code: public int getKerning(int char1, int char2) {
          int metrics[] = getMetricsTT(char1);
          if (metrics == null)
              return 0;
          int c1 = metrics[0];
          metrics = getMetricsTT(char2);
          if (metrics == null)
              return 0;
          int c2 = metrics[0];
          return kerning.get((c1 << 16) + c2);
      }
docs: Gets the kerning between two Unicode chars.
  @param char1 the first char
  @param char2 the second char
  @return the kerning to be applied