python - 如何使用pygame使圆形物体跳跃？

Question

我刚开始使用 pygame ，我被卡住了。
我没有收到任何语法错误，但我确定下面的代码存在一些问题。

import pygame
import sys

pygame.init()
pygame.display.set_caption('Jumper Game')

display_width = 500
display_height = 500
the_game_is_on = True

ball_pos_x = 200
ball_pos_y = 500
ball_radius = 20
ball_color = [0,0,255]
speed = 1

is_jump = False
m = 1
v = 5

dis = pygame.display.set_mode((display_width,display_height)) #screen

while the_game_is_on:
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            sys.exit()
    keys = pygame.key.get_pressed()
    if keys[pygame.K_LEFT] and ball_pos_x > 20:
        ball_pos_x-= speed
    if keys[pygame.K_RIGHT] and ball_pos_x < (display_width - (ball_radius)):
        ball_pos_x+= speed
    if not (is_jump):
        if keys[pygame.K_UP] and ball_pos_y > 20:
            ball_pos_y-= speed
        if keys[pygame.K_DOWN] and ball_pos_y < (display_height - (ball_radius)):
            ball_pos_y+= speed
        if keys[pygame.K_SPACE]:
            is_jump = True
    else:
        f = (1/2)*m*(v**2)
        ball_pos_y-=f
        v-=1
        if v < 0:
            m = -1
        if v >= ((v+1)*-1): #to check the initial position
            is_jump = False
    pygame.time.delay(10)
    dis.fill((0,0,0))
    pygame.draw.circle(dis,ball_color,(ball_pos_x,int(ball_pos_y)),ball_radius)
    pygame.display.update()
pygame.display.quit()

关于跳转代码的编写，我引用了这个 website ，本网站的源代码完美运行。

Answer 1

你必须计算 m依赖于 v < 0 :

m = -1 if v < 0 else 1

如果 v < -5，跳转必须结束当跳转结束时，然后 v必须重置( v = 5 ):

jump_h = 5 # try 10 for higher jumps
v = jump_h

while the_game_is_on:
    # [...]

    if not is_jump:
        # [...]

    else:
        if v >= -jump_h:
            m = -1 if v < 0 else 1
            f = (1/2)*m*(v**2)
            v -=1
            ball_pos_y -= f
        else:
            is_jump = False
            v = jump_h