XInput2: getting window-relative coordinates?

[Simon Thum]

Peter Hutterer wrote:
> On Sat, Apr 18, 2009 at 10:54:31AM +0200, Florian Echtler wrote:
>>>> However, the second one (controlled by touchpad) reports values in the
>>>> range (1472,1408) to (5472,4448). This is also reported in the Xorg.log
>>>> by the synaptics driver. How can I map these to screen coordinates? As
>>>> the pointer still moves in screen coordinates, the mapping must already
>>>> exist somewhere, I assume.. 
>>>> I know that this is quite beta still, so I'd be very grateful about some
>>>> hints..
>>> right, so the rule for coordinates is:
>>> event_x,event_y, root_x, root_y are in absolute screen coordinates. or should
>>> be anyway.
Shouldn't event_[xy] be relative to the window? At least that's what I 
understand from the xi2 protocol desc. If not, what's the difference 
root<>event then?