Implement cast_ray_predicate to allow filtering the colliders with a function

[Affinator]

As I was writing a xpbd backend for bevy_mod_picking, I found that a ray cast with a predicate was missing to implement the functionality efficiently.

I was inspired by the predicate from bevy_rapier: https://github.com/dimforge/bevy_rapier/blob/c6bcce4695d596a7a9c8e91748d4dbb3d31f6d13/src/pipeline/query_filter.rs#L12

Objective

• Implement a ray cast function with the support for a predicate function to filter the colliders

Solution

• Added support for a predicate starting at SpatialQuery and down the pipeline
• I added a small (and fun to play with) example to illustrate one possible use case
• I chose not to change existing functionality. Therefore there is some code duplication in QueryPipelineAsCompositeShapeWithPredicate. This could be unified by introducing an Option in QueryPipelineAsCompositeShape, but that would create breaking changes at many places.

[Affinator]

My branch should now pass all workflows (and I updated it to the current state of main).

[Affinator]

Should i squash the commits or is this fine the way it is?
(Or are there other concerns?)

[Jondolf]

Sorry for responding so late.

I was originally considering a predicate in SpatialQueryFilter like what Rapier does, but I think that would have annoying lifetime issues when used with the RayCaster/ShapeCaster components, so your approach is definitely fine too.

Note that predicates should already work when using ray_hits_callback, but having one for cast_ray is definitely useful and more efficient for the "first hit only" case. I'd like to have cast_shape_predicate and project_point_predicate too if you have time, but leaving them to a follow-up is fine as well.

The example is really fun, but it's a bit confusing in that it only colors one box even though the laser/indicator goes through multiple:

I think it should either color all of the non-glass boxes it hits (using e.g. ray_hits_callback to get many hits) or stop the laser at the first hit (draw it from left to the hit point with gizmos).

No need to squash the commits, I tend to squash merge like Bevy :)

[Affinator]

Hi,
I updated the example to only show the red line until the first hit.

PS: My first approach was also to try to add the predicate to SpatialQueryFilter, but that had the exact problem you described. I therefore chose to do it in a separate function. I understand that this is not ideal, but without a major refactoring this seems to be an acceptable solution.

[Affinator]

OK, so the failed lints are from deprecated methods outside my pull request. Should I rebase on a different branch or can this be merged?

[Jondolf]

I just pushed a quick fix for it here, it was simply a method that was renamed and deprecated in a dependency. I think everything looks good, so I'll merge this once CI passes :)