This is a Common Lisp port of the very first part of Lode Vandevenne's excellent Computer Graphics Tutorial, which covers the untextured raycaster example.
My version here still has glitches (as can be seen above) and crashes sometimes as the translation was not as smooth as I foresaw. I hadn't had time to fix it yet because too many other things going on. Maybe (hopefully) I'll get back to it. In the meantime here it is. Have fun!
I've used SBCL, so I have no clue if/how this will work on other Lisps. To run this you'll need quicklisp and lispbuilder-sdl.
If you don't have quicklisp you can find instructions here: https://golems.github.io/motion-grammar-kit/install.html
or here: https://lispcookbook.github.io/cl-cookbook/getting-started.html
Then once into the REPL:
(load "~/quicklisp/setup.lisp")
(ql:quickload :lispbuilder-sdl)
(load "raycaster-untextured")
(raycaster-untextured-main)