New upstream version 4.0.0

1 files changed, 108 insertions, 0 deletions

diff --git a/inst/transformShape.m b/inst/transformShape.m
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+## Copyright (C) 2012-2017 (C) Juan Pablo Carbajal
+## 
+## 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{nshape} = } transformShape (@var{shape}, @var{T})
+## Applies transformation to a shape defined by piecewise smooth polynomials.
+##
+## @var{shape} is a cell where each elements is a 2-by-(poly_degree+1) matrix
+## containing a pair of polynomials.
+##
+## Format of @var{T} can be one of :
+## @example
+## @group
+##  [c] , [a b] , [a b c] or [a b c]
+##  [f]   [d e]   [d e f]    [d e f]
+##                           [0 0 1]
+## @end group
+## @end example
+##
+## @seealso{shape2polygon, plotShape}
+## @end deftypefn
+
+function nshape = transformShape (shape, Trans)
+
+  if size(Trans,1) < 2
+    error("geometry:invalid-input-arg", ...
+                       "Transformation can be 2x1, 2x2, 2x3 or 3x3. See help.");
+  end
+
+  if ~iscell(shape)
+    error("geometry:invalid-input-arg", "Shape must be a cell of 2D polynomials.");
+  end
+
+  A =[];
+  v = [];
+
+  switch size(Trans,2)
+    case 1
+    # Just translation
+      v = Trans;
+
+    case 2
+    # Just linear transformation
+      A = Trans;
+
+    case 3
+    # Affine transform
+      A = Trans(1:2,1:2);
+      v = Trans(1:2,3);
+  end
+
+  nshape = cellfun (@(x)polytransform (x,A,v), shape, 'UniformOutput',false);
+
+endfunction
+
+function np = polytransform(p,A,v)
+
+  np = p;
+  if ~isempty (A)
+    np = A*np;
+  end
+  if ~isempty (v)
+    np(:,end) = np(:,end) + v;
+  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]};
+%! warning ("off", 'geom2d:cw-shape',"local");
+%! A = shapeArea (shape);
+%! T = eye(2)/sqrt(A);
+%! shape = transformShape (shape,T);
+%! T = shapeCentroid (shape)(:);
+%! shape = transformShape (shape,-T + [2; 0]);
+%!
+%! close
+%! plotShape (shape,'-r','linewidth',2);
+%! hold on
+%! for i = 1:9
+%!   T = createRotation (i*pi/5)(1:2,1:2)/exp(0.3*i);
+%!   plotShape (transformShape(shape, T), 'color',rand(1,3),'linewidth',2);
+%! end
+%! hold off
+%! axis image