Files
DrumMachine/synthisizer.cpp

34 lines
988 B
C++

#include "synthisizer.h"
#include <cmath>
#include "midicontainers.h"
constexpr double pi = std::acos(-1);
void Synthisizer::writeSamples(frame_t *begin, frame_t *end)
{
if (m_frequency)
std::transform(begin, end, begin, [&](frame_t frame){
std::transform(std::cbegin(frame), std::cend(frame), std::begin(frame),
[value=std::sin(m_phase)](const sample_t &sample) { return sample + value; });
m_phase += pi*2./sampleRate*m_frequency;
if (m_phase >= pi*2.)
m_phase -= pi*2.;
return frame;
});
}
void Synthisizer::messageReceived(const midi::MidiMessage &message)
{
if (message.cmd == midi::Command::NoteOn)
m_frequency = 440.*std::pow(std::pow(2., 1./12.), message.note-48);
else if (message.cmd == midi::Command::NoteOff)
{
if (m_frequency == int16_t(440.*std::pow(std::pow(2., 1./12.), message.note-48)))
m_frequency = 0;
}
}