diff --git a/Triangle.NET/TestApp/FormMain.cs b/Triangle.NET/TestApp/FormMain.cs
index 2586b67..3a3509c 100644
--- a/Triangle.NET/TestApp/FormMain.cs
+++ b/Triangle.NET/TestApp/FormMain.cs
@@ -617,7 +617,9 @@ namespace MeshExplorer
                 this.voronoi = new StandardVoronoi(mesh);
             }
 
-            renderManager.Set(voronoi.Vertices, voronoi.Edges, false);
+            // HACK: List<Vertex> -> ICollection<Point> ? Nope, no way.
+            //           Vertex[] -> ICollection<Point> ? Well, ok.
+            renderManager.Set(voronoi.Vertices.ToArray(), voronoi.Edges, false);
         }
 
         private void ShowLog()
diff --git a/Triangle.NET/TestApp/IO/EpsImage.cs b/Triangle.NET/TestApp/IO/EpsImage.cs
index 81bc10d..cf2974a 100644
--- a/Triangle.NET/TestApp/IO/EpsImage.cs
+++ b/Triangle.NET/TestApp/IO/EpsImage.cs
@@ -11,7 +11,7 @@ namespace MeshExplorer.IO
     using System.IO;
     using System.Text;
     using TriangleNet;
-    using TriangleNet.Data;
+    using TriangleNet.Topology;
     using TriangleNet.Geometry;
 
     /// <summary>
diff --git a/Triangle.NET/TestApp/IO/Formats/JsonFile.cs b/Triangle.NET/TestApp/IO/Formats/JsonFile.cs
index e24590a..b75f50e 100644
--- a/Triangle.NET/TestApp/IO/Formats/JsonFile.cs
+++ b/Triangle.NET/TestApp/IO/Formats/JsonFile.cs
@@ -12,7 +12,7 @@ namespace MeshExplorer.IO.Formats
     using System.IO;
     using System.Text;
     using TriangleNet;
-    using TriangleNet.Data;
+    using TriangleNet.Topology;
     using TriangleNet.Geometry;
     using TriangleNet.IO;
     using TriangleNet.Meshing;
diff --git a/Triangle.NET/TestApp/Topology/OrientedTriangle.cs b/Triangle.NET/TestApp/Topology/OrientedTriangle.cs
index 912da20..22926c4 100644
--- a/Triangle.NET/TestApp/Topology/OrientedTriangle.cs
+++ b/Triangle.NET/TestApp/Topology/OrientedTriangle.cs
@@ -1,7 +1,7 @@
 
 namespace MeshExplorer.Topology
 {
-    using TriangleNet.Data;
+    using TriangleNet.Topology;
     using TriangleNet.Geometry;
 
     public class OrientedTriangle
diff --git a/Triangle.NET/Triangle.Rendering/IRenderContext.cs b/Triangle.NET/Triangle.Rendering/IRenderContext.cs
index fac3ae5..6b1b638 100644
--- a/Triangle.NET/Triangle.Rendering/IRenderContext.cs
+++ b/Triangle.NET/Triangle.Rendering/IRenderContext.cs
@@ -22,7 +22,7 @@ namespace TriangleNet.Rendering
 
         void Add(IPolygon data);
         void Add(IMesh data, bool reset);
-        void Add(Point[] points, IEnumerable<IEdge> edges, bool reset);
+        void Add(ICollection<Point> points, IEnumerable<IEdge> edges, bool reset);
 
         void Add(float[] values);
         void Add(int[] partition);
diff --git a/Triangle.NET/Triangle.Rendering/IRenderLayer.cs b/Triangle.NET/Triangle.Rendering/IRenderLayer.cs
index 01d35c6..09a30fa 100644
--- a/Triangle.NET/Triangle.Rendering/IRenderLayer.cs
+++ b/Triangle.NET/Triangle.Rendering/IRenderLayer.cs
@@ -26,7 +26,7 @@ namespace TriangleNet.Rendering
         BoundingBox SetPoints(IBuffer<float> buffer);
         BoundingBox SetPoints(IPolygon poly);
         BoundingBox SetPoints(IMesh mesh);
-        BoundingBox SetPoints(Point[] points);
+        BoundingBox SetPoints(ICollection<Point> points);
         void SetPolygon(IPolygon poly);
         void SetPolygon(IMesh mesh);
         void SetMesh(IMesh mesh, bool elements);
diff --git a/Triangle.NET/Triangle.Rendering/RenderContext.cs b/Triangle.NET/Triangle.Rendering/RenderContext.cs
index 3c759f5..b16bea4 100644
--- a/Triangle.NET/Triangle.Rendering/RenderContext.cs
+++ b/Triangle.NET/Triangle.Rendering/RenderContext.cs
@@ -117,7 +117,7 @@ namespace TriangleNet.Rendering
             RenderLayers[3].IsActive = true;
         }
 
-        public void Add(Point[] points, IEnumerable<IEdge> edges, bool reset)
+        public void Add(ICollection<Point> points, IEnumerable<IEdge> edges, bool reset)
         {
             RenderLayers[4].SetPoints(points);
             RenderLayers[4].SetMesh(edges);
diff --git a/Triangle.NET/Triangle.Rendering/RenderLayer.cs b/Triangle.NET/Triangle.Rendering/RenderLayer.cs
index 992fc66..7bc7997 100644
--- a/Triangle.NET/Triangle.Rendering/RenderLayer.cs
+++ b/Triangle.NET/Triangle.Rendering/RenderLayer.cs
@@ -108,7 +108,7 @@ namespace TriangleNet.Rendering
             return bounds;
         }
 
-        public BoundingBox SetPoints(Point[] vertices)
+        public BoundingBox SetPoints(ICollection<Point> vertices)
         {
             BoundingBox bounds = new BoundingBox();
 
diff --git a/Triangle.NET/Triangle.Rendering/RenderManager.cs b/Triangle.NET/Triangle.Rendering/RenderManager.cs
index 38b8213..c0352d5 100644
--- a/Triangle.NET/Triangle.Rendering/RenderManager.cs
+++ b/Triangle.NET/Triangle.Rendering/RenderManager.cs
@@ -117,7 +117,7 @@ namespace TriangleNet.Rendering
         /// <summary>
         /// Set data for Voronoi layer.
         /// </summary>
-        public void Set(Point[] points, IEnumerable<IEdge> edges, bool reset, bool refresh = true)
+        public void Set(ICollection<Point> points, IEnumerable<IEdge> edges, bool reset, bool refresh = true)
         {
             context.Add(points, edges, reset);
 
diff --git a/Triangle.NET/Triangle.Rendering/Util/BufferHelper.cs b/Triangle.NET/Triangle.Rendering/Util/BufferHelper.cs
index 1b517fd..b6e8b52 100644
--- a/Triangle.NET/Triangle.Rendering/Util/BufferHelper.cs
+++ b/Triangle.NET/Triangle.Rendering/Util/BufferHelper.cs
@@ -2,7 +2,7 @@
 namespace TriangleNet.Rendering.Util
 {
     using System.Collections.Generic;
-    using TriangleNet.Data;
+    using TriangleNet.Topology;
     using TriangleNet.Geometry;
     using TriangleNet.Rendering.Buffer;
 
@@ -36,9 +36,9 @@ namespace TriangleNet.Rendering.Util
             return buffer as IBuffer<float>;
         }
 
-        public static IBuffer<float> CreateVertexBuffer(Point[] points, ref BoundingBox bounds)
+        public static IBuffer<float> CreateVertexBuffer(ICollection<Point> points, ref BoundingBox bounds)
         {
-            var buffer = new VertexBuffer(2 * points.Length);
+            var buffer = new VertexBuffer(2 * points.Count);
 
             bounds.Reset();
 
diff --git a/Triangle.NET/Triangle/Geometry/Edge.cs b/Triangle.NET/Triangle/Geometry/Edge.cs
index d7c28d7..15d7482 100644
--- a/Triangle.NET/Triangle/Geometry/Edge.cs
+++ b/Triangle.NET/Triangle/Geometry/Edge.cs
@@ -10,7 +10,7 @@ namespace TriangleNet.Geometry
     using System.Collections.Generic;
     using System.Linq;
     using System.Text;
-    using TriangleNet.Data;
+    using TriangleNet.Topology;
 
     /// <summary>
     /// Represents a straight line segment in 2D space.
diff --git a/Triangle.NET/Triangle/Geometry/ExtensionMethods.cs b/Triangle.NET/Triangle/Geometry/ExtensionMethods.cs
new file mode 100644
index 0000000..a164891
--- /dev/null
+++ b/Triangle.NET/Triangle/Geometry/ExtensionMethods.cs
@@ -0,0 +1,145 @@
+
+namespace TriangleNet.Geometry
+{
+    using TriangleNet.Meshing;
+
+    public static class ExtensionMethods
+    {
+        #region IPolygon extensions
+
+        /// <summary>
+        /// Triangulates a polygon.
+        /// </summary>
+        public static IMesh Triangulate(this IPolygon polygon)
+        {
+            var mesher = new GenericMesher();
+
+            return mesher.Triangulate(polygon, null, null);
+        }
+
+        /// <summary>
+        /// Triangulates a polygon, applying constraint options.
+        /// </summary>
+        /// <param name="options">Constraint options.</param>
+        public static IMesh Triangulate(this IPolygon polygon, ConstraintOptions options)
+        {
+            var mesher = new GenericMesher();
+
+            return mesher.Triangulate(polygon, options, null);
+        }
+
+        /// <summary>
+        /// Triangulates a polygon, applying quality options.
+        /// </summary>
+        /// <param name="quality">Quality options.</param>
+        public static IMesh Triangulate(this IPolygon polygon, QualityOptions quality)
+        {
+            var mesher = new GenericMesher();
+
+            return mesher.Triangulate(polygon, null, quality);
+        }
+
+        /// <summary>
+        /// Triangulates a polygon, applying quality and constraint options.
+        /// </summary>
+        /// <param name="options">Constraint options.</param>
+        /// <param name="quality">Quality options.</param>
+        public static IMesh Triangulate(this IPolygon polygon, ConstraintOptions options, QualityOptions quality)
+        {
+            var mesher = new GenericMesher();
+
+            var mesh = (Mesh)mesher.Triangulate(polygon.Points);
+
+            mesh.ApplyConstraints(polygon, options, quality);
+
+            return mesh;
+        }
+
+        /// <summary>
+        /// Triangulates a polygon, applying quality and constraint options.
+        /// </summary>
+        /// <param name="options">Constraint options.</param>
+        /// <param name="quality">Quality options.</param>
+        /// <param name="triangulator">The triangulation algorithm.</param>
+        public static IMesh Triangulate(this IPolygon polygon, ConstraintOptions options, QualityOptions quality,
+            ITriangulator triangulator)
+        {
+            var mesher = new GenericMesher(triangulator);
+
+            var mesh = (Mesh)mesher.Triangulate(polygon.Points);
+
+            mesh.ApplyConstraints(polygon, options, quality);
+
+            return mesh;
+        }
+
+        #endregion
+
+        #region Rectangle extensions
+
+        /// <summary>
+        /// Find intersection of a rectangle with a segment.
+        /// </summary>
+        /// <param name="rect">The rectangle.</param>
+        /// <param name="p0">Segment start point.</param>
+        /// <param name="p1">Segment end point.</param>
+        /// <param name="c0">Intersection associated to start point.</param>
+        /// <param name="c1">Intersection associated to end point.</param>
+        /// <returns>Returns true, if segment intersects or lies completely in rectangle, otherwise false.</returns>
+        /// <remarks>
+        /// Liang-Barsky function by Daniel White, http://www.skytopia.com/project/articles/compsci/clipping.html
+        /// </remarks>
+        public static bool Intersect(this Rectangle rect, Point p0, Point p1, ref Point c0, ref Point c1)
+        {
+            // Define the x/y clipping values for the border.
+            double xmin = rect.Left;
+            double xmax = rect.Right;
+            double ymin = rect.Bottom;
+            double ymax = rect.Top;
+
+            // Define the start and end points of the line.
+            double x0 = p0.X;
+            double y0 = p0.Y;
+            double x1 = p1.X;
+            double y1 = p1.Y;
+
+            double t0 = 0.0;
+            double t1 = 1.0;
+
+            double dx = x1 - x0;
+            double dy = y1 - y0;
+
+            double p = 0.0, q = 0.0, r;
+
+            for (int edge = 0; edge < 4; edge++)
+            {
+                // Traverse through left, right, bottom, top edges.
+                if (edge == 0) { p = -dx; q = -(xmin - x0); }
+                if (edge == 1) { p = dx; q = (xmax - x0); }
+                if (edge == 2) { p = -dy; q = -(ymin - y0); }
+                if (edge == 3) { p = dy; q = (ymax - y0); }
+                r = q / p;
+                if (p == 0 && q < 0) return false; // Don't draw line at all. (parallel line outside)
+                if (p < 0)
+                {
+                    if (r > t1) return false; // Don't draw line at all.
+                    else if (r > t0) t0 = r; // Line is clipped!
+                }
+                else if (p > 0)
+                {
+                    if (r < t0) return false; // Don't draw line at all.
+                    else if (r < t1) t1 = r; // Line is clipped!
+                }
+            }
+
+            c0.x = x0 + t0 * dx;
+            c0.y = y0 + t0 * dy;
+            c1.x = x0 + t1 * dx;
+            c1.y = y0 + t1 * dy;
+
+            return true; // (clipped) line is drawn
+        }
+
+        #endregion
+    }
+}
diff --git a/Triangle.NET/Triangle/Geometry/IPolygon.cs b/Triangle.NET/Triangle/Geometry/IPolygon.cs
index dc078fb..a99672c 100644
--- a/Triangle.NET/Triangle/Geometry/IPolygon.cs
+++ b/Triangle.NET/Triangle/Geometry/IPolygon.cs
@@ -2,7 +2,7 @@
 namespace TriangleNet.Geometry
 {
     using System.Collections.Generic;
-    using TriangleNet.Data;
+    using TriangleNet.Topology;
 
     /// <summary>
     /// Polygon interface.
diff --git a/Triangle.NET/Triangle/Geometry/IPolygonExtensions.cs b/Triangle.NET/Triangle/Geometry/IPolygonExtensions.cs
deleted file mode 100644
index a33ccf6..0000000
--- a/Triangle.NET/Triangle/Geometry/IPolygonExtensions.cs
+++ /dev/null
@@ -1,74 +0,0 @@
-
-namespace TriangleNet.Geometry
-{
-    using TriangleNet.Meshing;
-
-    public static class IPolygonExtensions
-    {
-        /// <summary>
-        /// Triangulates a polygon.
-        /// </summary>
-        public static IMesh Triangulate(this IPolygon polygon)
-        {
-            var mesher = new GenericMesher();
-
-            return mesher.Triangulate(polygon, null, null);
-        }
-
-        /// <summary>
-        /// Triangulates a polygon, applying constraint options.
-        /// </summary>
-        /// <param name="options">Constraint options.</param>
-        public static IMesh Triangulate(this IPolygon polygon, ConstraintOptions options)
-        {
-            var mesher = new GenericMesher();
-
-            return mesher.Triangulate(polygon, options, null);
-        }
-
-        /// <summary>
-        /// Triangulates a polygon, applying quality options.
-        /// </summary>
-        /// <param name="quality">Quality options.</param>
-        public static IMesh Triangulate(this IPolygon polygon, QualityOptions quality)
-        {
-            var mesher = new GenericMesher();
-
-            return mesher.Triangulate(polygon, null, quality);
-        }
-
-        /// <summary>
-        /// Triangulates a polygon, applying quality and constraint options.
-        /// </summary>
-        /// <param name="options">Constraint options.</param>
-        /// <param name="quality">Quality options.</param>
-        public static IMesh Triangulate(this IPolygon polygon, ConstraintOptions options, QualityOptions quality)
-        {
-            var mesher = new GenericMesher();
-
-            var mesh = (Mesh)mesher.Triangulate(polygon.Points);
-
-            mesh.ApplyConstraints(polygon, options, quality);
-
-            return mesh;
-        }
-
-        /// <summary>
-        /// Triangulates a polygon, applying quality and constraint options.
-        /// </summary>
-        /// <param name="options">Constraint options.</param>
-        /// <param name="quality">Quality options.</param>
-        /// <param name="triangulator">The triangulation algorithm.</param>
-        public static IMesh Triangulate(this IPolygon polygon, ConstraintOptions options, QualityOptions quality,
-            ITriangulator triangulator)
-        {
-            var mesher = new GenericMesher(triangulator);
-
-            var mesh = (Mesh)mesher.Triangulate(polygon.Points);
-
-            mesh.ApplyConstraints(polygon, options, quality);
-
-            return mesh;
-        }
-    }
-}
diff --git a/Triangle.NET/Triangle/Geometry/ITriangle.cs b/Triangle.NET/Triangle/Geometry/ITriangle.cs
index a7f78e6..93d78d0 100644
--- a/Triangle.NET/Triangle/Geometry/ITriangle.cs
+++ b/Triangle.NET/Triangle/Geometry/ITriangle.cs
@@ -6,7 +6,7 @@
 
 namespace TriangleNet.Geometry
 {
-    using TriangleNet.Data;
+    using TriangleNet.Topology;
 
     /// <summary>
     /// Triangle interface.
diff --git a/Triangle.NET/Triangle/Geometry/Polygon.cs b/Triangle.NET/Triangle/Geometry/Polygon.cs
index 733c96c..1b113e7 100644
--- a/Triangle.NET/Triangle/Geometry/Polygon.cs
+++ b/Triangle.NET/Triangle/Geometry/Polygon.cs
@@ -3,7 +3,7 @@ namespace TriangleNet.Geometry
 {
     using System;
     using System.Collections.Generic;
-    using TriangleNet.Data;
+    using TriangleNet.Topology;
 
     /// <summary>
     /// A polygon represented as a planar straight line graph.
diff --git a/Triangle.NET/Triangle/Geometry/Vertex.cs b/Triangle.NET/Triangle/Geometry/Vertex.cs
index ca5dc8d..43325f0 100644
--- a/Triangle.NET/Triangle/Geometry/Vertex.cs
+++ b/Triangle.NET/Triangle/Geometry/Vertex.cs
@@ -8,7 +8,7 @@
 namespace TriangleNet.Geometry
 {
     using System;
-    using TriangleNet.Data;
+    using TriangleNet.Topology;
 
     /// <summary>
     /// The vertex data structure.
diff --git a/Triangle.NET/Triangle/IO/DebugWriter.cs b/Triangle.NET/Triangle/IO/DebugWriter.cs
index a8f2409..e7c95fb 100644
--- a/Triangle.NET/Triangle/IO/DebugWriter.cs
+++ b/Triangle.NET/Triangle/IO/DebugWriter.cs
@@ -11,7 +11,7 @@ namespace TriangleNet.IO
     using System.IO;
     using System.IO.Compression;
     using System.Text;
-    using TriangleNet.Data;
+    using TriangleNet.Topology;
     using TriangleNet.Geometry;
 
     /// <summary>
diff --git a/Triangle.NET/Triangle/IO/InputTriangle.cs b/Triangle.NET/Triangle/IO/InputTriangle.cs
index cf57fa9..32ca324 100644
--- a/Triangle.NET/Triangle/IO/InputTriangle.cs
+++ b/Triangle.NET/Triangle/IO/InputTriangle.cs
@@ -6,7 +6,7 @@
 
 namespace TriangleNet.IO
 {
-    using TriangleNet.Data;
+    using TriangleNet.Topology;
     using TriangleNet.Geometry;
 
     /// <summary>
diff --git a/Triangle.NET/Triangle/IO/TriangleReader.cs b/Triangle.NET/Triangle/IO/TriangleReader.cs
index 1e5dd91..bd10ba6 100644
--- a/Triangle.NET/Triangle/IO/TriangleReader.cs
+++ b/Triangle.NET/Triangle/IO/TriangleReader.cs
@@ -10,7 +10,7 @@ namespace TriangleNet.IO
     using System;
     using System.IO;
     using System.Globalization;
-    using TriangleNet.Data;
+    using TriangleNet.Topology;
     using TriangleNet.Logging;
     using TriangleNet.Geometry;
     using System.Collections.Generic;
diff --git a/Triangle.NET/Triangle/IO/TriangleWriter.cs b/Triangle.NET/Triangle/IO/TriangleWriter.cs
index 9dd1a15..2b21f93 100644
--- a/Triangle.NET/Triangle/IO/TriangleWriter.cs
+++ b/Triangle.NET/Triangle/IO/TriangleWriter.cs
@@ -10,7 +10,7 @@ namespace TriangleNet.IO
     using System;
     using System.IO;
     using System.Globalization;
-    using TriangleNet.Data;
+    using TriangleNet.Topology;
     using TriangleNet.Geometry;
     using System.Collections.Generic;
 
diff --git a/Triangle.NET/Triangle/Mesh.cs b/Triangle.NET/Triangle/Mesh.cs
index fb66d70..1749fe5 100644
--- a/Triangle.NET/Triangle/Mesh.cs
+++ b/Triangle.NET/Triangle/Mesh.cs
@@ -9,12 +9,13 @@ namespace TriangleNet
 {
     using System;
     using System.Collections.Generic;
-    using TriangleNet.Data;
     using TriangleNet.Geometry;
     using TriangleNet.Logging;
     using TriangleNet.Meshing;
+    using TriangleNet.Meshing.Data;
     using TriangleNet.Meshing.Iterators;
     using TriangleNet.Tools;
+    using TriangleNet.Topology;
 
     /// <summary>
     /// Mesh data structure.
diff --git a/Triangle.NET/Triangle/MeshValidator.cs b/Triangle.NET/Triangle/MeshValidator.cs
index b132282..1cb0999 100644
--- a/Triangle.NET/Triangle/MeshValidator.cs
+++ b/Triangle.NET/Triangle/MeshValidator.cs
@@ -8,7 +8,7 @@
 namespace TriangleNet
 {
     using System;
-    using TriangleNet.Data;
+    using TriangleNet.Topology;
     using TriangleNet.Geometry;
 
     public static class MeshValidator
diff --git a/Triangle.NET/Triangle/Meshing/Algorithm/Dwyer.cs b/Triangle.NET/Triangle/Meshing/Algorithm/Dwyer.cs
index d9091dc..d34bc21 100644
--- a/Triangle.NET/Triangle/Meshing/Algorithm/Dwyer.cs
+++ b/Triangle.NET/Triangle/Meshing/Algorithm/Dwyer.cs
@@ -9,7 +9,7 @@ namespace TriangleNet.Meshing.Algorithm
 {
     using System;
     using System.Collections.Generic;
-    using TriangleNet.Data;
+    using TriangleNet.Topology;
     using TriangleNet.Geometry;
 
     /// <summary>
diff --git a/Triangle.NET/Triangle/Meshing/Algorithm/Incremental.cs b/Triangle.NET/Triangle/Meshing/Algorithm/Incremental.cs
index 0a3c5e1..26777e4 100644
--- a/Triangle.NET/Triangle/Meshing/Algorithm/Incremental.cs
+++ b/Triangle.NET/Triangle/Meshing/Algorithm/Incremental.cs
@@ -8,7 +8,7 @@
 namespace TriangleNet.Meshing.Algorithm
 {
     using System.Collections.Generic;
-    using TriangleNet.Data;
+    using TriangleNet.Topology;
     using TriangleNet.Geometry;
 
     /// <summary>
diff --git a/Triangle.NET/Triangle/Meshing/Algorithm/SweepLine.cs b/Triangle.NET/Triangle/Meshing/Algorithm/SweepLine.cs
index 00fd07d..4440ce8 100644
--- a/Triangle.NET/Triangle/Meshing/Algorithm/SweepLine.cs
+++ b/Triangle.NET/Triangle/Meshing/Algorithm/SweepLine.cs
@@ -9,7 +9,7 @@ namespace TriangleNet.Meshing.Algorithm
 {
     using System;
     using System.Collections.Generic;
-    using TriangleNet.Data;
+    using TriangleNet.Topology;
     using TriangleNet.Geometry;
     using TriangleNet.Tools;
 
diff --git a/Triangle.NET/Triangle/Meshing/ConstraintMesher.cs b/Triangle.NET/Triangle/Meshing/ConstraintMesher.cs
index 4a738da..f039ae8 100644
--- a/Triangle.NET/Triangle/Meshing/ConstraintMesher.cs
+++ b/Triangle.NET/Triangle/Meshing/ConstraintMesher.cs
@@ -9,7 +9,7 @@ namespace TriangleNet.Meshing
 {
     using System;
     using System.Collections.Generic;
-    using TriangleNet.Data;
+    using TriangleNet.Topology;
     using TriangleNet.Geometry;
     using TriangleNet.Logging;
     using TriangleNet.Meshing.Iterators;
diff --git a/Triangle.NET/Triangle/Meshing/Converter.cs b/Triangle.NET/Triangle/Meshing/Converter.cs
index 946523c..5d0029b 100644
--- a/Triangle.NET/Triangle/Meshing/Converter.cs
+++ b/Triangle.NET/Triangle/Meshing/Converter.cs
@@ -10,7 +10,7 @@ namespace TriangleNet.Meshing
     using System;
     using System.Collections.Generic;
     using System.Linq;
-    using TriangleNet.Data;
+    using TriangleNet.Topology;
     using TriangleNet.Geometry;
 
     /// <summary>
diff --git a/Triangle.NET/Triangle/Data/BadSubseg.cs b/Triangle.NET/Triangle/Meshing/Data/BadSubseg.cs
similarity index 91%
rename from Triangle.NET/Triangle/Data/BadSubseg.cs
rename to Triangle.NET/Triangle/Meshing/Data/BadSubseg.cs
index 9db815a..85f23a2 100644
--- a/Triangle.NET/Triangle/Data/BadSubseg.cs
+++ b/Triangle.NET/Triangle/Meshing/Data/BadSubseg.cs
@@ -5,10 +5,11 @@
 // </copyright>
 // -----------------------------------------------------------------------
 
-namespace TriangleNet.Data
+namespace TriangleNet.Meshing.Data
 {
     using System;
     using TriangleNet.Geometry;
+    using TriangleNet.Topology;
 
     /// <summary>
     /// A queue used to store encroached subsegments.
diff --git a/Triangle.NET/Triangle/Data/BadTriQueue.cs b/Triangle.NET/Triangle/Meshing/Data/BadTriQueue.cs
similarity index 96%
rename from Triangle.NET/Triangle/Data/BadTriQueue.cs
rename to Triangle.NET/Triangle/Meshing/Data/BadTriQueue.cs
index 2670870..87d5d18 100644
--- a/Triangle.NET/Triangle/Data/BadTriQueue.cs
+++ b/Triangle.NET/Triangle/Meshing/Data/BadTriQueue.cs
@@ -5,9 +5,10 @@
 // </copyright>
 // -----------------------------------------------------------------------
 
-namespace TriangleNet.Data
+namespace TriangleNet.Meshing.Data
 {
     using TriangleNet.Geometry;
+    using TriangleNet.Topology;
 
     /// <summary>
     /// A (priority) queue for bad triangles.
diff --git a/Triangle.NET/Triangle/Data/BadTriangle.cs b/Triangle.NET/Triangle/Meshing/Data/BadTriangle.cs
similarity index 92%
rename from Triangle.NET/Triangle/Data/BadTriangle.cs
rename to Triangle.NET/Triangle/Meshing/Data/BadTriangle.cs
index cd48829..544742e 100644
--- a/Triangle.NET/Triangle/Data/BadTriangle.cs
+++ b/Triangle.NET/Triangle/Meshing/Data/BadTriangle.cs
@@ -5,10 +5,11 @@
 // </copyright>
 // -----------------------------------------------------------------------
 
-namespace TriangleNet.Data
+namespace TriangleNet.Meshing.Data
 {
     using System;
     using TriangleNet.Geometry;
+    using TriangleNet.Topology;
 
     /// <summary>
     /// A queue used to store bad triangles.
diff --git a/Triangle.NET/Triangle/Meshing/IMesh.cs b/Triangle.NET/Triangle/Meshing/IMesh.cs
index 4db2e5e..1e6a1be 100644
--- a/Triangle.NET/Triangle/Meshing/IMesh.cs
+++ b/Triangle.NET/Triangle/Meshing/IMesh.cs
@@ -2,7 +2,7 @@
 namespace TriangleNet.Meshing
 {
     using System.Collections.Generic;
-    using TriangleNet.Data;
+    using TriangleNet.Topology;
     using TriangleNet.Geometry;
 
     /// <summary>
diff --git a/Triangle.NET/Triangle/Meshing/Iterators/EdgeIterator.cs b/Triangle.NET/Triangle/Meshing/Iterators/EdgeIterator.cs
index 3fd4f95..5e05a15 100644
--- a/Triangle.NET/Triangle/Meshing/Iterators/EdgeIterator.cs
+++ b/Triangle.NET/Triangle/Meshing/Iterators/EdgeIterator.cs
@@ -7,7 +7,7 @@
 namespace TriangleNet.Meshing.Iterators
 {
     using System.Collections.Generic;
-    using TriangleNet.Data;
+    using TriangleNet.Topology;
     using TriangleNet.Geometry;
 
     /// <summary>
diff --git a/Triangle.NET/Triangle/Meshing/Iterators/RegionIterator.cs b/Triangle.NET/Triangle/Meshing/Iterators/RegionIterator.cs
index 2dda7f3..60b07ca 100644
--- a/Triangle.NET/Triangle/Meshing/Iterators/RegionIterator.cs
+++ b/Triangle.NET/Triangle/Meshing/Iterators/RegionIterator.cs
@@ -9,7 +9,7 @@ namespace TriangleNet.Meshing.Iterators
 {
     using System;
     using System.Collections.Generic;
-    using TriangleNet.Data;
+    using TriangleNet.Topology;
 
     /// <summary>
     /// Iterates the region a given triangle belongs to and applies an action
diff --git a/Triangle.NET/Triangle/Meshing/QualityMesher.cs b/Triangle.NET/Triangle/Meshing/QualityMesher.cs
index 4fc0a11..1ce2ecf 100644
--- a/Triangle.NET/Triangle/Meshing/QualityMesher.cs
+++ b/Triangle.NET/Triangle/Meshing/QualityMesher.cs
@@ -9,9 +9,10 @@ namespace TriangleNet.Meshing
 {
     using System;
     using System.Collections.Generic;
-    using TriangleNet.Data;
     using TriangleNet.Geometry;
     using TriangleNet.Logging;
+    using TriangleNet.Meshing.Data;
+    using TriangleNet.Topology;
 
     /// <summary>
     /// Provides methods for mesh quality enforcement and testing.
diff --git a/Triangle.NET/Triangle/Meshing/QualityOptions.cs b/Triangle.NET/Triangle/Meshing/QualityOptions.cs
index a543ee1..bf9f8b8 100644
--- a/Triangle.NET/Triangle/Meshing/QualityOptions.cs
+++ b/Triangle.NET/Triangle/Meshing/QualityOptions.cs
@@ -35,7 +35,7 @@ namespace TriangleNet.Meshing
         public Func<ITriangle, double, bool> UserTest { get; set; }
 
         /// <summary>
-        /// Gets or sets a area constraint per triangle.
+        /// Gets or sets an area constraint per triangle.
         /// </summary>
         /// <remarks>
         /// If this flag is set to true, the <see cref="ITriangle.Area"/> value will
diff --git a/Triangle.NET/Triangle/NewLocation.cs b/Triangle.NET/Triangle/NewLocation.cs
index 55686eb..fb71f49 100644
--- a/Triangle.NET/Triangle/NewLocation.cs
+++ b/Triangle.NET/Triangle/NewLocation.cs
@@ -8,7 +8,7 @@
 namespace TriangleNet
 {
     using System;
-    using TriangleNet.Data;
+    using TriangleNet.Topology;
     using TriangleNet.Geometry;
     using TriangleNet.Tools;
 
diff --git a/Triangle.NET/Triangle/RobustPredicates.cs b/Triangle.NET/Triangle/RobustPredicates.cs
index 2f36347..7c93801 100644
--- a/Triangle.NET/Triangle/RobustPredicates.cs
+++ b/Triangle.NET/Triangle/RobustPredicates.cs
@@ -8,7 +8,7 @@
 namespace TriangleNet
 {
     using System;
-    using TriangleNet.Data;
+    using TriangleNet.Topology;
     using TriangleNet.Geometry;
     using TriangleNet.Tools;
 
diff --git a/Triangle.NET/Triangle/Tools/Statistic.cs b/Triangle.NET/Triangle/Tools/Statistic.cs
index 20c3f65..5ca43ce 100644
--- a/Triangle.NET/Triangle/Tools/Statistic.cs
+++ b/Triangle.NET/Triangle/Tools/Statistic.cs
@@ -8,7 +8,7 @@
 namespace TriangleNet.Tools
 {
     using System;
-    using TriangleNet.Data;
+    using TriangleNet.Topology;
     using TriangleNet.Geometry;
 
     /// <summary>
diff --git a/Triangle.NET/Triangle/Topology/DCEL/DcelMesh.cs b/Triangle.NET/Triangle/Topology/DCEL/DcelMesh.cs
new file mode 100644
index 0000000..1276766
--- /dev/null
+++ b/Triangle.NET/Triangle/Topology/DCEL/DcelMesh.cs
@@ -0,0 +1,119 @@
+
+namespace TriangleNet.Topology.DCEL
+{
+    using System.Collections.Generic;
+    using TriangleNet.Geometry;
+
+    public class DcelMesh
+    {
+        protected List<Vertex> vertices;
+        protected List<HalfEdge> edges;
+        protected List<Face> faces;
+
+        public DcelMesh()
+            : this(true)
+        {
+        }
+
+        protected DcelMesh(bool initialize)
+        {
+            if (initialize)
+            {
+                vertices = new List<Vertex>();
+                edges = new List<HalfEdge>();
+                faces = new List<Face>();
+            }
+        }
+
+        /// <summary>
+        /// Gets the vertices of the Voronoi diagram.
+        /// </summary>
+        public List<Vertex> Vertices
+        {
+            get { return vertices; }
+        }
+
+        /// <summary>
+        /// Gets the list of half-edges specify the Voronoi diagram topology.
+        /// </summary>
+        public List<HalfEdge> HalfEdges
+        {
+            get { return edges; }
+        }
+
+        /// <summary>
+        /// Gets the faces of the Voronoi diagram.
+        /// </summary>
+        public List<Face> Faces
+        {
+            get { return faces; }
+        }
+
+        /// <summary>
+        /// Gets the collection of edges of the Voronoi diagram.
+        /// </summary>
+        public IEnumerable<IEdge> Edges
+        {
+            get { return EnumerateEdges(); }
+        }
+
+        /// <summary>
+        /// Search for half-edge without twin and add a twin. Connect twins to form connected
+        /// boundary contours.
+        /// </summary>
+        /// <remarks>
+        /// This method assumes that all faces are closed (i.e. no edge.next pointers are null).
+        /// </remarks>
+        internal void ResolveBoundaryEdges()
+        {
+            // Maps vertices to leaving boundary edge.
+            var map = new Dictionary<int, HalfEdge>();
+
+            // TODO: parallel?
+            foreach (var edge in this.edges)
+            {
+                if (edge.twin == null)
+                {
+                    var twin = edge.twin = new HalfEdge(edge.next.origin);
+                    twin.twin = edge;
+
+                    map.Add(twin.origin.id, twin);
+                }
+            }
+
+            int j = edges.Count;
+
+            foreach (var edge in map.Values)
+            {
+                edge.id = j++;
+                edge.next = map[edge.twin.origin.id];
+
+                this.edges.Add(edge);
+            }
+        }
+
+        /// <summary>
+        /// Enumerates all edges of the DCEL.
+        /// </summary>
+        /// <remarks>
+        /// This method assumes that each half-edge has a twin (i.e. NOT null).
+        /// </remarks>
+        protected virtual IEnumerable<IEdge> EnumerateEdges()
+        {
+            var edges = new List<IEdge>(this.edges.Count / 2);
+
+            foreach (var edge in this.edges)
+            {
+                var twin = edge.twin;
+
+                // Report edge only once.
+                if (edge.id < twin.id)
+                {
+                    edges.Add(new Edge(edge.origin.id, twin.origin.id));
+                }
+            }
+
+            return edges;
+        }
+    }
+}
diff --git a/Triangle.NET/Triangle/Voronoi/DCEL/Face.cs b/Triangle.NET/Triangle/Topology/DCEL/Face.cs
similarity index 93%
rename from Triangle.NET/Triangle/Voronoi/DCEL/Face.cs
rename to Triangle.NET/Triangle/Topology/DCEL/Face.cs
index 1bb3e39..b2b0102 100644
--- a/Triangle.NET/Triangle/Voronoi/DCEL/Face.cs
+++ b/Triangle.NET/Triangle/Topology/DCEL/Face.cs
@@ -4,7 +4,7 @@
 // </copyright>
 // -----------------------------------------------------------------------
 
-namespace TriangleNet.Voronoi.DCEL
+namespace TriangleNet.Topology.DCEL
 {
     using TriangleNet.Geometry;
 
@@ -13,6 +13,8 @@ namespace TriangleNet.Voronoi.DCEL
     /// </summary>
     public class Face
     {
+        internal int id;
+
         internal Point generator;
 
         internal HalfEdge edge;
diff --git a/Triangle.NET/Triangle/Voronoi/DCEL/HalfEdge.cs b/Triangle.NET/Triangle/Topology/DCEL/HalfEdge.cs
similarity index 95%
rename from Triangle.NET/Triangle/Voronoi/DCEL/HalfEdge.cs
rename to Triangle.NET/Triangle/Topology/DCEL/HalfEdge.cs
index 8d1e8b0..0d85b77 100644
--- a/Triangle.NET/Triangle/Voronoi/DCEL/HalfEdge.cs
+++ b/Triangle.NET/Triangle/Topology/DCEL/HalfEdge.cs
@@ -4,7 +4,7 @@
 // </copyright>
 // -----------------------------------------------------------------------
 
-namespace TriangleNet.Voronoi.DCEL
+namespace TriangleNet.Topology.DCEL
 {
     public class HalfEdge
     {
diff --git a/Triangle.NET/Triangle/Voronoi/DCEL/Vertex.cs b/Triangle.NET/Triangle/Topology/DCEL/Vertex.cs
similarity index 90%
rename from Triangle.NET/Triangle/Voronoi/DCEL/Vertex.cs
rename to Triangle.NET/Triangle/Topology/DCEL/Vertex.cs
index cb1cdf5..966d916 100644
--- a/Triangle.NET/Triangle/Voronoi/DCEL/Vertex.cs
+++ b/Triangle.NET/Triangle/Topology/DCEL/Vertex.cs
@@ -4,11 +4,9 @@
 // </copyright>
 // -----------------------------------------------------------------------
 
-namespace TriangleNet.Voronoi.DCEL
+namespace TriangleNet.Topology.DCEL
 {
-    using TriangleNet.Geometry;
-
-    public class Vertex : Point
+    public class Vertex : TriangleNet.Geometry.Point
     {
         internal HalfEdge leaving;
 
diff --git a/Triangle.NET/Triangle/Data/Osub.cs b/Triangle.NET/Triangle/Topology/Osub.cs
similarity index 96%
rename from Triangle.NET/Triangle/Data/Osub.cs
rename to Triangle.NET/Triangle/Topology/Osub.cs
index ebef407..c06c681 100644
--- a/Triangle.NET/Triangle/Data/Osub.cs
+++ b/Triangle.NET/Triangle/Topology/Osub.cs
@@ -5,7 +5,7 @@
 // </copyright>
 // -----------------------------------------------------------------------
 
-namespace TriangleNet.Data
+namespace TriangleNet.Topology
 {
     using System;
     using TriangleNet.Geometry;
diff --git a/Triangle.NET/Triangle/Data/Otri.cs b/Triangle.NET/Triangle/Topology/Otri.cs
similarity index 96%
rename from Triangle.NET/Triangle/Data/Otri.cs
rename to Triangle.NET/Triangle/Topology/Otri.cs
index 335c0c5..7e73a36 100644
--- a/Triangle.NET/Triangle/Data/Otri.cs
+++ b/Triangle.NET/Triangle/Topology/Otri.cs
@@ -5,7 +5,7 @@
 // </copyright>
 // -----------------------------------------------------------------------
 
-namespace TriangleNet.Data
+namespace TriangleNet.Topology
 {
     using System;
     using TriangleNet.Geometry;
diff --git a/Triangle.NET/Triangle/Data/Segment.cs b/Triangle.NET/Triangle/Topology/Segment.cs
similarity index 93%
rename from Triangle.NET/Triangle/Data/Segment.cs
rename to Triangle.NET/Triangle/Topology/Segment.cs
index 85f8155..5df1cce 100644
--- a/Triangle.NET/Triangle/Data/Segment.cs
+++ b/Triangle.NET/Triangle/Topology/Segment.cs
@@ -5,7 +5,7 @@
 // </copyright>
 // -----------------------------------------------------------------------
 
-namespace TriangleNet.Data
+namespace TriangleNet.Topology
 {
     using System;
     using TriangleNet.Geometry;
@@ -21,7 +21,7 @@ namespace TriangleNet.Data
         // triangle side or subsegment end that isn't attached to a real
         // subsegment.
 
-        internal static Segment Empty;
+        internal static readonly Segment Empty;
 
         static Segment()
         {
@@ -34,8 +34,6 @@ namespace TriangleNet.Data
             // can legally be dereferenced.
             Empty.subsegs[0].seg = Empty;
             Empty.subsegs[1].seg = Empty;
-
-            Triangle.Initialize();
         }
 
         #endregion
diff --git a/Triangle.NET/Triangle/Data/Triangle.cs b/Triangle.NET/Triangle/Topology/Triangle.cs
similarity index 91%
rename from Triangle.NET/Triangle/Data/Triangle.cs
rename to Triangle.NET/Triangle/Topology/Triangle.cs
index 7f4d04a..9e42182 100644
--- a/Triangle.NET/Triangle/Data/Triangle.cs
+++ b/Triangle.NET/Triangle/Topology/Triangle.cs
@@ -5,7 +5,7 @@
 // </copyright>
 // -----------------------------------------------------------------------
 
-namespace TriangleNet.Data
+namespace TriangleNet.Topology
 {
     using System;
     using TriangleNet.Geometry;
@@ -36,18 +36,16 @@ namespace TriangleNet.Data
 
         internal const int EmptyID = -1;
 
-        internal static Triangle Empty;
+        internal static readonly Triangle Empty;
 
         /// <summary>
-        /// Initializes the dummytri (Triangle.Empty). The method is called by the static Segment
-        /// constructor (which ensures that dummysub (Segment.Empty) will not be null).
+        /// Initializes the dummytri (Triangle.Empty).
         /// </summary>
-        internal static void Initialize()
+        static Triangle()
         {
             // Set up 'dummytri', the 'triangle' that occupies "outer space."
             Empty = new Triangle();
-            Empty.hash = EmptyID;
-            Empty.id = EmptyID;
+            Empty.hash = Empty.id = EmptyID;
 
             // Initialize the three adjoining triangles to be "outer space." These
             // will eventually be changed by various bonding operations, but their
@@ -57,6 +55,12 @@ namespace TriangleNet.Data
             Empty.neighbors[1].triangle = Empty;
             Empty.neighbors[2].triangle = Empty;
 
+            if (Segment.Empty == null)
+            {
+                // In case the static Segment constructor hasn't been called yet.
+                Empty.subsegs[0].seg = new Segment();
+            }
+
             // Initialize the three adjoining subsegments of 'dummytri' to be
             // the omnipresent subsegment.
             Empty.subsegs[0].seg = Segment.Empty;
diff --git a/Triangle.NET/Triangle/Triangle.csproj b/Triangle.NET/Triangle/Triangle.csproj
index 66f05a3..2e1f77c 100644
--- a/Triangle.NET/Triangle/Triangle.csproj
+++ b/Triangle.NET/Triangle/Triangle.csproj
@@ -43,7 +43,7 @@
   <ItemGroup>
     <Compile Include="Geometry\IEdge.cs" />
     <Compile Include="Geometry\IPolygon.cs" />
-    <Compile Include="Geometry\IPolygonExtensions.cs" />
+    <Compile Include="Geometry\ExtensionMethods.cs" />
     <Compile Include="Geometry\Polygon.cs" />
     <Compile Include="IO\FileProcessor.cs" />
     <Compile Include="IO\IFileFormat.cs" />
@@ -54,15 +54,16 @@
     <Compile Include="Meshing\IMesh.cs" />
     <Compile Include="Meshing\IQualityMesher.cs" />
     <Compile Include="Meshing\ITriangulator.cs" />
-    <Compile Include="Data\BadTriQueue.cs" />
+    <Compile Include="Meshing\Data\BadTriQueue.cs" />
     <Compile Include="Behavior.cs" />
     <Compile Include="Meshing\ConstraintMesher.cs" />
-    <Compile Include="Data\BadSubseg.cs" />
-    <Compile Include="Data\BadTriangle.cs" />
-    <Compile Include="Data\Osub.cs" />
-    <Compile Include="Data\Otri.cs" />
-    <Compile Include="Data\Segment.cs" />
-    <Compile Include="Data\Triangle.cs" />
+    <Compile Include="Meshing\Data\BadSubseg.cs" />
+    <Compile Include="Meshing\Data\BadTriangle.cs" />
+    <Compile Include="Topology\DCEL\DcelMesh.cs" />
+    <Compile Include="Topology\Osub.cs" />
+    <Compile Include="Topology\Otri.cs" />
+    <Compile Include="Topology\Segment.cs" />
+    <Compile Include="Topology\Triangle.cs" />
     <Compile Include="Geometry\Vertex.cs" />
     <Compile Include="Meshing\Algorithm\Dwyer.cs" />
     <Compile Include="Geometry\Rectangle.cs" />
@@ -109,13 +110,16 @@
     <Compile Include="Voronoi\Legacy\VoronoiRegion.cs" />
     <Compile Include="TriangleLocator.cs" />
     <Compile Include="Voronoi\BoundedVoronoi.cs" />
-    <Compile Include="Voronoi\DCEL\Face.cs" />
-    <Compile Include="Voronoi\DCEL\HalfEdge.cs" />
-    <Compile Include="Voronoi\DCEL\Vertex.cs" />
+    <Compile Include="Topology\DCEL\Face.cs" />
+    <Compile Include="Topology\DCEL\HalfEdge.cs" />
+    <Compile Include="Topology\DCEL\Vertex.cs" />
     <Compile Include="Voronoi\StandardVoronoi.cs" />
     <Compile Include="Voronoi\VoronoiBase.cs" />
   </ItemGroup>
-  <ItemGroup />
+  <ItemGroup>
+    <Folder Include="Data\" />
+    <Folder Include="Voronoi\DCEL\" />
+  </ItemGroup>
   <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
   <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
        Other similar extension points exist, see Microsoft.Common.targets.
diff --git a/Triangle.NET/Triangle/TriangleLocator.cs b/Triangle.NET/Triangle/TriangleLocator.cs
index cafb6df..3ef6854 100644
--- a/Triangle.NET/Triangle/TriangleLocator.cs
+++ b/Triangle.NET/Triangle/TriangleLocator.cs
@@ -7,7 +7,7 @@
 
 namespace TriangleNet
 {
-    using TriangleNet.Data;
+    using TriangleNet.Topology;
     using TriangleNet.Geometry;
 
     /// <summary>
diff --git a/Triangle.NET/Triangle/Voronoi/BoundedVoronoi.cs b/Triangle.NET/Triangle/Voronoi/BoundedVoronoi.cs
index f7cb81f..a25b411 100644
--- a/Triangle.NET/Triangle/Voronoi/BoundedVoronoi.cs
+++ b/Triangle.NET/Triangle/Voronoi/BoundedVoronoi.cs
@@ -6,9 +6,12 @@
 
 namespace TriangleNet.Voronoi
 {
-    using System;
     using System.Collections.Generic;
     using TriangleNet.Geometry;
+    using TriangleNet.Topology.DCEL;
+
+    using HVertex = TriangleNet.Topology.DCEL.Vertex;
+    using TVertex = TriangleNet.Geometry.Vertex;
 
     public class BoundedVoronoi : VoronoiBase
     {
@@ -19,26 +22,23 @@ namespace TriangleNet.Voronoi
         {
             // We explicitly told the base constructor to call the Generate method, so
             // at this point the basic Voronoi diagram is already created.
-            offset = base.vertices.Length;
+            offset = base.vertices.Count;
 
             // Each vertex of the hull will be part of a Voronoi cell.
-            Array.Resize(ref base.vertices, offset + mesh.hullsize);
+            base.vertices.Capacity = offset + mesh.hullsize;
 
             // Create bounded Voronoi diagram.
             PostProcess();
 
-            Array.Resize(ref base.vertices, offset);
+            ResolveBoundaryEdges();
         }
 
+        /// <summary>
+        /// Computes edge intersections with mesh boundary edges.
+        /// </summary>
         private void PostProcess()
         {
-            // Compute edge intersections with mesh boundary edges.
-            ProcessBoundaryEdges();
-        }
-
-        private void ProcessBoundaryEdges()
-        {
-            var infEdges = new List<DCEL.HalfEdge>();
+            var infEdges = new List<HalfEdge>();
 
             // TODO: save the half-infinite boundary edge in base class
             // so we don't have to process the complete list here.
@@ -52,8 +52,8 @@ namespace TriangleNet.Voronoi
 
             foreach (var edge in infEdges)
             {
-                var v1 = (Vertex)edge.face.generator;
-                var v2 = (Vertex)edge.twin.face.generator;
+                var v1 = (TVertex)edge.face.generator;
+                var v2 = (TVertex)edge.twin.face.generator;
 
                 double dir = RobustPredicates.CounterClockwise(v1, v2, edge.origin);
 
@@ -68,7 +68,7 @@ namespace TriangleNet.Voronoi
             }
         }
 
-        private void HandleCase1(DCEL.HalfEdge edge, Vertex v1, Vertex v2)
+        private void HandleCase1(HalfEdge edge, TVertex v1, TVertex v2)
         {
             //int mark = GetBoundaryMark(v1);
 
@@ -81,10 +81,10 @@ namespace TriangleNet.Voronoi
             v.y = (v1.y + v2.y) / 2.0;
 
             // Close the cell connected to edge.
-            var gen = new DCEL.Vertex(v1.x, v1.y);
+            var gen = new HVertex(v1.x, v1.y);
 
-            var h1 = new DCEL.HalfEdge(edge.twin.origin, edge.face);
-            var h2 = new DCEL.HalfEdge(gen, edge.face);
+            var h1 = new HalfEdge(edge.twin.origin, edge.face);
+            var h2 = new HalfEdge(gen, edge.face);
 
             h1.next = h2;
             h2.next = edge.face.edge;
@@ -100,49 +100,50 @@ namespace TriangleNet.Voronoi
             h1.id = count;
             h2.id = count + 1;
 
-            base.vertices[offset] = gen;
             gen.id = offset++;
+            base.vertices.Add(gen);
         }
 
-        private void HandleCase2(DCEL.HalfEdge e1, Vertex v1, Vertex v2)
+        private void HandleCase2(HalfEdge edge, TVertex v1, TVertex v2)
         {
-            var e2 = e1.twin.next;
-            var ei = e2.twin.next;
-
             // The vertices of the infinite edge.
-            var p1 = (Point)e1.origin;
-            var pi = (Point)e1.twin.origin;
+            var p1 = (Point)edge.origin;
+            var p2 = (Point)edge.twin.origin;
+
+            // The two edges leaving p1, pointing into the mesh.
+            var e1 = edge.twin.next;
+            var e2 = e1.twin.next;
 
             // Find the two intersections with boundary edge.
-            IntersectSegments(v1, v2, e2.origin, e2.twin.origin, ref pi);
-            IntersectSegments(v1, v2, ei.origin, ei.twin.origin, ref p1);
+            IntersectSegments(v1, v2, e1.origin, e1.twin.origin, ref p2);
+            IntersectSegments(v1, v2, e2.origin, e2.twin.origin, ref p1);
 
             // The infinite edge will now lie on the boundary. Update pointers:
-            e2.twin.next = e1.twin;
-            e1.twin.next = ei;
-            e1.twin.face = ei.face;
+            e1.twin.next = edge.twin;
+            edge.twin.next = e2;
+            edge.twin.face = e2.face;
 
-            e2.origin = e1.twin.origin;
+            e1.origin = edge.twin.origin;
 
-            e1.twin.twin = null;
-            e1.twin = null;
+            edge.twin.twin = null;
+            edge.twin = null;
 
             // Close the cell.
-            var gen = new DCEL.Vertex(v1.x, v1.y);
-            var he = new DCEL.HalfEdge(gen, e1.face);
+            var gen = new HVertex(v1.x, v1.y);
+            var he = new HalfEdge(gen, edge.face);
 
-            e1.next = he;
-            he.next = e1.face.edge;
+            edge.next = he;
+            he.next = edge.face.edge;
 
             // Let the face edge point to the edge leaving at generator.
-            e1.face.edge = he;
+            edge.face.edge = he;
 
             base.edges.Add(he);
 
             he.id = base.edges.Count;
 
-            base.vertices[offset] = gen;
             gen.id = offset++;
+            base.vertices.Add(gen);
         }
 
         /*
diff --git a/Triangle.NET/Triangle/Voronoi/Legacy/BoundedVoronoiLegacy.cs b/Triangle.NET/Triangle/Voronoi/Legacy/BoundedVoronoiLegacy.cs
index 537d6fa..7eccbbc 100644
--- a/Triangle.NET/Triangle/Voronoi/Legacy/BoundedVoronoiLegacy.cs
+++ b/Triangle.NET/Triangle/Voronoi/Legacy/BoundedVoronoiLegacy.cs
@@ -8,7 +8,7 @@ namespace TriangleNet.Voronoi.Legacy
 {
     using System;
     using System.Collections.Generic;
-    using TriangleNet.Data;
+    using TriangleNet.Topology;
     using TriangleNet.Geometry;
 
     /// <summary>
@@ -18,6 +18,7 @@ namespace TriangleNet.Voronoi.Legacy
     /// 2D Centroidal Voronoi Tessellations with Constraints, 2010,
     /// Jane Tournois, Pierre Alliez and Olivier Devillers
     /// </remarks>
+    [Obsolete("Use TriangleNet.Voronoi.BoundedVoronoi class instead.")]
     public class BoundedVoronoiLegacy : IVoronoi
     {
         Mesh mesh;
diff --git a/Triangle.NET/Triangle/Voronoi/Legacy/SimpleVoronoi.cs b/Triangle.NET/Triangle/Voronoi/Legacy/SimpleVoronoi.cs
index db44144..b289f88 100644
--- a/Triangle.NET/Triangle/Voronoi/Legacy/SimpleVoronoi.cs
+++ b/Triangle.NET/Triangle/Voronoi/Legacy/SimpleVoronoi.cs
@@ -9,12 +9,13 @@ namespace TriangleNet.Voronoi.Legacy
 {
     using System;
     using System.Collections.Generic;
-    using TriangleNet.Data;
+    using TriangleNet.Topology;
     using TriangleNet.Geometry;
 
     /// <summary>
     /// The Voronoi Diagram is the dual of a pointset triangulation.
     /// </summary>
+    [Obsolete("Use TriangleNet.Voronoi.StandardVoronoi class instead.")]
     public class SimpleVoronoi : IVoronoi
     {
         Mesh mesh;
diff --git a/Triangle.NET/Triangle/Voronoi/Legacy/VoronoiRegion.cs b/Triangle.NET/Triangle/Voronoi/Legacy/VoronoiRegion.cs
index d172d82..8d8f9e7 100644
--- a/Triangle.NET/Triangle/Voronoi/Legacy/VoronoiRegion.cs
+++ b/Triangle.NET/Triangle/Voronoi/Legacy/VoronoiRegion.cs
@@ -8,7 +8,7 @@ namespace TriangleNet.Voronoi.Legacy
 {
     using System;
     using System.Collections.Generic;
-    using TriangleNet.Data;
+    using TriangleNet.Topology;
     using TriangleNet.Geometry;
 
     /// <summary>
diff --git a/Triangle.NET/Triangle/Voronoi/VoronoiBase.cs b/Triangle.NET/Triangle/Voronoi/VoronoiBase.cs
index 5712174..b21fb93 100644
--- a/Triangle.NET/Triangle/Voronoi/VoronoiBase.cs
+++ b/Triangle.NET/Triangle/Voronoi/VoronoiBase.cs
@@ -9,53 +9,17 @@ namespace TriangleNet.Voronoi
 {
     using System.Collections.Generic;
 
-    using TriangleNet.Data;
+    using TriangleNet.Topology;
     using TriangleNet.Geometry;
-    using TriangleNet.Voronoi.DCEL;
+    using TriangleNet.Topology.DCEL;
 
-    using Vertex = TriangleNet.Voronoi.DCEL.Vertex;
+    using Vertex = TriangleNet.Topology.DCEL.Vertex;
 
     /// <summary>
     /// The Voronoi diagram is the dual of a pointset triangulation.
     /// </summary>
-    public abstract class VoronoiBase
+    public abstract class VoronoiBase : DcelMesh
     {
-        protected Vertex[] vertices;
-        protected List<HalfEdge> edges;
-        protected Face[] faces;
-
-        /// <summary>
-        /// Gets the vertices of the Voronoi diagram.
-        /// </summary>
-        public Vertex[] Vertices
-        {
-            get { return vertices; }
-        }
-
-        /// <summary>
-        /// Gets the list of half-edges specify the Voronoi diagram topology.
-        /// </summary>
-        public List<HalfEdge> HalfEdges
-        {
-            get { return edges; }
-        }
-
-        /// <summary>
-        /// Gets the faces of the Voronoi diagram.
-        /// </summary>
-        public Face[] Faces
-        {
-            get { return faces; }
-        }
-
-        /// <summary>
-        /// Gets the collection of edges of the Voronoi diagram.
-        /// </summary>
-        public IEnumerable<IEdge> Edges
-        {
-            get { return EnumerateEdges(); }
-        }
-
         /// <summary>
         /// Initializes a new instance of the <see cref="VoronoiBase" /> class.
         /// </summary>
@@ -63,6 +27,7 @@ namespace TriangleNet.Voronoi
         /// <param name="generate">If set to true, the constuctor will call the Generate
         /// method, which builds the Voronoi diagram.</param>
         protected VoronoiBase(Mesh mesh, bool generate)
+            : base(false)
         {
             if (generate)
             {
@@ -79,13 +44,14 @@ namespace TriangleNet.Voronoi
             mesh.Renumber();
             mesh.MakeVertexMap();
 
+            base.edges = new List<HalfEdge>();
+
             // Allocate space for voronoi diagram
-            this.vertices = new Vertex[mesh.triangles.Count + mesh.hullsize];
-            this.faces = new Face[mesh.vertices.Count];
-            this.edges = new List<HalfEdge>();
+            var vertices = new Vertex[mesh.triangles.Count + mesh.hullsize];
+            var faces = new Face[mesh.vertices.Count];
 
             // Compute triangles circumcenters and setup bounding box
-            var map = ComputeVertices(mesh);
+            var map = ComputeVertices(mesh, vertices);
 
             // Create all Voronoi faces.
             foreach (var vertex in mesh.vertices.Values)
@@ -93,17 +59,20 @@ namespace TriangleNet.Voronoi
                 faces[vertex.id] = new Face(vertex);
             }
 
-            ComputeEdges(mesh, map);
+            ComputeEdges(mesh, vertices, faces, map);
 
             // At this point all edges are computed, but the (edge.next) pointers aren't set.
             ConnectEdges(map);
+
+            base.vertices = new List<Vertex>(vertices);
+            base.faces = new List<Face>(faces);
         }
 
         /// <summary>
         /// Compute the Voronoi vertices (the circumcenters of the triangles).
         /// </summary>
         /// <returns>An empty map, which will map all vertices to a list of leaving edges.</returns>
-        protected List<HalfEdge>[] ComputeVertices(Mesh mesh)
+        protected List<HalfEdge>[] ComputeVertices(Mesh mesh, Vertex[] vertices)
         {
             Otri tri = default(Otri);
             double xi = 0, eta = 0;
@@ -136,7 +105,7 @@ namespace TriangleNet.Voronoi
         /// Compute the edges of the Voronoi diagram.
         /// </summary>
         /// <param name="map">Empty vertex map.</param>
-        protected void ComputeEdges(Mesh mesh, List<HalfEdge>[] map)
+        protected void ComputeEdges(Mesh mesh, Vertex[] vertices, Face[] faces, List<HalfEdge>[] map)
         {
             Otri tri, neighbor = default(Otri);
             TriangleNet.Geometry.Vertex org, dest;
@@ -269,23 +238,5 @@ namespace TriangleNet.Voronoi
                 }
             }
         }
-
-        protected virtual IEnumerable<IEdge> EnumerateEdges()
-        {
-            var edges = new List<IEdge>(this.edges.Count / 2);
-
-            foreach (var edge in this.edges)
-            {
-                var twin = edge.twin;
-
-                // Report edge only once.
-                if (edge.id < twin.id)
-                {
-                    edges.Add(new Edge(edge.origin.id, twin.origin.id));
-                }
-            }
-
-            return edges;
-        }
     }
 }