pong.py

# This codebase was originally posted alongside this YouTube video:
# https://www.youtube.com/watch?v=5NkTzvMchMw

# hi, folks!
# another comment

import pygame, sys, random

class PongBall(pygame.Rect):
    def __init__(self, left, top, height, width):
        super().__init__(left, top, height, width)

    def set_center(self, x, y):
        self.center = (x, y)




def reset_ball():
    global ball_speed_x, ball_speed_y
    ball.x = screen_width/2 - 10
    ball.y = random.randint(10,100)
    ball_speed_x *= random.choice([-1,1])
    ball_speed_y *= random.choice([-1,1])

def point_won(winner):
    global cpu_points, player_points

    if winner == "cpu":
        cpu_points += 1
    if winner == "player":
        player_points += 1

    reset_ball()

def animate_ball():
    global ball_speed_x, ball_speed_y
    ball.x += ball_speed_x
    ball.y += ball_speed_y

    if ball.bottom >= screen_height or ball.top <= 0:
        ball_speed_y *= -1

    if ball.right >= screen_width:
        point_won("cpu")

    if ball.left <= 0:
        point_won("player")
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    
    if ball.colliderect(player) or ball.colliderect(cpu):
        ball_speed_x *= -1

def animate_player():
    player.y += player_speed

    if player.top <= 0:
        player.top = 0

    if player.bottom >= screen_height:
        player.bottom = screen_height

def animate_cpu():
    global cpu_speed
    cpu.y += cpu_speed / 1.2

    if ball.centery <= cpu.centery:
        cpu_speed = -6
    if ball.centery >= cpu.centery:
        cpu_speed = 6

    if cpu.top <= 0:
        cpu.top = 0
    if cpu.bottom >= screen_height:
        cpu.bottom = screen_height

pygame.init()

screen_width = 1280
screen_height = 800

screen = pygame.display.set_mode((screen_width, screen_height))
pygame.display.set_caption("My Pong Game!")

clock = pygame.time.Clock()

ball = PongBall(0, 0, 30, 30)
ball.set_center(screen_width/2, screen_height/2)

cpu = pygame.Rect(0,0,20,100)
cpu.centery = screen_height/2

player = pygame.Rect(0,0,20,100)
player.midright = (screen_width, screen_height/2)

ball_speed_x = 6
ball_speed_y = 6
player_speed = 0
cpu_speed = 6

cpu_points, player_points = 0, 0

score_font = pygame.font.Font(None, 100)

while True:
    #Check for events
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            pygame.quit()
            sys.exit()
        if event.type == pygame.KEYDOWN:
            if event.key == pygame.K_UP:
                player_speed = -6
            if event.key == pygame.K_DOWN:
                player_speed = 6
        if event.type == pygame.KEYUP:
            if event.key == pygame.K_UP:
                player_speed = 0
            if event.key == pygame.K_DOWN:
                player_speed = 0

    #Change the positions of the game objects
    animate_ball()
    animate_player()
    animate_cpu()
        
    #Clear the screen
    screen.fill('black')

    #Draw the score
    cpu_score_surface = score_font.render(str(cpu_points), True, "white")
    player_score_surface = score_font.render(str(player_points), True, "white")
    screen.blit(cpu_score_surface,(screen_width/4,20))
    screen.blit(player_score_surface,(3*screen_width/4,20))

    #Draw the game objects
    pygame.draw.aaline(screen,'white',(screen_width/2, 0), (screen_width/2, screen_height))
    pygame.draw.ellipse(screen,'white',ball)
    pygame.draw.rect(screen,'white',cpu)
    pygame.draw.rect(screen,'white',player)

    #Update the display
    pygame.display.update()
    clock.tick(60)