Rounded corners and titlebars are inconsistent

[widogg]

I'm using Picom with I3 and I use rounded borders.

When using stacked or tabbed windows, the title bar and windwo gets rounded in all directions.

This means, the area where the title bar meets the window gets rounded in both directions. This doesn't happens on regular layouts and this is how (I think) should look like.

Here are 3 screenshots to try showing this. These examples use the exact same window.

Here are 2 windows, both are "tabbed"

Here's one "regular" window and one tabbed

Here are the same window, both "regular". This is how they should look all the time (to me)

Other context:

• I'm running stock Ubuntu 24.04
• i3 version 4.23
• polybar version 3.7.1
• Still on Xorg
• • X.Org X Server 1.21.1.11
• • X Protocol Version 11, Revision 0

Here's my Picom configuration:

# General
backend = "glx";
glx-no-stencil = true
glx-swap-method=1;

vsync = true;
detect-rounded-corners = true;
#detect-rounded-corners = false;
detect-client-leader = false;
detect-client-opacity = true;

use-damage = true;
log-level = "error";
mark-ovredir-focused = true;

## Corners
corner-radius = 10;
rounded-corners-exclude = [
  "window_type = 'dock'",
  "window_type = 'desktop'"
];

## Shadow
shadow = false;

## fading
fading = true;
fade-delta = 6;
fade-in-step = 0.03;
fade-out-step = 0.03;
fade-exclude = [];

# Window Types
wintypes: {
  normal = { fade = true; opacity = 1; }
  tooltip = { fade = false; opacity = 1; focus = false; };
  dock = { fade = false; opacity = .95; }
  dnd = { fade = false; opacity = .9; }
  popup_menu = { opacity = 1; }
  dropdown_menu = { opacity = 1; }
};

blur-background-exclude = [
 "window_type = 'menu'",
 "window_type = 'dropdown_menu'",
 "window_type = 'popup_menu'",
 "window_type = 'tooltip'"
];

opacity-rule = [
  "100:class_g = 'Google-chrome'",
  "100:class_g = 'i3lock'",
  "100:class_g = 'gwenview'",
  "100:class_g = 'darktable'"
];

[CyberKite]

picom does not implement WM-specific workarounds. You could try to make a window rule for it

[widogg]

picom does not implement WM-specific workarounds

I guess this is a "problem" with I3. As a test, I tried xwininfo on the titlebar, comparying "normal" layout vs stacked, expecting to have 0 differences.... but I was wrong

--- standard-title.out  2025-07-20 19:29:59.030461626 -0300
+++ stacked-title.out   2025-07-20 19:30:13.671391884 -0300

-xwininfo: Window id: 0x240179a "wind"
+xwininfo: Window id: 0x28e4d3 (has no name)

-  Absolute upper-left X:  3016
-  Absolute upper-left Y:  667
-  Relative upper-left X:  2
-  Relative upper-left Y:  24
-  Width: 820
-  Height: 409
+  Absolute upper-left X:  3014
+  Absolute upper-left Y:  643
+  Relative upper-left X:  3014
+  Relative upper-left Y:  643
+  Width: 824
+  Height: 24
   Depth: 32
   Visual: 0x96
   Visual Class: TrueColor
   Border width: 0
   Class: InputOutput
-  Colormap: 0x240179b (not installed)
+  Colormap: 0x200000 (not installed)
   Bit Gravity State: ForgetGravity
   Window Gravity State: NorthWestGravity
   Backing Store State: NotUseful
   Save Under State: no
   Map State: IsViewable
-  Override Redirect State: no
-  Corners:  +3016+667  -4+667  -4-4  +3016-4
-  -geometry 820x409-2-2
+  Override Redirect State: yes
+  Corners:  +3014+643  -2+643  -2-413  +3014-413
+  -geometry 824x24-2+643

It's interesting to me that the geometry of the window has changed, even when the only thing I did was change the I3 layout (but I did not explicitely changed the sizes).

It looks as if I3 has different ways to inform different layouts

You could try to make a window rule for it

I would like to try that, but I'm unsure how should I approach it. My 2 initial thoughts are: Add 2 items in wintypes. Add one item for the title and round top corners, and another tipe for the window and round bottom corners

[dkaszews]

Isn't this caused by i3 using a separate window for stack/tab list? If so, I believe this could be fixable using #918 to match them and disable only top/bottom rounded corners.

[yshui]

yep, i think allowing rounding specific corners is a good idea, let's continue in #1450