a quick hack lib to manage filter shaders (createFilterShader) for you in p5.js.
this is a little better than the previous version in that this lets you set uniform values.
the same warnings apply - i don't know any of the javascript common patterns, i just threw a bunch of code together so that i can more easily manage post processing shaders in my local p5.js projects
IMPORTANT: in its current state, this is VERY slow. I would only recommend using it to preview what a bunch of post processing effects would look like.