def test_snake_collision_while_growing_and_moving(self):
"""
A Snake instance will be created at given coordinates.
It will then be moved in a pattern. After each movement,
a inside_bounds test will be conducted.
"""
snake = Snake((30, 30), (30, 30), (0, 0, 0))
expected_results_inside_bounds = [
True, True, True, True, True, True, False, False, True
]
expected_results_collision_with_self = [
False, False, False, False, False, False, False, False, True
]
test_vector = [
Snake.move_up, Snake.move_right, Snake.move_down, Snake.move_down,
Snake.move_left, Snake.move_left, Snake.move_down,
Snake.move_right, Snake.move_up
]
for expected_bounds, expected_collision, test_move in zip(
expected_results_inside_bounds,
expected_results_collision_with_self, test_vector):
with self.subTest("Snake.{}".format(test_move.__name__)):
snake.grow()
test_move(snake)
self.assertEqual(snake.inside_bounds((0, 0), (90, 90)),
expected_bounds)
self.assertEqual(snake.check_collision_with_self(),
expected_collision)
def test_snake_check_collision_with_self(self):
"""
This test will create a Snake instance at given coordinates.
A collision with self check will then be conducted.
This check is expected to be false.
"""
snake = Snake((30, 30), (30, 30), (0, 0, 0))
self.assertEqual(snake.check_collision_with_self(), False)
def test_snake_inside_bounds_while_moving(self):
"""
A snake instance will be created at given coordinates.
It will then be moved in a pattern, growing after each movement.
After each movement is done, a collision_with_self check will be conducted.
"""
snake = Snake((30, 30), (30, 30), (0, 0, 0))
expected_results = [
False, False, False, False, False, False, False, False, True
]
test_vector = [
Snake.move_up, Snake.move_right, Snake.move_down, Snake.move_down,
Snake.move_left, Snake.move_left, Snake.move_down,
Snake.move_right, Snake.move_up
]
for expected, test_move in zip(expected_results, test_vector):
with self.subTest("Snake.{}".format(test_move.__name__)):
snake.grow()
test_move(snake)
self.assertEqual(snake.check_collision_with_self(), expected)
class SnakeGame:
"""
A simple structure for a Snake-like game.
Attributes:
-----------------
window : Window
The main window of the game.
Makes sure that the implementation is visible to the user.
snake_size : tuple(int, int)
The size of the snake.
snake : Snake
The controllable snake.
current_movement : Callable
One of the four directional functions from the Snake class.
Saved for convenience and used to call movement on the snake-attribute.
fruit_coordinates : list(int, int)
The positional coordinates of the fruit that the snake is to eat.
fruit_size : tuple(int, int)
The size of the fruit.
running : bool
Used to control the state of the game.
If false, the player has either exited or lost the game.
last_update_time : int
If the difference between this and a clock check is above 150
the method update_movement is called and this attribute
updated.
Methods:
-----------------
handle_keydown(event):
Function to handle user input events incoming from the underlying pygame module.
draw():
Draw the game to the screen.
move_fruit():
Randomly moves the fruit until it does not collide with the snake anymore.
Used after the fruit is picked up.
fruit_pickup():
Used to control if the snake is able to pick up the fruit.
If the snake is able to pick the fruit up, the snake will grow
and the fruit will be moved to a new position.
check_if_inside_window():
Used to control whether the snake is inside the boundaries of
the screen or not. If the snake is not inside the boundaries,
the game is over.
run_game_logic():
The main function used to run the game logic.
Makes sure that all other functions are called as they should.
game_loop():
The entry point of the game.
Clears the screen, runs the game logic, and make sure that the
screen is presented at the end.
update_move():
Function to update the movement and control if the
snake collides with itself.
"""
#pylint: disable=no-member
def __init__(self, background_colour, width, height):
"""Initialize the game. The parameters are passed on to the init function of Window
Parameters:
------------------------------------------
colour : list(int, int, int)
A triple of values between 0 and 255 indicating the r, g, b value of the rectangle
top_left : tuple(int, int)
The x- and y-coordinates for the top left corner of the rectangle
size : tuple(int, int)
The width and height of the rectangle
"""
self.window = Window(background_colour, width, height)
self.snake_size = (30, 30)
self.snake = Snake((width//2, height//2), self.snake_size, (75, 75, 75))
self.current_movement = Snake.move_up
self.fruit_coordinates = (0, 0)
self.fruit_size = (30, 30)
self.running = True
self.last_update_time = pygame.time.get_ticks()
def handle_keydown(self, event):
"""Handle key input from the user.
Check if the key pressed is any of the keys used to control the snake,
that is any of the WASD-keys or the arrow keys, or ESC for quiting the game.
If any of the WASD-keys or arrow keys are pressed, change direction of the snake
to the appropiate direction.
Parameters:
event : pygame.event
An event containing a pressed key.
"""
pressed_key = event.key
if pressed_key in (pygame.K_a, pygame.K_LEFT):
self.current_movement = Snake.move_left
elif pressed_key in (pygame.K_d, pygame.K_RIGHT):
self.current_movement = Snake.move_right
elif pressed_key in (pygame.K_w, pygame.K_UP):
self.current_movement = Snake.move_up
elif pressed_key in (pygame.K_s, pygame.K_DOWN):
self.current_movement = Snake.move_down
elif pressed_key == pygame.K_ESCAPE:
self.running = False
def draw(self):
"""Makes sure all the components of the game are presented on the screen."""
self.window.draw_rect(
(255, 0, 0),
self.fruit_coordinates,
self.fruit_size
)
for part in self.snake:
coordinates = part.get_coordinates()
size = part.get_size()
colour = part.get_colour()
self.window.draw_rect(
colour,
coordinates,
size
)
def move_fruit(self):
"""
Randomly moves the fruit until it does not collide with the snake anymore.
Used after the fruit is picked up.
"""
while True:
screen_size = (self.window.width(), self.window.height())
new_x = randrange(0, screen_size[0] - self.fruit_size[0], self.fruit_size[0])
new_y = randrange(0, screen_size[1] - self.fruit_size[1], self.fruit_size[1])
self.fruit_coordinates = (new_x, new_y)
position_ok = True
if self.snake.check_collision(self.fruit_coordinates, self.fruit_size):
position_ok = False
if position_ok:
break
def fruit_pickup(self):
"""
Used to control if the snake is able to pick up the fruit.
If the snake is able to pick the fruit up, the snake will grow
and the fruit will be moved to a new position.
"""
if self.snake.check_collision_with_fruit(self.fruit_coordinates, self.fruit_size):
self.move_fruit()
self.snake.grow()
def is_inside_window(self):
"""
Used to control whether the snake is inside the boundaries of
the screen or not. If the snake is not inside the boundaries,
the game is over.
Return: bool
True: Inside window
False: Not inside window
"""
screen_size = (self.window.width(), self.window.height())
if self.snake.inside_bounds(
(0, 0),
(screen_size[0] - self.snake_size[0],
screen_size[1] - self.snake_size[1])):
return True
return False
def update_move(self):
"""
Function to update the movement and control if the
snake collides with itself.
Called through a pygame registered event.
"""
self.current_movement(self.snake)
if self.snake.check_collision_with_self() or not self.is_inside_window():
self.running = False
def run_game_logic(self):
"""
The entry point of the game.
Clears the screen, runs the game logic, and make sure that the
screen is presented at the end.
"""
for event in pygame.event.get():
if event.type == pygame.QUIT:
self.running = False
elif event.type == pygame.KEYDOWN:
self.handle_keydown(event)
time_since_update = pygame.time.get_ticks() - self.last_update_time
if time_since_update > 150:
self.last_update_time = pygame.time.get_ticks()
self.update_move()
self.fruit_pickup()
self.draw()
def game_loop(self):
"""
The main loop of the game.
Will continue to play until running is set to false.
"""
self.running = True
while self.running:
self.window.clear()
self.run_game_logic()
pygame.display.flip()