metagrid 0.4.0

Metagrid is a simple game engine for 2D Grid Games

Metagrid

Version française

Description

Metagrid is a Python library for creating simple 2D grid games. Each cell in the grid can display:

• a solid color
• an image
• a character

Installation

pip install metagrid

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Tutorial

Program structure

Every metagrid program follows the same three-step pattern:

1. Declare the game state variables (globals).
2. Write the callback functions (on_init, on_update, on_draw, on_click, on_key).
3. In the if __name__ == "__main__" block: create the engine, register the callbacks, then start the loop with game.start().

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1. Create the engine

import metagrid

game = metagrid.create(rows, cols, cell_size, margin)

Parameter	Role
rows	Number of rows in the grid
cols	Number of columns in the grid
cell_size	Size in pixels of each cell
margin	Thickness in pixels of the border between cells

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2. Callbacks

Callbacks are plain functions passed to the engine. Metagrid calls them automatically at the right time.

on_init — initialization

Called once at startup, before the first frame. Reset all game state here.

def init():
    print("Game initialized")

game.on_init(init)

on_update — game logic

Called every frame, before drawing. Advance the game state here.

game.frame_no holds the current frame number (starts at 0, increments by 1 per frame). Useful for triggering periodic actions without an external timer.

def update():
    if game.frame_no % 120 == 0:   # every 2 seconds at 60 fps
        print("tick")

game.on_update(update)

on_draw — drawing

Called every frame, after update. Translate the game state into colors / images / characters here.

def draw():
    for i in range(5):
        for j in range(5):
            val = grid[i][j]
            if val == 1:
                game.set_cell_color(i, j, "#135683")
            elif val == 2:
                game.set_cell_char(i, j, "X", "#000000")

game.on_draw(draw)

on_click — mouse click

Called when the user clicks on a cell.

def click(i: int, j: int, button: str):
    # i, j   : coordinates of the clicked cell
    # button : "left", "right" or "middle"
    print(f"Cell ({i}, {j}) clicked with {button}")

game.on_click(click)

on_key — keyboard

Called when the user presses a key.

def key(k: str):
    # k : character ('a', 'z', ' ', …) or special key name
    print(f"Key {k} pressed")

game.on_key(key)

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3. Drawing in cells

Three functions change the appearance of cell (i, j) (row i, column j, both starting at 0 from the top-left):

Solid color

game.set_cell_color(i, j, "#RRGGBB")

Character

game.set_cell_char(i, j, "A", "#RRGGBB")

One character per cell, centered on top of the background.

Image

Load an image once (before game.start()), then display it:

game.load_image("image_name", "path/to/image.png")
# …
game.set_cell_image(i, j, "image_name")

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4. Start the loop

game.start()   # blocks until the window is closed

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Full example

import metagrid
from metagrid import AbstractEngine

grid: list[list[int]] = [
    [0, 1, 0, 0, 0],
    [0, 0, 2, 1, 0],
    [2, 0, 0, 0, 0],
    [0, 1, 0, 0, 0],
    [0, 0, 0, 0, 1],
]

game: AbstractEngine


def init():
    print("Game initialized")


def click(i: int, j: int, button: str):
    print(f"Cell ({i}, {j}) clicked with {button}")


def key(k: str):
    print(f"Key {k} pressed")


def update():
    if game.frame_no % 120 == 0:
        print("Update every 2 seconds")


def draw():
    for i in range(5):
        for j in range(5):
            val = grid[i][j]
            if val == 1:
                game.set_cell_color(i, j, "#135683")
            elif val == 2:
                game.set_cell_char(i, j, "X", "#000000")


if __name__ == "__main__":
    game = metagrid.create(5, 5, 50, 1)

    game.on_init(init)
    game.on_click(click)
    game.on_key(key)
    game.on_update(update)
    game.on_draw(draw)

    game.start()

The full source is available in examples/full_example.py.

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Included examples

File	Game
examples/snake.py	Snake
examples/jeudelavie.py	Game of Life
examples/jeu2048.py	2048
examples/puissance4.py	Connect Four
examples/memory.py	Memory
examples/lights_out.py	Lights Out
examples/sokoban.py	Sokoban
examples/taquin.py	Sliding Puzzle
examples/wordle.py	Wordle