Code covered by the BSD License

### Highlights fromgeom2d

from geom2d by David Legland
Geometry library for matlab. Performs geometric computations on points, lines, circles, polygons...

drawEdge(varargin)
```function varargout = drawEdge(varargin)
%DRAWEDGE Draw an edge given by 2 points
%
%   drawEdge(x1, y1, x2, y2);
%   draw an edge between the points (x1 y1) and  (x2 y2).
%
%   drawEdge([x1 y1 x2 y2]) ;
%   drawEdge([x1 y1], [x2 y2]);
%   specify data either as bundled edge, or as 2 points
%
%   The function supports 3D edges:
%   drawEdge([x1 y1 z1 x2 y2 z2]);
%   drawEdge([x1 y1 z1], [x2 y2 z2]);
%   drawEdge(x1, y1, z1, x2, y2, z2);
%
%   Arguments can be single values or array of size [N*1]. In this case,
%   the function draws multiple edges.
%
%   H = drawEdge(..., OPT), with OPT being a set of pairwise options, can
%   specify color, line width and so on...
%
%   H = drawEdge(...) return handle(s) to created edges(s)
%
%   edges2d, drawCenteredEdge, drawLine
%
%   ---------
%   author : David Legland
%   INRA - TPV URPOI - BIA IMASTE
%   created the 31/10/2003.
%

%   HISTORY
%   19/02/2004 add support for arrays of edges.
%   31/03/2004 change format of edges to [P1 P2] and variants.
%   28/11/2004 add support for 3D edges
%   01/08/2005 add support for drawing options
%   31/05/2007 update doc, and code makeup
%   03/08/2010 re-organize code

% separate edge and optional arguments
[ax edge options] = parseInputArguments(varargin{:});

% draw the edges
if size(edge, 2) == 4
h = drawEdge_2d(ax, edge, options);
else
h = drawEdge_3d(ax, edge, options);
end

% eventually return handle to created edges
if nargout > 0
varargout = {h};
end

function h = drawEdge_2d(ax, edge, options)

h = -1 * ones(size(edge, 1), 1);

for i = 1:size(edge, 1)
if isnan(edge(i,1))
continue;
end

h(i) = plot(ax, edge(i, [1 3]), edge(i, [2 4]), options{:});
end

function h = drawEdge_3d(ax, edge, options)

h = -1 * ones(size(edge, 1), 1);

for i = 1:size(edge, 1)
if isnan(edge(i,1))
continue;
end

h(i) = plot3(ax, edge(i, [1 4]), edge(i, [2 5]), edge(i, [3 6]), options{:});
end

function [ax edge options] = parseInputArguments(varargin)

% extract handle of axis to draw on
if isscalar(varargin{1}) && ishandle(varargin{1})
ax = varargin{1};
varargin(1) = [];
else
ax = gca;
end

% find the number of arguments defining edges
nbVal = 0;
for i = 1:length(varargin)
if isnumeric(varargin{i})
nbVal = nbVal+1;
else
% stop at the first non-numeric value
break;
end
end

% extract drawing options
options = varargin(nbVal+1:end);

% ensure drawing options have correct format
if length(options) == 1
options = [{'color'}, options];
end

% extract edges characteristics
switch nbVal
case 1
% all parameters in a single array
edge = varargin{1};

case 2
% parameters are two points, or two arrays of points, of size N*2.
p1 = varargin{1};
p2 = varargin{2};
edge = [p1 p2];

case 4
% parameters are 4 parameters of the edge : x1 y1 x2 and y2
edge = [varargin{1} varargin{2} varargin{3} varargin{4}];

case 6
% parameters are 6 parameters of the edge : x1 y1 z1 x2 y2 and z2
edge = [varargin{1} varargin{2} varargin{3} varargin{4} varargin{5} varargin{6}];

otherwise
error('drawEdge:WrongNumberOfParameters', 'Wrong number of parameters');
end
```