Just some snippets I am working on while I learn about fragment shaders, mainly by following along with the excellent Book of Shaders.
The GLSL code is designed to be run with the Shader Toy extension for the VS Code editor. That is, they assume that the following uniforms are available: iResolution, iGlobalTime, iDeltaTime, iChannel0-3.
To run the code in another environment, adjust the names of the uniforms.