GARbro-mirror/ArcFormats/VnSystem/ArcVFS.cs
2017-01-19 04:25:24 +04:00

128 lines
5.0 KiB
C#

//! \file ArcVFS.cs
//! \date Wed Jan 18 21:30:30 2017
//! \brief VNSystem engine resource archive.
//
// Copyright (C) 2017 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;
namespace GameRes.Formats.VnSystem
{
[Export(typeof(ArchiveFormat))]
public class VfsOpener : ArchiveFormat
{
public override string Tag { get { return "VFS/VNSYSTEM"; } }
public override string Description { get { return "VNSystem engine resource archive"; } }
public override uint Signature { get { return 0x20534656; } } // 'VFS File'
public override bool IsHierarchic { get { return false; } }
public override bool CanWrite { get { return false; } }
public override ArcFile TryOpen (ArcView file)
{
if (!file.View.AsciiEqual (4, "File"))
return null;
bool is_compressed = file.View.ReadInt32 (8) != 0;
int count = file.View.ReadInt32 (12);
if (!IsSaneCount (count))
return null;
uint index_offset = 0x10;
long data_offset = index_offset + count * 0x1C;
var dir = new List<Entry> (count);
for (int i = 0; i < count; ++i)
{
var name = file.View.ReadString (index_offset, 0x14);
index_offset += 0x14;
var entry = FormatCatalog.Instance.Create<PackedEntry> (name);
entry.Offset = data_offset + file.View.ReadUInt32 (index_offset);
entry.Size = file.View.ReadUInt32 (index_offset+4);
if (!entry.CheckPlacement (file.MaxOffset))
return null;
entry.IsPacked = is_compressed;
dir.Add (entry);
index_offset += 8;
}
return new ArcFile (file, this, dir);
}
public override Stream OpenEntry (ArcFile arc, Entry entry)
{
var pent = entry as PackedEntry;
if (null == pent || !pent.IsPacked)
return arc.File.CreateStream (entry.Offset, entry.Size);
if (0 == pent.UnpackedSize)
pent.UnpackedSize = arc.File.View.ReadUInt32 (entry.Offset);
using (var input = arc.File.CreateStream (entry.Offset+4, entry.Size-4))
{
var data = UnpackEntry (input, pent.UnpackedSize);
return new BinMemoryStream (data, entry.Name);
}
}
byte[] UnpackEntry (Stream input, uint unpacked_size)
{
const int dict_size = 0x10;
var output = new byte[unpacked_size];
using (var bits = new MsbBitStream (input, true))
{
var dict = new byte[dict_size];
int dict_pos = 0;
for (int dst = 0; dst < output.Length; ++dst)
{
byte cur_byte;
if (bits.GetNextBit() != 0)
{
int offset = GetBitLength (bits);
int pos = dict_pos - offset;
if (pos < 0)
pos += dict_size;
if (pos < 0 || pos >= dict_size)
throw new InvalidDataException ("Invalid compressed data.");
cur_byte = dict[pos];
}
else
{
cur_byte = (byte)bits.GetBits (8);
}
output[dst] = cur_byte;
dict[dict_pos++] = cur_byte;
dict_pos &= 0xF;
}
}
return output;
}
static int GetBitLength (IBitStream input)
{
int count = 0;
while (0 == input.GetNextBit())
++count;
int n = 1 << count;
if (count > 0)
n |= input.GetBits (count);
return n;
}
}
}