airwindows/plugins/WinVST/TapeHack/TapeHackProc.cpp

/* ========================================
 *  TapeHack - TapeHack.h
 *  Copyright (c) airwindows, Airwindows uses the MIT license
 * ======================================== */

#ifndef __TapeHack_H
#include "TapeHack.h"
#endif

void TapeHack::processReplacing(float **inputs, float **outputs, VstInt32 sampleFrames) 
{
    float* in1  =  inputs[0];
    float* in2  =  inputs[1];
    float* out1 = outputs[0];
    float* out2 = outputs[1];
	
	double inputGain = A*10.0;
	double outputGain = B*0.9239;
	double wet = C;
	
    while (--sampleFrames >= 0)
    {
		double inputSampleL = *in1;
		double inputSampleR = *in2;
		if (fabs(inputSampleL)<1.18e-23) inputSampleL = fpdL * 1.18e-17;
		if (fabs(inputSampleR)<1.18e-23) inputSampleR = fpdR * 1.18e-17;
		double drySampleL = inputSampleL;
		double drySampleR = inputSampleR;
		
		inputSampleL = fmax(fmin(inputSampleL*inputGain,2.305929007734908),-2.305929007734908);
		double addtwo = inputSampleL * inputSampleL;
		double empower = inputSampleL * addtwo; // inputSample to the third power
		inputSampleL -= (empower / 6.0);
		empower *= addtwo; // to the fifth power
		inputSampleL += (empower / 69.0);
		empower *= addtwo; //seventh
		inputSampleL -= (empower / 2530.08);
		empower *= addtwo; //ninth
		inputSampleL += (empower / 224985.6);
		empower *= addtwo; //eleventh
		inputSampleL -= (empower / 9979200.0f);
		//this is a degenerate form of a Taylor Series to approximate sin()
		
		inputSampleR = fmax(fmin(inputSampleR*inputGain,2.305929007734908),-2.305929007734908);
		addtwo = inputSampleR * inputSampleR;
		empower = inputSampleR * addtwo; // inputSample to the third power
		inputSampleR -= (empower / 6.0);
		empower *= addtwo; // to the fifth power
		inputSampleR += (empower / 69.0);
		empower *= addtwo; //seventh
		inputSampleR -= (empower / 2530.08);
		empower *= addtwo; //ninth
		inputSampleR += (empower / 224985.6);
		empower *= addtwo; //eleventh
		inputSampleR -= (empower / 9979200.0f);
		//this is a degenerate form of a Taylor Series to approximate sin()
		
		inputSampleL = (inputSampleL * outputGain * wet) + (drySampleL * (1.0-wet));
		inputSampleR = (inputSampleR * outputGain * wet) + (drySampleR * (1.0-wet));
		
		//begin 32 bit stereo floating point dither
		int expon; frexpf((float)inputSampleL, &expon);
		fpdL ^= fpdL << 13; fpdL ^= fpdL >> 17; fpdL ^= fpdL << 5;
		inputSampleL += ((double(fpdL)-uint32_t(0x7fffffff)) * 5.5e-36l * pow(2,expon+62));
		frexpf((float)inputSampleR, &expon);
		fpdR ^= fpdR << 13; fpdR ^= fpdR >> 17; fpdR ^= fpdR << 5;
		inputSampleR += ((double(fpdR)-uint32_t(0x7fffffff)) * 5.5e-36l * pow(2,expon+62));
		//end 32 bit stereo floating point dither
		
		*out1 = inputSampleL;
		*out2 = inputSampleR;

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

void TapeHack::processDoubleReplacing(double **inputs, double **outputs, VstInt32 sampleFrames) 
{
    double* in1  =  inputs[0];
    double* in2  =  inputs[1];
    double* out1 = outputs[0];
    double* out2 = outputs[1];
	
	double inputGain = A*10.0;
	double outputGain = B*0.9239;
	double wet = C;
	
    while (--sampleFrames >= 0)
    {
		double inputSampleL = *in1;
		double inputSampleR = *in2;
		if (fabs(inputSampleL)<1.18e-23) inputSampleL = fpdL * 1.18e-17;
		if (fabs(inputSampleR)<1.18e-23) inputSampleR = fpdR * 1.18e-17;
		double drySampleL = inputSampleL;
		double drySampleR = inputSampleR;
		
		inputSampleL = fmax(fmin(inputSampleL*inputGain,2.305929007734908),-2.305929007734908);
		double addtwo = inputSampleL * inputSampleL;
		double empower = inputSampleL * addtwo; // inputSample to the third power
		inputSampleL -= (empower / 6.0);
		empower *= addtwo; // to the fifth power
		inputSampleL += (empower / 69.0);
		empower *= addtwo; //seventh
		inputSampleL -= (empower / 2530.08);
		empower *= addtwo; //ninth
		inputSampleL += (empower / 224985.6);
		empower *= addtwo; //eleventh
		inputSampleL -= (empower / 9979200.0f);
		//this is a degenerate form of a Taylor Series to approximate sin()
		
		inputSampleR = fmax(fmin(inputSampleR*inputGain,2.305929007734908),-2.305929007734908);
		addtwo = inputSampleR * inputSampleR;
		empower = inputSampleR * addtwo; // inputSample to the third power
		inputSampleR -= (empower / 6.0);
		empower *= addtwo; // to the fifth power
		inputSampleR += (empower / 69.0);
		empower *= addtwo; //seventh
		inputSampleR -= (empower / 2530.08);
		empower *= addtwo; //ninth
		inputSampleR += (empower / 224985.6);
		empower *= addtwo; //eleventh
		inputSampleR -= (empower / 9979200.0f);
		//this is a degenerate form of a Taylor Series to approximate sin()
		
		inputSampleL = (inputSampleL * outputGain * wet) + (drySampleL * (1.0-wet));
		inputSampleR = (inputSampleR * outputGain * wet) + (drySampleR * (1.0-wet));
		
		//begin 64 bit stereo floating point dither
		//int expon; frexp((double)inputSampleL, &expon);
		fpdL ^= fpdL << 13; fpdL ^= fpdL >> 17; fpdL ^= fpdL << 5;
		//inputSampleL += ((double(fpdL)-uint32_t(0x7fffffff)) * 1.1e-44l * pow(2,expon+62));
		//frexp((double)inputSampleR, &expon);
		fpdR ^= fpdR << 13; fpdR ^= fpdR >> 17; fpdR ^= fpdR << 5;
		//inputSampleR += ((double(fpdR)-uint32_t(0x7fffffff)) * 1.1e-44l * pow(2,expon+62));
		//end 64 bit stereo floating point dither
		
		*out1 = inputSampleL;
		*out2 = inputSampleR;

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