(Legacy): bunch of formats.

(GSX): K5 archives + K4 images.
(HyperWorks): G images.
(IDA): better support packed entries.
(Logg): ARF, MBM archives, FRM images.
(Omi): DAT archives.
(Rare): X archives.
(RHSS): 'CRG' archives.
(SplushWave): better SWG images support.

Legacy/Rare/ArcX.cs

@@ -0,0 +1,132 @@
+//! \file       ArcX.cs
+//! \date       2023 Sep 02
+//! \brief      Rare archive format.
+//
+// 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;
+
+// [990528][Rare] Seisen Ren'ai Yuugi
+
+namespace GameRes.Formats.Rare
+{
+    [Export(typeof(ArchiveFormat))]
+    public class XOpener : ArchiveFormat
+    {
+        public override string         Tag => "X/RARE";
+        public override string Description => "Rare resource archive";
+        public override uint     Signature => 0;
+        public override bool  IsHierarchic => false;
+        public override bool      CanWrite => false;
+
+        static readonly Dictionary<string, Tuple<uint, int>> KnownExeMap = new Dictionary<string, Tuple<uint, int>> {
+            { "seisen.exe", Tuple.Create (0x3A9A0u, 715) },
+        };
+
+        public override ArcFile TryOpen (ArcView file)
+        {
+            if (!VFS.IsPathEqualsToFileName (file.Name, "PP.X"))
+                return null;
+            string full_exe_name = null;
+            Tuple<uint, int> index_pos = null;
+            foreach (var exe_name in KnownExeMap.Keys)
+            {
+                full_exe_name = VFS.ChangeFileName (file.Name, exe_name);
+                if (VFS.FileExists (full_exe_name))
+                {
+                    index_pos = KnownExeMap[exe_name];
+                    break;
+                }
+            }
+            if (null == index_pos)
+                return null;
+            uint index_offset = index_pos.Item1;
+            int count = index_pos.Item2;
+            using (var index = VFS.OpenView (full_exe_name))
+            {
+                index.View.Reserve (index_offset, (uint)count * 12u);
+                var dir = new List<Entry> (count);
+                for (int i = 0; i < count; ++i)
+                {
+                    var entry = new PackedEntry {
+                        Name = string.Format ("PP#{0:D5}.BMP", i),
+                        Type = "image",
+                        Offset = index.View.ReadUInt32 (index_offset),
+                        Size   = index.View.ReadUInt32 (index_offset+4),
+                        UnpackedSize = index.View.ReadUInt32 (index_offset+8),
+                        IsPacked = true,
+                    };
+                    if (!entry.CheckPlacement (file.MaxOffset))
+                        return null;
+                    dir.Add (entry);
+                    index_offset += 12;
+                }
+                return new ArcFile (file, this, dir);
+            }
+        }
+
+        public override Stream OpenEntry (ArcFile arc, Entry entry)
+        {
+            var pent = (PackedEntry)entry;
+            using (var input = arc.File.CreateStream (entry.Offset, entry.Size))
+            {
+                var output = new byte[pent.UnpackedSize];
+                Decompress (input, output);
+                return new BinMemoryStream (output, entry.Name);
+            }
+        }
+
+        internal static void Decompress (IBinaryStream input, byte[] output)
+        {
+            var frame = new byte[0x400];
+            int frame_pos = 1;
+            int dst = 0;
+            using (var bits = new MsbBitStream (input.AsStream, true))
+            {
+                while (dst < output.Length)
+                {
+                    int ctl = bits.GetNextBit();
+                    if (-1 == ctl)
+                        break;
+                    if (ctl != 0)
+                    {
+                        int v = bits.GetBits (8);
+                        output[dst++] = frame[frame_pos++ & 0x3FF] = (byte)v;
+                    }
+                    else
+                    {
+                        int offset = bits.GetBits (10);
+                        int count = bits.GetBits (5) + 2;
+                        while (count --> 0)
+                        {
+                            byte v = frame[offset++ & 0x3FF];
+                            output[dst++] = frame[frame_pos++ & 0x3FF] = v;
+                        }
+                    }
+                }
+            }
+        }
+    }
+}