Continued Madgwick filter implementation

include/sta/math/quaternion.hpp

@@ -14,24 +14,60 @@ namespace sta
 		class Quaternion
 		{
 		public:
+			/**
+			 * @brief Construct a new Quaternion object
+			 * 
+			 * @param w 
+			 * @param x 
+			 * @param y 
+			 * @param z 
+			 */
 			Quaternion(float w, float x, float y, float z);
 
+			/**
+			 * @brief Construct a new Quaternion object
+			 * 
+			 */
 			Quaternion();
 
+			/**
+			 * @brief 
+			 * 
+			 * @param dt 
+			 * @param ox 
+			 * @param oy 
+			 * @param oz 
+			 * @return Quaternion 
+			 */
 			Quaternion integrate(float dt, float ox, float oy, float oz);
 
+			/**
+			 * @brief 
+			 * 
+			 * @return Quaternion 
+			 */
 			static Quaternion unit();
 
+			/**
+			 * @brief 
+			 * 
+			 * @return float 
+			 */
 			float norm();
 
+			/**
+			 * @brief 
+			 * 
+			 * @return Quaternion 
+			 */
 			Quaternion normalized();
 
-			Quaternion operator*(const Quaternion& quat);
-			Quaternion operator+(const Quaternion& quat);
-			
+			Quaternion conjugate();			
 		public:
 			float x, y, z, w;
 		};
+
+		Quaternion operator-(const Quaternion& q1, const Quaternion& q2);
 		Quaternion operator+(const Quaternion& q1, const Quaternion& q2);
 		Quaternion operator*(const Quaternion& q1, const Quaternion& q2);
 		Quaternion operator*(const Quaternion& quat, float scalar);