function out = image_domain(fmc, zMin, zMax, zResolution, xResolution)
% out = image_domain(fmc, zMin, zMax, zResolution, xResolution)
%==========================================================================
% Calculates the distances between the array elements and the specified
% domain pixels assuming a homogeneous media.
%
% Input:
% fmc struct
% zMin [mm]
% zMax [mm]
% zResolution pixels/[mm]
% xResolution pixels/[mm]
%
%
% Output:
% domain struct
%
% Example:
% zMin = 25;
% zMax = 50;
% zResolution = 10;
% xResolution = 2;
% domain = image_domain(fmc, zMin, zMax, zResolution, xResolution);
%==========================================================================
%
%==========================================================================
% Transducer coordinates
transducer = [fmc.x'+0.5*fmc.cfg.ElementXwidthmm*1e-3, zeros(length(fmc.x),1)];
% Pixel coordinates
xRange = interp(transducer(:,1), xResolution);
zRange = linspace(zMin*1e-3,zMax*1e-3, round(zResolution*(zMax-zMin)) )';
pixels = [kron(xRange,ones(length(zRange),1)), ...
repmat(zRange,[length(xRange),1])];
Rx = pdist2(pixels,transducer); % Find distances between pixels and transducer coordinates
% Change Rx from a matrix of distances to number of samples, i.e. indices
% in the Ascans.
Rx = Rx - 0.5 * fmc.cfg.SampleOffset*fmc.cfg.Velocityms/(fmc.cfg.FreqMHz*1e6);
Rx = round(Rx/(fmc.cfg.Velocityms / (fmc.cfg.FreqMHz*1e6)));
out.min = abs(min(Rx(:)));
out.max = 2 * max(Rx(:)) - length(fmc.Ascans);
out.Rx = Rx + out.min + 1;
out.xRange = xRange;
out.zRange = zRange;
end
