colepoirier

Alice would this close #1275?

> @colepoirier no, because it doesn't work for sprites. It's significant progress though, thanks for linking them. Cool. Is there a fundamental reason that this system can’t be the single...

If using `InLayer` relations, I believe we could store the z-order of the layers or the effective `Ord` of the `InLayer` relations in a `struct LayerOrder(Vec)`. This allows for easy...

> I wrote up a quick user-implementable workaround for this today: > > ```rust > enum Layer { > Background(i8), > Foreground(i8), > } > > fn update_z_coordinate_based_on_layer(query: Query for...

> I also think sublayers are also critical (at least one layer). These are really critical when working with similar flows in graphics programs IME. I think a sane default...

> I also have the intuition that this effectively a data structure problem that has analogues in different domains, and therefore is perhaps a well-know problem that has an existing...

> It looks like the data structure we should use is something like skip-lists or tries. The obvious just occurred to me: some kind of binary tree.

I came across a user-facing API design I really like [here](https://github.com/dan-fritchman/Layout21/blob/f7ccfc02e78fa9126723d7bcf40533ae8f55eb97/layout21tetris/src/stack.rs#L306-L319): ```rust /// Relative Z-Axis Reference to one Layer `Above` or `Below` another #[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq)] pub...

Oof that is exceedingly suboptimal. Are there any ideas yet for how we might solve this @alice-i-cecile?

@alice-i-cecile that's great! Can you please link to the 'structured approach to plugin definition' issue or discussion?