app lacking when drawing polyline while tracking user on mapbox

[kanikadrgaur]

I am working on an app there I am drawing polyline with user tracking. I user MapBoxView and MGLPolylineFeature. But when tracing user with on delegate "didUpdate userLocation: MGLUserLocation" app starts lacking it shows delay when I drag map also while drawing. I walk around 20 minutes or more. Can any one please help.

Here is the process I follow..

on didUpdate userLocation: MGLUserLocation. I add user's location in an CLLocation array.. and then call it with timer to draw poly line.