PIXEL SPIRIT is an interesting way to learn GLSL. Using a method of tarot cards, can show the input code & the output image. It's really nice.
Originally created by PATRICIO GONZALEZ VIVO, who is also the creator of the fantastic website THE BOOK OF SHADERS, which helps in learning about FRAGMENT SHADERS in a great way.
This project is a KHA & HAXE interpretation, where you can edit & run the shaders within KODE STUDIO.
You need KODE STUDIO, then simply drag & drop the project folder into it & run the project.
You could use VISUAL STUDIO CODE with the KHA EXTENSION PACK if you so wish, but thats a bit more of a work around to get up & running with KHA.
You can. It's limited, so get in touch with the creator to see if there will be another release.Head to PIXEL SPIRIT DECK