太空射击第16课： 道具（Part 2）

这是我们“Shmup”项目的第13部分。如果您尚未通读前面的部分，请从第 1 部分开始。在本课中，我们将添加一些偶尔出现的道具。

视频

您可以在此处观看本课程的视频：

武器道具

上一次，我们创建了一个道具精灵，当流星被摧毁时，它会从流星中随机掉落。我们完成了'shield'类型生命值的工作，现在我们需要对'gun'类型执行相同的操作。

我们可以选择很多东西来影响枪支道具：射速，伤害（尽管现在我们一击摧毁流星），枪支类型等。在本课中，我们将让玩家射击更多的子弹，但是为了让我们可以灵活地在以后根据需要更改它，我们将定义Player一个新方法'gun'，并在获取道具时调用它：

    if hit.type == 'gun':
        player.powerup()
1
2

为了实现这一点，首先让我们向Player精灵添加一些新属性：跟踪power的“power level功率级别”（每个pow可以提高一个级别），这样我们就可以在一定power_time时间后回落：

    self.power = 1
    self.power_time = pygame.time.get_ticks()
1
2

powerup方法将设置以下属性：

def powerup(self):
    self.power += 1
    self.power_time = pygame.time.get_ticks()
1
2
3

现在我们可以改变shoot方法，在power大于1时产生2发子弹。我们将使它们在翼尖处生成。

def shoot(self):
    now = pygame.time.get_ticks()
    if now - self.last_shot > self.shoot_delay:
        self.last_shot = now
        if self.power == 1:
            bullet = Bullet(self.rect.centerx, self.rect.top)
            all_sprites.add(bullet)
            bullets.add(bullet)
            shoot_sound.play()
        if self.power >= 2:
            bullet1 = Bullet(self.rect.left, self.rect.centery)
            bullet2 = Bullet(self.rect.right, self.rect.centery)
            all_sprites.add(bullet1)
            all_sprites.add(bullet2)
            bullets.add(bullet1)
            bullets.add(bullet2)
            shoot_sound.play()
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17

最后，我们需要将检查power_time添加到玩家的update：

# timeout for powerups
if self.power >= 2 and pygame.time.get_ticks() - self.power_time > POWERUP_TIME:
    self.power -= 1
    self.power_time = pygame.time.get_ticks()
1
2
3
4

不要忘记在顶部设置POWERUP_TIME为5000（5秒）。

道具的声音

为了总结道具功能，我们需要一些漂亮的声音来播放，当我们拿起物品时。我将把它留给你补充。使用“bfxr”找到两个你喜欢的声音，并像加载其他声音一样加载它们，将它们命名为类似shield_sound和power_sound。然后，只需在相应的pow类型发生碰撞时播放每个声音即可。您可以在下面看到完整的游戏代码，但在查看之前，请尝试使其正常工作。

下次，我们将通过添加“游戏结束”屏幕来完成游戏。

此部分的完整代码

# KidsCanCode - Game Development with Pygame video series
# Shmup game - part 13
# Video link: https://www.youtube.com/watch?v=y2w-116htIQ
# Powerups (part 2)
# Frozen Jam by tgfcoder  licensed under CC-BY-3
# Art from Kenney.nl
import pygame
import random
from os import path

img_dir = path.join(path.dirname(__file__), 'img')
snd_dir = path.join(path.dirname(__file__), 'snd')

WIDTH = 480
HEIGHT = 600
FPS = 60
POWERUP_TIME = 5000

# define colors
WHITE = (255, 255, 255)
BLACK = (0, 0, 0)
RED = (255, 0, 0)
GREEN = (0, 255, 0)
BLUE = (0, 0, 255)
YELLOW = (255, 255, 0)

# initialize pygame and create window
pygame.init()
pygame.mixer.init()
screen = pygame.display.set_mode((WIDTH, HEIGHT))
pygame.display.set_caption("Shmup!")
clock = pygame.time.Clock()

font_name = pygame.font.match_font('arial')
def draw_text(surf, text, size, x, y):
    font = pygame.font.Font(font_name, size)
    text_surface = font.render(text, True, WHITE)
    text_rect = text_surface.get_rect()
    text_rect.midtop = (x, y)
    surf.blit(text_surface, text_rect)

def newmob():
    m = Mob()
    all_sprites.add(m)
    mobs.add(m)

def draw_shield_bar(surf, x, y, pct):
    if pct < 0:
        pct = 0
    BAR_LENGTH = 100
    BAR_HEIGHT = 10
    fill = (pct / 100) * BAR_LENGTH
    outline_rect = pygame.Rect(x, y, BAR_LENGTH, BAR_HEIGHT)
    fill_rect = pygame.Rect(x, y, fill, BAR_HEIGHT)
    pygame.draw.rect(surf, GREEN, fill_rect)
    pygame.draw.rect(surf, WHITE, outline_rect, 2)

def draw_lives(surf, x, y, lives, img):
    for i in range(lives):
        img_rect = img.get_rect()
        img_rect.x = x + 30 * i
        img_rect.y = y
        surf.blit(img, img_rect)

class Player(pygame.sprite.Sprite):
    def __init__(self):
        pygame.sprite.Sprite.__init__(self)
        self.image = pygame.transform.scale(player_img, (50, 38))
        self.image.set_colorkey(BLACK)
        self.rect = self.image.get_rect()
        self.radius = 20
        # pygame.draw.circle(self.image, RED, self.rect.center, self.radius)
        self.rect.centerx = WIDTH / 2
        self.rect.bottom = HEIGHT - 10
        self.speedx = 0
        self.shield = 100
        self.shoot_delay = 250
        self.last_shot = pygame.time.get_ticks()
        self.lives = 3
        self.hidden = False
        self.hide_timer = pygame.time.get_ticks()
        self.power = 1
        self.power_time = pygame.time.get_ticks()

    def update(self):
        # timeout for powerups
        if self.power >= 2 and pygame.time.get_ticks() - self.power_time > POWERUP_TIME:
            self.power -= 1
            self.power_time = pygame.time.get_ticks()

        # unhide if hidden
        if self.hidden and pygame.time.get_ticks() - self.hide_timer > 1000:
            self.hidden = False
            self.rect.centerx = WIDTH / 2
            self.rect.bottom = HEIGHT - 10

        self.speedx = 0
        keystate = pygame.key.get_pressed()
        if keystate[pygame.K_LEFT]:
            self.speedx = -8
        if keystate[pygame.K_RIGHT]:
            self.speedx = 8
        if keystate[pygame.K_SPACE]:
            self.shoot()
        self.rect.x += self.speedx
        if self.rect.right > WIDTH:
            self.rect.right = WIDTH
        if self.rect.left < 0:
            self.rect.left = 0

    def powerup(self):
        self.power += 1
        self.power_time = pygame.time.get_ticks()

    def shoot(self):
        now = pygame.time.get_ticks()
        if now - self.last_shot > self.shoot_delay:
            self.last_shot = now
            if self.power == 1:
                bullet = Bullet(self.rect.centerx, self.rect.top)
                all_sprites.add(bullet)
                bullets.add(bullet)
                shoot_sound.play()
            if self.power >= 2:
                bullet1 = Bullet(self.rect.left, self.rect.centery)
                bullet2 = Bullet(self.rect.right, self.rect.centery)
                all_sprites.add(bullet1)
                all_sprites.add(bullet2)
                bullets.add(bullet1)
                bullets.add(bullet2)
                shoot_sound.play()

    def hide(self):
        # hide the player temporarily
        self.hidden = True
        self.hide_timer = pygame.time.get_ticks()
        self.rect.center = (WIDTH / 2, HEIGHT + 200)

class Mob(pygame.sprite.Sprite):
    def __init__(self):
        pygame.sprite.Sprite.__init__(self)
        self.image_orig = random.choice(meteor_images)
        self.image_orig.set_colorkey(BLACK)
        self.image = self.image_orig.copy()
        self.rect = self.image.get_rect()
        self.radius = int(self.rect.width * .85 / 2)
        # pygame.draw.circle(self.image, RED, self.rect.center, self.radius)
        self.rect.x = random.randrange(WIDTH - self.rect.width)
        self.rect.bottom = random.randrange(-80, -20)
        self.speedy = random.randrange(1, 8)
        self.speedx = random.randrange(-3, 3)
        self.rot = 0
        self.rot_speed = random.randrange(-8, 8)
        self.last_update = pygame.time.get_ticks()

    def rotate(self):
        now = pygame.time.get_ticks()
        if now - self.last_update > 50:
            self.last_update = now
            self.rot = (self.rot + self.rot_speed) % 360
            new_image = pygame.transform.rotate(self.image_orig, self.rot)
            old_center = self.rect.center
            self.image = new_image
            self.rect = self.image.get_rect()
            self.rect.center = old_center

    def update(self):
        self.rotate()
        self.rect.x += self.speedx
        self.rect.y += self.speedy
        if self.rect.top > HEIGHT + 10 or self.rect.left < -100 or self.rect.right > WIDTH + 100:
            self.rect.x = random.randrange(WIDTH - self.rect.width)
            self.rect.y = random.randrange(-100, -40)
            self.speedy = random.randrange(1, 8)

class Bullet(pygame.sprite.Sprite):
    def __init__(self, x, y):
        pygame.sprite.Sprite.__init__(self)
        self.image = bullet_img
        self.image.set_colorkey(BLACK)
        self.rect = self.image.get_rect()
        self.rect.bottom = y
        self.rect.centerx = x
        self.speedy = -10

    def update(self):
        self.rect.y += self.speedy
        # kill if it moves off the top of the screen
        if self.rect.bottom < 0:
            self.kill()

class Pow(pygame.sprite.Sprite):
    def __init__(self, center):
        pygame.sprite.Sprite.__init__(self)
        self.type = random.choice(['shield', 'gun'])
        self.image = powerup_images[self.type]
        self.image.set_colorkey(BLACK)
        self.rect = self.image.get_rect()
        self.rect.center = center
        self.speedy = 5

    def update(self):
        self.rect.y += self.speedy
        # kill if it moves off the top of the screen
        if self.rect.top > HEIGHT:
            self.kill()

class Explosion(pygame.sprite.Sprite):
    def __init__(self, center, size):
        pygame.sprite.Sprite.__init__(self)
        self.size = size
        self.image = explosion_anim[self.size][0]
        self.rect = self.image.get_rect()
        self.rect.center = center
        self.frame = 0
        self.last_update = pygame.time.get_ticks()
        self.frame_rate = 75

    def update(self):
        now = pygame.time.get_ticks()
        if now - self.last_update > self.frame_rate:
            self.last_update = now
            self.frame += 1
            if self.frame == len(explosion_anim[self.size]):
                self.kill()
            else:
                center = self.rect.center
                self.image = explosion_anim[self.size][self.frame]
                self.rect = self.image.get_rect()
                self.rect.center = center

# Load all game graphics
background = pygame.image.load(path.join(img_dir, "starfield.png")).convert()
background_rect = background.get_rect()
player_img = pygame.image.load(path.join(img_dir, "playerShip1_orange.png")).convert()
player_mini_img = pygame.transform.scale(player_img, (25, 19))
player_mini_img.set_colorkey(BLACK)
bullet_img = pygame.image.load(path.join(img_dir, "laserRed16.png")).convert()
meteor_images = []
meteor_list = ['meteorBrown_big1.png', 'meteorBrown_med1.png', 'meteorBrown_med1.png',
               'meteorBrown_med3.png', 'meteorBrown_small1.png', 'meteorBrown_small2.png',
               'meteorBrown_tiny1.png']
for img in meteor_list:
    meteor_images.append(pygame.image.load(path.join(img_dir, img)).convert())
explosion_anim = {}
explosion_anim['lg'] = []
explosion_anim['sm'] = []
explosion_anim['player'] = []
for i in range(9):
    filename = 'regularExplosion0{}.png'.format(i)
    img = pygame.image.load(path.join(img_dir, filename)).convert()
    img.set_colorkey(BLACK)
    img_lg = pygame.transform.scale(img, (75, 75))
    explosion_anim['lg'].append(img_lg)
    img_sm = pygame.transform.scale(img, (32, 32))
    explosion_anim['sm'].append(img_sm)
    filename = 'sonicExplosion0{}.png'.format(i)
    img = pygame.image.load(path.join(img_dir, filename)).convert()
    img.set_colorkey(BLACK)
    explosion_anim['player'].append(img)
powerup_images = {}
powerup_images['shield'] = pygame.image.load(path.join(img_dir, 'shield_gold.png')).convert()
powerup_images['gun'] = pygame.image.load(path.join(img_dir, 'bolt_gold.png')).convert()


# Load all game sounds
shoot_sound = pygame.mixer.Sound(path.join(snd_dir, 'pew.wav'))
shield_sound = pygame.mixer.Sound(path.join(snd_dir, 'pow4.wav'))
power_sound = pygame.mixer.Sound(path.join(snd_dir, 'pow5.wav'))
expl_sounds = []
for snd in ['expl3.wav', 'expl6.wav']:
    expl_sounds.append(pygame.mixer.Sound(path.join(snd_dir, snd)))
player_die_sound = pygame.mixer.Sound(path.join(snd_dir, 'rumble1.ogg'))
pygame.mixer.music.load(path.join(snd_dir, 'tgfcoder-FrozenJam-SeamlessLoop.ogg'))
pygame.mixer.music.set_volume(0.4)

all_sprites = pygame.sprite.Group()
mobs = pygame.sprite.Group()
bullets = pygame.sprite.Group()
powerups = pygame.sprite.Group()
player = Player()
all_sprites.add(player)
for i in range(8):
    newmob()

score = 0
pygame.mixer.music.play(loops=-1)
# Game loop
running = True
while running:
    # keep loop running at the right speed
    clock.tick(FPS)
    # Process input (events)
    for event in pygame.event.get():
        # check for closing window
        if event.type == pygame.QUIT:
            running = False

    # Update
    all_sprites.update()

    # check to see if a bullet hit a mob
    hits = pygame.sprite.groupcollide(mobs, bullets, True, True)
    for hit in hits:
        score += 50 - hit.radius
        random.choice(expl_sounds).play()
        expl = Explosion(hit.rect.center, 'lg')
        all_sprites.add(expl)
        if random.random() > 0.9:
            pow = Pow(hit.rect.center)
            all_sprites.add(pow)
            powerups.add(pow)
        newmob()

    # check to see if a mob hit the player
    hits = pygame.sprite.spritecollide(player, mobs, True, pygame.sprite.collide_circle)
    for hit in hits:
        player.shield -= hit.radius * 2
        expl = Explosion(hit.rect.center, 'sm')
        all_sprites.add(expl)
        newmob()
        if player.shield <= 0:
            player_die_sound.play()
            death_explosion = Explosion(player.rect.center, 'player')
            all_sprites.add(death_explosion)
            player.hide()
            player.lives -= 1
            player.shield = 100

    # check to see if player hit a powerup
    hits = pygame.sprite.spritecollide(player, powerups, True)
    for hit in hits:
        if hit.type == 'shield':
            player.shield += random.randrange(10, 30)
            shield_sound.play()
            if player.shield >= 100:
                player.shield = 100
        if hit.type == 'gun':
            player.powerup()
            power_sound.play()

    # if the player died and the explosion has finished playing
    if player.lives == 0 and not death_explosion.alive():
        running = False

    # Draw / render
    screen.fill(BLACK)
    screen.blit(background, background_rect)
    all_sprites.draw(screen)
    draw_text(screen, str(score), 18, WIDTH / 2, 10)
    draw_shield_bar(screen, 5, 5, player.shield)
    draw_lives(screen, WIDTH - 100, 5, player.lives, player_mini_img)
    # *after* drawing everything, flip the display
    pygame.display.flip()

pygame.quit()
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356

第14部分：游戏结束屏幕