code: public int[] PixelsToTile( int px, int py ) {
          int tx = (int) Math.ceil(px / ((double) tileSize) - 1);
          int ty = (int) Math.ceil(py / ((double) tileSize) - 1);
          return new int[]{tx, ty};
      }
docs: Returns a tile covering region in given pixel coordinates
  
  @param px
  @param py
  @return