/*
*	File:		BiquadStereo.cpp
*	
*	Version:	1.0
* 
*	Created:	6/29/19
*	
*	Copyright:  Copyright © 2019 Airwindows, Airwindows uses the MIT license
* 
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/*=============================================================================
	BiquadStereo.cpp
	
=============================================================================*/
#include "BiquadStereo.h"


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

COMPONENT_ENTRY(BiquadStereo)


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


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



//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
//	BiquadStereo::GetParameterInfo
//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
ComponentResult			BiquadStereo::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_Indexed;
                outParameterInfo.minValue = 1.0;
                outParameterInfo.maxValue = 4.0;
                outParameterInfo.defaultValue = kDefaultValue_ParamOne;
                break;
            case kParam_Two:
                AUBase::FillInParameterName (outParameterInfo, kParameterTwoName, false);
                outParameterInfo.unit = kAudioUnitParameterUnit_Generic;
				outParameterInfo.flags |= kAudioUnitParameterFlag_DisplayLogarithmic;
                outParameterInfo.minValue = 0.0001;
                outParameterInfo.maxValue = 1.0;
                outParameterInfo.defaultValue = kDefaultValue_ParamTwo;
                break;
            case kParam_Three:
                AUBase::FillInParameterName (outParameterInfo, kParameterThreeName, false);
                outParameterInfo.unit = kAudioUnitParameterUnit_Generic;
				outParameterInfo.flags |= kAudioUnitParameterFlag_DisplayLogarithmic;
                outParameterInfo.minValue = 0.01;
                outParameterInfo.maxValue = 30.0;
                outParameterInfo.defaultValue = kDefaultValue_ParamThree;
                break;
			case kParam_Four:
                AUBase::FillInParameterName (outParameterInfo, kParameterFourName, false);
                outParameterInfo.unit = kAudioUnitParameterUnit_Generic;
                outParameterInfo.minValue = -1.0;
                outParameterInfo.maxValue = 1.0;
                outParameterInfo.defaultValue = kDefaultValue_ParamFour;
                break;
			default:
                result = kAudioUnitErr_InvalidParameter;
                break;
            }
	} else {
        result = kAudioUnitErr_InvalidParameter;
    }
    


	return result;
}

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
//	BiquadStereo::GetPropertyInfo
//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
ComponentResult			BiquadStereo::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 BiquadStereo::SupportedNumChannels(const AUChannelInfo ** outInfo)
{
	if (outInfo != NULL)
	{
		static AUChannelInfo info;
		info.inChannels = 2;
		info.outChannels = 2;
		*outInfo = &info;
	}

	return 1;
}

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

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

#pragma mark ____BiquadStereoEffectKernel



//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
//	BiquadStereo::BiquadStereoKernel::Reset()
//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
ComponentResult		BiquadStereo::Reset(AudioUnitScope inScope, AudioUnitElement inElement)
{
	for (int x = 0; x < 11; x++) {biquad[x] = 0.0;}
	fpdL = 1.0; while (fpdL < 16386) fpdL = rand()*UINT32_MAX;
	fpdR = 1.0; while (fpdR < 16386) fpdR = rand()*UINT32_MAX;
	return noErr;
}

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
//	BiquadStereo::ProcessBufferLists
//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
OSStatus		BiquadStereo::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 type = GetParameter( kParam_One);
	
	biquad[0] = GetParameter( kParam_Two )*0.499;
	if (biquad[0] < 0.0001) biquad[0] = 0.0001;
	
    biquad[1] = GetParameter( kParam_Three );
	if (biquad[1] < 0.0001) biquad[1] = 0.0001;
	
	Float64 wet = GetParameter( kParam_Four );
	
	//biquad contains these values:
	//[0] is frequency: 0.000001 to 0.499999 is near-zero to near-Nyquist
	//[1] is resonance, 0.7071 is Butterworth. Also can't be zero
	//[2] is a0 but you need distinct ones for additional biquad instances so it's here
	//[3] is a1 but you need distinct ones for additional biquad instances so it's here
	//[4] is a2 but you need distinct ones for additional biquad instances so it's here
	//[5] is b1 but you need distinct ones for additional biquad instances so it's here
	//[6] is b2 but you need distinct ones for additional biquad instances so it's here
	//[7] is LEFT stored delayed sample (freq and res are stored so you can move them sample by sample)
	//[8] is LEFT stored delayed sample (you have to include the coefficient making code if you do that)
	//[9] is RIGHT stored delayed sample (freq and res are stored so you can move them sample by sample)
	//[10] is RIGHT stored delayed sample (you have to include the coefficient making code if you do that)
	
	//to build a dedicated filter, rename 'biquad' to whatever the new filter is, then
	//put this code either within the sample buffer (for smoothly modulating freq or res)
	//or in this 'read the controls' area (for letting you change freq and res with controls)
	//or in 'reset' if the freq and res are absolutely fixed (use GetSampleRate to define freq)
	
	if (type == 1) { //lowpass
		double K = tan(M_PI * biquad[0]);
		double norm = 1.0 / (1.0 + K / biquad[1] + K * K);
		biquad[2] = K * K * norm;
		biquad[3] = 2.0 * biquad[2];
		biquad[4] = biquad[2];
		biquad[5] = 2.0 * (K * K - 1.0) * norm;
		biquad[6] = (1.0 - K / biquad[1] + K * K) * norm;
	}
	
	if (type == 2) { //highpass
		double K = tan(M_PI * biquad[0]);
		double norm = 1.0 / (1.0 + K / biquad[1] + K * K);
		biquad[2] = norm;
		biquad[3] = -2.0 * biquad[2];
		biquad[4] = biquad[2];
		biquad[5] = 2.0 * (K * K - 1.0) * norm;
		biquad[6] = (1.0 - K / biquad[1] + K * K) * norm;
	}
	
	if (type == 3) { //bandpass
		double K = tan(M_PI * biquad[0]);
		double norm = 1.0 / (1.0 + K / biquad[1] + K * K);
		biquad[2] = K / biquad[1] * norm;
		biquad[3] = 0.0; //bandpass can simplify the biquad kernel: leave out this multiply
		biquad[4] = -biquad[2];
		biquad[5] = 2.0 * (K * K - 1.0) * norm;
		biquad[6] = (1.0 - K / biquad[1] + K * K) * norm;
	}
	
	if (type == 4) { //notch
		double K = tan(M_PI * biquad[0]);
		double norm = 1.0 / (1.0 + K / biquad[1] + K * K);
		biquad[2] = (1.0 + K * K) * norm;
		biquad[3] = 2.0 * (K * K - 1) * norm;
		biquad[4] = biquad[2];
		biquad[5] = biquad[3];
		biquad[6] = (1.0 - K / biquad[1] + K * K) * norm;
	}
	
	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;
		double drySampleL = inputSampleL;
		double drySampleR = inputSampleR;
		
		
		inputSampleL = sin(inputSampleL);
		inputSampleR = sin(inputSampleR);
		//encode Console5: good cleanness
		
		/*
		double mid = inputSampleL + inputSampleR;
		double side = inputSampleL - inputSampleR;
		//assign mid and side.Between these sections, you can do mid/side processing
		
		double tempSampleM = (mid * biquad[2]) + biquad[7];
		biquad[7] = (mid * biquad[3]) - (tempSampleM * biquad[5]) + biquad[8];
		biquad[8] = (mid * biquad[4]) - (tempSampleM * biquad[6]);
		mid = tempSampleM; //like mono AU, 7 and 8 store mid channel
		
		double tempSampleS = (side * biquad[2]) + biquad[9];
		biquad[9] = (side * biquad[3]) - (tempSampleS * biquad[5]) + biquad[10];
		biquad[10] = (side * biquad[4]) - (tempSampleS * biquad[6]);
		inputSampleR = tempSampleS; //note: 9 and 10 store the side channel		
		
		inputSampleL = (mid+side)/2.0;
		inputSampleR = (mid-side)/2.0;
		//unassign mid and side
		*/
		
		double tempSampleL = (inputSampleL * biquad[2]) + biquad[7];
		biquad[7] = (inputSampleL * biquad[3]) - (tempSampleL * biquad[5]) + biquad[8];
		biquad[8] = (inputSampleL * biquad[4]) - (tempSampleL * biquad[6]);
		inputSampleL = tempSampleL; //like mono AU, 7 and 8 store L channel

		double tempSampleR = (inputSampleR * biquad[2]) + biquad[9];
		biquad[9] = (inputSampleR * biquad[3]) - (tempSampleR * biquad[5]) + biquad[10];
		biquad[10] = (inputSampleR * biquad[4]) - (tempSampleR * biquad[6]);
		inputSampleR = tempSampleR; //note: 9 and 10 store the R channel
		
		if (inputSampleL > 1.0) inputSampleL = 1.0;
		if (inputSampleL < -1.0) inputSampleL = -1.0;
		if (inputSampleR > 1.0) inputSampleR = 1.0;
		if (inputSampleR < -1.0) inputSampleR = -1.0;
		//without this, you can get a NaN condition where it spits out DC offset at full blast!
		inputSampleL = asin(inputSampleL);
		inputSampleR = asin(inputSampleR);
		//amplitude aspect
		
		if (wet < 1.0) {
			inputSampleL = (inputSampleL*wet) + (drySampleL*(1.0-fabs(wet)));
			inputSampleR = (inputSampleR*wet) + (drySampleR*(1.0-fabs(wet)));
			//inv/dry/wet lets us turn LP into HP and band into notch
		}
		
		//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;
}

