随机产生敌人

Question

我正在制作一个小的2d游戏，目标是尽可能多地吃粪便，但是我在随机的时间里很难产生粪便。我希望粪便在敌人的y位置产卵，然后像rpg一样向前射击

import pygame
from pygame.locals import *
from numpy.random import rand

pygame.init()
pygame.display.set_caption('STINKY BEETLE')

screen_width = 800
screen_height = 600
game_running = True
pl_x = int(screen_width/10)
pl_y = int(screen_height/2)
pl_width = 80
pl_height = 40
pl_vel = 30
en_width = 80
en_height = 40
en_x = screen_width - screen_width/10 - en_width
en_y = int(screen_height/2)
en_yvel = -10
po_width = 50
po_height = 30
po_x = 720
po_y = en_y
po_xvel = 15

screen = pygame.display.set_mode((screen_width, screen_height))
clock = pygame.time.Clock()

while game_running:
    clock.tick(10)

    po_delay = rand(1)

    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            game_running = False

        if event.type == MOUSEBUTTONDOWN:
            if event.button == 4 and pl_y > pl_vel:
                pl_y -= pl_vel

            elif event.button == 5 and pl_y < screen_height - pl_width:
                pl_y += pl_vel

    if po_delay < 0.01:
        poop(po_x, po_y)

    en_y += en_yvel
    if en_y <= 0 or en_y >= screen_height - en_height:
        en_yvel =- en_yvel

    screen.fill((0, 0, 0))
    pygame.draw.rect(screen, (105, 255, 125), (pl_x, pl_y, pl_width, pl_height))
    pygame.display.update()

    pygame.draw.rect(screen, (255, 125, 115), (en_x, en_y, en_width, en_height))
    pygame.display.update()

pygame.quit()

Answer 1

你可以使用pygame的时间模块随机繁殖敌人。我假设您正在为此使用OOP。首先，当初始化敌人类时，记录它第一次生成的时间

class Enemy:
    def __init__(self):
        self.start = time.time()
        # other code

然后你可以计算出自从你的敌人上次开火以来经过的时间。您可以在主游戏循环中执行类似now = time.time()的操作，并获得差异

enemy = Enemy()
while True:
    now = time.time()
    time_passed = now - enemy.start()

现在，您可以使用此time_passed作为您可能创建的spawn_enemy()函数的参数，该函数可能如下所示：

def spawn(self, t):
   counter = t % random.randint(1, 10)
   if counter >= 0 and counter <=  0.2:
       #spawn enemy

将此函数调用为spawn(time_passed)

Answer 2

如果你想管理多个“便便”，那么你必须创建一个列表。每个“poop”都是一个对象（aclass的实例）

板条箱一个类Poop，它可以update位置和draw船尾：

class Poop:
    def __init__(self, x, y, w, h):
        self.rect = pygame.Rect(x, y-h//2, w, h)
        self.vel = -15
    def update(self):
        self.rect.x += self.vel
    def draw(self, surf):
        pygame.draw.rect(surf, (255, 200, 125), self.rect)

poops = []

使用计时器事件生成粪便。使用^{}重复创建^{}。时间以毫秒为单位设置。通过^{}设置随机时间，例如，将时间设置在0.5到4秒之间（当然，您可以选择自己的时间间隔）：

min_time, max_time = 500, 4000 # 0.5 seconds to to 4 seconds
spawn_event = pygame.USEREVENT + 1
pygame.time.set_timer(spawn_event, random.randint(min_time, max_time))

注意，在pygame中可以定义客户事件。每个事件都需要一个唯一的id。用户事件的id必须从pygame.USEREVENT开始。在本例中pygame.USEREVENT+1是计时器事件的事件id，该事件生成POOP

当事件在事件循环中发生时，创建一个新的poop，并设置一个新的随机时间：

for event in pygame.event.get():
    # [...]
    if event.type == spawn_event:
        pygame.time.set_timer(spawn_event, random.randint(min_time, max_time))
        poops.append(Poop(en_x, en_y+en_yvel+en_height//2, 50, 30))

在循环中更改粪便的位置，如果它们离开左侧的窗口，则将其从列表中删除：

for poop in poops[:]:
    poop.update()
    if poop.rect.right <= 0:
        poops.remove(poop)

把它们画成一个圈

for poop in poops:
    poop.draw(screen)

请参见示例：

import pygame
from pygame.locals import *
import random

pygame.init()
pygame.display.set_caption('STINKY BEETLE')

class Poop:
    def __init__(self, x, y, w, h):
        self.rect = pygame.Rect(x, y-h//2, w, h)
        self.vel = -15
    def update(self):
        self.rect.x += self.vel
    def draw(self, surf):
        pygame.draw.rect(surf, (255, 200, 125), self.rect)

screen_width = 800
screen_height = 600
game_running = True
pl_x, pl_y = screen_width//10, screen_height//2
pl_width, pl_height, pl_vel = 80, 40, 30
en_width, en_height, en_yvel = 80, 40, -10
en_x, en_y,  = screen_width - screen_width//10 - en_width, screen_height//2

screen = pygame.display.set_mode((screen_width, screen_height))
clock = pygame.time.Clock()

min_time, max_time = 500, 4000 # 0.5 seconds up to 4 seconds 
spawn_event = pygame.USEREVENT + 1
pygame.time.set_timer(spawn_event, random.randint(min_time, max_time))
poops = []

while game_running:
    clock.tick(10)

    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            game_running = False

        if event.type == MOUSEBUTTONDOWN:
            if event.button == 4 and pl_y > pl_vel:
                pl_y -= pl_vel
            elif event.button == 5 and pl_y < screen_height - pl_width:
                pl_y += pl_vel

        if event.type == spawn_event:
            pygame.time.set_timer(spawn_event, random.randint(min_time, max_time))
            poops.append(Poop(en_x, en_y+en_yvel+en_height//2, 50, 30))

    en_y += en_yvel
    if en_y <= 0 or en_y >= screen_height - en_height:
        en_yvel =- en_yvel

    for poop in poops[:]:
        poop.update()
        if poop.rect.right <= 0:
            poops.remove(poop)

    screen.fill((0, 0, 0))
    for poop in poops:
        poop.draw(screen)
    pygame.draw.rect(screen, (105, 255, 125), (pl_x, pl_y, pl_width, pl_height))
    pygame.draw.rect(screen, (255, 125, 115), (en_x, en_y, en_width, en_height))
    pygame.display.update()

pygame.quit()