Add Polygon tests.

src/Triangle.Tests/Geomerty/PolygonTest.cs

@@ -0,0 +1,76 @@
+using NUnit.Framework;
+using TriangleNet.Geometry;
+
+namespace TriangleNet.Tests.Geometry
+{
+    public class PolygonTest
+    {
+        // The vertices  that define the polygon contour (triangle shape).
+        Vertex[] vertices = new Vertex[]
+        {
+                new Vertex(0d, 0d),
+                new Vertex(2d ,0d),
+                new Vertex(1d, 1.5)
+        };
+
+        [Test]
+        public void TestAddContour()
+        {
+            var contour = new Contour(vertices);
+
+            var p = new Polygon();
+
+            p.Add(contour);
+
+            Assert.AreEqual(3, p.Points.Count);
+            Assert.AreEqual(3, p.Segments.Count);
+            Assert.AreEqual(0, p.Holes.Count);
+            Assert.AreEqual(0, p.Regions.Count);
+        }
+
+        [Test]
+        public void TestAddContourAsHole()
+        {
+            var contour = new Contour(vertices);
+
+            var p = new Polygon();
+
+            p.Add(contour, true);
+
+            Assert.AreEqual(3, p.Points.Count);
+            Assert.AreEqual(3, p.Segments.Count);
+            Assert.AreEqual(1, p.Holes.Count);
+            Assert.AreEqual(0, p.Regions.Count);
+        }
+
+        [Test]
+        public void TestAddContourAsRegion()
+        {
+            var contour = new Contour(vertices, 1);
+
+            var p = new Polygon();
+
+            p.Add(contour, 1);
+
+            Assert.AreEqual(3, p.Points.Count);
+            Assert.AreEqual(3, p.Segments.Count);
+            Assert.AreEqual(0, p.Holes.Count);
+            Assert.AreEqual(1, p.Regions.Count);
+        }
+
+        [Test]
+        public void TestBounds()
+        {
+            var contour = new Contour(vertices);
+
+            var p = new Polygon();
+
+            p.Add(contour);
+
+            var bounds = p.Bounds();
+
+            Assert.AreEqual(2d, bounds.Width);
+            Assert.AreEqual(1.5, bounds.Height);
+        }
+    }
+}

src/Triangle.Tests/Triangle.Tests.csproj

@@ -9,9 +9,9 @@
 
 
   <ItemGroup>
-    <PackageReference Include="nunit" Version="3.13.3" />
-    <PackageReference Include="NUnit3TestAdapter" Version="4.2.1" />
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.2.0" />
+    <PackageReference Include="NUnit" Version="3.13.3" />
+    <PackageReference Include="NUnit3TestAdapter" Version="4.3.0" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.4.0" />
   </ItemGroup>
 
   <ItemGroup>

src/Triangle/Tools/PolygonValidator.cs

@@ -121,14 +121,15 @@ namespace TriangleNet.Tools
         }
 
         /// <summary>
-        /// Get the ratio of the largest and smallest segment length.
+        /// Gets the minimum and maximum feature size (segment length) of the input polygon.
         /// </summary>
         /// <param name="poly">The polygon.</param>
-        /// <param name="threshold">The ratio threshold.</param>
+        /// <param name="threshold">The ratio threshold (smallest to largest segment length, default = 2e-10).</param>
         /// <remarks>
-        /// This method will also report zero-length segments.
+        /// This method will also report zero-length segments. The method does NOT detect
+        /// free vertices lying close to segments.
         /// </remarks>
-        public static double GetSegmentRatio(IPolygon poly, double threshold = 2e12)
+        public static (double min, double max) GetSegmentRatio(IPolygon poly, double threshold = 2e-10)
         {
             var logger = Log.Instance;
 
@@ -156,15 +157,15 @@ namespace TriangleNet.Tools
                 max = Math.Max(max, length);
             }
 
-            double ratio = max / min;
+            double ratio = min / max;
 
-            if (ratio > threshold)
+            if (ratio < threshold)
             {
-                logger.Warning(string.Format("Polygon has large segment ratio {0:G2}.", ratio),
+                logger.Warning(string.Format("Polygon has tiny segment ratio {0:G2}.", ratio),
                     "PolygonValidator.GetSegmentRatio()");
             }
 
-            return ratio;
+            return (min, max);
         }
 
         /// <summary>