state.md

Input state

Use the State module to keep track of the current state of actions such as if a key or game pad button is pressed or not.

Usage

You can use the State module in two ways. One is to use the global State module:

local state = require "in.state"

function init(self)
	msg.post(".", "acquire_input_focus")
end

function update(self, dt)
	if state.is_pressed(hash("move_left")) then
		go.set_position(go.get_position() - vmath.vector3(50, 0, 0) * dt)
	elseif state.is_pressed(hash("move_right")) then
		go.set_position(go.get_position() + vmath.vector3(50, 0, 0) * dt)
	end
end

function on_input(self, action_id, action)
	state.on_input(action_id, action)
end

The other way to use the State module is to create a unique instance. This is useful in multi-player games and when combining the State module with the Mapper module:

local state = require "in.state"
local mapper = require "in.mapper"

function init(self)
	msg.post(".", "acquire_input_focus")
	self.state = state.create()
end

function update(self, dt)
	if self.state.is_pressed(hash("move_left")) then
		go.set_position(go.get_position() - vmath.vector3(50, 0, 0) * dt)
	elseif self.state.is_pressed(hash("move_right")) then
		go.set_position(go.get_position() + vmath.vector3(50, 0, 0) * dt)
	end
	-- alternative use
	if state.is_pressed(hash("fire"), self.state) then
		print("Pew pew!")
	end
end

function on_input(self, action_id, action)
	self.state.on_input(mapper.on_input(action_id, 1), action)
	-- alternative use
	state.on_input(mapper.on_input(action_id, 1), action, self.state)
end

API

state.acquire([instance])

Acquire input focus

state.release([instance])

Release input focus

state.on_input(action_id, action, [instance])

Register the state of an action_id

state.is_pressed(action_id, [instance])

Check if an action_id is currently registered as pressed

state.clear([instance])

Clear the state of any registered actions

state.create()

Create a unique instance of the state tracker