Oriented_side |
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returns the relative position of point t
to the oriented sphere defined by p, q, r and s.
The order of the points p, q, r, and s is important,
since it determines the orientation of the implicitly
constructed sphere. If the points p, q, r and s
are positive oriented, positive side is the bounded interior
of the sphere.
In case of degeneracies, ON_ORIENTED_BOUNDARY is returned if all points are coplanar. Otherwise, there is a cyclic permutation of the five points that puts four non coplanar points first, it is used to answer the predicate: e.g. side_of_oriented_sphere(q, r, s, t, p) is returned if q, r, s, and t are non coplanar. |