Add more tests.

src/Triangle.Tests/Geomerty/ContourTest.cs

@@ -0,0 +1,27 @@
+using NUnit.Framework;
+using TriangleNet.Geometry;
+
+namespace TriangleNet.Tests.Geometry
+{
+    public class ContourTest
+    {
+        [Test]
+        public void TestFindInteriorPoint()
+        {
+            // The vertices  that define the contour (have to be in order, obviously).
+            var vertices = new Vertex[]
+            {
+                new Vertex(0d, 0d),
+                new Vertex(1d ,0d),
+                new Vertex(1d, 1d),
+                new Vertex(0d, 1d),
+            };
+
+            var contour = new Contour(vertices);
+
+            var p = contour.FindInteriorPoint();
+
+            Assert.IsTrue(p.X > 0d && p.X < 1d && p.Y > 0d && p.Y < 1d);
+        }
+    }
+}

src/Triangle.Tests/Helper.cs

@@ -0,0 +1,35 @@
+
+namespace TriangleNet.Tests
+{
+    using System.Collections.Generic;
+    using TriangleNet.Geometry;
+    using TriangleNet.Topology;
+
+    static class Helper
+    {
+        public static Contour Rectangle(double left, double top,
+            double right, double bottom, int mark = 0)
+        {
+            var points = new List<Vertex>(4);
+
+            points.Add(new Vertex(left, top, mark));
+            points.Add(new Vertex(right, top, mark));
+            points.Add(new Vertex(right, bottom, mark));
+            points.Add(new Vertex(left, bottom, mark));
+
+            return new Contour(points, mark, true);
+        }
+
+        public static Triangle CreateTriangle(int id, Vertex org, Vertex dest, Vertex apex)
+        {
+            var t = new Triangle() { id = id, hash = id };
+
+            // Node ordering 'plus 1 mod 3'.
+            t.vertices[0] = apex;
+            t.vertices[1] = org;
+            t.vertices[2] = dest;
+
+            return t;
+        }
+    }
+}

src/Triangle.Tests/Meshing/Iterators/RegionIteratorTest.cs

@@ -0,0 +1,35 @@
+using NUnit.Framework;
+using TriangleNet.Geometry;
+using TriangleNet.Meshing.Iterators;
+using TriangleNet.Tools;
+using TriangleNet.Topology;
+
+namespace TriangleNet.Tests.Meshing.Iterators
+{
+    public class RegionIteratorTest
+    {
+        public void TestProcessRegionProtected()
+        {
+            var poly = new Polygon();
+
+            // Outer region.
+            poly.Add(Helper.Rectangle(-2d, 2d, 2d, -2d, 2));
+
+            // Inner region.
+            poly.Add(Helper.Rectangle(-1d, 1d, 1d, -1d, 1));
+
+            poly.Regions.Add(new RegionPointer(0d, 0d, 1));
+
+            var mesh = (Mesh)poly.Triangulate();
+
+            var iterator = new RegionIterator(mesh);
+
+            var qtree = new TriangleQuadTree(mesh);
+
+            // Find a seeding triangle in region 1.
+            var seed = (Triangle)qtree.Query(0.0, 0.0);
+
+            iterator.Process(seed, t => Assert.AreEqual(1, t.Label));
+        }
+    }
+}

src/Triangle.Tests/RobustPredicatesTest.cs

@@ -0,0 +1,55 @@
+using NUnit.Framework;
+using TriangleNet.Geometry;
+
+namespace TriangleNet.Tests
+{
+    public class RobustPredicatesTest
+    {
+        [Test]
+        public void TestCounterClockwise()
+        {
+            var robust = RobustPredicates.Default;
+
+            var a = new Point(-1d, 0d);
+            var b = new Point( 0d, 1d);
+
+            Assert.IsTrue(robust.CounterClockwise(a, b,  new Point(1d, 0d)) < 0d);
+            Assert.IsTrue(robust.CounterClockwise(a, b,  new Point(0d, 2d)) > 0d);
+            Assert.IsTrue(robust.CounterClockwise(a, b,  new Point(1d, 2d)) == 0d);
+        }
+
+        [Test]
+        public void TestInCircle()
+        {
+            var robust = RobustPredicates.Default;
+
+            var a = new Point(-1d, 0d);
+            var b = new Point(0d, 1d);
+            var c = new Point(1d, 0d);
+
+            Assert.IsTrue(robust.InCircle(a, b, c, new Point(0d, 0.5)) < 0d);
+            Assert.IsTrue(robust.InCircle(a, b, c, new Point(0d, 1.5)) > 0d);
+            Assert.IsTrue(robust.InCircle(a, b, c, new Point(0d, 1d)) == 0d);
+        }
+
+        [Test]
+        public void TestFindCircumcenter()
+        {
+            var robust = RobustPredicates.Default;
+
+            var a = new Point(-1d, 0d);
+            var b = new Point(0d, 1d);
+            var c = new Point(1d, 0d);
+
+            double xi = 0d, eta = 0d;
+
+            var actual = robust.FindCircumcenter(a, b, c, ref xi, ref eta);
+            var expected = new Point(0d, 0d);
+
+            Assert.AreEqual(expected.X, actual.X);
+            Assert.AreEqual(expected.Y, actual.Y);
+            Assert.AreEqual(0.0, xi);
+            Assert.AreEqual(0.5, eta);
+        }
+    }
+}

src/Triangle.Tests/Topology/OtriTest.cs

@@ -47,10 +47,10 @@ namespace TriangleNet.Tests
             //
             // This is because, for example, and oriented triange will return as its
             // origin (Org() method) the element at index [(orientation + 1) % 3].
-            var t0 = triangles[0] = CreateTriangle(0, vertices[0], vertices[1], vertices[3]);
-            var t1 = triangles[1] = CreateTriangle(1, vertices[1], vertices[4], vertices[3]);
-            var t2 = triangles[2] = CreateTriangle(2, vertices[1], vertices[2], vertices[4]);
-            var t3 = triangles[3] = CreateTriangle(3, vertices[3], vertices[4], vertices[5]);
+            var t0 = triangles[0] = Helper.CreateTriangle(0, vertices[0], vertices[1], vertices[3]);
+            var t1 = triangles[1] = Helper.CreateTriangle(1, vertices[1], vertices[4], vertices[3]);
+            var t2 = triangles[2] = Helper.CreateTriangle(2, vertices[1], vertices[2], vertices[4]);
+            var t3 = triangles[3] = Helper.CreateTriangle(3, vertices[3], vertices[4], vertices[5]);
 
             // Setup connectivity of triangle 0.
             t0.neighbors[0].tri = dummy;
@@ -81,18 +81,6 @@ namespace TriangleNet.Tests
             return triangles;
         }
 
-        private Triangle CreateTriangle(int id, Vertex org, Vertex dest, Vertex apex)
-        {
-            var t = new Triangle() { id = id, hash = id };
-
-            // Node ordering 'plus 1 mod 3'.
-            t.vertices[0] = apex;
-            t.vertices[1] = org;
-            t.vertices[2] = dest;
-
-            return t;
-        }
-
         [SetUp]
         public void Initialize()
         {
@@ -111,7 +99,7 @@ namespace TriangleNet.Tests
         {
             Otri t = default;
 
-            t.tri = CreateTriangle(0, vertices[1], vertices[4], vertices[3]);
+            t.tri = Helper.CreateTriangle(0, vertices[1], vertices[4], vertices[3]);
 
             t.orient = 0;
             Assert.AreEqual(1, t.Org().ID);
@@ -128,7 +116,7 @@ namespace TriangleNet.Tests
         {
             Otri t = default;
 
-            t.tri = CreateTriangle(0, vertices[1], vertices[4], vertices[3]);
+            t.tri = Helper.CreateTriangle(0, vertices[1], vertices[4], vertices[3]);
 
             t.orient = 0;
             Assert.AreEqual(4, t.Dest().ID);
@@ -145,7 +133,7 @@ namespace TriangleNet.Tests
         {
             Otri t = default;
 
-            t.tri = CreateTriangle(0, vertices[1], vertices[4], vertices[3]);
+            t.tri = Helper.CreateTriangle(0, vertices[1], vertices[4], vertices[3]);
 
             t.orient = 0;
             Assert.AreEqual(3, t.Apex().ID);
@@ -423,8 +411,8 @@ namespace TriangleNet.Tests
 
             Otri tmp = default;
 
-            s.tri = CreateTriangle(0, vertices[0], vertices[1], vertices[3]);
-            t.tri = CreateTriangle(1, vertices[1], vertices[4], vertices[3]);
+            s.tri = Helper.CreateTriangle(0, vertices[0], vertices[1], vertices[3]);
+            t.tri = Helper.CreateTriangle(1, vertices[1], vertices[4], vertices[3]);
 
             s.orient = 1; // Edge  1 -> 3.
             t.orient = 2; // Edge  3 -> 1.