第3步-场景对象#

接下来，我们将在游戏中添加一个场景。场景是一种通过为每个SpriteList指定名称并维护绘制顺序来管理多个不同SpriteList的工具。

SpriteList可以像我们在本教程的步骤2中看到的那样直接绘制，但是一个场景可以帮助您同时处理许多不同的列表，并且能够通过一个场景调用来绘制所有这些列表。

首先，我们将从 __init__ 函数，并用场景对象替换它们。

03_场景_对象.py-场景对象定义#
    def __init__(self):

        # Call the parent class and set up the window
        super().__init__(SCREEN_WIDTH, SCREEN_HEIGHT, SCREEN_TITLE)

        # Our Scene Object
        self.scene = None

        # Separate variable that holds the player sprite
        self.player_sprite = None

        arcade.set_background_color(arcade.csscolor.CORNFLOWER_BLUE)

接下来，我们将在 setup 函数，然后向其中添加SpriteList，而不是直接创建新的SpriteList对象。

然后，我们可以将Sprite添加到场景中，并按名称指定要将它们添加到的SpriteList，而不是直接将Sprite附加到SpriteList。

03_Scene_object.py-将SpriteList添加到场景#
    def setup(self):
        """Set up the game here. Call this function to restart the game."""

        # Initialize Scene
        self.scene = arcade.Scene()

        # Create the Sprite lists
        self.scene.add_sprite_list("Player")
        self.scene.add_sprite_list("Walls", use_spatial_hash=True)

        # Set up the player, specifically placing it at these coordinates.
        image_source = ":resources:images/animated_characters/female_adventurer/femaleAdventurer_idle.png"
        self.player_sprite = arcade.Sprite(image_source, CHARACTER_SCALING)
        self.player_sprite.center_x = 64
        self.player_sprite.center_y = 128
        self.scene.add_sprite("Player", self.player_sprite)

        # Create the ground
        # This shows using a loop to place multiple sprites horizontally
        for x in range(0, 1250, 64):
            wall = arcade.Sprite(":resources:images/tiles/grassMid.png", TILE_SCALING)
            wall.center_x = x
            wall.center_y = 32
            self.scene.add_sprite("Walls", wall)

        # Put some crates on the ground
        # This shows using a coordinate list to place sprites
        coordinate_list = [[512, 96], [256, 96], [768, 96]]

        for coordinate in coordinate_list:
            # Add a crate on the ground
            wall = arcade.Sprite(
                ":resources:images/tiles/boxCrate_double.png", TILE_SCALING
            )
            wall.position = coordinate
            self.scene.add_sprite("Walls", wall)

最后，在我们的 on_draw 函数，我们可以画出场景。

03_SCENCE_OBJECT.py-绘制场景#
    def on_draw(self):
        """Render the screen."""

        # Clear the screen to the background color
        self.clear()

        # Draw our Scene
        self.scene.draw()

源代码#

03_场景_对象-场景对象#
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"""
Platformer Game
"""
import arcade

# Constants
SCREEN_WIDTH = 1000
SCREEN_HEIGHT = 650
SCREEN_TITLE = "Platformer"

# Constants used to scale our sprites from their original size
CHARACTER_SCALING = 1
TILE_SCALING = 0.5


class MyGame(arcade.Window):
    """
    Main application class.
    """

    def __init__(self):

        # Call the parent class and set up the window
        super().__init__(SCREEN_WIDTH, SCREEN_HEIGHT, SCREEN_TITLE)

        # Our Scene Object
        self.scene = None

        # Separate variable that holds the player sprite
        self.player_sprite = None

        arcade.set_background_color(arcade.csscolor.CORNFLOWER_BLUE)

    def setup(self):
        """Set up the game here. Call this function to restart the game."""

        # Initialize Scene
        self.scene = arcade.Scene()

        # Create the Sprite lists
        self.scene.add_sprite_list("Player")
        self.scene.add_sprite_list("Walls", use_spatial_hash=True)

        # Set up the player, specifically placing it at these coordinates.
        image_source = ":resources:images/animated_characters/female_adventurer/femaleAdventurer_idle.png"
        self.player_sprite = arcade.Sprite(image_source, CHARACTER_SCALING)
        self.player_sprite.center_x = 64
        self.player_sprite.center_y = 128
        self.scene.add_sprite("Player", self.player_sprite)

        # Create the ground
        # This shows using a loop to place multiple sprites horizontally
        for x in range(0, 1250, 64):
            wall = arcade.Sprite(":resources:images/tiles/grassMid.png", TILE_SCALING)
            wall.center_x = x
            wall.center_y = 32
            self.scene.add_sprite("Walls", wall)

        # Put some crates on the ground
        # This shows using a coordinate list to place sprites
        coordinate_list = [[512, 96], [256, 96], [768, 96]]

        for coordinate in coordinate_list:
            # Add a crate on the ground
            wall = arcade.Sprite(
                ":resources:images/tiles/boxCrate_double.png", TILE_SCALING
            )
            wall.position = coordinate
            self.scene.add_sprite("Walls", wall)

    def on_draw(self):
        """Render the screen."""

        # Clear the screen to the background color
        self.clear()

        # Draw our Scene
        self.scene.draw()


def main():
    """Main function"""
    window = MyGame()
    window.setup()
    arcade.run()


if __name__ == "__main__":
    main()