Platformer Template

Quickly get started creating your own platformer!

Screenshot of platformer template

About This Template

This is a template to get you started coding a side-scrolling platformer as quickly as possible. I recommend the following steps:

  1. Create a folder to hold the code. Copy this example to that folder, and call it main.py.

  2. Make sure the example code runs fine.

  3. Copy the tile images you want to use to a subdirectory of the folder that holds your code.

  4. Create a very simple Tiled Map using the Tiled Map Editor. I suggest just creating a floor and nothing else. For more detail on how to create a tiled map, see Step 9 - Adding Sound.

  5. Save the file to the same directory as your source code. If you create a separate tileset, also save it to the same directory as your code.

  6. Update the code to load your file instead of the map.

  7. Test and make sure it works.

  8. Now that you are sure things work, make your own platformer!

Warning

Watch the directories!

One of the most frequent mistakes is to save maps and tile sets to a directory that isn’t the same directory as your code. Or to not have the tile images in that folder. If everything isn’t in the same folder (or a subfolder of that) it is hard to package it up later.

For more detailed instructions, see the tutorial Simple Platformer.

Source Code

template_platformer.py
  1"""
  2Platformer Template
  3
  4If Python and Arcade are installed, this example can be run from the command line with:
  5python -m arcade.examples.template_platformer
  6"""
  7import arcade
  8
  9# --- Constants
 10SCREEN_TITLE = "Platformer"
 11
 12SCREEN_WIDTH = 1000
 13SCREEN_HEIGHT = 650
 14
 15# Constants used to scale our sprites from their original size
 16CHARACTER_SCALING = 1
 17TILE_SCALING = 0.5
 18COIN_SCALING = 0.5
 19SPRITE_PIXEL_SIZE = 128
 20GRID_PIXEL_SIZE = SPRITE_PIXEL_SIZE * TILE_SCALING
 21
 22# Movement speed of player, in pixels per frame
 23PLAYER_MOVEMENT_SPEED = 10
 24GRAVITY = 1
 25PLAYER_JUMP_SPEED = 20
 26
 27
 28class MyGame(arcade.Window):
 29    """
 30    Main application class.
 31    """
 32
 33    def __init__(self):
 34
 35        # Call the parent class and set up the window
 36        super().__init__(SCREEN_WIDTH, SCREEN_HEIGHT,
 37                         SCREEN_TITLE, resizable=True)
 38
 39        # Our TileMap Object
 40        self.tile_map = None
 41
 42        # Our Scene Object
 43        self.scene = None
 44
 45        # Separate variable that holds the player sprite
 46        self.player_sprite = None
 47
 48        # Our physics engine
 49        self.physics_engine = None
 50
 51        # A Camera that can be used for scrolling the screen
 52        self.camera_sprites = None
 53
 54        # A non-scrolling camera that can be used to draw GUI elements
 55        self.camera_gui = None
 56
 57        # Keep track of the score
 58        self.score = 0
 59
 60        # What key is pressed down?
 61        self.left_key_down = False
 62        self.right_key_down = False
 63
 64    def setup(self):
 65        """Set up the game here. Call this function to restart the game."""
 66
 67        # Setup the Cameras
 68        self.camera_sprites = arcade.camera.Camera2D()
 69        self.camera_gui = arcade.camera.Camera2D()
 70
 71        # Name of map file to load
 72        map_name = ":resources:tiled_maps/map.json"
 73
 74        # Layer specific options are defined based on Layer names in a dictionary
 75        # Doing this will make the SpriteList for the platforms layer
 76        # use spatial hashing for detection.
 77        layer_options = {
 78            "Platforms": {
 79                "use_spatial_hash": True,
 80            },
 81        }
 82
 83        # Read in the tiled map
 84        self.tile_map = arcade.load_tilemap(map_name, TILE_SCALING, layer_options)
 85
 86        # Initialize Scene with our TileMap, this will automatically add all layers
 87        # from the map as SpriteLists in the scene in the proper order.
 88        self.scene = arcade.Scene.from_tilemap(self.tile_map)
 89
 90        # Set the background color
 91        if self.tile_map.background_color:
 92            self.background_color = self.tile_map.background_color
 93
 94        # Keep track of the score
 95        self.score = 0
 96
 97        # Set up the player, specifically placing it at these coordinates.
 98        src = ":resources:images/animated_characters/female_adventurer/femaleAdventurer_idle.png"
 99        self.player_sprite = arcade.Sprite(src, scale=CHARACTER_SCALING)
100        self.player_sprite.center_x = 128
101        self.player_sprite.center_y = 128
102        self.scene.add_sprite("Player", self.player_sprite)
103
104        # --- Other stuff
105        # Create the 'physics engine'
106        self.physics_engine = arcade.PhysicsEnginePlatformer(
107            self.player_sprite, gravity_constant=GRAVITY, walls=self.scene["Platforms"]
108        )
109
110    def on_draw(self):
111        """Render the screen."""
112
113        # Clear the screen to the background color
114        self.clear()
115
116        # Activate the game camera
117        self.camera_sprites.use()
118
119        # Draw our Scene
120        # Note, if you a want pixelated look, add pixelated=True to the parameters
121        self.scene.draw()
122
123        # Activate the GUI camera before drawing GUI elements
124        self.camera_gui.use()
125
126        # Draw our score on the screen, scrolling it with the viewport
127        score_text = f"Score: {self.score}"
128        arcade.draw_text(score_text,
129                         x=10,
130                         y=10,
131                         color=arcade.csscolor.WHITE,
132                         font_size=18)
133
134    def update_player_speed(self):
135
136        # Calculate speed based on the keys pressed
137        self.player_sprite.change_x = 0
138
139        if self.left_key_down and not self.right_key_down:
140            self.player_sprite.change_x = -PLAYER_MOVEMENT_SPEED
141        elif self.right_key_down and not self.left_key_down:
142            self.player_sprite.change_x = PLAYER_MOVEMENT_SPEED
143
144    def on_key_press(self, key, modifiers):
145        """Called whenever a key is pressed."""
146
147        # Jump
148        if key == arcade.key.UP or key == arcade.key.W:
149            if self.physics_engine.can_jump():
150                self.player_sprite.change_y = PLAYER_JUMP_SPEED
151
152        # Left
153        elif key == arcade.key.LEFT or key == arcade.key.A:
154            self.left_key_down = True
155            self.update_player_speed()
156
157        # Right
158        elif key == arcade.key.RIGHT or key == arcade.key.D:
159            self.right_key_down = True
160            self.update_player_speed()
161
162    def on_key_release(self, key, modifiers):
163        """Called when the user releases a key."""
164        if key == arcade.key.LEFT or key == arcade.key.A:
165            self.left_key_down = False
166            self.update_player_speed()
167        elif key == arcade.key.RIGHT or key == arcade.key.D:
168            self.right_key_down = False
169            self.update_player_speed()
170
171    def center_camera_to_player(self):
172        # Find where player is, then calculate lower left corner from that
173        screen_center_x = self.player_sprite.center_x
174        screen_center_y = self.player_sprite.center_y
175
176        # Set some limits on how far we scroll
177        if screen_center_x - self.width/2 < 0:
178            screen_center_x = self.width/2
179        if screen_center_y - self.height/2 < 0:
180            screen_center_y = self.height/2
181
182        # Here's our center, move to it
183        player_centered = screen_center_x, screen_center_y
184        self.camera_sprites.position = arcade.math.lerp_2d(self.camera_sprites.position, player_centered, 0.1)
185
186    def on_update(self, delta_time):
187        """Movement and game logic"""
188
189        # Move the player with the physics engine
190        self.physics_engine.update()
191
192        # See if we hit any coins
193        coin_hit_list = arcade.check_for_collision_with_list(
194            self.player_sprite, self.scene["Coins"]
195        )
196
197        # Loop through each coin we hit (if any) and remove it
198        for coin in coin_hit_list:
199            # Remove the coin
200            coin.remove_from_sprite_lists()
201            # Add one to the score
202            self.score += 1
203
204        # Position the camera
205        self.center_camera_to_player()
206
207    def on_resize(self, width: int, height: int):
208        """ Resize window """
209        super().on_resize(width, height)
210        self.camera_sprites.match_screen(and_projection=True)
211        self.camera_gui.match_screen(and_projection=True)
212
213
214def main():
215    """Main function"""
216    window = MyGame()
217    window.setup()
218    arcade.run()
219
220
221if __name__ == "__main__":
222    main()