Magic_Game/core/math/ease.hpp

83 lines
2.2 KiB
C++

// Copyright (c) 2016-2018 Easy2D - Nomango
//
// 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.
#pragma once
#include "scalar.hpp"
namespace easy2d
{
namespace math
{
inline float Linear(float step)
{
return step;
}
inline float EaseIn(float step, float rate)
{
return math::Pow(step, rate);
}
inline float EaseOut(float step, float rate)
{
return math::Pow(step, 1.f / rate);
}
inline float EaseInOut(float step, float rate)
{
if (step < .5f)
return .5f * math::Pow(2 * step, rate);
return 1.f - .5f * math::Pow(2.f - 2 * step, rate);
}
inline float EaseExponentialIn(float step)
{
return math::Pow(2.f, 10 * (step - 1));
}
inline float EaseExponentialOut(float step)
{
return 1.f - math::Pow(2.f, -10 * step);
}
inline float EaseExponentialInOut(float step)
{
if (step < .5f)
return .5f * math::Pow(2.f, 10 * (2 * step - 1));
return 0.5f * (2 - math::Pow(2, -10 * (step * 2 - 1)));
}
inline float EaseSineIn(float step)
{
return 1.f - math::Cos(step * 90);
}
inline float EaseSineOut(float step)
{
return math::Sin(step * 90);
}
inline float EaseSineInOut(float step)
{
return -0.5f * (math::Cos(step * 180) - 1);
}
}
}