It would be cool if there was some kind of way to fill all the enclosed but empty spaces in a blueprint with negative space.

So that I can stamp a blueprint onto something else and not have any remainders from before that aren't needed anymore.

I did consider that. I didn't do it originally because I wasn't sure if anyone would find it useful, and also calculating that sounds very difficult.

I will spend some time thinking about the best way to do that.

I think raiguards blueprint tools mod had some stuff to fill in unused space with landfill. That might help.

Thanks for the suggestion, I'll take a look.

That mod simply fills the whole rectangle of the blueprint with tiles. It doesn't do any detection of enclosed spaces.

To clarify, when you say "enclosed empty space", do you mean completely enclosed? For example, like this:

 X X X
 X   X
 X X X

Not like this:

 X X X
 X   X
 X   X

To clarify, when you say "enclosed empty space", do you mean completely enclosed? For example, like this:

 X X X
 X   X
 X X X

Yeah, that's what I meant. Most of my blueprints are city blocks, so they are surrounded by rails.

That mod simply fills the whole rectangle of the blueprint with tiles. It doesn't do any detection of enclosed spaces.

Sorry for misremembering about that.

I guess one way could maybe be a draggable tool where you can select a rectangle and then every tile inside that rectangle that doesn't have an entity on it gets a negative space tile.

I had considered such a tool when first working on the mod, but discarded the idea as being extraneous. However, I have already had a similar need to you, so I think I will add it now.

I could also add an auto fill feature to blueprints, but I think having both would probably be unnecessary, and doing a flood algorithm would be more difficult than simply filling a selected bounding box.

I just released v0.2.0 that includes a new selection tool. It is pretty basic; just adds negative space where it would fit inside the selection, and in the reverse or alt mode deletes any negative space, since I found myself using a deconstruction planner for that frequently.

It lacks a different icon for the shortcut or a tips-and-tricks entry, so if you find anything is a bit rough, let me know and I can try to improve it.