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