Game-State

A state machine for organizing different in-game screens in python.

Table of Contents

• Requirements
• Installation
• Getting Started
• Links

Requirements

This library supports python versions 3.8 - 3.14.

Installation

Create and activate a virtual environment in your workspace (optional) and run the following command-

pip install game_state

Note: This package does not have any dependancy on pygame, hence you will need to install them separately on your own. This gives you the freedom to work with pygame, pygame-ce or any of it's forks.

Getting Started

This is an example of creating two screens. One displaying green colour and the other blue with a player.

import pygame
from game_state import State, StateManager
from game_state.utils import MISSING


GREEN = (0, 255, 0)
BLUE = (0, 0, 255)
speed = 200
pygame.init()
pygame.display.init()
pygame.display.set_caption("Game State Example")


class MyBaseState(State["MyBaseState"]):
    screen: pygame.Surface = MISSING


class MainMenuState(MyBaseState, state_name="MainMenu"):
    def process_event(self, event: pygame.event.Event) -> None:
        if event.type == pygame.QUIT:
            self.manager.is_running = False

        if event.type == pygame.KEYDOWN and event.key == pygame.K_w:
            self.manager.change_state("Game")

    def process_update(self, *args: float) -> None:
        self.screen.fill(GREEN)
        pygame.display.update()


class GameState(MyBaseState, state_name="Game"):
    def __init__(self) -> None:
        self.player_x: float = 250.0

    def process_event(self, event: pygame.event.Event) -> None:
        if event.type == pygame.QUIT:
            self.manager.is_running = False

        if event.type == pygame.KEYDOWN and event.key == pygame.K_w:
            self.manager.change_state("MainMenu")

    def process_update(self, *args: float) -> None:
        dt = args[0]

        self.screen.fill(BLUE)

        # Player movement-
        pressed = pygame.key.get_pressed()
        if pressed[pygame.K_a]:
            self.player_x -= speed * dt

        if pressed[pygame.K_d]:
            self.player_x += speed * dt

        pygame.draw.rect(
            self.screen,
            "red",
            (
                self.player_x,
                100,
                50,
                50,
            ),
        )
        pygame.display.update()


def main() -> None:
    screen = pygame.display.set_mode((500, 600))

    state_manager = StateManager[MyBaseState](
        bound_state_type=MyBaseState, screen=screen
    )
    state_manager.load_states(MainMenuState, GameState)
    state_manager.change_state("MainMenu")

    clock = pygame.time.Clock()

    while state_manager.is_running:
        dt = clock.tick(60) / 1000

        for event in pygame.event.get():
            state_manager.current_state.process_event(event)

        state_manager.current_state.process_update(dt)


if __name__ == "__main__":
    main()

You can have a look at the game state guide for a more detailed explaination.

Links

• Guide & API Reference: https://game-state.readthedocs.io/en/stable/
• PyPI Page: https://pypi.org/project/game-state/
• Github Page: https://github.com/Jiggly-Balls/game-state/