%--------------------------------------------
%
% 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 2007-2012 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/>.
%
%--------------------------------------------

\newcount\c@pgfplotslibrarysurf@streamlen

\def\pgfplotslibrarysurf@initstream{%
	% binary doesn't work due to limitations of DVI.
	% We NEED an ASCII encoding.
	%
	\def\pgfplotslibrarysurf@filter@encode{ASCIIHexEncode}%
	\def\pgfplotslibrarysurf@filter@decode{ASCIIHexDecode}%
	\global\c@pgfplotslibrarysurf@streamlen=0 %
}%

\def\pgfplotslibrarysurf@advancestreamlen#1{%
	\global\advance\c@pgfplotslibrarysurf@streamlen by#1\relax
}%

% 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}%
		\pgfplotslibrarysurfusepath
		\endpgfpicture
	}%
	%
	% NOTE : this code was broken due to some driver in pgf. I fixed
	% that and brought the fix with pgfplots.
	%
	% for some reason, dvipdfmx requires to move the XObject
	% declaration out of the current stream.
	% Perhaps I should rephrase and say that for some reason, this appears to be
	% unnecessary for pdftex. 
	%
	% FIXME : this might have N^2 time due to "box-append"!
	\pgfutil@insertatbegincurrentpagefrombox
	{%
		\special{pdf: bxobj @pgfplotsX\pgfplotslibrarysurf@count\space 
			width \the\wd\pgfutil@tempboxa\space height \the\ht\pgfutil@tempboxa}%
		\special{pdf: put @resources 
			% write the pattern resource dictionary of the XObject
			% (only!):
			<< /Pattern << \pgfplots@glob@TMPa >> >> 
		}%
		%
		% no need to add the pattern to the page's resource list!
		% we do not need this:
		%\pgfutil@addpdfresource@patterns{\pgfplots@glob@TMPa}%
		\leavevmode
		\box\pgfutil@tempboxa
		\special{pdf: exobj}%
	}%
	\endgroup
	\special{pdf: uxobj @pgfplotsX\pgfplotslibrarysurf@count\space}%
	\pgfplotsutil@advancestringcounter@global\pgfplotslibrarysurf@count
}

% 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{%
	% it contain the BINARY bytes. But it is ASCII encoded, see docs of ASCIIHexEncode.
	\global\multiply\c@pgfplotslibrarysurf@streamlen by2 % 
	%
	\def\pgfplots@loc@TMPa{%
		% stream length will be computed automatically
		/ShadingType \pgfplotslibrarysurf@type\space
		/BitsPerCoordinate \pgfplotslibrarysurf@bitspercoordinate\space
		/BitsPerComponent \pgfplotslibrarysurf@bitspercomponent\space
		\if5\pgfplotslibrarysurf@type
			/VerticesPerRow \pgfkeysvalueof{/pgfplots/surf shading/cols}
		\else
			/BitsPerFlag 8
		\fi
		/ColorSpace /Device\pgfplotslibrarysurf@colorspace
		/Decode [\pgfplotslibrarysurf@decode]
		\ifpgfplotslibrarysurf@usecolormap
			/Function \pgfkeysvalueof{/pgfplots/surf shading/colormap}
		\fi
		\ifx\pgfplotslibrarysurf@filter@decode\pgfutil@empty
		\else
			/Filter /\pgfplotslibrarysurf@filter@decode\space
		\fi
		/Length \the\c@pgfplotslibrarysurf@streamlen
	}%
	%
	\pgf@process{\pgfpointdiff{\pgfplotslibrarysurf@corner@sw}{\pgfkeysvalueof{/pgfplots/surf shading/anchor}}}%
	\pgf@sys@bp@correct\pgf@x%
	\pgf@sys@bp@correct\pgf@y%
	%
	%\noexpand\pgfutil@insertatbegincurrentpagefrombox
	{%
		\special{pdf: object @pgfplotsShading\pgfplotslibrarysurf@count\space << \pgfplots@loc@TMPa >> 
			stream^^J%
			\pgfplotslibrarysurf@binarystream
			endstream
		}%
		\special{pdf: close @pgfplotsShading\pgfplotslibrarysurf@count\space }%
		\special{pdf: object @pgfplotsPattern\pgfplotslibrarysurf@count\space <<
			/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 @pgfplotsShading\pgfplotslibrarysurf@count
		>>
		}%
		\special{pdf: close @pgfplotsPattern\pgfplotslibrarysurf@count\space }%
	}%
	\edef#1{%
		/pgfplotsSurface\pgfplotslibrarysurf@count\space @pgfplotsPattern\pgfplotslibrarysurf@count
	}%
	%
	% I inlined \pgfsys@setpatterncolored here because it appears to be
	% natural - and in order to bring this driver to PGF 2.00 (which
	% would fail otherwise)
	\pgfsysprotocol@literal{/Pattern cs /pgfplotsSurface\pgfplotslibrarysurf@count\space scn}%
}

\endinput
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