Magic_Game/Kiwano/math/ease.hpp

287 lines
5.9 KiB
C++

// Copyright (c) 2016-2018 Kiwano - 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 kiwano
{
namespace math
{
inline float Linear(float step)
{
return step;
}
// Ease
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);
}
// Exponential Ease
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)));
}
// Bounce Ease
inline float EaseBounceOut(float step)
{
if (step < 1 / 2.75f)
{
return 7.5625f * step * step;
}
else if (step < 2 / 2.75f)
{
step -= 1.5f / 2.75f;
return 7.5625f * step * step + 0.75f;
}
else if (step < 2.5f / 2.75f)
{
step -= 2.25f / 2.75f;
return 7.5625f * step * step + 0.9375f;
}
step -= 2.625f / 2.75f;
return 7.5625f * step * step + 0.984375f;
}
inline float EaseBounceIn(float step)
{
return 1 - EaseBounceOut(1 - step);
}
inline float EaseBounceInOut(float step)
{
if (step < 0.5f)
{
return EaseBounceIn(step * 2) * 0.5f;
}
else
{
return EaseBounceOut(step * 2 - 1) * 0.5f + 0.5f;
}
}
// Elastic Ease
inline float EaseElasticIn(float step, float period)
{
if (step == 0 || step == 1)
return step;
step = step - 1;
return -math::Pow(2, 10 * step) * math::Sin((step - period / 4) * 360.f / period);
}
inline float EaseElasticOut(float step, float period)
{
if (step == 0 || step == 1)
return step;
return math::Pow(2, -10 * step) * math::Sin((step - period / 4) * 360.f / period) + 1;
}
inline float EaseElasticInOut(float step, float period)
{
if (step == 0 || step == 1)
return step;
step = step * 2 - 1;
if (step < 0)
{
return -0.5f * math::Pow(2, 10 * step) * math::Sin((step - period / 4) * 360.f / period);
}
return math::Pow(2, -10 * step) * math::Sin((step - period / 4) * 360.f / period) * 0.5f + 1;
}
// Back Ease
inline float EaseBackIn(float step)
{
const float overshoot = 1.70158f;
return step * step * ((overshoot + 1) * step - overshoot);
}
inline float EaseBackOut(float step)
{
const float overshoot = 1.70158f;
step = step - 1;
return step * step * ((overshoot + 1) * step + overshoot) + 1;
}
inline float EaseBackInOut(float step)
{
const float overshoot = 1.70158f * 1.525f;
step = step * 2;
if (step < 1)
{
return (step * step * ((overshoot + 1) * step - overshoot)) / 2;
}
step = step - 2;
return (step * step * ((overshoot + 1) * step + overshoot)) / 2 + 1;
}
// Sine Ease
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);
}
// Quad Ease
inline float EaseQuadIn(float step)
{
return step * step;
}
inline float EaseQuadOut(float step)
{
return -1 * step * (step - 2);
}
inline float EaseQuadInOut(float step)
{
step = step * 2;
if (step < 1)
return 0.5f * step * step;
--step;
return -0.5f * (step * (step - 2) - 1);
}
// Cubic Ease
inline float EaseCubicIn(float step)
{
return step * step * step;
}
inline float EaseCubicOut(float step)
{
step -= 1;
return (step * step * step + 1);
}
inline float EaseCubicInOut(float step)
{
step = step * 2;
if (step < 1)
return 0.5f * step * step * step;
step -= 2;
return 0.5f * (step * step * step + 2);
}
// Quart Ease
inline float EaseQuartIn(float step)
{
return step * step * step * step;
}
inline float EaseQuartOut(float step)
{
step -= 1;
return -(step * step * step * step - 1);
}
inline float EaseQuartInOut(float step)
{
step = step * 2;
if (step < 1)
return 0.5f * step * step * step * step;
step -= 2;
return -0.5f * (step * step * step * step - 2);
}
// Quint Ease
inline float EaseQuintIn(float step)
{
return step * step * step * step * step;
}
inline float EaseQuintOut(float step)
{
step -= 1;
return (step * step * step * step * step + 1);
}
inline float EaseQuintInOut(float step)
{
step = step * 2;
if (step < 1)
return 0.5f * step * step * step * step * step;
step -= 2;
return 0.5f * (step * step * step * step * step + 2);
}
}
}