Not sure background_blur for KDE (kitty 0.34.0) is working correctly.

[jonwilts]

Describe the bug

Kitty 0.34.0 running with a wayland backend on KDE Plasma 6.0.3, on an old 2015 Macbook Air with an Intel HD6000 graphics chip and the latest i915 driver.

background_opacity 0.8
dynamic_background_opacity yes

With background_blur=0 kitty + desktop looks like this:

With background_blur=1 or any other integer > 0, kitty looks like this:

If it isn't clear - the background is now almost entirely black & opaque. That darker rectangle is a window behind kitty - so there is some transparency - but as you can see it's blurred beyond all usability. I tried various values between 1 and 64 and there's no discernible difference - just total blur!

Also, when background_blur > 0, resizing the window causes this:

To Reproduce Steps to reproduce the behavior:

• Install KDE 6.0.3
• Install Kitty 0.34.0
• Set kitty.conf values as above.

Screenshots See above.

Environment details

kitty 0.34.0 (2b671100d9) created by Kovid Goyal
Linux air 6.8.5-zen1-1-zen #1 ZEN SMP PREEMPT_DYNAMIC Thu, 11 Apr 2024 01:47:18 +0000 x86_64
Arch Linux 6.8.5-zen1-1-zen (/dev/tty)

DISTRIB_ID="Arch"
DISTRIB_RELEASE="rolling"
DISTRIB_DESCRIPTION="Arch Linux"
Running under: Wayland (kwin 6.0.3) missing: single_pixel_buffer
Frozen: True
Paths:
  kitty: /opt/kitty/kitty_2024-04-15/bin/kitty
  base dir: /opt/kitty/kitty_2024-04-15/lib/kitty
  extensions dir: /opt/kitty/kitty_2024-04-15/lib/kitty-extensions
  system shell: /usr/bin/bash
Loaded config files:
  /home/jon/.config/kitty/kitty.conf

Config options different from defaults:
allow_remote_control       yes
background_blur            64
confirm_os_window_close    0
dynamic_background_opacity True
font_family                FiraCode Nerd Font
font_features:
{'FiraCodeNF-Ret': ('+ss03',)}
font_size                  10.5
initial_window_height      (836, 'px')
initial_window_width       (1070, 'px')
linux_display_server       wayland
listen_on                  unix:@kitty{kitty_pid}
remember_window_size       False
shell_integration          frozenset({'disabled'})
tab_bar_edge               1
tab_bar_margin_height      TabBarMarginHeight(outer=5.0, inner=0)
tab_bar_style              slant
wayland_enable_ime         False
window_padding_width       FloatEdges(left=5.0, top=5.0, right=5.0, bottom=5.0)
Added shortcuts:
    shift+super+[ →  previous_window
    shift+super+] →  next_window
    shift+super+c →  copy_to_clipboard
    shift+super+t →  new_window
    shift+super+v →  paste_from_clipboard
    super+[ →  previous_tab
    super+] →  next_tab
    super+enter →  toggle_fullscreen
    super+t →  new_tab
Colors:
    active_tab_background      #e5e9f0   
    active_tab_foreground      #2e3440   
    inactive_tab_background    #4c566a   
    inactive_tab_foreground    #2e3440   

Important environment variables seen by the kitty process:
    PATH                                /usr/local/sbin:/usr/local/bin:/usr/bin:/opt/cuda/bin:/opt/cuda/nsight_compute:/opt/cuda/nsight_systems/bin:/var/lib/flatpak/exports/bin:/usr/bin/site_perl:/usr/bin/vendor_perl:/usr/bin/core_perl
    LANG                                en_US.UTF-8
    SHELL                               /usr/bin/bash
    DISPLAY                             :1
    WAYLAND_DISPLAY                     wayland-0
    USER                                jon
    XDG_CONFIG_DIRS                     /home/jon/.config/kdedefaults:/etc/xdg
    XDG_CURRENT_DESKTOP                 KDE
    XDG_DATA_DIRS                       /home/jon/.local/share/flatpak/exports/share:/var/lib/flatpak/exports/share:/usr/local/share:/usr/share
    XDG_MENU_PREFIX                     plasma-
    XDG_RUNTIME_DIR                     /run/user/1000
    XDG_SEAT                            seat0
    XDG_SEAT_PATH                       /org/freedesktop/DisplayManager/Seat0
    XDG_SESSION_CLASS                   user
    XDG_SESSION_DESKTOP                 KDE
    XDG_SESSION_ID                      2
    XDG_SESSION_PATH                    /org/freedesktop/DisplayManager/Session1
    XDG_SESSION_TYPE                    wayland
    XDG_VTNR                            1

Additional context Try to reproduce the problem with kitty --config NONE if you cannot then post a minimal kitty.conf that reproduces the problem. If the problem involves interaction with some other terminal program post a minimal config for that program to reproduce the problem as well.

[kovidgoyal]

kitty has no control over the blurring the KDE blur protocol is simply a boolean. The integer value is used only on macOS. If you dont like the blurring, report it to KDE.

[jonwilts]

Ah - ok - thank you. Configuring the blur effect in KDE does improve it.

However, I think the resizing issue is kitty's - resizing eg konsole works as expected.

[jonwilts]

These pictures illustrate the resizing issue better:

Kitty at initial launch, over a Dolphin window:

Resizing kitty by stretching the window downwards:

[jonwilts]

Confirmed that fixes it. Thank you.