pixel spirit is an interesting way to learn glsl. using a method of tarot cards, can show the input code & the output image. its really nice.
this project is a kha/haxe version. where you can edit & run the shaders.
you can. its limited, so get in touch with the creator to see if there will be another release.
head to pixel spirit deck website
• to add in a ui component so you can shift thru the shaders easier