/// @ref gtx_fast_square_root

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<length_t L, typename T, qualifier Q>
GLM_FUNC_QUALIFIER vec<L, T, Q>
fastSqrt(vec<L, T, Q>
const& x)
{
return
detail::functor1<vec, L, T, T, Q>::call(fastSqrt, x
);
}

// fastInversesqrt
template<typename genType>
GLM_FUNC_QUALIFIER genType
fastInverseSqrt(genType
x)
{
return
detail::compute_inversesqrt<1, genType, lowp, detail::is_aligned<lowp>::value>::call(vec<1, genType, lowp>(x)
).
x;
}

template<length_t L, typename T, qualifier Q>
GLM_FUNC_QUALIFIER vec<L, T, Q>
fastInverseSqrt(vec<L, T, Q>
const& x)
{
return
detail::compute_inversesqrt<L, T, Q, detail::is_aligned<Q>::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<length_t L, typename T, qualifier Q>
GLM_FUNC_QUALIFIER T
fastLength(vec<L, T, Q>
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<length_t L, typename T, qualifier Q>
GLM_FUNC_QUALIFIER T
fastDistance(vec<L, T, Q>
const& x,
vec<L, T, Q> 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<length_t L, typename T, qualifier Q>
GLM_FUNC_QUALIFIER vec<L, T, Q>
fastNormalize(vec<L, T, Q>
const& x)
{
return
x *fastInverseSqrt(dot(x, x));
}
}//namespace glm
