offset per path causing drift

SixLabors · Sep 12, 2017 · 27f4867 · 27f4867
1 parent a8ad968
commit 27f4867
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Showing 4 changed files with 349 additions and 3 deletions.
diff --git a/icons/shapes-logo.svg b/icons/shapes-logo.svg
diff --git a/src/SixLabors.Shapes/ComplexPolygon.cs b/src/SixLabors.Shapes/ComplexPolygon.cs
@@ -173,8 +173,7 @@ public int FindIntersections(PointF start, PointF end, PointF[] buffer, int offs
             int totalAdded = 0;
             for (int i = 0; i < this.paths.Length; i++)
             {
-                offset += totalAdded;
-                int added = this.paths[i].FindIntersections(start, end, buffer, offset);
+                int added = this.paths[i].FindIntersections(start, end, buffer, totalAdded + offset);
                 totalAdded += added;
             }
 

diff --git a/src/SixLabors.Shapes/Outliner.cs b/src/SixLabors.Shapes/Outliner.cs
@@ -148,7 +148,7 @@ public static IPath GenerateOutline(this IPath path, float width)
                 EndType type = p.IsClosed ? EndType.etClosedLine : EndType.etOpenButt;
 
 
-                offset.AddPath(points, JoinType.jtMiter, type);
+                offset.AddPath(points, JoinType.jtSquare, type);
             }
 
             return ExecuteOutliner(width, offset);

diff --git a/tests/SixLabors.Shapes.Tests/Issues/Issue_ClippedPaths.cs b/tests/SixLabors.Shapes.Tests/Issues/Issue_ClippedPaths.cs
@@ -0,0 +1,30 @@
+using SixLabors.Primitives;
+using System;
+using System.Collections.Generic;
+using System.Text;
+using Xunit;
+
+namespace SixLabors.Shapes.Tests.Issues
+{
+    public class Issue_ClippedPaths
+    {
+        [Fact]
+        public void ClippedTriangle()
+        {
+            Polygon simplePath = new Polygon(new LinearLineSegment(
+                           new PointF(10, 10),
+                           new PointF(200, 150),
+                           new PointF(50, 300)));
+
+            Polygon hole1 = new Polygon(new LinearLineSegment(
+                            new PointF(37, 85),
+                            new PointF(93, 85),
+                            new PointF(65, 137)));
+
+            var clippedPath = simplePath.Clip(hole1);
+            var outline = clippedPath.GenerateOutline(5, new[] { 1f });
+
+            Assert.False(outline.Contains(new PointF(74, 97)));
+        }
+    }
+}