add player join messages

include/packets.h

@@ -41,6 +41,7 @@ int sc_updateEntityRotation (int client_fd, int id, uint8_t yaw, uint8_t pitch);
 int sc_damageEvent (int client_fd, int id, int type);
 int sc_setHealth (int client_fd, uint8_t health, uint8_t food);
 int sc_respawn (int client_fd);
+int sc_systemChat (int client_fd, char* message, uint16_t len);
 int sc_registries (int client_fd);
 
 #endif

src/main.c

@@ -81,11 +81,18 @@ void handlePacket (int client_fd, int length, int packet_id) {
         // Send full client spawn sequence
         spawnPlayer(player);
 
+        // Prepare join message for broadcast
+        uint8_t player_name_len = strlen(player->name);
+        char join_message[16 + player_name_len];
+        strcpy(join_message, player->name);
+        strcpy(join_message + player_name_len, " joined the game");
+
         // Register all existing players and spawn their entities, and broadcast
         // information about the joining player to all existing players.
         for (int i = 0; i < MAX_PLAYERS; i ++) {
           if (player_data[i].client_fd == -1) continue;
           sc_playerInfoUpdateAddPlayer(client_fd, player_data[i]);
+          sc_systemChat(player_data[i].client_fd, join_message, 16 + player_name_len);
           if (player_data[i].client_fd == client_fd) continue;
           sc_playerInfoUpdateAddPlayer(player_data[i].client_fd, *player);
           sc_spawnEntityPlayer(client_fd, player_data[i]);

src/packets.c

@@ -901,6 +901,21 @@ int cs_clientStatus (int client_fd) {
   return 0;
 }
 
+int sc_systemChat (int client_fd, char* message, uint16_t len) {
+
+  writeVarInt(client_fd, 5 + len);
+  writeByte(client_fd, 0x72);
+
+  // String NBT tag
+  writeByte(client_fd, 8);
+  writeUint16(client_fd, len);
+  send_all(client_fd, message, len);
+
+  // Is action bar message?
+  writeByte(client_fd, false);
+
+}
+
 // S->C Registry Data (multiple packets) and Update Tags (configuration, multiple packets)
 int sc_registries (int client_fd) {