private void setObstacleBoundary(float[][] x) {
		for (int i = 1; i < nx1; i++) {
			for (int j = 1; j < ny1; j++) {
				if (!fluidity[i][j]) {
					if (fluidity[i - 1][j]) {
						x[i][j] = x[i - 1][j];
					} else if (fluidity[i + 1][j]) {
						x[i][j] = x[i + 1][j];
					}
					if (fluidity[i][j - 1]) {
						x[i][j] = x[i][j - 1];
					} else if (fluidity[i][j + 1]) {
						x[i][j] = x[i][j + 1];
					}
				}
			}
		}
	}