- Getting Started
To start the program, enter FRACTINT at the DOS prompt. The program displays an initial 'credits' screen. If FractInt does not start properly, please see Common Problems
Hitting [Enter] gets you from the initial screen to the main menu. You can select options from the menu by moving the highlight with the cursor arrow keys and pressing [Enter], or you can enter commands directly.
As soon as you select a video mode, FractInt begins drawing an image - the 'full' Mandelbrot set if you have not selected another fractal type. For a quick start, after starting FractInt try one of the following:
If you have MCGA, VGA, or better: [F3] If you have EGA: [F9] If you have CGA: [F5] Otherwise, monochrome: [F6]
After the initial Mandelbrot image has been displayed, try zooming into it (see Zoom Box Commands) and color cycling (see Color Cycling Commands). Once you are comfortable with these basics, start exploring other functions from the main menu.
Help is available from the menu and at most other points in FractInt by pressing the [F1] key.
AT ANY TIME, you can hit a command key to select a function. You do not need to wait for a calculation to finish, nor do you have to return to the main menu.
When entering commands, note that for the 'typewriter' keys, upper and lower case are equivalent, e.g. [B] and [b] have the same result.
Many commands and parameters can be passed to FRACTINT as command-line arguments or read from a configuration file; see 'Command Line Parameters, Parameter Files, Batch Mode' for details.
- Plotting Commands
Function keys & various combinations are used to select a video mode and redraw the screen. For a quick start try one of the following:
If you have MCGA, VGA, or better: [F3] If you have EGA: [F9] If you have CGA: [F5] Otherwise, monochrome: [F6]
Display a help screen. The function keys available in help mode are displayed at the bottom of the help screen.
- [M] or [Esc]
Return from a displayed image to the main menu.
- [Esc] From the main menu, [Esc] is used to exit from FractInt.
Same as choosing 'select video mode' from the main menu. Goes to the 'select video mode' screen. See Video Mode Function Keys.
Redraw the previous image in the circular history buffer, revisiting
fractals you previously generated this session in reverse order.
FractInt saves the last ten images worth of information including
fractal type, coordinates, colors, and all options. Image information is
saved only when some item changes. After ten images the circular buffer
wraps around and earlier information is overwritten. You can set image
capacity of the history feature using the maxhistory=[nnn] command.
About 1200 bytes of memory is required for each image slot.
Redraw the next image in the circular history buffer. Use this to return
to images you passed by when using [h].
Display the current fractal type, parameters, video mode, screen or (if
displayed) zoom-box coordinates, maximum iteration count, and other
information useful in keeping track of where you are. The Tab function
is non-destructive - if you press it while in the midst of generating an
image, you will continue generating it when you return. The Tab
function tells you if your image is still being generated or has
finished - a handy feature for those overnight, 1024x768 resolution
fractal images. If the image is incomplete, it also tells you whether
it can be interrupted and resumed. (Any function other than [Tab]
and [F1] counts as an 'interrupt'.)
The Tab screen also includes a pixel-counting function, which will count the number of pixels colored in the inside color. This gives an estimate of the area of the fractal. Note that the inside color must be different from the outside color(s) for this to work; inside=0 is a good choice.
- [T] Select a fractal type. Move the cursor to your choice (or type the first few letters of its name) and hit [Enter]. Next you will be prompted for any parameters used by the selected type - hit [Enter] for the defaults. See Fractal Types for a list of supported types.
- [F] Toggles the use of floating-point algorithms (see 'Limitations of Integer Math (And How We Cope)' ). Whether floating point is in use is shown on the [Tab] status screen. The floating point option can also be turned on and off using the 'X' options screen. If you have a non-Intel floating point chip which supports the full 387 instruction set, see the 'FPU=' command in Startup Parameters to get the most out of your chip.
- [X] Select a number of eXtended options. Brings up a full-screen menu of options, any of which you can change at will. These options are:
- 'passes=' - see Drawing Method
- Floating point toggle - see [F] key description above
- 'maxiter=' - see Image Calculation Parameters
- 'inside=' and 'outside=' - see Color Parameters
- 'savename=' filename - see File Parameters
- 'overwrite=' option - see File Parameters
- 'sound=' option - see Sound Parameters
- 'logmap=' - see Logarithmic Palettes and Color Ranges
- 'biomorph=' - see Biomorphs
- 'decomp=' - see Decomposition
- 'fillcolor=' - see Drawing Method
- [Y] More options which we couldn't fit under the [X] command:
- [Z] Modify the parameters specific to the currently selected fractal type. This command lets you modify the parameters which are requested when you select a new fractal type with the [T] command, without having to repeat that selection. You can enter 'e' or 'p' in column one of the input fields to get the numbers e and pi (2.71828... and 3.14159...). From the fractal parameters screen, you can press [F6] to bring up a sub parameter screen for the coordinates of the image's corners. With selected fractal types, [Z] allows you to change the Bailout Test
- [+] or [-] Switch to color-cycling mode and begin cycling the palette by shifting each color to the next 'contour'. See Color Cycling Commands
- [C] Switch to color-cycling mode but do not start cycling. The normally black 'overscan' border of the screen changes to white. See Color Cycling Commands
- [E] Enter Palette-Editing Mode. See Palette Editing Commands.
- [Spacebar] Toggle between Mandelbrot set images and their corresponding Julia-set images. Read the notes in Fractal Types, Julia Sets before trying this option if you want to see anything interesting.
- [J] Toggle between Julia escape time fractal and the Inverse Julia orbit fractal. See Inverse Julias
- [Enter] Enter is used to resume calculation after a pause. It is only necessary to do this when there is a message on the screen waiting to be acknowledged, such as the message shown after you save an image to disk.
- [I] Modify 3D transformation parameters used with 3D fractal types such as 'Lorenz3D' and 3D 'IFS' definitions, including the selection of 'funny glasses' red/blue 3D.
- [A] Convert the current image into a fractal 'starfield'. See Starfields
- [Ctrl-A] Unleash an image-eating ant automaton on current image. See Ant Automaton.
- [Ctrl-S] (or [k]) Convert the current image into a Random Dot Stereogram (RDS). See Random Dot Stereograms (RDS)
- [O] (the letter, not the number) If pressed while an image is being generated, toggles the display of intermediate results -- the 'orbits' FractInt uses as it calculates values for each point. Slows the display a bit, but shows you how clever the program is behind the scenes. (See 'A Little Code' in 'Fractals and the PC'
- [D] Shell to DOS. Return to FractInt by entering 'exit' at a DOS prompt.
- [Insert] Restart at the 'credits' screen and reset most variables to their initial state. Variables which are not reset are: savename, lightname, video, startup filename.
- [L] Enter Browsing Mode. See Browse Commands.
- [Ctrl-E] Enter Explorer/Evolver Mode. See Evolver Commands
- Zoom box Commands
Zoom Box functions can be invoked while an image is being generated or when it has been completely drawn. Zooming is supported for most fractal types, but not all.
The general approach to using the zoom box is: Frame an area using the keys described below, then [Enter] to expand what is in the frame to fill the whole screen (zoom in); or [Ctrl] [Enter] to shrink the current image into the framed area (zoom out). With a mouse, double-click the left button to zoom in, double click the right button to zoom out.
- [Page Up], [Page Down]
Use [Page Up] to initially bring up the zoom box. It starts at full screen size. Subsequent use of these keys makes the zoom box smaller or larger. Using [Page Down] to enlarge the zoom box when it is already at maximum size removes the zoom box from the display. Moving the mouse away from you or toward you while holding the left button down performs the same functions as these keys.
Using the cursor 'arrow' keys or moving the mouse without holding any buttons down, moves the zoom box.
Holding [Ctrl] while pressing cursor 'arrow' keys moves the box 5 times faster. (This only works with enhanced keyboards.)
Panning: If you move a fullsize zoombox and do not change anything else before performing the zoom, FractInt just moves what is already on the screen and then fills in the new edges, to reduce drawing time. This feature applies to most fractal types but not all. A side effect is that while an image is incomplete, a full size zoom box moves in steps larger than one pixel. FractInt keeps the box on multiple pixel boundaries, to make panning possible. As a multi-pass (e.g. solid guessing) image approaches completion, the zoom box can move in smaller increments.
In addition to resizing the zoom box and moving it around, you can do some rather warped things with it. If you are a new FractInt user, we recommend skipping the rest of the zoom box functions for now and coming back to them when you are comfortable with the basic zoom box functions.
- [Ctrl] [Keypad-], [Ctrl] [Keypad+] Holding [Ctrl] and pressing the numeric keypad's + or - keys rotates the zoom box. Moving the mouse left or right while holding the right button down performs the same function.
- [Ctrl] [Page Up], [Ctrl] [Page Down] These commands change the zoom box's 'aspect ratio', stretching or shrinking it vertically. Moving the mouse away from you or toward you while holding both buttons (or the middle button on a 3-button mouse) down performs the same function. There are no commands to directly stretch or shrink the zoom box horizontally - the same effect can be achieved by combining vertical stretching and resizing.
- [Ctrl] [Home], [Ctrl] [End] These commands 'skew' the zoom box, moving the top and bottom edges in opposite directions. Moving the mouse left or right while holding both buttons (or the middle button on a 3-button mouse) down performs the same function. There are no commands to directly skew the left and right edges - the same effect can be achieved by using these functions combined with rotation.
- [Ctrl] [Insert], [Ctrl] [Delete] These commands change the zoom box color. This is useful when you are
having trouble seeing the zoom box against the colors around it. Moving
the mouse away from you or toward you while holding the right button
down performs the same function.
You may find it difficult to figure out what combination of size, position rotation, stretch, and skew to use to get a particular result. (We do.)
A good way to get a feel for all these functions is to play with the Gingerbreadman fractal type. Gingerbreadman's shape makes it easy to see what you are doing to him. A warning though: Gingerbreadman will run forever, he is never quite done! So, pre-empt with your next zoom when he is baked enough.
If you accidentally change your zoom box shape or rotate and forget which way is up, just use [PageDown] to make it bigger until it disappears, then [PageUp] to get a fresh one. With a mouse, after removing the old zoom box from the display release and re-press the left button for a fresh one.
If your screen does not have a 4:3 'aspect ratio' (i.e. if the visible display area on it is not 1.333 times as wide as it is high), rotating and zooming will have some odd effects - angles will change, including the zoom box's shape itself, circles (if you are so lucky as to see any with a non-standard aspect ratio) become non-circular, and so on. The vast majority of PC screens *do* have a 4:3 aspect ratio.
Zooming is not implemented for the plasma and diffusion fractal types, nor for overlayed and 3D images. A few fractal types support zooming but do not support rotation and skewing - nothing happens when you try it.
- [Page Up], [Page Down]
- Color Cycling Commands
Color-cycling mode is entered with the [c], [+], or [-] keys from an image, or with the [c] key from Palette-Editing mode.
The color-cycling commands are available ONLY for VGA adapters and EGA adapters in 640x350x16 mode. You can also enter color-cycling while using a disk-video mode, to load or save a palette - other functions are not supported in disk-video.
Note that the colors available on an EGA adapter (16 colors at a time out of a palette of 64) are limited compared to those of VGA, super-VGA, and MCGA (16 or 256 colors at a time out of a palette of 262,144). So color-cycling in general looks a LOT better in the latter modes. Also, because of the EGA palette restrictions, some commands are not available with EGA adapters.
Color cycling applies to the color numbers selected by the 'cyclerange=' command line parameter (also changeable via the [Y] options screen and via the palette editor). By default, color numbers 1 to 255 inclusive are cycled. On some images you might want to set 'inside=0' ([X] options or command line parameter) to exclude the 'lake' from color cycling.
When you are in color-cycling mode, you will either see the screen colors cycling, or will see a white 'overscan' border when paused, as a reminder that you are still in this mode. The keyboard commands available once you have entered color-cycling are described below.
Bring up a HELP screen with commands specific to color cycling mode.
- [Esc] Leave color-cycling mode.
- [Home] Restore original palette.
- [+] or [-] Begin cycling the palette by shifting each color to the next 'contour'. [+] cycles the colors in one direction, [-] in the other.
- < or > Force a color-cycling pause, disable random colorizing, and single-step through a one color-cycle. For 'fine-tuning' your image colors.
- Cursor up/down Increase/decrease the cycling speed. High speeds may cause a harmless flicker at the top of the screen.
- [F2] through [F10] Switches from simple rotation to color selection using randomly generated color bands of short (F2) to long (F10) duration.
-  through  Causes the screen to be updated every [n] color cycles (the default is 1). Handy for slower computers.
- [Enter] Randomly selects a function key (F2 through F10) and then updates ALL the screen colors prior to displaying them for instant, random colors. Hit this over and over again (we do).
- [Spacebar] Pause cycling with white overscan area. Cycling restarts with any command key (including another spacebar).
- [Shift] [F1] - [F10] Pause cycling and reset the palette to a preset two color 'straight' assignment, such as a spread from black to white. (Not for EGA)
- [Ctrl] [F1]-[F10] Pause & set a 2-color cyclical assignment, e.g. red-> yellow-> red (not EGA).
- [Alt] [F1]-[F10] Pause & set a 3-color cyclical assignment, e.g. green-> white-> blue (not EGA).
- [R], [G], [B] Pause and increase the red, green, or blue component of all colors by a small amount (not for EGA). Note the case distinction of this vs:
- [r], [g], [b] Pause and decrease the red, green, or blue component of all colors by a small amount (not for EGA).
- [D] or [A] Pause and load an external color map from the files DEFAULT.MAP or ALTERN.MAP, supplied with the program.
- [L] Pause and load an external color map (.MAP file). Several .MAP files are supplied with FractInt. See Palette Maps.
- [S] Pause, prompt for a filename, and save the current palette to the named file (.MAP assumed). See Palette Maps.
- Palette Editing Commands
Palette-editing mode provides a number of tools for modifying the colors in an image. It can be used only with MCGA or higher adapters, and only with 16 or 256 color video modes. Many thanks to Ethan Nagel for creating the palette editor.
Use the [E] key to enter palette-editing mode from a displayed image or from the main menu.
When this mode is entered, an empty palette frame is displayed. You can use the cursor keys to position the frame outline, and [Pageup] and [Pagedn] to change its size. (The upper and lower limits on the size depend on the current video mode.) When the frame is positioned where you want it, hit Enter to display the current palette in the frame.
Note that the palette frame shows R(ed) G(reen) and B(lue) values for two color registers at the top. The active color register has a solid frame, the inactive register's frame is dotted. Within the active register, the active color component is framed.
With a video mode of 640x400 or higher, a status area appears between the two color registers. This status area shows:
nnn = color number at the cursor location A = Auto mode X, Y = exclusion modes F = freesyle mode T = stripe mode is waiting for #
Using the commands described below, you can assign particular colors to the registers and manipulate them. Note that at any given time there are two colors 'X'd - these are pre-empted by the editor to display the palette frame. They can be edited but the results will not be visible. You can change which two colors are borrowed ('X'd out) by using the [v] command.
Once the palette frame is displayed and filled in, the following commands are available:
Bring up a HELP screen with commands specific to palette-editing mode.
- [Esc] Leave palette-editing mode
- [H] Hide the palette frame to see full image; the cross-hair remains visible and all functions remain enabled; hit [H] again to restore the palette display.
- Cursor keys Move the cross-hair cursor around. In 'auto' mode (the default) the color under the center of the cross-hair is automatically assigned to the active color register. Control-Cursor keys move the cross-hair faster. A mouse can also be used to move around.
- [R] [G] [B] Select the Red, Green, or Blue component of the active color register for subsequent commands
- [Insert] [Delete] Select previous or next color component in active register
Increase or decrease the active color component value by 1 Numeric
keypad (gray) + and - keys do the same.
Increase or decrease the active color component value by 5; Moving the
mouse up/down with left button held is the same
     
Set the active color component's value to 0 10 20 ... 60
Select the other color register as the active one. In the default
'auto' mode this results in the now-inactive register being set to
remember the color under the cursor, and the now-active register
changing from whatever it had previously remembered to now follow the
Rotate the palette one step. By default colors 1 through 255 inclusive
are rotated. This range can be over-ridden with the 'cyclerange'
parameter, the [Y] options screen, or the [O]
command described below.
'<' or '>'
Rotate the palette continuously (until next keystroke)
Set the color cycling range to the range of colors currently defined by
the color registers.
Enter Color-Cycling Mode. When you invoke color-cycling from here, it
will subsequently return to palette-editing when you [Esc] from
Color Cycling Commands
Create a smoothly shaded range of colors between the colors selected by
the two color registers.
Specify a gamma value for the shading created by [=].
Duplicate the inactive color register's values to the active color
Stripe-shade - create a smoothly shaded range of colors between the two
color registers, setting only every Nth register. After hitting
[T], hit a numeric key from 2 to 9 to specify N. For example,
if you press [T] , smooth shading is done between the
two color registers, affecting only every 3rd color between them. The other
colors between them remain unchanged.
Convert current palette to gray-scale. (If the [X] or
ranges described later are in force, only the active range of colors is
converted to gray-scale.)
[Shift-F2] ... [Shift-F9]
Store the current palette in a temporary save area associated with the
function key. The temporary save palettes are useful for quickly
comparing different palettes or the effect of some changes - see next
command. The temporary palettes are only remembered until you exit from
Starting with version 19.6, when palette editing mode is entered, the original palette is stored in the area associated with F2.
[F2] ... [F9]
Restore the palette from a temporary save area. If you have not
previously saved a palette for the function key, you will get a simple
Pause and load an external color map (.MAP file). See
Palette Maps .
Pause, prompt for a filename, and save the current palette to the named
file (.MAP assumed). See
Palette Maps .
Invert frame colors. With some colors the palette is easier to see when
the frame colors are interchanged.
Move or resize the palette frame. The frame outline is drawn - it can
then be repositioned and sized with the cursor keys, [Pageup] and
[Pagedn], just as was done when first entering palette-editing
mode. Hit Enter when done moving/sizing.
- [V] Use the colors currently selected by the two color registers for the palette editor's frame. When palette editing mode is entered, the last two colors are 'X'd out for use by the palette editor; this command can be used to replace the default with two other color numbers.
- [A] Toggle 'auto' mode on or off. When on (the default), the active color register follows the cursor; when off, [Enter] must be pressed to set the active register to the color under the cursor.
- [Enter] Only useful when 'auto' is off, as described above; double clicking the left mouse button is the same as Enter.
- [X] Toggle 'exclude' mode on or off - when toggled on, only those image pixels which match the active color are displayed.
- [Y] Toggle 'exclude' range on or off - similar to [X], but all pixels matching colors in the range of the two color registers are displayed.
- [N] Make a negative color palette - will convert only current color if in [x] mode or range between editors in [y] mode or entire palette if in 'normal' mode.
<!> <@> <"> (English keyboard) <u-grave> (French keyboard) <#> <pound sign> (English keyboard) <$> (French keyboard) Swap R<->G, G<->B, and R<->B columns. <!>, <@>, and <#> are shifted 1, 2, and 3, which you may find easier to remember.
- [U] Undoes the last palette editor command. Will undo all the way to the beginning of the current session. [E] Redoes the undone palette editor commands.
- [F] Toggles 'Freestyle mode' on and off (Freestyle mode changes a range of
palette values smoothly from a center value outward). With your cursor
inside the palette box, press the [F] key to enter Freestyle
mode. A default range of colors will be selected for you centered at the cursor
(the ends of the color range are noted by putting dashed lines around
the corresponding palette values). While in Freestyle mode:
Moving the mouse changes the location of the range of colors that are affected.
- Control-Insert/Delete or the shifted-right-mouse-button changes the size of the affected palette range.
The normal color editing keys (R,G,B,1-6, etc) set the central color of the affected palette range. Pressing ENTER or double-clicking the left mouse button makes the palette changes permanent (if you do not perform this step, any palette changes disappear when you press the [F] key again to exit freestyle mode).
For more details see Freestyle mode tutorial.
- Image Save/Restore Commands
saves the current image to disk. All parameters required to recreate the image are saved with it. Progress is marked by colored lines moving down the screen's edges.
The default filename for the first image saved after starting FractInt is FRACT001.GIF; subsequent saves in the same session are automatically incremented 002, 003... Use the 'savename=' parameter or [X] options screen to change the name. By default, files left over from previous sessions are not overwritten - the first unused FRACTnnn name is used. Use the 'overwrite=yes' parameter or [X] options screen) to overwrite existing files.
A save operation can be interrupted by pressing any key. If you interrupt, you will be asked whether to keep or discard the partial file.
restores an image previously saved with [S], or an ordinary GIF
file. After pressing [R] you are shown the file names in the
current directory which match the current file mask. To select a file to
restore, move the cursor to it (or type the first few letters of its
name) and press [Enter].
Directories are shown in the file list with a '\' at the end of the name. When you select a directory, the contents of that directory are shown. Or, you can type the name of a different directory (and optionally a different drive) and press [Enter] for a new display. You can also type a mask such as '*.XYZ' and press [Enter] to display files whose name ends with the matching suffix (XYZ).
You can use [F6] to switch directories to the default FractInt directory or to your own directory which is specified through the DOS environment variable 'FRACTDIR'.
Once you have selected a file to restore, a summary description of the file is shown, with a video mode selection list. Usually you can just press [Enter]to go past this screen and load the image. Other choices available at this point are:
- Cursor keys:
- select a different video mode
- [Tab] :
- display more information about the fractal
- [F1] :
- for help about the 'err' column in displayed video modes If you restore a file into a video mode which does not have the same pixel dimensions as the file, FractInt will make some adjustments: The view window parameters (see [V]command) will automatically be set to an appropriate size, and if the image is larger than the screen dimensions, it will be reduced by using only every Nth pixel during the restore.
- Print Command
Print the current fractal image on your (Laserjet, Paintjet, Epson-compatible, PostScript, or HP-GL) printer.
'Disk-Video' Modes can be used to generate images for printing at higher resolutions than your screen supports.
- Parameter Save/Restore Commands
Parameter files can be used to save/restore all options and settings required to recreate particular images. The parameters required to describe an image require very little disk space, especially compared with saving the image itself.
- [@] or 
The [@] or  command loads a set of parameters describing an image. (Actually, it can also be used to set non-image parameters such as SOUND, but at this point we are interested in images. Other uses of parameter files are discussed in 'Parameter Files and the [@] Command'
When you hit [@] or , FractInt displays the names of the entries in the currently selected parameter file. The default parameter file, FRACTINT.PAR, is included with the FractInt release and contains parameters for some sample images.
After pressing [@] or , highlight an entry and press [Enter] to load it, or press [F6] to change to another parameter file.
Note that parameter file entries specify all calculation related parameters, but do not specify things like the video mode - the image will be plotted in your currently selected mode.
The [B]command saves the parameters required to describe the currently displayed image, which can subsequently be used with the [@] or  command to recreate it.
After you press [B], FractInt prompts for:
Parameter file: The name of the file to store the parameters in. You should use some name like 'myimages' instead of FRACTINT.PAR, so that your images are kept separate from the ones released with new versions of FractInt. You can use the PARMFILE= command in SSTOOLS.INI to set the default parameter file name to 'myimages' or whatever. (See 'Setting Defaults (SSTOOLS.INI File)' and 'parmfile=' in 'File Parameters'.)
Name: The name you want to assign to the entry, to be displayed when the [@] or  command is used.
Main comment: A comment to be shown beside the entry in the [@] command display.
Second, Third, and Fourth comment: Additional comments to store in the file with the entry. These comments go in the file only, and are not displayed by the [@] command. You can set these comments from the command line - see Comment= Command.
Record colors?: Whether color information should be included in the entry. Usually the default value displayed by FractInt is what you want. Allowed values are:
"no" - Do not record colors. "@mapfilename" - When these parameters are used, load colors from the named color map file. This is the default if you are currently using colors from a color map file. "yes" - Record the colors in detail. This is the default when you have changed the display colors by using the palette editor or by color cycling. The only reason that this is not what FractInt always does for the [B] command is that color infor- mation can be bulky - up to nearly 3K of disk space per map - which adds up to a lot for manyimages. Smooth-shaded ranges of colors are compressed, so if that is used a lot in an image the color information will not be as bulky. "only" - Record only the colors in the PAR file, without any other parameters. This is useful for converting color maps to PAR entries.
# of colors: This only matters if 'Record colors?' is set to 'yes'. It specifies the number of colors to record. Recording less colors will take less space. Usually the default value displayed by FractInt is what you want. You might want to increase it in some cases, e.g. if you are using a 256 color mode with maxiter 150, and have used the palette editor to set all 256 possible colors for use with color cycling, then you will want to set the '# of colors' to 256.
See the Recordcolors command, which controls when mapfiles are used and when compressed colors are written to PAR files.
maxlinelength: This number controls the maximum width of a parameter entry in a PAR file. The default is 72 characters.
At the bottom of the input screen are inputs for FractInt's 'pieces' divide-and-conquer feature. You can create multiple PAR entries that break an image up into pieces so that you can generate the image pieces one by one. There are two reasons for doing this. The first is in case the fractal is very slow, and you want to generate parts of the image at the same time on several computers. The second is that you might want to make an image greater than 2048 x 2048, the old pixel limit for FractInt. The parameters for this feature are:
X Multiples - How many divisions of final image in the x direction Y Multiples - How many divisions of final image in the y direction Video mode - FractInt video mode for each piece (e.g. 'F3')
The last item defaults to the current video mode. If either X Multiples or Y Multiples are greater than 1, then multiple numbered PAR entries for the pieces are added to the PAR file, and a MAKEMIG.BAT file is created that builds all of the component pieces and then stitches them together into a 'multi-image' GIF. The current limitations of the 'divide and conquer' algorithm are 36 or fewer X and Y multiples (so you are limited to 'only' 36x36=1296 component images), and a final resolution limit in both the X and Y directions of 65,535 (a limitation of 'only' four billion pixels or so).
The final image generated by MAKEMIG is a 'multi-image' GIF file called FRACTMIG.GIF. In case you have other software that cannot handle multi-image GIF files, MAKEMIG includes a final (but commented out) call to SIMPLGIF, a companion program that reads a GIF file that may contain little tricks like multiple images and creates a simple GIF from it. Fair warning: SIMPLGIF needs room to build a composite image while it works, and it does that using a temporary disk file equal to the size of the final image - and a 64Kx64K GIF image requires a 4GB temporary disk file!
The [G] command lets you give a startup parameter interactively.
- [@] or 
- '3D' Commands
See '3D' Images for details of these commands.
Restore a saved image as a 3D 'landscape', translating its color information into 'height'. You will be prompted for all KINDS of options.
- [#] Restore in 3D and overlay the result on the current screen.
- Interrupting and Resuming
FractInt command keys can be loosely grouped as:
Keys which suspend calculation of the current image (if one is being
calculated) and automatically resume after the function.
[Tab] (display status information) and [F1]
(display help), are the only keys in this group.
Keys which automatically trigger calculation of a new image.
Examples: selecting a video mode (e.g. [F3]); selecting
a fractaltype using [T]; using the [X] screen to
change an option such as maximum iterations.
- Keys which do something, then wait for you to indicate what to do next. Examples: [M] to go to main menu; [C] to enter color cycling mode; [PageUp] to bring up a zoom box. After using a command in this group, calculation automatically resumes when you return from the function (e.g. [Esc] from color cycling, [PageDn] to clear zoom box). There are a few fractal types which cannot resume calculation, they are noted below. Note that after saving an image with [S], you must press [Enter] to clear the 'saved' message from the screen and resume.
An image which is [S]aved before it completes can later be [R]estored and continued. The calculation is automatically resumed when you restore such an image.
When a slow fractal type resumes after an interruption in the third category above, there may be a lag while nothing visible happens. This is because most cases of resume restart at the beginning of a screen line. If unsure, you can check whether calculation has resumed with the [Tab] key.
The following fractal types cannot (currently) be resumed: plasma, 3d transformations, julibrot, and 3d orbital types like lorenz3d. To check whether resuming an image is possible, use the [Tab] key while it is calculating. It is resumable unless there is a note under the fractal type saying it is not.
The Batch Mode section discusses how to resume in batch mode.
To [R]estore and resume a 'formula', 'lsystem', or 'ifs' type fractal your 'formulafile', 'lfile', or 'ifsfile' must contain the required name.
- Keys which suspend calculation of the current image (if one is being calculated) and automatically resume after the function. [Tab] (display status information) and [F1] (display help), are the only keys in this group.
- Orbits Window
The [O] key turns on the Orbit mode. In this mode a cursor appears overthe fractal. A window appears showing the orbit used in the calculation of the color at the point where the cursor is. Move the cursor around the fractal using the arrow keys or the mouse and watch the orbits change. Try entering the Orbits mode with View Windows ([V]) turned on. The following keys take effect in Orbits mode.
[c] Circle toggle - makes little circles with radii inversely proportional to the iteration. Press [c] again to toggle back to point-by-point display of orbits. [l] Line toggle - connects orbits with lines (can use with [c]) [n] Numbers toggle - shows complex coordinates and color number of the cursor on the screen. Press [n] again to turn off numbers. [p] Enter pixel coordinates directly [h] Hide fractal toggle. Works only if View Windows is turned on and set for a small window (such as the default size.) Hides the fractal, allowing the orbit to take up the whole screen. Press [h] again to uncover the fractal. [s] Saves the fractal, cursor, orbits, and numbers as they appear on the screen. [<] or [,] Zoom orbits image smaller [>] or [.] Zoom orbits image larger [z] Restore default zoom.
- View Window
The [V] command is used to set the view window parameters described below. These parameters can be used to:
- Define a small window on the screen which is to contain the generated images. Using a small window speeds up calculation time (there are fewer pixels to generate). You can use a small window to explore quickly, then turn the view window off to recalculate the image at full screen size.
- Generate an image with a different 'aspect ratio'; e.g. in a square window or in a tall skinny rectangle.
- View saved GIF images which have pixel dimensions different from any mode supported by your hardware. This use of view windows occurs automatically when you restore such an image.
- 'Preview display'
Set this to 'yes' to turn on view window, 'no' for full screen display. While this is 'no', the only view parameter which has any affect is 'final media aspect ratio'. When a view window is being used, all other FractInt functions continue to operate normally - you can zoom, color-cycle, and all the rest.
- 'Reduction factor'
When an explicit size is not given, this determines the view window size, as a factor of the screen size. E.g. a reduction factor of 2 makes the window 1/2 as big as the screen in both dimensions.
- 'Final media aspect ratio'
This is the height of the final image you want, divided by the width. The default is 0.75 because standard PC monitors have a height:width ratio of 3:4. E.g. set this to 2.0 for an image twice as high as it is wide. The effect of this parameter is visible only when 'preview display' is enabled. If the explicit size of both x and y are set, setting this value to 0 will cause the appropriate value to be calculated based on x and y.
- 'Crop starting coordinates'
This parameter affects what happens when you change the aspect ratio. If set to 'no', then when you change aspect ratio, the prior image will be squeezed or stretched to fit into the new shape. If set to 'yes', the prior image is 'cropped' to avoid squeezing or stretching.
- 'Explicit size'
Setting these to non-zero values over-rides the 'reduction factor' with explicit sizes in pixels. If only the 'x pixels' size is specified, the 'y pixels' size is calculated automatically based on x and the aspect ratio.
More about final aspect ratio: If you want to produce a high quality hard-copy image which is say 8" high by 5" down, based on a vertical 'slice' of an existing image, you could use a procedure like the following. You will need some method of converting a GIF image to your final media (slide or whatever) - FractInt can only do the whole job with a PostScript printer, it does not preserve aspect ratio with other printers.
restore the existing image
- set view parameters: preview to yes, reduction to anything (say 2), aspect ratio to 1.6, and crop to yes
- zoom, rotate, whatever, till you get the desired final image
- set preview display back to no
- trigger final calculation in some high res disk video mode, using the appropriate video mode function key
- print directly to a PostScript printer, or save the result as a GIF file and use external utilities to convert to hard copy.
- Video Mode Function Keys
FractInt supports *so* many video modes that we have given up trying to reserve a keyboard combination for each of them.
Any supported video mode can be selected by going to the 'Select Video Mode' screen (from main menu or by using [Delete]), then using the cursor up and down arrow keys and/or [PageUp] and [PageDown] keys to highlight the desired mode, then pressing [Enter].
Up to 39 modes can be assigned to the keys F2-F10, SF1-SF10 [Shift] + [Fn]), CF1-CF10 ([Ctrl] + [Fn]), and AF1-AF10 ([Alt] + [Fn]). The modes assigned to function keys can be invoked directly by pressing the assigned key, without going to the video mode selection screen.
30 key combinations can be reassigned: [F1] to [F10] combined with any of [Shift], [Ctrl], or [Alt]. The video modes assigned to [F2] through [F10] can not be changed - these are assigned to the most common video modes, which might be used in demonstration files or batches.
To reassign a function key to a mode you often use, go to the 'select video mode' screen, highlight the video mode, press the keypad (gray) [+] key, then press the desired function key or key combination. The new key assignment will be remembered for future runs.
To unassign a key (so that it does not invoke any video mode), highlight the mode currently selected by the key and press the keypad (gray) [-] key.
A note about the 'select video modes' screen: the video modes which are displayed with a [B] suffix in the number of colors are modes which have no custom programming - they use the BIOS and are S-L-O-W ones.
See 'Video Adapter Notes' for comments about particular adapters.
See 'Disk-Video' Modes for a description of these non-display modes.
See 'Customized Video Modes, FRACTINT.CFG' for information about adding your own video modes.
- Browse Commands
The following keystrokes function while browsing an image:
- [ARROW KEYS] Step through the outlines on the screen.
- [ENTER] Selects the image to display.
- [\],[h] Recalls the last image selected.
- [D] Deletes the selected file.
- [R] Renames the selected file.
- [s] Saves the current image with the browser boxes displayed.
- [ESC] , [l] Toggles the browse mode off.
- [Ctrl-b] Brings up the Browser Parameters screen.
- [Ctrl-Ins/Del] Change the browser boxes color.
This is a 'visual directory', here is how it works... When [L] or [l] is pressed from a fractal display the current directory is searched for any saved files that are deeper zooms of the current image and their position shown on screen by a box (or crosshairs if the box would be too small). See also Browser Parameters for more on how this is done.
One outline flashes, the selected outline can be changed by using the cursor keys. At the moment the outlines are selected in the order that they appear in your directory, so do not worry if the flashing window jumps all over the place! When enter is pressed, the selected image is loaded. In this mode a stack of the last sixteen selected filenames is maintained and the [\] or [h] key pops and loads the last image you were looking at. Using this it is possible to set up sequences of images that allow easy exploration of your favorite fractal without having to wait for recalc once the level of zoom gets too high, great for demos! (also useful for keeping track of just exactly where fract532.gif came from :-) )
You can also use this facility to tidy up your disk: by typing UPPER CASE [D] when a file is selected the browser will delete the file for you, after making sure that you really mean it, you must reply to the 'are you sure' prompts with an UPPER CASE [Y and nothing else, otherwise the command is ignored. Just to make absolutely sure you do not accidentally wipe out the fruits of many hours of cpu time the default setting is to have the browser prompt you twice, you can disable the second prompt within the parameters screen, however, if you are feeling overconfident :-).
To complement the Delete function there is a rename function, use the UPPER CASE [R] key for this. You need to enter the FULL new file name, no .GIF is implied.
It is possible to save the current image along with all of the displayed boxes indicating subimages by pressing the [s] key. This exits the browse mode to save the image and the boxes become a permanent part of the image. Currently, the screen image ends up with stray dots colored after it is saved.
Esc backs out of image selecting mode.
The browser can now use expanded memory or extended memory. If you have more than 4 MB of expanded/extended memory available, you can use either. If you do not have 4 MB of expanded/extended memory available, use expanded memory as it will allocate as much as possible. The extended memory support will silently fail and default to the use of far memory if 4 MB of extended memory is not available.
Here is a tip on how to zoom out beyond your starting point when browsing: Suppose you restore a fractal deeply-zoomed down in a directory of related zoomed images, and then bring up the browser. How do you zoom out? You cannot use "\" because you started with the zoomed image, and there is no browser command to detect the next outer image. What you can do is exit the browser, press PgUp until the zoom box will not get any smaller, zoom out with Ctrl-Enter, and before any image starts to develop, call up the browser again, locate your zoomed image that you started with, and see if there is another image that contains it - if so, restore it with the browser.You can also use a view window [v] to load the first image, and then use the browser.
'Sorry... I cannot find anything' The browser cannot locate any files which match the file name mask. See Browser Parameters This is also displayed if you have less than 10K of far memory free when you run FractInt.
'Sorry.... no more space' At the moment the browser can only cope with 450 sub images at one time. Any subsequent images are ignored, make sure that the minimum image size is not set too small on the parameters screen.
'Sorry.... out of memory' The browser has run out of far, expanded, or extended memory in which to store the pixels covered by the sub image boxes. Try again with the main image at lower resolution, and/or reduce the number of TSRs resident in memory when you start FractInt. Make sure you have expanded or extended memory available.
'Sorry... it is a read only file, cannot del [filename]'
'Sorry.... cannot rename'
The file which you were trying to delete or rename has the read only attribute set, you will need to reset this with your operating system before you can get rid of it.
- Evolver Commands
PageUp When no Zoom Box is active, brings one up. When Zoom Box is active already, shrinks it. PageDown Expands the Zoom Box. Expanding past the screen size cancels the Zoom Box. Arrow key Pans (Moves) the Zoom Box. Ctrl-Arrow key Moves the Zoom Box to the next subimage. Enter Redraws the Screen or area inside the Zoom Box. Ctrl-Enter 'Zoom-out' - expands the image so that your current image is positioned inside the current zoom-box location. Ctrl-Pad+/Pad- Rotates the inner Zoom Box. Ctrl-PgUp/PgDn Changes inner Zoom Box vertical size. Ctrl-Home/End Changes inner Zoom Box shape. Ctrl-Ins/Del Changes inner Zoom Box color. Ctrl-E Brings up the evolver screen. Space Brings up the evolver screen once in evolver mode. B Turns off evolver if in evolver mode. F2 Halves the amount of mutation. F3 Doubles the amount of mutation. F4 Generates fewer, bigger images. F5 Generates more, smaller images. F6 Switches to/from 'spread' mode with fewer mutations around the middle.
For more about the Explorer/Evolver, see the Explorer/Evolver Documentation.
- RDS Commands
The following keystrokes function while viewing an RDS image:
[Enter] or [Space] -- Toggle calibration bars on and off. [Ctrl-s] or [k] -- Return to RDS Parameters Screen. [s] -- Save RDS image, then restore original. [c], [+], [-] -- Color cycle RDS image. Other keys -- Exit RDS mode, restore original image, and pass keystroke on to main menu.
For more about RDS, see Random Dot Stereograms (RDS)