Graphics 320,240,32,2
SetBuffer BackBuffer()

Global bank = CreateBank(320*240*4)

While Not KeyDown(1)
 BankCircle(MouseX(),MouseY(),7,$FF0000)
 w = (w + 5) Mod 360
 For i = 1 To 360 Step 60
  BankCircle(MouseX()+Cos(i+w)*12,MouseY()+Sin(i+w)*12,5,$FF0000)
 Next
 If r > 240 Then rp = -1
 If r < 15 Then rp = 1
 If g > 240 Then gp = -1
 If g < 15 Then gp = 1
 If b > 240 Then bp = -1
 If b < 15 Then bp = 1
 r = r + Rand(2) * rp
 g = g + Rand(4) * gp
 b = b + Rand(6) * bp
 BlurBank(r,g,b,0.95)
 Update
Wend
End

Function BlurBank(r,g,b,factor#=0.85,dirx=0,diry=0)
 For x = 319 To 0 Step -1
  For y = -1 To 237
   rgb = Get(x,y)
   rb# = (rgb And $FF0000) / $10000 * factor + r * (1 - factor)
   gb# = (rgb And $FF00) / $100 * factor + g * (1 - factor)
   bb# = (rgb And $FF) * factor + b * (1 - factor)
   PokeInt(bank,(x+1)*4+(y+1)*320*4,Int(rb) * $10000 + Int(gb) * $100 + Int(bb))
  Next
 Next
End Function

Function ClsBank(col=0)
 For x = 0 To 319
  For y = 0 To 239
   PokeInt(bank,x*4+y*320*4,col)
  Next
 Next
End Function

Function BankCircle(x,y,size,col)
 For w = 0 To 359
  tx = x + Cos(w) * size
  ty = y + Sin(w) * size
  If (tx < 320) And (ty < 240) And (tx >= 0) And (ty >= 0) Then PokeInt(bank,tx*4+ty*320*4,col)
 Next
End Function

Function Update()
 LockBuffer()
 For x = 0 To 319
  For y = 0 To 239
   WritePixelFast(x,y,PeekInt(bank,x*4+y*320*4))
  Next
 Next
 UnlockBuffer()
 Flip False
End Function

Function Set(x,y,value) ; <-- sehr langsam
 If (x < 320) And (y < 240) And (x >= 0) And (y >= 0) Then PokeInt(bank,x*4+y*320*4,value)
End Function

Function Get(x,y) ; <-- sehr langsam
 If (x < 320) And (y < 240) And (x >= 0) And (y >= 0) Then
  Return PeekInt(bank,x*4+y*320*4)
 Else
  Return 0
 EndIf
End Function