NAME

fractal, julia − Display Mandelbrot and Julia sets on Amiga Unix /dev/screen device

SYNOPSIS

fractal [-?JMbB] [-xyiIpPqaeHWDhwdmf float]

DESCRIPTION

fractal commands have changed from the previous release.  New mouse and key hacks are available.  fractal by default opens the largest possible screen on the default monitor under the screens device (/dev/screen).  fractal proceeds to display a Mandelbrot for the current coordinates. 

OPTIONS

J Julia computation. 

M Mandelbrot computation

x float
X (real component of Z) center of fractal to compute.

y float
Y (imaginary component of Z) center of fractal to compute.

i float X interation increment. 

I float
Y interation increment.

p float
real componant of C.

q imaginary component of C. 

a Attractor point.  Interration of Z = Z^2 + C will stop when Z is greater than a. 

e Escape point or max interrations.  Interration of Z = Z^2 + C will terminate if the interration number exceeds e. 

w Actual screen width. 

h Actual screen height. 

d Actual screen depth. 

f scrtype flags (see screen(1A)). 

m scrtype modes (see screen(1A)). 

W Virtual screen width. 

H Virtual screen height. 

D Virtual screen depth. 

B Batch mode (no display, save on exit)

b Same as ‘B’ (batch mode) but will display screen while fractal is being computed. 

F Filename for Amiga-s (save gif file) key hack. 

MOUSE HACKS

To zoom into the fractal drag a box around the part of the fractal you wish to display.  If the SHIFT key is held down while dragging the mouse the box will not be contrained to square sides. 
 
If a zoom box is displayed and CONTROL key is held down while dragging the mouse the zoom box will move.  If no zoom box is display the screen will move around the virtual screen (see command line options -H, -W, and -D).
 
Use Amiga-z (or the RETURN key) to zoom in, Amiga-Z to zoom out.
 
Use ESC to terminate zoom box mode.

KEY HACKS

Most key hacks are now modified by the Amiga-key. 

Amiga-q
Quit fractal.

ESC Quit a zoom grab. 

Amiga-c
Change the color map.  See the section COLORS for more information. 

TAB Toggle color cycling. 

Amiga-s
Save fractal as frac.gif in current directory.

Amiga-j
Redraw the Julia Set that corresonds to the position of the pointer. (only valid while drawing a Mandlebrot Set).

Amiga-m
Redraw the Mandelbrot Set that corresonds to the position of the pointer. (only valid while drawing a Julia Set).

Amiga-w
Write out a gif file of the current screen using the current name given on the command line with the -F argument.

COLOR

While in color mode you can use the pointer to click on one of the color boxs representing your current color palette and change it by selecting the color in the color selection box to the left or by dragging the red, green, and blue slide gadgets at the bottom of the screen that correspond to red, green, and blue color intensities.  Use the Return Key to return the fractal with the new colors installed.  Use ESC to abort. 

NOTES

This version of Fractal has a better user interface then the previous version but it still need work.  If you’d like to work on it--do it.  Please send me any hacks you have for it. 

Partial hacks are in for raising Z to an arbitrary power.  I did not have time to finish this so the code lay in NEWcompute.c in the source directory.  It is slow as a dog. 

There needs to be a text interface to dump and modify the current fractal coordinates.  This was deemed to hairy for 2.0. 

I ment to fix up a 4-d fractal render program.  There is a simple attempt called fracslice and is in the source directory.  Maybe someone can use it. 

scrcols (the color selection) is actually a separate program. You may use it to set your text screen, cursor colors.  scrcols has problems on systems that by default use overscan. 

Someday I will write a decent manual page. 

AUTHOR

Keith M. Gabryelski (ag@amix.commodore.com)

This program was written for my wife, Laura, and Bexley, my son.  Peace. 

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