Snake Game

Let 's use chatGPT now to build this game.

1. Initialization and Constants

import pygame
import sys
import random

pygame.init()

WIDTH, HEIGHT = 600, 400
GRID_SIZE = 20
FPS = 10

SILVER = (192, 192, 192)
WHITE = (255, 255, 255)
RED = (255, 0, 0)
BLUE = (0, 0, 255)
  • pygame.init(): Initializes the Pygame library.

  • WIDTH and HEIGHT: Define the dimensions of the game window.

  • GRID_SIZE: Specifies the size of each grid cell.

  • FPS: Sets the frames per second for the game loop.

  • SILVER, WHITE, RED, and BLUE: Define color constants using RGB values.

2. Snake Class

class Snake:
    def __init__(self):
        self.length = 1
        self.positions = [((WIDTH // 2), (HEIGHT // 2))]
        self.direction = random.choice([UP, DOWN, LEFT, RIGHT])
        self.color = RED
  • __init__: Initializes the Snake object with default values.

  • self.length: Tracks the length of the snake.

  • self.positions: Stores the positions of the snake's body segments.

  • self.direction: Represents the current direction of the snake.

  • self.color: Sets the colour of the snake.

3. Fruit Class

class Fruit:
    def __init__(self):
        self.position = (0, 0)
        self.color = BLUE
        self.randomize_position()
  • __init__: Initializes the Fruit object with default values.

  • self.position: Stores the position of the fruit on the grid.

  • self.color: Sets the colour of the fruit.

4. Directions and Grid Drawing

UP = (0, -1)
DOWN = (0, 1)
LEFT = (-1, 0)
RIGHT = (1, 0)

def draw_grid(surface):
    for y in range(0, HEIGHT, GRID_SIZE):
        for x in range(0, WIDTH, GRID_SIZE):
            rect = pygame.Rect(x, y, GRID_SIZE, GRID_SIZE)
            pygame.draw.rect(surface, SILVER, rect)
  • UP, DOWN, LEFT, and RIGHT: Represent directional movements.

  • draw_grid: Draws the grid on the game surface using rectangles.

5. Main Game Loop

def main():
    # ... (snip)

    while True:
        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                pygame.quit()
                sys.exit()
            elif event.type == pygame.KEYDOWN:
                if event.key == pygame.K_UP:
                    snake.direction = UP
                elif event.key == pygame.K_DOWN:
                    snake.direction = DOWN
                elif event.key == pygame.K_LEFT:
                    snake.direction = LEFT
                elif event.key == pygame.K_RIGHT:
                    snake.direction = RIGHT

        snake.update()
        if snake.get_head_position() == fruit.position:
            snake.length += 1
            fruit.randomize_position()
            score += 1

        # ... (snip)

if __name__ == "__main__":
    main()
  • main: The main game loop where user input is handled, and the game state is updated.

  • The loop processes events, such as quitting the game or changing the snake's direction with arrow keys.

  • snake.update: Updates the snake's position based on its current direction.

  • Check if the snake has eaten the fruit, update the score, and randomize the fruit's position.

  • Calls the rendering functions to display the game elements.

  • The game continues to run in this loop until the user closes the window.

This code provides a basic implementation of the Snake game using the Pygame library.

The Complete Code

import pygame
import sys
import random

# Initialize Pygame
pygame.init()

# Constants
WIDTH, HEIGHT = 600, 400
GRID_SIZE = 20
FPS = 10

# Colors
SILVER = (192, 192, 192)
WHITE = (255, 255, 255)
RED = (255, 0, 0)

# Snake class
class Snake:
    def __init__(self):
        self.length = 1
        self.positions = [((WIDTH // 2), (HEIGHT // 2))]
        self.direction = random.choice([UP, DOWN, LEFT, RIGHT])
        self.color = RED

    def get_head_position(self):
        return self.positions[0]

    def update(self):
        cur = self.get_head_position()
        x, y = self.direction
        new = (((cur[0] + (x * GRID_SIZE)) % WIDTH), (cur[1] + (y * GRID_SIZE)) % HEIGHT)
        if len(self.positions) > 2 and new in self.positions[2:]:
            self.reset()
        else:
            self.positions.insert(0, new)
            if len(self.positions) > self.length:
                self.positions.pop()

    def reset(self):
        self.length = 1
        self.positions = [((WIDTH // 2), (HEIGHT // 2))]
        self.direction = random.choice([UP, DOWN, LEFT, RIGHT])

    def render(self, surface):
        for p in self.positions:
            pygame.draw.circle(surface, self.color, (p[0] + GRID_SIZE // 2, p[1] + GRID_SIZE // 2), GRID_SIZE // 2)

# Fruit class
class Fruit:
    def __init__(self):
        self.position = (0, 0)
        self.color = WHITE
        self.randomize_position()

    def randomize_position(self):
        self.position = (random.randint(0, (WIDTH // GRID_SIZE) - 1) * GRID_SIZE,
                         random.randint(0, (HEIGHT // GRID_SIZE) - 1) * GRID_SIZE)

    def render(self, surface):
        pygame.draw.circle(surface, self.color, (self.position[0] + GRID_SIZE // 2, self.position[1] + GRID_SIZE // 2), GRID_SIZE // 2)

# Directions
UP = (0, -1)
DOWN = (0, 1)
LEFT = (-1, 0)
RIGHT = (1, 0)

def draw_grid(surface):
    for y in range(0, HEIGHT, GRID_SIZE):
        for x in range(0, WIDTH, GRID_SIZE):
            rect = pygame.Rect(x, y, GRID_SIZE, GRID_SIZE)
            pygame.draw.rect(surface, SILVER, rect)

def main():
    clock = pygame.time.Clock()
    screen = pygame.display.set_mode((WIDTH, HEIGHT), 0, 32)
    surface = pygame.Surface(screen.get_size())
    surface = surface.convert()

    snake = Snake()
    fruit = Fruit()

    # Fonts
    font = pygame.font.SysFont("Arial", 24)
    score = 0

    while True:
        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                pygame.quit()
                sys.exit()
            elif event.type == pygame.KEYDOWN:
                if event.key == pygame.K_UP:
                    snake.direction = UP
                elif event.key == pygame.K_DOWN:
                    snake.direction = DOWN
                elif event.key == pygame.K_LEFT:
                    snake.direction = LEFT
                elif event.key == pygame.K_RIGHT:
                    snake.direction = RIGHT

        snake.update()
        if snake.get_head_position() == fruit.position:
            snake.length += 1
            fruit.randomize_position()
            score += 1

        surface.fill(SILVER)
        draw_grid(surface)
        snake.render(surface)
        fruit.render(surface)

        # Display score
        score_text = font.render("Score: {}".format(score), True, WHITE)
        surface.blit(score_text, (10, 10))

        screen.blit(surface, (0, 0))
        pygame.display.update()
        clock.tick(FPS)

if __name__ == "__main__":
    main()