Add a useful package (from Source forge) for octave

[CreaPhase.git] / octave_packages / geometry-1.5.0 / shape2d / shape2polygon.m

diff --git a/octave_packages/geometry-1.5.0/shape2d/shape2polygon.m b/octave_packages/geometry-1.5.0/shape2d/shape2polygon.m
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+++ b/octave_packages/geometry-1.5.0/shape2d/shape2polygon.m
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+## Copyright (c) 2011 Juan Pablo Carbajal <carbajal@ifi.uzh.ch>
+##
+## This program is free software; you can redistribute it and/or modify
+## it under the terms of the GNU General Public License as published by
+## the Free Software Foundation; either version 3 of the License, or
+## (at your option) any later version.
+##
+## This program is distributed in the hope that it will be useful,
+## but WITHOUT ANY WARRANTY; without even the implied warranty of
+## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+## GNU General Public License for more details.
+##
+## You should have received a copy of the GNU General Public License
+## along with this program; if not, see <http://www.gnu.org/licenses/>.
+
+%% -*- texinfo -*-
+%% @deftypefn {Function File} {@var{polygon} = } shape2polygon (@var{shape})
+%% @deftypefnx {Function File} {@var{polygon} = } shape2polygon (@dots{},@var{property},@var{value},@dots{})
+%% Transforms a 2D shape described by piecewise smooth polynomials into a polygon.
+%%
+%% @var{shape} is a n-by-1 cell where each element is a pair of polynomials
+%% compatible with polyval.
+%% @var{polygon} is a k-by-2 matrix, where each row represents a vertex.
+%% The property-value pairs are passed to @code{curve2polyline}.
+%%
+%% @seealso{polygon2shape, curve2poyline}
+%% @end deftypefn
+
+function polygon = shape2polygon (shape, varargin)
+
+  polygon = cell2mat ( ...
+             cellfun (@(x) curve2polyline(x,varargin{:}), shape,'UniformOutput',false) );
+  polygon = simplifypolygon(polygon);
+
+  if size (polygon, 1) == 1
+    polygon(2,1) = polyval (shape{1}(1,:), 1);
+    polygon(2,2) = polyval (shape{1}(2,:), 1);
+  end
+
+endfunction
+
+%!demo
+%! shape = {[-93.172   606.368  -476.054   291.429; ...
+%!           -431.196   637.253    11.085   163.791]; ...
+%!          [-75.3626  -253.2337   457.1678   328.5714; ...
+%!            438.7659  -653.6278    -7.9953   380.9336]; ...
+%!          [-89.5841   344.9716  -275.3876   457.1429; ...
+%!           -170.3613   237.8858     1.0469   158.0765];...
+%!          [32.900  -298.704   145.804   437.143; ...
+%!          -243.903   369.597   -34.265   226.648]; ...
+%!          [-99.081   409.127  -352.903   317.143; ...
+%!            55.289  -114.223   -26.781   318.076]; ...
+%!          [-342.231   191.266   168.108   274.286; ...
+%!            58.870   -38.083   -89.358   232.362]};
+%!
+%! % Estimate a good tolerance
+%! n  = cell2mat(cellfun(@(x)curveval(x,rand(1,10)), shape, 'uniformoutput',false));
+%! dr = (max(n(:,1))-min(n(:,1)))*(max(n(:,2))-min(n(:,2)))*40;
+%! p  = shape2polygon (shape,'tol',dr);
+%!
+%! figure(1)
+%! shapeplot(shape,'-b');
+%! hold on;
+%! drawPolygon (p,'-or');
+%! hold off