[Freeciv-Dev] (PR#7350) Map radius change with city size

["Jason Short" <jdorje@xxxxxxxxxxxxxxxxxxxxx>]

<URL: http://rt.freeciv.org/Ticket/Display.html?id=7350 >

I think the generation of the indices is more complicated than it needs
to be.

I think this implementation should work:

  int dist, count = 0;

  for (dist = 0; dist <= CITY_MAP_RADIUS * CITY_MAP_RADIUS + 2; dist++) {
    for (x = 0; x < CITY_MAP_SIZE; x++) {
      for (y = 0; y < CITY_MAP_SIZE; y++) {
        int dx = (x - CITY_MAP_RADIUS);
        int dy = (y - CITY_MAP_RADIUS);

        if (dx * dx + dy * dy == dist) {
          indices[count].x = x;
          indices[count].y = y;
          count++;
        }
      }
    }
  }

This is O(R^4), where R = CITY_MAP_RADIUS (or max city radius).  This is
quite acceptable as a one-time cost.

jason