--- /dev/null
+%% Copyright (c) 2007-2011, David Legland <david.legland@grignon.inra.fr>
+%% Copyright (c) 2012, 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{dist} = } distancePointEdge (@var{point}, @var{edge})
+%% @deftypefnx {Function File} {@var{dist} = } distancePointEdge (@dots{}, @var{opt})
+%% @deftypefnx {Function File} {[@var{dist} @var{pos}]= } distancePointEdge (@dots{})
+%% Minimum distance between a point and an edge
+%%
+%% Return the euclidean distance between edge @var{edge} and point @var{point}.
+%% @var{edge} has the form: [x1 y1 x2 y2], and @var{point} is [x y].
+%% If @var{edge} is Ne-by-4 and @var{point} is Np-by-2, then @var{dist} is
+%% Np-by-Ne, where each row contains the distance of each point to all the edges.
+%%
+%% If @var{opt} is true (or equivalent), the optput is cmpatible with the original function:
+%% @table @samp
+%% @item 1
+%% If @var{point} is 1-by-2 array, the result is Ne-by-1 array computed for each edge.
+%% @item 2
+%% If @var{edge} is a 1-by-4 array, the result is Np-by-1 computed for each point.
+%% @item 3
+%% If both @var{point} and @var{edge} are array, they must have the same number of
+%% rows, and the result is computed for each couple @code{@var{point}(i,:),@var{edge}(i,:)}.
+%% @end table
+%%
+%% If the the second output argument @var{pos} is requested, the function also
+%% returns the position of closest point on the edge. @var{pos} is comprised
+%% between 0 (first point) and 1 (last point).
+%%
+%% @seealso{edges2d, points2d, distancePoints, distancePointLine}
+%% @end deftypefn
+
+%% Rewritten to accept different numbers of points and edges.
+%% 2012 - Juan Pablo Carbajal
+
+function [dist, tp] = distancePointEdge(point, edge, opt=[])
+
+ Np = size (point,1);
+ Ne = size (edge,1);
+ edge = edge.';
+
+ % direction vector of each edge
+ dx = edge(3,:) - edge(1,:);
+ dy = edge(4,:) - edge(2,:);
+
+ % compute position of points projected on the supporting line
+ % (Size of tp is the max number of edges or points)
+
+ delta = dx .* dx + dy .* dy;
+ mask = delta < eps;
+ delta(mask) = 1;
+ warning ('off', 'Octave:broadcast');
+ tp = ((point(:, 1) - edge(1, :)) .* dx + (point(:, 2) - edge(2, :)) .* dy) ./ delta;
+ tp(:,mask) = 0;
+
+ % change position to ensure projected point is located on the edge
+ tp(tp < 0) = 0;
+ tp(tp > 1) = 1;
+
+ % coordinates of projected point
+ p0x = (edge(1,:) + tp .* dx);
+ p0y = (edge(2,:) + tp .* dy);
+
+ % compute distance between point and its projection on the edge
+ dist = sqrt((point(:,1) - p0x) .^ 2 + (point(:,2) - p0y) .^ 2);
+
+ warning ('on', 'Octave:broadcast');
+
+ %% backwards compatibility
+ if opt
+ if Np != Ne && (Ne != 1 && Np !=1)
+ error ("geometry:InvalidArgument", ...
+ "Sizes must be equal or one of the inputs must be 1-by-N array.");
+ end
+ if Np == Ne
+ dist = diag(dist)(:);
+ tp = diag(tp)(:);
+ elseif Np == 1
+ dist = dist.';
+ tp = tp.';
+ end
+ end
+
+endfunction
+
+%% Original code
+%%tp = ((point(:, 1) - edge(:, 1)) .* dx + (point(:, 2) - edge(:, 2)) .* dy) ./ delta;
+%%% ensure degenerated edges are correclty processed (consider the first
+%%% vertex is the closest)
+%%if Ne > 1
+%% tp(delta < eps) = 0;
+%%elseif delta < eps
+%% tp(:) = 0;
+%%end
+
+%%% change position to ensure projected point is located on the edge
+%%tp(tp < 0) = 0;
+%%tp(tp > 1) = 1;
+
+%%% coordinates of projected point
+%%p0 = [edge(:,1) + tp .* dx, edge(:,2) + tp .* dy];
+
+%%% compute distance between point and its projection on the edge
+%%dist = sqrt((point(:,1) - p0(:,1)) .^ 2 + (point(:,2) - p0(:,2)) .^ 2);
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