步骤6-重置#

您可能已经注意到，在本教程中，有一个 setup 函数在我们的窗口类中。到目前为止，我们根本没有使用这个函数，那么它是做什么的呢？

让我们设想一下，我们想要一种将游戏“重置”到初始状态的方法。这可能是因为玩家输了，我们想重新开始比赛，或者我们只是想给玩家重新开始的选项。

使用我们目前的架构，在我们的 __init__ 函数，我们将不得不在另一个函数中复制所有逻辑以实现这一点，或者完全重新创建我们的窗口，这对玩家来说将是一种不愉快的体验。

在本章中，我们将对现有代码进行少量重新组织，以便以一种允许简单地调用 setup 功能，只要我们想让我们的游戏恢复到它原来的状态。

首先，我们将改变我们的 __init__ 函数如下所示。我们正在将价值设置为类似于 None 、0或类似。此步骤的目的是确保在类上创建属性。在Python中，我们不能将新属性添加到 __init__ 功能。

def __init__(self):

    super().__init__(SCREEN_WIDTH, SCREEN_HEIGHT, SCREEN_TITLE)

    self.player_texture = None
    self.player_sprite = None
    self.player_list = None

    self.wall_list = None

接下来，我们将把这些对象的实际创建移到我们的设置函数中。这个看起来和我们原来的几乎一模一样 __init__ 功能。尝试自己移动这些代码段，如果卡住了，可以看到 setup 函数，请参见下面的完整源代码清单。

我们需要做的最后一件事是创造一种重置游戏的方法。现在，我们将添加一个简单的按键来完成此操作。将以下内容添加到您的 on_key_press 当按下Esc键时重置游戏的功能。

if key == arcade.key.ESCAPE:
    self.setup()

源代码#

正在重置#
  1"""
  2Platformer Game
  3
  4python -m arcade.examples.platform_tutorial.06_reset
  5"""
  6import arcade
  7
  8# Constants
  9SCREEN_WIDTH = 800
 10SCREEN_HEIGHT = 600
 11SCREEN_TITLE = "Platformer"
 12
 13# Constants used to scale our sprites from their original size
 14TILE_SCALING = 0.5
 15
 16# Movement speed of player, in pixels per frame
 17PLAYER_MOVEMENT_SPEED = 5
 18GRAVITY = 1
 19PLAYER_JUMP_SPEED = 20
 20
 21
 22class MyGame(arcade.Window):
 23    """
 24    Main application class.
 25    """
 26
 27    def __init__(self):
 28
 29        # Call the parent class and set up the window
 30        super().__init__(SCREEN_WIDTH, SCREEN_HEIGHT, SCREEN_TITLE)
 31
 32        # Variable to hold our texture for our player
 33        self.player_texture = None
 34
 35        # Separate variable that holds the player sprite
 36        self.player_sprite = None
 37
 38        # SpriteList for our player
 39        self.player_list = None
 40
 41        # SpriteList for our boxes and ground
 42        # Putting our ground and box Sprites in the same SpriteList
 43        # will make it easier to perform collision detection against
 44        # them later on. Setting the spatial hash to True will make
 45        # collision detection much faster if the objects in this
 46        # SpriteList do not move.
 47        self.wall_list = None
 48
 49    def setup(self):
 50        """Set up the game here. Call this function to restart the game."""
 51        self.player_texture = arcade.load_texture(":resources:images/animated_characters/female_adventurer/femaleAdventurer_idle.png")
 52
 53        self.player_sprite = arcade.Sprite(self.player_texture)
 54        self.player_sprite.center_x = 64
 55        self.player_sprite.center_y = 128
 56
 57        self.player_list = arcade.SpriteList()
 58        self.player_list.append(self.player_sprite)
 59
 60        self.wall_list = arcade.SpriteList(use_spatial_hash=True)
 61
 62        # Create the ground
 63        # This shows using a loop to place multiple sprites horizontally
 64        for x in range(0, 1250, 64):
 65            wall = arcade.Sprite(":resources:images/tiles/grassMid.png", scale=TILE_SCALING)
 66            wall.center_x = x
 67            wall.center_y = 32
 68            self.wall_list.append(wall)
 69
 70        # Put some crates on the ground
 71        # This shows using a coordinate list to place sprites
 72        coordinate_list = [[512, 96], [256, 96], [768, 96]]
 73
 74        for coordinate in coordinate_list:
 75            # Add a crate on the ground
 76            wall = arcade.Sprite(
 77                ":resources:images/tiles/boxCrate_double.png", scale=TILE_SCALING
 78            )
 79            wall.position = coordinate
 80            self.wall_list.append(wall)
 81
 82        # Create a Platformer Physics Engine, this will handle moving our
 83        # player as well as collisions between the player sprite and
 84        # whatever SpriteList we specify for the walls.
 85        # It is important to supply static to the walls parameter. There is a
 86        # platforms parameter that is intended for moving platforms.
 87        # If a platform is supposed to move, and is added to the walls list,
 88        # it will not be moved.
 89        self.physics_engine = arcade.PhysicsEnginePlatformer(
 90            self.player_sprite, walls=self.wall_list, gravity_constant=GRAVITY
 91        )
 92
 93        self.background_color = arcade.csscolor.CORNFLOWER_BLUE
 94
 95    def on_draw(self):
 96        """Render the screen."""
 97
 98        # Clear the screen to the background color
 99        self.clear()
100
101        # Draw our sprites
102        self.player_list.draw()
103        self.wall_list.draw()
104
105    def on_update(self, delta_time):
106        """Movement and Game Logic"""
107
108        # Move the player using our physics engine
109        self.physics_engine.update()
110
111    def on_key_press(self, key, modifiers):
112        """Called whenever a key is pressed."""
113
114        if key == arcade.key.ESCAPE:
115            self.setup()
116
117        if key == arcade.key.UP or key == arcade.key.W:
118            if self.physics_engine.can_jump():
119                self.player_sprite.change_y = PLAYER_JUMP_SPEED
120
121        if key == arcade.key.LEFT or key == arcade.key.A:
122            self.player_sprite.change_x = -PLAYER_MOVEMENT_SPEED
123        elif key == arcade.key.RIGHT or key == arcade.key.D:
124            self.player_sprite.change_x = PLAYER_MOVEMENT_SPEED
125
126    def on_key_release(self, key, modifiers):
127        """Called whenever a key is released."""
128
129        if key == arcade.key.LEFT or key == arcade.key.A:
130            self.player_sprite.change_x = 0
131        elif key == arcade.key.RIGHT or key == arcade.key.D:
132            self.player_sprite.change_x = 0
133
134
135def main():
136    """Main function"""
137    window = MyGame()
138    window.setup()
139    arcade.run()
140
141
142if __name__ == "__main__":
143    main()

运行本章#

python -m arcade.examples.platform_tutorial.06_reset