slerp functions for directions (Vec2 and Vec3)

[vveisard]

What problem does this solve or what need does it fill?

Linear interpolation is unsuited for transitioning of directions.

What solution would you like?

I would like a spherical interpolation function (slerp) for Vec2 and Vec3 directions.

Additional context

This is a common feature in existing game engines:
https://docs.godotengine.org/en/stable/classes/class_vector3.html#class-vector3-method-slerp
https://docs.unity3d.com/ScriptReference/Vector3.Slerp.html

[bugsweeper]

Vec2 and Vec3 is part of glam crate, this problem should be solved there, futhermore there is already long living issue

[mweatherley]

@bugsweeper You're right that the vector types are owned by glam, but on the other hand, we could easily implement slerp functions for the Dir2/Dir3 types that we do own, and I think those would be quite useful.