The “pattern-filling with tiles” puzzle

Question

I\'ve encountered an interesting problem while programming a random level generator for a tile-based game. I\'ve implemented a brute-force solver for it but it is exponentially

Answer 1

I think I may have a better idea. I didn't test it, but I'm pretty sure it will be faster than a purely brute-force-ish solution for large zones.

First, create an empty set (a "set" being a collection that only contains unique objects) of nodes. This collection will be used to identify which tiles have broken connections that need to be fixed.

Fill the data structures to represent the board with the pieces that are available, using the ones you see the most fit based on your personal criteria with no regard to the correctness of the solution. This will almost certainly lead you to an invalid state, but it's okay for now. Iterate through the board, and find all tiles that have connections leading to nowhere. Add them to the set of broken tiles.

Now, iterate through the set. Change the tiles it refers to by reducing their number of connections (otherwise you could get into an infinite loop) so they have no broken connection, respecting the currently available pieces. Check their neighbors again, and if you broke connections to other tiles, add these to the set of broken ones too.

Once the set of broken connections will be empty, you should have a fine-looking pattern. Note however that it has an important caveat: it might to tend to oversimplify patterns, since the "fixing" phase will always attempt to reduce the number of connections. You may have to be lucky to get interesting patterns since this could be greatly affected by first piece you put on each tile.