% CROP_PAD_3D adjusts the size by zero padding or cropping
%
% [ imout ] = crop_pad_3D( img, outsize, varargin)
% 
% Inputs
%   **img                input 3D volume
%   **outsize            size of output volume
%   **fill                  value to fill the padded regions 
% Outputs
%   ++imout               output volume after cropping / padding to size "outsize"
% 
%   Example : 
%       volData = ones(100,100,100)
%       [ volData_out ] = crop_pad_3D( volData, [50,50,200])
%       size(volData_out) == [50,50,200]


%*-----------------------------------------------------------------------*
%|                                                                       |
%|  Except where otherwise noted, this work is licensed under a          |
%|  Creative Commons Attribution-NonCommercial-ShareAlike 4.0            |
%|  International (CC BY-NC-SA 4.0) license.                             |
%|                                                                       |
%|  Copyright (c) 2017 by Paul Scherrer Institute (http://www.psi.ch)    |
%|                                                                       |
%|       Author: CXS group, PSI                                          |
%*-----------------------------------------------------------------------*
% You may use this code with the following provisions:
%
% If the code is fully or partially redistributed, or rewritten in another
%   computing language this notice should be included in the redistribution.
%
% If this code, or subfunctions or parts of it, is used for research in a 
%   publication or if it is fully or partially rewritten for another 
%   computing language the authors and institution should be acknowledged 
%   in written form in the publication: “Data processing was carried out 
%   using the “cSAXS matlab package” developed by the CXS group,
%   Paul Scherrer Institut, Switzerland.” 
%   Variations on the latter text can be incorporated upon discussion with 
%   the CXS group if needed to more specifically reflect the use of the package 
%   for the published work.
%
% A publication that focuses on describing features, or parameters, that
%    are already existing in the code should be first discussed with the
%    authors.
%   
% This code and subroutines are part of a continuous development, they 
%    are provided “as they are” without guarantees or liability on part
%    of PSI or the authors. It is the user responsibility to ensure its 
%    proper use and the correctness of the results.

function [ imout ] = crop_pad_3D( img, outsize, fill)

if nargin < 1
    fprintf('CROP_PAD: adjusts the size by zero padding or cropping\n');
    fprintf('crop_pad(img, outsize)\n');
    return
end

if nargin < 3
    fill = 0;
end

Nout = outsize(1:3);

Nin = size(img);

if all(Nin ==Nout)  % dont do anything if input array size == output size 
    imout = img;
    return
end

center = floor(Nin(1:3)/2)+1;

imout = zeros(outsize,'like',img) + fill;
centerout = floor(Nout/2)+1;

cenout_cen = centerout - center;
imout(max(cenout_cen(1)+1,1):min(cenout_cen(1)+Nin(1),Nout(1)),...
      max(cenout_cen(2)+1,1):min(cenout_cen(2)+Nin(2),Nout(2)),...
      max(cenout_cen(3)+1,1):min(cenout_cen(3)+Nin(3),Nout(3))) ... 
= img(max(-cenout_cen(1)+1,1):min(-cenout_cen(1)+Nout(1),Nin(1)),...
      max(-cenout_cen(2)+1,1):min(-cenout_cen(2)+Nout(2),Nin(2)),...
      max(-cenout_cen(3)+1,1):min(-cenout_cen(3)+Nout(3),Nin(3)));

if ~isreal(img)
    imout = complex(imout);
end

end