python - 在pygame中发生一定数量的碰撞后更改背景

Question

如果检测到一定数量的碰撞(或击中气球)，我将尝试仅切换背景。碰撞发生在枪支和屏幕上的 7 个气球之间。

注意:碰撞效果非常好。

目前，会显示 7 个气球，每次我击中气球时它都会切换背景。应该发生的是，当您在第一个背景上击中 7 个气球中的 1 个时，它会更改为您在显示的 7 个气球中再次击中 1 个气球的第二个背景。当您在第二个背景上点击气球时，它会变回第一个。然后(回到第一个背景)你击中了 2 个气球(共 7 个)，然后它变为第二个背景，你再次击中了 2 个气球，依此类推。 所以命中数应该是 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 7, 7; (总共显示 7 个气球)，其中每对中的第一个数字是第一个背景中的命中数，第二个是新背景中的命中数。

这是改变背景的原因:

for balloon_list_index in num_balloon_list:
    balloon_list_index += 1
    bg_bool = not bg_bool

这是所需命中数的列表:

num_balloon_list = [1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 7, 7]

这是我的完整代码:

import pygame as pg
import random as r
import sys

pg.init()

bg = pg.image.load('bg.jpg')  # Background Image #
bg = pg.transform.scale(bg, (688, 387))
new_bg = pg.image.load('new_bg.jpg')
new_bg = pg.transform.scale(new_bg, (688, 387))

radius = 30
diameter = 2 * radius

num_balloons = 7
bullets_colors_ls = []
iterator = -1

num_balloon_list = [1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 7, 7]
balloon_list_index = 0


def create_balloons():
    global balloon_list
    global colors

    for i in range(num_balloons):
        while True:
            candidate = r.randint(0, 500)
            if all(abs(candidate - x) >= diameter for x in balloon_list):
                break
        balloon_list.append(candidate)


def draw_balloons(y):
    for i in range(num_balloons):
        screen.blit(colors[i], (balloon_list[i], y - 50))


def check_collisions(x, y):
    global hit_var
    global hit
    global score
    global scoretext
    global bg_bool
    global num_balloon_list, balloon_list_index

    for i in range(num_balloons):
        gun_rect = gun.get_rect(topleft=(x, y))
        gun_mask = pg.mask.from_surface(gun)

        balloon_rect = colors[i].get_rect(topleft=(balloon_list[i], y - 100))
        balloon_mask = pg.mask.from_surface(colors[i])

        offset = (balloon_rect.x - gun_rect.x), (balloon_rect.y - gun_rect.y)
        if gun_mask.overlap(balloon_mask, offset):
            hit = True

            for balloon_list_index in num_balloon_list:
                balloon_list_index += 1
                bg_bool = not bg_bool

            hit_var = i
            score += 2
            scoretext = myfont.render("SCORE: " + str(score), 1, (0, 0, 0))
            print(f'hit balloon: {i}')
            break


# Vars #
x = 0
y = 250
velocity = 5
score = 0
hit = False
bg_bool = False
testvar1 = True
clock = pg.time.Clock()

screen = pg.display.set_mode((688, 387))  # Size of the screen #
caption = pg.display.set_caption("Remember")  # Title of the window #

balloon_list = []
b1 = pg.image.load('balloons/1.png').convert_alpha()
b1 = pg.transform.scale(b1, (63, 131))
b2 = pg.image.load('balloons/2.png').convert_alpha()
b2 = pg.transform.scale(b2, (63, 131))
b3 = pg.image.load('balloons/3.png').convert_alpha()
b3 = pg.transform.scale(b3, (63, 131))
b4 = pg.image.load('balloons/4.png').convert_alpha()
b4 = pg.transform.scale(b4, (63, 131))
b5 = pg.image.load('balloons/5.png').convert_alpha()
b5 = pg.transform.scale(b5, (63, 131))
b6 = pg.image.load('balloons/6.png').convert_alpha()
b6 = pg.transform.scale(b6, (63, 131))
b7 = pg.image.load('balloons/7.png').convert_alpha()
b7 = pg.transform.scale(b7, (63, 131))
colors = [b1, b2, b3, b4, b5, b6, b7]

gun = pg.image.load('game-gun.png').convert_alpha()
gun = pg.transform.scale(gun, (150, 150))

create_balloons()

pg.display.flip()  # Updating #

running = True  # Game loop bool #

while running:  # Game loop #
    clock.tick(60)

    if bg_bool == False:
        screen.blit(bg, (0, 0))

    elif bg_bool == True:
        screen.blit(new_bg, (0, 0))
        screen.blit(scoretext, (5, 10))

    if hit == True:
        r.shuffle(balloon_list)
        hit = False

    for event in pg.event.get():
        if event.type == pg.QUIT:
            pg.quit()
            sys.exit()
        if event.type == pg.KEYDOWN:
            if event.key == pg.K_ESCAPE:
                running = False

            if event.key == pg.K_SPACE:
                check_collisions(x, y)

    draw_balloons(y)

    keys = pg.key.get_pressed()
    x += keys[pg.K_RIGHT] - keys[pg.K_LEFT] * velocity
    x -= keys[pg.K_LEFT] - keys[pg.K_RIGHT] * velocity

    screen.blit(gun, (x, y))
    pg.display.update()

您可以在这里下载所有图片:Download images on Replit

balloons/
  1.png
  2.png
  3.png
  4.png
  5.png
  6.png
  7.png
bg.jpg
game-gun.png
new_bg.jpg

如何在一定次数的碰撞(击中气球)后更改背景？

附言I have asked a question that is a similar concept有一个很好的答案，但我没能在这个场景中实现它。

Answer 1

首先，您需要一个全局变量来跟踪点击次数。

num_balloons = 7
num_hits = 0  # Add this

当被击中时，更新气球的数量和被击中的次数。

然后，比较需要的命中次数，如果游戏还没有结束:

• 恢复气球的数量，
• 重置点击次数，
• 增加气球列表索引以获得下一个所需的命中数，并且
• 🎉 改变背景 🎉 .

def check_collisions(x, y):
    # ...
    global num_balloons, num_hits  # Add this

    for i in range(num_balloons):
        # ...
        if gun_mask.overlap(balloon_mask, offset):
            hit = True

            # for balloon_list_index in num_balloon_list:               # Remove this
            num_balloons -= 1                                           # Add this
            num_hits += 1                                               # Add this
            num_hits_needed = num_balloon_list[balloon_list_index]      # Add this
            game_end = balloon_list_index == len(num_balloon_list) - 1  # Add this
            if num_hits == num_hits_needed and not game_end:            # Add this
                num_balloons += num_hits  # Restore balloons            # Add this
                num_hits = 0              # and then reset hits         # Add this
                balloon_list_index += 1
                bg_bool = not bg_bool

            # ...