////  Interpolate.h//  libraries/shared/src////  Created by David Rowe on 10 Sep 2015.//  Copyright 2015 High Fidelity, Inc.////  Distributed under the Apache License, Version 2.0.//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html// #ifndef hifi_Interpolate_h#define hifi_Interpolate_h #include "SharedUtil.h" class Interpolate { public:    // Bezier interpolate at position u [0.0 - 1.0] between y values equally spaced along the x-axis. The interpolated values    // pass through y1 and y3 but not y2; y2 is the Bezier control point.    static float bezierInterpolate(float y1, float y2, float y3, float u);     // Interpolate at position u [0.0 - 1.0] between y values equally spaced along the x-axis such that the interpolated values    // pass through all three y values. Return value lies wholly within the range of y values passed in.    static float interpolate3Points(float y1, float y2, float y3, float u);     // returns smooth in and out blend between 0 and 1    // DANGER: assumes fraction is properly inside range [0, 1]    static float simpleNonLinearBlend(float fraction);     static float calculateFadeRatio(quint64 start);     // Basic ease-in-ease-out function for smoothing values.    static float easeInOutQuad(float lerpValue);}; #endif // hifi_Interpolate_h