function HrepSum = addMinkowskiHrep(HrepOne, HrepTwo, zerotol)
% calculate the Minkowski sum of two polytopes in H-representation
%
% Syntax: Sum = addMinkowskiHrep(HrepOne, HrepTwo)
%
% Please consider using addMinkowskiVrep, because Minkowski addition is
%   only efficiently performed in V-representation.
% 
% See also: convertPolytope, obtainPolytope, addMinkowskiPolytope,
%   addMinkowskiVrep

% The elk-library: convex geometry applied to crystallization modeling.
%   Copyright (C) 2012 Alexander Reinhold
%
% This program is free software: you can redistribute it and/or modify it 
%   under the terms of the GNU General Public License as published by the 
%   Free Software Foundation, either version 3 of the License, or (at your 
%   option) any later version.
%
% This program is distributed in the hope that it will be useful, but 
%   WITHOUT ANY WARRANTY; without even the implied warranty of 
%   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU 
%   General Public License for more details.
%
% You should have received a copy of the GNU General Public License along 
%   with this program.  If not, see <http://www.gnu.org/licenses/>.

if ~exist('zerotol', 'var')
    zerotol = elkZerotol;
end

VrepOne = convertHrepToVrep(HrepOne, zerotol, inf);
VrepTwo = convertHrepToVrep(HrepTwo, zerotol, inf);
VrepSum = addMinkowskiVrep(VrepOne, VrepTwo);
HrepSum = convertVrepToHrep(VrepSum, zerotol);