This is a small and simple SFML demo drawing some simple pixel snow to your desktop background. It's a quick hack job to surprise a friend, so don't expect any major software engineering.
Note: While this should in theory compile and work on X11, so far I only got it to work properly on Windows 10 and Windows 11.
Schnee is the German term for snow, so this is really just pixel snow, just with actually wrong casing (it should read Pixelschnee).
You'll need both SFML and CMake.
Create your solution or makefile using CMake:
cmake path/to/source
Then just build the program by opening the generated solution file or run your build tool, e.g. by executing make.
In debug builds, the program will show a regular SFML window. This is intentional.
To actually draw to the desktop background, you'll have to create a release build.
Depending on your build tools, you'll either have to set CMake's CMAKE_BUILD_TYPE variable to Release or pick the Release build option in your IDE.
To set `CMAKE_BUILD_TYPE on the command line:
cmake -DCMAKE_BUILD_TYPE=Release path/to/source/or/build/directory
Simply execute the program. You should see snow falling on your desktop. To stop/end, just hit Windows+F4.
Ending the program won't reset/redraw your background, it will be fine next login (or whenever you change it).