xphoon - displays the PHase of the mOON on the root window
] [-t interval
sets the X root window to a picture of the moon in its current
phase, including the partial lighting of the dark side by reflected
- Defeats the earthlight feature, forcing the dark side to be
- Have xphoon keep running and update the picture
every interval minutes. (Normally, xphoon just sets the root
picture and exits.)
- Forks a background process and prints the process-id to
stdout. Useful if you want to make menu commands to refresh or kill
- Rotate the whole picture 180 degrees, resulting in a moon
picture as viewed fom the Southern hemisphere.
- Demonstrate xphoon by rapidly stepping through moon
The original motivation for this program was that xsetroot was too slow.
Loading a full-screen bitmap took about 15 seconds. We made a trivial program
that had fullmoon.bitmap compiled in, and it ran in less than a second. (And
incidentally, the executable was smaller than fullmoon.xbm.) Then later we
came up with the phase hacking, the earthlight, and the auto-scaling.
Copyright (C) 1988, 1991 by Jef Poskanzer and Craig Leres.
The moon-phase computation is from "moontool.c" by John Walker.