Practical 2 – Animal Chess

CS5001 Object-Oriented Modelling, Design and
Programming
Practical 2 – Animal Chess
School of Computer Science
University of St Andrews
Due Friday week 5, weighting 35%
MMS is the definitive source for deadlines and weightings.
In this practical, you will be provided with an object-oriented model, and your task will be to
implement it in Java. The model is specified by two things: a UML class diagram showing the
required classes, and a suite of tests that define how your program should behave. The details
of implementation are up to you: after creating the classes in Java, you will need to fill in their
methods yourself, and decide on any additional fields, methods, classes etc. that you might
need in order to meet the requirements.
For this practical, you may develop your code in the IDE or text editor of your choice, but you must
ensure all your source code is in a folder named CS5001-p2-animal-chess/src/animalchess ,
where animalchess corresponds to the package name required by the specification.
Animal Chess
The game of chess reached Japan from India around one thousand years ago, and over the
centuries it developed rather differently in Japan from the rest of the world. The game’s focus
switched towards pieces that move only one square at a time, and curious innovations arose,
including a more complex system of promotions, and the ability to “drop” a captured piece onto
the board with its colour changed. The most popular chess variant in Japan today is known as
Shogi (or The Game of Generals); it has gained popularity over the years, and now has a significant
number of players outside the country.
The subject of this practical is a variation of Goro-Goro Dobutsu Shogi (or Purring Animal Chess),
a small Shogi variant designed by professional Shogi player Madoka Kitao, her aim being to
introduce children to Shogi. The game is played on a 5×6 board, and features four different
animals which all move in different ways, with similarities to pieces found in chess. In this
practical we will use rules that are a little different from those designed by Kitao, so read the
following rules carefully.
Game Rules
The two players sit facing each other, with eight pieces each: a lion, two giraffes, two cats and
three chicks. Pieces are oriented on the board so that they appear “face up” to the player that
owns them. Players take turns moving one of their own pieces.
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• A chick moves one space forward.
• A giraffe moves one space forward, backward, left or right (4 directions).
• A cat moves one space in any diagonal direction, or directly forward (5 directions).
• A lion moves one space in any direction, either orthogonal or diagonal (8 directions).
These directions are shown on the playing pieces with red dots.
Figure 1: The board at the start of a game
A player cannot move a piece onto one of their own pieces, but they may move onto one of their
opponent’s pieces, in which case the opponent’s piece is captured. The capturing player takes
the piece into their hand, and on a future turn, instead of moving a piece, they may drop a
captured piece, by placing it onto any empty space on the board as one of their own pieces. A
player wins by capturing their opponent’s lion.
The chick and cat pieces are promotable. If a player moves a chick or a cat into the farthest two
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rows from them (the two rows closest to their opponent) then it promotes. In a real game, this
is shown by flipping the piece over to show a different picture on the other side (a promoted
chick looks like a rooster, and a promoted cat has a fish!).
A piece that has been promoted moves one space forward, backward, left or right, or diagonally
forward (6 directions).
Figure 2: How chicks and cats move after promotion
Note the following important rules:
• There is no such thing as check or checkmate as in chess. You win simply by capturing your
opponent’s lion.
• There is no rule about endless repetition as in chess. A game can go on forever.
• When a promotable piece enters the promotion zone, it must promote.
• When a promotable piece is captured, it “un-promotes”, returning to its original form.
Remember: the rules for this practical are as specified in this document and in the tests on
StudRes. The rules are slightly different from similar games you can read about online.
System Specification
You are required to implement the classes shown in the following UML class diagram, including
all the public methods and attributes shown. Your program should not require any input from the
user, nor print any output to the screen. Your code can be tested by running the JUnit tests that are
included with this practical. This can be done on the lab machines using stacscheck, by navigating
into your CS5001-p2-animal-chess/ directory and running the following command:
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stacscheck /cs/studres/CS5001/Practicals/p2-animalchess/Tests
This will compile your classes and run all the provided tests on them. You can access stacscheck
on the lab machines or via SSH, or if you use a Linux or Mac machine, you can install it on your
own computer.
Important: The behaviour we want from the system is defined by these tests. If you’re not absolutely sure what a class or method is supposed to do, you should look at the tests that correspond
to it and examine the examples and assertions there. The relevant unit test files are in subdirectories of the Tests/ directory, and they all have names of the form <classname>Test.java .
You can add to these by creating your own additional tests if you wish. You can run your own
JUnit tests in an IDE, via the command line, or via stacscheck. If an aspect of the program’s
behaviour is not defined by the tests or the UML diagram, you should make your own choice
about what the program should do, and document this in your code as a comment.
UML class diagram
The UML diagram included below shows the structure of the system you should build. You
should include every class and every public method on the diagram, but you may implement
more classes and methods if you wish, and the choice of private attributes and methods is up to
you.
In this diagram, each yellow box is one class. The ‘C’ symbol in the top part refers to a class,
while the ‘A’ symbol refers to an abstract class. Chick , Giraffe , Cat and Lion are all
special types of Piece , so they inherit its public methods. Chick and Cat also inherit
from PromotablePiece , which defines some special functionality for pieces that can promote.
PromotablePiece and Lion show some methods marked with {override} – this is a hint that
you might want to override these methods in these particular classes. Each Piece is owned by
one Player , and may sit on one Square (if it is not in a player’s hand). The whole Game has
two Players , and 30 Square s (the 5×6 board shown above). When a player moves a piece
onto a square, they can use the square’s isPromotionZone method to test whether their piece
is in the zone where it promotes (the farthest two ranks from the player).
Exception handling
An exception of the class IllegalArgumentException should be thrown if a player tries to
drop a piece that is not in their hand, or if placePiece attempts to place a piece on a square
that is already occupied. It may also be used in other situations where an operation cannot
be carried out because of an illegal argument. A short message describing what went wrong
should be included in the exception. Make sure to catch it and handle it where appropriate!
Packages
Also shown on the UML diagram is the name of the package into which your classes should be
placed: animalchess . Your .java files should be placed in the corresponding subdirectory
inside your src/ directory. You should make sure to declare this package at the top of each
file, with the line package animalchess; .
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Figure 3: UML class diagram of the required system
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Behaviour
A player has an attribute playerNumber , which should be either 0 or 1. Player 0 sits at the top
of the board, and player 1 sits at the bottom of the board. Each Square has a position on the
board defined by its row and col attributes: these should be numbers between 0 and 5, as
shown by the (row, col) pairs in the following diagram.
Figure 4: (row, col) coordinates on the board
Note: Certain events, such as a piece being promoted, or a player winning, are triggered by
public methods. These events can be forced by calling the appropriate method – for example,
player.winGame() – but should also be triggered according to the rules of the game. For
example, a player should win when they take their opponent’s lion.
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Deliverables
A report is not necessary for this project, but if you have strayed from the specification at all, or
if you have made any design decisions that you wish to explain, you can include a short readme
file in your CS5001-p2-animal-chess/ folder; this should include any necessary instructions
for compiling or running your program. Hand in an archive of your assignment folder, including
your src/ directory and any local test subdirectories, via MMS as usual.
Marking
A submission that does not satisfy all the tests above may still receive a good grade. A submission
that implements all classes and methods as shown on the UML diagram, using object-oriented
methods, but which does not have the required behaviour in all cases, could receive a grade of
up to 15 if it is implemented cleanly and intelligently.
A submission which satisfies all the requirements described, including passing all the tests, can
achieve any grade up to 20, with the highest grades awarded to implementations that show
clarity of design and implementation, with additional tests that show an insight into the problem.
Any extension activities that show insight into object-oriented design and test-driven development may increase your grade, but a good implementation of the stated requirements should be
your priority.
See the standard mark descriptors in the School Student Handbook:
https://info.cs.st-andrews.ac.uk/student-handbook/learning-teaching/feedback.html#Mark_
Descriptors
Lateness
The standard penalty for late submission applies (Scheme B: 1 mark per 8-hour period, or part
thereof) as shown at:
https://info.cs.st-andrews.ac.uk/student-handbook/learning-teaching/assessment.html#
lateness-penalties
Good Academic Practice
The University policy on Good Academic Practice applies:
https://www.st-andrews.ac.uk/students/rules/academicpractice/
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