Add Sample Clip Fading

include/Clip.h

@@ -151,6 +151,30 @@ class LMMS_EXPORT Clip : public Model, public JournallingObject
 	TimePos startTimeOffset() const;
 	void setStartTimeOffset( const TimePos &startTimeOffset );
 
+	TimePos startCrossfadeLength() const { return m_startCrossfadeLength; }
+	void setStartCrossfadeLength(const TimePos& startCrossfadeLength)
+	{
+		m_startCrossfadeLength = std::max(TimePos{0}, startCrossfadeLength);
+	}
+	TimePos endCrossfadeLength() const { return m_endCrossfadeLength; }
+	void setEndCrossfadeLength(const TimePos &endCrossfadeLength)
+	{
+		m_endCrossfadeLength = std::max(TimePos{0}, endCrossfadeLength);
+	}
+
+	float startCrossfadeTension() const { return m_startCrossfadeTension; }
+	void setStartCrossfadeTension(float startCrossfadeTension)
+	{
+		m_startCrossfadeTension = std::clamp(startCrossfadeTension, 0.0f, 1.0f);
+	}
+	float endCrossfadeTension() const { return m_endCrossfadeTension; }
+	void setEndCrossfadeTension(float endCrossfadeTension)
+	{
+		m_endCrossfadeTension = std::clamp(endCrossfadeTension, 0.0f, 1.0f);
+	}
+
+	virtual bool isCrossfadeable() const { return false; }
+
 	// Will copy the state of a clip to another clip
 	static void copyStateTo( Clip *src, Clip *dst );
 
@@ -181,6 +205,11 @@ public slots:
 	TimePos m_length;
 	TimePos m_startTimeOffset;
 
+	TimePos m_startCrossfadeLength;
+	TimePos m_endCrossfadeLength;
+	float m_startCrossfadeTension;
+	float m_endCrossfadeTension;
+
 	BoolModel m_mutedModel;
 	BoolModel m_soloModel;
 	bool m_resizable = true;

include/ClipView.h

@@ -169,6 +169,7 @@ public slots:
 	void mousePressEvent( QMouseEvent * me ) override;
 	void mouseMoveEvent( QMouseEvent * me ) override;
 	void mouseReleaseEvent( QMouseEvent * me ) override;
+	void leaveEvent(QEvent * e) override;
 	void resizeEvent( QResizeEvent * re ) override
 	{
 		m_needsUpdate = true;
@@ -184,6 +185,7 @@ public slots:
 	DataFile createClipDataFiles(const QVector<ClipView *> & clips) const;
 
 	virtual void paintTextLabel(QString const & text, QPainter & painter);
+	virtual void drawCrossfade(QPainter& painter, QRect rect);
 
 	auto hasCustomColor() const -> bool;
 
@@ -200,6 +202,10 @@ protected slots:
 		MoveSelection,
 		Resize,
 		ResizeLeft,
+		EditStartCrossfade,
+		EditEndCrossfade,
+		EditStartCrossfadeTension,
+		EditEndCrossfadeTension,
 		Split,
 		CopySelection,
 		ToggleSelected
@@ -231,6 +237,11 @@ protected slots:
 	QCursor m_cursorKnife;
 	bool m_cursorSetYet;
 
+	bool m_mouseOverStartCrossfadeHandle;
+	bool m_mouseOverStartCrossfadeTensionHandle;
+	bool m_mouseOverEndCrossfadeHandle;
+	bool m_mouseOverEndCrossfadeTensionHandle;
+
 	bool m_needsUpdate;
 	inline void setInitialPos( QPoint pos )
 	{

include/SampleClip.h

@@ -80,14 +80,16 @@ class SampleClip : public Clip
 	void setIsPlaying(bool isPlaying);
 	void setSampleBuffer(std::shared_ptr<const SampleBuffer> sb);
 
+	bool isCrossfadeable() const override { return true; }
+
 	SampleClip* clone() override
 	{
 		return new SampleClip(*this);
 	}
 
 public slots:
 	void setSampleFile(const QString& sf);
-	void updateLength();
+	void updateLength() override;
 	void toggleRecord();
 	void playbackPositionChanged();
 	void updateTrackClips();

include/SamplePlayHandle.h

@@ -93,6 +93,7 @@ class LMMS_EXPORT SamplePlayHandle : public PlayHandle
 	FloatModel m_defaultVolumeModel;
 	FloatModel * m_volumeModel;
 	Track * m_track;
+	SampleClip * m_clip;
 
 	PatternTrack* m_patternTrack;
 

src/core/Clip.cpp

@@ -47,6 +47,10 @@ Clip::Clip( Track * track ) :
 	m_track( track ),
 	m_startPosition(),
 	m_length(),
+	m_startCrossfadeLength(0),
+	m_endCrossfadeLength(0),
+	m_startCrossfadeTension(1.0f - std::sqrt(2) / 2),
+	m_endCrossfadeTension(1.0f - std::sqrt(2) / 2),
 	m_mutedModel( false, this, tr( "Mute" ) ),
 	m_selectViewOnCreate{false}
 {
@@ -74,6 +78,10 @@ Clip::Clip(const Clip& other):
 	m_startPosition(other.m_startPosition),
 	m_length(other.m_length),
 	m_startTimeOffset(other.m_startTimeOffset),
+	m_startCrossfadeLength(other.m_startCrossfadeLength),
+	m_endCrossfadeLength(other.m_endCrossfadeLength),
+	m_startCrossfadeTension(other.m_startCrossfadeTension),
+	m_endCrossfadeTension(other.m_endCrossfadeTension),
 	m_mutedModel(other.m_mutedModel.value(), this, tr( "Mute" )),
 	m_resizable(other.m_resizable),
 	m_autoResize(other.m_autoResize),
@@ -137,6 +145,8 @@ void Clip::movePosition( const TimePos & pos )
 void Clip::changeLength( const TimePos & length )
 {
 	m_length = length;
+	setStartCrossfadeLength(std::min(m_startCrossfadeLength, m_length));
+	setEndCrossfadeLength(std::min(m_endCrossfadeLength, m_length));
 	Engine::getSong()->updateLength();
 	emit lengthChanged();
 }

src/core/SampleClip.cpp

@@ -26,6 +26,7 @@
 
 #include <QDomElement>
 #include <QFileInfo>
+#include <numbers>
 
 #include "PathUtil.h"
 #include "SampleBuffer.h"
@@ -308,6 +309,10 @@ void SampleClip::saveSettings( QDomDocument & _doc, QDomElement & _this )
 	_this.setAttribute( "src", sampleFile() );
 	_this.setAttribute( "off", startTimeOffset() );
 	_this.setAttribute("autoresize", QString::number(getAutoResize()));
+	_this.setAttribute("startfadelength", QString::number(startCrossfadeLength()));
+	_this.setAttribute("endfadelength", QString::number(endCrossfadeLength()));
+	_this.setAttribute("startfadetension", QString::number(startCrossfadeTension()));
+	_this.setAttribute("endfadetension", QString::number(endCrossfadeTension()));
 	if( sampleFile() == "" )
 	{
 		QString s;
@@ -357,6 +362,10 @@ void SampleClip::loadSettings( const QDomElement & _this )
 	setMuted( _this.attribute( "muted" ).toInt() );
 	setStartTimeOffset( _this.attribute( "off" ).toInt() );
 	setAutoResize(_this.attribute("autoresize", "1").toInt());
+	setStartCrossfadeLength(_this.attribute("startfadelength").toInt());
+	setEndCrossfadeLength(_this.attribute("endfadelength").toInt());
+	setStartCrossfadeTension(_this.attribute("startfadetension", QString::number(1.0f - std::numbers::sqrt2 / 2)).toFloat());
+	setEndCrossfadeTension(_this.attribute("endfadetension", QString::number(1.0f - std::numbers::sqrt2 / 2)).toFloat());
 
 	if (_this.hasAttribute("color"))
 	{

src/core/SamplePlayHandle.cpp

@@ -26,6 +26,8 @@
 #include "AudioEngine.h"
 #include "AudioBusHandle.h"
 #include "Engine.h"
+#include "lmms_math.h"
+#include "MixHelpers.h"
 #include "Note.h"
 #include "PatternTrack.h"
 #include "SampleClip.h"
@@ -44,6 +46,7 @@
 	m_defaultVolumeModel(DefaultVolume, MinVolume, MaxVolume, 1),
 	m_volumeModel(&m_defaultVolumeModel),
 	m_track(nullptr),
+	m_clip(nullptr),
 	m_patternTrack(nullptr)
 {
 	if (ownAudioBusHandle)
@@ -66,6 +69,7 @@
 SamplePlayHandle::SamplePlayHandle( SampleClip* clip ) :
 	SamplePlayHandle(&clip->sample(), false)
 {
+	m_clip = clip;
 	m_track = clip->getTrack();
 	setAudioBusHandle(((SampleTrack *)clip->getTrack())->audioBusHandle());
 }
@@ -84,43 +88,80 @@
 
 
 
 
 void SamplePlayHandle::play( SampleFrame* buffer )
 {
 	const fpp_t fpp = Engine::audioEngine()->framesPerPeriod();
 	//play( 0, _try_parallelizing );
 	if( framesDone() >= totalFrames() )
 	{
 		zeroSampleFrames(buffer, fpp);
 		return;
 	}
 
 	SampleFrame* workingBuffer = buffer;
 	f_cnt_t frames = fpp;
 
 	// apply offset for the first period
 	if( framesDone() == 0 )
 	{
 		zeroSampleFrames(buffer, offset());
 		workingBuffer += offset();
 		frames -= offset();
 	}
 
+	const f_cnt_t initialFrameIndex = m_state.frameIndex();
+
 	if( !( m_track && m_track->isMuted() )
 				&& !(m_patternTrack && m_patternTrack->isMuted()))
 	{
 /*		StereoVolumeVector v =
 			{ { m_volumeModel->value() / DefaultVolume,
 				m_volumeModel->value() / DefaultVolume } };*/
 		// SamplePlayHandle always plays the sample at its original pitch;
 		// it is used only for previews, SampleTracks and the metronome.
 		if (!m_sample->play(workingBuffer, &m_state, frames, DefaultBaseFreq))
 		{
 			zeroSampleFrames(workingBuffer, frames);
 		}
+
+		// Apply crossfade if this play handle is for a clip
+		if (m_clip && (m_clip->startCrossfadeLength() != 0 || m_clip->endCrossfadeLength() != 0))
+		{
+			const int framesPerTick = Engine::framesPerTick(Engine::audioEngine()->outputSampleRate());
+			const int startCrossfadeFrames = m_clip->startCrossfadeLength() * framesPerTick;
+			const int endCrossfadeFrames = m_clip->endCrossfadeLength() * framesPerTick;
+			const int startOffsetFrames = m_clip->startTimeOffset() * framesPerTick;
+			const int lengthFrames = m_clip->length() * framesPerTick;
+			const float startPower = std::log(1.0f - m_clip->startCrossfadeTension()) / -std::numbers::ln2;
+			const float endPower = std::log(1.0f - m_clip->endCrossfadeTension()) / -std::numbers::ln2;
+
+			for (f_cnt_t f = 0; f < frames; ++f)
+			{
+				const f_cnt_t frameIndex = initialFrameIndex + f;
+				const int framesRelativeToClipStart = frameIndex + startOffsetFrames;
+				const int framesRelativeToClipEnd = lengthFrames - framesRelativeToClipStart;
+				if (framesRelativeToClipStart < 0 || framesRelativeToClipEnd < 0) { workingBuffer[f] = SampleFrame(); continue; }
+
+				if (framesRelativeToClipStart < startCrossfadeFrames && framesRelativeToClipEnd < endCrossfadeFrames)
+				{
+					workingBuffer[f] *=
+							fastPow(static_cast<float>(framesRelativeToClipStart) / static_cast<float>(startCrossfadeFrames), startPower)
+							* fastPow(static_cast<float>(framesRelativeToClipEnd) / static_cast<float>(endCrossfadeFrames), endPower);
+				}
+				else if (framesRelativeToClipStart < startCrossfadeFrames)
+				{
+					workingBuffer[f] *= fastPow(static_cast<float>(framesRelativeToClipStart) / static_cast<float>(startCrossfadeFrames), startPower);
+				}
+				else if (framesRelativeToClipEnd < endCrossfadeFrames)
+				{
+					workingBuffer[f] *= fastPow(static_cast<float>(framesRelativeToClipEnd) / static_cast<float>(endCrossfadeFrames), endPower);
+				}
+			}
+		}
 	}
 
 	m_frame += frames;
 }