外星人入侵

 此次小編上傳一個遊戲開發的項目，一方面是本身寫上去能更好的熟悉這個項目，而且把本身的心得能夠分享上面，另外一方面，可讓更多的盆友看到，提升自我。

       這個遊戲項目使用的是pygame，這是一組強大而有趣的模塊，可用於管理圖形，動畫乃至聲音，讓你能更輕鬆的開發複雜的遊戲，經過使用pygame來處理在屏幕上繪製圖像等任務，咱們不用考慮多繁瑣而艱難的編程工做，而是將重點放在程序上的高級邏輯上面。

第一步：規劃項目

   開發大型項目時候，作好規劃再動手編寫項目很重要，規劃能夠確保咱們不偏離軌道，從而提升項目成功的可能性。

    下面 來編寫有關遊戲《外星人入侵》的描述，可能其中沒有涵蓋全部的遊戲細節，可是嗯那個讓咱們狠清晰的知道如何動手開發它

        在遊戲《外星人入侵》中，玩家控制着一艘最初出如今屏幕底部中央的飛船。玩家可使用箭頭鍵左右移動飛船，還可使用空格鍵進行設計。遊戲開始時，一羣外星人出如今天空，他們在屏幕中向下移動。玩家的任務是射殺這些外星人。玩家將全部的外星人射擊乾淨後，將出現一個新的外星人，他們的移動宿舍更快。只要有外星人撞到玩家的飛船或者到達屏幕底部，玩家就損失一所飛船。玩家損失三艘飛船後，遊戲結束。

第二步：安裝pygame

       pygame項目託管在代碼分享網址Bitbucket中，要在windows系統中安裝pygame,則能夠訪問網站

https://bitbucket.org/pygame/pygame/downloads/

（在網址中查找合適的程序下載）

 

安裝程序以下：

pip install pygame-1.9.3-cp36-cp36m-win_amd64.whl

 第三步：開始遊戲項目

      首先得建立遊戲界面，而後添加飛船圖像，飛船添加上去，咱們必須容許它能夠左右移動，再添加射擊子彈的功能。

       而後建立外星人，讓外星人移動，咱們進行射擊外星人，而後結束遊戲。

       最後咱們得進行記分，提升等級等設置，急需完善遊戲，這樣一個遊戲就設置完畢。

   提及來簡單，可是作起來難。這三部分，每部分都是一個總體，並且實現新功能時候，必須重構源代碼，一不當心就出錯，因此得格外注意。

具體的項目實施步驟，我就在這裏不一一講解了，主要把代碼貼出來，讓你們參考一下

這個是全部代碼的目錄：

 

首先是主程序 alien_invasion.py

import pygame
from pygame.sprite import Group

from settings import Settings
from game_stats import GameStats
from scoreboard import Scoreboard
from button import Button
from ship import Ship
from alien import Alien
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")

    #建立play按鈕
    play_button = Button(ai_settings,screen,"Play")

    #建立一個用於存儲遊戲統計信息的實例
    stats = GameStats(ai_settings)
    sb = Scoreboard(ai_settings,screen,stats)

    # Set the background color.
    bg_color = (230, 230, 230)

    # Make a ship.
    ship = Ship(ai_settings, screen)
    # Make a group to store bullets in.
    bullets = Group()
    aliens = Group()

    #建立外星人羣
    gf.create_fleet(ai_settings,screen,ship,aliens)

    # Start the main loop for the game.
    while True:
        gf.check_events(ai_settings, screen, stats,sb,play_button,ship,
                        aliens, bullets)

        if stats.game_active:
            ship.update()
            gf.update_bullets(ai_settings,screen,stats,sb,ship,aliens,bullets)
            gf.update_aliens(ai_settings,screen,stats,sb,ship,aliens,bullets)

        gf.update_screen(ai_settings, screen,stats, sb,ship,aliens,
                         bullets,play_button)


run_game()

View Code

而後是功能函數 game_function.py

import sys
from time import sleep
import pygame

from bullet import Bullet
from alien import Alien
import pygame

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)


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, stats,sb, play_button,ship,aliens, 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)
        elif event.type == pygame.MOUSEBUTTONDOWN:
            mouse_x,mouse_y = pygame.mouse.get_pos()
            check_play_button(ai_settings, screen,stats,sb,play_button,
                              ship,aliens,bullets,mouse_x,mouse_y)


def check_play_button(ai_settings,screen,stats,sb,play_button, ship,aliens,bullets,mouse_x,mouse_y):
    """玩家單擊play按鈕開始新遊戲"""
    button_clicked = play_button.rect.collidepoint(mouse_x, mouse_y)
    if button_clicked and not stats.game_active:
        #重置遊戲設置
        ai_settings.initialize_dynamic_settings()

        #隱藏光標
        pygame.mouse.set_visible(False)
    if play_button.rect.collidepoint(mouse_x,mouse_y):
        #重置遊戲統計信息
        stats.reset_stats()
        stats.game_active = True

        #重置記分牌圖像
        sb.prep_score()
        sb.prep_high_score()
        sb.prep_level()
        sb.prep_ships()

        #清空外星人列表和子彈列表
        aliens.empty()
        bullets.empty()

        #建立一羣新的外星人，並讓其居中
        create_fleet(ai_settings,screen,ship,aliens)
        ship.center_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, stats,sb,ship,
                  aliens,bullets,play_button):
    """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)

    #顯示得分
    sb.show_score()

    #若是遊戲處於非活躍狀態，就繪製play按鈕
    if not stats.game_active:
        play_button.draw_button()


    # Make the most recently drawn screen visible.
    pygame.display.flip()


def update_bullets(ai_settings,screen,stats,sb,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,stats,sb,ship,aliens,bullets)

def check_bullet_alien_collisions(ai_settings,screen,stats,sb,ship,aliens,bullets):
    #檢查是否有子彈擊中了外星人
    #若是是這樣樣，就刪除相應的額子彈和外星人
    collisions = pygame.sprite.groupcollide(bullets,aliens,True,True)

    if collisions:
        for aliens in collisions.values():
            stats.score += ai_settings.alien_points*len(aliens)
            sb.prep_score()
        check_high_score(stats,sb)


    if len(aliens) == 0:
         # If the entire fleet is destroyed, start a new level.
        bullets.empty()
        ai_settings.increase_speed()

        #提升等級
        stats.level +=1
        sb.prep_level()

        create_fleet(ai_settings,screen,ship,aliens)



def get_number_aliens_x(ai_settings,alien_width):
    """計算每行可容納多少個外星人"""
    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,aliens_height):
    """計算屏幕能夠容納多少個外星人"""
    avaliable_space_y = (ai_settings.screen_height -(3*aliens_height)-ship_height)
    number_rows = int(avaliable_space_y /(2*aliens_height))
    return number_rows


def create_alien(ai_settings,screen,aliens,alien_number,row_number):
    """建立一個外星人並將其放在當前列"""
    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):
    """建立外星人羣"""
    #建立一個外星人，並計算一行能夠容納多少個外星人,外星人間距爲外星人的寬度
    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)

    #建立外星人羣
    for row_number in range(number_rows):
        for alien_number in range(number_aliens_x):
            #建立一個外星人並將其加入當前行
             create_alien(ai_settings,screen,aliens,alien_number,row_number)

def check_fleet_edges(ai_settings,aliens):
    """有外星人到達邊緣時候採起相應的措施"""
    for alien in aliens.sprites():
        if alien.check_edges():
            change_fleet_direction(ai_settings,aliens)
            break

def change_fleet_direction(ai_settings,aliens):
    """將整羣外星人下移，並改變他們的方向"""
    for alien in aliens.sprites():
        alien.rect.y += ai_settings.fleet_drop_speed
    ai_settings.fleet_direction *= -1


def update_aliens(ai_settings,screen,stats,sb,ship,aliens,bullets):
    """檢查是否有外星人位於屏幕邊緣，更新外星人羣中全部外星人的位置"""
    check_fleet_edges(ai_settings,aliens)
    aliens.update()

    #監測外星人和飛船之間的碰撞
    if pygame.sprite.spritecollideany(ship,aliens):
        ship_hit(ai_settings,screen,stats,sb,ship,aliens,bullets)

    #檢查是狗友外星人到達屏幕底部
    check_aliens_bottom(ai_settings,screen,stats,sb,ship,aliens,bullets)

def ship_hit(ai_settings,screen,stats,sb,ship,aliens,bullents):
    """響應被外星人撞到的飛船"""

    if stats.ships_left >0:
        # 將shios_left減1
        stats.ships_left -=1

        #更新記分牌
        sb.prep_ships()

    else:
        stats.game_active = False
        #清空外星人列表和子彈列表
        pygame.mouse.set_visible(True)

    aliens.empty()
    bullents.empty()

    #建立一羣新的外星人
    create_fleet(ai_settings,screen,ship,aliens)
    ship.center_ship()

    #暫停
    sleep(3)

def check_aliens_bottom(ai_settings,screen,stats,ship,sb,aliens,bullets):
    """檢查是否有外星人到達了屏幕底部"""
    screen_rect = screen.get_rect()
    for alien in aliens.sprites():
        if alien.rect.bottom >= screen_rect.bottom:
             #像飛船被撞到同樣處理
             ship_hit(ai_settings,stats,screen,ship,sb,aliens,bullets)
             break

def check_high_score(stats,sb):
    """檢查是否誕生了新的得分最高"""
    if stats.score > stats.high_score:
        stats.high_score = stats.score
        sb.prep_high_score()

View Code

下面是設置函數 settings

class Settings():
    """A class to store all settings for Alien Invasion."""

    def __init__(self):
        """Initialize the game's settings."""
        # Screen settings
        self.screen_width = 1100
        self.screen_height = 700
        self.bg_color = (230, 230, 230)

        # 飛船設置
        #self.ship_speed_factor = 1.5
        #self.bullet_speed_factor = 3
        self.ship_limit = 3

        # Bullet settings
        self.bullet_speed_factor = 3
        self.bullet_width = 3
        self.bullet_height = 25
        self.bullet_color = 60, 60, 60
        self.bullets_allowed = 2

        #外星人設置
        #self.alien_speed_factor = 1
        self.fleet_drop_speed = 10
        #fleet_direction爲1表示向右移動，-1表示向左移動
        self.fleet_direction = 1

        #以什麼樣的速度加快遊戲節奏
        self.fleet_drop_speed = 10

        #加快遊戲節奏的速度
        self.speedup_scale = 1.1
        #外星人點數提升
        self.score_scale = 1.5

        self.initialize_dynamic_settings()

    def increase_speed(self):
        """提升速度設置"""
        self.ship_speed_factor *= self.speedup_scale
        self.bullet_speed_factor *= self.speedup_scale
        self.alien_speed_factor *= self.speedup_scale

        self.alien_points  = int(self.alien_points * self.score_scale)
        #print(self.alien_points)

    def initialize_dynamic_settings(self):
        """初始化歲遊戲進行二變化的設置"""
        self.ship_speed_factor = 1.5
        self.bullet_speed_factor = 3
        self.alien_speed_factor = 3

        # fleet_direction爲1表示向右移動，-1表示向左移動
        self.fleet_direction = 1

        #積分
        self.alien_points = 50

View Code

這個是我方飛機的設置函數ship.py

import pygame
from pygame.sprite import Sprite

class Ship(Sprite):
    def __init__(self, ai_settings, screen):
        """Initialize the ship, and set its starting position."""
        super(Ship,self).__init__()

        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 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)

    def center_ship(self):
         """讓飛船在屏幕上劇中"""
         self.center = self.screen_rect.centerx

View Code

這個是敵方飛機的設置函數alien.py

import pygame
from pygame.sprite import Sprite

class Alien(Sprite):
    """表示單個外星人"""

    def __init__(self,ai_settings,screen):
        """初始化外星人並設置其起始位置"""
        super(Alien,self).__init__()
        self.screen = screen
        self.ai_settings = ai_settings

        #加載外星人圖像，並設置rect屬性
        self.image = pygame.image.load('images/alien.bmp')
        self.rect = self.image.get_rect()

        #每一個外星人最初都在屏幕右上角附近
        self.rect.x = self.rect.width
        self.rect.y = self.rect.height

        #存儲外星人的準確位置
        self.x = float(self.rect.x)

    def check_edges(self):
        """若是外星人位於屏幕邊緣，就返回True"""
        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):
        """向左或者向右移動外星人"""
        self.x  += (self.ai_settings.fleet_direction * self.ai_settings.alien_speed_factor)
        self.rect.x = self.x

    def blitme(self):
        """在指定位置繪製外星人"""
        self.screen.blit(self.image,self.rect)

View Code

這個是子彈設置的函數bullet.py

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 a bullet rect at (0, 0) and 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 the bullet's position as a decimal value.
        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)

View Code

這個是按鈕設置的函數button.py

import pygame.font

class  Button():

    def __init__(self,ai_settings,screen,msg):
        """初始化按鈕的屬性"""
        self.screen = screen
        self.screen_rect = screen.get_rect()

        #設置按鈕的尺寸和其餘屬性
        self.width,self.height = 200,50
        self.button_color = (0,255,0)
        self.text_color = (255,255,255)
        self.font = pygame.font.SysFont(None,48)

        #建立按鈕的rect對象，並使其劇中
        self.rect = pygame.Rect(0,0,self.width,self.height)
        self.rect.center = self.screen_rect.center

        #按鈕的標籤只須要一次
        self.prep_msg(msg)

    def prep_msg(self,msg):
        """將msg渲染爲圖像，並使其在按鈕上居中"""
        self.msg_image = self.font.render(msg,True,self.text_color,self.button_color)
        self.msg_image_rect = self.msg_image.get_rect()
        self.msg_image_rect.center = self.rect.center


    def draw_button(self):
        #繪製一個用顏色填充的按鈕，再繪製文本
        self.screen.fill(self.button_color,self.rect)
        self.screen.blit(self.msg_image,self.msg_image_rect)

View Code

這個是記分牌設置的函數scoreboard.py

import pygame.font
from pygame.sprite import Group

from  ship import Ship

class Scoreboard():
    """顯示得分信息的類"""
    def __init__(self,ai_settings,screen,stats):
        """初始化顯示得分涉及的屬性"""
        self.screen = screen
        self.screen_rect = screen.get_rect()
        self.ai_settings = ai_settings
        self.stats = stats


        #顯示得分信息時候使用的字體設置
        self.text_color = (30,30,30)
        self.font = pygame.font.SysFont(None,48)

        #準備初始得分圖像
        self.prep_score()
        self.prep_high_score()
        self.prep_level()
        self.prep_ships()

        #準備包含最高分和當前的分的圖像
        self.prep_score()
        self.prep_high_score()


    def prep_score(self):
        """將得分轉化爲一副渲染的圖像"""
        rounded_score = int(round(self.stats.score,-1))
        score_str = "{: ,}".format(rounded_score)
        self.score_image = self.font.render(score_str,True,self.text_color,
                                            self.ai_settings.bg_color)

        #將得分放在屏幕右上角
        self.score_rect = self.score_image.get_rect()
        self.score_rect.right = self.screen_rect.right -20
        self.score_rect.top = 20

    def prep_high_score(self):
        """將最高分轉換爲渲染的圖像"""
        high_score = int(round(self.stats.high_score,-1))
        high_score_str = "{: ,}".format(high_score)
        self.high_score_image = self.font.render(high_score_str, True,
                                                 self.text_color,self.ai_settings.bg_color)

        # 將最高得分放在屏幕中央
        self.high_score_rect = self.high_score_image.get_rect()
        self.high_score_rect.centerx = self.screen_rect.centerx
        self.high_score_rect.top = self.score_rect.top

    def show_score(self):
        """在屏幕上顯示得分和最高得分"""
        self.screen.blit(self.score_image,self.score_rect)
        self.screen.blit(self.high_score_image,self.high_score_rect)
        self.screen.blit(self.level_image,self.level_rect)
        #繪製飛船
        self.ships.draw(self.screen)

    def prep_level(self):
        """將等級轉化爲渲染的圖像"""
        self.level_image = self.font.render(str(self.stats.level),True,
                                            self.text_color,self.ai_settings.bg_color)

        #將等級放在得分下面
        self.level_rect = self.level_image.get_rect()
        self.level_rect.right = self.score_rect.right
        self.level_rect.top = self.score_rect.bottom +10


    def prep_ships(self):
        """顯示還剩下多少搜飛船"""
        self.ships = Group()
        for ship_number in range(self.stats.ships_left):
            ship = Ship(self.ai_settings,self.screen)
            ship.rect.x = 10+ship_number * ship.rect.width
            ship.rect.y = 10
            self.ships.add(ship)

View Code

這個是跟蹤遊戲統計信息的類game_stats.py

class GameStats():
    """跟蹤遊戲的統計信息"""

    def __init__(self,ai_settings):
        """初始化統計信息"""
        self.ai_settings = ai_settings
        self.reset_stats()

        #遊戲剛開始處於0活躍狀態
        self.game_active = False

        #在任何狀況下都不該重置最高得分
        self.high_score = 0

    def reset_stats(self):
        """初始化在遊戲與逆行期間可能變化的統計信息"""
        self.ships_left = self.ai_settings.ship_limit
        self.score = 0
        self.level = 1

View Code

第四步：遊戲結果展現

圖一：開始界面圖：

圖二：遊戲中的圖

 

 

第五步：遊戲總結

  這個遊戲作的比較倉促，還存在許多問題，因爲小編只是熟悉一下pygame，因此並沒作更深層次的改進。放到這裏，一方面記錄本身的學習進度，另外一方面也但願有想在遊戲方面開發的朋友繼續改進。

   改進建議一：敵方飛機設置的太多，遊戲體驗不是很好（這個問題，能夠對aliens函數進行修改，從而修改敵方飛機的存在個數等）

  改進建議二：每當玩家關閉遊戲並從新開啓時候，最高分都會被重置（這個問題，能夠調用在sys.exit()前，將最高分寫入文件，並在遊戲記錄裏面初始化最高分而且讀取它）

  改進建議三：能夠擴展遊戲，好比讓外星人也能夠射擊飛船，或者外星人加盾等

  改進建議四：能夠給遊戲加上音效，讓玩家獲得更好的遊戲體驗

  改進建議五：能夠在關卡後面，提升難度不止是敵方飛機速度的加快，也能夠是更難打

  改進建議六 ：能夠設置雙人遊戲，在一臺操做器上面

  改進建議七：能夠設置局域網，讓多人聯網操做（可是操做只是讓設計者熟悉局域網的代碼設置）

（。。。。之後有什麼更好的想法，能夠補上來，要是有時間或者作這個方向的話，能夠再擴展這個代碼，這個項目是參考《python編程從入門到實踐 》的項目）