Picom: [Feature request] Do not show overlapped window as transparency

[Anarky]

Hello,

When the window transparency is enabled (hope the kawase blur comes soon), would it be possible to add an option to use the wallpaper/desktop as the background instead of what's directly behind the focused window?
While it looks great on tiled applications, I usually use 3/4 windows in fullscreen and it doesn't look as pretty because the transparency looks darker and darker and terminals are less readable.

Thanks!

[clort81]

I support this idea Anarky.

I have begun poking around compton and where the shader gets invoked, but i still do not understand enough about glx to make the .glsl shader use the root window as a source buffer, instead of whatever is underlying.

In case anyone reading hasn't understood from the image - click for the full-sized view. This allows you to have visible background images, while still being able to read the text in the topmost window.

[Anarky]

Thanks for your mock-up, that's exactly what I had in mind :)

I would love to help but unfortunately I don't know anything about graphics programming.

[yshui]

This is much easier than I originally anticipated. So here you go, set --transparent-clipping and have fun. (note it only work when you use --experimental-backends)

P.S. I struggled to come up with a name for this option, suggestions welcome.

[clort81]

Very exciting yshui! +∞ THANKS!!!

picom built without problems on nvidia jetson nano (aarch64) but i get get segfaults. I tried with old ~/.compton.conf and without. Tried

./picom --refresh-rate 30 --glx-no-rebind-pixmap --use-damage --xrender-sync-fence --backend glx --experimental-backends --transparent-clipping

and just ./picom from build/src...

with just ./picom and no ~/compton.conf, gdb and bt shows:

Reading symbols from ./picom...
(No debugging symbols found in ./picom)
(gdb) run
Starting program: /big/pcbak/Projects/comptonyshui/picom/build/src/picom 
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/aarch64-linux-gnu/libthread_db.so.1".
[ 12/10/2019 21:24:46.508 session_init WARN ] This compositor has been renamed to "picom", the "compton" binary will not be installed in the future.

Program received signal SIGSEGV, Segmentation fault.
0x0000007fb7784620 in ?? () from /usr/lib/aarch64-linux-gnu/libGLX.so.0
(gdb) bt
#0  0x0000007fb7784620 in ?? () from /usr/lib/aarch64-linux-gnu/libGLX.so.0
#1  0x0000007fb7782ecc in ?? () from /usr/lib/aarch64-linux-gnu/libGLX.so.0
#2  0x0000007fb777f8f8 in ?? () from /usr/lib/aarch64-linux-gnu/libGLX.so.0
#3  0x0000007fb777d8fc in glXGetProcAddress () from /usr/lib/aarch64-linux-gnu/libGLX.so.0
#4  0x0000005555592e04 in glxext_init.part ()
#5  0x00000055555790fc in init_render ()
#6  0x0000005555560f34 in main ()

I saw stuff appended to ~/compton.log but when i removed it and reran picom
i got no new ~/compton.log, for some reason.

Can you suggest anything for me to try? Thank You So Much. <3
I just found picomlog.txt http://0x0.st/zUfm.txt

[yshui]

@clort81 there seems to be a problem with your OpenGL libraries. By all means, this is a separate issue. Please open a new issue for this problem.

[mmhobi7]

Shadows still overlap over each other. Attached are images to show what I mean.

Great work btw picom is amazing