Python Arcade – 添加关卡

在本文中，我们将学习如何在Python为我们的街机游戏添加不同的关卡。

添加级别

我们可以按照以下步骤轻松地为 Arcade 游戏添加多个关卡：

• 创建一个新变量来存储当前级别。

self.level = 1

• 借助 self.level 变量加载您将在当前关卡中使用的精灵。在本例中，我们将加载名为“Platform1”的第 1 级精灵，加载名为“Platform2”的第 2 级精灵，依此类推。为此，我们可以使用以下代码加载平台。

platform = arcade.Sprite(f"Platform{self.level}.png", 1)

• 如果玩家越过屏幕右侧，那么我们将增加 self.level 变量的值以进入下一个级别。

if self.player_sprite.center_x>690:
    self.level += 1

使用的功能：

• Camera()： Camera 类用于控制可见视口。

Syntax: arcade.Camera( width , height, window)

Parameters:

• width: width of the viewport
• height: height of the viewport
• window: Window to associate with this camera

• Scene()：表示场景对象的类。

Syntax: arcade.Scene(sprite_lists , name_mapping)

Parameters:

• sprite_lists: A list of SpriteList objects
• name_mapping: A dictionary of SpriteList objects

• PhysicsEnginePlatformer()：用于平台游戏的简单物理引擎。

Syntax: arcade.PhysicsEnginePlatformer( player_sprite , platforms, gravity, ladders)

Parameters:

• player_sprite: sprite of the player
• platforms: The sprites it can’t move through
• gravity: Downward acceleration per frame
• ladders: Ladders the user can climb on

使用的精灵：

在下面的示例中，我们将创建一个 MainGame() 类。首先在这个类中，我们将初始化一些变量，用于速度、相机、级别和玩家的精灵，然后我们将在这个类中创建 6 个函数。

• on_draw()：在这个函数，我们将使用我们的相机并绘制场景。
• setup()：在这个函数，我们将初始化我们的相机和场景对象，然后我们将加载我们的播放器和平台的精灵。之后，我们将调用 PhysicsEnginePlatformer()函数。
• on_update()：在这个函数，我们将更新玩家的精灵、相机和物理引擎的 x 坐标。我们还将在此函数更改我们的级别。
• on_key_press() 和 on_key_release()：在这个函数，我们将根据按下或释放的键盘键来改变速度变量的值。
• camera_move()：在这个函数，我们将根据玩家当前的位置移动我们的相机。

下面是实现：

Python3

# Importing arcade module
import arcade
  
# Creating MainGame class
class MainGame(arcade.Window):
    def __init__(self):
        super().__init__(600, 600,
                         title = "Player Movement")
  
        # Initializing a variable to store
        # the velocity of the player
        self.vel_x = 0
  
        # Creating variable for Camera
        self.camera = None
  
        # Creating variable to store current level
        self.level = 1
  
        # Creating scene object
        self.scene = None
  
        # Creating variable to store player sprite
        self.player = None
  
        # Creating variable for our game engine
        self.physics_engine = None
  
    # Creating on_draw() function to draw on the screen
    def on_draw(self):
        arcade.start_render()
  
        # Using the camera
        self.camera.use()
          
        # Drawing our scene
        self.scene.draw()
  
    def setup(self):
         # Initialize Scene object
        self.scene = arcade.Scene()
          
        # Using Camera() function
        self.camera = arcade.Camera(600, 600)
  
        # Creating different sprite lists
        self.scene.add_sprite_list("Player")
        self.scene.add_sprite_list("Platforms",
                                   use_spatial_hash=True)
  
        # Adding player sprite
        self.player_sprite = arcade.Sprite("Player.png", 1)
  
        # Adding coordinates for the center of the sprite
        self.player_sprite.center_x = 64
        self.player_sprite.center_y = 600
  
        # Adding Sprite in our scene
        self.scene.add_sprite("Player", self.player_sprite)
  
        # Adding platform sprite according to level
        platform = arcade.Sprite(f"Platform{self.level}.png", 1)
          
        # Adding coordinates for the center of the platform
        platform.center_x = 300
        platform.center_y = 32
        self.scene.add_sprite("Platforms", platform)
  
        # Creating Physics engine
        self.physics_engine = arcade.PhysicsEnginePlatformer(
            self.player_sprite, self.scene.get_sprite_list("Platforms"), 0.5
        )
  
    # Creating on_update function to
    # update the x coordinate
    def on_update(self, delta_time):
  
        # Changing x coordinate of player
        self.player_sprite.center_x += self.vel_x * delta_time
          
        # Updating the physics engine to move the player
        self.physics_engine.update()
  
        # Calling the camera_move function
        self.camera_move()
  
        # Changing level if player crosses the right
        # end of screen
        if self.player_sprite.center_x > 690:
            self.level += 1
            self.setup()
  
    # Creating function to change the velocity
    # when button is pressed
    def on_key_press(self, symbol, modifier):
  
        # Checking the button pressed
        # and changing the value of velocity
        if symbol == arcade.key.LEFT:
            self.vel_x = -300
        elif symbol == arcade.key.RIGHT:
            self.vel_x = 300
  
    # Creating function to change the velocity
    # when button is released
    def on_key_release(self, symbol, modifier):
  
        # Checking the button released
        # and changing the value of velocity
        if symbol == arcade.key.LEFT:
            self.vel_x = 0
        elif symbol == arcade.key.RIGHT:
            self.vel_x = 0
  
    def camera_move(self):
        
        # Getting the x coordinate for the center of camera
        screen_x = self.player_sprite.center_x - \
            (self.camera.viewport_width / 2)
          
        # Getting the y coordinate for the center of camera
        screen_y = self.player_sprite.center_y - \
            (self.camera.viewport_height / 2)
  
        # Moving the camera
        self.camera.move_to([screen_x, screen_y])
  
  
# Calling MainGame class
game = MainGame()
game.setup()
arcade.run()

输出：