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 48x48 pixels, so the total is 672x672 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 792x672.
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
The config file is in located in config.json in the root
directory of the project. Use the simple json library to
read it. Sample config and level files are provided in the
scaffold.
The config sample as shown to the left, contains the
name of the layout file. This is also located in the root
directory of the project. The layout file will contain a
grid of text characters, where each character
represents the piece that should be in that cell.
Uppercase characters are for black, and lowercase are
for white. See the table below.
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
If after a move, a king is under attack, the king is said to be in ‘check’.
Under this circumstance, the player whose king is in check must do one
of the following (all must already be legal moves):
• 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’)
Illegal moves due to check or pins should not be highlighted as blue tiles
when selecting a piece to potentially move it – only legal moves should be
highlighted.
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
Figure 12: The black king is in check due to the white chancellor. Black
cannot move their king, their only option is to move their General or
Amazon to block (assuming there is no piece off-screen that can capture
the white chancellor).
Figure 13: The selected pawn is pinned by the archbishop, so cannot move. However
if the archbishop was one space closer to it diagonally, then the pawn would be able
to capture the archbishop but not move straight forward. If the king was on the
square one space below where it currently is, then the camel would be pinned by the
bishop.
• 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 672x792
• 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.
Figure 14: The white king is checkmated. The
contributing pieces are the archbishop and two pawns.
• 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 ingame
• 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.
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.
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.