public void indexPrimes()
      {
      primeIndex = new boolean[ gRef.getGameDefs().getPrimesEnd() + 1 ];
      primeIndex[ 0 ] = false;
      primeIndex[ 1 ] = false;
      primeIndex[ 2 ] = true;
      for( int index = 3; index < primeIndex.length; index++ )
         {
         if( index % 2 == 0 )
            {
            primeIndex[ index ] = false;
            } //end if
         else
            {
            primeIndex[ index ] = true;
            for( int counter = 3; counter < ( gRef.getGameDefs().getPrimesEnd() + 1 ) / 2 && counter < index && primeIndex[ index ] == true; counter += 2 )
               {
               if( index % counter == 0 )
                  {
                  primeIndex[ index ] = false;
                  } //end if
               } //end for
            } //end else
         } //end for
      } //end method indexPrimes