From ab6ab082dd947a1a79fcc704968a6d1dc7701b66 Mon Sep 17 00:00:00 2001
From: Paul Davis <paul@linuxaudiosystems.com>
Date: Fri, 4 Aug 2017 18:09:31 -0400
Subject: [PATCH] add tempo adjustment

---
 tools/bb/bb.cc  | 38 +++++++++++++++++++++++++++++---------
 tools/bb/bb.h   |  4 ++++
 tools/bb/gui.cc | 13 +++++++++++++
 tools/bb/gui.h  |  5 +++++
 4 files changed, 51 insertions(+), 9 deletions(-)

diff --git a/tools/bb/bb.cc b/tools/bb/bb.cc
index 0689b513f2..668630c0f9 100644
--- a/tools/bb/bb.cc
+++ b/tools/bb/bb.cc
@@ -144,6 +144,7 @@ BeatBox::BeatBox (int sr)
 	, _running (false)
 	, _measures (2)
 	, _tempo (120)
+	, _tempo_request (0)
 	, _meter_beats (4)
 	, _meter_beat_type (4)
 	, _input (0)
@@ -182,20 +183,20 @@ BeatBox::register_ports (jack_client_t* jack)
 	return 0;
 }
 
+void
+BeatBox::compute_tempo_clocks ()
+{
+	whole_note_superclocks = (superclock_ticks_per_second * 60) / (_tempo / _meter_beat_type);
+	beat_superclocks = whole_note_superclocks / _meter_beat_type;
+	measure_superclocks = beat_superclocks * _meter_beats;
+}
+
 void
 BeatBox::start ()
 {
 	/* compute tempo, beat steps etc. */
 
-	/*
-	   superclocks_per_minute = superclock_ticks_per_second * 60;
-	   beats_per_minute = _tempo;
-	   whole_notes_per_minute = beats_per_minute / _meter_beat_type;
-	*/
-
-	whole_note_superclocks = (superclock_ticks_per_second * 60) / (_tempo / _meter_beat_type);
-	beat_superclocks = whole_note_superclocks / _meter_beat_type;
-	measure_superclocks = beat_superclocks * _meter_beats;
+	compute_tempo_clocks ();
 
 	/* we can start */
 
@@ -208,6 +209,12 @@ BeatBox::stop ()
 	_start_requested = false;
 }
 
+void
+BeatBox::set_tempo (float bpm)
+{
+	_tempo_request = bpm;
+}
+
 int
 BeatBox::process (int nsamples)
 {
@@ -230,6 +237,18 @@ BeatBox::process (int nsamples)
 		return 0;
 	}
 
+	if (_tempo_request) {
+		double ratio = _tempo / _tempo_request;
+		_tempo = _tempo_request;
+		_tempo_request = 0;
+
+		compute_tempo_clocks ();
+
+		for (Events::iterator ee = _current_events.begin(); ee != _current_events.end(); ++ee) {
+			(*ee)->time = llrintf ((*ee)->time * ratio);
+		}
+	}
+
 	superclock_t process_start = superclock_cnt - last_start;
 	superclock_t process_end = process_start + superclocks;
 	const superclock_t loop_length = _measures * measure_superclocks;
@@ -324,6 +343,7 @@ BeatBox::process (int nsamples)
 		event_pool.pop_back ();
 
 		e->time = quantized_time;
+		e->whole_note_superclocks = whole_note_superclocks;
 		e->size = in_event.size;
 		memcpy (e->buf, in_event.buffer, in_event.size);
 
diff --git a/tools/bb/bb.h b/tools/bb/bb.h
index e16b9360a8..79a24d6929 100644
--- a/tools/bb/bb.h
+++ b/tools/bb/bb.h
@@ -44,6 +44,7 @@ class BeatBox {
 	bool _running;
 	int   _measures;
 	float _tempo;
+	float _tempo_request;
 	int   _meter_beats;
 	int   _meter_beat_type;
 	jack_port_t* _input;
@@ -60,6 +61,7 @@ class BeatBox {
 
 	struct Event {
 		superclock_t time;
+		superclock_t whole_note_superclocks;
 		size_t       size;
 		unsigned char  buf[24];
 
@@ -77,6 +79,8 @@ class BeatBox {
 
 	typedef std::vector<Event*> EventPool;
 	EventPool  event_pool;
+
+	void compute_tempo_clocks ();
 };
 
 
diff --git a/tools/bb/gui.cc b/tools/bb/gui.cc
index cdb34eb124..0bb894e3c2 100644
--- a/tools/bb/gui.cc
+++ b/tools/bb/gui.cc
@@ -14,6 +14,8 @@ BBGUI::BBGUI (int* argc, char** argv[], jack_client_t* j, BeatBox* bb)
 	, quantize_whole (quantize_group, "Whole")
 	, play_button ("Run")
 	, clear_button ("Clear")
+	, tempo_adjustment (bb->tempo(), 1, 300, 1, 10)
+	, tempo_spinner (tempo_adjustment)
 {
 	quantize_off.signal_toggled().connect (sigc::bind (sigc::mem_fun (*this, &BBGUI::set_quantize), 0));
 	quantize_32nd.signal_toggled().connect (sigc::bind (sigc::mem_fun (*this, &BBGUI::set_quantize), 32));
@@ -37,6 +39,10 @@ BBGUI::BBGUI (int* argc, char** argv[], jack_client_t* j, BeatBox* bb)
 	misc_button_box.pack_start (play_button);
 	misc_button_box.pack_start (clear_button);
 
+	tempo_adjustment.signal_value_changed().connect (sigc::mem_fun (*this, &BBGUI::tempo_changed));
+
+	misc_button_box.pack_start (tempo_spinner);
+
 	global_vbox.pack_start (misc_button_box);
 	global_vbox.pack_start (quantize_button_box, true, true);
 	window.add (global_vbox);
@@ -54,6 +60,13 @@ BBGUI::run ()
 	main.run ();
 }
 
+void
+BBGUI::tempo_changed ()
+{
+	float t = tempo_adjustment.get_value();
+	bbox->set_tempo (t);
+}
+
 void
 BBGUI::set_quantize (int divisor)
 {
diff --git a/tools/bb/gui.h b/tools/bb/gui.h
index d3d9dc5e00..4c08d5e4ab 100644
--- a/tools/bb/gui.h
+++ b/tools/bb/gui.h
@@ -31,13 +31,18 @@ class BBGUI {
 	Gtk::ToggleButton play_button;
 	Gtk::Button clear_button;
 
+	Gtk::Adjustment tempo_adjustment;
+	Gtk::SpinButton tempo_spinner;
+
 	Gtk::VBox global_vbox;
 	Gtk::VBox quantize_button_box;
 	Gtk::HBox misc_button_box;
 
+
 	void set_quantize (int divisor);
 	void toggle_play ();
 	void clear ();
+	void tempo_changed ();
 };
 
 #endif /* __bb_gui_h__ */