A.N.A.L.O.G. ISSUE 27 / FEBRUARY 1985 / PAGE 43
Way back in the golden days, when issues of ANALOG Computing were still numbering in the teens, I wrote a program called Bounce. It appeared in the Our Game column in issue 15. At that time, I was fiddling with a fun new language for the Atari—Action! by Optimized Systems Software. I was thinking that a version of Bounce in Action! would be a worthwhile project.
Not long after I had that thought I discovered, to my amusement, that someone had beaten me to it. The friendly folks at ANALOG Computing told me one day that a certain David Plotkin had submitted a little ditty called Bounce in Action!, which later appeared in issue 20.
However, David’s idea of a better Bounce program was different from mine. His improvements consisted of adding GTIA color and, of course, speed (with Action!) to the original design. I enjoyed playing with David’s program, and I was pleased that someone else was as enthusiastic about Bounce as I was…I simply had another idea that had to be tried.
To me, the next natural step for Bounce is to add more discs—having multiple moving objects at your command makes Bounce about a million times more fun than the original. Of course, Action! is the only high-level language for the Atari that is fast enough to do a multiple-object Bounce effectively.
First there was Bounce, then Bounce in Action!, now I give you More Fun with Bounce (MFB for short).
I had other upgrading in mind, too. Tops on the list was user-friendliness. MFB lets you move the cursor around freely without upsetting the walls or the discs already laid down. Drawing or erasing occurs only when your joystick trigger is held down. To switch between the two functions (drawing and erasing), simply hit the SPACE BAR.
Another user-friendly feature is the amount of control over cursor speed available. For a slow cursor (to maintain fine drawing control), hit a lower digit key like 3 or 4. For high-speed drawing, hit 7 or 8. Cursor speed 9 is for maniacs only.
Laying down the spheres is simplicity itself. Just hit the B key. A disc appears at the cursor’s position, while the cursor itself moves to the right (so you can keep laying down more). Note that—when drawing, erasing, moving or placing balls—the cursor performs automatic wraparound should it go off the edge of the screen.
Even Bounce’s screen-clearing feature has been improved upon. In MFB, when you hit ESC, instead of the whole screen clearing, only the discs disappear. This lets you keep your old wall patterns. If you’d like to clear everything, just hit CTRL-ESC. To remove individual discs, draw or erase over them with the cursor.
To start things bouncing, hit START. (If you forgot to lay discs down, the program automatically returns you to the drawing mode.) Immediately, the playing field fills with red goop (to be eaten away by the bouncing balls), and the number of objects bouncing appears in the text window.
Again, as in drawing mode, you have a number of options. For starters, you have complete control over disc speed. Simply hit digit keys 0 through 9, 9 being the fastest. Keep in mind, however, that the fewer objects you have on screen, the faster they will go (this is a natural by-product of the limited processing speed of your Atari computer). One or two discs on the screen at speed 9 move so fast that they are more of a blur than an object.
You may notice as the balls are bouncing that only one of them is actually making bouncing sounds; the others are silent. To change the “sound focus,” hit the S key. This allows you to make different balls audible, one at a time. If you keep hitting S, you’ll finally return sound focus to the original disc. This effect is easier to see if you have only a few objects on the screen.
An improvement I’ve always wanted to add to Bounce is to give the user some direct control over the bouncing sphere. In MFB, this feature exists and is called “nudging.” When you hit the N key, the ball that the sound focus is on gets nudged. The effect of this is distinct, yet simple—it causes the ball to react as if a vertical wall were momentarily placed directly ahead of it. Essentially, the ball bounces off of a ghost wall.
Nudging is fun (as is holding down the N key for repeated nudgings) and, also, useful if there is a red area on the screen where no ball has been. You can direct one over to that area by nudging it. Note: it is best to practice nudging with only a few objects and at a slow speed. Also note: you can nudge different spheres by changing the sound focus.
When you want to change your wall configuration or the number of bouncing objects, hit SELECT to get back to the drawing mode. To start with a fresh screen, just hit CTRL-ESC.
;More Fun With BOUNCE
;by Joel Gluck
;for ANALOG COMPUTING
BYTE ARRAY xx(256),yy(256),
xd(256),yd(256)
BYTE xc,yc,hidden,cmode,TIME=20,
RANDOM=53770,CONSOL=53279,
CURSC=708,CH=764,NEWCOL=710,
dist=[0],audball=[0]
CARD num=[0],curspeed=[1500],
ballspeed=[900]
CARD ARRAY linept(48)
PROC gr5init()
CARD scrn=88
BYTE line,BALLCOL=709,WALLCOL=710
Graphics(5)
FOR line=0 TO 47 DO
linept(line)=scrn+20*line
OD
BALLCOL=$0C
WALLCOL=$94
RETURN
PROC plot5(BYTE x,y,col)
BYTE POINTER pixel
BYTE ARRAY colfil= [0 85 170 255],
mask= [63 207 243 252],
mask2= [192 48 12 3]
pixel = linept(y)+(x RSH 2)
pixel^ = pixel^ & mask(x & 3)
% (colfil(col)
& mask2(x & 3))
RETURN
BYTE FUNC locate5(BYTE x,y)
BYTE POINTER pixel
BYTE ARRAY mask= [192 48 12 3]
pixel = linept(y)+(x RSH 2)
RETURN((pixel^ & mask(x & 3)) RSH
(((x & 3) XOR 3) LSH 1))
PROC hline(BYTE y,c)
BYTE i
FOR i = 0 TO 79 DO
plot5(i,y,c)
OD
RETURN
PROC vline(BYTE x,c)
BYTE i
FOR i = 0 TO 47 DO
plot5(x,i,c)
OD
RETURN
PROC pauz(CARD p)
CARD i
FOR i=1 TO p DO
OD
RETURN
PROC f16(BYTE x,y)
BYTE g,a,b
g=Locate(x,y)
IF g=32 THEN
RETURN
FI
g==+128
NEWCOL=15
b=y
DO
color=0
Plot(x,b)
b==-1
color=g
Plot(x,b)
IF b=2 THEN
EXIT
FI
Sound(0,b,8,8)
pauz(700+x*50)
OD
a=x
DO
color=0
Plot(a,b)
a==+1
color=g
Plot(a,b)
IF a=19 THEN
EXIT
FI
Sound(0,a,8,8)
pauz(700+x*50)
OD
color=0
Plot(a,b)
SndRst()
RETURN
PROC colburst(BYTE x,y)
BYTE g,c,a
g=Locate(x,y)
IF g=32 THEN
RETURN
FI
g=g+128
NEWCOL=(Rand(16) LSH 4) % 10
color=g
a=x-1
IF a>13 THEN
a=0
FI
Plot(x,a)
DrawTo(x,y)
FOR c=0 TO 15 DO
Sound(0,0,4,15-c)
pauz(400)
OD
color=0
Plot(x,0)
DrawTo(x,y)
SndRst()
RETURN
PROC dropkick(BYTE x,y)
BYTE g,h,a,b
g=Locate(x,y)
IF g=32 THEN
RETURN
FI
g==+128
NEWCOL=152
b=y
DO
color=0
Plot(x,b)
b==+1
color=g
Plot(x,b)
IF b=23 THEN
EXIT
FI
Sound(0,b+10+(x LSH 1),10,8)
Sound(1,b+20+(x LSH 1),10,8)
pauz(400)
OD
SndRst()
h=0
NEWCOL=159
a=x
DO
color=h
Plot(a,b)
h=Locate(a+1,b-1)
a==+1
b==-1
color=g
Plot(a,b)
IF a=18 OR b=1 THEN
EXIT
FI
Sound(0,a-x,8,(b RSH 1))
pauz(800)
OD
color=0
Plot(a,b)
SndRst()
RETURN
PROC foo()
BYTE v
FOR v=0 TO 15 DO
Sound(0,255,10,15-v)
Sound(1,0,8,8-(v RSH 1))
pauz(500)
OD
SndRst()
RETURN
PROC intro()
BYTE x
Graphics(17)
CURSC=$08
Position(0,10)
PrintD(6,"MORE FUN WITH")
Position(0,12)
PrintD(6,"B O U N C E !")
Position(0,14)
PrintD(6,"BY JOEL GLUCK")
pauz(65000)
pauz(65000)
pauz(65000)
FOR x=0 TO 12 DO
f16(12-x,10)
OD
FOR x=0 TO 12 DO
colburst(x,12)
OD
FOR x=0 TO 12 DO
dropkick(12-x,14)
OD
CURSC=$48
Position(14,1)
PrintD(6,"ANALOG")
foo()
Position(11,3)
PrintD(6,"COMPUTING")
foo()
Position(12,5)
PrintD(6,"FEBRUARY")
foo()
Position(16,7)
PrintD(6,"1985")
foo()
pauz(65000)
pauz(65000)
pauz(65000)
RETURN
PROC drawdoc()
BYTE CURS=752
CURS=1
PutE()
Print("Use joystick and ")
PrintE("SPACE to draw/erase.")
Print("Hit B for balls, ")
PrintE("0-9 for brush speed.")
Print("ESC clrs balls; ")
PrintE("ctrl-ESC clrs screen.")
Print("Press START to Bounce!")
RETURN
PROC clearscrn()
BYTE a,b,g
FOR b=1 TO 19 DO
FOR a=1 TO 78 DO
g=locate5(a,b)
IF (g=2 OR CH>28) AND g>1 THEN
plot5(a,b,0)
Sound(0,b,6,4)
IF CH=28 THEN
pauz(300)
FI
FI
g=locate5(a,39-b)
IF (g=2 OR CH>28) AND g>1 THEN
plot5(a,39-b,0)
Sound(0,b,6,4)
IF CH=28 THEN
pauz(300)
FI
FI
OD
Sound(0,0,0,0)
OD
IF CH>28 OR hidden=2 THEN
hidden=0
FI
RETURN
PROC movecursor(BYTE bflag)
BYTE g,STIK=632,TRIG=644,vol
BYTE ARRAY v=[2 2 2 0 2 1 1 1 0 2 0
0 0 1 1 1 1 2 1 0 1 1]
INT cxd,cyd
IF STIK<15 OR bflag=1 THEN
cxd=v((STIK-5) LSH 1)-1
cyd=v(((STIK-5) LSH 1) % 1)-1
IF bflag=1 THEN
cxd=2
FI
g=hidden
IF TRIG THEN
vol=4
ELSE
vol=10
g=cmode*3
FI
Sound(0,(xc+yc)*cmode,
8+(cmode LSH 1),
vol-(cmode LSH 1))
plot5(xc,yc,g)
xc==+cxd
yc==+cyd
IF xc<1 THEN
xc=78
FI
IF xc>78 THEN
xc=1
FI
IF yc<1 THEN
yc=38
FI
IF yc>38 THEN
yc=1
FI
hidden=locate5(xc,yc)
plot5(xc,yc,1)
FI
RETURN
PROC audlayball()
BYTE i,j,k
FOR j=0 TO 2 DO
FOR i=j*50 TO j*50+20 DO
Sound(0,i,10,15-j*6)
pauz(100)
OD
OD
Sound(0,0,0,0)
RETURN
BYTE FUNC number()
BYTE n,v
v=CH
Open(2,"K:",4,1)
n=GetD(2)
Close(2)
CH=v
IF n>47 AND n<58 THEN
RETURN(57-n)
ELSE
RETURN(99)
FI
PROC audcmode()
BYTE n
FOR n=1 TO 5 DO
IF cmode THEN
Sound(0,100-n*10,10,4)
ELSE
Sound(1,150-n*10,10,4)
Sound(0,5-n,8,6)
FI
pauz(2000)
SndRst()
pauz(1000)
OD
RETURN
PROC cursor()
BYTE n
IF CH<>255 THEN
IF CH=33 THEN
cmode==XOR 1
audcmode()
ELSEIF CH=28 OR CH=156 THEN
clearscrn()
ELSEIF CH=21 THEN
hidden=2
plot5(xc,yc,2)
movecursor(1)
audlayball()
ELSE
n=number()
IF n<99 THEN
curspeed=n*500
FI
FI
CH=255
FI
movecursor(0)
RETURN
PROC bouncedoc()
CARD n
PutE()
n=num
IF n=1 THEN
PrintE("1 ball is bouncing.")
ELSE
PrintC(n)
PrintE(" balls are bouncing.")
FI
PrintE("Hit digits 0-9 for speed.")
Print("S changes sound focus, ")
PrintE("N nudges ball.")
Print("Press SELECT to Draw again.")
RETURN
PROC process(BYTE a,b)
BYTE g
g=locate5(a,b)
IF g=2 THEN
IF num<200 THEN
xx(num)=a
yy(num)=b
num==+1
ELSE
plot5(a,b,0)
FI
ELSEIF g=0 THEN
plot5(a,b,1)
FI
RETURN
PROC ballinit()
BYTE a,b
CURSC=$44
num=0
FOR b=1 TO 19 DO
FOR a=1 TO 78 DO
process(a,b)
process(a,39-b)
OD
OD
FOR a=0 TO num DO
xd(a)=Rand(2) LSH 1
yd(a)=Rand(2) LSH 1
OD
RETURN
PROC moveball(BYTE n)
BYTE g,pa,pb
g=locate5(xx(n)+xd(n)-1,yy(n)+yd(n)-1)
IF g<2 THEN
plot5(xx(n),yy(n),0)
xx(n)=xx(n)+xd(n)-1
yy(n)=yy(n)+yd(n)-1
plot5(xx(n),yy(n),2)
IF n=audball THEN
dist==+1
FI
RETURN
ELSE
pb=locate5(xx(n),yy(n)+yd(n)-1)
pa=locate5(xx(n)+xd(n)-1,yy(n))
IF n=audball THEN
IF dist THEN
Sound(0,170-((38-dist) LSH 2),
10,8)
Sound(1,((38-dist) LSH 2),
10,8)
FI
dist=0
TIME=0
FI
IF pa>1 THEN
xd(n)=2-xd(n)
IF pb>1 THEN
yd(n)=2-yd(n)
RETURN
ELSE
plot5(xx(n),yy(n),0)
yy(n)=yy(n)+yd(n)-1
plot5(xx(n),yy(n),2)
RETURN
FI
ELSEIF pb>1 THEN
yd(n)=2-yd(n)
plot5(xx(n),yy(n),0)
xx(n)=xx(n)+xd(n)-1
plot5(xx(n),yy(n),2)
RETURN
ELSEIF Rand(2) THEN
xd(n)=2-xd(n)
ELSE
yd(n)=2-yd(n)
RETURN
FI
FI
RETURN
PROC cleanup()
BYTE a,b
FOR b=1 TO 19 DO
FOR a=1 TO 78 DO
IF locate5(a,b)=1 THEN
plot5(a,b,0)
FI
IF locate5(a,39-b)=1 THEN
plot5(a,39-b,0)
FI
OD
OD
RETURN
PROC bounce()
CARD i
BYTE n
ballinit()
bouncedoc()
audball=0
dist=0
IF num THEN
DO
FOR i=0 TO num-1 DO
moveball(i)
IF CH<>255 THEN
IF CH=62 THEN
audball==+1
IF audball=num THEN
audball=0
FI
dist=0
ELSEIF CH=35 THEN
xd(audball)=2-xd(audball)
ELSE
n=number()
IF n<99 THEN
ballspeed=n*n*100
FI
FI
CH=255
FI
IF CONSOL=5 THEN
EXIT
FI
OD
pauz(ballspeed)
IF TIME THEN
SndRst()
FI
UNTIL CONSOL=5
OD
SndRst()
FI
cleanup()
RETURN
PROC MFWB()
intro()
gr5init()
hline(0,3)
hline(39,3)
vline(0,3)
vline(79,3)
DO
drawdoc()
xc=39
yc=19
hidden=locate5(xc,yc)
cmode=1
plot5(xc,yc,1)
DO
cursor()
CURSC=TIME
pauz(curspeed)
Sound(0,0,0,0)
pauz(curspeed)
UNTIL CONSOL=6
OD
plot5(xc,yc,hidden)
CH=255
bounce()
OD
RETURN