.TH XScreenSaver 1 "06-Jul-2000" "X Version 11"
.SH NAME
petri - simulates mold growing in a petri dish
.SH SYNOPSIS
.B petri
[\-display \fIhost:display.screen\fP] [\-foreground \fIcolor\fP] [\-background \fIcolor\fP] [\-window] [\-root] [\-mono] [\-install] [\-visual \fIvisual\fP] [\-delay \fImicroseconds\fP] [\-size \fIinteger\fP] [\-mem-throttle \fIamount\fP] [\-count \fIinteger\fP] [\-originalcolors] [\-diaglim \fIreal\fP] [\-anychan \fIreal\fP] [\-minorchan \fIreal\fP] [\-instantdeathchan \fIreal\fP] [\-minlifespeed \fIreal\fP] [\-maxlifespeed \fIreal\fP] [\-mindeathspeed \fIreal\fP] [\-maxdeathspeed \fIreal\fP] [\-minlifespan \fIinteger\fP] [\-maxlifespan \fIinteger\fP]
[\-fps]
.SH DESCRIPTION
\fIpetri\fP 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).
.SH OPTIONS
.I petri
accepts the following options:
.TP 8
.B \-window
Draw on a newly-created window. This is the default.
.TP 8
.B \-root
Draw on the root window.
.TP 8
.B \-mono
If on a color display, pretend we're on a monochrome display.
.TP 8
.B \-install
Install a private colormap for the window.
.TP 8
.B \-visual \fIvisual\fP
Which visual to use. Legal values are the name of a visual class,
or the id number (decimal or hex) of a specific visual.
.TP 8
.B \-delay \fImicroseconds\fP
The interframe delay, in microseconds. Defaults to 10000, resource
\fIdelay\fP.
.TP 8
.B \-size \fIinteger\fP
The size of a cell in pixels. Defaults to 4, resource \fIsize\fP.
.TP 8
.B \-mem-throttle \fIamount\fP
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 \fImemThrottle\fP.
.TP 8
.B \-count \fIinteger\fP
How many different varieties of mold to grow (including Black Death).
Defaults to 8, resource \fIcount\fP.
.TP 8
.B \-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 \fIoriginalcolors\fP.
.TP 8
.B \-diaglim \fIreal\fP
The age limit for diagonal growth as a multiplier of
orthogonal growth (range 1..2). 1 means square growth, 1.414
(i.e., \fIsqrt(2)\fP) means approximately circular growth, 2 means
diamond growth. Defaults to 1.414, resource \fIdiaglim\fP.
.TP 8
.B \-anychan \fIreal\fP
The chance (range 0..1) that at each iteration, one or more
new cells will be born. Defaults to 0.0015, resource \fIanychan\fP.
.TP 8
.B \-minorchan \fIreal\fP
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 \fIminorchan\fP.
.TP 8
.B \-instantdeathchan \fIreal\fP
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 \fIinstantdeathchan\fP.
.TP 8
.B \-minlifespeed \fIreal\fP
The minimum speed for living cells as a fraction of the maximum possible
speed (range 0..1). Defaults to 0.04, resource \fIminlifespeed\fP.
.TP 8
.B \-maxlifespeed \fIreal\fP
The maximum speed for living cells as a fraction of the maximum possible
speed (range 0..1). Defaults to 0.13, resource \fImaxlifespeed\fP.
.TP 8
.B \-mindeathspeed \fIreal\fP
The minimum speed for Black Death cells as a fraction of the maximum possible
speed (range 0..1). Defaults to 0.42, resource \fImindeathspeed\fP.
.TP 8
.B \-maxdeathspeed \fIreal\fP
The maximum speed for Black Death cells as a fraction of the maximum possible
speed (range 0..1). Defaults to 0.46, resource \fImaxdeathspeed\fP.
.TP 8
.B \-minlifespan \fIinteger\fP
The minimum lifespan for a colony, in iterations, before Black Death
comes. Defaults to 500, resource \fIminlifespan\fP.
.TP 8
.B \-maxlifespan \fIinteger\fP
The maximum lifespan for a colony, in iterations, before Black Death
comes. Defaults to 1500, resource \fImaxlifespan\fP.
.TP 8
.B \-fps
Display the current frame rate and CPU load.
.SH ENVIRONMENT
.PP
.TP 8
.B DISPLAY
to get the default host and display number.
.TP 8
.B XENVIRONMENT
to get the name of a resource file that overrides the global resources
stored in the RESOURCE_MANAGER property.
.SH X RESOURCES
There are resource equivalents for each option, noted above.
.SH BUGS
There are no known bugs in
.I petri
as of this writing.
.SH SEE ALSO
.BR xscreensaver (1)
.SH COPYRIGHT
Copyright \(co 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.
.SH AUTHOR
Dan Bornstein <danfuzz@milk.com>, 06-Jul-2000.
