Format boolean parameter values

libs/ardour/ardour/value_as_string.h

@@ -26,6 +26,8 @@
 #include "ardour/dB.h"
 #include "ardour/parameter_descriptor.h"
 
+#include "pbd/i18n.h"
+
 namespace ARDOUR {
 
 inline std::string
@@ -45,6 +47,10 @@ value_as_string(const ARDOUR::ParameterDescriptor& desc,
 		}
 	}
 
+	if (desc.toggled) {
+		return v >= 0 ? _("on") : _("off");
+	}
+
 	// Value is not a scale point, print it normally
 	if (desc.unit == ARDOUR::ParameterDescriptor::MIDI_NOTE) {
 		snprintf(buf, sizeof(buf), "%s", ParameterDescriptor::midi_note_name (rint(v)).c_str());