python - 我如何检测pygame中的碰撞？

Question

我已经使用下面的类制作了一个子弹列表和一个 Sprite 列表。如何检测子弹是否与 sprite 发生碰撞，然后删除该 sprite 和子弹？

#Define the sprite class
class Sprite:

    def __init__(self,x,y, name):
        self.x=x

        self.y=y

        self.image = pygame.image.load(name)

        self.rect = self.image.get_rect()

    def render(self):
        window.blit(self.image, (self.x,self.y))


# Define the bullet class to create bullets          
class Bullet:

    def __init__(self,x,y):
        self.x = x + 23
        self.y = y
        self.bullet = pygame.image.load("user_bullet.BMP")
        self.rect = self.bullet.get_rect()

    def render(self):
        window.blit(self.bullet, (self.x, self.y))

Answer 1

在 PyGame 中，碰撞检测是使用 pygame.Rect 完成的对象。 Rect 对象提供了多种方法来检测对象之间的碰撞。即使是矩形和圆形物体(例如桨和球)之间的碰撞也可以通过两个矩形物体(桨和球的边界矩形)之间的碰撞来检测。

一些例子:

• pygame.Rect.collidepoint :

  Test if a point is inside a rectangle

  repl.it/@Rabbid76/PyGame-collidepoint

  

  import pygame
  
  pygame.init()
  window = pygame.display.set_mode((250, 250))
  rect = pygame.Rect(*window.get_rect().center, 0, 0).inflate(100, 100)
  
  run = True
  while run:
      for event in pygame.event.get():
          if event.type == pygame.QUIT:
              run = False
  
      point = pygame.mouse.get_pos()
      collide = rect.collidepoint(point)
      color = (255, 0, 0) if collide else (255, 255, 255)
  
      window.fill(0)
      pygame.draw.rect(window, color, rect)
      pygame.display.flip()
  
  pygame.quit()
  exit()
  

• pygame.Rect.colliderect

  Test if two rectangles overlap

  另见 How to detect collisions between two rectangular objects or images in pygame

  repl.it/@Rabbid76/PyGame-colliderect

  

  import pygame
  
  pygame.init()
  window = pygame.display.set_mode((250, 250))
  rect1 = pygame.Rect(*window.get_rect().center, 0, 0).inflate(75, 75)
  rect2 = pygame.Rect(0, 0, 75, 75)
  
  run = True
  while run:
      for event in pygame.event.get():
          if event.type == pygame.QUIT:
              run = False
  
      rect2.center = pygame.mouse.get_pos()
      collide = rect1.colliderect(rect2)
      color = (255, 0, 0) if collide else (255, 255, 255)
  
      window.fill(0)
      pygame.draw.rect(window, color, rect1)
      pygame.draw.rect(window, (0, 255, 0), rect2, 6, 1)
      pygame.display.flip()
  
  pygame.quit()
  exit()
  

此外，pygame.Rect.collidelist和 pygame.Rect.collidelistall可用于矩形与矩形列表之间的碰撞测试。 pygame.Rect.collidedict和 pygame.Rect.collidedictall可用于矩形与矩形字典的碰撞测试。

碰撞pygame.sprite.Sprite和 pygame.sprite.Group对象，可以通过 pygame.sprite.spritecollide() 检测到, pygame.sprite.groupcollide()或 pygame.sprite.spritecollideany() .使用这些方法时，可以通过 collided 参数指定碰撞检测算法:

The collided argument is a callback function used to calculate if two sprites are colliding.

可能的碰撞 可调用项是 collide_rect , collide_rect_ratio , collide_circle , collide_circle_ratio , collide_mask

一些例子:

• pygame.sprite.spritecollide()

  repl.it/@Rabbid76/PyGame-spritecollide

  

  import pygame
  
  pygame.init()
  window = pygame.display.set_mode((250, 250))
  
  sprite1 = pygame.sprite.Sprite()
  sprite1.image = pygame.Surface((75, 75))
  sprite1.image.fill((255, 0, 0))
  sprite1.rect = pygame.Rect(*window.get_rect().center, 0, 0).inflate(75, 75)
  sprite2 = pygame.sprite.Sprite()
  sprite2.image = pygame.Surface((75, 75))
  sprite2.image.fill((0, 255, 0))
  sprite2.rect = pygame.Rect(*window.get_rect().center, 0, 0).inflate(75, 75)
  
  all_group = pygame.sprite.Group([sprite2, sprite1])
  test_group = pygame.sprite.Group(sprite2)
  
  run = True
  while run:
      for event in pygame.event.get():
          if event.type == pygame.QUIT:
              run = False
  
      sprite1.rect.center = pygame.mouse.get_pos()
      collide = pygame.sprite.spritecollide(sprite1, test_group, False)
  
      window.fill(0)
      all_group.draw(window)
      for s in collide:
          pygame.draw.rect(window, (255, 255, 255), s.rect, 5, 1)
      pygame.display.flip()
  
  pygame.quit()
  exit()
  

有关与面具的碰撞，请参阅 How can I make a collision mask?或 Pygame mask collision

另见 Collision and Intersection

• pygame.sprite.spritecollide()/collide_circle

  repl.it/@Rabbid76/PyGame-spritecollidecollidecircle

  

  import pygame
  
  pygame.init()
  window = pygame.display.set_mode((250, 250))
  
  sprite1 = pygame.sprite.Sprite()
  sprite1.image = pygame.Surface((80, 80), pygame.SRCALPHA)
  pygame.draw.circle(sprite1.image, (255, 0, 0), (40, 40), 40)
  sprite1.rect = pygame.Rect(*window.get_rect().center, 0, 0).inflate(40, 40)
  sprite2 = pygame.sprite.Sprite()
  sprite2.image = pygame.Surface((80, 89), pygame.SRCALPHA)
  pygame.draw.circle(sprite2.image, (0, 255, 0), (40, 40), 40)
  sprite2.rect = pygame.Rect(*window.get_rect().center, 0, 0).inflate(80, 80)
  
  all_group = pygame.sprite.Group([sprite2, sprite1])
  test_group = pygame.sprite.Group(sprite2)
  
  run = True
  while run:
      for event in pygame.event.get():
          if event.type == pygame.QUIT:
              run = False
  
      sprite1.rect.center = pygame.mouse.get_pos()
      collide = pygame.sprite.spritecollide(sprite1, test_group, False, pygame.sprite.collide_circle)
  
      window.fill(0)
      all_group.draw(window)
      for s in collide:
          pygame.draw.circle(window, (255, 255, 255), s.rect.center, s.rect.width // 2, 5)
      pygame.display.flip()
  
  pygame.quit()
  exit()
  

---

这对您的代码意味着什么？

pygame.Surface.get_rect.get_rect()返回一个具有 Surface 对象大小的矩形，该矩形始终从 (0, 0) 开始，因为 Surface 对象没有位置。矩形的位置可以由关键字参数指定。例如，矩形的中心可以用关键字参数 center 指定。这些关键字参数应用于 pygame.Rect 的属性在返回之前(参见 pygame.Rect 以获取关键字参数列表)。
参见 * Why is my collision test always returning 'true' and why is the position of the rectangle of the image always wrong (0, 0)?

您根本不需要Sprite 和Bullet 的x 和y 属性。使用 rect 属性的位置代替:

#Define the sprite class
class Sprite:
    def __init__(self, x, y, name):
        self.image = pygame.image.load(name)
        self.rect = self.image.get_rect(topleft = (x, y))

    def render(self):
        window.blit(self.image, self.rect)

# Define the bullet class to create bullets          
class Bullet:
    def __init__(self, x, y):
        self.bullet = pygame.image.load("user_bullet.BMP")
        self.rect = self.bullet.get_rect(topleft = (x + 23, y))

    def render(self):
        window.blit(self.bullet, self.rect)

使用pygame.Rect.colliderect()检测 Sprite 和 Bullet 实例之间的碰撞。
参见 How to detect collisions between two rectangular objects or images in pygame :

my_sprite = Sprite(sx, sy, name)
my_bullet = Bullet(by, by)

while True:
    # [...]

    if my_sprite.rect.colliderect(my_bullet.rect):
        printe("hit")