/*
*	File:		Pear.cpp
*	
*	Version:	1.0
* 
*	Created:	6/13/23
*	
*	Copyright:  Copyright © 2023 Airwindows, Airwindows uses the MIT license
* 
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/*=============================================================================
	Pear.cpp
	
=============================================================================*/
#include "Pear.h"


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

COMPONENT_ENTRY(Pear)


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


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



//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
//	Pear::GetParameterInfo
//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
ComponentResult			Pear::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;
            case kParam_Three:
                AUBase::FillInParameterName (outParameterInfo, kParameterThreeName, false);
                outParameterInfo.unit = kAudioUnitParameterUnit_Generic;
                outParameterInfo.minValue = 0.0;
                outParameterInfo.maxValue = 1.0;
                outParameterInfo.defaultValue = kDefaultValue_ParamThree;
                break;
           default:
                result = kAudioUnitErr_InvalidParameter;
                break;
            }
	} else {
        result = kAudioUnitErr_InvalidParameter;
    }
    


	return result;
}

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

	return 1;
}

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

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

#pragma mark ____PearEffectKernel



//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
//	Pear::PearKernel::Reset()
//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
ComponentResult		Pear::Reset(AudioUnitScope inScope, AudioUnitElement inElement)
{
	for (int x = 0; x < pear_total; x++) pear[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;
}

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
//	Pear::ProcessBufferLists
//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
OSStatus		Pear::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 > 3) cycleEnd = 3;
	cycleEnd--; //this is going to be 0 for 44.1 or 48k, 1 for 88.2 or 96k, 2 for 176 or 192k.
	//DIFFERENT! Offsetting the bt shift
	
	int bitshiftFreq = (10-(GetParameter( kParam_One )*10.0))+cycleEnd;
	double freq = 1.0;
	switch (bitshiftFreq)
	{
		case 16: freq = 0.0000152587890625; break;
		case 15: freq = 0.000030517578125; break;
		case 14: freq = 0.00006103515625; break;
		case 13: freq = 0.0001220703125; break;
		case 12: freq = 0.000244140625; break;
		case 11: freq = 0.00048828125; break;
		case 10: freq = 0.0009765625; break;
		case 9: freq = 0.001953125; break;
		case 8: freq = 0.00390625; break;
		case 7: freq = 0.0078125; break;
		case 6: freq = 0.015625; break;
		case 5: freq = 0.03125; break;
		case 4: freq = 0.0625; break;
		case 3: freq = 0.125; break;
		case 2: freq = 0.25; break;
		case 1: freq = 0.5; break;
		case 0: freq = 1.0; break;
	}
	double maxPoles = GetParameter( kParam_Two )*pear_total;
	double wet = (GetParameter( kParam_Three )*2.0)-1.0; //inv-dry-wet for highpass
	double dry = 2.0-(GetParameter( kParam_Three )*2.0);
	if (dry > 1.0) dry = 1.0; //full dry for use with inv, to 0.0 at full wet
	
	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;
		
		//Pear is a variation on a Holt filter, made to act like my biquad filters:
		//its variables (L and R prevSample and prevSlew) contained in arrays for easier handling.
		//On top of that, the array is used to facilitate use of the filter in a stack which will
		//sharpen its very weak frequency response performance (3dB/oct per pole) and allow it to run
		//in a loop. Many earlier Airwindows filters did this 'unrolled', often with variables given
		//lettered suffixes like iirA through iirZ. The use of an array will make this a lot tidier.
		
		for (int x = 0; x < maxPoles; x += 4) {
			double slew = ((inputSampleL - pear[x]) + pear[x+1])*freq*0.5;
			pear[x] = inputSampleL = (freq * inputSampleL) + ((1.0-freq) * (pear[x] + pear[x+1]));
			pear[x+1] = slew;
			slew = ((inputSampleR - pear[x+2]) + pear[x+3])*freq*0.5;
			pear[x+2] = inputSampleR = (freq * inputSampleR) + ((1.0-freq) * (pear[x+2] + pear[x+3]));
			pear[x+3] = slew;
		}
		
		inputSampleL *= wet;
		inputSampleR *= wet;
		drySampleL *= dry;
		drySampleR *= dry;
		inputSampleL += drySampleL;
		inputSampleR += drySampleR;

		//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;
}

