Animatable for colors

[lynn-lumen]

Objective

• Fixes Add color animation support #12202

Solution

• Implements Animatable for all color types implementing arithmetic operations.
  • the colors returned by Animatables methods are already clamped.
• Adds a color_animation.rs example.
• Implements the *Assign operators for color types that already had the corresponding operators. This is just a 'nice to have' and I am happy to remove this if it's not wanted.

---

Changelog

• bevy_animation now depends on bevy_color.
• LinearRgba, Laba, Oklaba and Xyza implement Animatable.

[lynn-lumen]

Do I need to do anything about these errors? A lot of them seem to be unrelated to this PR

[alice-i-cecile]

No, those appear to be the result of the new Rust version that just shipped this morning. I'll make an issue.

[viridia]

Looks awesome! Can't wait to try it out.

[mockersf]

I think I would prefer the implementation to be in bevy_color. It makes more sense to me for the impl to be on the crate declaring the type, like third party adding types will also impl the trait, they won't pr it in bevy_animation

[alice-i-cecile]

I think I would prefer the implementation to be in bevy_color. It makes more sense to me for the impl to be on the crate declaring the type, like third party adding types will also impl the trait, they won't pr it in bevy_animation

The problem with this is that it explodes bevy_color's dependency count. While it was previously a nice quasi-independent crate, it now needs bevy_ecs, bevy_app and so on. If we decide to go this route, we need to feature flag it (probably off by default).

[viridia]

Could Animatable live somewhere else?

[alice-i-cecile]

Animatable is the core trait of bevy_animation: it makes sense there. We could add a bevy_ecs feature flag on bevy_animation instead though, which would make it so we can rely on it in bevy_color (and make it more useful to the ecosystem as a whole).

[bushrat011899]

Just some minor suggestions, really nice!

[alice-i-cecile]

@solis-lumine-vorago once you can appease CI I'll merge this in :) Looks like some clippy failures.