Files
DrumMachine/audioplayer.cpp

137 lines
3.0 KiB
C++

#include "audioplayer.h"
#include <algorithm>
#include <cmath>
#include "audioformat.h"
AudioPlayer::AudioPlayer(QObject *parent) :
QObject{parent}
{
}
AudioPlayer::AudioPlayer(const QAudioBuffer &buffer, QObject *parent) :
QObject{parent},
m_buffer{buffer}
{
}
void AudioPlayer::writeSamples(frame_t *begin, frame_t *end)
{
if (!m_playing)
return;
// thread safe copies
auto position = m_position;
const auto speed = m_speed;
const auto buffer = m_buffer;
const auto volume = m_volume;
const auto stopOnEnd = m_stopOnEnd;
const auto &data = buffer.constData<frame_t>();
const auto loop = m_loop;
const auto frames = std::min<size_t>(std::distance(begin, end), buffer.frameCount()-position);
if (!frames)
{
m_playing = false;
emit playingChanged(false);
return;
}
bool ended{};
std::transform(static_cast<const frame_t *>(begin), static_cast<const frame_t *>(begin+frames), begin,
[&](frame_t frame)->frame_t{
if (ended && stopOnEnd)
return frame;
const auto index = std::ptrdiff_t(position);
position += speed;
if (loop)
{
if (speed < 0 && position < loop->first)
position = loop->second;
else if (speed > 0 && position > loop->second)
position = loop->first;
}
if ((speed < 0.f && index < 0) || (speed > 0.f && index >= buffer.frameCount()))
{
ended = true;
return frame;
}
if (index < 0 || index >= buffer.frameCount())
return frame;
const frame_t &frame2 = data[index];
std::transform(std::cbegin(frame), std::cend(frame), std::begin(frame2), std::begin(frame),
[&volume](const sample_t &left, const sample_t &right) { return left + (right*volume); });
return frame;
});
m_position = position;
const auto now = QDateTime::currentDateTime();
if (m_lastPositionUpdate.isNull() || m_lastPositionUpdate.msecsTo(now) > 1000/30)
{
emit positionChanged(m_position);
m_lastPositionUpdate = now;
}
if (ended && stopOnEnd)
{
m_playing = false;
emit playingChanged(m_playing);
}
}
void AudioPlayer::setPlaying(bool playing)
{
m_playing = playing;
emit playingChanged(playing);
}
void AudioPlayer::setPosition(double position)
{
m_position = position;
emit positionChanged(position);
}
void AudioPlayer::setSpeed(float speed)
{
m_speed = speed;
emit speedChanged(speed);
}
void AudioPlayer::setVolume(float volume)
{
m_volume = volume;
emit volumeChanged(volume);
}
void AudioPlayer::setBuffer(const QAudioBuffer &buffer)
{
stop();
emit bufferChanged(m_buffer = buffer);
}
void AudioPlayer::togglePlaying()
{
emit playingChanged(m_playing = !m_playing);
}
void AudioPlayer::restart()
{
setPosition(0.);
setPlaying(true);
}
void AudioPlayer::stop()
{
setPosition(0.);
setPlaying(false);
}