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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.