implemented MG2 and MAL images.

ArcFormats/Valkyria/ImageMG2.cs

@@ -0,0 +1,145 @@
+//! \file       ImageMG2.cs
+//! \date       Sat Feb 25 03:08:01 2017
+//! \brief      Valkyria image format.
+//
+// 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.ComponentModel.Composition;
+using System.IO;
+using System.Windows.Media;
+using System.Windows.Media.Imaging;
+
+namespace GameRes.Formats.Valkyria
+{
+    internal class Mg2MetaData : ImageMetaData
+    {
+        public int ImageLength;
+        public int AlphaLength;
+    }
+
+    [Export(typeof(ImageFormat))]
+    public class Mg2Format : ImageFormat
+    {
+        public override string         Tag { get { return "MG2"; } }
+        public override string Description { get { return "Valkyria image format"; } }
+        public override uint     Signature { get { return 0x4F43494D; } } // 'MICO'
+
+        public override ImageMetaData ReadMetaData (IBinaryStream file)
+        {
+            var header = file.ReadHeader (0x10);
+            if (!header.AsciiEqual (4, "CG01"))
+                return null;
+            int length = header.ToInt32 (8);
+            using (var input = new Mg2EncryptedStream (file.AsStream, 0x10, length))
+            using (var png = new BinaryStream (input, file.Name))
+            {
+                var info = Png.ReadMetaData (png);
+                if (null == info)
+                    return null;
+                return new Mg2MetaData
+                {
+                    Width = info.Width,
+                    Height = info.Height,
+                    OffsetX = info.OffsetX,
+                    OffsetY = info.OffsetY,
+                    BPP = info.BPP,
+                    ImageLength = length,
+                    AlphaLength = header.ToInt32 (12)
+                };
+            }
+        }
+
+        public override ImageData Read (IBinaryStream file, ImageMetaData info)
+        {
+            var meta = (Mg2MetaData)info;
+            BitmapSource frame;
+            using (var input = new Mg2EncryptedStream (file.AsStream, 0x10, meta.ImageLength))
+            {
+                var decoder = new PngBitmapDecoder (input, BitmapCreateOptions.None, BitmapCacheOption.OnLoad);
+                frame = decoder.Frames[0];
+                if (0 == meta.AlphaLength)
+                {
+                    frame.Freeze();
+                    return new ImageData (frame, info);
+                }
+            }
+            if (frame.Format.BitsPerPixel != 32)
+                frame = new FormatConvertedBitmap (frame, PixelFormats.Bgr32, null, 0);
+            int stride = frame.PixelWidth * 4;
+            var pixels = new byte[stride * (int)meta.Height];
+            frame.CopyPixels (pixels, stride, 0);
+
+            using (var input = new Mg2EncryptedStream (file.AsStream, 0x10+meta.ImageLength, meta.AlphaLength))
+            {
+                var decoder = new PngBitmapDecoder (input, BitmapCreateOptions.None, BitmapCacheOption.OnLoad);
+                BitmapSource alpha_frame = decoder.Frames[0];
+                if (alpha_frame.PixelWidth != frame.PixelWidth || alpha_frame.PixelHeight != frame.PixelHeight)
+                    return ImageData.Create (info, PixelFormats.Bgr32, null, pixels, stride);
+
+                alpha_frame = new FormatConvertedBitmap (alpha_frame, PixelFormats.Gray8, null, 0);
+                var alpha = new byte[alpha_frame.PixelWidth * alpha_frame.PixelHeight];
+                alpha_frame.CopyPixels (alpha, alpha_frame.PixelWidth, 0);
+
+                int src = 0;
+                for (int dst = 3; dst < pixels.Length; dst += 4)
+                {
+                    pixels[dst] = alpha[src++];
+                }
+                return ImageData.Create (info, PixelFormats.Bgra32, null, pixels, stride);
+            }
+        }
+
+        public override void Write (Stream file, ImageData image)
+        {
+            throw new System.NotImplementedException ("Mg2Format.Write not implemented");
+        }
+    }
+
+    internal class Mg2EncryptedStream : StreamRegion
+    {
+        readonly int    m_threshold;
+
+        public Mg2EncryptedStream (Stream main, int offset, int length)
+            : base (main, offset, length, true)
+        {
+            m_threshold = length / 5;
+        }
+
+        public override int Read (byte[] buffer, int offset, int count)
+        {
+            int pos = (int)Position;
+            int read = base.Read (buffer, offset, count);
+            for (int i = 0; i < read && pos < m_threshold; ++i)
+                buffer[offset+i] ^= (byte)pos++;
+            return read;
+        }
+
+        public override int ReadByte ()
+        {
+            long pos = Position;
+            int b = base.ReadByte();
+            if (b != -1 && pos < m_threshold)
+                b ^= (byte)pos;
+            return b;
+        }
+    }
+}