맵뷰에 반경을 표시할때

GeoPoint myLocation = getPoint(lat, lng);
 
            Point point = new Point();
            Paint paint = new Paint();           
 
            mapView.getProjection().toPixels(myLocation, point);
          
            int distance = 1000;
            RectF ovel = new RectF(point.x - distance , point.y - distance, point.x + distance, point.y + distance);
 
            paint.setAntiAlias(true);
            paint.setStyle(Paint.Style.FILL);
            paint.setColor(Color.BLUE);
            paint.setAlpha(20);
            canvas.drawOval(ovel, paint);
            paint.setStyle(Paint.Style.STROKE);
            paint.setStrokeWidth(3);
            paint.setColor(Color.BLUE);
            paint.setAlpha(100);
            canvas.drawOval(ovel, paint);

위와같이 반경을 표시합니다. 그러나 맵뷰를 줌, 아웃시 항상 같은범위에 반경이 그려집니다.

실제 설정한 거리데로 반경을그릴려면 어떻게해야하나요?

Projection projection = mapView.getProjection();