give MIDI tracks a (n automatable) velocity control

libs/ardour/ardour/midi_track.h

@@ -34,6 +34,7 @@ class MidiPlaylist;
 class RouteGroup;
 class SMFSource;
 class Session;
+class VelocityControl;
 
 class LIBARDOUR_API MidiTrack : public Track
 {
@@ -75,6 +76,8 @@ public:
 	void midi_panic(void);
 	bool write_immediate_event (Evoral::EventType event_type, size_t size, const uint8_t* buf);
 
+	boost::shared_ptr<VelocityControl> velocity_control() const;
+
 	/** A control that will send "immediate" events to a MIDI track when twiddled */
 	struct MidiControl : public AutomationControl {
 		MidiControl(MidiTrack* route, const Evoral::Parameter& param,
@@ -166,6 +169,8 @@ private:
 	MidiChannelFilter           _playback_filter;
 	MidiChannelFilter           _capture_filter;
 
+	boost::shared_ptr<VelocityControl>  _velocity_control;
+
 	void set_state_part_two ();
 	void set_state_part_three ();
 

libs/ardour/ardour/types.h

@@ -175,6 +175,7 @@ enum AutomationType {
 	BusSendEnable,
 	InsertReturnLevel,
 	MainOutVolume,
+	MidiVelocityAutomation,
 
 	/* used only by Controllable Descriptor to access send parameters */
 

libs/ardour/ardour/velocity_control.h

@@ -0,0 +1,44 @@
+/*
+ * Copyright (C) 2022 Paul Davis <paul@linuxaudiosystems.com>
+ *
+ * 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; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef __ardour_velocity_control_h__
+#define __ardour_velocity_control_h__
+
+#include <string>
+
+#include <boost/shared_ptr.hpp>
+
+#include "pbd/controllable.h"
+
+#include "evoral/Parameter.h"
+
+#include "ardour/slavable_automation_control.h"
+#include "ardour/libardour_visibility.h"
+
+namespace ARDOUR {
+
+class Session;
+
+class LIBARDOUR_API VelocityControl : public SlavableAutomationControl {
+  public:
+	VelocityControl (Session& session);
+};
+
+} /* namespace */
+
+#endif /* __ardour_velocity_control_h__ */

libs/ardour/automation_list.cc

@@ -166,6 +166,7 @@ AutomationList::create_curve_if_necessary()
 	case FadeInAutomation:
 	case FadeOutAutomation:
 	case EnvelopeAutomation:
+	case MidiVelocityAutomation:
 		create_curve();
 		break;
 	default:

libs/ardour/enums.cc

@@ -208,6 +208,7 @@ setup_enum_writer ()
 	REGISTER_ENUM (BusSendEnable);
 	REGISTER_ENUM (InsertReturnLevel);
 	REGISTER_ENUM (MainOutVolume);
+	REGISTER_ENUM (MidiVelocityAutomation);
 	REGISTER (_AutomationType);
 
 	REGISTER_ENUM (Off);

libs/ardour/midi_track.cc

@@ -64,6 +64,7 @@
 #include "ardour/session_playlists.h"
 #include "ardour/types_convert.h"
 #include "ardour/utils.h"
+#include "ardour/velocity_control.h"
 
 #include "pbd/i18n.h"
 
@@ -108,6 +109,9 @@ MidiTrack::init ()
 		return -1;
 	}
 
+	_velocity_control.reset (new VelocityControl (_session));
+	add_control (_velocity_control);
+
 	_input->changed.connect_same_thread (*this, boost::bind (&MidiTrack::track_input_active, this, _1, _2));
 
 	_disk_writer->set_note_mode (_note_mode);

libs/ardour/velocity_control.cc

@@ -0,0 +1,38 @@
+/*
+ * Copyright (C) 2022 Paul Davis <paul@linuxaudiosystems.com>
+ *
+ * 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; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include <cmath>
+
+#include "pbd/convert.h"
+#include "pbd/strsplit.h"
+
+#include "ardour/velocity_control.h"
+#include "ardour/session.h"
+
+#include "pbd/i18n.h"
+
+using namespace ARDOUR;
+using namespace std;
+
+
+VelocityControl::VelocityControl (Session& session)
+	: SlavableAutomationControl (session, Evoral::Parameter (MidiVelocityAutomation), ParameterDescriptor (Evoral::Parameter (MidiVelocityAutomation)),
+	                             boost::shared_ptr<AutomationList> (new AutomationList (Evoral::Parameter (MidiVelocityAutomation), Temporal::BeatTime)),
+	                             _("Velocity"))
+{
+}

libs/ardour/wscript

@@ -278,6 +278,7 @@ libardour_sources = [
         'utils.cc',
         'vca.cc',
         'vca_manager.cc',
+        'velocity_control.cc',
         'video_tools_paths.cc',
         'vumeterdsp.cc',
         'worker.cc',