; CountLines Example
; ------------------
; Requires Extended mode.

Graphics3D 640,480,0,2
SetBuffer BackBuffer()

SeedRnd MilliSecs()

camera=CreateCamera()
PositionEntity camera,0,1,-9

; A starfield sketch that grows one random line per frame
scribble=CreateLineList()
EntityColor scribble,160,120,255
LineWidth scribble,2

While Not KeyDown(1)

    ; Space adds a burst of ten extra segments
    If KeyHit(57) Then
        For n=1 To 10
            AddLine scribble,Rnd(-3,3),Rnd(-2,2),0,Rnd(-3,3),Rnd(-2,2),0
        Next
    EndIf

    ; One new segment every frame keeps the sketch growing
    AddLine scribble,Rnd(-3,3),Rnd(-2,2),0,Rnd(-3,3),Rnd(-2,2),0

    ; CountLines drives the game logic: wipe the sketch once it reaches 200 segments
    If CountLines(scribble)>=200 Then ClearLines scribble

    ; Arrow keys move the camera
    If KeyDown(200) Then MoveEntity camera,0,0,0.1
    If KeyDown(208) Then MoveEntity camera,0,0,-0.1
    If KeyDown(203) Then TurnEntity camera,0,1,0
    If KeyDown(205) Then TurnEntity camera,0,-1,0

    RenderWorld

    Text 0,0,"Arrow keys: move camera   Space: add 10 segments   Esc: exit"
    Text 0,20,"CountLines(scribble) = "+CountLines(scribble)+"   (auto-clears at 200)"

    Flip

Wend

End