Add Quaternion.cs

tools/core/math/Quaternion.cs

@@ -0,0 +1,33 @@
+/*
+ * Copyright (c) 2012-2016 Daniele Bartolini and individual contributors.
+ * License: https://github.com/taylor001/crown/blob/master/LICENSE
+ */
+
+using System;
+
+namespace Crown
+{
+	public struct Quaternion
+	{
+		public float x, y, z, w;
+
+		public Quaternion(float x, float y, float z, float w)
+		{
+			this.x = x;
+			this.y = y;
+			this.z = z;
+			this.w = w;
+		}
+
+		public Quaternion(Vector3 axis, float angle)
+		{
+			float ha = angle * 0.5f;
+			float sa = (float)Math.Sin(ha);
+			float ca = (float)Math.Cos(ha);
+			this.x = axis.x * sa;
+			this.y = axis.y * sa;
+			this.z = axis.z * sa;
+			this.w = ca;
+		}
+	}
+}