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#include "datamodifier.h"
#include <QDebug>
CDataModifier::CDataModifier()
{
m_SampleRate = 1;
m_SweepRate = 1;
m_SweepStartFrequency = 1;
m_SweepStopFrequency = 1;
}
void CDataModifier::Init(TYPEREAL SampleRate)
{
m_SampleRate = SampleRate;
//initialize sweep generator values
m_SweepFrequency = m_SweepStartFrequency;
m_SweepFreqNorm = K_2PI/m_SampleRate;
m_SweepAcc = 0.0;
m_SweepRateInc = m_SweepRate/m_SampleRate;
m_SweepDirUp = true;
if(m_SweepStartFrequency>=m_SweepStopFrequency)
m_SweepDirUp = true;
else
m_SweepDirUp = false;
}
//////////////////////////////////////////////////////////////////////
//
//////////////////////////////////////////////////////////////////////
void CDataModifier::SetSweepStart(int start)
{
m_SweepStartFrequency = (TYPEREAL)start;
m_SweepFrequency = m_SweepStartFrequency;
m_SweepAcc = 0.0;
if(m_SweepStartFrequency>=m_SweepStopFrequency)
m_SweepDirUp = true;
else
m_SweepDirUp = false;
}
void CDataModifier::SetSweepStop(int stop)
{
m_SweepStopFrequency = (TYPEREAL)stop;
m_SweepFrequency = m_SweepStartFrequency;
m_SweepAcc = 0.0;
if(m_SweepStartFrequency>=m_SweepStopFrequency)
m_SweepDirUp = true;
else
m_SweepDirUp = false;
}
void CDataModifier::SetSweepRate(TYPEREAL rate)
{
m_SweepRate = rate; // Hz/sec
m_SweepAcc = 0.0;
m_SweepRateInc = m_SweepRate/m_SampleRate;
}
void CDataModifier::SetSignalPower( TYPEREAL PwrdB)
{
m_SignalAmplitude = 1.0*MPOW(10.0, PwrdB/20.0);
}
void CDataModifier::SetNoisePower( TYPEREAL NoisedB)
{
m_NoisePower = NoisedB;
m_NoiseAmplitude = 1.0*MPOW(10.0, NoisedB/20.0);
}
void CDataModifier::ProcessBlock(TYPECPX* pBuf, int NumSamples)
{
TYPECPX dtmp;
TYPECPX Osc;
TYPEREAL r;
TYPEREAL rad;
TYPEREAL u1;
TYPEREAL u2;
for(int i=0; i<NumSamples; i++)
{
//create complex sin/cos modulation signal
Osc.re = m_SignalAmplitude * MCOS(m_SweepAcc);
Osc.im = m_SignalAmplitude * MSIN(m_SweepAcc);
//inc phase accummulator with normalized freqeuency step
m_SweepAcc += ( m_SweepFrequency*m_SweepFreqNorm );
if( m_SweepDirUp )
{
m_SweepFrequency += m_SweepRateInc; //inc sweep frequency
if(m_SweepFrequency >= m_SweepStopFrequency) //reached end of sweep?
m_SweepDirUp = false;
}
else
{
m_SweepFrequency -= m_SweepRateInc; //dec sweep frequency
if(m_SweepFrequency <= m_SweepStartFrequency) //reached start of sweep?
m_SweepDirUp = true;
}
//Cpx multiply by shift frequency
dtmp = pBuf[i];
pBuf[i].re = ((dtmp.re * Osc.re) - (dtmp.im * Osc.im));
pBuf[i].im = ((dtmp.re * Osc.im) + (dtmp.im * Osc.re));
////////////////// Gaussian Noise generator
// Generate two uniform random numbers between -1 and +1
// that are inside the unit circle
if(m_NoisePower > -160.0)
{ //create and add noise samples to signal
do {
u1 = 1.0 - 2.0 * (TYPEREAL)rand()/(TYPEREAL)RAND_MAX ;
u2 = 1.0 - 2.0 * (TYPEREAL)rand()/(TYPEREAL)RAND_MAX ;
r = u1*u1 + u2*u2;
} while(r >= 1.0 || r == 0.0);
rad = MSQRT(-2.0*MLOG(r)/r);
//add noise samples to generator output
pBuf[i].re += (m_NoiseAmplitude*u1*rad);
pBuf[i].im += (m_NoiseAmplitude*u2*rad);
}
}
m_SweepAcc = (TYPEREAL)MFMOD((TYPEREAL)m_SweepAcc, K_2PI); //keep radian counter bounded
}
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