Hi there! Is there any tutorial to learn how to create overlays and shaders?
Overlays are just regular ol’ png images and then a very small plaintext cfg file that tells RetroArch how to load it. Just open the cfg file of one that looks sort of like what you want and then change the filename to match your custom picture. Note: the controller overlays are much more complex, so if you open up a cfg and it has dozens/hundreds of lines, find another one to work from.
Shaders are a bit more complicated in that they’re actual code but you can still do a lot without learning the languages. The individual shaders are combined and tweaked in the preset files (cgp and glslp), and you can set things like resolution/scale there. Most of the shaders also have parameters put in by the authors that control various aspects, and you can set different values for these parameters from the preset files. Like the overlay cfgs, the preset files are just plaintext