\input texinfo @c -*-texinfo-*- @c The original files are xaos.geninfo and xaos.hlp. xaos.texinfo is @c automatically generated. So make all changes in the orignal files please. @c To regenerate xaos.texinfo, please run "mktexinfo". @c Use A4 paper - If you don't like that, remove the following 3 lines. @iftex @afourpaper @end iftex @setfilename xaos.info @settitle An fast realtime interactive fractal zoomer --- user's manual @dircategory Graphics @direntry * XaoS: (xaos). A fast real-time interactive fractal zoomer @end direntry @ifinfo @copyright{} 1996-2008 Jan Hubicka and the XaoS Development Team Permission is granted to make and distribute verbatim copies of this manual provided the copyright notice and this permission notice are preserved on all copies. @end ifinfo @c %**end of header @set VERSION 3.4 @set DATE April 17, 2008 @titlepage @title{XaoS @value{VERSION}} @subtitle{A fast real-time interactive fractal zoomer --- User's manual} @author{Jan Hubi@v cka} @tex Dukelsk\'ych bojovn\'\i ku 1944 @end tex @* 390 03 T@'abor @* Czech Republic Email: @code{jh@@ucw.cz} @value{DATE} @page @vskip 0pt plus 1filll @vskip 0pt plus 1filll @copyright{} 1996-2008 @tex Jan Hubi\v cka and the XaoS Development Team @end tex Permission is granted to make and distribute verbatim copies of this manual provided the copyright notice and this permission notice are preserved on all copies. @end titlepage @c %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% @node Top, Overview, (dir), (dir) @ifinfo @top XaoS @value{VERSION} @flushright 1.0 A real-time interactive fractal zoomer User's manual @value{DATE} @end flushright This manual contains user documentation about XaoS --- a fast real-time fractal zoomer. XaoS uses a development model, so sources are freely available. The file @code{xaosdev.texinfo} in the source documentation contains a hacker's manual (design overview, algorithm description etc.). @end ifinfo @menu * Overview:: What does this software do then? * tutorial:: XaoS tutorial * controls:: Basic controls * video:: How to encode video files * format:: XaoS's file format description * writehelp:: How to write XaoS help files * xshl:: XaoS simple hypertext language * drivers:: Driver specific documentation * menus:: Functions, menu items and command line parameters * about:: Credits * support:: Getting Support * index:: Function index @end menu @c %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% @node Overview, tutorial, Top, Top @chapter Overview @menu * Why?:: Why yet another fractal generator? * What?:: What does this software do then? @end menu @node Why?, What?, Overview, Overview @section Why yet another fractal generator? We decided to make XaoS, because all fractal browsers we know of take a long time to calculate each image. You may browse nice images generated by them but real impressions of fractals --- the self similarity and infinite zooming into the nice parts of fractals --- can be seen only in animations. There are many programs available that make nice animations, but they take a long time to calculate and lots of space on disk. Most such animations are quite ugly because their authors can't see them without many hours of calculations. A natural question is: is it possible to generate such animations in real-time? The answer was negative for many years, since the Mandelbrot set is very computationally expensive. Things are changing. Today's computers are fast enough to calculate approx. 10.000 of pixels per frame, which is enough for a very low resolution animation (100x100). Several programs doing that are available. But 100x100 animation still looks quite ugly. To make animation nice you need at least 320x200 pixels. And that is 6 times more! One possibility is to wait until computers will be fast enough, but it will take many years, and then 320x200 animations will be obsolete and everyone will want 1024x768 resolution instead or more. We found a special algorithm that saves up to 99.98% of calculations during zooming by reusing pixels already calculated in previous frames. There were some programs doing similiar tricks before but we don't know about any able to do zooming interactively with a speed similar to XaoS. Many other tricks were later implemented XaoS to achieve yet higher framerates. Now XaoS does up to 120 frames per second on a 120Mhz pentium in a fullscreen 320x200 animation, and calculates an average of 160 (0.24%) pixels per frame. This makes XaoS fast enough to achieve its primary goal, realtime animation, but there are still many areas that could improve, since more complex fractals, higher resolutions, or slower computers still bring many problems. @c %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% @node What?, , Why?, Overview @comment node-name, next, previous, up @section What does this software do then? XaoS is a realtime interactive fractal zoomer. This means that it lets you zoom smoothly into any place in the fractal you choose without the many hours of calculation required by most other fractal generators. It now has many other features too, like 13 different fractal types, autopilot, special coloring modes, support for various bit depths (8bpp, truecolor, hicolor and realcolor), random palette generation, color cycling etc... @c %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% @node tutorial, controls, Overview, Top @chapter XaoS tutorial This is a brief introduction to the basic XaoS features. @section How to zoom 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} 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} (or @emph{left+right} buttons) you may also @emph{move the image} using ``drag & drop'' if you missed an interesting place. @emph{Unzooming} is also possible by using the @emph{right button}, but it is much slower because optimizations are not so effective as for zooming. In case you think that the default @emph{speed} is boring (it is quite slow, to make XaoS smooth on a slow computer) you may change it by pressing @emph{arrow up/down}. But faster zooming is more expensive, so if the speed is too high you will see little but funny colorful blinking rectangles. @section Autopilot To make XaoS yet more impressive we made a special autopilot that automatically drives into interesting boundaries of the set. So you can press @code{A}, 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. 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. @section Various fractal formulae XaoS also supports formulae other than the Mandelbrot set. You may change @emph{formula} using the @emph{number keys} or @emph{SHIFT+letters}. On keys @code{1} to @code{5} are @emph{Mandelbrot sets of various power}. The ``normal'' Mandelbrot set is on key @code{1}. On key @code{6} is a fractal called @emph{Newton}. It is Newton's famous formula for finding roots. On key @code{7} is the @emph{fourth ordered Newton} fractal. On key @code{8} is a fractal called @emph{Barnsley}. On key @code{9} is @emph{Barnsley's second} fractal. On key @code{0} is @emph{Barnsley's third} fractal. With keys @code{SHIFT-A} you can display a fractal called @emph{octo}. It is a fractal that Thomas discovered in fractint. With keys @code{SHIFT-B} you can display a fractal called @emph{Phoenix}. It is a very nice and quite famous fractal. With keys @code{SHIFT-C} you can display a fractal called @emph{Magnet}. This fractal has quite a complex formula so it is a bit slow. With keys @code{SHIFT-D} you can display the @emph{Magnet2} fractal. The rest of the built-in fractals are accessible through an other menu, but you can still use the hotkeys. On @code{SHIFT-E} is a fractal called @emph{Triceratops} found by Arpad. On @code{SHIFT-F} is a fractal called @emph{Catseye} found by Arpad. This is more interesting if you change the bailout value. On @code{SHIFT-G} is a fractal called @emph{Mandelbar}. It was in Gnofract4d, and they found it at: http://mathworld.wolfram.com/MandelbarSet.html On @code{SHIFT-H} is the @emph{Lambda} fractal. On @code{SHIFT-I} and @code{SHIFT-J} are the @emph{Manowar} and @emph{Spider} 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 The next 3 fractals are famous classic fractals. On @code{SHIFT-K} is the @emph{Sierpinski} Gasket. You can change its shape by selecting another Julia seed. (This is for technical reasons.) On @code{SHIFT-L} is the @emph{Sierpinski Carpet.} It's shape can also be changed by selecting another Julia seed. On @code{SHIFT-M} is the @emph{Koch Snowflake.} @section Out-coloring modes 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} or by pressing key @code{C} To see more about coloring modes, try the tutorial on Incoloring modes from the XaoS features overview. Those cryptic names for coloring modes are mathematical formulae, where @emph{iter} means number of iterations, @emph{real} means real coordinate of last orbit, and @emph{imag} means imaginary coordinate of last orbit. @section In-coloring mode 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} or by pressing @code{F}. You might also want to see the tutorial on Out-coloring modes from the XaoS features overview. @section Planes 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}, or by pressing @code{I}. Like the coloring modes, planes have cryptic names. You guessed it, they're mathematical formulae. Here @code{mu} means coordinates in the normal complex plane. If you have coordinates in @code{1/mu} 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. @table @strong @item mu normal mode. @item 1/mu Inversion: infinity goes to 0 and 0 goes to infinity. @item 1/(mu+0.25) Similar to inversion, but moves the center outside of the Mandelbrot set so that it looks parabolic. @item lambda Lambda plane. @item 1/lambda Inversion of lambda plane. @item 1/lambda-1 Inversion with moved center. @item 1/(mu-1.40115) A very interesting mode for the Mandelbrot set. It makes small things big, so you can browse the set's details easily. @end table @section Mandelbrot/Julia switching 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 Julia set from the Introduction to fractals. In the Mandelbrot mode, you can get a corresponding Julia by moving the mouse to an interesting point and pressing @code{M}. To get back press @code{M} again. Some fractals (Barnsley and phoenix) are already in their Julia versions, because the Mandelbrot ones are boring. But by pressing @code{M} in such fractal you should get the Mandelbrot version, and by choosing another point as the base point and pressing @code{M} 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. @section Fast Julia preview mode Fast Julia mode is a quick way to find a point to use as a base for the Julia set.. Just press @code{J} 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. @section Palette If you think that the default XaoS colors are ugly or you are just bored by them you can change it by pressing @code{P}. XaoS will automatically generate random palettes. Many of them look ugly, so press @code{P} again to get another one until you find one you like. @section Filters Many interesting effects are done by post-calculation filters. @xref{filter}. 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 @code{filter menu} or press @code{E}. @section Palette cycling This is a very old trick that makes the Mandelbrot set a little flashier. You may enable or disable it using @code{Y}. In the truecolor modes you need to enable the palette emulator filter first. This is done via the @code{E} key, or from the filter menu. @section Changing number of iterations 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: Press and hold @code{arrow right} and wait until iterations are high enough. This may slow down calculation much. To reduce number of iterations press @code{arrow left}. @section Changing resolution 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 @code{.gif} images, you may change the resolution. This can be done by pressing @code{=} in the full screen drivers, or simply by resizing the XaoS window. @section Changing driver 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. 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.. @section Other features 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} from the @emph{help menu}, to have an idea what XaoS can do. @c ## chapter tutorial ## @c %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% @comment node-name, next, previous, up @node controls, video, tutorial ,Top @chapter Basic controls By default the mouse buttons work in the following way: @table @strong @item left zoom in @item right zoom out @item middle move fractal in a drag-and-drop fashion @end table @emph{Note:} Since most Macs only have one button mice, these controls are emulated on Mac OS X using modifier keys. See the help section on Mac OS X for details. 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. If you don't have a middle button, press both buttons to enable emulation. 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. 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} and @emph{Right}. An @emph{Up} and @emph{Down} keys should be used to change zooming speed. Note that higher speed costs more and image will be blocky. This behavior can also change. With palette cycling enabled, @emph{Left} and @emph{Right} keys change cycling speed; in continuous rotation they change rotation speed. 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. @c ## chapter controls ## @c %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% @comment node-name, next, previous, up @node video, format, controls ,Top @chapter How to encode video files from XaoS To create a video, make and @code{xaf} file first (the easiest way to do this is to use the @emph{record} function in the file menu). Then you need to render the animation. XaoS can output sequences of ordinary @code{PNG} images, that can later be used by a video encoder. @section Generating image sequences for video To generate an image sequence, choose @emph{Render Animation} from the @emph{Misc} menu. You can also use the following command on the command line: @example xaos -render [filename] -size 352x240 -antialiasing -renderframerate 24 -basename [basename] @end example @emph{File to render} (@code{[filename]}) is the name of the @code{xaf} file, @emph{Basename} (@code{[basename]}) 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 @code{.png} extension to this name automatically. 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. The framerate can also be altered. Make sure you choose a framerate that is supported by the video codec you wish to use. @emph{Antialiasing} (@code{-antialiasing}) 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}) On the other hand, the other XaoS rendering option @emph{Always Recalculate} (@code{-alwaysrecalc}) (which disables XaoS's zooming optimizations) is @emph{not recommended}. 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. @section Rendered files 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). All images are named @code{[basename]framenum.png}. For example @code{intro0001.png} 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 @code{mv} or symbolic linking. A list of all filenames is saved into the file @code{[basename].par}, 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. @section Encoding videos 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: @table @strong @item ffmpeg Available from: @code{http://ffmpeg.mplayerhq.hu/} Instructions: @code{http://ffmpeg.mplayerhq.hu/faq.html#SEC12} @item mencoder Part of mplayer, available from: http://www.mplayerhq.hu/ Instructions: @code{http://www.mplayerhq.hu/DOCS/HTML/en/menc-feat-enc-images.html} @end table 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. Note: we used to recommend Berkeley parallel MPEG encoder to encode the generated png files into MPEG videos. We have kept the instructions mainly for historic purposes. @c ## chapter video ## @c %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% @comment node-name, next, previous, up @node format, writehelp,video ,Top @chapter XaoS's file format 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. 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. 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: @code{(command_name }@emph{[param1] [param2]}@code{)} where parameters are optional and separated by whitespace (an arbitrary number of spaces, tabs and newlines). The parameters can have the following types: @table @strong @item integer number w/o decimal point (@code{123}) @item float floating point number in decimal notation with optional exponent (@code{1.23E2}) @item keyword text started by quote @code{'}. It is used to pass various string constants like formula name (@code{'mandel}) Quote is required for scheme compatibility @item string Text inside double quotes. The only parameter that should contain whitespace @item boolean @code{#t} for true or @code{#f} for false @end table There is a complete description of all XaoS functions (with some examples) and an index of functions in the XaoS registry. @xref{menus}. You may particularly want to read about the animation functions. @xref{animf}. Also, the following functions are significant: @table @strong @item load This function loads and interprets a file. It works similarly to @code{#include} in C. @item initstate 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. @item usleep 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. @item wait 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. @end table Example: @example ;configure everything for the first frame (inistate) (palette 1 1163254293 0) ;custom palette (cycling #t) ;enable cycling (cyclingspeed 7) (maxiter 276) ;higher number of iterations (range 3) ;default range for solid guessing (usleep 1000000) ;second frame starts here (moveview -1.8101154154614007889 -8.2687205907162041209E-05) ;just move the image (usleep 1000000) ;third frame (morphview -1.8101154154614007889 -8.2687205907162041209E-05 6.277210971069452361E-10 6.2772109785334669875E-10) ;10 seconds of zooming into selected rectangle (usleep 100000000) @end example 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: @example (initstate) (defaultpalette 0) (formula 'mandel) (view -1.64128273713 -5.50393226816E-05 9.69332308848E-08 9.69332308834E-08) @end example Just change the @code{view} command to @code{morphview}, and add @code{usleep}: @example (initstate) (defaultpalette 0) (formula 'mandel) (morphview -1.64128273713 -5.50393226816E-05 9.69332308848E-08 9.69332308834E-08) (usleep 10000000) @end example The following code produces Julia morphing in the real axis: @example (initstate) (fastjulia #t) (juliaseed -2 0) (morphjulia 2 0) (usleep 2000000) @end example And following is the ``rotozooming'' animation: @example (initstate) (fastrotate #t) (morphview -1.64128273713 -5.50393226816E-05 9.69332308848E-08 9.69332308834E-08) (morphangle 300) (usleep 10000000) (wait) (fastrotate #f) @end example @chapter XaoS gallery 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 mailing list or upload them to our website. @c ## chapter format ## @c %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% @comment node-name, next, previous, up @node writehelp, xshl,format ,Top @chapter How to write XaoS help files XaoS help is stored in the file @code{help/xaos.hlp}. It is divided into parts, each part being started by a @emph{keyword}. In the help file keywords are written as @code{%keyword} 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. @c ## chapter writehelp ## @c %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% @comment node-name, next, previous, up @node xshl, drivers,writehelp ,Top @section xshl @emph{Xshl} stands for @emph{XaoS simple hypertext language}. 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 @code{src/util/xshl.c} to parse it. The following tags are supported: @table @strong @item head make headings (should be at the beginning of the page, at least) @item emph emphasize @item tt Use non proportional font @item br Break line @item p Next paragraph @item dl Definition list @item dt Definition tag (should be used only inside a definition list) @item dd Definition description (should be used only inside a definition list) @item center align to center @item right align to right @item red change color to red (should not be used in help files) @item black change color to black (should not be used in help files) @item white change color to white (should not be used in help files) @item a name link to other help page @item tutor name activate tutorial @item notex Ignore this in texinfo manuals @end table @c ## section xshl ## @c %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% @comment node-name, next, previous, up @node drivers, menus,xshl ,Top @chapter Platform-specific documentation 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. @c ## chapter drivers ## @menu * aa:: AA-lib --- high quality ascii art driver * BeOS:: BeOS drivers * DGA:: DGA driver * dos:: DOS driver * dX-fullscreen:: directX fullscreen driver * dX-window:: directX windowed driver * ggi:: GGI driver * plan9:: plan9 driver * SVGAlib:: SVGAlib driver * win32:: Win32 driver * X11:: X11 driver @end menu @c %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% @comment node-name, next, previous, up @node aa, BeOS , ,drivers @section AA-lib driver 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 @code{http://aa-project.sf.net}) It is a fully featured XaoS driver for text mode displays. It supports 256 colors and the mouse where possible. It also has some extended features available from the UI menu: @table @strong @item Attributes 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. @item Font 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. @item Inversion Some devices use inverse video: use this to get correct results on such devices. @item Dithering mode 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. @item Palette options 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}. @item Save text screen 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}. @end table 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 @code{xaos -help} or the AA-lib documentation for details. The AA driver was written by Jan Hubicka, 1997. @c ## section aa ## @c %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% @comment node-name, next, previous, up @node BeOS, DGA , aa ,drivers @section BeOS support 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. The first version of the BeOS driver was written by Jens Kilian and later extended by Jan Hubicka. @subsection Installation You can start the installation script to do everything for you. If you want something special, read this section. In order for XaoS to work you need to keep the executable together with its data files (@code{help}, @code{examples}, @code{catalogs} and the @code{tutorials} directory) When first started, XaoS registers two new mime types called @code{image/x-xaos-position} for XaoS Position Files and @code{video/x-xaos-animation} for XaoS Animation Files, registers icons for them and sets itself as default application. @subsection Available display drivers XaoS supports following drivers: @table @strong @item BeOS Standard windowed driver using application server @item DirectWindow Driver done using Game Kit's direct window class @item WindowScreen Fullscreen driver. @end table 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. 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. 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 @code{-driver WindowScreen} command line option. 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. @subsection XaoS as translator 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. Note that @emph{translation can take a while}. So be patient and wait for the result. If the translator doesn't work, ensure that you have a link to the XaoS executable in @code{/boot/beos/system/add-ons/Translators/}. @c ## section BeOS ## @c %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% @comment node-name, next, previous, up @node DGA, dos , BeOS ,drivers @section DGA driver This is the driver for DGA (Direct Graphics Architecture) extension used by XFree86 X servers. It is pretty new so it could be buggy. Bugs/limitations: @table @strong @item In 8bpp mode, XaoS has problems with the palette with certain window managers I don't know why this happens. Just let me know what's wrong, or use another window manager. @item Banked modes are not supported. I don't have any card to test this with, so it doesn't work in the current version. @end table DGA driver was written by Jan Hubicka, 1999. @c ## section DGA ## @c %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% @comment node-name, next, previous, up @node dos, dX-fullscreen , DGA ,drivers @section DOS driver 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. The following problems may occur: @table @strong @item Some DPMI servers may cause problems Some DPMI servers like the one from Novell/Dr/Open DOS are buggy. Use clean DOS instead and XaoS will automatically start @code{cwsdpmi}. Under Open Dr DOS use @code{dpmi off} at command line to disable it. @item Higher resolutions don't work 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.) @item XaoS needs a coprocessor 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. @item XaoS needs mouse driver to be usable @item XaoS works slowly in higher resolution 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 @code{http://www.talula.demon.co.uk} for the FreeBE project or Scitech Display Doctor package. (See the note about VESA at the end of this section.) @end table @subsection VESA 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. 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 @code{ftp.simtel.net}, where there are many VESA emulation packages such as @code{s3vbe} or the new FreeBe project at @code{http://www.talula.demon.co.uk} DOS driver was written by Jan Hubicka, 1997. @c ## section dos ## @c %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% @comment node-name, next, previous, up @node dX-fullscreen, dX-window , dos ,drivers @section DirectX fullscreen driver 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. 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 @code{=} key (or by using the UI/Resize menu). If the selected mode is not supported, the driver will restore the previous setting. Use the @code{-mode WIDTHxHEIGHTxDEPTH} (like @code{-mode 640x480x16}) command line option to change graphics mode. If you want to start XaoS in DirectX, use the @code{-driver dX-fullscreen} option. See the Win32 driver documentation for some more Windows releated information. DirectX driver was written by Jan Hubicka, Jan Olderdissen and Pavel Tzekov, 1999. @c ## section dX-fullscreen ## @c %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% @comment node-name, next, previous, up @node dX-window, ggi , dX-fullscreen ,drivers @c ## section DX-window ## @c %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% @comment node-name, next, previous, up @node ggi, plan9, dX-window ,drivers @section GGI driver 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. Everything else might work well, but there are no guarantees. It is alpha quality software. GGI driver was written by Jan Hubicka, 1998. @c ## section ggi ## @c %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% @comment node-name, next, previous, up @node plan9, SVGAlib, ggi ,drivers @section Plan9 driver 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) 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. 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 @code{-pixelwidth} and @code{-pixelheight} instead of @code{-screenwidth} and @code{-screenheight}. By default XaoS changes the colormap. This will collide with other colorful programs like Mortha. You can disable this behavior using @code{-nopalette} switch, but this will slow down XaoS. Plan9 driver was written by Jan Hubicka, 1997. @c ## section plan9 ## @c %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% @comment node-name, next, previous, up @node SVGAlib, win32, plan9 ,drivers @section SVGAlib driver 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: @table @strong @item XaoS doesn't initialize graphics mode 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 (@code{chmod +s}) at XaoS executable. note that I take care to disable all security holes caused by this bit so I believe it is safe. @item Mouse doesn't work @item Screen is blank at higher resolutions Both this problems are probably caused by misconfiguration of SVGAlib. Please configure it in @code{etc/vga/libvga.cong} or @code{/usr/local/lib/libvga.conf} GPM can also cause problems. Try to kill it before starting XaoS. @item When I switch console I can't switch back This is another typical SVGAlib bug. Try to hold @code{F} key longer than @code{alt}. 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. @end table SVGAlib driver was written by Jan Hubicka, 1997. @c ## section SVGAlib ## @c %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% @comment node-name, next, previous, up @node win32, X11, SVGAlib ,drivers @section Win32 driver 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. 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. Use @code{-size WIDTHxHEIGHT} command line option to change the default window size. 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. 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 @code{doc/cmdopts.txt}. 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. Note that XaoS also supports the DirectX API. Win32 driver was written by Jan Hubicka, Jan Olderdissen and Pavel Tzekov, 1999. @c ## section win32 ## @c %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% @comment node-name, next, previous, up @node X11, , win32 ,drivers @section X11 driver This was the first driver done for XaoS. It supports many visuals, shared colormaps and MitSHM extension. Bugs/limitations: @table @strong @item XaoS makes some X servers too busy 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 @code{-sync} to avoid this problem. Note that @code{-sync} does @code{not} make all communication with X asynchronous; it just adds one additional XSync call. So the slowdown is not as large as you might expect. @item Does not work on all visuals This driver supports only 8bpp pseudocolor/grayscales, 15,16,24 and 32bpp truecolor, 1bpp and 8bpp staticolor visuals. @item Palette rotating does not work for 8bpp pseudocolor w/o private palette @end table X11 driver was written by Jan Hubicka and Thomas Marsh, 1997. @c ## section X11 ## @c %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% @comment node-name, next, previous, up @node menus, about, drivers,Top @appendix Menus, functions and command line parameters 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. @menu * root:: Root menu * animroot:: Animation root menu * plc:: Replay only commands * linemenu:: Line drawing functions * animf:: Animation functions * time:: Timing functions * file:: File * edit:: Edit * fractal:: Fractal * calc:: Calculation * mfilter:: Filters * ui:: UI * misc:: Misc * helpmenu:: Help * xtextpos:: Horizontal text position * ytextpos:: Vertical text position * mformula:: Formulae * palettemenu:: Palette @end menu @node root, animroot, , menus @node animroot, plc, root, menus @appendixsec Animation root menu This menu is displayed at the top of the screen when animation replay is active. @menu * file:: File * stopreplay:: Stop replay * helpmenu:: Help * ui:: UI @end menu @node stopreplay, , , animroot @appendixsubsec Stop replay Terminate animation replay. @emph{Available as}: menu item @node plc, linemenu, animroot, menus @appendixsec Replay only commands Some commands, such as timing primitives or animation functions, are available only in animation files. @menu * linemenu:: Line drawing functions * animf:: Animation functions * time:: Timing functions * load:: Include file @end menu @node load, , , plc @appendixsubsec Include file @defun load file @end defun This function lets you include another file in your script. It works similarly to @code{#include} in C or @code{load} in Scheme. The file is searched for in the same directory as the current source file. @emph{Available as}: command @node linemenu, animf, plc, menus @appendixsec Line drawing functions 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 ``Introduction to fractals'' for examples of this feature. Lines can be drawn in @emph{screen} coordinates, where 0,0 is the top left corner and 1,1 is bottom right, @emph{scaled} coordinates, which are similar, but scaled to keep 0,0---1,1 rectangular, or @emph{Fractal} coordinates, to draw a line at an exact position on the screen. The color of the line should be specified by the @code{color} 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 @code{linekey}. Commands for changing lines operate on the line with the current key. (Lines drawn in sequence have consecutive numbers.) For example: @example (color 'red) (line 'scaled 0.3 0.5 0.7 0.5) (line 'scaled 0.3 0.5 0.7 0.5) (line 'scaled 0.3 0.5 0.3 0.5) (line 'scaled 0.7 0.5 0.7 0.5) (linekey 0) (morphline 'scaled 0.3 0.3 0.7 0.3) (morphline 'scaled 0.3 0.7 0.7 0.7) (morphline 'scaled 0.3 0.3 0.3 0.7) (morphline 'scaled 0.7 0.3 0.7 0.7) (usleep 1000000) @end example Creates line morphing to rectangle. @defun line keyword complex complex @end defun Draw line between two points. @code{keyword} specifies type of coordinates and should be one of the following: @code{`fractal}, @code{`screen} or @code{`scaled}. This function also increases the line key. @emph{Available as}: command @defun morphline keyword complex complex @end defun Morph current line to given coordinates. @code{keyword} specifies type of coordinates and should be one of the following: @code{`fractal}, @code{`screen} or @code{`scaled}. The line will start moving at the next timing command, and reach the final position before the end of it. This function also increases the line key. @emph{Available as}: command @defun morphlastline keyword complex complex @end defun This function has the same functionality as morphline, 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 linekey back. @emph{Available as}: command @defun linekey integer @end defun Set current line key. @emph{Available as}: command @defun clearline @end defun Clear current line. This function also increases the line key. @emph{Available as}: command @defun clearlines @end defun Clear all displayed lines. Lines can also be cleared using the @code{clearscreen} or @code{display} commands available from the Misc menu. @xref{misc}. @emph{Available as}: command @node animf, time, linemenu, menus @appendixsec Animation functions 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 timing function. @xref{time}. For example: @example (view 0 0 1 1) (morphview 0 0 2 2) (usleep 5000000) @end example Will do a 5 second long unzooming animation. @menu * animateview:: Animate view * smoothmorph:: Smooth morphing * morphview:: Morph view * morphjulia:: Morph julia * moveview:: Move view * morphangle:: Morph angle * zoom:: Zooming functions @end menu @node animateview, smoothmorph, , animf @appendixsubsec Animate view @defun animateview float float float float @end defun This function is almost identical to function @code{view}. @xref{uiview}. It expects that the view will be changed only slightly, so recalculation is done with @code{ANIMATE} priority. This means that dynamic resolution is used by default. Viewport is selected by the center and two radiuses (real and imaginary). See @code{view} for more information. @emph{Available as}: command @node smoothmorph, morphview, animateview, animf @appendixsubsec Smooth Morphing @defun morphview keystring starttime endtime @end defun 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. The keystring is used to select what morphing you want to control. It is one of the following: @table @strong @item 'view control morphview @item 'angle control morphangle @item 'julia control morphjulia @item 'line control morphline @end table @node morphview, morphjulia, smoothmorph, animf @appendixsubsec Morph view @defun morphview float float float float @end defun For the time selected by the next @code{usleep} or other timing function, the viewpoint is smoothly morphed from the current one to that selected by @code{morphview}. Viewport is selected by the center and two radiuses (real and imaginary). See @code{view} for more information. This function can easily be used for creating zooming/unzooming animations using position files. This is an example position file generated by XaoS: @example (initstate) (defaultpalette 0) (formula 'mandel) (view -1.64128273713 -5.50393226816E-05 9.69332308848E-08 9.69332308834E-08) @end example By replacing the @code{view} command with @code{morphview} and adding @code{usleep} you can create a zooming animation: @example (initstate) (defaultpalette 0) (formula 'mandel) (morphview -1.64128273713 -5.50393226816E-05 9.69332308848E-08 9.69332308834E-08) (usleep 10000000) @end example @emph{Available as}: command @node morphjulia, moveview, morphview, animf @appendixsubsec Morph Julia @defun morphjulia complex @end defun For the time selected by the next @code{usleep} or other timing function, the Julia seed is smoothly interpolated from the current one to that selected by @code{morphjulia}. By default this will cause recalculation of the whole screen. To avoid this, use fast Julia mode. @xref{fastjulia}. A simple animation morphing Julia seed in the X axis: @example (initstate) (fastjulia #t) (juliaseed -2 0) (morphjulia 2 0) (usleep 2000000) @end example @emph{Available as}: command @node moveview, morphangle, morphjulia, animf @appendixsubsec Move view @defun moveview complex @end defun Smoothly move the image center to another position. @emph{Available as}: command @node morphangle, zoom, moveview, animf @appendixsubsec Morph angle @defun morphangle float @end defun Smoothly rotate the image to another angle. By default rotation causes recalculation of the whole screen. To avoid this you need to enable fast rotate mode. @xref{rotate}. Don't forget to disable it later, since it slows down other animations. A simple ``rotozooming'' animation: @example (initstate) (fastrotate #t) (morphview -1.64128273713 -5.50393226816E-05 9.69332308848E-08 9.69332308834E-08) (morphangle 300) (usleep 10000000) (wait) (fastrotate #f) @end example @emph{Available as}: command @node zoom, , morphangle, animf @appendixsubsec Zooming functions The functions for zooming/unzooming were created mainly for recording animations. In manually created animation files, it is easier to use @code{morphview}. @xref{morphview}. @defun zoomcenter complex @end defun This function sets the center to zoom in on. The center is given as a position in fractal coordinates. @emph{Available as}: command @defun zoom @end defun Start zooming to the area specified by @code{zoomcenter}. The speed of zooming should be controlled by the function @code{speed} or in a more exact way by @code{maxstep} and @code{speedup}. @defun unzoom @end defun Start unzooming from the area specified by @code{zoomcenter}. @emph{Available as}: command @defun stop @end defun Stop zooming or unzooming. @emph{Available as}: command @node time, file, animf, menus @appendixsec Timing functions 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. @menu * usleep:: Usleep * textsleep:: Wait for text * wait:: Wait for complete image @end menu @node usleep, textsleep, , time @appendixsubsec Usleep @defun usleep integer @end defun 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. @emph{Available as}: command @node textsleep, wait, usleep, time @appendixsubsec Wait for text @defun textsleep @end defun This function's behavior is very similar to @code{usleep}, 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 @code{letterspersec}. @xref{letterspersec}. This value can be changed during replay with the arrow keys. @emph{Available as}: command @node wait, , textsleep, time @appendixsubsec Wait for complete image @defun wait @end defun 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 motion blur. @xref{blur}. This function deadlocks if used with animation functions; don't do that. @emph{Available as}: command @node file, edit, time, menus @appendixsec File @menu * loadpos:: Load * savepos:: Save * record:: Record * play:: Replay * saveimg:: Save image * loadexample:: Load random example * savecfg:: Save configuration * quit:: Quit @end menu @node loadpos, savepos, , file @appendixsubsec Load XaoS position file Load a XaoS position file (@code{*.xpf}). See the format description for more information. @emph{Available as}: menu item, command line option @node savepos, record, loadpos, file @appendixsubsec Save XaoS position file @defun savepos file @end defun Save current state to a XaoS position file (@code{*.xpf}). This file is human-readable, and can easily be improved by hand after saving, or used as a base for animations. See the format description for more information. @emph{Available as}: menu item, command line option, command @node record, play, savepos, file @appendixsubsec Record animation @defun record bool [ file ] @end defun e Toggle recording to a XaoS animation file (@code{*.xaf}). This file is human-readable, and can easily be improved by hand after recording. See the format description for more information. From the scripting language, @code{(record #t)} enables recording, and @code{(record #f)} disables it. @emph{Available as}: menu item, command line option, command @node play, saveimg, record, file @appendixsubsec Replay animation Replay a XaoS animation file (@code{.xaf}). @emph{Available as}: menu item, command line option @node saveimg, loadexample, play, file @appendixsubsec Save image @defun saveimg file @end defun Save current state to an image file. This file is in @code{.png} (portable network graphics) format, which can be read by many applications varying from graphics programs all the way to Web browsers. This function needs an external library called @code{libpng}. If the library wasn't available during compilation, this function is unavailable too. Please see @code{INSTALL} for more information about obtaining libpng and recompiling XaoS. @emph{Available as}: menu item, command line option, command @node loadexample, savecfg, saveimg, file @appendixsubsec Load random example @defun loadexample @end defun Choose random @code{.xpf} file from the @code{examples} directory and load it. You might use it as the starting point for next exploration. @emph{Available as}: menu item, command line option, command @node savecfg, quit, loadexample, file @appendixsubsec Save configuration @defun savecfg @end defun Save current configuration to @code{~/.xaosrc} (under Unix) or @code{xaos.cfg} (under DOS and Windows). XaoS automatically reloads the configuration from this file when it starts. @emph{Available as}: menu item, command line option, command @node quit, , savecfg, file @appendixsubsec Quit @defun quit @end defun Quit XaoS. @emph{Available as}: menu item, command line option, command @node edit, fractal, file, menus @appendixsec Edit A fairly ordinary Edit menu. @menu * undo:: Undo * redo:: Redo * copy:: Copy * paste:: Paste @end menu @node undo, redo, , edit @appendixsubsec Undo 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. @emph{Available as}: menu item @node redo, copy, undo, edit @appendixsubsec Redo Redo last undone operation. See undo. @xref{undo}. @emph{Available as}: menu item @node copy, paste, redo, edit @appendixsubsec Copy 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). @emph{Available as}: menu item @node paste, , copy, edit @appendixsubsec Paste 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). @emph{Available as}: menu item @node fractal, calc, edit, menus @appendixsec Fractal 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. @menu * formula:: Formula * mformula:: formulae * incoloring:: Incoloring mode * outcoloring:: Outcoloring mode * plane:: Plane * palettemenu:: Palette * uimandelbrot:: Mandelbrot mode * uiperturbation:: Perturbation * uiview:: View * initstate:: Reset to defaults * tcolor:: True-color coloring modes @end menu @node formula, uimandelbrot, , fractal @appendixsubsec Formula @defun formula keyword @end defun Set the current fractal formula. @code{keyword} should be one of the following: @table @strong @item 'mandel Standard Mandelbrot set. @xref{mandel}. @item 'mandel3 Mandelbrot set, power 3. @xref{mandel3}. @item 'mandel4 Mandelbrot set, power 4. @item 'mandel5 Mandelbrot set, power 5. @item 'mandel6 Mandelbrot set, power 6. @item 'newton Newton's approximation method. @xref{newton}. @item 'barnsley First Barnsley's formula. @xref{barnsley}. @item 'octo Fractint's octo. @xref{octal}. @item 'phoenix Phoenix. @xref{phoenix}. @item 'magnet Magnet. @xref{magnet}. @end table @emph{Available as}: command @node uimandelbrot, uiperturbation, formula, fractal @appendixsubsec Mandelbrot/Julia mode 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 Julia set. 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. 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 @code{M} key instead of using the menu, the current mouse position is used. 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 Fast Julia mode. @xref{fastjulia}. 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. @emph{Available as}: menu item @defun julia bool @end defun This function is used to enable/disable julia mode in animation files. @emph{Available as}: command line option, command @defun juliaseed complex @end defun Select the current julia seed. @emph{Available as}: command line option, command @node uiperturbation, uiview, uimandelbrot, fractal @appendixsubsec Perturbation 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. 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. It can be used to specify a complex number representing a point on the screen. If you hit the @code{B} key instead of using the menu, the current mouse position is used. This too is a toggle, so @code{B} again will disable perturbation by setting it to zero. This function only has an effect for certain formulae (like the Mandelbrot set) and only then in Mandelbrot mode. @xref{mandel}. @emph{Available as}: menu item @defun perturbation complex @end defun 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. @emph{Available as}: command line option, command @node bailout, fastjulia, maxiter, calc @appendixsubsec Bailout 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. For the Mandelbrot set 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. Other fractal types may use other bailout values. The default is 4 for each types. @emph{Available as}: menu item, command line option, command @defun bailout float @end defun @node uiview, initstate, uiperturbation, fractal @appendixsubsec View 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. In the dialog you will be asked for the @emph{center}, @emph{radius} and @emph{angle} of the image. 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. 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{y1}, @math{x2}, @math{y2}. To set the same viewpoint in XaoS, set the real portion of the center to @math{(x1+x2)/2}, the imaginary part of center to @math{(y1+y2)/2}, and the radius to the greater of @math{x2-x1} and @math{y2-y1}. Other programs use a zoom factor instead of a radius. For these, you can set the radius to @math{2/zoom}. @emph{Available as}: menu item @defun view float float float float @end defun 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 @code{angle}), 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. @emph{Available as}: command line option, command @defun angle float @end defun Set the rotation angle in degrees. By default this causes recalculation of the screen. You can enable the fast rotation mode, which lets you rotate the screen without recalculation; but it slows down other things, so don't forget to disable it later. @emph{Available as}: command line option, command @node initstate, plane, uiview, fractal @appendixsubsec Reset to defaults @defun initstate @end defun 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. @emph{Available as}: menu item, command line option, command @node plane, incoloring, initstate, fractal @appendixsubsec Plane @defun plane integer @end defun All fractals displayed by XaoS are functions with a complex parameter. They can be be displayed in the normal complex plane where the @code{x} coordinate is the real part of the number and the @code{y} is imaginary; but they can also be displayed differently: @table @strong @item @math{mu} Normal complex plane (default) @item @math{1/mu} Inversion---infinity is at 0 and 0 is at infinity. @item @math{1/(mu+0.25)} Similar to inversion, but moves the center outside the Mandelbrot set, so it looks parabolic. @item @math{lambda plane}, @math{1/lambda}, @math{1/lambda-1} Lambda plane and its inversion, and with a different center. @item @math{1/(mu-1.40115)} A very interesting mode for the Mandelbrot set, this makes small things large, for easier browsing of the set's details. @end table The tutorial about planes has some examples. In the scripting language, the planes are numbered as follows: @table @strong @item 0 @math{mu} @item 1 @math{1/mu} @item 2 @math{1/(mu+0.25)} @item 3 @math{lambda} @item 4 @math{1/lambda} @item 5 @math{1/(lambda-1)} @item 6 @math{1/(mu-1.40115)} @end table @emph{Available as}: command line option, command @node incoloring, outcoloring, plane, fractal @appendixsubsec Inside coloring mode @defun incoloring integer @end defun 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. The tutorial on incoloring has more information and examples. XaoS has many different ways to show that value. The cryptic names of the modes are mathematical formulae, where @emph{real} means the real part of the latest orbit, and @emph{imag} means the imaginary part. @emph{zmag} uses the magnitude of the value. The @emph{Decomposition-like} method uses the angle of the orbit. Also, truecolor 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: @table @strong @item 0 @math{0} (default) @item 1 @math{zmag} @item 2 Decomposition-like @item 3 @math{real/imag} @item 4 @math{abs(abs(c)-abs(r))} @item 5 @math{cos(mag)} @item 6 @math{mag*cos(real^2)} @item 7 @math{sin(real^2-imag^2)} @item 8 @math{atan(real*imag*creal*cimag)} @item 9 squares @item 10 Truecolor. To set exact parameters for truecolor coloring use the @code{tcolor} command. @end table @emph{Available as}: command line option, command @node outcoloring, tcolor, incoloring, fractal @appendixsubsec Outside coloring mode @defun outcoloring integer @end defun Outcoloring modes are similar to incoloring modes, 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. The tutorial on outcoloring has more information and examples. The cryptic names of the modes are mathematical formulae, where @emph{iter} means the number of iterations required for the value to become recognisably divergent, @emph{real} means the real part of the latest orbit, and @emph{imag} means the imaginary part. @emph{binary decomposition} uses a different color when the imaginary part of the orbit is lower than zero, and @emph{smooth} attempts to remove stripes and discontinuities. Also, truecolor 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). In the scripting language, the outcoloring mode is specified by one of the following integers: @table @strong @item 0 @math{iter} (default) @item 1 @math{iter+real} @item 2 @math{iter+imag} @item 3 @math{iter+real/imag} @item 4 @math{iter+real+imag+real/imag} @item 5 binary decomposition @item 6 biomorphs @item 7 potential @item 8 color decomposition @item 9 smooth @item 10 True-color outcoloring mode. To set exact parameters for truecolor coloring use @code{outtcoloring}. @xref{tcolor}. @end table @emph{Available as}: command line option, command @node tcolor, , outcoloring, fractal @appendixsubsec Truecolor coloring mode @defun intcoloring integer @end defun @defun outtcoloring integer @end defun Truecolor coloring modes are similar to incolor and outcolor 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 palette emulator filter first to see anything, amd the quality won't be so good, as far fewer colors are available per parameter. The tutorial on truecolor coloring modes has more information and examples. The cryptic names of the modes are always three mathematical formulae (one for each color component), where @emph{real} means the real part of the latest orbit, and @emph{imag} means the imaginary part. To enable inside/outside truecolor coloring mode in the scripting language, set @code{incoloring}/@code{outcoloring} value to 10 (truecolor coloring mode) before (or after) calling @code{intcoloring} or @code{outtcoloring}. In the scripting language, the coloring mode is specified by one of the following integers: @table @strong @item 0 black @item 1 @math{re*im} @math{sin(re^2)} angle @item 2 @math{sin(re)} @math{sin(im)} @math{sin(square)} @item 3 hsv @item 4 hsv2 @item 5 @math{cos(re^c)} @math{cos(im^2)} @math{cos(square)} @item 6 @math{abs(re^2)} @math{abs(im^2)} @math{abs(square)} @item 7 @math{re*im} @math{re*re} @math{im*im} @item 8 @math{abs(im*cim)} @math{abs(re*cre)} @math{abs(re*cim)} @item 9 @math{abs(re*im-csqr)} @math{abs(re^2-csqr)} @math{abs(im^2-csqr)} @end table @emph{Available as}: command line option, command @node calc, mfilter, fractal, menus @appendixsec Calculation This menu contains functions that control calculation parameters such as the maximum iteration count and periodicity checking. @menu * range:: Solid guessing * dynamic:: Dynamic resolution * periodicity:: Periodicity checking * maxiter:: Iterations * bailout:: Bailout * fastjulia:: Fast Julia mode * dynamic:: Dynamic resolution * rotate:: Rotation @end menu @node range, periodicity, , calc @appendixsubsec Solid guessing range @defun range integer @end defun 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. @emph{Available as}: command line option, command @node periodicity, maxiter, range, calc @appendixsubsec Periodicity checking @defun periodicity bool @end defun Periodicity checking is one way to speed up the calculation. Areas inside the set always need @code{maxiter} 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). 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. 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 incoloring 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.) The tutorial chapter ``Escape time fractals'' has more information on fractal calculation in XaoS, and there is a lengthy section in the hacker's manual (@code{xaosdev.texinfo}) devoted to the subject. @emph{Available as}: menu item, command line option, command @node maxiter, bailout, periodicity, calc @appendixsubsec Iterations @defun maxiter integer @end defun 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. 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. The tutorial chapter ``Escape time fractals'' has more information on fractal calculation in XaoS, and there is a lengthy section in the hacker's manual (@code{xaosdev.texinfo}) devoted to the subject. @emph{Available as}: menu item, command line option, command @node fastjulia, dynamic, bailout, calc @appendixsubsec Fast Julia mode @defun fastjulia bool @end defun 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. 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 Julia mode to see the exact image. @emph{Available as}: menu item, command line option, command @node dynamic, rotate, fastjulia, calc @appendixsec Dynamic resolution @defun fastmode keyword @end defun 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. In the scripting languge, the keyword should be one of the following: @table @strong @item @code{'never} Disable dynamic resolution @item @code{'animate} Use only for animations (default) @item @code{'new} Use also for new images @end table @node rotate, , dynamic, calc @appendixsec Image rotation 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} 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. The user interface provides two rotation modes---@emph{rotate by mouse} which allows the angle to be changed by dragging with the first mouse button depressed, and @emph{continuous rotation mode}, where the image is rotated clockwise continuously, and the arrow keys can be used to change the rotiation speed. @defun fastrotate bool @end defun This function is used to enable and disable fast rotation mode. @emph{Available as}: command line option, command @appendixsubsec Automatic rotation @defun autorotate bool @end defun Use this function to enable continuous rotation. In the scripting language you can also use @code{morphangle} to get an outwardly similar but more controllable effect. @defun rotationspeed float @end defun Specify the speed of continuous rotation, in degrees per second. Negative values are allowed and rotate anticlockwise. @emph{Available as}: menu item, command line option, command @node mfilter, ui, calc, menus @appendixsec Filters 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 tutorial chapter about them. @menu * filter:: Filter command * edge:: Edge detection * edge2:: Edge detection2 * starfield:: Starfield * stereogram:: Random dot stereogram * interlace:: Interlace filter * blur:: Motion blur * emboss:: Emboss * palettef:: Palette emulator * anti:: Antialiasing * truecolor:: Truecolor emulator @end menu @node filter, edge, , mfilter @appendixsubsec Filter command @defun filter keyword bool @end defun This command is used to enable or disable filters. @xref{mfilter}. The @emph{keyword} specifies the filter to change, and should be one of the following: @table @strong @item @code{'edge} Edge detection @item @code{'edge2} Edge detection2 @item @code{'starfield} Starfield @item @code{'stereogram} Random dot stereogram @item @code{'interlace} Interlace filter @item @code{'blur} Motion blur @item @code{'emboss} Emboss @item @code{'palette} Palette emulator @item @code{'anti} Antialiasing @item @code{'truecolor} Truecolor @end table @emph{Available as}: command @node edge, edge2, filter, mfilter @appendixsubsec Edge detection 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 edge detection2 makes thinner lines, for the low resolution modes. @emph{Available as}: menu item, command line option @node edge2, starfield, edge, mfilter @appendixsubsec Edge detection2 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 edge detection makes thinner lines, for the high resolution modes. @emph{Available as}: menu item, command line option @node starfield, stereogram, edge2, mfilter @appendixsubsec Starfield 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 :) @emph{Available as}: menu item, command line option @node stereogram, interlace, starfield, mfilter @appendixsubsec Random dot stereogram 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). 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. To make this work right, XaoS needs to know the @emph{exact size of your monitor}. Because most platforms have no way to determine this, you need to use @emph{command line options} 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). 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. 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. The following command line options are provided to specify sizes: @table @strong @item @code{-screenwidth}, @code{-screenheight} 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. @item @code{-pixelwidth}, @code{-pixelheight} Lets you specify the exact size of a single pixel, if XaoS cannot determine this for itself from your screen size. @end table 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. If the window is @emph{smaller than 8cm in any direction}, you will probably be unable to see anything; make the window bigger. The correct way to see XaoS stereograms is: @table @strong @item 1 Start XaoS with options specifying the exact size of your screen or one pixel on it @item 2 Sit 60cm away from monitor @item 3 If you use a windowed environment, resize XaoS's window to make it wider than, say, 15 cm. @item 4 Enable the filter (by pressing @code{E}) @item 5 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. @item 6 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...) @item 7 Enjoy animation :) @end table 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. @emph{Available as}: menu item, command line option @node interlace, blur, stereogram, mfilter @appendixsubsec Interlace filter 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. @emph{Available as}: menu item, command line option @node blur, emboss, interlace, mfilter @appendixsubsec Motion blur 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 palette filter first. @emph{Available as}: menu item, command line option @node emboss, palettef, blur, mfilter @appendixsubsec Emboss This is a standard emboss filter, as seen in programs such as the GIMP or Photoshop. It produces especially nice results with the smooth outcoloring mode. @xref{outcoloring}. @emph{Available as}: menu item, command line option @node palettef, anti, emboss, mfilter @appendixsubsec Palette emulator XaoS can work in either palette or truecolor mode. Both modes have advantages and disadvantages. Palette mode allows effects such as palette rotation, while truecolor mode allows smoother incoloring and outcoloring modes and the truecolor coloring 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). @emph{Available as}: menu item, command line option @node anti, truecolor, palettef, mfilter @appendixsubsec Antialiasing 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. This filter slows XaoS down a @emph{lot} 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). @emph{Available as}: menu item, command line option @node truecolor, , anti, mfilter @appendixsubsec Truecolor emulator XaoS can work in either palette or truecolor mode. Both modes have advantages and disadvantages. Palette mode allows effects such as palette rotation, while truecolor mode allows smoother incoloring and outcoloring modes and the truecolor coloring 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). More information about filters @emph{Available as}: menu item, command line option @node ui, misc, mfilter, menus @appendixsec UI This menu contains functions to control the user interface layer of XaoS: zooming speed, the autopilot, realtime status information, and so on. @menu * speed:: Zooming speed * letterspersec:: Letters per second * autopilot:: Autopilot * recalculate:: Recalculate * interrupt:: Interrupt * nogui:: Disable XaoS's builtin GUI * status:: Status * ministatus:: Ministatus @end menu @node speed, letterspersec, , ui @appendixsubsec Zooming speed @defun speed float @end defun Change zooming speed, where 1 is the default, 2 means twice as fast, and so on. @emph{Available as}: menu item, command line option, command In the scripting language you can use the following functions for better control: @defun maxstep float @end defun 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. @emph{Available as}: command @defun speedup float @end defun When zooming/unzooming, every twentieth of a second the @code{speedup} value is added to the current step until @code{maxstep} 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. @emph{Available as}: command @node letterspersec, autopilot, speed, ui @appendixsubsec Letters per second @defun letterspersec integer @end defun Speed of subtitles for the @code{textsleep} function. The user can set this value to suit; it can also be changed with the left and right arrow keys during animation replay. @emph{Available as}: command line option, command @node autopilot, recalculate, letterspersec, ui @appendixsubsec Autopilot @defun autopilot bool @end defun To make XaoS yet more impressive, we made a special autopilot mode that automatically drives into interesting boundaries of the set; you should press @code{A}, 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. 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. @emph{Available as}: menu item, command line option, command @node recalculate, interrupt, autopilot, ui @appendixsubsec Recalculate @defun recalculate @end defun Recalculate current fractal. This should be used when the fractal on the screen is strange because of error propagation caused by solid guessing. @xref{range}. @emph{Available as}: menu item, command line option, command @node interrupt, nogui, recalculate, ui @appendixsubsec Interrupt @defun interrupt @end defun Interrupt current calculation. @emph{Available as}: menu item, command line option, command @node nogui, status, interrupt, ui @appendixsubsec Disable XaoS's builtin GUI @defun nogui bool @end defun 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 (@code{xaosdev.texinfo}) for more details. @emph{Available as}: menu item, command line option, command @node status, ministatus, nogui, ui @appendixsubsec Status @defun status bool @end defun 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...) @emph{Available as}: menu item, command line option, command @node ministatus, , status, ui @appendixsubsec Ministatus @defun ministatus bool @end defun Enable/disable status line. This contains basic information such as how much you are zoomed and the framerate. @emph{Available as}: menu item, command line option, command @node misc, helpmenu, ui, menus @appendixsec Misc Miscellaneous functions. @menu * command:: Command * renderanim:: Render animation * clearscreen:: Clear screen * display:: Display fractal * text:: Display text * color:: Color * xtextpos:: Horizontal text position * ytextpos:: Vertical text position * textposition:: Text position * message:: Message @end menu @node command, renderanim, , misc @appendixsubsec Command 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 XaoS animation file instead; they are written in the same language. @emph{Available as}: menu item @node renderanim, clearscreen, command, misc @appendixsubsec Render animation Render an animation to image files. See How to encode MPEG files for more information. @emph{Available as}: menu item, @node clearscreen, display, renderanim, misc @appendixsubsec Clear screen @defun clearscreen @end defun Clear the screen. To display the fractal again, use @code{display}. @xref{display}. This function is mainly useful in tutorials and similar animations. @emph{Available as}: menu item, command @node display, text, clearscreen, misc @appendixsubsec Display fractal @defun display @end defun Display fractal. This functions reverses the effect of the @code{clearscreen}, line drawing and text output functions. @emph{Available as}: menu item, command @node text, color, display, misc @appendixsubsec Display text @defun text string @end defun 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 @code{clearscreen} or @code{display} functions. You might also want to use the @code{textposition} function to select the part of the screen to display the text on. To wait for the user to read the text, you can use the @code{textsleep} function. Example: @example (clearscreen) (textposition 'center 'middle) (text "Welcome into my animation") (textsleep) (display) @end example @emph{Available as}: menu item, command line option, command @node color, textposition, text, misc @appendixsubsec Color @defun color keyword @end defun Change text and line color. @emph{keyword} should be one of @code{'white}, @code{'black} and @code{'red}. @emph{Available as}: menu item, command line option, command @node textposition, message, color, misc @appendixsubsec Text position @defun textposition keyword keyword @end defun Select text position. The first keyword specifies the horizontal position, the second the vertical position. The horizontal position should be one of @code{'left}, @code{'center}, and @code{'right}. The vertical should be one of @code{'top}, @code{'middle}, and @code{'bottom}. @emph{Available as}: command line option, command @node message, , textposition, misc @appendixsubsec Message @defun message string @end defun This function is almost identical to the @code{text} function, except that it uses message catalogs in the @code{catalog} directory to translate messages into other languages. It should be used only in the multi-lingual XaoS tutorials. @emph{Available as}: command line option, command @node helpmenu, xtextpos, misc, menus @appendixsec Help This menu contains help and tutorials. @node xtextpos, ytextpos, helpmenu, menus @appendixsec Horizontal text position Select the horizontal position used to display text. @xref{text}. It can be placed at the left, in the center or at the right. @node ytextpos, mformula, xtextpos, menus @appendixsec Vertical text position Select the vertical position used to display text. @xref{text}. It can be placed at the top, in the middle or at the bottom of the screen. @node mformula, palettemenu, ytextpos, menus @appendixsec formulae Each escape time fractal has its own formula. XaoS supports the following formulae: @menu * mandel:: Mandelbrot * mandel3:: Mandelbrot^3 * octal:: Octal * newton:: Newton * barnsley:: Barnsley1 * phoenix:: Phoenix * magnet:: Magnet @end menu @node mandel, mandel3, , mformula @appendixsubsec Mandelbrot The Mandelbrot set is the most famous escape time fractal ever. It has the simple formula @math{z=z^2+c}. See the tutorial chapter. @emph{Available as}: menu item, command line option @node mandel3, octal, mandel, mformula @appendixsubsec Mandelbrot^3---Mandelbrot^6 and Mandelbrot^9 The Mandelbrot^3 fractal is a simple modification of the standard Mandelbrot set formula, using @math{z=z^3+c} instead of @math{z=z^2+c}. Other derivations of the Mandelbrot set (Mandelbrot^4 and so on) use even higher powers. See the tutorial chapter. @emph{Available as}: menu item, command line option @node octal, newton, mandel3, mformula @appendixsubsec Octal This is a less well-known fractal that Thomas discovered in Fractint. It has an interesting shape when displayed in the alternative planes. @xref{plane}. See the tutorial chapter. @emph{Available as}: menu item, command line option @node newton, barnsley, octal, mformula @appendixsubsec Newton This is Newton's approximation method for finding the roots of a polynomial. It uses the polynomial @math{x^3=1} and counts the number of iterations needed to reach the approximate value of the root. See the tutorial chapter. 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''). @emph{Available as}: menu item, command line option @node barnsley, phoenix, newton, mformula @appendixsubsec Barnsley1 This is a formula by Michael Barnsley. It produces very nice crystalline Julia sets. See the tutorial chapter. @emph{Available as}: menu item, command line option @node phoenix, magnet, barnsley, mformula @appendixsubsec Phoenix This formula produces very nice Julia sets. See the tutorial chapter. @emph{Available as}: menu item, command line option @node magnet, , phoenix, mformula @appendixsubsec Magnet 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 tutorial chapter. @emph{Available as}: menu item, command line option @node palettemenu, , mformula, menus @appendixsec Palette This menu contains functions to change the palette the fractal is displayed with. @menu * defpalette:: Default palette * randompalette:: Random palette * palette:: Custom palette * cycling:: Color cycling * shiftpalette:: Shift palette @end menu @node defpalette, randompalette, , palettemenu @appendixsubsec Default palette @defun defaultpalette number @end defun Create a default palette. In the scripting language, @code{number} specifies how much the palette is shifted by. Note that changing the palette in truecolor modes forces recalculation of the whole screen. To avoid this, you can enable the palette emulation filter first. @emph{Available as}: menu item, command line option, command @node randompalette, palette, defpalette, palettemenu @appendixsubsec Random palette @defun randompalette @end defun Create a random palette. XaoS will automatically pick one of its palette-generation algorithms and create one. Note that changing the palette in truecolor modes forces recalculation of the whole screen. To avoid this, you can enable the palette emulation filter first. @emph{Available as}: menu item, command line option, command @node palette, cycling, randompalette, palettemenu @appendixsubsec Custom palette @defun palette integer integer integer @end defun 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: @table @strong @item 0 Default palette @item 1 Black to color gradient @item 2 Black to color to white gradient @item 3 Cubistic-like algorithm. @end table 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. Note that changing the palette in the truecolor modes forces recalculation of the whole screen. To avoid this, you can enable the palette emulation filter first. @emph{Available as}: menu item, command line option, command @node cycling, shiftpalette, palette, palettemenu @appendixsubsec Color cycling @defun cycling bool @end defun 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 palette emulation filter to make it possible. @emph{Available as}: menu item, command line option, command In the user interface, colors can also be cycled in the opposite direction with the ``@emph{Reversed color cycling}'' function. To control the cycling speed, you coan use arrow keys or the ``@emph{Color cycling speed}'' function. @emph{Available as}: menu item @defun cyclingspeed integer @end defun The parameter specifies the number of skips per second. It can be negative to cycle in the opposite direction. @emph{Available as}: menu item, command line option, command @node shiftpalette, , cycling, palettemenu @appendixsubsec Shift palette @defun shiftpalette integer @end defun 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} and @emph{Shift one backward} functions for fine-tuning. Note that shifted and rotated palettes could look different on different displays (because they may have different palette sizes). Shifting the palette on truecolor displays causes a recalculation of the screen. To avoid this, you could use palette emulation filter. @xref{palettef}. @emph{Available as}: menu item, command line option, command @c ## menus controls ## @c %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% @comment node-name, next, previous, up @node about, support,menus ,Top @appendix About XaoS @appendix Credits (alphabetically) @table @strong @item Lucio Henrique de Araujo (lucio.matema@@gmail.com) Brazilian/Portuguese translation @item Samuel Bizien (samuel@@bizien.info) Beryl fractal @item Eric Courteau (ecourteau@@cplus.fr) francais.cat (translation of tutorials) @item Jean-Pierre Demailly (Jean-Pierre.Demailly@@ujf-grenoble.fr) Updates for French translation @item Radek Doulik (rodo@@atrey.karlin.mff.cuni.cz) TK interface, windowid patches @item Martin Dozsa (madsoft@@centrum.cz) cs.po (Czech translation of menus) @item Arpad Fekete (Fekete.Arpad.2@@stud.u-szeged.hu) Some new fractals, and the 'More formulae' menu @item Zelia Maria Horta Garcia (zeliagarcia@@seed.pr.gov.br) Brazilian/Portuguese translation @item Tim Goodwin (tgoodwin@@cygnus.co.uk) english.cat corrections @item Ben Hines autoconf suggestions, Mac OS X port @item Jan Hubicka (jh@@ucw.cz) Zooming routines, ugly interface, palettes, drivers, autopilot, filters, documentation, tutorials etc. @item Jens Kilian (jjk@@acm.org) BeOS driver, deutsch.cat @item Thomas A. K. Kjaer (takjaer@@imv.aau.dk) OS/2 ports (320x200 graphics and AA-lib) @item Zoltan Kovacs (kovzol@@math.u-szeged.hu) Internationalization, Hungarian translations, finalizing version 3.1, bug fixes, web design, current maintainer @item Zsigmond Kovacs (kovzsi@@gmail.com) Fractal examples @item J.B. Langston III (jb-langston@@austin.rr.com) Native Mac OS X port (from version 3.2.2); web redesign; co-maintainer @item Andreas Madritsch (amadritsch@@datacomm.ch) New fractal types, bailout, many fixes @item Mateusz Malczak (xaos@@malczak.info) User formula evaluation library @item Giorgio Marazzi (gmarazzi@@vtr.net) Improvements and fixes for espanhol.cat @item Thomas Marsh (thomas.marsh2@@gmail.com) First zoomer, formulae, planes, X11 driver, inversions, many ideas @item Dominic Mazzoni (dmazzoni@@cs.cmu.edu) Macintosh port (version 2.0) @item David Meleedy Grammatical and spelling fixed version of @code{xaos.6} @item Paul Nasca (zynaddsubfx@@yahoo.com) Ministatus improvement @item Nix (nix@@esperi.demon.co.uk) Grammatical and spelling fixed version of @code{xaos.hlp} and other files @item Terje Pedersen (terjepe@@login.eunet.no) Amiga port @item Cesar Perez (oroz@@users.sourceforge.net) Spanish translations @item Fabrice Premel (premelfa@@etu.utc.fr) Periodicity checking @item Jan Olderdissen (jan@@olderdissen.com) Win32 port @item Ilinca Sitaru (ilinca.sitaru@@gmail.com) Romanian translation @item Daniel Skarda Fractal examples @item Andrew Stone (Stone Design - www.stone.com) Videator Support, Cocoa improvements, performance mode, bug fixes @item Marton Torok (marton.torok@@gmail.com) Small fixes for pipes @item Pavel Tzekov (paveltz@@csoft.bg) Win32 support @item Charles Vidal Tcl/Tk interface @item Tapio K. Vocaldo (taps@@rmx.com) Macintosh port @item Tormod Volden Fixes for X11 driver to improve compatability with Xorg, XScreenSaver, Beryl and Compiz @item Philippe Wautelet (p.wautelet@@fractalzone.be) Bug fixes for version 3.1.1, French translation, gcc 4.0 fixes @item Sergio Zanchetta Italian translation @end table @subsection Included Software XaoS uses the following libraries. These libraries may be included with some binary distributions of XaoS. @emph{gettext 0.17} Website: @code{http://www.gnu.org/software/gettext/} Copyright (C) 1995-1997, 2000-2007 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later (http://gnu.org/licenses/gpl.html) This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law. @emph{GNU Scientific Library 1.11} Website: @code{http://www.gnu.org/software/gsl/} Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007 The GSL Team. License GPLv3+: GNU GPL version 3 or later (http://gnu.org/licenses/gpl.html) This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law. @emph{libpng 1.2.25} Website: @code{http://www.libpng.org/pub/png/libpng.html} Copyright (c) 1998-2008 Glenn Randers-Pehrson Copyright (c) 1996-1997 Andreas Dilger Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc. @c ## appendix about ## @c %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% @comment node-name, next, previous, up @node support, index ,about ,Top @appendix Getting Support XaoS is a community-supported free software project. There are many ways to get help, all of which are explained below. @appendix Home Page The XaoS homepage is @code{http://xaos.sf.net}. Check here for the latest news and information about XaoS and to download the latest versions. @subsection Discussion Forums XaoS has two discussion forums hosted on SourceForge. You can read them freely, but in order to post, you must to register for a free SourceForge account. @table @strong @item Help Provides a place for you to ask for help using XaoS. Other XaoS users and/or the XaoS developers will answer your questions. @code{http://sourceforge.net/forum/forum.php?forum_id=17768} @item Open Discussion Provides a place to discuss anything related to XaoS or fractals. You can share tips, your own fractal creations, or any other fractal-related ideas with other XaoS users. @code{http://sourceforge.net/forum/forum.php?forum_id=17767} @end table We welcome you to join these forums and become involved in the XaoS community. @subsection Mailing Lists XaoS currently has three mailing lists hosted on SourceForge. Unfortunately, there is currently very little traffic on any of them. Hopefully in the future, we can get more XaoS users and developers involved in the mailing lists. The lists are as follows: @table @strong @item xaos-announce@@lists.sourceforge.net Low volume list that is used only to announce new releases. Subscribe: @code{http://lists.sourceforge.net/mailman/listinfo/xaos-announce} Archive: @code{http://sourceforge.net/mailarchive/forum.php?forum_name=xaos-announce} @item xaos-devel@@lists.sourceforge.net Developer mailing list, where the developers coordinate and discuss XaoS development. Subscribe: @code{http://lists.sourceforge.net/mailman/listinfo/xaos-devel} Archive: @code{http://sourceforge.net/mailarchive/forum.php?forum_name=xaos-devel} @item xaos-discuss@@lists.sourceforge.net General discussion list is for XaoS users to share tips and ideas about XaoS. Subscribe: @code{http://lists.sourceforge.net/mailman/listinfo/xaos-discuss} Archive: @code{http://sourceforge.net/mailarchive/forum.php?forum_name=xaos-discuss} @end table Please feel free to join any or all of these mailing lists and share your ideas with the developers and other XaoS users. @subsection Bug Reports If you think you have found a bug in XaoS, please report it. The developers will do their best to resolve the bug in a timely manner. Bug Tracker: @code{http://sourceforge.net/tracker/?atid=105771&group_id=5771} Please don't submit duplicate bugs. Browse the existing ones first to make sure nobody has already reported it. You may add additional information about a bug by entering a comment on an existing bug. If you are not sure if something is a bug, please open a support request. The developers will try to answer your question and can convert your support request to a bug if necessary. Support Requests: @code{http://sourceforge.net/tracker/?atid=205771&group_id=5771} @subsection Feature Requests If you have an idea for a great new feature you'd like to see added to XaoS, please let us know about it. You can submit a feature request via SourceForge, and the XaoS developers will do their best to implement your request in a future version. Feature Requests: @code{http://sourceforge.net/tracker/?atid=355771&group_id=5771} Please don't submit duplicate feature requests. Browse the existing ones first to make sure nobody has already requested the feature your want. You may add your vote for a feature by adding a comment to the existing request. @c ## appendix support ## @c %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% @comment node-name, next, previous, up @node index, ,support ,Top @unnumbered Index of functions @printindex fn @contents @bye