Randomly Placing Objects?

Hi all,

I have a game with all the main code inside a while loop. What I want to do is generate a set of random x and y coordinates for say, 5 rectangles, and then redraw those rectangles in the same position each time the screen is cleared and everything's updated. How do I do that without it recalculating the random values each time?

I tried using something like

If gen = 0 
[all the random code] 
gen = 1 
EndIf 

But that caused the program to freeze when I tried to run it (I'm using OS X Leopard 1.5.2, if that's important).

Any help anybody has would be appreciated.

Bookworm

' The TRect object remembers the x, y and size of each Rectangle created.
Type TRect
	Global list:TList=CreateList()
	Field x:Int
	Field y:Int
	Field size:Int
	' Create a new rectangle at the position and size specified.
	Function Create(x:Int,y:Int,size:Int=50)
		Local temp:trect = New trect
		temp.x=x
		temp.y=y
		temp.size=size
		ListAddLast list,temp
	End Function
	' draw all the rectangles using their saved position.
	Function draw()
		For Local all:trect = EachIn list
			DrawRect all.x,all.y,all.size,all.size
		Next
	End Function	
End Type
Local gw:Int=800
Local gh:Int=600
Graphics gw,gh
SeedRnd MilliSecs()
' Create our rectangles with random X, Y positions.
For Local x:Int=0 To 4
	Local xpos:Int=Rand(0,gw)
	Local ypos:Int=Rand(0,gh)
	trect.Create(xpos,ypos)
Next
While Not KeyHit(KEY_ESCAPE)
	Cls
	' Draw all our rectangles,
	trect.draw()
	Flip
Wend	

Put some random values into an array at the start, outside the loop, and then just call the array instead of Rand().

ie

Local X:Float[10]
Local Y:Float[10]
For Local Obj:Int=0 to 9
   X:Obj=Rand(0,ScreenWidth-1)
   Y:Obj=Rand(0,ScreenHeight-1)
Next
While GameRunning=True
   For Local Count:Int=0 to 9
      Plot X[Count],Y[Count]
   Next
Wend

I will try both of those, thanks for your help - I should be able to tell you if it works by later today.

Wellp, here's my code:

Graphics 800,600,0

'first, set the variables to make things nice and tidy
Global x = 30, y = 30, bugGen = True, killed:Int = 0


bugCounter = 0

Function execMainGame(kill:Int)

'create bugs 
Type CBugs
	Global list:TList=CreateList()
	Global saved:TList=CreateList() 
	Field cx:Int
	Field cy:Int
	Field size:Int
	' Create a new bug at the position and size specified.

	Function Create(ccx:Int,ccy:Int,size:Int=30)
		Local temp:Cbugs = New CBugs
		temp.cx=ccx
		temp.cy=ccy
		temp.size=size
		ListAddLast list,temp
	End Function

	Function draw()
		For Local all:Cbugs = EachIn list
			DrawRect all.cx,all.cy,all.size,all.size
		Next
	End Function 
End Type
Local gw:Int=800
Local gh:Int=600
Graphics gw,gh
SeedRnd MilliSecs()
' Create our rectangles with random X, Y positions.

For Local bugCounter:Int=0 To 5
	Local xpos:Int=Rand(0,gw)
	Local ypos:Int=Rand(0,gh)
	Cbugs.Create(xpos,ypos)
Next

While Not KeyHit(KEY_ESCAPE) And killed = 0 
	#main 
	'show us the info 
	SetColor 0,0,255
	DrawText "Use the arrow keys (up, down, left, right) to move the Pac-A-Dot", 0, 0
	DrawText "Use the spacebar to reset the Pac-A-Dot to the top right corner of the screen; hit ESC to quit.", 0, 10
	
	SetColor 255,255,255
	
	'make the divider bar 
	DrawRect 1,25,800,10   
	
	'make our little pac-a-dot - he's green!
	SetColor 0,255,0
	DrawOval x, y, 30, 30 
	
	'make the first set of bugs - red
	SetColor 255,0,0
	Cbugs.draw() 
	
	If Cbugs.draw = True 
	kill = 1
	EndIf 
	
	'move him around
	x = MouseX ()
	y = MouseY () 
	DrawOval x,y,30,30 
	
	'kill key for suicide
	If KeyDown(KEY_ESC) 
	kill = 1
	EndIf 
	
	'make sure he doesn't hit that text
	If y<= 30
	y = 31
	EndIf 
	
	Flip;Cls 

Wend

If kill = 1 Return 1
If kill = 0 Return 0  

End Function 

Cls 

'starting or finishing?
If(killed = 0) 
execMainGame(killed) 
EndIf 

'so, you died - too bad, but you can start again 
If(killed = 1) 
DrawText "You were killed! Sorry. Press any key to exit.",300,100
Flip 

WaitKey

EndIf 

End  

I'm getting an error which says "Types 'Int()' and 'Int' are unrelated" when I try to compile... any ideas?

	If Cbugs.draw = True 

should be

	If Cbugs.draw() = True 

I have a noob question about this OOP example that illustrates a gap in my understanding on the topic that's been grating at me. :)

Why the choice of a function for both create and draw? Why not a method for draw? Pros and cons? I've done it both ways and it works fine for me. But I'm not sure which is more proper and why.

TIA

-pmc