https://github.com/rameshvarun/hump.timer.actions

Composable actions, powered by Hump.Timer.
https://github.com/rameshvarun/hump.timer.actions

love2d lua

Last synced: about 2 months ago
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Composable actions, powered by Hump.Timer.

• Host: GitHub
• URL: https://github.com/rameshvarun/hump.timer.actions
• Owner: rameshvarun
• License: mit
• Created: 2016-01-16T01:19:22.000Z (about 9 years ago)
• Default Branch: master
• Last Pushed: 2023-04-21T17:42:41.000Z (almost 2 years ago)
• Last Synced: 2024-12-21T19:05:24.513Z (about 2 months ago)
• Topics: love2d, lua
• Language: Lua
• Homepage: https://blog.varunramesh.net/posts/composable-animations/
• Size: 13.7 KB
• Stars: 1
• Watchers: 2
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# hump.timer.actions

[![Lua](https://github.com/rameshvarun/hump.timer.actions/actions/workflows/lua.yml/badge.svg)](https://github.com/rameshvarun/hump.timer.actions/actions/workflows/lua.yml)

Composable actions, powered by [hump.timer](https://hump.readthedocs.org/en/latest/timer.html). Inspired by [LibGDX actions](https://github.com/libgdx/libgdx/wiki/Scene2d#actions). Represents a `monoid`. This approach also lends itself to manipulation by higher order functions (similar to parser combinators).

## Example

```lua

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](https://hump.readthedocs.org/en/latest/timer.html#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.

```lua

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

```