It seems as though it should be possible to use Gimp with two mice (or
similar devices) to some advantage, using them to control different
tools, using different settings.
With AlwaysCore and the Xinput extended devices disabled (probably a
common setup) you get what you'd expect - more physical devices
sharing the same physical pointer and Gimp tools. Of course, this
isn't really using two mice effectively.
However with the extended device enabled, Gimp's behaviour (or is
this GTK+ / XFree behaviour?) breaks down. Gimp can no longer properly
detect the core cursor (you can't draw with it) and the additional
mouse seems to always generate mouse down events at the origin,
making it quite unusable.
I started investigating this before, but didn't have a permanent setup
where I could reproduce it. Now I do, so if anyone has any pointers
or advice I'd appreciate it.
Nick.
