In this article, we will learn How we can add collisions in arcade games in Python.
Installation
You can install the Arcade module using the below command:
pip install arcade
Example 1:
In this example, we are going to use the check_for_collision() function to add collision between 2 sprites.
Syntax: arcade.check_for_collision( sprite1, sprite2)
Parameters:
- sprite1:- First sprite
- sprite2:- Second sprite
Returns: Boolean value
Sprites Used:
Below is the implementation:
# Importing arcade module
import arcade
# Creating MainGame class
class MainGame(arcade.Window):
def __init__(self):
super().__init__(600, 600, title="Player Movement")
# Initializing a variable to store
# the velocity of Player1 and Player2
self.vel_x1 = 380
self.vel_x2 = 380
self.scene = None
# Creating variable to store player sprite
self.player1 = None
# Creating variable to store player sprite
self.player2 = None
# Creating on_draw() function to draw on the screen
def on_draw(self):
arcade.start_render()
# Drawing the scene
self.scene.draw()
def setup(self):
# Creating scene
self.scene = arcade.Scene()
# Adding player sprite
self.player_sprite1 = arcade.Sprite("Player.png", 1)
self.player_sprite2 = arcade.Sprite("Player2.png", 1)
# Adding coordinates for the center of the sprite
self.player_sprite1.center_x = 20
self.player_sprite1.center_y = 300
# Adding coordinates for the center of the sprite
self.player_sprite2.center_x = 580
self.player_sprite2.center_y = 300
# Adding sprites in scene
self.scene.add_sprite('Player', self.player_sprite1)
self.scene.add_sprite('Player', self.player_sprite2)
# Creating on_update function to
# update the x coordinate
def on_update(self, delta_time):
# Changing x coordinate of players
self.player_sprite1.center_x += self.vel_x1 * delta_time
self.player_sprite2.center_x -= self.vel_x2 * delta_time
# Checking if sprites are colliding or not
colliding = arcade.check_for_collision(
self.player_sprite1, self.player_sprite2)
# If sprites are colliding then changing direction
if colliding:
self.vel_x1 *= -1
self.vel_x2 *= -1
# Changing the direction if sprites crosses the screen boundary
if self.player_sprite1.center_x > 600 or self.player_sprite1.center_x < 0:
self.vel_x1 *= -1
if self.player_sprite2.center_x > 600 or self.player_sprite2.center_x < 0:
self.vel_x2 *= -1
# Calling MainGame class
game = MainGame()
game.setup()
arcade.run()
Output:
Example 2:
In this example, we are going to use PhysicsEnginePlatformer() function to add collision between our player and platform.
Syntax: arcade.PhysicsEnginePlatformer(player_sprite, platforms,, gravity, ladders)
Parameters:
- player_sprite:- The player sprite
- platforms:- The platform sprite list
- gravity:- Amount of gravity
- ladders:- Ladders the user can climb on
Sprites Used:
Below is the implementation:
# Importing arcade module
import arcade
# Creating MainGame class
class MainGame(arcade.Window):
def __init__(self):
super().__init__(600, 600, title="Player Movement")
# Initializing a variable to store
# the velocity of the player
self.vel_x = 0
# Creating scene object
self.scene = None
# Creating variable to store player sprite
self.player = None
# Creating variable for our game engine
self.physics_engine = None
# Creating on_draw() function to draw on the screen
def on_draw(self):
arcade.start_render()
# Drawing our scene
self.scene.draw()
def setup(self):
# Initialize Scene object
self.scene = arcade.Scene()
# Creating different sprite lists
self.scene.add_sprite_list("Player")
self.scene.add_sprite_list("Platforms", use_spatial_hash=True)
# Adding player sprite
self.player_sprite = arcade.Sprite("Player.png", 1)
# Adding coordinates for the center of the sprite
self.player_sprite.center_x = 64
self.player_sprite.center_y = 600
# Adding Sprite in our scene
self.scene.add_sprite("Player", self.player_sprite)
# Adding platform sprite
platform = arcade.Sprite("Platform.png", 1)
# Adding coordinates for the center of the platform
platform.center_x = 300
platform.center_y = 32
self.scene.add_sprite("Platforms", platform)
# Creating Physics engine
self.physics_engine = arcade.PhysicsEnginePlatformer(
self.player_sprite, self.scene.get_sprite_list("Platforms"), 0.5
)
# Creating on_update function to
# update the x coordinate
def on_update(self, delta_time):
# Changing x coordinate of player
self.player_sprite.center_x += self.vel_x * delta_time
# Updating the physics engine to move the player
self.physics_engine.update()
# Creating function to change the velocity
# when button is pressed
def on_key_press(self, symbol, modifier):
# Checking the button pressed
# and changing the value of velocity
if symbol == arcade.key.LEFT:
self.vel_x = -300
elif symbol == arcade.key.RIGHT:
self.vel_x = 300
# Creating function to change the velocity
# when button is released
def on_key_release(self, symbol, modifier):
# Checking the button released
# and changing the value of velocity
if symbol == arcade.key.LEFT:
self.vel_x = 0
elif symbol == arcade.key.RIGHT:
self.vel_x = 0
# Calling MainGame class
game = MainGame()
game.setup()
arcade.run()
Output:
