As the compositor starts, the xfce4-panel on the bottom is printed on the top for less than a second

[Giova84]

I’m using Compton v 7.4; I am waiting that Picom will hit the community repo of my distro: Manjaro Xfce ( xfce 4.14) x64, stable branch.

Some info of my system:
Video Driver: xf86-video-intel 1:2.99.917+893+gbff5eca4-1

Output of inxi:

CPU:       Topology: Dual Core model: Intel Core i5-3210M bits: 64 type: MT MCP arch: Ivy Bridge rev: 9 L2 cache: 3072 KiB 
           flags: avx lm nx pae sse sse2 sse3 sse4_1 sse4_2 ssse3 vmx bogomips: 19963 
           Speed: 3045 MHz min/max: 1200/3100 MHz Core speeds (MHz): 1: 3081 2: 2973 3: 2955 4: 2901 
Graphics:  Device-1: Intel 3rd Gen Core processor Graphics vendor: Hewlett-Packard driver: i915 v: kernel bus ID: 00:02.0 
           Display: x11 server: X.Org 1.20.5 driver: intel resolution: 1366x768~60Hz 
           OpenGL: renderer: Mesa DRI Intel Ivybridge Mobile v: 4.2 Mesa 19.2.6 direct render: Yes 

glxinfo -B:

name of display: :0.0
display: :0  screen: 0
direct rendering: Yes
Extended renderer info (GLX_MESA_query_renderer):
    Vendor: Intel Open Source Technology Center (0x8086)
    Device: Mesa DRI Intel(R) Ivybridge Mobile  (0x166)
    Version: 19.2.6
    Accelerated: yes
    Video memory: 1536MB
    Unified memory: yes
    Preferred profile: core (0x1)
    Max core profile version: 4.2
    Max compat profile version: 3.0
    Max GLES1 profile version: 1.1
    Max GLES[23] profile version: 3.0
OpenGL vendor string: Intel Open Source Technology Center
OpenGL renderer string: Mesa DRI Intel(R) Ivybridge Mobile 
OpenGL core profile version string: 4.2 (Core Profile) Mesa 19.2.6
OpenGL core profile shading language version string: 4.20
OpenGL core profile context flags: (none)
OpenGL core profile profile mask: core profile

OpenGL version string: 3.0 Mesa 19.2.6
OpenGL shading language version string: 1.30
OpenGL context flags: (none)

OpenGL ES profile version string: OpenGL ES 3.0 Mesa 19.2.6
OpenGL ES profile shading language version string: OpenGL ES GLSL ES 3.00 

compton –diagnostics:

### Extensions:

* Shape: Yes
* XRandR: Yes
* Present: Present

### Misc:

* Use Overlay: Yes
* Config file used: /home/user/.config/compton.conf

### Drivers (inaccurate):

Intel  

My compton.conf:

backend = "glx";

glx-no-stencil = true;
use-damage = true;
vsync = true;
sw-opti = true;
unredir-if-possible = true;

glx-no-rebind-pixmap = true;

shadow = true;
shadow-radius = 6;
shadow-offset-x = -7;
shadow-offset-y = -7;

shadow-exclude = [
    "! name~=''",
    "name = 'Notification'",
    "name = 'Plank'",
    "name = 'Docky'",
    "name = 'Kupfer'",
    "name = 'xfce4-notifyd'",
    "name *= 'VLC'",
    "name *= 'mpv'",
    "name *= 'compton'",
    "name *= 'conky'",
    "name *= 'Chromium'",
    "name *= 'Chrome'",
    "name *= 'Firefox'",
    "name *= 'tor-browser'",
    "name *= 'VirtualBox'",
    "name *= 'xpad'",
    "class_g = 'conky'",
    "class_g = 'Firefox' && argb",
    "class_g = 'Kupfer'",
    "class_g = 'Synapse'",
    "class_g ?= 'Notify-osd'",
    "class_g ?= 'Cairo-dock'",
    "class_g ?= 'Xfce4-notifyd'",
    "class_g ?= 'Xfce4-power-manager'",
    "class_g ?= 'VirtualBox'",
    "class_g = 'xpad'",
    "name *= 'xfce4-panel'",
    "class_g = 'xfce4-panel'",
    "n:e:Notification",
    "_GTK_FRAME_EXTENTS@:c",
    "_NET_WM_STATE@:32a *= '_NET_WM_STATE_HIDDEN'"
];

shadow-ignore-shaped = false;

inactive-opacity = 1;
active-opacity = 1;
frame-opacity = 1;
inactive-opacity-override = false;

blur-background = false;
blur-background-fixed = false;
blur-kern = "3x3box";
blur-background-exclude = [
];

fading = true;
fade-delta = 4;
fade-in-step = 0.03;
fade-out-step = 0.03;
no-fading-destroyed-argb = true;

fade-exclude = [ 
   "! name~=''",
    "n:e:Notification",
    "name *= 'Firefox'",
    "class_g = 'Firefox' && argb",
    "name *= 'xfce4-panel'",
    "class_g = 'xfce4-panel'"

];

wintypes:
{
  tooltip = { fade = true; shadow = false; opacity = 0.98; focus = true; full-shadow = false; };
  notify = { fade = false; shadow = false; opacity = 1.00; focus = true; full-shadow = false; };
  dock = { fade = false; shadow = false; }
  dnd = { fade = false; shadow = false; }
  popup_menu = { opacity = 1; }
  dropdown_menu = { opacity = 1; }
};

I start compton as compton --experimental-backends --config /home/user/.config/compton.conf -b

I use –experimental-backends because straight glx has a minor issue: also after an hour, by using ps_mem, I see that eat a lot of ram, it start to use about 17 MB of RAM, and after about an hour it arrives to about 50 - 70 MB. Instead, by using –experimental-backends, it start to use about 8 MB of RAM and at maximum it can arrives to 17 MB.

In this way I have a good tearfree experience (I also tried xrender with –experimental-backends but it gives poor performances, eg the scrolling in FireFox is lagging and clunky.

After these informations I explain what happen: on my Desktop, on the Bottom, I have an xfce4-panel: as Compton starts, for an instant (i would say less than a second, it appears like a “flash”)
this panel is printed on the top of the screen, but not entirely, are printed only the icons of the panel.

I have tried many options in compton.conf, as you can see also by adding xfce4-panel in fade-exclude and shadow-exclude section, but this behaviour wit xfce4-panel still occurs. Doesn't occurs if i not use –experimental-backends.

Are you aware of something similar which maybe has been already fixed? Or I should change something in my compton.conf?

EDIT:
The –experimental-backends, after a while of usage, decreases the general performance and introduce also other artifacts. Tell me how can I investigate further, though I suspect that due the old video card (Intel HD4000) and platform, there is little to do and hope.

[Giova84]

I have noticed another interesting thing, about xrender backend, and this occurs if i start it as --experimental-backends or not:
When I mirror the screen on HDMI, the scrolling on FireFox become very choppy and sluggish: this doesn't occurs using glx (started or not with --experimental-backends because as experimental doesn't consume too much RAM).

[Giova84]

Sorry for the flood of messages: I'm further testing combinations of various options and I report them here to help you with the development.
Currently I removed --experimental-backends because I noticed that when I browse websites with a lot of contents (eg videos and animated images, like some pages on reddit) after a while the fan of cpu spinning like a crazy. I can say it for sure: I've tried various time also after reboots.
I've modified the configuration file for the intel video card /etc/X11/xorg.conf.d/20-intel.conf by adding Option "DRI" "3" which has benefited: the scrolling is more smooth and everything feels more responsive; I also don't see anymore artifacts around and compton doesnt eat the big aomunt of ram as before.

Currently this is the configuration file of compton:

backend = "glx";

glx-no-stencil = true;
use-damage = true;
vsync = true;
detect-client-leader = true;
sw-opti = true;
unredir-if-possible = false;

glx-no-rebind-pixmap = false;

shadow = true;
shadow-radius = 6;
shadow-offset-x = -7;
shadow-offset-y = -7;


shadow-exclude = [
    "! name~=''",
    "name = 'Notification'",
    "name = 'Plank'",
    "name = 'Docky'",
    "name = 'Kupfer'",
    "name = 'xfce4-notifyd'",
    "name *= 'VLC'",
    "name *= 'mpv'",
    "name *= 'compton'",
    "name *= 'conky'",
    "name *= 'Chromium'",
    "name *= 'Chrome'",
    "name *= 'Firefox'",
    "name *= 'tor-browser'",
    "name *= 'VirtualBox'",
    "name *= 'xpad'",
    "class_g = 'conky'",
    "class_g = 'Firefox' && argb",
    "class_g = 'Kupfer'",
    "class_g = 'Synapse'",
    "class_g ?= 'Notify-osd'",
    "class_g ?= 'Cairo-dock'",
    "class_g ?= 'Xfce4-notifyd'",
    "class_g ?= 'Xfce4-power-manager'",
    "class_g ?= 'VirtualBox'",
    "class_g = 'xpad'",
    "n:e:Notification",
    "_GTK_FRAME_EXTENTS@:c",
    "_NET_WM_STATE@:32a *= '_NET_WM_STATE_HIDDEN'"
];

shadow-ignore-shaped = false;


inactive-opacity = 1;
active-opacity = 1;
frame-opacity = 1;
inactive-opacity-override = false;


fading = true;
fade-delta = 3;
fade-in-step = 0.03;
fade-out-step = 0.03;

fade-exclude = [ 
];

wintypes:
{
  tooltip = { fade = true; shadow = false; opacity = 0.98; focus = true; full-shadow = false; };
  notify = { fade = false; shadow = false; opacity = 1.00; focus = true; full-shadow = false; };
  dock = { fade = false; shadow = false; }
  dnd = { fade = false; shadow = false; }
  popup_menu = { opacity = 1; }
  dropdown_menu = { opacity = 1; }
};

P.S: also the option sw-opti = true; seems to help for performance.

[yshui]

Please try to have your issue report focus on a single issue, otherwise it's difficult for the dev to track problems.

As for the problem with xfce4-panel, I am not able to fully grasp what is happening exactly. It would help if you have video capture, and preferably also a apitrace. But I suspect it's just some xfce4 oddities.

adding Option "DRI" "3" which has benefited

Yes, you should always use DRI3, DRI2 has caused us lots of problems.