implement Matrix type

add comp,eq factory methods for Matrix type

update address maps

internal/xair/matrix.go

@@ -0,0 +1,74 @@
+package xair
+
+import "fmt"
+
+type Matrix struct {
+	client      *Client
+	baseAddress string
+	Eq          *Eq
+	Comp        *Comp
+}
+
+// newMatrix creates a new Matrix instance
+func newMatrix(c *Client) *Matrix {
+	return &Matrix{
+		client:      c,
+		baseAddress: c.addressMap["matrix"],
+		Eq:          newEqForMatrix(c),
+		Comp:        newCompForMatrix(c),
+	}
+}
+
+// Fader requests the current main L/R fader level
+func (m *Matrix) Fader(index int) (float64, error) {
+	address := fmt.Sprintf(m.baseAddress, index) + "/mix/fader"
+	err := m.client.SendMessage(address)
+	if err != nil {
+		return 0, err
+	}
+
+	msg, err := m.client.ReceiveMessage()
+	if err != nil {
+		return 0, err
+	}
+	val, ok := msg.Arguments[0].(float32)
+	if !ok {
+		return 0, fmt.Errorf("unexpected argument type for matrix fader value")
+	}
+	return mustDbFrom(float64(val)), nil
+}
+
+// SetFader sets the matrix fader level
+func (m *Matrix) SetFader(index int, level float64) error {
+	address := fmt.Sprintf(m.baseAddress, index) + "/mix/fader"
+	return m.client.SendMessage(address, float32(mustDbInto(level)))
+}
+
+// Mute requests the current matrix mute status
+func (m *Matrix) Mute(index int) (bool, error) {
+	address := fmt.Sprintf(m.baseAddress, index) + "/mix/on"
+	err := m.client.SendMessage(address)
+	if err != nil {
+		return false, err
+	}
+
+	msg, err := m.client.ReceiveMessage()
+	if err != nil {
+		return false, err
+	}
+	val, ok := msg.Arguments[0].(int32)
+	if !ok {
+		return false, fmt.Errorf("unexpected argument type for matrix mute value")
+	}
+	return val == 0, nil
+}
+
+// SetMute sets the matrix mute status
+func (m *Matrix) SetMute(index int, muted bool) error {
+	address := fmt.Sprintf(m.baseAddress, index) + "/mix/on"
+	var value int32
+	if !muted {
+		value = 1
+	}
+	return m.client.SendMessage(address, value)
+}