Robert Penner 的缓动方程

在 Qt 核心库中使用（QEasingCurve）。

源代码可在 qtbase/src/3rdparty/easing/easing.cpp 中找到。

Copyright (c) 2001 Robert Penner

BSD 3 条款 "新" 或 "修订" 许可协议.

Copyright (c) 2001 Robert Penner
All rights reserved.

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