pygame 使用 deltatime 时发生碰撞

Question

我正在尝试了解如何在 pygame 中使用 deltatime，尤其是在涉及碰撞时。我基本上用一些方块制作了一个围绕 window 弹跳的正方形。

这里是不使用 dt 的版本，运行良好：

import pygame,sys

class Block(pygame.sprite.Sprite):
    def __init__(self,pos,size,groups):
        super().__init__(groups)
        self.image = pygame.Surface(size)
        self.image.fill('yellow')
        self.rect = self.image.get_rect(topleft = pos)

class Ball(pygame.sprite.Sprite):
    def __init__(self,groups,obstacles):
        super().__init__(groups)
        self.image = pygame.Surface((40,40))
        self.image.fill('red')
        self.rect = self.image.get_rect(center = (400,400))

        # attributes for dt influenced movement
        self.direction = pygame.math.Vector2((0.8,1))
        self.speed = 6
        self.obstacles = obstacles

    def vertical_collision(self):
        for sprite in self.obstacles.sprites():
            if sprite.rect.colliderect(self.rect):
                if self.direction.y < 0: # moving up 
                    self.rect.top = sprite.rect.bottom
                else: # moving down
                    self.rect.bottom = sprite.rect.top
                self.direction.y *= -1

    def horizontal_collision(self):
        for sprite in self.obstacles.sprites():
            if sprite.rect.colliderect(self.rect):
                if self.direction.x < 0: # left
                    self.rect.left = sprite.rect.right
                else: # right 
                    self.rect.right = sprite.rect.left 
                self.direction.x *= -1

    def wall_constraint(self):
        if self.rect.right >= 800 or self.rect.left <= 0:
            self.direction.x *= -1
        if self.rect.bottom >= 800 or self.rect.top <= 0:
            self.direction.y *= -1

    def update(self):
        self.wall_constraint()

        self.rect.y += self.direction.y * self.speed
        self.vertical_collision()   
        self.rect.x += self.direction.x * self.speed
        self.horizontal_collision()


# setup
pygame.init()
screen = pygame.display.set_mode((800,800))
clock = pygame.time.Clock()

# sprite groups
all_sprites = pygame.sprite.Group()
collision_sprites = pygame.sprite.Group()

# sprite creation
Block((100,400),(60,200),[all_sprites,collision_sprites])
Block((700,600),(100,200),[all_sprites,collision_sprites])
Block((400,200),(200,100),[all_sprites,collision_sprites])
Block((600,300),(10,200),[all_sprites,collision_sprites])
Block((100,200),(100,100),[all_sprites,collision_sprites])
ball = Ball(all_sprites,collision_sprites)

while True:
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            pygame.quit()
            sys.exit()

    screen.fill('black')
    all_sprites.update()
    all_sprites.draw(screen)

    pygame.display.update()
    clock.tick(60)

我遇到的问题是如何将其转换为适用于 deltatime 的格式，这是我目前所拥有的：

import pygame,sys,time

class Block(pygame.sprite.Sprite):
    def __init__(self,pos,size,groups):
        super().__init__(groups)
        self.image = pygame.Surface(size)
        self.image.fill('yellow')
        self.rect = self.image.get_rect(topleft = pos)

class Ball(pygame.sprite.Sprite):
    def __init__(self,groups,obstacles):
        super().__init__(groups)
        self.image = pygame.Surface((40,40))
        self.image.fill('red')
        self.rect = self.image.get_rect(center = (400,400))

        # attributes for dt influenced movement
        self.pos = pygame.math.Vector2(self.rect.topleft)
        self.direction = pygame.math.Vector2((0.8,1))
        self.speed = 200
        self.obstacles = obstacles

    def vertical_collision(self):
        for sprite in self.obstacles.sprites():
            if sprite.rect.colliderect(self.rect):
                if self.direction.y < 0: # moving up 
                    self.pos.y = sprite.rect.bottom + 0.1
                else: # moving down
                    self.pos.y = sprite.rect.top + self.rect.height - 0.1
                self.rect.y = self.pos.y
                self.direction.y *= -1

    def horizontal_collision(self):
        for sprite in self.obstacles.sprites():
            if sprite.rect.colliderect(self.rect):
                if self.direction.x < 0: # left
                    self.pos.x = sprite.rect.right + 0.1
                else: # right 
                    self.pos.x = sprite.rect.left - self.rect.width - 0.1
                self.rect.x = self.pos.x
                self.direction.x *= -1

    def wall_constraint(self):
        if self.rect.right >= 800 or self.rect.left <= 0:
            self.direction.x *= -1
        if self.rect.bottom >= 800 or self.rect.top <= 0:
            self.direction.y *= -1

    def update(self,dt):
        self.wall_constraint()

        self.pos.y += self.direction.y * self.speed * dt
        self.vertical_collision()   
        self.pos.x += self.direction.x * self.speed * dt
        self.horizontal_collision()

        self.rect.x = round(self.pos.x)
        self.rect.y = round(self.pos.y)


# setup
pygame.init()
screen = pygame.display.set_mode((800,800))
clock = pygame.time.Clock()

# sprite groups
all_sprites = pygame.sprite.Group()
collision_sprites = pygame.sprite.Group()

# sprite creation
Block((100,400),(60,200),[all_sprites,collision_sprites])
Block((700,600),(100,200),[all_sprites,collision_sprites])
Block((400,200),(200,100),[all_sprites,collision_sprites])
Block((600,300),(10,200),[all_sprites,collision_sprites])
Block((100,200),(100,100),[all_sprites,collision_sprites])
ball = Ball(all_sprites,collision_sprites)

last_time = time.time()
while True:
    
    # delta time
    dt = time.time() - last_time
    last_time = time.time()
    
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            pygame.quit()
            sys.exit()

    screen.fill('black')
    all_sprites.update(dt)
    all_sprites.draw(screen)

    pygame.display.update()
    clock.tick(120)

我将球的位置存储在 pos 属性内（作为向量），在更新循环结束时，我将精灵的 rect 位置设置为该 pos 向量的 x 和 y 位置.这是为了考虑 pygame 将矩形放在整数上。

垂直碰撞似乎有效，但水平碰撞确实无效。我怀疑它与 pos 属性的位置和由此产生的碰撞有关，我试图在它碰撞后给它一个偏移量（因此 + 0.1 或 - 0.1）但这似乎没有什么区别。

Answer 1

万一有人在寻找答案，我的问题是更新方法。它应该看起来像这样：

def update(self,dt):
    self.wall_constraint()
    
    # vertical movement + collision
    self.pos.y += self.direction.y * self.speed * dt
    self.rect.y = round(self.pos.y)
    self.vertical_collision()   
    
    # horizontal movement + collision
    self.pos.x += self.direction.x * self.speed * dt
    self.rect.x = round(self.pos.x)
    self.horizontal_collision()

pygame 使用 deltatime 时发生碰撞

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