ff-life.1

.Dd 2024-03-29
.Dt FF-LIFE 1
.Os farbfeld-utils
.Sh NAME
.Nm ff-life
.Nd farbfeld program that generates life-like cellular automata
.Sh SYNOPSIS
.Nm
<?rule?> <?steps?>
.Sh DESCRIPTION
.Nm
reads a
.Xr farbfeld 5
image from stdin, generates life-like cellular automata and writes the result to stdout.
.Pp
In case of an error
.Nm
writes a diagnostic message to stderr.
.Sh EXIT STATUS
.Bl -tag -width Ds
.It 0
Image processed successfully.
.It 1
An error occurred.
.El
.Sh OPTIONS
The program takes up to two arguments:
   - rule to use, in BS notation (default is B3/S23 which is Game of Life)
   - the number of steps (default 1)

Black cells are off, white cells are on, and transparent cells are permanently
off.
.Sh REFERENCES
https://en.wikipedia.org/wiki/Life-like_cellular_automaton
.br
https://www.jeremykun.com/2012/07/29/the-cellular-automaton-method-for-cave-generation/
.Sh PRACTICAL EXAMPLE
One example is cave generation, see the reference for some details about this.

Use
.Xr ff-gradient 1
with "n" mode for random data, then use
.Xr ff-poster 1
to change to 1-bit-per-level.

This looks like:
   $ ff-gradient 800 800 n42 000000 FFFFFF | ff-poster 1 > life-data.ff

Now you can apply the cellular automata.

The buttons described may be like the following:
   - Apply B678/S345678:
.Nm
B678/S345678 20
   - Apply B5678/S5678:
.Nm
B5678/S5678 1
   - Increase Resolution: ff-enlarge

Combining the above:
   $
.Nm
B678/S345678 20 < life-data.ff |
.Nm
B5678/S5678 | ff-enlarge > output.ff
.Sh EXAMPLES
$
.Nm
B678/S345678 20 < data.ff > life.ff
.Sh SEE ALSO
.Xr ff-conaut 1 ,
.Xr ff-critter 1 ,
.Xr ff-elementary 1 ,
.Xr ff-probaut 1 ,
.Xr ff-gradient 1 ,
.Xr ff-poster 1 ,
.Xr ff-enlarge 1 ,
.Xr farbfeld 5 ,
.Xr farbfeld-utils 7