Display gain and midiNote plugin parameters/properties nicely.

Show fancy values on generic GUI controls, automation lane controls, and automation lane verbose cursor.
Fix text display of midiNote values.
Make bigstep of midiNote parameters 12 (one octave).
Add ARDOUR::value_as_string() as a stateless one-stop-shop for value printing.

1 files changed, 37 insertions, 8 deletions

diff --git a/libs/ardour/ardour/parameter_descriptor.h b/libs/ardour/ardour/parameter_descriptor.h
index 8916f081a3..1576230b8f 100644
--- a/libs/ardour/ardour/parameter_descriptor.h
+++ b/libs/ardour/ardour/parameter_descriptor.h
@@ -33,24 +33,34 @@ typedef std::map<const std::string, const float> ScalePoints;
  */
 struct ParameterDescriptor
 {
+	enum Unit {
+		NONE,       ///< No unit
+		DB,         ///< Decibels
+		MIDI_NOTE,  ///< MIDI note number
+	};
+
 	ParameterDescriptor(const Evoral::Parameter& parameter)
 		: key((uint32_t)-1)
 		, datatype(Variant::VOID)
 		, normal(parameter.normal())
 		, lower(parameter.min())
 		, upper(parameter.max())
-		, step(0)
-		, smallstep((upper - lower) / 100.0)
-		, largestep((upper - lower) / 10.0)
-		, integer_step(false)
+		, step((upper - lower) / 100.0f)
+		, smallstep((upper - lower) / 1000.0f)
+		, largestep((upper - lower) / 10.0f)
+		, integer_step(parameter.type() >= MidiCCAutomation &&
+		               parameter.type() <= MidiChannelPressureAutomation)
 		, toggled(parameter.toggled())
 		, logarithmic(false)
 		, sr_dependent(false)
 		, min_unbound(0)
 		, max_unbound(0)
 		, enumeration(false)
-		, midinote(false)
-	{}
+	{
+		if (parameter.type() == GainAutomation) {
+			unit = DB;
+		}
+	}
 
 	ParameterDescriptor()
 		: key((uint32_t)-1)
@@ -68,13 +78,33 @@ struct ParameterDescriptor
 		, min_unbound(0)
 		, max_unbound(0)
 		, enumeration(false)
-		, midinote(false)
 	{}
 
+	/// Set step, smallstep, and largestep, based on current description
+	void update_steps() {
+		if (unit == ParameterDescriptor::MIDI_NOTE) {
+			step      = smallstep = 1;  // semitone
+			largestep = 12;             // octave
+		} else {
+			const float delta = upper - lower;
+
+			step      = delta / 1000.0f;
+			smallstep = delta / 10000.0f;
+			largestep = delta / 10.0f;
+
+			if (integer_step) {
+				step      = rint(step);
+				largestep = rint(largestep);
+				// leave smallstep alone for fine tuning
+			}
+		}
+	}
+
 	std::string                    label;
 	boost::shared_ptr<ScalePoints> scale_points;
 	uint32_t                       key;  ///< for properties
 	Variant::Type                  datatype;  ///< for properties
+	Unit                           unit;
 	float                          normal;
 	float                          lower;  ///< for frequencies, this is in Hz (not a fraction of the sample rate)
 	float                          upper;  ///< for frequencies, this is in Hz (not a fraction of the sample rate)
@@ -88,7 +118,6 @@ struct ParameterDescriptor
 	bool                           min_unbound;
 	bool                           max_unbound;
 	bool                           enumeration;
-	bool                           midinote;  ///< only used if integer_step is also true
 };
 
 } // namespace ARDOUR