Use the coverage function to calculate tighter bounding boxes

[libs/math.git] / source / geometry / hypersphere.h

diff --git a/source/geometry/hypersphere.h b/source/geometry/hypersphere.h
index 6bb4352f4016840ca331ebfd2034f35a7090e7d2..13e4278430b8b5e2a811974a1959d54dac8bd305 100644 (file)
--- a/source/geometry/hypersphere.h
+++ b/source/geometry/hypersphere.h
@@ -27,10 +27,11 @@ public:
 
        T get_radius() const { return radius; }
 
-       virtual BoundingBox<T, D> get_axis_aligned_bounding_box() const;
+       virtual BoundingBox<T, D> get_axis_aligned_bounding_box(unsigned = 0) const;
        virtual bool contains(const LinAl::Vector<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;
+       virtual Coverage get_coverage(const BoundingBox<T, D> &) const;
 };
 
 template<typename T, unsigned D>
@@ -48,7 +49,7 @@ inline HyperSphere<T, D> *HyperSphere<T, D>::clone() const
 }
 
 template<typename T, unsigned D>
-inline BoundingBox<T, D> HyperSphere<T, D>::get_axis_aligned_bounding_box() const
+inline BoundingBox<T, D> HyperSphere<T, D>::get_axis_aligned_bounding_box(unsigned) const
 {
        LinAl::Vector<T, D> extent;
        for(unsigned i=0; i<D; ++i)
@@ -95,6 +96,41 @@ inline unsigned HyperSphere<T, D>::get_intersections(const Ray<T, D> &ray, Surfa
        return n;
 }
 
+template<typename T, unsigned D>
+inline Coverage HyperSphere<T, D>::get_coverage(const BoundingBox<T, D> &bbox) const
+{
+       const LinAl::Vector<T, D> &min_pt = bbox.get_minimum_point();
+       const LinAl::Vector<T, D> &max_pt = bbox.get_maximum_point();
+
+       LinAl::Vector<T, D> far_point;
+       for(unsigned i=0; i<D; ++i)
+               far_point[i] = std::max(std::abs(min_pt[i]), std::abs(max_pt[i]));
+
+       if(contains(far_point))
+               return FULL_COVERAGE;
+
+       unsigned spanned_dimensions = 0;
+       for(unsigned i=0; i<D; ++i)
+               if(min_pt[i]<T(0) && max_pt[i]>T(0))
+                       spanned_dimensions |= 1<<i;
+
+       for(unsigned i=0; i<(1<<D); ++i)
+       {
+               if(i&spanned_dimensions)
+                       continue;
+
+               LinAl::Vector<T, D> point;
+               for(unsigned j=0; j<D; ++j)
+                       if(!((spanned_dimensions>>j)&1))
+                               point[j] = ((i>>j)&1 ? max_pt[j] : min_pt[j]);
+
+               if(contains(point))
+                       return PARTIAL_COVERAGE;
+       }
+
+       return NO_COVERAGE;
+}
+
 } // namespace Geometry
 } // namespace Msp