Provided by: xscreensaver-gl-extra_5.04-4ubuntu1_i386 bug

NAME

       crackberg  -  Lose  your  way  wandering  some height fields, and enjoy
       candy.

SYNOPSIS

       crackberg [-root] [-window] [-install]  [-display  host:display.screen]
       [-visual  visual] [-window-id id] [-delay usecs] [-fps] [-crack] [-lit]
       [-boring] [-letterbox] [-flat] [-wire] [-nowater]  [-visibility  float]
       [-color string] [-nsubdivs integer]

DESCRIPTION

       Flies  through  height maps, optionally animating the instantiation and
       destruction of generated tiles; by default,  tiles  ’grow’  into  place
       (height gradually increased up to correct value).  In windowed mode the
       following key controls are available:

       left, right
               Turn left and right.

       a,w,s,d Move left, forwards, backwards, and to the right, respectively.

       1,2     Decrease and increase manual speed, respectively.

       Spacebar
               Return to automatic control.

OPTIONS

       crackberg accepts the following options:

       -root   Draw on the root window.

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

       -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.

       -delay microseconds
               Delay between frames; default 20000 (1/50th of a second).

       -fps    Display frame per second and polygon counts.

       -crack  Use all possible methods to animate tile instantiation.

       -boring Do  not  animate  instatiation at all; use this to get standard
               landscape generator behavior.

       -letterbox
               Drawable window region has a 16:9 aspect ratio,  regardless  of
               actual window size.

       -lit    Enable lighting.

       -flat   Flat  shading  (OpenGL will use one color per primitive, rather
               than interpolating betwixt vertices).

       -wire   Wireframe.

       -nowater
               Do not display ’water’ (forces negative  values  to  zero,  and
               selects a different coloring method).

       -visibility float
               Value in range [0.2,1.0] (default 0.6) specifying proportion of
               viewable XY plane which is to be drawn upon.

       -color string
               Selects color scheme.   Use  with  no  or  bogus  argument  for
               current list.

       -nsubdivs integer
               Number  of times to recursively subdivide each triangular tile.
               Each increment increases total triangles by a factor of 4;  for
               instance  the  default  setting  4 results in 256 triangles per
               tile.

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.

SEE ALSO

       X(1), xscreensaver(1)

COPYRIGHT

       Copyright  © 2005 by Matus Telgarsky.  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

       Matus Telgarsky <catachresis@cmu.edu>, 2005.