The new FXSpheref and FXSphered classes represent a sphere using FXfloat and FXdouble values, respectively, for the sphere's center point and radius. It doesn't appear that these classes are actually used anywhere in FOX, but they may prove useful for your application code. These classes provide a number of useful member functions, including:
An overloaded contains() member function, for testing whether a specified point, bounding box or other sphere are contained within this sphere;
An overloaded include() member function, which "includes" a specified point, bounding box or other sphere into this sphere, potentially moving the center of the sphere and increasing its radius;
An overloaded overlap() function (not actually a member of FXSphere) for determining whether two spheres overlap each other, or whether a sphere overlaps a bounding box.
For more information, see the FXSpheref.h and FXSphered.h header files from the FOX 1.2 source code distribution.