Use Point for offset

src/ImageSharp/Processing/PositionAwarePixelShader.cs

@@ -3,6 +3,7 @@
 
 using System;
 using System.Numerics;
+using SixLabors.Primitives;
 
 namespace SixLabors.ImageSharp.Processing
 {
@@ -10,8 +11,7 @@ namespace SixLabors.ImageSharp.Processing
     /// A <see langword="delegate"/> representing a user defined pixel shader.
     /// </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>
+    /// <param name="offset">The initial horizontal and vertical offset for the input pixels to process.</param>
     /// <remarks>The <see cref="Vector4.X"/>, <see cref="Vector4.Y"/>, <see cref="Vector4.Z"/>, and <see cref="Vector4.W"/> fields map the RGBA channels respectively.</remarks>
-    public delegate void PositionAwarePixelShader(Span<Vector4> span, int offsetY, int offsetX);
+    public delegate void PositionAwarePixelShader(Span<Vector4> span, Point offset);
 }

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

@@ -56,7 +56,7 @@ namespace SixLabors.ImageSharp.Processing.Processors.Effects
                         PixelOperations<TPixel>.Instance.ToVector4(configuration, rowSpan, vectorSpan, modifiers);
 
                         // Run the user defined pixel shader on the current row of pixels
-                        this.ApplyPixelShader(vectorSpan, y, startX);
+                        this.ApplyPixelShader(vectorSpan, new Point(startX, y));
 
                         PixelOperations<TPixel>.Instance.FromVector4Destructive(configuration, vectorSpan, rowSpan, modifiers);
                     }
@@ -67,8 +67,7 @@ namespace SixLabors.ImageSharp.Processing.Processors.Effects
         /// 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);
+        /// <param name="offset">The initial horizontal and vertical offset for the input pixels to process.</param>
+        protected abstract void ApplyPixelShader(Span<Vector4> span, Point offset);
     }
 }

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

@@ -13,7 +13,7 @@ namespace SixLabors.ImageSharp.Processing.Processors.Effects
     /// Applies a user defined pixel shader effect through a given delegate.
     /// </summary>
     /// <typeparam name="TPixel">The pixel format.</typeparam>
-    internal class PixelShaderProcessor<TPixel> : PixelShaderProcessorBase<TPixel>
+    internal sealed class PixelShaderProcessor<TPixel> : PixelShaderProcessorBase<TPixel>
         where TPixel : struct, IPixel<TPixel>
     {
         /// <summary>
@@ -34,6 +34,6 @@ namespace SixLabors.ImageSharp.Processing.Processors.Effects
         }
 
         /// <inheritdoc/>
-        protected override void ApplyPixelShader(Span<Vector4> span, int offsetY, int offsetX) => this.pixelShader(span);
+        protected override void ApplyPixelShader(Span<Vector4> span, Point offset) => this.pixelShader(span);
     }
 }

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

@@ -13,7 +13,7 @@ namespace SixLabors.ImageSharp.Processing.Processors.Effects
     /// Applies a user defined pixel shader effect through a given delegate.
     /// </summary>
     /// <typeparam name="TPixel">The pixel format.</typeparam>
-    internal class PositionAwarePixelShaderProcessor<TPixel> : PixelShaderProcessorBase<TPixel>
+    internal sealed class PositionAwarePixelShaderProcessor<TPixel> : PixelShaderProcessorBase<TPixel>
         where TPixel : struct, IPixel<TPixel>
     {
         /// <summary>
@@ -34,6 +34,6 @@ namespace SixLabors.ImageSharp.Processing.Processors.Effects
         }
 
         /// <inheritdoc/>
-        protected override void ApplyPixelShader(Span<Vector4> span, int offsetY, int offsetX) => this.pixelShader(span, offsetY, offsetX);
+        protected override void ApplyPixelShader(Span<Vector4> span, Point offset) => this.pixelShader(span, offset);
     }
 }

tests/ImageSharp.Tests/Processing/Processors/Effects/PixelShaderTest.cs

@@ -58,8 +58,10 @@ namespace SixLabors.ImageSharp.Tests.Processing.Processors.Effects
         {
             provider.RunValidatingProcessorTest(
                 c => c.ApplyPixelShaderProcessor(
-                    (span, y, x) =>
+                    (span, offset) =>
                     {
+                        int y = offset.Y;
+                        int x = offset.X;
                         for (int i = 0; i < span.Length; i++)
                         {
                             float
@@ -67,8 +69,8 @@ namespace SixLabors.ImageSharp.Tests.Processing.Processors.Effects
                                 cosine = MathF.Cos(x + i),
                                 sum = sine + cosine,
                                 abs = MathF.Abs(sum),
-                                a = 0.5f + abs / 2; // Max value for sin(y) + cos(x) is 2
-                                
+                                a = 0.5f + (abs / 2); // Max value for sin(y) + cos(x) is 2
+
                             Vector4 v4 = span[i];
                             float avg = (v4.X + v4.Y + v4.Z) / 3f;
                             var gray = new Vector4(avg, avg, avg, a);
@@ -86,8 +88,10 @@ namespace SixLabors.ImageSharp.Tests.Processing.Processors.Effects
         {
             provider.RunRectangleConstrainedValidatingProcessorTest(
                 (c, rect) => c.ApplyPixelShaderProcessor(
-                    (span, y, x) =>
+                    (span, offset) =>
                     {
+                        int y = offset.Y;
+                        int x = offset.X;
                         for (int i = 0; i < span.Length; i++)
                         {
                             float
@@ -95,7 +99,7 @@ namespace SixLabors.ImageSharp.Tests.Processing.Processors.Effects
                                 cosine = MathF.Cos(x + i),
                                 sum = sine + cosine,
                                 abs = MathF.Abs(sum),
-                                a = 0.5f + abs / 2;
+                                a = 0.5f + (abs / 2);
 
                             Vector4 v4 = span[i];
                             float avg = (v4.X + v4.Y + v4.Z) / 3f;