92 《零基礎入門學習Python》筆記 第092講：Pygame：飛機大戰3

當敵我兩機發生碰撞時，兩方應該是玉石俱焚的，現在我為每一個類增加撞擊時發生的慘烈畫面，比如：

敵人1：

敵人2：

敵人3：

我：

我們現在就來寫代碼：

首先為每一個類把這些圖片加進去：

#myplane.py 部分代码








import pygame

















class Myplane(pygame.sprite.Sprite):








def __init__(self, bg_size):








pygame.sprite.Sprite.__init__(self)

















self.image1 = pygame.image.load("images/me1.png").convert_alpha()








self.image2 = pygame.image.load("images/me2.png").convert_alpha()








#添加坠机图片








self.destroy_images = []








self.destroy_images.extend([\








pygame.image.load("images/me_destroy_1.png").convert_alpha(), \








pygame.image.load("images/me_destroy_2.png").convert_alpha(), \








pygame.image.load("images/me_destroy_3.png").convert_alpha(), \








pygame.image.load("images/me_destroy_4.png").convert_alpha() \








])








self.rect = self.image1.get_rect()








self.width, self.height = bg_size[0], bg_size[1]








self.rect.left, self.rect.top = \








(self.width - self.rect.width) // 2, \








self.height - self.rect.height - 60  #减60，留给状态栏








self.speed = 10

#enemy.py








import pygame








from random import *

















class SmallEnemy(pygame.sprite.Sprite):








def __init__(self, bg_size):








pygame.sprite.Sprite.__init__(self)

















self.image = pygame.image.load("images/enemy1.png").convert_alpha()








#添加坠机图片








self.destroy_images = []








self.destroy_images.extend([\








pygame.image.load("images/enemy1_down1.png").convert_alpha(), \








pygame.image.load("images/enemy1_down2.png").convert_alpha(), \








pygame.image.load("images/enemy1_down3.png").convert_alpha(), \








pygame.image.load("images/enemy1_down4.png").convert_alpha() \








])








self.rect = self.image.get_rect()








self.width, self.height = bg_size[0], bg_size[1]








self.speed = 2        








self.rect.left, self.rect.top = \








randint(0, self.width - self.rect.width), \








randint(-5 * self.height, 0)  #在页面外部上方5个屏幕高度范围内随机生成一个敌机      

















def move(self):








if self.rect.top < self.height:








self.rect.top += self.speed








else:








self.reset()

















def reset(self):        








self.rect.left, self.rect.top = \








randint(0, self.width - self.rect.width), \








randint(-5 * self.height, 0)

















class MidEnemy(pygame.sprite.Sprite):    








def __init__(self, bg_size):








pygame.sprite.Sprite.__init__(self)

















self.image = pygame.image.load("images/enemy2.png").convert_alpha()








#添加坠机图片








self.destroy_images = []








self.destroy_images.extend([\








pygame.image.load("images/enemy2_down1.png").convert_alpha(), \








pygame.image.load("images/enemy2_down2.png").convert_alpha(), \








pygame.image.load("images/enemy2_down3.png").convert_alpha(), \








pygame.image.load("images/enemy2_down4.png").convert_alpha() \








])








self.rect = self.image.get_rect()








self.width, self.height = bg_size[0], bg_size[1]








self.speed = 1








self.rect.left, self.rect.top = \








randint(0, self.width - self.rect.width), \








randint(-10 * self.height, -self.height) #在页面外部上方1个到10个屏幕高度范围内随机生成一个敌机（1-10个，就保证了不会一开始出大一个大的）

















def move(self):








if self.rect.top < self.height:








self.rect.top += self.speed








else:








self.reset()

















def reset(self):








self.rect.left, self.rect.top = \








randint(0, self.width - self.rect.width), \








randint(-10 * self.height, -self.height)

















class BigEnemy(pygame.sprite.Sprite):    








def __init__(self, bg_size):








pygame.sprite.Sprite.__init__(self)

















#大型敌机有飞行特效，两张图片切换








self.image1 = pygame.image.load("images/enemy3_n1.png").convert_alpha()








self.image2 = pygame.image.load("images/enemy3_n2.png").convert_alpha()








#添加坠机图片








self.destroy_images = []








self.destroy_images.extend([\








pygame.image.load("images/enemy3_down1.png").convert_alpha(), \








pygame.image.load("images/enemy3_down2.png").convert_alpha(), \








pygame.image.load("images/enemy3_down3.png").convert_alpha(), \








pygame.image.load("images/enemy3_down4.png").convert_alpha(), \








pygame.image.load("images/enemy3_down5.png").convert_alpha(), \








pygame.image.load("images/enemy3_down6.png").convert_alpha() \








])








self.rect = self.image1.get_rect()








self.width, self.height = bg_size[0], bg_size[1]








self.speed = 1








self.rect.left, self.rect.top = \








randint(0, self.width - self.rect.width), \








randint(-15 * self.height, -5 * self.height) #在页面外部上方5-15个屏幕高度范围内随机生成一个敌机

















def move(self):








if self.rect.top < self.height:








self.rect.top += self.speed








else:








self.reset()

















def reset(self):








self.rect.left, self.rect.top = \








randint(0, self.width - self.rect.width), \








randint(-15 * self.height, -5 * self.height)

接下來我們要為每一個類添加active 屬性，該屬性表示還活著，也就是說，當該屬性的值為True 時，我們就讓飛機顯示正常的飛行狀態，而當該屬性為False 時，表示該飛機已經遇難了，我們就要依次顯示墜機的畫面，顯示完之後，調用該類的resert() 方法。

self.active = True

接下來修改main 模塊的main() 函數，在繪製每一種飛機時，先檢測它的active 的值：

#main.py 部分代码








#中弹图片索引








e1_destroy_index = 0








e2_destroy_index = 0








e3_destroy_index = 0








me_destroy_index = 0








(此处代码省略)








#绘制大型敌机








for each in big_enemies:








if each.active: #检测是否还活着








each.move()








if switch_image:








screen.blit(each.image1, each.rect)








else:








screen.blit(each.image2, each.rect)








#即将出现在界面中，播放音效








if each.rect.bottom > -50:








enemy3_fly_sound.play()








else:








#坠机








enemy3_down_sound.play() #音效








if not(delay % 3):








screen.blit(each.destroy_images[e3_destroy_index], each.rect)








e3_destroy_index = (e3_destroy_index + 1) % 6








if e3_destroy_index == 0:








each.reset()

















（其他敌机和我方飞机代码类似。。。。。）

我們接著就要寫碰撞檢測代碼：

一旦我方飛機碰撞到敵機，導致的結果必將是敵我同歸於盡。

#main.py 部分代码








#检测我方飞机是否被撞








enemies_down = pygame.sprite.spritecollide(me, enemies, False)








if enemies_down:








me.active = False








for e in enemies_down:








e.active = False

我們碰撞檢測使用 spritecollide() 方法：

碰撞和墜機是實現了，但是我們發現，兩個飛機還沒真正的接觸就已經撞上了，這是為什麼呢？

這是因為我們使用了普通的spritecollide() 方法，這個方法默認情況下是以圖片的矩形位置區域作為檢測的範圍，而我們飛機的矩形範圍遠大於自身，但是我們完全是可以做得更好的，我們可以做到完美的碰撞檢測，怎麼實現呢？

sprite 模塊裡有一個叫做collide_mask 的函數可以利用，這個函數要求檢測對象擁有一個mask 屬性，這個屬性就是用於指定檢測的範圍，關於mask，Pygame 還專門寫了一個mask 模塊，其中有一個叫做from_surface( ) 的函數，可以將Surface 對像中非透明的部分標記為mask 並返回。

首先，給每個類加上mask 屬性：

self.mask = pygame.mask.from_sueface(self.image) #将非透明部分标记为mask

然後在main 函數中修改碰撞檢測代碼，指定檢測方法為 pygame.sprite.collide_mask，即：

#main.py








#检测我方飞机是否被撞








enemies_down = pygame.sprite.spritecollide(me, enemies, False, pygame.sprite.collide_mask)








if enemies_down:








me.active = False








for e in enemies_down:








e.active = False

好了，這就是完美的碰撞檢測了，在大部分情況下編寫遊戲開發，基本上都是使用這種碰撞檢測。

現在，有人就可能已經發現了，剛才我們的代碼實際上是存在很明顯的Bug，導致部分音效無法正常播放，

大家知道是為什麼嗎？可以看一下這裡的代碼：

#绘制大型敌机








for each in big_enemies:








if each.active: #检测是否还活着








each.move()








if switch_image:








screen.blit(each.image1, each.rect)








else:








screen.blit(each.image2, each.rect)








#即将出现在界面中，播放音效








if each.rect.bottom > -50:








enemy3_fly_sound.play()








else:








#坠机








enemy3_down_sound.play() #音效








if not(delay % 3):








screen.blit(each.destroy_images[e3_destroy_index], each.rect)








e3_destroy_index = (e3_destroy_index + 1) % 6








if e3_destroy_index == 0:








each.reset()

大家看看，不管是我們的飛機，還是敵機，它們是怎麼墜機的，首先，我們檢測active，如果為False 的話，就播放音效，然後畫一張墜機圖，這樣就一幀過去了，然後第二幀，又播放音效，畫圖的進不去，然後第三幀，播放音效，然後畫下面的一張墜機圖。

大家發現問題沒有，你要畫它墜機的圖片，需要好多幀，但是這裡你重複的播放了好多次它墜機的音效，一個飛機墜機只需要播放一次音效即可，你要播放很多次，導致的結果就是你把所有音效的通道都佔滿了，因為Pygame 默認只有8條音效的通道。

我們現在要做的就是讓它只播放一次。修改如下：

#绘制大型敌机








for each in big_enemies:








if each.active: #检测是否还活着








each.move()








if switch_image:








screen.blit(each.image1, each.rect)








else:








screen.blit(each.image2, each.rect)








#即将出现在界面中，播放音效








if each.rect.bottom > -50:








enemy3_fly_sound.play()








else:








#坠机                                








if not(delay % 3):








if e3_destroy_index == 0:








enemy3_down_sound.play() #音效








screen.blit(each.destroy_images[e3_destroy_index], each.rect)








e3_destroy_index = (e3_destroy_index + 1) % 6








if e3_destroy_index == 0:








each.reset()

現在再來測試一下就好多了，當然，如果你嫌默認的8個音效通道太少的話，可以使用mixer模塊的set_ num _channels()方法來設置通道數多一點。

下面貼出這節課實現的3個模塊的完整代碼：

#main.py








import pygame








import sys








import traceback #为了更好地退出








import myplane








import enemy

















from pygame.locals import *

















pygame.init()








pygame.mixer.init()  #混音器初始化

















bg_size = width, height = 480, 700








screen = pygame.display.set_mode(bg_size)








pygame.display.set_caption("飞机大战 -- Python Demo")

















background = pygame.image.load("images/background.png").convert()

















# 载入游戏音乐








pygame.mixer.music.load("sound/game_music.ogg")








pygame.mixer.music.set_volume(0.2)








bullet_sound = pygame.mixer.Sound("sound/bullet.wav")








bullet_sound.set_volume(0.2)








bomb_sound = pygame.mixer.Sound("sound/use_bomb.wav")








bomb_sound.set_volume(0.2)








supply_sound = pygame.mixer.Sound("sound/supply.wav")








supply_sound.set_volume(0.2)








get_bomb_sound = pygame.mixer.Sound("sound/get_bomb.wav")








get_bomb_sound.set_volume(0.2)








get_bullet_sound = pygame.mixer.Sound("sound/get_bullet.wav")








get_bullet_sound.set_volume(0.2)








upgrade_sound = pygame.mixer.Sound("sound/upgrade.wav")








upgrade_sound.set_volume(0.2)








enemy3_fly_sound = pygame.mixer.Sound("sound/enemy3_flying.wav")








enemy3_fly_sound.set_volume(0.5)








enemy1_down_sound = pygame.mixer.Sound("sound/enemy1_down.wav")








enemy1_down_sound.set_volume(0.2)








enemy2_down_sound = pygame.mixer.Sound("sound/enemy2_down.wav")








enemy2_down_sound.set_volume(0.2)








enemy3_down_sound = pygame.mixer.Sound("sound/enemy3_down.wav")








enemy3_down_sound.set_volume(0.5)








me_down_sound = pygame.mixer.Sound("sound/me_down.wav")








me_down_sound.set_volume(0.2)

















def add_small_enemies(group1, group2, num):








for i in range(num):








e1 = enemy.SmallEnemy(bg_size)








group1.add(e1)








group2.add(e1)

















def add_mid_enemies(group1, group2, num):








for i in range(num):








e2 = enemy.MidEnemy(bg_size)








group1.add(e2)








group2.add(e2)

















def add_big_enemies(group1, group2, num):








for i in range(num):








e3 = enemy.BigEnemy(bg_size)








group1.add(e3)








group2.add(e3)

















def main():








pygame.mixer.music.play(-1)

















# 生成我方飞机








me = myplane.Myplane(bg_size)

















#生成敌方飞机








enemies = pygame.sprite.Group()

















# 生成敌方小型飞机








small_enemies = pygame.sprite.Group()








add_small_enemies(small_enemies, enemies, 15)

















# 生成敌方中型飞机








mid_enemies = pygame.sprite.Group()








add_mid_enemies(mid_enemies, enemies, 4)

















# 生成敌方大型飞机








big_enemies = pygame.sprite.Group()








add_big_enemies(big_enemies, enemies, 2)

















#中弹图片索引








e1_destroy_index = 0








e2_destroy_index = 0








e3_destroy_index = 0








me_destroy_index = 0

















clock = pygame.time.Clock()

















#用于切换图片








switch_image = True

















#用于延迟








delay = 100

















running = True

















while running:








for event in pygame.event.get():








if event.type == QUIT:








pygame.quit()








sys.exit()

















#检测用户的键盘操作








key_pressed = pygame.key.get_pressed()

















if key_pressed[K_w] or key_pressed[K_UP]:








me.moveUp()








if key_pressed[K_s] or key_pressed[K_DOWN]:








me.moveDown()








if key_pressed[K_a] or key_pressed[K_LEFT]:








me.moveLeft()








if key_pressed[K_d] or key_pressed[K_RIGHT]:








me.moveRight()                        

















screen.blit(background, (0, 0))

















#绘制大型敌机








for each in big_enemies:








if each.active: #检测是否还活着








each.move()








if switch_image:








screen.blit(each.image1, each.rect)








else:








screen.blit(each.image2, each.rect)








#即将出现在界面中，播放音效








if each.rect.bottom == -50:








enemy3_fly_sound.play(-1) #循环播放








else:








#坠机








if not(delay % 3):








if e3_destroy_index == 0:








enemy3_down_sound.play()








screen.blit(each.destroy_images[e3_destroy_index], each.rect)








e3_destroy_index = (e3_destroy_index + 1) % 6








if e3_destroy_index == 0:








enemy3_fly_sound.stop() #循环音效停止播放








each.reset()

















#绘制中型敌机








for each in mid_enemies:








if each.active: #检测是否还活着








each.move()                     








screen.blit(each.image, each.rect)








else:








#坠机








if not(delay % 3):








if e2_destroy_index == 0:








enemy2_down_sound.play() #音效








screen.blit(each.destroy_images[e2_destroy_index], each.rect)








e2_destroy_index = (e2_destroy_index + 1) % 4








if e2_destroy_index == 0:








each.reset()

















#绘制小型敌机








for each in small_enemies:








if each.active: #检测是否还活着








each.move()                     








screen.blit(each.image, each.rect)








else:








#坠机








if not(delay % 3):








if e1_destroy_index == 0:








enemy1_down_sound.play() #音效                                








screen.blit(each.destroy_images[e1_destroy_index], each.rect)








e1_destroy_index = (e1_destroy_index + 1) % 4








if e1_destroy_index == 0:








each.reset()

















#检测我方飞机是否被撞








enemies_down = pygame.sprite.spritecollide(me, enemies, False, pygame.sprite.collide_mask)








if enemies_down:








#me.active = False








for e in enemies_down:








e.active = False


























#绘制我方飞机








if me.active: #检测是否还活着








if switch_image:








screen.blit(me.image1, me.rect)








else:








screen.blit(me.image2, me.rect)








else:








#坠机








if not(delay % 3):








if me_destroy_index == 0:








me_down_sound.play()                        








screen.blit(me.destroy_images[me_destroy_index], me.rect)








me_destroy_index = (me_destroy_index + 1) % 4








if me_destroy_index == 0:








print("game over")








running = False

















#切换图片








if not(delay % 5):  #5帧切换一次，一秒就只切换12次








switch_image = not switch_image                        

















delay -= 1








if not delay:








delay = 100

















pygame.display.flip()

















clock.tick(60)

















if __name__ == "__main__":








try:








main()








except SystemExit:








pass








except:








traceback.print_exc()








pygame.quit()








input()

#myplane.py








import pygame

















class Myplane(pygame.sprite.Sprite):








def __init__(self, bg_size):








pygame.sprite.Sprite.__init__(self)

















self.image1 = pygame.image.load("images/me1.png").convert_alpha()








self.image2 = pygame.image.load("images/me2.png").convert_alpha()








#添加坠机图片








self.destroy_images = []








self.destroy_images.extend([\








pygame.image.load("images/me_destroy_1.png").convert_alpha(), \








pygame.image.load("images/me_destroy_2.png").convert_alpha(), \








pygame.image.load("images/me_destroy_3.png").convert_alpha(), \








pygame.image.load("images/me_destroy_4.png").convert_alpha() \








])








self.rect = self.image1.get_rect()








self.width, self.height = bg_size[0], bg_size[1]








self.rect.left, self.rect.top = \








(self.width - self.rect.width) // 2, \








self.height - self.rect.height - 60  #减60，留给状态栏








self.speed = 10








self.active = True








self.mask = pygame.mask.from_surface(self.image1) #将非透明部分标记为mask

















def moveUp(self):








if self.rect.top > 0:








self.rect.top -= self.speed








else:








self.rect.top = 0

















def moveDown(self):








if self.rect.bottom < self.height - 60:








self.rect.top += self.speed








else:








self.rect.bottom = self.height - 60

















def moveLeft(self):








if self.rect.left > 0:








self.rect.left -= self.speed








else:








self.rect.left = 0

















def moveRight(self):








if self.rect.right < self.width:








self.rect.left += self.speed








else:








self.rect.right = self.width

#enemy.py








import pygame








from random import *

















class SmallEnemy(pygame.sprite.Sprite):








def __init__(self, bg_size):








pygame.sprite.Sprite.__init__(self)

















self.image = pygame.image.load("images/enemy1.png").convert_alpha()








#添加坠机图片








self.destroy_images = []








self.destroy_images.extend([\








pygame.image.load("images/enemy1_down1.png").convert_alpha(), \








pygame.image.load("images/enemy1_down2.png").convert_alpha(), \








pygame.image.load("images/enemy1_down3.png").convert_alpha(), \








pygame.image.load("images/enemy1_down4.png").convert_alpha() \








])








self.rect = self.image.get_rect()








self.width, self.height = bg_size[0], bg_size[1]








self.speed = 2








self.active = True








self.rect.left, self.rect.top = \








randint(0, self.width - self.rect.width), \








randint(-5 * self.height, 0)  #在页面外部上方5个屏幕高度范围内随机生成一个敌机








self.mask = pygame.mask.from_surface(self.image) #将非透明部分标记为mask

















def move(self):








if self.rect.top < self.height:








self.rect.top += self.speed








else:








self.reset()

















def reset(self):








self.active = True








self.rect.left, self.rect.top = \








randint(0, self.width - self.rect.width), \








randint(-5 * self.height, 0)

















class MidEnemy(pygame.sprite.Sprite):    








def __init__(self, bg_size):








pygame.sprite.Sprite.__init__(self)

















self.image = pygame.image.load("images/enemy2.png").convert_alpha()








#添加坠机图片








self.destroy_images = []








self.destroy_images.extend([\








pygame.image.load("images/enemy2_down1.png").convert_alpha(), \








pygame.image.load("images/enemy2_down2.png").convert_alpha(), \








pygame.image.load("images/enemy2_down3.png").convert_alpha(), \








pygame.image.load("images/enemy2_down4.png").convert_alpha() \








])








self.rect = self.image.get_rect()








self.width, self.height = bg_size[0], bg_size[1]








self.speed = 1








self.active = True








self.rect.left, self.rect.top = \








randint(0, self.width - self.rect.width), \








randint(-10 * self.height, -self.height) #在页面外部上方1个到10个屏幕高度范围内随机生成一个敌机（1-10个，就保证了不会一开始出大一个大的）








self.mask = pygame.mask.from_surface(self.image) #将非透明部分标记为mask

















def move(self):








if self.rect.top < self.height:








self.rect.top += self.speed








else:








self.reset()

















def reset(self):








self.active = True








self.rect.left, self.rect.top = \








randint(0, self.width - self.rect.width), \








randint(-10 * self.height, -self.height)

















class BigEnemy(pygame.sprite.Sprite):    








def __init__(self, bg_size):








pygame.sprite.Sprite.__init__(self)

















#大型敌机有飞行特效，两张图片切换








self.image1 = pygame.image.load("images/enemy3_n1.png").convert_alpha()








self.image2 = pygame.image.load("images/enemy3_n2.png").convert_alpha()








#添加坠机图片








self.destroy_images = []








self.destroy_images.extend([\








pygame.image.load("images/enemy3_down1.png").convert_alpha(), \








pygame.image.load("images/enemy3_down2.png").convert_alpha(), \








pygame.image.load("images/enemy3_down3.png").convert_alpha(), \








pygame.image.load("images/enemy3_down4.png").convert_alpha(), \








pygame.image.load("images/enemy3_down5.png").convert_alpha(), \








pygame.image.load("images/enemy3_down6.png").convert_alpha() \








])








self.rect = self.image1.get_rect()








self.width, self.height = bg_size[0], bg_size[1]








self.speed = 1








self.active = True








self.rect.left, self.rect.top = \








randint(0, self.width - self.rect.width), \








randint(-15 * self.height, -5 * self.height) #在页面外部上方5-15个屏幕高度范围内随机生成一个敌机








self.mask = pygame.mask.from_surface(self.image1) #将非透明部分标记为mask

















def move(self):








if self.rect.top < self.height:








self.rect.top += self.speed








else:








self.reset()

















def reset(self):








self.active = True








self.rect.left, self.rect.top = \








randint(0, self.width - self.rect.width), \








randint(-15 * self.height, -5 * self.height)

（未完待續）