drawOrientedBox

DRAWORIENTEDBOX Draw centered oriented rectangle.
   
   Syntax
   drawOrientedBox(BOX)
   drawOrientedBox(BOX, 'PropertyName', propertyvalue, ...)

   Description
   drawOrientedBox(OBOX)
   Draws an oriented rectangle (or bounding box) on the current axis. 
   OBOX is a 1-by-5 row vector containing box center, dimension (length
   and width) and orientation (in degrees): 
   OBOX = [CX CY LENGTH WIDTH THETA].

   When OBOX is a N-by-5 array, the N boxes are drawn.

   drawOrientedBox(AX, ...) 
   Specifies the axis to draw to point in. AX should be a handle to a axis
   object. By default, display on current axis.

   HB = drawOrientedBox(...) 
   Returns a handle to the created graphic object(s). Object style can be
   modified using syntaw like:
   set(HB, 'color', 'g', 'linewidth', 2);

   Example
     % draw an ellipse together with its oriented box
     elli = [30 40 60 30 20];
     figure; 
     drawEllipse(elli, 'linewidth', 2, 'color', 'g');
     hold on
     box = [30 40 120 60 20];
     drawOrientedBox(box, 'color', 'k');
     axis equal;

   See also
   orientedBox, drawPolygon, drawRect, drawBox, drawCenteredEdge

 ------
 Author: David Legland
 e-mail: david.legland@grignon.inra.fr
 Created: 2011-05-09,    using Matlab 7.9.0.529 (R2009b)
 Copyright 2011 INRA - Cepia Software Platform.

0001 function varargout = drawOrientedBox(box, varargin)
0002 %DRAWORIENTEDBOX Draw centered oriented rectangle.
0003 %
0004 %   Syntax
0005 %   drawOrientedBox(BOX)
0006 %   drawOrientedBox(BOX, 'PropertyName', propertyvalue, ...)
0007 %
0008 %   Description
0009 %   drawOrientedBox(OBOX)
0010 %   Draws an oriented rectangle (or bounding box) on the current axis.
0011 %   OBOX is a 1-by-5 row vector containing box center, dimension (length
0012 %   and width) and orientation (in degrees):
0013 %   OBOX = [CX CY LENGTH WIDTH THETA].
0014 %
0015 %   When OBOX is a N-by-5 array, the N boxes are drawn.
0016 %
0017 %   drawOrientedBox(AX, ...)
0018 %   Specifies the axis to draw to point in. AX should be a handle to a axis
0019 %   object. By default, display on current axis.
0020 %
0021 %   HB = drawOrientedBox(...)
0022 %   Returns a handle to the created graphic object(s). Object style can be
0023 %   modified using syntaw like:
0024 %   set(HB, 'color', 'g', 'linewidth', 2);
0025 %
0026 %   Example
0027 %     % draw an ellipse together with its oriented box
0028 %     elli = [30 40 60 30 20];
0029 %     figure;
0030 %     drawEllipse(elli, 'linewidth', 2, 'color', 'g');
0031 %     hold on
0032 %     box = [30 40 120 60 20];
0033 %     drawOrientedBox(box, 'color', 'k');
0034 %     axis equal;
0035 %
0036 %   See also
0037 %   orientedBox, drawPolygon, drawRect, drawBox, drawCenteredEdge
0038 %
0039 % ------
0040 % Author: David Legland
0041 % e-mail: david.legland@grignon.inra.fr
0042 % Created: 2011-05-09,    using Matlab 7.9.0.529 (R2009b)
0043 % Copyright 2011 INRA - Cepia Software Platform.
0044 
0045 % HISTORY
0046 %   2011-07-22 simplifies code
0047 %   2011-10-11 add management of axes handle
0048 
0049 
0050 %% Parses input arguments
0051 
0052 % extract handle of axis to draw on
0053 if isAxisHandle(box)
0054     ax = box;
0055     box = varargin{1};
0056     varargin(1) = [];
0057 else
0058     ax = gca;
0059 end
0060 
0061 if length(varargin) > 4 && sum(cellfun(@isnumeric, varargin(1:4))) == 4
0062     % input given as separate arguments
0063     cx  = box;
0064     cy  = varargin{1};
0065     hl   = varargin{2} / 2;
0066     hw   = varargin{3} / 2;
0067     theta   = varargin{4};
0068     varargin = varargin(5:end);
0069     
0070 else
0071     % input given as packed array
0072     cx  = box(:,1);
0073     cy  = box(:,2);
0074     hl   = box(:,3) / 2;
0075     hw   = box(:,4) / 2;
0076     theta = box(:,5);
0077 end
0078 
0079 
0080 %% Draw each box
0081 
0082 % allocate memory for graphical handle
0083 hr = zeros(length(cx), 1);
0084 
0085 % iterate on oriented boxes
0086 for i = 1:length(cx)
0087     % pre-compute angle data
0088     cot = cosd(theta(i));
0089     sit = sind(theta(i));
0090     
0091     % x and y shifts
0092     lc = hl(i) * cot;
0093     ls = hl(i) * sit;
0094     wc = hw(i) * cot;
0095     ws = hw(i) * sit;
0096 
0097     % coordinates of box vertices
0098     vx = cx(i) + [-lc + ws; lc + ws ; lc - ws ; -lc - ws ; -lc + ws];
0099     vy = cy(i) + [-ls - wc; ls - wc ; ls + wc ; -ls + wc ; -ls - wc];
0100 
0101     % draw polygons
0102     hr(i) = plot(ax, vx, vy, varargin{:});
0103 end
0104 
0105 
0106 %% Format output
0107 
0108 if nargout > 0
0109     varargout = {hr};
0110 end