PySDL2 Life Demo

life.py

import sys
import sdl2
import sdl2.ext

import numpy as np

class Life(object):

    def __init__(self, height, width):
        self.width = width
        self.height = height
        self.buf = np.random.randint(0, 255, (self.height+2, self.width), dtype=np.uint8) == 0

    def __call__(self):
        self.buf = np.roll(self.buf, -1, axis=0)
        self.buf[-1] = np.random.randint(0, 3, (1, self.width), dtype=np.uint8) == 0
        hneighbours = np.roll(self.buf, 1, axis=0)*1 + self.buf*1 + np.roll(self.buf, -1, axis=0)*1
        neighbours = np.roll(hneighbours, 1, axis=1)*1 + hneighbours*1 + np.roll(hneighbours, -1, axis=1)*1 - self.buf
        self.buf = self.buf & (neighbours > 1) & (neighbours < 4)
        self.buf = self.buf | (neighbours == 3)
        return self.buf[2:][:,:,np.newaxis] * np.array([[[255, 255, 255, 255]]])

def run():
    sdl2.ext.init()
    window = sdl2.ext.Window("Life", size=(800, 600))
    window.show()
    life = Life(*window.size)
    surfarray = sdl2.ext.pixels3d(window.get_surface())
    running = True
    while running:
        events = sdl2.ext.get_events()
        for event in events:
            if event.type == sdl2.SDL_QUIT:
                running = False
                break
        surfarray[:] = life()
        window.refresh()
    return 0

if __name__ == "__main__":
    sys.exit(run())