Vector.java

/*
 * Copyright (c) 2002-2008 LWJGL Project
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
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 *
 * * Redistributions of source code must retain the above copyright
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 *
 * * Redistributions in binary form must reproduce the above copyright
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 *   documentation and/or other materials provided with the distribution.
 *
 * * Neither the name of 'LWJGL' 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
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 */
package org.lwjgl.util.vector;

import java.io.Serializable;
import java.nio.FloatBuffer;

/**
 *
 * Base class for vectors.
 *
 * @author cix_foo <cix_foo@users.sourceforge.net>
 * @version $Revision$
 * $Id$
 */
public abstract class Vector implements Serializable, ReadableVector {

	/**
	 * Constructor for Vector.
	 */
	protected Vector() {
		super();
	}

	/**
	 * @return the length of the vector
	 */
	public final float length() {
		return (float) Math.sqrt(lengthSquared());
	}


	/**
	 * @return the length squared of the vector
	 */
	public abstract float lengthSquared();

	/**
	 * Load this vector from a FloatBuffer
	 * @param buf The buffer to load it from, at the current position
	 * @return this
	 */
	public abstract Vector load(FloatBuffer buf);

	/**
	 * Negate a vector
	 * @return this
	 */
	public abstract Vector negate();


	/**
	 * Normalise this vector
	 * @return this
	 */
	public final Vector normalise() {
		float len = length();
		if (len != 0.0f) {
			float l = 1.0f / len;
			return scale(l);
		} else
			throw new IllegalStateException("Zero length vector");
	}


	/**
	 * Store this vector in a FloatBuffer
	 * @param buf The buffer to store it in, at the current position
	 * @return this
	 */
	public abstract Vector store(FloatBuffer buf);


	/**
	 * Scale this vector
	 * @param scale The scale factor
	 * @return this
	 */
	public abstract Vector scale(float scale);



}