Step 13 - Add Enemies

Animate Characters

"""
Platformer Game

python -m arcade.examples.platform_tutorial.13_add_enemies
"""
import math

import arcade

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

# Constants used to scale our sprites from their original size
TILE_SCALING = 0.5
CHARACTER_SCALING = TILE_SCALING * 2
COIN_SCALING = TILE_SCALING
SPRITE_PIXEL_SIZE = 128
GRID_PIXEL_SIZE = SPRITE_PIXEL_SIZE * TILE_SCALING

# Movement speed of player, in pixels per frame
PLAYER_MOVEMENT_SPEED = 7
GRAVITY = 1.5
PLAYER_JUMP_SPEED = 30

PLAYER_START_X = 2
PLAYER_START_Y = 1

# Constants used to track if the player is facing left or right
RIGHT_FACING = 0
LEFT_FACING = 1

LAYER_NAME_MOVING_PLATFORMS = "Moving Platforms"
LAYER_NAME_PLATFORMS = "Platforms"
LAYER_NAME_COINS = "Coins"
LAYER_NAME_BACKGROUND = "Background"
LAYER_NAME_LADDERS = "Ladders"
LAYER_NAME_PLAYER = "Player"
LAYER_NAME_ENEMIES = "Enemies"


def load_texture_pair(filename):
    """
    Load a texture pair, with the second being a mirror image.
    """
    return [
        arcade.load_texture(filename),
        arcade.load_texture(filename, flipped_horizontally=True),
    ]


class Entity(arcade.Sprite):
    def __init__(self, name_folder, name_file):
        super().__init__()

        # Default to facing right
        self.facing_direction = RIGHT_FACING

        # Used for image sequences
        self.cur_texture = 0
        self.scale = CHARACTER_SCALING
        self.character_face_direction = RIGHT_FACING

        main_path = f":resources:images/animated_characters/{name_folder}/{name_file}"

        self.idle_texture_pair = load_texture_pair(f"{main_path}_idle.png")
        self.jump_texture_pair = load_texture_pair(f"{main_path}_jump.png")
        self.fall_texture_pair = load_texture_pair(f"{main_path}_fall.png")

        # Load textures for walking
        self.walk_textures = []
        for i in range(8):
            texture = load_texture_pair(f"{main_path}_walk{i}.png")
            self.walk_textures.append(texture)

        # Load textures for climbing
        self.climbing_textures = []
        texture = arcade.load_texture(f"{main_path}_climb0.png")
        self.climbing_textures.append(texture)
        texture = arcade.load_texture(f"{main_path}_climb1.png")
        self.climbing_textures.append(texture)

        # Set the initial texture
        self.texture = self.idle_texture_pair[0]

        # Hit box will be set based on the first image used. If you want to specify
        # a different hit box, you can do it like the code below.
        # set_hit_box = [[-22, -64], [22, -64], [22, 28], [-22, 28]]
        self.hit_box = self.texture.hit_box_points


class Enemy(Entity):
    def __init__(self, name_folder, name_file):

        # Setup parent class
        super().__init__(name_folder, name_file)


class RobotEnemy(Enemy):
    def __init__(self):

        # Set up parent class
        super().__init__("robot", "robot")


class ZombieEnemy(Enemy):
    def __init__(self):

        # Set up parent class
        super().__init__("zombie", "zombie")


class PlayerCharacter(Entity):
    """Player Sprite"""

    def __init__(self):

        # Set up parent class
        super().__init__("male_person", "malePerson")

        # Track our state
        self.jumping = False
        self.climbing = False
        self.is_on_ladder = False

    def update_animation(self, delta_time: float = 1 / 60):

        # Figure out if we need to flip face left or right
        if self.change_x < 0 and self.facing_direction == RIGHT_FACING:
            self.facing_direction = LEFT_FACING
        elif self.change_x > 0 and self.facing_direction == LEFT_FACING:
            self.facing_direction = RIGHT_FACING

        # Climbing animation
        if self.is_on_ladder:
            self.climbing = True
        if not self.is_on_ladder and self.climbing:
            self.climbing = False
        if self.climbing and abs(self.change_y) > 1:
            self.cur_texture += 1
            if self.cur_texture > 7:
                self.cur_texture = 0
        if self.climbing:
            self.texture = self.climbing_textures[self.cur_texture // 4]
            return

        # Jumping animation
        if self.change_y > 0 and not self.is_on_ladder:
            self.texture = self.jump_texture_pair[self.facing_direction]
            return
        elif self.change_y < 0 and not self.is_on_ladder:
            self.texture = self.fall_texture_pair[self.facing_direction]
            return

        # Idle animation
        if self.change_x == 0:
            self.texture = self.idle_texture_pair[self.facing_direction]
            return

        # Walking animation
        self.cur_texture += 1
        if self.cur_texture > 7:
            self.cur_texture = 0
        self.texture = self.walk_textures[self.cur_texture][self.facing_direction]


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

    def __init__(self):
        """
        Initializer for the game
        """
        # Call the parent class and set up the window
        super().__init__(SCREEN_WIDTH, SCREEN_HEIGHT, SCREEN_TITLE)

        # Track the current state of what key is pressed
        self.left_pressed = False
        self.right_pressed = False
        self.up_pressed = False
        self.down_pressed = False
        self.jump_needs_reset = False

        # Our TileMap Object
        self.tile_map = None

        # 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

        self.end_of_map = 0

        # 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")
        self.game_over = arcade.load_sound(":resources:sounds/gameover1.wav")

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

        # Set up the Cameras
        self.camera = arcade.Camera(self.width, self.height)
        self.gui_camera = arcade.Camera(self.width, self.height)

        # Map name
        map_name = ":resources:tiled_maps/map_with_ladders.json"

        # Layer Specific Options for the Tilemap
        layer_options = {
            LAYER_NAME_PLATFORMS: {
                "use_spatial_hash": True,
            },
            LAYER_NAME_MOVING_PLATFORMS: {
                "use_spatial_hash": False,
            },
            LAYER_NAME_LADDERS: {
                "use_spatial_hash": True,
            },
            LAYER_NAME_COINS: {
                "use_spatial_hash": True,
            },
        }

        # Load in TileMap
        self.tile_map = arcade.load_tilemap(map_name, TILE_SCALING, layer_options)

        # Initiate New Scene with our TileMap, this will automatically add all layers
        # from the map as SpriteLists in the scene in the proper order.
        self.scene = arcade.Scene.from_tilemap(self.tile_map)

        # Keep track of the score
        self.score = 0

        # Set up the player, specifically placing it at these coordinates.
        self.player_sprite = PlayerCharacter()
        self.player_sprite.center_x = (
            self.tile_map.tile_width * TILE_SCALING * PLAYER_START_X
        )
        self.player_sprite.center_y = (
            self.tile_map.tile_height * TILE_SCALING * PLAYER_START_Y
        )
        self.scene.add_sprite(LAYER_NAME_PLAYER, self.player_sprite)

        # Calculate the right edge of the my_map in pixels
        self.end_of_map = self.tile_map.width * GRID_PIXEL_SIZE

        # -- Enemies
        enemies_layer = self.tile_map.object_lists[LAYER_NAME_ENEMIES]

        for my_object in enemies_layer:
            cartesian = self.tile_map.get_cartesian(
                my_object.shape[0], my_object.shape[1]
            )
            enemy_type = my_object.properties["type"]
            if enemy_type == "robot":
                enemy = RobotEnemy()
            elif enemy_type == "zombie":
                enemy = ZombieEnemy()
            else:
                raise Exception(f"Unknown enemy type {enemy_type}.")
            enemy.center_x = math.floor(
                cartesian[0] * TILE_SCALING * self.tile_map.tile_width
            )
            enemy.center_y = math.floor(
                (cartesian[1] + 1) * (self.tile_map.tile_height * TILE_SCALING)
            )
            self.scene.add_sprite(LAYER_NAME_ENEMIES, enemy)

        # --- Other stuff
        # Set the background color
        if self.tile_map.background_color:
            arcade.set_background_color(self.tile_map.background_color)

        # Create the 'physics engine'
        self.physics_engine = arcade.PhysicsEnginePlatformer(
            self.player_sprite,
            platforms=self.scene[LAYER_NAME_MOVING_PLATFORMS],
            gravity_constant=GRAVITY,
            ladders=self.scene[LAYER_NAME_LADDERS],
            walls=self.scene[LAYER_NAME_PLATFORMS]
        )

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

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

        # 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.BLACK,
            18,
        )

    def process_keychange(self):
        """
        Called when we change a key up/down or we move on/off a ladder.
        """
        # Process up/down
        if self.up_pressed and not self.down_pressed:
            if self.physics_engine.is_on_ladder():
                self.player_sprite.change_y = PLAYER_MOVEMENT_SPEED
            elif (
                self.physics_engine.can_jump(y_distance=10)
                and not self.jump_needs_reset
            ):
                self.player_sprite.change_y = PLAYER_JUMP_SPEED
                self.jump_needs_reset = True
                arcade.play_sound(self.jump_sound)
        elif self.down_pressed and not self.up_pressed:
            if self.physics_engine.is_on_ladder():
                self.player_sprite.change_y = -PLAYER_MOVEMENT_SPEED

        # Process up/down when on a ladder and no movement
        if self.physics_engine.is_on_ladder():
            if not self.up_pressed and not self.down_pressed:
                self.player_sprite.change_y = 0
            elif self.up_pressed and self.down_pressed:
                self.player_sprite.change_y = 0

        # Process left/right
        if self.right_pressed and not self.left_pressed:
            self.player_sprite.change_x = PLAYER_MOVEMENT_SPEED
        elif self.left_pressed and not self.right_pressed:
            self.player_sprite.change_x = -PLAYER_MOVEMENT_SPEED
        else:
            self.player_sprite.change_x = 0

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

        if key == arcade.key.UP or key == arcade.key.W:
            self.up_pressed = True
        elif key == arcade.key.DOWN or key == arcade.key.S:
            self.down_pressed = True
        elif key == arcade.key.LEFT or key == arcade.key.A:
            self.left_pressed = True
        elif key == arcade.key.RIGHT or key == arcade.key.D:
            self.right_pressed = True

        self.process_keychange()

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

        if key == arcade.key.UP or key == arcade.key.W:
            self.up_pressed = False
            self.jump_needs_reset = False
        elif key == arcade.key.DOWN or key == arcade.key.S:
            self.down_pressed = False
        elif key == arcade.key.LEFT or key == arcade.key.A:
            self.left_pressed = False
        elif key == arcade.key.RIGHT or key == arcade.key.D:
            self.right_pressed = False

        self.process_keychange()

    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, 0.2)

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

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

        # Update animations
        if self.physics_engine.can_jump():
            self.player_sprite.can_jump = False
        else:
            self.player_sprite.can_jump = True

        if self.physics_engine.is_on_ladder() and not self.physics_engine.can_jump():
            self.player_sprite.is_on_ladder = True
            self.process_keychange()
        else:
            self.player_sprite.is_on_ladder = False
            self.process_keychange()

        # Update Animations
        self.scene.update_animation(
            delta_time,
            [
                LAYER_NAME_COINS,
                LAYER_NAME_BACKGROUND,
                LAYER_NAME_PLAYER,
                LAYER_NAME_ENEMIES,
            ],
        )

        # Update walls, used with moving platforms
        self.scene.update([LAYER_NAME_MOVING_PLATFORMS])

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

        # Loop through each coin we hit (if any) and remove it
        for coin in coin_hit_list:

            # Figure out how many points this coin is worth
            if "Points" not in coin.properties:
                print("Warning, collected a coin without a Points property.")
            else:
                points = int(coin.properties["Points"])
                self.score += points

            # Remove the coin
            coin.remove_from_sprite_lists()
            arcade.play_sound(self.collect_coin_sound)

        # Position the camera
        self.center_camera_to_player()


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


if __name__ == "__main__":
    main()

Source Code

Add Enemies

"""
Platformer Game

python -m arcade.examples.platform_tutorial.13_add_enemies
"""
import math

import arcade

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

# Constants used to scale our sprites from their original size
TILE_SCALING = 0.5
CHARACTER_SCALING = TILE_SCALING * 2
COIN_SCALING = TILE_SCALING
SPRITE_PIXEL_SIZE = 128
GRID_PIXEL_SIZE = SPRITE_PIXEL_SIZE * TILE_SCALING

# Movement speed of player, in pixels per frame
PLAYER_MOVEMENT_SPEED = 7
GRAVITY = 1.5
PLAYER_JUMP_SPEED = 30

PLAYER_START_X = 2
PLAYER_START_Y = 1

# Constants used to track if the player is facing left or right
RIGHT_FACING = 0
LEFT_FACING = 1

LAYER_NAME_MOVING_PLATFORMS = "Moving Platforms"
LAYER_NAME_PLATFORMS = "Platforms"
LAYER_NAME_COINS = "Coins"
LAYER_NAME_BACKGROUND = "Background"
LAYER_NAME_LADDERS = "Ladders"
LAYER_NAME_PLAYER = "Player"
LAYER_NAME_ENEMIES = "Enemies"


def load_texture_pair(filename):
    """
    Load a texture pair, with the second being a mirror image.
    """
    return [
        arcade.load_texture(filename),
        arcade.load_texture(filename, flipped_horizontally=True),
    ]


class Entity(arcade.Sprite):
    def __init__(self, name_folder, name_file):
        super().__init__()

        # Default to facing right
        self.facing_direction = RIGHT_FACING

        # Used for image sequences
        self.cur_texture = 0
        self.scale = CHARACTER_SCALING
        self.character_face_direction = RIGHT_FACING

        main_path = f":resources:images/animated_characters/{name_folder}/{name_file}"

        self.idle_texture_pair = load_texture_pair(f"{main_path}_idle.png")
        self.jump_texture_pair = load_texture_pair(f"{main_path}_jump.png")
        self.fall_texture_pair = load_texture_pair(f"{main_path}_fall.png")

        # Load textures for walking
        self.walk_textures = []
        for i in range(8):
            texture = load_texture_pair(f"{main_path}_walk{i}.png")
            self.walk_textures.append(texture)

        # Load textures for climbing
        self.climbing_textures = []
        texture = arcade.load_texture(f"{main_path}_climb0.png")
        self.climbing_textures.append(texture)
        texture = arcade.load_texture(f"{main_path}_climb1.png")
        self.climbing_textures.append(texture)

        # Set the initial texture
        self.texture = self.idle_texture_pair[0]

        # Hit box will be set based on the first image used. If you want to specify
        # a different hit box, you can do it like the code below.
        # set_hit_box = [[-22, -64], [22, -64], [22, 28], [-22, 28]]
        self.hit_box = self.texture.hit_box_points


class Enemy(Entity):
    def __init__(self, name_folder, name_file):

        # Setup parent class
        super().__init__(name_folder, name_file)


class RobotEnemy(Enemy):
    def __init__(self):

        # Set up parent class
        super().__init__("robot", "robot")


class ZombieEnemy(Enemy):
    def __init__(self):

        # Set up parent class
        super().__init__("zombie", "zombie")


class PlayerCharacter(Entity):
    """Player Sprite"""

    def __init__(self):

        # Set up parent class
        super().__init__("male_person", "malePerson")

        # Track our state
        self.jumping = False
        self.climbing = False
        self.is_on_ladder = False

    def update_animation(self, delta_time: float = 1 / 60):

        # Figure out if we need to flip face left or right
        if self.change_x < 0 and self.facing_direction == RIGHT_FACING:
            self.facing_direction = LEFT_FACING
        elif self.change_x > 0 and self.facing_direction == LEFT_FACING:
            self.facing_direction = RIGHT_FACING

        # Climbing animation
        if self.is_on_ladder:
            self.climbing = True
        if not self.is_on_ladder and self.climbing:
            self.climbing = False
        if self.climbing and abs(self.change_y) > 1:
            self.cur_texture += 1
            if self.cur_texture > 7:
                self.cur_texture = 0
        if self.climbing:
            self.texture = self.climbing_textures[self.cur_texture // 4]
            return

        # Jumping animation
        if self.change_y > 0 and not self.is_on_ladder:
            self.texture = self.jump_texture_pair[self.facing_direction]
            return
        elif self.change_y < 0 and not self.is_on_ladder:
            self.texture = self.fall_texture_pair[self.facing_direction]
            return

        # Idle animation
        if self.change_x == 0:
            self.texture = self.idle_texture_pair[self.facing_direction]
            return

        # Walking animation
        self.cur_texture += 1
        if self.cur_texture > 7:
            self.cur_texture = 0
        self.texture = self.walk_textures[self.cur_texture][self.facing_direction]


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

    def __init__(self):
        """
        Initializer for the game
        """
        # Call the parent class and set up the window
        super().__init__(SCREEN_WIDTH, SCREEN_HEIGHT, SCREEN_TITLE)

        # Track the current state of what key is pressed
        self.left_pressed = False
        self.right_pressed = False
        self.up_pressed = False
        self.down_pressed = False
        self.jump_needs_reset = False

        # Our TileMap Object
        self.tile_map = None

        # 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

        self.end_of_map = 0

        # 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")
        self.game_over = arcade.load_sound(":resources:sounds/gameover1.wav")

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

        # Set up the Cameras
        self.camera = arcade.Camera(self.width, self.height)
        self.gui_camera = arcade.Camera(self.width, self.height)

        # Map name
        map_name = ":resources:tiled_maps/map_with_ladders.json"

        # Layer Specific Options for the Tilemap
        layer_options = {
            LAYER_NAME_PLATFORMS: {
                "use_spatial_hash": True,
            },
            LAYER_NAME_MOVING_PLATFORMS: {
                "use_spatial_hash": False,
            },
            LAYER_NAME_LADDERS: {
                "use_spatial_hash": True,
            },
            LAYER_NAME_COINS: {
                "use_spatial_hash": True,
            },
        }

        # Load in TileMap
        self.tile_map = arcade.load_tilemap(map_name, TILE_SCALING, layer_options)

        # Initiate New Scene with our TileMap, this will automatically add all layers
        # from the map as SpriteLists in the scene in the proper order.
        self.scene = arcade.Scene.from_tilemap(self.tile_map)

        # Keep track of the score
        self.score = 0

        # Set up the player, specifically placing it at these coordinates.
        self.player_sprite = PlayerCharacter()
        self.player_sprite.center_x = (
            self.tile_map.tile_width * TILE_SCALING * PLAYER_START_X
        )
        self.player_sprite.center_y = (
            self.tile_map.tile_height * TILE_SCALING * PLAYER_START_Y
        )
        self.scene.add_sprite(LAYER_NAME_PLAYER, self.player_sprite)

        # Calculate the right edge of the my_map in pixels
        self.end_of_map = self.tile_map.width * GRID_PIXEL_SIZE

        # -- Enemies
        enemies_layer = self.tile_map.object_lists[LAYER_NAME_ENEMIES]

        for my_object in enemies_layer:
            cartesian = self.tile_map.get_cartesian(
                my_object.shape[0], my_object.shape[1]
            )
            enemy_type = my_object.properties["type"]
            if enemy_type == "robot":
                enemy = RobotEnemy()
            elif enemy_type == "zombie":
                enemy = ZombieEnemy()
            else:
                raise Exception(f"Unknown enemy type {enemy_type}.")
            enemy.center_x = math.floor(
                cartesian[0] * TILE_SCALING * self.tile_map.tile_width
            )
            enemy.center_y = math.floor(
                (cartesian[1] + 1) * (self.tile_map.tile_height * TILE_SCALING)
            )
            self.scene.add_sprite(LAYER_NAME_ENEMIES, enemy)

        # --- Other stuff
        # Set the background color
        if self.tile_map.background_color:
            arcade.set_background_color(self.tile_map.background_color)

        # Create the 'physics engine'
        self.physics_engine = arcade.PhysicsEnginePlatformer(
            self.player_sprite,
            platforms=self.scene[LAYER_NAME_MOVING_PLATFORMS],
            gravity_constant=GRAVITY,
            ladders=self.scene[LAYER_NAME_LADDERS],
            walls=self.scene[LAYER_NAME_PLATFORMS]
        )

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

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

        # 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.BLACK,
            18,
        )

    def process_keychange(self):
        """
        Called when we change a key up/down or we move on/off a ladder.
        """
        # Process up/down
        if self.up_pressed and not self.down_pressed:
            if self.physics_engine.is_on_ladder():
                self.player_sprite.change_y = PLAYER_MOVEMENT_SPEED
            elif (
                self.physics_engine.can_jump(y_distance=10)
                and not self.jump_needs_reset
            ):
                self.player_sprite.change_y = PLAYER_JUMP_SPEED
                self.jump_needs_reset = True
                arcade.play_sound(self.jump_sound)
        elif self.down_pressed and not self.up_pressed:
            if self.physics_engine.is_on_ladder():
                self.player_sprite.change_y = -PLAYER_MOVEMENT_SPEED

        # Process up/down when on a ladder and no movement
        if self.physics_engine.is_on_ladder():
            if not self.up_pressed and not self.down_pressed:
                self.player_sprite.change_y = 0
            elif self.up_pressed and self.down_pressed:
                self.player_sprite.change_y = 0

        # Process left/right
        if self.right_pressed and not self.left_pressed:
            self.player_sprite.change_x = PLAYER_MOVEMENT_SPEED
        elif self.left_pressed and not self.right_pressed:
            self.player_sprite.change_x = -PLAYER_MOVEMENT_SPEED
        else:
            self.player_sprite.change_x = 0

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

        if key == arcade.key.UP or key == arcade.key.W:
            self.up_pressed = True
        elif key == arcade.key.DOWN or key == arcade.key.S:
            self.down_pressed = True
        elif key == arcade.key.LEFT or key == arcade.key.A:
            self.left_pressed = True
        elif key == arcade.key.RIGHT or key == arcade.key.D:
            self.right_pressed = True

        self.process_keychange()

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

        if key == arcade.key.UP or key == arcade.key.W:
            self.up_pressed = False
            self.jump_needs_reset = False
        elif key == arcade.key.DOWN or key == arcade.key.S:
            self.down_pressed = False
        elif key == arcade.key.LEFT or key == arcade.key.A:
            self.left_pressed = False
        elif key == arcade.key.RIGHT or key == arcade.key.D:
            self.right_pressed = False

        self.process_keychange()

    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, 0.2)

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

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

        # Update animations
        if self.physics_engine.can_jump():
            self.player_sprite.can_jump = False
        else:
            self.player_sprite.can_jump = True

        if self.physics_engine.is_on_ladder() and not self.physics_engine.can_jump():
            self.player_sprite.is_on_ladder = True
            self.process_keychange()
        else:
            self.player_sprite.is_on_ladder = False
            self.process_keychange()

        # Update Animations
        self.scene.update_animation(
            delta_time,
            [
                LAYER_NAME_COINS,
                LAYER_NAME_BACKGROUND,
                LAYER_NAME_PLAYER,
                LAYER_NAME_ENEMIES,
            ],
        )

        # Update walls, used with moving platforms
        self.scene.update([LAYER_NAME_MOVING_PLATFORMS])

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

        # Loop through each coin we hit (if any) and remove it
        for coin in coin_hit_list:

            # Figure out how many points this coin is worth
            if "Points" not in coin.properties:
                print("Warning, collected a coin without a Points property.")
            else:
                points = int(coin.properties["Points"])
                self.score += points

            # Remove the coin
            coin.remove_from_sprite_lists()
            arcade.play_sound(self.collect_coin_sound)

        # Position the camera
        self.center_camera_to_player()


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


if __name__ == "__main__":
    main()