feat: add DAT/TIMELEAP format

Incompatible with trial edition, because that the archive in it is not encrypted. The encryption was added in test edition.

ArcFormats/ArcFormats.csproj

@@ -284,6 +284,7 @@
     <Compile Include="FC01\ImageTIL.cs" />
     <Compile Include="FC01\ImageWM2.cs" />
     <Compile Include="FC01\ImageWMK.cs" />
+    <Compile Include="FrontWing\ArcDAT.cs" />
     <Compile Include="FrontWing\ArcFG.cs" />
     <Compile Include="FrontWing\ArcFLT.cs" />
     <Compile Include="FrontWing\ArcVAV.cs" />

ArcFormats/FrontWing/ArcDAT.cs

@@ -0,0 +1,104 @@
+//! \file       ArcDAT.cs
+//! \date       2025-12-13
+//! \brief      FrontWing resource archive.
+//
+// Copyright (C) 2018 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 GameRes.Utility;
+
+namespace GameRes.Formats.FrontWing
+{
+    [Export(typeof(ArchiveFormat))]
+    public class DatOpener : ArchiveFormat
+    {
+        public override string         Tag { get { return "DAT/TIMELEAP"; } }
+        public override string Description { get { return "'Time Leap' resource archive"; } }
+        public override uint     Signature { get { return 0; } }
+        public override bool  IsHierarchic { get { return false; } }
+        public override bool      CanWrite { get { return false; } }
+
+        public override ArcFile TryOpen (ArcView file)
+        {
+            if (file.MaxOffset < 4)
+                return null;
+            int count = file.View.ReadInt32 (file.MaxOffset - 4);
+            if (!IsSaneCount (count))
+                return null;
+
+            int index_size = 0x50 * count;
+            if (file.MaxOffset < index_size + 4)
+                return null;
+            var index = file.View.ReadBytes (file.MaxOffset - 4 - index_size, (uint)index_size);
+            NibbleSwap (index);
+
+            int index_offset = 0;
+            var dir = new List<Entry> (count);
+            for (int i = 0; i < count; i++)
+            {
+                var name = Binary.GetCString (index, index_offset, 0x40);
+                var entry = Create<Entry> (name);
+                entry.Offset = LittleEndian.ToUInt32 (index, index_offset + 0x40);
+                entry.Size   = LittleEndian.ToUInt32 (index, index_offset + 0x48);
+                if (!entry.CheckPlacement (file.MaxOffset))
+                    return null;
+                index_offset += 0x50;
+                dir.Add (entry);
+            }
+            return new ArcFile (file, this, dir);
+        }
+
+        static readonly byte[] keyTable = {
+            0xff, 0xff, 0xff, 0x01,
+            0x9c, 0xaa, 0xa5, 0x00,
+            0x30, 0xff, 0x77, 0x00,
+            0x00, 0x00, 0x00, 0x00,
+            0x00, 0x00, 0x00, 0x00
+        };
+
+        public override Stream OpenEntry (ArcFile arc, Entry entry)
+        {
+            var data = arc.File.View.ReadBytes (entry.Offset, entry.Size);
+            for (int i = 1; i < data.Length; i += 4)
+            {
+                data[i] = (byte)(-data[i] & 0xff);
+            }
+            for (int i = 0; i < data.Length; i += 3)
+            {
+                data[i] ^= keyTable[i / 5 % 5 + i % 6];
+            }
+            NibbleSwap(data, 2, 6);
+            return new BinMemoryStream (data);
+        }
+
+        void NibbleSwap (byte[] buffer, int start = 0, int step = 1)
+        {
+            for (int i = start; i < buffer.Length; i += step)
+            {
+                buffer[i] = (byte)(((buffer[i] & 0xf0) >> 4) + ((buffer[i] & 0xf) << 4));
+            }
+        }
+    }
+}