142 lines
4.7 KiB
Python
142 lines
4.7 KiB
Python
import sys
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import pygame
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from settings import Settings
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from ship import Ship
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from bullet import Bullet
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from alien import Alien
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class AlienInvasion:
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"""Overall class to manage game assets and behavior."""
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def __init__(self):
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"""Initialize the game, and create game resources."""
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pygame.init()
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self.clock = pygame.time.Clock()
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self.settings = Settings()
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self.screen = pygame.display.set_mode(
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(self.settings.screen_width, self.settings.screen_height))
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pygame.display.set_caption("Alien Invasion")
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self.ship = Ship(self)
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self.bullets = pygame.sprite.Group()
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self.aliens = pygame.sprite.Group()
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self._create_fleet()
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def run_game(self):
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"""Start the main loop for the game."""
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while True:
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self._check_events()
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self.ship.update()
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self._update_bullets()
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self._update_aliens()
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self._update_screen()
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self.clock.tick(60)
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def _check_events(self):
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"""Respond to keypresses and mouse events."""
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for event in pygame.event.get():
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if event.type == pygame.QUIT:
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sys.exit()
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elif event.type == pygame.KEYDOWN:
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self._check_keydown_events(event)
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elif event.type == pygame.KEYUP:
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self._check_keyup_events(event)
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def _check_keydown_events(self, event):
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"""Respond to keypresses."""
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if event.key == pygame.K_RIGHT:
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self.ship.moving_right = True
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elif event.key == pygame.K_LEFT:
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self.ship.moving_left = True
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elif event.key == pygame.K_q:
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sys.exit()
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elif event.key == pygame.K_SPACE:
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self._fire_bullet()
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def _check_keyup_events(self, event):
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"""Respond to key releases."""
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if event.key == pygame.K_RIGHT:
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self.ship.moving_right = False
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elif event.key == pygame.K_LEFT:
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self.ship.moving_left = False
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def _fire_bullet(self):
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"""Create a new bullet and add it to the bullets group."""
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if len(self.bullets) < self.settings.bullets_allowed:
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new_bullet = Bullet(self)
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self.bullets.add(new_bullet)
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def _update_bullets(self):
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"""Update position of bullets and get rid of old bullets."""
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# Update bullet positions.
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self.bullets.update()
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# Get rid of bullets that have disappeared.
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for bullet in self.bullets.copy():
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if bullet.rect.bottom <= 0:
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self.bullets.remove(bullet)
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def _update_aliens(self):
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"""Update the positions of all aliens in the fleet."""
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"""Check if the fleet is at an edge, then update positions."""
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self._check_fleet_edges()
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self.aliens.update()
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def _create_fleet(self):
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"""Create the fleet of aliens."""
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# Create an alien and keep adding aliens until there's no room left.
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# Spacing between aliens is one alien width and one alien height.
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alien = Alien(self)
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alien_width, alien_height = alien.rect.size
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current_x, current_y = alien_width, alien_height
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while current_y < (self.settings.screen_height - 3 * alien_height):
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while current_x < (self.settings.screen_width - 2 * alien_width):
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self._create_alien(current_x, current_y)
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current_x += 2 * alien_width
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# Finished a row; reset x value, and increment y value.
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current_x = alien_width
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current_y += 2 * alien_height
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def _create_alien(self, x_position, y_position):
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"""Create an alien and place it in the fleet."""
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new_alien = Alien(self)
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new_alien.x = x_position
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new_alien.rect.x = x_position
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new_alien.rect.y = y_position
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self.aliens.add(new_alien)
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def _check_fleet_edges(self):
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"""Respond appropriately if any aliens have reached an edge."""
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for alien in self.aliens.sprites():
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if alien.check_edges():
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self._change_fleet_direction()
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break
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def _change_fleet_direction(self):
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"""Drop the entire fleet and change the fleet's direction."""
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for alien in self.aliens.sprites():
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alien.rect.y += self.settings.fleet_drop_speed
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self.settings.fleet_direction *= -1
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def _update_screen(self):
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"""Update images on the screen, and flip to the new screen."""
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self.screen.fill(self.settings.bg_color)
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for bullet in self.bullets.sprites():
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bullet.draw_bullet()
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self.ship.blitme()
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self.aliens.draw(self.screen)
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pygame.display.flip()
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if __name__ == '__main__':
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# Make a game instance, and run the game.
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ai = AlienInvasion()
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ai.run_game() |