This projet is an unfinished game project of mine I started in 2002. It features a hand made .map files (valve hammer) parser and processor, and a bunch of code to display it like a game engine would. it has collision detection, and recently lightmapping, no mesh import, it has a console and a camera pathtrack demo recorder :)
a discussion of the implementation of the lightmapper here: https://motsd1inge.wordpress.com/2016/03/29/light-rendering-2/