34 lines
1.0 KiB
Python
34 lines
1.0 KiB
Python
import pygame
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from pygame.sprite import Sprite
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class Bullet(Sprite):
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"""一个对飞船发射的子弹进行管理的类"""
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def __init__(self, ai_settings, screen, ship):
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"""在飞船所处的位置创建一个子弹对象"""
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super().__init__()
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self.screen = screen
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# 在(0,0)处创建一个表示子弹的矩形，再设置正确的位置
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self.rect = pygame.Rect(0, 0, ai_settings.bullet_width, ai_settings.bullet_height)
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self.rect.centerx = ship.rect.centerx
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self.rect.bottom = ship.rect.top
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# 存储用小数表示的子弹位置
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self.y = float(self.rect.y)
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# 设置子弹颜色及速度(从ai_settings中读取)
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self.color = ai_settings.bullet_color
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self.speed_factor = ai_settings.bullet_speed_factor
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def update(self):
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"""向上移动子弹"""
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self.y -= self.speed_factor
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self.rect.y = self.y
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def draw_bullet(self):
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"""在屏幕上绘制子弹"""
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pygame.draw.rect(self.screen, self.color, self.rect)
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