React maybe to a point but in general no. Immediate means you get to decide (or even *forced*) how each and every frame gets drawn. Its opposite is retained GU

React maybe to a point but in general no. Immediate means you get to decide (or even *forced*) how each and every frame gets drawn. Its opposite is retained GUI which means you have a set of data structures that are automagically drawn by the GUI library. Immediate GUI libraries work with functional-like types while retained GUI uses more data-oriented / object oriented types. Immediate mode is imperative, retained mode is declarative. Immediate can offer very low level control and easier combination of various drawing interfaces. Wanna put a button on top of your game canvas? It is basically inserting more code / function calls that just draws the thing in an event loop. However you're again responsible for parsing input (helper functions exist of course) and directing things to correct place yourself. In retained GUI you define you need a canvas such and such place and a button with red borders and a click() callback that gets called automatically. The GUI framework does all the routing and drawing for you. If it doesn't support putting a button over a canvas, you have to do 5x work to customize it and add a new component type. Immediate mode seems the way to go isn't it? But now you have a huge event loop that you have to split and organize. It usually takes weeks to onboard newbies and you have to write everything yourself (with the help of the libraries). If you mess up the organization, you'll have to search what exact bit of code draws what. Refreshing the UI and looks will require many manual modifications rather than a simple stylesheet change. And immediate GUI has no caching implemented. You are responsible for implementing any such thing. Otherwise you'll learn about the thermal and power limits of the system very quickly. At its very core all GUI is immediate. Because a GPU is still a processor. A very special one that's optimized for doing mostly branchless and mostly simple arithmetic but still a processor with a machine code and memory. So all retained GUI libraries have a immediate drawing core.