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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.