Connecting Multiple Clients

Connecting Multiple Clients

This python online game tutorial covers connecting multiple clients to a server. I go over how to send valuable information from the client to the server and vice versa. At the end of this tutorial you will have a working game where moving a rectangle on one client will move it on the other.

client.py

import pygame
from network import Network

width = 500
height = 500
win = pygame.display.set_mode((width, height))
pygame.display.set_caption("Client")

clientNumber = 0


class Player():
    def __init__(self, x, y, width, height, color):
        self.x = x
        self.y = y
        self.width = width
        self.height = height
        self.color = color
        self.rect = (x,y,width,height)
        self.vel = 3

    def draw(self, win):
        pygame.draw.rect(win, self.color, self.rect)

    def move(self):
        keys = pygame.key.get_pressed()

        if keys[pygame.K_LEFT]:
            self.x -= self.vel

        if keys[pygame.K_RIGHT]:
            self.x += self.vel

        if keys[pygame.K_UP]:
            self.y -= self.vel

        if keys[pygame.K_DOWN]:
            self.y += self.vel

        self.update()

    def update(self):
        self.rect = (self.x, self.y, self.width, self.height)


def read_pos(str):
    str = str.split(",")
    return int(str[0]), int(str[1])


def make_pos(tup):
    return str(tup[0]) + "," + str(tup[1])


def redrawWindow(win,player, player2):
    win.fill((255,255,255))
    player.draw(win)
    player2.draw(win)
    pygame.display.update()


def main():
    run = True
    n = Network()
    startPos = read_pos(n.getPos())
    p = Player(startPos[0],startPos[1],100,100,(0,255,0))
    p2 = Player(0,0,100,100,(255,0,0))
    clock = pygame.time.Clock()

    while run:
        clock.tick(60)
        p2Pos = read_pos(n.send(make_pos((p.x, p.y))))
        p2.x = p2Pos[0]
        p2.y = p2Pos[1]
        p2.update()

        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                run = False
                pygame.quit()

        p.move()
        redrawWindow(win, p, p2)

main()

network.py

import socket


class Network:
    def __init__(self):
        self.client = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        self.server = "YOUR LOCAL IPV4"
        self.port = 5555
        self.addr = (self.server, self.port)
        self.pos = self.connect()

    def getPos(self):
        return self.pos

    def connect(self):
        try:
            self.client.connect(self.addr)
            return self.client.recv(2048).decode()
        except:
            pass

    def send(self, data):
        try:
            self.client.send(str.encode(data))
            return self.client.recv(2048).decode()
        except socket.error as e:
            print(e)

server.py

import socket
from _thread import *
import sys

server = "YOUR LOCAL IPV4"
port = 5555

s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)

try:
    s.bind((server, port))
except socket.error as e:
    str(e)

s.listen(2)
print("Waiting for a connection, Server Started")

def read_pos(str):
    str = str.split(",")
    return int(str[0]), int(str[1])


def make_pos(tup):
    return str(tup[0]) + "," + str(tup[1])

pos = [(0,0),(100,100)]

def threaded_client(conn, player):
    conn.send(str.encode(make_pos(pos[player])))
    reply = ""
    while True:
        try:
            data = read_pos(conn.recv(2048).decode())
            pos[player] = data

            if not data:
                print("Disconnected")
                break
            else:
                if player == 1:
                    reply = pos[0]
                else:
                    reply = pos[1]

                print("Received: ", data)
                print("Sending : ", reply)

            conn.sendall(str.encode(make_pos(reply)))
        except:
            break

    print("Lost connection")
    conn.close()

currentPlayer = 0
while True:
    conn, addr = s.accept()
    print("Connected to:", addr)

    start_new_thread(threaded_client, (conn, currentPlayer))
    currentPlayer += 1