feat: add Broccoli P00 archive

in alpha stage, filename and image format support may be added later

Legacy/Broccoli/ArcP00.cs

@@ -0,0 +1,96 @@
+//! \file       ArcP00.cs
+//! \date       2026-01-08
+//! \brief      Broccoli resource archive format.
+//
+// Copyright (C) 2026 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.Collections.Generic;
+using System.ComponentModel.Composition;
+using System.IO;
+using System.IO.Compression;
+using GameRes.Utility;
+
+namespace GameRes.Formats.Broccoli {
+    internal class P00Entry : Entry {
+        public string FileName;
+    }
+
+    [Export(typeof(ArchiveFormat))]
+    public class P00Opener : ArchiveFormat {
+        public override string         Tag { get { return "P00"; } }
+        public override string Description { get { return "Broccoli multipart archive format"; } }
+        public override uint     Signature { get { return 0; } }
+        public override bool  IsHierarchic { get { return true; } }
+        public override bool      CanWrite { get { return false; } }
+
+        public P00Opener() {
+            Extensions = new string[] { "p00" };
+        }
+
+        public override ArcFile TryOpen(ArcView file) {
+            var index_file_name = Path.ChangeExtension(file.Name, "pak");
+            if (!VFS.FileExists(index_file_name))
+                return null;
+            using (var index_file = VFS.OpenView(index_file_name)) {
+                if (!index_file.View.AsciiEqual(0, "IPF "))
+                    return null;
+
+                int count = index_file.View.ReadInt32(4);
+                if (!IsSaneCount(count))
+                    return null;
+
+                long index_offset = 8;
+                var dir = new List<Entry>(count);
+                for (int i = 0; i < count; i++) {
+                    uint hash = index_file.View.ReadUInt32(index_offset);
+                    string name = hash.ToString("X8");
+                    var entry = Create<P00Entry>(name);
+                    entry.Offset = index_file.View.ReadUInt32(index_offset + 4);
+                    entry.Size   = index_file.View.ReadUInt32(index_offset + 8);
+                    var data_file_name = Path.ChangeExtension(file.Name, string.Format("p{0:00}", entry.Size >> 28));
+                    if (!VFS.FileExists(data_file_name))
+                        return null;
+                    entry.FileName = data_file_name;
+                    dir.Add(entry);
+                    index_offset += 12;
+                }
+
+                return new ArcFile(file, this, dir);
+            }
+        }
+
+        public override Stream OpenEntry(ArcFile arc, Entry entry) {
+            var pent = entry as P00Entry;
+            using (var data_file = new ArcView(pent.FileName)) {
+                var input = data_file.CreateStream(pent.Offset & 0xFFFFFFF, pent.Size);
+                if (input.ReadUInt16() == 0x305A) { // 'Z0'
+                    input.Seek(10, SeekOrigin.Begin);
+                    return new DeflateStream(input, CompressionMode.Decompress);
+                }
+                else {
+                    input.Seek(0, SeekOrigin.Begin);
+                    return input;
+                }
+            }
+        }
+    }
+}

Legacy/Legacy.csproj

@@ -99,6 +99,7 @@
     <Compile Include="BlackButterfly\ArcDAT.cs" />
     <Compile Include="Blucky\Aliases.cs" />
     <Compile Include="Bom\ImageGRP.cs" />
+    <Compile Include="Broccoli\ArcP00.cs" />
     <Compile Include="CottonClub\ImageLMG.cs" />
     <Compile Include="Desire\ArcDSV.cs" />
     <Compile Include="Desire\ImageDES.cs" />