## Copyright (C) 2006, 2007  Kai Habel
##
## 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 2, 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, write to the Free
## Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
## 02110-1301, USA.

## -*- texinfo -*-
## @deftypefn {Function File}  shading (@var{type})
## @deftypefnx {Function File}  shading (@var{ax}, ...)
##
## Sets the shading of surface or patch graphic objects. Valid arguments for
## @var{type} are "flat", "interp", or "faceted".
## If @var{ax} is given the shading is applied to axis @var{ax} instead of the 
## current axis.
##
## @example
## shading ("interp")
## @end example
##
## @end deftypefn

## Author: Kai Habel <kai.habel@gmx.de>

function shading (ax, mode)

  if (nargin == 1)
    mode = ax;
    ax = gca ();
  end

  if (nargin != 1 && nargin != 2)
    print_usage ();
  endif

  h1 = findobj (ax, "type", "patch");
  h2 = findobj (ax, "type", "surface");

  obj = [h1, h2];

  for n = 1:numel(obj)
    h = obj(n); 
    if (strcmp (mode, "flat"))
      set (h, "facecolor", "flat");
      set (h, "edgecolor", "none");
    elseif (strcmp (mode, "interp"))
      set (h, "facecolor", "interp");
      set (h, "edgecolor", "none");
    elseif (strcmp (mode, "faceted"))
      set (h, "facecolor", "flat");
      set (h, "edgecolor", [0 0 0]);
    else
      error ("unknown argument");
    endif
  endfor

endfunction