rework tempo editing.

most changes are due to a new design where tempo discontinuities at the
beginning of a ramped section may be set.
this allows easier mapping of live performance, especially in
the common case of a ramped ritard before the beginning of a new section.

feature summary:

holding constraint modifier (shift) while dragging the BBT ruler area
drags the tempo lines by changing the start tempo (as before)

holding copy modifier (control) while dragging the BBT ruler area
drags the tempo lines by changing the end tempo (ahem. not quite there)

dragging a tempo mark while holding constraint (shift) will change the
previous end tempo to match the marker position *worth trying*.

holding constraint and copy modifier (control + shift) while dragging
the BBT ruler area attempts to'pinch' or twist the surrounding tempi
sp that later ones are not repositioned (currently suffereng from
rounding errors)

1 files changed, 25 insertions, 8 deletions

diff --git a/libs/ardour/ardour/tempo.h b/libs/ardour/ardour/tempo.h
index dd2d96e94a..c444788fdc 100644
--- a/libs/ardour/ardour/tempo.h
+++ b/libs/ardour/ardour/tempo.h
@@ -54,7 +54,9 @@ class LIBARDOUR_API Tempo {
 	 * @param type Note Type (default `4': quarter note)
 	 */
 	Tempo (double npm, double type=4.0) // defaulting to quarter note
-		: _note_types_per_minute (npm), _note_type(type) {}
+		: _note_types_per_minute (npm), _note_type (type), _end_note_types_per_minute (npm) {}
+	Tempo (double start_npm, double type, double end_npm)
+		: _note_types_per_minute (start_npm), _note_type (type), _end_note_types_per_minute (end_npm) {}
 
 	double note_types_per_minute () const { return _note_types_per_minute; }
 	double note_types_per_minute (double note_type) const { return (_note_types_per_minute / _note_type) * note_type; }
@@ -63,6 +65,14 @@ class LIBARDOUR_API Tempo {
 
 	double quarter_notes_per_minute () const { return note_types_per_minute (4.0); }
 	double pulses_per_minute () const { return note_types_per_minute (1.0); }
+
+	double end_note_types_per_minute () const { return _end_note_types_per_minute; }
+	double end_note_types_per_minute (double note_type) const { return (_end_note_types_per_minute / _note_type) * note_type; }
+	void set_end_note_types_per_minute (double npm) { _end_note_types_per_minute = npm; }
+
+	double end_quarter_notes_per_minute () const { return end_note_types_per_minute (4.0); }
+	double end_pulses_per_minute () const { return end_note_types_per_minute (1.0); }
+
 	/** audio samples per note type.
 	 * if you want an instantaneous value for this, use TempoMap::frames_per_quarter_note_at() instead.
 	 * @param sr samplerate
@@ -81,6 +91,7 @@ class LIBARDOUR_API Tempo {
   protected:
 	double _note_types_per_minute;
 	double _note_type;
+	double _end_note_types_per_minute;
 };
 
 /** Meter, or time signature (beats per bar, and which note type is a beat). */
@@ -189,8 +200,8 @@ class LIBARDOUR_API TempoSection : public MetricSection, public Tempo {
 		Constant,
 	};
 
-	TempoSection (const double& pulse, const double& minute, double qpm, double note_type, Type tempo_type, PositionLockStyle pls, framecnt_t sr)
-		: MetricSection (pulse, minute, pls, true, sr), Tempo (qpm, note_type), _type (tempo_type), _c (0.0), _active (true), _locked_to_meter (false)  {}
+	TempoSection (const double& pulse, const double& minute, Tempo tempo, Type tempo_type, PositionLockStyle pls, framecnt_t sr)
+		: MetricSection (pulse, minute, pls, true, sr), Tempo (tempo), _type (tempo_type), _c (0.0), _active (true), _locked_to_meter (false)  {}
 
 	TempoSection (const XMLNode&, const framecnt_t sample_rate);
 
@@ -226,6 +237,7 @@ class LIBARDOUR_API TempoSection : public MetricSection, public Tempo {
 	framepos_t frame_at_pulse (const double& pulse) const;
 
 	Timecode::BBT_Time legacy_bbt () { return _legacy_bbt; }
+	bool legacy_end () { return _legacy_end; }
 
   private:
 
@@ -258,6 +270,7 @@ class LIBARDOUR_API TempoSection : public MetricSection, public Tempo {
 	bool _active;
 	bool _locked_to_meter;
 	Timecode::BBT_Time _legacy_bbt;
+	bool _legacy_end;
 };
 
 typedef std::list<MetricSection*> Metrics;
@@ -329,7 +342,7 @@ class LIBARDOUR_API TempoMap : public PBD::StatefulDestructible
 
 		BBTPoint (const MeterSection& m, const Tempo& t, framepos_t f,
 		          uint32_t b, uint32_t e, double func_c)
-		: frame (f), meter (m.divisions_per_bar(), m.note_divisor()), tempo (t.note_types_per_minute(), t.note_type()), c (func_c), bar (b), beat (e) {}
+		: frame (f), meter (m.divisions_per_bar(), m.note_divisor()), tempo (t.note_types_per_minute(), t.note_type(), t.end_note_types_per_minute()), c (func_c), bar (b), beat (e) {}
 
 		Timecode::BBT_Time bbt() const { return Timecode::BBT_Time (bar, beat, 0); }
 		operator Timecode::BBT_Time() const { return bbt(); }
@@ -407,8 +420,8 @@ class LIBARDOUR_API TempoMap : public PBD::StatefulDestructible
 
 	Metrics::const_iterator metrics_end() { return _metrics.end(); }
 
-	void change_existing_tempo_at (framepos_t, double bpm, double note_type);
-	void change_initial_tempo (double bpm, double note_type);
+	void change_existing_tempo_at (framepos_t, double bpm, double note_type, double end_ntpm);
+	void change_initial_tempo (double ntpm, double note_type, double end_ntpm);
 
 	void insert_time (framepos_t, framecnt_t);
 	bool remove_time (framepos_t where, framecnt_t amount);  //returns true if anything was moved
@@ -488,14 +501,18 @@ class LIBARDOUR_API TempoMap : public PBD::StatefulDestructible
 
 	void gui_set_tempo_position (TempoSection*, const framepos_t& frame, const int& sub_num);
 	void gui_set_meter_position (MeterSection*, const framepos_t& frame);
-	bool gui_change_tempo (TempoSection*, const Tempo& bpm);
-	void gui_stretch_tempo (TempoSection* tempo, const framepos_t& frame, const framepos_t& end_frame);
+	bool gui_change_tempo (TempoSection*, const Tempo& bpm, bool change_end);
+	void gui_stretch_tempo (TempoSection* tempo, const framepos_t frame, const framepos_t end_frame);
+	void gui_stretch_tempo_end (TempoSection* tempo, const framepos_t frame, const framepos_t end_frame);
+	bool gui_twist_tempi (TempoSection* first, const Tempo& bpm, const framepos_t frame, const framepos_t end_frame);
 
 	std::pair<double, framepos_t> predict_tempo_position (TempoSection* section, const Timecode::BBT_Time& bbt);
 	bool can_solve_bbt (TempoSection* section, const Timecode::BBT_Time& bbt);
+	std::pair<double, double> ntpm_minmax () { return _ntpm_minmax; }
 
 	PBD::Signal1<void,const PBD::PropertyChange&> MetricPositionChanged;
 	void fix_legacy_session();
+	void fix_legacy_end_session();
 
 private: