Given types of objects, one needs to implement algorithms to cover for all pairwise combinations. The GJK algorithm is able to avoid such a profileration of cases by abstracting a convex shape by using a so-called support mapping. One algorithm is then sufficient to handle all overlap testing (and more) in a large class of convex shapes. The advantages of specialized testing include:
The disadvantages include:
The GJK and the specialized algorithms complement each other. An ideal case would be to provide both.