samplingthread.cpp
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#include "samplingthread.h"
#include "signaldata.h"
#include <qwt_math.h>
#include <math.h>
#if QT_VERSION < 0x040600
#define qFastSin(x) ::sin(x)
#endif
SamplingThread::SamplingThread(QObject *parent):
QwtSamplingThread(parent),
d_frequency(5.0),
d_amplitude(20.0)
{
}
void SamplingThread::setFrequency(double frequency)
{
d_frequency = frequency;
}
double SamplingThread::frequency() const
{
return d_frequency;
}
void SamplingThread::setAmplitude(double amplitude)
{
d_amplitude = amplitude;
}
double SamplingThread::amplitude() const
{
return d_amplitude;
}
void SamplingThread::sample(double elapsed)
{
if ( d_frequency > 0.0 )
{
const QPointF s(elapsed, value(elapsed));
SignalData::instance().append(s);
}
}
double SamplingThread::value(double timeStamp) const
{
const double period = 1.0 / d_frequency;
const double x = ::fmod(timeStamp, period);
const double v = d_amplitude * qFastSin(x / period * 2 * M_PI);
return v;
}