[PATCH] evdev: Support the "Calibration" string option.

[Peter Hutterer]

On Wed, Nov 11, 2009 at 09:29:04PM +0100, Tias wrote:
> Hello,
> 
> Almost all touchscreen drivers before evdev (elographics, mutouch,
> penmount, evtouch and all deprecated serial drivers) use the same Xorg
> config names for calibration, namely:
> SwapXY
> MinX
> MaxX
> MinY
> MaxY
> 
> Unfortunately, evdev chose the name 'SwapAxes' instead of 'SwapXY'. But
> with the patch from the email below, the gap with the established
> drivers is increased by putting all calibration values in one joined
> 'Calibration <minx> <maxx> <miny> <maxy>'
> 
> I would like to argue for using the same standard config names for the
> evdev driver. This would allow people to easily switch to and from the
> evdev driver: just change the name of the driver. It would also ease the
> work of calibration software and FDI policy files: the same
> min/maxX/Y can be used for all touchscreen drivers.
> 
> 
> Attached is a patch that changes the evdev driver to also use SwapXY
> and to use MinX,MaxX,MinY,MaxY for calibration. The manpage is
> updated too.
> Signed-off-by: Tias Guns <tias at ulyssis.org>

sorry, no. your arguments are good, but I don't want to have two different
options that configure the same thing. it makes it harder to triage bugs and
debug for very little benefit. the only time this is really an issue is when
you're switching drivers between old driver and evdev, in which case some
configuration is involved anyway. we've already released 2.3 with the
options we have, removing them now is not an option.

in the case of Calibration, I think is the better name - it does actually
work differently to the MinX/Y.. options. The driver will still initialize
with the defaults given to it by the kernel. The calibration merely serves
to squash the actual coordinate range into the one obtained from the kernel.
MinX/Y... etc. actually change the coordinate range the device and the
server use.

Cheers,
  Peter