Run in a window:

$ gtk4_shadertoy test/data/afl_ext/very-fast-procedural-ocean.glsl

Right click for menu or

kbd	desc
f	fullscreen
r	toggle an FPS overlay
esc	close window
space	pause
ctrl-o	open another shader

Run fullscreen (-f) and show the FPS overlay (-r):

$ gtk4_shadertoy -fr < file.glsl

Put the app on the lowest window layer (X11 only), ignore kbd/mouse input:

$ gtk4_shadertoy -fr -b file.glsl

To exit the app in such a wallpaper mode, you'll need to kill it either sending WM_DESTROY, or via the TERM signal.

To make the wallpaper mode work in fvwm3, add to ~/.fvwm/config:

Style * EWMHUseStackingOrderHints
Style gtk4_shadertoy_below WindowListSkip

or, by just

Style gtk4_shadertoy_below StaysOnBottom, Sticky, WindowListSkip

Features & limitations

• a tiny gtk4 app;
• no web browser dependency;
• remote control via a socket;
• -b option crashes the app in Wayland;
• renders only a subset of standalone shaders so far, i.e., if a shader depends on a texture specific to shadertoy.com it won't work.

Compilation

• Fedora:

    $ sudo dnf install gtk4-devel
  

• Ubuntu:

    $ sudo apt-get install libgtk-4-dev
  

then

$ make

_out/gtk4_shadertoy should be the result.

Advanced control

Run in a window, but also accept commands via a socket:

$ gtk4_shadertoy test/data/TAKUSAKU/fire-glass.glsl -p 2023
** Message: 13:56:58.520: Listening on localhost:2023

Then,

$ telnet 127.0.0.1 2023
Trying 127.0.0.1...
Connected to 127.0.0.1.
Escape character is '^]'.
help
200 help; available commands: pause, load file.glsl, quit
pause
200 pause
pause
200 pause
load ~/lib/software/alex/gtk4_shadertoy/test/data/Kali/star-nest.glsl
200 load
quit
200 quit
Connection closed by foreign host.

Remote controlling using netcat:

$ echo load ~/some/file.glsl | nc 127.0.0.1 2023
200 load

A madness tour:

$ while :; do
  echo load `find test/data -type f | shuf | head -1` | nc 127.0.0.1 2023
  sleep 4
done

You can add the echo load ... line to a crontab.

Fetching a shader without an API key

$ npm -g i json
$ ./shader_fetch tsBfDw | _out/gtk4_shadertoy

or

$ ./shader_fetch https://www.shadertoy.com/view/tsBfDw | _out/gtk4_shadertoy

License

MIT for gtk4_shadertoy.c & x11.[ch].

gtkshadertoy.[ch] are ripped from gtk4-demo app and are LGPLv2.1+.

test/data/* files are downloaded form shadertoy.com.