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

#ifndef __DeRez_H
#include "DeRez.h"
#endif

void DeRez::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 targetA = pow(A,3)+0.0005;
	if (targetA > 1.0) targetA = 1.0;
	double soften = (1.0 + targetA)/2;
	double targetB = pow(1.0-B,3) / 3;
	targetA /= overallscale;
	
    while (--sampleFrames >= 0)
    {
		long double inputSampleL = *in1;
		long double inputSampleR = *in2;
		if (inputSampleL<1.2e-38 && -inputSampleL<1.2e-38 && (targetB == 0)) {
			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 && (targetB == 0)) {
			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.
		}
		long double drySampleL = inputSampleL;
		long double drySampleR = inputSampleR;
		
		incrementA = ((incrementA*999.0)+targetA)/1000.0;
		incrementB = ((incrementB*999.0)+targetB)/1000.0;
		//incrementA is the frequency derez
		//incrementB is the bit depth derez
		position += incrementA;
		
		long double outputSampleL = heldSampleL;
		long double outputSampleR = heldSampleR;
		if (position > 1.0)
		{
			position -= 1.0;
			heldSampleL = (lastSampleL * position) + (inputSampleL * (1.0-position));
			outputSampleL = (outputSampleL * (1.0-soften)) + (heldSampleL * soften);
			//softens the edge of the derez
			heldSampleR = (lastSampleR * position) + (inputSampleR * (1.0-position));
			outputSampleR = (outputSampleR * (1.0-soften)) + (heldSampleR * soften);
			//softens the edge of the derez
		}
		inputSampleL = outputSampleL;
		inputSampleR = outputSampleR;
		
		long double offset;
		if (incrementB > 0.0005)
		{
			if (inputSampleL > 0)
			{
				offset = inputSampleL;
				while (offset > 0) {offset -= incrementB;}
				inputSampleL -= offset;
				//it's below 0 so subtracting adds the remainder
			}
			if (inputSampleR > 0)
			{
				offset = inputSampleR;
				while (offset > 0) {offset -= incrementB;}
				inputSampleR -= offset;
				//it's below 0 so subtracting adds the remainder
			}
			
			if (inputSampleL < 0)
			{
				offset = inputSampleL;
				while (offset < 0) {offset += incrementB;}
				inputSampleL -= offset;
				//it's above 0 so subtracting subtracts the remainder
			}
			if (inputSampleR < 0)
			{
				offset = inputSampleR;
				while (offset < 0) {offset += incrementB;}
				inputSampleR -= offset;
				//it's above 0 so subtracting subtracts the remainder
			}
			
			inputSampleL *= (1.0 - incrementB);
			inputSampleR *= (1.0 - incrementB);
		}
		
		lastSampleL = drySampleL;
		lastSampleR = drySampleR;
		
		//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 DeRez::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 targetA = pow(A,3)+0.0005;
	if (targetA > 1.0) targetA = 1.0;
	double soften = (1.0 + targetA)/2;
	double targetB = pow(1.0-B,3) / 3;
	targetA /= overallscale;

    while (--sampleFrames >= 0)
    {
		long double inputSampleL = *in1;
		long double inputSampleR = *in2;
		if (inputSampleL<1.2e-38 && -inputSampleL<1.2e-38 && (targetB == 0)) {
			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 && (targetB == 0)) {
			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.
		}
		long double drySampleL = inputSampleL;
		long double drySampleR = inputSampleR;
		
		incrementA = ((incrementA*999.0)+targetA)/1000.0;
		incrementB = ((incrementB*999.0)+targetB)/1000.0;
		//incrementA is the frequency derez
		//incrementB is the bit depth derez
		position += incrementA;
		
		long double outputSampleL = heldSampleL;
		long double outputSampleR = heldSampleR;
		if (position > 1.0)
		{
			position -= 1.0;
			heldSampleL = (lastSampleL * position) + (inputSampleL * (1.0-position));
			outputSampleL = (outputSampleL * (1.0-soften)) + (heldSampleL * soften);
			//softens the edge of the derez
			heldSampleR = (lastSampleR * position) + (inputSampleR * (1.0-position));
			outputSampleR = (outputSampleR * (1.0-soften)) + (heldSampleR * soften);
			//softens the edge of the derez
		}
		inputSampleL = outputSampleL;
		inputSampleR = outputSampleR;
		
		long double offset;
		if (incrementB > 0.0005)
		{
			if (inputSampleL > 0)
			{
				offset = inputSampleL;
				while (offset > 0) {offset -= incrementB;}
				inputSampleL -= offset;
				//it's below 0 so subtracting adds the remainder
			}
			if (inputSampleR > 0)
			{
				offset = inputSampleR;
				while (offset > 0) {offset -= incrementB;}
				inputSampleR -= offset;
				//it's below 0 so subtracting adds the remainder
			}
			
			if (inputSampleL < 0)
			{
				offset = inputSampleL;
				while (offset < 0) {offset += incrementB;}
				inputSampleL -= offset;
				//it's above 0 so subtracting subtracts the remainder
			}
			if (inputSampleR < 0)
			{
				offset = inputSampleR;
				while (offset < 0) {offset += incrementB;}
				inputSampleR -= offset;
				//it's above 0 so subtracting subtracts the remainder
			}
			
			inputSampleL *= (1.0 - incrementB);
			inputSampleR *= (1.0 - incrementB);
		}
		
		lastSampleL = drySampleL;
		lastSampleR = drySampleR;
		
		//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++;
    }
}