XScreenSaver(1)

NAME
       rocks - animation of flying through an asteroid field

SYNOPSIS
       rocks  [-display  host:display.screen] [-foreground color]
       [-background color] [-window] [-root] [-mono] [-ncolors n]
       [-install]   [-visual  visual]  [-count  integer]  [-delay
       usecs] [-speed integer] [-norotate] [-nomove] [-3d]

DESCRIPTION
       The rocks program draws an animation of an asteroid  field
       moving  past  the observer (or vice versa).  Sometimes the
       observer picks up spin on Z axis.

OPTIONS
       rocks accepts the following options:

       -window Draw on  a  newly-created  window.   This  is  the
               default.

       -root   Draw on the root window.

       -mono   Make all the rocks the same color.

       -ncolors colors
               How  many  different  colors  to  use.  Default 5.
               Colors are chosen randomly.

       -install
               Install a private colormap for the window.

       -visual visual
               Specify which visual to use.  Legal values are the
               name  of a visual class, or the id number (decimal
               or hex) of a specific visual.

       -count integer
               Maximum number of rocks to draw on the  screen  at
               once.  Default 100.

       -speed integer
               A measure of the speed with which the observer and
               the rocks pass each other, from 1 to 100.  Default
               100,  meaning  ``very fast.''  If you're on a slow
               display connection  (the  animation  looks  jerky)
               then   try  making  this  number  smaller,  and/or
               decreasing the number of rocks.

       -delay microseconds
               Number  of  microseconds  to  delay  between  each
               frame.   Default  50000, meaning about 1/20th sec-
               ond.  Compare and contrast with -speed, above.

       -norotate
               Don't rotate the observer; just  fly  through  the
               field on the level.

       -nomove Don't  turn  the observer; just fly straight ahead
               through the field.

       -3d     Do red/blue 3d separations: if  you  look  at  the
               screen  with 3d glasses, the rocks will be jumping
               right out at you.  Oooooh, scaaary!

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.

SEE ALSO
       X(1) xscreensaver(1) 

BUGS
       There should be an option  to  display  doppler  shift  (a
       gravity rainbow.)

       Speed of rotation should be settable.

       Default  speed  of  rotation should be relative to forward
       velocity.

COPYRIGHT
       Copyright (C) 1992 by Jamie Zawinski.  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
       Based on Lisp Machine  code  copyright  1988  John  Nguyen
       lt;johnn@hx.lcs.mit.edu.

       Ported  to  C  and X by Jamie Zawinski lt;jwz@netscape.com,
       13-aug-92.

       Steering  code  by  Jeremie  Petit;  3D  code  by   theil-
       ing@coli.uni-sb.de.