Update example 4 (related to issue #21)

src/Triangle.Examples/Examples/Example4.cs

@@ -6,6 +6,7 @@ namespace TriangleNet.Examples
     using TriangleNet.Meshing;
     using TriangleNet.Rendering.Text;
     using TriangleNet.Smoothing;
+    using TriangleNet.Tools;
 
     /// <summary>
     /// Triangulate a polygon with hole with maximum area constraint, followed by mesh smoothing.
@@ -17,15 +18,33 @@ namespace TriangleNet.Examples
             // Generate mesh.
             var mesh = CreateMesh();
 
-            if (print) SvgImage.Save(mesh, "example-4.svg", 500);
+            if (print)
+            {
+                // The ideal area if triangles were equilateral.
+                var area = Math.Sqrt(3) / 4 * h * h;
+
+                var quality = new QualityMeasure(mesh);
+
+                Console.WriteLine($"   Ideal area: {area}");
+                Console.WriteLine($"    Min. area: {quality.AreaMinimum}");
+                Console.WriteLine($"    Max. area: {quality.AreaMaximum}");
+
+                SvgImage.Save(mesh, "example-4.svg", 500);
+            }
 
             return mesh.Triangles.Count > 0;
         }
 
+        // The boundary segment size of the input geometry.
+        const double h = 0.2;
+
+        // Parameter to relax the maximum area constraint.
+        const double relax = 1.45;
+
         public static IMesh CreateMesh()
         {
             // Generate the input geometry.
-            var poly = Example3.CreatePolygon();
+            var poly = Example3.CreatePolygon(h);
 
             // Since we want to do CVT smoothing, ensure that the mesh
             // is conforming Delaunay.
@@ -35,9 +54,11 @@ namespace TriangleNet.Examples
             // angle, since smoothing will improve the triangle shapes).
             var quality = new QualityOptions()
             {
-                // The boundary segments have a length of 0.2, so we set a
-                // maximum area constraint assuming equilateral triangles.
-                MaximumArea = (Math.Sqrt(3) / 4 * 0.2 * 0.2) * 1.45
+                // Given the boundary segment size, we set a maximum
+                // area constraint assuming equilateral triangles. The
+                // relaxation parameter is chosen to reduce the deviation
+                // from this ideal value.
+                MaximumArea = (Math.Sqrt(3) / 4 * h * h) * relax
             };
 
             // Generate mesh using the polygons Triangulate extension method.

src/Triangle.Examples/Examples/Example8.cs

@@ -21,7 +21,7 @@ namespace TriangleNet.Examples
             // Generate the input geometry.
             poly.Add(Generate.Rectangle(0.0, 0.0, 1.0, 1.0));
 
-            // Set minimum angle quality option, ignoring holes.
+            // Set user test function.
             var quality = new QualityOptions()
             {
                 UserTest = MaxEdgeLength

src/Triangle.Examples/Program.cs

@@ -2,23 +2,26 @@
 namespace TriangleNet
 {
     using System;
+    using System.Linq;
     using TriangleNet.Examples;
 
     class Program
     {
         static void Main(string[] args)
         {
-            Check("Example  1", Example1.Run());
-            Check("Example  2", Example2.Run());
-            Check("Example  3", Example3.Run());
-            Check("Example  4", Example4.Run());
-            Check("Example  5", Example5.Run());
-            Check("Example  6", Example6.Run());
-            Check("Example  7", Example7.Run());
-            Check("Example  8", Example8.Run());
+            bool print = args.Contains("--print");
+
+            Check("Example  1", Example1.Run(print));
+            Check("Example  2", Example2.Run(print));
+            Check("Example  3", Example3.Run(print));
+            Check("Example  4", Example4.Run(print));
+            Check("Example  5", Example5.Run(print));
+            Check("Example  6", Example6.Run(print));
+            Check("Example  7", Example7.Run(print));
+            Check("Example  8", Example8.Run(print));
             Check("Example  9", Example9.Run());
-            Check("Example 10", Example10.Run());
-            Check("Example 11", Example11.Run());
+            Check("Example 10", Example10.Run(print));
+            Check("Example 11", Example11.Run(print));
         }
 
         static void Check(string item, bool success)