Add login GUI and location/color persistence

.gitignore

@@ -0,0 +1,4 @@
+*.o
+
+server/players.json
+client/game

client/Makefile

@@ -2,7 +2,7 @@ CXX = g++
 CXXFLAGS = -std=c++20 -Wall -Wextra -O2 -I.
 LDFLAGS = -lraylib -lboost_system -lpthread -lGL -lm -ldl -lrt -lX11
 
-TARGET = game_client
+TARGET = game
 SOURCES = main.cpp PlayerController.cpp net/NetworkManager.cpp
 OBJECTS = $(SOURCES:.cpp=.o)
 

client/main.cpp

@@ -1,10 +1,17 @@
 #include <raylib.h>
 #include <raymath.h>
+
+#define RAYGUI_IMPLEMENTATION
+#include "includes/raygui.h"
+
 #include <iostream>
 #include <vector>
 #include <fstream>
 #include <unordered_map>
 #include <cstdint>
+#include <cstring>
+#include <thread>
+#include <chrono>
 #include "PlayerController.hpp"
 #include "net/NetworkManager.hpp"
 
@@ -93,7 +100,11 @@ struct Heightmap {
 	}
 };
 
-
+enum GameState {
+	STATE_LOGIN,
+	STATE_CONNECTING,
+	STATE_PLAYING
+};
 
 class Game {
 	PlayerController playerController;
@@ -106,6 +117,13 @@ class Game {
 	std::unordered_map<std::string, Texture2D> playerTextures;
 	std::unordered_map<uint32_t, Model> remotePlayerModels;
 
+	// Login UI state
+	GameState gameState = STATE_LOGIN;
+	char usernameBuffer[32] = "";
+	bool editMode = false;
+	std::string loginError = "";
+	std::string currentUsername = "";
+
 public:
 	Game() {
 		InitWindow(1280, 720, "Multiplayer Terrain Game");
@@ -134,12 +152,14 @@ public:
 		// Create player cube (texture will be set when we know our color)
 		auto cubeMesh = GenMeshCube(1.0f, 2.0f, 1.0f);
 		playerModel = LoadModelFromMesh(cubeMesh);
-
-		// Connect to server
-		network.sendLogin();
 	}
 
 	~Game() {
+		// Send logout if we're connected
+		if (gameState == STATE_PLAYING && network.isConnected()) {
+			network.sendLogout();
+		}
+		
 		UnloadTexture(terrainTexture);
 		for (auto& [color, texture] : playerTextures) {
 			UnloadTexture(texture);
@@ -157,14 +177,44 @@ public:
 			update();
 			render();
 		}
+		
+		// Clean logout when window is closing
+		if (gameState == STATE_PLAYING && network.isConnected()) {
+			network.sendLogout();
+			// Give the network time to send the packet
+			std::this_thread::sleep_for(std::chrono::milliseconds(100));
+		}
 	}
 
 private:
 	void update() {
+		switch (gameState) {
+			case STATE_LOGIN:
+				// Login screen - no game updates
+				break;
+
+			case STATE_CONNECTING:
+				// Check if we've received a response from the server
+				if (network.isConnected()) {
+					gameState = STATE_PLAYING;
+					currentUsername = std::string(usernameBuffer);
+				} else if (network.hasLoginError()) {
+					gameState = STATE_LOGIN;
+					loginError = network.getLoginError();
+				}
+				break;
+
+			case STATE_PLAYING:
+				updateGame();
+				break;
+		}
+	}
+
+	void updateGame() {
 		if (!network.isConnected()) {
-			if (IsKeyPressed(KEY_SPACE)) {
+			// Player disconnected, go back to login
-				network.sendLogin();
+			gameState = STATE_LOGIN;
-			}
+			loginError = "Disconnected from server";
 			return;
 		}
 
@@ -244,12 +294,80 @@ private:
 			// Send color change to server
 			network.sendColorChange(NetworkManager::AVAILABLE_COLORS[currentColorIndex]);
 		}
+
+		// Handle logout
+		if (IsKeyPressed(KEY_ESCAPE)) {
+			network.sendLogout();
+			gameState = STATE_LOGIN;
+			loginError = "";
+		}
 	}
 
 	void render() {
 		BeginDrawing();
 		ClearBackground(SKYBLUE);
 
+		switch (gameState) {
+			case STATE_LOGIN:
+				renderLoginScreen();
+				break;
+
+			case STATE_CONNECTING:
+				renderConnectingScreen();
+				break;
+
+			case STATE_PLAYING:
+				renderGame();
+				break;
+		}
+
+		EndDrawing();
+	}
+
+	void renderLoginScreen() {
+		// Center the login box
+		int boxWidth = 300;
+		int boxHeight = 200;
+		int boxX = (GetScreenWidth() - boxWidth) / 2;
+		int boxY = (GetScreenHeight() - boxHeight) / 2;
+
+		// Draw login panel
+		GuiPanel((Rectangle){(float)boxX, (float)boxY, (float)boxWidth, (float)boxHeight}, "Login");
+
+		// Username label and text box
+		GuiLabel((Rectangle){(float)(boxX + 20), (float)(boxY + 50), 80, 30}, "Username:");
+		if (GuiTextBox((Rectangle){(float)(boxX + 100), (float)(boxY + 50), 180, 30},
+		               usernameBuffer, 32, editMode)) {
+			editMode = !editMode;
+		}
+
+		// Login button
+		if (GuiButton((Rectangle){(float)(boxX + 100), (float)(boxY + 100), 100, 30}, "Login")) {
+			if (strlen(usernameBuffer) > 0) {
+				// Send login with username
+				network.sendLoginWithUsername(usernameBuffer);
+				gameState = STATE_CONNECTING;
+				loginError = "";
+			} else {
+				loginError = "Please enter a username";
+			}
+		}
+
+		// Error message
+		if (!loginError.empty()) {
+			DrawText(loginError.c_str(), boxX + 20, boxY + 150, 20, RED);
+		}
+
+		// Instructions
+		DrawText("Enter your username to join the game", 10, 10, 20, WHITE);
+	}
+
+	void renderConnectingScreen() {
+		DrawText("Connecting to server...",
+		         GetScreenWidth()/2 - 100, GetScreenHeight()/2 - 10, 20, WHITE);
+	}
+
+	void renderGame() {
 		BeginMode3D(playerController.getCamera());
 
 		// Draw terrain
@@ -271,16 +389,14 @@ private:
 		EndMode3D();
 
 		// UI
-		DrawText(network.isConnected() ? "Connected" : "Press SPACE to connect", 10, 10, 20, WHITE);
+		DrawText(TextFormat("Logged in as: %s", currentUsername.c_str()), 10, 10, 20, WHITE);
 		DrawText("WASD: Move | Q/E: Strafe | Right-Click: Rotate Camera", 10, 35, 20, WHITE);
-		DrawText("Left/Right Arrow: Change Color | Mouse Wheel: Zoom", 10, 60, 20, WHITE);
+		DrawText("Left/Right Arrow: Change Color | Mouse Wheel: Zoom | ESC: Logout", 10, 60, 20, WHITE);
 		if (network.isConnected()) {
 			std::string colorText = "Your color: " + network.getPlayerColor();
 			DrawText(colorText.c_str(), 10, 85, 20, WHITE);
 		}
 		DrawFPS(10, 110);
-
-		EndDrawing();
 	}
 };
 

client/net/NetworkManager.cpp

@@ -53,6 +53,9 @@ void NetworkManager::processMessage(const uint8_t* data, std::size_t size) {
     case MessageType::ColorChanged:
         handleColorChanged(data, size);
         break;
+    case MessageType::LoginResponse:
+        handleLoginResponse(data, size);
+        break;
     default:
         break;
     }
@@ -179,6 +182,45 @@ void NetworkManager::sendLogin() {
     socket.send_to(buffer(msg), serverEndpoint);
 }
 
+void NetworkManager::sendLoginWithUsername(const std::string& username) {
+    std::cout << "Attempting login with username: " << username << "\n";
+    loginErrorMsg = "";
+    currentUsername = username;
+    std::vector<uint8_t> msg(2 + username.size());
+    msg[0] = static_cast<uint8_t>(MessageType::Login);
+    msg[1] = static_cast<uint8_t>(username.size());
+    std::memcpy(&msg[2], username.data(), username.size());
+    socket.send_to(buffer(msg), serverEndpoint);
+    std::cout << "Login packet sent for username: " << username << "\n";
+}
+
+void NetworkManager::sendLogout() {
+    if (!connected) {
+        std::cout << "Warning: sendLogout called but not connected\n";
+        return;
+    }
+    
+    std::cout << "Sending logout for player ID " << playerID << " (username: " << currentUsername << ")\n";
+    
+    std::array<uint8_t, 5> msg{};
+    msg[0] = static_cast<uint8_t>(MessageType::Logout);
+    uint32_t id = playerID;
+    std::memcpy(&msg[1], &id, sizeof(id));
+    socket.send_to(buffer(msg), serverEndpoint);
+    
+    std::cout << "Logout packet sent, resetting client state\n";
+    
+    // Reset state
+    connected = false;
+    playerID = 0;
+    currentUsername = "";
+    loginErrorMsg = "";  // Clear any error messages
+    {
+        std::lock_guard lock(remotePlayersMutex);
+        remotePlayers.clear();
+    }
+}
+
 void NetworkManager::sendMove(float dx, float dy, float dz) {
     if (!connected) return;
 
@@ -241,3 +283,25 @@ std::unordered_map<uint32_t, RemotePlayer> NetworkManager::getRemotePlayers() {
     std::lock_guard lock(remotePlayersMutex);
     return remotePlayers;
 }
+
+void NetworkManager::handleLoginResponse(const uint8_t* data, std::size_t size) {
+    // Message format: [type(1)][success(1)][messageLen(1)][message(messageLen)]
+    if (size < 3) return;
+    
+    uint8_t success = data[1];
+    uint8_t msgLen = data[2];
+    
+    if (size >= 3 + msgLen) {
+        std::string message(reinterpret_cast<const char*>(&data[3]), msgLen);
+        
+        if (success == 0) {
+            // Login failed
+            loginErrorMsg = message;
+            connected = false;
+            std::cout << "Login failed: " << message << "\n";
+        } else {
+            // Login succeeded, wait for spawn message
+            std::cout << "Login accepted, waiting for spawn...\n";
+        }
+    }
+}

client/net/NetworkManager.hpp

@@ -22,7 +22,9 @@ enum class MessageType : uint8_t {
     PlayerLeft = 0x07,
     PlayerList = 0x08,
     ChangeColor = 0x09,
-    ColorChanged = 0x0A
+    ColorChanged = 0x0A,
+    LoginResponse = 0x0B,
+    Logout = 0x0C
 };
 
 struct RemotePlayer {
@@ -38,11 +40,15 @@ public:
     ~NetworkManager();
 
     void sendLogin();
+    void sendLoginWithUsername(const std::string& username);
+    void sendLogout();
     void sendMove(float dx, float dy, float dz);
     void sendColorChange(const std::string& newColor);
 
     Vector3 getPosition();
     bool isConnected() const { return connected; }
+    bool hasLoginError() const { return !loginErrorMsg.empty(); }
+    std::string getLoginError() const { return loginErrorMsg; }
     uint32_t getPlayerID() const { return playerID; }
     std::string getPlayerColor() const { return playerColor; }
 
@@ -60,6 +66,8 @@ private:
 
     std::atomic<uint32_t> playerID{0};
     std::string playerColor{"red"};
+    std::string currentUsername{""};
+    std::string loginErrorMsg{""};
     std::mutex positionMutex;
     Vector3 serverPosition{0, 0, 0};
     std::atomic<bool> connected{false};
@@ -75,4 +83,5 @@ private:
     void handlePlayerLeft(const uint8_t* data, std::size_t size);
     void handlePlayerList(const uint8_t* data, std::size_t size);
     void handleColorChanged(const uint8_t* data, std::size_t size);
+    void handleLoginResponse(const uint8_t* data, std::size_t size);
 };

server/net/packets.go

@@ -7,16 +7,18 @@ import (
 
 // Message type constants
 const (
-	MSG_LOGIN         = 0x01
+	MSG_LOGIN          = 0x01
-	MSG_POSITION      = 0x02
+	MSG_POSITION       = 0x02
-	MSG_SPAWN         = 0x03
+	MSG_SPAWN          = 0x03
-	MSG_MOVE          = 0x04
+	MSG_MOVE           = 0x04
-	MSG_UPDATE        = 0x05
+	MSG_UPDATE         = 0x05
-	MSG_PLAYER_JOINED = 0x06
+	MSG_PLAYER_JOINED  = 0x06
-	MSG_PLAYER_LEFT   = 0x07
+	MSG_PLAYER_LEFT    = 0x07
-	MSG_PLAYER_LIST   = 0x08
+	MSG_PLAYER_LIST    = 0x08
-	MSG_CHANGE_COLOR  = 0x09
+	MSG_CHANGE_COLOR   = 0x09
-	MSG_COLOR_CHANGED = 0x0A
+	MSG_COLOR_CHANGED  = 0x0A
+	MSG_LOGIN_RESPONSE = 0x0B
+	MSG_LOGOUT         = 0x0C
 )
 
 // Vec3 represents a 3D vector
@@ -142,3 +144,43 @@ func DecodeColorChangePacket(data []byte) (playerID uint32, color string, ok boo
 	color = string(data[6 : 6+colorLen])
 	return playerID, color, true
 }
+
+// EncodeLoginResponsePacket creates a login response packet
+func EncodeLoginResponsePacket(success bool, message string) []byte {
+	msgBytes := []byte(message)
+	msg := make([]byte, 3+len(msgBytes))
+	msg[0] = MSG_LOGIN_RESPONSE
+	if success {
+		msg[1] = 1
+	} else {
+		msg[1] = 0
+	}
+	msg[2] = uint8(len(msgBytes))
+	copy(msg[3:], msgBytes)
+	return msg
+}
+
+// DecodeLoginPacket decodes a login packet with username
+func DecodeLoginPacket(data []byte) (username string, ok bool) {
+	if len(data) < 2 {
+		return "", false
+	}
+	
+	usernameLen := data[1]
+	if len(data) < 2+int(usernameLen) {
+		return "", false
+	}
+	
+	username = string(data[2 : 2+usernameLen])
+	return username, true
+}
+
+// DecodeLogoutPacket decodes a logout packet
+func DecodeLogoutPacket(data []byte) (playerID uint32, ok bool) {
+	if len(data) < 5 {
+		return 0, false
+	}
+	
+	playerID = binary.LittleEndian.Uint32(data[1:5])
+	return playerID, true
+}

server/net/server.go

@@ -16,6 +16,7 @@ import (
 // Player represents a connected player
 type Player struct {
 	ID       uint32
+	Username string
 	Position Vec3
 	Velocity Vec3
 	Color    string
@@ -23,13 +24,22 @@ type Player struct {
 	LastSeen time.Time
 }
 
+// UserData represents persistent user data
+type UserData struct {
+	Username string `json:"username"`
+	Color    string `json:"color"`
+	Position Vec3   `json:"position"`
+}
+
 // Server manages the game state and networking
 type Server struct {
-	conn      *net.UDPConn
+	conn         *net.UDPConn
-	players   map[uint32]*Player
+	players      map[uint32]*Player
-	heightmap [][]float32
+	usersByName  map[string]*Player  // Track by username for preventing duplicates
-	mutex     sync.RWMutex
+	userData     map[string]*UserData // Persistent user data
-	nextID    uint32
+	heightmap    [][]float32
+	mutex        sync.RWMutex
+	nextID       uint32
 }
 
 // NewServer creates a new game server
@@ -45,13 +55,15 @@ func NewServer(port string, heightmap [][]float32) (*Server, error) {
 	}
 
 	server := &Server{
-		conn:      conn,
+		conn:        conn,
-		players:   make(map[uint32]*Player),
+		players:     make(map[uint32]*Player),
-		heightmap: heightmap,
+		usersByName: make(map[string]*Player),
-		nextID:    0,
+		userData:    make(map[string]*UserData),
+		heightmap:   heightmap,
+		nextID:      0,
 	}
 
-	server.loadPlayerPositions()
+	server.loadUserData()
 
 	return server, nil
 }
@@ -65,7 +77,7 @@ func (s *Server) Run() error {
 		ticker := time.NewTicker(10 * time.Second)
 		defer ticker.Stop()
 		for range ticker.C {
-			s.savePlayerPositions()
+			s.saveUserData()
 		}
 	}()
 
@@ -96,34 +108,69 @@ func (s *Server) Run() error {
 
 		switch msgType {
 		case MSG_LOGIN:
-			s.handleLogin(addr)
+			s.handleLogin(buffer[:n], addr)
 		case MSG_MOVE:
 			s.handleMove(buffer[:n], addr)
 		case MSG_CHANGE_COLOR:
 			s.handleColorChange(buffer[:n], addr)
+		case MSG_LOGOUT:
+			s.handleLogout(buffer[:n], addr)
 		}
 	}
 }
 
-func (s *Server) handleLogin(addr *net.UDPAddr) {
+func (s *Server) handleLogin(data []byte, addr *net.UDPAddr) {
+	username, ok := DecodeLoginPacket(data)
+	if !ok || username == "" {
+		// Invalid login packet
+		log.Printf("Received invalid login packet from %s", addr)
+		responseMsg := EncodeLoginResponsePacket(false, "Invalid username")
+		s.conn.WriteToUDP(responseMsg, addr)
+		return
+	}
+	
+	log.Printf("Login attempt for username: %s from %s", username, addr)
+
 	s.mutex.Lock()
+	
+	// Check if username is already logged in
+	if existingPlayer, exists := s.usersByName[username]; exists {
+		s.mutex.Unlock()
+		responseMsg := EncodeLoginResponsePacket(false, "User already logged in")
+		s.conn.WriteToUDP(responseMsg, addr)
+		log.Printf("Login rejected for %s: already logged in (ID: %d)", username, existingPlayer.ID)
+		return
+	}
+
 	s.nextID++
 	playerID := s.nextID
 
-	// Assign color based on player ID
+	// Load saved user data or create new
-	colors := []string{"red", "green", "orange", "purple", "white"}
+	var userData *UserData
-	colorIndex := (playerID - 1) % uint32(len(colors))
+	var exists bool
-	color := colors[colorIndex]
+	if userData, exists = s.userData[username]; !exists {
+		// New user - assign default color and random position
+		colors := []string{"red", "green", "orange", "purple", "white"}
+		colorIndex := (playerID - 1) % uint32(len(colors))
+		color := colors[colorIndex]
 		
-	// Spawn at random position on heightmap
+		x := rand.Float32()*100 - 50
-	x := rand.Float32()*100 - 50
+		z := rand.Float32()*100 - 50
-	z := rand.Float32()*100 - 50
+		y := s.getHeightAt(x, z) + 1.0
-	y := s.getHeightAt(x, z) + 1.0
+		
+		userData = &UserData{
+			Username: username,
+			Color:    color,
+			Position: Vec3{x, y, z},
+		}
+		s.userData[username] = userData
+	}
 
 	player := &Player{
 		ID:       playerID,
-		Position: Vec3{x, y, z},
+		Username: username,
-		Color:    color,
+		Position: userData.Position,
+		Color:    userData.Color,
 		Address:  addr,
 		LastSeen: time.Now(),
 	}
@@ -137,10 +184,15 @@ func (s *Server) handleLogin(addr *net.UDPAddr) {
 	}
 
 	s.players[playerID] = player
+	s.usersByName[username] = player
 	s.mutex.Unlock()
 
-	// Send spawn message with color
+	// Send login success response
-	spawnMsg := EncodeSpawnPacket(playerID, player.Position, color)
+	responseMsg := EncodeLoginResponsePacket(true, "Login successful")
+	s.conn.WriteToUDP(responseMsg, addr)
+
+	// Send spawn message with saved position and color
+	spawnMsg := EncodeSpawnPacket(playerID, userData.Position, userData.Color)
 	s.conn.WriteToUDP(spawnMsg, addr)
 
 	// Send player list to new player
@@ -152,10 +204,10 @@ func (s *Server) handleLogin(addr *net.UDPAddr) {
 	// Notify other players about new player
 	s.broadcastPlayerJoined(player)
 
-	log.Printf("Player %d logged in at (%.2f, %.2f, %.2f) with color %s",
+	log.Printf("Player %s (ID %d) logged in at (%.2f, %.2f, %.2f) with color %s",
-		playerID, x, y, z, color)
+		username, playerID, userData.Position.X, userData.Position.Y, userData.Position.Z, userData.Color)
 
-	s.savePlayerPositions()
+	s.saveUserData()
 }
 
 func (s *Server) handleMove(data []byte, _ *net.UDPAddr) {
@@ -190,12 +242,53 @@ func (s *Server) handleMove(data []byte, _ *net.UDPAddr) {
 	player.Position.Z = newZ
 	player.LastSeen = time.Now()
 	
+	// Update persistent user data
+	if userData, exists := s.userData[player.Username]; exists {
+		userData.Position = player.Position
+	}
+
 	s.mutex.Unlock()
 
 	// Broadcast position update to all players
 	s.broadcastUpdate(player)
 }
 
+func (s *Server) handleLogout(data []byte, _ *net.UDPAddr) {
+	playerID, ok := DecodeLogoutPacket(data)
+	if !ok {
+		log.Printf("Failed to decode logout packet")
+		return
+	}
+	
+	log.Printf("Received logout request for player ID %d", playerID)
+
+	s.mutex.Lock()
+	player, exists := s.players[playerID]
+	if !exists {
+		s.mutex.Unlock()
+		log.Printf("Player ID %d not found in active players", playerID)
+		return
+	}
+
+	// Save final position
+	if userData, exists := s.userData[player.Username]; exists {
+		userData.Position = player.Position
+		userData.Color = player.Color
+	}
+
+	// Remove from active players
+	username := player.Username
+	delete(s.players, playerID)
+	delete(s.usersByName, username)
+	s.mutex.Unlock()
+
+	// Notify other players
+	s.broadcastPlayerLeft(playerID)
+	
+	log.Printf("Player %s (ID %d) successfully logged out", username, playerID)
+	s.saveUserData()
+}
+
 func (s *Server) handleColorChange(data []byte, _ *net.UDPAddr) {
 	playerID, newColor, ok := DecodeColorChangePacket(data)
 	if !ok {
@@ -218,6 +311,12 @@ func (s *Server) handleColorChange(data []byte, _ *net.UDPAddr) {
 	}
 
 	player.Color = newColor
+	
+	// Update persistent user data
+	if userData, exists := s.userData[player.Username]; exists {
+		userData.Color = newColor
+	}
+	
 	s.mutex.Unlock()
 
 	// Broadcast color change to all players
@@ -312,42 +411,58 @@ func (s *Server) checkTimeouts() {
 	now := time.Now()
 	for id, player := range s.players {
 		if now.Sub(player.LastSeen) > 30*time.Second {
+			// Save final position before removing
+			if userData, exists := s.userData[player.Username]; exists {
+				userData.Position = player.Position
+				userData.Color = player.Color
+			}
+			
 			delete(s.players, id)
+			delete(s.usersByName, player.Username)
 			go s.broadcastPlayerLeft(id)
-			log.Printf("Player %d timed out", id)
+			log.Printf("Player %s (ID %d) timed out", player.Username, id)
+			go s.saveUserData()
 		}
 	}
 }
 
-func (s *Server) loadPlayerPositions() {
+func (s *Server) loadUserData() {
 	data, err := os.ReadFile("players.json")
 	if err != nil {
+		log.Printf("No existing user data found: %v", err)
 		return
 	}
 
-	var savedPlayers map[uint32]Vec3
+	var savedUsers map[string]*UserData
-	json.Unmarshal(data, &savedPlayers)
+	if err := json.Unmarshal(data, &savedUsers); err != nil {
-
+		log.Printf("Failed to parse user data: %v", err)
-	for id, pos := range savedPlayers {
+		return
-		if id > s.nextID {
-			s.nextID = id
-		}
-		s.players[id] = &Player{
-			ID:       id,
-			Position: pos,
-			LastSeen: time.Now(),
-		}
 	}
+
+	s.userData = savedUsers
+	log.Printf("Loaded data for %d users", len(savedUsers))
 }
 
-func (s *Server) savePlayerPositions() {
+func (s *Server) saveUserData() {
 	s.mutex.RLock()
-	savedPlayers := make(map[uint32]Vec3)
+	// Deep copy userData to avoid holding lock during file I/O
-	for id, player := range s.players {
+	savedUsers := make(map[string]*UserData)
-		savedPlayers[id] = player.Position
+	for username, data := range s.userData {
+		savedUsers[username] = &UserData{
+			Username: data.Username,
+			Color:    data.Color,
+			Position: data.Position,
+		}
 	}
 	s.mutex.RUnlock()
 
-	data, _ := json.Marshal(savedPlayers)
+	data, err := json.MarshalIndent(savedUsers, "", "  ")
-	os.WriteFile("players.json", data, 0644)
+	if err != nil {
+		log.Printf("Failed to marshal user data: %v", err)
+		return
+	}
+	
+	if err := os.WriteFile("players.json", data, 0644); err != nil {
+		log.Printf("Failed to save user data: %v", err)
+	}
 }

server/players.json

@@ -1 +1,20 @@
-{"1":{"X":-13.046684,"Y":-0.008753866,"Z":15.9760895}}
+{
+  "sky": {
+    "username": "sky",
+    "color": "purple",
+    "position": {
+      "X": 3.9765263,
+      "Y": -5.033655,
+      "Z": 19.824585
+    }
+  },
+  "test": {
+    "username": "test",
+    "color": "red",
+    "position": {
+      "X": 14.141681,
+      "Y": 2.2383373,
+      "Z": -0.06184849
+    }
+  }
+}