreen driver is used, it
> dynamically changes the calibration. Otherwise it prints the new calibration
> data in xorg.conf format on stdout. Other actions would be possible too,
> like rewriting the xorg.conf directly, maybe even use some new evdev/Xinput2
> goodness ?

It's been quite a while since I was working on this (I changed job, so
I never got to finish this), so my comments might not actually be

First, I'd like to add that I'm glad you're spending time on
resurecting my old code. Thanks :-)

Second, part of this code was added before the 'evdev' X11 driver got
support for touchscreens. This driver allows you to set the
calibration parameters at run-time without making changes to xorg.conf
(hence no restart of X). I think the calibration tool should use this
instead of working with xorg.conf.

Third, the code that interacts with the 'usbtouchscreen' kernel module
should probably be dropped. It's tied too much to some specific
hardware. Since the parameters can just be handled by the 'evdev' X11
driver, I don't think kernel interaction is needed anymore.

Let me know if you need anything from me,

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