///////////////////////////////////////////////////////////////////////////////////////////////////
// OpenGL Mathematics Copyright (c) 2005 - 2011 G-Truc Creation (www.g-truc.net)
///////////////////////////////////////////////////////////////////////////////////////////////////
// Created : 2009-05-21
// Updated : 2010-02-04
// Licence : This source is under MIT License
// File    : glm/gtc/quaternion.hpp
///////////////////////////////////////////////////////////////////////////////////////////////////
// Dependency:
// - GLM core
// - GLM_GTC_half_float
///////////////////////////////////////////////////////////////////////////////////////////////////
// ToDo:
// - Study constructors with angles and axis
// - Study constructors with vec3 that are the imaginary component of quaternion
///////////////////////////////////////////////////////////////////////////////////////////////////

#ifndef glm_gtc_quaternion
#define glm_gtc_quaternion

// Dependency:
#include "../glm.hpp"
#include "../gtc/half_float.hpp"

#if(defined(GLM_MESSAGES) && !defined(glm_ext))
#	pragma message("GLM: GLM_GTC_quaternion extension included")
#endif

namespace glm{
namespace detail
{
	//! \brief Template for quaternion. 
	//! From GLM_GTC_quaternion extension.
	/// \ingroup gtc_quaternion
	template <typename T> 
	struct tquat// : public genType<T, tquat>
	{
		typedef T value_type;

	public:
		value_type x, y, z, w;

		// Constructors
		tquat();
		explicit tquat(
			value_type const & s, 
			tvec3<T> const & v);
		explicit tquat(
			value_type const & w, 
			value_type const & x, 
			value_type const & y, 
			value_type const & z);

		// Convertions
		//explicit tquat(valType const & pitch, valType const & yaw, valType const & roll);
		//! Build a quaternion from euler angles (pitch, yaw, roll), in radians.
		explicit tquat(
			tvec3<T> const & eulerAngles);
		explicit tquat(
			tmat3x3<T> const & m);
		explicit tquat(
			tmat4x4<T> const & m);

		// Accesses
		value_type & operator[](int i);
		value_type const & operator[](int i) const;

		// Operators
		tquat<T> & operator*=(value_type const & s);
		tquat<T> & operator/=(value_type const & s);
	};

	template <typename T> 
	detail::tquat<T> operator- (
		detail::tquat<T> const & q);

	template <typename T> 
	detail::tquat<T> operator+ ( 
		detail::tquat<T> const & q, 
		detail::tquat<T> const & p); 

	template <typename T> 
	detail::tquat<T> operator* ( 
		detail::tquat<T> const & q, 
		detail::tquat<T> const & p); 

	template <typename T> 
	detail::tvec3<T> operator* (
		detail::tquat<T> const & q, 
		detail::tvec3<T> const & v);

	template <typename T> 
	detail::tvec3<T> operator* (
		detail::tvec3<T> const & v,
		detail::tquat<T> const & q);

	template <typename T> 
	detail::tvec4<T> operator* (
		detail::tquat<T> const & q, 
		detail::tvec4<T> const & v);

	template <typename T> 
	detail::tvec4<T> operator* (
		detail::tvec4<T> const & v,
		detail::tquat<T> const & q);

	template <typename T> 
	detail::tquat<T> operator* (
		detail::tquat<T> const & q, 
		typename detail::tquat<T>::value_type const & s);

	template <typename T> 
	detail::tquat<T> operator* (
		typename detail::tquat<T>::value_type const & s,
		detail::tquat<T> const & q);

	template <typename T> 
	detail::tquat<T> operator/ (
		detail::tquat<T> const & q, 
		typename detail::tquat<T>::value_type const & s);

} //namespace detail

namespace gtc{
namespace quaternion ///< GLM_GTC_quaternion extension: Quaternion types and functions
{
	/// @addtogroup gtc_quaternion
	/// @{

	//! Returns the length of the quaternion. 
	//! From GLM_GTC_quaternion extension.
    template <typename T> 
	typename detail::tquat<T>::value_type length(
		detail::tquat<T> const & q);

    //! Returns the normalized quaternion. 
	//! From GLM_GTC_quaternion extension.
	template <typename T> 
	detail::tquat<T> normalize(
		detail::tquat<T> const & q);
		
    //! Returns dot product of q1 and q2, i.e., q1[0] * q2[0] + q1[1] * q2[1] + ... 
	//! From GLM_GTC_quaternion extension.
	template <typename T> 
	typename detail::tquat<T>::value_type dot(
		detail::tquat<T> const & q1, 
		detail::tquat<T> const & q2);

    //! Returns the cross product of q1 and q2. 
	//! From GLM_GTC_quaternion extension.
	template <typename T> 
	GLM_DEPRECATED detail::tquat<T> cross(
		detail::tquat<T> const & q1, 
		detail::tquat<T> const & q2);
		
	//! Returns a SLERP interpolated quaternion of x and y according a. 
	//! From GLM_GTC_quaternion extension.
	template <typename T> 
	detail::tquat<T> mix(
		detail::tquat<T> const & x, 
		detail::tquat<T> const & y, 
		T const & a);
		
	//! Returns the q conjugate. 
	//! From GLM_GTC_quaternion extension.
    template <typename T> 
	detail::tquat<T> conjugate(
		detail::tquat<T> const & q);

	//! Returns the q inverse. 
	//! From GLM_GTC_quaternion extension.
    template <typename T> 
	detail::tquat<T> inverse(
		detail::tquat<T> const & q);

	//! Rotates a quaternion from an vector of 3 components axis and an angle expressed in degrees.
	//! From GLM_GTC_quaternion extension.
	template <typename T> 
	detail::tquat<T> rotate(
		detail::tquat<T> const & q, 
		typename detail::tquat<T>::value_type const & angle, 
		detail::tvec3<T> const & v);

	//! Converts a quaternion to a 3 * 3 matrix. 
	//! From GLM_GTC_quaternion extension.
    template <typename T> 
	detail::tmat3x3<T> mat3_cast(
		detail::tquat<T> const & x);

	//! Converts a quaternion to a 4 * 4 matrix. 
	//! From GLM_GTC_quaternion extension.
	template <typename T> 
	detail::tmat4x4<T> mat4_cast(
		detail::tquat<T> const & x);

	//! Converts a 3 * 3 matrix to a quaternion. 
	//! From GLM_GTC_quaternion extension.
	template <typename T> 
	detail::tquat<T> quat_cast(
		detail::tmat3x3<T> const & x);

	//! Converts a 4 * 4 matrix to a quaternion. 
	//! From GLM_GTC_quaternion extension.
	template <typename T> 
	detail::tquat<T> quat_cast(
		detail::tmat4x4<T> const & x);

	//! Quaternion of floating-point numbers. 
	//! From GLM_GTC_quaternion extension.
    typedef detail::tquat<float> quat;

	//! Quaternion of half-precision floating-point numbers.
	//! From GLM_GTC_quaternion extension.
	typedef detail::tquat<detail::thalf>	hquat;

	//! Quaternion of single-precision floating-point numbers. 
	//! From GLM_GTC_quaternion extension.
	typedef detail::tquat<float>	fquat;

	//! Quaternion of double-precision floating-point numbers. 
	//! From GLM_GTC_quaternion extension.
	typedef detail::tquat<double>	dquat;

	//! Quaternion of low precision floating-point numbers.
	//! From GLM_GTC_quaternion extension.
	typedef detail::tquat<lowp_float>		lowp_quat;

	//! Quaternion of medium precision floating-point numbers. 
	//! From GLM_GTC_quaternion extension.
	typedef detail::tquat<mediump_float>	mediump_quat;

	//! Quaternion of high precision floating-point numbers. 
	//! From GLM_GTC_quaternion extension.
	typedef detail::tquat<highp_float>		highp_quat;
	/// @}

} //namespace quaternion
} //namespace gtc
} //namespace glm

#include "quaternion.inl"

namespace glm{using namespace gtc::quaternion;}

#endif//glm_gtc_quaternion
