MEEaseFunctions is an Objective-C class that gives interpreted CATimingFunctions based on Robert Penners. You can use these as you would any other CATimingFunctions within CoreAnimation.
These easing functions are interpreted from Robert Penners easing functions that are commonly used in Flash animation and interfaces
Robert Penners easing functions use math algorithms to calculate easing values. Core Animations CATimingFunctions are based on Bezier curves, and are constructed from two end points and two control points. Because of this the MEEaseFunctions are literally traced from visual representations of Robert Penners equations.
Because Core Animation uses simple Bezier curves it is impossible to replicate the bounce and elastic easing functions.
MEEaseFunctions are very simple to use. Just import the MEEaseFunctions.h header into your class then use the following line of code to retrieve the TimingFunction that you want.
[MEEaseFunctionBuilder functionWithType:xxx] where
xxx is the easing function e.g. EaseTypeExpoOut
This can obviously used inline as so
[CATransaction setAnimationTimingFunction:[MEEaseFunctionBuilder functionWithType: EaseTypeExpoOut]];
This code is distributed under the terms and conditions of the MIT license.
Copyright (c) 2011 Niall McCormack
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Version 0.1 @ 13 July 2011
- Initial release