/*
*	File:		PurestFade.cpp
*	
*	Version:	1.0
* 
*	Created:	5/2/20
*	
*	Copyright:  Copyright © 2020 Airwindows, Airwindows uses the MIT license
* 
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/*=============================================================================
	PurestFade.cpp
	
=============================================================================*/
#include "PurestFade.h"


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

COMPONENT_ENTRY(PurestFade)


//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
//	PurestFade::PurestFade
//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PurestFade::PurestFade(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
	
}


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



//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
//	PurestFade::GetParameterInfo
//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
ComponentResult			PurestFade::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_Decibels;
                outParameterInfo.minValue = -40.0;
                outParameterInfo.maxValue = 40.0;
                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;
}

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

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

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

#pragma mark ____PurestFadeEffectKernel



//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
//	PurestFade::PurestFadeKernel::Reset()
//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
void		PurestFade::PurestFadeKernel::Reset()
{
	gainchase = -90.0;
	settingchase = -90.0;
	gainBchase = -90.0;
	chasespeed = 350.0;
	fpd = 1.0; while (fpd < 16386) fpd = rand()*UINT32_MAX;
}

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
//	PurestFade::PurestFadeKernel::Process
//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
void		PurestFade::PurestFadeKernel::Process(	const Float32 	*inSourceP,
                                                    Float32		 	*inDestP,
                                                    UInt32 			inFramesToProcess,
                                                    UInt32			inNumChannels, 
                                                    bool			&ioSilence )
{
	UInt32 nSampleFrames = inFramesToProcess;
	const Float32 *sourceP = inSourceP;
	Float32 *destP = inDestP;
	
	Float64 inputgain = GetParameter( kParam_One );
	
	if (settingchase != inputgain) {
		chasespeed *= 2.0;
		settingchase = inputgain;
		//increment the slowness for each fader movement
		//continuous alteration makes it react smoother
		//sudden jump to setting, not so much
	}
	if (chasespeed > 2500.0) chasespeed = 2500.0;
	//bail out if it's too extreme
	if (gainchase < -60.0) {
		gainchase = pow(10.0,inputgain/20.0);
		//shouldn't even be a negative number
		//this is about starting at whatever's set, when
		//plugin is instantiated.
		//Otherwise it's the target, in dB.
	}
	double targetgain;	
	//done with top controller
	
	double targetBgain = GetParameter( kParam_Two );
	if (gainBchase < 0.0) gainBchase = targetBgain;
	//this one is not a dB value, but straight multiplication
	//done with slow fade controller
	
	double fadeSpeed = targetBgain;
	if (fadeSpeed < 0.0027) fadeSpeed = 0.0027; //minimum fade speed
	fadeSpeed = ((GetSampleRate()*0.004) / fadeSpeed);
	//this will tend to be much slower than PurestGain, and also adapt to sample rates
	
	double outputgain;
	
	double inputSample;
	
	while (nSampleFrames-- > 0) {
		inputSample = *sourceP;
		if (fabs(inputSample)<1.18e-23) inputSample = fpd * 1.18e-17;
		
		targetgain = pow(10.0,settingchase/20.0);
		//now we have the target in our temp variable
		
		chasespeed *= 0.9999;
		chasespeed -= 0.01;
		if (chasespeed < 350.0) chasespeed = 350.0;
		//we have our chase speed compensated for recent fader activity
		
		gainchase = (((gainchase*chasespeed)+targetgain)/(chasespeed+1.0));
		//gainchase is chasing the target, as a simple multiply gain factor
		
		gainBchase = (((gainBchase*fadeSpeed)+targetBgain)/(fadeSpeed+1.0));
		//gainchase is chasing the target, as a simple multiply gain factor
		
		outputgain = gainchase * gainBchase;
		//directly multiply the dB gain by the straight multiply gain
		
		if (1.0 == outputgain) *destP = *sourceP;
		else
		{
			inputSample *= outputgain;
			
			//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;
	}
}

