[Keyframe]

And then the author provides example where there’s Dear IMGUI which is c++.

[flohofwoe]

Dear ImGui has a very C-style API though, it's just flat a function API wrapped in a namespace, and about the only other C++ feature that's used in the API is default function arguments.

For usage from C code, there's cimgui, which is an automatically generated C-API wrapper:

https://github.com/cimgui/cimgui