scaled method
k of the way through this step, 0 none of it and 1 all of it.
Implementation
MapGestureStep scaled(double k) => MapGestureStep(
from: from,
to: from == null ? null : Offset.lerp(from, to, k),
around: around,
zoomBy: zoomBy * k,
turn: turn * k,
tilt: tilt * k,
);