Step 10 - Multiple Levels and Other Layers¶
Now that we’ve seen the basics of loading a Tiled map, we’ll give another example with some more features. In this example we’ll add the following things:
New layers including foreground, background, and “Don’t Touch”
The background layer will appear behind the player
The foreground layer will appear in front of the player
The Don’t Touch layer will cause the player to be reset to the start
The player resets to the start if they fall off the map
If the player gets to the right side of the map, the program attempts to load the next map
This is achieved by naming the maps with incrementing numbers, something like “map_01.json”, “map_02.json”, etc. Then having a level attribute to track which number we’re on and increasing it and re-running the setup function.
To start things off, let’s add a few constants at the top of our game. The first one to define a starting position for the player, and then since we’re starting to have a larger number of layers in our game, it will be best to store their names in variables in case we need to change them later.
# Player starting position
PLAYER_START_X = 64
PLAYER_START_Y = 225
# Layer Names from our TileMap
LAYER_NAME_PLATFORMS = "Platforms"
LAYER_NAME_COINS = "Coins"
LAYER_NAME_FOREGROUND = "Foreground"
LAYER_NAME_BACKGROUND = "Background"
LAYER_NAME_DONT_TOUCH = "Don't Touch"
Then in the __init__
function we’ll add two new values. One to know where the right
edge of the map is, and one to keep track of what level we’re on, and add a new game over sound.
# Where is the right edge of the map?
self.end_of_map = 0
# Level
self.level = 1
# 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")
Then in our setup
function we’ll change up our map name variable to use that new level attribute,
and add some extra layer specific options for the new layers we’ve added to our map.
# Map name
map_name = f":resources:tiled_maps/map2_level_{self.level}.json"
# Layer Specific Options for the Tilemap
layer_options = {
LAYER_NAME_PLATFORMS: {
"use_spatial_hash": True,
},
LAYER_NAME_COINS: {
"use_spatial_hash": True,
},
LAYER_NAME_DONT_TOUCH: {
"use_spatial_hash": True,
},
}
Now in order to make our player appear behind the “Foreground” layer, we need to add a line in our
setup
function before we create the player Sprite. This will basically be telling our Scene where
in the render order we want to place the player. Previously we haven’t defined this, and so it’s always
just been added to the end of the render order.
# Add Player Spritelist before "Foreground" layer. This will make the foreground
# be drawn after the player, making it appear to be in front of the Player.
# Setting before using scene.add_sprite allows us to define where the SpriteList
# will be in the draw order. If we just use add_sprite, it will be appended to the
# end of the order.
self.scene.add_sprite_list_before("Player", LAYER_NAME_FOREGROUND)
# 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 = PLAYER_START_X
self.player_sprite.center_y = PLAYER_START_Y
self.scene.add_sprite("Player", self.player_sprite)
Lastly in our setup
function we need to calculate the end_of_map
value we added earlier in init
.
# Calculate the right edge of the my_map in pixels
self.end_of_map = self.tile_map.tiled_map.map_size.width * GRID_PIXEL_SIZE
The on_draw
, on_key_press
, and on_key_release
functions will be unchanged for this section, so the
last thing to do is add a few things to the on_update
function. First we check if the player has fallen off
of the map, and if so, we move them back to the starting position. Then we check if they collided with something
from the “Don’t Touch” layer, and if so reset them to the start. Lastly we check if they’ve reached the end of the
map, and if they have we increment the level value and re-run the setup function.
# Did the player fall off the map?
if self.player_sprite.center_y < -100:
self.player_sprite.center_x = PLAYER_START_X
self.player_sprite.center_y = PLAYER_START_Y
arcade.play_sound(self.game_over)
# Did the player touch something they should not?
if arcade.check_for_collision_with_list(
self.player_sprite, self.scene.get_sprite_list(LAYER_NAME_DONT_TOUCH)
):
self.player_sprite.change_x = 0
self.player_sprite.change_y = 0
self.player_sprite.center_x = PLAYER_START_X
self.player_sprite.center_y = PLAYER_START_Y
arcade.play_sound(self.game_over)
# See if the user got to the end of the level
if self.player_sprite.center_x >= self.end_of_map:
# Advance to the next level
self.level += 1
# Load the next level
self.setup()
Note
What else might you want to do?
Bullets (or something you can shoot)
Source Code¶
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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
SPRITE_PIXEL_SIZE = 128
GRID_PIXEL_SIZE = SPRITE_PIXEL_SIZE * TILE_SCALING
# Movement speed of player, in pixels per frame
PLAYER_MOVEMENT_SPEED = 10
GRAVITY = 1
PLAYER_JUMP_SPEED = 20
# Player starting position
PLAYER_START_X = 64
PLAYER_START_Y = 225
# Layer Names from our TileMap
LAYER_NAME_PLATFORMS = "Platforms"
LAYER_NAME_COINS = "Coins"
LAYER_NAME_FOREGROUND = "Foreground"
LAYER_NAME_BACKGROUND = "Background"
LAYER_NAME_DONT_TOUCH = "Don't Touch"
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 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
# Keep track of the score
self.score = 0
# Where is the right edge of the map?
self.end_of_map = 0
# Level
self.level = 1
# 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."""
# Setup the Cameras
self.camera = arcade.Camera(self.width, self.height)
self.gui_camera = arcade.Camera(self.width, self.height)
# Map name
map_name = f":resources:tiled_maps/map2_level_{self.level}.json"
# Layer Specific Options for the Tilemap
layer_options = {
LAYER_NAME_PLATFORMS: {
"use_spatial_hash": True,
},
LAYER_NAME_COINS: {
"use_spatial_hash": True,
},
LAYER_NAME_DONT_TOUCH: {
"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
# Add Player Spritelist before "Foreground" layer. This will make the foreground
# be drawn after the player, making it appear to be in front of the Player.
# Setting before using scene.add_sprite allows us to define where the SpriteList
# will be in the draw order. If we just use add_sprite, it will be appended to the
# end of the order.
self.scene.add_sprite_list_before("Player", LAYER_NAME_FOREGROUND)
# 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 = PLAYER_START_X
self.player_sprite.center_y = PLAYER_START_Y
self.scene.add_sprite("Player", self.player_sprite)
# --- Load in a map from the tiled editor ---
# Calculate the right edge of the my_map in pixels
self.end_of_map = self.tile_map.tiled_map.map_size.width * GRID_PIXEL_SIZE
# --- Other stuff
# Set the background color
if self.tile_map.tiled_map.background_color:
arcade.set_background_color(self.tile_map.tiled_map.background_color)
# Create the 'physics engine'
self.physics_engine = arcade.PhysicsEnginePlatformer(
self.player_sprite,
self.scene.get_sprite_list(LAYER_NAME_PLATFORMS),
GRAVITY,
)
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.BLACK,
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 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.get_sprite_list(LAYER_NAME_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
# Did the player fall off the map?
if self.player_sprite.center_y < -100:
self.player_sprite.center_x = PLAYER_START_X
self.player_sprite.center_y = PLAYER_START_Y
arcade.play_sound(self.game_over)
# Did the player touch something they should not?
if arcade.check_for_collision_with_list(
self.player_sprite, self.scene.get_sprite_list(LAYER_NAME_DONT_TOUCH)
):
self.player_sprite.change_x = 0
self.player_sprite.change_y = 0
self.player_sprite.center_x = PLAYER_START_X
self.player_sprite.center_y = PLAYER_START_Y
arcade.play_sound(self.game_over)
# See if the user got to the end of the level
if self.player_sprite.center_x >= self.end_of_map:
# Advance to the next level
self.level += 1
# Load the next level
self.setup()
# Position the camera
self.center_camera_to_player()
def main():
"""Main method"""
window = MyGame()
window.setup()
arcade.run()
if __name__ == "__main__":
main()
|