Pygame：精灵侧面碰撞

问题描述：

pygame 中是否有办法查找精灵的特定侧面与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 的底部发生碰撞，则返回 True。

我确信有办法做到这一点，但我在文档中找不到任何特定的方法。

解决方案 1：

PyGame 中没有获取侧面碰撞的函数。

但是您可以尝试使用pygame.Rect.collidepoint来测试A.rect.midleft，A.rect.midright，A.rect.midtop，A.rect.midbottom，A.rect.topleft，A.rect.bottomleft，是否在（pygame.Rect）内。A.rect.topright`A.rect.bottomright`B.rect

编辑：

示例代码。使用箭头移动玩家并触碰敌人。

（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（2016 年 8 月）：有冲突的版本rect，，rect_ratio`circle`

GitHub：furas/python-examples/pygame/collisions

解决方案 2：

我通过创建多个碰撞盒解决了这个问题。这应该能帮助很多人。

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)

因此，我总共有 5 个命中框来完成上述任务。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，使它们几乎不重叠。假设您射出一颗子弹，您的代码将类似于上面的内容。“当子弹与侧框碰撞并且当子弹与主框碰撞时，执行某些操作。”

解决方案 3：

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（好像物体 A 从侧面撞击物体 B），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

解决方案 4：

就像 Furas 所说的那样，不，在 Pygame 中没有办法通过他设置的点系统来实现侧面碰撞。而且即使那样也无法满足您的要求，因为在处理矩形的行、列或角时，您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精灵的初始方向，然后在发生碰撞时朝相反的方向移动。

解决方案 5：

对于 objectA，给出对象此方法：

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

此返回语句返回 True 或 False

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