% This is % pkmakeneutral.mf % % Copyright (C) 1989-92 by Elmar Bartel. % % 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 1, 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, write to the Free Software % Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. % def MakeNeutral(expr White,Black) = if unknown LeftHalft: picture LeftHalf; fi LeftHalf:= Black; cull LeftHalf keeping (1,infinity); addto LeftHalf contour (unitsquare yscaled qs xscaled (qs/2)); cull LeftHalf keeping (2,2); if unknown RightHalf: picture RightHalf; fi RightHalf:= White; cull RightHalf keeping (1,infinity); addto RightHalf contour (unitsquare yscaled qs xscaled (qs/2) shifted (qs/2,0)); cull RightHalf keeping (2,2); NeutralMan:= LeftHalf; addto NeutralMan also RightHalf; enddef;