Description

In this assignment you will work with a simple program which implements a “Sliding Picture Puzzle”. This is a well-known style of game where an image is divided up into squares which are scrambled and need to be manipulated into the correct order:

https://en.wikipedia.org/wiki/Sliding_puzzle

The program in this assignment has a relatively simple class hierarchy. Nevertheless, understanding the flow of control through the program will still be challenging at times and will test your debugging skills.

Picture Puzzle

The picture puzzle game provides a simple GUI where you can load an image, choose the difficulty of the game (e.g. 3×3 vs 4×4) and then play the game. The puzzle is shown in the left panel, with the solution shown on the right:

The game is relatively straightforward to play, though there are some variations. In particular, we can rotate squares by right-clicking on them. This makes the game slightly harder to play, and also makes the program code more interesting (though also more complex).

Getting started

To get started, download the picturepuzzle.jar file from the lecture schedule on the course website. As usual, you can run the program from the command-line as follows:

java -jar picturepuzzle.jar

A simple GUI should appear on your screen, and you should be able to play the game. Remember, however, that at this stage the game contains a number of bugs and missing features. For example, pieces may not move in the direction you are expecting!

When you import the picturepuzzle.jar file, you should find the following Java packages:

• The swen221/picturepuzzle/gui/ package contains the graphical user interface and the main method. You do not need to understand the inner workings of this in order to complete the assignment. NOTE: you do not need to modify any code in this package.
• The swen221/picturepuzzle/model/ package contains the class Game encoding the logic of a game, and the class Board representing the current state of the board.
• The swen221/picturepuzzle/moves/ package contains a class for the two different kinds of move that can be made in the game (move and rotation). These contain code related to structuring a move, and ensuring it is valid.
• The swen221/picturepuzzle/tests/ packages contains many jUnit tests to check your implementation of the game. NOTE: To make the automatic marking possible, you can not modify the files already present in this folder, but you may add your tests in a separate file (e.g.

MyTests.java).

Part 1 — Small Boards

The first objective is to make sure the game correctly implements simple moves on small (i.e. 2 × 2) boards (for now, ignoring rotations). There is a simple defect in the Location class which you must identify and fix. Tests for this part is provided in swen221/picturepuzzle/tests/Part1Tests.java.

Part 2 — Big Boards

The second objective is to make sure the game correctly implements simple moves on larger (e.g. 3×3) boards (for now, still ignoring rotations). There are several defects spread across the Board and Move classes which you must identify and fix. Tests are provided in swen221/picturepuzzle/tests/Part2Tests.java.

Part 3 — Rotation Moves

The third objective is to implement the rotation move in the game. This is a tricky little algorithm to get right, though the test cases should help. You will need to implement the method Rotation.apply().

Tests for this part are provided in swen221/picturepuzzle/tests/Part3Tests.java.

Part 4 — Game Over

The final objective is to implement the test to determine when the game is over. This requires changes to the Board class. Tests are provided in swen221/picturepuzzle/tests/Part4Tests.java.