/*----------------------------------------------------------------------------
 *
 * File: 
 * eas_reverb.c 
 *
 * Contents and purpose:
 * Contains the implementation of the Reverb effect.
 *
 *
 * Copyright Sonic Network Inc. 2006

 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 *----------------------------------------------------------------------------
 * Revision Control:
 *   $Revision: 510 $
 *   $Date: 2006-12-19 01:47:33 -0800 (Tue, 19 Dec 2006) $
 *----------------------------------------------------------------------------
*/

/*------------------------------------
 * includes
 *------------------------------------
*/

#include "eas_data.h"
#include "eas_effects.h"
#include "eas_math.h"
#include "eas_reverbdata.h"
#include "eas_reverb.h"
#include "eas_config.h"
#include "eas_host.h"
#include "eas_report.h"

/* prototypes for effects interface */
static EAS_RESULT ReverbInit (EAS_DATA_HANDLE pEASData, EAS_VOID_PTR *pInstData);
static void ReverbProcess (EAS_VOID_PTR pInstData, EAS_PCM *pSrc, EAS_PCM *pDst, EAS_I32 numSamples);
static EAS_RESULT ReverbShutdown (EAS_DATA_HANDLE pEASData, EAS_VOID_PTR pInstData);
static EAS_RESULT ReverbGetParam (EAS_VOID_PTR pInstData, EAS_I32 param, EAS_I32 *pValue);
static EAS_RESULT ReverbSetParam (EAS_VOID_PTR pInstData, EAS_I32 param, EAS_I32 value);

/* common effects interface for configuration module */
const S_EFFECTS_INTERFACE EAS_Reverb = 
{
	ReverbInit,
	ReverbProcess,
	ReverbShutdown,
	ReverbGetParam,
	ReverbSetParam
};



/*----------------------------------------------------------------------------
 * InitializeReverb()
 *----------------------------------------------------------------------------
 * Purpose: 
 * 
 * Inputs: 
 *			
 * Outputs:
 *
 *----------------------------------------------------------------------------
*/
static EAS_RESULT ReverbInit(EAS_DATA_HANDLE pEASData, EAS_VOID_PTR *pInstData)
{
	EAS_I32 i;
	EAS_U16	nOffset;
	EAS_INT temp;

	S_REVERB_OBJECT *pReverbData;
	S_REVERB_PRESET *pPreset;

	/* check Configuration Module for data allocation */
	if (pEASData->staticMemoryModel)
		pReverbData = EAS_CMEnumFXData(EAS_MODULE_REVERB);

	/* allocate dynamic memory */
	else
		pReverbData = EAS_HWMalloc(pEASData->hwInstData, sizeof(S_REVERB_OBJECT));

	if (pReverbData == NULL)
	{
		{ /* dpp: EAS_ReportEx(_EAS_SEVERITY_FATAL, "Failed to allocate Reverb memory\n"); */ }
		return EAS_ERROR_MALLOC_FAILED;
	}

	/* clear the structure */
	EAS_HWMemSet(pReverbData, 0, sizeof(S_REVERB_OBJECT));

	ReverbReadInPresets(pReverbData);

	pReverbData->m_nMinSamplesToAdd = REVERB_UPDATE_PERIOD_IN_SAMPLES;
                   
    pReverbData->m_nRevOutFbkR = 0;
    pReverbData->m_nRevOutFbkL = 0;
    
    pReverbData->m_sAp0.m_zApIn  = AP0_IN;
    pReverbData->m_sAp0.m_zApOut = AP0_IN + DEFAULT_AP0_LENGTH;
    pReverbData->m_sAp0.m_nApGain = DEFAULT_AP0_GAIN;

    pReverbData->m_zD0In = DELAY0_IN;

    pReverbData->m_sAp1.m_zApIn  = AP1_IN;
    pReverbData->m_sAp1.m_zApOut = AP1_IN + DEFAULT_AP1_LENGTH;
    pReverbData->m_sAp1.m_nApGain = DEFAULT_AP1_GAIN;

    pReverbData->m_zD1In = DELAY1_IN;

	pReverbData->m_zLpf0	= 0;
	pReverbData->m_zLpf1	= 0;
	pReverbData->m_nLpfFwd	= 8837;
	pReverbData->m_nLpfFbk	= 6494;

	pReverbData->m_nSin		= 0;
	pReverbData->m_nCos		= 0;
	pReverbData->m_nSinIncrement	= 0;
	pReverbData->m_nCosIncrement	= 0;

	// set xfade parameters
	pReverbData->m_nXfadeInterval = (EAS_U16)REVERB_XFADE_PERIOD_IN_SAMPLES;
	pReverbData->m_nXfadeCounter = pReverbData->m_nXfadeInterval + 1;	// force update on first iteration
	pReverbData->m_nPhase = -32768;
	pReverbData->m_nPhaseIncrement = REVERB_XFADE_PHASE_INCREMENT;

	pReverbData->m_nNoise = (EAS_I16)0xABCD;

	pReverbData->m_nMaxExcursion = 0x007F;

	// set delay tap lengths
	nOffset = ReverbCalculateNoise( pReverbData->m_nMaxExcursion,
									&pReverbData->m_nNoise );

	pReverbData->m_zD1Cross = 
		DELAY1_OUT - pReverbData->m_nMaxExcursion + nOffset;

	nOffset = ReverbCalculateNoise( pReverbData->m_nMaxExcursion,
									&pReverbData->m_nNoise );

	pReverbData->m_zD0Cross = 
		DELAY1_OUT - pReverbData->m_nMaxExcursion - nOffset;

	nOffset = ReverbCalculateNoise( pReverbData->m_nMaxExcursion,
									&pReverbData->m_nNoise );

	pReverbData->m_zD0Self	= 
		DELAY0_OUT - pReverbData->m_nMaxExcursion - nOffset;

	nOffset = ReverbCalculateNoise( pReverbData->m_nMaxExcursion,
									&pReverbData->m_nNoise );

	pReverbData->m_zD1Self	= 
		DELAY1_OUT - pReverbData->m_nMaxExcursion + nOffset;

	// for debugging purposes, allow noise generator
	pReverbData->m_bUseNoise = EAS_FALSE;

	// for debugging purposes, allow bypass
	pReverbData->m_bBypass = EAS_TRUE;	//EAS_FALSE;

	pReverbData->m_nNextRoom = 1;

	pReverbData->m_nCurrentRoom = pReverbData->m_nNextRoom + 1;	// force update on first iteration

	pReverbData->m_nWet	= REVERB_DEFAULT_WET;

	pReverbData->m_nDry	= REVERB_DEFAULT_DRY;

	// set base index into circular buffer
	pReverbData->m_nBaseIndex = 0;

	// set the early reflections, L
	pReverbData->m_sEarlyL.m_nLpfFbk = 4915;
	pReverbData->m_sEarlyL.m_nLpfFwd = 27852;
	pReverbData->m_sEarlyL.m_zLpf = 0;
	
	for (i=0; i < REVERB_MAX_NUM_REFLECTIONS; i++)
	{
		pReverbData->m_sEarlyL.m_nGain[i] = 0;
		pReverbData->m_sEarlyL.m_zDelay[i] = 0;
	}

	// set the early reflections, R
	pReverbData->m_sEarlyR.m_nLpfFbk = 4915;
	pReverbData->m_sEarlyR.m_nLpfFwd = 27852;
	pReverbData->m_sEarlyR.m_zLpf = 0;
	
	for (i=0; i < REVERB_MAX_NUM_REFLECTIONS; i++)
	{
		pReverbData->m_sEarlyR.m_nGain[i] = 0;
		pReverbData->m_sEarlyR.m_zDelay[i] = 0;
	}

	// clear the reverb delay line
	for (i=0; i < REVERB_BUFFER_SIZE_IN_SAMPLES; i++)
	{
		pReverbData->m_nDelayLine[i] = 0;
	}

	////////////////////////////////
	///code from the EAS DEMO Reverb
	//now copy from the new preset into the reverb
	pPreset = &pReverbData->m_sPreset.m_sPreset[pReverbData->m_nNextRoom];

	pReverbData->m_nLpfFbk = pPreset->m_nLpfFbk;
	pReverbData->m_nLpfFwd = pPreset->m_nLpfFwd;

	pReverbData->m_nEarly = pPreset->m_nEarly;
	pReverbData->m_nWet = pPreset->m_nWet;
	pReverbData->m_nDry = pPreset->m_nDry;

	pReverbData->m_nMaxExcursion = pPreset->m_nMaxExcursion;
	//stored as time based, convert to sample based
	temp = pPreset->m_nXfadeInterval;
	/*lint -e{702} shift for performance */
	temp = (temp * _OUTPUT_SAMPLE_RATE) >> 16;
	pReverbData->m_nXfadeInterval = (EAS_U16) temp;
	//gsReverbObject.m_nXfadeInterval = pPreset->m_nXfadeInterval;

	pReverbData->m_sAp0.m_nApGain = pPreset->m_nAp0_ApGain;
	//stored as time based, convert to absolute sample value
	temp = pPreset->m_nAp0_ApOut;
	/*lint -e{702} shift for performance */
	temp = (temp * _OUTPUT_SAMPLE_RATE) >> 16;
	pReverbData->m_sAp0.m_zApOut = (EAS_U16) (pReverbData->m_sAp0.m_zApIn + temp);
	//gsReverbObject.m_sAp0.m_zApOut = pPreset->m_nAp0_ApOut;

	pReverbData->m_sAp1.m_nApGain = pPreset->m_nAp1_ApGain;
	//stored as time based, convert to absolute sample value
	temp = pPreset->m_nAp1_ApOut;
	/*lint -e{702} shift for performance */
	temp = (temp * _OUTPUT_SAMPLE_RATE) >> 16;
	pReverbData->m_sAp1.m_zApOut = (EAS_U16) (pReverbData->m_sAp1.m_zApIn + temp);
	//gsReverbObject.m_sAp1.m_zApOut = pPreset->m_nAp1_ApOut;
	///code from the EAS DEMO Reverb
	////////////////////////////////

	*pInstData = pReverbData;

	return EAS_SUCCESS;

}	/* end InitializeReverb */



/*----------------------------------------------------------------------------
 * ReverbProcess()
 *----------------------------------------------------------------------------
 * Purpose: 
 * Reverberate the requested number of samples (block based processing)
 *
 * Inputs: 
 * pInputBuffer - src buffer
 * pOutputBuffer - dst buffer
 * nNumSamplesToAdd - number of samples to write to buffer
 *
 * Outputs:
 * number of samples actually written to buffer
 * 
 * Side Effects:
 * - samples are added to the presently free buffer
 *
 *----------------------------------------------------------------------------
*/
static void ReverbProcess(EAS_VOID_PTR pInstData, EAS_PCM *pSrc, EAS_PCM *pDst, EAS_I32 numSamples)
{
	S_REVERB_OBJECT *pReverbData;

	pReverbData = (S_REVERB_OBJECT*) pInstData;

	//if bypassed or the preset forces the signal to be completely dry
	if (pReverbData->m_bBypass || 
		(pReverbData->m_nWet == 0 && pReverbData->m_nDry == 32767))
	{
		if (pSrc != pDst)
			EAS_HWMemCpy(pSrc, pDst, numSamples * NUM_OUTPUT_CHANNELS * (EAS_I32) sizeof(EAS_PCM));
		return;
	}

	if (pReverbData->m_nNextRoom != pReverbData->m_nCurrentRoom)
	{
		ReverbUpdateRoom(pReverbData);
	}

	ReverbUpdateXfade(pReverbData, numSamples);

	Reverb(pReverbData, numSamples, pDst, pSrc);

	/* check if update counter needs to be reset */
	if (pReverbData->m_nUpdateCounter >= REVERB_MODULO_UPDATE_PERIOD_IN_SAMPLES)
	{
		/* update interval has elapsed, so reset counter */
		pReverbData->m_nUpdateCounter = 0;
	}	/* end if m_nUpdateCounter >= update interval */

	/* increment update counter */ 
	pReverbData->m_nUpdateCounter += (EAS_I16)numSamples;

}	/* end ComputeReverb */

/*----------------------------------------------------------------------------
 * ReverbUpdateXfade
 *----------------------------------------------------------------------------
 * Purpose: 
 * Update the xfade parameters as required
 *
 * Inputs: 
 * nNumSamplesToAdd - number of samples to write to buffer
 *
 * Outputs:
 * 
 * 
 * Side Effects:
 * - xfade parameters will be changed
 *
 *----------------------------------------------------------------------------
*/
static EAS_RESULT ReverbUpdateXfade(S_REVERB_OBJECT *pReverbData, EAS_INT nNumSamplesToAdd)
{
	EAS_U16	nOffset;
	EAS_I16 tempCos;
	EAS_I16 tempSin;

	if (pReverbData->m_nXfadeCounter >= pReverbData->m_nXfadeInterval)
	{
		/* update interval has elapsed, so reset counter */
		pReverbData->m_nXfadeCounter = 0;

		// Pin the sin,cos values to min / max values to ensure that the
		// modulated taps' coefs are zero (thus no clicks)
		if (pReverbData->m_nPhaseIncrement > 0)
		{
			// if phase increment > 0, then sin -> 1, cos -> 0
			pReverbData->m_nSin = 32767;
			pReverbData->m_nCos = 0;

			// reset the phase to match the sin, cos values
			pReverbData->m_nPhase = 32767;

			// modulate the cross taps because their tap coefs are zero
			nOffset = ReverbCalculateNoise( pReverbData->m_nMaxExcursion, &pReverbData->m_nNoise );

			pReverbData->m_zD1Cross = 
				DELAY1_OUT - pReverbData->m_nMaxExcursion + nOffset;

			nOffset = ReverbCalculateNoise( pReverbData->m_nMaxExcursion, &pReverbData->m_nNoise );

			pReverbData->m_zD0Cross = 
				DELAY0_OUT - pReverbData->m_nMaxExcursion - nOffset;
		}
		else
		{
			// if phase increment < 0, then sin -> 0, cos -> 1
			pReverbData->m_nSin = 0;
			pReverbData->m_nCos = 32767;

			// reset the phase to match the sin, cos values
			pReverbData->m_nPhase = -32768;

			// modulate the self taps because their tap coefs are zero
			nOffset = ReverbCalculateNoise( pReverbData->m_nMaxExcursion, &pReverbData->m_nNoise );

			pReverbData->m_zD0Self	= 
				DELAY0_OUT - pReverbData->m_nMaxExcursion - nOffset;

			nOffset = ReverbCalculateNoise( pReverbData->m_nMaxExcursion, &pReverbData->m_nNoise );

		    pReverbData->m_zD1Self	= 
				DELAY1_OUT - pReverbData->m_nMaxExcursion + nOffset;

		}	// end if-else (pReverbData->m_nPhaseIncrement > 0)

		// Reverse the direction of the sin,cos so that the
		// tap whose coef was previously increasing now decreases
		// and vice versa
		pReverbData->m_nPhaseIncrement = -pReverbData->m_nPhaseIncrement;

	}	// end if counter >= update interval 

	//compute what phase will be next time
	pReverbData->m_nPhase += pReverbData->m_nPhaseIncrement;

	//calculate what the new sin and cos need to reach by the next update
	ReverbCalculateSinCos(pReverbData->m_nPhase, &tempSin, &tempCos);

	//calculate the per-sample increment required to get there by the next update
	/*lint -e{702} shift for performance */
	pReverbData->m_nSinIncrement = 
			(tempSin - pReverbData->m_nSin) >> REVERB_UPDATE_PERIOD_IN_BITS;
	
	/*lint -e{702} shift for performance */
	pReverbData->m_nCosIncrement = 
			(tempCos - pReverbData->m_nCos) >> REVERB_UPDATE_PERIOD_IN_BITS;
	

	/* increment update counter */ 
	pReverbData->m_nXfadeCounter += (EAS_U16) nNumSamplesToAdd;

	return EAS_SUCCESS;
	
}	/* end ReverbUpdateXfade */


/*----------------------------------------------------------------------------
 * ReverbCalculateNoise
 *----------------------------------------------------------------------------
 * Purpose: 
 * Calculate a noise sample and limit its value
 *
 * Inputs: 
 * nMaxExcursion - noise value is limited to this value
 * pnNoise - return new noise sample in this (not limited)
 *
 * Outputs:
 * new limited noise value
 * 
 * Side Effects:
 * - *pnNoise noise value is updated
 *
 *----------------------------------------------------------------------------
*/
static EAS_U16 ReverbCalculateNoise(EAS_U16 nMaxExcursion, EAS_I16 *pnNoise)
{
	// calculate new noise value
	*pnNoise = (EAS_I16) (*pnNoise * 5 + 1);

#if 0	// 1xxx, test
	*pnNoise = 0;
#endif 	// 1xxx, test

	// return the limited noise value
	return (nMaxExcursion & (*pnNoise));

}	/* end ReverbCalculateNoise */

/*----------------------------------------------------------------------------
 * ReverbCalculateSinCos
 *----------------------------------------------------------------------------
 * Purpose: 
 * Calculate a new sin and cosine value based on the given phase
 *
 * Inputs: 
 * nPhase	- phase angle
 * pnSin	- input old value, output new value
 * pnCos	- input old value, output new value
 *
 * Outputs:
 * 
 * Side Effects:
 * - *pnSin, *pnCos are updated
 *
 *----------------------------------------------------------------------------
*/
static EAS_RESULT ReverbCalculateSinCos(EAS_I16 nPhase, EAS_I16 *pnSin, EAS_I16 *pnCos)
{
	EAS_I32	nTemp;
	EAS_I32	nNetAngle;

	//  -1 <=  nPhase  < 1
	// However, for the calculation, we need a value
	// that ranges from -1/2 to +1/2, so divide the phase by 2
	/*lint -e{702} shift for performance */
	nNetAngle = nPhase >> 1;	

	/*
	Implement the following
	sin(x) = (2-4*c)*x^2 + c + x
	cos(x) = (2-4*c)*x^2 + c - x

	  where  c = 1/sqrt(2)
	using the a0 + x*(a1 + x*a2) approach
	*/

	/* limit the input "angle" to be between -0.5 and +0.5 */
	if (nNetAngle > EG1_HALF)
	{
		nNetAngle = EG1_HALF;
	}
	else if (nNetAngle < EG1_MINUS_HALF)
	{
		nNetAngle = EG1_MINUS_HALF;
	}

	/* calculate sin */
	nTemp = EG1_ONE + MULT_EG1_EG1(REVERB_PAN_G2, nNetAngle);
	nTemp = REVERB_PAN_G0 + MULT_EG1_EG1(nTemp, nNetAngle);
	*pnSin = (EAS_I16) SATURATE_EG1(nTemp);

	/* calculate cos */
	nTemp = -EG1_ONE + MULT_EG1_EG1(REVERB_PAN_G2, nNetAngle);
	nTemp = REVERB_PAN_G0 + MULT_EG1_EG1(nTemp, nNetAngle);
	*pnCos = (EAS_I16) SATURATE_EG1(nTemp);

	return EAS_SUCCESS;
}	/* end ReverbCalculateSinCos */

/*----------------------------------------------------------------------------
 * Reverb
 *----------------------------------------------------------------------------
 * Purpose: 
 * apply reverb to the given signal
 *
 * Inputs: 
 * nNu
 * pnSin	- input old value, output new value
 * pnCos	- input old value, output new value
 *
 * Outputs:
 * number of samples actually reverberated
 * 
 * Side Effects:
 *
 *----------------------------------------------------------------------------
*/
static EAS_RESULT Reverb(S_REVERB_OBJECT *pReverbData, EAS_INT nNumSamplesToAdd, EAS_PCM *pOutputBuffer, EAS_PCM *pInputBuffer)
{
	EAS_I32	i;
	EAS_I32	nDelayOut;
	EAS_U16	nBase;

	EAS_U32	nAddr;
	EAS_I32	nTemp1;
	EAS_I32 nTemp2;
	EAS_I32 nApIn;
	EAS_I32 nApOut;

	EAS_I32 j;
	EAS_I32 nEarlyOut;

	EAS_I32 tempValue;


	// get the base address
	nBase = pReverbData->m_nBaseIndex;

	for (i=0; i < nNumSamplesToAdd; i++)
	{
		// ********** Left Allpass - start
		// left input = (left dry/4) + right feedback from previous period
		/*lint -e{702} use shift for performance */
		nApIn = ((*pInputBuffer++)>>2) + pReverbData->m_nRevOutFbkR;
//		nApIn = *pInputBuffer++;	// 1xxx test and debug ap

		// fetch allpass delay line out
		//nAddr = CIRCULAR(nBase, psAp0->m_zApOut, REVERB_BUFFER_MASK);
		nAddr = CIRCULAR(nBase, pReverbData->m_sAp0.m_zApOut, REVERB_BUFFER_MASK);
		nDelayOut = pReverbData->m_nDelayLine[nAddr];

		// calculate allpass feedforward; subtract the feedforward result
		nTemp1 = MULT_EG1_EG1(nApIn, pReverbData->m_sAp0.m_nApGain);
		nApOut = SATURATE(nDelayOut - nTemp1);			// allpass output

		// calculate allpass feedback; add the feedback result
		nTemp1 = MULT_EG1_EG1(nApOut, pReverbData->m_sAp0.m_nApGain);
		nTemp1 = SATURATE(nApIn + nTemp1);

		// inject into allpass delay
		nAddr = CIRCULAR(nBase, pReverbData->m_sAp0.m_zApIn, REVERB_BUFFER_MASK);
		pReverbData->m_nDelayLine[nAddr] = (EAS_PCM) nTemp1;

		// inject allpass output into delay line
		nAddr = CIRCULAR(nBase, pReverbData->m_zD0In, REVERB_BUFFER_MASK);
		pReverbData->m_nDelayLine[nAddr] = (EAS_PCM) nApOut;

		// ********** Left Allpass - end

		// ********** Right Allpass - start
		// right input = (right dry/4) + left feedback from previous period
		/*lint -e{702} use shift for performance */
		nApIn = ((*pInputBuffer++)>>2) + pReverbData->m_nRevOutFbkL;
//		nApIn = *pInputBuffer++;	// 1xxx test and debug ap

		// fetch allpass delay line out
		nAddr = CIRCULAR(nBase, pReverbData->m_sAp1.m_zApOut, REVERB_BUFFER_MASK);
		nDelayOut = pReverbData->m_nDelayLine[nAddr];

		// calculate allpass feedforward; subtract the feedforward result
		nTemp1 = MULT_EG1_EG1(nApIn, pReverbData->m_sAp1.m_nApGain);
		nApOut = SATURATE(nDelayOut - nTemp1);			// allpass output

		// calculate allpass feedback; add the feedback result
		nTemp1 = MULT_EG1_EG1(nApOut, pReverbData->m_sAp1.m_nApGain);
		nTemp1 = SATURATE(nApIn + nTemp1);

		// inject into allpass delay
		nAddr = CIRCULAR(nBase, pReverbData->m_sAp1.m_zApIn, REVERB_BUFFER_MASK);
		pReverbData->m_nDelayLine[nAddr] = (EAS_PCM) nTemp1;

		// inject allpass output into delay line
		nAddr = CIRCULAR(nBase, pReverbData->m_zD1In, REVERB_BUFFER_MASK);
		pReverbData->m_nDelayLine[nAddr] = (EAS_PCM) nApOut;

		// ********** Right Allpass - end

		// ********** D0 output - start
		// fetch delay line self out
		nAddr = CIRCULAR(nBase, pReverbData->m_zD0Self, REVERB_BUFFER_MASK);
		nDelayOut = pReverbData->m_nDelayLine[nAddr];

		// calculate delay line self out
		nTemp1 = MULT_EG1_EG1(nDelayOut, pReverbData->m_nSin);

		// fetch delay line cross out
		nAddr = CIRCULAR(nBase, pReverbData->m_zD1Cross, REVERB_BUFFER_MASK);
		nDelayOut = pReverbData->m_nDelayLine[nAddr];

		// calculate delay line self out
		nTemp2 = MULT_EG1_EG1(nDelayOut, pReverbData->m_nCos);

		// calculate unfiltered delay out
		nDelayOut = SATURATE(nTemp1 + nTemp2);

		// calculate lowpass filter (mixer scale factor included in LPF feedforward)
		nTemp1 = MULT_EG1_EG1(nDelayOut, pReverbData->m_nLpfFwd);

		nTemp2 = MULT_EG1_EG1(pReverbData->m_zLpf0, pReverbData->m_nLpfFbk);

		// calculate filtered delay out and simultaneously update LPF state variable
		// filtered delay output is stored in m_zLpf0
		pReverbData->m_zLpf0 = (EAS_PCM) SATURATE(nTemp1 + nTemp2);

		// ********** D0 output - end

		// ********** D1 output - start
		// fetch delay line self out
		nAddr = CIRCULAR(nBase, pReverbData->m_zD1Self, REVERB_BUFFER_MASK);
		nDelayOut = pReverbData->m_nDelayLine[nAddr];

		// calculate delay line self out
		nTemp1 = MULT_EG1_EG1(nDelayOut, pReverbData->m_nSin);

		// fetch delay line cross out
		nAddr = CIRCULAR(nBase, pReverbData->m_zD0Cross, REVERB_BUFFER_MASK);
		nDelayOut = pReverbData->m_nDelayLine[nAddr];

		// calculate delay line self out
		nTemp2 = MULT_EG1_EG1(nDelayOut, pReverbData->m_nCos);

		// calculate unfiltered delay out
		nDelayOut = SATURATE(nTemp1 + nTemp2);

		// calculate lowpass filter (mixer scale factor included in LPF feedforward)
		nTemp1 = MULT_EG1_EG1(nDelayOut, pReverbData->m_nLpfFwd);

		nTemp2 = MULT_EG1_EG1(pReverbData->m_zLpf1, pReverbData->m_nLpfFbk);

		// calculate filtered delay out and simultaneously update LPF state variable
		// filtered delay output is stored in m_zLpf1
		pReverbData->m_zLpf1 = (EAS_PCM)SATURATE(nTemp1 + nTemp2);

		// ********** D1 output - end

		// ********** mixer and feedback - start
		// sum is fedback to right input (R + L)
		pReverbData->m_nRevOutFbkL = 
			(EAS_PCM)SATURATE((EAS_I32)pReverbData->m_zLpf1 + (EAS_I32)pReverbData->m_zLpf0);

		// difference is feedback to left input (R - L)
		/*lint -e{685} lint complains that it can't saturate negative */
		pReverbData->m_nRevOutFbkR = 
			(EAS_PCM)SATURATE((EAS_I32)pReverbData->m_zLpf1 - (EAS_I32)pReverbData->m_zLpf0);

		// ********** mixer and feedback - end

		// ********** start early reflection generator, left
		//psEarly = &(pReverbData->m_sEarlyL);

		nEarlyOut = 0;

		for (j=0; j < REVERB_MAX_NUM_REFLECTIONS; j++)
		{
			// fetch delay line out
			//nAddr = CIRCULAR(nBase, psEarly->m_zDelay[j], REVERB_BUFFER_MASK);
			nAddr = CIRCULAR(nBase, pReverbData->m_sEarlyL.m_zDelay[j], REVERB_BUFFER_MASK);

			nDelayOut = pReverbData->m_nDelayLine[nAddr];

			// calculate reflection
			//nTemp1 = MULT_EG1_EG1(nDelayOut, psEarly->m_nGain[j]);
			nTemp1 = MULT_EG1_EG1(nDelayOut, pReverbData->m_sEarlyL.m_nGain[j]);

			nEarlyOut = SATURATE(nEarlyOut + nTemp1);

		}	// end for (j=0; j < REVERB_MAX_NUM_REFLECTIONS; j++)

		// apply lowpass to early reflections
		//nTemp1 = MULT_EG1_EG1(nEarlyOut, psEarly->m_nLpfFwd);
		nTemp1 = MULT_EG1_EG1(nEarlyOut, pReverbData->m_sEarlyL.m_nLpfFwd);

		//nTemp2 = MULT_EG1_EG1(psEarly->m_zLpf, psEarly->m_nLpfFbk);
		nTemp2 = MULT_EG1_EG1(pReverbData->m_sEarlyL.m_zLpf, pReverbData->m_sEarlyL.m_nLpfFbk);


		// calculate filtered out and simultaneously update LPF state variable
		// filtered output is stored in m_zLpf1
		//psEarly->m_zLpf = SATURATE(nTemp1 + nTemp2);
		pReverbData->m_sEarlyL.m_zLpf = (EAS_PCM) SATURATE(nTemp1 + nTemp2);

		// combine filtered early and late reflections for output
		//*pOutputBuffer++ = inL;
		//tempValue = SATURATE(psEarly->m_zLpf + pReverbData->m_nRevOutFbkL);
		tempValue = SATURATE((EAS_I32)pReverbData->m_sEarlyL.m_zLpf + (EAS_I32)pReverbData->m_nRevOutFbkL);
		//scale reverb output by wet level
		/*lint -e{701} use shift for performance */
		tempValue = MULT_EG1_EG1(tempValue, (pReverbData->m_nWet<<1));
		//sum with output buffer
		tempValue += *pOutputBuffer;
		*pOutputBuffer++ = (EAS_PCM)SATURATE(tempValue);

		// ********** end early reflection generator, left

		// ********** start early reflection generator, right
		//psEarly = &(pReverbData->m_sEarlyR);

		nEarlyOut = 0;

		for (j=0; j < REVERB_MAX_NUM_REFLECTIONS; j++)
		{
			// fetch delay line out
			nAddr = CIRCULAR(nBase, pReverbData->m_sEarlyR.m_zDelay[j], REVERB_BUFFER_MASK);
			nDelayOut = pReverbData->m_nDelayLine[nAddr];

			// calculate reflection
			nTemp1 = MULT_EG1_EG1(nDelayOut, pReverbData->m_sEarlyR.m_nGain[j]);

			nEarlyOut = SATURATE(nEarlyOut + nTemp1);

		}	// end for (j=0; j < REVERB_MAX_NUM_REFLECTIONS; j++)

		// apply lowpass to early reflections
		nTemp1 = MULT_EG1_EG1(nEarlyOut, pReverbData->m_sEarlyR.m_nLpfFwd);

		nTemp2 = MULT_EG1_EG1(pReverbData->m_sEarlyR.m_zLpf, pReverbData->m_sEarlyR.m_nLpfFbk);

		// calculate filtered out and simultaneously update LPF state variable
		// filtered output is stored in m_zLpf1
		pReverbData->m_sEarlyR.m_zLpf = (EAS_PCM)SATURATE(nTemp1 + nTemp2);

		// combine filtered early and late reflections for output
		//*pOutputBuffer++ = inR;
		tempValue = SATURATE((EAS_I32)pReverbData->m_sEarlyR.m_zLpf + (EAS_I32)pReverbData->m_nRevOutFbkR);
		//scale reverb output by wet level
		/*lint -e{701} use shift for performance */
		tempValue = MULT_EG1_EG1(tempValue, (pReverbData->m_nWet << 1));
		//sum with output buffer
		tempValue = tempValue + *pOutputBuffer;
		*pOutputBuffer++ = (EAS_PCM)SATURATE(tempValue);

		// ********** end early reflection generator, right

		// decrement base addr for next sample period
		nBase--;

		pReverbData->m_nSin += pReverbData->m_nSinIncrement;
		pReverbData->m_nCos += pReverbData->m_nCosIncrement;

	}	// end for (i=0; i < nNumSamplesToAdd; i++)

	// store the most up to date version
	pReverbData->m_nBaseIndex = nBase;

	return EAS_SUCCESS;
}	/* end Reverb */



/*----------------------------------------------------------------------------
 * ReverbShutdown()
 *----------------------------------------------------------------------------
 * Purpose: 
 * Initializes the Reverb effect.
 *
 * Inputs:
 * pInstData		- handle to instance data
 *		
 * Outputs:
 * 
 *
 * Side Effects:
 *
 *----------------------------------------------------------------------------
*/
static EAS_RESULT ReverbShutdown (EAS_DATA_HANDLE pEASData, EAS_VOID_PTR pInstData)
{
	/* check Configuration Module for static memory allocation */
	if (!pEASData->staticMemoryModel)
		EAS_HWFree(pEASData->hwInstData, pInstData);
	return EAS_SUCCESS;
} /* end ReverbShutdown */

/*----------------------------------------------------------------------------
 * ReverbGetParam()
 *----------------------------------------------------------------------------
 * Purpose: 
 * Get a Reverb parameter
 *
 * Inputs:
 * pInstData		- handle to instance data
 * param			- parameter index
 * *pValue			- pointer to variable to hold retrieved value
 *		
 * Outputs:
 * 
 *
 * Side Effects:
 *
 *----------------------------------------------------------------------------
*/
static EAS_RESULT ReverbGetParam (EAS_VOID_PTR pInstData, EAS_I32 param, EAS_I32 *pValue)
{
	S_REVERB_OBJECT *p;

	p = (S_REVERB_OBJECT*) pInstData;

	switch (param)
	{
		case EAS_PARAM_REVERB_BYPASS:
			*pValue = (EAS_I32) p->m_bBypass;
			break;
		case EAS_PARAM_REVERB_PRESET:
			*pValue = (EAS_I8) p->m_nCurrentRoom;
			break;
		case EAS_PARAM_REVERB_WET:
			*pValue = p->m_nWet;
			break;
		case EAS_PARAM_REVERB_DRY:
			*pValue = p->m_nDry;
			break;
		default:
			return EAS_ERROR_INVALID_PARAMETER;
	}
	return EAS_SUCCESS;
} /* end ReverbGetParam */


/*----------------------------------------------------------------------------
 * ReverbSetParam()
 *----------------------------------------------------------------------------
 * Purpose: 
 * Set a Reverb parameter
 *
 * Inputs:
 * pInstData		- handle to instance data
 * param			- parameter index
 * *pValue			- new paramter value
 *		
 * Outputs:
 * 
 *
 * Side Effects:
 *
 *----------------------------------------------------------------------------
*/
static EAS_RESULT ReverbSetParam (EAS_VOID_PTR pInstData, EAS_I32 param, EAS_I32 value)
{
	S_REVERB_OBJECT *p;

	p = (S_REVERB_OBJECT*) pInstData;

	switch (param)
	{
		case EAS_PARAM_REVERB_BYPASS:
			p->m_bBypass = (EAS_BOOL) value;
			break;
		case EAS_PARAM_REVERB_PRESET:
			if(value!=EAS_PARAM_REVERB_LARGE_HALL && value!=EAS_PARAM_REVERB_HALL && 
				value!=EAS_PARAM_REVERB_CHAMBER && value!=EAS_PARAM_REVERB_ROOM)
				return EAS_ERROR_INVALID_PARAMETER;
			p->m_nNextRoom = (EAS_I16)value;
			break;
		case EAS_PARAM_REVERB_WET:
			if(value>EAS_REVERB_WET_MAX || value<EAS_REVERB_WET_MIN)
				return EAS_ERROR_INVALID_PARAMETER;
			p->m_nWet = (EAS_I16)value;
			break;
		case EAS_PARAM_REVERB_DRY:
			if(value>EAS_REVERB_DRY_MAX || value<EAS_REVERB_DRY_MIN)
				return EAS_ERROR_INVALID_PARAMETER;
			p->m_nDry = (EAS_I16)value;
			break;
		default:
			return EAS_ERROR_INVALID_PARAMETER;
	}
	return EAS_SUCCESS;
} /* end ReverbSetParam */


/*----------------------------------------------------------------------------
 * ReverbUpdateRoom
 *----------------------------------------------------------------------------
 * Purpose: 
 * Update the room's preset parameters as required
 *
 * Inputs: 
 *
 * Outputs:
 * 
 * 
 * Side Effects:
 * - reverb paramters (fbk, fwd, etc) will be changed
 * - m_nCurrentRoom := m_nNextRoom
 *----------------------------------------------------------------------------
*/
static EAS_RESULT ReverbUpdateRoom(S_REVERB_OBJECT *pReverbData)
{
	EAS_INT temp;

	S_REVERB_PRESET *pPreset = &pReverbData->m_sPreset.m_sPreset[pReverbData->m_nNextRoom];

	pReverbData->m_nLpfFwd = pPreset->m_nLpfFwd;
	pReverbData->m_nLpfFbk = pPreset->m_nLpfFbk;

	pReverbData->m_nEarly = pPreset->m_nEarly;
	pReverbData->m_nWet = pPreset->m_nWet;
	pReverbData->m_nDry = pPreset->m_nDry;


	pReverbData->m_nMaxExcursion = pPreset->m_nMaxExcursion;
	//stored as time based, convert to sample based
	temp = pPreset->m_nXfadeInterval;
	/*lint -e{702} shift for performance */
	temp = (temp * _OUTPUT_SAMPLE_RATE) >> 16;
	pReverbData->m_nXfadeInterval = (EAS_U16) temp;
	//gpsReverbObject->m_nXfadeInterval = pPreset->m_nXfadeInterval;
	pReverbData->m_sAp0.m_nApGain = pPreset->m_nAp0_ApGain;
	//stored as time based, convert to absolute sample value
	temp = pPreset->m_nAp0_ApOut;
	/*lint -e{702} shift for performance */
	temp = (temp * _OUTPUT_SAMPLE_RATE) >> 16;
	pReverbData->m_sAp0.m_zApOut = (EAS_U16) (pReverbData->m_sAp0.m_zApIn + temp);
	//gpsReverbObject->m_sAp0.m_zApOut = pPreset->m_nAp0_ApOut;
	pReverbData->m_sAp1.m_nApGain = pPreset->m_nAp1_ApGain;
	//stored as time based, convert to absolute sample value
	temp = pPreset->m_nAp1_ApOut;
	/*lint -e{702} shift for performance */
	temp = (temp * _OUTPUT_SAMPLE_RATE) >> 16;
	pReverbData->m_sAp1.m_zApOut = (EAS_U16) (pReverbData->m_sAp1.m_zApIn + temp);
	//gpsReverbObject->m_sAp1.m_zApOut = pPreset->m_nAp1_ApOut;

	pReverbData->m_nCurrentRoom = pReverbData->m_nNextRoom;

	return EAS_SUCCESS;
	
}	/* end ReverbUpdateRoom */


/*----------------------------------------------------------------------------
 * ReverbReadInPresets()
 *----------------------------------------------------------------------------
 * Purpose: sets global reverb preset bank to defaults
 * 
 * Inputs: 
 *			
 * Outputs:
 *
 *----------------------------------------------------------------------------
*/
static EAS_RESULT ReverbReadInPresets(S_REVERB_OBJECT *pReverbData)
{

	int preset = 0;
	int defaultPreset = 0;

	//now init any remaining presets to defaults
	for (defaultPreset = preset; defaultPreset < REVERB_MAX_ROOM_TYPE; defaultPreset++)
	{
		S_REVERB_PRESET *pPreset = &pReverbData->m_sPreset.m_sPreset[defaultPreset];
		if (defaultPreset == 0 || defaultPreset > REVERB_MAX_ROOM_TYPE-1)
		{
			pPreset->m_nLpfFbk = 8307;
			pPreset->m_nLpfFwd = 14768;
			pPreset->m_nEarly = 0;
			pPreset->m_nWet = 27690;
			pPreset->m_nDry = 32767;
			pPreset->m_nEarlyL_LpfFbk = 3692;
			pPreset->m_nEarlyL_LpfFwd = 29075;
			pPreset->m_nEarlyL_Delay0 = 922;
			pPreset->m_nEarlyL_Gain0 = 22152;
			pPreset->m_nEarlyL_Delay1 = 1462;
			pPreset->m_nEarlyL_Gain1 = 17537;
			pPreset->m_nEarlyL_Delay2 = 0;
			pPreset->m_nEarlyL_Gain2 = 14768;
			pPreset->m_nEarlyL_Delay3 = 1221;
			pPreset->m_nEarlyL_Gain3 = 14307;
			pPreset->m_nEarlyL_Delay4 = 0;
			pPreset->m_nEarlyL_Gain4 = 13384;
			pPreset->m_nEarlyR_Delay0 = 502;
			pPreset->m_nEarlyR_Gain0 = 20306;
			pPreset->m_nEarlyR_Delay1 = 1762;
			pPreset->m_nEarlyR_Gain1 = 17537;
			pPreset->m_nEarlyR_Delay2 = 0;
			pPreset->m_nEarlyR_Gain2 = 14768;
			pPreset->m_nEarlyR_Delay3 = 0;
			pPreset->m_nEarlyR_Gain3 = 16153;
			pPreset->m_nEarlyR_Delay4 = 0;
			pPreset->m_nEarlyR_Gain4 = 13384;
			pPreset->m_nMaxExcursion = 127;
			pPreset->m_nXfadeInterval = 6388;
			pPreset->m_nAp0_ApGain = 15691;
			pPreset->m_nAp0_ApOut = 711;
			pPreset->m_nAp1_ApGain = 17999;
			pPreset->m_nAp1_ApOut = 1113;
			pPreset->m_rfu4 = 0;
			pPreset->m_rfu5 = 0;
			pPreset->m_rfu6 = 0;
			pPreset->m_rfu7 = 0;
			pPreset->m_rfu8 = 0;
			pPreset->m_rfu9 = 0;
			pPreset->m_rfu10 = 0;
		}
		else if (defaultPreset == 1)
		{
			pPreset->m_nLpfFbk = 6461;
			pPreset->m_nLpfFwd = 14307;
			pPreset->m_nEarly = 0;
			pPreset->m_nWet = 27690;
			pPreset->m_nDry = 32767;
			pPreset->m_nEarlyL_LpfFbk = 3692;
			pPreset->m_nEarlyL_LpfFwd = 29075;
			pPreset->m_nEarlyL_Delay0 = 922;
			pPreset->m_nEarlyL_Gain0 = 22152;
			pPreset->m_nEarlyL_Delay1 = 1462;
			pPreset->m_nEarlyL_Gain1 = 17537;
			pPreset->m_nEarlyL_Delay2 = 0;
			pPreset->m_nEarlyL_Gain2 = 14768;
			pPreset->m_nEarlyL_Delay3 = 1221;
			pPreset->m_nEarlyL_Gain3 = 14307;
			pPreset->m_nEarlyL_Delay4 = 0;
			pPreset->m_nEarlyL_Gain4 = 13384;
			pPreset->m_nEarlyR_Delay0 = 502;
			pPreset->m_nEarlyR_Gain0 = 20306;
			pPreset->m_nEarlyR_Delay1 = 1762;
			pPreset->m_nEarlyR_Gain1 = 17537;
			pPreset->m_nEarlyR_Delay2 = 0;
			pPreset->m_nEarlyR_Gain2 = 14768;
			pPreset->m_nEarlyR_Delay3 = 0;
			pPreset->m_nEarlyR_Gain3 = 16153;
			pPreset->m_nEarlyR_Delay4 = 0;
			pPreset->m_nEarlyR_Gain4 = 13384;
			pPreset->m_nMaxExcursion = 127;
			pPreset->m_nXfadeInterval = 6391;
			pPreset->m_nAp0_ApGain = 15230;
			pPreset->m_nAp0_ApOut = 708;
			pPreset->m_nAp1_ApGain = 9692;
			pPreset->m_nAp1_ApOut = 1113;
			pPreset->m_rfu4 = 0;
			pPreset->m_rfu5 = 0;
			pPreset->m_rfu6 = 0;
			pPreset->m_rfu7 = 0;
			pPreset->m_rfu8 = 0;
			pPreset->m_rfu9 = 0;
			pPreset->m_rfu10 = 0;
		}
		else if (defaultPreset == 2)
		{
			pPreset->m_nLpfFbk = 5077;
			pPreset->m_nLpfFwd = 12922;
			pPreset->m_nEarly = 0;
			pPreset->m_nWet = 24460;
			pPreset->m_nDry = 32767;
			pPreset->m_nEarlyL_LpfFbk = 3692;
			pPreset->m_nEarlyL_LpfFwd = 29075;
			pPreset->m_nEarlyL_Delay0 = 922;
			pPreset->m_nEarlyL_Gain0 = 22152;
			pPreset->m_nEarlyL_Delay1 = 1462;
			pPreset->m_nEarlyL_Gain1 = 17537;
			pPreset->m_nEarlyL_Delay2 = 0;
			pPreset->m_nEarlyL_Gain2 = 14768;
			pPreset->m_nEarlyL_Delay3 = 1221;
			pPreset->m_nEarlyL_Gain3 = 14307;
			pPreset->m_nEarlyL_Delay4 = 0;
			pPreset->m_nEarlyL_Gain4 = 13384;
			pPreset->m_nEarlyR_Delay0 = 502;
			pPreset->m_nEarlyR_Gain0 = 20306;
			pPreset->m_nEarlyR_Delay1 = 1762;
			pPreset->m_nEarlyR_Gain1 = 17537;
			pPreset->m_nEarlyR_Delay2 = 0;
			pPreset->m_nEarlyR_Gain2 = 14768;
			pPreset->m_nEarlyR_Delay3 = 0;
			pPreset->m_nEarlyR_Gain3 = 16153;
			pPreset->m_nEarlyR_Delay4 = 0;
			pPreset->m_nEarlyR_Gain4 = 13384;
			pPreset->m_nMaxExcursion = 127;
			pPreset->m_nXfadeInterval = 6449;
			pPreset->m_nAp0_ApGain = 15691;
			pPreset->m_nAp0_ApOut = 774;
			pPreset->m_nAp1_ApGain = 15691;
			pPreset->m_nAp1_ApOut = 1113;
			pPreset->m_rfu4 = 0;
			pPreset->m_rfu5 = 0;
			pPreset->m_rfu6 = 0;
			pPreset->m_rfu7 = 0;
			pPreset->m_rfu8 = 0;
			pPreset->m_rfu9 = 0;
			pPreset->m_rfu10 = 0;
		}
		else if (defaultPreset == 3)
		{
			pPreset->m_nLpfFbk = 5077;
			pPreset->m_nLpfFwd = 11076;
			pPreset->m_nEarly = 0;
			pPreset->m_nWet = 23075;
			pPreset->m_nDry = 32767;
			pPreset->m_nEarlyL_LpfFbk = 3692;
			pPreset->m_nEarlyL_LpfFwd = 29075;
			pPreset->m_nEarlyL_Delay0 = 922;
			pPreset->m_nEarlyL_Gain0 = 22152;
			pPreset->m_nEarlyL_Delay1 = 1462;
			pPreset->m_nEarlyL_Gain1 = 17537;
			pPreset->m_nEarlyL_Delay2 = 0;
			pPreset->m_nEarlyL_Gain2 = 14768;
			pPreset->m_nEarlyL_Delay3 = 1221;
			pPreset->m_nEarlyL_Gain3 = 14307;
			pPreset->m_nEarlyL_Delay4 = 0;
			pPreset->m_nEarlyL_Gain4 = 13384;
			pPreset->m_nEarlyR_Delay0 = 502;
			pPreset->m_nEarlyR_Gain0 = 20306;
			pPreset->m_nEarlyR_Delay1 = 1762;
			pPreset->m_nEarlyR_Gain1 = 17537;
			pPreset->m_nEarlyR_Delay2 = 0;
			pPreset->m_nEarlyR_Gain2 = 14768;
			pPreset->m_nEarlyR_Delay3 = 0;
			pPreset->m_nEarlyR_Gain3 = 16153;
			pPreset->m_nEarlyR_Delay4 = 0;
			pPreset->m_nEarlyR_Gain4 = 13384;
			pPreset->m_nMaxExcursion = 127;
			pPreset->m_nXfadeInterval = 6470;	//6483;
			pPreset->m_nAp0_ApGain = 14768;
			pPreset->m_nAp0_ApOut = 792;
			pPreset->m_nAp1_ApGain = 15783;
			pPreset->m_nAp1_ApOut = 1113;
			pPreset->m_rfu4 = 0;
			pPreset->m_rfu5 = 0;
			pPreset->m_rfu6 = 0;
			pPreset->m_rfu7 = 0;
			pPreset->m_rfu8 = 0;
			pPreset->m_rfu9 = 0;
			pPreset->m_rfu10 = 0;

		}
	}

	return EAS_SUCCESS;
}