Hello! If you want to edit Krpmon, you should read the license first. 

This file contains information about how this shader is structured.

The "program" subdirectory contains files that are shared across all 3 minecraft dimensions. 
All the files in the world-1, world0 and world1 folders do is include their program/ counterpart.
They also have a #define DIMENSION_whatever directive. This way, if you want something to happen in the overworld only, you can check if DIMENSION_OVERWORLD is defined. 

Most of the lighting is done in gbuffers using the "/global/lighting.glsl" file. 
Composite passes handle post-processing, sky rendering, fog and clouds. You can find information about what each pass does inside the file itself.

Buffer usage:
colortex0: main buffer
colortex1: bloom
colortex2: SMAA main
colortex3: SMAA area
gaux1: Reflections & TAA
colortex5: SMAA search
