wilderness-core/modules/easing-function.js

The SVG animation engine behind Wilderness

var _typeof = typeof Symbol === "function" && typeof Symbol.iterator === "symbol" ? function (obj) { return typeof obj; } : function (obj) { return obj && typeof Symbol === "function" && obj.constructor === Symbol && obj !== Symbol.prototype ? "symbol" : typeof obj; };

/* globals __DEV__ */

import tweenFunctions from 'tween-functions';

/**
 * An easing function.
 *
 * @param {(function|string)} easing - An easing function or the name of an easing function from https://github.com/chenglou/tween-functions.
 *
 * @returns {function}
 *
 * @example
 * easingFunc('easeInOutQuad')
 */
var easingFunction = function easingFunction(easing) {
  switch (typeof easing === 'undefined' ? 'undefined' : _typeof(easing)) {
    case 'string':
      if (tweenFunctions[easing]) {
        return tweenFunctions[easing];
      }

      if (process.env.NODE_ENV !== 'production') {
        throw new TypeError('Easing must match one of the options defined by https://github.com/chenglou/tween-functions');
      }

      /* istanbul ignore next */
      break;

    case 'function':
      return easing;

    default:
      if (process.env.NODE_ENV !== 'production') {
        throw new TypeError('Easing must be of type function or string');
      }

      /* istanbul ignore next */
      break;
  }
};

export default easingFunction;