def create_sprites(self):
     self.player = Player((PLAY_SCREEN_RECT.width / 2, PLAY_SCREEN_RECT.bottom - 20))
     for i in xrange(20):
         Alien(((i % 10) * 40 + 20,(i / 10) * 40 + 20))
     self.high_score = HighScore((PLAY_SCREEN_RECT.topright))
     self.score = Score((PLAY_SCREEN_RECT.topright[0], PLAY_SCREEN_RECT.topright[1] + 75))
class ScenePlay(SceneBase):
    def __init__(self, game_manager):
        SceneBase.__init__(self, game_manager)
        self.load_images()
        self.load_sounds()
        self.create_group()
        self.create_sprites()
        self.playing = True

    def update(self, filtered_events, pressed_keys):
        self.player.input(pressed_keys)
        self.all.update()
        self.collide_alien_shot()
        if self.playing:
            self.collide_player_beam()
            if self.check_gameover():
                self.game_manager.change_scene(SceneGameOver(self.game_manager, self))
                self.playing = False
            elif self.check_gameclear():
                self.game_manager.change_scene(SceneGameClear(self.game_manager, self))
                self.playing = False

    def draw(self, screen):
        self.all.draw(screen)
        self.score.draw(screen)
        self.high_score.draw(screen)

    def load_images(self):
        Alien.load_image()
        Beam.load_image()
        Explosion.load_image()
        Player.load_image()
        Shot.load_image()

    def load_sounds(self):
        Alien.load_sound()
        Player.load_sound()
        Shot.load_sound()

    def create_group(self):
        self.all = pygame.sprite.RenderUpdates()
        self.aliens = pygame.sprite.Group()
        self.beams = pygame.sprite.Group()
        self.shots = pygame.sprite.Group()
        Alien.containers = self.all, self.aliens
        Beam.containers = self.all, self.beams
        Explosion.containers = self.all
        Player.containers = self.all
        Shot.containers = self.all, self.shots

    def create_sprites(self):
        self.player = Player((PLAY_SCREEN_RECT.width / 2, PLAY_SCREEN_RECT.bottom - 20))
        for i in xrange(20):
            Alien(((i % 10) * 40 + 20,(i / 10) * 40 + 20))
        self.high_score = HighScore((PLAY_SCREEN_RECT.topright))
        self.score = Score((PLAY_SCREEN_RECT.topright[0], PLAY_SCREEN_RECT.topright[1] + 75))

    def collide_alien_shot(self):
        alien = pygame.sprite.groupcollide(self.aliens, self.shots, True, True)
        for alien in alien.keys():
            Explosion(alien.rect.center)
            Alien.sound.play()
            self.score.add_score(alien.score)

    def collide_player_beam(self):
        if pygame.sprite.spritecollide(self.player, self.beams, True):
            Explosion(self.player.rect.center)
            Player.sound.play()
            self.player.kill()

    def check_gameclear(self):
        for alien in self.aliens:
            if alien.alive():
                return False
        return True

    def check_gameover(self):
        if not self.player.alive():
            return True
        for alien in self.aliens:
            if self.player.rect.centery <= alien.rect.centery:
                return True
        return False

    def update_score(self):
        if self.score.get_score() > self.high_score.get_score():
            self.high_score.save_score(self.score.get_score())