public boolean wallBlocks(double x0, double y0, double z0, double x1, double y1, double z1) {
		int xx0 = (int) Math.floor(x0 / 16);
		int yy0 = (int) Math.floor(y0 / 16);
		int xx1 = (int) Math.floor(x1 / 16);
		int yy1 = (int) Math.floor(y1 / 16);
		if (xx0 < 0) xx0 = 0;
		if (yy0 < 0) yy0 = 0;
		if (xx1 >= xs) xx1 = xs - 1;
		if (yy1 >= ys) yy1 = ys - 1;

		for (int y = yy0; y <= yy1; y++) {
			for (int x = xx0; x <= xx1; x++) {
				if (tiles[x + y * xs] == 1) return true;
			}
		}
		return false;
	}