| /////////////////////////////////////////////////////////////////////////////////////////////////// |
| // OpenGL Mathematics Copyright (c) 2005 - 2014 G-Truc Creation (www.g-truc.net) |
| /////////////////////////////////////////////////////////////////////////////////////////////////// |
| // Created : 2006-01-04 |
| // Updated : 2011-10-14 |
| // Licence : This source is under MIT License |
| // File : glm/gtx/fast_square_root.inl |
| /////////////////////////////////////////////////////////////////////////////////////////////////// |
| |
| namespace glm |
| { |
| // fastSqrt |
| template <typename genType> |
| GLM_FUNC_QUALIFIER genType fastSqrt |
| ( |
| genType const & x |
| ) |
| { |
| GLM_STATIC_ASSERT(std::numeric_limits<genType>::is_iec559, "'fastSqrt' only accept floating-point input"); |
| |
| return genType(1) / fastInverseSqrt(x); |
| } |
| |
| VECTORIZE_VEC(fastSqrt) |
| |
| // fastInversesqrt |
| template <> |
| GLM_FUNC_QUALIFIER float fastInverseSqrt<float>(float const & x) |
| { |
| # ifdef __CUDACC__ // Wordaround for a CUDA compiler bug up to CUDA6 |
| detail::tvec1<T, P> tmp(detail::compute_inversesqrt<detail::tvec1, float, lowp>::call(detail::tvec1<float, lowp>(x))); |
| return tmp.x; |
| # else |
| return detail::compute_inversesqrt<detail::tvec1, float, lowp>::call(detail::tvec1<float, lowp>(x)).x; |
| # endif |
| } |
| |
| template <> |
| GLM_FUNC_QUALIFIER double fastInverseSqrt<double>(double const & x) |
| { |
| # ifdef __CUDACC__ // Wordaround for a CUDA compiler bug up to CUDA6 |
| detail::tvec1<T, P> tmp(detail::compute_inversesqrt<detail::tvec1, double, lowp>::call(detail::tvec1<double, lowp>(x))); |
| return tmp.x; |
| # else |
| return detail::compute_inversesqrt<detail::tvec1, double, lowp>::call(detail::tvec1<double, lowp>(x)).x; |
| # endif |
| } |
| |
| template <template <class, precision> class vecType, typename T, precision P> |
| GLM_FUNC_QUALIFIER vecType<T, P> fastInverseSqrt |
| ( |
| vecType<T, P> const & x |
| ) |
| { |
| return detail::compute_inversesqrt<vecType, T, P>::call(x); |
| } |
| |
| VECTORIZE_VEC(fastInverseSqrt) |
| |
| // fastLength |
| template <typename genType> |
| GLM_FUNC_QUALIFIER genType fastLength |
| ( |
| genType const & x |
| ) |
| { |
| return abs(x); |
| } |
| |
| template <typename valType, precision P> |
| GLM_FUNC_QUALIFIER valType fastLength |
| ( |
| detail::tvec2<valType, P> const & x |
| ) |
| { |
| valType sqr = x.x * x.x + x.y * x.y; |
| return fastSqrt(sqr); |
| } |
| |
| template <typename valType, precision P> |
| GLM_FUNC_QUALIFIER valType fastLength |
| ( |
| detail::tvec3<valType, P> const & x |
| ) |
| { |
| valType sqr = x.x * x.x + x.y * x.y + x.z * x.z; |
| return fastSqrt(sqr); |
| } |
| |
| template <typename valType, precision P> |
| GLM_FUNC_QUALIFIER valType fastLength |
| ( |
| detail::tvec4<valType, P> const & x |
| ) |
| { |
| valType sqr = x.x * x.x + x.y * x.y + x.z * x.z + x.w * x.w; |
| return fastSqrt(sqr); |
| } |
| |
| // fastDistance |
| template <typename genType> |
| GLM_FUNC_QUALIFIER genType fastDistance |
| ( |
| genType const & x, |
| genType const & y |
| ) |
| { |
| return fastLength(y - x); |
| } |
| |
| // fastNormalize |
| template <typename genType> |
| GLM_FUNC_QUALIFIER genType fastNormalize |
| ( |
| genType const & x |
| ) |
| { |
| return x > genType(0) ? genType(1) : -genType(1); |
| } |
| |
| template <typename valType, precision P> |
| GLM_FUNC_QUALIFIER detail::tvec2<valType, P> fastNormalize |
| ( |
| detail::tvec2<valType, P> const & x |
| ) |
| { |
| valType sqr = x.x * x.x + x.y * x.y; |
| return x * fastInverseSqrt(sqr); |
| } |
| |
| template <typename valType, precision P> |
| GLM_FUNC_QUALIFIER detail::tvec3<valType, P> fastNormalize |
| ( |
| detail::tvec3<valType, P> const & x |
| ) |
| { |
| valType sqr = x.x * x.x + x.y * x.y + x.z * x.z; |
| return x * fastInverseSqrt(sqr); |
| } |
| |
| template <typename valType, precision P> |
| GLM_FUNC_QUALIFIER detail::tvec4<valType, P> fastNormalize |
| ( |
| detail::tvec4<valType, P> const & x |
| ) |
| { |
| valType sqr = x.x * x.x + x.y * x.y + x.z * x.z + x.w * x.w; |
| return x * fastInverseSqrt(sqr); |
| } |
| }//namespace glm |