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+%% $Id$
+%%
+%% Xy-pic ``Necula extensions'' option.
+%% Copyright (c) 1998 George C. Necula <necula@cs.cmu.edu>
+%%
+%% This file is part of the Xy-pic package for graphs and diagrams in TeX.
+%% See the companion README and INSTALL files for further information.
+%% Copyright (c) 1991-1998 Kristoffer H. Rose <krisrose@ens-lyon.fr>
+%%
+%% The Xy-pic package 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 2 of the License, or (at your
+%% option) any later version.
+%%
+%% The Xy-pic package 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 package; if not, write to the Free Software Foundation, Inc.,
+%% 675 Mass Ave, Cambridge, MA 02139, USA.
+%%
+\ifx\xyloaded\undefined \input xy \fi
+
+\xyprovide{necula}{Necula's extensions}{\stripRCS$Revision: 0.0 $}%
+ {George C. Necula}{necula@cs.cmu.edu}%
+ {School of Computer Science,
+ Carnegie Mellon University,
+ 5000 Forbes Avenue,
+ Pittsburgh, PA 15213-3891, USA}
+
+\DOCMODE2%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+\paragraph*{Header:}\leavevmode
+\DOCHEADER
+\DOCMODE3%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+ This option contains two extensions of the \Xy-pic kernel: A way to
+ expand \TeX\ macros in object <modifier>s, and a way to specify
+ arbitrary polygons as the <shape> of an object.
+
+\DOCMODE3%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+\subsection{Expansion}
+
+ The special syntax ??c![e|]<macros>|||| is introduced in
+ an object ??w![<modifier>]s and ??w![<coord>]inates. It
+ expands the given \TeX\ <macros> (with |\edef|) before
+ reinterpretation as a <modifier> of <coord>, respectively.
+
+\DOCMODE(
+\def\expandbeforenext@#1{%
+ \DN@ e|##1|{\edef\tmp@{##1}\expandafter\xyFN@\expandafter#1\tmp@}%
+}
+
+\xylet@\xy@oldOBJECT@=\OBJECT@
+\xydef@\xy@newOBJECT@{%
+ \ifx \space@\next \expandafter\DN@\space{\xyFN@\xy@newOBJECT@}%gobble spaces
+ \else\ifx e\next
+ \expandbeforenext@\OBJECT@
+ \else
+ \DN@{\xy@oldOBJECT@}\fi\fi
+ \next@}%
+\let\OBJECT@=\xy@newOBJECT@
+
+\xylet@\xy@oldCOORD@=\COORD@
+\xydef@\xy@newCOORD@{%
+ \ifx \space@\next \expandafter\DN@\space{\xyFN@\xy@newCOORD@}%gobble spaces
+ \else\ifx e\next
+ \expandbeforenext@\COORD@
+ \else
+ \DN@{\xy@oldCOORD@}\fi\fi
+ \next@}%
+\let\COORD@=\xy@newCOORD@
+\DOCMODE)
+
+ This code may become part of the \Xy-pic kernel at a certain point.
+
+\DOCMODE3%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+\subsection{Polygon shapes}
+
+ A polygon <shape> is specified as
+%
+\begin{defs1}
+%
+ ??c![[P:]<pos>|,|\dots|,|<pos>|]|
+%
+\end{defs1}
+\noindent\unskip
+%
+ where |[P:|$p_1$|,|\dots|,|$p_n$|]| denotes the shape obtained by
+ tracking the edge with each $p_i$ a position relative to the object
+ reference point. <vector>s and <corner>s can be used
+ directly; otherwise use |-p| to get the relative position.
+
+ \NOTE: Do not use |{}| or |[]| in the <pos>itions.
+
+ \BUG: The algorithm assumes that the reference point is always inside
+ the polygon.
+
+ It is possible to frame polygons is also possible.
+
+\DOCMODE(
+% Define the polygon as a stylechar so that it is deferred
+\xydefcsname@{*stylechar@P@}#1{\Pshape@#1@}
+\xynew@{count}\c@poly@count \c@poly@count=\z@ % Polygon identifiers
+
+\xydef@\Pshape@:#1@{% Strip the mandatory :
+ \addtotoks@{%
+% \xy@showthe c{Before parse}\xy@showthe p{Before parse}%
+% \xy@showdim{Before parse}%
+ \def\poly@list{@}%
+ \poly@parse #1,\relax,%Sets the poly@list
+ \def\poly@cache{}%
+ \edef\poly@id{\the\c@poly@count}%
+ \global\advance\c@poly@count\@ne
+ \poly@setEdge
+ % Save the old values of Lc for shifting
+ \edef\poly@saveLcshape{\the\L@c}%
+ \polygonEdge@Outer% Set U,R,D,L
+ \poly@setEdge
+ % Now shift the object to keep it centered
+ \dimen@=\poly@saveLcshape\advance\dimen@-\L@c
+ \advance\R@p -\dimen@
+% \xy@showthe c{After parse}%
+}}
+
+% Set the edge
+% A polygonal edge is represented as \polygonEdge x1,y1;x2,y2;...;xn,yn@id@
+% where xi,yi define the vertices of the polygonal edge as displacement from
+% the object reference point (xn=x1,yn=y1), and id is a numerical id used for
+% caching the result of the last intersection operation. The cached values for
+% polygon id are stored in the global macro poly@cache<id>.
+\xydef@\poly@setEdge{\expandafter\poly@setEdge@\poly@list\poly@id}
+\xydef@\poly@setEdge@#1@#2{\Edge@c={\polygonEdge#1@#2@}%
+ \expandafter\xdef\csname poly@cache#2%
+ \endcsname{\poly@cache}}
+
+% Define the polygon framing operations
+\xydefcsname@{frm[P]{-}}{\expandafter\draw@polyframe\the\Edge@c{-}}
+\xydefcsname@{frm[P]{.}}{\expandafter\draw@polyframe\the\Edge@c{.}}
+\xydefcsname@{frm[P]{=}}{\expandafter\draw@polyframe\the\Edge@c{=}}
+
+
+\xydef@\draw@polyframe\polygonEdge#1@#2@#3{%
+ \def\poly@dir{#3}%
+ \def\poly@list{#1@}%
+ \def\poly@id{#2}%
+ \edef\poly@cache{\csname poly@cache\poly@id\endcsname}%
+ \draw@polygon}
+
+% A polygon is maintained as a list of relative positions, as follows:
+% poly@list = Xdimen_0,Ydimen_0;...;Xdimen_n,Ydimen_n @
+% The list is closed, i.e., the first and last element coincide
+% Each polygon has an id storred in \poly@id
+% Each polygon caches the result of the last intersection operation
+% as d@x,d@y,x1,y1,x2,y2 where the first two values define the slope
+% and the two sets of points are the two intersection points
+% These values are storred in \poly@cache<id>.
+%
+%
+% Helper function for dealing with polygon lists
+
+% Map over a polygon list. Make sure you define
+% \let\poly@map@next=\poly@map before. Then, you can define
+% \let\poly@map@next=\poly@map@stop if you want to stop the traversal
+
+\xydef@\poly@empty{}
+\xydef@\poly@map#1#2,#3;#4@{%
+ #1{#2}{#3}%
+ \def\tmp@{#4}%
+ \ifx \poly@empty\tmp@ \else
+ \poly@map@next#1#4@%
+ \fi
+}
+
+\xydef@\poly@map@stop#1@{}
+
+\xydef@\poly@mapExpand#1#2{%
+ \edef\tmp@{\noexpand\poly@map\noexpand #1#2}%
+ \tmp@}
+
+% Parse a polygon definition
+
+\xydef@\poly@parse #1,{%
+ \ifx #1\relax %Done. Copy the head of the list at its end
+ \poly@close
+ \let\next@=\relax
+ \else
+ % Save everything
+ \save@
+ % Process the position using POS
+ \POS #1%
+ % Now add the new c to the list
+ \edef\tmp@{{\the\X@c}{\the\Y@c}}%
+ \expandafter\poly@append\tmp@
+ \restore
+ \let\next@=\poly@parse % continue parsing
+ \fi
+ \next@
+}
+ % Append to the list of polygon points
+\xydef@\poly@append#1#2{\expandafter\poly@append@\poly@list{#1,#2;}}
+\xydef@\poly@append@#1@#2{\global\def\poly@list{#1#2@}}
+
+ % Close the polygon
+\xydef@\poly@close{\expandafter\poly@close@\poly@list}
+\xydef@\poly@close@#1,#2;#3@{\poly@append{#1}{#2}}
+
+% Draw a polygon at the current location
+
+\xydef@\draw@polygon{% First separate the head
+% \W@{Drawing polygon \poly@list}\xy@showthe c{ Centered at}%
+ \save@
+ % Set the origin to point at the reference point
+ \X@origin=\X@c \Y@origin=\Y@c
+ \poly@setp % Set p at the beginning of the polygon and set poly@rest
+ % Zero the edges
+ \U@c=\z@\R@c=\z@\D@c=\z@\L@c=\z@\U@p=\z@\R@p=\z@\D@p=\z@\L@p=\z@
+ \Edge@c={\zeroEdge}\Edge@p={\zeroEdge}%
+ \let\poly@map@next=\poly@map
+ \poly@mapExpand\poly@drawseg\poly@rest
+ \restore
+}
+
+ % Set p to the first element. Requires the origin to be
+ % at the reference point
+\xydef@\poly@setp{\expandafter\poly@setp@\poly@list}
+\xydef@\poly@setp@#1,#2;#3@{%
+ \X@p=#1\advance\X@p\X@origin \Y@p=#2\advance\Y@p\Y@origin%
+ \global\def\poly@rest{#3@}}
+
+\xydef@\poly@drawseg#1#2{%
+ \dimen@=#1\X@c=\the\dimen@\advance\X@c \X@origin
+ \dimen@=#2\Y@c=\the\dimen@\advance\Y@c \Y@origin
+% \W@{Next segment is at offset #1,#2 and absolute \the\X@c,\the\Y@c}%
+ \expandafter\connect@\expandafter\dir\poly@dir%
+ \X@p=\X@c\Y@p=\Y@c}
+
+% Polygonal edge
+% Requires c to be the reference point
+\xydef@\polygonEdge#1@#2@#3{%
+ \def\poly@list{#1@}%
+ \def\poly@id{#2}%
+ \edef\poly@cache{\csname poly@cache\poly@id\endcsname}%
+ \ifcase#3\relax
+ \DN@{\polygonEdge@Inters
+% \ifpoly@badinters
+% \xyerror@{Could not find intersection for polygon}\fi
+ }%0
+ \or \DN@{\polygonEdge@Under}%1
+ \or \DN@{\polygonEdge@Dist}%2
+ \or \DN@{\rectangleProp@}%3 I do not understand Prop!
+ \or \DN@{\polygonEdge@Inner}%4
+ \or \DN@{\polygonEdge@Outer}%5
+ \else \DN@{}\fi
+ \next@}
+
+
+\newif\ifpoly@badinters
+
+\xydef@\polygonEdge@Inters{%
+% \W@{Edge intersection with (\the\X@c, \the\Y@c) -> (\the\X@p,\the\Y@p)}%
+% \W@{ for polygon: \poly@id}%
+% \W@{ with list: \poly@list}%
+% \W@{ with cache: \poly@cache}%
+ % Check the cache first
+ \ifx\poly@cache\poly@empty
+ \poly@intersdoit
+ \else
+ \expandafter\poly@intersprobecache\poly@cache @%
+ \fi
+% \xy@showthe c{Inters res}%
+}
+
+%
+% Redefine poly@cachehit to poly@cachehitdisable to diable polygon caching
+\xydef@\poly@cachehit#1#2{%
+% \W@{ intersection point found in cache}%
+ \X@c=#1\Y@c=#2}
+
+\xydef@\poly@cachehitdisable#1#2{\poly@intersdoit}
+%\let\poly@cachehit=\poly@cachehitdiasable% Uncomment this line to disable $
+
+
+% Probes the cache
+%
+\xydef@\poly@intersprobecache#1,#2,#3,#4,#5@{%
+ \dimen@=#1\advance\dimen@-\d@X
+ \ifdim\zz@\dimen@
+ \dimen@=#2\advance\dimen@-\d@Y
+ \ifdim\zz@\dimen@
+ \poly@cachehit{#3}{#4}
+ \else
+ \poly@intersdoit
+ \fi
+ \else
+ \poly@intersdoit
+ \fi
+}
+
+
+% Computes the intersection between the line cp and the edge.
+% Both intersection points are stored in the cache, the one in the
+% direction towards p first.
+\xydef@\poly@intersdoit{%
+% \W@{ intersection not in cache. Computing it}%
+ % Save A@ and B@ because we cannot change them
+ \edef\polyoldA@{\the\A@}\edef\polyoldB@{\the\B@}%
+ % Initialize the intersection points
+ \def\poly@intersneg{}\def\poly@interspos{}%
+ \save@
+ \poly@setorigin % Set origin at the beginning of the polygon and
+ % set poly@rest
+ \def\zeroDivide@{\poly@badinterstrue}% Handle the division by zero except.
+ \let\poly@map@next=\poly@map
+ \poly@mapExpand\poly@interseg\poly@rest
+ \ifx\poly@intersneg\poly@empty
+ \poly@badinterstrue
+ \else
+ \ifx\poly@interspos\poly@empty
+ \poly@badinterstrue
+ \else
+ \poly@badintersfalse
+ \fi
+ \fi
+ \restore
+ \A@=\polyoldA@\B@=\polyoldB@ % Restore A@ and B@
+ \ifpoly@badinters \else
+ \edef\tmp@{\poly@interspos,\poly@intersneg @}%
+ \expandafter\poly@intersfinish\tmp@
+ \fi
+}
+
+\xydef@\poly@intersfinish#1,#2,#3@{%
+ \X@c=#1\Y@c=#2\relax
+ \xdef\poly@cache{\the\d@X,\the\d@Y,#1,#2,#3}%
+ \poly@setEdge
+}
+
+
+ % Set origin to the first point. Define poly@rest
+ % Requires c to be set to the reference point
+\xydef@\poly@setorigin{\expandafter\poly@setorigin@\poly@list}
+\xydef@\poly@setorigin@#1,#2;#3@{%
+ \X@origin=#1\advance\X@origin\X@c \Y@origin=#2\advance\Y@origin\Y@c%
+ \global\def\poly@rest{#3@}}
+
+
+
+
+%
+% Compute one intersection with a given edge
+% c is set to the reference point, p is set to the end of the ray
+% origin is set to the start of the segment
+\xydef@\poly@interseg#1#2{%
+ % Default is no intersection
+% \W@{ Intersection with edge (\the\X@origin,\the\Y@origin) -> (#1,#2)}%
+ % Compute the absolute values
+ \dimen@=#1\advance\dimen@\X@c \edef\poly@saveXcinters{\the\dimen@}%
+ \dimen@=#2\advance\dimen@\Y@c \edef\poly@saveYcinters{\the\dimen@}%
+ \save@
+ \poly@badintersfalse
+ % Set R@c and U@c to the distance to end of segment
+ \R@c=\poly@saveXcinters \advance\R@c -\X@origin
+ \U@c=\poly@saveYcinters \advance\U@c -\Y@origin
+ % Now call intersect to set X@c and Y@c to the intersection point
+ \intersect@
+ \A@=\X@c \B@=\Y@c % Save result
+ \restore
+ \ifpoly@badinters
+% \W@{ \space failed after intersect}%
+ \else
+% \W@{ \space after intersect@ (\the\A@,\the\B@)}%
+ % Verify that it is on the segment from origin to (#1, #2)
+
+\poly@isonseg\X@origin\Y@origin\A@\B@\poly@saveXcinters\poly@saveYcinters
+ \ifpoly@badinters
+% \W@{ \space failed after seg check}%
+ \else
+ % Verify that (A,B) is on the ray from c to p
+ \poly@isonray\X@c\Y@c\A@\B@\X@p\Y@p
+ \ifpoly@badinters
+ % It is on the negative ray
+% \W@{ \space a negative intersection}%
+ \edef\poly@intersneg{\the\A@,\the\B@}%
+ \else
+% \W@{ \space a positive intersection}%
+ \edef\poly@interspos{\the\A@,\the\B@}%
+ \fi
+ \fi
+ \fi
+ % Set the origin to the start of the next segment
+ \X@origin=\poly@saveXcinters\Y@origin=\poly@saveYcinters
+}
+
+
+%
+% Computes the distance from reference point to the intersection
+%
+\xydef@\polygonEdge@Dist{\xyerror@{Dist is not yet implemented for polygons}}
+
+%
+% Checks that #1 <= #2 <= #3 or that #3 <= #2 <= #1
+% Sets ifpoly@badinters otherwise
+% ifpoly@closedrange decides whether the second inequality is also checked
+% All checks are done with a precision of 100*almostz@ =~ 5000sp = 0.08pt
+\newif\ifpoly@closedrange
+\xydef@\poly@isinrange#1#2#3{%
+ \ifpoly@badinters \else
+ \dimen@=#1\dimen@i=#2\dimen@ii=#3\relax
+% \W@{check if in \ifpoly@closedrange closed\else open\fi\space
+% range 1=\the\dimen@,2=\the\dimen@i,3=\the\dimen@ii}%
+ \advance\dimen@ii -\dimen@ \advance\dimen@i -\dimen@
+ \ifdim\dimen@ii<0pt\relax
+ \ifdim\dimen@i>100\almostz@
+ \poly@badinterstrue
+ \fi
+ \dimen@i=-\dimen@i \dimen@ii=-\dimen@ii
+ \else
+ \ifdim\dimen@i<-100\almostz@\relax
+ \poly@badinterstrue
+ \fi
+ \fi
+ \ifpoly@closedrange
+ \advance\dimen@ii 100\almostz@
+ \ifdim\dimen@i>\dimen@ii
+ \poly@badinterstrue
+ \fi
+ \fi
+% \ifpoly@badinters \W@{ failed}\else\W@{ succeeded}\fi
+ \fi}
+
+%
+% Checks that (#3,#4) is on a segment defined by (#1,#2)->(#5,#6)
+\xydef@\poly@isonseg#1#2#3#4#5#6{%
+ % Check X first
+ \poly@closedrangetrue
+ \poly@isinrange{#1}{#3}{#5}%
+ \poly@isinrange{#2}{#4}{#6}%
+
+}
+
+%
+% Checks that (#3,#4) is on a ray defined by (#1,#2)->(#5,#6)
+\xydef@\poly@isonray#1#2#3#4#5#6{%
+ % Check X first
+ \poly@closedrangefalse
+ \poly@isinrange{#1}{#3}{#5}%
+ \poly@isinrange{#2}{#4}{#6}%
+
+}
+%
+% Test whether (Xp,Yp) is inside the polygon (or on the edge)
+% Sets \ifInside@ accordingly
+\xydef@\polygonEdge@Under{%
+% \W@{}\W@{Edge Under with c=(\the\X@c,\the\Y@c) and p=(\the\X@p,\the\Y@p)}%
+% \W@{ for polygon: \poly@list}%
+ % Save A@ and B@
+ \edef\polysaveA@under{\the\A@}\edef\polysaveB@under{\the\B@}%
+ % Save X@c and Y@c
+ \edef\poly@saveXcUnder{\the\X@c}\edef\poly@saveYcUnder{\the\Y@c}%
+ % Compute the intersection
+ \polygonEdge@Inters
+ \ifpoly@badinters% p is very close to c
+ \Inside@true
+ \else
+ \A@=\X@c\B@=\Y@c
+ % Restore c
+ \X@c=\poly@saveXcUnder\Y@c=\poly@saveYcUnder
+ % Now verify that the intersection point is on the ray c->p
+ \poly@isonseg\X@c\Y@c\X@p\Y@p\A@\B@
+ \ifpoly@badinters \Inside@false \else \Inside@true\fi
+ \A@=\polysaveA@under\B@=\poly@saveB@under
+ \fi
+% \ifInside@\W@{->inside}\else\W@{->outside}\fi
+}
+
+%
+% Compute the inner rectangle
+%
+\xydef@\polygonEdge@Inner{%
+% \W@{}\W@{Edge Inner with (\the\X@c, \the\Y@c) -> (\the\X@p,\the\Y@p)}%
+% \W@{ for polygon: \poly@list}%
+% \W@{ with cache: \poly@cache}%
+ % Save everything except c
+ \enter@{\basefromthebase@ \pfromthep@ \DirectionfromtheDirection@}%
+ % Save c in Lc,Dc
+ \L@c=\X@c \D@c=\Y@c
+ % Compute the two intersection points
+ \polygonEdge@Inters
+ \ifpoly@badinters
+ \czeroEdge@
+ \else
+ % Save the result in Rc,Uc and in X@c,Y@c
+ \expandafter\poly@getinterspoints\poly@cache @%
+ % Now compute the inner rectangle centered
+ \ifdim\X@c>\R@c
+ \L@c=\R@c \R@c=\X@c
+ \else
+ \L@c=\X@c
+ \fi
+ \X@c=0.5\L@c \advance\X@c 0.5\R@c \advance\R@c -\X@c \L@c=\R@c
+ \ifdim\Y@c>\U@c
+ \D@c=\U@c \U@c=\Y@c
+ \else
+ \D@c=\Y@c
+ \fi
+ \Y@c=0.5\D@c \advance\Y@c 0.5\U@c \advance\U@c -\Y@c \D@c=\U@c
+ \Edge@c={\rectangleEdge}%
+ \fi
+ \leave@
+% \xy@showthe c{After inner}%
+}
+
+\xydef@\poly@getinterspoints#1,#2,#3,#4,#5,#6@{%
+ \R@c=#3\U@c=#4\X@c=#5\Y@c=#6}
+
+%
+% Compute the outer rectangle (set Uc,Dc,Lc,Rc and Edgec).
+% Does not change Xc,YC
+%
+\xydef@\polygonEdge@Outer{%
+% \W@{Computing outer for \poly@list}\xy@showthe c{Before outer}%
+ % Save everything except c
+ \enter@{\basefromthebase@ \pfromthep@ \DirectionfromtheDirection@}%
+ \czeroEdge@ % Zero out c
+ \let\poly@map@next=\poly@map
+ \poly@mapExpand\poly@findextent\poly@list
+ \Edge@c={\rectangleEdge}%
+ \leave@
+% \xy@showthe c{After outer}
+}
+
+\xydef@\poly@findextent#1#2{%
+% \xy@showthe c{Before find extent}%
+% \W@{ extx=#1, exty=#2}%
+ \dimen@=#1\dimen@=\the\dimen@% it fails if I remove the second assign
+ \ifdim\dimen@>\R@c \R@c=\dimen@ \fi
+ \ifdim -\dimen@>\L@c \L@c=-\dimen@ \fi
+ \dimen@=#2\dimen@=\the\dimen@% it fails if I remove the second assign
+ \ifdim\dimen@>\U@c \U@c=\dimen@ \fi
+ \ifdim -\dimen@>\D@c \D@c=-\dimen@ \fi
+% \xy@showthe c{ After extent}%
+}
+
+% Change to account for polynomial shapes, in addition to circular ones
+%
+\xydef@\Fshape@#1:{\def\whichframe@@{{#1}}\let\whichoptions@@=\empty
+ \DN@{{}}\ifx\whichframe@@\next@ \def\whichframe@@{{-}}\fi
+ \expandafter\xyFN@\expandafter\Fshape@whichframe\the\Edge@c}
+
+\xydef@\Fshape@whichframe{%
+ \ifx\next\circleEdge
+ \edef\whichframe@@{[o]\whichframe@@}%
+ \DN@##1{\xyFN@\Fshape@i}%
+ \else
+ \ifx\next\polygonEdge
+ \edef\whichframe@@{[P]\whichframe@@}%
+ \DN@\polygonEdge##1@##2@{\xyFN@\Fshape@i}%
+ \else
+ \DN@##1{\xyFN@\Fshape@i}%
+ \fi\fi
+ \next@
+}
+
+\xyendinput
+\DOCMODE)
+
+\DOCMODE3%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+ \BUG: This code should be merged with the `frame' and `poly'
+ options.
+
+ The example at the end of \S??g[:smart] illustrates the extensions.
+
+\DOCMODE2%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+\DOCMODE(
+% $Log$
+% Received from George.
+\DOCMODE)
+
+\DOCMODE3%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+% Tell Emacs that this is a LaTeX document and how it is formatted:
+% Local Variables:
+% mode:latex
+% fill-prefix:"\t"
+% fill-column:77
+% paragraph-separate:"^[ \t\f]*$\\|^[^\t]\\|\\\\\\\\\\|\\$\\$\\|[^\n\\\\][%&]"
+% paragraph-start:"^[ \t\f]*$\\|^[^\t]\\|\\\\\\\\\\|\\$\\$\\|[^\n\\\\][%&]"
+% End: