private void generateMapGrassMargin() {

	for (int i = 0; i < mapWidth; i++) {

	    map[i][0] = Tile.grass;
	    map[i][mapHeight - 1] = Tile.grass;

	}

	for (int i = 0; i < mapHeight; i++) {

	    map[0][i] = Tile.grass;
	    map[mapWidth - 1][i] = Tile.grass;

	}

    }