hump.timer.actions

Composable actions, powered by hump.timer. Inspired by LibGDX actions. Represents a monoid. This approach also lends itself to manipulation by higher order functions (similar to parser combinators).

Example

local Actions = require "actions"
local Timer = require "hump.timer"

local objectA = {val = 0}, objectB = {val = 0}
local action = Actions.Sequence(
	Actions.Print("Started action..."),
	Actions.Wait(3),
	Actions.Print("3 seconds passed..."),
	Actions.Parallel(
		Actions.Tween(3.0, objectA, {val=10}, 'linear'),
		Actions.Tween(2.0, objectB, {val=10}, 'linear')
	)
)

--[[ Play the action by calling it as a function.
The first argument is the Hump.Timer object used to run
events, and the second argument is a continuation to
be run on the completion of the action. ]]--
action(Timer, function()
	print("Continuation...")
end)

Documentation

Action Primitives

These functions return actions that, when played, will do something.

Actions.Empty()

An empty 'identity' action which does nothing.

Actions.Wait(duration)

An action which waits for the provided amount of seconds.

Actions.Do(func)

An action which invokes the provided function, then continues.

Actions.Print(func)

An action which prints to the console.

Actions.Tween(duration, subject, target, method, ...)

Tweens an object. See Timer.tween for more details.

Combinators

Combinators take in actions, compose them, and return new actions that can be further composed.

Actions.Sequence(...)

Takes in a variable number of actions, and returns a new action which plays them all in sequence.

Actions.Parallel(...)

Takes in a variable number of actions, and returns a new action which plays them all in parallel. The continuation is invoked when

Creating a Custom Action Primitive

Part of what makes this approach effective is that you can create your own Action primitives. Here are some examples.

function Actions.PlaySource(source)
  return function(timer, cont)
    love.audio.play(source)
    cont()
  end
end

function Actions.DestroyEntity(entity)
  return function(timer, cont)
    entity:destroy()
    cont()
  end
end