Unsolved How does liquid bounce render its background in the main menu?

[cr0w]

Im trying to find out how tf it works, but I have no idea.
Someone here who can tell me the right class to look in?

[Ali00035]

@cr0w liquidbounce's bg uses shaders

EDIT: Only applies to legacy (1.8.9 and 1.12.2) LB

[notautismatall]

@cr0w

Check out GLSL