Fix color and pixel operations. Touches #967 #1002

src/ImageSharp.Drawing/Processing/GradientBrush.cs

@@ -1,4 +1,4 @@
-// Copyright (c) Six Labors and contributors.
+// Copyright (c) Six Labors and contributors.
 // Licensed under the Apache License, Version 2.0.
 
 using System;
@@ -92,10 +92,10 @@ namespace SixLabors.ImageSharp.Processing
                             // onLocalGradient = Math.Min(0, Math.Max(1, onLocalGradient));
                             break;
                         case GradientRepetitionMode.Repeat:
-                            positionOnCompleteGradient = positionOnCompleteGradient % 1;
+                            positionOnCompleteGradient %= 1;
                             break;
                         case GradientRepetitionMode.Reflect:
-                            positionOnCompleteGradient = positionOnCompleteGradient % 2;
+                            positionOnCompleteGradient %= 2;
                             if (positionOnCompleteGradient > 1)
                             {
                                 positionOnCompleteGradient = 2 - positionOnCompleteGradient;
@@ -121,19 +121,12 @@ namespace SixLabors.ImageSharp.Processing
                     }
                     else
                     {
-                        var fromAsVector = from.Color.ToVector4();
-                        var toAsVector = to.Color.ToVector4();
                         float onLocalGradient = (positionOnCompleteGradient - from.Ratio) / (to.Ratio - from.Ratio);
 
                         // TODO: this should be changeble for different gradienting functions
-                        Vector4 result = PorterDuffFunctions.NormalSrcOver(
-                            fromAsVector,
-                            toAsVector,
-                            onLocalGradient);
-
-                        TPixel resultColor = default;
-                        resultColor.FromVector4(result);
-                        return resultColor;
+                        return PixelOperations<TPixel>
+                            .Instance.GetPixelBlender(PixelColorBlendingMode.Normal, PixelAlphaCompositionMode.SrcOver)
+                            .Blend(from.Color.ToPixel<TPixel>(), to.Color.ToPixel<TPixel>(), onLocalGradient);
                     }
                 }
             }
@@ -176,4 +169,4 @@ namespace SixLabors.ImageSharp.Processing
             }
         }
     }
-}
+}

src/ImageSharp.Drawing/Processing/ImageBrush.cs

@@ -1,4 +1,4 @@
-// Copyright (c) Six Labors and contributors.
+// Copyright (c) Six Labors and contributors.
 // Licensed under the Apache License, Version 2.0.
 
 using System;
@@ -167,4 +167,4 @@ namespace SixLabors.ImageSharp.Processing
             }
         }
     }
-}
+}

src/ImageSharp.Drawing/Processing/PathGradientBrush.cs

@@ -105,7 +105,7 @@ namespace SixLabors.ImageSharp.Processing
                     "One or more color is needed to construct a path gradient brush.");
             }
 
-            return new Color(colors.Select(c => c.ToVector4()).Aggregate((p1, p2) => p1 + p2) / colors.Length);
+            return new Color(colors.Select(c => (Vector4)c).Aggregate((p1, p2) => p1 + p2) / colors.Length);
         }
 
         private static float DistanceBetween(PointF p1, PointF p2) => ((Vector2)(p2 - p1)).Length();
@@ -141,10 +141,10 @@ namespace SixLabors.ImageSharp.Processing
                 Vector2[] points = path.LineSegments.SelectMany(s => s.Flatten()).Select(p => (Vector2)p).ToArray();
 
                 this.Start = points.First();
-                this.StartColor = startColor.ToVector4();
+                this.StartColor = (Vector4)startColor;
 
                 this.End = points.Last();
-                this.EndColor = endColor.ToVector4();
+                this.EndColor = (Vector4)endColor;
 
                 this.length = DistanceBetween(this.End, this.Start);
                 this.buffer = new PointF[this.path.MaxIntersections];
@@ -215,7 +215,7 @@ namespace SixLabors.ImageSharp.Processing
                 PointF[] points = edges.Select(s => s.Start).ToArray();
 
                 this.center = points.Aggregate((p1, p2) => p1 + p2) / edges.Count;
-                this.centerColor = centerColor.ToVector4();
+                this.centerColor = (Vector4)centerColor;
 
                 this.maxDistance = points.Select(p => (Vector2)(p - this.center)).Select(d => d.Length()).Max();
             }

src/ImageSharp.Drawing/Processing/PatternBrush.cs

@@ -1,4 +1,4 @@
-// Copyright (c) Six Labors and contributors.
+// Copyright (c) Six Labors and contributors.
 // Licensed under the Apache License, Version 2.0.
 
 using System;
@@ -61,8 +61,8 @@ namespace SixLabors.ImageSharp.Processing
         /// <param name="pattern">The pattern.</param>
         internal PatternBrush(Color foreColor, Color backColor, in DenseMatrix<bool> pattern)
         {
-            var foreColorVector = foreColor.ToVector4();
-            var backColorVector = backColor.ToVector4();
+            var foreColorVector = (Vector4)foreColor;
+            var backColorVector = (Vector4)backColor;
             this.pattern = new DenseMatrix<Color>(pattern.Columns, pattern.Rows);
             this.patternVector = new DenseMatrix<Vector4>(pattern.Columns, pattern.Rows);
             for (int i = 0; i < pattern.Data.Length; i++)
@@ -181,4 +181,4 @@ namespace SixLabors.ImageSharp.Processing
             }
         }
     }
-}
+}

src/ImageSharp/ImageSharp.csproj

@@ -1,4 +1,4 @@
-<?xml version="1.0" encoding="utf-8"?>
+<?xml version="1.0" encoding="utf-8"?>
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
@@ -119,7 +119,7 @@
   </ItemGroup>
 
   <ItemGroup>
-    <InternalsVisibleTo Include="SixLabors.ImageSharp.Drawing" />
+    <!--<InternalsVisibleTo Include="SixLabors.ImageSharp.Drawing" />-->
   </ItemGroup>
 
   <ItemGroup>