better FillSolidBrushTests + bugfix in FillProcessor

src/ImageSharp.Drawing/Processing/Drawing/Processors/FillProcessor.cs

@@ -68,7 +68,7 @@ protected override void OnFrameApply(ImageFrame<TPixel> source, Rectangle source
                 sourceRectangle,
                 this.options))
             {
-                amount.Span.Fill(this.options.BlendPercentage);
+                amount.Span.Fill(1f);
 
                 Parallel.For(
                     minY,

tests/ImageSharp.Tests/Drawing/FillSolidBrushTests.cs

@@ -1,79 +1,164 @@
 // Copyright (c) Six Labors and contributors.
 // Licensed under the Apache License, Version 2.0.
 
-using System.Numerics;
 using SixLabors.ImageSharp.PixelFormats;
 using SixLabors.ImageSharp.Processing;
 using SixLabors.ImageSharp.Processing.Drawing;
-using SixLabors.ImageSharp.Processing.Overlays;
+using SixLabors.ImageSharp.Primitives;
+using SixLabors.ImageSharp.Processing.Drawing.Brushes;
+using SixLabors.Shapes;
 using Xunit;
+// ReSharper disable InconsistentNaming
 
 namespace SixLabors.ImageSharp.Tests.Drawing
 {
-    public class FillSolidBrushTests : FileTestBase
+
+
+    [GroupOutput("Drawing")]
+    public class FillSolidBrushTests
     {
-        [Fact]
-        public void ImageShouldBeFloodFilledWithColorOnDefaultBackground()
+        [Theory]
+        [WithBlankImages(1, 1, PixelTypes.Rgba32)]
+        [WithBlankImages(7, 4, PixelTypes.Rgba32)]
+        [WithBlankImages(16, 7, PixelTypes.Rgba32)]
+        [WithBlankImages(33, 32, PixelTypes.Rgba32)]
+        [WithBlankImages(400, 500, PixelTypes.Rgba32)]
+        public void DoesNotDependOnSize<TPixel>(TestImageProvider<TPixel> provider)
+            where TPixel : struct, IPixel<TPixel>
         {
-            string path = TestEnvironment.CreateOutputDirectory("Fill", "SolidBrush");
-            using (var image = new Image<Rgba32>(500, 500))
+            using (Image<TPixel> image = provider.GetImage())
             {
-                image.Mutate(x => x.Fill(Rgba32.HotPink));
-                image.Save($"{path}/DefaultBack.png");
-
-                using (PixelAccessor<Rgba32> sourcePixels = image.Lock())
-                {
-                    Assert.Equal(Rgba32.HotPink, sourcePixels[9, 9]);
+                TPixel color = NamedColors<TPixel>.HotPink;
+                image.Mutate(c => c.Fill(color));
 
-                    Assert.Equal(Rgba32.HotPink, sourcePixels[199, 149]);
-                }
+                image.DebugSave(provider, appendPixelTypeToFileName: false);
+                image.ComparePixelBufferTo(color);
             }
         }
 
-        [Fact]
-        public void ImageShouldBeFloodFilledWithColor()
+        [Theory]
+        [WithBlankImages(16, 16, PixelTypes.Rgba32 | PixelTypes.Argb32 | PixelTypes.RgbaVector)]
+        public void DoesNotDependOnSinglePixelType<TPixel>(TestImageProvider<TPixel> provider)
+            where TPixel : struct, IPixel<TPixel>
         {
-            string path = TestEnvironment.CreateOutputDirectory("Fill", "SolidBrush");
-            using (var image = new Image<Rgba32>(500, 500))
+            using (Image<TPixel> image = provider.GetImage())
             {
-                image.Mutate(x => x
-                    .BackgroundColor(Rgba32.Blue)
-                    .Fill(Rgba32.HotPink));
-                image.Save($"{path}/Simple.png");
+                TPixel color = NamedColors<TPixel>.HotPink;
+                image.Mutate(c => c.Fill(color));
 
-                using (PixelAccessor<Rgba32> sourcePixels = image.Lock())
-                {
-                    Assert.Equal(Rgba32.HotPink, sourcePixels[9, 9]);
-
-                    Assert.Equal(Rgba32.HotPink, sourcePixels[199, 149]);
-                }
+                image.DebugSave(provider, appendSourceFileOrDescription: false);
+                image.ComparePixelBufferTo(color);
             }
         }
 
-        [Fact]
-        public void ImageShouldBeFloodFilledWithColorOpacity()
+        [Theory]
+        [WithSolidFilledImages(16, 16, "Red", PixelTypes.Rgba32, "Blue")]
+        [WithSolidFilledImages(16, 16, "Yellow", PixelTypes.Rgba32, "Khaki")]
+        public void WhenColorIsOpaque_OverridePreviousColor<TPixel>(TestImageProvider<TPixel> provider, string newColorName)
+            where TPixel : struct, IPixel<TPixel>
         {
-            string path = TestEnvironment.CreateOutputDirectory("Fill", "SolidBrush");
-            using (var image = new Image<Rgba32>(500, 500))
+            using (Image<TPixel> image = provider.GetImage())
             {
-                var color = new Rgba32(Rgba32.HotPink.R, Rgba32.HotPink.G, Rgba32.HotPink.B, 150);
+                TPixel color = TestUtils.GetPixelOfNamedColor<TPixel>(newColorName);
+                image.Mutate(c => c.Fill(color));
+
+                image.DebugSave(provider, newColorName, appendPixelTypeToFileName: false, appendSourceFileOrDescription: false);
+                image.ComparePixelBufferTo(color);
+            }
+        }
+
+        public static readonly TheoryData<bool, string, float, PixelBlenderMode, float> BlendData =
+            new TheoryData<bool, string, float, PixelBlenderMode, float>()
+                {
+                    { false, "Blue", 0.5f, PixelBlenderMode.Normal, 1.0f },
+                    { false, "Blue", 1.0f, PixelBlenderMode.Normal, 0.5f },
+                    { false, "Green", 0.5f, PixelBlenderMode.Normal, 0.3f },
+                    { false, "HotPink", 0.8f, PixelBlenderMode.Normal, 0.8f },
+
+                    { false, "Blue", 0.5f, PixelBlenderMode.Multiply, 1.0f },
+                    { false, "Blue", 1.0f, PixelBlenderMode.Multiply, 0.5f },
+                    { false, "Green", 0.5f, PixelBlenderMode.Multiply, 0.3f },
+                    { false, "HotPink", 0.8f, PixelBlenderMode.Multiply, 0.8f },
+
+                    { false, "Blue", 0.5f, PixelBlenderMode.Add, 1.0f },
+                    { false, "Blue", 1.0f, PixelBlenderMode.Add, 0.5f },
+                    { false, "Green", 0.5f, PixelBlenderMode.Add, 0.3f },
+                    { false, "HotPink", 0.8f, PixelBlenderMode.Add, 0.8f },
 
-                image.Mutate(x => x
-                    .BackgroundColor(Rgba32.Blue)
-                    .Fill(color));
-                image.Save($"{path}/Opacity.png");
+                    { true, "Blue", 0.5f, PixelBlenderMode.Normal, 1.0f },
+                    { true, "Blue", 1.0f, PixelBlenderMode.Normal, 0.5f },
+                    { true, "Green", 0.5f, PixelBlenderMode.Normal, 0.3f },
+                    { true, "HotPink", 0.8f, PixelBlenderMode.Normal, 0.8f },
 
-                //shift background color towards forground color by the opacity amount
-                var mergedColor = new Rgba32(Vector4.Lerp(Rgba32.Blue.ToVector4(), Rgba32.HotPink.ToVector4(), 150f / 255f));
+                    { true, "Blue", 0.5f, PixelBlenderMode.Multiply, 1.0f },
+                    { true, "Blue", 1.0f, PixelBlenderMode.Multiply, 0.5f },
+                    { true, "Green", 0.5f, PixelBlenderMode.Multiply, 0.3f },
+                    { true, "HotPink", 0.8f, PixelBlenderMode.Multiply, 0.8f },
 
+                    { true, "Blue", 0.5f, PixelBlenderMode.Add, 1.0f },
+                    { true, "Blue", 1.0f, PixelBlenderMode.Add, 0.5f },
+                    { true, "Green", 0.5f, PixelBlenderMode.Add, 0.3f },
+                    { true, "HotPink", 0.8f, PixelBlenderMode.Add, 0.8f },
+                };
 
-                using (PixelAccessor<Rgba32> sourcePixels = image.Lock())
+        [Theory]
+        [WithSolidFilledImages(nameof(BlendData), 16, 16, "Red", PixelTypes.Rgba32)]
+        public void BlendFillColorOverBackround<TPixel>(
+            TestImageProvider<TPixel> provider,
+            bool triggerFillRegion,
+            string newColorName,
+            float alpha,
+            PixelBlenderMode blenderMode,
+            float blendPercentage)
+            where TPixel : struct, IPixel<TPixel>
+        {
+            var vec = TestUtils.GetPixelOfNamedColor<RgbaVector>(newColorName).ToVector4();
+            vec.W = alpha;
+
+            TPixel fillColor = default;
+            fillColor.PackFromVector4(vec);
+
+            using (Image<TPixel> image = provider.GetImage())
+            {
+                TPixel bgColor = image[0, 0];
+
+                var options = new GraphicsOptions(false)
+                                  {
+                                      BlenderMode = blenderMode,
+                                      BlendPercentage = blendPercentage
+                                  };
+
+                if (triggerFillRegion)
+                {
+                    var region = new ShapeRegion(new RectangularPolygon(0, 0, 16, 16));
+
+                    image.Mutate(c => c.Fill(options, new SolidBrush<TPixel>(fillColor), region));
+                }
+                else
                 {
-                    Assert.Equal(mergedColor, sourcePixels[9, 9]);
-                    Assert.Equal(mergedColor, sourcePixels[199, 149]);
+                    image.Mutate(c => c.Fill(options, new SolidBrush<TPixel>(fillColor)));
                 }
+
+                var testOutputDetails = new
+                                            {
+                                                triggerFillRegion = triggerFillRegion,
+                                                newColorName = newColorName,
+                                                alpha = alpha,
+                                                blenderMode = blenderMode,
+                                                blendPercentage = blendPercentage
+                                            };
+
+                image.DebugSave(
+                    provider,
+                    testOutputDetails,
+                    appendPixelTypeToFileName: false,
+                    appendSourceFileOrDescription: false);
+
+                PixelBlender<TPixel> blender = PixelOperations<TPixel>.Instance.GetPixelBlender(blenderMode);
+                TPixel expectedPixel = blender.Blend(bgColor, fillColor, blendPercentage);
+
+                image.ComparePixelBufferTo(expectedPixel);
             }
         }
-
     }
 }

tests/ImageSharp.Tests/TestUtilities/Attributes/WithSolidFilledImagesAttribute.cs

@@ -133,7 +133,7 @@ public WithSolidFilledImagesAttribute(
         {
             Guard.NotNull(colorName, nameof(colorName));
 
-            var c = (Rgba32)typeof(Rgba32).GetTypeInfo().GetField(colorName).GetValue(null);
+            Rgba32 c = TestUtils.GetPixelOfNamedColor<Rgba32>(colorName);
             this.R = c.R;
             this.G = c.G;
             this.B = c.B;

tests/ImageSharp.Tests/TestUtilities/TestImageExtensions.cs

@@ -346,13 +346,26 @@ public static Image<TPixel> ComparePixelBufferTo<TPixel>(
             Span<TPixel> expectedPixels)
             where TPixel : struct, IPixel<TPixel>
         {
-            Span<TPixel> actual = image.GetPixelSpan();
+            Span<TPixel> actualPixels = image.GetPixelSpan();
 
-            Assert.True(expectedPixels.Length == actual.Length, "Buffer sizes are not equal!");
+            Assert.True(expectedPixels.Length == actualPixels.Length, "Buffer sizes are not equal!");
 
             for (int i = 0; i < expectedPixels.Length; i++)
             {
-                Assert.True(expectedPixels[i].Equals(actual[i]), $"Pixels are different on position {i}!");
+                Assert.True(expectedPixels[i].Equals(actualPixels[i]), $"Pixels are different on position {i}!");
+            }
+
+            return image;
+        }
+
+        public static Image<TPixel> ComparePixelBufferTo<TPixel>(this Image<TPixel> image, TPixel expectedPixel)
+            where TPixel : struct, IPixel<TPixel>
+        {
+            Span<TPixel> actualPixels = image.GetPixelSpan();
+
+            for (int i = 0; i < actualPixels.Length; i++)
+            {
+                Assert.True(expectedPixel.Equals(actualPixels[i]), $"Pixels are different on position {i}!");
             }
 
             return image;

tests/ImageSharp.Tests/TestUtilities/TestUtils.cs

@@ -147,6 +147,11 @@ internal static bool HasAll(this PixelTypes pixelTypes, PixelTypes flagsToCheck)
         /// <returns>The pixel types</returns>
         internal static PixelTypes[] GetAllPixelTypes() => (PixelTypes[])Enum.GetValues(typeof(PixelTypes));
 
+        internal static TPixel GetPixelOfNamedColor<TPixel>(string colorName)
+            where TPixel : struct, IPixel<TPixel>
+        {
+            return (TPixel)typeof(NamedColors<TPixel>).GetTypeInfo().GetField(colorName).GetValue(null);
+        }
 
         /// <summary>
         /// Utility for testing image processor extension methods: