include

#include "<path>"

This preprocessor directive is replaced with the contents of the included file.

Absolute imports have a leading slash, and are treated as relative to the top-level shaders/ folder.

Relative imports lack a leading slash, and are treated as relative to the current file.

shaders/overworld/foo

#include "/bar" // includes shaders/bar
#include "bar"  // includes shaders/overworld/bar