Python Turtle Pong游戏开发：深入理解碰撞检测与游戏循环优化

if the_ball.distance(r_paddle) and the_ball.xcor() > 320 or the_ball.distance(l_paddle) < 50 and the_ball.xcor() < -320:
    the_ball.x_bounce()

if the_ball.distance(r_paddle) < 50 and the_ball.xcor() > 320 or the_ball.distance(l_paddle) < 50 and the_ball.xcor() < -320:
    the_ball.x_bounce()

while game_is_on:
    time.sleep(0.1)
    screen.update()
    the_ball.move()
    # ... collision logic ...

from turtle import Screen, Turtle
import time # 尽管最终会用ontimer，但为了展示差异，这里保留

# --- Scoreboard Class ---
class Scoreboard(Turtle):
    def __init__(self):
        super().__init__()
        self.hideturtle()
        self.color('white')
        self.penup()
        self.l_score = 0
        self.r_score = 0
        self.update_score()

    def update_score(self):
        self.clear()
        self.goto(-100, 200)
        self.write(self.l_score, align='center', font=('Courier', 80, 'normal'))
        self.goto(100, 200)
        self.write(self.r_score, align='center', font=('Courier', 80, 'normal'))
        # 每次分数更新后立即刷新屏幕，确保显示最新分数
        screen.update()

    def left_point(self):
        self.l_score += 1
        self.update_score()

    def right_point(self):
        self.r_score += 1
        self.update_score()

# --- Ball Class ---
class Ball(Turtle):
    def __init__(self):
        super().__init__()
        self.shape('circle')
        self.color('white')
        self.penup() # 确保不绘制移动轨迹
        self.x_move = 10
        self.y_move = 10

    def move(self):
        new_x = self.xcor() + self.x_move
        new_y = self.ycor() + self.y_move
        self.goto(new_x, new_y)
        # 每次球移动后立即刷新屏幕
        screen.update()

    def y_bounce(self):
        self.y_move *= -1

    def x_bounce(self):
        self.x_move *= -1

    def reset_position(self):
        self.goto(0, 0)
        self.x_bounce() # 重置后球反向移动
        # 重置位置后立即刷新屏幕
        screen.update()

# --- Paddle Class ---
class Paddle(Turtle):
    def __init__(self):
        super().__init__()
        self.shape('square')
        self.color('white')
        # 调整shapesize，使其在setheading(90)后仍保持垂直长条状
        # 原始shapesize(5, 1)是竖直的，但若不改变setheading，则需要shapesize(1, 5)
        # 这里为了配合setheading(90)使其“向上”是沿着其长边，所以 shapesize(1, 5)
        self.shapesize(stretch_wid=1, stretch_len=5) # 宽度1，长度5
        self.setheading(90) # 设置朝向为向上，这样go_up/go_down可以利用forward/backward
        self.penup()

    def go_up(self):
        # 使用forward代替直接修改ycor，更符合Turtle的移动方式
        self.forward(20)
        screen.update()

    def go_down(self):
        # 使用backward代替直接修改ycor
        self.backward(20)
        screen.update()

# --- Screen Setup ---
screen = Screen()
screen.setup(width=800, height=600)
screen.bgcolor('black')
screen.title("My PONGIE")
screen.tracer(0) # 关闭自动刷新，手动控制更新

# --- Game Objects ---
r_paddle = Paddle()
r_paddle.setx(350) # 直接设置x坐标
l_paddle = Paddle()
l_paddle.setx(-350) # 直接设置x坐标

the_ball = Ball()
score = Scoreboard()

# --- Event Listeners ---
screen.onkey(r_paddle.go_up, 'Up')
screen.onkey(r_paddle.go_down, 'Down')
screen.onkey(l_paddle.go_up, 'w')
screen.onkey(l_paddle.go_down, 's')
screen.listen()

# --- Game Loop (using ontimer) ---
def play():
    the_ball.move()

    # 墙壁碰撞检测
    if not -280 < the_ball.ycor() < 280:
        the_ball.y_bounce()
    # 挡板碰撞检测 (已修正逻辑)
    # 使用or连接左右两边的判断，确保任何一边碰撞都反弹
    elif (the_ball.distance(r_paddle) < 50 and the_ball.xcor() > 320) or \
         (the_ball.distance(l_paddle) < 50 and the_ball.xcor() < -320):
        the_ball.x_bounce()
    # 球出右边界
    elif the_ball.xcor() > 380:
        the_ball.reset_position()
        score.left_point()
    # 球出左边界
    elif the_ball.xcor() < -380:
        the_ball.reset_position()
        score.right_point()

    # 每100毫秒（0.1秒）调用一次play函数，实现动画循环
    screen.ontimer(play, 100)

# 初始屏幕更新，显示所有对象
screen.update()

# 启动游戏循环
play()

# 保持窗口打开，直到手动关闭
screen.mainloop()