Pygame：Sprite 侧面碰撞

Question

pygame 中有没有办法在 pygame 中寻找精灵的特定侧面和另一个精灵的特定侧面之间的碰撞？ 例如，如果精灵 A 的顶部与精灵 B 的底部碰撞，则返回 True。

我确信有一种方法可以做到这一点，但我在文档中找不到任何特定的方法。

谢谢！

Answer 1

PyGame 中没有获得侧面碰撞的功能。

但是你可以尝试使用pygame.Rect.collidepoint来测试A.rect.midleft , A.rect.midright , A.rect.midtop , A.rect.midbottom , A.rect.topleft , A.rect.bottomleft , A.rect.topright , A.rect.bottomright在B.rect ( pygame.Rect ) 内。

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编辑：

示例代码。 使用箭头移动玩家并接触敌人。

（可能不是最佳解决方案）

import pygame

WHITE = (255,255,255)
BLACK = (0  ,0  ,0  )
RED   = (255,0  ,0  )
GREEN = (0  ,255,0  )
BLUE  = (0  ,0  ,255)

class Player():

    def __init__(self, x=0, y=0, width=150, height=150):

        self.rect = pygame.Rect(x, y, width, height)

        self.speed_x = 5
        self.speed_y = 5

        self.move_x = 0
        self.move_y = 0

        self.collision = [False] * 9

        self.font = pygame.font.SysFont("", 32)
        self.text = "";

    def set_center(self, screen):
        self.rect.center = screen.get_rect().center

    def event_handler(self, event):
        if event.type == pygame.KEYDOWN:
            if event.key == pygame.K_LEFT:
                self.move_x -= self.speed_x
            elif event.key == pygame.K_RIGHT:
                self.move_x += self.speed_x
            elif event.key == pygame.K_UP:
                self.move_y -= self.speed_y
            elif event.key == pygame.K_DOWN:
                self.move_y += self.speed_y

        elif event.type == pygame.KEYUP:
            if event.key == pygame.K_LEFT:
                self.move_x += self.speed_x
            elif event.key == pygame.K_RIGHT:
                self.move_x -= self.speed_x
            elif event.key == pygame.K_UP:
                self.move_y += self.speed_y
            elif event.key == pygame.K_DOWN:
                self.move_y -= self.speed_y

    def update(self):
        self.rect.x += self.move_x
        self.rect.y += self.move_y

    def draw(self, screen):

        pygame.draw.rect(screen, WHITE, self.rect, 2)
        self.draw_point(screen, self.rect.topleft, self.collision[0])
        self.draw_point(screen, self.rect.topright, self.collision[1])
        self.draw_point(screen, self.rect.bottomleft, self.collision[2])
        self.draw_point(screen, self.rect.bottomright, self.collision[3])

        self.draw_point(screen, self.rect.midleft, self.collision[4])
        self.draw_point(screen, self.rect.midright, self.collision[5])
        self.draw_point(screen, self.rect.midtop, self.collision[6])
        self.draw_point(screen, self.rect.midbottom, self.collision[7])

        self.draw_point(screen, self.rect.center, self.collision[8])

    def draw_point(self, screen, pos, collision):
        if not collision:
            pygame.draw.circle(screen, GREEN, pos, 5)
        else:
            pygame.draw.circle(screen, RED, pos, 5)

    def check_collision(self, rect):
        self.collision[0] = rect.collidepoint(self.rect.topleft)
        self.collision[1] = rect.collidepoint(self.rect.topright)
        self.collision[2] = rect.collidepoint(self.rect.bottomleft)
        self.collision[3] = rect.collidepoint(self.rect.bottomright)

        self.collision[4] = rect.collidepoint(self.rect.midleft)
        self.collision[5] = rect.collidepoint(self.rect.midright)
        self.collision[6] = rect.collidepoint(self.rect.midtop)
        self.collision[7] = rect.collidepoint(self.rect.midbottom)

        self.collision[8] = rect.collidepoint(self.rect.center)

    def render_collision_info(self):

        text = "collision: "
        print "collision:",

        if self.collision[0] or self.collision[2] or self.collision[4]:
            text += "left "
            print "left",

        if self.collision[1] or self.collision[3] or self.collision[5]:
            text += "right "
            print "right",

        if self.collision[0] or self.collision[1] or self.collision[6]:
            text += "top "
            print "top",

        if self.collision[2] or self.collision[3] or self.collision[7]:
            text += "bottom "
            print "bottom",

        if self.collision[8]:
            text += "center "
            print "center",

        print

        self.text = self.font.render(text, 1, WHITE)

    def draw_collision_info(self, screen, pos):
        screen.blit(self.text, pos)

#----------------------------------------------------------------------

class Game():

    def __init__(self):

        pygame.init()

        self.screen = pygame.display.set_mode( (800,600) )
        pygame.display.set_caption("Side Collision")

        self.player = Player()
        self.enemy  = Player()
        self.enemy.set_center(self.screen)


    def run(self):
        clock = pygame.time.Clock()

        RUNNING = True

        while RUNNING:

            # --- events ----

            for event in pygame.event.get():
                if event.type == pygame.QUIT:
                    RUNNING = False

                elif event.type == pygame.KEYDOWN:
                    if event.key == pygame.K_ESCAPE:
                        RUNNING = False

                self.player.event_handler(event)

            # --- updates ---

            self.player.update()
            self.enemy.update()

            self.player.check_collision(self.enemy.rect)
            self.enemy.check_collision(self.player.rect)
            self.player.render_collision_info()
            self.enemy.render_collision_info()

            # --- draws ----

            self.screen.fill(BLACK)

            self.player.draw(self.screen)
            self.enemy.draw(self.screen)

            self.player.draw_collision_info(self.screen, (0,0))
            self.enemy.draw_collision_info(self.screen, (0,32))

            pygame.display.update()

            # --- FPS ---

            clock.tick(30)

        pygame.quit()

#----------------------------------------------------------------------

Game().run()

---

编辑（08.2016）：带有碰撞rect 、 rect_ratio 、 circle

GitHub: furas/python-examples/pygame/collisions

Answer 2

就像 Furas 所说的那样，不，没有办法在 Pygame 中通过他设置的点系统来获得侧面碰撞。 甚至那个也不会给你你想要的东西，因为在处理矩形的行、列或角时，你永远无法确定碰撞发生在哪个方向。

这就是为什么大多数教程建议保存您的精灵初始方向。 然后在发生碰撞时向相反的方向移动。

Answer 3

我通过创建多个碰撞盒解决了这个问题。 这应该可以帮助很多人。

https://youtu.be/W-Vz6le1YUg

代码：

if tanner.axe.colliderect(oak.red) and. 
      tanner.playerHitBox.colliderect(oak.leftHit) and. 
      keys_pressed[pygame.K_SPACE]:
      Number_of_Hits_Left += 1
      print(Number_of_Hits_Left)

 if tanner.axe.colliderect(oak.red) and. 
       tanner.playerHitBox.colliderect(oak.rightHit) and. 
       keys_pressed[pygame.K_SPACE]:
       Number_of_Hits_Right += 1
       print(Number_of_Hits_Right)

所以我总共有 5 个命中盒来完成上述任务。 实际上，您所要做的就是创建主命中框，然后在主命中框的左侧和右侧创建 2 个侧框，以便它们几乎不重叠。 因此，假设您发射子弹，您的代码将类似于上面的内容。 “当子弹与侧框碰撞以及子弹与主框碰撞时，做点什么。”

Answer 4

碰撞背后的逻辑是这样的：

#Assume two surfaces
objectA
objectB

if objectA.right > objectB.left and objectA.left < objectB.right and objectA.top < objectB.bottom and objectA.bottom > objectB.top
    #Collision happens

如果您想检测侧面碰撞（就像 objectA 在侧面击中 objectB），您可以执行以下操作：

#Here is the code where objectA moves
objectA.X += 10
#Here check Collision, if collision happens objectA hitted objectB from the side
objectA.Y += 10
#Here check Collision again, if collision is true then objectA hitted object B from top/bottom

Answer 5

对于 objectA 给对象这个方法：

def is_collided_with(self, sprite): return self.rect.colliderect(sprite.rect)

此 return 语句返回 True 或 False

然后在碰撞的主循环中只做： if objectA.is_collided_with(ObjectB): Collision happened!