## Copyright (C) 2005, 2007, 2008, 2009 John W. Eaton

 ##

 ## This file is part of Octave.

 ##

 ## Octave 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.

 ##

 ## Octave 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 Octave; see the file COPYING.  If not, see

 ## <http://www.gnu.org/licenses/>.

 ## -*- texinfo -*-

 ## @deftypefn {Function File} {} __go_draw_figure__ (@var{h}, @var{plot_stream}, @var{enhanced}, @var{mono})

 ## Undocumented internal function.

 ## @end deftypefn

 ## Author: jwe

 function __go_draw_figure__ (h, plot_stream, enhanced, mono, output_to_paper, implicit_margin)

   if (nargin < 5)

     output_to_paper = false;

   elseif (nargin < 6)

     ## Gnuplot has implicit margins for some output. For example, for postscript

     ## the margin is 50pts. If not specified asssume 0.

     implicit_margin = 0;

   endif

   if (nargin >= 4 && nargin <= 6)

     htype = get (h, "type");

     if (strcmp (htype, "figure"))

       ## When printing, set paperunits to inches and rely on a listener to convert

       ## the values for papersize and paperposition.

       if (output_to_paper)

 	orig_paper_units = get (h, "paperunits");

 	gpval_term = __gnuplot_get_var__ (h, "GPVAL_TERM");

 	gpval_termoptions = __gnuplot_get_var__ (h, "GPVAL_TERMOPTIONS");

 	unwind_protect

 	  set (h, "paperunits", "inches");

           paper_size = get (h, "papersize");

           paper_position = get (h, "paperposition");

           paper_position = paper_position ./ paper_size([1, 2, 1, 2]);

 	  implicit_margin = implicit_margin ./ paper_size;

 	unwind_protect_cleanup

 	  set (h, "paperunits", orig_paper_units);

 	end_unwind_protect

 	if (strcmp (gpval_term, "postscript")

 	    && ! isempty (strfind (gpval_termoptions, "landscape")))

 	  ## This needed to obtain the expected result.

 	  implicit_margin(2) = -implicit_margin(2);

 	endif

       else

 	implicit_margin = implicit_margin * [1 1];

       endif

       ## Get complete list of children.

       kids = allchild (h);

       nkids = length (kids);

       if (nkids > 0)

 	fputs (plot_stream, "\nreset;\n");

 	fputs (plot_stream, "set autoscale keepfix;\n");

 	fputs (plot_stream, "set origin 0, 0\n");

 	fputs (plot_stream, "set size 1, 1\n");

 	for i = 1:nkids

 	  type = get (kids(i), "type");

 	  switch (type)

 	    case "axes"

 	      ## Rely upon listener to convert axes position to "normalized" units.

 	      orig_axes_units = get (kids(i), "units");

 	      orig_axes_position = get (kids(i), "position");

 	      unwind_protect

 		set (kids(i), "units", "normalized");

 		if (output_to_paper)

 		  axes_position_on_page = orig_axes_position .* paper_position([3, 4, 3 ,4]);

 		  axes_position_on_page(1:2) = axes_position_on_page(1:2) +  paper_position(1:2);

 		  set (kids(i), "position", axes_position_on_page);

 		  __go_draw_axes__ (kids(i), plot_stream, enhanced, mono, implicit_margin);

 		else

 		  ## Return axes "units" and "position" back to their original values.

 		  __go_draw_axes__ (kids(i), plot_stream, enhanced, mono, implicit_margin);

 		endif

 		unwind_protect_cleanup

 		set (kids(i), "units", orig_axes_units);

 		set (kids(i), "position", orig_axes_position);

 	      end_unwind_protect

 	    otherwise

 	      error ("__go_draw_figure__: unknown object class, %s", type);

 	  endswitch

 	endfor

       else

 	fputs (plot_stream, "\nreset; clear;\n");

 	fflush (plot_stream);

       endif

     else

       error ("__go_draw_figure__: expecting figure object, found `%s'",

 	     htype);

     endif

   else

     print_usage ();

   endif    

 endfunction