/******************************************************************************* | |
* Copyright (c) 2010 IBM Corporation and others. | |
* All rights reserved. This program and the accompanying materials | |
* are made available under the terms of the Eclipse Public License v1.0 | |
* which accompanies this distribution, and is available at | |
* http://www.eclipse.org/legal/epl-v10.html | |
* | |
* Contributors: | |
* IBM Corporation - initial API and implementation | |
*******************************************************************************/ | |
package org.eclipse.xwt.animation; | |
import org.eclipse.xwt.XWTException; | |
/** | |
* | |
* @author yyang | |
*/ | |
public class ElasticEase extends EasingFunctionBase { | |
private int oscillations = 3; | |
private double springiness = 3; | |
public int getOscillations() { | |
return oscillations; | |
} | |
public void setOscillations(int oscillations) { | |
this.oscillations = oscillations; | |
} | |
public double getSpringiness() { | |
return springiness; | |
} | |
public void setSpringiness(double springiness) { | |
this.springiness = springiness; | |
} | |
public double ease(double normalizedTime) { | |
switch (getEasingMode()) { | |
case EaseIn: | |
return easeValue(normalizedTime, getOscillations(), | |
getSpringiness()); | |
case EaseOut: | |
return 1 - easeValue(1 - normalizedTime, getOscillations(), | |
getSpringiness()); | |
case EaseInOut: | |
normalizedTime /= 0.5; | |
if (normalizedTime < 1) | |
return easeValue(normalizedTime, getOscillations(), | |
getSpringiness()) / 2; | |
return (2 - easeValue(2 - normalizedTime, getOscillations(), | |
getSpringiness())) / 2; | |
default: | |
throw new XWTException(getEasingMode().name() + " is supported."); | |
} | |
} | |
protected double easeValue(double current, int oscillations, | |
double springiness) { | |
if (current == 0) | |
return 0; | |
if (current == 1) | |
return 1; | |
double s = Math.asin(1) / ((2 * Math.PI) * oscillations); | |
return -(Math.pow(2, 10 * (current -= 1)) * Math.sin((current - s) | |
* (2 * Math.PI) * oscillations)); | |
} | |
} |