51 lines
1.6 KiB
Python
51 lines
1.6 KiB
Python
import pygame
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import random
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from asteroid import Asteroid
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from constants import *
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class AsteroidField(pygame.sprite.Sprite):
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edges = [
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[
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pygame.Vector2(1, 0),
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lambda y: pygame.Vector2(-ASTEROID_MAX_RADIUS, y * SCREEN_HEIGHT),
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],
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[
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pygame.Vector2(-1, 0),
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lambda y: pygame.Vector2(
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SCREEN_WIDTH + ASTEROID_MAX_RADIUS, y * SCREEN_HEIGHT
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),
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],
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[
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pygame.Vector2(0, 1),
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lambda x: pygame.Vector2(x * SCREEN_WIDTH, -ASTEROID_MAX_RADIUS),
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],
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[
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pygame.Vector2(0, -1),
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lambda x: pygame.Vector2(
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x * SCREEN_WIDTH, SCREEN_HEIGHT + ASTEROID_MAX_RADIUS
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),
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],
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]
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def __init__(self):
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pygame.sprite.Sprite.__init__(self, self.containers)
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self.spawn_timer = 0.0
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def spawn(self, radius, position, velocity):
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asteroid = Asteroid(position.x, position.y, radius)
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asteroid.velocity = velocity
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def update(self, dt):
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self.spawn_timer += dt
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if self.spawn_timer > ASTEROID_SPAWN_RATE:
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self.spawn_timer = 0
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# spawn a new asteroid at a random edge
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edge = random.choice(self.edges)
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speed = random.randint(40, 100)
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velocity = edge[0] * speed
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velocity = velocity.rotate(random.randint(-30, 30))
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position = edge[1](random.uniform(0, 1))
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kind = random.randint(1, ASTEROID_KINDS)
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self.spawn(ASTEROID_MIN_RADIUS * kind, position, velocity)
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