Rotate marker as per user direction on Google Maps V2 Android

Question

I want to rotate marker as per bearing or sensor value received from Accelerometer to show the user where actually he is moving. I have set marker icon and flat value to tru

Answer 1

Im posting this answer because people like me who are searching for a solution related to the above question might find it useful.

So here how i did it.

As @colin said you must enable .flat(true) to rotate markers.

1.For bearing angle i have used the following code.

Here latLng1 - my old location && latLng2 - my new location

private double bearingBetweenLocations(LatLng latLng1,LatLng latLng2) {

        double PI = 3.14159;
        double lat1 = latLng1.latitude * PI / 180;
        double long1 = latLng1.longitude * PI / 180;
        double lat2 = latLng2.latitude * PI / 180;
        double long2 = latLng2.longitude * 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 brng;
    }

2.To rotate marker using above bearing angle i have used this code

Here isMarkerRotating is a boolean value. Add isMarkerRotating = false in OnCreate method

private void rotateMarker(final Marker marker, final float toRotation) {
        if(!isMarkerRotating) {
            final Handler handler = new Handler();
            final long start = SystemClock.uptimeMillis();
            final float startRotation = marker.getRotation();
            final long duration = 2000;

            final Interpolator interpolator = new LinearInterpolator();

            handler.post(new Runnable() {
                @Override
                public void run() {
                    isMarkerRotating = true;

                    long elapsed = SystemClock.uptimeMillis() - start;
                    float t = interpolator.getInterpolation((float) elapsed / duration);

                    float rot = t * toRotation + (1 - t) * startRotation;

                    float bearing =  -rot > 180 ? rot / 2 : rot;

                    marker.setRotation(bearing);

                    if (t < 1.0) {
                        // Post again 16ms later.
                        handler.postDelayed(this, 16);
                    } else {
                        isMarkerRotating = false;
                    }
                }
            });
        }
    }

3.using above code

LatLng oldLocation, newLocaation;

float bearing = (float) bearingBetweenLocations(oldLocation, newLocaation);
rotateMarker(start_marker, bearing);