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<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