In future columns, I'll examine some of those enhancements, such as shading and texture mapping. An abstract Portal class implements basic portal functionality. It is a subtype of class Canvas . Actual portals should be subclasses of class Portal and should implement any of the functionality specific to their needs. The Port class is one such class.
Transformations cause changes to the world.
A transformation is represented by an instance of interface Transformation . If you've stuck with me this far, you deserve a reward. I think a trip to the beach is in order. And with this beach you don't even have to ask your boss for time off. Before you turn over to toast your backside, take some time to peruse the code that builds the model .