Improve test coverage

- fixed bug in pattern brush and added test coverage
- change DebugGuard -> Guard
- Update SixLabors.Shapes to version not doing array allocation on hot path.

src/ImageSharp.Drawing/Brushes/ImageBrush{TColor}.cs

@@ -115,7 +115,7 @@ namespace ImageSharp.Drawing.Brushes
             /// <inheritdoc />
             internal override void Apply(float[] scanlineBuffer, int scanlineWidth, int offset, int x, int y)
             {
-                DebugGuard.MustBeGreaterThanOrEqualTo(scanlineBuffer.Length, offset + scanlineWidth, nameof(scanlineWidth));
+                Guard.MustBeGreaterThanOrEqualTo(scanlineBuffer.Length, offset + scanlineWidth, nameof(scanlineWidth));
 
                 using (PinnedBuffer<float> buffer = new PinnedBuffer<float>(scanlineBuffer))
                 {

src/ImageSharp.Drawing/Brushes/PatternBrush{TColor}.cs

@@ -86,6 +86,7 @@ namespace ImageSharp.Drawing.Brushes
         internal PatternBrush(PatternBrush<TColor> brush)
         {
             this.pattern = brush.pattern;
+            this.patternVector = brush.patternVector;
         }
 
         /// <inheritdoc />
@@ -112,7 +113,7 @@ namespace ImageSharp.Drawing.Brushes
             /// <param name="pattern">The pattern.</param>
             /// <param name="patternVector">The patternVector.</param>
             public PatternBrushApplicator(PixelAccessor<TColor> sourcePixels, Fast2DArray<TColor> pattern, Fast2DArray<Vector4> patternVector)
-            : base(sourcePixels)
+                : base(sourcePixels)
             {
                 this.pattern = pattern;
                 this.patternVector = patternVector;
@@ -147,7 +148,7 @@ namespace ImageSharp.Drawing.Brushes
             /// <inheritdoc />
             internal override void Apply(float[] scanlineBuffer, int scanlineWidth, int offset, int x, int y)
             {
-                DebugGuard.MustBeGreaterThanOrEqualTo(scanlineBuffer.Length, offset + scanlineWidth, nameof(scanlineWidth));
+                Guard.MustBeGreaterThanOrEqualTo(scanlineBuffer.Length, offset + scanlineWidth, nameof(scanlineWidth));
 
                 using (PinnedBuffer<float> buffer = new PinnedBuffer<float>(scanlineBuffer))
                 {
@@ -164,7 +165,7 @@ namespace ImageSharp.Drawing.Brushes
                             Vector4 backgroundVector = this.Target[targetX, targetY].ToVector4();
 
                             // 2d array index at row/column
-                            Vector4 sourceVector = this.patternVector[targetY % this.pattern.Height, targetX % this.pattern.Width];
+                            Vector4 sourceVector = this.patternVector[targetY % this.patternVector.Height, targetX % this.patternVector.Width];
 
                             Vector4 finalColor = Vector4BlendTransforms.PremultipliedLerp(backgroundVector, sourceVector, opacity);
 

src/ImageSharp.Drawing/Brushes/RecolorBrush{TColor}.cs

@@ -139,7 +139,7 @@ namespace ImageSharp.Drawing.Brushes
             /// <inheritdoc />
             internal override void Apply(float[] scanlineBuffer, int scanlineWidth, int offset, int x, int y)
             {
-                DebugGuard.MustBeGreaterThanOrEqualTo(scanlineBuffer.Length, offset + scanlineWidth, nameof(scanlineWidth));
+                Guard.MustBeGreaterThanOrEqualTo(scanlineBuffer.Length, offset + scanlineWidth, nameof(scanlineWidth));
 
                 using (PinnedBuffer<float> buffer = new PinnedBuffer<float>(scanlineBuffer))
                 {

src/ImageSharp.Drawing/Brushes/SolidBrush{TColor}.cs

@@ -87,7 +87,7 @@ namespace ImageSharp.Drawing.Brushes
             /// <inheritdoc />
             internal override void Apply(float[] scanlineBuffer, int scanlineWidth, int offset, int x, int y)
             {
-                DebugGuard.MustBeGreaterThanOrEqualTo(scanlineBuffer.Length, offset + scanlineWidth, nameof(scanlineWidth));
+                Guard.MustBeGreaterThanOrEqualTo(scanlineBuffer.Length, offset + scanlineWidth, nameof(scanlineWidth));
 
                 using (PinnedBuffer<float> buffer = new PinnedBuffer<float>(scanlineBuffer))
                 {

src/ImageSharp.Drawing/ImageSharp.Drawing.csproj

@@ -40,7 +40,7 @@
       <PrivateAssets>All</PrivateAssets>
     </PackageReference>
     <PackageReference Include="SixLabors.Fonts" Version="0.1.0-alpha0002" />
-    <PackageReference Include="SixLabors.Shapes" Version="0.1.0-alpha0008" />
+    <PackageReference Include="SixLabors.Shapes" Version="0.1.0-alpha0009" />
   </ItemGroup>
   <PropertyGroup>
     <CodeAnalysisRuleSet>..\..\ImageSharp.ruleset</CodeAnalysisRuleSet>

tests/ImageSharp.Benchmarks/Drawing/FillPolygon.cs

@@ -9,6 +9,7 @@ namespace ImageSharp.Benchmarks
     using System.Drawing.Drawing2D;
     using System.IO;
     using System.Numerics;
+    using SixLabors.Shapes;
 
     using BenchmarkDotNet.Attributes;
 
@@ -17,6 +18,15 @@ namespace ImageSharp.Benchmarks
 
     public class FillPolygon : BenchmarkBase
     {
+        private readonly Polygon shape;
+
+        public FillPolygon()
+        {
+            this.shape = new SixLabors.Shapes.Polygon(new LinearLineSegment(new Vector2(10, 10),
+                        new Vector2(550, 50),
+                        new Vector2(200, 400)));
+        }
+
         [Benchmark(Baseline = true, Description = "System.Drawing Fill Polygon")]
         public void DrawSolidPolygonSystemDrawing()
         {
@@ -60,5 +70,21 @@ namespace ImageSharp.Benchmarks
                 }
             }
         }
+
+        [Benchmark(Description = "ImageSharp Fill Polygon - cached shape")]
+        public void DrawSolidPolygonCoreCahced()
+        {
+            using (CoreImage image = new CoreImage(800, 800))
+            {
+                image.Fill(
+                    CoreColor.HotPink,
+                    this.shape);
+
+                using (MemoryStream ms = new MemoryStream())
+                {
+                    image.SaveAsBmp(ms);
+                }
+            }
+        }
     }
 }

tests/ImageSharp.Tests/Drawing/SolidPolygonTests.cs

@@ -43,6 +43,32 @@ namespace ImageSharp.Tests.Drawing
             }
         }
 
+        [Fact]
+        public void ImageShouldBeOverlayedByFilledPolygonWithPattern()
+        {
+            string path = this.CreateOutputDirectory("Drawing", "FilledPolygons");
+            Vector2[] simplePath = new[] {
+                            new Vector2(10, 10),
+                            new Vector2(200, 150),
+                            new Vector2(50, 300)
+            };
+
+            using (Image image = new Image(500, 500))
+            {
+                using (FileStream output = File.OpenWrite($"{path}/Pattern.png"))
+                {
+                    image
+                        .FillPolygon(Brushes.Horizontal(Color.HotPink), simplePath, new GraphicsOptions(true))
+                        .Save(output);
+                }
+
+                using (PixelAccessor<Color> sourcePixels = image.Lock())
+                {
+                    Assert.Equal(Color.HotPink, sourcePixels[81, 145]);
+                }
+            }
+        }
+
         [Fact]
         public void ImageShouldBeOverlayedByFilledPolygonNoAntialias()
         {