/*
 *	File:		StereoChorus.cpp
 *	
 *	Version:	1.0
 * 
 *	Created:	2/7/22
 *	
 *	Copyright:  Copyright © 2022 Airwindows, Airwindows uses the MIT license
 * 
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/*=============================================================================
 StereoChorus.cpp
 
 =============================================================================*/
#include "StereoChorus.h"


//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

COMPONENT_ENTRY(StereoChorus)


//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
//	StereoChorus::StereoChorus
//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
StereoChorus::StereoChorus(AudioUnit component)
: AUEffectBase(component)
{
	CreateElements();
	Globals()->UseIndexedParameters(kNumberOfParameters);
	SetParameter(kParam_One, kDefaultValue_ParamOne );
	SetParameter(kParam_Two, kDefaultValue_ParamTwo );
	
#if AU_DEBUG_DISPATCHER
	mDebugDispatcher = new AUDebugDispatcher (this);
#endif
	
}


//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
//	StereoChorus::GetParameterValueStrings
//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
ComponentResult			StereoChorus::GetParameterValueStrings(AudioUnitScope		inScope,
															   AudioUnitParameterID	inParameterID,
															   CFArrayRef *		outStrings)
{
	
    return kAudioUnitErr_InvalidProperty;
}



//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
//	StereoChorus::GetParameterInfo
//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
ComponentResult			StereoChorus::GetParameterInfo(AudioUnitScope		inScope,
													   AudioUnitParameterID	inParameterID,
													   AudioUnitParameterInfo	&outParameterInfo )
{
	ComponentResult result = noErr;
	
	outParameterInfo.flags = 	kAudioUnitParameterFlag_IsWritable
	|		kAudioUnitParameterFlag_IsReadable;
    
    if (inScope == kAudioUnitScope_Global) {
        switch(inParameterID)
        {
			case kParam_One:
                AUBase::FillInParameterName (outParameterInfo, kParameterOneName, false);
                outParameterInfo.unit = kAudioUnitParameterUnit_Generic;
                outParameterInfo.minValue = 0.0;
                outParameterInfo.maxValue = 1.0;
                outParameterInfo.defaultValue = kDefaultValue_ParamOne;
                break;
            case kParam_Two:
                AUBase::FillInParameterName (outParameterInfo, kParameterTwoName, false);
                outParameterInfo.unit = kAudioUnitParameterUnit_Generic;
                outParameterInfo.minValue = 0.0;
                outParameterInfo.maxValue = 1.0;
                outParameterInfo.defaultValue = kDefaultValue_ParamTwo;
                break;
			default:
                result = kAudioUnitErr_InvalidParameter;
                break;
		}
	} else {
        result = kAudioUnitErr_InvalidParameter;
    }
    
	
	
	return result;
}

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
//	StereoChorus::GetPropertyInfo
//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
ComponentResult			StereoChorus::GetPropertyInfo (AudioUnitPropertyID	inID,
													   AudioUnitScope		inScope,
													   AudioUnitElement	inElement,
													   UInt32 &		outDataSize,
													   Boolean &		outWritable)
{
	return AUEffectBase::GetPropertyInfo (inID, inScope, inElement, outDataSize, outWritable);
}

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
// state that plugin supports only stereo-in/stereo-out processing
UInt32 StereoChorus::SupportedNumChannels(const AUChannelInfo ** outInfo)
{
	if (outInfo != NULL)
	{
		static AUChannelInfo info;
		info.inChannels = 2;
		info.outChannels = 2;
		*outInfo = &info;
	}
	
	return 1;
}

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
//	StereoChorus::GetProperty
//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
ComponentResult			StereoChorus::GetProperty(	AudioUnitPropertyID inID,
												  AudioUnitScope 		inScope,
												  AudioUnitElement 	inElement,
												  void *			outData )
{
	return AUEffectBase::GetProperty (inID, inScope, inElement, outData);
}

//	StereoChorus::Initialize
//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
ComponentResult StereoChorus::Initialize()
{
    ComponentResult result = AUEffectBase::Initialize();
    if (result == noErr)
        Reset(kAudioUnitScope_Global, 0);
    return result;
}

#pragma mark ____StereoChorusEffectKernel



//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
//	StereoChorus::StereoChorusKernel::Reset()
//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
ComponentResult		StereoChorus::Reset(AudioUnitScope inScope, AudioUnitElement inElement)
{
	for(int count = 0; count < 65535; count++) {pL[count] = 0;pR[count] = 0;}
	sweepL = 3.141592653589793238 / 2.7;
	sweepR = 3.141592653589793238;
	gcount = 0;
	airPrevL = 0.0;
	airEvenL = 0.0;
	airOddL = 0.0;
	airFactorL = 0.0;
	airPrevR = 0.0;
	airEvenR = 0.0;
	airOddR = 0.0;
	airFactorR = 0.0;
	flip = false;
	
	for(int count = 0; count < 6; count++) {lastRefL[count] = 0.0;lastRefR[count] = 0.0;}
	cycle = 0;
	
	fpdL = 1.0; while (fpdL < 16386) fpdL = rand()*UINT32_MAX;
	fpdR = 1.0; while (fpdR < 16386) fpdR = rand()*UINT32_MAX;
	return noErr;
}

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
//	StereoChorus::ProcessBufferLists
//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
OSStatus		StereoChorus::ProcessBufferLists(AudioUnitRenderActionFlags & ioActionFlags,
												 const AudioBufferList & inBuffer,
												 AudioBufferList & outBuffer,
												 UInt32 			inFramesToProcess)
{
	Float32 * inputL = (Float32*)(inBuffer.mBuffers[0].mData);
	Float32 * inputR = (Float32*)(inBuffer.mBuffers[1].mData);
	Float32 * outputL = (Float32*)(outBuffer.mBuffers[0].mData);
	Float32 * outputR = (Float32*)(outBuffer.mBuffers[1].mData);
	UInt32 nSampleFrames = inFramesToProcess;
	
	double overallscale = 1.0;
	overallscale /= 44100.0;
	overallscale *= GetSampleRate();
	
	int cycleEnd = floor(overallscale);
	if (cycleEnd < 1) cycleEnd = 1;
	if (cycleEnd > 4) cycleEnd = 4;
	//this is going to be 2 for 88.1 or 96k, 3 for silly people, 4 for 176 or 192k
	if (cycle > cycleEnd-1) cycle = cycleEnd-1; //sanity check
	
	double speed = pow(0.32+(GetParameter( kParam_One )/6),10);
	double depth = (GetParameter( kParam_Two )/60) / speed;
	double tupi = 3.141592653589793238 * 2.0;
	
	while (nSampleFrames-- > 0) {
		double inputSampleL = *inputL;
		double inputSampleR = *inputR;
		if (fabs(inputSampleL)<1.18e-23) inputSampleL = fpdL * 1.18e-17;
		if (fabs(inputSampleR)<1.18e-23) inputSampleR = fpdR * 1.18e-17;
		
		cycle++;
		if (cycle == cycleEnd) { //hit the end point and we do a chorus sample
			//assign working variables
			airFactorL = airPrevL - inputSampleL;
			if (flip) {airEvenL += airFactorL; airOddL -= airFactorL; airFactorL = airEvenL;}
			else {airOddL += airFactorL; airEvenL -= airFactorL; airFactorL = airOddL;}
			airOddL = (airOddL - ((airOddL - airEvenL)/256.0)) / 1.0001;
			airEvenL = (airEvenL - ((airEvenL - airOddL)/256.0)) / 1.0001;
			airPrevL = inputSampleL;
			inputSampleL += airFactorL;
			//left
			airFactorR = airPrevR - inputSampleR;
			if (flip) {airEvenR += airFactorR; airOddR -= airFactorR; airFactorR = airEvenR;}
			else {airOddR += airFactorR; airEvenR -= airFactorR; airFactorR = airOddR;}
			airOddR = (airOddR - ((airOddR - airEvenR)/256.0)) / 1.0001;
			airEvenR = (airEvenR - ((airEvenR - airOddR)/256.0)) / 1.0001;
			airPrevR = inputSampleR;
			inputSampleR += airFactorR;
			//right
			flip = !flip;
			//air, compensates for loss of highs in flanger's interpolation
			
			int tempL = 0;
			int tempR = 0;
			if (gcount < 1 || gcount > 32760) {gcount = 32760;}
			int count = gcount;
			pL[count+32760] = pL[count] = (int)(inputSampleL*8388352.0);
			//double buffer -8388352 to 8388352 is equal to 24 bit linear space
			double offset = depth + (depth * sin(sweepL));
			count += (int)floor(offset);
			tempL += (int)(pL[count] * (1-(offset-floor(offset)))); //less as value moves away from .0
			tempL += pL[count+1]; //we can assume always using this in one way or another?
			tempL += (int)(pL[count+2] * (offset-floor(offset))); //greater as value moves away from .0
			tempL -= (int)(((pL[count]-pL[count+1])-(pL[count+1]-pL[count+2]))/50); //interpolation hacks 'r us
			//left
			
			count = gcount;
			pR[count+32760] = pR[count] = (int)(inputSampleR*8388352.0);
			//double buffer -8388352 to 8388352 is equal to 24 bit linear space
			offset = depth + (depth * sin(sweepR));
			count += (int)floor(offset);
			tempR += (int)(pR[count] * (1-(offset-floor(offset)))); //less as value moves away from .0
			tempR += pR[count+1]; //we can assume always using this in one way or another?
			tempR += (int)(pR[count+2] * (offset-floor(offset))); //greater as value moves away from .0
			tempR -= (int)(((pR[count]-pR[count+1])-(pR[count+1]-pR[count+2]))/50); //interpolation hacks 'r us
			//right
			
			sweepL += speed;
			sweepR += speed;
			if (sweepL > tupi){sweepL -= tupi;}
			if (sweepR > tupi){sweepR -= tupi;}
			gcount--;
			//still scrolling through the samples, remember
			
			inputSampleL = ((double)(tempL/16776704.0));
			inputSampleR = ((double)(tempR/16776704.0));
			if (cycleEnd == 4) {
				lastRefL[0] = lastRefL[4]; //start from previous last
				lastRefL[2] = (lastRefL[0] + inputSampleL)/2; //half
				lastRefL[1] = (lastRefL[0] + lastRefL[2])/2; //one quarter
				lastRefL[3] = (lastRefL[2] + inputSampleL)/2; //three quarters
				lastRefL[4] = inputSampleL; //full
				lastRefR[0] = lastRefR[4]; //start from previous last
				lastRefR[2] = (lastRefR[0] + inputSampleR)/2; //half
				lastRefR[1] = (lastRefR[0] + lastRefR[2])/2; //one quarter
				lastRefR[3] = (lastRefR[2] + inputSampleR)/2; //three quarters
				lastRefR[4] = inputSampleR; //full
			}
			if (cycleEnd == 3) {
				lastRefL[0] = lastRefL[3]; //start from previous last
				lastRefL[2] = (lastRefL[0]+lastRefL[0]+inputSampleL)/3; //third
				lastRefL[1] = (lastRefL[0]+inputSampleL+inputSampleL)/3; //two thirds
				lastRefL[3] = inputSampleL; //full
				lastRefR[0] = lastRefR[3]; //start from previous last
				lastRefR[2] = (lastRefR[0]+lastRefR[0]+inputSampleR)/3; //third
				lastRefR[1] = (lastRefR[0]+inputSampleR+inputSampleR)/3; //two thirds
				lastRefR[3] = inputSampleR; //full
			}
			if (cycleEnd == 2) {
				lastRefL[0] = lastRefL[2]; //start from previous last
				lastRefL[1] = (lastRefL[0] + inputSampleL)/2; //half
				lastRefL[2] = inputSampleL; //full
				lastRefR[0] = lastRefR[2]; //start from previous last
				lastRefR[1] = (lastRefR[0] + inputSampleR)/2; //half
				lastRefR[2] = inputSampleR; //full
			}
			if (cycleEnd == 1) {
				lastRefL[0] = inputSampleL;
				lastRefR[0] = inputSampleR;
			}
			cycle = 0; //reset
			inputSampleL = lastRefL[cycle];
			inputSampleR = lastRefR[cycle];
		} else {
			inputSampleL = lastRefL[cycle];
			inputSampleR = lastRefR[cycle];
			//we are going through our references now
		}
		
		//begin 32 bit stereo floating point dither
		int expon; frexpf((float)inputSampleL, &expon);
		fpdL ^= fpdL << 13; fpdL ^= fpdL >> 17; fpdL ^= fpdL << 5;
		inputSampleL += ((double(fpdL)-uint32_t(0x7fffffff)) * 5.5e-36l * pow(2,expon+62));
		frexpf((float)inputSampleR, &expon);
		fpdR ^= fpdR << 13; fpdR ^= fpdR >> 17; fpdR ^= fpdR << 5;
		inputSampleR += ((double(fpdR)-uint32_t(0x7fffffff)) * 5.5e-36l * pow(2,expon+62));
		//end 32 bit stereo floating point dither
		
		*outputL = inputSampleL;
		*outputR = inputSampleR;
		//direct stereo out
		
		inputL += 1;
		inputR += 1;
		outputL += 1;
		outputR += 1;
	}
	return noErr;
}

