#include "hyperbox.h"
#include "ray.h"
#include "shape.h"
+#include "surfacepoint.h"
namespace Msp {
namespace Geometry {
+/**
+A shape consisting of the points within a specific distance from the origin.
+Two- and three-dimensional cases are Circle and Sphere, respectively.
+*/
template<typename T, unsigned D>
class HyperSphere: public Shape<T, D>
{
T get_radius() const { return radius; }
virtual HyperBox<T, D> get_axis_aligned_bounding_box() const;
+ virtual bool contains(const LinAl::Vector<T, D> &) const;
virtual bool check_intersection(const Ray<T, D> &) const;
+ virtual unsigned get_max_ray_intersections() const { return 2; }
+ virtual unsigned get_intersections(const Ray<T, D> &, SurfacePoint<T, D> *, unsigned) const;
};
template<typename T, unsigned D>
return HyperBox<T, D>(dimensions);
}
+template<typename T, unsigned D>
+inline bool HyperSphere<T, D>::contains(const LinAl::Vector<T, D> &point) const
+{
+ return inner_product(point, point)<=radius*radius;
+}
+
template<typename T, unsigned D>
inline bool HyperSphere<T, D>::check_intersection(const Ray<T, D> &ray) const
{
T x = inner_product(ray.get_direction(), ray.get_start());
if(x>0)
- return inner_product(ray.get_start(), ray.get_start())<=radius*radius;
+ return contains(ray.get_start());
else
+ return contains(ray.get_start()-ray.get_direction()*x);
+}
+
+template<typename T, unsigned D>
+inline unsigned HyperSphere<T, D>::get_intersections(const Ray<T, D> &ray, SurfacePoint<T, D> *points, unsigned size) const
+{
+ T mid = -inner_product(ray.get_direction(), ray.get_start());
+ LinAl::Vector<T, D> nearest = ray.get_start()+ray.get_direction()*mid;
+ T offset_sq = radius*radius-inner_product(nearest, nearest);
+ if(offset_sq<0)
+ return 0;
+ T offset = sqrt(offset_sq);
+
+ unsigned n = 0;
+ for(int i=-1; i<=1; i+=2)
{
- LinAl::Vector<T, D> nearest = ray.get_start()-ray.get_direction()*x;
- return inner_product(nearest, nearest)<=radius*radius;
+ T x = mid+offset*i;
+ if(x>0 && n<size)
+ {
+ if(points)
+ {
+ points[n].position = ray.get_start()+ray.get_direction()*x;
+ points[n].normal = normalize(points[n].position);
+ }
+
+ ++n;
+ if(n==size)
+ return n;
+ }
}
+
+ return n;
}
} // namespace Geometry