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

#ifndef __Surge_H
#include "Surge.h"
#endif

void Surge::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 drySampleL;
	long double drySampleR;
	
	double chaseMax = 0.0;
	double intensity = (1.0-(pow((1.0-A),2)))*0.7;
	double attack = ((intensity+0.1)*0.0005)/overallscale;
	double decay = ((intensity+0.001)*0.00005)/overallscale;
	double wet = B;
	double dry = 1.0 - wet;
	double inputSense;
	
    
    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 *= 8.0;
		inputSampleR *= 8.0;
		inputSampleL *= intensity;
		inputSampleR *= intensity;
		
		inputSense = fabs(inputSampleL);
		if (fabs(inputSampleR) > inputSense)
			inputSense = fabs(inputSampleR);
		
		if (chaseMax < inputSense) chaseA += attack;
		if (chaseMax > inputSense) chaseA -= decay;
		
		if (chaseA > decay) chaseA = decay;
		if (chaseA < -attack) chaseA = -attack;
		
		chaseB += (chaseA/overallscale);
		if (chaseB > decay) chaseB = decay;
		if (chaseB < -attack) chaseB = -attack;
		
		chaseC += (chaseB/overallscale);
		if (chaseC > decay) chaseC = decay;
		if (chaseC < -attack) chaseC = -attack;
		
		chaseD += (chaseC/overallscale);
		if (chaseD > 1.0) chaseD = 1.0;
		if (chaseD < 0.0) chaseD = 0.0;
		
		chaseMax = chaseA;
		if (chaseMax < chaseB) chaseMax = chaseB;
		if (chaseMax < chaseC) chaseMax = chaseC;
		if (chaseMax < chaseD) chaseMax = chaseD;
		
		inputSampleL *= chaseMax;
		inputSampleL = drySampleL - (inputSampleL * intensity);
		inputSampleL = (drySampleL * dry) + (inputSampleL * wet);
		
		inputSampleR *= chaseMax;
		inputSampleR = drySampleR - (inputSampleR * intensity);
		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 Surge::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 drySampleL;
	long double drySampleR;
	
	double chaseMax = 0.0;
	double intensity = (1.0-(pow((1.0-A),2)))*0.7;
	double attack = ((intensity+0.1)*0.0005)/overallscale;
	double decay = ((intensity+0.001)*0.00005)/overallscale;
	double wet = B;
	double dry = 1.0 - wet;
	double inputSense;
	
    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 *= 8.0;
		inputSampleR *= 8.0;
		inputSampleL *= intensity;
		inputSampleR *= intensity;
		
		inputSense = fabs(inputSampleL);
		if (fabs(inputSampleR) > inputSense)
			inputSense = fabs(inputSampleR);
		
		if (chaseMax < inputSense) chaseA += attack;
		if (chaseMax > inputSense) chaseA -= decay;
		
		if (chaseA > decay) chaseA = decay;
		if (chaseA < -attack) chaseA = -attack;
		
		chaseB += (chaseA/overallscale);
		if (chaseB > decay) chaseB = decay;
		if (chaseB < -attack) chaseB = -attack;
		
		chaseC += (chaseB/overallscale);
		if (chaseC > decay) chaseC = decay;
		if (chaseC < -attack) chaseC = -attack;
		
		chaseD += (chaseC/overallscale);
		if (chaseD > 1.0) chaseD = 1.0;
		if (chaseD < 0.0) chaseD = 0.0;
		
		chaseMax = chaseA;
		if (chaseMax < chaseB) chaseMax = chaseB;
		if (chaseMax < chaseC) chaseMax = chaseC;
		if (chaseMax < chaseD) chaseMax = chaseD;
		
		inputSampleL *= chaseMax;
		inputSampleL = drySampleL - (inputSampleL * intensity);
		inputSampleL = (drySampleL * dry) + (inputSampleL * wet);
		
		inputSampleR *= chaseMax;
		inputSampleR = drySampleR - (inputSampleR * intensity);
		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++;
    }
}