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Diffstat (limited to 'Xamarin.Forms.Core/Easing.cs')
-rw-r--r-- | Xamarin.Forms.Core/Easing.cs | 98 |
1 files changed, 98 insertions, 0 deletions
diff --git a/Xamarin.Forms.Core/Easing.cs b/Xamarin.Forms.Core/Easing.cs new file mode 100644 index 00000000..8d64e255 --- /dev/null +++ b/Xamarin.Forms.Core/Easing.cs @@ -0,0 +1,98 @@ +// +// Tweener.cs +// +// Author: +// Jason Smith <jason.smith@xamarin.com> +// +// 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<double, double> _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<double, double> easingFunc) + { + if (easingFunc == null) + throw new ArgumentNullException("easingFunc"); + + _easingFunc = easingFunc; + } + + public double Ease(double v) + { + return _easingFunc(v); + } + + public static implicit operator Easing(Func<double, double> func) + { + return new Easing(func); + } + } +}
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