code: public int[] calcTileLoc(float[] pos) {
          int tx = (int) Math.floor((pos[0] - m_orig[0]) / m_tileWidth);
          int ty = (int) Math.floor((pos[2] - m_orig[2]) / m_tileHeight);
          return new int[] { tx, ty };
      }
docs: Calculates the tile grid location for the specified world position.
  
  @param pos
  The world position for the query. [(x, y, z)]
  @return 2-element int array with (tx,ty) tile location