%--------------------------------------------
% $Header: /cvsroot/pgfplots/pgfplots/generic/pgfplots/sys/pgflibrarysurfshading.pgfsys-pdftex.def,v 1.1 2009/06/11 07:14:52 ludewich Exp $
%
% Package pgfplots
%
% Provides a user-friendly interface to create function plots (normal
% plots, semi-logplots and double-logplots).
% 
% It is based on Till Tantau's PGF package.
%
% Copyright 2007/2008 by Christian Feuersänger.
%
% 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/>.
%
%--------------------------------------------


% The lowlevel call for surface shadings. It uses a pattern type 2
% dictionary as fill color and has thus several things to do. This is
% a little bit more complicated than using the '/sh' operator (as
% other pgf shadings do): the surface shading must be positioned
% exactly at the requested coordinates, otherwise it is quite useless.
%
% Since shadings are *not* affected by changes in the canvas
% transformation matrix (shifts, rotations etc), it is necessary to
% pack the shading into a separate xform object which is then rotated
% and translated correctly. 
%
% There is just one more transformation necessary: the shift inside of
% the xform. This shift is done using changes in the canvas
% transformation matrix and it is UNDONE in the /Matrix argument of
% the pattern dictionary. This last step can't be done with the /sh
% operator which is why I am using pattern dictionaries.
\def\pgfplotslibrarysurfdraw{%
	\begingroup
	\setbox\pgfutil@tempboxa=\hbox{%
		\pgfpicture
		\pgfplotssys@do@surfshading@fillpaths\pgfplots@loc@TMPa%
		\global\let\pgfplots@glob@TMPa=\pgfplots@loc@TMPa
		\pgfpathrectanglecorners
			{\pgfplotslibrarysurf@corner@sw}
			{\pgfplotslibrarysurf@corner@ne}%
		\pgfusepath{fill}%
		\endpgfpicture
	}%
	\pdfxform resources{
		/Pattern << \pgfplots@glob@TMPa >> % write the pattern resource dictionary
	}\pgfutil@tempboxa
	\leavevmode
	\pdfrefxform\pdflastxform
	\endgroup
}

% To be used inside of a pgfpicture.
%
% #1: a macro name. The contents of this macro needs to be written
% into the pdf pattern dictionary contained in the pdf resources of
% the current context. The current context is either the current page
% or an xform object.
%
%
\def\pgfplotssys@do@surfshading@fillpaths#1{%
	\immediate\pdfobj stream attr {%
		% stream length will be computed automatically
		/ShadingType \pgfplotslibrarysurf@type\space
		/BitsPerCoordinate \pgfplotslibrarysurf@bitspercoordinate\space
		/BitsPerComponent 16
		\if5\pgfplotslibrarysurf@type
			/VerticesPerRow \pgfkeysvalueof{/pgfplots/surf shading/cols}
		\else
			/BitsPerFlag 8
		\fi
		/ColorSpace /Device\pgfplotslibrarysurf@colorspace
		/Decode [\pgfplotslibrarysurf@decode]
		/Function \pgfkeysvalueof{/pgfplots/surf shading/colormap}
		\ifx\pgfplotslibrarysurf@filter@decode\pgfutil@empty
		\else
			/Filter /\pgfplotslibrarysurf@filter@decode\space
		\fi
	} {%
		\pgfplotslibrarysurf@binarystream
	}%
	\edef\pgfplots@loc@TMPa{\the\pdflastobj}%
	\pgf@process{\pgfpointdiff{\pgfplotslibrarysurf@corner@sw}{\pgfkeysvalueof{/pgfplots/surf shading/anchor}}}%
	\pgf@sys@bp@correct\pgf@x%
	\pgf@sys@bp@correct\pgf@y%
	\immediate\pdfobj {<<
		/Type /Pattern
		/PatternType 2
%		/Matrix [\pgf@pt@aa\space\pgf@pt@ab\space\pgf@pt@ba\space\pgf@pt@bb\space\pgf@sys@tonumber\pgf@pt@x\space\pgf@sys@tonumber\pgf@pt@y]
		% FIXME: INCORPORATE TIKZ CM
		/Matrix [1 0 0 1 \pgf@sys@tonumber\pgf@x\space \pgf@sys@tonumber\pgf@y] %226.533 518.141] 
		%--------------------------------------------------
		% /ExtGState 
		% 	<<
		% 		/LW 2
		% 		/OP true
		% 		/OPM 1
		% 	>>
		%-------------------------------------------------- 
		/Shading \pgfplots@loc@TMPa\space 0 R 
	>>}%
	\edef#1{%
		/pgfpatPlotsurface\pgfplotslibrarysurf@count\space \the\pdflastobj\space 0 R
	}%
	\pgfsys@setpatterncolored{Plotsurface\pgfplotslibrarysurf@count}%
	\pgfplotsutil@advancestringcounter@global\pgfplotslibrarysurf@count
}

\endinput
% vi: ft=tex
