Baton

Baton is an input library for LÖVE that bridges the gap between keyboard and gamepad controls and allows you to easily define and change controls on the fly.

local baton = require 'baton'

local input = baton.new {
  controls = {
    left = {'key:left', 'axis:leftx-', 'button:dpleft'},
    right = {'key:right', 'axis:leftx+', 'button:dpright'},
    up = {'key:up', 'axis:lefty-', 'button:dpup'},
    down = {'key:down', 'axis:lefty+', 'button:dpdown'},
    action = {'key:x', 'button:a'},
  },
  pairs = {
    move = {'left', 'right', 'up', 'down'}
  },
  joystick = love.joystick.getJoysticks()[1],
}

function love.update(dt)
  input:update()

  local x, y = input:get 'move'
  playerShip:move(x*100, y*100)
  if input:pressed 'action' then
    playerShip:shoot()
  end
end

Installation

To use Baton, place baton.lua in your project, and then add this code to your main.lua:

baton = require 'baton' -- if your baton.lua is in the root directory
baton = require 'path.to.baton' -- if it's in subfolders

Usage

Defining controls

Controls are defined using a table. Each key should be the name of a control, and each value should be another table. This table contains strings defining what sources should be mapped to the control. For example, this table

controls = {
  left = {'key:left', 'axis:leftx-'}
  shoot = {'key:x', 'button:a'}
}

will create a control called "left" that responds to the left arrow key and pushing the left analog stick on the controller to the left, and a control called "shoot" that responds to the X key on the keyboard and the A button on the gamepad.

Sources are strings with the following format:

'[input type]:[input source]'

Here are the different input types and the sources that can be associated with them:

Type	Description	Source
`key`	A keyboard key.	Any LÖVE KeyConstant
`sc`	A scancode.	Any LÖVE KeyConstant
`mouse`	A mouse button.	A number representing a mouse button (see love.mouse.isDown)
`axis`	A joystick or gamepad axis.	Either a number representing a joystick axis or a LÖVE GamepadAxis. Add a '+' or '-' on the end to denote the direction to detect.
`button`	A joystick or gamepad button.	Either a number repesenting a joystick button or a LÖVE GamepadButton
`hat`	A joystick hat.	A number representing a joystick hat and a JoystickHat. For example '1r' corresponds to the 1st hat pushed right.

Defining axis pairs

Baton allows you to define axis pairs, which group four controls under a single name. This is perfect for analog sticks, arrow keys, etc., as it allows you to get x and y components quickly. Each pair is defined by a table with the names of the four controls (in the order left, right, up, down).

pairs = {
  move = {'moveLeft', 'moveRight', 'moveUp', 'moveDown'},
  aim = {'aimLeft', 'aimRight', 'aimUp', 'aimDown'},
}

Players

Players are the objects that monitor and manage inputs.

Creating players

To create a player, use baton.new:

player = baton.new(options)

options is a table containing the following values:

controls - a table of controls
pairs - a table of axis pairs (optional)
joystick - a LÖVE joystick (returned from love.joystick.getJoysticks). The joystick argument is optional; if it's not specified, or if the joystick becomes unavailable later, the player object will just ignore controller inputs.

Updating players

You should update each player each frame by calling this function:

player:update()

Getting the value of controls

To get the value of a control, use:

value = player:get(control)

For example, for the controls defined above, we could get the value of the "left" control by doing

left = player:get 'left'

player:get always returns a number between 0 and 1, and as such, it is most applicable to controls that act as axes, such as movement controls. To get the value of a control without applying the deadzone, use player:getRaw.

Getting the value of axis pairs

player.get can also get the x and y components of an axis pair.

x, y = player:get(pair)

In this case, x and y are numbers between -1 and 1. The length of the vector x, y is capped to 1. player.getRaw will return the value of axis pairs without deadzone applied.

Getting down, pressed, and released states

To see whether a control is currently "held down", use:

down = player:down(control)

player:down returns true if the value of the control is greater than the deadzone, and false if not.

pressed = player:pressed(control)

player:pressed return true if the control was pressed this frame, and false if not.

released = player:released(control)

player:released return true if the control was released this frame, and false if not.

These functions are most applicable for controls that act as buttons, such as a shoot button. That being said, they can be used for any control, which is useful if you want to, for example, use a movement control as a discrete button press to operate a menu.

Changing controls

At any time, you can change the sources for a player's controls by modifying the controls table, which can be accessed via player.config.controls.

Note: removing a control entirely (by running player.config.controls.left = nil, for example) will cause errors. If you want to disable a control, you can set it to an empty table, thus removing all of the sources. Also note that the player object cannot detect if new controls are added.

Changing the deadzone

You can change the deadzone of a player by setting player.config.deadzone to a number between 0 and 1. The deadzone is set to 0.5 by default. If you set player.config.squareDeadzone to true, axis pairs will apply deadzone individually to each axis.

Reassigning joysticks

If you need to change the joystick associated with a player, just set player.config.joystick (which is just a standard LÖVE Joystick object).

Getting the active input device

At any time, only the keyboard/mouse sources or the gamepad sources for a player will be active. A device will be considered active if any of the sources for that device exceed the deadzone. The keyboard and mouse will always take precedence over the gamepad.

You can call player:getActiveDevice() to see which input device is currently active. It will return either 'keyboard' or 'joystick' (or nil if no sources have been used yet). This is useful if you need to change what you display on screen based on the controls the player is using (such as instructions).

Note: mouse sources are counted under keyboard.

Contributing

This library is still fairly young, so feel free to take it for a spin and suggest additions and changes (especially if you try making a multiplayer game with it!). Issues and pull requests are always welcome. To run the test, run love . in the baton folder.

License

MIT License

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

pablomayobre/baton