pygame having trouble spawning enemies

Question

I'm trying to create a simple game where u have to dodge enemies(asteroids), with pygame, but now I'm having trouble spawning them and I don't know if i should use lists or other things, or the enemy class(asteroidClass) is enough. The interval between spawning them is pretty simple I just don't how to deal with the spawn part (dealing with this for 3 days).

import pygame
import random

pygame.init()
#images 
background = pygame.image.load('#path')
asteroid = pygame.image.load('#path')

display = pygame.display.set_mode((300,500))
FPS = 50

display.blit(background,(0,0))
#player everything is fine

#asteroid
class asteroidClass:
    def __init__(self,asteroidX,asteroidY,asteroidVel):
        self.x = asteroidX
        self.y = asteroidY
        self.vel = asteroidVel
    def asteroid_advancing(self):
        self.y += self.vel
        display.blit(asteroid, (self.x, self.y))

def update():
    pygame.display.update()
    pygame.time.Clock().tick(FPS)

#variables
asteroidX = random.randint(0,250)
asteroidY, asteroidVel = 0, 2
asteroidOutClass = asteroidClass(asteroidX,asteroidY,asteroidVel)



#main loop
run = True
while run:
    #should spawn multiple I don't know with what logic
    #spawning in the same x
    #saw in web they're using lists, maybe i should too?
    #when i print i it just do 0123456 like it should, then restart to 0123456, is it wrong? kinda 100%
    for i in range(7):
        asteroidOutClass.asteroid_advancing() #everytime it's called should spawn and asteroid in random x?

    update()
    display.blit(background, (0, 0))

[This](https://stackoverflow.com/questions/37800894/what-is-the-surface-blit-function-in-pygame-what-does-it-do-how-does-it-work) question may help you — ignacio, Aug 01 '20 at 23:33

score 0 · Answer 1 · answered Aug 02 '20 at 04:13

A few things:

Create the asteroids before the main loop
Use the init method to randomly set asteroid position and speed
Be sure to call an event method in the main loop to prevent freezing

Here's the updated code. I removed the background calls and used a circle for the asteroid.

import pygame
import random

pygame.init()
#images pygame.load() not in here

display = pygame.display.set_mode((300,500))
FPS = 50

#display.blit(background,(0,0))
#player everything is fine

#asteroid
class asteroidClass:
    def __init__(self):
        self.x = random.randrange(0, 300)
        self.y = 0 # always top
        self.velx = random.randrange(1,15)/3
        self.vely = random.randrange(1,15)/3
    def asteroid_advancing(self):
        self.y += self.vely
        self.x += self.velx
        # wrap around screen
        if self.x < 0: self.x=300
        if self.x > 300: self.x=0
        if self.y < 0: self.y=500
        if self.y > 500: self.y=0
        pygame.draw.circle(display, (200, 0, 0), (int(self.x), int(self.y)), 20) # draw asteroid

def update():
    pygame.display.update()
    pygame.time.Clock().tick(FPS)

#variables
# create list of 5 asteroids
roidlist = [asteroidClass() for x in range(7)]

#main loop
run = True
while run:
    for event in pygame.event.get(): # required for OS events
      if event.type == pygame.QUIT:
         pygame.quit()
    display.fill((0,0,0))
    #should spawn multiple I don't know with what logic
    #spawning in the same x
    #saw in web they're using lists, maybe i should too?
    #when i print i it just do 0123456 like it should, then restart to 0123456, is it wrong? kinda 100%
    for r in roidlist:
        r.asteroid_advancing() #everytime it's called should spawn and asteroid in random x?

    update()
#    display.blit(background, (0, 0))

pygame having trouble spawning enemies

1 Answers1