44 lines
887 B
C++
44 lines
887 B
C++
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#ifndef GEOAPI_KDTREE_MATH_HPP
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#define GEOAPI_KDTREE_MATH_HPP
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#include <limits>
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#include <cmath>
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#include "point.hpp"
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namespace kd {
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namespace math {
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using byte = unsigned char;
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// returns the squared distance between two points
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template<class T>
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T distance_sq(const Point<T>& a, const Point<T>& b)
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{
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auto dx = a.longitude - b.longitude;
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auto dy = a.latitude - b.latitude;
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return dx * dx + dy * dy;
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}
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// returns the distance between two points
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template<class T>
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T distance(const Point<T>& a, const Point<T>& b)
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{
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return std::sqrt(distance_sq(a, b));
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}
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// returns the distance between two points looking at a specific axis
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// \param axis 0 if abscissa else 1 if ordinate
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template <class T>
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T axial_distance(const Point<T>& a, const Point<T>& b, byte axis)
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{
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return axis == 0 ?
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a.longitude - b.longitude:
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a.latitude - b.latitude;
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}
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}
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}
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#endif
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