81 lines
2.2 KiB
Text
81 lines
2.2 KiB
Text
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/// @ref gtx_fast_square_root
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namespace glm
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{
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// fastSqrt
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template<typename genType>
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GLM_FUNC_QUALIFIER genType fastSqrt(genType x)
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{
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GLM_STATIC_ASSERT(std::numeric_limits<genType>::is_iec559, "'fastSqrt' only accept floating-point input");
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return genType(1) / fastInverseSqrt(x);
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}
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template<length_t L, typename T, qualifier Q>
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GLM_FUNC_QUALIFIER vec<L, T, Q> fastSqrt(vec<L, T, Q> const& x)
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{
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return detail::functor1<vec, L, T, T, Q>::call(fastSqrt, x);
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}
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// fastInversesqrt
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template<typename genType>
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GLM_FUNC_QUALIFIER genType fastInverseSqrt(genType x)
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{
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# ifdef __CUDACC__ // Wordaround for a CUDA compiler bug up to CUDA6
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vec<1, T, Q> tmp(detail::compute_inversesqrt<tvec1, genType, lowp, detail::is_aligned<lowp>::value>::call(vec<1, genType, lowp>(x)));
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return tmp.x;
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# else
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return detail::compute_inversesqrt<1, genType, lowp, detail::is_aligned<lowp>::value>::call(vec<1, genType, lowp>(x)).x;
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# endif
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}
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template<length_t L, typename T, qualifier Q>
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GLM_FUNC_QUALIFIER vec<L, T, Q> fastInverseSqrt(vec<L, T, Q> const& x)
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{
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return detail::compute_inversesqrt<L, T, Q, detail::is_aligned<Q>::value>::call(x);
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}
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// fastLength
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template<typename genType>
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GLM_FUNC_QUALIFIER genType fastLength(genType x)
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{
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GLM_STATIC_ASSERT(std::numeric_limits<genType>::is_iec559, "'fastLength' only accept floating-point inputs");
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return abs(x);
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}
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template<length_t L, typename T, qualifier Q>
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GLM_FUNC_QUALIFIER T fastLength(vec<L, T, Q> const& x)
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{
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GLM_STATIC_ASSERT(std::numeric_limits<T>::is_iec559, "'fastLength' only accept floating-point inputs");
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return fastSqrt(dot(x, x));
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}
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// fastDistance
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template<typename genType>
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GLM_FUNC_QUALIFIER genType fastDistance(genType x, genType y)
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{
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return fastLength(y - x);
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}
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template<length_t L, typename T, qualifier Q>
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GLM_FUNC_QUALIFIER T fastDistance(vec<L, T, Q> const& x, vec<L, T, Q> const& y)
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{
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return fastLength(y - x);
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}
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// fastNormalize
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template<typename genType>
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GLM_FUNC_QUALIFIER genType fastNormalize(genType x)
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{
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return x > genType(0) ? genType(1) : -genType(1);
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}
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template<length_t L, typename T, qualifier Q>
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GLM_FUNC_QUALIFIER vec<L, T, Q> fastNormalize(vec<L, T, Q> const& x)
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{
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return x * fastInverseSqrt(dot(x, x));
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}
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}//namespace glm
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