AnimationVector
A small, mutable, fixed-size holder for the float components an animated value decomposes into — the currency the spring/tween machinery computes on. A scalar animates as one component, a size as two, a color as four.
The get/set operators let callers treat it like an indexed buffer (vector[i]). Concrete shapes are an implementation detail; obtain one via ofSize, which a TypeConverter uses to implement TypeConverter.newVector. The small fixed sizes are backed by plain fields (no FloatArray indirection); larger sizes fall back to an array.