Easing Animation Frames

npm i easing-animation-frames

This is a tiny library for creating CPU-friendly easing animations with requestAnimationFrame API and Robert Penner's easing equations. Suggestions and pull requests for optimization are welcome.

How to use

Select an easing type (cubicInOut by default) and pass a callback function to run for every animation frame which manipulates target DOM elements.

Minimum settings

// Template function
const updateBarWidth = ({ progress }) => {
  // Update the DOM with the progress value
}

easingAnimationFrames({
  template: updateBarWidth // Callback function to run for every frame, which receives progress from 0 to 1
});

With optional settings

// Template function
const updateBarWidth = ({
  progress,
  stopFrames, // Stops the animation
  resumeFrames, // Resumes the animation
  restartFrames, // Restarts the animation
}) => {
  // Update the DOM with the progress value
}

easingAnimationFrames({
  easingType: "quadInOut", // Easing function name
  duration: 3000, // Animation duration in milliseconds
  template: updateBarWidth, // Callback function to run for every frame, which receives progress from 0 to 1
  complete: animationComplete, // Callback funciton to run on completion
});

Duration is set to be 4,000 milliseconds by default, which you can change. Once the animation starts, the callback function (template) receives the progress value (from 0 to 1) that you can use to render the animation. The example above uses (progress * 75)% for the width of the bar, based on the time passed.

npm start to see the example (Node v10.15.1+).

The template function also provides stop and resume functions, if you want to stop the animation before it completes and resume it.

React Easing Animation is a React HOC implementation of this library.

Browser Support

It uses requestAnimationFrame, which should be supported for most of the modern browsers.