(work-in-progress - requires latest pulls of CEPL and related libraries from github - see below)

With CEPL-SHADERTOY you can create fragment shaders in a Lisp-like DSL (see CEPL and Varjo).

A fragment shader is a GPU function that is called once for every pixel. You can see examples on shadertoy. Here you can do it in Lisp.

To report bugs or submit shaders, please open an issue.

Clone the repo to a quicklisp-visible directory.

NOTE: right now (30 Oct 2016) I am working with a bleeding-edge CEPL repo, which requires pulling it and a number of other repos listed in "clone-cepl.sh"... This will change soon, but until then, quicklisp is probably not going to cut it.

If you are new to CEPL, please read the instructions there. Generally, you must have a working OpenGL environment. Usually loading the drivers will work.

From your REPL, execute the following:

(ql:quickload :cepl-shadertoy)
(in-package :cepl-shadertoy)
(cepl:repl 700 394)
(run-loop)

You should see some funky stuff in the CEPL output window.

• I usually split my Emacs to have two side-by-side windows, with the REPL in the right one. I position the CEPL output window in the upper-right-corner of the screen, and set it to be always on top with the window manager menu. I then load files into the left Emacs window.
• You may need to hit in your REPL to get a prompt!

Load learn.lisp into Emacs. The file is not meant to be compiled as a whole - read it and compile individual shaders as you go using C-c C-c.

This will get you started with some information on how to make shaders in CEPL using Varjo, the Lisp-to-GLSL compiler.

** Status 24 Oct 2016 - Basic shaders work (ones that require no video or audio or mouse support.