1 #ifndef MSP_GEOMETRY_HYPERSPHERE_H_
2 #define MSP_GEOMETRY_HYPERSPHERE_H_
6 #include <msp/linal/vector.h>
10 #include "surfacepoint.h"
16 A shape consisting of the points within a specific distance from the origin.
17 Two- and three-dimensional cases are Circle and Sphere, respectively.
19 template<typename T, unsigned D>
20 class HyperSphere: public Shape<T, D>
26 HyperSphere(): radius(1) { }
27 explicit HyperSphere(T);
29 virtual HyperSphere *clone() const;
31 T get_radius() const { return radius; }
33 virtual HyperBox<T, D> get_axis_aligned_bounding_box() const;
34 virtual bool contains(const LinAl::Vector<T, D> &) const;
35 virtual unsigned get_max_ray_intersections() const { return 2; }
36 virtual unsigned get_intersections(const Ray<T, D> &, SurfacePoint<T, D> *, unsigned) const;
39 template<typename T, unsigned D>
40 inline HyperSphere<T, D>::HyperSphere(T r):
44 throw std::invalid_argument("HyperSphere::HyperShpere");
47 template<typename T, unsigned D>
48 inline HyperSphere<T, D> *HyperSphere<T, D>::clone() const
50 return new HyperSphere<T, D>(radius);
53 template<typename T, unsigned D>
54 inline HyperBox<T, D> HyperSphere<T, D>::get_axis_aligned_bounding_box() const
56 LinAl::Vector<T, D> dimensions;
57 for(unsigned i=0; i<D; ++i)
58 dimensions[i] = radius;
59 return HyperBox<T, D>(dimensions);
62 template<typename T, unsigned D>
63 inline bool HyperSphere<T, D>::contains(const LinAl::Vector<T, D> &point) const
65 return inner_product(point, point)<=radius*radius;
68 template<typename T, unsigned D>
69 inline unsigned HyperSphere<T, D>::get_intersections(const Ray<T, D> &ray, SurfacePoint<T, D> *points, unsigned size) const
73 T mid = -inner_product(ray.get_direction(), ray.get_start());
74 LinAl::Vector<T, D> nearest = ray.get_start()+ray.get_direction()*mid;
75 T offset_sq = radius*radius-inner_product(nearest, nearest);
78 T offset = sqrt(offset_sq);
81 for(int i=-1; (n<size && i<=1); i+=2)
84 if(ray.check_limits(x))
88 points[n].position = ray.get_start()+ray.get_direction()*x;
89 points[n].normal = normalize(points[n].position);
90 points[n].distance = x;
100 } // namespace Geometry