GARbro-mirror/Legacy/CottonClub/ImageLMG.cs

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2023-08-24 05:33:50 +08:00
//! \file ImageLMG.cs
//! \date 2023 Aug 07
//! \brief Cotton Club encrypted image.
//
// Copyright (C) 2023 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.ComponentModel.Composition;
using System.IO;
using System.Windows.Media;
using System.Windows.Media.Imaging;
// [071231][Cotton Club] Kureuta
namespace GameRes.Formats.CottonClub
{
public class LmgMetaData : ImageMetaData
{
public byte Method;
}
[Export(typeof(ImageFormat))]
public class LmgFormat : ImageFormat
{
public override string Tag { get { return "LMG"; } }
public override string Description { get { return "Cotton Club encrypted image"; } }
public override uint Signature { get { return 0x03474D4C; } } // 'LMG'
public LmgFormat ()
{
Signatures = new uint[] { 0x03474D4C, 0x02474D4C, 0x01474D4C };
}
public override ImageMetaData ReadMetaData (IBinaryStream file)
{
var header = file.ReadHeader (12);
return new LmgMetaData {
Width = header.ToUInt32 (4),
Height = header.ToUInt32 (8),
BPP = header[3] == 2 ? 32 : 24,
Method = header[3],
};
}
public override ImageData Read (IBinaryStream file, ImageMetaData info)
{
var meta = (LmgMetaData)info;
var data = new byte[file.Length - 12];
file.Position = 12;
file.Read (data, 0, data.Length);
DecryptData (data, file.Name);
if (3 == meta.Method)
{
using (var input = new BinMemoryStream (data))
{
var decoder = new JpegBitmapDecoder (input, BitmapCreateOptions.None, BitmapCacheOption.OnLoad);
var frame = decoder.Frames[0];
frame.Freeze();
return new ImageData (frame, info);
}
}
else if (2 == meta.Method)
{
var reader = new LmgReader (info, data);
data = reader.Unpack();
return ImageData.Create (info, PixelFormats.Bgra32, null, data, reader.Stride);
}
else
{
return ImageData.Create (info, PixelFormats.Bgr24, null, data, info.iWidth * 3);
}
}
public override void Write (Stream file, ImageData image)
{
throw new System.NotImplementedException ("LmgFormat.Write not implemented");
}
internal void DecryptData (byte[] data, string filename)
{
filename = Path.GetFileName (filename).ToLowerInvariant();
byte key = 0;
for (int i = 0; i < filename.Length; ++i)
{
key ^= (byte)filename[i];
}
for (int i = 0; i < data.Length; ++i)
{
byte x = data[i];
data[i] ^= key;
key = x;
}
}
}
internal class LmgReader
{
byte[] m_data;
byte[] m_output;
int m_stride;
public int Stride { get { return m_stride; } }
public LmgReader (ImageMetaData info, byte[] data)
{
m_data = data;
m_stride = info.iWidth * 4;
m_output = new byte[m_stride * info.iHeight];
}
int m_src;
int m_dst;
public byte[] Unpack ()
{
m_src = 0;
m_dst = 0;
while (m_src+1 < m_data.Length)
{
byte alpha = m_data[m_src++];
if (0xFF == alpha)
{
int length = GetLength16();
for (int i = 0; i < length; ++i)
{
m_output[m_dst++] = m_data[m_src++];
m_output[m_dst++] = m_data[m_src++];
m_output[m_dst++] = m_data[m_src++];
m_output[m_dst++] = 0xFF;
}
}
else if (0 == alpha)
{
int length = GetLength16();
m_dst += length * 4;
}
else
{
ReadARGB (alpha);
}
}
return m_output;
}
void ReadARGB (byte alpha)
{
int length = GetLength8();
m_output[m_dst++] = m_data[m_src++];
m_output[m_dst++] = m_data[m_src++];
m_output[m_dst++] = m_data[m_src++];
m_output[m_dst++] = alpha;
while (--length > 0)
{
alpha = m_data[m_src++];
m_output[m_dst++] = m_data[m_src++];
m_output[m_dst++] = m_data[m_src++];
m_output[m_dst++] = m_data[m_src++];
m_output[m_dst++] = alpha;
}
}
int GetLength8 ()
{
int i = 0;
while (m_data[m_src] == 0)
{
i += 0xFF;
++m_src;
}
return i + m_data[m_src++];
}
int GetLength16 ()
{
int i = 0;
while (m_data[m_src] == 0 && m_data[m_src+1] == 0)
{
i += 0xFFFF;
m_src += 2;
}
i += m_data.ToUInt16 (m_src);
m_src += 2;
return i;
}
}
}