A common internet debate in some circles is Immediate Mode GUI (IMGUI) vs Retained Mode GUI (RMGUI). Game devs in particular are fond IMGUI. The core

Proving Immediate Mode GUIs are Performant

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2024-05-01 05:30:05

A common internet debate in some circles is Immediate Mode GUI (IMGUI) vs Retained Mode GUI (RMGUI). Game devs in particular are fond IMGUI.

The core argument in favor of IMGUI is that it's super simple and easy. One of the most common arguments against IMGUI is that it's slow and will drain your battery.

My hypothesis is: no, IMGUI is not a battery drain. To test my hypothesis I'm going to measure power draw in a variety of scenarios.

What exactly do "Immediate Mode" and "Retained Mode" mean? Oh boy this is a can of worms. Unfortunately both terms have become confuzzled. They refer to the user API. The implementations can be done in many ways and may or may not contain a wide range of features.

An IMGUI library will likely compute the entire layout when it needs to render. This is what opponents think is expensive and will drain laptop batteries. Here is Dear ImGui's explanation.

An RMGUI library will likely create a scene graph under the hood. The graph will be updated only when something changes. Microsoft on Immediate vs Retained.