petri
Section: XScreenSaver manual (6)
Updated: 5.40 (12-Aug-2018)
Page Index
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] [-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.
- -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.
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 provided "as is" without express or
implied warranty.
AUTHOR
Dan Bornstein <
danfuzz@milk.com>, 06-Jul-2000.