/*
*	File:		VariMu.cpp
*	
*	Version:	1.0
* 
*	Created:	10/2/10
*	
*	Copyright:  Copyright © 2010 Airwindows, Airwindows uses the MIT license
* 
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/*=============================================================================
	VariMu.h
	
=============================================================================*/
#include "VariMu.h"


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

COMPONENT_ENTRY(VariMu)


//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
//	VariMu::VariMu
//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
VariMu::VariMu(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
	
}


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



//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
//	VariMu::GetParameterInfo
//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
ComponentResult		VariMu::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;
            case kParam_Four:
                AUBase::FillInParameterName (outParameterInfo, kParameterFourName, false);
                outParameterInfo.unit = kAudioUnitParameterUnit_Generic;
                outParameterInfo.minValue = 0.0;
                outParameterInfo.maxValue = 1.0;
                outParameterInfo.defaultValue = kDefaultValue_ParamFour;
                break;
			default:
                result = kAudioUnitErr_InvalidParameter;
                break;
            }
	} else {
        result = kAudioUnitErr_InvalidParameter;
    }
    


	return result;
}

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

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

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

#pragma mark ____VariMuEffectKernel


//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
//	VariMu::VariMuKernel::Reset()
//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
void		VariMu::VariMuKernel::Reset()
{
	muSpeedA = 10000;
	muSpeedB = 10000;
	muCoefficientA = 1;
	muCoefficientB = 1;
	muVary = 1;
	flip = false;
	previous = 0.0;
	fpd = 1.0; while (fpd < 16386) fpd = rand()*UINT32_MAX;
}

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
//	VariMu::VariMuKernel::Process
//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
void		VariMu::VariMuKernel::Process(	const Float32 	*inSourceP,
                                                    Float32		 	*inDestP,
                                                    UInt32 			inFramesToProcess,
                                                    UInt32			inNumChannels,
                                                    bool			&ioSilence )
{
	UInt32 nSampleFrames = inFramesToProcess;
	const Float32 *sourceP = inSourceP;
	Float32 *destP = inDestP;
	Float64 overallscale = 2.0;
	overallscale /= 44100.0;
	overallscale *= GetSampleRate();
	Float64 threshold = 1.001 - (1.0-pow(1.0-GetParameter( kParam_One ),3));
	Float64 muMakeupGain = sqrt(1.0 / threshold);
	muMakeupGain = (muMakeupGain + sqrt(muMakeupGain))/2.0;
	muMakeupGain = sqrt(muMakeupGain);
	Float64 outGain = sqrt(muMakeupGain);
	//gain settings around threshold
	Float64 release = pow((1.15-GetParameter( kParam_Two )),5)*32768.0;
	release /= overallscale;
	Float64 fastest = sqrt(release);
	//speed settings around release
	Float64 coefficient;
	Float64 output = outGain * GetParameter( kParam_Three );
	Float64 wet = GetParameter( kParam_Four );
	double squaredSample;

	// µ µ µ µ µ µ µ µ µ µ µ µ is the kitten song o/~
	
	while (nSampleFrames-- > 0) {
		double inputSample = *sourceP;
		if (fabs(inputSample)<1.18e-23) inputSample = fpd * 1.18e-17;
		double drySample = inputSample;
		
		if (fabs(inputSample) > fabs(previous)) squaredSample = previous * previous;
		else squaredSample = inputSample * inputSample;
		previous = inputSample;
		inputSample *= muMakeupGain;
		
		if (flip)
			{
				if (fabs(squaredSample) > threshold)
					{
						muVary = threshold / fabs(squaredSample);
						muAttack = sqrt(fabs(muSpeedA));
						muCoefficientA = muCoefficientA * (muAttack-1.0);
						if (muVary < threshold)
							{
								muCoefficientA = muCoefficientA + threshold;
							}
						else
							{
								muCoefficientA = muCoefficientA + muVary;
							}
						muCoefficientA = muCoefficientA / muAttack;
					}
				else
					{
						muCoefficientA = muCoefficientA * ((muSpeedA * muSpeedA)-1.0);
						muCoefficientA = muCoefficientA + 1.0;
						muCoefficientA = muCoefficientA / (muSpeedA * muSpeedA);
					}
				muNewSpeed = muSpeedA * (muSpeedA-1);
				muNewSpeed = muNewSpeed + fabs(squaredSample*release)+fastest;
				muSpeedA = muNewSpeed / muSpeedA;
			}
		else
			{
				if (fabs(squaredSample) > threshold)
					{
						muVary = threshold / fabs(squaredSample);
						muAttack = sqrt(fabs(muSpeedB));
						muCoefficientB = muCoefficientB * (muAttack-1);
						if (muVary < threshold)
							{
								muCoefficientB = muCoefficientB + threshold;
							}
						else
							{
								muCoefficientB = muCoefficientB + muVary;
							}
						muCoefficientB = muCoefficientB / muAttack;
					}
				else
					{
						muCoefficientB = muCoefficientB * ((muSpeedB * muSpeedB)-1.0);
						muCoefficientB = muCoefficientB + 1.0;
						muCoefficientB = muCoefficientB / (muSpeedB * muSpeedB);
					}
				muNewSpeed = muSpeedB * (muSpeedB-1);
				muNewSpeed = muNewSpeed + fabs(squaredSample*release)+fastest;
				muSpeedB = muNewSpeed / muSpeedB;
			}
		//got coefficients, adjusted speeds

		if (flip)
			{
			coefficient = (muCoefficientA + pow(muCoefficientA,2))/2.0;
			inputSample *= coefficient;
			}
		else
			{
			coefficient = (muCoefficientB + pow(muCoefficientB,2))/2.0;
			inputSample *= coefficient;
			}
		//applied compression with vari-vari-µ-µ-µ-µ-µ-µ-is-the-kitten-song o/~
		//applied gain correction to control output level- tends to constrain sound rather than inflate it
		flip = !flip;		

		if (output < 1.0) {
			inputSample *= output;
		}
		if (wet < 1.0) {
			inputSample = (drySample * (1.0-wet)) + (inputSample * wet);
		}
		//nice little output stage template: if we have another scale of floating point
		//number, we really don't want to meaninglessly multiply that by 1.0.
		
		//begin 32 bit floating point dither
		int expon; frexpf((float)inputSample, &expon);
		fpd ^= fpd << 13; fpd ^= fpd >> 17; fpd ^= fpd << 5;
		inputSample += ((double(fpd)-uint32_t(0x7fffffff)) * 5.5e-36l * pow(2,expon+62));
		//end 32 bit floating point dither
		
		*destP = inputSample;
		
		sourceP += inNumChannels; destP += inNumChannels;
	}
}

