title: Find set of latitudes and longitudes using user's current latitude, longitude and direction of viewing an object
body: <p>I am building an Android application based on Augmented Reality. The main idea is when user opens up my application, by default device's camera starts in preview mode. Based on user's current GPS location and the direction in which user/camera is facing I want to calculate which are the set of latitudes and longitudes in the range?</p>
  
  <p>Following image explains my scenario very well. I have full set of latitudes and longitudes as drawn all black spots in the figure. Now suppose user is at the center of the circle. Also considering that he is viewing in North direction. If we consider an angle of 45 degree towards North direction. I want to get set of latitudes and longitudes which are coming in this 45 degree viewable area.</p>
  
  <p><img src="https://i.stack.imgur.com/z57By.png" alt="enter image description here"></p>
  
  <p>I am able to get the direction in which user's camera is facing. I am also able to find user's current GPS location. I have full set of latitudes and longitudes stored in my SQLite database. Now I want to calculate is the set of latitudes and longitudes in which user's device camera is facing. </p>
  
  <p>I hope I have explained pretty well here. Its bit urgent if anyone can help on this.</p>
  
  <p>Thanks in advance.</p>