dungeon/libs/glm/gtx/fast_square_root.inl
2017-09-17 14:45:57 +02:00

81 lines
2.5 KiB
C++

/// @ref gtx_fast_square_root
/// @file glm/gtx/fast_square_root.inl
namespace glm
{
// fastSqrt
template <typename genType>
GLM_FUNC_QUALIFIER genType fastSqrt(genType x)
{
GLM_STATIC_ASSERT(std::numeric_limits<genType>::is_iec559, "'fastSqrt' only accept floating-point input");
return genType(1) / fastInverseSqrt(x);
}
template <typename T, precision P, template <typename, precision> class vecType>
GLM_FUNC_QUALIFIER vecType<T, P> fastSqrt(vecType<T, P> const & x)
{
return detail::functor1<T, T, P, vecType>::call(fastSqrt, x);
}
// fastInversesqrt
template <typename genType>
GLM_FUNC_QUALIFIER genType fastInverseSqrt(genType x)
{
# ifdef __CUDACC__ // Wordaround for a CUDA compiler bug up to CUDA6
tvec1<T, P> tmp(detail::compute_inversesqrt<tvec1, genType, lowp, detail::is_aligned<lowp>::value>::call(tvec1<genType, lowp>(x)));
return tmp.x;
# else
return detail::compute_inversesqrt<tvec1, genType, highp, detail::is_aligned<highp>::value>::call(tvec1<genType, lowp>(x)).x;
# endif
}
template <typename T, precision P, template <typename, precision> class vecType>
GLM_FUNC_QUALIFIER vecType<T, P> fastInverseSqrt(vecType<T, P> const & x)
{
return detail::compute_inversesqrt<vecType, T, P, detail::is_aligned<P>::value>::call(x);
}
// fastLength
template <typename genType>
GLM_FUNC_QUALIFIER genType fastLength(genType x)
{
GLM_STATIC_ASSERT(std::numeric_limits<genType>::is_iec559, "'fastLength' only accept floating-point inputs");
return abs(x);
}
template <typename T, precision P, template <typename, precision> class vecType>
GLM_FUNC_QUALIFIER T fastLength(vecType<T, P> const & x)
{
GLM_STATIC_ASSERT(std::numeric_limits<T>::is_iec559, "'fastLength' only accept floating-point inputs");
return fastSqrt(dot(x, x));
}
// fastDistance
template <typename genType>
GLM_FUNC_QUALIFIER genType fastDistance(genType x, genType y)
{
return fastLength(y - x);
}
template <typename T, precision P, template <typename, precision> class vecType>
GLM_FUNC_QUALIFIER T fastDistance(vecType<T, P> const & x, vecType<T, P> const & y)
{
return fastLength(y - x);
}
// fastNormalize
template <typename genType>
GLM_FUNC_QUALIFIER genType fastNormalize(genType x)
{
return x > genType(0) ? genType(1) : -genType(1);
}
template <typename T, precision P, template <typename, precision> class vecType>
GLM_FUNC_QUALIFIER vecType<T, P> fastNormalize(vecType<T, P> const & x)
{
return x * fastInverseSqrt(dot(x, x));
}
}//namespace glm