XScreenSaver(1) 					      General Commands Manual						   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]  [-maxlifespeed  real]	[-mindeathspeed real] [-maxdeathspeed real] [-minlifespan integer]
       [-maxlifespan integer]

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 suf-
	       fix). 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  minlife-
	       speed.

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

       -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  min-
	       deathspeed.

       -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.

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 (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 sup-
       porting 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							    06-Jul-2000 						   XScreenSaver(1)