fp-elevators

Elevator.cpp

Overview

Elevator is a class declared in Elevator.h and is responsible for representing where an elevator is inside the building along with where it is going. It will service requests that come from the Building class.

Member Data

• servicing is a bool representing whether the elevator is currently moving to service a request. When an elevator is servicing, it cannot receive another command.
• currentFloor is an int representing which floor the elevator currently resides
• targetFloor is an int representing which floor an elevator is trying to reach. If an elevator reaches its targetFloor, it will no longer be servicing and will be eligible to service another request.

Member Functions

Many member functions have been written for you. Please refer to their RME’s for use reference.

You will be writing the implementation for the following functions:

• tick (Difficulty: ★☆☆☆☆)
• serviceRequest (Difficulty: ★☆☆☆☆)

tick

/**
* Requires: currentTime is valid
* Modifies: currentFloor, servicing
* Effects:  Moves the value of current floor by 1 in the direction of the target
*           floor if the currentTime is divisible by TICKS_PER_ELEVATOR_MOVE and
*           the elevator is servicing a request.
*           If current floor is the target floor, servicing is set to false
*/
void tick(int currentTime);

tick is the function that advances the game one turn. In the context of Elevator, this involves moving it in the correct direction if it is servicing a request. Specifically, we do the following.

1. If the currentTime is divisible by TICKS_PER_ELEVATOR_MOVE and it is currently servicing a request, we move currentFloor one floor closer to its targetFloor. If the elevator is already at its targetFloor, the elevator does not move.
2. If, after moving the elevator, it has reached its targetFloor, we set servicing to false. It can now service another request.

serviceRequest

/**
* Requires: 0 <= floorNum <= NUM_FLOORS
* Modifies: targetFloor, servicing
* Effects: Sets the targetFloor and marks the Elevator as currently servicing
*/
void serviceRequest(int floorNum);

This is the function that the Building class will use to control its Elevators. It will give the Elevator a floorNum which constitutes a request to send the Elevator to that Floor. This will update the Elevator’s targetFloor, and mark it as servicing until it reaches that floor (remember that tick will be responsible for moving the elevator if it is servicing).