星际巡逻音效
本课属于 Coddy Pygame 学习旅程的“音效与游戏体验”单元。第 20 课,共 23 课。
第 3 单元的 Star Patrol 已经可以运行,但没有声音。这一章会为它添加本单元的声音和氛围,先从音效和音乐开始。
每种声音都对应游戏中已有的一个时刻:
- 添加激光时:
laser.ogg,音量要小,因为它每秒会播放好几次; - 激光击毁敌人时:
explosion.ogg; - 失去生命时,在两个位置都播放:
hit.ogg。
音乐会跟随游戏状态变化。level.ogg 从开始时循环播放。清除最后一波敌人时,胜利旋律开始播放:
if not enemies:
wave += 1
if wave < len(WAVES):
...
else:
play_music("assets/music/win.ogg", 0)
if lives <= 0:
play_music("assets/music/lose.ogg", 0)这两行都位于 update 中,只有游戏进行时才会运行。游戏结束的那一帧,它们会运行一次;从下一帧开始,update 就会跳过,因此不会再次启动旋律。
挑战
中等为 Star Patrol 添加音效和音乐。
- 从
assets/sounds/加载laser.ogg(音量为 0.4)、explosion.ogg和hit.ogg;分别在发射激光、消灭敌人和每损失一条命时播放它们。 - 编写
play_music(path, loops=-1);以 0.5 的音乐音量播放assets/music/level.ogg。 - 获胜时播放一次
win.ogg,失败时播放一次lose.ogg,这两个文件都在assets/music/中。
按“开始”并射击:你会听到音乐中的激光声。然后按“检查”。
亲手试试
import random
import pygame
pygame.init()
screen = pygame.display.set_mode((640, 480))
pygame.display.set_caption("Star Patrol")
clock = pygame.time.Clock()
font = pygame.font.Font(None, 32)
ship_image = pygame.image.load("assets/images/ship.png").convert_alpha()
laser_image = pygame.image.load("assets/images/laser.png").convert_alpha()
red_image = pygame.image.load("assets/images/enemy_red.png").convert_alpha()
green_image = pygame.image.load("assets/images/enemy_green.png").convert_alpha()
yellow_image = pygame.image.load("assets/images/enemy_yellow.png").convert_alpha()
explosion_frames = []
for number in range(1, 5):
explosion_frames.append(pygame.image.load(f"assets/images/explosion_{number}.png").convert_alpha())
WAVES = [(red_image, 6, 2), (green_image, 8, 2), (yellow_image, 10, 3)]
class Player(pygame.sprite.Sprite):
def __init__(self):
super().__init__()
self.image = ship_image
self.rect = self.image.get_rect(midbottom=(320, 470))
self.mask = pygame.mask.from_surface(self.image)
def update(self):
keys = pygame.key.get_pressed()
if keys[pygame.K_LEFT]:
self.rect.x -= 6
if keys[pygame.K_RIGHT]:
self.rect.x += 6
self.rect.clamp_ip(screen.get_rect())
class Laser(pygame.sprite.Sprite):
def __init__(self, x, y):
super().__init__()
self.image = laser_image
self.rect = self.image.get_rect(midbottom=(x, y))
self.mask = pygame.mask.from_surface(self.image)
def update(self):
self.rect.y -= 10
if self.rect.bottom < 0:
self.kill()
class Enemy(pygame.sprite.Sprite):
def __init__(self, image, x, y, speed):
super().__init__()
self.image = image
self.rect = self.image.get_rect(center=(x, y))
self.mask = pygame.mask.from_surface(self.image)
self.speed = speed
def update(self):
self.rect.y += self.speed
class Explosion(pygame.sprite.Sprite):
def __init__(self, center):
super().__init__()
self.index = 0
self.timer = 0
self.image = explosion_frames[0]
self.rect = self.image.get_rect(center=center)
def update(self):
self.timer += 1
if self.timer == 5:
self.timer = 0
self.index += 1
if self.index == len(explosion_frames):
self.kill()
else:
self.image = explosion_frames[self.index]
def spawn_wave(image, count, speed):
for i in range(count):
x = random.randint(40, 600)
enemies.add(Enemy(image, x, -40 - i * 120, speed))
player = Player()
lasers = pygame.sprite.Group()
enemies = pygame.sprite.Group()
explosions = pygame.sprite.Group()
last_shot = 0
score = 0
lives = 3
wave = 0
image, count, speed = WAVES[wave]
spawn_wave(image, count, speed)
running = True
while running:
for event in pygame.event.get():
if event.type == pygame.QUIT:
running = False
if lives > 0 and wave < len(WAVES):
player.update()
keys = pygame.key.get_pressed()
now = pygame.time.get_ticks()
if keys[pygame.K_SPACE] and now - last_shot >= 250:
lasers.add(Laser(player.rect.centerx, player.rect.top))
last_shot = now
lasers.update()
enemies.update()
for enemy in enemies:
if enemy.rect.top > 480:
enemy.kill()
lives -= 1
hits = pygame.sprite.groupcollide(enemies, lasers, True, True, pygame.sprite.collide_mask)
for enemy in hits:
score += 10
explosions.add(Explosion(enemy.rect.center))
crashes = pygame.sprite.spritecollide(player, enemies, True, pygame.sprite.collide_mask)
for enemy in crashes:
lives -= 1
explosions.add(Explosion(enemy.rect.center))
if not enemies:
wave += 1
if wave < len(WAVES):
image, count, speed = WAVES[wave]
spawn_wave(image, count, speed)
explosions.update()
screen.fill((12, 14, 30))
enemies.draw(screen)
lasers.draw(screen)
screen.blit(player.image, player.rect)
explosions.draw(screen)
score_text = font.render(f"Score: {score}", True, (240, 240, 240))
screen.blit(score_text, (10, 10))
lives_text = font.render(f"Lives: {max(lives, 0)}", True, (240, 240, 240))
screen.blit(lives_text, lives_text.get_rect(topright=(630, 10)))
if wave < len(WAVES):
wave_text = font.render(f"Wave {wave + 1}", True, (240, 240, 240))
screen.blit(wave_text, wave_text.get_rect(midtop=(320, 10)))
if lives <= 0:
message = font.render("Game over", True, (240, 240, 240))
screen.blit(message, message.get_rect(center=(320, 240)))
elif wave == len(WAVES):
message = font.render("You win!", True, (240, 240, 240))
screen.blit(message, message.get_rect(center=(320, 240)))
pygame.display.flip()
clock.tick(60)
pygame.quit()
音效与游戏体验中的所有课
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