code: public int[] MetersToPixels( double mx, double my, int zoom ) {
          double res = Resolution(zoom);
          int px = (int) Math.round((mx + originShift) / res);
          int py = (int) Math.round((my + originShift) / res);
          return new int[]{px, py};
      }
docs: Converts EPSG:900913 to pyramid pixel coordinates in given zoom level
  
  @param mx
  @param my
  @param zoom
  @return