@enact/ui/useScroll/utilAnimation.js

A collection of simplified unstyled cross-platform UI components for Enact

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.utilAnimation = exports["default"] = void 0;
/*
 * Create a cubic-bezier easing function evaluator.
 */
var utilAnimation = exports.utilAnimation = function utilAnimation(x1, y1, x2, y2) {
  var AX = 1 + 3 * x1 - 3 * x2;
  var BX = 3 * x2 - 6 * x1;
  var CX = 3 * x1;
  var AY = 1 + 3 * y1 - 3 * y2;
  var BY = 3 * y2 - 6 * y1;
  var CY = 3 * y1;
  function sampleCurveX(t) {
    return ((AX * t + BX) * t + CX) * t;
  }
  function sampleCurveY(t) {
    return ((AY * t + BY) * t + CY) * t;
  }
  function sampleCurveDerivativeX(t) {
    return (3 * AX * t + 2 * BX) * t + CX;
  }
  function solveCurveX(x) {
    var t0 = x;
    var t1, t2;
    for (var i = 0; i < 4; ++i) {
      t2 = sampleCurveX(t0) - x;
      if (Math.abs(t2) < 0.001) return t0;
      t1 = sampleCurveDerivativeX(t0);
      if (Math.abs(t1) < 1e-6) break;
      t0 = t0 - t2 / t1;
    }
    return t0;
  }
  return {
    cubicBezier: function cubicBezier(x) {
      if (x === 0) return 0;
      if (x === 1) return 1;
      var t = solveCurveX(x);
      return sampleCurveY(t);
    }
  };
};
var _default = exports["default"] = utilAnimation;