fix(party): Converts party packets (#401)

- [X] Converts party packets

Projects/UOContent/Engines/Party/PartyPackets.cs

@@ -0,0 +1,153 @@
+/*************************************************************************
+ * ModernUO                                                              *
+ * Copyright (C) 2019-2021 - ModernUO Development Team                   *
+ * Email: hi@modernuo.com                                                *
+ * File: PartyPackets.cs                                                 *
+ *                                                                       *
+ * This program is free software: you can redistribute it and/or modify  *
+ * it under the terms of the GNU General Public License as published by  *
+ * the Free Software Foundation, either version 3 of the License, or     *
+ * (at your option) any later version.                                   *
+ *                                                                       *
+ * You should have received a copy of the GNU General Public License     *
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>. *
+ *************************************************************************/
+
+using System;
+using System.Buffers;
+using System.Runtime.CompilerServices;
+using Server.Network;
+
+namespace Server.Engines.PartySystem
+{
+    public static class PartyPackets
+    {
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static int GetPartyMemberListPacketLength(Party p) => 7 + p.Count * 4;
+
+        public static void CreatePartyMemberList(Span<byte> buffer, Party p)
+        {
+            if (buffer[0] != 0)
+            {
+                return;
+            }
+
+            var length = GetPartyMemberListPacketLength(p);
+            var writer = new SpanWriter(buffer);
+            writer.Write((byte)0xBF); // Packet ID
+            writer.Write((ushort)length);
+            writer.Write((ushort)0x06); // Sub-packet
+            writer.Write((byte)0x01); // Command
+            writer.Write((byte)p.Count);
+
+            for (var i = 0; i < p.Count; ++i)
+            {
+                writer.Write(p[i].Mobile.Serial);
+            }
+        }
+
+        public static void SendPartyMemberList(this NetState ns, Party p)
+        {
+            if (ns == null)
+            {
+                return;
+            }
+
+            Span<byte> buffer = stackalloc byte[GetPartyMemberListPacketLength(p)];
+            CreatePartyMemberList(buffer, p);
+
+            ns.Send(buffer);
+        }
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static int GetPartyRemoveMemberPacketLength(Party p) => 11 + (p?.Count * 4 ?? 0);
+
+        public static void SendPartyRemoveMember(this NetState ns, Serial m, Party p = null)
+        {
+            if (ns == null)
+            {
+                return;
+            }
+
+            Span<byte> buffer = stackalloc byte[GetPartyRemoveMemberPacketLength(p)];
+            CreatePartyRemoveMember(buffer, m, p);
+
+            ns.Send(buffer);
+        }
+
+        public static void CreatePartyRemoveMember(Span<byte> buffer, Serial removed, Party p = null)
+        {
+            if (buffer[0] != 0)
+            {
+                return;
+            }
+
+            var length = GetPartyRemoveMemberPacketLength(p);
+            var writer = new SpanWriter(buffer);
+            writer.Write((byte)0xBF); // Packet ID
+            writer.Write((ushort)length);
+            writer.Write((ushort)0x06); // Sub-packet
+            writer.Write((byte)0x02);   // Command
+
+            var count = p?.Count ?? 0;
+            writer.Write((byte)count);
+            writer.Write(removed);
+
+            for (var i = 0; i < count; ++i)
+            {
+                writer.Write(p![i].Mobile.Serial);
+            }
+        }
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static int GetPartyTextMessagePacketLength(string text) => 12 + (text?.Length * 2 ?? 0);
+
+        public static void SendPartyTextMessage(this NetState ns, Serial m, string text, bool toAll)
+        {
+            if (ns == null)
+            {
+                return;
+            }
+
+            Span<byte> buffer = stackalloc byte[GetPartyTextMessagePacketLength(text)];
+            CreatePartyTextMessage(buffer, m, text, toAll);
+
+            ns.Send(buffer);
+        }
+
+        public static void CreatePartyTextMessage(Span<byte> buffer, Serial m, string text, bool toAll)
+        {
+            if (buffer[0] != 0)
+            {
+                return;
+            }
+
+            var length = GetPartyTextMessagePacketLength(text);
+            var writer = new SpanWriter(buffer);
+            writer.Write((byte)0xBF); // Packet ID
+            writer.Write((ushort)length);
+            writer.Write((ushort)0x06); // Sub-packet
+            writer.Write((byte)(toAll ? 0x04 : 0x03));
+            writer.Write(m);
+            writer.WriteBigUniNull(text);
+        }
+
+        public static void SendPartyInvitation(this NetState ns, Serial leader)
+        {
+            if (ns == null)
+            {
+                return;
+            }
+
+            Span<byte> buffer = stackalloc byte[10];
+            var writer = new SpanWriter(buffer);
+            writer.Write((byte)0xBF); // Packet ID
+            writer.Write((ushort)10);
+            writer.Write((ushort)0x06); // Sub-packet
+            writer.Write((byte)0x07); // command
+            writer.Write(leader);
+
+            ns.Send(buffer);
+        }
+    }
+}