Adding asteroids/fields and collision

asteroid.py

@@ -0,0 +1,11 @@
+import pygame
+from circleshape import CircleShape 
+class Asteroid(CircleShape):
+    def __init__(self, x, y, radius):
+        super().__init__(x, y, radius)
+    
+    def draw(self, screen):
+        pygame.draw.circle(screen, "white", self.position, self.radius, 2)
+
+    def update(self, dt):
+        self.position += (self.velocity * dt)

asteroidfield.py

@@ -0,0 +1,51 @@
+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)

circleshape.py

@@ -13,6 +13,11 @@ class CircleShape(pygame.sprite.Sprite):
         self.velocity = pygame.Vector2(0, 0)
         self.radius = radius
 
+    def collision(self, other):
+        if self.position.distance_to(other.position) <= (self.radius + other.radius):
+            return True
+        return False
+
     def draw(self, screen):
         # sub-classes must override
         pass

main.py

@@ -4,17 +4,26 @@
 import pygame
 from constants import SCREEN_HEIGHT, SCREEN_WIDTH
 from player import Player
+from asteroid import Asteroid
+from asteroidfield import AsteroidField
 
 def main():
     pygame.init()
     clock = pygame.time.Clock()
     dt = 0
     screen = pygame.display.set_mode((SCREEN_WIDTH, SCREEN_HEIGHT))
+
+    asteroids = pygame.sprite.Group()
+    updatable = pygame.sprite.Group()
+    drawable = pygame.sprite.Group()
+
+    Asteroid.containers = (asteroids, updatable, drawable)
+    AsteroidField.containers = updatable
+    asteroid_field = AsteroidField()
+
+    Player.containers = (updatable, drawable)
+
     player = Player(SCREEN_WIDTH / 2, SCREEN_HEIGHT / 2)
-    updatable = []
-    drawable = []
-    updatable.append(player)
-    drawable.append(player)
 
     while True:
         for event in pygame.event.get():
@@ -30,6 +39,11 @@ def main():
         for object in updatable:
             object.update(dt)
 
+        for asteroid in asteroids:
+            if asteroid.collision(player):
+                print("Game over!")
+                return
+
         pygame.display.flip()
 
 if __name__ == "__main__":