The java2d uses the primitives such as Blit loop for rendering differing things. Currently, not all possible variants of primitives are implemented, but it is possible to register some general loop that may produce the primitives for some specific src/comp/dst.

But we have some inconsistent here:
 - Some primitives register themselves as a general loop but always return null in the makePrimitive() method
 - Some primitives (which are not registered as general loops) return null or throw an error in the makePrimitive() method