This is good advice. I think I am going to experiment with indicating a perimeter source-tile
Edit: this works! It is an absolute eyesore, and I will likely do some type of post processing on these maps. But? it does work! Here is my results. I am using essentially the same rules from before.
My input tileset:
The newly created ‘perimeter’ tile is the ones with the red P. It completely circumscribes the map. There are no rules explicitly referencing the perimeter tiles, they are only there so the outside of the map is ‘non-empty’.
After running the ruleset:
now hiding the input tiles:
of course there is now a blank border around the entire map, but I think I can load the output json and trim the edges with a script.
Just thinking out loud here: I wish there was a way this little trick was somehow built in, or there was a way to tell the automapper, in the rule’s map properties to ‘act like’ this border is present. It seems like fixing it with this approach is possible, and that way it is also opt-in to it. Something like VirtualBorder : true ?, or EmptyOutsideMap: false ?
I imagine this (not treating outside the map as empty) is desired behavior for a lot of people using this feature.