SodiumCoreShaderSupport

Enables resourcepacks to replace sodium's shaders, similar to resourcepacks being able to replace vanilla's core shaders.

How to write shaders for sodium?

Sodium shaders are similar to core shaders, but not the same. The base Sodium Shaders can be found here. Sodium Shaders must be in assets/sodium/shaders directory. But you can #import files from assets/minecraft/shaders using the #import directive. The following code will include the file assets/minecraft/shaders/include/test.glsl:

#import <minecraft:include/test.glsl>

I recommend to create custom glsl files, which you can #import in your shaders (in both core shaders and sodium shaders). These files, should contain your main shader "logic". An example shaderpack, which works on both vanilla and sodium, can be found here.