Step 8 - Display The Score

Now that we can collect coins and get points, we need a way to display the score on the screen.

This process is a little bit more complex than just drawing some text at an X and Y location. For properly drawing text, or any GUI elements, we need to use a separate camera than the one we use to draw the rest of our scene.

This is because we are scrolling around the main game camera, but we want our GUI elements to stay still. Using a second camera lets us do this.

As an example, if we were not to use a second camera, and instead draw on the same camera as our scene. We would need to offset the position that we draw our text at by position of the camera. This might be easier if you’re only displaying one thing, but if you have a lot of GUI elements this could get out of hand.

First start by creating the new GUI camera and the score variables in the __init__ function.

Display The Score - The init method
        # A Camera that can be used to draw GUI elements
        self.gui_camera = None

        # Keep track of the score
        self.score = 0

Then we can initialize them in the setup function. We reset the score to 0 here because this function is intended to fully reset the game back to it’s starting state.

Display The Score - The setup method
        # Setup the GUI Camera
        self.gui_camera = arcade.Camera(self.width, self.height)

        # Keep track of the score
        self.score = 0

Then in our on_draw function we can first draw our scene like normal, and then switch to the GUI camera, and then finally draw our text.

Display The Score - The on_draw method
    def on_draw(self):
        """Render the screen."""

        # Clear the screen to the background color
        arcade.start_render()

        # Activate the game camera
        self.camera.use()

        # Draw our Scene
        self.scene.draw()

        # Activate the GUI camera before drawing GUI elements
        self.gui_camera.use()

        # Draw our score on the screen, scrolling it with the viewport
        score_text = f"Score: {self.score}"
        arcade.draw_text(
            score_text,
            10,
            10,
            arcade.csscolor.WHITE,
            18,
        )

Lastly in the on_update function we just need to update the score when a player collects a coin:

Display The Score - The on_update method
        # Loop through each coin we hit (if any) and remove it
        for coin in coin_hit_list:
            # Remove the coin
            coin.remove_from_sprite_lists()
            # Play a sound
            arcade.play_sound(self.collect_coin_sound)
            # Add one to the score
            self.score += 1

Note

You might also want to add:

Source Code

Display The Score
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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
COIN_SCALING = 0.5

# Movement speed of player, in pixels per frame
PLAYER_MOVEMENT_SPEED = 5
GRAVITY = 1
PLAYER_JUMP_SPEED = 20


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

        # Our physics engine
        self.physics_engine = None

        # A Camera that can be used for scrolling the screen
        self.camera = None

        # A Camera that can be used to draw GUI elements
        self.gui_camera = None

        # Keep track of the score
        self.score = 0

        # Load sounds
        self.collect_coin_sound = arcade.load_sound(":resources:sounds/coin1.wav")
        self.jump_sound = arcade.load_sound(":resources:sounds/jump1.wav")

        arcade.set_background_color(arcade.csscolor.CORNFLOWER_BLUE)

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

        # Setup the Game Camera
        self.camera = arcade.Camera(self.width, self.height)

        # Setup the GUI Camera
        self.gui_camera = arcade.Camera(self.width, self.height)

        # Keep track of the score
        self.score = 0

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

        # 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 = 96
        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)

        # Use a loop to place some coins for our character to pick up
        for x in range(128, 1250, 256):
            coin = arcade.Sprite(":resources:images/items/coinGold.png", COIN_SCALING)
            coin.center_x = x
            coin.center_y = 96
            self.scene.add_sprite("Coins", coin)

        # Create the 'physics engine'
        self.physics_engine = arcade.PhysicsEnginePlatformer(
            self.player_sprite, gravity_constant=GRAVITY, walls=self.scene["Walls"]
        )

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

        # Clear the screen to the background color
        arcade.start_render()

        # Activate the game camera
        self.camera.use()

        # Draw our Scene
        self.scene.draw()

        # Activate the GUI camera before drawing GUI elements
        self.gui_camera.use()

        # Draw our score on the screen, scrolling it with the viewport
        score_text = f"Score: {self.score}"
        arcade.draw_text(
            score_text,
            10,
            10,
            arcade.csscolor.WHITE,
            18,
        )

    def on_key_press(self, key, modifiers):
        """Called whenever a key is pressed."""

        if key == arcade.key.UP or key == arcade.key.W:
            if self.physics_engine.can_jump():
                self.player_sprite.change_y = PLAYER_JUMP_SPEED
                arcade.play_sound(self.jump_sound)
        elif key == arcade.key.LEFT or key == arcade.key.A:
            self.player_sprite.change_x = -PLAYER_MOVEMENT_SPEED
        elif key == arcade.key.RIGHT or key == arcade.key.D:
            self.player_sprite.change_x = PLAYER_MOVEMENT_SPEED

    def on_key_release(self, key, modifiers):
        """Called when the user releases a key."""

        if key == arcade.key.LEFT or key == arcade.key.A:
            self.player_sprite.change_x = 0
        elif key == arcade.key.RIGHT or key == arcade.key.D:
            self.player_sprite.change_x = 0

    def center_camera_to_player(self):
        screen_center_x = self.player_sprite.center_x - (self.camera.viewport_width / 2)
        screen_center_y = self.player_sprite.center_y - (
            self.camera.viewport_height / 2
        )
        if screen_center_x < 0:
            screen_center_x = 0
        if screen_center_y < 0:
            screen_center_y = 0
        player_centered = screen_center_x, screen_center_y

        self.camera.move_to(player_centered)

    def on_update(self, delta_time):
        """Movement and game logic"""

        # Move the player with the physics engine
        self.physics_engine.update()

        # See if we hit any coins
        coin_hit_list = arcade.check_for_collision_with_list(
            self.player_sprite, self.scene["Coins"]
        )

        # Loop through each coin we hit (if any) and remove it
        for coin in coin_hit_list:
            # Remove the coin
            coin.remove_from_sprite_lists()
            # Play a sound
            arcade.play_sound(self.collect_coin_sound)
            # Add one to the score
            self.score += 1

        # Position the camera
        self.center_camera_to_player()


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


if __name__ == "__main__":
    main()