/*
 * ----------------------------------------------------------------
 *
 *		ITA core libs
 *		(c) Copyright Institute of Technical Acoustics (ITA)
 *		RWTH Aachen University, Germany, 2015-2017
 *
 * ----------------------------------------------------------------
 *				    ____  __________  _______
 *				   //  / //__   ___/ //  _   |
 *				  //  /    //  /    //  /_|  |
 *				 //  /    //  /    //  ___   |
 *				//__/    //__/    //__/   |__|
 *
 * ----------------------------------------------------------------
 *
 */

#ifndef INCLUDE_WATCHER_DSMBC_TRIGGER
#define INCLUDE_WATCHER_DSMBC_TRIGGER

#include <ITAConvolutionDefinitions.h>

#include <ITAUncopyable.h>

// Lightweight atomic trigger for synchronized filter exchanges
class ITA_CONVOLUTION_API DSMBCTrigger : public ITAUncopyable
{
public:
	DSMBCTrigger() : m_iState(0) {};

	// Returns the current state
	int getState() const { return m_iState; };

	// Pull the trigger. Update/alter the state.
	void trigger() { ++m_iState; };
	
private:
	volatile int m_iState;
};

// Simple watcher class, realization update checks on a trigger
class ITA_CONVOLUTION_API DSMBCTriggerWatch
{
public:
	DSMBCTriggerWatch() : m_pTrigger(0), bFirst(true), m_iPrevTriggerState(0) {};

	const DSMBCTrigger* getWatchedTrigger() const { return m_pTrigger; };
	
	void setWatchedTrigger(const DSMBCTrigger* pNewTrigger) {
		m_pTrigger = pNewTrigger;
		bFirst = true;
	};

	// Logic: We always fire, if there is no trigger associated. This is needed in the convolver.
	bool fire() {
		if (!m_pTrigger) return true;

		int iNewTriggerState = m_pTrigger->getState();
		if ((iNewTriggerState != m_iPrevTriggerState) || bFirst) {
			m_iPrevTriggerState = iNewTriggerState;
			bFirst = false;
			return true;
		}

		return false;
	};

private:
	const DSMBCTrigger* m_pTrigger;
	bool bFirst;
	int m_iPrevTriggerState;
};

#endif // INCLUDE_WATCHER_DSMBC_TRIGGER