namespace glm
{
	/// @addtogroup gtx_vector_angle
	/// @{

	//! Returns the absolute angle between two vectors.
	//! Parameters need to be normalized.
	/// @see gtx_vector_angle extension.
	template<length_t L, typename T, qualifier Q>
	GLM_FUNC_DECL T angle(vec<L, T, Q> const& x, vec<L, T, Q> const& y);

	//! Returns the oriented angle between two 2d vectors.
	//! Parameters need to be normalized.
	/// @see gtx_vector_angle extension.
	template<typename T, qualifier Q>
	GLM_FUNC_DECL T orientedAngle(vec<2, T, Q> const& x, vec<2, T, Q> const& y);

	//! Returns the oriented angle between two 3d vectors based from a reference axis.
	//! Parameters need to be normalized.
	/// @see gtx_vector_angle extension.
	template<typename T, qualifier Q>
	GLM_FUNC_DECL T orientedAngle(vec<3, T, Q> const& x, vec<3, T, Q> const& y, vec<3, T, Q> const& ref);

	/// @}
}// namespace glm

#include "vector_angle.inl"
