为什么我的碰撞测试总是返回“true"，为什么图像矩形的位置总是错误的 (0, 0)? [英] Why is my collision test always returning 'true' and why is the position of the rectangle of the image always wrong (0, 0)?

问题描述

我的collide_rect 功能工作不正常.当它不应该返回时，它总是返回 True.我试过在互联网上寻找，但没有任何效果对我有用.我认为碰撞矩形不知何故没有使用两个精灵的实际坐标.有人可以帮忙吗?

My collide_rect function isn't working properly. It always returns True, when it's not suppose to. I have tried looking on the internet but nothing is working for me. I think the collide rect somehow did not use the actual coordinates for the two sprites. Can anyone help with this?

import pygame
import pygame.sprite
import sys


gameDisplay = pygame.display.set_mode((800,600))
pygame.display.set_caption("test_collision")
clock = pygame.time.Clock()
crashed = False


class Ball(pygame.sprite.Sprite):
    def __init__(self):
        pygame.sprite.Sprite.__init__(self)
        self.image = pygame.image.load("ball.png")
        self.rect = self.image.get_rect()
        self.x = 280
        self.y = 475
        self.col = False
    def update(self):
        gameDisplay.blit(self.image, (self.x,self.y))
        self.rect = self.image.get_rect()
    def test_collisions(self,sprite):
        self.col = pygame.sprite.collide_rect(self,sprite)
class Obstacle(pygame.sprite.Sprite):
    def __init__(self):
        pygame.sprite.Sprite.__init__(self)
        self.x = 1000
        self.y = 483
        self.image = pygame.image.load("obstacle.png")
        self.time = pygame.time.get_ticks()
        self.rect = self.image.get_rect()
    def change_x(self):
        self.time = pygame.time.get_ticks()
        self.x = -(self.time/5) + 800
    def update(self):
        self.rect = self.image.get_rect()
        gameDisplay.blit(self.image,(self.x,self.y))


obstacle = Obstacle()
ball = Ball()      
while not crashed:
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            crashed = True
    gameDisplay.fill((255,255,255))
    ball.update()
    obstacle.change_x()
    obstacle.update()
    ball.test_collisions(obstacle)
    if ball.col:
        print("colided")
    pygame.display.flip()
    clock.tick(1000)


pygame.quit()
sys.exit()

P.S 这是我的第一篇文章:)

P.S This is my first post :)

推荐答案

pygame.Surface.get_rect.get_rect() 返回一个与 Surface 对象大小相同的矩形，但它返回的矩形总是从(0, 0) 因为 Surface 对象没有位置.
Surface 使用 blit 功能放置在显示器上的某个位置.

pygame.Surface.get_rect.get_rect() returns a rectangle with the size of the Surface object, but it returns a rectangle that always starts at (0, 0) since a Surface object has no position.
The Surface is placed at a position on the display with the blit function.

您必须通过关键字参数设置矩形的位置，例如:

You've to set the location of the rectangle, either by a keyword argument, e.g:

self.rect = self.image.get_rect(topleft = (self.x, self.y))

或对虚拟属性的赋值(参见pygame.Rect)，例如:

or an assignment to a virtual attribute (see pygame.Rect), e.g:

self.rect = self.image.get_rect()
self.rect.topleft = (self.x, self.y)

---

完全没有必要添加一些额外的属性self.x 和self.y.改用矩形的位置.例如:

---

It is absolutely unnecessary to add some extra attributes self.x and self.y. Use the location of the rectangle instead. e.g:

class Ball(pygame.sprite.Sprite):
    def __init__(self):
        pygame.sprite.Sprite.__init__(self)
        self.image = pygame.image.load("ball.png")
        self.rect = self.image.get_rect(topleft = (280, 475))
        self.col = False
    def update(self):
        gameDisplay.blit(self.image, self.rect)
    def test_collisions(self,sprite):
        self.col = pygame.sprite.collide_rect(self,sprite)

class Obstacle(pygame.sprite.Sprite):
    def __init__(self):
        pygame.sprite.Sprite.__init__(self)
        self.image = pygame.image.load("obstacle.png")
        self.time = pygame.time.get_ticks()
        self.rect = self.image.get_rect(topleft = (1000, 483))
    def change_x(self):
        self.time = pygame.time.get_ticks()
        self.rect.x = -(self.time/5) + 800
    def update(self):
        gameDisplay.blit(self.image, self.rect)

---

另外注意，你可以分别去掉Ball.update()方法Obstacle.update()(你可以删除它们)，如果你使用apygame.sprite.Group 并调用 .draw()，它使用包含的精灵的 .image 和 .rect 属性来绘制它们.例如:

---

Further note, that you can get rid of the methods Ball.update() respectively Obstacle.update() (you can delete them), if you use a pygame.sprite.Group and call .draw(), which uses the .image and .rect properties of the contained sprites, to draw them. e.g.:

obstacle = Obstacle()
ball = Ball()      
all_sprites = pygame.sprite.Group([obstacle, ball])

while not crashed:

    # [...]
  
    gameDisplay.fill((255,255,255))
    
    all_sprites.draw(gameDisplay)
    
    pygame.display.flip()
    clock.tick(1000)

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