A library of easing functions for C, C++, and Objective-C
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warrenm Merge pull request #23 from karlvoskuil/master
Declare AHFloat using type alias rather than macro.
Latest commit bf764c9 Nov 30, 2016



A supplemental library of easing functions for C, C++, and Objective-C

The useful portion of this project consists of two parts:

  1. A stand-alone easing function library, implemented in C (easing.h/easing.c)
  2. CAAnimation category methods to more easily use easing in your Core Animation projects

Supported functions

The following types of easing functions are supported:

  • Linear
  • Quadratic
  • Cubic
  • Quartic
  • Quintic
  • Sine
  • Circular
  • Elastic
  • Bounce
  • Back

Each of these has corresponding ease-in, ease-out, and ease-in-out variants. Here's a handy cheat sheet that includes visualizations and animation demos for these functions.

The core easing functions are implemented as C functions that take a time parameter and return a progress parameter, which can subsequently be used to interpolate any quantity.


The design goals of AHEasing are:

  • To be as fast as conceivably possible while maintaining human readability
  • To be portable to any system with a C runtime
  • To elucidate the mathematical underpinnings of common easing functions


This work is a spiritual descendent (not to say derivative work) of works done by the following individuals: