Plotting square apertures on Matlab

I want to plot the aperture of two squares that are 70 units apart(centre to centre) and each has a width of 40 units.

I have this code so far. I know that for one square at the origin then aperture=abs(x)<0.5*b I want to modify the formula I have for one square to make it fit for the two square apertures then plot it.

Is my formula for Aperture correct in the code below?

I want to be able to find the fourier transform in 2D of the aperture function

b=40.0;           % Width of slit in nm
delx=100.0;        % Sampling rate in nm
nx=512;         % number of points
x=linspace(-nx*delx/2,(nx-2)*delx/2,nx);
[xx,yy]=meshgrid(x,x);
Aperture=(abs(x-10)< 0.5*b & abs(x-80)<0.5*b);
figure(1);
imagesc(Aperture); 
axis image; colorbar;

This is what my code is giving so far, how can I fix it?