1 ///////////////////////////////////////////////////////////////////////////////////
2 /// OpenGL Mathematics (glm.g-truc.net)
3 ///
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23 /// @ref gtx_fast_square_root
24 /// @file glm/gtx/fast_square_root.hpp
25 /// @date 2006-01-04 / 2011-06-07
26 /// @author Christophe Riccio
27 ///
28 /// @see core (dependence)
29 ///
30 /// @defgroup gtx_fast_square_root GLM_GTX_fast_square_root
31 /// @ingroup gtx
32 ///
33 /// @brief Fast but less accurate implementations of square root based functions.
34 /// - Sqrt optimisation based on Newton's method,
35 /// www.gamedev.net/community/forums/topic.asp?topic id=139956
36 ///
37 /// <glm/gtx/fast_square_root.hpp> need to be included to use these functionalities.
38 ///////////////////////////////////////////////////////////////////////////////////
39 
40 #ifndef GLM_GTX_fast_square_root
41 #define GLM_GTX_fast_square_root
42 
43 // Dependency:
44 #include "../glm.hpp"
45 
46 #if(defined(GLM_MESSAGES) && !defined(GLM_EXT_INCLUDED))
47 #	pragma message("GLM: GLM_GTX_fast_square_root extension included")
48 #endif
49 
50 namespace glm
51 {
52 	/// @addtogroup gtx_fast_square_root
53 	/// @{
54 
55 	//! Faster than the common sqrt function but less accurate.
56 	//! From GLM_GTX_fast_square_root extension.
57 	template <typename genType>
58 	GLM_FUNC_DECL genType fastSqrt(genType const & x);
59 
60 	//! Faster than the common inversesqrt function but less accurate.
61 	//! From GLM_GTX_fast_square_root extension.
62 	template <typename genType>
63 	GLM_FUNC_DECL genType fastInverseSqrt(genType const & x);
64 
65 	//! Faster than the common inversesqrt function but less accurate.
66 	//! From GLM_GTX_fast_square_root extension.
67 	template <typename T, precision P, template <typename, precision> class vecType>
68 	GLM_FUNC_DECL vecType<T, P> fastInverseSqrt(vecType<T, P> const & x);
69 
70 	//! Faster than the common length function but less accurate.
71 	//! From GLM_GTX_fast_square_root extension.
72 	template <typename genType>
73 	GLM_FUNC_DECL typename genType::value_type fastLength(genType const & x);
74 
75 	//! Faster than the common distance function but less accurate.
76 	//! From GLM_GTX_fast_square_root extension.
77 	template <typename genType>
78 	GLM_FUNC_DECL typename genType::value_type fastDistance(genType const & x, genType const & y);
79 
80 	//! Faster than the common normalize function but less accurate.
81 	//! From GLM_GTX_fast_square_root extension.
82 	template <typename genType>
83 	GLM_FUNC_DECL genType fastNormalize(genType const & x);
84 
85 	/// @}
86 }// namespace glm
87 
88 #include "fast_square_root.inl"
89 
90 #endif//GLM_GTX_fast_square_root
91