XScreenSaver(r)                                   XScreenSaver(r)



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  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 (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(t)) 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(r)

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  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(r)