Mate-panel and compositing

Thoughts & Feedback
1

Not really an issue, but more of a thought; I recently checked out xfce4-panel and seen it had true compositing, while it appears mate-panel is using fake alpha for the same effect. For someone like me who enjoys all of the dumb things one can do with Compiz, the “Fakeness” becomes noticeable when switching between desktops, rotating the cube or seeing all desktops with Expo.

What gives? Why fake it when everyone else makes it?

Edit: From what I have seen online after a quick glance, this is because of MATE being compiled with GTK2. Any way LTS users can get the GTK3-compiled MATE DE without breaking the everything?

2

Do you mean screen distortions and flicker artefacts when rotating the cube in the upper side of the screen?

3

If you make the panel transparent, then enable cube and rotate cube you’d see what I am talking about.

4

I think we are talking about the same problem. These flicker artefacts or whatever to call them are also visible in the standard settings with the MATE-Ambient theme when rotating the cube.

5

It isn’t that at all; It’s the fake ARGB being present because windows and animations cannot be seen under the panel. In GTK3-compiled MATE this isn’t an issue.

6

Never mind, then. I don’t have enough experience with Compiz to understand what you are talking about.

7

It’s not a Compiz thing, it’s a general compositing thing, but it’s most noticeable with Compiz. I should make a screencap of the issue some time.

8

This;

9Ub6LFT.png1600×900 1.15 MB

The red panel should show content underneath but because of how MATE in 16.04 was built, it doesn't. And yes, that is a window made transparent; That was to show two things;

  • Compositing was enabled when making the screencap
  • Show that all mate-panel is doing is using a piece of the desktop wallpaper to fake ARGB.

This probably happens with Compton too because... well, Compton is another hardware-based compositor included by default and this is an issue with how mate-panel handles compositing, not how Compiz affects panel compositing.

9

I’ve had issues with Compiz in the past. After installing UM I decided to go ahead and give Compiz a shot again with all default settings. I delete the bottom panel and set the top to suit my taste. I was having issues with compositing on the top pane as well as lag during boot, reboot, and shut down. Over the last few days I added the Dev PPA and upgraded Mate to 1.14.1 and did a few other little tweaks. The Mate upgrade seemed to amplify the issue a bit more. This morning I switched to Compton and purged Compiz. All seems to be working fine now.