先得五分

Coddy 用 Pygame 制作游戏课程的第 37 课，共 41 课。

第一个得到 5 分的玩家获胜。将获胜者的名字存入一个变量，该变量的初始值为 None，这是 Python 表示“暂时什么都没有”的值：

winner = None

if left_score == 5:
    winner = "Left player wins!"
elif right_score == 5:
    winner = "Right player wins!"

用 winner is None 或 winner is not None 来测试。有人获胜后，球会继续等待：只有在 winner is None 时，按空格键才会发球。

将获胜者显示在 (300, 120) 的居中位置，替代发球提示。

挑战

中等

先得 5 分的一方获胜。

在循环之前，设置 winner = None。计分后，当 left_score == 5 时，将它设为 "Left player wins!"；当 right_score == 5 时，将它设为 "Right player wins!"。
只有在 winner is None 时，按空格键才会发球。
在 (300, 120) 处显示获胜者，而不是显示 Press Space to serve。

点击 “开始”：达到 5 分时会显示获胜者。然后点击 “检查”。

亲手试试

import pygame

pygame.init()
screen = pygame.display.set_mode((600, 400))
pygame.display.set_caption("Pong")
clock = pygame.time.Clock()
font = pygame.font.Font(None, 36)

ball = pygame.Rect(293, 193, 14, 14)
vx, vy = 5, 4
left = pygame.Rect(20, 160, 12, 80)
right = pygame.Rect(568, 160, 12, 80)
left_score = 0
right_score = 0
waiting = False

running = True
while running:
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            running = False
        elif event.type == pygame.KEYDOWN and event.key == pygame.K_SPACE:
            waiting = False

    keys = pygame.key.get_pressed()
    if keys[pygame.K_w]:
        left.y -= 6
    if keys[pygame.K_s]:
        left.y += 6
    if keys[pygame.K_UP]:
        right.y -= 6
    if keys[pygame.K_DOWN]:
        right.y += 6
    left.clamp_ip(screen.get_rect())
    right.clamp_ip(screen.get_rect())

    if not waiting:
        ball.x += vx
        ball.y += vy
        if ball.top <= 0 or ball.bottom >= 400:
            vy = -vy
        if ball.colliderect(left):
            vx = abs(vx)
            vy = (ball.centery - left.centery) // 6
        if ball.colliderect(right):
            vx = -abs(vx)
            vy = (ball.centery - right.centery) // 6
        if ball.left > 600:
            left_score += 1
            ball.center = (300, 200)
            vx = -vx
            waiting = True
        if ball.right < 0:
            right_score += 1
            ball.center = (300, 200)
            vx = -vx
            waiting = True

    screen.fill((30, 30, 46))
    pygame.draw.rect(screen, (80, 160, 255), left)
    pygame.draw.rect(screen, (235, 80, 80), right)
    pygame.draw.rect(screen, (255, 196, 0), ball)
    score = font.render(f"{left_score} : {right_score}", True, (240, 240, 240))
    screen.blit(score, score.get_rect(center=(300, 30)))
    if waiting:
        message = font.render("Press Space to serve", True, (240, 240, 240))
        screen.blit(message, message.get_rect(center=(300, 360)))
    pygame.display.flip()
    clock.tick(60)

pygame.quit()