--- /dev/null
+## Copyright (C) 2007-2012 Michael Goffioul
+##
+## This file is part of Octave.
+##
+## Octave 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.
+##
+## Octave 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 Octave; see the file COPYING. If not, see
+## <http://www.gnu.org/licenses/>.
+
+## -*- texinfo -*-
+## @deftypefn {Function File} {} hidden (@var{mode})
+## @deftypefnx {Function File} {} hidden ()
+## Manipulation the mesh hidden line removal. Called with no argument
+## the hidden line removal is toggled. The argument @var{mode} can be either
+## 'on' or 'off' and the set of the hidden line removal is set accordingly.
+## @seealso{mesh, meshc, surf}
+## @end deftypefn
+
+function retval = hidden (mode)
+
+ if (nargin == 0)
+ mode = "swap";
+ elseif (nargin == 1);
+ if (ischar (mode))
+ mode = tolower (mode);
+ if (! strcmp (mode, "on") && ! strcmp (mode, "off"))
+ error ("hidden: MODE expected to be 'on' or 'off'");
+ endif
+ else
+ error ("hidden: expecting MODE to be a string");
+ endif
+ else
+ print_usage ();
+ endif
+
+ for h = get (gca (), "children");
+ htype = lower (get (h, "type"));
+ if (strcmp (htype, "surface"))
+ fc = get (h, "facecolor");
+ if ((! ischar (fc) && is_white (fc))
+ || (ischar (fc) && strcmpi (fc, "none")))
+ switch (mode)
+ case "on"
+ set (h, "facecolor", "w");
+ case "off"
+ set (h, "facecolor", "none");
+ case "swap"
+ if (ischar (fc))
+ set (h, "facecolor", "w");
+ mode = "on";
+ else
+ set (h, "facecolor", "none");
+ mode = "off";
+ endif
+ endswitch
+ endif
+ endif
+ endfor
+
+ if (nargout > 0)
+ retval = mode;
+ endif
+
+endfunction
+
+function retval = is_white (color)
+ retval = all (color == 1);
+endfunction