python - 检查 pygame 中的碰撞和停止速度

Question

我正在尝试在 pygame 中制作一个简单的平台游戏，模拟重力和碰撞。我无法让碰撞发挥作用。与 Sprite 碰撞时，玩家会缓慢地穿过 Sprite 坠落，并在到达 Sprite 后继续以正常速度坠落。

主.py:

class Game:
    def __init__(self):
        # initialize pygame library
        pg.init()
        pg.mixer.init()

        # initialize screen
        self.screen =  pg.display.set_mode((WIDTH, HEIGHT))
        pg.display.set_caption(TITLE)
        self.clock = pg.time.Clock()
        self.font = pg.font.match_font(FONT_NAME)

        self.running = True
        self.playing = True

    def new(self):
        # initzialize sprite groups
        self.sprites = pg.sprite.Group()
        self.objects = pg.sprite.Group()

        self.p = Player(self)
        self.sprites.add(self.p)

        self.g = Ground()
        self.sprites.add(self.g)
        self.objects.add(self.g)

        self.o = Object(100, 350, 100, 20)
        self.sprites.add(self.o)
        self.objects.add(self.o)

        self.collide = False

        self.run()

    # constant running functions
    def run(self):
        while self.playing:
            self.clock.tick(FPS)
            self.events()
            self.update()
            self.draw()
        self.running = False


    def events(self):
        for event in pg.event.get():
            if event.type == pg.QUIT:
                self.playing = False
            if event.type == pg.KEYDOWN:
                if event.key == pg.K_UP:
                    self.p.jump() 

    def update(self):
        self.sprites.update()

        hits = pg.sprite.spritecollide(self.p, self.objects, False)
        if hits:
            self.collide = True
            if self.p.vel.y >= 0.0:
                self.p.x = hits[0].rect.top
                print("Collide bottom")
            elif self.p.vel.y < 0: self.p.top  = hits[0].rect.bottom
            elif self.p.vel.x > 0: self.p.rect.right = hits[0].rect.left
            elif self.p.vel.x < 0: self.p.rect.left = hits[0].rect.right
            self.p.vel.y = 0
            #self.p.acc.y = 0
            #print(f"Collision with {hits[0].name}")
        else:
            self.collide = False



    def draw(self):
        self.screen.fill(BLACK)
        self.sprites.draw(self.screen)

        self.drawtext(f"X Pos: = {int(self.p.pos.x)}", 15, WHITE, WIDTH - 5, 20, 3)
        self.drawtext(f"Y Pos: = {int(self.p.pos.y)}", 15, WHITE, WIDTH - 5, 40, 3)
        self.drawtext(f"Y Velocity = {self.p.vel.y}", 15, WHITE, 5, 50, 0)
        self.drawtext(f"Y Accelleration = {self.p.acc.y}", 15, WHITE, 5, 70, 0)
        self.drawtext(f"Collision: = {self.collide}", 15, WHITE, 5, 200, 0)
        #print(self.p.vel.y)

        pg.display.flip()

    # other functions
    def drawtext(self, text, size, color, x, y, align):
        font = pg.font.Font(self.font, size)
        text_surface = font.render(text, True, color)
        text_rect = text_surface.get_rect()
        if align == 0:
            text_rect.midleft = (x, y)
        elif align == 1:
            text_rect.midtop = (x, y)
        elif align == 2:
            text_rect.midbottom = (x, y)
        elif align == 3:
            text_rect.midright = (x, y)
        else:
            text_rect.center = (x, y)
        self.screen.blit(text_surface, text_rect)

    # def checkCollisionY(self):
    #     hits = pg.sprite.spritecollide(self.p, self.objects, False)
    #     if hits:
    #         self.collide = True
    #         return True
    #     else:
    #         self.collide = False
    #         return False


g = Game()
while g.running:
    g.new()

pg.quit()

Sprites.py:

from settings import *
import pygame as pg

vec = pg.math.Vector2

class Player(pg.sprite.Sprite):
    def __init__(self, game):
        pg.sprite.Sprite.__init__(self)
        self.game = game
        self.width = 30
        self.height = 30
        self.image = pg.Surface((self.width, self.height))
        self.image.fill(YELLOW)
        self.rect = self.image.get_rect()
        self.rect.center = vec(150, 100)

        self.pos = vec(150, 100)
        self.vel = vec(0, 0)
        self.acc = vec(0, 0)

    def update(self):
        self.acc = vec(0, PLAYER_GRAV)

        #input
        keys = pg.key.get_pressed()
        if keys[pg.K_LEFT]:
            self.acc.x = -PLAYER_ACC
        if keys[pg.K_RIGHT]:
            self.acc.x = PLAYER_ACC



        self.acc.x += self.vel.x * PLAYER_FRICTION

        self.vel += self.acc   
        self.pos += self.vel + 0.5 * self.acc
        print(f"{self.vel.y} + 0.5 * {self.acc.y} = {self.vel.y + 0.5 * self.acc.y}")


        self.rect.topleft = self.pos
    def jump(self):
        hits = pg.sprite.spritecollide(self, self.game.objects, False)
        if hits:
            self.vel.y = -20

class Object(pg.sprite.Sprite):
    def __init__(self, x, y, w, h):
        pg.sprite.Sprite.__init__(self)
        self.image = pg.Surface((w, h))
        self.image.fill((255, 0, 144))
        self.name = "Object"
        self.rect = self.image.get_rect()
        self.rect.x = x
        self.rect.y = y



class Ground(pg.sprite.Sprite):
    def __init__(self):
        pg.sprite.Sprite.__init__(self)
        self.name = "Ground"
        self.image = pg.image.load("ground.png")    
        self.rect = self.image.get_rect()
        self.rect.x = -100
        self.rect.y = 550

设置.py:

# game settings
TITLE = "My Game"
WIDTH = 480
HEIGHT = 800
FPS = 60
FONT_NAME = 'impact'

#Player properties
PLAYER_ACC = 0.7
PLAYER_FRICTION = -0.12
PLAYER_GRAV = 0.7


# define colors
WHITE = (255, 255, 255)
BLACK = (0, 0, 0)
RED = (255, 0, 0)
GREEN = (0, 255, 0)
BLUE = (0, 0, 255)

YELLOW = (255, 255, 0)
CYAN = (0, 255, 255)
PURPLE = (255, 0, 255)

这里重要的代码是main.py中的update()和sprites.py中的update()。帮助？

编辑

hits = pg.sprite.spritecollide(self.p, self.objects, False)
        for hit in hits:
            self.collide = True
            if self.p.vel.x > 0.0: 
                self.p.rect.right = hit.rect.left
                self.p.pos.x = self.p.rect.centerx
                self.p.vel.x = 0

            elif self.p.vel.x < 0.0: 
                self.p.rect.left = hit.rect.right
                self.p.pos.x = self.p.rect.centerx

            self.p.vel.x = 0
            self.p.pos.x = self.p.rect.x
        else:
            self.collide = False

        hits = pg.sprite.spritecollide(self.p, self.objects, False)
        for hit in hits:
            self.collide = True
            if self.p.vel.y >= 0.0:
                self.p.rect.bottom = hit.rect.top
                self.p.pos.y = self.p.rect.centery
                self.p.vel.y = 0

            elif self.p.vel.y < 0.0:
                self.p.rect.top = hit.rect.bottom
                self.p.pos.y = self.p.rect.centery
                self.p.vel.y = 0
            self.p.pos.y = self.p.rect.y
        else:
            self.collide = False

Answer 1

您的 Player 类没有 x 和 y 属性，但您需要一个 pos 属性碰撞后发生变化。对象的矩形也需要更新，最好先更新，然后将 pos.y 坐标设置为 rect.centery 坐标。

if self.p.vel.y >= 0.0:
    self.p.rect.bottom = hits[0].rect.top
    self.p.pos.y = self.p.rect.centery
    self.p.vel.y = 0

对其他方向执行相同的操作。

此外，水平和垂直移动应单独处理，否则您会看到奇怪的跳跃，例如从平台的侧面到顶部。看看这个platformer example的第一部分.

<小时/>

在 jump 方法中，您需要将矩形向下移动 1 个像素，以便它能够与平台 Sprite 碰撞。

def jump(self):
    self.rect.y += 1
    # ...

<小时/>

这是一个完整的、可运行的示例:

import pygame as pg


# game settings
TITLE = "My Game"
WIDTH = 480
HEIGHT = 800
FPS = 60
FONT_NAME = 'impact'

#Player properties
PLAYER_ACC = 0.7
PLAYER_FRICTION = -0.12
PLAYER_GRAV = 0.7

# define colors
WHITE = (255, 255, 255)
BLACK = (0, 0, 0)
YELLOW = (255, 255, 0)

vec = pg.math.Vector2


class Player(pg.sprite.Sprite):
    def __init__(self, game):
        pg.sprite.Sprite.__init__(self)
        self.game = game
        self.image = pg.Surface((30, 30))
        self.image.fill(YELLOW)
        self.rect = self.image.get_rect(center=(150, 100))

        self.pos = vec(150, 100)
        self.vel = vec(0, 0)
        self.acc = vec(0, 0)
        self.objects = game.objects

    def update(self):
        self.acc = vec(0, PLAYER_GRAV)

        #input
        keys = pg.key.get_pressed()
        if keys[pg.K_LEFT]:
            self.acc.x = -PLAYER_ACC
        if keys[pg.K_RIGHT]:
            self.acc.x = PLAYER_ACC

        self.acc.x += self.vel.x * PLAYER_FRICTION
        self.vel += self.acc

        # Move along the x-axis first.
        self.pos.x += self.vel.x + 0.5 * self.acc.x
        # print(f"{self.vel.y} + 0.5 * {self.acc.y} = {self.vel.y + 0.5 * self.acc.y}")
        self.rect.centerx = self.pos.x
        # Check if the sprite collides with a platform.
        hits = pg.sprite.spritecollide(self, self.objects, False)
        if hits:
            # Reset the x position.
            if self.vel.x > 0:
                self.rect.right = hits[0].rect.left
                self.pos.x = self.rect.centerx
                self.vel.x = 0
            elif self.vel.x < 0:
                self.rect.left = hits[0].rect.right
                self.pos.x = self.rect.centerx
                self.vel.x = 0

        # Move along the y-axis.
        self.pos.y += self.vel.y + 0.5 * self.acc.y
        self.rect.centery = self.pos.y
        # Check if the sprite collides with a platform.
        hits = pg.sprite.spritecollide(self, self.objects, False)
        if hits:
            # Reset the y position.
            if self.vel.y >= 0.0:
                self.rect.bottom = hits[0].rect.top
                self.pos.y = self.rect.centery
                self.vel.y = 0
            elif self.vel.y < 0:
                self.rect.top = hits[0].rect.bottom
                self.pos.y = self.rect.centery
                self.vel.y = 0

    def jump(self):
        self.rect.y += 1  # Move it down to check if it collides with a platform.
        hits = pg.sprite.spritecollide(self, self.game.objects, False)
        if hits:
            self.vel.y = -20
        self.rect.y -= 1  # Move it up again after the collision check.


class Object(pg.sprite.Sprite):
    def __init__(self, x, y, w, h):
        pg.sprite.Sprite.__init__(self)
        self.image = pg.Surface((w, h))
        self.image.fill((255, 0, 144))
        self.name = "Object"
        self.rect = self.image.get_rect()
        self.rect.x = x
        self.rect.y = y


class Ground(pg.sprite.Sprite):
    def __init__(self):
        pg.sprite.Sprite.__init__(self)
        self.name = "Ground"
        self.image = pg.Surface((500, 300))
        self.image.fill((90, 30, 30))
        self.rect = self.image.get_rect()
        self.rect.x = -100
        self.rect.y = 550


class Game:
    def __init__(self):
        pg.init()
        pg.mixer.init()
        self.screen =  pg.display.set_mode((WIDTH, HEIGHT))
        pg.display.set_caption(TITLE)
        self.clock = pg.time.Clock()
        self.font = pg.font.match_font(FONT_NAME)

        self.running = True
        self.playing = True

    def new(self):
        self.sprites = pg.sprite.Group()
        self.objects = pg.sprite.Group()

        self.p = Player(self)
        self.sprites.add(self.p)

        self.g = Ground()
        self.sprites.add(self.g)
        self.objects.add(self.g)

        rects = [(100, 350, 100, 20), (50, 380, 100, 20),
                 (200, 450, 100, 100)]
        for x, y, w, h in rects:
            obj = Object(x, y, w, h)
            self.sprites.add(obj)
            self.objects.add(obj)

        self.collide = False

        self.run()

    def run(self):
        while self.playing:
            self.clock.tick(FPS)
            self.events()
            self.update()
            self.draw()
        self.running = False

    def events(self):
        for event in pg.event.get():
            if event.type == pg.QUIT:
                self.playing = False
            if event.type == pg.KEYDOWN:
                if event.key == pg.K_UP:
                    self.p.jump()

    def update(self):
        self.sprites.update()

    def draw(self):
        self.screen.fill(BLACK)
        self.sprites.draw(self.screen)
        pg.display.flip()


g = Game()
while g.running:
    g.new()

pg.quit()