tetrees/Plugins/Wwise/ThirdParty/include/AK/Plugin/PluginServices/AkFXDurationHandler.h

/*******************************************************************************
The content of this file includes portions of the AUDIOKINETIC Wwise Technology
released in source code form as part of the SDK installer package.

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Licensees holding valid commercial licenses to the AUDIOKINETIC Wwise Technology
may use this file in accordance with the end user license agreement provided 
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"Apache License"); you may not use this file except in compliance with the 
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under the Apache License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES
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the specific language governing permissions and limitations under the License.

  Copyright (c) 2023 Audiokinetic Inc.
*******************************************************************************/
 
#ifndef _AKFXDURATIONHANDLER_H_
#define _AKFXDURATIONHANDLER_H_

#include <AK/SoundEngine/Common/AkTypes.h>

/// Duration handler service for source plug-in.
/// Duration may change between different execution
class AkFXDurationHandler
{
public:

	/// Setup duration handler
	inline void Setup(	
		AkReal32 in_fDuration,		///< Duration (in secs)
		AkInt16 in_iLoopingCount,	///< Number of loop iterations (0 == infinite)
		AkUInt32 in_uSampleRate 	///< Sample rate
		)
	{
		m_uSampleRate = in_uSampleRate;
		SetDuration( in_fDuration );
		SetLooping( in_iLoopingCount );
		Reset();
	}

	/// Reset looping and frame counters and start again.
	inline void Reset()
	{
		m_uFrameCount = 0;
	}

	/// Change number of loop iterations (0 == infinite).
	inline void SetLooping( AkInt16 in_iNumLoops )
	{
		m_iNumLoops = in_iNumLoops;
	}

	/// Set current duration per iteration (in secs).
	inline void SetDuration( AkReal32 in_fDuration )
	{
		m_uIterationFrame = (AkUInt32) (in_fDuration*m_uSampleRate);
		m_uIterationFrame = (m_uIterationFrame + 3) & ~3; // Align to next 4 frame boundary for SIMD alignment
	}

	/// Return current total duration (considering looping) in secs.
	inline AkReal32 GetDuration() const
	{
		// Note: Infinite looping will return a duration of 0 secs.
		return (AkReal32)(m_uIterationFrame*m_iNumLoops)/m_uSampleRate;
	}

	/// Set current number of frames to be produced (validFrames) 
	/// and output state of audio buffer and advance internal state.
	inline void ProduceBuffer( AkAudioBuffer * io_pBuffer )
	{
		io_pBuffer->eState = ProduceBuffer( io_pBuffer->MaxFrames(), io_pBuffer->uValidFrames );
	}

	/// Set current number of frames to be produced (validFrames) 
	/// and output state of audio buffer and advance internal state.
	inline AKRESULT ProduceBuffer( AkUInt16 in_uMaxFrames, AkUInt16 & out_uValidFrames )
	{
		// Infinite looping or not reached the end, always producing full capacity
		out_uValidFrames = in_uMaxFrames;
		AKRESULT eState = AK_DataReady;

		if ( m_iNumLoops != 0 )
		{
			// Finite looping, produce full buffer untill the end.
			const AkUInt32 uTotalFrames = m_iNumLoops*m_uIterationFrame;
			if ( m_uFrameCount < uTotalFrames )
			{
				const AkUInt32 uFramesRemaining = uTotalFrames-m_uFrameCount;
				if ( uFramesRemaining <= in_uMaxFrames )
				{
					out_uValidFrames = (AkUInt16)uFramesRemaining;
					eState = AK_NoMoreData;
				}
			}
			else
			{
				out_uValidFrames = 0;
				eState = AK_NoMoreData;
			}
		}	
		m_uFrameCount += out_uValidFrames;

		return eState;
	}

protected:

	AkUInt32	m_uIterationFrame;	// Number of frames in a single loop iteration 
	AkUInt32	m_uFrameCount;		// Number of frames output in the current iteration
	AkUInt32	m_uSampleRate;		// Sample rate used to convert time to samples
	AkInt16		m_iNumLoops;		// Number of loop iterations (0 == infinite looping)
	
};

#endif // _AKFXDURATIONHANDLER_H_