Added some tests for known expected interpolation positions.

OSCADSharp/OSCADSharp.ConsoleTests/Program.cs

@@ -13,7 +13,7 @@ namespace OSCADSharp.ConsoleTests
     {
         static void Main(string[] args)
         {
-            var cube = new Cube(50, 50, 50, true).Translate(30, 30, 30).Rotate(25, 45, -90);
+            var cube = new Cube(13, 13, 13).Rotate(90, 37.5, -180);
 
             var pos = cube.Position();
             var cyl1 = new Cylinder(1, 100, true).Translate(pos);

OSCADSharp/OSCADSharp.UnitTests/InterpolationTests.cs

@@ -0,0 +1,119 @@
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+using OSCADSharp.Solids;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace OSCADSharp.UnitTests
+{
+    [TestClass]
+    public class InterpolationTests
+    {
+        //Positive X rotation
+        [TestMethod]
+        public void Interpolation_RotateOnXAxis()
+        {
+            var cube = new Cube(9, 9, 9).Rotate(90, 0, 0);
+            
+            //Rotating on X axis by 90 should shift the center of the cube on the negative Y quadrant
+            Assert.AreEqual(new Vector3(4.5, -4.5, 4.5), cube.Position());
+        }
+
+        //Negative X rotation
+        [TestMethod]
+        public void Interpolation_NegativeRotationOnXAxis()
+        {
+            var cube = new Cube(11, 11, 11).Rotate(-90, 0, 0);
+
+            //Rotating on X axis by -90 should shift the center of the cube on the negative Z quadrant
+            Assert.AreEqual(new Vector3(5.5, 5.5, -5.5), cube.Position());
+        }
+
+        //Y Rotation
+        [TestMethod]
+        public void Interpolation_PositiveYRotationWithTallCube()
+        {
+            var cube = new Cube(10, 12, 23).Rotate(0, 90, 0);
+
+            //Rotating on Y axis by 90 should shift the center of the cube on the negative Z quadrant
+            Assert.AreEqual(new Vector3(11.5, 6, -5), cube.Position());
+        }
+
+        //Negative Y rotation
+        [TestMethod]
+        public void Interpolation_NegativeYRotationWithWideCube()
+        {
+            var cube = new Cube(10, 30, 15).Rotate(0, -90, 0);
+
+            //Rotating on Y axis by -90 should shift the center of the cube on the negative X quadrant
+            Assert.AreEqual(new Vector3(-7.5, 15, 5), cube.Position());
+        }
+
+        //Z Rotation
+        [TestMethod]
+        public void Interpolation_ZRotationWithLongCube()
+        {
+            var cube = new Cube(10, 5, 2).Rotate(0, 0, 115);
+
+            //Rotating on Z axis by 90 should shift the center of the cube on the negative X quadrant
+            Assert.AreEqual(new Vector3(-4.37886077629512, 3.4749932808315, 1), cube.Position());
+        }
+
+        //Negative Z rotation
+        [TestMethod]
+        public void Interpolation_NegativeZRotation()
+        {
+            var cube = new Cube(10, 5, 2).Rotate(0, 0, -95);
+
+            //Rotating on Z axis by 90 should shift the center of the cube on the negative Y quadrant
+            Assert.AreEqual(new Vector3(2.05470803149107, -5.19886284732787, 1), cube.Position());
+        }
+
+        //Centered rotation (no change)
+        [TestMethod]
+        public void Interpolation_CenteredCubePositionNotUpdatedWhenRotated()
+        {
+            var cube = new Cube(5, 20, 20, true).Rotate(15, -120, 270);
+
+            Assert.AreEqual(new Vector3(), cube.Position());
+        }
+
+        //X and Y rotation
+        [TestMethod]
+        public void Interpolation_XAndYRotation()
+        {
+            var cube = new Cube(5, 5, 5).Rotate(120, 45, 0);
+
+            Assert.AreEqual(new Vector3(2.41481456572267, -3.4150635094611, -1.12071934021007), cube.Position());
+        }
+
+        //Y and Z rotation
+        [TestMethod]
+        public void Interpolation_YandZRotation()
+        {
+            var cube = new Cube(13, 13, 13).Rotate(0, 270, -35);
+
+            Assert.AreEqual(new Vector3(-1.59624145159665, 9.05273512416025, 6.5), cube.Position());
+        }
+
+        //X and Z rotation
+        [TestMethod]
+        public void Interpolation_XandZRotation()
+        {
+            var cube = new Cube(13, 13, 13).Rotate(-145, 0, 190);
+
+            Assert.AreEqual(new Vector3(-6.67843481376553, 0.443277802376793, -9.05273512416025), cube.Position());
+        }
+
+        //X, Y and Z rotation
+        [TestMethod]
+        public void Interpolation_XYZRotation()
+        {
+            var cube = new Cube(13, 13, 13).Rotate(90, 37.5, -180);
+
+            Assert.AreEqual(new Vector3(-9.11374600044971, 6.5, 1.19984742333634), cube.Position());
+        }
+    }
+}

OSCADSharp/OSCADSharp.UnitTests/OSCADSharp.UnitTests.csproj

@@ -55,6 +55,7 @@
     <Compile Include="CubeTests.cs" />
     <Compile Include="CylinderTests.cs" />
     <Compile Include="HullTests.cs" />
+    <Compile Include="InterpolationTests.cs" />
     <Compile Include="OSCADObjectTests.cs" />
     <Compile Include="SphereTests.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />