xscreensaver(1)

NAME

petri - simulates mold growing in a petri dish

SYNOPSIS

petri  [-display  host:display.screen] [-foreground color]
[-background color] [-window] [-root]  [-mono]  [-install]
[-visual  visual]  [-delay  microseconds]  [-size integer]
[-mem-throttle amount] [-count integer]  [-originalcolors]
[-diaglim   real]   [-anychan   real]   [-minorchan  real]
[-instantdeathchan real] [-minlifespeed  real]  [-maxlife
speed  real]  [-mindeathspeed  real] [-maxdeathspeed real]
[-minlifespan integer] [-maxlifespan integer]

DESCRIPTION

petri simulates mold growing in a petri dish via a stateheavy grid of automata (vaguely like Conway's Life, only
with much more state per cell).

OPTIONS

petri accepts the following options:

-window Draw on a newly-created window. This is the

default.

-root Draw on the root window.

-mono If on a color display, pretend we're on a

monochrome display.

-install

Install a private colormap for the window.

-visual visual

Which visual to use. Legal values are the name of
a visual class, or the id number (decimal or hex)
of a specific visual.

-delay microseconds

The interframe delay, in microseconds. Defaults to
10000, resource delay.

-size integer

The size of a cell in pixels. Defaults to 4,
resource size.

-mem-throttle amount

The maximum amount of memory to consume, specified
either in megabytes (suffix "M"), kilobytes (suf
fix "K"), or bytes (sans suffix). In order to meet
the memory requirement, the cell size may be
increased. Defaults to 22M, resource memThrottle.

-count integer

How many different varieties of mold to grow
(including Black Death). Defaults to 8, resource
count.

-originalcolors

If specified, indicates that the colors used
should be the artist's original choices (a fixed
set of primary and secondary colors). In this
case, count must be 8 or less. Defaults to not
specified (i.e., false), resource originalcolors.

-diaglim real

The age limit for diagonal growth as a multiplier
of orthogonal growth (range 1..2). 1 means square
growth, 1.414 (i.e., sqrt(2)) means approximately circular growth, 2 means diamond growth. Defaults
to 1.414, resource diaglim.

-anychan real

The chance (range 0..1) that at each iteration,
one or more new cells will be born. Defaults to
0.0015, resource anychan.

-minorchan real

The chance (range 0..1) that, given that new cells
will be born, that only two will be added (hence
being a minor cell birth event). Defaults to 0.5,
resource minorchan.

-instantdeathchan real

The chance (range 0..1) that, given that death and
destruction will happen, that instead of using
Black Death cells, death will come instanta
neously. Defaults to 0.2, resource instant_ deathchan.

-minlifespeed real

The minimum speed for living cells as a fraction
of the maximum possible speed (range 0..1).
Defaults to 0.04, resource minlifespeed.

-maxlifespeed real

The maximum speed for living cells as a fraction
of the maximum possible speed (range 0..1).
Defaults to 0.13, resource maxlifespeed.

-mindeathspeed real

The minimum speed for Black Death cells as a frac
tion of the maximum possible speed (range 0..1).
Defaults to 0.42, resource mindeathspeed.

-maxdeathspeed real

The maximum speed for Black Death cells as a frac
tion of the maximum possible speed (range 0..1).
Defaults to 0.46, resource maxdeathspeed.

-minlifespan integer

The minimum lifespan for a colony, in iterations,
before Black Death comes. Defaults to 500,
resource minlifespan.

-maxlifespan integer

The maximum lifespan for a colony, in iterations,
before Black Death comes. Defaults to 1500,
resource maxlifespan.

ENVIRONMENT

DISPLAY to get the default host and display number.

XENVIRONMENT

to get the name of a resource file that overrides
the global resources stored in the RESOURCE_MAN
AGER property.

X RESOURCES

There are resource equivalents for each option, noted
above.

BUGS

There are no known bugs in petri as of this writing.

SEE ALSO

xscreensaver(1)

COPYRIGHT

Copyright © 1992-2000 by Dan Bornstein.

Permission to use, copy, modify, distribute, and sell this
software and its documentation for any purpose is hereby
granted without fee, provided that the above copyright
notice appear in all copies and that both that copyright
notice and this permission notice appear in supporting
documentation. No representations are made about the
suitability of this software for any purpose. It is pro
vided "as is" without express or implied warranty.

AUTHOR

Dan Bornstein <danfuzz@milk.com>, 06-Jul-2000.

X Version 11 06-Jul-2000 XScreenSaver(1)