CAAnimation-EasingEquations

A category on CAAnimation that provides a number of easing equations to add some zazz to your app (with examples!)

Why?

Because adding easing to animations makes them more realistic. UIKit provides a very limited set of easing functions, so I added a few more.

Easings.net provides some good examples and further explanation.

To use

Add pod 'CAAnimation-EasingEquations' to your podfile

Or

• Link your build target with QuartzCore
  • Select your project in Xcode's project navigator
  • Select your project's target
  • Navigate to "Build Phases"
  • In the "Link Binary with Libraries" section, click the '+' button
  • Select QuartzCore and click "Add"
• Add CAAnimation+EasingEquations.h/m to your project
• Enjoy!

Animating layer properties with key paths

Because this uses CoreAnimation, animations are applied to CALayer objects. For example, if we wanted a UIView to become completely transparent over the course of a second, the code to do that would look like this:

    [CAAnimation addAnimationToLayer:animatedView.layer
                         withKeyPath:@"opacity"
                            duration:1
                                  to:0
                      easingFunction:CAAnimationEasingFuctionEaseInBounce];

In this example, the bounce ease-in function would be used.

Animating layer transforms

Similarly to above, if we wanted to apply a transform to animatedView, we could do it like so:

    CATransform3D tr;
    tr = CATransform3DMakeScale(2.5, 2.5, 1.0);
    tr = CATransform3DTranslate(tr, 95, 0, 0);
    [CAAnimation addAnimationToLayer:animatedView.layer
                            duration:1
                           transform:tr
                      easingFunction:CAAnimationEasingFuctionEaseOutBack];

This would scale animatedView to 2.5x its current size and translate it 95px to the right over the course of 1 second.

Examples

Two sample projets have been included to illustrate the use of this category.

OKEasingFunctions

This illustrates the different easing functions. This was written before the addition of CATransform3D animation functions, so all animations are performed with key paths.

TransformAnimations

This illustrates the CATransform3D additions. There are two tables, each with a swipe gesture recognizer. Swipe, and they animate. It's magic!

License

CAAnimation+EasingEquations is licensed under the MIT License. Please give me some kind of attribution if you use it in your project, such as a "thanks" note somewhere. I'd also love to know if you use my code, please drop me a line if you do! See the LICENSE file for full license text.