%% Copyright (c) 2011, INRA
%% 2004-2011, David Legland <david.legland@grignon.inra.fr>
%% 2011 Adapted to Octave by Juan Pablo Carbajal <carbajal@ifi.uzh.ch>
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%% -*- texinfo -*-
%% @deftypefn {Function File} {@var{line2} = } transformLine (@var{line1}, @var{T})
%% Transform a line with an affine transform.
%%
%%   Returns the line @var{line1} transformed with affine transform @var{T}.
%%   @var{line1} has the form [x0 y0 dx dy], and @var{T} is a transformation
%%   matrix.
%%
%%   Format of @var{T} can be one of :
%%   [a b]   ,   [a b c] , or [a b c]
%%   [d e]       [d e f]      [d e f]
%%                            [0 0 1]
%%
%%   Also works when @var{line1} is a [Nx4] array of double. In this case, @var{line2}
%%   has the same size as @var{line1}. 
%%
%%   @seealso{lines2d, transforms2d, transformPoint}
%% @end deftypefn

function dest = transformLine(line, trans)

  % isolate points
  points1 = line(:, 1:2);
  points2 = line(:, 1:2) + line(:, 3:4);

  % transform points 
  points1 = transformPoint(points1, trans);
  points2 = transformPoint(points2, trans);

  dest = createLine(points1, points2);

endfunction

