--- /dev/null
+## Copyright (C) 2009-2012 Kai Habel
+##
+## 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} {} surfl (@var{x}, @var{y}, @var{z})
+## @deftypefnx {Function File} {} surfl (@var{z})
+## @deftypefnx {Function File} {} surfl (@var{x}, @var{y}, @var{z}, @var{L})
+## @deftypefnx {Function File} {} surfl (@var{x}, @var{y}, @var{z}, @var{L}, @var{P})
+## @deftypefnx {Function File} {} surfl (@dots{}, "light")
+## Plot a lighted surface given matrices @var{x}, and @var{y} from
+## @code{meshgrid} and
+## a matrix @var{z} corresponding to the @var{x} and @var{y} coordinates of
+## the mesh. If @var{x} and @var{y} are vectors, then a typical vertex
+## is (@var{x}(j), @var{y}(i), @var{z}(i,j)). Thus, columns of @var{z}
+## correspond to different @var{x} values and rows of @var{z} correspond
+## to different @var{y} values.
+##
+## The light direction can be specified using @var{L}. It can be
+## given as 2-element vector [azimuth, elevation] in degrees or as 3-element
+## vector [lx, ly, lz].
+## The default value is rotated 45° counter-clockwise from the current view.
+##
+## The material properties of the surface can specified using a 4-element vector
+## @var{P} = [@var{AM} @var{D} @var{SP} @var{exp}] which defaults to
+## @var{p} = [0.55 0.6 0.4 10].
+## @table @asis
+## @item "AM" strength of ambient light
+##
+## @item "D" strength of diffuse reflection
+##
+## @item "SP" strength of specular reflection
+##
+## @item "EXP" specular exponent
+## @end table
+##
+## The default lighting mode "cdata", changes the cdata property to give the
+## impression
+## of a lighted surface. Please note: the alternative "light" mode, which
+## creates a light
+## object to illuminate the surface is not implemented (yet).
+##
+## Example:
+##
+## @example
+## @group
+## colormap (bone (64));
+## surfl (peaks);
+## shading interp;
+## @end group
+## @end example
+## @seealso{surf, diffuse, specular, surface}
+## @end deftypefn
+
+## Author: Kai Habel <kai.habel@gmx.de>
+
+function retval = surfl (varargin)
+
+ [h, varargin] = __plt_get_axis_arg__ ("surfl", varargin{:});
+
+ oldh = gca ();
+ unwind_protect
+ axes (h);
+ newplot ();
+
+ ## Check for lighting type.
+ use_cdata = true;
+ if (ischar (varargin{end}))
+ lstr = varargin{end};
+ if (strncmp (tolower (lstr), "light", 5))
+ warning ("light method not supported (yet), using cdata method instead");
+ ## This can be implemented when light objects are supported.
+ use_cdata = false;
+ elseif (strncmp (tolower (lstr), "cdata", 5))
+ use_cdata = true;
+ else
+ error ("surfl: unknown lighting method");
+ endif
+ varargin(end) = [];
+ endif
+
+ ## Check for reflection properties argument.
+ ##
+ ## r = [ambient light strength,
+ ## diffuse reflection strength,
+ ## specular reflection strength,
+ ## specular shine]
+ if (length (varargin{end}) == 4 && isnumeric (varargin{end}))
+ r = varargin{end};
+ varargin(end) = [];
+ else
+ ## Default values.
+ r = [0.55, 0.6, 0.4, 10];
+ endif
+
+ ## Check for light vector (lv) argument.
+ have_lv = false;
+ if (isnumeric (varargin{end}))
+ len = numel (varargin{end});
+ lastarg = varargin{end};
+ if (len == 3)
+ lv = lastarg;
+ varargin(end) = [];
+ have_lv = true;
+ elseif (len == 2)
+ [lv(1), lv(2), lv(3)] = sph2cart ((lastarg(1) - 90) * pi/180, lastarg(2) * pi/180, 1.0);
+ varargin(end) = [];
+ have_lv = true;
+ endif
+ endif
+
+ tmp = surface (varargin{:});
+ if (! ishold ())
+ set (h, "view", [-37.5, 30],
+ "xgrid", "on", "ygrid", "on", "zgrid", "on", "clim", [0 1]);
+ endif
+
+ ## Get view vector (vv).
+ a = axis;
+ [az, el] = view;
+ [vv(1), vv(2), vv(3)] = sph2cart ((az - 90) * pi/180.0, el * pi/180.0, 1.0);
+ vv /= norm (vv);
+
+ if (!have_lv)
+ ## Calculate light vector (lv) from view vector.
+ Phi = 45.0 / 180.0 * pi;
+ R = [cos(Phi), -sin(Phi), 0;
+ sin(Phi), cos(Phi), 0;
+ 0, 0, 1];
+ lv = (R * vv.').';
+ endif
+
+ vn = get (tmp, "vertexnormals");
+ dar = get (h, "plotboxaspectratio");
+ vn(:,:,1) *= dar(1);
+ vn(:,:,2) *= dar(2);
+ vn(:,:,3) *= dar(3);
+
+ ## Normalize vn.
+ vn = vn ./ repmat (sqrt (sumsq (vn, 3)), [1, 1, 3]);
+ [nr, nc] = size(get(tmp, "zdata"));
+
+ ## Ambient, diffuse, and specular term.
+ cdata = (r(1) * ones (nr, nc)
+ + r(2) * diffuse (vn(:,:,1), vn(:,:,2), vn(:,:,3), lv)
+ + r(3) * specular (vn(:,:,1), vn(:,:,2), vn(:,:,3), lv, vv, r(4)));
+
+ set (tmp, "cdata", cdata ./ sum (r(1:3)));
+
+ unwind_protect_cleanup
+ axes (oldh);
+ end_unwind_protect
+
+ if (nargout > 0)
+ retval = tmp;
+ endif
+
+endfunction
+
+%!demo
+%! clf
+%! [X,Y,Z]=sombrero;
+%! colormap(copper);
+%! surfl(X,Y,Z);
+%! shading interp;
+
+%!demo
+%! clf
+%! [X,Y,Z]=sombrero;
+%! colormap(copper);
+%! [az, el] = view;
+%! surfl(X,Y,Z,[az+225,el],[0.2 0.6 0.4 25]);
+%! shading interp;
+
git://git.creatis.insa-lyon.fr / CreaPhase.git / blobdiff