【Pygame 第10课】 命中目标

花花啊

我的飞机打中之后没有被重置是为什么？
# -*- coding: utf-8 -*-
import pygame, random
from sys import exit





class Bullet:
    def __init__(self):
        self.x = 0
        self.y = -1
        self.image = pygame.image.load('bullet.png').convert_alpha()
        self.active = False

    def move(self):
        if self.active:
            self.y -= 3
        if self.y < 0:
            self.active = False

    def restart(self):
        mouseX, mouseY = pygame.mouse.get_pos()
        self.x = mouseX - self.image.get_width() / 2
        self.y = mouseY - self.image.get_height() / 2
        self.active = True


class Enemy:
    def restart(self):
        self.x = random.randint(50, 800)
        self.y = random.randint(-200, -50)
        self.speed = random.random() + 0.1

    def __init__(self):
        self.restart()
        self.image = pygame.image.load('enemy.png').convert_alpha()

    def move(self):
        if self.y < 800:
            self.y += self.speed
        else:
            self.restart()

def checkHit(enemy, bullet):
    if (bullet.x > enemy.x and bullet.x < enemy.x + enemy.image.get_width()) and (
            bullet.y > enemy.y and bullet.y < enemy.y + enemy.image.get_height()):
        enemy.restart()
        bullet.active = False


pygame.init()
screen = pygame.display.set_mode((450, 800), 0, 32)
pygame.display.set_caption("Hello, World!")
background = pygame.image.load('back.jpg').convert()
plane = pygame.image.load('plane.png').convert_alpha()
# 创建子弹的list
bullets = []
# 向list添加5发子弹
for i in range(5):
    bullets.append(Bullet())
# 子弹总个数
count_b = len(bullets)
# 即将激发的子弹序号
index_b = 0
# 发射子弹的间隔
interval_b = 0
# 创建敌机的list
enemies = []
# 向list中添加5架敌机
for i in range(5):
    enemies.append(Enemy())
while True:
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            pygame.quit()
            exit()
    screen.blit(background, (0, 0))
    interval_b -= 1
    if interval_b < 0:
        bullets[index_b].restart()
        interval_b = 100
        index_b = (index_b + 1) % count_b
    for b in bullets:
        #处于激活状态的子弹，移动位置并绘制
        if b.active:
            b.move()
            screen.blit(b.image, (b.x, b.y))
    for b in bullets:
        if b.active:
            for e in enemies:
                checkHit(e, b)
    # 处理每架敌机的运动
    for e in enemies:
        e.move()
        screen.blit(e.image, (e.x, e.y))
    x, y = pygame.mouse.get_pos()
    x -= plane.get_width() / 2
    y -= plane.get_height() / 2
    screen.blit(plane, (x, y))
    pygame.display.update()