2.48 Ant Automaton
(type=ant)
This fractal type is the generalized Ant Automaton described in the
"Computer Recreations" column of the July 1994 Scientific American. The
article attributes this automaton to Greg Turk of Stanford University,
Leonid A. Bunivomitch of the Georgia Institute of Technology, and S. E.
Troubetzkoy of the University of Bielefeld.
The ant wanders around the screen, starting at the middle. A rule
string, which the user can input as Fractint's first parameter,
determines the ant's direction. This rule string is stored as a double
precision number in our implementation. Only the digit 1 is significant
-- all other digits are treated as 0. When the type 1 ant leaves a cell
(a pixel on the screen) of color k, it turns right if the kth symbol in
the rule string is a 1, or left otherwise. Then the color in the
abandoned cell is incremented. The type 2 ant uses only the rule string
to move around. If the digit of the rule string is a 1, the ant turns
right and puts a zero in current cell, otherwise it turns left and put a
number in the current cell. An empty rule string causes the rule to be
generated randomly.
Fractint's 2nd parameter is a maximum iteration to guarantee that the
fractal will terminate.
The 3rd parameter is the number of ants (up to 256). If you select 0
ants, then the number oif ants is random.
The 4th paramter allows you to select ant type 1 (the original), or type
2.
The 5th parameter determines whether the ant's progress stops when the
edge of the screen is reaches (as in the original implementation), or
whether the ant's path wraps to the opposite side of the screen. You can
slow down the ant to see her better using the <p> screen Orbit Delay -
try 10.
The 6th parameter accepts a random seed, allowing you to duplicate
images using random values (empty rule string or 0 maximum ants.
Try rule string 10. In this case, the ant moves in a seemingly random
pattern, then suddenly marches off in a straight line. This happens for
many other rule strings. The default 1100 produces symmetrical images.
If the screen initially contains an image, the path of the ant changes.
To try this, generate a fractal, and press <Ctrl-a>. Note that images
seeded with an image are not (yet) reproducible in PAR files. When
started using the <Ctrl-a> keys, after the ant is finished the default
fractal type reverts to that of the underlying fractal.
Special keystrokes are in effect during the ant's march. The <space> key
toggles a step-by-step mode. When in this mode, press <enter> to see
each step of the ant's progress. When orbit delay (on <p> screen) is set
to 1, the step mode is the default.
If you press the right or left arrow during the ant's journey, you can
adjust the orbit delay factor with the arrow keys (increment by 10) or
ctrl-arrow keys (increment by 100). Press any other key to get out of
the orbit delay adjustment mode. Higher values cause slower motion.
Changed values are not saved after the ant is finished, but you can set
the orbit delay value in advance from the <p> screen.