text: ///////////////////////////////////////////////////////////////////////////////////
  /// OpenGL Mathematics (glm.g-truc.net)
  ///
  /// Copyright (c) 2005 - 2012 G-Truc Creation (www.g-truc.net)
  /// Permission is hereby granted, free of charge, to any person obtaining a copy
  /// of this software and associated documentation files (the "Software"), to deal
  /// in the Software without restriction, including without limitation the rights
  /// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  /// copies of the Software, and to permit persons to whom the Software is
  /// furnished to do so, subject to the following conditions:
  /// 
  /// The above copyright notice and this permission notice shall be included in
  /// all copies or substantial portions of the Software.
  /// 
  /// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  /// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  /// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  /// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  /// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  /// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  /// THE SOFTWARE.
  ///
  /// @ref gtc_half_float
  /// @file glm/gtc/half_float.hpp
  /// @date 2009-04-29 / 2012-11-06
  /// @author Christophe Riccio
  ///
  /// @see core (dependence)
  ///
  /// @defgroup gtc_half_float GLM_GTC_half_float
  /// @ingroup gtc
  /// 
  /// Defines the half-precision floating-point type, along with various typedefs for vectors and matrices.
  /// <glm/gtc/half_float.hpp> need to be included to use these functionalities.
  ///////////////////////////////////////////////////////////////////////////////////
  
  #ifndef GLM_GTC_half_float
  #define GLM_GTC_half_float GLM_VERSION
  
  // Dependency:
  #include "../glm.hpp"
  
  #if(defined(GLM_MESSAGES) && !defined(glm_ext))
  #	pragma message("GLM: GLM_GTC_half_float extension included")
  #endif
  
  namespace glm{
  namespace detail
  {
  #if(GLM_COMPONENT == GLM_COMPONENT_CXX98)
  	template <>
  	struct tvec2<half>
  	{
  		enum ctor{null};
  		typedef half value_type;
  		typedef std::size_t size_type;
  
  		GLM_FUNC_DECL size_type length() const;
  		static GLM_FUNC_DECL size_type value_size();
  
  		typedef tvec2<half> type;
  		typedef tvec2<bool> bool_type;
  
  		//////////////////////////////////////
  		// Data
  
  		half x, y;
  
  		//////////////////////////////////////
  		// Accesses
  
  		half & operator[](size_type i);
  		half const & operator[](size_type i) const;
  
  		//////////////////////////////////////
  		// Implicit basic constructors
  
  		tvec2();
  		tvec2(tvec2<half> const & v);
  
  		//////////////////////////////////////
  		// Explicit basic constructors
  
  		explicit tvec2(ctor);
  		explicit tvec2(
  			half const & s);
  		explicit tvec2(
  			half const & s1, 
  			half const & s2);
  
  		//////////////////////////////////////
  		// Swizzle constructors
  
  		tvec2(tref2<half> const & r);
  
  		//////////////////////////////////////
  		// Convertion scalar constructors
  
  		//! Explicit converions (From section 5.4.1 Conversion and scalar constructors of GLSL 1.30.08 specification)
  		template <typename U> 
  		explicit tvec2(U const & x);
  		//! Explicit converions (From section 5.4.1 Conversion and scalar constructors of GLSL 1.30.08 specification)
  		template <typename U, typename V> 
  		explicit tvec2(U const & x, V const & y);			
  
  		//////////////////////////////////////
  		// Convertion vector constructors
  
  		//! Explicit conversions (From section 5.4.1 Conversion and scalar constructors of GLSL 1.30.08 specification)
  		template <typename U> 
  		explicit tvec2(tvec2<U> const & v);
  		//! Explicit conversions (From section 5.4.1 Conversion and scalar constructors of GLSL 1.30.08 specification)
  		template <typename U> 
  		explicit tvec2(tvec3<U> const & v);
  		//! Explicit conversions (From section 5.4.1 Conversion and scalar constructors of GLSL 1.30.08 specification)
  		template <typename U> 
  		explicit tvec2(tvec4<U> const & v);
  
  		//////////////////////////////////////
  		// Unary arithmetic operators
  
  		tvec2<half>& operator= (tvec2<half> const & v);
  
  		tvec2<half>& operator+=(half const & s);
  		tvec2<half>& operator+=(tvec2<half> const & v);
  		tvec2<half>& operator-=(half const & s);
  		tvec2<half>& operator-=(tvec2<half> const & v);
  		tvec2<half>& operator*=(half const & s);
  		tvec2<half>& operator*=(tvec2<half> const & v);
  		tvec2<half>& operator/=(half const & s);
  		tvec2<half>& operator/=(tvec2<half> const & v);
  		tvec2<half>& operator++();
  		tvec2<half>& operator--();
  
  		//////////////////////////////////////
  		// Swizzle operators
  
  		half swizzle(comp X) const;
  		tvec2<half> swizzle(comp X, comp Y) const;
  		tvec3<half> swizzle(comp X, comp Y, comp Z) const;
  		tvec4<half> swizzle(comp X, comp Y, comp Z, comp W) const;
  		tref2<half> swizzle(comp X, comp Y);
  	};
  
  	template <>
  	struct tvec3<half>
  	{
  		enum ctor{null};
  		typedef half value_type;
  		typedef std::size_t size_type;
  		GLM_FUNC_DECL size_type length() const;
  		static GLM_FUNC_DECL size_type value_size();
  
  		typedef tvec3<half> type;
  		typedef tvec3<bool> bool_type;
  
  		//////////////////////////////////////
  		// Data
  
  		half x, y, z;
  
  		//////////////////////////////////////
  		// Accesses
  
  		half & operator[](size_type i);
  		half const & operator[](size_type i) const;
  
  		//////////////////////////////////////
  		// Implicit basic constructors
  
  		tvec3();
  		tvec3(tvec3<half> const & v);
  
  		//////////////////////////////////////
  		// Explicit basic constructors
  
  		explicit tvec3(ctor);
  		explicit tvec3(
  			half const & s);
  		explicit tvec3(
  			half const & s1, 
  			half const & s2, 
  			half const & s3);
  
  		//////////////////////////////////////
  		// Swizzle constructors
  
  		tvec3(tref3<half> const & r);
  
  		//////////////////////////////////////
  		// Convertion scalar constructors
  
  		//! Explicit converions (From section 5.4.1 Conversion and scalar constructors of GLSL 1.30.08 specification)
  		template <typename U> 
  		explicit tvec3(U const & x);
  		//! Explicit converions (From section 5.4.1 Conversion and scalar constructors of GLSL 1.30.08 specification)
  		template <typename U, typename V, typename W> 
  		explicit tvec3(U const & x, V const & y, W const & z);			
  
  		//////////////////////////////////////
  		// Convertion vector constructors
  
  		//! Explicit conversions (From section 5.4.1 Conversion and scalar constructors of GLSL 1.30.08 specification)
  		template <typename A, typename B> 
  		explicit tvec3(tvec2<A> const & v, B const & s);
  		//! Explicit conversions (From section 5.4.1 Conversion and scalar constructors of GLSL 1.30.08 specification)
  		template <typename A, typename B> 
  		explicit tvec3(A const & s, tvec2<B> const & v);
  		//! Explicit conversions (From section 5.4.1 Conversion and scalar constructors of GLSL 1.30.08 specification)
  		template <typename U> 
  		explicit tvec3(tvec3<U> const & v);
  		//! Explicit conversions (From section 5.4.1 Conversion and scalar constructors of GLSL 1.30.08 specification)
  		template <typename U> 
  		explicit tvec3(tvec4<U> const & v);
  
  		//////////////////////////////////////
  		// Unary arithmetic operators
  
  		tvec3<half>& operator= (tvec3<half> const & v);
  
  		tvec3<half>& operator+=(half const & s);
  		tvec3<half>& operator+=(tvec3<half> const & v);
  		tvec3<half>& operator-=(half const & s);
  		tvec3<half>& operator-=(tvec3<half> const & v);
  		tvec3<half>& operator*=(half const & s);
  		tvec3<half>& operator*=(tvec3<half> const & v);
  		tvec3<half>& operator/=(half const & s);
  		tvec3<half>& operator/=(tvec3<half> const & v);
  		tvec3<half>& operator++();
  		tvec3<half>& operator--();
  
  		//////////////////////////////////////
  		// Swizzle operators
  
  		half swizzle(comp X) const;
  		tvec2<half> swizzle(comp X, comp Y) const;
  		tvec3<half> swizzle(comp X, comp Y, comp Z) const;
  		tvec4<half> swizzle(comp X, comp Y, comp Z, comp W) const;
  		tref3<half> swizzle(comp X, comp Y, comp Z);
  	};
  
  	template <>
  	struct tvec4<half>
  	{
  		enum ctor{null};
  		typedef half value_type;
  		typedef std::size_t size_type;
  		GLM_FUNC_DECL size_type length() const;
  		static GLM_FUNC_DECL size_type value_size();
  
  		typedef tvec4<half> type;
  		typedef tvec4<bool> bool_type;
  
  		//////////////////////////////////////
  		// Data
  
  		half x, y, z, w;
  
  		//////////////////////////////////////
  		// Accesses
  
  		half & operator[](size_type i);
  		half const & operator[](size_type i) const;
  
  		//////////////////////////////////////
  		// Implicit basic constructors
  
  		tvec4();
  		tvec4(tvec4<half> const & v);
  
  		//////////////////////////////////////
  		// Explicit basic constructors
  
  		explicit tvec4(ctor);
  		explicit tvec4(
  			half const & s);
  		explicit tvec4(
  			half const & s0, 
  			half const & s1, 
  			half const & s2, 
  			half const & s3);
  
  		//////////////////////////////////////
  		// Swizzle constructors
  
  		tvec4(tref4<half> const & r);
  
  		//////////////////////////////////////
  		// Convertion scalar constructors
  
  		//! Explicit converions (From section 5.4.1 Conversion and scalar constructors of GLSL 1.30.08 specification)
  		template <typename U> 
  		explicit tvec4(U const & x);
  		//! Explicit converions (From section 5.4.1 Conversion and scalar constructors of GLSL 1.30.08 specification)
  		template <typename A, typename B, typename C, typename D> 
  		explicit tvec4(A const & x, B const & y, C const & z, D const & w);			
  
  		//////////////////////////////////////
  		// Convertion vector constructors
  
  		//! Explicit conversions (From section 5.4.1 Conversion and scalar constructors of GLSL 1.30.08 specification)
  		template <typename A, typename B, typename C> 
  		explicit tvec4(tvec2<A> const & v, B const & s1, C const & s2);
  		//! Explicit conversions (From section 5.4.1 Conversion and scalar constructors of GLSL 1.30.08 specification)
  		template <typename A, typename B, typename C> 
  		explicit tvec4(A const & s1, tvec2<B> const & v, C const & s2);
  		//! Explicit conversions (From section 5.4.1 Conversion and scalar constructors of GLSL 1.30.08 specification)
  		template <typename A, typename B, typename C> 
  		explicit tvec4(A const & s1, B const & s2, tvec2<C> const & v);
  		//! Explicit conversions (From section 5.4.1 Conversion and scalar constructors of GLSL 1.30.08 specification)
  		template <typename A, typename B> 
  		explicit tvec4(tvec3<A> const & v, B const & s);
  		//! Explicit conversions (From section 5.4.1 Conversion and scalar constructors of GLSL 1.30.08 specification)
  		template <typename A, typename B> 
  		explicit tvec4(A const & s, tvec3<B> const & v);
  		//! Explicit conversions (From section 5.4.1 Conversion and scalar constructors of GLSL 1.30.08 specification)
  		template <typename A, typename B> 
  		explicit tvec4(tvec2<A> const & v1, tvec2<B> const & v2);
  		//! Explicit conversions (From section 5.4.1 Conversion and scalar constructors of GLSL 1.30.08 specification)
  		template <typename U> 
  		explicit tvec4(tvec4<U> const & v);
  
  		//////////////////////////////////////
  		// Unary arithmetic operators
  
  		tvec4<half>& operator= (tvec4<half> const & v);
  
  		tvec4<half>& operator+=(half const & s);
  		tvec4<half>& operator+=(tvec4<half> const & v);
  		tvec4<half>& operator-=(half const & s);
  		tvec4<half>& operator-=(tvec4<half> const & v);
  		tvec4<half>& operator*=(half const & s);
  		tvec4<half>& operator*=(tvec4<half> const & v);
  		tvec4<half>& operator/=(half const & s);
  		tvec4<half>& operator/=(tvec4<half> const & v);
  		tvec4<half>& operator++();
  		tvec4<half>& operator--();
  
  		//////////////////////////////////////
  		// Swizzle operators
  
  		half swizzle(comp X) const;
  		tvec2<half> swizzle(comp X, comp Y) const;
  		tvec3<half> swizzle(comp X, comp Y, comp Z) const;
  		tvec4<half> swizzle(comp X, comp Y, comp Z, comp W) const;
  		tref4<half> swizzle(comp X, comp Y, comp Z, comp W);
  	};
  #endif//(GLM_COMPONENT == GLM_COMPONENT_CXX98)
  }
  //namespace detail
  
  	/// @addtogroup gtc_half_float
  	/// @{
  
  	/// Type for half-precision floating-point numbers. 
  	/// @see gtc_half_float
  	typedef detail::half					half;
  
  	/// Vector of 2 half-precision floating-point numbers. 
  	/// @see gtc_half_float
  	typedef detail::tvec2<detail::half>	hvec2;
  
  	/// Vector of 3 half-precision floating-point numbers.
  	/// @see gtc_half_float
  	typedef detail::tvec3<detail::half>	hvec3;
  
  	/// Vector of 4 half-precision floating-point numbers. 
  	/// @see gtc_half_float
  	typedef detail::tvec4<detail::half>	hvec4;
  
  	/// 2 * 2 matrix of half-precision floating-point numbers.
  	/// @see gtc_half_float
  	typedef detail::tmat2x2<detail::half>	hmat2;
  
  	/// 3 * 3 matrix of half-precision floating-point numbers.
  	/// @see gtc_half_float
  	typedef detail::tmat3x3<detail::half>	hmat3;
  
  	/// 4 * 4 matrix of half-precision floating-point numbers.
  	/// @see gtc_half_float
  	typedef detail::tmat4x4<detail::half>	hmat4;
  
  	/// 2 * 2 matrix of half-precision floating-point numbers.
  	/// @see gtc_half_float
  	typedef detail::tmat2x2<detail::half>	hmat2x2;
  
  	/// 2 * 3 matrix of half-precision floating-point numbers.
  	/// @see gtc_half_float
  	typedef detail::tmat2x3<detail::half>	hmat2x3;
  
  	/// 2 * 4 matrix of half-precision floating-point numbers.
  	/// @see gtc_half_float
  	typedef detail::tmat2x4<detail::half>	hmat2x4;
  
  	/// 3 * 2 matrix of half-precision floating-point numbers.
  	/// @see gtc_half_float
  	typedef detail::tmat3x2<detail::half>	hmat3x2;
  
  	/// 3 * 3 matrix of half-precision floating-point numbers.
  	/// @see gtc_half_float
  	typedef detail::tmat3x3<detail::half>	hmat3x3;
  
  	/// 3 * 4 matrix of half-precision floating-point numbers.
  	/// @see gtc_half_float
  	typedef detail::tmat3x4<detail::half>	hmat3x4;
  
  	/// 4 * 2 matrix of half-precision floating-point numbers.
  	/// @see gtc_half_float
  	typedef detail::tmat4x2<detail::half>	hmat4x2;    
  
  	/// 4 * 3 matrix of half-precision floating-point numbers.
  	/// @see gtc_half_float
  	typedef detail::tmat4x3<detail::half>	hmat4x3;
  
  	/// 4 * 4 matrix of half-precision floating-point numbers.
  	/// @see gtc_half_float
  	typedef detail::tmat4x4<detail::half>	hmat4x4;
  
  	/// Returns the absolute value of a half-precision floating-point value
  	/// @see gtc_half_float
  	half abs(half const & x);
  
  	/// Returns the absolute value of a half-precision floating-point two dimensional vector
  	/// @see gtc_half_float
  	hvec2 abs(hvec2 const & x);
  
  	/// Returns the absolute value of a half-precision floating-point three dimensional vector
  	/// @see gtc_half_float
  	hvec3 abs(hvec3 const & x);
  
  	/// Returns the absolute value of a half-precision floating-point four dimensional vector
  	/// @see gtc_half_float
  	hvec4 abs(hvec4 const & x);
  
  	/// @}
  }// namespace glm
  
  #include "half_float.inl"
  
  #endif//GLM_GTC_half_float
  