1.创建 Pygame 窗口以及响应用户输入
pip install pygame安装库文件
alien_invasion.py
import pygame
from pygame.sprite import Group
from settings import Settings
from game_stats import GameStats
from ship import Ship
import game_functions as gf
def run_game():
# Initialize pygame, settings, and screen object.
pygame.init()
ai_settings = Settings()
screen = pygame.display.set_mode(
(ai_settings.screen_width, ai_settings.screen_height))
pygame.display.set_caption("Alien Invasion")
# Create an instance to store game statistics.
stats = GameStats(ai_settings)
# Set the background color.
bg_color = (230, 230, 230)
# Make a ship, a group of bullets, and a group of aliens.
ship = Ship(ai_settings, screen)
bullets = Group()
aliens = Group()
# Create the fleet of aliens.
gf.create_fleet(ai_settings, screen, ship, aliens)
# Start the main loop for the game.
while True:
gf.check_events(ai_settings, screen, ship, bullets)
if stats.game_active:
ship.update()
gf.update_bullets(ai_settings, screen, ship, aliens, bullets)
gf.update_aliens(ai_settings, stats, screen, ship, aliens, bullets)
gf.update_screen(ai_settings, screen, ship, aliens, bullets)
run_game()2.创建设置类
class Settings():
"""A class to store all settings for Alien Invasion."""
def __init__(self):
"""Initialize the game's settings."""
# Screen settings.
self.screen_width = 1200
self.screen_height = 800
self.bg_color = (230, 230, 230)
# Ship settings.
self.ship_speed_factor = 1.5
self.ship_limit = 3
# Bullet settings.
self.bullet_speed_factor = 3
self.bullet_width = 3
self.bullet_height = 15
self.bullet_color = 60, 60, 60
self.bullets_allowed = 3
# Alien settings.
self.alien_speed_factor = 1
self.fleet_drop_speed = 10
# fleet_direction of 1 represents right, -1 represents left.
self.fleet_direction = 13.创建 Ship 类
import pygame
class Ship():
def __init__(self, ai_settings, screen):
"""Initialize the ship, and set its starting position."""
self.screen = screen
self.ai_settings = ai_settings
# Load the ship image, and get its rect.
self.image = pygame.image.load('images/ship.bmp')
self.rect = self.image.get_rect()
self.screen_rect = screen.get_rect()
# Start each new ship at the bottom center of the screen.
self.rect.centerx = self.screen_rect.centerx
self.rect.bottom = self.screen_rect.bottom
# Store a decimal value for the ship's center.
self.center = float(self.rect.centerx)
# Movement flags.
self.moving_right = False
self.moving_left = False
def center_ship(self):
"""Center the ship on the screen."""
self.center = self.screen_rect.centerx
def update(self):
"""Update the ship's position, based on movement flags."""
# Update the ship's center value, not the rect.
if self.moving_right and self.rect.right < self.screen_rect.right:
self.center += self.ai_settings.ship_speed_factor
if self.moving_left and self.rect.left > 0:
self.center -= self.ai_settings.ship_speed_factor
# Update rect object from self.center.
self.rect.centerx = self.center
def blitme(self):
"""Draw the ship at its current location."""
self.screen.blit(self.image, self.rect)4.创建images
alien.bmp
ship.bmp
5.创建alien类
import pygame
from pygame.sprite import Sprite
class Alien(Sprite):
"""A class to represent a single alien in the fleet."""
def __init__(self, ai_settings, screen):
"""Initialize the alien, and set its starting position."""
super(Alien, self).__init__()
self.screen = screen
self.ai_settings = ai_settings
# Load the alien image, and set its rect attribute.
self.image = pygame.image.load('images/alien.bmp')
self.rect = self.image.get_rect()
# Start each new alien near the top left of the screen.
self.rect.x = self.rect.width
self.rect.y = self.rect.height
# Store the alien's exact position.
self.x = float(self.rect.x)
def check_edges(self):
"""Return True if alien is at edge of screen."""
screen_rect = self.screen.get_rect()
if self.rect.right >= screen_rect.right:
return True
elif self.rect.left <= 0:
return True
def update(self):
"""Move the alien right or left."""
self.x += (self.ai_settings.alien_speed_factor *
self.ai_settings.fleet_direction)
self.rect.x = self.x
def blitme(self):
"""Draw the alien at its current location."""
self.screen.blit(self.image, self.rect)6.创建bullet类
import pygame
from pygame.sprite import Sprite
class Bullet(Sprite):
"""A class to manage bullets fired from the ship."""
def __init__(self, ai_settings, screen, ship):
"""Create a bullet object, at the ship's current position."""
super(Bullet, self).__init__()
self.screen = screen
# Create bullet rect at (0, 0), then set correct position.
self.rect = pygame.Rect(0, 0, ai_settings.bullet_width,
ai_settings.bullet_height)
self.rect.centerx = ship.rect.centerx
self.rect.top = ship.rect.top
# Store a decimal value for the bullet's position.
self.y = float(self.rect.y)
self.color = ai_settings.bullet_color
self.speed_factor = ai_settings.bullet_speed_factor
def update(self):
"""Move the bullet up the screen."""
# Update the decimal position of the bullet.
self.y -= self.speed_factor
# Update the rect position.
self.rect.y = self.y
def draw_bullet(self):
"""Draw the bullet to the screen."""
pygame.draw.rect(self.screen, self.color, self.rect)7.创建game_functions
import sys
from time import sleep
import pygame
from bullet import Bullet
from alien import Alien
def check_keydown_events(event, ai_settings, screen, ship, bullets):
"""Respond to keypresses."""
if event.key == pygame.K_RIGHT:
ship.moving_right = True
elif event.key == pygame.K_LEFT:
ship.moving_left = True
elif event.key == pygame.K_SPACE:
fire_bullet(ai_settings, screen, ship, bullets)
elif event.key == pygame.K_q:
sys.exit()
def check_keyup_events(event, ship):
"""Respond to key releases."""
if event.key == pygame.K_RIGHT:
ship.moving_right = False
elif event.key == pygame.K_LEFT:
ship.moving_left = False
def check_events(ai_settings, screen, ship, bullets):
"""Respond to keypresses and mouse events."""
for event in pygame.event.get():
if event.type == pygame.QUIT:
sys.exit()
elif event.type == pygame.KEYDOWN:
check_keydown_events(event, ai_settings, screen, ship, bullets)
elif event.type == pygame.KEYUP:
check_keyup_events(event, ship)
def fire_bullet(ai_settings, screen, ship, bullets):
"""Fire a bullet, if limit not reached yet."""
# Create a new bullet, add to bullets group.
if len(bullets) < ai_settings.bullets_allowed:
new_bullet = Bullet(ai_settings, screen, ship)
bullets.add(new_bullet)
def update_screen(ai_settings, screen, ship, aliens, bullets):
"""Update images on the screen, and flip to the new screen."""
# Redraw the screen, each pass through the loop.
screen.fill(ai_settings.bg_color)
# Redraw all bullets, behind ship and aliens.
for bullet in bullets.sprites():
bullet.draw_bullet()
ship.blitme()
aliens.draw(screen)
# Make the most recently drawn screen visible.
pygame.display.flip()
def update_bullets(ai_settings, screen, ship, aliens, bullets):
"""Update position of bullets, and get rid of old bullets."""
# Update bullet positions.
bullets.update()
# Get rid of bullets that have disappeared.
for bullet in bullets.copy():
if bullet.rect.bottom <= 0:
bullets.remove(bullet)
check_bullet_alien_collisions(ai_settings, screen, ship, aliens, bullets)
def check_bullet_alien_collisions(ai_settings, screen, ship, aliens, bullets):
"""Respond to bullet-alien collisions."""
# Remove any bullets and aliens that have collided.
collisions = pygame.sprite.groupcollide(bullets, aliens, True, True)
if len(aliens) == 0:
# Destroy existing bullets, and create new fleet.
bullets.empty()
create_fleet(ai_settings, screen, ship, aliens)
def check_fleet_edges(ai_settings, aliens):
"""Respond appropriately if any aliens have reached an edge."""
for alien in aliens.sprites():
if alien.check_edges():
change_fleet_direction(ai_settings, aliens)
break
def change_fleet_direction(ai_settings, aliens):
"""Drop the entire fleet, and change the fleet's direction."""
for alien in aliens.sprites():
alien.rect.y += ai_settings.fleet_drop_speed
ai_settings.fleet_direction *= -1
def ship_hit(ai_settings, stats, screen, ship, aliens, bullets):
"""Respond to ship being hit by alien."""
if stats.ships_left > 0:
# Decrement ships_left.
stats.ships_left -= 1
else:
stats.game_active = False
# Empty the list of aliens and bullets.
aliens.empty()
bullets.empty()
# Create a new fleet, and center the ship.
create_fleet(ai_settings, screen, ship, aliens)
ship.center_ship()
# Pause.
sleep(0.5)
def check_aliens_bottom(ai_settings, stats, screen, ship, aliens, bullets):
"""Check if any aliens have reached the bottom of the screen."""
screen_rect = screen.get_rect()
for alien in aliens.sprites():
if alien.rect.bottom >= screen_rect.bottom:
# Treat this the same as if the ship got hit.
ship_hit(ai_settings, stats, screen, ship, aliens, bullets)
break
def update_aliens(ai_settings, stats, screen, ship, aliens, bullets):
"""
Check if the fleet is at an edge,
then update the postions of all aliens in the fleet.
"""
check_fleet_edges(ai_settings, aliens)
aliens.update()
# Look for alien-ship collisions.
if pygame.sprite.spritecollideany(ship, aliens):
ship_hit(ai_settings, stats, screen, ship, aliens, bullets)
# Look for aliens hitting the bottom of the screen.
check_aliens_bottom(ai_settings, stats, screen, ship, aliens, bullets)
def get_number_aliens_x(ai_settings, alien_width):
"""Determine the number of aliens that fit in a row."""
available_space_x = ai_settings.screen_width - 2 * alien_width
number_aliens_x = int(available_space_x / (2 * alien_width))
return number_aliens_x
def get_number_rows(ai_settings, ship_height, alien_height):
"""Determine the number of rows of aliens that fit on the screen."""
available_space_y = (ai_settings.screen_height -
(3 * alien_height) - ship_height)
number_rows = int(available_space_y / (2 * alien_height))
return number_rows
def create_alien(ai_settings, screen, aliens, alien_number, row_number):
"""Create an alien, and place it in the row."""
alien = Alien(ai_settings, screen)
alien_width = alien.rect.width
alien.x = alien_width + 2 * alien_width * alien_number
alien.rect.x = alien.x
alien.rect.y = alien.rect.height + 2 * alien.rect.height * row_number
aliens.add(alien)
def create_fleet(ai_settings, screen, ship, aliens):
"""Create a full fleet of aliens."""
# Create an alien, and find number of aliens in a row.
alien = Alien(ai_settings, screen)
number_aliens_x = get_number_aliens_x(ai_settings, alien.rect.width)
number_rows = get_number_rows(ai_settings, ship.rect.height,
alien.rect.height)
# Create the fleet of aliens.
for row_number in range(number_rows):
for alien_number in range(number_aliens_x):
create_alien(ai_settings, screen, aliens, alien_number,
row_number)8.创建game_stats
class GameStats():
"""Track statistics for Alien Invasion."""
def __init__(self, ai_settings):
"""Initialize statistics."""
self.ai_settings = ai_settings
self.reset_stats()
# Start Alien Invasion in an active state.
self.game_active = True
def reset_stats(self):
"""Initialize statistics that can change during the game."""
self.ships_left = self.ai_settings.ship_limit参考书目：
python编程从入门到实践
