///////////////////////////////////////////////////////////////////////////////////
/// OpenGL Mathematics (glm.g-truc.net)
///
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/// all copies or substantial portions of the Software.
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///             By making use of the Software for military purposes, you choose to make
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/// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
/// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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/// @ref core
/// @file glm/detail/func_geometric.hpp
/// @date 2008-08-03 / 2011-06-14
/// @author Christophe Riccio
///
/// @see <a href="http://www.opengl.org/registry/doc/GLSLangSpec.4.20.8.pdf">GLSL 4.20.8 specification, section 8.5 Geometric Functions</a>
///
/// @defgroup core_func_geometric Geometric functions
/// @ingroup core
///
/// These operate on vectors as vectors, not component-wise.
///////////////////////////////////////////////////////////////////////////////////

#pragma once

#include "type_vec3.hpp"

namespace glm
{
        /// @addtogroup core_func_geometric
        /// @{

        /// Returns the length of x, i.e., sqrt(x * x).
        ///
        /// @tparam genType Floating-point vector types.
        ///
        /// @see <a href="http://www.opengl.org/sdk/docs/manglsl/xhtml/length.xml">GLSL length man page</a>
        /// @see <a href="http://www.opengl.org/registry/doc/GLSLangSpec.4.20.8.pdf">GLSL 4.20.8 specification, section 8.5 Geometric Functions</a>
        template <typename T, precision P, template <typename, precision> class vecType>
        GLM_FUNC_DECL T length(
                vecType<T, P> const & x);

        /// Returns the distance betwwen p0 and p1, i.e., length(p0 - p1).
        ///
        /// @tparam genType Floating-point vector types.
        ///
        /// @see <a href="http://www.opengl.org/sdk/docs/manglsl/xhtml/distance.xml">GLSL distance man page</a>
        /// @see <a href="http://www.opengl.org/registry/doc/GLSLangSpec.4.20.8.pdf">GLSL 4.20.8 specification, section 8.5 Geometric Functions</a>
        template <typename T, precision P, template <typename, precision> class vecType>
        GLM_FUNC_DECL T distance(
                vecType<T, P> const & p0,
                vecType<T, P> const & p1);

        /// Returns the dot product of x and y, i.e., result = x * y.
        ///
        /// @tparam genType Floating-point vector types.
        ///
        /// @see <a href="http://www.opengl.org/sdk/docs/manglsl/xhtml/dot.xml">GLSL dot man page</a>
        /// @see <a href="http://www.opengl.org/registry/doc/GLSLangSpec.4.20.8.pdf">GLSL 4.20.8 specification, section 8.5 Geometric Functions</a>
        template <typename T, precision P, template <typename, precision> class vecType>
        GLM_FUNC_DECL T dot(
                vecType<T, P> const & x,
                vecType<T, P> const & y);

        /// Returns the cross product of x and y.
        ///
        /// @tparam valType Floating-point scalar types.
        ///
        /// @see <a href="http://www.opengl.org/sdk/docs/manglsl/xhtml/cross.xml">GLSL cross man page</a>
        /// @see <a href="http://www.opengl.org/registry/doc/GLSLangSpec.4.20.8.pdf">GLSL 4.20.8 specification, section 8.5 Geometric Functions</a>
        template <typename T, precision P>
        GLM_FUNC_DECL tvec3<T, P> cross(
                tvec3<T, P> const & x,
                tvec3<T, P> const & y);

        /// Returns a vector in the same direction as x but with length of 1.
        /// According to issue 10 GLSL 1.10 specification, if length(x) == 0 then result is undefined and generate an error.
        ///
        /// @see <a href="http://www.opengl.org/sdk/docs/manglsl/xhtml/normalize.xml">GLSL normalize man page</a>
        /// @see <a href="http://www.opengl.org/registry/doc/GLSLangSpec.4.20.8.pdf">GLSL 4.20.8 specification, section 8.5 Geometric Functions</a>
        template <typename T, precision P, template <typename, precision> class vecType>
        GLM_FUNC_DECL vecType<T, P> normalize(
                vecType<T, P> const & x);

        /// If dot(Nref, I) < 0.0, return N, otherwise, return -N.
        ///
        /// @tparam genType Floating-point vector types.
        ///
        /// @see <a href="http://www.opengl.org/sdk/docs/manglsl/xhtml/faceforward.xml">GLSL faceforward man page</a>
        /// @see <a href="http://www.opengl.org/registry/doc/GLSLangSpec.4.20.8.pdf">GLSL 4.20.8 specification, section 8.5 Geometric Functions</a>
        template <typename T, precision P, template <typename, precision> class vecType>
        GLM_FUNC_DECL vecType<T, P> faceforward(
                vecType<T, P> const & N,
                vecType<T, P> const & I,
                vecType<T, P> const & Nref);

        /// For the incident vector I and surface orientation N,
        /// returns the reflection direction : result = I - 2.0 * dot(N, I) * N.
        ///
        /// @tparam genType Floating-point vector types.
        ///
        /// @see <a href="http://www.opengl.org/sdk/docs/manglsl/xhtml/reflect.xml">GLSL reflect man page</a>
        /// @see <a href="http://www.opengl.org/registry/doc/GLSLangSpec.4.20.8.pdf">GLSL 4.20.8 specification, section 8.5 Geometric Functions</a>
        template <typename genType>
        GLM_FUNC_DECL genType reflect(
                genType const & I,
                genType const & N);

        /// For the incident vector I and surface normal N,
        /// and the ratio of indices of refraction eta,
        /// return the refraction vector.
        ///
        /// @tparam genType Floating-point vector types.
        ///
        /// @see <a href="http://www.opengl.org/sdk/docs/manglsl/xhtml/refract.xml">GLSL refract man page</a>
        /// @see <a href="http://www.opengl.org/registry/doc/GLSLangSpec.4.20.8.pdf">GLSL 4.20.8 specification, section 8.5 Geometric Functions</a>
        template <typename T, precision P, template <typename, precision> class vecType>
        GLM_FUNC_DECL vecType<T, P> refract(
                vecType<T, P> const & I,
                vecType<T, P> const & N,
                T eta);

        /// @}
}//namespace glm

#include "func_geometric.inl"