Added player identification

server/game/Account.go

@@ -0,0 +1,9 @@
+package game
+
+// Account represents a player account
+type Account struct {
+	ID       string  `json:"id"`
+	Name     string  `json:"name"`
+	Password string  `json:"password"`
+	Position Vector3 `json:"position"`
+}

server/game/Database.go

@@ -0,0 +1,33 @@
+package game
+
+var accounts = map[string]*Account{
+	"user0": {
+		ID:       "4J6qpK1ve",
+		Name:     "user0",
+		Password: "password",
+		Position: Vector3{5, 0, 0},
+	},
+	"user1": {
+		ID:       "I_vyeZamg",
+		Name:     "user1",
+		Password: "password",
+		Position: Vector3{-5, 0, 0},
+	},
+	"user2": {
+		ID:       "VJOK1ckvx",
+		Name:     "user2",
+		Password: "password",
+		Position: Vector3{0, 0, 5},
+	},
+	"user3": {
+		ID:       "EkCcqbwFl",
+		Name:     "user3",
+		Password: "password",
+		Position: Vector3{0, 0, -5},
+	},
+}
+
+// GetAccountByName retrieves the account with the given name.
+func GetAccountByName(name string) *Account {
+	return accounts[name]
+}

server/game/Login.go

@@ -3,61 +3,75 @@ package game
 import (
 	"crypto/rand"
 	"encoding/base64"
+	"encoding/binary"
 	"encoding/json"
 	"errors"
 	"net"
 	"server/game/packet"
 )
 
-var (
-	LoginSuccess = []byte{0}
-	LoginFailure = []byte{1}
+const (
+	Success = 0
+	Failure = 1
 )
 
 // Login checks the account credentials and gives a network peer access to an account.
 func (game *Game) Login(data []byte, address *net.UDPAddr, server *Server) error {
+	if game.players.Get(address) != nil {
+		server.Send(packet.Login, []byte{Failure}, address)
+		return errors.New("already logged in")
+	}
+
 	username, password, err := getLoginData(data)
 
 	if err != nil {
-		server.Send(packet.Login, LoginFailure, address)
+		server.Send(packet.Login, []byte{Failure}, address)
 		return err
 	}
 
+	account := GetAccountByName(username)
+
+	if account == nil {
+		server.Send(packet.Login, []byte{Failure}, address)
+		return errors.New("unknown account name")
+	}
+
 	if password != "password" {
-		server.Send(packet.Login, LoginFailure, address)
+		server.Send(packet.Login, []byte{Failure}, address)
 		return errors.New("login failure")
 	}
 
-	player := game.players.Get(address)
-	player.AuthToken = createAuthToken()
-	player.Name = username
+	player := game.players.Add(address, account)
+	player.authToken = createAuthToken()
 	player.KeepAlive()
 
-	if username == "user0" {
-		player.Position.X = 5.0
-	}
+	response := []byte{Success}
+	response = appendString(response, account.ID)
+	response = appendString(response, player.authToken)
+	server.Send(packet.Login, response, address)
 
-	if username == "user1" {
-		player.Position.X = -5.0
-	}
+	game.onLogin(player)
+	return nil
+}
 
-	if username == "user2" {
-		player.Position.Z = -5.0
-	}
-
-	if username == "user3" {
-		player.Position.Z = 5.0
-	}
-
-	server.Send(packet.Login, append(LoginSuccess, []byte(player.AuthToken)...), address)
-	player.OnConnect()
+func appendString(data []byte, str string) []byte {
+	data = binary.LittleEndian.AppendUint32(data, uint32(len(str)))
+	data = append(data, []byte(str)...)
+	return data
+}
 
+// Inform the newly logged in player about existing players.
+// Also inform existing players about the newly logged in player.
+func (game *Game) onLogin(player *Player) {
 	game.players.Each(func(other *Player) bool {
-		server.Send(packet.PlayerState, other.State(), address)
+		game.server.Send(packet.PlayerAdd, other.State(), player.address)
+
+		if other != player {
+			game.server.Send(packet.PlayerAdd, player.State(), other.address)
+		}
+
 		return true
 	})
-
-	return nil
 }
 
 func getLoginData(data []byte) (string, string, error) {

server/game/Player.go

@@ -8,16 +8,16 @@ import (
 
 // Player represents a logged in client.
 type Player struct {
-	Name       string  `json:"name"`
-	Position   Vector3 `json:"position"`
-	AuthToken  string
+	*Account
+	authToken  string
 	address    *net.UDPAddr
 	lastPacket time.Time
 }
 
-// NewClient creates a new client.
-func NewClient(address *net.UDPAddr) *Player {
+// NewPlayer creates a new player.
+func NewPlayer(account *Account, address *net.UDPAddr) *Player {
 	return &Player{
+		Account: account,
 		address: address,
 	}
 }
@@ -37,9 +37,11 @@ func (c *Player) Tick() {
 	// ...
 }
 
-// State returns the player state (name and position).
+// State returns the player state (ID, name and position).
 func (player *Player) State() []byte {
-	state := []byte(player.Name + "\u0000")
+	state := []byte{}
+	state = appendString(state, player.ID)
+	state = appendString(state, player.Name)
 	state = appendVector3(state, player.Position)
 	return state
 }

server/game/PlayerManager.go

@@ -43,9 +43,18 @@ func NewPlayerManager() *PlayerManager {
 	return m
 }
 
+// Add adds a new player with the given address and account.
+func (m *PlayerManager) Add(address *net.UDPAddr, account *Account) *Player {
+	player := NewPlayer(account, address)
+	m.players.Store(address.String(), player)
+	m.count.Add(1)
+	player.OnConnect()
+	return player
+}
+
 // Contains tells you whether the address is already a registered client.
-func (m *PlayerManager) Contains(addr *net.UDPAddr) bool {
-	_, exists := m.players.Load(addr.String())
+func (m *PlayerManager) Contains(address *net.UDPAddr) bool {
+	_, exists := m.players.Load(address.String())
 	return exists
 }
 
@@ -62,15 +71,12 @@ func (m *PlayerManager) Each(callback func(*Player) bool) {
 }
 
 // Get either returns a new or existing client for the requested address.
-func (m *PlayerManager) Get(addr *net.UDPAddr) *Player {
-	obj, exists := m.players.Load(addr.String())
+func (m *PlayerManager) Get(address *net.UDPAddr) *Player {
+	obj, exists := m.players.Load(address.String())
 
-	if exists {
-		return obj.(*Player)
+	if !exists {
+		return nil
 	}
 
-	client := NewClient(addr)
-	m.players.Store(addr.String(), client)
-	m.count.Add(1)
-	return client
+	return obj.(*Player)
 }

server/game/packet/packet.go

@@ -1,8 +1,10 @@
 package packet
 
 const (
-	Ping        = 1
-	Login       = 2
-	Logout      = 3
-	PlayerState = 10
+	Ping         = 1
+	Login        = 2
+	Logout       = 3
+	PlayerAdd    = 10
+	PlayerRemove = 11
+	PlayerMove   = 12
 )