ImGui is a bloat-free graphical user interface library for C++. It is portable, renderer agnostic and carries minimal amount of dependencies (only 3 files are needed). It is based on an "immediate" graphical user interface paradigm which allows you to build simple user interfaces with ease.
ImGui is designed to allow programmers to create "content creation" or "debug" tools (as opposed to tools for the average end-user). It favors simplicity and thus lacks certain features normally found in more high-level libraries, such as string localisation.
ImGui outputs vertex buffers and simple command-lists that you can render in your application. Because it doesn't know or touch graphics state directly, you can call ImGui commands anywhere in your code (e.g. in the middle of a running algorithm, or in the middle of your own rendering process). Refer to the sample applications in the examples/ folder for instructions on how to integrate ImGui with your existing codebase.
The Immediate Mode GUI paradigm may at first appear unusual to some users. This is mainly because "Retained Mode" GUIs have been so widespread and predominant. The following links can give you a better understanding about how Immediate Mode GUIs works.
- [A presentation by Rickard Gustafsson and Johannes Algelind](http://www.cse.chalmers.se/edu/year/2011/course/TDA361/Advanced%20Computer%20Graphics/IMGUI.pdf).
- [Jari Komppa's tutorial on building an ImGui library](http://iki.fi/sol/imgui/).
- [Casey Muratori's original video that popularized the concept](https://mollyrocket.com/861).
Developed by [Omar Cornut](http://www.miracleworld.net). The library was developed with the support of [Media Molecule](http://www.mediamolecule.com) and first used internally on the game [Tearaway](http://tearaway.mediamolecule.com).