alien_invasion.py

import sys
from time import sleep

import pygame

from settings import Settings
from game_stats import GameStats
from scoreboard import Scoreboard
from button import Button
from ship import Ship
from bullet import Bullet
from ops import Alien

class AlienInvasion:
	"""Overall class to manage game assets and behavior"""

	def __init__(self):
		"""Initialize the game, and create game resources"""
		pygame.init()
		self.game_active = True
		self.clock = pygame.time.Clock()
		self.settings = Settings()
	
		self.screen = pygame.display.set_mode((self.settings.screen_width, self.settings.screen_height), pygame.RESIZABLE)
		pygame.display.set_caption("Alien Invasion")
		
		self.stats = GameStats(self)
		self.sb = Scoreboard(self)
	
		self.ship = Ship(self)
		self.bullets = pygame.sprite.Group()
		self.aliens = pygame.sprite.Group()

		self._create_fleet()
	
	def run_game(self):
		"""Start the main loop for the game"""
		while True:
			self._check_events()
			if self.game_active:
				self._check_fleet_edges()
				self.ship.update()
				self._update_bullets()
				self._update_aliens()
			self._update_screen()
			self.clock.tick(154)

	def _check_aliens_bottom(self):
		"""bottom ops"""
		for alien in self.aliens.sprites():
			if alien.rect.bottom >= self.settings.screen_height:
				self._ship_hit()
				break

	def _check_bullet_alien_collisions(self):
		"""bullet-ops collison"""
		collisions = pygame.sprite.groupcollide(self.bullets, self.aliens, True, True)
		if collisions:
			for aliens in collisions.values():
				self.stats.score += self.settings.alien_points * len(aliens)
			self.sb.prep_score()
			self.sb.prep_level()
			self.sb.prep_ships()
			self.sb.check_high_score()
		if not self.aliens:
			self.bullets.empty()
			self._create_fleet()
			self.settings.increase_speed()
			self.stats.level += 1
			self.sb.prep_level()

	def _check_events(self):
		for event in pygame.event.get():
			if event.type == pygame.QUIT:
				sys.exit()
			elif event.type == pygame.KEYDOWN:
				self._check_keydown_events(event)
			elif event.type == pygame.KEYUP:
				self._check_keyup_events(event)
			elif event.type == pygame.MOUSEBUTTONDOWN:
				mouse_pos = pygame.mouse.get_pos()
				self._check_play_button(mouse_pos)

	def _check_fleet_edges(self):
		"""Move aliens on edge detection"""
		for alien in self.aliens.sprites():
			if alien.check_edges():
				self._change_fleet_direction()
				break
	
	def _change_fleet_direction(self):
		"""Drop aliens"""
		for alien in self.aliens.sprites():
			alien.rect.y += self.settings.fleet_drop_speed
		self.settings.fleet_direction *= -1
		

	def _check_keydown_events(self, event):
			"""Keypress"""
			if event.key == pygame.K_f:
				self.ship.moving_right = True
			elif event.key == pygame.K_s:
				self.ship.moving_left = True
			elif event.key == pygame.K_SPACE:
				self._fire_bullet()
			elif event.key == pygame.K_ESCAPE:
				sys.exit()

	def _check_keyup_events(self, event):
			"""Keyrealse"""
			if event.key == pygame.K_f:
				self.ship.moving_right = False
			elif event.key == pygame.K_s:
				self.ship.moving_left = False

	def _check_play_button(self, mouse_pos):
		"""Start on click"""
		if self.play_button.rect.collidepoint(mouse_pos):
			self.stats.reset_stats()
			self.game_active = True
			self.bullets.empty()
			self.aliens.empty()
			self._create_fleet()
			self.ship.center_ship()
			pygame.mouse.set_visible(False)
			self.settings.initialize_dynamic_settings()

	def _create_alien(self, x_position, y_position):
		"""Alien"""
		new_alien = Alien(self)
		new_alien.x = x_position
		new_alien.rect.x = x_position;
		new_alien.rect.y = y_position;
		self.aliens.add(new_alien)

	def _create_fleet(self):
		"""Alien fleet"""
		alien = Alien(self)
		alien_width, alien_height = alien.rect.size

		current_x, current_y = alien_width, alien_height
		while current_y < (self.settings.screen_height - 3 * alien_height):
			while current_x < (self.settings.screen_width - 2 * alien_width):
				self._create_alien(current_x, current_y)
				current_x += 2 * alien_width

			current_x = alien_width
			current_y += 2 * alien_height

	def _fire_bullet(self):
		if len(self.bullets) < self.settings.bullets_allowed:
			new_bullet = Bullet(self)
			self.bullets.add(new_bullet)

	def _ship_hit(self):
		"""React to hits"""
		if self.stats.ships_left > 0:
			self.stats.ships_left -= 1
			self.sb.prep_ships()
			self.bullets.empty()
			self.aliens.empty()
			self._create_fleet()
			self.ship.center_ship()
			sleep(0.5)
		else:
			self.game_active = False
			pygame.mouse.set_visible(True)
		
		self.play_button = Button(self, "Play")

	def _update_aliens(self):
		"""Move aliens"""
		self.aliens.update()
		if pygame.sprite.spritecollideany(self.ship, self.aliens):
			self._ship_hit()
		self._check_aliens_bottom

	def _update_bullets(self):
		self.bullets.update()
		for bullet in self.bullets.copy():
			if bullet.rect.bottom <= 0:
				self.bullets.remove(bullet)
		self._check_bullet_alien_collisions()


	def _update_screen(self):
		# Redraw the screen during each pass through the loop.
		self.screen.fill(self.settings.bg_color)
		for bullet in self.bullets.sprites():
			bullet.draw_bullet()
		self.ship.blitme()
		self.aliens.draw(self.screen)
		self.sb.show_score()

		if not self.game_active:
			self.play_button.draw_button()

		pygame.display.flip()

if __name__ == '__main__':
# Make a game instance, and run the game.
	ai = AlienInvasion()
	ai.run_game()