More tests and NET 472 hacks

Author: JimBobSquarePants

src/ImageSharp.Drawing/Shapes/PolygonClipper/Clipper.cs

@@ -46,7 +46,12 @@ public IPath[] GenerateClippedShapes(ClippingOperation operation, IntersectionRu
 
                 for (int j = 0; j < path.Count; j++)
                 {
+#if NET472
+                    Vector2 v = path[j];
+                    points[j] = new PointF((float)(v.X / (double)ScalingFactor), (float)(v.Y / (double)ScalingFactor));
+#else
                     points[j] = path[j] / ScalingFactor;
+#endif
                 }
 
                 shapes[index++] = new Polygon(new LinearLineSegment(points));
@@ -59,7 +64,12 @@ public IPath[] GenerateClippedShapes(ClippingOperation operation, IntersectionRu
 
                 for (int j = 0; j < path.Count; j++)
                 {
+#if NET472
+                    Vector2 v = path[j];
+                    points[j] = new PointF((float)(v.X / (double)ScalingFactor), (float)(v.Y / (double)ScalingFactor));
+#else
                     points[j] = path[j] / ScalingFactor;
+#endif
                 }
 
                 shapes[index++] = new Polygon(new LinearLineSegment(points));

src/ImageSharp.Drawing/Shapes/PolygonClipper/ClipperOffset.cs

@@ -40,7 +40,12 @@ public ComplexPolygon Execute(float width)
                 var points = new PointF[pt.Count];
                 for (int j = 0; j < pt.Count; j++)
                 {
+#if NET472
+                    Vector2 v = pt[j];
+                    points[j] = new PointF((float)(v.X / (double)ScalingFactor), (float)(v.Y / (double)ScalingFactor));
+#else
                     points[j] = pt[j] / ScalingFactor;
+#endif
                 }
 
                 polygons[i] = new Polygon(new LinearLineSegment(points));

tests/ImageSharp.Drawing.Tests/Drawing/ClipTests.cs

@@ -2,6 +2,8 @@
 // Licensed under the Apache License, Version 2.0.
 
 using System;
+using System.Collections.Generic;
+using System.Linq;
 using System.Numerics;
 using SixLabors.ImageSharp.Drawing.Processing;
 using SixLabors.ImageSharp.PixelFormats;
@@ -36,5 +38,22 @@ public void Clip<TPixel>(TestImageProvider<TPixel> provider, float dx, float dy,
                 appendPixelTypeToFileName: false,
                 appendSourceFileOrDescription: false);
         }
+
+        [Fact]
+        public void Issue250_Vertical_Horizontal_Count_Should_Match()
+        {
+            var clip = new PathCollection(new RectangularPolygon(new PointF(24, 16), new PointF(777, 385)));
+
+            var vert = new Path(new LinearLineSegment(new PointF(26, 384), new PointF(26, 163)));
+            var horiz = new Path(new LinearLineSegment(new PointF(26, 163), new PointF(176, 163)));
+
+            IPath reverse = vert.Clip(clip);
+            IEnumerable<ReadOnlyMemory<PointF>> result1 = vert.Clip(reverse).Flatten().Select(x => x.Points);
+
+            reverse = horiz.Clip(clip);
+            IEnumerable<ReadOnlyMemory<PointF>> result2 = horiz.Clip(reverse).Flatten().Select(x => x.Points);
+
+            bool same = result1.Count() == result2.Count();
+        }
     }
 }

tests/ImageSharp.Drawing.Tests/Drawing/FillPolygonTests.cs

@@ -192,6 +192,7 @@ public void FillPolygon_StarCircle_AllOperations(TestImageProvider<Rgba32> provi
             IPath circle = new EllipsePolygon(36, 36, 36).Translate(28, 28);
             var star = new Star(64, 64, 5, 24, 64);
 
+            // See http://www.angusj.com/clipper2/Docs/Units/Clipper/Types/ClipType.htm for reference.
             foreach (ClippingOperation operation in (ClippingOperation[])Enum.GetValues(typeof(ClippingOperation)))
             {
                 IPath shape = star.Clip(operation, IntersectionRule.EvenOdd, circle);

tests/ImageSharp.Drawing.Tests/Drawing/Text/DrawTextOnImageTests.cs

@@ -704,7 +704,7 @@ public void CanDrawTextAlongPathHorizontal<TPixel>(TestImageProvider<TPixel> pro
             provider.RunValidatingProcessorTest(
                 c => c.Fill(Color.White).Draw(Color.Red, 1, path).Fill(Color.Black, glyphs),
                 new { type = exampleImageKey },
-                comparer: ImageComparer.TolerantPercentage(0.002f));
+                comparer: ImageComparer.TolerantPercentage(0.0025f));
         }
 
         [Theory]