https://www.youtube.com/watch?v=Iq1-TZXz9xo (myhouse.wad)
There is nothing about the data structures ID choose to use in doom that prevent portal shenanigans. ID(John Carmack) just did not implement them.
Crispy and Chocolate Doom are what the community calls "vanilla" Doom, with no enhancements at all.
That said, if you are willing to hex-edit the map data, you can have non-euclidean geometry in vanilla Doom: https://doomwiki.org/wiki/Linguortal
No, I'm not confused. To me, Boom it's pretty close to vanilla. Zdoom and the rest are pretty much another league, closer to Quake/HL than Doom.
https://www.youtube.com/watch?v=Iq1-TZXz9xo (myhouse.wad)
There is nothing about the data structures ID choose to use in doom that prevent portal shenanigans. ID(John Carmack) just did not implement them.