path: root/plugins/MacVST/SlewOnly/source/SlewOnlyProc.cpp

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

#ifndef __SlewOnly_H
#include "SlewOnly.h"
#endif

void SlewOnly::processReplacing(float **inputs, float **outputs, VstInt32 sampleFrames) 
{
    float* in1  =  inputs[0];
    float* in2  =  inputs[1];
    float* out1 = outputs[0];
    float* out2 = outputs[1];

	long double inputSampleL;
	long double inputSampleR;
	long double outputSampleL;
	long double outputSampleR;
	double trim = 2.302585092994045684017991; //natural logarithm of 10
	    
    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.
		}

		outputSampleL = (inputSampleL - lastSampleL)*trim;
		outputSampleR = (inputSampleR - lastSampleR)*trim;
		lastSampleL = inputSampleL;
		lastSampleR = inputSampleR;
		if (outputSampleL > 1.0) outputSampleL = 1.0;
		if (outputSampleR > 1.0) outputSampleR = 1.0;
		if (outputSampleL < -1.0) outputSampleL = -1.0;		
		if (outputSampleR < -1.0) outputSampleR = -1.0;		
		
		*out1 = outputSampleL;
		*out2 = outputSampleR;

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

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

	long double inputSampleL;
	long double inputSampleR;
	long double outputSampleL;
	long double outputSampleR;
	double trim = 2.302585092994045684017991; //natural logarithm of 10
	
    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.
		}
		
		
		outputSampleL = (inputSampleL - lastSampleL)*trim;
		outputSampleR = (inputSampleR - lastSampleR)*trim;
		lastSampleL = inputSampleL;
		lastSampleR = inputSampleR;
		if (outputSampleL > 1.0) outputSampleL = 1.0;
		if (outputSampleR > 1.0) outputSampleR = 1.0;
		if (outputSampleL < -1.0) outputSampleL = -1.0;		
		if (outputSampleR < -1.0) outputSampleR = -1.0;		
		
		*out1 = outputSampleL;
		*out2 = outputSampleR;
		
		*in1++;
		*in2++;
		*out1++;
		*out2++;
    }
}