From a0b9084978a15f42e6dd8dba461225ebaf1df4ba Mon Sep 17 00:00:00 2001
From: Crsky <crskycode@hotmail.com>
Date: Tue, 10 Feb 2026 08:03:59 +0800
Subject: [PATCH] feat: Add Frontier Works engine resource archive support

---
 ArcFormats/ArcFormats.csproj         |   1 +
 ArcFormats/FrontierWorks/ArcPCARC.cs | 117 +++++++++++++++++++++++++++
 2 files changed, 118 insertions(+)
 create mode 100644 ArcFormats/FrontierWorks/ArcPCARC.cs

diff --git a/ArcFormats/ArcFormats.csproj b/ArcFormats/ArcFormats.csproj
index 757307ed..2cd422b4 100644
--- a/ArcFormats/ArcFormats.csproj
+++ b/ArcFormats/ArcFormats.csproj
@@ -141,6 +141,7 @@
     <Compile Include="AIRNovel\ArcAIR.cs" />
     <Compile Include="aNCHOR\ArcFPD.cs" />
     <Compile Include="aNCHOR\AudioFCD.cs" />
+    <Compile Include="FrontierWorks\ArcPCARC.cs" />
     <Compile Include="Artemis\ImageNekoPNG.cs" />
     <Compile Include="CsWare\AudioWAV.cs" />
     <Compile Include="CsWare\ImageGDT.cs" />
diff --git a/ArcFormats/FrontierWorks/ArcPCARC.cs b/ArcFormats/FrontierWorks/ArcPCARC.cs
new file mode 100644
index 00000000..56f0d855
--- /dev/null
+++ b/ArcFormats/FrontierWorks/ArcPCARC.cs
@@ -0,0 +1,117 @@
+//! \file       ArcPCARC.cs
+//! \date       Tue Feb 10 2026 07:56:13
+//! \brief      Frontier Works engine resource archive.
+//
+// Copyright (C) 2015 by morkt
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to
+// deal in the Software without restriction, including without limitation the
+// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+// sell copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+// IN THE SOFTWARE.
+//
+
+using System;
+using System.Collections.Generic;
+using System.ComponentModel.Composition;
+using System.IO;
+using System.IO.Compression;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace GameRes.Formats.FrontierWorks
+{
+    [Export(typeof(ArchiveFormat))]
+    public class PcArcOpener : ArchiveFormat
+    {
+        public override string         Tag { get { return "PCARC"; } }
+        public override string Description { get { return "Frontier Works engine resource archive"; } }
+        public override uint     Signature { get { return 0x30303130; } } // "0100"
+        public override bool  IsHierarchic { get { return true; } }
+        public override bool      CanWrite { get { return false; } }
+
+        public PcArcOpener()
+        {
+            Extensions = new string[] { "pcarc" };
+        }
+
+        public override ArcFile TryOpen (ArcView file)
+        {
+            if (!file.View.AsciiEqual (0, "0100"))
+                return null;
+            var dir_count = file.View.ReadInt32 (4);
+            if (dir_count <= 0 || dir_count > 32)
+                return null;
+            var data_offset = file.View.ReadInt64 (8);
+            if (data_offset < 0x190)
+                return null;
+            var offset = 0x10;
+            var dir = new List<Entry> ();
+            for (var i = 0; i < dir_count; i++)
+            {
+                var dir_offset = file.View.ReadInt64 (offset);
+                offset += 8;
+                if (dir_offset < 0x190)
+                    break;
+                var path = file.View.ReadString (dir_offset, 0x40);
+                var entry_count = file.View.ReadInt32 (dir_offset+0x40);
+                dir_offset += 0x50;
+                if (!string.IsNullOrEmpty (path) && !path.EndsWith ("/"))
+                    path += "/";
+                for (var j = 0; j < entry_count; j++)
+                {
+                    var entry = new Entry ();
+                    entry.Name = path+file.View.ReadString (dir_offset, 0x40);
+                    entry.Offset = data_offset+file.View.ReadInt64 (dir_offset+0x40);
+                    entry.Size = file.View.ReadUInt32 (dir_offset+0x48);
+                    dir.Add (entry);
+                    dir_offset += 0x50;
+                }
+            }
+            DetectFileTypes (dir);
+            return new ArcFile (file, this, dir);
+        }
+
+        public override Stream OpenEntry (ArcFile arc, Entry entry)
+        {
+            if (entry.Name.HasExtension (".gz"))
+            {
+                using (var input = arc.File.CreateStream (entry.Offset, entry.Size))
+                using (var gzs = new GZipStream (input, CompressionMode.Decompress))
+                {
+                    var output = new MemoryStream ();
+                    gzs.CopyTo (output);
+                    return new BinMemoryStream (output, entry.Name.Substring (0, entry.Name.Length-3));
+                }
+            }
+            return base.OpenEntry (arc, entry);
+        }
+
+        static void DetectFileTypes (List<Entry> dir)
+        {
+            foreach (var entry in dir)
+            {
+                var name = entry.Name;
+                if (name.HasExtension (".gz"))
+                    name = name.Substring (0, name.Length-3);
+                if (name.HasExtension (".oggl"))
+                    entry.Type = "audio";
+                if (string.IsNullOrEmpty (entry.Type))
+                    entry.Type = FormatCatalog.Instance.GetTypeFromName (name);
+            }
+        }
+    }
+}