; CreateTimer Example
; -------------------

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

; CreateTimer(hertz) makes a timer that ticks at a fixed rate. Waiting
; on it with WaitTimer locks the main loop to that rate, so the game
; runs at the same speed on fast and slow computers.

hertz=60
timer=CreateTimer(hertz)

frames=0
fps=0
fps_time=MilliSecs()

While Not KeyDown(1)

    Cls

    ; 1/2/3 rebuild the timer at a new rate (freeing the old one)
    new_hertz=0
    If KeyHit(2) Then new_hertz=15
    If KeyHit(3) Then new_hertz=60
    If KeyHit(4) Then new_hertz=120
    If new_hertz>0 Then
        FreeTimer timer
        hertz=new_hertz
        timer=CreateTimer(hertz)
    EndIf

    ; One step per loop: the timer's rate IS the square's speed
    x=(x+4) Mod 640
    Rect x,220,40,40,True

    ; Count real frames per second to show the timer is in charge
    frames=frames+1
    If MilliSecs()-fps_time>=1000 Then
        fps=frames
        frames=0
        fps_time=MilliSecs()
    EndIf

    Text 0,0,"1: 15 Hz   2: 60 Hz   3: 120 Hz   Esc: exit"
    Text 0,20,"timer=CreateTimer("+hertz+")   measured "+fps+" fps"

    ; Flip False: don't also wait for the monitor - the timer sets the pace
    Flip False

    ; Wait here until the timer's next tick
    WaitTimer(timer)

Wend

End