/*
 * $RCSfile$
 *
 * Copyright (c) 2006 Sun Microsystems, Inc. All rights reserved.
 *
 * Use is subject to license terms.
 *
 * $Revision$
 * $Date$
 * $State$
 */

package javax.vecmath;

import java.lang.Math;

/**
 * A 3-element vector that is represented by single-precision floating point 
 * x,y,z coordinates.  If this value represents a normal, then it should
 * be normalized.
 *
 */
public class Vector3f extends Tuple3f implements java.io.Serializable {

    // Combatible with 1.1
    static final long serialVersionUID = -7031930069184524614L;

    /**
     * Constructs and initializes a Vector3f from the specified xyz coordinates.
     * @param x the x coordinate
     * @param y the y coordinate
     * @param z the z coordinate
     */
    public Vector3f(float x, float y, float z)
    {
        super(x,y,z);
    }


    /**
     * Constructs and initializes a Vector3f from the array of length 3.
     * @param v the array of length 3 containing xyz in order
     */
    public Vector3f(float[] v)
    {
       super(v);
    }


    /**
     * Constructs and initializes a Vector3f from the specified Vector3f.
     * @param v1 the Vector3f containing the initialization x y z data
     */
    public Vector3f(Vector3f v1)
    {
       super(v1);
    }


    /**
     * Constructs and initializes a Vector3f from the specified Vector3d.
     * @param v1 the Vector3d containing the initialization x y z data
     */
    public Vector3f(Vector3d v1)
    {
       super(v1);
    }


    /**
     * Constructs and initializes a Vector3f from the specified Tuple3f.
     * @param t1 the Tuple3f containing the initialization x y z data
     */  
    public Vector3f(Tuple3f t1) {
       super(t1);
    }


    /**
     * Constructs and initializes a Vector3f from the specified Tuple3d.
     * @param t1 the Tuple3d containing the initialization x y z data
     */  
    public Vector3f(Tuple3d t1) {
       super(t1);
    }


    /**
     * Constructs and initializes a Vector3f to (0,0,0).
     */
    public Vector3f()
    {
        super();
    }


   /**
     * Returns the squared length of this vector.
     * @return the squared length of this vector
     */
    public final float lengthSquared()
    {
        return (this.x*this.x + this.y*this.y + this.z*this.z);
    }

    /**
     * Returns the length of this vector.
     * @return the length of this vector
     */
    public final float length()
    {
        return (float)
             Math.sqrt(this.x*this.x + this.y*this.y + this.z*this.z);
    }


  /**
     * Sets this vector to be the vector cross product of vectors v1 and v2.
     * @param v1 the first vector
     * @param v2 the second vector
     */
    public final void cross(Vector3f v1, Vector3f v2)
    {
        float x,y;

        x = v1.y*v2.z - v1.z*v2.y;
        y = v2.x*v1.z - v2.z*v1.x;
        this.z = v1.x*v2.y - v1.y*v2.x;
        this.x = x;
        this.y = y;
    }

 /**
   * Computes the dot product of this vector and vector v1.
   * @param v1 the other vector
   * @return the dot product of this vector and v1
   */
  public final float dot(Vector3f v1)
    {
      return (this.x*v1.x + this.y*v1.y + this.z*v1.z);
    }

   /**
     * Sets the value of this vector to the normalization of vector v1.
     * @param v1 the un-normalized vector
     */
    public final void normalize(Vector3f v1)
    {
        float norm;

        norm = (float) (1.0/Math.sqrt(v1.x*v1.x + v1.y*v1.y + v1.z*v1.z));
        this.x = v1.x*norm;
        this.y = v1.y*norm;
        this.z = v1.z*norm;
    }

    /**
     * Normalizes this vector in place.
     */
    public final void normalize()
    {
        float norm;

        norm = (float)
               (1.0/Math.sqrt(this.x*this.x + this.y*this.y + this.z*this.z));
        this.x *= norm;
        this.y *= norm;
        this.z *= norm;
    }


  /** 
    *   Returns the angle in radians between this vector and the vector
    *   parameter; the return value is constrained to the range [0,PI]. 
    *   @param v1    the other vector 
    *   @return   the angle in radians in the range [0,PI] 
    */   
   public final float angle(Vector3f v1) 
   { 
      double vDot = this.dot(v1) / ( this.length()*v1.length() );
      if( vDot < -1.0) vDot = -1.0;
      if( vDot >  1.0) vDot =  1.0;
      return((float) (Math.acos( vDot )));
   } 

}