From 8a6afe6551f53fe0c7f83eaa5c1cb5ebf45aee0a Mon Sep 17 00:00:00 2001
From: diandianxz <granbluedjeeta@outlook.com>
Date: Mon, 25 May 2026 15:58:26 +0800
Subject: [PATCH 1/3] Update ArcLINK.cs

Add a decompression method that decides whether to use BMR or LZSS based on the value of flag & 3
---
 ArcFormats/Kaguya/ArcLINK.cs | 56 ++++++++++++++++++++++++++----------
 1 file changed, 41 insertions(+), 15 deletions(-)

diff --git a/ArcFormats/Kaguya/ArcLINK.cs b/ArcFormats/Kaguya/ArcLINK.cs
index 9ce87efb9..2f3a6459d 100644
--- a/ArcFormats/Kaguya/ArcLINK.cs
+++ b/ArcFormats/Kaguya/ArcLINK.cs
@@ -1,4 +1,4 @@
-//! \file       ArcLINK.cs
+//! \file       ArcLINK.cs
 //! \date       Fri Jan 22 18:44:56 2016
 //! \brief      KaGuYa archive format.
 //
@@ -34,6 +34,7 @@ namespace GameRes.Formats.Kaguya
     internal class LinkEntry : PackedEntry
     {
         public bool IsEncrypted;
+		public int  PackType;
     }
 
     internal class LinkArchive : ArcFile
@@ -110,13 +111,28 @@ public override Stream OpenEntry (ArcFile arc, Entry entry)
                     return base.OpenEntry (arc, entry);
                 return larc.Encryption.DecryptEntry (larc, lent);
             }
-            using (var input = arc.File.CreateStream (entry.Offset, entry.Size))
-            using (var bmr = new BmrDecoder (input))
-            {
-                bmr.Unpack();
-                return new BinMemoryStream (bmr.Data, entry.Name);
-            }
-        }
+			using (var input = arc.File.CreateStream (entry.Offset, entry.Size))
+			{
+				if (lent.PackType == 2)
+				{
+					using (var bmr = new BmrDecoder (input))
+					{
+						bmr.Unpack();
+						return new BinMemoryStream (bmr.Data, entry.Name);
+					}
+				}
+				else if (lent.PackType == 1)	//LZSS
+				{
+					using (var lz_input = arc.File.CreateStream(entry.Offset + 4, entry.Size - 4, entry.Name))
+					using (var lz = new LzReader(lz_input.AsStream, entry.Size - 4, lent.UnpackedSize))
+					{
+						lz.Unpack();
+						return new BinMemoryStream (lz.Data, entry.Name);
+					}
+				}
+			}
+			return base.OpenEntry (arc, entry);
+		}
 
         internal ArcFile ReadOldIndex (ArcView file)
         {
@@ -211,13 +227,22 @@ public List<Entry> ReadIndex ()
                 entry.Size   = size - (uint)(entry.Offset - base_offset);
                 if (is_compressed)
                 {
-                    m_input.Read (header, 0, 4);
-                    if (header.AsciiEqual ("BMR"))
-                    {
-                        entry.IsPacked = true;
-                        entry.UnpackedSize = m_input.ReadUInt32();
-                    }
-                }
+					entry.PackType = flags & 3;
+					if (entry.PackType == 2)  // BMR
+					{
+						m_input.Read (header, 0, 4);
+						if (header.AsciiEqual ("BMR"))
+						{
+							entry.IsPacked = true;
+							entry.UnpackedSize = m_input.ReadUInt32();
+						}
+					}
+					else if (entry.PackType == 1)  // LZSS
+					{
+						entry.IsPacked = true;
+						entry.UnpackedSize = m_input.ReadUInt32();
+					}
+				}
                 entry.IsEncrypted = (flags & 4) != 0;
                 m_has_encrypted = m_has_encrypted || entry.IsEncrypted;
                 dir.Add (entry);
@@ -466,6 +491,7 @@ public void Dispose ()
         #endregion
     }
 
+
     internal abstract class ParamsDeserializer
     {
         protected IBinaryStream     m_input;

From a7fd090082488bd913d75cf43e8cd16f7d1b9405 Mon Sep 17 00:00:00 2001
From: diandianxz <granbluedjeeta@outlook.com>
Date: Mon, 25 May 2026 22:55:04 +0800
Subject: [PATCH 2/3] test


From 0b94b9db4a87160efad52eb97cde07225bf6451b Mon Sep 17 00:00:00 2001
From: diandianxz <granbluedjeeta@outlook.com>
Date: Mon, 25 May 2026 23:00:48 +0800
Subject: [PATCH 3/3] Update ArcLINK.cs

Add LZSS decompression support for PackType=1

Original code hardcoded only BMR (PackType=2), ignoring the control flag.
Now both PackType=1 (LZSS) and PackType=2 (BMR) are supported.

Tested locally with existing BMR files (no regression) and new LZSS files.