preview-latex in a nutshell
***************************

   Does your neck hurt from turning between previewer windows and the
source too often? This Elisp/LaTeX package will render your displayed
LaTeX equations right into the editing window where they belong.

   The purpose of preview-latex is to embed LaTeX environments such as
display math or figures into the source buffers and switch conveniently
between source and image representation.

   If preview-latex has not come in the form of a preinstalled package
for you, consult the `INSTALL' file for installation instructions
(especially, read the Prerequisites section).

1 What use is it?
*****************

   WYSIWYG (what you see is what you get) sometimes is considered all
the rage, sometimes frowned upon.  Do we really want it?  Wrong
question.  The right question is _what_ we want from it.  Except when
finetuning the layout, we don't want to use printer fonts for on-screen
text editing.  The low resolution and contrast of a computer screen
render all but the coarsest printer fonts (those for low-quality
newsprint) unappealing, and the margins and pagination of the print are
not wanted on the screen, either.  On the other hand, more complex
visual compositions like math formulas and tables can't easily be taken
in when seen only in the source.  preview-latex strikes a balance: it
only uses graphic renditions of the output for certain, configurable
constructs, does this only when told, and then right in the source code.
Switching back and forth between the source and preview is easy and
natural and can be done for each image independently.  Behind the scenes
of preview-latex, a sophisticated framework of other programs like
`dvipng', Dvips and GhostScript are employed together with a special
LaTeX style file for extracting the material of interest in the
background and providing fast interactive response.

2 Activating preview-latex
**************************

After installation, the package may need to be activated (and remember
to activate AUCTeX too).  In XEmacs, and in any prepackaged versions
worth their salt, activation should be automatic upon installation.  If
this seems not the case, complain to your installation provider.

   The usual activation (if it is not done automatically) would be

     (load "preview-latex.el" nil t t)

   If you still don't get a "Preview" menu in LaTeX mode in spite of
AUCTeX showing its "Command", your installation is broken.  One
possible cause are duplicate Lisp files that might be detectable with
`<M-x> list-load-path-shadows <RET>'.

3 Getting started
*****************

Once activated, preview-latex and its documentation will be accessible
via its menus (note that preview-latex requires AUCTeX to be loaded).
When you have loaded a LaTeX document (a sample document `circ.tex' is
included in the distribution, but most documents including math and/or
figures should do), you can use its menu or `C-c C-p C-d' (for
`Preview/Document').  Previews will now be generated for various
objects in your document.  You can use the time to take a short look at
the other menu entries and key bindings in the `Preview' menu.  You'll
see the previewed objects change into a roadworks sign when
preview-latex has determined just what it is going to preview.  Note
that you can freely navigate the buffer while this is going on.  When
the process is finished you will see the objects typeset in your buffer.

   It is a bad idea, however, to edit the buffer before the roadworks
signs appear, since that is the moment when the correlation between the
original text and the buffer locations gets established.  If the buffer
changes before that point of time, the previews will not be placed where
they belong. If you do want to change some obvious error you just
spotted, we recommend you stop the background process by pressing `C-c
C-k'.

   To see/edit the LaTeX code for a specific object, put the point (the
cursor) on it and press `C-c C-p C-p' (for `Preview/at point').  It
will also do to click with the middle mouse button on the preview.  Now
you can edit the code, and generate a new preview by again pressing
`C-c C-p C-p' (or by clicking with the middle mouse button on the icon
before the edited text).

   If you are using the `desktop' package, previews will remain from
one session to the next as long as you don't kill your buffer.  If you
are using XEmacs, you will probably need to upgrade the package to the
newest one; things are being fixed just as I am writing this.

4 Basic modes of operation
**************************

preview-latex has a number of methods for generating its graphics.  Its
default operation is equivalent to using the `LaTeX' command from
AUCTeX.  If this happens to be a call of PDFLaTeX generating PDF output
(you need at least AUCTeX 11.51 for this), then GhostScript will be
called directly on the resulting PDF file.  If a DVI file gets
produced, first Dvips and then GhostScript get called by default.

   The image type to be generated by GhostScript can be configured with

     M-x customize-variable RET preview-image-type RET
   
The default is `png' (the most efficient image type).  A special
setting is `dvipng' in case you have the `dvipng' program installed.
In this case, `dvipng' will be used for converting DVI files and
GhostScript (with a `PNG' device) for converting PDF files.  `dvipng'
is much faster than the combination of Dvips and GhostScript.  You can
get downloads, access to its CVS archive and further information from
its project site (http://savannah.nongnu.org/projects/dvipng).

5 More documentation
********************

After the installation, documentation in the form of an info manual
will be available.  You can access it with the standalone info reader
with

     info preview-latex

or by pressing `C-h i d m preview-latex <RET>' in Emacs.  Once
preview-latex is activated, you can instead use `C-c C-p <TAB>' (or the
menu entry `Preview/Read documentation').

   Depending on your installation, a printable manual may also be
available in the form of `preview-latex.dvi' or `preview-latex.ps'.

   Detailed documentation for the LaTeX style used for extracting the
preview images is placed in `preview.dvi' in a suitable directory
during installation; on typical teTeX-based systems,

     texdoc preview

will display it.

6 Availability
**************

The preview-latex project is now part of AUCTeX and accessible as part
of the AUCTeX project page (http://savannah.gnu.org/projects/auctex).
You can get its files from the AUCTeX download area
(ftp://ftp.gnu.org/pub/gnu/auctex).  As of AUCTeX 11.80, preview-latex
should already be integrated into AUCTeX, so no separate download will
be necessary.

   You will also find `.rpm' files there for Fedora and possibly SuSE.
Anonymous CVS is available as well.

7 Contacts
**********

Bug reports should be sent by using `M-x preview-report-bug <RET>', as
this will fill in a lot of information interesting to us.  If the
installation fails (but this should be a rare event), report bugs to
<bug-auctex@gnu.org>.

   There is a general discussion list for AUCTeX which also covers
preview-latex, look at `http://lists.gnu.org/mailman/listinfo/auctex'.
For more information on the mailing list, send a message with just the
word "help" as subject or body to <auctex-request@gnu.org>.  For the
developers, there is the <auctex-devel@gnu.org> list; it would probably
make sense to direct feature requests and questions about internal
details there.  There is a low-volume read-only announcement list
available to which you can subscribe by sending a mail with "subscribe"
in the subject to <info-auctex-request@gnu.org>.

   Offers to support further development will be appreciated.  If you
want to show your appreciation with a donation to the main developer,
you can do so via PayPal to <dak@gnu.org>, and of course you can arrange
for service contracts or for added functionality.  Take a look at the
`TODO' list for suggestions in that area.

