/*
*	File:		PaulDither.cpp
*	
*	Version:	1.0
* 
*	Created:	11/17/16
*	
*	Copyright:  Copyright © 2016 Airwindows, Airwindows uses the MIT license
* 
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/*=============================================================================
	PaulDither.cpp
	
=============================================================================*/
#include "PaulDither.h"


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

COMPONENT_ENTRY(PaulDither)


//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
//	PaulDither::PaulDither
//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PaulDither::PaulDither(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
	
}


//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
//	PaulDither::GetParameterValueStrings
//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
ComponentResult			PaulDither::GetParameterValueStrings(AudioUnitScope		inScope,
                                                                AudioUnitParameterID	inParameterID,
                                                                CFArrayRef *		outStrings)
{
	if ((inScope == kAudioUnitScope_Global) && (inParameterID == kParam_One)) //ID must be actual name of parameter identifier, not number
	{
		if (outStrings == NULL) return noErr;
		CFStringRef strings [] =
		{
			kMenuItem_CD,
			kMenuItem_HD,
		};
		*outStrings = CFArrayCreate (
									 NULL,
									 (const void **) strings,
									 (sizeof (strings) / sizeof (strings [0])),
									 NULL
									 );
		return noErr;
	}
    return kAudioUnitErr_InvalidProperty;
}



//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
//	PaulDither::GetParameterInfo
//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
ComponentResult			PaulDither::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 = kCD;
                outParameterInfo.maxValue = kHD;
                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;
}

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

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

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

#pragma mark ____PaulDitherEffectKernel



//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
//	PaulDither::PaulDitherKernel::Reset()
//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
void		PaulDither::PaulDitherKernel::Reset()
{
	previousDither = 0.0;
	fpd = 1.0; while (fpd < 16386) fpd = rand()*UINT32_MAX;
}

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
//	PaulDither::PaulDitherKernel::Process
//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
void		PaulDither::PaulDitherKernel::Process(	const Float32 	*inSourceP,
                                                    Float32		 	*inDestP,
                                                    UInt32 			inFramesToProcess,
                                                    UInt32			inNumChannels, 
                                                    bool			&ioSilence )
{
	UInt32 nSampleFrames = inFramesToProcess;
	const Float32 *sourceP = inSourceP;
	Float32 *destP = inDestP;
	
	double inputSample;
	Float64 currentDither;
	
	bool highres = false;
	if (GetParameter( kParam_One ) == 1) highres = true;
	Float32 scaleFactor;
	if (highres) scaleFactor = 8388608.0;
	else scaleFactor = 32768.0;
	Float32 derez = GetParameter( kParam_Two );
	if (derez > 0.0) scaleFactor *= pow(1.0-derez,6);
	if (scaleFactor < 0.0001) scaleFactor = 0.0001;
	Float32 outScale = scaleFactor;
	if (outScale < 8.0) outScale = 8.0;
	
	while (nSampleFrames-- > 0) {
		inputSample = *sourceP;
		if (fabs(inputSample)<1.18e-23) inputSample = fpd * 1.18e-17;
		
		
		inputSample *= scaleFactor;
		//0-1 is now one bit, now we dither
		
		currentDither = (double(fpd)/UINT32_MAX);
		inputSample += currentDither;
		inputSample -= previousDither;
		inputSample = floor(inputSample);
		previousDither = currentDither;
		
		//Paul Frindle: It's true that the dither itself can sound different 
		//if it's given a different freq response and you get to hear it. 
		//The one we use most is triangular single pole high pass dither. 
		//It not freq bent enough sound odd, but is slightly less audible than 
		//flat dither. It can also be easily made by taking one sample of dither 
		//away from the previous one - this gives you the triangular PDF and the 
		//filtering in one go :-)
		
		
		inputSample /= outScale;

		fpd ^= fpd << 13; fpd ^= fpd >> 17; fpd ^= fpd << 5;
		//pseudorandom number updater
		
		*destP = inputSample;
		sourceP += inNumChannels; destP += inNumChannels;
	}
}

