while (tile_count < _height_map.size_x * _height_map.size_y * 2 / 3 && cur_height <= highest_height) {
        for (int y = 0; y < _height_map.size_y; y++) {
            for (int x = 0; x < _height_map.size_x; x++) {
                if (GetTileZ(TileXY(x, y)) == cur_height) tile_count++;
            }
        }
        cur_height++;
    }