XSWARM(6) XSWARM(6)
January 30, 1991
NAME
Xswarm Version 2.3 - X11 animated toy
SYNOPSIS
xswarm [-hq?vprVx] [-t timeout] [-D delay] [-g geometry] [-d
host:display] [-b bees] [-a bee-acceleration] [-s bee-velocity] [-A
wasp-acceleration] [-S wasp-velocity] [-B border-width] [-w wasp-color]
[-c bee-color] [-C background-color]
DESCRIPTION
Xswarm is an X11 client that animates a group of line segments. One
line is called the wasp and the others are the bees. The bees
constantly accelerate toward the wasp, forming a cute pattern that
continually changes. Because Xswarm is commonly left running in the
root window, it was made possible to control how much cpu time it uses
with the -d option. If a mouse button is pressed while the pointer is
in the xswarm window, the wasp becomes controlled by the mouse.
Control is released when the mouse button is pressed again. To kill
Xswarm , press q in it's window. The parameters that affect behavior
of the swarm are controllable by the user through command line
parameters. Some of the niftier features are controlling the wasp
with the mouse, putting it in the root window, using it as a screen
saver, and making the swarm fly "above" a background bitmap. After
playing with Xswarm interactively, one of it's common uses is in the
root window where it helps break the monotony of X. When putting it
there, don't forget to play with the -V and -x options! One of the
recently added capabilities of Xswarm is screen saving. If a non-zero
timeout is given with the -t option, the screen will be cleared after
the given amount of idle time and the swarm will animate until a key
is pressed or the mouse is moved. As far as I know, this is the first
example of an X screen saver other than the one built into the server.
By screen saver, I mean a program that does not require a signal from
the user to take over the screen.
OPTIONS
Xswarm has the following options:
-h, -q, -?
Display usage message and exit.
-v Display verbose information about the current settings.
-p Use the mouse (pointer) button to control the wasp. This can be
turned on and off at any time by pressing a button in the window.
-r Use root window.
-V Stay in the clear area of the root window. (Only useful with
-r.)
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XSWARM(6) XSWARM(6)
January 30, 1991
-x Use xor raster operation so that the bees don't destroy the root
bitmap. (Only useful with -r.)
-t timeout
This is the number of seconds of idle time to wait before
clearing the screen. The idle swarm disappears when a key is
pressed or the mouse is moved.
-D delay
This is the non-blocking delay between frames. (in milliseconds)
-g geometry
like -g 500x450+100+200
-d host:display
like -d spacsun:0.0 or -d unix:0.0
-b bees
This is the number of bees that will be flying around.
-a bee-acceleration
This is measured in pixels per frame per frame. (try 2-10)
-s bee-velocity
This is measured in pixels per frame. (try 5-20)
-A wasp-acceleration
This is measured in pixels per frame per frame. (try 2-10)
-S wasp-velocity
This is measured in pixels per frame. (try 5-20)
-w wasp-color
One of the colors in .../lib/X11/rgb.txt or a color of the form
#rrggbb in hexadecimal. For instance, #ef9595 is sort of a flesh
tone. r stands for red, g stands for green, and b stands for
blue.
-c bee-color
-C background-color
If you are using -x, then you may have to twiddle with this color
in order to get the bees to show up. (-x works well with black
and white)
EXAMPLES
For a swarm that doesn't stick so tightly to the wasp, try a larger
speed limit for the bees, like this... xswarm -s 16 For a wasp that
gets away more often, give the wasp a higher speed limit and better
acceleration, like this... xswarm -A 7 -S 20 To put the swarm in you
background without harming your root bitmap, do this... xswarm -r -x
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XSWARM(6) XSWARM(6)
January 30, 1991
-V You may need to fiddle with -w, -c, and -C to make the swarm
visible... xswarm -r -x -V -w red -c blue -C green To speed up the
swarm, decrease the delay between frames... xswarm -D 10 (Try taking
control with the mouse button.) To use xswarm as a screen saver, put a
line like this in your X startup script... xswarm -t 300 -w red -c
blue
BUGS
I still haven't gotten backing store to work perfectly in the root
window with the xor raster operation. Occasionally, the swarm leaves
a semi-permanent mark on the root window. If anyone is interested in
fixing up any part of xswarm, then please feel free, but I would like
a copy of the changes. Please let me know if you have any problems
with the screen saver feature. I have occasionally had the screen
saver window come up as a little puny window. It has also crashed
with an Xlib error. I hope I've fixed these problems but let me know
if they still exist. I can't figure out how to make xswarm notice an
f.delete command from the window manager. If you know how to detect
this then please let me know.
MISCELLANEOUS RAMBLINGS
Implementing the screen saver feature took alot of thinking. I would
be VERY interested in hearing of any other schemes for detecting user
inactivity. The way I did it seems a little messy to me, but here it
is. Initially, I traverse the entire window hierarchy. As I get to
each window, I do an XSelectInput() on it. Then when I want to watch
for user activity, I increment a timer and check for events. If there
are any events, then I zero the timer. If the timer exceeds whatever
the timeout is, then I toss up the screen saver window. Does anyone
have better ideas on how to watch for user activity in ALL windows
other than the way I described? I admit that I've gotten many ideas
from public domain software, but I've tried to give credit to the
original authors at least in the documentation. If you use any part
of xswarm or the swarm animation algorithm, then please include my
name in your man page/documentation somewhere.
AUTHOR
Xswarm's author is Jeff Butterworth (butterwo@cs.unc.edu). Looking at
the source code to psychoII helped me learn how to open a window.
Taking over the screen was surprisingly simple once I looked at the
source code for meltdown written by Dave Lemke (lemke@ncd.com). The
following people have helped immensely with bug fixes and suggestions:
David Elliott: tips for SYSV nap() and the sizehints structure
Karl Fox: improved the backing store problem
Arne Helme: fixed "nap" function for HP machines
Casey Leedom: supplied a simple imakefile and man page
Rob Nelson: added correct resizing
Andreas ?Stolcke?: fixed -g option, added virtual root
Bill Trost: explained the race condition in nap(), added mouse control
Jon Webb: bouncing against windows while in the root window
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XSWARM(6) XSWARM(6)
January 30, 1991
- 4 - Formatted: March 22, 2026
