centeredEdgeToEdge

CENTEREDEDGETOEDGE Convert a centered edge to a two-points edge.

   EDGE = centeredEdgeToEdge(CEDGE)
   Converts an edge represented using center, length and orientation to an
   edge represented using coordinates of end points.

   Example
     % example of conversion on a 'pythagorean' edge
     cedge = [30 40 50 atand(3/4)];
     centeredEdgeToEdge(cedge)
     ans =
         10    25    50    55


   See also
     edges2d, drawCenteredEdge, drawOrientedBox

 ------
 Author: David Legland
 e-mail: david.legland@grignon.inra.fr
 Created: 2012-07-31,    using Matlab 7.9.0.529 (R2009b)
 Copyright 2012 INRA - Cepia Software Platform.

0001 function edge = centeredEdgeToEdge(cedge)
0002 %CENTEREDEDGETOEDGE Convert a centered edge to a two-points edge.
0003 %
0004 %   EDGE = centeredEdgeToEdge(CEDGE)
0005 %   Converts an edge represented using center, length and orientation to an
0006 %   edge represented using coordinates of end points.
0007 %
0008 %   Example
0009 %     % example of conversion on a 'pythagorean' edge
0010 %     cedge = [30 40 50 atand(3/4)];
0011 %     centeredEdgeToEdge(cedge)
0012 %     ans =
0013 %         10    25    50    55
0014 %
0015 %
0016 %   See also
0017 %     edges2d, drawCenteredEdge, drawOrientedBox
0018 %
0019 % ------
0020 % Author: David Legland
0021 % e-mail: david.legland@grignon.inra.fr
0022 % Created: 2012-07-31,    using Matlab 7.9.0.529 (R2009b)
0023 % Copyright 2012 INRA - Cepia Software Platform.
0024 
0025 % length and orientation
0026 len = cedge(:,3);
0027 ori = cedge(:,4);
0028 
0029 % x and y shifts around center
0030 dx = len * cosd(ori) / 2;
0031 dy = len * sind(ori) / 2;
0032 
0033 % coordinates of extremities
0034 edge = [cedge(:,1:2)-[dx dy] cedge(:,1:2)+[dx dy]];