pygame中的精灵蒙版碰撞问题

Question

我正在尝试在 pygame 中创建一个赛车游戏。我想要这样当汽车离开赛道时，它会减速。我试图通过使用另一个作为轨道轮廓的精灵来做到这一点，当汽车接触到该精灵时，它会减速。这不起作用，我不知道为什么。有没有更好的方法来做到这一点？

Img是汽车图片

Back 是赛道

BackHit是大纲

我收到此错误代码：

Traceback（最近一次调用最后一次）： 文件“C:\Users\Daniella\Desktop\Python\Games\game.py”，第 75 行，在 如果 pygame.sprite.collide_mask(Img, BackHit): 文件“C:\Users\Daniella\AppData\Roaming\Python\Python36\site-packages\pygame\sprite.py”，第 1470 行，位于 collide_mask xoffset = right.rect[0] - left.rect[0] AttributeError: 'pygame.Surface' 对象没有属性 'rect'

这是代码：

import pygame

Width = 800
Height = 600

Black = (0, 0, 0)
White = (255, 255, 255)
Red = (255, 0, 0)
Green = (0, 255, 0)
Blue = (0, 0, 255)
Yellow = (255, 255, 0)
BackColour = (198, 151, 107)

pygame.init()
GameDisplay = pygame.display.set_mode((Width, Height))
pygame.display.set_caption("A bit Racey")
Clock = pygame.time.Clock()

Img = pygame.image.load("download.png")
ImgWidth = 46
ImgHeight = 68
Img = pygame.transform.scale(Img, (ImgWidth, ImgHeight))

Back = pygame.image.load("back1.png")
BackWidth = Width*4
BackHeight = Height*4
Back = pygame.transform.scale(Back, (BackWidth, BackHeight))

BackHit = pygame.image.load("back1 hit1.png")
BackHitWidth = Width*4
BackHitHeight = Height*4
BackHit = pygame.transform.scale(BackHit, (BackHitWidth, BackHitHeight))

def Car():
    GameDisplay.blit(Img, (400-ImgWidth/2, 300-ImgHeight/2))

def Background(X, Y):
    GameDisplay.blit(Back, (X, Y))

def BackgroundHit(X, Y):
    GameDisplay.blit(BackHit, (X, Y))

X = (Width*0.45)
Y = (Height*0.5)

XChange = 0
YChange = 0

Changer = 1

Crashed = False

while not Crashed:
    for Event in pygame.event.get():
        if Event.type == pygame.QUIT:
            Crashed = True
        elif Event.type == pygame.KEYDOWN:
            if Event.key == pygame.K_LEFT:
                Img = pygame.transform.rotate(Img, -90)
                XChange = 5 / Changer
            elif Event.key == pygame.K_RIGHT:
                Img = pygame.transform.rotate(Img, 90)
                XChange = -5 / Changer
            elif Event.key == pygame.K_UP:
                Img = pygame.transform.rotate(Img, 0)
                YChange = 5 / Changer
            elif Event.key == pygame.K_DOWN:
                Img = pygame.transform.rotate(Img, 180)
                YChange = -5 / Changer
        if Event.type == pygame.KEYUP:
            if Event.key == pygame.K_LEFT or Event.key == pygame.K_RIGHT:
                XChange = 0
            elif Event.key == pygame.K_UP or Event.key == pygame.K_DOWN:
                YChange = 0
    if pygame.sprite.collide_mask(Img, BackHit):
        Changer = 2
    Y += YChange
    X += XChange
    GameDisplay.fill(White)
    BackgroundHit(X, Y)
    Background(X, Y)
    Car()
    pygame.display.update()
    Clock.tick(200)

pygame.quit()
quit()

Answer 1

这里有一个小例子，向您展示如何使用pygame.mask.from_surface 和pygame.Mask.overlap 进行像素完美碰撞检测。

import pygame as pg

# Transparent surfaces with a circle and a triangle.
circle_surface = pg.Surface((60, 60), pg.SRCALPHA)
pg.draw.circle(circle_surface, (30, 90, 200), (30, 30), 30)
triangle_surface = pg.Surface((60, 60), pg.SRCALPHA)
pg.draw.polygon(triangle_surface, (160, 250, 0), ((30, 0), (60, 60), (0, 60)))


def main():
    screen = pg.display.set_mode((640, 480))
    clock = pg.time.Clock()

    # Use `pygame.mask.from_surface` to get the masks.
    circle_mask = pg.mask.from_surface(circle_surface)
    triangle_mask = pg.mask.from_surface(triangle_surface)

    # Also create rects for the two images/surfaces.
    circle_rect = circle_surface.get_rect(center=(320, 240))
    triangle_rect = triangle_surface.get_rect(center=(0, 0))

    done = False

    while not done:
        for event in pg.event.get():
            if event.type == pg.QUIT:
                done = True
            elif event.type == pg.MOUSEMOTION:
                triangle_rect.center = event.pos

        # Now calculate the offset between the rects.
        offset_x = triangle_rect.x - circle_rect.x
        offset_y = triangle_rect.y - circle_rect.y

        # And pass the offset to the `overlap` method of the mask.
        overlap = circle_mask.overlap(triangle_mask, (offset_x, offset_y))
        if overlap:
            print('The two masks overlap!', overlap)

        screen.fill((30, 30, 30))
        screen.blit(circle_surface, circle_rect)
        screen.blit(triangle_surface, triangle_rect)

        pg.display.flip()
        clock.tick(30)


if __name__ == '__main__':
    pg.init()
    main()
    pg.quit()

---

要为背景或轨道创建蒙版，您需要创建一个额外的图像并让轨道保持透明或汽车应该减速的区域，然后检查汽车是否与轨道或外部区域发生碰撞。在这里，我检查绿色三角形是否与“轨道”（蓝线）相撞，然后在您的游戏中，如果它不与轨道相撞，您将减速汽车。

import pygame as pg


bg_surface = pg.Surface((640, 480), pg.SRCALPHA)
pg.draw.lines(
    bg_surface, (30, 90, 200), True,
    ((60, 130), (300, 50), (600, 200), (400, 400), (150, 300)),
    12)
triangle_surface = pg.Surface((60, 60), pg.SRCALPHA)
pg.draw.polygon(triangle_surface, (160, 250, 0), ((30, 0), (60, 60), (0, 60)))


def main():
    screen = pg.display.set_mode((640, 480))
    clock = pg.time.Clock()

    bg_mask = pg.mask.from_surface(bg_surface)
    triangle_mask = pg.mask.from_surface(triangle_surface)

    bg_rect = bg_surface.get_rect(center=(320, 240))
    triangle_rect = triangle_surface.get_rect(center=(0, 0))

    done = False

    while not done:
        for event in pg.event.get():
            if event.type == pg.QUIT:
                done = True
            elif event.type == pg.MOUSEMOTION:
                triangle_rect.center = event.pos

        offset_x = triangle_rect.x - bg_rect.x
        offset_y = triangle_rect.y - bg_rect.y

        overlap = bg_mask.overlap(triangle_mask, (offset_x, offset_y))
        if overlap:
            print('The two masks overlap!', overlap)

        screen.fill((30, 30, 30))
        screen.blit(bg_surface, bg_rect)
        screen.blit(triangle_surface, triangle_rect)

        pg.display.flip()
        clock.tick(30)


if __name__ == '__main__':
    pg.init()
    main()
    pg.quit()