Sub-worlds

[byorgey]

A crazy idea that just came up in IRC is to have certain cells function as entrances and exits to other sub-worlds. e.g. there could be caves, buildings, ... This seems like it would be fun and could be an easy way to add new stuff to the world without taking up a ton of space.

Concretely I don't think this would be all that hard to add (famous last words, right?). A meta-world will now consist of a collection of worlds, each with an integer ID. A location now consists of a pair of (world id, coordinates). An entrance to another area just stores the location that it links to.

[xsebek]

So to store this we would have sections world₁,world₂,... and entrances Bimap Location Location?

I'd really like to drill through mountains and view the robot. The border tiles of mountain terrain could be the entrances. 🤔

Possibly related:

• could improve the user experience of Add a drill command #143
• could slightly complicate Saving and loading games #50 (but we can design the save format with sub-worlds in mind)

[byorgey]

So to store this we would have sections world1,world2,... and entrances Bimap Location Location?

Well, I think it is up for debate whether the entrances should be a Bimap. That would mean you can always immediately get back to where you came from and the worlds would form a proper undirected graph. Letting it be a simple Map instead of a Bimap opens the possibility for bugs ("oops, I forgot to connect this thing back to that thing...") but also for more interesting topologies, e.g. several worlds connected by a loop, or one-way dungeons (once you go in, the only way out is to fight your way through to the exit...).

[byorgey]

Just thinking about the mechanics of moving between sub-worlds... a simple idea might be to use the down and up directions (well, we already have down but we could add up). So turn down; move would move into a subworld. To be clear, I'm not proposing to make the world 3D, but rather, that every sub-world portal would be specified as being in either the "up" or "down" direction.

Amusingly, when testing this I realized that executing turn down causes a robot to look like the base.

[byorgey]

An important question is how you would be able to see the sub-worlds. Can you view a robot that is in a subworld? Maybe you would have to develop mapping technology first, so you could send in robots to explore (see #98 and #683)? Or maybe you just have to put tank treads on the base and go explore yourself?