Boss bar

proto_1.12.2/src/main/java/mc/core/network/proto_1_12_2/State.java

@@ -82,6 +82,7 @@ public enum State {
                     .put(0x1D, AnimationPacket.class)
                     .build(),
             ImmutableMap.<Class<? extends SCPacket>, Integer>builder()
+                    .put(BossBarPacket.class, 0x0C)
                     .put(ChatMessageServerPacket.class, 0x0F)
                     .put(PluginMessagePacket.class, 0x18)
                     .put(KeepAlivePacket.class, 0x1F)

proto_1.12.2/src/main/java/mc/core/network/proto_1_12_2/packets/BossBarPacket.java

@@ -4,5 +4,88 @@
  */
 package mc.core.network.proto_1_12_2.packets;
 
-public class BossBarPacket {
+import lombok.Data;
+import lombok.Setter;
+import lombok.ToString;
+import mc.core.network.NetStream;
+import mc.core.network.SCPacket;
+import mc.core.network.proto_1_12_2.serializers.TextSerializer;
+import mc.core.text.Text;
+
+import java.util.UUID;
+
+@Setter
+@ToString
+public class BossBarPacket implements SCPacket {
+    public static final int ACTION_ADD = 0,
+                            ACTION_REMOVE = 1,
+                            ACTION_UPDATE_HEALTH = 2,
+                            ACTION_UPDATE_TITLE = 3,
+                            ACTION_UPDATE_STYLE = 4,
+                            ACTION_UPDATE_FLAGS = 5;
+
+    public static final int COLOR_PINK = 0,
+                            COLOR_BLUE = 1,
+                            COLOR_RED = 2,
+                            COLOR_GREEN = 3,
+                            COLOR_YELLOW = 4,
+                            COLOR_PURPLE = 5,
+                            COLOR_WHITE = 6;
+
+    public static final int DIVISION_NO = 0,
+                            DIVISION_0 = DIVISION_NO,
+                            DIVISION_6 = 1,
+                            DIVISION_10 = 2,
+                            DIVISION_12 = 3,
+                            DIVISION_20 = 4;
+
+    public static final byte FLAG_NO = 0x00,
+                             FLAG_DAKR_SKY = 0x01,
+                             FLAG_DRAGON_BAR = 0x02;
+
+    @Data
+    public static class BarData {
+        private Text title;
+        /*
+         * From 0 to 1.
+         * Values greater than 1 do not crash a Notchian client,
+         * and start rendering part of a second health bar at around 1.5.
+         * (https://i.johni0702.de/nA.png)
+         */
+        private float health;
+        private int color;
+        private int division;
+        private byte flags;
+    }
+
+    private UUID uuid; // Unique ID for this bar
+    private int action;
+    private BarData barData;
+
+    @Override
+    public void writeSelf(NetStream netStream) {
+        netStream.writeUUID(uuid);
+        netStream.writeVarInt(action);
+
+        if (action == ACTION_REMOVE) {
+            return;
+        }
+
+        if (action == ACTION_ADD || action == ACTION_UPDATE_TITLE) {
+            netStream.writeString(TextSerializer.serialize(barData.title).toString());
+        }
+
+        if (action == ACTION_ADD || action == ACTION_UPDATE_HEALTH) {
+            netStream.writeFloat(barData.health);
+        }
+
+        if (action == ACTION_ADD || action == ACTION_UPDATE_STYLE) {
+            netStream.writeVarInt(barData.color);
+            netStream.writeVarInt(barData.division);
+        }
+
+        if (action == ACTION_ADD || action == ACTION_UPDATE_FLAGS) {
+            netStream.writeUnsignedByte(barData.flags);
+        }
+    }
 }

proto_1.12.2_netty/src/main/java/mc/core/network/proto_1_12_2/netty/handlers/LoginHandler.java

@@ -22,6 +22,7 @@ import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.stereotype.Component;
 
 import java.util.Optional;
+import java.util.UUID;
 
 import static mc.core.network.proto_1_12_2.netty.NettyServer.ATTR_PLAYER;
 import static mc.core.network.proto_1_12_2.netty.NettyServer.ATTR_STATE;
@@ -105,13 +106,26 @@ public class LoginHandler extends AbstractStateHandler implements LoginStateHand
             pkt5.getListPlayers().add(playerData);
             channel.writeAndFlush(pkt5);
 
-            // Send header/footer БЕфиЮ list
+            // Send header/footer <Tab> list
             PlayerListHeaderAndFooterPacket pkt6 = new PlayerListHeaderAndFooterPacket();
             Text text = Text.of(TextColor.GOLD, "=============================");
             pkt6.setHeader(text);
             pkt6.setFooter(text);
             channel.writeAndFlush(pkt6);
 
+            // Send Boss bar
+            BossBarPacket pkt7 = new BossBarPacket();
+            BossBarPacket.BarData barData = new BossBarPacket.BarData();
+            barData.setTitle(Text.of(TextColor.GREEN, TextStyle.BOLD, "FORWOLK"));
+            barData.setColor(BossBarPacket.COLOR_WHITE);
+            barData.setDivision(BossBarPacket.DIVISION_12);
+            barData.setHealth(1.0f);
+            barData.setFlags(BossBarPacket.FLAG_NO);
+            pkt7.setUuid(UUID.randomUUID());
+            pkt7.setAction(BossBarPacket.ACTION_ADD);
+            pkt7.setBarData(barData);
+            channel.writeAndFlush(pkt7);
+
             playerManager.joinServer(player);
         }
     }