--- /dev/null
+## Copyright (C) 2010 Etienne Grossmann <etienne@egdn.net>
+##
+## 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/>.
+
+## s = vrml_Viewpoint (...) - Vrml Viewpoint node
+##
+## s is a string of the form :
+## ------------------------------------------------------------------
+## Viewpoint {
+## eventIn SFBool set_bind
+## exposedField SFFloat fieldOfView 0.785398 # (0,pi)
+## exposedField SFBool jump TRUE
+## exposedField SFRotation orientation 0 0 1 0 # [-1,1],(-pi,pi)
+## exposedField SFVec3f position 0 0 10 # (-,)
+## field SFString description ""
+## eventOut SFTime bindTime
+## eventOut SFBool isBound
+## }
+## ------------------------------------------------------------------
+##
+## Options :
+## All the fields of the node
+##
+## Example : s = vrml_Viewpoint ("location",[0 0 1]);
+##
+## See also : vrml_DirectionalLight
+
+function s = vrml_Viewpoint (varargin)
+
+if mod(nargin,2) != 0, print_usage; end
+
+h = struct (varargin{:});
+
+tpl = struct ("fieldOfView", "%8.3f",\
+ "jump", "%s",\
+ "orientation", "%8.3f %8.3f %8.3f %8.3f",\
+ "orientation0", "%8.3f %8.3f %8.3f %8.3f",\
+ "position", "%8.3f %8.3f %8.3f",\
+ "description", "\"%s\"",\
+ "DEF", "");
+DEF = "";
+defaultPos = [0 0 10];
+
+for [val,key] = h
+ if ! isfield (tpl, key)
+ error (sprintf ("vrml_Viewpoint : unknown field '%s'",key));
+ end
+end
+if isfield (h, "DEF")
+ DEF = h.DEF;
+ h = rmfield (h, "DEF");
+end
+
+if isfield (h, "orientation0")
+
+ o = h.orientation0;
+ if numel (o) == 3
+ o = [o(:)'/norm(o), norm(o)];
+ elseif numel (o) == 4
+ o(4) = sign(o(4)) * rem (abs (o(4)), pi);
+ o = [o(1:3)(:)'/norm(o(1:3)), o(4)];
+ else
+ error ("Option 'orientation0' has size %i, should be 3 or 4", numel(o));
+ endif
+
+ if isfield (h, "position")
+ p = h.position(:);
+ else
+ p = defaultPos(:);
+ end
+
+ h = rmfield (h, "orientation0");
+
+ h.orientation = o;
+ h.position = rotv (o(1:3), o(4))' * p;
+
+elseif isfield (h, "orientation")
+
+ o = h.orientation;
+ if numel (o) == 3
+ o = [o(:)'/norm(o), norm(o)];
+ elseif numel (o) == 4
+ o(4) = sign(o(4)) * rem (abs (o(4)), pi);
+ o = [o(1:3)(:)'/norm(o(1:3)), o(4)];
+ else
+ error ("Option 'orientation' has size %i, should be 3 or 4", numel(o));
+ endif
+ h.orientation = o;
+end
+
+if isfield (h, "position") && numel (h.position) != 3
+ error ("Option 'position' has size %i, should be 3", numel (h.position));
+endif
+
+if isfield (h, "jump")
+ if h.jump
+ h.jump = "TRUE";
+ else
+ h.jump = "FALSE";
+ endif
+endif
+
+body = "";
+for [val, key] = h
+ body = [body,\
+ sprintf(" %-20s %s\n",key, \
+ sprintf (getfield (tpl,key), val))];
+end
+
+s = sprintf ("Viewpoint {\n%s}\n", body);
+if !isempty (DEF)
+ s = ["DEF ", DEF," ",s];
+end
+endfunction
+