LerpCallback<T> typedef
LerpCallback<T> =
T? Function(T a, T b, double t)
Function signature for linear interpolation.
For example, Color.lerp qualifies as a LerpCallback<Color>.
The callback should have the return type T; the return type
is nullable for compatibility with existing "lerp" methods.
Implementation
typedef LerpCallback<T> = T? Function(T a, T b, double t);