From: ross@macadam.mpce.mq.edu.au (Ross Moore)
Subject: PostScript Extensions to XY-pic
Originator: ross@macadam.mpce.mq.edu.au
Organization: School of MPCE, Macquarie University, Australia.
Date: Mon, 16 Nov 1992 12:30:51 GMT

This is to announce the release of xyps -- extensions to Kris Rose's XY-pic, for
constructing mathematical diagrams.
The extensions allow XY-pic to be used without loading the special fonts,
by using \special constructions for PostScript. Currently dvi-drivers
for (Rokicki's) dvips and Textures (Macintosh) are supported.
Some extra effects are possible; more work is planned.

Accompanying this posting is the README file.
Please mail me direct for enquiries, comments and bug reports.

Ross Moore
ross@macadam.mpce.mq.edu.au

****************************************************************************



This is the first release version of... 

		xyps -- PostScript extensions to XY-pic.

				by 
			Ross Moore, Sydney, Australia
			ross@macadam.mpce.mq.edu.au

XY-pic is an excellent package of macros for creating mathematical diagrams,
written by Kris Rose of DIKU, Copenhagen, Denmark:  kris@diku.dk
available from  ftp.diku.dk[129.142.96.1]

	xyps  replaces the need to load the special fonts required for XY-pic;
instead of these fonts xyps uses the \special construction to put PostScript
commands directly into the .dvi file. 

To use this \special feature requires a dvi-driver which recognises these
constructions; e.g.  dvips  by Tomas Rokicki <rokicki@neon.stanford.edu>

xyps currently supports:  
			dvips :    Tomas Rokicki <rokicki@neon.stanford.edu>
			Textures : (Macintosh only)   Blue Sky Research


This version 2.6 works with XY-pic, version 2.6 only.

A version 2.7 will appear shortly to accomodate the improvements and new features 
of version 2.7 of  XY-pic .

*********************************************************************************

To use xyps, put the following into your TeX source code, after the commands to
load xypic:

\input xypicPSmods      % loads patches to xypic for version 2.6
			% unnecessary in later versions 2.7+

\UsePostScriptSpecials	% if dvips is to be used; else
\UseTexturesSpecials	% if Textures is to be used.

%%% these latter commands must come before the first \diagram in which the 
%%% PostScript \specials are required.

If used globally then \UsePostScriptSpecials or \UseTexturesSpecials will cause
the \specials to be generated in all subsequent diagrams. 
If used locally, e.g.
	$$\UseTexturesSpecials\diagram....\enddiagram$$
then they will be used only in that diagram; fonts being required for others.

As only one dvi-driver can be used, then after \UsePostScriptSpecials or 
\UseTexturesSpecials has been specified, any subsequent uses of either 
command will deliver the same type of \special as has already been specified.



For details on the source code, adequately documented :-) , see the file xyps.doc


*********************************************************************************

				SPECIAL FEATURES:

1. PostScript header

A header file for most of the PostScript commands can be loaded with  dvips .
To use this, specify:
	\UsePostScriptSpecials
	\xyDVIPSheader

By default, the required file  xypsdict.ps  will be loaded, provided dvips can
find a path to it. If an alternative name is required, change the definition
of  \xyPSdictname  e.g. default is  \gdef\xyPSdictname{xypsdict.ps} .

This feature is NOT available for Textures.



2. Overlapping lines

The effect of overlapping lines can be simulated in PostScript; that is, if two
crossing lines are to be drawn, the latter can be viewed as passing over the former.
The lower line (first drawn) stops before the crossing and continues on the other
side, the upper line (latter drawn) is unbroken.

This effect is achieved by specifying:

	$$\overlaplines\diagram...\enddiagram$$   % locally for a single diagram

or globally

	\overlaplines

for all subsequent diagrams. There is also  \nooverlaplines  to cancel this effect.

For this to work, the file  xypsadds.tex  must be available to load via \input .



3. More to come

Proposed further development is to be wide-ranging:
e.g. Braids, Links, Ribbons, Feynmann diagrams, Penrose (Bug) diagrams, ...

Appropriate intuitive macros are planned for the generation of such diagrams.
Any suggestions or comments on what is/is not `intuitive` would be most greatfully
received; consensus, biased a little by my own views :-), will rule on these issues.

Extensions involving graphics which are not easily  constructed in TeX will be added
to the file:  xypsadds.tex  (currently version 1.0).

Extensions which can be appropriately constructed in TeX may become part of XY-pic.
Kris Rose and myself plan to keep xypic and xyps concurrent and compatible.


*********************************************************************************

Use and enjoy. 

Any comments and bug reports will be greatfully accepted, and acted
upon where necessary.

Ross Moore
Mathematics Department
Macquarie University
Sydney, Australia

ross@macadam.mpce.mq.edu.au
-- 
Ross Moore                        Phone : + 61 2 805-8955
School of Math,Phys,Comp,Elec     Fax   : + 61 2 805-8983
Macquarie University  NSW  2109   Also  :  
Australia                         EMail : ross@macadam.mqcs.mq.oz.au