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 we need to define is the size of a sprite in pixels. Along with that we need to know the grid size in pixels. These are used to calculate the end of the level.
TILE_SCALING = 0.5
COIN_SCALING = 0.5
Next we need 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_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"
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.
self.reset_score = True
# 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")
Also in our __init__
function we’ll need a variable to tell us if we need to reset the score. This will be the case
if the player fails the level. However, now that the player can pass a level, we need to keep
the score when calling our setup
function for the new level. Otherwise it will reset
the score back to 0
self.score = 0
# Do we need to reset the score?
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.
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,
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.
self.reset_score = True
# 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_after("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
Next in our setup
function we need to check to see if we need to reset the score or keep it.
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, make sure we keep the score if the player finishes a level
if self.reset_score:
Lastly in our setup
function we need to calculate the end_of_map
value we added earlier in init
.
# --- Load in a map from the tiled editor ---
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, tell our setup
function not to reset the score, and then re-run
the setup
function.
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[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
# Make sure to keep the score from this level when setting up the next level
self.reset_score = False
Note
What else might you want to do?
Bullets (or something you can shoot)
Source Code#
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 | """ Platformer Game python -m arcade.examples.platform_tutorial.10_multiple_levels """ 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 # Do we need to reset the score? self.reset_score = True # 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.""" # 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 = 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, make sure we keep the score if the player finishes a level if self.reset_score: self.score = 0 self.reset_score = True # 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_after("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.width * GRID_PIXEL_SIZE # --- 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, gravity_constant=GRAVITY, 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 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[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[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 # Make sure to keep the score from this level when setting up the next level self.reset_score = False # Load the next level self.setup() # Position the camera self.center_camera_to_player() def main(): """Main function""" window = MyGame() window.setup() arcade.run() if __name__ == "__main__": main() |