--- /dev/null
+## Copyright (C) 2002 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_cyl(x,...)
+##
+## Makes a cylinder that links x(:,1) to x(:,2)
+##
+## Options :
+##
+## "tran", transparency : Transparency default = 0
+## "col" , col : Color default = [ 0.3 0.4 0.9 ]
+## "rad" , radius : Radius of segments default = 0.05
+## "balls" : Add balls to extremities
+## "brad" : Radius of balls default = rad
+## "emit", bool : Use or not emissiveColor
+## "noemit" : Same as emit,0
+## "arrow" : Last segment is an arrow
+## "hcol", hcol : Set color of the head of the arrow.
+## default = col
+
+function s = vrml_cyl (x,varargin) # pos 2.1.39
+
+rad = 0.05 ;
+tran = 0 ;
+col = [0.3;0.4;0.9] ;
+hcol = nan;
+brad = nan;
+
+verbose = 0 ;
+balls = 0 ;
+emit = 0;
+noemit = nan;
+arrow = 0;
+
+if nargin > 1
+ op1 = " rad tran col hcol brad emit " ;
+ op0 = " verbose balls noemit arrow " ;
+
+ df = tars (rad, tran, col, hcol, verbose, balls, noemit, arrow, brad, \
+ emit);
+
+
+ s = read_options (varargin, "op1",op1,"op0",op0, "default",df); # pos 2.1.39
+
+ rad= s.rad;
+ tran= s.tran;
+ col= s.col;
+ hcol= s.hcol;
+ emit= s.emit;
+ verbose= s.verbose;
+ balls= s.balls;
+ noemit= s.noemit;
+ arrow= s.arrow;
+ brad= s.brad;
+end
+
+if isnan (brad), brad = rad; end
+if !isnan (noemit), emit = ! noemit; end
+if !isnan (hcol), arrow = 1; end
+
+s = "" ;
+
+N = columns (x);
+
+ # Make col 3xN
+if prod (size (col)) == 3, col = col(:); col = col(:, ones(1,N)); end
+if emit, emitcol = col; else emitcol = nan(1,N); end
+if prod (size (tran)) == 1, tran = tran(ones(1,N)); end
+tran(find (tran==0)) = nan ;
+
+for i = 2:N
+ d = x(:,i)-x(:,i-1) ;
+ n = norm(d) ;
+ if n,
+ d = d/n ;
+
+ ax = cross([0,1,0],d') ;
+ an = norm (ax) ;
+ if abs(an)>eps, ax = ax/an ; else ax = [1,0,0] ; end
+ an = acos(d(2)) ;
+
+ t = mean (x(:,[i,i-1])')' ;
+
+ if ! arrow || i != N
+
+ smat = vrml_material (col(:,i-1), emitcol(:,i-1), tran(i-1));
+ # Do a cylinder
+ s = [s,sprintf(["Transform {\n",\
+ " translation %8.3f %8.3f %8.3f\n",\
+ " children [\n",\
+ " Transform {\n",\
+ " rotation %8.3f %8.3f %8.3f %8.3f\n",\
+ " children [\n",\
+ " Shape {\n",\
+ " appearance Appearance {\n",\
+ " %s",\
+ " }\n",\
+ " geometry Cylinder {\n",\
+ " height %8.3f\n",\
+ " radius %8.3f\n",\
+ " }\n",\
+ " }\n",\
+ " ]\n",\
+ " }\n",\
+ " ]\n",\
+ "}\n"],\
+ t,\
+ ax,an,\
+ smat,\
+ n,\
+ rad)];
+ else
+ t = x(:,i-1) ;
+ if isnan (hcol), hcol = col(:,i); end
+ arrowcol = [col(:,i) hcol(1:3)(:)];
+ s = [s,\
+ vrml_transfo(vrml_arrow ([n,nan,2*rad/n,rad/n],arrowcol,emit),\
+ t, ax*an)];
+ end
+ end
+end
+
+if balls,
+ ## "balls on"
+ s = [s, vrml_points(x,"balls","col",col, "rad",brad,"emit",emit)];
+elseif columns(x)>2,
+ # Make a rounded junction
+ s = [s, vrml_points(x(:,2:columns(x)-1),"balls","col",col,"rad",rad, \
+ "emit", emit)];
+end
+
+
+endfunction
+