Events

Events#

Make Your Game Interactive#

In this section, you’ll learn how to make your game interactive by responding to keyboard input, mouse actions, or collisions.

What Are Events?#

Events are the key to interactive games. They allow your game to respond to user actions such as key presses or mouse movements, and dynamically change the behavior of your actors.

  • on_setup(): Called at the beginning to initialize and prepare your world.

  • act(): Called on every frame to update the world and its actors.

  • There are special event methods like on_key_pressed, on_mouse_left, or on_clicked_left to respond to user actions.

Registering Events#

For an actor or the world to respond to an event, the corresponding method must be registered — just like with the act() method.

Example: Simple Keyboard Input#

@player.register  # Registers the method as an event
def on_key_down_w(self):
    self.y -= 1  # Moves the player upward

Explanation:#

This method is executed when the w key is pressed. The player actor moves up by one step.

Example: Multi-Key Movement#

In the next example, an actor is controlled using the W, A, S, and D keys:

import miniworlds

world = miniworlds.TiledWorld()
world.columns = 20
world.rows = 8
world.tile_size = 42
world.add_background("images/soccer_green.jpg")

player = miniworlds.Actor()
player.add_costume("images/player_1.png")

@player.register
def on_key_down_w(self):
    self.y = self.y - 1  # Move actor up

@player.register
def on_key_down_a(self):
    self.x = self.x - 1  # Move actor left

@player.register
def on_key_down_d(self):
    self.x = self.x + 1  # Move actor right

@player.register
def on_key_down_s(self):
    self.y = self.y + 1  # Move actor down

world.run()

Explanation:#

In this example, the actor is controlled as follows:

  • W: Move up

  • A: Move left

  • D: Move right

  • S: Move down

Difference: on_key_down vs. on_key_pressed#

There are two types of keyboard events for handling key input:

  • on_key_down(self, key): Called once when the key is initially pressed.

  • on_key_pressed(self, key): Continuously called while the key is being held down.

Example: Different Keyboard Events#

import miniworlds 

world = miniworlds.World()
world.add_background("images/grass.jpg")

player = miniworlds.Actor((90, 90))
player.add_costume("images/player.png")
player.costume.orientation = -90 

@player.register
def on_key_down_w(self):
    self.y -= 1  # Moves player 1 upward

player2 = miniworlds.Actor((180, 180))
player2.add_costume("images/player.png")
player2.costume.orientation = -90 

@player2.register
def on_key_pressed_s(self):
    self.y -= 1  # Continuously moves player 2 downward while key is held

world.run()

Note

You can either define specific keys like on_key_down_b(self)
or handle all key input using on_key_down(self, key) for general keyboard event handling.

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