axmol/extensions/libeditor/CCActionFrameEasing.cpp

/****************************************************************************
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#include <math.h>
#include "libeditor/CCActionFrameEasing.h"
#include "libeditor/DictionaryHelper.h"
#include "platform/CCStdC.h"

namespace cocostudio {

#ifndef M_PI_X_2
#define M_PI_X_2 (float)M_PI * 2.0f
#endif

ActionFrameEasing::ActionFrameEasing()
{

}
ActionFrameEasing::~ActionFrameEasing()
{

}

float ActionFrameEasing::bounceTime(float t)
{
	if (t < 1 / 2.75) {
		return 7.5625f * t * t;
	}
	else if (t < 2 / 2.75) {
		t -= 1.5f / 2.75f;
		return 7.5625f * t * t + 0.75f;
	}
	else if (t < 2.5 / 2.75) {
		t -= 2.25f / 2.75f;
		return 7.5625f * t * t + 0.9375f;
	}

	t -= 2.625f / 2.75f;
	return 7.5625f * t * t + 0.984375f;
}

float ActionFrameEasing::easeValue(float t)
{
	if (_type == FrameEasingType::kframeEasingInstant)
	{
		if (t < 1) return 0;
		else return 1;
	}
	else if (_type == FrameEasingType::kframeEasingLinear)
	{
		return t;
	}
	else if (_type == FrameEasingType::kframeEasingCubicIn)
	{
		float rate = _fValue;
		return powf(t,rate);
	}
	else if (_type == FrameEasingType::kframeEasingCubicOut)
	{
		float rate = _fValue;
		return powf(t,1/rate);
	}
	else if (_type == FrameEasingType::kframeEasingCubicInOut)
	{
		float rate = _fValue;
		t *= 2;
		if (t < 1)
		{
			return 0.5f * powf (t, rate);
		}
		else
		{
			return 1.0f - 0.5f * powf(2-t, rate);
		}
	}
	else if (_type == FrameEasingType::kframeEasingElasticIn)
	{
		float period = _fValue;
		float newT = 0;
		if (t == 0 || t == 1)
			newT = t;

		else {
			float s = period / 4;
			t = t - 1;
			newT = -powf(2, 10 * t) * sinf( (t-s) * M_PI_X_2 / period);
		}
		return newT;
	}
	else if (_type == FrameEasingType::kframeEasingElasticOut)
	{
		float period = _fValue;
		float newT = 0;
		if (t == 0 || t == 1) {
			newT = t;

		} else {
			float s = period / 4;
			newT = powf(2, -10 * t) * sinf( (t-s) *M_PI_X_2 / period) + 1;
		}
		return newT;
	}
	else if (_type == FrameEasingType::kframeEasingElasticInOut)
	{
		float period = _fValue;
		float newT = 0;
		if( t == 0 || t == 1 )
			newT = t;
		else {
			t = t * 2;
			if(! period )
				period = 0.3f * 1.5f;
			float s = period / 4;

			t = t -1;
			if( t < 0 )
				newT = -0.5f * powf(2, 10 * t) * sinf((t - s) * M_PI_X_2 / period);
			else
				newT = powf(2, -10 * t) * sinf((t - s) * M_PI_X_2 / period) * 0.5f + 1;
		}
		return newT;
	}
	else if (_type == FrameEasingType::kframeEasingBounceIn)
	{
		float newT = 1 - bounceTime(1-t);
		return newT;
	}
	else if (_type == FrameEasingType::kframeEasingBounceOut)
	{
		float newT = bounceTime(t);
		return newT;
	}
	else if (_type == FrameEasingType::kframeEasingBounceInOut)
	{
		float newT = 0;
		if (t < 0.5) {
			t = t * 2;
			newT = (1 - bounceTime(1-t) ) * 0.5f;
		} else
			newT = bounceTime(t * 2 - 1) * 0.5f + 0.5f;
		return newT;
	}
	else if (_type == FrameEasingType::kframeEasingBackIn)
	{
		float overshoot = 1.70158f;
		return t * t * ((overshoot + 1) * t - overshoot);
	}
	else if (_type == FrameEasingType::kframeEasingBackOut)
	{
		float overshoot = 1.70158f;
		t = t - 1;
		return t * t * ((overshoot + 1) * t + overshoot) + 1;
	}
	else if (_type == FrameEasingType::kframeEasingBackInOut)
	{
		float overshoot = 1.70158f * 1.525f;

		t = t * 2;
		if (t < 1)
			return (t * t * ((overshoot + 1) * t - overshoot)) / 2;
		else {
			t = t - 2;
			return (t * t * ((overshoot + 1) * t + overshoot)) / 2 + 1;
		}
	}

	return 0;
}

}