%% $Id: xytpic.doc,v 3.3 1996/12/18 09:50:38 ross Exp $
%%
%% Xy-pic ``tpic'' TPIC backend, for lines, curves and fills.
%% Copyright (c) 1995-1996	Ross Moore	<ross@mpce.mq.edu.au>
%%
%% 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) 1991-1996	Kristoffer H. Rose	<krisrose@brics.dk>
%%
%% 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{tpic}{TPIC backend}{\stripRCS$Revision: 3.3 $}%
 {Ross Moore}{ross@mpce.mq.edu.au}%
 {Mathematics Department, Macquarie University, NSW~2109, Australia}

\DOCMODE3%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

\ifx\undefined\TPIC \def\TPIC{{\smc tpic}}\fi
This option allows the \Xy-pic fonts to be replaced by \TPIC\ |\special|s,
when used with a dvi-driver capable of supporting them. Extra capabilities
include smoother lines, evenly spaced dotted/dashed curves, variable
line-widths, gray-scale fills of circles, ellipses and polygonal regions. 

\DOCMODE2%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\paragraph*{Header:}\leavevmode
\DOCHEADER
\DOCMODE3%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

Use of \TPIC\ |\special|s offers an alternative to the \Xy-pic fonts. However
they require a dvi-driver that is capable of recognizing and interpreting
them. One such viewer is |xdvik|, Karl Berry's modification to the |xdvi|
viewer on \unix\ systems running X-windows or a derivative.  |dvipsk|, Karl
Berry's modification to |dvips| also handles \TPIC\ |\special|s, so
|xdvik|/|dvipsk| is an good combination for quality screen-display and
\PS\ printing. 

Once loaded using |\xyoption{tpic}|, with an appropriate <driver> also
specified either already or subsequently, the following commands are
available to turn the \TPIC\ backend off/on.
%
\begin{defs}
|\NoTPICspecials| & turns off \TPIC\ specials.\kern-50pt\cr
|\UseTPICspecials| & reinstates \TPIC\ specials.\kern-30pt
\end{defs}

\DOCMODE(
\xynew@{if}\ifTPICspecials@
\xydef@\UseTPICspecials{\TPICspecials@true}
\xydef@\NoTPICspecials{\TPICspecials@false}
\DOCMODE)

\DOCMODE3%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

There is a limit to the number of points allowable in a path. For paths 
constructed by \Xy-pic, which includes spline curves, when the limit 
is reached the path is automatically flushed and a new path commenced.
The following command can be used to customise this limit---initially
set at $300$ for use with \xdvi---to suit alternative <driver>s.
%
\begin{defs}
|\maxTPICpoints{|<num>|}| & set maximum for paths
\end{defs}

\DOCMODE(
\xynew@{count}\xytpic@cnt
\xydef@\xytpic@max{300}
\xydef@\maxTPICpoints#1{\count@=#1 \relax
 \ifnum\count@>\tw@ \edef\xytpic@max{\the\count@}%
 \else\expandafter\xyTPICmaxwarning@\expandafter{\the\count@}\fi}
\xydef@\xyTPICmaxwarning@#1{max points must be at least 2, #1 invalid}
\DOCMODE)

\DOCMODE2%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

Each object involving \TPIC\ |\special|s must set the style, using
|\xytpic@set@| to store a macro as the expansion of |\xytpic@style@@|.
Currently this is global, since a \TPIC\ object must be completed once
it has been started --- perhaps this is not necessary.

Note that |\xytpic@set@| uses |\xdef|, but has a |\noexpand| in its 
expansion; this forces expansion of the argument, when there is one,
to the control sequence passed as the first token following |\xytpic@set@|.

\DOCMODE(
\xydef@\xytpic@style@@{\xytpic@fp}
\xydef@\xytpic@reset@{\gdef\xytpic@style@@{\xytpic@fp}%
 \global\xytpic@cnt=\z@ }
\xydef@\xytpic@set@#1{\xdef\xytpic@style@@{\noexpand#1}}
\DOCMODE)

Here are the actual |\specials| that get placed in the dvi-file.

\DOCMODE(
\xydef@\xytpic@pn#1{\xyTPIC@special{pn #1}}
\xydef@\xytpic@pa#1#2{\global\advance\xytpic@cnt\@ne\relax
 \ifnum\xytpic@cnt=\xytpic@max\relax \xyTPIC@special{pa #1 #2}%
  \kern-\X@c\raise-\Y@c\hbox{\xytpic@style@@}\kern\X@c
% \xytpic@ip
 \global\xytpic@cnt=\@ne \relax\fi \xyTPIC@special{pa #1 #2}}
\xydef@\xytpic@fp{\xyTPIC@special{fp}}
\xydef@\xytpic@ip{\xyTPIC@special{ip}}
\xydef@\xytpic@da#1{\xyTPIC@special{da #1}}
\xydef@\xytpic@dt#1{\xyTPIC@special{dt #1}}
\xydef@\xytpic@sp#1{\xyTPIC@special{sp #1}}
\xydef@\xytpic@ar#1#2#3#4#5#6{\xyTPIC@special{ar #1 #2 #3 #4 #5 #6}}
\xydef@\xytpic@ia#1#2#3#4#5#6{\xyTPIC@special{ia #1 #2 #3 #4 #5 #6}}
\xydef@\xytpic@sh#1{\xyTPIC@special{sh #1}}
%\xydef@\xytpic@psb#1{\xyTPIC@special{:[begin] #1}}
%\xydef@\xytpic@pse#1{\xyTPIC@special{:[end]}}
%
\xydef@\xytpic@wh{\xyTPIC@special{sh 0}}  % obsolete
\xydef@\xytpic@bk{\xyTPIC@special{sh 1}}  % obsolete

\xydef@\xyTPIC@special#1{\special{#1}}
\xydef@\xyTPIC@noisy#1{\W@{TPIC: #1}\special{#1}}
\xydef@\NoisyTPIC{\let\xyTPIC@special=\xyTPIC@noisy}
\DOCMODE)

Some effects may require a \TPIC\ |\special| to be placed both
before and after the <object>.

\DOCMODE(
\xydef@\xyTPICsplit@#1#2{\setboxz@h{#1\boxz@#2}}%
\DOCMODE)

\DOCMODE2%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

\TPIC\ uses units of `milli-inches' for coordinates,
but inches for dot-separations and dash-length.

\DOCMODE(
\xydef@\xytpic@pt#1{\dimen@=#1\divide\dimen@ by72 %
 \multiply\dimen@ by 1000 \advance\dimen@.5\p@
 \count@=\dimen@ \divide\count@\p@ }
\xydef@\xytpic@in#1{\dimen@=#1\divide\dimen@ by72 %
 \edef\next@{\expandafter\removePT@\the\dimen@}}%
\DOCMODE)

The \TPIC\ location is calculated relative to the current \TeX\ reference
point. Hence most \TPIC\ objects start at the $(0,0)$ location.

\DOCMODE(
\xydef@\xytpic@dot@@{\xytpic@pa00}
\xydef@\xytpic@width@{\xytpic@pt{\xylinethick@}%
 \expandafter\xytpic@pn\expandafter{\the\count@}}
%\xylet@\xytpic@width@=\relax

\xydef@\xytpic@line{%
 \xytpic@dot@@ \xytpic@pt{-\d@X}\count@@=\count@
 \xytpic@pt\d@Y \edef\next@{{\the\count@@}{\the\count@}}%
 \expandafter\xytpic@pa\next@ \xytpic@style@@ \xytpic@reset@ }

\xydef@\xytpic@solid@@{\xytpic@set@\xytpic@fp}
\xydef@\xytpic@dashed@@{\xytpic@in\xydashl@ \xytpic@dad}
\xydef@\xytpic@dotted@@{\dimen@=.5\xydashl@ \xytpic@in\dimen@ \xytpic@dtd}
\xydef@\xytpic@dad{\expandafter\xytpic@set@\expandafter{%
  \expandafter\xytpic@da\expandafter{\next@}}}
\xydef@\xytpic@dtd{\expandafter\xytpic@set@\expandafter{%
  \expandafter\xytpic@dt\expandafter{\next@}}}

\xydef@\xytpic@polysolid@{\xytpic@set@\xytpic@fp}
\xydef@\xytpic@polydashed@#1{\count@=#1 \xytpic@dad}
\xydef@\xytpic@polydotted@#1{\count@=#1 \xytpic@dtd}
\xydef@\xytpic@postpoly@{\xytpic@style@@ \xytpic@reset@}
\DOCMODE)

\DOCMODE2%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

\paragraph*{re-bindings}

This is similar to the mechanism used by the \PS\ back-end to rebind
``hooks'' to incorporate a switch according to the current value of
|\ifTPICspecials@|.

\DOCMODE(
\xydef@\TPICalternative@#1#2{%
\expandafter\global\expandafter\let\csname origxy#2@\endcsname=#1%
 \xdef#1{\noexpand\ifTPICspecials@
   \noexpand\expandafter\expandafter\noexpand\csname xytpic@#2@\endcsname
  \noexpand\else
   \noexpand\expandafter\expandafter\noexpand\csname origxy#2@\endcsname
  \noexpand\fi}}%
\DOCMODE)

Allow only one instance of |\setupxyTPIC@|; thereafter simply do
|\reloadxyTPIC@| to turn on anything that has been turned off.

\DOCMODE(
\xydef@\setupxyTPIC@{\xywarning@{using TPIC specials}%
 \TPICalternative@{\solid@}{solid}%
 \TPICalternative@{\dash@}{dashed}%
 \TPICalternative@{\point@}{point}%
 \TPICalternative@{\circhar@@}{circhar}%
 \TPICalternative@{\splinesolid@}{splinesolid}%
% \TPICalternative@{\splinedashed@}{splinedashed}%
% \TPICalternative@{\splinedotted@}{splinedotted}%
 \xywithoption{frame}{\xyinputorelse@{xytp-f}{}\xyuncatcodes}%
 \let\setupxyTPIC@=\reloadxyTPIC@ 
 \activateTPIC@ }

\xydef@\xyunloadTPIC@{\xywarning@{TPIC specials turned off}%
 \xywithoption{curve}{\xysetup@@\uninstallTPICcurves@ }%
 \xywithoption{line}{\xysetup@@\uninstallTPICline@ }%
 \xywithoption{frame}{\xysetup@@\uninstallTPICframes@ }%
 \TPICspecials@false
 \let\setupxyTPIC@=\reloadxyTPIC@ }

\xydef@\activateTPIC@{%
 \xywithoption{line}{\xysetup@@\installTPICline@}%
 \xywithoption{curve}{\xysetup@@\installTPICcurves@}%
 \xywithoption{frame}{\xysetup@@\installTPICframes@}%
 \TPICspecials@true }

\xydef@\reloadxyTPIC@{\xywarning@{TPIC specials back on}\activateTPIC@ }
\DOCMODE)

\DOCMODE2%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

\paragraph*{straight lines}

\DOCMODE(
\xydef@\xytpic@solid@{%
 \ifInvisible@ \let\next@=\no@@
 \else \DN@{\xyTPICstraight@{\xytpic@solid@@ \xytpic@line}}\fi
 \next@ }

\xydef@\xytpic@dashed@{\line@
 \def\Connect@@{\xyTPICstraight@{\xytpic@dashed@@ \xytpic@line}}}

\xydef@\xytpic@point@{\xytpic@dot@@\xytpic@fp\egroup
 \Invisible@false \Hidden@false \def\Leftness@{.5}\def\Upness@{.5}\ctipEdge@
 \def\Drop@@{\styledboxz@}%
 \def\Connect@@{\xyTPICstraight@{\xytpic@dotted@@ \xytpic@line}}}

\xydef@\xyTPICstraight@#1{\setupDirection@
 \edef\Creset@@{\cfromthec@ \pfromthep@ \DirectionfromtheDirection@}%
 \DN@##1##2{\def\checkoverlap@@{%
  \ifdim##1\X@p>##1\X@c \let\next@=\relax \fi
  \ifdim##2\Y@p>##2\Y@c \let\next@=\relax \fi}}%
 \edef\nextii@{{\sd@X}{\sd@Y}}\expandafter\next@\nextii@
 \noCshavep@@ \edef\Cshavep@@{\pfromthep@ \noexpand\resetDirection@}%
 \noCshavec@@ \edef\Cshavec@@{\cfromthec@ \noexpand\resetDirection@}%
 \ifHidden@\else
  \ifdim\Y@c>\Y@max \Y@max=\Y@c \fi  \ifdim\Y@p>\Y@max \Y@max=\Y@p \fi
  \ifdim\Y@c<\Y@min \Y@min=\Y@c \fi  \ifdim\Y@p<\Y@min \Y@min=\Y@p \fi
  \ifdim\X@c>\X@max \X@max=\X@c \fi  \ifdim\X@p>\X@max \X@max=\X@p \fi
  \ifdim\X@c<\X@min \X@min=\X@c \fi  \ifdim\X@p<\X@min \X@min=\X@p \fi \fi
 \ifInvisible@\let\next@=\relax	\else
  \DN@{\setboxz@h{\kern\X@c \raise\Y@c\hbox{#1}}%
   \ht\z@=\z@ \wd\z@=\z@ \dp\z@=\z@ {\Drop@@}}%
 \fi 
 \checkoverlap@@
 \ifdim\d@X=\z@ \ifdim\d@Y=\z@ \DN@{\relax}\fi\fi \next@
 \def\Cslidep@@{\noCslidep@@}\def\Cslidec@@{\noCslidec@@}%
 \def\Calong@@{\noCalong@@}\Creset@@ }
\DOCMODE)

\DOCMODE2%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

\paragraph*{spline curves}

\DOCMODE3%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

\noindent
Of the curves defined in the |xycurve| extension, only solid spline curves 
are supported. This is done by treating the spline as a polygon (poly-line) 
with many segments. The dotted or dashed variants do not work correctly. 

Implementations of \TPIC\ draw dashed polygons such that the start and 
finish of each segment is solid. Since these segments can be very short, 
the effect is simply to create a solid line. Similarly the shortness of the 
segments tends to give nothing at all for large portions of a dotted curve.
What is needed is an implementation whereby the on/off nature of a dashed
or dotted polygon is determined by the accumulated length, not the length 
along just the current segment.

\DOCMODE2%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

\DOCMODE(
\xydef@\xytpic@splinesolid@{\xyTPICspline@\xytpic@fp }
\xydef@\xytpic@splinedashed@{\xytpic@in\xydashl@\expandafter\xyTPICspline@
 \expandafter{\expandafter\xytpic@da\expandafter{\next@}}}
\xydef@\xytpic@splinedotted@{\xytpic@in{.5\xydashl@}\expandafter\xyTPICspline@
 \expandafter{\expandafter\xytpic@dt\expandafter{\next@}}}

\xydef@\xyTPICspline@#1{\setbox\splinebox@=\copy\voidb@x %\zerodot
 \SloppyCurves %\splinetol@=\xydashl@  % \xytpic@ip
 \global\xytpic@cnt=\@ne \xytpic@set@{#1}%
 \def\splineextra@@{\xyTPICspline@dot}%
 \def\xycrvdrop@{ }\def\xycrvconn@{}\splineset@@ \xytpic@style@@}

\xydef@\xyTPICspline@dot{\xytpic@pt{\X@c}\count@@=\count@
 \xytpic@pt{-\Y@c}\edef\next@{{\the\count@@}{\the\count@}}%
 \expandafter\xytpic@pa\next@ }
\DOCMODE)

\DOCMODE2%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

\paragraph*{line width}

\DOCMODE(
\xydef@\xyTPIClinewidth@#1{\xytpic@pt{#1}\edef\next@{\the\count@}}

\xydef@\installTPICline@{%
 \let\xylinewidth@@=\xylinewidth@
 \let\xylineSpecial@@=\xytpic@pn
 \let\transxyline@@=\xyTPIClinewidth@ }

\xydef@\uninstallTPICline@{\UnloadLine@}%
\DOCMODE)

\DOCMODE2%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

\paragraph*{circles and ellipses}

Here we catch circles and ellipses specified using the |\xycircle| command
from the |xycurve| extension. Since TPIC supports only solid circles, 
we catch it only when the <style> is either |{}| or |{-}|.

\DOCMODE(
\xydef@\xydoTPICcircle@#1{\DN@{#1}%
 \ifx\next@\empty\DN@{\xyTPICfullcircle@}%
 \else\expandafter\DNii@\expandafter{\addDASH@{}}%
  \ifx\next@\nextii@\DN@{\L@=\R@ \xyTPICfullcircle@}%
 \else\DN@{\dosolidcircle@{#1}}\fi\fi \next@ }

\xydef@\xyTPICfullcircle@{\xyTPICpartcircle@{00}0\twoPi@}%

\xydef@\xyTPICpartcircle@#1#2#3{%
 \xytpic@pt{\R@}\expandafter\DNii@\expandafter{\the\count@}%
 \xytpic@pt{\L@}\edef\next@{#1{\nextii@}{\the\count@}{#2}{#3}}%
 \expandafter\xytpic@ar\next@ }

\xydef@\qartPi@{0.7853981}
\xydef@\tartPi@{2.3561944}
\DOCMODE)

This replaces just the font character, called using |\circhar@@#1|.

\DOCMODE(
\xydef@\xytpic@circhar@#1{\xytpic@width@\ifcase#1%
  \xytpic@pt{\R@}\edef\next@{{{\the\count@}0}}%
  \expandafter\xyTPICcirchar@i\next@{\tartPi@}{\fullPi@}\kern\partroottwo\R@
 \or
  \xytpic@pt{\halfroottwo\R@}\edef\next@{{{\the\count@}0}}%
  \expandafter\xyTPICcirchar@i\next@{\halfPi@}{\tartPi@}\kern\halfroottwo\R@
 \or
  \xytpic@pt{\z@}\edef\next@{{{\the\count@}0}}%
  \expandafter\xyTPICcirchar@i\next@{\qartPi@}{\halfPi@}\kern\halfroottwo\R@
 \or
  \xytpic@pt{-\halfroottwo\R@}\edef\next@{{{\the\count@}0}}%
  \expandafter\xyTPICcirchar@i\next@0{\qartPi@}\kern\partroottwo\R@
 \or
  \xytpic@pt{-\halfroottwo\R@}\edef\next@{{{\the\count@}0}}%
  \expandafter\xyTPICcirchar@i\next@{-\qartPi@}0\kern\partroottwo\R@
 \or
  \xytpic@pt{\z@}\edef\next@{{{\the\count@}0}}%
  \expandafter\xyTPICcirchar@i\next@{-\halfPi@}{-\qartPi@}\kern\halfroottwo\R@
 \or
  \xytpic@pt{\halfroottwo\R@}\edef\next@{{{\the\count@}0}}%
  \expandafter\xyTPICcirchar@i\next@{-\tartPi@}{-\halfPi@}\kern\halfroottwo\R@
 \or
  \xytpic@pt{\R@}\edef\next@{{{\the\count@}0}}%
  \expandafter\xyTPICcirchar@i\next@{-\fullPi@}{-\tartPi@}\kern\partroottwo\R@
 \fi}

\xydef@\xyTPICcirchar@i#1#2#3{\L@=\R@ \xyTPICpartcircle@{#1}{#2}{#3}}
\DOCMODE)

\paragraph*{quadratic splines}

\DOCMODE(
\xydef@\xyTPIC@spline@ii@{\DN@{\xy@spline@ii}%
 \ifx\splineSTYLE@\empty\DN@{\xyTPICqspline@{0}}%
 \else\expandafter\DNii@\expandafter{\addDASH@{}}%
 \ifx\splineSTYLE@\nextii@\DN@{\xyTPICqspline@{0}}%
 \else\expandafter\DNii@\expandafter{\addDOT@{}}%
 \ifx\splineSTYLE@\nextii@\DN@{\xyTPICqspline@{-.5}}%
 \else\expandafter\expandafter\expandafter\DNii@\expandafter\expandafter
  \expandafter{\expandafter\addDASH@\addDASH@{}}%
 \ifx\splineSTYLE@\nextii@\DN@{\xyTPICqspline@{}}%
 \fi\fi\fi\fi
 \next@ }%

\xydef@\xyTPIC@accumulate{\xytpic@pt\X@c \count@@=\count@ 
 \xytpic@pt{-\Y@c}\edef\next@{{\the\count@@}{\the\count@}}%
 \expandafter\xytpic@pa\next@ }

\xydef@\xyTPICqspline@#1{\xytpic@width@
 \xytpic@in{#1\xydashl@}\expandafter\gdef\expandafter\xytpic@style@@
  \expandafter{\expandafter\xytpic@sp\expandafter{\next@}}%
 \save@ \cfromp@ \xyTPIC@accumulate
  \edef\smapp@@{\s@bot}\smapxy@i{\xyTPIC@accumulate}%
 \leave@ \xyTPIC@accumulate \xytpic@style@@ \xytpic@reset@
 \enter@{}\xy@spline@x }
\DOCMODE)

\DOCMODE(
\xydef@\installTPICcurves@{%
 \let\dosolidcircle@@=\xydoTPICcircle@
 \let\xy@spline@ii@@=\xyTPIC@spline@ii@
 }
\xydef@\uninstallTPICcurves@{%
 \let\dosolidcircle@@=\dosolidcircle@
 \let\xy@spline@ii@@=\xy@spline@ii }
\DOCMODE)

\DOCMODE2%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

\paragraph*{frames}
\DOCMODE(
 \xywithoption{frame}{\xyinputorelse@{xytp-f}{}}
\DOCMODE)

Implement color fills by reading from a |\TPICfillcolor|.
Implement pattern fills by reading from a |\TPICfillpatt|.
Read these whenever a fill is requested.


\DOCMODE(
\xydef@\uninstallTPICframes@{\UnloadFrames@}
\DOCMODE)

\DOCMODE2%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

\DOCMODE(
\xyendinput

% $Log: xytpic.doc,v $
% Revision 3.3  1996/12/18  09:50:38  ross
% adjusted Drop@@ for styles
% minor improvements to file-loading commands
%
% Revision 3.2  1995/09/19  18:21:41  ross
% Bug fix release.
%
% Revision 3.1  1995/09/05  20:36:33  ross
% Release!
%
% Revision 3.0  1995/07/07  20:13:19  ross
% Major release w/new User's Guide!
%
% Revision 2.13  1995/07/04  15:04:51  ross
% Ready for release of v3.
%
% NEW for version 3.1 by Ross Moore  1995/03/18.
% replaces xyps-col.doc
%
\DOCMODE)

\DOCMODE3%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

% Tell Emacs that this is a LaTeX document and how it is formatted:
% Local Variables:
% mode:latex
% fill-column:77
% fill-prefix:""
% End: