refactored fader levels and mute state

1 files changed, 59 insertions, 17 deletions

diff --git a/pkg/mixer/mixer.go b/pkg/mixer/mixer.go
index 4db2c3a..a3348d9 100644
--- a/pkg/mixer/mixer.go
+++ b/pkg/mixer/mixer.go
@@ -32,9 +32,13 @@ import (
 	"github.com/scgolang/midi"
 )
 
-type Channel uint8
-type FaderLevel uint8
+// TODO: make this configurable
+const (
+	CC_MUTE  = byte(0xB1)
+	CC_FADER = byte(0xB0)
+)
 
+type Channel uint8
 type EventType int
 
 const (
@@ -53,14 +57,61 @@ func (et EventType) String() string {
 	}
 }
 
+type FaderLevel uint8
+
+// TODO: make the values configurable
+const (
+	FaderLevelUnknown = FaderLevel(0xFF)
+	FaderLevelMax     = FaderLevel(0x7F)
+	FaderLevel0db     = FaderLevel(0x5F)
+	FaderLevelOff     = FaderLevel(0x00)
+)
+
+func (fl FaderLevel) String() string {
+	if fl > FaderLevelMax {
+		return "unknown"
+	}
+	val := fmt.Sprintf("%3d", fl)
+	switch fl {
+	case FaderLevelMax:
+		return val + " (max)"
+	case FaderLevel0db:
+		return val + " (0db)"
+	case FaderLevelOff:
+		return val + " (off)"
+	default:
+		return val
+	}
+}
+
+type Mute int8
+
+const (
+	MuteUnknown = -1
+	MuteUnmuted = 0
+	MuteMuted   = 1
+)
+
+func (m Mute) String() string {
+	switch m {
+	case MuteUnmuted:
+		return "unmuted"
+	case MuteMuted:
+		return "muted"
+	default:
+		return "unknown"
+	}
+}
+
 type Event struct {
 	Channel Channel
 	Type    EventType
-	Value   uint8
+	Level   FaderLevel
+	Mute    Mute
 }
 
 func (e Event) String() string {
-	return fmt.Sprintf("Event(%s) for channel 0x%02X, value=%d", e.Type, e.Channel, e.Value)
+	return fmt.Sprintf("Event(%s) for channel %d: level=%s, muted=%s", e.Type, e.Channel, e.Level, e.Mute)
 }
 
 type Mixer struct {
@@ -69,16 +120,6 @@ type Mixer struct {
 	subscribers map[Channel]*list.List
 }
 
-// TODO: make this configurable
-const (
-	CC_MUTE  = byte(0xB1)
-	CC_FADER = byte(0xB0)
-
-	FaderLevelMax = FaderLevel(0x7F)
-	FaderLevel0db = FaderLevel(0x60)
-	FaderLevelOff = FaderLevel(0x00)
-)
-
 func openDevice(devices []*midi.Device, prefix string) (d *midi.Device, err error) {
 	for _, device := range devices {
 		if strings.HasPrefix(device.Name, prefix) {
@@ -136,16 +177,17 @@ func (m *Mixer) sendEvent(ev Event) {
 }
 
 func (m *Mixer) handleMidiPacket(p midi.Packet) {
-	ev := Event{}
+	ev := Event{Level: FaderLevelUnknown, Mute: MuteUnknown}
 	ev.Channel = Channel(p.Data[1])
 	switch p.Data[0] {
 	case CC_FADER:
 		ev.Type = EventFaderChange
-		ev.Value = p.Data[2]
+		ev.Level = FaderLevel(p.Data[2])
 	case CC_MUTE:
 		ev.Type = EventMute
+		ev.Mute = MuteUnmuted
 		if p.Data[2] > 0 {
-			ev.Value = 1
+			ev.Mute = MuteMuted
 		}
 	default:
 		return