GUI

Game GUIs are written by registering an entity's gui property to a function, or its hud property.

gui draws in window space, where the bottom left corner is [0,0]. hud draws in screen space. In either of these, you can call "render" functions directly.

draw draws in world space, and mum functions can equally be used there.

MUM

The GUI system which ships with Prosperon is called MUM. MUM is a declarative, immediate mode HUD system. While Imgui is designed to make it easy to make editor-like controls, mum is designed to be easy to make video game huds.