This version of xfishtank is derived from Jim Rees, and contains the
following modifications and add-ons:

  - Let the fish swim in a transparent, click-through window.
  - Add a graphical user interface.
  - Use double-buffering for painting the fishes.
  - Make the program usable in xscreensaver.
  - Implementation of self-replication to re-create the source from 
    the binary. (see -selfrep in the man page);

Here follows the original text from Jim Rees and others:
   Notes: 
   - For installation, see the file INSTALL.
   - I removed emails and telephone numbers that are not relevant any more.


I've always liked this little program. An aquarium for your screen, with
fish swimming around on your desktop. It traces its history to the xfish
program, written around 1987 by John Bradley. Jonathan Greenblatt ported it
to X11 in 1988 and it made its way into the contributed program collection
by about X11R6. Eric Bina worked on the color maps and root window support
and added a lot more fish around 1992. TJ Phan added Truecolor support in
1996. Vincent Renardias contributed a man page, and Joey Hess packaged it up
for Debian.

When I learned xfishtank had been orphaned, I decided to adopt it, or at
least give it a decent home. I've tried to reflect the history in the git
log. If you know of intermediate versions not represented here, send them
along.

Pushed to github Feb 2012 by Jim Rees.

Build and install should go something like this:
tar xfvz xfishtank.tar.gz (or git clone the repo)
cd xfishtank
xmkmf
make
sudo make install

Here's the README as I found it.  Also see README.debian for more recent
history.


       ********************** FUN WITH FISH *********************

There are lots of programs for lots of platforms to make fish swim in the
background of your screen.  This is a modification of an old one called
xfish (also called Xaquarium), that I have added more features to.

To not confuse you (or confuse you more) I will call this modified xfish
"xfishtank". ['A rose by any other name...' and all that]


How is this different?  I started with you basic xfish, and I kept the
bubbles (actually I re-wrote some of the bubble code, but it LOOKS the same).
I changed the rest of the code to allow any number of multicolored fish to
swim around.  Each fish can have up to 255 colors, but on startup the program
takes all the colors from all the fish, and squeezes them down to all fit
into the default colormap as best it can.  Any fish can be any size in
width and height.  To make them look more like they are swimming, fish are
animated (Very simple 2 frame animation) [I got this idea from watching
the AfterDark fish on the Mac].  Fish CANNOT swim over each other, they
will turn around if they are about to collide.  I had a version that
had fish swiming over each other, it was WAY to slow to be something to run
on your background while working, so I deleted it.

xfishtank -help to see the command line options.


       ********************** NEW FUN WITH FISH *********************

Since the original version, I have received various comments and bug fixes.
This version I know runs on SGIs running 4.0, Sparcs running 4.1, 
Decstations running 4.1, and RS6000s running 3.1.  However, there were mongo
memory leaks in the X server distributed with the RS6000, so I had to compile
the X11R5 server and use that.

As you add more fish (especially very colorful fish) the total color use set
becomes quite large (greater than 255).  I added 2 new options to help you
deal with this.  By default xfishtank would find the total color use set
for all the fish you requested, and then start allocating out of the default
colormap until it filled up, it would then match the rest of the colors to
whatever colors it could get.  This first come first serve color allocation
can give really bad results for large color sets.  I added the -m option
to allow you to specify that the program should cut the color use set down
to the number you specify with the -m option before starting to allocate
out of the default colormap.  The algorithm used by -m is considerably better
than first come first serve.  Also, having xfishtank use ALL the available
cells in the default colormap can be bad.  The -C options lets you limit how
many cells xfishtank will take out of the default colormap.
In the first come first serve senario colors are allocated for the fish,
in the order of appearance in the FishList file, and then from the backgound
picture if one exists.

Finally, due to popular demand, I put back in my clipmask code.  By setting
the -d option (for Do clipping), xfishtank will swim its fish over whatever
you already have on your root window.  WARNING:  This will slow down your
machine!  The reason I took this code out originally was it slowed my 
machine down too much for me to comfortably work.  But if you think you have
a really spiffy fast workstation, go ahead and give it a try.

If you use the -d option and notice some flicker (which I expect you will),
this is because xfishtank is just doing an XClearArea, and letting the root
redraw its background.  If you know what you want your background picture to
be, use -p <image_file> instead of -d.  The image_file needs to be a gif
image.  Since xfishtank now knows what your background is, xfishtank with
the -p option should have much less flicker.  However, it suffers the
disadvantage that you can't change the background picture without restarting
xfishtank.

The intrepid explorer of the source code will notice that there are some
options not described in xfishtank -help.  In particular -o -and -D.  These
options aren't described because they were stuff I was fussing with and couldn't
get to work.  I left them in on this release so that if someone else wanted
to try and get them to work, they could see what I had already tried.  The -o
option lets fish try and swim on top of each other.  It looks ugly no matter
how I do it, if you can fix it, great.  -D is a special option that is only
active if you have also specified -d and -p.  Normally you never want to specify
both -d and -p because it doesn't make the animation any better, and it
slightly messes up fish to bubble intersections.  However, if you specify
-d -D -o -p you will get as close as I could get to proper fish intersections.
And when you see how crumby these are, and how slow it makes your machine
you will know why I gave up.

Ok, I'll fess up, I'm lying, I did actually get good fish to fish intersections
but only by writing a completely different version of xfishtank that has
each fish be a shaped override-redirect window, that moves itself, and changes
its shape-mask to animate.  This looks REALLY COOL, but grinds any and all
X servers to a complete standstill.


       ********************** NEW FISH PICTURES *********************

This release contains a grand total of 29 fish!  These fish were carefully
created through lots of hard work, and the help of many many people who
sent me pictures of fish, non-copyrighted gifs of fish, and allowed me to
borrow their scanners.  I'm not going to try and name them all here, there
are lots of you, and I'm afraid I may miss someone.  You all know who you are,
and you have my heartfelt thanks, I couldn't have done this without you.


       ********************** TROUBLE WITH FISH *********************

There is a scarcity of good fish pictures in the world, and they are all
protected by lawyers.  Here is the solution I propose.

Any of you with talent can edit up any pictures you want, somehow get them
into GIF format, and import them into your xfishtank.  The program
"giftofish" that I am supplying here takes as input any 2 GIF files,
and creates a xfishtank header file for that fish.  The 2 files must have
the same width and height, and must both have the same background color.
The pictures are assumed to be the two frames of an animated fish swiming right.
Put this new header file into your fishmaps directory, edit the FishList
file to add the prefix of that header file, and increment the total fishcount
on the first line of that file.  Now recompile xfishtank, and your new fish
will be used.  Also, the program fishtogif will extract the two gifs from
any fish header file so you can touch up what you already have.


            ********************** THANKS *********************

A really big thanks to well over 100 wonderful people who after downloading
the last version of xfishtank took the time to send me such pleasant,
complimentary, and supportive e-mail.  This version was never planned, but
all of you have made me feel better about writing this code than anything
that any employer has ever paid me for.

