lerp method
Interpolate two locations with planet spherical calculations at the given animation clock value.
Implementation
@override
ILatLng lerp(double t) {
if (interpolator.isStopped) return end;
return interpolator.interpolate(t).copyWith(
markerId: end.markerId,
isStopover: t == 1.0,
markerJson: begin.markerJson,
);
}