Amiga Computing - Commodore Is Awesome

• AMOS Simple sprite
plotter instructions •
THIS program is a simple utility that
allows you to take AMOS sprites and
paste them onto an IFF screen ready
for loading into Deluxe Paint, or
porting over to another computer -
1 (such MIPas
the Atari ST)_ The program
also draws a border around the sprite..
iiThe controls are pretty simple — oncel
you have loaded a sprite bank that ist
, KEY USE
+ Moves to next sprite in
bank.
Moves back one sprite,
Changes the sprite border
colour register (adds one),
Changes the sprite border
colour register (decs one).
Loads a new sprite bank
(but does not clear the 0
screen).
Saves the picture in IFF
format.
Clears the screen.
A simple undo feature. Be
careful, once pressed there
is no way of going back.
o Quits back to AMOS.
If you press left and right mouse
button (in that order) the current bot?
Lill be pasted ACEMMLonto
the screen. 411
tions.
I know it sounds a little complex but it
really is flexible. Let's try an example —
remember to type this EXACTLY as
shown here:
ANAL 14ove 16,0,1" ANAL ON 1
You will see that the geezer we set up
earlier has moved smoothly from his
origin (50,50) across 16 pixels in one
pixel increments. Try this one:
ANAL 1.•5ove 16,0,4* : ANAL ON 1
It moved a little faster this time
because we changed the last parameter
in the Move command. It is a little like
saying "Move the object 16 pixels, but
want it done in four separate goes."
OK, last example for this bit :
ANAL 1,"Mwe 16,0,16' : ANAL CN 1
If you have managed to follow what I
have been saying you will realise that
our little geezer has just moved 16
pixels in increments of 16 pixels.
I hope you have now mastered the
simple techniques required to produce
fun moving characters. Remember that,
as my mate Aaron Fothergill (editor of
the AMOS club magazine), always
says: "No program is fixed, you should
1
always get lots of people to try it out
and tweak it accordingly."
Now we are running out of room for
this issue, so lets cover a little animation.
The animation command in AMAL
has a very simple structure. Type this in
direct mode:
AMAL 1, 'Anim 0, (1,4)12,41 (3,4) (2,4) (1,0 •
ANAL ON I
Our little geezer should be waving his
dinky legs like there is no tomorrow. As
you can see, we first put an Anim
command in the string (with its first
letter in capitals) followed immediately
by the amount of times you wish to
repeat the animation. If you put a zero
the animation will repeat indefinitely.
The next parameters are the actual
animation numbers, these are stored in
brackets and consist of the image
number of the frame stored in the
SPRITE/BOB bank followed by a
comma and then the time you wish to
elaps before the next animation frame is
displayed.
Well,' hope that hasn't put you off
AMAL 'cos next time we are going to
tackle joystick—controlled animation_
The programs on the Cover Disk this
month are slightly more advanced
versions of the routines we have been
looking at here, containing a mixture of
animation and movement commands.
Also on there is the moving rainbow
for our game background (all done
using AMAL). I didn't quite have room to
fit it into this month's column so it will
have to wait.
As if that wasn't enough for people
who have got the V1.2 upgrade, there is
a little program on the cover disk which
will show you how to save memory by
using the new SPRITE flipping routines.
See if you can produce some good
little demo between now and the next
issue, if you do why not put then into
the public domain so that all AMOS
users can see them?
Before I go, if anybody from the
RSPCA is reading this column I would
just like to report Richard \tanner of
Database Software for not feeding his
cat until he got home at 2 o'clock on
Tuesday September llth.
This was due to a few last minute
bugs (now corrected) in the Over 7s
part of Fun School 3!
Peter Hickman
irons out a
few bugs and
takes a look
at the unique
animation
language
which makes
AMOS so
special
Next month we will cover some of
the intermediate level features of
AMAL, including joystick control
and synchronised movement and
animation.