Transport

From Gamewiki

Transport is an essential pattern. A boat transports people as it sails across the waters. A conveyor belt transports components in a factory. Suppose one agent needs to carry another agent as it moves. Before moving right, say, the transporting agent should send a “move right” message to the transported agent on top of it (if there is one). The transported agent moves right when it receives that message. An example would be the logs in Frogger. Say, there is a log floating on top of water. On top of the log is a frog. The log moves to the right but should transport anything on top of it. The log, before it moves to the right checks if there is a frog on top of it. If so, the log moves to right and then makes the frog to the right as well. The log needs to move before the frog to preserve the order of the stack. If the frog moves before the log it would be covered by the log.

Log transports Frog Video Example

Log transports Frog UML diagram