; AudioLastError Example
; ----------------------

; Effects must be initialized before the first WAV/Ogg playback
If Not InitAudioEffects() Then RuntimeError AudioLastError$()

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

; A looping machine hum to hear the effect on
sound=LoadSound("../../../samples/audio/media/machine.wav")
If sound=0 Then RuntimeError "The audio sample media is missing."
LoopSound sound
SoundVolume sound,0.25

; Meters make the audio state visible on screen
RequireAudio AudioMasterMeter(True)
RequireAudio AudioGroupMeter(0,True)

last_error$=""

channel=PlaySound(sound)
If channel=0 Then RuntimeError "Unable to play the example sound."

While Not KeyDown(1)

    ; Space provokes a recoverable failure: group 9 does not exist
    If KeyHit(57)
        ok=AudioGroupVolume(9,1)
        last_error=AudioLastError$()
    EndIf

    Cls
    Text 0,0,"Space: provoke a failure   Esc: exit"
    Text 0,20,"AudioLastError$() = ["+last_error+"]"
    Text 0,40,"Reading the error does not clear it; successful queries preserve it"
    Text 0,80,"Group 0 peak: "+AudioGroupPeak(0)+"   RMS: "+AudioGroupRMS(0)
    Text 0,100,"Master peak: "+AudioMasterPeak()+"   RMS: "+AudioMasterRMS()

    Flip

Wend

; Let shared effect tails fade before the program ends
For group=0 To 3
    RequireAudio AudioGroupClearEffects(group)
Next
StopChannel channel
FreeSound sound

End

; Stop with the recorded reason if an audio-effects call fails
Function RequireAudio(success)
    If Not success Then RuntimeError AudioLastError$()
End Function