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

#ifndef __StereoFX_H
#include "StereoFX.h"
#endif

void StereoFX::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();
	long double inputSampleL;
	long double inputSampleR;
	long double mid;
	long double side;
	//High Impact section
	double stereowide = A;
	double centersquish = C;
	double density = stereowide * 2.4;
	double sustain = 1.0 - (1.0/(1.0 + (density/7.0)));
	//this way, enhance increases up to 50% and then mid falls off beyond that
	double bridgerectifier;
	double count;
	//Highpass section
	double iirAmount = pow(B,3)/overallscale;
	double tight = -0.33333333333333;
	double offset;
	//we are setting it up so that to either extreme we can get an audible sound,
	//but sort of scaled so small adjustments don't shift the cutoff frequency yet.
	
    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.
		}
		//assign working variables		
		mid = inputSampleL + inputSampleR;
		side = inputSampleL - inputSampleR;
		//assign mid and side. Now, High Impact code
		count = density;
		while (count > 1.0)
		{
			bridgerectifier = fabs(side)*1.57079633;
			if (bridgerectifier > 1.57079633) bridgerectifier = 1.57079633;
			//max value for sine function
			bridgerectifier = sin(bridgerectifier);
			if (side > 0.0) side = bridgerectifier;
			else side = -bridgerectifier;
			count = count - 1.0;
		}
		//we have now accounted for any really high density settings.
		bridgerectifier = fabs(side)*1.57079633;
		if (bridgerectifier > 1.57079633) bridgerectifier = 1.57079633;
		//max value for sine function
		bridgerectifier = sin(bridgerectifier);
		if (side > 0) side = (side*(1-count))+(bridgerectifier*count);
		else side = (side*(1-count))-(bridgerectifier*count);
		//blend according to density control
		//done first density. Next, sustain-reducer
		bridgerectifier = fabs(side)*1.57079633;
		if (bridgerectifier > 1.57079633) bridgerectifier = 1.57079633;
		bridgerectifier = (1-cos(bridgerectifier))*3.141592653589793;
		if (side > 0) side = (side*(1-sustain))+(bridgerectifier*sustain);
		else side = (side*(1-sustain))-(bridgerectifier*sustain);
		//done with High Impact code
		
		//now, Highpass code
		offset = 0.666666666666666 + ((1-fabs(side))*tight);
		if (offset < 0) offset = 0;
		if (offset > 1) offset = 1;
		if (flip)
		{
			iirSampleA = (iirSampleA * (1 - (offset * iirAmount))) + (side * (offset * iirAmount));
			side = side - iirSampleA;
		}
		else
		{
			iirSampleB = (iirSampleB * (1 - (offset * iirAmount))) + (side * (offset * iirAmount));
			side = side - iirSampleB;
		}
		//done with Highpass code
		
		bridgerectifier = fabs(mid)/1.273239544735162;
		if (bridgerectifier > 1.57079633) bridgerectifier = 1.57079633;
		bridgerectifier = sin(bridgerectifier)*1.273239544735162;
		if (mid > 0) mid = (mid*(1-centersquish))+(bridgerectifier*centersquish);
		else mid = (mid*(1-centersquish))-(bridgerectifier*centersquish);
		//done with the mid saturating section.
		
		inputSampleL = (mid+side)/2.0;
		inputSampleR = (mid-side)/2.0;
		
		//stereo 32 bit dither, made small and tidy.
		int expon; frexpf((float)inputSampleL, &expon);
		long double dither = (rand()/(RAND_MAX*7.737125245533627e+25))*pow(2,expon+62);
		inputSampleL += (dither-fpNShapeL); fpNShapeL = dither;
		frexpf((float)inputSampleR, &expon);
		dither = (rand()/(RAND_MAX*7.737125245533627e+25))*pow(2,expon+62);
		inputSampleR += (dither-fpNShapeR); fpNShapeR = dither;
		//end 32 bit dither

		*out1 = inputSampleL;
		*out2 = inputSampleR;

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

void StereoFX::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();
	long double inputSampleL;
	long double inputSampleR;
	long double mid;
	long double side;
	//High Impact section
	double stereowide = A;
	double centersquish = C;
	double density = stereowide * 2.4;
	double sustain = 1.0 - (1.0/(1.0 + (density/7.0)));
	//this way, enhance increases up to 50% and then mid falls off beyond that
	double bridgerectifier;
	double count;
	//Highpass section
	double iirAmount = pow(B,3)/overallscale;
	double tight = -0.33333333333333;
	double offset;
	//we are setting it up so that to either extreme we can get an audible sound,
	//but sort of scaled so small adjustments don't shift the cutoff frequency yet.
	
    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.
		}
		//assign working variables		
		mid = inputSampleL + inputSampleR;
		side = inputSampleL - inputSampleR;
		//assign mid and side. Now, High Impact code
		count = density;
		while (count > 1.0)
		{
			bridgerectifier = fabs(side)*1.57079633;
			if (bridgerectifier > 1.57079633) bridgerectifier = 1.57079633;
			//max value for sine function
			bridgerectifier = sin(bridgerectifier);
			if (side > 0.0) side = bridgerectifier;
			else side = -bridgerectifier;
			count = count - 1.0;
		}
		//we have now accounted for any really high density settings.
		bridgerectifier = fabs(side)*1.57079633;
		if (bridgerectifier > 1.57079633) bridgerectifier = 1.57079633;
		//max value for sine function
		bridgerectifier = sin(bridgerectifier);
		if (side > 0) side = (side*(1-count))+(bridgerectifier*count);
		else side = (side*(1-count))-(bridgerectifier*count);
		//blend according to density control
		//done first density. Next, sustain-reducer
		bridgerectifier = fabs(side)*1.57079633;
		if (bridgerectifier > 1.57079633) bridgerectifier = 1.57079633;
		bridgerectifier = (1-cos(bridgerectifier))*3.141592653589793;
		if (side > 0) side = (side*(1-sustain))+(bridgerectifier*sustain);
		else side = (side*(1-sustain))-(bridgerectifier*sustain);
		//done with High Impact code
		
		//now, Highpass code
		offset = 0.666666666666666 + ((1-fabs(side))*tight);
		if (offset < 0) offset = 0;
		if (offset > 1) offset = 1;
		if (flip)
		{
			iirSampleA = (iirSampleA * (1 - (offset * iirAmount))) + (side * (offset * iirAmount));
			side = side - iirSampleA;
		}
		else
		{
			iirSampleB = (iirSampleB * (1 - (offset * iirAmount))) + (side * (offset * iirAmount));
			side = side - iirSampleB;
		}
		//done with Highpass code
		
		bridgerectifier = fabs(mid)/1.273239544735162;
		if (bridgerectifier > 1.57079633) bridgerectifier = 1.57079633;
		bridgerectifier = sin(bridgerectifier)*1.273239544735162;
		if (mid > 0) mid = (mid*(1-centersquish))+(bridgerectifier*centersquish);
		else mid = (mid*(1-centersquish))-(bridgerectifier*centersquish);
		//done with the mid saturating section.
		
		inputSampleL = (mid+side)/2.0;
		inputSampleR = (mid-side)/2.0;
		
		//stereo 64 bit dither, made small and tidy.
		int expon; frexp((double)inputSampleL, &expon);
		long double dither = (rand()/(RAND_MAX*7.737125245533627e+25))*pow(2,expon+62);
		dither /= 536870912.0; //needs this to scale to 64 bit zone
		inputSampleL += (dither-fpNShapeL); fpNShapeL = dither;
		frexp((double)inputSampleR, &expon);
		dither = (rand()/(RAND_MAX*7.737125245533627e+25))*pow(2,expon+62);
		dither /= 536870912.0; //needs this to scale to 64 bit zone
		inputSampleR += (dither-fpNShapeR); fpNShapeR = dither;
		//end 64 bit dither
		
		*out1 = inputSampleL;
		*out2 = inputSampleR;

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