Provided by: xscreensaver-gl-extra_5.36-1ubuntu1_amd64 
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 © 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.