Snake – 2023

CSC1002 – Computational Laboratory
Snake – 2023
OVERVIEW
In this assignment, you are going to design and develop a Snake game. The game is composed of 3
objects: a snake, a monster and some food items represented by a set of numbers between 1 and 9. In
the figure shown above, the snake is represented by a sequence of squares where its head and its tail
are displayed in red and black colors respectively, while the monster by a purple square. The numbers
are food items to be consumed by the snake.
The goal of the game is to maneuver the snake within the game area in four directions (up, down, left
and right), trying to consume all the food items while avoiding head-on collision with the monster. As
each food item is consumed, the tail of the snake lengthens in size equal to the value of the number
crossed. While directing the movement of the snake you should avoid contact with the monster.
Furthermore, the monster is also programmed to be motioned in the direction towards the head of the
snake at a variable speed.

The following screens show the initial display of the game (left), the start of the game (middle) after a
mouse click, and the entire snake (right) including the tail.

The following screens show the snake and its extended tail after consumption of two food items (4 on
the left and 3 on the right), while the monster actively chasing after the snake:

The following screen shows the ending of the game after the snake has consumed all food items
including the fully extended tail; shown on the status area are the number of contacts with the monster
and the total elapsed game time in seconds:

The following screen shows the ending of the game where the snake collided head-on with the monster
with some food items left unconsumed:

SCOPE
1. Design the snake game using the standard module “turtle”, including the following components:
a. Game Area (status and motion area)
b. A Snake
c. A Monster
d. Food Items
e. Game Status
f. Controls
g. Motion
2. Game Area
a. The game area is composed of an upper area for statuses and a motion area where the
snake and monster are moved around, surrounded by a fixed margin along the four
sides, with the following dimensions:
i. Upper status area = 500 (w) x 80 (h)
ii. Lower motion area = 500 (w) x 500 (w)
iii. Margins = around 40 pixels
b. Draw a border for both the status area and motion area.
Note: the dimension of the motion area is chosen in multiple of standard turtle shape
(default 20 pixels)
3. Food Items
a. Display 5 food items from 1 to 5 within the motion area in random locations. These
numbers will be kept visible all time until they are consumed by the snake. When the
head of the snake crosses one of these numbers, the number being crossed is
considered consumed and it will be removed from the game area permanently. So, any
one food item can be consumed once.
b. During the game, randomly hide and unhide any unconsumed food items. Use
appropriate random timer rate, say few seconds between 5 and 10, then randomly pick
CSC1002 – Computational Laboratory
CSC1002 – 2023 Winter By Kinley Lam
one of the unconsumed items (including hidden), if the chosen item is visible, hide it, or
unhide it otherwise.
c. Hidden food items cannot be consumed by the snake.
d. Use appropriate font size to show the food items.
e. Align food items to match to the center position of the snake as follows:
4. Font Size
a. For displaying text on the canvas, use appropriate font size such as:
i. Arial, 16, bold or normal
5. Snake
a. The snake is composed of a head with a tail which extends as the snake consumes any
food items.
b. Use only simple, built-in shape “square” for both head and tail, and default size.
c. Use different colors for the head (ex: red) and the tail (ex: black with blue outline color);
choose outline color for the tail so that the length of the tail can be counted easily.
d. The tail extends as the snake moves, not at the point when the food item being
consumed; in other words, at the moment the snake crosses a food item, the snake
doesn’t change in size; as the snake moves the tail extends in the direction of the
movement as if the end of the tail sticks onto the screen. The tail extension ends when
the length of the snake has grown in size equal to the value of the number being
crossed. The following figure shows the sequence of moves of the snake crossing a food
item.

e. As the tail is being extended, the movement of the snake will slow down. See “Timer”
below.
f. At the start of the game, the length of the tail is set to 5. One square shape counts as
one unit length, so the tail will be composed of 5 square shapes when fully extended.
6. Monster
a. A fixed size object to be programmed to move towards the snake, trying to make a
head-on collision.
b. On startup, place the monster on a random position with a fair distance from the snake.
c. The monster should move at a random rate, a rate that is slightly faster or slower than
that of the snake. See “Timer” below.
d. Use only simple, built-in shape “square” for the monster, default size.
e. Use a different color such as purple.
f. Set the initial position of the monster such that the shape of the monster will partially
overlap the shape of the snake when contacted, shown as follows:
7. Game Status
a. Show the motion of the snake (Left, Right, Up, Down, Paused), in other words, the last
motion key pressed (including the space bar), regardless of whether the snake is in
motion or being blocked.
b. Show the total count of body contact of the snake with the monster. The count should
be based on the motion of the monster timer. Each time the monster is re-positioned, it
should then check if it overlaps with any part of the snake.
c. Keep track of the total elapsed game time in seconds. The time counter starts as soon
as the game starts and will stop only when game is over. In other words, the counter
will not be stopped when the snake is being paused.
8. Motion via Timer
a. “Timer” controls the frequency that a specific event to take place at a regular interval, in
this case the event is the movement of either the snake or the monster.
b. Use separate timers to manually refresh the movement of both snake and the monster
i. Turn off the built-in automatic screen refresh
c. Set an appropriate timer rate, say no faster than 0.2 second.

d. On each timer event, always advance the snake or the monster in a distance equivalent
to the length of the turtle shape (square). If the square’s dimension is 20x20 (pixels),
then your logic should advance the turtle object 20 pixels at a time.
e. Both snake and monster move in four directions, left, right, up or down, NOT diagonally.
f. Design the timers in such a way:
i. the monster should move in a random time range slightly above or lower than
that of the snake, while snake always move at a fixed rate.
ii. when the snake crosses a food item (a number) slow down its movement by
increasing its timer rate until its tail is fully extended, that is, the snake will
motion slower while the tail being extended
iii. furthermore, you don’t want the snake to move too fast that the monster will
never catch up with the snake, or vice versa. That is, you don’t want the
monster moves so quickly that it always catch the snake before it has a chance
to consume all the food items.
9. Controls
a. Use the four arrow keys (Up, Down, Left, Right) to maneuver the snake in Up, Down,
Left and Right motion respectively.
b. The motion will continue in the direction of the last arrow key pressed. For an example,
If Left key is pressed, the snake will continuously move in the left direction until a
different arrow key is pressed.
c. Use “Space Bar” to toggle (pause and un-pause) snake motion (note: monster never
pause). While in motion, pressing the spacebar will pause the snake (not the monster).
While paused, pressing the space bar the snake will resume motion in the direction of
the last arrow key pressed. Furthermore, while paused, pressing any of the four arrow
keys will un-pause the snake motion and move in the direction of the arrow key being
pressed.
d. Both snake and monster cannot move beyond the motion area; when the head of the
snake is moved against any of the 4 sides, the snake will be stopped and it will remain
blocked until its heading is changed away from the edges including its tail.
e. Snake CANNOT cross itself, left to right, up to down or vice versa.
f. Timer for the game will never be paused.
10. Game Termination
a. The game ends when the snake consumes all the food items and its body is fully
extended, in this case “Winner” or the monster caught the snake, in this case “Game
Over”.


11. Game Startup
a. On startup, show (1) a brief reminder on how the game starts, (2) the snake (in red)
positioned at center and (3) the monster (purple) at a random position far enough from
the snake.
b. User mouse-click anywhere on the screen to start the game, all the food items will be
shown subsequently, user then moves the snake around using the 4 arrow keys
CSC1002 – Computational Laboratory
CSC1002 – 2023 Winter By Kinley Lam
12. Coding Styles
a. Ensure that your program follows the proper layout structure as discussed in class.
b. You might declare many global variables used for this assignment, ensure that a
consistent naming convention is in place to differentiate various variable scopes.
NOTE:
• Keep your entire source code in ONE SINGLE file.
• Use only standard python modules
• In your design stick ONLY to functions, in other words, no class objects of your own.

STARTUP OPTIONS
Not applicable

SKILLS
In this assignment, you will be trained on the use of the followings:
• Use built-in turtle module to design the snake program as per scope
• Use standard objects (strings, numbers & lists)
• GUI interaction, asynchronous events, timer.
• Variable Scope
• Functions for program structure and decomposition
DELIVERABLES
1. Program source code (A3_School_StudentID_Source.py)
where School is SSE, SDS, SME, HSS, FE or LHS and StudentID is your 9-digit student ID.
Submit the python file by due date to the corresponding assignment folder under “Assignment
(submission)”
For instances, a SME student with student ID “119010001” will name the program as follows:
• A3_SME_119010001_Source.py:
5% will be deducted if file is incorrectly named!!!

TIPS & HINTS
• Follow the layout structure as mentioned in class (import, declarations, functions, main
process).
• Be consistent with naming convention of variable scope
• Refer to python website for program styles and naming convention (PEP 8).
• Use Turtle() as objects for the snake, monster and all food items.
13. Use the shape() function to set the shape for your objects, or pass the shape as string to the
Turtle(). Note: use simple, built-in shape such as “square” for your snake and monster objects.
Complex shapes will slow down the screen refresh!!!!
14. Use stamp() to make copy of the turtle shape at its current position; use clearstamp(idx) to
remove a specific stamp copy or clearstamps() to clear one or more stamp copies.
• Use “stampItems” of the Turtle object to return the list of turtle stamps
• Use write() to display a text on the screen via turtle object.
• Remember to set the pen in “up” position to avoid line drawing.
• Use ontimer() to motion your snake and monster.
• Use Screen() to configure the game area and use onclick() to capture mouse-click event.
• Use tracer(0) to disable auto screen refresh and call update() to manually refresh the game area.
• Refer to https://docs.python.org/3/library/turtle.html for more information on Turtle Graphics.

SAMPLE OUTPUT
Refer to the Overview session.


CSC1002 – Computational Laboratory
CSC1002 – 2023 Winter By Kinley Lam
MARKING CRITERIA
• Coding Styles – overall program structure including layout, comments, white spaces, naming
convention, variables, indentation, functions with appropriate parameters and return.
• Design Documentation if required
• Program Correctness – whether or the program works 100% as per Scope.
• User Interaction – how informative and accurate information is exchanged between your
program and the player.
• Readability counts – programs that are well structured and easy-to-follow using functions to
breakdown complex problems into smaller cleaner generalized functions are preferred over a
function embracing a complex logic with nested conditions and sub-functions! In other words, a
design with clean architecture with high readability is the predilection for the course objectives
over efficiency. The logic in each function should be kept simple and short, and it should be
designed to perform a single task and be generalized with parameters as needed.
• KISS approach – Keep It Simple and Straightforward.
• Balance approach – you are not required to come up a very optimized solution. However, take a
balance between readability and efficiency with good use of program constructs.
ITEMS PERCENTAGE REMARKS
CODING STYLES 15%-20% 0% IF PROGRAM DOESN’T RUN
USER INTERFACE 15%-20% 0% IF PROGRAM DOESN’T RUN
FUNCTIONALITY MAX. 70% REFER TO SCOPE
DUE DATE
April 23th, 2023, 11:59:59PM

CSC1002 – Computational Laboratory
CSC1002 – 2023 Winter By Kinley Lam
OTHER IDEAS:
If you feel that you have the passion for programming, here’s list of other ideas that you could further
enhance your program by refactoring your existing logic.
1. Implement multiple monsters; start with one monster initially and then another one on every
fixed time interval, up to some numbers, say 3 (be cautious not to have too many monsters
suddenly). You need to ensure that use a different timer logic to for each monster chasing after
the snake. Otherwise all monsters will merge into each other eventually and moved altogether.
2. Randomly hide and unhide any food items.
3. Randomly shift any food items; shift food items in random direction (left, right, up or down), not
too much a shift, yet enough to confuse the player
4. Do not allow the snake to cross its body; block its movement
5. Implement surprise items; you can have reward or penalty items on screen for snake to
consume:
a. Reward: Increase game time limit (20 seconds)
b. Reward: Freeze motion of all monsters for a few seconds (10 seconds)
c. Penalty: generate another food item
d. Penalty: Hide all food items for a few seconds (10 seconds)
6. Add sound effect (motion, body contact, food consumption, surprise items and so on).
7. Set aside the top portion of the game area for better status display (with larger text size and
different colors)
8. Set a time limit; player must finish the game within the time limit
9. Add prompt for a new game
Further challenges: After you submit your assignment, leave the program alone and wait until the end of
the school year, around end July, then start the development. You will see the value of refactoring and
decomposition. Share me your experiences on your development.
NOTE:
• Please DO NOT IMPLEMENT ANY OF THESE FEATURES with your assignment except those
items mentioned in Scope section.
• No extra credit will be given
• Remember to show your game objectives, or include a readme.txt file
• Share your program to me by email
• If you come up with other ideas share them with me as well
• Enjoy programming