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Input

We will now explain how to to access user input (mouse or keyboard), and how to use it in your project easily.

Gamepad

Gamepad support is scheduled for a future release, and is not made available by batFramework. However it is possible to use the pygame events for gamepad (as any other pygame event) in

What is an action​

Actions are a structure used to represent an 'action' that can be triggered by any user input. It is then possible to assign one or more mouse and/or keyboard events as triggers for any specific action.

Each action holds a value (in a majority of cases a boolean) that represents if the action is active.

Example

We might want the player to jump by pressing the <UP> directional key, but also the <W> key on the keyboard.

bf.Action("jump").add_key_control(pygame.K_UP,pygame.K_w)

Why not use events​

It is indeed possible to manage input directly, with if statements, however this can cause issues in projects with larger scale, as well as hinder code readability.

keys = pygame.key.get_pressed()
if keys[pygame.K_w] or keys[pygame.K_UP]:
    jump()

By referring to what you want the player to do with an action like 'jump', it is far more legible and easier to manage than pygame.K_SPACE or pygame.K_w. It also makes it modular and allows for easy remapping for actions.

jump_action = bf.Action("jump").add_key_control(pygame.K_UP,pygame.K_w)
if jump_action.is_active():
    jump()

How to use Actions​

Create an action with :

bf.Action("name")

Assigning​

You can assign any input methods using add_<type>_control() where <type> can be either keyboard, mouse or event. You can combine different input methods in a single action

Keyboard​

bf.Action("test").add_key_control(pygame.K_UP,pygame.K_w)

Mouse​

bf.Action("test").add_mouse_control(1)
Mouse controls

When the argument for add_mouse_control is an integer, it refers to the mouse button mappings from pygame-ce.

Events​

Although not recommended for long term, it is possible to use events directly as triggers for an action. In pygame-ce all event types are integers.

Trigger type​

Insantaneous​

Holding​

Continuous​

Lifecycle​

When an action is created it has to be managed, either manually or automatically. Here's a rundown of what the action needs each frame to work correctly:

  • Call process_event(event:pygame.Event)
  • Call reset() to clear the action

By doing so, it is possible to get the value of the action y--between the process and reset calls

Example​

Here's an example code for a Scene using actions to change the background color.

import batFramework as bf
import pygame
class MyScene(bf.Scene):
    def do_when_added(self):
        self.actions.add(bf.Action("change_color").add_key_control(pygame.K_w,pygame.K_SPACE))