add basic start on artnet decoding

artnet.go

@@ -0,0 +1,62 @@
+package artnet
+
+import "fmt"
+
+var (
+	OpPoll             uint16 = 0x2000
+	OpPollReply        uint16 = 0x2100
+	OpDiagData         uint16 = 0x2300
+	OpCommand          uint16 = 0x2400
+	OpDataRequest      uint16 = 0x2700
+	OpDataReply        uint16 = 0x2800
+	OpOutput           uint16 = 0x5000
+	OpDmx              uint16 = 0x5000
+	OpNzs              uint16 = 0x5100
+	OpSync             uint16 = 0x5200
+	OpAddress          uint16 = 0x6000
+	OpInput            uint16 = 0x7000
+	OpTodRequest       uint16 = 0x8000
+	OpTodData          uint16 = 0x8100
+	OpTodControl       uint16 = 0x8200
+	OpRdm              uint16 = 0x8300
+	OpRdmSub           uint16 = 0x8400
+	OpVideoSetup       uint16 = 0xa010
+	OpVideoPalette     uint16 = 0xa020
+	OpVideoData        uint16 = 0xa040
+	OpMacMaster        uint16 = 0xf000
+	OpMacSlave         uint16 = 0xf100
+	OpFirmwareMaster   uint16 = 0xf200
+	OpFirmwareReply    uint16 = 0xf300
+	OpFileTnMaster     uint16 = 0xf400
+	OpFileFnMaster     uint16 = 0xf500
+	OpFileFnReply      uint16 = 0xf600
+	OpIpProg           uint16 = 0xf800
+	OpIpProgReply      uint16 = 0xf900
+	OpMedia            uint16 = 0x9000
+	OpMediaPatch       uint16 = 0x9100
+	OpMediaControl     uint16 = 0x9200
+	OpMediaContrlReply uint16 = 0x9300
+	OpTimeCode         uint16 = 0x9700
+	OpTimeSync         uint16 = 0x9800
+	OpTrigger          uint16 = 0x9900
+	OpDirectory        uint16 = 0x9a00
+	OpDirectoryReply   uint16 = 0x9b00
+)
+
+func Decode(bytes []byte) (ArtNetPacket, error) {
+	header, err := NewHeader(bytes)
+	if err != nil {
+		return nil, err
+	}
+	switch header.OpCode {
+	case OpPoll:
+		return NewArtPoll(header, bytes)
+	case OpCommand:
+		return NewArtCommand(header, bytes)
+	case OpDmx:
+		return NewArtDmx(header, bytes)
+	default:
+		return nil, fmt.Errorf("unhandled opcode: %#x", header.OpCode)
+
+	}
+}