/// @ref gtc_quaternion
/// @file glm/gtc/quaternion.hpp
///
/// @see core (dependence)
/// @see gtc_constants (dependence)
///
/// @defgroup gtc_quaternion GLM_GTC_quaternion
/// @ingroup gtc
///
/// Include <glm/gtc/quaternion.hpp> to use the features of this extension.
///
/// Defines a templated quaternion type and several quaternion operations.

#pragma once

// Dependency:
#include "../detail/type_mat3x3.hpp"
#include "../detail/type_mat4x4.hpp"
#include "../detail/type_vec3.hpp"
#include "../detail/type_vec4.hpp"
#include "../ext/vector_relational.hpp"
#include "../ext/quaternion_relational.hpp"
#include "../gtc/constants.hpp"
#include "../gtc/matrix_transform.hpp"

namespace glm
{
	/// @addtogroup gtc_quaternion
	/// @{

	template<typename T, qualifier Q>
	struct qua
	{
		// -- Implementation detail --

		typedef qua<T, Q> type;
		typedef T value_type;

		// -- Data --

#		if GLM_LANG & GLM_LANG_CXXMS_FLAG
			union
			{
				struct { T x, y, z, w;};

				typename detail::storage<4, T, detail::is_aligned<Q>::value>::type data;
			};
#		else
			T x, y, z, w;
#		endif

		// -- Component accesses --

		typedef length_t length_type;
		/// Return the count of components of a quaternion
		GLM_FUNC_DECL static GLM_CONSTEXPR length_type length(){return 4;}

		GLM_FUNC_DECL GLM_CONSTEXPR T & operator[](length_type i);
		GLM_FUNC_DECL GLM_CONSTEXPR T const& operator[](length_type i) const;

		// -- Implicit basic constructors --

		GLM_FUNC_DECL GLM_CONSTEXPR qua() GLM_DEFAULT;
		GLM_FUNC_DECL GLM_CONSTEXPR qua(qua<T, Q> const& q) GLM_DEFAULT;
		template<qualifier P>
		GLM_FUNC_DECL GLM_CONSTEXPR qua(qua<T, P> const& q);

		// -- Explicit basic constructors --

		GLM_FUNC_DECL GLM_CONSTEXPR qua(T s, vec<3, T, Q> const& v);
		GLM_FUNC_DECL GLM_CONSTEXPR qua(T w, T x, T y, T z);

		// -- Conversion constructors --

		template<typename U, qualifier P>
		GLM_FUNC_DECL GLM_CONSTEXPR GLM_EXPLICIT qua(qua<U, P> const& q);

		/// Explicit conversion operators
#		if GLM_HAS_EXPLICIT_CONVERSION_OPERATORS
			GLM_FUNC_DECL explicit operator mat<3, 3, T, Q>();
			GLM_FUNC_DECL explicit operator mat<4, 4, T, Q>();
#		endif

		/// Create a quaternion from two normalized axis
		///
		/// @param u A first normalized axis
		/// @param v A second normalized axis
		/// @see gtc_quaternion
		/// @see http://lolengine.net/blog/2013/09/18/beautiful-maths-quaternion-from-vectors
		GLM_FUNC_DECL qua(vec<3, T, Q> const& u, vec<3, T, Q> const& v);

		/// Build a quaternion from euler angles (pitch, yaw, roll), in radians.
		GLM_FUNC_DECL GLM_EXPLICIT qua(vec<3, T, Q> const& eulerAngles);
		GLM_FUNC_DECL GLM_EXPLICIT qua(mat<3, 3, T, Q> const& q);
		GLM_FUNC_DECL GLM_EXPLICIT qua(mat<4, 4, T, Q> const& q);

		// -- Unary arithmetic operators --

		GLM_FUNC_DECL qua<T, Q>& operator=(qua<T, Q> const& q) GLM_DEFAULT;

		template<typename U>
		GLM_FUNC_DECL qua<T, Q>& operator=(qua<U, Q> const& q);
		template<typename U>
		GLM_FUNC_DECL qua<T, Q>& operator+=(qua<U, Q> const& q);
		template<typename U>
		GLM_FUNC_DECL qua<T, Q>& operator-=(qua<U, Q> const& q);
		template<typename U>
		GLM_FUNC_DECL qua<T, Q>& operator*=(qua<U, Q> const& q);
		template<typename U>
		GLM_FUNC_DECL qua<T, Q>& operator*=(U s);
		template<typename U>
		GLM_FUNC_DECL qua<T, Q>& operator/=(U s);
	};

	// -- Unary bit operators --

	template<typename T, qualifier Q>
	GLM_FUNC_DECL qua<T, Q> operator+(qua<T, Q> const& q);

	template<typename T, qualifier Q>
	GLM_FUNC_DECL qua<T, Q> operator-(qua<T, Q> const& q);

	// -- Binary operators --

	template<typename T, qualifier Q>
	GLM_FUNC_DECL qua<T, Q> operator+(qua<T, Q> const& q, qua<T, Q> const& p);

	template<typename T, qualifier Q>
	GLM_FUNC_DECL qua<T, Q> operator-(qua<T, Q> const& q, qua<T, Q> const& p);

	template<typename T, qualifier Q>
	GLM_FUNC_DECL qua<T, Q> operator*(qua<T, Q> const& q, qua<T, Q> const& p);

	template<typename T, qualifier Q>
	GLM_FUNC_DECL vec<3, T, Q> operator*(qua<T, Q> const& q, vec<3, T, Q> const& v);

	template<typename T, qualifier Q>
	GLM_FUNC_DECL vec<3, T, Q> operator*(vec<3, T, Q> const& v, qua<T, Q> const& q);

	template<typename T, qualifier Q>
	GLM_FUNC_DECL vec<4, T, Q> operator*(qua<T, Q> const& q, vec<4, T, Q> const& v);

	template<typename T, qualifier Q>
	GLM_FUNC_DECL vec<4, T, Q> operator*(vec<4, T, Q> const& v, qua<T, Q> const& q);

	template<typename T, qualifier Q>
	GLM_FUNC_DECL qua<T, Q> operator*(qua<T, Q> const& q, T const& s);

	template<typename T, qualifier Q>
	GLM_FUNC_DECL qua<T, Q> operator*(T const& s, qua<T, Q> const& q);

	template<typename T, qualifier Q>
	GLM_FUNC_DECL qua<T, Q> operator/(qua<T, Q> const& q, T const& s);

	// -- Boolean operators --

	template<typename T, qualifier Q>
	GLM_FUNC_DECL GLM_CONSTEXPR bool operator==(qua<T, Q> const& q1, qua<T, Q> const& q2);

	template<typename T, qualifier Q>
	GLM_FUNC_DECL GLM_CONSTEXPR bool operator!=(qua<T, Q> const& q1, qua<T, Q> const& q2);

	/// @}
} //namespace glm

#include "type_quat.inl"
