Audio/AudioDevice: Improve GetListenerRotation

include/Nazara/Audio/AudioDevice.hpp

@@ -35,7 +35,7 @@ namespace Nz
 			virtual float GetGlobalVolume() const = 0;
 			virtual Vector3f GetListenerDirection(Vector3f* up = nullptr) const = 0;
 			virtual Vector3f GetListenerPosition() const = 0;
-			virtual Quaternionf GetListenerRotation(Vector3f* up = nullptr) const = 0;
+			virtual Quaternionf GetListenerRotation() const = 0;
 			virtual Vector3f GetListenerVelocity() const = 0;
 			virtual float GetSpeedOfSound() const = 0;
 

include/Nazara/Math/Angle.hpp

@@ -55,6 +55,9 @@ namespace Nz
 
 			constexpr Angle& operator=(const Angle&) = default;
 
+			constexpr const Angle& operator+() const;
+			constexpr Angle operator-() const;
+
 			constexpr Angle operator+(const Angle& other) const;
 			constexpr Angle operator-(const Angle& other) const;
 			constexpr Angle operator*(T scalar) const;

include/Nazara/Math/Angle.inl

@@ -381,6 +381,27 @@ namespace Nz
 		return ToRadianAngle();
 	}*/
 
+
+	/*!
+	* \brief Helps to represent the sign of the angle
+	* \return A constant reference to this angle
+	*/
+	template<AngleUnit Unit, typename T>
+	constexpr const Angle<Unit, T>& Angle<Unit, T>::operator+() const
+	{
+		return *this;
+	}
+
+	/*!
+	* \brief Negates the angle
+	* \return An angle with a negated value
+	*/
+	template<AngleUnit Unit, typename T>
+	constexpr Angle<Unit, T> Angle<Unit, T>::operator-() const
+	{
+		return Angle(-value);
+	}
+
 	/*!
 	* \brief Addition operator
 	* \return Adds two angles together

include/Nazara/Math/Quaternion.hpp

@@ -83,6 +83,7 @@ namespace Nz
 
 			static Quaternion Identity();
 			static Quaternion Lerp(const Quaternion& from, const Quaternion& to, T interpolation);
+			static Quaternion LookAt(const Vector3<T>& forward, const Vector3<T>& up);
 			static Quaternion Normalize(const Quaternion& quat, T* length = nullptr);
 			static Quaternion RotationBetween(const Vector3<T>& from, const Vector3<T>& to);
 			static Quaternion Slerp(const Quaternion& from, const Quaternion& to, T interpolation);

include/Nazara/Math/Quaternion.inl

@@ -705,7 +705,6 @@ namespace Nz
 	*
 	* \see Lerp, Slerp
 	*/
-
 	template<typename T>
 	Quaternion<T> Quaternion<T>::Lerp(const Quaternion& from, const Quaternion& to, T interpolation)
 	{
@@ -726,6 +725,33 @@ namespace Nz
 		return interpolated;
 	}
 
+	template<typename T>
+	Quaternion<T> Quaternion<T>::LookAt(const Vector3<T>& forward, const Vector3<T>& up)
+	{
+		// From https://gamedev.stackexchange.com/questions/53129/quaternion-look-at-with-up-vector
+
+		Vector3<T> forward_w(1, 0, 0);
+		Vector3<T> axis = Vector3<T>::CrossProduct(forward, forward_w);
+		RadianAngle<T> angle = std::acos(Vector3<T>::DotProduct(forward, forward_w));
+
+		Vector3<T> third = Vector3<T>::CrossProduct(axis, forward_w);
+		if (Vector3<T>::DotProduct(third, forward) < 0)
+			angle = -angle;
+
+		Quaternion<T> q1 = Quaternion(angle, axis);
+
+		Vector3<T> up_l = q1 * up;
+		Vector3<T> right = Vector3<T>::Normalize(Vector3<T>::CrossProduct(forward, up));
+		Vector3<T> up_w = Vector3<T>::Normalize(Vector3<T>::CrossProduct(right, forward));
+
+		Vector3<T> axis2 = Vector3<T>::CrossProduct(up_l, up_w);
+		RadianAngle<T> angle2 = std::acos(Vector3<T>::DotProduct(forward, forward_w));
+
+		Quaternion<T> q2 = Quaternion(angle2, axis2);
+
+		return q2 * q1;
+	}
+
 	/*!
 	* \brief Gives the normalized quaternion
 	* \return A normalized quaternion from the quat

src/Nazara/Audio/OpenALDevice.cpp

@@ -157,7 +157,7 @@ namespace Nz
 	*
 	* \see GetListenerDirection
 	*/
-	Quaternionf OpenALDevice::GetListenerRotation(Vector3f* up) const
+	Quaternionf OpenALDevice::GetListenerRotation() const
 	{
 		MakeContextCurrent();
 
@@ -165,11 +165,9 @@ namespace Nz
 		m_library.alGetListenerfv(AL_ORIENTATION, orientation);
 
 		Vector3f forward(orientation[0], orientation[1], orientation[2]);
+		Vector3f up(orientation[3], orientation[4], orientation[5]);
 
-		if (up)
-			up->Set(orientation[3], orientation[4], orientation[5]);
-
-		return Quaternionf::RotationBetween(Vector3f::Forward(), forward);
+		return Quaternionf::LookAt(forward, up);
 	}
 
 	/*!