Breakout游戏手柄适配问题：松开按键后Paddle自动左移至边界

我基于Code with Giovanni的Breakout代码修改适配游戏手柄后，出现如下问题：运行游戏时，未按压手柄左右按键时，Paddle会自动移动至左侧墙壁；按压手柄按键时可正常控制Paddle移动，但松开按键后问题复现。修改后的代码如下：

import pygame


pygame.init()
pygame.mixer.init()

WIDTH = 893
HEIGHT = 1000
size = (WIDTH, HEIGHT)
screen = pygame.display.set_mode(size)
pygame.display.set_caption("Breakout 1976")
clock = pygame.time.Clock()
FPS = 60

WHITE = (255, 255, 255)
GREY = (212, 210, 212)
BLACK = (0, 0, 0)
BLUE = (0, 97, 148)

RED = (162, 8, 0)
ORANGE = (183, 119, 0)
GREEN = (0, 127, 33)
YELLOW = (197, 199, 37)

score = 0
balls = 1
velocity = 4

paddle_width = 65
paddle_height = 20

all_sprites_list = pygame.sprite.Group()

# Controller

if pygame.joystick.get_count() > 0:
    joystick = pygame.joystick.Joystick(0)
    joystick.init()


brick_sound = pygame.mixer.Sound('sounds/brick.wav')
paddle_sound = pygame.mixer.Sound('sounds/paddle.wav')
wall_sound = pygame.mixer.Sound('sounds/wall.wav')


class Brick(pygame.sprite.Sprite):

    def __init__(self, color, width, height):
        super().__init__()
        self.image = pygame.Surface([width, height])
        pygame.draw.rect(self.image, color, [0, 0, width, height])
        self.rect = self.image.get_rect()


class Paddle(pygame.sprite.Sprite):

    def __init__(self, color, width, height):
        super().__init__()
        self.image = pygame.Surface([width, height])
        pygame.draw.rect(self.image, color, [0, 0, width, height])
        self.rect = self.image.get_rect()

    def moveRight(self, pixels):
        self.rect.x += pixels
        if self.rect.x > WIDTH - wall_width - paddle_width:
            self.rect.x = WIDTH - wall_width - paddle_width

    def moveLeft(self, pixels):
        self.rect.x -= pixels
        if self.rect.x < wall_width:
            self.rect.x = wall_width


class Ball(pygame.sprite.Sprite):

    def __init__(self, color, width, height):
        super().__init__()
        self.image = pygame.Surface([width, height])
        pygame.draw.rect(self.image, color, [0, 0, width, height])
        self.rect = self.image.get_rect()
        self.velocity = [velocity, velocity]

    def update(self):
        self.rect.x += self.velocity[0]
        self.rect.y += self.velocity[1]

    def bounce(self):
        self.velocity[0] = self.velocity[0]
        self.velocity[1] = -self.velocity[1]


paddle = Paddle(BLUE, paddle_width, paddle_height)
paddle.rect.x = WIDTH // 2 - paddle_width // 2
paddle.rect.y = HEIGHT - 65

ball = Ball(WHITE, 10, 10)
ball.rect.x = WIDTH // 2 - 5
ball.rect.y = HEIGHT // 2 - 5

all_bricks = pygame.sprite.Group()

brick_width = 55
brick_height = 16
x_gap = 7
y_gap = 5
wall_width = 16


def bricks():
    for j in range(8):
        for i in range(14):
            if j < 2:
                if i == 0:
                    brick = Brick(RED, brick_width, brick_height)
                    brick.rect.x = wall_width
                    brick.rect.y = 215 + j * (y_gap + brick_height)
                    all_sprites_list.add(brick)
                    all_bricks.add(brick)
                else:
                    brick = Brick(RED, brick_width, brick_height)
                    brick.rect.x = wall_width + brick_width + x_gap + (i - 1) * (brick_width + x_gap)
                    brick.rect.y = 215 + j * (y_gap + brick_height)
                    all_sprites_list.add(brick)
                    all_bricks.add(brick)
            if 1 < j < 4:
                if i == 0:
                    brick = Brick(ORANGE, brick_width, brick_height)
                    brick.rect.x = wall_width
                    brick.rect.y = 215 + j * (y_gap + brick_height)
                    all_sprites_list.add(brick)
                    all_bricks.add(brick)
                else:
                    brick = Brick(ORANGE, brick_width, brick_height)
                    brick.rect.x = wall_width + brick_width + x_gap + (i - 1) * (brick_width + x_gap)
                    brick.rect.y = 215 + j * (y_gap + brick_height)
                    all_sprites_list.add(brick)
                    all_bricks.add(brick)
            if 3 < j < 6:
                if i == 0:
                    brick = Brick(GREEN, brick_width, brick_height)
                    brick.rect.x = wall_width
                    brick.rect.y = 215 + j * (y_gap + brick_height)
                    all_sprites_list.add(brick)
                    all_bricks.add(brick)
                else:
                    brick = Brick(GREEN, brick_width, brick_height)
                    brick.rect.x = wall_width + brick_width + x_gap + (i - 1) * (brick_width + x_gap)
                    brick.rect.y = 215 + j * (y_gap + brick_height)
                    all_sprites_list.add(brick)
                    all_bricks.add(brick)
            if 5 < j < 8:
                if i == 0:
                    brick = Brick(YELLOW, brick_width, brick_height)
                    brick.rect.x = wall_width
                    brick.rect.y = 215 + j * (y_gap + brick_height)
                    all_sprites_list.add(brick)
                    all_bricks.add(brick)
                else:
                    brick = Brick(YELLOW, brick_width, brick_height)
                    brick.rect.x = wall_width + brick_width + x_gap + (i - 1) * (brick_width + x_gap)
                    brick.rect.y = 215 + j * (y_gap + brick_height)
                    all_sprites_list.add(brick)
                    all_bricks.add(brick)


brick_wall = bricks()

all_sprites_list.add(paddle)
all_sprites_list.add(ball)


def main(score, balls):

    step = 0

    run = True
    while run:

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

###### GAME PAD CONTROLLER ############

        axis_x = (joystick.get_axis(0))
        if  abs(axis_x) > 0.1:
            paddle.moveRight(10)
        if  abs(axis_x) < 0.1:
            paddle.moveLeft(10)      

        all_sprites_list.update()

        if ball.rect.y < 40:
            ball.velocity[1] = -ball.velocity[1]
            wall_sound.play()

        if ball.rect.x >= WIDTH - wall_width - 10:
            ball.velocity[0] = -ball.velocity[0]
            wall_sound.play()

        if ball.rect.x <= wall_width:
            ball.velocity[0] = -ball.velocity[0]
            wall_sound.play()

        if ball.rect.y > HEIGHT:
            ball.rect.x = WIDTH // 2 - 5
            ball.rect.y = HEIGHT // 2 - 5
            ball.velocity[1] = ball.velocity[1]
            balls += 1
            if balls == 4:
                font = pygame.font.Font('text_style/DSEG14Classic-Bold.ttf', 50)
                text = font.render("GAME OVER", 1, WHITE)
                text_rect = text.get_rect(center=(WIDTH / 2, HEIGHT / 2))
                screen.blit(text, text_rect)
                pygame.display.update()
                pygame.time.wait(2000)
                run = False

        if pygame.sprite.collide_mask(ball, paddle):
            ball.rect.x += ball.velocity[0]
            ball.rect.y -= ball.velocity[1]
            ball.bounce()
            paddle_sound.play()

        brick_collision_list = pygame.sprite.spritecollide(ball, all_bricks, False)
        for brick in brick_collision_list:
            ball.bounce()
            brick_sound.play()
            if len(brick_collision_list) > 0:
                step += 1
                for i in range(0, 448, 28):
                    if step == i:
                        ball.velocity[0] += 1
                        ball.velocity[1] += 1
            if 380.5 > brick.rect.y > 338.5:
                score += 1
                brick.kill()
            elif 338.5 > brick.rect.y > 294:
                score += 3
                brick.kill()
            elif 294 > brick.rect.y > 254.5:
                score += 5
                brick.kill()
            else:
                score += 7
                brick.kill()
            if len(all_bricks) == 0:
                font = pygame.font.Font('text_style/DSEG14Classic-Bold.ttf', 50)
                text = font.render("SCREEN CLEARED", 1, WHITE)
                text_rect = text.get_rect(center=(WIDTH / 2, HEIGHT / 2))
                all_sprites_list.add(ball)
                screen.blit(text, text_rect)
                pygame.display.update()
                pygame.time.wait(2000)
                run = False

        screen.fill(BLACK)

        pygame.draw.line(screen, GREY, [0, 19], [WIDTH, 19], 40)
        pygame.draw.line(screen, GREY, [(wall_width / 2) - 1, 0], [(wall_width / 2) - 1, HEIGHT], wall_width)
        pygame.draw.line(screen, GREY, [(WIDTH - wall_width / 2) - 1, 0], [(WIDTH - wall_width / 2) - 1, HEIGHT], wall_width)

        pygame.draw.line(screen, BLUE, [(wall_width / 2) - 1, HEIGHT - 65 + paddle_height / 2 - 54 / 2], [(wall_width / 2) - 1, HEIGHT - 65 + paddle_height / 2 - 54 / 2 + 54], wall_width)
        pygame.draw.line(screen, BLUE, [(WIDTH - wall_width / 2) - 1, HEIGHT - 65 + paddle_height / 2 - 54 / 2], [(WIDTH - wall_width / 2) - 1, HEIGHT - 65 + paddle_height / 2 - 54 / 2 + 54], wall_width)

        pygame.draw.line(screen, RED, [(wall_width / 2) - 1, 212.5], [(wall_width / 2) - 1, 212.5 + 2 * brick_height + 2 * y_gap], wall_width)
        pygame.draw.line(screen, RED, [(WIDTH - wall_width / 2) - 1, 212.5], [(WIDTH - wall_width / 2) - 1, 212.5 + 2 * brick_height + 2 * y_gap], wall_width)

        pygame.draw.line(screen, ORANGE, [(wall_width / 2) - 1, 212.5 + 2 * brick_height + 2 * y_gap], [(wall_width / 2) - 1, 212.5 + 4 * brick_height + 4 * y_gap], wall_width)
        pygame.draw.line(screen, ORANGE, [(WIDTH - wall_width / 2) - 1, 212.5 + 2 * brick_height + 2 * y_gap], [(WIDTH - wall_width / 2) - 1, 212.5 + 4 * brick_height + 4 * y_gap], wall_width)

        pygame.draw.line(screen, GREEN, [(wall_width / 2) - 1, 212.5 + 4 * brick_height + 4 * y_gap], [(wall_width / 2) - 1, 212.5 + 6 * brick_height + 6 * y_gap], wall_width)
        pygame.draw.line(screen, GREEN, [(WIDTH - wall_width / 2) - 1, 212.5 + 4 * brick_height + 4 * y_gap], [(WIDTH - wall_width / 2) - 1, 212.5 + 6 * brick_height + 6 * y_gap], wall_width)

        pygame.draw.line(screen, YELLOW, [(wall_width / 2) - 1, 212.5 + 6 * brick_height + 6 * y_gap], [(wall_width / 2) - 1, 212.5 + 8 * brick_height + 8 * y_gap], wall_width)
        pygame.draw.line(screen, YELLOW, [(WIDTH - wall_width / 2) - 1, 212.5 + 6 * brick_height + 6 * y_gap], [(WIDTH - wall_width / 2) - 1, 212.5 + 8 * brick_height + 8 * y_gap], wall_width)

        font = pygame.font.Font('text_style/DSEG14Classic-Bold.ttf', 70)
        text = font.render(str(f"{score:03}"), 1, WHITE)
        screen.blit(text, (80, 120))
        text = font.render(str(balls), 1, WHITE)
        screen.blit(text, (520, 41))
        text = font.render('000', 1, WHITE)
        screen.blit(text, (580, 120))
        text = font.render('1', 1, WHITE)
        screen.blit(text, (20, 40))

        all_sprites_list.draw(screen)

        pygame.display.update()

        clock.tick(FPS)

    pygame.quit()


main(score, balls)

你写的手柄控制逻辑完全错误：

• 当摇杆X轴有输入（绝对值>0.1）时，不管向左还是向右，都只执行向右移动
• 当摇杆无输入（绝对值<0.1）时，反而执行向左移动，这就是松开按键后Paddle自动往左边跑的核心原因

把原手柄控制部分的代码替换成下面这段：

###### GAME PAD CONTROLLER ############
axis_x = joystick.get_axis(0)
deadzone = 0.1  # 死区，过滤摇杆微小偏移
if axis_x > deadzone:
    # 摇杆向右推，控制Paddle右移
    paddle.moveRight(10)
elif axis_x < -deadzone:
    # 摇杆向左推，控制Paddle左移
    paddle.moveLeft(10)
# 无输入时什么都不做，Paddle保持原地

• 可以根据摇杆偏移量动态调整移动速度，让操控更顺滑，比如改成：paddle.moveRight(int(axis_x * 15))
• 加个手柄未连接时的判断，避免没插手柄时程序崩溃

内容的提问来源于stack exchange，提问作者TMC FAMILY