%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%main
<head>XaoS</head>
<center>
Welcome to XaoS - a real-time fractal zoomer. 
</center>

<dl>
<dt><a about>About XaoS</a>
<dd>Learn who's behind XaoS and how you can help.

<dt><a start>Getting started</a>
<dd>Start here to learn how to use XaoS's basic features.

<dt><a support>Getting support</a>
<dd>How to report problems and get help from the XaoS community.

<dt><a sffe>User formulas</a>
<dd>Learn how to render your own formulas in XaoS.

<dt><a video>Encoding videos</a>
<dd>Learn how to create videos from your XaoS animations.

<dt><a drivers>Platform-specific documentation</a>
<dd>XaoS runs on many platforms. Read instructions specific to yours.

<dt><a format>XaoS's file format</a>
<dd>Learn how to tweak your saved fractals and animations.

<dt><a menus>Menus, commands and parameter index</a>
<dd>An in-depth discussion of all of XaoS's commands.
</dl>

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%about
<head>About XaoS</head>
<notex>
XaoS is free software. You are welcome to redistribute it under the terms of
the <a gpl>GNU General Public License</a>. This also means that you may get 
<emph>sources</emph> and help improve XaoS through an open 
<a devel>development process</a>.
</notex>
<head>Credits</head>
(alphabetically)
<dl>
<dt>Lucio Henrique de Araujo (lucio.matema@gmail.com)
<dd>Brazilian/Portuguese translation
<dt>Eric Courteau (ecourteau@cplus.fr)
<dd>francais.cat (translation of tutorials)
<dt>Jean-Pierre Demailly (Jean-Pierre.Demailly@ujf-grenoble.fr)
<dd>Updates for French translation
<dt>Radek Doulik (rodo@atrey.karlin.mff.cuni.cz)
<dd>TK interface, windowid patches
<dt>Martin Dozsa (madsoft@centrum.cz)
<dd>cs.po (Czech translation of menus)
<dt>Arpad Fekete (Fekete.Arpad.2@stud.u-szeged.hu)
<dd>some new fractals, and the 'More formulae' menu
<dt>Zelia Maria Horta Garcia (zeliagarcia@seed.pr.gov.br)
<dd>Brazilian/Portuguese translation
<dt>Tim Goodwin	(tgoodwin@cygnus.co.uk)
<dd>english.cat corrections
<dt>Ben Hines
<dd>autoconf suggestions, Mac OS X port
<dt>Jan Hubicka	(jh@ucw.cz) 
<dd>Zooming routines, ugly interface, palettes, drivers, autopilot, filters, documentation, tutorials etc.
<dt>Jens Kilian	(jjk@acm.org)
<dd>BeOS driver, deutsch.cat
<dt>Thomas A. K. Kjaer (takjaer@imv.aau.dk)
<dd>OS/2 ports (320x200 graphics and AA-lib)
<dt>Zoltan Kovacs (kovzol@math.u-szeged.hu)
<dd>Internationalization, Hungarian translations, finalizing version 3.1, bug fixes, web design, current maintainer
<dt>Zsigmond Kovacs (kovzsi@gmail.com)
<dd>Fractal examples
<dt>J.B. Langston III (jb-langston@austin.rr.com)
<dd>Native Mac OS X port (from version 3.2.2); web redesign; co-maintainer
<dt>Andreas Madritsch (amadritsch@datacomm.ch)
<dd>New fractal types, bailout, many fixes
<dt>Mateusz Malczak (xaos@malczak.info)
<dd>User formula evaluation library
<dt>Giorgio Marazzi (gmarazzi@vtr.net)
<dd>Improvements and fixes for espanhol.cat
<dt>Thomas Marsh (thomas.marsh2@gmail.com)
<dd>First zoomer, formulae, planes, X11 driver, inversions, many ideas
<dt>Dominic Mazzoni (dmazzoni@cs.cmu.edu)
<dd>Macintosh port (version 2.0)
<dt>David Meleedy
<dd>Grammatical and spelling fixed version of <tt>xaos.6</tt>
<dt>Paul Nasca (zynaddsubfx@yahoo.com)
<dd>Ministatus improvement
<dt>Nix (nix@esperi.demon.co.uk)
<dd>Grammatical and spelling fixed version of <tt>xaos.hlp</tt> and other files
<dt>Terje Pedersen (terjepe@login.eunet.no)
<dd>Amiga port
<dt>Cesar Perez (oroz@users.sourceforge.net)
<dd>Spanish translations
<dt>Fabrice Premel (premelfa@etu.utc.fr)
<dd>Periodicity checking
<dt>Jan Olderdissen (jan@olderdissen.com)
<dd>Win32 port
<dt>Ilinca Sitaru (ilinca.sitaru@gmail.com)
<dd>Romanian translation
<dt>Daniel Skarda
<dd>Fractal examples
<dt>Andrew Stone (Stone Design - www.stone.com)
<dd>Videator Support, Cocoa improvements, performance mode, bug fixes
<dt>Marton Torok (marton.torok@gmail.com)
<dd>Small fixes for pipes
<dt>Pavel Tzekov (paveltz@csoft.bg)
<dd>Win32 support
<dt>Charles Vidal
<dd>Tcl/Tk interface
<dt>Tapio K. Vocaldo (taps@rmx.com)
<dd>Macintosh port
<dt>Tormod Volden
<dd>Fixes for X11 driver to improve compatability with Xorg, XScreenSaver, Beryl and Compiz
<dt>Philippe Wautelet (p.wautelet@fractalzone.be)
<dd>Bug fixes for version 3.1.1, French translation, gcc 4.0 fixes
<dt>Sergio Zanchetta
<dd>Italian translation
</dl>
<head>Included Software</head>
XaoS uses the following libraries. These libraries may be included
with some binary distributions of XaoS.
<p>
<emph>gettext 0.17</emph><br>
Website: <tt>http://www.gnu.org/software/gettext/</tt><br>
Copyright (C) 1995-1997, 2000-2007 Free Software Foundation, Inc.<br>
License GPLv3+: GNU GPL version 3 or later (http://gnu.org/licenses/gpl.html)<br>
This is free software: you are free to change and redistribute it.<br>
There is NO WARRANTY, to the extent permitted by law.
<p>
<emph>GNU Scientific Library 1.11</emph><br>
Website: <tt>http://www.gnu.org/software/gsl/</tt><br>
Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007 The GSL Team.<br>
License GPLv3+: GNU GPL version 3 or later (http://gnu.org/licenses/gpl.html)<br>
This is free software: you are free to change and redistribute it.<br>
There is NO WARRANTY, to the extent permitted by law.
<p>
<emph>libpng 1.2.25</emph><br>
Website: <tt>http://www.libpng.org/pub/png/libpng.html</tt><br>
Copyright (c) 1998-2008 Glenn Randers-Pehrson<br>
Copyright (c) 1996-1997 Andreas Dilger<br>
Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%start
<head>Getting Started</head>

<a controls>Basic controls</a><br>
Learn the basic commands to control XaoS.

<p>
<tutor fractal.xaf>An introduction to fractals</tutor><br>
Try this animated tutorial if you don't know what a fractal is. If 
you are new to XaoS you should try it too, since it is quite a good example 
of XaoS's features. 

<p>
<tutor features.xaf>XaoS features overview</tutor><br>
Watch this tutorial to discover more of XaoS's features.

<p>
Both the tutorials are divided into chapters and available from help menu, 
so you don't need to watch them all at once (they are about half an hour long).

<p>
<a tutorial>XaoS Overview</a><br>
A written introduction to all of XaoS's features.


%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%support
<head>Support</head>
XaoS is a community-supported free software project.

<head>Home Page</head>
Site: <tt>http://xaos.sourceforge.net</tt><p>

Check the Xaos home page for the latest news and information about 
XaoS and to download the latest versions.

<head>Users' Discussion Group</head>
Site: <tt>http://groups.google.com/group/xaos-users</tt><p>

The xaos-users discussion group on Google Groups provides a place for XaoS 
users to help each other get the most out of XaoS. XaoS developers also 
monitor this discussion and answer questions from time to time.<p>

You can browse the archives freely but you must join the group in order to 
post. However, Google Groups provides a range of options for participation 
from a traditional mailing list to a completely web-based forum, so you 
don't have to get emails if you don't want to.<p>

If you have a question or problem, please feel free to ask for help. We 
also encourage you to share examples (.xaf or .xpf files), hints and 
tips. If you have a gallery of images created using XaoS, feel free to 
post a link to the group.


<head>Developers' Discussion Group</head>

Site: <tt>http://groups.google.com/group/xaos-devel</tt><p>

The xaos-devel discussion group on Google Groups is where XaoS developers 
discuss and coordinate the further development of XaoS. XaoS users are 
welcome to monitor this forum as well, but general discussion and requests 
for help should be posted to the Users' Discussion Group instead.


<head>Issue Tracker</head>

Site: <tt>http://code.google.com/p/gnuxaos/issues/list</tt><p>

Issues are tracked on Google Code. If you think you have found a bug in 
XaoS or have an idea for a great new feature, please let us know about it. 
However, if you're not sure how to submit a useful issue report, please ask 
on the xaos-users discussion group first (see above).<p>

Please don't submit duplicate issues. Search the existing ones first to make 
sure nobody has already reported it. You can add additional information about 
a bug by entering a comment on an existing bug. You can also express your 
interest in an issue by using the "Star" function on Google Code. This lets 
the developers know how many users are interested in an issue and also allows 
you receive status updates.<p>

The developers will do their best to respond to issues in a timely manner. 
However, keep in mind that XaoS is developed on a volunteer basis and the 
developers work on it in their spare time. Therefore, we can't guarantee that 
issues will be addressed in a certain timeframe.<p>



%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%devel
<head>Development</head>
XaoS is free software. One of the most significant rights its <a gpl>license</a>
grants to you is the right to <emph>freely get, study and improve</emph> its
source code, which is available from the XaoS homepage.
<p>
XaoS has an open development model. All development is coordinated via Google Code
at <tt>http://gnuxaos.googlecode.com/</tt>. Development versions are
available via Subversion at <tt>https://sourceforge.net/scm/?type=svn&group_id=5771</tt>,
so if you are interested in the future of XaoS, give the latest source a try! We also 
have a several <a support>discussion groups</a>, which you can join if you want to 
discuss XaoS with others or participate in the development process.
<p>
If you want to do some development, you are encouraged to send your work back
to the <a about>authors</a>; if it is well done, it will be added to the
next release. All changes should be submitted to the Google Code issue tracker.
<p>
XaoS is quite easily extensible. You might want to
read a bit about its internals in the file <emph>doc/xaosdev.info</emph>.
XaoS is also portable, so if it doesn't work on your favorite platform (or
there is just an old version available), you could quite easily port it.
<p>
<head>Volunteer Opportunities</head>
XaoS needs volunteers to make it the best fractal program it can be! 
You don't have to be a programmer to help.  The following 
tasks open to volunteers:

<p>Improving the documentation via the Wiki (and improving the DokuWiki converter).
<p>Compiling binaries for your favorite operating system.
<p>Reviewing the source code, adding comments, and checking lines which generate warnings during compilation.
<p>Creating additional tutorials and examples.
<p>Translating XaoS into your language.
<p>Implementing feature requests.
<p>Fixing outstanding bugs.
<p>If you would like to volunteer, join the discussion groups and let us know. We would be happy to help you get started!


%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%sffe usrform usrformInit
<head>Using user formulas</head>
<p>
XaoS supports entering your own custom formulas.
Select <tt>User formula</tt> from the <tt>Fractal</tt> menu to define a 
custom fractal formula.  Select <tt>User initialization</tt> to change 
the sequence starting point <emph>z0</emph>. By default <emph>z0</emph> 
is set to 0. User formulas should be interpreted as functions in the form<br>
<emph>Z(n+1) = formula (Z(n), Z(n-1), C)</emph>.
<p>
In user formulas, as shown above, three variables are available:<br>
<dl>
<dt>z
<dd>current sequance point Z(n)
<dt>c
<dd>current plane 'point'
<dt>p
<dd>previous sequence point Z(n-1)
</dl>
<p>
Format for complex numbers is <emph>{re;im}</emph><br>
eg. {3;2} is complex number 3+2i.
<p>
Available functions are listed below:
<dl>
<p>
<dt>basic operations
<dd>+, -, *, /
<p>
<dt>basic trigonometry
<dd>sin, cos, tan, cot<br>
asin, acos, atan, acot<br>
sinh, cosh, tanh, coth
<p>
<dt>Exponential and logarithmic functions
<dd>exp<br>
log - natural logarithm<br>
log2, log10<br>
logN (base, z) - logarithm of base N (where N is integer)<br>
logCN (base, z) - logarithm of base CN (where CN is complex)
<p>
<dt>power functions
<dd>powi - power with integer exponent (fastest)<br>
powd - power with real exponent<br>
powdc - power with complex exponent<br>
pow - same as powd<br>
sqr - square
<p>
<dt>square functions
<dd>sqrt - square root of a complex number<br>
rtni (z, n, i) - i-th root of n-th orgder
<p>
<dt>other functions
<dd>rand (max) - random real number in range [0, max)<br>
inv - inverse<br>
abs - absolute value<br>
re - real part<br>
im - imaginary part
</dl>
<p>


%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%video

<head>How to encode video files from XaoS</head>
<p>
To create a video, make and <tt>xaf</tt> file first (the easiest way to do this is
to use the <emph>record</emph> function in the file menu). Then you need to render 
the animation. XaoS can output sequences of ordinary <tt>PNG</tt> images, that
can later be used by a video encoder.
<p>
<head>Generating image sequences for video</head>
<p>
To generate an image sequence, choose <emph>Render Animation</emph> from the <emph>Misc</emph>
menu.  You can also use the following command on the command line:
<p><tt>
xaos -render [filename] -size 352x240 -antialiasing 
       -renderframerate 24 -basename [basename]
</tt><p>
<emph>File to render</emph> (<tt>[filename]</tt>) is the name of the <tt>xaf</tt> file,
<emph>Basename</emph> (<tt>[basename]</tt>) is the name used as the base filename for rendered images.  This should also include the path where you want to save the images.
XaoS adds a four digit sequence number and <tt>.png</tt> extension to this name automatically.
<p>
You might also want to change the resolution. Make sure that the resolution
you choose is supported by the video codec you wish to use.
<p>
The framerate can also be altered. Make sure you choose a framerate that is supported by
the video codec you wish to use.
<p>
<emph>Antialiasing</emph> (<tt>-antialiasing</tt>) is used to produce anti-aliased images. 
It takes a much longer
time and much more memory to calculate them, but resulting images are better
for video compression and they result in a much smaller video file.
(the same is true of <emph>JPEG images</emph>)
<p>
On the other hand, the other XaoS rendering option <emph>Always Recalculate</emph> (<tt>-alwaysrecalc</tt>) (which disables
XaoS's zooming optimizations) is <emph>not recommended</emph>. If that's used, the
sequence of animation then contains quite a lot of extra information, which
increases size of video file, but because of the codec's lossy compression it is hard
to see any difference, so it's not worth it.
<head>Rendered files</head>
Once you start it, XaoS will generate thousands of frames. They take quite
a long time to calculate and save, and consume plenty of disk space.
(e.g. to render part 1 of the tutorial you need about 60MB and half an hour of time).
<p>
All images are named <tt>[basename]framenum.png</tt>. For example <tt>intro0001.png</tt> is
the first frame of the animation intro. If consecutive frames are the same, XaoS
doesn't save them, so some frames may be missing. If your encoder can't handle
that, you will need to write a simple script which will fill in the gaps by means
of <tt>mv</tt> or symbolic linking.
<p>
A list of all filenames is saved into the file <tt>[basename].par</tt>, where each line is
the name of one frame. The names repeat here if necessary, so you can use this
file to supply filenames to the encoder.
<head>Encoding videos</head>
Once XaoS has generated the png files for each frame of the animation, you
can use a third-party video encoder to convert the sequence of images into
a video file.  We currently recommend the following encoders, which support
a wide variety of video codecs and file formats:
<dl>
<dt>ffmpeg
<dd>Available from: <tt>http://ffmpeg.mplayerhq.hu/</tt><br>
Instructions: <tt>http://ffmpeg.mplayerhq.hu/faq.html#SEC12</tt>
<dt>mencoder
<dd>Part of mplayer, available from: http://www.mplayerhq.hu/<br>
Instructions: <tt>http://www.mplayerhq.hu/DOCS/HTML/en/menc-feat-enc-images.html</tt>
</dl>
These are both command line tools.  If you prefer a graphical tool, you may
prefer Quicktime Pro from Apple (http://www.apple.com/quicktime/pro/). However,
this software costs approximately US$30, and the authors of XaoS have no
experience with it.  Although QuickTime may be easier to use, the two free 
encoders above are just as capable once you learn how to use them.

<p>
Note: we used to recommend <a berkeley>Berkeley parallel MPEG encoder</a> to 
encode the generated png files into MPEG videos.  We have kept 
the instructions mainly for historic purposes.


%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%berkeley
<head>Berkeley parallel MPEG encoder</head>

This is the encoder we used to recommend. However, it has not been updated
for a very long time and no longer appears to compile on modern systems.
Also, there are much more modern codecs available that provide better video
quality and compression rates.  Still, we have kept the following 
instructions mainly for historic purposes.
<p>
It is available at Berkeley's FTP site <tt>mm-ftp.CS.Berkeley.EDU</tt> and called
<tt>mpeg_encode1.5b</tt>
<p>
It has lots of options to tune, so you should spend quite a lot of time
playing with this. The configuration I use is in file <tt>doc/mpeg.param</tt>.
<p>
I've also made some patches that makes possible to use the pattern and motion
files generated from XaoS. The patch is in <tt>doc/mpeg_encode.patch</tt>. So if
you want to use these features (they are <emph>EXPERIMENTAL</emph>) you might apply this
patch and recompile the encoder.
<p>
Once you filled the <tt>mpeg.param</tt> file (see comments inside), you should render
sequence using <tt>mpeg_encode [filename]</tt> and with luck you are done.

<head>Pattern file</head>

Some other files are generated as well. A <emph>pattern file</emph> is generated,
which contains a <emph>recommended order of P, B and I frames</emph>.
<p>
MPEG sequence consist of these three frames. The <emph>I frames</emph> are just images
saved in a format similar to JPEG files. 
<p>
The <emph>P frames</emph> are images which are constructed as a delta from the
previous one (the latest I or P frame). In case consecutive frames are similar
(and in animations they often are), a P frame takes much less disk space
than an I frame.
<p>
The <emph>B frames</emph> are constructed from the nearest previous P or I frame
and the next P or I frame. They take even less disk space, but they are quite
hard to encode. Also they are <emph>not used as previous frames</emph>,
so their information is lost once they are displayed. They are usually
rendered at lower quality than a P or I frame and used just to interpolate
nearest frame and make animation smoother. It is generally not a good idea
to make a whole sequence just from B frames.
<p>
Using just P frames is generally not a good idea. It makes the file shorter,
but to jump into Nth frame of animation you need to <emph>recalculate all P and B frames
since latest I frame</emph>. Decoders often want to jump to some frame (when
the user asks, or when they can't decode a sequence in time and must skip
some), so you need to have some I frames in the animation to make this possible.
The latter reason means that you need to place them quite often. Usually
they are used for every 15th frame or thereabouts. Because they cost quite a lot,
in my animations I usually use every 27th frame. To set this distance
use <tt>-iframedist</tt> option. It should be a multiple of 3.
<p>
XaoS generates a recommended order of frames based on its knowledge of
fractal motion. Situations where the screen doesn't move at all are rendered
just from P frames (since jumping is usually not required here); in situations
where the screen changes completely (at least in XaoS's opinion) I frames are used
and in other cases, a standard sequence <tt>IBBPBBPBBPBBP...</tt> is used.
<p>
If your encoder supports this, you should supply this pattern for encoding to
squeeze out some bytes.

<head>Motion vector files</head>

XaoS also generates a motion vector recommendation for the encoder. This is
useful for encoding of B and P frames.
<p>
If some objects on the screen are moving at a constant speed, motion vectors
can store that speed, so no image needs to be saved to represent that change.
<p>
Calculating this motion vector is a very significant task. If you guess
them well, you increase quality and reduce file size, which is always great.
Calculation also takes lots of CPU and it is hard to get optimal vectors (it
just takes too long).
<p>
XaoS knows how the fractals move, so it can calculate this vectors quite
easily. XaoS saves this information into <tt>*.p</tt> and <tt>*.b</tt> files. (<tt>*.p</tt> are for P
frames, <tt>*.b</tt> are for B frames). If your encoder supports this, you should
provide this vector to increase quality. They are <tt>not exact</tt> (XaoS can make
mistakes); the encoder should try to find its own vectors, then try XaoS's ones,
and pick whichever is better.
<p>
This technique saves quite a lot of bytes in fast zooming/un-zooming
animations (where images move more than 3 or 5 pixels per frame--since
most programs look 10-20 pixels around each point for motion vectors).
<p>
To enable saving of motion vector files, add the option
<tt>-rendervectors</tt>.


%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%controls
<head>Basic controls</head>
By default the mouse buttons work in the following way:
<p>
<dl>
<dt>left<dd>zoom in
<dt>right<dd>zoom out  
<dt>middle<dd>move fractal in a drag-and-drop fashion
</dl>
<p>
<emph>Note:</emph> Since most Macs only have one button mice, these controls
are emulated on Mac OS X using modifier keys.  See the help section on 
<a cocoa>Mac OS X</a> for details.
<p>
This behavior can change. If you enable rotation, the first button is used for rotating
fractals. Also, in fast Julia mode, the first button is used to change the seed.
<p>
If you don't have a middle button, press both buttons to enable
emulation.
<p>
After few minutes of zooming you will probably exceed the precision and the
fractals will get boring. If you are getting strange big rectangles on the screen,
you probably reached the numeric limit: there is no way to avoid this except
un-zoom back and choose a different area. It doesn't hurt so much, since you have
zoomed approximately 64 051 194 700 380 384 times, so there are quite a lot of areas to
explore. Algorithms with unlimited precision exist, but they are still too
slow for real-time zooming.
<p>
The other possibility is that you have reached the iteration limit. The fractal is
calculated approximately, and in this case you need to increase number of
iterations used for approximation (and decrease the speed in the process).
This is done from the menu or using the arrow keys <emph>Left</emph> and <emph>Right</emph>.
<p>
An <emph>Up</emph> and <emph>Down</emph> keys should be used to change zooming
speed. Note that higher speed costs more and image will be blocky.
<p>
This behavior can also change. With palette cycling enabled, <emph>Left</emph>
and <emph>Right</emph> keys change cycling speed; in continuous
rotation they change rotation speed.
<p>
All other functions are available from the menu, which (in the default
configuration) are displayed when you move the mouse to the top of the
screen/window. It is useful to learn the shortcut keys, which are
shown in gray next to the menu items they trigger.


%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%writehelp
<head>How to write XaoS help files</head>
XaoS help is stored in the file <tt>help/xaos.hlp</tt>. It is divided into parts,
each part being started by a <emph>keyword</emph>. In the help file keywords are
written as <tt>%keyword</tt>
<p>
If you are writing documentation about some command in the XaoS function
registry, use the same keyword as the name of the command in order to make
context sensitive help work.
<p>
<notex>
The help file is written in a special format called <a xshl>xshl</a>.
</notex>

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%xshl
<head>xshl</head>
<emph>Xshl</emph> stands for <emph>XaoS simple hypertext language</emph>. It
uses similar tags to HTML. It is simpler and more restrictive in order to
make it easy to parse using various scripts. In C code you can use the
library present in <tt>src/util/xshl.c</tt> to parse it.
<p>
The following tags are supported:
<p>
<dl>
<dt>head
<dd>make headings (should be at the beginning of the page, at least)
<dt>emph
<dd>emphasize
<dt>tt
<dd>Use non proportional font
<dt>br
<dd>Break line
<dt>p
<dd>Next paragraph
<dt>dl
<dd>Definition list
<dt>dt
<dd>Definition tag (should be used only inside a definition list)
<dt>dd
<dd>Definition description (should be used only inside a definition list)
<dt>center
<dd>align to center
<dt>right
<dd>align to right
<dt>red
<dd>change color to red (should not be used in help files)
<dt>black
<dd>change color to black (should not be used in help files)
<dt>white
<dd>change color to white (should not be used in help files)
<dt>a name
<dd>link to other help page
<dt>tutor name
<dd>activate tutorial
<dt>notex
<dd>Ignore this in texinfo manuals
</dl>



%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%format
<head>XaoS's file format</head>
This section describes the format used by XaoS for animations, configuration
files and saved positions. All these files have a common format, designed
to be easily readable, to allow manual editing of files and easy conversion by
other programs.
<p>
I also taken care to make it easily extensible for future versions of XaoS
so I hope there will not be many incompatibilities between various XaoS
versions.
<p>
The format is a simple set of commands executed sequentially. XaoS does not provide
any variables/cycles as usual scripting languages do, but future extension to
full-blown Scheme should be easy since the format uses Scheme-like syntax.
The syntax of every command is:
<p>
<tt>(command_name </tt><emph>[param1] [param2]</emph><tt>)</tt>
<p>
where parameters are optional and separated by whitespace (an arbitrary number
of spaces, tabs and newlines). The parameters can have the following types:
<p>
<dl>
<dt>integer
<dd>number w/o decimal point (<tt>123</tt>)
<dt>float
<dd>floating point number in decimal notation with optional exponent (<tt>1.23E2</tt>)
<dt>keyword
<dd>text started by quote <tt>'</tt>. It is used to pass various string constants 
like formula name (<tt>'mandel</tt>) Quote is required for scheme compatibility
<dt>string
<dd>Text inside double quotes. The only parameter that should contain whitespace
<dt>boolean
<dd><tt>#t</tt> for true or <tt>#f</tt> for false
</dl>
<p>
There is a complete description of all XaoS functions (with some examples) and an
index of functions in the <a menus>XaoS registry</a>. You may particularly want
to read about the <a animf>animation functions</a>. Also, the following functions
are significant:

<dl>
<dt>load
<dd>
This function loads and interprets a file. It works similarly to <tt>#include</tt>
in C.
<dt>initstate
<dd>
Available in version 3.0 and above, this function resets XaoS's state to default
values. This command should be at the beginning of each animation file,
since otherwise some stuff previously enabled by user could cause unexpected
effects. State is not reset by default before playing animations since it would
make it impossible to write macros. Current versions don't really need macros, but
in future versions, when the Scheme programming language will be available, this
should be a much more interesting subject.
<dt>usleep
<dd>
This function waits for a selected amount of time(in usec) before processing the
next command. The screen is recalculated and displayed at the beginning of
the sleep if necessary. The remaining time is spent by waiting, calculating if
necessary, or performing any animation you entered via animation commands.
<dt>wait
<dd>
Waits until the animation or image rendering is complete. Do not call this
function when zoom, or continuous rotation is active otherwise deadlock happens. It is
a good idea to call it immediately before text subtitles are displayed, since it looks
ugly when they are displayed over a blocky unfinished fractal. Because the
degree of blockiness at a given instant is a function of your machine speed,
it may look nice for you but ugly for others with slower machines. Also
you should call this after an animation is performed, before the switch to another
fractal happens; since the switch involves calculation, the screen is stopped
for a while and an unfinished fractal there looks ugly.
You should also call it, when you want to do something as soon as possible.
</dl>
<p>
Example:
<p><tt>
;configure everything for the first frame<br>
(inistate)<br>
(palette 1 1163254293 0)	;custom palette<br>
(cycling #t)			;enable cycling<br>
(cyclingspeed 7)<br>
(maxiter 276)			;higher number of iterations<br>
(range 3)			;default range for solid guessing<br>
(usleep 1000000)		;second frame starts here<br>
(moveview -1.8101154154614007889 -8.2687205907162041209E-05)<br>
				;just move the image<br>
(usleep 1000000)		;third frame<br>
(morphview -1.8101154154614007889 -8.2687205907162041209E-05<br>
            6.277210971069452361E-10 6.2772109785334669875E-10)<br>
				;10 seconds of zooming into selected<br>
				rectangle<br>
(usleep 100000000)<br>
</tt><p>
The best way to learn XaoS command language is probably to read position files
and modify them. For example, to create zooming animation from the original
file:
<p><tt>
(initstate)<br>
(defaultpalette 0)<br>
(formula 'mandel)<br>
(view -1.64128273713 -5.50393226816E-05 9.69332308848E-08<br>
9.69332308834E-08)<br>
</tt><p>
Just change the <tt>view</tt> command to <tt>morphview</tt>, and add <tt>usleep</tt>:

<p><tt>
(initstate)<br>
(defaultpalette 0)<br>
(formula 'mandel)<br>
(morphview -1.64128273713 -5.50393226816E-05 9.69332308848E-08<br>
9.69332308834E-08)<br>
(usleep 10000000)<br>
</tt><p>
The following code produces Julia morphing in the real axis:
<p><tt>
(initstate)<br>
(fastjulia #t)<br>
(juliaseed -2 0)<br>
(morphjulia 2 0)<br>
(usleep 2000000)<br>
</tt><p>

And following is the ``rotozooming'' animation:

<p><tt>
(initstate)<br>
(fastrotate #t)<br>
(morphview -1.64128273713 -5.50393226816E-05 9.69332308848E-08<br>
9.69332308834E-08)<br>
(morphangle 300)<br>
(usleep 10000000)<br>
(wait)<br>
(fastrotate #f)<br>
</tt><p>

<head>XaoS gallery</head>

I plan to make a gallery of animations and position files on the XaoS home-page,
so please send any nice animations and images you created using XaoS
to the <a support>mailing list</a> or upload them to our website.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%drivers

<head>Platform-specific documentation</head>
XaoS is portable and works on many different platforms. Since not all platforms are
exactly the same, there are some differences between the behavior of XaoS on
different platforms. Here is documentation about each specific port.
<notex>
<center>
<p>
<a X11>X11 driver</a>
<p>
<a cocoa>Mac OS X driver</a>
<p>
<a win32>Win32 driver</a>
<p>
<a dX-window>DirectX windowed driver</a>
<p>
<a dX-fullscreen>DirectX fullscreen driver</a>
<p>
<a aa>AA-lib driver</a>
<p>
<a dos>MS-DOS driver</a>
<p>
<a ggi>GGI driver</a>
<p>
<a plan9>plan9 driver</a>
<p>
<a SVGAlib>SVGAlib driver</a>
<p>
<a DGA>DGA driver</a>
<p>
<a BeOS>BeOS drivers (BeOS, DirectWindow, WindowScreen) </a>
</center>
</notex>

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%cocoa

<head>Mac OS X port</head>
XaoS has full support for Mac OS X including native menus, dialogs, help,
Finder integration, drag and drop, and basic AppleScript support. 
<p>
The Mac OS X port of XaoS strives to provide a Mac-like experience, while
retaining compatibility with other platforms.  Some Mac-specific details
are outlined below.

<head>Zooming</head>
Since most Macs have one button mice, the middle and right buttons are emulated
with modifier keys. This means there are multiple ways to perform basic zooming 
operations:

<dl>
<dt>Zoom in
<dd>Hold down the main mouse button.
<dt>Zoom out
<dd>1. Hold down the Ctrl key while pressing the main mouse button.<br>
	2. Use the right mouse button if you have one.<br>
	3. On laptops with gestures enabled, place two fingers on your trackpad and press the main mouse button.
<dt>Pan
<dd>1. Hold down the Shift key while dragging with the main mouse button.<br>
	2. Drag with the center button if you have one.<br>
	3. Use the scroll wheel or ball if you have one to pan up/down and left/right.<br>
	4. On laptops with gestures enabled, swipe two fingers across the trackpad to pan horizontally or vertically.
</dl>

<head>Keyboard Shortcuts</head>
XaoS menu functions have been mapped to commonly used Mac keyboard shortcuts.  For example,
Open is Cmd-O and Undo is Cmd-Z, just as you would expect.

<p>However, XaoS also has its own 
long-standing tradition of cross-platform keyboard shortcuts.  These keyboard shortcuts are 
also displayed in the menus inside parentheses.  For example, the menu item "Autopilot (a)" 
means that you can press a (with no modifier keys) to activate Autopilot.  All of these 
traditional XaoS shortcuts do not use modifier keys, so they do not conflict with any standard 
Mac OS X shortcuts.

<p>In some cases, the same function may be performed with both a traditional
XaoS shortcut and a Mac OS X-specific shortcut.  You can choose whichever one is more 
comfortable for you.

<head>Full Screen Mode</head>
The Mac OS X port supports a full screen mode.  To enter it, select <emph>Mac OS X Full Screen Driver</emph>
from the <emph>UI -> Driver</emph> submenu.  Once you enter full screen mode, the menu bar will
automatically hide.  To access the menu bar, move your mouse to the top of the screen and the menu
bar will slide into view.  When you move your mouse away, it will automatically disappear again.
To return to windowed mode, select <emph>Mac OS X Windowed Driver</emph>
from the <emph>UI -> Driver</emph> submenu.

<head>Videator Support</head>
XaoS for Mac OS X can send a live video stream to Stone Design's Videator (<tt>http://stone.com/Videator/</tt>),
which can then do post-processing using Mac OS X's core video technology. This combination creates mind-blowing visuals
that are great for VJing (live video performance art).
<p>To turn on output to Videator, select <emph>Videator Output</emph> from the <emph>UI</emph> menu.
See <tt>http://stone.com/Videator/VJ.html</tt> for more details on how using Videator with XaoS.

<head>Known Issues</head>
<dl>
<dt>Catseye fractal does not render properly.
<dd>Workaround: Set the bailout to just over 4 (e.g., 4.000000001). After changing this setting, the fractal renders as expected.
</dl>
<p>
The Mac OS X driver was written by J.B. Langston, 2006-2008.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%aa

<head>AA-lib driver</head>

The AA driver is currently the most advanced and portable driver for XaoS.
It is based on AAlib--a high quality ASCII-art library developed by the AA-project.
(see <tt>http://aa-project.sf.net</tt>)
<p>
It is a fully featured XaoS driver for text mode displays. It supports 256 colors
and the mouse where possible.
<p>
It also has some extended features available from the UI menu:
<p>
<dl>
<dt>Attributes
<dd>AA-lib may use character attributes to improve image quality.
  By default it uses normal, dim and bold characters where possible,
  but you can also enable different attributes like reversed or bold font 
  characters. You may also enable usage of non ansii/reversed characters if
  your device supports it.
<dt>Font
<dd>AA-lib uses a bitmap image of the font to prepare the approximation table
used for ASCII art rendering. This bitmap is expected to be same as the one used
by your device. AAlib performs detection where possible however some devices
(like UNIX text terminals or MDA) do not support this. AAlib has few font
images compiled in, so in this case you should try to use one of them to
achieve best results.
<dt>Inversion
<dd>Some devices use inverse video: use this to get correct results on such devices.
<dt>Dithering mode
<dd>Dithering is an way to get more exact color in approximations, by combining 
  more characters; but this method can produce ugly looking noise on certain images.
  Use this menu to disable or tune it.
<dt>Palette options
<dd>By default AA driver uses the XaoS palette to render images, but it quite often
looks ugly on text displays. Here you can choose a special text palette instead. Note that with 
filters enabled, the results may be rather ugly. This function is available from
the <emph>palette menu</emph>.
<dt>Save text screen
<dd>The normal save function will generate a PNG image instead of nice
  ASCII-art. To save ASCII art use this function instead. It supports many  
  text file formats like HTML, ANSI, more, etc... It will also ask you for
font and attributes(see above). It is available from the <emph>file
menu</emph>.
</dl>
<p>
The AA-lib driver also provides the full set of standard AA-lib's command line
options. You may use them to tune parameters like gamma correction, and so on.
See <tt>xaos -help</tt> or the AA-lib documentation for details.
<p>
The AA driver was written by Jan Hubicka, 1997.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%dos

<head>DOS driver</head>
This is a fully featured driver for DJGPP and allegro. 
It supports many VGA modes, VESA 1.0--3.0, VBE/AF, S3 and some other cards.
<p>
The following problems may occur:
<p>
<dl>
<dt>Some DPMI servers may cause problems
<dd>Some DPMI servers like the one from Novell/Dr/Open DOS are buggy. Use clean DOS
  instead and XaoS will automatically start <tt>cwsdpmi</tt>.
  Under Open Dr DOS use <tt>dpmi off</tt> at command line to disable it.
<dt>Higher resolutions don't work
 <dd>If your videocard has enough memory for the selected resolution,
 you most probably have an unsupported videocard.
 Please use a VESA BIOS extension on this videocard. (See the note about VESA
 at the end of this section.)
<dt>XaoS needs a coprocessor
 <dd>I don't distribute a coprocessor library linked into XaoS because it is too slow for
 a real-time zoomer. Coprocessor emulation will not help, because xaos works in protected mode.
<dt>XaoS needs mouse driver to be usable
<dt>XaoS works slowly in higher resolution
 <dd>This could also be caused by Allegro's slow driver or your videocard's VESA BIOS.
 You could try some other VESA BIOS extension instead.
 Look at the <tt>http://www.talula.demon.co.uk</tt> for the FreeBE
 project or Scitech Display Doctor package.
 (See the note about VESA at the end of this section.)
</dl>
<head>VESA</head>
VESA is a standard for using higher resolutions in DOS. Many videocards have
VESA support in the BIOS so you don't need any additional software, while others
need support from a special program. Also some VESA BIOS implementations are
buggy or suboptimal; there are 3 different versions, version 1.0 is many times
slower than 2.0, which has support for protected mode and linear framebuffers.
So if you have problems with higher resolutions, or some graphics modes are
not available (like 320x200 truecolor), you might try some software package
which emulates VESA.
<p>
The most famous VESA emulating program is Scitech Display Doctor. It has support
for many videocards and is quite reliable. It's disadvantage is that it is
shareware and works for only 30 days. You might also look on
<tt>ftp.simtel.net</tt>, where there are many VESA emulation packages such as
<tt>s3vbe</tt> or the new FreeBe project at
<tt>http://www.talula.demon.co.uk</tt>
<p>
DOS driver was written by Jan Hubicka, 1997.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%ggi

<head>GGI driver</head>

GGI stands for General Graphics Interface. Part of this project is to develop
libggi, a portable graphics library, and XaoS's GGI driver uses that.
It is experimental, since the API of libggi is not stabilized yet.
There are some problems with keyboard handling--the shift key doesn't work
yet.
<p>
Everything else might work well, but there are no guarantees. It is alpha quality
software.
<p>
GGI driver was written by Jan Hubicka, 1998.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%plan9

<head>Plan9 driver</head>

Plan9 is a very nice small operating system by the authors of Unix at Bell Labs.
It is very incompatible with other operating systems; even the C compiler and
header files are different, but XaoS should work well there (even on the
limited free demo installation without any POSIX compatibility stuff)
<p>
There are a few limitations: the file selector and image saving don't work.
You can save position files and then later render them on the other OS, or save
screenshots.
<p>
Plan9 terminals also don't provide any way to catch the arrow keys, so you
can't use them. Use the mouse to navigate in the menus. Also, getting the screen
resolution is impossible, so use <tt>-pixelwidth</tt> and <tt>-pixelheight</tt>
instead of <tt>-screenwidth</tt> and <tt>-screenheight</tt>.
<p>
By default XaoS changes the colormap. This will collide with other colorful
programs like Mortha. You can disable this behavior using
<tt>-nopalette</tt> switch, but this will slow down XaoS.
<p>
Plan9 driver was written by Jan Hubicka, 1997.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%SVGAlib

<head>SVGAlib driver</head>

This is a driver for Linux SVGAlib. I really like this driver, because
I much prefer full screen zooming instead of a small 320x320 window in X11.
It was one of the first drivers for XaoS and is fully featured. 
The following problems can occur:
<p>
<dl>
<dt>XaoS doesn't initialize graphics mode
<dd>when started under users other than root SVGAlib requires root privileges
  to directly access the hardware. When you really want to start XaoS as a
  normal user, enable the suid bit (<tt>chmod +s</tt>) at XaoS executable.
  note that I take care to disable all security holes caused by this
  bit so I believe it is safe.
<dt>Mouse doesn't work
<dt>Screen is blank at higher resolutions
<dd>Both this problems are probably caused by misconfiguration of 
SVGAlib. Please configure it in <tt>etc/vga/libvga.cong</tt> or 
<tt>/usr/local/lib/libvga.conf</tt>
GPM can also cause problems. Try to kill it before starting XaoS.
<dt>When I switch console I can't switch back
<dd>This is another typical SVGAlib bug. Try to hold <tt>F</tt> key longer than <tt>alt</tt>.
  It helps on my computer. On older SVGAlib there was a famous ``enter bug'' that caused
  a crash after pressing enter. Try to update to a newer release.
</dl>
<p>
SVGAlib driver was written by Jan Hubicka, 1997.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%win32

<head>Win32 driver</head>

This is a driver for Windows 9x and NT. It is new since version 3.1 and
because of some oddities of Windows API it may be rather unstable.
Please report all bugs. In case of problems you could use the DOS version
of XaoS instead.
<p>
The driver should work in all bit depths, but 16 color mode is not natively
supported by the XaoS engine. XaoS internally works in 32k colors and
the result is converted to 16 colors by Windows. Because Windows
conversion routines are slow and ugly, the result is slow and ugly.
Please configure your display to another bit depth to ``solve''
this problem.
<p>
Use <tt>-size WIDTHxHEIGHT</tt> command line option to change the default
window size.
<p>
This driver also maps to native Windows look and feel. There is a small
problem with combo boxes in dialogs. They are expected to give you a choice
between a few strings. The keyboard controls (changing choice by arrow keys)
work, but mouse selection is broken. If you know how to solve this bug,
please let me know.
<p>
XaoS is a UNIX application and has many command line options. 
Some features are not available from the GUI.
Because Windows applications can't have normal output,
most of the critical messages are displayed in message boxes, but
some longer messages are omitted. The most significant omission is the help
about command line options that you can find in <tt>doc/cmdopts.txt</tt>.
<p>
One thing that might be confusing is that animation rendering mode doesn't
display anything, but only renders images. Start the rendering,
and a message box will inform you that XaoS is entering the calculation
loop. Relax and wait for the message box signaling the end of the loop.
<p>
Note that XaoS also supports the <a dX-window>DirectX</a> API.
<p>
Win32 driver was written by Jan Hubicka, Jan Olderdissen and Pavel Tzekov, 1999.


%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%dX-window

<head>DirectX windowed driver</head>

This is a driver for Windows 9x and NT. It is new since version 3.1 and
because of some oddities of Windows API and kludges in DirectX
it may be rather unstable.  Please report all bugs. In case
of problems you could use the DOS version of XaoS instead.
<p>
The DirectX driver is an alternative to the windowed <a win32>win32 driver</a>.
If you have DirectX installed, this driver is used by default. It has
almost the same behaviour as the <a win32>win32 driver</a> so please read its
documentation for more details. The only difference should be the display
speed.
<p>
The driver supports only hicolor and truecolor modes. There is no support
for 256 and 16 color modes because of palette collision problems. The win32
driver will be used in these cases by default, so this should cause no
problems.
<p>
If you are experiencing problems with this driver, you might want to
use the <a win32>win32 driver</a> by default; to do this, use the <tt>-driver win32</tt>
command line option.
<p>
DirectX driver was written by Jan Hubicka, Jan Olderdissen
and Pavel Tzekov, 1999.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%dX-fullscreen

<head>DirectX fullscreen driver</head>
This is da river for Windows 9x and NT. It is new since version 3.1 and
because of some oddities of Windows API and kludges in DirectX
it may be rather unstable.  Please report all bugs. In case
of problems you could use the DOS version of XaoS instead.
<p>
This driver allows the Windows port of XaoS to run in full screen mode.
The driver supports 256, 65536 and 16777216 color modes (24bpp and 32bpp)
in all resolutions supported by DirectX.
You can change graphics mode by pressing the <tt>=</tt> key
(or by using the UI/Resize menu). If the selected mode is not supported,
the driver will restore the previous setting.
<p>
Use the <tt>-mode WIDTHxHEIGHTxDEPTH</tt> (like <tt>-mode 640x480x16</tt>)
command line option to change graphics mode.
<p>
If you want to start XaoS in DirectX, use the <tt>-driver dX-fullscreen</tt>
option.
<p>
See the <a win32>Win32 driver</a> documentation for some more Windows
releated information.
<p>
DirectX driver was written by Jan Hubicka, Jan Olderdissen
and Pavel Tzekov, 1999.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%BeOS DirectWindow WindowScreen

<head>BeOS support</head>

XaoS has pretty advanced support for BeOS R4. It works on both PowerPC and
Intel platforms, supports multithreading, the clipboard, file dragging,
has native look and feel and can work as an image translator from XaoS files
to images.
<p>
The first version of the BeOS driver was written by Jens Kilian and later
extended by Jan Hubicka.
<p>
<head>Installation</head>
<p>
You can start the installation script to do everything for you. If you want
something special, read this section.
<p>
In order for XaoS to work you need to keep the executable together with
its data files (<tt>help</tt>, <tt>examples</tt>, <tt>catalogs</tt> and the <tt>tutorials</tt> directory)
<p>
When first started, XaoS registers two new mime types called
<tt>image/x-xaos-position</tt> for XaoS Position Files and
<tt>video/x-xaos-animation</tt> for XaoS Animation Files,
registers icons for them and sets itself as default application.
<p>
<head>Available display drivers</head>
<p>
XaoS supports following drivers:
<p>
<dl>
<dt>BeOS
<dd>Standard windowed driver using application server
<dt>DirectWindow
<dd>Driver done using Game Kit's direct window class
<dt>WindowScreen
<dd>Fullscreen driver.
</dl>
<p>
By default, XaoS starts in windowed mode and uses the application server for output.
You could change the driver to DirectWindow to use direct access to video RAM.
Note that this mode is slower in most cases, and not supported by some videocards.
<p>
The BeOS driver by default chooses the most similar bitmap supported by XaoS
to achieve best and fastest results.
In the UI menu you can change this default choice to another one if you wish.
Also you can ask the BeOS and DirectWindow to resize to fullscreen mode.
<p>
XaoS also supports real fullscreen mode using the BWindowScreen API. To switch
XaoS to this driver, use the UI menu. If you want to use this mode by default,
use the <tt>-driver WindowScreen</tt> command line option.
<p>
This driver differs a lot from windowed ones. It use direct access to the video
card, allowing you to change video mode. Also, the 256 color mode
can access the palette, so it is not dithered like the windowed mode.
Because BeOS can't do GUI in fullscreen mode, XaoS uses its own toolkit.
I hope you will feel confortable in it.
<p>
<head>XaoS as translator</head>
<p>
You should be able to open XaoS files in graphics applications
such as ShowImage or ArtPaing. In Preferences you can find the DataTranslations
program, that can be used to set the size, type and DPI of the resulting image.
Also antialiasing can be enabled.
<p>
Note that <emph>translation can take a while</emph>. So be patient and
wait for the result.
<p>
If the translator doesn't work, ensure that you have a link to the XaoS executable
in <tt>/boot/beos/system/add-ons/Translators/</tt>. 

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%X11

<head>X11 driver</head>
This was the first driver done for XaoS. It supports many visuals, shared
colormaps and MitSHM extension.
<p>
Bugs/limitations:
<p>
<dl>
<dt>XaoS makes some X servers too busy
<dd>Sometimes XaoS generates images faster than X can display them.
In this case XaoS responds poorly to the mouse, and other applications slow
down too. This happens especially often on old R4 servers. Use <tt>-sync</tt>
to avoid this problem. Note that <tt>-sync</tt> does <tt>not</tt> make all
communication with X asynchronous; it just adds one additional XSync call.
So the slowdown is not as large as you might expect.
<dt>Does not work on all visuals
<dd>This driver supports only 8bpp pseudocolor/grayscales, 15,16,24 and 32bpp truecolor, 1bpp and 8bpp staticolor visuals.
<dt>Palette rotating does not work for 8bpp pseudocolor w/o private palette
</dl>
<p>
X11 driver was written by Jan Hubicka and Thomas Marsh, 1997.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%DGA

<head>DGA driver</head>
This is the driver for DGA (Direct Graphics Architecture) extension used by
XFree86 X servers. It is pretty new so it could be buggy.
<p>
Bugs/limitations:
<p>
<dl>
<dt>In 8bpp mode, XaoS has problems with the palette with certain window managers
<dd>I don't know why this happens. Just let me know what's wrong, or use another
window manager.
<dt>Banked modes are not supported.
<dd>I don't have any card to test this with, so it doesn't work in the current version.
</dl>
<p>
DGA driver was written by Jan Hubicka, 1999.


%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%tutorial

<head>XaoS tutorial</head>

This is a brief introduction to the basic XaoS features.

<head>How to zoom</head>
 The main advantage of XaoS is that after a few seconds' delay to calculate
 the first image, you may choose any point with the mouse and press the <emph>left</emph> button.
 The image will start to zoom smoothly into the point you choose. You may move
 the mouse and zoom smoothly into interesting areas. By pressing the <emph>middle
 button</emph> (or <emph>left+right</emph> buttons) you may also
 <emph>move the image</emph> using ``drag & drop'' if you missed an interesting
 place. <emph>Unzooming</emph> is also possible by using the <emph>right button</emph>,
 but it is much slower because optimizations are not so effective as for zooming.
<p>
 In case you think that the default <emph>speed</emph> is boring (it is quite slow, to
 make XaoS smooth on a slow computer) you may change it by pressing <emph>arrow
 up/down</emph>. But faster zooming is more expensive, so if the speed is too high
 you will see little but funny colorful blinking rectangles.
 
<head>Autopilot</head>

 To make XaoS yet more impressive we made a special autopilot that
 automatically drives into interesting boundaries of the set. So you can
 press <tt>A</tt>, play your favorite music, drink coffee and relax. I never
 tried this but it should be really relaxing! Many pictures in the XaoS
 gallery were discovered using the autopilot.
<p>
 The autopilot also has some additional features. It turns back when the
 zoomed picture stops being interesting, and is able to spot when it's zoomed
 into a really boring part (or has reached the limit of floating point
 numbers) and restart zooming from the top.
<p>
<head>Various fractal formulae</head>

 XaoS also supports formulae other than the Mandelbrot set. You may change
 <emph>formula</emph> using the <emph>number keys</emph> 
 or <emph>SHIFT+letters</emph>.


<p>
 On keys <tt>1</tt> to <tt>5</tt> are <emph>Mandelbrot sets of various power</emph>. The ``normal''
 Mandelbrot set is on key <tt>1</tt>. 
<p>
 On key <tt>6</tt> is a fractal called <emph>Newton</emph>. It is Newton's famous formula for finding roots.
<p> 
 On key <tt>7</tt> is the <emph>fourth ordered Newton</emph> fractal.
<p>
 On key <tt>8</tt> is a fractal called <emph>Barnsley</emph>.
<p>
 On key <tt>9</tt> is <emph>Barnsley's second</emph> fractal.
<p>
 On key <tt>0</tt> is <emph>Barnsley's third</emph> fractal.
<p>
 With keys <tt>SHIFT-A</tt> you can display a fractal called <emph>octo</emph>. It is a fractal that Thomas
 discovered in fractint.
<p>
 With keys <tt>SHIFT-B</tt> you can display a fractal called <emph>Phoenix</emph>. It is a very nice and quite famous fractal.
<p>
 With keys <tt>SHIFT-C</tt> you can display a fractal called <emph>Magnet</emph>. This fractal has quite a complex formula so it is
 a bit slow. 
<p>
 With keys <tt>SHIFT-D</tt> you can display the <emph>Magnet2</emph> fractal.
<p>
 The rest of the built-in fractals are accessible through an other menu, but 
 you can still use the hotkeys.
<p>
 On <tt>SHIFT-E</tt> is a fractal called <emph>Triceratops</emph> found by Arpad.
<p>
 On <tt>SHIFT-F</tt> is a fractal called <emph>Catseye</emph> found by Arpad.
 This is more interesting if you change the bailout value.
<p>
 On <tt>SHIFT-G</tt> is a fractal called <emph>Mandelbar</emph>. It was in
 Gnofract4d, and they found it at:
 http://mathworld.wolfram.com/MandelbarSet.html
<p>
 On <tt>SHIFT-H</tt> is the <emph>Lambda</emph> fractal.
<p>
 On <tt>SHIFT-I</tt> and <tt>SHIFT-J</tt> are the <emph>Manowar</emph> 
 and <emph>Spider</emph> fractals, they were found by users of fractint. 
 (Scott Taylor or Lee Skinner)
 It was on http://spanky.triumf.ca/www/fractint/
 taylor_skinner_type.html
<p>
 The next 3 fractals are famous classic fractals.
<p>
 On <tt>SHIFT-K</tt> is the <emph>Sierpinski</emph> Gasket.
 You can change its shape by selecting another Julia seed. 
 (This is for technical reasons.)
<p>
 On <tt>SHIFT-L</tt> is the <emph>Sierpinski Carpet.</emph>
 It's shape can also be changed by selecting another Julia seed.
<p>
 On <tt>SHIFT-M</tt> is the <emph>Koch Snowflake.</emph>
<p>
 

<head>Out-coloring modes</head>

 To make fractals yet more interesting, more coloring modes for points
 outside the set are provided. ``Classical coloring mode'' uses the number of
 iterations that the orbit required to escape to (nearly) infinity. You can change this
 mode from the <emph>Fractal menu</emph> or by pressing key <tt>C</tt>
 To see more about coloring modes, try the tutorial on <tutor incolor.xaf>Incoloring modes</tutor> from the XaoS features overview.
<p>
 Those cryptic names for coloring modes are mathematical formulae, where <emph>iter</emph> means number
 of iterations, <emph>real</emph> means real coordinate of last orbit, and <emph>imag</emph> means imaginary
 coordinate of last orbit.
<p>
<head>In-coloring mode</head>

 In-coloring mode is similar to out-coloring, except that it changes how
 things inside the set are displayed. This can also be changed from the <emph>fractal
 menu</emph> or by pressing <tt>F</tt>. 
 <p>
 You might also want to see the tutorial on
 <tutor outcolor.xaf>Out-coloring modes</tutor> from the XaoS features overview.

<head>Planes</head>

 All fractals displayed by XaoS are functions with a complex parameter. It
 can be displayed in the normal complex plane, where x is the real part of
 the number, and y is the imaginary part; but it can also be displayed in
 a number of other planes. You can select the plane to use from the
 <emph>Fractal menu</emph>, or by pressing <tt>I</tt>.
<p>
 Like the coloring modes, planes have cryptic names. You guessed it, they're
 mathematical formulae. Here <tt>mu</tt> means coordinates in the normal
 complex plane. If you have coordinates in <tt>1/mu</tt> plane, and you need
 coordinates in the a complex plane (to calculate the Mandelbrot set) you
 simply use the coordinates as mu. Lambda is another plane that can be
 converted to mu using a similar formula.
 <p>
<dl>
 <dt>mu
	<dd>normal mode.

 <dt>1/mu
	<dd>Inversion: infinity goes to 0 and 0 goes to infinity.

 <dt>1/(mu+0.25)
	<dd>Similar to inversion, but moves the center outside of the
        Mandelbrot set so that it looks parabolic.

 <dt>lambda
	<dd>Lambda plane.

 <dt>1/lambda
	<dd>Inversion of lambda plane.

 <dt>1/lambda-1
	<dd>Inversion with moved center.

 <dt>1/(mu-1.40115)
	<dd>A very interesting mode for the Mandelbrot set. It makes small things
	big, so you can browse the set's details easily.
</dl>
<p>
 
<head>Mandelbrot/Julia switching</head>

 Most of the fractals displayed by XaoS (currently all of them) have two
 forms: Mandelbrot and Julia. Every point in a Mandelbrot set has its
 own Julia set. To see more about this correspondence, try the tutorial on
 <tutor julia.xaf>Julia set</tutor> from the Introduction to fractals.
<p>
 In the Mandelbrot mode, you can get a corresponding Julia by moving the mouse
 to an interesting point and pressing <tt>M</tt>. To get back press <tt>M</tt>
 again. Some fractals (Barnsley and phoenix) are already in their Julia
 versions, because the Mandelbrot ones are boring. But by pressing <tt>M</tt>
 in such fractal you should get the Mandelbrot version, and by choosing another
 point as the base point and pressing <tt>M</tt> again you should get a
 completely different fractal. The most interesting points for Julia sets
 are at the boundaries of the Mandelbrot set. Most of the Julias inside or
 outside the set are boring.
<p>
 
<head>Fast Julia preview mode</head>

 Fast Julia mode is a quick way to find a point to use as a base for the Julia
 set.. Just press <tt>J</tt> and a small Julia set will be displayed in the top
 left corner. Then move the mouse around with button 1 depressed, and the Julia
 for the point the mouse is over will be automatically generated. 
 
<head>Palette</head>

 If you think that the default XaoS colors are ugly or you are just
 bored by them you can change it by pressing <tt>P</tt>. XaoS will
 automatically generate random palettes. Many of them look ugly, so
 press <tt>P</tt> again to get another one until you find one you like.
<p>
<head>Filters</head>

 Many interesting effects are done by post-calculation <a filter>filters</a>.
 XaoS has filters that do everything from embossing, through motion-blurring,
 right through to turning the fractal into a stereogram. To enable them use
 the <tt>filter menu</tt> or press <tt>E</tt>.
<p>
<head>Palette cycling</head>

 This is a very old trick that makes the Mandelbrot set a little flashier. You
 may enable or disable it using <tt>Y</tt>. In the truecolor modes you need
 to enable the <a palettef>palette emulator filter</a> first. This is done
 via the <tt>E</tt> key, or from the filter menu.
<p>
<head>Changing number of iterations</head>

 To calculate fractals perfectly, you need an infinite number of
 iterations. XaoS does just the first few of them, so after lots of zooming
 you may get into a place that looks quite boring, and the boundaries of the
 set are rounded, without any interesting details. This can be changed by
 changing the number of iterations:
 <p>
 Press and hold <tt>arrow right</tt> and wait until iterations are high enough.
 This may slow down calculation much. To reduce number of iterations
 press <tt>arrow left</tt>.
 
<head>Changing resolution</head>

 XaoS usually starts in a low resolution (320x200 or thereabouts) to make
 calculations faster. If you have a fast computer or you need to
 save bigger <tt>.gif</tt> images, you may change the resolution. This
 can be done by pressing <tt>=</tt> in the full screen drivers, or simply
 by resizing the XaoS window.

<head>Changing driver</head>

 XaoS usually has more than one driver available. You may change it on
 the fly in case you want a different one. For example, XaoS started in X11
 can be switched at runtime to use the AA driver. This can be done from the
 UI menu.
 <p>
 This action is bit dangerous, because XaoS can crash during initialization
 if there is some problem with initialization; XaoS tries to initialize a new
 driver, and if it fails it attempts to return back to the original. Sometimes
 this is impossible, and all XaoS can do is terminate..

<head>Other features</head>
XaoS has many other features, but they don't fit into this tutorial. Most of
them are available from the menu, so you can experiment with them. You might
also want to see the <emph>animated tutorials</emph> from the <emph>help menu</emph>,
to have an idea what XaoS can do.


%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%menus
<main><head>Menus, functions and command line parameters</head></main>
All XaoS functions are referenced by a central function registry. The
scripting language, menus, dialogs and command line options are built
from this database. This section contains information about all functions
available in this registry.
<menuitems><center>
<p><submenu><a root>Root menu</a>
<p><submenu><a animroot>Animation root menu</a>
<p><submenu><a plc>Replay only commands</a>
%end
<p><submenu><a linemenu>Line drawing functions</a>
<p><submenu><a animf>Animation functions</a>
<p><submenu><a time>Timing functions</a>
<p><submenu><a file>File</a>
<p><submenu><a edit>Edit</a>
<p><submenu><a fractal>Fractal</a>
<p><submenu><a calc>Calculation</a>
<p><submenu><a mfilter>Filters</a>
<p><submenu><a ui>UI</a>
<p><submenu><a misc>Misc</a>
<p><submenu><a helpmenu>Help</a>
<p><submenu><a xtextpos>Horizontal text position</a>
<p><submenu><a ytextpos>Vertical text position</a>
<p><submenu><a mformula>Formulae</a>
<p><submenu><a palettemenu>Palette</a>
</center></menuitems>
<node root, , animroot, menus>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%root

<notex>
<menuhead><head>Root menu</head></menuhead>
This menu is usually displayed at the top of the screen or window. It contains all
currently available submenus. During animation another menu is displayed--the
<a animroot>Animation root menu</a>.
<menuitems><center>
<p><submenu><a file>File</a>
<p><submenu><a fractal>Fractal</a>
<p><submenu><a calc>Calculation</a>
<p><submenu><a mfilter>Filters</a>
<p><submenu><a ui>UI</a>
<p><submenu><a misc>Misc</a>
<p><submenu><a helpmenu>Help</a>
</center></menuitems>
</notex>
<node animroot, root, plc, menus>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%animroot

<menuhead><head>Animation root menu</head></menuhead>
This menu is displayed at the top of the screen when animation replay is active.
<menuitems><center>
<p><submenu><a file>File</a>
<p><a stopreplay>Stop replay</a>
<p><submenu><a helpmenu>Help</a>
<p><submenu><a ui>UI</a>
</center></menuitems>
<node stopreplay, , , animroot>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%stopreplay
<head>Stop replay</head>
Terminate animation replay.
<p>
<emph>Available as</emph>: menu item



<node plc, animroot, linemenu, menus>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%plc
<menuhead><head>Replay only commands</head></menuhead>
Some commands, such as timing primitives or animation functions, are available
only in animation files.
<menuitems><center>
<p><submenu><a linemenu>Line drawing functions</a>
<p><submenu><a animf>Animation functions</a>
<p><submenu><a time>Timing functions</a>
<p><a load>Include file</a>
</center></menuitems>
<node load, , , plc>


%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%load
<head>Include file</head>
<p><emph>Syntax</emph>:(load file)
<p>
This function lets you include another file in your script. It works similarly
to <tt>#include</tt> in C or <tt>load</tt> in Scheme.
The file is searched for in the same directory as the current source file.
<p>
<emph>Available as</emph>: command

<node linemenu, plc, animf, menus>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%linemenu

<menuhead><head>Line drawing functions</head></menuhead>
XaoS has support for drawing lines. These functions are available only in
animations and could be used to show some parts of fractals or draw simple
diagrams. See the tutorial ``<tutor intro.xaf>Introduction to fractals</tutor>''
for examples of this feature.
<p>
Lines can be drawn in <emph>screen</emph> coordinates, where 0,0
is the top left corner and 1,1 is bottom right, <emph>scaled</emph>
coordinates, which are similar, but scaled to keep 0,0--1,1 rectangular,
or <emph>Fractal</emph> coordinates, to draw a line at an exact position
on the screen.
<p>
The color of the line should be specified by the <a color><tt>color</tt></a> command.
You might draw an arbitrary number of lines and, later, morph them. Each line is
identified by a unique numeric key; the current key can be set using <tt>linekey</tt>.
Commands for changing lines operate on the line with the current key.
(Lines drawn in sequence have consecutive numbers.)
<p>
For example:
<p><tt>
(color 'red)<br>
(line 'scaled 0.3 0.5 0.7 0.5)<br>
(line 'scaled 0.3 0.5 0.7 0.5)<br>
(line 'scaled 0.3 0.5 0.3 0.5)<br>
(line 'scaled 0.7 0.5 0.7 0.5)<br>
(linekey 0)<br>
(morphline 'scaled 0.3 0.3 0.7 0.3)<br>
(morphline 'scaled 0.3 0.7 0.7 0.7)<br>
(morphline 'scaled 0.3 0.3 0.3 0.7)<br>
(morphline 'scaled 0.7 0.3 0.7 0.7)<br>
(usleep 1000000)<br>
</tt><p>
Creates line morphing to rectangle.
<notex>
<menuitems><center>
<p><a line>Draw line</a>
<p><a morphline>Morph line</a>
<p><a morphlastline>Morph last line</a>
<p><a linekey>Set line key</a>
<p><a clearline>Clear line</a>
<p><a clearlines>Clear all lines</a>
</center></menuitems>
</notex>
<notex>
<node line, , morphline, linemenu>
</notex>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%line


<notex>
<head>Draw line</head>
</notex>
<p><emph>Syntax</emph>:(line keyword complex complex)
<p>
Draw line between two points.
<tt>keyword</tt> specifies type of coordinates and should be one of the
following: <tt>`fractal</tt>, <tt>`screen</tt> or <tt>`scaled</tt>.
This function also increases the line key.
<p>
<emph>Available as</emph>: command

<notex>
<node morphline, line, morphlastline, linemenu>
</notex>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%morphline


<notex>
<head>Morph line</head>
</notex>
<p><emph>Syntax</emph>:(morphline keyword complex complex)
<p>
Morph current line to given coordinates.
<tt>keyword</tt> specifies type of coordinates and should be one of the
following: <tt>`fractal</tt>, <tt>`screen</tt> or <tt>`scaled</tt>.
The line will start moving at the next <a time>timing command</a>, and reach the
final position before the end of it.
This function also increases the line key.
<p>
<emph>Available as</emph>: command

<notex>
<node morphlastline, morphline, linekey, linemenu>
</notex>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%morphlastline


<notex>
<head>Morph last line</head>
</notex>
<p><emph>Syntax</emph>:(morphlastline keyword complex complex)
<p>
This function has the same functionality as <a morphline>morphline</a>, but it doesn't
increase the line key, and touches the line with the previous key. This is useful when
you want to move a just-drawn line--you don't need to set <a linekey>linekey</a> back.
<p>
<emph>Available as</emph>: command

<notex>
<node linekey, morphlastline, clearline, linemenu>
</notex>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%linekey
<notex>
<head>Set line key</head>
</notex>
<p><emph>Syntax</emph>:(linekey integer)
<p>
Set current line key.
<p>
<emph>Available as</emph>: command

<notex>
<node clearline, linekey, clearlines, linemenu>
</notex>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%clearline
<notex>
<head>Clear line</head>
</notex>
<p><emph>Syntax</emph>:(clearline)
<p>
Clear current line. This function also increases the line key.
<p>
<emph>Available as</emph>: command

<notex>
<node clearlines, clearline, , linemenu>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%clearlines
<head>Clear all lines</head>
</notex>
<p><emph>Syntax</emph>:(clearlines)
<p>
Clear all displayed lines. Lines can also be cleared using the
<tt>clearscreen</tt> or <tt>display</tt> commands available from the <a misc>Misc menu</a>.
<p>
<emph>Available as</emph>: command

<node animf, linemenu, time, menus>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%animf

<menuhead><head>Animation functions</head></menuhead>
These functions are used to animate fractal state--to zoom, unzoom and morph
various parameters. They should be used only in animation files.
Animations are usually performed for a time selected by an immediately following
<a time>timing function</a>.
For example:
<p><tt>
(view 0 0 1 1)<br>
(morphview 0 0 2 2)<br>
(usleep 5000000)
</tt><p>
Will do a 5 second long unzooming animation.
<menuitems><center>
<p><a animateview>Animate view</a>
<p><a smoothmorph>Smooth morphing</a>
<p><a morphview>Morph view</a>
<p><a morphjulia>Morph julia</a>
<p><a moveview>Move view</a>
<p><a morphangle>Morph angle</a>
<p><a zoom>Zooming functions</a>
</center></menuitems>
<node animateview, , smoothmorph, animf>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%animateview
<head>Animate view</head>
<p><emph>Syntax</emph>:(animateview float float float float)
<p>
This function is almost identical to function <a uiview><tt>view</tt></a>.
It expects that the view will be changed only slightly, so recalculation is done
with <tt>ANIMATE</tt> priority. This means that dynamic resolution is used by
default.
<p>
Viewport is selected by the center and two radiuses (real and imaginary). See
<a uiview><tt>view</tt></a> for more information.
<p>
<emph>Available as</emph>: command

<node smoothmorph, animateview, morphview, animf>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%smoothmorph
<head>Smooth Morphing</head>
<p><emph>Syntax</emph>:(morphview keystring starttime endtime)
This function lets you smoothly start and stop morphing. Specify
starttime and stoptime as nonzero, and morphing will speed up and slow down for
that number of usecs.
<p>
The keystring is used to select what morphing you want to control. It is one of
the following:
<dl>
<dt>'view
<dd>control <a morphview>morphview</a>
<dt>'angle
<dd>control <a morphangle>morphangle</a>
<dt>'julia
<dd>control <a morphjulia>morphjulia</a>
<dt>'line
<dd>control <a morphline>morphline</a>
</dl>
<node morphview, smoothmorph, morphjulia, animf>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%morphview
<head>Morph view</head>
<p><emph>Syntax</emph>:(morphview float float float float)
For the time selected by the next <a usleep><tt>usleep</tt></a> or other timing function, the viewpoint is smoothly morphed from
the current one to that selected by <tt>morphview</tt>.
<p>
Viewport is selected by the center and two radiuses (real and imaginary). See
<a uiview><tt>view</tt></a> for more information.
<p>
This function can easily be used for creating zooming/unzooming animations using position files.
This is an example position file generated by XaoS:
<p><tt>
(initstate)<br>
(defaultpalette 0)<br>
(formula 'mandel)<br>
(view -1.64128273713 -5.50393226816E-05 9.69332308848E-08 
    9.69332308834E-08)<br>
</tt><p>
By replacing the <tt>view</tt> command with <tt>morphview</tt> and
adding <tt>usleep</tt> you can create a zooming animation:
<p><tt>
(initstate)<br>
(defaultpalette 0)<br>
(formula 'mandel)<br>
(morphview -1.64128273713 -5.50393226816E-05 9.69332308848E-08 
    9.69332308834E-08)<br>
(usleep 10000000)
</tt><p>


<emph>Available as</emph>: command

<node morphjulia, morphview, moveview, animf>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%morphjulia
<head>Morph Julia</head>
<p><emph>Syntax</emph>:(morphjulia complex)
For the time selected by the next <a usleep><tt>usleep</tt></a> or other timing function, the Julia seed
is smoothly interpolated from the current one to that selected by <tt>morphjulia</tt>. By default this will
cause recalculation of the whole screen.
To avoid this, use <a fastjulia>fast Julia mode</a>.
<p>
A simple animation morphing Julia seed in the X axis:
<p><tt>
(initstate)<br>
(fastjulia #t)<br>
(juliaseed -2 0)<br>
(morphjulia 2 0)<br>
(usleep 2000000)<br>
</tt><p>
<p>
<emph>Available as</emph>: command

<node moveview, morphjulia, morphangle, animf>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%moveview
<head>Move view</head>
<p><emph>Syntax</emph>:(moveview complex)
Smoothly move the image center to another position.
<p>
<emph>Available as</emph>: command

<node morphangle, moveview, zoom, animf>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%morphangle
<head>Morph angle</head>
<p><emph>Syntax</emph>:(morphangle float)
Smoothly rotate the image to another angle. By default rotation causes
recalculation of the whole screen. To avoid this you need to enable 
<a rotate>fast rotate mode</a>. Don't forget to disable it later, since
it slows down other animations. 
<p>A simple ``rotozooming'' animation:
<p><tt>
(initstate)<br>
(fastrotate #t)<br>
(morphview -1.64128273713 -5.50393226816E-05 9.69332308848E-08<br>
9.69332308834E-08)<br>
(morphangle 300)<br>
(usleep 10000000)<br>
(wait)<br>
(fastrotate #f)<br>
</tt><p>
<emph>Available as</emph>: command

<node zoom, morphangle, , animf>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%zoom zoom unzoom stop
<head>Zooming functions</head>
<p>
The functions for zooming/unzooming were created mainly for recording
animations. In manually created animation files, it is easier to use
<a morphview><tt>morphview</tt></a>.
<p>
<p><emph>Syntax</emph>:(zoomcenter complex)
This function sets the center to zoom in on. The center is given as a position
in fractal coordinates.
<p>
<emph>Available as</emph>: command
<p><emph>Syntax</emph>:(zoom)
Start zooming to the area specified by <tt>zoomcenter</tt>.
<p>
The speed of zooming should be controlled by the function <a speed><tt>speed</tt></a>
or in a more exact way by <tt>maxstep</tt> and <tt>speedup</tt>.
<p>
<p><emph>Syntax</emph>:(unzoom)
<p>
Start unzooming from the area specified by <tt>zoomcenter</tt>.
<p>
<emph>Available as</emph>: command
<p><emph>Syntax</emph>:(stop)
Stop zooming or unzooming.
<p>
<emph>Available as</emph>: command

<node time, animf, file, menus>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%time

<menuhead><head>Timing functions</head></menuhead>
Timing functions are used to control the animation replay daemon. It can wait
for a given time, or wait until calculation is complete. The animation functions
are controlled by such waiting; animations that are running while delays start
keep running through the delay.
<menuitems><center>
<p><a usleep>Usleep</a>
<p><a textsleep>Wait for text</a>
<p><a wait>Wait for complete image</a>
</center></menuitems>
<node usleep, , textsleep, time>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%usleep
<head>Usleep</head>
<p><emph>Syntax</emph>:(usleep integer)
<p>
This function waits for a given amount of time (in usec) before processing
the next command. The screen is recalculated and displayed at the beginning of
usleep if necessary necessary. The remaining time is spent in waiting or
performing animation.
<p>
<emph>Available as</emph>: command

<node textsleep, usleep, wait, time>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%textsleep
<head>Wait for text</head>
<p><emph>Syntax</emph>:(textsleep)
<p>This function's behavior is very similar to <a usleep><tt>usleep</tt></a>,
but the time is calculated from the number of letters currently displayed
onscreen. If you want to wait just long enough for the user to read the subtitle,
use this function. The user can alter the replay speed as desired using 
<a letterspersec><tt>letterspersec</tt></a>. This value can be changed during
replay with the arrow keys.
<p>
<emph>Available as</emph>: command

<node wait, textsleep, , time>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%wait
<head>Wait for complete image</head>
<p><emph>Syntax</emph>:(wait)
<p>
Wait until the image is complete. You should always use this function after
zooming or unzooming when dynamic resolution is in use. This ensures that
the image calculation will be complete so the user can see the result before
the animation continues. It may also be useful in combination with filters like
<a blur>motion blur</a>.
<p>
This function deadlocks if used with <a animf>animation functions</a>; don't
do that.
<p>
<emph>Available as</emph>: command

<node file, time, edit, menus>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%file

<menuhead><head>File</head></menuhead>
<menuitems><center>
<p><a loadpos>Load</a>
<p><a savepos>Save</a>
<p><a record>Record</a>
<p><a play>Replay</a>
<p><a saveimg>Save image</a>
<p><a loadexample>Load random example</a>
<p><a savecfg>Save configuration</a>
<p><submenu><a quit>Quit</a>
</center></menuitems>
<node loadpos, , savepos, file>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%loadpos
<head>Load XaoS position file</head>
<p>
Load a XaoS position file (<tt>*.xpf</tt>). 
See the <a format>format description</a> for more information.
<p>
<emph>Available as</emph>: menu item, command line option

<node savepos, loadpos, record, file>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%savepos
<head>Save XaoS position file</head>
<p><emph>Syntax</emph>:(savepos file)
<p>
Save current state to a XaoS position file (<tt>*.xpf</tt>). This file is
human-readable, and can easily be improved by hand after saving, or used as
a base for animations.
See the <a format>format description</a> for more information.
<p>
<emph>Available as</emph>: menu item, command line option, command

<node record, savepos, play, file>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%record
<head>Record animation</head>
<p><emph>Syntax</emph>:(record bool [ file ])
<p>e
Toggle recording to a XaoS animation file (<tt>*.xaf</tt>). This file is
human-readable, and can easily be improved by hand after recording.
See the <a format>format description</a> for more information.
<p>
From the scripting language, <tt>(record #t)</tt> enables recording, and
<tt>(record #f)</tt> disables it.
<p>
<emph>Available as</emph>: menu item, command line option, command

<node play, record, saveimg, file>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%play
<head>Replay animation</head>
<p>
Replay a XaoS animation file (<tt>.xaf</tt>).
<p>
<emph>Available as</emph>: menu item, command line option

<node saveimg, play, loadexample, file>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%saveimg
<head>Save image</head>
<p><emph>Syntax</emph>:(saveimg file)
<p>
Save current state to an image file. This file is in <tt>.png</tt> (portable
network graphics) format, which can be read by many applications varying from
graphics programs all the way to Web browsers.
<p>
This function needs an external library called <tt>libpng</tt>. If the library
wasn't available during compilation, this function is unavailable too.
Please see <tt>INSTALL</tt> for more information about obtaining libpng
and recompiling XaoS.
<p>
<emph>Available as</emph>: menu item, command line option, command

<node loadexample, saveimg, savecfg, file>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%loadexample
<head>Load random example</head>
<p><emph>Syntax</emph>:(loadexample)
<p>
Choose random <tt>.xpf</tt> file from the <tt>examples</tt> directory and
load it.
You might use it as the starting point for next exploration.
<p>
<emph>Available as</emph>: menu item, command line option, command

<node savecfg, loadexample, quit, file>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%savecfg
<head>Save configuration</head>
<p><emph>Syntax</emph>:(savecfg)
<p>
Save current configuration to <tt>~/.xaosrc</tt> (under Unix) or <tt>xaos.cfg</tt>
(under DOS and Windows). XaoS automatically reloads the configuration from this
file when it starts.
<p>
<emph>Available as</emph>: menu item, command line option, command

<node quit, savecfg, ,file>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%quit quitmenu noquit
<head>Quit</head>
<p><emph>Syntax</emph>:(quit)
<p>
Quit XaoS.
<p>
<emph>Available as</emph>: menu item, command line option, command

<node edit, file, fractal, menus>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%edit
<menuhead><head>Edit</head></menuhead>
A fairly ordinary Edit menu.
<menuitems><center>
<p><a undo>Undo</a>
<p><a redo>Redo</a>
<p><a copy>Copy</a>
<p><a paste>Paste</a>
</center></menuitems>
<node undo, , redo, edit>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%undo
<head>Undo</head>
Undo last operation. `Last operation' is quite hard to define in
XaoS (where changes are continuous), so it might be surprising.
I hope it will do what you want.
<p>
<emph>Available as</emph>: menu item
<node redo, undo, copy, edit>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%redo
<head>Redo</head>
Redo last undone operation. See <a undo>undo</a>.
<p>
<emph>Available as</emph>: menu item
<node copy, redo, paste, edit>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%copy
<head>Copy</head>
Copy fractal to clipboard. This is a platform-dependent operation that may
not have an analogue on your platform (e.g. there is no concept of a clipboard
under aalib).
<p>
<emph>Available as</emph>: menu item
<node paste, copy, , edit>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%paste
<head>Paste</head>
Paste fractal from clipboard. This is a platform-dependent operation that may
not have an analogue on your platform (e.g. there is no concept of a clipboard
under aalib).
<p>
<emph>Available as</emph>: menu item

<node fractal, edit, calc, menus>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%fractal
<menuhead><head>Fractal</head></menuhead>
This menu contains all functions related to fractal parameters and display;
you can change things like the formula used, coloring modes, seeds and much
else.

<menuitems><center>
<p><a formula>Formula</a>
<p><submenu><a mformula>formulae</a>
<p><a incoloring>Incoloring mode</a>
<p><a outcoloring>Outcoloring mode</a>
<p><a plane>Plane</a>
<p><submenu><a palettemenu>Palette</a>
<p><a uimandelbrot>Mandelbrot mode</a>
<p><a uiperturbation>Perturbation</a>
<p><a uiview>View</a>
<p><a initstate>Reset to defaults</a>
<p><a tcolor>True-color coloring modes</a>
</center></menuitems>
<node formula, , uimandelbrot, fractal>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%formula
<head>Formula</head>
<p><emph>Syntax</emph>:(formula keyword)
<p>
Set the current fractal formula. <tt>keyword</tt> should be one of the
following:
<dl>
<dt>'mandel
<dd>Standard <a mandel>Mandelbrot set</a>.
<dt>'mandel3
<dd><a mandel3>Mandelbrot set, power 3</a>.
<dt>'mandel4
<dd>Mandelbrot set, power 4.
<dt>'mandel5
<dd>Mandelbrot set, power 5.
<dt>'mandel6
<dd>Mandelbrot set, power 6.
<dt>'newton
<dd><a newton>Newton's approximation method</a>.
<dt>'barnsley
<dd><a barnsley>First Barnsley's formula</a>.
<dt>'octo
<dd><a octal>Fractint's octo</a>.
<dt>'phoenix
<dd><a phoenix>Phoenix</a>.
<dt>'magnet
<dd><a magnet>Magnet</a>.
</dl>
<p>
<emph>Available as</emph>: command

<node uimandelbrot, formula, uiperturbation, fractal>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%uimandelbrot julia juliaseed
<head>Mandelbrot/Julia mode</head>
<p>
Most fractals rendered by XaoS can be represented as Mandelbrot sets or Julias.
Each point in the Mandelbrot set has its own Julia set. To learn more about
this correspondence, see the tutorial on the <tutor julia.xaf>Julia set</tutor>.
<p>
This function switches between Mandelbrot and Julia representations. When
switching to Julia, you need to set the seed--a point selected from the
Mandelbrot set.
<p>
If you run this function from the menu, you are prompted for the Julia seed
as a number. Often, this can be clumsy, and it would be easier to specify a
point with the mouse pointer. If you hit the <tt>M</tt> key instead of
using the menu, the current mouse position is used.
<p>
Good seedpoints lie at the boundaries of the Mandelbrot set; other seeds
usually generate quite a boring fractal. You can also explore various seeds
at high speed using the <a fastjulia>Fast Julia mode</a>.
<p>
Not all fractals have Julias, but XaoS can generate fake Julia sets for
those that do not, which use some Julia-like modification of the formula;
so this function is currently usable for all fractal types.
<p>
<emph>Available as</emph>: menu item
<p><emph>Syntax</emph>:(julia bool)
<p>
This function is used to enable/disable julia mode in animation files. 
<p>
<emph>Available as</emph>: command line option, command
<p><emph>Syntax</emph>:(juliaseed complex)
<p>
Select the current julia seed. 
<p>
<emph>Available as</emph>: command line option, command

<node uiperturbation, uimandelbrot, uiview, fractal>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%uiperturbation perturbation
<head>Perturbation</head>
<p>
Perturbation is a simple trick which changes the point at which orbits start.
Traditionally zero is used, but other values can generate interesting
results too.
<p>
On enabling this function from the menu, you will be asked for a complex
number specifying the perturbation. It is a toggle; selecting it again
resets the perturbation to zero without prompting.
<p>
It can be used to specify a complex number representing a point on the screen.
If you hit the <tt>B</tt> key instead of using the menu, the current mouse
position is used. This too is a toggle, so <tt>B</tt> again will disable
perturbation by setting it to zero.
<p>
This function only has an effect for certain formulae (like the
<a mandel>Mandelbrot set</a>) and only then in <a uimandelbrot>Mandelbrot mode</a>.
<p>
<emph>Available as</emph>: menu item
<p><emph>Syntax</emph>:(perturbation complex)
<p>
This is the scripting-language variation of the perturbation function. Instead
of toggling, you always specify the perturbation to use. Use 0 0 to disable
perturbation.
<p>
<emph>Available as</emph>: command line option, command

<node bailout, maxiter, fastjulia, calc>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%bailout bailout
<head>Bailout</head>
<p>
Bailout is the value which is checked for each point of
the orbit if the point is far enough
from the complex zero point in the current iteration.
If the point is far enough, then the iteration immediately
stops and the starting point on the screen will be
painted with a given colour, depending on the fractal
type and many other settings.
<p>
For the <a mandel>Mandelbrot set</a>
this value is 4. Other fractal types usually
have the same bailout value. For most fractals many bailout values
give more or less similar output. E.g., for the second order
Mandelbrot set one can prove that the sequence |z| (z:=z^2+c) tends to
infinity if and only if |z|>2 for some element z of this sequence.
In XaoS program, Bailout value is the square of this 2, i.e. you can change this
to any value greater than 2 for similar results.
<p>
Other fractal types may use other bailout values. The default
is 4 for each types.
<p>
<emph>Available as</emph>: menu item, command line option, command
<p><emph>Syntax</emph>:(bailout float)
<p>

<node uiview, uiperturbation, initstate, fractal>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%uiview view angle
<head>View</head>
<p>
Set your current viewpoint in the fractal. This function is useful when you have
found some interesting coordinates somewhere (on a web page, perhaps) and you
want to see that position in XaoS.
<p>
In the dialog you will be asked for the <emph>center</emph>, <emph>radius</emph>
and <emph>angle</emph> of the image.
<p>
The center specifies the point which is displayed at the center of the screen.
The radius is the radius of a circle around this point; XaoS will size the image
so that this circle only just fits on the screen. The angle gives the rotation of
the image in degrees.
<p>
People specify fractal coordinates in many ways. Some people use the coordinates
of the upper-left and lower-right visible points, specifying the coordinates as four
numbers <math>x1</math>, <math>y1</math>, <math>x2</math>, <math>y2</math>.
To set the same viewpoint in XaoS, set the real portion of the center to
<math>(x1+x2)/2</math>, the imaginary part of center to <math>(y1+y2)/2</math>, and
the radius to the greater of <math>x2-x1</math> and <math>y2-y1</math>.
<p>
Other programs use a zoom factor instead of a radius. For these, you can set the
radius to <math>2/zoom</math>.
<p>
<emph>Available as</emph>: menu item
<p><emph>Syntax</emph>:(view float float float float)
<p>
This function is used to set the visible area of fractal in animation files.
It doesn't let let you specify the angle, (for that, see the separate function 
<tt>angle</tt>), but lets you specify an ellipse instead of a circle. You can
specify both a real and an imaginary radius, so you have better control over the
area that will be visible. XaoS will size the image so that the ellipse only just
fits on the screen.
<p>
<emph>Available as</emph>: command line option, command
<p><emph>Syntax</emph>:(angle float)
<p>
Set the rotation angle in degrees. By default this causes recalculation of the
screen. You can enable the <a rotate>fast rotation mode</a>, which lets you
rotate the screen without recalculation; but it slows down other things, so
don't forget to disable it later.
<p>
<emph>Available as</emph>: command line option, command

<node initstate, uiview, plane, fractal>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%initstate
<head>Reset to defaults</head>
<p><emph>Syntax</emph>:(initstate)
<p>
This function resets most of XaoS's values to their defaults. It is useful when
you get lost and want to start from the beginning. It should also be used
as the first command of every animation file, to ensure that the file is always
played with the same settings in effect.
<p>
<emph>Available as</emph>: menu item, command line option, command

<node plane, initstate, incoloring, fractal>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%plane mplane plane0 plane1 plane2 plane3 plane4 plane5 plane6 plane7 plane8 plane9 plane10
<head>Plane</head>
<p><emph>Syntax</emph>:(plane integer)
<p>
All fractals displayed by XaoS are functions with a complex parameter.
They can be be displayed in the normal complex plane where the <tt>x</tt>
coordinate is the real part of the number and the <tt>y</tt> is imaginary;
but they can also be displayed differently:
<dl>
<dt><math>mu</math>
<dd>Normal complex plane (default)
<dt><math>1/mu</math>
        <dd>Inversion--infinity is at 0 and
        0 is at infinity.
<dt><math>1/(mu+0.25)</math>
        <dd>Similar to inversion, but moves
        the center outside the Mandelbrot set,
        so it looks parabolic.
<dt><math>lambda plane</math>, <math>1/lambda</math>, <math>1/lambda-1</math>
<dd>Lambda plane and its inversion, and with a different center.
<dt><math>1/(mu-1.40115)</math>
        <dd>A very interesting mode for the
        Mandelbrot set, this makes small
        things large, for easier browsing
        of the set's details.
</dl>
The <tutor plane.xaf>tutorial about planes</tutor> has some examples.
<p>

<p>
In the scripting language, the planes are numbered as follows:
<p>
<dl>
<dt>0
<dd><math>mu</math>
<dt>1
<dd><math>1/mu</math>
<dt>2
<dd><math>1/(mu+0.25)</math>
<dt>3
<dd><math>lambda</math>
<dt>4
<dd><math>1/lambda</math>
<dt>5
<dd><math>1/(lambda-1)</math>
<dt>6
<dd><math>1/(mu-1.40115)</math>
</dl>
<p>
<emph>Available as</emph>: command line option, command

<node incoloring, plane, outcoloring, fractal>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%incoloring mincoloring in1 in2 in3 in4 in5 in6 in7 in8 in9 in10 in0
<head>Inside coloring mode</head>
<p><emph>Syntax</emph>:(incoloring integer)
<p>
Areas inside the set are usually filled in black, but this is only a convention;
you could color them in differently to make the fractal look more interesting.
The only method available to make areas inside the set visible is to display
the value of the latest orbit as the value of each pixel.
<p>
The <tutor incolor.xaf>tutorial on incoloring</tutor> has more information and
examples.
<p>
XaoS has many different ways to show that value. The cryptic names of the modes
are mathematical formulae, where <emph>real</emph> means the real part of the
latest orbit, and <emph>imag</emph> means the imaginary part. <emph>zmag</emph>
uses the magnitude of the value. The <emph>Decomposition-like</emph> method uses
the angle of the orbit. Also, <a tcolor>truecolor</a> incoloring modes are available, that
display one value in each of the red, blue and green color planes (or, for some
modes, in each of the hue, saturation and value planes).

In the scripting language, the incoloring mode is specified by one of the
following integers:
<p>
<dl>
<dt>0
<dd><math>0</math> (default)
<dt>1
<dd><math>zmag</math>
<dt>2
<dd>Decomposition-like
<dt>3
<dd><math>real/imag</math>
<dt>4
<dd><math>abs(abs(c)-abs(r))</math>
<dt>5
<dd><math>cos(mag)</math>
<dt>6
<dd><math>mag*cos(real^2)</math>
<dt>7
<dd><math>sin(real^2-imag^2)</math>
<dt>8
<dd><math>atan(real*imag*creal*cimag)</math>
<dt>9
<dd>squares
<dt>10
<dd>Truecolor. To set exact parameters for truecolor coloring use the
<a tcolor><tt>tcolor</tt></a> command.
</dl>
<p>
<emph>Available as</emph>: command line option, command

<node outcoloring, incoloring, tcolor, fractal>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%outcoloring moutcoloring out1 out2 out3 out4 out5 out6 out7 out8 out9 out10 out0
<head>Outside coloring mode</head>
<p><emph>Syntax</emph>:(outcoloring integer)
<p>
Outcoloring modes are similar to <a incoloring>incoloring modes</a>, but indicate
how to display the areas outside the set instead. As with incoloring modes, the
value of the latest orbit can be used to determine the color of each pixel, but the
default is to use the number of iterations needed for the value at that point to become
recognisably divergent as the color.
<p>
The <tutor outcolor.xaf>tutorial on outcoloring</tutor> has more information and
examples.
<p>
The cryptic names of the modes are mathematical formulae, where <emph>iter</emph>
means the number of iterations required for the value to become recognisably divergent,
<emph>real</emph> means the real part of the latest orbit, and <emph>imag</emph>
means the imaginary part. <emph>binary decomposition</emph> uses a different color
when the imaginary part of the orbit is lower than zero, and <emph>smooth</emph>
attempts to remove stripes and discontinuities. Also, <a tcolor>truecolor</a> outcoloring
modes are available, that display one value in each of the red, blue and green color planes
(or, for some modes, in each of the hue, saturation and value planes).
<p>
In the scripting language, the outcoloring mode is specified by one of the following
integers:
<p>
<dl>
<dt>0
<dd><math>iter</math> (default)
<dt>1
<dd><math>iter+real</math>
<dt>2
<dd><math>iter+imag</math>
<dt>3
<dd><math>iter+real/imag</math>
<dt>4
<dd><math>iter+real+imag+real/imag</math>
<dt>5
<dd>binary decomposition
<dt>6
<dd>biomorphs
<dt>7
<dd>potential
<dt>8
<dd>color decomposition
<dt>9
<dd>smooth
<dt>10
<dd>True-color outcoloring mode. To set exact parameters for truecolor coloring use <a tcolor><tt>outtcoloring</tt></a>.
</dl>
<p>
<emph>Available as</emph>: command line option, command

<node tcolor, outcoloring, , fractal>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%tcolor intcoloring outtcoloring tincoloring toucoloring int0 int1 int2 int3 int4 int5 int6 int7 int8 int9 int10 int11 outt0 outt1 outt2 outt3 outt4 outt5 outt6 outt7 outt8 outt9 outt10 outt11
<head>Truecolor coloring mode</head>
<p><emph>Syntax</emph>:(intcoloring integer)
<p><emph>Syntax</emph>:(outtcoloring integer)
<p>
Truecolor coloring modes are similar to <a incoloring>incolor</a> and 
<a outcoloring>outcolor</a> coloring modes; but instead of using a palette,
they directly calculate the red, green and blue components of the color.
This lets you display more parameters at once, and produces interesting
and often attractive results. On 8bpp displays you need to enable the
<a palettef>palette emulator filter</a> first to see anything, amd the quality
won't be so good, as far fewer colors are available per parameter.
<p>
The <tutor truecol.xaf>tutorial on truecolor coloring modes</tutor> has more
information and examples.
<p>
The cryptic names of the modes are always three mathematical formulae (one for
each color component), where <emph>real</emph> means the real part of the latest
orbit, and <emph>imag</emph> means the imaginary part. 
<p>
To enable inside/outside truecolor coloring mode in the scripting language,
set <tt>incoloring</tt>/<tt>outcoloring</tt> value to 10 (truecolor coloring
mode) before (or after) calling <tt>intcoloring</tt> or <tt>outtcoloring</tt>.
<p>
In the scripting language, the coloring mode is specified by one of the following
integers:
<p>
<dl>
<dt>0
<dd>black
<dt>1
<dd><math>re*im</math> <math>sin(re^2)</math> angle
<dt>2
<dd><math>sin(re)</math> <math>sin(im)</math> <math>sin(square)</math>
<dt>3
<dd>hsv
<dt>4
<dd>hsv2
<dt>5
<dd><math>cos(re^c)</math> <math>cos(im^2)</math> <math>cos(square)</math>
<dt>6
<dd><math>abs(re^2)</math> <math>abs(im^2)</math> <math>abs(square)</math>
<dt>7
<dd><math>re*im</math> <math>re*re</math> <math>im*im</math>
<dt>8
<dd><math>abs(im*cim)</math> <math>abs(re*cre)</math> <math>abs(re*cim)</math>
<dt>9
<dd><math>abs(re*im-csqr)</math> <math>abs(re^2-csqr)</math> <math>abs(im^2-csqr)</math>
</dl>
<p>
<emph>Available as</emph>: command line option, command

<node calc, fractal, mfilter, menus>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%calc

<menuhead><head>Calculation</head></menuhead>
This menu contains functions that control calculation parameters such as
the maximum iteration count and periodicity checking.
<menuitems><center>
<p><a range>Solid guessing</a>
<p><submenu><a dynamic>Dynamic resolution</a>
<p><a periodicity>Periodicity checking</a>
<p><a maxiter>Iterations</a>
<p><a bailout>Bailout</a>
<p><a fastjulia>Fast Julia mode</a>
<p><a dynamic>Dynamic resolution</a>
<p><a rotate>Rotation</a>
</center></menuitems>
<node range, , periodicity, calc>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%range mguess guess0 guess1 guess2 guess3 guess4 guess5 guess6 guess7 guess8 guess9 guessall
<head>Solid guessing range</head>
<p><emph>Syntax</emph>:(range integer)
<p>
XaoS has a solid guessing optimization: if all corners of a rectangle have
the same color, it assumes that the whole rectangle is a solid colored block,
and doesn't calculate points inside the rectangle. This optimization saves
lots of calculation, but sometimes introduces errors. This value alters the
maximum size of the rectangle that can be guessed at one time. The default
value is 3; use 0 to disable the optimization.
<p>
<emph>Available as</emph>: command line option, command

<node periodicity, range, maxiter, calc>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%periodicity
<head>Periodicity checking</head>
<p><emph>Syntax</emph>:(periodicity bool)
<p>
Periodicity checking is one way to speed up the calculation. Areas inside the
set always need <a maxiter><tt>maxiter</tt></a> iterations to determine that
the point is probably inside the set (while it is rare for areas outside to
need anywhere near that much). Often the orbital trajectory falls into a
periodic, repeating cycle; if that can be detected, the calculation can be
stopped early, as there's no way that the orbit can ever leave the cycle
again (hence it cannot diverge, hence the point must be inside the set).
<p>
Implementating this method efficiently is quite problematic. It slows down
the cases where cycles are not found, because cycle-checking is quite hard work
and has to take place for all points, even those that don't become cyclic.
Because of the inexactness of floating-point calculations, the cycles are
never exact, so you need to use an error value. Higher error values mean that
cycles will be detected sooner, while lower error values increase the
exactness of the calculation. Higher values can introduce serious errors,
especially at the front of the Mandelbrot set. XaoS detects this automatically
and corrects for it in most cases, but sometimes it might be wrong. Also,
other optimizations in XaoS (such as boundary tracing) don't give this method
much of a chance to run, since areas inside the set are usually not
calculated at all.
<p>
That's why the advantages of this optimization are questionable. You should
probably experiment with enabling and disabling it. Sometimes XaoS is faster
with this enabled, sometimes when disabled. Also, this method works only
when <a incoloring>incoloring</a> methods are disabled, and only for some
fractal types (some fractal types, e.g. newton, don't have any concept of
an area `inside the set' at all.)
<p>
The tutorial chapter ``<tutor escape.xaf>Escape time fractals</tutor>'' has
more information on fractal calculation in XaoS, and there is a lengthy
section in the hacker's manual (<tt>xaosdev.texinfo</tt>) devoted to the
subject.
<p>
<emph>Available as</emph>: menu item, command line option, command

<node maxiter, periodicity, bailout, calc>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%maxiter
<head>Iterations</head>
<p><emph>Syntax</emph>:(maxiter integer)
<p>
When the fractal set is calculated, a orbital trajectory is examined for each
point. If the orbit diverges to infinity, the point is outside the set.
Otherwise, the point is inside the set. For exact calculations, you need to
know the entire orbital trajectory, which is infinitely long for areas inside
the set, so fractals cannot be calculated exactly. By default, XaoS calculates
at most 170 positions (iterations) and then gives up; if the point is still
inside the bail-out value, it guesses that the point is inside the set.
<p>
When zoomed into a detailed area, especially one close to the set boundary,
this value could become too low, and the fractal will become boring.
You might try increasing this value if you want to get the image interesting
again; but this necessarily slows down the calculation at the same time.
<p>
The tutorial chapter ``<tutor escape.xaf>Escape time fractals</tutor>'' has
more information on fractal calculation in XaoS, and there is a lengthy
section in the hacker's manual (<tt>xaosdev.texinfo</tt>) devoted to the
subject.
<p>
<emph>Available as</emph>: menu item, command line option, command

<node fastjulia, bailout, dynamic, calc>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%fastjulia
<head>Fast Julia mode</head>
<p><emph>Syntax</emph>:(fastjulia bool)
<p>
By default, changing the seed for the Julia set requires recalculation of the
image (which is quite slow). It's a nice effect to change the seed smoothly and
show the Julia set morphing as the seed changes. XaoS has a special algorithm
which can calculate such morphings in realtime. It is very inexact, but it is
good enough for a fast preview.
<p>
If you want to select a good seedpoint, enable fast Julia mode and find a
nice place by dragging with the first mouse button depressed; then change to
the <a uimandelbrot>Julia mode</a> to see the exact image.
<p>
<emph>Available as</emph>: menu item, command line option, command

<node dynamic, fastjulia, rotate, calc>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%dynamic nodynamic dynamicanimation dynamicnew fastmode 

<menuhead><head>Dynamic resolution</head></menuhead>
<p><emph>Syntax</emph>:(fastmode keyword)
<p>
XaoS performs many optimizations, but fairly often this is not enough. In order
to keep a high framerate, XaoS automatically lowers the resolution of the image,
increasing it when there is time for more calculation. This feature is enabled by
default when animating, but you might also like to enable it for new images
(which makes the image `come into focus' when it is recalculated from scratch for
whatever reason), or disable it completely if you don't like it.
<p>
In the scripting languge, the keyword should be one of the following:
<dl>
<dt><tt>'never</tt>
<dd>Disable dynamic resolution
<dt><tt>'animate</tt>
<dd>Use only for animations (default)
<dt><tt>'new</tt>
<dd>Use also for new images
</dl>
<node rotate, dynamic, , calc>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%rotate norotate controtate mouserotate rotationspeed autorotate fastrotate

<menuhead><head>Image rotation</head></menuhead>

XaoS has support for rotation of the image to any angle. By default, changing
the angle requires recalculation of the whole screen, but when
<emph>fast rotation mode</emph> is enabled, the angle can be changed smoothly.
In this mode XaoS calculates a larger non-rotated image and rotates it when
needed, so it increases memory requirements and slows XaoS down; hence, it
should be disabled when rotation is not being used.
<p>
The user interface provides two rotation modes--<emph>rotate by
mouse</emph> which allows the angle to be changed by dragging with the first
mouse button depressed, and <emph>continuous rotation mode</emph>, where the image
is rotated clockwise continuously, and the arrow keys can be used to change
the rotiation speed.
<p><emph>Syntax</emph>:(fastrotate bool)
<p>
This function is used to enable and disable fast rotation mode.
<emph>Available as</emph>: command line option, command
<head>Automatic rotation</head>
<p><emph>Syntax</emph>:(autorotate bool)
<p>
Use this function to enable continuous rotation. In the scripting language you
can also use <a morphangle><tt>morphangle</tt></a> to get an outwardly similar
but more controllable effect.
<p><emph>Syntax</emph>:(rotationspeed float)
<p>
Specify the speed of continuous rotation, in degrees per second.
Negative values are allowed and rotate anticlockwise.
<p>
<emph>Available as</emph>: menu item, command line option, command



<node mfilter, calc, ui, menus>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%mfilter

<menuhead><head>Filters</head></menuhead>
Filters are a post-calculation effect applied to the resulting image. They
can do things like motion blurring, edge detection, emulation of palettes
or truecolor on displays that can't handle them, and such things. There is
a <tutor filter.xaf>tutorial chapter</tutor> about them.
<p>
<menuitems><center>
<p><a filter>Filter command</a>
<p><a edge>Edge detection</a>
<p><a edge2>Edge detection2</a>
<p><a starfield>Starfield</a>
<p><a stereogram>Random dot stereogram</a>
<p><a interlace>Interlace filter</a>
<p><a blur>Motion blur</a>
<p><a emboss>Emboss</a>
<p><a palettef>Palette emulator</a>
<p><a anti>Antialiasing</a>
<p><a truecolor>Truecolor emulator</a>
</center></menuitems>
<node filter, , edge, mfilter>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%filter
<head>Filter command</head>
<p><emph>Syntax</emph>:(filter keyword bool)
<p>
This command is used to enable or disable <a mfilter>filters</a>.
The <emph>keyword</emph> specifies the filter to change, and should be one of
the following:
<p>
<dl>
<dt><tt>'edge</tt>
<dd><a edge>Edge detection</a>
<dt><tt>'edge2</tt>
<dd><a edge2>Edge detection2</a>
<dt><tt>'starfield</tt>
<dd><a starfield>Starfield</a>
<dt><tt>'stereogram</tt>
<dd><a stereogram>Random dot stereogram</a>
<dt><tt>'interlace</tt>
<dd><a interlace>Interlace filter</a>
<dt><tt>'blur</tt>
<dd><a blur>Motion blur</a>
<dt><tt>'emboss</tt>
<dd><a emboss>Emboss</a>
<dt><tt>'palette</tt>
<dd><a palette>Palette emulator</a>
<dt><tt>'anti</tt>
<dd><a anti>Antialiasing</a>
<dt><tt>'truecolor</tt>
<dd><a truecolor>Truecolor</a>
</dl>
<p>
<emph>Available as</emph>: command
<node edge, filter, edge2, mfilter>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%edge
<head>Edge detection</head>
<p>
This filter is a standard edge detection algorithm; solid areas are filled
in black. Some fractals look very interesting with this filter (and some
areas of some fractals just look like noise). This version of the filter produces
relatively wide lines, so is useful at higher resolutions. The filter
<a edge2>edge detection2</a> makes thinner lines, for the low resolution modes.
<notex>
<p>
<a filter>More information about filters</a>
</notex>
<p>
<emph>Available as</emph>: menu item, command line option

<node edge2, edge, starfield, mfilter>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%edge2
<head>Edge detection2</head>
<p>
This filter is a standard edge detection algorithm; solid areas are filled
in black. Some fractals look very interesting with this filter (and some
areas of some fractals just look like noise). This version of the filter produces
relatively tight lines, so is useful at lower resolutions. The filter
<a edge>edge detection</a> makes thinner lines, for the high resolution modes.
<notex>
<p>
<a filter>More information about filters</a>
</notex>
<p>
<emph>Available as</emph>: menu item, command line option

<node starfield, edge2, stereogram, mfilter>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%starfield
<head>Starfield</head>
<p>
The starfield filter generates random stars whose density depends on the
iteration count. Choose your favorite spiral fractal and enable this filter
to get a Grand Design spiral galaxy :)
<notex>
<p>
<a filter>More information about filters</a>
</notex>
<p>
<emph>Available as</emph>: menu item, command line option

<node stereogram, starfield, interlace, mfilter>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%stereogram
<head>Random dot stereogram</head>
<p>
   Fractal images are good as a base for random dot stereograms. In
   case you don't know what these are, please point your browser to
   Google or another search engine and find some articles about such
   images, because learning to read such images takes some effort. They
   make it possible to generate three dimensional images on a normal monitor
   without any additional hardware, by exploiting bugs in the human brain
   (although you need two working eyes, and some people never learn to
   see them; they can simply ignore this feature).
<p>
   XaoS is able to generate these images in animations, so you may use
   all normal XaoS functions (except palette changing and palette rotation,
   which makes no sense applied to a stereogram). To make the animation yet
   more exciting, XaoS emulates ``falling'' into the set; while you zoom in,
   your distance from the set drops and drops--but you never hit it; when the
   set reaches the level of your monitor, the distance is changed again so
   you are far away.
<p>
   To make this work right, XaoS needs to know the <emph>exact size of your
   monitor</emph>. Because most platforms have no way to determine this, you need to
   use <emph>command line options</emph> to tune it. If it's not set or is wrong,
   the stereograms will probably be impossible to see (if your monitor is too
   big or resolution too low), or the images will seem to be shallow (if your
   monitor is too small or resolution too high).
<p>
   By default XaoS expects my 15" monitor (29.0cm x 21.5 cm). Another
   cause of problems is the virtual screen supported by some windowed
   environments (like some X servers) that makes a program think that the
   resolution is higher than it actually is, and you see only part of
   this extra-large screen.
<p>
   The worst thing you could possibly do is to run full-screen XaoS in some
   graphical windowing system (OS/2 on top of Windows or Wine on top of Linux,
   perhaps) where XaoS can't tell the real size of its window at all. In such
   cases, it's normally better (not to mention faster) to run XaoS natively,
   rather than under such an emulation layer.
<p>
   The following command line options are provided to specify sizes:
<p>
<dl>
<dt><tt>-screenwidth</tt>, <tt>-screenheight</tt>
          <dd>Lets you specify the size of your screen in centimeters. Note that
          you need to specify the size of the visible image on the monitor, not
          the size with edge borders, or the size of the tube. The simplistic
          `my monitor is 17", just turn 17" into centimeters' doesn't work;
          that 17" is a marketing figure and has only a vague connection to
          reality. Get out a ruler and measure it.

   <dt><tt>-pixelwidth</tt>, <tt>-pixelheight</tt>
          <dd>Lets you specify the exact size of a single pixel, if XaoS cannot
          determine this for itself from your screen size.
</dl>
<p>
   These options are used by some other parts of XaoS as well, so you should
   use them even when you don't want to see stereograms. You should probably
   write a small starting script (or alias, or shortcut; whatever your environment
   uses) that passes the correct parameters to XaoS.
<p>
   If the window is <emph>smaller than 8cm in any direction</emph>, you will probably be
   unable to see anything; make the window bigger.

   The correct way to see XaoS stereograms is:
<dl>
    <dt>1
    <dd>Start XaoS with options specifying the exact size of your screen or one pixel on it
     <dt>2
     <dd>Sit 60cm away from monitor
     <dt>3
     <dd>If you use a windowed environment, resize XaoS's window to make it wider than, say, 15 cm.
     <dt>4
     <dd>Enable the filter (by pressing <tt>E</tt>)
     <dt>5
     <dd>focus on a point far away from the monitor (try to use your
       own reflection, if your monitor's not antireflective); the random blurring should
       eventually fall into the pattern of a Mandelbrot set.
     <dt>6
     <dd>Carefully use your mouse to zoom into interesting areas
     (it is easy to lose concentration when you are not trained; but you can use
     the autopilot...)
     <dt>7
     <dd>Enjoy animation :)
</dl>
<p>
   If you still can't see the stereograms, it could be that the fractal, or your eye,
   is deformed. A deformed fractal can be caused by your specifying your monitor size
   wrongly. Visual problems that damage depth perception, as well as problems like
   astigmatism, can make it impossible to see stereograms at all.
<notex>
<p>
<a filter>More information about filters</a>
</notex>
   
<p>
<emph>Available as</emph>: menu item, command line option

<node interlace, stereogram, blur, mfilter>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%interlace
<head>Interlace filter</head>
<p>
The interlace filter halves the horizontal resolution, and in each frame alternates
between drawing only the even and only the odd lines. This speeds up the
calculation, and in higher resolutions produces a motion-blur-like effect.
<notex>
<p>
<a filter>More information about filters</a>
</notex>
<p>
<emph>Available as</emph>: menu item, command line option

<node blur, interlace, emboss, mfilter>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%blur
<head>Motion blur</head>
<p>
Motion blur mixes the current frame with previous ones to produce a
motion-blur effect. It might be rather slow in 16bpp truecolor modes. The best
results can probably be seen in 8bpp modes, so you might want to enable the
<a palettef>palette filter</a> first.
<notex>
<p>
<a filter>More information about filters</a>
</notex>
<p>
<emph>Available as</emph>: menu item, command line option

<node emboss, blur, palettef, mfilter>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%emboss
<head>Emboss</head>
<p>
This is a standard emboss filter, as seen in programs such as the GIMP or
Photoshop. It produces especially nice results with the smooth
<a outcoloring>outcoloring mode</a>.
<notex>
<p>
<a filter>More information about filters</a>
</notex>
<p>
<emph>Available as</emph>: menu item, command line option

<node palettef, emboss, anti, mfilter>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%palettef
<head>Palette emulator</head>
<p>
XaoS can work in either palette or <a truecolor>truecolor</a> mode. Both modes
have advantages and disadvantages. Palette mode allows effects such as palette
rotation, while truecolor mode allows smoother <a incoloring>incoloring</a>
and <a outcoloring>outcoloring</a> modes and the
<a tcolor>truecolor coloring</a> modes. If your display is truecolor, you
can enable this filter to get palette emulation (albeit not as cheaply as in
a real paletted mode).
<notex>
<p>
<a filter>More information about filters</a>
</notex>
<p>
<emph>Available as</emph>: menu item, command line option

<node anti, palettef, truecolor, mfilter>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%anti
<head>Antialiasing</head>
<p>
Antialiasing is a technique to increase image quality by eliminating jagged
edges. XaoS calculates four values for each pixel (on the subpixel boundaries)
and uses the average of them for the pixel value.
<p>
This filter slows XaoS down a <emph>lot</emph> and greatly increases memory
requirements. It is useful mainly when you want to save images and want to make
them look as nice as possible. Antialiasing also helps a lot when you want to
encode JPEG or MPEG files; they are much shorter if antialiased (MPEG and JPEG
hate jagged edges).
<notex>
<p>
<a filter>More information about filters</a>
</notex>
<p>
<emph>Available as</emph>: menu item, command line option

<node truecolor, anti, , mfilter>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%truecolor
<head>Truecolor emulator</head>
<p>
XaoS can work in either <a palettef>palette</a> or truecolor mode. Both modes
have advantages and disadvantages. Palette mode allows effects such as palette
rotation, while truecolor mode allows smoother <a incoloring>incoloring</a>
and <a outcoloring>outcoloring</a> modes and the
<a tcolor>truecolor coloring</a> modes. If your display is 8bpp, you can enable
this filter to get truecolor emulation (but, obviously, not with as many colors
as a real truecolor display).
<p>
<a filter>More information about filters</a>
<p>
<emph>Available as</emph>: menu item, command line option

<node ui, mfilter, misc, menus>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%ui uia

<menuhead><head>UI</head></menuhead>

This menu contains functions to control the user interface layer of XaoS:
zooming speed, the autopilot, realtime status information, and so on.

<menuitems><center>
<p><a speed>Zooming speed</a>
<p><a letterspersec>Letters per second</a>
<p><a autopilot>Autopilot</a>
<p><a recalculate>Recalculate</a>
<p><a interrupt>Interrupt</a>
<p><a nogui>Disable XaoS's builtin GUI</a>
<p><a status>Status</a>
<p><a ministatus>Ministatus</a>
</center></menuitems>
<node speed, , letterspersec, ui>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%speed speedup maxstep
<head>Zooming speed</head>
<p><emph>Syntax</emph>:(speed float)
<p>
Change zooming speed, where 1 is the default, 2 means twice as fast, and so on.
<p>
<emph>Available as</emph>: menu item, command line option, command
<p>
In the scripting language you can use the following functions for better
control:
<p><emph>Syntax</emph>:(maxstep float)
<p>
Selects the zooming/unzooming speed. The parameter specifies how much of the
range will be removed each twentieth of a second; 0 means nothing, 1 means
everything (the parameter obviously has to be less than 1).
Higher values mean faster zooming.
<p>
<emph>Available as</emph>: command
<p><emph>Syntax</emph>:(speedup float)
When zooming/unzooming, every twentieth of a second the <tt>speedup</tt>
value is added to the current step until <tt>maxstep</tt> is reached.
So this value selects the rate at which zooming stops and starts.
Both these functions are more for internal use of XaoS then for manually
written scripts, but they could come in useful nonetheless.
<p>
<emph>Available as</emph>: command

<node letterspersec, speed, autopilot, ui>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%letterspersec animletterspersec
<head>Letters per second</head>
<p><emph>Syntax</emph>:(letterspersec integer)
<p>
Speed of subtitles for the <a textsleep><tt>textsleep</tt></a> function.
The user can set this value to suit; it can also be changed with the left and
right arrow keys during animation replay.
<p>
<emph>Available as</emph>: command line option, command

<node autopilot, letterspersec, recalculate, ui>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%autopilot
<head>Autopilot</head>
<p><emph>Syntax</emph>:(autopilot bool)
<p>
 To make XaoS yet more impressive, we made a special autopilot mode that
 automatically drives into interesting boundaries of the set; you should
 press <tt>A</tt>, play your favorite music, drink coffee and relax. I never
 tried this but it should be really relaxing! Many pictures in the XaoS
 gallery were discovered using the autopilot.
<p>
 The autopilot also has some additional features. It backtracks if the
 zoomed picture is not interesting anymore, and can detect when it's zoomed
 into really a boring part of the fractal or reached the limit of floating
 point arithmetic on the platform, and restart zooming from the top.
<p>
<emph>Available as</emph>: menu item, command line option, command

<node recalculate, autopilot, interrupt, ui>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%recalculate
<head>Recalculate</head>
<p><emph>Syntax</emph>:(recalculate)
<p>
Recalculate current fractal. This should be used when the fractal on the
screen is strange because of error propagation caused by
<a range>solid guessing</a>.
<p>
<emph>Available as</emph>: menu item, command line option, command

<node interrupt, recalculate, nogui, ui>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%interrupt animinterrupt
<head>Interrupt</head>
<p><emph>Syntax</emph>:(interrupt)
<p>
Interrupt current calculation.
<p>
<emph>Available as</emph>: menu item, command line option, command


<node nogui, interrupt, status, ui>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%nogui
<head>Disable XaoS's builtin GUI</head>
<p><emph>Syntax</emph>:(nogui bool)
<p>
Disable XaoS menus and dialogs. This function should be used by external GUI
programs; these manipulate XaoS via a pipe, so the internal GUI should be
disabled at the same time. See the hacker's manual (<tt>xaosdev.texinfo</tt>)
for more details.
<p>
<emph>Available as</emph>: menu item, command line option, command

<node status, nogui, ministatus, ui>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%status animstatus
<head>Status</head>
<p><emph>Syntax</emph>:(status bool)
<p>
Enable/disable status information. This displays some useful information
about the current fractal, such as viewpoint etc. (In low-resolution modes it
also almost completely obscures the current fractal...)
<p>
<emph>Available as</emph>: menu item, command line option, command

<node ministatus, status, , ui>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%ministatus animministatus
<head>Ministatus</head>
<p><emph>Syntax</emph>:(ministatus bool)
<p>
Enable/disable status line. This contains basic information such as how
much you are zoomed and the framerate.
<p>
<emph>Available as</emph>: menu item, command line option, command

<node misc, ui, helpmenu, menus>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%misc

<menuhead><head>Misc</head></menuhead>
Miscellaneous functions.
<menuitems><center>
<p><a command>Command</a>
<p><a renderanim>Render animation</a>
<p><a clearscreen>Clear screen</a>
<p><a display>Display fractal</a>
<p><a text>Display text</a>
<p><a color>Color</a>
<p><submenu><a xtextpos>Horizontal text position</a>
<p><submenu><a ytextpos>Vertical text position</a>
<p><a textposition>Text position</a>
<p><a message>Message</a>
</center></menuitems>
<node command, , renderanim, misc>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%command
<head>Command</head>
<p>
You can invoke all XaoS functions using a simple command language reminiscent
of Scheme. This option lets you run a single command. If you want to run more
than one, you might want to use an <a format>XaoS animation file</a> instead;
they are written in the same language.
<p>
<emph>Available as</emph>: menu item

<node renderanim, command, clearscreen, misc>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%renderanim
<head>Render animation</head>
<p>
Render an animation to image files. See <a video>How to encode video files</a>
for more information.
<p>
<emph>Available as</emph>: menu item,
<node clearscreen, renderanim, display, misc>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%clearscreen
<head>Clear screen</head>
<p><emph>Syntax</emph>:(clearscreen)
<p>
Clear the screen. To display the fractal again, use <a display><tt>display</tt></a>.
This function is mainly useful in tutorials and similar animations.
<p>
<emph>Available as</emph>: menu item, command

<node display, clearscreen, text, misc>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%display
<head>Display fractal</head>
<p><emph>Syntax</emph>:(display)
<p>
Display fractal. This functions reverses the effect of the <tt>clearscreen</tt>,
line drawing and text output functions.
<p>
<emph>Available as</emph>: menu item, command

<node text, display, color, misc>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%text
<head>Display text</head>
<p><emph>Syntax</emph>:(text string)
<p>
Display the given text on the screen. This function is mainly useful in tutorials.
Text should be cleared by printing lots of spaces, or using the
<a clearscreen><tt>clearscreen</tt></a> or <a display><tt>display</tt></a>
functions. You might also want to use the <a textposition><tt>textposition</tt></a>
function to select the part of the screen to display the text on.
<p>
To wait for the user to read the text, you can use the <a textsleep><tt>textsleep</tt></a>
function.
<p>
Example:
<p><tt>
(clearscreen)<br>
(textposition 'center 'middle)<br>
(text "Welcome into my animation")<br>
(textsleep)<br>
(display)<br>
</tt><p>
<emph>Available as</emph>: menu item, command line option, command

<node color, text, textposition, misc>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%color
<head>Color</head>
<p><emph>Syntax</emph>:(color keyword)
<p>
Change text and line color. <emph>keyword</emph> should be one of <tt>'white</tt>,
<tt>'black</tt> and <tt>'red</tt>.
<p>
<emph>Available as</emph>: menu item, command line option, command

<node textposition, color, message, misc>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%textposition 
<head>Text position</head>
<p><emph>Syntax</emph>:(textposition keyword keyword)
<p>
Select <a text>text</a> position. The first keyword specifies the horizontal
position, the second the vertical position. The horizontal position should be
one of <tt>'left</tt>, <tt>'center</tt>, and <tt>'right</tt>.
The vertical should be one of <tt>'top</tt>, <tt>'middle</tt>, and <tt>'bottom</tt>.
<p>
<emph>Available as</emph>: command line option, command

<node message, textposition, , misc>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%message
<head>Message</head>
<p><emph>Syntax</emph>:(message string)
<p>
This function is almost identical to the <a text><tt>text</tt></a> function,
except that it uses message catalogs in the <tt>catalog</tt> directory to
translate messages into other languages. It should be used only in the multi-lingual
XaoS tutorials.
<p>
<emph>Available as</emph>: command line option, command

<node helpmenu, misc, xtextpos, menus>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%helpmenu

<menuhead><head>Help</head></menuhead>
This menu contains help and tutorials.
<notex>
<menuitems><center>
<p><a help>Help</a>
</center></menuitems>
<node help, , , helpmenu>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%help
<head>Help</head>
<p><emph>Syntax</emph>:(help)
<p>
Display the main help page.
<p>
<emph>Available as</emph>: menu item, command line option, command
</notex>

<node xtextpos, helpmenu, ytextpos, menus>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%xtextpos

<menuhead><head>Horizontal text position</head></menuhead>
Select the horizontal position used to display <a text>text</a>.
It can be placed at the left, in the center or at the right.
<notex>
<menuitems><center>
<p><a xtextleft>Left</a>
<p><a xtextcenter>Center</a>
<p><a xtexteight>Right</a>
</center></menuitems>
<node xtextleft, , xtextcenter, xtextpos>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%xtextleft
<head>Left</head>
<p>
Draw <a text>text</a> at the left side of the screen.
<p>
<emph>Available as</emph>: menu item

<node xtextcenter, xtextleft, xtexteight, xtextpos>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%xtextcenter
<head>Center</head>
<p>
Draw <a text>text</a> in the center of the screen.
<p>
<emph>Available as</emph>: menu item

<node xtexteight, xtextcenter, , xtextpos>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%xtexteight
<head>Right</head>
<p>
Draw <a text>text</a> at the right side of the screen.
<p>
<emph>Available as</emph>: menu item
</notex>

<node ytextpos, xtextpos, mformula, menus>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%ytextpos

<menuhead><head>Vertical text position</head></menuhead>
Select the vertical position used to display <a text>text</a>. It can be
placed at the top, in the middle or at the bottom of the screen.
<notex>
<menuitems><center>
<p><a ytextup>Up</a>
<p><a ytextmiddle>Middle</a>
<p><a ytextbottom>Bottom</a>
</center></menuitems>
<node ytextup, , ytextmiddle, ytextpos>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%ytextup
<head>Up</head>
<p>
Draw <a text>text</a> at the top of the screen.
<p>
<emph>Available as</emph>: menu item

<node ytextmiddle, ytextup, ytextbottom, ytextpos>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%ytextmiddle
<head>Middle</head>
<p>
Draw <a text>text</a> in the middle of the screen.
<p>
<emph>Available as</emph>: menu item

<node ytextbottom, ytextmiddle, , ytextpos>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%ytextbottom
<head>Bottom</head>
<p>
Draw <a text>text</a> at the bottom of the screen.
<p>
<emph>Available as</emph>: menu item
</notex>

<node mformula, ytextpos, palettemenu, menus>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%mformula

<menuhead><head>formulae</head></menuhead>
<p>
Each escape time fractal has its own formula. XaoS supports the following
formulae:
<p>
<menuitems><center>
<p><a mandel>Mandelbrot</a>
<p><a mandel3>Mandelbrot^3</a>
<notex>
<p><a mandel4>Mandelbrot^4</a>
<p><a mandel5>Mandelbrot^5</a>
<p><a mandel6>Mandelbrot^6</a>
</notex>
<p><a octal>Octal</a>
<p><a newton>Newton</a>
<p><a barnsley>Barnsley1</a>
<p><a phoenix>Phoenix</a>
<p><a magnet>Magnet</a>
</center></menuitems>
<node mandel, , mandel3, mformula>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%mandel
<head>Mandelbrot</head>
<p>
The Mandelbrot set is the most famous escape time fractal ever. It has the
simple formula <math>z=z^2+c</math>. See the <tutor mset.xaf>tutorial chapter</tutor>.
<p>
<emph>Available as</emph>: menu item, command line option

<node mandel3, mandel, octal, mformula>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%mandel3 mandel4 mandel5 mandel6
<head>Mandelbrot^3--Mandelbrot^6</head>
<p>
This fractal is a simple modification of the standard 
<a mandel>Mandelbrot set</a> formula, using <math>z=z^3+c</math> instead of
<math>z=z^2+c</math>. 
<p>
Other derivations of the Mandelbrot set (Mandelbrot^4 and so on) use even
higher powers. See the <tutor power.xaf>tutorial chapter</tutor>.
<p>
<emph>Available as</emph>: menu item, command line option
<node octal, mandel3, newton, mformula>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%octal
<head>Octal</head>
<p>
This is a less well-known fractal that Thomas discovered in Fractint.
It has an interesting shape when displayed in the alternative 
<a mplane>planes</a>. See the <tutor octo.xaf>tutorial chapter</tutor>.
<p>
<emph>Available as</emph>: menu item, command line option

<node newton, octal, barnsley, mformula>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%newton
<head>Newton</head>
<p>
This is Newton's approximation method for finding the roots of a polynomial. It
uses the polynomial <math>x^3=1</math> and counts the number of iterations needed
to reach the approximate value of the root. See the <tutor newton.xaf>tutorial chapter</tutor>.
<p>
This fractal doesn't have Julia sets, but XaoS is able to generate Julia-like
sets which are also very interesting (they are sometimes called ``Nova
formulae'').
<p>
<emph>Available as</emph>: menu item, command line option

<node barnsley, newton, phoenix, mformula>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%barnsley
<head>Barnsley1</head>
<p>
This is a formula by Michael Barnsley. It produces very nice crystalline Julia
sets. See the <tutor barnsley.xaf>tutorial chapter</tutor>.
<p>
<emph>Available as</emph>: menu item, command line option

<node phoenix, barnsley, magnet, mformula>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%phoenix
<head>Phoenix</head>
<p>
This formula produces very nice Julia sets.
See the <tutor phoenix.xaf>tutorial chapter</tutor>.
<p>
<emph>Available as</emph>: menu item, command line option

<node magnet, phoenix, , mformula>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%magnet
<head>Magnet</head>
<p>
This is a formula that comes from theoretical physics.
It is derived from the study of theoretical lattices in the context of magnetic
renormalization transformations.
See the <tutor phoenix.xaf>tutorial chapter</tutor>.
<p>
<emph>Available as</emph>: menu item, command line option

<node palettemenu, mformula, , menus>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%palettemenu

<menuhead><head>Palette</head></menuhead>
This menu contains functions to change the palette the fractal is displayed with.
<menuitems><center>
<p><a defpalette>Default palette</a>
<p><a randompalette>Random palette</a>
<p><a palette>Custom palette</a>
<p><a cycling>Color cycling</a>
<p><a shiftpalette>Shift palette</a>
</center></menuitems>
<node defpalette, , randompalette, palettemenu>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%defpalette
<head>Default palette</head>
<p><emph>Syntax</emph>:(defaultpalette number)
<p>
Create a default palette. In the scripting language, <tt>number</tt> specifies
how much the palette is shifted by.
<p>
Note that changing the palette in truecolor modes forces recalculation of
the whole screen. To avoid this, you can enable the
<a palettef>palette emulation filter</a> first.
<p>
<emph>Available as</emph>: menu item, command line option, command

<node randompalette, defpalette, palette, palettemenu>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%randompalette
<head>Random palette</head>
<p><emph>Syntax</emph>:(randompalette)
<p>
Create a random palette. XaoS will automatically pick one of its
palette-generation algorithms and create one.
<p>
Note that changing the palette in truecolor modes forces recalculation of
the whole screen. To avoid this, you can enable the
<a palettef>palette emulation filter</a> first.
<p>
<emph>Available as</emph>: menu item, command line option, command

<node palette, randompalette, cycling, palettemenu>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%palette
<head>Custom palette</head>
<p><emph>Syntax</emph>:(palette integer integer integer)
<p>
A custom palette lets you re-create some of the random palettes. The first value
specifies the algorithm, which should currently be one of the following:
<dl>
<dt>0
<dd>Default palette
<dt>1
<dd>Black to color gradient
<dt>2
<dd>Black to color to white gradient
<dt>3
<dd>Cubistic-like algorithm.
</dl>
The seed specifies a random seed for the palette; different seeds generate
different palettes. The last value is the amount by which the palette is shifted.
<p>
Note that changing the palette in the truecolor modes forces recalculation of
the whole screen. To avoid this, you can enable the
<a palettef>palette emulation filter</a> first.
<p>
<emph>Available as</emph>: menu item, command line option, command

<node cycling, palette, shiftpalette, palettemenu>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%cycling rcycling cyclingspeed
<head>Color cycling</head>
<p><emph>Syntax</emph>:(cycling bool)
<p>
Color cycling is an old and simple effect to animate fractals. The Mandelbrot
set looks particularly nice when color-cycled. On truecolor displays, color
cycling fails to initialize (since those displays don't have a palette).
You can enable <a palettef>palette emulation filter</a> to make it possible.
<p>
<emph>Available as</emph>: menu item, command line option, command
<p>
In the user interface, colors can also be cycled in the opposite direction
with the ``<emph>Reversed color cycling</emph>'' function.
<p>
To control the cycling speed, you coan use arrow keys or the 
``<emph>Color cycling speed</emph>'' function.
<p>
<emph>Available as</emph>: menu item
<p><emph>Syntax</emph>:(cyclingspeed integer)
<p>
The parameter specifies the number of skips per second. It can be negative to
cycle in the opposite direction.
<p>
<emph>Available as</emph>: menu item, command line option, command

<node shiftpalette, cycling, , palettemenu>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%shiftpalette fshift bshift
<head>Shift palette</head>
<p><emph>Syntax</emph>:(shiftpalette integer)
<p>
Shift palette by the specified number of cells. This can be used to tune the
palette's position on the fractal. You can also use the
<emph>Shift one forward</emph> and <emph>Shift one backward</emph> functions
for fine-tuning. Note that shifted and rotated palettes could look different on
different displays (because they may have different palette sizes).
<p>
Shifting the palette on truecolor displays causes a recalculation of the screen.
To avoid this, you could use <a palettef>palette emulation filter</a>.
<p>
<emph>Available as</emph>: menu item, command line option, command


%endmenus
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%gpl

<head>GNU GENERAL PUBLIC LICENSE</head>
<center>Version 2, June 1991<p>

 Copyright (C) 1989, 1991 Free Software Foundation, Inc.<br>
                          675 Mass Ave, Cambridge, MA 02139, USA<br>
 Everyone is permitted to copy and distribute verbatim copies
 of this license document, but changing it is not allowed.
</center>
<head>Preamble</head>

  The licenses for most software are designed to take away your
freedom to share and change it.  By contrast, the GNU General Public
License is intended to guarantee your freedom to share and change free
software--to make sure the software is free for all its users.  This
General Public License applies to most of the Free Software
Foundation's software and to any other program whose authors commit to
using it.  (Some other Free Software Foundation software is covered by
the GNU Library General Public License instead.)  You can apply it to
your programs, too.
<p>
  When we speak of free software, we are referring to freedom, not
price.  Our General Public Licenses are designed to make sure that you
have the freedom to distribute copies of free software (and charge for
this service if you wish), that you receive source code or can get it
if you want it, that you can change the software or use pieces of it
in new free programs; and that you know you can do these things.
<p>
  To protect your rights, we need to make restrictions that forbid
anyone to deny you these rights or to ask you to surrender the rights.
These restrictions translate to certain responsibilities for you if you
distribute copies of the software, or if you modify it.
<p>
  For example, if you distribute copies of such a program, whether
gratis or for a fee, you must give the recipients all the rights that
you have.  You must make sure that they, too, receive or can get the
source code.  And you must show them these terms so they know their
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<p>
  We protect your rights with two steps: (1) copyright the software, and
(2) offer you this license which gives you legal permission to copy,
distribute and/or modify the software.
<p>
  Also, for each author's protection and ours, we want to make certain
that everyone understands that there is no warranty for this free
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want its recipients to know that what they have is not the original, so
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<p>
  Finally, any free program is threatened constantly by software
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<p>
  The precise terms and conditions for copying, distribution and
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<head>GNU GENERAL PUBLIC LICENSE<p>TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION</head>

  0. This License applies to any program or other work which contains
a notice placed by the copyright holder saying it may be distributed
under the terms of this General Public License.  The "Program", below,
refers to any such program or work, and a "work based on the Program"
means either the Program or any derivative work under copyright law:
that is to say, a work containing the Program or a portion of it,
either verbatim or with modifications and/or translated into another
language.  (Hereinafter, translation is included without limitation in
the term "modification".)  Each licensee is addressed as "you".
<p>
Activities other than copying, distribution and modification are not
covered by this License; they are outside its scope.  The act of
running the Program is not restricted, and the output from the Program
is covered only if its contents constitute a work based on the
Program (independent of having been made by running the Program).
Whether that is true depends on what the Program does.
<p>
  1. You may copy and distribute verbatim copies of the Program's
source code as you receive it, in any medium, provided that you
conspicuously and appropriately publish on each copy an appropriate
copyright notice and disclaimer of warranty; keep intact all the
notices that refer to this License and to the absence of any warranty;
and give any other recipients of the Program a copy of this License
along with the Program.
<p>
You may charge a fee for the physical act of transferring a copy, and
you may at your option offer warranty protection in exchange for a fee.
<p>
  2. You may modify your copy or copies of the Program or any portion
of it, thus forming a work based on the Program, and copy and
distribute such modifications or work under the terms of Section 1
above, provided that you also meet all of these conditions:
<dl>
<dt>
<dd>
<p>
a)
    You must cause the modified files to carry prominent notices
    stating that you changed the files and the date of any change.
<p>
b)
    You must cause any work that you distribute or publish, that in
    whole or in part contains or is derived from the Program or any
    part thereof, to be licensed as a whole at no charge to all third
    parties under the terms of this License.
<p>
c)
 If the modified program normally reads commands interactively
    when run, you must cause it, when started running for such
    interactive use in the most ordinary way, to print or display an
    announcement including an appropriate copyright notice and a
    notice that there is no warranty (or else, saying that you provide
    a warranty) and that users may redistribute the program under
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    the Program is not required to print an announcement.)
</dl>
<p>
These requirements apply to the modified work as a whole.  If
identifiable sections of that work are not derived from the Program,
and can be reasonably considered independent and separate works in
themselves, then this License, and its terms, do not apply to those
sections when you distribute them as separate works.  But when you
distribute the same sections as part of a whole which is a work based
on the Program, the distribution of the whole must be on the terms of
this License, whose permissions for other licensees extend to the
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<p>
Thus, it is not the intent of this section to claim rights or contest
your rights to work written entirely by you; rather, the intent is to
exercise the right to control the distribution of derivative or
collective works based on the Program.
<p>
In addition, mere aggregation of another work not based on the Program
with the Program (or with a work based on the Program) on a volume of
a storage or distribution medium does not bring the other work under
the scope of this License.
<p>
  3. You may copy and distribute the Program (or a work based on it,
under Section 2) in object code or executable form under the terms of
Sections 1 and 2 above provided that you also do one of the following:
<dl>
<dt>
<dd>
<p>
a)
    Accompany it with the complete corresponding machine-readable
    source code, which must be distributed under the terms of Sections
    1 and 2 above on a medium customarily used for software interchange; or,
<p>
b)
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    years, to give any third party, for a charge no more than your
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    customarily used for software interchange; or,
<p>
b)
    Accompany it with the information you received as to the offer
    to distribute corresponding source code.  (This alternative is
    allowed only for noncommercial distribution and only if you
    received the program in object code or executable form with such
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<p>
</dl>
The source code for a work means the preferred form of the work for
making modifications to it.  For an executable work, complete source
code means all the source code for all modules it contains, plus any
associated interface definition files, plus the scripts used to
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<p>
If distribution of executable or object code is made by offering
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distribution of the source code, even though third parties are not
compelled to copy the source along with the object code.
<p>
  4. You may not copy, modify, sublicense, or distribute the Program
except as expressly provided under this License.  Any attempt
otherwise to copy, modify, sublicense or distribute the Program is
void, and will automatically terminate your rights under this License.
However, parties who have received copies, or rights, from you under
this License will not have their licenses terminated so long as such
parties remain in full compliance.

<p>
  5. You are not required to accept this License, since you have not
signed it.  However, nothing else grants you permission to modify or
distribute the Program or its derivative works.  These actions are
prohibited by law if you do not accept this License.  Therefore, by
modifying or distributing the Program (or any work based on the
Program), you indicate your acceptance of this License to do so, and
all its terms and conditions for copying, distributing or modifying
the Program or works based on it.

<p>
  6. Each time you redistribute the Program (or any work based on the
Program), the recipient automatically receives a license from the
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restrictions on the recipients' exercise of the rights granted herein.
You are not responsible for enforcing compliance by third parties to
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<p>
  7. If, as a consequence of a court judgment or allegation of patent
infringement or for any other reason (not limited to patent issues),
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license would not permit royalty-free redistribution of the Program by
all those who receive copies directly or indirectly through you, then
the only way you could satisfy both it and this License would be to
refrain entirely from distribution of the Program.
<p>

If any portion of this section is held invalid or unenforceable under
any particular circumstance, the balance of the section is intended to
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<p>

It is not the purpose of this section to induce you to infringe any
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<p>

This section is intended to make thoroughly clear what is believed to
be a consequence of the rest of this License.
<p>
  8. If the distribution and/or use of the Program is restricted in
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<p>
  9. The Free Software Foundation may publish revised and/or new versions
of the General Public License from time to time.  Such new versions will
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<p>
Each version is given a distinguishing version number.  If the Program
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Foundation.
<p>
  10. If you wish to incorporate parts of the Program into other free
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<head>NO WARRANTY</head>

  11. BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY
FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW.  EXCEPT WHEN
OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES
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<p>
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<p>
<center>END OF TERMS AND CONDITIONS</center>
<head>How to Apply These Terms to Your New Programs</head>
<p>
  If you develop a new program, and you want it to be of the greatest
possible use to the public, the best way to achieve this is to make it
free software which everyone can redistribute and change under these terms.
<p>
  To do so, attach the following notices to the program.  It is safest
to attach them to the start of each source file to most effectively
convey the exclusion of warranty; and each file should have at least
the "copyright" line and a pointer to where the full notice is found.
<p>
<emph>
<tt>
    (one line to give the program's name and a brief idea of what it
    does.)<br>
    Copyright (C) 19yy  (name of author)
<p>
    This program 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.
<p>
    This program 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.
<p>
    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
</tt>
</emph>
<p>
Also add information on how to contact you by electronic and paper mail.
<p>
If the program is interactive, make it output a short notice like this
when it starts in an interactive mode:
<p>
<emph>
<tt>
    Gnomovision version 69, Copyright (C) 19yy name of author
    Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
    This is free software, and you are welcome to redistribute it
    under certain conditions; type `show c' for details.
</tt>
</emph>
<p>
The hypothetical commands `show w' and `show c' should show the appropriate
parts of the General Public License.  Of course, the commands you use may
be called something other than `show w' and `show c'; they could even be
mouse-clicks or menu items--whatever suits your program.
<p>
You should also get your employer (if you work as a programmer) or your
school, if any, to sign a "copyright disclaimer" for the program, if
necessary.  Here is a sample; alter the names:
<p>
<emph>
<tt>
  Yoyodyne, Inc., hereby disclaims all copyright interest in the program
  `Gnomovision' (which makes passes at compilers) written by James Hacker.
<p>
  (signature of Ty Coon), 1 April 1989
  Ty Coon, President of Vice
</tt>
</emph>
<p>
This General Public License does not permit incorporating your program into
proprietary programs.  If your program is a subroutine library, you may
consider it more useful to permit linking proprietary applications with the
library.  If this is what you want to do, use the GNU Library General
Public License instead of this License.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%end
