/*
 * $RCSfile$
 *
 * 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 four-element axis angle represented by single-precision floating point 
 * x,y,z,angle components.  An axis angle is a rotation of angle (radians)
 * about the vector (x,y,z).
 *
 */
public class AxisAngle4f implements java.io.Serializable, Cloneable {

  // Compatible with 1.1
  static final long serialVersionUID = -163246355858070601L;

  /**
   * The x coordinate.
   */
  public	float	x;

  /**
   * The y coordinate.
   */
  public	float	y;

  /**
   * The z coordinate.
   */
  public	float	z;

  /**
   * The angle of rotation in radians.
   */
  public	float	angle;

  final static double EPS = 0.000001;

  /**
   * Constructs and initializes a AxisAngle4f from the specified xyzw coordinates.
   * @param x the x coordinate
   * @param y the y coordinate
   * @param z the z coordinate
   * @param angle  the angle of rotation in radians
   */
  public AxisAngle4f(float x, float y, float z, float angle)
  {
    this.x = x;
    this.y = y;
    this.z = z;
    this.angle = angle;
  }


  /**
   * Constructs and initializes an AxisAngle4f from the array of length 4. 
   * @param a the array of length 4 containing x,y,z,angle in order
   */
  public AxisAngle4f(float[] a)
  {
    this.x = a[0];
    this.y = a[1];
    this.z = a[2];
    this.angle = a[3];
  }


  /**
   * Constructs and initializes an AxisAngle4f from the specified 
   * AxisAngle4f.
   * @param a1 the AxisAngle4f containing the initialization x y z angle data
   */
  public AxisAngle4f(AxisAngle4f a1)
  {
    this.x = a1.x;
    this.y = a1.y;
    this.z = a1.z;
    this.angle = a1.angle;
  }


  /**
   * Constructs and initializes an AxisAngle4f from the specified AxisAngle4d.
   * @param a1 the AxisAngle4d containing the initialization x y z angle data
   */
  public AxisAngle4f(AxisAngle4d a1)
  {
    this.x = (float) a1.x;
    this.y = (float) a1.y;
    this.z = (float) a1.z;
    this.angle = (float) a1.angle;
  }


    /**
     * Constructs and initializes an AxisAngle4f from the specified 
     * axis and angle.
     * @param axis the axis
     * @param angle the angle of rotation in radians
     *
     * @since vecmath 1.2
     */
    public AxisAngle4f(Vector3f axis, float angle) {
	this.x = axis.x;
	this.y = axis.y;
	this.z = axis.z;
	this.angle = angle;
    }


  /**
   * Constructs and initializes an AxisAngle4f to (0,0,1,0).
   */
  public AxisAngle4f()
  {
    this.x = 0.0f;
    this.y = 0.0f;
    this.z = 1.0f;
    this.angle = 0.0f;
  }


    /**
     * Sets the value of this axis-angle to the specified x,y,z,angle. 
     * @param x the x coordinate
     * @param y the y coordinate
     * @param z the z coordinate
     * @param angle  the angle of rotation in radians
     */
    public final void set(float x, float y, float z, float angle)
    {
	this.x = x;
	this.y = y;
	this.z = z;
	this.angle = angle;
    }


    /**
     * Sets the value of this axis-angle to the specified values in the
     * array of length 4.
     * @param a the array of length 4 containing x,y,z,angle in order
     */
    public final void set(float[] a)
    {
	this.x = a[0];
	this.y = a[1];
	this.z = a[2];
	this.angle = a[3];
    }


    /**
     * Sets the value of this axis-angle to the value of axis-angle a1.
     * @param a1 the axis-angle to be copied
     */
    public final void set(AxisAngle4f a1)
    {
	this.x = a1.x;
	this.y = a1.y;
	this.z = a1.z;
	this.angle = a1.angle;
    }


    /**
     * Sets the value of this axis-angle to the value of axis-angle a1.
     * @param a1 the axis-angle to be copied
     */
    public final void set(AxisAngle4d a1)
    {
	this.x = (float) a1.x;
	this.y = (float) a1.y;
	this.z = (float) a1.z;
	this.angle = (float) a1.angle;
    }


    /**
     * Sets the value of this AxisAngle4f to the specified 
     * axis and angle.
     * @param axis the axis
     * @param angle the angle of rotation in radians
     *
     * @since vecmath 1.2
     */
    public final void set(Vector3f axis, float angle) {
	this.x = axis.x;
	this.y = axis.y;
	this.z = axis.z;
	this.angle = angle;
    }


    /**
     * Copies the value of this axis-angle into the array a.
     * @param a the array 
     */
   public final void get(float[] a)
   {
      a[0] = this.x;
      a[1] = this.y;
      a[2] = this.z;
      a[3] = this.angle;
   } 


    /**
      * Sets the value of this axis-angle to the rotational equivalent
      * of the passed quaternion.
      * If the specified quaternion has no rotational component, the value
      * of this AxisAngle4f is set to an angle of 0 about an axis of (0,1,0).
      * @param q1  the Quat4f
      */
    public final void set(Quat4f q1)
    {
	double mag = q1.x*q1.x + q1.y*q1.y + q1.z*q1.z;  

	if ( mag > EPS ) {
	    mag = Math.sqrt(mag);
	    double invMag = 1.0/mag;
	    
	    x = (float)(q1.x*invMag);
	    y = (float)(q1.y*invMag);
	    z = (float)(q1.z*invMag);
	    angle = (float)(2.0*Math.atan2(mag, q1.w)); 
        } else {
	    x = 0.0f;
	    y = 1.0f;
	    z = 0.0f;
	    angle = 0.0f;
	}
    }


    /**
      * Sets the value of this axis-angle to the rotational equivalent
      * of the passed quaternion.
      * If the specified quaternion has no rotational component, the value
      * of this AxisAngle4f is set to an angle of 0 about an axis of (0,1,0).
      * @param q1  the Quat4d
      */
    public final void set(Quat4d q1)
    {
        double mag = q1.x*q1.x + q1.y*q1.y + q1.z*q1.z;  

        if (mag > EPS) {
	    mag = Math.sqrt(mag);
	    double invMag = 1.0/mag;

	    x = (float)(q1.x*invMag);
	    y = (float)(q1.y*invMag);
	    z = (float)(q1.z*invMag);
	    angle = (float)(2.0*Math.atan2(mag, q1.w)); 
        } else {
	    x = 0.0f;
	    y = 1.0f;
	    z = 0.0f;
	    angle = 0.0f;
	}
    }


  /**
   * Sets the value of this axis-angle to the rotational component of
   * the passed matrix.
   * If the specified matrix has no rotational component, the value
   * of this AxisAngle4f is set to an angle of 0 about an axis of (0,1,0).
   * @param m1 the matrix4f
   */
  public final void set(Matrix4f m1)
  {
        Matrix3f m3f = new Matrix3f();

        m1.get(m3f);

        x = m3f.m21 - m3f.m12;
        y = m3f.m02 - m3f.m20;
        z = m3f.m10 - m3f.m01;
        double mag = x*x + y*y + z*z;

	if (mag > EPS) {
	    mag = Math.sqrt(mag);
	    double sin = 0.5*mag;
	    double cos = 0.5*(m3f.m00 + m3f.m11 + m3f.m22 - 1.0);

	    angle = (float)Math.atan2(sin, cos);
	    double invMag = 1.0/mag;
	    x = (float)(x*invMag);
	    y = (float)(y*invMag);
	    z = (float)(z*invMag);
	} else {
	    x = 0.0f;
	    y = 1.0f;
	    z = 0.0f;
	    angle = 0.0f;
	}


  }


  /**
   * Sets the value of this axis-angle to the rotational component of
   * the passed matrix.
   * If the specified matrix has no rotational component, the value
   * of this AxisAngle4f is set to an angle of 0 about an axis of (0,1,0).
   * @param m1 the matrix4d
   */
  public final void set(Matrix4d m1)
  {
        Matrix3d m3d = new Matrix3d();

        m1.get(m3d);


        x = (float)(m3d.m21 - m3d.m12);
        y = (float)(m3d.m02 - m3d.m20);
        z = (float)(m3d.m10 - m3d.m01);
        double mag = x*x + y*y + z*z;

	if (mag > EPS) {
	    mag = Math.sqrt(mag);
	    double sin = 0.5*mag;
	    double cos = 0.5*(m3d.m00 + m3d.m11 + m3d.m22 - 1.0);
	    angle = (float)Math.atan2(sin, cos);
	    
	    double invMag = 1.0/mag;
	    x = (float)(x*invMag);
	    y = (float)(y*invMag);
	    z = (float)(z*invMag);
	} else {
	    x = 0.0f;
	    y = 1.0f;
	    z = 0.0f;
	    angle = 0.0f;	    
	}

  }


  /**
   * Sets the value of this axis-angle to the rotational component of
   * the passed matrix.
   * If the specified matrix has no rotational component, the value
   * of this AxisAngle4f is set to an angle of 0 about an axis of (0,1,0).
   * @param m1 the matrix3f
   */
  public final void set(Matrix3f m1)
  {
        x = (float)(m1.m21 - m1.m12);
        y = (float)(m1.m02 - m1.m20);
        z = (float)(m1.m10 - m1.m01);
        double mag = x*x + y*y + z*z;
	if (mag > EPS) {
	    mag = Math.sqrt(mag);
	    double sin = 0.5*mag;
	    double cos = 0.5*(m1.m00 + m1.m11 + m1.m22 - 1.0);
	    
	    angle = (float)Math.atan2(sin, cos);
	    
	    double invMag = 1.0/mag;
	    x = (float)(x*invMag);
	    y = (float)(y*invMag);
	    z = (float)(z*invMag);
	} else {
	    x = 0.0f;
	    y = 1.0f;
	    z = 0.0f;
	    angle = 0.0f;	    
	}

  }


  /**
   * Sets the value of this axis-angle to the rotational component of
   * the passed matrix.
   * If the specified matrix has no rotational component, the value
   * of this AxisAngle4f is set to an angle of 0 about an axis of (0,1,0).
   * @param m1 the matrix3d
   */
  public final void set(Matrix3d m1)
  {

        x = (float)(m1.m21 - m1.m12);
        y = (float)(m1.m02 - m1.m20);
        z = (float)(m1.m10 - m1.m01);
        double mag = x*x + y*y + z*z;

	if (mag > EPS) {
	    mag = Math.sqrt(mag);
	    double sin = 0.5*mag;
	    double cos = 0.5*(m1.m00 + m1.m11 + m1.m22 - 1.0);
	    
	    angle = (float)Math.atan2(sin, cos);
	    
	    double invMag = 1.0/mag;
	    x = (float)(x*invMag);
	    y = (float)(y*invMag);
	    z = (float)(z*invMag);
	} else {
	    x = 0.0f;
	    y = 1.0f;
	    z = 0.0f;
	    angle = 0.0f;	    
	}
  }


   /**
     * Returns a string that contains the values of this AxisAngle4f.
     * The form is (x,y,z,angle).
     * @return the String representation
     */  
    public String toString() {
	return "(" + this.x + ", " + this.y + ", " + this.z + ", " + this.angle + ")";
    }


   /**
     * Returns true if all of the data members of AxisAngle4f a1 are
     * equal to the corresponding data members in this AxisAngle4f.
     * @param a1  the axis-angle with which the comparison is made
     * @return  true or false
     */  
    public boolean equals(AxisAngle4f a1)
    {
        try {
            return(this.x == a1.x && this.y == a1.y && this.z == a1.z
            && this.angle == a1.angle);
        }
        catch (NullPointerException e2) {return false;}

    }

    /**
     * Returns true if the Object o1 is of type AxisAngle4f and all of the
     * data members of o1 are equal to the corresponding data members in
     * this AxisAngle4f.
     * @param o1  the object with which the comparison is made
     * @return  true or false
      */  
    public boolean equals(Object o1)
    {
        try {
           AxisAngle4f a2 = (AxisAngle4f) o1;
           return(this.x == a2.x && this.y == a2.y && this.z == a2.z
            && this.angle == a2.angle);
        }
        catch (NullPointerException e2) {return false;}
        catch (ClassCastException   e1) {return false;}

    }

   /**
     * Returns true if the L-infinite distance between this axis-angle
     * and axis-angle a1 is less than or equal to the epsilon parameter, 
     * otherwise returns false.  The L-infinite
     * distance is equal to 
     * MAX[abs(x1-x2), abs(y1-y2), abs(z1-z2), abs(angle1-angle2)].
     * @param a1  the axis-angle to be compared to this axis-angle 
     * @param epsilon  the threshold value  
     */
    public boolean epsilonEquals(AxisAngle4f a1, float epsilon)
    {
       float diff;

       diff = x - a1.x;
       if((diff<0?-diff:diff) > epsilon) return false;

       diff = y - a1.y;
       if((diff<0?-diff:diff) > epsilon) return false;

       diff = z - a1.z;
       if((diff<0?-diff:diff) > epsilon) return false;

       diff = angle - a1.angle;
       if((diff<0?-diff:diff) > epsilon) return false;

       return true;

    }


    /**
     * Returns a hash code value based on the data values in this
     * object.  Two different AxisAngle4f objects with identical data values
     * (i.e., AxisAngle4f.equals returns true) will return the same hash
     * code value.  Two objects with different data members may return the
     * same hash value, although this is not likely.
     * @return the integer hash code value
     */  
    public int hashCode() {
	long bits = 1L;
	bits = 31L * bits + (long)VecMathUtil.floatToIntBits(x);
	bits = 31L * bits + (long)VecMathUtil.floatToIntBits(y);
	bits = 31L * bits + (long)VecMathUtil.floatToIntBits(z);
	bits = 31L * bits + (long)VecMathUtil.floatToIntBits(angle);
	return (int) (bits ^ (bits >> 32));
    }

    /**
     * Creates a new object of the same class as this object.
     *
     * @return a clone of this instance.
     * @exception OutOfMemoryError if there is not enough memory.
     * @see java.lang.Cloneable
     * @since vecmath 1.3
     */
    public Object clone() {
	// Since there are no arrays we can just use Object.clone()
	try {
	    return super.clone();
	} catch (CloneNotSupportedException e) {
	    // this shouldn't happen, since we are Cloneable
	    throw new InternalError();
	}
    }

}