(Legacy): added formats, mostly PC-98.

Legacy/Neon/ArcAR2.cs

@@ -0,0 +1,90 @@
+//! \file       ArcAR2.cs
+//! \date       2023 Oct 17
+//! \brief      Neon resource archive.
+//
+// Copyright (C) 2023 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;
+
+// [990527][Neon] Onegai! Maid☆Roid
+
+namespace GameRes.Formats.Neon
+{
+    [Export(typeof(ArchiveFormat))]
+    public class Ar2Opener : ArchiveFormat
+    {
+        public override string         Tag => "AR2/NEON";
+        public override string Description => "Neon resource archive";
+        public override uint     Signature => 0;
+        public override bool  IsHierarchic => false;
+        public override bool      CanWrite => false;
+
+        const byte DefaultKey = 0x55;
+
+        public override ArcFile TryOpen (ArcView file)
+        {
+            uint uKey = DefaultKey | DefaultKey << 16;
+            uKey |= uKey << 8;
+            if (file.MaxOffset <= 0x10
+                || file.View.ReadUInt32 (8) != uKey
+                || file.View.ReadUInt32 (0) != file.View.ReadUInt32 (4)
+                || (file.View.ReadUInt32 (0xC) ^ uKey) > 0x100)
+                return null;
+            using (var stream = file.CreateStream())
+            using (var input = new XoredStream (stream, DefaultKey))
+            {
+                var buffer = new byte[0x100];
+                var dir = new List<Entry>();
+                while (0x10 == input.Read (buffer, 0, 0x10))
+                {
+                    uint size = buffer.ToUInt32 (0);
+//                    uint orig_size = buffer.ToUInt32 (4); // original size?
+//                    uint extra = buffer.ToUInt32 (8); // header size/compression?
+                    int name_length = buffer.ToInt32 (0xC);
+                    if (0 == size && 0 == name_length)
+                        continue;
+                    if (name_length <= 0 || name_length > buffer.Length)
+                        return null;
+                    input.Read (buffer, 0, name_length);
+                    var name = Encodings.cp932.GetString (buffer, 0, name_length);
+                    var entry = Create<Entry> (name);
+                    entry.Offset = input.Position;
+                    entry.Size = size;
+                    if (!entry.CheckPlacement (file.MaxOffset))
+                        return null;
+                    dir.Add (entry);
+                    input.Seek (size, SeekOrigin.Current);
+                }
+                return new ArcFile (file, this, dir);
+            }
+        }
+
+        public override Stream OpenEntry (ArcFile arc, Entry entry)
+        {
+            var input = arc.File.CreateStream (entry.Offset, entry.Size);
+            return new XoredStream (input, DefaultKey);
+        }
+    }
+}