Simplify EdgeIterator implementation.

src/Triangle.Rendering/Text/EdgeIterator.cs

@@ -1,58 +0,0 @@
-
-namespace TriangleNet.Rendering.Text
-{
-    using System.Collections.Generic;
-    using TriangleNet.Geometry;
-
-    static class EdgeIterator
-    {
-        /// <summary>
-        /// Enumerate the edges of the mesh.
-        /// </summary>
-        /// <param name="mesh"></param>
-        /// <param name="skipSegments"></param>
-        /// <returns></returns>
-        /// <remarks>
-        /// In contrast to the <see cref="TriangleNet.Meshing.Iterators.EdgeIterator"/> this
-        /// method will return objects that include the vertex information (and not only the
-        /// indices).
-        /// </remarks>
-        public static  IEnumerable<ISegment> EnumerateEdges(Mesh mesh, bool skipSegments = true)
-        {
-            foreach (var t in mesh.Triangles)
-            {
-                for (int i = 0; i < 3; i++)
-                {
-                    int nid = t.GetNeighborID(i);
-
-                    if ((t.ID < nid) || (nid < 0))
-                    {
-                        var s = t.GetSegment(i);
-
-                        if (skipSegments && s == null)
-                        {
-                            // Since segments will be processed separately, don't
-                            // include them in the enumeration.
-                            yield return new Segment(
-                                t.GetVertex((i + 1) % 3),
-                                t.GetVertex((i + 2) % 3));
-                        }
-                        else
-                        {
-                            if (s == null)
-                            {
-                                yield return new Segment(
-                                    t.GetVertex((i + 1) % 3),
-                                    t.GetVertex((i + 2) % 3));
-                            }
-                            else
-                            {
-                                yield return s;
-                            }
-                        }
-                    }
-                }
-            }
-        }
-    }
-}

src/Triangle.Rendering/Text/EpsImage.cs

@@ -11,7 +11,7 @@ namespace TriangleNet.Rendering.Text
     using System.IO;
     using TriangleNet;
     using TriangleNet.Geometry;
-
+    using TriangleNet.Meshing.Iterators;
     using Color = System.Drawing.Color;
     using IntPoint = System.Drawing.Point;
     using IntRectangle = System.Drawing.Rectangle;

src/Triangle.Rendering/Text/SvgImage.cs

@@ -11,6 +11,7 @@ namespace TriangleNet.Rendering.Text
     using System.Text;
     using TriangleNet;
     using TriangleNet.Geometry;
+    using TriangleNet.Meshing.Iterators;
 
     /// <summary>
     /// Writes a mesh to an SVG file.

src/Triangle/Mesh.cs

@@ -124,11 +124,7 @@ namespace TriangleNet
         {
             get
             {
-                var e = new EdgeIterator(this);
+                return new EdgeIterator().EnumerateEdges(this);
-                while (e.MoveNext())
-                {
-                    yield return e.Current;
-                }
             }
         }
 

src/Triangle/Meshing/Iterators/EdgeIterator.cs

@@ -13,70 +13,28 @@ namespace TriangleNet.Meshing.Iterators
     /// <summary>
     /// Enumerates the edges of a triangulation.
     /// </summary>
-    public class EdgeIterator : IEnumerator<Edge>
+    public class EdgeIterator
     {
-        IEnumerator<Triangle> triangles;
+        public IEnumerable<Edge> EnumerateEdges(Mesh mesh)
-        Otri tri = default(Otri);
+        {
-        Otri neighbor = default(Otri);
+            Otri tri = default;
-        Osub sub = default(Osub);
+            Otri neighbor = default;
-        Edge current;
+            Osub sub = default;
+
             Vertex p1, p2;
 
-        /// <summary>
+            foreach (var t in mesh.triangles)
-        /// Initializes a new instance of the <see cref="EdgeIterator" /> class.
-        /// </summary>
-        public EdgeIterator(Mesh mesh)
             {
-            triangles = mesh.triangles.GetEnumerator();
+                tri.tri = t;
-            triangles.MoveNext();
-
-            tri.tri = triangles.Current;
                 tri.orient = 0;
-        }
 
-        public Edge Current
+                for (int i = 0; i < 3; i++)
                 {
-            get { return current; }
-        }
-
-        public void Dispose()
-        {
-            this.triangles.Dispose();
-        }
-
-        object System.Collections.IEnumerator.Current
-        {
-            get { return current; }
-        }
-
-        public bool MoveNext()
-        {
-            if (tri.tri == null)
-            {
-                return false;
-            }
-
-            current = null;
-
-            while (current == null)
-            {
-                if (tri.orient == 3)
-                {
-                    if (triangles.MoveNext())
-                    {
-                        tri.tri = triangles.Current;
-                        tri.orient = 0;
-                    }
-                    else
-                    {
-                        // Finally no more triangles
-                        return false;
-                    }
-                }
-
                     tri.Sym(ref neighbor);
 
-                if ((tri.tri.id < neighbor.tri.id) || (neighbor.tri.id == Mesh.DUMMY))
+                    int nid = neighbor.tri.id;
+
+                    if ((tri.tri.id < nid) || (nid == Mesh.DUMMY))
                     {
                         p1 = tri.Org();
                         p2 = tri.Dest();
@@ -84,18 +42,67 @@ namespace TriangleNet.Meshing.Iterators
                         tri.Pivot(ref sub);
 
                         // Boundary mark of dummysub is 0, so we don't need to worry about that.
-                    current = new Edge(p1.id, p2.id, sub.seg.boundary);
+                        yield return new Edge(p1.id, p2.id, sub.seg.boundary);
                     }
 
                     tri.orient++;
                 }
-
+            }
-            return true;
         }
 
-        public void Reset()
+        /// <summary>
+        /// Enumerate the edges of the mesh.
+        /// </summary>
+        /// <param name="mesh"></param>
+        /// <param name="skipSegments"></param>
+        /// <returns></returns>
+        /// <remarks>
+        /// In contrast to the <see cref="EnumerateEdges(Mesh)"/> this method will return
+        /// objects that include the vertex information (and not only the indices).
+        /// </remarks>
+        public static IEnumerable<ISegment> EnumerateEdges(Mesh mesh, bool skipSegments = true)
         {
-            this.triangles.Reset();
+            Otri tri = default;
+            Otri neighbor = default;
+            Osub sub = default;
+
+            Vertex p1, p2;
+
+            bool segments = !skipSegments;
+
+            foreach (var t in mesh.triangles)
+            {
+                tri.tri = t;
+                tri.orient = 0;
+
+                for (int i = 0; i < 3; i++)
+                {
+                    tri.Sym(ref neighbor);
+
+                    int nid = neighbor.tri.id;
+
+                    if ((tri.tri.id < nid) || (nid == Mesh.DUMMY))
+                    {
+                        p1 = tri.Org();
+                        p2 = tri.Dest();
+
+                        tri.Pivot(ref sub);
+
+                        if (sub.seg.hash == Mesh.DUMMY)
+                        {
+                            yield return new Segment(p1, p2);
+                        }
+                        else if (segments)
+                        {
+                            // Segments might be processed separately, so only
+                            // include them if requested.
+                            yield return sub.seg;
+                        }
+                    }
+
+                    tri.orient++;
+                }
+            }
         }
     }
 }