This is a lua port of the Robert Penner's equations for easing. You can find much more information about it on [http://www.robertpenner.com/easing/](his web site).
This library was based off:
- [http://code.google.com/p/tweener/](Tweener, ActionScript tweening library)
However, only the easing functions are included, and not any kind of tweening helpers.
Requiring the easing library returns a table which contains all the different functions.
local easingFunctions = require("easing") outInBounce = easingFunctions.outInBounce -- All easing functions take these parameters: -- -- t = time should go from 0 to duration -- b = begin value of the property being ease. -- c = change ending value of the property - beginning value of the property -- d = duration -- Some functions allow additional modifiers, like the elastic functions -- which also can receive an amplitud and a period parameters (defaults -- are included) beginVal = 0 endVal = 1 change = endVal - beginVal duration = 1 print(outInBounce(0 , beginVal, change, duration)) --> 0 print(outInBounce(duration / 4 , beginVal, change, duration)) --> 0.3828125 print(outInBounce(duration / 2 , beginVal, change, duration)) --> 0.5 print(outInBounce(duration / 3/4, beginVal, change, duration)) --> 0.10503472222222 print(outInBounce(duration , beginVal, change, duration)) --> 1
There is a plain lua example and an interactive one based on the LÖVE game library. To run the examples you'll need to get the engine from http://love2d.org. Once you have the love executable, move into the examples/love directory and run "love ."
To run the tests you'll need telescope. From the library's root directory, run:
▸ tsc tests/easing_tests.lua 80 tests 80 passed 80 assertions 0 failed 0 errors 0 unassertive 0 pending
Copy the documentation from the tweener source and convert it to luadoc.
Like the tweener library, easing is licensed under the MIT license.
- Tweener authors
- Yuichi Tateno
- Emmanuel Oga
- kikito (Enrique García) (https://github.com/EmmanuelOga/easing/pull/2)