LCA: Catching up with X.org

Posted Jan 24, 2009 22:04 UTC (Sat) by wingo (guest, #26929)
Parent article: LCA: Catching up with X.org

One big unclear issue for me is the status of input redirection. It's clear that the in-kernel GPU memory manager was essential to support output redirection (compiz with direct rendering is a case of this), but what support exists for mapping clicks on polygons to clicks in X windows coordinates?

It's so difficult to get a clear picture on GPUs these days, because the know-nothing fora get all of the google hits.

LCA: Catching up with X.org

Posted Jan 26, 2009 1:16 UTC (Mon) by njs (subscriber, #40338) [Link] (2 responses)

Input redirection is mostly unrelated to GPUs, but last I heard (6 months ago, maybe?), this was somewhat stalled -- the first approach, of the server handing off input events to a special client (the compositing manager) and letting it do the coordinate conversions, turned out not to work. (They ran into problems coordinating everyone during e.g. grab handling.) The new idea is for the compositing manager to actually upload a triangle mesh to the server and then have the server use that to do the coordinate transformation itself... but no-one was actively working on this, and there's a limited quantity of keithp-types to go around.

Someone else may have more detailed/up-to-date information.

LCA: Catching up with X.org

Posted Jan 26, 2009 17:53 UTC (Mon) by yokem_55 (subscriber, #10498) [Link] (1 responses)

Qt 4.5 seems to have some support for input redirection. See the WolfenQt demo for an example. But I'm not sure if this is quite the same thing.

LCA: Catching up with X.org

Posted Jan 30, 2009 2:46 UTC (Fri) by jamesh (guest, #1159) [Link]

This isn't something a toolkit could implement itself.

Imagine a compositing window manager that takes a particular window and renders it at twice its original dimensions. Input redirection is needed to let the user interact with this zoomed window in a way that the underlying application can understand (halve the x and y coordinates and translate to match the real window position).

All this has to happen before the input reaches the application. After all, we want clicks that occur outside the application's window to be directed to it.