Minor code refactoring

src/ImageSharp/Processing/Processors/PixelShading/Abstract/PixelShaderProcessorBase.cs

@@ -0,0 +1,64 @@
+// Copyright (c) Six Labors and contributors.
+// Licensed under the Apache License, Version 2.0.
+
+using System;
+using System.Numerics;
+
+using SixLabors.ImageSharp.Advanced;
+using SixLabors.ImageSharp.Advanced.ParallelUtils;
+using SixLabors.ImageSharp.PixelFormats;
+using SixLabors.Primitives;
+
+namespace SixLabors.ImageSharp.Processing.Processors.PixelShading.Abstract
+{
+    /// <summary>
+    /// Applies a user defined pixel shader effect through a given delegate.
+    /// </summary>
+    /// <typeparam name="TPixel">The pixel format.</typeparam>
+    internal abstract class PixelShaderProcessorBase<TPixel> : ImageProcessor<TPixel>
+        where TPixel : struct, IPixel<TPixel>
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="PixelShaderProcessorBase{TPixel}"/> class.
+        /// </summary>
+        /// <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 PixelShaderProcessorBase(Image<TPixel> source, Rectangle sourceRectangle)
+            : base(source, sourceRectangle)
+        { }
+
+        /// <inheritdoc/>
+        protected override void OnFrameApply(ImageFrame<TPixel> source)
+        {
+            var interest = Rectangle.Intersect(this.SourceRectangle, source.Bounds());
+            int startX = interest.X;
+
+            ParallelHelper.IterateRowsWithTempBuffer<Vector4>(
+                interest,
+                this.Configuration,
+                (rows, vectorBuffer) =>
+                {
+                    for (int y = rows.Min; y < rows.Max; y++)
+                    {
+                        Span<Vector4> vectorSpan = vectorBuffer.Span;
+                        int length = vectorSpan.Length;
+                        Span<TPixel> rowSpan = source.GetPixelRowSpan(y).Slice(startX, length);
+                        PixelOperations<TPixel>.Instance.ToVector4(this.Configuration, rowSpan, vectorSpan);
+
+                        // Run the user defined pixel shader on the current row of pixels
+                        this.ApplyPixelShader(vectorSpan, y, startX);
+
+                        PixelOperations<TPixel>.Instance.FromVector4Destructive(this.Configuration, vectorSpan, rowSpan);
+                    }
+                });
+        }
+
+        /// <summary>
+        /// Applies the current pixel shader effect on a target row of preprocessed pixels.
+        /// </summary>
+        /// <param name="span">The target row of <see cref="Vector4"/> pixels to process.</param>
+        /// <param name="offsetY">The initial vertical offset for the input pixels to process.</param>
+        /// <param name="offsetX">The initial horizontal offset for the input pixels to process.</param>
+        protected abstract void ApplyPixelShader(Span<Vector4> span, int offsetY, int offsetX);
+    }
+}

src/ImageSharp/Processing/Processors/PixelShading/PixelShaderProcessor{TPixel}.cs

@@ -4,10 +4,9 @@
 using System;
 using System.Numerics;
 
-using SixLabors.ImageSharp.Advanced;
-using SixLabors.ImageSharp.Advanced.ParallelUtils;
 using SixLabors.ImageSharp.PixelFormats;
 using SixLabors.ImageSharp.Processing.Delegates;
+using SixLabors.ImageSharp.Processing.Processors.PixelShading.Abstract;
 using SixLabors.Primitives;
 
 namespace SixLabors.ImageSharp.Processing.Processors.PixelShading
@@ -16,7 +15,7 @@ namespace SixLabors.ImageSharp.Processing.Processors.PixelShading
     /// Applies a user defined pixel shader effect through a given delegate.
     /// </summary>
     /// <typeparam name="TPixel">The pixel format.</typeparam>
-    internal class PixelShaderProcessor<TPixel> : ImageProcessor<TPixel>
+    internal class PixelShaderProcessor<TPixel> : PixelShaderProcessorBase<TPixel>
         where TPixel : struct, IPixel<TPixel>
     {
         /// <summary>
@@ -37,30 +36,6 @@ namespace SixLabors.ImageSharp.Processing.Processors.PixelShading
         }
 
         /// <inheritdoc/>
-        protected override void OnFrameApply(ImageFrame<TPixel> source)
-        {
-            var interest = Rectangle.Intersect(this.SourceRectangle, source.Bounds());
-            int startX = interest.X;
-            PixelShader pixelShader = this.pixelShader;
-
-            ParallelHelper.IterateRowsWithTempBuffer<Vector4>(
-                interest,
-                this.Configuration,
-                (rows, vectorBuffer) =>
-                {
-                    for (int y = rows.Min; y < rows.Max; y++)
-                    {
-                        Span<Vector4> vectorSpan = vectorBuffer.Span;
-                        int length = vectorSpan.Length;
-                        Span<TPixel> rowSpan = source.GetPixelRowSpan(y).Slice(startX, length);
-                        PixelOperations<TPixel>.Instance.ToVector4(this.Configuration, rowSpan, vectorSpan);
-
-                        // Run the user defined pixel shader on the current row of pixels
-                        pixelShader(vectorSpan);
-
-                        PixelOperations<TPixel>.Instance.FromVector4Destructive(this.Configuration, vectorSpan, rowSpan);
-                    }
-                });
-        }
+        protected override void ApplyPixelShader(Span<Vector4> span, int offsetY, int offsetX) => this.pixelShader(span);
     }
 }

src/ImageSharp/Processing/Processors/PixelShading/PositionAwarePixelShaderProcessor{TPixel}.cs

@@ -4,10 +4,9 @@
 using System;
 using System.Numerics;
 
-using SixLabors.ImageSharp.Advanced;
-using SixLabors.ImageSharp.Advanced.ParallelUtils;
 using SixLabors.ImageSharp.PixelFormats;
 using SixLabors.ImageSharp.Processing.Delegates;
+using SixLabors.ImageSharp.Processing.Processors.PixelShading.Abstract;
 using SixLabors.Primitives;
 
 namespace SixLabors.ImageSharp.Processing.Processors.PixelShading
@@ -16,7 +15,7 @@ namespace SixLabors.ImageSharp.Processing.Processors.PixelShading
     /// Applies a user defined pixel shader effect through a given delegate.
     /// </summary>
     /// <typeparam name="TPixel">The pixel format.</typeparam>
-    internal class PositionAwarePixelShaderProcessor<TPixel> : ImageProcessor<TPixel>
+    internal class PositionAwarePixelShaderProcessor<TPixel> : PixelShaderProcessorBase<TPixel>
         where TPixel : struct, IPixel<TPixel>
     {
         /// <summary>
@@ -37,29 +36,6 @@ namespace SixLabors.ImageSharp.Processing.Processors.PixelShading
         }
 
         /// <inheritdoc/>
-        protected override void OnFrameApply(ImageFrame<TPixel> source)
-        {
-            var interest = Rectangle.Intersect(this.SourceRectangle, source.Bounds());
-            int startX = interest.X;
-            PositionAwarePixelShader pixelShader = this.pixelShader;
-
-            ParallelHelper.IterateRowsWithTempBuffer<Vector4>(
-                interest,
-                this.Configuration,
-                (rows, vectorBuffer) =>
-                {
-                    for (int y = rows.Min; y < rows.Max; y++)
-                    {
-                        Span<Vector4> vectorSpan = vectorBuffer.Span;
-                        int length = vectorSpan.Length;
-                        Span<TPixel> rowSpan = source.GetPixelRowSpan(y).Slice(startX, length);
-                        PixelOperations<TPixel>.Instance.ToVector4(this.Configuration, rowSpan, vectorSpan);
-
-                        pixelShader(vectorSpan, y, startX);
-
-                        PixelOperations<TPixel>.Instance.FromVector4Destructive(this.Configuration, vectorSpan, rowSpan);
-                    }
-                });
-        }
+        protected override void ApplyPixelShader(Span<Vector4> span, int offsetY, int offsetX) => this.pixelShader(span, offsetY, offsetX);
     }
 }