/*
* Copyright (c) 2003-onwards Shaven Puppy Ltd
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* * Neither the name of 'Shaven Puppy' nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package com.shavenpuppy.jglib.interpolators;
import java.io.ObjectInput;
import java.io.ObjectStreamException;
/**
* A cosine interpolator. Access using instance member variable.
* Creation date: (30/03/2001 01:19:35)
* @author: cas
*/
public final class CosineInterpolator extends InterpolatorBase {
private static final long serialVersionUID = 1L;
public static final CosineInterpolator instance = new CosineInterpolator();
/**
* CosineInterpolator can only be accessed as a singleton.
*/
private CosineInterpolator() {
super();
}
/**
* Cosine interpolation.
*/
@Override
public float interpolate(float a, float b, float ratio) {
if (a == b) {
return a;
}
if (ratio < 0.0f) {
ratio = 0.0f;
} else if (ratio > 1.0f) {
ratio = 1.0f;
}
// double ft = ratio * Math.PI / 2.0;
// double f = 1.0 - Math.cos(ft);
double f = Math.sqrt(1.0 - ratio * ratio);
return (float) (a * f + b * (1.0 - f));
}
private Object readResolve(ObjectInput oi) throws ObjectStreamException {
return instance;
}
}