GARbro-mirror/ArcFormats/EmonEngine/ArcEME.cs

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2016-03-16 08:20:52 +08:00
//! \file ArcEME.cs
//! \date Tue Mar 15 08:13:00 2016
//! \brief Emon Engine (えもんエンジン) resource archives.
//
// Copyright (C) 2016 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 System.Text;
using GameRes.Compression;
using GameRes.Utility;
namespace GameRes.Formats.EmonEngine
{
[Export(typeof(ArchiveFormat))]
public class EmeOpener : ArchiveFormat
{
public override string Tag { get { return "EME"; } }
public override string Description { get { return "Emon Engine resource archive"; } } // 'えもんエンジン'
public override uint Signature { get { return 0x44455252; } } // 'RREDATA'
public override bool IsHierarchic { get { return false; } }
public override bool CanCreate { get { return false; } }
public override ArcFile TryOpen (ArcView file)
{
if (!file.View.AsciiEqual (4, "ATA "))
return null;
int count = file.View.ReadInt32 (file.MaxOffset-4);
if (!IsSaneCount (count))
return null;
uint index_size = (uint)count * 0x60;
var index_offset = file.MaxOffset - 4 - index_size;
var key = file.View.ReadBytes (index_offset - 40, 40);
var index = file.View.ReadBytes (index_offset, index_size);
int current_offset = 0;
var dir = new List<Entry> (count);
for (int i = 0; i < count; ++i)
{
Decrypt (index, current_offset, 0x60, key);
var name = Binary.GetCString (index, current_offset, 0x40);
var entry = FormatCatalog.Instance.Create<EmEntry> (name);
entry.LzssFrameSize = LittleEndian.ToUInt16 (index, current_offset+0x40);
entry.LzssInitPos = LittleEndian.ToUInt16 (index, current_offset+0x42);
if (entry.LzssFrameSize != 0)
entry.LzssInitPos = (entry.LzssFrameSize - entry.LzssInitPos) % entry.LzssFrameSize;
entry.SubType = LittleEndian.ToInt32 (index, current_offset+0x48);
entry.Size = LittleEndian.ToUInt32 (index, current_offset+0x4C);
entry.UnpackedSize = LittleEndian.ToUInt32 (index, current_offset+0x50);
entry.Offset = LittleEndian.ToUInt32 (index, current_offset+0x54);
if (!entry.CheckPlacement (file.MaxOffset))
return null;
if (3 == entry.SubType)
entry.Type = "script";
else if (4 == entry.SubType)
entry.Type = "image";
dir.Add (entry);
current_offset += 0x60;
}
return new EmeArchive (file, this, dir, key);
}
public override Stream OpenEntry (ArcFile arc, Entry entry)
{
var ement = entry as EmEntry;
var emarc = arc as EmeArchive;
if (null == ement || null == emarc)
return base.OpenEntry (arc, entry);
if (3 == ement.SubType)
return OpenScript (emarc, ement);
else if (4 == ement.SubType)
return OpenImage (emarc, ement);
else if (5 == ement.SubType && entry.Size > 4)
return OpenT5 (emarc, ement);
else
return base.OpenEntry (arc, entry);
}
Stream OpenScript (EmeArchive arc, EmEntry entry)
{
var header = arc.File.View.ReadBytes (entry.Offset, 12);
Decrypt (header, 0, 12, arc.Key);
if (0 == entry.LzssFrameSize)
{
var input = arc.File.CreateStream (entry.Offset+12, entry.Size);
return new PrefixStream (header, input);
}
int unpacked_size = LittleEndian.ToInt32 (header, 4);
if (0 != unpacked_size)
{
uint packed_size = LittleEndian.ToUInt32 (header, 0);
int part1_size = (int)entry.UnpackedSize - unpacked_size;
var data = new byte[entry.UnpackedSize];
using (var input = arc.File.CreateStream (entry.Offset+12+packed_size, entry.Size))
using (var lzss = new LzssStream (input))
{
lzss.Config.FrameSize = entry.LzssFrameSize;
lzss.Config.FrameInitPos = entry.LzssInitPos;
lzss.Read (data, 0, part1_size);
}
using (var input = arc.File.CreateStream (entry.Offset+12, packed_size))
using (var lzss = new LzssStream (input))
{
lzss.Config.FrameSize = entry.LzssFrameSize;
lzss.Config.FrameInitPos = entry.LzssInitPos;
lzss.Read (data, part1_size, unpacked_size);
}
return new MemoryStream (data);
}
else
{
var input = arc.File.CreateStream (entry.Offset+12, entry.Size);
var lzss = new LzssStream (input);
lzss.Config.FrameSize = entry.LzssFrameSize;
lzss.Config.FrameInitPos = entry.LzssInitPos;
return lzss;
}
}
Stream OpenImage (EmeArchive arc, EmEntry entry)
{
var header = new byte[40];
Encoding.ASCII.GetBytes ("EMBM", 0, 4, header, 0);
LittleEndian.Pack ((ushort)entry.LzssFrameSize, header, 4);
LittleEndian.Pack ((ushort)entry.LzssInitPos, header, 6);
arc.File.View.Read (entry.Offset, header, 8, 32);
Decrypt (header, 8, 32, arc.Key);
uint entry_size = entry.Size;
uint colors = LittleEndian.ToUInt16 (header, 14);
if (0 != colors && header[0] != 7)
entry_size += Math.Max (colors, 3u) * 4;
var input = arc.File.CreateStream (entry.Offset+32, entry_size);
return new PrefixStream (header, input);
}
Stream OpenT5 (EmeArchive arc, EmEntry entry)
{
var header = arc.File.View.ReadBytes (entry.Offset, 4);
Decrypt (header, 0, 4, arc.Key);
var input = arc.File.CreateStream (entry.Offset+4, entry.Size-4);
return new PrefixStream (header, input);
}
internal static unsafe void Decrypt (byte[] buffer, int offset, int length, byte[] routine)
{
if (null == buffer)
throw new ArgumentNullException ("buffer", "Buffer cannot be null.");
if (offset < 0)
throw new ArgumentOutOfRangeException ("offset", "Buffer offset should be non-negative.");
if (buffer.Length - offset < length)
throw new ArgumentException ("Buffer offset and length are out of bounds.");
fixed (byte* data8 = &buffer[offset])
{
uint* data32 = (uint*)data8;
int length32 = length / 4;
int key_index = routine.Length;
for (int i = 7; i >= 0; --i)
{
key_index -= 4;
uint key = LittleEndian.ToUInt32 (routine, key_index);
switch (routine[i])
{
case 1:
for (int j = 0; j < length32; ++j)
data32[j] ^= key;
break;
case 2:
for (int j = 0; j < length32; ++j)
{
uint v = data32[j];
data32[j] = v ^ key;
key = v;
}
break;
case 4:
for (int j = 0; j < length32; ++j)
data32[j] = ShiftValue (data32[j], key);
break;
case 8:
InitTable (buffer, offset, length, key);
break;
}
}
}
}
static uint ShiftValue (uint val, uint key)
{
int shift = 0;
uint result = 0;
for (int i = 0; i < 32; ++i)
{
shift += (int)key;
result |= ((val >> i) & 1) << shift;
}
return result;
}
static void InitTable (byte[] buffer, int offset, int length, uint key)
{
var table = new byte[length];
int x = 0;
for (int i = 0; i < length; ++i)
{
x += (int)key;
while (x >= length)
x -= length;
table[x] = buffer[offset+i];
}
Buffer.BlockCopy (table, 0, buffer, offset, length);
}
}
internal class EmEntry : PackedEntry
{
public int LzssFrameSize;
public int LzssInitPos;
public int SubType;
}
internal class EmeArchive : ArcFile
{
public readonly byte[] Key;
public EmeArchive (ArcView arc, ArchiveFormat impl, ICollection<Entry> dir, byte[] key)
: base (arc, impl, dir)
{
Key = key;
}
}
}