--- /dev/null
+## Copyright (C) 2002-2012 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/>.
+
+## v = vrml_frame (t, r, ...)
+##
+## t : 3 Translation Default : [0,0,0]
+## r : 3x3 Matrix, or Default : eye(3)
+## 3 Argument for rotv
+## OPTIONS
+## name : size : function : default
+## "scale" : 3 or 1 : Length of frame's branches (including cone) <1>
+## "diam" : 3 or 1 : Diameter of cone's base
+## "col" : 3 or 3x3 : Color of branches (may be stacked vertically) <[3 4 9]/10>
+## "hcol" : 3 or 3x3 : Color of head (may be stacked vertically) <col>
+##
+
+function v = vrml_frame (varargin)
+
+### Test with : frame with R,G,B vectors of len 3,2,1 and cone's diam are .2,
+### .4, .6.
+##
+### vrml_browse (vrml_frame ("scale",[3,2,1],"diam",0.2*[1,2,3],"col",eye(3)));
+
+t = zeros (3,1);
+r = eye(3);
+
+scale = ones (1,3);
+diam = [nan,nan,nan];
+col = [0.3 0.4 0.9];
+hcol = [];
+
+dc = nan(1,3);
+dr = nan(1,3);
+
+######################################################################
+## Read options
+numeric_args = 0;
+args = nargin; # nargin is now a function
+while args && numeric_args<2 && numeric_args<numel(varargin)
+ tmp = varargin{numeric_args + 1};
+ if ischar (tmp), break; end
+ --args;
+ numeric_args++;
+ if numeric_args == 1, t = tmp ;
+ else r = tmp ; break;
+ end
+end
+
+if args
+
+ leftover_args = {varargin{numeric_args+1:end}}; # pos 2.1.39
+
+ verbose = 0;
+
+ ## df = tars (col, hcol, diam, scale, verbose);
+ df = struct ("dc", dc, \ # Diameter of cone (absolute)
+ "dr", dr, \ # Diameter of rod (absolute)
+ "col", col, \ # Color
+ "hcol", hcol, \ # Color of head (if different)
+ "diam", diam, \ # Diameter of cone relative to branch length
+ "scale", scale, \ # Lenght of branches
+ "verbose",verbose);
+ op1 = " col hcol diam scale dc dr ";
+ op0 = " verbose ";
+ s = read_options (leftover_args, "op1",op1,"op0",op0,"default",df,"skipnan",1);
+ dc = s.dc;
+ dr = s.dr;
+ col = s.col;
+ hcol = s.hcol;
+ diam = s.diam;
+ scale = s.scale;
+end
+
+######################################################################
+if isempty (hcol), hcol = col; end
+
+t = t(:); # t : 3x1
+
+if prod (size (r)) == 3, r = rotv (r); end
+
+## col is 3x3 from now on
+if prod (size (col))==3, col = [1;1;1]*col(:)' ; end
+if prod (size (hcol))==3, hcol = [1;1;1]*hcol(:)' ; end
+if prod (size (diam))==1, diam = [1,1,1]*diam ; end
+if prod (size (scale))==1, scale = [1,1,1]*scale ; end
+
+scale = scale(:)' ;
+
+diam = - ones(1,3) * nanmax (scale) / 16;
+rdiam = - ones(1,3) * nanmax (scale) / 32;
+
+sz = [scale; nan*ones(1,3); diam; rdiam] ;
+
+if any (! isnan (dc))
+ ii = find (! isnan (dc));
+ sz(3,ii) = dc(ii);
+end
+if any (! isnan (dr))
+ ii = find (! isnan (dr));
+ sz(4,ii) = dr(ii);
+end
+
+
+## roddiam = min (nze (scale))/12 ;
+## if roddiam, d = roddiam.*scale ; else d = [nan,nan,nan] ; end
+
+## diam = diam.*scale ;
+## d = diam = nan*scale;
+r2 = r;
+n = sqrt (sum (r2.^2));
+r2./= [1;1;1] * n;
+sz(1,:) .*= n;
+sz(3,:) ./= n;
+sz(4,:) ./= n;
+
+tmp = [r2(:,1), null(r2(:,1)')](:,[2,1,3])';
+if det (tmp) < 0, tmp(3,:) *= -1; end
+a1 = vrml_transfo (vrml_arrow(sz(:,1),[col(1,:);hcol(1,:)],0),\
+ [0,0,0],tmp);
+## keyboard
+tmp = [r2(:,2), null(r2(:,2)')](:,[2,1,3])';
+if det (tmp) < 0, tmp(3,:) *= -1; end
+a2 = vrml_transfo (vrml_arrow(sz(:,2),[col(2,:);hcol(2,:)],0),\
+ [0,0,0],tmp);
+
+tmp = [r2(:,3), null(r2(:,3)')](:,[2,1,3])';
+if det (tmp) < 0, tmp(3,:) *= -1; end
+a3 = vrml_transfo (vrml_arrow(sz(:,3),[col(3,:);hcol(3,:)],0),\
+ [0,0,0],tmp);
+
+f0 = vrml_group (a1, a2, a3);
+v = vrml_transfo (f0, t, nan);
+
+
+endfunction
+