Merge pull request #84 from twitchyliquid64/master

Massive update

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)

bot/client.go

@@ -1,10 +1,18 @@
 package bot
 
 import (
+	"sync"
+	"time"
+
+	"github.com/Tnze/go-mc/bot/path"
+	"github.com/Tnze/go-mc/bot/phy"
 	"github.com/Tnze/go-mc/bot/world"
 	"github.com/Tnze/go-mc/bot/world/entity"
 	"github.com/Tnze/go-mc/bot/world/entity/player"
+	"github.com/Tnze/go-mc/data"
 	"github.com/Tnze/go-mc/net"
+	"github.com/Tnze/go-mc/net/packet"
+	pk "github.com/Tnze/go-mc/net/packet"
 )
 
 // Client is used to access Minecraft server
@@ -14,14 +22,35 @@ type Client struct {
 
 	player.Player
 	PlayInfo
+	ServInfo
 	abilities PlayerAbilities
 	settings  Settings
-	Wd        world.World //the map data
+
+	Wd             world.World //the map data
+	Inputs         path.Inputs
+	Physics        phy.State
+	lastPosTx      time.Time
+	justTeleported bool
 
 	// Delegate allows you push a function to let HandleGame run.
 	// Do not send at the same goroutine!
 	Delegate chan func() error
 	Events   eventBroker
+
+	closing chan struct{}
+	inbound chan pk.Packet
+	wg      sync.WaitGroup
+}
+
+func (c *Client) Close() error {
+	close(c.closing)
+	err := c.disconnect()
+	c.wg.Wait()
+	return err
+}
+
+func (c *Client) SendCloseWindow(windowID byte) error {
+	return c.conn.WritePacket(packet.Marshal(data.CloseWindowServerbound, pk.UnsignedByte(windowID)))
 }
 
 // NewClient init and return a new Client.
@@ -31,34 +60,37 @@ type Client struct {
 //
 // For online-mode, you need login your Mojang account
 // and load your Name, UUID and AccessToken to client.
-func NewClient() (c *Client) {
+func NewClient() *Client {
-	c = new(Client)
+	return &Client{
-
+		settings: DefaultSettings,
-	//init Client
+		Auth:     Auth{Name: "Steve"},
-	c.settings = DefaultSettings
+		Delegate: make(chan func() error),
-	c.Name = "Steve"
+		Wd: world.World{
-	c.Delegate = make(chan func() error)
+			Entities: make(map[int32]*entity.Entity, 8192),
-
+			Chunks:   make(map[world.ChunkLoc]*world.Chunk, 2048),
-	c.Wd = world.World{
+		},
-		Entities: make(map[int32]entity.Entity),
+		closing: make(chan struct{}),
-		Chunks:   make(map[world.ChunkLoc]*world.Chunk),
+		inbound: make(chan pk.Packet, 5),
 	}
-
-	return
 }
 
 //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

@@ -2,13 +2,38 @@ package bot
 
 import (
 	"github.com/Tnze/go-mc/bot/world/entity"
+	"github.com/Tnze/go-mc/bot/world/entity/player"
 	"github.com/Tnze/go-mc/chat"
 	"github.com/google/uuid"
 
 	pk "github.com/Tnze/go-mc/net/packet"
+	"github.com/Tnze/go-mc/net/ptypes"
+)
+
+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
@@ -17,6 +42,7 @@ type eventBroker struct {
 	SoundPlay      func(name string, category int, x, y, z float64, volume, pitch float32) error
 	PluginMessage  func(channel string, data []byte) error
 	HeldItemChange func(slot int) error
+	OpenWindow     func(pkt ptypes.OpenWindow) error
 
 	// ExperienceChange will be called every time player's experience level updates.
 	// Parameters:
@@ -25,10 +51,39 @@ type eventBroker struct {
 	//   total - total amount of experience received from level 0.
 	ExperienceChange func(bar float32, level int32, total int32) error
 
-	WindowsItem       func(id byte, slots []entity.Slot) error
+	WindowsItem        func(id byte, slots []entity.Slot) error
-	WindowsItemChange func(id byte, slotID int, slot entity.Slot) error
+	WindowsItemChange  func(id byte, slotID int, slot entity.Slot) error
+	WindowConfirmation func(pkt ptypes.ConfirmTransaction) 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
+
+	// PositionChange is called whenever the player position is updated.
+	PositionChange func(pos player.Pos) 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)
+
+	// PrePhysics will be called before a phyiscs tick.
+	PrePhysics func() 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/mcbot.go

@@ -9,12 +9,13 @@ import (
 	"net"
 	"strconv"
 
+	"github.com/Tnze/go-mc/data"
 	mcnet "github.com/Tnze/go-mc/net"
 	pk "github.com/Tnze/go-mc/net/packet"
 )
 
 // 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) {
@@ -98,7 +99,7 @@ func (c *Client) join(d Dialer, addr string) (err error) {
 		case 0x02: //Login Success
 			// uuid, l := pk.UnpackString(pack.Data)
 			// name, _ := unpackString(pack.Data[l:])
-			return //switches the connection state to PLAY.
+			return nil
 		case 0x03: //Set Compression
 			var threshold pk.VarInt
 			if err := pack.Scan(&threshold); err != nil {
@@ -124,3 +125,13 @@ type Dialer interface {
 func (c *Client) Conn() *mcnet.Conn {
 	return c.conn
 }
+
+// SendMessage sends a chat message.
+func (c *Client) SendMessage(msg string) error {
+	return c.conn.WritePacket(
+		pk.Marshal(
+			data.ChatServerbound,
+			pk.String(msg),
+		),
+	)
+}

bot/motion.go

@@ -6,6 +6,7 @@ import (
 
 	"github.com/Tnze/go-mc/data"
 	pk "github.com/Tnze/go-mc/net/packet"
+	"github.com/Tnze/go-mc/net/ptypes"
 )
 
 // SwingArm swing player's arm.
@@ -13,7 +14,7 @@ import (
 // It's just animation.
 func (c *Client) SwingArm(hand int) error {
 	return c.conn.WritePacket(pk.Marshal(
-		data.AnimationServerbound,
+		data.ArmAnimation,
 		pk.VarInt(hand),
 	))
 }
@@ -21,7 +22,7 @@ func (c *Client) SwingArm(hand int) error {
 // Respawn the player when it was dead.
 func (c *Client) Respawn() error {
 	return c.conn.WritePacket(pk.Marshal(
-		data.ClientStatus,
+		data.ClientCommand,
 		pk.VarInt(0),
 	))
 }
@@ -77,18 +78,17 @@ func (c *Client) Chat(msg string) error {
 	}
 
 	return c.conn.WritePacket(pk.Marshal(
-		data.ChatMessageServerbound,
+		data.ChatServerbound,
 		pk.String(msg),
 	))
 }
 
 // PluginMessage is used by mods and plugins to send their data.
-func (c *Client) PluginMessage(channal string, msg []byte) error {
+func (c *Client) PluginMessage(channel string, msg []byte) error {
-	return c.conn.WritePacket(pk.Marshal(
+	return c.conn.WritePacket((&ptypes.PluginMessage{
-		data.PluginMessageServerbound,
+		Channel: pk.Identifier(channel),
-		pk.Identifier(channal),
+		Data:    ptypes.PluginData(msg),
-		pluginMessageData(msg),
+	}).Encode())
-	))
 }
 
 // UseBlock is used to place or use a block.
@@ -103,7 +103,7 @@ func (c *Client) PluginMessage(channal string, msg []byte) error {
 // insideBlock is true when the player's head is inside of a block's collision.
 func (c *Client) UseBlock(hand, locX, locY, locZ, face int, cursorX, cursorY, cursorZ float32, insideBlock bool) error {
 	return c.conn.WritePacket(pk.Marshal(
-		data.PlayerBlockPlacement,
+		data.UseItem,
 		pk.VarInt(hand),
 		pk.Position{X: locX, Y: locY, Z: locZ},
 		pk.VarInt(face),
@@ -120,7 +120,7 @@ func (c *Client) SelectItem(slot int) error {
 	}
 
 	return c.conn.WritePacket(pk.Marshal(
-		data.HeldItemChangeServerbound,
+		data.HeldItemSlotServerbound,
 		pk.Short(slot),
 	))
 }
@@ -144,7 +144,7 @@ func (c *Client) PickItem(slot int) error {
 
 func (c *Client) playerAction(status, locX, locY, locZ, face int) error {
 	return c.conn.WritePacket(pk.Marshal(
-		data.PlayerDigging,
+		data.BlockDig,
 		pk.VarInt(status),
 		pk.Position{X: locX, Y: locY, Z: locZ},
 		pk.Byte(face),
@@ -180,7 +180,7 @@ func (c *Client) SwapItem() error {
 
 // Disconnect disconnect the server.
 // Server will close the connection.
-func (c *Client) Disconnect() error {
+func (c *Client) disconnect() error {
 	return c.conn.Close()
 }
 

bot/path/blocks.go

@@ -0,0 +1,118 @@
+package path
+
+import (
+	"github.com/Tnze/go-mc/bot/world"
+	"github.com/Tnze/go-mc/data/block"
+)
+
+var (
+	safeStepBlocks = make(map[world.BlockStatus]struct{}, 1024)
+	stepBlocks     = []block.Block{
+		block.Stone,
+		block.Granite,
+		block.PolishedGranite,
+		block.Diorite,
+		block.PolishedDiorite,
+		block.Andesite,
+		block.PolishedAndesite,
+		block.GrassBlock,
+		block.GrassPath,
+		block.Dirt,
+		block.CoarseDirt,
+		block.Cobblestone,
+		block.OakPlanks,
+		block.SprucePlanks,
+		block.BirchPlanks,
+		block.JunglePlanks,
+		block.AcaciaPlanks,
+		block.DarkOakPlanks,
+		block.Bedrock,
+		block.GoldOre,
+		block.IronOre,
+		block.CoalOre,
+		block.Glass,
+		block.LapisOre,
+		block.Sandstone,
+		block.RedstoneOre,
+		block.OakStairs,
+		block.AcaciaStairs,
+		block.DarkOakStairs,
+		block.RedSandstoneStairs,
+		block.PolishedGraniteStairs,
+		block.SmoothRedSandstoneStairs,
+		block.MossyStoneBrickStairs,
+		block.PolishedDioriteStairs,
+		block.MossyCobblestoneStairs,
+		block.EndStoneBrickStairs,
+		block.StoneStairs,
+		block.SmoothSandstoneStairs,
+		block.SmoothQuartzStairs,
+		block.GraniteStairs,
+		block.AndesiteStairs,
+		block.RedNetherBrickStairs,
+		block.PolishedAndesiteStairs,
+	}
+
+	safeWalkBlocks = make(map[world.BlockStatus]struct{}, 128)
+	walkBlocks     = []block.Block{
+		block.Air,
+		block.CaveAir,
+		block.Grass,
+		block.Torch,
+		block.OakSign,
+		block.SpruceSign,
+		block.BirchSign,
+		block.AcaciaSign,
+		block.JungleSign,
+		block.DarkOakSign,
+		block.OakWallSign,
+		block.SpruceWallSign,
+		block.BirchWallSign,
+		block.AcaciaWallSign,
+		block.JungleWallSign,
+		block.DarkOakWallSign,
+		block.Cornflower,
+		block.TallGrass,
+	}
+
+	additionalCostBlocks = map[*block.Block]int{
+		&block.Rail:        120,
+		&block.PoweredRail: 200,
+	}
+)
+
+func init() {
+	for _, b := range stepBlocks {
+		if b.MinStateID == b.MaxStateID {
+			safeStepBlocks[world.BlockStatus(b.MinStateID)] = struct{}{}
+		} else {
+			for i := b.MinStateID; i <= b.MaxStateID; i++ {
+				safeStepBlocks[world.BlockStatus(i)] = struct{}{}
+			}
+		}
+	}
+
+	for _, b := range walkBlocks {
+		if b.MinStateID == b.MaxStateID {
+			safeWalkBlocks[world.BlockStatus(b.MinStateID)] = struct{}{}
+		} else {
+			for i := b.MinStateID; i <= b.MaxStateID; i++ {
+				safeWalkBlocks[world.BlockStatus(i)] = struct{}{}
+			}
+		}
+	}
+}
+
+func SteppableBlock(bID world.BlockStatus) bool {
+	_, ok := safeStepBlocks[bID]
+	return ok
+}
+
+func AirLikeBlock(bID world.BlockStatus) bool {
+	_, ok := safeWalkBlocks[bID]
+	return ok
+}
+
+func IsLadder(bID world.BlockStatus) bool {
+	return uint32(bID) >= block.Ladder.MinStateID && uint32(bID) <= block.Ladder.MaxStateID
+}

bot/path/inputs.go

@@ -0,0 +1,10 @@
+package path
+
+// Inputs describes the desired movements of the player.
+type Inputs struct {
+	Yaw, Pitch float64
+
+	ThrottleX, ThrottleZ float64
+
+	Jump bool
+}

bot/path/movement.go

@@ -0,0 +1,358 @@
+package path
+
+import (
+	"fmt"
+
+	"github.com/Tnze/go-mc/bot/world"
+	"github.com/Tnze/go-mc/data/block"
+)
+
+// Cardinal directions.
+type Direction uint8
+
+func (d Direction) Offset() (x, y, z int) {
+	switch d {
+	case North:
+		return 0, 0, -1
+	case South:
+		return 0, 0, 1
+	case East:
+		return 1, 0, 0
+	case West:
+		return -1, 0, 0
+	}
+	panic(fmt.Sprintf("unknown direction value: %v", d))
+}
+
+func (d Direction) Offset2x() (x, y, z int) {
+	x, y, z = d.Offset()
+	return x + x, y + y, z + z
+}
+
+func (d Direction) String() string {
+	switch d {
+	case North:
+		return "north"
+	case South:
+		return "south"
+	case East:
+		return "east"
+	case West:
+		return "west"
+	}
+	return fmt.Sprintf("Direction?<%d>", int(d))
+}
+
+// Valid direction values.
+const (
+	North Direction = iota
+	South
+	West
+	East
+)
+
+func LadderDirection(bStateID world.BlockStatus) Direction {
+	return Direction(((uint32(bStateID) - block.Ladder.MinStateID) & 0xE) >> 1)
+}
+
+func ChestDirection(bStateID world.BlockStatus) Direction {
+	return Direction(((uint32(bStateID) - block.Chest.MinStateID) / 6) & 0x3)
+}
+
+func StairsDirection(bStateID world.BlockStatus) Direction {
+	b := block.StateID[uint32(bStateID)]
+	return Direction(((uint32(bStateID) - block.ByID[b].MinStateID) / 20) & 0x3)
+}
+
+// Movement represents a single type of movement in a path.
+type Movement uint8
+
+var allMovements = []Movement{TraverseNorth, TraverseSouth, TraverseEast, TraverseWest,
+	TraverseNorthWest, TraverseNorthEast, TraverseSouthWest, TraverseSouthEast,
+	DropNorth, DropSouth, DropEast, DropWest,
+	Drop2North, Drop2South, Drop2East, Drop2West,
+	AscendNorth, AscendSouth, AscendEast, AscendWest,
+	DescendLadder, DescendLadderNorth, DescendLadderSouth, DescendLadderEast, DescendLadderWest,
+	AscendLadder,
+	JumpCrossNorth, JumpCrossSouth, JumpCrossEast, JumpCrossWest,
+}
+
+// Valid movement values.
+const (
+	Waypoint Movement = iota
+	TraverseNorth
+	TraverseSouth
+	TraverseEast
+	TraverseWest
+	TraverseNorthEast
+	TraverseNorthWest
+	TraverseSouthEast
+	TraverseSouthWest
+	DropNorth
+	DropSouth
+	DropEast
+	DropWest
+	Drop2North
+	Drop2South
+	Drop2East
+	Drop2West
+	AscendNorth
+	AscendSouth
+	AscendEast
+	AscendWest
+	DescendLadder
+	DescendLadderNorth
+	DescendLadderSouth
+	DescendLadderEast
+	DescendLadderWest
+	AscendLadder
+	JumpCrossEast
+	JumpCrossWest
+	JumpCrossNorth
+	JumpCrossSouth
+)
+
+func (m Movement) Possible(nav *Nav, x, y, z int, from V3, previous Movement) bool {
+	// fmt.Printf("%s.Possible(%d,%d,%d)\n", m, x, y, z)
+	switch m {
+	case Waypoint, TraverseNorth, TraverseSouth, TraverseEast, TraverseWest:
+		if !SteppableBlock(nav.World.GetBlockStatus(x, y, z)) {
+			return false
+		}
+		b1, b2 := nav.World.GetBlockStatus(x, y+1, z), nav.World.GetBlockStatus(x, y+2, z)
+		u1, u2 := AirLikeBlock(b1) || IsLadder(b1), AirLikeBlock(b2) || IsLadder(b2)
+		return u1 && u2
+
+	case TraverseNorthWest, TraverseNorthEast, TraverseSouthWest, TraverseSouthEast:
+		if !SteppableBlock(nav.World.GetBlockStatus(x, y, z)) {
+			return false
+		}
+		if !AirLikeBlock(nav.World.GetBlockStatus(x, y+1, z)) || !AirLikeBlock(nav.World.GetBlockStatus(x, y+2, z)) {
+			return false
+		}
+		if !AirLikeBlock(nav.World.GetBlockStatus(from.X, y+1, z)) || !AirLikeBlock(nav.World.GetBlockStatus(from.X, y+2, z)) {
+			return false
+		}
+		return AirLikeBlock(nav.World.GetBlockStatus(x, y+1, from.Z)) && AirLikeBlock(nav.World.GetBlockStatus(x, y+2, from.Z))
+
+	case Drop2North, Drop2South, Drop2East, Drop2West:
+		if !AirLikeBlock(nav.World.GetBlockStatus(x, y+4, z)) {
+			return false
+		}
+		fallthrough
+
+	case DropNorth, DropSouth, DropEast, DropWest:
+		for amt := 0; amt < 3; amt++ {
+			if !AirLikeBlock(nav.World.GetBlockStatus(x, y+amt+1, z)) {
+				return false
+			}
+		}
+		return SteppableBlock(nav.World.GetBlockStatus(x, y, z))
+
+	case AscendNorth, AscendSouth, AscendEast, AscendWest:
+		if !AirLikeBlock(nav.World.GetBlockStatus(x, y+1, z)) || !AirLikeBlock(nav.World.GetBlockStatus(x, y+2, z)) {
+			return false
+		}
+		return SteppableBlock(nav.World.GetBlockStatus(x, y, z)) &&
+			AirLikeBlock(nav.World.GetBlockStatus(from.X, from.Y+1, from.Z)) &&
+			AirLikeBlock(nav.World.GetBlockStatus(from.X, from.Y+2, from.Z))
+
+	case DescendLadder, AscendLadder:
+		if bID := nav.World.GetBlockStatus(x, y+1, z); !AirLikeBlock(bID) && !IsLadder(bID) {
+			return false
+		}
+		return IsLadder(nav.World.GetBlockStatus(x, y, z))
+
+	case DescendLadderNorth, DescendLadderSouth, DescendLadderEast, DescendLadderWest:
+		for amt := 0; amt < 2; amt++ {
+			if bID := nav.World.GetBlockStatus(x, y+amt+1, z); !AirLikeBlock(bID) && !IsLadder(bID) {
+				return false
+			}
+		}
+		return IsLadder(nav.World.GetBlockStatus(x, y, z))
+
+	case JumpCrossEast, JumpCrossWest, JumpCrossNorth, JumpCrossSouth:
+		if !AirLikeBlock(nav.World.GetBlockStatus(x, y+1, z)) || !AirLikeBlock(nav.World.GetBlockStatus(x, y+2, z)) || !AirLikeBlock(nav.World.GetBlockStatus(x, y+3, z)) {
+			return false
+		}
+		midX, midZ := (from.X+x)/2, (from.Z+z)/2
+		if !AirLikeBlock(nav.World.GetBlockStatus(midX, y+1, midZ)) || !AirLikeBlock(nav.World.GetBlockStatus(midX, y+2, midZ)) || !AirLikeBlock(nav.World.GetBlockStatus(midX, y+3, midZ)) {
+			return false
+		}
+		if !AirLikeBlock(nav.World.GetBlockStatus(from.X, from.Y+3, from.Z)) {
+			return false
+		}
+		return SteppableBlock(nav.World.GetBlockStatus(x, y, z))
+
+	default:
+		panic(m)
+	}
+}
+
+func (m Movement) Offset() (x, y, z int) {
+	switch m {
+	case Waypoint:
+		return 0, 0, 0
+	case TraverseNorth:
+		return North.Offset()
+	case TraverseSouth:
+		return South.Offset()
+	case TraverseEast:
+		return East.Offset()
+	case TraverseWest:
+		return West.Offset()
+
+	case JumpCrossEast:
+		return East.Offset2x()
+	case JumpCrossWest:
+		return West.Offset2x()
+	case JumpCrossNorth:
+		return North.Offset2x()
+	case JumpCrossSouth:
+		return South.Offset2x()
+
+	case AscendLadder:
+		return 0, 1, 0
+	case DescendLadder:
+		return 0, -1, 0
+	case DropNorth, DescendLadderNorth:
+		return 0, -1, -1
+	case DropSouth, DescendLadderSouth:
+		return 0, -1, 1
+	case DropEast, DescendLadderEast:
+		return 1, -1, 0
+	case DropWest, DescendLadderWest:
+		return -1, -1, 0
+	case AscendNorth:
+		return 0, 1, -1
+	case AscendSouth:
+		return 0, 1, 1
+	case AscendEast:
+		return 1, 1, 0
+	case AscendWest:
+		return -1, 1, 0
+
+	case TraverseNorthWest:
+		return -1, 0, -1
+	case TraverseNorthEast:
+		return 1, 0, -1
+	case TraverseSouthWest:
+		return -1, 0, 1
+	case TraverseSouthEast:
+		return 1, 0, 1
+
+	case Drop2North:
+		return 0, -2, -1
+	case Drop2South:
+		return 0, -2, 1
+	case Drop2East:
+		return 1, -2, 0
+	case Drop2West:
+		return -1, -2, 0
+
+	default:
+		panic(m)
+	}
+}
+
+func (m Movement) BaseCost() float64 {
+	switch m {
+	case Waypoint:
+		return 0
+	case TraverseNorth, TraverseSouth, TraverseEast, TraverseWest:
+		return 2
+	case TraverseNorthWest, TraverseNorthEast, TraverseSouthWest, TraverseSouthEast:
+		return 2.5
+
+	case DropNorth, DropSouth, DropEast, DropWest, Drop2North, Drop2South, Drop2East, Drop2West:
+		return 4
+	case AscendNorth, AscendSouth, AscendEast, AscendWest:
+		return 4
+	case DescendLadderNorth, DescendLadderSouth, DescendLadderEast, DescendLadderWest:
+		return 1.5
+	case DescendLadder:
+		return 1
+	case AscendLadder:
+		return 3
+
+	case JumpCrossEast, JumpCrossWest, JumpCrossNorth, JumpCrossSouth:
+		return 5.5
+	default:
+		panic(m)
+	}
+}
+
+func (m Movement) String() string {
+	switch m {
+	case Waypoint:
+		return "waypoint"
+	case TraverseNorth:
+		return "traverse-north"
+	case TraverseSouth:
+		return "traverse-south"
+	case TraverseEast:
+		return "traverse-east"
+	case TraverseWest:
+		return "traverse-west"
+
+	case DropNorth:
+		return "drop-north"
+	case DropSouth:
+		return "drop-south"
+	case DropEast:
+		return "drop-east"
+	case DropWest:
+		return "drop-west"
+	case Drop2North:
+		return "drop-2-north"
+	case Drop2South:
+		return "drop-2-south"
+	case Drop2East:
+		return "drop-2-east"
+	case Drop2West:
+		return "drop-2-west"
+
+	case AscendNorth:
+		return "jump-north"
+	case AscendSouth:
+		return "jump-south"
+	case AscendEast:
+		return "jump-east"
+	case AscendWest:
+		return "jump-west"
+
+	case TraverseNorthWest:
+		return "traverse-northwest"
+	case TraverseNorthEast:
+		return "traverse-northeast"
+	case TraverseSouthWest:
+		return "traverse-southwest"
+	case TraverseSouthEast:
+		return "traverse-southeast"
+
+	case DescendLadder:
+		return "descend-ladder"
+	case DescendLadderNorth:
+		return "descend-ladder-north"
+	case DescendLadderSouth:
+		return "descend-ladder-south"
+	case DescendLadderEast:
+		return "descend-ladder-east"
+	case DescendLadderWest:
+		return "descend-ladder-west"
+
+	case AscendLadder:
+		return "ascend-ladder"
+
+	case JumpCrossEast:
+		return "jump-crossing-east"
+	case JumpCrossWest:
+		return "jump-crossing-west"
+	case JumpCrossNorth:
+		return "jump-crossing-north"
+	case JumpCrossSouth:
+		return "jump-crossing-south"
+	default:
+		panic(m)
+	}
+}

bot/path/path.go

@@ -0,0 +1,196 @@
+// Package path implements pathfinding.
+package path
+
+import (
+	"math"
+	"math/rand"
+	"strings"
+	"time"
+
+	"github.com/Tnze/go-mc/bot/world"
+	"github.com/Tnze/go-mc/data/block"
+	"github.com/beefsack/go-astar"
+)
+
+// Point represents a point in 3D space.
+type Point struct {
+	X, Y, Z float64
+}
+
+type V3 struct {
+	X, Y, Z int
+}
+
+func (v V3) Cost(other V3) float64 {
+	x, y, z := v.X-other.X, v.Y-other.Y, v.Z-other.Z
+	return math.Sqrt(float64(x*x+z*z)) + math.Sqrt(1.2*float64(y*y))
+}
+
+// Nav represents a navigation to a position.
+type Nav struct {
+	World       *world.World
+	Start, Dest V3
+}
+
+func (n *Nav) Path() (path []astar.Pather, distance float64, found bool) {
+	return astar.Path(
+		Tile{ // Start point
+			Nav:      n,
+			Movement: Waypoint,
+			Pos:      n.Start,
+		},
+		Tile{ // Destination point
+			Nav:      n,
+			Movement: Waypoint,
+			Pos:      n.Dest,
+		})
+}
+
+// Tile represents a point in a path. All tiles in a path are adjaceent their
+// preceeding tiles.
+type Tile struct {
+	Nav *Nav
+
+	Movement    Movement
+	Pos         V3
+	BlockStatus world.BlockStatus
+	ExtraCost   int
+}
+
+func (t Tile) PathNeighborCost(to astar.Pather) float64 {
+	other := to.(Tile)
+	return 1 + other.Movement.BaseCost()
+}
+
+func (t Tile) PathEstimatedCost(to astar.Pather) float64 {
+	other := to.(Tile)
+	cost := t.Pos.Cost(other.Pos)
+
+	return cost + other.Movement.BaseCost()
+}
+
+func (t Tile) PathNeighbors() []astar.Pather {
+	possibles := make([]astar.Pather, 0, 8)
+
+	if c := t.PathEstimatedCost(Tile{Pos: t.Nav.Start}); c > 8000 {
+		return nil
+	}
+
+	if t.Pos == t.Nav.Dest && t.Movement != Waypoint {
+		dupe := t
+		dupe.Movement = Waypoint
+		dupe.BlockStatus = 0
+		return []astar.Pather{dupe}
+	}
+
+	for _, m := range allMovements {
+		x, y, z := m.Offset()
+		pos := V3{X: t.Pos.X + x, Y: t.Pos.Y + y, Z: t.Pos.Z + z}
+		possible := m.Possible(t.Nav, pos.X, pos.Y, pos.Z, t.Pos, t.Movement)
+		// fmt.Printf("%v-%v: Trying (%v) %v: possible=%v\n", t.Movement, t.Pos, pos, m, possible)
+		if possible {
+			possibles = append(possibles, Tile{
+				Nav:         t.Nav,
+				Movement:    m,
+				Pos:         pos,
+				BlockStatus: t.Nav.World.GetBlockStatus(pos.X, pos.Y, pos.Z),
+			})
+		}
+	}
+
+	// fmt.Printf("%v.Neighbours(): %+v\n", t.Pos, possibles)
+	return possibles
+}
+
+func (t Tile) Inputs(pos, deltaPos, vel Point, runTime time.Duration) Inputs {
+	// Sufficient for simple movements.
+	at := math.Atan2(-deltaPos.X, -deltaPos.Z)
+	mdX, _, mdZ := t.Movement.Offset()
+	wantYaw := -math.Atan2(float64(mdX), float64(mdZ)) * 180 / math.Pi
+	out := Inputs{
+		ThrottleX: math.Sin(at),
+		ThrottleZ: math.Cos(at),
+		Yaw:       wantYaw,
+	}
+	if mdX == 0 && mdZ == 0 {
+		out.Yaw = math.NaN()
+	}
+	if (rand.Int() % 14) == 0 {
+		out.Pitch = float64((rand.Int() % 4) - 2)
+	}
+
+	switch t.Movement {
+	case DescendLadder, DescendLadderEast, DescendLadderWest, DescendLadderNorth, DescendLadderSouth:
+		// Deadzone the throttle to prevent an accidental ascend.
+		if dist2 := math.Sqrt(deltaPos.X*deltaPos.X + deltaPos.Z*deltaPos.Z); dist2 < (0.22 * 0.22 * 2) {
+			out.ThrottleX, out.ThrottleZ = 0, 0
+		}
+
+	case AscendLadder:
+		dist2 := math.Sqrt(deltaPos.X*deltaPos.X + deltaPos.Z*deltaPos.Z)
+
+		if x, _, z := LadderDirection(t.BlockStatus).Offset(); dist2 > (0.8*0.8) && deltaPos.Y < 0 {
+			pos.X -= (0.25 * float64(x))
+			pos.Z -= (0.25 * float64(z))
+		} else {
+			pos.X += (0.42 * float64(x))
+			pos.Z += (0.42 * float64(z))
+		}
+
+		at = math.Atan2(-pos.X+float64(t.Pos.X)+0.5, -pos.Z+float64(t.Pos.Z)+0.5)
+		out = Inputs{
+			ThrottleX: math.Sin(at),
+			ThrottleZ: math.Cos(at),
+			Yaw:       math.NaN(),
+		}
+
+	case AscendNorth, AscendSouth, AscendEast, AscendWest:
+		var (
+			b          = block.ByID[block.StateID[uint32(t.BlockStatus)]]
+			isStairs   = strings.HasSuffix(b.Name, "_stairs")
+			maybeStuck = runTime < 1250*time.Millisecond
+			dist2      = math.Sqrt(deltaPos.X*deltaPos.X + deltaPos.Z*deltaPos.Z)
+		)
+		out.Jump = dist2 < 1.75 && deltaPos.Y < -0.81
+
+		// Special logic for stairs: Try to go towards the downwards edge initially.
+		if isStairs && dist2 > (0.9*0.9) && deltaPos.Y < 0 {
+			if x, _, z := StairsDirection(t.BlockStatus).Offset(); dist2 > (0.9*0.9) && deltaPos.Y < 0 {
+				pos.X += (0.49 * float64(x))
+				pos.Z += (0.49 * float64(z))
+			}
+
+			at = math.Atan2(-pos.X+float64(t.Pos.X)+0.5, -pos.Z+float64(t.Pos.Z)+0.5)
+			out = Inputs{
+				ThrottleX: math.Sin(at),
+				ThrottleZ: math.Cos(at),
+				Yaw:       math.NaN(),
+				Jump:      out.Jump && !maybeStuck,
+			}
+		}
+
+		// Turn off the throttle if we get stuck on the jump.
+		if dist2 < 1 && deltaPos.Y < 0 && vel.Y == 0 {
+			out.ThrottleX, out.ThrottleZ = 0, 0
+		}
+
+	case JumpCrossEast, JumpCrossWest, JumpCrossNorth, JumpCrossSouth:
+		dist2 := math.Sqrt(deltaPos.X*deltaPos.X + deltaPos.Z*deltaPos.Z)
+		out.Jump = dist2 > 1.5 && dist2 < 1.78
+	}
+	return out
+}
+
+func (t Tile) IsComplete(d Point) bool {
+	switch t.Movement {
+	case DescendLadder, DescendLadderNorth, DescendLadderSouth, DescendLadderWest, DescendLadderEast,
+		DropNorth, DropSouth, DropEast, DropWest:
+		return (d.X*d.X+d.Z*d.Z) < (2*0.2*0.25) && d.Y <= 0.05
+	case AscendLadder:
+		return d.Y >= 0
+	case JumpCrossEast, JumpCrossWest, JumpCrossNorth, JumpCrossSouth:
+		return (d.X*d.X+d.Z*d.Z) < (0.22*0.22) && d.Y >= -0.065
+	}
+
+	return (d.X*d.X+d.Z*d.Z) < (0.18*0.18) && d.Y >= -0.065 && d.Y <= 0.08
+}

bot/phy/aabb.go

@@ -0,0 +1,143 @@
+package phy
+
+import (
+	"math"
+
+	"github.com/Tnze/go-mc/bot/world"
+)
+
+type MinMax struct {
+	Min, Max float64
+}
+
+// Extends adjusts the bounds of the MinMax. A negative number will reduce the
+// minimum bound, whereas a positive number will increase the maximum bound.
+func (mm MinMax) Extend(delta float64) MinMax {
+	if delta < 0 {
+		return MinMax{
+			Min: mm.Min + delta,
+			Max: mm.Max,
+		}
+	}
+
+	return MinMax{
+		Min: mm.Min,
+		Max: mm.Max + delta,
+	}
+}
+
+// Contract reduces both the minimum and maximum bound by the provided amount,
+// such that the difference between the bounds decreases for positive values.
+func (mm MinMax) Contract(amt float64) MinMax {
+	return MinMax{
+		Min: mm.Min + amt,
+		Max: mm.Max - amt,
+	}
+}
+
+// Expand changes the minimum and maximum bounds by the provided amount, such
+// that the difference between the bounds increases for positive values.
+func (mm MinMax) Expand(amt float64) MinMax {
+	return MinMax{
+		Min: mm.Min - amt,
+		Max: mm.Max + amt,
+	}
+}
+
+// Offset adds the provided value to both the minimum and maximum value.
+func (mm MinMax) Offset(amt float64) MinMax {
+	return MinMax{
+		Min: mm.Min + amt,
+		Max: mm.Max + amt,
+	}
+}
+
+// AABB implements Axis Aligned Bounding Box operations.
+type AABB struct {
+	X, Y, Z MinMax
+	Block   world.BlockStatus
+}
+
+// Extend adjusts the minimum (for negative values) or maximum bounds (for
+// positive values) by the provided scalar for each dimension.
+func (bb AABB) Extend(dx, dy, dz float64) AABB {
+	return AABB{
+		X:     bb.X.Extend(dx),
+		Y:     bb.Y.Extend(dx),
+		Z:     bb.Z.Extend(dx),
+		Block: bb.Block,
+	}
+}
+
+// Contract reduces the difference between the min/max bounds (for positive
+// values) for each dimension.
+func (bb AABB) Contract(x, y, z float64) AABB {
+	return AABB{
+		X:     bb.X.Contract(x),
+		Y:     bb.Y.Contract(y),
+		Z:     bb.Z.Contract(z),
+		Block: bb.Block,
+	}
+}
+
+// Expand increases both the minimum and maximum bounds by the provided amount
+// (for positive values) for each dimension.
+func (bb AABB) Expand(x, y, z float64) AABB {
+	return AABB{
+		X:     bb.X.Expand(x),
+		Y:     bb.Y.Expand(y),
+		Z:     bb.Z.Expand(z),
+		Block: bb.Block,
+	}
+}
+
+// Offset moves both the minimum and maximum bound by the provided value for
+// each dimension.
+func (bb AABB) Offset(x, y, z float64) AABB {
+	return AABB{
+		X:     bb.X.Offset(x),
+		Y:     bb.Y.Offset(y),
+		Z:     bb.Z.Offset(z),
+		Block: bb.Block,
+	}
+}
+
+func (bb AABB) XOffset(o AABB, xOffset float64) float64 {
+	if o.Y.Max > bb.Y.Min && o.Y.Min < bb.Y.Max && o.Z.Max > bb.Z.Min && o.Z.Min < bb.Z.Max {
+		if xOffset > 0.0 && o.X.Max <= bb.X.Min {
+			xOffset = math.Min(bb.X.Min-o.X.Max, xOffset)
+		} else if xOffset < 0.0 && o.X.Min >= bb.X.Max {
+			xOffset = math.Max(bb.X.Max-o.X.Min, xOffset)
+		}
+	}
+	return xOffset
+}
+
+func (bb AABB) YOffset(o AABB, yOffset float64) float64 {
+	if o.X.Max > bb.X.Min && o.X.Min < bb.X.Max && o.Z.Max > bb.Z.Min && o.Z.Min < bb.Z.Max {
+		if yOffset > 0.0 && o.Y.Max <= bb.Y.Min {
+			yOffset = math.Min(bb.Y.Min-o.Y.Max, yOffset)
+		} else if yOffset < 0.0 && o.Y.Min >= bb.Y.Max {
+			yOffset = math.Max(bb.Y.Max-o.Y.Min, yOffset)
+		}
+	}
+	return yOffset
+}
+
+func (bb AABB) ZOffset(o AABB, zOffset float64) float64 {
+	if o.X.Max > bb.X.Min && o.X.Min < bb.X.Max && o.Y.Max > bb.Y.Min && o.Y.Min < bb.Y.Max {
+		if zOffset > 0.0 && o.Z.Max <= bb.Z.Min {
+			zOffset = math.Min(bb.Z.Min-o.Z.Max, zOffset)
+		} else if zOffset < 0.0 && o.Z.Min >= bb.Z.Max {
+			zOffset = math.Max(bb.Z.Max-o.Z.Min, zOffset)
+		}
+	}
+	return zOffset
+}
+
+func (bb AABB) Intersects(o AABB) bool {
+	return true &&
+		bb.X.Min < o.X.Max && bb.X.Max > o.X.Min &&
+		bb.Y.Min < o.Y.Max && bb.Y.Max > o.Y.Min &&
+		bb.Z.Min < o.Z.Max && bb.Z.Max > o.Z.Min
+}

bot/phy/phy.go

@@ -0,0 +1,300 @@
+// Package phy implements a minimal physics simulation necessary for realistic
+// bot behavior.
+package phy
+
+import (
+	"fmt"
+	"math"
+
+	"github.com/Tnze/go-mc/bot/path"
+	"github.com/Tnze/go-mc/bot/world"
+	"github.com/Tnze/go-mc/bot/world/entity/player"
+	"github.com/Tnze/go-mc/data/block/shape"
+)
+
+const (
+	playerWidth  = 0.6
+	playerHeight = 1.8
+	resetVel     = 0.003
+
+	maxYawChange   = 11
+	maxPitchChange = 7
+
+	stepHeight       = 0.6
+	minJumpTicks     = 14
+	ladderMaxSpeed   = 0.15
+	ladderClimbSpeed = 0.2
+
+	gravity      = 0.08
+	drag         = 0.98
+	acceleration = 0.02
+	inertia      = 0.91
+	slipperiness = 0.6
+)
+
+// World represents a provider of information about the surrounding world.
+type World interface {
+	GetBlockStatus(x, y, z int) world.BlockStatus
+}
+
+// Surrounds represents the blocks surrounding the player (Y, Z, X).
+type Surrounds []AABB
+
+// State tracks physics state.
+type State struct {
+	// player state.
+	Pos        path.Point
+	Vel        path.Point
+	Yaw, Pitch float64
+	lastJump   uint32
+
+	// player state flags.
+	onGround  bool
+	collision struct {
+		vertical   bool
+		horizontal bool
+	}
+
+	tick uint32
+	Run  bool
+}
+
+func (s *State) ServerPositionUpdate(player player.Pos, w World) error {
+	fmt.Printf("TELEPORT (y=%0.2f, velY=%0.3f): %0.2f, %0.2f, %0.2f\n", s.Pos.Y, s.Vel.Y, player.X-s.Pos.X, player.Y-s.Pos.Y, player.Z-s.Pos.Z)
+
+	s.Pos = path.Point{X: player.X, Y: player.Y, Z: player.Z}
+	s.Yaw, s.Pitch = float64(player.Yaw), float64(player.Pitch)
+	s.Vel = path.Point{}
+	s.onGround, s.collision.vertical, s.collision.horizontal = false, false, false
+	s.Run = true
+	return nil
+}
+
+func abs(i1, i2 int) int {
+	if i1 < i2 {
+		return i2 - i1
+	}
+	return i1 - i2
+}
+
+func (s *State) surroundings(query AABB, w World) Surrounds {
+	minY, maxY := int(math.Floor(query.Y.Min))-1, int(math.Floor(query.Y.Max))+1
+	minZ, maxZ := int(math.Floor(query.Z.Min)), int(math.Floor(query.Z.Max))+1
+	minX, maxX := int(math.Floor(query.X.Min)), int(math.Floor(query.X.Max))+1
+
+	out := Surrounds(make([]AABB, 0, abs(maxY, minY)*abs(maxZ, minZ)*abs(maxX, minX)*2))
+	for y := minY; y < maxY; y++ {
+		for z := minZ; z < maxZ; z++ {
+			for x := minX; x < maxX; x++ {
+				bStateID := w.GetBlockStatus(x, y, z)
+				if !path.AirLikeBlock(bStateID) {
+					bbs, err := shape.CollisionBoxes(bStateID)
+					if err != nil {
+						panic(err)
+					}
+					for _, box := range bbs {
+						out = append(out, AABB{
+							X:     MinMax{Min: box.Min.X, Max: box.Max.X},
+							Y:     MinMax{Min: box.Min.Y, Max: box.Max.Y},
+							Z:     MinMax{Min: box.Min.Z, Max: box.Max.Z},
+							Block: bStateID,
+						}.Offset(float64(x), float64(y), float64(z)))
+					}
+				}
+			}
+		}
+	}
+	return out
+}
+
+func (s *State) BB() AABB {
+	return AABB{
+		X: MinMax{Min: -playerWidth / 2, Max: playerWidth / 2},
+		Y: MinMax{Max: playerHeight},
+		Z: MinMax{Min: -playerWidth / 2, Max: playerWidth / 2},
+	}.Offset(s.Pos.X, s.Pos.Y, s.Pos.Z)
+}
+
+func (s *State) Position() player.Pos {
+	return player.Pos{
+		X: s.Pos.X, Y: s.Pos.Y, Z: s.Pos.Z,
+		Yaw: float32(s.Yaw), Pitch: float32(s.Pitch),
+		OnGround: s.onGround,
+	}
+}
+
+func (s *State) Tick(input path.Inputs, w World) error {
+	s.tick++
+	if !s.Run {
+		return nil
+	}
+
+	var inertia = inertia
+	var acceleration = acceleration
+	if below := w.GetBlockStatus(int(math.Floor(s.Pos.X)), int(math.Floor(s.Pos.Y))-1, int(math.Floor(s.Pos.Z))); s.onGround && !path.AirLikeBlock(below) {
+		inertia *= slipperiness
+		acceleration = 0.1 * (0.1627714 / (inertia * inertia * inertia))
+	}
+
+	s.tickVelocity(input, inertia, acceleration, w)
+	s.tickPosition(w)
+
+	if path.IsLadder(w.GetBlockStatus(int(math.Floor(s.Pos.X)), int(math.Floor(s.Pos.Y)), int(math.Floor(s.Pos.Z)))) && s.collision.horizontal {
+		s.Vel.Y = ladderClimbSpeed
+	}
+
+	// Gravity
+	s.Vel.Y -= gravity
+	// Drag & friction.
+	s.Vel.Y *= drag
+	s.Vel.X *= inertia
+	s.Vel.Z *= inertia
+	return nil
+}
+
+func (s *State) tickVelocity(input path.Inputs, inertia, acceleration float64, w World) {
+
+	// Deadzone velocities when they get too low.
+	if math.Abs(s.Vel.X) < resetVel {
+		s.Vel.X = 0
+	}
+	if math.Abs(s.Vel.Y) < resetVel {
+		s.Vel.Y = 0
+	}
+	if math.Abs(s.Vel.Z) < resetVel {
+		s.Vel.Z = 0
+	}
+
+	s.applyLookInputs(input)
+	s.applyPosInputs(input, acceleration, inertia)
+
+	lower := w.GetBlockStatus(int(math.Floor(s.Pos.X)), int(math.Floor(s.Pos.Y)), int(math.Floor(s.Pos.Z)))
+	if path.IsLadder(lower) {
+		s.Vel.X = math.Min(math.Max(-ladderMaxSpeed, s.Vel.X), ladderMaxSpeed)
+		s.Vel.Z = math.Min(math.Max(-ladderMaxSpeed, s.Vel.Z), ladderMaxSpeed)
+		s.Vel.Y = math.Min(math.Max(-ladderMaxSpeed, s.Vel.Y), ladderMaxSpeed)
+	}
+}
+
+func (s *State) applyLookInputs(input path.Inputs) {
+	if !math.IsNaN(input.Yaw) {
+		errYaw := math.Min(math.Max(modYaw(input.Yaw, s.Yaw), -maxYawChange), maxYawChange)
+		s.Yaw += errYaw
+	}
+	errPitch := math.Min(math.Max(input.Pitch-s.Pitch, -maxPitchChange), maxPitchChange)
+	s.Pitch += errPitch
+}
+
+func (s *State) applyPosInputs(input path.Inputs, acceleration, inertia float64) {
+	// fmt.Println(input.Jump, s.lastJump, s.onGround)
+	if input.Jump && s.lastJump+minJumpTicks < s.tick && s.onGround {
+		s.lastJump = s.tick
+		s.Vel.Y = 0.42
+	}
+
+	speed := math.Sqrt(input.ThrottleX*input.ThrottleX + input.ThrottleZ*input.ThrottleZ)
+	if speed < 0.01 {
+		return
+	}
+	speed = acceleration / math.Max(speed, 1)
+
+	input.ThrottleX *= speed
+	input.ThrottleZ *= speed
+
+	s.Vel.X += input.ThrottleX
+	s.Vel.Z += input.ThrottleZ
+}
+
+func (s *State) tickPosition(w World) {
+	// fmt.Printf("TICK POSITION: %0.2f, %0.2f, %0.2f - (%0.2f, %0.2f, %0.2f)\n", s.Pos.X, s.Pos.Y, s.Pos.Z, s.Vel.X, s.Vel.Y, s.Vel.Z)
+
+	player, newVel := s.computeCollisionYXZ(s.BB(), s.BB().Offset(s.Vel.X, s.Vel.Y, s.Vel.Z), s.Vel, w)
+	//fmt.Printf("offset = %0.2f, %0.2f, %0.2f\n", player.X.Min-s.Pos.X, player.Y.Min-s.Pos.Y, player.Z.Min-s.Pos.Z)
+
+	//fmt.Printf("onGround = %v, s.Vel.Y = %0.3f, newVel.Y = %0.3f\n", s.onGround, s.Vel.Y, newVel.Y)
+	if s.onGround || (s.Vel.Y != newVel.Y && s.Vel.Y < 0) {
+		bb := s.BB()
+		//fmt.Printf("Player pos = %0.2f, %0.2f, %0.2f\n", bb.X.Min, bb.Y.Min, bb.Z.Min)
+		surroundings := s.surroundings(bb.Offset(s.Vel.X, stepHeight, s.Vel.Y), w)
+		outVel := s.Vel
+
+		outVel.Y = stepHeight
+		for _, b := range surroundings {
+			outVel.Y = b.YOffset(bb, outVel.Y)
+		}
+		bb = bb.Offset(0, outVel.Y, 0)
+		for _, b := range surroundings {
+			outVel.X = b.XOffset(bb, outVel.X)
+		}
+		bb = bb.Offset(outVel.X, 0, 0)
+		for _, b := range surroundings {
+			outVel.Z = b.ZOffset(bb, outVel.Z)
+		}
+		bb = bb.Offset(0, 0, outVel.Z)
+		//fmt.Printf("Post-collision = %0.2f, %0.2f, %0.2f\n", bb.X.Min, bb.Y.Min, bb.Z.Min)
+
+		outVel.Y *= -1
+		// Lower the player back down to be on the ground.
+		for _, b := range surroundings {
+			outVel.Y = b.YOffset(bb, outVel.Y)
+		}
+		bb = bb.Offset(0, outVel.Y, 0)
+		//fmt.Printf("Post-lower = %0.2f, %0.2f, %0.2f\n", bb.X.Min, bb.Y.Min, bb.Z.Min)
+
+		oldMove := newVel.X*newVel.X + newVel.Z*newVel.Z
+		newMove := outVel.X*outVel.X + outVel.Z*outVel.Z
+		// fmt.Printf("oldMove = %0.2f, newMove = %0.2f\n", oldMove*1000, newMove*1000)
+		if oldMove >= newMove || outVel.Y <= (0.000002-stepHeight) {
+			// fmt.Println("nope")
+		} else {
+			player = bb
+			newVel = outVel
+		}
+	}
+
+	// Update flags.
+	s.Pos.X = player.X.Min + playerWidth/2
+	s.Pos.Y = player.Y.Min
+	s.Pos.Z = player.Z.Min + playerWidth/2
+	s.collision.horizontal = newVel.X != s.Vel.X || newVel.Z != s.Vel.Z
+	s.collision.vertical = newVel.Y != s.Vel.Y
+	s.onGround = s.collision.vertical && s.Vel.Y < 0
+	s.Vel = newVel
+}
+
+func modYaw(new, old float64) float64 {
+	delta := math.Mod(new-old, 360)
+	if delta > 180 {
+		delta = 180 - delta
+	} else if delta < -180 {
+		delta += 360
+	}
+	// fmt.Printf("(%.2f - %.2f) = %.2f\n", new, old, delta)
+	return delta
+}
+
+func (s *State) computeCollisionYXZ(bb, query AABB, vel path.Point, w World) (outBB AABB, outVel path.Point) {
+	surroundings := s.surroundings(query, w)
+	outVel = vel
+
+	for _, b := range surroundings {
+		outVel.Y = b.YOffset(bb, outVel.Y)
+	}
+	bb = bb.Offset(0, outVel.Y, 0)
+	for _, b := range surroundings {
+		outVel.X = b.XOffset(bb, outVel.X)
+	}
+	bb = bb.Offset(outVel.X, 0, 0)
+	for _, b := range surroundings {
+		outVel.Z = b.ZOffset(bb, outVel.Z)
+	}
+	bb = bb.Offset(0, 0, outVel.Z)
+	return bb, outVel
+}
+
+// AtLookTarget returns true if the player look position is actually at the
+// given pitch and yaw.
+func (s *State) AtLookTarget(yaw, pitch float64) bool {
+	dYaw, dPitch := math.Abs(modYaw(yaw, s.Yaw)), math.Abs(pitch-s.Pitch)
+	return dYaw <= 0.8 && dPitch <= 1.1
+}

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",
 }

bot/world/bitarray.go

@@ -0,0 +1,38 @@
+package world
+
+// bitArray implements a bitfield array where values are packed into uint64
+// values. If the next value does not fit into remaining space, the remaining
+// space of a uint64 is unused.
+type bitArray struct {
+	width          uint // bit width of each value
+	valsPerElement uint // number of values which fit into a single uint64.
+
+	data []uint64
+}
+
+// Size returns the number of elements that can fit into the bit array.
+func (b *bitArray) Size() int {
+	return int(b.valsPerElement) * len(b.data)
+}
+
+func (b *bitArray) Set(idx, val uint) {
+	var (
+		arrayIdx = idx / b.valsPerElement
+		startBit = (idx % b.valsPerElement) * b.width
+		mask     = ^uint64((1<<b.width - 1) << startBit) // set for all bits except target
+	)
+	b.data[arrayIdx] = (b.data[arrayIdx] & mask) | uint64(val<<startBit)
+}
+
+func (b *bitArray) Get(idx uint) uint {
+	var (
+		arrayIdx = idx / b.valsPerElement
+		offset   = (idx % b.valsPerElement) * b.width
+		mask     = uint64((1<<b.width - 1) << offset) // set for just the target
+	)
+	return uint(b.data[arrayIdx]&mask) >> offset
+}
+
+func valsPerBitArrayElement(bitsPerValue uint) uint {
+	return uint(64 / bitsPerValue)
+}

bot/world/bitarray_test.go

@@ -0,0 +1,50 @@
+package world
+
+import (
+	"encoding/binary"
+	"encoding/hex"
+	"testing"
+)
+
+func TestBitArrayBasic(t *testing.T) {
+	a := bitArray{
+		width:          5,
+		valsPerElement: valsPerBitArrayElement(5),
+		data:           make([]uint64, 5),
+	}
+
+	if got, want := a.Size(), 12*5; got != want {
+		t.Errorf("size = %d, want %d", got, want)
+	}
+
+	a.Set(0, 4)
+	if v := a.Get(0); v != 4 {
+		t.Errorf("v[0] = %d, want 4", v)
+	}
+	a.Set(12, 8)
+	if v := a.Get(12); v != 8 {
+		t.Errorf("v[12] = %d, want 8", v)
+	}
+}
+
+func TestBitArrayHardcoded(t *testing.T) {
+	d1, _ := hex.DecodeString("0020863148418841")
+	d2, _ := hex.DecodeString("01018A7260F68C87")
+
+	a := bitArray{
+		width:          5,
+		valsPerElement: valsPerBitArrayElement(5),
+		data:           []uint64{binary.BigEndian.Uint64(d1), binary.BigEndian.Uint64(d2)},
+	}
+
+	if got, want := a.Size(), 12*2; got != want {
+		t.Errorf("size = %d, want %d", got, want)
+	}
+
+	want := []uint{1, 2, 2, 3, 4, 4, 5, 6, 6, 4, 8, 0, 7, 4, 3, 13, 15, 16, 9, 14, 10, 12, 0, 2}
+	for idx, want := range want {
+		if got := a.Get(uint(idx)); got != want {
+			t.Errorf("v[%d] = %d, want %d", idx, got, want)
+		}
+	}
+}

bot/world/chunk.go

@@ -3,10 +3,14 @@ package world
 import (
 	"bytes"
 	"fmt"
-	"github.com/Tnze/go-mc/data"
+	"math"
+
+	"github.com/Tnze/go-mc/data/block"
 	pk "github.com/Tnze/go-mc/net/packet"
 )
 
+const maxPaletteBits = 8
+
 // DecodeChunkColumn decode the chunk data structure.
 // If decoding went error, successful decoded data will be returned.
 func DecodeChunkColumn(mask int32, data []byte) (*Chunk, error) {
@@ -26,35 +30,35 @@ func DecodeChunkColumn(mask int32, data []byte) (*Chunk, error) {
 	return &c, nil
 }
 
-func perBits(BitsPerBlock byte) int {
+func perBits(bpb byte) uint {
 	switch {
-	case BitsPerBlock <= 4:
+	case bpb <= 4:
 		return 4
-	case BitsPerBlock < 9:
+	case bpb <= maxPaletteBits:
-		return int(BitsPerBlock)
+		return uint(bpb)
 	default:
-		return data.BitsPerBlock // DefaultBitsPerBlock
+		return uint(block.BitsPerBlock)
 	}
 }
 
 func readSection(data pk.DecodeReader) (s Section, err error) {
-	var BlockCount pk.Short
+	var nonAirBlockCount pk.Short
-	if err := BlockCount.Decode(data); err != nil {
+	if err := nonAirBlockCount.Decode(data); err != nil {
-		return nil, fmt.Errorf("read block count error: %w", err)
+		return nil, fmt.Errorf("block count: %w", err)
 	}
 	var bpb pk.UnsignedByte
 	if err := bpb.Decode(data); err != nil {
-		return nil, fmt.Errorf("read bits per block error: %w", err)
+		return nil, fmt.Errorf("bits per block: %w", err)
 	}
 	// If bpb values greater than or equal to 9, use directSection.
 	// Otherwise use paletteSection.
 	var palettes []BlockStatus
 	var palettesIndex map[BlockStatus]int
-	if bpb < 9 {
+	if bpb <= maxPaletteBits {
 		// read palettes
 		var length pk.VarInt
 		if err := length.Decode(data); err != nil {
-			return nil, fmt.Errorf("read palettes length error: %w", err)
+			return nil, fmt.Errorf("palette length: %w", err)
 		}
 		palettes = make([]BlockStatus, length)
 		palettesIndex = make(map[BlockStatus]int, length)
@@ -85,8 +89,15 @@ func readSection(data pk.DecodeReader) (s Section, err error) {
 		dataArray[i] = uint64(v)
 	}
 
-	sec := directSection{bpb: perBits(byte(bpb)), data: dataArray}
+	width := perBits(byte(bpb))
-	if bpb < 9 {
+	sec := directSection{
+		bitArray{
+			width:          width,
+			valsPerElement: valsPerBitArrayElement(width),
+			data:           dataArray,
+		},
+	}
+	if bpb <= maxPaletteBits {
 		return &paletteSection{
 			palette:       palettes,
 			palettesIndex: palettesIndex,
@@ -98,46 +109,38 @@ func readSection(data pk.DecodeReader) (s Section, err error) {
 }
 
 type directSection struct {
-	bpb  int
+	bitArray
-	data []uint64
 }
 
-func (d *directSection) GetBlock(offset int) BlockStatus {
+func (d *directSection) GetBlock(offset uint) BlockStatus {
-	offset *= d.bpb
+	return BlockStatus(d.Get(offset))
-	padding := offset % 64
-	block := uint32(d.data[offset/64] >> padding)
-	if padding > 64-d.bpb {
-		l := 64 - padding
-		block |= uint32(d.data[offset/64+1] << l)
-	}
-	return BlockStatus(block & (1<<d.bpb - 1)) // mask
 }
 
-func (d *directSection) SetBlock(offset int, s BlockStatus) {
+func (d *directSection) SetBlock(offset uint, s BlockStatus) {
-	offset *= d.bpb
+	d.Set(offset, uint(s))
-	padding := offset % 64
-	mask := ^uint64((1<<d.bpb - 1) << padding)
-	d.data[offset/64] = d.data[offset/64]&mask | uint64(s)<<padding
-	if padding > 64-d.bpb {
-		l := padding - (64 - d.bpb)
-		const maxUint64 = 1<<64 - 1
-		d.data[offset/64+1] = d.data[offset/64+1]&(maxUint64<<l) | uint64(s)>>(64-padding)
-	}
 }
 
 func (d *directSection) CanContain(s BlockStatus) bool {
-	return s <= (1<<d.bpb - 1)
+	return s <= (1<<d.width - 1)
 }
 
-func (d *directSection) clone(bpb int) *directSection {
+func (d *directSection) clone(bpb uint) *directSection {
-	newSection := &directSection{
+	out := newSectionWithSize(bpb)
-		bpb:  bpb,
+	for offset := uint(0); offset < 16*16*16; offset++ {
-		data: make([]uint64, 16*16*16*bpb/64),
+		out.SetBlock(offset, d.GetBlock(offset))
 	}
-	for offset := 0; offset < 16*16*16; offset++ {
+	return out
-		newSection.SetBlock(offset, d.GetBlock(offset))
+}
+
+func newSectionWithSize(bpb uint) *directSection {
+	valsPerElement := valsPerBitArrayElement(bpb)
+	return &directSection{
+		bitArray{
+			width:          bpb,
+			valsPerElement: valsPerElement,
+			data:           make([]uint64, int(math.Ceil(16*16*16/float64(valsPerElement)))),
+		},
 	}
-	return newSection
 }
 
 type paletteSection struct {
@@ -146,12 +149,12 @@ type paletteSection struct {
 	directSection
 }
 
-func (p *paletteSection) GetBlock(offset int) BlockStatus {
+func (p *paletteSection) GetBlock(offset uint) BlockStatus {
 	v := p.directSection.GetBlock(offset)
 	return p.palette[v]
 }
 
-func (p *paletteSection) SetBlock(offset int, s BlockStatus) {
+func (p *paletteSection) SetBlock(offset uint, s BlockStatus) {
 	if i, ok := p.palettesIndex[s]; ok {
 		p.directSection.SetBlock(offset, BlockStatus(i))
 		return
@@ -163,7 +166,7 @@ func (p *paletteSection) SetBlock(offset int, s BlockStatus) {
 		// Increase the underlying directSection
 		// Suppose that old bpb fit len(p.palette) before it appended.
 		// So bpb+1 must enough for new len(p.palette).
-		p.directSection = *p.directSection.clone(p.bpb + 1)
+		p.directSection = *p.directSection.clone(p.width + 1)
 	}
 	p.directSection.SetBlock(offset, BlockStatus(i))
 }

bot/world/chunk_test.go

@@ -1,78 +0,0 @@
-package world
-
-import (
-	"github.com/Tnze/go-mc/data"
-	"math/rand"
-	"testing"
-)
-
-func newDirectSection(bpb int) Section {
-	return &directSection{
-		bpb:  bpb,
-		data: make([]uint64, 16*16*16*bpb/64),
-	}
-}
-
-func TestDirectSection(t *testing.T) {
-	for bpb := 4; bpb <= data.BitsPerBlock; bpb++ {
-		testSection(newDirectSection(bpb), bpb)(t)
-	}
-}
-
-func TestDirectSection_clone(t *testing.T) {
-	s := newDirectSection(9)
-	dataset := randData(9)
-	for i := 0; i < 16*16*16; i++ {
-		s.SetBlock(i, dataset[i])
-	}
-	s = s.(*directSection).clone(data.BitsPerBlock)
-	for i := 0; i < 16*16*16; i++ {
-		if s := s.GetBlock(i); dataset[i] != s {
-			t.Fatalf("direct section error: want: %v, get %v", dataset[i], s)
-		}
-	}
-}
-
-func TestPaletteSection(t *testing.T) {
-	t.Run("Correctness", testSection(&paletteSection{
-		palettesIndex: make(map[BlockStatus]int),
-		directSection: *(newDirectSection(7).(*directSection)),
-	}, 7))
-	t.Run("AutomaticExpansion", testSection(&paletteSection{
-		palettesIndex: make(map[BlockStatus]int),
-		directSection: *(newDirectSection(4).(*directSection)),
-	}, 9))
-}
-
-func testSection(s Section, bpb int) func(t *testing.T) {
-	return func(t *testing.T) {
-		for _, dataset := range [][16 * 16 * 16]BlockStatus{secData(bpb), randData(bpb)} {
-			for i := 0; i < 16*16*16; i++ {
-				s.SetBlock(i, dataset[i])
-			}
-			for i := 0; i < 16*16*16; i++ {
-				if v := s.GetBlock(i); dataset[i] != v {
-					t.Fatalf("direct section error: want: %v, get %v", dataset[i], v)
-				}
-			}
-		}
-	}
-}
-
-func secData(bpb int) (data [16 * 16 * 16]BlockStatus) {
-	mask := 1<<bpb - 1
-	var v int
-	for i := range data {
-		data[i] = BlockStatus(v)
-		v = (v + 1) & mask
-	}
-	return
-}
-
-func randData(bpb int) (data [16 * 16 * 16]BlockStatus) {
-	data = secData(bpb)
-	rand.Shuffle(len(data), func(i, j int) {
-		data[i], data[j] = data[j], data[i]
-	})
-	return
-}

bot/world/entity/entity.go

@@ -1,20 +1,53 @@
 package entity
 
 import (
-	"github.com/Tnze/go-mc/data"
+	"bytes"
+
+	"github.com/Tnze/go-mc/data/entity"
+	item "github.com/Tnze/go-mc/data/item"
 	"github.com/Tnze/go-mc/nbt"
 	pk "github.com/Tnze/go-mc/net/packet"
+	"github.com/google/uuid"
 )
 
-//Entity is the entity of minecraft
+// BlockEntity describes the representation of a tile entity at a position.
+type BlockEntity struct {
+	ID string `nbt:"id"`
+
+	// global co-ordinates
+	X int `nbt:"x"`
+	Y int `nbt:"y"`
+	Z int `nbt:"z"`
+
+	// sign-specific.
+	Color string `nbt:"color"`
+	Text1 string `nbt:"Text1"`
+	Text2 string `nbt:"Text2"`
+	Text3 string `nbt:"Text3"`
+	Text4 string `nbt:"Text4"`
+}
+
+//Entity represents an instance of an entity.
 type Entity struct {
-	EntityID int //实体ID
+	ID   int32
+	Data int32
+	Base *entity.Entity
+
+	UUID uuid.UUID
+
+	X, Y, Z          float64
+	Pitch, Yaw       int8
+	VelX, VelY, VelZ int16
+	OnGround         bool
+
+	IsLiving  bool
+	HeadPitch int8
 }
 
 // The Slot data structure is how Minecraft represents an item and its associated data in the Minecraft Protocol
 type Slot struct {
 	Present bool
-	ItemID  int32
+	ItemID  item.ID
 	Count   int8
 	NBT     interface{}
 }
@@ -25,9 +58,11 @@ func (s *Slot) Decode(r pk.DecodeReader) error {
 		return err
 	}
 	if s.Present {
-		if err := (*pk.VarInt)(&s.ItemID).Decode(r); err != nil {
+		var itemID pk.VarInt
+		if err := itemID.Decode(r); err != nil {
 			return err
 		}
+		s.ItemID = item.ID(itemID)
 		if err := (*pk.Byte)(&s.Count).Decode(r); err != nil {
 			return err
 		}
@@ -38,6 +73,25 @@ func (s *Slot) Decode(r pk.DecodeReader) error {
 	return nil
 }
 
-func (s Slot) String() string {
+func (s Slot) Encode() []byte {
-	return data.ItemNameByID[s.ItemID]
+	if !s.Present {
+		return pk.Boolean(false).Encode()
+	}
+
+	var b bytes.Buffer
+	b.Write(pk.Boolean(true).Encode())
+	b.Write(pk.VarInt(s.ItemID).Encode())
+	b.Write(pk.Byte(s.Count).Encode())
+
+	if s.NBT != nil {
+		nbt.NewEncoder(&b).Encode(s.NBT)
+	} else {
+		b.Write([]byte{nbt.TagEnd})
+	}
+
+	return b.Bytes()
+}
+
+func (s Slot) String() string {
+	return item.ByID[item.ID(s.ItemID)].DisplayName
 }

bot/world/entity/player/player.go

@@ -2,14 +2,28 @@ package player
 
 import "github.com/Tnze/go-mc/bot/world/entity"
 
+type Pos struct {
+	X, Y, Z    float64
+	Yaw, Pitch float32
+	OnGround   bool
+}
+
+func (p Pos) PosEqual(other Pos) bool {
+	return p.X == other.X && p.Y == other.Y && p.Z == other.Z
+}
+func (p Pos) LookEqual(other Pos) bool {
+	return p.Yaw == other.Yaw && p.Pitch == other.Pitch
+}
+func (p Pos) Equal(other Pos) bool {
+	return p.PosEqual(other) && p.LookEqual(other) && p.OnGround == other.OnGround
+}
+
 // Player includes the player's status.
 type Player struct {
 	entity.Entity
 	UUID [2]int64 //128bit UUID
 
-	X, Y, Z    float64
+	Pos Pos
-	Yaw, Pitch float32
-	OnGround   bool
 
 	HeldItem int //拿着的物品栏位
 

bot/world/tile.go

@@ -0,0 +1,21 @@
+package world
+
+import (
+  "fmt"
+)
+
+// TilePosition describes the location of a tile/block entity within a chunk.
+type TilePosition uint32
+
+func (p TilePosition) Pos() (x, y, z int) {
+  return int((p>>8) & 0xff), int((p>>16) & 0xff), int(p&0xff)
+}
+
+func (p TilePosition) String() string {
+  x, y, z := p.Pos()
+  return fmt.Sprintf("(%d, %d, %d)", x, y, z)
+}
+
+func ToTilePos(x, y, z int) TilePosition {
+  return TilePosition((y&0xff) << 16 | (x&15) << 8 | (z&15))
+}

bot/world/world.go

@@ -1,77 +1,15 @@
 package world
 
 import (
+	"sync"
+
 	"github.com/Tnze/go-mc/bot/world/entity"
 )
 
 // World record all of the things in the world where player at
 type World struct {
-	Entities map[int32]entity.Entity
+	entityLock sync.RWMutex
-	Chunks   map[ChunkLoc]*Chunk
+	Entities   map[int32]*entity.Entity
-}
+	chunkLock  sync.RWMutex
-
+	Chunks     map[ChunkLoc]*Chunk
-// Chunk store a 256*16*16 column blocks
-type Chunk struct {
-	Sections [16]Section
-}
-
-// Section store a 16*16*16 cube blocks
-type Section interface {
-	// GetBlock return block status, offset can be calculate by SectionOffset.
-	GetBlock(offset int) BlockStatus
-	// SetBlock is the reverse operation of GetBlock.
-	SetBlock(offset int, s BlockStatus)
-}
-
-func SectionOffset(x, y, z int) (offset int) {
-	// According to wiki.vg: Data Array is given for each block with increasing x coordinates,
-	// within rows of increasing z coordinates, within layers of increasing y coordinates.
-	// So offset equals to ( x*16^0 + z*16^1 + y*16^2 )*(bits per block).
-	return x + z*16 + y*16*16
-}
-
-type BlockStatus uint32
-
-type ChunkLoc struct {
-	X, Z int
-}
-
-// //Entity 表示一个实体
-// type Entity interface {
-// 	EntityID() int32
-// }
-
-// //Face is a face of a block
-// type Face byte
-
-// // All six faces in a block
-// const (
-// 	Bottom Face = iota
-// 	Top
-// 	North
-// 	South
-// 	West
-// 	East
-// )
-
-// getBlock return the block in the position (x, y, z)
-func (w *World) GetBlockStatus(x, y, z int) BlockStatus {
-	// Use n>>4 rather then n/16. It acts wrong if n<0.
-	c := w.Chunks[ChunkLoc{x >> 4, z >> 4}]
-	if c != nil {
-		// (n&(16-1)) == (n<0 ? n%16+16 : n%16)
-		if sec := c.Sections[y>>4]; sec != nil {
-			return sec.GetBlock(SectionOffset(x&15, y&15, z&15))
-		}
-	}
-	return 0
-}
-
-// func (b Block) String() string {
-// 	return blockNameByID[b.id]
-// }
-
-//LoadChunk load chunk at (x, z)
-func (w *World) LoadChunk(x, z int, c *Chunk) {
-	w.Chunks[ChunkLoc{X: x, Z: z}] = c
 }

bot/world/world_chunk.go

@@ -0,0 +1,152 @@
+package world
+
+import (
+	"github.com/Tnze/go-mc/bot/world/entity"
+	"github.com/Tnze/go-mc/data/block"
+	pk "github.com/Tnze/go-mc/net/packet"
+	"github.com/Tnze/go-mc/net/ptypes"
+)
+
+// Chunk store a 256*16*16 area of blocks, sharded on the Y axis into 16
+// sections.
+type Chunk struct {
+	Sections     [16]Section
+	TileEntities map[TilePosition]entity.BlockEntity
+}
+
+// Section implements storage of blocks within a fixed 16*16*16 area.
+type Section interface {
+	// GetBlock return block status, offset can be calculate by SectionOffset.
+	GetBlock(offset uint) BlockStatus
+	// SetBlock is the reverse operation of GetBlock.
+	SetBlock(offset uint, s BlockStatus)
+}
+
+func sectionIdx(x, y, z int) uint {
+	return uint(((y & 15) << 8) | (z << 4) | x)
+}
+
+type BlockStatus uint32
+
+type ChunkLoc struct {
+	X, Z int
+}
+
+// Signs returns a list of signs on the server within viewing range.
+func (w *World) Signs() []entity.BlockEntity {
+	w.chunkLock.RLock()
+	defer w.chunkLock.RUnlock()
+
+	out := make([]entity.BlockEntity, 0, 4)
+	for _, c := range w.Chunks {
+		for _, e := range c.TileEntities {
+			if e.ID == "minecraft:sign" {
+				out = append(out, e)
+			}
+		}
+	}
+
+	return out
+}
+
+// GetBlockStatus return the state ID of the block at the given position.
+func (w *World) GetBlockStatus(x, y, z int) BlockStatus {
+	w.chunkLock.RLock()
+	defer w.chunkLock.RUnlock()
+
+	c := w.Chunks[ChunkLoc{x >> 4, z >> 4}]
+	if c != nil && y >= 0 {
+		if sec := c.Sections[y>>4]; sec != nil {
+			return sec.GetBlock(sectionIdx(x&15, y&15, z&15))
+		}
+	}
+	return 0
+}
+
+// UnloadChunk unloads a chunk from the world.
+func (w *World) UnloadChunk(loc ChunkLoc) {
+	w.chunkLock.Lock()
+	delete(w.Chunks, loc)
+	w.chunkLock.Unlock()
+}
+
+// UnaryBlockUpdate updates the block at the specified position with a new
+// state ID.
+func (w *World) UnaryBlockUpdate(pos pk.Position, bStateID BlockStatus) bool {
+	w.chunkLock.Lock()
+	defer w.chunkLock.Unlock()
+
+	c := w.Chunks[ChunkLoc{X: pos.X >> 4, Z: pos.Z >> 4}]
+	if c == nil {
+		return false
+	}
+	sIdx, bIdx := pos.Y>>4, sectionIdx(pos.X&15, pos.Y&15, pos.Z&15)
+
+	if sec := c.Sections[sIdx]; sec == nil {
+		sec = newSectionWithSize(uint(block.BitsPerBlock))
+		sec.SetBlock(bIdx, bStateID)
+		c.Sections[sIdx] = sec
+	} else {
+		tp := ToTilePos(pos.X, pos.Y, pos.Z)
+		if _, ok := c.TileEntities[tp]; ok && sec.GetBlock(bIdx) != bStateID {
+			delete(c.TileEntities, tp)
+		}
+		sec.SetBlock(bIdx, bStateID)
+	}
+	return true
+}
+
+// MultiBlockUpdate updates a packed specification of blocks within a single
+// section of a chunk.
+func (w *World) MultiBlockUpdate(loc ChunkLoc, sectionY int, blocks []pk.VarLong) bool {
+	w.chunkLock.Lock()
+	defer w.chunkLock.Unlock()
+
+	c := w.Chunks[loc]
+	if c == nil {
+		return false // not loaded
+	}
+
+	sec := c.Sections[sectionY]
+	if sec == nil {
+		sec = newSectionWithSize(uint(block.BitsPerBlock))
+		c.Sections[sectionY] = sec
+	}
+
+	for _, b := range blocks {
+		var (
+			bStateID = BlockStatus(b >> 12)
+			x, z, y  = (b >> 8) & 0xf, (b >> 4) & 0xf, b & 0xf
+			bIdx     = sectionIdx(int(x&15), int(y&15), int(z&15))
+			tp       = ToTilePos(int(x), int(y), int(z))
+		)
+		if _, ok := c.TileEntities[tp]; ok && sec.GetBlock(bIdx) != bStateID {
+			delete(c.TileEntities, tp)
+		}
+		sec.SetBlock(bIdx, bStateID)
+	}
+
+	return true
+}
+
+//LoadChunk adds the given chunk to the world.
+func (w *World) LoadChunk(x, z int, c *Chunk) {
+	w.chunkLock.Lock()
+	w.Chunks[ChunkLoc{X: x, Z: z}] = c
+	w.chunkLock.Unlock()
+}
+
+func (w *World) TileEntityUpdate(pkt ptypes.TileEntityData) error {
+	w.chunkLock.Lock()
+	defer w.chunkLock.Unlock()
+	c := w.Chunks[ChunkLoc{X: pkt.Pos.X >> 4, Z: pkt.Pos.Z >> 4}]
+	if c == nil {
+		return nil
+	}
+
+	switch pkt.Action {
+	case 9: // Sign update
+		c.TileEntities[ToTilePos(pkt.Pos.X, pkt.Pos.Y, pkt.Pos.Z)] = pkt.Data
+	}
+	return nil
+}

bot/world/world_entity.go

@@ -0,0 +1,167 @@
+package world
+
+import (
+	"fmt"
+
+	"github.com/Tnze/go-mc/bot/world/entity"
+	e "github.com/Tnze/go-mc/data/entity"
+	pk "github.com/Tnze/go-mc/net/packet"
+	"github.com/Tnze/go-mc/net/ptypes"
+	"github.com/google/uuid"
+)
+
+// PlayerEntities returns a list of players on the server within viewing range.
+func (w *World) PlayerEntities() []entity.Entity {
+	w.entityLock.RLock()
+	defer w.entityLock.RUnlock()
+	out := make([]entity.Entity, 0, 12)
+	for _, ent := range w.Entities {
+		if ent.Base.ID == e.Player.ID {
+			out = append(out, *ent)
+		}
+	}
+	return out
+}
+
+// OnSpawnEntity should be called when a SpawnEntity packet
+// is recieved.
+func (w *World) OnSpawnEntity(pkt ptypes.SpawnEntity) error {
+	w.entityLock.Lock()
+	defer w.entityLock.Unlock()
+
+	base, ok := e.ByID[e.ID(pkt.Type)]
+	if !ok {
+		return fmt.Errorf("unknown entity ID %v", pkt.Type)
+	}
+
+	w.Entities[int32(pkt.ID)] = &entity.Entity{
+		ID:    int32(pkt.ID),
+		Base:  base,
+		Data:  int32(pkt.Data),
+		UUID:  uuid.UUID(pkt.UUID),
+		X:     float64(pkt.X),
+		Y:     float64(pkt.Y),
+		Z:     float64(pkt.Z),
+		Pitch: int8(pkt.Pitch),
+		Yaw:   int8(pkt.Yaw),
+		VelX:  int16(pkt.VelX),
+		VelY:  int16(pkt.VelY),
+		VelZ:  int16(pkt.VelZ),
+	}
+
+	return nil
+}
+
+// OnSpawnLivingEntity should be called when a SpawnLivingEntity packet
+// is recieved.
+func (w *World) OnSpawnLivingEntity(pkt ptypes.SpawnLivingEntity) error {
+	w.entityLock.Lock()
+	defer w.entityLock.Unlock()
+
+	base, ok := e.ByID[e.ID(pkt.Type)]
+	if !ok {
+		return fmt.Errorf("unknown entity ID %v", pkt.Type)
+	}
+
+	// fmt.Printf("SpawnLivingEntity %q\n", base.Name)
+	w.Entities[int32(pkt.ID)] = &entity.Entity{
+		ID:        int32(pkt.ID),
+		Base:      base,
+		UUID:      uuid.UUID(pkt.UUID),
+		X:         float64(pkt.X),
+		Y:         float64(pkt.Y),
+		Z:         float64(pkt.Z),
+		Pitch:     int8(pkt.Pitch),
+		Yaw:       int8(pkt.Yaw),
+		VelX:      int16(pkt.VelX),
+		VelY:      int16(pkt.VelY),
+		VelZ:      int16(pkt.VelZ),
+		HeadPitch: int8(pkt.HeadPitch),
+	}
+	return nil
+}
+
+// OnSpawnPlayer should be called when a SpawnPlayer packet
+// is recieved.
+func (w *World) OnSpawnPlayer(pkt ptypes.SpawnPlayer) error {
+	w.entityLock.Lock()
+	defer w.entityLock.Unlock()
+
+	// fmt.Printf("SpawnPlayer %v\n", pkt)
+	w.Entities[int32(pkt.ID)] = &entity.Entity{
+		ID:    int32(pkt.ID),
+		Base:  &e.Player,
+		UUID:  uuid.UUID(pkt.UUID),
+		X:     float64(pkt.X),
+		Y:     float64(pkt.Y),
+		Z:     float64(pkt.Z),
+		Pitch: int8(pkt.Pitch),
+		Yaw:   int8(pkt.Yaw),
+	}
+	return nil
+}
+
+// OnEntityPosUpdate should be called when an EntityPosition packet
+// is recieved.
+func (w *World) OnEntityPosUpdate(pkt ptypes.EntityPosition) error {
+	w.entityLock.Lock()
+	defer w.entityLock.Unlock()
+
+	ent, ok := w.Entities[int32(pkt.ID)]
+	if !ok {
+		return fmt.Errorf("cannot handle position update for unknown entity %d", pkt.ID)
+	}
+
+	ent.X += float64(pkt.X) / (128 * 32)
+	ent.Y += float64(pkt.Y) / (128 * 32)
+	ent.Z += float64(pkt.Z) / (128 * 32)
+	ent.OnGround = bool(pkt.OnGround)
+	return nil
+}
+
+// OnEntityPosLookUpdate should be called when an EntityPositionLook packet
+// is recieved.
+func (w *World) OnEntityPosLookUpdate(pkt ptypes.EntityPositionLook) error {
+	w.entityLock.Lock()
+	defer w.entityLock.Unlock()
+
+	ent, ok := w.Entities[int32(pkt.ID)]
+	if !ok {
+		return fmt.Errorf("cannot handle position look update for unknown entity %d", pkt.ID)
+	}
+
+	ent.X += float64(pkt.X) / (128 * 32)
+	ent.Y += float64(pkt.Y) / (128 * 32)
+	ent.Z += float64(pkt.Z) / (128 * 32)
+	ent.OnGround = bool(pkt.OnGround)
+	ent.Pitch, ent.Yaw = int8(pkt.Pitch), int8(pkt.Yaw)
+	return nil
+}
+
+// OnEntityLookUpdate should be called when an EntityRotation packet
+// is recieved.
+func (w *World) OnEntityLookUpdate(pkt ptypes.EntityRotation) error {
+	w.entityLock.Lock()
+	defer w.entityLock.Unlock()
+
+	ent, ok := w.Entities[int32(pkt.ID)]
+	if !ok {
+		return fmt.Errorf("cannot handle look update for unknown entity %d", pkt.ID)
+	}
+
+	ent.Pitch, ent.Yaw = int8(pkt.Pitch), int8(pkt.Yaw)
+	ent.OnGround = bool(pkt.OnGround)
+	return nil
+}
+
+// OnEntityDestroy should be called when a DestroyEntities packet
+// is recieved.
+func (w *World) OnEntityDestroy(eIDs []pk.VarInt) error {
+	w.entityLock.Lock()
+	defer w.entityLock.Unlock()
+
+	for _, eID := range eIDs {
+		delete(w.Entities, int32(eID))
+	}
+	return nil
+}

cmd/autofish/autofish.go

@@ -1,10 +1,11 @@
 package main
 
 import (
-	"github.com/google/uuid"
 	"log"
 	"time"
 
+	"github.com/google/uuid"
+
 	"github.com/Tnze/go-mc/bot"
 	"github.com/Tnze/go-mc/chat"
 	_ "github.com/Tnze/go-mc/data/lang/en-us"

cmd/daze/daze.go

@@ -2,9 +2,10 @@ package main
 
 import (
 	"bytes"
-	"github.com/google/uuid"
 	"log"
 
+	"github.com/google/uuid"
+
 	"github.com/Tnze/go-mc/bot"
 	"github.com/Tnze/go-mc/chat"
 	_ "github.com/Tnze/go-mc/data/lang/en-us"

cmd/luncher/luncher.go

@@ -3,8 +3,9 @@ package main
 import (
 	"flag"
 	"fmt"
-	"github.com/Tnze/go-mc/yggdrasil"
 	"os"
+
+	"github.com/Tnze/go-mc/yggdrasil"
 )
 
 var user = flag.String("user", "", "Can be an email address or player name for unmigrated accounts")

cmd/simpleServer/main.go

@@ -2,12 +2,13 @@
 package main
 
 import (
+	"log"
+
 	"github.com/Tnze/go-mc/bot"
 	"github.com/Tnze/go-mc/data"
 	"github.com/Tnze/go-mc/net"
 	pk "github.com/Tnze/go-mc/net/packet"
 	"github.com/google/uuid"
-	"log"
 )
 
 const ProtocolVersion = 578
@@ -64,7 +65,7 @@ func handlePlaying(conn net.Conn, protocol int32) {
 	}
 
 	joinGame(conn)
-	conn.WritePacket(pk.Marshal(data.PlayerPositionAndLookClientbound,
+	conn.WritePacket(pk.Marshal(data.PositionClientbound,
 		// https://wiki.vg/Protocol#Player_Position_And_Look_.28clientbound.29
 		pk.Double(0), pk.Double(0), pk.Double(0), // XYZ
 		pk.Float(0), pk.Float(0), // Yaw Pitch
@@ -139,7 +140,7 @@ func loginSuccess(conn net.Conn, name string, uuid uuid.UUID) error {
 }
 
 func joinGame(conn net.Conn) error {
-	return conn.WritePacket(pk.Marshal(data.JoinGame,
+	return conn.WritePacket(pk.Marshal(data.Login,
 		pk.Int(0),                  // EntityID
 		pk.UnsignedByte(1),         // Gamemode
 		pk.Int(0),                  // Dimension

data/block/gen_blocks.go

@@ -0,0 +1,199 @@
+// gen_blocks.go generates block information.
+
+//+build ignore
+
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"go/ast"
+	"go/format"
+	"go/token"
+	"net/http"
+	"os"
+	"reflect"
+	"strconv"
+
+	"github.com/iancoleman/strcase"
+)
+
+const (
+	infoURL = "https://raw.githubusercontent.com/PrismarineJS/minecraft-data/master/data/pc/1.16.2/blocks.json"
+)
+
+type Block struct {
+	ID          uint32 `json:"id"`
+	DisplayName string `json:"displayName"`
+	Name        string `json:"name"`
+
+	Hardness   float64         `json:"hardness"`
+	Diggable   bool            `json:"diggable"`
+	DropIDs    []uint32        `json:"drops"`
+	NeedsTools map[uint32]bool `json:"harvestTools"`
+
+	MinStateID uint32 `json:"minStateId"`
+	MaxStateID uint32 `json:"maxStateId"`
+
+	Transparent      bool `json:"transparent"`
+	FilterLightLevel int  `json:"filterLight"`
+	EmitLightLevel   int  `json:"emitLight"`
+}
+
+func downloadInfo() ([]Block, error) {
+	resp, err := http.Get(infoURL)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+
+	var data []Block
+	if err := json.NewDecoder(resp.Body).Decode(&data); err != nil {
+		return nil, err
+	}
+	return data, nil
+}
+
+func makeBlockDeclaration(blocks []Block) *ast.DeclStmt {
+	out := &ast.DeclStmt{Decl: &ast.GenDecl{Tok: token.VAR}}
+
+	for _, b := range blocks {
+		t := reflect.TypeOf(b)
+		fields := make([]ast.Expr, t.NumField())
+
+		for i := 0; i < t.NumField(); i++ {
+			ft := t.Field(i)
+
+			var val ast.Expr
+			switch ft.Type.Kind() {
+			case reflect.Uint32, reflect.Int:
+				val = &ast.BasicLit{Kind: token.INT, Value: fmt.Sprint(reflect.ValueOf(b).Field(i))}
+			case reflect.Float64:
+				val = &ast.BasicLit{Kind: token.FLOAT, Value: fmt.Sprint(reflect.ValueOf(b).Field(i))}
+			case reflect.String:
+				val = &ast.BasicLit{Kind: token.STRING, Value: strconv.Quote(reflect.ValueOf(b).Field(i).String())}
+			case reflect.Bool:
+				val = &ast.BasicLit{Kind: token.IDENT, Value: fmt.Sprint(reflect.ValueOf(b).Field(i).Bool())}
+
+			case reflect.Slice:
+				val = &ast.CompositeLit{
+					Type: &ast.ArrayType{
+						Elt: &ast.BasicLit{Kind: token.IDENT, Value: ft.Type.Elem().Name()},
+					},
+				}
+				v := reflect.ValueOf(b).Field(i)
+				switch ft.Type.Elem().Kind() {
+				case reflect.Uint32, reflect.Int:
+					for x := 0; x < v.Len(); x++ {
+						val.(*ast.CompositeLit).Elts = append(val.(*ast.CompositeLit).Elts, &ast.BasicLit{
+							Kind:  token.INT,
+							Value: fmt.Sprint(v.Index(x)),
+						})
+					}
+				}
+
+			case reflect.Map:
+				// Must be the NeedsTools map of type map[uint32]bool.
+				m := &ast.CompositeLit{
+					Type: &ast.MapType{
+						Key:   &ast.BasicLit{Kind: token.IDENT, Value: ft.Type.Key().Name()},
+						Value: &ast.BasicLit{Kind: token.IDENT, Value: ft.Type.Elem().Name()},
+					},
+				}
+				iter := reflect.ValueOf(b).Field(i).MapRange()
+				for iter.Next() {
+					m.Elts = append(m.Elts, &ast.KeyValueExpr{
+						Key:   &ast.BasicLit{Kind: token.INT, Value: fmt.Sprint(iter.Key().Uint())},
+						Value: &ast.BasicLit{Kind: token.IDENT, Value: fmt.Sprint(iter.Value().Bool())},
+					})
+				}
+
+				val = m
+			}
+
+			fields[i] = &ast.KeyValueExpr{
+				Key:   &ast.Ident{Name: ft.Name},
+				Value: val,
+			}
+		}
+
+		out.Decl.(*ast.GenDecl).Specs = append(out.Decl.(*ast.GenDecl).Specs, &ast.ValueSpec{
+			Names: []*ast.Ident{{Name: strcase.ToCamel(b.Name)}},
+			Values: []ast.Expr{
+				&ast.CompositeLit{
+					Type: &ast.Ident{Name: reflect.TypeOf(b).Name()},
+					Elts: fields,
+				},
+			},
+		})
+	}
+
+	return out
+}
+
+func main() {
+	blocks, err := downloadInfo()
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Error: %v\n", err)
+		os.Exit(1)
+	}
+
+	fmt.Println(`// Package block stores information about blocks in Minecraft.
+package block
+
+import (
+	"math"
+)
+
+// BitsPerBlock indicates how many bits are needed to represent all possible
+// block states. This value is used to determine the size of the global palette.
+var BitsPerBlock = int(math.Ceil(math.Log2(float64(len(StateID)))))
+
+// ID describes the numeric ID of a block.
+type ID uint32
+
+// Block describes information about a type of block.
+type Block struct {
+	ID          ID
+	DisplayName string
+	Name        string
+
+	Hardness   float64
+	Diggable   bool
+	DropIDs    []uint32
+	NeedsTools map[uint32]bool
+
+	MinStateID uint32
+	MaxStateID uint32
+
+	Transparent      bool
+	FilterLightLevel int
+	EmitLightLevel   int
+}
+
+`)
+	format.Node(os.Stdout, token.NewFileSet(), makeBlockDeclaration(blocks))
+
+	fmt.Println()
+	fmt.Println()
+	fmt.Println("// ByID is an index of minecraft blocks by their ID.")
+	fmt.Println("var ByID = map[ID]*Block{")
+	for _, b := range blocks {
+		fmt.Printf("  %d: &%s,\n", b.ID, strcase.ToCamel(b.Name))
+	}
+	fmt.Println("}")
+
+	fmt.Println()
+	fmt.Println("// StateID maps all possible state IDs to a corresponding block ID.")
+	fmt.Println("var StateID = map[uint32]ID{")
+	for _, b := range blocks {
+		if b.MinStateID == b.MaxStateID {
+			fmt.Printf("  %d: %d,\n", b.MinStateID, b.ID)
+		} else {
+			for i := b.MinStateID; i <= b.MaxStateID; i++ {
+				fmt.Printf("  %d: %d,\n", i, b.ID)
+			}
+		}
+	}
+	fmt.Println("}")
+}

data/block/shape/gen_shape.go

@@ -0,0 +1,132 @@
+// gen_shape.go generates block shape information.
+
+//+build ignore
+
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"os"
+	"strings"
+
+	"github.com/iancoleman/strcase"
+)
+
+const (
+	infoURL = "https://raw.githubusercontent.com/PrismarineJS/minecraft-data/master/data/pc/1.16.1/blockCollisionShapes.json"
+)
+
+func downloadInfo() (map[string]interface{}, error) {
+	resp, err := http.Get(infoURL)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+
+	var data map[string]interface{}
+	if err := json.NewDecoder(resp.Body).Decode(&data); err != nil {
+		return nil, err
+	}
+	return data, nil
+}
+
+func main() {
+	info, err := downloadInfo()
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Error: %v\n", err)
+		os.Exit(1)
+	}
+
+	fmt.Println(`// Package shape stores information about the shapes of blocks in Minecraft.
+package shape
+
+import (
+  "github.com/Tnze/go-mc/bot/world"
+  "github.com/Tnze/go-mc/data/block"
+)
+
+// ID describes a numeric shape ID.
+type ID uint32
+
+// Shape describes how collisions should be tested for an object.
+type Shape struct {
+	ID    ID
+  Boxes []BoundingBox
+}
+
+type BoundingTriplet struct {
+  X, Y, Z float64
+}
+
+type BoundingBox struct {
+  Min,Max BoundingTriplet
+}
+
+// CollisionBoxes returns the set of bounding boxes for that block state ID.
+func CollisionBoxes(bStateID world.BlockStatus) ([]BoundingBox, error) {
+  bID := block.StateID[uint32(bStateID)]
+  if bID == 0 {
+    return nil, fmt.Errorf("unknown state ID: %v", bStateID)
+  }
+  b, ok := block.ByID[bID]
+  if !ok {
+    return nil, fmt.Errorf("unknown block ID: %v", bID)
+  }
+  shapes, ok := ByBlockID[bID]
+  if !ok {
+    return nil, fmt.Errorf("unknown shape for block ID: %v", bID)
+  }
+  shapeIdx := (uint32(bStateID) - b.MinStateID) % uint32(len(shapes))
+  if int(shapeIdx) > len(shapes) {
+    return nil, fmt.Errorf("shape index out of bounds: %v >= %v", shapeIdx, len(shapes))
+  }
+  return Dimensions[shapes[shapeIdx]].Boxes, nil
+}
+
+`)
+
+	fmt.Println()
+	fmt.Println()
+	fmt.Println("// ByBlockID is an index of shapes for each minecraft block variant.")
+	fmt.Println("var ByBlockID = map[block.ID][]ID{")
+	blocks := info["blocks"].(map[string]interface{})
+	for name, shapes := range blocks {
+		switch s := shapes.(type) {
+		case []interface{}:
+			set := make([]string, len(s))
+			for i := range s {
+				set[i] = fmt.Sprint(s[i])
+			}
+			fmt.Printf("  block.%s.ID: []ID{%s},\n", strcase.ToCamel(name), strings.Join(set, ", "))
+		default:
+			fmt.Printf("  block.%s.ID: []ID{%s},\n", strcase.ToCamel(name), fmt.Sprint(s))
+		}
+	}
+	fmt.Println("}")
+
+	fmt.Println()
+	fmt.Println()
+	fmt.Println("// Dimensions describes the bounding boxes of a shape ID.")
+	fmt.Println("var Dimensions = map[ID]Shape{")
+	shapes := info["shapes"].(map[string]interface{})
+	for id, boxes := range shapes {
+		fmt.Printf("  %s: Shape{\n", id)
+		fmt.Printf("    ID: %s,\n", id)
+		fmt.Printf("    Boxes: []BoundingBox{\n")
+		for _, box := range boxes.([]interface{}) {
+			elements := box.([]interface{})
+			if len(elements) != 6 {
+				panic("expected 6 elements")
+			}
+			fmt.Printf("      {\n")
+			fmt.Printf("        Min: BoundingTriplet{X: %v, Y: %v, Z: %v},\n", elements[0], elements[1], elements[2])
+			fmt.Printf("        Max: BoundingTriplet{X: %v, Y: %v, Z: %v},\n", elements[3], elements[4], elements[5])
+			fmt.Printf("      },\n")
+		}
+		fmt.Printf("    },\n")
+		fmt.Println("  },")
+	}
+	fmt.Println("}")
+}

data/entity/entity.go

@@ -0,0 +1,257 @@
+// Package entity stores information about entities in Minecraft.
+package entity
+
+// ID describes the numeric ID of an entity.
+type ID uint32
+
+// Category groups like entities.
+type Category uint8
+
+// Valid entity categories.
+const (
+	Unknown Category = iota
+	Blocks
+	Immobile
+	Vehicles
+	Drops
+	Projectiles
+	PassiveMob
+	HostileMob
+)
+
+// Entity describes information about a type of entity.
+type Entity struct {
+	ID          ID
+	InternalID  uint32
+	DisplayName string
+	Name        string
+
+	Width  float64
+	Height float64
+
+	Type     string
+	Category Category
+}
+
+var (
+	AreaEffectCloud      = Entity{ID: 0, InternalID: 0, DisplayName: "Area Effect Cloud", Name: "area_effect_cloud", Width: 6, Height: 0.5, Type: "mob", Category: Immobile}
+	ArmorStand           = Entity{ID: 1, InternalID: 1, DisplayName: "Armor Stand", Name: "armor_stand", Width: 0.5, Height: 1.975, Type: "mob", Category: Immobile}
+	Arrow                = Entity{ID: 2, InternalID: 2, DisplayName: "Arrow", Name: "arrow", Width: 0.5, Height: 0.5, Type: "mob", Category: Projectiles}
+	Bat                  = Entity{ID: 3, InternalID: 3, DisplayName: "Bat", Name: "bat", Width: 0.5, Height: 0.9, Type: "mob", Category: PassiveMob}
+	Bee                  = Entity{ID: 4, InternalID: 4, DisplayName: "Bee", Name: "bee", Width: 0.7, Height: 0.6, Type: "UNKNOWN", Category: Unknown}
+	Blaze                = Entity{ID: 5, InternalID: 5, DisplayName: "Blaze", Name: "blaze", Width: 0.6, Height: 1.8, Type: "mob", Category: HostileMob}
+	Boat                 = Entity{ID: 6, InternalID: 6, DisplayName: "Boat", Name: "boat", Width: 1.375, Height: 0.5625, Type: "mob", Category: Vehicles}
+	Cat                  = Entity{ID: 7, InternalID: 7, DisplayName: "Cat", Name: "cat", Width: 0.6, Height: 0.7, Type: "mob", Category: PassiveMob}
+	CaveSpider           = Entity{ID: 8, InternalID: 8, DisplayName: "Cave Spider", Name: "cave_spider", Width: 0.7, Height: 0.5, Type: "mob", Category: HostileMob}
+	Chicken              = Entity{ID: 9, InternalID: 9, DisplayName: "Chicken", Name: "chicken", Width: 0.4, Height: 0.7, Type: "mob", Category: PassiveMob}
+	Cod                  = Entity{ID: 10, InternalID: 10, DisplayName: "Cod", Name: "cod", Width: 0.5, Height: 0.3, Type: "mob", Category: PassiveMob}
+	Cow                  = Entity{ID: 11, InternalID: 11, DisplayName: "Cow", Name: "cow", Width: 0.9, Height: 1.4, Type: "mob", Category: PassiveMob}
+	Creeper              = Entity{ID: 12, InternalID: 12, DisplayName: "Creeper", Name: "creeper", Width: 0.6, Height: 1.7, Type: "mob", Category: HostileMob}
+	Dolphin              = Entity{ID: 13, InternalID: 13, DisplayName: "Dolphin", Name: "dolphin", Width: 0.9, Height: 0.6, Type: "mob", Category: PassiveMob}
+	Donkey               = Entity{ID: 14, InternalID: 14, DisplayName: "Donkey", Name: "donkey", Width: 1.39648, Height: 1.5, Type: "mob", Category: PassiveMob}
+	DragonFireball       = Entity{ID: 15, InternalID: 15, DisplayName: "Dragon Fireball", Name: "dragon_fireball", Width: 1, Height: 1, Type: "mob", Category: Projectiles}
+	Drowned              = Entity{ID: 16, InternalID: 16, DisplayName: "Drowned", Name: "drowned", Width: 0.6, Height: 1.95, Type: "mob", Category: HostileMob}
+	ElderGuardian        = Entity{ID: 17, InternalID: 17, DisplayName: "Elder Guardian", Name: "elder_guardian", Width: 1.9975, Height: 1.9975, Type: "mob", Category: HostileMob}
+	EndCrystal           = Entity{ID: 18, InternalID: 18, DisplayName: "End Crystal", Name: "end_crystal", Width: 2, Height: 2, Type: "mob", Category: Unknown}
+	EnderDragon          = Entity{ID: 19, InternalID: 19, DisplayName: "Ender Dragon", Name: "ender_dragon", Width: 16, Height: 8, Type: "mob", Category: HostileMob}
+	Enderman             = Entity{ID: 20, InternalID: 20, DisplayName: "Enderman", Name: "enderman", Width: 0.6, Height: 2.9, Type: "mob", Category: HostileMob}
+	Endermite            = Entity{ID: 21, InternalID: 21, DisplayName: "Endermite", Name: "endermite", Width: 0.4, Height: 0.3, Type: "mob", Category: HostileMob}
+	Evoker               = Entity{ID: 22, InternalID: 22, DisplayName: "Evoker", Name: "evoker", Width: 0.6, Height: 1.95, Type: "mob", Category: HostileMob}
+	EvokerFangs          = Entity{ID: 23, InternalID: 23, DisplayName: "Evoker Fangs", Name: "evoker_fangs", Width: 0.5, Height: 0.8, Type: "mob", Category: HostileMob}
+	ExperienceOrb        = Entity{ID: 24, InternalID: 24, DisplayName: "Experience Orb", Name: "experience_orb", Width: 0.5, Height: 0.5, Type: "mob", Category: Unknown}
+	EyeOfEnder           = Entity{ID: 25, InternalID: 25, DisplayName: "Eye of Ender", Name: "eye_of_ender", Width: 0.25, Height: 0.25, Type: "mob", Category: Unknown}
+	FallingBlock         = Entity{ID: 26, InternalID: 26, DisplayName: "Falling Block", Name: "falling_block", Width: 0.98, Height: 0.98, Type: "mob", Category: Blocks}
+	FireworkRocket       = Entity{ID: 27, InternalID: 27, DisplayName: "Firework Rocket", Name: "firework_rocket", Width: 0.25, Height: 0.25, Type: "mob", Category: Unknown}
+	Fox                  = Entity{ID: 28, InternalID: 28, DisplayName: "Fox", Name: "fox", Width: 0.6, Height: 0.7, Type: "mob", Category: Unknown}
+	Ghast                = Entity{ID: 29, InternalID: 29, DisplayName: "Ghast", Name: "ghast", Width: 4, Height: 4, Type: "mob", Category: HostileMob}
+	Giant                = Entity{ID: 30, InternalID: 30, DisplayName: "Giant", Name: "giant", Width: 3.6, Height: 12, Type: "mob", Category: HostileMob}
+	Guardian             = Entity{ID: 31, InternalID: 31, DisplayName: "Guardian", Name: "guardian", Width: 0.85, Height: 0.85, Type: "mob", Category: HostileMob}
+	Hoglin               = Entity{ID: 32, InternalID: 32, DisplayName: "Hoglin", Name: "hoglin", Width: 1.39648, Height: 1.4, Type: "UNKNOWN", Category: Unknown}
+	Horse                = Entity{ID: 33, InternalID: 33, DisplayName: "Horse", Name: "horse", Width: 1.39648, Height: 1.6, Type: "mob", Category: PassiveMob}
+	Husk                 = Entity{ID: 34, InternalID: 34, DisplayName: "Husk", Name: "husk", Width: 0.6, Height: 1.95, Type: "mob", Category: HostileMob}
+	Illusioner           = Entity{ID: 35, InternalID: 35, DisplayName: "Illusioner", Name: "illusioner", Width: 0.6, Height: 1.95, Type: "mob", Category: HostileMob}
+	IronGolem            = Entity{ID: 36, InternalID: 36, DisplayName: "Iron Golem", Name: "iron_golem", Width: 1.4, Height: 2.7, Type: "mob", Category: PassiveMob}
+	Item                 = Entity{ID: 37, InternalID: 37, DisplayName: "Item", Name: "item", Width: 0.25, Height: 0.25, Type: "mob", Category: Drops}
+	ItemFrame            = Entity{ID: 38, InternalID: 38, DisplayName: "Item Frame", Name: "item_frame", Width: 0.5, Height: 0.5, Type: "mob", Category: Immobile}
+	Fireball             = Entity{ID: 39, InternalID: 39, DisplayName: "Fireball", Name: "fireball", Width: 1, Height: 1, Type: "mob", Category: Projectiles}
+	LeashKnot            = Entity{ID: 40, InternalID: 40, DisplayName: "Leash Knot", Name: "leash_knot", Width: 0.5, Height: 0.5, Type: "mob", Category: Immobile}
+	LightningBolt        = Entity{ID: 41, InternalID: 41, DisplayName: "Lightning Bolt", Name: "lightning_bolt", Width: 0, Height: 0, Type: "mob", Category: Unknown}
+	Llama                = Entity{ID: 42, InternalID: 42, DisplayName: "Llama", Name: "llama", Width: 0.9, Height: 1.87, Type: "mob", Category: PassiveMob}
+	LlamaSpit            = Entity{ID: 43, InternalID: 43, DisplayName: "Llama Spit", Name: "llama_spit", Width: 0.25, Height: 0.25, Type: "mob", Category: Projectiles}
+	MagmaCube            = Entity{ID: 44, InternalID: 44, DisplayName: "Magma Cube", Name: "magma_cube", Width: 2.04, Height: 2.04, Type: "mob", Category: HostileMob}
+	Minecart             = Entity{ID: 45, InternalID: 45, DisplayName: "Minecart", Name: "minecart", Width: 0.98, Height: 0.7, Type: "mob", Category: Vehicles}
+	ChestMinecart        = Entity{ID: 46, InternalID: 46, DisplayName: "Minecart with Chest", Name: "chest_minecart", Width: 0.98, Height: 0.7, Type: "mob", Category: Vehicles}
+	CommandBlockMinecart = Entity{ID: 47, InternalID: 47, DisplayName: "Minecart with Command Block", Name: "command_block_minecart", Width: 0.98, Height: 0.7, Type: "mob", Category: Vehicles}
+	FurnaceMinecart      = Entity{ID: 48, InternalID: 48, DisplayName: "Minecart with Furnace", Name: "furnace_minecart", Width: 0.98, Height: 0.7, Type: "mob", Category: Vehicles}
+	HopperMinecart       = Entity{ID: 49, InternalID: 49, DisplayName: "Minecart with Hopper", Name: "hopper_minecart", Width: 0.98, Height: 0.7, Type: "mob", Category: Vehicles}
+	SpawnerMinecart      = Entity{ID: 50, InternalID: 50, DisplayName: "Minecart with Spawner", Name: "spawner_minecart", Width: 0.98, Height: 0.7, Type: "mob", Category: Vehicles}
+	TntMinecart          = Entity{ID: 51, InternalID: 51, DisplayName: "Minecart with TNT", Name: "tnt_minecart", Width: 0.98, Height: 0.7, Type: "mob", Category: Vehicles}
+	Mule                 = Entity{ID: 52, InternalID: 52, DisplayName: "Mule", Name: "mule", Width: 1.39648, Height: 1.6, Type: "mob", Category: PassiveMob}
+	Mooshroom            = Entity{ID: 53, InternalID: 53, DisplayName: "Mooshroom", Name: "mooshroom", Width: 0.9, Height: 1.4, Type: "mob", Category: PassiveMob}
+	Ocelot               = Entity{ID: 54, InternalID: 54, DisplayName: "Ocelot", Name: "ocelot", Width: 0.6, Height: 0.7, Type: "mob", Category: PassiveMob}
+	Painting             = Entity{ID: 55, InternalID: 55, DisplayName: "Painting", Name: "painting", Width: 0.5, Height: 0.5, Type: "mob", Category: Immobile}
+	Panda                = Entity{ID: 56, InternalID: 56, DisplayName: "Panda", Name: "panda", Width: 1.3, Height: 1.25, Type: "mob", Category: PassiveMob}
+	Parrot               = Entity{ID: 57, InternalID: 57, DisplayName: "Parrot", Name: "parrot", Width: 0.5, Height: 0.9, Type: "mob", Category: PassiveMob}
+	Phantom              = Entity{ID: 58, InternalID: 58, DisplayName: "Phantom", Name: "phantom", Width: 0.9, Height: 0.5, Type: "mob", Category: HostileMob}
+	Pig                  = Entity{ID: 59, InternalID: 59, DisplayName: "Pig", Name: "pig", Width: 0.9, Height: 0.9, Type: "mob", Category: PassiveMob}
+	Piglin               = Entity{ID: 60, InternalID: 60, DisplayName: "Piglin", Name: "piglin", Width: 0.6, Height: 1.95, Type: "UNKNOWN", Category: Unknown}
+	PiglinBrute          = Entity{ID: 61, InternalID: 61, DisplayName: "Piglin Brute", Name: "piglin_brute", Width: 0.6, Height: 1.95, Type: "UNKNOWN", Category: Unknown}
+	Pillager             = Entity{ID: 62, InternalID: 62, DisplayName: "Pillager", Name: "pillager", Width: 0.6, Height: 1.95, Type: "mob", Category: HostileMob}
+	PolarBear            = Entity{ID: 63, InternalID: 63, DisplayName: "Polar Bear", Name: "polar_bear", Width: 1.4, Height: 1.4, Type: "mob", Category: PassiveMob}
+	Tnt                  = Entity{ID: 64, InternalID: 64, DisplayName: "Primed TNT", Name: "tnt", Width: 0.98, Height: 0.98, Type: "mob", Category: Blocks}
+	Pufferfish           = Entity{ID: 65, InternalID: 65, DisplayName: "Pufferfish", Name: "pufferfish", Width: 0.7, Height: 0.7, Type: "mob", Category: PassiveMob}
+	Rabbit               = Entity{ID: 66, InternalID: 66, DisplayName: "Rabbit", Name: "rabbit", Width: 0.4, Height: 0.5, Type: "mob", Category: PassiveMob}
+	Ravager              = Entity{ID: 67, InternalID: 67, DisplayName: "Ravager", Name: "ravager", Width: 1.95, Height: 2.2, Type: "mob", Category: HostileMob}
+	Salmon               = Entity{ID: 68, InternalID: 68, DisplayName: "Salmon", Name: "salmon", Width: 0.7, Height: 0.4, Type: "mob", Category: PassiveMob}
+	Sheep                = Entity{ID: 69, InternalID: 69, DisplayName: "Sheep", Name: "sheep", Width: 0.9, Height: 1.3, Type: "mob", Category: PassiveMob}
+	Shulker              = Entity{ID: 70, InternalID: 70, DisplayName: "Shulker", Name: "shulker", Width: 1, Height: 1, Type: "mob", Category: HostileMob}
+	ShulkerBullet        = Entity{ID: 71, InternalID: 71, DisplayName: "Shulker Bullet", Name: "shulker_bullet", Width: 0.3125, Height: 0.3125, Type: "mob", Category: Projectiles}
+	Silverfish           = Entity{ID: 72, InternalID: 72, DisplayName: "Silverfish", Name: "silverfish", Width: 0.4, Height: 0.3, Type: "mob", Category: HostileMob}
+	Skeleton             = Entity{ID: 73, InternalID: 73, DisplayName: "Skeleton", Name: "skeleton", Width: 0.6, Height: 1.99, Type: "mob", Category: HostileMob}
+	SkeletonHorse        = Entity{ID: 74, InternalID: 74, DisplayName: "Skeleton Horse", Name: "skeleton_horse", Width: 1.39648, Height: 1.6, Type: "mob", Category: PassiveMob}
+	Slime                = Entity{ID: 75, InternalID: 75, DisplayName: "Slime", Name: "slime", Width: 2.04, Height: 2.04, Type: "mob", Category: HostileMob}
+	SmallFireball        = Entity{ID: 76, InternalID: 76, DisplayName: "Small Fireball", Name: "small_fireball", Width: 0.3125, Height: 0.3125, Type: "mob", Category: Projectiles}
+	SnowGolem            = Entity{ID: 77, InternalID: 77, DisplayName: "Snow Golem", Name: "snow_golem", Width: 0.7, Height: 1.9, Type: "mob", Category: PassiveMob}
+	Snowball             = Entity{ID: 78, InternalID: 78, DisplayName: "Snowball", Name: "snowball", Width: 0.25, Height: 0.25, Type: "mob", Category: Projectiles}
+	SpectralArrow        = Entity{ID: 79, InternalID: 79, DisplayName: "Spectral Arrow", Name: "spectral_arrow", Width: 0.5, Height: 0.5, Type: "mob", Category: Projectiles}
+	Spider               = Entity{ID: 80, InternalID: 80, DisplayName: "Spider", Name: "spider", Width: 1.4, Height: 0.9, Type: "mob", Category: HostileMob}
+	Squid                = Entity{ID: 81, InternalID: 81, DisplayName: "Squid", Name: "squid", Width: 0.8, Height: 0.8, Type: "mob", Category: PassiveMob}
+	Stray                = Entity{ID: 82, InternalID: 82, DisplayName: "Stray", Name: "stray", Width: 0.6, Height: 1.99, Type: "mob", Category: HostileMob}
+	Strider              = Entity{ID: 83, InternalID: 83, DisplayName: "Strider", Name: "strider", Width: 0.9, Height: 1.7, Type: "UNKNOWN", Category: Unknown}
+	Egg                  = Entity{ID: 84, InternalID: 84, DisplayName: "Thrown Egg", Name: "egg", Width: 0.25, Height: 0.25, Type: "mob", Category: Projectiles}
+	EnderPearl           = Entity{ID: 85, InternalID: 85, DisplayName: "Thrown Ender Pearl", Name: "ender_pearl", Width: 0.25, Height: 0.25, Type: "mob", Category: Projectiles}
+	ExperienceBottle     = Entity{ID: 86, InternalID: 86, DisplayName: "Thrown Bottle o' Enchanting", Name: "experience_bottle", Width: 0.25, Height: 0.25, Type: "mob", Category: Unknown}
+	Potion               = Entity{ID: 87, InternalID: 87, DisplayName: "Potion", Name: "potion", Width: 0.25, Height: 0.25, Type: "mob", Category: Projectiles}
+	Trident              = Entity{ID: 88, InternalID: 88, DisplayName: "Trident", Name: "trident", Width: 0.5, Height: 0.5, Type: "mob", Category: Unknown}
+	TraderLlama          = Entity{ID: 89, InternalID: 89, DisplayName: "Trader Llama", Name: "trader_llama", Width: 0.9, Height: 1.87, Type: "mob", Category: PassiveMob}
+	TropicalFish         = Entity{ID: 90, InternalID: 90, DisplayName: "Tropical Fish", Name: "tropical_fish", Width: 0.5, Height: 0.4, Type: "mob", Category: PassiveMob}
+	Turtle               = Entity{ID: 91, InternalID: 91, DisplayName: "Turtle", Name: "turtle", Width: 1.2, Height: 0.4, Type: "mob", Category: PassiveMob}
+	Vex                  = Entity{ID: 92, InternalID: 92, DisplayName: "Vex", Name: "vex", Width: 0.4, Height: 0.8, Type: "mob", Category: HostileMob}
+	Villager             = Entity{ID: 93, InternalID: 93, DisplayName: "Villager", Name: "villager", Width: 0.6, Height: 1.95, Type: "mob", Category: PassiveMob}
+	Vindicator           = Entity{ID: 94, InternalID: 94, DisplayName: "Vindicator", Name: "vindicator", Width: 0.6, Height: 1.95, Type: "mob", Category: HostileMob}
+	WanderingTrader      = Entity{ID: 95, InternalID: 95, DisplayName: "Wandering Trader", Name: "wandering_trader", Width: 0.6, Height: 1.95, Type: "mob", Category: PassiveMob}
+	Witch                = Entity{ID: 96, InternalID: 96, DisplayName: "Witch", Name: "witch", Width: 0.6, Height: 1.95, Type: "mob", Category: HostileMob}
+	Wither               = Entity{ID: 97, InternalID: 97, DisplayName: "Wither", Name: "wither", Width: 0.9, Height: 3.5, Type: "mob", Category: HostileMob}
+	WitherSkeleton       = Entity{ID: 98, InternalID: 98, DisplayName: "Wither Skeleton", Name: "wither_skeleton", Width: 0.7, Height: 2.4, Type: "mob", Category: HostileMob}
+	WitherSkull          = Entity{ID: 99, InternalID: 99, DisplayName: "Wither Skull", Name: "wither_skull", Width: 0.3125, Height: 0.3125, Type: "mob", Category: Projectiles}
+	Wolf                 = Entity{ID: 100, InternalID: 100, DisplayName: "Wolf", Name: "wolf", Width: 0.6, Height: 0.85, Type: "mob", Category: PassiveMob}
+	Zoglin               = Entity{ID: 101, InternalID: 101, DisplayName: "Zoglin", Name: "zoglin", Width: 1.39648, Height: 1.4, Type: "UNKNOWN", Category: Unknown}
+	Zombie               = Entity{ID: 102, InternalID: 102, DisplayName: "Zombie", Name: "zombie", Width: 0.6, Height: 1.95, Type: "mob", Category: HostileMob}
+	ZombieHorse          = Entity{ID: 103, InternalID: 103, DisplayName: "Zombie Horse", Name: "zombie_horse", Width: 1.39648, Height: 1.6, Type: "mob", Category: PassiveMob}
+	ZombieVillager       = Entity{ID: 104, InternalID: 104, DisplayName: "Zombie Villager", Name: "zombie_villager", Width: 0.6, Height: 1.95, Type: "mob", Category: HostileMob}
+	ZombifiedPiglin      = Entity{ID: 105, InternalID: 105, DisplayName: "Zombified Piglin", Name: "zombified_piglin", Width: 0.6, Height: 1.95, Type: "UNKNOWN", Category: Unknown}
+	Player               = Entity{ID: 106, InternalID: 106, DisplayName: "Player", Name: "player", Width: 0.6, Height: 1.8, Type: "mob", Category: Unknown}
+	FishingBobber        = Entity{ID: 107, InternalID: 107, DisplayName: "Fishing Bobber", Name: "fishing_bobber", Width: 0.25, Height: 0.25, Type: "mob", Category: Unknown}
+)
+
+// ByID is an index of minecraft entities by their ID.
+var ByID = map[ID]*Entity{
+	0:   &AreaEffectCloud,
+	1:   &ArmorStand,
+	2:   &Arrow,
+	3:   &Bat,
+	4:   &Bee,
+	5:   &Blaze,
+	6:   &Boat,
+	7:   &Cat,
+	8:   &CaveSpider,
+	9:   &Chicken,
+	10:  &Cod,
+	11:  &Cow,
+	12:  &Creeper,
+	13:  &Dolphin,
+	14:  &Donkey,
+	15:  &DragonFireball,
+	16:  &Drowned,
+	17:  &ElderGuardian,
+	18:  &EndCrystal,
+	19:  &EnderDragon,
+	20:  &Enderman,
+	21:  &Endermite,
+	22:  &Evoker,
+	23:  &EvokerFangs,
+	24:  &ExperienceOrb,
+	25:  &EyeOfEnder,
+	26:  &FallingBlock,
+	27:  &FireworkRocket,
+	28:  &Fox,
+	29:  &Ghast,
+	30:  &Giant,
+	31:  &Guardian,
+	32:  &Hoglin,
+	33:  &Horse,
+	34:  &Husk,
+	35:  &Illusioner,
+	36:  &IronGolem,
+	37:  &Item,
+	38:  &ItemFrame,
+	39:  &Fireball,
+	40:  &LeashKnot,
+	41:  &LightningBolt,
+	42:  &Llama,
+	43:  &LlamaSpit,
+	44:  &MagmaCube,
+	45:  &Minecart,
+	46:  &ChestMinecart,
+	47:  &CommandBlockMinecart,
+	48:  &FurnaceMinecart,
+	49:  &HopperMinecart,
+	50:  &SpawnerMinecart,
+	51:  &TntMinecart,
+	52:  &Mule,
+	53:  &Mooshroom,
+	54:  &Ocelot,
+	55:  &Painting,
+	56:  &Panda,
+	57:  &Parrot,
+	58:  &Phantom,
+	59:  &Pig,
+	60:  &Piglin,
+	61:  &PiglinBrute,
+	62:  &Pillager,
+	63:  &PolarBear,
+	64:  &Tnt,
+	65:  &Pufferfish,
+	66:  &Rabbit,
+	67:  &Ravager,
+	68:  &Salmon,
+	69:  &Sheep,
+	70:  &Shulker,
+	71:  &ShulkerBullet,
+	72:  &Silverfish,
+	73:  &Skeleton,
+	74:  &SkeletonHorse,
+	75:  &Slime,
+	76:  &SmallFireball,
+	77:  &SnowGolem,
+	78:  &Snowball,
+	79:  &SpectralArrow,
+	80:  &Spider,
+	81:  &Squid,
+	82:  &Stray,
+	83:  &Strider,
+	84:  &Egg,
+	85:  &EnderPearl,
+	86:  &ExperienceBottle,
+	87:  &Potion,
+	88:  &Trident,
+	89:  &TraderLlama,
+	90:  &TropicalFish,
+	91:  &Turtle,
+	92:  &Vex,
+	93:  &Villager,
+	94:  &Vindicator,
+	95:  &WanderingTrader,
+	96:  &Witch,
+	97:  &Wither,
+	98:  &WitherSkeleton,
+	99:  &WitherSkull,
+	100: &Wolf,
+	101: &Zoglin,
+	102: &Zombie,
+	103: &ZombieHorse,
+	104: &ZombieVillager,
+	105: &ZombifiedPiglin,
+	106: &Player,
+	107: &FishingBobber,
+}

data/entity/gen_entity.go

@@ -0,0 +1,184 @@
+// gen_entity.go generates entity information.
+
+//+build ignore
+
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"go/ast"
+	"go/format"
+	"go/token"
+	"net/http"
+	"os"
+	"reflect"
+	"strconv"
+
+	"github.com/iancoleman/strcase"
+)
+
+const (
+	infoURL = "https://raw.githubusercontent.com/PrismarineJS/minecraft-data/master/data/pc/1.16.2/entities.json"
+)
+
+type Entity struct {
+	ID          uint32 `json:"id"`
+	InternalID  uint32 `json:"internalId"`
+	DisplayName string `json:"displayName"`
+	Name        string `json:"name"`
+
+	Width  float64 `json:"width"`
+	Height float64 `json:"height"`
+
+	Type     string `json:"type"`
+	Category string `json:"category"`
+}
+
+func downloadInfo() ([]Entity, error) {
+	resp, err := http.Get(infoURL)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+
+	var data []Entity
+	if err := json.NewDecoder(resp.Body).Decode(&data); err != nil {
+		return nil, err
+	}
+	return data, nil
+}
+
+func makeEntityDeclaration(entities []Entity) *ast.DeclStmt {
+	out := &ast.DeclStmt{Decl: &ast.GenDecl{Tok: token.VAR}}
+
+	for _, e := range entities {
+		t := reflect.TypeOf(e)
+		fields := make([]ast.Expr, t.NumField())
+
+		for i := 0; i < t.NumField(); i++ {
+			ft := t.Field(i)
+
+			if ft.Name == "Category" {
+				val := &ast.BasicLit{Kind: token.IDENT, Value: "Unknown"}
+				switch e.Category {
+				case "Passive mobs":
+					val.Value = "PassiveMob"
+				case "Hostile mobs":
+					val.Value = "HostileMob"
+				case "UNKNOWN":
+				default:
+					val.Value = e.Category
+				}
+				fields[i] = &ast.KeyValueExpr{
+					Key:   &ast.Ident{Name: ft.Name},
+					Value: val,
+				}
+				continue
+			}
+
+			var val ast.Expr
+			switch ft.Type.Kind() {
+			case reflect.Uint32, reflect.Int:
+				val = &ast.BasicLit{Kind: token.INT, Value: fmt.Sprint(reflect.ValueOf(e).Field(i))}
+			case reflect.Float64:
+				val = &ast.BasicLit{Kind: token.FLOAT, Value: fmt.Sprint(reflect.ValueOf(e).Field(i))}
+			case reflect.String:
+				val = &ast.BasicLit{Kind: token.STRING, Value: strconv.Quote(reflect.ValueOf(e).Field(i).String())}
+			case reflect.Bool:
+				val = &ast.BasicLit{Kind: token.IDENT, Value: fmt.Sprint(reflect.ValueOf(e).Field(i).Bool())}
+
+			case reflect.Slice:
+				val = &ast.CompositeLit{
+					Type: &ast.ArrayType{
+						Elt: &ast.BasicLit{Kind: token.IDENT, Value: ft.Type.Elem().Name()},
+					},
+				}
+				v := reflect.ValueOf(e).Field(i)
+				switch ft.Type.Elem().Kind() {
+				case reflect.Uint32, reflect.Int:
+					for x := 0; x < v.Len(); x++ {
+						val.(*ast.CompositeLit).Elts = append(val.(*ast.CompositeLit).Elts, &ast.BasicLit{
+							Kind:  token.INT,
+							Value: fmt.Sprint(v.Index(x)),
+						})
+					}
+				}
+			}
+
+			fields[i] = &ast.KeyValueExpr{
+				Key:   &ast.Ident{Name: ft.Name},
+				Value: val,
+			}
+		}
+
+		out.Decl.(*ast.GenDecl).Specs = append(out.Decl.(*ast.GenDecl).Specs, &ast.ValueSpec{
+			Names: []*ast.Ident{{Name: strcase.ToCamel(e.Name)}},
+			Values: []ast.Expr{
+				&ast.CompositeLit{
+					Type: &ast.Ident{Name: reflect.TypeOf(e).Name()},
+					Elts: fields,
+				},
+			},
+		})
+	}
+
+	return out
+}
+
+func main() {
+	entities, err := downloadInfo()
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Error: %v\n", err)
+		os.Exit(1)
+	}
+
+	fmt.Println(`// Package entity stores information about entities in Minecraft.
+package entity
+
+// ID describes the numeric ID of an entity.
+type ID uint32
+
+// Category groups like entities.
+type Category uint8
+
+// Valid entity categories.
+const (
+	Unknown Category = iota
+	Blocks
+	Immobile
+	Vehicles
+	Drops
+	Projectiles
+	PassiveMob
+	HostileMob
+)
+
+// Entity describes information about a type of entity.
+type Entity struct {
+	ID          ID
+	InternalID  uint32
+	DisplayName string
+	Name        string
+
+	Width  float64
+	Height float64
+
+	Type     string
+	Category Category
+}
+
+`)
+	format.Node(os.Stdout, token.NewFileSet(), makeEntityDeclaration(entities))
+
+	fmt.Println()
+	fmt.Println()
+	fmt.Println("// ByID is an index of minecraft entities by their ID.")
+	fmt.Println("var ByID = map[ID]*Entity{")
+	for _, e := range entities {
+		fmt.Printf("  %d: &%s,\n", e.ID, strcase.ToCamel(e.Name))
+	}
+	fmt.Println("}")
+
+	fmt.Println()
+}

data/gen_packetIDs.go

@@ -0,0 +1,196 @@
+// gen_packetIDs.go generates the enumeration of packet IDs used on the wire.
+
+//+build ignore
+
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"os"
+	"strings"
+
+	"github.com/iancoleman/strcase"
+)
+
+const (
+	protocolURL = "https://raw.githubusercontent.com/PrismarineJS/minecraft-data/master/data/pc/1.16.2/protocol.json"
+)
+
+// unnest is a utility function to unpack a value from a nested map, given
+// an arbitrary set of keys to reach through.
+func unnest(input map[string]interface{}, keys ...string) (map[string]interface{}, error) {
+	for _, k := range keys {
+		sub, ok := input[k]
+		if !ok {
+			return nil, fmt.Errorf("key %q not found", k)
+		}
+		next, ok := sub.(map[string]interface{})
+		if !ok {
+			return nil, fmt.Errorf("key %q was %T, expected a string map", k, sub)
+		}
+		input = next
+	}
+	return input, nil
+}
+
+type duplexMappings struct {
+	Clientbound map[string]string
+	Serverbound map[string]string
+}
+
+func (m *duplexMappings) EnsureUniqueNames() {
+	// Assemble a slice of keys to check across both maps, because we cannot
+	// mutate a map while iterating it.
+	clientKeys := make([]string, 0, len(m.Clientbound))
+	for k, _ := range m.Clientbound {
+		clientKeys = append(clientKeys, k)
+	}
+
+	for _, k := range clientKeys {
+		if _, alsoServerKey := m.Serverbound[k]; alsoServerKey {
+			cVal, sVal := m.Clientbound[k], m.Serverbound[k]
+			delete(m.Clientbound, k)
+			delete(m.Serverbound, k)
+			m.Clientbound[k+"Clientbound"] = cVal
+			m.Serverbound[k+"Serverbound"] = sVal
+		}
+	}
+}
+
+// unpackMapping returns the set of packet IDs and their names for a given
+// game state.
+func unpackMapping(data map[string]interface{}, gameState string) (duplexMappings, error) {
+	out := duplexMappings{
+		Clientbound: make(map[string]string),
+		Serverbound: make(map[string]string),
+	}
+
+	info, err := unnest(data, gameState, "toClient", "types")
+	if err != nil {
+		return duplexMappings{}, err
+	}
+	pType := info["packet"].([]interface{})[1].([]interface{})[0].(map[string]interface{})["type"]
+	mappings := pType.([]interface{})[1].(map[string]interface{})["mappings"].(map[string]interface{})
+	for k, v := range mappings {
+		out.Clientbound[strcase.ToCamel(v.(string))] = k
+	}
+	info, err = unnest(data, gameState, "toServer", "types")
+	if err != nil {
+		return duplexMappings{}, err
+	}
+	pType = info["packet"].([]interface{})[1].([]interface{})[0].(map[string]interface{})["type"]
+	mappings = pType.([]interface{})[1].(map[string]interface{})["mappings"].(map[string]interface{})
+	for k, v := range mappings {
+		out.Serverbound[strcase.ToCamel(v.(string))] = k
+	}
+
+	return out, nil
+}
+
+type protocolIDs struct {
+	Login  duplexMappings
+	Play   duplexMappings
+	Status duplexMappings
+	// Handshake state has no packets
+}
+
+func (p protocolIDs) MaxLen() int {
+	var max int
+	for _, m := range []duplexMappings{p.Login, p.Play, p.Status} {
+		for k, _ := range m.Clientbound {
+			if len(k) > max {
+				max = len(k)
+			}
+		}
+		for k, _ := range m.Serverbound {
+			if len(k) > max {
+				max = len(k)
+			}
+		}
+	}
+	return max
+}
+
+func downloadInfo() (*protocolIDs, error) {
+	resp, err := http.Get(protocolURL)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+	var data map[string]interface{}
+	if err := json.NewDecoder(resp.Body).Decode(&data); err != nil {
+		return nil, err
+	}
+
+	var out protocolIDs
+	if out.Login, err = unpackMapping(data, "login"); err != nil {
+		return nil, fmt.Errorf("login: %v", err)
+	}
+	out.Login.EnsureUniqueNames()
+	if out.Play, err = unpackMapping(data, "play"); err != nil {
+		return nil, fmt.Errorf("play: %v", err)
+	}
+	out.Play.EnsureUniqueNames()
+	if out.Status, err = unpackMapping(data, "status"); err != nil {
+		return nil, fmt.Errorf("play: %v", err)
+	}
+	out.Status.EnsureUniqueNames()
+
+	return &out, nil
+}
+
+func main() {
+	pIDs, err := downloadInfo()
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Error: %v\n", err)
+		os.Exit(1)
+	}
+
+	maxLen := pIDs.MaxLen()
+
+	fmt.Println("package data")
+	fmt.Println()
+	fmt.Println("//go:generate bash -c \"go run gen_packetIDs.go > packetIDs.go\"")
+	fmt.Println()
+	fmt.Println("// This file is automatically generated by gen_packetIDs.go. DO NOT EDIT.")
+	fmt.Println()
+	fmt.Println("// PktID represents a packet ID used in the minecraft protocol.")
+	fmt.Println("type PktID int32")
+	fmt.Println()
+	fmt.Println("// Valid PktID values.")
+	fmt.Println("const (")
+
+	fmt.Println("  // Clientbound packets for connections in the login state.")
+	for k, v := range pIDs.Login.Clientbound {
+		fmt.Printf("  %s%s PktID = %s\n", k, strings.Repeat(" ", maxLen-len(k)), v)
+	}
+	fmt.Println("  // Serverbound packets for connections in the login state.")
+	for k, v := range pIDs.Login.Serverbound {
+		fmt.Printf("  %s%s PktID = %s\n", k, strings.Repeat(" ", maxLen-len(k)), v)
+	}
+	fmt.Println()
+
+	fmt.Println("  // Clientbound packets for connections in the play state.")
+	for k, v := range pIDs.Play.Clientbound {
+		fmt.Printf("  %s%s PktID = %s\n", k, strings.Repeat(" ", maxLen-len(k)), v)
+	}
+	fmt.Println("  // Serverbound packets for connections in the play state.")
+	for k, v := range pIDs.Play.Serverbound {
+		fmt.Printf("  %s%s PktID = %s\n", k, strings.Repeat(" ", maxLen-len(k)), v)
+	}
+	fmt.Println()
+
+	fmt.Println("  // Clientbound packets used to respond to ping/status requests.")
+	for k, v := range pIDs.Status.Clientbound {
+		fmt.Printf("  %s%s PktID = %s\n", k, strings.Repeat(" ", maxLen-len(k)), v)
+	}
+	fmt.Println("  // Serverbound packets used to ping or read server status.")
+	for k, v := range pIDs.Status.Serverbound {
+		fmt.Printf("  %s%s PktID = %s\n", k, strings.Repeat(" ", maxLen-len(k)), v)
+	}
+	fmt.Println()
+
+	fmt.Println(")")
+}

data/inv/inv.go

@@ -0,0 +1,30 @@
+// Package inv maps window types to inventory slot information.
+package inv
+
+type Info struct {
+	Name       string
+	Start, End int // Player inventory
+	Slots      int
+}
+
+func (i Info) PlayerInvStart() int {
+	return i.Start
+}
+
+func (i Info) PlayerInvEnd() int {
+	return i.End
+}
+
+func (i Info) HotbarIdx(place int) int {
+	return i.End - (8 - place)
+}
+
+var ByType = map[int]Info{
+	-1: Info{Name: "inventory", Start: 9, End: 44, Slots: 46},
+	0:  Info{Name: "generic_9x1", Start: 1 * 9, End: 1*9 + 35, Slots: 1*9 + 36},
+	1:  Info{Name: "generic_9x2", Start: 2 * 9, End: 2*9 + 35, Slots: 2*9 + 36},
+	2:  Info{Name: "generic_9x3", Start: 3 * 9, End: 3*9 + 35, Slots: 3*9 + 36},
+	3:  Info{Name: "generic_9x4", Start: 4 * 9, End: 4*9 + 35, Slots: 4*9 + 36},
+	4:  Info{Name: "generic_9x5", Start: 5 * 9, End: 5*9 + 35, Slots: 5*9 + 36},
+	5:  Info{Name: "generic_9x6", Start: 6 * 9, End: 6*9 + 35, Slots: 6*9 + 36},
+}

data/item/gen_item.go

@@ -0,0 +1,168 @@
+// gen_blocks.go generates block information.
+
+//+build ignore
+
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"go/ast"
+	"go/format"
+	"go/token"
+	"net/http"
+	"os"
+	"reflect"
+	"strconv"
+
+	"github.com/iancoleman/strcase"
+)
+
+const (
+	infoURL = "https://raw.githubusercontent.com/PrismarineJS/minecraft-data/master/data/pc/1.16.2/items.json"
+)
+
+type Item struct {
+	ID          uint32 `json:"id"`
+	DisplayName string `json:"displayName"`
+	Name        string `json:"name"`
+	StackSize   uint   `json:"stackSize"`
+}
+
+func downloadInfo() ([]Item, error) {
+	resp, err := http.Get(infoURL)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+
+	var data []Item
+	if err := json.NewDecoder(resp.Body).Decode(&data); err != nil {
+		return nil, err
+	}
+	return data, nil
+}
+
+func makeItemDeclaration(blocks []Item) *ast.DeclStmt {
+	out := &ast.DeclStmt{Decl: &ast.GenDecl{Tok: token.VAR}}
+
+	for _, b := range blocks {
+		t := reflect.TypeOf(b)
+		fields := make([]ast.Expr, t.NumField())
+
+		for i := 0; i < t.NumField(); i++ {
+			ft := t.Field(i)
+
+			var val ast.Expr
+			switch ft.Type.Kind() {
+			case reflect.Uint32, reflect.Int, reflect.Uint:
+				val = &ast.BasicLit{Kind: token.INT, Value: fmt.Sprint(reflect.ValueOf(b).Field(i))}
+			case reflect.Float64:
+				val = &ast.BasicLit{Kind: token.FLOAT, Value: fmt.Sprint(reflect.ValueOf(b).Field(i))}
+			case reflect.String:
+				val = &ast.BasicLit{Kind: token.STRING, Value: strconv.Quote(reflect.ValueOf(b).Field(i).String())}
+			case reflect.Bool:
+				val = &ast.BasicLit{Kind: token.IDENT, Value: fmt.Sprint(reflect.ValueOf(b).Field(i).Bool())}
+
+			case reflect.Slice:
+				val = &ast.CompositeLit{
+					Type: &ast.ArrayType{
+						Elt: &ast.BasicLit{Kind: token.IDENT, Value: ft.Type.Elem().Name()},
+					},
+				}
+				v := reflect.ValueOf(b).Field(i)
+				switch ft.Type.Elem().Kind() {
+				case reflect.Uint32, reflect.Int:
+					for x := 0; x < v.Len(); x++ {
+						val.(*ast.CompositeLit).Elts = append(val.(*ast.CompositeLit).Elts, &ast.BasicLit{
+							Kind:  token.INT,
+							Value: fmt.Sprint(v.Index(x)),
+						})
+					}
+				}
+
+			case reflect.Map:
+				// Must be the NeedsTools map of type map[uint32]bool.
+				m := &ast.CompositeLit{
+					Type: &ast.MapType{
+						Key:   &ast.BasicLit{Kind: token.IDENT, Value: ft.Type.Key().Name()},
+						Value: &ast.BasicLit{Kind: token.IDENT, Value: ft.Type.Elem().Name()},
+					},
+				}
+				iter := reflect.ValueOf(b).Field(i).MapRange()
+				for iter.Next() {
+					m.Elts = append(m.Elts, &ast.KeyValueExpr{
+						Key:   &ast.BasicLit{Kind: token.INT, Value: fmt.Sprint(iter.Key().Uint())},
+						Value: &ast.BasicLit{Kind: token.IDENT, Value: fmt.Sprint(iter.Value().Bool())},
+					})
+				}
+
+				val = m
+			}
+
+			fields[i] = &ast.KeyValueExpr{
+				Key:   &ast.Ident{Name: ft.Name},
+				Value: val,
+			}
+		}
+
+		out.Decl.(*ast.GenDecl).Specs = append(out.Decl.(*ast.GenDecl).Specs, &ast.ValueSpec{
+			Names: []*ast.Ident{{Name: strcase.ToCamel(b.Name)}},
+			Values: []ast.Expr{
+				&ast.CompositeLit{
+					Type: &ast.Ident{Name: reflect.TypeOf(b).Name()},
+					Elts: fields,
+				},
+			},
+		})
+	}
+
+	return out
+}
+
+func main() {
+	items, err := downloadInfo()
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Error: %v\n", err)
+		os.Exit(1)
+	}
+
+	fmt.Println(`// Package item stores information about items in Minecraft.
+package item
+
+import (
+	"math"
+)
+
+// ID describes the numeric ID of an item.
+type ID uint32
+
+// Item describes information about a type of item.
+type Item struct {
+	ID          ID
+	DisplayName string
+	Name        string
+	StackSize   uint
+}
+
+`)
+	format.Node(os.Stdout, token.NewFileSet(), makeItemDeclaration(items))
+
+	fmt.Println()
+	fmt.Println()
+	fmt.Println("// ByID is an index of minecraft items by their ID.")
+	fmt.Println("var ByID = map[ID]*Item{")
+	for _, i := range items {
+		fmt.Printf("  %d: &%s,\n", i.ID, strcase.ToCamel(i.Name))
+	}
+	fmt.Println("}")
+	fmt.Println()
+
+	fmt.Println("// ByName is an index of minecraft items by their name.")
+	fmt.Println("var ByName = map[string]*Item{")
+	for _, i := range items {
+		fmt.Printf("  %q: &%s,\n", i.Name, strcase.ToCamel(i.Name))
+	}
+	fmt.Println("}")
+	fmt.Println()
+}

data/packetIDs.go

@@ -1,156 +1,173 @@
 package data
 
-// Clientbound packet IDs
+//go:generate bash -c "go run gen_packetIDs.go > packetIDs.go"
+
+// This file is automatically generated by gen_packetIDs.go. DO NOT EDIT.
+
+// PktID represents a packet ID used in the minecraft protocol.
+type PktID int32
+
+// Valid PktID values.
 const (
-	SpawnObject int32 = iota //0x00
+  // Clientbound packets for connections in the login state.
-	SpawnExperienceOrb
+  EncryptionBeginClientbound PktID = 0x01
-	SpawnLivingEntity
+  Success                    PktID = 0x02
-	SpawnPainting
+  Compress                   PktID = 0x03
-	SpawnPlayer
+  LoginPluginRequest         PktID = 0x04
-	EntityAnimationClientbound
+  Disconnect                 PktID = 0x00
-	Statistics
+  // Serverbound packets for connections in the login state.
-	AcknowledgePlayerDigging
+  EncryptionBeginServerbound PktID = 0x01
-	BlockBreakAnimation
+  LoginPluginResponse        PktID = 0x02
-	BlockEntityData
+  LoginStart                 PktID = 0x00
-	BlockAction
-	BlockChange
-	BossBar
-	ServerDifficulty
-	ChatMessageClientbound
-	TabComplete
 
-	DeclareCommands //0x10
+  // Clientbound packets for connections in the play state.
-	WindowConfirmationClientbound
+  EntityMetadata             PktID = 0x44
-	CloseWindowClientbound
+  Teams                      PktID = 0x4c
-	WindowItems
+  BossBar                    PktID = 0x0c
-	WindowProperty
+  Map                        PktID = 0x25
-	SetSlot
+  Difficulty                 PktID = 0x0d
-	SetCooldown
+  Camera                     PktID = 0x3e
-	PluginMessageClientbound
+  WindowItems                PktID = 0x13
-	NamedSoundEffect
+  ScoreboardObjective        PktID = 0x4a
-	DisconnectPlay
+  RelEntityMove              PktID = 0x27
-	EntityStatus
+  DeclareCommands            PktID = 0x10
-	Explosion
+  CombatEvent                PktID = 0x31
-	UnloadChunk
+  SpawnEntityPainting        PktID = 0x03
-	ChangeGameState
+  EntityMoveLook             PktID = 0x28
-	OpenHorseWindow
+  ScoreboardScore            PktID = 0x4d
-	KeepAliveClientbound
+  Title                      PktID = 0x4f
+  CraftProgressBar           PktID = 0x14
+  NamedEntitySpawn           PktID = 0x04
+  ScoreboardDisplayObjective PktID = 0x43
+  WorldParticles             PktID = 0x22
+  OpenWindow                 PktID = 0x2d
+  MultiBlockChange           PktID = 0x3b
+  EntitySoundEffect          PktID = 0x50
+  Tags                       PktID = 0x5b
+  EntityUpdateAttributes     PktID = 0x58
+  NamedSoundEffect           PktID = 0x18
+  GameStateChange            PktID = 0x1d
+  PlayerInfo                 PktID = 0x32
+  Advancements               PktID = 0x57
+  Explosion                  PktID = 0x1b
+  KeepAliveClientbound       PktID = 0x1f
+  MapChunk                   PktID = 0x20
+  AttachEntity               PktID = 0x45
+  TradeList                  PktID = 0x26
+  Respawn                    PktID = 0x39
+  EntityDestroy              PktID = 0x36
+  Experience                 PktID = 0x48
+  EntityLook                 PktID = 0x29
+  OpenBook                   PktID = 0x2c
+  WorldEvent                 PktID = 0x21
+  DeclareRecipes             PktID = 0x5a
+  UnlockRecipes              PktID = 0x35
+  EntityEquipment            PktID = 0x47
+  EntityVelocity             PktID = 0x46
+  Animation                  PktID = 0x05
+  UpdateViewDistance         PktID = 0x41
+  HeldItemSlotClientbound    PktID = 0x3f
+  NbtQueryResponse           PktID = 0x54
+  Entity                     PktID = 0x2a
+  UpdateViewPosition         PktID = 0x40
+  AbilitiesClientbound       PktID = 0x30
+  OpenSignEntity             PktID = 0x2e
+  SetSlot                    PktID = 0x15
+  PlayerlistHeader           PktID = 0x53
+  ResourcePackSend           PktID = 0x38
+  SpawnEntityExperienceOrb   PktID = 0x01
+  Collect                    PktID = 0x55
+  Statistics                 PktID = 0x06
+  TileEntityData             PktID = 0x09
+  ChatClientbound            PktID = 0x0e
+  WorldBorder                PktID = 0x3d
+  UnloadChunk                PktID = 0x1c
+  UpdateLight                PktID = 0x23
+  UpdateHealth               PktID = 0x49
+  RemoveEntityEffect         PktID = 0x37
+  KickDisconnect             PktID = 0x19
+  CustomPayloadClientbound   PktID = 0x17
+  SpawnPosition              PktID = 0x42
+  EntityStatus               PktID = 0x1a
+  SpawnEntity                PktID = 0x00
+  SetPassengers              PktID = 0x4b
+  FacePlayer                 PktID = 0x33
+  TransactionClientbound     PktID = 0x11
+  BlockAction                PktID = 0x0a
+  BlockBreakAnimation        PktID = 0x08
+  BlockChange                PktID = 0x0b
+  Login                      PktID = 0x24
+  VehicleMoveClientbound     PktID = 0x2b
+  CraftRecipeResponse        PktID = 0x2f
+  SetCooldown                PktID = 0x16
+  StopSound                  PktID = 0x52
+  EntityEffect               PktID = 0x59
+  CloseWindowClientbound     PktID = 0x12
+  AcknowledgePlayerDigging   PktID = 0x07
+  SelectAdvancementTab       PktID = 0x3c
+  EntityHeadRotation         PktID = 0x3a
+  TabCompleteClientbound     PktID = 0x0f
+  PositionClientbound        PktID = 0x34
+  OpenHorseWindow            PktID = 0x1e
+  UpdateTime                 PktID = 0x4e
+  SpawnEntityLiving          PktID = 0x02
+  EntityTeleport             PktID = 0x56
+  SoundEffect                PktID = 0x51
+  // Serverbound packets for connections in the play state.
+  SetBeaconEffect            PktID = 0x24
+  UpdateStructureBlock       PktID = 0x2a
+  EnchantItem                PktID = 0x08
+  Spectate                   PktID = 0x2d
+  ArmAnimation               PktID = 0x2c
+  QueryEntityNbt             PktID = 0x0d
+  Flying                     PktID = 0x15
+  ResourcePackReceive        PktID = 0x21
+  BlockDig                   PktID = 0x1b
+  AbilitiesServerbound       PktID = 0x1a
+  SelectTrade                PktID = 0x23
+  UpdateJigsawBlock          PktID = 0x29
+  SteerVehicle               PktID = 0x1d
+  Settings                   PktID = 0x05
+  SteerBoat                  PktID = 0x17
+  UseItem                    PktID = 0x2f
+  TeleportConfirm            PktID = 0x00
+  PickItem                   PktID = 0x18
+  CraftRecipeRequest         PktID = 0x19
+  Look                       PktID = 0x14
+  TabCompleteServerbound     PktID = 0x06
+  AdvancementTab             PktID = 0x22
+  ClientCommand              PktID = 0x04
+  EntityAction               PktID = 0x1c
+  PositionServerbound        PktID = 0x12
+  TransactionServerbound     PktID = 0x07
+  UpdateSign                 PktID = 0x2b
+  QueryBlockNbt              PktID = 0x01
+  PositionLook               PktID = 0x13
+  HeldItemSlotServerbound    PktID = 0x25
+  EditBook                   PktID = 0x0c
+  UpdateCommandBlock         PktID = 0x26
+  UseEntity                  PktID = 0x0e
+  GenerateStructure          PktID = 0x0f
+  NameItem                   PktID = 0x20
+  RecipeBook                 PktID = 0x1f
+  KeepAliveServerbound       PktID = 0x10
+  CustomPayloadServerbound   PktID = 0x0b
+  VehicleMoveServerbound     PktID = 0x16
+  CloseWindowServerbound     PktID = 0x0a
+  UpdateCommandBlockMinecart PktID = 0x27
+  WindowClick                PktID = 0x09
+  ChatServerbound            PktID = 0x03
+  SetCreativeSlot            PktID = 0x28
+  DisplayedRecipe            PktID = 0x1e
+  BlockPlace                 PktID = 0x2e
+  LockDifficulty             PktID = 0x11
+  SetDifficulty              PktID = 0x02
 
-	ChunkData //0x20
+  // Clientbound packets used to respond to ping/status requests.
-	Effect
+  ServerInfo                 PktID = 0x00
-	Particle
+  PingClientbound            PktID = 0x01
-	UpdateLight
+  // Serverbound packets used to ping or read server status.
-	JoinGame
+  PingStart                  PktID = 0x00
-	MapData
+  PingServerbound            PktID = 0x01
-	TradeList
-	EntityRelativeMove
-	EntityLookAndRelativeMove
-	EntityLook
-	Entity
-	VehicleMoveClientbound
-	OpenBook
-	OpenWindow
-	OpenSignEditor
-	CraftRecipeResponse
 
-	PlayerAbilitiesClientbound //0x30
-	CombatEvent
-	PlayerInfo
-	FacePlayer
-	PlayerPositionAndLookClientbound
-	UnlockRecipes
-	DestroyEntities
-	RemoveEntityEffect
-	ResourcePackSend
-	Respawn
-	EntityHeadLook
-	MultiBlockChange
-	SelectAdvancementTab
-	WorldBorder
-	Camera
-	HeldItemChangeClientbound
-
-	UpdateViewPosition //0x40
-	UpdateViewDistance
-	SpawnPosition
-	DisplayScoreboard
-	EntityMetadata
-	AttachEntity
-	EntityVelocity
-	EntityEquipment
-	SetExperience
-	UpdateHealth
-	ScoreboardObjective
-	SetPassengers
-	Teams
-	UpdateScore
-	TimeUpdate
-	Title
-
-	EntitySoundEffect //0x50
-	SoundEffect
-	StopSound
-	PlayerListHeaderAndFooter
-	NBTQueryResponse
-	CollectItem
-	EntityTeleport
-	Advancements
-	EntityProperties
-	EntityEffect
-	DeclareRecipes
-	Tags //0x5B
-)
-
-// Serverbound packet IDs
-const (
-	TeleportConfirm int32 = iota //0x00
-	QueryBlockNBT
-	SetDifficulty
-	ChatMessageServerbound
-	ClientStatus
-	ClientSettings
-	TabCompleteServerbound
-	ConfirmTransactionServerbound
-	ClickWindowButton
-	ClickWindow
-	CloseWindowServerbound
-	PluginMessageServerbound
-	EditBook
-	QueryEntityNBT
-	UseEntity
-	GenerateStructure
-
-	KeepAliveServerbound //0x10
-	LockDifficulty
-	PlayerPosition
-	PlayerPositionAndLookServerbound
-	PlayerLook
-	Player
-	VehicleMoveServerbound
-	SteerBoat
-	PickItem
-	CraftRecipeRequest
-	PlayerAbilitiesServerbound
-	PlayerDigging
-	EntityAction
-	SteerVehicle
-	DisplayedRecipe
-	RecipeBookData
-
-	NameItem //0x20
-	ResourcePackStatus
-	AdvancementTab
-	SelectTrade
-	SetBeaconEffect
-	HeldItemChangeServerbound
-	UpdateCommandBlock
-	UpdateCommandBlockMinecart
-	CreativeInventoryAction
-	UpdateJigsawBlock
-	UpdateStructureBlock
-	UpdateSign
-	AnimationServerbound
-	Spectate
-	PlayerBlockPlacement
-	UseItem //0x2F
 )

go.mod

@@ -2,4 +2,8 @@ module github.com/Tnze/go-mc
 
 go 1.13
 
-require github.com/google/uuid v1.1.1
+require (
+	github.com/beefsack/go-astar v0.0.0-20200827232313-4ecf9e304482
+	github.com/google/uuid v1.1.1
+	github.com/iancoleman/strcase v0.1.1 // indirect
+)

go.sum

@@ -1,2 +1,6 @@
+github.com/beefsack/go-astar v0.0.0-20200827232313-4ecf9e304482 h1:p4g4uok3+r6Tg6fxXEQUAcMAX/WdK6WhkQW9s0jaT7k=
+github.com/beefsack/go-astar v0.0.0-20200827232313-4ecf9e304482/go.mod h1:Cu3t5VeqE8kXjUBeNXWQprfuaP5UCIc5ggGjgMx9KFc=
 github.com/google/uuid v1.1.1 h1:Gkbcsh/GbpXz7lPftLA3P6TYMwjCLYm83jiFQZF/3gY=
 github.com/google/uuid v1.1.1/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
+github.com/iancoleman/strcase v0.1.1 h1:2I+LRClyCYB7JgZb9U0k75VHUiQe9RfknRqDyUfzp7k=
+github.com/iancoleman/strcase v0.1.1/go.mod h1:SK73tn/9oHe+/Y0h39VT4UCxmurVJkR5NA7kMEAOgSE=

net/packet/packet.go

@@ -5,6 +5,8 @@ import (
 	"compress/zlib"
 	"fmt"
 	"io"
+
+	"github.com/Tnze/go-mc/data"
 )
 
 // Packet define a net data package
@@ -14,8 +16,8 @@ type Packet struct {
 }
 
 //Marshal generate Packet with the ID and Fields
-func Marshal(ID int32, fields ...FieldEncoder) (pk Packet) {
+func Marshal(id data.PktID, fields ...FieldEncoder) (pk Packet) {
-	pk.ID = ID
+	pk.ID = int32(id)
 
 	for _, v := range fields {
 		pk.Data = append(pk.Data, v.Encode()...)

net/packet/types.go

@@ -2,10 +2,11 @@ package packet
 
 import (
 	"errors"
-	"github.com/google/uuid"
 	"io"
 	"math"
 
+	"github.com/google/uuid"
+
 	"github.com/Tnze/go-mc/nbt"
 )
 
@@ -364,6 +365,16 @@ func (p *Position) Decode(r DecodeReader) error {
 	return nil
 }
 
+//Decodes an Angle
+func (b *Angle) Decode(r DecodeReader) error {
+	v, err := r.ReadByte()
+	if err != nil {
+		return err
+	}
+	*b = Angle(v)
+	return nil
+}
+
 //Encode a Float
 func (f Float) Encode() []byte {
 	return Int(math.Float32bits(float32(f))).Encode()

net/ptypes/chunk.go

@@ -0,0 +1,128 @@
+// Package ptypes implements encoding and decoding for high-level packets.
+package ptypes
+
+import (
+	"bytes"
+	"fmt"
+
+	"github.com/Tnze/go-mc/bot/world/entity"
+	"github.com/Tnze/go-mc/nbt"
+	pk "github.com/Tnze/go-mc/net/packet"
+)
+
+// ChunkData is a clientbound packet which describes a chunk.
+type ChunkData struct {
+	X, Z           pk.Int
+	FullChunk      pk.Boolean
+	PrimaryBitMask pk.VarInt
+	Heightmaps     struct{}
+	Biomes         biomesData
+	Data           chunkData
+	BlockEntities  blockEntities
+}
+
+func (p *ChunkData) Decode(pkt pk.Packet) error {
+	r := bytes.NewReader(pkt.Data)
+	if err := p.X.Decode(r); err != nil {
+		return fmt.Errorf("X: %v", err)
+	}
+	if err := p.Z.Decode(r); err != nil {
+		return fmt.Errorf("Z: %v", err)
+	}
+	if err := p.FullChunk.Decode(r); err != nil {
+		return fmt.Errorf("full chunk: %v", err)
+	}
+	if err := p.PrimaryBitMask.Decode(r); err != nil {
+		return fmt.Errorf("bit mask: %v", err)
+	}
+	if err := (pk.NBT{V: &p.Heightmaps}).Decode(r); err != nil {
+		return fmt.Errorf("heightmaps: %v", err)
+	}
+
+	// Biome data is only present for full chunks.
+	if p.FullChunk {
+		if err := p.Biomes.Decode(r); err != nil {
+			return fmt.Errorf("heightmaps: %v", err)
+		}
+	}
+
+	if err := p.Data.Decode(r); err != nil {
+		return fmt.Errorf("data: %v", err)
+	}
+	if err := p.BlockEntities.Decode(r); err != nil {
+		return fmt.Errorf("block entities: %v", err)
+	}
+	return nil
+}
+
+type biomesData struct {
+	data []pk.VarInt
+}
+
+func (b *biomesData) Decode(r pk.DecodeReader) error {
+	var nobd pk.VarInt // Number of Biome Datums
+	if err := nobd.Decode(r); err != nil {
+		return err
+	}
+	b.data = make([]pk.VarInt, nobd)
+
+	for i := 0; i < int(nobd); i++ {
+		var d pk.VarInt
+		if err := d.Decode(r); err != nil {
+			return err
+		}
+		b.data[i] = d
+	}
+
+	return nil
+}
+
+type chunkData []byte
+type blockEntities []entity.BlockEntity
+
+// Decode implement net.packet.FieldDecoder
+func (c *chunkData) Decode(r pk.DecodeReader) error {
+	var sz pk.VarInt
+	if err := sz.Decode(r); err != nil {
+		return err
+	}
+	*c = make([]byte, sz)
+	if _, err := r.Read(*c); err != nil {
+		return err
+	}
+	return nil
+}
+
+// Decode implement net.packet.FieldDecoder
+func (b *blockEntities) Decode(r pk.DecodeReader) error {
+	var sz pk.VarInt // Number of BlockEntities
+	if err := sz.Decode(r); err != nil {
+		return err
+	}
+	*b = make(blockEntities, sz)
+	decoder := nbt.NewDecoder(r)
+	for i := 0; i < int(sz); i++ {
+		if err := decoder.Decode(&(*b)[i]); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// TileEntityData describes a change to a tile entity.
+type TileEntityData struct {
+	Pos    pk.Position
+	Action pk.UnsignedByte
+	Data   entity.BlockEntity
+}
+
+func (p *TileEntityData) Decode(pkt pk.Packet) error {
+	r := bytes.NewReader(pkt.Data)
+	if err := p.Pos.Decode(r); err != nil {
+		return fmt.Errorf("position: %v", err)
+	}
+	if err := p.Action.Decode(r); err != nil {
+		return fmt.Errorf("action: %v", err)
+	}
+	return nbt.NewDecoder(r).Decode(&p.Data)
+}

net/ptypes/entities.go

@@ -0,0 +1,95 @@
+package ptypes
+
+import pk "github.com/Tnze/go-mc/net/packet"
+
+// SpawnEntity is a clientbound packet used to spawn a non-mob entity.
+type SpawnEntity struct {
+	ID               pk.VarInt
+	UUID             pk.UUID
+	Type             pk.VarInt
+	X, Y, Z          pk.Double
+	Pitch, Yaw       pk.Angle
+	Data             pk.Int
+	VelX, VelY, VelZ pk.Short
+}
+
+func (p *SpawnEntity) Decode(pkt pk.Packet) error {
+	return pkt.Scan(&p.ID, &p.UUID, &p.Type,
+		&p.X, &p.Y, &p.Z, &p.Pitch, &p.Yaw,
+		&p.Data, &p.VelX, &p.VelY, &p.VelZ)
+}
+
+// SpawnPlayer is a clientbound packet used to describe a player entering
+// visible range.
+type SpawnPlayer struct {
+	ID         pk.VarInt
+	UUID       pk.UUID
+	X, Y, Z    pk.Double
+	Yaw, Pitch pk.Angle
+}
+
+func (p *SpawnPlayer) Decode(pkt pk.Packet) error {
+	return pkt.Scan(&p.ID, &p.UUID, &p.X, &p.Y, &p.Z, &p.Yaw, &p.Pitch)
+}
+
+// SpawnLivingEntity is a clientbound packet used to spawn a mob.
+type SpawnLivingEntity struct {
+	ID               pk.VarInt
+	UUID             pk.UUID
+	Type             pk.VarInt
+	X, Y, Z          pk.Double
+	Yaw, Pitch       pk.Angle
+	HeadPitch        pk.Angle
+	VelX, VelY, VelZ pk.Short
+}
+
+func (p *SpawnLivingEntity) Decode(pkt pk.Packet) error {
+	return pkt.Scan(&p.ID, &p.UUID, &p.Type,
+		&p.X, &p.Y, &p.Z, &p.Yaw, &p.Pitch,
+		&p.HeadPitch, &p.VelX, &p.VelY, &p.VelZ)
+}
+
+// EntityAnimationClientbound updates the animationf state of an entity.
+type EntityAnimationClientbound struct {
+	ID        pk.VarInt
+	Animation pk.UnsignedByte
+}
+
+func (p *EntityAnimationClientbound) Decode(pkt pk.Packet) error {
+	return pkt.Scan(&p.ID, &p.Animation)
+}
+
+// EntityPosition is a clientbound packet used to update an entities position.
+type EntityPosition struct {
+	ID       pk.VarInt
+	X, Y, Z  pk.Short // Deltas
+	OnGround pk.Boolean
+}
+
+func (p *EntityPosition) Decode(pkt pk.Packet) error {
+	return pkt.Scan(&p.ID, &p.X, &p.Y, &p.Z, &p.OnGround)
+}
+
+// EntityPosition is a clientbound packet used to update an entities position
+// and its rotation.
+type EntityPositionLook struct {
+	ID         pk.VarInt
+	X, Y, Z    pk.Short // Deltas
+	Yaw, Pitch pk.Angle
+	OnGround   pk.Boolean
+}
+
+func (p *EntityPositionLook) Decode(pkt pk.Packet) error {
+	return pkt.Scan(&p.ID, &p.X, &p.Y, &p.Z, &p.Yaw, &p.Pitch, &p.OnGround)
+}
+
+// EntityRotation is a clientbound packet used to update an entities rotation.
+type EntityRotation struct {
+	ID         pk.VarInt
+	Yaw, Pitch pk.Angle
+	OnGround   pk.Boolean
+}
+
+func (p *EntityRotation) Decode(pkt pk.Packet) error {
+	return pkt.Scan(&p.ID, &p.Yaw, &p.Pitch, &p.OnGround)
+}

net/ptypes/inventory.go

@@ -0,0 +1,89 @@
+// Package ptypes implements encoding and decoding for high-level packets.
+package ptypes
+
+import (
+	"bytes"
+	"errors"
+
+	"github.com/Tnze/go-mc/bot/world/entity"
+	"github.com/Tnze/go-mc/chat"
+	"github.com/Tnze/go-mc/data"
+	"github.com/Tnze/go-mc/nbt"
+	pk "github.com/Tnze/go-mc/net/packet"
+)
+
+// SetSlot is a clientbound packet which configures an inventory slot.
+// A window ID of -1 represents the cursor, and a window ID of 0 represents
+// the players inventory.
+type SetSlot struct {
+	WindowID pk.Byte
+	Slot     pk.Short
+	SlotData entity.Slot
+}
+
+func (p *SetSlot) Decode(pkt pk.Packet) error {
+	if err := pkt.Scan(&p.WindowID, &p.Slot, &p.SlotData); err != nil && !errors.Is(err, nbt.ErrEND) {
+		return err
+	}
+	return nil
+}
+
+// WindowItems is a clientbound packet describing the contents of multiple
+// inventory slots in a window/inventory.
+type WindowItems struct {
+	WindowID pk.Byte
+	Slots    []entity.Slot
+}
+
+func (p *WindowItems) Decode(pkt pk.Packet) error {
+	r := bytes.NewReader(pkt.Data)
+	if err := p.WindowID.Decode(r); err != nil {
+		return err
+	}
+
+	var count pk.Short
+	if err := count.Decode(r); err != nil {
+		return err
+	}
+
+	p.Slots = make([]entity.Slot, int(count))
+	for i := 0; i < int(count); i++ {
+		if err := p.Slots[i].Decode(r); err != nil && !errors.Is(err, nbt.ErrEND) {
+			return err
+		}
+	}
+	return nil
+}
+
+// OpenWindow is a clientbound packet which opens an inventory.
+type OpenWindow struct {
+	WindowID   pk.VarInt
+	WindowType pk.VarInt
+	Title      chat.Message
+}
+
+func (p *OpenWindow) Decode(pkt pk.Packet) error {
+	if err := pkt.Scan(&p.WindowID, &p.WindowType, &p.Title); err != nil && !errors.Is(err, nbt.ErrEND) {
+		return err
+	}
+	return nil
+}
+
+type ConfirmTransaction struct {
+	WindowID pk.Byte
+	ActionID pk.Short
+	Accepted pk.Boolean
+}
+
+func (p *ConfirmTransaction) Decode(pkt pk.Packet) error {
+	return pkt.Scan(&p.WindowID, &p.ActionID, &p.Accepted)
+}
+
+func (p ConfirmTransaction) Encode() pk.Packet {
+	return pk.Marshal(
+		data.TransactionServerbound,
+		p.WindowID,
+		p.ActionID,
+		p.Accepted,
+	)
+}

net/ptypes/misc.go

@@ -0,0 +1,91 @@
+package ptypes
+
+import (
+	"io/ioutil"
+
+	"github.com/Tnze/go-mc/chat"
+	"github.com/Tnze/go-mc/data"
+	pk "github.com/Tnze/go-mc/net/packet"
+)
+
+// SoundEffect is a clientbound packet used to play a specific sound ID
+// on the client.
+type SoundEffect struct {
+	Sound         pk.VarInt
+	Category      pk.VarInt
+	X, Y, Z       pk.Int
+	Volume, Pitch pk.Float
+}
+
+func (p *SoundEffect) Decode(pkt pk.Packet) error {
+	return pkt.Scan(&p.Sound, &p.Category, &p.X, &p.Y, &p.Z, &p.Volume, &p.Pitch)
+}
+
+// NamedSoundEffect is a clientbound packet used to play a sound with the
+// specified name on the client.
+type NamedSoundEffect struct {
+	Sound         pk.String
+	Category      pk.VarInt
+	X, Y, Z       pk.Int
+	Volume, Pitch pk.Float
+}
+
+func (p *NamedSoundEffect) Decode(pkt pk.Packet) error {
+	return pkt.Scan(&p.Sound, &p.Category, &p.X, &p.Y, &p.Z, &p.Volume, &p.Pitch)
+}
+
+// ChatMessageClientbound represents a chat message forwarded by the server.
+type ChatMessageClientbound struct {
+	S      chat.Message
+	Pos    pk.Byte
+	Sender pk.UUID
+}
+
+func (p *ChatMessageClientbound) Decode(pkt pk.Packet) error {
+	return pkt.Scan(&p.S, &p.Pos, &p.Sender)
+}
+
+// UpdateHealth encodes player health/food information from the server.
+type UpdateHealth struct {
+	Health         pk.Float
+	Food           pk.VarInt
+	FoodSaturation pk.Float
+}
+
+func (p *UpdateHealth) Decode(pkt pk.Packet) error {
+	return pkt.Scan(&p.Health, &p.Food, &p.FoodSaturation)
+}
+
+// PluginData encodes the custom data encoded in a plugin message.
+type PluginData []byte
+
+func (p PluginData) Encode() []byte {
+	return []byte(p)
+}
+
+func (p *PluginData) Decode(r pk.DecodeReader) error {
+	data, err := ioutil.ReadAll(r)
+	if err != nil {
+		return err
+	}
+	*p = data
+	return nil
+}
+
+// PluginMessage represents a packet with a customized payload.
+type PluginMessage struct {
+	Channel pk.Identifier
+	Data    PluginData
+}
+
+func (p *PluginMessage) Decode(pkt pk.Packet) error {
+	return pkt.Scan(&p.Channel, &p.Data)
+}
+
+func (p *PluginMessage) Encode() pk.Packet {
+	return pk.Marshal(
+		data.CustomPayloadServerbound,
+		p.Channel,
+		p.Data,
+	)
+}

net/ptypes/motion.go

@@ -0,0 +1,87 @@
+// Package ptypes implements encoding and decoding for high-level packets.
+package ptypes
+
+import (
+	"github.com/Tnze/go-mc/data"
+	pk "github.com/Tnze/go-mc/net/packet"
+)
+
+// PositionAndLookClientbound describes the location and orientation of
+// the player.
+type PositionAndLookClientbound struct {
+	X, Y, Z    pk.Double
+	Yaw, Pitch pk.Float
+	Flags      pk.Byte
+	TeleportID pk.VarInt
+}
+
+func (p *PositionAndLookClientbound) RelativeX() bool {
+	return p.Flags&0x01 != 0
+}
+func (p *PositionAndLookClientbound) RelativeY() bool {
+	return p.Flags&0x02 != 0
+}
+func (p *PositionAndLookClientbound) RelativeZ() bool {
+	return p.Flags&0x04 != 0
+}
+func (p *PositionAndLookClientbound) RelativeYaw() bool {
+	return p.Flags&0x08 != 0
+}
+func (p *PositionAndLookClientbound) RelativePitch() bool {
+	return p.Flags&0x10 != 0
+}
+
+func (p *PositionAndLookClientbound) Decode(pkt pk.Packet) error {
+	return pkt.Scan(&p.X, &p.Y, &p.Z, &p.Yaw, &p.Pitch, &p.Flags, &p.TeleportID)
+}
+
+// PositionAndLookServerbound describes the location and orientation of
+// the player.
+type PositionAndLookServerbound struct {
+	X, Y, Z    pk.Double
+	Yaw, Pitch pk.Float
+	OnGround   pk.Boolean
+}
+
+func (p PositionAndLookServerbound) Encode() pk.Packet {
+	return pk.Marshal(
+		data.PositionLook,
+		pk.Double(p.X),
+		pk.Double(p.Y),
+		pk.Double(p.Z),
+		pk.Float(p.Yaw),
+		pk.Float(p.Pitch),
+		pk.Boolean(p.OnGround),
+	)
+}
+
+// Position describes the position of the player.
+type Position struct {
+	X, Y, Z  pk.Double
+	OnGround pk.Boolean
+}
+
+func (p Position) Encode() pk.Packet {
+	return pk.Marshal(
+		data.PositionServerbound,
+		pk.Double(p.X),
+		pk.Double(p.Y),
+		pk.Double(p.Z),
+		pk.Boolean(p.OnGround),
+	)
+}
+
+// Look describes the rotation of the player.
+type Look struct {
+	Yaw, Pitch pk.Float
+	OnGround   pk.Boolean
+}
+
+func (p Look) Encode() pk.Packet {
+	return pk.Marshal(
+		data.Look,
+		pk.Float(p.Yaw),
+		pk.Float(p.Pitch),
+		pk.Boolean(p.OnGround),
+	)
+}

net/ptypes/world.go

@@ -0,0 +1,32 @@
+package ptypes
+
+import (
+	pk "github.com/Tnze/go-mc/net/packet"
+)
+
+// JoinGame encodes global/world information from the server.
+type JoinGame struct {
+	PlayerEntity pk.Int
+	Hardcore     pk.Boolean
+	Gamemode     pk.UnsignedByte
+	PrevGamemode pk.UnsignedByte
+	WorldCount   pk.VarInt
+	WorldNames   pk.Identifier
+	//DimensionCodec pk.NBT
+	Dimension    pk.Int
+	WorldName    pk.Identifier
+	HashedSeed   pk.Long
+	maxPlayers   pk.VarInt // Now ignored
+	ViewDistance pk.VarInt
+	RDI          pk.Boolean // Reduced Debug Info
+	ERS          pk.Boolean // Enable respawn screen
+	IsDebug      pk.Boolean
+	IsFlat       pk.Boolean
+}
+
+func (p *JoinGame) Decode(pkt pk.Packet) error {
+	return pkt.Scan(&p.PlayerEntity, &p.Hardcore, &p.Gamemode, &p.PrevGamemode,
+		&p.WorldCount, &p.WorldNames, &p.Dimension,
+		&p.WorldName, &p.HashedSeed, &p.maxPlayers, &p.ViewDistance,
+		&p.RDI, &p.ERS, &p.IsDebug, &p.IsFlat)
+}