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1989-09-29
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===============================================================================
Mandelbrot/Julia set 2D/3D EGA/VGA Fractal Generator
Written by Tom Collins and Dan Rowley
(C) 1989 by Innovative Computer Solutions
Documentation for FRACT v3.0
===============================================================================
Shareware Notice
-------------------------------------------------------------------------------
This program is shareware. Please play with it for a few days. If you grow
attached to it, register it. If you sell computers/monitors/VGA cards, and
you use my program to show off the capabilities of such devices, I'd like you
to register FRACT. (Think about it this way, you're using my program to make
money. If it impresses someone enough to buy a VGA monitor/card, I think it's
worth it to you to send me a few bucks.)
[See the 'Registration' section at the end of this file for more info]
-------------------------------------------------------------------------------
You should have the following files on your disk:
FRACT.EXE - The actual Fractal Generator.
FRACT.DOC - This documentation.
FRACT.NEW - What's been changed from previous versions.
REGISTER.FRM - Registration form
????????.IMG
????????.DAT - Sample images and data files for use with FRACT
If any of these files are missing, please call one of the boards listed at the
end of this file to get a good copy. When redistributing this program, be sure
to include all of the above files.
-------------------------------------------------------------------------------
How to Use FRACT
-------------------------------------------------------------------------------
Any time the computer is drawing a image, hitting the 'S' key or the left
button on the mouse will save the image. Pressing the escape key or the right
mouse button will abort the image without saving it. If you save an image,
you'll be able to continue drawing it at another time.
Menu items and their associated functions:
Create a 2-D Mandelbrot image
-----------------------------
The program will ask you for the x (real) and y (imaginary) coordinates
corresponding to the center of the image. You will then be prompted for
the side length and the filename to save the image under. Leaving the
filename field blank will cause the image to be drawn without saving.
[Note: The Mandelbrot set is contained within the x coordinates (-2.1 and
+0.7) and the y coordinates (+1.4 and -1.4). You can create an image of
the Mandelbrot set by using the following data: x:-0.7, y:0, side:2.8.]
The image will be drawn with dots separated by progressively smaller
spaces. This should give you some idea of what the image will be like so
you can abort it early if you don't like it.
Create a 3-D Mandelbrot image
-----------------------------
The only difference between the 2-D and 3-D versions of the Mandelbrot
images is the method used to draw the image. The 3-D image is drawn with
diagonal lines starting from the upper right-hand corner.
Create a 2-D Julia image
------------------------
The program will ask you for the x and y coordinates corresponding to a
point on the Mandelbrot Set. This is the point from which the Julia set
will be drawn.
The Julia image will be drawn from both sides, as it is symmetric about
the origin.
Create a 3-D Julia image [registered version only]
--------------------------------------------------
Once again, the only difference between the 2-D and 3-D versions of the
Julia sets is the method used to draw the image. Like the 3-D Mandelbrot,
the 3-D Julia will be drawn with diagonal lines starting from the upper
right-hand corner.
Continue drawing an old image
-----------------------------
A list of available files will be displayed. After choosing a file, the
image will be loaded and the program will pick up from where it left off.
Hitting escape from the list of files will return you to the main menu.
Remove registration notices [registered version only]
-----------------------------------------------------
This option will remove the 'Register Your Software' message from a file
chosen from the file list.
Add extra sets of iterations
----------------------------
This feature is used to improve the quality of some images. Adding extra
iterations redraws black areas of the image, possibly adding more color.
Each set of iterations adds approximately 200 actual iterations to the
computations for each dot [the image starts out with 200 iterations].
Adding iterations will slow down the generation of the image, and it is
advised that you add at most 5 sets. [Note: Adding is cumulative.]
Load and view image
-------------------
You will once again go through the file selection menu. After choosing an
image it will be loaded and displayed on the screen [EGA images take
longer than VGA. VGA images will be faded onto the screen].
While the image is still on the screen the following options are
available:
Pressing 'X' will change to and from an 'X-ray' palette. This
occasionally produces some interesting effects.
Pressing the space bar will cause the palette to rotate giving the
illusion of movement. Pressing the space bar again will stop the
rotation. If you are using a mouse, pressing the left button will
start the palette changing and pressing the right button will stop
it. While holding the left button down, the speed of rotation can be
adjusted by moving the mouse horizontally.
Pressing escape or the 'Q' key will bring you back to the main menu.
Get info on an image
--------------------
This option will display pertinent information on any image you choose.
Zoom in to create a new image
-----------------------------
This option allows you to choose any point on an existing image and
magnify it to create a new image. Choose the point by using the arrow
keys/numeric keypad on the keyboard or the mouse. Clicking the left
mouse button, or pressing 'M' or Enter on the keyboard will create a
Mandelbrot image. Clicking the right mouse button, or pressing 'J' will
create the corresponding Julia Set for that point. When creating a new
Mandelbrot image you will be asked for a magnification factor [Note: 25
is a good factor]. When creating any image, you will also be asked for a
filename to save the image under.
Slide Show of all images [registered version only]
--------------------------------------------------
This option will cycle through all of the images in the current directory,
displaying and rotating the palette for a short period of time before
loading the next image. VGA images will fade in from black, and then fade
back to black after cycling. Press escape to abort the slide show.
Quit
----
Clears the screen and drops to DOS.
-------------------------------------------------------------------------------
History
-------------------------------------------------------------------------------
I've been interested in Fractal Geometry, especially the Mandelbrot Set, ever
since my father tried to write a program from algorithms appearing in the
August 1985 Scientific American Computer Recreations column. When I first saw
the program, it was on my Apple IIe. Written in BASIC, it plotted black and
white dots on the hi-res screen in a square of 100 pixels per side. I
modified the program to use the full screen (280x192) and the 5 colors that
Apple hi-res is limited to. I got bored fast, so I rewrote the program using
som