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

#ifndef __Distance_H
#include "Distance.h"
#endif

void Distance::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();
	
	double softslew = (pow(A*2.0,3.0)*12.0)+0.6;
	softslew *= overallscale;
	double filtercorrect = softslew / 2.0;
	double thirdfilter = softslew / 3.0;
	double levelcorrect = 1.0 + (softslew / 6.0);
	double postfilter;
	double wet = B;
	double dry = 1.0-wet;
	double bridgerectifier;	
	
	long double inputSampleL;
	long double inputSampleR;
	long double drySampleL;
	long double drySampleR;
	    
    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.
		}
		drySampleL = inputSampleL;
		drySampleR = inputSampleR;
		
		inputSampleL *= softslew;
		lastclampL = clampL;
		clampL = inputSampleL - lastL;
		postfilter = changeL = fabs(clampL - lastclampL);
		postfilter += filtercorrect;
		if (changeL > 1.5707963267949) changeL = 1.5707963267949;
		bridgerectifier = (1.0-sin(changeL));
		if (bridgerectifier < 0.0) bridgerectifier = 0.0;
		inputSampleL = lastL + (clampL * bridgerectifier);
		lastL = inputSampleL;
		inputSampleL /= softslew;
		inputSampleL += (thirdresultL * thirdfilter);
		inputSampleL /= (thirdfilter + 1.0);
		inputSampleL += (prevresultL * postfilter);
		inputSampleL /= (postfilter + 1.0);
		//do an IIR like thing to further squish superdistant stuff
		thirdresultL = prevresultL;
		prevresultL = inputSampleL;
		inputSampleL *= levelcorrect;
		
		inputSampleR *= softslew;
		lastclampR = clampR;
		clampR = inputSampleR - lastR;
		postfilter = changeR = fabs(clampR - lastclampR);
		postfilter += filtercorrect;
		if (changeR > 1.5707963267949) changeR = 1.5707963267949;
		bridgerectifier = (1.0-sin(changeR));
		if (bridgerectifier < 0.0) bridgerectifier = 0.0;
		inputSampleR = lastR + (clampR * bridgerectifier);
		lastR = inputSampleR;
		inputSampleR /= softslew;
		inputSampleR += (thirdresultR * thirdfilter);
		inputSampleR /= (thirdfilter + 1.0);
		inputSampleR += (prevresultR * postfilter);
		inputSampleR /= (postfilter + 1.0);
		//do an IIR like thing to further squish superdistant stuff
		thirdresultR = prevresultR;
		prevresultR = inputSampleR;
		inputSampleR *= levelcorrect;
		
		if (wet < 1.0) {
			inputSampleL = (drySampleL * dry)+(inputSampleL*wet);
			inputSampleR = (drySampleR * dry)+(inputSampleR*wet);
		}
		
		//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 Distance::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 softslew = (pow(A*2.0,3.0)*12.0)+0.6;
	softslew *= overallscale;
	double filtercorrect = softslew / 2.0;
	double thirdfilter = softslew / 3.0;
	double levelcorrect = 1.0 + (softslew / 6.0);
	double postfilter;
	double wet = B;
	double dry = 1.0-wet;
	double bridgerectifier;	
		
	long double inputSampleL;
	long double inputSampleR;
	long double drySampleL;
	long double drySampleR;

    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.
		}
		drySampleL = inputSampleL;
		drySampleR = inputSampleR;

		inputSampleL *= softslew;
		lastclampL = clampL;
		clampL = inputSampleL - lastL;
		postfilter = changeL = fabs(clampL - lastclampL);
		postfilter += filtercorrect;
		if (changeL > 1.5707963267949) changeL = 1.5707963267949;
		bridgerectifier = (1.0-sin(changeL));
		if (bridgerectifier < 0.0) bridgerectifier = 0.0;
		inputSampleL = lastL + (clampL * bridgerectifier);
		lastL = inputSampleL;
		inputSampleL /= softslew;
		inputSampleL += (thirdresultL * thirdfilter);
		inputSampleL /= (thirdfilter + 1.0);
		inputSampleL += (prevresultL * postfilter);
		inputSampleL /= (postfilter + 1.0);
		//do an IIR like thing to further squish superdistant stuff
		thirdresultL = prevresultL;
		prevresultL = inputSampleL;
		inputSampleL *= levelcorrect;
		
		inputSampleR *= softslew;
		lastclampR = clampR;
		clampR = inputSampleR - lastR;
		postfilter = changeR = fabs(clampR - lastclampR);
		postfilter += filtercorrect;
		if (changeR > 1.5707963267949) changeR = 1.5707963267949;
		bridgerectifier = (1.0-sin(changeR));
		if (bridgerectifier < 0.0) bridgerectifier = 0.0;
		inputSampleR = lastR + (clampR * bridgerectifier);
		lastR = inputSampleR;
		inputSampleR /= softslew;
		inputSampleR += (thirdresultR * thirdfilter);
		inputSampleR /= (thirdfilter + 1.0);
		inputSampleR += (prevresultR * postfilter);
		inputSampleR /= (postfilter + 1.0);
		//do an IIR like thing to further squish superdistant stuff
		thirdresultR = prevresultR;
		prevresultR = inputSampleR;
		inputSampleR *= levelcorrect;
		
		if (wet < 1.0) {
			inputSampleL = (drySampleL * dry)+(inputSampleL*wet);
			inputSampleR = (drySampleR * dry)+(inputSampleR*wet);
		}
		
		//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++;
    }
}