Question

I’ve made a pathfinding visualizer using python and pygame. As of now, it can simulate only one algorithm at a time. I want to spawn multiple windows, each simulating different algorithm, side by side so that algorithms can be analyzed against each other. I have a function client.run() that draws the GUI. I’m trying to spawn multiple instances like this:

p=threading.Thread(target = client.run)
q=threading.Thread(target = client.run)
p.start()
q.start()    

But by doing so my program hangs! Is there any way to rectify this problem, or any alternative way of running multiple instances/windows?

Answer 1

Pygame is built in a way to have a single window by process, you can’t avoid that. The pygame.display module sets you a “display” and that is what you get.

You are in good look, as you have designed you software to work with threads, and have each thread control a display.. Just change the “threading” Python module for the multiprocessing, and use multiprocessing.Process instead of threading.Threads — as long as you initialize pygame and its display from within each subprocess you should be ok.

I just teste here and teh example bellow works fine:

# -*- coding: utf-8 -*-
import pygame
import multiprocessing
from time import sleep



def init():
    pygame.init()
    screen = pygame.display.set_mode((320,240))
    return screen

def main():
    screen = init()
    while True:
        pygame.event.pump()
        event =  pygame.event.poll()
        if event.type != pygame.NOEVENT:
            print event


class Multigame(multiprocessing.Process):
    def run(self):
        return main()

for i in range(3):
    Multigame().start()

while True:
    sleep(1)