Welcome to the sadness zone...

This program has been converted from an Archimedes program which for some
sad reason has become the only use for the aforesaid computer at school
(I suppose they can't do much else anyway).  It is totally pointless, but it
can be annoyingly addictive.

The program basically pours a particularly frothy liquid over a structure
you build with the mouse.  Like real water, it will go up a tube if it is
thin enough (1 pixel wide) and impressive fountains can be made.  There are
three modes: normal blue water, a mixture of red and blue water and blue
water followed by red water.

The left mouse button draws a thin line and the right mouse button draws
thicker.  DEL toggles the delete mode on/off and the right shift button will
also change it when pressed.  The mouse can be restricted to vertical
movement by pressing the up/down keys and horizontally by the left/right
arrow keys.  Other keys are:

Q - Quit (the most important!)
S - Start water
R - Reset: remove water from screen, S will restart
F - Freeze water
T - Thaw water
W - Wipe structure (well, wipe screen, but water is redisplayed)
I - Invert screen (try scribbling thick lines everywhere and pressing this
     for a bit of variety)

A red dot at the top of the screen marks the place the water springs from

To change the set-up you have to alter labels in source:
XORIGIN		- X coord of water start position (must be divisible by 8
		   Range is 8-312
YORIGIN 	- Y coord of water, range 1-254
NOOFDROPS	- As many as you like
STYLE		- Types of water:
		   0=Normal
		   1=Red/blue mixture
		   2=Red/blue seperate

Enjoy - if you can!

THE SOURCE
~~~~~~~~~~
First a note on the mouse pointer.  If you have run the program you will
have seen that when you are drawing the water stops.  This is because
putting the mouse controller in interrupts is too infrequent for drawing
unless the mouse moves VERY slowly (gaps appear otherwise).  The solution
is to move the mouse by interrupts only when moving liquid and when drawing
to call the routine as often as possible.  This change is not noticeable
when using the program.

The algorithm (nice word!) for the drop control is more or less copied from
the Archimedes version, the order is this:

	1. Move down if nothing is obstructing it
	2. If can't move down, check left and right
	   - If it is only possible to move in one direction, move that way
	   - If it could move either way use a bit of randomness to decide
	     which way to go.
	3. If it can't move either way, move up if possible (this produces
	   the froth and makes the water go up capillaries)

The randomness is acheived by using one of the four hardware times, timer A
of CIA-B.  If the timer is put into continuous mode then it will keep
counting down from a set number (it doesn't matter what).  The lowest bit
of this number will be random, or at the very least changes a lot - this bit
is bit 0 of CIABTALO (CIA-B Timer A LOw).

Each drop is stored individually in the following format:
DropAddr	LONG	Address of byte in 1st bitplane that drop is in
DropShift	BYTE	Bit number in that byte the drop is in (7-0)
DropFlags	BYTE	At the moment only bit 0 is used.  If bit 0=0 the
			drop is blue, if it=1 the drop is red.