For more context, immediate mode is much closer to the type of declarative UI popularized by libraries like React. The invariant is that what is displayed on s

For more context, immediate mode is much closer to the type of declarative UI popularized by libraries like React. The invariant is that what is displayed on screen is always a pure function of some state variable(s), and on any input/event, instead of needing to "reach into" some retained object that represents a certain piece of text in a certain pane in a certain window, you just change those state variables and re-render the entire UI from scratch. Sounds expensive, but for a 2D UI on hardware that's designed to do far more complicated things at 60FPS, it's far from the bottleneck. For instance, https://github.com/billsix/pyNuklear/blob/master/demo/overview.py#L305 https://github.com/billsix/pyNuklear/blob/master/demo/overvi... (this function is called repeatedly on each frame) is not significantly different from the example at https://reactjs.org/tutorial/tutorial.html#what-is-react https://reactjs.org/tutorial/tutorial.html#what-is-react ... but it is very different from something like `div = createDiv(); div2 = createDiv(parent=div)` etc. which would be a retained-mode API.