Rotate marker(arrow) as per user navigation on mapbox maps android

Question

I am working on an application in which I have to rotate an arrow according to the user navigation.

I am using the latest Mapbox SDK.

I have tried with a barrier (calculating using lat & long) but couldn't get success.

I don't have any clue that how can I achieve it.

It(Arrow marker) should be navigated on a predefined polygon path.

Answer 1

I got success in calculate bearing using the below method and rotate the arrow as per user navigation:

float bearingBetweenLocations(LatLng latLng1, LatLng latLng2) {
        double PI = 3.14159;
        double lat1 = latLng1.getLatitude() * PI / 180;
        double long1 = latLng1.getLongitude() * PI / 180;
        double lat2 = latLng2.getLatitude() * PI / 180;
        double long2 = latLng2.getLongitude() * PI / 180;
        double dLon = (long2 - long1);
        double y = Math.sin(dLon) * Math.cos(lat2);
        double x = Math.cos(lat1) * Math.sin(lat2) - Math.sin(lat1)
                * Math.cos(lat2) * Math.cos(dLon);
        double brng = Math.atan2(y, x);
        brng = Math.toDegrees(brng);
        brng = (brng + 360) % 360;

        return (float) brng;
    }

Note: Arrow's head should be pointed towards the up direction like the below image. If it is not then you have to set bearing +/- as per the arrow's direction.