Better tests

Author: JimBobSquarePants

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

@@ -2,6 +2,7 @@
 // Licensed under the Apache License, Version 2.0.
 
 using System;
+using System.Numerics;
 using SixLabors.ImageSharp.Drawing.Processing;
 using SixLabors.ImageSharp.PixelFormats;
 using SixLabors.ImageSharp.Processing;
@@ -13,18 +14,26 @@ namespace SixLabors.ImageSharp.Drawing.Tests.Drawing
     public class ClipTests
     {
         [Theory]
-        [WithBasicTestPatternImages(250, 350, PixelTypes.Rgba32)]
-        public void Clip<TPixel>(TestImageProvider<TPixel> provider)
+        [WithBasicTestPatternImages(250, 350, PixelTypes.Rgba32, 0, 0)]
+        [WithBasicTestPatternImages(250, 350, PixelTypes.Rgba32, -20, -20)]
+        [WithBasicTestPatternImages(250, 350, PixelTypes.Rgba32, 20, 20)]
+        public void Clip<TPixel>(TestImageProvider<TPixel> provider, float dx, float dy)
             where TPixel : unmanaged, IPixel<TPixel>
-            => provider.RunValidatingProcessorTest(
-            x =>
-            {
-                Size size = x.GetCurrentSize();
-                int outerRadii = Math.Min(size.Width, size.Height) / 2;
-                var star = new Star(new PointF(size.Width / 2, size.Height / 2), 5, outerRadii / 2, outerRadii);
-                x.Clip(star, x => x.DetectEdges());
-            },
-            appendPixelTypeToFileName: false,
-            appendSourceFileOrDescription: false);
+        {
+            FormattableString testDetails = $"offset_x{dx}_y{dy}";
+            provider.RunValidatingProcessorTest(
+                x =>
+                {
+                    Size size = x.GetCurrentSize();
+                    int outerRadii = Math.Min(size.Width, size.Height) / 2;
+                    var star = new Star(new PointF(size.Width / 2, size.Height / 2), 5, outerRadii / 2, outerRadii);
+
+                    var builder = Matrix3x2.CreateTranslation(new Vector2(dx, dy));
+                    x.Clip(star.Transform(builder), x => x.DetectEdges());
+                },
+                testOutputDetails: testDetails,
+                appendPixelTypeToFileName: false,
+                appendSourceFileOrDescription: false);
+        }
     }
 }