Please read https://twobithistory.org/2019/11/06/doom-bsp.html https://twobithistory.org/2019/11/06/doom-bsp.html and https://30fps.net/pages/pvs-portals-and-qu

Please read https://twobithistory.org/2019/11/06/doom-bsp.html https://twobithistory.org/2019/11/06/doom-bsp.html and https://30fps.net/pages/pvs-portals-and-quake/ https://30fps.net/pages/pvs-portals-and-quake/ Also, I think most of the x86 magic was done by Abrash.