/* ========================================
 *  Channel4 - Channel4.h
 *  Copyright (c) 2016 airwindows, All rights reserved
 * ======================================== */

#ifndef __Channel4_H
#include "Channel4.h"
#endif

void Channel4::processReplacing(float **inputs, float **outputs, VstInt32 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();
	float fpTemp;
	double fpOld = 0.618033988749894848204586; //golden ratio!
	double fpNew = 1.0 - fpOld;
	
	const double localiirAmount = iirAmount / overallscale;
	const double localthreshold = threshold / overallscale;
	const double density = pow(drive,2); //this doesn't relate to the plugins Density and Drive much
	double clamp;
	long double bridgerectifier;

	long double inputSampleL;
	long double inputSampleR;
	
    while (--sampleFrames >= 0)
    {
		inputSampleL = *in1;
		inputSampleR = *in2;
		if (inputSampleL<1.2e-38 && -inputSampleL<1.2e-38) {
			static int noisesource = 0;
			//this declares a variable before anything else is compiled. It won't keep assigning
			//it to 0 for every sample, it's as if the declaration doesn't exist in this context,
			//but it lets me add this denormalization fix in a single place rather than updating
			//it in three different locations. The variable isn't thread-safe but this is only
			//a random seed and we can share it with whatever.
			noisesource = noisesource % 1700021; noisesource++;
			int residue = noisesource * noisesource;
			residue = residue % 170003; residue *= residue;
			residue = residue % 17011; residue *= residue;
			residue = residue % 1709; residue *= residue;
			residue = residue % 173; residue *= residue;
			residue = residue % 17;
			double applyresidue = residue;
			applyresidue *= 0.00000001;
			applyresidue *= 0.00000001;
			inputSampleL = applyresidue;
		}
		if (inputSampleR<1.2e-38 && -inputSampleR<1.2e-38) {
			static int noisesource = 0;
			noisesource = noisesource % 1700021; noisesource++;
			int residue = noisesource * noisesource;
			residue = residue % 170003; residue *= residue;
			residue = residue % 17011; residue *= residue;
			residue = residue % 1709; residue *= residue;
			residue = residue % 173; residue *= residue;
			residue = residue % 17;
			double applyresidue = residue;
			applyresidue *= 0.00000001;
			applyresidue *= 0.00000001;
			inputSampleR = applyresidue;
			//this denormalization routine produces a white noise at -300 dB which the noise
			//shaping will interact with to produce a bipolar output, but the noise is actually
			//all positive. That should stop any variables from going denormal, and the routine
			//only kicks in if digital black is input. As a final touch, if you save to 24-bit
			//the silence will return to being digital black again.
		}

		if (fpFlip)
		{
			iirSampleLA = (iirSampleLA * (1 - localiirAmount)) + (inputSampleL * localiirAmount);
			inputSampleL = inputSampleL - iirSampleLA;
			iirSampleRA = (iirSampleRA * (1 - localiirAmount)) + (inputSampleR * localiirAmount);
			inputSampleR = inputSampleR - iirSampleRA;
		}
		else
		{
			iirSampleLB = (iirSampleLB * (1 - localiirAmount)) + (inputSampleL * localiirAmount);
			inputSampleL = inputSampleL - iirSampleLB;
			iirSampleRB = (iirSampleRB * (1 - localiirAmount)) + (inputSampleR * localiirAmount);
			inputSampleR = inputSampleR - iirSampleRB;
		}
		//highpass section
		
		bridgerectifier = fabs(inputSampleL)*1.57079633;
		if (bridgerectifier > 1.57079633) bridgerectifier = 1.0;
		else bridgerectifier = sin(bridgerectifier);
		if (inputSampleL > 0) inputSampleL = (inputSampleL*(1-density))+(bridgerectifier*density);
		else inputSampleL = (inputSampleL*(1-density))-(bridgerectifier*density);

		bridgerectifier = fabs(inputSampleR)*1.57079633;
		if (bridgerectifier > 1.57079633) bridgerectifier = 1.0;
		else bridgerectifier = sin(bridgerectifier);
		if (inputSampleR > 0) inputSampleR = (inputSampleR*(1-density))+(bridgerectifier*density);
		else inputSampleR = (inputSampleR*(1-density))-(bridgerectifier*density);
		//drive section

		clamp = inputSampleL - lastSampleL;
		if (clamp > localthreshold)
			inputSampleL = lastSampleL + localthreshold;
		if (-clamp > localthreshold)
			inputSampleL = lastSampleL - localthreshold;
		lastSampleL = inputSampleL;

		clamp = inputSampleR - lastSampleR;
		if (clamp > localthreshold)
			inputSampleR = lastSampleR + localthreshold;
		if (-clamp > localthreshold)
			inputSampleR = lastSampleR - localthreshold;
		lastSampleR = inputSampleR;
		//slew section		
	
		//noise shaping to 32-bit floating point
		if (fpFlip) {
			fpTemp = inputSampleL;
			fpNShapeLA = (fpNShapeLA*fpOld)+((inputSampleL-fpTemp)*fpNew);
			inputSampleL += fpNShapeLA;
			fpTemp = inputSampleR;
			fpNShapeRA = (fpNShapeRA*fpOld)+((inputSampleR-fpTemp)*fpNew);
			inputSampleR += fpNShapeRA;
		}
		else {
			fpTemp = inputSampleL;
			fpNShapeLB = (fpNShapeLB*fpOld)+((inputSampleL-fpTemp)*fpNew);
			inputSampleL += fpNShapeLB;
			fpTemp = inputSampleR;
			fpNShapeRB = (fpNShapeRB*fpOld)+((inputSampleR-fpTemp)*fpNew);
			inputSampleR += fpNShapeRB;
		}
		fpFlip = !fpFlip;
		//end noise shaping on 32 bit output

		*out1 = inputSampleL;
		*out2 = inputSampleR;

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

void Channel4::processDoubleReplacing(double **inputs, double **outputs, VstInt32 sampleFrames) 
{
    double* in1  =  inputs[0];
    double* in2  =  inputs[1];
    double* out1 = outputs[0];
    double* out2 = outputs[1];

	double overallscale = 1.0;
	overallscale /= 44100.0;
	overallscale *= getSampleRate();
	double fpTemp; //this is different from singlereplacing
	double fpOld = 0.618033988749894848204586; //golden ratio!
	double fpNew = 1.0 - fpOld;
	
	const double localiirAmount = iirAmount / overallscale;
	const double localthreshold = threshold / overallscale;
	const double density = pow(drive,2); //this doesn't relate to the plugins Density and Drive much
	double clamp;
	long double bridgerectifier;
	
	long double inputSampleL;
	long double inputSampleR;

    while (--sampleFrames >= 0)
    {
		inputSampleL = *in1;
		inputSampleR = *in2;
		if (inputSampleL<1.2e-38 && -inputSampleL<1.2e-38) {
			static int noisesource = 0;
			//this declares a variable before anything else is compiled. It won't keep assigning
			//it to 0 for every sample, it's as if the declaration doesn't exist in this context,
			//but it lets me add this denormalization fix in a single place rather than updating
			//it in three different locations. The variable isn't thread-safe but this is only
			//a random seed and we can share it with whatever.
			noisesource = noisesource % 1700021; noisesource++;
			int residue = noisesource * noisesource;
			residue = residue % 170003; residue *= residue;
			residue = residue % 17011; residue *= residue;
			residue = residue % 1709; residue *= residue;
			residue = residue % 173; residue *= residue;
			residue = residue % 17;
			double applyresidue = residue;
			applyresidue *= 0.00000001;
			applyresidue *= 0.00000001;
			inputSampleL = applyresidue;
		}
		if (inputSampleR<1.2e-38 && -inputSampleR<1.2e-38) {
			static int noisesource = 0;
			noisesource = noisesource % 1700021; noisesource++;
			int residue = noisesource * noisesource;
			residue = residue % 170003; residue *= residue;
			residue = residue % 17011; residue *= residue;
			residue = residue % 1709; residue *= residue;
			residue = residue % 173; residue *= residue;
			residue = residue % 17;
			double applyresidue = residue;
			applyresidue *= 0.00000001;
			applyresidue *= 0.00000001;
			inputSampleR = applyresidue;
			//this denormalization routine produces a white noise at -300 dB which the noise
			//shaping will interact with to produce a bipolar output, but the noise is actually
			//all positive. That should stop any variables from going denormal, and the routine
			//only kicks in if digital black is input. As a final touch, if you save to 24-bit
			//the silence will return to being digital black again.
		}

		if (fpFlip)
		{
			iirSampleLA = (iirSampleLA * (1 - localiirAmount)) + (inputSampleL * localiirAmount);
			inputSampleL = inputSampleL - iirSampleLA;
			iirSampleRA = (iirSampleRA * (1 - localiirAmount)) + (inputSampleR * localiirAmount);
			inputSampleR = inputSampleR - iirSampleRA;
		}
		else
		{
			iirSampleLB = (iirSampleLB * (1 - localiirAmount)) + (inputSampleL * localiirAmount);
			inputSampleL = inputSampleL - iirSampleLB;
			iirSampleRB = (iirSampleRB * (1 - localiirAmount)) + (inputSampleR * localiirAmount);
			inputSampleR = inputSampleR - iirSampleRB;
		}
		//highpass section
		
		bridgerectifier = fabs(inputSampleL)*1.57079633;
		if (bridgerectifier > 1.57079633) bridgerectifier = 1.0;
		else bridgerectifier = sin(bridgerectifier);
		if (inputSampleL > 0) inputSampleL = (inputSampleL*(1-density))+(bridgerectifier*density);
		else inputSampleL = (inputSampleL*(1-density))-(bridgerectifier*density);
		
		bridgerectifier = fabs(inputSampleR)*1.57079633;
		if (bridgerectifier > 1.57079633) bridgerectifier = 1.0;
		else bridgerectifier = sin(bridgerectifier);
		if (inputSampleR > 0) inputSampleR = (inputSampleR*(1-density))+(bridgerectifier*density);
		else inputSampleR = (inputSampleR*(1-density))-(bridgerectifier*density);
		//drive section
		
		clamp = inputSampleL - lastSampleL;
		if (clamp > localthreshold)
			inputSampleL = lastSampleL + localthreshold;
		if (-clamp > localthreshold)
			inputSampleL = lastSampleL - localthreshold;
		lastSampleL = inputSampleL;
		
		clamp = inputSampleR - lastSampleR;
		if (clamp > localthreshold)
			inputSampleR = lastSampleR + localthreshold;
		if (-clamp > localthreshold)
			inputSampleR = lastSampleR - localthreshold;
		lastSampleR = inputSampleR;
		//slew section		

		//noise shaping to 64-bit floating point
		if (fpFlip) {
			fpTemp = inputSampleL;
			fpNShapeLA = (fpNShapeLA*fpOld)+((inputSampleL-fpTemp)*fpNew);
			inputSampleL += fpNShapeLA;
			fpTemp = inputSampleR;
			fpNShapeRA = (fpNShapeRA*fpOld)+((inputSampleR-fpTemp)*fpNew);
			inputSampleR += fpNShapeRA;
		}
		else {
			fpTemp = inputSampleL;
			fpNShapeLB = (fpNShapeLB*fpOld)+((inputSampleL-fpTemp)*fpNew);
			inputSampleL += fpNShapeLB;
			fpTemp = inputSampleR;
			fpNShapeRB = (fpNShapeRB*fpOld)+((inputSampleR-fpTemp)*fpNew);
			inputSampleR += fpNShapeRB;
		}
		fpFlip = !fpFlip;
		//end noise shaping on 64 bit output

		*out1 = inputSampleL;
		*out2 = inputSampleR;

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