XInput extension, xf86XInput, evdev and a spaceball

[Peter Hutterer]

On Sun, Aug 30, 2009 at 08:17:00PM -0400, Thomas Jaeger wrote:
> Peter Hutterer wrote:
> > On Mon, Aug 31, 2009 at 02:08:08AM +1000, Daniel Stone wrote:
> >> Depends on how you map the axes.  I guess a 'map tilt to x/y' property
> >> might be useful, since some people really want to use it as a pointer,
> >> while others don't.
> > 
> > working on it. see http://bugs.freedesktop.org/show_bug.cgi?id=21129
> 
> Interesting, but shouldn't we move axis labels and ranges around when
> the property is changed?  It might just be easier to specify which axes
> are used for x and y, which is currently hard-coded to be 0 and 1.

axis labels - no, I don't think so. IMO they should represent the physical
order of the axes to represent what the device can do. from a UI point of
view, it allows for applications that ask the user things like "what do you
want the pressure axis to do?".

the special case is two axes mapped to the same logical axis which has
caveats for both approaches.
if the labels change around with the mapping you don't know which axes are
available anymore (axis N can be either physical pressure or proxmity).
if the labels stay fixed, you don't necessarily know which axis an event was
generated from.

axis ranges - definitely. the patch in 21129 isn't ready yet and dealing
with axis ranges is just one of the issues with it.

> And I suppose calibration could be handled in the same way.

correct.

Cheers,
  Peter