1  int transformation[(2*19 - 1) * (2*19 - 1)][8];
       2  
       3  const int transformation2[8][2][2] = {
       4    {{1, 0}, {0, 1}},
       5    {{0, 1}, {-1, 0}},
       6    {{-1, 0}, {0, -1}},
       7    {{0, -1}, {1, 0}},
       8    {{0, -1}, {-1, 0}},
       9    {{-1, 0}, {0, 1}},
      10    {{0, 1}, {1, 0}},
      11    {{1, 0}, {0, -1}}
      12  };
      13  
      14  void
      15  transformation_init (void)
      16  {
      17    int k;
      18    int dx;
      19    int dy;
      20  
      21    for (k = 0; k < 8; k++)
      22      {
      23        for (dy = -19 + 1; dy <= 19 - 1; dy++)
      24  	{
      25  	  for (dx = -19 + 1; dx <= 19 - 1; dx++)
      26  	    {
      27  	      int tx;
      28  	      int ty;
      29  	      do
      30  		{
      31  		  *&tx =
      32  		    transformation2[k][0][0] * (dx) +
      33  		    transformation2[k][0][1] * (dy);
      34  		  *&ty =
      35  		    transformation2[k][1][0] * (dx) +
      36  		    transformation2[k][1][1] * (dy);
      37  		}
      38  	      while (0);
      39  	      transformation[((dy + 19 - 1) * (2 * 19 - 1) +
      40  			      (dx + 19 - 1))][k] = ((tx) * (19 + 1) + (ty));
      41  	    }
      42  	}
      43      }
      44  }