如何在 pygame 中进行直线和矩形之间的碰撞检测？

Question

这个程序应该打印“True”，只有当绿色矩形接触到红线时，但每次绿色矩形进入红线“区域”（接触线精灵）时它都会打印 True。有没有办法制作线条精灵？

这段代码中green不在线，但仍然打印true：



class Line(pygame.sprite.Sprite):
    def __init__(self):
        super().__init__()
        self.image = pygame.Surface((200, 200))
        self.rect = self.image.get_rect()
        self.rect.x = 50
        self.rect.y = 0

    def update(self):
        pygame.draw.line(screen, (255, 0, 0), (self.rect.x, self.rect.y), (200, 200))


class Rectt(pygame.sprite.Sprite):
    def __init__(self):
        super().__init__()
        self.image = pygame.Surface((50, 50))
        self.rect = self.image.get_rect()
        self.rect.x = 25
        self.rect.y = 100

    def update(self):
        pygame.draw.rect(screen, (0, 255, 0), self.rect)


pygame.init()
screen = pygame.display.set_mode((300, 300))
screen.fill((0, 0, 0))
running = True
l = Line()
m = Rectt()
while running:
    for event in pygame.event.get():
        if (event.type == pygame.QUIT):
            running = False
    if (pygame.sprite.collide_mask(m, l)):
        print(True)
    else:
        print(False)
    l.update()
    m.update()
    pygame.display.flip()
    screen.fill((0, 0, 0))
pygame.quit()

Answer 1

见Make a line as a sprite with its own collision in Pygame

您需要创建一个图像 (pygame.Surface) in with a per pixel alpha format (pygame.SRCALPHA) or a black color key (pygame.Surface.get_colorkey)。在图像上画线，blit 屏幕上的图像：

class Line(pygame.sprite.Sprite):
    def __init__(self):
        super().__init__()
        self.image = pygame.Surface((200, 200))
        self.image.set_colorkey((0, 0, 0))
        pygame.draw.line(self.image, (255, 0, 0), (0, 0), (200, 200))
        self.rect = self.image.get_rect()
        self.rect.x = 50
        self.rect.y = 0

    def update(self):
        screen.blit(self.image, self.rect)

对矩形做同样的事情：

class Rectt(pygame.sprite.Sprite):
    def __init__(self):
        super().__init__()
        self.image = pygame.Surface((50, 50))
        self.image.set_colorkey((0, 0, 0))
        pygame.draw.rect(self.image, (0, 255, 0), (0, 0, 50, 50))
        self.rect = self.image.get_rect()
        self.rect.x = 25
        self.rect.y = 100

    def update(self):
        screen.blit(self.image, self.rect)

如果您使用 pygame.sprite.Group and pygame.sprite.Group.draw:

，则根本不需要 update 方法

import pygame

class Line(pygame.sprite.Sprite):
    def __init__(self):
        super().__init__()
        self.image = pygame.Surface((200, 200))
        self.image.set_colorkey((0, 0, 0))
        pygame.draw.line(self.image, (255, 255, 0), (0, 0), (200, 200), 5)
        self.rect = self.image.get_rect(topleft = (50, 50))

class Rectt(pygame.sprite.Sprite):
    def __init__(self):
        super().__init__()
        self.image = pygame.Surface((50, 50))
        self.image.set_colorkey((0, 0, 0))
        pygame.draw.rect(self.image, (0, 0, 255), (0, 0, 50, 50))
        self.rect = self.image.get_rect(topleft = (25, 100))

pygame.init()
screen = pygame.display.set_mode((300, 300))
clock = pygame.time.Clock()

running = True
l = Line()
m = Rectt()
group = pygame.sprite.Group([l, m])

while running:
    clock.tick(100)
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            running = False

    keys = pygame.key.get_pressed()
    m.rect.x += (keys[pygame.K_RIGHT] - keys[pygame.K_LEFT]) * 3
    m.rect.y += (keys[pygame.K_DOWN] - keys[pygame.K_UP]) * 3
    m.rect.clamp_ip(screen.get_rect())
    hit = pygame.sprite.collide_mask(m, l)
   
    screen.fill((0, 0, 0))
    group.draw(screen)
    if hit:
        pygame.draw.rect(screen, (255, 0, 0), m.rect, 5)
    pygame.display.flip()
   
pygame.quit()

如何在 pygame 中进行直线和矩形之间的碰撞检测？

How to do a collision detection between line and rectangle in pygame?

python

pygame