A Good Way To Switch To A Menu Using Pygame

I am using PyGame to create a game, and can't figure a clean way to switch between scenes and menus. I don't know if I need to create a scene class for each thing with its own upda

Solution 1:

There are different strategies and it depends on what functionality you want. One simple way is to have each scene in a function that returns what the next scene should be. Then create a simple if-statement that switches between them in the main game loop.

import pygame
pygame.init()

SCENE_MENU = 0
SCENE_GAME = 1
SCENE_SHOP = 2defmenu(screen):
    # Initialize game variables as the player, enemies and such.
    fps_cap = 30
    options = ['continue', 'save', 'quit']
    clock = pygame.time.Clock()

    # Game loop.whileTrue:

        # Time management.
        clock.tick(fps_cap)

        # Handle events.for event in pygame.event.get():
            if event.type == pygame.QUIT:
                quit()
            elif event.type == pygame.KEYDOWN:
                if event.key == pygame.K_a:    # Go to game if you press A.return SCENE_GAME
                elif event.key == pygame.K_b:  # Go to shop if you press B.return SCENE_SHOP

        # Update the menu (like buttons, settings, ...).print('Updating buttons:', *options)

        # Draw the shop.
        screen.fill((0, 0, 255))  # A green menu.
        pygame.display.update()


defgame(screen):
    # Initialize game variables as the player, enemies and such.
    fps_cap = 60
    player  = 'Ted'
    clock   = pygame.time.Clock()

    # Game loop.whileTrue:

        # Time management.
        clock.tick(fps_cap)

        # Handle events.for event in pygame.event.get():
            if event.type == pygame.QUIT:
                quit()
            elif event.type == pygame.KEYDOWN:
                if event.key == pygame.K_a:    # Go to menu if you press A.return SCENE_MENU
                elif event.key == pygame.K_b:  # Go to shop if you press B.return SCENE_SHOP

        # Update the game.print(f'Player {player} is playing!')

        # Draw your game.
        screen.fill((0, 255, 0))  # A blue game.
        pygame.display.update()


defshop(screen):
    # Initialize game variables as the player, enemies and such.
    fps_cap = 30
    items = ['sword', 'armor', 'potion']
    clock = pygame.time.Clock()

    # Game loop.whileTrue:

        # Time management.
        clock.tick(fps_cap)

        # Handle events.for event in pygame.event.get():
            if event.type == pygame.QUIT:
                quit()
            elif event.type == pygame.KEYDOWN:
                if event.key == pygame.K_a:    # Go to game if you press A.return SCENE_GAME
                elif event.key == pygame.K_b:  # Go to shop if you press B.return SCENE_SHOP

        # Update the shop (like buttons, money transfers, ...).print('Looking at items:', *items)

        # Draw the shop.
        screen.fill((255, 0, 0))  # A red shop.
        pygame.display.update()


defmain():
    screen = pygame.display.set_mode((100, 100))
    scene = SCENE_MENU
    whileTrue:
        if scene == SCENE_MENU:
            scene = menu(screen)
        elif scene == SCENE_SHOP:
            scene = shop(screen)
        elif scene == SCENE_GAME:
            scene = game(screen)

main()

This is just a simple example, but should show the principle.