%% Copyright (c) 2011, INRA %% 2003-2011, David Legland %% 2011 Adapted to Octave by Juan Pablo Carbajal %% %% 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{line} =} createLine(varargin) %% Create a straight line from 2 points, or from other inputs %% %% Line is represented in a parametric form : [x0 y0 dx dy] %% x = x0 + t*dx %% y = y0 + t*dy; %% %% %% L = createLine(p1, p2); %% Returns the line going through the two given points. %% %% L = createLine(x0, y0, dx, dy); %% Returns the line going through point (x0, y0) and with direction %% vector(dx, dy). %% %% L = createLine(LINE); %% where LINE is an array of 4 values, creates the line going through the %% point (LINE(1) LINE(2)), and with direction given by vector (LINE(3) %% LINE(4)). %% %% L = createLine(THETA); %% Create a polar line originated at (0,0) and with angle THETA. %% %% L = createLine(RHO, THETA); %% Create a polar line with normal theta, and with min distance to origin %% equal to rho. rho can be negative, in this case, the line is the same %% as with CREATELINE(-rho, theta+pi), but the orientation is different. %% %% %% Note: in all cases, parameters can be vertical arrays of the same %% dimension. The result is then an array of lines, of dimensions [N*4]. %% %% NOTE : A line can also be represented with a 1*5 array : %% [x0 y0 dx dy t]. %% whith 't' being one of the following : %% - t=0 : line is a singleton (x0,y0) %% - t=1 : line is an edge segment, between points (x0,y0) and (x0+dx, %% y0+dy). %% - t=Inf : line is a Ray, originated from (x0,y0) and going to infinity %% in the direction(dx,dy). %% - t=-Inf : line is a Ray, originated from (x0,y0) and going to infinity %% in the direction(-dx,-dy). %% - t=NaN : line is a real straight line, and contains all points %% verifying the above equation. %% This seems us a convenient way to represent uniformly all kind of lines %% (including edges, rays, and even point). %% %% NOTE2 : Any line object can be represented using a 1x6 array : %% [x0 y0 dx dy t0 t1] %% the first 4 parameters define the supporting line, %% t0 represent the position of the first point on the line, %% and t1 the position of the last point. %% * for edges : t0 = 0, and t1=1 %% * for straight lines : t0 = -inf, t1=inf %% * for rays : t0=0, t1=inf (or t0=-inf,t1=0 for inverted ray). %% I propose to call these objects 'lineArc' %% %% @seealso{lines2d, createEdge, createRay} %% @end deftypefn function line = createLine(varargin) if length(varargin)==1 % Only one input parameter. It can be : % - line angle % - array of four parameters % TODO : add control for arrays of lines. var = varargin{1}; if size(var, 2)==4 % 4 parameters of the line in a single array. line = var; elseif size(var, 2)==1 % 1 parameter : angle of the line, going through origin. line = [zeros(size(var)) zeros(size(var)) cos(var) sin(var)]; else error('wrong number of dimension for arg1 : can be 1 or 4'); end elseif length(varargin)==2 % 2 input parameters. They can be : % - line angle and signed distance to origin. % - 2 points, then 2 arrays of 1*2 double. v1 = varargin{1}; v2 = varargin{2}; if size(v1, 2)==1 % first param is angle of line, and second param is signed distance % to origin. line = [v1.*cos(v2) v1.*sin(v2) -sin(v2) cos(v2)]; else % first input parameter is first point, and second input is the % second point. line = [v1(:,1), v1(:,2), v2(:,1)-v1(:,1), v2(:,2)-v1(:,2)]; end elseif length(varargin)==3 % 3 input parameters : % first one is a point belonging to the line, % second and third ones are direction vector of the line (dx and dy). p = varargin{1}; line = [p(:,1) p(:,2) varargin{2} varargin{3}]; elseif length(varargin)==4 % 4 input parameters : % they are x0, y0 (point belongng to line) and dx, dy (direction vector % of the line). % All parameters should have the same size. line = [varargin{1} varargin{2} varargin{3} varargin{4}]; else error('Wrong number of arguments in ''createLine'' '); end endfunction %!test %! p1 = [1 1]; %! p2 = [2 3]; %! lin = createLine(p1, p2); %! assert (p1, lin(1,1:2), 1e-6); %! assert (p2-p1, lin(1,3:4), 1e-6); %!test %! p1 = [1 1;1 1]; %! p2 = [2 3;2 4]; %! lin = createLine(p1, p2); %! assert (2, size(lin, 1)); %! assert (p1, lin(:,1:2), 1e-6); %! assert (p2-p1, lin(:,3:4), 1e-6);