Control balls with mouse pointer as gravity source.

Control balls with mouse pointer as gravity source.
Thanks to NewGuy for his very helpful piece of code in "Strong Gravity."

                                    ` This code was downloaded from The Game Creators
                                    ` It is reproduced here with full permission
                                    ` http://www.thegamecreators.com
                                    
                                    rem ===INITIALISATION=====================================
ScreenWidth=1024
ScreenHeight=768
ScreenDepth=32
RefreshRate=60

BorderOn=1
NumBalls=5
BallSize=10
BallsSpeed#=0.5
Gravity#=200 `Gravity# = (GravConst#*Mass1#*Mass2#)/Dist#^2


sync on
sync rate RefreshRate
`hide mouse
set display mode ScreenWidth,ScreenHeight,ScreenDepth

rem Random Ball Starting Positions
DIM xPosMem#(NumBalls)
for xPos=1 to NumBalls
xPosMem#(xPos)=rnd(ScreenWidth-(2*BallSize))+BallSize
next xPos

DIM yPosMem#(NumBalls)
for yPos=1 to NumBalls
yPosMem#(yPos)=rnd(ScreenHeight-(2*BallSize))+BallSize
next yPos

rem Random Ball Starting Velocities
DIM xVelMem#(NumBalls)
for xVel=1 to NumBalls
xVelMem#(xVel)=rnd(1000)
next xVel

DIM yVelMem#(NumBalls)
for yVel=1 to NumBalls
yVelMem#(yVel)=rnd(1000)
next yVel

rem Creates Random Pos/Neg Values
DIM RevMix#(NumBalls)
for Mixer=1 to NumBalls
PN=rnd(1) : if PN= 1 then RevMix#(Mixer)=1 else RevMix#(Mixer)=-1
next Mixer


do
rem ===BALLS======================================
FOR Loopy1=1 TO NumBalls
rem Update Ball Positions
xPosMem#(Loopy1)=xPosMem#(Loopy1)+(((xVelMem#(Loopy1))/(1000/BallsSpeed#))*RevMix#(Loopy1))
yPosMem#(Loopy1)=yPosMem#(Loopy1)+(((yVelMem#(Loopy1))/(1000/BallsSpeed#))*RevMix#(Loopy1))

rem Draw Balls
ink RGB(255,255,255),0
circle xPosMem#(Loopy1),yPosMem#(Loopy1),BallSize

rem Collisions with Screen
if xPosMem#(Loopy1)>(ScreenWidth-(BallSize)) or xPosMem#(Loopy1)<(BallSize) then (xVelMem#(Loopy1))=-(xVelMem#(Loopy1))
if yPosMem#(Loopy1)>(ScreenHeight-(BallSize)) or yPosMem#(Loopy1)<(Ballsize) then (yVelMem#(Loopy1))=-(yVelMem#(Loopy1))
NEXT Loopy1

rem ===LINE BORDER====================================
if BorderOn=1
ink RGB(255,255,255),0
line 0,0,Screenwidth,0
line 0,0,0,ScreenHeight
line ScreenWidth-1,0,ScreenWidth-1,ScreenHeight-1
line 0,ScreenHeight-1,Screenwidth-1,ScreenHeight-1
endif

rem ===GRAVITY==============================================
FOR Loopy2=1 TO NumBalls
if mouseclick()=2 then GravOn=1 else GravOn=0

Dist#= sqrt( (mousex()-xPosMem#(Loopy2))^2 + (mousey()-yPosMem#(Loopy2))^2 )

X# = newXvalue(0,atanfull(xPosMem#(Loopy2)-mousex(),yPosMem#(Loopy2)-mousey())+180,Gravity#)
Y# = newZvalue(0,atanfull(xPosMem#(Loopy2)-mousex(),yPosMem#(Loopy2)-mousey())+180,Gravity#)

if GravOn=1 then (xVelMem#(Loopy2))=(xVelMem#(Loopy2))+(X#)*RevMix#(Loopy2)
if GravOn=1 then (yVelMem#(Loopy2))=(yVelMem#(Loopy2))+(Y#)*RevMix#(Loopy2)

`if xVelMem#(Loopy2)> 2 then xVelMem#(Loopy2)=2
`if yVelMem#(Loopy2)> 2 then yVelMem#(Loopy2)=2

NEXT Loopy2

sync
cls
loop