refactor SixLabors.ImageSharp.Primitives.Region

src/ImageSharp.Drawing/Primitives/Region.cs

@@ -1,6 +1,7 @@
 // Copyright (c) Six Labors and contributors.
 // Licensed under the Apache License, Version 2.0.
 
+using System;
 using SixLabors.Primitives;
 
 namespace SixLabors.ImageSharp.Primitives
@@ -19,7 +20,7 @@ namespace SixLabors.ImageSharp.Primitives
         /// Gets the bounding box that entirely surrounds this region.
         /// </summary>
         /// <remarks>
-        /// This should always contains all possible points returned from <see cref="Scan(float, float[], int)"/>.
+        /// This should always contains all possible points returned from <see cref="Scan"/>.
         /// </remarks>
         public abstract Rectangle Bounds { get; }
 
@@ -28,8 +29,8 @@ namespace SixLabors.ImageSharp.Primitives
         /// </summary>
         /// <param name="y">The position along the y axis to find intersections.</param>
         /// <param name="buffer">The buffer.</param>
-        /// <param name="offset">The point in the buffer to start setting offset.</param>
+        /// <param name="configuration">A <see cref="Configuration"/> instance in the context of the caller.</param>
         /// <returns>The number of intersections found.</returns>
-        public abstract int Scan(float y, float[] buffer, int offset);
+        public abstract int Scan(float y, Span<float> buffer, Configuration configuration);
     }
 }

src/ImageSharp.Drawing/Primitives/ShapeRegion.cs

@@ -2,6 +2,7 @@
 // Licensed under the Apache License, Version 2.0.
 
 using System;
+using SixLabors.ImageSharp.Memory;
 using SixLabors.Primitives;
 using SixLabors.Shapes;
 
@@ -39,21 +40,23 @@ namespace SixLabors.ImageSharp.Primitives
         public override Rectangle Bounds { get; }
 
         /// <inheritdoc/>
-        public override int Scan(float y, float[] buffer, int offset)
+        public override int Scan(float y, Span<float> buffer, Configuration configuration)
         {
             var start = new PointF(this.Bounds.Left - 1, y);
             var end = new PointF(this.Bounds.Right + 1, y);
 
-            // TODO: This is a temporary workaround because of the lack of Span<T> API-s on IPath. We should use MemoryManager.Allocate() here!
-            var innerBuffer = new PointF[buffer.Length];
-            int count = this.Shape.FindIntersections(start, end, innerBuffer, 0);
-
-            for (int i = 0; i < count; i++)
+            using (IBuffer<PointF> tempBuffer = configuration.MemoryManager.Allocate<PointF>(buffer.Length))
             {
-                buffer[i + offset] = innerBuffer[i].X;
-            }
+                Span<PointF> innerBuffer = tempBuffer.GetSpan();
+                int count = this.Shape.FindIntersections(start, end, innerBuffer);
 
-            return count;
+                for (int i = 0; i < count; i++)
+                {
+                    buffer[i] = innerBuffer[i].X;
+                }
+
+                return count;
+            }
         }
     }
 }

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

@@ -118,7 +118,7 @@ namespace SixLabors.ImageSharp.Processing.Drawing.Processors
                         float yPlusOne = y + 1;
                         for (float subPixel = (float)y; subPixel < yPlusOne; subPixel += subpixelFraction)
                         {
-                            int pointsFound = region.Scan(subPixel + offset, buffer.Array, 0);
+                            int pointsFound = region.Scan(subPixel + offset, buffer.GetSpan(), configuration);
                             if (pointsFound == 0)
                             {
                                 // nothing on this line skip

tests/ImageSharp.Tests/Drawing/FillRegionProcessorTests.cs

@@ -4,7 +4,8 @@
 using System.Numerics;
 
 using Moq;
-
+using System;
+using SixLabors.ImageSharp.Memory;
 using SixLabors.ImageSharp.PixelFormats;
 using SixLabors.ImageSharp.Primitives;
 using SixLabors.ImageSharp.Processing;
@@ -13,13 +14,15 @@ using SixLabors.ImageSharp.Processing.Drawing.Brushes;
 using SixLabors.ImageSharp.Processing.Drawing.Pens;
 using SixLabors.ImageSharp.Processing.Drawing.Processors;
 using SixLabors.Primitives;
-
 using Xunit;
 
 namespace SixLabors.ImageSharp.Tests.Drawing
 {
+    
+
     public class FillRegionProcessorTests
     {
+        
         [Theory]
         [InlineData(true, 1, 4)]
         [InlineData(true, 2, 4)]
@@ -29,21 +32,20 @@ namespace SixLabors.ImageSharp.Tests.Drawing
         [InlineData(false, 16, 4)] // we always do 4 sub=pixels when antialising is off.
         public void MinimumAntialiasSubpixelDepth(bool antialias, int antialiasSubpixelDepth, int expectedAntialiasSubpixelDepth)
         {
-            var bounds = new SixLabors.Primitives.Rectangle(0, 0, 1, 1);
+            var bounds = new Rectangle(0, 0, 1, 1);
 
             var brush = new Mock<IBrush<Rgba32>>();
-            var region = new Mock<Region>();
-            region.Setup(x => x.Bounds).Returns(bounds);
+            var region = new MockRegion2(bounds);
 
             var options = new GraphicsOptions(antialias)
             {
                 AntialiasSubpixelDepth = 1
             };
-            var processor = new FillRegionProcessor<Rgba32>(brush.Object, region.Object, options);
+            var processor = new FillRegionProcessor<Rgba32>(brush.Object, region, options);
             var img = new Image<Rgba32>(1, 1);
             processor.Apply(img, bounds);
 
-            region.Verify(x => x.Scan(It.IsAny<float>(), It.IsAny<float[]>(), It.IsAny<int>()), Times.Exactly(4));
+            Assert.Equal(4, region.ScanInvocationCounter);
         }
 
         [Fact]
@@ -52,7 +54,7 @@ namespace SixLabors.ImageSharp.Tests.Drawing
             var bounds = new Rectangle(-100, -10, 10, 10);
             var brush = new Mock<IBrush<Rgba32>>();
             var options = new GraphicsOptions(true);
-            var processor = new FillRegionProcessor<Rgba32>(brush.Object, new MockRegion(), options);
+            var processor = new FillRegionProcessor<Rgba32>(brush.Object, new MockRegion1(), options);
             var img = new Image<Rgba32>(10, 10);
             processor.Apply(img, bounds);
         }
@@ -71,13 +73,11 @@ namespace SixLabors.ImageSharp.Tests.Drawing
         }
 
         // Mocking the region throws an error in netcore2.0
-        private class MockRegion : Region
+        private class MockRegion1 : Region
         {
             public override Rectangle Bounds => new Rectangle(-100, -10, 10, 10);
 
-            public override int MaxIntersections => 10;
-
-            public override int Scan(float y, float[] buffer, int offset)
+            public override int Scan(float y, Span<float> buffer, Configuration configuration)
             {
                 if (y < 5)
                 {
@@ -87,6 +87,28 @@ namespace SixLabors.ImageSharp.Tests.Drawing
                 }
                 return 0;
             }
+
+            public override int MaxIntersections => 10;
+        }
+
+        private class MockRegion2 : Region
+        {
+            public MockRegion2(Rectangle bounds)
+            {
+                this.Bounds = bounds;
+            }
+
+            public override int MaxIntersections => 100;
+
+            public override Rectangle Bounds { get; }
+
+            public int ScanInvocationCounter { get; private set; }
+
+            public override int Scan(float y, Span<float> buffer, Configuration configuration)
+            {
+                this.ScanInvocationCounter++;
+                return 0;
+            }
         }
     }
 }

tests/ImageSharp.Tests/Drawing/Paths/ShapeRegionTests.cs

@@ -86,7 +86,7 @@ namespace SixLabors.ImageSharp.Tests.Drawing.Paths
                             Assert.True(e.X > this.bounds.Right);
                         }).Returns(0);
 
-            int i = region.Scan(yToScan, new float[0], 0);
+            int i = region.Scan(yToScan, new float[0], Configuration.Default);
 
             this.pathMock.Verify(
                 x => x.FindIntersections(It.IsAny<PointF>(), It.IsAny<PointF>(), It.IsAny<PointF[]>(), It.IsAny<int>()),
@@ -114,7 +114,7 @@ namespace SixLabors.ImageSharp.Tests.Drawing.Paths
                             Assert.True(e.X > this.bounds.Right);
                         }).Returns(0);
 
-            int i = region.Scan(yToScan, new float[0], 0);
+            int i = region.Scan(yToScan, new float[0], Configuration.Default);
 
             this.pathMock.Verify(
                 x => x.FindIntersections(It.IsAny<PointF>(), It.IsAny<PointF>(), It.IsAny<PointF[]>(), It.IsAny<int>()),