Process metronome every MIDI tick (#7483)

include/AudioEngine.h

@@ -289,9 +289,6 @@ class LMMS_EXPORT AudioEngine : public QObject
 
 	void changeQuality(const struct qualitySettings & qs);
 
-	inline bool isMetronomeActive() const { return m_metronomeActive; }
-	inline void setMetronomeActive(bool value = true) { m_metronomeActive = value; }
-
 	//! Block until a change in model can be done (i.e. wait for audio thread)
 	void requestChangeInModel();
 	void doneChangeInModel();
@@ -352,8 +349,6 @@ class LMMS_EXPORT AudioEngine : public QObject
 
 	void swapBuffers();
 
-	void handleMetronome();
-
 	void clearInternal();
 
 	bool m_renderOnly;
@@ -402,8 +397,6 @@ class LMMS_EXPORT AudioEngine : public QObject
 
 	AudioEngineProfiler m_profiler;
 
-	bool m_metronomeActive;
-
 	bool m_clearSignal;
 
 	std::recursive_mutex m_changeMutex;

include/Metronome.h

@@ -0,0 +1,43 @@
+/*
+ * Metronome.h
+ *
+ * Copyright (c) 2024 saker
+ *
+ * This file is part of LMMS - https://lmms.io
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program (see COPYING); if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301 USA.
+ *
+ */
+
+#ifndef LMMS_METRONOME_H
+#define LMMS_METRONOME_H
+
+#include <cstddef>
+
+namespace lmms {
+class Metronome
+{
+public:
+	bool active() const { return m_active; }
+	void setActive(bool active) { m_active = active; }
+	void processTick(int currentTick, int ticksPerBar, int beatsPerBar, size_t bufferOffset);
+
+private:
+	bool m_active = false;
+};
+} // namespace lmms
+
+#endif // LMMS_METRONOME_H

include/Song.h

@@ -33,6 +33,7 @@
 
 #include "AudioEngine.h"
 #include "Controller.h"
+#include "Metronome.h"
 #include "lmms_constants.h"
 #include "MeterModel.h"
 #include "Timeline.h"
@@ -375,6 +376,8 @@ class LMMS_EXPORT Song : public TrackContainer
 
 	const std::string& syncKey() const noexcept { return m_vstSyncController.sharedMemoryKey(); }
 
+	Metronome& metronome() { return m_metronome; }
+
 public slots:
 	void playSong();
 	void record();
@@ -448,6 +451,7 @@ private slots:
 	void restoreKeymapStates(const QDomElement &element);
 
 	void processAutomations(const TrackList& tracks, TimePos timeStart, fpp_t frames);
+	void processMetronome(size_t bufferOffset);
 
 	void setModified(bool value);
 
@@ -513,6 +517,8 @@ private slots:
 
 	AutomatedValueMap m_oldAutomatedValues;
 
+	Metronome m_metronome;
+
 	friend class Engine;
 	friend class gui::SongEditor;
 	friend class gui::ControllerRackView;

src/core/AudioEngine.cpp

@@ -87,7 +87,6 @@ AudioEngine::AudioEngine( bool renderOnly ) :
 	m_oldAudioDev( nullptr ),
 	m_audioDevStartFailed( false ),
 	m_profiler(),
-	m_metronomeActive(false),
 	m_clearSignal(false)
 {
 	for( int i = 0; i < 2; ++i )
@@ -345,8 +344,6 @@ void AudioEngine::renderStageNoteSetup()
 	Mixer * mixer = Engine::mixer();
 	mixer->prepareMasterMix();
 
-	handleMetronome();
-
 	// create play-handles for new notes, samples etc.
 	Engine::getSong()->processNextBuffer();
 
@@ -459,55 +456,6 @@ void AudioEngine::swapBuffers()
 	zeroSampleFrames(m_outputBufferWrite.get(), m_framesPerPeriod);
 }
 
-
-
-
-void AudioEngine::handleMetronome()
-{
-	static tick_t lastMetroTicks = -1;
-
-	Song * song = Engine::getSong();
-	Song::PlayMode currentPlayMode = song->playMode();
-
-	bool metronomeSupported =
-		currentPlayMode == Song::PlayMode::MidiClip
-		|| currentPlayMode == Song::PlayMode::Song
-		|| currentPlayMode == Song::PlayMode::Pattern;
-
-	if (!metronomeSupported || !m_metronomeActive || song->isExporting())
-	{
-		return;
-	}
-
-	// stop crash with metronome if empty project
-	if (song->countTracks() == 0)
-	{
-		return;
-	}
-
-	tick_t ticks = song->getPlayPos(currentPlayMode).getTicks();
-	tick_t ticksPerBar = TimePos::ticksPerBar();
-	int numerator = song->getTimeSigModel().getNumerator();
-
-	if (ticks == lastMetroTicks)
-	{
-		return;
-	}
-
-	if (ticks % (ticksPerBar / 1) == 0)
-	{
-		addPlayHandle(new SamplePlayHandle("misc/metronome02.ogg"));
-	}
-	else if (ticks % (ticksPerBar / numerator) == 0)
-	{
-		addPlayHandle(new SamplePlayHandle("misc/metronome01.ogg"));
-	}
-
-	lastMetroTicks = ticks;
-}
-
-
-
 void AudioEngine::clear()
 {
 	m_clearSignal = true;

src/core/CMakeLists.txt

@@ -40,6 +40,7 @@ set(LMMS_SRCS
 	core/LinkedModelGroups.cpp
 	core/LocklessAllocator.cpp
 	core/MeterModel.cpp
+	core/Metronome.cpp
 	core/MicroTimer.cpp
 	core/Microtuner.cpp
 	core/MixHelpers.cpp

src/core/Metronome.cpp

@@ -0,0 +1,41 @@
+/*
+ * Metronome.cpp
+ *
+ * Copyright (c) 2024 saker
+ *
+ * This file is part of LMMS - https://lmms.io
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program (see COPYING); if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301 USA.
+ *
+ */
+
+#include "Metronome.h"
+
+#include "Engine.h"
+#include "SamplePlayHandle.h"
+
+namespace lmms {
+void Metronome::processTick(int currentTick, int ticksPerBar, int beatsPerBar, size_t bufferOffset)
+{
+	const auto ticksPerBeat = ticksPerBar / beatsPerBar;
+	if (currentTick % ticksPerBeat != 0 || !m_active) { return; }
+
+	const auto handle = currentTick % ticksPerBar == 0 ? new SamplePlayHandle("misc/metronome02.ogg")
+													   : new SamplePlayHandle("misc/metronome01.ogg");
+	handle->setOffset(bufferOffset);
+	Engine::audioEngine()->addPlayHandle(handle);
+}
+} // namespace lmms

src/core/Song.cpp

@@ -332,6 +332,8 @@ void Song::processNextBuffer()
 		{
 			// First frame of tick: process automation and play tracks
 			processAutomations(trackList, getPlayPos(), framesToPlay);
+			processMetronome(frameOffsetInPeriod);
+
 			for (const auto track : trackList)
 			{
 				track->play(getPlayPos(), framesToPlay, frameOffsetInPeriod, clipNum);
@@ -426,6 +428,17 @@ void Song::processAutomations(const TrackList &tracklist, TimePos timeStart, fpp
 	}
 }
 
+void Song::processMetronome(size_t bufferOffset)
+{
+	const auto currentPlayMode = playMode();
+	const auto supported = currentPlayMode == PlayMode::MidiClip
+		|| currentPlayMode == PlayMode::Song
+		|| currentPlayMode == PlayMode::Pattern;
+
+	if (!supported || m_exporting) { return; } 
+	m_metronome.processTick(currentTick(), ticksPerBar(), m_timeSigModel.getNumerator(), bufferOffset);
+}
+
 void Song::setModified(bool value)
 {
 	if( !m_loadingProject && m_modified != value)
@@ -1542,6 +1555,4 @@ void Song::setKeymap(unsigned int index, std::shared_ptr<Keymap> newMap)
 	emit keymapListChanged(index);
 	Engine::audioEngine()->doneChangeInModel();
 }
-
-
 } // namespace lmms

src/gui/MainWindow.cpp

@@ -43,6 +43,7 @@
 #include "ExportProjectDialog.h"
 #include "FileBrowser.h"
 #include "FileDialog.h"
+#include "Metronome.h"
 #include "MixerView.h"
 #include "GuiApplication.h"
 #include "ImportFilter.h"
@@ -430,7 +431,7 @@ void MainWindow::finalize()
 				this, SLOT(onToggleMetronome()),
 							m_toolBar );
 	m_metronomeToggle->setCheckable(true);
-	m_metronomeToggle->setChecked(Engine::audioEngine()->isMetronomeActive());
+	m_metronomeToggle->setChecked(Engine::getSong()->metronome().active());
 
 	m_toolBarLayout->setColumnMinimumWidth( 0, 5 );
 	m_toolBarLayout->addWidget( project_new, 0, 1 );
@@ -1173,7 +1174,7 @@ void MainWindow::updateConfig( QAction * _who )
 
 void MainWindow::onToggleMetronome()
 {
-	Engine::audioEngine()->setMetronomeActive( m_metronomeToggle->isChecked() );
+	Engine::getSong()->metronome().setActive(m_metronomeToggle->isChecked());
 }