; Cls Example
; -----------

Graphics 640,480,0,2
SetBuffer BackBuffer()

clearing=1
angle#=0

While Not KeyDown(1)

    ; Space toggles whether we clear the screen each frame
    If KeyHit(57) Then clearing=1-clearing

    ; Cls wipes the drawing buffer clean; skip it and drawings pile up
    If clearing Then Cls

    ; A ball circling the screen centre
    angle=angle+2
    Color 128+Sin(angle)*127,200,128-Sin(angle)*100
    Oval 300+Cos(angle)*180,220+Sin(angle)*140,40,40,1

    ; Black panel keeps the overlay readable when trails build up
    Color 0,0,0
    Rect 0,0,640,44,1
    Color 255,255,255
    Text 0,0,"Space: toggle Cls on/off   Esc: exit"
    If clearing Then
        Text 0,20,"Cls ON - each frame starts clean"
    Else
        Text 0,20,"Cls OFF - old frames remain as trails"
    EndIf

    Flip

Wend

End