petri(6) XScreenSaver manual petri(6)

NAME

petri - simulates mold growing in a petri dish

SYNOPSIS

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

DESCRIPTION

petri simulates mold growing in a petri dish via a state-heavy 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.

--window-id number
Draw on the specified 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 (suffix "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 instantaneously. Defaults to 0.2,
resource instantdeathchan.

--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 fraction 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 fraction 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.

--fps Display the current frame rate and CPU load.

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_MANAGER property.

XSCREENSAVER_WINDOW
The window ID to use with --root.

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 (C) 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 provided "as is"
without express or implied warranty.

AUTHOR

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

X Version 11 6.09 (07-Jun-2024) petri(6)