Provided by: xscreensaver-gl-extra_5.15-2ubuntu1_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 the current frame rate, CPU load, and polygon count.

       -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 (C) 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.