Wwise SDK 2015.1.9

Use this function to tell the sound engine to switch to background/foreground/exit mode. Setting the RELEASING mode (for Home Menu) will fade out the volume and pause all sounds. Avoid calling other Wwise API while the application is in background. Setting the FOREGROUND mode (coming back from Home Menu) will resume sounds and fade in. Setting the EXIT mode must be done as soon as possible when the ProcUI status is PROCUI_STATUS_EXIT. Failing to do so can result in a deadlock if banks are unloaded before terminating the sound engine. However, you could also terminate the sound engine directly instead. Note that this function is not blocking; the fade will not be completed when the function returns. You can queue up other API calls if needed and then you must call RenderAudio soon after. If necessary, you should also Sleep() an appropriate amount of time to let the fade occur before releasing foreground. The amount of time to wait must include the minimum latency of the sound engine which is 64ms on the WiiU.

Parameters:

	in_eStatus	ProcUIStatus from ProcUIStatus() or ProcUIProcessMessages
	in_msFade	Fade out time. Set to 0 for minimum time.
	in_eCurve	Fade curve.
	in_pCallback	Callback to be called when fade out is finished. Leave NULL for no callback.
	in_pUserData	User data for the callback.