devextreme/dist/transpiled/animation/easing.js

HTML5 JavaScript Component Suite for Responsive Web Development

"use strict";

var isFunction = require("../core/utils/type").isFunction,
    CSS_TRANSITION_EASING_REGEX = /cubic-bezier\((\d+(?:\.\d+)?)\s*,\s*(\d+(?:\.\d+)?)\s*,\s*(\d+(?:\.\d+)?)\s*,\s*(\d+(?:\.\d+)?)\)/;

var TransitionTimingFuncMap = {
    "linear": "cubic-bezier(0, 0, 1, 1)",
    "swing": "cubic-bezier(0.445, 0.05, 0.55, 0.95)",
    "ease": "cubic-bezier(0.25, 0.1, 0.25, 1)",
    "ease-in": "cubic-bezier(0.42, 0, 1, 1)",
    "ease-out": "cubic-bezier(0, 0, 0.58, 1)",
    "ease-in-out": "cubic-bezier(0.42, 0, 0.58, 1)"
};

var polynomBezier = function polynomBezier(x1, y1, x2, y2) {
    var Cx = 3 * x1,
        Bx = 3 * (x2 - x1) - Cx,
        Ax = 1 - Cx - Bx,
        Cy = 3 * y1,
        By = 3 * (y2 - y1) - Cy,
        Ay = 1 - Cy - By;

    var bezierX = function bezierX(t) {
        return t * (Cx + t * (Bx + t * Ax));
    };

    var bezierY = function bezierY(t) {
        return t * (Cy + t * (By + t * Ay));
    };

    var findXFor = function findXFor(t) {
        var x = t,
            i = 0,
            z;

        while (i < 14) {
            z = bezierX(x) - t;
            if (Math.abs(z) < 1e-3) {
                break;
            }

            x = x - z / derivativeX(x);
            i++;
        }

        return x;
    };

    var derivativeX = function derivativeX(t) {
        return Cx + t * (2 * Bx + t * 3 * Ax);
    };

    return function (t) {
        return bezierY(findXFor(t));
    };
};

var easing = {};
var convertTransitionTimingFuncToEasing = function convertTransitionTimingFuncToEasing(cssTransitionEasing) {
    cssTransitionEasing = TransitionTimingFuncMap[cssTransitionEasing] || cssTransitionEasing;

    var coeffs = cssTransitionEasing.match(CSS_TRANSITION_EASING_REGEX);
    var forceName;

    if (!coeffs) {
        forceName = "linear";
        coeffs = TransitionTimingFuncMap[forceName].match(CSS_TRANSITION_EASING_REGEX);
    }

    coeffs = coeffs.slice(1, 5);
    for (var i = 0; i < coeffs.length; i++) {
        coeffs[i] = parseFloat(coeffs[i]);
    }

    var easingName = forceName || "cubicbezier_" + coeffs.join("_").replace(/\./g, "p");

    if (!isFunction(easing[easingName])) {
        easing[easingName] = function (x, t, b, c, d) {
            return c * polynomBezier(coeffs[0], coeffs[1], coeffs[2], coeffs[3])(t / d) + b;
        };
    }

    return easingName;
};

exports.setEasing = function (value) {
    easing = value;
};

exports.getEasing = function (name) {
    return easing[name];
};

exports.convertTransitionTimingFuncToEasing = convertTransitionTimingFuncToEasing;