@wowaname @idiot I tried to write a big ass post like 3 times with all the reasons why game engines get devilishly complicated when dealing with hardware and just the realities of attempting to optimize for worst-case latency.

I don't know. I've spent a lot of time in Quake 1 engine code and GoldSrc (SDK). You can definitely get the idea of the entity system, but it's designed to be an API. I've spent many hours specifically reading the BSP code, the collision code. It's a giant fucking mess of highly optimized code. It's not about being OOP pretty. It actually needs to run fast and it's written that way. It has no concern for the human programmer. It's extremely procedural.