// // Tweener.cs // // Author: // Jason Smith // // Copyright (c) 2012 Xamarin Inc. // // Permission is hereby granted, free of charge, to any person obtaining a copy // of this software and associated documentation files (the "Software"), to deal // in the Software without restriction, including without limitation the rights // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell // copies of the Software, and to permit persons to whom the Software is // furnished to do so, subject to the following conditions: // // The above copyright notice and this permission notice shall be included in // all copies or substantial portions of the Software. // // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN // THE SOFTWARE. using System; namespace Xamarin.Forms { public class Easing { public static readonly Easing Linear = new Easing(x => x); public static readonly Easing SinOut = new Easing(x => Math.Sin(x * Math.PI * 0.5f)); public static readonly Easing SinIn = new Easing(x => 1.0f - Math.Cos(x * Math.PI * 0.5f)); public static readonly Easing SinInOut = new Easing(x => -Math.Cos(Math.PI * x) / 2.0f + 0.5f); public static readonly Easing CubicIn = new Easing(x => x * x * x); public static readonly Easing CubicOut = new Easing(x => Math.Pow(x - 1.0f, 3.0f) + 1.0f); public static readonly Easing CubicInOut = new Easing(x => x < 0.5f ? Math.Pow(x * 2.0f, 3.0f) / 2.0f : (Math.Pow((x - 1) * 2.0f, 3.0f) + 2.0f) / 2.0f); public static readonly Easing BounceOut; public static readonly Easing BounceIn; public static readonly Easing SpringIn = new Easing(x => x * x * ((1.70158f + 1) * x - 1.70158f)); public static readonly Easing SpringOut = new Easing(x => (x - 1) * (x - 1) * ((1.70158f + 1) * (x - 1) + 1.70158f) + 1); readonly Func _easingFunc; static Easing() { BounceOut = new Easing(p => { if (p < 1 / 2.75f) { return 7.5625f * p * p; } if (p < 2 / 2.75f) { p -= 1.5f / 2.75f; return 7.5625f * p * p + .75f; } if (p < 2.5f / 2.75f) { p -= 2.25f / 2.75f; return 7.5625f * p * p + .9375f; } p -= 2.625f / 2.75f; return 7.5625f * p * p + .984375f; }); BounceIn = new Easing(p => 1.0f - BounceOut.Ease(1 - p)); } public Easing(Func easingFunc) { if (easingFunc == null) throw new ArgumentNullException("easingFunc"); _easingFunc = easingFunc; } public double Ease(double v) { return _easingFunc(v); } public static implicit operator Easing(Func func) { return new Easing(func); } } }