introduce decoderCore classes (without implementation)

src/ImageSharp/Formats/WebP/ExtendedDecoder.cs

@@ -0,0 +1,14 @@
+// Copyright (c) Six Labors and contributors.
+// Licensed under the Apache License, Version 2.0.
+
+using System;
+using System.IO;
+
+namespace SixLabors.ImageSharp.Formats.WebP
+{
+    class ExtendedDecoderCore : WebPDecoderCoreBase
+    {
+        public override Image<TPixel> Decode<TPixel>(Stream stream)
+            => throw new NotImplementedException();
+    }
+}

src/ImageSharp/Formats/WebP/SimpleLosslessDecoder.cs

@@ -0,0 +1,14 @@
+// Copyright (c) Six Labors and contributors.
+// Licensed under the Apache License, Version 2.0.
+
+using System;
+using System.IO;
+
+namespace SixLabors.ImageSharp.Formats.WebP
+{
+    class SimpleLosslessDecoder : WebPDecoderCoreBase
+    {
+        public override Image<TPixel> Decode<TPixel>(Stream stream)
+            => throw new NotImplementedException();
+    }
+}

src/ImageSharp/Formats/WebP/SimpleLossyDecoder.cs

@@ -0,0 +1,14 @@
+// Copyright (c) Six Labors and contributors.
+// Licensed under the Apache License, Version 2.0.
+
+using System;
+using System.IO;
+
+namespace SixLabors.ImageSharp.Formats.WebP
+{
+    class SimpleLossyDecoder : WebPDecoderCoreBase
+    {
+        public override Image<TPixel> Decode<TPixel>(Stream stream)
+            => throw new NotImplementedException();
+    }
+}

src/ImageSharp/Formats/WebP/WebPDecoder.cs

@@ -15,6 +15,7 @@ namespace SixLabors.ImageSharp.Formats.WebP
         public Image<TPixel> Decode<TPixel>(Configuration configuration, Stream stream)
             where TPixel : struct, IPixel<TPixel>
         {
+            // TODO: [brianpopow] parse chunks and decide which decoder (subclass of WebPDecoderCoreBase) to use
             throw new System.NotImplementedException();
         }
 

src/ImageSharp/Formats/WebP/WebPDecoderCoreBase.cs

@@ -0,0 +1,18 @@
+// Copyright (c) Six Labors and contributors.
+// Licensed under the Apache License, Version 2.0.
+
+using System.IO;
+
+using SixLabors.ImageSharp.PixelFormats;
+
+namespace SixLabors.ImageSharp.Formats.WebP
+{
+    /// <summary>
+    /// Base class for the WebP image decoders.
+    /// </summary>
+    public abstract class WebPDecoderCoreBase
+    {
+        public abstract Image<TPixel> Decode<TPixel>(Stream stream)
+            where TPixel : struct, IPixel<TPixel>;
+    }
+}