Re: Report: Brave New X11 World

[ryan lortie <desrt desrt ca>]

On Tue, 2007-29-05 at 20:02 +0100, Pascal Schoenhardt wrote:
> Hi everyone,
> 
> One of the ideas that was suggested when I first submitted my SOC
> application was that users should also have the ability to clone a
> specific section of the screen to another output. The best way to do
> this, in my opinion, is to allow the user to drag and drop a rubber
> band over the area they want to clone, or at least to move a rectangle
> around the screen. Which one of these will be used will depend on
> whether it is possible to handle a clone area that is a different
> aspect ratio or size than the target display device. I have started
> research into how one might allow the user to draw a bounding
> rectangle on the screen (independent of any window), and to get the
> coordinates of that rectangle within the screen. I haven't exactly
> made a lot of progress there... any ideas?

some random stuff to think about:

what would be cool is a special GtkContainer that is constrained to only
take on certain sizes (as acquired from xrandr.  eg: 640x480, 800x600,
etc).  this container would know about its position on the root window
and could notify X to drive the CRTC for that position.

this container could then be used by totem, presentation applications,
etc.

the problem, of course, is that if the window is overlapped then you end
up driving the correct area of the screen to the 2nd monitor, but the
wrong content.  you could use some hackery with composite to solve this
problem since if a window is composited, its contents are never truly
overwritten -- simply copy the composited window to somewhere else on
the screen and show that on the other monitor.  this approach would also
remove the constraint of having the container at specific monitor
resolutions since you could add black areas as part of the copying
process.  the other benefit here is that you don't have any lag at all
in updating the window coordinates if the container changes location on
the screen.

maybe some time in the future it will be possible to tell X to render
directly out of an arbitrary pixmap.  it won't happen this summer,
though.


cheers