在pygame中实现非常基本的重力

import pygame
import sys

pygame.init()
width, height = 800, 600
screen = pygame.display.set_mode((width, height))

class Object:
    def __init__(self, x, y):
        self.x = x
        self.y = y
        self.velocity = 0
        self.gravity = 0.1

    def update(self):
        self.velocity += self.gravity
        self.y += self.velocity

object = Object(100, 100)

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

    object.update()

    screen.fill((0, 0, 0))
    pygame.draw.circle(screen, (255, 255, 255), (object.x, int(object.y)), 20)
    pygame.display.flip()