Re: Live Touchscreen Calibration [WAS: magictouch touch screen driver]

On Fri, Jun 10, 2005 at 10:53:47AM -0400, Fred Gleason wrote:
>On Friday 10 June 2005 03:17, Veikko Werner wrote:
>> actually a great thing to have, but not that easy.
>> The main problem is, that the driver itself has to be disabled.
>
>Why so?  AFAICT, we basically need two things:
>
>1)  The ability to get 'raw' --i.e. unscaled -- data from the device during 
>the calibration run.
>
>2)  Some way to set the calibration parameters of the driver based on the 
>results of 1).
>
>Both of these could be accomplished by means of adding appropriate new methods 
>to each driver.  While I suppose this does involve effectively 'disabling' 
>the driver for the duration of the calibration run, this fact can be 
>completely hidden from the server.  The server merely doesn't receive pointer 
>updates while calibration is in progress.
>
>Or am I missing something here?

Sounds reasonable to me.  The XInput extension could be enhanced to
provide calibration requests which would be the mechanism for a calibration
utility to communicate with the driver.

The problem with most of the solutions I've seen for this so far is that
they attempt to open a communication path directly between the driver
and a calibration utility, often creating security problems.  The X
server already provides an authenticated mechanism for doing such things.

David