; RenderGPUTime Example
; ---------------------
; Requires Extended mode.

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

camera=CreateCamera()
PositionEntity camera,0,3,-14

light=CreateLight()
RotateEntity light,45,45,0

; An asteroid ring the player can switch off to lighten the GPU's work
hub=CreatePivot()
Dim rocks(29)
For n=0 To 29
    rocks(n)=CreateSphere(24)
    ScaleEntity rocks(n),0.6,0.6,0.6
    PositionEntity rocks(n),6*Cos(n*12),2*Sin(n*47),6*Sin(n*12)
    EntityParent rocks(n),hub
    EntityColor rocks(n),130,120,110
Next

heavy=True

While Not KeyDown(1)

    ; Space toggles the asteroid ring on and off
    If KeyHit(57) Then
        heavy=Not heavy
        For n=0 To 29
            If heavy Then ShowEntity rocks(n) Else HideEntity rocks(n)
        Next
    EndIf

    TurnEntity hub,0,0.5,0

    ; 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

    ; RenderGPUTime is non-blocking and returns -1 until a timestamp is ready
    gpu#=RenderGPUTime()
    Text 0,0,"Arrow keys: move camera   Space: toggle asteroids   Esc: exit"
    If gpu<0 Then Text 0,20,"RenderGPUTime() = -1 (no completed GPU timestamp yet)" Else Text 0,20,"RenderGPUTime() = "+gpu+" ms of GPU work"

    Flip

Wend

End