INFO1113 / COMP9003 Assignment
Due: 14 May 2023 , 11:59PM AEST
1 | This assignment is worth 1 8 % of your final grade. |
Task Description
In this assignment, you will create a game in the Java programming language using the Processing library
for graphics and gradle as a dependency manager. In the game, the player must be able to move chess
pieces on a chess board in order to play against an AI, ultimately capturing the opponent’s pieces and
executing a strategy to checkmate the opponent’s king.
You have been given the task of developing a prototype of the game. A full description of gameplay
mechanics and entities can be found below. An artist has created a simple demonstration of the game
and has posted it on your online forum (Ed). You can also play a similar game here.
You are encouraged to ask questions on Ed under the assignments category if you are unsure of the
specification – but staff members will not be able to do any coding or debugging in this assignment for
you. As with any assignment, make sure that your work is your own, and do not share your code or
solutions with other students.
Working on your assignment
You have been given a scaffold which will help you get started with this assignment. You can download
the scaffold onto your own computer and invoke gradle build to compile and resolve dependencies. You
will be using the Processing library within your project to allow you to create a window and draw
graphics. You can access the documentation from here.
Gameplay
The game contains a number of entities that will need to be implemented within your application.
Board
The board consists of a grid of tiles 14x14. Each tile is 48 x 48 pixels, so the total is 672 x 672 pixels.
However, there are 120 pixels on the right sidebar reserved for information such as timers showing the
number of minutes and seconds remaining on each player’s clock, and warnings or other messages for the
user. The window size is therefore 792x 672.
The board is arranged in a checkerboard pattern as below with alternating black and white tiles. These are
fixed and do not change. Pieces sit atop these tiles, and the tiles may change colour shade to indicate
highlights for particular reasons.
There are 4 main types of highlights:
- Blue – the player clicked on a piece, and it is able to move to this square.
- Light red – the currently selected piece can move to this square, capturing the current piece there
- Green – the player’s currently selected piece
- Yellow – the last piece to move, and the square it came from
- Dark red – the king on this square is currently in check, or checkmate has occurred (pieces that
contribute to the checkmate are highlighted in light red)
The initial piece layout is defined in a file named in the “layout” attribute of the JSON configuration file
described below.
Config
1 | The config file is in located in config.json in the root |
1 | The config sample as shown to the left, contains the |
Empty spaces are empty tiles. All maps used for marking will be valid, but you should write your own tests
for invalid maps and handle them as you see fit.
The “time_controls” section contains the amount of time to be given to player 1 and player 2 (player 2 is
the computer - cpu). Seconds it the total time they start with, which is consumed while they are thinking
about a move. The “increment” is a number in seconds added to their remaining time once they make a
move.
The “player_colour” property denotes the colour of the pieces of player 1 (the human player). It should
either have the value “white” or “black”. If player 1 is white, then player 2 is black. If player 1 is black,
then player 2 is white. Whoever is white has the first move, as in regular chess.
Layout file See page 5 for images of movement
Black White Chess piece Value Sprites Movement
P p Pawn 1 One space forward. Captures
diagonally only. If blocked, cannot
move.
R r Rook 5.25 Horizontally and vertically.
N n Knight 2 2 squares vertical, 1 horizontal, or
vice versa
B b Bishop 3.625 Diagonally in any direction.
H h Archbishop 7.5 Like Knight + Bishop
C c Camel 2 3 squares vertical, 1 horizontal, or
vice versa
G g General/Guard 5 Like Knight + King
A a Amazon 12 Like Knight + Bishop + Rook
K k King ∞ 1 space in any direction. Cannot
move into danger.
E e Chancellor 8.5 Like Knight + Rook
Q q Queen 9.5 Like Bishop + Rook
Movement
The “piece_movement_speed” property in the config denotes how fast in pixels per frame a piece move
should occur. This is limited by the “max_movement_time”, a number in seconds that the movement
time should not exceed. If the movement would exceed this amount of time, the speed is increased to
ensure it doesn’t take longer. Moves occur at a constant speed, with the chess piece smoothly
transitioning in a straight line from its original position to its new position.
To trigger a move, the player must first select a piece by clicking on the cell it’s located in. Then, click to
the cell the piece should move to. If the player instead selects one of their other pieces, then that piece
becomes selected instead. If the player clicks on the selected piece again, or an invalid move, it becomes
unselected.
Normal movement of pieces is described in the table above. The king, queen, bishop, knight, rook and
pawn all have the same movement as in regular 8x8 chess. For the purposes of pawn movement,
“forward” is considered going up the board for the human player, and going down the board for the
computer player.
In addition, be mindful of the following special moves.
Special moves:
- A pawn can move two squares forward if it is located on 2nd row from the top or bottom of the
board (rank 2 and rank 13), and has not moved before. - A king may perform a ‘castling’ move if it has not moved before, which allows it to move two
squares horizontally in either direction so long as there is also a rook towards the direction it will
move (on the same rank), and that rook hasn’t moved. When this move is performed, the rook is
placed on the other side of the king, adjacent to it. - Pawn promotion: When a pawn reaches the 8th rank (ie. when it crosses the halfway point on the
14x14 board), then it is promoted to a queen. It immediately turns into a queen and can be used
as such in all subsequent moves
Only a camel or knight move may jump over pieces (or the rook when castling), and a player may not
move a piece onto a cell already containing one of their own pieces. If a move causes the piece to enter a
tile containing one of the opponent’s pieces, the opponent’s piece is ‘captured’ and removed from the
board. All pieces capture on the same tiles as their regular movement, with the only exception being
pawns which capture diagonally forwards instead, if there is a piece there. This is the only time they are
allowed to move diagonally. If there is a piece directly in front of a pawn, it is blocked and cannot move to
the cell occupied by that piece.
Examples of possible moves for each piece are shown below.
Figure 1 : Archbishop movement
Figure 2 : Amazon movement
Figure 3 : Bishop movement
Figure 4 : General/Guard movement
Figure 5 : Camel movement (^) Figure 6 : Rook movement^
Figure 7 : Knight movement
Figure 8 : King movement. The king cannot
move to squares controlled by an
opponent’s piece.
Figure 9 : Chancellor movement. The camel
and generals block movement in the left
direction, but knight moves can still jump
over (same for other knight combinations).
Figure 10 : Pawn movement. The pawn
can only move diagonally when
capturing and cannot move directly
forward if blocked.
Figure 11 : Queen movement
Check and Checkmate
1 | If after a move, a king is under attack, the king is said to be in ‘check’. |
- Move their king to a safe square
- Move a piece to block the attack
- Capture the attacking piece
This is because otherwise, the player would lose their king on the next turn, and therefore lose the game.
If none of these possibilities are available, then the player has been checkmated – there is no move
available to them that would save their king, and they have lost.
When check occurs, the king’s square is highlighted in dark red, and the message “Check!” appears in the
right sidebar. If a player attempts to make an otherwise legal move that doesn’t protect their king, display
a message on the right sidebar: “You must defend your king!”, and the highlighted cell the king is on will
flash 3 times with a duration of 0.5 seconds each.
A player cannot make a move that would result in their king coming under attack. This could be any of
either:
- Moving the king to a square which is under attack by the opponent
- Moving a piece that is blocking an attack on their king by the opponent (this piece is said to be
‘pinned’)
1 | Illegal moves due to check or pins should not be highlighted as blue tiles |
Computer AI movement
The way the computer player determines moves is up to you. It can be as simple as choosing a move
randomly out of all available legal moves. However, you should try and make it at least a bit intelligent.
For example, here is guidance on some basic rules you might want to have:
- Capture a piece if the piece’s value is higher than the capturing piece, and if multiple such options
exist, choose the one with the highest difference
1 | Figure 12 : The black king is in check due to the white chancellor. Black |
1 | Figure 13 : The selected pawn is pinned by the archbishop, so cannot move. However |
- If a piece is threatened to be captured by a piece of lower value (or any piece if the threatened
one is undefended), move it - Prefer to only move to squares that are not under attack by a piece of lower value (or even a
piece of higher or equal value if the square is undefended) – let’s call these ‘safe squares’ - If possible, attack the opponent’s king or a square adjacent to it if it’s not already under attack
- If possible, checkmate the opponent’s king
- If all else fails, choose a random move (prefer safe squares, but it’s possible none may be
available)
Win and lose conditions
The game ends when either one player runs out of time, or their king is checkmated. Then other player
wins.
If the human player wins by checkmate, display a message saying “You won by checkmate” in the right
sidebar. If the human player wins due to the timer, display instead “You won on time”.
If the human player loses by checkmate, display a message saying “You lost by checkmate” in the right
sidebar. If instead the cause was the timer, display “You lost on time”.
The player can also resign the game by pressing ‘e’ on the keyboard. The game ends and the message
“You resigned” is displayed in the right sidebar.
When the game ends, the board remains intact and
frozen so that the player cannot make any moves
(but may restart the game with the key press ‘r’). If
checkmate occurred, the board should highlight the
king of the checkmated player in red and the pieces
contributing to checkmate in orange. Pieces
contributing to checkmate are defined as a piece that
is either attacking the king or one of the empty
squares adjacent to it, or defending a piece that the
king could otherwise capture. For each such square,
there should only be one piece highlighted.
If there are no legal moves for a player, then the
game is considered a draw and enters the end state.
Display the message “Stalemate – draw”.
Application
Your application will need to adhere to the following specifications:
- The window must have dimensions 672x
- The game must maintain a frame rate of 60 frames per second.
- Your application must be able to compile and run on any the university lab machines (or Ubuntu
VM) using gradle build & gradle run. Failure to do so, will result in 0% for Final Code Submission. - Your program must not exhibit any memory leak.
1 | Figure 14 : The white king is checkmated. The |
- You must use the processing library (specifically processing.core and processing.data), you cannot
use any other framework such as javafx, awt or jogl
You have been provided a /resources folder which your code can access directly (please use a relative
path). These assets are loadable using the loadImage method attached to the PApplet type. Please refer
to the processing documentation when loading and drawing an image. You may decide to modify these
sprites if you wish to customise your game. You will be required to create your own sprites for any
extensions you want to implement.
Extension
The extension is worth 2 marks maximum. For an extension, you can choose to implement one of the
following:
- New piece type with different movement and/or special behaviour
- Start menu to select options without having to change the config file
- More complex computer AI (specify difficulty in config?)
- Option for 2-player in config (two human players)
- Option for fog of war chess in config (Tiles not able to be moved to are greyed out. The only
pieces of the opponent’s that are visible are those which are present on tiles available to be
moved to. Game ends upon king capture.) - Sound effects
- Expandable resizable board (drag corners to change game resolution)
- More pawn promotion options rather than just promote to queen – user can choose while in-
game - Allow pre-moves (and/or drag and drop pieces rather than just click to move)
- Allow different types of new configurable pieces (combinations) within the json config file, and
what their symbol would be in the layout - Multiple levels specified in the config for the purpose of solving chess puzzles / problems.
1 | OR, a feature you come up with which is of a similar or higher level of complexity (ask your tutor) |
Please ensure you submit a config and level layout file with the features of your extension, and ensure the
extension doesn’t break any of the default behaviour. Also, describe your extension functionality in the
report.
Marking Criteria (18%)
Your final submission is due on Sunday 14 May at 11:59PM. To submit, you must upload your build.gradle
file and src folder to Ed. Please also include sample config and layout files that you have tested with your
program to ensure it works. Do NOT submit the build folder (unless you only include the build/reports/
folder which contains the results of your testing and code coverage). Ensure src is in the root directory
with the other files, and not part of a zip, then press MARK. Submit your report and UML to canvas.
A demo of your assignment will be conducted during labs in week 12 where you will demonstrate the
features you have created to your tutor.
Final Code Submission and Demo (10%)
You will need to have implemented and satisfied requirements listed in this assignment. Make sure you
have addressed the following and any other requirements outlined previously.
- Window launches and shows checkerboard pattern.
- Configuration file is correctly read in – timers display correctly
- Map loads and pieces are displayed in correct positions
- Piece colour for player and computer is correct
- Pieces are controlled by mouse clicks
o A piece can be selected – green highlight appears
o Potential moves show in blue highlights, or red for potential captures
o Clicking on a highlighted blue/red cell cause the selected piece to move to that location
o Captured pieces are deleted properly - Pieces move correctly according to the table of their movement
- Piece movement – is smooth and correct speed
- If a move causes the opponent’s king to come under attack, display “Check!” and highlight the
king’s tile in dark red. - While the king is in check, only moves to save the king are allowed:
o Capture the attacking piece
o Move a piece to block
o Move the king to a safe square - A move that causes your own king to be in check is not allowed:
o Moving the king to a square that is under attack
o Moving a pinned piece that was blocking an attack on the king - Special moves: Pawn can move two squares initially, Castling, Pawn promotion to queen on the
8 th rank (ie. when passing the halfway point) - Computer AI moves automatically after the player makes their move
- Computer AI only makes legal moves
- Game ends if either player runs out of time – message is displayed correctly
- Game ends if either player is checkmated – message is displayed correctly
- Pieces contributing to checkmate have their tiles highlighted in red
- Player can resign if they want to by pressing ‘e’
- Timer counts down and increments according to config after a move is made
- Ensure that your application does not repeat large sections of logic
- Ensure that your application is bug-free
Testcases (3%)
During development of your code, add testcases to your project and test as much functionality as
possible. You will need to construct unit test cases within the src/test folder using JUnit. To test the state
of your entities without drawing, implement a simple loop that will update the state of each object but
not draw the entity.
Ensure your test cases cover over 90% of execution paths (Use jacoco in your gradle build) Ensure your
test cases cover common cases. Ensure your test cases cover edge cases. Each test case must contain a
brief comment explaining what it is testing. To generate the testing code coverage report with gradle
using jacoco, run “gradle test jacocoTestReport”.
Design, Report, UML and Javadoc ( 3 %)
You will need to submit a report that elaborates on your design. This will include an explanation of any
object-oriented design decisions made (such as reasons for interfaces, class hierarchy, etc) and an
explanation of how the extension has been implemented. This should be no longer than 500 words. This
report will be submitted through Canvas.
You will need to submit a UML diagram in PDF form to Canvas to provide a brief graphical overview of
your code design and use of Object Oriented Principles such as inheritance and interfaces. Markers will
use this to determine whether you have appropriately used those principles to aid you in your design, as
well as figure out whether more should have been done. A general guideline is that markers will be
looking for some use of inheritance or interfaces, how extensible the code is, and penalising repeated
code. Note that you should not simply use a UML generator from an IDE such as Eclipse, as they typically
do not produce diagrams that conform to the format required. We suggest using software such as
LucidChart or draw.io for making your diagrams.
Your code should be clear, well commented and concise. Try to utilise OOP constructs within your
application and limit repetitive code. The code should follow the conventions set out by the Google Java
Style Guide. As part of your comments, you will need to create a Javadoc for your program. This will be
properly covered in week 11 but the relevant Oracle documentation can be found here.
Report, UML and OO design: 2%
Javadoc, comments, style and readability: 1 %
Extension (2%)
Implement an extension as described above. Partial marks may be awarded if you choose a more limited
extension or it is partially completed. Please specify what extension you decided to implement within
your report.
Suggested Timeline
Here is a suggested timeline for developing the project. Note that it is released on April 3 (start of week 7 )
and due May 14 (end of week 1 1 ).
Week 7 : Familiarise yourself with gradle and processing, utilising the processing Javadoc and week 8
supplementary lecture. Identify opportunities to utilise Object Oriented Design principles such as
inheritance and interfaces and begin to plan a design for the codebase with regards to the classes that
you will need to make. Make a rough UML diagram for your design that you can base your codebase from.
Week 8: Begin writing the actual code for the program. Start small, for example by initially creating the
board layout and pieces, then gradually add more elements. At the end of the week, you should have
loading in the board and piece movement finished, as well as some sprite management. If confident, use
Test Driven Development (writing test cases at same time as writing the code). Conduct a large amount of
user testing to ensure the initial mechanics work as expected.
Weeks 9 - 10 : Develop more gameplay features, such as check, checkmate, special moves, and the
computer AI. Sprite management should be streamlined at this point. You should have a fairly high code
coverage for your test cases at this stage. If you are noticing any questionable design decisions, such as
God classes or classes that are doing things they logically should not be doing, this is the time to refactor
your code. Think about what extension you want to make and start to implement it.
Week 11 : Finish developing the remaining features for your program, notably the configuration file, and
timers. Additionally, finish writing your testing suite. Create the UML and Javadoc for the program. Fix any
remaining bugs that your code exhibits. Submit your code to Ed (by uploading the entire project and
pressing MARK) and submit your UML to Canvas in PDF form.
Week 12: Demonstrate the completed program to your tutor during the week 12 lab. They will check each
criteria item has successfully been completed, and may ask you questions about how you implemented it
to test your understanding.
Academic Declaration
By submitting this assignment you declare the following:
I declare that I have read and understood the University of Sydney Student Plagiarism: Coursework Policy
and Procedure, and except where specifically acknowledged, the work contained in this
assignment/project is my own work, and has not been copied from other sources or been previously
submitted for award or assessment.
I understand that failure to comply with the Student Plagiarism: Coursework Policy and Procedure can lead
to severe penalties as outlined under Chapter 8 of the University of Sydney By-Law 1999 (as amended).
These penalties may be imposed in cases where any significant portion of my submitted work has been
copied without proper acknowledgment from other sources, including published works, the Internet,
existing programs, the work of other students, or work previously submitted for other awards or
assessments.
I realise that I may be asked to identify those portions of the work contributed by me and required to
demonstrate my knowledge of the relevant material by answering oral questions or by undertaking
supplementary work, either written or in the laboratory, in order to arrive at the final assessment mark.
I acknowledge that the School of Computer Science, in assessing this assignment, may reproduce it
entirely, may provide a copy to another member of faculty, and/or communicate a copy of this assignment
to a plagiarism checking service or in-house computer program, and that a copy of the assignment may be
maintained by the service or the School of Computer Science for the purpose of future plagiarism checking.