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<div class="moz-cite-prefix">Oups, sorry for my reply-to-you-only,
that was a mistake.<br>
<br>
So my problem with letting events "fall through" to the window is
that I plan to do zoom (hence the OpenGL), both in and out, and
would like to have events working even in a zoomed state... The
window manager idea I'd like to build is one that extends the
multiple virtual workspaces metaphor into an infinite desktop that
you can zoom and pan as you like, and paste a window onto at any
size at any zoom level... It might be a bit hard as a first
project this deep into X stuff, but it's something I've wanted to
build for a long while. So, what are the reasons synthesizing
events will fail (and how will they fail)?<br>
<br>
Hehe, that is the impression I got from plowing through the specs
and code too.. It would kind of be useful to get to talk to one of
those people about how things are "supposed to work".<br>
<br>
Thanks! I think I might need it :P<br>
<br>
<br>
On 19. juni 2018 16:52, Jasper St. Pierre wrote:<br>
</div>
<blockquote type="cite"
cite="mid:CAA0H+QReEENdj3YcatpLBc3Lw_wrNPCxKT+97RYfsr9Fj+AHoQ@mail.gmail.com">
<div dir="ltr">
<div>Hi,</div>
<div><br>
</div>
<div>(Re-adding xorg-devel. Please make sure to keep the list
CC'd in the future)<br>
</div>
<div><br>
</div>
<div>It is possible for a window to set "no background color",
in which case the existing window contents are used for the
pixmap. xclock likely sets no background color. You can check
an individual window's properties with xwininfo.</div>
<div><br>
</div>
<div>Redrawing the screen every frame isn't a bad idea for a
simple compositor to get started. For a more fancy, complete
redraw loop, you can track when windows get drawn to with with
the Damage extension, and schedule a repaint when that
happens. Bonus points if you use the damage rectangles to be
more accurate with your redraw. Also, helpful hint that
windows get their backing pixmaps thrown away when resized --
you need to pay attention to ConfigureNotify and regrab the
backing pixmap with XCompositeNameWindowPixmap, and that whole
jazz.<br>
</div>
<div><br>
</div>
<div>I don't recommend synthesizing input events -- a lot of
things are likely to break or just not work well. Set an empty
input shape on the COW, and make sure to draw windows where
they want to be. Pay attention to MotionNotify events from
windows that are moving.</div>
<div><br>
</div>
<div>I'm unaware of any beginner-level documentation or
tutorials. The number of people that have written a
compositing manager from scratch can be counted on one hand,
and a lot of them had a hand in designing the architecture to
begin with. <a
href="https://magcius.github.io/xplain/article/composite.html"
moz-do-not-send="true">https://magcius.github.io/xplain/article/composite.html</a>
has some ideas of the broader concepts, but none of the
details.<br>
</div>
<div><br>
</div>
<div>Good luck. <br>
</div>
<br>
<div class="gmail_quote">
<div dir="ltr">On Tue, Jun 19, 2018 at 2:01 AM Egil Möller
<<a href="mailto:egil@innovationgarage.no"
target="_blank" moz-do-not-send="true">egil@innovationgarage.no</a>>
wrote:<br>
</div>
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">
<div text="#000000" bgcolor="#FFFFFF">
<div
class="m_-2101153908760320254m_6207735482299778215m_-7306930591589895831moz-cite-prefix">Hi!<br>
<br>
Thanks for answering a noob question :) Ha! That's so
not documented (in an obvious way)! I was assuming that
I could get the initial window content, as already drawn
(obviously clipped to whatever is visible on screen)
directly... So why does xclock "work" then? I just
haven't gotten around to event handling yet, wanted to
learn the drawing/copying methods themselves first...<br>
<br>
Two follow up questions:<br>
<br>
* How should I redraw the screen? As often as I can,
or waiting for some event for all redirected windows
(which event)?<br>
* Can I capture input events (key, mouse) for the
overlay window and then somehow synthesize them for
whatever window / subwindow my window manager thinks it
has drawn in that position? Some docs I read sounded
like this is impossible, and you should turn of input
for the overlay, and position the real window underneath
in a "strategic position"...<br>
<br>
Also, is there any good documentation and/or tutorials
around this anywhere?<br>
<br>
/Egil<br>
<br>
On 19. juni 2018 08:42, Jasper St. Pierre wrote:<br>
</div>
<blockquote type="cite">
<div dir="ltr">
<div>Hi,</div>
<div><br>
</div>
<div>What you're seeing here is a fun little side
effect of composite. As you might be aware,
unredirected X windows don't have any backing
storage beyond the front buffer -- the full window
contents are not really there. That means that when
the X server first goes to redirect these windows,
it decides that it should let the window paint
again, and sends the window an Expose event to let
it know it should repaint. A side effect of this is
that the X server redraws the background for the
window. This is the semantics for what an Expose
event means -- an area that is "Exposed" is the
background color until the client paints over it.</div>
<div><br>
</div>
<div>The client will eventually paint its window
contents, but since your CM does not appear to have
a frame loop, and it only paints once, you do not
see the updated frame contents.<br>
</div>
</div>
<br>
<div class="gmail_quote">
<div dir="ltr">On Sun, Jun 17, 2018 at 1:28 PM Egil
Möller <<a href="mailto:egil@innovationgarage.no"
target="_blank" moz-do-not-send="true">egil@innovationgarage.no</a>>
wrote:<br>
</div>
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">Hi!<br>
<br>
I'm trying to write a new compositing window
manager, and finding the<br>
documentation for the API:s I need quite spread out.<br>
<br>
The particular problem I'm having right now is that
copying some windows (xclock) using<br>
XCompositeRedirectSubwindows and e.g.
XRenderComposite works fine, while<br>
other windows (xterm, xlock) leaves me we a square
with only their<br>
background color. This seems to be true for both
XRenderComposite and <br>
glXBindTexImageEXT. Any ideas what's different
between them, and what I<br>
need to do differently?<br>
<br>
My code is here: <a
href="https://github.com/redhog/InfiniteGlass"
rel="noreferrer" target="_blank"
moz-do-not-send="true">https://github.com/redhog/InfiniteGlass</a><br>
(main code is in wm.c; running "make" ahould give
you an Xephyr nested X<br>
session that shows the problem).<br>
<br>
Thanks in advance,<br>
<br>
Egil Möller<br>
<br>
<br>
<br>
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<br clear="all">
<br>
-- <br>
<div dir="ltr"
class="m_-2101153908760320254m_6207735482299778215m_-7306930591589895831gmail_signature"
data-smartmail="gmail_signature"> Jasper<br>
</div>
</blockquote>
<p><br>
</p>
</div>
</blockquote>
</div>
<br clear="all">
<br>
-- <br>
<div dir="ltr"
class="m_-2101153908760320254m_6207735482299778215gmail_signature"
data-smartmail="gmail_signature"> Jasper<br>
</div>
</div>
</blockquote>
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