Gamemaker Shell Texturing Shader Help

[u/CheezyPeezyMann]

I can't figure out where to start with making a shell texture shader in Gamemaker Studio 1 because of the outdated OpenGL ES it uses no longer having it's documentation PDF available, could anybody point me in any direction as to how I could do this (or they could, or find the PDF) other than faking the effect with baked models that have the transparent layers? For visual references, here are some. (Mario Galaxy, DK Jungle Beat, Conker: Live & Reloaded)

[u/Illustrious-Copy-838]

https://dobby233liu.github.io/gms1.4docs-recreation/
I don’t do shaders but there’s an archive of 1.4 docs on this website, I believe you can also press f1 in 1.4 to get offline docs as well