%% Copyright (c) 2011, INRA
%% 2004-2011, David Legland <david.legland@grignon.inra.fr>
%% 2011 Adapted to Octave by Juan Pablo Carbajal <carbajal@ifi.uzh.ch>
%%
%% All rights reserved.
%% (simplified BSD License)
%%
%% Redistribution and use in source and binary forms, with or without
%% modification, are permitted provided that the following conditions are met:
%%
%% 1. Redistributions of source code must retain the above copyright notice, this
%%    list of conditions and the following disclaimer.
%%     
%% 2. Redistributions in binary form must reproduce the above copyright notice, 
%%    this list of conditions and the following disclaimer in the documentation
%%    and/or other materials provided with the distribution.
%%
%% THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
%% AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
%% IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
%% ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
%% LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 
%% CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
%% SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 
%% INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
%% CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
%% ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
%% POSSIBILITY OF SUCH DAMAGE.
%%
%% The views and conclusions contained in the software and documentation are
%% those of the authors and should not be interpreted as representing official
%% policies, either expressed or implied, of copyright holder.

%% -*- texinfo -*-
%% @deftypefn {Function File} {@var{len} = } edgeLength (@var{edge})
%% Return length of an edge
%%
%%   L = edgeLength(EDGE);  
%%   Returns the length of an edge, with parametric representation:
%%   [x1 y1 x2 y2].
%%
%%   The function also works for several edges, in this case input is a
%%   [N*4] array, containing parametric representation of each edge, and
%%   output is a [N*1] array containing length of each edge.
%%
%%   @seealso{edges2d, edgeAngle}
%% @end deftypefn

function len = edgeLength(varargin)

  %   TODO : specify norm (euclidian, taxi, ...).

  nargs = length(varargin);
  if nargs == 1
      edge = varargin{1};
      len = sqrt(power(edge(:,3)-edge(:,1), 2) + power(edge(:,4)-edge(:,2), 2));
  end

endfunction

