Add a useful package (from Source forge) for octave

[CreaPhase.git] / octave_packages / geometry-1.5.0 / geom2d / drawBezierCurve.m

diff --git a/octave_packages/geometry-1.5.0/geom2d/drawBezierCurve.m b/octave_packages/geometry-1.5.0/geom2d/drawBezierCurve.m
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+%% Copyright (c) 2011, INRA
+%% 2007-2011, David Legland <david.legland@grignon.inra.fr>
+%% 2011 Adapted to Octave by Juan Pablo Carbajal <carbajal@ifi.uzh.ch>
+%%
+%% 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} drawBezierCurve (@var{points})
+%% @deftypefnx {Command} {Function File} drawBezierCurve (@var{pp})
+%% @deftypefnx {Command} {Function File} drawBezierCurve (..., @var{param}, @var{value}, ...)
+%% @deftypefnx {Command} {Function File} {@var{h} =}drawBezierCurve (...)
+%% Draw a cubic bezier curve defined by the control points @var{points}.
+%%
+%% With only one input argument, draws the Bezier curve defined by the 4 control
+%% points stored in @var{points}. @var{points} is either a 4-by-2 array
+%% (vertical concatenation of point coordinates), or a 1-by-8 array (horizotnal
+%% concatenation of point coordinates). The curve could be described by its
+%% polynomial (output of @code{cbezier2poly}) @var{pp}, which should be a 2-by-4
+%% array.
+%%
+%% The optional @var{param}, @var{value} pairs specify additional drawing
+%% parameters, see the @code{plot} function for details. The specific parameter
+%% 'discretization' with an integer associated value defines the amount of
+%% points used to plot the curve. If the output is requiered, the function
+%% returns the handle to the created graphic object.
+%%
+%% @seealso{cbezier2poly, plot}
+%% @end deftypefn
+
+function varargout = drawBezierCurve(points, varargin)
+
+  % default number of discretization steps
+  N = 64;
+
+  % check if discretization step is specified
+  if ~isempty(varargin)
+      [tf idx] = ismember ({'discretization'},{varargin{1:2:end}});
+      if ~isempty(idx)
+        N = varargin{idx+1};
+        varargin(idx:idx+1) = [];
+      end
+  end
+
+  % parametrization variable for bezier (use N+1 points to have N edges)
+  t = linspace(0, 1, N+1);
+  
+  if any(size(points) ~= [2 4])
+    [x y] = cbezier2poly(points,t);
+  else
+    % Got a polynomial description
+    x = polyval(points(1,:),t);
+    y = polyval(points(2,:),t);
+  end
+  
+  % draw the curve
+  h = plot(x, y, varargin{:});
+
+  % eventually return a handle to the created object
+  if nargout > 0
+      varargout = {h};
+  end
+endfunction
+
+%!demo
+%! points = [0 0; 3 1; -2 1; 1 0];
+%! drawBezierCurve(points);
+%! hold on
+%! plot(points([1 4],1),points([1 4],2),'go');
+%! plot(points([2 3],1),points([2 3],2),'rs');
+%! line(points([1 2],1),points([1 2],2),'color','k');
+%! line(points([3 4],1),points([3 4],2),'color','k');
+%! h = drawBezierCurve(points, 'discretization', 6, 'color','r');
+%! hold off
+
+%!shared p
+%! p = [0 0; 3 1; -2 1; 1 0];
+%!error(drawBezier())
+%!error(drawBezier ('discretization'))
+%!error(drawBezier (p, 'discretization', 'a'))
+%!error(drawBezier (p(:)))