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Add generic ort(vector) implementation

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This commit is contained in:
Nikita Lisitsa 2020-10-08 10:48:03 +03:00
parent bd861a13c7
commit dc0f08e5c3
1 changed files with 34 additions and 6 deletions
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40
libs/geom/include/psemek/geom/vector.hpp
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@ -234,12 +234,6 @@ namespace psemek::geom
}
// TODO: generic implementation (shares internals with det)
template <typename T>
vector<T, 2> ort(vector<T, 2> const & v0)
{
return {-v0[1], v0[0]};
}
template <typename T>
vector<T, 3> ort(vector<T, 3> const & v0, vector<T, 3> const & v1)
{
@ -250,6 +244,40 @@ namespace psemek::geom
};
}
// Any vector orthogonal to v
// N.B.: discontinuous in odd dimensions
template <typename T, std::size_t N>
vector<T, N> ort(vector<T, N> const & v)
{
vector<T, N> result;
if constexpr ((N % 2) == 0)
{
for (std::size_t i = 0; i < N; i += 2)
{
result[i] = -v[i + 1];
result[i + 1] = v[i];
}
}
else
{
std::size_t i = 0, j = 1;
for (std::size_t k = 1; k < N; ++k)
{
if (std::abs(v[k]) > std::abs(v[i]))
{
j = i;
i = k;
}
}
result = vector<T, N>::zero();
result[i] = -v[j];
result[j] = v[i];
}
return result;
}
template <typename T>
vector<T, 3> cross(vector<T, 3> const & v0, vector<T, 3> const & v1)
{