%% Copyright (c) 2011, INRA
%% 2010-2011, David Legland <david.legland@grignon.inra.fr>
%% 2011 Adapted to Octave by Juan Pablo Carbajal <carbajal@ifi.uzh.ch>
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%% -*- texinfo -*-
%% @deftypefn {Function File} {@var{box} =} intersectBoxes (@var{box1}, @var{box2})
%% Intersection of two bounding boxes.
%% 
%%   Example
%%
%% @example
%%   box1 = [5 20 5 30];
%%   box2 = [0 15 0 15];
%%   intersectBoxes(box1, box2)
%%   ans = 
%%       5 15 5 15
%% @end example
%%
%% @seealso{boxes2d, drawBox, mergeBoxes}
%% @end deftypefn

function bb = intersectBoxes(box1, box2)

  % unify sizes of data
  if size(box1,1) == 1
      box1 = repmat(box1, size(box2,1), 1);
  elseif size(box2, 1) == 1
      box2 = repmat(box2, size(box1,1), 1);
  elseif size(box1,1) != size(box2,1)
      error('geom2d:Error',"Bad size for inputs.\n");
  end

  % compute extreme coords
  mini = min(box1(:,[2 4]), box2(:,[2 4]));
  maxi = max(box1(:,[1 3]), box2(:,[1 3]));

  % concatenate result into a new box structure
  bb = [maxi(:,1) mini(:,1) maxi(:,2) mini(:,2)];
  
endfunction

%!test
%! box1 = [5 20 10 25];
%! box2 = [0 15 15 20];
%! res  = [5 15 15 20];
%! bb = intersectBoxes(box1, box2);
%! assert (res, bb, 1e-6);
