GARbro-mirror/ArcFormats/AZSys/ArcAZSys.cs

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//! \file ArcAZSys.cs
//! \date Wed Apr 22 09:52:23 2015
//! \brief AZ system archive implementation.
//
// Copyright (C) 2015 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.Compression;
using GameRes.Formats.Strings;
using GameRes.Utility;
namespace GameRes.Formats.AZSys
{
[Export(typeof(ArchiveFormat))]
public class ArcOpener : ArchiveFormat
{
public override string Tag { get { return "ARC/AZ"; } }
public override string Description { get { return "AZ system resource archive"; } }
public override uint Signature { get { return 0x1a435241; } } // 'ARC\x1a'
public override bool IsHierarchic { get { return false; } }
public override bool CanCreate { get { return false; } }
public ArcOpener ()
{
Extensions = new string[] { "arc" };
}
public override ArcFile TryOpen (ArcView file)
{
int ext_count = file.View.ReadInt32 (4);
int count = file.View.ReadInt32 (8);
uint index_length = file.View.ReadUInt32 (12);
if (ext_count < 1 || ext_count > 8 || count <= 0 || count > 0xfffff
|| index_length <= 0x14 || index_length >= file.MaxOffset)
return null;
var packed_index = new byte[index_length];
if ((int)index_length != file.View.Read (0x30, packed_index, 0, index_length))
return null;
uint base_offset = 0x30 + index_length;
uint crc = LittleEndian.ToUInt32 (packed_index, 0);
if (crc != Crc32.Compute (packed_index, 0x14, packed_index.Length-0x14))
throw new InvalidFormatException ("CRC32 mismatch");
var reader = new IndexReader (packed_index, count);
var index = reader.Unpack();
int index_offset = 0;
var dir = new List<Entry> (count);
for (int i = 0; i < count; ++i)
{
var name = Binary.GetCString (index, index_offset + 0x10, 0x30);
if (name.Length > 0)
{
var entry = FormatCatalog.Instance.Create<Entry> (name);
entry.Offset = base_offset + LittleEndian.ToUInt32 (index, index_offset);
entry.Size = LittleEndian.ToUInt32 (index, index_offset + 4);
if (entry.CheckPlacement (file.MaxOffset))
dir.Add (entry);
}
index_offset += 0x40;
}
if (0 == dir.Count)
return null;
return new ArcFile (file, this, dir);
}
static readonly uint[] KnownKeys = new uint[] { 0x1de71cb9 }; // Triptych
public override Stream OpenEntry (ArcFile arc, Entry entry)
{
if (entry.Size < 20
|| !entry.Name.EndsWith (".asb", StringComparison.InvariantCultureIgnoreCase)
|| !arc.File.View.AsciiEqual (entry.Offset, "ASB\x1a"))
return arc.File.CreateStream (entry.Offset, entry.Size);
uint packed = arc.File.View.ReadUInt32 (entry.Offset+4);
uint unpacked = arc.File.View.ReadUInt32 (entry.Offset+8);
if (12 + packed != entry.Size)
return arc.File.CreateStream (entry.Offset, entry.Size);
uint key = KnownKeys[0] ^ unpacked;
key ^= ((key << 12) | key) << 11;
uint first = arc.File.View.ReadUInt16 (entry.Offset+16);
first = (first - key) & 0xffff;
if (first != 0xda78) // doesn't look like zlib stream
return arc.File.CreateStream (entry.Offset, entry.Size);
byte[] input = new byte[packed];
arc.File.View.Read (entry.Offset+12, input, 0, packed);
unsafe
{
fixed (byte* raw = input)
{
uint* encoded = (uint*)raw;
for (int i = 0; i < input.Length/4; ++i)
encoded[i] -= key;
}
}
// first 4 bytes are CRC32 of the compressed stream
uint checksum = LittleEndian.ToUInt32 (input, 0);
if (checksum != Crc32.Compute (input, 4, input.Length-4))
return arc.File.CreateStream (entry.Offset, entry.Size);
return new ZLibStream (new MemoryStream (input, 4, input.Length-4), CompressionMode.Decompress);
}
internal class IndexReader
{
byte[] m_input;
byte[] m_output;
int m_control_len;
int m_compr1_len;
int m_compr2_len;
int m_output_len;
public byte[] Index { get { return m_output; } }
public IndexReader (byte[] packed, int count)
{
m_input = packed;
m_output = new byte[count*0x40];
m_control_len = LittleEndian.ToInt32 (packed, 4);
m_compr1_len = LittleEndian.ToInt32 (packed, 8);
m_compr2_len = LittleEndian.ToInt32 (packed, 12);
m_output_len = LittleEndian.ToInt32 (packed, 0x10);
}
public byte[] Unpack ()
{
int control = 0x14;
int compr1 = control + m_control_len;
int compr2 = compr1 + m_compr1_len;
int dst = 0;
byte mask = 0x80;
int copy_count;
while (dst < m_output.Length)
{
if (0 != (m_input[control] & mask))
{
int offset = LittleEndian.ToUInt16 (m_input, compr1);
compr1 += 2;
copy_count = (offset >> 13) + 3;
offset &= 0x1fff;
offset++;
Binary.CopyOverlapped (m_output, dst-offset, dst, copy_count);
dst += copy_count;
}
else
{
copy_count = m_input[compr2++] + 1;
Buffer.BlockCopy (m_input, compr2, m_output, dst, copy_count);
compr2 += copy_count;
dst += copy_count;
}
mask >>= 1;
if (0 == mask)
{
++control;
mask = 0x80;
}
}
return m_output;
}
}
}
}