Step 7 - Add Coins And Sound#
Next we will add some coins that the player can pickup. We’ll also add a sound to be played when they pick it up, as well as a sound for when they jump.
Adding Coins to the Scene#
First we need to add our coins to the scene. Let’s start by adding a constant at the
top of our application for the coin sprite scaling, similar to our TILE_SCALING one.
CHARACTER_SCALING = 1
Next in our setup function we can create our coins using a for loop like we’ve done for
the ground previously, and then add them to the scene.
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
Loading Sounds#
Now we can load in our sounds for collecting the coin and jumping. Later we will use these
variables to play the sounds when the specific events happen. Add the following to the
__init__ function to load the sounds:
self.camera = None
# Load sounds
Then we can play our jump sound when the player jumps, by adding it to the on_key_press function:
self.scene.draw()
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
Collision Detection#
Lastly, we need to find out if the player hit a coin. We can do this in our on_update
function by using the arcade.check_for_collision_with_list function. We can pass the
player sprite, along with a SpriteList that holds the coins. The function will return
a list of the coins that the player is currently colliding with. If there are no coins in
contact, the list will be empty.
Then we can use the Sprite.remove_from_sprite_lists function which will remove a given
sprite from any SpriteLists it belongs to, effectively deleting it from the game.
Note
Notice that any transparent “white-space” around the image counts as the hitbox. You can trim the space in a graphics editor, or later on, we’ll go over how to customize the hitbox of a Sprite.
Add the following to the on_update function to add collision detection and play a sound
when the player picks up a coin.
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()
Note
Spend time placing the coins where you would like them. If you have extra time, try adding more than just coins. Also add gems or keys from the graphics provided.
You could also subclass the coin sprite and add an attribute for a score value. Then you could have coins worth one point, and gems worth 5, 10, and 15 points.
Source Code#
1"""
2Platformer Game
3
4python -m arcade.examples.platform_tutorial.07_coins_and_sound
5"""
6import arcade
7
8# Constants
9SCREEN_WIDTH = 1000
10SCREEN_HEIGHT = 650
11SCREEN_TITLE = "Platformer"
12
13# Constants used to scale our sprites from their original size
14CHARACTER_SCALING = 1
15TILE_SCALING = 0.5
16COIN_SCALING = 0.5
17
18# Movement speed of player, in pixels per frame
19PLAYER_MOVEMENT_SPEED = 5
20GRAVITY = 1
21PLAYER_JUMP_SPEED = 20
22
23
24class MyGame(arcade.Window):
25 """
26 Main application class.
27 """
28
29 def __init__(self):
30
31 # Call the parent class and set up the window
32 super().__init__(SCREEN_WIDTH, SCREEN_HEIGHT, SCREEN_TITLE)
33
34 # Our Scene Object
35 self.scene = None
36
37 # Separate variable that holds the player sprite
38 self.player_sprite = None
39
40 # Our physics engine
41 self.physics_engine = None
42
43 # A Camera that can be used for scrolling the screen
44 self.camera = None
45
46 # Load sounds
47 self.collect_coin_sound = arcade.load_sound(":resources:sounds/coin1.wav")
48 self.jump_sound = arcade.load_sound(":resources:sounds/jump1.wav")
49
50 self.background_color = arcade.csscolor.CORNFLOWER_BLUE
51
52 def setup(self):
53 """Set up the game here. Call this function to restart the game."""
54
55 # Set up the Camera
56 self.camera = arcade.SimpleCamera(viewport=(0, 0, self.width, self.height))
57
58 # Initialize Scene
59 self.scene = arcade.Scene()
60
61 # Set up the player, specifically placing it at these coordinates.
62 image_source = ":resources:images/animated_characters/female_adventurer/femaleAdventurer_idle.png"
63 self.player_sprite = arcade.Sprite(image_source, CHARACTER_SCALING)
64 self.player_sprite.center_x = 64
65 self.player_sprite.center_y = 128
66 self.scene.add_sprite("Player", self.player_sprite)
67
68 # Create the ground
69 # This shows using a loop to place multiple sprites horizontally
70 for x in range(0, 1250, 64):
71 wall = arcade.Sprite(":resources:images/tiles/grassMid.png", TILE_SCALING)
72 wall.center_x = x
73 wall.center_y = 32
74 self.scene.add_sprite("Walls", wall)
75
76 # Put some crates on the ground
77 # This shows using a coordinate list to place sprites
78 coordinate_list = [[512, 96], [256, 96], [768, 96]]
79
80 for coordinate in coordinate_list:
81 # Add a crate on the ground
82 wall = arcade.Sprite(
83 ":resources:images/tiles/boxCrate_double.png", TILE_SCALING
84 )
85 wall.position = coordinate
86 self.scene.add_sprite("Walls", wall)
87
88 # Use a loop to place some coins for our character to pick up
89 for x in range(128, 1250, 256):
90 coin = arcade.Sprite(":resources:images/items/coinGold.png", COIN_SCALING)
91 coin.center_x = x
92 coin.center_y = 96
93 self.scene.add_sprite("Coins", coin)
94
95 # Create the 'physics engine'
96 self.physics_engine = arcade.PhysicsEnginePlatformer(
97 self.player_sprite, gravity_constant=GRAVITY, walls=self.scene["Walls"]
98 )
99
100 def on_draw(self):
101 """Render the screen."""
102
103 # Clear the screen to the background color
104 self.clear()
105
106 # Activate our Camera
107 self.camera.use()
108
109 # Draw our Scene
110 self.scene.draw()
111
112 def on_key_press(self, key, modifiers):
113 """Called whenever a key is pressed."""
114
115 if key == arcade.key.UP or key == arcade.key.W:
116 if self.physics_engine.can_jump():
117 self.player_sprite.change_y = PLAYER_JUMP_SPEED
118 arcade.play_sound(self.jump_sound)
119 elif key == arcade.key.LEFT or key == arcade.key.A:
120 self.player_sprite.change_x = -PLAYER_MOVEMENT_SPEED
121 elif key == arcade.key.RIGHT or key == arcade.key.D:
122 self.player_sprite.change_x = PLAYER_MOVEMENT_SPEED
123
124 def on_key_release(self, key, modifiers):
125 """Called when the user releases a key."""
126
127 if key == arcade.key.LEFT or key == arcade.key.A:
128 self.player_sprite.change_x = 0
129 elif key == arcade.key.RIGHT or key == arcade.key.D:
130 self.player_sprite.change_x = 0
131
132 def center_camera_to_player(self):
133 screen_center_x = self.player_sprite.center_x - (self.camera.viewport_width / 2)
134 screen_center_y = self.player_sprite.center_y - (
135 self.camera.viewport_height / 2
136 )
137 if screen_center_x < 0:
138 screen_center_x = 0
139 if screen_center_y < 0:
140 screen_center_y = 0
141 player_centered = screen_center_x, screen_center_y
142
143 self.camera.move_to(player_centered)
144
145 def on_update(self, delta_time):
146 """Movement and game logic"""
147
148 # Move the player with the physics engine
149 self.physics_engine.update()
150
151 # See if we hit any coins
152 coin_hit_list = arcade.check_for_collision_with_list(
153 self.player_sprite, self.scene["Coins"]
154 )
155
156 # Loop through each coin we hit (if any) and remove it
157 for coin in coin_hit_list:
158 # Remove the coin
159 coin.remove_from_sprite_lists()
160 # Play a sound
161 arcade.play_sound(self.collect_coin_sound)
162
163 # Position the camera
164 self.center_camera_to_player()
165
166
167def main():
168 """Main function"""
169 window = MyGame()
170 window.setup()
171 arcade.run()
172
173
174if __name__ == "__main__":
175 main()