@dimensionalpocket/game-input

Input handler and normalizer for Javascript games.

Usage

var input = new KeyboardInput(window)

input.on('input', (value) => {
  // By default, pressing 'W' on the keyboard will emit '8' (directional up)
  console.log('Pressed', value)
})

Controller Layout

Input from different controllers is mapped into the following normalized format:

• 1 to 9 - directional state following Numpad convention, where 5 is neutral.
• A, B, C, X, Y, Z, L, R - action buttons.
• S - Start.
• T - Select/Option/Back.

Subclasses are responsible for mapping keys or gamepad buttons to the actions above.

Class: BaseInput

This is the class inherited by all input handlers.

Properties:

• id - ID of the handler. Should be the shortest string possible, as this value is sent over messaging to workers and remote connections.
• enabled - when true, will emit events. Set to false to temporarily halt input handling.

Methods:

• process(event, state) - parses input events.

Events:

• input (value, handler) - emitted when an input event occurs. The listener receives the following arguments:
  • value - a one-character string that represents the input event. See Inputs section below.
  • handler - the handler instance.

Inputs

Input values are case-sensitive.

Input Value	Description
"A"	A pressed
"B"	B pressed
"C"	C pressed
"X"	X pressed
"Y"	Y pressed
"Z"	Z pressed
"L"	L pressed
"R"	R pressed
"S"	S (Start) pressed
"T"	T (Select/Option/Back) pressed
"a"	A released
"b"	B released
"c"	C released
"x"	X released
"y"	Y released
"z"	Z released
"l"	L released
"r"	R released
"s"	S (Start) released
"t"	T (Select/Option/Back) released
"5"	Neutral directional position
"4"	Left directional position
"6"	Right directional position
"2"	Down directional position
"8"	Up directional position
"1"	Down-Left directional position
"3"	Down-Right directional position
"7"	Up-Left directional position
"9"	Up-Right directional position

Class: KeyboardInput

This handler maps keyboard keys to the proper actions.

It relies on the event.code property, falling back to event.which and event.keyCode otherwise.

It also handles keydown events internally to avoid "input spamming" when the key is held down.

It has a default ID of "Kb".

It requires a window object in its constructor:

var keyboard = new KeyboardInput(window)

Default mappings:

• W - Up
• S - Down
• A - Left
• D - Right
• Y - X
• U - Y
• I - Z
• H - A
• J - B
• K - C
• O - L
• L - R
• Enter - Start
• Backspace - Select/Option

Class: NumpadInput

This handler is a subclass of KeyboardInput that maps its default keys to the right side of the keyboard, allowing two players to use the same keyboard locally.

It has a default ID of "Np".

Note: this handler is not supported by browsers that cannot read event.code events (such as Internet Explorer). That event is the only way to detect "NumpadEnter", otherwise it conflicts with the normal "Enter" key.

Default mappings:

• ArrowUp - Up
• ArrowDown - Down
• ArrowLeft - Left
• ArrowRight - Right
• Numpad7 - X
• Numpad8 - Y
• Numpad9 - Z
• Numpad4 - A
• Numpad5 - B
• Numpad6 - C
• NumpadEnter - Start
• NumpadSubtract - Select/Option

Class: InputSequence

InputSequence instances watch input events and fire callbacks when all events from the sequence are executed in order.

var sequence = new InputSequence('236A')
sequence.register('2')
sequence.register('3')
sequence.register('6')
sequence.register('A')

// Feed events into the instance.
// It will return true once the sequence completes.
sequence.feed('2') // false
sequence.feed('3') // false
sequence.feed('6') // false
sequence.feed('A') // true

Class: InputRouter

An InputRouter instance assembles many InputSequence instances together and sorts them by priority.

var sequence1 = new InputSequence('236A')
var sequence2 = new InputSequence('214A')
var sequence3 = new InputSequence('236236A')
var sequence4 = new InputSequence('B')

// Assign each sequence a priority.
// Higher priority sequences get executed first.
sequence1.priority = 5
sequence2.priority = 5
sequence3.priority = 10
sequence4.priority = 0

var router = new InputRouter()
router.register(sequence1, sequence2, sequence3, sequence4)

// Feed events to all sequences until complete sequences are captured.
// The sequence instance will be returned on capture, false otherwise.
router.feed('2') // false
router.feed('1') // false
router.feed('4') // false
router.feed('A') // sequence instance of '236A'
router.feed('B') // sequence instance of 'B'

Gamepad Support and Contributions

This repository stores the default definitions of known gamepads. As an open-source repository, it allows contributions from other developers and players that would like to add support to different gaming controllers.

As of now, gamepad support is not yet available.

License

MIT