change VolumeController::adjust() to do discrete dB increments+decrements

git-svn-id: svn://localhost/ardour2/branches/3.0@9750 d708f5d6-7413-0410-9779-e7cbd77b26cf

2 files changed, 29 insertions, 10 deletions

diff --git a/gtk2_ardour/monitor_section.cc b/gtk2_ardour/monitor_section.cc
index ecd1e5c259..4c40a65504 100644
--- a/gtk2_ardour/monitor_section.cc
+++ b/gtk2_ardour/monitor_section.cc
@@ -70,7 +70,7 @@ MonitorSection::MonitorSection (Session* s)
 
         /* Dim */
 
-        dim_control = new VolumeController (little_knob_pixbuf, boost::shared_ptr<Controllable>(), 0.0, 0.1, 1.0, true, 30, 30, true);
+        dim_control = new VolumeController (little_knob_pixbuf, boost::shared_ptr<Controllable>(), 0.0, 0.01, 0.1, true, 30, 30, true);
 
         HBox* dim_packer = manage (new HBox);
         dim_packer->show ();
@@ -134,7 +134,7 @@ MonitorSection::MonitorSection (Session* s)
 
         /* Solo Boost */
 
-        solo_boost_control = new VolumeController (little_knob_pixbuf, boost::shared_ptr<Controllable>(), 0.0, 0.1, 1.0, true, 30, 30, true);
+        solo_boost_control = new VolumeController (little_knob_pixbuf, boost::shared_ptr<Controllable>(), 0.0, 0.01, 0.1, true, 30, 30, true);
 
         HBox* solo_packer = manage (new HBox);
         solo_packer->set_spacing (12);
@@ -151,7 +151,7 @@ MonitorSection::MonitorSection (Session* s)
 
         /* Solo (SiP) cut */
 
-        solo_cut_control = new VolumeController (little_knob_pixbuf, boost::shared_ptr<Controllable>(), 0.0, 0.1, 1.0, true, 30, 30, true);
+        solo_cut_control = new VolumeController (little_knob_pixbuf, boost::shared_ptr<Controllable>(), 0.0, 0.01, 0.1, true, 30, 30, true);
 
         spin_label = manage (new Label (_("SiP Cut")));
         spin_packer = manage (new VBox);
@@ -234,7 +234,7 @@ MonitorSection::MonitorSection (Session* s)
 
         /* Gain */
 
-        gain_control = new VolumeController (big_knob_pixbuf, boost::shared_ptr<Controllable>(), 1.0, 0.1, 1.0, true, 80, 80, false);
+        gain_control = new VolumeController (big_knob_pixbuf, boost::shared_ptr<Controllable>(), 1.0, 0.01, 0.1, true, 80, 80, false);
 
         spin_label = manage (new Label (_("Monitor")));
 	spin_packer = manage (new VBox);
diff --git a/gtk2_ardour/volume_controller.cc b/gtk2_ardour/volume_controller.cc
index 365379933d..7d6a3362de 100644
--- a/gtk2_ardour/volume_controller.cc
+++ b/gtk2_ardour/volume_controller.cc
@@ -133,11 +133,11 @@ VolumeController::to_display_value (double control_value)
 {
 	double v;
 
-//	if (_linear) {
+	if (_linear) {
 		v = (control_value - _controllable->lower ()) / (_controllable->upper() - _controllable->lower());
-//	} else {
-//		v = gain_to_slider_position_with_max (control_value, ARDOUR::Config->get_max_gain());
-//	}
+	} else {
+		v = gain_to_slider_position_with_max (control_value, ARDOUR::Config->get_max_gain());
+	}
 
 	return v;
 }
@@ -145,6 +145,25 @@ VolumeController::to_display_value (double control_value)
 double
 VolumeController::adjust (double control_delta)
 {
-	return std::max (_controllable->lower(), std::min (_controllable->upper(), _controllable->get_value() + control_delta));
-}
+	double v = _controllable->get_value ();
+	double abs_delta = fabs (control_delta);
+
+	/* convert to linear/fractional slider position domain */
+	v = gain_to_slider_position_with_max (v, ARDOUR::Config->get_max_gain());
+	/* adjust in this domain */
+	v += control_delta;
+	/* convert back to gain coefficient domain */
+	v = slider_position_to_gain_with_max (v, ARDOUR::Config->get_max_gain());
 
+	/* now round to some precision in the dB domain */
+	v = accurate_coefficient_to_dB (v);
+
+	if (abs_delta <= 0.01) {
+		v -= fmod (v, 0.05);
+	} else {
+		v -= fmod (v, 0.1);
+	} 
+
+	/* and return it */
+	return dB_to_coefficient (v);
+}