switch to unmarshal marshal

dmx.go

@@ -1,49 +1,85 @@
 package artnet
 
 import (
+	"encoding/binary"
 	"errors"
+	"slices"
 )
 
 type ArtDmx struct {
-	Header   *ArtNetHeader
-	Sequence uint8
-	Physical uint8
-	SubUni   uint8
-	Net      uint8
-	Length   uint16
-	Data     []uint8
+	ID        []uint8
+	OpCode    uint16
+	ProtVerHi uint8
+	ProtVerLo uint8
+	Sequence  uint8
+	Physical  uint8
+	SubUni    uint8
+	Net       uint8
+	Length    uint16
+	Data      []uint8
 }
 
-func NewArtDmx(header *ArtNetHeader, data []byte) (*ArtDmx, error) {
-	artDmx := ArtDmx{
-		Header: header,
+func NewArtDmx(data []byte) (*ArtDmx, error) {
+	artDmx := ArtDmx{}
+
+	err := artDmx.UnmarshalBinary(data)
+
+	if err != nil {
+		return nil, err
 	}
 
-	if len(data) < 18 {
-		return nil, errors.New("ArtDmx packet must be at least 14 bytes long")
-	}
-	offset := 12
-
-	artDmx.Sequence = data[offset]
-	artDmx.Physical = data[offset+1]
-	artDmx.SubUni = data[offset+2]
-	artDmx.Net = data[offset+3]
-
-	artDmx.Length = uint16(data[offset+4])<<8 + uint16(data[offset+5])
-
-	dmxDataOffset := offset + 6
-
-	if len(data[dmxDataOffset:]) < int(artDmx.Length) {
-		return nil, errors.New("ArtDmx packet length mismatch")
-	}
-
-	artDmx.Data = make([]uint8, artDmx.Length)
-
-	copy(artDmx.Data, data[dmxDataOffset:dmxDataOffset+int(artDmx.Length)])
-
 	return &artDmx, nil
 }
 
-func (ap *ArtDmx) GetOpCode() uint16 {
-	return ap.Header.OpCode
+func (ad *ArtDmx) GetOpCode() uint16 {
+	return ad.OpCode
+}
+
+func (ad *ArtDmx) GetProtVer() uint16 {
+	return uint16(ad.ProtVerHi)<<8 + uint16(ad.ProtVerLo)
+}
+
+func (ad *ArtDmx) GetID() []uint8 {
+	return ad.ID
+}
+
+func (ad *ArtDmx) UnmarshalBinary(data []byte) error {
+	if len(data) < 18 {
+		return errors.New("ArtDmx packet must be at least 18 bytes long")
+	}
+
+	if !slices.Equal(ArtNetID, data[0:8]) {
+		return errors.New("ID does not match Art-Net ID")
+	}
+
+	ad.OpCode = binary.LittleEndian.Uint16(data[8:10])
+	ad.ProtVerHi = data[10]
+	ad.ProtVerLo = data[11]
+
+	offset := 12
+
+	ad.Sequence = data[offset]
+	ad.Physical = data[offset+1]
+	ad.SubUni = data[offset+2]
+	ad.Net = data[offset+3]
+
+	ad.Length = uint16(data[offset+4])<<8 + uint16(data[offset+5])
+
+	dmxDataOffset := offset + 6
+
+	if len(data[dmxDataOffset:]) < int(ad.Length) {
+		return errors.New("ArtDmx packet length mismatch")
+	}
+
+	ad.Data = make([]uint8, ad.Length)
+
+	copy(ad.Data, data[dmxDataOffset:dmxDataOffset+int(ad.Length)])
+	return nil
+}
+
+func (ad *ArtDmx) MarshalBinary() ([]byte, error) {
+	data := []byte(ArtNetID)
+	data = append(data, byte(ad.OpCode), byte(ad.OpCode>>8), ad.ProtVerHi, ad.ProtVerLo, ad.Sequence, ad.Physical, ad.SubUni, ad.Net, byte(ad.Length>>8), byte(ad.Length))
+	data = append(data, ad.Data...)
+	return data, nil
 }