[Entergram] 封包支持

2026-07-08 01:30:18 +08:00 · 2026-05-22 00:27:09 +08:00
parent 02e9dc6c5c
commit 446b9dff3e
4 changed files with 331 additions and 0 deletions
--- a/ArcFormats/Entergram/ArcPacV1.cs
+++ b/ArcFormats/Entergram/ArcPacV1.cs
@@ -0,0 +1,153 @@
+using System;
+using System.Collections.Generic;
+using System.ComponentModel.Composition;
+using System.IO;
+using System.Linq;
+using System.Text;
+
+namespace GameRes.Formats.Entergram
+{
+    [Export(typeof(ArchiveFormat))]
+    public class PacOpenerV1 : ArchiveFormat
+    {
+        public override string Tag => "PacV1/Entergram";
+        public override string Description => "Entergram Unity resource archive";
+        public override uint Signature => 0x20434150;  // PAC/x20
+        public override bool IsHierarchic => true;
+        public override bool CanWrite => false;
+
+        private static readonly byte[] smHeader = new byte[]
+        {
+            0x50, 0x41, 0x43, 0x20, 0x56, 0x45, 0x52, 0x2D, 0x31, 0x2E, 0x30, 0x30, 0x00, 0x00, 0x00, 0x00
+        };
+
+        public override ArcFile TryOpen(ArcView file)
+        {
+            if (!file.View.BytesEqual(0L, smHeader))
+            {
+                return null;
+            }
+
+            List<Entry> entries = this.ParseEntry(file);
+            if(entries == null)
+            {
+                return null;
+            }
+
+            return new ArcFile(file, this, entries);
+        }
+
+        public override Stream OpenEntry(ArcFile arc, Entry entry)
+        {
+            if(!(entry is PackedEntry e))
+            {
+                return base.OpenEntry(arc, entry);
+            }
+
+            if (e.IsPacked)
+            {
+                using(ArcViewStream s = arc.File.CreateStream(e.Offset, e.Size))
+                {
+                    byte[] data = s.ReadBytes(int.MaxValue);
+                    data = QLZCompressor.Decompress(data);
+                    return new MemoryStream(data, false);
+                }
+            }
+            else
+            {
+                return base.OpenEntry(arc, entry);
+            }
+        }
+
+        private List<Entry> ParseEntry(ArcView file)
+        {
+            bool compressed = Path.GetFileNameWithoutExtension(file.Name).EndsWith("_c");
+            using(ArcViewStream stream = file.CreateStream(smHeader.LongLength))
+            {
+                List<PackedEntry> entries = new List<PackedEntry>();
+
+                // 8 Bytes Entry Mode (Default)
+                {
+                    stream.Position = 0L;
+                    while (stream.Position < stream.Length)
+                    {
+                        string name = ReadString(stream);
+
+                        long offset = stream.ReadInt64() + 0x10L;
+                        long length = stream.ReadInt64();
+                        if (!CheckEntry(offset, length, file.MaxOffset))
+                        {
+                            entries.Clear();
+                            break;
+                        }
+
+                        PackedEntry entry = Create<PackedEntry>(name);
+                        entry.Offset = offset;
+                        entry.Size = (uint)length;
+                        entry.IsPacked = compressed;
+                        entries.Add(entry);
+
+                        stream.Seek(length, SeekOrigin.Current);
+                    }
+                }
+
+                // 10 Bytes Entry Mode
+                if (!entries.Any())
+                {
+                    stream.Position = 0L;
+                    while (stream.Position < stream.Length)
+                    {
+                        string name = ReadString(stream);
+
+                        long offset = stream.ReadInt64() + 0x14L;
+                        stream.Position += 2L;
+                        long length = stream.ReadInt64();
+                        stream.Position += 2L;
+                        if (!CheckEntry(offset, length, file.MaxOffset))
+                        {
+                            entries.Clear();
+                            break;
+                        }
+
+                        PackedEntry entry = Create<PackedEntry>(name);
+                        entry.Offset = offset;
+                        entry.Size = (uint)length;
+                        entry.IsPacked = compressed;
+                        entries.Add(entry);
+
+                        stream.Seek(length, SeekOrigin.Current);
+                    }
+                }
+
+                return entries.Cast<Entry>().ToList();
+            }
+        }
+
+        private static string ReadString(ArcViewStream stream)
+        {
+            byte[] buf = new byte[0x20];
+            if (stream.Read(buf, 0, buf.Length) != buf.Length)
+            {
+                return string.Empty;
+            }
+
+            int len = Array.IndexOf<byte>(buf, 0);
+            if (len <= 0)
+            {
+                return string.Empty;
+            }
+
+            return Encoding.UTF8.GetString(buf, 0, len);
+        }
+
+        private static bool CheckEntry(long offset, long length, long max)
+        {
+            return offset >= 0L &&
+                   length >= 0L &&
+                   offset < max &&
+                   length <= max &&
+                   length <= uint.MaxValue &&
+                   offset <= max - length;
+        }
+    }
+}