Ñ                       HINTS AND TIPS PART II

                        ----------------------
Ð
Before , in  part  I  I  talked  about  updating  things  at different
intervals. Another way to get speed is to use AMAL. Amal speeds things
up ten fold and I don't  think  Blitz  2 has a complex speedy Interupt
laungage! With MouthMan there  were  very  few  objects  on the screen
which need moving. The same can be said for most games though. Even in
R-Type clone you can use one  channel  for  the scrolling, One for the
ship and one for the  bullet  and  then  have the other channels doing
Aliens.

In Mouth Man the Maximum number of Aliens which will be on the screen
is about 6. Two Animation channels are assigned to here, one to update
him and one to move him. It may seem strange to do this but there is a
reason for this. Channel 2 handles moving the mouth on screen. Channel
1 however does a looping  animation  of  a  mouth opening and closing.
When the hero collects a  mighty  mouth  bonus  or morphs into another
object to fight a boss it changes  the animation. Instead of having to
have the move routine boxed in to  each  new AMAL string all I need to
do is change the AMAL which animates the mouth only.

Using AMAL IS very  important  for  speed.  A  first  I  found it very
complicated and tended to shun it. But to get the speed needed AMAL is
essential. Also ypu don't have to do as  much work with AMAL as you do
with AMOS basic commands. For Example in a simple game called TimeWars
I was writing for DidsMag it occured to me that it was essential. Type
in both these examples.
¦
' EXAMPLE 1: UPDATING MANUALLY A BOB
'
LOAD "WAC:DIDSTUT_BOBS.Abk",1
CLS 0
FLASH OFF
GET SPRITE PALETTE
'
X=0
Y=0
I=1
WAY=1
'
DOUBLE BUFFER
'
DO
IF WAY=1
INC X
IF X=320
WAY=2
END IF
END IF
IF WAY=2
I=2
DEC X
END IF
IF FIRE(1)
FOR I=1 TO 5
SHOOT:WAIT 5:SHOOT
NEXT I
WAIT 5
END IF
BOB 1,X,Y,I
WAIT VBL
LOOP
Ï'
But to move a ship backwards  and  forawrds  and still have the sounds
right (by waiting 5 between each shot)  doing it in AMAL is easier and
better. Notice in the above  example  that  the ship stops moving when
ever fire is pressed. Now type in the Amal Example:

' AMAL EXAMPLE
'
LOAD "DIDSTUT_BOBS.ABK",1:CLS  0:FLASH  OFF:GET  SPRITE PALETTE:DOUBLE
BUFFER
BOB 1,0,50,1:CHANNEL 1 TO BOB 1
AMAL 1,"ANIM 1,(1,1); MOVE 320,0,320 ;ANIM 1,(2,1); MOVE -320,0,320;"
AMAL ON 1
DO
IF FIRE(1)
FOR I=1 TO 5
SHOOT:WAIT 5:SHOOT
NEXT I
WAIT 5
END IF
WAIT VBL
LOOP
'
Again this text  file  may  be  a  bit  long  for  the  WAC engine,its
certainly to long for the  DidsMag  engine!  But notice when you press
fire it does  not  stop  the  ship  dead  for  split  second  which is
noticeable.

If Paul Wants me to continue these hints for WAC next time I write for WAC
it will be on Parallax scrolling!

Richard Martin.