Added IsoSphere.cs which creates a sphere Shape using theta ad phi coordinates.

Source/Examples/Shapes/IsoSphere.cs

@@ -0,0 +1,54 @@
+#region --- License ---
+/* Copyright (c) 2006, 2007 Stefanos Apostolopoulos
+ * See license.txt for license info
+ */
+#endregion
+
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+using OpenTK.Math;
+
+namespace Examples.Shapes
+{
+    class IsoSphere : Shape
+    {
+        const double DoublePI = System.Math.PI * 2.0;
+
+        public IsoSphere(int s_steps, int t_steps, float x_scale, float y_scale, float z_scale)
+        {
+            int count = 4 * s_steps * t_steps ;
+            
+            Vertices = new Vector3[count];
+            Normals = new Vector3[count];
+            Texcoords = new Vector2[count];
+            Indices = new int[6 * count / 4];
+
+            int i = 0;
+            for (double t = -System.Math.PI; (float)t < (float)System.Math.PI - Single.Epsilon; t += System.Math.PI / (double)t_steps)
+            {
+                for (double s = 0.0; (float)s < (float)DoublePI; s += System.Math.PI / (double)s_steps)
+                {
+                    Vertices[i].X = x_scale * (float)(System.Math.Cos(s) * System.Math.Sin(t));
+                    Vertices[i].Y = y_scale * (float)(System.Math.Sin(s) * System.Math.Sin(t));
+                    Vertices[i].Z = z_scale * (float)System.Math.Cos(t);
+                    //vertices[i] = vertices[i].Scale(x_scale, y_scale, z_scale);
+                    Normals[i] = Vertices[i].Normalize();
+
+                    ++i;
+                }
+            }
+            
+            for (i = 0; i < 6*count/4; i+=6)
+            {
+                Indices[i] = i;
+                Indices[i + 1] = i + 1;
+                Indices[i + 2] = i + 2 * s_steps + 1;
+                Indices[i + 3] = i + 2 * s_steps;
+                Indices[i + 4] = i;
+                Indices[i + 5] = i + 2 * s_steps + 1;
+            }
+        }
+    }
+}