CITS1001 PROJECT 2 Board Game - Tigers & Goats
Board Game - Tigers & Goats
In this Java project, you will implement a very basic board game that allows a human player to play
against the computer. You will use SimpleCanvas to display the board as the game progresses. To complete
the project, first read and understand the problem specification in the next section. Then study the
specification of project classes to understand how your implementation is to be structured.
A video of the game play (from the project solution) is provided on LMS.
3 Problem Description
Tigers & Goats is a simple game where one player controls 12 goats to trap 3 tigers to win i.e. the tigers
are unable make a valid move. The second player controls tigers to make simple moves or to jump over a
goat to eat it and reduce their numbers. Tigers win when the number of goats becomes less than 6, since
this is the minimum number required to trap all tigers. However, as the number of goats reduce from 12,
their chances of wining diminish rapidly. Figure 1 shows a snapshot of game play in stage 2. The circles
represent goats and the squares represent tigers. One of the goats has been eaten and hence there are
11 goats. Goats and tigers can move to an adjacent location connected by a straight line (red or white,
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colour is only for cosmetic reasons). Valid locations (where a goat or tiger can be placed) are the corners
or intersection of lines.
A tiger can jump over a goat in a straight line to the next location and eat the goat in its way. The
destination location must be vacant for this to happen. In Figure 1, tiger 1 can jump over the goat to its
left as shown by the arrow. The goat in the way will be eaten and removed from the board. Tiger 2 is
blocked. It can neither move nor jump over (eat) any goat since there is no destination location to the
left, right or top and the bottom one is occupied by a goat. Goats can move to save themselves or their
fellow goats by occupying a location. Tiger 3 can eat the goat on its right.
The game starts with an empty board. In the first phase, players place their pieces only. Player one
(human) places 4 goats and then player two (computer) places 1 tiger. This process continues until 12
goats and 3 tigers have been placed on the board. Moving a piece is not allowed in this phase. In the
second phase, pieces can be moved only and no more pieces can be added to the board. Players take
one turn at a time from now on. Goats try to block the tigers and tigers try to avoid being blocked and
eat goats. You are required to complete the Java classes so that a human player can play against the
computer. The game should allow a human player to control the goats and should not allow the human to
make an illegal move. The game should automatically control the tigers implementing a simple strategy
to win. This is not that difficult since the computer controls more powerful pieces i.e. the tigers. All it
has to do is to not miss any chance of eating a goat.
4 Specification of Project Classes
In Figure 3, I have made a simple 2-D coordinate system for the board using a fixed block size. Each
corner or intersection of lines (called a location) is where a piece can be placed or moved to. Note that
not all coordinates are valide locations e.g. there is no 1,2 or 1,3 location on the board to place a piece.
There are 24 valid locations ([0] to [23]) that have been arranged in a 1-D array that start from the top
left and spirals inwards anti-clockwise. The 2-D coordinate system simplifies drawing of the board and
pieces. The 1-D array representation of the board simplifies maintaining the location of pieces (tigers and
goats), deciding which moves are legal and which jumps (eats) by tigers are legal.
The project is divided into 5 classes. One of them is SimpleCanvas which is provided to you. You do not
need to edit this class.
1. GameViewer: This class controls the drawing of the board and game play. It implements a mouse
listener to allow to human player to place goats and then to move them. It also checks that the
game rules a followed with the help of the GameRules class. It uses the Board class to maintain the
status of the board and the AIplayer class to make the tiger moves. GameViewer also declares the
winner of the game.
2. Board: This class maintains and updates the status of the board i.e. the locations of the tigers and
goats using a simple 1-D array of size 24 representing the valid locations of the board. This class
has accessor and mutator methods to query or alter the board at a specific location.
3. GameRules: This class maintains the game rules (legal or illegal moves), turns (goats turn or tigers
turn) and game stage (placement or movement of pieces). It also computes the nearest valid location
to a mouse click.
4. AIplayer: This class controls the tigers aiming to eat a goat whenever possible. Otherwise, it makes
a simple legal move or declares that it is unable to move any tiger.
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Figure 1: Snaptshot of game play in the second stage where pieces can be moved only. Note that tiger 1
and 3 can eat a goat as shown by the arrow and tiger 2 is blocked.
You can choose your own colour scheme for the board, lines, pieces and text as long as they are visible.
Further details on the functionality of the classes and their methods can be found the skeleton code provided
as a zip file.
No JUnit test classes will be provided as you can test your code visually by playing the game. For example,
the goats should be placed so that they are exactly centred on the valid locations as long as the click was
in the vicinity of the location, it should not be possible to place a piece on top of another, the turns should
follow the game rules, the movement of goats/tigers should follow the game rules and so on.
4.1 Creativity
It is best to implement the required functionality first. If you have time and wish to extend your knowledge
of Java, then you are encouraged to extend this project. A few suggested extensions are below:
? Blink the goat a few times before it disappears from the board after being eaten.
? Make the placement of the tigers more strategic rather than random.
? Animate the movement of goats and tigers instead of sudden disappear and reappear.
? Allow the human to choose and play tigers instead of goats. Implement an automatic player class
that places the goats and then moves them strategically to block the tigers and avoid being eaten.
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Figure 2: Snaptshot of game play where the goats have won by blocking all tigers. The tiger can neither
move nor eat any goat.
You can also identify and complete additional functionality as you wish. There are 30 marks for additional
functionality. These are not easy to get marks. If you implement all of the above and the goats can beat
a casual human player, you will get all 30 marks. However, these marks can only make up for marks that
you have lost in this project or elsewhere. You cannot get over 100 marks in this unit.
5 Project Management Tips
Before starting the project, students are expected to have
? studied the lectures and the relevant chapters of the text,
? completed the assigned labs during Weeks 2-9,
? read and understood the whole of this project description,
? read and understood all relevant UWA policies.
The Game of Life lecture and the Fifteen Puzzle lab will be helpful.
It is recommended that you tackle the project tasks in the order indicated; that you compile frequently;
and that you test and run the code after completing each method, to ensure your code behaves as you
think it ought. If you are stuck on a method, it is often a good idea to look in the lecture material, text
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Figure 3: The board is represented by a 2D coordinate system using steps of block size. The top left
corner is 0,0 and the bottom right corner is 8,8. Not all coordinate locations are valid. For example, 1,2
is not a valid location to place a piece. There are 24 valid locations on the board.
book or lab solutions.
You can gain good marks even if you do not complete all the methods, so long as the code you have written
compiles and runs correctly. But if you submit a large body of code that does not compile or that crashes,
then few marks can be awarded.
5.1 Help
Timetabled lab sessions will run as usual during the project weeks and facilitators will be available to help
you at any of the lab sessions per week (see the CITS1001 timetable for lab time details). Remember this
project is to be done in pairs. Besides your project partner, you may discuss with the facilitators and
other students the general principles required to understand this project, but the Java code you submit
must be the result of your own effort (the two team members). Suspected academic misconduct will be
referred to the Academic Conduct Advisor for formal review.
Post any questions or requests for clarification to help1001 but do not post any project code on help1001.
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5.2 Hints and Tips
Hints and tips about the various methods may be uploaded here from time to time. Whenever that happens,
the document version number will be updated.
1. In addition to following the TODO sequence, try to implement one functionality, from game play
point of view, at a time. For example, placement of goat, placement of tiger, movement of goat
(legal or illegal move), make a simple tiger move (legal of illegal), allow only legal moves and test if
all tigers are blocked.
2. You may need to implement a simpler version of a complicated method first and then revisit that
method to add more functionality.
3. The formula for calculating the distance between two points (x1, y1) and (x2, y2) is
d =
q
(x1 ? x2)
2 + (y1 ? y2)
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