This is a source code I recovered via disassembling the example program provided with the subject resources of FdF project.
It's been disassembled and decompiled with help of Ghidra - Reverse Engineering Framework.
To begin with just execute: make all
Usage: ./FdF <filename> [ case_size z_size ]
To close the window just press '5' on the main keyboard (keycode 53)
Hope this helps!)