[question] is it possible to provide a pre-populated target image somehow?

[TLINDEN]

In many examples on YT it is suggested to do this in order to force a certain structure. For example one could pre-populate a target image with floor tiles to mark a walkable way or where a certain room shall be.

Is that possible?

Oh, and while I'm at it: the library returns an image. However, in order to use this in a game I don't really need an image but a 2d map of tile types (e.g. walkable, walls/water/holes etc). So it would be required to pass in a list of tile properties along with the initial tileset to the function, which it keeps per every placed tile. Does that make sense?

thanks in advance,
Tom

[TLINDEN]

Update: to show what I mean: This is what I'd need:

So, I need (in this case) closed room[s]. Rooms maybe connected but if they are not, it's fine as well because in my game I have portals.

However, this is what I get currently:

How can I solve this?

[TLINDEN]

So, I tried adding the feature myself, which might be a good opportunity to get deeper into WFC, see TLINDEN@c75a953

However, it's not working yet. I assume I got the slot population wrong somehow?

With this pre-populated output map:

And using this example I get:

:(

[TLINDEN]

Ok, I compared the wave.PossibilitySpace contents after one successful example (examples/islands/) with the content of the pre-populated one:

• Each pre-populated slot has 1 module
• all 4 Adjacency checksums of those slots have the same value (since I pre-populated it with only water tiles)
• all non-pre-populated slots have all 16 modules

I also added a dump function. With the unaltered island example I get this PossibilitySpace on startup: island startup and this one when done. In comparision, I get this space on startup with the island-pre example (which uses pre-population) and this result, which is clearly incomplete.

I really don't get it why it's not working.

Any idea? (example: https://github.com/TLINDEN/go-wfc/tree/main/examples/islands-pre)

[TLINDEN]

Ah, there's the problem: I prepopulate wave.PossibilitySpace with the slots of the setup image. But I set all other slots to any, including the ones neighboring the prepopulated ones. And the loop doesn't look at the prepopulated slots, because they have entropy 1. So, I think, their neighbors do not get a chance to get propagated properly. So in order to get a correct starting map, the propagation needs to run over the whole map once before the actual collapse loop.