void setUp(int width) {
		for (int x = 0; x < width; x++) {
			for (int y = 0; y < width; y++) {
				Square square = squares[x][y];
				if (uniform() < 0.5) {
					square.setDirty(true);
				}
				if (uniform() < 0.1) {
					square.setObstacle(true);
				}
			}
		}
	}