change handling of MIDI gain so that we present a linear fader spanning 0..127. this is based on the realization that we actually have no idea what the MIDI receiver will do with velocity and/or CC #7 values, and so trying to pretend that we can provide some kind of dB value in the display or the behaviour of the fader is completely wrong; ALSO: fix keyboard entry of fader levels for non EN locales (#5027)

git-svn-id: svn://localhost/ardour2/branches/3.0@13480 d708f5d6-7413-0410-9779-e7cbd77b26cf

3 files changed, 54 insertions, 31 deletions

diff --git a/gtk2_ardour/gain_meter.cc b/gtk2_ardour/gain_meter.cc
index 166d29ef2c..5751d071cf 100644
--- a/gtk2_ardour/gain_meter.cc
+++ b/gtk2_ardour/gain_meter.cc
@@ -263,10 +263,10 @@ GainMeterBase::setup_gain_adjustment ()
 	} else {
 		_data_type = DataType::MIDI;
 		gain_adjustment.set_lower (0.0);
-		gain_adjustment.set_upper (2.0);
-		gain_adjustment.set_step_increment (0.05);
-		gain_adjustment.set_page_increment (0.1);
-		gain_slider->set_default_value (1);
+		gain_adjustment.set_upper (1.0);
+		gain_adjustment.set_step_increment (1.0/128.0);
+		gain_adjustment.set_page_increment (10.0/128.0);
+		gain_slider->set_default_value (1.0);
 	}
 
 	ignore_toggle = false;
@@ -396,17 +396,29 @@ GainMeterBase::gain_activated ()
 {
 	float f;
 
-	if (sscanf (gain_display.get_text().c_str(), "%f", &f) == 1) {
+	{
+		// Switch to user's preferred locale so that
+		// if they use different LC_NUMERIC conventions,
+		// we will honor them.
 
-		/* clamp to displayable values */
+		PBD::LocaleGuard lg ("");
+		if (sscanf (gain_display.get_text().c_str(), "%f", &f) != 1) {
+			return;
+		}
+	}
 
+	/* clamp to displayable values */
+	if (_data_type == DataType::AUDIO) {
 		f = min (f, 6.0f);
-
 		_amp->set_gain (dB_to_coefficient(f), this);
+	} else {
+		f = min (fabs (f), 127.0f);
+		f = Amp::midi_velocity_factor_to_gain_coefficient (f/127.0f);
+		_amp->set_gain (f, this);
+	}
 
-		if (gain_display.has_focus()) {
-			PublicEditor::instance().reset_focus();
-		}
+	if (gain_display.has_focus()) {
+		PublicEditor::instance().reset_focus();
 	}
 }
 
@@ -426,7 +438,7 @@ GainMeterBase::show_gain ()
 		}
 		break;
 	case DataType::MIDI:
-		snprintf (buf, sizeof (buf), "%.1f", v);
+		snprintf (buf, sizeof (buf), "%.0f", v * 127.0f);
 		break;
 	}
 
@@ -436,15 +448,14 @@ GainMeterBase::show_gain ()
 void
 GainMeterBase::gain_adjusted ()
 {
-	gain_t value = 0;
+	gain_t value;
 
-	switch (_data_type) {
-	case DataType::AUDIO:
+	/* convert from adjustment range (0..1) to gain coefficient */
+
+	if (_data_type == DataType::AUDIO) {
 		value = slider_position_to_gain_with_max (gain_adjustment.get_value(), Config->get_max_gain());
-		break;
-	case DataType::MIDI:
-		value = gain_adjustment.get_value ();
-		break;
+	} else {
+		value = Amp::midi_velocity_factor_to_gain_coefficient (gain_adjustment.get_value());
 	}
 	
 	if (!ignore_toggle) {
@@ -468,7 +479,7 @@ GainMeterBase::effective_gain_display ()
 		value = gain_to_slider_position_with_max (_amp->gain(), Config->get_max_gain());
 		break;
 	case DataType::MIDI:
-		value = _amp->gain ();
+		value = Amp::gain_coefficient_to_midi_velocity_factor (_amp->gain ());
 		break;
 	}
 
diff --git a/libs/ardour/amp.cc b/libs/ardour/amp.cc
index d68f73ef3e..c0cd404cf6 100644
--- a/libs/ardour/amp.cc
+++ b/libs/ardour/amp.cc
@@ -33,6 +33,10 @@
 
 using namespace ARDOUR;
 using namespace PBD;
+using std::min;
+
+/* gain range of -inf to +6dB, default 0dB */
+const float Amp::max_gain_coefficient = 1.99526231f;
 
 Amp::Amp (Session& s)
 	: Processor(s, "Amp")
@@ -42,8 +46,7 @@ Amp::Amp (Session& s)
 	, _gain_automation_buffer(0)
 {
 	Evoral::Parameter p (GainAutomation);
-	/* gain range of -inf to +6dB, default 0dB */
-	p.set_range (0, 1.99526231f, 1, false);
+	p.set_range (0, max_gain_coefficient, 1, false);
 	boost::shared_ptr<AutomationList> gl (new AutomationList (p));
 	_gain_control = boost::shared_ptr<GainControl> (new GainControl (X_("gaincontrol"), s, this, p, gl));
 	_gain_control->set_flags (Controllable::GainLike);
@@ -114,11 +117,12 @@ Amp::run (BufferSet& bufs, framepos_t /*start_frame*/, framepos_t /*end_frame*/,
 				for (BufferSet::midi_iterator i = bufs.midi_begin(); i != bufs.midi_end(); ++i) {
 
 					MidiBuffer& mb (*i);
-
+					const float midi_velocity_factor = gain_coefficient_to_midi_velocity_factor (_current_gain);
+					
 					for (MidiBuffer::iterator m = mb.begin(); m != mb.end(); ++m) {
 						Evoral::MIDIEvent<MidiBuffer::TimeType> ev = *m;
 						if (ev.is_note_on()) {
-							ev.scale_velocity (_current_gain);
+							ev.scale_velocity (midi_velocity_factor);
 						}
 					}
 				}
@@ -172,8 +176,8 @@ Amp::apply_gain (BufferSet& bufs, framecnt_t nframes, gain_t initial, gain_t tar
 			Evoral::MIDIEvent<MidiBuffer::TimeType> ev = *m;
 
 			if (ev.is_note_on()) {
-				gain_t scale = delta * (ev.time()/(double) nframes);
-				ev.scale_velocity (initial+scale);
+				const gain_t scale = delta * (ev.time()/(double) nframes);
+				ev.scale_velocity (gain_coefficient_to_midi_velocity_factor (initial+scale));
 			}
 		}
 	}
@@ -331,11 +335,12 @@ Amp::apply_simple_gain (BufferSet& bufs, framecnt_t nframes, gain_t target)
 
 		for (BufferSet::midi_iterator i = bufs.midi_begin(); i != bufs.midi_end(); ++i) {
 			MidiBuffer& mb (*i);
+			const float midi_velocity_factor = gain_coefficient_to_midi_velocity_factor (target);
 
 			for (MidiBuffer::iterator m = mb.begin(); m != mb.end(); ++m) {
 				Evoral::MIDIEvent<MidiBuffer::TimeType> ev = *m;
 				if (ev.is_note_on()) {
-					ev.scale_velocity (target);
+					ev.scale_velocity (midi_velocity_factor);
 				}
 			}
 		}
@@ -371,10 +376,7 @@ Amp::inc_gain (gain_t factor, void *src)
 void
 Amp::set_gain (gain_t val, void *src)
 {
-	// max gain at about +6dB (10.0 ^ ( 6 dB * 0.05))
-	if (val > 1.99526231f) {
-		val = 1.99526231f;
-	}
+	val = min (val, max_gain_coefficient);
 
 	if (src != _gain_control.get()) {
 		_gain_control->set_value (val);
diff --git a/libs/ardour/ardour/amp.h b/libs/ardour/ardour/amp.h
index 46dbdba227..dcffb1bcdb 100644
--- a/libs/ardour/ardour/amp.h
+++ b/libs/ardour/ardour/amp.h
@@ -102,7 +102,17 @@ public:
 	}
 
 	std::string value_as_string (boost::shared_ptr<AutomationControl>) const;
-	
+
+        static const float max_gain_coefficient;
+
+        inline static float gain_coefficient_to_midi_velocity_factor (gain_t v) { 
+		return (v/max_gain_coefficient);
+	}
+
+        inline static gain_t midi_velocity_factor_to_gain_coefficient (float v) {
+		return v * max_gain_coefficient;
+	}
+
 private:
 	bool   _denormal_protection;
 	bool   _apply_gain;