Multiple Game Loops in Pygame-ce
When building a game in Pygame Community Edition (pygame-ce), the typical approach is to have a single game loop handling everything—events, updates, and rendering. For more complex games with menus, cutscenes, or different gameplay modes, it’s often useful to implement multiple game loops instead of stuffing everything into one big loop. In this article, we’ll explore how to structure a Pygame-ce project with multiple game loops for better organization and flexibility. Most basic Pygame tutorials show a single game loop, which looks something like this: import pygame pygame.init() screen = pygame.display.set_mode((800, 600)) clock = pygame.time.Clock() running = True while running: for event in pygame.event.get(): if event.type == pygame.QUIT: running = False screen.fill((0, 0, 0)) pygame.display.flip() clock.tick(60) pygame.quit() Here, we are creating the window the game opens in, the game screen, setting the frame rate, and allowing users to quit the game. This is nice and simple now, but becomes rather complex and hard-to-read once you start incorporating things like a menu or different game modes. Trying to cram these elements into one game loop would require many conditionals that quickly create an overly complex and hard-to-read code. Instead, we can create multiple game loops to separate different aspects of the game. The different loops will be handled by a game state manager to switch in and out of different loops. To start, let's use a function based approach to store the different game states and switch between them dynamically. import pygame pygame.init() screen = pygame.display.set_mode((800, 600)) clock = pygame.time.Clock() # Game state manager def game_state_manager(state): while state is not None: state = state() # Call the current state function and get the next state # Placeholder states def main_menu(): print("Main Menu") running = True while running: for event in pygame.event.get(): if event.type == pygame.QUIT: return None # Exit the game if event.type == pygame.KEYDOWN and event.key == pygame.K_RETURN: return game_loop # Switch to game loop screen.fill((30, 30, 30)) pygame.display.flip() clock.tick(60) def game_loop(): print("Game Loop") running = True while running: for event in pygame.event.get(): if event.type == pygame.QUIT: return None # Exit the game if event.type == pygame.KEYDOWN and event.key == pygame.K_p: return pause_menu # Switch to pause menu screen.fill((0, 0, 255)) pygame.display.flip() clock.tick(60) def pause_menu(): print("Pause Menu") running = True while running: for event in pygame.event.get(): if event.type == pygame.QUIT: return None # Exit the game if event.type == pygame.KEYDOWN: if event.key == pygame.K_RETURN: return game_loop # Resume game if event.key == pygame.K_ESCAPE: return main_menu # Go back to main menu screen.fill((100, 100, 100)) pygame.display.flip() clock.tick(60) # Start the game at the main menu game_state_manager(main_menu) pygame.quit() How this works: The function game_state_manager() keeps calling different state functions until None is returned. Once None is returned, it will exit the game. Each state is defined as a function with its own game loop. When a state needs to switch, it returns another function which becomes the new active state. It might sound complicated at first, but once you get the hang of switching states to switch game loops you'll realize the individual game loops will be easier to manage since they are now more modular. This approach also allows for more flexibility in adding and removing new states without breaking the existing logic. Finally, separating game loops improves readabilty, leading to a cleaner, more organized code. If you're building a more complex game, consider using this multiple game loop approach to keep your code clean and maintained!
When building a game in Pygame Community Edition (pygame-ce), the typical approach is to have a single game loop handling everything—events, updates, and rendering. For more complex games with menus, cutscenes, or different gameplay modes, it’s often useful to implement multiple game loops instead of stuffing everything into one big loop.
In this article, we’ll explore how to structure a Pygame-ce project with multiple game loops for better organization and flexibility.
Most basic Pygame tutorials show a single game loop, which looks something like this:
import pygame
pygame.init()
screen = pygame.display.set_mode((800, 600))
clock = pygame.time.Clock()
running = True
while running:
for event in pygame.event.get():
if event.type == pygame.QUIT:
running = False
screen.fill((0, 0, 0))
pygame.display.flip()
clock.tick(60)
pygame.quit()
Here, we are creating the window the game opens in, the game screen, setting the frame rate, and allowing users to quit the game. This is nice and simple now, but becomes rather complex and hard-to-read once you start incorporating things like a menu or different game modes. Trying to cram these elements into one game loop would require many conditionals that quickly create an overly complex and hard-to-read code.
Instead, we can create multiple game loops to separate different aspects of the game. The different loops will be handled by a game state manager to switch in and out of different loops.
To start, let's use a function based approach to store the different game states and switch between them dynamically.
import pygame
pygame.init()
screen = pygame.display.set_mode((800, 600))
clock = pygame.time.Clock()
# Game state manager
def game_state_manager(state):
while state is not None:
state = state() # Call the current state function and get the next state
# Placeholder states
def main_menu():
print("Main Menu")
running = True
while running:
for event in pygame.event.get():
if event.type == pygame.QUIT:
return None # Exit the game
if event.type == pygame.KEYDOWN and event.key == pygame.K_RETURN:
return game_loop # Switch to game loop
screen.fill((30, 30, 30))
pygame.display.flip()
clock.tick(60)
def game_loop():
print("Game Loop")
running = True
while running:
for event in pygame.event.get():
if event.type == pygame.QUIT:
return None # Exit the game
if event.type == pygame.KEYDOWN and event.key == pygame.K_p:
return pause_menu # Switch to pause menu
screen.fill((0, 0, 255))
pygame.display.flip()
clock.tick(60)
def pause_menu():
print("Pause Menu")
running = True
while running:
for event in pygame.event.get():
if event.type == pygame.QUIT:
return None # Exit the game
if event.type == pygame.KEYDOWN:
if event.key == pygame.K_RETURN:
return game_loop # Resume game
if event.key == pygame.K_ESCAPE:
return main_menu # Go back to main menu
screen.fill((100, 100, 100))
pygame.display.flip()
clock.tick(60)
# Start the game at the main menu
game_state_manager(main_menu)
pygame.quit()
How this works:
The function game_state_manager() keeps calling different state functions until None is returned. Once None is returned, it will exit the game.
Each state is defined as a function with its own game loop.
When a state needs to switch, it returns another function which becomes the new active state.
It might sound complicated at first, but once you get the hang of switching states to switch game loops you'll realize the individual game loops will be easier to manage since they are now more modular. This approach also allows for more flexibility in adding and removing new states without breaking the existing logic. Finally, separating game loops improves readabilty, leading to a cleaner, more organized code.
If you're building a more complex game, consider using this multiple game loop approach to keep your code clean and maintained!
