feat(mapping): Added mapping type for rotary encoders

config/config.go

@@ -32,6 +32,7 @@ type MappingConfig struct {
 	MidiKey uint8 `yaml:"midiKey"`
 	MidiController uint8 `yaml:"midiController"`
 	Button ButtonName `yaml:"button"`
+	ButtonNegative ButtonName `yaml:"buttonNegative"`
 	Axis AxisName `yaml:"axis"`
 	IsSigned bool `yaml:"isSigned"`
 	Deadzone float64 `yaml:"deadzone"`
@@ -44,6 +45,7 @@ type AxisName string
 const (
 	ButtonMappingType MappingType = "button"
 	ControlMappingType MappingType = "control"
+	EncoderMappingType MappingType = "encoder"
 	ButtonNorth ButtonName = "north"
 	ButtonEast ButtonName = "east"
 	ButtonSouth ButtonName = "south"
@@ -134,6 +136,20 @@ func (mc MappingConfig) Construct() (translation.Mapping, error) {
 		log.Debug("Parsed button mapping", "comment", mc.Comment, "midiChannel", mc.MidiChannel, "midiKey", mc.MidiKey, "button", button)
 
 		return translation.ButtonMapping{mc.Comment, mc.MidiChannel, mc.MidiKey, button}, nil
+	case EncoderMappingType:
+		button, err := mc.Button.Construct()
+		if err != nil {
+			return translation.EncoderMapping{}, err
+		}
+
+		buttonNegative, err := mc.ButtonNegative.Construct()
+		if err != nil {
+			return translation.EncoderMapping{}, err
+		}
+
+		log.Debug("Parsed encoder mapping", "comment", mc.Comment, "midiChannel", mc.MidiChannel, "midiController", mc.MidiController, "button", button, "buttonNegative", buttonNegative)
+
+		return translation.EncoderMapping{mc.Comment, mc.MidiChannel, mc.MidiController, button, buttonNegative}, nil
 	case ControlMappingType:
 		axis, err := mc.Axis.Construct()
 		if err != nil {

translation/mapping.go

@@ -65,6 +65,53 @@ func (m ButtonMapping) Comment() string {
 	return m.CommentStr
 }
 
+// An EncoderMapping maps a MIDI Controller to two buttons.
+type EncoderMapping struct {
+	CommentStr string
+	MidiChannel uint8
+	MidiController uint8
+	GamepadKeyPositive int
+	GamepadKeyNegative int
+}
+
+// Is checks if the MIDI message msg triggers this Mapping, without actually triggering it.
+func (m EncoderMapping) Is(msg midi.Message) bool {
+	var channel, controller uint8
+
+	if msg.GetControlChange(&channel, &controller, nil) {
+		return (m.MidiChannel == channel && m.MidiController == controller)
+	} else {
+		return false
+	}
+}
+
+// TriggerIfMatch checks if the MIDI message msg triggers this Mapping, and if so,
+// sends the corresponding input to virtGamepad.
+func (m EncoderMapping) TriggerIfMatch(msg midi.Message, virtGamepad uinput.Gamepad) error {
+	if m.Is(msg) {
+		var valueAbsolute uint8
+
+		msg.GetControlChange(nil, nil, &valueAbsolute)
+		
+		switch valueAbsolute {
+		case 1:
+			log.Debug(m.CommentStr, "status", "increased")
+			return virtGamepad.ButtonPress(m.GamepadKeyPositive)
+		case 127:
+			log.Debug(m.CommentStr, "status", "decreased")
+			return virtGamepad.ButtonPress(m.GamepadKeyNegative)
+		default:
+			return fmt.Errorf("Invalid message type triggered ButtonMapping")
+		}
+	}
+
+	return nil
+}
+
+// Comment returns the Mappings comment.
+func (m EncoderMapping) Comment() string {
+	return m.CommentStr
+}
 type ControllerAxis int
 
 const (