Enable fading of samples in the Sample Track

include/SampleBuffer.h

@@ -48,6 +48,85 @@ class QRect;
 // may need to be higher - conversely, to optimize, some may work with lower values
 const f_cnt_t MARGIN[] = { 64, 64, 64, 4, 4 };
 
+
+class ControlPoint
+{
+public:
+	ControlPoint(float x, float y)
+	{
+		this->setX(x);
+		this->setY(y);
+	}
+
+	void setX(float x)
+	{
+		m_x = adjustPoint(x);
+	}
+
+	void setY(float y)
+	{
+		m_y = adjustPoint(y);
+	}
+
+	const float x() const
+	{
+		return m_x;
+	}
+
+	const float y() const
+	{
+		return m_y;
+	}
+
+private:
+	float m_x;
+	float m_y;
+	inline float adjustPoint(float val)
+	{
+		/*
+		Constrain the control points to lie in the interval [0.0, 1.0].
+		This ensures that the fade function has a unique value at each sample
+		and that the fade function can not go above 1.0 and below 0.0.
+		*/
+		return std::min(std::max(val, 0.0f), 1.0f);
+	}
+};
+
+
+class CubicBezier
+{
+/*
+Very comprehensive overview of Bezier curves:
+https://pomax.github.io/bezierinfo/
+*/
+public:
+	CubicBezier(float p1x, float p1y, float p2x, float p2y)
+	{
+		m_p1 = ControlPoint(p1x, p1y);
+		m_p2 = ControlPoint(p2x, p2y);
+	};
+
+	float evaluate(float);
+	ControlPoint m_p1 = ControlPoint(0.0f, 0.0f);
+	ControlPoint m_p2 = ControlPoint(0.0f, 0.0f);
+
+private:
+	float cubicBezier(float t, float p1, float p2);
+	float cubicBezierDerivative(float t, float p1, float p2);
+	float cubicBezierLastSegmentP1(float t, float p1, float p2);
+	float cubicBezierLastSegmentP2(float t, float p1, float p2);
+	// Solve with Newton's method: Very fast, but t might lie outside [0.0, 1.0]
+	float solveXforTNewton(float x, bool useCache);
+	// Solve with Bisection method: Slow, but t is guaranteed to lie inside [0.0, 1.0]
+	float solveXforTBisection(float x);
+	float solveXforT(float x)
+	{
+		return solveXforTBisection(x);
+	}
+	float m_tCache = -1.0f;
+};
+
+
 class LMMS_EXPORT SampleBuffer : public QObject, public sharedObject
 {
 	Q_OBJECT
@@ -273,6 +352,75 @@ class LMMS_EXPORT SampleBuffer : public QObject, public sharedObject
 	}
 
 
+	// Fading related members
+
+	float fadingVal(f_cnt_t pos, bool isLeft);
+
+	void setTcoStartTime(float startTime)
+	{
+		m_TcoStartTime = startTime;
+	}
+
+	void setTcoFrameLength(float len)
+	{
+		m_TcoFrameLength = len;
+	}
+
+	float leftFaderPos()
+	{
+		return m_leftFader;
+	}
+
+	float rightFaderPos()
+	{
+		return m_rightFader;
+	}
+
+	ControlPoint getLeftP1()
+	{
+		return m_leftBezierFade.m_p1;
+	}
+
+	ControlPoint getLeftP2()
+	{
+		return m_leftBezierFade.m_p2;
+	}
+
+	ControlPoint getRightP1()
+	{
+		return m_rightBezierFade.m_p1;
+	}
+
+	ControlPoint getRightP2()
+	{
+		return m_rightBezierFade.m_p2;
+	}
+
+	void setLeftP1(float x, float y)
+	{
+		m_leftBezierFade.m_p1 = ControlPoint(x, y);
+	}
+
+	void setLeftP2(float x, float y)
+	{
+		m_leftBezierFade.m_p2 = ControlPoint(x, y);
+	}
+
+	void setRightP1(float x, float y)
+	{
+		m_rightBezierFade.m_p1 = ControlPoint(1.0f - x, y);
+	}
+
+	void setRightP2(float x, float y)
+	{
+		m_rightBezierFade.m_p2 = ControlPoint(1.0f - x, y);
+	}
+
+	void setLeftFader(float lfader);
+	void setRightFader(float rfader);
+	void checkFadingActive();
+
+
 public slots:
 	void setAudioFile(const QString & audioFile);
 	void loadFromBase64(const QString & data);
@@ -340,11 +488,30 @@ public slots:
 	f_cnt_t getLoopedIndex(f_cnt_t index, f_cnt_t startf, f_cnt_t endf) const;
 	f_cnt_t getPingPongIndex(f_cnt_t index, f_cnt_t startf, f_cnt_t endf) const;
 
+	// Fading related members
+	bool m_fading = false;
+	float m_leftFader = 0.0f;
+	float m_rightFader = 1.0f;
+
+	f_cnt_t m_cachePos = -mixerSampleRate();
+	float m_cacheAmp = 1.0f;
+
+
+	CubicBezier m_leftBezierFade = CubicBezier(0.5f, 0.0f, 0.5f, 1.0f);
+	CubicBezier m_rightBezierFade = CubicBezier(0.5f, 0.0f, 0.5f, 1.0f);
+
+	float bezierFade(float, bool);
+	typedef float(SampleBuffer::*fadingFunc)(float, bool);
+	fadingFunc fadefuncPtr = &SampleBuffer::bezierFade;
+	float fadefunc(f_cnt_t);
+
+	float m_TcoStartTime = 0.0f;
+	float m_TcoFrameLength = 0.0f;
+
 
 signals:
 	void sampleUpdated();
 
 } ;
 
-
 #endif

include/SampleTrack.h

@@ -27,6 +27,7 @@
 
 #include <QDialog>
 #include <QLayout>
+#include <memory>
 
 #include "AudioPort.h"
 #include "FadeButton.h"
@@ -39,6 +40,7 @@
 class EffectRackView;
 class Knob;
 class SampleBuffer;
+class ControlPoint;
 class SampleTrackWindow;
 class TrackLabelButton;
 class QLineEdit;
@@ -79,6 +81,8 @@ class SampleTCO : public TrackContentObject
 	bool isPlaying() const;
 	void setIsPlaying(bool isPlaying);
 
+	void setStartTimeOffset(const TimePos &startTimeOffset) override;
+
 public slots:
 	void setSampleBuffer( SampleBuffer* sb );
 	void setSampleFile( const QString & _sf );
@@ -92,7 +96,12 @@ public slots:
 	SampleBuffer* m_sampleBuffer;
 	BoolModel m_recordModel;
 	bool m_isPlaying;
+	bool m_changed = false;
+	TimePos m_lenOld;
+	TimePos m_startTimeOffsetOld;
 
+	void saveFaderSettings(QDomElement&);
+	void loadFaderSettings(const QDomElement&);
 
 	friend class SampleTCOView;
 
@@ -116,22 +125,55 @@ class SampleTCOView : public TrackContentObjectView
 public slots:
 	void updateSample();
 	void reverseSample();
-
-
+	void setSFade();
+	void setCosFade();
+	void setLinearFade();
+	void setManualFade();
 
 protected:
 	void contextMenuEvent( QContextMenuEvent * _cme ) override;
 	void mousePressEvent( QMouseEvent * _me ) override;
 	void mouseReleaseEvent( QMouseEvent * _me ) override;
+	void mouseMoveEvent(QMouseEvent* e) override;
 	void dragEnterEvent( QDragEnterEvent * _dee ) override;
 	void dropEvent( QDropEvent * _de ) override;
 	void mouseDoubleClickEvent( QMouseEvent * ) override;
 	void paintEvent( QPaintEvent * ) override;
+	void enterEvent(QEvent *e) override;
+	void leaveEvent(QEvent *e) override;
 
 
 private:
 	SampleTCO * m_tco;
 	QPixmap m_paintPixmap;
+
+	// Members related to fading
+	bool m_moveLeftCorner = false;
+	bool m_moveRightCorner = false;
+	bool m_leftFadeClicked = false;
+	bool m_rightFadeClicked = false;
+	bool m_leftFadeManual = false;
+	bool m_rightFadeManual = false;
+	std::unique_ptr<QRectF> m_leftHandle;
+	std::unique_ptr<QRectF> m_rightHandle;
+	std::unique_ptr<QRectF> m_leftP1;
+	std::unique_ptr<QRectF> m_leftP2;
+	std::unique_ptr<QRectF> m_rightP1;
+	std::unique_ptr<QRectF> m_rightP2;
+	bool m_moveLeftP1 = false;
+	bool m_moveLeftP2 = false;
+	bool m_moveRightP1 = false;
+	bool m_moveRightP2 = false;
+	QVector<QPointF> m_leftPath;
+	QVector<QPointF> m_rightPath;
+	bool m_inside = false;
+	void drawFadePoints(bool drawLeft, QVector<QPointF>& points);
+	void drawFades();
+	void checkCornersClicked(const QMouseEvent *e);
+	void checkFadesClicked(const QMouseEvent *e);
+	void mouseMoveFadingPos(const QMouseEvent *e);
+	void mouseMoveLeftControlPoints(const QMouseEvent *e);
+	void mouseMoveRightControlPoints(const QMouseEvent *e);
 } ;
 
 

include/TrackContentObject.h

@@ -133,7 +133,7 @@ class LMMS_EXPORT TrackContentObject : public Model, public JournallingObject
 	static bool comparePosition(const TrackContentObject* a, const TrackContentObject* b);
 
 	TimePos startTimeOffset() const;
-	void setStartTimeOffset( const TimePos &startTimeOffset );
+	virtual void setStartTimeOffset(const TimePos &startTimeOffset);
 
 	void updateColor();
 

include/TrackContentObjectView.h

@@ -156,6 +156,7 @@ public slots:
 	}
 
 	float pixelsPerBar();
+	int m_textLabelHeight;
 
 
 	DataFile createTCODataFiles(const QVector<TrackContentObjectView *> & tcos) const;