Implemented basic BPM mechanism

trackdeck.cpp

@@ -9,6 +9,7 @@
 #include <QTextStream>
 #include <QUrl>
 #include <QFileInfo>
+#include <QButtonGroup>
 #include <QDebug>
 
 #include "audiodecoder.h"
@@ -20,12 +21,36 @@ TrackDeck::TrackDeck(QWidget *parent) :
     m_ui->setupUi(this);
     m_ui->progressBar->hide();
 
+    m_loopGroup.addButton(m_ui->pushButtonLoopOff, -1);
+    m_loopGroup.addButton(m_ui->pushButtonLoop1, 1);
+    m_loopGroup.addButton(m_ui->pushButtonLoop2, 2);
+    m_loopGroup.addButton(m_ui->pushButtonLoop4, 4);
+    m_loopGroup.addButton(m_ui->pushButtonLoop8, 8);
+    connect(&m_loopGroup, qOverload<int>(&QButtonGroup::buttonClicked), [&player=m_player,&bpmInput=*m_ui->doubleSpinBoxBpm](int id){
+        const auto position = player.position();
+
+        const auto bpm = bpmInput.value();
+        const auto beatsPerSecond = bpm / 60.;
+        const auto framesPerBeat = frameRate / beatsPerSecond;
+
+        switch (id)
+        {
+        case 1: player.setLoop(std::make_pair(position, position + (framesPerBeat/4))); break;
+        case 2: player.setLoop(std::make_pair(position, position + (framesPerBeat/2))); break;
+        case 4: player.setLoop(std::make_pair(position, position + framesPerBeat)); break;
+        case 8: player.setLoop(std::make_pair(position, position + (framesPerBeat*2))); break;
+        default: player.setLoop({});
+        }
+    });
+
+    connect(m_ui->pushButtonBpm, &QAbstractButton::pressed, this, &TrackDeck::bpmTap);
+
     connect(m_ui->pushButtonPlay, &QAbstractButton::pressed, &m_player, &AudioPlayer::togglePlaying);
     connect(m_ui->pushButtonStop, &QAbstractButton::pressed, &m_player, &AudioPlayer::stop);
 
-    connect(m_ui->verticalSliderVolume, &QAbstractSlider::valueChanged, &m_player, [&player=m_player](int value){ player.setVolume(float(value)/100.f); });
-
-    connect(m_ui->horizontalSliderSpeed, &QAbstractSlider::valueChanged, this, &TrackDeck::speedChanged);
+    connect(m_ui->sliderZoom, &QAbstractSlider::valueChanged, m_ui->scratchWidget, &ScratchWidget::setBeatWidth);
+    connect(m_ui->sliderSpeed, &QAbstractSlider::valueChanged, this, &TrackDeck::speedChanged);
+    connect(m_ui->sliderVolume, &QAbstractSlider::valueChanged, &m_player, [&player=m_player](int value){ player.setVolume(float(value)/100.f); });
 
     connect(m_ui->previewWidget, &PreviewWidget::positionSelected, &m_player, &AudioPlayer::setPosition);
     connect(&m_player, &AudioPlayer::positionChanged, m_ui->previewWidget, &PreviewWidget::setPosition);
@@ -33,6 +58,15 @@ TrackDeck::TrackDeck(QWidget *parent) :
     connect(m_ui->scratchWidget, &ScratchWidget::scratchEnd, this, &TrackDeck::scratchEnd);
     connect(&m_player, &AudioPlayer::positionChanged, m_ui->scratchWidget, &ScratchWidget::setPosition);
     connect(&m_player, &AudioPlayer::playingChanged, this, &TrackDeck::updatePlayButtonText);
+
+    connect(m_ui->sliderSpeed, &QAbstractSlider::valueChanged, this, &TrackDeck::updatePlaybackBpm);
+    connect(m_ui->doubleSpinBoxBpm, &QDoubleSpinBox::valueChanged, this, &TrackDeck::updatePlaybackBpm);
+
+    connect(&m_timer, &QTimer::timeout, this, &TrackDeck::timeout);
+    m_timer.setSingleShot(true);
+    m_timer.setInterval(1000);
+
+    updatePlaybackBpm();
 }
 
 TrackDeck::~TrackDeck() = default;
@@ -141,6 +175,12 @@ void TrackDeck::decodingProgress(int progress, int total)
 void TrackDeck::decodingFinished(const QAudioBuffer &buffer)
 {
     m_player.setBuffer(buffer);
+
+    m_ui->labelTitle->setText(QFileInfo{m_filename}.fileName());
+
+    for (auto *btn : m_loopGroup.buttons())
+        btn->setEnabled(false);
+
     m_ui->previewWidget->setBuffer(buffer);
     m_ui->scratchWidget->setBuffer(buffer);
     m_ui->progressBar->hide();
@@ -148,8 +188,8 @@ void TrackDeck::decodingFinished(const QAudioBuffer &buffer)
 
 void TrackDeck::scratchBegin()
 {
-    disconnect(m_ui->horizontalSliderSpeed, &QAbstractSlider::valueChanged, this, &TrackDeck::speedChanged);
-    m_ui->horizontalSliderSpeed->setEnabled(false);
+    disconnect(m_ui->sliderSpeed, &QAbstractSlider::valueChanged, this, &TrackDeck::speedChanged);
+    m_ui->sliderSpeed->setEnabled(false);
     connect(m_ui->scratchWidget, &ScratchWidget::scratchSpeed, &m_player, &AudioPlayer::setSpeed);
     disconnect(&m_player, &AudioPlayer::playingChanged, this, &TrackDeck::updatePlayButtonText);
 
@@ -169,8 +209,8 @@ void TrackDeck::scratchEnd()
     m_player.setStopOnEnd(m_stopOnEndBeforeScratch);
 
     disconnect(m_ui->scratchWidget, &ScratchWidget::scratchSpeed, &m_player, &AudioPlayer::setSpeed);
-    m_ui->horizontalSliderSpeed->setEnabled(true);
-    connect(m_ui->horizontalSliderSpeed, &QAbstractSlider::valueChanged, this, &TrackDeck::speedChanged);
+    m_ui->sliderSpeed->setEnabled(true);
+    connect(m_ui->sliderSpeed, &QAbstractSlider::valueChanged, this, &TrackDeck::speedChanged);
     connect(&m_player, &AudioPlayer::playingChanged, this, &TrackDeck::updatePlayButtonText);
 }
 
@@ -181,5 +221,46 @@ void TrackDeck::speedChanged(int value)
 
 void TrackDeck::updatePlayButtonText(bool playing)
 {
-        m_ui->pushButtonPlay->setText(playing ? tr("▮▮") : tr("▶"));
+    m_ui->pushButtonBpm->setEnabled(playing);
+    m_ui->pushButtonPlay->setText(playing ? tr("▮▮") : tr("▶"));
+}
+
+void TrackDeck::bpmTap()
+{
+    const auto position = m_player.position();
+    if (m_bpmTap)
+    {
+        std::get<1>(*m_bpmTap) = position;
+        std::get<2>(*m_bpmTap)++;
+        const auto framesPerBeat = (std::get<1>(*m_bpmTap)-std::get<0>(*m_bpmTap))/std::get<2>(*m_bpmTap);
+        const auto beatsPerSecond = frameRate/framesPerBeat;
+        const auto bpm = 60.*beatsPerSecond;
+        qDebug() << "framesPerBeat =" << framesPerBeat << "beatsPerSecond =" << beatsPerSecond << "bpm =" << bpm;
+        m_ui->doubleSpinBoxBpm->setValue(bpm);
+    }
+    else
+    {
+        m_bpmTap = std::make_tuple(position, position, 0);
+    }
+
+    m_ui->pushButtonBpm->setText(QString::number(std::get<2>(*m_bpmTap)));
+    m_timer.start();
+}
+
+void TrackDeck::timeout()
+{
+    const auto framesPerBeat = (std::get<1>(*m_bpmTap)-std::get<0>(*m_bpmTap))/std::get<2>(*m_bpmTap);
+    const auto beatsPerSecond = frameRate/framesPerBeat;
+    const auto bpm = 60.*beatsPerSecond;
+    qDebug() << "framesPerBeat =" << framesPerBeat << "beatsPerSecond =" << beatsPerSecond << "bpm =" << bpm;
+    m_ui->pushButtonBpm->setText(tr("BPM tap"));
+    m_ui->doubleSpinBoxBpm->setValue(bpm);
+    for (auto *btn : m_loopGroup.buttons())
+        btn->setEnabled(true);
+    m_bpmTap = {};
+}
+
+void TrackDeck::updatePlaybackBpm()
+{
+    m_ui->labelPlaybackBpm->setText(QString::number(m_ui->doubleSpinBoxBpm->value() * m_ui->sliderSpeed->value() / 100., 'f', 2));
 }