Feature request: Allow texture indexing for TextureAtlases built through TextureAtlasBuilder

[Seldom-SE]

Unless I am mistaken, when using a TextureAtlas built with a TextureAtlasBuilder as a tilemap's texture atlas, the Tiles' texture_indexes do not map to the TextureAtlasSprites' indexes of the same texture. This means that attempting to use indexes retrieved through texture_atlas.get_texture_index in a Tile results in unpredictable textures being displayed. And since the order of the sprites in a generated TextureAtlas cannot be known until runtime, using TextureAtlasBuilder with bevy_ecs_tilemap is infeasible. I wrote a simple example to demonstrate this issue: https://github.com/Seldom-SE/bevy_ecs_tilemap-TextureAtlas-demo.

Perhaps a method may be added to LayerBuilder to provide a Handle<TextureAtlas>, so the TextureAtlas's indexing may be used instead. Unfortunately, this could conflict with the material_handle passed into map_query.build_layer.

I am willing to contribute work on this, if it is desired. Thanks!

[MrGVSV]

I actually just made something in my fork of this repo that might help. It adds a TileAtlasBuilder which can be used to generate a TextureAtlas that maintains order of insertion, so it should work with the current system.

If @StarArawn wants something like this merged, I can open a PR. Otherwise, feel free to just copy the TileAtlasBuilder code! I actually published this in its own crate for possibly broader usage and since it might only be tangentially related to this crate's purpose.

[Seldom-SE]

This looks like it could help, thanks! I might use this once I inevitably refactor my level code again.

[MrGVSV]

This looks like it could help, thanks! I might use this once I inevitably refactor my level code again.

@Seldom-SE I actually just published this in its own crate so it can be used in a more general sense (not just for bevy_ecs_tilemap). Feel free to check it out here!

[Seldom-SE]

This is very helpful, thanks! I'm partway transitioned to using it now.

I'll leave this issue open, though, in case they want to come to their own solution.

[StarArawn]

The plan currently is to switch to a texture array. When I do that I can leverage mipmaps(when bevy comes up with a solution for these) and texture filtering. Things that you cannot easily use with an atlas.

[StarArawn]

I'm going to close this as there is now a TileAtlasBuilder! 🎉

[MrGVSV]

I'm going to close this as there is now a TileAtlasBuilder! 🎉

Wow I just realized that it was sneaked in via the rebase in #120. Sorry if you didn't actually want it, had no idea it did that 😅

[StarArawn]

I'm going to close this as there is now a TileAtlasBuilder! 🎉

Wow I just realized that it was sneaked in via the rebase in #120. Sorry if you didn't actually want it, had no idea it did that 😅

It's all good I think its still useful as I'm leaning towards making the texture array stuff all internal and users just use atlases with the API.