Allow autotiles to auto-transform tiles, per developer config.

[SquiggelSquirrel]

Allows the developer to specify allowed transformations (flip and transpose)
for a given autotile subtile via a new method:

TileSet.autotile_set_subtile_allowed_transformations(id, coord, flags).

Autotiles will try the allowed transformations when searching for a matching
bitmask, and apply a matching transformation to the cell being drawn into.

This allows functioning autotile sets to be created with smaller
textures, as rotated and flipped variants need not be included.

[SquiggelSquirrel]

Proposal: godotengine/godot-proposals#893

[groud]

It seems like a good idea to me. I guess the feature could make sense for 3.x.

[boruok]

@akien-mga any chance to merge in next beta?

[filipworksdev]

If anyone is interested I added this PR into my custom build of Godot 3.x and you can download test builds from here. The test builds are generated by Github so are safe to run and even use in production but are not signed.

[MystMagus]

I did some work on this (sorry if the links aren't enough, haven't used github much, tell me if I need to do something else), https://github.com/MystMagus/godot/tree/autotile-rotate-missing-property https://github.com/MystMagus/godot/tree/autotile-rotate-editor
The later especially is work on enabling the feature in the editor, though it's a bit sloppy since it was only for my personal use. I made a pr of the first branch (which is just a small fix) but the author doesn't seem to be active on it at the moment.

[SquiggelSquirrel]

@MystMagus I've merged in the PR for the missing property, but I don't really plan to do more work on this if it's just going to be made obsolete by Godot 4.0 in less than a year.

[MystMagus]

@SquiggelSquirrel Oh? Are they changing something in relation to tiles/autotiling?

[SquiggelSquirrel]

@MystMagus yep, from what I understand, 4.0 is gonna completely overhaul the tilemap/tileset system. It seems like transforms will be a property of the tile rather than the cell. That would make this whple approach redundant, as it would just be a case of setting up alternative tiles for different transformations. I haven't looked into it too deeply, though, so I might have that confused.