Rogue Door Connection logic

Question

I'm having a bit of trouble developing code to figure out which doors connect in Rogue which is written in c. Not the actual path making. I just dont understand how they link to each other.

If rooms have 2 doors each then, while not the cleanest solution, I can connect the first rooms door1 to the second rooms door2 and continue that pattern, finally going around in a loop.

However, say there are 3 doors for one room, then that would break because one door wouldnt connect to anything. The same thing goes for a one door room.

Any help would be appreciated and links to examples would help too.

Thanks

EDIT

I'm not really generating paths right now, its more of the player teleporting to another door. If it were paths then of course it could intersect which takes care of the paths.

Answer 1

Imagine dots are doors and lines are corridors. This is how you can have three doors connected:

There is no reason why you can't link a door to more than one other door. You can have corridors merge at some point.

But oldskool roguelikes didn't even do this; they simply connected random pairs of rooms with corridors, and if they happen to cross into a room, boom, open a door here. This is the reverse process of what you're thinking. You can easily see how, since each corridor creates exactly two doors, this never produces a third door, so the problem never appears.

But why limit yourself to these methods? There is a wealth of possibilities on the PCG wiki. Maze generation alone is a well-studied field and has numerous algorithms.

Answer 2

Here is another way to connect rooms with three doors:

1. Make sure the amount of doors in your level is even.
2. Put all your rooms in the not-door'd set
3. Pick two rooms from the not-door'd set
4. Connect them through one of their doors
5. If those rooms still have a door that has no corridor, put them in a partially-door'd set
6. While the not-door'd set is not empty, pick one room from the partially-door'd set and one from the not-door'd and repeat from step 4, otherwise, proceed to next step
7. While the partially-door'd set is not empty, pick two rooms from the partially-door'd and repeat from step 4, otherwise, your done

This should work for rooms with any number of doors; all the rooms should be connected to the labyrinth, but some could be connected to themselves. And you might have issues if you have more than one room that has only one door :P