pygame坠落碰撞导致方块一直小范围上下震动

import pygame as pg
import random
from settings import *
from sprites import *

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.running = True

    def new(self):
        self.all_sprites = pg.sprite.Group()
        self.platforms = pg.sprite.Group()
        self.player = Player(self)
        self.all_sprites.add(self.player)
        p1 = Platform(0, HEIGHT-40, WIDTH, 40)
        p2 = Platform(WIDTH/2 - 50, HEIGHT * 3 / 4, 100, 20)
        self.all_sprites.add(p2)
        self.all_sprites.add(p1)
        self.platforms.add(p1)
        self.platforms.add(p2)
        self.run()

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

    def update(self):
        self.all_sprites.update()
        if self.player.vel.y >0:
            hits = pg.sprite.spritecollide(self.player,self.platforms,False)
            if hits:
                self.player.pos.y = hits[0].rect.top
                self.player.vel.y = 0

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

    def draw(self):
        self.screen.fill(BLACK)
        self.all_sprites.draw(self.screen)
        #  double buffering
        pg.display.flip()

    def show_start_screen(self):
        pass

    def show_go_screen(self):
        pass

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

pg.quit()

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.image = pg.Surface((30,40))
        self.image.fill(YELLOW)
        self.rect = self.image.get_rect()
        self.rect.center = (WIDTH/2,HEIGHT/2)
        self.pos = vec(WIDTH/2,HEIGHT/2)
        self.vel = vec(0,0)
        self.acc = vec(0,0)

    def jump(self):
        self.rect.x += 1
        hits = pg.sprite.spritecollide(self,self.game.platforms,False)
        self.rect.x -= 1
        if hits:
            self.vel.y = -20

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

        if self.pos.x >WIDTH:
            self.pos.x = 0
        if self.pos.x < 0:
            self.pos.x = WIDTH

        self.rect.midbottom = self.pos

class Platform(pg.sprite.Sprite):
    def __init__(self,x,y,w,h):
        pg.sprite.Sprite.__init__(self)
        self.image = pg.Surface((w,h))
        self.image.fill(GREEN)
        self.rect = self.image.get_rect()
        self.rect.x = x
        self.rect.y = y

TITLE = "My Game"

WIDTH = 480
HEIGHT = 600
FPS = 60

PLAYER_GRAV = 0.5
PLAYER_ACC = 0.5
PLAYER_FRICTION = -0.12

BLACK = (0,0,0)
WHITE = (255,255,255)
RED = (255,0,0)
GREEN = (0,255,0)
BLUE = (0,0,255)
YELLOW = (255,255,0)

在用空格键跳跃时 很大概率不起作用 发现方块在上下晃 不知道怎么改

这个原因找到了 是在碰撞检测之后 将底部坐标置为地面顶部坐标 

这样的话 他们其实处于一个没有碰撞的状态 依旧会下落 然后检测碰撞

只需要将底部坐标置为地面顶部坐标-1  这样他们就一直处于碰撞中 不会重复执行