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+% Copyright 2006 by Till Tantau
+%
+% This file may be distributed and/or modified
+%
+% 1. under the LaTeX Project Public License and/or
+% 2. under the GNU Public License.
+%
+% See the file doc/generic/pgf/licenses/LICENSE for more details.
+
+\ProvidesFileRCS $Header: /cvsroot/pgf/pgf/generic/pgf/basiclayer/pgfcoreshade.code.tex,v 1.9 2007/12/10 13:19:32 tantau Exp $
+
+%
+% Parsing functions
+%
+\newdimen\pgf@max
+\newcount\pgf@sys@shading@range@num
+\def\pgf@parsefunc#1{%
+ \edef\temp{{#1}}%
+ \expandafter\pgf@convertrgbstring\temp%
+ \edef\temp{{\pgf@rgbconv}}%
+ \expandafter\pgf@@parsefunc\temp}
+\def\pgf@@parsefunc#1{%
+ \let\pgf@bounds=\pgfutil@empty%
+ \let\pgf@funcs=\pgfutil@empty%
+ \let\pgf@psfuncs=\pgfutil@empty%
+ \let\pgf@encode=\pgfutil@empty%
+ \let\pgf@sys@shading@ranges=\pgfutil@empty%
+ \pgf@sys@shading@range@num=0\relax%
+ \pgf@parsefirst[#1; ]%
+ \pgf@parselastdom[#1; ]%
+ \pgf@parsemid[#1; ]%
+ \ifx\pgf@bounds\pgfutil@empty%
+ \edef\pgf@pdfparseddomain{0 1}%
+ \edef\pgf@pdfparsedfunction{\pgf@singlefunc\space}%
+ \else%
+ \edef\pgf@pdfparseddomain{\pgf@doma\space\pgf@domb}%
+ \edef\pgf@pdfparsedfunction{%
+ << /FunctionType 3 /Domain [\pgf@doma\space\pgf@domb] /Functions
+ [\pgf@funcs\space] /Bounds [\pgf@bounds] /Encode [0 1 \pgf@encode]
+ >> }% <<
+ \fi%
+ \xdef\pgf@psfuncs{\pgf@psfuncs}%
+ }
+\def\pgf@parsefirst[rgb(#1)=(#2,#3,#4)#5]{%
+ \pgfmathsetlength\pgf@x{#1}%
+ \edef\pgf@sys@shading@start@pos{\the\pgf@x}%
+ \pgf@sys@bp@correct\pgf@x%
+ \edef\pgf@doma{\pgf@sys@tonumber{\pgf@x}}%
+ \edef\pgf@prevx{\pgf@sys@tonumber{\pgf@x}}%
+ \pgf@getrgbtuplewithmixin{#2}{#3}{#4}%
+ \edef\pgf@sys@shading@start@rgb{\pgf@sys@rgb}%
+ \let\pgf@sys@prevcolor=\pgf@sys@shading@start@rgb%
+ \let\pgf@sys@prevpos=\pgf@sys@shading@start@pos%
+ \edef\pgf@prevcolor{\pgf@rgb}%
+ \edef\pgf@firstcolor{\pgf@rgb}}
+\def\pgf@parselastdom[rgb(#1)=(#2,#3,#4); {%
+ \pgfutil@ifnextchar]{%
+ \pgfmathsetlength\pgf@x{#1}%
+ \edef\pgf@sys@shading@end@pos{\the\pgf@x}%
+ \pgf@max=\pgf@x\relax%
+ \pgf@sys@bp@correct\pgf@x%
+ \edef\pgf@domb{\pgf@sys@tonumber{\pgf@x}}%
+ \pgf@getrgbtuplewithmixin{#2}{#3}{#4}%
+ \edef\pgf@sys@shading@end@rgb{\pgf@sys@rgb}%
+ \pgfutil@gobble}{\pgf@parselastdom[}}
+\def\pgf@parsemid[rgb(#1)=(#2,#3,#4); {\pgf@parserest[}
+\def\pgf@parserest[rgb(#1)=(#2,#3,#4); {%
+ \advance\pgf@sys@shading@range@num by1\relax%
+ \pgfutil@ifnextchar]{%
+ \pgf@getrgbtuplewithmixin{#2}{#3}{#4}%
+ \edef\pgf@singlefunc{\space%
+ << /FunctionType 2 /Domain [0 1] /C0
+ [\pgf@prevcolor] /C1 [\pgf@rgb] /N 1 >> }% <<
+ \edef\pgf@funcs{\pgf@funcs\space%
+ << /FunctionType 2 /Domain [\pgf@doma\space\pgf@domb] /C0
+ [\pgf@prevcolor] /C1 [\pgf@rgb] /N 1 >> }% <<
+ \edef\pgf@psfuncs{\pgf@prevx\space \pgf@rgb\space \pgf@prevcolor\space pgfshade \pgf@psfuncs}%
+ \pgfmathsetlength\pgf@x{#1}%
+ \edef\pgf@sys@shading@ranges{\pgf@sys@shading@ranges{{\pgf@sys@prevpos}{\the\pgf@x}{\pgf@sys@prevcolor}{\pgf@sys@rgb}}}%
+ \edef\pgf@sys@prevpos{\the\pgf@x}%
+ \let\pgf@sys@prevcolor=\pgf@sys@rgb%
+ \pgfutil@gobble}{%
+ \pgfmathsetlength\pgf@x{#1}%
+ \pgf@getrgbtuplewithmixin{#2}{#3}{#4}%
+ \edef\pgf@sys@shading@ranges{\pgf@sys@shading@ranges{{\pgf@sys@prevpos}{\the\pgf@x}{\pgf@sys@prevcolor}{\pgf@sys@rgb}}}%
+ \edef\pgf@sys@prevpos{\the\pgf@x}%
+ \let\pgf@sys@prevcolor=\pgf@sys@rgb%
+ \edef\pgf@psfuncs{\pgf@prevx\space \pgf@rgb\space \pgf@prevcolor\space pgfshade \pgf@psfuncs}%
+ \pgf@sys@bp@correct\pgf@x%
+ \edef\pgf@prevx{\pgf@sys@tonumber{\pgf@x}}%
+ \edef\pgf@bounds{\pgf@bounds\space\pgf@sys@tonumber{\pgf@x}}%
+ \edef\pgf@encode{\pgf@encode\space0 1}%
+ \edef\pgf@singlefunc{\space%
+ << /FunctionType 2 /Domain [0 1] /C0
+ [\pgf@prevcolor] /C1 [\pgf@rgb] /N 1 >> }% <<
+ \edef\pgf@funcs{\pgf@funcs\space%
+ << /FunctionType 2 /Domain [\pgf@doma\space\pgf@domb] /C0
+ [\pgf@prevcolor] /C1 [\pgf@rgb] /N 1 >> }% <<
+ \edef\pgf@prevcolor{\pgf@rgb}%
+ \pgf@parserest[}}
+
+\def\pgf@getrgbtuplewithmixin#1#2#3{%
+ \pgfutil@definecolor{pgfshadetemp}{rgb}{#1,#2,#3}%
+ \pgfutil@ifundefined{applycolormixins}{}{\applycolormixins{pgfshadetemp}}%
+ \pgfutil@extractcolorspec{pgfshadetemp}{\pgf@tempcolor}%
+ \expandafter\pgfutil@convertcolorspec\pgf@tempcolor{rgb}{\pgf@rgbcolor}%
+ \expandafter\pgf@getrgb@@\pgf@rgbcolor!}
+\def\pgf@getrgb@@#1,#2,#3!{%
+ \def\pgf@rgb{#1 #2 #3}%
+ \def\pgf@sys@rgb{{#1}{#2}{#3}}%
+}
+
+
+\def\pgf@convertrgbstring#1{%
+ \def\pgf@rgbconv{}%
+ \pgf@converttorgb#1]%
+ }
+\def\pgf@converttorgb{%
+ \pgfutil@ifnextchar]{\pgfutil@gobble}%done!
+ {%
+ \pgfutil@ifnextchar;{\pgf@grabsemicolor}%
+ {%
+ \pgfutil@ifnextchar r{\pgf@grabrgb}%
+ {%
+ \pgfutil@ifnextchar g{\pgf@grabgray}%
+ {%
+ \pgfutil@ifnextchar c{\pgf@grabcolor}%
+ {\PackageError{pgfshade}{Illformed shading
+ specification}{}\pgf@converttorgb}%
+ }%
+ }%
+ }%
+ }%
+}
+\def\pgf@grabsemicolor;{%
+ \edef\pgf@rgbconv{\pgf@rgbconv; }\pgf@converttorgb}
+\def\pgf@grabrgb rgb(#1)=(#2,#3,#4){%
+ \edef\pgf@rgbconv{\pgf@rgbconv rgb(#1)=(#2,#3,#4)}\pgf@converttorgb}
+\def\pgf@grabgray gray(#1)=(#2){%
+ \edef\pgf@rgbconv{\pgf@rgbconv rgb(#1)=(#2,#2,#2)}\pgf@converttorgb}
+\def\pgf@grabcolor color(#1)=(#2){%
+ \pgfutil@colorlet{pgf@tempcol}{#2}%
+ \pgfutil@extractcolorspec{pgf@tempcol}{\pgf@tempcolor}%
+ \expandafter\pgfutil@convertcolorspec\pgf@tempcolor{rgb}{\pgf@rgbcolor}%
+ \expandafter\pgf@convgetrgb@\expandafter{\pgf@rgbcolor}{#1}%
+}
+\def\pgf@convgetrgb@#1#2{%
+ \edef\pgf@rgbconv{\pgf@rgbconv rgb(#2)=(#1)}\pgf@converttorgb}
+
+
+
+
+% Declares a horizontal shading for later use. The shading is a
+% horizontal bar that changes its color.
+%
+% #1 = optional dependencies
+% #2 = name of the shading for later use
+% #3 = height of the shading
+% #4 = color specification in the following format: A list of colors
+% that the bar should have at certain points. If the bar should
+% be red at 1cm, this is specified as
+% "rgb(1cm)=(1,0,0)". Multiple specifications are separated by a
+% semicolon and a space. At least two specifications must be
+% given. The specified positions must be given in increasing
+% order.
+%
+% Description:
+%
+% The optional dependecies have the following effect: If present, it
+% should consist of a list of colors, separated by commas. Each time
+% the shading is used, these colors will be reevaluated. It will be
+% checked whether the colors still have their "original meaning". If
+% the colors have changed, a new shading will be created internally to
+% reflect the changed color's values.
+%
+% Example:
+%
+% \pgfdeclarehorizontalshading{redtogreentoblue}{1cm}{%
+% rgb(0cm)=(1,0,0); % red
+% rgb(1cm)=(0,1,0); % green
+% rgb(2cm)=(0,0,1)}
+%
+% \begin{document}
+% The following bar is 2cm long: \pgfuseshading{redtogreentoblue}.
+% \end{document}
+
+\def\pgfdeclarehorizontalshading{\pgfutil@ifnextchar[\pgf@declarehorizontalshading{\pgf@declarehorizontalshading[]}}%
+\def\pgf@declarehorizontalshading[#1]#2#3#4{%
+ \expandafter\def\csname pgf@deps@pgfshading#2!\endcsname{#1}%
+ \expandafter\ifx\csname pgf@deps@pgfshading#2!\endcsname\pgfutil@empty%
+ \pgfsys@horishading{#2}{#3}{#4}%
+ \else%
+ \expandafter\def\csname pgf@func@pgfshading#2!\endcsname{\pgfsys@horishading}%
+ \expandafter\def\csname pgf@args@pgfshading#2!\endcsname{{#3}{#4}}%
+ \expandafter\let\csname @pgfshading#2!\endcsname=\pgfutil@empty%
+ \fi}
+
+
+% Declares a vertical shading for later use.
+%
+% #1 = optinal dependecies
+% #2 = name of the shading for later use
+% #3 = height of the shading
+% #4 = color specification
+%
+% Example:
+%
+% \pgfdeclareverticalshading{redtogreentoblue}{1cm}{%
+% rgb(0cm)=(1,0,0); % red
+% rgb(1cm)=(0,1,0); % green
+% rgb(2cm)=(0,0,1)}
+%
+% \begin{document}
+% The following bar is 2cm high: \pgfuseshading{redtogreentoblue}.
+% \end{document}
+
+\def\pgfdeclareverticalshading{\pgfutil@ifnextchar[\pgf@declareverticalshading{\pgf@declareverticalshading[]}}%
+\def\pgf@declareverticalshading[#1]#2#3#4{%
+ \expandafter\def\csname pgf@deps@pgfshading#2!\endcsname{#1}%
+ \expandafter\ifx\csname pgf@deps@pgfshading#2!\endcsname\pgfutil@empty%
+ \pgfsys@vertshading{#2}{#3}{#4}%
+ \else%
+ \expandafter\def\csname pgf@func@pgfshading#2!\endcsname{\pgfsys@vertshading}%
+ \expandafter\def\csname pgf@args@pgfshading#2!\endcsname{{#3}{#4}}%
+ \expandafter\let\csname @pgfshading#2!\endcsname=\pgfutil@empty%
+ \fi}
+
+
+% Declares a radial shading for later use.
+%
+% #1 = optional dependencies
+% #2 = name of the shading for later use
+% #3 = center of inner circle
+% #4 = color specification
+%
+% Description:
+%
+% A radial shading creates a smooth color transition between two
+% circles. The center of the inner circle is at the give position. Its
+% radius is the start of the color specification. The
+% center of the outer circle is at the center of the whole shading,
+% whose radius is the end of the color specification. For example,
+% suppose the color specification is "rgb(1cm)=(1,1,1); rgb(2cm)=(0,0,0)".
+% Then the shading would be 4cm times 4cm large. The inner circle would
+% have diameter 1cm and the outer circle would have diameter 2cm. The
+% outer circle would be centered in the middle of the shading, whereas
+% the outer circle would be centered at the given position.
+%
+% Example:
+%
+% \pgfdeclareradialshading{redtogreentoblue}{\pgfpoint{2cm}{2cm}}{%
+% rgb(10pt)=(1,0,0); % red
+% rgb(2cm)=(0,1,0); % green
+% rgb(3cm)=(0,0,1)}
+%
+% \begin{document}
+% The following ball has diameter 3cm: \pgfuseshading{redtogreentoblue}.
+% \end{document}
+
+\def\pgfdeclareradialshading{\pgfutil@ifnextchar[\pgf@declareradialshading{\pgf@declareradialshading[]}}%
+\def\pgf@declareradialshading[#1]#2#3#4{%
+ \expandafter\def\csname pgf@deps@pgfshading#2!\endcsname{#1}%
+ \expandafter\ifx\csname pgf@deps@pgfshading#2!\endcsname\pgfutil@empty%
+ \pgfsys@radialshading{#2}{#3}{#4}%
+ \else%
+ \expandafter\def\csname pgf@func@pgfshading#2!\endcsname{\pgfsys@radialshading}%
+ \expandafter\def\csname pgf@args@pgfshading#2!\endcsname{{#3}{#4}}%
+ \expandafter\let\csname @pgfshading#2!\endcsname=\pgfutil@empty%
+ \fi}
+
+
+
+
+% Declares a functional shading for later use.
+%
+% #1 = optional dependecies
+% #2 = name of the shading for later use
+% #3 = lower left corner of the shading as a pgfpoint.
+% #4 = upper right corner of the shading as a pgfpoint.
+% #5 = Preparation code
+% #6 = a PDF type 4 function (restricted Postscript function), see the
+% PDF-specification 1.7, section 3.9.4
+%
+% Description:
+%
+% This command creates a so-called functional shading. For such a
+% shading the color of each point is calculated by calling a function
+% for each point that gets the coordinates as input and yields the
+% color as an output. Note that the function is evaluated by the
+% *renderer*, not by PGF or TeX or someone else at compile-time. This
+% means that the evaluation of this function has to be done *extremely
+% quickly* and the funciton should be *very simple*. For this reason,
+% only a very restricted set of operations are possible in the
+% function (see 3.9.4 of the PDF-spec 1.7). Also functions should be
+% kept small. Any errors in the function will only be noticed by the
+% renderer.
+%
+% The function gets the coordinates of a point as input (as bp). This
+% input consists of the top two elements of an otherwise empty
+% (virtual, PostScript) stack. The function should then replace these
+% two values by three values, representing the red, green, and blue
+% color of the point. The numbers should be real values, not integers
+% since Apple's PDF renderer is broken in this regard (use cvr at the
+% end if necessary).
+%
+% Conceptually, the function will be evaluated once for each point of
+% the rectangle (#3) to (#4). A renderer may choose to evaluate the
+% function at less points, but, in principle, the function will be
+% evaluated for each pixel independently.
+%
+% Because of the rather difficult PostScript syntax, use this macro
+% only *if you know what you are doing* (or if you are advanterous, of
+% course).
+%
+% As for other shadings, the optional depencies argument is used to
+% determine whether a shading needs to be recalculated when a color
+% has changed.
+%
+% The code #5 is executed each time a shading is
+% (re)calculated. Typically, it will contain code to extract
+% coordinates from colors (see below).
+%
+% Inside the PostScript function #6 you cannot use colors
+% directly. Rather, you must push the color components on the
+% stack. For this, it is useful to call \pgfshadergb in the startup
+% code #4. The macro takes a color name as input and stores the color's
+% red/green/blue components real numbers between 0.0 and 1.0 separated
+% by spaces (which is exactly what you need if you want to push it on
+% a stack) in a macro.
+%
+% Example:
+%
+%\pgfdeclarefunctionalshading{twospots}{\pgfpointorigin}{\pgfpoint{200bp}{200bp}}{}{
+% 2 copy
+% 90 sub dup mul exch
+% 80 sub dup mul add sqrt
+% dup mul neg 1.0005 exch exp 1.0 exch sub
+% 3 1 roll
+% 120 sub dup mul exch
+% 100 sub dup mul add sqrt
+% dup mul neg 1.002 exch exp 1.0 exch sub
+% 1.0
+%}
+%
+% \pgfdeclarefunctionalshading[mycol]{sweep}{\pgfpointorigin}{\pgfpoint{100bp}{100bp}}
+% {\pgfshadecolortorgb{mycol}{\myrgb}}{
+% add 150 div % not very useful...
+% dup
+% \myrgb % push mycol
+% 5 4 roll % multiply all components by calculated value
+% mul
+% 3 1 roll
+% 3 index
+% mul
+% 3 1 roll
+% 4 3 roll
+% mul
+% 3 1 roll
+% }
+%
+% \begin{document}
+% Have a look at this: \pgfuseshading{twospots}.
+% Here is \colorlet{mycol}{green!50}\pgfuseshading{sweep} in green
+% and in \colorlet{mycol}{red!50!blue}\pgfuseshading{sweep} in red/blue.
+% \end{document}
+
+\def\pgfdeclarefunctionalshading{\pgfutil@ifnextchar[\pgf@declarefunctionalshading{\pgf@declarefunctionalshading[]}}%
+\def\pgf@declarefunctionalshading[#1]#2#3#4#5#6{%
+ \expandafter\def\csname pgf@deps@pgfshading#2!\endcsname{#1}%
+ \expandafter\ifx\csname pgf@deps@pgfshading#2!\endcsname\pgfutil@empty%
+ \pgfshade@functionaldo{#2}{#3}{#4}{#5}{#6}%
+ \else%
+ \expandafter\def\csname pgf@func@pgfshading#2!\endcsname{\pgfshade@functionaldo}%
+ \expandafter\def\csname pgf@args@pgfshading#2!\endcsname{{#3}{#4}{#5}{#6}}%
+ \expandafter\let\csname @pgfshading#2!\endcsname=\pgfutil@empty%
+ \fi}
+\def\pgfshade@functionaldo#1#2#3#4#5{%
+ {%
+ #4%
+ \pgfsys@functionalshading{#1}{#2}{#3}{#5}%
+ }%
+}
+
+\def\pgfshadecolortorgb#1#2{%
+ \pgfutil@colorlet{pgf@tempcol}{#1}%
+ \pgfutil@extractcolorspec{pgf@tempcol}{\pgf@tempcolor}%
+ \expandafter\pgfutil@convertcolorspec\pgf@tempcolor{rgb}{\pgf@rgbcolor}%
+ \expandafter\pgfshading@rgb\pgf@rgbcolor\relax%
+ \edef#2{\pgf@sys@tonumber{\pgf@xa}\space\pgf@sys@tonumber{\pgf@xb}\space\pgf@sys@tonumber{\pgf@xc}\space}%
+}
+\def\pgfshading@rgb#1,#2,#3\relax{%
+ \pgf@xa=#1pt%
+ \pgf@xb=#2pt%
+ \pgf@xc=#3pt%
+}
+
+
+
+
+% Inserts a box into the text that contains a previously defined
+% shading.
+%
+% #1 = Name of a shading
+%
+% Example:
+%
+% \pgfuseshading{redtogreentoblue}
+
+\def\pgfuseshading#1{%
+ \edef\pgf@shadingname{@pgfshading#1}%
+ \pgf@tryextensions{\pgf@shadingname}{\pgfalternateextension}%
+ \expandafter\pgfutil@ifundefined\expandafter{\pgf@shadingname}%
+ {\PackageError{pgfshade}{Undefined shading "#1"}{}}%
+ {%
+ {%
+ \pgfutil@globalcolorsfalse%
+ \def\pgf@shade@adds{}%
+ \pgfutil@ifundefined{pgf@deps\pgf@shadingname}%
+ {}%
+ {%
+ \edef\@list{\csname pgf@deps\pgf@shadingname\endcsname}%
+ \pgfutil@for\@temp:=\@list\do{%
+ {%
+ \pgfutil@ifundefined{applycolormixins}{}{\applycolormixins{\@temp}}%
+ \pgfutil@extractcolorspec{\@temp}{\pgf@tempcolor}%
+ \expandafter\pgfutil@convertcolorspec\pgf@tempcolor{rgb}{\pgf@rgbcolor}%
+ \xdef\pgf@shade@adds{\pgf@shade@adds,\pgf@rgbcolor}%
+ }%
+ }%
+ }%
+ \expandafter\pgf@strip@shadename\pgf@shadingname!!%
+ \pgfutil@ifundefined{@pgfshading\pgf@basename\pgf@shade@adds!}%
+ {%
+ {%
+ \expandafter\def\expandafter\@temp\expandafter{\csname pgf@func\pgf@shadingname\endcsname}%
+ \edef\@args{{\pgf@basename\pgf@shade@adds}}%
+ \expandafter\expandafter\expandafter\def%
+ \expandafter\expandafter\expandafter\@@args%
+ \expandafter\expandafter\expandafter{\csname pgf@args\pgf@shadingname\endcsname}%
+ \expandafter\expandafter\expandafter\@temp\expandafter\@args\@@args%
+ %
+ }%
+ }%
+ {}%
+ \pgf@invokeshading{\csname @pgfshading\pgf@basename\pgf@shade@adds!\endcsname}%
+ }%
+ }%
+}
+
+\def\pgf@strip@shadename @pgfshading#1!!!{\def\pgf@basename{#1}}
+
+\def\pgf@invokeshading#1{%
+ \ifpgfpicture%
+ \pgfsys@shadinginsidepgfpicture{#1}%
+ \else%
+ \pgfsys@shadingoutsidepgfpicture{#1}%
+ \fi%
+}
+
+
+% Create an alias name for a shading
+%
+% #1 = name of the alias
+% #2 = name of the original
+%
+% Example:
+%
+% \pgfaliasshading{shading!25}{shadingshaded}
+
+\def\pgfaliasshading#1#2{%
+ \expandafter\let\expandafter\pgf@temp\expandafter=\csname @pgfshading#2!\endcsname%
+ \expandafter\let\csname @pgfshading#1!\endcsname=\pgf@temp%
+ \expandafter\let\expandafter\pgf@temp\expandafter=\csname pgf@deps@pgfshading#2!\endcsname%
+ \expandafter\let\csname pgf@deps@pgfshading#1!\endcsname=\pgf@temp%
+ \expandafter\let\expandafter\pgf@temp\expandafter=\csname pgf@func@pgfshading#2!\endcsname%
+ \expandafter\let\csname pgf@func@pgfshading#1!\endcsname=\pgf@temp%
+ \expandafter\let\expandafter\pgf@temp\expandafter=\csname pgf@args@pgfshading#2!\endcsname%
+ \expandafter\let\csname pgf@args@pgfshading#1!\endcsname=\pgf@temp%
+}
+
+
+
+
+% Shades the current path, but does not discard it.
+%
+% #1 - a shading (see below)
+% #2 - an angle
+%
+% Description:
+%
+% \pgfshadepath ``tries'' to fill the
+% current path with a shading. The shading's original size should
+% completely cover the area between (0,0) and (100bp,100bp). The
+% shading will be rotated by #2 and then rescaled so that it
+% completely covers the path. Then the path will be used (locally) for
+% clipping and the shading is drawn.
+%
+% In addition to the rotation, any transformation set by the
+%\pgfsetadditionalshadetransform will also be applied.
+%
+% After all this, the path can still be used for the normal
+% stroking/clipping operations.
+%
+% The shading is rotated around its middle. If no rotation occurs, the
+% lower left corner of the path will lie on (25bp, 25bp), the upper
+% right corner on (75bp, 75bp).
+%
+% Example:
+%
+% \pgfdeclareverticalshading{myshading}{100bp}{color(0pt)=(red); color(100bp)=(green)}
+%
+% \pgfpathmoveto{\pgforigin}
+% \pgfpathlineto{\pgfxy(1,0)}
+% \pgfpathlineto{\pgfxy(1,1)}
+% \pgfshadepath{myshading}{0}
+% \pgfusepath{stroke}
+
+\def\pgfshadepath#1#2{%
+ \ifdim\pgf@pathminx=16000pt%
+ \PackageWarning{pgfshade}{No path specified that can be filled}%
+ \else%
+ \begingroup%
+ \pgfsys@beginscope%
+ % Calculate center:
+ \pgf@xb=.5\pgf@pathmaxx%
+ \advance\pgf@xb by.5\pgf@pathminx%
+ \pgf@yb=.5\pgf@pathmaxy%
+ \advance\pgf@yb by.5\pgf@pathminy%
+ % Calculate scaling:
+ \pgf@xc=\pgf@pathmaxx%
+ \advance\pgf@xc by-\pgf@pathminx%
+ \pgf@yc=\pgf@pathmaxy%
+ \advance\pgf@yc by-\pgf@pathminy%
+ \pgf@xc=.02\pgf@xc%
+ \pgf@yc=.02\pgf@yc%
+ \pgfsyssoftpath@invokecurrentpath%
+ \pgfsys@clipnext%
+ \pgfsys@discardpath%
+ % Compute new transformation matrix:
+ \pgfsys@transformcm{1}{0}{0}{1}{\pgf@xb}{\pgf@yb}%
+ \pgfsys@transformcm%
+ {\pgf@sys@tonumber{\pgf@xc}}{0}%
+ {0}{\pgf@sys@tonumber{\pgf@yc}}{0pt}{0pt}%
+ \pgfmathparse{#2}%
+ \let\pgfshade@angle=\pgfmathresult%
+ \pgfmathsin@{\pgfshade@angle}%
+ \let\pgfshade@sin=\pgfmathresult%
+ \pgfmathcos@{\pgfshade@angle}%
+ \let\pgfshade@cos=\pgfmathresult%
+ \pgf@x=\pgfshade@sin pt%
+ \pgf@xa=-\pgf@x%
+ \pgfsys@transformcm{\pgfshade@cos}{\pgfshade@sin}{\pgf@sys@tonumber{\pgf@xa}}{\pgfshade@cos}{0pt}{0pt}%
+ \ifx\pgf@shade@extra@transform\pgfutil@empty%
+ \else%
+ \pgflowlevel{\pgf@shade@extra@transform}%
+ \fi%
+ \pgfuseshading{#1}%
+ \pgfsys@endscope%
+ \endgroup%
+ \fi%
+}
+
+
+% Additionally transform shade paths
+%
+% #1 = Transformation code that is used in addition to the normal
+% shading transformation.
+%
+% Example:
+%
+% \pgfsetadditionalshadetransform{\pgftransformrotate{30}}
+
+\def\pgfsetadditionalshadetransform#1{\def\pgf@shade@extra@transform{#1}}
+\let\pgf@shade@extra@transform=\pgfutil@empty
+
+
+
+
+
+\endinput