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/// @ref gtx_bit
namespace glm
{
///////////////////
// highestBitValue
template<typename genIUType>
GLM_FUNC_QUALIFIER genIUType highestBitValue(genIUType Value)
{
genIUType tmp = Value;
genIUType result = genIUType(0);
while(tmp)
{
result = (tmp & (~tmp + 1)); // grab lowest bit
tmp &= ~result; // clear lowest bit
}
return result;
}
template<length_t L, typename T, qualifier Q>
GLM_FUNC_QUALIFIER vec<L, T, Q> highestBitValue(vec<L, T, Q> const& v)
{
return detail::functor1<vec, L, T, T, Q>::call(highestBitValue, v);
}
///////////////////
// lowestBitValue
template<typename genIUType>
GLM_FUNC_QUALIFIER genIUType lowestBitValue(genIUType Value)
{
return (Value & (~Value + 1));
}
template<length_t L, typename T, qualifier Q>
GLM_FUNC_QUALIFIER vec<L, T, Q> lowestBitValue(vec<L, T, Q> const& v)
{
return detail::functor1<vec, L, T, T, Q>::call(lowestBitValue, v);
}
///////////////////
// powerOfTwoAbove
template<typename genType>
GLM_FUNC_QUALIFIER genType powerOfTwoAbove(genType value)
{
return isPowerOfTwo(value) ? value : highestBitValue(value) << 1;
}
template<length_t L, typename T, qualifier Q>
GLM_FUNC_QUALIFIER vec<L, T, Q> powerOfTwoAbove(vec<L, T, Q> const& v)
{
return detail::functor1<vec, L, T, T, Q>::call(powerOfTwoAbove, v);
}
///////////////////
// powerOfTwoBelow
template<typename genType>
GLM_FUNC_QUALIFIER genType powerOfTwoBelow(genType value)
{
return isPowerOfTwo(value) ? value : highestBitValue(value);
}
template<length_t L, typename T, qualifier Q>
GLM_FUNC_QUALIFIER vec<L, T, Q> powerOfTwoBelow(vec<L, T, Q> const& v)
{
return detail::functor1<vec, L, T, T, Q>::call(powerOfTwoBelow, v);
}
/////////////////////
// powerOfTwoNearest
template<typename genType>
GLM_FUNC_QUALIFIER genType powerOfTwoNearest(genType value)
{
if(isPowerOfTwo(value))
return value;
genType const prev = highestBitValue(value);
genType const next = prev << 1;
return (next - value) < (value - prev) ? next : prev;
}
template<length_t L, typename T, qualifier Q>
GLM_FUNC_QUALIFIER vec<L, T, Q> powerOfTwoNearest(vec<L, T, Q> const& v)
{
return detail::functor1<vec, L, T, T, Q>::call(powerOfTwoNearest, v);
}
}//namespace glm
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