/* ========================================
 *  UnBox - UnBox.h
 *  Copyright (c) 2016 airwindows, Airwindows uses the MIT license
 * ======================================== */

#include "UnBox.h"

#ifdef SHR3D_SFX_CORE_AIRWINDOWS

namespace airwinconsolidated::UnBox {

void UnBox::processBlock(float **inputs, float **outputs, int sampleFrames) 
{
    float* in1  =  inputs[0];
    float* in2  =  inputs[1];
    float* out1 = outputs[0];
    float* out2 = outputs[1];

	double overallscale = 1.0;
	overallscale /= 44100.0;
	overallscale *= getSampleRate();

	double input = A*2.0;
	double unbox = B+1.0;
	unbox *= unbox; //let's get some more gain into this
	double iirAmount = (unbox*0.00052)/overallscale;
	double output = C*2.0;
	
	double treble = unbox; //averaging taps 1-4
	double gain = treble;
	if (gain > 1.0) {e[0] = 1.0; gain -= 1.0;} else {e[0] = gain; gain = 0.0;}
	if (gain > 1.0) {e[1] = 1.0; gain -= 1.0;} else {e[1] = gain; gain = 0.0;}
	if (gain > 1.0) {e[2] = 1.0; gain -= 1.0;} else {e[2] = gain; gain = 0.0;}
	if (gain > 1.0) {e[3] = 1.0; gain -= 1.0;} else {e[3] = gain; gain = 0.0;}
	if (gain > 1.0) {e[4] = 1.0; gain -= 1.0;} else {e[4] = gain; gain = 0.0;}
	//there, now we have a neat little moving average with remainders
	if (treble < 1.0) treble = 1.0;
	e[0] /= treble;
	e[1] /= treble;
	e[2] /= treble;
	e[3] /= treble;
	e[4] /= treble;
	//and now it's neatly scaled, too
	
	treble = unbox*2.0; //averaging taps 1-8
	gain = treble;
	if (gain > 1.0) {f[0] = 1.0; gain -= 1.0;} else {f[0] = gain; gain = 0.0;}
	if (gain > 1.0) {f[1] = 1.0; gain -= 1.0;} else {f[1] = gain; gain = 0.0;}
	if (gain > 1.0) {f[2] = 1.0; gain -= 1.0;} else {f[2] = gain; gain = 0.0;}
	if (gain > 1.0) {f[3] = 1.0; gain -= 1.0;} else {f[3] = gain; gain = 0.0;}
	if (gain > 1.0) {f[4] = 1.0; gain -= 1.0;} else {f[4] = gain; gain = 0.0;}
	if (gain > 1.0) {f[5] = 1.0; gain -= 1.0;} else {f[5] = gain; gain = 0.0;}
	if (gain > 1.0) {f[6] = 1.0; gain -= 1.0;} else {f[6] = gain; gain = 0.0;}
	if (gain > 1.0) {f[7] = 1.0; gain -= 1.0;} else {f[7] = gain; gain = 0.0;}
	if (gain > 1.0) {f[8] = 1.0; gain -= 1.0;} else {f[8] = gain; gain = 0.0;}
	if (gain > 1.0) {f[9] = 1.0; gain -= 1.0;} else {f[9] = gain; gain = 0.0;}
	//there, now we have a neat little moving average with remainders
	if (treble < 1.0) treble = 1.0;
	f[0] /= treble;
	f[1] /= treble;
	f[2] /= treble;
	f[3] /= treble;
	f[4] /= treble;
	f[5] /= treble;
	f[6] /= treble;
	f[7] /= treble;
	f[8] /= treble;
	f[9] /= treble;
	//and now it's neatly scaled, too
    
    while (--sampleFrames >= 0)
    {
		double inputSampleL = *in1;
		double inputSampleR = *in2;

		if (input != 1.0) {inputSampleL *= input; inputSampleR *= input;}

		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;
		
		aL[4] = aL[3]; aL[3] = aL[2]; aL[2] = aL[1];
		aL[1] = aL[0]; aL[0] = inputSampleL;
		inputSampleL *= e[0];
		inputSampleL += (aL[1] * e[1]);
		inputSampleL += (aL[2] * e[2]);
		inputSampleL += (aL[3] * e[3]);
		inputSampleL += (aL[4] * e[4]);
		//this is now an average of inputSampleL

		aR[4] = aR[3]; aR[3] = aR[2]; aR[2] = aR[1];
		aR[1] = aR[0]; aR[0] = inputSampleR;
		inputSampleR *= e[0];
		inputSampleR += (aR[1] * e[1]);
		inputSampleR += (aR[2] * e[2]);
		inputSampleR += (aR[3] * e[3]);
		inputSampleR += (aR[4] * e[4]);
		//this is now an average of inputSampleR
		
		bL[4] = bL[3]; bL[3] = bL[2]; bL[2] = bL[1];
		bL[1] = bL[0]; bL[0] = inputSampleL;
		inputSampleL *= e[0];
		inputSampleL += (bL[1] * e[1]);
		inputSampleL += (bL[2] * e[2]);
		inputSampleL += (bL[3] * e[3]);
		inputSampleL += (bL[4] * e[4]);
		//this is now an average of an average of inputSampleL. Two poles
		
		bR[4] = bR[3]; bR[3] = bR[2]; bR[2] = bR[1];
		bR[1] = bR[0]; bR[0] = inputSampleR;
		inputSampleR *= e[0];
		inputSampleR += (bR[1] * e[1]);
		inputSampleR += (bR[2] * e[2]);
		inputSampleR += (bR[3] * e[3]);
		inputSampleR += (bR[4] * e[4]);
		//this is now an average of an average of inputSampleR. Two poles
		
		inputSampleL *= unbox;
		inputSampleR *= unbox;
		//clip to 1.2533141373155 to reach maximum output
		if (inputSampleL > 1.2533141373155) inputSampleL = 1.2533141373155;
		if (inputSampleL < -1.2533141373155) inputSampleL = -1.2533141373155;
		inputSampleL = sin(inputSampleL * fabs(inputSampleL)) / ((fabs(inputSampleL) == 0.0) ?1:fabs(inputSampleL));
		
		if (inputSampleR > 1.2533141373155) inputSampleR = 1.2533141373155;
		if (inputSampleR < -1.2533141373155) inputSampleR = -1.2533141373155;
		inputSampleR = sin(inputSampleR * fabs(inputSampleR)) / ((fabs(inputSampleR) == 0.0) ?1:fabs(inputSampleR));
		
		inputSampleL /= unbox;	
		inputSampleR /= unbox;	
		//now we have a distorted inputSample at the correct volume relative to drySample
		
		double accumulatorSampleL = (drySampleL - inputSampleL);
		cL[9] = cL[8]; cL[8] = cL[7]; cL[7] = cL[6]; cL[6] = cL[5];
		cL[5] = cL[4]; cL[4] = cL[3]; cL[3] = cL[2]; cL[2] = cL[1];
		cL[1] = cL[0]; cL[0] = accumulatorSampleL;
		accumulatorSampleL *= f[0];
		accumulatorSampleL += (cL[1] * f[1]);
		accumulatorSampleL += (cL[2] * f[2]);
		accumulatorSampleL += (cL[3] * f[3]);
		accumulatorSampleL += (cL[4] * f[4]);
		accumulatorSampleL += (cL[5] * f[5]);
		accumulatorSampleL += (cL[6] * f[6]);
		accumulatorSampleL += (cL[7] * f[7]);
		accumulatorSampleL += (cL[8] * f[8]);
		accumulatorSampleL += (cL[9] * f[9]);
		//this is now an average of all the recent variances from dry
		
		double accumulatorSampleR = (drySampleR - inputSampleR);
		cR[9] = cR[8]; cR[8] = cR[7]; cR[7] = cR[6]; cR[6] = cR[5];
		cR[5] = cR[4]; cR[4] = cR[3]; cR[3] = cR[2]; cR[2] = cR[1];
		cR[1] = cR[0]; cR[0] = accumulatorSampleR;
		accumulatorSampleR *= f[0];
		accumulatorSampleR += (cR[1] * f[1]);
		accumulatorSampleR += (cR[2] * f[2]);
		accumulatorSampleR += (cR[3] * f[3]);
		accumulatorSampleR += (cR[4] * f[4]);
		accumulatorSampleR += (cR[5] * f[5]);
		accumulatorSampleR += (cR[6] * f[6]);
		accumulatorSampleR += (cR[7] * f[7]);
		accumulatorSampleR += (cR[8] * f[8]);
		accumulatorSampleR += (cR[9] * f[9]);
		//this is now an average of all the recent variances from dry
		
		iirSampleAL = (iirSampleAL * (1 - iirAmount)) + (accumulatorSampleL * iirAmount);
		accumulatorSampleL -= iirSampleAL;
		//two poles of IIR

		iirSampleAR = (iirSampleAR * (1 - iirAmount)) + (accumulatorSampleR * iirAmount);
		accumulatorSampleR -= iirSampleAR;
		//two poles of IIR

		iirSampleBL = (iirSampleBL * (1 - iirAmount)) + (accumulatorSampleL * iirAmount);
		accumulatorSampleL -= iirSampleBL;
		//highpass section

		iirSampleBR = (iirSampleBR * (1 - iirAmount)) + (accumulatorSampleR * iirAmount);
		accumulatorSampleR -= iirSampleBR;
		//highpass section
		//this is now a highpassed average of all the recent variances from dry
		
		inputSampleL = drySampleL - accumulatorSampleL;
		inputSampleR = drySampleR - accumulatorSampleR;
		//we apply it as one operation, to get the result.
		
		if (output != 1.0) {inputSampleL *= output; inputSampleR *= output;}
		
		//begin 32 bit stereo floating point dither
		int expon; frexpf((float)inputSampleL, &expon);
		fpdL ^= fpdL << 13; fpdL ^= fpdL >> 17; fpdL ^= fpdL << 5;
		inputSampleL += double((double(fpdL)-uint32_t(0x7fffffff)) * 5.5e-36l * pow(2.0,expon+62.0));
		frexpf((float)inputSampleR, &expon);
		fpdR ^= fpdR << 13; fpdR ^= fpdR >> 17; fpdR ^= fpdR << 5;
		inputSampleR += double((double(fpdR)-uint32_t(0x7fffffff)) * 5.5e-36l * pow(2.0,expon+62.0));
		//end 32 bit stereo floating point dither
		
		*out1 = float(inputSampleL);
		*out2 = float(inputSampleR);

		in1++;
		in2++;
		out1++;
		out2++;
    }
}

} // end namespace

#endif // SHR3D_SFX_CORE_AIRWINDOWS
