Working on an off-shoot to my SlimApp called SlimEngine, with a lot more of a base for a hand-made 3D engine (CPU): https://github.com/HardCoreCodin/SlimEngine

Next-up: Scene selection and interactive manipulations (TRS), then mesh loading and rendering 🙂
I already have most of the code in another project, just cleaning stuff up migrating it into this one. Haven't actually re-constructed the single-header-file variant yet, but the directory-variant works