Upstream DebugPickingPlugin from bevy_mod_picking

[skimmedsquare]

Objective

The debug features (DebugPickingPlugin) from bevy_mod_picking were not upstreamed with the rest of the core changes, this PR reintroduces it for usage inside bevy_dev_tools

Solution

Vast majority of this code is taken as-is from bevy_mod_picking aside from changes to ensure compilation and code style, as such @aevyrie was added as the co-author for this change.

Main changes

• multiselection support - the relevant code was explicitly not included in the process of upstreaming the rest of the package, so it also has been omitted here.
• bevy_egui support - the old package had a preference for using bevy_egui instead of bevy_ui if possible, I couldn't see a way to support this in a core crate, so this has been removed.

Relevant code has been added to the bevy_dev_tools crate instead of bevy_picking as it is a better fit and requires a dependency on bevy_ui for drawing debug elements.

Minor changes

• Changed the debug text size from 60 to 12 as the former was so large as to be unreadable in the new example.

Testing

• cargo run -p ci
• Added a new example in dev_tools/picking_debug and visually verified the in-window results and the console messages

[aevyrie]

Might make more sense to put the example in the picking group. That way people looking for the feature will see it. That, or just enable for all picking examples instead of making a standalone example.

[github-actions]

You added a new example but didn't add metadata for it. Please update the root Cargo.toml file.

[skimmedsquare]

Might make more sense to put the example in the picking group. That way people looking for the feature will see it. That, or just enable for all picking examples instead of making a standalone example.

Sounds reasonable - I don't have a strong opinion here, so I'll wait on some other reviewers to chime in before doing this.

[aevyrie]

The code is a bit janky tbh. I'm not sure if it makes sense to store the data as a component instead of just holding a map in a resource. At times like this I really wish bevy UI was immediate mode.

This is probably fine to upstream as-is, but I'm not super pleased with the code quality, which is my own fault.

@alice-i-cecile this is missing the pointer click and drag overlay that the egui version has, because it's such a pita to just draw shapes on the screen in bevy. We really need screen space gizmos (screen space immediate mode line drawing) to do this kind of thing. This also highlights the usefulness of immediate mode UI when you just need to throw text, boxes, and circles on screen with a system, especially in dev tools. This entire feature could be a single system with imgui.

Edit: @skimmedsquare the criticism here is directed at myself, to be clear. Thanks for doing this legwork!

[github-actions]

You added a new example but didn't add metadata for it. Please update the root Cargo.toml file.

[alice-i-cecile]

Just a bit of cleanup to do, but this is almost ready.

[github-actions]

You added a new example but didn't add metadata for it. Please update the root Cargo.toml file.

[skimmedsquare]

Might make more sense to put the example in the picking group. That way people looking for the feature will see it. That, or just enable for all picking examples instead of making a standalone example.

@alice-i-cecile Any thoughts on the suggestion from @aevyrie above? Was waiting on this before fixing the check-missing-examples-in-docs failure

[alice-i-cecile]

Mild preference to move it into the picking group :)

[github-actions]

You added a new example but didn't add metadata for it. Please update the root Cargo.toml file.

[github-actions]

You added a new example but didn't add metadata for it. Please update the root Cargo.toml file.

[alice-i-cecile]

That cleaned up nicely. Thanks!