Update to 1.16.3 + add a few new event callbacks.

README.md

@@ -1,6 +1,6 @@
 # Go-MC
-![Version](https://img.shields.io/badge/Minecraft-1.16.2-blue.svg)
+![Version](https://img.shields.io/badge/Minecraft-1.16.3-blue.svg)
-![Protocol](https://img.shields.io/badge/Protocol-751-blue.svg)
+![Protocol](https://img.shields.io/badge/Protocol-753-blue.svg)
 [![GoDoc](https://godoc.org/github.com/Tnze/go-mc?status.svg)](https://godoc.org/github.com/Tnze/go-mc)
 [![Go Report Card](https://goreportcard.com/badge/github.com/Tnze/go-mc)](https://goreportcard.com/report/github.com/Tnze/go-mc)
 [![Build Status](https://travis-ci.org/Tnze/go-mc.svg?branch=master)](https://travis-ci.org/Tnze/go-mc)
@@ -105,4 +105,4 @@ Originally it's all right to write a bot with only `go-mc/net` package. But cons
 
 理论上讲，只用`go-mc/net`包实现一个bot是完全可行的，但是为了节省大家从头去理解MC握手、登录、加密等协议的过程，在`go-mc/bot`中我已经把这些都实现了，只不过它不是跨版本的。你可以直接使用，或者作为自己实现的参考。
 
-Now, go and have a look at the example! 
+Now, go and have a look at the example!

bot/client.go

@@ -14,6 +14,7 @@ type Client struct {
 
 	player.Player
 	PlayInfo
+	ServInfo
 	abilities PlayerAbilities
 	settings  Settings
 	Wd        world.World //the map data
@@ -49,16 +50,21 @@ func NewClient() (c *Client) {
 
 //PlayInfo content player info in server.
 type PlayInfo struct {
-	Gamemode         int    //游戏模式
+	Gamemode         int      //游戏模式
-	Hardcore         bool   //是否是极限模式
+	Hardcore         bool     //是否是极限模式
-	Dimension        int    //维度
+	Dimension        int      //维度
-	Difficulty       int    //难度
+	Difficulty       int      //难度
-	ViewDistance     int    //视距
+	ViewDistance     int      //视距
-	ReducedDebugInfo bool   //减少调试信息
+	ReducedDebugInfo bool     //减少调试信息
-	WorldName        string //当前世界的名字
+	WorldName        string   //当前世界的名字
-	IsDebug          bool   //调试
+	IsDebug          bool     //调试
-	IsFlat           bool   //超平坦世界
+	IsFlat           bool     //超平坦世界
-	// SpawnPosition    Position //主世界出生点
+	SpawnPosition    Position //主世界出生点
+}
+
+// ServInfo contains information about the server implementation.
+type ServInfo struct {
+	Brand string
 }
 
 // PlayerAbilities defines what player can do.

bot/event.go

@@ -8,7 +8,30 @@ import (
 	pk "github.com/Tnze/go-mc/net/packet"
 )
 
+type seenPacketFlags uint8
+
+// Valid seenPacketFlags values.
+const (
+	seenJoinGame seenPacketFlags = 1 << iota
+	seenServerDifficulty
+	seenPlayerAbilities
+	seenPlayerInventory
+	seenUpdateLight
+	seenChunkData
+	seenPlayerPositionAndLook
+	seenSpawnPos
+
+	// gameReadyMinPackets are the minimum set of packets that must be seen, for
+	// the GameReady callback to be invoked.
+	gameReadyMinPackets = seenJoinGame | seenChunkData | seenUpdateLight |
+		seenPlayerAbilities | seenPlayerInventory | seenServerDifficulty |
+		seenPlayerPositionAndLook | seenSpawnPos
+)
+
 type eventBroker struct {
+	seenPackets seenPacketFlags
+	isReady     bool
+
 	GameStart      func() error
 	ChatMsg        func(msg chat.Message, pos byte, sender uuid.UUID) error
 	Disconnect     func(reason chat.Message) error
@@ -28,7 +51,29 @@ type eventBroker struct {
 	WindowsItem       func(id byte, slots []entity.Slot) error
 	WindowsItemChange func(id byte, slotID int, slot entity.Slot) error
 
-	// ReceivePacket will be called when new packet arrive.
+	// ServerDifficultyChange is called whenever the gamemode of the server changes.
-	// Default handler will run only if pass == false.
+	// At time of writing (1.16.3), difficulty values of 0, 1, 2, and 3 correspond
+	// to peaceful, easy, normal, and hard respectively.
+	ServerDifficultyChange func(difficulty int) error
+
+	// GameReady is called after the client has joined the server and successfully
+	// received player state. Additionally, the server has begun sending world
+	// state (such as lighting and chunk information).
+	//
+	// Use this callback as a signal as to when your bot should start 'doing'
+	// things.
+	GameReady func() error
+
+	// ReceivePacket will be called when new packets arrive.
+	// The default handler will run only if pass == false.
 	ReceivePacket func(p pk.Packet) (pass bool, err error)
 }
+
+func (b *eventBroker) updateSeenPackets(f seenPacketFlags) error {
+	b.seenPackets |= f
+	if (^b.seenPackets)&gameReadyMinPackets == 0 && b.GameReady != nil && !b.isReady {
+		b.isReady = true
+		return b.GameReady()
+	}
+	return nil
+}

bot/ingame.go

@@ -71,12 +71,33 @@ func (c *Client) handlePacket(p pk.Packet) (disconnect bool, err error) {
 		if err == nil && c.Events.GameStart != nil {
 			err = c.Events.GameStart()
 		}
+
+		_ = c.conn.WritePacket(
+			//PluginMessage packet (serverbound) - sending minecraft brand.
+			pk.Marshal(
+				data.PluginMessageServerbound,
+				pk.Identifier("minecraft:brand"),
+				pk.String(c.settings.Brand),
+			),
+		)
+		if err2 := c.Events.updateSeenPackets(seenJoinGame); err == nil {
+			err = err2
+		}
 	case data.PluginMessageClientbound:
 		err = handlePluginPacket(c, p)
 	case data.ServerDifficulty:
 		err = handleServerDifficultyPacket(c, p)
+		if err == nil && c.Events.ServerDifficultyChange != nil {
+			err = c.Events.ServerDifficultyChange(c.Difficulty)
+		}
+		if err2 := c.Events.updateSeenPackets(seenServerDifficulty); err == nil {
+			err = err2
+		}
 	case data.SpawnPosition:
 		err = handleSpawnPositionPacket(c, p)
+		if err2 := c.Events.updateSeenPackets(seenSpawnPos); err == nil {
+			err = err2
+		}
 	case data.PlayerAbilitiesClientbound:
 		err = handlePlayerAbilitiesPacket(c, p)
 		_ = c.conn.WritePacket(
@@ -91,13 +112,24 @@ func (c *Client) handlePacket(p pk.Packet) (disconnect bool, err error) {
 				pk.VarInt(c.settings.MainHand),
 			),
 		)
+		if err2 := c.Events.updateSeenPackets(seenPlayerAbilities); err == nil {
+			err = err2
+		}
 	case data.HeldItemChangeClientbound:
 		err = handleHeldItemPacket(c, p)
+	case data.UpdateLight:
+		err = c.Events.updateSeenPackets(seenUpdateLight)
 	case data.ChunkData:
 		err = handleChunkDataPacket(c, p)
+		if err2 := c.Events.updateSeenPackets(seenChunkData); err == nil {
+			err = err2
+		}
 	case data.PlayerPositionAndLookClientbound:
 		err = handlePlayerPositionAndLookPacket(c, p)
 		sendPlayerPositionAndLookPacket(c) // to confirm the position
+		if err2 := c.Events.updateSeenPackets(seenPlayerPositionAndLook); err == nil {
+			err = err2
+		}
 	case data.DeclareRecipes:
 		// handleDeclareRecipesPacket(g, reader)
 	case data.EntityLookAndRelativeMove:
@@ -395,6 +427,16 @@ func handlePluginPacket(c *Client, p pk.Packet) error {
 	if err := p.Scan(&Channel, &Data); err != nil {
 		return err
 	}
+
+	switch Channel {
+	case "minecraft:brand":
+		var brandRaw pk.String
+		if err := brandRaw.Decode(bytes.NewReader(Data)); err != nil {
+			return err
+		}
+		c.ServInfo.Brand = string(brandRaw)
+	}
+
 	if c.Events.PluginMessage != nil {
 		return c.Events.PluginMessage(string(Channel), []byte(Data))
 	}
@@ -417,8 +459,8 @@ func handleSpawnPositionPacket(c *Client, p pk.Packet) error {
 	if err != nil {
 		return err
 	}
-	// c.SpawnPosition.X, c.SpawnPosition.Y, c.SpawnPosition.Z =
+	c.SpawnPosition.X, c.SpawnPosition.Y, c.SpawnPosition.Z =
-	// 	pos.X, pos.Y, pos.Z
+		pos.X, pos.Y, pos.Z
 	return nil
 }
 
@@ -598,11 +640,7 @@ func handleKeepAlivePacket(c *Client, p pk.Packet) error {
 	))
 }
 
-func handleWindowItemsPacket(c *Client, p pk.Packet) (err error) {
+func handleWindowItemsPacket(c *Client, p pk.Packet) error {
-	if c.Events.WindowsItem == nil {
-		return nil
-	}
-
 	r := bytes.NewReader(p.Data)
 	var (
 		windowID pk.Byte
@@ -623,6 +661,14 @@ func handleWindowItemsPacket(c *Client, p pk.Packet) (err error) {
 		slots = append(slots, slot)
 	}
 
+	if windowID == 0 { // Window ID 0 is the players' inventory.
+		if err := c.Events.updateSeenPackets(seenPlayerInventory); err != nil {
+			return err
+		}
+	}
+	if c.Events.WindowsItem == nil {
+		return nil
+	}
 	return c.Events.WindowsItem(byte(windowID), slots)
 }
 

bot/mcbot.go

@@ -14,7 +14,7 @@ import (
 )
 
 // ProtocolVersion , the protocol version number of minecraft net protocol
-const ProtocolVersion = 751
+const ProtocolVersion = 753
 
 // JoinServer connect a Minecraft server for playing the game.
 func (c *Client) JoinServer(addr string, port int) (err error) {

bot/settings.go

@@ -9,6 +9,7 @@ type Settings struct {
 	DisplayedSkinParts uint8  //皮肤显示
 	MainHand           int    //主手
 	ReceiveMap         bool   //接收地图数据
+	Brand              string // The brand string presented to the server.
 }
 
 /*
@@ -33,4 +34,5 @@ var DefaultSettings = Settings{
 	DisplayedSkinParts: Jacket | LeftSleeve | RightSleeve | LeftPantsLeg | RightPantsLeg | Hat,
 	MainHand:           1,
 	ReceiveMap:         true,
+	Brand:              "vanilla",
 }