Major refactor to the pixel row delegate processors

src/ImageSharp/Processing/Processors/Effects/IPixelRowDelegate.cs

@@ -0,0 +1,21 @@
+// Copyright (c) Six Labors and contributors.
+// Licensed under the Apache License, Version 2.0.
+
+using System;
+using System.Numerics;
+
+namespace SixLabors.ImageSharp.Processing.Processors.Effects
+{
+    /// <summary>
+    /// An <see langword="interface"/> used by the row delegates for a given <see cref="PixelRowDelegateProcessor{TPixel,TDelegate}"/> instance
+    /// </summary>
+    public interface IPixelRowDelegate
+    {
+        /// <summary>
+        /// Applies the current pixel row delegate to a target row of preprocessed pixels.
+        /// </summary>
+        /// <param name="span">The target row of <see cref="Vector4"/> pixels to process.</param>
+        /// <param name="offset">The initial horizontal and vertical offset for the input pixels to process.</param>
+        void Invoke(Span<Vector4> span, Point offset);
+    }
+}

src/ImageSharp/Processing/Processors/Effects/PixelRowDelegateProcessor.cs

@@ -1,6 +1,9 @@
 // Copyright (c) Six Labors and contributors.
 // Licensed under the Apache License, Version 2.0.
 
+using System;
+using System.Numerics;
+using System.Runtime.CompilerServices;
 using SixLabors.ImageSharp.PixelFormats;
 
 namespace SixLabors.ImageSharp.Processing.Processors.Effects
@@ -34,6 +37,31 @@ namespace SixLabors.ImageSharp.Processing.Processors.Effects
         /// <inheritdoc />
         public IImageProcessor<TPixel> CreatePixelSpecificProcessor<TPixel>(Configuration configuration, Image<TPixel> source, Rectangle sourceRectangle)
             where TPixel : struct, IPixel<TPixel>
-            => new PixelRowDelegateProcessor<TPixel>(configuration, this, source, sourceRectangle);
+        {
+            return new PixelRowDelegateProcessor<TPixel, PixelRowDelegate>(
+                new PixelRowDelegate(this.PixelRowOperation),
+                configuration,
+                this.Modifiers,
+                source,
+                sourceRectangle);
+        }
+
+        /// <summary>
+        /// A <see langword="struct"/> implementing the row processing logic for <see cref="PixelRowDelegateProcessor"/>.
+        /// </summary>
+        public readonly struct PixelRowDelegate : IPixelRowDelegate
+        {
+            private readonly PixelRowOperation pixelRowOperation;
+
+            [MethodImpl(InliningOptions.ShortMethod)]
+            public PixelRowDelegate(PixelRowOperation pixelRowOperation)
+            {
+                this.pixelRowOperation = pixelRowOperation;
+            }
+
+            /// <inheritdoc/>
+            [MethodImpl(InliningOptions.ShortMethod)]
+            public void Invoke(Span<Vector4> span, Point offset) => this.pixelRowOperation(span);
+        }
     }
 }

src/ImageSharp/Processing/Processors/Effects/PixelRowDelegateProcessorBase{TPixel}.cs → src/ImageSharp/Processing/Processors/Effects/PixelRowDelegateProcessor{TPixel,TDelegate}.cs

@@ -14,24 +14,37 @@ namespace SixLabors.ImageSharp.Processing.Processors.Effects
     /// The base class for all processors that accept a user defined row processing delegate.
     /// </summary>
     /// <typeparam name="TPixel">The pixel format.</typeparam>
-    internal abstract class PixelRowDelegateProcessorBase<TPixel> : ImageProcessor<TPixel>
+    /// <typeparam name="TDelegate">The row processor type.</typeparam>
+    internal sealed class PixelRowDelegateProcessor<TPixel, TDelegate> : ImageProcessor<TPixel>
         where TPixel : struct, IPixel<TPixel>
+        where TDelegate : struct, IPixelRowDelegate
     {
+        private readonly TDelegate rowDelegate;
+
         /// <summary>
         /// The <see cref="PixelConversionModifiers"/> to apply during the pixel conversions.
         /// </summary>
         private readonly PixelConversionModifiers modifiers;
 
         /// <summary>
-        /// Initializes a new instance of the <see cref="PixelRowDelegateProcessorBase{TPixel}"/> class.
+        /// Initializes a new instance of the <see cref="PixelRowDelegateProcessor{TPixel,TDelegate}"/> class.
         /// </summary>
+        /// <param name="rowDelegate">The row processor to use to process each pixel row</param>
         /// <param name="configuration">The configuration which allows altering default behaviour or extending the library.</param>
         /// <param name="modifiers">The <see cref="PixelConversionModifiers"/> to apply during the pixel conversions.</param>
         /// <param name="source">The source <see cref="Image{TPixel}"/> for the current processor instance.</param>
         /// <param name="sourceRectangle">The source area to process for the current processor instance.</param>
-        protected PixelRowDelegateProcessorBase(Configuration configuration, PixelConversionModifiers modifiers, Image<TPixel> source, Rectangle sourceRectangle)
+        public PixelRowDelegateProcessor(
+            in TDelegate rowDelegate,
+            Configuration configuration,
+            PixelConversionModifiers modifiers,
+            Image<TPixel> source,
+            Rectangle sourceRectangle)
             : base(configuration, source, sourceRectangle)
-            => this.modifiers = modifiers;
+        {
+            this.rowDelegate = rowDelegate;
+            this.modifiers = modifiers;
+        }
 
         /// <inheritdoc/>
         protected override void OnFrameApply(ImageFrame<TPixel> source)
@@ -41,18 +54,11 @@ namespace SixLabors.ImageSharp.Processing.Processors.Effects
             ParallelRowIterator.IterateRows<RowIntervalAction, Vector4>(
                 interest,
                 this.Configuration,
-                new RowIntervalAction(interest.X, source, this.Configuration, this.modifiers, this));
+                new RowIntervalAction(interest.X, source, this.Configuration, this.modifiers, this.rowDelegate));
         }
 
         /// <summary>
-        /// Applies the current pixel row delegate to a target row of preprocessed pixels.
+        /// A <see langword="struct"/> implementing the convolution logic for <see cref="PixelRowDelegateProcessor{TPixel,TDelegate}"/>.
-        /// </summary>
-        /// <param name="span">The target row of <see cref="Vector4"/> pixels to process.</param>
-        /// <param name="offset">The initial horizontal and vertical offset for the input pixels to process.</param>
-        protected abstract void ApplyPixelRowDelegate(Span<Vector4> span, Point offset);
-
-        /// <summary>
-        /// A <see langword="struct"/> implementing the convolution logic for <see cref="PixelRowDelegateProcessorBase{T}"/>.
         /// </summary>
         private readonly struct RowIntervalAction : IRowIntervalAction<Vector4>
         {
@@ -60,7 +66,7 @@ namespace SixLabors.ImageSharp.Processing.Processors.Effects
             private readonly ImageFrame<TPixel> source;
             private readonly Configuration configuration;
             private readonly PixelConversionModifiers modifiers;
-            private readonly PixelRowDelegateProcessorBase<TPixel> processor;
+            private readonly TDelegate rowProcessor;
 
             [MethodImpl(InliningOptions.ShortMethod)]
             public RowIntervalAction(
@@ -68,13 +74,13 @@ namespace SixLabors.ImageSharp.Processing.Processors.Effects
                 ImageFrame<TPixel> source,
                 Configuration configuration,
                 PixelConversionModifiers modifiers,
-                PixelRowDelegateProcessorBase<TPixel> processor)
+                in TDelegate rowProcessor)
             {
                 this.startX = startX;
                 this.source = source;
                 this.configuration = configuration;
                 this.modifiers = modifiers;
-                this.processor = processor;
+                this.rowProcessor = rowProcessor;
             }
 
             /// <inheritdoc/>
@@ -89,7 +95,7 @@ namespace SixLabors.ImageSharp.Processing.Processors.Effects
                     PixelOperations<TPixel>.Instance.ToVector4(this.configuration, rowSpan, vectorSpan, this.modifiers);
 
                     // Run the user defined pixel shader to the current row of pixels
-                    this.processor.ApplyPixelRowDelegate(vectorSpan, new Point(this.startX, y));
+                    this.rowProcessor.Invoke(vectorSpan, new Point(this.startX, y));
 
                     PixelOperations<TPixel>.Instance.FromVector4Destructive(this.configuration, vectorSpan, rowSpan, this.modifiers);
                 }

src/ImageSharp/Processing/Processors/Effects/PixelRowDelegateProcessor{TPixel}.cs

@@ -1,39 +0,0 @@
-// Copyright (c) Six Labors and contributors.
-// Licensed under the Apache License, Version 2.0.
-
-using System;
-using System.Numerics;
-
-using SixLabors.ImageSharp.PixelFormats;
-
-namespace SixLabors.ImageSharp.Processing.Processors.Effects
-{
-    /// <summary>
-    /// Applies a user defined row processing delegate to the image.
-    /// </summary>
-    /// <typeparam name="TPixel">The pixel format.</typeparam>
-    internal sealed class PixelRowDelegateProcessor<TPixel> : PixelRowDelegateProcessorBase<TPixel>
-        where TPixel : struct, IPixel<TPixel>
-    {
-        /// <summary>
-        /// The user defined pixel row processing delegate.
-        /// </summary>
-        private readonly PixelRowOperation pixelRowOperation;
-
-        /// <summary>
-        /// Initializes a new instance of the <see cref="PixelRowDelegateProcessor{TPixel}"/> class.
-        /// </summary>
-        /// <param name="configuration">The configuration which allows altering default behaviour or extending the library.</param>
-        /// <param name="definition">The <see cref="PixelRowDelegateProcessor"/> defining the processor parameters.</param>
-        /// <param name="source">The source <see cref="Image{TPixel}"/> for the current processor instance.</param>
-        /// <param name="sourceRectangle">The source area to process for the current processor instance.</param>
-        public PixelRowDelegateProcessor(Configuration configuration, PixelRowDelegateProcessor definition, Image<TPixel> source, Rectangle sourceRectangle)
-            : base(configuration, definition.Modifiers, source, sourceRectangle)
-        {
-            this.pixelRowOperation = definition.PixelRowOperation;
-        }
-
-        /// <inheritdoc/>
-        protected override void ApplyPixelRowDelegate(Span<Vector4> span, Point offset) => this.pixelRowOperation(span);
-    }
-}

src/ImageSharp/Processing/Processors/Effects/PositionAwarePixelRowDelegateProcessor.cs

@@ -1,6 +1,9 @@
 // Copyright (c) Six Labors and contributors.
 // Licensed under the Apache License, Version 2.0.
 
+using System;
+using System.Numerics;
+using System.Runtime.CompilerServices;
 using SixLabors.ImageSharp.PixelFormats;
 
 namespace SixLabors.ImageSharp.Processing.Processors.Effects
@@ -34,6 +37,31 @@ namespace SixLabors.ImageSharp.Processing.Processors.Effects
         /// <inheritdoc />
         public IImageProcessor<TPixel> CreatePixelSpecificProcessor<TPixel>(Configuration configuration, Image<TPixel> source, Rectangle sourceRectangle)
             where TPixel : struct, IPixel<TPixel>
-            => new PositionAwarePixelRowDelegateProcessor<TPixel>(configuration, this, source, sourceRectangle);
+        {
+            return new PixelRowDelegateProcessor<TPixel, PixelRowDelegate>(
+                new PixelRowDelegate(this.PixelRowOperation),
+                configuration,
+                this.Modifiers,
+                source,
+                sourceRectangle);
+        }
+
+        /// <summary>
+        /// A <see langword="struct"/> implementing the row processing logic for <see cref="PositionAwarePixelRowDelegateProcessor"/>.
+        /// </summary>
+        public readonly struct PixelRowDelegate : IPixelRowDelegate
+        {
+            private readonly PixelRowOperation<Point> pixelRowOperation;
+
+            [MethodImpl(InliningOptions.ShortMethod)]
+            public PixelRowDelegate(PixelRowOperation<Point> pixelRowOperation)
+            {
+                this.pixelRowOperation = pixelRowOperation;
+            }
+
+            /// <inheritdoc/>
+            [MethodImpl(InliningOptions.ShortMethod)]
+            public void Invoke(Span<Vector4> span, Point offset) => this.pixelRowOperation(span, offset);
+        }
     }
 }

src/ImageSharp/Processing/Processors/Effects/PositionAwarePixelRowDelegateProcessor{TPixel}.cs

@@ -1,36 +0,0 @@
-// Copyright (c) Six Labors and contributors.
-// Licensed under the Apache License, Version 2.0.
-
-using System;
-using System.Numerics;
-
-using SixLabors.ImageSharp.PixelFormats;
-
-namespace SixLabors.ImageSharp.Processing.Processors.Effects
-{
-    /// <summary>
-    /// Applies a user defined, position aware, row processing delegate to the image.
-    /// </summary>
-    /// <typeparam name="TPixel">The pixel format.</typeparam>
-    internal sealed class PositionAwarePixelRowDelegateProcessor<TPixel> : PixelRowDelegateProcessorBase<TPixel>
-        where TPixel : struct, IPixel<TPixel>
-    {
-        private readonly PixelRowOperation<Point> pixelRowOperation;
-
-        /// <summary>
-        /// Initializes a new instance of the <see cref="PositionAwarePixelRowDelegateProcessor{TPixel}"/> class.
-        /// </summary>
-        /// <param name="configuration">The configuration which allows altering default behaviour or extending the library.</param>
-        /// <param name="definition">The <see cref="PositionAwarePixelRowDelegateProcessor"/> defining the processor parameters.</param>
-        /// <param name="source">The source <see cref="Image{TPixel}"/> for the current processor instance.</param>
-        /// <param name="sourceRectangle">The source area to process for the current processor instance.</param>
-        public PositionAwarePixelRowDelegateProcessor(Configuration configuration, PositionAwarePixelRowDelegateProcessor definition, Image<TPixel> source, Rectangle sourceRectangle)
-            : base(configuration, definition.Modifiers, source, sourceRectangle)
-        {
-            this.pixelRowOperation = definition.PixelRowOperation;
-        }
-
-        /// <inheritdoc/>
-        protected override void ApplyPixelRowDelegate(Span<Vector4> span, Point offset) => this.pixelRowOperation(span, offset);
-    }
-}