为子弹创建粒子轨迹

Question

我正在创建一个太空射击游戏，其中每次用户单击鼠标左键时，宇宙飞船都会发射子弹，因为我希望子弹更漂亮，所以我希望它们在发射后在其后面有一条粒子轨迹。我对我的代码进行了一些尝试（最终成为我将在下面显示的代码），但结果并不好。

1. 颗粒继续粘在子弹上。
2. 只出现了一个粒子。

我应该怎么做才能解决这个问题？这是我的代码：

bullet_surf = pygame.image.load('graphics for b/beam.png')
bullet_surf = pygame.transform.rotozoom(bullet_surf,0,0.08)
bullets = []
while True:
....    
    for event in pygame.event.get():
        if event.type == pygame.MOUSEBUTTONDOWN:
            if event.button == 1:
                bullets.append([[*ship_rect.midright],6,[random.randint(-20,20)/10,random.randint(-20,20)/10]])
    
    for b in range(len(bullets)):
        bullets [b][0][0] +=20
    
    for bullet in bullets[:]:
        if bullet [0][0] > 1100:
            bullets.remove(bullet)
    
    for bullet in bullets:
        bullet_rect = bullet_surf.get_rect(midleft = (bullet[0][0],bullet[0][1]))
        screen.blit(bullet_surf,bullet_rect)
        bullet_rect.centerx += bullet[2][0]
        bullet_rect.centery += bullet[2][1]
        bullet[1] -= 0.1
        print(bullet_rect.center)
        pygame.draw.circle(screen,(255,255,255),bullet_rect.center,int(bullet[1])) 

Answer 1

您需要为每个子弹创建一个粒子列表。我建议为项目符号使用一个类：

self.particles = []

将新粒子添加到列表中，并在子弹移动时为列表中的粒子设置动画：

for particle in self.particles:
    particle[0][0] -= 2
    particle[0][1] += particle[1]
particle = [list(self.rect.midleft), random.uniform(-2, 2), pygame.Color(255, random.randrange(255), 0)]
self.particles.append(particle)
if len(self.particles) > 30:
    self.particles.pop(0)

循环绘制列表中的所有粒子：

for i, particle in enumerate(self.particles):
    pygame.draw.circle(screen, particle[2], particle[0], (i//3+2))

最小的例子

import pygame, random

pygame.init()
window = pygame.display.set_mode((400, 200))
clock = pygame.time.Clock()

class Bullet:
    def __init__(self, x, y):
        self.image = pygame.image.load("rocket.png")
        self.rect = self.image.get_rect(center = (x, y))
        self.particles = []

    def move(self):
        for particle in self.particles:
            particle[0][0] -= 2
            particle[0][1] += particle[1]
        particle = [list(self.rect.midleft), random.uniform(-2, 2), pygame.Color(255, random.randrange(255), 0)]
        self.particles.append(particle)
        if len(self.particles) > 30:
            self.particles.pop(0)
        self.rect.centerx += 3

    def draw(self, screen):
        for i, particle in enumerate(self.particles):
            pygame.draw.circle(screen, particle[2], particle[0], (i//3+2))
        screen.blit(self.image, self.rect)
        

background = pygame.Surface(window.get_size())
ts, w, h, c1, c2 = 50, *background.get_size(), (32, 32, 32), (64, 64, 64)
tiles = [((x*ts, y*ts, ts, ts), c1 if (x+y) % 2 == 0 else c2) for x in range((w+ts-1)//ts) for y in range((h+ts-1)//ts)]
[pygame.draw.rect(background, color, rect) for rect, color in tiles] 

bullet = Bullet(0, 100)

run = True
while run:
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            run = False 
        
    bullet.move()
    if bullet.rect.left >= 400:
        bullet.rect.right = 0

    window.blit(background, (0, 0))
    bullet.draw(window)
    pygame.display.flip()
    clock.tick(100)

pygame.quit()
exit()

通过鼠标点击发射子弹的示例：

import pygame, random

pygame.init()
window = pygame.display.set_mode((400, 400))
clock = pygame.time.Clock()

class Bullet:
    def __init__(self, x, y):
        self.image = pygame.image.load("rocket.png")
        self.rect = self.image.get_rect(center = (x, y))
        self.particles = []

    def move(self):
        for particle in self.particles:
            particle[0][0] -= 2
            particle[0][1] += particle[1]
        particle = [list(self.rect.midleft), random.uniform(-2, 2), pygame.Color(255, random.randrange(255), 0)]
        self.particles.append(particle)
        if len(self.particles) > 30:
            self.particles.pop(0)
        self.rect.centerx += 3

    def draw(self, screen):
        for i, particle in enumerate(self.particles):
            pygame.draw.circle(screen, particle[2], particle[0], (i//3+2))
        screen.blit(self.image, self.rect)
        

background = pygame.Surface(window.get_size())
ts, w, h, c1, c2 = 50, *background.get_size(), (32, 32, 32), (64, 64, 64)
tiles = [((x*ts, y*ts, ts, ts), c1 if (x+y) % 2 == 0 else c2) for x in range((w+ts-1)//ts) for y in range((h+ts-1)//ts)]
[pygame.draw.rect(background, color, rect) for rect, color in tiles] 

bullets = []    

run = True
while run:
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            run = False 
        if event.type == pygame.MOUSEBUTTONDOWN:
            bullets.append(Bullet(*event.pos))

    for bullet in bullets[:]:     
        bullet.move()
        if bullet.rect.left >= 400:
            bullets.remove(bullet)

    window.blit(background, (0, 0))
    for bullet in bullets[:]:    
        bullet.draw(window)
    pygame.display.flip()
    clock.tick(100)

pygame.quit()
exit()