%%%% wave_2.ldf
%%%% Created by Laurence D. Finston (LDF) Fri Mar  3 20:46:19 CET 2006

%% * (1) Copyright and License.

%%%% This file is part of GNU 3DLDF, a package for three-dimensional drawing. 
%%%% Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008 The Free Software Foundation 

%%%% GNU 3DLDF 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. 

%%%% GNU 3DLDF 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 GNU 3DLDF; if not, write to the Free Software 
%%%% Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

%%%% GNU 3DLDF is a GNU package.  
%%%% It is part of the GNU Project of the  
%%%% Free Software Foundation 
%%%% and is published under the GNU General Public License. 
%%%% See the website http://www.gnu.org 
%%%% for more information.   
%%%% GNU 3DLDF is available for downloading from 
%%%% http://www.gnu.org/software/3dldf/LDF.html. 
%%%% It is also available from 
%%%% http://www.dante.de/software/ctan/, the Dante www-server  
%%%% and from http://wwwuser.gwdg.de/~lfinsto1, 
%%%% the author's website.  

%%%% Please send bug reports to lfinsto1@gwdg.de
%%%% The mailing list help-3dldf@gnu.org is available for people to 
%%%% ask other users for help.  
%%%% The mailing list info-3dldf@gnu.org is for the maintainer of 
%%%% GNU 3DLDF to send announcements to users. 
%%%% To subscribe to these mailing lists, send an 
%%%% email with ``subscribe <email-address>'' as the subject.  

%%%% The author can be contacted at: 

%%%% Laurence D. Finston 
%%%% c/o The Free Software Foundation, Inc.
%%%% 51 Franklin St, Fifth Floor 
%%%% Boston, MA  02110-1301 
%%%% USA 

%%%% lfinsto1@gwdg.de 
%%%% s246794@stud.uni-goettingen.de 


%% *** (3) Wave form 2.  LDF 2006.03.03.

w := 6.4cm;
h := 4.8cm;

w *= 4;
h *= 4;

w /= 1.1375;
h /= 1.1375;

pen_width := .75mm; 

frame_w := w - .5pen_width;
frame_h := h - .5pen_width;

path frame;
frame := origin -- (frame_w, 0) -- (frame_w, frame_h) 
                -- (0, frame_h) -- cycle;

shift frame (0, -.5frame_h);

picture frame_picture;

beginfig(0); 
draw frame with_pen pencircle scaled (.5mm, .5mm, .5mm);
frame_picture := current_picture;
endfig; 

point p;

path q;

pen medium_pen;
pen thick_pen;

medium_pen := pencircle scaled (.75mm, .75mm);
thick_pen := pencircle scaled (1mm, 1mm);

pickup medium_pen;

picture save_picture;

for k = 0 upto 6:
   r := k + 1;
   for j = 0 upto 19:
      q := null_path;
      beginfig(j + k * 38); 
      	 draw (0,0) -- (frame_w, 0) with_color red;
      	 for i = 16 * k upto 16 * r:
      	     m := i * 360 / 32;
      	     n := .25 * j * sind m;

      	     p := (.25 * i, n); 

      	     q += p;
      	 endfor;
      draw q with_pen thick_pen;
      q += ..;
      draw origin -- (.25 * 16 * k, 0) with_pen thick_pen;
      save_picture := current_picture;
      output current_picture with_projection parallel_x_y;
      clear current_picture;
      clip_to frame;
      output frame_picture with_projection parallel_x_y;
      endfig;

      beginfig(r * 38 - j) ; 
         output save_picture with_projection parallel_x_y;
         clip_to frame;
         output frame_picture with_projection parallel_x_y;
      endfig;
   endfor;
endfor;

verbatim_metapost "end";
end;