code: public static Point tilePlusFineToFull (MisoSceneMetrics metrics,
                                              int tileX, int tileY,
                                              int fineX, int fineY,
                                              Point full)
      {
          int dtx = fineX / metrics.finegran;
          int dty = fineY / metrics.finegran;
          int fx = fineX - dtx * metrics.finegran;
          if (fx < 0) {
              dtx--;
              fx += metrics.finegran;
          }
          int fy = fineY - dty * metrics.finegran;
          if (fy < 0) {
              dty--;
              fy += metrics.finegran;
          }
  
          full.x = toFull(tileX + dtx, fx);
          full.y = toFull(tileY + dty, fy);
          return full;
      }
docs: Adds the supplied fine coordinates to the supplied tile coordinates
  to compute full coordinates.
  
  @return the point object supplied as <code>full</code>.