[Merged by Bors] - Expose mint feature in bevy_math/glam

[harudagondi]

Objective

• Expose mint feature of glam in bevy_math.
• Unblocks Add first class support for spatial audio in bevy harudagondi/bevy_oddio#22
  • oddio::SpatialOptions uses mint types

Solution

• Added features in bevy_math, bevy_internal, bevy
• Updated docs/cargo_features.md

---

Changelog

Added

• mint feature in bevy_math to allow interoperation of glam types with mint-compatible libraries.

[harudagondi]

This is different from #5270 as this is an opt-in feature.

[mockersf]

It would make more sense to me for bevy_oddio to enable the feature on their side.

[DJMcNab]

It would make more sense to me for bevy_oddio to enable the feature on their side.

I don't think that's right, since making users manually keep their glam version up to date seems not optimal.

Why not just expose all of the glam features in bevy_math

I don't think we should filter this feature all the way up to the root - it should be bevy_math exclusive.

[harudagondi]

It would make more sense to me for bevy_oddio to enable the feature on their side.

I'm using Vec3 internally. Also, trying to enable something like "bevy_math/glam/mint", I get this error:

error: failed to parse manifest at `C:\<path to>\bevy_oddio\Cargo.toml`

Caused by:
  feature `bevy_math/glam/mint` in dependency `bevy` is not allowed to contain slashes
  If you want to enable features of a transitive dependency, the direct dependency needs to re-export those features from the `[features]` table.

[mockersf]

What DJMcNab is suggesting is exposing a mint feature (and other glam features) on bevy_math but not bubbling it up to bevy, which I would prefer 👍

I worry about the multiplication of features exposed by Bevy, this suggestion would fix it

[harudagondi]

but not bubbling it up to bevy

Sorry if this is wrong, as I am not really familiar with how rust features work. If my library (e.g. bevy_oddio) directly uses bevy as a dependency, how would I enable mint for bevy_math as a feature? Do I need to reimport bevy_math (with the mint feature) along with bevy?

[mockersf]

Sorry if this is wrong, as I am not really familiar with how rust features work.

It is not wrong, it's just that features in Bevy requires some work/maintenance due to how the crates are organised. As you saw in that PR you need to modify three crates to expose a feature.
In this case, I feel that mint compatibility is not so much a feature of Bevy as a feature of the math layer, that's why it feel not good to me to expose it on Bevy directly. Others may feel differently and it would be OK to them.

If my library (e.g. bevy_oddio) directly uses bevy as a dependency, how would I enable mint for bevy_math as a feature? Do I need to reimport bevy_math (with the mint feature) along with bevy?

Yup, you would have as dependency:

bevy = { version = "0.8", default-features = false, features = ["..."] }
bevy_math = { version = "0.8", features = ["mint"] }

[alice-i-cecile]

This strategy looks good to me now.

[alice-i-cecile]

@harudagondi I'll merge this once a) merge conflicts are resolved and b) you add the new line :)

[alice-i-cecile]

bors r+

[bors]

Pull request successfully merged into main.

Build succeeded:

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