ArcFormats: Support Rave RCG image format

ArcFormats/ArcFormats.csproj

@@ -205,6 +205,7 @@
     <Compile Include="GScripter\ArcDATA.cs" />
     <Compile Include="Guyzware\ArcDat.cs" />
     <Compile Include="ImageKTX.cs" />
+    <Compile Include="ImageRCG.cs" />
     <Compile Include="Ism\ImagePNG.cs" />
     <Compile Include="Kid\ArcDATRAW.cs" />
     <Compile Include="Kid\ArcKLZ.cs" />

ArcFormats/ImageRCG.cs

@@ -0,0 +1,64 @@
+using System.ComponentModel.Composition;
+using System.IO;
+using System.Windows.Media;
+using GameRes.Compression;
+
+namespace GameRes.Formats
+{
+    [Export(typeof(ImageFormat))]
+    public class ImageRCG : ImageFormat
+    {
+        public override string Tag
+        {
+            get { return "RCG"; }
+        }
+
+        public override string Description
+        {
+            get { return "Rave RCG image format"; }
+        }
+
+        public override uint Signature
+        {
+            get { return 0x31520018; }
+        }
+
+        public override bool CanWrite
+        {
+            get { return false; }
+        }
+
+        public override ImageMetaData ReadMetaData(IBinaryStream stream)
+        {
+            stream.Position = 4;
+            var meta = new ImageMetaData();
+            meta.BPP = 24;
+            meta.Width = stream.ReadUInt16();
+            meta.Height = stream.ReadUInt16();
+            meta.OffsetX = 0;
+            meta.OffsetY = 0;
+            // Skip 8 bytes unknown fields
+            stream.Position += 8;
+            var compressed_size = stream.ReadUInt32();
+            return compressed_size != stream.Length - 24 ? null : meta;
+        }
+
+        public override ImageData Read(IBinaryStream stream, ImageMetaData info)
+        {
+            stream.Position = 20;
+            var uncompressed_size = stream.ReadUInt32();
+            var data = new byte[uncompressed_size];
+            using (var zstream = new ZLibStream(stream.AsStream, CompressionMode.Decompress, true))
+            {
+                return uncompressed_size != zstream.Read(data, 0, (int)uncompressed_size)
+                    ? null
+                    : ImageData.Create(info, PixelFormats.Rgb24, null, data);
+            }
+        }
+
+        public override void Write(Stream file, ImageData image)
+        {
+            throw new System.NotImplementedException("RCGFormat.Write not implemented");
+        }
+    }
+}