tongyu_visu/public/supermap/libs/bezier-easing/2.1.0/bezier-easing.js

/**
 * https://github.com/gre/bezier-easing
 * BezierEasing - use bezier curve for transition easing function
 * by Gaëtan Renaudeau 2014 - 2015 – MIT License
 *
 * https://github.com/manubb/Leaflet.PixiOverlay
 */
(function(f) {
    if (typeof exports === 'object' && typeof module !== 'undefined') {
        module.exports = f();
    } else if (typeof define === 'function' && define.amd) {
        define([], f);
    } else {
        var g;
        if (typeof window !== 'undefined') {
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        } else if (typeof global !== 'undefined') {
            g = global;
        } else if (typeof self !== 'undefined') {
            g = self;
        } else {
            g = this;
        }
        g.BezierEasing = f();
    }
})(function() {
    var define, module, exports;
    return (function() {
        function r(e, n, t) {
            function o(i, f) {
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        return r;
    })()(
        {
            1: [
                function(require, module, exports) {
                    /**
                     * https://github.com/gre/bezier-easing
                     * BezierEasing - use bezier curve for transition easing function
                     * by Gaëtan Renaudeau 2014 - 2015 – MIT License
                     */

                        // These values are established by empiricism with tests (tradeoff: performance VS precision)
                    var NEWTON_ITERATIONS = 4;
                    var NEWTON_MIN_SLOPE = 0.001;
                    var SUBDIVISION_PRECISION = 0.0000001;
                    var SUBDIVISION_MAX_ITERATIONS = 10;

                    var kSplineTableSize = 11;
                    var kSampleStepSize = 1.0 / (kSplineTableSize - 1.0);

                    var float32ArraySupported = typeof Float32Array === 'function';

                    function A(aA1, aA2) {
                        return 1.0 - 3.0 * aA2 + 3.0 * aA1;
                    }
                    function B(aA1, aA2) {
                        return 3.0 * aA2 - 6.0 * aA1;
                    }
                    function C(aA1) {
                        return 3.0 * aA1;
                    }

                    // Returns x(t) given t, x1, and x2, or y(t) given t, y1, and y2.
                    function calcBezier(aT, aA1, aA2) {
                        return ((A(aA1, aA2) * aT + B(aA1, aA2)) * aT + C(aA1)) * aT;
                    }

                    // Returns dx/dt given t, x1, and x2, or dy/dt given t, y1, and y2.
                    function getSlope(aT, aA1, aA2) {
                        return 3.0 * A(aA1, aA2) * aT * aT + 2.0 * B(aA1, aA2) * aT + C(aA1);
                    }

                    function binarySubdivide(aX, aA, aB, mX1, mX2) {
                        var currentX,
                            currentT,
                            i = 0;
                        do {
                            currentT = aA + (aB - aA) / 2.0;
                            currentX = calcBezier(currentT, mX1, mX2) - aX;
                            if (currentX > 0.0) {
                                aB = currentT;
                            } else {
                                aA = currentT;
                            }
                        } while (Math.abs(currentX) > SUBDIVISION_PRECISION && ++i < SUBDIVISION_MAX_ITERATIONS);
                        return currentT;
                    }

                    function newtonRaphsonIterate(aX, aGuessT, mX1, mX2) {
                        for (var i = 0; i < NEWTON_ITERATIONS; ++i) {
                            var currentSlope = getSlope(aGuessT, mX1, mX2);
                            if (currentSlope === 0.0) {
                                return aGuessT;
                            }
                            var currentX = calcBezier(aGuessT, mX1, mX2) - aX;
                            aGuessT -= currentX / currentSlope;
                        }
                        return aGuessT;
                    }

                    function LinearEasing(x) {
                        return x;
                    }

                    module.exports = function bezier(mX1, mY1, mX2, mY2) {
                        if (!(0 <= mX1 && mX1 <= 1 && 0 <= mX2 && mX2 <= 1)) {
                            throw new Error('bezier x values must be in [0, 1] range');
                        }

                        if (mX1 === mY1 && mX2 === mY2) {
                            return LinearEasing;
                        }

                        // Precompute samples table
                        var sampleValues = float32ArraySupported ? new Float32Array(kSplineTableSize) : new Array(kSplineTableSize);
                        for (var i = 0; i < kSplineTableSize; ++i) {
                            sampleValues[i] = calcBezier(i * kSampleStepSize, mX1, mX2);
                        }

                        function getTForX(aX) {
                            var intervalStart = 0.0;
                            var currentSample = 1;
                            var lastSample = kSplineTableSize - 1;

                            for (; currentSample !== lastSample && sampleValues[currentSample] <= aX; ++currentSample) {
                                intervalStart += kSampleStepSize;
                            }
                            --currentSample;

                            // Interpolate to provide an initial guess for t
                            var dist =
                                (aX - sampleValues[currentSample]) / (sampleValues[currentSample + 1] - sampleValues[currentSample]);
                            var guessForT = intervalStart + dist * kSampleStepSize;

                            var initialSlope = getSlope(guessForT, mX1, mX2);
                            if (initialSlope >= NEWTON_MIN_SLOPE) {
                                return newtonRaphsonIterate(aX, guessForT, mX1, mX2);
                            } else if (initialSlope === 0.0) {
                                return guessForT;
                            } else {
                                return binarySubdivide(aX, intervalStart, intervalStart + kSampleStepSize, mX1, mX2);
                            }
                        }

                        return function BezierEasing(x) {
                            // Because JavaScript number are imprecise, we should guarantee the extremes are right.
                            if (x === 0) {
                                return 0;
                            }
                            if (x === 1) {
                                return 1;
                            }
                            return calcBezier(getTForX(x), mY1, mY2);
                        };
                    };
                },
                {}
            ]
        },
        {},
        [1]
    )(1);
});