explosions.py

import pygame
import random
from settings import *
from sprites import *

# init explosion animation
explosion_anim = {}
explosion_anim['lg'] = []
explosion_anim['sm'] = []
explosion_anim['laser'] = []
explosion_anim['stars'] = []

for i in range(10):
    filename = 'stars{}.png'.format(i + 1)
    img = pygame.image.load(path.join(img_dir, filename)).convert()
    img.set_colorkey(BLACK)
    img_lg = pygame.transform.scale(img, (100, 20))
    explosion_anim['stars'].append(img_lg)

for i in range(8):
    filename = 'explosion{}.png'.format(i + 1)
    img = pygame.image.load(path.join(img_dir, filename)).convert()
    img.set_colorkey(BLACK)
    img_lg = pygame.transform.scale(img, (75, 75))
    explosion_anim['lg'].append(img_lg)
    img_sm = pygame.transform.scale(img, (32, 32))
    explosion_anim['sm'].append(img_sm)

for i in range(9):
    filename = 'laser_explosion{}.png'.format(i + 1)
    img = pygame.image.load(path.join(img_dir, filename)).convert()
    img.set_colorkey(BLACK)
    img_lg = pygame.transform.scale(img, (75, 75))
    explosion_anim['laser'].append(img_lg)

class Explosion(pygame.sprite.Sprite):
    def __init__(self, center, size):
        pygame.sprite.Sprite.__init__(self)
        self.size = size
        self.image = explosion_anim[self.size][0]
        self.rect = self.image.get_rect()
        self.rect.center = center
        self.frame = 0
        self.last_update = pygame.time.get_ticks()
        self.frame_rate = 50

    def update(self):
        now = pygame.time.get_ticks()
        if now - self.last_update > self.frame_rate:
            self.last_update = now
            self.frame += 1
            if self.frame == len(explosion_anim[self.size]):
                self.kill()
            else:
                center = self.rect.center
                self.image = explosion_anim[self.size][self.frame]
                self.rect = self.image.get_rect()
                self.rect.center = center

class StarExplosion(Explosion):
    def __init__(self, center):
        super().__init__(center, 'stars')
        self.frame_rate = 90
        self.rating = random.randint(5, 10)
    
    def update(self):
        now = pygame.time.get_ticks()
        if now - self.last_update > self.frame_rate:
            self.last_update = now
            self.frame += 1
            if self.frame == self.rating:
                self.kill()
            else:
                center = self.rect.center
                self.image = explosion_anim[self.size][self.frame]
                self.rect = self.image.get_rect()
                self.rect.center = center